Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/13/13
AREA FORECAST DISCUSSION
NWS TUCSON AZ
850 PM MST FRI JUL 12 2013
.SYNOPSIS...WITH A BIT LESS ATMOSPHERIC MOISTURE OVER THE AREA EACH
DAY THROUGH SUNDAY THE SHOWER AND THUNDERSTORM ACTIVITY WILL
DIMINISH SOMEWHAT THROUGH THE WEEKEND WITH HIGH TEMPERATURES SLOWLY
RISING. THEN A WEATHER SYSTEM FROM THE PLAINS STATES WILL MOVE WEST
AND BEGIN TO AFFECT OUR WEATHER EARLY NEXT WEEK WITH MORE MOISTURE
AND INSTABILITY. THIS WILL INCREASE THE THREAT OF SHOWERS AND
THUNDERSTORMS MONDAY ONWARD WITH HIGH TEMPERATURES COOLING OFF A BIT
ONCE AGAIN.
&&
.DISCUSSION...MUCH OF THE CWA HAS SETTLED DOWN AFTER THE PRECIP OVER
THE PAST 24 HOURS. THE 00Z KTWC SOUNDING HAD A RATHER STABLE
TEMPERATURE PROFILE WITH LITTLE SHEAR AND A MODEST SOUTHERLY FLOW.
THE OUTFLOW ORIENTATION OF THE COMPLEX IN SONORA IS PRIMARILY TOWARD
THE GULF OF CALIFORNIA AND MAY NOT END UP PROVIDING AS MUCH INPUT TO
OVERNIGHT AND MORNING CONVECTION AS PREVIOUS EVENINGS. THE HRRR IS
BOUNCING WITH THIS IDEA FROM RUN-TO-RUN HOWEVER.
EVEN WITH A LITTLE LESS MOISTURE TO WORK WITH AS A TREND INTO THE
WEEKEND...WE WILL HAVE PLENTY TO DO THE JOB FOR THE FORESEEABLE
FUTURE. RELATIVELY HIGH LATITUDE INVERTED TROUGH TO MAKE THINGS
INTERESTING NEXT WEEK.
&&
.PREV DISCUSSION...WELL TODAY WAS INTERESTING. A WONDERFUL MCS
PUSHED NORTH ACROSS PIMA AND PINAL COUNTIES PROVIDING WIDESPREAD
BENEFICIAL RAINFALL. REPORTS GENERALLY RANGED FROM AROUND A TENTH UP
TO A HALF INCH ACROSS TUCSON...WITH THE MAX REPORTS AROUND FLORANCE
WITH OVER 2.5 INCHES OBSERVED. THINKING THE ATMOSPHERE IS NOW PRETTY
WORKED OVER IN THE CENTRAL ZONES SO THE BEST SHOT AT ANY CONVECTION
THIS AFTERNOON WOULD BE OVER COCHISE AND UP THROUGH GRAHAM AND
GREENLEE COUNTIES. ISOLATED ACTIVITY CAN NOT BE RULED OUT IN PIMA
AND COCHISE COUNTIES GIVEN THE RAPID WARMING WE HAVE EXPERIENCED IN
THE LAST FEW HOURS. THE HRRR ONLY HINTS AT A FEW STORMS THOUGH SO I
LOWERED PRECIP CHANCES A LITTLE THROUGH MIDNIGHT.
MODELS CONTINUE TO SHOW A DRYING TREND THROUGH SUNDAY. MID LEVEL DRY
AIR ADVECTION BRINGS OUR PRECIPITABLE WATER VALUES DOWN A FEW TENTHS
TOMORROW BUT THAT STILL LEAVES PLENTY OF MOISTURE FOR STORMS GIVEN
ENOUGH DAYTIME HEATING. WE ARE EXPECTING BETTER HEATING TOMORROW
ESPECIALLY IF WE CAN KEEP THE SKY CLEAR DURING THE MORNING HOURS.
MODELS SHOW LESS ACTIVITY OVER THE SIERRA MADRES TONIGHT SO THAT
WOULD SUGGEST FEWER CLOUDS IN THE MORNING. PLUS...THEIR IS A WEAK
PVU ANOMALY THAT MOVES INTO SE AZ AROUND 00Z SUNDAY. WRF DATA BREAKS
OUT PRECIP AROUND 3 PM TOMORROW AND THAT SEEMS REASONABLE.
MID LEVEL FLOW REALLY PULLS IN DRIER AIR SUNDAY AND DROPS OUR
PRECIPITABLE WATER VALUES DOWN TO AROUND 1.3 INCHES. THIS IS A
RESULT OF THE MONSOON RIDGE SPLITTING INTO TWO LOBES WITH ONE HIGH
PARKING OVER AZ/NM REGION WITH THE SECOND HIGH OVER THE NORTHEAST
UNITED STATES. WE SHOULD SEE A WARMING TREND IN ADDITION TO THE
DRIER CONDITIONS.
AFTER THAT...OUR PATTERN HAS THE POTENTIAL TO BECOME WET BY TUESDAY.
HERE IS WHAT WE DO KNOW ABOUT THE MID WEEK SYSTEM. FIRST...THE
OPERATIONAL GFS/ECMWF/CANADIAN ALL SHOW AN EASTERLY MOVING TROUGH AT
AROUND 40 DEG. LATITUDE STARTING OVER OHIO VALLEY ON SATURDAY AND
REACHING NEW MEXICO BY TUE. ENSEMBLE DATA SUPPORT THIS IDEA AS WELL.
WE ALSO KNOW THE MODELS ARE PROJECTING INCREASED MOISTURE WITH THIS
SYSTEM. MY CONCERN IS THE MOISTURE SOURCE. IT APPEARS THE MODELS ARE
TRYING TO RECYCLE THE MOISTURE AS IT TRAVELS AROUND OUR RIDGE THIS
WEEKEND. THE MOIST AIR TRAVELS NORTH INTO CANADA...THEN MOVES
SOUTH OVER COLORADO AND NEW MEXICO AS THE HIGH SPLITS AND PROVIDES
MORE NORTHEAST FLOW ALOFT INTO THE SW UNITED STATES. I WOULD THINK
SOME OF THE MOISTURE WOULD DISSIPATE ALONG THIS TRACK BUT THE MODELS
ARE ADAMANT THAT MOISTURE WILL BE AVAILABLE. EVENTUALLY...THERE IS A
MID LEVEL MOISTURE TAP INTO THE GULF OF MEXICO BUT THAT WOULD BE
LATE WEDNESDAY INTO THURSDAY.
SO WITH THAT IN MIND...I INCREASED RAIN CHANCES BY 5 OR 10 PERCENT
ON TUESDAY AND WEDNESDAY AND I AM CONCERNED THAT HEAVY RAIN WILL BE
POSSIBLE SOMETIME NEXT WEEK. THE EXACT TIME AND LOCATIONS ARE STILL
UP IN THE AIR THOUGH. IF THE GFS IS RIGHT...THEN WE NEED TO WATCH
FOR HEAVY RAIN AND FLOODING ON TUESDAY AND WEDNESDAY BUT COULD START
AS EARLY AS MONDAY NIGHT. EITHER WAY...NEXT WEEK LOOKS VERY
INTERESTING.
JJB
&&
.AVIATION...THUNDERSTORM ACTIVITY WILL BE LIMITED THROUGH THE
EVENING HOURS BUT SHOWERS OR THUNDERSTORMS MAY REDEVELOP AFTER 06Z.
OUTSIDE OF THE STORMS...VFR CIGS ARE ANTICIPATED WITH BKN100-120
DEVELOPING AFTER 04Z. WINDS WILL FOLLOW NORMAL DIURNAL TRENDS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY AFTERNOON THROUGH EARLY MORNING
SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A DIMINISHING
TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL PRODUCE
GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF THE
THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. DAYTIME RELATIVE HUMIDITIES
WILL RANGE FROM THE 20S TO 40S WITH GOOD NIGHTTIME RECOVERIES. A
SLIGHT DRYING TREND IS EXPECTED LATE THIS WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
230 PM MST THU JUL 11 2013
...UPDATED TO AVIATION AND FIRE WEATHER DISCUSSION...
&&
.SYNOPSIS...
FAVORABLE SOUTHERLY FLOW WILL CONTINUE TO IMPORT DEEPER MONSOON
MOISTURE INTO THE REGION OVER THE NEXT COUPLE DAYS. THIS WILL LEAD
TO MORE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA
LASTING THROUGH FRIDAY. THE INCREASED MOISTURE WILL ALSO RESULT IN
COOLER DAYTIME TEMPERATURES FOR THE REST OF THE WORK WEEK. WARMER
TEMPERATURES AND A GENERAL DECREASE IN THUNDERSTORM ACTIVITY CAN BE
EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION.../ISSUED 216 PM MST THU JUL 11/
SMALL DAY TO DAY CHANGES IN THE ATMOSPHERIC PROFILE CAN MAKE A WORLD
OF DIFFERENCE IN THE CONVECTIVE POTENTIAL. THIS IS CERTAINLY THE
CASE FOR THE SOUTHWEST MONSOON. ALTHOUGH IT WOULD HAVE APPEARED
YESTERDAY THAT ALL THE KEY INGREDIENTS WERE IN PLACE FOR DEVELOPMENT
OF MORE WIDESPREAD CONVECTION ACROSS THE FORECAST AREA...ONLY A FEW
STORMS MANAGED TO WORK THEIR WAY INTO EAST CENTRAL AZ DESERTS. LA
PAZ AND YUMA COUNTIES AND POINTS WEST DID SEE MORE WIDESPREAD
COVERAGE OF SHOWERS AND STORMS...WITH ADDITIONAL DYNAMICS PROVIDED
BY A LOW AND INVERTED TROUGH SWEEPING ALONG THE INTERNATIONAL
BORDER IN THE VICINITY OF THE INTERNATIONAL BORDER. THE LATEST 19Z
K1Y8 (YUMA) SOUNDING SHOWS A PROFILE RIPE FOR STORMS...WITH A STRONG
SOUTHERLY FLOW...PWAT OF 1.86 INCH...AND CAPE OF OVER 1600 J/JG.
THERE IS SOME CONVECTIVE INHIBITION...BUT THIS SHOULDN/T KEEP MORE
SHOWERS AND STORMS FROM DEVELOPING AGAIN THIS AFTERNOON AND EVENING.
A FEW SHOWERS AND STORMS ARE STILL CONTINUING IN LA PAZ AND
RIVERSIDE COUNTIES...AND THE HRRR WHICH PERFORMED THE BEST OF
MESOSCALE MODELS WITH THE EARLY MORNING CONVECTION SHOWS CONVECTION
CONTINUING IN THIS REGION FOR THE NEXT SEVERAL HOURS. MEANWHILE IN
EAST CENTRAL AZ STORMS BEGAN DEVELOPING EARLY OVER PIMA COUNTY AND
ATTEMPTED MOVED NORTH INTO PINAL COUNTY. EARLY STORMS QUICKLY
DISSIPATED BEFORE THEY COULD WORK THEIR WAY INTO THE PHOENIX
FORECAST AREA. CLOUD COVER REMAINED OVER EAST CENTRAL ARIZONA FOR
MUCH OF THE DAY. THIS KEPT TEMPERATURES SEVERAL DEGREES COOLER THAN
ON WEDNESDAY FOR MOST OF THE DAY. IN THE LAST COUPLE OF HOURS CLOUD
COVER HAS BEGUN SCATTERING OUT THOUGH...TEMPERATURES HAVE BEGUN
CLIMBING AND THE AIRMASS HAS BECOME MORE UNSTABLE. THIS WILL LIKELY
ALLOW A FEW STORMS TO WORK THEIR WAY FURTHER INTO THE DESERT
SOUTHWEST. WITH PWAT NEAR TWO INCHES...STORMS THAT DO DEVELOP HAVE
THE POTENTIAL TO PRODUCE LOCALIZED HEAVY RAINFALL. THERE REMAINS A
THREAT OF BLOWING DUST ALONG THE I-10 AND I-8 CORRIDORS IN EAST
CENTRAL ARIZONA AS OUTFLOW BOUNDARIES WORKING THEIR WAY NORTH AHEAD
OF STORMS PUSHING NORTH OUT OF PIMA COUNTY.
DO NOT HAVE GOOD CONFIDENCE IN FRIDAYS FORECAST. MOISTURE AND
INSTABILITY WILL REMAIN SUFFICIENT...THOUGH AS NOTED ABOVE LITTLE
CHANGES IN THE VERTICAL PROFILE CAN MAKE BIG DIFFERENCES IN WHETHER
CONVECTION DEVELOPS. SHOULD CONVECTION BECOME FAIRLY WIDESPREAD THIS
EVENING AND CLOUD COVER REMAIN OVER THE REGION AGAIN ON
FRIDAY...THAN LOW GRADE MONSOON ACTIVITY COULD BE THE RESULT. ON THE
OTHER HAND...IF TODAY IS NOT REAL ACTIVE AND TEMPERATURES ARE ABLE
TO RISE SUFFICIENTLY DURING THE DAY TOMORROW...FRIDAY COULD TURN
INTO A MORE ACTIVE DAY. THE ECMWF AND GFS DO SHOW PWAT AND
INSTABILITY TRENDING DOWN AS THE RIDGE SHUNTS EAST AND FLOW BECOMES
DRIER...IN RESPONSE TO A TROUGH WORKING ITS WAY INTO THE PACIFIC
NORTHWEST. AS SUCH...KEPT POPS WE HAD IN OUR EARLIER PACKAGE
GOING...WITH HIGHEST VALUES IN THE HIGHER TERRAIN OF EAST CENTRAL
ARIZONA.
A SUBTLE SHIFT IN THE OVERALL CONUS FLOW PATTERN WILL TAKE PLACE
OVER THE WEEKEND...AS A PROGRESSIVE ERN PACIFIC/PAC NW TROUGH
TRANSLATES INTO SOUTHERN CANADA CAUSING A RETROGRESSION OF FEATURES
SOUTH OF THE PRIMARY NORTHERN STREAM JET. AS SUCH...AN H5 594DM
RIDGE AXIS WILL SETTLE BACK OVER ARIZONA BRINGING A SLIGHT DRYING
TREND AND MORE LARGE SCALE SUBSIDENCE. ABOVE NORMAL TEMPERATURES AND
LOWER PRECIPITATION CHANCES OUTSIDE OF SOUTHERN GILA COUNTY APPEAR
MOST LIKELY THROUGH AT LEAST MONDAY.
BOTH THE OPERATIONAL GFS AND ECMWF NOW SHOW THE AFOREMENTIONED RIDGE
AXIS PERSISTING ACROSS THE AREA MUCH LONGER THAN PREVIOUSLY
FORECAST...WITH AN INVERTED TROUGH DECAYING AND BECOMING DEFLECTED
WELL SOUTH INTO MEXICO THROUGH THE MIDDLE OF NEXT WEEK (AS OPPOSED
TO PREVIOUS FORECASTS BRINGING A CIRCULATION CENTER DIRECTLY OVER
THE FORECAST AREA). WHILE FORECAST CONFIDENCE IN NOT OVERWHELMINGLY
HIGH...THE MODEL TREND DOES SUPPORT A FORECAST TOWARDS WARMER
TEMPERATURES AND LOWER PRECIPITATION CHANCES EVEN INTO THE MIDDLE OF
NEXT WEEK. HAVE NOT YET FULLY BOUGHT INTO THE MAGNITUDE OF WARMTH
ADVERTISED BY NUMERICAL GUIDANCE...BUT HAVE CERTAINLY INCREASED
VALUES TO A NEAR NORMAL THRESHOLD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
SHOWERS AND THUNDERSTORMS POSSIBLE LATE THIS AFTERNOON AND EVENING
APPROACHING THE PHOENIX AIRFIELDS...MORE CONFIDENCE IN CHANCES TO
THE EAST NEAR KIWA...SO HAVE NEGLECTED TO INCLUDE MENTION IN THE
KPHX OR KSDL TAFS. DUE TO THE VERY MOIST ENVIRONMENT...CHANCES FOR
STRONG OUTFLOW WINDS AND BLOWING DUST REMAIN VERY SLIGHT TODAY.
OVERALL...WINDS TO FAVOR A WESTERLY DIRECTION FOR MOST OF THE
PERIOD.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO AFFECT THE AREA
THIS AFTERNOON AND EVENING HOURS...ESPECIALLY AT KBLH. OVERALL WINDS
WILL REMAIN SOUTHERLY TO SOUTHEASTERLY IN NATURE WITH PERIODIC
AFTERNOON GUSTS TO NEAR 20KTS POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
A DRYING TREND WILL KEEP STORM CHANCES MAINLY CONFINED TO THE HIGHER
TERRAIN NORTH AND EAST OF PHOENIX SUNDAY AND MONDAY. MINIMUM
HUMIDITY VALUES IN THE TEENS WILL PERSIST ACROSS THE LOWER DESERTS
FOR SUNDAY AND MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM
VALUES WILL IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE
WITH ANOTHER INCREASE IN MOISTURE. OVERNIGHT RECOVERY SHOULD BE GOOD
TO EXCELLENT WITH READINGS CLIMBING ABOVE 40 PERCENT MOST NIGHTS.
DAYTIME GUSTY WINDS ARE POSSIBLE EACH DAY...ALONG WITH POSSIBLE
THUNDERSTORM OUTFLOW BOUNDARY WINDS ON SATURDAY AND AGAIN TUESDAY
AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/MO
AVIATION...CDEWEY
FIRE WEATHER...CDEWEY
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
216 PM MST THU JUL 11 2013
.SYNOPSIS...
FAVORABLE SOUTHERLY FLOW WILL CONTINUE TO IMPORT DEEPER MONSOON
MOISTURE INTO THE REGION OVER THE NEXT COUPLE DAYS. THIS WILL LEAD
TO MORE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA
LASTING THROUGH FRIDAY. THE INCREASED MOISTURE WILL ALSO RESULT IN
COOLER DAYTIME TEMPERATURES FOR THE REST OF THE WORK WEEK. WARMER
TEMPERATURES AND A GENERAL DECREASE IN THUNDERSTORM ACTIVITY CAN BE
EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
SMALL DAY TO DAY CHANGES IN THE ATMOSPHERIC PROFILE CAN MAKE A WORLD
OF DIFFERENCE IN THE CONVECTIVE POTENTIAL. THIS IS CERTAINLY THE
CASE FOR THE SOUTHWEST MONSOON. ALTHOUGH IT WOULD HAVE APPEARED
YESTERDAY THAT ALL THE KEY INGREDIENTS WERE IN PLACE FOR DEVELOPMENT
OF MORE WIDESPREAD CONVECTION ACROSS THE FORECAST AREA...ONLY A FEW
STORMS MANAGED TO WORK THEIR WAY INTO EAST CENTRAL AZ DESERTS. LA
PAZ AND YUMA COUNTIES AND POINTS WEST DID SEE MORE WIDESPREAD
COVERAGE OF SHOWERS AND STORMS...WITH ADDITIONAL DYNAMICS PROVIDED
BY A LOW AND INVERTED TROUGH SWEEPING ALONG THE INTERNATIONAL
BORDER IN THE VICINITY OF THE INTERNATIONAL BORDER. THE LATEST 19Z
K1Y8 (YUMA) SOUNDING SHOWS A PROFILE RIPE FOR STORMS...WITH A STRONG
SOUTHERLY FLOW...PWAT OF 1.86 INCH...AND CAPE OF OVER 1600 J/JG.
THERE IS SOME CONVECTIVE INHIBITION...BUT THIS SHOULDN/T KEEP MORE
SHOWERS AND STORMS FROM DEVELOPING AGAIN THIS AFTERNOON AND EVENING.
A FEW SHOWERS AND STORMS ARE STILL CONTINUING IN LA PAZ AND
RIVERSIDE COUNTIES...AND THE HRRR WHICH PERFORMED THE BEST OF
MESOSCALE MODELS WITH THE EARLY MORNING CONVECTION SHOWS CONVECTION
CONTINUING IN THIS REGION FOR THE NEXT SEVERAL HOURS. MEANWHILE IN
EAST CENTRAL AZ STORMS BEGAN DEVELOPING EARLY OVER PIMA COUNTY AND
ATTEMPTED MOVED NORTH INTO PINAL COUNTY. EARLY STORMS QUICKLY
DISSIPATED BEFORE THEY COULD WORK THEIR WAY INTO THE PHOENIX
FORECAST AREA. CLOUD COVER REMAINED OVER EAST CENTRAL ARIZONA FOR
MUCH OF THE DAY. THIS KEPT TEMPERATURES SEVERAL DEGREES COOLER THAN
ON WEDNESDAY FOR MOST OF THE DAY. IN THE LAST COUPLE OF HOURS CLOUD
COVER HAS BEGUN SCATTERING OUT THOUGH...TEMPERATURES HAVE BEGUN
CLIMBING AND THE AIRMASS HAS BECOME MORE UNSTABLE. THIS WILL LIKELY
ALLOW A FEW STORMS TO WORK THEIR WAY FURTHER INTO THE DESERT
SOUTHWEST. WITH PWAT NEAR TWO INCHES...STORMS THAT DO DEVELOP HAVE
THE POTENTIAL TO PRODUCE LOCALIZED HEAVY RAINFALL. THERE REMAINS A
THREAT OF BLOWING DUST ALONG THE I-10 AND I-8 CORRIDORS IN EAST
CENTRAL ARIZONA AS OUTFLOW BOUNDARIES WORKING THEIR WAY NORTH AHEAD
OF STORMS PUSHING NORTH OUT OF PIMA COUNTY.
DO NOT HAVE GOOD CONFIDENCE IN FRIDAYS FORECAST. MOISTURE AND
INSTABILITY WILL REMAIN SUFFICIENT...THOUGH AS NOTED ABOVE LITTLE
CHANGES IN THE VERTICAL PROFILE CAN MAKE BIG DIFFERENCES IN WHETHER
CONVECTION DEVELOPS. SHOULD CONVECTION BECOME FAIRLY WIDESPREAD THIS
EVENING AND CLOUD COVER REMAIN OVER THE REGION AGAIN ON
FRIDAY...THAN LOW GRADE MONSOON ACTIVITY COULD BE THE RESULT. ON THE
OTHER HAND...IF TODAY IS NOT REAL ACTIVE AND TEMPERATURES ARE ABLE
TO RISE SUFFICIENTLY DURING THE DAY TOMORROW...FRIDAY COULD TURN
INTO A MORE ACTIVE DAY. THE ECMWF AND GFS DO SHOW PWAT AND
INSTABILITY TRENDING DOWN AS THE RIDGE SHUNTS EAST AND FLOW BECOMES
DRIER...IN RESPONSE TO A TROUGH WORKING ITS WAY INTO THE PACIFIC
NORTHWEST. AS SUCH...KEPT POPS WE HAD IN OUR EARLIER PACKAGE
GOING...WITH HIGHEST VALUES IN THE HIGHER TERRAIN OF EAST CENTRAL
ARIZONA.
A SUBTLE SHIFT IN THE OVERALL CONUS FLOW PATTERN WILL TAKE PLACE
OVER THE WEEKEND...AS A PROGRESSIVE ERN PACIFIC/PAC NW TROUGH
TRANSLATES INTO SOUTHERN CANADA CAUSING A RETROGRESSION OF FEATURES
SOUTH OF THE PRIMARY NORTHERN STREAM JET. AS SUCH...AN H5 594DM
RIDGE AXIS WILL SETTLE BACK OVER ARIZONA BRINGING A SLIGHT DRYING
TREND AND MORE LARGE SCALE SUBSIDENCE. ABOVE NORMAL TEMPERATURES AND
LOWER PRECIPITATION CHANCES OUTSIDE OF SOUTHERN GILA COUNTY APPEAR
MOST LIKELY THROUGH AT LEAST MONDAY.
BOTH THE OPERATIONAL GFS AND ECMWF NOW SHOW THE AFOREMENTIONED RIDGE
AXIS PERSISTING ACROSS THE AREA MUCH LONGER THAN PREVIOUSLY
FORECAST...WITH AN INVERTED TROUGH DECAYING AND BECOMING DEFLECTED
WELL SOUTH INTO MEXICO THROUGH THE MIDDLE OF NEXT WEEK (AS OPPOSED
TO PREVIOUS FORECASTS BRINGING A CIRCULATION CENTER DIRECTLY OVER
THE FORECAST AREA). WHILE FORECAST CONFIDENCE IN NOT OVERWHELMINGLY
HIGH...THE MODEL TREND DOES SUPPORT A FORECAST TOWARDS WARMER
TEMPERATURES AND LOWER PRECIPITATION CHANCES EVEN INTO THE MIDDLE OF
NEXT WEEK. HAVE NOT YET FULLY BOUGHT INTO THE MAGNITUDE OF WARMTH
ADVERTISED BY NUMERICAL GUIDANCE...BUT HAVE CERTAINLY INCREASED
VALUES TO A NEAR NORMAL THRESHOLD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ISOLATED SHOWERS ACROSS THE METRO PHOENIX AREA SHOULD COME TO AN END
BY AROUND SUNRISE. COULD SEE ADDITIONAL SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING...BUT MORE LIKELY THAN NOT THEY WILL
NOT DIRECTLY AFFECT PHOENIX TAF SITES. DUE TO THE VERY MOIST
ENVIRONMENT...CHANCES FOR STRONG OUTFLOW WINDS AND BLOWING DUST ARE
ONLY VERY SLIGHT TODAY. OVERALL...WINDS WILL FOLLOW A WESTERLY
DIRECTION FOR MOST OF THE PERIOD.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT THE REGION THROUGH
MUCH OF THE MORNING HOURS...ESPECIALLY AT KBLH. THERE SHOULD BE A
BREAK IN THE SHOWER ACTIVITY BY LATE MORNING...BUT ADDITIONAL SHOWER
AND THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON. OVERALL WINDS
WILL REMAIN SOUTHERLY TO SOUTHEASTERLY IN NATURE WITH PERIODIC
AFTERNOON GUSTS TO NEAR 20KTS POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
CHANCES FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL REMAIN INTO THE EARLY WEEKEND...BUT A DRYING TREND WILL KEEP
STORMS MAINLY CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX SUNDAY AND MONDAY. THE DRYING TREND WILL BRING MINIMUM
HUMIDITIES INTO THE TEENS ACROSS THE LOWER DESERTS FOR SUNDAY AND
MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM VALUES WILL
IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE. OVERNIGHT
RECOVERY SHOULD BE GOOD TO EXCELLENT WITH READINGS CLIMBING ABOVE 40
PERCENT MOST NIGHTS. DAYTIME GUSTY WINDS ARE POSSIBLE EACH
DAY...ALONG WITH POSSIBLE THUNDERSTORM OUTFLOW BOUNDARY WINDS ON
SATURDAY AND AGAIN TUESDAY AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/MO
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
957 AM MST THU JUL 11 2013
.SYNOPSIS...
FAVORABLE SOUTHERLY FLOW WILL CONTINUE TO IMPORT DEEPER MONSOON
MOISTURE INTO THE REGION OVER THE NEXT COUPLE DAYS. THIS WILL LEAD
TO MORE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA
LASTING THROUGH FRIDAY. THE INCREASED MOISTURE WILL ALSO RESULT IN
COOLER DAYTIME TEMPERATURES FOR THE REST OF THE WORK WEEK. WARMER
TEMPERATURES AND A GENERAL DECREASE IN THUNDERSTORM ACTIVITY CAN BE
EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
RADAR THIS MORNING SHOWS BROAD AREA OF WEAK CONVECTION PROPAGATING
FROM THE SOUTHEAST TO NORTHWEST OVER PORTIONS OF LA PAZ...RIVERSIDE
AND IMPERIAL COUNTIES. THIS CONVECTION IS BEING TRIGGERED IN PART BY
INVERTED TROUGH NOTED IN OUR EARLIER DISCUSSION. RADAR ESTIMATES AN
AVERAGE OF ONE AND ONE HALF INCHES HAVE FALLEN IN THIS AREA SINCE
EARLY THIS MORNING...THOUGH CURRENT RAINFALL RATES ARE AROUND 4
TENTHS OF AN INCH PER HOUR. THIS CONVECTION IS EXPECTED TO GRADUALLY
WORK ITS WAY OUT OF THE FORECAST AREA BY EARLY AFTERNOON.
MORNING SOUNDINGS FOR K1Y7 (YUMA) AND KPSR (PHOENIX) BOTH SHOW PWAT
IN EXCESS OF 2 INCHES. BOTH ALL SHOW ABUNDANT CAPE AVAILABLE FOR
STORMS TO TAP...THOUGH IN THE PHOENIX SOUNDING STILL SHOWED SOME
CAPPING AROUND 750 MB. THE PRESENCE OF THE CAP IS ALSO SUPPORTED BY
LOCAL ACARS DATA. THIS WILL NEED TO ERODE AND TEMPERATURES WILL NEED
TO RISE QUITE A BIT MORE TO SUPPORT CONVECTION OVER THE EAST CENTRAL
AZ DESERTS. DENSE CLOUD COVER OVER THE REGION COULD KEEP CONVECTIVE
TEMPERATURES FROM BEING REALIZED. IN CONTRAST...SOUTHWEST ARIZONA
AND SOUTHEAST CALIFORNIA COULD BE BETTER PRIMED FOR ANOTHER ROUND
OF STORMS THIS AFTERNOON AND EVENING. THE YUMA MORNING SOUNDING
SHOWS SIGNIFICANT COOLING IN THE MID LEVELS DURING THE LAST 24-HOURS
AND LITTLE CAPPING. DO NOT BELIEVE THIS REGION WAS WORKED OVER
ENOUGH WITH THE OVERNIGHT STORMS TO PRECLUDE A REPEAT PERFORMANCE
AGAIN TODAY.
UPDATE ALREADY OUT. BIGGEST CHANGE WAS TO REDUCE TEMPERATURES
SEVERAL DEGREES IN MANY AREAS AS OBSERVATIONS WERE TRACKING QUITE A
BIT COOLER THAN IN OUR FORECAST GRIDS. THE COOLER TEMPS ARE THE
RESULT OF THE DENSE CLOUD COVER...SHOWERS...AND STORMS. DON/T EXPECT
WE WILL SEE OUR TYPICAL DIURNAL TEMPERATURE CURVES FOR MUCH OF THE
FORECAST AREA TODAY.
&&
.PREV DISCUSSION...
ISSUED AT 430 AM MST THU JUL 11 2013
A BROAD SYNOPTIC SCALE INVERTED TROUGH CONTINUES TO PROPAGATE
WESTWARD TOWARDS THE GULF OF CALIFORNIA...WITH SMALL VORTICITY
CENTERS (POSSIBLY CONVECTIVELY ENHANCED) ALONG THE INTERNATIONAL
BORDER HELPING FORCE LARGE SCALE ASCENT AND CONVECTION THROUGH
SOUTHERN ARIZONA. DESPITE FAVORABLE MOISTURE PROFILES PER 00Z
SOUNDING DATA (DEEP WELL MIXED 11-14 G/KG OF MOISTURE)...WEAK
CAPPING AROUND 750MB STILL EXISTED PRECLUDING ORGANIZED STORMS FROM
SURVIVING OFF HIGHER TERRAIN. HOWEVER...OBJECTIVE ANALYSIS DEPICTS A
GENERAL COOLING AND MOISTENING OF THE ATMOSPHERIC COLUMN THROUGH
THE MORNING HOURS...LARGELY ERODING INHIBITION AND SUPPORTING
ISOLD/SCT SHOWER AND STORMS THROUGH MUCH OF THE CNTRL AND ERN PARTS
OF THE FORECAST AREA.
ONCE AGAIN EARLY THIS MORNING...NEAR TERM HRRR REFLECTIVITY
FORECASTS HAVE CAPTURED THE GENERAL TREND OF THE CURRENT
ACTIVITY...WITH SREF PROBABILITIES...DETERMINISTIC ECMWF...AND NMM
HIGH RESOLUTION CORE FORECASTS MOST AGGRESSIVE IN EXPANSION OF
ECHOES/QPF THROUGH SWRN ARIZONA THROUGH 18Z. GIVEN CURRENT RADAR
TENDS...COULD NOT DISCOUNT THESE MORE BULLISH SOLUTIONS...AND HAVE
RAISED POPS INTO A HIGHER CHANCE CATEGORY. MAY NEED FURTHER
REVISIONS/EXPANSION OF POPS UPDATED LATER THIS MORNING SHOULD TRENDS
CHANGE.
OTHERWISE...NOT A TREMENDOUS AMOUNT OF CONFIDENCE IN THE REMAINDER
OF THE FORECAST THIS AFTERNOON AND EVENING...PARTICULARLY REGARDING
CONVECTIVE EVOLUTION. STRANGELY...MANY OF THE MODELS TRADITIONALLY
BULLISH ON CONVECTION AND WITH HIGH FALSE ALARM RATES SHOW AN
UNUSUAL DEARTH OF RAINFALL THIS AFTERNOON/EVENING. THIS MAY BE DUE
TO AN ASSUMPTION OF CONVECTIVE CONTAMINATION AND CLOUD COVER
LINGERING OVER MUCH OF THE CWA DURING PEAK HEATING. ONE DISTINCT
TREND AMONG VIRTUALLY ALL MODELS WAS MORE FOCUS OF CONVECTION OVER
SERN CALIFORNIA...AND HAVE SUBSTANTIALLY INCREASED POPS IN THIS
REGION. INTERROGATION OF FORECAST SOUNDINGS FROM YUMA-IMPERIAL
INDICATE LOW MLCAPE...YET UNCAPPED PROFILES IN A WEAKLY SHEARED
ENVIRONMENT. WHILE ORGANIZED SEVERE STORMS WOULD NOT BE
EXPECTED...T/TD SPREADS ON THE ORDER OF 40F COULD STILL SUPPORT
ISOLD HIGHER WIND GUSTS. IN ADDITION...WHILE NOT THE CLASSIC HEAVY
RAIN SOUNDING...PWATS IN EXCESS OF 1.75 INCHES JUXTAPOSED WITH
UNIDIRECTIONAL WIND PROFILES OF LITTLE VERTICAL SPEED SHEAR MAY
SUPPORT TRAINING ECHOES AND LOCALLY HEAVY RAINFALL.
DEEP SOUTHERLY FLOW AND AMPLE MOISTURE PROFILES WILL PERSIST INTO
FRIDAY...SUGGESTING ACTIVE MONSOON THUNDERSTORM ACTIVITY.
HOWEVER...RECENT MODEL OUTPUT IS NOT PARTICULARLY IMPRESSIVE
REGARDING CONVECTIVE COVERAGE FRIDAY AFTERNOON/EVENING. AT THIS
POINT...IT APPEARS THE LACK OF A DYNAMIC TRIGGER...NEUTRAL JET
STRUCTURE...AND THE FIRST SIGNS OF A RETROGRESSIVE RIDGE MAY BE TO
BLAME. WITH MANY OF THE INGREDIENTS STILL PRESENT THROUGH THE
ATMOSPHERE...COULD NOT TOTALLY ELIMINATE THE POTENTIAL FOR AN ACTIVE
EVENING...HOWEVER HAVE GENERALLY TEMPERED BACK POPS FOR ALL BUT THE
HIGHER TERRAIN LOCATIONS.
A SUBTLE SHIFT IN THE OVERALL CONUS FLOW PATTERN WILL TAKE PLACE
OVER THE WEEKEND...AS A PROGRESSIVE ERN PACIFIC/PAC NW TROUGH
TRANSLATES INTO SOUTHERN CANADA CAUSING A RETROGRESSION OF FEATURES
SOUTH OF THE PRIMARY NORTHERN STREAM JET. AS SUCH...AN H5 594DM
RIDGE AXIS WILL SETTLE BACK OVER ARIZONA BRINGING A SLIGHT DRYING
TREND AND MORE LARGE SCALE SUBSIDENCE. ABOVE NORMAL TEMPERATURES AND
LOWER PRECIPITATION CHANCES OUTSIDE OF SOUTHERN GILA COUNTY APPEAR
MOST LIKELY THROUGH AT LEAST MONDAY.
BOTH THE OPERATIONAL GFS AND ECMWF NOW SHOW THE AFOREMENTIONED RIDGE
AXIS PERSISTING ACROSS THE AREA MUCH LONGER THAN PREVIOUSLY
FORECAST...WITH AN INVERTED TROUGH DECAYING AND BECOMING DEFLECTED
WELL SOUTH INTO MEXICO THROUGH THE MIDDLE OF NEXT WEEK (AS OPPOSED
TO PREVIOUS FORECASTS BRINGING A CIRCULATION CENTER DIRECTLY OVER
THE FORECAST AREA). WHILE FORECAST CONFIDENCE IN NOT OVERWHELMINGLY
HIGH...THE MODEL TREND DOES SUPPORT A FORECAST TOWARDS WARMER
TEMPERATURES AND LOWER PRECIPITATION CHANCES EVEN INTO THE MIDDLE OF
NEXT WEEK. HAVE NOT YET FULLY BOUGHT INTO THE MAGNITUDE OF WARMTH
ADVERTISED BY NUMERICAL GUIDANCE...BUT HAVE CERTAINLY INCREASED
VALUES TO A NEAR NORMAL THRESHOLD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ISOLATED SHOWERS ACROSS THE METRO PHOENIX AREA SHOULD COME TO AN END
BY AROUND SUNRISE. COULD SEE ADDITIONAL SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING...BUT MORE LIKELY THAN NOT THEY WILL
NOT DIRECTLY AFFECT PHOENIX TAF SITES. DUE TO THE VERY MOIST
ENVIRONMENT...CHANCES FOR STRONG OUTFLOW WINDS AND BLOWING DUST ARE
ONLY VERY SLIGHT TODAY. OVERALL...WINDS WILL FOLLOW A WESTERLY
DIRECTION FOR MOST OF THE PERIOD.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT THE REGION THROUGH
MUCH OF THE MORNING HOURS...ESPECIALLY AT KBLH. THERE SHOULD BE A
BREAK IN THE SHOWER ACTIVITY BY LATE MORNING...BUT ADDITIONAL SHOWER
AND THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON. OVERALL WINDS
WILL REMAIN SOUTHERLY TO SOUTHEASTERLY IN NATURE WITH PERIODIC
AFTERNOON GUSTS TO NEAR 20KTS POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
CHANCES FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL REMAIN INTO THE EARLY WEEKEND...BUT A DRYING TREND WILL KEEP
STORMS MAINLY CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX SUNDAY AND MONDAY. THE DRYING TREND WILL BRING MINIMUM
HUMIDITIES INTO THE TEENS ACROSS THE LOWER DESERTS FOR SUNDAY AND
MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM VALUES WILL
IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE. OVERNIGHT
RECOVERY SHOULD BE GOOD TO EXCELLENT WITH READINGS CLIMBING ABOVE 40
PERCENT MOST NIGHTS. DAYTIME GUSTY WINDS ARE POSSIBLE EACH
DAY...ALONG WITH POSSIBLE THUNDERSTORM OUTFLOW BOUNDARY WINDS ON
SATURDAY AND AGAIN TUESDAY AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MCLANE/MO
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
926 AM MST THU JUL 11 2013
.SYNOPSIS...ABUNDANT MOISTURE WILL PRODUCE SCATTERED THUNDERSTORMS
THROUGH THIS EVENING WITH ISOLATED THUNDERSTORMS CONTINUING LATE
TONIGHT. THUNDERSTORM CHANCES WILL GRADUALLY DECREASE FRIDAY THROUGH
SUNDAY. THEREAFTER...ADEQUATE MOISTURE WILL CONTINUE THE CYCLE OF
MAINLY AFTERNOON AND EVENING THUNDERSTORMS MONDAY THROUGH WEDNESDAY.
COOLER DAYTIME TEMPERATURES TODAY FOLLOWED BY A WARMING TREND INTO
EARLY NEXT WEEK.
&&
.DISCUSSION...FIRST A BRIEF RECAP FROM YESTERDAY TO FORM SOME
REFERENCE FOR TODAY. THE HI RES MODELS OVERALL DID A GOOD JOB. THE
HRRR WAS A BIT UNDERDONE FOR THE AFTERNOON CONVECTION BUT DID WELL
WITH THE OVERNIGHT STORMS. THE VARIOUS WRF RUNS HANDLED THE DAYTIME
CONVECTION BETTER BUT ALL MODELS HIT PRECIP A BIT TO HARD IN TUCSON
PROPER. GRANTED MT LEMMON HAD OVER 1.5 INCHES OF PRECIP SO THE
SOLUTIONS WERE NOT TOO FAR OFF.
THAT BEING SAID...TODAY LOOKS SIMILAR TO YESTERDAY FROM A PROFILE
PERSPECTIVE. NEARLY IDENTICAL PWATS IN PLACE AND INSTABILITY
PARAMETERS ARE VERY CLOSE. THE DIFFERENCES ARE MAINLY IN THE FLOW
AND THE TEMPS ALOFT AND DCAPE IS DOWN A BIT TODAY. THE PROFILE STORM
MOTION YESTERDAY WAS SE TO NORTHWESTERLY AT 8 TO 10 KTS...AND TODAY
THE FLOW IS MORE SOUTHERLY AND A BIT STRONGER. THE SHEAR PROFILE IS
NOT AS IMPRESSIVE TODAY AND WE ARE SITTING ON THE BACK
SIDE...DOWNWARD MOTION...OF THE EXITING MCS THAT IS NOW PUSHING
NORTH TOWARD LAS VEGAS. THOSE TWO FACTORS WOULD FAVOR A LESS ACTIVE
DAY TODAY...BUT WE ARE STILL WARM AND MOIST. CONVECTIVE TEMP TODAY
SHOULD BE AROUND 92 AND WE ARE EXPECTING 95 FOR A HIGH IN TUCSON. SO
THERE ARE BOTH PROS AND CONS FOR CONVECTION TODAY.
NOW FOR THE HI RES MODELS. THE HRRR...AS MENTIONED PREVIOUSLY...IS
HANDLING THE MCS HEADING TO LAS VEGAS PRETTY WELL AND THE
INITIALIZED SKY COVER IS DOING WELL. THE U OF A NAM WRF APPEARS
SLIGHTLY TOO CLOUDY THIS MORNING OVER NORTHERN MEXICO INTO SOUTHERN
AZ...WHILE THE GFS NAM IS DOING A BETTER JOB WITH THE CLEARING.
EITHER WAY...BOTH U OF A WRF RUNS SHOWS LIMITED DAYTIME
CONVECTION...MOSTLY WEAK PULSE CONVECTION...BUT INCREASE ACTIVITY
OVER COCHISE COUNTY BY TONIGHT AFTER 10 PM ISH. THE HRRR AGREES WITH
THE WEAK DAYTIME PULSE CONVECTION BUT THE DATA ENDS AT 04Z.
I WOULD TEND TO AGREE WITH THE WEAKER DAYTIME CONVECTION GIVE OUR
POSITION ON THE SUBSIDENT SIDE OF THE EXITING MCS. HOWEVER...WATER
VAPOR IMAGERY DOES SHOW A WEAK IMPULSE CURRENTLY OVER SOUTHEAST NEW
MEXICO OR NEAR EL PASO...MOVING THIS WAY. IT LOOKS LIKE THAT FEATURE
IS MOVING AT ABOUT 25 TO 30 KTS. SO MY TERRIBLE MATH SUGGESTS THIS
FEATURE WOULD REACH SOUTHERN AZ IN ABOUT 9 TO 12 HOURS...OR SOMETIME
THIS EVENING. THIS SEEMS TO MATCH THE WRF DATA SO I WOULD TREND
TOWARD THE BETTER ACTIVITY CHANCES OCCURRING TONIGHT INTO TOMORROW
EARLY MORNING.
THAT BEING SAID...THE ABUNDANT MOISTURE...AGAIN FLOATING ABOVE THE
90TH PERCENTILE FOR THIS TIME OF YEAR...WOULD SUGGEST HEAVY RAIN
THREAT EVEN WITH THE ISOLATED CELLS THAT FORM THIS AFTERNOON.
JJB
&&
.AVIATION...GRADUAL CLEARING FROM THE SE THROUGH 11/18Z LEAVING
BEHIND SCT140 SCT-BKN350. THEN EXPECT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS THE REGION WITH
ISOLD MVFR CONDS. A BASIC DIURNAL WIND PATTERN IS EXPECTED AWAY FROM
THUNDERSTORMS WITH ERRACTIC AND GUSTY WINDS NEAR THUNDERSTORMS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY LATE AFTERNOON THROUGH EARLY
MORNING SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A SLIGHT
DIMINISHING TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL
PRODUCE GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF
THE THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. DAYTIME RELATIVE HUMIDITIES
WILL RANGE FROM THE 20S TO 30S WITH GOOD NIGHTTIME RECOVERIES
THROUGH FRIDAY THEN THERE WILL BE A SLIGHT DRYING TREND INTO THE
WEEKEND.
&&
.PREV DISCUSSION...SCATTERED SHOWERS AND ISOLATED TSTMS ONGOING FROM
THE TUCSON METRO AREA WESTWARD TO NORTHWESTWARD INTO WRN PIMA/SOUTH
CENTRAL PINAL COUNTIES. BULK OF THIS ACTIVITY IS EXPECTED TO MOVE
OUT OF THIS FORECAST AREA AROUND 14Z. HOWEVER...THE 11/08Z RUC HRRR
DEVELOPS PRECIP ECHOES ACROSS CENTRAL/ERN PIMA COUNTY BY 17Z.
PRECIP CELLS ARE PROGGED TO BECOME MORE WIDESPREAD BY EARLY THIS
AFTERNOON AND ARE DEPICTED TO BE MOSTLY NORTH AND EAST OF TUCSON BY
22Z. THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS FROM LATE
THIS MORNING INTO THIS EVENING. HAVE MAINTAINED A SLIGHT CHANCE OF
SHOWERS/TSTMS AREA-WIDE LATE TONIGHT.
11/00Z GFS/ECMWF GENERALLY AGREE THAT UPPER HIGH CENTERED OVER THE
CENTRAL CONUS PLAINS FRI-SAT WILL MOVE TOWARD THE FOUR CORNERS
REGION EARLY NEXT WEEK. GFS/ECMWF DEPICT A GRADUAL DECREASE IN MID-
LEVEL MOISTURE THIS WEEKEND. THUS...SCATTERED AFTERNOON AND EVENING
SHOWERS/TSTMS FRI-SAT ARE FORECAST TO DECREASE IN COVERAGE SUN.
THERE WILL STILL BE ENOUGH MOISTURE FOR ISOLATED-SCATTERED SHOWERS/
TSTMS SUN AFTERNOON AND SUN EVENING.
THEREAFTER...SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS
WILL RETURN MON-WED AS THE UPPER HIGH REMAINS QUASI-STATIONARY NEAR
THE FOUR CORNERS REGION. HAVE NOTED THAT THE 11/00Z GFS/ECMWF WERE
MARKEDLY FURTHER SOUTH WITH THE PATH OF AN UPPER LEVEL LOW PRESSURE
SYSTEM VERSUS PREVIOUS SOLUTIONS. THUS...HAVE TRIMMED POPS SOMEWHAT
PARTICULARLY NEXT MON.
HIGH TEMPS TODAY WILL AVERAGE ABOUT 2-5 DEGS F COOLER VERSUS WED. A
WARMING TREND WILL THEN OCCUR FRI-MON FOLLOWED BY COOLER DAYTIME
TEMPS TUE-WED.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...BROST
AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
430 AM MST THU JUL 11 2013
.UPDATE...UPDATED AVIATION AND FIRE WX DISCUSSIONS.
&&
.SYNOPSIS...
FAVORABLE SOUTHERLY FLOW WILL CONTINUE TO IMPORT DEEPER MONSOON
MOISTURE INTO THE REGION OVER THE NEXT COUPLE DAYS. THIS WILL LEAD
TO MORE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA
LASTING THROUGH FRIDAY. THE INCREASED MOISTURE WILL ALSO RESULT IN
COOLER DAYTIME TEMPERATURES FOR THE REST OF THE WORK WEEK. WARMER
TEMPERATURES AND A GENERAL DECREASE IN THUNDERSTORM ACTIVITY CAN BE
EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
A BROAD SYNOPTIC SCALE INVERTED TROUGH CONTINUES TO PROPAGATE
WESTWARD TOWARDS THE GULF OF CALIFORNIA...WITH SMALL VORTICITY
CENTERS (POSSIBLY CONVECTIVELY ENHANCED) ALONG THE INTERNATIONAL
BORDER HELPING FORCE LARGE SCALE ASCENT AND CONVECTION THROUGH
SOUTHERN ARIZONA. DESPITE FAVORABLE MOISTURE PROFILES PER 00Z
SOUNDING DATA (DEEP WELL MIXED 11-14 G/KG OF MOISTURE)...WEAK
CAPPING AROUND 750MB STILL EXISTED PRECLUDING ORGANIZED STORMS FROM
SURVIVING OFF HIGHER TERRAIN. HOWEVER...OBJECTIVE ANALYSIS DEPICTS A
GENERAL COOLING AND MOISTENING OF THE ATMOSPHERIC COLUMN THROUGH
THE MORNING HOURS...LARGELY ERODING INHIBITION AND SUPPORTING
ISOLD/SCT SHOWER AND STORMS THROUGH MUCH OF THE CNTRL AND ERN PARTS
OF THE FORECAST AREA.
ONCE AGAIN EARLY THIS MORNING...NEAR TERM HRRR REFLECTIVITY
FORECASTS HAVE CAPTURED THE GENERAL TREND OF THE CURRENT
ACTIVITY...WITH SREF PROBABILITIES...DETERMINISTIC ECMWF...AND NMM
HIGH RESOLUTION CORE FORECASTS MOST AGGRESSIVE IN EXPANSION OF
ECHOES/QPF THROUGH SWRN ARIZONA THROUGH 18Z. GIVEN CURRENT RADAR
TENDS...COULD NOT DISCOUNT THESE MORE BULLISH SOLUTIONS...AND HAVE
RAISED POPS INTO A HIGHER CHANCE CATEGORY. MAY NEED FURTHER
REVISIONS/EXPANSION OF POPS UPDATED LATER THIS MORNING SHOULD TRENDS
CHANGE.
OTHERWISE...NOT A TREMENDOUS AMOUNT OF CONFIDENCE IN THE REMAINDER
OF THE FORECAST THIS AFTERNOON AND EVENING...PARTICULARLY REGARDING
CONVECTIVE EVOLUTION. STRANGELY...MANY OF THE MODELS TRADITIONALLY
BULLISH ON CONVECTION AND WITH HIGH FALSE ALARM RATES SHOW AN
UNUSUAL DEARTH OF RAINFALL THIS AFTERNOON/EVENING. THIS MAY BE DUE
TO AN ASSUMPTION OF CONVECTIVE CONTAMINATION AND CLOUD COVER
LINGERING OVER MUCH OF THE CWA DURING PEAK HEATING. ONE DISTINCT
TREND AMONG VIRTUALLY ALL MODELS WAS MORE FOCUS OF CONVECTION OVER
SERN CALIFORNIA...AND HAVE SUBSTANTIALLY INCREASED POPS IN THIS
REGION. INTERROGATION OF FORECAST SOUNDINGS FROM YUMA-IMPERIAL
INDICATE LOW MLCAPE...YET UNCAPPED PROFILES IN A WEAKLY SHEARED
ENVIRONMENT. WHILE ORGANIZED SEVERE STORMS WOULD NOT BE
EXPECTED...T/TD SPREADS ON THE ORDER OF 40F COULD STILL SUPPORT
ISOLD HIGHER WIND GUSTS. IN ADDITION...WHILE NOT THE CLASSIC HEAVY
RAIN SOUNDING...PWATS IN EXCESS OF 1.75 INCHES JUXTAPOSED WITH
UNIDIRECTIONAL WIND PROFILES OF LITTLE VERTICAL SPEED SHEAR MAY
SUPPORT TRAINING ECHOES AND LOCALLY HEAVY RAINFALL.
DEEP SOUTHERLY FLOW AND AMPLE MOISTURE PROFILES WILL PERSIST INTO
FRIDAY...SUGGESTING ACTIVE MONSOON THUNDERSTORM ACTIVITY.
HOWEVER...RECENT MODEL OUTPUT IS NOT PARTICULARLY IMPRESSIVE
REGARDING CONVECTIVE COVERAGE FRIDAY AFTERNOON/EVENING. AT THIS
POINT...IT APPEARS THE LACK OF A DYNAMIC TRIGGER...NEUTRAL JET
STRUCTURE...AND THE FIRST SIGNS OF A RETROGRESSIVE RIDGE MAY BE TO
BLAME. WITH MANY OF THE INGREDIENTS STILL PRESENT THROUGH THE
ATMOSPHERE...COULD NOT TOTALLY ELIMINATE THE POTENTIAL FOR AN ACTIVE
EVENING...HOWEVER HAVE GENERALLY TEMPERED BACK POPS FOR ALL BUT THE
HIGHER TERRAIN LOCATIONS.
A SUBTLE SHIFT IN THE OVERALL CONUS FLOW PATTERN WILL TAKE PLACE
OVER THE WEEKEND...AS A PROGRESSIVE ERN PACIFIC/PAC NW TROUGH
TRANSLATES INTO SOUTHERN CANADA CAUSING A RETROGRESSION OF FEATURES
SOUTH OF THE PRIMARY NORTHERN STREAM JET. AS SUCH...AN H5 594DM
RIDGE AXIS WILL SETTLE BACK OVER ARIZONA BRINGING A SLIGHT DRYING
TREND AND MORE LARGE SCALE SUBSIDENCE. ABOVE NORMAL TEMPERATURES AND
LOWER PRECIPITATION CHANCES OUTSIDE OF SOUTHERN GILA COUNTY APPEAR
MOST LIKELY THROUGH AT LEAST MONDAY.
BOTH THE OPERATIONAL GFS AND ECMWF NOW SHOW THE AFOREMENTIONED RIDGE
AXIS PERSISTING ACROSS THE AREA MUCH LONGER THAN PREVIOUSLY
FORECAST...WITH AN INVERTED TROUGH DECAYING AND BECOMING DEFLECTED
WELL SOUTH INTO MEXICO THROUGH THE MIDDLE OF NEXT WEEK (AS OPPOSED
TO PREVIOUS FORECASTS BRINGING A CIRCULATION CENTER DIRECTLY OVER
THE FORECAST AREA). WHILE FORECAST CONFIDENCE IN NOT OVERWHELMINGLY
HIGH...THE MODEL TREND DOES SUPPORT A FORECAST TOWARDS WARMER
TEMPERATURES AND LOWER PRECIPITATION CHANCES EVEN INTO THE MIDDLE OF
NEXT WEEK. HAVE NOT YET FULLY BOUGHT INTO THE MAGNITUDE OF WARMTH
ADVERTISED BY NUMERICAL GUIDANCE...BUT HAVE CERTAINLY INCREASED
VALUES TO A NEAR NORMAL THRESHOLD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
ISOLATED SHOWERS ACROSS THE METRO PHOENIX AREA SHOULD COME TO AN END
BY AROUND SUNRISE. COULD SEE ADDITIONAL SHOWERS AND THUNDERSTORMS
LATE THIS AFTERNOON AND EVENING...BUT MORE LIKELY THAN NOT THEY WILL
NOT DIRECTLY AFFECT PHOENIX TAF SITES. DUE TO THE VERY MOIST
ENVIRONMENT...CHANCES FOR STRONG OUTFLOW WINDS AND BLOWING DUST ARE
ONLY VERY SLIGHT TODAY. OVERALL...WINDS WILL FOLLOW A WESTERLY
DIRECTION FOR MOST OF THE PERIOD.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SHOWERS AND ISOLATED THUNDERSTORMS WILL AFFECT THE REGION THROUGH
MUCH OF THE MORNING HOURS...ESPECIALLY AT KBLH. THERE SHOULD BE A
BREAK IN THE SHOWER ACTIVITY BY LATE MORNING...BUT ADDITIONAL SHOWER
AND THUNDERSTORMS WILL BE POSSIBLE THIS AFTERNOON. OVERALL WINDS
WILL REMAIN SOUTHERLY TO SOUTHEASTERLY IN NATURE WITH PERIODIC
AFTERNOON GUSTS TO NEAR 20KTS POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
CHANCES FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL REMAIN INTO THE EARLY WEEKEND...BUT A DRYING TREND WILL KEEP
STORMS MAINLY CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX SUNDAY AND MONDAY. THE DRYING TREND WILL BRING MINIMUM
HUMIDITIES INTO THE TEENS ACROSS THE LOWER DESERTS FOR SUNDAY AND
MONDAY. BY TUESDAY OR WEDNESDAY...AFTERNOON MINIMUM VALUES WILL
IMPROVE...ONLY DROPPING INTO THE 20-30 PERCENT RANGE. OVERNIGHT
RECOVERY SHOULD BE GOOD TO EXCELLENT WITH READINGS CLIMBING ABOVE 40
PERCENT MOST NIGHTS. DAYTIME GUSTY WINDS ARE POSSIBLE EACH
DAY...ALONG WITH POSSIBLE THUNDERSTORM OUTFLOW BOUNDARY WINDS ON
SATURDAY AND AGAIN TUESDAY AND WEDNESDAY.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
300 AM MST THU JUL 11 2013
.SYNOPSIS...ABUNDANT MOISTURE WILL PRODUCE SCATTERED THUNDERSTORMS
THROUGH THIS EVENING WITH ISOLATED THUNDERSTORMS CONTINUING LATE
TONIGHT. THUNDERSTORM CHANCES WILL GRADUALLY DECREASE FRIDAY THROUGH
SUNDAY. THEREAFTER...ADEQUATE MOISTURE WILL CONTINUE THE CYCLE OF
MAINLY AFTERNOON AND EVENING THUNDERSTORMS MONDAY THROUGH WEDNESDAY.
COOLER DAYTIME TEMPERATURES TODAY FOLLOWED BY A WARMING TREND INTO
EARLY NEXT WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND ISOLATED TSTMS ONGOING FROM THE
TUCSON METRO AREA WESTWARD TO NORTHWESTWARD INTO WRN PIMA/SOUTH
CENTRAL PINAL COUNTIES. BULK OF THIS ACTIVITY IS EXPECTED TO MOVE
OUT OF THIS FORECAST AREA AROUND 14Z. HOWEVER...THE 11/08Z RUC HRRR
DEVELOPS PRECIP ECHOES ACROSS CENTRAL/ERN PIMA COUNTY BY 17Z.
PRECIP CELLS ARE PROGGED TO BECOME MORE WIDESPREAD BY EARLY THIS
AFTERNOON AND ARE DEPICTED TO BE MOSTLY NORTH AND EAST OF TUCSON BY
22Z. THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS FROM LATE
THIS MORNING INTO THIS EVENING. HAVE MAINTAINED A SLIGHT CHANCE OF
SHOWERS/TSTMS AREA-WIDE LATE TONIGHT.
11/00Z GFS/ECMWF GENERALLY AGREE THAT UPPER HIGH CENTERED OVER THE
CENTRAL CONUS PLAINS FRI-SAT WILL MOVE TOWARD THE FOUR CORNERS
REGION EARLY NEXT WEEK. GFS/ECMWF DEPICT A GRADUAL DECREASE IN MID-
LEVEL MOISTURE THIS WEEKEND. THUS...SCATTERED AFTERNOON AND EVENING
SHOWERS/TSTMS FRI-SAT ARE FORECAST TO DECREASE IN COVERAGE SUN.
THERE WILL STILL BE ENOUGH MOISTURE FOR ISOLATED-SCATTERED SHOWERS/
TSTMS SUN AFTERNOON AND SUN EVENING.
THEREAFTER...SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS
WILL RETURN MON-WED AS THE UPPER HIGH REMAINS QUASI-STATIONARY NEAR
THE FOUR CORNERS REGION. HAVE NOTED THAT THE 11/00Z GFS/ECMWF WERE
MARKEDLY FURTHER SOUTH WITH THE PATH OF AN UPPER LEVEL LOW PRESSURE
SYSTEM VERSUS PREVIOUS SOLUTIONS. THUS...HAVE TRIMMED POPS SOMEWHAT
PARTICULARLY NEXT MON.
HIGH TEMPS TODAY WILL AVERAGE ABOUT 2-5 DEGS F COOLER VERSUS WED. A
WARMING TREND WILL THEN OCCUR FRI-MON FOLLOWED BY COOLER DAYTIME
TEMPS TUE-WED.
&&
.AVIATION...GRADUAL CLEARING FROM THE SE THROUGH 11/18Z LEAVING
BEHIND SCT140 SCT-BKN350. THEN EXPECT ANOTHER ROUND OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON AND EVENING ACROSS THE REGION WITH
ISOLD MVFR CONDS. A BASIC DIURNAL WIND PATTERN IS EXPECTED AWAY FROM
THUNDERSTORMS WITH ERRACTIC AND GUSTY WINDS NEAR THUNDERSTORMS.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...SCATTERED MAINLY LATE AFTERNOON THROUGH EARLY
MORNING SHOWERS AND THUNDERSTORMS WILL CONTINUE WITH A SLIGHT
DIMINISHING TREND INTO THE WEEKEND. THE STRONGER THUNDERSTORMS WILL
PRODUCE GUSTY AND ERRATIC WINDS AND LOCALLY HEAVY RAINS. OUTSIDE OF
THE THUNDERSTORM ACTIVITY...GENERALLY NORMAL DIURNAL WIND TRENDS ARE
EXPECTED TO OCCUR THROUGH THE WEEKEND. DAYTIME RELATIVE HUMIDITIES
WILL RANGE FROM THE 20S TO 30S WITH GOOD NIGHTTIME RECOVERIES
THROUGH FRIDAY THEN THERE WILL BE A SLIGHT DRYING TREND INTO THE
WEEKEND.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRANCIS
AVIATION/FIRE WEATHER...CERNIGLIA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
255 AM MST THU JUL 11 2013
.SYNOPSIS...
FAVORABLE SOUTHERLY FLOW WILL CONTINUE TO IMPORT DEEPER MONSOON
MOISTURE INTO THE REGION OVER THE NEXT COUPLE DAYS. THIS WILL LEAD
TO MORE NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE ENTIRE AREA
LASTING THROUGH FRIDAY. THE INCREASED MOISTURE WILL ALSO RESULT IN
COOLER DAYTIME TEMPERATURES FOR THE REST OF THE WORK WEEK. WARMER
TEMPERATURES AND A GENERAL DECREASE IN THUNDERSTORM ACTIVITY CAN BE
EXPECTED OVER THE WEEKEND AND INTO EARLY NEXT WEEK.
&&
.DISCUSSION...
A BROAD SYNOPTIC SCALE INVERTED TROUGH CONTINUES TO PROPAGATE
WESTWARD TOWARDS THE GULF OF CALIFORNIA...WITH SMALL VORTICITY
CENTERS (POSSIBLY CONVECTIVELY ENHANCED) ALONG THE INTERNATIONAL
BORDER HELPING FORCE LARGE SCALE ASCENT AND CONVECTION THROUGH
SOUTHERN ARIZONA. DESPITE FAVORABLE MOISTURE PROFILES PER 00Z
SOUNDING DATA (DEEP WELL MIXED 11-14 G/KG OF MOISTURE)...WEAK
CAPPING AROUND 750MB STILL EXISTED PRECLUDING ORGANIZED STORMS FROM
SURVIVING OFF HIGHER TERRAIN. HOWEVER...OBJECTIVE ANALYSIS DEPICTS A
GENERAL COOLING AND MOISTENING OF THE ATMOSPHERIC COLUMN THROUGH
THE MORNING HOURS...LARGELY ERODING INHIBITION AND SUPPORTING
ISOLD/SCT SHOWER AND STORMS THROUGH MUCH OF THE CNTRL AND ERN PARTS
OF THE FORECAST AREA.
ONCE AGAIN EARLY THIS MORNING...NEAR TERM HRRR REFLECTIVITY
FORECASTS HAVE CAPTURED THE GENERAL TREND OF THE CURRENT
ACTIVITY...WITH SREF PROBABILITIES...DETERMINISTIC ECMWF...AND NMM
HIGH RESOLUTION CORE FORECASTS MOST AGGRESSIVE IN EXPANSION OF
ECHOES/QPF THROUGH SWRN ARIZONA THROUGH 18Z. GIVEN CURRENT RADAR
TENDS...COULD NOT DISCOUNT THESE MORE BULLISH SOLUTIONS...AND HAVE
RAISED POPS INTO A HIGHER CHANCE CATEGORY. MAY NEED FURTHER
REVISIONS/EXPANSION OF POPS UPDATED LATER THIS MORNING SHOULD TRENDS
CHANGE.
OTHERWISE...NOT A TREMENDOUS AMOUNT OF CONFIDENCE IN THE REMAINDER
OF THE FORECAST THIS AFTERNOON AND EVENING...PARTICULARLY REGARDING
CONVECTIVE EVOLUTION. STRANGELY...MANY OF THE MODELS TRADITIONALLY
BULLISH ON CONVECTION AND WITH HIGH FALSE ALARM RATES SHOW AN
UNUSUAL DEARTH OF RAINFALL THIS AFTERNOON/EVENING. THIS MAY BE DUE
TO AN ASSUMPTION OF CONVECTIVE CONTAMINATION AND CLOUD COVER
LINGERING OVER MUCH OF THE CWA DURING PEAK HEATING. ONE DISTINCT
TREND AMONG VIRTUALLY ALL MODELS WAS MORE FOCUS OF CONVECTION OVER
SERN CALIFORNIA...AND HAVE SUBSTANTIALLY INCREASED POPS IN THIS
REGION. INTERROGATION OF FORECAST SOUNDINGS FROM YUMA-IMPERIAL
INDICATE LOW MLCAPE...YET UNCAPPED PROFILES IN A WEAKLY SHEARED
ENVIRONMENT. WHILE ORGANIZED SEVERE STORMS WOULD NOT BE
EXPECTED...T/TD SPREADS ON THE ORDER OF 40F COULD STILL SUPPORT
ISOLD HIGHER WIND GUSTS. IN ADDITION...WHILE NOT THE CLASSIC HEAVY
RAIN SOUNDING...PWATS IN EXCESS OF 1.75 INCHES JUXTAPOSED WITH
UNIDIRECTIONAL WIND PROFILES OF LITTLE VERTICAL SPEED SHEAR MAY
SUPPORT TRAINING ECHOES AND LOCALLY HEAVY RAINFALL.
DEEP SOUTHERLY FLOW AND AMPLE MOISTURE PROFILES WILL PERSIST INTO
FRIDAY...SUGGESTING ACTIVE MONSOON THUNDERSTORM ACTIVITY.
HOWEVER...RECENT MODEL OUTPUT IS NOT PARTICULARLY IMPRESSIVE
REGARDING CONVECTIVE COVERAGE FRIDAY AFTERNOON/EVENING. AT THIS
POINT...IT APPEARS THE LACK OF A DYNAMIC TRIGGER...NEUTRAL JET
STRUCTURE...AND THE FIRST SIGNS OF A RETROGRESSIVE RIDGE MAY BE TO
BLAME. WITH MANY OF THE INGREDIENTS STILL PRESENT THROUGH THE
ATMOSPHERE...COULD NOT TOTALLY ELIMINATE THE POTENTIAL FOR AN ACTIVE
EVENING...HOWEVER HAVE GENERALLY TEMPERED BACK POPS FOR ALL BUT THE
HIGHER TERRAIN LOCATIONS.
A SUBTLE SHIFT IN THE OVERALL CONUS FLOW PATTERN WILL TAKE PLACE
OVER THE WEEKEND...AS A PROGRESSIVE ERN PACIFIC/PAC NW TROUGH
TRANSLATES INTO SOUTHERN CANADA CAUSING A RETROGRESSION OF FEATURES
SOUTH OF THE PRIMARY NORTHERN STREAM JET. AS SUCH...AN H5 594DM
RIDGE AXIS WILL SETTLE BACK OVER ARIZONA BRINGING A SLIGHT DRYING
TREND AND MORE LARGE SCALE SUBSIDENCE. ABOVE NORMAL TEMPERATURES AND
LOWER PRECIPITATION CHANCES OUTSIDE OF SOUTHERN GILA COUNTY APPEAR
MOST LIKELY THROUGH AT LEAST MONDAY.
BOTH THE OPERATIONAL GFS AND ECMWF NOW SHOW THE AFOREMENTIONED RIDGE
AXIS PERSISTING ACROSS THE AREA MUCH LONGER THAN PREVIOUSLY
FORECAST...WITH AN INVERTED TROUGH DECAYING AND BECOMING DEFLECTED
WELL SOUTH INTO MEXICO THROUGH THE MIDDLE OF NEXT WEEK (AS OPPOSED
TO PREVIOUS FORECASTS BRINGING A CIRCULATION CENTER DIRECTLY OVER
THE FORECAST AREA). WHILE FORECAST CONFIDENCE IN NOT OVERWHELMINGLY
HIGH...THE MODEL TREND DOES SUPPORT A FORECAST TOWARDS WARMER
TEMPERATURES AND LOWER PRECIPITATION CHANCES EVEN INTO THE MIDDLE OF
NEXT WEEK. HAVE NOT YET FULLY BOUGHT INTO THE MAGNITUDE OF WARMTH
ADVERTISED BY NUMERICAL GUIDANCE...BUT HAVE CERTAINLY INCREASED
VALUES TO A NEAR NORMAL THRESHOLD.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
MOSTLY MID LEVEL DEBRIS CIGS AON 10KFT AGL WILL PERSIST OVERNIGHT
FOR THE PHX TERMINALS. WIDESPREAD CONVECTIVE ACTIVITY ACROSS THE PHX
METRO HELD OFF ANOTHER NIGHT...BUT STILL PERSISTS ACROSS THE HIGHER
TERRAIN EAST OF PHOENIX. LIGHT SHOWERS AND ISOLATED THUNDER MAY WORK
THEIR WAY DOWN IN TO THE LOWER DESERTS AND THE PHX TERMINALS
OVERNIGHT...BUT CONFIDENCE AT THIS TIME IS TOO LOW TO WARRANT
INCLUSION IN THE 06Z TAF PACKAGE. OUTSIDE OF PASSING SHOWER
ACTIVITY...SURFACE WINDS WILL REMAIN WESTERLY OVERNIGHT BEFORE
BECOMING MORE VARIABLE IN NATURE CLOSER TOWARDS SUNRISE.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
MID TO HIGH LEVEL BKN TO OVC CIGS WILL FILTER INTO THE AREA FROM THE
EAST AND SOUTH AS CONVECTIVE ACTIVITY BACK ACROSS SOUTH CENTRAL
ARIZONA CONTINUES TO DISSIPATE. ACTIVITY MAY DRIFT WEST ENOUGH TO
GENERATE VCSH ACTIVITY NEAR KBLH BY THE EARLY MORNING HOURS. OVERALL
WINDS WILL REMAIN SOUTHEASTERLY IN NATURE WITH PERIODIC AFTERNOON
GUSTS TO NEAR 20KTS POSSIBLE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
CHANCES FOR MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
WILL REMAIN INTO THE EARLY WEEKEND...BUT A DRYING TREND WILL KEEP
STORMS MAINLY CONFINED TO THE HIGHER TERRAIN NORTH AND EAST OF
PHOENIX SUNDAY AND MONDAY. THE DRYING TREND WILL BRING MINIMUM
HUMIDITIES INTO THE TEENS ACROSS THE LOWER DESERTS FOR SUNDAY AND
MONDAY. OTHER DAYS WILL GENERALLY SEE AFTERNOON MINIMUM VALUES ONLY
DROPPING INTO THE 20-30 PERCENT RANGE. OVERNIGHT RECOVERY SHOULD BE
GOOD TO EXCELLENT WITH READINGS CLIMBING ABOVE 40 PERCENT MOST
NIGHTS. GUSTY WINDS ARE POSSIBLE EACH DAY...AS OUTFLOW BOUNDARIES
PROPAGATE AWAY FROM DEVELOPING SHOWERS AND THUNDERSTORMS.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...MO
AVIATION...NOLTE
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS EUREKA CA
428 AM PDT THU JUL 11 2013
.SYNOPSIS...THE TRANQUIL WEATHER PATTERN WITH NEAR SEASONAL
TEMPERATURES WILL CONTINUE INTO NEXT WEEK. EXPECT MOSTLY CLEAR
SKIES ACROSS THE INTERIOR WHILE THE COAST SHOULD SEE OVERNIGHT
CLOUDS AND FOG WITH CLEARING EACH AFTERNOON.
&&
.DISCUSSION...CLOUDS AND FOG ALONG THE COAST SHOULD DISSIPATE THIS
MORNING AND AFTERNOON. OTHERWISE, THE CURRENT WEATHER PATTERN
SHOULD PERSIST INTO NEXT WEEK WITH ONLY MINIMAL CHANGES. THE COAST
CAN EXPECT MINOR FLUCTUATIONS TO THE CLOUDS AND FOG EACH DAY AND
NIGHT WHILE THE INTERIOR CAN EXPECT MINOR FLUCTUATIONS IN
AFTERNOON HIGH TEMPERATURES. A WEAK TROUGH CURRENTLY PASSING OVER
THE WEST COAST WILL BRING SLIGHTLY COOLER HIGH TEMPERATURES ACROSS
THE INTERIOR TODAY AND FRIDAY. THERE WERE NO THUNDERSTORMS WITH
THIS SYSTEM ACROSS OUR AREA YESTERDAY OR OVERNIGHT. AS THE TROUGH
MOVES INLAND TODAY THE ATMOSPHERE WILL FURTHER STABILIZE AND
MOISTURE SHOULD DECREASE. THEREFORE, REMOVED ALL THUNDERSTORMS
FROM THE FORECAST TODAY. THE TRINITY ALPS AND SURROUNDING HIGHER
TERRAIN CAN EXPECT SOME CUMULUS CLOUDS THIS AFTERNOON AT BEST.
OTHERWISE, WINDS WILL CONTINUE TO BE LIGHT AND TERRAIN DRIVEN
DURING THE DAY AND THEN VERY LIGHT AND OFFSHORE ACROSS THE
INTERIOR AT NIGHT. EXPECT A WARMING TREND WITH HOTTER TEMPERATURES
AND DRIER CONDITIONS THIS WEEKEND INTO NEXT WEEK.
&&
.AVIATION...NARROW STRIP OF LOW CLOUDS AND SOME MOSTLY LIGHT FOG
CONTINUES ALONG THE REDWOOD COAST. SAT PRODUCTS DO NOT SHOW MUCH
CHANGE IN CHARACTER OR COVERAGE OF CLOUDS DURING THE PAST FEW
HOURS. EXPECT CLOUDS TO ONCE AGAIN ERODE FROM THE E AS DAYTIME
HEATING COMMENCES. HRRR MODEL SHOWS LIGHT REVERSED S-SW FLOW ALONG
THE COAST N OF CAPE MENDO THRU MUCH OF THE DAY. THIS MAY SLOW THE
PROGRESSION OF CLOUDS BACK INLAND LATER TODAY. AT KUKI...SOME LOW
CLOUDINESS NOTED WELL S OF THE AIRPORT WITH LIGHT S WINDS AT KSTS.
WILL INCLUDE SCT LOW LAYER OF CLOUDINESS IN TAF UPDATE FOR THE
EARLY MORNING HOURS BUT NOT EXPECTED A CIG. /SEC
&&
.MARINE...FORECAST THINKING REMAINS BASICALLY UNCHANGED. STILL
APPEARS THAT WIND GUSTS WILL REMAIN BELOW GALE WARNING CRITERIA...
PERHAPS A BIT LOWER THAN PREVIOUSLY FORECAST. MARGINAL HAZARDOUS
SEAS WARNING WILL CONTINUE IN THE OFFSHORE WATERS THRU MIDNIGHT
TONIGHT. SEAS WILL CONTINUE TO BE DOMINATED BY SHORT PERIOD N WIND
DRIVEN WAVES PRODUCED BY INTERACTION OF OFFSHORE HIGH PRESSURE AND
INLAND THERMAL TROF. GRADIENT MAY RELAX A BIT EARLY NEXT WEEK...
BUT N FLOW WILL CONTINUE WITH PERIODIC WIND REVERSALS NEAR THE
COASTLINE. /SEC
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...NONE.
NORTHWEST CALIFORNIA COASTAL WATERS...
HAZARDOUS SEAS WARNING FOR PZZ470-475.
SMALL CRAFT ADVISORY FOR PZZ450-470-475.
&&
$$
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HTTP://WWW.TWITTER.COM/NWSEUREKA
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1119 AM EDT THU JUL 11 2013
.SYNOPSIS...
A COLD FRONT SLOWLY MOVES INTO FAR WESTERN PORTIONS OF THE TRI-
STATE THIS AFTERNOON AND GRADUALLY SLIDES OFFSHORE LATE
TONIGHT...BEFORE STALLING OUT TO THE SOUTH OF LONG ISLAND FRIDAY.
THE WEAK FRONTAL BOUNDARY WILL DISSIPATE OVER THE AREA FRIDAY
NIGHT INTO SATURDAY. HIGH PRESSURE GRADUALLY BUILDS INTO THE
REGION FOR THE REMAINDER OF THE WEEKEND AND INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AT 14Z A VERY POSITIVELY TILTED UPPER TROUGH STRETCHED FROM NE TO
SW ACROSS THE GREAT LAKES...WITH AN ASSOCIATED SURFACE COLD FRONT
STRETCHED FROM N VT INTO SW PA. LATEST WATER VAPOR IMAGERY/RADAR
IMAGERY AND LATEST MESOSCALE MODELS SUGGEST THAT AFTER CURRENT
SCT-NUMEROUS SHRA WITH EMBEDDED TSTMS LATE THIS MORNING...WILL
SEE AT MOST SCT CONVECTION THIS AFTERNOON...EXCEPT FOR MAYBE
ACROSS FAR S/E ZONES LATE. HAVE ADJUSTED POPS ACCORDINGLY. ALSO
GIVEN EXTENSIVE CLOUD COVER AND INITIAL SHRA THIS MORNING WORKING
THE LOWER LEVELS OVER /NOTE CAPES CURRENTLY 500-1000 J/KG WHILE
PREVIOUS DAYS ALREADY 1500-2500/...THAT AND NOTING MINIMAL
LIGHTNING UPSTREAM...HAVE REDUCED CHANCE OF THUNDER TO SCT. WILL
CONTINUE TO ASSESS AND MIGHT END UP REDUCING TO ISOLD WITH NEXT
UPDATE IF CURRENT TRENDS HOLD.
THAT SAID...LATEST RAP FORECAST 0-6KM SHEAR 25-40KT THIS AFTERNOON
WITH BRN 35-80...SO COULD SEE SOME ISOLATED LOW TOPPED SUPER CELLS
AND BOWING SEGMENTS...BUT STILL MAINLY PULSE STORMS LIKELY.
REFER TO THE HYDROLOGY SECTION FOR DETAILS ON EXPECTED
RAINFALL/IMPACTS.
FOR NOW TEMPERATURES FORECAST APPEARS ONT RACK...THOUGH IF CLOUD
COVER CONTINUES TO HOLD...MIGHT END UP LOWERING WITH NEXT UPDATE.
THERE IS A MODERATE RIP CURRENT RISK AT THE OCEAN BEACHES TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT THROUGH FRIDAY THE UPPER TROUGH AMPLIFIES WITH AN UPPER LOW
CLOSING OFF AND BECOMING CUTOFF WEST OF THE FORECAST AREA...OVER
PENNSYLVANIA...BY LATE FRIDAY. THE UPPER TROUGH BECOMES BLOCKED LATE
TONIGHT INTO FRIDAY AS THE NORTHERN ATLANTIC RIDGE BUILDS BACK TO
THE WEST. MEANWHILE AT THE SURFACE THE COLD FRONT MOVES INTO THE
REGION BY THIS AFTERNOON AND THEN MOVES VERY SLOWLY EAST THROUGH
TONIGHT AND STALLS SOUTH AND EAST OF THE REGION FRIDAY. GENERAL
AGREEMENT AMONG THE MODELS WITH THE GFS KEEPING THE FRONT AND UPPER
TROUGH A LITTLE FARTHER WEST THAN THE NAM AND ECMWF WITH THE
ATLANTIC TROUGH A LITTLE STRONGER.
THE CHANCE CONTINUES FOR SHOWERS AND THUNDERSTORMS TONIGHT INTO
FRIDAY. WITH INSTABILITY DECREASING TONIGHT SHOWERS WILL BE
POSSIBLE WITH ISOLATED THUNDER.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
MAIN PREDICTABILITY ISSUE DURING THIS PERIOD CONTINUE TO BE THE
EVOLUTION OF AN ELONGATED UPPER TROUGH ALONG THE EAST COAST TO START
THE PERIOD. ENSEMBLE AND OPERATIONAL GUIDANCE CONTINUE TO ADVERTISE
A TRANSITION OF THE TROUGH INTO A CUTOFF UPPER LOW OVER THE NORTHEAST
ON FRIDAY. 00Z OPERATIONAL GUIDANCE AND 00Z SREF AND GEFS HAVE
TRENDED TOWARDS THE UPPER LOW THEN RETROGRADING WESTWARD AS STRONG
ATLANTIC RIDGING TAKES OVER THIS WEEKEND INTO THE NEW WEEK.
IN TERMS OF SENSIBLE WEATHER...LINGERING SHOWER ACTIVITY SHOULD
GRADUALLY TAPER OFF FRIDAY NIGHT INTO SAT MORNING AS THE UPPER LOW
RETROGRADES WEST AND WEAK SURFACE FRONT DISSIPATES. WIDELY SCATTERED
SHOWERS POSSIBLE...MAINLY ACROSS INTERIOR SAT AFTERNOON WITH DIURNAL
HEATING. INSTABILITY AND FORCING LOOKS TO BE WEAK DURING THIS
TIME...SO THE THREAT FOR THUNDERSTORMS LOOKS TO BE ISOLATED AT BEST.
A CONDUCIVE HEAVY RAIN ENVIRONMENT WILL STILL MAINTAIN A THREAT FOR
HEAVY DOWNPOURS AND LOCALIZED URBAN POOR DRAINAGE FLOODING FRI NIGHT
INTO SAT.
THEREAFTER...WITH INDICATIONS THAT RIDGING WILL EVENTUALLY EXERT A
GREATER INFLUENCE SUNDAY THROUGH EARLY NEXT WEEK...POTENTIAL EXISTS
FOR A BUILDING HEATWAVE. IF 00Z OPERATIONAL GFS/GEM/ECMWF
VERIFY...FORECAST TEMPS COULD BE CONSERVATIVE...WITH POTENTIAL FOR
EXTENDED PERIOD OF HEAT ADVISORY CONDITIONS FOR NEXT WEEK. STAY
TUNED. OTHERWISE...MAINLY DRY CONDITIONS WITH ISOLATED DIURNAL
CONVECTION DEVELOPMENT POSSIBLE OFF OF SEABREEZE BOUNDARIES AND
HIGHER TERRAIN.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A COLD FRONT APPROACHES AND MOVES THROUGH THE REGION
TODAY...PRODUCING VARYING CONDITIONS. GENERALLY VFR WITH PERIODS OF
MVFR WITH ANY PCPN.
SCT -SHRA LATE THIS MORNING SHOULD PUSH THROUGH BY 18Z. PSBL TSRA
THIS AFTN...THOUGH CONFIDENCE REMAINS MODERATE ON THE COVERAGE AND
TIMING. WILL CONTINUE AS TEMPO GROUP FOR NOW. LINGERING SHOWERS THIS
EVENING...BUT WILL NOT INCLUDE AT THIS TIME WITH LOW CONFIDENCE OF
TIMING/COVERAGE.
BKN CLOUD COVER WITH GENERALLY VFR CIGS. ANY PCPN COULD BRING CIGS
DOWN TO MVFR. VIS SHOULD REMAIN 5SM OR GREATER...THOUGH ANY HEAVY
PCPN MAY REDUCE VIS BRIEFLY.
WINDS MAINLY AROUND 10 KTS THROUGH THE DAY...THOUGH VARYING IN
DIRECTION WITH A WEAK TROUGH SETTING UP AHEAD OF THE FRONT. LOW TO
MOD CONFIDENCE ON WIND DIRECTION THROUGH THE AFTN...WITH GROWING
CONFIDENCE THIS EVENING AND OVERNIGHT.
...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: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 18Z. WINDS WILL VARY BETWEEN 290 AND 330 THROUGH 21Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 18Z. LOW-MOD CONFIDENCE WINDS...VARYING BETWEEN 240 AND 280
THROUGH THE AFTN.
KLGA FCSTER COMMENTS: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 18Z. MOD CONFIDENCE WINDS REMAINING RIGHT OF 300 THROUGH
18Z...LOW CONFIDENCE AFTN WITH WINDS VARYING BETWEEN 270 AND 320.
KTEB FCSTER COMMENTS: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 18Z. WINDS WILL VARY BETWEEN 290 AND 330 THROUGH 21Z.
KHPN FCSTER COMMENTS: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 18Z. MOD CONFIDENCE WINDS REMAIN NW.
KISP FCSTER COMMENTS: PERIODIC PCPN THROUGH THE AFTN...ISO TSTM PSBL
AFTER 19. MOD CONFIDENCE WINDS REMAIN SW.
.OUTLOOK FOR 15Z FRIDAY THROUGH MONDAY...
.FRIDAY-FRIDAY NIGHT...SUB-VFR WITH PSBL SHRA AND TSTM DURING THE DAY
AND OVERNIGHT.
.SATURDAY-MONDAY...SUB-VFR POSSIBLE IN SHOWERS AND TSTMS ESP. N/W
OF NYC.
&&
.MARINE...
A SOUTHWESTERLY FLOW OF AROUND 15 KT LATE THIS MORNING WILL KEEP
SEAS ON THE OUTER OCEAN ZONES EAST OF FIRE ISLAND INLET AROUND 5
FEET...SO HAVE CONTINUED HAZARDOUS SEAS SMALL CRAFT ADVISORY
THROUGH NOON. MIGHT NEED TO AN EXTEND A FEW HOURS. WILL CONTINUE
TO MONITOR.
SOUTHERLY WIND IS EXPECTED TO DIMINISH AND SEAS SHOULD SUBSIDE
BELOW 5 FEET THIS AFTERNOON...WINDS AND SEAS ARE THEN EXPECTED TO
REMAIN BELOW SMALL CRAFT LEVELS THROUGH FRIDAY.
THERE WILL BE MAINLY SCT-LIKELY SHRA WITH ISOLD-SCT TSTMS THROUGH
FRIDAY AS WELL.
A WEAK FRONTAL SYSTEM WILL LIKELY DISSIPATE ACROSS THE REGION FRIDAY
NIGHT INTO EARLY SATURDAY. THERE IS POTENTIAL FOR MARGINAL SCA SEAS
DURING THIS TIME...PRIMARILY DUE TO LINGERING SOUTHERLY SWELLS.
OTHERWISE...SUB SCA CONDITIONS ARE EXPECTED FOR THE REMAINDER OF THE
WEEKEND INTO EARLY NEXT WEEK AS HIGH PRESSURE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
SCATTERED TO NUMEROUS SHOWERS WITH ISOLD-SCT THUNDERSTORMS WILL
BE CAPABLE OF PRODUCING LOCALLY HEAVY RAINFALL THROUGH FRIDAY
ACROSS THE HYDROLOGIC SERVICE AREA. ALTHOUGH WIDESPREAD FLOODING
IS NOT EXPECTED AT THIS TIME...POOR DRAINAGE AND NUISANCE IS
POSSIBLE...AND LOCALIZED FLASH FLOODING IS ALSO POSSIBLE WITH ANY
TRAINING CONVECTION. GIVEN FORECAST STORM MOTION OF 15-20 KT AND
LOW-MID LEVEL FLOW NOT PARALLEL WITH FRONT...PROBABILITY OF
TRAINING/FLASH FLOODING IS LOW.
BASIN AVERAGE RAINFALL TODAY THROUGH FRIDAY NIGHT WILL BE ONE TO ONE
AND A QUARTER INCHES.
NO WIDESPREAD HEAVY RAINFALL IS EXPECTED FRIDAY NIGHT INTO EARLY
NEXT WEEK.
LOCAL HEAVY DOWNPOURS ARE POSSIBLE FRIDAY NIGHT INTO SATURDAY
MORNING ALONG A DISSIPATING FRONTAL BOUNDARY. THIS WILL POSE A
LOCALIZED URBAN AND POOR DRAINAGE FLOODING THREAT.
THEREAFTER...ISOLATED SLOW MOVING DIURNAL THUNDERSTORM ACTIVITY SUN
THROUGH WED WILL POSE A LOCALIZED URBAN AND POOR DRAINAGE FLOOD
THREAT.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL NOON EDT TODAY
FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT/MET/NV
NEAR TERM...MALOIT/MET
SHORT TERM...MET
LONG TERM...NV
AVIATION...SEARS/DS
MARINE...MALOIT/MET/NV
HYDROLOGY...MALOIT/MET/NV
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1245 AM EDT THU JUL 11 2013
.SYNOPSIS...
A LOW PRESSURE SYSTEM WILL CROSS INTO EASTERN CANADA AND DRAG A COLD
FRONT INTO THE REGION LATE TONIGHT. THE COLD FRONT WILL MOVE SLOWLY
THROUGH THE AREA ON THURSDAY BEFORE STALLING JUST TO THE SOUTH AND
EAST OF THE REGION ON FRIDAY AND THEN DISSIPATE OVER THE WEEKEND.
HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND AND THEN
BECOME ABSORBED INTO THE RETROGRADING BERMUDA HIGH PRESSURE OVER THE
WESTERN ATLANTIC EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
WITH THE EARLY MORNING UPDATE, WE INCREASED POPS A BIT AND ADDED
THUNDER FOR THE NEXT FEW HOURS IN OUR FAR SOUTHERN DELMARVA ZONES
AS LATEST RADAR IMAGERY SHOWS CONTINUED SHOWER ACTIVITY WITH SOME
EMBEDDED THUNDER EDGING CLOSER TO THE AREA FROM THE SOUTHWEST.
THIS ACTIVITY IS ALSO REFLECTED IN THE HRRR AND SHOULD CONTINUE TO
GRADUALLY DISSIPATE BY AROUND 06Z OR 07Z. ELSEWHERE, SOME
CONVECTIVE ACTIVITY PASSING OVER OUR FAR NORTHWEST ZONES INTO THE
POCONOS HAS SINCE DISSIPATED, AND WE LOWERED POPS ACCORDINGLY.
OVERALL, WE KEPT LOW CHANCE POPS FOR SCATTERED SHWRS THROUGH THE
REMAINDER OF THE OVERNIGHT ACROSS THE FORECAST AREA AS A MID LEVEL
SHORTWAVE APPROACHES, GRADUALLY INCREASING THE POPS AFTER
DAYBREAK, AS MOST MODEL GUIDANCE SHOWS THE SHORTWAVE AND SOME
CHANNELIZED VORTICITY ARRIVING INTO THE REGION BY THEN.
IT WILL REMAIN HUMID TONIGHT. A LIGHT SOUTHWEST SURFACE FLOW IS
ANTICIPATED AND MINIMUM TEMPERATURES SHOULD RANGE FROM THE UPPER 60S
IN THE FAR NORTH TO THE LOWER AND MIDDLE 70S ELSEWHERE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
A MID LEVEL IMPULSE IS FORECAST TO PASS OVERHEAD ON THURSDAY
MORNING. A FRONTAL BOUNDARY IS EXPECTED TO APPROACH SLOWLY FROM
THE WEST THROUGH THE DAY. THE COMBINATION OF THE TWO FEATURES WILL
BRING A BETTER CHANCE FOR PRECIPITATION ON THURSDAY THAN WE
EXPERIENCED TODAY. PRECIPITABLE WATER VALUES SHOULD REMAIN MOSTLY
IN THE 1.5 TO 2.0 INCH RANGE SO LOCALLY MODERATE TO HEAVY RAINFALL
IS POSSIBLE.
THE SOUTHWEST SURFACE FLOW IS FORECAST TO CONTINUE FOR MOST OF THE
DAY AND TEMPERATURES SHOULD RISE INTO THE 80S AT MOST LOCATIONS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A SURFACE LOW PRESSURE SYSTEM MOVING THROUGH EASTERN CANADA WILL
CONTINUE TO SLOWLY PULL A COLD FRONT THROUGH OUR AREA THURSDAY
NIGHT. THE FRONT WILL THEN STALL JUST OFF TO OUR SOUTH AND EAST
AND DISSIPATE THROUGH THE WEEKEND. AN AREA OF HIGH PRESSURE WILL
MOVE INTO THE REGION BEHIND THE DEPARTING FRONT OVER THE WEEKEND.
THIS HIGH GETS SQUEEZED AROUND OUR AREA AND GETS ABSORBED INTO THE
BERMUDA HIGH PRESSURE SITTING OVER THE WESTERN ATLANTIC. THE
BERMUDA HIGH WILL RETROGRADE TOWARD THE EAST COAST THROUGH EARLY
NEXT WEEK. IN THE MID LEVELS, A WAVE FORMS ALONG THE STALLED
BOUNDARY AND MOVES THROUGH THE REGION THURSDAY NIGHT INTO FRIDAY.
A MID LEVEL TROUGH FOLLOWS BEHIND THIS WAVE AND ENTERS OUR AREA
FRIDAY NIGHT. THIS WAVE EVENTUALLY GETS CUT OFF FROM THE MID LEVEL
FLOW AND REMAINS CENTERED ACROSS NEW ENGLAND. SEVERAL IMPULSES
WILL ROTATE AROUND THIS CUT OFF MID LEVEL LOW AND MOVE THROUGH OUR
AREA THROUGH THE WEEKEND. THE CUT OFF LOW GRADUALLY PUSHES TO THE
SOUTHWEST EARLY NEXT WEEK.
SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH MUCH OF THE
EXTENDED PERIOD. SHOWERS AND THUNDERSTORMS WILL GRADUALLY MOVE OFF
TO THE SOUTH AND EAST AS THE FRONT PUSHES THROUGH AND THEN WE CAN
EXPECT TO DRY OUT A BIT EARLY ON FRIDAY. WITH THE LOW CUTTING OFF IN
THE MID LEVELS, WE ARE NOT ABLE TO SEE ANY KIND OF EXTENDED PERIOD
OF DRY WEATHER AND ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
WILL CONTINUE TO BE MENTIONED EVERY DAY.
TEMPERATURES WILL BE CLOSER TO NORMAL THROUGH THE PERIOD WITH HIGHS
IN THE 80S AND LOWS IN THE 60S TO LOWER 70S. ONE GOOD ITEM OF NOTE
IS SLIGHTLY LOWER DEW POINTS WHICH WILL HELP IT TO FEEL A BIT LESS
HUMID THAN IT HAS OF LATE. AS WE NEAR THE LATER PART OF THE
EXTENDED, TEMPERATURES WILL ONCE AGAIN REACH INTO THE LOWER 90S WITH
DEWPOINTS RISING. EXPECT IT TO BECOME PROGRESSIVELY MORE HUMID
TOWARD THE END OF THE PERIOD.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
VFR CONDITIONS WILL LIKELY CONTINUE INTO THE FIRST HALF OF THE
NIGHT. WHILE THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS IN OUR
REGION INTO THIS EVENING, IT APPEARS AS THOUGH MOST LOCATIONS WILL
REMAIN RAIN-FREE. THE BEST CHCS ARE FOR THE NWRN TAF SITES. THE
MOISTURE IN THE ATMOSPHERE MAY RESULT IN THE DEVELOPMENT OF MVFR
CEILINGS AND VISIBILITY VALUES FOR LATE TONIGHT. SHOWERS AND
SCATTERED THUNDERSTORMS ARE ANTICIPATED FOR THURSDAY AS A SLOW
MOVING FRONTAL BOUNDARY APPROACHES FROM THE WEST. CONDITIONS WILL
LIKELY BE VARIABLE ON THURSDAY. DECIDED TO PUT IN A PROB30 FOR
THUNDER THU AFTN WITH THE CDFNT COMING THRU.
THE WIND SHOULD REMAIN FROM THE WEST AND SOUTHWEST INTO THIS EVENING
WITH SPEEDS AROUND 10 KNOTS AND GUSTS NEAR 20 KNOTS. WIND SPEEDS
WILL LIKELY DROP INTO THE 4 TO 8 KNOT RANGE AFTER DARK WITH SOME
LOCATIONS BECOMING LIGHT AND VARIABLE. A SOUTHWEST WIND AT 10 KNOTS
OR LESS IS ANTICIPATED FOR THURSDAY. THE WIND WILL SHIFT MORE NWLY
BEHIND THE CFP.
OUTLOOK...
THURSDAY NIGHT...SHOWERS AND THUNDERSTORMS ARE EXPECTED TO AFFECT
THE TERMINALS AS A COLD FRONT MOVES THROUGH THE AREA. LOCAL MVFR OR
LOWER CONDITIONS WILL OCCUR IN ANY STORMS. SOME THUNDERSTORMS COULD
PRODUCE LOCALLY GUSTY WINDS.
FRIDAY...MAINLY VFR CONDITIONS EXPECTED. ISOLATED SHOWERS AND
THUNDERSTORMS POSSIBLE, MAINLY TO THE SOUTH AND EAST OF KPHL.
SATURDAY THROUGH MONDAY...MAINLY VFR CONDITIONS EXPECTED. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS ARE ANTICIPATED, ESPECIALLY
IN THE AFTERNOON AND EVENING. LOCAL MVFR OR LOWER CONDITIONS WILL
OCCUR IN ANY STORMS.
&&
.MARINE...
A SLOW MOVING FRONTAL BOUNDARY WILL APPROACH FROM THE WEST DURING
TONIGHT AND THURSDAY. WIND SPEEDS AND WAVE HEIGHTS WILL REMAIN BELOW
THE SMALL CRAFT ADVISORY CRITERIA. THERE IS A LOW CHANCE OF SHOWERS
AND THUNDERSTORMS INTO THIS EVENING. THERE IS A GREATER CHANCE FOR
SHOWERS AND THUNDERSTORMS ON THURSDAY.
OUTLOOK...
SUB-ADVISORY CONDITIONS ARE EXPECTED ON THE AREA WATERS THROUGH THE
PERIOD. A COLD FRONT WILL MOVE THROUGH THE AREA WATERS THURSDAY
AND THURSDAY NIGHT AND BRIEF TIGHTENING OF THE PRESSURE GRADIENT
WILL OCCUR. HOWEVER, WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW
SMALL CRAFT ADVISORY CRITERIA. THE GRADIENT THEN WEAKENS BEHIND
THE FRONT. THE FRONT STALLS TO THE SOUTH AND EAST OF THE AREA AND
WILL DISSIPATE OVER THE WEEKEND, KEEPING A RELATIVELY WEAK
GRADIENT ACROSS THE AREA WATERS THROUGH EARLY NEXT WEEK.
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO MOVE THROUGH THE REGION
OVER THE NEXT SEVERAL DAYS AND MAY CAUSE GUSTY WINDS TO OCCUR OVER
THE WATERS, WITH WINDS NEARING SPECIAL MARINE WARNING CRITERIA.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...IOVINO/KLINE/NIERENBERG
SHORT TERM...IOVINO
LONG TERM...MEOLA
AVIATION...IOVINO/NIERENBERG/MEOLA
MARINE...IOVINO/MEOLA
AREA FORECAST DISCUSSION
NWS MIAMI FL
926 PM EDT FRI JUL 12 2013
.UPDATE...
LATEST SURFACE ANALYSIS REVEALS COMPLEX PATTERN WITH TROPICAL WAVE
(FORMERLY CHANTAL) ACROSS WESTERN CARIBBEAN AND WESTERN CUBA WITH
SUBTLE PRESSURE TROUGH EXTENDING NORTH NORTHEAST FROM IT ACROSS
SOUTH FLORIDA. ANALYSIS ALSO REVEALS SURFACE TROUGH ACROSS THE
SOUTHEAST WITH OUTFLOW BOUNDARY ACROSS NORTHERN GULF STRETCHING
ACROSS THE CENTRAL FLORIDA PENINSULA BETWEEN AFOREMENTIONED
SURFACE TROUGH ACROSS THE SE AND THE TROPICAL WAVE TO THE SOUTH OF
THE AREA. AT THE UPPER LEVELS ANALYSIS REVEALS WEAK UPR LOW
ACROSS THE AREA RESULTING IN SOME UPR LEVEL DIVERGENCE BUT MOSTLY
TO OUR EAST. ALL THESE FEATURES RESULTED IN ACTIVE CONVECTIVE DAY
ACROSS THE AREA.
LATEST ENSEMBLE OF HIGH RESOLUTION MODELS INDICATE CONVECTION
ACROSS THE MAINLAND SHOULD CONTINUE TO DIMINISH OVER THE NEXT HOUR
OR SO AS LAND SURFACE DECOUPLES. THERE IS A BETTER CHANCE SOME
CONVECTIVE ACTIVITY PERSISTS OVERNIGHT ACROSS THE COASTAL WATERS
OF SW AND SE FL AS WELL AS COASTAL SE FLORIDA DUE TO THE PRESENCE
OF UPPER LEVEL LOW AND AFOREMENTIONED SURFACE TROUGH. ALL IN ALL
THE FORECAST IS ON TRACK REFLECTING THESE POSSIBILITIES. SO AT
THIS TIME UPDATED FORECAST DATABASE ONLY TO BETTER REFLECT CURRENT
TRENDS WITH NO MAJOR CHANGES ANTICIPATED OVERNIGHT.
FOR SATURDAY WEAK UPR LOW ACROSS THE AREA MOVES NORTH AND GETS
ABSORBED WITHIN BROADER UPPER LEVEL EAST COAST TROUGH DIGGING INTO
THE GULF OF MEXICO. THIS SHOULD PROVIDE A FAVORABLE DIVERGENT
UPPER LEVEL PATTERN ACROSS THE AREA WHICH COMBINED WITH REMNANTS
OF AFOREMENTIONED SURFACE TROUGH ACROSS THE AREA, SEA BREEZES, AND
OUTFLOW BOUNDARIES SHOULD RESULT IN A HIGH CHANCE OF SHOWERS AND
STORMS TOMORROW. ADDING TO THAT IS DEEPER MOISTURE MOVING IN FROM
THE EAST INTO THE WEEKEND.
MAIN CONCERN CONTINUES TO BE THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL AND FLOODING OF POOR DRAINAGE AREAS.
&&
.PREV DISCUSSION... /ISSUED 725 PM EDT FRI JUL 12 2013/
AVIATION...
SCATTERED CONVECTION WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH
THE EVENING HOURS. LATEST HRRR KEEPS THE ACTIVITY CONFINED ALONG
THE INTERIOR AND WEST AS IT WEAKENS OVERNIGHT. THEREFORE...NO VCTS
WAS MENTIONED AS PREVAILING IN TAFS EXCEPT FOR KPBI DUE TO THE
ACTIVITY ALREADY PRESENT. A MORE ACTIVE DAY IS EXPECTED
TOMORROW...WITH CONVECTION POSSIBLY STARTING AS EARLY AS 14-15Z.
BRIEF IFR CONDITIONS CAN BE EXPECTED WITHIN ANY TSRA. FLOW WILL
BECOME MORE SOUTHERLY...AND WITH THE MOISTURE AND INSTABILITY
ALREADY PRESENT ACROSS THE AREA...NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED.
PREV DISCUSSION... /ISSUED 239 PM EDT FRI JUL 12 2013/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THE LATEST WATER LOOP SHOWED AN UPPER LOW CENTERED JUST SOUTH OF THE
LOCAL AREA OVER THE KEYS WITH PLENTY OF MOISTURE SPREADING NORTH TO
ITS EAST OVER THE ADJACENT ATLANTIC WATERS AND BAHAMAS. THE
AFTERNOON SURFACE ANALYSIS SHOWED A TROUGH OF LOW PRESSURE JUST OFF
THE SE FLORIDA COAST ASSOCIATED WITH WHAT IS LEFT OF CHANTAL AND A
WEAK FRONTAL BOUNDARY EXTENDING WSW FROM SC TO MS. THIS SFC TROUGH
NEAR THE AREA COMBINED WITH THE UPPER LOW AND PLENTY OF DEEP LAYER
MOISTURE WILL CONTINUE TO INFLUENCE THE LOCAL WEATHER THROUGH
SATURDAY WITH SCATTERED/NUMEROUS SHOWERS/TSTMS DEVELOPING EACH
DAY.
THE LOCALLY RUN 1.5 KM WRF AND 13Z HRRR MODEL REFLECTIVITIES ARE IN
DECENT AGREEMENT WITH THE LATEST TRENDS THIS AFTERNOON AND CONTINUE
TO INDICATE THE LATE AFTERNOON ACTIVITY BECOMING MORE WIDESPREAD AND
FOCUSED ACROSS THE EASTERN HALF OF THE SRN FL PENINSULA WITH THE
SW LOW/MID-LEVEL FLOW IN PLACE. ONE OF THE MAIN CONCERNS THROUGH
THE REMAINDER OF THE DAY WILL BE THE POTENTIAL FOR LOCALIZED HEAVY
RAINFALL ACROSS THE EAST COAST AND METRO AREAS...WHICH COULD
QUICKLY RESULT IN URBAN FLOODING OVER THE TYPICALLY FLOOD PRONE
AREAS. ALTHOUGH THIS ACTIVITY IS FORECAST TO TREND DOWN THROUGH
THE LATE EVENING HOURS...THE PREVIOUSLY DISCUSSED SYNOPTIC
FEATURES COMBINED WITH A MID-LEVEL VORT MAX LIFTING NORTH ALONG
THE EAST COAST WILL BE ENOUGH TO KEEP THE RAIN CHANCES UP ACROSS
THE ADJACENT MARINE AREAS THROUGH THE OVERNIGHT HOURS...WHICH MAY
INFLUENCE THE IMMEDIATE COASTAL LOCATIONS.
THE PREVIOUSLY DISCUSSED UPPER LOW AND SURFACE TROUGH OFF THE EAST
COAST WILL BEGIN TO LIFT NORTH AND NORTHWEST OF THE LOCAL AREA LATER
TONIGHT THROUGH SATURDAY NIGHT. HOWEVER...THE LATEST NUMERICAL
GUIDANCE DEPICTS DEEP SOUTHERLY FLOW CONTINUING TO ADVECT MOISTURE
NORTHWARD OUT OF THE CARIBBEAN ACROSS THE FLORIDA PENINSULA THROUGH
THIS TIME. MODEL PWAT SOLUTIONS SHOW A PLUME OF 2-2.1" VALUES
STREAMING OVERHEAD...WHICH WILL SUPPORT WELL ABOVE NORMAL RAIN
CHANCES CONTINUING THROUGH THE DAY SATURDAY. THE MAIN IMPACTS AND
CONCERNS WILL BE LOCALIZED FLOODING WHERE ANY ACTIVITY BECOMES
FOCUSED OVER A PERIOD OF TIME. 85/AG
LONG TERM (SUNDAY-FRIDAY)...
THE WEATHER PATTERN SUNDAY AND BEYOND WILL FEATURE THE ATLANTIC
RIDGE BUILDING BACK IN. A TYPICAL SUMMERTIME PATTERN IS EXPECTED.
THERE IS ONE FEATURE OF NOTE - AN INVERTED TROUGH EAST OF OUR AREA
ALONG ABOUT 55 DEGREES WEST LONGITUDE. THIS FEATURE BROKE OFF FROM
THE MID LATITUDE WESTERLIES AND IS NOW TRAVELING WESTWARD. BOTH
GFS AND ECMWF TRACK THIS TROUGH ACROSS SOUTH FL ON MONDAY, RATHER
AMPLIFIED WITH NE WINDS AHEAD OF IT AND SE WINDS BEHIND IT.
THIS FEATURE COULD ENHANCE SHOWER AND THUNDERSTORM ACTIVITY AS
IT PASSES ON MONDAY.
57/GREGORIA
MARINE...
A WEAK TROUGH OF LOW PRESSURE AND AN UPPER LOW WILL CONTINUE TO
GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
MARINE AREAS INTO TONIGHT...ESPECIALLY OVER THE ATLANTIC WATERS.
ALTHOUGH WINDS AND SEAS WILL GENERALLY REMAIN LOW THROUGH THE
WEEKEND...CONDITIONS CAN QUICKLY CHANGE IN AND AROUND HEAVY SHOWERS
AND STORMS. LIGHT TO MODERATE EASTERLY WINDS AND SEAS WILL RETURN
SUNDAY AS THIS TROUGH OF LOW PRESSURE LIFTS NORTH OF THE AREA.
ANOTHER TROUGH IS FORECAST TO APPROACH THE FLORIDA PENINSULA THROUGH
THE DAY MONDAY AND MAY LEAD TO HIGHER RAIN CHANCES ONCE AGAIN.
FIRE WEATHER...
NO CONCERNS AS RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE
CRITICAL LEVELS EACH DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 89 76 89 / 40 70 40 50
FORT LAUDERDALE 74 87 77 89 / 40 70 40 50
MIAMI 75 88 76 89 / 40 70 40 50
NAPLES 74 89 75 88 / 40 70 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...52/PS
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
725 PM EDT FRI JUL 12 2013
.AVIATION...
SCATTERED CONVECTION WILL CONTINUE ACROSS SOUTH FLORIDA THROUGH
THE EVENING HOURS. LATEST HRRR KEEPS THE ACTIVITY CONFINED ALONG
THE INTERIOR AND WEST AS IT WEAKENS OVERNIGHT. THEREFORE...NO VCTS
WAS MENTIONED AS PREVAILING IN TAFS EXCEPT FOR KPBI DUE TO THE
ACTIVITY ALREADY PRESENT. A MORE ACTIVE DAY IS EXPECTED
TOMORROW...WITH CONVECTION POSSIBLY STARTING AS EARLY AS 14-15Z.
BRIEF IFR CONDITIONS CAN BE EXPECTED WITHIN ANY TSRA. FLOW WILL
BECOME MORE SOUTHERLY...AND WITH THE MOISTURE AND INSTABILITY
ALREADY PRESENT ACROSS THE AREA...NUMEROUS SHOWERS AND
THUNDERSTORMS ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 239 PM EDT FRI JUL 12 2013/
SHORT TERM (TONIGHT-SATURDAY NIGHT)...
THE LATEST WATER LOOP SHOWED AN UPPER LOW CENTERED JUST SOUTH OF THE
LOCAL AREA OVER THE KEYS WITH PLENTY OF MOISTURE SPREADING NORTH TO
ITS EAST OVER THE ADJACENT ATLANTIC WATERS AND BAHAMAS. THE
AFTERNOON SURFACE ANALYSIS SHOWED A TROUGH OF LOW PRESSURE JUST OFF
THE SE FLORIDA COAST ASSOCIATED WITH WHAT IS LEFT OF CHANTAL AND A
WEAK FRONTAL BOUNDARY EXTENDING WSW FROM SC TO MS. THIS SFC TROUGH
NEAR THE AREA COMBINED WITH THE UPPER LOW AND PLENTY OF DEEP LAYER
MOISTURE WILL CONTINUE TO INFLUENCE THE LOCAL WEATHER THROUGH
SATURDAY WITH SCATTERED/NUMEROUS SHOWERS/TSTMS DEVELOPING EACH
DAY.
THE LOCALLY RUN 1.5 KM WRF AND 13Z HRRR MODEL REFLECTIVITIES ARE IN
DECENT AGREEMENT WITH THE LATEST TRENDS THIS AFTERNOON AND CONTINUE
TO INDICATE THE LATE AFTERNOON ACTIVITY BECOMING MORE WIDESPREAD AND
FOCUSED ACROSS THE EASTERN HALF OF THE SRN FL PENINSULA WITH THE
SW LOW/MID-LEVEL FLOW IN PLACE. ONE OF THE MAIN CONCERNS THROUGH
THE REMAINDER OF THE DAY WILL BE THE POTENTIAL FOR LOCALIZED HEAVY
RAINFALL ACROSS THE EAST COAST AND METRO AREAS...WHICH COULD
QUICKLY RESULT IN URBAN FLOODING OVER THE TYPICALLY FLOOD PRONE
AREAS. ALTHOUGH THIS ACTIVITY IS FORECAST TO TREND DOWN THROUGH
THE LATE EVENING HOURS...THE PREVIOUSLY DISCUSSED SYNOPTIC
FEATURES COMBINED WITH A MID-LEVEL VORT MAX LIFTING NORTH ALONG
THE EAST COAST WILL BE ENOUGH TO KEEP THE RAIN CHANCES UP ACROSS
THE ADJACENT MARINE AREAS THROUGH THE OVERNIGHT HOURS...WHICH MAY
INFLUENCE THE IMMEDIATE COASTAL LOCATIONS.
THE PREVIOUSLY DISCUSSED UPPER LOW AND SURFACE TROUGH OFF THE EAST
COAST WILL BEGIN TO LIFT NORTH AND NORTHWEST OF THE LOCAL AREA LATER
TONIGHT THROUGH SATURDAY NIGHT. HOWEVER...THE LATEST NUMERICAL
GUIDANCE DEPICTS DEEP SOUTHERLY FLOW CONTINUING TO ADVECT MOISTURE
NORTHWARD OUT OF THE CARIBBEAN ACROSS THE FLORIDA PENINSULA THROUGH
THIS TIME. MODEL PWAT SOLUTIONS SHOW A PLUME OF 2-2.1" VALUES
STREAMING OVERHEAD...WHICH WILL SUPPORT WELL ABOVE NORMAL RAIN
CHANCES CONTINUING THROUGH THE DAY SATURDAY. THE MAIN IMPACTS AND
CONCERNS WILL BE LOCALIZED FLOODING WHERE ANY ACTIVITY BECOMES
FOCUSED OVER A PERIOD OF TIME. 85/AG
LONG TERM (SUNDAY-FRIDAY)...
THE WEATHER PATTERN SUNDAY AND BEYOND WILL FEATURE THE ATLANTIC
RIDGE BUILDING BACK IN. A TYPICAL SUMMERTIME PATTERN IS EXPECTED.
THERE IS ONE FEATURE OF NOTE - AN INVERTED TROUGH EAST OF OUR AREA
ALONG ABOUT 55 DEGREES WEST LONGITUDE. THIS FEATURE BROKE OFF FROM
THE MID LATITUDE WESTERLIES AND IS NOW TRAVELING WESTWARD. BOTH
GFS AND ECMWF TRACK THIS TROUGH ACROSS SOUTH FL ON MONDAY, RATHER
AMPLIFIED WITH NE WINDS AHEAD OF IT AND SE WINDS BEHIND IT.
THIS FEATURE COULD ENHANCE SHOWER AND THUNDERSTORM ACTIVITY AS
IT PASSES ON MONDAY.
57/GREGORIA
MARINE...
A WEAK TROUGH OF LOW PRESSURE AND AN UPPER LOW WILL CONTINUE TO
GENERATE SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
MARINE AREAS INTO TONIGHT...ESPECIALLY OVER THE ATLANTIC WATERS.
ALTHOUGH WINDS AND SEAS WILL GENERALLY REMAIN LOW THROUGH THE
WEEKEND...CONDITIONS CAN QUICKLY CHANGE IN AND AROUND HEAVY SHOWERS
AND STORMS. LIGHT TO MODERATE EASTERLY WINDS AND SEAS WILL RETURN
SUNDAY AS THIS TROUGH OF LOW PRESSURE LIFTS NORTH OF THE AREA.
ANOTHER TROUGH IS FORECAST TO APPROACH THE FLORIDA PENINSULA THROUGH
THE DAY MONDAY AND MAY LEAD TO HIGHER RAIN CHANCES ONCE AGAIN.
FIRE WEATHER...
NO CONCERNS AS RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE
CRITICAL LEVELS EACH DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 89 76 89 / 40 70 40 50
FORT LAUDERDALE 74 87 77 89 / 40 70 40 50
MIAMI 76 88 76 89 / 40 70 40 50
NAPLES 74 89 75 88 / 30 70 40 50
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...52/PS
AVIATION/RADAR...17/ERA
AREA FORECAST DISCUSSION
NWS MIAMI FL
245 PM EDT THU JUL 11 2013
.SHORT TERM (TONIGHT-SATURDAY NIGHT)...
RECENTLY ANIMATED WATER VAPOR LOOP SHOWED PLENTY OF MID/UPPER
MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL LOCATED OVER
EASTERN CUBA AND THE BAHAMAS EAST OF AN UPPER LOW CENTERED ACROSS
THE FLORIDA STRAITS. THE LATEST VISIBLE SATELLITE IMAGERY SHOWED
PLENTY OF CONVECTION CONTINUING TO FLARE BETWEEN JAMAICA AND EASTERN
CUBA EARLY THIS AFTERNOON NEAR A REMNANT TROUGH OF LOW PRESSURE. THE
12Z GFS RUN NOW INDICATES A WEAK SFC LOW DEVELOPING AND LIFTING
NORTH FROM THIS GENERAL AREA OVER THE GULF STREAM JUST EAST OF THE
FLORIDA PENINSULA TONIGHT THROUGH THE DAY FRIDAY WITH THE BULK OF
THE MOISTURE/RAINFALL PROJECTED TO REMAIN TO ITS EAST OVER THE
BAHAMAS. ALTHOUGH CONFIDENCE REMAINS LOW...REGENERATION IS CERTAINLY
NOT OUT OF QUESTION AND ALL INTERESTS ARE ENCOURAGED TO MONITOR THE
LATEST FORECAST AS UPDATES MAY BECOME NECESSARY OVER THE UPCOMING 24
HRS. REGARDLESS OF ANY FURTHER DEVELOPMENT...DAYTIME HEATING
COMBINED WITH THE DEEP LAYER FLOW SHIFTING TO THE WSW WILL FAVOR
CONVECTION INITIATING AND SETTING UP ACROSS THE EAST COAST METRO AND
COASTAL LOCATIONS THROUGH THE AFTERNOON/EVENING PERIODS...ESPECIALLY
ACROSS BROWARD AND PALM BEACH COUNTIES. ON SATURDAY...THE SFC LOW IS
FORECAST TO CONTINUE NORTH THEN NORTHWEST AND ASHORE SOMEWHERE ALONG
THE SC/GA COAST SATURDAY NIGHT. THE GFS PWAT SOLUTIONS INDICATE
VALUES INCREASING TO AROUND THE 2" MARK THROUGH THIS TIME SATURDAY
ACROSS SOUTH FLORIDA. THIS COMBINED WITH THE DEEP SOUTHWEST FLOW
WILL KEEP THE BEST RAIN CHANCES FOCUSED OVER THE EASTERN HALF OF THE
PENINSULA. ALTHOUGH A FEW STRONG STORMS WITH GUSTY WINDS UP TO 40-50
MPH WILL CERTAINLY REMAIN POSSIBLE EACH AFTERNOON...THE MAIN CONCERN
WILL BE THE POTENTIAL FOR LOCALIZED HEAVY RAIN AND URBAN FLOODING
OVER THE HEAVILY POPULATED EAST COAST/METRO AREAS EACH DAY.
.LONG TERM (SUNDAY-THURSDAY)...
THE ATLANTIC RIDGE WILL BEGIN TO BUILD IN NORTH OF THE AREA
SUNDAY, WITH STEERING FLOW TURNING MORE EASTERLY. AN EASTERLY
WIND FLOW IS THEN EXPECTED TO PREVAIL NEXT WEEK. BOTH GFS/ECMWF
SHOW AN INVERTED LOW-MID LEVEL TROUGH MOVING ACROSS FLORIDA DURING
THE EARLY-MIDDLE PART OF NEXT WEEK. THIS COULD ENHANCE SHOWER AND
THUNDERSTORM ACTIVITY SOMEWHAT, BUT FOR NOW FOLLOWED GFS MOS WITH
ONLY CHANCE POPS THROUGH THE LONG TERM PERIOD.
57/GREGORIA
&&
.AVIATION...
SCATTERED SHOWERS AND THUNDERSTORMS CONTINUE TO FIRE ACROSS MAINLY
THE INTERIOR THIS AFTERNOON FUELED BY SEA BREEZES FROM BOTH THE
ATLANTIC AND GULF. LATEST HRRR AND LOCAL HIGH RESOLUTION MODELS KEEP
THE VAST MAJORITY OF THE ACTIVITY ACROSS INLAND AREAS AND AWAY FROM
THE TAF SITES. DID KEEP VCSH IN AT ALL SITES THROUGH THE AFTERNOON
AND EARLY EVENING. COULD NOT RULE OUT AN ISOLATED TSRA AFFECTING A
TAF SITE BUT NOT CONFIDENT ENOUGH TO CARRY MENTION IN TAFS ATTM.
&&
.MARINE...
A SURFACE TROUGH OF LOW PRESSURE WILL LIFT NORTH OVER THE ATLANTIC
WATERS THROUGH THE DAY FRIDAY WITH LIGHT TO MODERATE SOUTH AND
SOUTHWEST FLOW FILLING IN ACROSS THE MARINE AREAS IN ITS WAKE FRIDAY
NIGHT INTO THE WEEKEND. SCATTERED SHOWERS AND STORMS ASSOCIATED WITH
THIS FEATURE...ESPECIALLY ALONG THE EAST COAST EACH AFTERNOON AND
EVENING...COULD LEAD TO PERIODS WITH REDUCED VISIBILITIES...GUSTY
WINDS AND LOCALLY CHOPPIER CONDITIONS IN AND AROUND THE HEAVIER
ACTIVITY.
&&
.FIRE WEATHER...
NO CONCERNS AS RELATIVE HUMIDITIES ARE FORECAST TO REMAIN ABOVE
CRITICAL LEVELS EACH DAY. THE FLOW WILL SHIFT TO THE SOUTHWEST
FRIDAY THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 89 75 88 / 20 60 30 60
FORT LAUDERDALE 77 89 78 89 / 20 60 30 60
MIAMI 77 89 77 88 / 20 60 30 60
NAPLES 73 87 74 89 / 20 30 30 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
LONG TERM...57/GREGORIA
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
959 AM EDT THU JUL 11 2013
.UPDATE...
NO MAJOR UPDATES ARE ANTICIPATED THIS MORNING AS THE PREVIOUS
FORECAST PACKAGE REMAINS ON TRACK. RECENTLY ANIMATED WATER VAPOR
LOOP SHOWED PLENTY OF MID/UPPER MOISTURE ASSOCIATED WITH THE
REMNANTS OF CHANTAL LIFTING NORTH OVER THE BAHAMAS EAST OF AN
UPPER LOW CENTERED ACROSS THE FLORIDA STRAITS. THE LATEST MODEL
GUIDANCE LINES UP WELL WITH THIS AND INDICATES THE BULK OF THIS
MOISTURE ASSOCIATED WITH CHANTAL REMAINING EAST OF SOUTH FLORIDA.
AS A RESULT...A MORE TYPICAL SUMMER-LIKE PATTERN IS ANTICIPATED
WITH MAINLY AFTERNOON SHOWERS AND THUNDERSTORMS EXPECTED TODAY.
THE LATEST HRRR AND WRF MODEL REFLECTIVITIES INDICATE ISOLATED TO
SCATTERED SHOWER/TSTM COVERAGE INITIATING AROUND 18Z AND SHIFTING
INLAND OF THE COASTAL AREAS AND CONTINUING THROUGH THE EARLY
EVENING HOURS BEFORE TRENDING DOWN.
&&
.PREV DISCUSSION... /ISSUED 740 AM EDT THU JUL 11 2013/
AVIATION...
IN ADVANCE OF THE REMNANTS OF TROPICAL STORM CHANTAL THERE IS
SOME DRIER AIR MOVING INTO THE REGION. BUT THERE WILL BE
SUFFICIENT MOISTURE FOR ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS THIS AFTERNOON, WITH MOST OF THE COVERAGE EXPECTED
TO THE WEST OF THE EAST COAST TERMINALS AND TO THE EAST OF
TERMINAL KAPF WITH VCSH ASSIGNED TO ALL TERMINALS. WITH THE
OCCURRENCE OF SHOWERS AND/OR THUNDERSTORMS, BRIEF PERIODS OF SUB-
VFR CONDITIONS ARE POSSIBLE.
PREV DISCUSSION... /ISSUED 415 AM EDT THU JUL 11 2013/
.REMNANTS OF CHANTAL TO PASS OFF TO OUR EAST WITH A TYPICAL
SUMMERTIME PATTERN EXPECTED THROUGH NEXT WEEK...
DISCUSSION...
HIGHLIGHTS...
* SCATTERED THUNDERSTORMS EACH DAY, EXCEPT NUMEROUS INTERIOR-
EAST COAST FRI-SAT AFTERNOON
* WIDESPREAD HEAVY RAINFALL NOT EXPECTED, BUT TYPICAL LOCALIZED
AMOUNTS OF 3"+ POSSIBLE EACH DAY IN THE HEAVIEST TSTORMS
SATELLITE IMAGERY SHOWS THAT THE BULK OF THE CONVECTION
ASSOCIATED WITH THE REMNANTS OF CHANTAL LIES NEAR THE SE BAHAMAS
AND IS MOVING N-NW. MODEL GUIDANCE INDEED SHOWS THAT THE VORT/BULK
OF THE MOISTURE ASSOCIATED WITH THIS REMNANT SYSTEM WILL PASS OUR
AREA TO THE EAST OVER THE BAHAMAS. MOS GUIDANCE POPS AND QPF ARE
NOT BULLISH...AND SREF PROBS OF HIGHER QPF ARE OVER THE BAHAMAS.
SO WE HAVE RATHER HIGH CONFIDENCE THIS MORNING THAT WIDESPREAD
HEAVY RAINS WILL NOT OCCUR. WPC INDEED LOWERED THEIR QPF TO AN
AREAL AVG OF AN INCH OR LESS FOR THE PERIOD TODAY-SAT. THAT BEING
SAID, IN TYPICAL SUMMERTIME FASHION, LOCALIZED HEAVY RAINFALL
AMOUNTS OF 3"+ WILL BE POSSIBLE EACH DAY IN THE HEAVIEST
THUNDERSTORMS THROUGH THE WEEKEND, SIMILAR TO WHAT HAS OCCURRED
OVER THE PAST COUPLE OF DAYS. LOCALIZED STREET FLOODING WILL BE
POSSIBLE WHERE THE HEAVY THUNDERSTORMS OCCUR.
SLIGHTLY DRIER AIR IS MOVING IN FROM THE SE TODAY WITH ONLY
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED, FOCUSED
OVER THE INTERIOR. MOISTURE WILL INCREASE FRI-SAT WITH PWATS NEAR
2 INCHES, WHICH IS HIGH BUT CERTAINLY NOT ATYPICAL FOR THIS TIME
OF THE YEAR. THE LOW TO MID LEVEL WIND FLOW WILL BECOME
SOUTHWESTERLY. THIS WILL FOCUS AFTERNOON THUNDERSTORMS ACROSS THE
INTERIOR AND EAST COAST METRO AREAS FRI-SAT AFTERNOON. WE EXPECT
THIS TO BE DIURNALLY DRIVEN WITH, AGAIN, THE REMNANTS OF CHANTAL
AND DEEPEST MOISTURE PASSING TO OUR EAST.
THE ATLANTIC RIDGE WILL BEGIN TO BUILD IN NORTH OF THE AREA
SUNDAY, WITH STEERING FLOW TURNING MORE EASTERLY. AN EASTERLY
WIND FLOW IS THEN EXPECTED TO PREVAIL NEXT WEEK. BOTH GFS/ECMWF
SHOW AN INVERTED LOW-MID LEVEL TROUGH MOVING ACROSS FLORIDA DURING
THE EARLY-MIDDLE PART OF NEXT WEEK. THIS COULD ENHANCE SHOWER AND
THUNDERSTORM ACTIVITY SOMEWHAT, BUT FOR NOW FOLLOWED GFS MOS WITH
ONLY CHANCE POPS THROUGH THE LONG TERM PERIOD.
MARINE...LIGHT WINDS AND LOW SEAS OF 3 FT OR LESS WILL PREVAIL
THROUGH THE PERIOD. A BRIEF INCREASE IN WINDS TO JUST AROUND 15 KT
IS FORECAST FOR THE OFFSHORE ATLANTIC WATERS LATE FRIDAY.
FIRE WEATHER...NO CONCERNS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 77 88 75 / 30 20 60 30
FORT LAUDERDALE 87 79 88 78 / 30 20 60 30
MIAMI 89 77 89 77 / 30 20 60 30
NAPLES 87 74 87 74 / 40 20 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
230 AM EDT THU Jul 11 2013
.NEAR TERM [Today]...
The 03 UTC regional surface analysis showed very weak pressure
pattern across the Southeast, which is common this time of year.
Much of the Southeast was under the influence of the western
periphery of the Atlantic subtropical ridge, interrupted with
several spot lows/highs and outflow boundaries. There was a large
MCS propagating southward across northern AL, but all of the latest
Convection Allowing Models (CAM), including the HRRR, forecast this
system to miss our forecast area just to our west later this
morning. Vapor imagery and upper air data showed a developing weak
trough over much of the eastern CONUS.
Today`s forecast is a bit tricky. The large scale pattern (the
upper level trough, daytime heating, and ample deep layer moisture)
suggests that rain is likely, which is what the MOS consensus shows.
However, the some of the 12 & 18 UTC CAM runs concentrate the rain
over fairly limited areas in FL, perhaps due to too much high clouds
and boundary layer turnover from the MCS currently tracking
southward. Our PoP forecast is a hedge between these different
possibilities, with a PoP in the 50 to 60% range across much of our
forecast area. The expected clouds and convection should keep high
temperatures a few degrees below climatology.
Although the large scale environmental wind field will be weak
today, there will be considerable boundary layer moisture which
could result in SBCAPE values exceeding 2500 J/KG this afternoon.
Given the upstream MCS development observed already, it`s not
unreasonable to anticipate at least some multi-cell organization
and/or a few pulse strong/severe storms over our forecast area. The
probability of a severe storm within 25 miles of a point is only 5%,
which is double that of climatology but still lower than the 15-30%
associated with a "Slight Risk".
&&
.SHORT TERM [Tonight through Saturday]...
An upper trough will deepen down the Atlantic seaboard with a low
closing off over the eastern Great Lakes by 12z Friday. The digging
trough will drive deep layer moisture and a surface cold front into
our CWA. Deep layer ridging off the northeast CONUS will build
westward into New England Saturday with the upper low retrograding
into the Ohio Valley. Locally the front is forecast to stall over
our CWA and a weak wave may develop on the boundary over or just
south of the panhandle on Saturday. Forecast PW`s through the period
are at or above 2". This will all lead to unsettled weather
conditions with above seasonal PoPs and the threat for heavy
rainfall on grounds that are at or near saturated from recent rains.
Max temps will be held just under climo with the increased cloud
cover and convection.
&&
.LONG TERM [Saturday night through Wednesday]...
Unsettled conditions will continue through a large portion of the
long term with near to above climo PoPs. The forecast pattern is
rather unusual with both the 10/00z ECMWF and 10/12z GFS showing
an upper level low retrograding southwestward from the northeast
states down to the Gulf coast. There are some detail differences
in the models, but both models signal an overall wet pattern
continuing. Near to slightly below average high temperatures are
forecast given the expected cloud cover.
&&
.AVIATION [Through 06 UTC Friday]...
The 00 UTC MOS consensus is strangely optimistic for this morning,
while the 02 UTC High Resolution Rapid Refresh (HRRR) run forecasts
widespread LIFR-VLIFR cigs until mid morning. Given that a few sites
were already showing SCT-BKN 400 ft cigs at 06 UTC, we went more
with the HRRR idea of low cigs. The cigs will lift to VFR late
morning or early afternoon, followed by scattered to numerous TSRA.
&&
.MARINE...
Winds and seas will be low as the marine area remains at the
western periphery of the subtropical Atlantic ridge. This portion of
the ridge will erode as a weakening cold front approaches and stalls
over or just north of the waters on Friday. A weak surface low may
development on the frontal boundary late Friday and move off to the
west or northwest over the weekend. If this low develops, winds and
seas will be a bit tricky to forecast but conditions should stay
below headline criteria.
&&
.FIRE WEATHER...
No fire weather concerns.
&&
.HYDROLOGY...
We appear to be headed into another stretch of wet weather over
the next 7-10 days based on the latest model guidance. Unlike the
round of heavy rainfall in early July, there is not much agreement
yet on a particular area where the heaviest rain totals may be
focused. Therefore, the outlook (in terms of hydrology) is just
for heavy rainfall and the possibility of some flooding issues
again. The 7-day WPC QPF calls for widespread 2-3 inch totals over
our entire area, which is very close to model ensemble mean
values. Of course, there are likely to be localized values well in
excess of that.
Even taking the 2-3 inch rain forecast literally (which is pretty
close to the majority of the NAEFS members) and applying it to
MMEFS forecasts for river points in our area does produce some
chance of flooding on a few of the rivers.
Rivers Most At-Risk For Continued / Developing Flooding July 10-20
------------------------------------------------------------------
Aucilla River, St. Marks River, Withlacoochee River near Valdosta,
the Choctawhatchee River (particularly lower portions), and the
Apalachicola River. Only change since this afternoon is that due
to heavy rains, Aucilla back to minor flooding.
Of course, given high flows on many rivers due
to recent rainfall, it would be impossible to totally rule out
rises and/or flooding on any of our area rivers. Where localized
heavy rainfall sets up will be the main concern - as it will have
the potential to produce flash flooding, as well as more
considerable rises on rivers. After several days of rain, the more
at-risk areas may be easier to pinpoint. The bottom line is that
those with interests along area rivers, streams, and creeks, and
in flood-prone areas should keep a close eye on forecasts over the
next 7-10 days.
&&
.PRELIMINARY POINT TEMPS/POPS...
TALLAHASSEE 88 72 90 72 89 / 60 50 70 50 60
PANAMA CITY 85 75 87 74 89 / 60 50 70 50 60
DOTHAN 88 72 90 72 89 / 50 50 60 30 60
ALBANY 89 72 90 72 90 / 50 50 70 40 60
VALDOSTA 89 71 89 70 88 / 50 50 70 50 60
CROSS CITY 89 71 89 71 90 / 60 40 70 60 60
APALACHICOLA 85 75 85 72 87 / 60 50 70 50 60
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
Near Term...Fournier
Short Term...Barry
Marine...Barry
Aviation/Fire Weather...Fournier
Long Term...DVD
Hydrology...Block/Lamers
AREA FORECAST DISCUSSION
NWS BOISE ID
955 AM MDT THU JUL 11 2013
.DISCUSSION...ENERGY BEING EJECTED FROM AN UPPER LEVEL TROUGH IS
GOING TO CONTINUE TO IMPACT OUR AREA TODAY. AS OF 930 AM MDT...A
LARGE AREA OF CLOUD COVER EXTENDED EAST OF A LINE FROM NEAR KREO
TO NEAR KMYL. WITHIN THIS AREA...SHOWERS WERE CONCENTRATED ALONG A
LINE FROM SW TWIN FALLS COUNTY THROUGH KTWF TO JUST EAST OF KJER.
OTHER SHOWERS WERE MOVING NORTHEAST TOWARD THE OWYHEES...BUT WE DO
NOT EXPECT MEASURABLE PRECIPITATION IN THE TREASURE VALLEY THIS
MORNING. WE HAVE INCREASED THE CHANCE OF SHOWERS ACROSS THE NW
PORTION OF THE CWA IN RESPONSE TO INCREASED CONFIDENCE IN A
CONVECTIVE EVENT THIS AFTERNOON AND EVENING. THE HRRR AND NAM SHOW
CONVECTION DEVELOPING MID-AFTERNOON AND EXTENDING INTO THE EVENING
GENERALLY FROM NEAR KBNO NE TO MOST OF BAKER COUNTY. THIS
CONVECTION IS ASSOCIATED WITH A STRONG JET STREAK...120 KTS NEAR
200 MB...THAT WILL ENHANCE THE DEVELOPMENT AND LONGEVITY OF THE
CELLS THAT FORM. WE EXPECT TO GET SOME WIND GUSTS TO 50 MPH...AND
POSSIBLY OVER 60 MPH. UPDATE WILL BE OUT SHORTLY.
&&
.AVIATION...VFR. BROKEN TO OVERCAST MID LEVEL CEILING WITH WIDELY
SCATTERED SHOWERS EAST OF A KREO-KONO-KMYL LINE THIS MORNING WILL
MOVE SLOWLY EAST TODAY. AFTER 21Z ISOLATED SHOWERS AND
THUNDERSTORMS WILL DEVELOP NORTH AND WEST OF A KBNO-KMYL LINE.
THESE THUNDERSTORMS WILL LAST THROUGH 06Z WITH THE MAIN THREAT OF
STRONG GUSTY WINDS. LIGHT SURFACE WINDS THIS MORNING BECOMING
SOUTHWEST TO WEST 10-15 KNOTS WITH GUSTY WINDS NEAR THUNDERSTORMS.
WINDS ALOFT WILL BE SOUTHWESTERLY AROUND 15 KNOTS UP THROUGH 10K
FEET MSL.
&&
.PREV DISCUSSION...
SHORT TERM...TODAY THROUGH FRIDAY...SOUTHWEST FLOW BROUGHT A SURGE
OF MOISTURE INTO SW IDAHO OVERNIGHT. HOWEVER...RADAR RETURNS ARE
WEAK AND THERE IS A LACK OF SUFFICIENT INSTABILITY TO SUPPORT
THUNDERSTORMS AT THIS TIME. FURTHER WEST...ISOLATED THUNDERSTORMS
HAVE BEEN OCCURRING JUST TO THE WEST AND NORTH OF OUR CWA...
STRETCHING ACROSS NORTHEAST OREGON INTO THE IDAHO PANHANDLE. THESE
STORMS WERE SUPPORTED BY AN 80-90 KNOT UPPER JET. THE LATEST MODEL
SOLUTIONS CONTINUE TO STREAM MOISTURE INTO SW IDAHO OUT OF NEVADA
THROUGH THIS AFTERNOON. HOWEVER...INSTABILITY WILL BE WEAK DUE TO
LACK OF HEATING AND A CAP AT AROUND 450 MB WHICH WILL LIMIT DEEP
CONVECTION. SO...WILL MAINTAIN ISOLATED VS SCATTERED THUNDERSTORM
COVERAGE THIS AFTERNOON. MEANWHILE...THE UPPER JET WILL GRADUALLY
SHIFT EAST ACROSS THE AREA TODAY WHICH WILL SUPPORT ISOLATED
THUNDERSTORMS FROM NORTHERN HARNEY/MALHEUR COUNTIES INTO BAKER
COUNTY. UPPER FLOW WILL SHIFT TO A MORE WESTERLY COMPONENT TONIGHT
AND FRIDAY...SHIFTING THE BULK OF THE MOISTURE TO THE EAST EXCEPT
SOUTH OF TWIN FALLS WHICH WILL BE ON THE EDGE OF THE MOISTURE.
TEMPERATURES WILL BE LOWER TODAY...ESPECIALLY EAST OF MOUNTAIN HOME
WHERE SKIES WILL REMAIN MOSTLY CLOUDY THROUGH THE AFTERNOON. SKIES
WILL BE MOSTLY CLEAR ON FRIDAY...RESULTING IN WARMER TEMPERATURES
EAST OF MOUNTAIN HOME BUT WITH LITTLE CHANGE ELSEWHERE. ONLY MADE
MINOR CHANGES TO THE FORECAST.
LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...WARM AND DRY WEATHER
THROUGH THE EXTENDED PERIOD AS SE OREGON AND SW IDAHO WILL BE
SITUATED BETWEEN AN OPEN WAVE TROUGH OVER BRITISH COLUMBIA AND AN
UPPER LEVEL HIGH PRESSURE SYSTEM CENTERED OVER THE FOUR-CORNERS
REGION. THIS PATTERN LOOKS TO PERSIST THROUGH THE END OF NEXT WEEK.
EXPECT TEMPERATURES TO BE NEAR NORMAL ON SATURDAY BEFORE WARMING UP
AS HEIGHTS GRADUALLY RISE OVER THE AREA...UP TO AROUND 10 DEGREES
ABOVE NORMAL FROM MONDAY ONWARDS.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...SP
AVIATION.....JA
PREV SHORT TERM...BW
PREV LONG TERM....CB
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1046 AM CDT THU JUL 11 2013
.DISCUSSION...
ISSUED 1046 AM CDT THU JUL 11 2013
NO MAJOR CHANGES TO THE FORECAST LATE THIS MORNING...JUST A FEW
TWEAKS TO HOURLY TEMPERATURES. THE LATEST SURFACE ANALYSIS
INDICATED HIGH PRESSURE CENTERED IN EXTREME NW IL...WITH A LIGHT
NORTHEAST FLOW ACROSS CENTRAL IL. DEW POINTS ARE STILL A BIT
HIGHER THAN SURROUNDING LOCATIONS BECAUSE OF PLENTY OF SOIL
MOISTURE. HOWEVER...WE SHOULD MIX UP THE LOWER ATMOSPHERE AND
BRING DRIER AIR DOWN THIS AFTERNOON AND ESPECIALLY OVERNIGHT AS
THE RIDGE AXIS MOVES OVER THE AREA.
THE 12Z ILX SOUNDING DID INDICATE A TRIGGER TEMP IN THE MIDDLE
70S...WHICH WE ARE AT RIGHT NOW. THUS...WE SHOULD SEE SOME
SCATTERED CUMULUS FORMING SOON.
MILLER
&&
.AVIATION...
ISSUED 607 AM CDT THU JUL 11 2013
HIGH PRESSURE OVER THE GREAT LAKES TO PROVIDE VFR CONDITIONS TO
CENTRAL ILLINOIS OVER THE NEXT 24 HOURS. SOME STRATOCUMULUS AROUND
5000 FEET HAS BEEN DRIFTING SOUTHWARD RECENTLY...AND HUMIDITY
CROSS SECTIONS FROM THE RAP MODEL SUGGEST SCATTERED TO
OCCASIONALLY BROKEN CLOUDS WILL CONTINUE INTO MID AFTERNOON...
BEFORE THEY ARE ERODED BY DRIER AIR ADVECTING SOUTHWEST FROM LAKE
MICHIGAN.. CLEAR SKIES ARE THEN EXPECTED OVERNIGHT. NORTHEAST
WINDS TODAY WILL GRADUALLY TURN EASTERLY TONIGHT AS THE HIGH SLIDES
FURTHER EAST.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 254 AM CDT THU JUL 11 2013
SHORT TERM...TODAY THROUGH SATURDAY
HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TODAY...PROVIDING
CENTRAL ILLINOIS WITH PLENTY OF SUNSHINE AND A DRY N/NE FLOW.
07Z/2AM SURFACE DEWPOINTS HAVE ALREADY DROPPED INTO THE LOWER TO
MIDDLE 60S AND THESE SHOULD MIX OUT INTO THE MIDDLE 50S AS THE DAY
PROGRESSES. IN ADDITION TO THE MUCH LOWER HUMIDITY VALUES
TODAY...AFTERNOON HIGH TEMPERATURES WILL ONLY REACH THE LOWER 80S.
ANY DIURNAL CLOUDINESS WILL QUICKLY DISSIPATE BY SUNSET...FOLLOWED
BY CLEAR SKIES OVERNIGHT. EXCELLENT RADIATIONAL COOLING OF THE DRY
AIR MASS WILL ALLOW LOW TEMPS TO DROP INTO THE MIDDLE TO UPPER 50S.
COOL/DRY WEATHER WILL PREVAIL THROUGH FRIDAY AS WELL...BEFORE
RISING UPPER HEIGHTS AND AIR MASS MODIFICATION PUSH HIGHS INTO THE
MIDDLE 80S BY SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY
MODELS ARE BEGINNING TO INTRODUCE A POTENTIAL WRINKLE IN THE
PREVIOUS DRY FORECAST IN THE EXTENDED. UPPER SHORT-WAVE CURRENTLY
DROPPING THROUGH THE GREAT LAKES IS EXPECTED TO AMPLIFY AND
EVENTUALLY CUT-OFF OVER THE MID-ATLANTIC STATES BY FRIDAY. WHAT
HAPPENS NEXT IS STILL VERY MUCH IN QUESTION...AS MOST MODELS NOW
RETROGRADE THE CLOSED LOW WESTWARD ACROSS CENTRAL ILLINOIS ON
SUNDAY...THEN FURTHER WEST INTO THE PLAINS EARLY NEXT WEEK. THIS
WOULD BE A VERY UNUSUAL OCCURRENCE IF THIS DOES INDEED OCCUR...SO
FORECAST CONFIDENCE IS LOW. WILL WAIT TO SEE IF THE WAVE CUTS OFF
AS ADVERTISED BEFORE BUYING INTO THE WESTWARD PROGRESSION OVER THE
WEEKEND. AT THIS POINT...WILL MAINTAIN A DRY FORECAST THROUGH THE
ENTIRE PERIOD WITH HIGH TEMPERATURES CLIMBING BACK INTO THE UPPER
80S TO AROUND 90 FOR SUNDAY THROUGH WEDNESDAY. IF MODELS ARE
CORRECT...CHANCE POPS MAY NEED TO BE ADDED FOR SUNDAY/MONDAY
BEFORE LOW SHIFTS FURTHER WEST INTO THE PLAINS. MAIN STORY EARLY
NEXT WEEK WILL BE THE RETURN OF THE VERY WARM/HUMID AIR MASS...AS
SOUTHERLY WINDS WILL HELP BOOST DEWPOINTS BACK INTO THE LOWER 70S
BY MONDAY.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
608 AM CDT THU JUL 11 2013
.DISCUSSION...
ISSUED 254 AM CDT THU JUL 11 2013
SHORT TERM...TODAY THROUGH SATURDAY
HIGH PRESSURE WILL BUILD INTO THE GREAT LAKES TODAY...PROVIDING
CENTRAL ILLINOIS WITH PLENTY OF SUNSHINE AND A DRY N/NE FLOW.
07Z/2AM SURFACE DEWPOINTS HAVE ALREADY DROPPED INTO THE LOWER TO
MIDDLE 60S AND THESE SHOULD MIX OUT INTO THE MIDDLE 50S AS THE DAY
PROGRESSES. IN ADDITION TO THE MUCH LOWER HUMIDITY VALUES
TODAY...AFTERNOON HIGH TEMPERATURES WILL ONLY REACH THE LOWER 80S.
ANY DIURNAL CLOUDINESS WILL QUICKLY DISSIPATE BY SUNSET...FOLLOWED
BY CLEAR SKIES OVERNIGHT. EXCELLENT RADIATIONAL COOLING OF THE DRY
AIR MASS WILL ALLOW LOW TEMPS TO DROP INTO THE MIDDLE TO UPPER 50S.
COOL/DRY WEATHER WILL PREVAIL THROUGH FRIDAY AS WELL...BEFORE
RISING UPPER HEIGHTS AND AIR MASS MODIFICATION PUSH HIGHS INTO THE
MIDDLE 80S BY SATURDAY.
LONG TERM...SUNDAY THROUGH WEDNESDAY
MODELS ARE BEGINNING TO INTRODUCE A POTENTIAL WRINKLE IN THE
PREVIOUS DRY FORECAST IN THE EXTENDED. UPPER SHORT-WAVE CURRENTLY
DROPPING THROUGH THE GREAT LAKES IS EXPECTED TO AMPLIFY AND
EVENTUALLY CUT-OFF OVER THE MID-ATLANTIC STATES BY FRIDAY. WHAT
HAPPENS NEXT IS STILL VERY MUCH IN QUESTION...AS MOST MODELS NOW
RETROGRADE THE CLOSED LOW WESTWARD ACROSS CENTRAL ILLINOIS ON
SUNDAY...THEN FURTHER WEST INTO THE PLAINS EARLY NEXT WEEK. THIS
WOULD BE A VERY UNUSUAL OCCURRENCE IF THIS DOES INDEED OCCUR...SO
FORECAST CONFIDENCE IS LOW. WILL WAIT TO SEE IF THE WAVE CUTS OFF
AS ADVERTISED BEFORE BUYING INTO THE WESTWARD PROGRESSION OVER THE
WEEKEND. AT THIS POINT...WILL MAINTAIN A DRY FORECAST THROUGH THE
ENTIRE PERIOD WITH HIGH TEMPERATURES CLIMBING BACK INTO THE UPPER
80S TO AROUND 90 FOR SUNDAY THROUGH WEDNESDAY. IF MODELS ARE
CORRECT...CHANCE POPS MAY NEED TO BE ADDED FOR SUNDAY/MONDAY
BEFORE LOW SHIFTS FURTHER WEST INTO THE PLAINS. MAIN STORY EARLY
NEXT WEEK WILL BE THE RETURN OF THE VERY WARM/HUMID AIR MASS...AS
SOUTHERLY WINDS WILL HELP BOOST DEWPOINTS BACK INTO THE LOWER 70S
BY MONDAY.
BARNES
&&
.AVIATION...
ISSUED 607 AM CDT THU JUL 11 2013
HIGH PRESSURE OVER THE GREAT LAKES TO PROVIDE VFR CONDITIONS TO
CENTRAL ILLINOIS OVER THE NEXT 24 HOURS. SOME STRATOCUMULUS AROUND
5000 FEET HAS BEEN DRIFTING SOUTHWARD RECENTLY...AND HUMIDITY
CROSS SECTIONS FROM THE RAP MODEL SUGGEST SCATTERED TO
OCCASIONALLY BROKEN CLOUDS WILL CONTINUE INTO MID AFTERNOON...
BEFORE THEY ARE ERODED BY DRIER AIR ADVECTING SOUTHWEST FROM LAKE
MICHIGAN.. CLEAR SKIES ARE THEN EXPECTED OVERNIGHT. NORTHEAST
WINDS TODAY WILL GRADUALLY TURN EASTERLY TONIGHT AS THE HIGH SLIDES
FURTHER EAST.
GEELHART
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1159 AM EDT THU JUL 11 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT THU JUL 11 2013
HIGH PRESSURE WILL BRING MOSTLY DRY WEATHER TO CENTRAL INDIANA
THROUGH SATURDAY NIGHT. THEN...AN UPPER LOW WILL MOVE WEST ACROSS
THE OHIO VALLEY WHICH COULD RESULT IN A FEW SHOWERS OR THUNDERSTORMS
LATE IN THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BE BELOW
NORMAL THURSDAY AND FRIDAY WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
TEMPERATURES SHOULD RETURN TO NEAR NORMAL LATE IN THE WEEKEND AND
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 955 AM EDT THU JUL 11 2013
OVERALL THE CURRENT FORECAST SEEMS TO BE ON TRACK. HIGH PRESSURE
ACROSS WISCONSIN AND IOWA WILL MOVE INTO THE LOWER GREAT LAKES BY
THIS EVENING. MADE SOME MINOR TWEAKS TO THE GRIDS MAINLY TO BACK
OFF ON SKY COVER A LITTLE MIDDAY OVER ALL BUT FAR EASTERN SECTIONS
PER RUC SOUNDINGS. LAV INDICATES TEMPERATURES MAY BE A TAD WARMER
SOME AREAS LATER TODAY. OTHERWISE...NO SIGNIFICANT CHANGES.
WILL UPDATE THE ZFP TO REFRESH WORDING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 218 AM EDT THU JUL 11 2013
MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUDS AND POSSIBILITY OF
SHOWERS SATURDAY AND SATURDAY NIGHT AS MODELS ARE NOW IN AGREEMENT
THAT AN UPPER LOW WILL BREAK FROM THE AFOREMENTIONED SHARP UPPER
TROUGH AND RETROGRADE WEST TOWARDS THE OHIO VALLEY UNDERCUTTING A
NORTHEASTWARD EXPANDING RIDGE OF HIGH PRESSURE. THE 00Z GFS AND 00Z
GEM IN AGREEMENT ON BRINGING THIS UPPER LOW ACROSS CENTRAL INDIANA
ON SATURDAY NIGHT...WHILE THE 00Z NAM AND 12Z ECMWF ARE SLOWER TO
BRING THIS FEATURE WEST...ONLY MOVING IT TO FAR EASTERN KENTUCKY OR
CENTRAL OHIO RESPECTIVELY BY 12Z SUNDAY. WITH POSITIONING AND TIMING
IN DOUBT...WILL LEAVE IT DRY FOR NOW THROUGH SATURDAY NIGHT BUT WITH
SOME INCREASE IN CLOUD COVER SATURDAY NIGHT. OTHERWISE...SHOULD ONLY
SEE SCATTERED DIURNAL CU WITH CLEAR NIGHTTIME SKIES AS BROAD SURFACE
HIGH PRESSURE GENERAL SETTLES ACROSS SOUTHERN ONTARIO AND QUEBEC
LATE IN THE SHORT TERM.
850 MILLIBAR TEMPERATURES WARM SLIGHTLY TO 14 TO 15 DEGREES CELSIUS
BY FRIDAY AS THE HIGH SHIFTS EAST OF THE AREA. PREFER THE SLIGHTLY
COOLER 00Z NAM MOS...WHICH IS CLOSE TO ALLBLEND...BASED ON THE 850
MILLIBAR PROGS. MEANWHILE...MOS THURSDAY AND FRIDAY NIGHTTIME
TEMPERATURES CLOSE AND APPEAR REASONABLE. WITH LIGHT NORTHEAST TO
CALM WINDS...EXPECT THE USUAL RURAL AND LOW LYING AREAS TO BE
SEVERAL DEGREES COOLER AT DAWN. WILL GO WITH A MODIFIED
ALLBLEND...AND MANUALLY LOWER THOSE AREAS A COUPLE OF DEGREES.
TEMPERATURES IN RURAL AREAS COULD FALL AS LOW AS THE MID 50S.
WITH A BIT MORE CLOUD COVER...TEMPERATURES WILL NOT BE AS COOL
SATURDAY NIGHT WITH OVERNIGHT LOWS IN THE LOWER TO MID 60S EXPECTED.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 259 AM EDT THU JUL 11 2013
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE AN UPPER
LEVEL LOW THAT ORIGINATES OVER THE NORTHEAST U.S. AND RETROGRADES
BACK INTO THE OHIO VALLEY AND CENTRAL U.S. LATEST INITIALIZATION
HAS COMPLETELY SWITCHED FROM A DRY FORECAST IN THE EXTENDED AS
ORIGINALLY FORECASTED THE LAST FEW NIGHTS...TO NOW BRINGING PRECIP
INTO CENTRAL INDIANA FOR THE MAJORITY OF EXTENDED PERIOD IN
ASSOCIATION WITH THAT UPPER LOW. FOR NOW...DECIDED TO GO WITH
SLIGHT CHANCE POPS OVER MOST OF THE PERIOD SINCE MODELS DO TAKE
THAT LOW MORE DIRECTLY OVER CENTRAL INDIANA NOW AS OPPOSED TO THE
TENNESSEE VALLEY INDICATED IN EARLIER RUNS. HOWEVER...WOULD NOT
PUT HIGH CONFIDENCE IN THIS FORECAST DUE TO THE DRASTIC SWITCH IN
MODELS FROM RUN TO RUN. A WARM MOIST ENVIRONMENT WILL BE IN PLACE
DAILY TO CONTRIBUTE TO DESTABILIZATION AND DIURNAL THUNDERSTORMS.
HIGH TEMPS WILL BE IN THE UPPER 80S WITH DEWPOINTS IN THE UPPER
60S/LOW 70S.
&&
.AVIATION /DISCUSSION FOR THE 111800Z TAF ISSUANCE/...
ISSUED AT 1155 AM EDT THU JUL 11 2013
VFR CONDITIONS ARE GENERALLY EXPECTED FOR ENTIRE TAF PERIOD (WITH
ONE OR TWO MINOR EXCEPTIONS FRI MORNING) AS HIGH PRESSURE AND DRIER
AIR FILTER INTO CENTRAL INDIANA. DIURNAL CU HAS ALREADY BEGUN TO
DEVELOP OVER SOME OF THE AREA AROUND 030-050...BUT NOTHING THAT
WILL IMPACT OPERATIONS. WINDS WILL BE NORTHEASTERLY AT 6 TO 12
KTS...DECREASING TO AROUND 5 KT OR LESS AFTER 02Z. CLEAR SKIES
OVERNIGHT WITH SOME PATCHY MFVR BR POSSIBLE AT KBMG AFTER 09Z AND
MORNING HZ AT KIND REDUCING THE VIS TO 6SM.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...JH
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...SMF
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1014 AM EDT THU JUL 11 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT THU JUL 11 2013
HIGH PRESSURE WILL BRING MOSTLY DRY WEATHER TO CENTRAL INDIANA
THROUGH SATURDAY NIGHT. THEN...AN UPPER LOW WILL MOVE WEST ACROSS
THE OHIO VALLEY WHICH COULD RESULT IN A FEW SHOWERS OR THUNDERSTORMS
LATE IN THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BE BELOW
NORMAL THURSDAY AND FRIDAY WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
TEMPERATURES SHOULD RETURN TO NEAR NORMAL LATE IN THE WEEKEND AND
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 955 AM EDT THU JUL 11 2013
OVERALL THE CURRENT FORECAST SEEMS TO BE ON TRACK. HIGH PRESSURE
ACROSS WISCONSIN AND IOWA WILL MOVE INTO THE LOWER GREAT LAKES BY
THIS EVENING. MADE SOME MINOR TWEAKS TO THE GRIDS MAINLY TO BACK
OFF ON SKY COVER A LITTLE MIDDAY OVER ALL BUT FAR EASTERN SECTIONS
PER RUC SOUNDINGS. LAV INDICATES TEMPERATURES MAY BE A TAD WARMER
SOME AREAS LATER TODAY. OTHERWISE...NO SIGNIFICANT CHANGES.
WILL UPDATE THE ZFP TO REFRESH WORDING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 218 AM EDT THU JUL 11 2013
MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUDS AND POSSIBILITY OF
SHOWERS SATURDAY AND SATURDAY NIGHT AS MODELS ARE NOW IN AGREEMENT
THAT AN UPPER LOW WILL BREAK FROM THE AFOREMENTIONED SHARP UPPER
TROUGH AND RETROGRADE WEST TOWARDS THE OHIO VALLEY UNDERCUTTING A
NORTHEASTWARD EXPANDING RIDGE OF HIGH PRESSURE. THE 00Z GFS AND 00Z
GEM IN AGREEMENT ON BRINGING THIS UPPER LOW ACROSS CENTRAL INDIANA
ON SATURDAY NIGHT...WHILE THE 00Z NAM AND 12Z ECMWF ARE SLOWER TO
BRING THIS FEATURE WEST...ONLY MOVING IT TO FAR EASTERN KENTUCKY OR
CENTRAL OHIO RESPECTIVELY BY 12Z SUNDAY. WITH POSITIONING AND TIMING
IN DOUBT...WILL LEAVE IT DRY FOR NOW THROUGH SATURDAY NIGHT BUT WITH
SOME INCREASE IN CLOUD COVER SATURDAY NIGHT. OTHERWISE...SHOULD ONLY
SEE SCATTERED DIURNAL CU WITH CLEAR NIGHTTIME SKIES AS BROAD SURFACE
HIGH PRESSURE GENERAL SETTLES ACROSS SOUTHERN ONTARIO AND QUEBEC
LATE IN THE SHORT TERM.
850 MILLIBAR TEMPERATURES WARM SLIGHTLY TO 14 TO 15 DEGREES CELSIUS
BY FRIDAY AS THE HIGH SHIFTS EAST OF THE AREA. PREFER THE SLIGHTLY
COOLER 00Z NAM MOS...WHICH IS CLOSE TO ALLBLEND...BASED ON THE 850
MILLIBAR PROGS. MEANWHILE...MOS THURSDAY AND FRIDAY NIGHTTIME
TEMPERATURES CLOSE AND APPEAR REASONABLE. WITH LIGHT NORTHEAST TO
CALM WINDS...EXPECT THE USUAL RURAL AND LOW LYING AREAS TO BE
SEVERAL DEGREES COOLER AT DAWN. WILL GO WITH A MODIFIED
ALLBLEND...AND MANUALLY LOWER THOSE AREAS A COUPLE OF DEGREES.
TEMPERATURES IN RURAL AREAS COULD FALL AS LOW AS THE MID 50S.
WITH A BIT MORE CLOUD COVER...TEMPERATURES WILL NOT BE AS COOL
SATURDAY NIGHT WITH OVERNIGHT LOWS IN THE LOWER TO MID 60S EXPECTED.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 259 AM EDT THU JUL 11 2013
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE AN UPPER
LEVEL LOW THAT ORIGINATES OVER THE NORTHEAST U.S. AND RETROGRADES
BACK INTO THE OHIO VALLEY AND CENTRAL U.S. LATEST INITIALIZATION
HAS COMPLETELY SWITCHED FROM A DRY FORECAST IN THE EXTENDED AS
ORIGINALLY FORECASTED THE LAST FEW NIGHTS...TO NOW BRINGING PRECIP
INTO CENTRAL INDIANA FOR THE MAJORITY OF EXTENDED PERIOD IN
ASSOCIATION WITH THAT UPPER LOW. FOR NOW...DECIDED TO GO WITH
SLIGHT CHANCE POPS OVER MOST OF THE PERIOD SINCE MODELS DO TAKE
THAT LOW MORE DIRECTLY OVER CENTRAL INDIANA NOW AS OPPOSED TO THE
TENNESSEE VALLEY INDICATED IN EARLIER RUNS. HOWEVER...WOULD NOT
PUT HIGH CONFIDENCE IN THIS FORECAST DUE TO THE DRASTIC SWITCH IN
MODELS FROM RUN TO RUN. A WARM MOIST ENVIRONMENT WILL BE IN PLACE
DAILY TO CONTRIBUTE TO DESTABILIZATION AND DIURNAL THUNDERSTORMS.
HIGH TEMPS WILL BE IN THE UPPER 80S WITH DEWPOINTS IN THE UPPER
60S/LOW 70S.
&&
.AVIATION /DISCUSSION FOR THE 111430Z TAF UPDATE/...
ISSUED AT 1012 AM EDT THU JUL 11 2013
NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION FOLLOWS...
VFR CONDITIONS EXPECTED FOR ENTIRE TAF PERIOD AS HIGH
PRESSURE/DRIER AIR FILTER INTO CENTRAL INDIANA. DIURNAL CU COULD
DEVELOP FROM 030-050...BUT NOTHING THAT WILL IMPACT OPERATIONS.
WINDS WILL BE NORTHEASTERLY AT 6 TO 12 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...JH
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...SMF/TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
955 AM EDT THU JUL 11 2013
.UPDATE...
NEAR TERM FOR THE REST OF TODAY HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 218 AM EDT THU JUL 11 2013
HIGH PRESSURE WILL BRING MOSTLY DRY WEATHER TO CENTRAL INDIANA
THROUGH SATURDAY NIGHT. THEN...AN UPPER LOW WILL MOVE WEST ACROSS
THE OHIO VALLEY WHICH COULD RESULT IN A FEW SHOWERS OR THUNDERSTORMS
LATE IN THE WEEKEND AND INTO NEXT WEEK. TEMPERATURES WILL BE BELOW
NORMAL THURSDAY AND FRIDAY WITH HIGHS IN THE UPPER 70S TO LOWER 80S.
TEMPERATURES SHOULD RETURN TO NEAR NORMAL LATE IN THE WEEKEND AND
EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 955 AM EDT THU JUL 11 2013
OVERALL THE CURRENT FORECAST SEEMS TO BE ON TRACK. HIGH PRESSURE
ACROSS WISCONSIN AND IOWA WILL MOVE INTO THE LOWER GREAT LAKES BY
THIS EVENING. MADE SOME MINOR TWEAKS TO THE GRIDS MAINLY TO BACK
OFF ON SKY COVER A LITTLE MIDDAY OVER ALL BUT FAR EASTERN SECTIONS
PER RUC SOUNDINGS. LAV INDICATES TEMPERATURES MAY BE A TAD WARMER
SOME AREAS LATER TODAY. OTHERWISE...NO SIGNIFICANT CHANGES.
WILL UPDATE THE ZFP TO REFRESH WORDING.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 218 AM EDT THU JUL 11 2013
MAIN CHALLENGE TO THE SHORT TERM WILL BE CLOUDS AND POSSIBILITY OF
SHOWERS SATURDAY AND SATURDAY NIGHT AS MODELS ARE NOW IN AGREEMENT
THAT AN UPPER LOW WILL BREAK FROM THE AFOREMENTIONED SHARP UPPER
TROUGH AND RETROGRADE WEST TOWARDS THE OHIO VALLEY UNDERCUTTING A
NORTHEASTWARD EXPANDING RIDGE OF HIGH PRESSURE. THE 00Z GFS AND 00Z
GEM IN AGREEMENT ON BRINGING THIS UPPER LOW ACROSS CENTRAL INDIANA
ON SATURDAY NIGHT...WHILE THE 00Z NAM AND 12Z ECMWF ARE SLOWER TO
BRING THIS FEATURE WEST...ONLY MOVING IT TO FAR EASTERN KENTUCKY OR
CENTRAL OHIO RESPECTIVELY BY 12Z SUNDAY. WITH POSITIONING AND TIMING
IN DOUBT...WILL LEAVE IT DRY FOR NOW THROUGH SATURDAY NIGHT BUT WITH
SOME INCREASE IN CLOUD COVER SATURDAY NIGHT. OTHERWISE...SHOULD ONLY
SEE SCATTERED DIURNAL CU WITH CLEAR NIGHTTIME SKIES AS BROAD SURFACE
HIGH PRESSURE GENERAL SETTLES ACROSS SOUTHERN ONTARIO AND QUEBEC
LATE IN THE SHORT TERM.
850 MILLIBAR TEMPERATURES WARM SLIGHTLY TO 14 TO 15 DEGREES CELSIUS
BY FRIDAY AS THE HIGH SHIFTS EAST OF THE AREA. PREFER THE SLIGHTLY
COOLER 00Z NAM MOS...WHICH IS CLOSE TO ALLBLEND...BASED ON THE 850
MILLIBAR PROGS. MEANWHILE...MOS THURSDAY AND FRIDAY NIGHTTIME
TEMPERATURES CLOSE AND APPEAR REASONABLE. WITH LIGHT NORTHEAST TO
CALM WINDS...EXPECT THE USUAL RURAL AND LOW LYING AREAS TO BE
SEVERAL DEGREES COOLER AT DAWN. WILL GO WITH A MODIFIED
ALLBLEND...AND MANUALLY LOWER THOSE AREAS A COUPLE OF DEGREES.
TEMPERATURES IN RURAL AREAS COULD FALL AS LOW AS THE MID 50S.
WITH A BIT MORE CLOUD COVER...TEMPERATURES WILL NOT BE AS COOL
SATURDAY NIGHT WITH OVERNIGHT LOWS IN THE LOWER TO MID 60S EXPECTED.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
ISSUED AT 259 AM EDT THU JUL 11 2013
THE MAIN FOCUS OF THE LONG TERM PERIOD CONTINUES TO BE AN UPPER
LEVEL LOW THAT ORIGINATES OVER THE NORTHEAST U.S. AND RETROGRADES
BACK INTO THE OHIO VALLEY AND CENTRAL U.S. LATEST INITIALIZATION
HAS COMPLETELY SWITCHED FROM A DRY FORECAST IN THE EXTENDED AS
ORIGINALLY FORECASTED THE LAST FEW NIGHTS...TO NOW BRINGING PRECIP
INTO CENTRAL INDIANA FOR THE MAJORITY OF EXTENDED PERIOD IN
ASSOCIATION WITH THAT UPPER LOW. FOR NOW...DECIDED TO GO WITH
SLIGHT CHANCE POPS OVER MOST OF THE PERIOD SINCE MODELS DO TAKE
THAT LOW MORE DIRECTLY OVER CENTRAL INDIANA NOW AS OPPOSED TO THE
TENNESSEE VALLEY INDICATED IN EARLIER RUNS. HOWEVER...WOULD NOT
PUT HIGH CONFIDENCE IN THIS FORECAST DUE TO THE DRASTIC SWITCH IN
MODELS FROM RUN TO RUN. A WARM MOIST ENVIRONMENT WILL BE IN PLACE
DAILY TO CONTRIBUTE TO DESTABILIZATION AND DIURNAL THUNDERSTORMS.
HIGH TEMPS WILL BE IN THE UPPER 80S WITH DEWPOINTS IN THE UPPER
60S/LOW 70S.
&&
.AVIATION /DISCUSSION FOR THE 11/1200Z TAF ISSUANCE/...
ISSUED AT 627 AM EDT THU JUL 11 2013
VFR CONDITIONS EXPECTED FOR ENTIRE TAF PERIOD AS HIGH
PRESSURE/DRIER AIR FILTER INTO CENTRAL INDIANA. DIURNAL CU COULD
DEVELOP FROM 030-050...BUT NOTHING THAT WILL IMPACT OPERATIONS.
WINDS WILL BE NORTHEASTERLY AT 6 TO 12 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...MK
NEAR TERM...JH
SHORT TERM...MK
LONG TERM....TDUD
AVIATION...TDUD
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
526 PM MDT FRI JUL 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1255 PM MDT FRI JUL 12 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 593 DM RIDGE EXTENDING
ACROSS THE PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY...WITH CLOSED
576 DM LOW OVER OHIO RIVER VALLEY DOWNSTREAM...AND TROUGH IN PLACE
ACROSS PACIFIC NORTHWEST. THIS RIDGE WILL KEEP VERY HOT TEMPS IN
PLACE THE NEXT FEW DAYS WITH MINIMAL PRECIP CHANCES.
IMMEDIATE CONCERN IS VERY HOT TEMPERATURES ACROSS THE AREA THIS
AFTERNOON. SOUTHERLY FLOW HAS KEPT TD VALUES AROUND 60F IN PLACE
ACROSS THE EASTERN PART OF OUR CWA...WHICH SHOULD SUPPORT HEAT
INDICES AROUND 105F DURING PEAK HEATING. THOUGH I COULD SEE THIS AS
A MARGINAL SITUATION...PER COORDINATION AND LOCAL GUIDANCE I WENT
AHEAD AND ISSUED AT HEAT ADVISORY THROUGH 00Z.
SHORT RANGE GUIDANCE CONTINUES TO SUPPORT THUNDERSTORM INITIATION
ALONG SURFACE TROUGH AXIS NEAR OUR CWA BORDER. WITHOUT LARGE SCALE
FORCING IN PLACE...THIS ACTIVITY WILL PROBABLY BE TIED TO PEAK
HEATING...WITH CHANCES QUICKLY DIMINISHING AFTER SUNSET. I WENT
AHEAD AND INCLUDED ISO THUNDER MENTION...THOUGH CONFIDENCE IS PRETTY
LOW. LCL VALUES ARE GENERALLY IN THE 12-14KFT RANGE AND WITH DEEP
DRY LAYER BELOW WE MAY NOT ACTUALLY SEE MUCH REGARDING MEASURABLE
PRECIP WITH ANY OF THESE STORMS THAT DO DEVELOP. WITH DCAPE IN
EXCESS OF 1500 J/KG IS ALSO FORECAST BY BOTH RAP AND NAM BY THIS
AFTERNOON...SO STRONG GUSTS ARE CERTAINLY POSSIBLE WITH THESE STORMS.
SURFACE TROUGH BEGINS TO SHIFT SOUTH AND EAST SATURDAY...WHICH COULD
ALLOW SLIGHTLY COOLER TEMPS (AT LEAST SUB 100F) TO MOVE INTO THE
NORTHWEST PART OF THE CWA. THIS COULD ALSO SHIFT SW FLOW FURTHER
SOUTH KEEPING TD VALUES LOWER WHERE HIGHEST TEMPS ARE...SO CHANCE
FOR HEAT INDICES AROUND 105 SEEMS MUCH LOWER. GUIDANCE IS STILL
SHOWING THUNDERSTORMS INITIATING IN THE EARLY AFTERNOON ALONG AND
BEHIND THIS TROUGH AXIS. IT LOOKS LIKE A VERY SIMILAR SITUATION AS
TODAY WITH LITTLE IN THE WAY OF FORCING BEYOND DESTABILIZATION ALONG
TROUGH AXIS IN THE AFTERNOON/EVENING. WE COULD SEE INITIATION FURTHER
EAST DEPENDING ON TROUGH LOCATION. AT THIS TIME I DECIDED AGAINST
EXPANDING POPS TOO FAR EAST...THOUGH NAM WOULD SUPPORT ACTIVITY OVER
MOST OF OUR CWA BY 00Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 225 PM MDT FRI JUL 12 2013
UPPER FLOW WILL BE IN TRANSITION SATURDAY NIGHT AS THE RIDGE SHIFTS
EAST AND A LOW RETROGRESSES WEST INTO THE MISSOURI RIVER VALLEY. THE
UPPER LOW WILL MOVE INTO THE SOUTHERN PLAINS BY SUNDAY EVENING AND
THE TEXAS PANHANDLE MONDAY. WEAK SURFACE LOW PRESSURE IS FORECAST TO
BE OVER EASTERN COLORADO/NEW MEXICO THROUGH SUNDAY. SURFACE HIGH
PRESSURE WILL RETROGRESS WEST INTO THE CENTRAL/SOUTHERN PLAINS
SUNDAY NIGHT AND MONDAY.
THE SURFACE TROUGH IN EASTERN COLORADO WILL SERVE AS A FOCUS FOR
THUNDERSTORM INITIATION SATURDAY EVENING AS THE NEXT IMPULSE COMES
THROUGH THE FLOW. MOISTURE IS LIMITED SO WILL STAY WITH A SLIGHT
CHANCE POP. DEEP EASTERLY FLOW WILL SET UP SUNDAY/SUNDAY NIGHT WITH
CONVERGENCE OVER THE HIGHER TERRAIN OF EASTERN COLORADO. THERE IS
GOOD LIFT OVER THE HIGHER TERRAIN SO PLAN TO GO WITH SLIGHT CHANCE
OVER MOST OF THE FA WITH CHANCE POPS OVER EASTERN COLORADO. FOR NOW
WILL KEEP MONDAY MORNING DRY BUT CANNOT RULE OUT SOME LINGERING
SHOWERS IN THE FAR WESTERN PORTIONS OF THE EASTERN COLORADO
ZONES. BY MONDAY AFTERNOON A SHORTWAVE AFFECTS THE SOUTHERN
FA AS IT ROTATES AROUND THE LOW INTO THE AREA. FOR NOW WILL GO WITH
SLIGHT CHANCE POPS FOR THIS FEATURE SINCE DYNAMICS ARE WEAK AND
TRANSITIONING WESTWARD.
TEMPERATURES ARE MORE CHALLENGING WITH 850 TEMPERATURES IN THE MID
20S INSTEAD OF THE MID 30S. AT THIS TIME MAX TEMPERATURES SUNDAY
WILL BE AROUND 90 WITH MID/UPPER 80S MONDAY. DEPENDING ON HOW MUCH
PRECIPITATION AND CLOUDS ARE AROUND COOLER MAX TEMPERATURES ARE
POSSIBLE. MIN TEMPERATURES WILL RANGE FROM THE UPPER 60S/LOWER 70S
SUNDAY NIGHT TO THE MID 60S MONDAY NIGHT.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...UPPER FLOW WILL BE
SOUTHEASTERLY WITH THE LOW OVER NEW MEXICO. THIS LOW WILL WEAKEN
WEDNESDAY NIGHT AND THURSDAY WITH A RIDGE BUILDING OVER THE PACIFIC
NORTHWEST FRIDAY. SURFACE HIGH PRESSURE WILL BE OVER THE REGION
MONDAY NIGHT. FROM TUESDAY THROUGH FRIDAY WEAK LOW PRESSURE WILL BE
OVER EASTERN COLORADO. NUMEROUS SHORTWAVES WILL COME THROUGH THE
FLOW PRODUCING AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE FA.
850 TEMPERATURES COOL TO THE UPPER TEENS AND MID 20S. THIS SHOULD
RESULT IN MAX TEMPERATURES RANGING FROM THE MID 80S TO AROUND 90.
MIN TEMPERATURES WILL RANGE IN THE 60S.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 523 PM MDT FRI JUL 12 2013
VFR CONDITIONS WILL OCCUR AT GLD AND MCK DURING THE NEXT 24
HOURS. A FEW THUNDERSTORMS HAVE DEVELOPED WELL WEST OF BOTH TAF
SITES ACROSS EAST CENTRAL COLORADO. THIS CONVECTION IS EXPECTED TO
REMAIN IN COLORADO AND SHOULD BE TOO ISOLATED AND INSIGIFICANT FOR
OUTFLOW AND RESULTANT WIND SHIFT TO MAKE IT INTO KANSAS AND NEBRASKA
THIS EVENING. HOWEVER...A SURFACE TROUGH WILL BE IN THE VICINITY
LATE TONIGHT AND TOMORROW RESULTING IS SOME UNCERTAINTY IN WIND
DIRECTION AND SPEED...ESPECIALLY TOWARD THE LATER PORTION OF THE
FORECAST PERIOD. ISOLATED THUNDERSTORMS WILL AGAIN DEVELOP TOMORROW
AFTERNOON BUT SHOULD REMAIN WEST OF BOTH SITES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ003-004-015-016.
CO...NONE.
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ080-081.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS WICHITA KS
104 PM CDT THU JUL 11 2013
.UPDATE...
ISSUED AT 1255 PM CDT THU JUL 11 2013
MAINTAINED WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS THROUGH AROUND 21Z
WITH REMNANT MESOSCALE VORTICITY CENTER OVER EAST CENTRAL KS BEFORE
THE ACTIVITY IS EXPECTED TO SLOWLY DIMINISH. DUE TO WIDESPREAD
RAIN AND CLOUD COVER...TRENDED HIGH TEMPERATURES DOWN WITH SOME
LOCATIONS STRUGGLING TO REACH 90. A STABLE AIRMASS IS ANTICIPATED
IN THE WAKE OF THE MORNING MCS WITH CLEARING SKIES LATER THIS
AFTERNOON.
MWM
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT THU JUL 11 2013
TODAY:
(+)TSRA CLUSTER CONTINUES OVER SW NEBRASKA/NW KS BORDER FROM ~KMCK SE
OVER DECATUR & NORTON COUNTIES. ANOTHER (+)TSRA THAT DEVELOPED OVER
ERN OSBORNE COUNTY IS STATIONARY. TSRA BEING SUSTAINED BY STRONG DEEP
ISENTROPIC ASCENT FROM 305-315K LAYER INDUCED BY BROAD HIGH PRESSURE
COVERING MOST OF UPR MS VALLEY & WEAK LOW PRESSURE SITUATED NEAR CO/KS
BORDER...FROM WHICH A WEAK NEARLY STATIONARY FRONT EXTENDS SE ACROSS
SW KS TO NRN OK. WELL-DEFINED RICH LWR-DECK MOISTURE AXIS IS ORIENTED
IN NW-SE MANNER ALONG & JUST NE OF THE BOUNDARY TO ALONG THE W/SW
CORRIDOR OF KICT COUNTRY. GREATEST CHANCES FOR TSRA TO THEREFORE OCCUR
OVER WRN HALF OF KICT COUNTRY THIS MORNING. HRRR DEPICTING A SIMILAR
PATTERN & AS SUCH HAVE INCREASED POPS TO 35-40% OVER THAT PART OF
CNTRL KS W OF I-135. AS LWR-DECK TROFFING GETS BETTER ESTABLISHED LWR
DECK FLOW TO BECOME MORE SLY WHICH WOULD REALIGN LWR-DECK MOISTURE
AXIS TO N-S ORIENTATION. WITH STRONG MASSIVE MID-UPR HIGH INCREASING
DOMINANCE FROM THE SRN TOWARD THE NRN PLAINS THE RESULTING INCREASED
SUBSIDENCE WOULD INHIBIT FURTHER TSRA DEVELOPMENT THIS AFTERNOON.
THE ALREADY STRONG MASSIVE HIGH PRESSURE BECOMES EVEN MORE SO OVER THE
NEXT 3 DAYS & WITH LWR-DECK TROFFING INCRESING OVER THE WRN PLAINS THE
FURNACE WILL REMAIN TURNED UP THRU SATURDAY. HIGHS ~100F ARE LIKELY
ALONG THE WRN CORRIDOR FRI & SAT WHERE HEAT INDICES ~105F ARE POSSIBLE.
AS SUCH A HEAT ADVISORY MAY BE REQUIRED...ESPECIALLY FRI. STAY TUNED.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU JUL 11 2013
TYPICAL MID-SUMMER STILL ANTICIPATED THROUGHOUT THESE PERIODS. HOWEVER
MID-RANGE MODELS (MORE SO THE GFS) DEPICT A MID-UPR LOW PRESSURE AREA
RETROGRADING ACROSS THE MID-MS VALLEY TOWARD...THEN ACROSS...THE MO/KS
BORDER ON MON. FOR NOW HAVE DRY FORECAST INTACT BUT THE BEHAVIOR OF THE
UNORTHODOX LOW WILL REQUIRE INCREASED ATTENTION LATER THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1255 PM CDT THU JUL 11 2013
A LARGE AREA OF SHOWERS AND THUNDERSTORMS RESULTED IN TRANSIENT AREAS
OF MVFR ACROSS PORTIONS OF CENTRAL AND SOUTH CENTRAL KANSAS
THROUGH THE MORNING HOURS. HOWEVER VFR HAS RETURNED ACROSS THE AREA
AND IS EXPECTED TO PERSIST THROUGH THE 24-HR PERIOD. SEVERAL
OUTFLOW BOUNDARIES HAVE ALLOWED GUSTY NORTHEAST WINDS TO
DEVELOP...HOWEVER WIND DIRECTION IS EXPECTED TO VEER TO THE
SOUTHEAST AS THE PBL BECOMES MIXED.
MWM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 91 72 99 77 / 20 30 0 0
HUTCHINSON 92 72 100 77 / 30 20 0 0
NEWTON 90 71 97 76 / 30 30 0 0
ELDORADO 90 71 97 75 / 40 30 0 0
WINFIELD-KWLD 92 73 99 76 / 30 30 0 0
RUSSELL 95 72 102 77 / 50 10 0 0
GREAT BEND 95 73 102 77 / 30 10 0 0
SALINA 90 72 101 77 / 100 30 0 0
MCPHERSON 91 72 100 77 / 60 20 0 0
COFFEYVILLE 93 71 97 73 / 10 20 0 0
CHANUTE 91 69 95 71 / 10 10 0 0
IOLA 90 68 94 71 / 10 10 0 0
PARSONS-KPPF 92 70 95 72 / 10 20 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1240 PM CDT THU JUL 11 2013
.UPDATE...
ISSUED AT 630 AM CDT THU JUL 11 2013
A VERY NARROW BAND OF MODERATE INSTABILITY APPEARS TO EXIST JUST
AHEAD OF A SHORT WAVE TROUGH MOVING INTO CENTRAL KANSAS. THE TIGHT
GRADIENT IN INSTABILITY SEEMS TO EXIST BETWEEN CONCORDIA WHERE
INSTABILITY IS MINIMAL AND SALINA WHERE RAP SOUNDINGS SUGGEST 1500
J/KG OF ELEVATED CAPE. SHORT TERM HI-RES MODELS SUGGEST THAT THE
WINDOW FOR THIS ELEVATED INSTABILITY IS FAIRLY SMALL NOT ONLY
SPATIALLY BUT ALSO IN TIME...AND WOULD EXPECT STORMS TO DIMINISH
IN COVERAGE AND INTENSITY THROUGH 9 AM. MAY SEE A FEW LINGERING
STORMS BEYOND 9 AM...BUT MOST INFORMATION POINTS TO DISSIPATION OF
ALL ACTIVITY BEFORE NOON. SO FAR...THE ONLY STORM TO POSE A SEVERE
RISK WAS OVER LINCOLN COUNTY IN A CELL THAT EXHIBITED MID LEVEL
ROTATION FOR 20 MINUTES OR SO AND INTENSIFIED ACCORDINGLY. THE
LIKELIHOOD OF THIS HAPPENING AGAIN IS LOW BUT NON-ZERO. ANY STRONG
STORMS WOULD POSE A RISK OF MARGINALLY SEVERE HAIL AND LOCALIZED
DOWNBURST WINDS AS THEY COLLAPSE. THE SLOW MOVEMENT OF THIS
ACTIVITY ALSO POINTS TO A LOCALIZED HEAVY RAINFALL POTENTIAL.
BARJENBRUCH
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT THU JUL 11 2013
A WEAK SHORT WAVE TROUGH EVIDENT IN WV IMAGERY AND MID LEVEL WIND
PROFILES WAS MOVING TO THE SOUTHEAST OUT OF SOUTHWEST NEBRASKA AT 3
AM. SEVERAL CLUSTERS OF THUNDERSTORMS WERE ONGOING OVER THE HIGH
PLAINS IN CONJUNCTION WITH THIS SYSTEM BUT WILL REMAIN WELL WEST OF
THE LOCAL FORECAST AREA. EAST OF THIS SYSTEM...FAIRLY WEAK LOW LEVEL
SOUTHERLY FLOW WAS BEING PULLED INTO CENTRAL KANSAS...RESULTING IN
WEAK BUT DEEP ISENTROPIC ASCENT. THIS ASCENT WAS WORKING WITH WEAK
ELEVATED INSTABILITY TO SPARK ISOLATED SHOWERS IN NORTH CENTRAL
KANSAS. THE ASCENT...AND THUS THE ISOLATED SHOWER ACTIVITY...SHOULD
PERSIST OVER NORTH CENTRAL KANSAS INTO THE MID MORNING HOURS WITH AN
OUTSIDE CHANCE FOR A FEW LIGHTNING STRIKES AS WELL ALTHOUGH THE
STRONGER INSTABILITY SEEMS TO BE WEST OF THE FORECAST AREA. ANY
PRECIP IS EXPECTED TO COME TO AN END BY NOON...WITH DRY CONDITIONS
EXPECTED THROUGH THE REST OF TODAY AND TONIGHT. TEMPERATURES SHOULD
WARM UP NICELY AGAIN TODAY AFTER MORNING LOWS IN THE UPPER 60S...AND
EXPECT HIGHS IN THE UPPER 80S TO LOWER 90S. MOSTLY CLEAR SKIES WILL
ALLOW A QUICK COOL DOWN THIS EVENING...AND WHILE A SOUTH BREEZE
SHOULD KEEP NORTH CENTRAL KANSAS IN THE UPPER 60S TO LOWER
70S...LIGHTER WINDS IN EASTERN KANSAS SHOULD CONTRIBUTE TO LOW TEMPS
IN THE MIDDLE 60S.
BARJENBRUCH
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU JUL 11 2013
MAIN MID LEVEL FEATURE BEING THE EXPANSIVE MID LEVEL RIDGE OVER THE
SOUTHWEST CONUS IS EXPECTED TO FINALLY MIGRATE EAST AS AN UPPER
SHORTWAVE TROUGH SETTLES AND BECOMES CUTOFF FROM THE MAIN FLOW
THROUGH THE WEEKEND. LATEST GFS TRIES TO BRING IN SOME SPOTTED
QPF TOWARDS THE NORTH CENTRAL AREAS ON FRIDAY MORNING...HOWEVER
WITH NO CLEAR LACK OF FORCING HAVE DECIDED TO LEAVE DRY AT THIS
TIME. MAIN STORY THEN TURNS TO THE HEAT AS A SURFACE TROUGH
SITUATED OVER EASTERN COLORADO WILL PROVIDE DECENT SOUTHWEST FLOW
AND AMPLE WARM ADVECTION. KEPT TRENDS IN PLACE WITH WARMEST HIGHS
FRIDAY NEAR 100 DEGREES OVER NORTH CENTRAL KS COINCIDING WITH
PROXIMITY OF THERMAL AXIS. SLIGHTLY COOLER TEMPS IN THE LOW 90S
EXPECTED FOR THE EAST CENTRAL/NORTHEAST AREAS...HOWEVER WITH
DEWPOINT VALUES IN THE 60S ADVECTING INTO THE AREA WILL MAKE IT
FEEL NEAR THE CENTURY MARK OR A FEW DEGREES HIGHER FRIDAY INTO
SATURDAY. LITTLE CHANGE OCCURS FOR SATURDAY EXCEPT WARM LOWS
SATURDAY MORNING IN THE 70S WILL ALLOW TEMPS ONCE AGAIN TO RISE TO
THE CENTURY MARK OVER NORTH CENTRAL KS. NOTING TRENDS AND
PERFORMANCE OF THE GFS AND NAM MOS GUIDANCE LEAD TO GOING A FEW
DEGREES ABOVE OUTPUT FOR HIGHS ON FRIDAY/SATURDAY.
UNCERTAINTY INCREASES STEADILY AS WE HEAD INTO THE EXTENDED PERIOD.
LATEST RUNS OF THE GFS/ECMWF PUSH THE H5 RIDGE BACK WEST AS THE
CLOSED TROUGH OVER THE NORTHEAST CONUS RETROGRADES WESTWARD
INFLUENCED BY ANOTHER RIDGE BUILDING OVER THE ATLANTIC. POSITION AND
WESTERN EXTENT OF THIS TROUGH MAY MEAN THE DIFFERENCE BETWEEN A VERY
WET OR DRY PERIOD. IF THE CURRENT GFS/ECMWF CAME TO FRUITION WE MAY
SEE PERIODS OF SHOWERS AND THUNDERSTORMS THROUGHOUT NEXT
WEEK...GREATLY IMPACTING THE TEMPERATURES IN CURRENT FORECAST. SINCE
THIS SCENARIO HAS NOT BEEN CONSISTENT WITH RECENT SOLUTIONS WILL
KEEP A DRY FORECAST FOR NOW ASSUMING THE RIDGE INFLUENCES THE AREA
WITH THE TROUGH POSITIONED FURTHER EAST. WILL MONITOR IN THE
UPCOMING FORECASTS AND MAKE CHANGES IF NEEDED. SURFACE HIGH PRESSURE
IN PLACE WILL KEEP TEMPERATURES NEAR THE NORMAL VALUES IN THE LOW TO
MID 90S FOR HIGHS AND LOWS IN THE UPPER 60S TO LOW 70S THROUGH
THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1240 PM CDT THU JUL 11 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. WINDS EAST AROUND 10
KTS THROUGH 01Z THEN BECOMING LIGHT. WINDS WILL INCREASE FROM THE
SOUTHEAST BY 15Z FRIDAY TO AROUND 12KTS WITH SOME GUSTS NEAR
21 KTS BY 18Z. CONVECTION IS EXPECTED TO REMAIN SOUTHWEST OF THE
TERMINALS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BARJENBRUCH
LONG TERM...BOWEN
AVIATION...53
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1206 PM CDT THU JUL 11 2013
...UPDATED SYNOPSIS AND AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 1204 PM CDT THU JUL 11 2013
AT 12Z THURSDAY A +110KT 250MB JET EXTENDED FROM NORTHERN
CALIFORNIA INTO NORTHWEST MONTANA. THIS WAS LOCATED ON THE
NORTHWEST SIDE OF AN UPPER LEVEL LOW THAT WAS CENTERED OVER NEW
MEXICO BASED ON THE 500MB ANALYSIS. AN UPPER LEVEL RIDGE AXIS
EXTENDED FROM NEW MEXICO NORTH INTO CENTRAL CANADA. A 500MB LOW
WAS LOCATED OVER BRITISH COLUMBIA. 700MB TEMPERATURES AT 12Z
THURSDAY RANGED FROM +4C AT DODGE CITY TO +7C AT NORTH PLATTE AND
AMARILLO TO +16C AT DENVER. A WEDGE OF HIGHER DEWPOINTS APPEAR
EXTEND FROM AMARILLO TO NORTH PLATTE WHICH WAS NEAR THE +12C
ISOTHERM. A 850MB HIGH WAS LOCATED OVER EASTERN KANSAS. WEST OF
THIS HIGH THE WINDS WERE FROM THE SOUTH AND DEWPOINTS RANGED FROM
+9 AT DODGE CITY TO +11C AND AMARILLO AND +17C AT NORTH PLATTE. A
SURFACE BOUNDARY EARLIER THIS MORNING EXTENDED FROM NORTHEAST
COLORADO INTO NORTHWEST OKLAHOMA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU JUL 11 2013
THE SURFACE FRONT THAT WAS LOCATED ACROSS SOUTHWEST KANSAS
WEDNESDAY AFTERNOON WAS GETTING ANOTHER BOOST SOUTHWARD FROM
OVERNIGHT THUNDERSTORM OUTFLOW. UPPER LEVEL RIDGING WILL BE EDGING
BACK OVER THE CENTRAL PLAINS OVER THE NEXT 24 TO 36 HRS. HOWEVER,
THE EFFECTIVE FRONTAL BOUNDARY MAY BE SLOW TO MOVE BACK TO THE NORTH
TODAY. INSTEAD OF MORE OF A SOUTHERLY WIND PER THE NAM MODEL, WITH
TEMPERATURES REACHING 100-102F, MORE OF A SOUTHEASTERLY UPSLOPE WIND
MAY SERVE TO KEEP TEMPERATURES FROM REACHING 100F PER RAP MODEL
(WITH MID TO UPPER 90S MORE LIKELY. IN ADDITION, ANY ONGOING
CONVECTION OVER SOUTH CENTRAL AND CENTRAL KANSAS THIS MORNING COULD
HELP KEEP TEMPERATURES COOLER ALONG A MEDICINE LODGE TO HAYS
CORRIDOR THIS AFTERNOON DUE TO OUTFLOW FROM THE SOUTHEAST. KEEP
IN MIND THAT LEE TROUGHING WILL BE STRENGTENING IN THE LEE OF THE
ROCKIES THIS AFTERNOON IN REPONSE TO STRONG SOUTHWEST MID LEVEL
FLOW ACROSS THE NORTHERN ROCKIES. THIS WOULD TEND TO PROMOTE
MORE OF A SOUTH WIND AND HOTTER TEMPERATURES FOR TODAY. SO DESPITE
THE OUTFLOW, I WOULD NOT BE SURPRISED IF TEMPERATURES ROSE TO OVER
100 DEGREES IN DODGE CITY BY THIS AFTERNOON--HENCE THE FORECAST
UNCERTAINTY. BY LATE AFTERNOON, A CORRIDOR OF 2000 J/KG SURFACE
BASED CAPE WILL BE SITUATED FROM DODGE CITY TO DIGHTON AND SCOTT
CITY. ISOLATED THUNDERSTORMS CANNOT BE RULED OUT. UPPER LEVEL WINDS
WILL BE QUITE A BIT WEAKER TODAY THAN ON WEDNESDAY ALONG THE
INTERSTATE 70 CORRIDOR SO THAT ANY HAIL WOULD BE QUARTER SIZE OR
SMALLER. ANY CONVECTION THAT DEVELOPS LATE THIS AFTERNOON SHOULD
WEAKEN THIS EVENING WITH THE LOSS OF DAYTIME HEATING GIVEN THE LACK
OF UPPER LEVEL SUPPORT. TEMPERATURES TONIGHT WILL BE HELD UP BY
SOUTH WINDS, WITH LOWS IN THE LOWER TO MID 70S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 254 AM CDT THU JUL 11 2013
A RETURN TO HOT AND DRY CONDITIONS IS FORECAST FOR FRIDAY SATURDAY
AND POSSIBLY BEYOND, AS AN UPPER HIGH PRESSURE RIDGE ROTATES INTO THE
HIGH PLAINS REGION AND BECOMES STATIONARY FOR A FEW DAYS. FORECAST
MODELS DO SHOW CONSIDERABLE SPREAD FROM AROUND 100 DEGREES INTO THE
MID 100`S BOTH DAY AS THE WARM BOUNDARY LAYER PLUME OVERSPREAD THE
AREA WITH 27-30 DEGREES C 850 MB AIR. IF THE WARMEST OF FORECAST
SOLUTIONS VERIFY ACROSS CENTRAL KANSAS, DANGEROUS HEAT INDICES COULD
BE ACHIEVED IN THE AFTERNOON. THE PATTERN BECOMES MORE FLATTENED
AFTER FRIDAY, AND JUST HOW WARM THE HIGHS GET IN THE AFTERNOON ARE
LESS CLEAR. BY MONDAY, THE ECMWF SHOWS A FRONT IN THE VICINITY OF
NORTHWEST KANSAS AND SW NEBRASKA. THAT KIND OF PATTERN WOULD
RELEGATE STORMS TO THE FRONT WITH A LACK OF STEERING FLOW. A RESULT
OF THE NEARLY STATIONARY UPPER HIGH WILL BE SURFACE WINDS BECOMING
MORE LIGHT AND VARIABLE WITH TIME AS THE SUBSIDENCE INDUCED SURFACE
HIGH MAINTAINS INCREASING HIGH PRESSURE FROM THE NORTHERN PLAINS.
LIGHT AND VARIABLE OR LIGHT EASTERLY FLOW WOULD SUPPORT NOT AS HOT
TEMPERATURES IN THE MID TO UPPER 90S AND LOWER FREQUENCIES OF 100
DEGREE AND HIGH READINGS. ISOLATED ELEVATED THUNDERSTORMS CAN`T BE
RULED OUT COMPLETELY MID TO LATE WEEK AS MODELS SHOW A SUBTLE SIGNAL
OF MID LEVEL MOISTURE SPREADING NORTHWARD ON THE BACK SIDES OF THE
UPPER HIGH PRESSURE. CONFIDENCE IS TOO LOW HOWEVER TO RAISE THE
CURRENT ALLBLEND APPROACH OF SINGLE DIGIT PRECIPITATION
PROBABILITIES DURING THIS TIMEFRAME. .
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1204 PM CDT THU JUL 11 2013
A WEAK SURFACE BOUNDARY WILL LIFT NORTHEAST ACROSS WESTERN KANSAS
THROUGH THE LATE AFTERNOON. AS THIS BOUNDARY PASSES...SOUTHERLY
WINDS WILL DEVELOP WITH LIGHT WINDS INCREASING TO NEAR 15 MPH BY
LATE DAY. A FEW LATE DAY CLOUDS WILL BE POSSIBLE AND BASED ON THE
LATEST BUFR SOUNDING TH CLOUD BASES WILL BE AT OR ABOVE 5000 FT.
AS A RESULT VFR CONDITIONS ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 99 74 104 74 / 20 10 0 0
GCK 99 74 104 73 / 20 20 0 0
EHA 98 73 103 71 / 10 10 0 0
LBL 99 74 104 73 / 20 10 0 0
HYS 97 75 104 75 / 20 20 0 0
P28 97 75 102 75 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...FINCH
LONG TERM...RUSSELL
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1100 AM MDT THU JUL 11 2013
.UPDATE...
ISSUED AT 549 AM MDT THU JUL 11 2013
LESS CONVECTION AROUND AT THIS TIME THAN PREVIOUSLY ANTICIPATED.
THERE STILL OUTFLOW BOUNDARIES AROUND SO LEFT IN A 20 TO 30
PERCENT CHANCE THROUGH 15Z. ALSO ADJUSTED SKY COVER AND WINDS
BASED ON LATEST TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT THU JUL 11 2013
FORECAST CONCERNS WILL BE CHANCE OF THUNDERSTORMS FOLLOWED BY HOW
HOT DOES IT GET ALONG WITH POSSIBLE HEAT HIGHLIGHTS. SATELLITE
SHOWING A RATHER AMPLIFIED PATTERN FROM THE PACIFIC IN CENTRAL NORTH
AMERICA. MOISTURE AND WEAK SHORTWAVE TROUGHS ROTATING AROUND UPPER
HIGH CENTERED TO OUR SOUTH/SOUTHWEST. FRONTAL BOUNDARY AT THIS TIME
REMAINS DRAPED TO OUR SOUTH AND WEST.
AT MID LEVELS...THE UKMET FOLLOWED BY THE CANADIAN AND GFS WERE
DOING BEST ON WHERE THE CENTER OF THE MID/UPPER HIGH WAS AND THE
RESULTING HEIGHT FIELD OVER THE AREA. OUTFLOW BOUNDARIES ARE
MESSING UP THE WIND FIELD RIGHT AND THE HRRR HAS THE RIGHT IDEA ON
IT. UKMET AND CANADIAN WERE DOING A LITTLE BETTER THAN THE GFS AND
ECMWF ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...HOW MUCH THUNDERSTORM ACTIVITY WILL BE AROUND THIS
MORNING AND LINGERING MESOSCALE AFFECTS FROM THESE THUNDERSTORMS WILL
BE AROUND FOR THE ENTIRE DAY ARE THE BIG QUESTIONS WHICH MAY BE VERY
HARD TO ANSWER. PERSISTENT CLUSTER OF THUNDERSTORMS REMAINS OVER THE
EASTERN PORTION OF THE AREA. THIS AREA WAS THE RESULT A WEAK
SHORTWAVE IN THE AREA BUT MOST OF ALL THE COLLISION OF OUTFLOW
BOUNDARIES. OUTFLOW BOUNDARIES ABOUND ACROSS THE AREA PER RADAR AND
SURFACE OBSERVATIONS AND ESPECIALLY IN THE EASTERN AND CENTRAL
PORTION. ELEVATED CAPE AND LACK OF STRONG ELEVATED CINH WILL BE
AROUND AT THE BEGINNING OF THE DAY. ADDITIONAL DEVELOPMENT IS
OCCURRING AND IS EXPECTED TO CONTINUE TO OCCUR. SO ISSUED THE ZONES
WITH A PRE-FIRST PERIOD AND KEPT POPS AROUND IN THE MORNING...
ESPECIALLY IN THE EAST. WILL CONTINUE TO MONITOR AND WILL ISSUE AN
UPDATE NEAR 12Z TO ACCOUNT FOR THE LATEST TRENDS WHICH THE MODELS ARE
PLAYING CATCH UP WITH.
NOT ACCOUNTING FOR MESOSCALE INFLUENCES OVERNIGHT GUIDANCE HAD THE
HIGHEST INSTABILITY AND LOWEST 700 MB TEMPERATURES IN THE EASTERN
PORTION OF THE AREA. AT 500 MB WEAK SHORTWAVE IS MOVING ACROSS THE
EASTERN HALF IN THE AFTERNOON. AT 700 MB A SHORTWAVE TROUGH BEGINS
TO AFFECT THE WESTERN PORTION BUT THE 700 MB TEMPERATURES ARE MUCH
WARMER. SATELLITE WOULD ALSO INDICATE ANOTHER INFLUX OF MID LEVEL
SUBTROPICAL MOISTURE FROM THE WEST. AND THE BIGGEST VARIABLE IS
WHERE WILL THERE BE LEFTOVER OUTFLOW BOUNDARIES. WOULD SAY THERE IS
A GOOD PROBABILITY OF ONE OR MORE IN THE CENTRAL AND EASTERN PORTION
OF THE AREA. SO TO ACCOUNT FOR THIS...PUT SLIGHT CHANCE IN THE WEST
AND LOW CHANCE IN THE EAST.
DEPENDING ON HOW PERSISTENT THE CONVECTION STAYS...HOW MUCH CLOUD
COVER HANGS AROUND...AND HOW SIGNIFICANT THE OUTFLOW IS...HIGH
TEMPERATURES MAY BE SEVERELY AFFECTED. BELIEVE THIS CONVECTION WILL
ALSO KEEP THE SYNOPTIC FRONT SUPPRESSED FURTHER TO THE SOUTH AND
WEST. KEPT THE COOLEST EAST AND THE WARMEST WEST BUT THAT IS HIGHLY
PROBLEMATIC AT THIS POINT.
FRIDAY/FRIDAY NIGHT...IN REGARDS TO THE PRECIPITATION...NEWEST MODEL
GUIDANCE SUPPORTS THE PREVIOUS FORECAST VERY WELL. RIDGE STARTS
BUILDING INTO THE AREA BUT THE MODELS DISAGREE ON HOW MUCH. MID
LEVEL TEMPERATURES WARM AND IT DOES LOOK LIKE MOST OF THE FORECAST
AREA EAST OF THE COLORADO BORDER DOES STAY CAPPED. A SURFACE TROUGH
SUPPLYING LOW LEVEL CONVERGENCE ALONG WITH A WEAK SHORTWAVE AFFECT
THE FAR WESTERN PORTION OF THE AREA WHICH IS WHERE THE 700 MB
TEMPERATURES ARE THE WARMEST. SO MADE LITTLE IF ANY CHANGE TO THE
PRECIPITATION FORECAST. NEW GUIDANCE SUPPORTS WARMING UP NOT ONLY
MAXES BUT THE MINS AS WELL. MOST OF THE AREA SHOULD BE ABOVE 100
DEGREES WITH THE EASTERN HALF THE HOTTEST FOR THE MAXES.
THIS COULD BE THE BEGINNING OF AN EXTENDED HEAT HIGHLIGHT FOR THE
EASTERN PORTION OF THE AREA. HEAT INDICES IN THE AFTERNOON REACH
105 IN THE EASTERN SIX COUNTIES DURING THE DAY. THEN OVERNIGHT MINS
DO NOT DROP OFF VERY MUCH AND I ACTUALLY MAY BE TOO COOL.
SATURDAY/SATURDAY NIGHT...SIMILAR SCENARIO FOR PRECIPITATION THESE
TWO PERIODS AS THE PREVIOUS TWO. THE MID/UPPER RIDGE LOOKS TO BUILD
IN MORE WITH HIGHER 700 MB TEMPERATURES AND ALSO LESS SURFACE
CONVERGENCE NEAR THE WESTERN END OF THE FORECAST AREA. WEAK LIFT IN
ADDITION TO THE EXTREME HEATING...COULD HELP SET OFF A FEW
THUNDERSTORMS. ALMOST CANNOT HELP BUT INITIATE THUNDERSTORMS IN
THIS KIND OF HEATING. CURRENT FORECAST HAD THIS SCENARIO WELL IN
HAND AND DID NOT CHANGE ANYTHING. MODELS LOOK TO INCREASE THE HEAT.
IT IS POSSIBLE I STILL DO NOT HAVE THE MAXES HOT ENOUGH...ESPECIALLY
IN THE EASTERN HALF. MINS LOOKS JUST AS WARM OR WARMER THAN THE
PREVIOUS NIGHT.
HEAT INDICES OF 105 PUSH ONE ROW OF COUNTIES FURTHER WEST THAN THE
PREVIOUS DAY. AM NOT ISSUING A HEAT HIGHLIGHT YET...BUT PLAN ON
MENTIONING THE FRIDAY INTO SATURDAY NIGHT PERIOD IN THE HWO.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM MDT THU JUL 11 2013
A LARGER THAN NORMAL DEGREE OF UNCERTAINTY IN THE EXTENDED
ON THE SYNOPTIC SCALE...THOUGH MOST SOLUTIONS END UP WITH SIMILAR
CONDITIONS FOR THE HIGH PLAINS. MAIN STORY EARLY NEXT WEEK WILL BE
HIGHS NEAR TO SLIGHTLY ABOVE NORMAL WITH GENERALLY DRY CONDITIONS.
ON SUNDAY A WEAK UPPER LEVEL DISTURBANCE MOVES ACROSS THE CENTRAL
ROCKIES AND INTO THE HIGH PLAINS...WHICH COULD HELP TO DEVELOP A FEW
SHOWERS/STORMS ON SUNDAY AFTERNOON INTO THE EVENING. TEMPS WILL BE
WARMEST ON SUNDAY WITH 850 TEMPS IN THE MID TO UPPER 20S...THOUGH
THE EC IS AN OUTLIER WITH SLIGHTLY COOLER TEMPS. THE REST OF THEE
WEEK MOST DETERMINISTIC GUIDANCE SHOWS AN UPPER LOW OVER MID-WEST
AND MOVING WEST AS IT WEAKENS...THOUGH AT THIS POINT BELIEVE THE
UPPER LOW WILL REMAIN FARTHER EAST AND AN UPPER RIDGE WILL BE OVER
HIGH PLAINS KEEPING THINGS DRY. 850 TEMPS FOR THE REST OF THE WEEK
WILL BE IN THE MID 20S IN THE AFTERNOON...WHICH WILL LEAD TO NEAR
NORMAL HIGHS. WHILE RAIN IS NOT ANTICIPATED THROUGH MOST OF THE WORK
WEEK...AT THIS POINT IT DOES NOT APPEAR FIRE WX WILL BE A CONCERN
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1040 AM MDT THU JUL 11 2013
VFR CONDITIONS ARE EXPECTED AT KGLD AND KMCK FOR THE NEXT 24
HOURS. NO THUNDERSTORMS ARE EXPECTED AS VERY WARM MID LEVEL
TEMPERATURES AND SUBSIDENCE WILL INHIBIT THUNDERSTORMS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...FS
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
715 AM CDT THU JUL 11 2013
...UPDATED FOR AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU JUL 11 2013
THE SURFACE FRONT THAT WAS LOCATED ACROSS SOUTHWEST KANSAS
WEDNESDAY AFTERNOON WAS GETTING ANOTHER BOOST SOUTHWARD FROM
OVERNIGHT THUNDERSTORM OUTFLOW. UPPER LEVEL RIDGING WILL BE EDGING
BACK OVER THE CENTRAL PLAINS OVER THE NEXT 24 TO 36 HRS. HOWEVER,
THE EFFECTIVE FRONTAL BOUNDARY MAY BE SLOW TO MOVE BACK TO THE NORTH
TODAY. INSTEAD OF MORE OF A SOUTHERLY WIND PER THE NAM MODEL, WITH
TEMPERATURES REACHING 100-102F, MORE OF A SOUTHEASTERLY UPSLOPE WIND
MAY SERVE TO KEEP TEMPERATURES FROM REACHING 100F PER RAP MODEL
(WITH MID TO UPPER 90S MORE LIKELY. IN ADDITION, ANY ONGOING
CONVECTION OVER SOUTH CENTRAL AND CENTRAL KANSAS THIS MORNING COULD
HELP KEEP TEMPERATURES COOLER ALONG A MEDICINE LODGE TO HAYS
CORRIDOR THIS AFTERNOON DUE TO OUTFLOW FROM THE SOUTHEAST. KEEP
IN MIND THAT LEE TROUGHING WILL BE STRENGTENING IN THE LEE OF THE
ROCKIES THIS AFTERNOON IN REPONSE TO STRONG SOUTHWEST MID LEVEL
FLOW ACROSS THE NORTHERN ROCKIES. THIS WOULD TEND TO PROMOTE
MORE OF A SOUTH WIND AND HOTTER TEMPERATURES FOR TODAY. SO DESPITE
THE OUTFLOW, I WOULD NOT BE SURPRISED IF TEMPERATURES ROSE TO OVER
100 DEGREES IN DODGE CITY BY THIS AFTERNOON--HENCE THE FORECAST
UNCERTAINTY. BY LATE AFTERNOON, A CORRIDOR OF 2000 J/KG SURFACE
BASED CAPE WILL BE SITUATED FROM DODGE CITY TO DIGHTON AND SCOTT
CITY. ISOLATED THUNDERSTORMS CANNOT BE RULED OUT. UPPER LEVEL WINDS
WILL BE QUITE A BIT WEAKER TODAY THAN ON WEDNESDAY ALONG THE
INTERSTATE 70 CORRIDOR SO THAT ANY HAIL WOULD BE QUARTER SIZE OR
SMALLER. ANY CONVECTION THAT DEVELOPS LATE THIS AFTERNOON SHOULD
WEAKEN THIS EVENING WITH THE LOSS OF DAYTIME HEATING GIVEN THE LACK
OF UPPER LEVEL SUPPORT. TEMPERATURES TONIGHT WILL BE HELD UP BY
SOUTH WINDS, WITH LOWS IN THE LOWER TO MID 70S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 254 AM CDT THU JUL 11 2013
A RETURN TO HOT AND DRY CONDITIONS IS FORECAST FOR FRIDAY SATURDAY
AND POSSIBLY BEYOND, AS AN UPPER HIGH PRESSURE RIDGE ROTATES INTO THE
HIGH PLAINS REGION AND BECOMES STATIONARY FOR A FEW DAYS. FORECAST
MODELS DO SHOW CONSIDERABLE SPREAD FROM AROUND 100 DEGREES INTO THE
MID 100`S BOTH DAY AS THE WARM BOUNDARY LAYER PLUME OVERSPREAD THE
AREA WITH 27-30 DEGREES C 850 MB AIR. IF THE WARMEST OF FORECAST
SOLUTIONS VERIFY ACROSS CENTRAL KANSAS, DANGEROUS HEAT INDICES COULD
BE ACHIEVED IN THE AFTERNOON. THE PATTERN BECOMES MORE FLATTENED
AFTER FRIDAY, AND JUST HOW WARM THE HIGHS GET IN THE AFTERNOON ARE
LESS CLEAR. BY MONDAY, THE ECMWF SHOWS A FRONT IN THE VICINITY OF
NORTHWEST KANSAS AND SW NEBRASKA. THAT KIND OF PATTERN WOULD
RELEGATE STORMS TO THE FRONT WITH A LACK OF STEERING FLOW. A RESULT
OF THE NEARLY STATIONARY UPPER HIGH WILL BE SURFACE WINDS BECOMING
MORE LIGHT AND VARIABLE WITH TIME AS THE SUBSIDENCE INDUCED SURFACE
HIGH MAINTAINS INCREASING HIGH PRESSURE FROM THE NORTHERN PLAINS.
LIGHT AND VARIABLE OR LIGHT EASTERLY FLOW WOULD SUPPORT NOT AS HOT
TEMPERATURES IN THE MID TO UPPER 90S AND LOWER FREQUENCIES OF 100
DEGREE AND HIGH READINGS. ISOLATED ELEVATED THUNDERSTORMS CAN`T BE
RULED OUT COMPLETELY MID TO LATE WEEK AS MODELS SHOW A SUBTLE SIGNAL
OF MID LEVEL MOISTURE SPREADING NORTHWARD ON THE BACK SIDES OF THE
UPPER HIGH PRESSURE. CONFIDENCE IS TOO LOW HOWEVER TO RAISE THE
CURRENT ALLBLEND APPROACH OF SINGLE DIGIT PRECIPITATION
PROBABILITIES DURING THIS TIMEFRAME. .
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 714 AM CDT THU JUL 11 2013
CONVECTION CONTINUES TO SHIFT FARTHER INTO NORTH CENTRAL KANSAS,
AWAY FROM THE KHYS TERMINAL. VFR CONDITIONS WILL PREVAIL ACROSS THE
AREA THROUGH THE DAY. ONLY ISOLATED THUNDERSTORMS ARE EXPECTED IN
THE LATE AFTERNOON, TOO LOW TO CONSIDER FOR ANY TERMINAL.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 99 73 104 74 / 20 10 0 0
GCK 99 73 104 73 / 20 20 0 0
EHA 98 72 103 71 / 10 10 0 0
LBL 99 72 104 73 / 20 10 0 0
HYS 97 73 104 75 / 20 20 0 0
P28 97 74 102 75 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...FINCH
LONG TERM...RUSSELL
AVIATION...RUSSELL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
555 AM MDT THU JUL 11 2013
.UPDATE...
ISSUED AT 549 AM MDT THU JUL 11 2013
LESS CONVECTION AROUND AT THIS TIME THAN PREVIOUSLY ANTICIPATED.
THERE STILL OUTFLOW BOUNDARIES AROUND SO LEFT IN A 20 TO 30
PERCENT CHANCE THROUGH 15Z. ALSO ADJUSTED SKY COVER AND WINDS
BASED ON LATEST TRENDS.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT THU JUL 11 2013
FORECAST CONCERNS WILL BE CHANCE OF THUNDERSTORMS FOLLOWED BY HOW
HOT DOES IT GET ALONG WITH POSSIBLE HEAT HIGHLIGHTS. SATELLITE
SHOWING A RATHER AMPLIFIED PATTERN FROM THE PACIFIC IN CENTRAL NORTH
AMERICA. MOISTURE AND WEAK SHORTWAVE TROUGHS ROTATING AROUND UPPER
HIGH CENTERED TO OUR SOUTH/SOUTHWEST. FRONTAL BOUNDARY AT THIS TIME
REMAINS DRAPED TO OUR SOUTH AND WEST.
AT MID LEVELS...THE UKMET FOLLOWED BY THE CANADIAN AND GFS WERE
DOING BEST ON WHERE THE CENTER OF THE MID/UPPER HIGH WAS AND THE
RESULTING HEIGHT FIELD OVER THE AREA. OUTFLOW BOUNDARIES ARE
MESSING UP THE WIND FIELD RIGHT AND THE HRRR HAS THE RIGHT IDEA ON
IT. UKMET AND CANADIAN WERE DOING A LITTLE BETTER THAN THE GFS AND
ECMWF ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...HOW MUCH THUNDERSTORM ACTIVITY WILL BE AROUND THIS
MORNING AND LINGERING MESOSCALE AFFECTS FROM THESE THUNDERSTORMS WILL
BE AROUND FOR THE ENTIRE DAY ARE THE BIG QUESTIONS WHICH MAY BE VERY
HARD TO ANSWER. PERSISTENT CLUSTER OF THUNDERSTORMS REMAINS OVER THE
EASTERN PORTION OF THE AREA. THIS AREA WAS THE RESULT A WEAK
SHORTWAVE IN THE AREA BUT MOST OF ALL THE COLLISION OF OUTFLOW
BOUNDARIES. OUTFLOW BOUNDARIES ABOUND ACROSS THE AREA PER RADAR AND
SURFACE OBSERVATIONS AND ESPECIALLY IN THE EASTERN AND CENTRAL
PORTION. ELEVATED CAPE AND LACK OF STRONG ELEVATED CINH WILL BE
AROUND AT THE BEGINNING OF THE DAY. ADDITIONAL DEVELOPMENT IS
OCCURRING AND IS EXPECTED TO CONTINUE TO OCCUR. SO ISSUED THE ZONES
WITH A PRE-FIRST PERIOD AND KEPT POPS AROUND IN THE MORNING...
ESPECIALLY IN THE EAST. WILL CONTINUE TO MONITOR AND WILL ISSUE AN
UPDATE NEAR 12Z TO ACCOUNT FOR THE LATEST TRENDS WHICH THE MODELS ARE
PLAYING CATCH UP WITH.
NOT ACCOUNTING FOR MESOSCALE INFLUENCES OVERNIGHT GUIDANCE HAD THE
HIGHEST INSTABILITY AND LOWEST 700 MB TEMPERATURES IN THE EASTERN
PORTION OF THE AREA. AT 500 MB WEAK SHORTWAVE IS MOVING ACROSS THE
EASTERN HALF IN THE AFTERNOON. AT 700 MB A SHORTWAVE TROUGH BEGINS
TO AFFECT THE WESTERN PORTION BUT THE 700 MB TEMPERATURES ARE MUCH
WARMER. SATELLITE WOULD ALSO INDICATE ANOTHER INFLUX OF MID LEVEL
SUBTROPICAL MOISTURE FROM THE WEST. AND THE BIGGEST VARIABLE IS
WHERE WILL THERE BE LEFTOVER OUTFLOW BOUNDARIES. WOULD SAY THERE IS
A GOOD PROBABILITY OF ONE OR MORE IN THE CENTRAL AND EASTERN PORTION
OF THE AREA. SO TO ACCOUNT FOR THIS...PUT SLIGHT CHANCE IN THE WEST
AND LOW CHANCE IN THE EAST.
DEPENDING ON HOW PERSISTENT THE CONVECTION STAYS...HOW MUCH CLOUD
COVER HANGS AROUND...AND HOW SIGNIFICANT THE OUTFLOW IS...HIGH
TEMPERATURES MAY BE SEVERELY AFFECTED. BELIEVE THIS CONVECTION WILL
ALSO KEEP THE SYNOPTIC FRONT SUPPRESSED FURTHER TO THE SOUTH AND
WEST. KEPT THE COOLEST EAST AND THE WARMEST WEST BUT THAT IS HIGHLY
PROBLEMATIC AT THIS POINT.
FRIDAY/FRIDAY NIGHT...IN REGARDS TO THE PRECIPITATION...NEWEST MODEL
GUIDANCE SUPPORTS THE PREVIOUS FORECAST VERY WELL. RIDGE STARTS
BUILDING INTO THE AREA BUT THE MODELS DISAGREE ON HOW MUCH. MID
LEVEL TEMPERATURES WARM AND IT DOES LOOK LIKE MOST OF THE FORECAST
AREA EAST OF THE COLORADO BORDER DOES STAY CAPPED. A SURFACE TROUGH
SUPPLYING LOW LEVEL CONVERGENCE ALONG WITH A WEAK SHORTWAVE AFFECT
THE FAR WESTERN PORTION OF THE AREA WHICH IS WHERE THE 700 MB
TEMPERATURES ARE THE WARMEST. SO MADE LITTLE IF ANY CHANGE TO THE
PRECIPITATION FORECAST. NEW GUIDANCE SUPPORTS WARMING UP NOT ONLY
MAXES BUT THE MINS AS WELL. MOST OF THE AREA SHOULD BE ABOVE 100
DEGREES WITH THE EASTERN HALF THE HOTTEST FOR THE MAXES.
THIS COULD BE THE BEGINNING OF AN EXTENDED HEAT HIGHLIGHT FOR THE
EASTERN PORTION OF THE AREA. HEAT INDICES IN THE AFTERNOON REACH
105 IN THE EASTERN SIX COUNTIES DURING THE DAY. THEN OVERNIGHT MINS
DO NOT DROP OFF VERY MUCH AND I ACTUALLY MAY BE TOO COOL.
SATURDAY/SATURDAY NIGHT...SIMILAR SCENARIO FOR PRECIPITATION THESE
TWO PERIODS AS THE PREVIOUS TWO. THE MID/UPPER RIDGE LOOKS TO BUILD
IN MORE WITH HIGHER 700 MB TEMPERATURES AND ALSO LESS SURFACE
CONVERGENCE NEAR THE WESTERN END OF THE FORECAST AREA. WEAK LIFT IN
ADDITION TO THE EXTREME HEATING...COULD HELP SET OFF A FEW
THUNDERSTORMS. ALMOST CANNOT HELP BUT INITIATE THUNDERSTORMS IN
THIS KIND OF HEATING. CURRENT FORECAST HAD THIS SCENARIO WELL IN
HAND AND DID NOT CHANGE ANYTHING. MODELS LOOK TO INCREASE THE HEAT.
IT IS POSSIBLE I STILL DO NOT HAVE THE MAXES HOT ENOUGH...ESPECIALLY
IN THE EASTERN HALF. MINS LOOKS JUST AS WARM OR WARMER THAN THE
PREVIOUS NIGHT.
HEAT INDICES OF 105 PUSH ONE ROW OF COUNTIES FURTHER WEST THAN THE
PREVIOUS DAY. AM NOT ISSUING A HEAT HIGHLIGHT YET...BUT PLAN ON
MENTIONING THE FRIDAY INTO SATURDAY NIGHT PERIOD IN THE HWO.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM MDT THU JUL 11 2013
A LARGER THAN NORMAL DEGREE OF UNCERTAINTY IN THE EXTENDED
ON THE SYNOPTIC SCALE...THOUGH MOST SOLUTIONS END UP WITH SIMILAR
CONDITIONS FOR THE HIGH PLAINS. MAIN STORY EARLY NEXT WEEK WILL BE
HIGHS NEAR TO SLIGHTLY ABOVE NORMAL WITH GENERALLY DRY CONDITIONS.
ON SUNDAY A WEAK UPPER LEVEL DISTURBANCE MOVES ACROSS THE CENTRAL
ROCKIES AND INTO THE HIGH PLAINS...WHICH COULD HELP TO DEVELOP A FEW
SHOWERS/STORMS ON SUNDAY AFTERNOON INTO THE EVENING. TEMPS WILL BE
WARMEST ON SUNDAY WITH 850 TEMPS IN THE MID TO UPPER 20S...THOUGH
THE EC IS AN OUTLIER WITH SLIGHTLY COOLER TEMPS. THE REST OF THEE
WEEK MOST DETERMINISTIC GUIDANCE SHOWS AN UPPER LOW OVER MID-WEST
AND MOVING WEST AS IT WEAKENS...THOUGH AT THIS POINT BELIEVE THE
UPPER LOW WILL REMAIN FARTHER EAST AND AN UPPER RIDGE WILL BE OVER
HIGH PLAINS KEEPING THINGS DRY. 850 TEMPS FOR THE REST OF THE WEEK
WILL BE IN THE MID 20S IN THE AFTERNOON...WHICH WILL LEAD TO NEAR
NORMAL HIGHS. WHILE RAIN IS NOT ANTICIPATED THROUGH MOST OF THE WORK
WEEK...AT THIS POINT IT DOES NOT APPEAR FIRE WX WILL BE A CONCERN
NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 549 AM MDT THU JUL 11 2013
VFR CONDITIONS ARE EXPECTED FOR BOTH SITES AT THIS TIME. OVERNIGHT
THUNDERSTORMS HAS CAUSED THE WIND FIELD TO BECOME LIGHT AND
VARIABLE. SOME HEATING WILL HAVE TO TAKE PLACE BEFORE SOUTHERLY
WINDS INCREASE AND BECOME GUSTY. THIS GUSTINESS SHOULD LAST INTO
THE EVENING HOURS. UNCERTAIN THUNDERSTORM FORECAST DUE TO
MESOSCALE INFLUENCES OF OVERNIGHT CONVECTION. AT THIS TIME THE
GREATEST CHANCE OF THUNDERSTORMS WILL BE IN THE EAST. AT THIS TIME
CHOSE TO HANDLE THAT WITH VCTS AT KMCK.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
642 AM CDT THU JUL 11 2013
...UPDATE FOR AVIATION AND SHORT TERM THUNDERSTORM FORECAST...
.UPDATE...
ISSUED AT 630 AM CDT THU JUL 11 2013
A VERY NARROW BAND OF MODERATE INSTABILITY APPEARS TO EXIST JUST
AHEAD OF A SHORT WAVE TROUGH MOVING INTO CENTRAL KANSAS. THE TIGHT
GRADIENT IN INSTABILITY SEEMS TO EXIST BETWEEN CONCORDIA WHERE
INSTABILITY IS MINIMAL AND SALINA WHERE RAP SOUNDINGS SUGGEST 1500
J/KG OF ELEVATED CAPE. SHORT TERM HI-RES MODELS SUGGEST THAT THE
WINDOW FOR THIS ELEVATED INSTABILITY IS FAIRLY SMALL NOT ONLY
SPATIALLY BUT ALSO IN TIME...AND WOULD EXPECT STORMS TO DIMINISH
IN COVERAGE AND INTENSITY THROUGH 9 AM. MAY SEE A FEW LINGERING
STORMS BEYOND 9 AM...BUT MOST INFORMATION POINTS TO DISSIPATION OF
ALL ACTIVITY BEFORE NOON. SO FAR...THE ONLY STORM TO POSE A SEVERE
RISK WAS OVER LINCOLN COUNTY IN A CELL THAT EXHIBITED MID LEVEL
ROTATION FOR 20 MINUTES OR SO AND INTENSIFIED ACCORDINGLY. THE
LIKELIHOOD OF THIS HAPPENING AGAIN IS LOW BUT NON-ZERO. ANY STRONG
STORMS WOULD POSE A RISK OF MARGINALLY SEVERE HAIL AND LOCALIZED
DOWNBURST WINDS AS THEY COLLAPSE. THE SLOW MOVEMENT OF THIS
ACTIVITY ALSO POINTS TO A LOCALIZED HEAVY RAINFALL POTENTIAL.
BARJENBRUCH
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 333 AM CDT THU JUL 11 2013
A WEAK SHORT WAVE TROUGH EVIDENT IN WV IMAGERY AND MID LEVEL WIND
PROFILES WAS MOVING TO THE SOUTHEAST OUT OF SOUTHWEST NEBRASKA AT 3
AM. SEVERAL CLUSTERS OF THUNDERSTORMS WERE ONGOING OVER THE HIGH
PLAINS IN CONJUNCTION WITH THIS SYSTEM BUT WILL REMAIN WELL WEST OF
THE LOCAL FORECAST AREA. EAST OF THIS SYSTEM...FAIRLY WEAK LOW LEVEL
SOUTHERLY FLOW WAS BEING PULLED INTO CENTRAL KANSAS...RESULTING IN
WEAK BUT DEEP ISENTROPIC ASCENT. THIS ASCENT WAS WORKING WITH WEAK
ELEVATED INSTABILITY TO SPARK ISOLATED SHOWERS IN NORTH CENTRAL
KANSAS. THE ASCENT...AND THUS THE ISOLATED SHOWER ACTIVITY...SHOULD
PERSIST OVER NORTH CENTRAL KANSAS INTO THE MID MORNING HOURS WITH AN
OUTSIDE CHANCE FOR A FEW LIGHTNING STRIKES AS WELL ALTHOUGH THE
STRONGER INSTABILITY SEEMS TO BE WEST OF THE FORECAST AREA. ANY
PRECIP IS EXPECTED TO COME TO AN END BY NOON...WITH DRY CONDITIONS
EXPECTED THROUGH THE REST OF TODAY AND TONIGHT. TEMPERATURES SHOULD
WARM UP NICELY AGAIN TODAY AFTER MORNING LOWS IN THE UPPER 60S...AND
EXPECT HIGHS IN THE UPPER 80S TO LOWER 90S. MOSTLY CLEAR SKIES WILL
ALLOW A QUICK COOL DOWN THIS EVENING...AND WHILE A SOUTH BREEZE
SHOULD KEEP NORTH CENTRAL KANSAS IN THE UPPER 60S TO LOWER
70S...LIGHTER WINDS IN EASTERN KANSAS SHOULD CONTRIBUTE TO LOW TEMPS
IN THE MIDDLE 60S.
BARJENBRUCH
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 333 AM CDT THU JUL 11 2013
MAIN MID LEVEL FEATURE BEING THE EXPANSIVE MID LEVEL RIDGE OVER THE
SOUTHWEST CONUS IS EXPECTED TO FINALLY MIGRATE EAST AS AN UPPER
SHORTWAVE TROUGH SETTLES AND BECOMES CUTOFF FROM THE MAIN FLOW
THROUGH THE WEEKEND. LATEST GFS TRIES TO BRING IN SOME SPOTTED
QPF TOWARDS THE NORTH CENTRAL AREAS ON FRIDAY MORNING...HOWEVER
WITH NO CLEAR LACK OF FORCING HAVE DECIDED TO LEAVE DRY AT THIS
TIME. MAIN STORY THEN TURNS TO THE HEAT AS A SURFACE TROUGH
SITUATED OVER EASTERN COLORADO WILL PROVIDE DECENT SOUTHWEST FLOW
AND AMPLE WARM ADVECTION. KEPT TRENDS IN PLACE WITH WARMEST HIGHS
FRIDAY NEAR 100 DEGREES OVER NORTH CENTRAL KS COINCIDING WITH
PROXIMITY OF THERMAL AXIS. SLIGHTLY COOLER TEMPS IN THE LOW 90S
EXPECTED FOR THE EAST CENTRAL/NORTHEAST AREAS...HOWEVER WITH
DEWPOINT VALUES IN THE 60S ADVECTING INTO THE AREA WILL MAKE IT
FEEL NEAR THE CENTURY MARK OR A FEW DEGREES HIGHER FRIDAY INTO
SATURDAY. LITTLE CHANGE OCCURS FOR SATURDAY EXCEPT WARM LOWS
SATURDAY MORNING IN THE 70S WILL ALLOW TEMPS ONCE AGAIN TO RISE TO
THE CENTURY MARK OVER NORTH CENTRAL KS. NOTING TRENDS AND
PERFORMANCE OF THE GFS AND NAM MOS GUIDANCE LEAD TO GOING A FEW
DEGREES ABOVE OUTPUT FOR HIGHS ON FRIDAY/SATURDAY.
UNCERTAINTY INCREASES STEADILY AS WE HEAD INTO THE EXTENDED PERIOD.
LATEST RUNS OF THE GFS/ECMWF PUSH THE H5 RIDGE BACK WEST AS THE
CLOSED TROUGH OVER THE NORTHEAST CONUS RETROGRADES WESTWARD
INFLUENCED BY ANOTHER RIDGE BUILDING OVER THE ATLANTIC. POSITION AND
WESTERN EXTENT OF THIS TROUGH MAY MEAN THE DIFFERENCE BETWEEN A VERY
WET OR DRY PERIOD. IF THE CURRENT GFS/ECMWF CAME TO FRUITION WE MAY
SEE PERIODS OF SHOWERS AND THUNDERSTORMS THROUGHOUT NEXT
WEEK...GREATLY IMPACTING THE TEMPERATURES IN CURRENT FORECAST. SINCE
THIS SCENARIO HAS NOT BEEN CONSISTENT WITH RECENT SOLUTIONS WILL
KEEP A DRY FORECAST FOR NOW ASSUMING THE RIDGE INFLUENCES THE AREA
WITH THE TROUGH POSITIONED FURTHER EAST. WILL MONITOR IN THE
UPCOMING FORECASTS AND MAKE CHANGES IF NEEDED. SURFACE HIGH PRESSURE
IN PLACE WILL KEEP TEMPERATURES NEAR THE NORMAL VALUES IN THE LOW TO
MID 90S FOR HIGHS AND LOWS IN THE UPPER 60S TO LOW 70S THROUGH
THURSDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING) ISSUED AT
630 AM CDT WED JUL 10 2013
VFR CONDITIONS ARE FORECAST THROUGH THE TAF PERIOD AT ALL SITES.
EAST WINDS MAY GUST A BIT DURING THE LATE MORNING HOURS BUT ANY
GUSTS SHOULD EVEN BE BELOW 18 KTS AND SHORT LIVED. MHK HAS A VERY
SMALL CHANCE FOR ISOLATED TS AFFECTING TAF SITE THROUGH 16Z...BUT
NOT A GOOD ENOUGH CHANCE TO MENTION IN THE TAF.
BARJENBRUCH
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BARJENBRUCH
LONG TERM...BOWEN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS WICHITA KS
637 AM CDT THU JUL 11 2013
...AVIATION UPDATE...
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT THU JUL 11 2013
TODAY:
(+)TSRA CLUSTER CONTINUES OVER SW NEBRASKA/NW KS BORDER FROM ~KMCK SE
OVER DECATUR & NORTON COUNTIES. ANOTHER (+)TSRA THAT DEVELOPED OVER
ERN OSBORNE COUNTY IS STATIONARY. TSRA BEING SUSTAINED BY STRONG DEEP
ISENTROPIC ASCENT FROM 305-315K LAYER INDUCED BY BROAD HIGH PRESSURE
COVERING MOST OF UPR MS VALLEY & WEAK LOW PRESSURE SITUATED NEAR CO/KS
BORDER...FROM WHICH A WEAK NEARLY STATIONARY FRONT EXTENDS SE ACROSS
SW KS TO NRN OK. WELL-DEFINED RICH LWR-DECK MOISTURE AXIS IS ORIENTED
IN NW-SE MANNER ALONG & JUST NE OF THE BOUNDARY TO ALONG THE W/SW
CORRIDOR OF KICT COUNTRY. GREATEST CHANCES FOR TSRA TO THEREFORE OCCUR
OVER WRN HALF OF KICT COUNTRY THIS MORNING. HRRR DEPICTING A SIMILAR
PATTERN & AS SUCH HAVE INCREASED POPS TO 35-40% OVER THAT PART OF
CNTRL KS W OF I-135. AS LWR-DECK TROFFING GETS BETTER ESTABLISHED LWR
DECK FLOW TO BECOME MORE SLY WHICH WOULD REALIGN LWR-DECK MOISTURE
AXIS TO N-S ORIENTATION. WITH STRONG MASSIVE MID-UPR HIGH INCREASING
DOMINANCE FROM THE SRN TOWARD THE NRN PLAINS THE RESULTING INCREASED
SUBSIDENCE WOULD INHIBIT FURTHER TSRA DEVELOPMENT THIS AFTERNOON.
THE ALREADY STRONG MASSIVE HIGH PRESSURE BECOMES EVEN MORE SO OVER THE
NEXT 3 DAYS & WITH LWR-DECK TROFFING INCRESING OVER THE WRN PLAINS THE
FURNACE WILL REMAIN TURNED UP THRU SATURDAY. HIGHS ~100F ARE LIKELY
ALONG THE WRN CORRIDOR FRI & SAT WHERE HEAT INDICES ~105F ARE POSSIBLE.
AS SUCH A HEAT ADVISORY MAY BE REQUIRED...ESPECIALLY FRI. STAY TUNED.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU JUL 11 2013
TYPICAL MID-SUMMER STILL ANTICIPATED THROUGHOUT THESE PERIODS. HOWEVER
MID-RANGE MODELS (MORE SO THE GFS) DEPICT A MID-UPR LOW PRESSURE AREA
RETROGRADING ACROSS THE MID-MS VALLEY TOWARD...THEN ACROSS...THE MO/KS
BORDER ON MON. FOR NOW HAVE DRY FORECAST INTACT BUT THE BEHAVIOR OF THE
UNORTHODOX LOW WILL REQUIRE INCREASED ATTENTION LATER THIS WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 634 AM CDT THU JUL 11 2013
SCATTERED STRONG CONVECTION WILL AFFECT PORTIONS OF CENTRAL AND
SOUTH CENTRAL KANSAS THIS MORNING. OTHERWISE VFR CONDITIONS ARE
EXPECTED FOR THE REMAINDER OF THE FORECAST VALID PERIOD. WINDS
WILL GRADUALLY VEER MORE TO THE SOUTHEAST AND BECOME OCCASIONALLY
GUSTY ACROSS CENTRAL KANSAS THIS AFTERNOON AND EVENING.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 97 72 99 77 / 30 0 0 0
HUTCHINSON 96 72 100 77 / 40 0 0 0
NEWTON 94 71 97 76 / 30 0 0 0
ELDORADO 93 71 97 75 / 20 0 0 0
WINFIELD-KWLD 96 73 99 76 / 30 0 0 0
RUSSELL 95 72 102 77 / 40 10 0 0
GREAT BEND 96 73 102 77 / 40 10 0 0
SALINA 93 72 101 77 / 30 10 0 0
MCPHERSON 94 72 100 77 / 40 0 0 0
COFFEYVILLE 92 71 97 73 / 10 0 0 0
CHANUTE 89 69 95 71 / 10 0 0 0
IOLA 90 68 94 71 / 10 0 0 0
PARSONS-KPPF 91 70 95 72 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
415 AM MDT THU JUL 11 2013
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 415 AM MDT THU JUL 11 2013
FORECAST CONCERNS WILL BE CHANCE OF THUNDERSTORMS FOLLOWED BY HOW
HOT DOES IT GET ALONG WITH POSSIBLE HEAT HIGHLIGHTS. SATELLITE
SHOWING A RATHER AMPLIFIED PATTERN FROM THE PACIFIC IN CENTRAL NORTH
AMERICA. MOISTURE AND WEAK SHORTWAVE TROUGHS ROTATING AROUND UPPER
HIGH CENTERED TO OUR SOUTH/SOUTHWEST. FRONTAL BOUNDARY AT THIS TIME
REMAINS DRAPED TO OUR SOUTH AND WEST.
AT MID LEVELS...THE UKMET FOLLOWED BY THE CANADIAN AND GFS WERE
DOING BEST ON WHERE THE CENTER OF THE MID/UPPER HIGH WAS AND THE
RESULTING HEIGHT FIELD OVER THE AREA. OUTFLOW BOUNDARIES ARE
MESSING UP THE WIND FIELD RIGHT AND THE HRRR HAS THE RIGHT IDEA ON
IT. UKMET AND CANADIAN WERE DOING A LITTLE BETTER THAN THE GFS AND
ECMWF ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...HOW MUCH THUNDERSTORM ACTIVITY WILL BE AROUND THIS
MORNING AND LINGERING MESOSCALE AFFECTS FROM THESE THUNDERSTORMS WILL
BE AROUND FOR THE ENTIRE DAY ARE THE BIG QUESTIONS WHICH MAY BE VERY
HARD TO ANSWER. PERSISTENT CLUSTER OF THUNDERSTORMS REMAINS OVER THE
EASTERN PORTION OF THE AREA. THIS AREA WAS THE RESULT A WEAK
SHORTWAVE IN THE AREA BUT MOST OF ALL THE COLLISION OF OUTFLOW
BOUNDARIES. OUTFLOW BOUNDARIES ABOUND ACROSS THE AREA PER RADAR AND
SURFACE OBSERVATIONS AND ESPECIALLY IN THE EASTERN AND CENTRAL
PORTION. ELEVATED CAPE AND LACK OF STRONG ELEVATED CINH WILL BE
AROUND AT THE BEGINNING OF THE DAY. ADDITIONAL DEVELOPMENT IS
OCCURRING AND IS EXPECTED TO CONTINUE TO OCCUR. SO ISSUED THE ZONES
WITH A PRE-FIRST PERIOD AND KEPT POPS AROUND IN THE MORNING...
ESPECIALLY IN THE EAST. WILL CONTINUE TO MONITOR AND WILL ISSUE AN
UPDATE NEAR 12Z TO ACCOUNT FOR THE LATEST TRENDS WHICH THE MODELS ARE
PLAYING CATCH UP WITH.
NOT ACCOUNTING FOR MESOSCALE INFLUENCES OVERNIGHT GUIDANCE HAD THE
HIGHEST INSTABILITY AND LOWEST 700 MB TEMPERATURES IN THE EASTERN
PORTION OF THE AREA. AT 500 MB WEAK SHORTWAVE IS MOVING ACROSS THE
EASTERN HALF IN THE AFTERNOON. AT 700 MB A SHORTWAVE TROUGH BEGINS
TO AFFECT THE WESTERN PORTION BUT THE 700 MB TEMPERATURES ARE MUCH
WARMER. SATELLITE WOULD ALSO INDICATE ANOTHER INFLUX OF MID LEVEL
SUBTROPICAL MOISTURE FROM THE WEST. AND THE BIGGEST VARIABLE IS
WHERE WILL THERE BE LEFTOVER OUTFLOW BOUNDARIES. WOULD SAY THERE IS
A GOOD PROBABILITY OF ONE OR MORE IN THE CENTRAL AND EASTERN PORTION
OF THE AREA. SO TO ACCOUNT FOR THIS...PUT SLIGHT CHANCE IN THE WEST
AND LOW CHANCE IN THE EAST.
DEPENDING ON HOW PERSISTENT THE CONVECTION STAYS...HOW MUCH CLOUD
COVER HANGS AROUND...AND HOW SIGNIFICANT THE OUTFLOW IS...HIGH
TEMPERATURES MAY BE SEVERELY AFFECTED. BELIEVE THIS CONVECTION WILL
ALSO KEEP THE SYNOPTIC FRONT SUPPRESSED FURTHER TO THE SOUTH AND
WEST. KEPT THE COOLEST EAST AND THE WARMEST WEST BUT THAT IS HIGHLY
PROBLEMATIC AT THIS POINT.
FRIDAY/FRIDAY NIGHT...IN REGARDS TO THE PRECIPITATION...NEWEST MODEL
GUIDANCE SUPPORTS THE PREVIOUS FORECAST VERY WELL. RIDGE STARTS
BUILDING INTO THE AREA BUT THE MODELS DISAGREE ON HOW MUCH. MID
LEVEL TEMPERATURES WARM AND IT DOES LOOK LIKE MOST OF THE FORECAST
AREA EAST OF THE COLORADO BORDER DOES STAY CAPPED. A SURFACE TROUGH
SUPPLYING LOW LEVEL CONVERGENCE ALONG WITH A WEAK SHORTWAVE AFFECT
THE FAR WESTERN PORTION OF THE AREA WHICH IS WHERE THE 700 MB
TEMPERATURES ARE THE WARMEST. SO MADE LITTLE IF ANY CHANGE TO THE
PRECIPITATION FORECAST. NEW GUIDANCE SUPPORTS WARMING UP NOT ONLY
MAXES BUT THE MINS AS WELL. MOST OF THE AREA SHOULD BE ABOVE 100
DEGREES WITH THE EASTERN HALF THE HOTTEST FOR THE MAXES.
THIS COULD BE THE BEGINNING OF AN EXTENDED HEAT HIGHLIGHT FOR THE
EASTERN PORTION OF THE AREA. HEAT INDICES IN THE AFTERNOON REACH
105 IN THE EASTERN SIX COUNTIES DURING THE DAY. THEN OVERNIGHT MINS
DO NOT DROP OFF VERY MUCH AND I ACTUALLY MAY BE TOO COOL.
SATURDAY/SATURDAY NIGHT...SIMILAR SCENARIO FOR PRECIPITATION THESE
TWO PERIODS AS THE PREVIOUS TWO. THE MID/UPPER RIDGE LOOKS TO BUILD
IN MORE WITH HIGHER 700 MB TEMPERATURES AND ALSO LESS SURFACE
CONVERGENCE NEAR THE WESTERN END OF THE FORECAST AREA. WEAK LIFT IN
ADDITION TO THE EXTREME HEATING...COULD HELP SET OFF A FEW
THUNDERSTORMS. ALMOST CANNOT HELP BUT INITIATE THUNDERSTORMS IN
THIS KIND OF HEATING. CURRENT FORECAST HAD THIS SCENARIO WELL IN
HAND AND DID NOT CHANGE ANYTHING. MODELS LOOK TO INCREASE THE HEAT.
IT IS POSSIBLE I STILL DO NOT HAVE THE MAXES HOT ENOUGH...ESPECIALLY
IN THE EASTERN HALF. MINS LOOKS JUST AS WARM OR WARMER THAN THE
PREVIOUS NIGHT.
HEAT INDICES OF 105 PUSH ONE ROW OF COUNTIES FURTHER WEST THAN THE
PREVIOUS DAY. AM NOT ISSUING A HEAT HIGHLIGHT YET...BUT PLAN ON
MENTIONING THE FRIDAY INTO SATURDAY NIGHT PERIOD IN THE HWO.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 415 AM MDT THU JUL 11 2013
A LARGER THAN NORMAL DEGREE OF UNCERTAINTY IN THE EXTENDED
ON THE SYNOPTIC SCALE...THOUGH MOST SOLUTIONS END UP WITH SIMILAR
CONDITIONS FOR THE HIGH PLAINS. MAIN STORY EARLY NEXT WEEK WILL BE
HIGHS NEAR TO SLIGHTLY ABOVE NORMAL WITH GENERALLY DRY CONDITIONS.
ON SUNDAY A WEAK UPPER LEVEL DISTURBANCE MOVES ACROSS THE CENTRAL
ROCKIES AND INTO THE HIGH PLAINS...WHICH COULD HELP TO DEVELOP A FEW
SHOWERS/STORMS ON SUNDAY AFTERNOON INTO THE EVENING. TEMPS WILL BE
WARMEST ON SUNDAY WITH 850 TEMPS IN THE MID TO UPPER 20S...THOUGH
THE EC IS AN OUTLIER WITH SLIGHTLY COOLER TEMPS. THE REST OF THEE
WEEK MOST DETERMINISTIC GUIDANCE SHOWS AN UPPER LOW OVER MID-WEST
AND MOVING WEST AS IT WEAKENS...THOUGH AT THIS POINT BELIEVE THE
UPPER LOW WILL REMAIN FARTHER EAST AND AN UPPER RIDGE WILL BE OVER
HIGH PLAINS KEEPING THINGS DRY. 850 TEMPS FOR THE REST OF THE WEEK
WILL BE IN THE MID 20S IN THE AFTERNOON...WHICH WILL LEAD TO NEAR
NORMAL HIGHS. WHILE RAIN IS NOT ANTICIPATED THROUGH MOST OF THE WORK
WEEK...AT THIS POINT IT DOES NOT APPEAR FIRE WX WILL BE A CONCERN
NEXT WEEK.
&&
.AVIATION....(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 413 AM MDT THU JUL 11 2013
THUNDERSTORMS WILL BE NEAR KMCK THROUGH 12Z AND LATEST AMENDMENT
TAKES CARE OF THIS. THUNDERSTORM DEVELOPMENT IS EXPECTED TO BE
FURTHER EAST THIS AFTERNOON AND COULD AFFECT THE KMCK SITE. THIS
WILL BE ADDRESSED IN THE NEXT TAF ISSUANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...JJM
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
401 AM CDT THU JUL 11 2013
...UPDATED FOR SHORT TERM DISCUSSION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT THU JUL 11 2013
THE SURFACE FRONT THAT WAS LOCATED ACROSS SOUTHWEST KANSAS
WEDNESDAY AFTERNOON WAS GETTING ANOTHER BOOST SOUTHWARD FROM
OVERNIGHT THUNDERSTORM OUTFLOW. UPPER LEVEL RIDGING WILL BE EDGING
BACK OVER THE CENTRAL PLAINS OVER THE NEXT 24 TO 36 HRS. HOWEVER,
THE EFFECTIVE FRONTAL BOUNDARY MAY BE SLOW TO MOVE BACK TO THE NORTH
TODAY. INSTEAD OF MORE OF A SOUTHERLY WIND PER THE NAM MODEL, WITH
TEMPERATURES REACHING 100-102F, MORE OF A SOUTHEASTERLY UPSLOPE WIND
MAY SERVE TO KEEP TEMPERATURES FROM REACHING 100F PER RAP MODEL
(WITH MID TO UPPER 90S MORE LIKELY. IN ADDITION, ANY ONGOING
CONVECTION OVER SOUTH CENTRAL AND CENTRAL KANSAS THIS MORNING COULD
HELP KEEP TEMPERATURES COOLER ALONG A MEDICINE LODGE TO HAYS
CORRIDOR THIS AFTERNOON DUE TO OUTFLOW FROM THE SOUTHEAST. KEEP
IN MIND THAT LEE TROUGHING WILL BE STRENGTENING IN THE LEE OF THE
ROCKIES THIS AFTERNOON IN REPONSE TO STRONG SOUTHWEST MID LEVEL
FLOW ACROSS THE NORTHERN ROCKIES. THIS WOULD TEND TO PROMOTE
MORE OF A SOUTH WIND AND HOTTER TEMPERATURES FOR TODAY. SO DESPITE
THE OUTFLOW, I WOULD NOT BE SURPRISED IF TEMPERATURES ROSE TO OVER
100 DEGREES IN DODGE CITY BY THIS AFTERNOON--HENCE THE FORECAST
UNCERTAINTY. BY LATE AFTERNOON, A CORRIDOR OF 2000 J/KG SURFACE
BASED CAPE WILL BE SITUATED FROM DODGE CITY TO DIGHTON AND SCOTT
CITY. ISOLATED THUNDERSTORMS CANNOT BE RULED OUT. UPPER LEVEL WINDS
WILL BE QUITE A BIT WEAKER TODAY THAN ON WEDNESDAY ALONG THE
INTERSTATE 70 CORRIDOR SO THAT ANY HAIL WOULD BE QUARTER SIZE OR
SMALLER. ANY CONVECTION THAT DEVELOPS LATE THIS AFTERNOON SHOULD
WEAKEN THIS EVENING WITH THE LOSS OF DAYTIME HEATING GIVEN THE LACK
OF UPPER LEVEL SUPPORT. TEMPERATURES TONIGHT WILL BE HELD UP BY
SOUTH WINDS, WITH LOWS IN THE LOWER TO MID 70S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 254 AM CDT THU JUL 11 2013
A RETURN TO HOT AND DRY CONDITIONS IS FORECAST FOR FRIDAY SATURDAY
AND POSSIBLY BEYOND, AS AN UPPER HIGH PRESSURE RIDGE ROTATES INTO THE
HIGH PLAINS REGION AND BECOMES STATIONARY FOR A FEW DAYS. FORECAST
MODELS DO SHOW CONSIDERABLE SPREAD FROM AROUND 100 DEGREES INTO THE
MID 100`S BOTH DAY AS THE WARM BOUNDARY LAYER PLUME OVERSPREAD THE
AREA WITH 27-30 DEGREES C 850 MB AIR. IF THE WARMEST OF FORECAST
SOLUTIONS VERIFY ACROSS CENTRAL KANSAS, DANGEROUS HEAT INDICES COULD
BE ACHIEVED IN THE AFTERNOON. THE PATTERN BECOMES MORE FLATTENED
AFTER FRIDAY, AND JUST HOW WARM THE HIGHS GET IN THE AFTERNOON ARE
LESS CLEAR. BY MONDAY, THE ECMWF SHOWS A FRONT IN THE VICINITY OF
NORTHWEST KANSAS AND SW NEBRASKA. THAT KIND OF PATTERN WOULD
RELEGATE STORMS TO THE FRONT WITH A LACK OF STEERING FLOW. A RESULT
OF THE NEARLY STATIONARY UPPER HIGH WILL BE SURFACE WINDS BECOMING
MORE LIGHT AND VARIABLE WITH TIME AS THE SUBSIDENCE INDUCED SURFACE
HIGH MAINTAINS INCREASING HIGH PRESSURE FROM THE NORTHERN PLAINS.
LIGHT AND VARIABLE OR LIGHT EASTERLY FLOW WOULD SUPPORT NOT AS HOT
TEMPERATURES IN THE MID TO UPPER 90S AND LOWER FREQUENCIES OF 100
DEGREE AND HIGH READINGS. ISOLATED ELEVATED THUNDERSTORMS CAN`T BE
RULED OUT COMPLETELY MID TO LATE WEEK AS MODELS SHOW A SUBTLE SIGNAL
OF MID LEVEL MOISTURE SPREADING NORTHWARD ON THE BACK SIDES OF THE
UPPER HIGH PRESSURE. CONFIDENCE IS TOO LOW HOWEVER TO RAISE THE
CURRENT ALLBLEND APPROACH OF SINGLE DIGIT PRECIPITATION
PROBABILITIES DURING THIS TIMEFRAME. .
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1244 AM CDT THU JUL 11 2013
IN THE WAKE OF AN OUTFLOW BOUNDARY FROM THUNDERSTORMS IN FAR
WESTERN KANSAS, WINDS AT GCK/DDC WILL BE WESTERLY BETWEEN 06-8Z, THEN
BECOME LIGHT AND VARIABLE OVERNIGHT BEFORE SWITCHING TO THE
SOUTHEAST/SOUTH AT 15 KTS BY 15-17Z. VFR CONDITIONS SHOULD PREVAIL
IN THE ABSENCE OF THUNDERSTORMS AT THE TAF SITES.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 98 73 104 74 / 10 10 0 0
GCK 97 73 104 73 / 20 20 0 0
EHA 99 72 103 71 / 10 10 0 0
LBL 98 72 104 73 / 10 10 0 0
HYS 96 73 104 75 / 20 20 0 0
P28 99 74 102 75 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BURGERT
SHORT TERM...FINCH
LONG TERM...RUSSELL
AVIATION...FINCH
AREA FORECAST DISCUSSION...CORRECTED
NWS WICHITA KS
400 AM CDT THU JUL 11 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 400 AM CDT THU JUL 11 2013
TODAY:
(+)TSRA CLUSTER CONTINUES OVER SW NEBRASKA/NW KS BORDER FROM ~KMCK SE
OVER DECATUR & NORTON COUNTIES. ANOTHER (+)TSRA THAT DEVELOPED OVER
ERN OSBORNE COUNTY IS STATIONARY. TSRA BEING SUSTAINED BY STRONG DEEP
ISENTROPIC ASCENT FROM 305-315K LAYER INDUCED BY BROAD HIGH PRESSURE
COVERING MOST OF UPR MS VALLEY & WEAK LOW PRESSURE SITUATED NEAR CO/KS
BORDER...FROM WHICH A WEAK NEARLY STATIONARY FRONT EXTENDS SE ACROSS
SW KS TO NRN OK. WELL-DEFINED RICH LWR-DECK MOISTURE AXIS IS ORIENTED
IN NW-SE MANNER ALONG & JUST NE OF THE BOUNDARY TO ALONG THE W/SW
CORRIDOR OF KICT COUNTRY. GREATEST CHANCES FOR TSRA TO THEREFORE OCCUR
OVER WRN HALF OF KICT COUNTRY THIS MORNING. HRRR DEPICTING A SIMILAR
PATTERN & AS SUCH HAVE INCREASED POPS TO 35-40% OVER THAT PART OF
CNTRL KS W OF I-135. AS LWR-DECK TROFFING GETS BETTER ESTABLISHED LWR
DECK FLOW TO BECOME MORE SLY WHICH WOULD REALIGN LWR-DECK MOISTURE
AXIS TO N-S ORIENTATION. WITH STRONG MASSIVE MID-UPR HIGH INCREASING
DOMINANCE FROM THE SRN TOWARD THE NRN PLAINS THE RESULTING INCREASED
SUBSIDENCE WOULD INHIBIT FURTHER TSRA DEVELOPMENT THIS AFTERNOON.
THE ALREADY STRONG MASSIVE HIGH PRESSURE BECOMES EVEN MORE SO OVER THE
NEXT 3 DAYS & WITH LWR-DECK TROFFING INCRESING OVER THE WRN PLAINS THE
FURNACE WILL REMAIN TURNED UP THRU SATURDAY. HIGHS ~100F ARE LIKELY
ALONG THE WRN CORRIDOR FRI & SAT WHERE HEAT INDICES ~105F ARE POSSIBLE.
AS SUCH A HEAT ADVISORY MAY BE REQUIRED...ESPECIALLY FRI. STAY TUNED.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU JUL 11 2013
TYPICAL MID-SUMMER STILL ANTICIPATED THROUGHOUT THESE PERIODS. HOWEVER
MID-RANGE MODELS (MORE SO THE GFS) DEPICT A MID-UPR LOW PRESSURE AREA
RETROGRADING ACROSS THE MID-MS VALLEY TOWARD...THEN ACROSS...THE MO/KS
BORDER ON MON. FOR NOW HAVE DRY FORECAST INTACT BUT THE BEHAVIOR OF THE
UNORTHODOX LOW WILL REQUIRE INCREASED ATTENTION LATER THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM CDT WED JUL 10 2013
VFR CONDITIONS WILL CONTINUE ACROSS THE FORECAST AREA FOR THE NEXT
24 HOURS...CONVECTION THAT PREVIOUSLY FIRED ALONG THE THE MAIN SFC
FRONTAL BOUNDARY OVER NRN OK HAS ENDED.
CONVECTION ACROSS EXTREME WRN KS COULD VENTURE E-SE AS THE OVERNIGHT
PROGRESSES...BUT THINK MOST OF THIS CONVECTION WILL WANE AS IT
APPROACHES THE AREA. ALSO THINK THAT ANY CONVECTION THAT SURVIVES
THIS FAR EAST WILL DIVE SOUTHEAST AND MISS THE SOUTH CEN KS TAF
SITES OF KICT/KHUT.
A SMALL CONCERN ABOUT THE SCT CONVECTION CURRENTLY DEVELOPING OVER
SW NEB. FLOW PATTERN WOULD TAKE THIS CONVECTION TOWARDS CEN KS LATE
TONIGHT OR EARLY THU MORNING...IF IT CAN HOLD TOGETHER. NOT SURE
HOW LONG THIS CONVECTION WILL LAST AS IT MAKES PROGRESS TO THE
SOUTHEAST...AS LOW LEVEL MOISTURE SUPPORT ISNT THAT IMPRESSIVE...AND
THIS CONVECTION WILL MOVE INTO THE A MORE STABLE ATMOSPHERE AS IT
MOVES SOUTHEAST. SO WILL NOT ADD ANY TSRA CHANCE INTO THE KRSL OR
KSLN TAFS EARLY ON MON FOR NOW. SHORT RANGE HIGH-RES MODELS BLOW
THIS SCATTERED CONVECTION INTO A COMPLEX OF STORMS AND DROP IT SOUTH
ACROSS THE FORECAST AREA FOR THU AM. THINK THIS IS OVERDONE FOR
REASONS MENTIONED ABOVE.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 97 72 99 77 / 30 0 0 0
HUTCHINSON 96 72 100 77 / 40 0 0 0
NEWTON 94 71 97 76 / 30 0 0 0
ELDORADO 93 71 97 75 / 20 0 0 0
WINFIELD-KWLD 96 73 99 76 / 30 0 0 0
RUSSELL 95 72 102 77 / 40 10 0 0
GREAT BEND 96 73 102 77 / 40 10 0 0
SALINA 93 72 101 77 / 30 10 0 0
MCPHERSON 94 72 100 77 / 40 0 0 0
COFFEYVILLE 92 71 97 73 / 10 0 0 0
CHANUTE 89 69 95 71 / 10 0 0 0
IOLA 90 68 94 71 / 10 0 0 0
PARSONS-KPPF 91 70 95 72 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ES
*CORRECTED TO INCLUDE POTENTIAL FOR HEAT ADVISORY ISSUANCE FOR FRI.*
AREA FORECAST DISCUSSION
NWS WICHITA KS
354 AM CDT THU JUL 11 2013
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 355 AM CDT THU JUL 11 2013
TODAY:
(+)TSRA CLUSTER CONTINUES OVER SW NEBRASKA/NW KS BORDER FROM ~KMCK SE
OVER DECATUR & NORTON COUNTIES. ANOTHER (+)TSRA THAT DEVELOPED OVER
ERN OSBORNE COUNTY IS STATIONARY. TSRA BEING SUSTAINED BY STRONG DEEP
ISENTROPIC ASCENT FROM 305-315K LAYER INDUCED BY BROAD HIGH PRESSURE
COVERING MOST OF UPR MS VALLEY & WEAK LOW PRESSURE SITUATED NEAR CO/KS
BORDER...FROM WHICH A WEAK NEARLY STATIONARY FRONT EXTENDS SE ACROSS
SW KS TO NRN OK. WELL-DEFINED RICH LWR-DECK MOISTURE AXIS IS ORIENTED
IN NW-SE MANNER ALONG & JUST NE OF THE BOUNDARY TO ALONG THE W/SW
CORRIDOR OF KICT COUNTRY. GREATEST CHANCES FOR TSRA TO THEREFORE OCCUR
OVER WRN HALF OF KICT COUNTRY THIS MORNING. HRRR DEPICTING A SIMILAR
PATTERN & AS SUCH HAVE INCREASED POPS TO 35-40% OVER THAT PART OF
CNTRL KS W OF I-135. AS LWR-DECK TROFFING GETS BETTER ESTABLISHED LWR
DECK FLOW TO BECOME MORE SLY WHICH WOULD REALIGN LWR-DECK MOISTURE
AXIS TO N-S ORIENTATION. WITH STRONG MASSIVE MID-UPR HIGH INCREASING
DOMINANCE FROM THE SRN TOWARD THE NRN PLAINS THE RESULTING INCREASED
SUBSIDENCE WOULD INHIBIT FURTHER TSRA DEVELOPMENT THIS AFTERNOON.
THE ALREADY STRONG MASSIVE HIGH PRESSURE BECOMES EVEN MORE SO OVER THE
NEXT 3 DAYS & WITH LWR-DECK TROFFING INCRESING OVER THE WRN PLAINS THE
FURNACE WILL REMAIN TURNED UP THRU SATURDAY. HIGHS ~100F ARE LIKELY
ALONG THE WRN CORRIDOR.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU JUL 11 2013
TYPICAL MID-SUMMER STILL ANTICIPATED THROUGHOUT THESE PERIODS. HOWEVER
MID-RANGE MODELS (MORE SO THE GFS) DEPICT A MID-UPR LOW PRESSURE AREA
RETROGRADING ACROSS THE MID-MS VALLEY TOWARD...THEN ACROSS...THE MO/KS
BORDER ON MON. FOR NOW HAVE DRY FORECAST INTACT BUT THE BEHAVIOR OF THE
UNORTHODOX LOW WILL REQUIRE INCREASED ATTENTION LATER THIS WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1142 PM CDT WED JUL 10 2013
VFR CONDITIONS WILL CONTINUE ACROSS THE FORECAST AREA FOR THE NEXT
24 HOURS...CONVECTION THAT PREVIOUSLY FIRED ALONG THE THE MAIN SFC
FRONTAL BOUNDARY OVER NRN OK HAS ENDED.
CONVECTION ACROSS EXTREME WRN KS COULD VENTURE E-SE AS THE OVERNIGHT
PROGRESSES...BUT THINK MOST OF THIS CONVECTION WILL WANE AS IT
APPROACHES THE AREA. ALSO THINK THAT ANY CONVECTION THAT SURVIVES
THIS FAR EAST WILL DIVE SOUTHEAST AND MISS THE SOUTH CEN KS TAF
SITES OF KICT/KHUT.
A SMALL CONCERN ABOUT THE SCT CONVECTION CURRENTLY DEVELOPING OVER
SW NEB. FLOW PATTERN WOULD TAKE THIS CONVECTION TOWARDS CEN KS LATE
TONIGHT OR EARLY THU MORNING...IF IT CAN HOLD TOGETHER. NOT SURE
HOW LONG THIS CONVECTION WILL LAST AS IT MAKES PROGRESS TO THE
SOUTHEAST...AS LOW LEVEL MOISTURE SUPPORT ISNT THAT IMPRESSIVE...AND
THIS CONVECTION WILL MOVE INTO THE A MORE STABLE ATMOSPHERE AS IT
MOVES SOUTHEAST. SO WILL NOT ADD ANY TSRA CHANCE INTO THE KRSL OR
KSLN TAFS EARLY ON MON FOR NOW. SHORT RANGE HIGH-RES MODELS BLOW
THIS SCATTERED CONVECTION INTO A COMPLEX OF STORMS AND DROP IT SOUTH
ACROSS THE FORECAST AREA FOR THU AM. THINK THIS IS OVERDONE FOR
REASONS MENTIONED ABOVE.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 97 72 99 77 / 30 0 0 0
HUTCHINSON 96 72 100 77 / 40 0 0 0
NEWTON 94 71 97 76 / 30 0 0 0
ELDORADO 93 71 97 75 / 20 0 0 0
WINFIELD-KWLD 96 73 99 76 / 30 0 0 0
RUSSELL 95 72 102 77 / 40 10 0 0
GREAT BEND 96 73 102 77 / 40 10 0 0
SALINA 93 72 101 77 / 30 10 0 0
MCPHERSON 94 72 100 77 / 40 0 0 0
COFFEYVILLE 92 71 97 73 / 10 0 0 0
CHANUTE 89 69 95 71 / 10 0 0 0
IOLA 90 68 94 71 / 10 0 0 0
PARSONS-KPPF 91 70 95 72 / 10 0 0 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ES
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
145 PM EDT THU JUL 11 2013
.UPDATE...
ISSUED AT 140 PM EDT THU JUL 11 2013
SOME STRAY CONVECTION LINGERS OVER SOUTHEASTERN KY WITH A BROKEN LINE
OF MAINLY JUST SHOWERS FROM PARTS OF SOUTHEAST OH INTO NORTH CENTRAL
KY. THERE HAS BEEN NO LIGHTNING WITH THIS SO FAR. HOWEVER...COVERAGE
OF THIS MAY INCREASE A LITTLE AS WE REACH PEAK HEATING COMBINED WITH
THE BOUNDARY SLOWLY SAGGING SOUTH ACROSS THE AREA. A FEW SLIGHT
ADJUSTMENTS WERE MADE BASED ON RADAR AND OBSERVATIONS...BUT NO MAJOR
CHANGES WERE NEEDED AT THIS TIME.
UPDATE ISSUED AT 1025 AM EDT THU JUL 11 2013
A COLD FRONT CONTINUES TO SAG SOUTH AND EAST ACROSS THE OH VALLEY
REGION AND EASTERN KY. THERE IS MAINLY LOW CLOUDS AND STRATUS LEFT
FROM EARLIER FOG AND RECENT RADAR IMAGERY SUGGESTS SOME SPRINKLES OR
LIGHT SHOWERS AND SOME DRIZZLE WITH THIS ATTM. RECENT 12Z NAM
GUIDANCE AS WELL AS THE 9Z SREF SUGGEST THE POTENTIAL FOR SOME MAINLY
AFTERNOON CONVECTION IN THE SOUTHEAST CWA. THE HRRR HAS SOME
CONVECTIVE ACTIVITY AS WELL...BUT SEEMS TO HAVE IT TOO FAR TO THE
NORTHWEST.
OVERALL...PERSISTENCE AND RECENT MODEL GUIDANCE SUGGESTS THAT
ISOLATED TO SCATTERED SHRA/TSRA ARE POSSIBLE DURING PEAK HEATING
TODAY AS THE BOUNDARY SLOWLY SAGS SOUTHEAST TOWARD THE VA BORDER.
OTHER THAN FRESHENING UP THE FORECAST BASED ON RECENT OBSERVATIONS...
NO SIGNIFICANT CHANGES WERE MADE.
UPDATE ISSUED AT 737 AM EDT THU JUL 11 2013
BASED ON AMOUNT OF FOG ACROSS MUCH OF THE AREA...UPDATED TO INCLUDE
DENSE FOG WORDING IN THE GRIDS. WITH LLVL INVERSION AND FOG STILL IN
PLACE...THERE HAS BEEN NO CONVECTIVE DEVELOPMENT SO FAR THIS MORNING.
SOME ISL/SCT SHOWERS ARE STILL POSSIBLE AS THE FRONT PASSES THROUGH
LATE THIS MORNING/EARLY THIS AFTERNOON...BUT SO LONG AS FOG AND
INVERSION ARE IN PLACE...POPS WILL BE LIMITED. WENT AHEAD AND BUMPED
DOWN POPS SLIGHTLY TO TAKE OUT ONGOING SCT WORDING THIS
MORNING...WITH BETTER CHANCES MOVING IN FROM PIKE TO MCCREARY COUNTY
OVER THE NEXT FEW HOURS HOPEFULLY AS FOG AND INVERSION BEGIN TO LIFT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 340 AM EDT THU JUL 11 2013
AFTER A VERY EVENTFUL WEEK...IT SEEMS AS THOUGH QUIETER AND NICER
WEATHER IS FINALLY IN STORE. COLD FRONT WILL CONTINUE TO PUSH
THROUGH SE KY THIS MORNING...BUT MAIN AREA OF CONVECTION AHEAD OF
THE FRONT HAS MOVED OUT OF THE REGION WITH AN ABUNDANT AMOUNT OF
DRY AIR NOW FILTERING IN. A FEW ISOLATED SHALLOW AND SHORT LIVED
SHOWERS COULD BE POSSIBLE AS THE FRONT PASSES THROUGH IN THE LATE
MORNING/EARLY AFTERNOON...BUT LITTLE IS EXPECTED FOR IMPACTS. BACKED
OFF ON POPS BOTH FOR THE OVERNIGHT LAST NIGHT AND INTO THE DAY TODAY
AS A RESULT. MAIN CONCERN RIGHT NOW IS THE FACT THAT DESPITE ALL OF
THIS DRY AIR IN PLACE...RAIN THAT TRAVERSED THE REGION YESTERDAY HAS
LED TO VERY MOIST LLVLS TRAPPED BELOW A NEAR SURFACE INVERSION. AS A
RESULT...FAIRLY DENSE AND WIDESPREAD FOG STARTED FORMING LAST
NIGHT...AND WILL CONTINUE THROUGHOUT THE MORNING HOURS BEFORE SURFACE
INVERSION CLIMBS A LITTLE HIGHER UP IN THE ATMOSPHERE. AT THIS
POINT...FOG WILL LIFT INTO A LLVL STRATUS DECK AND
THEN EVENTUALLY A BROKEN CU DECK BEFORE IT SCATTERS OFF IN THE
EVENING. IT IS ALSO IN THIS LAYER THAT WE WILL SEE OUR BEST
POTENTIAL FOR ANY ABOVE MENTIONED LIGHT CONVECTIVE DEVELOPMENT. IN
GOOD NEWS...THIS DECK WILL BE FAIRLY SHALLOW WITH THE POTENTIAL TO
BREAK DOWN EVEN SOONER VIA ANY DAYTIME MODIFICATION TO THE SOUNDING.
OTHERWISE...PLAN ON GREAT WEATHER TODAY. HIGH TEMPERATURES WILL
BE BELOW NORMAL ACROSS THE REGION...REACHING NEAR 80 IN MOST
LOCATIONS WITH WINDS COMING FROM A NRLY DIRECTION. AND WITH A DRIER
CONTINENTAL AIRMASS IN PLACE...EXPECT HUMIDITY LEVELS TO BE MUCH
LOWER THAN PREVIOUS DAYS. THE SAME WILL CARRY OVER INTO THE
OVERNIGHT HOURS AND INTO THE DAY TOMORROW. SOME PATCHY FOG WILL BE
POSSIBLE OVERNIGHT TONIGHT...BUT SHOULD MAINLY BE LIGHT AND CONFINED
TO THE EXTREME VALLEYS WHERE INVERSION IS MORE LIKELY TO SET UP. DRY
AIRMASS WILL PREVENT A REPEAT FROM LAST NIGHT/THIS MORNING.
OTHERWISE...ENJOY. HIGH PRESSURE AND DRY/MILD WEATHER SHOULD CARRY
OVER INTO THE WEEKEND.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU JUL 11 2013
THERE IS STILL GOOD AGREEMENT IN THE MODELS EARLY ON...BUT NOT FAR
INTO THE PERIOD THEIR SOLUTIONS BEGIN TO DIVERGE. THE ELEMENT IN
DISPUTE IS AN UPPER LOW WHICH WILL BE LEFT BEHIND BY THE TROUGH
CURRENTLY DROPPING INTO THE EASTERN CONUS. MODELS DO AGREE ON A
CLOSED LOW BEING PINCHED OFF NEAR THE WV/MD BORDER BY FRIDAY
EVENING. THIS LOW THEN RETROGRADES...BUT EXACTLY WHERE IT GOES AND
HOW FAST IT MOVES ARE IN QUESTION. WITHOUT A CLEAR PREFERENCE...WILL
USE A BLENDED MODEL SOLUTION.
AT THE SURFACE...OUR INITIAL AIR MASS WILL BE DRY...HAVING BEEN
SUPPLIED BY HIGH PRESSURE OVER THE GREAT LAKES. THIS HIGH WILL
WEAKEN AND SUBTROPICAL HIGH PRESSURE OVER THE ATLANTIC WILL BECOME
MORE DOMINANT. IT WILL SEND A MORE HUMID AIR MASS BACK NORTHWEST
OVER THE LOCAL AREA...UNDERNEATH THE WEAK TROUGH OR UPPER LOW LEFT
BEHIND. THIS WILL RESULT IN A POSSIBILITY OF SHOWERS/THUNDERSTORMS
BY LATE SATURDAY NIGHT OR SUNDAY. THE BEST CHANCE WILL BE MONDAY AND
TUESDAY. BY WEDNESDAY...MODELS SHOW WHAT IS LEFT OF THE UPPER LOW TO
BE WELL TO OUR WEST OR SOUTHWEST...WITH UPPER LEVEL RIDGING BUILDING
OVER THE OHIO VALLEY...CUTTING INTO POPS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 140 PM EDT THU JUL 11 2013
WITH STRONG JULY SUNSHINE AND A BOUNDARY DROPPING SOUTHEAST ACROSS
THE REGION...EARLIER STRATUS HAS LIFTED INTO CU. A FEW ISOLATED
SHOWERS HAVE DEVELOPED CLOSER TO THE OH RIVER. COVERAGE OF THESE
SHOULD INCREASE THROUGH 20Z. THE CONVECTION SHOULD BEGIN TO WANE BY
0Z WITH THE CU MIXING OUT AS THE BOUNDARY MOVES FURTHER SOUTH AND
DAYTIME HEATING IS LOST. BEHIND THE BOUNDARY...A DRIER AIRMASS WILL
BE MOVING INTO THE REGION...BUT DRYING WILL BE SLOWER NEARER TO THE
VA AND TN BORDERS. LAMP GUIDANCE IS HITTING THE FOG RATHER HARD BUT
MOS GUIDANCE IS NOT QUITE AS PESSIMISTIC. WITH THIS ISSUANCE...OPTED TO
INSERT FOG INTO THE TAFS AT LOZ AND SME WHERE FOG COULD REDUCE VIS
BELOW AIRPORT MINS BETWEEN 8Z AND ABOUT 13Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JMW
LONG TERM...HAL
AVIATION...JP
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1028 AM EDT THU JUL 11 2013
.UPDATE...
ISSUED AT 1025 AM EDT THU JUL 11 2013
A COLD FRONT CONTINUES TO SAG SOUTH AND EAST ACROSS THE OH VALLEY
REGION AND EASTERN KY. THERE IS MAINLY LOW CLOUDS AND STRATUS LEFT
FROM EARLIER FOG AND RECENT RADAR IMAGERY SUGGESTS SOME SPRINKLES OR
LIGHT SHOWERS AND SOME DRIZZLE WITH THIS ATTM. RECENT 12Z NAM
GUIDANCE AS WELL AS THE 9Z SREF SUGGEST THE POTENTIAL FOR SOME MAINLY
AFTERNOON CONVECTION IN THE SOUTHEAST CWA. THE HRRR HAS SOME
CONVECTIVE ACTIVITY AS WELL...BUT SEEMS TO HAVE IT TOO FAR TO THE
NORTHWEST.
OVERALL...PERSISTENCE AND RECENT MODEL GUIDANCE SUGGESTS THAT
ISOLATED TO SCATTERED SHRA/TSRA ARE POSSIBLE DURING PEAK HEATING
TODAY AS THE BOUNDARY SLOWLY SAGS SOUTHEAST TOWARD THE VA BORDER.
OTHER THAN FRESHENING UP THE FORECAST BASED ON RECENT OBSERVATIONS...
NO SIGNIFICANT CHANGES WERE MADE.
UPDATE ISSUED AT 737 AM EDT THU JUL 11 2013
BASED ON AMOUNT OF FOG ACROSS MUCH OF THE AREA...UPDATED TO INCLUDE
DENSE FOG WORDING IN THE GRIDS. WITH LLVL INVERSION AND FOG STILL IN
PLACE...THERE HAS BEEN NO CONVECTIVE DEVELOPMENT SO FAR THIS MORNING.
SOME ISL/SCT SHOWERS ARE STILL POSSIBLE AS THE FRONT PASSES THROUGH
LATE THIS MORNING/EARLY THIS AFTERNOON...BUT SO LONG AS FOG AND
INVERSION ARE IN PLACE...POPS WILL BE LIMITED. WENT AHEAD AND BUMPED
DOWN POPS SLIGHTLY TO TAKE OUT ONGOING SCT WORDING THIS
MORNING...WITH BETTER CHANCES MOVING IN FROM PIKE TO MCCREARY COUNTY
OVER THE NEXT FEW HOURS HOPEFULLY AS FOG AND INVERSION BEGIN TO LIFT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 340 AM EDT THU JUL 11 2013
AFTER A VERY EVENTFUL WEEK...IT SEEMS AS THOUGH QUIETER AND NICER
WEATHER IS FINALLY IN STORE. COLD FRONT WILL CONTINUE TO PUSH
THROUGH SE KY THIS MORNING...BUT MAIN AREA OF CONVECTION AHEAD OF
THE FRONT HAS MOVED OUT OF THE REGION WITH AN ABUNDANT AMOUNT OF
DRY AIR NOW FILTERING IN. A FEW ISOLATED SHALLOW AND SHORT LIVED
SHOWERS COULD BE POSSIBLE AS THE FRONT PASSES THROUGH IN THE LATE
MORNING/EARLY AFTERNOON...BUT LITTLE IS EXPECTED FOR IMPACTS. BACKED
OFF ON POPS BOTH FOR THE OVERNIGHT LAST NIGHT AND INTO THE DAY TODAY
AS A RESULT. MAIN CONCERN RIGHT NOW IS THE FACT THAT DESPITE ALL OF
THIS DRY AIR IN PLACE...RAIN THAT TRAVERSED THE REGION YESTERDAY HAS
LED TO VERY MOIST LLVLS TRAPPED BELOW A NEAR SURFACE INVERSION. AS A
RESULT...FAIRLY DENSE AND WIDESPREAD FOG STARTED FORMING LAST
NIGHT...AND WILL CONTINUE THROUGHOUT THE MORNING HOURS BEFORE SURFACE
INVERSION CLIMBS A LITTLE HIGHER UP IN THE ATMOSPHERE. AT THIS
POINT...FOG WILL LIFT INTO A LLVL STRATUS DECK AND
THEN EVENTUALLY A BROKEN CU DECK BEFORE IT SCATTERS OFF IN THE
EVENING. IT IS ALSO IN THIS LAYER THAT WE WILL SEE OUR BEST
POTENTIAL FOR ANY ABOVE MENTIONED LIGHT CONVECTIVE DEVELOPMENT. IN
GOOD NEWS...THIS DECK WILL BE FAIRLY SHALLOW WITH THE POTENTIAL TO
BREAK DOWN EVEN SOONER VIA ANY DAYTIME MODIFICATION TO THE SOUNDING.
OTHERWISE...PLAN ON GREAT WEATHER TODAY. HIGH TEMPERATURES WILL
BE BELOW NORMAL ACROSS THE REGION...REACHING NEAR 80 IN MOST
LOCATIONS WITH WINDS COMING FROM A NRLY DIRECTION. AND WITH A DRIER
CONTINENTAL AIRMASS IN PLACE...EXPECT HUMIDITY LEVELS TO BE MUCH
LOWER THAN PREVIOUS DAYS. THE SAME WILL CARRY OVER INTO THE
OVERNIGHT HOURS AND INTO THE DAY TOMORROW. SOME PATCHY FOG WILL BE
POSSIBLE OVERNIGHT TONIGHT...BUT SHOULD MAINLY BE LIGHT AND CONFINED
TO THE EXTREME VALLEYS WHERE INVERSION IS MORE LIKELY TO SET UP. DRY
AIRMASS WILL PREVENT A REPEAT FROM LAST NIGHT/THIS MORNING.
OTHERWISE...ENJOY. HIGH PRESSURE AND DRY/MILD WEATHER SHOULD CARRY
OVER INTO THE WEEKEND.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 340 AM EDT THU JUL 11 2013
THERE IS STILL GOOD AGREEMENT IN THE MODELS EARLY ON...BUT NOT FAR
INTO THE PERIOD THEIR SOLUTIONS BEGIN TO DIVERGE. THE ELEMENT IN
DISPUTE IS AN UPPER LOW WHICH WILL BE LEFT BEHIND BY THE TROUGH
CURRENTLY DROPPING INTO THE EASTERN CONUS. MODELS DO AGREE ON A
CLOSED LOW BEING PINCHED OFF NEAR THE WV/MD BORDER BY FRIDAY
EVENING. THIS LOW THEN RETROGRADES...BUT EXACTLY WHERE IT GOES AND
HOW FAST IT MOVES ARE IN QUESTION. WITHOUT A CLEAR PREFERENCE...WILL
USE A BLENDED MODEL SOLUTION.
AT THE SURFACE...OUR INITIAL AIR MASS WILL BE DRY...HAVING BEEN
SUPPLIED BY HIGH PRESSURE OVER THE GREAT LAKES. THIS HIGH WILL
WEAKEN AND SUBTROPICAL HIGH PRESSURE OVER THE ATLANTIC WILL BECOME
MORE DOMINANT. IT WILL SEND A MORE HUMID AIR MASS BACK NORTHWEST
OVER THE LOCAL AREA...UNDERNEATH THE WEAK TROUGH OR UPPER LOW LEFT
BEHIND. THIS WILL RESULT IN A POSSIBILITY OF SHOWERS/THUNDERSTORMS
BY LATE SATURDAY NIGHT OR SUNDAY. THE BEST CHANCE WILL BE MONDAY AND
TUESDAY. BY WEDNESDAY...MODELS SHOW WHAT IS LEFT OF THE UPPER LOW TO
BE WELL TO OUR WEST OR SOUTHWEST...WITH UPPER LEVEL RIDGING BUILDING
OVER THE OHIO VALLEY...CUTTING INTO POPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 704 AM EDT THU JUL 11 2013
A LINE OF SHOWERS AND THUNDERSTORMS MOVED THROUGH THE AREA YESTERDAY
AFTERNOON/EVENING AHEAD OF AN APPROACHING SURFACE COLD FRONT...BEFORE
EXITING THE REGION BY LATE EVENING. AS SUCH...DRY AIR HAS NOW
FILTERED IN BEHIND THE CONVECTION...BUT A LLVL INVERSION THAT
DEVELOPED OVERNIGHT HAS TRAPPED A LARGE AMOUNT OF MOISTURE NEAR THE
SURFACE. THIS HAS CAUSED FOG TO DEVELOP AND AFFECT MUCH OF THE
REGION...INCLUDING ALL THREE TAF SITES...CAUSING THEM TO FALL BELOW
AIRPORT MINIMUMS. FORECAST SOUNDINGS POINT AT THIS FOG STICKING
AROUND THROUGH MID MORNING...THEN AS SURFACE FRONT APPROACHES...BEST
MOISTURE WILL LIFT FROM THE SURFACE TO CREATE A LLVL STRATUS DECK AND
THEN EVENTUALLY A BROKEN CU DECK BEFORE IT SCATTERS OFF IN THE
EVENING. DRY AIRMASS IN PLACE THIS AFTERNOON AND TONIGHT SHOULD
PREVENT ANY WIDESPREAD DEVELOPMENT OF FOG...SO DO NOT EXPECT ANY
IMPACTS AT TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...JMW
LONG TERM...HAL
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS JACKSON KY
218 AM EDT THU JUL 11 2013
.UPDATE...
ISSUED AT 217 AM EDT THU JUL 11 2013
DRY AIR CONTINUES TO FILTER IN ACROSS THE REGION...AND WITH LLVL
INVERSION IN PLACE...ANY PRECIP NEAR THE REGION HAS ALL BUT DIED OUT.
THIS INCLUDES THE LINE OF PRECIP THAT WAS RIDING ALONG THE FRONT TO
OUR NORTH EARLIER IN THE EVENING. AS A RESULT...BUMPED POPS DOWN
TONIGHT AND THROUGH MUCH OF THE DAY TOMORROW. ANY CONVECTION THAT
DEVELOPS WILL BE ISOLATED ACROSS MUCH OF THE REGION...WITH THE BEST
CHANCES OF SCT CONVECTION IN THE FAR SE AS THE SURFACE FRONT GOES
THROUGH THIS MORNING/EARLY AFTERNOON /AIDED BY SOME DAYTIME HEATING/.
UPDATE ISSUED AT 945 PM EDT WED JUL 10 2013
THUNDERSTORMS ARE OVER AND SHOWERS ARE DIMINISHING. PCPN HAS BECOME
MORE SCT IN NATURE AND WILL REDUCE POPS FOR THE OVERNIGHT. COLD FRONT
STILL PRESSING TO THE SE ACROSS THE OHIO RIVER BUT IT IS INDICATED BY
A THIN LINE OF WIDELY DISPERSED CONVECTION. TEMPS ON TRACK BUT THE
FOG IS MORE WIDESPREAD THAN PREVIOUS FCST AND IS EVEN SOME LOW
STRATUS AT JKL REDUCING CIG AND VSBY.
UPDATE ISSUED AT 710 PM EDT WED JUL 10 2013
THUNDERSTORMS HAVE DIMINISHED IN INTENSITY AND COVERAGE. HEAVY RAIN
IS OVER AND WILL ELIMINATE BOTH THE SVR THUNDERSTORM WATCH 407 AND
THE FLASH FLOOD WATCH.
UPDATE ISSUED AT 600 PM EDT WED JUL 10 2013
HAVE HAD ONLY 1 REPORT OF WIND DAMAGE SO FAR...AND SEVERE THREAT IS
DIMINISHING. WILL BE UPDATING NDFD FOR LATEST OBSERVATIONAL TRENDS
AND FOR CURRENT MOVEMENT OF SHOWERS AND THUNDERSTORMS ACROSS THE
FORECAST AREA. PLAN TO BEGIN TRIMMING COUNTIES FROM THE SEVERE
THUNDERSTORM WATCH ON THE WESTERN PART OF THE FORECAST AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 304 PM EDT WED JUL 10 2013
WILL ADD PIKE...LETCHER AND HARLAN COUNTY TO FLASH FLOOD WATCH.
WITH CONVECTION IN THESE AREAS ALREADY OCCURRING TODAY...THEY WILL BE
PRIMED FOR POTENTIAL FLASH FLOODING WITH ADDITIONAL ACTIVITY THIS
EVENING AND OVERNIGHT. COLD FRONT CURRENTLY IN NORTHWEST INDIANA WILL
BE ONLY SLOWLY PRESSING SOUTHEAST OVERNIGHT AND NOT CLEARING
SOUTHEAST KY UNTIL THURSDAY AFTERNOON. LATEST MODEL GUIDANCE AND
ESPECIALLY CURRENT RADAR TRENDS POINTING TOWARDS MULTIPLE ROUNDS OF
SHOWERS AND THUNDERSTORMS FROM LATE THIS AFTERNOON INTO TONIGHT.
PRECIPITABLE WATER AROUND 1.8 THIS AFTERNOON AND WILL NOT SEE MUCH
DECREASE UNTIL AFTER FRONTAL PASSAGE ON THURSDAY...AND THUNDERSTORMS
WILL CONTINUE TO BE CAPABLE OF PRODUCING VERY HEAVY RAIN.
CONSIDERABLE DESTABILIZATION HAS OCCURRED THIS AFTERNOON AND SEVERE
THREAT ALSO INCREASING...WITH SEVERE REPORTS ALREADY OCCURRING IN
CENTRAL KY. HRRR IS POINTING TOWARDS ACTIVITY OVER CENTRAL KY MERGING
INTO A BOWING LINE WHICH WOULD INCREASE SEVERE THREAT OVER SE KY
EARLY THIS EVENING.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 334 PM EDT WED JUL 10 2013
THERE IS DECENT AGREEMENT WITH THE VARIOUS MODELS HOWEVER THERE IS
SOME CONCERN WITH THE RESIDUAL UPPER TROUGH THAT DOES NOT WANT TO GO
AWAY. THE MODELS ARE SHOWING THE UPPER TROUGH INITIALLY MOVING TO
THE EAST. THIS WILL BRING SOME DRIER AND COOLER AIR TO THE AREA FOR
A WHILE...BUT THEN THE MODELS SHOW THE REMNANTS OF THE UPPER LOW OVER
OHIO ON SUNDAY. THE LOW THEN MEANDERS SOUTH OVER TIME. WITH ALL THE
SOLUTIONS...ALL THE FRONTS WILL STAY NORTH OF THE AREA AND EASTERN
KENTUCKY WILL JUST BE GENERAL AIR MASS CONVECTIVE ACTIVITY AND WILL
BE FAIRLY WARM AND HUMID. THE CONFIDENCE TENDS TO GO DOWN AFTER
SUNDAY FOR THE REST OF THE PERIOD BECAUSE IT WILL BE SO HARD TO TELL
WHERE THE AREAS OF ORGANIZED CONVECTION WILL BE. IN GENERAL WENT WITH
A MODEL BLEND...HOWEVER DID AN EXTRA NUDGE TOWARD THE ECMWF. FOR
TEMPERATURES...WENT A BIT COOLER THAN THE MODEL BLEND FOR THE SUNDAY
THROUGH WEDNESDAY TIME FRAME STAYING CLOSER TO THE ECMWF RAW OUTPUT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 217 AM EDT THU JUL 11 2013
A LINE OF SHOWERS AND THUNDERSTORMS MOVED THROUGH THE AREA YESTERDAY
AFTERNOON/EVENING AHEAD OF AN APPROACHING SURFACE COLD FRONT...BEFORE
EXITING THE REGION BY LATE EVENING. AS SUCH...DRY AIR HAS NOW
FILTERED IN BEHIND THE CONVECTION...BUT A LLVL INVERSION THAT HAS
DEVELOPED HAS TRAPPED A LARGE AMOUNT OF MOISTURE NEAR THE SURFACE.
THIS HAS CAUSED FOG TO DEVELOP AND AFFECT MUCH OF THE
REGION...INCLUDING ALL THREE TAF SITES...CAUSING THEM TO FALL BELOW
AIRPORT MINIMUMS. FORECAST SOUNDINGS POINT AT THIS FOG STICKING
AROUND THROUGH MORNING...THEN AS SURFACE FRONT APPROACHES...BEST
MOISTURE WILL LIFT FROM THE SURFACE TO CREATE A LLVL STRATUS DECK AND
THEN EVENTUALLY A BROKEN CU DECK BEFORE IT SCATTERS OFF IN THE
EVENING. DRY AIRMASS IN PLACE SHOULD PREVENT ANY REDEVELOPMENT OF FOG
OVERNIGHT TOMROROW NIGHT...THOUGH IF A SHOWER DOES IN FACT DEVELOP
AND COME IN CONTACT WITH A TAF SITE...MOISTURE LEFT OVER COULD MODIFY
THE LLVLS AND SOME PATCHY FOG COULD DEVELOP.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JMW
SHORT TERM...SBH
LONG TERM...JJ
AVIATION...JMW
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1004 PM EDT FRI JUL 12 2013
.SYNOPSIS...
COLD FRONT HAS STALLED ALONG THE COAST AND WILL REMAIN OVER THE
REGION THROUGH SATURDAY. HIGH PRESSURE WILL BUILD INTO THE REGION
FROM THE EAST THIS WEEKEND AS THE FRONT DISSIPATES OVER THE AREA.
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THE LATEST WATER VAPOR IMAGERY INDICATES AN UPPER LOW CENTER NOW
DROPPING SSW OVER THE APPALACHIAN PLATEAU AS UPPER RIDGING
ENHANCES OVER THE WESTERN ATLANTIC. AT THE SURFACE...A 1014MB
SURFACE LOW IS SITUATED OVER DE PER MSAS ANALYSIS...WITH A TROUGH
AXIS/OLD COLD FRONT EXTENDING SSW ALONG THE COASTAL PLAIN. MUCH
OF THE AREA IS NOW RAIN-FREE ASIDE FROM SOME SCATTERED SHOWERS
OVER THE CHESAPEAKE BAY...PENINSULA...AND MIDDLE PENINSULA. GIVEN
THIS...THE FLASH FLOOD WATCH HAS BEEN CANCELLED FOR ALL THE LOCAL
AREA. THE LATEST HRRR INDICATES THE AFOREMENTIONED SHOWERS SHOULD
DISSIPATE SHORTLY AFTER MIDNIGHT...WITH ADDITIONAL SHOWERS
DEVELOPING OVER NE NC/EXTREME SE VA LATE TONIGHT/EARLY SATURDAY
MORNING AS SE FLOW RECOVERS AS THE TROUGH RETROGRADES WEST. THIS
FLOW PATTERN COULD ALSO TRIGGER SOME SHOWERS OVER THE PIEDMONT
LATER TONIGHT. OVERALL POPS SHOULD REMAIN ON THE LOW SIDE...30-40
PERCENT FOR THE AFOREMENTIONED AREAS...WITH 20 POPS ELSEWHERE.
WARM AND HUMID CONDITIONS WILL CONTINUE WITH TEMPERATURES EXPECTED
TO FALL INTO THE UPPER 60S/LOW 70S TONIGHT UNDER AN OVERCAST SKY.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
MODELS CONTINUE TO HANDLE THE MID/UPPER LEVEL PATTERN WELL
THROUGH THE SHORT TERM. THE UPPER LOW WILL BECOME CUT OFF FROM THE
FLOW TONIGHT/SAT MORNING...AS HIGH PRESSURE STRENGTHENS OVER THE
CNTRL CONUS. THE LOW IS THEN PROGGED TO UNDERCUT THE
RIDGE...PROGRESSING SWWD THROUGH THE SHORT TERM TOWARD THE SRN
PLAINS. THIS WILL ALLOW UPPER/SFC HIGH PRESSURE TO BUILD INTO THE
REGION SAT...AND REMAINING CENTERED OVER THE OH VALLEY THROUGH THE
SHORT TERM. THE RESULT OVER THE LOCAL AREA WILL BE SUMMER LIKE
CONDITIONS WITH THE STORM TRACK REMAINING WELL TO THE NORTH OF THE
REGION. MOISTURE PLUME WILL MOVE INLAND AS UPPER LEVEL FLOW
BECOMES SELY SAT...WITH BEST POPS ACROSS THE PIEDMONT SAT
AFTERNOON. WHILE FORCING FOR ASCENT WILL BE SUBTLE...DIURNAL
FORCING AND ABUNDANT MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SAT AFTERNOON...WEST OF INTERSTATE 95. WILL KEEP
MENTION OF SLIGHT CHANCE POPS FOR THE PIEDMONT SUN AFTERNOON...BUT
BEST MOISTURE/DYNAMICS LOOKS TO BE WEST OF THE AREA. AREA WILL BE
UNDER THE INFLUENCE OF HIGH PRESSURE MON...BUT DO EXPECT MOISTURE
TO ADVECT FROM THE WRN ATLANTIC INTO THE REGION. PRESENCE OF A
WEAK LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES UNDER WEAK FLOW
ALOFT...MAY RESULT IN ISOLATED-WIDELY SCATTERED THUNDERSTORMS
ACROSS THE LOCAL AREA. WILL MAINTAIN SLIGHT CHANCE POPS DURING THE
AFTERNOON FOR DIURNAL FORCING.
NEAR SEASONABLE NORMAL TEMPS SAT UNDER CLEARING SKIES FROM E TO
W. WARMING TREND WILL COMMENCE SUN AS STRONG HEIGHT RISES AND
INCREASING LOW LEVEL THICKNESS VALUES PUSH TEMPS INTO THE LOW 90S.
HOWEVER...SE FLOW WILL PREVENT TEMPS FROM REACHING THEIR FULL
POTENTIAL (HIGHS GENERALLY IN THE LOW 90S). SLIGHTLY WARMER MONDAY
AS WINDS BECOME MORE SLY (HIGHS IN THE LOW 90S). TEMPS ALONG THE
COAST DURING THE SHORT TERM WILL BE SLIGHTLY COOLER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HOTTER AND DRIER WEATHER EXPECTED NEXT WEEK...
MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG H5 RIDGE (599DM)
RESIDING OVER THE OHIO VALLEY TUESDAY/WEDNESDAY OF NEXT WEEK. THE
RIDGE THEN SLOWLY SHIFTS EAST OVER THE MID-ATLANTIC REGION THURSDAY
BEFORE MOVING EAST TO OFF THE CAROLINA COAST BY NEXT FRIDAY. THE
POSITION AND STRENGTH OF THIS RIDGE POINTS TO A SPELL OF HOT WEATHER
ACROSS THE LOCAL AREA NEXT WEEK WITH MAX TEMPS RUNNING ABOUT 1
STANDARD DEVIATION ABOVE NORMAL (MID 90S). THIS STAGNANT AIRMASS
WILL ALSO RESULT IN WARM/MUGGY NIGHTS WITH LOWS IN THE MID/UPR 70S.
LITTLE OPPORTUNITY FOR PCPN WILL OCCUR IN THIS PATTERN AS WELL
OUTSIDE OF ISOLD CONVECTION OVER THE HIGHER TERRAIN TO OUR WEST OUR
ALONG THE AFTN SEA BREEZE. WILL GO NO HIGHER THAN SLIGHT CHC (20%)
POPS THROUGH THE PERIOD.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
A WEAK STNRY FRONT LINGERS OVER EASTERN VA AND NC WITH SHOWERS
CONTINUING TO DEVELOP OVER THE BAY AND RIVERS. SHOWERS SHOULD
AVOID THE TAF SITES THIS EVENING THOUGH REMAIN IN THE VCTY OF ORF
AND PHF THROUGH 03Z. THE FRONT HAS MADE SFC WINDS SOMEWHAT
VARIABLE THIS EVENING WITH WEAK NLY WINDS AT RIC AND SBY WHILE
STATION OVER SE VA AND NE NC REMAIN SLY. WIND WILL RETURN A SLY
DIRECTION AT RIC AND SBY OVERNIGHT. GIVEN THE AMOUNT OF LOW LEVEL
MOISTURE FROM RECENT RAINS...LIGHT WINDS AND PROXIMITY OF THE
FRONT SOME GUIDANCE SUGGEST A PERIOD OF IFR CEILINGS AT MOST TAF
SITES ANYWHERE FROM 03Z-15Z. FOR THE MOST PART HAVE LIMITED IFR
CEILING TO A PERIOD AFTER 06Z TO JUST AFTER 12Z. HEATING AND
MIXING WILL GRADUALLY ERODE IFR CEILINGS THROUGH MID MORNING WITH
A CONTINUOUS BKN030-040 THROUGH THE AFTERNOON. SCATTERED SHOWERS
AND ISOLATED TSTMS SAT AFTERNOON WILL DEPEND ON FRONT AS IT WASHES
OUT AND MOVES WEST. SCATTERED SHOWERS SATURDAY WILL END FROM EAST
TO WEST AS THE BERMUDA HIGH BEGINS TO BUILD BACK IN FROM OFFSHORE
LATER IN THE DAY.
&&
.MARINE...
NO HEADLINES EXPECTED THRU AT LEAST THIS WEEKEND. A FRONTAL BOUNDARY
WILL REMAIN STALLED OVER THE DELMARVA INTO SE VA THROUGH SAT BEFORE
DISSIPATING LATE IN THE DAY. WINDS HAVE BEEN SOMEWHAT VARIABLE
THIS EVENING BECOMING NLY OVER THE MIDDLE AND UPPER BAY. FORECAST
UPDATE REFLECTED THIS WIND SHIFT AS THE SURFACE LOW TRACKS INTO
THE DELMARVA. WINDS WILL GRADUALLY BECOME SLY LATER TONIGHT. BY
TOMORROW...THE DISSIPATING FRONT WILL ALLOW FOR S-SE WINDS 10-15 KT ALL
WATERS WITH A FEW GUSTS TO 20 KT POSSIBLE ACROSS THE SOUTHERN
COASTAL WATERS AND THE CURRITUCK SOUND. WAVES WILL REMAIN 1-2 FT
WITH SEAS 2-3 FT THROUGH SAT.
LATE SAT INTO THE MIDDLE OF NEXT WEEK...HIGH PRES WILL BUILD INTO
AND OVER THE MID-ATLANTIC REGION. THIS WILL RESULT IN GENERALLY S-SW
WINDS LESS THAN 15 KT. WAVES ON THE CHES BAY WILL CONTINUE TO
AVERAGE 1 TO 2 FT...WITH SEAS 2 TO 3 FT ON THE OCEAN.
&&
.HYDROLOGY...
SEVERAL ROUNDS OF HEAVY RAINFALL HAS RESULTED IN RAPID RISES IN
LOCAL RIVERS AND STREAMS. FLOOD WARNINGS ARE CURRENTLY IN EFFECT
FOR THE APPOMATTOX RIVER AT FARMVILLE AND MATTOAX WHERE MINOR
FLOODING IS FORECAST. THE LATEST FORECAST FOR RICHMOND WESTHAM
KEEPS THE HIGHEST STAGE BELOW MINOR FLOOD THRESHOLDS. THE MEHERRIN
RIVER NEAR LAWRENCEVILLE IS EXPECTED TO NEAR MINOR FLOOD STAGE
LATE TONIGHT INTO SATURDAY MORNING. ADDITIONALLY...THE NOTTOWAY
RIVER NEAR STONY CREEK WILL NEAR MINOR FLOOD STAGE OVERNIGHT.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SAM/AJZ
NEAR TERM...AJZ/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...JEF/JAO
MARINE...JDM/JAO
HYDROLOGY...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
915 PM EDT FRI JUL 12 2013
.SYNOPSIS...
COLD FRONT HAS STALLED ALONG THE COAST THIS AFTERNOON AND WILL
REMAIN OVER THE REGION THROUGH SATURDAY. HIGH PRESSURE WILL BUILD
INTO THE REGION FROM THE EAST THIS WEEKEND AS THE FRONT DISSIPATES
OVER THE AREA. HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
UPDATED TO REMOVE CENTRAL VA FROM THE FLASH FLOOD WATCH AS THE
THREAT FOR HEAVY RAINFALL HAS ENDED. FOR THE REMAINDER OF THE
WATCH AREA...A FEW ISOLATED AREAS OF HEAVY RAIN REMAIN POSSIBLE
THROUGH THE EVENING...BUT THE OVERALL THREAT IS QUICKLY
DIMINISHING.
PREVIOUS DISCUSSION...
PER LATEST MSAS ANALYSIS AND SFC OBSERVATIONS...COLD FRONT HAS
STALLED ACROSS SE VA THIS AFTERNOON. LATEST WATER VAPOR IMAGERY
CONTINUES TO SHOW PLUME OF MOISTURE LIFTING THROUGH THE REGION AS
LOW PRESSURE TO THE WEST SLOWLY DRIFTS SWD. LOW POSITION WILL
CONTINUE TO BE IN A FAVORABLE POSITION FOR STRONG UPPER LEVEL
FORCING (STRONG DIFFLUENCE ALOFT) OVER THE LOCAL AREA. SEEING
COOLING CLOUD TOPS OVER CNTRL/ERN NC ATTM AS A SHORT WAVE LIFTS
FROM THE SE. EXPECT ANOTHER WAVE OF SHOWERS AND EMBEDDED
THUNDERSTORMS TO LIFT NWD ALONG THE FRONT INTO NE NC/SE VA THROUGH
6 PM AND INTO ERN VA (MAINLY EAST OF INTERSTATE 95) THROUGH EARLY
TONIGHT. HAVE OPTED TO DROP HEADLINES OVER THE PIEDMONT AS DRY AIR
HAS WORKED IN ALOFT. LATEST RADAR TRENDS AND HRRR RUNS BACK THIS
UP WELL. HAVE ALSO EXTENDED FLASH FLOOD WATCH HEADLINES UNTIL
MIDNIGHT TONIGHT ALONG AND EAST OF INTERSTATE 95 TO ACCOUNT FOR
THE NEXT WAVE AND SATURATED SOILS. EXPECT THE WAVE TO LIFT
THROUGH THE LOCAL AREA BY MIDNIGHT...BUT SHOWERS EXPECTED TO
CONTINUE ALONG THE FRONT OVER SE VA/NE NC THROUGH LATE TONIGHT.
TEMPS EXPECTED TO FALL INTO THE UPPER 60S/LOW 70S TONIGHT UNDER
CLOUDY SKIES.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY NIGHT/...
MODELS CONTINUE TO HANDLE THE MID/UPPER LEVEL PATTERN WELL
THROUGH THE SHORT TERM. THE UPPER LOW WILL BECOME CUT OFF FROM THE
FLOW TONIGHT/SAT MORNING...AS HIGH PRESSURE STRENGTHENS OVER THE
CNTRL CONUS. THE LOW IS THEN PROGGED TO UNDERCUT THE
RIDGE...PROGRESSING SWWD THROUGH THE SHORT TERM TOWARD THE SRN
PLAINS. THIS WILL ALLOW UPPER/SFC HIGH PRESSURE TO BUILD INTO THE
REGION SAT...AND REMAINING CENTERED OVER THE OH VALLEY THROUGH THE
SHORT TERM. THE RESULT OVER THE LOCAL AREA WILL BE SUMMER LIKE
CONDITIONS WITH THE STORM TRACK REMAINING WELL TO THE NORTH OF THE
REGION. MOISTURE PLUME WILL MOVE INLAND AS UPPER LEVEL FLOW
BECOMES SELY SAT...WITH BEST POPS ACROSS THE PIEDMONT SAT
AFTERNOON. WHILE FORCING FOR ASCENT WILL BE SUBTLE...DIURNAL
FORCING AND ABUNDANT MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SAT AFTERNOON...WEST OF INTERSTATE 95. WILL KEEP
MENTION OF SLIGHT CHANCE POPS FOR THE PIEDMONT SUN AFTERNOON...BUT
BEST MOISTURE/DYNAMICS LOOKS TO BE WEST OF THE AREA. AREA WILL BE
UNDER THE INFLUENCE OF HIGH PRESSURE MON...BUT DO EXPECT MOISTURE
TO ADVECT FROM THE WRN ATLANTIC INTO THE REGION. PRESENCE OF A
WEAK LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES UNDER WEAK FLOW
ALOFT...MAY RESULT IN ISOLATED-WIDELY SCATTERED THUNDERSTORMS
ACROSS THE LOCAL AREA. WILL MAINTAIN SLIGHT CHANCE POPS DURING THE
AFTERNOON FOR DIURNAL FORCING.
NEAR SEASONABLE NORMAL TEMPS SAT UNDER CLEARING SKIES FROM E TO
W. WARMING TREND WILL COMMENCE SUN AS STRONG HEIGHT RISES AND
INCREASING LOW LEVEL THICKNESS VALUES PUSH TEMPS INTO THE LOW 90S.
HOWEVER...SE FLOW WILL PREVENT TEMPS FROM REACHING THEIR FULL
POTENTIAL (HIGHS GENERALLY IN THE LOW 90S). SLIGHTLY WARMER MONDAY
AS WINDS BECOME MORE SLY (HIGHS IN THE LOW 90S). TEMPS ALONG THE
COAST DURING THE SHORT TERM WILL BE SLIGHTLY COOLER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HOTTER AND DRIER WEATHER EXPECTED NEXT WEEK...
MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG H5 RIDGE (599DM)
RESIDING OVER THE OHIO VALLEY TUESDAY/WEDNESDAY OF NEXT WEEK. THE
RIDGE THEN SLOWLY SHIFTS EAST OVER THE MID-ATLANTIC REGION THURSDAY
BEFORE MOVING EAST TO OFF THE CAROLINA COAST BY NEXT FRIDAY. THE
POSITION AND STRENGTH OF THIS RIDGE POINTS TO A SPELL OF HOT WEATHER
ACROSS THE LOCAL AREA NEXT WEEK WITH MAX TEMPS RUNNING ABOUT 1
STANDARD DEVIATION ABOVE NORMAL (MID 90S). THIS STAGNANT AIRMASS
WILL ALSO RESULT IN WARM/MUGGY NIGHTS WITH LOWS IN THE MID/UPR 70S.
LITTLE OPPORTUNITY FOR PCPN WILL OCCUR IN THIS PATTERN AS WELL
OUTSIDE OF ISOLD CONVECTION OVER THE HIGHER TERRAIN TO OUR WEST OUR
ALONG THE AFTN SEA BREEZE. WILL GO NO HIGHER THAN SLIGHT CHC (20%)
POPS THROUGH THE PERIOD.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
A WEAK STNRY FRONT LINGERS OVER EASTERN VA AND NC WITH SHOWERS
CONTINUING TO DEVELOP OVER THE BAY AND RIVERS. SHOWERS SHOULD
AVOID THE TAF SITES THIS EVENING THOUGH REMAIN IN THE VCTY OF ORF
AND PHF THROUGH 03Z. THE FRONT HAS MADE SFC WINDS SOMEWHAT
VARIABLE THIS EVENING WITH WEAK NLY WINDS AT RIC AND SBY WHILE
STATION OVER SE VA AND NE NC REMAIN SLY. WIND WILL RETURN A SLY
DIRECTION AT RIC AND SBY OVERNIGHT. GIVEN THE AMOUNT OF LOW LEVEL
MOISTURE FROM RECENT RAINS...LIGHT WINDS AND PROXIMITY OF THE
FRONT SOME GUIDANCE SUGGEST A PERIOD OF IFR CEILINGS AT MOST TAF
SITES ANYWHERE FROM 03Z-15Z. FOR THE MOST PART HAVE LIMITED IFR
CEILING TO A PERIOD AFTER 06Z TO JUST AFTER 12Z. HEATING AND
MIXING WILL GRADUALLY ERODE IFR CEILINGS THROUGH MID MORNING WITH
A CONTINUOUS BKN030-040 THROUGH THE AFTERNOON. SCATTERED SHOWERS
AND ISOLATED TSTMS SAT AFTERNOON WILL DEPEND ON FRONT AS IT WASHES
OUT AND MOVES WEST. SCATTERED SHOWERS SATURDAY WILL END FROM EAST
TO WEST AS THE BERMUDA HIGH BEGINS TO BUILD BACK IN FROM OFFSHORE
LATER IN THE DAY.
&&
.MARINE...
NO HEADLINES EXPECTED THRU AT LEAST THIS WEEKEND. A FRONTAL BOUNDARY
WILL REMAIN STALLED OVER THE DELMARVA INTO SE VA THROUGH SAT BEFORE
DISSIPATING LATE IN THE DAY. WINDS HAVE BEEN SOMEWHAT VARIABLE
THIS EVENING BECOMING NLY OVER THE MIDDLE AND UPPER BAY. FORECAST
UPDATE REFLECTED THIS WIND SHIFT AS THE SURFACE LOW TRACKS INTO
THE DELMARVA. WINDS WILL GRADUALLY BECOME SLY LATER TONIGHT. BY
TOMORROW...THE DISSIPATING FRONT WILL ALLOW FOR S-SE WINDS 10-15 KT ALL
WATERS WITH A FEW GUSTS TO 20 KT POSSIBLE ACROSS THE SOUTHERN
COASTAL WATERS AND THE CURRITUCK SOUND. WAVES WILL REMAIN 1-2 FT
WITH SEAS 2-3 FT THROUGH SAT.
LATE SAT INTO THE MIDDLE OF NEXT WEEK...HIGH PRES WILL BUILD INTO
AND OVER THE MID-ATLANTIC REGION. THIS WILL RESULT IN GENERALLY S-SW
WINDS LESS THAN 15 KT. WAVES ON THE CHES BAY WILL CONTINUE TO
AVERAGE 1 TO 2 FT...WITH SEAS 2 TO 3 FT ON THE OCEAN.
&&
.HYDROLOGY...
SEVERAL ROUNDS OF HEAVY RAINFALL HAS RESULTED IN RAPID RISES IN
LOCAL RIVERS AND STREAMS. FLOOD WARNINGS ARE CURRENTLY IN EFFECT
FOR THE APPOMATTOX RIVER AT FARMVILLE AND MATTOAX WHERE MINOR
FLOODING IS FORECAST. HEAVY RAINFALL OVER THE UPPER JAMES BASIN
COULD PRODUCE MINOR FLOODING ALONG THE JAMES RIVER AT RICHMOND
WESTHAM DURING THE DAY SATURDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR MDZ021>025.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR NCZ012>017-
030>032-102.
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EDT TONIGHT FOR VAZ077-078-
084>100.
MARINE...NONE.
&&
$$
SYNOPSIS...ESS/SAM
NEAR TERM...AJZ/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...JEF/JAO
MARINE...JDM/JAO
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS GLASGOW MT
209 PM MDT THU JUL 11 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SATURDAY...
MAIN CONCERN WILL BE CONVECTION INITIATION HEADING INTO THIS
AFTERNOON AND EVENING. CURRENT VISIBLE SATELLITE IMAGERY IS
INDICATING A HUGE MASS OF CLOUDINESS OVERSPREADING THE CWA FROM
SOUTHWEST TO NORTHEAST...WITH MORE IN THE WAY OF SUNSHINE ACROSS
THE SOUTHEAST. THE SOUTHEASTERN PORTIONS OF THE CWA THEREFORE WILL
BE MUCH MORE UNSTABLE THIS AFTERNOON AND EVENING AND THIS IS WHERE
HIGHER CAPE AND MORE FAVORABLE LIFTED INDEX VALUES ARE PRESENT.
STORM SCALE ENSEMBLE OF OPPORTUNITY...HRRR...AND NAM SOLUTIONS DO
CAPTURE THIS WELL AND THUS THERE IS HIGHER CONFIDENCE IN ISOLATED
TO SCATTERED THUNDERSTORMS IN THIS AREA. PRAIRIE...DAWSON...WIBAUX...AND
POSSIBLY AS FAR NORTH AS RICHLAND COUNTIES APPEAR TO HAVE THE BEST
POTENTIAL FOR A FEW STORMS TO BECOME SEVERE AS THEY TRAVERSE
THROUGH. LATEST NAM BUFKIT SOUNDINGS CONTINUE TO NICELY DEPICT
INVERTED-V SIGNATURE AND SO STRONG WINDS WILL BE THE PRIMARY
CONCERNS WITH ANY STORMS. AS UPPER LEVEL WAVE AND FRONT PUSHES
FURTHER EAST AND MEETS UP WITH THIS UNSTABLE ENVIRONMENT...STORMS
SHOULD INITIATE. IN FACT...ALREADY SEEING THE FIRST SIGNS OF
CONVECTION JUST SOUTH OF THE CWA IN VISIBLE SATELLITE IMAGERY.
THE 11/12Z MODEL GUIDANCE SHOWS A BIT OF DISCREPANCY IN TERMS OF
THIS EVENING INTO TONIGHT. WHILE ANY CONVECTION THAT PUSHES
THROUGH THE SOUTHEAST SHOULD BE DONE WITH BY EVENING...THE LATEST
HRRR IS SHOWING SOME SHOWER ACTIVITY OVERSPREADING THE ENTIRE CWA
OVERNIGHT FROM SOUTHWEST TO NORTHEAST. THE NAM/GFS/ECMWF ARE NOT
AS BULLISH ON THIS...BUT GIVEN THE AREAL EXTENT OF CLOUDINESS
MOVING INTO THE FORECAST REGION AND SHOWERS SHOWING UP ON RADAR
THAT ARE MOVING IN...DID LEAN ON THE HRRR FOR NOW...BUT POPS STILL
MAY PROVE TO BE SOMEWHAT CONSERVATIVE. AT ANY RATE...ANOTHER
SHORTWAVE WILL MOVE ACROSS THE INTERNATIONAL BORDER FRIDAY INTO
SATURDAY WHICH SHOULD MAINTAIN CHANCES FOR SHOWERS AND
THUNDERSTORMS. BEHIND THIS EVENING/S FRONTAL PASSAGE THOUGH
TEMPERATURES SHOULD BE MORE SEASONABLE. WILL NEED TO MONITOR FOR
POSSIBLE SEVERE AGAIN ON SATURDAY...DOES LOOK LIKE THE BEST
FORCING WILL BE ACROSS SASKATCHEWAN CLOSER TO THE TRACK OF THE
WAVE. MALIAWCO
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
MOST OF THE LONG TERM FORECAST PERIOD IS CHARACTERIZED BY A
PERSISTENT SOUTHWESTERLY FLOW ALOFT WITH MULTIPLE EMBEDDED SHORT
WAVE DISTURBANCES THROUGHOUT.
MODES ARE HINTING THAT A SLIGHT RIDGING INFLUENCE MAY PUSH INTO
THE NORTHERN HIGH PLAINS TUESDAY AND BEYOND.
THERE ARE ENOUGH MODEL DISCREPANCIES TO RATE THE FORECAST
CONFIDENCE ABOUT AVERAGE OR SLIGHTLY BELOW AVERAGE. HAVE THEREFORE
CHOSEN A BLEND AND BROAD-BRUSH APPROACH FOR NOW. MADE ONLY SLIGHT
ADJUSTMENTS TO THE GOING FORECAST. EXPECT THE COOLEST DAY TO BE
TUESDAY AND THE WARMEST DAY TO BE THURSDAY WITH OFF AND ON
CHANCES FOR SHOWERS AND THUNDERSTORMS. BMICKELSON
PREVIOUS LONG TERM DISCUSSION...SYNOPTIC SET UP... LONG TERM
BEGINS WITH A LARGE HEAT DOME STRETCHED OVER THE CENTRAL AND
SOUTHERN US PLAINS AND FOUR CORNERS REGION. A CLOSED LOW EXISTS
OVER THE NORTHWEST TERRITORIES WITH A TROUGH JUTTING OFF OVER
NORTHERN ALBERTA AND BRITISH COLUMBIA. NORTHEAST MONTANA LIES IN
BETWEEN THESE TWO FEATURES OF FLUCTUATING ZONAL ALOFT ALL THE WAY
BACK TO OFF THE COAST OF THE PACIFIC NORTHWEST.
SATURDAY NIGHT THROUGH MONDAY... FLOW WILL TILT SLIGHTLY SOUTHWEST
AND ALLOW A FEW SHORTWAVES TO PASS THROUGH NORTHEAST MONTANA ALONG
WITH PACIFIC MOISTURE. TIMING OF ANY PARTICULAR WAVE IS DIFFICULT
AND WASHED OUT. HOWEVER... THE EASTERN HALF OF THE CWA APPEARS TO
HAVE HIGHER CHANCES FOR POPS AS MOISTURE IS EXPECTED TO INCREASE
TO THE EAST NEAR THE SURFACE.
MONDAY NIGHT THROUGH WEDNESDAY... THE HEAT DOME OVER THE WESTERN
HALF OF THE US WILL EXTEND A RIDGE UP THROUGH THE THE PACIFIC
NORTHWEST AND BRITISH COLUMBIA. THE RIDGE IS WEAK... SO SHORTWAVES
COULD STILL BREAK THROUGH... BUT IT IS ANTICIPATED TO SUBTLY TILT
FLOW TO THE NORTHWEST WITH DRIER MID LEVELS. A SEMI-PERMANENT LEE
SURFACE TROUGH WILL SET UP DURING THESE PERIODS AND BE A FOCAL
POINT FOR ANY AFTERNOON STORM DEVELOPMENT. TIMING OF WAVES DURING
THIS PERIOD IS RATHER DIFFICULT HOWEVER. EXPECT A WARMING TREND AS
THE RIDGE BUILDS TO THE WEST AND INCREASES INFLUENCE.
WEDNESDAY NIGHT ONWARD... MODELS ARE HINTING AT A TROUGH DROPPING
SOUTH OF THE GULF OF ALASKA TO OFF THE COAST OF THE PACIFIC
NORTHWEST. THIS WILL NUDGE THE BUILDING HEAT DOME OVER THE
INTER-MOUNTAIN WEST EAST... INCREASING THE INFLUENCE OVER NORTHEAST
MONTANA AND TRENDING WARMER AND DRIER WEATHER OVERALL. GAH
&&
.AVIATION...
FLIGHT CATEGORY:
MOSTLY VFR WITH LOWER CONDITIONS POSSIBLE FOR KSDY AND KGDV.
AMENDMENTS MAY BE NEEDED THERE FOR THUNDERSTORMS LATER TODAY.
IMPACTS:
SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
EVENING...ESPECIALLY AT KSDY AND KGDV. TEMPORARY REDUCTIONS IN
FLIGHT CONDITIONS CAN BE EXPECTED. THESE TERMINALS SHOULD BE
AWARE OF STRONG VERTICAL WIND SHEAR DURING THE AFTERNOON AND
EVENING HOURS WHICH COULD COMPLICATE GROUND OPERATIONS. THIS MAY
RESULT IN STRONG OR GUSTY WINDS...ESPECIALLY IN OR NEAR
THUNDERSTORMS. BRIEF FUEL LOADING CONDITIONS ARE POSSIBLE WITH
STORMS.
AREA WINDS:
SOUTHWEST WINDS 10 TO 20 KTS SUSTAINED WITH POSSIBLE GUSTS NEAR
30KTS FOR KSDY AND KGDV CONTINUING THROUGH THIS AFTERNOON. WINDS
WILL VEER TO THE WEST AND NORTHWEST BEHIND A COLD FRONT LATER THIS
AFTERNOON AND EVENING.
MICKELSON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
938 AM MDT THU JUL 11 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH SATURDAY...
UPDATE...
SHORT TERM FORECAST LOOKS TO BE ON TRACK. STILL EXPECTING A RATHER
HOT DAY ACROSS THE CWA WITH TEMPERATURES SOARING WELL INTO THE
90S. POTENTIAL EXISTS FOR A FEW LOCATIONS TO EXCEED 100 DEGREES IN
THE YELLOWSTONE VALLEY AND IN SOUTHEASTERN PORTIONS OF THE
FORECAST AREA WHERE 850MB TEMPERATURES ARE EXPECTED TO BE A COUPLE
OF DEGREES WARMER THIS AFTERNOON. GIVEN INCREASED CLOUD COVER INTO
THE WESTERN ZONES THIS AFTERNOON AND EARLIER PASSAGE OF THE
FRONT...WENT AHEAD AND NUDGED HIGHS DOWN JUST A BIT IN THOSE LOCATIONS.
OTHERWISE THE MAIN FOCUS WAS ON THE SEVERE WEATHER POTENTIAL IN
THE EASTERN ZONES. AS THE RIDGE AXIS PASSES EAST...NORTHEAST
MONTANA WILL ENTER INTO A REGIME OF SOUTHWEST FLOW ALOFT AND AN
ENHANCED REGION OF FAVORED VERTICAL ASCENT OUT AHEAD OF AN
APPROACHING UPPER LEVEL SHORTWAVE. WITH FRONTAL PASSAGE FURTHER
FORCING LIFT...AND INVERTED-V SOUNDINGS PRESENT...EXPECT ANY
STORMS THAT DEVELOP TO BE CAPABLE OF STRONG WIND GUSTS. CANNOT
RULE OUT POTENTIAL FOR HAIL. HEAVY RAIN MAY BE KEPT AT A MINIMUM
GIVEN SUCH DRY LOW LEVELS. ANY DOWNDRAFTS THOUGH MAY BE
ACCELERATED THROUGH EVAPORATIVE COOLING IN THE DRIER LOW LEVELS.
WILL NEED TO WATCH THE SIDNEY TO GLENDIVE AREA IN PARTICULAR THIS
AFTERNOON GIVEN AGREEMENT WITH THE SPC STORM SCALE ENSEMBLE OF
OPPORTUNITY PRODUCT ALONG WITH RECENT HRRR AND NAM SOLUTIONS. THIS
IS ALSO WHERE THE HIGHEST CAPE AND MORE FAVORABLE LIFTED INDEX
VALUES LOOK TO BE FOR THIS AFTERNOON AND EVENING. MALIAWCO
PREVIOUS SHORT TERM DISCUSSION...
UPPER RIDGE AXIS EXPECTED TO MOVE INTO THE DAKOTAS TODAY WITH
SHORTWAVE LIFTING OUT OF THE GREAT BASIN. STRONG THERMAL RIDGE
WILL PUSH TEMPERATURES CLOSE TO 100 THIS AFTERNOON...PARTICULARLY
OVER THE SOUTHEAST ZONES IN ADVANCE OF THE SHORTWAVE.
SOUTHEAST LOW LEVEL FLOW WILL BE STRENGTHENING INTO THE NORTHERN PLAINS
BRINGING GULF MOISTURE INTO THE REGION AND INTENSIFYING THE LEE TROF
OVER CENTRAL MONTANA. AS THE SHORTWAVE PUSHES THIS TROF/FRONT EASTWARD
THIS AFTERNOON COULD SEE CONVECTIVE DEVELOPMENT AS THE FRONT
ENCOUNTERS GREATER INSTABILITY OVER THE EASTERN ZONES. ALTHOUGH
BOUNDARY LAYER DEW POINTS INTO THE 60S ARE ANTICIPATED...VERY HOT
SURFACE TEMPERATURES AND DRY MID LEVELS WILL RESULT IN INVERTED V
SOUNDINGS WITH A HIGH LCL. HIGH BASED STORMS WILL LITTLE
PRECIPITATION AND STRONG WIND GUSTS ARE EXPECTED AND SOME COULD BE
SEVERE NEAR THE NORTH DAKOTA BORDER LATE THIS AFTERNOON AND INTO
THE EVENING.
TEMPERATURES CLOSER TO NORMAL EXPECTED ON FRIDAY AND SATURDAY.
TROF ALONG THE WESTERN CANADIAN COAST WILL SWING A SHORTWAVE EAST
ALONG THE INTERNATIONAL BORDER FRIDAY NIGHT INTO SATURDAY...ALONG
WITH ANOTHER FRONTAL SYSTEM. THUNDERSTORMS ARE AGAIN EXPECTED
WITH THIS SYSTEM. EBERT
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
SYNOPTIC SET UP... LONG TERM BEGINS WITH A LARGE HEAT DOME
STRETCHED OVER THE CENTRAL AND SOUTHERN US PLAINS AND FOUR CORNERS
REGION. A CLOSED LOW EXISTS OVER THE NORTHWEST TERRITORIES WITH A
TROUGH JUTTING OFF OVER NORTHERN ALBERTA AND BRITISH COLUMBIA.
NORTHEAST MONTANA LIES IN BETWEEN THESE TWO FEATURES OF FLUCTUATING
ZONAL ALOFT ALL THE WAY BACK TO OFF THE COAST OF THE PACIFIC
NORTHWEST.
SATURDAY NIGHT THROUGH MONDAY... FLOW WILL TILT SLIGHTLY SOUTHWEST
AND ALLOW A FEW SHORTWAVES TO PASS THROUGH NORTHEAST MONTANA ALONG
WITH PACIFIC MOISTURE. TIMING OF ANY PARTICULAR WAVE IS DIFFICULT
AND WASHED OUT. HOWEVER... THE EASTERN HALF OF THE CWA APPEARS TO
HAVE HIGHER CHANCES FOR POPS AS MOISTURE IS EXPECTED TO INCREASE
TO THE EAST NEAR THE SURFACE.
MONDAY NIGHT THROUGH WEDNESDAY... THE HEAT DOME OVER THE WESTERN
HALF OF THE US WILL EXTEND A RIDGE UP THROUGH THE THE PACIFIC
NORTHWEST AND BRITISH COLUMBIA. THE RIDGE IS WEAK... SO SHORTWAVES
COULD STILL BREAK THROUGH... BUT IT IS ANTICIPATED TO SUBTLY TILT
FLOW TO THE NORTHWEST WITH DRIER MID LEVELS. A SEMI-PERMANENT LEE
SURFACE TROUGH WILL SET UP DURING THESE PERIODS AND BE A FOCAL
POINT FOR ANY AFTERNOON STORM DEVELOPMENT. TIMING OF WAVES DURING
THIS PERIOD IS RATHER DIFFICULT HOWEVER. EXPECT A WARMING TREND AS
THE RIDGE BUILDS TO THE WEST AND INCREASES INFLUENCE.
WEDNESDAY NIGHT ONWARD... MODELS ARE HINTING AT A TROUGH DROPPING
SOUTH OF THE GULF OF ALASKA TO OFF THE COAST OF THE PACIFIC
NORTHWEST. THIS WILL NUDGE THE BUILDING HEAT DOME OVER THE
INTERMOUNTAIN WEST EAST... INCREASING THE INFLUENCE OVER NORTHEAST
MONTANA AND TRENDING WARMER AND DRIER WEATHER OVERALL. GAH
&&
.AVIATION...
FLIGHT CATEGORY:
MOSTLY VFR WITH LOWER CONDITIONS POSSIBLE. AMENDMENTS MAY BE
NEEDED FOR THUNDER LATER TODAY.
IMPACTS:
SHOWERS AND THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND
EVENING...ESPECIALLY AT KSDY AND KGDV. TEMPORARY REDUCTIONS IN
FLIGHT CONDITIONS CAN BE EXPECTED. THESE TERMINALS WILL ALSO WANT
TO BE AWARE OF STRONG VERTICAL WIND SHEAR DURING THE AFTERNOON AND
EVENING HOURS WHICH COULD COMPLICATE GROUND OPERATIONS. THIS MAY
RESULT IN STRONG GUSTY WINDS...ESPECIALLY IN OR NEAR
THUNDERSTORMS. BRIEF FUEL LOADING CONDITIONS ARE POSSIBLE WITH
STORMS.
AREA WINDS:
SOUTHWEST 5 TO 10 KTS EARLY THIS MORNING INCREASING TO 10 TO 20
KTS SUSTAINED WITH POSSIBLE GUSTS NEAR 30KTS FOR KSDY AND KGDV
BEGINNING EARLY THIS AFTERNOON. WINDS WILL VEER TO THE WEST AND
NORTHWEST BEHIND A COLD FRONT LATER THIS AFTERNOON.
GAH/BLM
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
902 AM MDT THU JUL 11 2013
.UPDATE...
MADE A FEW ADJUSTMENTS TO POPS TODAY THROUGH THIS EVENING. STREAM
OF VORTICITY WILL MOVE NE INTO THE WESTERN ZONES TODAY THROUGH
THIS EVENING BRINGING A SLIGHT CHANCE OF THUNDERSTORMS. SOUNDINGS
WERE DRY IN THE LOW-LEVELS BUT HAD A WET MICROBURST APPEARANCE
OVERALL. SPREAD THE SLIGHT CHANCE INTO KBIL THIS AFTERNOON AND
EVENING. DESPITE WARM 700 MB AIRMASS...SOUNDINGS HAD LITTLE IF ANY
CAP OVER KBIL. FURTHER E...CAP LOOKED MUCH STRONGER UNTIL THE FAR
SE ZONES WHERE BUFKIT FORECASTS OF CAPES OF 500-1000 J/KG...AND
AROUND 40 KT BULK SHEAR WILL BE REALIZED IF LIFT IS STRONG ENOUGH.
BUFKIT HAD NO CIN OVER KBHK LATE IN THE DAY. SURFACE TROUGH WAS
OVER CENTRAL ZONES THIS MORNING PER SURFACE OBSERVATIONS. RAP AND
WRF MOVED TROUGH E WITH TIME WITH A SURFACE LOW OVER WY. WEAK COLD
FRONT WILL CATCH UP TO THE TROUGH THIS AFTERNOON. THESE FACTORS
WILL COMBINE WITH INCREASING VORTICITY TO BRING A SLIGHT CHANCE OF
THUNDERSTORMS TO MAINLY CARTER AND FALLON COUNTIES. STORMS WILL BE
FAIRLY FAST-MOVING DUE MODERATELY FAST FLOW ALOFT. CAPES AND BULK
SHEAR SUPPORTED POSSIBLE SEVERE STORMS OVER THE SE ZONES. MIXING
TO ABOVE 700 MB SUPPORTED TEMPERATURES NEAR RECORD VALUES IN SOME
LOCATIONS. ONLY COMPLICATING FACTOR FOR THE TEMPERATURES REACHING
THESE VALUES WILL BE HIGH CLOUD COVER COMING IN FROM THE SW.
ARTHUR
&&
.SHORT TERM...VALID FOR TDY AND FRI...
TODAY WE ARE EXPECTING SOME OF THE HOTTEST TEMPERATURES OF THE
SEASON SO FAR. AS AN UPPER LEVEL RIDGE AXIS SHIFTS EAST OF US THE
MID LEVEL THERMAL AXIS WILL INCREASE OVER OUR REGION IN AN
INCREASING SW FLOW. BUFKIT OVERVIEWS SUGGEST MIXING WELL ABOVE
700MB WILL TAKE PLACE AND BRING SOME VERY WARM AIR DOWN INTO THE
BOUNDARY LAYER. NUMERICAL GUIDANCE TRENDS CONFIRM THIS AND I HAVE
THEREFORE BOOSTED TEMPERATURES FROM A FEW TO SEVERAL DEGREES IN
MANY AREAS...ESPECIALLY THE AREAS BETWEEN BILLINGS AND MILES CITY
WHERE THE MERCURY WILL BENEFIT MOST FROM THE TIMING OF A WEAK
FRONT MOVING THROUGH THE AREA THIS AFTERNOON. A FEW LOCATIONS SUCH
AS MILES CITY MAY THREATEN THEIR RECORD HIGHS.
AS FOR PRECIPITATION TODAY...THE AFOREMENTIONED FRONT WILL RUN
INTO SOME HIGH CAPE ALONG THE EASTERN BORDER COUNTIES WHERE THE
VERTICAL WIND PROFILES SUGGEST SOME DEEP LAYERED SHEAR. I SUSPECT
WE COULD SEE AN ISOLATED SEVERE STORM DEVELOP HERE IN THE MID TO
LATE AFTERNOON HOURS...SO WILL ADD SEVERE WORDING IN THE FAR
EASTERN ZONES. MUCH OF THIS ACTIVITY WILL PROBABLY BE IN THE
DAKOTAS BY EVENING. ALSO...OUT WEST THERE IS AN OBVIOUS INFLUX OF
MOISTURE FROM THE SW EVIDENT ON WATER VAPOR LOOPS. PROGGS ALSO
INDICATE A DECENT SHORT WAVE COMING OUT OF THE MOUNTAINS. SO
ISOLATED STORMS IN OUR WEST TO NORTHWEST ZONES LOOK GOOD FOR
LATER TODAY...THOUGH THE ENVIRONMENT THERE IS DRIER IN THE LOW
LEVELS AND WILL NOT SUPPORT MUCH CHANCE OF SEVERE STORMS.
LOOK FOR COOLER TEMPERATURES ON FRIDAY WITH A SLIGHT CHANCE OF
THUNDERSTORMS. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
EXTENDED FORECAST COULD BE CONSIDERED TYPICAL FOR MID JULY...
GENERALLY HOT WITH AT LEAST A SLIGHT CHANCE OF TSTMS EACH DAY.
PATTERN OVER THE NORTHERN ROCKIES WILL BE INFLUENCED BY STRONG
RIDGING OVER THE INTERMOUNTAIN WEST...WITHIN WHICH THERE WILL BE
MONSOONAL SURGES...AND PIECES OF SHORTWAVE ENERGY FROM PAC COAST
TROF AND WESTERN CANADA. HIGHER THETA-E AIR SUPPORTIVE OF
STRONGER TSTM ACTIVITY WILL GENERALLY RESIDE IN OUR EAST NEAR THE
DAKOTAS BORDER...AND HAVE KEPT HIGHEST POPS IN THIS AREA...BUT
COULD SEE AN OCCASIONAL WESTWARD PUSH OF THIS MOISTURE ESPECIALLY
MON-WED OF NEXT WEEK WITH EAST WIND REGIME IN PLACE. EXPECT
TEMPERATURES TO BE NEAR OR SLIGHTLY ABOVE NORMAL EACH DAY...WITH
THE EXPECTATION THAT PACIFIC ENERGY WILL KEEP THE RIDGE SUPPRESSED
ENOUGH TO NOT ALLOW FOR ANY SIGNIFICANT SURGES OF HEAT...WHICH WE
ARE CERTAINLY PRONE TO DO AS WE ENTER OUR HOTTEST TIME OF YEAR.
JKL
&&
.AVIATION...
ISOLATED THUNDERSTORMS WILL DEVELOP OVER THE AREA FROM KBIL W
THIS AFTERNOON AND EVENING. THUNDERSTORMS SHOULD BE MAINLY HIGH-
BASED WITH GUSTY WINDS TO 40 KT. FURTHER E...FROM KMLS E AND
SE...ISOLATED THUNDERSTORMS WILL ALSO DEVELOP THIS AFTERNOON AND
MOVE E THROUGH THIS EVENING. MVFR CONDITIONS...LARGE HAIL AND
WIND GUSTS TO 60 KT WILL ACCOMPANY THESE STORMS. VFR CONDITIONS
WILL PREVAIL LATE TONIGHT AND FRI MORNING. LOCALIZED MOUNTAIN
OBSCURATION WILL OCCUR THROUGH THE PERIOD DUE TO ISOLATED
MOUNTAIN SHOWERS AND THUNDERSTORMS. ARTHUR
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 098 064/090 062/090 061/087 062/093 063/093 065/096
2/T 21/B 12/T 22/T 22/T 22/T 22/T
LVM 093 057/087 053/090 051/088 051/090 052/092 057/095
2/T 22/T 22/T 22/T 22/T 22/T 22/T
HDN 101 064/090 062/092 059/089 061/094 063/095 065/097
0/G 11/B 12/T 22/T 22/T 22/T 22/T
MLS 103 067/091 064/091 063/088 064/094 064/094 067/096
2/T 11/B 22/T 22/T 23/T 32/T 22/T
4BQ 101 063/090 060/091 061/087 061/092 061/093 062/095
2/T 11/B 22/T 22/T 23/T 32/T 22/T
BHK 096 063/087 061/088 062/084 061/088 062/091 065/092
2/T 21/B 23/T 33/T 33/T 33/T 22/T
SHR 099 060/088 057/091 056/087 056/091 056/092 060/093
0/B 11/B 22/T 22/T 23/T 32/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
911 PM MDT FRI JUL 12 2013
.UPDATE...
QUICK UPDATE TO TWEAK POPS FOR THE EVENING PERIOD. BOUNDARY
INTERACTIONS WILL BE THE MAIN DRIVING FORCE FOR THIS EVENINGS
CONVECTION. HRRR SHOWS MOST OF TONIGHTS PRECIPITATION ACROSS
CENTRAL AND WEST CENTRAL NM...AND BASED ON CURRENT TRENDS AND
OUTFLOW BOUNDARIES...THINK THE HRRR HAS A GOOD HANDLE ON IT.
HOWEVER...ADDITIONAL THUNDERSTORMS MOVING UP FROM OLD MEXICO MAY
MOVE INTO THE SW ZONES LATE. OTHERWISE...SOME MINOR TWEAKS TO QPF
AND SKY COVER WERE MADE. UPDATES ALREADY OUT.
34
&&
.PREV DISCUSSION...521 PM MDT FRI JUL 12 2013...
.AVIATION...
00Z TAF CYCLE
UPPER HIGH CENTER VCNTY SW KS AT 00Z WILL SHIFT BACK WWD AND
OVER NEW MEXICO NEXT 24 HRS. EARLIER STORMS WHICH IGNITED OVER
THE HIGHER TERRAIN HAVE...ALONG WITH OUTFLOW BOUNDARIES...TRIGGERED
SHOWERS AND STORMS OVER PORTIONS OF THE LOWER ELEVATIONS. CELL
MOVEMENT GENLY TO THE NORTH. ISOLD HEAVY RAIN MAY RESULT IN MVFR
TO BRIEFLY IFR CIGS/VSBYS AND MT OBSCURATIONS THROUGH 03Z BEFORE
CONVECTION SLOWLY DIMINISHES. MODERATE SWLY WINDS EXPECTED OVER
NORTHEAST AND EAST CENTRAL PLAINS AS LEE TROF OVER ERN CO STRENGTHENS.
300 PM MDT FRI JUL 12 2013...
EXPECT SOUTH TO SOUTH SOUTHWEST LOW LEVEL FLOW FROM THE CENTRAL
MOUNTAINS THROUGH THE EASTERN PLAINS THIS AFTERNOON AND EVENING AS
A LEE SIDE TROUGH/LOW PRESSURE DEEPENS ACROSS SE CO AND NE NM.
ACROSS THE NORTHERN MOUNTAINS AND THE WEST EXPECT VARIABLE LOW
LEVEL FLOW FROM THE AZ STATE LINE THROUGH THE RIO GRANDE VALLEY.
VARIABLE TO GENERALLY SOUTH TO NORTH STORM MOTIONS IN THE WEST AND
NORTHERN MOUNTAINS...AROUND 10 MPH OR LESS...ALLOWING FOR GREATER
PRECIPITATION ACCUMULATION AND FLASH FLOODING POTENTIAL. ACROSS
THE EAST STORM MOTIONS WILL BE GENERALLY FROM THE SOUTH TO NORTH
AROUND 15 MPH OR GREATER. THE 12Z KABQ SOUNDING RECORDED 1.07
INCHES OF PWAT...STILL PLENTIFUL BUT NOT AS COPIOUS AS YESTERDAY.
HOWEVER...TODAY WE HAVE GREATER INSTABILITY WITH CAPE OF 1792 J/KG
COMPARED TO 760 J/KG YESTERDAY MORNING. THUS...OVERALL MORE STORMS
EXPECTED THROUGH THIS EVENING AS COMPARED TO YESTERDAY. CURRENT
GOES WATER VAPOR IMAGERY CLEARLY DEPICTS A MONSOONAL MOISTURE
PLUME CIRCULATING NORTH...AROUND THE UPPER HIGH CENTERED OVER THE
SOUTHERN PLAINS...FROM NW MEXICO ACROSS AZ/NM AND NORTH ACROSS THE
ROCKIES INTO THE NORTHERN PLAINS. THROUGH THE WEEKEND THE
MONSOONAL MOISTURE PLUME AND ATTENDANT CONVECTIVE ACTIVITY WILL BE
FOCUSED ACROSS THE SOUTHWESTERN AND WESTERN PORTIONS OF NEW
MEXICO. CONVECTION WILL BE LEAST LIKELY ACROSS THE EASTERN PLAINS
THROUGH THE WEEKEND.
EARLY NEXT WEEK... A HIGHLY UNUSUAL PATTERN DEVELOPS...WITH AN UPPER
LOW RETROGRADING ACROSS OKLAHOMA AND NORTHERN TEXAS INTO EASTERN NEW
MEXICO BY MONDAY EVENING. THIS UPPER LOW MORPHS INTO A HYBRID LOW
WITH SUBTROPICAL CHARACTERISTICS AS IT NEARS NEW MEXICO. MODELS NOW
INDICATE THAT ON MONDAY THERE IS THE POTENTIAL FOR A NORTH TO SOUTH
BAND OF RAIN TO MOVE GENERALLY FROM EAST TO WEST OR SOUTHWEST ACROSS
THE FORECAST AREA. THIS RAIN BAND IS PUSHED WEST BY A PERSISTENT EAST
OR NORTHEAST WIND DRIVEN BY A SUBSTANTIAL 14 MB EAST TO WEST SURFACE
PRESSURE GRADIENT BETWEEN THE SURFACE HEAT LOW OVER ARIZONA AND A
SURFACE HIGH PRESSURE OVER THE OK-TX PANHANDLES. SHOULD THIS OCCUR...
THERE IS A FLASH FLOOD THREAT POTENTIAL FOR PERIODS OF HEAVY
RAINFALL ACROSS THE EAST SLOPES OF THE CENTRAL MOUNTAINS...FROM
THE SACRAMENTOS TO THE SANGRE DE CRISTOS. WE WILL MONITOR THIS
THREAT POTENTIAL AS THE WEATHER PATTERN EVOLVES AND DEVELOPS.
ON TUESDAY AND WEDNESDAY THE HYBRID UPPER LOW MOVES ACROSS NEW MEXICO
THEN TRACKS SOUTH INTO CHIHUAHUA. AS IT DOES SO...THE DOOR IS OPENED
TO VERY MOIST SOUTHEASTERLY FLOW...INCREASING THE CHANCE FOR HEAVY
RAIN ACROSS THE EASTERN PLAINS AND ESPECIALLY SOUTHEASTERN PORTIONS
OF THE FORECAST AREA.
ON THURSDAY AND FRIDAY THE HYBRID UPPER LOW MIGRATES A BIT FURTHER
SOUTH INTO EAST CENTRAL CHIHUAHUA. THE UPPER HIGH IS DISPLACED NW
ACROSS WY/UT/NV...ALLOWING FOR A WEAK FLOW ALOFT OVER NM...AND AMPLE
LOW LEVEL MOISTURE. THIS PATTERN WILL SETUP A CONVECTIVE RECYCLING
MODE WITH AFTERNOON STORMS INITIATING OVER THE HIGHER TERRAIN AND A
RETURN TO SEASONAL TEMPERATURES AND PRECIPITATION CHANCES.
BENNETT
.FIRE WEATHER...
ACTIVE WEATHER CONTINUING TONIGHT WITH POSSIBLY A SLIGHT DOWNTICK ON
SATURDAY AS THE UPPER HIGH SHIFTS WWD AGAIN AND OVER NEW MEXICO. FOR
SUNDAY AND INTO NEXT WEEK...MODELS STILL AGREEING ON A POTENTIALLY
ACTIVE AND WET PATTERN. AT LEAST A PORTION OF THE UPPER HIGH WILL BE
SHUNTED TO OUR WEST THANKS TO AN UPPER LOW CIRCULATION...WHICH
MODELS INDICATE WILL SLOWLY MIGRATE OVER NEW MEXICO AND THEN WEAKEN
DURING THE WORK WEEK.
THE INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH THE LOW AND
RESULTING PRECIPITATION SHOULD RESULT IN HIGH TEMPERATURES ACROSS
NORTHERN AND CENTRAL NEW MEXICO THAT RANGE FROM NEAR 5 TO 15 DEGREES
BELOW AVERAGE FOR MID JULY FOR NEXT MONDAY THROUGH WEDNESDAY. HIGHS
WILL REMAIN BELOW AVERAGE FOR THE REMAINDER OF NEXT WEEK...ALTHOUGH
THEY ARE PREDICTED TO BE A LITTLE WARMER AS THE UPPER LOW FADES
AWAY. ALONG WITH THE WIDESPREAD RAINFALL POTENTIAL FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK...WILDFIRE BURN SCARS COULD BE SUBJECTED
TO REPEATED RAINFALL...SOME POSSIBLY HEAVY AT TIMES.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1041 AM CDT THU JUL 11 2013
.UPDATE...
ISSUED AT 1006 AM CDT THU JUL 11 2013
ENHANCED CLOUDS AND ISOLATED SHOWERS ARE MOVING INTO THE FAR
WESTERN COUNTIES AND OPTED FOR SLIGHT CHANCE POPS THROUGH THE
AFTERNOON. THE MAIN ACTIVITY...WITH SOME SEVERE STORMS...STILL
EXPECTED TO HOLD OFF UNTIL AFTER 00Z.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CDT THU JUL 11 2013
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER SOUTHERN MINNESOTA AND
IOWA WITH LOW PRESSURE IN THE LEE OF THE ROCKIES. SOUTH/SOUTHEAST
SURFACE WINDS ACROSS THE REGION WAS ALLOWING INCREASING LOW LEVEL
MOISTURE WITH DEWPOINTS IN THE UPPER 50S TO MID 60S. MESOANALYSIS
INDICATES A LOW LEVEL JET HAD DEVELOPED FROM THE SOUTHERN PLAINS
INTO THE WESTERN DAKOTAS. THE LEADING EDGE OF THE JET...WITH
INCREASING SOUTHEAST WINDS AND DEWPOINTS WAS PROVIDING ENOUGH LIFT
FOR MID-LEVEL CLOUD DEVELOPMENT SEEN ON SATELLITE PICS EXTENDING
FROM NEAR DICKINSON TO MOBRIDGE TO SOUTH CENTRAL SOUTH DAKOTA.
REGIONAL RADARS PICKING UP ON SMALL CELLS TRYING TO DEVELOP IN THIS
LINE IN SOUTH DAKOTA - IN THE PAST HOUR OR TWO THE SMALL CELLS BEGIN
TO DEVELOP AND THEN DISSIPATE. AFTER 2 AM A CELL NEAR PIERRE WAS
BECOMING MORE ROBUST WITH DBZ VALUES ABOVE 50. THE HRRR 1KM
REFLECTIVITY DEPICTED THIS CONVECTION - AND KEEPS MOST OF IT MAINLY
IN SOUTH DAKOTA THIS MORNING...BUT INDICATES THE POTENTIAL IN SOUTH
CENTRAL NORTH DAKOTA TOWARDS DAYBREAK. HIGH EFFECTIVE BULK SHEAR AND
1000-2000 J/KG CAPE IN SOUTHWESTERN NORTH DAKOTA...MID-LEVEL LAPSE
RATES ARE HIGHER IN SOUTH CENTRAL AND WESTERN SOUTH DAKOTA...BUT
POTENTIAL FOR SOME CELLS THIS MORNING - WILL ADD A MENTION OF SLIGHT
CHC OF THUNDERSTORMS THIS MORNING.
AS TIME GOES ON TODAY...THE MID LEVEL CAP IS FORECAST TO
STRENGTHEN...WITH H700 TEMPERATURES AS PER THE NAM RISING TO +10C IN
THE DEVILS LAKE/JAMES RIVER BASINS BY NOON...AND TO +14C IN THE FAR
SOUTHWEST. THIS CAP SHOULD ACT TO KEEP SKIES CLEAR AND FREE OF
CONVECTION DURING THE DAYTIME. MEANWHILE DEWPOINT TEMPERATURES IN
THE 60S TO NEAR 70 WILL MAKE FOR A VERY WARM/HOT AND HUMID DAY
ACROSS THE FORECAST AREA TODAY.
THIS EVENING...THE LEADING EDGE OF UPPER LEVEL SHORTWAVE ENERGY
REACHES THE WESTERN ND BORDER IN THE SOUTHWEST FLOW ALOFT. AT THE
SURFACE...IN RESPONSE THE LEE-SIDE LOW PRESSURE TROUGH MOVES/DEVELOPS
EASTWARD AND REACHES THE WESTERN DAKOTAS EARLY EVENING. THE QUESTION
IS WHETHER THE UPPER LEVEL SHORTWAVE ENERGY WILL DISTURB THE
MID-LEVEL THERMAL CAP TO ALLOW CONVECTION BY LATE AFTERNOON/EARLY
EVENING...OR WHETHER CONVECTION WILL BEGIN JUST BEFORE/AROUND SUNSET
WHEN THE MID-LEVEL CAP WOULD WEAKEN A BIT. FORECAST CAPE VALUES OF
1500-3000 J/KG AND 0-6KM BULK SHEAR ABOVE 45KTS THIS EVENING AND
LATE NIGHT WILL PROVIDE PLENTY OF INSTABILITY FOR THE MENTION OF
SEVERE THUNDERSTORM POSSIBILITIES. EASTERN MT/WY AND THE WESTERN
DAKOTAS ARE IN THE SPC DAY1 SLIGHT RISK FOR SEVERE THUNDERSTORMS.
KEPT THE CHANCE OF PRECIPITATION IN THE EVENING MAINLY IN THE WEST
AND NORTH CENTRAL...AND INCREASED CHANCES IN CENTRAL NORTH DAKOTA
AFTER MIDNIGHT TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 405 AM CDT THU JUL 11 2013
WE REMAIN IN A TYPICAL MID-SUMMER WEATHER PATTERN WITH THE UPPER
LEVEL JET STREAM NEAR THE NORTHERN PLAINS REGION THROUGH MUCH OF
THE LONG TERM FORECAST PERIOD...RESULTING IN PERIODS OF SHOWERS
AND THUNDERSTORMS FOR THE NEXT SEVERAL DAYS.
FRIDAY INTO FRIDAY NIGHT...SFC TROUGH BY 12Z FRIDAY WILL BE MOVING
EAST ACROSS CENTRAL NORTH DAKOTA. BY FRIDAY AFTERNOON...MODELS
POSITION THE SFC TROUGH FROM CENTRAL SOUTH DAKOTA NORTH-NORTHEAST
INTO NORTHEASTERN NORTH DAKOTA. THIS WILL PUT THE BEST CHANCES
FOR ACCUMULATING PRECIPITATION/STRONGER THUNDERSTORMS MAINLY EAST
OF HIGHWAY 83 WITH THE BETTER COVERAGE/CHANCES OVER THE JAMES
RIVER VALLEY INTO THE RED RIVER VALLEY AREA WITH MINIMAL
INSTABILITY OVER THE WESTERN HALF OF THE STATE THANKS TO DRY AIR
ADVECTION. MAINLY DRY OVER WEST AND CENTRAL NORTH DAKOTA FRIDAY
EVENING WITH WEAK SFC HIGH PRESSURE IN PLACE ACROSS THE CENTRAL
PART OF THE STATE. WE START TO SEE INCREASING CHANCES FOR
THUNDERSTORMS LATE FRIDAY NIGHT WEST WHERE ANOTHER AREA OF SURFACE
LOW PRESSURE ARRIVES FROM EASTERN MONTANA.
THIS SURFACE LOW...ALONG WITH MID LEVEL S/WV`S LIFTING NORTHEAST
THROUGH THE STATE...WILL BE THE FOCUS FOR DECENT THUNDERSTORM
CHANCES SATURDAY/SATURDAY NIGHT. STRONG TO SEVERE STORMS WILL BE
POSSIBLE GIVEN 1-2K J/KG OF MUCAPE AND 0-6KM SHEAR 35KTS OR
GREATER. THE DAY 3 SPC OUTLOOK HAS INCLUDED THE ENTIRE STATE OF ND
IN THE SLIGHT RISK FOR SEVERE WEATHER.
A QUIET PERIOD IS IN THE OFFING LATER SUNDAY THROUGH SUNDAY NIGHT
WITH HIGH PRESSURE BUILDING SOUTH ACROSS THE REGION. OPTED TO
MAINTAIN SLIGHT CHANCE POPS FOR NOW SUNDAY NIGHT IN CASE THE 00Z
GFS PROVES MORE CORRECT WHICH KEEPS HIGH PRESSURE MORE OVER
SOUTHERN CANADA. THE LAST FEW RUNS OF THE ECMWF BUILD THE SFC HIGH
OVER NORTH DAKOTA AND WOULD SUPPORT DRY WEATHER.
THE PARADE OF MID LEVEL WAVES CONTINUES...AND WILL MAINTAIN SOME
MENTION FOR THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL AVERAGE NORMAL THROUGH THE PERIOD...WITH HIGHS
IN THE 80S TO LOW/MID 90S...AND LOWS MID 50S TO THE UPPER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1006 AM CDT THU JUL 11 2013
THUNDERSTORM CHANCES WILL INCREASE AFTER 00Z THIS EVENING FROM
WEST TO EAST. CURRENTLY HAVE VCTS MENTIONS...AND WILL LIKELY
REFINE TIMING AT 18Z ISSUANCE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE/AVIATION...RP KINNEY
SHORT TERM...JV
LONG TERM...NH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
657 AM CDT THU JUL 11 2013
.UPDATE...
ISSUED AT 656 AM CDT THU JUL 11 2013
INHERITED FORECAST LOOKS GOOD. NO CHANGES BESIDES UPDATING THE
CURRENT OBS AND ADJUSTING HOURLY TRENDS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CDT THU JUL 11 2013
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER SOUTHERN MINNESOTA AND
IOWA WITH LOW PRESSURE IN THE LEE OF THE ROCKIES. SOUTH/SOUTHEAST
SURFACE WINDS ACROSS THE REGION WAS ALLOWING INCREASING LOW LEVEL
MOISTURE WITH DEWPOINTS IN THE UPPER 50S TO MID 60S. MESOANALYSIS
INDICATES A LOW LEVEL JET HAD DEVELOPED FROM THE SOUTHERN PLAINS
INTO THE WESTERN DAKOTAS. THE LEADING EDGE OF THE JET...WITH
INCREASING SOUTHEAST WINDS AND DEWPOINTS WAS PROVIDING ENOUGH LIFT
FOR MID-LEVEL CLOUD DEVELOPMENT SEEN ON SATELLITE PICS EXTENDING
FROM NEAR DICKINSON TO MOBRIDGE TO SOUTH CENTRAL SOUTH DAKOTA.
REGIONAL RADARS PICKING UP ON SMALL CELLS TRYING TO DEVELOP IN THIS
LINE IN SOUTH DAKOTA - IN THE PAST HOUR OR TWO THE SMALL CELLS BEGIN
TO DEVELOP AND THEN DISSIPATE. AFTER 2 AM A CELL NEAR PIERRE WAS
BECOMING MORE ROBUST WITH DBZ VALUES ABOVE 50. THE HRRR 1KM
REFLECTIVITY DEPICTED THIS CONVECTION - AND KEEPS MOST OF IT MAINLY
IN SOUTH DAKOTA THIS MORNING...BUT INDICATES THE POTENTIAL IN SOUTH
CENTRAL NORTH DAKOTA TOWARDS DAYBREAK. HIGH EFFECTIVE BULK SHEAR AND
1000-2000 J/KG CAPE IN SOUTHWESTERN NORTH DAKOTA...MID-LEVEL LAPSE
RATES ARE HIGHER IN SOUTH CENTRAL AND WESTERN SOUTH DAKOTA...BUT
POTENTIAL FOR SOME CELLS THIS MORNING - WILL ADD A MENTION OF SLIGHT
CHC OF THUNDERSTORMS THIS MORNING.
AS TIME GOES ON TODAY...THE MID LEVEL CAP IS FORECAST TO
STRENGTHEN...WITH H700 TEMPERATURES AS PER THE NAM RISING TO +10C IN
THE DEVILS LAKE/JAMES RIVER BASINS BY NOON...AND TO +14C IN THE FAR
SOUTHWEST. THIS CAP SHOULD ACT TO KEEP SKIES CLEAR AND FREE OF
CONVECTION DURING THE DAYTIME. MEANWHILE DEWPOINT TEMPERATURES IN
THE 60S TO NEAR 70 WILL MAKE FOR A VERY WARM/HOT AND HUMID DAY
ACROSS THE FORECAST AREA TODAY.
THIS EVENING...THE LEADING EDGE OF UPPER LEVEL SHORTWAVE ENERGY
REACHES THE WESTERN ND BORDER IN THE SOUTHWEST FLOW ALOFT. AT THE
SURFACE...IN RESPONSE THE LEE-SIDE LOW PRESSURE TROUGH MOVES/DEVELOPS
EASTWARD AND REACHES THE WESTERN DAKOTAS EARLY EVENING. THE QUESTION
IS WHETHER THE UPPER LEVEL SHORTWAVE ENERGY WILL DISTURB THE
MID-LEVEL THERMAL CAP TO ALLOW CONVECTION BY LATE AFTERNOON/EARLY
EVENING...OR WHETHER CONVECTION WILL BEGIN JUST BEFORE/AROUND SUNSET
WHEN THE MID-LEVEL CAP WOULD WEAKEN A BIT. FORECAST CAPE VALUES OF
1500-3000 J/KG AND 0-6KM BULK SHEAR ABOVE 45KTS THIS EVENING AND
LATE NIGHT WILL PROVIDE PLENTY OF INSTABILITY FOR THE MENTION OF
SEVERE THUNDERSTORM POSSIBILITIES. EASTERN MT/WY AND THE WESTERN
DAKOTAS ARE IN THE SPC DAY1 SLIGHT RISK FOR SEVERE THUNDERSTORMS.
KEPT THE CHANCE OF PRECIPITATION IN THE EVENING MAINLY IN THE WEST
AND NORTH CENTRAL...AND INCREASED CHANCES IN CENTRAL NORTH DAKOTA
AFTER MIDNIGHT TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 405 AM CDT THU JUL 11 2013
WE REMAIN IN A TYPICAL MID-SUMMER WEATHER PATTERN WITH THE UPPER
LEVEL JET STREAM NEAR THE NORTHERN PLAINS REGION THROUGH MUCH OF
THE LONG TERM FORECAST PERIOD...RESULTING IN PERIODS OF SHOWERS
AND THUNDERSTORMS FOR THE NEXT SEVERAL DAYS.
FRIDAY INTO FRIDAY NIGHT...SFC TROUGH BY 12Z FRIDAY WILL BE MOVING
EAST ACROSS CENTRAL NORTH DAKOTA. BY FRIDAY AFTERNOON...MODELS
POSITION THE SFC TROUGH FROM CENTRAL SOUTH DAKOTA NORTH-NORTHEAST
INTO NORTHEASTERN NORTH DAKOTA. THIS WILL PUT THE BEST CHANCES
FOR ACCUMULATING PRECIPITATION/STRONGER THUNDERSTORMS MAINLY EAST
OF HIGHWAY 83 WITH THE BETTER COVERAGE/CHANCES OVER THE JAMES
RIVER VALLEY INTO THE RED RIVER VALLEY AREA WITH MINIMAL
INSTABILITY OVER THE WESTERN HALF OF THE STATE THANKS TO DRY AIR
ADVECTION. MAINLY DRY OVER WEST AND CENTRAL NORTH DAKOTA FRIDAY
EVENING WITH WEAK SFC HIGH PRESSURE IN PLACE ACROSS THE CENTRAL
PART OF THE STATE. WE START TO SEE INCREASING CHANCES FOR
THUNDERSTORMS LATE FRIDAY NIGHT WEST WHERE ANOTHER AREA OF SURFACE
LOW PRESSURE ARRIVES FROM EASTERN MONTANA.
THIS SURFACE LOW...ALONG WITH MID LEVEL S/WV`S LIFTING NORTHEAST
THROUGH THE STATE...WILL BE THE FOCUS FOR DECENT THUNDERSTORM
CHANCES SATURDAY/SATURDAY NIGHT. STRONG TO SEVERE STORMS WILL BE
POSSIBLE GIVEN 1-2K J/KG OF MUCAPE AND 0-6KM SHEAR 35KTS OR
GREATER. THE DAY 3 SPC OUTLOOK HAS INCLUDED THE ENTIRE STATE OF ND
IN THE SLIGHT RISK FOR SEVERE WEATHER.
A QUIET PERIOD IS IN THE OFFING LATER SUNDAY THROUGH SUNDAY NIGHT
WITH HIGH PRESSURE BUILDING SOUTH ACROSS THE REGION. OPTED TO
MAINTAIN SLIGHT CHANCE POPS FOR NOW SUNDAY NIGHT IN CASE THE 00Z
GFS PROVES MORE CORRECT WHICH KEEPS HIGH PRESSURE MORE OVER
SOUTHERN CANADA. THE LAST FEW RUNS OF THE ECMWF BUILD THE SFC HIGH
OVER NORTH DAKOTA AND WOULD SUPPORT DRY WEATHER.
THE PARADE OF MID LEVEL WAVES CONTINUES...AND WILL MAINTAIN SOME
MENTION FOR THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL AVERAGE NORMAL THROUGH THE PERIOD...WITH HIGHS
IN THE 80S TO LOW/MID 90S...AND LOWS MID 50S TO THE UPPER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 656 AM CDT THU JUL 11 2013
MAINLY CLEAR SKIES FOR THIS TAF ISSUANCE. THE ONLY EXCEPTION IS A
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS THAT HAD FORMED ALONG THE
EASTERN EDGE OF A LOW LEVEL JET AND WERE MOVING
EASTWARD/NORTHEASTWARD. AT THIS TIME NONE OF THE CONVECTIVE CELLS
APPEARS TO THREATEN ANY OF THE TAF SITES...THOUGH ONE CELL DEVELOPED
OVER KBIS BUT WAS MOVING AWAY FROM KBIS.
SOUTHEAST WINDS TO INCREASE AFT 15Z AND ESPECIALLY AFT 18Z. THE
CHANCE OF THUNDERSTORMS IS MAINLY AFT 00Z AND HAVE VCTS MENTIONED AT
KISN/KDIK/KMOT AFT 00Z...AND AT KBIS AFT 06Z AND AFT 09Z AT KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
405 AM CDT THU JUL 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CDT THU JUL 11 2013
CURRENTLY...SURFACE HIGH PRESSURE WAS OVER SOUTHERN MINNESOTA AND
IOWA WITH LOW PRESSURE IN THE LEE OF THE ROCKIES. SOUTH/SOUTHEAST
SURFACE WINDS ACROSS THE REGION WAS ALLOWING INCREASING LOW LEVEL
MOISTURE WITH DEWPOINTS IN THE UPPER 50S TO MID 60S. MESOANALYSIS
INDICATES A LOW LEVEL JET HAD DEVELOPED FROM THE SOUTHERN PLAINS
INTO THE WESTERN DAKOTAS. THE LEADING EDGE OF THE JET...WITH
INCREASING SOUTHEAST WINDS AND DEWPOINTS WAS PROVIDING ENOUGH LIFT
FOR MID-LEVEL CLOUD DEVELOPMENT SEEN ON SATELLITE PICS EXTENDING
FROM NEAR DICKINSON TO MOBRIDGE TO SOUTH CENTRAL SOUTH DAKOTA.
REGIONAL RADARS PICKING UP ON SMALL CELLS TRYING TO DEVELOP IN THIS
LINE IN SOUTH DAKOTA - IN THE PAST HOUR OR TWO THE SMALL CELLS BEGIN
TO DEVELOP AND THEN DISSIPATE. AFTER 2 AM A CELL NEAR PIERRE WAS
BECOMING MORE ROBUST WITH DBZ VALUES ABOVE 50. THE HRRR 1KM
REFLECTIVITY DEPICTED THIS CONVECTION - AND KEEPS MOST OF IT MAINLY
IN SOUTH DAKOTA THIS MORNING...BUT INDICATES THE POTENTIAL IN SOUTH
CENTRAL NORTH DAKOTA TOWARDS DAYBREAK. HIGH EFFECTIVE BULK SHEAR AND
1000-2000 J/KG CAPE IN SOUTHWESTERN NORTH DAKOTA...MID-LEVEL LAPSE
RATES ARE HIGHER IN SOUTH CENTRAL AND WESTERN SOUTH DAKOTA...BUT
POTENTIAL FOR SOME CELLS THIS MORNING - WILL ADD A MENTION OF SLIGHT
CHC OF THUNDERSTORMS THIS MORNING.
AS TIME GOES ON TODAY...THE MID LEVEL CAP IS FORECAST TO
STRENGTHEN...WITH H700 TEMPERATURES AS PER THE NAM RISING TO +10C IN
THE DEVILS LAKE/JAMES RIVER BASINS BY NOON...AND TO +14C IN THE FAR
SOUTHWEST. THIS CAP SHOULD ACT TO KEEP SKIES CLEAR AND FREE OF
CONVECTION DURING THE DAYTIME. MEANWHILE DEWPOINT TEMPERATURES IN
THE 60S TO NEAR 70 WILL MAKE FOR A VERY WARM/HOT AND HUMID DAY
ACROSS THE FORECAST AREA TODAY.
THIS EVENING...THE LEADING EDGE OF UPPER LEVEL SHORTWAVE ENERGY
REACHES THE WESTERN ND BORDER IN THE SOUTHWEST FLOW ALOFT. AT THE
SURFACE...IN RESPONSE THE LEE-SIDE LOW PRESSURE TROUGH MOVES/DEVELOPS
EASTWARD AND REACHES THE WESTERN DAKOTAS EARLY EVENING. THE QUESTION
IS WHETHER THE UPPER LEVEL SHORTWAVE ENERGY WILL DISTURB THE
MID-LEVEL THERMAL CAP TO ALLOW CONVECTION BY LATE AFTERNOON/EARLY
EVENING...OR WHETHER CONVECTION WILL BEGIN JUST BEFORE/AROUND SUNSET
WHEN THE MID-LEVEL CAP WOULD WEAKEN A BIT. FORECAST CAPE VALUES OF
1500-3000 J/KG AND 0-6KM BULK SHEAR ABOVE 45KTS THIS EVENING AND
LATE NIGHT WILL PROVIDE PLENTY OF INSTABILITY FOR THE MENTION OF
SEVERE THUNDERSTORM POSSIBILITIES. EASTERN MT/WY AND THE WESTERN
DAKOTAS ARE IN THE SPC DAY1 SLIGHT RISK FOR SEVERE THUNDERSTORMS.
KEPT THE CHANCE OF PRECIPITATION IN THE EVENING MAINLY IN THE WEST
AND NORTH CENTRAL...AND INCREASED CHANCES IN CENTRAL NORTH DAKOTA
AFTER MIDNIGHT TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 405 AM CDT THU JUL 11 2013
WE REMAIN IN A TYPICAL MID-SUMMER WEATHER PATTERN WITH THE UPPER
LEVEL JET STREAM NEAR THE NORTHERN PLAINS REGION THROUGH MUCH OF
THE LONG TERM FORECAST PERIOD...RESULTING IN PERIODS OF SHOWERS
AND THUNDERSTORMS FOR THE NEXT SEVERAL DAYS.
FRIDAY INTO FRIDAY NIGHT...SFC TROUGH BY 12Z FRIDAY WILL BE MOVING
EAST ACROSS CENTRAL NORTH DAKOTA. BY FRIDAY AFTERNOON...MODELS
POSITION THE SFC TROUGH FROM CENTRAL SOUTH DAKOTA NORTH-NORTHEAST
INTO NORTHEASTERN NORTH DAKOTA. THIS WILL PUT THE BEST CHANCES
FOR ACCUMULATING PRECIPITATION/STRONGER THUNDERSTORMS MAINLY EAST
OF HIGHWAY 83 WITH THE BETTER COVERAGE/CHANCES OVER THE JAMES
RIVER VALLEY INTO THE RED RIVER VALLEY AREA WITH MINIMAL
INSTABILITY OVER THE WESTERN HALF OF THE STATE THANKS TO DRY AIR
ADVECTION. MAINLY DRY OVER WEST AND CENTRAL NORTH DAKOTA FRIDAY
EVENING WITH WEAK SFC HIGH PRESSURE IN PLACE ACROSS THE CENTRAL
PART OF THE STATE. WE START TO SEE INCREASING CHANCES FOR
THUNDERSTORMS LATE FRIDAY NIGHT WEST WHERE ANOTHER AREA OF SURFACE
LOW PRESSURE ARRIVES FROM EASTERN MONTANA.
THIS SURFACE LOW...ALONG WITH MID LEVEL S/WV`S LIFTING NORTHEAST
THROUGH THE STATE...WILL BE THE FOCUS FOR DECENT THUNDERSTORM
CHANCES SATURDAY/SATURDAY NIGHT. STRONG TO SEVERE STORMS WILL BE
POSSIBLE GIVEN 1-2K J/KG OF MUCAPE AND 0-6KM SHEAR 35KTS OR
GREATER. THE DAY 3 SPC OUTLOOK HAS INCLUDED THE ENTIRE STATE OF ND
IN THE SLIGHT RISK FOR SEVERE WEATHER.
A QUIET PERIOD IS IN THE OFFING LATER SUNDAY THROUGH SUNDAY NIGHT
WITH HIGH PRESSURE BUILDING SOUTH ACROSS THE REGION. OPTED TO
MAINTAIN SLIGHT CHANCE POPS FOR NOW SUNDAY NIGHT IN CASE THE 00Z
GFS PROVES MORE CORRECT WHICH KEEPS HIGH PRESSURE MORE OVER
SOUTHERN CANADA. THE LAST FEW RUNS OF THE ECMWF BUILD THE SFC HIGH
OVER NORTH DAKOTA AND WOULD SUPPORT DRY WEATHER.
THE PARADE OF MID LEVEL WAVES CONTINUES...AND WILL MAINTAIN SOME
MENTION FOR THUNDERSTORMS THROUGH THE MIDDLE OF NEXT WEEK.
TEMPERATURES WILL AVERAGE NORMAL THROUGH THE PERIOD...WITH HIGHS
IN THE 80S TO LOW/MID 90S...AND LOWS MID 50S TO THE UPPER 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1243 AM CDT THU JUL 11 2013
MAINLY CLEAR SKIES FOR THIS TAF ISSUANCE. THE ONLY EXCEPTION IS A
TEMPO FROM 09Z-13Z FOR THE POSSIBILITY OF LIGHT FOG FORMATION.
SOUTHEAST WINDS TO INCREASE AFT 15Z AND ESPECIALLY AFT 18Z. THE
CHANCE OF THUNDERSTORMS IS MAINLY AFT 00Z AND HAVE VCTS MENTIONED AT
KISN/KDIK/KMOT AFT 00Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
745 PM EDT FRI JUL 12 2013
.SYNOPSIS...
UPPER LOW DRIFT WEST TONIGHT INTO SATURDAY...PULLING DEEPER
MOISTURE INTO THE AREA. SOME MOISTURE REMAINS AS A HIGH AND WARM
TEMPS SET UP FOR NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
UPDATED POPS AND HOURLY TEMPERATURES. USED THE HRRR HI RES MODEL
PER SIMILARITIES ON RADAR IMAGES. STORMS COULD BE SEVERE NEAR
KANAWHA COUNTY. STORMS ARE MOVING SLOWLY WEST AROUND 5 MPH. THIS
WILL PRODUCE FLASH FLOODING OF CREEKS...SMALL STREAMS AND LOW
LYING AREAS ACROSS ROANE...PUTNAM AND KANAWHA COUNTY.
PREVIOUS DISCUSSION BELOW...
UPPER LOW OVER THE AREA TODAY AND TONIGHT...WITH A MOIST NE TO
EAST FLOW ACROSS THE CWA. CONVECTION FORMED OVER THE CENTRAL
MOUNTAINS THIS MORNING IN THE EASTERLY FLOW...AND HAS BEEN ONGOING
FOR MUCH OF THE DAY. POPS WILL GRADUALLY INCREASE IN COVERAGE AS
THE DAY PROGRESSES...AND AFTERNOON PEAK HEATING GETS INTO FULL
SWING. MAINTAINED HIGH CHANCE TO LIKELY POPS ACROSS THE
NORTH...WITH CHANCE TO SLIGHT CHANCE OF POPS ACROSS THE SOUTH AND
WEST. AT THIS POINT STILL NOT OVERLY CONCERNED ABOUT WATER ISSUES.
12Z RNK SOUNDING INDICATED PW VALUES AT 1.08 INCHES...AND SO FAR
PRECIPITATION FROM ANY ACTIVITY HAS BEEN GENERALLY LIGHT.
BULK OF CONVECTIVE ACTIVITY WILL TAPER OFF ACROSS THE AREA TONIGHT
WITH THE LOSS OF HEATING...BUT WILL CONTINUE TO MAINTAIN A SLIGHT
CHANCE ACROSS THE MOUNTAINS...PARTICULARLY NORTHERN MOUNTAIN ZONES.
IN ADDITION...SCATTERED CU FIELD SHOULD MOSTLY CLEAR OUT ACROSS THE
WEST AND SOUTH...BUT THINKING CLOUD COVER WILL HANG ON ACROSS THE
HIGHER TERRAIN COUNTIES OVERNIGHT.
UPPER LOW WILL BEGIN TO PUSH OFF TO THE SOUTH AND EAST LATER TONIGHT
AND ON SATURDAY...AS UPPER LEVEL RIDGE NUDGES IN FROM THE EAST. THIS
WILL LEAD TO A TREND OF WARMER TEMPERATURES...AND SOMEWHAT DRIER
WEATHER...ALTHOUGH SHOWERS AND STORMS WILL CONTINUE PARTICULARLY
DURING THE PEAK HEATING HOURS. MADE NO MAJOR CHANGES TO THE PREVIOUS
TEMPERATURE FORECAST OTHER THAN MINOR TWEAKS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW WILL CONTINUE TO DRIFT SOUTH AND WEST DUE TO A
FAIRLY STRONG HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE EAST.
STILL EXPECT DIURNAL SHOWERS AND THUNDERSTORM THROUGH THE PERIOD
WITH TEMPERATURE BEGINNING TO WARM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
SUMMER PATTERN CONTINUES WITH A 598/599 MB HIGH OVER THE AREA. EVEN
THOUGH THE FORECAST AREA HAS BEEN WET IT WON/T TAKE LONG TO DRY OUT
BEING JULY. EXPECT WARM TEMPERATURES FOR THE FORECAST
AREA...POSSIBLE THE WARMEST TEMPERATURES SO FAR THIS SUMMER. RAISED
AFTERNOON HIGHS AND DEW POINTS. THERE WILL STILL BE MOISTURE AROUND
THE AREA TRAPPED UNDER THE HIGH THUS DIURNAL POPS. THE RIDGE BEGINS
TO FLATTEN OUT ON THURSDAY AND FRIDAY AS THE NEXT FRONTAL SYSTEM
APPROACHES THE OHIO VALLEY BY FRIDAY. TIMING WITH THE FRONT IS
STILL IFFY AS IT IS SEVEN DAYS OUT.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
IFR CONDITIONS POSSIBLE EARLY THIS EVENING UNDER STRONG STORMS
WITH PEA TO QUARTERS SIZE HAIL ALONG THEIR PATH MAINLY AT AND
NEARBY CRW. OTHER SITES LIKE CKB...AND PKB WILL EXPERIENCE MVFR
CONDITIONS UNDER LIGHT TO MODERATE RAIN. THESE CONDITIONS WILL
LAST AT LEAST THROUGH 03Z.
A BRIEF RETURN TO MAINLY VFR CONDITIONS MANY AREAS IS EXPECTED
AFTER 03Z. HOWEVER...MVFR/IFR LOW STRATUS WILL DEVELOP OVERNIGHT
PER CALM FLOW AND ABUNDANT LOW LEVEL MOISTURE. PATCHY MVFR/IFR
FOG POSSIBLE ACROSS MUCH OF LOWLANDS...PARTICULARLY IN AREAS THAT
RECEIVE RAIN DURING THE AFTERNOON AND EVENING HOURS.
THE BROAD UPPER LOW IS RESPONSIBLE FOR THE FORCING AND THE
AFTERNOON HEATING WERE RESPONSIBLE FOR THIS CONVECTION ACTIVITY.
EXPECT CONVECTION TO DIMINISH IN INTENSITY AFTER 03Z.
WIDESPREAD 1500 TO 1200 CEILINGS COULD DEVELOP DURING THE PREDAWN
HOURS. HOWEVER...THE BROAD UPPER LOW PRESSURE WILL LIKELY DRIFT
WEST...BRINGING MID TO UPPER LEVEL CLOUDS OVER THE AREA PREVENTING
FOG AND LOW CEILINGS...MAINLY ACROSS THE NORTHEAST QUADRANT OF OUR
CWA.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z SUNDAY...
FORECAST CONFIDENCE...MEDIUM.
ALTERNATE SCENARIOS: TIMING AND INTENSITY OF IFR CEILINGS OR FOG
AS WELL AS LOW CEILINGS COULD BE DIFFERENT THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 07/13/13
UTC 1HRLY 00 01 02 03 04 05 06 07 08 09 10 11
EDT 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
CRW CONSISTENCY H H H H H M M H H H H H
HTS CONSISTENCY H H H H H M M H H H H H
BKW CONSISTENCY H H M M M M M H H L L L
EKN CONSISTENCY H H H H H M M L L L L L
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z SUNDAY...
IFR IN FOG POSSIBLE SATURDAY NIGHT. BRIEF IFR IN THUNDERSTORMS OVER THE
WEEKEND.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...FB/SL
NEAR TERM...ARJ/SL
SHORT TERM...RPY
LONG TERM...FB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS TULSA OK
1215 AM CDT THU JUL 11 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES
FOR THE ENTIRE 24 HOUR FORECAST PERIOD. ONGOING ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS THE REGION ARE NOT EXPECTED TO AFFECT ANY
OF OUR SITES.
&&
.PREV DISCUSSION... /ISSUED 942 PM CDT WED JUL 10 2013/
DISCUSSION...
STORMS LINGERING FROM THE AFTERNOON OVER WEST CENTRAL AR ARE ON
THE DECLINE DUE TO THE LOSS OF SOLAR HEATING. ONCE THIS ACTIVITY
DIES OFF...THE REMAINDER OF THE NIGHT SHOULD BE MAINLY QUIET.
TOWARD 12Z...THE LATEST RUN OF THE HRRR SUGGESTS WE COULD SEE SOME
HIGH BASED ACCAS SHOWERS AND STORMS...MUCH LIKE THIS MORNING.
UPDATED TEXT PRODUCTS ARE OUT.
LACY
PREV DISCUSSION... /ISSUED 605 PM CDT WED JUL 10 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 0Z TAFS... VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES
FOR THE ENTIRE 24 HOUR FORECAST PERIOD. ONGOING WIDELY SCATTERED
THUNDERSTORMS WILL CONTINUE ACROSS THE REGION INTO THIS EVENING.
WILL INCLUDE VCTS AT ALL SITES AND WILL USE A TEMPO GROUP FOR
KMLC... WHICH APPEARS LIKELY TO BE AFFECTED BY A STORM OVER THE
NEXT HOUR OR SO.
PREV DISCUSSION... /ISSUED 311 PM CDT WED JUL 10 2013/
DISCUSSION...
ANOTHER HOT DAY WELL UNDERWAY ACROSS EASTERN OKLAHOMA AND
NORTHWEST ARKANSAS EVEN AS A COLD FRONT HAS MOVED INTO THE
AREA. THE COLD FRONT CURRENTLY EXTENDS FROM NEAR KSTL TO
NEAR KRVS WITH ANOTHER WEAK TROF OF LOW PRESSURE ACROSS
NORTHWEST ARKANSAS. SHOWERS AND A FEW THUNDERSTORMS HAVE DEVELOPED
THIS AFTERNOON IN THE VICINITY OF THE FRONTAL BOUNDARY. THE CHANCES
OF SHOWERS AND THUNDERSTORMS WILL CONTINUE NEAR THE BOUNDARY INTO
THIS EVENING. THERE IS ALSO SOME POTENTIAL FOR THE ACTIVITY TO
CONTINUE INTO THE OVERNIGHT HOURS. THERE IS THE POTENTIAL FOR
SOME OF THE STORMS TO BECOME SEVERE LATE THIS AFTERNOON AND EVENING
WITH WIND GUSTS APPROACHING 80 MPH WITH THE STRONGEST STORMS.
WILL TRIM SOME COUNTIES OFF OF THE HEAT ADVISORY AND LET THE
EXCESSIVE HEAT WARNING FOR TULSA COUNTY EXPIRE AT 01Z. WILL KEEP
THE COUNTIES SOUTH OF THE BOUNDARY IN A HEAT ADVISORY THAT WILL
CONTINUE THROUGH THURSDAY AFTERNOON. MAY SEE ISOLATED SHOWERS
AND THUNDERSTORMS ACROSS THE AREA ON THURSDAY AS THE BOUNDARY
LINGERS.
WILL KEEP THE FORECAST FROM FRIDAY INTO THE MIDDLE OF NEXT
WEEK DRY WITH TEMPERATURES AT OR SLIGHTLY ABOVE NORMAL FOR
THIS TIME OF YEAR. THE MODELS CONTINUE TO SHOW THE UPPER LEVEL
LOW CURRENTLY AFFECTING SOUTH FLORIDA MOVING WEST ACROSS SOUTH
TEXAS OVER THE WEEKEND SHOVING THE UPPER LEVEL RIDGE CURRENTLY
OVER OUR AREA TO THE NORTH. THE UPPER LEVEL LOW LOOKS TO BE TOO
FAR SOUTH TO BRING ANY SHOWER OR THUNDERSTORMS TO THE AREA.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 7 PM THURSDAY FOR OKZ049-OKZ053-OKZ064-
OKZ065-OKZ066-OKZ070-OKZ071-OKZ073-OKZ074-OKZ075-OKZ076.
AR...NONE.
&&
$$
SHORT TERM...99
LONG TERM....99
AVIATION...06
AREA FORECAST DISCUSSION
NWS NORMAN OK
1146 PM CDT WED JUL 10 2013
.AVIATION...06Z TAF ISSUANCE...
RAIN AND THUNDER HAS CEASED FOR THE TIME BEING THIS EVENING
ACROSS OK AND WRN N TX. TO THE NW...SHOWERS AND THUNDERSTORMS
CONTINUE ACROSS FAR SERN CO AND SWRN KS. THIS ACTIVITY HAS BEEN
SLOWLY DIMINISHING THIS EVENING...BUT MAY SKIRT NWRN AND NRN
OK...IMPACTING KGAG AND KWWR. HOWEVER...FOR THE MOMENT...HAVE
DECIDED TO LEAVE ANY MENTION OF SHRA OR TSRA OUT OF THE TAFS.
OVERALL...EXPECT VFR CONDITIONS TO PERSIST...WITH MID TO HIGH
DECK OF SCT TO BKN STRATUS/STRATOCU SPREADING ACROSS THE REGION.
S/SE WINDS WILL CONTINUE TO CALM OVERNIGHT AS THE FRONT SETTLES
ACROSS THE REGION. WINDS WILL SHIFT OUT OF THE E/SE THROUGH
DAYBREAK...INCREASING SLIGHTLY THROUGH THE AFTERNOON.
JTK
&&
.PREV DISCUSSION... /ISSUED 849 PM CDT WED JUL 10 2013/
UPDATE...
UPDATED POPS THROUGH 06Z
DISCUSSION...
STORMS HAVE SLOWLY WEAKENED OVER THE PAST TWO HOURS...WITH
ISOLATED SHOWERS/THUNDER REMAINING ACROSS FAR NWRN OK. TRIMMED
BACK POPS ACROSS CENTRAL OK TO ACCOUNT FOR THIS. TO THE NW...A
DECENT MCS HAS STARTED TO DEVELOP ACROSS SERN CO AND FAR SWRN KS
THIS EVENING. THIS ACTIVITY IS EXPECTED TO SLOWLY MOVE S/SE
THROUGH THE EVENING AND OVERNIGHT.
FAR NWRN AND NRN OK WILL HAVE THE GREATEST CHANCES FOR
PRECIPITATION AS WILL THE PANHANDLES...AS CONDITIONS ARE LESS
FAVORABLE ACROSS CENTRAL AND SRN OK INTO WRN N TX FOR MCS
MAINTENANCE. MUCAPE IN THE 1000-500MB LAYER IS PALTRY...ACROSS
CENTRAL AND WRN OK...600 TO 1000 J/KG OVERNIGHT. THIS SCENARIO IS
SUPPORTED BY HRRR WITH OVERALL CONVECTION WEAKENING OVERNIGHT
ACROSS MUCH OF OKLAHOMA. HOWEVER...THERE REMAINS A CHANCE FOR
SCATTERED SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THE AREA
THROUGH SUNRISE AS THE WEAK BOUNDARY/FRONT REMAINS POSITIONED E/W
ACROSS THE STATE.
JTK
PREV DISCUSSION... /ISSUED 343 PM CDT WED JUL 10 2013/
DISCUSSION...
THE MAIN STORY FOR THE REMAINDER OF THE WEEK WILL BE DANGEROUS
HEAT...WHICH WILL LAST THROUGH AT LEAST FRIDAY.
FOR THE REMAINDER OF TODAY...ISOLATED TO WIDELY SCATTERED STORMS
HAVE DEVELOPED ALONG A WEAK SFC FRONT/OUTFLOW BOUNDARY OVER NORTH
CENTRAL OKLAHOMA. ADDITIONAL ACTIVITY IS EXPECTED TO FORM ACROSS
WESTERN KS INTO WEST TX THROUGH THIS EVENING...POTENTIALLY MOVING
INTO FAR NORTHWEST OKLAHOMA THROUGH 03Z. WHILE LITTLE TO NO WIND
SHEAR IS PRESENT...PULSE VARIETY THUNDERSTORMS ARE EXPECTED. WITH
LARGE TEMPERATURE DEWPOINT SPREADS...EXPECT THE STRONGEST STORMS
MAY PRODUCE DAMAGING DOWNBURST WINDS OF 60 TO 70 MPH. THOUGH GUSTY
WINDS WILL BE LIKELY NEAR ANY STORM THAT DEVELOPS. OUTSIDE OF RAIN
COOLED AREAS...TEMPERATURES WILL HOVER AROUND 100 DEGREES THROUGH
THE EVENING...WITH GRADUAL COOLING BY MIDNIGHT. MOST SHOWER/STORM
ACTIVITY WILL HAVE ENDED BY THIS TIME.
THOUGH TEMPERATURES MAY COME IN A BIT COOLER BOTH TOMORROW AND
FRIDAY THAN TODAY...COMBINATION OF INCREASING LOW LEVEL MOISTURE
AND AFTERNOON HIGHS NEAR 100 DEGREES WILL LEAD TO DANGEROUS HEAT.
HEAT INDICES BOTH TOMORROW AND FRIDAY WILL TOP OUT BETWEEN 103 AND
110 DEGREES...WITH OVERNIGHT LOWS ONLY FALLING TO AROUND 80
DEGREES. WITH THIS IN MIND...HAVE OPTED TO EXTEND THE HEAT
ADVISORY BOTH IN AREA AND TIME TO COVER MUCH OF CENTRAL AND
SOUTHERN OKLAHOMA. PLEASE FOLLOW HEAT SAFETY MEASURES THROUGH THE
REMAINDER OF THE WEEK...AS THESE CONDITIONS CAN PROVE FATAL IF NOT
ADDRESSED PROPERLY.
BY THIS WEEKEND...A BROAD UPPER TROUGH WILL MOVE FROM EAST TO
WEST ALONG THE NRN GULF COAST. THIS SHOULD BRING HEIGHTS DOWN A
BIT...LEADING TO SLIGHTLY LESS HOT CONDITIONS FROM THE WEEKEND
INTO NEXT WEEK. THOUGH AFTERNOON HIGHS WILL GENERALLY REMAIN IN
THE 93 TO 100 DEGREE RANGE. WITH WEAK UPPER FORCING ALOFT...AND
IMPROVING DEEP MOISTURE...EXPECT THIS FEATURE MAY ALSO LEAD TO
ISOLATED SHOWER AND THUNDERSTORM ACTIVITY OVER SOUTHERN PORTIONS
OF OKLAHOMA AND NORTH TEXAS FOR THE EARLY TO MIDDLE PART OF NEXT
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 101 77 99 75 / 20 30 20 20
HOBART OK 102 79 103 76 / 10 20 20 10
WICHITA FALLS TX 104 79 104 77 / 10 10 20 20
GAGE OK 99 75 98 74 / 30 60 10 10
PONCA CITY OK 100 77 95 72 / 30 30 20 10
DURANT OK 102 77 100 76 / 10 20 20 20
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 7 AM CDT SATURDAY FOR OKZ007-008-012-013-
018>020-024>032-039>043-045>048-050>052.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1159 PM EDT FRI JUL 12 2013
.SYNOPSIS...
A CUT OFF UPPER LOW OVER THE OHIO RIVER VALLEY WILL DRIFT
INTO THE LOWER MISSISSIPPI VALLEY THIS WEEKEND. THE SOUTHERLY FLOW
TO THE EAST OF THIS FEATURE WILL CONTINUE TO BRING MOISTURE AND
SCATTERED SHOWERS TO PENNSYLVANIA FOR THE NEXT FEW DAYS. THE
TEMPERATURES WILL BE CLIMBING NEXT WEEK AS AN UNUSUALLY STRONG
UPPER LEVEL RIDGE FORMS OVERHEAD.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
EARLIER CONVECTION HAS BECOME JUST ANOTHER BAND OF STEADIER-
MODERATE RAIN. AREA OF CONCERN IS NOW EASTERN LANCASTER CO WHERE
THE OCTORARO CREEK VALLEY MAY HAVE PICKED UP MORE THAN AN INCH OF
RAIN IN THE LAST FEW HOURS. FFG IS FAIRLY LOW THERE VS THE REST OF
THE LAND...SO HAVE PUT A FLOOD ADVISORY OUT TO HEIGHTEN AWARENESS.
LACK OF REPORTS OF FLOODING FROM THE COUNTY DISPATCH CENTER AND
VERY LOW PRECIP NUMBERS FROM THE REST OF THE COUNTY LEAD US TO
THINK THAT ANY FLOODING THERE WOULD BE MINOR/NUISANCE TYPE.
OTHERWISE..BUMPED POPS UP FOR THE BALANCE OF THE AREA. THE
CIRCULATION OVER ERN MD AND DE IS HOLDING FAIRLY STILL RIGHT NOW.
NEAR TERM RUC MODEL PORTRAYS A SLOW BREAK UP OF THE SHOWERS AS DRY
AIR APPEARS TO WRAP ALL THE WAY AROUND FROM THE NW/WEST AND IN
FROM THE EAST. REST IS UNCHANGED.
8 PM UPDATE...
LATEST TRENDS IN SENSIBLE WEATHER ARE THE DEVELOPMENT OF
CONVECTION - SANS THUNDER - ALONG THE LEADING EDGE/OUTFLOW OF A
SHIELD OF STRATIFORM PRECIP. THE COOLER AIR IS PROBABLY LIFTING
THE HIGHER CAPE AIR IN THE WARMEST AREAS OF THE CWA...AND POPPING
THE SHOWERS. ACCORDING TO IFLOWS AND OTHER AUTOMATED GAGES AND THE
RADAR PRECIP ESTIMATES...THE PRECIP IS VERY LIGHT COMPARED TO
LOCAL FFG. THIS MEANS FLOODING SHOULD NOT BE A CONCERN THIS
EVENING. POPS AND WX GRIDS IN GREAT SHAPE. ONLY THE MOST MINOR OF
TWEAKS HAVE BEEN MADE WITH THIS UPDATE.
PREVIOUS DISC...
CURRENT 88D MOSAIC CONTINUES TO SHOW A PERSISTENT...SLOW MOVING
AREA OF LIGHT TO MODERATE RAIN ACROSS THE FAR SE COUNTIES OF OUR
CWA.
THE RAIN WILL ADVANCE SLOWLY NWWD ACROSS TWD THE CENTRAL MTNS AND
MIDDLE SUSQ VALLEY LATE THIS AFTERNOON INTO TONIGHT AS SEVERAL
SPOKES OF VORTICITY AND FAVORABLE 825-700 MB FRONTOGENETIC FORCING
PIVOT WWD ACROSS THE FCST AREA...AND THE EASTERLY LLVL FLOW
PEAKS AROUND -4 SIGMA /AT 850 MB/ OVER SOUTHERN PENN THROUGH 00Z
SAT.
THE NWRN EDGE OF THE RAIN SHIELD WILL BE LIGHT FOR MUCH OF THE TIME
THIS AFTERNOON INTO TONIGHT.
RAINFALL OVER THE NEXT 12-16 HOURS WILL AVERAGE LESS THAN A TENTH
OF AN INCH NEAR...AND JUST TO THE SE OF A LINE FROM KIPT TO KUNV
AND KJST WITH VERY LIGHT OR NIL AMTS FURTHER TO THE NW. ACROSS THE
LOWER SUSQ VALLEY AND SCENT MTNS BENEATH THE NOSE OF THE POTENT
EASTERLY LLJ AND STRONGEST/MOST PERSISTENT LOW-MID LEVEL
DEFORMATION ZONES...ADDITIONAL RAINFALL SHOULD FALL INTO THE
0.20-0.30 INCH RANGE WITH HIGHLY LOCALIZED 0.50 INCH AMOUNTS
POSSIBLE WHERE ONE OR TWO SLOW-MOVING LOW TOPPED TSRA DEVELOP NEAR
THE MASON/DIXON LINE.
TEMPS LATE THIS AFTERNOON ACROSS THE CENTRAL AND NW ZONES
WILL BE MAINLY IN THE LOWER TO MID 70S. THE STEADY RAIN ACROSS THE
LOWER SUSQ VALLEY /AND SFC DEWPOINTS IN THE L-M 60S/ HAS CAPPED
TEMPS WELL BELOW NORMAL...AND COOLER THAN MOST OTHER PARTS OF THE
STATE.
ALTHOUGH THE AREAL COVERAGE OF THE LIGHT RAIN WILL INCREASE/EXPAND
TO THE NW TONIGHT...THE INTENSITY SHOULD LIGHTEN UP ACROSS THE SE
ZONES AS THE LLVL EASTERN FLOW WEAKENS AND THE UPPER LOW OVER THE
MID OHIO RIVER VALLEY RETROGRADES 200-300 KM TOWARD THE SW BY SAT
MORNING.
PERSISTENT EASTERLY FLOW OFF OF THE ATLANTIC...COMBINED WITH COOLING
BLYR...WILL LIKELY RESULT IN INCREASING/LOWERING STRATUS ACROSS THE
SOUTHEAST HALF OF PA AND THE LAUREL HIGHLANDS LATE TONIGHT...
WHILE A NON-PRECIPITATING...MID/HIGH CLOUD SHIELD WILL BLANKET
THE NW MTNS.
LOWS TONIGHT WILL VARY FROM 55 TO 60F ACROSS THE NRN AND WRN
MTNS...TO THE MID AND U60S IN THE SE VALLEYS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
PERSISTENT...MOIST EASTERLY FLOW OVR PA /WITH INCREASING PWATS/ WILL
LIKELY RESULT IN A MAINLY OVERCAST...HUMID AND OCNLY SHOWERY
SATURDAY. MOST OF THE SHOWERS WILL BE CONFINED TO THE CENTRAL AND
ERN ZONES WHERE PWATS WILL BE 1.5 INCHES OR GREATER.
THE THICK LOW CLOUD COVER IN THE MORNING...AND -SHRA SHOULD KEEP
TEMPS FROM RISING MUCH AND WILL CONTINUE TO LEAN TOWARD THE
SLIGHTLY COOLER MET NUMBERS. A BLEND OF THE LATEST 12Z OPERATIONAL
MODELS...SREF...EC AND GEFS QPF SUGGEST RAINFALL AMTS SAT WILL BE
LIGHT...GENERALLY LESS THAN A QUARTER INCH.../AND IN MANY LOCATIONS
JUST 0.10 FROM ONE OR TWO MODERATE SHOWERS/.
MID LEVEL LAPSE RATES DECREASE SATURDAY EVENING AND THE
MEAN...DEEP-LAYER FLOW VEERS AROUND TO MORE OF A SOUTHERLY DIRECTION
WHICH WILL HELP TO THIN OUT SOME OF THE OTHERWISE THICK LAYERED
CLOUDS.
ANY EVENING SHOWERS AND ISOLATED TSRA...WILL BECOME SPOTTY BY
MIDNIGHT.
DEWPOINTS WILL BE ON THE RISE TO COMPENSATE FOR ANY CLEARING...SO
LOW TEMPS WILL BE SEVERAL DEG F HIGHER IN ALL AREAS /AND BACK INTO
THE MUGGY CATEGORY/.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
MED RANGE GUIDANCE CONTINUES TO INDICATE A SPRAWLING WESTERN
ATLANTIC RIDGE RETROGRADING AND STRENGTHENING TO A A NEARLY 600 DM
CENTER OVER THE OHIO VALLEY BY THE MIDDLE OF NEXT WEEK. THIS WILL
SPELL INCREASING HEAT AND HUMIDITY FOR THE EXTENDED PERIOD WITH AT
LEAST SLCT CHC FOR DIURNAL CONVECTION AS DEEP LAYER PW APPROACHES
2.00" ACROSS THE REGION. IMPOSSIBLE TO PREDICT THIS FAR OUT THE CHCS
FOR MCS ACTIVITY...BUT IT APPEARS MAGNITUDE AND LOCATION OF THE
UPPER RIDGE WILL MINIMIZE THE PROPAGATION POTENTIAL OF MCSS
INTO/ACROSS CENTRAL PA EARLY TO MID WEEK.
MEDIUM RANGE GUIDANCE IS ALSO CONSISTENT IN LATE WEEK TREND OF
FLATTENING AND SUPPRESSING THE UPPER RIDGE SOUTHWARD TOWARDS THE
SOUTHEAST ATLANTIC COAST AS BROAD UPPER LEVEL TROF DIGS OVER THE
EASTERN HALF OF CANADA. INCREASING CHC OF MCS ACTIVITY FOLLOWED BY
DRIER AND NOT *AS* WARM CONDITIONS ARE THUS EXPECTED TOWARDS THE END
OF NEXT WEEK.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
WEAK SHOWERS COTINUES TO SPREAD ACROSS THE REGION AS MOIST
SOUTHEASTERLY FLOW MOVES NORTHWESTERLY. THERE IS NO THUNDER IN ANY
OF THIS...AND THAT SHOULD CONTINUE OVERNIGHT. THE SHOWERS CONTINUE
TO SPREAD AND DRY...AS THEY RE ENTERING DRIER AIR MASSES.
HOWEVER...THERE ARE BRIEF HEAVY DOWNPOURS...WHICH WILL REDUCE
VISIBILITIES. EXPECT THIS TO ALLOW FOR ENOUGH MOISTURE...THAT IF
THERE IS ANY CLEARING OF SKIES OVERNIGHT...OR CALMING OF THE WINDS
THAT IT WILL BRING FOG/MIST OVERNIGHT. THE LLVL EASTERLY FLOW
PERSISTS...BUT WEAKENS/GRADUALLY SHIFTS WEST. CIGS WILL LIKELY DIP
TO WIDESPREAD IFR TO LIFR FOR AT LEAST SEVERAL HOURS BETWEEN
08-14Z.
VSBYS SHOULD SLOWLY LIFT TOMORROW MORNING. THE MOIST SOUTHEASTERLY
FLOW SHOULD CONTINUE THROUGH TOMORROW WHICH WILL LIKELY RESULT IN
A MAINLY OVERCAST...HUMID AND SHOWERY SATURDAY WITH MVFR CIGS
LINGERING THROUGH THE AFTERNOON HOURS AND INTO THE EARLY EVENING.
OUTLOOK...
SAT...IFR TO LIFR CIGS EARLY...THEN MVFR. ISOLD TO SCT PM TSRA
IMPACTS...MAINLY ACROSS THE EAST.
SUN...AM LOW CIGS/FOG POSS. ISOLD PM TSRA IMPACTS POSS.
MON-WED...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...DEVOIR
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1048 PM EDT FRI JUL 12 2013
.SYNOPSIS...
A CUT OFF UPPER LOW OVER THE OHIO RIVER VALLEY WILL DRIFT
INTO THE LOWER MISSISSIPPI VALLEY THIS WEEKEND. THE SOUTHERLY FLOW
TO THE EAST OF THIS FEATURE WILL CONTINUE TO BRING MOISTURE AND
SCATTERED SHOWERS TO PENNSYLVANIA FOR THE NEXT FEW DAYS. THE
TEMPERATURES WILL BE CLIMBING NEXT WEEK AS AN UNUSUALLY STRONG
UPPER LEVEL RIDGE FORMS OVERHEAD.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
EARLIER CONVECTION HAS BECOME JUST ANOTHER BAND OF STEADIER-
MODERATE RAIN. AREA OF CONCERN IS NOW EASTERN LANCASTER CO WHERE
THE OCTORARO CREEK VALLEY MAY HAVE PICKED UP MORE THAN AN INCH OF
RAIN IN THE LAST FEW HOURS. FFG IS FAIRLY LOW THERE VS THE REST OF
THE LAND...SO HAVE PUT A FLOOD ADVISORY OUT TO HEIGHTEN AWARENESS.
LACK OF REPORTS OF FLOODING FROM THE COUNTY DISPATCH CENTER AND
VERY LOW PRECIP NUMBERS FROM THE REST OF THE COUNTY LEAD US TO
THINK THAT ANY FLOODING THERE WOULD BE MINOR/NUISANCE TYPE.
OTHERWISE..BUMPED POPS UP FOR THE BALANCE OF THE AREA. THE
CIRCULATION OVER ERN MD AND DE IS HOLDING FAIRLY STILL RIGHT NOW.
NEAR TERM RUC MODEL PORTRAYS A SLOW BREAK UP OF THE SHOWERS AS DRY
AIR APPEARS TO WRAP ALL THE WAY AROUND FROM THE NW/WEST AND IN
FROM THE EAST. REST IS UNCHANGED.
8 PM UPDATE...
LATEST TRENDS IN SENSIBLE WEATHER ARE THE DEVELOPMENT OF
CONVECTION - SANS THUNDER - ALONG THE LEADING EDGE/OUTFLOW OF A
SHIELD OF STRATIFORM PRECIP. THE COOLER AIR IS PROBABLY LIFTING
THE HIGHER CAPE AIR IN THE WARMEST AREAS OF THE CWA...AND POPPING
THE SHOWERS. ACCORDING TO IFLOWS AND OTHER AUTOMATED GAGES AND THE
RADAR PRECIP ESTIMATES...THE PRECIP IS VERY LIGHT COMPARED TO
LOCAL FFG. THIS MEANS FLOODING SHOULD NOT BE A CONCERN THIS
EVENING. POPS AND WX GRIDS IN GREAT SHAPE. ONLY THE MOST MINOR OF
TWEAKS HAVE BEEN MADE WITH THIS UPDATE.
PREVIOUS DISC...
CURRENT 88D MOSAIC CONTINUES TO SHOW A PERSISTENT...SLOW MOVING
AREA OF LIGHT TO MODERATE RAIN ACROSS THE FAR SE COUNTIES OF OUR
CWA.
THE RAIN WILL ADVANCE SLOWLY NWWD ACROSS TWD THE CENTRAL MTNS AND
MIDDLE SUSQ VALLEY LATE THIS AFTERNOON INTO TONIGHT AS SEVERAL
SPOKES OF VORTICITY AND FAVORABLE 825-700 MB FRONTOGENETIC FORCING
PIVOT WWD ACROSS THE FCST AREA...AND THE EASTERLY LLVL FLOW
PEAKS AROUND -4 SIGMA /AT 850 MB/ OVER SOUTHERN PENN THROUGH 00Z
SAT.
THE NWRN EDGE OF THE RAIN SHIELD WILL BE LIGHT FOR MUCH OF THE TIME
THIS AFTERNOON INTO TONIGHT.
RAINFALL OVER THE NEXT 12-16 HOURS WILL AVERAGE LESS THAN A TENTH
OF AN INCH NEAR...AND JUST TO THE SE OF A LINE FROM KIPT TO KUNV
AND KJST WITH VERY LIGHT OR NIL AMTS FURTHER TO THE NW. ACROSS THE
LOWER SUSQ VALLEY AND SCENT MTNS BENEATH THE NOSE OF THE POTENT
EASTERLY LLJ AND STRONGEST/MOST PERSISTENT LOW-MID LEVEL
DEFORMATION ZONES...ADDITIONAL RAINFALL SHOULD FALL INTO THE
0.20-0.30 INCH RANGE WITH HIGHLY LOCALIZED 0.50 INCH AMOUNTS
POSSIBLE WHERE ONE OR TWO SLOW-MOVING LOW TOPPED TSRA DEVELOP NEAR
THE MASON/DIXON LINE.
TEMPS LATE THIS AFTERNOON ACROSS THE CENTRAL AND NW ZONES
WILL BE MAINLY IN THE LOWER TO MID 70S. THE STEADY RAIN ACROSS THE
LOWER SUSQ VALLEY /AND SFC DEWPOINTS IN THE L-M 60S/ HAS CAPPED
TEMPS WELL BELOW NORMAL...AND COOLER THAN MOST OTHER PARTS OF THE
STATE.
ALTHOUGH THE AREAL COVERAGE OF THE LIGHT RAIN WILL INCREASE/EXPAND
TO THE NW TONIGHT...THE INTENSITY SHOULD LIGHTEN UP ACROSS THE SE
ZONES AS THE LLVL EASTERN FLOW WEAKENS AND THE UPPER LOW OVER THE
MID OHIO RIVER VALLEY RETROGRADES 200-300 KM TOWARD THE SW BY SAT
MORNING.
PERSISTENT EASTERLY FLOW OFF OF THE ATLANTIC...COMBINED WITH COOLING
BLYR...WILL LIKELY RESULT IN INCREASING/LOWERING STRATUS ACROSS THE
SOUTHEAST HALF OF PA AND THE LAUREL HIGHLANDS LATE TONIGHT...
WHILE A NON-PRECIPITATING...MID/HIGH CLOUD SHIELD WILL BLANKET
THE NW MTNS.
LOWS TONIGHT WILL VARY FROM 55 TO 60F ACROSS THE NRN AND WRN
MTNS...TO THE MID AND U60S IN THE SE VALLEYS.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
PERSISTENT...MOIST EASTERLY FLOW OVR PA /WITH INCREASING PWATS/ WILL
LIKELY RESULT IN A MAINLY OVERCAST...HUMID AND OCNLY SHOWERY
SATURDAY. MOST OF THE SHOWERS WILL BE CONFINED TO THE CENTRAL AND
ERN ZONES WHERE PWATS WILL BE 1.5 INCHES OR GREATER.
THE THICK LOW CLOUD COVER IN THE MORNING...AND -SHRA SHOULD KEEP
TEMPS FROM RISING MUCH AND WILL CONTINUE TO LEAN TOWARD THE
SLIGHTLY COOLER MET NUMBERS. A BLEND OF THE LATEST 12Z OPERATIONAL
MODELS...SREF...EC AND GEFS QPF SUGGEST RAINFALL AMTS SAT WILL BE
LIGHT...GENERALLY LESS THAN A QUARTER INCH.../AND IN MANY LOCATIONS
JUST 0.10 FROM ONE OR TWO MODERATE SHOWERS/.
MID LEVEL LAPSE RATES DECREASE SATURDAY EVENING AND THE
MEAN...DEEP-LAYER FLOW VEERS AROUND TO MORE OF A SOUTHERLY DIRECTION
WHICH WILL HELP TO THIN OUT SOME OF THE OTHERWISE THICK LAYERED
CLOUDS.
ANY EVENING SHOWERS AND ISOLATED TSRA...WILL BECOME SPOTTY BY
MIDNIGHT.
DEWPOINTS WILL BE ON THE RISE TO COMPENSATE FOR ANY CLEARING...SO
LOW TEMPS WILL BE SEVERAL DEG F HIGHER IN ALL AREAS /AND BACK INTO
THE MUGGY CATEGORY/.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
MED RANGE GUIDANCE CONTINUES TO INDICATE A SPRAWLING WESTERN
ATLANTIC RIDGE RETROGRADING AND STRENGTHENING TO A A NEARLY 600 DM
CENTER OVER THE OHIO VALLEY BY THE MIDDLE OF NEXT WEEK. THIS WILL
SPELL INCREASING HEAT AND HUMIDITY FOR THE EXTENDED PERIOD WITH AT
LEAST SLCT CHC FOR DIURNAL CONVECTION AS DEEP LAYER PW APPROACHES
2.00" ACROSS THE REGION. IMPOSSIBLE TO PREDICT THIS FAR OUT THE CHCS
FOR MCS ACTIVITY...BUT IT APPEARS MAGNITUDE AND LOCATION OF THE
UPPER RIDGE WILL MINIMIZE THE PROPAGATION POTENTIAL OF MCSS
INTO/ACROSS CENTRAL PA EARLY TO MID WEEK.
MEDIUM RANGE GUIDANCE IS ALSO CONSISTENT IN LATE WEEK TREND OF
FLATTENING AND SUPPRESSING THE UPPER RIDGE SOUTHWARD TOWARDS THE
SOUTHEAST ATLANTIC COAST AS BROAD UPPER LEVEL TROF DIGS OVER THE
EASTERN HALF OF CANADA. INCREASING CHC OF MCS ACTIVITY FOLLOWED BY
DRIER AND NOT *AS* WARM CONDITIONS ARE THUS EXPECTED TOWARDS THE END
OF NEXT WEEK.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
A WEAK LINE OF SHOWERS HAS FORMED IN THE SUSQUEHANNA VALLEY. THIS
LINE WILL CONTINUE TO MAKE ITS WAY TO THE NORTHWEST AT 15MPH.
THOUGH AT TIMES THERE IS 50DBZ UP TO 10KFT THERE HAS YET TO BE ANY
LIGHTNING. SO AS CAPE CONTINUES TO WEAKEN AFTER SUNSET...AND THE
LINE IS ENTERING A DRIER AIR MASS...THERE IS A LOW PROBABILITY OF
THUNDER. HOWEVER...THERE ARE BRIEF HEAVY DOWNPOURS...WHICH WILL
REDUCE VISIBILITIES. EXPECT THIS TO ALLOW FOR ENOUGH
MOISTURE...THAT WHEN THE SKIES CLEAR OVERNIGHT...AND WINDS
CALM...WILL BRING FOG/MIST OVERNIGHT. EXPECTING ANY REGION THAT
RECEIVES PRECIPITATION COULD GO IFR BETWEEN 08-14Z.
VFR WILL GRADUALLY DIP TO MVFR VBSYS...WHEN THEY/LL STEADILY DROP
TO LOW END MVFR-IFR TWD MIDNIGHT TONIGHT AS THE LLVL EASTERLY FLOW
PERSISTS...BUT WEAKENS/GRADUALLY SHIFTS WEST. CIGS WILL LIKELY DIP
TO WIDESPREAD IFR TO LIFR FOR AT LEAST SEVERAL HOURS SAT /BETWEEN
07-13Z/.
CONTINUED MOIST EASTERLY FLOW WILL LIKELY RESULT IN A MAINLY
OVERCAST...HUMID AND SHOWERY SATURDAY WITH MVFR CIGS LINGERING INTO
THE AFTERNOON HOURS.
OUTLOOK...
SAT...IFR TO LIFR CIGS EARLY...THEN MVFR. ISOLD TO SCT PM TSRA
IMPACTS...MAINLY ACROSS THE EAST.
SUN...AM LOW CIGS/FOG POSS. ISOLD PM TSRA IMPACTS POSS.
MON-WED...MAINLY VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT
NEAR TERM...DANGELO
SHORT TERM...LAMBERT
LONG TERM...DEVOIR
AVIATION...LAMBERT/CERU
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
754 PM EDT FRI JUL 12 2013
.SYNOPSIS...
ABUNDANT TROPICAL MOISTURE WILL RETURN TO THE AREA THIS
WEEKEND...ALLOWING SHOWERS AND THUNDERSTORMS TO DEVELOP EACH
AFTERNOON. HIGH PRESSURE WILL BUILD IN MONDAY AND PERSIST THROUGH
THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 745 PM EDT...THE HRRR MESOSCALE MODEL HAS BEEN FAIRLY ACCURATE
THIS EVENING IN DEPICTING THE LOCATION OF CONVECTION ALONG THE ERN
SLOPES OF THE HIGHER TERRAIN AND ALONG OUTFLOW BOUNDARIES. IT NOW
HAS ADDITIONAL CONVECTION OVER THE NRN NC MTNS SLIDING SOUTHWARD
ALONG THE BLUE RIDGE AND THE IMMEDIATELY ADJACENT FOOTHILLS THROUGH
MIDNIGHT...AND THIS SOLUTION WILL BE ACCEPTED. COVERAGE AND
INTENSITY ACROSS THE SRN TIER WILL CONTINUE TO WANE WITH THE LOSS OF
HEATING AND GIVEN THAT MOST OF THE AREA HAS BEEN WORKED OVER. WILL
NOT BE ABLE TO COMPLETELY LET GO OF ISOLD TO SCT SHOWERS OVERNIGHT
AS THE BL REMAINS MOIST AND AN EASTERLY COMPONENT TO THE LOW LEVEL
FLOW WILL PERSIST. ANTICIPATE FAIRLY WIDESPREAD LOW CLOUDS AND AND
PATCHY TO AREAS OF FOG TOWARD OVERNIGHT.
THE UPPER LOW WILL RETROGRADE TO THE MS VALLEY SAT...WHILE AT THE
SFC AN INVERTED TROF WILL MOVE INTO THE AREA FROM THE COAST. THIS
WILL KEEP LOW LEVEL SELY UPSLOPE FLOW ACROSS IN PLACE THROUGH THE
DAY WITH CONTINUED COPIOUS LOW LEVEL MOISTURE. THE NAM IS ALONE IN
KEEPING DEEP MOISTURE OUT OF THE AREA WITH THIS SYSTEM...SO HAVE
FOLLOWED THE TRENDS OF THE OTHER GUIDANCE AND INCREASED POP TO
LIKELY OUTSIDE OF THE MTNS BY AFTERNOON. THERE WILL BE ENOUGH
INSTABILITY FOR THUNDERSTORMS TO DEVELOP...BUT SEVERE TSTMS WILL BE
LESS LIKELY AS THE COOL AND DRY MID LEVELS MOVE WEST WITH THE UPPER
LOW. FOR NOW...THE QPF FORECAST DOES NOT SUGGEST WIDESPREAD FLOOD
POTENTIAL DURING THE DAY SAT. THEREFORE...WILL NOT ISSUE A WATCH
ATTM...BUT LATER SHIFTS WILL NEED TO EVALUATE THE POTENTIAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF MIDDAY FRI...ATLANTIC MOISTURE WILL HAVE SPREAD ACROSS THE CWFA
BY THE START OF THE PERIOD IN THE WAKE OF WARM FRONT. MODEST E TO SE
LLVL FLOW WILL BE UNDERWAY AT THAT TIME AND CONTINUE THROUGH THE END
OF THE PERIOD. THIS UPSLOPE FLOW WILL PROVIDE AT LEAST WEAK FORCING
WITH THE MAIN EFFECT TO ENHANCE THE COVERAGE OF ALREADY DIURNALLY
DRIVEN CONVECTION.
THE INITIAL WAVE OF MOISTURE AS SHOWN BY A PLUME OF PWATS NEAR 2
INCHES CROSSES THE CWFA SATURDAY NIGHT INTO SUNDAY MORNING...BUT
DIMINISHES SOMEWHAT AS THE PLUME MOVES INLAND. SATURATED LAYER ON
PROG SOUNDINGS REMAINS SOMEWHAT SHALLOW WITH BEST LOOKING SOUNDINGS
IN THIS REGARD COMING FROM THE MTNS/FOOTHILLS. WEAK NEAR-SFC
INSTABILITY IS SEEN THOUGH...AND INDEED THE NAM PRECIP SHOWN SAT
NIGHT IS ALL CONVECTIVE. CLOUD LAYER FLOW LOOKS STRONG ENOUGH AT THIS
TIME TO LIMIT...BUT NOT TOTALLY ELIMINATE...THE FLASH FLOOD THREAT.
GOING FURTHER INTO THE DAY ON SUNDAY SOME DRYING OCCURS AND PWATS
LOWER CLOSER TO CLIMO. DESPITE THE RELATIVE LACK OF MOISTURE...CAPE
VALUES OF 2000 J OR MORE ARE SHOWN ON THE NAM /1000 OR MORE ON GFS/
SO SOME VIGOROUS CONVECTION COULD DEVELOP. SHEAR WILL CONTINUE TO BE
WEAK BUT STORM MOTIONS FAIRLY SLOW...THUS MORE OF THE SAME CONCERNS
IN THAT REGARD BUT PERHAPS WITH MORE CONCERN FOR SVR WX.
HIGH PRESSURE BUILDS IN SUN NIGHT SOMEWHAT DISRUPTING THE LLVL FLOW
ON THE GFS/NAM DEPICTION OF THE FEATURE...AND CONTINUING TO DRY THE
ATMOSPHERE. A WEAK MIDLEVEL SUBSIDENCE INVERSION DEVELOPS BUT SOME
PROG SOUNDINGS STILL SHOW VERY WEAK INSTABILITY DESPITE A REFLECTION
OF THE SUBSIDENCE. THUS HUNG ON TO VERY LOW BUT MENTIONABLE POPS THRU
THE NIGHT...SLIGHTLY HIGHER WEST WHERE THE BEST LLVL MOISTURE
REMAINS. ON MONDAY WARM MIDLEVELS APPEAR TO CONTINUE TO STIFLE
CONVECTION PARTICULARLY TOWARD THE NORTH NEARER THE CENTER OF THE
HIGH.
WITH THE REGION COMING BACK INTO A MORE TYPICAL PATTERN DOMINATED BY
ATLANTIC HIGH PRESSURE...TEMPERATURES SHOULD MODERATE TO NEAR NORMAL
DURING THE PERIOD...REMAINING SLIGHTLY BELOW NORMAL GIVEN THE MORE
NORTHWARD THAN USUAL POSITION OF THE HIGH.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 130 PM FRIDAY...THE OVERALL PATTERN HAS BECOME DRIER IN THE
LATEST OP MODEL RUNS. THE 12Z GFS IS STILL A MOISTER MODEL WITH THE
UPSLOPE FLOW...WHILE THE ECWMF KEEPS LLVL LAYERED RH THE RATHER LOW.
IN ANY CASE...A DEEP SUB INVERSION WILL BE IN PLACE THROUGH MOST OF
THE PERIOD ASSOCIATED WITH THE ANOMALOUS STACKED HIGH. THUS...SCF
BASED PARCELS WILL HAVE A GOOD AMOUNT OF CIN TO OVERCOME WITH NO
DEFINED KICKER...HOWEVER SOME MODERATE ELCAPE WILL BE AVAILABLE AND
AREAS UNDER DIFFERENTIAL HEATING SHOULD SPAWN ISOL AFTERNOON PULSE
STORMS. THE CLIMO POP IS ADHERED TO ACROSS THE MTNS AS WELL...WITH
NE/LY TO E/LY MECH LIFT PROVIDING THE ADDED FACTOR FOR SCT AFTERNOON
CONVECTION. PWATS WILL REMAIN RELATIVELY LOW...YET INCREASE AS THE
PERIOD PROGRESSES IN A MORE DEFINED AND CONTINUOUS SW/LY LLVL FLOW
ASSOCIATED WITH A DEVELOPING AND NORMALLY PLACED BERMUDA HIGH. MAX
TEMPS WILL RESPOND IN THE DRIER ENVIRONMENT AND A RETURN TO NEAR
NORMAL LEVELS IS EXPECTED THROUGH THE PERIOD. NORMAL MIN TEMPS WILL
ALSO PERSIST AS EVENING CONVECTIVE CLOUDS DISSIPATE AND ALLOW GOOD
RADIATIONAL COOL CONDS.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...THE VICINITY REMAINS LARGELY EXEMPT FROM CONVECTION THIS
EVENING...WITH NEW DEVELOPMENT OCCURRING MAINLY WELL S AND W OF THE
AIRFIELD. WILL CONTINUE THE MENTION OF VCSH FOR A POSSIBLE ROGUE
SHOWER...WITH VFR CIGS THROUGH THE LATE EVENING HOURS. ANTICIPATE A
RETURN TO MVFR AND THEN IFR STRATUS OVERNIGHT WITH CONTINUED HIGH
LEVELS OF BOUNDARY LAYER MOISTURE. THERE SHOULD BE SLOW IMPROVEMENT
TO MVFR THROUGH THE MORNING HOURS ON SATURDAY. NE WINDS CONTINUE
THROUGH THE PERIOD WITH OCCASIONAL GUSTS...AND SHRA/TSRA POSSIBLY
REDEVELOPING DURING THE AFTN HOURS...WHERE A PROB GROUP WILL BE USED.
ELSEWHERE...CONVECTION HAS FINALLY WEAKENED AND DIMINISHED IN
COVERAGE ACROSS THE UPSTATE...BUT ISOLD TSTMS COULD STILL THREATEN
KGMU AND KAND THROUGH THE EVENING HOURS. ADDITIONAL SLOW MOVING
STORMS NEAR THE BLUE RIDGE ARE STAYING AWAY FROM KAVL AND KHKY THUS
FAR...BUT VCTS WILL BE NEEDED AS THESE SLIP SSW ALONG THE ERN SLOPES
THROUGH 04Z. ANTICIPATE COVERAGE DIMINISHING OVERNIGHT...BUT WITH
ROGUE -SHRA POSSIBLE IN ANY UPSLOPE MOISTURE. ANTICIPATE SOLID IFR
CIGS THROUGH DAYBREAK...IMPROVING THROUGH MVFR INTO EARLY
AFTERNOON...WITH SHRA/TSRA REDEVELOPING SAT AFTN. EXPECT MAINLY NE
WINDS AWAY FROM ANY TSTMS.
OUTLOOK...A TROUGH OF LOW PRESSURE WILL MOVE INLAND FROM THE COAST
OVER THE WEEKEND. LOW LEVEL MOISTURE WILL PERSIST...CONTINUING THE
RISK OF SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE
AREA...ALONG WITH MORNING FOG/LOW CLOUDS. HIGH PRESSURE WILL BUILD
OVER THE REGION THROUGH NEXT WEEK...WITH SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS POSSIBLE.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-24Z
KCLT MED 76% MED 79% MED 77% HIGH 87%
KGSP HIGH 91% MED 73% MED 75% HIGH 100%
KAVL HIGH 85% MED 76% HIGH 82% HIGH 90%
KHKY HIGH 90% MED 76% MED 74% HIGH 83%
KGMU HIGH 100% MED 73% MED 75% HIGH 100%
KAND HIGH 100% LOW 49% MED 78% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...HG/RWH
SHORT TERM...WIMBERLEY
LONG TERM...SBK
AVIATION...HG
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
912 PM MDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 859 PM MDT FRI JUL 12 2013
SFC FRONT HAS PROGRESSED SOUTH INTO CENTRAL NE AND IS IN THE
STAGES OF STALLING. MEANWHILE A WEAK IMPULSE IS EJECTING NE FROM
THE NE PANHANDLE...SUPPORTING A POS THETA-E REGIME
THERE...SPREADING NE INTO NORTHERN NE AND EVENTUALLY SCENTRAL SD.
ONGOING LINEAR TS COMPLEX SHOULD CONTINUE NE OVERNIGHT...ARRIVING
IN SCENTRAL SD LATE TONGIHT. THIS IS IN LINE WITH SUGGESTED MODEL
FORECAST PROGS...PARTICULARLY THE HRRR AND RAP. HAVE INCREASED
POPS TO 40 THERE. OTHERWISE...WEAKER IMPULSE NOW TRAVERSING
WESTERN SD AND NE WY WILL PROGRESS NE WITH HIGH BASED MONSOON
ORIGIN MOISTURE SUPPORTING ISOLD SHRA. ALL ELSE ON TRACK.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 253 PM MDT FRI JUL 12 2013
A POSITIVELY TILTED UPPER RIDGE REMAINS STRETCHED ACROSS THE CENTRAL
PLAINS...RESULTING IN SOUTHWEST FLOW ACROSS THE CWA. 20Z SURFACE
ANALYSIS HAS COLD FRONT ALMOST TO KICR AND KVTN AS WINDS HAVE GONE
WESTERLY OVER THE LAST HOUR. LATEST RADAR IMAGERY SHOWS CONVECTION
FIRING IN SOUTHEASTERN WYOMING AND IN THE BIGHORN MOUNTAINS.
FOR THE REST OF THIS AFTERNOON...WILL CONTINUE HEAT ADVISORY FOR
TRIPP COUNTY. THE TEMP IS 95 AT KICR WITH A DEWPOINT OF 67
RESULTING IN A HEAT INDEX RIGHT AROUND 100 DEGREES.
FOR TONIGHT...A WEAK WAVE WILL PUSH THOUGH NORTHEASTERN WYOMING AND
THE BLACK HILLS OVERNIGHT. WITH CONVECTION ALREADY FIRING NEAR THIS
WAVE...EXPECT SHOWERS AND THUNDERSTORMS TO MOVE ACROSS THIS AREA
TONIGHT. FORECAST SOUNDINGS IN THIS AREA ALSO SHOW AN INVERTED V
TYPE PROFILE...THUS WE MAY SEE SOME GUSTY WINDS WITH THESE STORMS.
NOT EXPECTING TOO MUCH DRY LIGHTNING SINCE PW VALUES ARE 135 PERCENT
OF NORMAL.
MONSOONAL FLOW BRINGS AMPLE MOISTURE INTO THE CWA SATURDAY AS
THETA-E RIDGE BUILDS BACK INTO THE AREA. SEVERAL EMBEDDED SHORTWAVES
WILL PASS THROUGH THE AREA...WITH SOME STRONGER ENERGY PROGGED
ACROSS THE REGION SATURDAY NIGHT. SOUTHERN END OF THE COLD FRONT
THAT MOVED THROUGH THIS MORNING WILL WRAP AROUND THE WEST SIDE OF
THE HILLS AND PUSH THROUGH THE AREA AS A TROUGH/WARM FRONT. MLCAPE
OF 1500 TO 2500 J/KG BY AFTERNOON ALONG WITH DIURNAL HEATING AND
DEBSTABILIZATION WILL BE ENOUGH TO FIRE SOME THUNDERSTORMS. THE
0-6KM SHEAR LOOKS TO BE 35-40KTS SUGGESTING ORGANIZED MULTI-CELLULAR
AND SUPER-CELLULAR STORMS. AS THE LOW-LEVEL JST INCREASES DURING THE
EVENING...THESE STORMS WILL CONTINUE OVERNIGHT. WITH PWAT/S FROM
100-150 PERCENT OF NORMAL...LOCALLY HEAVY RAIN MAY OCCUR.
TEMPERATURES WILL BE NEAR GUIDANCE.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 253 PM MDT FRI JUL 12 2013
MONSOONAL FLOW PATTERN WILL REMAIN OVER THE REGION INTO EARLY
NEXT WEEK...BRINGING A GOOD CHANCE FOR THUNDERSTORMS SUNDAY INTO
MONDAY. THERE LOOKS TO BE A THREAT FOR STRONG TO SEVERE STORMS
BOTH DAYS...ESPECIALLY ACROSS NORTHERN AND WESTERN PORTIONS OF THE
CWA...ALONG WITH LOCALLY HEAVY RAIN. A DRIER PATTERN WILL DEVELOP
BEYOND MONDAY...AS THE UPPER RIDGE HOLDS ACROSS THE CENTRAL CONUS.
TEMPERATURES WILL BE NEAR AVERAGE LEVELS FOR SUNDAY AND
MONDAY...WITH ABOVE AVERAGE TEMPERATURES THEN LIKELY THROUGH THE
REST OF THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 528 PM MDT FRI JUL 12 2013
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE EVENING HOURS. THE
EXCEPTION WILL BE ISOLATED TO SCATTERED THUNDERSTORMS ACROSS
NORTHEASTERN WY AND THE BLACK HILLS...WITH THE CHANCES SHIFTING
EAST OF THE BLACK HILLS AFTER MIDNIGHT. LOCAL AND BRIEF MVFR
CONDITIONS ARE POSSIBLE IN THE VICINITY OF ANY STORMS THIS
EVENING...ALONG WITH GUSTY AND ERRATIC WINDS.
&&
.HYDROLOGY...
ISSUED AT 253 PM MDT FRI JUL 12 2013
MONSOONAL FLOW BRINGS AMPLE MOISTURE INTO THE CWA BEGINNING
TONIGHT AND CONTINUING THROUGH THE WEEKEND. WITH PWAT/S FROM
100-150 PERCENT OF NORMAL...LOCALLY HEAVY RAIN MAY OCCUR WITH
THUNDERSTORMS THIS WEEKEND. WILL HOLD OFF ON ANY HYDRO PRODUCTS AT
THIS TIME AS THE TIMING AND AREA IS STILL UNCERTAIN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JC
SHORT TERM...MLS
LONG TERM...15
AVIATION...JC
HYDROLOGY...MLS
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1030 AM EDT THU JUL 11 2013
.DISCUSSION...
SURFACE ANALYSIS SHOWS A COLD FRONT LOCATED ALONG THE OHIO RIVER.
DEWPOINTS AHEAD OF THE FRONT REMAIN IN THE UPPER 60S TO LOWER 70S.
ALOFT...THE 12Z OHX SOUNDING SHOWS VERY DRY AIR ABOVE 650 MB. THE
RUC IS SHOWING SOME CONVECTION DEVELOPING OVER CNTL KY AND MIDDLE
TN THIS AFTERNOON IN A WEAK CONVERGENCE ZONE AHEAD OF THE FRONT. RUC
FORECAST SOUNDINGS SHOW VERY LITTLE CIN THIS AFTERNOON...WITH CAPE
VALUES IN THE 1500-2000 J/KG RANGE. THE DRY AIR ALOFT RESULTS IN
HIGH DCAPE VALUES AND SURFACE-TO-MIDLEVEL THETA-E DIFFERENCES
AROUND 30 DEGREES. SO WHILE THE DRY AIR ALOFT SHOULD REDUCE
COVERAGE OF STORMS THROUGH ENTRAINMENT COMPARED TO YESTERDAY...ANY
STORMS THAT DEVELOP COULD PRODUCE DAMAGING WIND GUSTS.
THE RUC SHOWS GREATEST INSTABILITY AND LOW LEVEL CONVERGENCE ACROSS
SOUTHERN AREAS THIS AFTERNOON...SO WILL ADJUST POPS UPWARD IN THAT
AREA AND DOWNWARD NORTH SLIGHTLY. EXTENSIVE CLOUD COVER THIS
MORNING IS HOLDING TEMPS BACK A BIT...SO WILL LOWER HIGH TEMPS
SLIGHTLY.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
606 PM CDT FRI JUL 12 2013
.DISCUSSION...
SEE 00Z AVIATION DISCUSSION.
&&
.AVIATION...
A WEAK BOUNDARY EXTENDS ACROSS SE TX. THIS FEATURE WILL SINK
SLOWLY SOUTHWARD OVERNIGHT. ISOLATED SHRA/TSRA DEVELOPING BUT THE
ACTIVITY LOOKS TOO ISOLATED TO MENTION IN THE TAF AT THIS TIME.
THINGS SHOULD QUIET DOWN OVERNIGHT WITH VFR CONDS EXPECTED. SOME
CONCERN ABOUT PRECIP ON SAT MORNING AS BOTH THE RAP AND NAM 12
FCST SOUNDINGS SHOW SATURATION AND INSTABILITY. PREV SET OF TAFS
DID NOT MENTION PRECIP SO WILL AWAIT THE 00Z MODEL RUNS BEFORE
MAKING A DECISION ON WHETHER TO ADD VCSH FOR AREA TAFS. 43
&&
.PREV DISCUSSION... /ISSUED 342 PM CDT FRI JUL 12 2013/
DISCUSSION...
HAVE A FEW CELLS INTERMITTENTLY POPPING UP ALONG THE SEABREEZE/BAYBREEZE
WHICH SHOULD DISSIPATE THIS EVENING. ALSO STARTING TO SEE A FEW
POP UP IN LA AND EXTREME E TX AHEAD OF A WEAK BACKDOOR FRONTAL
BOUNDARY. THIS ACTIVITY HAS MORE MID/UPPER DRY AIR TO DEAL WITH
BUT STILL WORTH KEEPING AN EYE ON IN THE NEXT SEVERAL HOURS.
BACKDOOR FRONT WILL ADVECT SOME DRIER AIR INTO THE REGION...PRIMARILY
INLAND COUNTIES ALONG/N OF I-10. SO WE`LL HAVE SOME OF THE BELOVED
"DRY" HEAT ON SAT. SEABREEZE MIGHT MAKE IT TO ABOUT THE I-10
CORRIDOR LATE AND THAT SHOULD BE ABOUT IT.
12Z NAM12/GFS/ECMWF MODELS ARE ALL SHOWING SOME ENERGY DIVING DOWN
INTO TX IN THE NRLY FLOW ALOFT ON SUNDAY (ON THE WEST SIDE OF
RETROGRADING LOW). ALL DEPICT THE POSSIBILITY OF SOME OF THE
ASSOCIATED STORMS MAKING IT INTO N/NW PARTS OF THE CWA LATE SUN
AFTN OR EVENING SO BUMPED POPS UP DURING THAT TIME PERIOD. MAY
NEED TO GO HIGHER W/ FUTURE MODEL CONSISTENCY.
NO REAL CHANGES TO THE FCST OR REASONING NEXT WEEK. GULF BECOMES
ESSENTIALLY WIDE OPEN OVER SE TX WITH SFC & UPPER LEVEL RIDGES
SITUATED OFF TO THE E/NE. PW`S FCST TO INCREASE TO 1.8-2.2" DURING
THE TIME PERIOD WHICH WOULD FAVOR SCT DIURNAL CONVECTION EACH
DAY...SOME DAYS MORE THAN OTHERS DEPENDING ON AVAIL MOISTURE ETC.
GFS/ECMWF DEPICTION OF DAILY HIGH AREAL COVERAGE LOOKS RATHER SUSPECT
GIVEN THE OVERALL PATTERN. FOR EXAMPLE RARELY DOES ONE SEE A LOT
OF PRECIP IN THE NEARSHORE GULF WATERS & BEACHES DURING THE AFTN
HOURS WITH SUCH A PATTERN. WOULD BE MORE TYPICAL IN THE WATERS AT
NIGHT & MORNING THEN INLAND DURING THE DAY WITH HEATING. KEPT 30%
POPS GOING WITH THE ABOVE REASONING IN MIND - BUT HAVE LITTLE
DOUBT SOME DAYS WILL NEED TO INCREASED AS CONFIDENCE/TIMING IMPROVES.
THIS DOES CURRENTLY APPEAR TO BE THE LONGEST STRETCH OF FAVORABLE
RAIN CHANCES WE`VE SEEN SO FAR THIS SUMMER. 47
MARINE...
A WEAK FRONTAL BOUNDARY WILL PERSIST AND KEEP RAIN CHANCES IN PLACE
OFF AND ON FOR THE NEXT COUPLE OF DAYS. A GENERAL ONSHORE FLOW
PATTERN SHOULD PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT
WEEK. 40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 101 75 99 74 95 / 10 20 10 10 30
HOUSTON (IAH) 98 77 97 75 94 / 10 20 10 10 20
GALVESTON (GLS) 92 81 92 81 91 / 30 20 20 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...33
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
940 PM EDT FRI JUL 12 2013
.SYNOPSIS...
UPPER LOW PRESSURE OVER WEST VIRGINIA WILL DRIFT WEST
TONIGHT...THEN THEN SLOWLY DRIFT WEST INTO KENTUCKY AND TENNESSEE
DURING THE WEEKEND. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD
WESTWARD FROM THE WESTERN ATLANTIC INTO THE MID- ATLANTIC REGION
BY EARLY NEXT WEEK. SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WEEKEND...BUT SHOULD DIMINISH SOME NEXT WEEK AND
BECOME MORE ISOLATED AND TYPICAL OF SUMMER EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 940 PM EDT FRIDAY...
ONLY MINOR CHANGES MADE TO THE FORECAST LATE THIS EVENING. THE
BIGGEST ADJUSTMENT WAS TO BETTER DEPICT IN THE GRIDS THE ALIGNMENT
OF THE CURRENT BEST AREA OF SHOWERS AND STORMS ACROSS THE
SOUTHWEST PART OF THE FORECAST AREA...AND THEN TO SHOW THE GRADUAL
DECLINE AND COVERAGE AS MIDNIGHT APPORACHES. PAST MIDNIGHT...WE
STILL ARE OFFERING A FORECAST THAT SHOWS SHOWERS INCREASING IN
COVERAGE ALONG AND EAST OF THE CREST OF THE BLUE RIDGE AS LOW
LEVEL WINDS TURN MORE E-SE AND A SHORTWAVE TROUGH HEADS NORTH
THROUGH CENTRAL VA. HAVE ALSO TWEAKED HOURLY TEMPERATURES AND DEW
POINTS BASE UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE VERY EARLY MORNING HOURS OF SATURDAY.
AS OF 655 PM EDT FRIDAY...
DEVELOPMENT OF A GENEROUS COVERAGE OF SHOWERS AND STORMS ACROSS
CENTRAL AND EASTERN PARTS OF THE REGION IS NOT PANNING OUT
CURRENTLY. HAVE GREATLY REDUCED THE CHANCE OF PRECIPITATION
THROUGH THE EVENING HOURS. HOWEVER...ANY ISOLATED SHOWER OR
STORMS THAT DOES FORM WILL HAVE THE POTENTIAL OF PRODUCING LOCALLY
HEAVY RAIN OVER AN ALREADY SATURATED GROUND. MODEL GUIDANCE STILL
IS OFFERING A SOLTUION THAT BRINGS LOW LEVEL WINDS MORE AROUND TO
THE SOUTHEAST OR EAST BY LATE TONIGHT...ALONG WITH A WAVE OF
MOISTURE THAT PRODUCES PRECIPITATION ACROSS MOSTLY EASTERN...BUT
ALSO PARTS OF THE CENTRAL AND WESTERN SECTIONS OF THE REGION. ANY
HEAVY CELL WITHIN THIS EXPECTED PRECIPITATION WILL ALSO HAVE THE
POTENTIAL FOR VERY HEAVY RAIN AND FLASH FLOODING. WILL ALLOW THE
FLASH FLOOD WATCH TO CONTINUE...BUT ITS TIMING EMPHASIS WILL NOW
BE TOWARD THE TAIL END OF THE EVENT...WITH FLASH FLOODING DURING
THE FRONT END CONFINED TO VERY ISOLATED ACTIVITY THROUGH THE
EVENING.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
CONDITIONS BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE EVNEING HOURS.
AS OF 320 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
WILL CONTINUE INTO TONIGHT. WITH PWAT STILL RELATIVELY HIGH...LOW
FFG(LESS THAN 1.0 INCH/HR IN SOME COUNTY) AND VERY WET
GROUND (RECENT RAINS)...THE POTENTIAL FOR FLASH FLOODING
CONTINUES THIS AFTERNOON INTO TONIGHT. HRRR AND RAP
FOCUS CONVECTION ON THE SOUTHERN BLUE RIDGE AND EASTWARD THIS
EVENING...THEN TAPER OFF OVERNIGHT INTO SATURDAY MORNING. GFS AND
NAM SEEM TO KEEP THE AXIS OF HEAVIER PRECIPITATION FURTHER EAST.
KEEP THE HIGHEST POPS THIS EVENING INTO TONIGHT...THEN DECREASE
POPS OVERNIGHT. EXPECTED SHOWERS TO LINGER INTO THE OVERNIGHT
HOURS WITH AREAS OF FOG. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE UPPER 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE SOUTHEAST.
ON SATURDAY...THE CLOSED MID/UPR LOW WILL BE OVER KY AND IS
PROGGED TO DRIFT W REACHING THE MISS RIVER VALLEY BY 00Z SUNDAY.
PLENTY OF MOISTURE AND WEAK MID LEVEL VORTICITY CENTERS MOVE
ACROSS THE REGION DURING THE AFTERNOON AND EVENING CREATING
SCATTERED SHOWERS AND THUNDERSTORMS. ADDITIONAL FLASH FLOOD
WATCHES MAY BE ISSUED THIS WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
BY SUNDAY MORNING...MOST OF THE MEDIUM RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE UPPER LEVEL LOW WILL BE POSITIONED SOMEWHERE IN
THE MISSISSIPPI VALLEY WITH AN UPPER LEVEL HIGH BUILDING IN THE MID-
ATLANTIC REGION. WHILE THE DEEPEST MOISTURE WILL BE PULLED WEST OF
OUR FORECAST AREA...A WEAK SOUTHEAST LOW LEVEL FLOW AND WEAK WAVES
MOVING UNDER THE SOUTHERN PERIPHERY OF THE UPPER LEVEL HIGH WILL
BRING SCATTERED SHOWERS AND STORMS. PLACED THE HIGHEST POPS ALONG
THOSE FAVORED UPSLOPE EAST FACING SLOPES ALONG THE SOUTHERN BLUE
RIDGE.
DRIER AIR FINALLY ARRIVES SUNDAY NIGHT AND MONDAY AS PWATS FALL TO
UNDER 1.5 INCHES UNDER THE EXPANDING UPPER LEVEL RIDGE. WHILE
ISOLATED CONVECTION IS POSSIBLE IN THE MOUNTAINS...MOST AREAS WILL
BE DRY. WITH THE BUILDING RIDGE AND WARMING 850MB TEMPS...LEANED
TOWARD THE WARMER GFS GUIDANCE FOR FORECAST HIGHS.
CONTINUED VERY WARM TUESDAY...WITH SLIGHTLY INCREASED COVERAGE IN
SHOWERS AND STORMS IN THE MOUNTAINS AS PWATS INCREASE AND THE HINT
OF A WEAK UPPER LEVEL WAVE DRIFTS SOUTH UNDER THE UPPER RIDGE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
THE LONG RANGE DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD
AGREEMENT THAT AN LARGE UPPER RIDGE...AS STRONG AS 598DM...WILL OVER
OUR FORECAST AREA THROUGH THE LONG TERM PERIOD...WITH THE RIDGE
DAMPENING BY LATE IN THE WEEK AS A BROAD TROF FORMS IN EASTERN
CANADA.
TEMPERATURES WILL BE ABOVE NORMAL WITH GEFS ENSEMBLES SHOWING 850MB
TEMPS 1-2 STANDARD DEVIATIONS ABV AVERAGE AND 500MB HEIGHTS ALSO 1-2
SD ABOVE AVERAGE. INCREASED HIGHS A DEGREE OR TWO DURING THE LONG
TERM PERIOD. WHILE THE UPPER RIDGE WEAKENS LATE THE WEEK...A MORE
WESTERLY (DOWNSLOPING) COMPONENT TO THE WIND WILL KEEP TEMPS ABV
NORMAL.
EXPECT PRECIP TO BE DRIVEN BY DAYTIME HEATING...AND MAINLY CONFINED
TO THE MOUNTAINS. PWATS INCREASE FROM 1.5 TO GREATER THAN 2.0 INCHES
BY LATE IN THE WEEK...SO WHILE THE COVERAGE WILL BE WIDELY SCATTERED
SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 755 PM EDT FRIDAY...
SHOWER AND THUNDERSTORM ACTIVITY IS CONFINED PRIMARILY ALONG AND
WEST OF A LINE BETWEEN ROUGHLY KTNB-KBKW. MOST THE THE REGION IS
EXPERICING VFR CONDITIONS WITH POCKETS OF MVFR CIGS.
OVERNIGHT...CEILINGS WILL SLOWLY TREND TO IFR CONDITIONS AT MOST
LOCATIONS...ALONG WITH MVFR VISIBILITIES. MOST OF THE
PRECIPITATION WILL REMAIN ACROSS THE FAR WESTERN PART OF THE
FORECAST AREA...BUT A VERY ISOLATED SHOWER OR STORM CANNOT BE
RULED OUT ELSEWHERE. AFTER ABOUT 06Z/2AM SATURDAY...LOW LEVEL
WINDS WILL BECOME E-SE ACROSS THE EASTERN PART OF THE AREA...AND A
WAVE MOVING NORTH ON THE EAST SIDE OF THE UPPER LOW MAY HELP
PROMPT DEVELOPMENT OF A GREAT CONCENTRATION OF SHOWERS ALONG AND
EAST OF A KLYH-KDAN LINE WITH ISOLATED COVERAGE WEST OF THIS LINE.
CONDITIONS WILL SLOWLY IMPROVE TO VFR CONDITIONS BY 14Z/10AM
WEDNESDAY ACROSS MOST OF THE REGION WITH SHOWERS AND STORMS AGAIN
BECOMING MORE NUMEROUS BY MID-DAY.
AS OF 130 PM EDT FRIDAY...
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
AS OF 705 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES THIS EVENING AND OVERNIGHT...BUT OTHER
THAN THE NORTHERN MOUNTAINS OF NORTH CAROLINA...THE FOCUS FOR THE
FLASH FLOOD CONCERN HAS SHIFTED TO LATE TONIGHT WHEN PRECIPITATION
IS EXPECTED TO ARRIVE ACROSS EASTERN PARTS OF THE AREA. THIS
EVENING...ISOLATED SHOWERS AND STORMS ACROSS CENTRAL AND EASTERN
PARTS OF THE WATCH AREA MAY PRODUCE ENOUGH HEAVY RAIN TO PROMPT
FLASH FLOODING...ESPECIALLY IF THE CELLS ARE SLOW MOVING.
AS OF 120 PM EDT FRIDAY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
RIVER FLOOD WARNING IS CANCELLED FOR THE DAN RIVER NEAR DANVILLE.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN
VIRGINIA...DAN RIVER NEAR PACES...MINOR FLOODING IS FORECAST.
MINOR FLOODING IS ALSO OCCURING ALONG THE ROANOKE RIVER AT
RANDOLPH...DAN RIVER AT SOUTH BOSTON. REFER TO LATEST FLOOD
WARNINGS...RIVER FLOOD WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL 8 AM EDT SATURDAY FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL 8 AM EDT SATURDAY FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...DS/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...DS/KK/MBS/RAB
HYDROLOGY...DS/KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
804 PM EDT FRI JUL 12 2013
.SYNOPSIS...
UPPER LOW PRESSURE OVER WEST VIRGINIA WILL DRIFT WEST
TONIGHT...THEN THEN SLOWLY DRIFT WEST INTO KENTUCKY AND TENNESSEE
DURING THE WEEKEND. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD
WESTWARD FROM THE WESTERN ATLANTIC INTO THE MID- ATLANTIC REGION
BY EARLY NEXT WEEK. SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WEEKEND...BUT SHOULD DIMINISH SOME NEXT WEEK AND
BECOME MORE ISOLATED AND TYPICAL OF SUMMER EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 655 PM EDT FRIDAY...
DEVELOPMENT OF A GENEROUS COVERAGE OF SHOWERS AND STORMS ACROSS
CENTRAL AND EASTERN PARTS OF THE REGION IS NOT PANNING OUT
CURRENTLY. HAVE GREATLY REDUCED THE CHANCE OF PRECIPITATION
THROUGH THE EVENING HOURS. HOWEVER...ANY ISOLATED SHOWER OR
STORMS THAT DOES FORM WILL HAVE THE POTENTIAL OF PRODUCING LOCALLY
HEAVY RAIN OVER AN ALREADY SATURATED GROUND. MODEL GUIDANCE STILL
IS OFFERING A SOLTUION THAT BRINGS LOW LEVEL WINDS MORE AROUND TO
THE SOUTHEAST OR EAST BY LATE TONIGHT...ALONG WITH A WAVE OF
MOISTURE THAT PRODUCES PRECIPITATION ACROSS MOSTLY EASTERN...BUT
ALSO PARTS OF THE CENTRAL AND WESTERN SECTIONS OF THE REGION. ANY
HEAVY CELL WITHIN THIS EXPECTED PRECIPITATION WILL ALSO HAVE THE
POTENTIAL FOR VERY HEAVY RAIN AND FLASH FLOODING. WILL ALLOW THE
FLASH FLOOD WATCH TO CONTINUE...BUT ITS TIMING EMPHASIS WILL NOW
BE TOWARD THE TAIL END OF THE EVENT...WITH FLASH FLOODING DURING
THE FRONT END CONFINED TO VERY ISOLATED ACTIVITY THROUGH THE
EVENING.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
CONDITIONS BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE EVNEING HOURS.
AS OF 320 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
WILL CONTINUE INTO TONIGHT. WITH PWAT STILL RELATIVELY HIGH...LOW
FFG(LESS THAN 1.0 INCH/HR IN SOME COUNTY) AND VERY WET
GROUND (RECENT RAINS)...THE POTENTIAL FOR FLASH FLOODING
CONTINUES THIS AFTERNOON INTO TONIGHT. HRRR AND RAP
FOCUS CONVECTION ON THE SOUTHERN BLUE RIDGE AND EASTWARD THIS
EVENING...THEN TAPER OFF OVERNIGHT INTO SATURDAY MORNING. GFS AND
NAM SEEM TO KEEP THE AXIS OF HEAVIER PRECIPITATION FURTHER EAST.
KEEP THE HIGHEST POPS THIS EVENING INTO TONIGHT...THEN DECREASE
POPS OVERNIGHT. EXPECTED SHOWERS TO LINGER INTO THE OVERNIGHT
HOURS WITH AREAS OF FOG. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE UPPER 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE SOUTHEAST.
ON SATURDAY...THE CLOSED MID/UPR LOW WILL BE OVER KY AND IS
PROGGED TO DRIFT W REACHING THE MISS RIVER VALLEY BY 00Z SUNDAY.
PLENTY OF MOISTURE AND WEAK MID LEVEL VORTICITY CENTERS MOVE
ACROSS THE REGION DURING THE AFTERNOON AND EVENING CREATING
SCATTERED SHOWERS AND THUNDERSTORMS. ADDITIONAL FLASH FLOOD
WATCHES MAY BE ISSUED THIS WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
BY SUNDAY MORNING...MOST OF THE MEDIUM RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE UPPER LEVEL LOW WILL BE POSITIONED SOMEWHERE IN
THE MISSISSIPPI VALLEY WITH AN UPPER LEVEL HIGH BUILDING IN THE MID-
ATLANTIC REGION. WHILE THE DEEPEST MOISTURE WILL BE PULLED WEST OF
OUR FORECAST AREA...A WEAK SOUTHEAST LOW LEVEL FLOW AND WEAK WAVES
MOVING UNDER THE SOUTHERN PERIPHERY OF THE UPPER LEVEL HIGH WILL
BRING SCATTERED SHOWERS AND STORMS. PLACED THE HIGHEST POPS ALONG
THOSE FAVORED UPSLOPE EAST FACING SLOPES ALONG THE SOUTHERN BLUE
RIDGE.
DRIER AIR FINALLY ARRIVES SUNDAY NIGHT AND MONDAY AS PWATS FALL TO
UNDER 1.5 INCHES UNDER THE EXPANDING UPPER LEVEL RIDGE. WHILE
ISOLATED CONVECTION IS POSSIBLE IN THE MOUNTAINS...MOST AREAS WILL
BE DRY. WITH THE BUILDING RIDGE AND WARMING 850MB TEMPS...LEANED
TOWARD THE WARMER GFS GUIDANCE FOR FORECAST HIGHS.
CONTINUED VERY WARM TUESDAY...WITH SLIGHTLY INCREASED COVERAGE IN
SHOWERS AND STORMS IN THE MOUNTAINS AS PWATS INCREASE AND THE HINT
OF A WEAK UPPER LEVEL WAVE DRIFTS SOUTH UNDER THE UPPER RIDGE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
THE LONG RANGE DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD
AGREEMENT THAT AN LARGE UPPER RIDGE...AS STRONG AS 598DM...WILL OVER
OUR FORECAST AREA THROUGH THE LONG TERM PERIOD...WITH THE RIDGE
DAMPENING BY LATE IN THE WEEK AS A BROAD TROF FORMS IN EASTERN
CANADA.
TEMPERATURES WILL BE ABOVE NORMAL WITH GEFS ENSEMBLES SHOWING 850MB
TEMPS 1-2 STANDARD DEVIATIONS ABV AVERAGE AND 500MB HEIGHTS ALSO 1-2
SD ABOVE AVERAGE. INCREASED HIGHS A DEGREE OR TWO DURING THE LONG
TERM PERIOD. WHILE THE UPPER RIDGE WEAKENS LATE THE WEEK...A MORE
WESTERLY (DOWNSLOPING) COMPONENT TO THE WIND WILL KEEP TEMPS ABV
NORMAL.
EXPECT PRECIP TO BE DRIVEN BY DAYTIME HEATING...AND MAINLY CONFINED
TO THE MOUNTAINS. PWATS INCREASE FROM 1.5 TO GREATER THAN 2.0 INCHES
BY LATE IN THE WEEK...SO WHILE THE COVERAGE WILL BE WIDELY SCATTERED
SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 755 PM EDT FRIDAY...
SHOWER AND THUNDERSTORM ACTIVITY IS CONFINED PRIMARILY ALONG AND
WEST OF A LINE BETWEEN ROUGHLY KTNB-KBKW. MOST THE THE REGION IS
EXPERICING VFR CONDITIONS WITH POCKETS OF MVFR CIGS.
OVERNIGHT...CEILINGS WILL SLOWLY TREND TO IFR CONDITIONS AT MOST
LOCATIONS...ALONG WITH MVFR VISIBILITIES. MOST OF THE
PRECIPITATION WILL REMAIN ACROSS THE FAR WESTERN PART OF THE
FORECAST AREA...BUT A VERY ISOLATED SHOWER OR STORM CANNOT BE
RULED OUT ELSEWHERE. AFTER ABOUT 06Z/2AM SATURDAY...LOW LEVEL
WINDS WILL BECOME E-SE ACROSS THE EASTERN PART OF THE AREA...AND A
WAVE MOVING NORTH ON THE EAST SIDE OF THE UPPER LOW MAY HELP
PROMPT DEVELOPMENT OF A GREAT CONCENTRATION OF SHOWERS ALONG AND
EAST OF A KLYH-KDAN LINE WITH ISOLATED COVERAGE WEST OF THIS LINE.
CONDITIONS WILL SLOWLY IMPROVE TO VFR CONDITIONS BY 14Z/10AM
WEDNESDAY ACROSS MOST OF THE REGION WITH SHOWERS AND STORMS AGAIN
BECOMING MORE NUMEROUS BY MID-DAY.
AS OF 130 PM EDT FRIDAY...
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
AS OF 705 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES THIS EVENING AND OVERNIGHT...BUT OTHER
THAN THE NORTHERN MOUNTAINS OF NORTH CAROLINA...THE FOCUS FOR THE
FLASH FLOOD CONCERN HAS SHIFTED TO LATE TONIGHT WHEN PRECIPITATION
IS EXPECTED TO ARRIVE ACROSS EASTERN PARTS OF THE AREA. THIS
EVENING...ISOLATED SHOWERS AND STORMS ACROSS CENTRAL AND EASTERN
PARTS OF THE WATCH AREA MAY PRODUCE ENOUGH HEAVY RAIN TO PROMPT
FLASH FLOODING...ESPECIALLY IF THE CELLS ARE SLOW MOVING.
AS OF 120 PM EDT FRIDAY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
RIVER FLOOD WARNING IS CANCELLED FOR THE DAN RIVER NEAR DANVILLE.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN
VIRGINIA...DAN RIVER NEAR PACES...MINOR FLOODING IS FORECAST.
MINOR FLOODING IS ALSO OCCURING ALONG THE ROANOKE RIVER AT
RANDOLPH...DAN RIVER AT SOUTH BOSTON. REFER TO LATEST FLOOD
WARNINGS...RIVER FLOOD WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...DS/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...DS/KK/MBS/RAB
HYDROLOGY...DS/KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
708 PM EDT FRI JUL 12 2013
.SYNOPSIS...
UPPER LOW PRESSURE OVER WEST VIRGINIA WILL DRIFT WEST
TONIGHT...THEN THEN SLOWLY DRIFT WEST INTO KENTUCKY AND TENNESSEE
DURING THE WEEKEND. MEANWHILE...HIGH PRESSURE ALOFT WILL BUILD
WESTWARD FROM THE WESTERN ATLANTIC INTO THE MID- ATLANTIC REGION
BY EARLY NEXT WEEK. SHOWERS AND THUNDERSTORMS WILL CONTINUE
THROUGH THE WEEKEND...BUT SHOULD DIMINISH SOME NEXT WEEK AND
BECOME MORE ISOLATED AND TYPICAL OF SUMMER EARLY NEXT WEEK AS THE
UPPER RIDGE BUILDS OVER THE AREA.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 655 PM EDT FRIDAY...
DEVELOPMENT OF A GENEROUS COVERAGE OF SHOWERS AND STORMS ACROSS
CENTRAL AND EASTERN PARTS OF THE REGION IS NOT PANNING OUT
CURRENTLY. HAVE GREATLY REDUCED THE CHANCE OF PRECIPITATION
THROUGH THE EVENING HOURS. HOWEVER...ANY ISOLATED SHOWER OR
STORMS THAT DOES FORM WILL HAVE THE POTENTIAL OF PRODUCING LOCALLY
HEAVY RAIN OVER AN ALREADY SATURATED GROUND. MODEL GUIDANCE STILL
IS OFFERING A SOLTUION THAT BRINGS LOW LEVEL WINDS MORE AROUND TO
THE SOUTHEAST OR EAST BY LATE TONIGHT...ALONG WITH A WAVE OF
MOISTURE THAT PRODUCES PRECIPITATION ACROSS MOSTLY EASTERN...BUT
ALSO PARTS OF THE CENTRAL AND WESTERN SECTIONS OF THE REGION. ANY
HEAVY CELL WITHIN THIS EXPECTED PRECIPITATION WILL ALSO HAVE THE
POTENTIAL FOR VERY HEAVY RAIN AND FLASH FLOODING. WILL ALLOW THE
FLASH FLOOD WATCH TO CONTINUE...BUT ITS TIMING EMPHASIS WILL NOW
BE TOWARD THE TAIL END OF THE EVENT...WITH FLASH FLOODING DURING
THE FRONT END CONFINED TO VERY ISOLATED ACTIVITY THROUGH THE
EVENING.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
CONDITIONS BASED UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS
THROUGH THE EVNEING HOURS.
AS OF 320 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES UNTIL 8 AM SATURDAY MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
WILL CONTINUE INTO TONIGHT. WITH PWAT STILL RELATIVELY HIGH...LOW
FFG(LESS THAN 1.0 INCH/HR IN SOME COUNTY) AND VERY WET
GROUND (RECENT RAINS)...THE POTENTIAL FOR FLASH FLOODING
CONTINUES THIS AFTERNOON INTO TONIGHT. HRRR AND RAP
FOCUS CONVECTION ON THE SOUTHERN BLUE RIDGE AND EASTWARD THIS
EVENING...THEN TAPER OFF OVERNIGHT INTO SATURDAY MORNING. GFS AND
NAM SEEM TO KEEP THE AXIS OF HEAVIER PRECIPITATION FURTHER EAST.
KEEP THE HIGHEST POPS THIS EVENING INTO TONIGHT...THEN DECREASE
POPS OVERNIGHT. EXPECTED SHOWERS TO LINGER INTO THE OVERNIGHT
HOURS WITH AREAS OF FOG. LOW TEMPERATURES TONIGHT WILL RANGE FROM
THE UPPER 50S IN THE MOUNTAINS TO THE UPPER 60S IN THE SOUTHEAST.
ON SATURDAY...THE CLOSED MID/UPR LOW WILL BE OVER KY AND IS
PROGGED TO DRIFT W REACHING THE MISS RIVER VALLEY BY 00Z SUNDAY.
PLENTY OF MOISTURE AND WEAK MID LEVEL VORTICITY CENTERS MOVE
ACROSS THE REGION DURING THE AFTERNOON AND EVENING CREATING
SCATTERED SHOWERS AND THUNDERSTORMS. ADDITIONAL FLASH FLOOD
WATCHES MAY BE ISSUED THIS WEEKEND.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 300 PM EDT FRIDAY...
BY SUNDAY MORNING...MOST OF THE MEDIUM RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE UPPER LEVEL LOW WILL BE POSITIONED SOMEWHERE IN
THE MISSISSIPPI VALLEY WITH AN UPPER LEVEL HIGH BUILDING IN THE MID-
ATLANTIC REGION. WHILE THE DEEPEST MOISTURE WILL BE PULLED WEST OF
OUR FORECAST AREA...A WEAK SOUTHEAST LOW LEVEL FLOW AND WEAK WAVES
MOVING UNDER THE SOUTHERN PERIPHERY OF THE UPPER LEVEL HIGH WILL
BRING SCATTERED SHOWERS AND STORMS. PLACED THE HIGHEST POPS ALONG
THOSE FAVORED UPSLOPE EAST FACING SLOPES ALONG THE SOUTHERN BLUE
RIDGE.
DRIER AIR FINALLY ARRIVES SUNDAY NIGHT AND MONDAY AS PWATS FALL TO
UNDER 1.5 INCHES UNDER THE EXPANDING UPPER LEVEL RIDGE. WHILE
ISOLATED CONVECTION IS POSSIBLE IN THE MOUNTAINS...MOST AREAS WILL
BE DRY. WITH THE BUILDING RIDGE AND WARMING 850MB TEMPS...LEANED
TOWARD THE WARMER GFS GUIDANCE FOR FORECAST HIGHS.
CONTINUED VERY WARM TUESDAY...WITH SLIGHTLY INCREASED COVERAGE IN
SHOWERS AND STORMS IN THE MOUNTAINS AS PWATS INCREASE AND THE HINT
OF A WEAK UPPER LEVEL WAVE DRIFTS SOUTH UNDER THE UPPER RIDGE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 PM EDT FRIDAY...
THE LONG RANGE DETERMINISTIC AND ENSEMBLE MODELS ARE IN GOOD
AGREEMENT THAT AN LARGE UPPER RIDGE...AS STRONG AS 598DM...WILL OVER
OUR FORECAST AREA THROUGH THE LONG TERM PERIOD...WITH THE RIDGE
DAMPENING BY LATE IN THE WEEK AS A BROAD TROF FORMS IN EASTERN
CANADA.
TEMPERATURES WILL BE ABOVE NORMAL WITH GEFS ENSEMBLES SHOWING 850MB
TEMPS 1-2 STANDARD DEVIATIONS ABV AVERAGE AND 500MB HEIGHTS ALSO 1-2
SD ABOVE AVERAGE. INCREASED HIGHS A DEGREE OR TWO DURING THE LONG
TERM PERIOD. WHILE THE UPPER RIDGE WEAKENS LATE THE WEEK...A MORE
WESTERLY (DOWNSLOPING) COMPONENT TO THE WIND WILL KEEP TEMPS ABV
NORMAL.
EXPECT PRECIP TO BE DRIVEN BY DAYTIME HEATING...AND MAINLY CONFINED
TO THE MOUNTAINS. PWATS INCREASE FROM 1.5 TO GREATER THAN 2.0 INCHES
BY LATE IN THE WEEK...SO WHILE THE COVERAGE WILL BE WIDELY SCATTERED
SOME LOCALLY HEAVY DOWNPOURS WILL BE POSSIBLE.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 130 PM EDT FRIDAY...
CLOSED UPPER LOW OVER THE AREA SCHEDULED TO RETROGRADE TO MIDWEST
OVER THE NEXT FEW DAYS. SCT-BKN MVFR CLOUDS WITH POCKETS OF IFR
IN CONVECTION AND AREAS OF FOG.
SCATTERED SHOWERS AND THUNDERSTORMS...SOME WITH HEAVY RAINS
EXPECTED THIS AFTERNOON INTO TONIGHT. BELIEVE THE TRENDS WILL BE
SIMILAR TO PREVIOUS DAYS IN A WEAKLY FORCED ENVIRONMENT. KLWB
HAS THE BEST CHANCE OF A THUNDERSTORM THIS AFTERNOON.
AS UPPER LOW BEGINS ITS WWD TREK...A SHORTWAVE WILL DRIFT OVER
THE AREA TONIGHT WITH FLOW BECOMING SELY. THIS SHOULD KEEP
SHOWERS IN THE AREA FOR THE OVERNIGHT. MODELS ALSO SHOW MOISTURE
SUCKING BACK WWD AS THE LOW MOVES...AND THIS SHOULD LEAD TO
IFR/LIFR CONDITIONS DEVELOPING OVERNIGHT.
.AVIATION EXTENDED...
DEEP EASTERLY FLOW CONTINUES INTO SATURDAY WITH WIDESPREAD SHOWERS
EXPECTED. SUNDAY THROUGH TUESDAY EXPECT A DAILY AFTERNOON AND
EVENING THREAT OF SHOWERS AND THUNDERSTORMS WITH EARLY MORNING IFR
BR/FG...BUT OVERALL IMPROVED CONDITIONS WITH MUCH MORE VFR THAN
CURRENT.
&&
.HYDROLOGY...
AS OF 705 PM EDT FRIDAY...
FLASH FLOOD WATCH CONTINUES THIS EVENING AND OVERNIGHT...BUT OTHER
THAN THE NORTHERN MOUNTAINS OF NORTH CAROLINA...THE FOCUS FOR THE
FLASH FLOOD CONCERN HAS SHIFTED TO LATE TONIGHT WHEN PRECIPITATION
IS EXPECTED TO ARRIVE ACROSS EASTERN PARTS OF THE AREA. THIS
EVENING...ISOLATED SHOWERS AND STORMS ACROSS CENTRAL AND EASTERN
PARTS OF THE WATCH AREA MAY PRODUCE ENOUGH HEAVY RAIN TO PROMPT
FLASH FLOODING...ESPECIALLY IF THE CELLS ARE SLOW MOVING.
AS OF 120 PM EDT FRIDAY...
THE FLASH FLOOD WATCH CONTINUES THROUGH 8 AM EDT SATURDAY. GIVEN
THE EXPECTED WET PATTERN...IT MAY BE NECESSARY TO EXTEND INTO
SUNDAY MORNING...BUT HAVE DECIDED TO TAKE THIS ON A DAY-BY-DAY
BASIS. WE WILL EVENTUALLY GET OUT OF THIS PATTERN...BUT IT COULD
BE MONDAY BEFORE THAT HAPPENS IN EARNEST. IN THE MEANTIME...FFG
VALUES ARE EXTREMELY LOW AND ALTHOUGH INTENSE/ROBUST CONVECTION
SHOULD BE LESS WIDESPREAD TODAY...RAIN WILL BE OCCURRING OVER
AREAS THAT ARE EXCESSIVELY SATURATED AND SIMPLY CANNOT TAKE ANY
MORE RAINFALL AT ALL.
RIVER FLOOD WARNING IS CANCELLED FOR THE DAN RIVER NEAR DANVILLE.
FLOOD WARNINGS IN EFFECT FOR THE FOLLOWING RIVERS IN
VIRGINIA...DAN RIVER NEAR PACES...MINOR FLOODING IS FORECAST.
MINOR FLOODING IS ALSO OCCURING ALONG THE ROANOKE RIVER AT
RANDOLPH...DAN RIVER AT SOUTH BOSTON. REFER TO LATEST FLOOD
WARNINGS...RIVER FLOOD WARNINGS AND FLOOD STATEMENTS.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR VAZ009-012>018-
022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH THROUGH SATURDAY MORNING FOR NCZ001>006-
018>020.
WV...NONE.
&&
$$
SYNOPSIS...KK/RAB
NEAR TERM...DS/KK
SHORT TERM...PH
LONG TERM...PH
AVIATION...KK/MBS/RAB
HYDROLOGY...DS/KK/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
208 AM EDT THU JUL 11 2013
.SYNOPSIS...
A DEEPENING UPPER TROUGH ACROSS THE GREAT LAKES WILL PUSH A COLD
FRONT INTO THE REGION THURSDAY. DISTURBANCES IN ADVANCE OF THIS
TROUGH WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TODAY THROUGH THURSDAY ACROSS THE REGION. BEHIND THE
COLD FRONT...COOLER...DRIER CONDITIONS ARE EXPECTED FOR FRIDAY
INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 200 AM EDT THURSDAY...
HAVE LET FFA EXPIRE AT 200 AM EDT. A NEW FFA WILL LIKELY BE
FORTHCOMING WITH THE MORNING PACKAGE...PROBABLY FOR AREAS A LITTLE
FURTHER EAST THIS TIME. WILL HIGHLIGHT DETAILS WITH LATER
DISCUSSIONS. NO OTHER CHANGES AT THIS TIME.
AS OF 800 PM EDT WEDNESDAY...
STORMS THIS EVENING HAVE BEEN VERY RAIN EFFICIENT WITH RATES OF 4
INCHES AN HOUR. THE ROANOKE REGIONAL AIRPORT RECEIVED 3.39 INCHES
OF RAIN IN ABOUT AN HOURS TIME FRAME...3.88 SO FAR FOR THE DAY...
AND NOT A GOOD MIX WHEN YOU FOCUS IT ON-TOP OF CONCRETE...WHICH
TENDS TO MAXIMIZE THE RUNOFF. WATER RESCUES SEEMED TO BECOME
COMMON PLACE THERE FOR AN HOUR OR TWO. THE ROANOKE RIVER JUMPED 5
TO 8 FEET JUST FROM THE LOCAL RUNOFF. LOOKING FOR AN EXAMPLE OF A
FLASH FLOOD... THERE YA GO.
SCATTERED SHOWERS AND STORMS WILL CONTINUE TO CONVERGE ON THE
PIEDMONT THROUGH THE EVENING HOURS WHERE THE ATMOSPHERE HAS NOT
BEEN WORKED OVER YET...CAPES STILL 1500-2000 J/KG THERE. THE LINE
OF STORMS OVER WV SHOULD WEAKEN AS THEY CROSS THE MOUNTAINS PER
STABLE AIR THAT HAS BEEN CREATED BY THE STORMS THAT OCCURRED
OVER THE CENTRAL AND WESTERN PART OF OUR CWA ALREADY. MAY SEE A
WIND GUST OF 20-30 KTS AS THE GUST FRONT ENTERS OUR WRN
COUNTIES...BUT THINK THE BIGGEST THING WE WILL HAVE TO WORRY ABOUT
IS POTENTIAL FOR ANOTHER BURST OF RAINFALL.
SURFACE COLD FRONT IS EXPECTED TO CROSS THE FORECAST AREA
THURSDAY. NOT CONFIDENT ON HOW MUCH STORM ACTIVITY WILL DEVELOP
ALONG THE FRONT PER CONVECTIVE DEBRIS THAT WILL BE LEFT IN PLACE
FROM THIS EVENINGS STORMS. PWATS WILL REMAIN HIGH...BUT THE CAPE
WILL BE DEPENDENT ON HOW QUICK THE CLOUDS BREAK THURSDAY MORNING.
WITH PWATS RANGING FROM 1.70 TO 2.0 INCHES AND A SLOW STORM
MOTION...WILL LEAVE FLASH FLOOD WATCH AS IS. FFG VALUES REMAIN
VERY LOW FROM RECENT HEAVY RAINFALL...AND THIS ADDITIONAL RAINFALL
WILL RUNOFF MORE EASILY.
USED A BLEND OF THE HRRR AND THE RNK-WRFARW FOR POPS TONIGHT INTO
THURSDAY. AS THE COLD FRONT MOVES EAST ON THURSDAY TAPER OFF POPS
FROM THE NORTHWEST TO SOUTHEAST. A STRONGER THUNDERSTORM IS POSSIBLE
IN THE SOUTH AND SOUTHEAST ON THURSDAY WITH THE POTENTIAL OF HEAVY
RAIN.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...
THURSDAY EVENING...SURFACE FRONT WILL BE WORKING ITS WAY ACROSS
THE PIEDMONT WITH MODELS TAKING THE FRONT TO THE SANDHILLS OF NC
BEFORE STALLING FRIDAY. NOT SURE HOW MUCH CLEARING WILL TAKE PLACE
BEHIND THE FRONT AS THE UPPER LEVEL FLOW BECOMES BLOCKY WITH THE
UPPER TROUGH ALSO STALLING ALOFT. AT THE VERY LEAST THINK DRYING
WILL TAKE PLACE IN THE LOWER AND MID LEVELS AS THE AS WINDS TURN
NORTHERLY...THEN NORTHEASTERLY AS SURFACE HIGH PRESSURE TRIES TO
WEDGE INTO THE AREA FROM THE NORTH. ATTM...WILL REMAIN OPTIMISTIC
AND KEEP FORECAST DRY FOR FRIDAY THROUGH AT LEAST THE FIRST HALF
OF THE WEEKEND. AT SOME POINT WINDS WILL VEER WITH SOUTHEASTERLY
FLOW BRINGING MOISTURE BACK INTO THE FORECAST.
WENT WITH THE COOLER MAV MOS WITH THE THINKING THAT MORE CLOUD
COVER AND A NORTHEASTERLY SURFACE WIND COMPONENT WILL KEEP THE
NUMBERS DOWN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 PM EDT WEDNESDAY...
CAN`T SEEM TO SHAKE THE WET PATTERN.
MODEL GUIDANCE GENERALLY AGREES THE UPPER TROUGH ALONG THE EAST
COAST WILL BECOME STUCK...POSSIBLY CUTTING OFF AND RETROGRADING
NEXT WEEK. THIS WILL QUICKLY TURN THE LOW LEVEL FLOW...WITH WINDS
CHANNELING DEEPER MOISTURE BACK INTO THE FORECAST AREA FAVORING
HIGHER POPS.
AS FOR TEMPS...DO NOT SEE ANY EXTREMES. 85H TEMPS HOVER AROUND
+16 DEG C FOR MOST OF THE WEEK. WITH A MIX OF SUN AND CLOUDS THIS
SHOULD YIELD HIGH TEMPS MAINLY IN THE 80S AND LOWS IN THE 60S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM EDT THURSDAY...
ONCE AGAIN THE MAIN CONCERN THIS TAF VALID PERIOD WILL BE
CONVECTION. GIVEN EXTENSIVE CONVECTION ACROSS THE AREA WEDNESDAY
AND LINGERING -SHRA THIS MORNING...MVFR CIGS CAN BE EXPECTED MUCH
OF THE TIME...WITH PERIODS OF VV IFR-LIFR CIGS WHERE FOG
DEVELOPS...SUCH AS POTENTIALLY AT BCB/LYH/LWB. WE ARE SEEING A
LULL IN SHRA ACTIVITY NOW...BUT EXPECT RENEWED ACTIVITY AFT 12Z
FROM W-E AS MAIN UPPER TROUGH APPROACHES THE WEST. SHOULD SEE TSRA
DEVELOP BY MID-LATE MORNING LWB-BLF...THEN SPREAD EAST TOWARD
BCB/ROA BY 16Z...THEN TOWARD LYH/DAN BY 17/18Z. EXPECT TSRA TO END
EARLIER TODAY ACROSS WESTERN AREAS...NAMELY LWB/BLF/BCB AS DRIER
AIR PUSHES IN FROM THE WEST DURING THE MID-LATE AFTERNOON.
HOWEVER...WIDESPREAD SHRA/TSRA WILL CONTINUE ACROSS EASTERN
SECTIONS THROUGH REMAINDER OF TAF VALID PERIOD. CIGS WILL
OSCILLATE FROM VFR/MVFR OUTSIDE SHRA/TSRA ACTIVITY TO MVFR/IFR IN
TSRA ACTIVITY...BUT SHOULD PREVAIL HIGH END MVFR TO LOW END VFR.
VSBYS...LOCALIZED IFR-LIFR IN MORNING FOG...BUT PREVAILING MVFR
MOST SITES OVERNIGHT. THROUGHOUT THE DAY...EXPECT VFR VSBYS
OUTSIDE SHRA/TSRA ACTIVITY...WHEN IT COULD BE MVFR-IFR FOR BRIEF
INTERVALS. WINDS SW THROUGH AFTERNOON...TRANSITIONING TO WNW BY
AFTERNOON FROM W-E. SPEEDS LESS THAN 8KTS ALL SITES...OUTSIDE
THUNDERSTORMS.
LOW TO MEDIUM CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID
PERIOD.
MEDIUM CONFIDENCE IN TSRA POTENTIAL AND TIMING THROUGH TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
MODELS INITIALLY PUSH DEEP CONVECTION TO THE COASTAL AREAS FRIDAY
AND SATURDAY WITH SOME CLEARING OVER THE APPALACHIANS IN THE WAKE
OF THE UPPER LEVEL TROF. RETURN FLOW HOWEVER...IS EXPECTED TO
BRING THE THREAT OF SHOWERS BACK INTO THE FORECAST FOR EARLY NEXT
WEEK...POSSIBLY AS EARLY AS SUNDAY. UNTIL THE MOISTURE
RETURNS...SHOULD SEE VFR CONDITIONS FOR THE FIRST HALF OF THE
UPCOMING WEEKEND...ASIDE FROM EARLY MORNING IFR BR/FG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/PM/RAB
SHORT TERM...PM
LONG TERM...PM
AVIATION...PM/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
157 AM EDT THU JUL 11 2013
.SYNOPSIS...
A DEEPENING UPPER TROUGH ACROSS THE GREAT LAKES WILL PUSH A COLD
FRONT INTO THE REGION THURSDAY. DISTURBANCES IN ADVANCE OF THIS
TROUGH WILL RESULT IN SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS TODAY THROUGH THURSDAY ACROSS THE REGION. BEHIND THE
COLD FRONT...COOLER...DRIER CONDITIONS ARE EXPECTED FOR FRIDAY
INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 800 PM EDT WEDNESDAY...
STORMS THIS EVENING HAVE BEEN VERY RAIN EFFICIENT WITH RATES OF 4
INCHES AN HOUR. THE ROANOKE REGIONAL AIRPORT RECEIVED 3.39 INCHES
OF RAIN IN ABOUT AN HOURS TIME FRAME...3.88 SO FAR FOR THE DAY...
AND NOT A GOOD MIX WHEN YOU FOCUS IT ON-TOP OF CONCRETE...WHICH
TENDS TO MAXIMIZE THE RUNOFF. WATER RESCUES SEEMED TO BECOME
COMMON PLACE THERE FOR AN HOUR OR TWO. THE ROANOKE RIVER JUMPED 5
TO 8 FEET JUST FROM THE LOCAL RUNOFF. LOOKING FOR AN EXAMPLE OF A
FLASH FLOOD... THERE YA GO.
SCATTERED SHOWERS AND STORMS WILL CONTINUE TO CONVERGE ON THE
PIEDMONT THROUGH THE EVENING HOURS WHERE THE ATMOSPHERE HAS NOT
BEEN WORKED OVER YET...CAPES STILL 1500-2000 J/KG THERE. THE LINE
OF STORMS OVER WV SHOULD WEAKEN AS THEY CROSS THE MOUNTAINS PER
STABLE AIR THAT HAS BEEN CREATED BY THE STORMS THAT OCCURRED
OVER THE CENTRAL AND WESTERN PART OF OUR CWA ALREADY. MAY SEE A
WIND GUST OF 20-30 KTS AS THE GUST FRONT ENTERS OUR WRN
COUNTIES...BUT THINK THE BIGGEST THING WE WILL HAVE TO WORRY ABOUT
IS POTENTIAL FOR ANOTHER BURST OF RAINFALL.
SURFACE COLD FRONT IS EXPECTED TO CROSS THE FORECAST AREA
THURSDAY. NOT CONFIDENT ON HOW MUCH STORM ACTIVITY WILL DEVELOP
ALONG THE FRONT PER CONVECTIVE DEBRIS THAT WILL BE LEFT IN PLACE
FROM THIS EVENINGS STORMS. PWATS WILL REMAIN HIGH...BUT THE CAPE
WILL BE DEPENDENT ON HOW QUICK THE CLOUDS BREAK THURSDAY MORNING.
WITH PWATS RANGING FROM 1.70 TO 2.0 INCHES AND A SLOW STORM
MOTION...WILL LEAVE FLASH FLOOD WATCH AS IS. FFG VALUES REMAIN
VERY LOW FROM RECENT HEAVY RAINFALL...AND THIS ADDITIONAL RAINFALL
WILL RUNOFF MORE EASILY.
USED A BLEND OF THE HRRR AND THE RNK-WRFARW FOR POPS TONIGHT INTO
THURSDAY. AS THE COLD FRONT MOVES EAST ON THURSDAY TAPER OFF POPS
FROM THE NORTHWEST TO SOUTHEAST. A STRONGER THUNDERSTORM IS POSSIBLE
IN THE SOUTH AND SOUTHEAST ON THURSDAY WITH THE POTENTIAL OF HEAVY
RAIN.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 345 PM EDT WEDNESDAY...
THURSDAY EVENING...SURFACE FRONT WILL BE WORKING ITS WAY ACROSS
THE PIEDMONT WITH MODELS TAKING THE FRONT TO THE SANDHILLS OF NC
BEFORE STALLING FRIDAY. NOT SURE HOW MUCH CLEARING WILL TAKE PLACE
BEHIND THE FRONT AS THE UPPER LEVEL FLOW BECOMES BLOCKY WITH THE
UPPER TROUGH ALSO STALLING ALOFT. AT THE VERY LEAST THINK DRYING
WILL TAKE PLACE IN THE LOWER AND MID LEVELS AS THE AS WINDS TURN
NORTHERLY...THEN NORTHEASTERLY AS SURFACE HIGH PRESSURE TRIES TO
WEDGE INTO THE AREA FROM THE NORTH. ATTM...WILL REMAIN OPTIMISTIC
AND KEEP FORECAST DRY FOR FRIDAY THROUGH AT LEAST THE FIRST HALF
OF THE WEEKEND. AT SOME POINT WINDS WILL VEER WITH SOUTHEASTERLY
FLOW BRINGING MOISTURE BACK INTO THE FORECAST.
WENT WITH THE COOLER MAV MOS WITH THE THINKING THAT MORE CLOUD
COVER AND A NORTHEASTERLY SURFACE WIND COMPONENT WILL KEEP THE
NUMBERS DOWN.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 345 PM EDT WEDNESDAY...
CAN`T SEEM TO SHAKE THE WET PATTERN.
MODEL GUIDANCE GENERALLY AGREES THE UPPER TROUGH ALONG THE EAST
COAST WILL BECOME STUCK...POSSIBLY CUTTING OFF AND RETROGRADING
NEXT WEEK. THIS WILL QUICKLY TURN THE LOW LEVEL FLOW...WITH WINDS
CHANNELING DEEPER MOISTURE BACK INTO THE FORECAST AREA FAVORING
HIGHER POPS.
AS FOR TEMPS...DO NOT SEE ANY EXTREMES. 85H TEMPS HOVER AROUND
+16 DEG C FOR MOST OF THE WEEK. WITH A MIX OF SUN AND CLOUDS THIS
SHOULD YIELD HIGH TEMPS MAINLY IN THE 80S AND LOWS IN THE 60S.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 145 AM EDT THURSDAY...
ONCE AGAIN THE MAIN CONCERN THIS TAF VALID PERIOD WILL BE
CONVECTION. GIVEN EXTENSIVE CONVECTION ACROSS THE AREA WEDNESDAY
AND LINGERING -SHRA THIS MORNING...MVFR CIGS CAN BE EXPECTED MUCH
OF THE TIME...WITH PERIODS OF VV IFR-LIFR CIGS WHERE FOG
DEVELOPS...SUCH AS POTENTIALLY AT BCB/LYH/LWB. WE ARE SEEING A
LULL IN SHRA ACTIVITY NOW...BUT EXPECT RENEWED ACTIVITY AFT 12Z
FROM W-E AS MAIN UPPER TROUGH APPROACHES THE WEST. SHOULD SEE TSRA
DEVELOP BY MID-LATE MORNING LWB-BLF...THEN SPREAD EAST TOWARD
BCB/ROA BY 16Z...THEN TOWARD LYH/DAN BY 17/18Z. EXPECT TSRA TO END
EARLIER TODAY ACROSS WESTERN AREAS...NAMELY LWB/BLF/BCB AS DRIER
AIR PUSHES IN FROM THE WEST DURING THE MID-LATE AFTERNOON.
HOWEVER...WIDESPREAD SHRA/TSRA WILL CONTINUE ACROSS EASTERN
SECTIONS THROUGH REMAINDER OF TAF VALID PERIOD. CIGS WILL
OSCILLATE FROM VFR/MVFR OUTSIDE SHRA/TSRA ACTIVITY TO MVFR/IFR IN
TSRA ACTIVITY...BUT SHOULD PREVAIL HIGH END MVFR TO LOW END VFR.
VSBYS...LOCALIZED IFR-LIFR IN MORNING FOG...BUT PREVAILING MVFR
MOST SITES OVERNIGHT. THROUGHOUT THE DAY...EXPECT VFR VSBYS
OUTSIDE SHRA/TSRA ACTIVITY...WHEN IT COULD BE MVFR-IFR FOR BRIEF
INTERVALS. WINDS SW THROUGH AFTERNOON...TRANSITIONING TO WNW BY
AFTERNOON FROM W-E. SPEEDS LESS THAN 8KTS ALL SITES...OUTSIDE
THUNDERSTORMS.
LOW TO MEDIUM CONFIDENCE IN CIGS/VSBYS THROUGH TAF VALID PERIOD.
MEDIUM TO HIGH CONFIDENCE IN WIND SPD/DIR THROUGH TAF VALID
PERIOD.
MEDIUM CONFIDENCE IN TSRA POTENTIAL AND TIMING THROUGH TAF VALID
PERIOD.
EXTENDED AVIATION DISCUSSION...
MODELS INITIALLY PUSH DEEP CONVECTION TO THE COASTAL AREAS FRIDAY
AND SATURDAY WITH SOME CLEARING OVER THE APPALACHIANS IN THE WAKE
OF THE UPPER LEVEL TROF. RETURN FLOW HOWEVER...IS EXPECTED TO
BRING THE THREAT OF SHOWERS BACK INTO THE FORECAST FOR EARLY NEXT
WEEK...POSSIBLY AS EARLY AS SUNDAY. UNTIL THE MOISTURE
RETURNS...SHOULD SEE VFR CONDITIONS FOR THE FIRST HALF OF THE
UPCOMING WEEKEND...ASIDE FROM EARLY MORNING IFR BR/FG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL 2 AM EDT EARLY THIS MORNING FOR VAZ007-
009>020-022>024-032.
NC...FLASH FLOOD WATCH UNTIL 2 AM EDT EARLY THIS MORNING FOR
NCZ001>003-018-019.
WV...FLASH FLOOD WATCH UNTIL 2 AM EDT EARLY THIS MORNING FOR
WVZ042>045.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/PM/RAB
SHORT TERM...PM
LONG TERM...PM
AVIATION...PM/RAB
AREA FORECAST DISCUSSION
NWS SPOKANE WA
712 PM PDT Fri Jul 12 2013
.SYNOPSIS...
Occasionally breezy conditions with near or slightly below normal
temperatures is expected through Saturday. There will be a
slight chance of showers and thunderstorms for tonight into Saturday,
especially around the northern mountains. Warmer temperatures are
expected next week with dry conditions except for a slight chance of
thunderstorms Tuesday night into Wednesday morning.
&&
.DISCUSSION...
Minor updates to increase cloud cover and add mention of sprinkles
to the tonight taking into consideration the current radar and
visible satellite imagery which suggests this action. Nothing very
heavy coming out of the very high based echos that are near ten thousand
feet AGL or so per surface observations. Latest two HRRR runs are
weakening the elevated convection near the northern border and
also limiting any that forms north of the border. If a few more
runs continue to trend with this decrease may issue another update
to remove the overnight thunderstorm mention. /Pelatti
&&
.AVIATION...
00Z TAFS: Cold front passage tonight keeps cloud cover and wind
fairly moderate at times. Additionally some thunderstorms may occur
late this evening and overnight over northern mountains...otherwise
VFR ceilings and visibilities through this interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 77 54 82 56 86 / 10 10 0 0 0 0
Coeur d`Alene 49 78 51 81 52 85 / 10 10 0 0 0 0
Pullman 47 76 51 83 51 85 / 10 10 0 0 0 0
Lewiston 57 85 59 91 60 95 / 10 10 0 0 0 0
Colville 48 82 51 84 51 88 / 20 10 0 0 0 0
Sandpoint 44 75 47 80 47 82 / 10 20 10 10 10 0
Kellogg 50 75 51 81 54 84 / 10 10 0 0 0 0
Moses Lake 53 83 56 89 57 90 / 10 0 0 0 0 0
Wenatchee 55 82 60 86 60 88 / 10 0 0 0 0 0
Omak 52 83 55 87 56 88 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
936 AM CDT THU JUL 11 2013
.UPDATE...
QUIET WEATHER TODAY AS SFC HIGH PRESSURE CENTERS OVER THE
FORECAST AREA. FEW CHANGES MADE...MOSTLY KEEPING TEMP/WIND/DEW
POINT TRENDS ON TRACK. ONLY CONCERN IS SKY COVER TODAY. AMDAR
SOUNDING AT AROUND 1130Z SHOWS VERY DRY AIR ALOFT THAT ISNT QUITE
BEING CAPTURED BY NEARBY RAP PROXIMITY SOUNDINGS. DOES SHOW
LINGERING MOISTURE AT LOW-LEVELS THOUGH. AS SUCH...GIVEN THIS AND
FCST SOUNDINGS...FEW-SCT DIURNAL CU STILL EXPECTED TO DEVELOP
LATER THIS MORNING.
OTHERWISE...TODAYS HIGH TEMPERATURES APPEAR FINE. SHOULD SEE MORE
THAN SUFFICIENT INSOLATION/SUNSHINE AND MIXING TODAY.
&&
.AVIATION/18Z TAFS/...VFR CONDITIONS TO PERSIST THROUGH THE TAF
PERIOD AT ALL TAF SITES. WINDS WILL BE LIGHT WITH AN ONSHORE
FLOW DEVELOPING LATE THIS MORNING. ALSO...SCT CU EXPECTED TO
DEVELOP LATE THIS MORNING...WILL TRANSITION TO FEW/CLR IN THE
AFTERNOON NEAR THE LAKE SHORE. PATCHY LIGHT FOG POSSIBLE LATER
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT THU JUL 11 2013/
SHORT TERM...
TODAY AND TONIGHT - CONFIDENCE...HIGH.
BRIEF PERIOD OF MID-CLOUDS EXPECTED OVER PORTIONS OF ERN CWA EARLY
THIS MRNG ASSOCIATED WITH VIGOROUS MID-LEVEL SHORT WAVE CURRENTLY
OVER NORTH CENTRAL WI. SPRINKLES POSSIBLE IN KFDL/KSBM AREA PRIOR
TO 12Z. SHORT WAVE MOVES RAPIDLY OFF TO THE EAST EARLY THIS MRNG
ALONG WITH MID-CLOUDS SO STILL EXPECT M/S CONDITIONS FOR MOST OF THE
DAYTIME. ENOUGH LINGERING LOW LEVEL MOISTURE TO RESULT IN SCT CU
REDEVELOPING THIS MRNG. MAY ALSO BE PERIOD OF BKN CU AWAY FROM LAKE
MICHIGAN LATER THIS MRNG BUT WL CONTINUE M/S WORDING FOR NOW.
QUIET AND COMFORTABLE CONDITIONS CONTINUE TONIGHT WITH LARGE SCALE
BLOCKING RIDGE REMAINING OVER THE CENTRAL AND PARTS OF THE WESTERN
GTLAKES. WEAK RETURN FLOW DOES INCREASE OVER WESTERN CWA DURING THE
NIGHT...HOWEVER SHOULD NOT HAVE MUCH BEARING ON OVERNIGHT TEMPS DUE
TO STRONG INVERSION. LIGHTER BOUNDARY LAYER WINDS IN EASTERN CWA MAY
RESULT IN PATCHY LIGHT FOG IN SUSCEPTIBLE AREAS LATE TONIGHT.
FRIDAY THROUGH SATURDAY...FORECAST CONFIDENCE HIGH.
SURFACE HIGH PRESSURE WILL CONTINUE TO DRIFT EAST THROUGH THE GREAT
LAKES REGION. SUNNY SKIES WILL CONTINUE ACROSS SOUTHERN WI WITH
HIGHS IN THE LOWER 80S. SOUTHEAST WINDS WILL KEEP TEMPS NEAR THE
LAKE A FEW DEGREES COOLER.
THUNDERSTORM CHANCES WITH SHORTWAVES WILL BE WELL TO OUR NORTH AND
WEST...BUT SOUTHERN WI COULD SEE SPILL OVER OF HIGHER CLOUDS AT
TIMES...ESPECIALLY SATURDAY.
LONG TERM...
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM.
THE CURRENT UPPER TROUGH DROPPING THROUGH THE GREAT LAKES REGION
THIS MORNING IS FORECAST TO CLOSE OFF OVER PENNSYLVANIA ON FRIDAY
AND THEN RETROGRADE BACK THROUGH THE MIDWEST SUNDAY THROUGH TUESDAY
AS A STRONG ATLANTIC HIGH TAKES CONTROL. ALL MODELS ARE SHOWING THIS
CLOSED UPPER LOW FEATURE. WITH ANY UPPER LOW...THERE ARE TIMING
ISSUES REGARDING ITS MOVEMENT AND ASSOCIATED PRECIPITATION.
THE LATEST 00Z ECMWF CAME IN LINE WITH THE 00Z GFS WHICH RETROGRADES
THE UPPER LOW QUICKLY INTO THE CENTRAL PLAINS BY SUNDAY AND HAS
LITTLE EFFECT ON SOUTHERN WISCONSIN WEATHER. THIS IS DIFFERENT THAN
THE 12Z ECMWF RUN WHICH HAD A SLOWER MOVEMENT AND WETTER SOLUTION
FOR SRN WI. THE 00Z CANADIAN HAS THIS SLOWER AND WETTER SOLUTION.
THE EXTENDED FORECAST USED A CONSENSUS OF MODELS THAT INCLUDED THE
12Z ECMWF. THEREFORE...THERE ARE LOTS OF SLIGHT CHANCE POPS
SPLATTERED ACROSS SOUTHERN WI FROM SUNDAY THROUGH TUESDAY. GIVEN THE
NEW 00Z ECMWF RUN...THOSE POPS WILL PROBABLY BE ABLE TO BE REDUCED
IN LATER FORECASTS. MODEL SOUNDINGS LOOK PRETTY STABLE WITH THE
UPPER LOW MOVING ACROSS THE MIDWEST...THUS PRECIP SHOULD JUST BE
SHOWERS WITH THUNDERSTORMS LESS LIKELY.
WE WERE PREVIOUSLY TALKING ABOUT A BIG WARM-UP INTO THE 90S NEXT
WEEK...BUT THAT IS BECOMING LESS LIKELY NOW DUE TO THAT CLOSED
UPPER LOW MOVING THROUGH THE REGION.
WEDNESDAY AND BEYOND...FORECAST CONFIDENCE MEDIUM.
AS THE CLOSED UPPER LOW RETROGRADES INTO THE CENTRAL PLAINS AND HIGH
PRESSURE BECOMES CENTERED OVER THE EASTERN SEABOARD...SOUTHERN WI
WILL BE THE SUBJECT OF RETURN FLOW WITH MOISTURE FLOWING UP FROM THE
GULF. THIS WILL OCCUR AT THE SAME TIME THAT THE MAIN 500MB FLOW
COULD DIP DOWN INTO CENTRAL OR SOUTHERN WI TO PRODUCE THUNDERSTORMS.
STAY TUNED.
AVIATION/12Z TAFS/...BRIEF PERIOD OF LIGHT FOG MAY AFFECT TAF SITES
EARLY THIS MORNING. OTRW EXPECTING SCT CU TO REDEVELOP THIS
MRNG...POSSIBLY TURNING BRIEFLY VFR BKN AWAY FROM LAKE SHORE LATER
THIS MRNG AND EARLY AFTN. MORE PATCHY LIGHT FOG EXPECTED LATER
TONIGHT IN LIGHTER BOUNDARY LAYER REGIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...ET
TODAY/TONIGHT AND AVIATION/MARINE...MBK
FRIDAY THROUGH WEDNESDAY...MRC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 PM CDT WED JUL 10 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 313 PM CDT WED JUL 10 2013
LATEST WATER VAPOR IMAGERY SHOWED NORTHWEST FLOW ALOFT OVER THE
REGION. AN EMBEDDED SHORTWAVE WAS NOTED OVER SOUTHERN
MANITOBA...HEADING SOUTHEAST. THIS WILL BE THE FEATURE TO KEEP A
CLOSE EYE ON LATE THIS AFTERNOON THROUGH THIS EVENING AS IT MOVES
ACROSS NORTHERN/CENTRAL WISCONSIN. ELSEWHERE ACROSS THE CONUS A
TROUGH STRETCHED FROM THE EASTERN ONTARIO SOUTH THROUGH THE OHIO
RIVER VALLEY. A RIDGE WAS NOTED OVER THE ROCKIES WITH ANOTHER
TROUGH LOCATED JUST OFF OF THE WEST COAST. SURFACE OBSERVATIONS
SHOWED HIGH PRESSURE OVER THE EASTERN DAKOTAS...EDGING EAST INTO
THE UPPER MISSISSIPPI RIVER VALLEY. THE HIGH WAS PROVIDING MOSTLY
TO PARTLY SUNNY SKIES THIS AFTERNOON ACROSS THE FORECAST AREA.
NORTHWEST WINDS ARE USHERING IN A MUCH MORE COMFORTABLE AIRMASS
WITH TEMPERATURE IN THE UPPER 70S TO LOWER 80S AND DEWPOINTS IN
THE UPPER 40S TO MIDDLE 50S.
THE SHORTWAVE TROUGH WILL MOVE ACROSS NORTHWEST WISCONSIN LATE THIS
AFTERNOON AND PUSH SOUTH INTO CENTRAL WISCONSIN DURING THE EVENING
HOURS. THE RAP AND NAM CONTINUE TO PRODUCE LIGHT PRECIPITATION
WITH THIS FEATURES. ALSO...THE UPPER LEVEL SUPPORT IS FAIRLY
HEALTHY WITH 500-300 MB POTENTIAL VORTICITY ADVECTION OF 12 TO 15
PVU/S. FORECAST SOUNDINGS OVER NORTH CENTRAL AND CENTRAL WISCONSIN
ARE RATHER DRY THIS AFTERNOON AND THIS EVENING AS HIGH PRESSURE
BUILDS IN AT THE SURFACE. GIVEN THE STRENGTH OF THE WAVE WOULD
EXPECTED TO AT LEAST GET A FEW SPRINKLES OR LIGHT SHOWERS ALONG
AND NORTHEAST OF THE INTERSTATE 94 CORRIDOR THIS EVENING...MAINLY
IN THE 8PM TO 2AM TIMEFRAME. SURFACE HIGH PRESSURE WILL DOMINATE
THE WEATHER PATTERN ACROSS THE FORECAST AREA ON THURSDAY PROVIDING
MOSTLY SUNNY SKIES AND HIGHS IN THE 79 TO 83 DEGREE RANGE. DEEP
MIXING DURING THE AFTERNOON HOURS WILL ALLOW DEWPOINTS TO FALL
INTO UPPER 40S TO LOWER 50S. HAVE LOWERED DEWPOINTS A FEW DEGREES
FROM PREVIOUS FORECAST. ALSO...WILL HAVE TO KEEP AN EYE ON AREAS
OF FOG IN THE MORNING IN VALLEY LOCATIONS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 313 PM CDT WED JUL 10 2013
THE SURFACE HIGH WILL BE CENTERED OVER THE WESTERN GREAT LAKES
THURSDAY NIGHT AS AN UPPER RIDGE BUILDS IN FROM THE NORTHERN
PLAINS WITH DRY AND QUIET WEATHER IS EXPECTED THURSDAY NIGHT INTO
FRIDAY. WARMER TEMPERATURES WILL START TO FILTER BACK INTO THE
REGION AS THE HIGH SLIDES OFF TO THE EAST AND LOW PRESSURE
DEVELOPS OVER THE PLAINS. THE BREEZY SOUTHERLY FLOW OVER THE
REGION ON FRIDAY WILL ALLOW DEEP MIXING AND TEMPERATURES TO CLIMB
INTO THE MID TO UPPER 80S UNDER MOSTLY SUNNY SKIES. THE RIDGE WILL
FLATTEN SATURDAY INTO SUNDAY AS NUMEROUS EMBEDDED SHORTWAVES IN
WEST/SOUTHWEST FLOW ALOFT TRACK ACROSS THE DAKOTAS THROUGH THE
NORTHERN HALF OF MINNESOTA INTO NORTHERN WISCONSIN. THE BULK OF
THE INSTABILITY REMAINS NORTH AND WEST OF THE FORECAST AREA. THERE
IS AN INTERESTING FEATURE ADVERTISED IN THE GEM AND ECMWF...A
RETROGRADING LOW MOVES WEST OUT OF THE CENTRAL APPALACHIANS SUNDAY
INTO MONDAY AND APPROACHES THE MIDDLE MISSISSIPPI RIVER VALLEY.
WILL HAVE TO KEEP A CLOSE WATCH ON THIS FEATURE LATE IN THE
WEEKEND GOING INTO EARLY NEXT WEEK IF IT DOES MATERIALIZE.
OTHERWISE...THE UPPER RIDGE ATTEMPTS TO ANCHOR OVER THE THE
CENTRAL CONUS...STRETCHING INTO THE UPPER MISSISSIPPI RIVER
VALLEY. ZONAL FLOW ALOFT...WITH EMBEDDED SHORTWAVES...OVER THE
DAKOTAS THROUGH THE WESTERN GREAT LAKES WILL BRING PERIODIC
CHANCES FOR SHOWERS AND THUNDERSTORMS. THE BULK OF THE ACTIVITY
SHOULD OCCUR NORTH OF INTERSTATE 90 LATE THIS WEEKEND GOING INTO
THE MIDDLE OF NEXT WEEK. WITH THE WARM SOUTHERLY FLOW OVER THE
AREA AND MUCH OF THE CONVECTIVE ACTIVITY PASSING JUST TO THE NORTH
OF THE AREA...DECIDED TO WARM HIGH TEMPERATURES 1 TO 2 DEGREES
OVER A CONSENSUS MODEL BLEND...PRODUCING HIGHS IN THE UPPER 80S TO
AROUND 90
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1148 PM CDT WED JUL 10 2013
VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST FRIDAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1112 PM MDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 905 PM MDT FRI JUL 12 2013
UPDATED TO EXPIRE THE FLASH FLOOD WATCH FOR THE WEST FORK COMPLEX.
MOST SHOWER AND THUNDERSTORM ACTIVITY HAS REMAINED OVER WESTERN
NEW MEXICO...NORTH ACROSS FAR WESTERN COLORADO AND HAS DECREASED
IN COVERAGE THIS EVENING. A FEW LIGHT SHOWERS WILL REMAIN POSSIBLE
OVER THE COMPLEX...BUT SHOULD NOT POSE A FLASH FLOOD RISK. WE WILL
CONTINUE TO MONITOR THE AREA.
ALSO ADJUSTED POPS ACROSS THE PLAINS...ALL ACTIVITY HAS DISSIPATED
WITH THE EXCEPTION OF LINCOLN COUNTY...WITH A FEW CELLS CLIPPING
CROWLEY COUNTY THROUGH 10 PM. OTHERWISE NOT SIGNIFICANT CHANGES
WERE MADE TO THE OVERNIGHT FORECAST. MOZLEY
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 246 PM MDT FRI JUL 12 2013
THUNDERSTORMS DEVELOPED EARLIER TODAY THAN PAST FEW DAYS AND ARE
DEFINITELY MORE NUMEROUS ACROSS WESTERN AREAS BENEATH THE MONSOON
PLUME...AIDED BY SHORTWAVE ENERGY LIFTING NORTHWARD OUT OF NEW
MEXICO. 4KM WRF SEEMS TO HAVE HANDLED THE CONVECTION BETTER THAN
MORNING HRRR RUNS SO FAR. BURN SCARS HAVE BEEN LARGELY MISSED AS OF
20Z...HOWEVER THAT COULD CHANGE BEFORE THE EVENING IS OUT WITH LOTS
OF ACTIVITY IN NORTHERN NM WORKING ITS WAY SLOWLY NORTHWARD. WITH
PRECIP WATERS RUNNING ANYWHERE FROM 112-185 PERCENT OF NORMAL
(HIGHEST VALUES OUT WEST)...THUNDERSTORMS THROUGH THIS EVENING WILL
BE EFFICIENT HEAVY RAINERS...WHICH WILL ELEVATE CONCERNS FOR FLASH
FLOODING ON BURN SCARS. THE WEST FORK COMPLEX IS MOST UNDER THE GUN
FOR THIS...SO WILL CONTINUE WITH THE FLASH FLOOD WATCH. WITH FLOW
ALOFT FROM THE SOUTH SOUTHWEST...MOST THUNDERSTORMS WILL BE TIED TO
THE HIGHER TERRAIN...BUT HRRR SUGGESTS AN ISOLATED SHOWER OR TWO NOT
OUT OF THE QUESTION...ESPECIALLY ALONG THE I-25 CORRIDOR AS OUTFLOWS
COME OFF THE MOUNTAINS. DUE TO THE SLOW MOVEMENT OF THUNDERSTORMS
TODAY...FLASH FLOODING WILL ALSO BE POSSIBLE ON THE BURN SCARS IN
THE EASTERN MOUNTAINS IF A STRONGER STORM WERE TO DEVELOP OVER
THEM.
THUNDERSTORMS WILL GRADUALLY DIMINISH THIS EVENING AS WE LOOSE
HEATING. WE GET TO DO IT ALL OVER AGAIN FOR SATURDAY. SOME SUBTLE
DIFFERENCES WILL BE MORE EASTERLY LOW LEVEL FLOW ACROSS NORTHERN
PORTIONS OF THE SOUTHEAST PLAINS BEHIND A WEAK FRONT WHICH DROPS IN
TONIGHT. DEW POINTS DON`T APPEAR TO BE THAT MUCH DIFFERENT FROM
TODAY...THUS LCLS ARE SIMILAR AS WELL. AND WITH UPPER HIGH CENTER
SHIFTING SOUTH OF THE AREA...STORM MOTIONS MAY ATTAIN A BIT MORE OF
A WESTERLY COMPONENT THAN TODAY WHICH MAY HELP THEM MOVE FARTHER
EAST OFF THE MOUNTAINS AND INTO THE ADJACENT PLAINS OF EL PASO
COUNTY. NAM12 IS ALSO DEVELOPING CONVECTION ACROSS THE SOUTHEAST
PLAINS ALONG THE STALLED FRONTAL BOUNDARY WHICH SETS UP ALONG A LINE
FROM ROUGHLY TRINIDAD TO LA JUNTA TO EADS. CAPES NOT ALL THAT HIGH
AND SHEARS ARE DEFINITELY WEAK...SO NOT EXPECTING THEM TO BE TOO
STRONG. HOWEVER WITH NOT MUCH CHANGE IN PRECIPITABLE WATERS...HEAVY
RAINERS WILL ONCE AGAIN BE THE MAIN THREAT WITH FLASH FLOODING
POSSIBLE ON THE AREA BURN SCARS. DIFFICULT TO PICK OUT ANY
SHORTWAVES EMBEDDED IN THE FLOW TO HELP ENHANCE COVERAGE...BUT WEST
FORK BURN SCAR MAY BE MOST UNDER THE GUN FOR FLASH FLOODING BASED ON
AVAILABLE MOISTURE. WILL LET LATER SHIFTS LOOK AT LATEST
HIGH RES MODELS BEFORE ISSUING ANY MORE FLASH FLOOD WATCHES.
WALDO...BLACK FOREST...AND OTHER BURN SCARS ACROSS THE SOUTHEAST
MOUNTAINS WILL ALSO BE UNDER THE GUN AGAIN...SO THOSE IN AND
NEAR THE BURN SCARS NEED TO MAINTAIN A HEIGHTENED AWARENESS FOR THE
POTENTIAL FOR FLASH FLOODING OVER THE WEEKEND AND ESPECIALLY INTO
SUNDAY (SEE DISCUSSION BELOW). -KT
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 246 PM MDT FRI JUL 12 2013
...HEAVY RAIN POSSIBLE SUNDAY AND INTO MONDAY...
.SUNDAY AND MONDAY...MAIN THREATS ARE POTENTIAL FOR HEAVY RAINS
AND SEE HYDRO DISCUSSION FOR MORE DETAILS.
.TUESDAY THROUGH FRIDAY...MAIN CHALLENGE IS THE AMOUNT OF
MOISTURE WHICH WILL INFLUENCE THE AMOUNT OF AFTERNOON AND EVENING
CONVECTION. THE EC AND GFS SUGGEST DRIER AIR ALOFT WILL ADVECT
INTO THE REGION FROM THE EAST AS THE UPPER LOW MOVES INTO ARIZONA
AND WEAKENS. MAIN DIFFERENCE IS THE AMOUNT OF MOISTURE WHICH
GRADUALLY MOVES NORTHWARD DURING THE LATTER PART OF THE WEEK. EC
IS STRONGER WITH THE RIDGE OVER THE WESTERN US KEEPING THE REGION
DRIER...WHILE THE GFS HAS MORE MOISTURE WITH A WEAKER RIDGE. THE
EXTENDED MODELS HAVE BEEN HAVING TROUBLE WITH THE FINER DETAILS
LATELY. FOLLOWED THE CR EXTENDED PROCEDURE CLOSELY WHICH HAS
GENERALLY SCATTERED CONVECTION OVER THE MOUNTAINS. BELIEVE THE
MOST LIKELY SOLUTION IS TO HAVE ENOUGH MOISTURE FOR CONVECTION
OVER THE MOUNTAINS...WITH MOSTLY LIGHT TO MODERATE RAINFALL
AMOUNTS. --PGW--
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1110 PM MDT FRI JUL 12 2013
VFR CONDITIONS AT ALL TERMINALS THROUGH SATURDAY LATE MORNING INTO
THE EARLY AFTERNOON. SHOWER AND THUNDERSTORMS ARE FORECAST TO
DEVELOP BY LATE MORNING AND POSSIBLY SPREAD INTO THE TERMINALS
THROUGH THE AFTERNOON AND EARLY EVENING HOURS. GUSTY OUTFLOW WINDS
WILL BE THE MAIN THREAT...WITH KALS AND KCOS BEING THE MOST LIKELY
TO SEE THUNDERSTORM ACTIVITY.
&&
.HYDROLOGY...
ISSUED AT 246 PM MDT FRI JUL 12 2013
...HEAVY RAIN POSSIBLE SUNDAY AND MONDAY...
MODELS CONTINUE TO SUGGEST THE THREAT FOR SOME HEAVY RAINFALL
SUNDAY OVER THE INTERSTATE 25 CORRIDOR AND EASTERN MOUNTAINS.
UNUSUAL WEATHER PATTERN DEVELOPING WITH UPPER LOW OVER OHIO MOVING
WESTWARD AND REACHING COLORADO BY MONDAY. BEING AN UNUSUAL WEATHER
PATTERN...HAVE NO EXPERIENCE WITH SIMILAR EVENTS. MODELS CONTINUE TO
MOISTEN THE WESTERN SIDE OF THE UPPER LOW. MODELS ARE ALSO SIMILAR
WITH A DISTURBANCE ON THE LEADING EDGE OF THE UPPER LOW REACHING
EASTERN COLORADO SUNDAY AND SUNDAY EVENING. THERE IS DEEP EASTERLY
FLOW UP TO AT LEAST 700MB SUNDAY WHICH SHOULD MOISTEN THE LOWER
LAYERS. WITH THE MOIST EASTERLY FLOW IN THE LOWER LAYERS...MOIST
AIR ALOFT AND WEAK DISTURBANCE...THE THREAT FOR HEAVY RAINS OVER
THE INTERSTATE 25 CORRIDOR AND EASTERN MOUNTAINS CONTINUE. THE
AMOUNT OF RAIN WILL DEPEND ON THE FINER DETAILS WHICH ARE STILL
EVOLVING. LATEST SIMULATIONS HAVE THE WINDS ALOFT BECOMING MORE
EASTERLY WHICH WOULD TEND TO PROPAGATE STORMS WESTWARD MORE
QUICKLY. IF THE UPPER LEVELS ARE NOT AS MOIST OR SLIGHTLY
WARMER...THEN THERE IS THE POTENTIAL FOR THE ATMOSPHERE TO REMAIN
CAPPED WITH POSSIBLY A LONGER DURATION LIGHT PRECIPITATION EVENT.
GIVEN THE SENSITIVITY OF THE BURN SCARS TO LOCAL DOWNPOURS...HAVE
DECIDED TO INCLUDE MENTION OF HEAVY RAIN IN THE ZONES AND HWO. AS
THE UPPER LOW MOVES TO THE SOUTH ON MONDAY...WARMER AND DRIER AIR
ALOFT WILL TEND TO LIMIT CONVECTION AND REDUCE THE THREAT FOR
HEAVY RAIN. AREA OF HEAVIER RAIN WILL MOVE WESTWARD..POSSIBLY
BEING CENTERED ON THE SOUTHWEST MOUNTAINS...INCLUDING THE WEST
FORK COMPLEX. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MOZLEY
SHORT TERM...KT
LONG TERM...PGW
AVIATION...MOZLEY
HYDROLOGY...PGW
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
435 AM EDT SAT JUL 13 2013
.SYNOPSIS...
A STALLED FRONT ALONG THE COAST WILL SHIFT INLAND OVER THE WEEKEND AS
BERMUDA HIGH PRES STRENGTHENS. HIGH PRESSURE WILL CONTINUE TO GRADUALLY
BUILD THROUGH THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
PRE-DAWN...WIDESPREAD CLOUDINESS AND SPRINKLES OVERNIGHT WITH A FEW
POCKETS OF HEAVIER DOWNPOURS...MAINLY ISOLATED TO THIS POINT. LOW LEVEL
MOISTURE CONVERGENCE WAS INCREASING ALONG AND E OF I-95 AT A FAST
PACE AND LATEST RUC MESOANALYSIS FROM SPC IS NOW SHOWER DEEP MOIST
CONVERGENCE ON AN UPTICK. SHOWERS WILL BE ON AN INCREASE TOWARD
DAYBREAK WITH SOME HEAVY DOWNPOURS LOCALLY ALONG AND E OF I-95.
INSTABILITY IS RATHER FEEBLE AND TSTMS PROBABLY ONLY ISOLATED AT
BEST.
ONE WORD SUMS UP THE DEEP LAYERED SYNOPTIC PATTERN TODAY...RETROGRADE.
OF COURSE FOR MOST...THE WEATHER SUMMED UP BY YET ANOTHER WORD...WET.
STRONG RIDGING OVER THE W CENTRAL ATLC WILL BUILD INTO THE NORTHEASTERN
SEABOARD TODAY...SHIFTING THE CUT-OFF MID LEVEL LOW OVER THE SOUTHERN
OHIO VALLEY AND IT/S TRAILING VORT AXIS THROUGH GEORGIA AND THE CAROLINAS
TO THE W.
WHILE MOVING SIGNIFICANT SYNOPTIC FEATURES AWAY FROM THE REGION
WOULD NORMALLY RESULT IN DECREASING RAIN CHANCES...THIS IS NOT THE
CASE TODAY. THE REASON LIES IN THE AMOUNT OF DEEP LAYERED MOISTURE
RESIDING AND PLENTY OF LOWER LEVEL CONVERGENCE ASSOCIATED WITH THE
QUASI-STATIONARY COASTAL FRONT TODAY. DIFFICULT TO ASCERTAIN HOW
MUCH DEEP CONVECTION WE GET AS INSTABILITY IS RATHER WEAK OVERALL.
CONVECTION WILL NOT HAVE TO GET TOO DEEP TO RESULT IN FLOODING
PROBLEMS DUE TO SOGGY ANTECEDENT CONDITIONS. A FLASH FLOOD WATCH
CONTINUES TODAY AS SOME OF REMNANT MOISTURE FROM CHANTAL ALSO GETS
TRANSPORTED INTO THE REGION FROM THE SOUTHEAST. PINPOINTING WHICH
AREAS HAVE THE BEST CHANCES FOR FLOODING TODAY ARE DIFFICULT WITH
THE COMPLEXITY OF THE MESOSCALE ENVIRONMENT. A HUNCH WOULD TARGET
THE COASTAL HALF OF OUR FORECAST AREA THROUGH EARLY AFTERNOON AND
PERHAPS INLAND AREAS THIS AFTERNOON AS THE FRONT NUDGES BACK
INLAND. SCATTERED AREAS SHOULD SEE 1-2 INCH RAINS WITH A FEW
LOCATIONS POTENTIALLY SEEING A WHOLE LOT MORE...ESPECIALLY IF
TRAINING OR SUBSTANTIAL MULTICELL OCCURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
RAINS SHOULD DIMINISH THIS EVENING ACROSS MANY AREAS BUT NEAR-COASTAL
SHOWERS WILL LIKELY PERSIST AND EVEN RAMP UP AGAIN LATER TONIGHT
AS LOW LEVEL CONVERGENCE STRENGTHENS IN SIGNIFICANT ONSHORE FLOW
WITH STRENGTHENING SPEED CONVERGENCE ALONG THE LAND/SEA INTERFACE.
PWATS ARE STILL OVER 2 INCHES AND THE RISK FOR HEAVY RAIN AND
ISOLATED FLOODING MAY PERSIST ALONG SOME OF OUR COASTAL COUNTIES.
SUNDAY...WE SHOULD CONTINUE TO SEE A FAIR AMOUNT OF PRECIP COVERAGE
TO START OUT THE DAY WITH LOW LVL MOISTURE ADVECTING OVER THE
AREA DUE TO ONSHORE FLOW ALONG THE WESTERN EDGE OF HIGH PRESSURE
OVER THE ATLANTIC. A MID/UPPER LVL LOW POSITIONED TO OUR NORTHWEST
WILL THEN BEGIN TO RETROGRADE TO THE CENTRAL UNITED STATES SUNDAY
AFTERNOON THROUGH TUESDAY AS A LARGE RIDGE OF HIGH PRESSURE BUILDS
OVER THE WESTERN ATLANTIC AND THE MIDWEST. THIS SWITCH IN THE
PATTERN SHOULD RESULT IN FAVORABLE UPPER LVL DIVERGENCE AND DEEP
MOISTURE SHIFTING WELL INLAND THROUGH THE PERIOD BEGINNING SUNDAY
AFTERNOON. LATEST MODELS AND SOUNDINGS INDICATE THAT DRYER AIR
WILL ARRIVE ALONG THE COAST BY SUNDAY EVENING...AND INLAND BY
SUNDAY NIGHT. WITH THIS TREND BECOMING MORE APPARENT...HAVE
MAINTAINED 30-50 POPS OVER MANY LOCATIONS SUNDAY MORNING INTO THE
EARLY AFTERNOON WHEN MOISTURE IS PRESENT AND A SEABREEZE SHIFTS
INLAND...BEFORE DECREASING POPS TO 20 ALONG COASTAL AREAS AS DRYER
AIR ENTERS THE REGION WITH THE BUILDING RIDGE FROM THE ATLANTIC
AND THE MIDWEST. THE GREATEST CHANCE AND COVERAGE OF PRECIP SHOULD
REMAIN OVER SOUTHEAST GEORGIA WHERE RIDGING ARRIVES LATE. OVERALL
HIGH TEMPS ARE EXPECTED TO REMAIN A FEW DEGREES BELOW
NORMAL...ESPECIALLY WITH SHOWER AND THUNDERSTORMS IN AREA. HIGH
TEMPS SHOULD RANGE MID/UPPER 80S...HIGHEST INLAND. OVERNIGHT LOWS
WILL REMAIN MILD...IN THE LOW 70S INLAND TO MID/UPPER 70S ALONG
THE COAST.
MONDAY AND TUESDAY...A MORE TYPICAL SUMMERTIME PATTERN IS EXPECTED
TO SETUP AS THE AREA REMAINS ALONG THE WESTERN EDGE OF ATLANTIC HIGH
PRESSURE WHILE A LARGE AND DEEP AREA OF HIGH PRESSURE EXPANDS FROM
THE MIDWEST TO THE SOUTHEASTERN UNITED STATES. ALTHOUGH DEEP
MOISTURE IS EXPECTED TO SHIFT INLAND EARLY NEXT WEEK...A CHANCE OF
SHOWERS AND THUNDERSTORMS WILL REMAIN IN THE FORECAST ON MONDAY AS
LIGHT ONSHORE FLOW MAINTAINS SUFFICIENT LOW LVL MOISTURE OVER THE
AREA WHILE FORCING OCCURS WITH A WEAK MID LVL WAVE SHIFTING ONSHORE
AND ROUNDING THE SOUTHERN EDGE OF THE HIGH CENTERED OVER THE
MIDWEST. GREATEST COVERAGE SHOULD OCCUR WITH THIS FEATURE AND AN
INLAND MOVING SEABREEZE MONDAY AFTERNOON. BY TUESDAY...THE COVERAGE
OF PRECIP SHOULD BE LESS AS THE HIGH OVER THE MIDWEST CONTINUES TO
EXPAND OVER THE EASTERN CONUS. WITH LITTLE MID/UPPER LVL SUPPORT IN
PLACE OVER THE SOUTHEAST...HAVE DECREASED POPS TO SLIGHT CHANCE OVER
ALL LOCATIONS TUESDAY AFTERNOON. OVERALL HIGH TEMPS SHOULD WARM A
FEW DEGREES OVER THE PERIOD WITH HIGHEST TEMPS ON TUESDAY AS THE
RIDGE EXPANDS OVER THE SOUTHEAST. EXPECT TEMPS TO RANGE IN THE
MID/UPPER 80S ON MONDAY...THEN MID/UPPER 80S ALONG THE COAST TUESDAY
WITH UPPER 80S TO LOWER 90S INLAND.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A FAIRLY TYPICAL SUMMERTIME PATTERN IS ANTICIPATED TUESDAY NIGHT
INTO THURSDAY AS ONSHORE FLOW OCCURS ALONG THE WESTERN EDGE OF
ATLANTIC HIGH PRESSURE. SUFFICIENT LOW LVL MOISTURE ALONG WITH
GRADUALLY WARMING TEMPS MAY PRODUCE SHOWERS/THUNDERSTORMS EACH
AFTERNOON WITH A SEABREEZE THAT PROGRESSES INLAND. OVERALL TEMPS ARE
EXPECTED TO RANGE IN THE UPPER 80S TO LOWER 90S INLAND UNDER PARTLY
CLOUDY SKIES. CHANCES OF PRECIP MAY INCREASE EARLY NEXT WEEKEND AS
LEE TROUGHING OVER THE MIDLANDS BECOMES ENHANCED BY A LOW PRESSURE
SYSTEM PASSING OVER THE NORTHEAST.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
PRIMARY VFR FOR THE VERY SHORT TERM AT KSAV. IFR CIGS HAVE RAPIDLY
DEVELOPED AT THE KCHS TERMINAL. LOWER CLOUDS AND MVFR/IFR CIGS AROUND
DAYBREAK AS SURFACE MOISTURE CONVENES ALONG THE COAST. WE RAMP UP
SHOWER CHANCES NEAR SUNRISE THROUGH THE MORNING HOURS AND THEN
TREND VCSH INTO THE AFTERNOON. SOME AREAS COULD SEE DRENCHING
RAINS AGAIN TODAY. CONFIDENCE OVERALL IS QUITE LOW GIVEN THE
ANOMALOUS MID JULY PATTERN.
EXTENDED AVIATION OUTLOOK...CHANCES OF MVFR CIGS/VSBYS ARE POSSIBLE
SUNDAY AND MONDAY WITH SHOWERS AND THUNDERSTORMS. VFR CONDITIONS ARE
THEN EXPECTED AT BOTH TERMINALS THROUGH THURSDAY.
&&
.MARINE...
TODAY WINDS/SEA CONDITIONS STARTING OFF FAIRLY TRANQUIL AS THE
GRADIENT IS WEAK IN THE FRONTAL TROUGH ACROSS THE WATERS. IT LOOKS
LIKE THE PRES GRADIENT WILL BEGIN TO TIGHTEN BETWEEN LOW PRES IN
THE NE GULF OF MEXICO AND BUILDING ATLC HIGH PRES TO THE NE BY
TONIGHT. SINCE MODELS SHOWING NOT TOO MUCH WEDGING EFFECT INLAND
OR STRONG TEMP OR MOIST GRADIENTS WE HAVE OPTED NOT TO ISSUE A
SECOND PERIOD SMALL CRAFT ADVISORY IN WATERS ADJACENT TO
CHARLESTON COUNTY. WE CAPPED CONDITIONS JUST BELOW ADVISORY
CRITERIA FOR NOW. SEAS ELSEWHERE WILL BE ON AN UPTICK AS ONSHORE
FLOW INCREASE LATER TODAY AND TONIGHT.
SUNDAY THROUGH THURSDAY...HIGH PRESSURE WILL GRADUALLY EXPAND OVER
THE WESTERN ATLANTIC EARLY NEXT WEEK...RESULTING IN A SLIGHTLY
ENHANCED PRESSURE GRADIENT OVER THE WATERS FOR MUCH OF MONDAY. AS A
RESULT...WE COULD SEE A PERIOD OF NEAR SMALL CRAFT ADVISORY LEVEL
WINDS GUSTING TO 20-25 KT AT TIMES...MAINLY OVER OUTER GEORGIA
WATERS. OTHERWISE...EAST WINDS WILL GRADUALLY BECOME SOUTH/SOUTHEAST
AND REMAIN AT OR BELOW 20 KT WITH SEAS BETWEEN 2-5 FT THROUGH
TUESDAY. CONDITIONS WILL THEN CONTINUE TO IMPROVE AND REMAIN WELL
BELOW SMALL CRAFT ADVISORY THRESHOLDS INTO MIDWEEK AS HIGH PRESSURE
DOMINATES THE COASTAL WATERS.
RIP CURRENTS...MARGINAL MODERATE RISK FOR RIP CURRENTS ALONG
COASTAL CHARLESTON COUNTY TODAY...MAINLY FOR LATER IN THE DAY
WHEN ONSHORE WINDS PICK UP.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR GAZ087-088-
099>101-114>119-137>141.
SC...FLASH FLOOD WATCH THROUGH THIS AFTERNOON FOR SCZ040-042>045-
047>052.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS TOPEKA KS
339 AM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT SAT JUL 13 2013
THE ELONGATED MID LEVEL RIDGE OBSERVED ON WATER VAPOR IMAGERY AT 08Z
SHOWS THE AXIS STRETCHED FROM NORTHERN MEXICO NORTHEASTWARD THROUGH
THE PLAINS TOWARDS THE GREAT LAKES REGION. CLOSED UPPER TROUGH OVER
THE OHIO VALLEY CONTINUES TO TRACK WESTWARD TOWARDS THE MISSISSIPPI
VALLEY WHILE MINOR EMBEDDED SHORTWAVE TROUGHS WITHIN THE RIDGE ARE
TRIGGERING CONVECTION OVER SOUTH DAKOTA INTO MINNESOTA.
CLOSER TO THE SURFACE...THE LATEST RUNS OF THE NAM12 AND RAP HAVE
SHOWN INCREASING YET WEAK ISENTROPIC LIFT ON THE 315K SURFACE WITH
WEAK MIXED LAYER CAPE NEAR 500 J/KG. THIS HAS HELPED SPARK A FEW
ISOLATED SHOWERS ACROSS PORTIONS OF NORTHEAST KANSAS THIS MORNING.
EXPECT THESE SHOWERS AND ISOLATED THUNDER TO PERSIST THROUGH THE
MORNING AND PERHAPS SATURDAY AFTERNOON HOURS FOR MUCH OF THE AREA.
UNCERTAINTY EXISTS AS TO IF THE PRECIP CAN MAINTAIN ITSELF ON
SATURDAY AFTERNOON. THE GFS/NAM/RAP/HRRR SHOW SPOTTY SHOWERS AND
THUNDERSTORMS LINGERING AS A WEAK EMBEDDED SHORTWAVE AND VORT MAX
ROTATES THROUGH NORTHERN KS WHILE THE WEAK ISENTROPIC LIFT PERSISTS
THROUGH 21Z. ON THE OTHER HAND...THESE MODELS HAVE BEEN POOR
HANDLING THE WEAK FEATURES AND EXAGGERATING PRECIP CHANCES. BELIEVE
ENOUGH CONSISTENCY BETWEEN THE MODELS AND SIGNALS OF WEAK THE
INSTABILITY AND LIFT WILL WARRANT SLIGHT CHC MENTION THROUGH 21Z
TODAY.
THE ABOVE MENTIONED CLOSED TROUGH IS PROGGED SHIFT INTO MISSOURI ON
SATURDAY EVENING. MID LEVEL MOISTURE AND HENCE CLOUD COVER WILL
INCREASE IN ADVANCE OF ITS ARRIVAL. SHOWERS AND THUNDERSTORMS
ARE ONCE AGAIN POSSIBLE AS THE TROUGH EDGES CLOSER TO THE CWA.
TIMING OF THIS TROUGH AND ASSOCIATED PRECIP IS STILL SOMEWHAT
UNCERTAIN AS THE LATEST RUN SHOWS THE NAM AND ECMWF SLOWER THAN THE
GFS. TAKING ALSO INTO ACCOUNT CONSISTENCY WITH PREVIOUS DAYS HAVE
KEPT SLIGHT CHANCES BEGINNING AT 00Z AND RAISING THE LIKELIHOOD WITH
THE INCREASING LIFT OVERNIGHT. EXPECT THE STORMS TO BE ELEVATED IN
NATURE WITH SEVERE WEATHER NOT EXPECTED.
LOOKING AT TEMPERATURES...SHOULD EXPECT A SIMILAR SATURDAY AFTERNOON
IN TERMS OF WARMTH WITH HIGHS GENERALLY IN THE LOW 90S FOR EAST
CENTRAL AND NORTHEAST AREAS...TO THE UPPER 90S OVER NORTH CENTRAL
KS. H85 MOISTURE AXIS CENTERS OVER THE AREA WITH INCREASING
DEWPOINTS IN THE MID TO UPPER 60S. HEAT INDEX READINGS THEREFORE
SHOULD MAX OUT IN THE LOW 100S OVER NORTH CENTRAL AREAS. OVERNIGHT
INCREASING CLOUDS...SCT PRECIP AND WEAKER TEMP ADVECTION SHOULD COOL
LOWS SLIGHTLY IN THE UPPER 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 339 AM CDT SAT JUL 13 2013
FOR SUNDAY...THE MODELS ARE IN GOOD AGREEMENT WITH THE CLOSED LOW
MOVING ACROSS SOUTHEAST KS INTO CENTRAL OK. THERE APPEARS TO BE
SOME DECENT MID LEVEL FRONTOGENESIS AND CONVERGENCE ALONG THE
LEADING EDGE OF THE LOW PRESSURE SYSTEM. WITH MOST MODELS
DEVELOPING A BAND OF QPF ACROSS CENTRAL KS...HAVE INCREASED POPS
DURING THE MORNING WHILE THE MESOSCALE FORCING IS ANTICIPATED.
INITIAL CLOUD COVER AND COOLER 850 TEMPS WITH SOME COLD AIR
ADVECTION IS EXPECTED TO KEEP HIGHS IN THE MID AND UPPER 80S.
FOR SUNDAY NIGHT THROUGH WEDNESDAY...THE MID LEVEL RIDGING IS
EXPECTED TO NOSE INTO EASTERN KS FROM THE EAST AS THE UPPER LOW
CONTINUES TO RETROGRADE WEST. AM NOT ALL THAT EXCITED ABOUT
CHANCES FOR PRECIP THROUGH THE PERIOD SINCE THERE IS NO OBVIOUS
FORCING OR LIFTING MECHANISM. HOWEVER FORECAST SOUNDINGS FROM THE
GFS SHOW THERE IS LITTLE TO NO CONVECTIVE INHIBITION FOR
MONDAY...TUESDAY OR WEDNESDAY. THEREFORE CANNOT RULE OUT PRECIP
ALL TOGETHER. WOULD ANTICIPATE ANY STORMS TO BE ISOLATED SO HAVE
KEPT DAYTIME POPS AT 20 PERCENT. THERE DOES NOT APPEAR TO BE A
GREAT DEAL OF WARM AIR ADVECTION THROUGH THE PERIOD...SO TEMPS ARE
FORECAST TO SHOW A VERY GRADUAL WARMING TREND AS THROUGH
WEDNESDAY.
THURSDAY AND FRIDAY SHOULD CONTINUE TO SEE THE WARMING TREND AS
THE THERMAL RIDGE BEGINS TO MOVE INTO THE PLAINS. LOWS SHOULD
AGAIN BE IN THE MID 70S WITH HIGHS IN THE LOWER TO MID 90S.
OTHERWISE RIDGING ALOFT SHOULD KEEP PRECIP CHANCES AROUND 10
PERCENT...AND WILL CONTINUE WITH A DRY FORECAST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1135 PM CDT FRI JUL 12 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. OUTSIDE CHANCE FOR A
SHOWER OR ISOLATED THUNDERSTORM GENERALLY AFTER 09Z THROUGH ABOUT
15Z AND MORE TOWARD MHK THAN TOP/FOE. TO UNCERTAIN TO ADD...WILL
MONITOR FOR UPDATES.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...67
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1106 PM MDT FRI JUL 12 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 1255 PM MDT FRI JUL 12 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 593 DM RIDGE EXTENDING
ACROSS THE PLAINS INTO THE NORTHERN MISSISSIPPI VALLEY...WITH CLOSED
576 DM LOW OVER OHIO RIVER VALLEY DOWNSTREAM...AND TROUGH IN PLACE
ACROSS PACIFIC NORTHWEST. THIS RIDGE WILL KEEP VERY HOT TEMPS IN
PLACE THE NEXT FEW DAYS WITH MINIMAL PRECIP CHANCES.
IMMEDIATE CONCERN IS VERY HOT TEMPERATURES ACROSS THE AREA THIS
AFTERNOON. SOUTHERLY FLOW HAS KEPT TD VALUES AROUND 60F IN PLACE
ACROSS THE EASTERN PART OF OUR CWA...WHICH SHOULD SUPPORT HEAT
INDICES AROUND 105F DURING PEAK HEATING. THOUGH I COULD SEE THIS AS
A MARGINAL SITUATION...PER COORDINATION AND LOCAL GUIDANCE I WENT
AHEAD AND ISSUED AT HEAT ADVISORY THROUGH 00Z.
SHORT RANGE GUIDANCE CONTINUES TO SUPPORT THUNDERSTORM INITIATION
ALONG SURFACE TROUGH AXIS NEAR OUR CWA BORDER. WITHOUT LARGE SCALE
FORCING IN PLACE...THIS ACTIVITY WILL PROBABLY BE TIED TO PEAK
HEATING...WITH CHANCES QUICKLY DIMINISHING AFTER SUNSET. I WENT
AHEAD AND INCLUDED ISO THUNDER MENTION...THOUGH CONFIDENCE IS PRETTY
LOW. LCL VALUES ARE GENERALLY IN THE 12-14KFT RANGE AND WITH DEEP
DRY LAYER BELOW WE MAY NOT ACTUALLY SEE MUCH REGARDING MEASURABLE
PRECIP WITH ANY OF THESE STORMS THAT DO DEVELOP. WITH DCAPE IN
EXCESS OF 1500 J/KG IS ALSO FORECAST BY BOTH RAP AND NAM BY THIS
AFTERNOON...SO STRONG GUSTS ARE CERTAINLY POSSIBLE WITH THESE STORMS.
SURFACE TROUGH BEGINS TO SHIFT SOUTH AND EAST SATURDAY...WHICH COULD
ALLOW SLIGHTLY COOLER TEMPS (AT LEAST SUB 100F) TO MOVE INTO THE
NORTHWEST PART OF THE CWA. THIS COULD ALSO SHIFT SW FLOW FURTHER
SOUTH KEEPING TD VALUES LOWER WHERE HIGHEST TEMPS ARE...SO CHANCE
FOR HEAT INDICES AROUND 105 SEEMS MUCH LOWER. GUIDANCE IS STILL
SHOWING THUNDERSTORMS INITIATING IN THE EARLY AFTERNOON ALONG AND
BEHIND THIS TROUGH AXIS. IT LOOKS LIKE A VERY SIMILAR SITUATION AS
TODAY WITH LITTLE IN THE WAY OF FORCING BEYOND DESTABILIZATION ALONG
TROUGH AXIS IN THE AFTERNOON/EVENING. WE COULD SEE INITIATION FURTHER
EAST DEPENDING ON TROUGH LOCATION. AT THIS TIME I DECIDED AGAINST
EXPANDING POPS TOO FAR EAST...THOUGH NAM WOULD SUPPORT ACTIVITY OVER
MOST OF OUR CWA BY 00Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 225 PM MDT FRI JUL 12 2013
UPPER FLOW WILL BE IN TRANSITION SATURDAY NIGHT AS THE RIDGE SHIFTS
EAST AND A LOW RETROGRESSES WEST INTO THE MISSOURI RIVER VALLEY. THE
UPPER LOW WILL MOVE INTO THE SOUTHERN PLAINS BY SUNDAY EVENING AND
THE TEXAS PANHANDLE MONDAY. WEAK SURFACE LOW PRESSURE IS FORECAST TO
BE OVER EASTERN COLORADO/NEW MEXICO THROUGH SUNDAY. SURFACE HIGH
PRESSURE WILL RETROGRESS WEST INTO THE CENTRAL/SOUTHERN PLAINS
SUNDAY NIGHT AND MONDAY.
THE SURFACE TROUGH IN EASTERN COLORADO WILL SERVE AS A FOCUS FOR
THUNDERSTORM INITIATION SATURDAY EVENING AS THE NEXT IMPULSE COMES
THROUGH THE FLOW. MOISTURE IS LIMITED SO WILL STAY WITH A SLIGHT
CHANCE POP. DEEP EASTERLY FLOW WILL SET UP SUNDAY/SUNDAY NIGHT WITH
CONVERGENCE OVER THE HIGHER TERRAIN OF EASTERN COLORADO. THERE IS
GOOD LIFT OVER THE HIGHER TERRAIN SO PLAN TO GO WITH SLIGHT CHANCE
OVER MOST OF THE FA WITH CHANCE POPS OVER EASTERN COLORADO. FOR NOW
WILL KEEP MONDAY MORNING DRY BUT CANNOT RULE OUT SOME LINGERING
SHOWERS IN THE FAR WESTERN PORTIONS OF THE EASTERN COLORADO
ZONES. BY MONDAY AFTERNOON A SHORTWAVE AFFECTS THE SOUTHERN
FA AS IT ROTATES AROUND THE LOW INTO THE AREA. FOR NOW WILL GO WITH
SLIGHT CHANCE POPS FOR THIS FEATURE SINCE DYNAMICS ARE WEAK AND
TRANSITIONING WESTWARD.
TEMPERATURES ARE MORE CHALLENGING WITH 850 TEMPERATURES IN THE MID
20S INSTEAD OF THE MID 30S. AT THIS TIME MAX TEMPERATURES SUNDAY
WILL BE AROUND 90 WITH MID/UPPER 80S MONDAY. DEPENDING ON HOW MUCH
PRECIPITATION AND CLOUDS ARE AROUND COOLER MAX TEMPERATURES ARE
POSSIBLE. MIN TEMPERATURES WILL RANGE FROM THE UPPER 60S/LOWER 70S
SUNDAY NIGHT TO THE MID 60S MONDAY NIGHT.
IN THE EXTENDED...(MONDAY NIGHT THROUGH FRIDAY)...UPPER FLOW WILL BE
SOUTHEASTERLY WITH THE LOW OVER NEW MEXICO. THIS LOW WILL WEAKEN
WEDNESDAY NIGHT AND THURSDAY WITH A RIDGE BUILDING OVER THE PACIFIC
NORTHWEST FRIDAY. SURFACE HIGH PRESSURE WILL BE OVER THE REGION
MONDAY NIGHT. FROM TUESDAY THROUGH FRIDAY WEAK LOW PRESSURE WILL BE
OVER EASTERN COLORADO. NUMEROUS SHORTWAVES WILL COME THROUGH THE
FLOW PRODUCING AT LEAST A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
ACROSS THE FA.
850 TEMPERATURES COOL TO THE UPPER TEENS AND MID 20S. THIS SHOULD
RESULT IN MAX TEMPERATURES RANGING FROM THE MID 80S TO AROUND 90.
MIN TEMPERATURES WILL RANGE IN THE 60S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1103 PM MDT FRI JUL 12 2013
VFR EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF PERIOD. SURFACE
WINDS WILL BE LIGHT AND VARIABLE THROUGH THE OVERNIGHT...BECOMING
SOUTHWEST SATURDAY MORNING AHEAD OF A SURFACE TROUGH NEAR THE
COLORADO-KANSAS BORDER. THUNDERSTORMS SATURDAY AFTERNOON AND
EVENING HAVE A SLIM CHANCE OF IMPACTING THE TERMINALS AS THEY
MIGRATE OUT OF EASTERN COLORADO AROUND THE UPPER RIDGE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...FS
AVIATION...024
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
202 AM EDT SAT JUL 13 2013
.SYNOPSIS...
COLD FRONT HAS STALLED ALONG THE COAST AND WILL REMAIN OVER THE
REGION THROUGH SATURDAY. HIGH PRESSURE WILL BUILD INTO THE REGION
FROM THE EAST THIS WEEKEND AS THE FRONT DISSIPATES OVER THE AREA.
HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LATEST WATER VAPOR IMAGERY INDICATES AN UPPER LOW CENTER NOW
DROPPING SSW OVER THE APPALACHIAN PLATEAU AS UPPER RIDGING
ENHANCES OVER THE WESTERN ATLANTIC. AT THE SURFACE...A 1014MB
SURFACE LOW IS SITUATED OVER DE PER MSAS ANALYSIS...WITH A TROUGH
AXIS/OLD COLD FRONT EXTENDING SSW ALONG THE COASTAL PLAIN. MUCH
OF THE AREA IS NOW RAIN-FREE ASIDE FROM SOME SCATTERED SHOWERS
OVER THE CHESAPEAKE BAY...PENINSULA...AND MIDDLE PENINSULA. GIVEN
THIS...THE FLASH FLOOD WATCH HAS BEEN CANCELLED FOR ALL THE LOCAL
AREA. THE LATEST HRRR INDICATES THE AFOREMENTIONED SHOWERS SHOULD
DISSIPATE SHORTLY AFTER MIDNIGHT...WITH ADDITIONAL SHOWERS
DEVELOPING OVER NE NC/EXTREME SE VA LATE TONIGHT/EARLY SATURDAY
MORNING AS SE FLOW RECOVERS AS THE TROUGH RETROGRADES WEST. THIS
FLOW PATTERN COULD ALSO TRIGGER SOME SHOWERS OVER THE PIEDMONT
LATER TONIGHT. OVERALL POPS SHOULD REMAIN ON THE LOW SIDE...30-40
PERCENT FOR THE AFOREMENTIONED AREAS...WITH 20 POPS ELSEWHERE.
WARM AND HUMID CONDITIONS WILL CONTINUE WITH TEMPERATURES EXPECTED
TO FALL INTO THE UPPER 60S/LOW 70S TONIGHT UNDER AN OVERCAST SKY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
MODELS CONTINUE TO HANDLE THE MID/UPPER LEVEL PATTERN WELL
THROUGH THE SHORT TERM. THE UPPER LOW WILL BECOME CUT OFF FROM THE
FLOW TONIGHT/SAT MORNING...AS HIGH PRESSURE STRENGTHENS OVER THE
CNTRL CONUS. THE LOW IS THEN PROGGED TO UNDERCUT THE
RIDGE...PROGRESSING SWWD THROUGH THE SHORT TERM TOWARD THE SRN
PLAINS. THIS WILL ALLOW UPPER/SFC HIGH PRESSURE TO BUILD INTO THE
REGION SAT...AND REMAINING CENTERED OVER THE OH VALLEY THROUGH THE
SHORT TERM. THE RESULT OVER THE LOCAL AREA WILL BE SUMMER LIKE
CONDITIONS WITH THE STORM TRACK REMAINING WELL TO THE NORTH OF THE
REGION. MOISTURE PLUME WILL MOVE INLAND AS UPPER LEVEL FLOW
BECOMES SELY SAT...WITH BEST POPS ACROSS THE PIEDMONT SAT
AFTERNOON. WHILE FORCING FOR ASCENT WILL BE SUBTLE...DIURNAL
FORCING AND ABUNDANT MOISTURE WILL RESULT IN SCATTERED SHOWERS AND
THUNDERSTORMS SAT AFTERNOON...WEST OF INTERSTATE 95. WILL KEEP
MENTION OF SLIGHT CHANCE POPS FOR THE PIEDMONT SUN AFTERNOON...BUT
BEST MOISTURE/DYNAMICS LOOKS TO BE WEST OF THE AREA. AREA WILL BE
UNDER THE INFLUENCE OF HIGH PRESSURE MON...BUT DO EXPECT MOISTURE
TO ADVECT FROM THE WRN ATLANTIC INTO THE REGION. PRESENCE OF A
WEAK LEE SIDE TROUGH AND SEA BREEZE BOUNDARIES UNDER WEAK FLOW
ALOFT...MAY RESULT IN ISOLATED-WIDELY SCATTERED THUNDERSTORMS
ACROSS THE LOCAL AREA. WILL MAINTAIN SLIGHT CHANCE POPS DURING THE
AFTERNOON FOR DIURNAL FORCING.
NEAR SEASONABLE NORMAL TEMPS SAT UNDER CLEARING SKIES FROM E TO
W. WARMING TREND WILL COMMENCE SUN AS STRONG HEIGHT RISES AND
INCREASING LOW LEVEL THICKNESS VALUES PUSH TEMPS INTO THE LOW 90S.
HOWEVER...SE FLOW WILL PREVENT TEMPS FROM REACHING THEIR FULL
POTENTIAL (HIGHS GENERALLY IN THE LOW 90S). SLIGHTLY WARMER MONDAY
AS WINDS BECOME MORE SLY (HIGHS IN THE LOW 90S). TEMPS ALONG THE
COAST DURING THE SHORT TERM WILL BE SLIGHTLY COOLER.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
HOTTER AND DRIER WEATHER EXPECTED NEXT WEEK...
MODELS ARE IN GOOD AGREEMENT SHOWING A STRONG H5 RIDGE (599DM)
RESIDING OVER THE OHIO VALLEY TUESDAY/WEDNESDAY OF NEXT WEEK. THE
RIDGE THEN SLOWLY SHIFTS EAST OVER THE MID-ATLANTIC REGION THURSDAY
BEFORE MOVING EAST TO OFF THE CAROLINA COAST BY NEXT FRIDAY. THE
POSITION AND STRENGTH OF THIS RIDGE POINTS TO A SPELL OF HOT WEATHER
ACROSS THE LOCAL AREA NEXT WEEK WITH MAX TEMPS RUNNING ABOUT 1
STANDARD DEVIATION ABOVE NORMAL (MID 90S). THIS STAGNANT AIRMASS
WILL ALSO RESULT IN WARM/MUGGY NIGHTS WITH LOWS IN THE MID/UPR 70S.
LITTLE OPPORTUNITY FOR PCPN WILL OCCUR IN THIS PATTERN AS WELL
OUTSIDE OF ISOLD CONVECTION OVER THE HIGHER TERRAIN TO OUR WEST OUR
ALONG THE AFTN SEA BREEZE. WILL GO NO HIGHER THAN SLIGHT CHC (20%)
POPS THROUGH THE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 05Z...ALL THE TAF SITES WERE VFR WITH IMPROVEMENT DURING THE
PAST SIX HOURS IN SOME CASES. STLT SHOWED VARIABLE AMOUNTS OF CLOUD
COVER WITH SOME AREAS SUCH AS SBY MOSTLY CLEAR. A BAND OF LIGHT RAIN
SHOWN ON RADAR MAY AFFECT ORF AND ECG DURING THE FIRST FEW HOURS.
PATCHY STRATUS WAS IN THE VICINITY OF SEVERAL OF THE TAF SITES AND
FOLLOWED CLOSE TO SOME THE MOS GUIDANCE. HAVE IFR COVERED AT RIC SBY
AND PHF AFT 10Z BUT LEFT ORF AND ECG NO LOWER THAN MVFR. CONDITIONS
IMPROVE AROUND 14Z.
SATURDAY SHOULD BE A RELATIVELY DRY DAY OVER EASTERN PORTIONS. THERE
WILL BE A CHANCE FOR TSTMS IN THE AFTN WITH THE HIGHEST POPS AT RIC.
LEFT PCPN OUT FOR NOW BUT WILL CONSIDER FOR THE 12Z ISSUANCE. MAINLY
CLEAR SKIES ARE INDICATED BY SATURDAY EVENING.
OUTLOOK...MAINLY DRY CONDITIONS ARE EXPECTED SUNDAY THROUGH
WEDNESDAY AND VFR SHOULD PREVAIL. CHANCES FOR FOG SUNDAY MORNING
APPEAR FAIRLY LOW BUT WILL NEED TO BE CONSIDERED...ESPECIALLY AT SBY.
&&
.MARINE...
NO HEADLINES EXPECTED THRU AT LEAST THIS WEEKEND. A FRONTAL BOUNDARY
WILL REMAIN STALLED OVER THE DELMARVA INTO SE VA THROUGH SAT BEFORE
DISSIPATING LATE IN THE DAY. WINDS HAVE BEEN SOMEWHAT VARIABLE
THIS EVENING BECOMING NLY OVER THE MIDDLE AND UPPER BAY. FORECAST
UPDATE REFLECTED THIS WIND SHIFT AS THE SURFACE LOW TRACKS INTO
THE DELMARVA. WINDS WILL GRADUALLY BECOME SLY LATER TONIGHT. BY
TOMORROW...THE DISSIPATING FRONT WILL ALLOW FOR S-SE WINDS 10-15 KT ALL
WATERS WITH A FEW GUSTS TO 20 KT POSSIBLE ACROSS THE SOUTHERN
COASTAL WATERS AND THE CURRITUCK SOUND. WAVES WILL REMAIN 1-2 FT
WITH SEAS 2-3 FT THROUGH SAT.
LATE SAT INTO THE MIDDLE OF NEXT WEEK...HIGH PRES WILL BUILD INTO
AND OVER THE MID-ATLANTIC REGION. THIS WILL RESULT IN GENERALLY S-SW
WINDS LESS THAN 15 KT. WAVES ON THE CHES BAY WILL CONTINUE TO
AVERAGE 1 TO 2 FT...WITH SEAS 2 TO 3 FT ON THE OCEAN.
&&
.HYDROLOGY...
SEVERAL ROUNDS OF HEAVY RAINFALL HAS RESULTED IN RAPID RISES IN
LOCAL RIVERS AND STREAMS. FLOOD WARNINGS WERE ISSUED FOR THE
MEHERRIN RIVER AT LAWRENCEVILLE AND THE NOTTOWAY RIVER NEAR STONY
CREEK...BOTH OF WHICH WERE CLOSE TO MINOR FLOOD LEVELS. FLOOD
WARNINGS CONTINUE FOR THE APPOMATTOX RIVER AT FARMVILLE AND
MATTOAX WHERE MINOR FLOODING IS FORECAST. THE LATEST FORECAST FOR
RICHMOND WESTHAM KEEPS THE HIGHEST STAGE JUST BELOW MINOR FLOOD
THRESHOLDS BUT AN UPDATE MAY BE NEEDED IN THE NEXT FEW HOURS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ESS/SAM
NEAR TERM...AJZ/SAM
SHORT TERM...SAM
LONG TERM...JDM
AVIATION...LSA
MARINE...JDM/JAO
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
402 AM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT SAT JUL 13 2013
AREA OF CONVECTION CONTINUES TO TRACK EAST AROUND 24 KNOTS. THE
UPPER TROUGH ASSOCIATED APPEARS TO BE WEAKENING A BIT AS IT RIDES
INTO THE RIDGE OVER THE GREAT LAKES REGION. RADAR ACTIVITY HAS
SLOWED A BIT IN THE LATEST HOUR...AND IS REGENERATING TO THE
WEST...PROBABLY AN INDICATION OF THE WAVE SLOWING AND MOVING INTO
THE RIDGE SITUATED TO THE EAST. LATEST SPC MESOSCALE ANALYSIS SHOWS
ACTIVITY ELEVATED WITH ACTIVITY DRIVEN BY WAA PATTERN WITH THE UPPER
TROUGH. DECENT MOISTURE TRANSPORT ASSOCIATED AS WELL...WITH BRIEF
DOWNPOURS WITH THE ACTIVITY. QUESTION REMAINS HOW FAR EAST THIS
WILL GO THIS MORNING BEFORE DISSIPATING. THE LATEST HRRR TRENDS
INDICATE THIS AREA WILL WORK EAST INTO WEST CENTRAL WI.
ALSO...SECONDARY AREA OF 850MB WAA REGENERATING TO THE
SOUTHWEST...INTO SOUTHEAST SOUTH DAKOTA. THIS IS AN EXTENSION TO
THE LOW LEVEL JET AND MAY BE ASSOCIATED WITH SOUTHERN SODAK WAVE
LIFTING NORTHEAST AND MOVING INTO WEST CENTRAL MN THIS
AFTERNOON...PER LATEST DETERMINISTIC MODEL TRENDS.
WILL HOLD ONTO CHANCE BUT DECREASE TO SLIGHT CHANCE THROUGH
18Z...THEN INCREASE POPS AGAIN TO THE NORTHWEST TO CHANCE AFTER
21Z...NEAREST TO THE AREA OF THE SURFACE FRONT. DESTABILIZATION WILL
OCCUR...WITH AMOUNT OF HEATING DETERMINED ON HOW MUCH SUNSHINE WILL
DEVELOP. SHOULD SEE AT LEAST SOME AS THESE SYSTEMS WANE THIS
MORNING. BEST INSTABILITY RIDES TO THE NORTHWEST BY LATE AFTERNOON
WITH SOME POSSIBILITY OF STRONG WINDS AND HEAVY RAIN INTO THE EVENING
PER LATEST SPC DAY ONE OUTLOOK.
WILL MENTION LIKELY POPS TO THE NORTHWEST AND DRIVE CHANCE POPS DOWN
A BIT FARTHER TO THE SOUTHEAST AGAIN TONIGHT...JUST IN CASE ACTIVITY
IS MORE ROBUST THAN MODELS INDICATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 309 AM CDT SAT JUL 13 2013
STRONG MID LEVEL RIDGING WILL BEGIN BUILDING WESTWARD ACROSS THE
OHIO VALLEY AND SOUTHERN GREAT LAKES SUNDAY MORNING WITH 500 MB
HEIGHTS OF NEARLY 600 DAM CENTERED OVER NERN OHIO BY AFTERNOON.
MUCH DRIER AIR WILL ACCOMPANY THIS RIDGING SO EXPECTING A SHARP
DROP OFF IN PRECIPITABLE WATER FROM EAST TO WEST DURING THE DAY.
PW COULD RANGE FROM 0.75-1.0 INCH ACROSS SRN MN/WRN WI TO
2.0-2.25 INCHES ACROSS WRN MN. MAINTAINED VERY LOW POPS AND SUNNY
SKIES OVER THE SOUTH AND EAST AND MAINTAINED MEDIUM RANGE POPS
NORTHWEST. LOW MBE VELOCITIES...VERY DEEP WARM CLOUD DEPTH...AND
HIGH PW/S ALONG THE STATIONARY FRONT COULD LEAD TO LOCALLY HEAVY
RAIN AND FLOODING. BY SUNDAY NIGHT...THE DRIER AIR WILL CONTINUE
TO ADVANCE WESTWARD AND BRING DIMINISHING CHANCES OF RAIN ACROSS
WRN MN.
THE RIDGE WILL SLOWLY SETTLE OVER NORTHERN INDIANA THROUGH THE
MIDDLE OF NEXT WEEK. THERMAL PROFILES WILL INCH UP EACH DAY AND
925 MB TEMPS BY WEDNESDAY AND THURSDAY MAY TOP +27 OR +28C. HIGHS
IN THE LOW TO MID 90S ARE A GOOD BET...AND COULD BE EVEN WARMER. PW/S
WILL ALSO INCREASE BACK TO AROUND 1.75 INCHES AND SURFACE DEW
POINTS WILL HOVER ON EITHER SIDE OF 70F. HEAT INDICES MAY BECOME
AN ISSUE BY MIDWEEK WITH READINGS POTENTIALLY EXCEEDING 100F.
CANNOT RULE OUT HEAT HEADLINES IF THIS IS TO VERIFY...PARTICULARLY
WHEN LOWS FAIL TO DROP BELOW 75 IN THE METRO.
SOMETHING THAT MAY BRING RELIEF DURING THIS PERIOD ARE LOW
PROBABILITIES OF THUNDERSTORMS. DESPITE SUCH A POTENT RIDGE...THE
PROFILE IS LACKING OF ANY SIGNIFICANT INVERSION SO WE COULD SEE
POP UP STORMS WEDNESDAY AND THURSDAY.
BY FRIDAY...THE RIDGE WILL BEGIN TO BREAK DOWN AND A COLD FRONT
WILL SAG SOUTH THROUGH THE UPPER MIDWEST. LOWER HUMIDITY AND
TEMPERATURES CLOSER TO AVERAGE ARE ANTICIPATED BY THE END OF THE
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1055 PM CDT FRI JUL 12 2013
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO WEAKEN AS THEY TRACK
SOUTHEAST ACROSS THE AREA OVERNIGHT. BY THE TIME THE ACTIVITY
REACHES EAST CENTRAL MN BETWEEN 07Z AND 10Z...SHOULD BE MOSTLY
SHOWERS WITH ISOLD THUNDER AT BEST. ATTENDANT CONDITIONS ARE NOT
EXPECTED TO GO LOWER THAN LOW-END VFR OR HIGH-END MVFR. WINDS
FROM 150-180 DEGREES WILL PREVAIL THROUGH THE PERIOD...WITH GUSTS
DEVELOPING FOR THE DAYTIME SATURDAY. THUNDERSTORM DEVELOPMENT WILL
BE POSSIBLE OVER WEST CENTRAL MN AGAIN ON SATURDAY EVE/NIGHT.
CONFIDENCE IN TIMING/LOCATION IS LOW...SO HAVE ONLY INCLUDED A
PROB30 AT KAXN AT THIS POINT.
KMSP...
WEAKENING CONVECTION IS EXPECTED TO REACH KMSP AS EARLY AS
08Z...WITH A FEW SHOWERS IN THE VICINITY OF THE SITE POSSIBLE
THROUGH 14Z. ATTENDANT CONDITIONS WOULD MOST LIKELY BE VFR.
OTHERWISE...SCT-BKN MID/HIGH CLOUDS AOA 5KFT THROUGH THE PERIOD.
WINDS 160-170 DEGREES WITH GUSTS INTO THE LOWER 20S /KNOTS/
DEVELOPING AROUND 17Z.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS S 10KT.
MON...VFR. WINDS S 5-10 KT.
TUE...VFR. WINDS SW 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...LS
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1139 PM MDT FRI JUL 12 2013
.AVIATION...
06Z TAF CYCLE
UPPER HIGH CENTER VCNTY SW KS AT 06Z WILL SHIFT BACK WWD AND OVER
NEW MEXICO NEXT 12-24 HRS. CONVECTION SHOULD CONTINUE TO WANE
ALTHOUGH ISOLD CELLS TO LINGER THROUGH 12Z ESPECIALLY ALONG AND
WEST OF THE CONTDVD WHERE MOISTURE PLUME EXISTS. MODERATE SWLY
WINDS EXPECTED OVER NORTHEAST AND EAST CENTRAL PLAINS AS LEE TROF
OVER ERN CO STRENGTHENS.
&&
.PREV DISCUSSION...911 PM MDT FRI JUL 12 2013...
QUICK UPDATE TO TWEAK POPS FOR THE EVENING PERIOD. BOUNDARY
INTERACTIONS WILL BE THE MAIN DRIVING FORCE FOR THIS EVENINGS
CONVECTION. HRRR SHOWS MOST OF TONIGHTS PRECIPITATION ACROSS
CENTRAL AND WEST CENTRAL NM...AND BASED ON CURRENT TRENDS AND
OUTFLOW BOUNDARIES...THINK THE HRRR HAS A GOOD HANDLE ON IT.
HOWEVER...ADDITIONAL THUNDERSTORMS MOVING UP FROM OLD MEXICO MAY
MOVE INTO THE SW ZONES LATE. OTHERWISE...SOME MINOR TWEAKS TO QPF
AND SKY COVER WERE MADE. UPDATES ALREADY OUT.
34
&&
.DISCUSSION...300 PM MDT FRI JUL 12 2013...
EXPECT SOUTH TO SOUTH SOUTHWEST LOW LEVEL FLOW FROM THE CENTRAL
MOUNTAINS THROUGH THE EASTERN PLAINS THIS AFTERNOON AND EVENING AS
A LEE SIDE TROUGH/LOW PRESSURE DEEPENS ACROSS SE CO AND NE NM.
ACROSS THE NORTHERN MOUNTAINS AND THE WEST EXPECT VARIABLE LOW
LEVEL FLOW FROM THE AZ STATE LINE THROUGH THE RIO GRANDE VALLEY.
VARIABLE TO GENERALLY SOUTH TO NORTH STORM MOTIONS IN THE WEST AND
NORTHERN MOUNTAINS...AROUND 10 MPH OR LESS...ALLOWING FOR GREATER
PRECIPITATION ACCUMULATION AND FLASH FLOODING POTENTIAL. ACROSS
THE EAST STORM MOTIONS WILL BE GENERALLY FROM THE SOUTH TO NORTH
AROUND 15 MPH OR GREATER. THE 12Z KABQ SOUNDING RECORDED 1.07
INCHES OF PWAT...STILL PLENTIFUL BUT NOT AS COPIOUS AS YESTERDAY.
HOWEVER...TODAY WE HAVE GREATER INSTABILITY WITH CAPE OF 1792 J/KG
COMPARED TO 760 J/KG YESTERDAY MORNING. THUS...OVERALL MORE STORMS
EXPECTED THROUGH THIS EVENING AS COMPARED TO YESTERDAY. CURRENT
GOES WATER VAPOR IMAGERY CLEARLY DEPICTS A MONSOONAL MOISTURE
PLUME CIRCULATING NORTH...AROUND THE UPPER HIGH CENTERED OVER THE
SOUTHERN PLAINS...FROM NW MEXICO ACROSS AZ/NM AND NORTH ACROSS THE
ROCKIES INTO THE NORTHERN PLAINS. THROUGH THE WEEKEND THE
MONSOONAL MOISTURE PLUME AND ATTENDANT CONVECTIVE ACTIVITY WILL BE
FOCUSED ACROSS THE SOUTHWESTERN AND WESTERN PORTIONS OF NEW
MEXICO. CONVECTION WILL BE LEAST LIKELY ACROSS THE EASTERN PLAINS
THROUGH THE WEEKEND.
EARLY NEXT WEEK... A HIGHLY UNUSUAL PATTERN DEVELOPS...WITH AN UPPER
LOW RETROGRADING ACROSS OKLAHOMA AND NORTHERN TEXAS INTO EASTERN NEW
MEXICO BY MONDAY EVENING. THIS UPPER LOW MORPHS INTO A HYBRID LOW
WITH SUBTROPICAL CHARACTERISTICS AS IT NEARS NEW MEXICO. MODELS NOW
INDICATE THAT ON MONDAY THERE IS THE POTENTIAL FOR A NORTH TO SOUTH
BAND OF RAIN TO MOVE GENERALLY FROM EAST TO WEST OR SOUTHWEST ACROSS
THE FORECAST AREA. THIS RAIN BAND IS PUSHED WEST BY A PERSISTENT EAST
OR NORTHEAST WIND DRIVEN BY A SUBSTANTIAL 14 MB EAST TO WEST SURFACE
PRESSURE GRADIENT BETWEEN THE SURFACE HEAT LOW OVER ARIZONA AND A
SURFACE HIGH PRESSURE OVER THE OK-TX PANHANDLES. SHOULD THIS OCCUR...
THERE IS A FLASH FLOOD THREAT POTENTIAL FOR PERIODS OF HEAVY
RAINFALL ACROSS THE EAST SLOPES OF THE CENTRAL MOUNTAINS...FROM
THE SACRAMENTOS TO THE SANGRE DE CRISTOS. WE WILL MONITOR THIS
THREAT POTENTIAL AS THE WEATHER PATTERN EVOLVES AND DEVELOPS.
ON TUESDAY AND WEDNESDAY THE HYBRID UPPER LOW MOVES ACROSS NEW MEXICO
THEN TRACKS SOUTH INTO CHIHUAHUA. AS IT DOES SO...THE DOOR IS OPENED
TO VERY MOIST SOUTHEASTERLY FLOW...INCREASING THE CHANCE FOR HEAVY
RAIN ACROSS THE EASTERN PLAINS AND ESPECIALLY SOUTHEASTERN PORTIONS
OF THE FORECAST AREA.
ON THURSDAY AND FRIDAY THE HYBRID UPPER LOW MIGRATES A BIT FURTHER
SOUTH INTO EAST CENTRAL CHIHUAHUA. THE UPPER HIGH IS DISPLACED NW
ACROSS WY/UT/NV...ALLOWING FOR A WEAK FLOW ALOFT OVER NM...AND AMPLE
LOW LEVEL MOISTURE. THIS PATTERN WILL SETUP A CONVECTIVE RECYCLING
MODE WITH AFTERNOON STORMS INITIATING OVER THE HIGHER TERRAIN AND A
RETURN TO SEASONAL TEMPERATURES AND PRECIPITATION CHANCES.
BENNETT
&&
.FIRE WEATHER...
ACTIVE WEATHER CONTINUING TONIGHT WITH POSSIBLY A SLIGHT DOWNTICK ON
SATURDAY AS THE UPPER HIGH SHIFTS WWD AGAIN AND OVER NEW MEXICO. FOR
SUNDAY AND INTO NEXT WEEK...MODELS STILL AGREEING ON A POTENTIALLY
ACTIVE AND WET PATTERN. AT LEAST A PORTION OF THE UPPER HIGH WILL BE
SHUNTED TO OUR WEST THANKS TO AN UPPER LOW CIRCULATION...WHICH
MODELS INDICATE WILL SLOWLY MIGRATE OVER NEW MEXICO AND THEN WEAKEN
DURING THE WORK WEEK.
THE INCREASE IN MOISTURE AND INSTABILITY ASSOCIATED WITH THE LOW AND
RESULTING PRECIPITATION SHOULD RESULT IN HIGH TEMPERATURES ACROSS
NORTHERN AND CENTRAL NEW MEXICO THAT RANGE FROM NEAR 5 TO 15 DEGREES
BELOW AVERAGE FOR MID JULY FOR NEXT MONDAY THROUGH WEDNESDAY. HIGHS
WILL REMAIN BELOW AVERAGE FOR THE REMAINDER OF NEXT WEEK...ALTHOUGH
THEY ARE PREDICTED TO BE A LITTLE WARMER AS THE UPPER LOW FADES
AWAY. ALONG WITH THE WIDESPREAD RAINFALL POTENTIAL FOR THE EARLY TO
MIDDLE PORTION OF NEXT WEEK...WILDFIRE BURN SCARS COULD BE SUBJECTED
TO REPEATED RAINFALL...SOME POSSIBLY HEAVY AT TIMES.
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
159 AM EDT SAT JUL 13 2013
.SYNOPSIS...
UPPER LOW DRIFT WEST TONIGHT INTO SATURDAY...PULLING DEEPER
MOISTURE INTO THE AREA. SOME MOISTURE REMAINS AS A HIGH AND WARM
TEMPS SET UP FOR NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATED POPS AND HOURLY TEMPERATURES. USED THE HRRR HI RES MODEL
PER SIMILARITIES ON RADAR IMAGES. STORMS COULD BE SEVERE NEAR
KANAWHA COUNTY. STORMS ARE MOVING SLOWLY WEST AROUND 5 MPH. THIS
WILL PRODUCE FLASH FLOODING OF CREEKS...SMALL STREAMS AND LOW
LYING AREAS ACROSS ROANE...PUTNAM AND KANAWHA COUNTY.
PREVIOUS DISCUSSION BELOW...
UPPER LOW OVER THE AREA TODAY AND TONIGHT...WITH A MOIST NE TO
EAST FLOW ACROSS THE CWA. CONVECTION FORMED OVER THE CENTRAL
MOUNTAINS THIS MORNING IN THE EASTERLY FLOW...AND HAS BEEN ONGOING
FOR MUCH OF THE DAY. POPS WILL GRADUALLY INCREASE IN COVERAGE AS
THE DAY PROGRESSES...AND AFTERNOON PEAK HEATING GETS INTO FULL
SWING. MAINTAINED HIGH CHANCE TO LIKELY POPS ACROSS THE
NORTH...WITH CHANCE TO SLIGHT CHANCE OF POPS ACROSS THE SOUTH AND
WEST. AT THIS POINT STILL NOT OVERLY CONCERNED ABOUT WATER ISSUES.
12Z RNK SOUNDING INDICATED PW VALUES AT 1.08 INCHES...AND SO FAR
PRECIPITATION FROM ANY ACTIVITY HAS BEEN GENERALLY LIGHT.
BULK OF CONVECTIVE ACTIVITY WILL TAPER OFF ACROSS THE AREA TONIGHT
WITH THE LOSS OF HEATING...BUT WILL CONTINUE TO MAINTAIN A SLIGHT
CHANCE ACROSS THE MOUNTAINS...PARTICULARLY NORTHERN MOUNTAIN ZONES.
IN ADDITION...SCATTERED CU FIELD SHOULD MOSTLY CLEAR OUT ACROSS THE
WEST AND SOUTH...BUT THINKING CLOUD COVER WILL HANG ON ACROSS THE
HIGHER TERRAIN COUNTIES OVERNIGHT.
UPPER LOW WILL BEGIN TO PUSH OFF TO THE SOUTH AND EAST LATER TONIGHT
AND ON SATURDAY...AS UPPER LEVEL RIDGE NUDGES IN FROM THE EAST. THIS
WILL LEAD TO A TREND OF WARMER TEMPERATURES...AND SOMEWHAT DRIER
WEATHER...ALTHOUGH SHOWERS AND STORMS WILL CONTINUE PARTICULARLY
DURING THE PEAK HEATING HOURS. MADE NO MAJOR CHANGES TO THE PREVIOUS
TEMPERATURE FORECAST OTHER THAN MINOR TWEAKS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THE UPPER LEVEL LOW WILL CONTINUE TO DRIFT SOUTH AND WEST DUE TO A
FAIRLY STRONG HIGH PRESSURE BUILDING ACROSS THE AREA FROM THE EAST.
STILL EXPECT DIURNAL SHOWERS AND THUNDERSTORM THROUGH THE PERIOD
WITH TEMPERATURE BEGINNING TO WARM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
SUMMER PATTERN CONTINUES WITH A 598/599 MB HIGH OVER THE AREA. EVEN
THOUGH THE FORECAST AREA HAS BEEN WET IT WON/T TAKE LONG TO DRY OUT
BEING JULY. EXPECT WARM TEMPERATURES FOR THE FORECAST
AREA...POSSIBLE THE WARMEST TEMPERATURES SO FAR THIS SUMMER. RAISED
AFTERNOON HIGHS AND DEW POINTS. THERE WILL STILL BE MOISTURE AROUND
THE AREA TRAPPED UNDER THE HIGH THUS DIURNAL POPS. THE RIDGE BEGINS
TO FLATTEN OUT ON THURSDAY AND FRIDAY AS THE NEXT FRONTAL SYSTEM
APPROACHES THE OHIO VALLEY BY FRIDAY. TIMING WITH THE FRONT IS
STILL IFFY AS IT IS SEVEN DAYS OUT.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
06Z SATURDAY THROUGH 06Z SUNDAY...
E TO ESE LLVL FLOW ARND PESKY UPR LOW WILL ALLOW FOR MAINLY MVFR
STRATUS EARLY THIS MORNING ACROSS THE MTNS WITH KBKW PERHAPS COMING
DOWN INTO IFR. ELSEWHERE...A COMBINATION OF MVFR FG AND IFR TO LIFR
CIGS FOR AREAS THAT SAW RA YESTERDAY...INCLUDING KCRW AND KCKB.
STRATUS/FG WILL LIFT AFTER SUNRISE INTO MAINLY BKN MVFR CU AND LOW
END VFR CU FIELD TDY. UPR LOW OVER WILL BEGIN TO ACCELERATE TO W
TDY. HOWEVER...DEEP MOIST SE FLOW WILL ALLOW FOR SHRA/TSRA TO BREAK
OUT BY MIDDAY ACROSS THE MTNS AND TRACKING W TO PERHAPS OH RVR BY
00Z. WILL CARRY VCTS FOR MOST OF TAF SITES EXCEPT KHTS AND KBKW FOR
NOW.
ANY SHRA/TSRA WILL WANE BY 03Z WITH MORE LOW STRATUS ACROSS E SLOPES
AND PERHAPS KBKW. OTHERWISE HAVE SOME MVFR FG IN TAFS WITH SOME SCT
4 TO 5 THSD FOOT CLDS.
FORECAST CONFIDENCE...LOW.
ALTERNATE SCENARIOS: TIMING AND INTENSITY OF IFR CEILINGS OR FOG
AS WELL AS LOW CEILINGS COULD BE DIFFERENT THAN FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE SAT 07/13/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M M M M M M M H H H H H
BKW CONSISTENCY M M M L M M M H M M M H
EKN CONSISTENCY L L L L L L L H H H M H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z SUNDAY...
IFR IN FOG POSSIBLE SATURDAY NIGHT. BRIEF IFR IN THUNDERSTORMS OVER THE
WEEKEND.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...FB/SL
NEAR TERM...ARJ/SL
SHORT TERM...RPY
LONG TERM...FB
AVIATION...30
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1036 PM MDT FRI JUL 12 2013
.UPDATE...
ISSUED AT 859 PM MDT FRI JUL 12 2013
SFC FRONT HAS PROGRESSED SOUTH INTO CENTRAL NE AND IS IN THE
STAGES OF STALLING. MEANWHILE A WEAK IMPULSE IS EJECTING NE FROM
THE NE PANHANDLE...SUPPORTING A POS THETA-E REGIME
THERE...SPREADING NE INTO NORTHERN NE AND EVENTUALLY SCENTRAL SD.
ONGOING LINEAR TS COMPLEX SHOULD CONTINUE NE OVERNIGHT...ARRIVING
IN SCENTRAL SD LATE TONGIHT. THIS IS IN LINE WITH SUGGESTED MODEL
FORECAST PROGS...PARTICULARLY THE HRRR AND RAP. HAVE INCREASED
POPS TO 40 THERE. OTHERWISE...WEAKER IMPULSE NOW TRAVERSING
WESTERN SD AND NE WY WILL PROGRESS NE WITH HIGH BASED MONSOON
ORIGIN MOISTURE SUPPORTING ISOLD SHRA. ALL ELSE ON TRACK.
&&
.SHORT TERM...THIS EVENING THROUGH SATURDAY NIGHT
ISSUED AT 253 PM MDT FRI JUL 12 2013
A POSITIVELY TILTED UPPER RIDGE REMAINS STRETCHED ACROSS THE CENTRAL
PLAINS...RESULTING IN SOUTHWEST FLOW ACROSS THE CWA. 20Z SURFACE
ANALYSIS HAS COLD FRONT ALMOST TO KICR AND KVTN AS WINDS HAVE GONE
WESTERLY OVER THE LAST HOUR. LATEST RADAR IMAGERY SHOWS CONVECTION
FIRING IN SOUTHEASTERN WYOMING AND IN THE BIGHORN MOUNTAINS.
FOR THE REST OF THIS AFTERNOON...WILL CONTINUE HEAT ADVISORY FOR
TRIPP COUNTY. THE TEMP IS 95 AT KICR WITH A DEWPOINT OF 67
RESULTING IN A HEAT INDEX RIGHT AROUND 100 DEGREES.
FOR TONIGHT...A WEAK WAVE WILL PUSH THOUGH NORTHEASTERN WYOMING AND
THE BLACK HILLS OVERNIGHT. WITH CONVECTION ALREADY FIRING NEAR THIS
WAVE...EXPECT SHOWERS AND THUNDERSTORMS TO MOVE ACROSS THIS AREA
TONIGHT. FORECAST SOUNDINGS IN THIS AREA ALSO SHOW AN INVERTED V
TYPE PROFILE...THUS WE MAY SEE SOME GUSTY WINDS WITH THESE STORMS.
NOT EXPECTING TOO MUCH DRY LIGHTNING SINCE PW VALUES ARE 135 PERCENT
OF NORMAL.
MONSOONAL FLOW BRINGS AMPLE MOISTURE INTO THE CWA SATURDAY AS
THETA-E RIDGE BUILDS BACK INTO THE AREA. SEVERAL EMBEDDED SHORTWAVES
WILL PASS THROUGH THE AREA...WITH SOME STRONGER ENERGY PROGGED
ACROSS THE REGION SATURDAY NIGHT. SOUTHERN END OF THE COLD FRONT
THAT MOVED THROUGH THIS MORNING WILL WRAP AROUND THE WEST SIDE OF
THE HILLS AND PUSH THROUGH THE AREA AS A TROUGH/WARM FRONT. MLCAPE
OF 1500 TO 2500 J/KG BY AFTERNOON ALONG WITH DIURNAL HEATING AND
DEBSTABILIZATION WILL BE ENOUGH TO FIRE SOME THUNDERSTORMS. THE
0-6KM SHEAR LOOKS TO BE 35-40KTS SUGGESTING ORGANIZED MULTI-CELLULAR
AND SUPER-CELLULAR STORMS. AS THE LOW-LEVEL JST INCREASES DURING THE
EVENING...THESE STORMS WILL CONTINUE OVERNIGHT. WITH PWAT/S FROM
100-150 PERCENT OF NORMAL...LOCALLY HEAVY RAIN MAY OCCUR.
TEMPERATURES WILL BE NEAR GUIDANCE.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
ISSUED AT 253 PM MDT FRI JUL 12 2013
MONSOONAL FLOW PATTERN WILL REMAIN OVER THE REGION INTO EARLY
NEXT WEEK...BRINGING A GOOD CHANCE FOR THUNDERSTORMS SUNDAY INTO
MONDAY. THERE LOOKS TO BE A THREAT FOR STRONG TO SEVERE STORMS
BOTH DAYS...ESPECIALLY ACROSS NORTHERN AND WESTERN PORTIONS OF THE
CWA...ALONG WITH LOCALLY HEAVY RAIN. A DRIER PATTERN WILL DEVELOP
BEYOND MONDAY...AS THE UPPER RIDGE HOLDS ACROSS THE CENTRAL CONUS.
TEMPERATURES WILL BE NEAR AVERAGE LEVELS FOR SUNDAY AND
MONDAY...WITH ABOVE AVERAGE TEMPERATURES THEN LIKELY THROUGH THE
REST OF THE LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1021 PM MDT FRI JUL 12 2013
INCREASING DEEP LAYER MOISTURE WILL SUPPORT INCREASING CHANCES FOR
SHOWERS AND THUNDERSTORMS IN THE PERIOD AS ACTIVE SW FLOW
CONTINUES OVER THE REGION. MAINLY VFR CONDITIONS CAN BE EXPECTED
OVER MOST OF THE REGION. HOWEVER...LOCAL MVFR TO IFR CONDITIONS
CAN BE EXPECTED IN AND NEAR THUNDERSTORMS. THERE WILL ALSO BE THE
POTENTIAL FOR POCKETS OF LOW STRATUS LATE TOMORROW NIGHT.
&&
.HYDROLOGY...
ISSUED AT 253 PM MDT FRI JUL 12 2013
MONSOONAL FLOW BRINGS AMPLE MOISTURE INTO THE CWA BEGINNING
TONIGHT AND CONTINUING THROUGH THE WEEKEND. WITH PWAT/S FROM
100-150 PERCENT OF NORMAL...LOCALLY HEAVY RAIN MAY OCCUR WITH
THUNDERSTORMS THIS WEEKEND. WILL HOLD OFF ON ANY HYDRO PRODUCTS AT
THIS TIME AS THE TIMING AND AREA IS STILL UNCERTAIN.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...JC
SHORT TERM...MLS
LONG TERM...15
AVIATION...JC
HYDROLOGY...MLS
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 SPOKANE WA
1005 PM PDT Fri Jul 12 2013
.SYNOPSIS...
Occasionally breezy conditions with near or slightly below normal
temperatures is expected through Saturday. There will be a
slight chance of showers and thunderstorms for tonight into Saturday,
especially around the northern mountains. Warmer temperatures are
expected next week with dry conditions except for a slight chance of
thunderstorms Tuesday night into Wednesday morning.
&&
.DISCUSSION...
Radar showing enhancement in vicinity of Omak and the HRRR runs
from the past three hours of so suggest this is the beginning of
elevated forced convection that should continue through the
overnight hours. Thus have left the mention of thunderstorms but
also added more mention of sprinkles further west with this late
evening update.
&&
.AVIATION...
06Z TAFS: Cold front passage tonight keeps cloud cover and wind
fairly moderate at times along with some overnight and early
morning thunderstorms over northern mountains...otherwise VFR
ceilings and visibilities through this interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 77 54 82 56 86 / 10 10 0 0 0 0
Coeur d`Alene 49 78 51 81 52 85 / 10 10 0 0 0 0
Pullman 47 76 51 83 51 85 / 10 10 0 0 0 0
Lewiston 57 85 59 91 60 95 / 10 10 0 0 0 0
Colville 48 82 51 84 51 88 / 20 10 0 0 0 0
Sandpoint 44 75 47 80 47 82 / 10 20 10 10 10 0
Kellogg 50 75 51 81 54 84 / 10 10 0 0 0 0
Moses Lake 53 83 56 89 57 90 / 10 0 0 0 0 0
Wenatchee 55 82 60 86 60 88 / 10 0 0 0 0 0
Omak 52 83 55 87 56 88 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
327 AM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1120 PM CDT FRI JUL 12 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SOME THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER CENTRAL-SOUTHERN MN OVERNIGHT. THE
MOTION OF THE THUNDERSTORMS WOULD BE EAST TOWARD KRST HOWEVER THE
INSTABILITY RAPIDLY DROPS OFF WEST OF KRST. THEREFORE...A
DIMINISHING TREND TO THE TSRA ACTIVITY AS IT MOVES SOUTHEAST
TOWARD KRST/KLSE IS EXPECTED...WITH ONLY VFR CLOUDS REMAINING AND
POSSIBLY SHRA AROUND SUNRISE.
THUNDERSTORMS ONGOING WILL CAUSE A THICK COVER OF CIRRUS AT HIGH
LEVELS. WILL MONITOR THE TSRA ACTIVITY OVERNIGHT...BUT CURRENTLY
EXPECT A DIMINISHING TREND AND LITTLE EFFECT AT THE AIRPORTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1052 AM EDT SAT JUL 13 2013
.UPDATE...
RAIN SO FAR HAS BEEN CONFINED TO EASTERN GA. THINK THE HRRR IS
DECENT IS TERMS OF WHAT IT IS SHOWING FOR TODAY. SHOULD SEE
DEVELOPMENT OF SCATTERED SHOWERS ACROSS THE REMAINDER OF THE CWA
AROUND NOONTIME. CURRENT POP TRENDS LOOK REASONABLE. MAIN CONCERN
WITH THE FORECAST FOR TODAY IS POTENTIAL FOR LOCALIZED FLOODING.
ALTHOUGH OVERALL RAINFALL AMOUNTS ARE EXPECTED TO BE ON THE LOWER
SIDE...LOCALIZED HIGHER AMOUNTS ARE POSSIBLE WITH TRAINING.
ALREADY HAVE LOCALIZED FLOODING ACROSS PARTS OF EASTERN GA...AND
WILL BE INVESTIGATING THIS MORE FOR THE POTENTIAL NEED OF A FLASH
FLOOD WATCH ACROSS EASTERN GA.
11
&&
.PREV DISCUSSION...
SHORT TERM /TODAY THROUGH SUNDAY/...
/ISSUED 422 AM EDT SAT JUL 13 2013/
NAM/GFS IN DECENT AGREEMENT WITH MOVING LOW PRESSURE ALOFT OVER THE
OH/TN VALLEY WEST ACROSS THE MS VALLEY THROUGH EARLY SUNDAY WITH
UPPER HIGH PRESSURE BUILDING OVER THE NE STATES LATE TODAY THROUGH
SUNDAY. THIS ALLOWS DEEPER MOISTURE TO MOVE BACK OVER THE AREA FROM
THE SE TODAY AND TONIGHT AND CONTINUE OVER THE AREA FOR SUNDAY.
THE POTENTIAL FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
WILL INCREASE ACROSS THE AREA ESPECIALLY FROM LATE MORNING
ON...INCREASING HIGHEST OVER THE SE 2/3RDS OF THE FORECAST AREA.
THINK CONVECTION WILL BE SLOW TO WIND DOWN OVERNIGHT WITH SOME
CHANCE FOR SHOWERS THROUGHOUT THE LATE NIGHT. NUMEROUS SHOWERS AND
THUNDERSTORMS CAN BE EXPECTED FOR SUNDAY...TENDING TO MAXIMIZE
DURING THE AFTERNOON...AS ABUNDANT MOISTURE AND DECENT INSTABILITY
WILL BE IN PLACE.
MOS POPS FOR N AND PARTS OF CENTRAL GA SEEM TOO LOW FOR TODAY AND
HAVE STAYED CLOSER TO CURRENT FORECAST.
FORECAST HIGH TEMPERATURES RUNNING ABOUT 5-8 DEGREES BELOW NORMAL
TODAY AND SUNDAY. FORECAST LOW TEMPERATURES RUNNING CLOSE TO NORMAL.
OVERALL CONFIDENCE IS MEDIUM TO HIGH.
BDL
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
/ISSUED 422 AM EDT SAT JUL 13 2013/
UPPER LOW MOVING WEST AT THE START OF THE PERIOD WITH STRONG UPPER
RIDGE OVER THE NORTHEAST. TROPICAL MOISTURE STILL BEING DRAWN MOVING
ACROSS THE CWA AT DURING THE FIRST OF THE WEEK. A DEEP EASTERLY
FLOW PATTERN WILL KEEP ATLANTIC MOISTURE OVER THE CWA THROUGH MUCH
OF THE PERIOD. THE FLOW BECOMES MORE SOUTHWESTERLY BY THURSDAY
INTO FRIDAY AS THE UPPER RIDGE WEAKENS A BIT A SHIFTS SOUTHWARD.
IN GENERAL...HAVE BASICALLY KEPT CHANCE POPS EACH DAY WITH SLIGHT
CHANCE OVERNIGHT THROUGH THE PERIOD. A DIURNAL PATTERN SHOULD
BECOME MORE PROMINENT THROUGH THE WEEK...WITH AFTERNOON
TEMPERATURES BECOMING A BIT WARMER.
41
HYDROLOGY...
/ISSUED 422 AM EDT SAT JUL 13 2013/
NO CONFIDENCE FOR A FLASH FLOOD WATCH AT THIS TIME. HOWEVER MOST
THUNDERSTORMS WILL BE ABLE TO PRODUCE HEAVY RAIN AND IF THEY ARE
SLOW MOVERS OR TRAIN OVER THE SAME AREA...LOCALIZED FLASH FLOODING
WILL BE POSSIBLE. AVERAGE RAINFALL AMOUNTS THE NEXT COUPLE DAYS WILL
BE 1 INCH OR LESS.
AVIATION...
12Z UPDATE...
/ISSUED 722 AM EDT SAT JUL 13 2013/
IFR-MVFR CEILINGS GENERALLY IMPROVING TO VFR THROUGH THE MORNING.
SHOWERS AND STORMS EXPECTED TO INCREASE ACROSS THE AREA THROUGH
THE DAY AND CONTINUING IN SOME FASHION THROUGH THRU OVERNIGHT.
SURFACE WINDS MOSTLY ENE NEAR 10 KTS EXCEPT STRONGER AND GUSTY
NEAR THUNDERSTORMS.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE FOR IFR CIGS IMPROVING THIS MORNING AND WINDS.
LOW-MEDIUM CONFIDENCE ON TIMING AND IMPACTS OF THUNDERSTORMS.
BDL
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 83 69 84 70 / 60 60 70 20
ATLANTA 84 70 83 70 / 50 50 70 30
BLAIRSVILLE 81 67 81 65 / 50 50 70 20
CARTERSVILLE 86 69 85 70 / 50 50 70 30
COLUMBUS 85 72 87 73 / 50 50 70 40
GAINESVILLE 81 70 82 70 / 60 60 70 20
MACON 85 70 88 70 / 60 50 70 30
ROME 87 70 86 70 / 40 40 70 40
PEACHTREE CITY 84 70 84 69 / 50 50 70 40
VIDALIA 84 71 88 72 / 70 50 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...11
LONG TERM....ARG
AVIATION...11
AREA FORECAST DISCUSSION
NWS TOPEKA KS
607 AM CDT SAT JUL 13 2013
...UPDATE TO AVIATION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT SAT JUL 13 2013
THE ELONGATED MID LEVEL RIDGE OBSERVED ON WATER VAPOR IMAGERY AT 08Z
SHOWS THE AXIS STRETCHED FROM NORTHERN MEXICO NORTHEASTWARD THROUGH
THE PLAINS TOWARDS THE GREAT LAKES REGION. CLOSED UPPER TROUGH OVER
THE OHIO VALLEY CONTINUES TO TRACK WESTWARD TOWARDS THE MISSISSIPPI
VALLEY WHILE MINOR EMBEDDED SHORTWAVE TROUGHS WITHIN THE RIDGE ARE
TRIGGERING CONVECTION OVER SOUTH DAKOTA INTO MINNESOTA.
CLOSER TO THE SURFACE...THE LATEST RUNS OF THE NAM12 AND RAP HAVE
SHOWN INCREASING YET WEAK ISENTROPIC LIFT ON THE 315K SURFACE WITH
WEAK MIXED LAYER CAPE NEAR 500 J/KG. THIS HAS HELPED SPARK A FEW
ISOLATED SHOWERS ACROSS PORTIONS OF NORTHEAST KANSAS THIS MORNING.
EXPECT THESE SHOWERS AND ISOLATED THUNDER TO PERSIST THROUGH THE
MORNING AND PERHAPS SATURDAY AFTERNOON HOURS FOR MUCH OF THE AREA.
UNCERTAINTY EXISTS AS TO IF THE PRECIP CAN MAINTAIN ITSELF ON
SATURDAY AFTERNOON. THE GFS/NAM/RAP/HRRR SHOW SPOTTY SHOWERS AND
THUNDERSTORMS LINGERING AS A WEAK EMBEDDED SHORTWAVE AND VORT MAX
ROTATES THROUGH NORTHERN KS WHILE THE WEAK ISENTROPIC LIFT PERSISTS
THROUGH 21Z. ON THE OTHER HAND...THESE MODELS HAVE BEEN POOR
HANDLING THE WEAK FEATURES AND EXAGGERATING PRECIP CHANCES. BELIEVE
ENOUGH CONSISTENCY BETWEEN THE MODELS AND SIGNALS OF WEAK THE
INSTABILITY AND LIFT WILL WARRANT SLIGHT CHC MENTION THROUGH 21Z
TODAY.
THE ABOVE MENTIONED CLOSED TROUGH IS PROGGED SHIFT INTO MISSOURI ON
SATURDAY EVENING. MID LEVEL MOISTURE AND HENCE CLOUD COVER WILL
INCREASE IN ADVANCE OF ITS ARRIVAL. SHOWERS AND THUNDERSTORMS
ARE ONCE AGAIN POSSIBLE AS THE TROUGH EDGES CLOSER TO THE CWA.
TIMING OF THIS TROUGH AND ASSOCIATED PRECIP IS STILL SOMEWHAT
UNCERTAIN AS THE LATEST RUN SHOWS THE NAM AND ECMWF SLOWER THAN THE
GFS. TAKING ALSO INTO ACCOUNT CONSISTENCY WITH PREVIOUS DAYS HAVE
KEPT SLIGHT CHANCES BEGINNING AT 00Z AND RAISING THE LIKELIHOOD WITH
THE INCREASING LIFT OVERNIGHT. EXPECT THE STORMS TO BE ELEVATED IN
NATURE WITH SEVERE WEATHER NOT EXPECTED.
LOOKING AT TEMPERATURES...SHOULD EXPECT A SIMILAR SATURDAY AFTERNOON
IN TERMS OF WARMTH WITH HIGHS GENERALLY IN THE LOW 90S FOR EAST
CENTRAL AND NORTHEAST AREAS...TO THE UPPER 90S OVER NORTH CENTRAL
KS. H85 MOISTURE AXIS CENTERS OVER THE AREA WITH INCREASING
DEWPOINTS IN THE MID TO UPPER 60S. HEAT INDEX READINGS THEREFORE
SHOULD MAX OUT IN THE LOW 100S OVER NORTH CENTRAL AREAS. OVERNIGHT
INCREASING CLOUDS...SCT PRECIP AND WEAKER TEMP ADVECTION SHOULD COOL
LOWS SLIGHTLY IN THE UPPER 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 339 AM CDT SAT JUL 13 2013
FOR SUNDAY...THE MODELS ARE IN GOOD AGREEMENT WITH THE CLOSED LOW
MOVING ACROSS SOUTHEAST KS INTO CENTRAL OK. THERE APPEARS TO BE
SOME DECENT MID LEVEL FRONTOGENESIS AND CONVERGENCE ALONG THE
LEADING EDGE OF THE LOW PRESSURE SYSTEM. WITH MOST MODELS
DEVELOPING A BAND OF QPF ACROSS CENTRAL KS...HAVE INCREASED POPS
DURING THE MORNING WHILE THE MESOSCALE FORCING IS ANTICIPATED.
INITIAL CLOUD COVER AND COOLER 850 TEMPS WITH SOME COLD AIR
ADVECTION IS EXPECTED TO KEEP HIGHS IN THE MID AND UPPER 80S.
FOR SUNDAY NIGHT THROUGH WEDNESDAY...THE MID LEVEL RIDGING IS
EXPECTED TO NOSE INTO EASTERN KS FROM THE EAST AS THE UPPER LOW
CONTINUES TO RETROGRADE WEST. AM NOT ALL THAT EXCITED ABOUT
CHANCES FOR PRECIP THROUGH THE PERIOD SINCE THERE IS NO OBVIOUS
FORCING OR LIFTING MECHANISM. HOWEVER FORECAST SOUNDINGS FROM THE
GFS SHOW THERE IS LITTLE TO NO CONVECTIVE INHIBITION FOR
MONDAY...TUESDAY OR WEDNESDAY. THEREFORE CANNOT RULE OUT PRECIP
ALL TOGETHER. WOULD ANTICIPATE ANY STORMS TO BE ISOLATED SO HAVE
KEPT DAYTIME POPS AT 20 PERCENT. THERE DOES NOT APPEAR TO BE A
GREAT DEAL OF WARM AIR ADVECTION THROUGH THE PERIOD...SO TEMPS ARE
FORECAST TO SHOW A VERY GRADUAL WARMING TREND AS THROUGH
WEDNESDAY.
THURSDAY AND FRIDAY SHOULD CONTINUE TO SEE THE WARMING TREND AS
THE THERMAL RIDGE BEGINS TO MOVE INTO THE PLAINS. LOWS SHOULD
AGAIN BE IN THE MID 70S WITH HIGHS IN THE LOWER TO MID 90S.
OTHERWISE RIDGING ALOFT SHOULD KEEP PRECIP CHANCES AROUND 10
PERCENT...AND WILL CONTINUE WITH A DRY FORECAST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 543 AM CDT SAT JUL 13 2013
VFR CONDITIONS EXPECTED AT KTOP/KFOE/KMHK WITH SCT SHOWERS AND ISOLATED
-TSRA SHIFTING SOUTHWARD TOWARDS KMHK. INSERTED A TEMPO GROUP AT
KMHK THRU 14Z AS COVERAGE OF THUNDER IS WIDELY SCATTERED. THERE IS AN
OUTSIDE POSSIBILITY FOR ADDITIONAL TSRA TO DEVELOP LATER THIS
MORNING OTHERWISE FOCUS THEN TURNS TO OVERNIGHT PERIOD. BETTER
CHANCES EXIST FOR TSRA TO DEVELOP LATE TONIGHT WITH MODELS SHOWING
KMHK SEEING THE HIGHER CHANCES AFT 08Z. CONFIDENCE IN TIME IS
MARGINAL THIS FAR OUT WITH ONLY A VCTS MENTION AT KMHK. VERY LOW
PROBABILITY AND NO MENTION OF TSRA AT KTOP/KFOE ATTM BUT WILL
REVISIT AT NEXT ISSUANCE. SOUTHEAST WINDS AOB 10 KTS THIS
AFTERNOON ARE EXPECTED TO BACK TOWARDS THE EAST AND WANE BLO 10
KTS OVERNIGHT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...BOWEN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1102 AM EDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 1102 AM EDT SAT JUL 13 2013
FRESHENED UP THE GRIDS ACCORDING TO THE LATEST RADAR AND OBSERVATION
TRENDS. CONVECTION IS TRYING TO WIND DOWN...ALTHOUGH A FEW CLUSTERS
REMAIN ACROSS PORTIONS OF THE AREA. STILL EXPECT A GENERAL DOWNWARD
TREND IN THE AREAL COVERAGE THROUGH THE AFTERNOON AS THE UPPER LEVEL LOW
GRADUALLY EXITS WEST AND HEIGHTS RECOVER.
UPDATE ISSUED AT 835 AM EDT SAT JUL 13 2013
CONVECTION CONTINUES TO BLOSSOM AROUND A VORT LOBE ROTATING AROUND
THE UPPER LEVEL LOW...WHICH IS STARTING TO MAKE ITS WESTWARD MOVEMENT
NOW. HAVE UPDATED FOR AN INCREASE IN POPS BASED ON THE LATEST RADAR
TRENDS. CONVECTIVE COVERAGE SHOULD DECREASE THIS AFTERNOON AS THE
UPPER LOW PULLS WEST AND HEIGHTS RECOVER.
UPDATE ISSUED AT 625 AM EDT SAT JUL 13 2013
SOME ELEVATED CONVECTION HAS FIRED UP ACROSS PORTIONS OF THE AREA FOR
THE PAST HOUR ASSOCIATED WITH SOME MOISTURE CONVERGENCE INDUCED BY
THE UPPER LEVEL LOW. LATEST HRRR MODEL AND NAM12 SUPPORT SCATTERED
ACTIVITY THROUGH THE MORNING. WILL INCLUDE CHANCE POPS THROUGH THE
MID-MORNING HOURS BASED ON THE LATEST RADAR TRENDS AND MODEL
GUIDANCE...BEFORE BLENDING IN WITH THE EXISTING FORECAST FOR THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 352 AM EDT SAT JUL 13 2013
AN AREA OF SURFACE HIGH PRESSURE REMAINS ANCHORED FROM NEW ENGLAND
THROUGH THE GREAT LAKES. THIS HAS PROVIDED A NICE REPRIEVE FROM THE
HUMIDITY ACROSS EASTERN KENTUCKY AS TEMPERATURES HAVE SLIPPED INTO
THE UPPER 50S AND LOWER 60S. MEANWHILE...AN UPPER LEVEL LOW IS
CURRENTLY SPINNING ITS WHEELS ACROSS NORTHEASTERN KENTUCKY...MAINLY
SPREADING SOME AREAS OF MID AND HIGH LEVEL CLOUD COVER ACROSS THE
AREA.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...GRADUALLY
SHIFTING THE UPPER LEVEL LOW WESTWARD...WHILE AN UPPER LEVEL HIGH
PRESSURE RIDGE RAMPS UP ACROSS NEW ENGLAND AND EVENTUALLY INTO THE
OHIO VALLEY. AS THE UPPER LOW SHIFTS WEST TODAY...ISOLATED TO
SCATTERED CONVECTION WILL BE POSSIBLE ACROSS THE AREA...WITH MOST
MODELS SHOWING SLIGHTLY BETTER COVERAGE IN THE WESTERN HALF OF THE
AREA. WHILE LAPSE RATES WILL NOT BE AS STEEP COMPARED TO
YESTERDAY...LINGERING MID-LEVEL DRY AIR WILL ALLOW FOR THE POTENTIAL
FOR A FEW STRONG STORMS. HIGHS TODAY WILL REACH INTO THE MID
80S...WITH DEW POINTS UP A FEW MORE DEGREES AS WELL.
CONVECTION WILL DIE OFF QUICKLY EARLY THIS EVENING...BETWEEN THE LOSS
OF HEATING AND HEIGHTS REBOUNDING AS THE UPPER LOW PULLS AWAY. LOWS
WILL GET DOWN INTO THE LOW TO MID 60S...WITH SOME PATCHY FOG ALONG
THE RIVER VALLEYS. ON SUNDAY...HIGHS WILL RETURN TO THE UPPER 80S FOR
MOST LOCATIONS...WITH THE THREAT OF AT LEAST SOME ISOLATED
CONVECTION ONCE AGAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM EDT SAT JUL 13 2013
THE MODELS...PARTICULARLY GFS AND ECMWF...ARE IN REALLY GOOD
AGREEMENT ALOFT THROUGH THE EXTENDED AS THEY CONTINUE TO MOVE THE
UPPER LOW...VISITING US THIS WEEKEND...WEST THROUGH THE SOUTHERN
PLAINS TO START THE UPCOMING WORK WEEK. THIS AMPLIFIED FEATURE IS
REPLACED OVER THE AREA BY A...MORE TYPICAL FOR THIS TIME OF
YEAR...RIDGE. THIS RIDGE WILL BE LIKEWISE AMPLIFIED AS IT SETTLES
OVER THE REGION MONDAY AND TUESDAY. THE MODELS ALL AGREE THAT IT
WILL SLOWLY WEAKEN WITH TIME THROUGH THE BREADTH OF THE WEEK...BUT
GENERALLY REMAIN CENTERED OVER THE OHIO VALLEY AS IT DOES SO.
GRADUALLY...THE WESTERLIES WILL START TO PRESS DOWN FROM THE NORTH
AND SHIFT THE RIDGE SOUTHWARD IN TIME TOWARD THE UPCOMING
WEEKEND. AS IT DOES SO... THERE WILL BE THE POTENTIAL FOR SOME MID
LEVEL ENERGY BRUSHING BY THE CWA FRIDAY...BUT...ALBEIT IN
CONJUNCTION WITH SMALL HEIGHT FALLS...NONE OF THE WAVES APPEAR TO BE
THAT SUBSTANTIAL IN THE MODELS THAT FAR OUT.
THE EXTENDED FORECAST WILL FEATURE A SEASONABLY WARM AND FAIRLY
TYPICAL WEEK OF MID SUMMER WEATHER. AS THE RIDGE ALOFT FADES WITH
TIME SO WILL THE SFC HIGH. WHEN THIS TAKES PLACE...FROM MID WEEK
ON...EXPECT LESS IN THE WAY OF SUPPRESSION OF CONVECTION SO THAT
POPS WILL BE A BIT HIGHER ON THURSDAY AND FRIDAY WHEN COMPARED TO
THE MINIMAL THREAT ON MONDAY AND TUESDAY. IN GENERAL...THE POPS EACH
DAY WILL MAX OUT DURING THE LATE AFTERNOON HOURS BEFORE FADING
DURING THE EVENING. HOWEVER...WITH LITTLE IN THE WAY OF TRIGGERS AND
THE RIDGES IN PLACE WILL GO NO HIGHER THAN SCATTERED SHOWERS AND
THUNDERSTORMS...EVEN LATE IN THE WEEK. ALSO...ANTICIPATE A BIT
HIGHER POPS OVER THE HIGHER TERRAIN OF FAR SOUTHEAST KENTUCKY
DAILY...WHEN COMPARED TO THE REST OF THE AREA. FINALLY...THE WARM
TEMPERATURES ON TAP WILL FEEL EVEN MORE UNCOMFORTABLE DURING THIS
UPCOMING WEEK AS THE HUMIDITY CREATES HEAT INDICES IN THE LOWER TO
MIDDLE 90S FOR A TIME EACH AFTERNOON.
THE CR GRID LOAD CAME IN DECENT OVERALL...THOUGH DID ADJUST POPS
DOWN A BIT DURING PEAK HEATING FOR THE LATTER PART OF THE EXTENDED.
ALSO...ADJUSTED OVERNIGHT LOWS EACH NIGHT TO ACCOUNT FOR ANTICIPATED
RIDGE TO VALLEY TEMPERATURE DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 835 AM EDT SAT JUL 13 2013
AN EXITING UPPER LEVEL LOW PRESSURE SYSTEM HAS ALLOWED FOR SCATTERED
TO NUMEROUS CONVECTION THIS MORNING. EXPECT THE BEST COVERAGE TO MOVE
OUT THROUGH 16Z...WITH MAINLY ISOLATED COVERAGE EXPECTED THEREAFTER.
IFR OR WORSE CONDITIONS CAN BE EXPECTED IN ANY PASSING THUNDERSTORMS.
ALL CONVECTION WILL DISSIPATE THIS EVENING...WITH PATCHY VALLEY FOG
LIKELY FORMING ONCE AGAIN BETWEEN 06 AND 12Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...GREIF
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
835 AM EDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 835 AM EDT SAT JUL 13 2013
CONVECTION CONTINUES TO BLOSSOM AROUND A VORT LOBE ROTATING AROUND
THE UPPER LEVEL LOW...WHICH IS STARTING TO MAKE ITS WESTWARD MOVEMENT
NOW. HAVE UPDATED FOR AN INCREASE IN POPS BASED ON THE LATEST RADAR
TRENDS. CONVECTIVE COVERAGE SHOULD DECREASE THIS AFTERNOON AS THE
UPPER LOW PULLS WEST AND HEIGHTS RECOVER.
UPDATE ISSUED AT 625 AM EDT SAT JUL 13 2013
SOME ELEVATED CONVECTION HAS FIRED UP ACROSS PORTIONS OF THE AREA FOR
THE PAST HOUR ASSOCIATED WITH SOME MOISTURE CONVERGENCE INDUCED BY
THE UPPER LEVEL LOW. LATEST HRRR MODEL AND NAM12 SUPPORT SCATTERED
ACTIVITY THROUGH THE MORNING. WILL INCLUDE CHANCE POPS THROUGH THE
MID-MORNING HOURS BASED ON THE LATEST RADAR TRENDS AND MODEL
GUIDANCE...BEFORE BLENDING IN WITH THE EXISTING FORECAST FOR THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 352 AM EDT SAT JUL 13 2013
AN AREA OF SURFACE HIGH PRESSURE REMAINS ANCHORED FROM NEW ENGLAND
THROUGH THE GREAT LAKES. THIS HAS PROVIDED A NICE REPRIEVE FROM THE
HUMIDITY ACROSS EASTERN KENTUCKY AS TEMPERATURES HAVE SLIPPED INTO
THE UPPER 50S AND LOWER 60S. MEANWHILE...AN UPPER LEVEL LOW IS
CURRENTLY SPINNING ITS WHEELS ACROSS NORTHEASTERN KENTUCKY...MAINLY
SPREADING SOME AREAS OF MID AND HIGH LEVEL CLOUD COVER ACROSS THE
AREA.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...GRADUALLY
SHIFTING THE UPPER LEVEL LOW WESTWARD...WHILE AN UPPER LEVEL HIGH
PRESSURE RIDGE RAMPS UP ACROSS NEW ENGLAND AND EVENTUALLY INTO THE
OHIO VALLEY. AS THE UPPER LOW SHIFTS WEST TODAY...ISOLATED TO
SCATTERED CONVECTION WILL BE POSSIBLE ACROSS THE AREA...WITH MOST
MODELS SHOWING SLIGHTLY BETTER COVERAGE IN THE WESTERN HALF OF THE
AREA. WHILE LAPSE RATES WILL NOT BE AS STEEP COMPARED TO
YESTERDAY...LINGERING MID-LEVEL DRY AIR WILL ALLOW FOR THE POTENTIAL
FOR A FEW STRONG STORMS. HIGHS TODAY WILL REACH INTO THE MID
80S...WITH DEW POINTS UP A FEW MORE DEGREES AS WELL.
CONVECTION WILL DIE OFF QUICKLY EARLY THIS EVENING...BETWEEN THE LOSS
OF HEATING AND HEIGHTS REBOUNDING AS THE UPPER LOW PULLS AWAY. LOWS
WILL GET DOWN INTO THE LOW TO MID 60S...WITH SOME PATCHY FOG ALONG
THE RIVER VALLEYS. ON SUNDAY...HIGHS WILL RETURN TO THE UPPER 80S FOR
MOST LOCATIONS...WITH THE THREAT OF AT LEAST SOME ISOLATED
CONVECTION ONCE AGAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM EDT SAT JUL 13 2013
THE MODELS...PARTICULARLY GFS AND ECMWF...ARE IN REALLY GOOD
AGREEMENT ALOFT THROUGH THE EXTENDED AS THEY CONTINUE TO MOVE THE
UPPER LOW...VISITING US THIS WEEKEND...WEST THROUGH THE SOUTHERN
PLAINS TO START THE UPCOMING WORK WEEK. THIS AMPLIFIED FEATURE IS
REPLACED OVER THE AREA BY A...MORE TYPICAL FOR THIS TIME OF
YEAR...RIDGE. THIS RIDGE WILL BE LIKEWISE AMPLIFIED AS IT SETTLES
OVER THE REGION MONDAY AND TUESDAY. THE MODELS ALL AGREE THAT IT
WILL SLOWLY WEAKEN WITH TIME THROUGH THE BREADTH OF THE WEEK...BUT
GENERALLY REMAIN CENTERED OVER THE OHIO VALLEY AS IT DOES SO.
GRADUALLY...THE WESTERLIES WILL START TO PRESS DOWN FROM THE NORTH
AND SHIFT THE RIDGE SOUTHWARD IN TIME TOWARD THE UPCOMING
WEEKEND. AS IT DOES SO... THERE WILL BE THE POTENTIAL FOR SOME MID
LEVEL ENERGY BRUSHING BY THE CWA FRIDAY...BUT...ALBEIT IN
CONJUNCTION WITH SMALL HEIGHT FALLS...NONE OF THE WAVES APPEAR TO BE
THAT SUBSTANTIAL IN THE MODELS THAT FAR OUT.
THE EXTENDED FORECAST WILL FEATURE A SEASONABLY WARM AND FAIRLY
TYPICAL WEEK OF MID SUMMER WEATHER. AS THE RIDGE ALOFT FADES WITH
TIME SO WILL THE SFC HIGH. WHEN THIS TAKES PLACE...FROM MID WEEK
ON...EXPECT LESS IN THE WAY OF SUPPRESSION OF CONVECTION SO THAT
POPS WILL BE A BIT HIGHER ON THURSDAY AND FRIDAY WHEN COMPARED TO
THE MINIMAL THREAT ON MONDAY AND TUESDAY. IN GENERAL...THE POPS EACH
DAY WILL MAX OUT DURING THE LATE AFTERNOON HOURS BEFORE FADING
DURING THE EVENING. HOWEVER...WITH LITTLE IN THE WAY OF TRIGGERS AND
THE RIDGES IN PLACE WILL GO NO HIGHER THAN SCATTERED SHOWERS AND
THUNDERSTORMS...EVEN LATE IN THE WEEK. ALSO...ANTICIPATE A BIT
HIGHER POPS OVER THE HIGHER TERRAIN OF FAR SOUTHEAST KENTUCKY
DAILY...WHEN COMPARED TO THE REST OF THE AREA. FINALLY...THE WARM
TEMPERATURES ON TAP WILL FEEL EVEN MORE UNCOMFORTABLE DURING THIS
UPCOMING WEEK AS THE HUMIDITY CREATES HEAT INDICES IN THE LOWER TO
MIDDLE 90S FOR A TIME EACH AFTERNOON.
THE CR GRID LOAD CAME IN DECENT OVERALL...THOUGH DID ADJUST POPS
DOWN A BIT DURING PEAK HEATING FOR THE LATTER PART OF THE EXTENDED.
ALSO...ADJUSTED OVERNIGHT LOWS EACH NIGHT TO ACCOUNT FOR ANTICIPATED
RIDGE TO VALLEY TEMPERATURE DIFFERENCES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 835 AM EDT SAT JUL 13 2013
AN EXITING UPPER LEVEL LOW PRESSURE SYSTEM HAS ALLOWED FOR SCATTERED
TO NUMEROUS CONVECTION THIS MORNING. EXPECT THE BEST COVERAGE TO MOVE
OUT THROUGH 16Z...WITH MAINLY ISOLATED COVERAGE EXPECTED THEREAFTER.
IFR OR WORSE CONDITIONS CAN BE EXPECTED IN ANY PASSING THUNDERSTORMS.
ALL CONVECTION WILL DISSIPATE THIS EVENING...WITH PATCHY VALLEY FOG
LIKELY FORMING ONCE AGAIN BETWEEN 06 AND 12Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...GREIF
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
625 AM EDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 625 AM EDT SAT JUL 13 2013
SOME ELEVATED CONVECTION HAS FIRED UP ACROSS PORTIONS OF THE AREA FOR
THE PAST HOUR ASSOCIATED WITH SOME MOISTURE CONVERGENCE INDUCED BY
THE UPPER LEVEL LOW. LATEST HRRR MODEL AND NAM12 SUPPORT SCATTERED
ACTIVITY THROUGH THE MORNING. WILL INCLUDE CHANCE POPS THROUGH THE
MID-MORNING HOURS BASED ON THE LATEST RADAR TRENDS AND MODEL
GUIDANCE...BEFORE BLENDING IN WITH THE EXISTING FORECAST FOR THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 352 AM EDT SAT JUL 13 2013
AN AREA OF SURFACE HIGH PRESSURE REMAINS ANCHORED FROM NEW ENGLAND
THROUGH THE GREAT LAKES. THIS HAS PROVIDED A NICE REPRIEVE FROM THE
HUMIDITY ACROSS EASTERN KENTUCKY AS TEMPERATURES HAVE SLIPPED INTO
THE UPPER 50S AND LOWER 60S. MEANWHILE...AN UPPER LEVEL LOW IS
CURRENTLY SPINNING ITS WHEELS ACROSS NORTHEASTERN KENTUCKY...MAINLY
SPREADING SOME AREAS OF MID AND HIGH LEVEL CLOUD COVER ACROSS THE
AREA.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...GRADUALLY
SHIFTING THE UPPER LEVEL LOW WESTWARD...WHILE AN UPPER LEVEL HIGH
PRESSURE RIDGE RAMPS UP ACROSS NEW ENGLAND AND EVENTUALLY INTO THE
OHIO VALLEY. AS THE UPPER LOW SHIFTS WEST TODAY...ISOLATED TO
SCATTERED CONVECTION WILL BE POSSIBLE ACROSS THE AREA...WITH MOST
MODELS SHOWING SLIGHTLY BETTER COVERAGE IN THE WESTERN HALF OF THE
AREA. WHILE LAPSE RATES WILL NOT BE AS STEEP COMPARED TO
YESTERDAY...LINGERING MID-LEVEL DRY AIR WILL ALLOW FOR THE POTENTIAL
FOR A FEW STRONG STORMS. HIGHS TODAY WILL REACH INTO THE MID
80S...WITH DEW POINTS UP A FEW MORE DEGREES AS WELL.
CONVECTION WILL DIE OFF QUICKLY EARLY THIS EVENING...BETWEEN THE LOSS
OF HEATING AND HEIGHTS REBOUNDING AS THE UPPER LOW PULLS AWAY. LOWS
WILL GET DOWN INTO THE LOW TO MID 60S...WITH SOME PATCHY FOG ALONG
THE RIVER VALLEYS. ON SUNDAY...HIGHS WILL RETURN TO THE UPPER 80S FOR
MOST LOCATIONS...WITH THE THREAT OF AT LEAST SOME ISOLATED
CONVECTION ONCE AGAIN.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 315 AM EDT SAT JUL 13 2013
THE MODELS...PARTICULARLY GFS AND ECMWF...ARE IN REALLY GOOD
AGREEMENT ALOFT THROUGH THE EXTENDED AS THEY CONTINUE TO MOVE THE
UPPER LOW...VISITING US THIS WEEKEND...WEST THROUGH THE SOUTHERN
PLAINS TO START THE UPCOMING WORK WEEK. THIS AMPLIFIED FEATURE IS
REPLACED OVER THE AREA BY A...MORE TYPICAL FOR THIS TIME OF
YEAR...RIDGE. THIS RIDGE WILL BE LIKEWISE AMPLIFIED AS IT SETTLES
OVER THE REGION MONDAY AND TUESDAY. THE MODELS ALL AGREE THAT IT
WILL SLOWLY WEAKEN WITH TIME THROUGH THE BREADTH OF THE WEEK...BUT
GENERALLY REMAIN CENTERED OVER THE OHIO VALLEY AS IT DOES SO.
GRADUALLY...THE WESTERLIES WILL START TO PRESS DOWN FROM THE NORTH
AND SHIFT THE RIDGE SOUTHWARD IN TIME TOWARD THE UPCOMING
WEEKEND. AS IT DOES SO... THERE WILL BE THE POTENTIAL FOR SOME MID
LEVEL ENERGY BRUSHING BY THE CWA FRIDAY...BUT...ALBEIT IN
CONJUNCTION WITH SMALL HEIGHT FALLS...NONE OF THE WAVES APPEAR TO BE
THAT SUBSTANTIAL IN THE MODELS THAT FAR OUT.
THE EXTENDED FORECAST WILL FEATURE A SEASONABLY WARM AND FAIRLY
TYPICAL WEEK OF MID SUMMER WEATHER. AS THE RIDGE ALOFT FADES WITH
TIME SO WILL THE SFC HIGH. WHEN THIS TAKES PLACE...FROM MID WEEK
ON...EXPECT LESS IN THE WAY OF SUPPRESSION OF CONVECTION SO THAT
POPS WILL BE A BIT HIGHER ON THURSDAY AND FRIDAY WHEN COMPARED TO
THE MINIMAL THREAT ON MONDAY AND TUESDAY. IN GENERAL...THE POPS EACH
DAY WILL MAX OUT DURING THE LATE AFTERNOON HOURS BEFORE FADING
DURING THE EVENING. HOWEVER...WITH LITTLE IN THE WAY OF TRIGGERS AND
THE RIDGES IN PLACE WILL GO NO HIGHER THAN SCATTERED SHOWERS AND
THUNDERSTORMS...EVEN LATE IN THE WEEK. ALSO...ANTICIPATE A BIT
HIGHER POPS OVER THE HIGHER TERRAIN OF FAR SOUTHEAST KENTUCKY
DAILY...WHEN COMPARED TO THE REST OF THE AREA. FINALLY...THE WARM
TEMPERATURES ON TAP WILL FEEL EVEN MORE UNCOMFORTABLE DURING THIS
UPCOMING WEEK AS THE HUMIDITY CREATES HEAT INDICES IN THE LOWER TO
MIDDLE 90S FOR A TIME EACH AFTERNOON.
THE CR GRID LOAD CAME IN DECENT OVERALL...THOUGH DID ADJUST POPS
DOWN A BIT DURING PEAK HEATING FOR THE LATTER PART OF THE EXTENDED.
ALSO...ADJUSTED OVERNIGHT LOWS EACH NIGHT TO ACCOUNT FOR ANTICIPATED
RIDGE TO VALLEY TEMPERATURE DIFFERENCES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 150 AM EDT SAT JUL 13 2013
EXPECT MAINLY VFR CONDITIONS THROUGH THE PERIOD WITH THE EXCEPTION OF
SOME IFR OR WORSE FOG ALONG THE DEEPER RIVER VALLEYS THROUGH 12Z.
A PASSING UPPER LEVEL LOW PRESSURE SYSTEM...CURRENTLY SPIRALING
ACROSS EASTERN KENTUCKY WILL GRADUALLY DRIFT WEST THROUGH SATURDAY.
THIS MAY KICK OFF A FEW SHOWERS AND THUNDERSTORMS ACROSS THE
AREA...HOWEVER CONFIDENCE IN TIMING AND AREAL COVERAGE REMAINS TOO
LOW TO INCLUDE ANY MENTION IN THE TAFS FOR NOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...GREIF
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS DULUTH MN
1054 AM CDT SAT JUL 13 2013
.UPDATE...
FORECAST UPDATE TO REFRESH MORNING WORDING AND INCREASE RAINFALL
AMOUNTS SIGNIFICANTLY OVERNIGHT/SUNDAY...MAINLY FROM THE BRAINERD
LAKES AREA...THROUGH THE IRON RANGE AND ACROSS THE MINNESOTA
ARROWHEAD. LATEST NAM BUFR SOUNDINGS AT KBRD-KELO SUGGEST A
CORRIDOR OF NEAR RECORD PWATS...IN EXCESS OF 2 INCHES...BECOMES
CO-LOCATED WITH THE STATIONARY BOUNDARY TONIGHT AND SUNDAY. IF
THERE IS ENOUGH FORCING/INSTABILITY FOR CONVECTION ALONG THIS
FRONT...PERIODS OF HEAVY RAINFALL WILL BE POSSIBLE. DIFFICULTY
REMAINS IN THE EXACT PLACEMENT OF THE FRONT OVER THE NEXT 24-36
HOURS. THE 15Z RUC MESO ANALYSIS SHOWS A WELL DEFINED H85 BOUNDARY
CURRENTLY EXTENDS WEST TO EAST ACROSS THE NORTHLAND...GENERALLY
FROM CASS COUNTY...TO THE TWIN PORTS...AND EAST OVER LAKE
SUPERIOR. LOCATIONS ALONG AND NORTH OF THIS BOUNDARY AREA
EXPECTED TO SEE THE BEST CHANCE FOR THUNDERSTORM REDEVELOPMENT
THIS AFTERNOON....CONTINUING OVERNIGHT. LIMITING FACTOR TO STORMS
AND HEAVY RAIN WILL THE STRENGTH OF THE A MID LEVEL CAP. LATEST
NAM12 SUGGESTS WIDESPREAD H70 TEMPS IN THE 9-10 C RANGE ENCOMPASS
THE REGION TONIGHT THROUGH SUNDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 659 AM CDT SAT JUL 13 2013/
AVIATION...12Z TAF ISSUANCE...
LARGE AREA OF RAIN/STORMS HAS WEAKENED OVER NWRN WISC EARLY THIS
MORNING. IN ITS WAKE...AN AREA OF MVFR CEILINGS HAVE DEVELOPED
NEAR KDLH/KHIB ALONG WITH LOCAL BR AT KINL. TOUGH FCST TRYING TO
TIME/PLACE THE REDEVELOPING STORMS TODAY. ALTHOUGH STORMS MAY
DEVELOP ALMOST ANYWHERE DUE TO THE VERY HIGH MOISTURE CONTENT IN
THE ATMOSPHERE...THE GENERAL IDEA IS THAT THE HIGHEST PROBABILITY WILL
BE OVER WISC THIS MORNING...AND THEN SHIFTING TOWARDS KBRD/KDLH
THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 410 AM CDT SAT JUL 13 2013/
SHORT TERM...TODAY AND TONIGHT...
AN ACTIVE MORNING ACROSS THE NORTHLAND THIS MORNING...WITH
THUNDERSTORMS MOVING FROM THE EASTERN PORTIONS OF THE MINNESOTA CWA
ACROSS LAKE SUPERIOR AND INTO NORTHWEST WISCONSIN. SO FAR HAVE ONLY
HAD REPORTS OF HEAVY RAIN AND FREQUENT LIGHTNING. NOT TOO
SURPRISING GIVEN THAT MU CAPE VALUES ARE 500-1000J/KG AND VERY
LITTLE SHEAR OR OTHER FACTORS THAT MAKE NOCTURNAL STORMS REALLY GET
VIGOROUS. THESE STORMS FORMED OVER EASTERN NORTH DAKOTA THIS
AFTERNOON ALONG THE TROUGH AXIS EXTENDING NORTH FROM A SURFACE LOW
OVER CENTRAL SOUTH DAKOTA. WITH THE UNSTABLE AIR AND WEAKLY CAPPED
AIRMASS TO THE EAST THE STORMS HAVE JUST KEPT MOVING ON EAST.
EXPECT THEM TO CONTINUE TO GRADUALLY DIMINISH...AND EXPECT THE
GREATEST DIMINISHMENT TREND AFTER SUNRISE THIS MORNING. THUS...HAVE
LIMITED THE MID TO LATE MORNING HOURS TO JUST CHANCE POPS...THOUGH
THE EARLY MORNING HOURS ARE MUCH HIGHER. THIS AFTERNOON THE
THUNDERSTORM ACTIVITY LOCATION IS A LITTLE HARDER TO PIN DOWN...AND
MUCH IS GOING TO DEPEND ON WHERE THE ATMOSPHERE FORMS A BOUNDARY
BEHIND THIS MORNING CONVECTION...AND WHERE IT SHIFTS TO DURING THE
AFTERNOON WITH THE STRONG WARM AIR ADVECTION REGIME ONGOING AND THE
INVERTED TROUGH AXIS AND SURFACE LOW ONLY MARGINALLY FARTHER EAST
THAN THEY WERE FRIDAY AFTERNOON. FOR NOW AM FAVORING A SLIGHTLY
FARTHER NORTH INITIATION...ALONG THE LINES OF MORE OF THE SHORT
RANGE MODELS...GENERALLY EXTENDING FROM THE PEQUOT LAKES AND LEECH
LAKE AREAS...NORTHEAST UP INTO THE ARROWHEAD. THE AFTERNOON AND
EVENING ACTIVITY IS GOING TO BE MORE SCATTERED IN NATURE...WITHOUT A
SINGLE STRONG TRIGGER TO ACT UPON. BY LATER IN THE EVENING AND
OVERNIGHT THOUGH...THE LOW LEVEL JET KICKS IN...AND EXPECT FAR MORE
DEVELOPMENT ALONG AND NORTH OF THE SAME AXIS...AND HAVE RAISED POPS
FOR THE OVERNIGHT HOURS. AS FOR TEMPERATURES...INCREASED CLOUDS ARE
GOING TO TEND TO KEEP THEM COOLER...BUT THE STRONG WARM AIR
ADVECTION HAS BROUGHT IN A VERY WARM AIRMASS AND WE WILL BE STARTING
OUT MUCH WARMER THAN YESTERDAY. SO...HAVE TEMPERATURES COOLER THAN
YESTERDAY BUT NOT BY A LARGE AMOUNT. THE INCREASED LOW LEVEL
MOISTURE IS GOING TO KEEP CONDITIONS VERY MUGGY. TONIGHT HAVE
CONTINUED THE WARM TEMPS WITH MINS IN THE MID 60S AGAIN.
EXTENDED...SUNDAY THROUGH FRIDAY...
A RETROGRADING AND EXPANDING MID LVL HIGH WILL PUSH WEST FROM THE
ERN CONUS INTO THE OHIO VALLEY OVER THE NEXT 5 DAYS. THIS WILL KEEP
THE MAIN JET AXIS NORTH OF THE CWA UNTIL AT LEAST MIDWEEK. THE
RESULT SHOULD BE A CONTINUATION OF A WARM AND HUMID WEATHER PATTERN.
A TREND FOR THE AREA OF SCTD CONVECTION TO LIFT NORTH MONDAY AND
TUESDAY. THIS APPEARS REASONABLE GIVEN THE CLOSER PROXIMITY TO THE
FRONTAL BDRY CONVERGENCE AND UPPER JET AXIS. A CANADIAN COLD FRONT
WILL PUSH SOUTH ACROSS THE REGION LATE WEDNESDAY. THIS SHOULD USHER
IN A DRIER AIR MASS WITH LOWER DEWPOINTS AND NWRLY WINDS. THIS MAY
BE SHORT LIVED AS MDLS SUGGEST FRONTAL BDRY MAY ATTEMPT TO MOVE
NORTHWARD THURSDAY. GFS/EC/GEM AT ODDS WITH EACH OTHER WITH EC MUCH
MORE AGGRESSIVE ON DRY PUSH SOUTH WHILE GFS/GEM KEEP CHANCES OF
RW/TRW THROUGH THE PERIOD. ALLBLEND SOLUTION KEEPS PRECIP IN FCST
THROUGH WEEK. GIVEN THE POTENTIAL CHANGES ALOFT WITH AMPLIFYING MID
LVL TROF LATE IN THE WEEK....CONFIDENCE IN FCST WED-FRI NOT VERY
HIGH.
AVIATION.../06Z TAF ISSUANCE/
A COLD FRONT WILL CONTINUE TO MOVE TO THE EAST AND SOUTHEAST ACROSS
THE NORTHLAND OVERNIGHT. THE FRONT WILL BE THE FOCUS FOR SHOWERS AND
THUNDERSTORMS ACROSS THE REGION OVERNIGHT AND INTO SATURDAY.
CONDITIONS WILL BE LARGELY VFR...BUT SOME MVFR CIGS/VSBYS WILL BE
FOUND IN THE VICINITY OF THE FRONT AND WITH THE SHOWERS AND STORMS.
THE THREAT OF SHOWERS AND STORMS WILL LINGER FOR MOST AREAS
THROUGHOUT THE TAF PERIOD.
&&
.POINT TEMPS/POPS...
DLH 80 64 80 63 / 40 70 50 40
INL 82 68 79 62 / 30 40 40 50
BRD 85 68 81 66 / 50 80 60 30
HYR 81 65 86 65 / 20 20 10 10
ASX 81 64 83 62 / 30 50 30 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
LONG TERM....STEWART
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
620 AM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT SAT JUL 13 2013
AREA OF CONVECTION CONTINUES TO TRACK EAST AROUND 24 KNOTS. THE
UPPER TROUGH ASSOCIATED APPEARS TO BE WEAKENING A BIT AS IT RIDES
INTO THE RIDGE OVER THE GREAT LAKES REGION. RADAR ACTIVITY HAS
SLOWED A BIT IN THE LATEST HOUR...AND IS REGENERATING TO THE
WEST...PROBABLY AN INDICATION OF THE WAVE SLOWING AND MOVING INTO
THE RIDGE SITUATED TO THE EAST. LATEST SPC MESOSCALE ANALYSIS SHOWS
ACTIVITY ELEVATED WITH ACTIVITY DRIVEN BY WAA PATTERN WITH THE UPPER
TROUGH. DECENT MOISTURE TRANSPORT ASSOCIATED AS WELL...WITH BRIEF
DOWNPOURS WITH THE ACTIVITY. QUESTION REMAINS HOW FAR EAST THIS
WILL GO THIS MORNING BEFORE DISSIPATING. THE LATEST HRRR TRENDS
INDICATE THIS AREA WILL WORK EAST INTO WEST CENTRAL WI.
ALSO...SECONDARY AREA OF 850MB WAA REGENERATING TO THE
SOUTHWEST...INTO SOUTHEAST SOUTH DAKOTA. THIS IS AN EXTENSION TO
THE LOW LEVEL JET AND MAY BE ASSOCIATED WITH SOUTHERN SODAK WAVE
LIFTING NORTHEAST AND MOVING INTO WEST CENTRAL MN THIS
AFTERNOON...PER LATEST DETERMINISTIC MODEL TRENDS.
WILL HOLD ONTO CHANCE BUT DECREASE TO SLIGHT CHANCE THROUGH
18Z...THEN INCREASE POPS AGAIN TO THE NORTHWEST TO CHANCE AFTER
21Z...NEAREST TO THE AREA OF THE SURFACE FRONT. DESTABILIZATION WILL
OCCUR...WITH AMOUNT OF HEATING DETERMINED ON HOW MUCH SUNSHINE WILL
DEVELOP. SHOULD SEE AT LEAST SOME AS THESE SYSTEMS WANE THIS
MORNING. BEST INSTABILITY RIDES TO THE NORTHWEST BY LATE AFTERNOON
WITH SOME POSSIBILITY OF STRONG WINDS AND HEAVY RAIN INTO THE EVENING
PER LATEST SPC DAY ONE OUTLOOK.
WILL MENTION LIKELY POPS TO THE NORTHWEST AND DRIVE CHANCE POPS DOWN
A BIT FARTHER TO THE SOUTHEAST AGAIN TONIGHT...JUST IN CASE ACTIVITY
IS MORE ROBUST THAN MODELS INDICATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 309 AM CDT SAT JUL 13 2013
STRONG MID LEVEL RIDGING WILL BEGIN BUILDING WESTWARD ACROSS THE
OHIO VALLEY AND SOUTHERN GREAT LAKES SUNDAY MORNING WITH 500 MB
HEIGHTS OF NEARLY 600 DAM CENTERED OVER NERN OHIO BY AFTERNOON.
MUCH DRIER AIR WILL ACCOMPANY THIS RIDGING SO EXPECTING A SHARP
DROP OFF IN PRECIPITABLE WATER FROM EAST TO WEST DURING THE DAY.
PW COULD RANGE FROM 0.75-1.0 INCH ACROSS SRN MN/WRN WI TO
2.0-2.25 INCHES ACROSS WRN MN. MAINTAINED VERY LOW POPS AND SUNNY
SKIES OVER THE SOUTH AND EAST AND MAINTAINED MEDIUM RANGE POPS
NORTHWEST. LOW MBE VELOCITIES...VERY DEEP WARM CLOUD DEPTH...AND
HIGH PW/S ALONG THE STATIONARY FRONT COULD LEAD TO LOCALLY HEAVY
RAIN AND FLOODING. BY SUNDAY NIGHT...THE DRIER AIR WILL CONTINUE
TO ADVANCE WESTWARD AND BRING DIMINISHING CHANCES OF RAIN ACROSS
WRN MN.
THE RIDGE WILL SLOWLY SETTLE OVER NORTHERN INDIANA THROUGH THE
MIDDLE OF NEXT WEEK. THERMAL PROFILES WILL INCH UP EACH DAY AND
925 MB TEMPS BY WEDNESDAY AND THURSDAY MAY TOP +27 OR +28C. HIGHS
IN THE LOW TO MID 90S ARE A GOOD BET...AND COULD BE EVEN WARMER. PW/S
WILL ALSO INCREASE BACK TO AROUND 1.75 INCHES AND SURFACE DEW
POINTS WILL HOVER ON EITHER SIDE OF 70F. HEAT INDICES MAY BECOME
AN ISSUE BY MIDWEEK WITH READINGS POTENTIALLY EXCEEDING 100F.
CANNOT RULE OUT HEAT HEADLINES IF THIS IS TO VERIFY...PARTICULARLY
WHEN LOWS FAIL TO DROP BELOW 75 IN THE METRO.
SOMETHING THAT MAY BRING RELIEF DURING THIS PERIOD ARE LOW
PROBABILITIES OF THUNDERSTORMS. DESPITE SUCH A POTENT RIDGE...THE
PROFILE IS LACKING OF ANY SIGNIFICANT INVERSION SO WE COULD SEE
POP UP STORMS WEDNESDAY AND THURSDAY.
BY FRIDAY...THE RIDGE WILL BEGIN TO BREAK DOWN AND A COLD FRONT
WILL SAG SOUTH THROUGH THE UPPER MIDWEST. LOWER HUMIDITY AND
TEMPERATURES CLOSER TO AVERAGE ARE ANTICIPATED BY THE END OF THE
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 611 AM CDT SAT JUL 13 2013
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO WEAKEN AS THEY TRACK EAST
THROUGH THE MORNING. SOME MVFR CIGS POSSIBLE OVER THE NORTH
EARLY...WITH SOME LOWER CIGS/VSBSY IN HEAVY RAIN TO THE SOUTHEAST.
SOME REDEVELOPMENT INTO THE AFTERNOON/EVENING POSSIBLE...MAINLY ON
THE NORTH SIDE OF THE AREA. WINDS FROM 150-180 DEGREES WILL
PREVAIL THROUGH THE PERIOD...WITH GUSTS OVER THE SOUTH. THUNDERSTORM
DEVELOPMENT WILL BE A GOOD BET AGAIN OVER WEST CENTRAL MN INTO
CENTRAL MN...AFFECTING KAXN/KSTC FOR THE MOST PART. CONFIDENCE IN
TIMING/LOCATION IS LOW...BUT DID MENTION TEMPOS AT THOSE TWO
LOCATIONS.
KMSP...
THUNDER/HEAVY RAIN EXITING THE AREA THROUGH 14Z. THEN EXPECT VFR
CONDITIONS THROUGH THE PERIOD. MAY BE A CHANCE OF SOME THUNDER
MOVING IN AGAIN MAINLY AFTER 08Z TONIGHT...BUT MOST ACTIVITY
SHOULD REMAIN TO THE NORTH AND WEST. WILL MENTION VCSH FOR NOW.
SOUTHERLY WINDS COULD BE A BIT GUSTY INTO THE AFTERNOON. THEN
BECOMING MORE SOUTHEAST INTO THE EVENING.
/OUTLOOK FOR KMSP/
SUN...VFR. WINDS S 10KT.
MON...VFR. WINDS S 5-10 KT.
TUE...VFR. WINDS SW 5-10 KT.
&&
$$
SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
949 AM CDT SAT JUL 13 2013
.UPDATE...
12Z SOUNDINGS AND BLENDED TPW PRODUCT SHOW THAT UNSEASONABLY DRY
AIRMASS HAS OVERSPREAD THE AREA...WITH PRECIPITABLE WATER VALUES OF
LESS THAN AN INCH NW OF A MONTPELIER TO MEADVILLE LINE. SHORT TERM
MODEL FORECASTS INDICATE THAT THIS INFLUX OF DRIER AIR IS LIKELY
PEAKING AT THIS TIME...WITH GRADUAL TAPPING OF MUCH GREATER MOISTURE
TO OUR SE STARTING THIS AFTERNOON. LATEST HRRR SUPPORTS THE IDEA OF
SOME ISOLATED TO WIDELY SCATTERED DIURNAL SHRA/TSRA DEVELOPING LATE
THIS AFTERNOON OVER THE I-59 CORRIDOR IN AREA OF WEAK MOISTURE
ADVECTION...SO CURRENT POPS LOOK GOOD.
TEMPS ARE CURRENTLY RUNNING A FEW DEGS ABOVE HOURLY READINGS OVER
WESTERN AREAS. SATELLITE SHOWS SOME MID/HIGH CLOUDS STREAMING IN FROM
THE N AS ASCENT ASSOCIATED WITH WWD MOVING UPPER LOW OVER KY CAUSES
SOME CLOUD DEVELOPMENT. GIVEN 310-320K ISENTROPIC SURFACE FORECASTS
OF RELATIVELY DRY MID/UPPER LEVELS AND ONLY WEAK ASCENT...DO NOT
EXPECT THIS CLOUD COVER TO GET OUT OF HAND. BUT WITH SOME CLOUDS AND
CONTINUED WEAK COOL AIR ADVECTION...WILL NOT RAISE MAX TEMPS FOR TODAY
AT THIS POINT IN SPITE OF CURRENT TRENDS. OVERALL FORECAST LOOKS TO
BE IN VERY GOOD SHAPE AND ONLY TWEAKS TO GRIDS WERE TO ACCOUNT FOR
SHORT TERM ADJUSTMENTS TO TEMPS/CLOUDS. /AEG/
&&
.PREV DISCUSSION... /ISSUED 410 AM CDT SAT JUL 13 2013/
SHORT TERM...TODAY THROUGH SUNDAY NIGHT...IT IS POSSIBLE THERE
COULD BE A BIT OF FOG AROUND HATTIESBURG THIS MORNING...BUT
OTHERWISE ANTICIPATE A NICE AND SUNNY START TO YOUR SATURDAY WITH
TEMPERATURES MORE THAN PLEASANT AT MOST LOCATIONS. MOSTLY SUNNY
SKIES WITH RELATIVELY LOW HUMIDITY SHOULD CONTINUE THROUGHOUT THE
DAY FOR MOST WITH TEMPERATURES PEAKING IN THE UPPER 80S TO AROUND
90. AN EXCEPTION TO THE ENTIRELY DRY CONDITIONS WILL LIKELY BE ALONG
THE I-59 CORRIDOR IN SE MS THIS AFTERNOON. HERE...A NEARBY HUNG-UP
FRONTAL BOUNDARY WILL BE ASSOCIATED WITH GREATER MOISTURE AND HENCE
SOME INSTABILITY DURING PEAK HEATING. A LITTLE UPPER LEVEL LIFT
BROUGHT BY RETROGRADING TROUGH AXIS TO OUR NORTH SHOULD HELP TO
TRIGGER AT LEAST ISOLATED SHOWERS AND STORMS IN THESE SOUTHEAST
AREAS BY LATE AFTERNOON.
THE PREVIOUSLY HUNG-UP FRONTAL BOUNDARY WILL START TO PIVOT AND HEAD
BACK INTO FAR EASTERN MS OVERNIGHT AS THE RETROGRADING TROUGH AXIS
ALOFT INSTIGATES INCREASING SOUTHEAST LOW LEVEL FLOW OFF THE GULF.
AIDING MOISTURE ADVECTION WILL BE ENHANCED FLOW AROUND A WEAK LOW
LEVEL CIRCULATION CURRENTLY IN THE NORTHEASTERN GULF OF MEXICO. ALL
THIS COULD LEAD TO AT LEAST ISOLATED SHOWER POSSIBILITIES THROUGH
THE NIGHT IN EASTERN THIRD OF MISSISSIPPI...WHILE AREAS FURTHER WEST
ENJOY MOSTLY CLEAR TO PARTLY CLOUDY SKIES AND TEMPERATURES A TAD
BELOW AVERAGE.
ON SUNDAY THE SOUTHEASTERLY LOW LEVEL FLOW WILL COME STREAMING BACK
THROUGH THE REGION AS THE PREVIOUSLY HUNG-UP BOUNDARY KEEPING GULF
MOISTURE AT BAY RELENTS. MOISTURE TRANSPORT AND ADVECTION SHOULD BE
GREATEST ACROSS THE NORTHEASTERN HALF OF THE FORECAST AREA (DUE TO
EXPECTED POSITION OF MENTIONED WEAK CIRCULATION) WHERE SHOWER AND
ISOLATED THUNDERSTORM COVERAGE BY MIDDAY TO AFTERNOON SHOULD BE
GREATEST. GFS SUGGESTS VERY HIGH COLUMN MOISTURE (2+ INCH
PRECIPITABLE WATER) COMING INTO EAST MS BY AFTERNOON AND HEAVY
DOWNPOURS SHOULD RESULT. BUT THERE IS NOTHING TO FOCUS TRAINING
CONVECTION AND CELLS SHOULD HAVE DECENT MOVEMENT SO THE RISK OF
EXCESSIVE RAIN DEEMED NOT GREAT AT PRESENT. CLOUDS AND SHOWERS IN
PORTIONS OF EASTERN MS WILL LIKELY KEEP TEMPS FROM GETTING OUT OF
THE MID 80S...BUT FURTHER WEST SPOTTY SUNSHINE WILL INCREASINGLY GET
HIGHS NEARER 90 DEGREES. DECENT COVERAGE OF SHOWERS SHOULD CONTINUE
THROUGH MID SUNDAY EVENING BEFORE ONLY ISOLATED SHOWERS REMAIN OVER
MAINLY NORTHERN ZONES THROUGHOUT THE REMAINDER OF THE NIGHT. LOWS BY
MONDAY MORNING SHOULD BE IN THE UPPER 60S TO LOWER 70S.
NO HAZARDOUS WEATHER ANTICIPATED IN THE SHORT TERM PERIOD...DESPITE
THE EVOLUTION TO DECENT SHOWER AND THUNDERSTORM CHANCES ON SUNDAY.
MODEST INSTABILITY ON SUNDAY SHOULD MODULATE STORM STRENGTH TO
NON-WORRISOME LEVELS ALTHOUGH A BIT OF BRIEF GUSTY WIND NOT
IMPOSSIBLE WITH THE MORE INTENSE STORMS GIVEN AMBIENT FLOW. AS
MENTIONED ABOVE...HEAVY RAIN TOTALS NOT EXPECTED TO BE AN ISSUE AT
THIS TIME. /BB/
LONG TERM...MONDAY THROUGH FRIDAY...MEDIUM/LONG RANGE MODELS IN
AGREEMENT WITH EVOLUTION OF THE PATTERN THROUGH THIS TIME PERIOD.
MID LEVEL COLD CORE LOW OVER THE CENTRAL PLAINS AT THE BEGINNING OF
THE PERIOD WITH NEAR 600 DM H5 HIGH ANCHORED OVER THE OH VALLEY.
POSITION OF THESE FEATURES WILL ALLOW A DEEP MOIST SE FLOW TO BE
ENTRENCHED OVER THE CWA. WHILE PRECIPITABLE WATERS WILL BE AT OR
ABOVE TWO INCHES MONDAY AND TUESDAY...BELIEVE THREAT FOR WIDESPREAD
TROPICALLY HEAVY RAIN WILL BE REDUCED GIVEN 20-30 KNOT DEEP LAYER
FLOW AND LACK OF LOW LEVEL FOCUS. MAX TEMPS WILL STRUGGLE TO REACH
THE LOWER 90S MODAY AND TUESDAY WITH EXPECTED EARLY ONSET OF
CONVECTION.
COLD CORE LOW CONTINUES TO RETROGRADE WEST BEYOND TUESDAY ALLOWING
MEAN FLOW TO RELAX AND BACK TO A MORE EASTERLY DIRECTION. THIS
SHOULD EFFECTIVELY CUT OFF THE DEEP TROPICAL MOISTURE FEED FROM THE
GULF AND FORECAST PRECIPITABLE WATERS SHOW THIS WITH VALUES DROPPING
BELOW 2 INCHES. CONVECTIVE COVERAGE SHOULD LESSEN TO ISOLATED DURING
THE LATTER HALF OF THE WEEK. MAX TEMPS SHOULD BEGIN MODERATING
DURING THIS TIMEFRAME AS CONVECTIVE COVERAGE DIMINISHES AND HOLDS
OFF UNTIL MID/LATE AFTERNOON./26/
&&
.AVIATION...
VFR CONDS AND LGT NLY SFC WINDS CAN BE XPCTD THRU THE DAY TODAY...
WITH THE WINDS BECMG SELY LATER TONIGHT. ISOLD SHRA/TSRA ARE PSBL
ACROSS FAR ERN/SERN MS THIS AFTN...BEFORE SHRA/TSRA CHANCES RETURN
AREAWIDE TOMORROW. MVFR VSBY RESTRICTIONS WL BE PSBL AT HBG/MEI
10-13Z TOMORROW...ESPECIALLY IF ANY RAIN FALLS IN THESE AREAS THIS
AFTN. /BK/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 91 69 88 72 / 8 7 35 35
MERIDIAN 89 69 86 71 / 14 18 57 35
VICKSBURG 90 66 89 69 / 4 6 24 24
HATTIESBURG 91 71 88 71 / 25 17 42 30
NATCHEZ 90 68 88 69 / 7 9 24 17
GREENVILLE 89 67 90 71 / 2 5 26 37
GREENWOOD 90 67 88 71 / 4 6 41 45
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AEG/BK
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
955 AM MDT SAT JUL 13 2013
.UPDATE...
MAIN FOCUS TODAY WILL BE CONVECTION DEVELOPING ALONG A PREFRONTAL
TROUGH ALONG THE DAKOTA MONTANA BORDER AND OTHER CONVECTION IN
UPSLOPE AREAS MAINLY SOUTH OF BILLINGS. THE EASTERN MONTANA
CONVECTION APPEARS TO START IN THE STATE BUT HRRR MODEL
CONSISTENTLY LIMITS ITS GROWTH UNTIL IT ADVANCES INTO THE DAKOTAS.
DID NUDGE UP FALLON COUNTY POPS A BIT. WEST OF THIS AREA THINK
THAT CONVECTION WILL INITIATE IN UPSLOPE AREAS AND THEN PROGRESS
INTO THE PLAINS THIS EVENING. DRIED OUT AREAS LIKE ROUNDUP...
HARDIN...HYSHAM AND FORSYTH THIS AFTERNOON AS THEY WILL BE
WAITING FOR THE CONVECTION TO REACH THEM. FLY IN THE OINTMENT IS A
WEAK FRONT OVER NORTH CENTRAL MONTANA BUT ITS LIFT APPEARS TO WEAK
TO TRIGGER THE CONVECTION ON ITS OWN GIVEN CAPE LIMITED TO 500
J/KM IN CENTRAL AREAS. UPDATE SENT. BORSUM
&&
.SHORT TERM...VALID FOR TDY AND SUN...
SYNOPSIS...A BROAD MID LEVEL MOISTURE PLUME IS CIRCULATING AROUND
SOUTH PLAINS RIDGE THIS MORNING...WITH MOISTURE TONGUE PUSHING
INTO SOUTHERN AND EASTERN ZONES. A MID LEVEL DISTURBANCE OVER
WASHINGTON IS TRACKING EASTWARD WITH JET ENERGY OUT AHEAD PUSHING
OVER THE AREA. AS THE DISTURBANCE MOVES ACROSS NORTHERN MONTANA
OVER THE NEXT 24 HOURS A COLD FRONT WILL MOVE SOUTHWARD ACROSS THE
AREA THIS AFTERNOON AND EVENING. NORTHERLY WINDS BEHIND THE FRONT
WILL TURN EASTERLY TONIGHT AND WILL BEGIN TO ADVECT VERY MOIST LOW
LEVEL AIR (60+ DEW POINTS) INTO THE AREA. COMBINATION OF THE COLD
FRONT...JET ENERGY ALOFT AND INCREASED LOW AND MID LEVEL MOISTURE
ALONG WITH UPSLOPE NORTH TO EAST WINDS AT THE SURFACE WILL BRING
THE POTENTIAL FOR SCATTERED THUNDERSTORMS THROUGH THE WEEKEND WITH
THE BEST PRECIPITATION CHANCES BEING ALONG AND SOUTH OF A
LIVINGSTON TO BILLINGS TO BAKER LINE.
TODAY...COLD FRONT SHOULD MOVE THROUGH MOST OF THE AREA THIS
AFTERNOON. TIMING CURRENTLY LOOKS TO BE BEFORE NOON IN
HARLOWTON...BEFORE 3 PM IN BILLINGS...BEFORE 6 PM IN BAKER AND
SHERIDAN...HOWEVER CONVECTIVE OUTFLOWS TODAY MAY SKEW THIS TIMING
FASTER. TEMPERATURES SHOULD MAKE THE MID TO UPPER 80S WEST AND
CENTRAL THIS AFTERNOON...WITH LOWER 90S EXPECTED OVER EASTERN
ZONES. CONVERGENCE ALONG THE FRONT COMBINED WITH UPSLOPE INTO
AREA MOUNTAINS/FOOTHILLS WILL GENERATE SCATTERED THUNDERSTORMS
THIS AFTERNOON INTO TONIGHT. STRONG FORCING IS MISSING FROM THE
INGREDIENT POOL TODAY AS UPPER LEVEL ENERGY IS FOCUSED FURTHER
NORTH. THUS NOT SEEING MUCH CHANCE FOR STRONG OR SEVERE STORMS
TODAY EXCEPT FOR FALLON AND CARTER COUNTIES WHERE FOR A BRIEF
PERIOD EARLY AFTERNOON STORMS COULD BE STRONG TO SEVERE ALONG A
PREFRONTAL TROF IN VICINITY OF DEEPER PLAINS MOISTURE. GIVEN THAT
THE EARLY AFTERNOON TIMING IS NOT IDEAL AND THE LACK OF ANY STRONG
FORCING MECHANISM...WILL LEAVE SEVERE MENTION OUT FOR NOW AND
MENTION STRONGER STORM POSSIBILITY IN HWO. JET DIVERGENCE MOVING
OVER THE AREA TONIGHT ALONG WITH SOME QG FORCING WILL KEEP CHANCES
FOR THUNDERSTORMS GOING OVERNIGHT. BY THE EARLY MORNING HOURS WILL
SEE SURFACE TO 850 WINDS TURN EASTERLY...TAPPING INTO VERY MOIST
LOW LEVEL AIR OVER THE DAKOTAS.
TOMORROW...MAIN THREAT FOR SUNDAY WILL BE THE POTENTIAL FOR HEAVY
RAINFALL WITH STORMS OVER AREAS FROM ROSEBUD AND SHERIDAN COUNTIES
EAST. 60+ DEGREE DEW POINT AIRMASS WILL BE PULLED INTO THE AREA BY
LOW LEVEL EASTERLY WINDS. ISENTROPIC LIFT OVER SATURDAYS FRONTAL
BOUNDARY (310K SURFACE) COMBINED WITH QG FORCING AND JET
DIVERGENCE ALOFT WILL PROVIDE LIFT IN THE ABSENCE OF STRONG
VORTICITY ADVECTION. MODELS ARE PROGGING PRECIPITABLE WATER VALUES
UP TO 1.5 INCHES OVER SOUTHEAST MONTANA/NORTH CENTRAL
WYOMING...WITH SLOW STORM MOVEMENT OF 15KTS. AS A RESULT COULD
SEE TORRENTIAL RAINFALL WITH ANY STORMS OVER THESE AREAS SUNDAY.
FURTHER WEST STORMS WILL MAINLY BE AN AFTERNOON/EVENING EVENT WITH
A DISTURBANCE PUSHING NORTHEAST OUT OF IDAHO AND WESTERN WYOMING.
STORM MOVEMENT LOOKS FASTER OVER SOUTH CENTRAL MONTANA WITH LOWER
DEW POINT AIR IN PLACE...THUS THREAT FOR HEAVY RAIN LOOKS MUCH
LOWER THAN FURTHER EAST. LACK OF STRONG FORCING AND GENERALLY WEAK
SURFACE TO 500 MB WINDS ALSO MINIMIZE SEVERE THREAT ON SUNDAY.
CHAMBERS
.LONG TERM...VALID FOR MON...TUE...WED...THU...FRI...
HEIGHTS WILL BUILD OVER OUR REGION NEXT WEEK AS ANOMALOUS OHIO
VALLEY LOW RETROGRADES TOWARD THE DESERT SOUTHWEST. OVERALL
PATTERN PROMISES TO BE VERY SUMMERY WITH PERSISTENT ABOVE NORMAL
TEMPERATURES...BUT THERE ARE SOME DETAILS WHICH WILL IMPACT OUR
CONVECTIVE CHANCES.
ABUNDANT LOW LEVEL MOISTURE PER PERSISTENT EAST WINDS...COMBINED
WITH OCCASIONAL SURGES OF MONSOONAL FLOW FROM THE SW AND WEAK
PACIFIC SHORTWAVES...WILL KEEP AT LEAST A SLIGHT CHANCE OF TSTMS
GOING EACH DAY THROUGH NEXT FRIDAY. BEST CHANCE OF STORMS LOOKS TO
BE IN OUR EAST INITIALLY...BUT THEN AS THE RIDGE BUILDS AND MID
LEVEL TEMPS WARM...OUR CONVECTIVE CHANCES SHOULD BE GREATEST OVER
OUR WESTERN/SOUTHERN MTNS BY WED-FRI. STRONGEST LOW LEVEL FEATURE
IS A CANADIAN COLD FRONT MONDAY NIGHT INTO TUESDAY WHICH SHOULD
AID IN CONVECTIVE DEVELOPMENT DURING THIS PERIOD.
TEMPS WILL REMAIN ABOVE NORMAL WITH HIGHS MOSTLY IN THE UPPER 80S
TO MID 90S THROUGHOUT THE EXTENDED. TUESDAY LOOKS TO BE THE
COOLEST DAY PER THE AFOREMENTIONED FROPA AND ONSET OF STRONGER
UPSLOPE WINDS. POTENTIAL EXISTS FOR ANOTHER WEAK BACKDOOR FRONT
THURSDAY THOUGH MODELS NOT IN AGREEMENT HERE. MODELS CURRENTLY NOT
INDICATING A STRONG DOWNSLOPE OR PREFRONTAL DAY WHICH WOULD ALLOW
US TO GET BACK TO THE CENTURY MARK.
ONE OTHER NOTE...CONVECTION NEXT WEEK WILL BE IN WEAK SHEAR
ENVIRONMENTS AND BATTLING WARMER MID LEVEL TEMPS...SO NOT
ANTICIPATING SEVERE STORMS AT THIS TIME. PWATS WILL REMAIN HIGH
SO LOCALLY HEAVY RAIN COULD BE AN ISSUE WITH ANY STORMS THAT
DEVELOP.
JKL
&&
.AVIATION...
VFR CONDITIONS AND DRY WEATHER WILL PREVAIL THIS MORNING. A
CANADIAN COLD FRONT WILL BRING A SHIFT TO N-NE WINDS THIS
AFTERNOON/EVENING WITH GUSTS OF 15-25 KTS. THIS FRONT COMBINED
WITH A WEAK DISTURBANCE FROM THE SW WILL ALLOW FOR ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS TO DEVELOP AFTER 18Z. LOCAL
MVFR IS POSSIBLE IN ANY HEAVIER SHOWERS. JKL
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SUN MON TUE WED THU FRI
-------------------------------------------------------
BIL 089 059/084 061/094 065/089 065/096 066/093 065/094
1/B 32/T 32/T 22/T 22/T 22/T 22/T
LVM 085 048/083 052/095 053/091 057/095 055/093 056/094
3/T 33/T 32/T 23/T 32/T 22/T 22/T
HDN 091 060/086 061/096 062/092 063/097 062/094 063/095
1/B 33/T 32/T 22/T 22/T 22/T 22/T
MLS 093 060/084 065/094 068/092 067/096 068/095 066/093
1/U 34/T 32/T 22/T 22/T 22/T 22/T
4BQ 094 060/084 062/092 063/092 063/095 063/092 065/092
2/T 36/T 32/T 22/T 21/B 12/T 22/T
BHK 091 059/081 060/088 064/090 064/092 064/092 064/088
4/T 36/T 32/T 32/T 21/B 22/T 22/T
SHR 089 056/084 058/092 058/091 059/093 059/092 058/093
3/T 34/T 33/T 32/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1102 AM CDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 1102 AM CDT SAT JUL 13 2013
OVERNIGHT MCS ACROSS SOUTHERN MN AND NORTHERN IA HAS BEEN SLOWLY
DIMINISHING DURING THE PAST FEW HOURS...IN RESPONSE TO THE NORMAL
WEAKENING OF THE LOW LEVEL JET. THIS WEAKENING WAS DEFINITELY
EVIDENT ON THE WOOD LAKE PROFILER...WITH WESTERLY 850MB WINDS AT
08Z OF 45 KT AND AT 14Z OF 10 KT. ANTICIPATING THE WEAKENING OF
THE MCS TO CONTINUE OVER THE NEXT FEW HOURS. CLOUD COVER...ON THE
OTHER HAND...MAY TAKE ITS TIME CLEARING. THE MCS CLOUD IS SITUATED
RIGHT UNDERNEATH A 200-500MB RIDGE AXIS...WHICH MEANS THERE IS
LITTLE ADVECTIVE FLOW TO HELP CLEAR IT OUT. RAP 300MB WIND
FORECAST DOES SHOW A NORTHEAST WIND OVER CENTRAL/EASTERN WI AT
15Z...ON THE EAST SIDE OF THE RIDGE AXIS...TURNING MORE EASTERLY
THIS AFTERNOON. THIS WIND SWITCH SHOULD HELP TO AT LEAST PARTIALLY
CLEAR SKIES OUT OVER WISCONSIN. MEANWHILE...CLOUDS MAY GET STUCK
OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND THUS KEPT THIS
AREA MOSTLY CLOUDY THROUGH THE DAY. ADDITIONALLY...HAVE HAD TO
COOL HIGH TEMPERATURES A LITTLE MORE WEST OF THE MISSISSIPPI
RIVER TO ACCOUNT FOR MORE CLOUD. SHOULD CLOUDS CLEAR FASTER THAN
EXPECTED...TEMPERATURES WILL END UP WARMER.
ANOTHER ISSUE TO CONTEND WITH IS AN MCV THAT ORIGINATED OUT OF AN
MCS OVER WESTERN NEBRASKA LAST NIGHT. THIS MCV CAN BE SEEN ON
WATER VAPOR JUST EAST OF WATERTOWN SOUTH DAKOTA. DPVA AHEAD OF
THIS MCV...AN INCREASE OF 850-700MB MOISTURE TRANSPORT AHEAD OF
IT...AS WELL AS THE TRANSPORT ACTING ON 500-1000 J/KG OF MUCAPE
PER 13.14Z HRRR ANALYSIS HAS DEVELOPED SOME SHOWERS AND
THUNDERSTORMS OVER SOUTHWEST MN INTO THE BACK SIDE OF THE
WEAKENING MCS. AS THE MCV LIFTS NORTHEAST AROUND THE 500MB RIDGE
AXIS IN PLACE OVER THE FORECAST AREA...SOME OF THOSE
SHOWERS/THUNDERSTORMS COULD END UP CLIPPING SOUTHEAST MN DURING
THE AFTERNOON HOURS. AS A RESULT...ADDED A 20 PERCENT CHANCE OVER
SOUTHEAST MN FOR THE AFTERNOON. CERTAINLY THIS POTENTIAL ALSO
LEADS TO THE MORE PESSIMISTIC VIEW ON CLOUDS AND HIGHS TODAY.
FINALLY...13.14Z RAP AND 13.12Z NAM DEPICT A LITTLE DIFFERENT
850MB MOISTURE TRANSPORT LOCATION TONIGHT. THEY HAVE BOTH SHIFTED
THE OVERALL AXIS EAST...AIMED MORE AT CENTRAL MN VERSUS NORTHWEST
MN. IF THESE ARE CORRECT...THE COMBINATION OF THE OUTFLOW PRODUCED
BY THE ROUNDS OF SHOWERS/STORMS TODAY AND INSTABILITY OVER SIOUX
FALLS AREA COULD TRY TO INITIATE AN MCS OVER CENTRAL MN THIS
EVENING. CORFIDI VECTORS WHICH ARE NORTHERLY WOULD BRING THIS
TOWARDS THE FORECAST AREA. HOWEVER...THE 850MB MOISTURE TRANSPORT
AND INSTABILITY DRAMATICALLY DROPS OFF OVER THE FORECAST
AREA...SUGGESTING THE CONVECTION WOULD PROBABLY FALL APART.
ADDITIONALLY AND LIKELY CORRELATED...THE MCS MAINTENANCE
PROBABILITIES ARE VERY LOW SOUTH OF MINNEAPOLIS. THUS...HAVE KEPT
A DRY FORECAST FOR TONIGHT FOR NOW. SOMETHING TO WATCH.
UPDATE ISSUED AT 544 AM CDT SAT JUL 13 2013
CONVECTION CONTINUES TO TRACK TO THE EAST ALONG THE LEADING EDGE
OF THE LOW LEVEL MOISTURE TRANSPORT AND 0-3KM MUCAPE AXIS ACROSS
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA. WHILE THE RAINFALL RATES
HAVE DISSIPATED ALONG THE FAR EASTERN PORTION OF THIS BAND...A
FAIRLY WIDESPREAD AREA OF MODERATE RAIN CONTINUES TO EXPAND
EASTWARD INTO WESTERN WISCONSIN. FURTHER
SOUTHWEST/WEST...CONVECTION PERSISTS NEAR THE TWIN CITIES AND
SOUTHWARD WHERE THE INSTABILITY REMAINS THE HIGHEST AT AROUND
500-1000 J/KG OF MUCAPE BASED ON 13.10Z RAP ANALYSIS. WITH THIS
AXIS OF INSTABILITY NOT MAKING MUCH PROGRESS EASTWARD THIS
MORNING...EXPECT THAT THE MORE IMPRESSIVE RADAR RETURNS WILL MAKE
IT MUCH FURTHER EAST. HOW FAR EAST THE MAIN BAND OF RAIN MAKES IT
CONTINUES TO BE THE MAIN QUESTION WITH THIS FORECAST AND WILL
UPDATE THE FORECAST THIS MORNING TO TAKE INTO ACCOUNT THIS SHIFT
FURTHER TO THE EAST OF THE RAIN BAND.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 555 AM CDT SAT JUL 13 2013
FORECAST PROBLEMATIC RIGHT OFF THE BAT THIS MORNING...AS SOME
850-700MB MOISTURE TRANSPORT/CONVERGENCE WERE SUSTAINING A COMPLEX
OF SHRA/TSRA JUST NORTHWEST OF THE FCST AREA. THESE WERE HEADED
EAST-SOUTHEAST AND POISED TO SPREAD ACROSS THE TAF SITES WITH SOME
MVFR AND BRIEF IFR CONDITIONS THIS MORNING. IMPACTS LOOK TO BE
MAINLY 13-15Z AT KRST AND 15-17Z AT KLSE. ADDED TEMPO MVFR/IFR
CIGS/VSBYS IN TSRA/CB AT KRST. LEFT KLSE AS VCSH FOR NOW AS MODEL
CONSENSUS WEAKENS THE FORCING AND DISSIPATES THE CONVECTION BEFORE
IT REACHES KLSE. GIVEN RADAR TRENDS AND MODELS NOT BEING STRONG
ENOUGH WITH THE CONVECTION ALL NIGHT...SUSPECT AT LEAST SOME SHRA
WILL MAKE IT TO KLSE THIS MORNING.
AFTER THIS MORNING...THE FORCING AND LIFT SHIFT BACK TO THE WEST AND
NORTHWEST...CLOSER TO THE STALLED FRONTAL BOUNDARY IN NORTHWEST MN.
GOOD VFR CONDITIONS EXPECTED FOR THIS AFTERNOON/TONIGHT AS HIGH
PRESSURE AND A SEASONABLY DRY LOW LEVEL AIRMASS /DEW POINTS AROUND
60F VS. 70F/ REMAIN OVER THE AREA. GRADIENT WINDS OF 6-10KTS AND
BOUNDARY LAYER MIXING TONIGHT SHOULD KEEP ANY BR IN THE 09-13Z TIME
FRAME SUN MORNING TO A MINIMUM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION...CORRECTED
NWS LA CROSSE WI
557 AM CDT SAT JUL 13 2013
.UPDATE...THIS MORNING
ISSUED AT 544 AM CDT SAT JUL 13 2013
CONVECTION CONTINUES TO TRACK TO THE EAST ALONG THE LEADING EDGE
OF THE LOW LEVEL MOISTURE TRANSPORT AND 0-3KM MUCAPE AXIS ACROSS
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA. WHILE THE RAINFALL RATES
HAVE DISSIPATED ALONG THE FAR EASTERN PORTION OF THIS BAND...A
FAIRLY WIDESPREAD AREA OF MODERATE RAIN CONTINUES TO EXPAND
EASTWARD INTO WESTERN WISCONSIN. FURTHER
SOUTHWEST/WEST...CONVECTION PERSISTS NEAR THE TWIN CITIES AND
SOUTHWARD WHERE THE INSTABILITY REMAINS THE HIGHEST AT AROUND
500-1000 J/KG OF MUCAPE BASED ON 13.10Z RAP ANALYSIS. WITH THIS
AXIS OF INSTABILITY NOT MAKING MUCH PROGRESS EASTWARD THIS
MORNING...EXPECT THAT THE MORE IMPRESSIVE RADAR RETURNS WILL MAKE
IT MUCH FURTHER EAST. HOW FAR EAST THE MAIN BAND OF RAIN MAKES IT
CONTINUES TO BE THE MAIN QUESTION WITH THIS FORECAST AND WILL
UPDATE THE FORECAST THIS MORNING TO TAKE INTO ACCOUNT THIS SHIFT
FURTHER TO THE EAST OF THE RAIN BAND.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 555 AM CDT SAT JUL 13 2013
FORECAST PROBLEMATIC RIGHT OFF THE BAT THIS MORNING...AS SOME
850-700MB MOISTURE TRANSPORT/CONVERGENCE WERE SUSTAINING A COMPLEX
OF SHRA/TSRA JUST NORTHWEST OF THE FCST AREA. THESE WERE HEADED
EAST-SOUTHEAST AND POISED TO SPREAD ACROSS THE TAF SITES WITH SOME
MVFR AND BRIEF IFR CONDITIONS THIS MORNING. IMPACTS LOOK TO BE
MAINLY 13-15Z AT KRST AND 15-17Z AT KLSE. ADDED TEMPO MVFR/IFR
CIGS/VSBYS IN TSRA/CB AT KRST. LEFT KLSE AS VCSH FOR NOW AS MODEL
CONSENSUS WEAKENS THE FORCING AND DISSIPATES THE CONVECTION BEFORE
IT REACHES KLSE. GIVEN RADAR TRENDS AND MODELS NOT BEING STRONG
ENOUGH WITH THE CONVECTION ALL NIGHT...SUSPECT AT LEAST SOME SHRA
WILL MAKE IT TO KLSE THIS MORNING.
AFTER THIS MORNING...THE FORCING AND LIFT SHIFT BACK TO THE WEST AND
NORTHWEST...CLOSER TO THE STALLED FRONTAL BOUNDARY IN NORTHWEST MN.
GOOD VFR CONDITIONS EXPECTED FOR THIS AFTERNOON/TONIGHT AS HIGH
PRESSURE AND A SEASONABLY DRY LOW LEVEL AIRMASS /DEW POINTS AROUND
60F VS. 70F/ REMAIN OVER THE AREA. GRADIENT WINDS OF 6-10KTS AND
BOUNDARY LAYER MIXING TONIGHT SHOULD KEEP ANY BR IN THE 09-13Z TIME
FRAME SUN MORNING TO A MINIMUM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
555 AM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 555 AM CDT SAT JUL 13 2013
FORECAST PROBLEMATIC RIGHT OFF THE BAT THIS MORNING...AS SOME
850-700MB MOISTURE TRANSPORT/CONVERGENCE WERE SUSTAINING A COMPLEX
OF SHRA/TSRA JUST NORTHWEST OF THE FCST AREA. THESE WERE HEADED
EAST-SOUTHEAST AND POISED TO SPREAD ACROSS THE TAF SITES WITH SOME
MVFR AND BRIEF IFR CONDITIONS THIS MORNING. IMPACTS LOOK TO BE
MAINLY 13-15Z AT KRST AND 15-17Z AT KLSE. ADDED TEMPO MVFR/IFR
CIGS/VSBYS IN TSRA/CB AT KRST. LEFT KLSE AS VCSH FOR NOW AS MODEL
CONSENSUS WEAKENS THE FORCING AND DISSIPATES THE CONVECTION BEFORE
IT REACHES KLSE. GIVEN RADAR TRENDS AND MODELS NOT BEING STRONG
ENOUGH WITH THE CONVECTION ALL NIGHT...SUSPECT AT LEAST SOME SHRA
WILL MAKE IT TO KLSE THIS MORNING.
AFTER THIS MORNING...THE FORCING AND LIFT SHIFT BACK TO THE WEST AND
NORTHWEST...CLOSER TO THE STALLED FRONTAL BOUNDARY IN NORTHWEST MN.
GOOD VFR CONDITIONS EXPECTED FOR THIS AFTERNOON/TONIGHT AS HIGH
PRESSURE AND A SEASONABLY DRY LOW LEVEL AIRMASS /DEW POINTS AROUND
60F VS. 70F/ REMAIN OVER THE AREA. GRADIENT WINDS OF 6-10KTS AND
BOUNDARY LAYER MIXING TONIGHT SHOULD KEEP ANY BR IN THE 09-13Z TIME
FRAME SUN MORNING TO A MINIMUM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
544 AM CDT SAT JUL 13 2013
.UPDATE...THIS MORNING
ISSUED AT 544 AM CDT SAT JUL 13 2013
CONVECTION CONTINUES TO TRACK TO THE EAST ALONG THE LEADING EDGE
OF THE LOW LEVEL MOISTURE TRANSPORT AND 0-3KM MUCAPE AXIS ACROSS
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA. WHILE THE RAINFALL RATES
HAVE DISSIPATED ALONG THE FAR EASTERN PORTION OF THIS BAND...A
FAIRLY WIDESPREAD AREA OF MODERATE RAIN CONTINUES TO EXPAND
EASTWARD INTO WESTERN WISCONSIN. FURTHER
SOUTHWEST/WEST...CONVECTION PERSISTS NEAR THE TWIN CITIES AND
SOUTHWARD WHERE THE INSTABILITY REMAINS THE HIGHEST AT AROUND
500-1000 J/KG OF MUCAPE BASED ON 13.10Z RAP ANALYSIS. WITH THIS
AXIS OF INSTABILITY NOT MAKING MUCH PROGRESS EASTWARD THIS
MORNING...EXPECT THAT THE MORE IMPRESSIVE RADAR RETURNS WILL MAKE
IT MUCH FURTHER EAST. HOW FAR EAST THE MAIN BAND OF RAIN MAKES IT
CONTINUES TO BE THE MAIN QUESTION WITH THIS FORECAST AND WILL
UPDATE THE FORECAST THIS MORNING TO TAKE INTO ACCOUNT THIS SHIFT
FURTHER TO THE EAST OF THE RAIN BAND.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1120 PM CDT FRI JUL 12 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SOME THUNDERSTORMS
ARE EXPECTED TO DEVELOP OVER CENTRAL-SOUTHERN MN OVERNIGHT. THE
MOTION OF THE THUNDERSTORMS WOULD BE EAST TOWARD KRST HOWEVER THE
INSTABILITY RAPIDLY DROPS OFF WEST OF KRST. THEREFORE...A
DIMINISHING TREND TO THE TSRA ACTIVITY AS IT MOVES SOUTHEAST
TOWARD KRST/KLSE IS EXPECTED...WITH ONLY VFR CLOUDS REMAINING AND
POSSIBLY SHRA AROUND SUNRISE.
THUNDERSTORMS ONGOING WILL CAUSE A THICK COVER OF CIRRUS AT HIGH
LEVELS. WILL MONITOR THE TSRA ACTIVITY OVERNIGHT...BUT CURRENTLY
EXPECT A DIMINISHING TREND AND LITTLE EFFECT AT THE AIRPORTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1255 PM MST SAT JUL 13 2013
.SYNOPSIS...
A DEEP MONSOON AIRMASS WELL REMAIN OVER THE EASTERN PORTION OF THE
REGION THE NEXT SEVERAL DAYS. THERE WILL CONTINUE THE THREAT OF
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
CENTRAL AND EASTERN ARIZONA MOUNTAINS. AFTERNOON TEMPERATURES WILL
WARM TO NEAR OR SLIGHTLY ABOVE NORMAL THROUGH EARLY NEXT WEEK AND
THEN COOL OFF SOME BY THE MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
EARLY AFTERNOON SATELLITE IMAGERY REVEALS MOSTLY SUNNY SKIES ACROSS
THE LOWER DESERTS OF AZ/SE CA...WITH A FEW CLUSTERS OF STORMS ACROSS
THE REGION. STORMS BEGINNING TO FIRE ACROSS SOUTHERN/EASTERN ARIZONA
AS OF 1930Z...A FEW HOURS LATER THAN THE HRRR MODEL INDICATED
EARLIER BUT PRETTY MUCH ON SCHEDULE. NOT MUCH HAS MADE ITS WAY INTO
THE FORECAST AREA YET EXPECT FOR A LONE STORM NEAR QUARTZSITE /WHICH
HAS SINCE DISSIPATED/. THANKS TO EARLY MORNING CLOUD COVER...TEMPS
HAVE SLOWLY CREPT UPWARD AND WE ARE JUST NOW ECLIPSING THE CENTURY
MARK AT PHOENIX. STILL THINK WE CAN SQUEEZE OUT A FEW MORE DEGREES
BEFORE LATE AFTERNOON AND MOST LOCATIONS SHOULD END UP WITHIN 2-3
DEGREES OF NORMAL.
MDCRS SOUNDINGS OUT OF KPHX INDICATE THAT MOISTURE HAS NOT MIXED OUT
MUCH AT ALL WITH BL MIXING RATIOS REMAINING AT OR ABOVE 10-11 G/KG.
THIS SEEMS TO MATCH UP QUITE WELL WITH RAP13 FORECAST SOUNDINGS AND
SUGGESTS THAT ABOUT 1000 J/KG OF UNCAPPED MLCAPE RESIDES ACROSS THE
REGION AT PRESENT /MUCH MUCH LESSER VALUES ACROSS SW AZ/SE CA/.
HOWEVER...THIS QUICKLY GETS CAPPED OFF BETWEEN 00Z-02Z. THUS WE HAVE
A NARROW WINDOW OF OPPORTUNITY FOR STORM DEVELOPMENT ACROSS THE
DESERTS BEFORE THINGS QUICKLY DIE OFF LATE THIS AFTERNOON. THE MAIN
TRIGGER APPEARS TO BE IN THE FORM OF A REMNANT MCV PRESENTLY OVER
WESTERN PIMA COUNTY...BIG QUESTION IS HOW MUCH NORTHWARD PROGRESS
CAN IT MAKE BEFORE THE CAP STRENGTHENS. POPS WERE RAISED A FEW
PERCENT ACROSS THE DESERTS THROUGH 00Z BUT QUICKLY DROP OFF BELOW 10
PERCENT BY MID/LATE EVENING. GIVEN PRECIPITABLE WATER VALUES AT OR
ABOVE 1.7 INCHES...PERIODS OF HEAVY RAIN ARE ALMOST A GIVEN. GUSTY
WINDS ALSO A POSSIBILITY AS WELL WITH THE STRONGEST STORMS.
SLIGHT DRYING EXPECTED TO WORK ITS WAY IN FROM THE WEST ON
SUNDAY...ALTHOUGH MIXING RATIOS WILL REMAIN ABOVE 7 G/KG IN THE WEST
AND 8-9 G/KG IN THE EAST. UNFORTUNATELY...NOT MUCH IN THE WAY OF
DISCERNIBLE SHORTWAVES IN THE FLOW PER THE MODELS TOMORROW...SO ITS
HARD TO SAY IF MUCH WILL DEVELOP ASIDE FROM THE NORMAL
TERRAIN-DRIVEN STORMS. FLOW IN THE 700-300MB LAYER WEAKENS
CONSIDERABLY TOMORROW AND I THINK THAT SHOULD PRECLUDE MUCH FROM
MAKING ITS WAY OFF THE MOUNTAINS INTO THE DESERTS. WILL MAINTAIN LOW
GRADE CLIMO POPS FOR THE REGION SUNDAY AFTERNOON AND EVENING. NAM
SEEMS TO HAVE THE MOST INSTABILITY ACROSS THE DESERTS TOMORROW WITH
A SCANT 200 J/KG...HARDLY A NOTEWORTHY AMOUNT.
FORECAST FOR THE FIRST HALF OF THIS WEEK IS RATHER INTERESTING TO
SAY THE LEAST. UPPER LEVEL LOW PRESSURE OVER THE OHIO VALLEY IS
ALREADY BEGINNING TO RETROGRADE AND ALL OPERATIONAL MODELS AND
ENSEMBLES INDICATE IT WILL MOVE INTO NEW MEXICO AND ARIZONA BY
MONDAY/TUESDAY. HARD TO IMAGINE AN UPPER LOW RETROGRADING TO THAT
DEGREE...BUT ITS BEEN ADVERTISED FOR SEVERAL DAYS NOW AND WV
IMAGERY CLEARLY DEPICTING THE WESTERLY MOVEMENT OF THE LOW. WE NEVER
REALLY LOSE OUR LOW LEVEL MOISTURE ON MONDAY AND IF ANYTHING...THE
UPPER LOW WILL USHER IN EVEN HIGHER MIXING RATIOS MONDAY INTO
TUESDAY. SOME OF OUR BIGGEST CONVECTIVE EVENTS CLIMATOLOGICALLY HAVE
BEEN EASTERLY WAVES COMING IN FROM THE FOUR CORNERS. THAT BEING THE
CASE...I INCREASED POPS FOR MONDAY INTO TUESDAY...BUT THERE ARE
STILL A TON OF FINER DETAILS THAT NEED TO BE RESOLVED. EUROPEAN
SUGGESTS TUESDAY AFTERNOON/EVENING WILL BE THE MOST ACTIVE WHEREAS
THE GFS GOES AGAINST CLIMO AND ADVERTISES TUESDAY MORNING/AFTERNOON.
ON THE SURFACE THAT MAY NOT SEEM LIKE A TREMENDOUS DIFFERENCE BUT
THIS IMPACTS HOW MUCH INSTABILITY WILL BE PRESENT...NOT TO MENTION
WHAT TEMPS WILL BE TUESDAY AFTERNOON. IF THE GFS VERIFIES...THE
DESERTS COULD ARGUABLY STAY IN THE 80S ALL DAY TUESDAY. EUROPEAN
VERIFIES...PROBABLY LOOKING AT NEAR NORMAL HIGHS AROUND 105. THEN
THERES THE QUESTION OF HOW LONG THE LOW WILL REMAIN OVER THE
AREA...ALL THE WAY INTO FRIDAY PERHAPS. INHERITED FORECAST HAD
HIGHER THAN NORMAL POPS IN PLACE RIGHT INTO NEXT WEEKEND AND IM
INCLINED TO STICK WITH THAT FOR NOW. LIKEWISE GIVEN THE LOW OVERHEAD
AND ABUNDANT MOISTURE IN PLACE...TEMPS FROM MID WEEK ONWARD SHOULD
TREND LOWER THAN CLIMO. PROBABLY STILL AROUND 100 EACH DAY...BUT
NONETHELESS COOLER THAN NORMAL.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS LATE THIS AFTERNOON OR EVENING AT THE
PHOENIX AREA TERMINALS. HOWEVER...GIVEN THE TREND TOWARD LESS
CONVECTIVE ACTIVITY THIS EVENING ON THE LATEST HOURLY
HIGH-RESOLUTION (HRRR) MODEL RUNS...HAVE DECIDED TO KEEP ANY MENTION
OF CONVECTIVE ACTIVITY OUT OF THE TAFS FOR NOW. WINDS TO FOLLOW
TYPICAL DIURNAL TRENDS...BUT WITH WESTERLY BREEZES PERSISTING A
LITTLE LATER INTO THE EVENING HOURS THAN WHAT WE NORMALLY SEE THIS
TIME OF YEAR.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SCT-BKN HIGH CLOUD CIGS TO PREVAIL THROUGH THE TAF PERIOD...WITH
CONVECTIVE ACTIVITY REMAINING WELL TO THE EAST OF THE TERMINALS.
WINDS TO REMAIN ON THE LIGHT SIDE...MAINLY AOB 10KT...AND FAVOR A
PERSISTENT SLY OR SWLY DIRECTION.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
TUESDAY THROUGH FRIDAY...
A RATHER STRONG...AND MOIST UPPER LOW CENTER THAT WILL BE MOVING
INTO THE REGION FROM THE EAST WILL BE THE TRIGGER FOR A RATHER
ACTIVE PERIOD FOR CONVECTIVE ACTIVITY THROUGH THE FORECAST
PERIOD...WITH A GOOD CHANCE FOR WETTING RAINS AT SOME POINT DURING
THE PERIOD AT MOST LOCATIONS IN ARIZONA...WITH LESSER CHANCES FOR
RAIN OVER SOUTHEAST CALIFORNIA. THE BEST CHANCES FOR SIGNIFICANT
RAINS WILL BE OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX.
MINIMUM HUMIDITIES WILL BE HIGHER THAN NORMAL...IN THE 20-30 RANGE
ACROSS THE LOWER DESERTS...AND 40 PERCENT OR HIGHER OVER THE HIGHER
TERRAIN...WITH GOOD TO EXCELLENT OVERNIGHT RECOVERIES. TYPICAL
DAYTIME GUSTY WINDS TO PREVAIL EACH DAY...ESPECIALLY IN PREFERRED
UPSLOPE REGIONS. LOCALLY HIGHER GUSTS WILL ALSO BE POSSIBLE IN
ASSOCIATION WITH THUNDERSTORM OUTFLOW BOUNDARIES DURING THE
AFTERNOON AND EARLY EVENING HOURS.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS
AVIATION...PERCHA
FIRE WEATHER...PERCHA
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
918 AM MST SAT JUL 13 2013
.SYNOPSIS...
A DEEP MONSOON AIRMASS WELL REMAIN OVER THE EASTERN PORTION OF THE
REGION THE NEXT SEVERAL DAYS. THERE WILL CONTINUE THE THREAT OF
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS...MAINLY OVER THE
CENTRAL AND EASTERN ARIZONA MOUNTAINS. AFTERNOON TEMPERATURES WILL
WARM TO NEAR OR SLIGHTLY ABOVE NORMAL THROUGH EARLY NEXT WEEK AND
THEN COOL OFF SOME BY THE MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
MID MORNING WATER VAPOR AND IR SATELLITE IMAGERY REVEALS DECAYING
CONVECTION ACROSS NORTHERN SONORA AND SOUTHERN ARIZONA. QUITE A BIT
OF ACCAS ACROSS THE PHX METRO THIS MORNING...ALSO A FEW
SPRINKLES/LIGHT RAIN SHOWERS NOTED ON RADAR ACROSS PORTIONS OF PINAL
COUNTY. MOST OF THAT HAS DISSIPATED AS OF 16Z BUT CLOUD COVER WILL
REMAIN THROUGH LATE MORNING/EARLY AFTERNOON. WHAT APPEARS TO BE A
REMNANT MCV JUST SOUTH OF NOGALES IS WORKING ITS WAY INTO ARIZONA AS
OF 16Z...ONE POSSIBLE CATALYST FOR STORMS LATER THIS AFTERNOON. WV
IMAGERY ALSO SUGGESTS THE PRESENCE OF ANOTHER VERY WEAK UPPER LEVEL
WAVE NEAR EL PASO.
MORNING TWC/PSR SOUNDINGS AND BLENDED TPW IMAGERY CONTINUES TO
INDICATE NEARLY 1.7 INCHES OF PW ACROSS THE AREA. AS HAS BEEN THE
CASE FOR THE PAST 4 OR 5 DAYS...WE HAVE PLENTY OF MOISTURE IN PLACE
ACROSS THE AREA...WE JUST NEED A SUFFICIENT TRIGGER TO INITIATE
STORMS ACROSS THE REGION. QUITE A VARIETY OF MODEL SOLUTIONS
AVAILABLE TODAY. 12Z NAM INDICATES DEWPOINTS WILL MIX OUT INTO THE
LOWER 50S LATER THIS AFTERNOON...RESULTING IN A 100 J/KG CAP ACROSS
THE DESERTS. RAP13 SEEMS MORE REALISTIC ONLY DROPPING DEWPOINTS INTO
THE UPPER 50S YIELDING A NEGLIGIBLE CAP AROUND 20 J/KG. HRRR AND RAP
MODELS HAVE BEEN DOING A RELATIVELY GOOD JOB FORECASTING STORMS THE
PAST FEW DAYS AND I AM INCLINED TO GIVE THEM THE NOD AGAIN TODAY. I
INCREASED POPS SLIGHTLY FOR THE FORECAST AREA...STILL LOOKING AT 20
PERCENT ACROSS THE METRO...WITH HIGHER VALUES ACROSS NW PINAL AND SW
MARICOPA COUNTIES. GIVEN THE HIGH PW...LOCALIZED HEAVY RAIN REMAINS
A POSSIBILITY ALONG WITH GUSTY WINDS.
AS FOR TEMPS...WERE DOING PRETTY WELL SO FAR WITH TEMPS ALREADY IN
THE LOWER 90S. UNLESS STORMS DEVELOP IN THE NEXT 1-2 HRS WHICH SEEMS
UNLIKELY...HIGHS IN THE 102-105 RANGE CERTAINLY SEEM ATTAINABLE.
ASIDE FROM POPS AND MINOR TWEAKS TO CLOUD COVER...NO OTHER CHANGES
MADE TO THE FORECAST.
&&
.PREVIOUS DISCUSSION...
LOWER CHANCES FOR MONSOON STORMS ARE EXPECTED ON SUNDAY WITH FAIRLY
SIGNIFICANT MID-LEVEL DRYING OCCURRING ACROSS THE REGION ALONG WITH
A EASTWARD PUSH OF LOW LEVEL DRYING THROUGH SOUTHWEST ARIZONA. POPS
ARE TRIMMED BACK FOR SUNDAY AND MAINLY LIMITED TO THE HIGHER TERRAIN
EAST OF PHOENIX. EVEN THOUGH STEERING FLOW WILL BE BASICALLY
NON-EXISTENT...STORM PROPAGATION INTO THE LOWER DESERTS MAY OCCUR
DUE TO DRIER PROFILES LIKELY GIVING RISE TO STRONGER STORM OUTFLOWS.
THE THREAT FOR GUSTY WINDS WILL BE BETTER ON SUNDAY IF ANY STRONG
STORMS MANAGE TO DEVELOP. THE DRIER AIR WILL ALSO ALLOW FOR A
INCREASE IN TEMPERATURES ACROSS THE REGION WITH HIGHS CLIMBING BACK
TO NORMAL LEVELS. MONDAY SHOULD BE FAIRLY SIMILAR TO SUNDAY...BUT
THE DRIER AIR WILL WORK EVEN FURTHER EASTWARD INTO THE SOUTH-CENTRAL
ARIZONA DESERTS...SO VERY LITTLE STORM ACTIVITY IS EXPECTED TO MAKE
IT OUT OF HIGHER TERRAIN AREAS.
MODELS ARE STILL INDICATING A WESTWARD MOVING UPPER LOW FROM THE
OHIO RIVER VALLEY WILL MAKE IT/S WAY INTO THE PLAINS ON MONDAY AND
INTO NEW MEXICO ON TUESDAY. TUESDAY WILL LIKELY BE A TRANSITION DAY
FOR SOUTHERN ARIZONA WITH A SIGNIFICANT MID LEVEL MOISTURE INCREASE
FROM THE EAST AHEAD OF THE UPPER LOW. THE MOISTURE INCREASE WILL
INCREASE MONSOON STORM CHANCES SOMEWHAT ACROSS SOUTH-CENTRAL
ARIZONA...BUT THERE IS STILL NOT ENOUGH CONFIDENCE IN THE MODEL
SOLUTIONS TO GO ANY HIGHER THAN SLIGHT CHANCE POPS. WHAT SEEMS
PLAUSIBLE IS THE INCREASED MID LEVEL MOISTURE WILL CREATE A COOLER
AND CLOUDIER TIME PERIOD DURING THE MIDDLE OF NEXT WEEK WHICH MAY
PROHIBIT A VERY ACTIVE MONSOON PATTERN. STORM CHANCES FOR TUESDAY
AND WEDNESDAY WILL GENERALLY BE FROM MARICOPA COUNTY EASTWARD...BUT
WESTWARD ADVANCING LOW LEVEL MOISTURE WILL BRING INCREASING CHANCES
FOR STORMS ACROSS ALL OF SOUTHERN ARIZONA AND POSSIBLY SOUTHEAST
CALIFORNIA FOR NEXT THURSDAY AND FRIDAY. TEMPERATURES WILL BE ON THE
DOWN TREND STARTING TUESDAY WITH SLIGHTLY BELOW NORMAL HIGHS FOR
SOUTH-CENTRAL ARIZONA PERSISTING THROUGH THE END OF NEXT WEEK AND
NEAR NORMAL HIGHS ACROSS OUR WESTERN ZONES.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA AND KSDL...
PERIODIC MID/HIGH CLOUDS WILL SPREAD OVER CNTRL ARIZONA TERMINALS
THROUGH SUNDAY MORNING. SLIGHT TSRA CHANCES WILL BE PRESENT AGAIN
TODAY...HOWEVER THE PROBABILITY OF OCCURRENCE OVER ANY ONE SITE IS
FAR TOO LOW TO WARRANT A MENTION IN THIS TAF PACKAGE. IN
ADDITION...SHIFTING SFC WINDS ASSOCIATED WITH THUNDERSTORM OUTFLOWS
WILL BE POSSIBLE...HOWEVER LITTLE TO NO CONFIDENCE IN TIMING SUCH
EVENTS PRECLUDES EVEN A TEMPO OR PROB30 GROUP. OUTSIDE OF ANY
CONVECTIVE INFLUENCES...SFC WINDS SHOULD REMAIN LIGHT AND BECOME
W/SW BY LATE MORNING.
SOUTHEAST CA AND SOUTHWEST AZ...INCLUDING KIPL AND KBLH...
SCT/BKN HIGH CLOUDS WILL OCCASIONALLY DRIFT ACROSS SERN CALIFORNIA
THROUGH SUNDAY MORNING. WITH FAIRLY GOOD FORECAST CONFIDENCE...ANY
SHOWERS OR THUNDERSTORMS SHOULD REMAIN WELL TO THE EAST OF THIS
AREA. SFC WINDS WILL REMAIN FAIRLY LIGHT AOB 12KT WITH A GENERAL
PERSISTENT SLY OR SWLY DIRECTION.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
THUNDERSTORM AND WETTING RAIN CHANCES WILL GRADUALLY RETURN TO THE
AREA DURING THE EARLY TO MIDDLE PART OF NEXT WEEK. BY TUESDAY OR
WEDNESDAY...AFTERNOON MINIMUM VALUES WILL IMPROVE...ONLY DROPPING
INTO THE 20-30 PERCENT RANGE WITH ANOTHER INCREASE IN MOISTURE.
OVERNIGHT RECOVERY SHOULD BE GOOD TO EXCELLENT WITH READINGS
CLIMBING ABOVE 40 PERCENT MOST NIGHTS. THE TYPICAL DAYTIME GUSTY
WINDS ARE POSSIBLE EACH DAY...ESPECIALLY IN PREFERRED UPSLOPE
REGIONS. LOCALLY HIGHER GUSTS WILL ALSO BE POSSIBLE IN ASSOCIATION
WITH THUNDERSTORM OUTFLOW BOUNDARIES DURING THE AFTERNOON AND EARLY
EVENING HOURS.
&&
$$
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/KUHLMAN
AVIATION...MO
FIRE WEATHER...LEINS/MO
AREA FORECAST DISCUSSION
NWS MIAMI FL
227 PM EDT SAT JUL 13 2013
.DISCUSSION...
THE LARGE SCALE CIRCULATION DEPICTS A TROUGH OF LOW PRESSURE OVER THE
EASTERN US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC TO
INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND
MONDAY-TUESDAY TIME FRAME. BY WEDNESDAY THE ATLANTIC OCEAN IS
DOMINATED BY TWO LARGE AREAS OF HIGH PRESSURE ONE OVER NORTH AFRICA
AND THE SECOND OVER THE NORTHERN US, WITH MOST OF THE SUBTROPICAL
ATLANTIC UNDER TRADE WINDS. AT THIS TIME THE AREA OF HIGH PRESSURE
OVER NORTH AMERICA BEGINS TO WEAKEN SOMEWHAT. THE WEATHER OVER SOUTH
FLORIDA WILL BE DRIVEN BY FLUCTUATIONS IN MOISTURE MOVING WESTWARD
ON THE SOUTHERN PERIPHERY OF THE ATLANTIC HIGH PRESSURE AND SLIGHT
CHANGES IN THE MID LEVEL TEMPERATURES AS SMALL POCKETS OF COOL AIR
TRAVEL AROUND THE AREA OF HIGH PRESSURE IN THE ATLANTIC. THE
INCREASED MOISTURE ASSOCIATED WITH THE REMNANTS OF CHANTAL ARE
FORECAST TO PUSH NORTHWARD EAST OF THE FLORIDA PENINSULA THIS
WEEKEND FORCED BY A HIGH AMPLITUDE TROUGH OF LOW PRESSURE OVER THE
NORTHERN GULF. THE TROUGH OF LOW PRESSURE OVER THE NORTHERN GULF
COULD GENERATE A WEAK LOW INTO NORTH FLORIDA THIS WEEKEND. THIS
SHOULD NOT IMPACT THE WEATHER OVER SOUTH FLORIDA FOR SUNDAY AND
MONDAY AS THE HIGH PRESSURE IN THE ATLANTIC IS INTENSIFYING AND
MOVING WESTWARD AT THE SAME TIME.
THE STEERING WINDS WILL REMAIN FROM THE SOUTH AND SOUTHWEST ON
SATURDAY, TRANSITIONING TO THE SOUTHEAST ON SUNDAY AND TURNING
SOUTHEASTERLY FOR THE MOST OF THIS COMING WEEK. A WEAKNESS IN THE
HIGH PRESSURE WILL MOVE FROM EAST TO WEST ON MONDAY OVER THE BAHAMA
ISLANDS. THIS WILL BRING A BRIEF PERIOD OF NORTHEASTERLY WINDS ON
MONDAY MORNING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND EASTERN PORTIONS. FOR
SUNDAY SHOWERS AND THUNDERSTORMS WILL PROBABLY DEVELOP OVER THE
INTERIOR BY MID MORNING AND THEN SHIFT TOWARD THE WEST AS THE DAY
PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW BOUNDARIES COULD
STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO AREAS ON SUNDAY.
FOR MONDAY, THE DEVELOPMENT OF A BRIEF PERIOD OF NORTHEASTERLY WINDS
OVER THE ATLANTIC WATERS AND EASTERN COUNTIES COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS AND ENHANCE MOISTURE
CONVERGENCE IN THE WEST COAST DURING THE AFTERNOON HOURS, POSSIBLY
CONCENTRATING THE SHOWER AND THUNDERSTORM ACTIVITY OVER COLLIER
COUNTY. FOR NEXT WEEK, THE MAIN CONCENTRATION OF SHOWERS AND STORMS
IS FOR THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED AFTER MONDAY.
&&
.AVIATION...
HEAVY SHOWERS WITH SCATTERED THUNDERSTORMS EMBEDDED WILL CONTINUE TO
IMPACT THE EAST COAST TERMINALS THROUGH THE AFTERNOON/EVENING
PERIODS TODAY...MAINLY FROM FLL TO PBI. REDUCED CIGS/VSBYS IN AND
AROUND THIS ACTIVITY WILL REMAIN THE CONCERN THROUGH THIS TIME. THE
LATEST HRRR MODEL REFLECTIVITIES LINE UP WELL WITH THE CURRENT
CONDITIONS AND GENERALLY INDICATE THIS ACTIVITY REMAINING FOCUSED IN
THE BROWARD/PALM BEACH AREAS THROUGH THIS EVENING BEFORE TRENDING
DOWN OVERNIGHT. WINDS WILL REMAIN ONSHORE AT THE SURFACE (SW GULF
COAST AND SE FOR EAST COAST) WITH A OCCASIONAL MODERATE GUSTS
POSSIBLE THROUGH THE AFTERNOON HOURS. ON SUNDAY...CONDITIONS SHOULD
BEGIN TO TREND BACK TO NORMAL AS THE LOW-LEVEL FLOW SHIFTS BACK
TOWARD THE EAST AND HIGH PRESSURE BEGINS TO BUILD BACK OVER THE
AREA. THIS WILL SUPPORT AFTERNOON ACTIVITY SETTING UP INLAND OF THE
EAST COAST TAF SITES AND FARTHER WEST.
&&
.MARINE...
TRANQUIL WIND AND SEAS ARE EXPECTED THROUGH THE PERIOD OUTSIDE OF
ROUGHER SEAS NEAR THUNDERSTORMS. A GENERAL LIGHT TO MODERATE EAST
TO SOUTHEAST WIND IS ANTICIPATED THROUGH THE WEEKEND AND INTO THE
MIDDLE OF NEXT WEEK.
&&
FIRE WEATHER...
NO FIRE WEATHER CONCERNS OR FOG IS ANTICIPATED THIS WEEK. HIGH
RELATIVE HUMIDITY AND AT LEAST SCATTERED SHOWERS WILL PREVAIL. THE
TYPICAL AREA WITH LOWER RELATIVE HUMIDITIES, GLADES AND HENDRY, WILL
MAINTAIN VALUES ABOVE 55 PERCENT THIS WEEKEND AND ABOVE 48 PERCENT
FOR NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 76 88 73 88 / 40 60 20 20
FORT LAUDERDALE 77 88 76 88 / 40 60 30 30
MIAMI 76 89 74 88 / 40 60 30 30
NAPLES 75 87 73 91 / 40 70 40 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...71/JE
AVIATION/RADAR...85/AG
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
157 PM EDT SAT JUL 13 2013
.PREV DISCUSSION...
UPDATE...
/ISSUED 1052 AM EDT SAT JUL 13 2013/
RAIN SO FAR HAS BEEN CONFINED TO EASTERN GA. THINK THE HRRR IS
DECENT IS TERMS OF WHAT IT IS SHOWING FOR TODAY. SHOULD SEE
DEVELOPMENT OF SCATTERED SHOWERS ACROSS THE REMAINDER OF THE CWA
AROUND NOONTIME. CURRENT POP TRENDS LOOK REASONABLE. MAIN CONCERN
WITH THE FORECAST FOR TODAY IS POTENTIAL FOR LOCALIZED FLOODING.
ALTHOUGH OVERALL RAINFALL AMOUNTS ARE EXPECTED TO BE ON THE LOWER
SIDE...LOCALIZED HIGHER AMOUNTS ARE POSSIBLE WITH TRAINING.
ALREADY HAVE LOCALIZED FLOODING ACROSS PARTS OF EASTERN GA...AND
WILL BE INVESTIGATING THIS MORE FOR THE POTENTIAL NEED OF A FLASH
FLOOD WATCH ACROSS EASTERN GA.
11
SHORT TERM /TODAY THROUGH SUNDAY/...
/ISSUED 422 AM EDT SAT JUL 13 2013/
NAM/GFS IN DECENT AGREEMENT WITH MOVING LOW PRESSURE ALOFT OVER THE
OH/TN VALLEY WEST ACROSS THE MS VALLEY THROUGH EARLY SUNDAY WITH
UPPER HIGH PRESSURE BUILDING OVER THE NE STATES LATE TODAY THROUGH
SUNDAY. THIS ALLOWS DEEPER MOISTURE TO MOVE BACK OVER THE AREA FROM
THE SE TODAY AND TONIGHT AND CONTINUE OVER THE AREA FOR SUNDAY.
THE POTENTIAL FOR SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
WILL INCREASE ACROSS THE AREA ESPECIALLY FROM LATE MORNING
ON...INCREASING HIGHEST OVER THE SE 2/3RDS OF THE FORECAST AREA.
THINK CONVECTION WILL BE SLOW TO WIND DOWN OVERNIGHT WITH SOME
CHANCE FOR SHOWERS THROUGHOUT THE LATE NIGHT. NUMEROUS SHOWERS AND
THUNDERSTORMS CAN BE EXPECTED FOR SUNDAY...TENDING TO MAXIMIZE
DURING THE AFTERNOON...AS ABUNDANT MOISTURE AND DECENT INSTABILITY
WILL BE IN PLACE.
MOS POPS FOR N AND PARTS OF CENTRAL GA SEEM TOO LOW FOR TODAY AND
HAVE STAYED CLOSER TO CURRENT FORECAST.
FORECAST HIGH TEMPERATURES RUNNING ABOUT 5-8 DEGREES BELOW NORMAL
TODAY AND SUNDAY. FORECAST LOW TEMPERATURES RUNNING CLOSE TO NORMAL.
OVERALL CONFIDENCE IS MEDIUM TO HIGH.
BDL
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
/ISSUED 422 AM EDT SAT JUL 13 2013/
UPPER LOW MOVING WEST AT THE START OF THE PERIOD WITH STRONG UPPER
RIDGE OVER THE NORTHEAST. TROPICAL MOISTURE STILL BEING DRAWN MOVING
ACROSS THE CWA AT DURING THE FIRST OF THE WEEK. A DEEP EASTERLY
FLOW PATTERN WILL KEEP ATLANTIC MOISTURE OVER THE CWA THROUGH MUCH
OF THE PERIOD. THE FLOW BECOMES MORE SOUTHWESTERLY BY THURSDAY
INTO FRIDAY AS THE UPPER RIDGE WEAKENS A BIT A SHIFTS SOUTHWARD.
IN GENERAL...HAVE BASICALLY KEPT CHANCE POPS EACH DAY WITH SLIGHT
CHANCE OVERNIGHT THROUGH THE PERIOD. A DIURNAL PATTERN SHOULD
BECOME MORE PROMINENT THROUGH THE WEEK...WITH AFTERNOON
TEMPERATURES BECOMING A BIT WARMER.
41
HYDROLOGY...
/ISSUED 422 AM EDT SAT JUL 13 2013/
NO CONFIDENCE FOR A FLASH FLOOD WATCH AT THIS TIME. HOWEVER MOST
THUNDERSTORMS WILL BE ABLE TO PRODUCE HEAVY RAIN AND IF THEY ARE
SLOW MOVERS OR TRAIN OVER THE SAME AREA...LOCALIZED FLASH FLOODING
WILL BE POSSIBLE. AVERAGE RAINFALL AMOUNTS THE NEXT COUPLE DAYS WILL
BE 1 INCH OR LESS.
&&
.AVIATION...
18Z UPDATE...
SHRA/TSRA ACROSS EAST CENTRAL GEORGIA CONTINUES TO SPREAD TO THE
NORTH AND WEST. SHOULD SEE CONVECTION NEAR THE ATL TAF SITES BY
LATE AFTERNOON. THERE IS THE POTENTIAL FOR TSRA TO LAST LONGER
THAN 00Z TONIGHT...BUT SHOULD EVENTUALLY TRANSITION TO JUST SHRA. A
LOT OF UNCERTAINTY WHETHER THE SHRA WILL LAST ALL NIGHT...BUT
THINKING IS THAT IF IT DOES LAST OVERNIGHT...IT WILL GENERALLY BE
NORTH OF THE TAF SITES.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE IS MEDIUM ON TIMING OF TSRA...CIGS AND VSBYS. HIGH
CONFIDENCE ON WIND.
11
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 83 69 84 70 / 60 60 70 20
ATLANTA 84 70 83 70 / 50 50 70 30
BLAIRSVILLE 81 67 81 65 / 50 50 70 20
CARTERSVILLE 86 69 85 70 / 50 50 70 30
COLUMBUS 85 72 87 73 / 50 50 70 40
GAINESVILLE 81 70 82 70 / 60 60 70 20
MACON 85 70 88 70 / 60 50 70 30
ROME 87 70 86 70 / 40 40 70 40
PEACHTREE CITY 84 70 84 69 / 50 50 70 40
VIDALIA 84 71 88 72 / 70 50 60 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BIBB...BLECKLEY...CLARKE...CRISP...
DODGE...DOOLY...EMANUEL...GLASCOCK...GREENE...HALL...HANCOCK...
HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...
LAURENS...MADISON...MONTGOMERY...MORGAN...OCONEE...OGLETHORPE...
PULASKI...PUTNAM...TALIAFERRO...TELFAIR...TOOMBS...TOWNS...
TREUTLEN...TWIGGS...WALTON...WARREN...WASHINGTON...WHEELER...
WHITE...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...11
LONG TERM....ARG
AVIATION...11
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
602 PM CDT SAT JUL 13 2013
.DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 00Z...
* NONE
IZZI
//DISCUSSION...UPDATED 00Z...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. LAKE BREEZE WILL
DEVELOP AND MOVE THRU THE CHICAGO TERMINALS AGAIN SUNDAY AFTERNOON
WITH WINDS TURNING EAST AND PICKING UP TO AROUND 10KT WITH OCNL
GUSTS TO 15KT IN THE AFTERNOON. SURFACE MOISTURE HAS BEEN SLOW TO
INCREASE...SO THINK ANY HAZE/LIGHT FOG WILL BE CONFINED TO MORE
RURAL AREAS SUNDAY MORNING.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 00Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 12Z MONDAY-12Z SATURDAY...UPDATED 00Z...
MONDAY THROUGH THURSDAY...GENERALLY PREVAILING VFR...HOWEVER AN
AFTERNOON THUNDERSTORM CANNOT BE COMPLETELY RULED OUT ANY DAY.
FRIDAY...CHANCE OF THUNDERSTORMS.
IZZI
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
455 PM CDT SAT JUL 13 2013
.DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* NONE
IZZI
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE RIDGE BECOMING ELONGATED NE-SW ACROSS LAKE
MICHIGAN EXTENDING INTO NE ILLINOIS WILL REMAIN ACROSS THE AREA
THIS AFTERNOON. EXPECT VARIABLE WIND SPEEDS WITH AN E-NE WIND DIRECTION
THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING AT ORD/MDW
BEHIND WEAK SYNOPTICALLY ENHANCED LAKE BREEZE.
INCREASING MOISTURE FROM THE EAST TONIGHT RESULTING IN INCREASING
SFC DEW POINTS COMBINED WITH SOMEWHAT STAGNATING AIR UNDER THE HIGH
PRESSURE RIDGE AND WEAK GRADIENT SHOULD SET THE STAGE FOR A BRIEF
PERIOD OF MVFR (4-5 SM) VISIBILITY AROUND AND SHORTLY AFTER
SUNRISE SUNDAY MORNING. MAY ALSO SEE A PERIOD OF PATCHY 3500 FOOT
CLOUD DECK OVERNIGHT WITH INCREASED MOISTURE.
WITH WEATHER PATTERN GENERALLY LITTLE CHANGED SUNDAY... EXPECT
SOMEWHAT OF A REPEAT OF WIND CHARACTERISTICS FROM TODAY... WITH A
WEAK MIDDAY/EARLY AFTERNOON LAKE BREEZE IMPACTING BOTH AIRPORTS
CAUSING TURNING OF WINDS FROM SE TO MORE E TO E-NE.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH FRIDAY...VFR. VERY SLIGHT CHANCE OF AN
ISOLATED AFTERNOON TSRA EACH DAY.
RATZER
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
255 PM CDT SAT JUL 13 2013
.DISCUSSION...
255 PM...MAIN FORECAST CONCERNS/CHALLENGES REMAIN RETURNING HEAT/
HUMIDITY AND CHANCES FOR PRIMARILY AFTERNOON THUNDERSTORMS.
IN THE SHORT TERM...AN UPPER LOW CONTINUES TO MOVE WEST ACROSS
THE OHIO VALLEY WITH THE BULK OF THE PRECIP ASSOCIATED WITH THIS
FEATURE WELL SOUTHEAST OF THE AREA AND EXPECT ANY PRECIP THAT
DOES DEVELOP ON THE NORTHERN SIDE OF THIS UPPER LOW TO REMAIN
SOUTH OF THE AREA TONIGHT. THIS ALSO PREVENTED THE CIRRUS FROM
EARLIER CONVECTION TO THE NORTHWEST FROM SPREADING ACROSS THE
AREA. WITH MOSTLY SUNNY SKIES...TEMPS HAVE CLIMBED INTO THE LOWER/
MID 80S...A LITTLE COOLER NEAR THE LAKE. DEWPOINTS DID DROP
DIURNALLY INTO THE 50S AND WILL TOUCH ON DEWPOINTS AGAIN FOR NEXT
WEEK. HOWEVER WITH LOW LEVEL MOISTURE GRADUALLY INCREASING...
APPEARS LOWS TONIGHT WILL ONLY DROP INTO THE LOWER/MID 60S AND
PROBABLY AROUND 70 IN CHICAGO.
A LARGE AREA OF HIGH PRESSURE EXTENDS FROM THE GREAT LAKES EAST
TO THE ATLANTIC AND THIS RIDGE WILL MOVE BACK WEST OVER THE NEXT
FEW DAYS...EVENTUALLY BECOMING CENTERED OVER THE OHIO VALLEY AND
SOUTHERN GREAT LAKES TUESDAY AND PERHAPS SLOWLY DRIFT SOUTH INTO
WEDNESDAY AND THURSDAY. THIS WILL CONTINUE TO ALLOW GENERALLY
LIGHT EASTERLY WINDS AND POTENTIAL LAKE BREEZES THROUGH TUESDAY
AFTERNOON...KEEPING THE LAKE SHORE AREAS A LITTLE COOLER. AND
WHILE THERE ARE NO SIGNIFICANT WAVES EXPECTED TO AFFECT THE
AREA...THE FORECAST SOUNDINGS DON/T SHOW MUCH CAPPING AND THUS
AS THE LOW LEVELS CONTINUE TO MOISTEN UP...ISOLATED THUNDERSTORMS
WILL REMAIN POSSIBLE MAINLY DURING THE AFTERNOON/EARLY EVENING
HOURS AND HAVE MAINTAINED SLIGHT CHANCE POPS MONDAY THROUGH
THURSDAY. HOWEVER...ITS POSSIBLE ISOLATED ACTIVITY COULD DEVELOP
SUNDAY AFTERNOON. IN ADDITION...AS THE HIGH NOW APPEARS TO DRIFT
SOUTH WEDNESDAY INTO THURSDAY...THERE IS INCREASING CONFIDENCE
THAT WINDS WILL TURN MORE WESTERLY DURING THIS TIME ALLOWING
WARMER AIR TO ADVECT INTO THE REGION WHICH WOULD LIKELY PROVIDE
ENOUGH CAPPING TO PREVENT CONVECTION. THUS WEDNESDAY AND THURSDAY
COULD END UP BEING DRY. A STRONG COLD FRONT IS STILL EXPECTED TO
MOVE SOUTH ACROSS THE REGION FRIDAY INTO FRIDAY NIGHT WITH THE GFS
FASTER THAN THE GEM/ECMWF. A SLOWER FRONTAL ARRIVAL WILL NOT JUST
DELAY PRECIP/POPS BUT ALSO COULD ALLOW FOR ANOTHER HOT/HUMID DAY
ON FRIDAY.
AS FOR TEMPS/DEWPOINTS...THERE REMAINS SEVERAL VARIABLES BUT
CONFIDENCE IS INCREASING. DEWPOINTS ARE EXPECTED TO SURGE BACK
INTO THE 70S BY MONDAY AND LIKELY REMAIN IN THE 70S UNTIL THE
FRONT ARRIVES FRIDAY/FRIDAY NIGHT. BUT AS SEEN OVER THE PAST
SEVERAL DAYS...DEWPOINTS CONTINUE TO MIX OUT OVER THE MORE URBAN
AREAS OF NORTHEAST IL AND LONGER TERM GUIDANCE HASN/T BEEN
HANDLING THIS TOO WELL...WHILE THE HIS RES HRRR HAS BEEN DOING
FAIRLY WELL THE PAST 2 DAYS. HAVE LOWERED DEWPOINTS INTO THE UPPER
60S DURING THE AFTERNOON ACROSS THE HEART OF THE METRO AREA BUT
CONFIDENCE REGARDING SPECIFIC TRENDS REMAINS LOW. BY WEDNESDAY AND
ESPECIALLY ON THURSDAY...EXPECT A LITTLE BIT MORE WESTERLY WINDS
AND DEEPER MIXING BUT MUCH OF THE LOW LEVELS REMAIN MOIST THUS
ITS POSSIBLE DEWPOINTS COULD HANG ON IN THE 70S EVERYWHERE. THESE
WILL BE KEY TO HEAT INDICES NOW THAT HIGH TEMPS IN THE LOWER 90S
LOOK REASONABLE AND HAVE BUMPED HIGH TEMPS UP A FEW DEGREES
MID/LATE WEEK. 12Z GEM/ECMWF ARE NOW IN THE +21C RANGE FOR 850MB
TEMPS THURSDAY WITH THE GFS SLIGHTLY COOLER BUT TRENDING WARMER
FROM PREVIOUS RUNS. ONLY HAVE HIGHS IN THE 92-93 RANGE BUT
DEPENDING ON HOW HIGH THE DEWPOINTS STAY...DEPTH OF MIXING AS
WELL AS CLOUD COVER...HIGHS ON THURSDAY COULD EASILY BE IN THE
MID 90S. AND DESPITE THE CONTINUED UNCERTAINTY REGARDING SPECIFIC
TEMPS/DEWPOINTS...EXPECT HEAT INDICES IN THE UPPER 90S/NEAR 100
ON TUESDAY AND THEN AROUND 100 FOR WEDNESDAY/THURSDAY.
WHILE ADVERTISED HIGHS ON FRIDAY ARE ONLY IN THE UPPER 80S DUE TO
THE UNCERTAINTY OF THE FRONTAL SPEED/TIMING...IF THE FRONT HOLDS
OFF UNTIL FRIDAY AFTERNOON OR EVENING...HIGHS COULD EASILY BE IN
THE LOWER/MID 90S AGAIN FRIDAY AND WHILE LOWS EVERY NIGHT WILL
LIKELY BE IN THE LOWER/MID 70S...THURSDAY NIGHT INTO FRIDAY
MORNING COULD BE PARTICULARLY WARM WITH LOWS MAYBE ONLY IN THE MID
TO UPPER 70S WITH PERHAPS ONLY 80 DOWNTOWN CHICAGO. BUT AS
MENTIONED ABOVE WHILE CONFIDENCE IS INCREASING WITH THE OVERALL
PATTERN/TRENDS...THIS IS STILL SEVERAL DAYS AWAY. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* VARYING WIND SPEEDS THIS AFTERNOON/OCCASIONAL GUSTINESS
* BRIEF REDUCTION IN VSBY AROUND-SHORTLY AFTER SUNRISE SUNDAY IN HAZE
ED F
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE RIDGE BECOMING ELONGATED NE-SW ACROSS LAKE
MICHIGAN EXTENDING INTO NE ILLINOIS WILL REMAIN ACROSS THE AREA
THIS AFTERNOON. EXPECT VARIABLE WIND SPEEDS WITH AN E-NE WIND DIRECTION
THE REMAINDER OF THE AFTERNOON AND INTO THE EVENING AT ORD/MDW
BEHIND WEAK SYNOPTICALLY ENHANCED LAKE BREEZE.
INCREASING MOISTURE FROM THE EAST TONIGHT RESULTING IN INCREASING
SFC DEW POINTS COMBINED WITH SOMEWHAT STAGNATING AIR UNDER THE HIGH
PRESSURE RIDGE AND WEAK GRADIENT SHOULD SET THE STAGE FOR A BRIEF
PERIOD OF MVFR (4-5 SM) VISIBILITY AROUND AND SHORTLY AFTER
SUNRISE SUNDAY MORNING. MAY ALSO SEE A PERIOD OF PATCHY 3500 FOOT
CLOUD DECK OVERNIGHT WITH INCREASED MOISTURE.
WITH WEATHER PATTERN GENERALLY LITTLE CHANGED SUNDAY... EXPECT
SOMEWHAT OF A REPEAT OF WIND CHARACTERISTICS FROM TODAY... WITH A
WEAK MIDDAY/EARLY AFTERNOON LAKE BREEZE IMPACTING BOTH AIRPORTS
CAUSING TURNING OF WINDS FROM SE TO MORE E TO E-NE.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN FORECAST OF HAZE AND TIMING OF LAKE BREEZE
ON SUNDAY.
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT THROUGH FRIDAY...VFR. VERY SLIGHT CHANCE OF AN
ISOLATED AFTERNOON TSRA EACH DAY.
RATZER
&&
.MARINE...
155 PM CDT
A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DOMINATE ACROSS MUCH
OF THE GREAT LAKES. THIS HAS SET UP A FLOW PATTERN DRIVEN MAINLY BY
A LAKE BREEZE ACROSS THE SOUTHERN HALF OF THE LAKE...WHICH HAS
RESULTED IN LIGHT BUT ONSHORE FLOW. MEANWHILE FARTHER NORTH...A
SLIGHTLY BETTER GRADIENT ALONG THE NORTHWESTERN PERIPHERY OF THE
SURFACE RIDGE CONTINUES TO DRIVE SOUTHERLY WINDS UP TO 15 KT. THIS
GENERAL PATTERN WILL BE THE RULE DURING THE DAYTIME AGAIN ON SUNDAY
AND INTO MONDAY AS THE HIGH PRESSURE RIDGE CONTINUES TO INFLUENCE
THE LAKE.
THE FLOW SHOULD GRADUALLY BECOME MORE SOUTHWEST BY THE MIDDLE OF
NEXT WEEK AS THE SURFACE HIGH SHIFTS TO THE SOUTH AND WEST ACROSS
THE MID MISSISSIPPI AND OHIO VALLEYS AS A COUPLE OF LOWS TRACK
EASTWARD ACROSS ONTARIO. LATER NEXT WEEK...IT APPEARS THAT THE
WEATHER COULD BECOME ACTIVE ACROSS THE LAKE AS A COLD FRONT LOOKS TO
SHIFT SOUTHWARD DOWN THE LAKE. THIS COULD RESULT IN VERY GOOD
CHANCES FOR SHOWERS AND THUNDERSTORMS LATER NEXT WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 PM MDT SAT JUL 13 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 595DM RIDGE CENTERED OVER
TX/OK PANHANDLES WITH AXIS EXTENDING INTO THE NORTHERN PLAINS. A
CLOSED 578DM LOW OVER THE EASTERN OH RIVER VALLEY IS JUST DOWN
STREAM OF THIS FEATURE...WITH THE REMNANTS OF OVERNIGHT CONVECTION
IN THE NORTHERN PLAINS BEGINNING TO BECOME WRAPPED INTO THE FLOW
BETWEEN THESE FEATURES. A SHORTWAVE TROUGH IS CURRENTLY IN PLACE
OVER NE COLORADO...WITH THUNDERSTORMS ALREADY BEGINNING TO DEVELOP
OVER HIGHER TERRAIN IN ON WESTERN EXTENT OF THIS FEATURE. A SURFACE
TROUGH IS CURRENTLY CENTERED OVER THE NE PART OF OUR CWA AND EXTENDS
SOUTH AND WEST INTO SOUTHEAST COLORADO.
TD VALUES HAVE MIXED DOWN OVER EASTERN PARTS OF THE CWA...RESULTING
IN SLIGHTLY LOWER HEAT INDICES THAN ORIGINALLY ANTICIPATED. AT THE
SAME TIME CRITERIA IS BEING MET AT NORTON...AND WE HAVENT REACHED
PEAK HEATING YET...SO WILL PLAN ON LEAVING HEAT ADVISORY AS IS.
GUIDANCE CONTINUES TO SUPPORT THUNDERSTORMS INITIATING ALONG AND
BEHIND THE SURFACE TROUGH OVER OUR CWA...WITH BETTER COVERAGE CLOSER
TO H7/H5 SHORTWAVE TROUGH IN NORTHEAST COLORADO. LATEST RAP ANALYSIS
SHOWS AXIS OF 1500-2000 J/KG ML CAPE EXTENDING ACROSS CWA. SHEAR ISNT
VERY IMPRESSIVE...BUT WITH INVERTED V AND GOOD MOISTURE ABOVE DRY
LAYER STRONG GUSTS WILL BE A CONCERN WITH ANY THUNDERSTORMS.
GUIDANCE ACTUALLY SHOWS ACTIVITY CONTINUE THROUGH MOST OF THE
NIGHT...HOWEVER WITH SHORTWAVE WEAKENING AND MOVING NORTH AND EAST
IM LESS CONFIDENT IN THIS ACTIVITY LINGERING PAST 06Z.
CLOSED LOW OVER OH RIVER VALLEY WITH MOVE EAST INTO THE SOUTHERN
PLAINS SUNDAY WITH DEEP EASTERLY FLOW DEVELOPING ACROSS THE
CWA...AND COLD FRONT MOVING INTO THE REGION FROM THE SOUTHEAST LATE
IN THE AFTERNOON. BEST CONVERGENCE/LARGE SCALE ASCENT WILL LIKELY BE
ALONG FRONT RANGE EXTENDING INTO OUR EASTERN CO COUNTIES WHERE AXIS
OF STRONG VORTICITY ON NW QUAD OF UPPER LOW WILL COMBINE WITH STRONG
UPSLOPE TO PRODUCE SHOWERS AND THUNDERSTORMS. GUIDANCE CONTINUES TO
SHOW DECENT INSTABILITY IN PLACE...AND WITH PWATS IN EXCESS OF 1.5
INCHES WE COULD SEE NUMEROUS THUNDERSTORMS WITH HEAVY RAIN. I
TRENDED POPS UP DURING THE AFTERNOON TO LIKELY CATEGORY DURING
AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 216 PM MDT SAT JUL 13 2013
SUNDAY EVENING THE FRONT WILL CONTINUE TO MOVE WEST...WITH THE
BEST INSTABILITY AND LIFT REMAINING OVER THE TROUGH. WITH LITTLE
CIHN TO HOLD BACK CONVECTION AND SURFACE CONVERGENCE SERVING AS A
TRIGGER...STORMS SHOULD NOT HAVE MUCH PROBLEM DEVELOPING. THE BEST
CHANCE FOR STORM DEVELOPMENT WILL BE OVER THE EAST CENTRAL
COLORADO AND PARTS OF FAR SOUTHWEST NEBRASKA WITH PRECIP. CHANCES
DECLINING TO THE EAST AS LIFT AND INSTABILITY TAPER OFF. AS THE
EVENING PROGRESSES THE SURFACE TROUGH WILL GRADUALLY MOVE WEST OUT
OF THE AREA...WITH BE BETTER PRECIP. CHANCES FOLLOWING IT.
MEANWHILE DRIER MORE STABLE AIR WILL BE MOVING IN FROM THE EAST
ACCOMPANYING AN INVERTED SURFACE RIDGE. THE DRIER AIR WILL HAVE
MOVED ACROSS ENTIRE AREA BY LATE IN THE NIGHT.
STRONG THUNDERSTORMS WILL BE POSSIBLE OVER THE NORTHWEST PART OF
THE AREA NEAR THE SURFACE TROUGH WHERE A CORRIDOR OF MIXED 1KM MOST
UNSTABLE CAPE IN EXCESS OF 2000J/KG WILL BE LOCATED. THE LIMITING
FACTOR WILL BE THE LOW 0-6KM SHEAR OF 15-20KTS...WHICH MAY BE
ENOUGH FOR AN ISOLATED SUPERCELL TO DEVELOP GIVEN THE ADEQUATE CAPE.
MEAN STORM MOTIONS WILL BE TO THE SOUTHEAST OVER EAST CENTRAL
COLORADO...SO THERE MAY BE SOME TRAINING ALONG THE SURFACE TROUGH
LEADING TO LOCALLY HEAVY RAINFALL IN THE EVENING.
MONDAY THE SURFACE RIDGE SLIDES SOUTH AS ANOTHER WAVE OF MOISTURE
MOVES OVER THE SOUTHERN HALF OF THE AREA AROUND THE UPPER LEVEL LOW
TO THE SOUTH DURING THE AFTERNOON. TOWARD LATE AFTERNOON A WAVE OF WEAK
LIFT DEVELOPS OVER THE FAR SOUTHERN PART OF THE AREA...THEN
DISSIPATES BY EARLY EVENING. THIS MAY BE ENOUGH LIFT FOR AN
ISOLATED STORM TO DEVELOP.
TUESDAY THROUGH SATURDAY WILL BE DRY FOR THE MAJORITY OF THE PERIOD
AS THE UPPER LEVEL RIDGE OVER THE EAST CONUS BUILDS WEST AND BECOMES
ESTABLISHED OVER THE WESTERN CONUS TOWARD THE END OF THE WORK WEEK.
DURING THE WEEKEND AN UPPER LEVEL SHORT WAVE TROUGH DEVELOPS OVER
THE NORTHERN ROCKIES AND MOVES SOUTHEAST OVER THE AREA. A COLD
FRONT WILL ACCOMPANY THE UPPER LEVEL FEATURE WHICH WILL AID THE LIFT
OF THE TROUGH. BEING A WEEK OUT THERE IS STILL A GOOD DEAL OF
UNCERTAINTY AS TO WHERE THE TROUGH WILL TRACK AND IF IT WILL BE DEEP
ENOUGH TO DEVELOP STORMS. WOULD NOT TAKE TOO MUCH OF A SHIFT IN THE
POSITION OF THE RIDGE OVER THE ROCKIES TO PUSH THE UPPER LEVEL
TROUGH NORTH OF THE AREA. AS SUCH WILL LEAVE PRECIP. CHANCES JUST
BELOW 50% FOR THE ENTIRE AREA FOR SATURDAY. HIGH TEMPERATURES FOR
THE PERIOD WILL GRADUALLY WARM AS THE RIDGE BUILDS EAST. NEAR
NORMAL VALUES THROUGH MID WEEK WILL WARM TO ABOVE NORMAL BY FRIDAY
WITH HIGHS RANGING FROM BELOW TO ABOVE NORMAL SATURDAY AS THE COLD
FRONT MOVES THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1130 AM MDT SAT JUL 13 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD AT BOTH KGLD
AND KMCK TERMINALS. WITH SURFACE TROUGH AXIS NEAR BOTH TERMINALS
WINDS WILL GENERALLY BE LIGHT AND VARIABLE...THOUGH THERE WILL BE
A PERIOD WHEN THEY ARE LIKELY TO SHIFT TO THE SOUTH-SOUTHEAST AND
INCREASE TO NEAR 12KT THIS AFTERNOON. ISOLATED TO SCATTERED
THUNDERSTORMS ARE EXPECTED TO DEVELOP THIS AFTERNOON AND CONTINUE
THROUGH TONIGHT. MAIN FOCUS SHOULD BE EAST OF BOTH
TERMINALS...THOUGH WITH SURFACE TROUGH NEARBY I CANT RULE OUT
ACTIVITY OVER EITHER TERMINAL. COVERAGE IS STILL TOO MUCH OF A
QUESTION TO ADD TO TAFS AT THIS TIME...SO I WILL KEEP MENTION OUT
FOR NOW.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR KSZ002>004-016.
CO...NONE.
NE...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR NEZ080-081.
&&
$$
SHORT TERM...DJR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1221 PM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CDT SAT JUL 13 2013
THE ELONGATED MID LEVEL RIDGE OBSERVED ON WATER VAPOR IMAGERY AT 08Z
SHOWS THE AXIS STRETCHED FROM NORTHERN MEXICO NORTHEASTWARD THROUGH
THE PLAINS TOWARDS THE GREAT LAKES REGION. CLOSED UPPER TROUGH OVER
THE OHIO VALLEY CONTINUES TO TRACK WESTWARD TOWARDS THE MISSISSIPPI
VALLEY WHILE MINOR EMBEDDED SHORTWAVE TROUGHS WITHIN THE RIDGE ARE
TRIGGERING CONVECTION OVER SOUTH DAKOTA INTO MINNESOTA.
CLOSER TO THE SURFACE...THE LATEST RUNS OF THE NAM12 AND RAP HAVE
SHOWN INCREASING YET WEAK ISENTROPIC LIFT ON THE 315K SURFACE WITH
WEAK MIXED LAYER CAPE NEAR 500 J/KG. THIS HAS HELPED SPARK A FEW
ISOLATED SHOWERS ACROSS PORTIONS OF NORTHEAST KANSAS THIS MORNING.
EXPECT THESE SHOWERS AND ISOLATED THUNDER TO PERSIST THROUGH THE
MORNING AND PERHAPS SATURDAY AFTERNOON HOURS FOR MUCH OF THE AREA.
UNCERTAINTY EXISTS AS TO IF THE PRECIP CAN MAINTAIN ITSELF ON
SATURDAY AFTERNOON. THE GFS/NAM/RAP/HRRR SHOW SPOTTY SHOWERS AND
THUNDERSTORMS LINGERING AS A WEAK EMBEDDED SHORTWAVE AND VORT MAX
ROTATES THROUGH NORTHERN KS WHILE THE WEAK ISENTROPIC LIFT PERSISTS
THROUGH 21Z. ON THE OTHER HAND...THESE MODELS HAVE BEEN POOR
HANDLING THE WEAK FEATURES AND EXAGGERATING PRECIP CHANCES. BELIEVE
ENOUGH CONSISTENCY BETWEEN THE MODELS AND SIGNALS OF WEAK THE
INSTABILITY AND LIFT WILL WARRANT SLIGHT CHC MENTION THROUGH 21Z
TODAY.
THE ABOVE MENTIONED CLOSED TROUGH IS PROGGED SHIFT INTO MISSOURI ON
SATURDAY EVENING. MID LEVEL MOISTURE AND HENCE CLOUD COVER WILL
INCREASE IN ADVANCE OF ITS ARRIVAL. SHOWERS AND THUNDERSTORMS
ARE ONCE AGAIN POSSIBLE AS THE TROUGH EDGES CLOSER TO THE CWA.
TIMING OF THIS TROUGH AND ASSOCIATED PRECIP IS STILL SOMEWHAT
UNCERTAIN AS THE LATEST RUN SHOWS THE NAM AND ECMWF SLOWER THAN THE
GFS. TAKING ALSO INTO ACCOUNT CONSISTENCY WITH PREVIOUS DAYS HAVE
KEPT SLIGHT CHANCES BEGINNING AT 00Z AND RAISING THE LIKELIHOOD WITH
THE INCREASING LIFT OVERNIGHT. EXPECT THE STORMS TO BE ELEVATED IN
NATURE WITH SEVERE WEATHER NOT EXPECTED.
LOOKING AT TEMPERATURES...SHOULD EXPECT A SIMILAR SATURDAY AFTERNOON
IN TERMS OF WARMTH WITH HIGHS GENERALLY IN THE LOW 90S FOR EAST
CENTRAL AND NORTHEAST AREAS...TO THE UPPER 90S OVER NORTH CENTRAL
KS. H85 MOISTURE AXIS CENTERS OVER THE AREA WITH INCREASING
DEWPOINTS IN THE MID TO UPPER 60S. HEAT INDEX READINGS THEREFORE
SHOULD MAX OUT IN THE LOW 100S OVER NORTH CENTRAL AREAS. OVERNIGHT
INCREASING CLOUDS...SCT PRECIP AND WEAKER TEMP ADVECTION SHOULD COOL
LOWS SLIGHTLY IN THE UPPER 60S.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 339 AM CDT SAT JUL 13 2013
FOR SUNDAY...THE MODELS ARE IN GOOD AGREEMENT WITH THE CLOSED LOW
MOVING ACROSS SOUTHEAST KS INTO CENTRAL OK. THERE APPEARS TO BE
SOME DECENT MID LEVEL FRONTOGENESIS AND CONVERGENCE ALONG THE
LEADING EDGE OF THE LOW PRESSURE SYSTEM. WITH MOST MODELS
DEVELOPING A BAND OF QPF ACROSS CENTRAL KS...HAVE INCREASED POPS
DURING THE MORNING WHILE THE MESOSCALE FORCING IS ANTICIPATED.
INITIAL CLOUD COVER AND COOLER 850 TEMPS WITH SOME COLD AIR
ADVECTION IS EXPECTED TO KEEP HIGHS IN THE MID AND UPPER 80S.
FOR SUNDAY NIGHT THROUGH WEDNESDAY...THE MID LEVEL RIDGING IS
EXPECTED TO NOSE INTO EASTERN KS FROM THE EAST AS THE UPPER LOW
CONTINUES TO RETROGRADE WEST. AM NOT ALL THAT EXCITED ABOUT
CHANCES FOR PRECIP THROUGH THE PERIOD SINCE THERE IS NO OBVIOUS
FORCING OR LIFTING MECHANISM. HOWEVER FORECAST SOUNDINGS FROM THE
GFS SHOW THERE IS LITTLE TO NO CONVECTIVE INHIBITION FOR
MONDAY...TUESDAY OR WEDNESDAY. THEREFORE CANNOT RULE OUT PRECIP
ALL TOGETHER. WOULD ANTICIPATE ANY STORMS TO BE ISOLATED SO HAVE
KEPT DAYTIME POPS AT 20 PERCENT. THERE DOES NOT APPEAR TO BE A
GREAT DEAL OF WARM AIR ADVECTION THROUGH THE PERIOD...SO TEMPS ARE
FORECAST TO SHOW A VERY GRADUAL WARMING TREND AS THROUGH
WEDNESDAY.
THURSDAY AND FRIDAY SHOULD CONTINUE TO SEE THE WARMING TREND AS
THE THERMAL RIDGE BEGINS TO MOVE INTO THE PLAINS. LOWS SHOULD
AGAIN BE IN THE MID 70S WITH HIGHS IN THE LOWER TO MID 90S.
OTHERWISE RIDGING ALOFT SHOULD KEEP PRECIP CHANCES AROUND 10
PERCENT...AND WILL CONTINUE WITH A DRY FORECAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1220 PM CDT SAT JUL 13 2013
FOR THE 18Z TAFS...VFR CONDITIONS EXPECTED THROUGH THE PERIOD.
MID-LEVEL CLOUDS WILL LINGER OVER THE REGION TODAY WITH LIGHT 5-10KT
SOUTHEASTERLY WINDS. THERE IS A SLIGHT CHANCE FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP OVERNIGHT INTO SUNDAY MORNING.
HOWEVER...CONFIDENCE IN THE EXACT TIMING AND TRACKING OF THE
PRECIPITATION IS STILL LOW. MODELS ARE IN AGREEMENT THAT PRECIP
CHANCES LOOK TO BE HIGHER NEAR KMHK SO HAVE A MENTION OF VCTS FOR A
FEW HOURS SUNDAY MORNING. HAVE KEPT KTOP AND KFOE DRY THROUGH THE
PERIOD DUE TO THE LOWER CONFIDENCE BUT WILL CONTINUE TO MONITOR WITH
FUTURE UPDATES. WINDS BY SUNDAY WILL REMAIN LIGHT...BACKING MORE
TOWARD THE EAST SOUTHEAST.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BOWEN
LONG TERM...WOLTERS
AVIATION...HENNECKE
AREA FORECAST DISCUSSION
NWS JACKSON KY
214 PM EDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 1102 AM EDT SAT JUL 13 2013
FRESHENED UP THE GRIDS ACCORDING TO THE LATEST RADAR AND OBSERVATION
TRENDS. CONVECTION IS TRYING TO WIND DOWN...ALTHOUGH A FEW CLUSTERS
REMAIN ACROSS PORTIONS OF THE AREA. STILL EXPECT A GENERAL DOWNWARD
TREND IN THE AREAL COVERAGE THROUGH THE AFTERNOON AS THE UPPER LEVEL LOW
GRADUALLY EXITS WEST AND HEIGHTS RECOVER.
UPDATE ISSUED AT 835 AM EDT SAT JUL 13 2013
CONVECTION CONTINUES TO BLOSSOM AROUND A VORT LOBE ROTATING AROUND
THE UPPER LEVEL LOW...WHICH IS STARTING TO MAKE ITS WESTWARD MOVEMENT
NOW. HAVE UPDATED FOR AN INCREASE IN POPS BASED ON THE LATEST RADAR
TRENDS. CONVECTIVE COVERAGE SHOULD DECREASE THIS AFTERNOON AS THE
UPPER LOW PULLS WEST AND HEIGHTS RECOVER.
UPDATE ISSUED AT 625 AM EDT SAT JUL 13 2013
SOME ELEVATED CONVECTION HAS FIRED UP ACROSS PORTIONS OF THE AREA FOR
THE PAST HOUR ASSOCIATED WITH SOME MOISTURE CONVERGENCE INDUCED BY
THE UPPER LEVEL LOW. LATEST HRRR MODEL AND NAM12 SUPPORT SCATTERED
ACTIVITY THROUGH THE MORNING. WILL INCLUDE CHANCE POPS THROUGH THE
MID-MORNING HOURS BASED ON THE LATEST RADAR TRENDS AND MODEL
GUIDANCE...BEFORE BLENDING IN WITH THE EXISTING FORECAST FOR THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 352 AM EDT SAT JUL 13 2013
AN AREA OF SURFACE HIGH PRESSURE REMAINS ANCHORED FROM NEW ENGLAND
THROUGH THE GREAT LAKES. THIS HAS PROVIDED A NICE REPRIEVE FROM THE
HUMIDITY ACROSS EASTERN KENTUCKY AS TEMPERATURES HAVE SLIPPED INTO
THE UPPER 50S AND LOWER 60S. MEANWHILE...AN UPPER LEVEL LOW IS
CURRENTLY SPINNING ITS WHEELS ACROSS NORTHEASTERN KENTUCKY...MAINLY
SPREADING SOME AREAS OF MID AND HIGH LEVEL CLOUD COVER ACROSS THE
AREA.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM...GRADUALLY
SHIFTING THE UPPER LEVEL LOW WESTWARD...WHILE AN UPPER LEVEL HIGH
PRESSURE RIDGE RAMPS UP ACROSS NEW ENGLAND AND EVENTUALLY INTO THE
OHIO VALLEY. AS THE UPPER LOW SHIFTS WEST TODAY...ISOLATED TO
SCATTERED CONVECTION WILL BE POSSIBLE ACROSS THE AREA...WITH MOST
MODELS SHOWING SLIGHTLY BETTER COVERAGE IN THE WESTERN HALF OF THE
AREA. WHILE LAPSE RATES WILL NOT BE AS STEEP COMPARED TO
YESTERDAY...LINGERING MID-LEVEL DRY AIR WILL ALLOW FOR THE POTENTIAL
FOR A FEW STRONG STORMS. HIGHS TODAY WILL REACH INTO THE MID
80S...WITH DEW POINTS UP A FEW MORE DEGREES AS WELL.
CONVECTION WILL DIE OFF QUICKLY EARLY THIS EVENING...BETWEEN THE LOSS
OF HEATING AND HEIGHTS REBOUNDING AS THE UPPER LOW PULLS AWAY. LOWS
WILL GET DOWN INTO THE LOW TO MID 60S...WITH SOME PATCHY FOG ALONG
THE RIVER VALLEYS. ON SUNDAY...HIGHS WILL RETURN TO THE UPPER 80S FOR
MOST LOCATIONS...WITH THE THREAT OF AT LEAST SOME ISOLATED
CONVECTION ONCE AGAIN.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 213 PM EDT SAT JUL 13 2013
THE MID LEVEL LOW PRESSURE WILL FINALLY HAVE DRIFTED TO THE SRN
PLAINS AND BE REPLACED BY HIGH PRESSURE AT BOTH THE SFC AND ALOFT.
THIS WILL PRODUCE A COUPLE DAYS OF FAIR WEATHER WITH LITTLE TO NO
RAIN EXPECTED. THE HUMIDITY WILL REMAIN HIGH AND A RANDOM AFTERNOON
SHOWER OR THUNDERSTORM CAN NOT BE RULED OUT...BUT NOT ENOUGH TO PUT
POPS INTO THE FCST. BY WED AFTERNOON...EVEN THOUGH THE HIGH PRESSURE
REMAINS IN CONTROL THE SFC HAS HAD ENUF TIME TO DIRTY UP WITH THE
HUMIDITY AND SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS WILL BE PRESENT FOR THE REMAINDER OF THE WORK WEEK.
THEN ON SAT A 50H LOW WILL DROP FROM CNTRL CANADA TO JUST SOUTH OF
HUDSON BAY. WITH THE SFC LOW DROPPING TO NRN MAINE AND A COLD FRONT
STRETCHING ACROSS THE GREAT LAKES TO THE CNTRL PLAINS BECOMING A
FOCUS FOR SHOWERS AND THUNDERSTORMS. THIS FRONT WILL BE SLOW TO
ADVANCE BUT WILL BRING A GOOD CHANCE OF SHOWER AND THUNDERSTORM
ACTIVITY TO THE COMMONWEALTH FOR THE WEEKEND.
THE LACK OF RAINFALL EARLY IN THE WEEK WILL ALLOW TEMPERATURES TO
SOAR TO THE UPPER 80S TO LOWER 90S AND WHEN COUPLED WITH DEW POINTS
IN THE UPPER 60S AND LOWER 70S...WILL PUSH HEAT INDEX VALUES EACH
AFTERNOON INTO THE LOWER AND MID 90S. THE HIGH DEWPOINTS WILL
RESTRICT OVERNIGHT LOWS TO THE LOWER 70S WITH THE PRIMARY WEATHER
OVERNIGHT BECOMING VALLEY FOG UNDER MOSTLY CLEAR SKIES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 835 AM EDT SAT JUL 13 2013
AN EXITING UPPER LEVEL LOW PRESSURE SYSTEM HAS ALLOWED FOR SCATTERED
TO NUMEROUS CONVECTION THIS MORNING. EXPECT THE BEST COVERAGE TO MOVE
OUT THROUGH 16Z...WITH MAINLY ISOLATED COVERAGE EXPECTED THEREAFTER.
IFR OR WORSE CONDITIONS CAN BE EXPECTED IN ANY PASSING THUNDERSTORMS.
ALL CONVECTION WILL DISSIPATE THIS EVENING...WITH PATCHY VALLEY FOG
LIKELY FORMING ONCE AGAIN BETWEEN 06 AND 12Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...DUSTY
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS DULUTH MN
150 PM CDT SAT JUL 13 2013
.AVIATION...18Z TAFS...A MIXTURE OF VFR AND MVFR CIGS ACROSS THE
REGION AS ISSUANCE TIME. VISIBLE SATELLITE SHOWS BREAKS INT HE
CLOUDS AT INL...HIB...AND AT HYR. THIS VARIANCE IN CIGS WILL
CONTINUE INTO THIS EVENING WHEN THEY WILL BE MAINLY MVFR WITH IFR
CIGS IN PRECIPITATION THROUGH MOST OF TONIGHT. THE ONLY EXCEPTION
WILL BE AT HYR WHERE VFR-MVFR CIGS SHOULD BE DOMINANT. CONDITIONS
WILL IMPROVE TO VFR SUNDAY MORNING WITH SOME MVFR CIGS DUE TO
LEFT OVER SHOWERS.
&&
.PREV DISCUSSION... /ISSUED 138 PM CDT SAT JUL 13 2013/
UPDATE...
LATEST SFC ANALYSIS SHOWS THE NORTHLAND POSITIONED IN TROPICAL AIR
MASS AHEAD OF A COLD FRONT STALLED OVER SRN MANITOBA. A SECONDARY
WEAK SFC TROUGH CAN BE FOUND ACROSS NRN MINNESOTA...EXTENDING
SOUTHWEST BACK INTO EASTERN SODAK. DEW POINTS ALONG THIS TROUGH ARE
POOLING INTO THE UPPER 60S WITH A FEW LOCATIONS REPORTING LOW 70S.
THIS REGION...GENERALLY FROM CHIPPEWA NATIONAL FOREST THROUGH THE MN
IRON RANGE AND INTO THE ARROWHEAD...WILL CONTINUE TO BE THE FOCUS
FOR TSTORMS DEVELOPMENT THIS AFTERNOON. ALTHOUGH SHEAR AND
MUCAPE VALUES CONTINUE TO RISE IN THIS REGION...HAVE LOWERED POPS
AS STRONG MID LEVEL CAP IS LIMITING INITIATION. DIFFICULT TO
DETERMINE IF AND WHEN THE CAP MAY BECOME OVER RUN.
PREV DISCUSSION... /ISSUED 1054 AM CDT SAT JUL 13 2013/
UPDATE...
FORECAST UPDATE TO REFRESH MORNING WORDING AND INCREASE RAINFALL
AMOUNTS SIGNIFICANTLY OVERNIGHT/SUNDAY...MAINLY FROM THE BRAINERD
LAKES AREA...THROUGH THE IRON RANGE AND ACROSS THE MINNESOTA
ARROWHEAD. LATEST NAM BUFR SOUNDINGS AT KBRD-KELO SUGGEST A
CORRIDOR OF NEAR RECORD PWATS...IN EXCESS OF 2 INCHES...BECOMES
CO-LOCATED WITH THE STATIONARY BOUNDARY TONIGHT AND SUNDAY. IF
THERE IS ENOUGH FORCING/INSTABILITY FOR CONVECTION ALONG THIS
FRONT...PERIODS OF HEAVY RAINFALL WILL BE POSSIBLE. DIFFICULTY
REMAINS IN THE EXACT PLACEMENT OF THE FRONT OVER THE NEXT 24-36
HOURS. THE 15Z RUC MESO ANALYSIS SHOWS A WELL DEFINED H85 BOUNDARY
CURRENTLY EXTENDS WEST TO EAST ACROSS THE NORTHLAND...GENERALLY
FROM CASS COUNTY...TO THE TWIN PORTS...AND EAST OVER LAKE
SUPERIOR. LOCATIONS ALONG AND NORTH OF THIS BOUNDARY AREA
EXPECTED TO SEE THE BEST CHANCE FOR THUNDERSTORM REDEVELOPMENT
THIS AFTERNOON....CONTINUING OVERNIGHT. LIMITING FACTOR TO STORMS
AND HEAVY RAIN WILL THE STRENGTH OF THE A MID LEVEL CAP. LATEST
NAM12 SUGGESTS WIDESPREAD H70 TEMPS IN THE 9-10 C RANGE ENCOMPASS
THE REGION TONIGHT THROUGH SUNDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 659 AM CDT SAT JUL 13 2013/
AVIATION...12Z TAF ISSUANCE...
LARGE AREA OF RAIN/STORMS HAS WEAKENED OVER NWRN WISC EARLY THIS
MORNING. IN ITS WAKE...AN AREA OF MVFR CEILINGS HAVE DEVELOPED
NEAR KDLH/KHIB ALONG WITH LOCAL BR AT KINL. TOUGH FCST TRYING TO
TIME/PLACE THE REDEVELOPING STORMS TODAY. ALTHOUGH STORMS MAY
DEVELOP ALMOST ANYWHERE DUE TO THE VERY HIGH MOISTURE CONTENT IN
THE ATMOSPHERE...THE GENERAL IDEA IS THAT THE HIGHEST PROBABILITY WILL
BE OVER WISC THIS MORNING...AND THEN SHIFTING TOWARDS KBRD/KDLH
THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 410 AM CDT SAT JUL 13 2013/
SHORT TERM...TODAY AND TONIGHT...
AN ACTIVE MORNING ACROSS THE NORTHLAND THIS MORNING...WITH
THUNDERSTORMS MOVING FROM THE EASTERN PORTIONS OF THE MINNESOTA CWA
ACROSS LAKE SUPERIOR AND INTO NORTHWEST WISCONSIN. SO FAR HAVE ONLY
HAD REPORTS OF HEAVY RAIN AND FREQUENT LIGHTNING. NOT TOO
SURPRISING GIVEN THAT MU CAPE VALUES ARE 500-1000J/KG AND VERY
LITTLE SHEAR OR OTHER FACTORS THAT MAKE NOCTURNAL STORMS REALLY GET
VIGOROUS. THESE STORMS FORMED OVER EASTERN NORTH DAKOTA THIS
AFTERNOON ALONG THE TROUGH AXIS EXTENDING NORTH FROM A SURFACE LOW
OVER CENTRAL SOUTH DAKOTA. WITH THE UNSTABLE AIR AND WEAKLY CAPPED
AIRMASS TO THE EAST THE STORMS HAVE JUST KEPT MOVING ON EAST.
EXPECT THEM TO CONTINUE TO GRADUALLY DIMINISH...AND EXPECT THE
GREATEST DIMINISHMENT TREND AFTER SUNRISE THIS MORNING. THUS...HAVE
LIMITED THE MID TO LATE MORNING HOURS TO JUST CHANCE POPS...THOUGH
THE EARLY MORNING HOURS ARE MUCH HIGHER. THIS AFTERNOON THE
THUNDERSTORM ACTIVITY LOCATION IS A LITTLE HARDER TO PIN DOWN...AND
MUCH IS GOING TO DEPEND ON WHERE THE ATMOSPHERE FORMS A BOUNDARY
BEHIND THIS MORNING CONVECTION...AND WHERE IT SHIFTS TO DURING THE
AFTERNOON WITH THE STRONG WARM AIR ADVECTION REGIME ONGOING AND THE
INVERTED TROUGH AXIS AND SURFACE LOW ONLY MARGINALLY FARTHER EAST
THAN THEY WERE FRIDAY AFTERNOON. FOR NOW AM FAVORING A SLIGHTLY
FARTHER NORTH INITIATION...ALONG THE LINES OF MORE OF THE SHORT
RANGE MODELS...GENERALLY EXTENDING FROM THE PEQUOT LAKES AND LEECH
LAKE AREAS...NORTHEAST UP INTO THE ARROWHEAD. THE AFTERNOON AND
EVENING ACTIVITY IS GOING TO BE MORE SCATTERED IN NATURE...WITHOUT A
SINGLE STRONG TRIGGER TO ACT UPON. BY LATER IN THE EVENING AND
OVERNIGHT THOUGH...THE LOW LEVEL JET KICKS IN...AND EXPECT FAR MORE
DEVELOPMENT ALONG AND NORTH OF THE SAME AXIS...AND HAVE RAISED POPS
FOR THE OVERNIGHT HOURS. AS FOR TEMPERATURES...INCREASED CLOUDS ARE
GOING TO TEND TO KEEP THEM COOLER...BUT THE STRONG WARM AIR
ADVECTION HAS BROUGHT IN A VERY WARM AIRMASS AND WE WILL BE STARTING
OUT MUCH WARMER THAN YESTERDAY. SO...HAVE TEMPERATURES COOLER THAN
YESTERDAY BUT NOT BY A LARGE AMOUNT. THE INCREASED LOW LEVEL
MOISTURE IS GOING TO KEEP CONDITIONS VERY MUGGY. TONIGHT HAVE
CONTINUED THE WARM TEMPS WITH MINS IN THE MID 60S AGAIN.
EXTENDED...SUNDAY THROUGH FRIDAY...
A RETROGRADING AND EXPANDING MID LVL HIGH WILL PUSH WEST FROM THE
ERN CONUS INTO THE OHIO VALLEY OVER THE NEXT 5 DAYS. THIS WILL KEEP
THE MAIN JET AXIS NORTH OF THE CWA UNTIL AT LEAST MIDWEEK. THE
RESULT SHOULD BE A CONTINUATION OF A WARM AND HUMID WEATHER PATTERN.
A TREND FOR THE AREA OF SCTD CONVECTION TO LIFT NORTH MONDAY AND
TUESDAY. THIS APPEARS REASONABLE GIVEN THE CLOSER PROXIMITY TO THE
FRONTAL BDRY CONVERGENCE AND UPPER JET AXIS. A CANADIAN COLD FRONT
WILL PUSH SOUTH ACROSS THE REGION LATE WEDNESDAY. THIS SHOULD USHER
IN A DRIER AIR MASS WITH LOWER DEWPOINTS AND NWRLY WINDS. THIS MAY
BE SHORT LIVED AS MDLS SUGGEST FRONTAL BDRY MAY ATTEMPT TO MOVE
NORTHWARD THURSDAY. GFS/EC/GEM AT ODDS WITH EACH OTHER WITH EC MUCH
MORE AGGRESSIVE ON DRY PUSH SOUTH WHILE GFS/GEM KEEP CHANCES OF
RW/TRW THROUGH THE PERIOD. ALLBLEND SOLUTION KEEPS PRECIP IN FCST
THROUGH WEEK. GIVEN THE POTENTIAL CHANGES ALOFT WITH AMPLIFYING MID
LVL TROF LATE IN THE WEEK....CONFIDENCE IN FCST WED-FRI NOT VERY
HIGH.
&&
.POINT TEMPS/POPS...
DLH 80 64 80 63 / 30 70 50 40
INL 85 68 79 62 / 10 40 30 50
BRD 81 69 81 66 / 20 80 60 30
HYR 82 63 86 65 / 20 20 10 10
ASX 82 64 83 62 / 20 20 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
LONG TERM....STEWART
AVIATION...STEWART
AREA FORECAST DISCUSSION
NWS DULUTH MN
138 PM CDT SAT JUL 13 2013
.UPDATE...
LATEST SFC ANALYSIS SHOWS THE NORTHLAND POSITIONED IN TROPICAL AIR
MASS AHEAD OF A COLD FRONT STALLED OVER SRN MANITOBA. A SECONDARY
WEAK SFC TROUGH CAN BE FOUND ACROSS NRN MINNESOTA...EXTENDING
SOUTHWEST BACK INTO EASTERN SODAK. DEW POINTS ALONG THIS TROUGH ARE
POOLING INTO THE UPPER 60S WITH A FEW LOCATIONS REPORTING LOW 70S.
THIS REGION...GENERALLY FROM CHIPPEWA NATIONAL FOREST THROUGH THE MN
IRON RANGE AND INTO THE ARROWHEAD...WILL CONTINUE TO BE THE FOCUS
FOR TSTORMS DEVELOPMENT THIS AFTERNOON. ALTHOUGH SHEAR AND
MUCAPE VALUES CONTINUE TO RISE IN THIS REGION...HAVE LOWERED POPS
AS STRONG MID LEVEL CAP IS LIMITING INITIATION. DIFFICULT TO
DETERMINE IF AND WHEN THE CAP MAY BECOME OVER RUN.
&&
.PREV DISCUSSION... /ISSUED 1054 AM CDT SAT JUL 13 2013/
UPDATE...
FORECAST UPDATE TO REFRESH MORNING WORDING AND INCREASE RAINFALL
AMOUNTS SIGNIFICANTLY OVERNIGHT/SUNDAY...MAINLY FROM THE BRAINERD
LAKES AREA...THROUGH THE IRON RANGE AND ACROSS THE MINNESOTA
ARROWHEAD. LATEST NAM BUFR SOUNDINGS AT KBRD-KELO SUGGEST A
CORRIDOR OF NEAR RECORD PWATS...IN EXCESS OF 2 INCHES...BECOMES
CO-LOCATED WITH THE STATIONARY BOUNDARY TONIGHT AND SUNDAY. IF
THERE IS ENOUGH FORCING/INSTABILITY FOR CONVECTION ALONG THIS
FRONT...PERIODS OF HEAVY RAINFALL WILL BE POSSIBLE. DIFFICULTY
REMAINS IN THE EXACT PLACEMENT OF THE FRONT OVER THE NEXT 24-36
HOURS. THE 15Z RUC MESO ANALYSIS SHOWS A WELL DEFINED H85 BOUNDARY
CURRENTLY EXTENDS WEST TO EAST ACROSS THE NORTHLAND...GENERALLY
FROM CASS COUNTY...TO THE TWIN PORTS...AND EAST OVER LAKE
SUPERIOR. LOCATIONS ALONG AND NORTH OF THIS BOUNDARY AREA
EXPECTED TO SEE THE BEST CHANCE FOR THUNDERSTORM REDEVELOPMENT
THIS AFTERNOON....CONTINUING OVERNIGHT. LIMITING FACTOR TO STORMS
AND HEAVY RAIN WILL THE STRENGTH OF THE A MID LEVEL CAP. LATEST
NAM12 SUGGESTS WIDESPREAD H70 TEMPS IN THE 9-10 C RANGE ENCOMPASS
THE REGION TONIGHT THROUGH SUNDAY AFTERNOON.
PREV DISCUSSION... /ISSUED 659 AM CDT SAT JUL 13 2013/
AVIATION...12Z TAF ISSUANCE...
LARGE AREA OF RAIN/STORMS HAS WEAKENED OVER NWRN WISC EARLY THIS
MORNING. IN ITS WAKE...AN AREA OF MVFR CEILINGS HAVE DEVELOPED
NEAR KDLH/KHIB ALONG WITH LOCAL BR AT KINL. TOUGH FCST TRYING TO
TIME/PLACE THE REDEVELOPING STORMS TODAY. ALTHOUGH STORMS MAY
DEVELOP ALMOST ANYWHERE DUE TO THE VERY HIGH MOISTURE CONTENT IN
THE ATMOSPHERE...THE GENERAL IDEA IS THAT THE HIGHEST PROBABILITY WILL
BE OVER WISC THIS MORNING...AND THEN SHIFTING TOWARDS KBRD/KDLH
THIS AFTERNOON.
PREV DISCUSSION... /ISSUED 410 AM CDT SAT JUL 13 2013/
SHORT TERM...TODAY AND TONIGHT...
AN ACTIVE MORNING ACROSS THE NORTHLAND THIS MORNING...WITH
THUNDERSTORMS MOVING FROM THE EASTERN PORTIONS OF THE MINNESOTA CWA
ACROSS LAKE SUPERIOR AND INTO NORTHWEST WISCONSIN. SO FAR HAVE ONLY
HAD REPORTS OF HEAVY RAIN AND FREQUENT LIGHTNING. NOT TOO
SURPRISING GIVEN THAT MU CAPE VALUES ARE 500-1000J/KG AND VERY
LITTLE SHEAR OR OTHER FACTORS THAT MAKE NOCTURNAL STORMS REALLY GET
VIGOROUS. THESE STORMS FORMED OVER EASTERN NORTH DAKOTA THIS
AFTERNOON ALONG THE TROUGH AXIS EXTENDING NORTH FROM A SURFACE LOW
OVER CENTRAL SOUTH DAKOTA. WITH THE UNSTABLE AIR AND WEAKLY CAPPED
AIRMASS TO THE EAST THE STORMS HAVE JUST KEPT MOVING ON EAST.
EXPECT THEM TO CONTINUE TO GRADUALLY DIMINISH...AND EXPECT THE
GREATEST DIMINISHMENT TREND AFTER SUNRISE THIS MORNING. THUS...HAVE
LIMITED THE MID TO LATE MORNING HOURS TO JUST CHANCE POPS...THOUGH
THE EARLY MORNING HOURS ARE MUCH HIGHER. THIS AFTERNOON THE
THUNDERSTORM ACTIVITY LOCATION IS A LITTLE HARDER TO PIN DOWN...AND
MUCH IS GOING TO DEPEND ON WHERE THE ATMOSPHERE FORMS A BOUNDARY
BEHIND THIS MORNING CONVECTION...AND WHERE IT SHIFTS TO DURING THE
AFTERNOON WITH THE STRONG WARM AIR ADVECTION REGIME ONGOING AND THE
INVERTED TROUGH AXIS AND SURFACE LOW ONLY MARGINALLY FARTHER EAST
THAN THEY WERE FRIDAY AFTERNOON. FOR NOW AM FAVORING A SLIGHTLY
FARTHER NORTH INITIATION...ALONG THE LINES OF MORE OF THE SHORT
RANGE MODELS...GENERALLY EXTENDING FROM THE PEQUOT LAKES AND LEECH
LAKE AREAS...NORTHEAST UP INTO THE ARROWHEAD. THE AFTERNOON AND
EVENING ACTIVITY IS GOING TO BE MORE SCATTERED IN NATURE...WITHOUT A
SINGLE STRONG TRIGGER TO ACT UPON. BY LATER IN THE EVENING AND
OVERNIGHT THOUGH...THE LOW LEVEL JET KICKS IN...AND EXPECT FAR MORE
DEVELOPMENT ALONG AND NORTH OF THE SAME AXIS...AND HAVE RAISED POPS
FOR THE OVERNIGHT HOURS. AS FOR TEMPERATURES...INCREASED CLOUDS ARE
GOING TO TEND TO KEEP THEM COOLER...BUT THE STRONG WARM AIR
ADVECTION HAS BROUGHT IN A VERY WARM AIRMASS AND WE WILL BE STARTING
OUT MUCH WARMER THAN YESTERDAY. SO...HAVE TEMPERATURES COOLER THAN
YESTERDAY BUT NOT BY A LARGE AMOUNT. THE INCREASED LOW LEVEL
MOISTURE IS GOING TO KEEP CONDITIONS VERY MUGGY. TONIGHT HAVE
CONTINUED THE WARM TEMPS WITH MINS IN THE MID 60S AGAIN.
EXTENDED...SUNDAY THROUGH FRIDAY...
A RETROGRADING AND EXPANDING MID LVL HIGH WILL PUSH WEST FROM THE
ERN CONUS INTO THE OHIO VALLEY OVER THE NEXT 5 DAYS. THIS WILL KEEP
THE MAIN JET AXIS NORTH OF THE CWA UNTIL AT LEAST MIDWEEK. THE
RESULT SHOULD BE A CONTINUATION OF A WARM AND HUMID WEATHER PATTERN.
A TREND FOR THE AREA OF SCTD CONVECTION TO LIFT NORTH MONDAY AND
TUESDAY. THIS APPEARS REASONABLE GIVEN THE CLOSER PROXIMITY TO THE
FRONTAL BDRY CONVERGENCE AND UPPER JET AXIS. A CANADIAN COLD FRONT
WILL PUSH SOUTH ACROSS THE REGION LATE WEDNESDAY. THIS SHOULD USHER
IN A DRIER AIR MASS WITH LOWER DEWPOINTS AND NWRLY WINDS. THIS MAY
BE SHORT LIVED AS MDLS SUGGEST FRONTAL BDRY MAY ATTEMPT TO MOVE
NORTHWARD THURSDAY. GFS/EC/GEM AT ODDS WITH EACH OTHER WITH EC MUCH
MORE AGGRESSIVE ON DRY PUSH SOUTH WHILE GFS/GEM KEEP CHANCES OF
RW/TRW THROUGH THE PERIOD. ALLBLEND SOLUTION KEEPS PRECIP IN FCST
THROUGH WEEK. GIVEN THE POTENTIAL CHANGES ALOFT WITH AMPLIFYING MID
LVL TROF LATE IN THE WEEK....CONFIDENCE IN FCST WED-FRI NOT VERY
HIGH.
&&
.POINT TEMPS/POPS...
DLH 64 80 63 82 / 70 50 40 20
INL 68 79 62 80 / 40 40 50 40
BRD 69 81 66 85 / 80 60 30 20
HYR 63 86 65 86 / 20 10 10 10
ASX 64 83 62 82 / 20 30 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...GRANING
LONG TERM....STEWART
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
131 PM CDT SAT JUL 13 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 309 AM CDT SAT JUL 13 2013
AREA OF CONVECTION CONTINUES TO TRACK EAST AROUND 24 KNOTS. THE
UPPER TROUGH ASSOCIATED APPEARS TO BE WEAKENING A BIT AS IT RIDES
INTO THE RIDGE OVER THE GREAT LAKES REGION. RADAR ACTIVITY HAS
SLOWED A BIT IN THE LATEST HOUR...AND IS REGENERATING TO THE
WEST...PROBABLY AN INDICATION OF THE WAVE SLOWING AND MOVING INTO
THE RIDGE SITUATED TO THE EAST. LATEST SPC MESOSCALE ANALYSIS SHOWS
ACTIVITY ELEVATED WITH ACTIVITY DRIVEN BY WAA PATTERN WITH THE UPPER
TROUGH. DECENT MOISTURE TRANSPORT ASSOCIATED AS WELL...WITH BRIEF
DOWNPOURS WITH THE ACTIVITY. QUESTION REMAINS HOW FAR EAST THIS
WILL GO THIS MORNING BEFORE DISSIPATING. THE LATEST HRRR TRENDS
INDICATE THIS AREA WILL WORK EAST INTO WEST CENTRAL WI.
ALSO...SECONDARY AREA OF 850MB WAA REGENERATING TO THE
SOUTHWEST...INTO SOUTHEAST SOUTH DAKOTA. THIS IS AN EXTENSION TO
THE LOW LEVEL JET AND MAY BE ASSOCIATED WITH SOUTHERN SODAK WAVE
LIFTING NORTHEAST AND MOVING INTO WEST CENTRAL MN THIS
AFTERNOON...PER LATEST DETERMINISTIC MODEL TRENDS.
WILL HOLD ONTO CHANCE BUT DECREASE TO SLIGHT CHANCE THROUGH
18Z...THEN INCREASE POPS AGAIN TO THE NORTHWEST TO CHANCE AFTER
21Z...NEAREST TO THE AREA OF THE SURFACE FRONT. DESTABILIZATION WILL
OCCUR...WITH AMOUNT OF HEATING DETERMINED ON HOW MUCH SUNSHINE WILL
DEVELOP. SHOULD SEE AT LEAST SOME AS THESE SYSTEMS WANE THIS
MORNING. BEST INSTABILITY RIDES TO THE NORTHWEST BY LATE AFTERNOON
WITH SOME POSSIBILITY OF STRONG WINDS AND HEAVY RAIN INTO THE EVENING
PER LATEST SPC DAY ONE OUTLOOK.
WILL MENTION LIKELY POPS TO THE NORTHWEST AND DRIVE CHANCE POPS DOWN
A BIT FARTHER TO THE SOUTHEAST AGAIN TONIGHT...JUST IN CASE ACTIVITY
IS MORE ROBUST THAN MODELS INDICATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 309 AM CDT SAT JUL 13 2013
STRONG MID LEVEL RIDGING WILL BEGIN BUILDING WESTWARD ACROSS THE
OHIO VALLEY AND SOUTHERN GREAT LAKES SUNDAY MORNING WITH 500 MB
HEIGHTS OF NEARLY 600 DAM CENTERED OVER NERN OHIO BY AFTERNOON.
MUCH DRIER AIR WILL ACCOMPANY THIS RIDGING SO EXPECTING A SHARP
DROP OFF IN PRECIPITABLE WATER FROM EAST TO WEST DURING THE DAY.
PW COULD RANGE FROM 0.75-1.0 INCH ACROSS SRN MN/WRN WI TO
2.0-2.25 INCHES ACROSS WRN MN. MAINTAINED VERY LOW POPS AND SUNNY
SKIES OVER THE SOUTH AND EAST AND MAINTAINED MEDIUM RANGE POPS
NORTHWEST. LOW MBE VELOCITIES...VERY DEEP WARM CLOUD DEPTH...AND
HIGH PW/S ALONG THE STATIONARY FRONT COULD LEAD TO LOCALLY HEAVY
RAIN AND FLOODING. BY SUNDAY NIGHT...THE DRIER AIR WILL CONTINUE
TO ADVANCE WESTWARD AND BRING DIMINISHING CHANCES OF RAIN ACROSS
WRN MN.
THE RIDGE WILL SLOWLY SETTLE OVER NORTHERN INDIANA THROUGH THE
MIDDLE OF NEXT WEEK. THERMAL PROFILES WILL INCH UP EACH DAY AND
925 MB TEMPS BY WEDNESDAY AND THURSDAY MAY TOP +27 OR +28C. HIGHS
IN THE LOW TO MID 90S ARE A GOOD BET...AND COULD BE EVEN WARMER. PW/S
WILL ALSO INCREASE BACK TO AROUND 1.75 INCHES AND SURFACE DEW
POINTS WILL HOVER ON EITHER SIDE OF 70F. HEAT INDICES MAY BECOME
AN ISSUE BY MIDWEEK WITH READINGS POTENTIALLY EXCEEDING 100F.
CANNOT RULE OUT HEAT HEADLINES IF THIS IS TO VERIFY...PARTICULARLY
WHEN LOWS FAIL TO DROP BELOW 75 IN THE METRO.
SOMETHING THAT MAY BRING RELIEF DURING THIS PERIOD ARE LOW
PROBABILITIES OF THUNDERSTORMS. DESPITE SUCH A POTENT RIDGE...THE
PROFILE IS LACKING OF ANY SIGNIFICANT INVERSION SO WE COULD SEE
POP UP STORMS WEDNESDAY AND THURSDAY.
BY FRIDAY...THE RIDGE WILL BEGIN TO BREAK DOWN AND A COLD FRONT
WILL SAG SOUTH THROUGH THE UPPER MIDWEST. LOWER HUMIDITY AND
TEMPERATURES CLOSER TO AVERAGE ARE ANTICIPATED BY THE END OF THE
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 108 PM CDT SAT JUL 13 2013
THERE IS STILL ON AREA OF SHOWERS AND WEAK STORMS MOVING ACROSS
MN THIS AFTERNOON. THIS IS NOT EXPECTED TO CAUSE MANY PROBLEMS AND
THE THUNDER WILL LIKELY STAY SOUTH OF KRNH/KMSP...ALTHOUGH COULD
BE CLOSE /PERHAPS WITHIN 20-30 MILES/. OTHERWISE...MOSTLY VFR THIS
AFTERNOON AND EVENING WITH JUST A FEW POCKETS OF 2000-3500FT
CEILINGS TO AVOID TODAY. THUNDERSTORM CHANCES INCREASE AGAIN LATE
THIS EVENING IN WESTERN MN AND SHOULD MOVE E-SE WITH TIME.
KAXN/KRWF LOOK ONCE AGAIN IN A PRIME LOCATION FOR THUNDER...BUT
KSTC/KMSP AND EVEN KRNH TO SOME DEGREE COULD BE CLOSE.
KMSP...
WILL SAY THAT THIS MORNING WAS UNEXPECTED AS WE THOUGHT MOST OF
THE THUNDERSTORM ACTIVITY WOULD REMAIN NORTH AND WEST. WE THINK
THAT WILL BE THE CASE TONIGHT WITH STORMS AND HEAVY RAIN FOCUSING
MORE IN WESTERN MN. HOWEVER...ONCE AGAIN...THIS ACTIVITY COULD
DRIFT E-SE WITH TIME AND THE AIRPORT COULD HAVE THUNDERSTORMS NEAR
SUNRISE. CONFIDENCE IN SPECIFICS IS NOT VERY HIGH...BUT SOMETHING
TO WATCH OVER THE NEXT 9-12 HOURS.
/OUTLOOK FOR KMSP/
SUN NIGHT...VFR. WINDS S 10KT.
MON...VFR. WINDS S 5-10 KT.
TUE...VFR. WINDS SW 5-10 KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...DWE
LONG TERM...BORGHOFF
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
249 PM MDT Sat Jul 13 2013
.DISCUSSION...
This Afternoon through Monday Evening...Well-defined pattern of
southwest flow aloft remains parked over the Northern Rockies, with
little change expected well into next week. Weak upper-level
shortwave trof that brought light showers to central/western
portions of the Hiline this morning is now near Havre, pushing
steadily eastward. The dry airmass along the northern and middle
portions of the trof axis should keep the Hiline and central
counties precipitation-free through this evening. but scattered
showers and a few short-lived (pulse type) thunderstorms have
developed over southern portions of Beaverhead/Madison/Gallatin
Counties where the far end of the trof axis is tapping into the
western edge of a monsoonal moisture plume over WY/southern MT.
Expect this convective activity to continue into the evening hours
before the trof axis moves downstream. Main threat with these storms
will be strong outflow winds of 45 mph or higher. Forecast models
continue to be in good agreement that Sun will be a close repeat of
today (without the morning showers over the Hiline), with
temperatures warming up into the mid 80s over the plains and
valleys. By Monday the large high pressure ridge over OK/TX is
forecast to gradually retrograde (drift westward) back to the Four
Corners area. This will turn our flow aloft slight more southerly,
bringing in much warmer airmass from the Great Basin, resulting in
highs reaching the upper 80s to mid 90s. The repositioning of the
ridge will also push the monsoonal moisture plume back into eastern
ID and southwest MT for another round of showers and thunderstorms
there Mon aftn/eve.
Waranauskas
Monday Night through Saturday...A weak Canadian cold front will
move through the northern half of the forecast area Monday night
into Tuesday morning. Though widespread precipitation is not
expected, a few showers and thunderstorms will be possible over
north- central Montana, mainly for areas east of I-15 and north of
MT-200. Northerly surface winds behind the front will decrease
temperatures around 10 degrees for Tuesday, but highs will still
remain around seasonal averages. Unsettled west- southwesterly
flow aloft and warmer than average temperatures will return for
the middle to end of next week with afternoon showers and
thunderstorms possible almost each day as embedded shortwaves move
across the forecast area. Increasing Monsoonal moisture will focus
most of the thunderstorm activity over southwest Montana,
especially on Wednesday afternoon/evening as a stronger shortwave
moves over the area. Across north-central Montana, diurnal
instability and light east- southeasterly surface winds should
advect enough moisture to also support isolated thunderstorms
throughout the forecast period. Temperatures will generally be 5
to 10 degrees above seasonal averages with expected highs in the
upper 80s to low 90s through late next week. MLV
&&
.AVIATION...
UPDATED 1730Z.
A weak upper level trough produced a band of -SHRA moving eastbound
across north central MT as shown on radar and surface obs. Visible
satellite and RUC model data suggests cloud cover will increase this
afternoon east of a line from KGTF to KHVR with rain showers
persisting in vicinity of KHVR. Flight category is expected to
remain VFR even with light rain showers. Isolated convection is
expected over southwest MT with VCTS affecting KBZN early this
evening. Convection moves further east overnight with a low chance
of -SHRA affecting KLWT. Winds will rotate through northeasterly as
surface high pressure moves across the state through Sunday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 49 85 54 92 / 10 10 10 10
CTB 46 80 49 85 / 10 10 10 10
HLN 53 88 56 93 / 10 20 10 10
BZN 48 87 51 91 / 20 20 20 20
WEY 40 80 41 83 / 20 20 20 20
DLN 48 86 50 89 / 10 20 10 20
HVR 51 83 57 89 / 10 10 10 10
LWT 49 80 54 86 / 20 10 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WARANAUSKAS
LONG TERM...MLV
AVIATION...NUTTER
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1129 MDT Sat Jul 13 2013
Aviation Section Updated.
.UPDATE...
Latest radar imagery still showing narrow band of light rain showers
extending from central Teton County northeastward to northern
portions of Liberty/Hill Counties, associated with a weak trof
moving through north-central MT. Expect these showers to continue
for another hour or so, then dissipate. Forecast still on track for
dry conditions over most of the region today, with only scattered
showers and a thunderstorm or two over far southwest MT later this
aftn. Only forecast grid changes were to adjust precipitation
chances over the Hiline counties to better match current area of
rainfall.
Waranauskas
&&
.DISCUSSION...
Today through Monday...Southwest flow aloft will persist over the
forecast area as an upper low moves south through British Columbia
then weakens and moves into Alberta on Monday. Early this morning
there was some shower activity over the the northern Rocky
Mountain Front and nearby plains. This activity was associated
with a weather disturbance aloft over the Pacific Northwest.
Shower activity will continue ahead of the disturbance as it moves
into central Canada during the afternoon. An unstable airmass and
lift from terrain should develop a few thunderstorms over
southwest Montana this afternoon. Another weather disturbance
aloft will move into northcentral Montana Sunday morning. This
disturbance combined with an unstable airmass should produce
isolated to scattered showers along with isolated thunderstorms
over central/north central Montana later tonight into Sunday
morning. Then Sunday afternoon expect another round of isolated to
scattered showers and thunderstorms over southwest Montana which
will spread northeast during the evening. For Monday models are
indicating a drier airmass over most of the forecast area but the
airmass should not be so dry as to prevent isolated showers and
thunderstorms over southwest Montana and also possibly over Fergus
and Blaine counties. For today through Monday there will be the
potential for gusty winds and small hail with the thunderstorms
but see little threat for severe thunderstorms. Blank
Monday Night through Saturday...A weak Canadian cold front will
move through the northern half of the forecast area Monday night
into Tuesday morning. Though widespread precipitation is not
expected, a few showers and thunderstorms will be possible over
north- central Montana, mainly for areas east of I-15 and north of
MT-200. Northerly surface winds behind the front will decrease
temperatures around 10 degrees for Tuesday, but highs will still
remain around seasonal averages. Unsettled west- southwesterly
flow aloft and warmer than average temperatures will return for
the middle to end of next week with afternoon showers and
thunderstorms possible almost each day as embedded shortwaves move
across the forecast area. Increasing Monsoonal moisture will focus
most of the thunderstorm activity over southwest Montana,
especially on Wednesday afternoon/evening as a stronger shortwave
moves over the area. Across north-central Montana, diurnal
instability and light east- southeasterly surface winds should
advect enough moisture to also support isolated thunderstorms
throughout the forecast period. Temperatures will generally be 5
to 10 degrees above seasonal averages with expected highs in the
upper 80s to low 90s through late next week. MLV
&&
.AVIATION...
UPDATED 1730Z.
A weak upper level trough produced a band of -SHRA moving eastbound
across north central MT as shown on radar and surface obs. Visible
satellite and RUC model data suggests cloud cover will increase this
afternoon east of a line from KGTF to KHVR with rain showers
persisting in vicinity of KHVR. Flight category is expected to
remain VFR even with light rain showers. Isolated convection is
expected over southwest MT with VCTS affecting KBZN early this
evening. Convection moves further east overnight with a low chance
of -SHRA affecting KLWT. Winds will rotate through northeasterly as
surface high pressure moves across the state through Sunday morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 81 49 85 54 / 10 20 10 10
CTB 73 46 80 49 / 60 10 20 10
HLN 85 53 88 56 / 10 10 20 20
BZN 84 48 87 51 / 20 20 20 20
WEY 78 40 80 41 / 20 20 30 20
DLN 84 48 86 50 / 10 10 20 10
HVR 78 51 83 57 / 20 10 20 10
LWT 76 49 80 54 / 10 30 20 20
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BLANK
LONG TERM...MLV
AVIATION...MLV
weather.gov/greatfalls
AREA FORECAST DISCUSSION
NWS RALEIGH NC
258 PM EDT SAT JUL 13 2013
.SYNOPSIS...
A WEAK WARM FRONT OVER THE REGION WILL MOVE WEST AND DISSIPATE
TONIGHT. HIGH PRESSURE BUILDING IN FROM THE NORTHEAST WILL BRING
DRIER WEATHER AND A TREND TOWARD HOTTER TEMPERATURES FROM SUNDAY
THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM SATURDAY...
LATEST SFC ANALYSIS SHOWS THE WEAK SFC FRONT JUST WEST OF THE I-95
CORRIDOR AND GRADUALLY MOVING WEST. SCATTERED SHOWERS WITH A FEW
EMBEDDED TSTMS CONTINUE ACROSS THE COASTAL PLAIN AND EASTERN
PIEDMONT...AND EXPECT THIS ACTIVITY TO CONTINUE TO GRADUALLY MOVE
WEST AND WEAKEN AS IT APPROACHES THE TRIAD...WHERE THE LATEST
MESOANALYSIS SHOWS LESS THAN 500J/KG MLCAPE. LATEST HRRR AND TO SOME
EXTENT THE WRF ARW WANT TO TAKE THIS ACTIVITY AND PUSH IT WEST
ACROSS THE TRIAD LATE THIS AFTERNOON. WHILE THIS STILL MAY
HAPPEN...THE CURRENT THERMODYNAMIC PROFILE SUGGESTS THAT IT SHOULD
BE FAIRLY MODEST INTENSITY IF IT OCCURS.
IN THE BIGGER PICTURE...THE CLOSED LOW OVER WRN KY APPEARS TO BE
PICKING UP SOME SPEED IN ITS WWD MOVEMENT...AND IS PROGGED TO BE
OVER MO BY 06Z TONIGHT. MEANWHILE...THE RIDGE OVER NEW ENGLAND IS
PROGGED TO BUILD SOUTH AND WEST ACROSS THE MID ATLANTIC DURING THIS
TIME. THE NET EFFECT FOR US IS THAT THE CURRENT AIRMASS
CHARACTERIZED BY 2+INCHES OF PWAT SHOULD FINALLY BEGIN TO MOVE WEST
OF OUR CWA AND ALLOW SOME DRIER AIR TO OUR E AND NE (AS CURRENTLY
SEEN ON WATER VAPOR AND IN THE BLENDED TPW PRODUCT) TO MOVE INTO OUR
AREA. MOST CAMS THUS SHOW RAIN ENDING ACROSS OUR CWA AROUND OR
SHORTLY AFTER 00Z THIS EVENING. DESPITE NOTEWORTHY DRYING ABOVE
H8...GUIDANCE CONTINUES TO SHOW THE LOW LEVEL AIRMASS REMAINING
QUITE MOIST (AS INDICATED BY PERSISTENT 70F DWPTS)...THUS LOOK FOR
ANOTHER NIGHT OF LOW CLOUDS AND PERHAPS SOME FOG SETTING UP BETWEEN
03Z-06Z AND LINGERING THROUGH SUNRISE. PERSISTENCE FOR LOWS...AROUND
70 FOR MOST CENTRAL NC LOCALES.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 235 PM SATURDAY...
THE RIDGE CENTERED OVER PA SUNDAY MORNING WILL BE THE PRIMARY...AND
MUCH ANTICIPATED INFLUENCE ON OUR WEATHER THROUGH THE SHORT TERM
PERIOD. THE DRYING TREND WILL ALREADY BE UNDERWAY AT THE START OF
THE PERIOD AND SHOULD CONTINUE THROUGH SUNDAY...BUT PRIMARILY ABOVE
THE BOUNDARY LAYER. AS SUCH...LOOK FOR SOME SUNSHINE IN THE
MORNING...FOLLOWING BY BUILDING CU IN THE AFTERNOON AS THE DAYTIME
HEATING PROGRESSES. FORECAST SOUNDINGS SUGGEST THAT THE CU MAY BUILD
ENOUGH TO SUPPORT A FEW SHOWERS AND PERHAPS AN ISOLD TSTM...THUS
WILL CARRY POPS OF 15-20 PERCENT (HIGHEST WEST) TO COVER THIS
POSSIBILITY. HOWEVER THIS IS STILL BELOW OUR CLIMATOLOGICAL POP FOR
THIS TIME OF YEAR. THICKNESSES AND FORECAST SOUNDINGS SUGGEST HIGHS
IN THE UPPER 80S TO NEAR 90.
FOR SUNDAY NIGHT...WITH SFC DPWTS STILL LINGERING AROUND 70...CAN`T
RULE OUT SOME FOG OR EVEN SOME LOW STRATUS EARLY MONDAY MORNING...
BUT SHOULDN`T BE AS WIDESPREAD AS PREV NIGHTS. LOWS IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 257 PM SATURDAY...
UPPER LEVEL LOW PRESSURE CENTER MOVES OVER TX ON MONDAY... WITH
UPPER LEVEL RIDGING OVER THE MIDATLANTIC. THE RIDGE BECOMES QUITE
FLATTENED TUESDAY INTO WEDNESDAY... WITH A LARGE AREA OF LOW
PRESSURE NEAR THE HUDSON BAY AREA OF CANADA AND SEVERAL SHORTWAVE
IMPULSES BEING DRIVEN ALONG THE NORTHERN PERIPHERY OF THE RIDGE. THE
PIEDMONT TROUGH BECOMES MORE PRONOUNCED LATE IN THE WEEK... AND WITH
PWS ONCE AGAIN INCREASING TO AROUND 2 INCHES... WILL SUPPORT
ENHANCED DIURNAL CONVECTION. SHEAR REMAINS WEAK... AND DYNAMIC
FORCING REMAINS WELL TO THE NORTH... RESULTING IN GENERAL PULSE TYPE
CONVECTION. LOW LEVEL THICKNESSES TREND ABOVE NORMAL THROUGH THE
WEEK... AND ACCORDINGLY... HIGHS A FEW DEGREES ABOVE NORMAL AT
AROUND 90 TO START THE WEEK... AND INTO THE LOWER 90S BY WEEKS END.
WITH DEWPOINTS IN THE 70S... HEAT INDEX WILL REACH NEAR 100 DEGREES.
LOWS IN THE LOWER 70S.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1250 PM SATURDAY...
WIDESPREAD MVFR AND ISOLD IFR CONDITIONS DUE TO LOW CIGS CONTINUES
ATTM WEST I-95 AND GENERALLY WEST OF THE WEAK COLD FRONT THAT IS
SLOWLY MOVING WWD. EAST OF I-95...CIGS ARE LIFTING IN THE WARM
SECTOR. IN ADDITION...SCATTERED SHOWERS AND ISOLD TSTM ARE LOCALLY
AND TEMPORARILY REDUCING VISIBILITIES. THIS WILL CONTINUE TO BE THE
TREND THROUGH MUCH OF THE AFTERNOON...WITH CIGS GRADUALLY LIFTING
FROM EAST TO WEST AS THE AFOREMENTIONED FRONT DRIFTS WEST. HOWEVER
SHOWER/TSTM ACTIVITY WILL CONTINUE AND MAY FURTHER INCREASE IN
COVERAGE THIS AFTERNOON AS THE BOUNDARY MOVES WEST AND WITH
ADDITIONAL HEATING. AFT 14/00Z...SHOWER/TSTM ACTIVITY IS EXPECTED TO
DIMINISH WITH LOSS OF HEATING...THEN CIGS WILL GRADUALLY LOWER
THROUGH THE REST OF THE NIGHT GIVEN THE MOIST AIRMASS IN PLACE. LOOK
FOR IFR/LIFR CONDITIONS TO RETURN TO MOST IF NOT ALL OF OUR TAF
SITES BETWEEN 14/03Z-14/06Z AND REMAIN UNTIL 14/13Z. AFT 14/13Z...
CIGS ARE EXPECTED TO RISE TO MVFR...AND TO VFR BY 14/18Z AS A MUCH
DRIER AIR MASS MOVES IN FROM THE EAST AND NORTHEAST.
LOOKING BEYOND...PATCHY MVFR/IFR CIGS ARE POSSIBLE LATE SUNDAY NIGHT
INTO MONDAY MORNING...OTHERWISE CONDITIONS ARE LIKELY TO REMAIN
MOSTLY VFR THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NP
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...SEC
AVIATION...NP
AREA FORECAST DISCUSSION
NWS RALEIGH NC
235 PM EDT SAT JUL 13 2013
.SYNOPSIS...
A WEAK WARM FRONT OVER THE REGION WILL MOVE WEST AND DISSIPATE
TONIGHT. HIGH PRESSURE BUILDING IN FROM THE NORTHEAST WILL BRING
DRIER WEATHER AND A TREND TOWARD HOTTER TEMPERATURES FROM SUNDAY
THROUGH MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 235 PM SATURDAY...
LATEST SFC ANALYSIS SHOWS THE WEAK SFC FRONT JUST WEST OF THE I-95
CORRIDOR AND GRADUALLY MOVING WEST. SCATTERED SHOWERS WITH A FEW
EMBEDDED TSTMS CONTINUE ACROSS THE COASTAL PLAIN AND EASTERN
PIEDMONT...AND EXPECT THIS ACTIVITY TO CONTINUE TO GRADUALLY MOVE
WEST AND WEAKEN AS IT APPROACHES THE TRIAD...WHERE THE LATEST
MESOANALYSIS SHOWS LESS THAN 500J/KG MLCAPE. LATEST HRRR AND TO SOME
EXTENT THE WRF ARW WANT TO TAKE THIS ACTIVITY AND PUSH IT WEST
ACROSS THE TRIAD LATE THIS AFTERNOON. WHILE THIS STILL MAY
HAPPEN...THE CURRENT THERMODYNAMIC PROFILE SUGGESTS THAT IT SHOULD
BE FAIRLY MODEST INTENSITY IF IT OCCURS.
IN THE BIGGER PICTURE...THE CLOSED LOW OVER WRN KY APPEARS TO BE
PICKING UP SOME SPEED IN ITS WWD MOVEMENT...AND IS PROGGED TO BE
OVER MO BY 06Z TONIGHT. MEANWHILE...THE RIDGE OVER NEW ENGLAND IS
PROGGED TO BUILD SOUTH AND WEST ACROSS THE MID ATLANTIC DURING THIS
TIME. THE NET EFFECT FOR US IS THAT THE CURRENT AIRMASS
CHARACTERIZED BY 2+INCHES OF PWAT SHOULD FINALLY BEGIN TO MOVE WEST
OF OUR CWA AND ALLOW SOME DRIER AIR TO OUR E AND NE (AS CURRENTLY
SEEN ON WATER VAPOR AND IN THE BLENDED TPW PRODUCT) TO MOVE INTO OUR
AREA. MOST CAMS THUS SHOW RAIN ENDING ACROSS OUR CWA AROUND OR
SHORTLY AFTER 00Z THIS EVENING. DESPITE NOTEWORTHY DRYING ABOVE
H8...GUIDANCE CONTINUES TO SHOW THE LOW LEVEL AIRMASS REMAINING
QUITE MOIST (AS INDICATED BY PERSISTENT 70F DWPTS)...THUS LOOK FOR
ANOTHER NIGHT OF LOW CLOUDS AND PERHAPS SOME FOG SETTING UP BETWEEN
03Z-06Z AND LINGERING THROUGH SUNRISE. PERSISTENCE FOR LOWS...AROUND
70 FOR MOST CENTRAL NC LOCALES.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
AS OF 235 PM SATURDAY...
THE RIDGE CENTERED OVER PA SUNDAY MORNING WILL BE THE PRIMARY...AND
MUCH ANTICIPATED INFLUENCE ON OUR WEATHER THROUGH THE SHORT TERM
PERIOD. THE DRYING TREND WILL ALREADY BE UNDERWAY AT THE START OF
THE PERIOD AND SHOULD CONTINUE THROUGH SUNDAY...BUT PRIMARILY ABOVE
THE BOUNDARY LAYER. AS SUCH...LOOK FOR SOME SUNSHINE IN THE
MORNING...FOLLOWING BY BUILDING CU IN THE AFTERNOON AS THE DAYTIME
HEATING PROGRESSES. FORECAST SOUNDINGS SUGGEST THAT THE CU MAY BUILD
ENOUGH TO SUPPORT A FEW SHOWERS AND PERHAPS AN ISOLD TSTM...THUS
WILL CARRY POPS OF 15-20 PERCENT (HIGHEST WEST) TO COVER THIS
POSSIBILITY. HOWEVER THIS IS STILL BELOW OUR CLIMATOLOGICAL POP FOR
THIS TIME OF YEAR. THICKNESSES AND FORECAST SOUNDINGS SUGGEST HIGHS
IN THE UPPER 80S TO NEAR 90.
FOR SUNDAY NIGHT...WITH SFC DPWTS STILL LINGERING AROUND 70...CAN`T
RULE OUT SOME FOG OR EVEN SOME LOW STRATUS EARLY MONDAY MORNING...
BUT SHOULDN`T BE AS WIDESPREAD AS PREV NIGHTS. LOWS IN THE UPPER 60S
TO LOWER 70S.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 305 AM SATURDAY...
A STRENGTHENING UPPER LEVEL RIDGE OVER THE MID-ATLANTIC STATES WILL
EXPAND ACROSS THE OHIO VALLEY REGION BY MONDAY...RESULTING IN A
DRYING AND WARMING TREND THROUGH THE UPCOMING WEEK. ANY SLIGHT
CHANCE OF STORMS MONDAY SHOULD BE FOCUSED NEAR AND SOUTH OF THE
NC/SC BORDER AREA AS THE MORE INSTABILITY AND BEST DEEP MOISTURE ARE
SHUNTED SOUTH. THEN ON TUESDAY...BOTH THE GFS AND ECMWF INDICATE
SOME ACTIVITY MAY DEVELOP ON THE EASTERN PERIPHERY OF THE UPPER
LEVEL HIGH IN THE VICINITY OF SURFACE AND 850-MB
TROUGHING....WHICH MAY EFFECT PORTIONS OF THE NORTHEAST CWA. THE
CENTER OF THE UPPER RIDGE IS FORECAST TO SHIFT SOUTH BY WEDNESDAY
SHOULD FURTHER CAP CONVECTION WEDNESDAY AND THURSDAY. BY THE END OF
THE WEEK...MODELS SHOW THE RIDGE WEAKENING OVER THE EAST
COAST...ALLOWING THE WESTERLIES TO DIP ACROSS THE NORTHEAST US AND A
MORE PROMINENT PIEDMONT TROUGH TO DEVELOP OVER OUR AREA...WHICH MAY
SUGGEST BETTER COVERAGE OF DIURNAL CONVECTION HEADING INTO THE
WEEKEND.
REGARDING TEMPS...AFTERNOON HIGHS WILL RETURN TO MORE SEASONAL
VALUES. GFS MOS VALUES IN THE EXTENDED SHOW A RAPID CLIMB INTO THE
MID 90S BY TUESDAY...WHICH SEEMS TOO WARM GIVEN THE POSITION OF THE
UPPER RIDGE TO OUR NORTH AND THE INCREASED SOIL MOISTURE NOW IN
PLACE ACROSS CENTRAL NC. INSTEAD...EXPECT HIGHS AROUND 90 MONDAY TO
INCREASE TO 91-93 BY MIDWEEK. LOWS IN THE LOWER 70S.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1250 PM SATURDAY...
WIDESPREAD MVFR AND ISOLD IFR CONDITIONS DUE TO LOW CIGS CONTINUES
ATTM WEST I-95 AND GENERALLY WEST OF THE WEAK COLD FRONT THAT IS
SLOWLY MOVING WWD. EAST OF I-95...CIGS ARE LIFTING IN THE WARM
SECTOR. IN ADDITION...SCATTERED SHOWERS AND ISOLD TSTM ARE LOCALLY
AND TEMPORARILY REDUCING VISIBILITIES. THIS WILL CONTINUE TO BE THE
TREND THROUGH MUCH OF THE AFTERNOON...WITH CIGS GRADUALLY LIFTING
FROM EAST TO WEST AS THE AFOREMENTIONED FRONT DRIFTS WEST. HOWEVER
SHOWER/TSTM ACTIVITY WILL CONTINUE AND MAY FURTHER INCREASE IN
COVERAGE THIS AFTERNOON AS THE BOUNDARY MOVES WEST AND WITH
ADDITIONAL HEATING. AFT 14/00Z...SHOWER/TSTM ACTIVITY IS EXPECTED TO
DIMINISH WITH LOSS OF HEATING...THEN CIGS WILL GRADUALLY LOWER
THROUGH THE REST OF THE NIGHT GIVEN THE MOIST AIRMASS IN PLACE. LOOK
FOR IFR/LIFR CONDITIONS TO RETURN TO MOST IF NOT ALL OF OUR TAF
SITES BETWEEN 14/03Z-14/06Z AND REMAIN UNTIL 14/13Z. AFT 14/13Z...
CIGS ARE EXPECTED TO RISE TO MVFR...AND TO VFR BY 14/18Z AS A MUCH
DRIER AIR MASS MOVES IN FROM THE EAST AND NORTHEAST.
LOOKING BEYOND...PATCHY MVFR/IFR CIGS ARE POSSIBLE LATE SUNDAY NIGHT
INTO MONDAY MORNING...OTHERWISE CONDITIONS ARE LIKELY TO REMAIN
MOSTLY VFR THROUGH WEDNESDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NP
NEAR TERM...NP
SHORT TERM...NP
LONG TERM...BLS
AVIATION...NP
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1118 AM MDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 947 AM MDT SAT JUL 13 2013
MADE A FEW MINOR CHANGES TO HOURLY POPS FOR TODAY HOWEVER THE REST
OF THE FORECAST IS ON TRACK SO NO CHANGES IN TEMPS OR WINDS.
LATEST SURFACE ANALYSIS HAS A BROAD AREA OF LOW PRESSURE ACROSS
SOUTHEASTERN MONTANA AND NORTHEASTERN WYOMING WITH ANOTHER AREA OF
LOW PRESSURE OVER CENTRAL SOUTH DAKOTA. SOME CONVECTION IS
BEGINNING TO FIRE IN SOUTHEASTERN WYOMING AND IN THE NEBRASKA
PANHANDLE. VISIBLE SATELLITE SHOWS SOME ACCAS TO THE EAST WITH
SOME CU/ACCAS OVER THE BEAR LODGE AND NORTHERN BLACK HILLS.
MAIN FORECAST CHALLENGE TODAY IS WHEN THE CONVECTION WILL DEVELOP
ACROSS THE CWA. LATEST HRRR MODEL DELAYS THE INITIATION UNTIL
LATER THIS AFTERNOON AS CONVECTION PROGRESS ONTO THE PLAINS FROM
THE HIGHER TERRAIN...HOWEVER HAVE SOME CONCERNS ON THIS TIMING DUE
TO THE AREA OF LOW PRESSURE ACOSS NORTHEASTERN WYOMING AND THE
DEVELOPING CU FIELD AROUND PHILLIP WITH THE RISUDUAL LOW OVER
CENTRAL SOUTH DAKOTA. THUS DECREASED THE POPS AROUND 18Z...BUT
EXPANDED AND INCREASED THE 21Z-00Z POPS ACROSS THE CWA.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 239 AM MDT SAT JUL 13 2013
08Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST MN TO
KICR TO WESTERN NE TO CENTRAL MT. TSRA ASSOCIATED WITH NOCTURNAL
PROCESSES OVER CENTRAL SD AND OVER NORTHWEST SD. ACTIVITY SHOULD
CONTINUE MOVING EAST EARLY THIS MORNING. FRONTAL BOUNDARY WILL
THEN BEGIN MOVING SLOWLY NORTH TODAY AND BECOME QUITE DIFFUSE
UNDER SOUTHWEST FLOW ALOFT. A COUPLE OF SHORTWAVES WILL MOVE
THROUGH CWA THIS AFTERNOON/EVENING UNDER RIGHT ENTRANCE REGION OF
70KT JET IN PLACE ALONG THE US/CANADIAN BORDER. MODERATE TO
LOCALLY STRONG INSTABILITY DEVELOPS NEAR FRONTAL
BOUNDARY...PARTICULARLY ON THE SD PLAINS. 0-6KM SHEAR
INCREASES...BUT ON THE MARGINAL SIDE FOR SUSTAINED SUPERCELLS.
EXPECT TSRA TO RAPIDLY INCREASE BY LATE THIS AFTERNOON AS MLCIN
ERODES...SPREADING EAST TONIGHT AS WEAK COOL FRONT DROPS OUT OF MT
INTO WESTERN PORTIONS OF CWA LATE. LARGE HAIL AND DAMAGING WIND
POSSIBLE. LOCALLY HEAVY RAIN POSSIBLE GIVEN PWAT/S FROM 100-150
PERCENT OF NORMAL...BUT STORM MOTION FROM 15-20KTS EXPECTED.
TEMPERATURES TODAY NEAR GUIDANCE.
SUNDAY...COOL FRONTAL BOUNDARY STALLS OVER CWA AS 850-300MB STEERING
FLOW BECOMES LESS THAN 10KTS. 0-6KM SHEAR BECOMES VERY WEAK...PWAT/S
RISE TO 125-175 PERCENT OF NORMAL WITH WELL-DEFINED MONSOONAL
MOISTURE PATTERN IN PLACE. SOUTHWEST FLOW ALOFT WILL KEEP ACTIVE
PATTERN GOING WITH CONVECTION LIKELY DEVELOPING EARLY...AND THUS
HAVE RAISED POPS/QPF. GIVEN EXPECTED SLOW STORM MOVEMENT...WILL PUT
MENTION OF LOCALLY HEAVY RAIN IN GRIDS AND HIGHLIGHT IN HWO. MAY
NEED A FLASH FLOOD WATCH WHEN ALL IS SAID AND DONE...BUT LATER
SHIFTS CAN PINPOINT AREAL THREAT. TEMPERATURES WILL BE NOTICEABLY
COOLER GIVEN CLOUD COVER/PRECIPITATION.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 239 AM MDT SAT JUL 13 2013
MONSOONAL FLOW PATTERN WILL REMAIN OVER THE REGION ON
MONDAY...BRINGING A CHANCE FOR THUNDERSTORMS. THERE LOOKS TO BE A
THREAT FOR STRONG TO SEVERE STORMS...ESPECIALLY ACROSS NORTHERN AND
WESTERN PORTIONS OF THE CWA...ALONG WITH LOCALLY HEAVY RAIN. A DRIER
PATTERN WILL DEVELOP FOR THE MIDDLE PORTION OF THE WEEK AS AN UPPER
LEVEL RIDGE BUILDS FURTHER NORTH ACROSS THE ROCKIES AND PLAINS AND
SHIFTS THE MONSOONAL MOISTURE PLUME TO THE NORTH AND WEST OF THE
AREA. CHANCES FOR THUNDERSTORMS WILL LIKELY RETURN BY THE END OF THE
WEEK AS THE RIDGE SLIDES FURTHER WESTWARD TOWARD THE WEST COAST
STATES...ALLOWING WEAK DISTURBANCES TO PASS OVER THE RIDGE AND
ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL BE NEAR AVERAGE LEVELS
ON MONDAY...WITH ABOVE AVERAGE TEMPERATURES THEN LIKELY THROUGH THE
REST OF THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1118 AM MDT SAT JUL 13 2013
VFR CONDITIONS ARE GENERALLY EXPECTED TODAY. SCATTERED SHOWERS
AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND PERSIST INTO
TONIGHT AS MONSOONAL MOISTURE REMAINS OVER THE REGION AND A WEAK
COLD FRONT MOVES INTO THE AREA. THE BETTER CHANCES LOOK TO BE FROM
THE BLACK HILLS AREA...EASTWARD INTO CENTRAL SD. A FEW STORMS
COULD BE SEVERE ACROSS THIS AREA DURING THE AFTERNOON AND EVENING
WITH HAIL AND GUSTY WINDS. BRIEF MVFR CONDITIONS ARE POSSIBLE IN
THE VICINITY OF ANY STRONGER STORMS THAT DEVELOP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...MLS
SHORT TERM...HELGESON
LONG TERM...26
AVIATION...15
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
1003 AM MDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 947 AM MDT SAT JUL 13 2013
MADE A FEW MINOR CHANGES TO HOURLY POPS FOR TODAY HOWEVER THE REST
OF THE FORECAST IS ON TRACK SO NO CHANGES IN TEMPS OR WINDS.
LATEST SURFACE ANALYSIS HAS A BROAD AREA OF LOW PRESSURE ACROSS
SOUTHEASTERN MONTANA AND NORTHEASTERN WYOMING WITH ANOTHER AREA OF
LOW PRESSURE OVER CENTRAL SOUTH DAKOTA. SOME CONVECTION IS
BEGINNING TO FIRE IN SOUTHEASTERN WYOMING AND IN THE NEBRASKA
PANHANDLE. VISIBLE SATELLITE SHOWS SOME ACCAS TO THE EAST WITH
SOME CU/ACCAS OVER THE BEAR LODGE AND NORTHERN BLACK HILLS.
MAIN FORECAST CHALLENGE TODAY IS WHEN THE CONVECTION WILL DEVELOP
ACROSS THE CWA. LATEST HRRR MODEL DELAYS THE INITIATION UNTIL
LATER THIS AFTERNOON AS CONVECTION PROGRESS ONTO THE PLAINS FROM
THE HIGHER TERRAIN...HOWEVER HAVE SOME CONCERNS ON THIS TIMING DUE
TO THE AREA OF LOW PRESSURE ACOSS NORTHEASTERN WYOMING AND THE
DEVELOPING CU FIELD AROUND PHILLIP WITH THE RISUDUAL LOW OVER
CENTRAL SOUTH DAKOTA. THUS DECREASED THE POPS AROUND 18Z...BUT
EXPANDED AND INCREASED THE 21Z-00Z POPS ACROSS THE CWA.
&&
.SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ISSUED AT 239 AM MDT SAT JUL 13 2013
08Z SURFACE ANALYSIS HAD FRONTAL BOUNDARY FROM NORTHWEST MN TO
KICR TO WESTERN NE TO CENTRAL MT. TSRA ASSOCIATED WITH NOCTURNAL
PROCESSES OVER CENTRAL SD AND OVER NORTHWEST SD. ACTIVITY SHOULD
CONTINUE MOVING EAST EARLY THIS MORNING. FRONTAL BOUNDARY WILL
THEN BEGIN MOVING SLOWLY NORTH TODAY AND BECOME QUITE DIFFUSE
UNDER SOUTHWEST FLOW ALOFT. A COUPLE OF SHORTWAVES WILL MOVE
THROUGH CWA THIS AFTERNOON/EVENING UNDER RIGHT ENTRANCE REGION OF
70KT JET IN PLACE ALONG THE US/CANADIAN BORDER. MODERATE TO
LOCALLY STRONG INSTABILITY DEVELOPS NEAR FRONTAL
BOUNDARY...PARTICULARLY ON THE SD PLAINS. 0-6KM SHEAR
INCREASES...BUT ON THE MARGINAL SIDE FOR SUSTAINED SUPERCELLS.
EXPECT TSRA TO RAPIDLY INCREASE BY LATE THIS AFTERNOON AS MLCIN
ERODES...SPREADING EAST TONIGHT AS WEAK COOL FRONT DROPS OUT OF MT
INTO WESTERN PORTIONS OF CWA LATE. LARGE HAIL AND DAMAGING WIND
POSSIBLE. LOCALLY HEAVY RAIN POSSIBLE GIVEN PWAT/S FROM 100-150
PERCENT OF NORMAL...BUT STORM MOTION FROM 15-20KTS EXPECTED.
TEMPERATURES TODAY NEAR GUIDANCE.
SUNDAY...COOL FRONTAL BOUNDARY STALLS OVER CWA AS 850-300MB STEERING
FLOW BECOMES LESS THAN 10KTS. 0-6KM SHEAR BECOMES VERY WEAK...PWAT/S
RISE TO 125-175 PERCENT OF NORMAL WITH WELL-DEFINED MONSOONAL
MOISTURE PATTERN IN PLACE. SOUTHWEST FLOW ALOFT WILL KEEP ACTIVE
PATTERN GOING WITH CONVECTION LIKELY DEVELOPING EARLY...AND THUS
HAVE RAISED POPS/QPF. GIVEN EXPECTED SLOW STORM MOVEMENT...WILL PUT
MENTION OF LOCALLY HEAVY RAIN IN GRIDS AND HIGHLIGHT IN HWO. MAY
NEED A FLASH FLOOD WATCH WHEN ALL IS SAID AND DONE...BUT LATER
SHIFTS CAN PINPOINT AREAL THREAT. TEMPERATURES WILL BE NOTICEABLY
COOLER GIVEN CLOUD COVER/PRECIPITATION.
&&
.LONG TERM...MONDAY THROUGH FRIDAY
ISSUED AT 239 AM MDT SAT JUL 13 2013
MONSOONAL FLOW PATTERN WILL REMAIN OVER THE REGION ON
MONDAY...BRINGING A CHANCE FOR THUNDERSTORMS. THERE LOOKS TO BE A
THREAT FOR STRONG TO SEVERE STORMS...ESPECIALLY ACROSS NORTHERN AND
WESTERN PORTIONS OF THE CWA...ALONG WITH LOCALLY HEAVY RAIN. A DRIER
PATTERN WILL DEVELOP FOR THE MIDDLE PORTION OF THE WEEK AS AN UPPER
LEVEL RIDGE BUILDS FURTHER NORTH ACROSS THE ROCKIES AND PLAINS AND
SHIFTS THE MONSOONAL MOISTURE PLUME TO THE NORTH AND WEST OF THE
AREA. CHANCES FOR THUNDERSTORMS WILL LIKELY RETURN BY THE END OF THE
WEEK AS THE RIDGE SLIDES FURTHER WESTWARD TOWARD THE WEST COAST
STATES...ALLOWING WEAK DISTURBANCES TO PASS OVER THE RIDGE AND
ACROSS THE NORTHERN PLAINS. TEMPERATURES WILL BE NEAR AVERAGE LEVELS
ON MONDAY...WITH ABOVE AVERAGE TEMPERATURES THEN LIKELY THROUGH THE
REST OF THE WEEK.
&&
.AVIATION...FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING
ISSUED AT 526 AM MDT SAT JUL 13 2013
VFR CONDITIONS ARE GENERALLY EXPECTED TODAY. SCATTERED SHOWERS
AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON AND PERSIST INTO
TONIGHT AS MONSOONAL MOISTURE REMAINS OVER THE REGION AND A WEAK
COLD FRONT MOVES INTO THE AREA. THE BETTER CHANCES LOOK TO BE FROM
THE BLACK HILLS AREA...EASTWARD INTO CENTRAL SD. A FEW STORMS
COULD BE SEVERE ACROSS THIS AREA DURING THE AFTERNOON AND EVENING
WITH HAIL AND GUSTY WINDS. BRIEF MVFR CONDITIONS ARE POSSIBLE IN
THE VICINITY OF ANY STRONGER STORMS THAT DEVELOP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
UPDATE...MLS
SHORT TERM...HELGESON
LONG TERM...26
AVIATION...26
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1248 PM CDT SAT JUL 13 2013
.UPDATE...
ISSUED AT 1102 AM CDT SAT JUL 13 2013
OVERNIGHT MCS ACROSS SOUTHERN MN AND NORTHERN IA HAS BEEN SLOWLY
DIMINISHING DURING THE PAST FEW HOURS...IN RESPONSE TO THE NORMAL
WEAKENING OF THE LOW LEVEL JET. THIS WEAKENING WAS DEFINITELY
EVIDENT ON THE WOOD LAKE PROFILER...WITH WESTERLY 850MB WINDS AT
08Z OF 45 KT AND AT 14Z OF 10 KT. ANTICIPATING THE WEAKENING OF
THE MCS TO CONTINUE OVER THE NEXT FEW HOURS. CLOUD COVER...ON THE
OTHER HAND...MAY TAKE ITS TIME CLEARING. THE MCS CLOUD IS SITUATED
RIGHT UNDERNEATH A 200-500MB RIDGE AXIS...WHICH MEANS THERE IS
LITTLE ADVECTIVE FLOW TO HELP CLEAR IT OUT. RAP 300MB WIND
FORECAST DOES SHOW A NORTHEAST WIND OVER CENTRAL/EASTERN WI AT
15Z...ON THE EAST SIDE OF THE RIDGE AXIS...TURNING MORE EASTERLY
THIS AFTERNOON. THIS WIND SWITCH SHOULD HELP TO AT LEAST PARTIALLY
CLEAR SKIES OUT OVER WISCONSIN. MEANWHILE...CLOUDS MAY GET STUCK
OVER SOUTHEAST MINNESOTA AND NORTHEAST IOWA AND THUS KEPT THIS
AREA MOSTLY CLOUDY THROUGH THE DAY. ADDITIONALLY...HAVE HAD TO
COOL HIGH TEMPERATURES A LITTLE MORE WEST OF THE MISSISSIPPI
RIVER TO ACCOUNT FOR MORE CLOUD. SHOULD CLOUDS CLEAR FASTER THAN
EXPECTED...TEMPERATURES WILL END UP WARMER.
ANOTHER ISSUE TO CONTEND WITH IS AN MCV THAT ORIGINATED OUT OF AN
MCS OVER WESTERN NEBRASKA LAST NIGHT. THIS MCV CAN BE SEEN ON
WATER VAPOR JUST EAST OF WATERTOWN SOUTH DAKOTA. DPVA AHEAD OF
THIS MCV...AN INCREASE OF 850-700MB MOISTURE TRANSPORT AHEAD OF
IT...AS WELL AS THE TRANSPORT ACTING ON 500-1000 J/KG OF MUCAPE
PER 13.14Z HRRR ANALYSIS HAS DEVELOPED SOME SHOWERS AND
THUNDERSTORMS OVER SOUTHWEST MN INTO THE BACK SIDE OF THE
WEAKENING MCS. AS THE MCV LIFTS NORTHEAST AROUND THE 500MB RIDGE
AXIS IN PLACE OVER THE FORECAST AREA...SOME OF THOSE
SHOWERS/THUNDERSTORMS COULD END UP CLIPPING SOUTHEAST MN DURING
THE AFTERNOON HOURS. AS A RESULT...ADDED A 20 PERCENT CHANCE OVER
SOUTHEAST MN FOR THE AFTERNOON. CERTAINLY THIS POTENTIAL ALSO
LEADS TO THE MORE PESSIMISTIC VIEW ON CLOUDS AND HIGHS TODAY.
FINALLY...13.14Z RAP AND 13.12Z NAM DEPICT A LITTLE DIFFERENT
850MB MOISTURE TRANSPORT LOCATION TONIGHT. THEY HAVE BOTH SHIFTED
THE OVERALL AXIS EAST...AIMED MORE AT CENTRAL MN VERSUS NORTHWEST
MN. IF THESE ARE CORRECT...THE COMBINATION OF THE OUTFLOW PRODUCED
BY THE ROUNDS OF SHOWERS/STORMS TODAY AND INSTABILITY OVER SIOUX
FALLS AREA COULD TRY TO INITIATE AN MCS OVER CENTRAL MN THIS
EVENING. CORFIDI VECTORS WHICH ARE NORTHERLY WOULD BRING THIS
TOWARDS THE FORECAST AREA. HOWEVER...THE 850MB MOISTURE TRANSPORT
AND INSTABILITY DRAMATICALLY DROPS OFF OVER THE FORECAST
AREA...SUGGESTING THE CONVECTION WOULD PROBABLY FALL APART.
ADDITIONALLY AND LIKELY CORRELATED...THE MCS MAINTENANCE
PROBABILITIES ARE VERY LOW SOUTH OF MINNEAPOLIS. THUS...HAVE KEPT
A DRY FORECAST FOR TONIGHT FOR NOW. SOMETHING TO WATCH.
UPDATE ISSUED AT 544 AM CDT SAT JUL 13 2013
CONVECTION CONTINUES TO TRACK TO THE EAST ALONG THE LEADING EDGE
OF THE LOW LEVEL MOISTURE TRANSPORT AND 0-3KM MUCAPE AXIS ACROSS
CENTRAL MINNESOTA AND NORTH CENTRAL IOWA. WHILE THE RAINFALL RATES
HAVE DISSIPATED ALONG THE FAR EASTERN PORTION OF THIS BAND...A
FAIRLY WIDESPREAD AREA OF MODERATE RAIN CONTINUES TO EXPAND
EASTWARD INTO WESTERN WISCONSIN. FURTHER
SOUTHWEST/WEST...CONVECTION PERSISTS NEAR THE TWIN CITIES AND
SOUTHWARD WHERE THE INSTABILITY REMAINS THE HIGHEST AT AROUND
500-1000 J/KG OF MUCAPE BASED ON 13.10Z RAP ANALYSIS. WITH THIS
AXIS OF INSTABILITY NOT MAKING MUCH PROGRESS EASTWARD THIS
MORNING...EXPECT THAT THE MORE IMPRESSIVE RADAR RETURNS WILL MAKE
IT MUCH FURTHER EAST. HOW FAR EAST THE MAIN BAND OF RAIN MAKES IT
CONTINUES TO BE THE MAIN QUESTION WITH THIS FORECAST AND WILL
UPDATE THE FORECAST THIS MORNING TO TAKE INTO ACCOUNT THIS SHIFT
FURTHER TO THE EAST OF THE RAIN BAND.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM CDT SAT JUL 13 2013
THE MAIN FOCUS THIS MORNING IS ON A BAND OF CONVECTION THAT HAS
PROPAGATED EAST ACROSS CENTRAL MINNESOTA THIS MORNING AND WHETHER
IT WILL GET INTO THE FORECAST AREA AND HOW IT COULD AFFECT
TEMPERATURES TODAY.
THIS CONVECTION HAS BEEN RUNNING FAIRLY STEADY TO THE EAST ACROSS
MINNESOTA ALONG THE NORTHERN PERIPHERY OF THE MID LEVEL RIDGE AND
ALONG THE EASTERN NOSE OF THE STRONGEST LOW LEVEL MOISTURE
TRANSPORT AND 0-3KM MUCAPE AXIS. THE QUESTION HAS BEEN WITH HOW
FAR EAST WILL IT MAKE IT AS PREVIOUS GUIDANCE HAS SUGGESTED THAT
ALL OF THE SUPPORT STALLS OUT WITH CONVECTION DYING OFF BEFORE IT
GETS INTO WESTERN WISCONSIN OR SOUTHEAST MINNESOTA.
WELL...THE LAST 6 HOURS OF RAP MODEL RUNS SHOW THE 850-925MB
MOISTURE TRANSPORT CONTINUING TO THE EAST THROUGH MID MORNING
THOUGH INSTABILITY WEAKENS OVER THIS TIME FRAME. RADAR TRENDS
OVER THE PAST HOUR OR SO SHOW THE LEADING EDGE DISSIPATING A
BIT...BUT THEN REDEVELOPING BEHIND IT/TO THE SOUTH. WITH THE MID
LEVEL RIDGE AXIS DRIFTING SOUTH...THINK THAT THESE
SHOWERS/THUNDERSTORMS WILL BE ABLE TO TRACK EAST INTO PORTIONS OF
SOUTHEAST MINNESOTA AND NORTH CENTRAL WISCONSIN AROUND/SHORTLY
AFTER DAYBREAK THIS MORNING. HOW LONG IT HANGS ON IS THE NEXT
QUESTION AS SOME GUIDANCE...SUCH AS THE 13.00Z NAM...SUGGEST THAT
AS THE PATTERN STALLS TODAY THE CONVECTION WILL ALSO STALL OUT
ACROSS SOUTHEAST MINNESOTA BEFORE THE RIDGE PIVOTS BACK NORTH.
KEPT PRECIPITATION CHANCES CONFINED TO THE EARLY TO MID MORNING
HOURS...BUT WILL HAVE TO MONITOR TRENDS TODAY.
WITH WEAK SHEAR AND INSTABILITY...AM NOT EXPECTING ANY SEVERE
WEATHER OUT OF THIS CONVECTION THIS MORNING OUTSIDE OF SOME BRIEF
HEAVY RAINS...IF IT HOLDS TOGETHER. ANOTHER MID LEVEL SHORT WAVE
TROUGH CURRENTLY IN NEBRASKA WILL ALSO TRACK EAST ALONG THE
NORTHERN EDGE OF THE MID LEVEL RIDGE AXIS THIS MORNING...BUT IS
NOT EXPECTED TO BRING ANY CONVECTION INTO THE REGION WITH IT.
THE OTHER ISSUE THAT THIS CONVECTION BRINGS WITH IT IS CLOUD COVER
WHICH SHOULD HELP TO KEEP TEMPERATURES DOWN A BIT TODAY. HAVE GONE
A BIT LOWER TODAY WITH HIGHS IN THE LOW 80S WITH THE EXPECTATION
THAT SOME AFTERNOON CLEARING WILL HELP TO GIVE A WINDOW OF A BRIEF
WARM UP. SOME LOW LEVEL WARM AIR ADVECTION OUT OF THE SOUTHEAST
WILL HELP TO PUSH THIS BOUNDARY BACK TO THE NORTH AND KEEP
CONDITIONS DRY INTO TONIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM CDT SAT JUL 13 2013
GOING INTO NEXT WEEK...THE MAIN FOCUS IS ON HOW HIGH TEMPERATURES
WILL BE AND PRECIPITATION CHANCES FROM MID WEEK ON.
A RETROGRADING MID LEVEL LOW RUNNING FROM THE OHIO RIVER VALLEY
WEST SOUTHWEST ACROSS THE SOUTHERN PLAINS WILL HELP TO STALL OUT
THE MID LEVEL FLOW WITH BROAD RIDGING SETTLING IN FROM THE PACIFIC
NORTHWEST EAST TOWARD THE MID ATLANTIC STATES. THE TREND HAS BEEN
TO BE A TAD COOLER ON 850/925MB TEMPERATURES SUNDAY INTO
TUESDAY...SO HAVE JUST KNOCKED OFF A DEGREE OR TWO THERE ON
HIGHS.
OTHERWISE...THE PRECIPITATION CHANCES REALLY ARE NOT ALL THAT HIGH
UNTIL THE NEXT COLD FRONT DROPS DOWN FROM THE NORTH THURSDAY NIGHT
INTO FRIDAY. AHEAD OF THAT ON TUESDAY/WEDNESDAY/THURSDAY...BOTH
THE 13.00Z GFS AND ECMWF SHOW SOME AFTERNOON THUNDERSTORMS
DEVELOPING THOUGH FORCING IS FAIRLY WEAK. CAN NOT COMPLETELY RULE
OUT SOME ISOLATED CONVECTION DEVELOPING...SO HAVE LEFT THOSE
CHANCES IN FOR NOW. THE BEST CHANCE WILL COME IN WITH THE COLD
FRONT ON FRIDAY WITH THE 13.00Z GFS/ECMWF COMING INTO AGREEMENT ON
THAT TIMING FOR NOW. STILL PRETTY FAR OUT TO GET ANY DETAILS ON SEVERE
WEATHER POSSIBILITIES WITH THIS FEATURE...BUT WITH AN UNSTABLE
ENVIRONMENT AND A FRONT COMING THROUGH DURING PEAK HEATING...CAN
NOT RULE OUT THE POSSIBILITY OF SEVERE WEATHER ON FRIDAY SHOULD
THESE TRENDS CONTINUE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1248 PM CDT SAT JUL 13 2013
ADDITIONAL SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS SOUTHWEST
MINNESOTA WILL ADVANCE EASTWARD THROUGH THE AFTERNOON...AND COULD
IMPACT KRST BY 22Z. AT THIS POINT...CONFIDENCE ISN/T TOO GREAT
WHETHER IT WILL HOLD TOGETHER OR MISS THE TAF SITE ALTOGETHER SO
HAVE INCLUDED VICINITY SHOWER GROUP FOR A PERIOD. CONDITIONS
EXPECTED TO REMAIN VFR HOWEVER AS IT COMES THROUGH. SCATTERED TO
BROKEN CONVECTIVE DEBRIS CLOUDS WILL LINGER THROUGH EARLY
EVENING...THEN FOCUS TURNS TO ANY FOG OR STRATUS DEVELOPMENT
OVERNIGHT. GIVEN RECENT RAIN...CLOUDS...AND COOLER
TEMPERATURES...SETUP IS MORE FAVORABLE. HOWEVER COMPETING
NEGATIVE FACTOR REMAINS THE TIGHT PRESSURE GRADIENT WITH SURFACE
WINDS UP TO 1-2 KM EXPECTED TO REMAIN AROUND 10 KTS THROUGH THE
NIGHT. THE GRADIENT DOES RELAX BY 10-12Z SUNDAY MORNING...AND
THIS COULD BE ENOUGH TO ALLOW PATCHY FOG/STRATUS TO DEVELOP. FOR
NOW...INCLUDED A BRIEF PERIOD OF MVFR VISIBILITY. WILL HAVE TO
MONITOR TRENDS CLOSELY THIS EVENING TO SEE IF WINDS SUBSIDE MORE
THAN EXPECTED...AND IF SO IFR CONDITIONS COULD BE NEEDED SIMILAR
TO WHAT SOME OF THE GUIDANCE IS SUGGESTING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...HALBACH
LONG TERM....HALBACH
AVIATION...ZT