Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/15/13
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 DENVER/BOULDER CO
910 PM MDT SUN JUL 14 2013
.UPDATE...
&&
.SHORT TERM...SO FAR THINGS REALLY HAVEN`T DEVELOPED LIKE
EXPECTED. LOW TOPPED CONVECTION HAS FINALLY STARTED TO DVLP OVER
THE HIGHER FOOTHILLS AND MTNS. OVER THE PLAINS THERE IS NOT MUCH
ACTIVITY AT THIS POINT. SOUNDING SHOWS POTENTIAL FOR WARM CORE
LOW TOPPED CONVECTION OVERNIGHT WHICH COULD STILL DUMP UP TO AN
INCH OF RAIN IN 30 MINUTES OR LESS IN A FEW LOCATIONS HOWEVER AT
THIS POINT WIDESPREAD HEAVY RAIN DOES NOT LOOK LIKELY. WILL KEEP
FFA OUT THROUGH MIDNIGHT WITH ECHOES NOW DEVELOPING OVER THE
HIGHER TERRAIN AND SEE HOW THINGS GO THE NEXT FEW HOURS.
.AVIATION...ACTIVITY HAS PRETTY MUCH ENDED. OVERALL LATEST HRRR
REALLY DOES NOT SHOW MUCH THRU 09Z WITH A CHC OF SHOWERS IN THE
09Z-13Z TIMEFRAME. PROSPECTS FOR FOG AROUND SUNRISE WILL PROBABLY
DEPEND ON WHETHER THESE SHOWERS OCCUR OR NOT. HRRR DOES SHOW A WK
DENVER CYCLONE WITH LIGHT NW WINDS AT DIA SO IF SHOWERS FAIL TO
DVLP THEN COULD SEE SOME LOCALLY DENSE FOG IN THE 12Z-15Z PERIOD.
&&
.HYDROLOGY...FFA WILL CONTINUE THRU MIDNIGHT. COULD SEE LOCALLY
HEAVY RAIN UP TO AN INCH IN 30 MINUTES IN A FEW SPOTS BUT
WIDESPREAD HEAVY RAIN DOES NOT LOOK LIKELY AT THIS POINT.
&&
.PREV DISCUSSION... /ISSUED 313 PM MDT SUN JUL 14 2013/
SHORT TERM...CONVECTION SLOW TO GET GOING OVER THE PLAINS SAVE THE
NORTHEAST CORNER. THERE IS FAIR COVERAGE OVER THE MOUNTAINS AND
FOOTHILLS. THE CELLS ARE MOVING IN ABOUT EVERY DIRECTION THERE IS
DEPENDING ON WHAT PART OF THE CWA YOUR IN. THE ACARS SOUNDINGS
POINT TO 79 F TO INITIATE CONVECTION ON THE PLAINS. THE DIA
TEMPERATURES IS RIGHT AROUND THAT RIGHT NOW. DEW POINTS STILL IN
THE 60S F EVERYWHERE OVER THE PLAINS AND LOWER FOOTHILLS. MODELS
PUSH THE UPPER HIGH CENTER OVER WESTERN COLORADO TONIGHT AND
MONDAY WITH UPPER LOW TO BE CENTERED OVER THE TEXAS PANHANDLE AT
00Z LATE MONDAY AFTERNOON. THE FLOW ALOFT OVER OUR CWA WILL BE
WEAK AND NORTH-NORTHEASTERLY OVERNIGHT INTO MONDAY. THERE IS
STILL WEAK UPWARD QG VERTICAL VELOCITY PROGGED FOR THE CWA TONIGHT
AND MONDAY. THE BOUNDARY LAYER FLOW WILL BE NORTHEASTERLY THIS
EVENING...THEN EAST AND SOUTHEASTERLY OVERNIGHT AND MONDAY. THE
MOISTURE STAYS HIGH TONIGHT INTO MONDAY. PRECIPITABLE WATER VALUES
STAY OVER 1.00 INCH BOTH PERIODS. BOUNDARY LAYER DEW POINTS STAY
ABOVE 60 F OVER THE PLAINS TONIGHT AND MONDAY MONRING...THEN THEY
DRY OUT SOMEWHAT. THE QPF FIELDS SHOW QUITE A BIT OF MEASURABLE
PRECIPITATION OVER THE CWA THIS EVENING AND OVERNIGHT. ON MONDAY
MORNING THE WESTERN HALF OF THE CWA HAS MEASURABLE RAINFALL
OVERNIGHT...THEN THE MOUNTAINS AND FOOTHILLS ONLY MONDAY
AFTERNOON. FOR POPS...WILL STAY WITH "LIKELY"S THIS EVENING
ANYWAY. WILL KEEP THE FLASH FLOOD WATCH GOING FOR THE FOOTHILLS.
HEAVY RAIN IS A GOOD BET. FOR TEMPERATURES...MONDAY`S HIGH`S
SHOULD BE 0-2 C WARMER THAN THIS AFTERNOON`S.
LONG TERM...SUBSIDENCE WILL TAKE HOLD OVER ALL OF THE FORECAST
AREA BY MONDAY EVENING WITH ANY LINGERING STORMS IN THE HIGH
COUNTRY COMING TO AN END.
FOR TUESDAY AND WEDNESDAY...THE AIRMASS WILL GRADUALLY WARM AND
DRY BUT ENOUGH WARMING ALOFT WILL KEEP THE PLAINS CAPPED AND FREE
OF CONVECTION. MEANWHILE...THE MOUNTAINS SHOULD SEE A GRADUAL
INCREASE IN STORM COVERAGE AS THE AIRMASS DESTABILIZES OVER THE
HIGHER TERRAIN.
BY THURSDAY...THE MOISTURE SHOULD BEGIN TO POOL AGAIN UNDER THE
UPPER LEVEL RIDGE. HARD TO SAY IF THERE WILL BE ENOUGH WESTERLY
COMPONENT TO BRING ANY STORMS OFF THE HIGHER TERRAIN...BUT THE
AIRMASS WILL CONTINUE TO WARM ON THE PLAINS WITH A WEAKENING CAP.
FOR NOW...THE SLIGHT CHANCE OF STORMS LOOKS GOOD.
FOR FRIDAY...MOST MEDIUM RANGE MODELS SUGGEST A WEAK FRONT TO BACK
ACROSS THE PLAINS WITH INCREASING LOW LEVEL MOISTURE AND
INSTABILITY. THIS WOULD LEAD TO SLIGHT COOLING ALONG WITH A BETTER
CHANCE OF STORMS...SOME WHICH COULD PRODUCE HEAVY RAINFALL. SEE
LITTLE CHANGE FOR THE UPCOMING WEEKEND WITH POTENTIAL FOR WEAK
FRONTS AND/OR SHORT WAVES IN LIGHT WEST/NORTHWEST FLOW ALOFT. FEEL
A CLIMATOLOGY APPROACH TO THOSE FORECAST PERIODS IS WARRANTED AT
THIS TIME WITH A SLIGHT CHANCE OF STORMS AND NEAR NORMAL
TEMPERATURES.
AVIATION...THE CONVECTION IS SLOW TO GET GOING. CURRENT TAF NOW
HAS THE TSRA TEMPO GROUP AT 22Z. MOST OF THE MODELS POINT TO
PRETTY LOW CEILINGS TONIGHT INTO MONDAY. SEE CURRENT TAF. MODELS
ALSO SHOW RAIN MUCH OF THE NIGHT INTO MONDAY MORNING.
HYDROLOGY...THE HEAVIEST STORMS COULD PRODUCE RAINFALL AMOUNTS UP
TO TWO INCH IN ONE HOUR. THE BURNED AREAS WILL BE ESPECIALLY
SUSCEPTIBLE TO FLOODING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ035-036.
&&
$$
SHORT TERM...RJK
LONG TERM....BARJENBRUCH
AVIATION...RPK
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 MIAMI FL
1133 PM EDT SUN JUL 14 2013
.UPDATE...THE NEAR TERM FORECAST WAS JUST UPDATED. RADAR TRENDS
SUGGEST WIDESPREAD ACTIVITY WILL AFFECT THE PALM BEACHES OVER THE
NEXT HOUR OR SO, EVEN THOUGH THERE IS A GENERAL WEAKENING TREND IN
THE CONVECTION. FURTHER DOWN THE COAST, IT REMAINS TO BE SEEN HOW
MUCH ACTIVITY WILL MOVE INLAND OVERNIGHT. WINDS ARE LIGHT BUT THE
EASTERLY FLOW IMPINGING INTO THE AREA COULD ALLOW FOR SOME SHRA OR
TSTORMS TO MOVE ONSHORE OVERNIGHT. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 920 PM EDT SUN JUL 14 2013/
UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE SOUTH FLORIDA AREA THIS EVENING WITH SLIGHTLY MORE ORGANIZED
CONVECTION ACROSS THE GULF WATERS. LATEST HRRR CONTINUES TO DEPICT
ACTIVITY WEAKENING THROUGH THE NEXT FEW HOURS. ADJUSTED POP AND
QPF GRIDS SLIGHTLY. UPDATE SENT.
PREV DISCUSSION... /ISSUED 800 PM EDT SUN JUL 14 2013/
AVIATION...
SHORTWAVE RIDGE BUILDING SOUTH OF EAST CST FL AS MODELS HAVE BEEN
ADVERTISING. CURRENTLY HAS YET TO SET IN ACROSS S FL TO PUSH
STORMS WEST. HENCE ACTIVITY INLAND ENDED UP PROPAGATING INTO THE
EAST COAST THIS EVENING. THIS EVENING WILL BE SEEING SOME DIMINISHING TS
OVERNIGHT ALONG EAST COAST TERMINALS WITH BRIEF PERIODS OF MVFR
CIG/VIS NEXT COUPLE OF HOURS AND EVEN VERY BRIEF IFR. OTHERWISE
VFR CONDITIONS THROUGH TOMORROW EVENING OUTSIDE DIMINISHING CHANCES
OF SHOWERS OR STORMS AFFECTING ANY GIVEN TERMINAL AS OUTLINED
NEXT.
GOING DRY FOR A SPELL OVERNIGHT. MESOANALYSIS SHOW AN AREA OF DRY
LOW LEVEL AIR TRYING TO MOVE WEST FROM BAHAMAS BUT WEAKENS AND
OTHERWISE DOESN`T QUITE MAKE IT. SOME SHRA MAY REDEVELOP COASTAL
WATERS AND THINK CHANCES ARE BETTER DURING THE LATE OVERNIGHT
PERIOD FOR EASTERN TERMINALS WHERE LOW LEVEL FLOW SHOULD BE A
LITTLE STRONGER. THIS IS ALL INDICATIVE OF AREA TRANSITIONING TO A
MORE TYPICAL EASTERLY FLOW PATTERN AND WITH THAT WILL MENTION VCSH
OVERNIGHT INTO LATE TOMORROW MORNING OR VERY EARLY AFTERNOON. WITH
LOW LEVEL RIDGE BUILDING IN, ACTIVITY SHOULD TRANSITION AND STAY
INLAND TOMORROW AFTERNOON SO WILL LEAVE VCSH OR VCTS OUT OF THE SE
TERMINALS FOR TOMORROW AFTERNOON EXCEPT AT PBI AND FXE. FOR APF,
ADDED VCSH AND VCTS FROM LATE MORNING ON.
SFC WIND...DCRG EAST FLOW LATE EVENING BCMG ENE AROUND 7KT OR LESS
ALL TERMINALS OVERNIGHT. TOMORROW EAST 7-12KT BY 14-16Z ALL SITES.
PREV DISCUSSION... /ISSUED 241 PM EDT SUN JUL 14 2013/
DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
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.
BY THE MIDDLE OF THE WEEK 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 WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN 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. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
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 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 AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 76 88 / 80 20 10 30
FORT LAUDERDALE 72 88 79 89 / 60 30 20 30
MIAMI 73 89 78 89 / 60 30 20 30
NAPLES 71 88 73 92 / 50 50 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
920 PM EDT SUN JUL 14 2013
.UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE SOUTH FLORIDA AREA THIS EVENING WITH SLIGHTLY MORE ORGANIZED
CONVECTION ACROSS THE GULF WATERS. LATEST HRRR CONTINUES TO DEPICT
ACTIVITY WEAKENING THROUGH THE NEXT FEW HOURS. ADJUSTED POP AND
QPF GRIDS SLIGHTLY. UPDATE SENT.
&&
.PREV DISCUSSION... /ISSUED 800 PM EDT SUN JUL 14 2013/
AVIATION...
SHORTWAVE RIDGE BUILDING SOUTH OF EAST CST FL AS MODELS HAVE BEEN
ADVERTISING. CURRENTLY HAS YET TO SET IN ACROSS S FL TO PUSH
STORMS WEST. HENCE ACTIVITY INLAND ENDED UP PROPAGATING INTO THE
EAST COAST THIS EVENING. THIS EVENING WILL BE SEEING SOME DIMINISHING TS
OVERNIGHT ALONG EAST COAST TERMINALS WITH BRIEF PERIODS OF MVFR
CIG/VIS NEXT COUPLE OF HOURS AND EVEN VERY BRIEF IFR. OTHERWISE
VFR CONDITIONS THROUGH TOMORROW EVENING OUTSIDE DIMINISHING CHANCES
OF SHOWERS OR STORMS AFFECTING ANY GIVEN TERMINAL AS OUTLINED
NEXT.
GOING DRY FOR A SPELL OVERNIGHT. MESOANALYSIS SHOW AN AREA OF DRY
LOW LEVEL AIR TRYING TO MOVE WEST FROM BAHAMAS BUT WEAKENS AND
OTHERWISE DOESN`T QUITE MAKE IT. SOME SHRA MAY REDEVELOP COASTAL
WATERS AND THINK CHANCES ARE BETTER DURING THE LATE OVERNIGHT
PERIOD FOR EASTERN TERMINALS WHERE LOW LEVEL FLOW SHOULD BE A
LITTLE STRONGER. THIS IS ALL INDICATIVE OF AREA TRANSITIONING TO A
MORE TYPICAL EASTERLY FLOW PATTERN AND WITH THAT WILL MENTION VCSH
OVERNIGHT INTO LATE TOMORROW MORNING OR VERY EARLY AFTERNOON. WITH
LOW LEVEL RIDGE BUILDING IN, ACTIVITY SHOULD TRANSITION AND STAY
INLAND TOMORROW AFTERNOON SO WILL LEAVE VCSH OR VCTS OUT OF THE SE
TERMINALS FOR TOMORROW AFTERNOON EXCEPT AT PBI AND FXE. FOR APF,
ADDED VCSH AND VCTS FROM LATE MORNING ON.
SFC WIND...DCRG EAST FLOW LATE EVENING BCMG ENE AROUND 7KT OR LESS
ALL TERMINALS OVERNIGHT. TOMORROW EAST 7-12KT BY 14-16Z ALL SITES.
PREV DISCUSSION... /ISSUED 241 PM EDT SUN JUL 14 2013/
DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
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.
BY THE MIDDLE OF THE WEEK 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 WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN 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. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
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 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 AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 76 88 / 50 20 10 30
FORT LAUDERDALE 73 88 79 89 / 60 30 20 30
MIAMI 74 89 78 89 / 60 30 20 30
NAPLES 71 88 73 92 / 50 50 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...52/PS
AREA FORECAST DISCUSSION
NWS MIAMI FL
800 PM EDT SUN JUL 14 2013
.AVIATION...
SHORTWAVE RIDGE BUILDING SOUTH OF EAST CST FL AS MODELS HAVE BEEN
ADVERTISING. CURRENTLY HAS YET TO SET IN ACROSS S FL TO PUSH
STORMS WEST. HENCE ACTIVITY INLAND ENDED UP PROPAGATING INTO THE
EAST COAST THIS EVENING. THIS EVENING WILL BE SEEING SOME DIMINISHING TS
OVERNIGHT ALONG EAST COAST TERMINALS WITH BRIEF PERIODS OF MVFR
CIG/VIS NEXT COUPLE OF HOURS AND EVEN VERY BRIEF IFR. OTHERWISE
VFR CONDITIONS THROUGH TOMORROW EVENING OUTSIDE DIMINISHING CHANCES
OF SHOWERS OR STORMS AFFECTING ANY GIVEN TERMINAL AS OUTLINED
NEXT.
GOING DRY FOR A SPELL OVERNIGHT. MESOANALYSIS SHOW AN AREA OF DRY
LOW LEVEL AIR TRYING TO MOVE WEST FROM BAHAMAS BUT WEAKENS AND
OTHERWISE DOESN`T QUITE MAKE IT. SOME SHRA MAY REDEVELOP COASTAL
WATERS AND THINK CHANCES ARE BETTER DURING THE LATE OVERNIGHT
PERIOD FOR EASTERN TERMINALS WHERE LOW LEVEL FLOW SHOULD BE A
LITTLE STRONGER. THIS IS ALL INDICATIVE OF AREA TRANSITIONING TO A
MORE TYPICAL EASTERLY FLOW PATTERN AND WITH THAT WILL MENTION VCSH
OVERNIGHT INTO LATE TOMORROW MORNING OR VERY EARLY AFTERNOON. WITH
LOW LEVEL RIDGE BUILDING IN, ACTIVITY SHOULD TRANSITION AND STAY
INLAND TOMORROW AFTERNOON SO WILL LEAVE VCSH OR VCTS OUT OF THE SE
TERMINALS FOR TOMORROW AFTERNOON EXCEPT AT PBI AND FXE. FOR APF,
ADDED VCSH AND VCTS FROM LATE MORNING ON.
SFC WIND...DCRG EAST FLOW LATE EVENING BCMG ENE AROUND 7KT OR LESS
ALL TERMINALS OVERNIGHT. TOMORROW EAST 7-12KT BY 14-16Z ALL SITES.
&&
.PREV DISCUSSION... /ISSUED 241 PM EDT SUN JUL 14 2013/
DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
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.
BY THE MIDDLE OF THE WEEK 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 WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN 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. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
AVIATION...
THE PERIOD BEGINS WITH MAINLY LINGERING LIGHT RAIN OVER THE APF
TERMINAL AS MOST OF THE HEAVIER ACTIVITY HAS SHIFTED INLAND FROM
COLLIER TO GLADES COUNTY. THE LATEST HRRR MODEL REFLECTIVITY SHOW
THE BULK OF THE AFTERNOON ACTIVITY CONTINUING TO DEVELOP OVER THE
INTERIOR AND NORTHERN AREAS THROUGH THE REMAINDER OF THE AFTERNOON
HOURS. FOR NOW...WE WILL CONTINUE TO CARRY VCTS ALONG THE EAST COAST
AND UPDATE AS CONDITIONS EVOLVE. THIS ACTIVITY SHOULD WEAKEN AND
TREND DOWN THROUGH THE OVERNIGHT HOURS TONIGHT WITH LIGHT EASTERLY
FLOW RETURNING ACROSS THE AREA. LIGHT TO MODERATE EASTERLY FLOW ON
MONDAY SHOULD TRANSLATE TO THE AFTERNOON ACTIVITY SETTING UP INLAND
OF THE EAST COAST ACROSS THE INTERIOR AND GULF COAST THROUGH THE
AFTERNOON HOURS.
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 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 AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 73 87 76 88 / 60 20 10 30
FORT LAUDERDALE 73 88 79 89 / 50 30 20 30
MIAMI 74 89 78 89 / 60 30 20 30
NAPLES 71 88 73 92 / 40 50 20 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...10/CD
AVIATION/RADAR...52/PS
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
NWS PEACHTREE CITY GA
824 PM EDT SUN JUL 14 2013
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
LOW PRESSURE IS MOVING WEST ACROSS THE FLORIDA PANHANDLE THIS
EVENING. SHOWERS AND THUNDERSTORMS HAVE DIMINISHED ACROSS THE CWFA
DURING THE LAST HOUR AND HAVE UPDATED POPS TO REFLECT THIS TREND.
IN ADDITION...SINCE ACTIVITY HAS DWINDLED AND RAINFALL RATES HAVE
DECREASED...HAVE DROPPED THE FF WATCH.
THE CHANCES FOR THUNDER WILL CONTINUE TO DIMINISH THROUGH
10PM...BUT ISOLD SHRA WILL BE POSSIBLE DURING THE OVERNIGHT HOURS.
ALSO ADDED PATCHY FOG TO THE FORECAST.
NLISTEMAA
&&
.PREV DISCUSSION... /ISSUED 725 PM EDT SUN JUL 14 2013/
PREV DISCUSSION... /ISSUED 344 PM EDT SUN JUL 14 2013/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
SHOWERS HAVE BECOME MORE WIDESPREAD AND SHOULD CONTINUE TO ADVECT
WESTWARD WITH EMBEDDED THUNDERSTORMS INTO THIS EVENING. SHORT TERM
HI-RES GUIDANCE IS IN GOOD AGREEMENT WITH EVOLUTION OF CONVECTION
AND ACTIVITY SHOULD DIMINISH ACROSS EASTERN PORTIONS OF CWA AFTER
ABOUT 03Z. ISOLATED DEVELOPMENT IS STILL POSSIBLE THROUGH THE
OVERNIGHT. WITH PWATS OF NEAR 2.0 INCHES IN MAIN BAND OF ENHANCED
MOISTURE...PRECIP EFFICIENCY WILL BE QUITE HIGH WITH DEVELOPMENT AND
WILL NOT TAKE MUCH TO CAUSE FLASH FLOODING IN ALREADY SATURATED
SOILS. HAVE EXPANDED CURRENT FLASH FLOOD WATCH ACROSS ALL OF NORTH
GEORGIA BASED ON PROGGED PRECIP COVERAGE...SEE HYDROLOGY SECTION
BELOW FOR MORE DETAILS. MLCAPE VALUES HAVE BEEN LIMITED TO NEAR 1000
J/KG OR LESS WITH AMPLE MORNING CLOUD COVERAGE...THOUGH SOME
SCATTERING OF THE CU FIELD HAS OCCURRED ACROSS WESTERN PORTIONS
RECENTLY SO THAT AREA MAY VERY WELL SEE BEST CHANCE FOR TS.
AS UPPER LOW CONTINUES TO HAVE UNUSUALLY QUICK RETROGRADING ACROSS
THE SOUTHEAST CONUS...THE ASSOCIATED BAND OF DEEP LAYER MOISTURE
WILL BE WEST OF AREA BY MONDAY MORNING AND UPPER RIDGE WILL BEGIN TO
BUILD IN FROM NORTHEAST. THERE WILL STILL BE LINGERING MOISTURE
PRIMARILY IN THE SOUTHERN PORTION OF THE AREA THEREFORE HAVE GONE
WITH CHANCE TO SLIGHT POPS FOR SHOWERS AND THUNDERSTORMS WITH HIGHER
CHANCE ACROSS CENTRAL GA BY AFTERNOON INTO EVENING. CHANCES LOOK TO
DIMINISH AFTER MIDNIGHT.
FOR TEMPS...GENERAL BLEND OF GUIDANCE LOOKS REASONABLE WITH NEAR
NORMAL LOWS AND APPRX 3-5 DEGREE BELOW NORMAL HIGHS.
BAKER
HYDROLOGY...
AMPLE MOISTURE AND ASSOCIATED NUMEROUS SHOWERS WITH EMBEDDED
THUNDERSTORMS WILL ALLOW FOR ADDITIONAL PRECIPITATION AREA-WIDE
THROUGH THIS AFTERNOON AND INTO THE EVENING BEFORE ACTIVITY
DIMINISHES FROM THE EAST BY LATE EVENING. WHILE A WIDESPREAD
0.5-0.75 INCHES IS LIKELY...ANY TRAINING OF STORMS CAN CAUSE LOCAL
AMOUNTS OF 1-2 INCHES TO FALL QUICKLY AND BECOME INSTANT RUNOFF.
HAVE THEREFORE CONTINUED CURRENT FLASH FLOOD WATCH AND EXPANDED
ACROSS ALL OF NORTH GEORGIA UNTIL 10 PM THIS EVENING.
BAKER
LONG TERM /TUESDAY THROUGH SUNDAY/...
NO SIG CHANGES WERE MADE TO THE EXTENDED. AT THIS TIME THE CURRENT
FORECAST APPEARS TO BE ON TRACK. ONLY TWEAKED SOME HIGHS AND LOWS
SLIGHTLY IN THE EXTENDED AND LOADED IN THE LATEST WIND AND
DEWPOINT DATA INTO THE EXTENDED. HAVE ATTACHED PREVIOUS DISCUSSION FOR
BREVITY.
ARG
PREV DISCUSSION... /ISSUED 211 PM EDT SUN JUL 14 2013/
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE ALOFT WILL BE OVER THE OH-MID MS VALLEY TO START THE
LONG TERM. A MOIST AIRMASS WILL STILL BE IN PLACE AS A DEEP EASTERLY
FLOW PATTERN PERSISTS. THIS SHOULD ALLOW A MORE DIURNAL TENDENCY TO
ANY CONVECTION MONDAY NIGHT AND TUESDAY.
THIS PATTERN LOOKS TO CONTINUE ON WEDNESDAY EXCEPT GUIDANCE HINTING
AT AN EASTERLY WAVE TO MOVE ACROSS THE AREA TENDING TO AFFECT N GA
MORE THAN CENTRAL. SIMILAR PATTERN CONTINUES FOR THURSDAY AND FRIDAY
WITH THE UPPER RIDGE WEAKENING ON FRIDAY AND THE UPPER FLOW BECOMING
MORE WSW FOR SATURDAY INTO SUNDAY. AT LEAST SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THROUGH SUNDAY FOR
MUCH OF THE AREA. ALL IN ALL TEMPERATURES SHOULD GENERALLY BE CLOSE
TO NORMAL.
BDL
AVIATION...
00Z UPDATE...
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE ACROSS THE
REGION THIS EVENING. LATEST RUNS OF THE HRRR SHOW MOST CONVECTION
DIMINISHING BY 02Z. GOOD EASTERLY FLOW TONIGHT SHOULD HELP WITH A
LOWER DECK OF IFR STRATUS DEVELOP AROUND/AFTER 06Z. PATCHY MVFR
FOG WILL ALSO BE AN ISSUE. DIURNAL CU IS EXPECTED TOMORROW AFTERNOON.
THE CHANCES FOR PRECIP ARE TOO LOW TO MENTION AT THIS TIME.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE CIGS/VBYS. HIGH CONFIDENCE REMAINING ELEMENTS.
NLISTEMAA
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 85 70 91 / 40 30 20 20
ATLANTA 69 84 71 88 / 40 30 30 20
BLAIRSVILLE 66 84 65 86 / 40 20 20 20
CARTERSVILLE 70 85 70 90 / 50 30 20 20
COLUMBUS 72 86 72 90 / 30 40 30 30
GAINESVILLE 69 83 71 89 / 40 30 20 20
MACON 71 86 70 90 / 30 40 30 30
ROME 70 87 70 90 / 50 30 30 20
PEACHTREE CITY 70 84 68 88 / 40 40 30 20
VIDALIA 72 86 72 90 / 20 40 20 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
725 PM EDT SUN JUL 14 2013
.PREV DISCUSSION... /ISSUED 344 PM EDT SUN JUL 14 2013/
SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
SHOWERS HAVE BECOME MORE WIDESPREAD AND SHOULD CONTINUE TO ADVECT
WESTWARD WITH EMBEDDED THUNDERSTORMS INTO THIS EVENING. SHORT TERM
HI-RES GUIDANCE IS IN GOOD AGREEMENT WITH EVOLUTION OF CONVECTION
AND ACTIVITY SHOULD DIMINISH ACROSS EASTERN PORTIONS OF CWA AFTER
ABOUT 03Z. ISOLATED DEVELOPMENT IS STILL POSSIBLE THROUGH THE
OVERNIGHT. WITH PWATS OF NEAR 2.0 INCHES IN MAIN BAND OF ENHANCED
MOISTURE...PRECIP EFFICIENCY WILL BE QUITE HIGH WITH DEVELOPMENT AND
WILL NOT TAKE MUCH TO CAUSE FLASH FLOODING IN ALREADY SATURATED
SOILS. HAVE EXPANDED CURRENT FLASH FLOOD WATCH ACROSS ALL OF NORTH
GEORGIA BASED ON PROGGED PRECIP COVERAGE...SEE HYDROLOGY SECTION
BELOW FOR MORE DETAILS. MLCAPE VALUES HAVE BEEN LIMITED TO NEAR 1000
J/KG OR LESS WITH AMPLE MORNING CLOUD COVERAGE...THOUGH SOME
SCATTERING OF THE CU FIELD HAS OCCURRED ACROSS WESTERN PORTIONS
RECENTLY SO THAT AREA MAY VERY WELL SEE BEST CHANCE FOR TS.
AS UPPER LOW CONTINUES TO HAVE UNUSUALLY QUICK RETROGRADING ACROSS
THE SOUTHEAST CONUS...THE ASSOCIATED BAND OF DEEP LAYER MOISTURE
WILL BE WEST OF AREA BY MONDAY MORNING AND UPPER RIDGE WILL BEGIN TO
BUILD IN FROM NORTHEAST. THERE WILL STILL BE LINGERING MOISTURE
PRIMARILY IN THE SOUTHERN PORTION OF THE AREA THEREFORE HAVE GONE
WITH CHANCE TO SLIGHT POPS FOR SHOWERS AND THUNDERSTORMS WITH HIGHER
CHANCE ACROSS CENTRAL GA BY AFTERNOON INTO EVENING. CHANCES LOOK TO
DIMINISH AFTER MIDNIGHT.
FOR TEMPS...GENERAL BLEND OF GUIDANCE LOOKS REASONABLE WITH NEAR
NORMAL LOWS AND APPRX 3-5 DEGREE BELOW NORMAL HIGHS.
BAKER
HYDROLOGY...
AMPLE MOISTURE AND ASSOCIATED NUMEROUS SHOWERS WITH EMBEDDED
THUNDERSTORMS WILL ALLOW FOR ADDITIONAL PRECIPITATION AREA-WIDE
THROUGH THIS AFTERNOON AND INTO THE EVENING BEFORE ACTIVITY
DIMINISHES FROM THE EAST BY LATE EVENING. WHILE A WIDESPREAD
0.5-0.75 INCHES IS LIKELY...ANY TRAINING OF STORMS CAN CAUSE LOCAL
AMOUNTS OF 1-2 INCHES TO FALL QUICKLY AND BECOME INSTANT RUNOFF.
HAVE THEREFORE CONTINUED CURRENT FLASH FLOOD WATCH AND EXPANDED
ACROSS ALL OF NORTH GEORGIA UNTIL 10 PM THIS EVENING.
BAKER
LONG TERM /TUESDAY THROUGH SUNDAY/...
NO SIG CHANGES WERE MADE TO THE EXTENDED. AT THIS TIME THE CURRENT
FORECAST APPEARS TO BE ON TRACK. ONLY TWEAKED SOME HIGHS AND LOWS
SLIGHTLY IN THE EXTENDED AND LOADED IN THE LATEST WIND AND
DEWPOINT DATA INTO THE EXTENDED. HAVE ATTACHED PREVIOUS DISCUSSION FOR
BREVITY.
ARG
PREV DISCUSSION... /ISSUED 211 PM EDT SUN JUL 14 2013/
LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE ALOFT WILL BE OVER THE OH-MID MS VALLEY TO START THE
LONG TERM. A MOIST AIRMASS WILL STILL BE IN PLACE AS A DEEP EASTERLY
FLOW PATTERN PERSISTS. THIS SHOULD ALLOW A MORE DIURNAL TENDENCY TO
ANY CONVECTION MONDAY NIGHT AND TUESDAY.
THIS PATTERN LOOKS TO CONTINUE ON WEDNESDAY EXCEPT GUIDANCE HINTING
AT AN EASTERLY WAVE TO MOVE ACROSS THE AREA TENDING TO AFFECT N GA
MORE THAN CENTRAL. SIMILAR PATTERN CONTINUES FOR THURSDAY AND FRIDAY
WITH THE UPPER RIDGE WEAKENING ON FRIDAY AND THE UPPER FLOW BECOMING
MORE WSW FOR SATURDAY INTO SUNDAY. AT LEAST SCATTERED AFTERNOON AND
EVENING SHOWERS AND THUNDERSTORMS CAN BE EXPECTED THROUGH SUNDAY FOR
MUCH OF THE AREA. ALL IN ALL TEMPERATURES SHOULD GENERALLY BE CLOSE
TO NORMAL.
BDL
&&
.AVIATION...
00Z UPDATE...
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS CONTINUE ACROSS THE
REGION THIS EVENING. LATEST RUNS OF THE HRRR SHOW MOST CONVECTION
DIMINISHING BY 02Z. GOOD EASTERLY FLOW TONIGHT SHOULD HELP WITH A
LOWER DECK OF IFR STRATUS DEVELOP AROUND/AFTER 06Z. PATCHY MVFR
FOG WILL ALSO BE AN ISSUE. DIURNAL CU IS EXPECTED TOMORROW AFTERNOON.
THE CHANCES FOR PRECIP ARE TOO LOW TO MENTION AT THIS TIME.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE CIGS/VBYS. HIGH CONFIDENCE REMAINING ELEMENTS.
NLISTEMAA
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 85 70 91 / 40 30 20 20
ATLANTA 69 84 71 88 / 40 30 30 20
BLAIRSVILLE 66 84 65 86 / 40 20 20 20
CARTERSVILLE 70 85 70 90 / 40 30 20 20
COLUMBUS 72 86 72 90 / 40 40 30 30
GAINESVILLE 69 83 71 89 / 40 30 20 20
MACON 71 86 70 90 / 40 40 30 30
ROME 70 87 70 90 / 40 30 30 20
PEACHTREE CITY 70 84 68 88 / 40 40 30 20
VIDALIA 72 86 72 90 / 40 40 20 40
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL 10 PM EDT THIS EVENING FOR THE FOLLOWING
ZONES: BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...
BUTTS...CARROLL...CATOOSA...CHATTOOGA...CHEROKEE...CLARKE...
CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DADE...DAWSON...
DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FANNIN...FAYETTE...
FLOYD...FORSYTH...GILMER...GLASCOCK...GORDON...GREENE...
GWINNETT...HALL...HANCOCK...HARALSON...HENRY...HOUSTON...
JACKSON...JASPER...JEFFERSON...JOHNSON...JONES...LAMAR...
LAURENS...LUMPKIN...MACON...MADISON...MONROE...MONTGOMERY...
MORGAN...MURRAY...NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...
PAULDING...PEACH...PICKENS...PIKE...POLK...PULASKI...PUTNAM...
ROCKDALE...SCHLEY...SOUTH FULTON...SPALDING...SUMTER...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...WASHINGTON...
WHEELER...WHITE...WHITFIELD...WILCOX...WILKES...WILKINSON.
&&
$$
SHORT TERM...ATWELL
LONG TERM....ATWELL
AVIATION...NLISTEMAA
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...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 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 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.
&&
$$
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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.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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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:
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WWW.TWITTER.COM/NWSCHICAGO
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AREA FORECAST DISCUSSION
NWS GOODLAND KS
523 PM MDT SUN JUL 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 125 PM MDT SUN JUL 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 579DM CLOSED LOW CENTERED
OVER NORTHEAST OKLAHOMA WITH STRONG PV HEIGHT ANOMALY IN PLACE OVER
SOUTHEAST KS. A 599DM RIDGE IS IN PLACE OVER THE NORTHEAST US WITH
AXIS EXTENDING NORTH OF CLOSED LOW INTO THE UPPER MISSISSIPPI VALLEY.
WITH GOOD MOISTURE/INSTABILITY IN PLACE AND SEVERAL WEAK CONVERGENT
AREAS WE ARE ALREADY SEEING THUNDERSTORMS DEVELOPING ALONG SEVERAL
WEAK CONVERGENT AREAS IN OUR CWA. AS LARGE SCALE FORCING INCREASES
AND THE MAIN MOISTURE PLUME MOVES OVER OUR CWA I EXPECT THUNDERSTORM
COVERAGE TO INCREASE. WHAT COULD BE DESCRIBED AS A COLD FRONT WILL
MOVE INTO THE CWA FROM THE SOUTHEAST THIS AFTERNOON AHEAD OF COLD
POOL ASSOCIATED WITH STRONG UPPER LOW. THUNDERSTORMS WILL INCREASE
IN COVERAGE AS THIS BOUNDARY MOVES NORTHWEST WITH BEST FORCING
CURRENTLY ADVERTISED IN THE 21-00Z TIME FRAME ALONG THE KS/CO BORDER
WHERE MOST GUIDANCE IS SHOWING VERY HIGH QPF VALUES. LATEST GFS IS A
LITTLE FURTHER EAST...HOWEVER SHORT RANGE GUIDANCE (RUC/HRRR)
CONTINUE TO SUPPORT THE NAM SOLUTION FURTHER WEST ALONG COLORADO
STATE LINE.
A VERY MOIST AIR MASS IS IN PLACE OVER THE CWA WITH LATEST RAP
ANALYSIS INDICATING PWAT VALUES IN EXCESS OF 1.5 INCHES AND AS HIGH
AS 1.8 INCHES IN NORTHEAST PARTS OF THE CWA. WHILE NOT UNHEARD OF
THIS IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. SB/ML CAPE VALUES
HAVE INCREASED TO NEAR 2000 J/KG ACROSS THE NORTHEAST CWA AND THE
MAIN INSTABILITY AXIS SHOULD CONTINUE TO SPREAD SOUTH AND WEST THIS
AFTERNOON. SHEAR PROFILES ARE VERY WEAK...SO ANY SEVERE THREAT SHOULD
BE TIED TO WIND/HAIL ASSOCIATED WITH PULSE TYPE THUNDERSTORMS. STORM
MOTION WILL GENERALLY BE IN THE 5-15KT RANGE ACROSS THE AREA AND
THERE WILL BE THE POTENTIAL FOR BACK BUILDING AND SLOW PROPAGATION
ALONG THE BOUNDARY OVER OUR WESTERN CWA. WITH HIGH PRECIP RATES AND
SLOW MOVING (POSSIBLY TRAINING) THUNDERSTORM WE COULD SEE AN
ELEVATED THREAT FOR FLASH FLOODING. DESPITE OVERALL SHOWER AND
THUNDERSTORM COVERAGE LIKELY HIGH I AM NOT CONFIDENT THE FLASH FLOOD
THREAT WILL BE WIDESPREAD ENOUGH TO ISSUE A WATCH AT THIS TIME.
ACTIVITY SHOULD COME TO AN END QUICKLY FROM THE EAST TO THE WEST
THIS EVENING AS STRONG SUBSIDENCE BUILDS IN FROM THE NORTHEAST
ASSOCIATED WITH RIDGE BUILDING EAST BEHIND TROUGH. WITH LINGERING
CONVERGENCE ACROSS EASTERN COLORADO AND MOIST UPSLOPE WE COULD SEE A
FEW LINGERING SHOWERS/THUNDERSTORMS THROUGH 12Z WITH PATCHY FOG
POSSIBLY DEVELOPING IN THE 09Z-12Z TIME FRAME.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 158 PM MDT SUN JUL 14 2013
MONDAY MORNING MAY START OUT WITH SOME FOG OVER THE SOUTHERN AND
WESTERN PARTS OF THE AREA. ANY FOG THAT DEVELOPS SHOULD CLEAR OUT
BY MID MORNING. THE UPPER LEVEL LOW PRESSURE THAT BROUGHT RAINFALL
TO THE TRI-STATE AREA WILL CONTINUE TO MOVE SOUTH. LATE MONDAY
AFTERNOON INTO EARLY MONDAY EVENING THERE WILL BE A BAND OF MID
LEVEL LIFT THAT WILL MOVE ACROSS THE FAR SOUTHERN PART OF THE AREA.
THERE WILL BE AMBLE MOISTURE TO WORK...BUT THE LIMITING FACTOR WILL
BE THE STRENGTHEN OF THE LIFT AND THE SMALL AMOUNT OF INSTABILITY
AVAILABLE. AT THIS TIME THERE APPEARS TO BE ENOUGH LIFT AND
INSTABILITY THAT AN ISOLATED STORM CANNOT BE RULED OUT...SO WILL
KEEP THE SLIGHT CHANCES IN THE FORECAST BUT CONFINE THEM TO THE LATE
AFTERNOON AND EARLY EVENING.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA.
SOUNDINGS OVER EAST CENTRAL COLORADO SHOW SOME INSTABILITY TO WORK
WITH AND LITTLE CIHN DURING THE AFTERNOON...BUT WITH NO SURFACE
CONVERGENCE OR UPPER LEVEL LIFT TO TRIGGER STORMS WILL KEEP THE DAY
DRY.
WEDNESDAY THROUGH SUNDAY AN UPPER LEVEL RIDGE WILL MOVE OVER THE
PLAINS THEN BECOME ESTABLISHED OVER THE ROCKIES. TOWARD THE END OF
THE WEEK THE UPPER LEVEL FLOW WILL STRENGTHEN AND BECOME NORTHWEST.
MODELS HAVE FLATTENED OUT THE SHORT WAVE TROUGH THAT WOULD MOVE OVER
THE AREA DURING THE WEEKEND. THE STRENGTH OF THE COLD FRONT HAS
ALSO DECREASED...WITH MODELS WASHING IT OUT ON SATURDAY OVER THE
AREA. HOWEVER MODELS STILL HAVE A SURFACE TROUGH/WEAK COLD FRONT
OVER THE AREA FOR THE WEEKEND. WITH NORTHWEST UPPER LEVEL FLOW OVER
THE AREA THERE IS STILL A POSSIBILITY FOR STORMS TO
DEVELOP...ALTHOUGH NOT AS GOOD AS PREVIOUSLY THOUGHT.
HIGH TEMPERATURES FOR THE PERIOD WILL GRADUALLY WARM TO ABOVE NORMAL
BY THE END OF THE WEEK AS THE UPPER LEVEL RIDGE BUILDS OVER THE
AREA. WITH LITTLE CHANGE IN THE AIR MASS BY THE END OF THE
WEEK...HIGHS WILL LARGELY REMAIN UNCHANGED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 520 PM MDT SUN JUL 14 2013
SHOWERS AND THUNDERSTORMS WILL DIMINISH IN COVERAGE THIS EVENING.
KGLD MAY SEE A BRIEF SHOWER OR THUNDERSTORM THROUGH ABOUT
03Z...WHILE ACTIVITY APPEARS TO BE WEST OF KMCK. OVERNIGHT...LOW
LEVELS ARE VERY MOIST WITH DEW POINTS IN THE 60S AND LIGHT UPSLOPE
WINDS. STRATUS/FOG MAY LOWER FLIGHT CATEGORIES AT EITHER TERMINAL
AROUND SUNRISE BEFORE LIFTING MONDAY MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...024
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 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
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 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...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 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 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 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
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...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
859 PM MDT SUN JUL 14 2013
.UPDATE...
THE EVENING HAS BEEN PRETTY QUIET. ISOLATED SHOWERS AND
THUNDERSTORMS HAVE DEVELOPED OVER THE HIGHER TERRAIN...BUT WERE
HAVING A HARD TIME PUSHING OUT ONTO THE PLAINS. SOUNDINGS SHOWING
A STRONG CAP PRESENT OVER THE PLAINS AND RECENT ACTIVITY HAS NOT
BEEN ENOUGH TO ERODE IT AWAY ENOUGH TO SUSTAIN DEVELOPMENT. HRR
HAS BEEN WAY OVER DONE IN MOST RUNS WITH ACTIVITY SPREADING ACROSS
CENTRAL ZONES. A WEAK SHORTWAVE WAS EVIDENT IN WATER VAPOR OVER
NORTHEAST IDAHO...PROGRESSING SLOWLY NORTHEAST TOWARD THE
SOUTHWEST MOUNTAINS. THIS SHOULD KEEP ISOLATED ACTIVITY GOING OVER
THE HIGHER TERRAIN. DROPPED POPS FOR ALL BUT THE WEST AND
FOOTHILLS THIS EVENING.
BUFKIT SOUNDINGS SUPPORT WARM AIR ADVECTION OVERNIGHT WITH THE
CAP ERODING AWAY AT THE MID LEVELS. THE WEAK SHORTWAVE MENTIONED
ABOVE KICK ACROSS SOUTHERN ZONES OVERNIGHT. THESE TWO FORCES
SHOULD BE ENOUGH TO GENERATE ISOLATED SHOWERS. INSTABILITY DOES
NOT LOOK THAT STRONG...SO WILL KEEP THE PRECIPITATION AS JUST
SHOWERS BUT FELT ENOUGH THERE TO WARRANT A MENTION OF ISOLATED
ACTIVITY OVERNIGHT. TWH
&&
.SHORT TERM...VALID FOR MON AND TUE...
ACTIVE WEATHER WILL CONTINUE TONIGHT THROUGH TUE NIGHT. A BAND OF
CONVECTION CONTINUED MOVING THROUGH SE MT THIS AFTERNOON PER RADAR
IMAGERY. THE BAND WAS BEING FUELED BY JET DIVERGENCE. OTHER
CONVECTION WAS MOVING INTO THE SW PART OF THE AREA AHEAD OF A
SHORTWAVE MOVING INTO W MT AND WEAK WAVES SW OF THE AREA. A WARM
FRONT WILL MOVE N THROUGH THE REGION TONIGHT ACCOMPANIED BY
ISENTROPIC LIFT. THE HRRR HAS BEEN GENERATING CONVECTION OVER THE
S CENTRAL PART OF THE AREA FOR THE LAST FEW RUNS DURING THE
EVENING. THE RAP SHOWED 1000 J/KG OF SURFACE CAPE IN THIS AREA AND
THE WRF HAD DECENT BULK SHEAR...SO STORMS IN THIS AREA COULD BE
STRONG. A LOW-LEVEL JET WILL HELP SUSTAIN CONVECTION IN THE E
THROUGH THE NIGHT. THUS WENT WITH CHANCE POPS S TAPERING TO SLIGHT
CHANCE N DURING THE EVENING...AND SLIGHT CHANCE E OVERNIGHT.
PRECIPITABLE WATERS AROUND AN INCH WILL SUPPORT HEAVY RAIN WITH
THE THUNDERSTORMS.
MON WILL BE A PREFRONTAL DAY. SHORTWAVES WILL CONTINUE MOVING
THROUGH THE SW FLOW ALOFT. INVERTED-V SOUNDINGS WERE FORECAST FOR
THE CENTRAL AND W ZONES. KMLS WAS CAPPED ON BUFKIT. CAPES AT KBHK
WERE 1000-1500 J/KG...BUT SOUNDINGS DID NOT SHOW MUCH IN THE WAY
OF LIFT. HAD CHANCE POPS SE IN THE MORNING NEAR SHORTWAVE ENERGY
THEN ISOLATED TO SCATTERED POPS IN THE AFTERNOON AND EVENING DUE
TO ADDITIONAL SHORTWAVES AND THE APPROACH OF THE FRONT. GOOD
MIXING WILL PROMOTE HIGH TEMPERATURES IN THE 90S IN MANY AREAS.
KEPT POPS THROUGH THE NIGHT DUE TO THE COLD FRONT.
THE FRONT WILL SETTLE OVER THE REGION ON TUE AND THE FLOW WILL
TURN E. HAD MAINLY ISOLATED POPS THROUGH THE DAY. STRONG THETA-E
RIDGE WILL HELP CONTINUE CHANCES FOR THUNDERSTORMS TUE NIGHT. TUE
WILL BE COOLER WITH READINGS IN THE 80S BUT A THERMAL RIDGE WILL
KEEP THE E WARMER WITH TEMPERATURES AROUND 90. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
THE THEME IN THE EXTENDED FORECAST REMAINS SUMMER TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS EACH DAY. BROAD SUMMER RIDGING
WILL FINALLY BE ESTABLISHED ACROSS MOST OF THE CONUS WITH THE
FORECAST AREA REMAINING ON THE NORTHERN EXTENT OF THE RIDGE WITH
THE JET STREAM NEARBY TO THE NORTH.
THIS SETUP WILL ALLOW INCREASING MID-LEVEL MOISTURE ACROSS THE
FORECAST AREA FROM THE MONSOONAL FLOW OUT OF THE SOUTH.
FURTHERMORE...LOW-LEVEL MOISTURE WILL BE ON THE INCREASE THANKS TO
GULF MOISTURE BEING TRANSPORTED UP THE GREAT PLAINS AND INTO THE
FORECAST AREA FROM THE EAST AND NORTHEAST. THIS WILL KEEP PW
VALUES RUNNING BETWEEN 1 AND 1.5 INCHES ACROSS THE FORECAST AREA
WEDNESDAY THROUGH FRIDAY. THESE WILL BE THE BEST DAYS IN THE
EXTENDED FORECAST FOR THUNDERSTORM ACTIVITY. DEEP LAYER SHEER
(0-6KM) SHOULD BE WEAK ON WEDNESDAY AS THE JET STREAM REMAINS
MOSTLY NORTH OF THE FORECAST AREA...THUS EXPECT STORMS TO BE HEAVY
RAINERS BUT THE SEVERE POTENTIAL SHOULD BE VERY LIMITED. DEEP
LAYER SHEER SHOULD INCREASE TO AROUND 40 KTS FOR THURSDAY AND
FRIDAY AS THE JET SAGS FARTHER SOUTH. THIS WILL BE COUPLED WITH
COOLER 700 MB TEMPERATURES. THUS EXPECT THUNDERSTORMS ON THURSDAY
AND FRIDAY COULD BE ON THE STRONG SIDE WITH SOME ISOLATED SEVERE
POTENTIAL.
STRONGER ZONAL TO NORTHWESTERLY FLOW ESTABLISHES OVER THE FORECAST
AREA BY THE WEEKEND. THIS HELPS TO KEEP MONSOONAL MOISTURE LOCKED
TO THE SOUTH OF THE FORECAST AREA WHILE THE LOW-LEVEL MOISTURE
BECOMES SHIFTED TO THE EAST. THIS SHOULD MINIMIZED OUR CHANCES OF
PRECIPITATION THIS WEEKEND.
TEMPERATURES WILL REMAIN JUST ABOVE SEASONAL NORMALS IN THE UPPER
80S AND LOW 90S THROUGH THE EXTENDED FORECAST.
CHURCH
&&
.AVIATION...
A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO ARE POSSIBLE
OVER FAR WESTERN ROUTES FOR THE NEXT FEW HOURS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH MID DAY MONDAY. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 061/095 064/083 062/090 066/092 065/093 065/094 065/094
22/T 22/T 32/T 32/T 33/T 31/B 11/B
LVM 052/091 054/085 056/091 055/092 056/093 052/095 052/095
23/T 33/T 33/T 33/T 33/T 32/T 21/B
HDN 061/096 062/087 058/092 061/093 063/093 061/095 061/096
22/T 22/T 32/T 32/T 32/T 21/B 11/B
MLS 065/095 067/089 064/093 068/093 066/093 067/094 066/094
12/T 22/T 22/T 22/T 22/T 21/B 11/U
4BQ 062/093 062/092 061/093 063/091 065/090 061/092 060/093
23/T 22/T 21/U 12/T 22/T 21/B 11/U
BHK 060/087 062/088 059/091 064/090 064/088 062/089 061/090
13/T 22/T 21/B 22/T 22/T 22/T 21/U
SHR 058/091 058/089 058/092 058/091 058/090 057/092 057/094
22/T 22/T 22/T 22/T 33/T 31/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
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...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 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 WILMINGTON NC
1148 PM EDT SUN JUL 14 2013
.SYNOPSIS...
A LARGE MID LEVEL RIDGE OVER THE OHIO VALLEY WILL GROW IN SIZE
AND DRIFT SOUTH THROUGH THE MIDDLE OF THE WEEK. THE RIDGE WILL
WEAKEN LATE IN THE WEEK WHILE BERMUDA HIGH BUILDS BACK FROM THE
EAST AND PIEDMONT TROUGH STRENGTHENS. NEXT WEEKEND A COLD FRONT
WILL APPROACH FROM THE NORTHWEST...POTENTIALLY BRINGING AN
INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1100 PM SUNDAY...HAVE ADJUSTED POPS TO A LOW CHANCE FOR
MAINLY THE PRE-DAWN HRS OF MONDAY TO ACCOUNT FOR ANY ONSHORE
MOVEMENT OF NOCTURNAL SHRA ACTIVITY FROM OFF THE ADJ ATLANTIC.
LATEST ADJACENT NWS 88D RADARS DEPICT THE INCREASING WIDELY
SCATTERED SHRA DEVELOPMENT OVER THE ADJACENT ATLANTIC WATERS.
NAMBUFR SOUNDINGS ACROSS THE COASTAL FA...INDICATE AN EASTERLY
FLOW THRUOUT THE ATM COLUMN. AS A RESULT...THIS DEEP ONSHORE FLOW
WILL PERIODICALLY PUSH ANY ATLANTIC PCPN ACTIVITY ONSHORE. A
MODEST CAP WILL EXIST IN THE 800-750 MB RANGE VIA PROGGED NAMBUFR
HOURLY SOUNDINGS...THUS PUTTING A LID ON ANY FURTHER VERTICAL
DEVELOPMENT OF THE OVERNIGHTS PCPN. THEREFORE...DO NOT EXPECT
MUCH IF ANY THUNDERSTORM ACTIVITY TO ACCOMPANY THIS PCPN. THE
LATEST MIN TEMP FORECAST OF 70 TO 75 DEGREES STILL LOOKING
AOK...WITH 74 TO 78 DEGREE READINGS RESERVED FOR ALONG THE
IMMEDIATE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SURFACE AND MID LEVEL RIDGING OVER THE OH VALLEY
WILL GRADUALLY EXPAND SOUTH DURING THE PERIOD. EAST FLOW AROUND THE
SOUTHERN EDGE OF THE SURFACE HIGH WILL HELP KEEP TEMPERATURES A
LITTLE COOLER THAN WHAT IS TYPICAL FOR MID JULY...ESPECIALLY NEAR
THE COAST. EASTERLY FLOW WILL ALSO MAINTAIN THE SUPPLY OF LOW LEVEL
MOISTURE. CONVERGENCE ALONG THE EASTERLY WIND ENHANCED SEA BREEZE
MAY TRIGGER SOME WEAK CONVECTION ACROSS INLAND AREAS MON AFTERNOON.
ALTHOUGH THERE WILL BE SOME MID LEVEL SUBSIDENCE ON THE PERIPHERY OF
THE 5H RIDGE MON IT WILL BE ON THE WEAK SIDE AND PROBABLY NOT STRONG
ENOUGH TO SUPPRESS ALL DEEPER CONVECTION. SOUTHWARD EXPANSION OF 5H
RIDGE ON TUE INCREASES SUBSIDENCE WHICH SHOULD KEEP THE REGION DRY.
HAVE TWEAKED POP FORECAST FOR MON WITH VALUES RANGING FROM SLIGHT
CHANCE TO LOW CHANCE ACROSS INLAND SC...WHERE SUBSIDENCE SHOULD BE
WEAKEST. MAINTAIN THE DRY FORECAST BUT HAVE NON ZERO POP TUE/TUE
NIGHT.
EASTERLY FLOW ON MON WILL KEEP TEMPERATURES ACROSS MUCH OF THE
REGION BELOW CLIMO AND MOST AREAS WILL STRUGGLE TO REACH 90. SUBTLE
WIND SHIFT...TO SOUTHEAST...ON TUE WILL KEEP COASTAL LOCATIONS COOL
BUT ALLOW INLAND AREAS TO WARM UP. LOW 90S ARE EXPECTED WITH
POTENTIAL FOR ISOLATED MID 90S. LOWS WILL RUN NEAR TO SLIGHTLY ABOVE
CLIMO. TUE NIGHT WILL BE WARMER OF THE TWO NIGHTS AS BERMUDA HIGH
STARTS TO REASSERT ITSELF AND SOUTHERLY FLOW DEVELOPS. ADDITIONALLY
GUIDANCE IS SHOWING A WEAK SHORTWAVE DROPPING SOUTH ALONG THE EAST
COAST TUE NIGHT. NOT SOLD ON STRENGTH...TIMING...AND LOCATION OF
THIS FEATURE BUT IT COULD PRODUCE A MID LEVEL CLOUD DECK TUE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...STRONG RIDGE OVER THE OHIO VALLEY SINKS SOUTH
AND WEAKENS BY THE WEEKEND AS A MID TO UPPER TROUGH DIGS DOWN FROM
CANADA AND RIDES THROUGH THE NORTHEAST INTO THE MID ATLANTIC STATES
THROUGH THE WEEKEND. THE RIDGE ALOFT WILL BE ELONGATED NORTH OF OUR
LOCAL AREA AS IT REACHES UP THROUGH THE LOW AND MID TO UPPER LEVELS
OF THE ATMOSPHERE. THEREFORE THERE WILL BE A DEEP EAST TO NORTHEAST
FLOW INITIALLY THROUGH WED. OVERALL EXPECT A FAIRLY DRY ATMOSPHERE
WITH MID TO UPPER RIDGE REACHING DOWN INTO AREA LEADING TO LITTLE TO
NO UPPER LEVEL DYNAMICS TO SUPPORT MUCH IN THE WAY OF SHWRS/TSTM
ACTIVITY BUT MODELS DO SHOW A MINOR PERTURBATION MAKING ITS WAY
AROUND THE BASE OF THE H5 RIDGE INTO THE CAROLINAS ON WED. THESE
FEATURES ARE TOUGH TO TIME BUT IT MAY LEAD TO A SLIGHT ENHANCEMENT
OF CLOUDS AND/OR CONVECTIVE DEVELOPMENT ON WED...MAINLY
INLAND...ESPECIALLY AS PIEDMONT TROUGH BECOMES MORE PRONOUNCED
THROUGH MID TO LATE WEEK. GFS SHOWING PCP WATER VALUES REACHING UP
OVER 2 INCHES INLAND WED AFTN.
BY THURSDAY THE LOW LEVEL FLOW BECOMES MORE SOUTHWESTERLY AS BERMUDA
RIDGE AND PIEDMONT TROUGH BECOME DOMINANT FEATURES. A FAIR AMOUNT OF
SUBSIDENCE AND DRY AIR WILL CONTINUE THROUGH THURS AND FRI AS MID TO
UPPER RIDGE MOVES CLOSER OVERHEAD. AT THE LOW LEVELS MODELS SHOW
DRIER AIR UPSTREAM BRINGING PCP WATER VALUES DOWN NEAR 1.5 INCHES
THURS INTO FRI. BY FRI NIGHT INTO SATURDAY THE SOUTHWEST FLOW
CONTINUES WITH A SLIGHT INCREASE IN MOISTURE BUT OVERALL A MODEST
AMOUNT FOR THIS TIME OF YEAR.
BASICALLY EXPECT MORE ISOLATED AND LOCALIZED SHOWER ACTIVITY THROUGH
MOST OF THE PERIOD...WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT
BOUNDARY AND FURTHER INLAND ALONG PIEDMONT TROUGH. BY SUNDAY THE MID
TO UPPER TROUGH MAY PUSH A COLD FRONT INTO THE CAROLINAS WITH PLENTY
OF MOISTURE AND GREATER INSTABILITY AHEAD OF THE FRONT ACROSS THE
CAROLINAS.
TEMPERATURES CLOSE TO OR A FEW DEGREES ABOVE CLIMO THROUGH AT LEAST
THE FIRST HALF OF THE PERIOD AS RIDGE KEEPS HIGHER H5 HEIGHTS AND
LOW LEVEL THICKNESSES ACROSS THE AREA. EXPECT READINGS 90 TO 95 MOST
PLACES DURING THE DAY AND LOWER 70S AT NIGHT.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...NO SIGNIFICANT CHANGE TO THE CURRENT TAFS. ALTHOUGH MVFR
CIGS COULD OCCUR AT TIMES THIS EVENING FEEL VFR WILL BE THE
PREDOMINATE CATEGORY. ISOLATED SHOWERS WILL CONTINUE THIS EVENING
AND OVERNIGHT BUT THE CHANCE OF ANY TERMINAL BEING AFFECTED IS LOW.
ESE WINDS WILL DECREASE AND BECOME MORE NE BY MIDNIGHT.
THERE IS MODERATE CONFIDENCE FOR IFR CIGS AFTER 06-08Z AT KFLO/KLBT
WITH MVFR CIGS AT THE COASTAL TERMINALS. CIGS COULD DROP INTO THE
LIFR LEVEL 10-13Z. FOG POTENTIAL WILL BE HINDERED BY BOUNDARY LAYER
WINDS AROUND 16 KTS...BUT ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW
VSBYS TO POTENTIALLY DROP TO AT LEAST MVFR LEVELS AT KFLO/KLBT.
VSBYS SHOULD REMAIN VFR AT THE COASTAL TERMINALS. AFTER SUNRISE VFR
EXPECTED AT THE COASTAL TERMINALS. AT KFLO/KLBT ANY SUB-VFR VSBYS
INCREASE TO VFR FAIRLY RAPIDLY BUT CIGS SLOWLY RISE TO MVFR BY
14Z...THEN TO VFR 16Z. WINDS WILL BECOME E 10-15 KNOTS...HIGHEST
AT THE SOUTHERN COASTAL TERMINALS. ANY SHOWER DEVELOPMENT SHOULD BE
ISOLATED JUST INLAND OF THE COASTAL TERMINALS DURING THE MORNING.
THIS ACTIVITY WILL DEVELOP MORE TOWARDS THE KFLO TERMINAL BY MID TO
LATE MORNING.
EXTENDED OUTLOOK...A CHANCE OF EARLY MORNING IFR CIGS AND TEMPO MVFR
MORNING/AFTERNOON CIGS THROUGH THE PERIOD. ISOLATED SHOWERS AND
THUNDERSTORMS MONDAY...AND WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SUNDAY...SCEC FOR ALL WATERS EXCEPT AMZ254...VALID
THROUGH MONDAY MID-MORNING. SFC PRESSURE PATTERN AND TIGHTENED
GRADIENT WILL YIELD ENE TO ESE WIND DIRECTIONS AT 10 TO 20
KT...WITH A FEW GUSTS UP TO 25 KT. THIS WELL SUPPORTED BY THE
LATEST HRRR HOURLY PROGGED SFC WIND DATA AND THE CURRENT NAM AND
GFS SFC FIELDS. THE LATTER 2 MODELS INDICATE A WESTWARD MOVING
INVERTED SFC TROF TO PROGRESS ACROSS THE ATL WATERS FROM WELL OFF
THE SE U.S. COAST...TO THE ATL WATERS JUST OFFSHORE FROM THE GA-FL
COAST BY DAYBREAK MONDAY. WAVEWATCH3 INDICATES A SWATH OR BUBBLE
OF HIER SEAS...AN EASTERLY SWELL EXHIBITING 8 SECOND
PERIODS...ASSOCIATED WITH THIS TROF THAT PARTIALLY PUSHES ACROSS
THE ILM AREA WATERS. AS A RESULT...SIGNIFICANT SEAS WILL REMAIN OR
HOLD IN THE 3 TO 5 FOOT RANGE OVERNIGHT...AND TRANSITION FROM THE
INITIAL DOMINANT WIND DRIVEN WAVE EXHIBITING AVERAGE PERIODS IN
THE 5.0 TO 6.0 SECOND RANGE...TO AN INCREASING AND MORE DOMINANT E
TO ESE SWELL AT 7 TO 8 SECOND PERIODS. WIDELY SCATTERED NOCTURNAL
SHRA TO PUSH ACROSS THE AREA WATERS...WITH THE BEST COVERAGE TO
OCCUR FROM CAPE FEAR SOUTHWARD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/... AS OF 3 PM
SUNDAY...GRADIENT OVER THE WATERS WILL WEAKEN DURING THE PERIOD AS
SURFACE HIGH NORTHWEST OF THE WATERS SETTLES SOUTH. FLOW WILL
REMAIN EAST TO NORTHEAST INTO TUE BEFORE BERMUDA HIGH STARTS TO
EXTEND WEST...SETTING UP RETURN FLOW. NORTHEAST FLOW STARTS OUT ON
THE HIGH END OF THE 10 TO 15 KT RANGE MON MORNING BUT SHOULD BE 10
KT OR LESS BY MID AFTERNOON. RELAXED GRADIENT KEEPS SOUTHERLY FLOW
10 KT OR LESS THROUGH TUE NIGHT. SEAS WILL SLOWLY SUBSIDE ON
MON...FALLING FROM 3 TO 5 FT AT THE START OF THE PERIOD TO 2 TO 4
FT MON NIGHT. SEAS CONTINUE TO DECREASE TUE AND TUE NIGHT IN THE
PRESENCE OF LIGHT WINDS...FALLING TO 2 FT BY THE END OF THE
PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WHILE RIDGE SHIFTS FURTHER SOUTH ALOFT
CREATING A MORE EASTERLY FLOW ABOVE THE SURFACE...THE FLOW AT THE
SURFACE WILL BACK FROM WESTERLY ON WED AS HIGH PRESSURE CENTERED
SOUTH OF AREA WEAKENS TO MORE SOUTHWEST TO SOUTHERLY AS BERMUDA
HIGH TAKES CONTROL THURS INTO NEXT WEEKEND. OVERALL FAIRLY TYPICAL
SUMMERTIME PATTERN SETS UP THURS INTO THE WEEKEND WITH HIGH
PRESSURE TO THE EAST AND PIEDMONT TROUGH OVER THE INLAND CAROLINAS
TO PRODUCE PERSISTENT S-SW FLOW. INITIALLY A LIGHTER OFF SHORE
FLOW WILL ALLOW SEAS TO SUBSIDE TO LESS THAN 3 FT MOST WATERS. THE
PERSISTENT AND INCREASING S-SW FLOW UP TO 15 KTS OR SO THAT SETS
UP THURS INTO THE WEEKEND WILL PUSH SEAS UP 3 TO 4 FT BY LATE FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR
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
NWS GRAND FORKS ND
1002 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 1000 PM CDT SUN JUL 14 2013
SHOWER ACTIVITY IN FAR SOUTHEASTERN FCST AREA CONTINUES TO WEAKEN
IN COVERAGE AND MOSTLY AREAS OF LIGHT RAIN/DRIZZLE. KEPT SCT
SHOWERS IN THRU THE NIGHT. COORD WITH WFO BIS AND REMOVED ANY POPS
FOR AREAS NORTH AND WEST OF DEVILS LAKE. SHOWERS WEST AND NORTH OF
MINOT HEADED NORTHEAST AND LATEST 00Z NAM/RUC/HRRR ALL HAVE DRY IN
DVL BASIN TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 635 PM CDT SUN JUL 14 2013
QUESTION THIS TAF PERIOD IS EXTENT OF MVFR CIGS. LATEST HRRR AND
GENERAL CLOUD MOVEMENT VIA SATELLITE WOULD INDICATE THAT AREAS
THAT ARE MVFR WILL STAY THAT WAY THROUGH LATE MORNING MONDAY AS
FRONT SYSTEM IS DRAPED TO OUR SOUTH AND MOISTURE OVERRUNS IT.
BEMIDJI COULD GO DOWN INTO IFR CIGS OVERNIGHT OF IS OFTEN THE CASE
DUE TO THEIR HIGHER ELEVATION. TVF-GFK-DVL ON THE DRY SIDE WITH
SCT-BKN 6000 FT CLOUD WITH SOME MID CLOUD ABOVE IT. AS FRONT DOES
TURN NORTH DURING THE MIDDAY-AFTN MONDAY DID BRING IN LOW END VFR
CIGS INTO DVL-GFK-TVF TOWARD 18Z AS WINDS TURN SOUTHEAST AND DID
ALLOW LOW END MVFR CIGS AT BJI-FAR TO LIFT SOME. DID NOT INCLUDE
RAIN AT ANY TAF SITE THOUGH ISOLD SHOWERS REMAIN AROUND BJI THRU
EARLY EVE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
653 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 635 PM CDT SUN JUL 14 2013
MAIN RAIN BAND THAT PRODUCED NARROW AREA OF 2-3 INCHES OF RAIN
ACROSS SOUTHEASTERN GRANT CO MN AND 1-2 INCHES IN SOUTHEASTERN
OTTER TAIL INTO SOUTHERN WADENA COUNTIES TODAY HAS SHIFTED EAST.
RADAR SHOWS A FEW OTHER SHOWERS DEVELOPING A BIT SOUTH MORE SO IN
THE WILLMAR-ALEX-STC AREA. FRONTAL SYSTEM REMAINS STUCK TONIGHT FROM
NEAR INTERNATIONAL FALLS THROUGH BEMIDJI TO ELBOW LAKE TO NEAR
WATERTOWN. HRRR INDICTES SOME LIGHT SHOWERS THRU THE NIGHT JUST
NORTH OF THIS FRONT....BUT NOT NEARLY AS INTENSE AS WHAT FELL TODAY.
OTHERWISE A FEW SCAT SHOWERS MAY MAKE IT INTO NE ND LATER TONIGHT
FROM THE WEST....BUT THE MAIN SHORTWAVE MOVES INTO SASK. INSTABILITY
QUITE WEAK TONIGHT SO THUNDER RISK IS A LOT LOWER AND THUS WILL GO
MORE SHOWERY THAN THUNDER IN UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 635 PM CDT SUN JUL 14 2013
QUESTION THIS TAF PERIOD IS EXTENT OF MVFR CIGS. LATEST HRRR AND
GENERAL CLOUD MOVEMENT VIA SATELLITE WOULD INDICATE THAT AREAS
THAT ARE MVFR WILL STAY THAT WAY THROUGH LATE MORNING MONDAY AS
FRONT SYSTEM IS DRAPED TO OUR SOUTH AND MOISTURE OVERRUNS IT.
BEMIDJI COULD GO DOWN INTO IFR CIGS OVERNIGHT OF IS OFTEN THE CASE
DUE TO THEIR HIGHER ELEVATION. TVF-GFK-DVL ON THE DRY SIDE WITH
SCT-BKN 6000 FT CLOUD WITH SOME MID CLOUD ABOVE IT. AS FRONT DOES
TURN NORTH DURING THE MIDDAY-AFTN MONDAY DID BRING IN LOW END VFR
CIGS INTO DVL-GFK-TVF TOWARD 18Z AS WINDS TURN SOUTHEAST AND DID
ALLOW LOW END MVFR CIGS AT BJI-FAR TO LIFT SOME. DID NOT INCLUDE
RAIN AT ANY TAF SITE THOUGH ISOLD SHOWERS REMAIN AROUND BJI THRU
EARLY EVE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
646 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 635 PM CDT SUN JUL 14 2013
MAIN RAIN BAND THAT PRODUCED NARROW AREA OF 2-3 INCHES OF RAIN
ACROSS SOUTHEASTERN GRANT CO MN AND 1-2 INCHES IN SOUTHEASTERN
OTTER TAIL INTO SOUTHERN WADENA COUNTIES TODAY HAS SHIFTED EAST.
RADAR SHOWS A FEW OTHER SHOWERS DEVELOPING A BIT SOUTH MORE SO IN
THE WILLMAR-ALEX-STC AREA. FRONTAL SYSTEM REMAINS STUCK TONIGHT
FROM NEAR DULUTH TOWARD LITTLE FALLS THEN TO NEAR WATERTOWN. HRRR
INDICTES SOME LIGHT SHOWERS THRU THE NIGHT JUST NORTH OF THIS
FRONT....BUT NOT NEARLY AS INTENSE AS WHAT FELL TODAY. OTHERWISE A
FEW SCAT SHOWERS MAY MAKE IT INTO NE ND LATER TONIGHT FROM THE
WEST....BUT THE MAIN SHORTWAVE MOVES INTO SASK. INSTABILITY QUITE
WEAK TONIGHT SO THUNDER RISK IS A LOT LOWER AND THUS WILL GO MORE
SHOWERY THAN THUNDER IN UPDATE.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 635 PM CDT SUN JUL 14 2013
QUESTION THIS TAF PERIOD IS EXTENT OF MVFR CIGS. LATEST HRRR AND
GENERAL CLOUD MOVEMENT VIA SATELLITE WOULD INDICATE THAT AREAS
THAT ARE MVFR WILL STAY THAT WAY THROUGH LATE MORNING MONDAY AS
FRONT SYSTEM IS DRAPED TO OUR SOUTH AND MOISTURE OVERRUNS IT.
BEMIDJI COULD GO DOWN INTO IFR CIGS OVERNIGHT OF IS OFTEN THE CASE
DUE TO THEIR HIGHER ELEVATION. TVF-GFK-DVL ON THE DRY SIDE WITH
SCT-BKN 6000 FT CLOUD WITH SOME MID CLOUD ABOVE IT. AS FRONT DOES
TURN NORTH DURING THE MIDDAY-AFTN MONDAY DID BRING IN LOW END VFR
CIGS INTO DVL-GFK-TVF TOWARD 18Z AS WINDS TURN SOUTHEAST AND DID
ALLOW LOW END MVFR CIGS AT BJI-FAR TO LIFT SOME. DID NOT INCLUDE
RAIN AT ANY TAF SITE THOUGH ISOLD SHOWERS REMAIN AROUND BJI THRU
EARLY EVE.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...RIDDLE
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
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 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
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
912 PM CDT SUN JUL 14 2013
.DISCUSSION...LOWERED (BUT DID NOT REMOVE) RAIN OVER THE NORTHEAST
FOR TONIGHT. ALTHOUGH CONVECTION IS ON THE WANE...SURFACE
CONVERGENCE TONIGHT NEAR THE COAST AND LACK OF CIN COULD RESULT IN
OVERNIGHT SHOWERS/THUNDER OVER THE NORTHEAST ERGO THE POPS IN THAT
AREA. INCREASED CLOUD COVER AND ADJUSTED OTHER FIRST PERIOD
PARAMETERS WHERE NEEDED. DID NOT MESS WITH OVERNIGHT LOWS. REST OF
FORECAST FINE FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 631 PM CDT SUN JUL 14 2013/
DISCUSSION...SEE AVIATION DISCUSSION BELOW FOR THE 00Z TAFS.
AVIATION...AS OF 625 PM CDT...RADAR WAS INDICATING SHRA/TSRA`S N
OF THE CWA MOVG S. THERE IS SOME UNCERTAINTY AS TO HOW FAR S THIS
ACTIVITY WILL MOVE DUE TO THE AFFOREMENTIONED REASONS IN THE
PREVIOUS DISCUSSION BELOW. GIVEN THE PROXIMITY OF THE CONVECTION
TO VCT...DECIDED TO INCLUDE A TEMPO WITH TSRA UNTIL 02Z.
OTHERWISE...CIGS/VSBYS ARE EXPECTED TO BE AT VFR LEVELS THROUGH
MUCH OF THE TAF PERIOD. INCREASING MOISTURE THROUGH MON MAY LEAD
TO ISOLD/SCT SHRA`S ALONG THE SEA BREEZE AND ADDITIONAL CONVECTION
POSSIBLY MOVING INTO THE NRN CWA FROM THE HILL COUNTRY. FOR NOW
WENT WITH VCSH FOR THE LATTER PART OF THE VCT TAF WHERE CHCS ARE
BEST.
PREV DISCUSSION... /ISSUED 619 PM CDT SUN JUL 14 2013/
DISCUSSION...LAPS DATA AND HRRR MODEL DATA STILL SUGGESTING THAT
CONVECTION ALONG THE BOUNDARY SHOULD WEAKEN AND DISSIPATE BEFORE
IT GETS MUCH FARTHER EAST. STILL...ACTIVITY STILL GETTING A BIT
TOO CLOSE TO VICTORIA AREA NOT TO INCREASE POPS AT LEAST INTO THE
CHANCE CATEGORY. LAPS NOW SHOWING A BIT OF A CAP STARTING TO FORM
JUST SOUTH OF VICTORIA...WE WILL SEE IF THIS IS ENOUGH. IN ANY
CASE...DECIDED TO UPDATE FORECAST FOR AFOREMENTIONED ACTIVITY.
WILL MONITOR FOR FURTHER UPDATES AS NEEDED. PRODUCTS ARE OUT.
PREV DISCUSSION... /ISSUED 328 PM CDT SUN JUL 14 2013/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN AREA OF SHOWERS
AND THUNDERSTORMS IS CURRENTLY LOCATED OVER EAST CENTRAL TEXAS.
ADDITIONAL CONVECTION HAS DEVELOPED ALONG SOUTHWARD MOVING
BOUNDARY OVER SOUTH CENTRAL TEXAS...AND THIS ACTIVITY MAY MOVE
INTO THE REGION LATER THIS AFTERNOON/EVENING. LATEST LAPS DATA
SHOWS CAPE VALUES BETWEEN 1500 AND 2000 J/KG OVER THE EASTERN
PARTS OF THE CWA. IF CONVECTION CAN CONTINUE TO MOVE SOUTHWARD
INTO THE AREA...THEN A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAINFALL COULD BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING
MAINLY OVER THE NORTHERN AND NORTHEAST ZONES. CURRENT FORECAST HAS
THIS ACCOUNTED FOR THE SLIGHT END POPS OVER THESE LOCATIONS.
MOISTURE AND CLOUD COVER INCREASES FURTHER TONIGHT AND ALONG WITH
CONTINUED SOUTHERLY WINDS SHOULD LEAD TO A WARM NIGHT ACROSS SOUTH
TEXAS. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 70S AND INCREASED
TEMPS OVER MAVMOS VALUES. UPPER LOW WILL CONTINUE TO TRACK
WESTWARD ACROSS OKLAHOMA AND NORTH TEXAS ON MONDAY. WEAKNESS IN
FLOW ALOFT WITH LITTLE TO NO CAPPING SHOULD ONCE AGAIN PROVE
SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT. HIGHEST
CHANCES WILL BE OVER THE VICTORIA CROSSROADS WHERE BETTER MOISTURE
WILL RESIDE. HIGHS ON MONDAY WILL BE SET BACK A FEW DEGREES
(THOUGHT STILL IN THE 90S) DUE TO CLOUD COVER AND RAIN CHANCES...
AND HAVE EITHER GONE WITH OR UNDERCUT GUIDANCE BY A FEW DEGREES.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN FORECAST CHALLENGE FOR
TODAY CONTINUES TO BE POP PLACEMENT/COVERAGE THROUGH THE WORK WEEK.
ALL GUIDANCE SUITES CONTINUE TO ADVERTISE POTENTIALLY WET WEEK FOR
SOUTH TEXAS AS DEEP TROPICAL MOISTURE IS PROG TO EXIST FROM TUESDAY
THROUGH THURS/FRI. THE INTERACTION BETWEEN THE DEEP MOISTURE...
PERIODIC POS VORT ADVECTION...WEAK ELONGATED TUTT SIGNATURE...WEAK
SURFACE TROUGHING...AND ANY MESOSCALE BOUNDARIES /OUTFLOW
BOUNDARIES AND SEABREEZE...SHOULD ALL LEAD TO A SCATTERING OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY THROUGH THURSDAY. TUESDAY/S
PRECIP CHANCES SHOULD BE BASED ON PIECE OF H5 VORTICITY DRIFTING
OUT OF OLD MEX AND INTERACTING WITH UNSTABLE AIRMASS AND DEEP
MOISTURE THAT SHOULD ALREADY BE IN PLACE. WED AND THURSDAY/S
CHANCES ARE BASED ON WEAK INVERTED SURFACE TROUGH AND WEAK TUTT
STRETCHING INTO THE REGION...WHICH ONCE AGAIN SHOULD LEAD TO A
SCATTERING OF SHOWERS AND THUNDERSTORMS. GIVEN DEEP MOISTURE OF
AOA 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS
WEEK...BUT AT THIS TIME WIDESPREAD FLOODING RAINS ARE NOT
EXPECTED. SLIGHT CHANCES OF PRECIP MAY CONTINUE FRIDAY AND INTO
NEXT WEEKEND...BUT WILL BE DEPENDENT ON HOW MUCH DRIER AIR CAN
WORK ITS WAY INTO THE AREA AS H85 HIGH SHIFTS FARTHER EAST FROM
THE MIDWEST TO THE SE COAST. MAX TEMPS THIS WEEK WILL BE STRONGLY
DEPENDENT ON COVERAGE OF PRECIP AND CLOUD COVER...FOR NOW HAVE
GONE A LITTLE ON THE WARM SIDE GIVEN THAT WE SHOULD NOT HAVE
WIDESPREAD CLOUD COVER EVERY DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 94 77 94 77 / 10 30 30 50 30
VICTORIA 76 91 75 93 74 / 20 50 30 50 30
LAREDO 79 98 78 97 78 / 10 20 30 50 30
ALICE 75 96 76 94 75 / 10 20 30 50 30
ROCKPORT 80 88 79 92 77 / 20 30 30 50 40
COTULLA 76 96 76 97 75 / 10 20 30 50 30
KINGSVILLE 77 96 77 94 77 / 10 20 30 50 30
NAVY CORPUS 80 88 80 91 78 / 10 30 30 50 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
631 PM CDT SUN JUL 14 2013
.DISCUSSION...SEE AVIATION DISCUSSION BELOW FOR THE 00Z TAFS.
&&
.AVIATION...AS OF 625 PM CDT...RADAR WAS INDICATING SHRA/TSRA`S N
OF THE CWA MOVG S. THERE IS SOME UNCERTAINTY AS TO HOW FAR S THIS
ACTIVITY WILL MOVE DUE TO THE AFFOREMENTIONED REASONS IN THE
PREVIOUS DISCUSSION BELOW. GIVEN THE PROXIMITY OF THE CONVECTION
TO VCT...DECIDED TO INCLUDE A TEMPO WITH TSRA UNTIL 02Z.
OTHERWISE...CIGS/VSBYS ARE EXPECTED TO BE AT VFR LEVELS THROUGH
MUCH OF THE TAF PERIOD. INCREASING MOISTURE THROUGH MON MAY LEAD
TO ISOLD/SCT SHRA`S ALONG THE SEA BREEZE AND ADDITIONAL CONVECTION
POSSIBLY MOVING INTO THE NRN CWA FROM THE HILL COUNTRY. FOR NOW
WENT WITH VCSH FOR THE LATTER PART OF THE VCT TAF WHERE CHCS ARE
BEST.
&&
.PREV DISCUSSION... /ISSUED 619 PM CDT SUN JUL 14 2013/
DISCUSSION...LAPS DATA AND HRRR MODEL DATA STILL SUGGESTING THAT
CONVECTION ALONG THE BOUNDARY SHOULD WEAKEN AND DISSIPATE BEFORE
IT GETS MUCH FARTHER EAST. STILL...ACTIVITY STILL GETTING A BIT
TOO CLOSE TO VICTORIA AREA NOT TO INCREASE POPS AT LEAST INTO THE
CHANCE CATEGORY. LAPS NOW SHOWING A BIT OF A CAP STARTING TO FORM
JUST SOUTH OF VICTORIA...WE WILL SEE IF THIS IS ENOUGH. IN ANY
CASE...DECIDED TO UPDATE FORECAST FOR AFOREMENTIONED ACTIVITY.
WILL MONITOR FOR FURTHER UPDATES AS NEEDED. PRODUCTS ARE OUT.
PREV DISCUSSION... /ISSUED 328 PM CDT SUN JUL 14 2013/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN AREA OF SHOWERS
AND THUNDERSTORMS IS CURRENTLY LOCATED OVER EAST CENTRAL TEXAS.
ADDITIONAL CONVECTION HAS DEVELOPED ALONG SOUTHWARD MOVING
BOUNDARY OVER SOUTH CENTRAL TEXAS...AND THIS ACTIVITY MAY MOVE
INTO THE REGION LATER THIS AFTERNOON/EVENING. LATEST LAPS DATA
SHOWS CAPE VALUES BETWEEN 1500 AND 2000 J/KG OVER THE EASTERN
PARTS OF THE CWA. IF CONVECTION CAN CONTINUE TO MOVE SOUTHWARD
INTO THE AREA...THEN A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAINFALL COULD BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING
MAINLY OVER THE NORTHERN AND NORTHEAST ZONES. CURRENT FORECAST HAS
THIS ACCOUNTED FOR THE SLIGHT END POPS OVER THESE LOCATIONS.
MOISTURE AND CLOUD COVER INCREASES FURTHER TONIGHT AND ALONG WITH
CONTINUED SOUTHERLY WINDS SHOULD LEAD TO A WARM NIGHT ACROSS SOUTH
TEXAS. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 70S AND INCREASED
TEMPS OVER MAVMOS VALUES. UPPER LOW WILL CONTINUE TO TRACK
WESTWARD ACROSS OKLAHOMA AND NORTH TEXAS ON MONDAY. WEAKNESS IN
FLOW ALOFT WITH LITTLE TO NO CAPPING SHOULD ONCE AGAIN PROVE
SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT. HIGHEST
CHANCES WILL BE OVER THE VICTORIA CROSSROADS WHERE BETTER MOISTURE
WILL RESIDE. HIGHS ON MONDAY WILL BE SET BACK A FEW DEGREES
(THOUGHT STILL IN THE 90S) DUE TO CLOUD COVER AND RAIN CHANCES...
AND HAVE EITHER GONE WITH OR UNDERCUT GUIDANCE BY A FEW DEGREES.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN FORECAST CHALLENGE FOR
TODAY CONTINUES TO BE POP PLACEMENT/COVERAGE THROUGH THE WORK WEEK.
ALL GUIDANCE SUITES CONTINUE TO ADVERTISE POTENTIALLY WET WEEK FOR
SOUTH TEXAS AS DEEP TROPICAL MOISTURE IS PROG TO EXIST FROM TUESDAY
THROUGH THURS/FRI. THE INTERACTION BETWEEN THE DEEP MOISTURE...
PERIODIC POS VORT ADVECTION...WEAK ELONGATED TUTT SIGNATURE...WEAK
SURFACE TROUGHING...AND ANY MESOSCALE BOUNDARIES /OUTFLOW
BOUNDARIES AND SEABREEZE...SHOULD ALL LEAD TO A SCATTERING OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY THROUGH THURSDAY. TUESDAY/S
PRECIP CHANCES SHOULD BE BASED ON PIECE OF H5 VORTICITY DRIFTING
OUT OF OLD MEX AND INTERACTING WITH UNSTABLE AIRMASS AND DEEP
MOISTURE THAT SHOULD ALREADY BE IN PLACE. WED AND THURSDAY/S
CHANCES ARE BASED ON WEAK INVERTED SURFACE TROUGH AND WEAK TUTT
STRETCHING INTO THE REGION...WHICH ONCE AGAIN SHOULD LEAD TO A
SCATTERING OF SHOWERS AND THUNDERSTORMS. GIVEN DEEP MOISTURE OF
AOA 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS
WEEK...BUT AT THIS TIME WIDESPREAD FLOODING RAINS ARE NOT
EXPECTED. SLIGHT CHANCES OF PRECIP MAY CONTINUE FRIDAY AND INTO
NEXT WEEKEND...BUT WILL BE DEPENDENT ON HOW MUCH DRIER AIR CAN
WORK ITS WAY INTO THE AREA AS H85 HIGH SHIFTS FARTHER EAST FROM
THE MIDWEST TO THE SE COAST. MAX TEMPS THIS WEEK WILL BE STRONGLY
DEPENDENT ON COVERAGE OF PRECIP AND CLOUD COVER...FOR NOW HAVE
GONE A LITTLE ON THE WARM SIDE GIVEN THAT WE SHOULD NOT HAVE
WIDESPREAD CLOUD COVER EVERY DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 94 77 94 77 / 10 30 30 50 30
VICTORIA 76 91 75 93 74 / 30 50 30 50 30
LAREDO 79 98 78 97 78 / 10 20 30 50 30
ALICE 75 96 76 94 75 / 10 20 30 50 30
ROCKPORT 80 88 79 92 77 / 20 30 30 50 40
COTULLA 76 96 76 97 75 / 10 20 30 50 30
KINGSVILLE 77 96 77 94 77 / 10 20 30 50 30
NAVY CORPUS 80 88 80 91 78 / 20 30 30 50 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TE/81...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
619 PM CDT SUN JUL 14 2013
.DISCUSSION...LAPS DATA AND HRRR MODEL DATA STILL SUGGESTING THAT
CONVECTION ALONG THE BOUNDARY SHOULD WEAKEN AND DISSIPATE BEFORE
IT GETS MUCH FARTHER EAST. STILL...ACTIVITY STILL GETTING A BIT
TOO CLOSE TO VICTORIA AREA NOT TO INCREASE POPS AT LEAST INTO THE
CHANCE CATEGORY. LAPS NOW SHOWING A BIT OF A CAP STARTING TO FORM
JUST SOUTH OF VICTORIA...WE WILL SEE IF THIS IS ENOUGH. IN ANY
CASE...DECIDED TO UPDATE FORECAST FOR AFOREMENTIONED ACTIVITY.
WILL MONITOR FOR FURTHER UPDATES AS NEEDED. PRODUCTS ARE OUT.
&&
.PREV DISCUSSION... /ISSUED 328 PM CDT SUN JUL 14 2013/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN AREA OF SHOWERS
AND THUNDERSTORMS IS CURRENTLY LOCATED OVER EAST CENTRAL TEXAS.
ADDITIONAL CONVECTION HAS DEVELOPED ALONG SOUTHWARD MOVING
BOUNDARY OVER SOUTH CENTRAL TEXAS...AND THIS ACTIVITY MAY MOVE
INTO THE REGION LATER THIS AFTERNOON/EVENING. LATEST LAPS DATA
SHOWS CAPE VALUES BETWEEN 1500 AND 2000 J/KG OVER THE EASTERN
PARTS OF THE CWA. IF CONVECTION CAN CONTINUE TO MOVE SOUTHWARD
INTO THE AREA...THEN A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAINFALL COULD BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING
MAINLY OVER THE NORTHERN AND NORTHEAST ZONES. CURRENT FORECAST HAS
THIS ACCOUNTED FOR THE SLIGHT END POPS OVER THESE LOCATIONS.
MOISTURE AND CLOUD COVER INCREASES FURTHER TONIGHT AND ALONG WITH
CONTINUED SOUTHERLY WINDS SHOULD LEAD TO A WARM NIGHT ACROSS SOUTH
TEXAS. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 70S AND INCREASED
TEMPS OVER MAVMOS VALUES. UPPER LOW WILL CONTINUE TO TRACK
WESTWARD ACROSS OKLAHOMA AND NORTH TEXAS ON MONDAY. WEAKNESS IN
FLOW ALOFT WITH LITTLE TO NO CAPPING SHOULD ONCE AGAIN PROVE
SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT. HIGHEST
CHANCES WILL BE OVER THE VICTORIA CROSSROADS WHERE BETTER MOISTURE
WILL RESIDE. HIGHS ON MONDAY WILL BE SET BACK A FEW DEGREES
(THOUGHT STILL IN THE 90S) DUE TO CLOUD COVER AND RAIN CHANCES...
AND HAVE EITHER GONE WITH OR UNDERCUT GUIDANCE BY A FEW DEGREES.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN FORECAST CHALLENGE FOR
TODAY CONTINUES TO BE POP PLACEMENT/COVERAGE THROUGH THE WORK WEEK.
ALL GUIDANCE SUITES CONTINUE TO ADVERTISE POTENTIALLY WET WEEK FOR
SOUTH TEXAS AS DEEP TROPICAL MOISTURE IS PROG TO EXIST FROM TUESDAY
THROUGH THURS/FRI. THE INTERACTION BETWEEN THE DEEP MOISTURE...
PERIODIC POS VORT ADVECTION...WEAK ELONGATED TUTT SIGNATURE...WEAK
SURFACE TROUGHING...AND ANY MESOSCALE BOUNDARIES /OUTFLOW
BOUNDARIES AND SEABREEZE...SHOULD ALL LEAD TO A SCATTERING OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY THROUGH THURSDAY. TUESDAY/S
PRECIP CHANCES SHOULD BE BASED ON PIECE OF H5 VORTICITY DRIFTING
OUT OF OLD MEX AND INTERACTING WITH UNSTABLE AIRMASS AND DEEP
MOISTURE THAT SHOULD ALREADY BE IN PLACE. WED AND THURSDAY/S
CHANCES ARE BASED ON WEAK INVERTED SURFACE TROUGH AND WEAK TUTT
STRETCHING INTO THE REGION...WHICH ONCE AGAIN SHOULD LEAD TO A
SCATTERING OF SHOWERS AND THUNDERSTORMS. GIVEN DEEP MOISTURE OF
AOA 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS
WEEK...BUT AT THIS TIME WIDESPREAD FLOODING RAINS ARE NOT
EXPECTED. SLIGHT CHANCES OF PRECIP MAY CONTINUE FRIDAY AND INTO
NEXT WEEKEND...BUT WILL BE DEPENDENT ON HOW MUCH DRIER AIR CAN
WORK ITS WAY INTO THE AREA AS H85 HIGH SHIFTS FARTHER EAST FROM
THE MIDWEST TO THE SE COAST. MAX TEMPS THIS WEEK WILL BE STRONGLY
DEPENDENT ON COVERAGE OF PRECIP AND CLOUD COVER...FOR NOW HAVE
GONE A LITTLE ON THE WARM SIDE GIVEN THAT WE SHOULD NOT HAVE
WIDESPREAD CLOUD COVER EVERY DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 77 94 77 94 77 / 10 30 30 50 30
VICTORIA 76 91 75 93 74 / 30 50 30 50 30
LAREDO 79 98 78 97 78 / 10 20 30 50 30
ALICE 75 96 76 94 75 / 10 20 30 50 30
ROCKPORT 80 88 79 92 77 / 20 30 30 50 40
COTULLA 76 96 76 97 75 / 10 20 30 50 30
KINGSVILLE 77 96 77 94 77 / 10 20 30 50 30
NAVY CORPUS 80 88 80 91 78 / 20 30 30 50 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
GW/86...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
605 PM CDT SUN JUL 14 2013
.AVIATION...
ANOTHER BAND OF SHOWERS AND ISOLATED THUNDERSTORMS MAY DEVELOP NORTH
OF THE CWA AND TRANSLATE SOUTHWARD THIS EVENING. HAVE GONE AHEAD AND
ADDED A TEMPO GROUP AT ALL TAF SITES FOR -SHRA AND MVFR CIGS THIS
EVENING FOR A 4 HOUR TIME PERIOD. AFTER THE SHOWERS PASS...MVFR CIGS
WILL PREVAIL AT GUY AND DHT WITH IFR CIGS AT AMA. THE LOW CLOUDS ARE
EXPECTED TO DECREASE BY LATE MORNING ON MONDAY AND A VFR CLOUD LAYER
WILL PREVAIL FOR THE REST OF THE FORECAST. GUSTY SOUTHEAST WINDS WILL
DECREASE LATE THIS EVENING AND THEN THEY WILL BECOME MORE EASTERLY
AFTER 06Z. MORE SHOWERS AND THUNDERSTORMS MAY DEVELOP MONDAY
AFTERNOON WITH AMA BEING THE MOST FAVORED...BUT CONFIDENCE IS NOT
HIGH ENOUGH TO ADD TO THE TAF AT THIS POINT.
&&
.PREV DISCUSSION... /ISSUED 310 PM CDT SUN JUL 14 2013/
SHORT TERM...
COLD FRONT NOW THROUGH ALL OF THE PANHANDLES AS OF 3 PM CDT. IN ITS
WAKE...DECREASING TEMPERATURES AND SCATTERED SHOWERS ACROSS.
FOR TONIGHT...SHOULD SEE COVERAGE OF SHOWERS INCREASE A BIT AND HIGH
RESOLUTION MODELS LIKE THE HRRR AND TTU WRF CONTINUE TO SHOW THIS
TREND. WITH VERY LIMITED INSTABILITY...EXPECT THE ACTIVITY TO
PRIMARILY BE LIGHT RAIN SHOWERS...THOUGH AN ISOLATED THUNDERSTORM IS
POSSIBLE.
TOMORROW THROUGH TUESDAY...EXPECT A LULL IN THE PRECIP STARTING SOMETIME
EARLY TOMORROW MORNING AND CONTINUING THROUGH MID DAY AS THE REGION
WILL BE ON THE DRIER NW SIDE OF THE LOW. AS THE LOW CONTINUES TO
SLIDE EAST TOMORROW NIGHT...EXPECT PRECIP TO SPREAD FROM EAST TO WEST
ONCE AGAIN...AS BETTER LIFT IS EXPECTED ON THE EASTERN SIDE OF THE
UPPER LEVEL LOW. STILL SOME QUESTION AS TO HOW FAR NORTH MOISTURE
WILL ADVECT AND IF CONVECTION FURTHER DOWN STATE WILL ROB SOME OF THE
MOISTURE ADVECTION FOR THE PANHANDLES. STILL THINK THE BEST CHANCE
WILL BE TOMORROW NIGHT...WITH CHANCES DECREASING AFTER THAT.
LONG TERM...
WEDNESDAY THROUGH THURSDAY...COULD STILL SEE SOME LINGERING
CONVECTION EVEN THOUGH THE LOW WILL BE PROPAGATING OVER NORTHERN
MEXICO BY THIS POINT...THE RESULTING MID AND UPPER LEVEL
SOUTHEASTERLY FLOW SHOULD RESULT IN A MOIST FETCH FROM THE GULF.
FRIDAY THROUGH SUNDAY...CONSIDERABLE UNCERTAINTY IN THE UPPER LEVEL
PATTERN THROUGH THIS PERIOD. GFS SHOWS VERY WEAK FLOW OVER THE REGION
THROUGH THIS PERIOD...WITH THE HIGH BUILDING OVER THE WESTERN U.S.
WHILE THE ECMWF SHOWS THE HIGH BUILDING OVER THE ROCKIES THEN SLIDING
SE TOWARDS THE PANHANDLES. EITHER WAY...IT SHOULD BE A DRIER
PATTERN...WITH THE POSSIBLE EXCEPTION OF SOME MOUNTAIN CONVECTION
SLIDING INTO THE NW CORNER ON SATURDAY UNDER VERY WEAK NW FLOW.
JOHNSON
FIRE WEATHER...
MUCH COOLER WEATHER...RAIN CHANCES...AND RELATIVE HUMIDITY VALUES
WELL ABOVE 20 PERCENT WILL PRECLUDE ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS FOR THE NEXT SEVERAL DAYS.
JOHNSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/11
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1005 PM PDT Fri Jul 12 2013
.SYNOPSIS...
Occasionally breezy conditions with near or slightly below normal
temperatures is expected through Saturday. There will be a
slight chance of showers and thunderstorms for tonight into Saturday,
especially around the northern mountains. Warmer temperatures are
expected next week with dry conditions except for a slight chance of
thunderstorms Tuesday night into Wednesday morning.
&&
.DISCUSSION...
Radar showing enhancement in vicinity of Omak and the HRRR runs
from the past three hours of so suggest this is the beginning of
elevated forced convection that should continue through the
overnight hours. Thus have left the mention of thunderstorms but
also added more mention of sprinkles further west with this late
evening update.
&&
.AVIATION...
06Z TAFS: Cold front passage tonight keeps cloud cover and wind
fairly moderate at times along with some overnight and early
morning thunderstorms over northern mountains...otherwise VFR
ceilings and visibilities through this interval. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 52 77 54 82 56 86 / 10 10 0 0 0 0
Coeur d`Alene 49 78 51 81 52 85 / 10 10 0 0 0 0
Pullman 47 76 51 83 51 85 / 10 10 0 0 0 0
Lewiston 57 85 59 91 60 95 / 10 10 0 0 0 0
Colville 48 82 51 84 51 88 / 20 10 0 0 0 0
Sandpoint 44 75 47 80 47 82 / 10 20 10 10 10 0
Kellogg 50 75 51 81 54 84 / 10 10 0 0 0 0
Moses Lake 53 83 56 89 57 90 / 10 0 0 0 0 0
Wenatchee 55 82 60 86 60 88 / 10 0 0 0 0 0
Omak 52 83 55 87 56 88 / 10 10 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
621 PM CDT SUN JUL 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
MAIN FORECAST CONCERN IS ON THUNDERSTORM POTENTIAL FOR MONDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHARP SHORTWAVE TROUGH OVER BRITISH COLUMBIA...AN UPPER LOW
OVER EASTERN OKLAHOMA...A SHORTWAVE TROUGH STRETCHING FROM NORTHERN
MN INTO EASTERN SOUTH DAKOTA...AND THE BERMUDA HIGH OVER THE EASTERN
GREAT LAKES. 500MB HEIGHTS ASSOCIATED WITH THE BERMUDA HIGH ARE
QUITE IMPRESSIVE...NEARING 600 DAM OR 2.5 STANDARD DEVIATIONS ABOVE
NORMAL. DESPITE THE SUBSTANTIAL 500MB HEIGHTS...850MB TEMPS ARE ONLY
IN THE 15-18C UNDERNEATH IT PER 12Z RAOBS OR NEAR 1 STANDARD
DEVIATION ABOVE NORMAL. THE WESTERN EXTENT OF THE SUBTROPICAL RIDGE
HAS BEEN PROVIDING SUBSIDENCE OVER THE FORECAST AREA...RESULTING IN
DRY CONDITIONS WITH JUST SOME DIURNAL CUMULUS CLOUDS. TO OUR
WEST...A STREAM OF PRECIPITABLE WATER VALUES OF 1.65 TO 2 INCHES
PER GOES DERIVED IMAGERY STRETCHED FROM CENTRAL OKLAHOMA TO
EASTERN SOUTH DAKOTA AND NORTHERN MN. THIS STREAM OF HIGH MOISTURE
IS CO-LOCATED WITH THAT SHORTWAVE TROUGH IN THE NORTHERN PLAINS
AND DEFORMATION ON THE WEST SIDE OF THE UPPER LOW. NUMEROUS
SHOWERS AND THUNDERSTORMS WERE PRESENT IN THE STREAM.
EXPECT THE RETROGRADING 500MB PATTERN TO CONTINUE THROUGH THE SHORT
TERM PERIOD...SUCH THAT BY 00Z TUESDAY MODELS FORECAST THE BERMUDA
HIGH TO BE SITUATED NEAR THE OHIO/INDIANA BORDER. THIS RETROGRESSION
MEANS 500MB HEIGHTS ARE GOING TO RISE OVER THE FORECAST AREA...
IMPLYING SUBSIDENCE. NOT ANTICIPATING ANY PRECIPITATION TONIGHT
BEING IN THE NOCTURNAL COOLING PERIOD AND RISING HEIGHTS ALOFT. ON
MONDAY...DESPITE BEING UNDER THE SUBSIDENCE OF THE RISING HEIGHTS
ALOFT...NEARLY EVERY MODEL DEPICTS ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT BETWEEN 18Z-00Z OVER THE FORECAST AREA.
THE REASONING FOR THE PRECIPITATION IS A COMBINATION OF FACTORS:
1. SOUTHEAST WINDS ADVECTING IN 70+ SURFACE DEWPOINTS...WHICH ARE
ACCOMPANYING THE BERMUDA HIGH AND ENHANCED BY EVAPOTRANSPORATION
FROM VEGETATION.
2. STREAM OF HIGHER PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES
COMING UP OUT OF GEORGIA AND ALABAMA CURRENTLY.
3. DAYTIME HEATING COMBINING WITH THE HIGHER DEWPOINTS TO BUILD UP
INSTABILITY. MIXING TO 850MB TEMPS OF 16-17C SHOULD YIELD HIGHS IN
THE MID TO UPPER 80S.
4. SOUNDINGS DEPICT NO CAPPING
LOOKING AT VARIOUS PRESSURE LEVELS FOR CONVERGENCE...IT IS VERY
DIFFICULT TO FIND ANY. THUS...IT APPEARS THE LACK OF CAPPING AND THE
HIGHER DEEPER MOISTURE ITSELF WILL RESULT IN POP UP SHOWERS AND
THUNDERSTORMS. 0-6KM SHEAR VALUES OF LESS THAN 20 KT MEANS THESE
STORMS ARE GOING TO BE PULSE AND NON-SEVERE...WITH OUTFLOWS
PRODUCING ADDITIONAL SHOWERS AND THUNDERSTORMS. MAIN CONCERN WITH
THIS PRECIPITATION IS BRIEF HEAVY RAIN GIVEN THE PRECIPITABLE WATER
VALUES AND DEEP WARM CLOUD DEPTHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
THE RETROGRESSION 500MB PATTERN CONTINUES FROM THE SHORT TERM PERIOD
RIGHT INTO NEXT WEEKEND. 14.12Z ECMWF/CANADIAN/GFS AND 14.00Z ECMWF
ENSEMBLE MEAN ALL SHOW THAT THE BERMUDA HIGH WILL SLOWLY MOVE
WESTWARD THROUGH THE WEEK...SUCH THAT BY LATE FRIDAY INTO THE
WEEKEND TROUGHING DOMINATES MUCH OF CANADA INTO THE WESTERN GREAT
LAKES REGION.
MONDAY NIGHT THROUGH WEDNESDAY...
CONVECTION THAT FORMED MONDAY AFTERNOON SHOULD DISSIPATE PRETTY
QUICK IN THE EVENING...LIKELY BY 03Z...AS THE LOSS OF DAYTIME
HEATING DIMINISHES THE INSTABILITY. THE REST OF THE NIGHT INTO
TUESDAY MORNING LOOKS DRY WITH THE MAIN FORCING FOR NOCTURNAL
CONVECTION WELL OFF TO THE NORTHWEST IN THE DAKOTAS. A SIMILAR SETUP
TO MONDAY AFTERNOON LOOKS TO OCCUR FOR TUESDAY AFTERNOON WITH
DEWPOINTS IN THE UPPER 60S TO LOW 70S...HIGHS A FEW DEGREES WARMER
GIVEN 850MB TEMPS PROGGED BETWEEN 18-19C...AND HIGHER CAPE VALUES
DUE TO THESE READINGS. HOWEVER...MODELS ARE MUCH LESS AGGRESSIVE
WITH QPF...AND THIS APPEARS TO STEM FROM PRECIPITABLE WATER VALUES
THAT ARE 0.25-0.5 INCH LOWER. GIVEN THAT THE 14.12Z NAM WHICH IS
USUALLY AGGRESSIVE IN THESE SCENARIOS AND HAPPENS TO BE DRY...AND
COLLABORATION WITH SURROUNDING OFFICES...WENT DRY FOR TUESDAY.
SHOWERS AND THUNDERSTORMS STILL LOOK POSSIBLE NORTH AND EAST OF THE
FORECAST AREA...ASSOCIATED WITH LAKE BREEZES RUNNING INTO THE
UNSTABLE AIR. A COMPLETE REPEAT OF THE WEATHER HAPPENS TUESDAY NIGHT
AND WEDNESDAY...AND HERE AGAIN MODELS ARE NOT THAT AGGRESSIVE WITH
QPF WEDNESDAY AFTERNOON STEMMING FROM SIMILAR PRECIPITABLE WATER
VALUES TO TUESDAY. REMOVED THE 20 PERCENT CHANCES FOR WEDNESDAY.
SAFE TO SAY THAT IF INDEED NO PRECIPITATION HAPPENS TUESDAY...
WEDNESDAY WILL END UP DRY TOO. HIGHS ON WEDNESDAY ARE LIKELY TO BE
SIMILAR TO TUESDAY WITH 850MB TEMPS HOVERING AROUND 19C...YIELDING
READINGS IN THE UPPER 80S TO LOWER 90S.
WITH TUESDAY AND WEDNESDAY AFTERNOON DEWPOINTS IN THE UPPER 60S TO
LOWER 70S AND HIGHS IN UPPER 80S TO LOWER 90S...HEAT INDICES ARE
LIKELY TO CLIMB INTO THE 95-100 RANGE. THESE ARE JUST UNDER HEAT
ADVISORY CRITERIA. SHOULD EITHER DEWPOINTS OR TEMPERATURES GET
HIGHER THAN FORECAST...HEAT ADVISORIES MAY BE REQUIRED.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE PROGGED SWITCH IN THE UPPER FLOW TO MORE NORTHWESTERLY ALLOWS
A COLD FRONT SITUATED OVER NORTHERN MN AND UPPER MI ON WEDNESDAY
TO SLOWLY DRIFT SOUTH. THE TIMING OF WHEN THIS BOUNDARY CROSSES
THE FORECAST AREA LOOKS TO BE MODULATED BY A SHORTWAVE DROPPING
THROUGH NORTH DAKOTA...WHICH COULD STALL OR EVEN SEND THE FRONT
BACK NORTHWARD THURSDAY NIGHT AS SUGGESTED BY THE 14.00Z/14.12Z
ECMWF. MOST MODELS AGREE ON A TIMING OF THE COLD FRONT CROSSING
THE AREA FRIDAY INTO FRIDAY EVENING...WITH PERHAPS THE FRONT
COMING INTO NORTHERN SECTIONS OF THE FORECAST AREA WEDNESDAY
NIGHT. GIVEN PLENTIFUL INSTABILITY IN PLACE AHEAD OF AND AROUND
THE BOUNDARY...AS WELL AS A PLUME OF HIGHER PRECIPITABLE WATER
VALUES ON THE ORDER OF 1.75-2 INCHES...DEFINITELY NEED CHANCES OF
SHOWERS AND THUNDERSTORMS. THERE ARE INDICATIONS OF POSSIBLE MCS
ACTIVITY TOO...ESPECIALLY THURSDAY AFTERNOON AND NIGHT NORTH OF
I-90 WHICH IS WHERE CHANCES OF PRECIPITATION ARE ON THE ORDER OF
50-60. ONE PORTION OF THE FORECAST WHERE CHANCES MAY BE ABLE TO BE
REMOVED IS FRIDAY NIGHT...SINCE THERE ARE SOME INDICATIONS OF THE
FRONT AND ASSOCIATED CONVECTION GETTING OUT OF THE AREA IN TIME.
HIGH PRESSURE BUILDS IN FOR SATURDAY AND SATURDAY NIGHT...BRINGING
DRIER CONDITIONS. UNCERTAINTY INCREASES FOR SUNDAY WITH
INDICATIONS OF SOME SHORTWAVE TROUGH DROPPING THROUGH IN THE
NORTHWEST FLOW. HAVE FOLLOWED A MODEL CONSENSUS OF 20-40 PERCENT
CHANCES FOR NOW.
SOME SEVERE WEATHER IS POSSIBLE THURSDAY THROUGH FRIDAY...WITH 0-6KM
SHEAR VALUES PROGGED OF 30-35 KT ALONG THE COLD FRONT. DAMAGING
WINDS AND HEAVY RAIN WOULD APPEAR TO BE THE MAIN HAZARDS. LOCATIONS
NORTH OF I-90 SEEM TO BE CENTERED ON HAVING THE MOST RAIN DURING
THIS PERIOD...WHICH IS AN AREA THAT NOT ONLY CAN HANDLE THE RAIN BUT
NEEDS IT.
TEMPERATURES THURSDAY THROUGH FRIDAY ARE QUITE TRICKY. 850MB TEMPS
UPWARDS OF 20C COULD EASILY SUPPORT HIGHS IN THE LOW TO EVEN PERHAPS
MID 90S...AND WITH DEWPOINTS UP IN THE LOW 70S WOULD YIELD HEAT
INDICES AGAIN IN THE 95-100 RANGE. HOWEVER...THERE IS CONVECTION TO
WORRY ABOUT...ESPECIALLY ON FRIDAY. THUS...HIGH TEMPERATURES ARE
ONLY FORECAST IN THE MID 80S TO LOW 90S AT THIS TIME. 850MB TEMPS
FALLING INTO THE 13-15C RANGE FOR SATURDAY AND ONLY CLIMBING ABOUT
1C HIGHER ON SUNDAY WILL RESULT IN COOLER TEMPERATURES...UPPER 70S
TO MID 80S.
&&
.AVIATION...TONIGHT AND MONDAY
620 PM CDT SUN JUL 14 2013
AREA UNDER THE INFLUENCE OF HIGH PRESSURE TONIGHT. DIURNAL CUMULUS
ALL BUT DISSIPATED ALREADY AND SHOULD BE MAINLY CLEAR ALL NIGHT.
LOW LEVEL MOISTURE IS INCREASING NOW THAT THE SHORT WAVE TROUGH
HAS MOVED TO OUR SOUTHWEST AND ALLOWED SOUTHERLY WINDS TO RETURN
WITH AN INCREASING FEED OF GULF MOISTURE. COULD BE SOME LIGHT
MIST AROUND AGAIN FOR A FEW HOURS AROUND SUNRISE...THEN CUMULUS
DEVELOPMENT BY LATE MORNING. AS INSTABILITY INCREASES IN THE
AFTERNOON...EXPECT SOME SHOWERS TO FORM SIMILAR TO WHAT HAS
HAPPENED OVER ILLINOIS TODAY. THIS ACTION MAY END UP BEING
SOUTH OF THE TAF SITES...BUT COULD BE SOME IN THE LOCAL AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
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
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 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
NWS CHEYENNE WY
848 PM MDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 848 PM MDT SUN JUL 14 2013
OVERALL AN UNEVENTFUL EVENING ACROSS THE CWA...DESPITE THE SURFACE
DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES THAT ARE
RUNNING 150 TO 200 PERCENT OF NORMAL. THICKER DAYTIME CLOUD COVER
CERTAINLY THWARTED SOME OF THE INSTABILITY. BUT THE PRIMARY
HINDRANCE HAS BEEN THE LACK OF A TRIGGER. THE ORIGINAL THOUGHT WAS
THAT OROGRAPHIC ASCENT WOULD BE SUFFICIENT IN CONVECTIVE
DEVELOPMENT...WHICH OBVIOUSLY HAS NOT BEEN THE CASE. OUTSIDE OF
A FEW ISOLATED THUNDERSTORMS...MUCH OF THE CWFA HAS REMAINED DRY.
INITIAL LOOK AT 00Z GUIDANCE SHOWS ANY HOPE OF CONVECTION FADING
THROUGH THE OVERNIGHT HOURS AS RIBBON OF MOISTURE THINS AS IT
BACKS TO THE WEST THROUGH THE CWA. COULD STILL SEE SOME SHOWERS
AND EVEN EMBEDDED THUNDER DEVELOP THRU THE NIGHT...BUT ANY HOPE IS
QUICKLY FADING. SO...IN AN EARLIER UPDATE BEGAN SCALING BACK
PRECIPITATION CHANCES ACROSS THE ENTIRE AREA TONIGHT. THE OTHER
CONCERN IS THE POTENTIAL FOR FOG DEVELOPMENT AFTER MIDNIGHT GIVEN
THE VERY MOIST LLVLS. BOTH THE SREF AND HRRR ARE POINTING TO ITS
DEVELOPMENT ALONG THE LARAMIE RANGE AND ADJACENT EASTERN
FOOTHILLS. GIVEN ESE LLVL FLOW...THIS SEEMS TO BE PLAUSIBLE. SO
HAVE ADDED AREAS OF FOG ACROSS MOST OF THE EASTERN PLAINS FOR LATE
TONIGHT AND EARLY MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
VERY MOIST AIRMASS IS CURRENTLY OVER THE CWA WITH MANY AREAS TO
THE EAST OF THE LARAMIE RANGE SEEING 60S DEWPOINTS. THE EXTENSIVE
LOW AND MIDLEVEL CLOUD COVER THAT HAS OCCURRED THROUGH THE EARLY
AFTERNOON HAS LIMITED SFC HEATING AND INSTABILITY. HOWEVER...VISIBLE
IMAGERY SHOWS THE PLAINS STARTING TO CLEAR AND LAPS ANALYSIS
INDICATES WIDESPREAD 500-1000 J/KG OF CAPE. BELIEVE THERE COULD BE
AN UPTICK IN CONVECTIVE ACTIVITY DURING THE EARLY EVENING OVER THE
SOUTHERN ZONES DESPITE THE LATE START. THE SFC TROUGH AND
ASSOCIATED HIGHEST DEWPOINT/PW VALUES IS JUST TO THE EAST OF THE
CWA AND IS PROGGED TO CONTINUE MOVING WESTWARD THROUGH THE NIGHT.
THE MOST IMPRESSIVE CONVECTION IS CURRENTLY IN THE CONVERGENCE
ALONG THAT TROUGH...OUTFLOW FROM THIS CONVECTION SHOULD BE ABLE TO
INITIATE CONVECTION IN THE SOUTHERN PANHANDLE DURING THE EVENING.
STILL HAVE HEAVY RAIN IN THE GRIDS THROUGH THE NIGHT WITH PW
VALUES AROUND 1.3 INCHES AND SLOW STEERING FLOW (700-300MB FLOW IS
AROUND 5-10 KTS). AREAS IN SCOTTS BLUFF COUNTY PICKED UP AROUND 2
INCHES OF RAINFALL IN A FEW HOURS EARLIER THIS AFTERNOON...A
TESTAMENT TO THE HEAVY RAIN POTENTIAL. THE PW RIDGE AXIS IS IN
EXTREME SOUTHEAST WY BY MONDAY MORNING SO CONTINUED THE THREAT OF
SHOWERS THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
UPPER LOW AND ITS ASSOCIATED MIDLEVEL MOISTURE PLUME CONTINUE TO
MOVE WESTWARD ON MONDAY. PW VALUES ARE HIGHEST (AROUND 1 INCH)
ACROSS SOUTHEAST WY WITH A CONSIDERABLE DROP IN THE PANHANDLE.
HAVE CHANCE POPS MAINLY ALONG AND WEST OF THE LARAMIE RANGE DURING
THE AFTN AND EVENING...NOT EXPECTING MUCH FURTHER EAST. STEERING
FLOW CONTINUES TO BE WEAK SO THE HEAVY RAIN THREAT WILL BE
THERE...ESPECIALLY IN THE HIGHER TERRAIN WHERE COVERAGE OF STORMS
WILL BE BEST. TEMPS WARM AROUND 5 DEGREES ON MONDAY WITH LESS
CLOUD COVER...ESPECIALLY IN NEBRASKA. THE DRYING TREND THAT HAS
BEEN PROGGED FOR TUESDAY CONTINUES TO LOOK ON TRACK. WITH PW
VALUES AT 0.5-0.75 INCHES AND LI VALUES ON THE GFS STRUGGLING TO
GET NEGATIVE...STORM POTENTIAL WILL REALLY DROP OFF. SLIGHT CHANCE
POPS ARE CONFINED TO THE SIERRA MADRE AND SNOWY RANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
TUESDAY NIGHT...EVENING THUNDERSTORMS ACROSS THE SIERRA MADRE RANGE
IN UPSLOPE...OTHERWISE DRY.
WEDNESDAY...UPPER RIDGE AXIS OVER OUR COUNTIES. SURFACE LOW AND LOW
LEVEL CONVERGENCE AXIS OVER OUR SNOWY AND SIERRA MADRE RANGES...
WHERE SCATTERED AFTERNOON THUNDERSTORMS ON TAP...DRY ELSEWHERE WITH
SUBSIDENCE AND CONVECTIVE INHIBITION.
THURSDAY...RIDGE ALOFT WEAKENS SLIGHTLY AND WITH SLIGHTLY MORE LOW
AND MID LEVEL MOISTURE...EXPECT SCATTERED AFTERNOON THUNDERSTORMS
OVER THE NORTHERN...SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE.
FRIDAY...MONSOONAL MOISTURE TAP RETURNS OVER OUR COUNTIES AND WITH
LOW LEVEL UPSLOPE WINDS AND PLENTY OF LOW AND MID LEVEL MOISTURE...
WILL SEE SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS OVER THE MOUNTAINS.
SATURDAY...DEEPER MONSOONAL MOISTURE FEED TRANSLATES SOUTH ACROSS
COLORADO...THOUGH STILL ENOUGH MOISTURE FOR ISOLATED TO SCATTERED
LATE DAY THUNDERSTORMS FOCUSED NEAR THE MOUNTAINS.
SUNDAY...DRIER AIRMASS ADVECTS IN ON NORTHWEST FLOW ALOFT...THUS
ONLY ISOLATED LATE DAY THUNDERSTORMS ON TAP OVER THE MOUNTAINS...DRY
ELSEWHERE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY AFTERNOON)
ISSUED AT 548 PM MDT SUN JUL 14 2013
THE MAIN CONCERN THIS EVENING IS WHETHER OR NOT WE WILL SEE ANY
CONVECTION THIS EVENING AND THE POTENTIAL FOR IFR CONDITIONS
OVERNIGHT.
LATEST RADAR LOOP WAS SHOWING THE BULK OF THE SHOWERS AND STORMS
RESIDING OVER SOUTHWEST NEBRASKA AND NORTHEAST COLORADO. HRRR
MODELS IS SHOWING THE BULK OF THIS CONVECTION STAYING TO THE
SOUTHEAST OF FORECAST AREA THIS EVENING. LATEST IR IMAGERY IS
SHOWING THE CLOUD TOP COOLING FURTHER NORTH INTO WESTERN NEBRASKA.
THIS MAKES THIS FORECAST A BIT MORE CHALLENGING THIS
EVENING...ESPECIALLY IF THIS CLUSTER OF THUNDERSTORMS CONTINUES
ITS TRACK WESTWARD. WE HAVE REMOVED THE CHANCE OF THUNDERSTORMS
THIS EVENING ACROSS MOST OF THE TAF SITES THIS EVENING EXCEPT FOR
SNY WHERE THEY MAY SEE THE CLUSTER APPROACH THEM AROUND 02Z OR SO.
ELSEWHERE...WE ARE FOCUSING OUR CONCERN FOR THE POTENTIAL FOR IFR
CEILINGS DEVELOPING OVERNIGHT...DUE TO GOOD UPSLOPE FLOW AND RICH
DEWPOINTS. IN ADDITION...THE CLOUDS WERE VERY TOUCH TO ERODE THIS
AFTERNOON...AND WE WOULD NOT BE SURPRISED IF THE LOW CLOUDS
REDEVELOP AS THE BOUNDARY LAYER COOLS.
&&
.FIRE WEATHER...
ISSUED AT 350 PM MDT SUN JUL 14 2013
NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. A VERY MOIST
AIRMASS IS CURRENTLY AFFECTING THE REGION WITH SCATTERED SHOWERS
AND THUNDERSTORMS POSSIBLE THROUGH THE EARLY NIGHT. THIS MOIST
AIRMASS WILL CONTINUE MOVING WESTWARD WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON AND EVENING...MAINLY
ALONG AND WEST OF THE LARAMIE RANGE. STORM CHANCES WILL REALLY
DROP BY TUESDAY AS MIDLEVEL MOISTURE PUSHES OUT OF THE REGION.
WINDS WILL GENERALLY BE BELOW 20 MPH THROUGH TUESDAY...EXCEPT IN
THE VICINITY OF STORMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAHN
SHORT TERM...FINCH
LONG TERM...RUBIN
AVIATION...REC
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS MIAMI FL
141 AM EDT MON JUL 15 2013
.AVIATION...
MOSTLY VFR CONDITIONS ARE EXPECTED THROUGH THIS FORECAST PERIOD. A
BATCH OF SHOWERS OVER THE ATLANTIC HAVE BEEN WEAKENING AS THEY
APPROACH THE EAST COAST AND THIS TREND WILL CONTINUE OVER THE
FIRST COUPLE OF HOURS. ADDITIONAL DEVELOPMENT WILL OCCUR INLAND
AWAY FROM THE EAST COAST TERMINALS AND MOVE TOWARDS KAPF AFT
15-17Z. SLIGHT DRYING WILL OCCUR TODAY SO NOT EXPECTING THE
WIDESPREAD ACTIVITY FROM THE PAST COUPLE OF DAYS SO ONLY MENTIONED
VCSH ALONG THE EAST COAST AND VCTS TO KAPF WHERE THEY HAVE THE
GREATEST CHANCE FOR A BRIEF MVFR/IFR CIG OR VSBY CONCERN. EAST
SURFACE WIND WILL CONTINUE THROUGH THE PERIOD AND FLUCTUATE IN
SPEED BY A COUPLE OF KNOTS PRIOR TO AND AFTER SUNRISE.
KOB
&&
.PREV DISCUSSION... /ISSUED 1133 PM EDT SUN JUL 14 2013/
UPDATE...THE NEAR TERM FORECAST WAS JUST UPDATED. RADAR TRENDS
SUGGEST WIDESPREAD ACTIVITY WILL AFFECT THE PALM BEACHES OVER THE
NEXT HOUR OR SO, EVEN THOUGH THERE IS A GENERAL WEAKENING TREND IN
THE CONVECTION. FURTHER DOWN THE COAST, IT REMAINS TO BE SEEN HOW
MUCH ACTIVITY WILL MOVE INLAND OVERNIGHT. WINDS ARE LIGHT BUT THE
EASTERLY FLOW IMPINGING INTO THE AREA COULD ALLOW FOR SOME SHRA OR
TSTORMS TO MOVE ONSHORE OVERNIGHT. /GREGORIA
PREV DISCUSSION... /ISSUED 920 PM EDT SUN JUL 14 2013/
UPDATE...
SHOWERS AND THUNDERSTORMS CONTINUE TO DECREASE IN COVERAGE ACROSS
THE SOUTH FLORIDA AREA THIS EVENING WITH SLIGHTLY MORE ORGANIZED
CONVECTION ACROSS THE GULF WATERS. LATEST HRRR CONTINUES TO DEPICT
ACTIVITY WEAKENING THROUGH THE NEXT FEW HOURS. ADJUSTED POP AND
QPF GRIDS SLIGHTLY. UPDATE SENT.
PREV DISCUSSION... /ISSUED 800 PM EDT SUN JUL 14 2013/
AVIATION...
SHORTWAVE RIDGE BUILDING SOUTH OF EAST CST FL AS MODELS HAVE BEEN
ADVERTISING. CURRENTLY HAS YET TO SET IN ACROSS S FL TO PUSH
STORMS WEST. HENCE ACTIVITY INLAND ENDED UP PROPAGATING INTO THE
EAST COAST THIS EVENING. THIS EVENING WILL BE SEEING SOME DIMINISHING TS
OVERNIGHT ALONG EAST COAST TERMINALS WITH BRIEF PERIODS OF MVFR
CIG/VIS NEXT COUPLE OF HOURS AND EVEN VERY BRIEF IFR. OTHERWISE
VFR CONDITIONS THROUGH TOMORROW EVENING OUTSIDE DIMINISHING CHANCES
OF SHOWERS OR STORMS AFFECTING ANY GIVEN TERMINAL AS OUTLINED
NEXT.
GOING DRY FOR A SPELL OVERNIGHT. MESOANALYSIS SHOW AN AREA OF DRY
LOW LEVEL AIR TRYING TO MOVE WEST FROM BAHAMAS BUT WEAKENS AND
OTHERWISE DOESN`T QUITE MAKE IT. SOME SHRA MAY REDEVELOP COASTAL
WATERS AND THINK CHANCES ARE BETTER DURING THE LATE OVERNIGHT
PERIOD FOR EASTERN TERMINALS WHERE LOW LEVEL FLOW SHOULD BE A
LITTLE STRONGER. THIS IS ALL INDICATIVE OF AREA TRANSITIONING TO A
MORE TYPICAL EASTERLY FLOW PATTERN AND WITH THAT WILL MENTION VCSH
OVERNIGHT INTO LATE TOMORROW MORNING OR VERY EARLY AFTERNOON. WITH
LOW LEVEL RIDGE BUILDING IN, ACTIVITY SHOULD TRANSITION AND STAY
INLAND TOMORROW AFTERNOON SO WILL LEAVE VCSH OR VCTS OUT OF THE SE
TERMINALS FOR TOMORROW AFTERNOON EXCEPT AT PBI AND FXE. FOR APF,
ADDED VCSH AND VCTS FROM LATE MORNING ON.
SFC WIND...DCRG EAST FLOW LATE EVENING BCMG ENE AROUND 7KT OR LESS
ALL TERMINALS OVERNIGHT. TOMORROW EAST 7-12KT BY 14-16Z ALL SITES.
PREV DISCUSSION... /ISSUED 241 PM EDT SUN JUL 14 2013/
DISCUSSION...
THE AREA OF PERSISTENT CONVERGENCE AND THUNDERSTORMS THAT HAS
BEEN AFFECTING AREAS AROUND NAPLES THIS MORNING MOVED TO THE
NORTHEAST INTO THE EVERGLADES DURING THE LATE MORNING AND IT IS
NOW AFFECTING AREAS AROUND THE LAKE.
THE 12Z RUN OF THE GFS AND THE LATEST ECMWF PORTRAY THE SAME GENERAL
REASONING THAN THE PAST FEW DAYS: A TROUGH OF LOW PRESSURE OVER THE
CENTRAL US SURROUNDED BY TWO LARGE AREAS OF HIGH PRESSURE. THE
FORECAST STILL CALLS FOR THE AREA OF HIGH PRESSURE IN THE ATLANTIC
TO INTENSIFY AND RETROGRADE OVER THE NE US BETWEEN NOW AND THE
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.
BY THE MIDDLE OF THE WEEK 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 WILL CEASE TO
AFFECT SOUTH FLORIDA AFTER TODAY.
THE STEERING WINDS ARE TRANSITIONING TO THE SOUTHEAST TODAY AND ARE
FORECAST TO REMAIN 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. THIS COULD GENERATE AN
ENHANCEMENT OF MORNING SHOWERS FROM STREAMERS ALONG THE ATLANTIC
COASTAL WATERS AND ENHANCE MOISTURE CONVERGENCE IN THE WEST COAST
DURING THE MORNING HOURS AND POSSIBLY CONCENTRATING THE SHOWER
AND THUNDERSTORM ACTIVITY OVER COLLIER COUNTY IN THE AFTERNOON/EVENING.
WIDESPREAD SHOWERS AND THUNDERSTORMS ARE FORECAST FOR TODAY WITH THE
MAIN CONCENTRATION OVER THE NORTHERN AND WESTERN PORTIONS AS THE
EVENING PROGRESSES. THE INTERACTION OF STORMS WITH OUTFLOW
BOUNDARIES COULD STILL TRIGGER A FEW STORMS OVER THE WESTERN METRO
AREAS THIS AFTERNOON AND EVENING. FOR MONDAY AFTERNOON AND
EVENING THE MAIN CONCENTRATION OF SHOWERS AND STORMS IS EXPECTED FOR
THE INTERIOR AND WEST, AS THE EAST TO SOUTHEAST FLOW GETS
ESTABLISHED.
THE VISIBLE SATELLITE IMAGE SHOWS THE LEADING EDGE OF THE EXPANDING
SUBTROPICAL RIDGE CROSSING THE BAHAMA ISLANDS AROUND 1 PM TODAY. THIS
AREA COINCIDES WITH A DRY SLOT AT 850 MB, AROUND THE HEIGHT OF THE
BASE OF THE SUBTROPICAL INVERSION. ONCE THIS DRY AIR REACHES THE SE
COAST THE CHANCES FOR THUNDERSTORMS WILL DIMINISH SUBSTANTIALLY FOR
THE EAST COAST. HOWEVER, THIS FEATURE IS NOT EXPECTED TO ARRIVE THE
EAST COAST FOR 7 MORE HOURS. FOR NOW HAVE KEPT A 40 PERCENT OF
SHOWERS OVER THE SOUTHERN ATLANTIC WATERS AND A 50 PERCENT FOR THE
EAST COAST METRO AREAS OF MIAMI-DADE. BUT IT IS POSSIBLE THAT SOME
MIXING OF DRY AIR AHEAD OF THE FEATURE COULD START AFFECTING THE
EAST COAST IN THE NEXT FEW HOURS. AREAS TO THE INTERIOR STILL HAVE A
70 PERCENT CHANCE OF SHOWERS AND STORMS FOR THIS AFTERNOON AND
EVENING. A DECK OF MID LEVEL CLOUDS OVER PARTS OF MIAMI-DADE CAN
SLOW DOWN CONVECTION IN THE SHORT TERM. ANOTHER VARIABLE
COMPLICATING THE FORECAST FOR THIS EVENING FOR THE SOUTHEAST COAST
IS THE PRESENCE OF SAHARAN DUST WELL DETECTED BY LIDAR AND THE NAVY
AND GFS AEROSOL MODELS. THE DRY AIR ABOVE THE SURFACE MIXED WITH
THE DUST COULD DIMINISH THE WIDESPREAD CONVECTION BUT STILL ALLOW FOR ONE OR
TWO STRONG STORMS.
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 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 AND ABOVE 48 PERCENT FOR THE
LATER PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 76 88 78 / 20 10 30 30
FORT LAUDERDALE 88 79 89 79 / 30 20 30 40
MIAMI 89 78 89 78 / 30 20 30 40
NAPLES 88 73 92 74 / 50 20 40 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
331 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.AVIATION...
ISSUED 1146 PM CDT SUN JUL 14 2013
VFR CONDITIONS ARE EXPECTED AT ALL SITES NEXT 24HRS. SKIES SHOULD
BE CLEAR OVERNIGHT AND EARLY TOMORROW MORNING. LOW LEVEL MOISTURE
HAS INCREASED IN THE AREA SO LIGHT FOG A POSSIBILITY AGAIN IN THE
MORNING. SO WILL HAVE JUST TEMPO GROUP AT ALL SITES FOR 3-4HRS.
THEN BELIEVE CU WILL AGAIN BE POSSIBLE TOMORROW INTO TOMORROW
AFTERNOON. ISOLATED SHOWERS WILL BE POSSIBLE LATE TOMORROW
AFTERNOON...BUT COVERAGE DOES NOT WARRANT MENTION IN TAFS AT THIS
TIME. CU COULD BECOME MORE BROKEN AS IT WAS LATE THIS AFTERNOON
AND EARLY EVENING BEFORE CLEARING OUT AROUND 01-02Z. SO HAVE ADDED
A TEMPO GROUP FOR BROKEN CIGS AROUND 5KFT AND THEN BECOMING CLEAR
AROUND 02Z. WINDS WILL BE EAST TO SOUTHEAST THROUGH THE PERIOD
WITH SPEEDS LIGHT OVERNIGHT AND AGAIN TOMORROW EVENING.
AUTEN
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1119 PM MDT SUN JUL 14 2013
.SHORT TERM...(THIS AFTERNOON THROUGH TONIGHT)
ISSUED AT 125 PM MDT SUN JUL 14 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOWS 579DM CLOSED LOW CENTERED
OVER NORTHEAST OKLAHOMA WITH STRONG PV HEIGHT ANOMALY IN PLACE OVER
SOUTHEAST KS. A 599DM RIDGE IS IN PLACE OVER THE NORTHEAST US WITH
AXIS EXTENDING NORTH OF CLOSED LOW INTO THE UPPER MISSISSIPPI VALLEY.
WITH GOOD MOISTURE/INSTABILITY IN PLACE AND SEVERAL WEAK CONVERGENT
AREAS WE ARE ALREADY SEEING THUNDERSTORMS DEVELOPING ALONG SEVERAL
WEAK CONVERGENT AREAS IN OUR CWA. AS LARGE SCALE FORCING INCREASES
AND THE MAIN MOISTURE PLUME MOVES OVER OUR CWA I EXPECT THUNDERSTORM
COVERAGE TO INCREASE. WHAT COULD BE DESCRIBED AS A COLD FRONT WILL
MOVE INTO THE CWA FROM THE SOUTHEAST THIS AFTERNOON AHEAD OF COLD
POOL ASSOCIATED WITH STRONG UPPER LOW. THUNDERSTORMS WILL INCREASE
IN COVERAGE AS THIS BOUNDARY MOVES NORTHWEST WITH BEST FORCING
CURRENTLY ADVERTISED IN THE 21-00Z TIME FRAME ALONG THE KS/CO BORDER
WHERE MOST GUIDANCE IS SHOWING VERY HIGH QPF VALUES. LATEST GFS IS A
LITTLE FURTHER EAST...HOWEVER SHORT RANGE GUIDANCE (RUC/HRRR)
CONTINUE TO SUPPORT THE NAM SOLUTION FURTHER WEST ALONG COLORADO
STATE LINE.
A VERY MOIST AIR MASS IS IN PLACE OVER THE CWA WITH LATEST RAP
ANALYSIS INDICATING PWAT VALUES IN EXCESS OF 1.5 INCHES AND AS HIGH
AS 1.8 INCHES IN NORTHEAST PARTS OF THE CWA. WHILE NOT UNHEARD OF
THIS IS ANOMALOUSLY HIGH FOR THIS TIME OF YEAR. SB/ML CAPE VALUES
HAVE INCREASED TO NEAR 2000 J/KG ACROSS THE NORTHEAST CWA AND THE
MAIN INSTABILITY AXIS SHOULD CONTINUE TO SPREAD SOUTH AND WEST THIS
AFTERNOON. SHEAR PROFILES ARE VERY WEAK...SO ANY SEVERE THREAT SHOULD
BE TIED TO WIND/HAIL ASSOCIATED WITH PULSE TYPE THUNDERSTORMS. STORM
MOTION WILL GENERALLY BE IN THE 5-15KT RANGE ACROSS THE AREA AND
THERE WILL BE THE POTENTIAL FOR BACK BUILDING AND SLOW PROPAGATION
ALONG THE BOUNDARY OVER OUR WESTERN CWA. WITH HIGH PRECIP RATES AND
SLOW MOVING (POSSIBLY TRAINING) THUNDERSTORM WE COULD SEE AN
ELEVATED THREAT FOR FLASH FLOODING. DESPITE OVERALL SHOWER AND
THUNDERSTORM COVERAGE LIKELY HIGH I AM NOT CONFIDENT THE FLASH FLOOD
THREAT WILL BE WIDESPREAD ENOUGH TO ISSUE A WATCH AT THIS TIME.
ACTIVITY SHOULD COME TO AN END QUICKLY FROM THE EAST TO THE WEST
THIS EVENING AS STRONG SUBSIDENCE BUILDS IN FROM THE NORTHEAST
ASSOCIATED WITH RIDGE BUILDING EAST BEHIND TROUGH. WITH LINGERING
CONVERGENCE ACROSS EASTERN COLORADO AND MOIST UPSLOPE WE COULD SEE A
FEW LINGERING SHOWERS/THUNDERSTORMS THROUGH 12Z WITH PATCHY FOG
POSSIBLY DEVELOPING IN THE 09Z-12Z TIME FRAME.
.LONG TERM...(MONDAY THROUGH SUNDAY)
ISSUED AT 158 PM MDT SUN JUL 14 2013
MONDAY MORNING MAY START OUT WITH SOME FOG OVER THE SOUTHERN AND
WESTERN PARTS OF THE AREA. ANY FOG THAT DEVELOPS SHOULD CLEAR OUT
BY MID MORNING. THE UPPER LEVEL LOW PRESSURE THAT BROUGHT RAINFALL
TO THE TRI-STATE AREA WILL CONTINUE TO MOVE SOUTH. LATE MONDAY
AFTERNOON INTO EARLY MONDAY EVENING THERE WILL BE A BAND OF MID
LEVEL LIFT THAT WILL MOVE ACROSS THE FAR SOUTHERN PART OF THE AREA.
THERE WILL BE AMBLE MOISTURE TO WORK...BUT THE LIMITING FACTOR WILL
BE THE STRENGTHEN OF THE LIFT AND THE SMALL AMOUNT OF INSTABILITY
AVAILABLE. AT THIS TIME THERE APPEARS TO BE ENOUGH LIFT AND
INSTABILITY THAT AN ISOLATED STORM CANNOT BE RULED OUT...SO WILL
KEEP THE SLIGHT CHANCES IN THE FORECAST BUT CONFINE THEM TO THE LATE
AFTERNOON AND EARLY EVENING.
TUESDAY AN UPPER LEVEL RIDGE BEGINS BUILDING OVER THE AREA.
SOUNDINGS OVER EAST CENTRAL COLORADO SHOW SOME INSTABILITY TO WORK
WITH AND LITTLE CIHN DURING THE AFTERNOON...BUT WITH NO SURFACE
CONVERGENCE OR UPPER LEVEL LIFT TO TRIGGER STORMS WILL KEEP THE DAY
DRY.
WEDNESDAY THROUGH SUNDAY AN UPPER LEVEL RIDGE WILL MOVE OVER THE
PLAINS THEN BECOME ESTABLISHED OVER THE ROCKIES. TOWARD THE END OF
THE WEEK THE UPPER LEVEL FLOW WILL STRENGTHEN AND BECOME NORTHWEST.
MODELS HAVE FLATTENED OUT THE SHORT WAVE TROUGH THAT WOULD MOVE OVER
THE AREA DURING THE WEEKEND. THE STRENGTH OF THE COLD FRONT HAS
ALSO DECREASED...WITH MODELS WASHING IT OUT ON SATURDAY OVER THE
AREA. HOWEVER MODELS STILL HAVE A SURFACE TROUGH/WEAK COLD FRONT
OVER THE AREA FOR THE WEEKEND. WITH NORTHWEST UPPER LEVEL FLOW OVER
THE AREA THERE IS STILL A POSSIBILITY FOR STORMS TO
DEVELOP...ALTHOUGH NOT AS GOOD AS PREVIOUSLY THOUGHT.
HIGH TEMPERATURES FOR THE PERIOD WILL GRADUALLY WARM TO ABOVE NORMAL
BY THE END OF THE WEEK AS THE UPPER LEVEL RIDGE BUILDS OVER THE
AREA. WITH LITTLE CHANGE IN THE AIR MASS BY THE END OF THE
WEEK...HIGHS WILL LARGELY REMAIN UNCHANGED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1113 PM MDT SUN JUL 14 2013
ISOLATED SHOWERS OVERNIGHT WILL NOT IMPACT EITHER KGLD OR KMCK.
MODELS HAVE SOMEWHAT BACKED OFF ON STRATUS/FOG POSSIBILITIES. LOW
LEVELS REMAIN QUITE MOIST AND FORECAST LOWS ARE SEVERAL DEGREES
BELOW CURRENT DEW POINTS. HOWEVER MID AND HIGH LEVEL CLOUDS ARE
PERSISTING WHICH WILL LIMIT RADIATIONAL COOLING. STILL THINK THERE
COULD BE AN HOUR OR TWO OF MVFR CIGS AND/OR VISBY RESTRICTIONS
RIGHT AROUND SUNRISE...BEFORE LIFTING LATER IN THE MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...024
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 AM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 130 AM EDT MON JUL 15 2013
HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION. SOME PATCHY FOG
HAS DEVELOPED IN THE KIWD AREA AS TEMPERATURES HAVE FALLEN OFF
FASTER THERE WITH THE LOSS OF DAYTIME HEATING. AS TEMPERATURES
CONTINUE TO FALL UNDER CLEAR TO PARTLY CLOUDY SKIES PATCHY FOG WILL
EVENTUALLY IMPACT ALL THREE TAF SITES. EXPECT MVFR CONDITIONS WITH
THE FOG...BUT KIWD MAY SEE A FEW IFR VISIBILITIES DURING THE
OVERNIGHT HOURS. ONCE THE SUN RISES...THE FOG WILL QUICKLY BURN OFF
LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE FORECAST. THERE IS A
VERY SLIGHT POSSIBILITY OF A SHOWER OR THUNDERSTORM AT KCMX AROUND
0Z AS A DISTURBANCE RIDES OVER THE RIDGE JUST TO THE NORTH...BUT
PROBABILITIES ARE SO LOW HAVE LEFT OUT OF THE FORECAST AT THIS TIME.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...RJT
MARINE...KC
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1138 PM MDT SUN JUL 14 2013
.UPDATE...
STRATUS DECK HAS MOVED INTO FAR EASTERN ZONES LATE THIS EVENING
BRINGING OVERCAST CONDITIONS TO FALLON AND CARTER COUNTIES. LOOKS
LIKE ADDITIONAL MOVEMENT OF THIS DECK TO THE WEST WILL OCCUR
OVERNIGHT...ENDING UP ALONG A MILES CITY TO ASHLAND LINE BY
SUNRISE. KEPT OUT OF SHERIDAN FOR NOW BUT CAN NOT RULE OUT CLOUD
COVER PUSHING UP ALONG THE BIG HORN FOOTHILLS AND MAY NEED TO
ADJUST FURTHER WITH THE MORNING FORECAST PACKAGE. ALSO ADJUSTED
POPS FOR TONIGHT INTO TOMORROW MORNING. WEAK VORTICITY IS
PRODUCING A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OVER PARK AND
SWEET GRASS COUNTIES. THIS ACTIVITY LOOKS TO MOVE NORTH-NORTHEAST
OVER THE NEXT FEW HOURS. MODELS DON`T LOOKS IMPRESSIVE ENOUGH TO
KEEP POPS FURTHER EAST OF THIS ACTIVITY OUTSIDE OF THE HIGHER BIG
HORNS...SO REMOVED POP MENTION ELSEWHERE THROUGH MONDAY MORNING.
CHAMBERS
&&
.SHORT TERM...VALID FOR MON AND TUE...
ACTIVE WEATHER WILL CONTINUE TONIGHT THROUGH TUE NIGHT. A BAND OF
CONVECTION CONTINUED MOVING THROUGH SE MT THIS AFTERNOON PER RADAR
IMAGERY. THE BAND WAS BEING FUELED BY JET DIVERGENCE. OTHER
CONVECTION WAS MOVING INTO THE SW PART OF THE AREA AHEAD OF A
SHORTWAVE MOVING INTO W MT AND WEAK WAVES SW OF THE AREA. A WARM
FRONT WILL MOVE N THROUGH THE REGION TONIGHT ACCOMPANIED BY
ISENTROPIC LIFT. THE HRRR HAS BEEN GENERATING CONVECTION OVER THE
S CENTRAL PART OF THE AREA FOR THE LAST FEW RUNS DURING THE
EVENING. THE RAP SHOWED 1000 J/KG OF SURFACE CAPE IN THIS AREA AND
THE WRF HAD DECENT BULK SHEAR...SO STORMS IN THIS AREA COULD BE
STRONG. A LOW-LEVEL JET WILL HELP SUSTAIN CONVECTION IN THE E
THROUGH THE NIGHT. THUS WENT WITH CHANCE POPS S TAPERING TO SLIGHT
CHANCE N DURING THE EVENING...AND SLIGHT CHANCE E OVERNIGHT.
PRECIPITABLE WATERS AROUND AN INCH WILL SUPPORT HEAVY RAIN WITH
THE THUNDERSTORMS.
MON WILL BE A PREFRONTAL DAY. SHORTWAVES WILL CONTINUE MOVING
THROUGH THE SW FLOW ALOFT. INVERTED-V SOUNDINGS WERE FORECAST FOR
THE CENTRAL AND W ZONES. KMLS WAS CAPPED ON BUFKIT. CAPES AT KBHK
WERE 1000-1500 J/KG...BUT SOUNDINGS DID NOT SHOW MUCH IN THE WAY
OF LIFT. HAD CHANCE POPS SE IN THE MORNING NEAR SHORTWAVE ENERGY
THEN ISOLATED TO SCATTERED POPS IN THE AFTERNOON AND EVENING DUE
TO ADDITIONAL SHORTWAVES AND THE APPROACH OF THE FRONT. GOOD
MIXING WILL PROMOTE HIGH TEMPERATURES IN THE 90S IN MANY AREAS.
KEPT POPS THROUGH THE NIGHT DUE TO THE COLD FRONT.
THE FRONT WILL SETTLE OVER THE REGION ON TUE AND THE FLOW WILL
TURN E. HAD MAINLY ISOLATED POPS THROUGH THE DAY. STRONG THETA-E
RIDGE WILL HELP CONTINUE CHANCES FOR THUNDERSTORMS TUE NIGHT. TUE
WILL BE COOLER WITH READINGS IN THE 80S BUT A THERMAL RIDGE WILL
KEEP THE E WARMER WITH TEMPERATURES AROUND 90. ARTHUR
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
THE THEME IN THE EXTENDED FORECAST REMAINS SUMMER TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS EACH DAY. BROAD SUMMER RIDGING
WILL FINALLY BE ESTABLISHED ACROSS MOST OF THE CONUS WITH THE
FORECAST AREA REMAINING ON THE NORTHERN EXTENT OF THE RIDGE WITH
THE JET STREAM NEARBY TO THE NORTH.
THIS SETUP WILL ALLOW INCREASING MID-LEVEL MOISTURE ACROSS THE
FORECAST AREA FROM THE MONSOONAL FLOW OUT OF THE SOUTH.
FURTHERMORE...LOW-LEVEL MOISTURE WILL BE ON THE INCREASE THANKS TO
GULF MOISTURE BEING TRANSPORTED UP THE GREAT PLAINS AND INTO THE
FORECAST AREA FROM THE EAST AND NORTHEAST. THIS WILL KEEP PW
VALUES RUNNING BETWEEN 1 AND 1.5 INCHES ACROSS THE FORECAST AREA
WEDNESDAY THROUGH FRIDAY. THESE WILL BE THE BEST DAYS IN THE
EXTENDED FORECAST FOR THUNDERSTORM ACTIVITY. DEEP LAYER SHEER
(0-6KM) SHOULD BE WEAK ON WEDNESDAY AS THE JET STREAM REMAINS
MOSTLY NORTH OF THE FORECAST AREA...THUS EXPECT STORMS TO BE HEAVY
RAINERS BUT THE SEVERE POTENTIAL SHOULD BE VERY LIMITED. DEEP
LAYER SHEER SHOULD INCREASE TO AROUND 40 KTS FOR THURSDAY AND
FRIDAY AS THE JET SAGS FARTHER SOUTH. THIS WILL BE COUPLED WITH
COOLER 700 MB TEMPERATURES. THUS EXPECT THUNDERSTORMS ON THURSDAY
AND FRIDAY COULD BE ON THE STRONG SIDE WITH SOME ISOLATED SEVERE
POTENTIAL.
STRONGER ZONAL TO NORTHWESTERLY FLOW ESTABLISHES OVER THE FORECAST
AREA BY THE WEEKEND. THIS HELPS TO KEEP MONSOONAL MOISTURE LOCKED
TO THE SOUTH OF THE FORECAST AREA WHILE THE LOW-LEVEL MOISTURE
BECOMES SHIFTED TO THE EAST. THIS SHOULD MINIMIZED OUR CHANCES OF
PRECIPITATION THIS WEEKEND.
TEMPERATURES WILL REMAIN JUST ABOVE SEASONAL NORMALS IN THE UPPER
80S AND LOW 90S THROUGH THE EXTENDED FORECAST.
CHURCH
&&
.AVIATION...
A FEW SHOWERS AND AN ISOLATED THUNDERSTORM OR TWO ARE POSSIBLE
OVER FAR WESTERN ROUTES FOR THE NEXT FEW HOURS. OTHERWISE...VFR
CONDITIONS ARE EXPECTED THROUGH MID DAY MONDAY. STC
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 061/095 064/083 062/090 066/092 065/093 065/094 065/094
12/T 22/T 32/T 32/T 33/T 31/B 11/B
LVM 052/091 054/085 056/091 055/092 056/093 052/095 052/095
23/T 33/T 33/T 33/T 33/T 32/T 21/B
HDN 061/096 062/087 058/092 061/093 063/093 061/095 061/096
12/T 22/T 32/T 32/T 32/T 21/B 11/B
MLS 065/095 067/089 064/093 068/093 066/093 067/094 066/094
12/T 22/T 22/T 22/T 22/T 21/B 11/U
4BQ 062/093 062/092 061/093 063/091 065/090 061/092 060/093
12/T 22/T 21/U 12/T 22/T 21/B 11/U
BHK 060/087 062/088 059/091 064/090 064/088 062/089 061/090
12/T 22/T 21/B 22/T 22/T 22/T 21/U
SHR 058/091 058/089 058/092 058/091 058/090 057/092 057/094
12/T 22/T 22/T 22/T 33/T 31/B 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
335 AM CDT MON JUL 15 2013
.DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. GENERALLY CLEAR
SKIES ARE EXPECTED OVERNIGHT WITH LIGHT SOUTHEAST WINDS. WE EXPECT
SOME CUMULUS TO DEVELOP THROUGH THE LATE MORNING AND INTO THE
AFTERNOON AT ALL 3 SITES...BUT ESPECIALLY OMA/LNK. AN ISOLD SHOWER
APPEARS POSSIBLE AT OMA...BUT TIMING AND VERY ISOLD NATURE
PRECLUDES MENTION ATTM.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
325 AM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1225 AM CDT MON JUL 15 2013
.AVIATION...
A LINE OF THUNDERSTORMS AND RAINSHOWERS WILL CONTINUE TO MOVE SLOWLY
WEST OVER THE WESTERN NEBRASKA SANDHILLS THROUGH THE EARLY MORNING
HOURS. STRATUS WITH IFR CEILINGS WILL CONTINUE OVER THE KVTN TAF
SITE THROUGH 15/12Z. MARGINAL MVFR CEILINGS ARE POSSIBLE OVER
SOUTHERN NEBRASKA BUT THE GENERAL TREND HAS BEEN FOR VFR CEILINGS
AND HAVE CONTINUED THIS TREND OVER NIGHT. CEILINGS WILL LIFT THROUGH
MID MORNING OVER NORTHERN NEBRASKA WITH SOUTHERLY WINDS INCREASING
TO 10 TO 20 MPH THROUGH THE DAY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...POWER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
135 AM EDT MON JUL 15 2013
.SYNOPSIS...
A LARGE MID LEVEL RIDGE OVER THE OHIO VALLEY WILL GROW IN SIZE
AND DRIFT SOUTH THROUGH THE MIDDLE OF THE WEEK. THE RIDGE WILL
WEAKEN LATE IN THE WEEK WHILE BERMUDA HIGH PRESSURE BUILDS BACK FROM
THE EAST AND THE PIEDMONT TROUGH STRENGTHENS. NEXT WEEKEND...A COLD
FRONT WILL APPROACH FROM THE NORTHWEST...POTENTIALLY BRINGING AN
INCREASED CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 11 PM SUNDAY...HAVE ADJUSTED POPS TO A LOW CHANCE FOR
MAINLY THE PRE-DAWN HRS OF MONDAY TO ACCOUNT FOR ANY ONSHORE
MOVEMENT OF NOCTURNAL SHRA ACTIVITY FROM OFF THE ADJ ATLANTIC.
LATEST ADJACENT NWS 88D RADARS DEPICT THE INCREASING WIDELY
SCATTERED SHRA DEVELOPMENT OVER THE ADJACENT ATLANTIC WATERS.
NAMBUFR SOUNDINGS ACROSS THE COASTAL FA...INDICATE AN EASTERLY
FLOW THRUOUT THE ATM COLUMN. AS A RESULT...THIS DEEP ONSHORE FLOW
WILL PERIODICALLY PUSH ANY ATLANTIC PCPN ACTIVITY ONSHORE. A
MODEST CAP WILL EXIST IN THE 800-750 MB RANGE VIA PROGGED NAMBUFR
HOURLY SOUNDINGS...THUS PUTTING A LID ON ANY FURTHER VERTICAL
DEVELOPMENT OF THE OVERNIGHTS PCPN. THEREFORE...DO NOT EXPECT
MUCH IF ANY THUNDERSTORM ACTIVITY TO ACCOMPANY THIS PCPN. THE
LATEST MIN TEMP FORECAST OF 70 TO 75 DEGREES STILL LOOKING
AOK...WITH 74 TO 78 DEGREE READINGS RESERVED FOR ALONG THE
IMMEDIATE COAST.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...SURFACE AND MID LEVEL RIDGING OVER THE OH VALLEY
WILL GRADUALLY EXPAND SOUTH DURING THE PERIOD. EAST FLOW AROUND THE
SOUTHERN EDGE OF THE SURFACE HIGH WILL HELP KEEP TEMPERATURES A
LITTLE COOLER THAN WHAT IS TYPICAL FOR MID JULY...ESPECIALLY NEAR
THE COAST. EASTERLY FLOW WILL ALSO MAINTAIN THE SUPPLY OF LOW LEVEL
MOISTURE. CONVERGENCE ALONG THE EASTERLY WIND ENHANCED SEA BREEZE
MAY TRIGGER SOME WEAK CONVECTION ACROSS INLAND AREAS MON AFTERNOON.
ALTHOUGH THERE WILL BE SOME MID LEVEL SUBSIDENCE ON THE PERIPHERY OF
THE 5H RIDGE MON IT WILL BE ON THE WEAK SIDE AND PROBABLY NOT STRONG
ENOUGH TO SUPPRESS ALL DEEPER CONVECTION. SOUTHWARD EXPANSION OF 5H
RIDGE ON TUE INCREASES SUBSIDENCE WHICH SHOULD KEEP THE REGION DRY.
HAVE TWEAKED POP FORECAST FOR MON WITH VALUES RANGING FROM SLIGHT
CHANCE TO LOW CHANCE ACROSS INLAND SC...WHERE SUBSIDENCE SHOULD BE
WEAKEST. MAINTAIN THE DRY FORECAST BUT HAVE NON ZERO POP TUE/TUE
NIGHT.
EASTERLY FLOW ON MON WILL KEEP TEMPERATURES ACROSS MUCH OF THE
REGION BELOW CLIMO AND MOST AREAS WILL STRUGGLE TO REACH 90. SUBTLE
WIND SHIFT...TO SOUTHEAST...ON TUE WILL KEEP COASTAL LOCATIONS COOL
BUT ALLOW INLAND AREAS TO WARM UP. LOW 90S ARE EXPECTED WITH
POTENTIAL FOR ISOLATED MID 90S. LOWS WILL RUN NEAR TO SLIGHTLY ABOVE
CLIMO. TUE NIGHT WILL BE WARMER OF THE TWO NIGHTS AS BERMUDA HIGH
STARTS TO REASSERT ITSELF AND SOUTHERLY FLOW DEVELOPS. ADDITIONALLY
GUIDANCE IS SHOWING A WEAK SHORTWAVE DROPPING SOUTH ALONG THE EAST
COAST TUE NIGHT. NOT SOLD ON STRENGTH...TIMING...AND LOCATION OF
THIS FEATURE BUT IT COULD PRODUCE A MID LEVEL CLOUD DECK TUE NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...STRONG RIDGE OVER THE OHIO VALLEY SINKS SOUTH
AND WEAKENS BY THE WEEKEND AS A MID TO UPPER TROUGH DIGS DOWN FROM
CANADA AND RIDES THROUGH THE NORTHEAST INTO THE MID ATLANTIC STATES
THROUGH THE WEEKEND. THE RIDGE ALOFT WILL BE ELONGATED NORTH OF OUR
LOCAL AREA AS IT REACHES UP THROUGH THE LOW AND MID TO UPPER LEVELS
OF THE ATMOSPHERE. THEREFORE THERE WILL BE A DEEP EAST TO NORTHEAST
FLOW INITIALLY THROUGH WED. OVERALL EXPECT A FAIRLY DRY ATMOSPHERE
WITH MID TO UPPER RIDGE REACHING DOWN INTO AREA LEADING TO LITTLE TO
NO UPPER LEVEL DYNAMICS TO SUPPORT MUCH IN THE WAY OF SHWRS/TSTM
ACTIVITY BUT MODELS DO SHOW A MINOR PERTURBATION MAKING ITS WAY
AROUND THE BASE OF THE H5 RIDGE INTO THE CAROLINAS ON WED. THESE
FEATURES ARE TOUGH TO TIME BUT IT MAY LEAD TO A SLIGHT ENHANCEMENT
OF CLOUDS AND/OR CONVECTIVE DEVELOPMENT ON WED...MAINLY
INLAND...ESPECIALLY AS PIEDMONT TROUGH BECOMES MORE PRONOUNCED
THROUGH MID TO LATE WEEK. GFS SHOWING PCP WATER VALUES REACHING UP
OVER 2 INCHES INLAND WED AFTN.
BY THURSDAY THE LOW LEVEL FLOW BECOMES MORE SOUTHWESTERLY AS BERMUDA
RIDGE AND PIEDMONT TROUGH BECOME DOMINANT FEATURES. A FAIR AMOUNT OF
SUBSIDENCE AND DRY AIR WILL CONTINUE THROUGH THURS AND FRI AS MID TO
UPPER RIDGE MOVES CLOSER OVERHEAD. AT THE LOW LEVELS MODELS SHOW
DRIER AIR UPSTREAM BRINGING PCP WATER VALUES DOWN NEAR 1.5 INCHES
THURS INTO FRI. BY FRI NIGHT INTO SATURDAY THE SOUTHWEST FLOW
CONTINUES WITH A SLIGHT INCREASE IN MOISTURE BUT OVERALL A MODEST
AMOUNT FOR THIS TIME OF YEAR.
BASICALLY EXPECT MORE ISOLATED AND LOCALIZED SHOWER ACTIVITY THROUGH
MOST OF THE PERIOD...WITH MAIN FOCUS ALONG SEA BREEZE CONVERGENT
BOUNDARY AND FURTHER INLAND ALONG PIEDMONT TROUGH. BY SUNDAY THE MID
TO UPPER TROUGH MAY PUSH A COLD FRONT INTO THE CAROLINAS WITH PLENTY
OF MOISTURE AND GREATER INSTABILITY AHEAD OF THE FRONT ACROSS THE
CAROLINAS.
TEMPERATURES CLOSE TO OR A FEW DEGREES ABOVE CLIMO THROUGH AT LEAST
THE FIRST HALF OF THE PERIOD AS RIDGE KEEPS HIGHER H5 HEIGHTS AND
LOW LEVEL THICKNESSES ACROSS THE AREA. EXPECT READINGS 90 TO 95 MOST
PLACES DURING THE DAY AND LOWER 70S AT NIGHT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...NO SIGNIFICANT CHANGE TO THE CURRENT TAFS. ISOLATED
SHOWERS WILL CONTINUE THIS MORNING...BUT THE CHANCE OF ANY TERMINAL
BEING AFFECTED IS LOW.
THERE IS MODERATE CONFIDENCE FOR IFR CIGS EARLY THIS MORNING AT
KFLO/KLBT WITH MVFR CIGS AT THE COASTAL TERMINALS. CIGS COULD DROP
INTO THE LIFR LEVEL AT TIMES IN THE PRE-DAWN HOURS AT KLBT/KFLO. FOG
POTENTIAL WILL BE HINDERED BY BOUNDARY LAYER WINDS AROUND 16 KT...
BUT ABUNDANT LOW LEVEL MOISTURE SHOULD ALLOW VSBYS TO POTENTIALLY
DROP TO AT LEAST MVFR LEVELS AT KFLO/KLBT. VSBYS SHOULD REMAIN VFR
AT THE COASTAL TERMINALS. AFTER SUNRISE VFR EXPECTED AT THE COASTAL
TERMINALS. AT KFLO/KLBT ANY SUB-VFR VSBYS INCREASE TO VFR FAIRLY
RAPIDLY...BUT CIGS SLOWLY RISE TO MVFR BY 14Z THEN TO VFR 16Z. WINDS
WILL BE E 10-15 KT...HIGHEST AT THE SOUTHERN COASTAL TERMINALS. ANY
SHOWER DEVELOPMENT SHOULD BE ISOLATED AT THE COASTAL TERMINALS
DURING THE MORNING. THIS ACTIVITY WILL MOVE WNW TOWARDS THE KFLO
TERMINAL BY MID TO LATE MORNING.
EXTENDED OUTLOOK...A CHANCE OF EARLY MORNING IFR CIGS AND TEMPO MVFR
MORNING/AFTERNOON CIGS THROUGH THE PERIOD. ISOLATED SHOWERS AND
THUNDERSTORMS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1130 PM SUNDAY...SCEC FOR ALL WATERS EXCEPT AMZ254...VALID
THROUGH MONDAY MID-MORNING. SFC PRESSURE PATTERN AND TIGHTENED
GRADIENT WILL YIELD ENE TO ESE WIND DIRECTIONS AT 10 TO 20
KT...WITH A FEW GUSTS UP TO 25 KT. THIS WELL SUPPORTED BY THE
LATEST HRRR HOURLY PROGGED SFC WIND DATA AND THE CURRENT NAM AND
GFS SFC FIELDS. THE LATTER 2 MODELS INDICATE A WESTWARD MOVING
INVERTED SFC TROF TO PROGRESS ACROSS THE ATL WATERS FROM WELL OFF
THE SE U.S. COAST...TO THE ATL WATERS JUST OFFSHORE FROM THE GA-FL
COAST BY DAYBREAK MONDAY. WAVEWATCH3 INDICATES A SWATH OR BUBBLE
OF HIER SEAS...AN EASTERLY SWELL EXHIBITING 8 SECOND
PERIODS...ASSOCIATED WITH THIS TROF THAT PARTIALLY PUSHES ACROSS
THE ILM AREA WATERS. AS A RESULT...SIGNIFICANT SEAS WILL REMAIN OR
HOLD IN THE 3 TO 5 FOOT RANGE OVERNIGHT...AND TRANSITION FROM THE
INITIAL DOMINANT WIND DRIVEN WAVE EXHIBITING AVERAGE PERIODS IN
THE 5.0 TO 6.0 SECOND RANGE...TO AN INCREASING AND MORE DOMINANT E
TO ESE SWELL AT 7 TO 8 SECOND PERIODS. WIDELY SCATTERED NOCTURNAL
SHRA TO PUSH ACROSS THE AREA WATERS...WITH THE BEST COVERAGE TO
OCCUR FROM CAPE FEAR SOUTHWARD.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...GRADIENT OVER THE WATERS WILL WEAKEN DURING THE
PERIOD AS SURFACE HIGH NORTHWEST OF THE WATERS SETTLES SOUTH. FLOW
WILL REMAIN EAST TO NORTHEAST INTO TUE BEFORE BERMUDA HIGH STARTS TO
EXTEND WEST...SETTING UP RETURN FLOW. NORTHEAST FLOW STARTS OUT ON
THE HIGH END OF THE 10 TO 15 KT RANGE MON MORNING BUT SHOULD BE 10
KT OR LESS BY MID AFTERNOON. RELAXED GRADIENT KEEPS SOUTHERLY FLOW
10 KT OR LESS THROUGH TUE NIGHT. SEAS WILL SLOWLY SUBSIDE ON
MON...FALLING FROM 3 TO 5 FT AT THE START OF THE PERIOD TO 2 TO 4 FT
MON NIGHT. SEAS CONTINUE TO DECREASE TUE AND TUE NIGHT IN THE
PRESENCE OF LIGHT WINDS...FALLING TO 2 FT BY THE END OF THE PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WHILE RIDGE SHIFTS FURTHER SOUTH ALOFT
CREATING A MORE EASTERLY FLOW ABOVE THE SURFACE...THE FLOW AT THE
SURFACE WILL BACK FROM WESTERLY ON WED AS HIGH PRESSURE CENTERED
SOUTH OF AREA WEAKENS TO MORE SOUTHWEST TO SOUTHERLY AS BERMUDA
HIGH TAKES CONTROL THURS INTO NEXT WEEKEND. OVERALL FAIRLY TYPICAL
SUMMERTIME PATTERN SETS UP THURS INTO THE WEEKEND WITH HIGH
PRESSURE TO THE EAST AND PIEDMONT TROUGH OVER THE INLAND CAROLINAS
TO PRODUCE PERSISTENT S-SW FLOW. INITIALLY A LIGHTER OFF SHORE
FLOW WILL ALLOW SEAS TO SUBSIDE TO LESS THAN 3 FT MOST WATERS. THE
PERSISTENT AND INCREASING S-SW FLOW UP TO 15 KTS OR SO THAT SETS
UP THURS INTO THE WEEKEND WILL PUSH SEAS UP 3 TO 4 FT BY LATE FRI.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...III
NEAR TERM...DCH
SHORT TERM...III
LONG TERM...RGZ
AVIATION...MRR/RJD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1147 PM CDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 1144 PM CDT SUN JUL 14 2013
NO ADDITIONAL CHANGES OVERNIGHT.
UPDATE ISSUED AT 1000 PM CDT SUN JUL 14 2013
SHOWER ACTIVITY IN FAR SOUTHEASTERN FCST AREA CONTINUES TO WEAKEN
IN COVERAGE AND MOSTLY AREAS OF LIGHT RAIN/DRIZZLE. KEPT SCT
SHOWERS IN THRU THE NIGHT. COORD WITH WFO BIS AND REMOVED ANY POPS
FOR AREAS NORTH AND WEST OF DEVILS LAKE. SHOWERS WEST AND NORTH OF
MINOT HEADED NORTHEAST AND LATEST 00Z NAM/RUC/HRRR ALL HAVE DRY IN
DVL BASIN TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 306 PM CDT SUN JUL 14 2013
VERY INTERESTING SYNOPTIC PATTERN WITH WELL ADVERTISED
RETROGRESSION OF UPPER LOW ACROSS MIDWEST. AS THIS SYSTEM MOVES
WEST-SOUTHWEST A SHORT WAVE OVER BRITISH COLUMBIA WILL MOVE EAST-
NORTHEAST. ANOTHER SHORTWAVE OVER NORTH CENTRAL MONTANA IS
GENERATING TSRA OVER EASTERN MONTANA AND WESTERN ND. THE LOW TO OUR
SOUTH HAS HELPED PRODUCE MULTIPLE FEEDS OF DEEP LAYERED MOISTURE
INTO THE CONVERGENT ZONE ALONG A BDE...BJI TO BWP LINE. THIS HAS
KEPT CONVECTION GOING ACROSS PARTS OF THE CWFA TODAY.
TONIGHT...DRIER SURFACE AIR AND UPPER CONVERGENCE IS HELPING TO
STABILIZE THE LOWER LAYERS AND SHRINK THE AREA OF CONVECTION. HAVE
FOLLOWED THE THE HRRR IN THE OVERNIGHT WHICH DECREASES POPS OVER
THE SOUTH WHILE INCREASING THEM IN THE DEVILS LAKE BASIN AFTER
06Z. EXPECT ONLY ISOLD TO WDLY SCATTERED SHRA/TSRA TONIGHT.
MONDAY...BOUNDARY BEGINS TO LIFT NORTH DURING THE MORNING. THERE
COULD BE LINGERING LIFT FROM THE MONTANA WAVE TO INTERACT WITH THE
NORTHWARD MOVING BOUNDARY TO MAINTAIN / REGENERATE TSRA MONDAY.
INSTABILITY AND LIFT MARGINAL AS FRONT MOVES NORTH...850 JET
FORECAST 20 TO 25 KTS...SHOWALTERS -2 TO -4 AND MU-CAPES AROUND
1500 J/KG SUGGEST LOW RISK SEVERE.
MONDAY NIGHT...BOUNDARY LIFTS NORTH TOWARDS INTERNATIONAL BORDER.
DRIER AIR MOVING IN FROM THE SOUTH...COURTESY OF LOWER PLAINS
CIRCULATION... REDUCES THE CONVECTIVE RISK. HAVE CONFINED POPS
NORTH OF THE U.S. 2 CORRIDOR AFTER 00Z MONDAY.
TUESDAY...BOUNDARY FORECAST TO CLEAR THE CWFA FOR THE MORNING
TUESDAY. ATMOSPHERE REMAINS RELATIVELY STABLE UNTIL LATER IN THE
DAY SO HAVE KEPT THE FORENOON PERIOD PRECIPITATION FREE. SHORTWAVE
MOVING FROM ALBERTA TO NORTHERN MANITOBA BUILDS A WEAK SURFACE
HIGH PUSHING THE FRONT BACK SOUTH. AS BOUNDARY BEGINS TO DROP
ACROSS THE AREA...DAYTIME HEATING AND MARGINAL MOISTURE SHOULD
RESULT IN TSRA LATER TUESDAY AFTERNOON AND EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 306 PM CDT SUN JUL 14 2013
TUESDAY NIGHT AND WEDNESDAY SHOULD SEE A FRONTAL BOUNDARY MOVING
INTO THE NORTHERN CWA AND STALLING OUT AS A LARGE UPPER RIDGE
CONTINUES OVER MUCH OF THE CENTRAL CONUS AND TROUGHING SETTING UP
OVER CANADA. THE FRONT MAY START TO WASH OUT A BIT DURING THE DAY
ON WEDNESDAY...BUT THINK THERE WILL BE ENOUGH CONVERGENCE REMAINING
ALONG IT TO ALLOW THUNDERSTORMS TO CONTINUE TO DEVELOP. CONTINUED TO
KEEP 20-40 POPS TUESDAY NIGHT AND WEDNESDAY NEAR THE CANADIAN BORDER
WHERE THE FRONT SEEMS LIKELY TO SET UP.
THURSDAY...AN UPPER SHORTWAVE WILL BEGIN TO DIG INTO
SASKATCHEWAN...AND THE BOUNDARY SHOULD MOVE SOUTH. THINK WITH THE
FRONT COMING THROUGH AND DECREASING 500MB HEIGHTS THERE WILL BE A
GOOD CHANCE FOR PRECIPITATION SO KEPT PRETTY HIGH POPS GOING. THE
SHORTWAVE WILL DIG DOWN INTO THE CWA ON FRIDAY...WITH PRECIP
STARTING TO TAPER OFF AND TEMPERATURES DROPPING BACK TO NEAR
SEASONAL NORMALS.
FOR NEXT WEEKEND...THE MODELS ARE IN PRETTY GOOD AGREEMENT ON
NORTHWESTERLY FLOW ALOFT SETTING UP...ALTHOUGH DIFFER QUITE A BIT ON
THE TIMING OF VARIOUS WEAK SHORTWAVES COMING THROUGH. THUS...SEE
LITTLE REASON TO DEVIATE MUCH FROM ALLBLEND POPS. TEMPS SHOULD BE
CLOSE TO AVERAGE FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1144 PM CDT SUN JUL 14 2013
ISSUE FOR THIS TAF PERIOD WILL BE CIGS. AREA OF 900-800 MB
MOISTURE WILL REMAIN IN PLACE FROM INL-BDE TO FARGO-FERGUS FALLS
AND INTO SOUTH DAKOTA. WITHIN THIS REGION THERE ARE POCKETS OF IFR
CIGS IN SOME DRIZZLE/LIGHT RAIN AND LIGHT FOG. EXPECT THESE
CONDITIONS TO HOLD THRU 15Z MON...WITH BEST CHC OF IFR VSBY/CIGS
IN HIGHER TERRAIN BJI-PKD-DTL REGION. DO EXPECT MOSTLY VFR CIGS TO
CONTINUE OR SLOWLY SPREAD NORTHWEST THRU MONDAY AS FRONTAL
BOUNDARY LIFTS NORTHEAST. PRECIP CHANCES AT ANY TAF SITE BLO 20
PCT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...RIDDLE
SHORT TERM...EWENS
LONG TERM...JR
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
244 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL DOMINATE THE WEATHER. VFR CONDITIONS WILL
GENERALLY PREVAIL...ALTHOUGH CAN NOT RULE OUT SOME FOG IN MOUNTAIN
VALLEYS EARLY THIS MORNING...AND A COUPLE OF AFTERNOON THUNDERSTORMS
CREATING RESTRICTIONS.
FORECAST CONFIDENCE: HIGH
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...FOG LOCATION AND DENSITY
COULD VARY EARLY THIS MORNING. LOCATION OF THUNDERSTORMS THIS
AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 07/15/13
UTC 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
EDT 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
CRW CONSISTENCY H H H H M M H H L L H H
HTS CONSISTENCY H H H H H H H H H M H H
BKW CONSISTENCY H M M M M M H H H M M H
EKN CONSISTENCY H H M M L L L L L L M H
PKB CONSISTENCY H H H H H H H H L L H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 06Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
427 AM CDT MON JUL 15 2013
.DISCUSSION...
THE UPPER LEVEL LOW IS CURRENTLY LOCATED OVER CENTRAL OKLAHOMA
THIS MORNING AS HAS BEEN FORECASTED THE LAST COUPLE OF DAYS.
RAINFALL HAS BEEN FALLING THIS MORNING MAINLY FROM A BRENHAM TO
HUNTSVILLE TO CROCKETT LINE. CURRENT HRRR MODEL RUNS SHOW THE
PRECIP FIELD ASSOCIATED WITH THE UPPER LOW MOVING OFF TO THE WEST
AS THE DAY PROGESSES BUT ALSO HINTS AT REDEVELOPMENT AS MOISTURE
POOLS INTO SOUTHEAST TEXAS. THE EXTENT OF REDEVELOPMENT WILL BE
DEPENDENT ON THE POSITION OF THE UPPER LEVEL LOW. IF THE LOW IS
FAR ENOUGH WEST HIGH PWAT AIR WILL MOVE INTO SOUTHEAST TEXAS. IF
THE LOW IS SLIGHTLY SLOWER THE DEEPER MOISTURE WILL BE PUSHED MORE
INTO THE LAKE CHARLES AREA. GIVEN THAT REDEVELOPMENT IS ALREADY
OCCURRING SEEMS LIKE TODAY WE SHOULD SEE GOOD COVERAGE.
BY LATE MONDAY THE LOW WILL CONTINUE PUSHING TO THE WEST ALLOWING
FOR DEEP TROPICAL MOISTURE TO REMAIN IN PLACE. THIS IN COMBINATION
WITH NO REAL LARGE SCALE SUBSIDENCE IN PLACE WILL ALLOW FOR RAIN
CHANCES TO CONTINUE THROUGH THE WORK WEEK. BY THURSDAY THE GFS
HAS SLIGHTLY DRIER AIR (~1.6" PWAT) MOVING IN WHICH COULD HINDER
SOME PRECIP DEVELOPMENT. THE NAM ON THE OTHER HAND STILL HAS PWAT
VALUES AROUND 1.9" EARLY THURSDAY. THE GFS...EUROPEAN AND CANADIAN
ARE ALL SIMILAR WITH KEEPING THE UPPER LEVEL RIDGE OFF TOWARDS THE
NORTH FOR THE SECOND PART OF THIS WEEK. THE RIDGE IS THEN EXPECTED
TO ERODE NEXT WEEKEND. 23
&&
.MARINE...
AS WEAK DISTURBANCES/EASTERLY GULF WAVES COME ASHORE THROUGH
TUESDAY...MARINERS WILL EXPERIENCE PERIODS OF RAIN SHOWERS WITH
EMBEDDED STORMS. U.S. PLAINS HIGH PRESSURE IN RELATION TO LOWER
MEXICO PRESSURE WILL MAINTAIN A TIGHT ENOUGH COASTAL GRADIENT IN
SUPPORTING MODERATE ONSHORE WINDS THROUGH TUESDAY. THIS ENHANCED
SOUTHEASTERLY FETCH WILL DRAW UP A SOUTHWESTERN GULF SWELL LATE
TUESDAY INTO EARLY WEDNESDAY THAT WILL ULTIMATELY INCREASE SEA
HEIGHTS BY A COUPLE OF FEET (UPON TODAY`S HEIGHTS). MID TO LATE WEEK
EAST TO SOUTHEASTERLY FLOW WILL TAME...LOWERING SEA HEIGHTS. AS
BERMUDA-BASED SURFACE HIGH PRESSURE EXPANDS WESTWARD...THE ONSHORE
GRADIENT WILL TIGHTEN UP ONCE AGAIN OVER THE WEEKEND THAT EQUATES TO
STRENGTHENING SOUTHEASTERLY WINDS AND RETURN OFFSHORE SWELL. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 60 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
356 AM CDT MON JUL 15 2013
.SHORT TERM (TODAY THROUGH TUESDAY)...ONGOING MCS NORTH OF
FORECAST AREA SHOULD REMAIN MAINLY NORTH TODAY. UPPER LEVEL LOW
SPINNING CURRENTLY LOCATED OVER SOUTHERN OKLAHOMA...WILL CONTINUE
TO PULL BULK OF ENERGY RESPONSIBLE FOR CURRENT MCS TOWARD THE
EAST. HAVE SOME STREAMER ACTIVITY OVER NEARSHORE WATERS AND
COASTAL COUNTIES THIS MORNING...WELL REPRESENTED IN MESO MODEL
GUIDANCE...INDICATIVE OF INCREASING MOISTURE IN THE AREA.
SATELLITE DERIVED PW SAMPLES INDICATE WE ARE APPROACHING 2 INCH
PWAT ACROSS THE AREA. WILL SEE IF SOUNDING THIS AM CAN CONFIRM
THAT.
BEST MOISTURE TODAY STILL EXPECTED TO BE IN NORTHEAST PORTION OF
CWA...AND WOULD EXPECT BEST CHANCES FOR AFTERNOON CONVECTION TO BE
IN THAT AREA. WITH NO CAP TO SPEAK OF...AND MODERATE CAPE AND
LAPSE RATES THIS AFTERNOON HAVE KEPT A 50 POP WITH THUNDERSTORM
WORDING. DID INCREASE POPS OVER REMAINDER OF NORTHERN FORECAST AREA
AS SOME MESO GUIDANCE...PARTICULARLY THE HRRR INDICATES A BAND OF
SHOWERS DEVELOPING SEPARATE FROM CURRENT MCS AND DRIFTING INTO THE
AREA. THIS BAND IS SHOWING UP ON RADAR AT THIS TIME...BUT DPT
DEPRESSION AT THE SURFACE STILL TOO HIGH FOR RAIN AT THE SURFACE.
IF THIS AREA CAN CONTINUE TO POOL MOISTURE WOULD SEE SOME SHOWERS
NORTH...AND POSSIBLY WEST LATE THIS MORNING OR AFTERNOON.
ADDITIONALLY...GUIDANCE (GLOBAL AND MESO) IN PRETTY GOOD
AGREEMENT IN BRINGING AN MCS THROUGH CENTRAL TEXAS INTO THE RIO
GRANDE VALLEY TONIGHT. MOST GUIDANCE KEEPS THE BULK OF THE PRECIP
NORTH OF THE CWA...JUST SKIMMING LA SALLE AND WEBB COUNTIES. HAVE
INCREASE TO A 40 POP OUT THERE TONIGHT TO ACCOUNT FOR THE
PROXIMITY OF THIS POTENTIAL SYSTEM.
MOVING ON TO TUESDAY...GREATER MOISTURE EXPECTED TO PUSH EAST TO
WEST ACROSS THE AREA DURING THE DAY ON TUESDAY. KEPT PRETTY CLOSE
TO PREVIOUS FORECAST FOR TUESDAY...WITH 40 TO 50 POP ACROSS THE
AREA AS THE UPPER LOW CONTINUES TO RETROGRADE ACROSS NORTH TEXAS.
KEPT TEMPS PRETTY CLOSE TO PREVIOUS FORECAST...THINKING SLIGHTLY
COOLER THAN RECENT DAYS ATTRIBUTED TO INCREASING MOISTURE AND
CLOUD COVER. HIGHS IN THE LOWER TO MID 90S FOR MOST AREAS BOTH
TODAY AND TUESDAY...WITH LOWS TONIGHT IN THE 70S.
&&
.LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...THE INFLUENCE OF THE
UPPER LOW/TROUGH OVER THE CWA WL DIMINISH EARLY IN THE PERIOD
FOLLOWED BY A WEAKNESS IN THE 500MB HEIGHT FIELD OVER THE CWA/MSA
THURSDAY/FRIDAY WITH AN APPROXIMATELY E-W UPPER RIDGE AXIS ACRS THE
CONUS YET NORTH OF THE CWA/MSA (GFS/ECMWF/NAM DETERMINISTIC.) THIS
RIDGE AXIS IS PROGD TO MOVE SWD AND OVER THE CWA/MSA LATE
SATURDAY/SUNDAY (GFS/ECMWF DETERMINISTIC)...YET THE AXIS IS EXPECTED
TO BE WEAK. ALSO DRG THE PERIOD...PERSISTENT ONSHORE FLOW WITH
COPIOUS MSTR/HIGH PWAT VALUES EXPECTED DURING THE PERIOD (GFS
DETERMINISTIC.) THE COMBINATION OF DECREASING UPPER DYNAMICS/MSTR/
INSTABILITY SHOULD RESULT IN SCT CONVECTION WEDNESDAY. THE LACK OF
SIGNIFICANT UPPER FORCING THURSDAY/FRIDAY COMBINED WITH COPIOUS
MSTR SUGGEST DIURNAL CONVECTION MAINLY OVER LAND AND NOCTURNAL
CONVECTION MAINLY OVER THE COASTAL WATERS.
SATURDAY/SUNDAY...ALTHOUGH THE GFS MAINTAINS HIGH PWAT VALUES DRG
THIS PERIOD...ANTICIPATE THAT THE FOREGOING UPPER RIDGE...ALTHOUGH
WEAK...WL DECREASE THE LIKELIHOOD FOR CONVECTION. THUS ANTICIPATE
ONLY ISOLATED CONVECTION. WL FCST LOWER MAX TEMPS THAN GFS MOS
WEDNESDAY-FRIDAY OWING TO EXPECTATION OF EXTREMELY MOIST VERTICAL
COLUMN. ANTICIPATE WARMER MAX TEMPS SATURDAY/SUNDAY CONSIDERING
THE UPPER RIDGE (SLIGHTLY GREATER THICKNESS.)
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 96 77 93 77 88 / 30 30 50 20 40
VICTORIA 94 74 94 73 90 / 50 40 50 20 40
LAREDO 98 78 96 77 93 / 20 30 40 30 50
ALICE 96 75 94 74 90 / 20 30 50 20 40
ROCKPORT 92 78 90 78 87 / 30 40 50 20 40
COTULLA 97 76 96 74 91 / 40 40 50 30 50
KINGSVILLE 97 76 94 76 90 / 20 30 50 20 40
NAVY CORPUS 92 79 90 78 86 / 30 30 50 20 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...SHORT TERM
WC/87...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1252 AM CDT MON JUL 15 2013
.DISCUSSION...UPDATED FOR 06Z TAFS.
&&
.AVIATION...SCATTERED STRATO CU ACROSS THE AREA TONIGHT...COULD GO
BROKEN TEMPORARILY...WITH THE MAIN RISK BEING CRP TAF SITE.
TOMORROW...AS UPPER LOW TRACKS CLOSER TO THE AREA COULD GET SOME
SHOWER ACTIVITY AROUND THE VCT...SMALLER CHANCES AT OTHER SITES.
ALSO SOME CONCERN THAT VCT WILL HAVE PERIODS OF MFVR CIGS DURING
THE DAY...BUT FOR NOW HAVE CIG HEIGHT AT VFR LEVELS.
&&
.PREV DISCUSSION... /ISSUED 912 PM CDT SUN JUL 14 2013/
DISCUSSION...LOWERED (BUT DID NOT REMOVE) RAIN OVER THE NORTHEAST
FOR TONIGHT. ALTHOUGH CONVECTION IS ON THE WANE...SURFACE
CONVERGENCE TONIGHT NEAR THE COAST AND LACK OF CIN COULD RESULT IN
OVERNIGHT SHOWERS/THUNDER OVER THE NORTHEAST ERGO THE POPS IN THAT
AREA. INCREASED CLOUD COVER AND ADJUSTED OTHER FIRST PERIOD
PARAMETERS WHERE NEEDED. DID NOT MESS WITH OVERNIGHT LOWS. REST OF
FORECAST FINE FOR NOW.
PREV DISCUSSION... /ISSUED 631 PM CDT SUN JUL 14 2013/
DISCUSSION...SEE AVIATION DISCUSSION BELOW FOR THE 00Z TAFS.
AVIATION...AS OF 625 PM CDT...RADAR WAS INDICATING SHRA/TSRA`S N
OF THE CWA MOVG S. THERE IS SOME UNCERTAINTY AS TO HOW FAR S THIS
ACTIVITY WILL MOVE DUE TO THE AFFOREMENTIONED REASONS IN THE
PREVIOUS DISCUSSION BELOW. GIVEN THE PROXIMITY OF THE CONVECTION
TO VCT...DECIDED TO INCLUDE A TEMPO WITH TSRA UNTIL 02Z.
OTHERWISE...CIGS/VSBYS ARE EXPECTED TO BE AT VFR LEVELS THROUGH
MUCH OF THE TAF PERIOD. INCREASING MOISTURE THROUGH MON MAY LEAD
TO ISOLD/SCT SHRA`S ALONG THE SEA BREEZE AND ADDITIONAL CONVECTION
POSSIBLY MOVING INTO THE NRN CWA FROM THE HILL COUNTRY. FOR NOW
WENT WITH VCSH FOR THE LATTER PART OF THE VCT TAF WHERE CHCS ARE
BEST.
PREV DISCUSSION... /ISSUED 619 PM CDT SUN JUL 14 2013/
DISCUSSION...LAPS DATA AND HRRR MODEL DATA STILL SUGGESTING THAT
CONVECTION ALONG THE BOUNDARY SHOULD WEAKEN AND DISSIPATE BEFORE
IT GETS MUCH FARTHER EAST. STILL...ACTIVITY STILL GETTING A BIT
TOO CLOSE TO VICTORIA AREA NOT TO INCREASE POPS AT LEAST INTO THE
CHANCE CATEGORY. LAPS NOW SHOWING A BIT OF A CAP STARTING TO FORM
JUST SOUTH OF VICTORIA...WE WILL SEE IF THIS IS ENOUGH. IN ANY
CASE...DECIDED TO UPDATE FORECAST FOR AFOREMENTIONED ACTIVITY.
WILL MONITOR FOR FURTHER UPDATES AS NEEDED. PRODUCTS ARE OUT.
PREV DISCUSSION... /ISSUED 328 PM CDT SUN JUL 14 2013/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...MAIN AREA OF SHOWERS
AND THUNDERSTORMS IS CURRENTLY LOCATED OVER EAST CENTRAL TEXAS.
ADDITIONAL CONVECTION HAS DEVELOPED ALONG SOUTHWARD MOVING
BOUNDARY OVER SOUTH CENTRAL TEXAS...AND THIS ACTIVITY MAY MOVE
INTO THE REGION LATER THIS AFTERNOON/EVENING. LATEST LAPS DATA
SHOWS CAPE VALUES BETWEEN 1500 AND 2000 J/KG OVER THE EASTERN
PARTS OF THE CWA. IF CONVECTION CAN CONTINUE TO MOVE SOUTHWARD
INTO THE AREA...THEN A FEW STRONGER STORMS WITH LOCALLY HEAVY
RAINFALL COULD BE POSSIBLE LATE THIS AFTERNOON/EARLY EVENING
MAINLY OVER THE NORTHERN AND NORTHEAST ZONES. CURRENT FORECAST HAS
THIS ACCOUNTED FOR THE SLIGHT END POPS OVER THESE LOCATIONS.
MOISTURE AND CLOUD COVER INCREASES FURTHER TONIGHT AND ALONG WITH
CONTINUED SOUTHERLY WINDS SHOULD LEAD TO A WARM NIGHT ACROSS SOUTH
TEXAS. OVERNIGHT LOWS WILL BE IN THE MID/UPPER 70S AND INCREASED
TEMPS OVER MAVMOS VALUES. UPPER LOW WILL CONTINUE TO TRACK
WESTWARD ACROSS OKLAHOMA AND NORTH TEXAS ON MONDAY. WEAKNESS IN
FLOW ALOFT WITH LITTLE TO NO CAPPING SHOULD ONCE AGAIN PROVE
SUFFICIENT FOR SHOWER AND THUNDERSTORM DEVELOPMENT. HIGHEST
CHANCES WILL BE OVER THE VICTORIA CROSSROADS WHERE BETTER MOISTURE
WILL RESIDE. HIGHS ON MONDAY WILL BE SET BACK A FEW DEGREES
(THOUGHT STILL IN THE 90S) DUE TO CLOUD COVER AND RAIN CHANCES...
AND HAVE EITHER GONE WITH OR UNDERCUT GUIDANCE BY A FEW DEGREES.
LONG TERM (TUESDAY THROUGH SUNDAY)...MAIN FORECAST CHALLENGE FOR
TODAY CONTINUES TO BE POP PLACEMENT/COVERAGE THROUGH THE WORK WEEK.
ALL GUIDANCE SUITES CONTINUE TO ADVERTISE POTENTIALLY WET WEEK FOR
SOUTH TEXAS AS DEEP TROPICAL MOISTURE IS PROG TO EXIST FROM TUESDAY
THROUGH THURS/FRI. THE INTERACTION BETWEEN THE DEEP MOISTURE...
PERIODIC POS VORT ADVECTION...WEAK ELONGATED TUTT SIGNATURE...WEAK
SURFACE TROUGHING...AND ANY MESOSCALE BOUNDARIES /OUTFLOW
BOUNDARIES AND SEABREEZE...SHOULD ALL LEAD TO A SCATTERING OF
SHOWERS AND THUNDERSTORMS FROM TUESDAY THROUGH THURSDAY. TUESDAY/S
PRECIP CHANCES SHOULD BE BASED ON PIECE OF H5 VORTICITY DRIFTING
OUT OF OLD MEX AND INTERACTING WITH UNSTABLE AIRMASS AND DEEP
MOISTURE THAT SHOULD ALREADY BE IN PLACE. WED AND THURSDAY/S
CHANCES ARE BASED ON WEAK INVERTED SURFACE TROUGH AND WEAK TUTT
STRETCHING INTO THE REGION...WHICH ONCE AGAIN SHOULD LEAD TO A
SCATTERING OF SHOWERS AND THUNDERSTORMS. GIVEN DEEP MOISTURE OF
AOA 2 INCHES...LOCALLY HEAVY RAINFALL WILL BE POSSIBLE THIS
WEEK...BUT AT THIS TIME WIDESPREAD FLOODING RAINS ARE NOT
EXPECTED. SLIGHT CHANCES OF PRECIP MAY CONTINUE FRIDAY AND INTO
NEXT WEEKEND...BUT WILL BE DEPENDENT ON HOW MUCH DRIER AIR CAN
WORK ITS WAY INTO THE AREA AS H85 HIGH SHIFTS FARTHER EAST FROM
THE MIDWEST TO THE SE COAST. MAX TEMPS THIS WEEK WILL BE STRONGLY
DEPENDENT ON COVERAGE OF PRECIP AND CLOUD COVER...FOR NOW HAVE
GONE A LITTLE ON THE WARM SIDE GIVEN THAT WE SHOULD NOT HAVE
WIDESPREAD CLOUD COVER EVERY DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 94 77 94 77 95 / 30 30 50 30 50
VICTORIA 91 75 93 74 94 / 50 30 50 30 50
LAREDO 98 78 97 78 97 / 20 30 50 30 50
ALICE 96 76 94 75 96 / 20 30 50 30 50
ROCKPORT 88 79 92 77 92 / 30 30 50 40 50
COTULLA 96 76 97 75 97 / 20 30 50 30 50
KINGSVILLE 96 77 94 77 95 / 20 30 50 30 50
NAVY CORPUS 88 80 91 78 91 / 30 30 50 40 50
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS AMARILLO TX
1117 PM CDT SUN JUL 14 2013
.AVIATION...
ANY SHOWERS AND THUNDERSTORMS SHOULD BE SOUTHWEST OF THE TAF SITES AT
THE START OF THIS FORECAST. STILL BELIEVE THAT CIGS WILL FALL INTO
THE MVFR RANGE AT ALL SITES AFTER ABOUT 10Z. THE CIGS SHOULD THEN
LIFT INTO THE VFR RANGE BY LATE MORNING ON MONDAY. SOME SHOWERS AND
THUNDERSTORMS MAY BE FOUND ACROSS THE AREA MONDAY AFTERNOON INTO
MONDAY EVENING...BUT CONFIDENCE IS NOT HIGH ENOUGH THAT ANY ONE THESE
WILL AFFECT A TAF SITE...SO WILL LEAVE THE MENTION OF THEM OUT OF
THIS FORECAST. SOUTHEAST WINDS WILL TURN MORE EASTERLY DURING THE DAY
ON MONDAY. WIND SPEEDS SHOULD GENERALLY BE IN THE 10 TO 15 KNOT RANGE.
&&
.PREV DISCUSSION... /ISSUED 605 PM CDT SUN JUL 14 2013/
AVIATION...
ANOTHER BAND OF SHOWERS AND ISOLATED THUNDERSTORMS MAY DEVELOP NORTH
OF THE CWA AND TRANSLATE SOUTHWARD THIS EVENING. HAVE GONE AHEAD AND
ADDED A TEMPO GROUP AT ALL TAF SITES FOR -SHRA AND MVFR CIGS THIS
EVENING FOR A 4 HOUR TIME PERIOD. AFTER THE SHOWERS PASS...MVFR CIGS
WILL PREVAIL AT GUY AND DHT WITH IFR CIGS AT AMA. THE LOW CLOUDS ARE
EXPECTED TO DECREASE BY LATE MORNING ON MONDAY AND A VFR CLOUD LAYER
WILL PREVAIL FOR THE REST OF THE FORECAST. GUSTY SOUTHEAST WINDS WILL
DECREASE LATE THIS EVENING AND THEN THEY WILL BECOME MORE EASTERLY
AFTER 06Z. MORE SHOWERS AND THUNDERSTORMS MAY DEVELOP MONDAY
AFTERNOON WITH AMA BEING THE MOST FAVORED...BUT CONFIDENCE IS NOT
HIGH ENOUGH TO ADD TO THE TAF AT THIS POINT.
PREV DISCUSSION... /ISSUED 310 PM CDT SUN JUL 14 2013/
SHORT TERM...
COLD FRONT NOW THROUGH ALL OF THE PANHANDLES AS OF 3 PM CDT. IN ITS
WAKE...DECREASING TEMPERATURES AND SCATTERED SHOWERS ACROSS.
FOR TONIGHT...SHOULD SEE COVERAGE OF SHOWERS INCREASE A BIT AND HIGH
RESOLUTION MODELS LIKE THE HRRR AND TTU WRF CONTINUE TO SHOW THIS
TREND. WITH VERY LIMITED INSTABILITY...EXPECT THE ACTIVITY TO
PRIMARILY BE LIGHT RAIN SHOWERS...THOUGH AN ISOLATED THUNDERSTORM IS
POSSIBLE.
TOMORROW THROUGH TUESDAY...EXPECT A LULL IN THE PRECIP STARTING SOMETIME
EARLY TOMORROW MORNING AND CONTINUING THROUGH MID DAY AS THE REGION
WILL BE ON THE DRIER NW SIDE OF THE LOW. AS THE LOW CONTINUES TO
SLIDE EAST TOMORROW NIGHT...EXPECT PRECIP TO SPREAD FROM EAST TO WEST
ONCE AGAIN...AS BETTER LIFT IS EXPECTED ON THE EASTERN SIDE OF THE
UPPER LEVEL LOW. STILL SOME QUESTION AS TO HOW FAR NORTH MOISTURE
WILL ADVECT AND IF CONVECTION FURTHER DOWN STATE WILL ROB SOME OF THE
MOISTURE ADVECTION FOR THE PANHANDLES. STILL THINK THE BEST CHANCE
WILL BE TOMORROW NIGHT...WITH CHANCES DECREASING AFTER THAT.
LONG TERM...
WEDNESDAY THROUGH THURSDAY...COULD STILL SEE SOME LINGERING
CONVECTION EVEN THOUGH THE LOW WILL BE PROPAGATING OVER NORTHERN
MEXICO BY THIS POINT...THE RESULTING MID AND UPPER LEVEL
SOUTHEASTERLY FLOW SHOULD RESULT IN A MOIST FETCH FROM THE GULF.
FRIDAY THROUGH SUNDAY...CONSIDERABLE UNCERTAINTY IN THE UPPER LEVEL
PATTERN THROUGH THIS PERIOD. GFS SHOWS VERY WEAK FLOW OVER THE REGION
THROUGH THIS PERIOD...WITH THE HIGH BUILDING OVER THE WESTERN U.S.
WHILE THE ECMWF SHOWS THE HIGH BUILDING OVER THE ROCKIES THEN SLIDING
SE TOWARDS THE PANHANDLES. EITHER WAY...IT SHOULD BE A DRIER
PATTERN...WITH THE POSSIBLE EXCEPTION OF SOME MOUNTAIN CONVECTION
SLIDING INTO THE NW CORNER ON SATURDAY UNDER VERY WEAK NW FLOW.
JOHNSON
FIRE WEATHER...
MUCH COOLER WEATHER...RAIN CHANCES...AND RELATIVE HUMIDITY VALUES
WELL ABOVE 20 PERCENT WILL PRECLUDE ANY ELEVATED OR CRITICAL FIRE
WEATHER CONDITIONS FOR THE NEXT SEVERAL DAYS.
JOHNSON
&&
.AMA WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
OK...NONE.
&&
$$
15/11
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1145 PM CDT SUN JUL 14 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
MAIN FORECAST CONCERN IS ON THUNDERSTORM POTENTIAL FOR MONDAY.
CURRENTLY AS OF 19Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A SHARP SHORTWAVE TROUGH OVER BRITISH COLUMBIA...AN UPPER LOW
OVER EASTERN OKLAHOMA...A SHORTWAVE TROUGH STRETCHING FROM NORTHERN
MN INTO EASTERN SOUTH DAKOTA...AND THE BERMUDA HIGH OVER THE EASTERN
GREAT LAKES. 500MB HEIGHTS ASSOCIATED WITH THE BERMUDA HIGH ARE
QUITE IMPRESSIVE...NEARING 600 DAM OR 2.5 STANDARD DEVIATIONS ABOVE
NORMAL. DESPITE THE SUBSTANTIAL 500MB HEIGHTS...850MB TEMPS ARE ONLY
IN THE 15-18C UNDERNEATH IT PER 12Z RAOBS OR NEAR 1 STANDARD
DEVIATION ABOVE NORMAL. THE WESTERN EXTENT OF THE SUBTROPICAL RIDGE
HAS BEEN PROVIDING SUBSIDENCE OVER THE FORECAST AREA...RESULTING IN
DRY CONDITIONS WITH JUST SOME DIURNAL CUMULUS CLOUDS. TO OUR
WEST...A STREAM OF PRECIPITABLE WATER VALUES OF 1.65 TO 2 INCHES
PER GOES DERIVED IMAGERY STRETCHED FROM CENTRAL OKLAHOMA TO
EASTERN SOUTH DAKOTA AND NORTHERN MN. THIS STREAM OF HIGH MOISTURE
IS CO-LOCATED WITH THAT SHORTWAVE TROUGH IN THE NORTHERN PLAINS
AND DEFORMATION ON THE WEST SIDE OF THE UPPER LOW. NUMEROUS
SHOWERS AND THUNDERSTORMS WERE PRESENT IN THE STREAM.
EXPECT THE RETROGRADING 500MB PATTERN TO CONTINUE THROUGH THE SHORT
TERM PERIOD...SUCH THAT BY 00Z TUESDAY MODELS FORECAST THE BERMUDA
HIGH TO BE SITUATED NEAR THE OHIO/INDIANA BORDER. THIS RETROGRESSION
MEANS 500MB HEIGHTS ARE GOING TO RISE OVER THE FORECAST AREA...
IMPLYING SUBSIDENCE. NOT ANTICIPATING ANY PRECIPITATION TONIGHT
BEING IN THE NOCTURNAL COOLING PERIOD AND RISING HEIGHTS ALOFT. ON
MONDAY...DESPITE BEING UNDER THE SUBSIDENCE OF THE RISING HEIGHTS
ALOFT...NEARLY EVERY MODEL DEPICTS ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT BETWEEN 18Z-00Z OVER THE FORECAST AREA.
THE REASONING FOR THE PRECIPITATION IS A COMBINATION OF FACTORS:
1. SOUTHEAST WINDS ADVECTING IN 70+ SURFACE DEWPOINTS...WHICH ARE
ACCOMPANYING THE BERMUDA HIGH AND ENHANCED BY EVAPOTRANSPIRATION
FROM VEGETATION.
2. STREAM OF HIGHER PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES
COMING UP OUT OF GEORGIA AND ALABAMA CURRENTLY.
3. DAYTIME HEATING COMBINING WITH THE HIGHER DEWPOINTS TO BUILD UP
INSTABILITY. MIXING TO 850MB TEMPS OF 16-17C SHOULD YIELD HIGHS IN
THE MID TO UPPER 80S.
4. SOUNDINGS DEPICT NO CAPPING
LOOKING AT VARIOUS PRESSURE LEVELS FOR CONVERGENCE...IT IS VERY
DIFFICULT TO FIND ANY. THUS...IT APPEARS THE LACK OF CAPPING AND THE
HIGHER DEEPER MOISTURE ITSELF WILL RESULT IN POP UP SHOWERS AND
THUNDERSTORMS. 0-6KM SHEAR VALUES OF LESS THAN 20 KT MEANS THESE
STORMS ARE GOING TO BE PULSE AND NON-SEVERE...WITH OUTFLOWS
PRODUCING ADDITIONAL SHOWERS AND THUNDERSTORMS. MAIN CONCERN WITH
THIS PRECIPITATION IS BRIEF HEAVY RAIN GIVEN THE PRECIPITABLE WATER
VALUES AND DEEP WARM CLOUD DEPTHS.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 250 PM CDT SUN JUL 14 2013
THE RETROGRESSION 500MB PATTERN CONTINUES FROM THE SHORT TERM PERIOD
RIGHT INTO NEXT WEEKEND. 14.12Z ECMWF/CANADIAN/GFS AND 14.00Z ECMWF
ENSEMBLE MEAN ALL SHOW THAT THE BERMUDA HIGH WILL SLOWLY MOVE
WESTWARD THROUGH THE WEEK...SUCH THAT BY LATE FRIDAY INTO THE
WEEKEND TROUGHING DOMINATES MUCH OF CANADA INTO THE WESTERN GREAT
LAKES REGION.
MONDAY NIGHT THROUGH WEDNESDAY...
CONVECTION THAT FORMED MONDAY AFTERNOON SHOULD DISSIPATE PRETTY
QUICK IN THE EVENING...LIKELY BY 03Z...AS THE LOSS OF DAYTIME
HEATING DIMINISHES THE INSTABILITY. THE REST OF THE NIGHT INTO
TUESDAY MORNING LOOKS DRY WITH THE MAIN FORCING FOR NOCTURNAL
CONVECTION WELL OFF TO THE NORTHWEST IN THE DAKOTAS. A SIMILAR SETUP
TO MONDAY AFTERNOON LOOKS TO OCCUR FOR TUESDAY AFTERNOON WITH
DEWPOINTS IN THE UPPER 60S TO LOW 70S...HIGHS A FEW DEGREES WARMER
GIVEN 850MB TEMPS PROGGED BETWEEN 18-19C...AND HIGHER CAPE VALUES
DUE TO THESE READINGS. HOWEVER...MODELS ARE MUCH LESS AGGRESSIVE
WITH QPF...AND THIS APPEARS TO STEM FROM PRECIPITABLE WATER VALUES
THAT ARE 0.25-0.5 INCH LOWER. GIVEN THAT THE 14.12Z NAM WHICH IS
USUALLY AGGRESSIVE IN THESE SCENARIOS AND HAPPENS TO BE DRY...AND
COLLABORATION WITH SURROUNDING OFFICES...WENT DRY FOR TUESDAY.
SHOWERS AND THUNDERSTORMS STILL LOOK POSSIBLE NORTH AND EAST OF THE
FORECAST AREA...ASSOCIATED WITH LAKE BREEZES RUNNING INTO THE
UNSTABLE AIR. A COMPLETE REPEAT OF THE WEATHER HAPPENS TUESDAY NIGHT
AND WEDNESDAY...AND HERE AGAIN MODELS ARE NOT THAT AGGRESSIVE WITH
QPF WEDNESDAY AFTERNOON STEMMING FROM SIMILAR PRECIPITABLE WATER
VALUES TO TUESDAY. REMOVED THE 20 PERCENT CHANCES FOR WEDNESDAY.
SAFE TO SAY THAT IF INDEED NO PRECIPITATION HAPPENS TUESDAY...
WEDNESDAY WILL END UP DRY TOO. HIGHS ON WEDNESDAY ARE LIKELY TO BE
SIMILAR TO TUESDAY WITH 850MB TEMPS HOVERING AROUND 19C...YIELDING
READINGS IN THE UPPER 80S TO LOWER 90S.
WITH TUESDAY AND WEDNESDAY AFTERNOON DEWPOINTS IN THE UPPER 60S TO
LOWER 70S AND HIGHS IN UPPER 80S TO LOWER 90S...HEAT INDICES ARE
LIKELY TO CLIMB INTO THE 95-100 RANGE. THESE ARE JUST UNDER HEAT
ADVISORY CRITERIA. SHOULD EITHER DEWPOINTS OR TEMPERATURES GET
HIGHER THAN FORECAST...HEAT ADVISORIES MAY BE REQUIRED.
WEDNESDAY NIGHT THROUGH SUNDAY...
THE PROGGED SWITCH IN THE UPPER FLOW TO MORE NORTHWESTERLY ALLOWS
A COLD FRONT SITUATED OVER NORTHERN MN AND UPPER MI ON WEDNESDAY
TO SLOWLY DRIFT SOUTH. THE TIMING OF WHEN THIS BOUNDARY CROSSES
THE FORECAST AREA LOOKS TO BE MODULATED BY A SHORTWAVE DROPPING
THROUGH NORTH DAKOTA...WHICH COULD STALL OR EVEN SEND THE FRONT
BACK NORTHWARD THURSDAY NIGHT AS SUGGESTED BY THE 14.00Z/14.12Z
ECMWF. MOST MODELS AGREE ON A TIMING OF THE COLD FRONT CROSSING
THE AREA FRIDAY INTO FRIDAY EVENING...WITH PERHAPS THE FRONT
COMING INTO NORTHERN SECTIONS OF THE FORECAST AREA WEDNESDAY
NIGHT. GIVEN PLENTIFUL INSTABILITY IN PLACE AHEAD OF AND AROUND
THE BOUNDARY...AS WELL AS A PLUME OF HIGHER PRECIPITABLE WATER
VALUES ON THE ORDER OF 1.75-2 INCHES...DEFINITELY NEED CHANCES OF
SHOWERS AND THUNDERSTORMS. THERE ARE INDICATIONS OF POSSIBLE MCS
ACTIVITY TOO...ESPECIALLY THURSDAY AFTERNOON AND NIGHT NORTH OF
I-90 WHICH IS WHERE CHANCES OF PRECIPITATION ARE ON THE ORDER OF
50-60. ONE PORTION OF THE FORECAST WHERE CHANCES MAY BE ABLE TO BE
REMOVED IS FRIDAY NIGHT...SINCE THERE ARE SOME INDICATIONS OF THE
FRONT AND ASSOCIATED CONVECTION GETTING OUT OF THE AREA IN TIME.
HIGH PRESSURE BUILDS IN FOR SATURDAY AND SATURDAY NIGHT...BRINGING
DRIER CONDITIONS. UNCERTAINTY INCREASES FOR SUNDAY WITH
INDICATIONS OF SOME SHORTWAVE TROUGH DROPPING THROUGH IN THE
NORTHWEST FLOW. HAVE FOLLOWED A MODEL CONSENSUS OF 20-40 PERCENT
CHANCES FOR NOW.
SOME SEVERE WEATHER IS POSSIBLE THURSDAY THROUGH FRIDAY...WITH 0-6KM
SHEAR VALUES PROGGED OF 30-35 KT ALONG THE COLD FRONT. DAMAGING
WINDS AND HEAVY RAIN WOULD APPEAR TO BE THE MAIN HAZARDS. LOCATIONS
NORTH OF I-90 SEEM TO BE CENTERED ON HAVING THE MOST RAIN DURING
THIS PERIOD...WHICH IS AN AREA THAT NOT ONLY CAN HANDLE THE RAIN BUT
NEEDS IT.
TEMPERATURES THURSDAY THROUGH FRIDAY ARE QUITE TRICKY. 850MB TEMPS
UPWARDS OF 20C COULD EASILY SUPPORT HIGHS IN THE LOW TO EVEN PERHAPS
MID 90S...AND WITH DEWPOINTS UP IN THE LOW 70S WOULD YIELD HEAT
INDICES AGAIN IN THE 95-100 RANGE. HOWEVER...THERE IS CONVECTION TO
WORRY ABOUT...ESPECIALLY ON FRIDAY. THUS...HIGH TEMPERATURES ARE
ONLY FORECAST IN THE MID 80S TO LOW 90S AT THIS TIME. 850MB TEMPS
FALLING INTO THE 13-15C RANGE FOR SATURDAY AND ONLY CLIMBING ABOUT
1C HIGHER ON SUNDAY WILL RESULT IN COOLER TEMPERATURES...UPPER 70S
TO MID 80S.
&&
.AVIATION...THROUGH 06Z TUESDAY
1145 PM CDT SUN JUL 14 2013
HIGH PRESSURE IN PLACE OVER THE AREA...RETROGRADING WESTWARD INTO
THE REGION. AS GRADIENT WEAKENED THIS EVENING FLOW BECAME MORE
EASTERLY AND SLACKENED. WITH LIGHT WINDS...COOLING TEMPS...AND
INCREASING LOW LEVEL MOISTURE...FEEL SOME PATCHES OF LIGHT
FOG/MIST WILL BE SEEN FOR A FEW HOURS AROUND SUNRISE. LATEST
SURFACE OBSERVATIONS AND SATELLITE FOG ENHANCEMENT SHOWING SOME
SCATTERED CLOUD DEVELOPING AROUND 5KFT IN A SOUTHWEST TO NORTHEAST
BAND. MODELS DID HINT AT THIS...AND PROPAGATE IT TO THE NORTH AND
NORTHEAST OVERNIGHT.
AS MOISTURE AND INSTABILITY BUILDS ON MONDAY...ANTICIPATE SOME
SHOWERS TO BREAK OUT FOR THE AFTERNOON AND EARLY EVENING HOURS.
MAIN FOCUS FOR THIS ACTIVITY WILL BE ACROSS IOWA/ILLINOIS...BUT
SOME SHOULD DRIFT NORTH INTO BOTH TAF LOCATIONS AND ADDED THIS TO
THE FORECASTS. ACTIVITY SHOULD DIMINISH DIURNALLY IN THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1124 PM MDT SUN JUL 14 2013
.UPDATE...
ISSUED AT 848 PM MDT SUN JUL 14 2013
OVERALL AN UNEVENTFUL EVENING ACROSS THE CWA...DESPITE THE SURFACE
DEWPOINTS IN THE 60S AND PRECIPITABLE WATER VALUES THAT ARE
RUNNING 150 TO 200 PERCENT OF NORMAL. THICKER DAYTIME CLOUD COVER
CERTAINLY THWARTED SOME OF THE INSTABILITY. BUT THE PRIMARY
HINDRANCE HAS BEEN THE LACK OF A TRIGGER. THE ORIGINAL THOUGHT WAS
THAT OROGRAPHIC ASCENT WOULD BE SUFFICIENT IN CONVECTIVE
DEVELOPMENT...WHICH OBVIOUSLY HAS NOT BEEN THE CASE. OUTSIDE OF
A FEW ISOLATED THUNDERSTORMS...MUCH OF THE CWFA HAS REMAINED DRY.
INITIAL LOOK AT 00Z GUIDANCE SHOWS ANY HOPE OF CONVECTION FADING
THROUGH THE OVERNIGHT HOURS AS RIBBON OF MOISTURE THINS AS IT
BACKS TO THE WEST THROUGH THE CWA. COULD STILL SEE SOME SHOWERS
AND EVEN EMBEDDED THUNDER DEVELOP THRU THE NIGHT...BUT ANY HOPE IS
QUICKLY FADING. SO...IN AN EARLIER UPDATE BEGAN SCALING BACK
PRECIPITATION CHANCES ACROSS THE ENTIRE AREA TONIGHT. THE OTHER
CONCERN IS THE POTENTIAL FOR FOG DEVELOPMENT AFTER MIDNIGHT GIVEN
THE VERY MOIST LLVLS. BOTH THE SREF AND HRRR ARE POINTING TO ITS
DEVELOPMENT ALONG THE LARAMIE RANGE AND ADJACENT EASTERN
FOOTHILLS. GIVEN ESE LLVL FLOW...THIS SEEMS TO BE PLAUSIBLE. SO
HAVE ADDED AREAS OF FOG ACROSS MOST OF THE EASTERN PLAINS FOR LATE
TONIGHT AND EARLY MONDAY.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
VERY MOIST AIRMASS IS CURRENTLY OVER THE CWA WITH MANY AREAS TO
THE EAST OF THE LARAMIE RANGE SEEING 60S DEWPOINTS. THE EXTENSIVE
LOW AND MIDLEVEL CLOUD COVER THAT HAS OCCURRED THROUGH THE EARLY
AFTERNOON HAS LIMITED SFC HEATING AND INSTABILITY. HOWEVER...VISIBLE
IMAGERY SHOWS THE PLAINS STARTING TO CLEAR AND LAPS ANALYSIS
INDICATES WIDESPREAD 500-1000 J/KG OF CAPE. BELIEVE THERE COULD BE
AN UPTICK IN CONVECTIVE ACTIVITY DURING THE EARLY EVENING OVER THE
SOUTHERN ZONES DESPITE THE LATE START. THE SFC TROUGH AND
ASSOCIATED HIGHEST DEWPOINT/PW VALUES IS JUST TO THE EAST OF THE
CWA AND IS PROGGED TO CONTINUE MOVING WESTWARD THROUGH THE NIGHT.
THE MOST IMPRESSIVE CONVECTION IS CURRENTLY IN THE CONVERGENCE
ALONG THAT TROUGH...OUTFLOW FROM THIS CONVECTION SHOULD BE ABLE TO
INITIATE CONVECTION IN THE SOUTHERN PANHANDLE DURING THE EVENING.
STILL HAVE HEAVY RAIN IN THE GRIDS THROUGH THE NIGHT WITH PW
VALUES AROUND 1.3 INCHES AND SLOW STEERING FLOW (700-300MB FLOW IS
AROUND 5-10 KTS). AREAS IN SCOTTS BLUFF COUNTY PICKED UP AROUND 2
INCHES OF RAINFALL IN A FEW HOURS EARLIER THIS AFTERNOON...A
TESTAMENT TO THE HEAVY RAIN POTENTIAL. THE PW RIDGE AXIS IS IN
EXTREME SOUTHEAST WY BY MONDAY MORNING SO CONTINUED THE THREAT OF
SHOWERS THROUGH THE NIGHT ACROSS MUCH OF THE PLAINS.
UPPER LOW AND ITS ASSOCIATED MIDLEVEL MOISTURE PLUME CONTINUE TO
MOVE WESTWARD ON MONDAY. PW VALUES ARE HIGHEST (AROUND 1 INCH)
ACROSS SOUTHEAST WY WITH A CONSIDERABLE DROP IN THE PANHANDLE.
HAVE CHANCE POPS MAINLY ALONG AND WEST OF THE LARAMIE RANGE DURING
THE AFTN AND EVENING...NOT EXPECTING MUCH FURTHER EAST. STEERING
FLOW CONTINUES TO BE WEAK SO THE HEAVY RAIN THREAT WILL BE
THERE...ESPECIALLY IN THE HIGHER TERRAIN WHERE COVERAGE OF STORMS
WILL BE BEST. TEMPS WARM AROUND 5 DEGREES ON MONDAY WITH LESS
CLOUD COVER...ESPECIALLY IN NEBRASKA. THE DRYING TREND THAT HAS
BEEN PROGGED FOR TUESDAY CONTINUES TO LOOK ON TRACK. WITH PW
VALUES AT 0.5-0.75 INCHES AND LI VALUES ON THE GFS STRUGGLING TO
GET NEGATIVE...STORM POTENTIAL WILL REALLY DROP OFF. SLIGHT CHANCE
POPS ARE CONFINED TO THE SIERRA MADRE AND SNOWY RANGES.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 350 PM MDT SUN JUL 14 2013
TUESDAY NIGHT...EVENING THUNDERSTORMS ACROSS THE SIERRA MADRE RANGE
IN UPSLOPE...OTHERWISE DRY.
WEDNESDAY...UPPER RIDGE AXIS OVER OUR COUNTIES. SURFACE LOW AND LOW
LEVEL CONVERGENCE AXIS OVER OUR SNOWY AND SIERRA MADRE RANGES...
WHERE SCATTERED AFTERNOON THUNDERSTORMS ON TAP...DRY ELSEWHERE WITH
SUBSIDENCE AND CONVECTIVE INHIBITION.
THURSDAY...RIDGE ALOFT WEAKENS SLIGHTLY AND WITH SLIGHTLY MORE LOW
AND MID LEVEL MOISTURE...EXPECT SCATTERED AFTERNOON THUNDERSTORMS
OVER THE NORTHERN...SNOWY AND SIERRA MADRE RANGES...DRY ELSEWHERE.
FRIDAY...MONSOONAL MOISTURE TAP RETURNS OVER OUR COUNTIES AND WITH
LOW LEVEL UPSLOPE WINDS AND PLENTY OF LOW AND MID LEVEL MOISTURE...
WILL SEE SCATTERED AFTERNOON SHOWERS AND THUNDERSTORMS...MOST
NUMEROUS OVER THE MOUNTAINS.
SATURDAY...DEEPER MONSOONAL MOISTURE FEED TRANSLATES SOUTH ACROSS
COLORADO...THOUGH STILL ENOUGH MOISTURE FOR ISOLATED TO SCATTERED
LATE DAY THUNDERSTORMS FOCUSED NEAR THE MOUNTAINS.
SUNDAY...DRIER AIRMASS ADVECTS IN ON NORTHWEST FLOW ALOFT...THUS
ONLY ISOLATED LATE DAY THUNDERSTORMS ON TAP OVER THE MOUNTAINS...DRY
ELSEWHERE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY EVENING)
ISSUED AT 1124 PM MDT SUN JUL 14 2013
FAIRLY WIDESPREAD IFR/LIFR CIGS EXPECTED ACROSS MUCH OF THE NEB
PANHANDLE INTO FAR ERN WYOMING INTO MONDAY MORNING IN MOIST UPSLOPE
FLOW. AREAS OF FOG AS WELL LOWERING VSBYS TO LESS THAN 3 MILES IN
SOME SPOTS. CONDITIONS SHOULD IMPROVE SLOWLY AFTER SUNRISE.
ISOLATED SHOWERS AND A FEW TSTRMS POSSIBLE MONDAY AFTERNOON INTO
MONDAY EVENING MAINLY OVER AND EAST OF THE MTNS.
&&
.FIRE WEATHER...
ISSUED AT 350 PM MDT SUN JUL 14 2013
NO FIRE WEATHER CONCERNS THROUGH EARLY NEXT WEEK. A VERY MOIST
AIRMASS IS CURRENTLY AFFECTING THE REGION WITH SCATTERED SHOWERS
AND THUNDERSTORMS POSSIBLE THROUGH THE EARLY NIGHT. THIS MOIST
AIRMASS WILL CONTINUE MOVING WESTWARD WITH ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS ON MONDAY AFTERNOON AND EVENING...MAINLY
ALONG AND WEST OF THE LARAMIE RANGE. STORM CHANCES WILL REALLY
DROP BY TUESDAY AS MIDLEVEL MOISTURE PUSHES OUT OF THE REGION.
WINDS WILL GENERALLY BE BELOW 20 MPH THROUGH TUESDAY...EXCEPT IN
THE VICINITY OF STORMS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...HAHN
SHORT TERM...FINCH
LONG TERM...RUBIN
AVIATION...RE
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS ALBANY NY
640 AM EDT MON JUL 15 2013
.SYNOPSIS...
HOT AND HUMID CONDITIONS ARE EXPECTED THROUGH MOST OF
THIS UPCOMING WEEK AS A LARGE RIDGE OF HIGH PRESSURE EXPANDS ACROSS
MOST OF THE NATION. CHANCES FOR SHOWERS AND THUNDERSTORMS WILL
GRADUALLY INCREASE AS THE WEEK PROGRESSES WHICH COULD OCCUR DURING
THE AFTERNOON AND EVENING HOURS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM EDT...SCT-BKN AC DECK WAS DRAPED FROM WESTERN NY INTO
THE CATSKILLS AND MID HUDSON VALLEY. THIS SEEMS TO BE THE DIVISION
DEWPOINT LINE AND LATEST HRRR EXPERIMENTAL REFLECTIVITIES STILL
KEEPS OUR REGION DRY. SO NO MAJOR CHANGES TO THE CURRENT FORECAST
JUST A REFRESH OF HOURLY GRIDS.
AS OF 400 AM EDT...UPPER AIR PATTERN OVER EASTERN 2/3RDS OF THE
CONUS REMAINS SOMEWHAT RETROGRESSIVE AS LARGE UPPER HIGH WAS
CENTERED OVER THE OHIO RIVER VALLEY AND UPPER LOW OVER THE RED
RIVER VALLEY. THIS WILL KEEP OUR WEATHER PATTERN RATHER QUIET WITH
RESPECT TO CONVECTIVE POTENTIAL BUT RATHER WARM/HOT AND MUGGY
CONDITIONS. H500 TEMPS ARE EXPECTED TO BE AOA -6C WITH H700 TEMPS
AOA +10C...SO A VERY WARM AND CAPPED ENVIRONMENT. FORECAST BUFR
PROFILES TODAY POINT TOWARD EFFECTIVE MIXING LAYER HEIGHTS AROUND
H825 WHERE +17C ISOTHERM RESIDES. DRY ADIABATIC DECENT POINTS
TOWARD 90+ FOR VALLEY LOCATIONS AND 80S FOR THE HIGHER TERRAIN.
QUESTION FOR TODAY WILL BE THE DEWPOINTS AND ITS IMPACTS TO THE
APPARENT TEMPERATURE. ISODROSOTHERMS ANALYSIS REVEALS SOMEWHAT
COOLER VALUES ACROSS NEW ENGLAND AND TRAJECTORIES SUGGEST THESE
LOWER VALUES SHOULD MIGRATE INTO OUR CWFA. IF THIS REMAINS ON
TRACK...THEN HEAT INDICES SHOULD REMAIN JUST BELOW ADVISORY
CRITERIA. HOWEVER...IT WILL BE CLOSE AND PER COLLABORATION WITH
OKX...WE WILL RETAIN THE HEAT ADVISORIES FOR EASTERN ULSTER...ALL
OF DUTCHESS AND LITCHFIELD COUNTIES.
THE UPPER HIGH CONTINUES TO SLOWLY RETROGRADE FURTHER WEST BUT
KEEP OUR WEATHER TRANQUIL. MOS NUMBERS ARE FAIRLY REASONABLE WITH
MAINLY 60S FOR THE OVERNIGHT LOWS AND A MODEL BLEND WAS UTILIZED
WITH A LITTLE MORE EMPHASIS TOWARD THE MET NUMBERS. WE COULD GET
ADDITIONAL PATCHY FOG DEVELOPMENT WHERE DEWPOINT DEPRESSIONS
COLLAPSE WITH LIGHT WINDS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
AS THE LARGE UPPER HIGH CONTINUES TO SLOWLY RETROGRADE...THIS WILL
ALLOW FOR A GRADUAL HEIGHT FALLS ACROSS THE CWFA AND AN INCREASING
NORTHWEST FLOW. PER CLIMATOLOGY...THESE NORTHWEST FLOWS UNDER A
VERY WARM/HOT AND MOIST AIR MASS COULD POSE A CHALLENGE WITH
CONVECTIVE FORECASTS. LATEST MODELS SEEM TO SUGGEST THIS WITH SOME
QPF EXPECTED IN THE AFTERNOON AND EVENING ACROSS THE HIGHER
TERRAIN MAINLY TO THE NORTH AND EAST OF THE CAPITAL DISTRICT. ANY
SUBTLE SHORT WAVE ON TOP OF FORECAST SBCAPES OF 1-2K J/KG COULD
ALLOW PARCELS TO BYPASS THE CAP AOA H700 FOR ISOLATED CONVECTION
TO DEVELOP. AS PER THE PREVIOUS EXCELLENT FORECAST...WE WILL
RETAIN THE SLIGHT CHANCE POPS. HIGHS ON TUESDAY ARE EXPECTED TO BE
SIMILAR TO MONDAY/S BUT THE DEWPOINTS ARE EXPECTED TO BE A LITTLE
HIGHER. THIS MAY POSE ANOTHER OPPORTUNITY FOR HEAT ADVISORIES FOR
VALLEY LOCATIONS MAINLY SOUTH OF ALBANY.
ANY CONVECTION SHOULD QUICKLY DISSIPATE TUESDAY EVENING WITH THE
LOSS OF DAYTIME HEATING. IT WILL BE ANOTHER WARM AND MUGGY NIGHT
FOR THE REGION WITH MAINLY 60S FOR OVERNIGHT LOWS /AROUND 70F IN
THE VICINITY OF THE HUDSON RIVER SOUTH OF KGFL.
WEDNESDAY...THE NAM AND ECMWF ARE VERY SIMILAR WITH AN INJECTION
OF MUCH DRIER AIR AOB H500. WITH THAT WRITTEN...SBCAPES ARE
EXPECTED TO BE CLIMB AT OR ABOVE 2K J/KG WITH THE GFS MORE ROBUST
WITH CONVECTIVE DEVELOPMENTS IN THE AFTERNOON AND TOWARD SUNSET.
A CLOSER LOOK AT 1.5PVU SURFACE...ITS DIFFICULT TO FIND AN ANOMALY
TO RESULT IN THE GFS QPF FORECAST. BUT THE SURFACE FEATURES DO
HINT A WEAK TROUGH AXIS SLIDING THROUGH WITH A WIND SHIFT FROM THE
WESTERLY DIRECTION. FOR NOW...WE WILL RETAIN THE PREVIOUS
FORECAST FOR KEEPING POPS JUST BELOW SLIGHT CHANCE. HIGHS
WEDNESDAY AFTERNOON COULD CLIMB INTO THE MIDDLE 90S AS LOW LEVEL
FLOW BECOMES MORE WESTERLY AND A SLIGHT INCREASE IN THE H825
TEMPS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
DURING THIS PERIOD WE WILL BEGIN TO SEE A SLOW BREAKDOWN IN THE HEAT
WAVE ALTHOUGH FROM THIS VANTAGE POINT.
WE KEEP IT DRY (14 POPS) WEDNESDAY NIGHT BUT STILL MUGGY WITH
OVERNIGHT LOWS WITHIN A FEW DEGREES OF 70.
THEN...ON THURSDAY INTO FRIDAY...AS 500MB HEIGHT FALLS COMMENCE...AT
THE SURFACE...A COLD FRONT LOOK TO SLOWLY SINK SOUTHWARD FROM
CANADA. ALTHOUGH IT MIGHT STILL BE LOCATED JUST TO THE NORTH OF OUR
REGION...IT WILL SERVE TO BEGIN TO BREAK THE "CAP" IN
ATMOSPHERE...ESPECIALLY NORTH. ON THURSDAY AND FRIDAY WE INCLUDE
POPS FOR SHOWERS/THUNDERSTORMS (30 POPS FAR NORTH) ONLY 20 POPS
FURTHER SOUTH. IT WILL STILL BE HOT AND HUMID WITH TEMPERATURES
REACHING 90-95 IN VALLEY AREAS...MID TO UPPER 80S ACROSS THE HIGHER
TERRAIN. HEAT INDICES WILL REACH 95 TO 100 IN THE VALLEY AREAS
AGAIN...CONTINUING THE HEAT WAVE.
AS WE HEAD INTO THE WEEKEND...INDICATIONS ARE A SECOND STRONGER COLD
FRONT COULD FOLLOW ON THE HEELS OF THE FIRST ONE...BUT THE EXACT
TIMING IS IMPOSSIBLE TO DETERMINE THIS FALL OUT. THIS FRONT COULD
BRING PERHAPS A MORE SIGNIFICANT ROUND OF THUNDERSTORMS...ESPECIALLY
IF ARRIVES LATER SATURDAY DURING THE HEATING OF THE DAY. IT IS TOO
EARLY TO FULLY ASSESS THE SEVERE POTENTIAL OF THE THUNDERSTORMS.
THERE SHOULD BE PLENTY OF INSTABILITY OF A 1000 J/KG EACH OF THESE
DAYS TO WORK WITH. THE WIND FIELD WILL INCREASE SOMEWHAT THROUGH THE
PERIOD.
WITH MORE CLOUDS ANTICIPATED SATURDAY...HIGH TEMPERATURES WILL BE
MORE LIKE 85 TO 90 IN THE VALLEYS...WITH A FEW DEGREES OF 80 IN THE
MOUNTAINS. FINALLY...BY SUNDAY WITH RAIN OR SHINE...HIGH
TEMPERATURES LOOKS TO COOL OFF EVEN MORE...80 TO 85 IN THE
VALLEYS...ONLY 70S HIGHER TERRAIN. DEWPOINTS LOOK TO DROP INTO THE
50S.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL REMAIN IN ALL LEVELS OF THE ATMOSPHERE FOR THE
NEXT SEVERAL DAYS.
VFR CONDITIONS SHOULD PREVAIL AT KPOU AND KALB THROUGH THE DAY.
THERE HAS BEEN IFR FOG AT BOTH KPSF AND KGFL...BUT SOME MID LEVEL
CLOUDS HAVE MOVED IN AND HELPED THIN THE FOG. HOWEVER...WILL
CONTINUE WITH OCCASIONAL IFR FOG AT BOTH TAF SITES THROUGH 12Z.
ANY AND ALL FOG WILL DISSIPATE AROUND THE MORNING PEAK AT KPSF AND
KGFL (12Z). AFTER THAT VFR CONDITIONS WILL PREVAIL EVERYWHERE. A
NORTHWEST OR WEST WIND WILL INCREASE TO 5-10KTS...WITH PERHAPS A FEW
HIGHER GUSTS AT KPSF AND KALB NOT INCLUDED IN THE TAF AT THIS TIME.
THERE MIGHT BE A FEW CUMULUS WITH BASED AROUND 6000 FEET LATER BY
AFTERNOON.
MONDAY NIGHT...MAINLY VFR CONDITIONS EXPECTED DURING THE EVENING BUT
IFR FOG MIGHT ENSUE AGAIN AT KGFL AND KPSF AFTER MIDNIGHT. THE WIND
WILL BE LIGHT OR CALM.
WE ARE STARTING A NEW EXPERIMENTAL FORMAT FOR DISPLAYING THE
EXTENDED PORTION OF THE AVIATION DISCUSSION. THIS FORMAT BREAKS THE
EXTENDED PERIODS INTO 12-HOUR INCREMENTS. IT DOES NOT INCLUDE THE
POSSIBILITY OF IFR/VFR BUT THE POTENTIAL SENSIBLE WEATHER AND
"POTENTIAL" IMPACT THE WEATHER MIGHT CAUSE. WE HAVE OMITTED THE WORD
POTENTIAL TO KEEP THE VERBIAGE SHORTER.
OUTLOOK...
TUESDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO
SIGNIFICANT WEATHER.
THURSDAY: MODERATE OPERATIONAL IMPACT. SLIGHT CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF RAIN
SHOWERS...THUNDER STORMS.
&&
.FIRE WEATHER...
SIGNIFICANT RAINFALL THAT HAS OCCURRED OVER THE PAST SEVERAL
WEEKS...THERE CONTINUES TO BE NO FIRE WEATHER RELATED CONCERNS. A
FULL RECOVERY IN LOW LEVEL MOISTURE ARE EXPECTED EACH NIGHT AND RH
VALUES WILL REMAIN ELEVATED DURING THE AFTERNOON...DROPPING TO
BETWEEN 40 AND 60 PERCENT.
THE BERMUDA HIGH...AT THE SURFACE AND ALOFT...WILL DOMINATE OVER
THE EASTERN UNITED STATES RESULTING IN A WEEK WITH HOT AND HUMID
CONDITIONS. TOWARDS THE END OF THE WEEK THERE WILL BE A CHANCE OF
SHOWERS AND THUNDERSTORMS AS A FRONTAL BOUNDARY APPROACHES THE
REGION.
&&
.HYDROLOGY...
LITTLE IN THE WAY OF PRECIPITATION IS EXPECTED THROUGH MID WEEK.
LOOKING AT HOT AND HUMID WEATHER AS HIGH PRESSURE DOMINATES THE
REGION. THE OVERALL TREND FOR MAIN STEM RIVERS WILL BE FOR FLOWS TO
CONTINUE TO DECREASE. THE NEXT CHANCE OF MEASURABLE RAIN FOR MOST
AREAS WILL BE TOWARDS THE END OF THE WEEK AS A FRONTAL BOUNDARY
APPROACHES AND MOVES INTO THE REGION.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
TO ACCESS HEAT RELATED CLIMATE DATA INCLUDING HEAT WAVES...NUMBER
90+ DEGREES DAYS AND 100+ DEGREES DAYS...PLEASE VISIT
WWW.WEATHER.GOV/ALY/SPECIALDATAALB /ALL LOWER CASE/
NUMBER OF 90+ DEGREE DAYS AND RECORD HIGHS...
ALBANY NY...
2013 MAY: 1 DAY
2013 JUNE: 4 DAYS
2013 JULY: 3 DAYS
2012: 13 DAYS
2011: 8 DAYS
2010: 14 DAYS
NORMAL: 10 DAYS
RECORD HIGHS: (DATE BACK TO 1874)
JULY 14: 99 DEGREES 1995
JULY 15: 96 DEGREES 1997
JULY 16: 97 DEGREES 1900
JULY 17: 99 DEGREES 1900
JULY 18: 100 DEGREES 1953
JULY 19: 97 DEGREES 1904
GLENS FALLS NY...
2013 MAY: 1 DAY
2013 JUNE: 2 DAYS
2013 JULY: 1 DAY
2012: 8 DAYS
RECORD HIGHS: (DATE BACK TO 1949)
JULY 14: 98 DEGREES 1995
JULY 15: 94 DEGREES 1983
JULY 16: 95 DEGREES 1983
JULY 17: 99 DEGREES 1953
JULY 18: 97 DEGREES 1953
JULY 19: 95 DEGREES 1977
POUGHKEEPSIE NY...
2013 MAY: 3 DAY
2013 JUNE: 4 DAYS
2013 JULY: 4 DAYS
2012: 22 DAYS
RECORD HIGHS: (DATE BACK TO 1949)
JULY 14: 99 DEGREES 1954
JULY 15: 98 DEGREES 1995
JULY 16: 103 DEGREES 1995
JULY 17: 98 DEGREES 2006
JULY 18: 100 DEGREES 1991
JULY 19: 102 DEGREES 1991
BENNINGTON VT...
2013 MAY: NONE
2013 JUNE: NONE
2013 JULY: 1 DAY
2012: 7 DAYS
PITTSFIELD MA...
2013 MAY: NONE
2013 JUNE: NONE
2013 JULY: NONE
2012: 3 DAYS
&&
.EQUIPMENT...
KENX NATIONAL WEATHER SERVICE DOPPLER RADAR WILL BE UNAVAILABLE
THROUGH TUESDAY JULY 16 2013. TECHNICIANS CONTINUE TO TROUBLESHOOT
WITH PARTS ON ORDER AT THIS TIME. WE EXPECT A FULL RETURN TO
SERVICE LATE TUESDAY AFTERNOON. WE APOLOGIZE FOR THE INCONVENIENCE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
CTZ001-013.
NY...HEAT ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
NYZ064>066.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...HWJIV
AVIATION...HWJIV
FIRE WEATHER...IAA/BGM
HYDROLOGY...IAA/BGM
CLIMATE...IAA
EQUIPMENT...IAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1102 AM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
//PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CONTINUE TO WATCH FOR POSSIBLE CONVECTIVE DEVELOPMENT. SMALL
CELLS FORMING WELL SOUTHWEST OF THE TERMINALS ARE MOVING
NORTHEAST. MOST FAVORABLE TIMEFRAME FOR ORD/MDW WOULD BE 18-21Z.
LENNING
//DISCUSSION...UPDATED 12Z...
THE LARGE ANTICYCLONE...SURFACE THROUGH THE UPPER LEVELS...WILL
CONTINUE TO RETROGRADE WESTWARD OVER THE REGION WITH IT BEING
CENTERED OVER OH DURING THE DAY. MEANWHILE THE UPPER LOW IN THE
SOUTHERN PLAINS...CURRENTLY CENTERED OVER THE RED RIVER VALLEY...
WILL ALSO RETROGRADE SLOWLY WESTWARD TO THE TX PANHANDLE DURING
THE DAY.
WITHIN THE SOUTHEASTERLY FLOW BETWEEN THESE TWO MAIN FEATURES
SATELLITE LOOPS SHOW MULTIPLE SMALL DISTURBANCES THAT HAVE BEEN
MOVING FROM THE DEEP SOUTH ACROSS THE LOWER OH VALLEY AND MID MS
VALLEY FROM SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS.
MODELS...EVEN HI RES ONES...ARE TYPICALLY NOT VERY GOOD
POSITIONING THESE SMALLER DISTURBANCES BEYOND THE NEAR TERM SO
HAVE RELIED MORE ON OLD SCHOOL EXTRAPOLATION TO CONTINUE MOVING
THEM NORTHWEST TO NORTH-NORTHWESTWARD TODAY.
THIS METHOD HAS ONE DISTURBANCE MOVING OVER THE AREA DURING THE
PRE-DAWN AND EARLY MORNING HOURS WITH ANOTHER DURING THE EARLY
AND MID AFTERNOON. WHILE DIURNAL HEATING WILL RESULT IN A CU
FIELD TO DEVELOP BY LATE MORNING TO NOONTIME...THESE DISTURBANCES
WILL START MOVING ANTICYCLONICALLY AS THEY ROTATE THROUGH THE
EAST SIDE OF THE UPPER HIGH. WITHOUT THE AID OF DAYTIME HEATING
AND WITH NORTHWEST MOVEMENT FROM SLIGHTLY CYCLONIC UPPER FLOW TO
NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW THE FEW TS THAT DEVELOPED
IN SOUTHERN INDIANA SUNDAY EVENING ASSOCIATED WITH THE NORTHERN
MOST IMPULSE DISSIPATED BY 06Z.
WHILE CANNOT TOTALLY RULE OUT AN ISOLATED TS OR TWO WITH THESE
DISTURBANCES THE PROBABILITY OF OCCURRENCE LET ALONG AFFECTING
ORD OR MDW AND VICINITY IS SLIGHT AT BEST.
WITH THE CENTER OF THE ANTICYCLONE CREEPING WESTWARD AND THE LOW
LEVEL FLOW...WEAK AS IT WILL BE...VEERING TO SE TODAY AND THEN
TO S TO SW THE OVERNIGHT THE DEW POINTS OF AROUND 70 JUST TO THE
E THROUGH SW OF THE LOCAL AREA WILL OVERSPREAD THE AREA. WITH
LIGHT TO NIL WIND OVERNIGHT TONIGHT THROUGH DAWN TUE AND SURFACE
COOLING DURING THIS TIME WILL RESULT IN A SHALLOW SURFACE BASED
INVERSION FORMING WHICH WILL CONDUCIVE TO BR AND HZ UNTIL IT
MIXES OUT AFTER SUNRISE TUE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* LOW CONFIDENCE ON TIMING AND LOCATION OF SHRA AND TSRA...SO
STILL OPTING TO EXCLUDE FROM LATEST TAF AMENDMENT.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.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 LINCOLN IL
1052 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 1047 AM CDT MON JUL 15 2013
WITH MOISTURE INCREASING FROM YESTERDAY WITH SOME SCT SPRINKLES
AND PRETTY EXPANSIVE CU FIELD...SAT IMAGERY IS ON TRACK WITH MORE
CLOUD COVER FOR THIS AFTERNOON AS WELL. SOME OF THE CU GETTING A
BIT TALL WITH SOME SHOWERS POPPING UP NORTH OF CWA. EARLY CU FIELD
IN THE FAR SE HEADED THE SAME WAY. WITH PLENTY OF MUGGY AIR TO
WORK WITH IN THE COLUMN FROM THIS MORNINGS SOUNDING...AND A
SHORTWAVE RIPPLING THROUGH THE CWA...THINK A SLIGHT UPWARD ADJUSTMENT
IN THE POPS MAY BE WARRANTED. CONCERN FOR GOING TOO HIGH OR
WIDESPREAD WITH REGARDS TO THE LOCATION OF THE BEST LIFT WITH THE
SMALL WAVE BY THE TIME PEAK HEATING HITS THIS AFTERNOON. WITH
RATHER NON EXISTENT CAP...SHOULD NOT TAKE MUCH. HAVE BOOSTED FOR
AT LEAST A MENTION TO THE SE FOR SOME ISO SHOWERS...THOUGH SHOULD
BE WELL BEHIND THE WAVE BY THIS AFTERNOON.
HJS
&&
.AVIATION...
ISSUED 610 AM CDT MON JUL 15 2013
OTHER THAN SOME PATCHY GROUND FOG EARLY THIS MORNING (UNTIL 13Z)
AND AGAIN AFTR 09Z TONIGHT AT A FEW OF OUR TAF SITES...VFR
CONDITIONS ARE EXPECTED. LATEST FORECAST SOUNDINGS CONTINUE TO
SHOW THE POTENTIAL FOR RAPID CUMULUS DEVELOPMENT AROUND 15 TO 16Z
MOST AREAS WITH SCT-BKN CIGS EXPECTED AT OR JUST AFTR 18Z.
ATMOSPHERE BECOMES RATHER UNSTABLE BY EARLY THIS AFTN BUT COVERAGE
OF ANY CONVECTION THE FORMS IN THE HEAT OF THE DAY TOO SPOTTY TO
INCLUDE IN ANY OF THE TAFS THIS FORECAST PERIOD. CU FIELD SHOULD
QUICKLY DISSIPATE AGAIN THIS EVENING WITH MAINLY HIGH LEVEL CLOUDS
EXPECTED OVERNIGHT. ANOTHER DAY WITH LIGHT SURFACE WINDS WITH
MAINLY ESE WINDS EXPECTED AT 10 KTS OR LESS TODAY...AND FROM 5 TO
10 KTS TONIGHT. MAY SEE A BRIEF PERIOD OF GROUND FOG AGAIN LATE
TONIGHT...AFTER 10Z...BUT COVERAGE STILL APPEARS LIMITED ENOUGH
TO KEEP OUT OF THIS SET OF TAFS.
SMITH
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
925 AM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
&&
.PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* VARIABLE WIND DIRECTION POSSIBLE BUT LIGHT FLOW GENERALLY EASTERLY.
* TSRA THIS AFTERNOON NOT OUT OF THE QUESTION. NOT EXPECTING
WIDESPREAD OR LONG LIVED ACTIVITY...BUT SOME STORMS EASILY COULD
WORK THEIR WAY INTO THE TERMINAL AREAS. ALSO THE UNUSUAL
MOVEMENT FROM SOUTHEAST TO NORTHWEST COULD ADD TO THE CONFUSION.
LENNING
//DISCUSSION...UPDATED 12Z...
THE LARGE ANTICYCLONE...SURFACE THROUGH THE UPPER LEVELS...WILL
CONTINUE TO RETROGRADE WESTWARD OVER THE REGION WITH IT BEING
CENTERED OVER OH DURING THE DAY. MEANWHILE THE UPPER LOW IN THE
SOUTHERN PLAINS...CURRENTLY CENTERED OVER THE RED RIVER VALLEY...
WILL ALSO RETROGRADE SLOWLY WESTWARD TO THE TX PANHANDLE DURING
THE DAY.
WITHIN THE SOUTHEASTERLY FLOW BETWEEN THESE TWO MAIN FEATURES
SATELLITE LOOPS SHOW MULTIPLE SMALL DISTURBANCES THAT HAVE BEEN
MOVING FROM THE DEEP SOUTH ACROSS THE LOWER OH VALLEY AND MID MS
VALLEY FROM SUNDAY AFTERNOON THROUGH THE OVERNIGHT HOURS.
MODELS...EVEN HI RES ONES...ARE TYPICALLY NOT VERY GOOD
POSITIONING THESE SMALLER DISTURBANCES BEYOND THE NEAR TERM SO
HAVE RELIED MORE ON OLD SCHOOL EXTRAPOLATION TO CONTINUE MOVING
THEM NORTHWEST TO NORTH-NORTHWESTWARD TODAY.
THIS METHOD HAS ONE DISTURBANCE MOVING OVER THE AREA DURING THE
PRE-DAWN AND EARLY MORNING HOURS WITH ANOTHER DURING THE EARLY
AND MID AFTERNOON. WHILE DIURNAL HEATING WILL RESULT IN A CU
FIELD TO DEVELOP BY LATE MORNING TO NOONTIME...THESE DISTURBANCES
WILL START MOVING ANTICYCLONICALLY AS THEY ROTATE THROUGH THE
EAST SIDE OF THE UPPER HIGH. WITHOUT THE AID OF DAYTIME HEATING
AND WITH NORTHWEST MOVEMENT FROM SLIGHTLY CYCLONIC UPPER FLOW TO
NEUTRAL TO SLIGHTLY ANTICYCLONIC FLOW THE FEW TS THAT DEVELOPED
IN SOUTHERN INDIANA SUNDAY EVENING ASSOCIATED WITH THE NORTHERN
MOST IMPULSE DISSIPATED BY 06Z.
WHILE CANNOT TOTALLY RULE OUT AN ISOLATED TS OR TWO WITH THESE
DISTURBANCES THE PROBABILITY OF OCCURRENCE LET ALONG AFFECTING
ORD OR MDW AND VICINITY IS SLIGHT AT BEST.
WITH THE CENTER OF THE ANTICYCLONE CREEPING WESTWARD AND THE LOW
LEVEL FLOW...WEAK AS IT WILL BE...VEERING TO SE TODAY AND THEN
TO S TO SW THE OVERNIGHT THE DEW POINTS OF AROUND 70 JUST TO THE
E THROUGH SW OF THE LOCAL AREA WILL OVERSPREAD THE AREA. WITH
LIGHT TO NIL WIND OVERNIGHT TONIGHT THROUGH DAWN TUE AND SURFACE
COOLING DURING THIS TIME WILL RESULT IN A SHALLOW SURFACE BASED
INVERSION FORMING WHICH WILL CONDUCIVE TO BR AND HZ UNTIL IT
MIXES OUT AFTER SUNRISE TUE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* HIGH CONFIDENCE OF GENERALLY EASTERLY FLOW TODAY...GRADUALLY
BACKING SOUTHEAST TO SOUTH.
* CONFIDENCE OF TIMING...LOCATION...AND PROBABILITY OF CONVECTION
IS TOO LOW FOR INCLUSION IN TAFS JUST YET.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
617 AM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.AVIATION...
ISSUED 610 AM CDT MON JUL 15 2013
OTHER THAN SOME PATCHY GROUND FOG EARLY THIS MORNING (UNTIL 13Z)
AND AGAIN AFTR 09Z TONIGHT AT A FEW OF OUR TAF SITES...VFR
CONDITIONS ARE EXPECTED. LATEST FORECAST SOUNDINGS CONTINUE TO
SHOW THE POTENTIAL FOR RAPID CUMULUS DEVELOPMENT AROUND 15 TO 16Z
MOST AREAS WITH SCT-BKN CIGS EXPECTED AT OR JUST AFTR 18Z.
ATMOSPHERE BECOMES RATHER UNSTABLE BY EARLY THIS AFTN BUT COVERAGE
OF ANY CONVECTION THE FORMS IN THE HEAT OF THE DAY TOO SPOTTY TO
INCLUDE IN ANY OF THE TAFS THIS FORECAST PERIOD. CU FIELD SHOULD
QUICKLY DISSIPATE AGAIN THIS EVENING WITH MAINLY HIGH LEVEL CLOUDS
EXPECTED OVERNIGHT. ANOTHER DAY WITH LIGHT SURFACE WINDS WITH
MAINLY ESE WINDS EXPECTED AT 10 KTS OR LESS TODAY...AND FROM 5 TO
10 KTS TONIGHT. MAY SEE A BRIEF PERIOD OF GROUND FOG AGAIN LATE
TONIGHT...AFTER 10Z...BUT COVERAGE STILL APPEARS LIMITED ENOUGH
TO KEEP OUT OF THIS SET OF TAFS.
SMITH
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
705 AM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM EDT MON JUL 15 2013
EXCEPT FOR SOME FOG EARLY AT IWD...EXPECT VFR CONDITIONS TO DOMINATE
THIS FCST PERIOD AS HI PRES REMAINS IN CONTROL. THERE WL BE AN
INFLUX OF MOISTER AIR...BUT PERSISTENT UPR RDG WL RESTRICT THE CHC
FOR SHRA TDAY. SOME FOG IS PSBL TNGT WITHIN THE MOISTER AIRMASS...
BUT A STEADY S WIND WL LIMIT THIS POTENTIAL.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
651 AM CDT MON JUL 15 2013
.AVIATION...
12Z TAFS FOR KOMA...KLNK...KOFK.
INCREASING AREA OF MID CLOUDS APPROACHING AREA FROM THE SOUTHEAST
AT 11Z WILL LIKELY CONTINUE INTO THE DAY WITH SCT-BKN LAYERS
EXPECTED AT TAF SITES. SCT CU LAYER ALSO POSSIBLE AFTER 16Z.
PATCHY MVFR VSBY AFTER 09Z WITH WEAK SURFACE FLOW STILL IN PLACE.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON JUL 15 2013/
DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
623 AM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 622 AM CDT MON JUL 15 2013
FOR THE KLBF TERMINAL...PATCHY GROUND FOG WITH VISBYS DOWN TO HALF
A MILE OR LESS WILL REMAIN POSSIBLE THROUGH 13Z. FOG IS EXPECTED TO
BURN OFF BY MID MORNING WITH CLEAR SKIES EXPECTED THEREAFTER.
WINDS WILL BE SOUTHERLY AT 10 TO 20 KTS TODAY...DIMINISHING TO
UNDER 10 KTS TONIGHT.
FOR THE KVTN TERMINAL...SCATTERED TO BROKEN CIGS AON 2000 FT AGL
ARE EXPECTED THROUGH MID MORNING...WITH MOSTLY CLEAR SKIES
EXPECTED THEREAFTER. SOUTHERLY WINDS WILL INCREASE TO 10 TO 20
KTS...WITH GUSTS TO 25 KTS POSSIBLE THIS AFTERNOON. WINDS WILL
DIMINISH TO 10 TO 15 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...CLB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1031 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
TWEAKED THE POPS...AND DI GAMBLE ON REMOVING SOME OF THE SLIGHT
CHANCE POPS TODAY ACROSS THE NORTHWESTERN ZONES. OTHERWISE...NO
MAJOR CHANGES. HEAT AND HUMIDITY WILL BE PLENTIFUL TODAY.
PREVIOUS DISCUSSION...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE AND LIGHT WINDS WILL DOMINATE THE WEATHER. AFTER SOME
EARLY MORNING VALLEY FOG BURNS OFF...VFR CONDITIONS WILL GENERALLY
PREVAIL...ALTHOUGH A COUPLE OF AFTERNOON THUNDERSTORMS CREATING
RESTRICTIONS CAN NOT BE RULED OUT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...LOCATION OF THUNDERSTORMS
THIS AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY H H M H H H H H H H H H
HTS CONSISTENCY H H M H H H H H H H H H
BKW CONSISTENCY H H M M H H H H H H H H
EKN CONSISTENCY H H M H H H H H H H H H
PKB CONSISTENCY H H M H H H H H H H H H
CKB CONSISTENCY H H M H H H H H H H H H
AFTER 12Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
602 AM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE AND LIGHT WINDS WILL DOMINATE THE WEATHER. AFTER SOME
EARLY MORNING VALLEY FOG BURNS OFF...VFR CONDITIONS WILL GENERALLY
PREVAIL...ALTHOUGH A COUPLE OF AFTERNOON THUNDERSTORMS CREATING
RESTRICTIONS CAN NOT BE RULED OUT.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...LOCATION OF THUNDERSTORMS
THIS AFTERNOON COULD VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 07/15/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EDT 1HRLY 04 05 06 07 08 09 10 11 12 13 14 15
CRW CONSISTENCY H H H H H H H H M H H H
HTS CONSISTENCY H H H H H H H H M H H H
BKW CONSISTENCY H H H H H H H H M M H H
EKN CONSISTENCY M M H H H H H H M H H H
PKB CONSISTENCY H H H H H H H H M H H H
CKB CONSISTENCY H H H H H H H H M H H H
AFTER 12Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY
SHORT TERM...30
LONG TERM...TRM
AVIATION...RPY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1041 AM CDT MON JUL 15 2013
.UPDATE...
MORNING FORECAST UPDATE.
&&
.DISCUSSION...
AREA RADAR SHOWING A BROAD SHIELD OF PRECIP OVER C TX INTO THE
BRAZOS VALLEY. WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS
NOW OVER SE TX AND ALONG THE UPPER TX COAST SHOULD CONTINUE TO
MOVE INLAND. THERE SEEMS TO BE A TREND IN THE SHOWER AND
THUNDERSTORM ACTIVITY DECREASING IN COVERAGE. THIS LOOKS TO BE
SUPPORTED BY LATEST HRRR MODEL RUNS WHICH ALSO SHOW MORE ACTIVITY
DEVELOPING DURING THE EARLY AFTERNOON. THINK IF THIS LULL IN
ACTIVITY DOES OCCUR AND CLOUD COVER LESSENS...MAY GET MORE HEATING
TO INITIATE ANOTHER ROUND OF STORMS THIS AFTERNOON. AS SUCH THINK
HOLDING ONTO 50/60 POPS THIS AFTERNOON LOOKS ON TRACK. MAX TEMP
FORECAST WILL BE TRICKY AS MOST INLAND AREAS ARE STILL IN THE 70S
AND MAY BE HARD PRESSED TO REACH THE LOW/MID 80S. GETTING SOME LOW
80S ALONG THE COAST WHERE CLOUDS ARE LESS SO FOR NOW THINK MAX
TEMPS FORECAST IS OKAY BUT LARGELY DEPENDS ON CLOUD COVER. IT
CERTAINLY WILL NOT GET ANY WARMER. UPDATED FORECAST HAS BEEN SENT.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 50 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
710 AM CDT MON JUL 15 2013
.AVIATION...
MANY FACTORS COMING TOGETHER THIS MORNING IN SUPPORTING THIS
RECENTLY MORE-ACTIVE WET PATTERN. RADAR DETECTING PRIMARILY
SHOWERS MOVING NORTH AT 20 MPH TOWARDS A NORTHERN COUNTY -RA
SHIELD. SHOWERS WITH ISOLATED STORMS AFFECTING APPROXIMATELY 60
PERCENT OF THE FORECAST AREA. ALL TERMINALS IN THE FORECAST AREA
WILL BE AFFECTED BY NORTHERN-PASSING CONVECTION THROUGH THE
AFTERNOON. A WESTWARD DRIFTING UPPER LOW WITH AN ASSOCIATED
CENTRAL TEXAS SURFACE LOW/STATIONARY BOUNDARY PROVIDING THIS
DECENT INFLOW OF DEEPER GULF MOISTURE OVER AN UNCAPPED ENVIRONMENT.
VCSH OR VCTS...WITH PERIODS OF SHRA OR TSRA...THROUGH AT LEAST
MID-DAY...AN EVENING BREAK WITH LINGERING A MID-HIGH LEVEL BKN-OVC
DECK. ANOTHER WEAK DISTURBANCE MOVING ONSHORE THIS TIME TOMORROW
MORNING...WITH DECENT LAND-SEA SPEED CONVERGENCE...MAY INITIATE
RETURN (NEAR) COASTAL PRECIPITATION. 31
&&
.PREV DISCUSSION... /ISSUED 427 AM CDT MON JUL 15 2013/
DISCUSSION...
THE UPPER LEVEL LOW IS CURRENTLY LOCATED OVER CENTRAL OKLAHOMA
THIS MORNING AS HAS BEEN FORECASTED THE LAST COUPLE OF DAYS.
RAINFALL HAS BEEN FALLING THIS MORNING MAINLY FROM A BRENHAM TO
HUNTSVILLE TO CROCKETT LINE. CURRENT HRRR MODEL RUNS SHOW THE
PRECIP FIELD ASSOCIATED WITH THE UPPER LOW MOVING OFF TO THE WEST
AS THE DAY PROGESSES BUT ALSO HINTS AT REDEVELOPMENT AS MOISTURE
POOLS INTO SOUTHEAST TEXAS. THE EXTENT OF REDEVELOPMENT WILL BE
DEPENDENT ON THE POSITION OF THE UPPER LEVEL LOW. IF THE LOW IS
FAR ENOUGH WEST HIGH PWAT AIR WILL MOVE INTO SOUTHEAST TEXAS. IF
THE LOW IS SLIGHTLY SLOWER THE DEEPER MOISTURE WILL BE PUSHED MORE
INTO THE LAKE CHARLES AREA. GIVEN THAT REDEVELOPMENT IS ALREADY
OCCURRING SEEMS LIKE TODAY WE SHOULD SEE GOOD COVERAGE.
BY LATE MONDAY THE LOW WILL CONTINUE PUSHING TO THE WEST ALLOWING
FOR DEEP TROPICAL MOISTURE TO REMAIN IN PLACE. THIS IN COMBINATION
WITH NO REAL LARGE SCALE SUBSIDENCE IN PLACE WILL ALLOW FOR RAIN
CHANCES TO CONTINUE THROUGH THE WORK WEEK. BY THURSDAY THE GFS
HAS SLIGHTLY DRIER AIR (~1.6" PWAT) MOVING IN WHICH COULD HINDER
SOME PRECIP DEVELOPMENT. THE NAM ON THE OTHER HAND STILL HAS PWAT
VALUES AROUND 1.9" EARLY THURSDAY. THE GFS...EUROPEAN AND CANADIAN
ARE ALL SIMILAR WITH KEEPING THE UPPER LEVEL RIDGE OFF TOWARDS THE
NORTH FOR THE SECOND PART OF THIS WEEK. THE RIDGE IS THEN EXPECTED
TO ERODE NEXT WEEKEND. 23
MARINE...
AS WEAK DISTURBANCES/EASTERLY GULF WAVES COME ASHORE THROUGH
TUESDAY...MARINERS WILL EXPERIENCE PERIODS OF RAIN SHOWERS WITH
EMBEDDED STORMS. U.S. PLAINS HIGH PRESSURE IN RELATION TO LOWER
MEXICO PRESSURE WILL MAINTAIN A TIGHT ENOUGH COASTAL GRADIENT IN
SUPPORTING MODERATE ONSHORE WINDS THROUGH TUESDAY. THIS ENHANCED
SOUTHEASTERLY FETCH WILL DRAW UP A SOUTHWESTERN GULF SWELL LATE
TUESDAY INTO EARLY WEDNESDAY THAT WILL ULTIMATELY INCREASE SEA
HEIGHTS BY A COUPLE OF FEET (UPON TODAY`S HEIGHTS). MID TO LATE WEEK
EAST TO SOUTHEASTERLY FLOW WILL TAME...LOWERING SEA HEIGHTS. AS
BERMUDA-BASED SURFACE HIGH PRESSURE EXPANDS WESTWARD...THE ONSHORE
GRADIENT WILL TIGHTEN UP ONCE AGAIN OVER THE WEEKEND THAT EQUATES TO
STRENGTHENING SOUTHEASTERLY WINDS AND RETURN OFFSHORE SWELL. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 85 72 90 72 90 / 80 40 40 30 40
HOUSTON (IAH) 87 74 90 74 90 / 60 40 50 30 40
GALVESTON (GLS) 88 79 88 79 88 / 50 40 50 30 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 9 AM CDT THIS MORNING
FOR THE FOLLOWING ZONES: MATAGORDA BAY...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20
NM.
&&
$$
DISCUSSION...23
AVIATION/MARINE...31
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
630 AM CDT MON JUL 15 2013
.DISCUSSION...UPDATED FOR 12Z AVIATION.
&&
.AVIATION...MAINLY VFR CONDITIONS CONTINUE THIS MORNING WITH
SCATTERED STRATO CU. A BRIEF MVFR CIG WILL BE POSSIBLE AT TAF
SITES FOR THE NEXT COUPLE OF HOURS. EVERYONE SHOULD INCREASE CLOUD
HEIGHTS THROUGH THE MORNING AND FOR THE AFTERNOON. THUNDERSTORM
CHANCES ARE GREATEST TODAY AROUND THE VCT TAF SITE. OTHER SITES
WILL ALSO HAVE A SLIGHT CHANCE OF SHOWERS AND STORMS...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME. STRATO CU SHOULD RETURN
AGAIN TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 356 AM CDT MON JUL 15 2013/
SHORT TERM (TODAY THROUGH TUESDAY)...ONGOING MCS NORTH OF
FORECAST AREA SHOULD REMAIN MAINLY NORTH TODAY. UPPER LEVEL LOW
SPINNING CURRENTLY LOCATED OVER SOUTHERN OKLAHOMA...WILL CONTINUE
TO PULL BULK OF ENERGY RESPONSIBLE FOR CURRENT MCS TOWARD THE
EAST. HAVE SOME STREAMER ACTIVITY OVER NEARSHORE WATERS AND
COASTAL COUNTIES THIS MORNING...WELL REPRESENTED IN MESO MODEL
GUIDANCE...INDICATIVE OF INCREASING MOISTURE IN THE AREA.
SATELLITE DERIVED PW SAMPLES INDICATE WE ARE APPROACHING 2 INCH
PWAT ACROSS THE AREA. WILL SEE IF SOUNDING THIS AM CAN CONFIRM
THAT.
BEST MOISTURE TODAY STILL EXPECTED TO BE IN NORTHEAST PORTION OF
CWA...AND WOULD EXPECT BEST CHANCES FOR AFTERNOON CONVECTION TO BE
IN THAT AREA. WITH NO CAP TO SPEAK OF...AND MODERATE CAPE AND
LAPSE RATES THIS AFTERNOON HAVE KEPT A 50 POP WITH THUNDERSTORM
WORDING. DID INCREASE POPS OVER REMAINDER OF NORTHERN FORECAST AREA
AS SOME MESO GUIDANCE...PARTICULARLY THE HRRR INDICATES A BAND OF
SHOWERS DEVELOPING SEPARATE FROM CURRENT MCS AND DRIFTING INTO THE
AREA. THIS BAND IS SHOWING UP ON RADAR AT THIS TIME...BUT DPT
DEPRESSION AT THE SURFACE STILL TOO HIGH FOR RAIN AT THE SURFACE.
IF THIS AREA CAN CONTINUE TO POOL MOISTURE WOULD SEE SOME SHOWERS
NORTH...AND POSSIBLY WEST LATE THIS MORNING OR AFTERNOON.
ADDITIONALLY...GUIDANCE (GLOBAL AND MESO) IN PRETTY GOOD
AGREEMENT IN BRINGING AN MCS THROUGH CENTRAL TEXAS INTO THE RIO
GRANDE VALLEY TONIGHT. MOST GUIDANCE KEEPS THE BULK OF THE PRECIP
NORTH OF THE CWA...JUST SKIMMING LA SALLE AND WEBB COUNTIES. HAVE
INCREASE TO A 40 POP OUT THERE TONIGHT TO ACCOUNT FOR THE
PROXIMITY OF THIS POTENTIAL SYSTEM.
MOVING ON TO TUESDAY...GREATER MOISTURE EXPECTED TO PUSH EAST TO
WEST ACROSS THE AREA DURING THE DAY ON TUESDAY. KEPT PRETTY CLOSE
TO PREVIOUS FORECAST FOR TUESDAY...WITH 40 TO 50 POP ACROSS THE
AREA AS THE UPPER LOW CONTINUES TO RETROGRADE ACROSS NORTH TEXAS.
KEPT TEMPS PRETTY CLOSE TO PREVIOUS FORECAST...THINKING SLIGHTLY
COOLER THAN RECENT DAYS ATTRIBUTED TO INCREASING MOISTURE AND
CLOUD COVER. HIGHS IN THE LOWER TO MID 90S FOR MOST AREAS BOTH
TODAY AND TUESDAY...WITH LOWS TONIGHT IN THE 70S.
LONG TERM (TUESDAY NIGHT THROUGH SUNDAY)...THE INFLUENCE OF THE
UPPER LOW/TROUGH OVER THE CWA WL DIMINISH EARLY IN THE PERIOD
FOLLOWED BY A WEAKNESS IN THE 500MB HEIGHT FIELD OVER THE CWA/MSA
THURSDAY/FRIDAY WITH AN APPROXIMATELY E-W UPPER RIDGE AXIS ACRS THE
CONUS YET NORTH OF THE CWA/MSA (GFS/ECMWF/NAM DETERMINISTIC.) THIS
RIDGE AXIS IS PROGD TO MOVE SWD AND OVER THE CWA/MSA LATE
SATURDAY/SUNDAY (GFS/ECMWF DETERMINISTIC)...YET THE AXIS IS EXPECTED
TO BE WEAK. ALSO DRG THE PERIOD...PERSISTENT ONSHORE FLOW WITH
COPIOUS MSTR/HIGH PWAT VALUES EXPECTED DURING THE PERIOD (GFS
DETERMINISTIC.) THE COMBINATION OF DECREASING UPPER DYNAMICS/MSTR/
INSTABILITY SHOULD RESULT IN SCT CONVECTION WEDNESDAY. THE LACK OF
SIGNIFICANT UPPER FORCING THURSDAY/FRIDAY COMBINED WITH COPIOUS
MSTR SUGGEST DIURNAL CONVECTION MAINLY OVER LAND AND NOCTURNAL
CONVECTION MAINLY OVER THE COASTAL WATERS.
SATURDAY/SUNDAY...ALTHOUGH THE GFS MAINTAINS HIGH PWAT VALUES DRG
THIS PERIOD...ANTICIPATE THAT THE FOREGOING UPPER RIDGE...ALTHOUGH
WEAK...WL DECREASE THE LIKELIHOOD FOR CONVECTION. THUS ANTICIPATE
ONLY ISOLATED CONVECTION. WL FCST LOWER MAX TEMPS THAN GFS MOS
WEDNESDAY-FRIDAY OWING TO EXPECTATION OF EXTREMELY MOIST VERTICAL
COLUMN. ANTICIPATE WARMER MAX TEMPS SATURDAY/SUNDAY CONSIDERING
THE UPPER RIDGE (SLIGHTLY GREATER THICKNESS.)
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 96 77 93 77 88 / 30 30 50 20 40
VICTORIA 94 74 94 73 90 / 50 40 50 20 40
LAREDO 98 78 96 77 93 / 20 30 40 30 50
ALICE 96 75 94 74 90 / 20 30 50 20 40
ROCKPORT 92 78 90 78 87 / 30 40 50 20 40
COTULLA 97 76 96 74 91 / 40 40 50 30 50
KINGSVILLE 97 76 94 76 90 / 20 30 50 20 40
NAVY CORPUS 92 79 90 78 86 / 30 30 50 20 40
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
612 PM EDT MON JUL 15 2013
.SYNOPSIS...
AN OPPRESSIVE HIGH PRESSURE SYSTEM ALONG THE EASTERN SEABOARD IS
EXPECTED TO REMAIN NEARLY STATIONARY THROUGH FRIDAY. A SLOWLY
SOUTHWARD SAGGING COLD FRONT IS FORECAST TO REACH THE NORTHERN
GREAT LAKES ON THURSDAY, LAKE ONTARIO AND LAKE ERIE ON FRIDAY AND
THEN MOVE INTO OUR AREA ON SATURDAY. A SECOND COLD FRONT FROM
EASTERN CANADA IS THEN EXPECTED TO MOVE THROUGH OUR REGION LATER
SUNDAY INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE EXCESSIVE HEAT WARNING REMAINS IN EFFECT. THE HEAT ADVISORY WILL
BE ALLOWED TO EXPIRE AT 8:00 PM.
A THERMAL SURFACE TROUGH BISECTS THE CWA EARLY THIS EVENING
BENEATH A BUILDING UPPER-LEVEL RIDGE. THERE APPEARS TO BE A SUBTLE
SHORT WAVE ROUNDING THE EASTERN SIDE OF THE RIDGE, AND DESPITE NOT
MUCH FORCING WITH IT THE COMBINATION OF HEAT AND HUMIDITY AND JUST
ENOUGH SURFACE FOCUS HAS LEAD TO A FEW ISOLATED SHOWERS AND
THUNDERSTORMS. THE MAJORITY OF THE CWA IS EXPECTED TO REMAIN RAIN-
FREE, HOWEVER THE HRRR AND THE SPC WRF INDICATE ADDITIONAL
DEVELOPMENT POSSIBLE FOR THE NEXT FEW HOURS SOUTHWARD. AS A
RESULT, WE ADDED IN A SLIGHT CHC POP TO ACCOUNT FOR THIS ACTIVITY
SLIDING SOUTHWARD.
THERE IS NOT A LOT OF WIND HOWEVER THE FLOW IS FORECAST TO BECOME
MORE NORTHERLY DURING THE NIGHT, WHICH MAY TRY AND PULL DOWN SOME
DRIER AIR. THIS MAY NOT BE REALIZED THOUGH HOWEVER ACROSS MUCH OF
THE CWA GIVEN LIGHT ENOUGH SURFACE WINDS /REDUCED VERTICAL MIXING/
AN ENOUGH LINGERING LOW-LEVEL MOISTURE IN PLACE. WE DID MAINTAIN A
SIMILAR TREND IN DEW POINTS FROM CONTINUITY, WHICH SHOWS A LITTLE
BIT OF LOWERING ESPECIALLY ACROSS THE FAR NORTH.
LOW TEMPERATURES WERE MOSTLY A GFS/NAM MOS BLEND WITH SOME MINOR
TWEAKS. THE HOURLY GRIDS WERE INITIALIZED WITH THE 21-22Z OBS AND
THEN SOME BLENDING IN OF THE LAMP/LAV GUIDANCE WAS USED.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
WITH SOME SLIGHTLY DRIER AIR IN PLACE TOMORROW, ACTUAL AIR
TEMPERATURES SHOULD EITHER BE THE SAME AS TODAY OR A DEGREE OR TWO
HIGHER. BUT WITH DEWPOINTS DROPPING 5 TO 10 DEGREES, APPARENT
TEMPERATURES SHOULD BE SLIGHTLY COOLER THAN WHAT WE`RE EXPERIENCING
TODAY. THAT SAID, THE EXCESSIVE HEAT WARNING FOR THE URBAN AREAS
WILL STICK, BUT WE WILL NOT BE ISSUING ANY OTHER ADVISORIES LIKE WE
HAVE UP TODAY.
SO TEMPS WILL TOP OUT IN THE MID 90S IN MOST SPOTS TOMORROW. THE
POCONOS SHOULD TOP OUT AROUND 90. WINDS WILL BE OUT OF THE NORTH,
LESS THAN 10 MPH UNDER MOSTLY SUNNY SKIES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE 500MB 12Z UA ANALYSIS HAD A BOATLOAD OF 599 DM HEIGHTS IN THE
OHIO VALLEY THIS MORNING WITH THE LATEST HEAT RIDGE. ACCORDING TO
METEOROLOGIST TOM GREEN, THE 600 DM HEIGHT OFF THE PBZ SOUNDING LAST
NIGHT IS BELIEVED (BUT NOT CONFIRMED) TO BE THE FIRST TIME THAT HAS
EVER HAPPENED THERE.
THE GFS INITIALIZATION OVERALL LOOKED PRETTY GOOD AND SLIGHTLY
BETTER THAN THE WRF-NMMB. THE LARGER GEOGRAPHICAL HEAT RIDGE LOOKS
BETTER (WELL SORT OF). DP/DTG THIS 12Z RUN IS SHOWING A ZERO SUM
GAIN AS THE RIDGE IS RETROGRADING FASTER, BUT IS ALSO LARGER LEAVING
SIMILAR HEIGHT VALUES. THE 12Z GFS ENSEMBLE MEAN IS PRETTY CLOSE TO
THE OPERATIONAL RUN, SLIGHTLY SLOWER OVERALL.
GIVEN THE ACCUMULATIVE EFFECT OF HEAT AND WHAT LOOKS LIKE 99.4%
ASSURED OF REACHING INTO THE MIDDLE 90S ALONG THE I95 URBAN CORRIDOR
INTO FRIDAY, WE DECIDED TO FORGO THE MULTIPLE HEADLINES AND EXTEND
THE EXCESSIVE HEAT WARNING THROUGH THE WORK WEEK. IN OTHER AREAS,
THURSDAY AND FRIDAY LOOK LIKE ADVISORY, POSSIBLY WARNING HEADLINE
DAYS, A LITTLE IFFIER FOR WEDNESDAY WHERE BORDERLINE HEAT ADVISORY
CRITERIA MAY BE MET. IN THESE AREAS, WE WILL CONTINUE MENTION IN THE
HWO. CONVECTIVE-WISE THE BREAK IN THE HEAT COULD COME WITH THE PRICE
OF AN ORGANIZED LINE OF STORMS ON SATURDAY. THAT IS DAYS AWAY AND
THERE IS UNCERTAINTY HOW THIS WILL AFFECT OUR AREA.
WE ARE BANKING ON A 95ISH HIGH FOR PHL TODAY AS THE TEMPLATE FOR
FUTURE DAYS MAX TEMPS. THE COMBINATION OF HOME GROWN (VS CENTRAL
CONUS BAKING) HEAT AND ALL OUR RECENT WETNESS WILL LIKELY PRECLUDE
MOST OF US FROM HITTING 100F AIR TEMPERATURES, IF THAT IS ANY
CONSOLATION.
THE SHIFT OF THE WINDS TO THE NORTH ON TUESDAY AND RELATIVE CLEAR
SKIES AND LIGHT WINDS WILL GIVE NON URBAN AREAS A BIT OF A NIGHT
TIME REPRIEVE FROM THE HEAT AS STAT GUIDANCE HAS TRENDED DOWNWARD
FROM A COUPLE OF DAYS AGO. MIN TEMPS ARE A BLEND OF CONTINUITY AND
THIS NEW GUIDANCE, STILL LIKELY FOR MINS TO ONLY FALL TO THE MID TO
UPPER 70S IN URBAN CENTERS.
ON WEDNESDAY WE ARE EXPECTING THE CAP TO HOLD WITH THE CONVECTIVE
TEMP VERY CLOSE TO THE MAX TEMP. NO THUNDER IN THE FORECAST. WE ARE
GETTING MIXED MESSAGES WITH THE THERMAL FIELDS, 1000-850MB THICK
SUGGEST EQUAL MAXES FROM TUE, WHILE 850S AND 925S SUGGEST A DEGREE
HIGHER. WE HAVE OPTED FOR ABOUT THE SAME. WE SHOULD MIX UP TO 850MB
AND WITH THE FCST AIR MASS EXPECTED TO BE RELATIVELY DRY, DEW POINT
STAT GUIDANCE DROPPING INTO THE MID TO UPPER 60S SEEMS LOGICAL. HEAT
INDEX VALUES IN URBAN CENTERS GET TO ABOUT 100F AND SERN CWA. THEY
MAY FALL JUST SHORT (POCONOS SHOULD REMAIN WELL BELOW) ELSEWHERE. SO
NO HEAT HEADLINES FOR OTHER LOCALES.
MUGGIER NIGHT WEDNESDAY NIGHT AS DEW POINTS WILL START OUT HIGHER
WITH A 1-3F BUMP UP IN MIN TEMPS FROM TUESDAY NIGHT. ON THURSDAY
BOTH THE GFS AND WRF-NMMB HAVE SUFFICIENT MOISTURE FORECAST FOR THE
CONVECTIVE TEMPERATURE TO BE REACHED. THEY ALSO HAVE A HINT OF A LEE
SIDE TROF FORMING AS A POSSIBLE CONVECTIVE FOCUS AS COULD BE THE SEA
AND BAY BREEZE FRONTS. WHILE WE ARE NOT EXPECTING ORGANIZED SEVERE,
THE POSSIBILITY OF ISOLATED PULSE TYPE SEVERE IS NOT OUT OF THE
QUESTION. THE SAME CAN BE SAID FOR FRIDAY. ON FRIDAY, AN EVEN UGLIER
COMBINATION OF TEMPERATURES AND DEW POINTS IS EXPECTED. MAX TEMPS
WERE BUMPED UP ABOUT A DEGREE, BUT HIGHER DEW POINTS ARE BRINGING
HEAT INDICES AT OR ABOVE 100F TO A LARGER PART OF OUR CWA.
AFTER ANOTHER MUGGY NIGHT, THE HEAT AND HUMIDITY MAY PEAK ON FRIDAY.
THE GFS ONCE AGAIN IS THE MOST BULLISH WITH THIS IDEA. UNLESS THERE
ARE CONSIDERABLE DEBRIS CLOUDS AROUND, AT THE LEAST MID 90S FOR
HIGHS IN THE URBAN CORRIDOR APPEAR LIKELY. COUPLED WITH WHAT SHOULD
BE HIGHER AND POOLING DEW POINTS AS THE COLD FRONT COMES CLOSER WE
HAVE THE HIEST FCST HEAT INDICES FOR THIS WEEK. MAX TEMPS WERE KEPT
ABOUT THE SAME.
SATURDAY LOOKS TO BE THE MOST CONVECTIVELY ACTIVE DAY OF THE WEEK.
SPC ALREADY HAS NORTHERN AREAS OF OUR CWA IN THEIR OUTLOOK FOR
POSSIBLE SEVERE WEATHER. AS THE JET STREAM DIPS SOUTHWARD, THE FCST
BULK SHEAR VALUES DO LOOK MORE FAVORABLE FOR ORGANIZED SEVERE AND
THE MID LEVEL LAPSE RATES AT THIS JUNCTURE ARE NOT FORECAST TO BE AN
IMPEDING FORCE. WE HAVE TO SEE HOW FRIDAY`S AND FRIDAY NIGHT`S
UPSTREAM CONVECTION AFFECTS US. FOR NOW WE CARRY THE HIEST POPS OF
THE WEEK IN THIS FORECAST PERIOD. SATURDAY COULD ALSO BE
PROBLEMATICAL FOR HEAT PENDING ON THE FRONT`S TIMING. MODELS OFTEN
GIVE CLOUDS TOO MUCH CREDIT ON THESE DAYS ON DAMPENING MAX TEMPS.
THEN FOR SUNDAY AND MONDAY WE KEPT IN LOWER CHANCES AS A SECOND FRONT
IS FORECAST TO MOVE THROUGH AND ALSO THE POSSIBILITY OF A WAVE
FORMING ON THE FRONT. THE PASSING OF THE FIRST FRONT SHOULD BRING
MORE TOLERABLE TEMPERATURES BACK INTO THE AREA.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TONIGHT...VFR. WEST-NORTHWEST WINDS AROUND 10 KNOTS EARLY, THEN BECOMING
NORTHERLY 4-8 KNOTS. AN ISOLATED SHOWER OR THUNDERSTORM THIS
EVENING. ANY LIGHT FOG LATE SHOULD BE RATHER LOCALIZED.
TUESDAY...VFR WITH FEW TO SCATTERED CUMULUS DEVELOPING WITH BASES
NEAR 5,000 FEET. NORTHERLY WINDS NEAR 10 KNOTS, ALTHOUGH PERHAPS
SHIFTING TO THE EAST OR SOUTHEAST IN THE AFTERNOON AT KACY.
OUTLOOK...
TUESDAY NIGHT THROUGH FRIDAY...MAINLY VFR WITH LATE NIGHT AND EARLY
MORNING VISIBILITY RESTRICTIONS IN HAZE POSSIBLE EACH DAY.
FRIDAY NIGHT AND ESPECIALLY SATURDAY...SOME MVFR TO IFR CONDITIONS
IN MORNING FOG AND HAZE AS WELL AS SHOWERS AND THUNDERSTORMS. GUSTY
WINDS FROM THUNDERSTORMS POSSIBLE.
&&
.MARINE...
WEST WINDS 10 KT OR LESS THIS EVENING WILL BECOME NORTHWEST BY
DAYBREAK. WINDS WILL GO NORTH TOMORROW AT THE SAME SPEEDS. SEAS
MAINLY 2 TO 3 FEET THROUGH TOMORROW AFTERNOON.
OUTLOOK...
SCA HEADLINES ARE NOT ANTICIPATED INTO FRIDAY MORNING ON THE OCEAN
AND THROUGH THE OUTLOOK PERIOD ON DELAWARE BAY. LATER FRIDAY INTO
SATURDAY ON THE OCEAN, THE INCREASING SOUTHWESTERLY FLOW PRECEDING
THE COLD FRONT COULD BRING SEAS UP TO SMALL CRAFT ADVISORY CRITERIA.
WE HAVE TAKEN AROUND A FOOT OFF OF WAVE WATCH GUIDANCE BASED ON ITS
PREVIOUS PERFORMANCE IN SIMILAR EVENTS WHICH BRINGS US NEAR THE
THRESHOLD OF SMALL CRAFT ADVISORY CRITERIA VS BEING WELL INTO IT.
&&
.CLIMATE...
BESIDE THE DAYTIME HEAT, THERE HAVE NOT BEEN TOO MANY PLEASANT
NIGHTS FOR SLEEPING. PRIOR TO THIS WEEK MORE OF THE ABOVE NORMAL
TEMPERATURE DEPARTURES THIS MONTH HAVE BEEN ATTRIBUTED TO THE NIGHTS
AS DEW POINT LEVELS HAVE NOT BEEN PLEASANT AT ALL. SO MUCH SO THAT
TO DATE, THE NIGHTMARISH AVERAGE MINIMUM TEMPERATURE IN PHILADELPHIA
OF 74.6 DEGREES IS THE WARMEST ON RECORD FOR ANY MONTH DATING BACK
TO 1874.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR PAZ060-061-101-
103-105.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR PAZ070-071-
102-104-106.
NJ...HEAT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR NJZ008>010-012-
013.
EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR NJZ015-
017>019.
DE...EXCESSIVE HEAT WARNING UNTIL 8 PM EDT FRIDAY FOR DEZ001.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DRAG/GIGI
NEAR TERM...GORSE
SHORT TERM...KRUZDLO
LONG TERM...GIGI
AVIATION...DRAG/GIGI/GORSE
MARINE...GIGI/KRUZDLO
CLIMATE...GIGI
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
123 PM CDT MON JUL 15 2013
.DISCUSSION...
925 AM CDT
HAVE UPDATED GRIDS AND TEXT PRODUCTS TO HIT THUNDERSTORM CHANCES
HARDER FOR THIS AFTERNOON.
GOES IMAGERY THIS MORNING SHOWS A WEAK SHORTWAVE PUSHING NORTHWARD
INTO THE REGION ON THE SOUTHWESTERN PERIPHERY OF THE VERY STRONG
UPPER HIGH CENTERED JUST OFF TO OUR EAST. INTERESTINGLY...THIS WAVE
CAN BE TRACED BACK TO WHERE TROPICAL STORM CHANTEL DISSIPATED OFF
OFF THE SOUTH EAST COAST OVER THE WEEKEND. SCTD TSRA DEVELOPED OVER
EASTERN TN VALLEY REGION WITH THIS FEATURE SUNDAY AFTERNOON AND
BECOMING MORE CONCERNED THAT WE COULD SEE A REPEAT IN OUR CWA THIS
AFTERNOON.
THE 12Z ILX SOUNDING SAMPLED A VERY TROPICAL AIRMASS WITH PWATS OVER
2 INCHES...WITH GOES SOUNDER PWAT IMAGERY SHOWING A POOL OF 2-2.25"
PWATS EXTENDING FROM CENTRAL IL NORTHEAST INTO NORTHERN INDIANA
PUSHING NORTHWESTWARD INTO THE REGION. MODIFYING THE 12Z ILX/DVN
SOUNDINGS FOR SFC TEMPS IN THE MID-UPPER 80S AND DEWPOINTS IN THE
LOW/MID 70S YIELD MLCAPE VALUES OF 2500-3000 J/KG THIS AFTERNOON
DESPITE THE WARM MID LEVEL TEMPS/MID LAPSE RATES WITH NO CONVECTIVE
INHIBITION. RUC13 FORECAST SOUNDINGS FOR THIS AFTERNOON SHOW VERY
SIMILAR FORECAST VALUES LENDING MORE CONFIDENCE TO THE IDEA THAT IT
WILL GROW STRONGLY UNSTABLE AND UNCAPPED THIS AFTERNOON.
IN ADDITION TO THE WEAK SHORTWAVE...WHICH SEEMS AS THOUGH IT MAY
TEND TO FAVOR CONVECTION FIRING OVER WESTERN AND NORTHWESTERN CWA
THIS AFTERNOON THE OTHER AREA THAT COULD FOCUS DEVELOPMENT IS ALONG
THE ANTICIPATED LAKE BREEZE THIS AFTERNOON. WHILE THE LAKE BREEZE
AND SUBSEQUENT CONVERGENCE WILL NOT BE STRONG OR TERRIBLY DEEP...THE
THE VERY HIGH DEWPOINTS AND RESULTANT LOW LFC HEIGHTS MEAN IT WON`T
BE TOO HARD FOR PARCELS TO REACH LFC. WIND SHEAR PROFILES ARE WEAK
AND MID LEVEL TEMPS VERY WARM SO HAIL THREAT SHOULD BE VERY
LOW...BUT WITH PWATS OVER 2 INCHES AND STRONG INSTABILITY POTENTIAL
FOR BRIEF BUT TORRENTIAL RAINFALL RATES EXISTS AND CANNOT RULE OUT A
WET MICROBURST OR TWO.
IZZI
//PREV DISCUSSION...
253 AM CDT
WARMER AND MORE HUMID WEATHER WILL CONTINUE TO TAKE CENTER STAGE
THIS WEEK. WHILE THE POTENTIAL FOR A FEW ISOLATED SHOWER OR
THUNDERSTORMS WILL EXIST PARTICULARLY THIS AFTERNOON...IT APPEARS
THAT A MORE SIGNIFICANT CHANCE OF RAIN WILL HOLD OFF UNTIL LATE IN
THE WEEK WHEN A COLD FRONT EVENTUALLY SETTLES SOUTH ACROSS THE
MIDWEST.
ANALYSIS OF EVENING UPPER AIR DATA AND OVERNIGHT GOES WATER VAPOR
IMAGERY DEPICT A FAIRLY UNUSUAL WEATHER PATTERN FOR MID-SUMMER...
WITH A CLOSED LOW DRIFTING WESTWARD ACROSS THE SOUTHERN PLAINS AND A
STRONG UPPER RIDGE BUILDING WEST ACROSS THE UPPER OHIO VALLEY.
SOUTHEAST FLOW BETWEEN THESE TWO SYSTEMS WAS SPREADING LOW-LEVEL
MOISTURE INTO THE FORECAST AREA...AS NOTED IN UPSTREAM 00Z SOUNDINGS
SUCH AS NASHVILLE TN. THIS INCREASE IN LOW LEVEL MOISTURE HAS LED TO
ISOLATED AFTERNOON CONVECTION ACROSS PARTS OF THE LOWER OHIO VALLEY
OVER THE PAST COUPLE OF DAYS...AND MODEL GUIDANCE CONTINUES TO
INDICATE CONVECTION WOULD DEVELOP ACROSS PARTS OF THE WFO LOT
FORECAST AREA TODAY. GUIDANCE HAS BEEN OVER-FORECASTING THE EXTENT
OF AFTERNOON CONVECTION UPSTREAM HOWEVER...LIKELY DUE TO MODELED
BOUNDARY LAYER DEW POINT TEMPS THAT ARE TOO HIGH. WITH RELATIVELY
WEAK LOW LEVEL CONVERGENCE AND MORE CONSERVATIVE INSTABILITY
EXPECTED WILL MAINTAIN ONLY SLIGHT CHANCE POPS FOR ISOLATED
CONVECTIVE DEVELOPMENT THIS AFTERNOON...AND THAT MAINLY ALONG THE
LAKE BREEZE BOUNDARY AND NORTHERN IL WHERE LOW-LEVEL CONVERGENCE
WILL BE MORE FOCUSED AND AWAY FROM STRONGER MID/UPPER LEVEL RIDGING
FARTHER TO THE EAST. THUNDERSTORM CHANCES SHOULD BE EVEN LOWER
TUESDAY-THURSDAY AS CENTER OF UPPER RIDGE CONTINUES TO BUILD
WESTWARD ACROSS INDIANA AND ILLINOIS AND SUBSIDENCE AND WARM
MID-LEVEL TEMPS BECOME LESS FAVORABLE FOR CONVECTION.
WITH BUILDING UPPER RIDGE...850MB TEMPS SLOWLY WARM FROM +17/18C
TODAY TO +19/20C LATER IN THE WEEK. TAKING LOCAL CLIMATOLOGY AND
MODEL LOW-LEVEL THERMAL FIELDS INTO ACCOUNT...TEMPS SHOULD WARM FROM
AROUND 90 TODAY TO THE LOWER AND EVEN A FEW MID 90S WED/THURS/FRI.
WITH DEW POINT TEMPERATURES MAINLY IN THE LOWER 70S...THIS SHOULD
SUPPORT HEAT INDEX VALUES MAXING OUT IN THE MID 90S TODAY...AND
AROUND 100 TUESDAY THROUGH FRIDAY. THIS WOULD PRECLUDE ANY HEAT
ADVISORY HEADLINES AT THIS POINT...THOUGH THE PROLONGED PERIOD OF
HEAT AND HUMIDITY WILL HAVE TO BE MONITORED. LAKE COOLING WILL BE
FAIRLY MINIMAL OVER THE NEXT FEW DAYS...MAINLY CONFINED TO THE
IMMEDIATE SHORE AREAS AS LOW LEVEL FLOW BECOMES MORE
WEST-SOUTHWESTERLY.
LONGER RANGE MODEL GUIDANCE IS IN VERY DECENT AGREEMENT THAT THE
UPPER RIDGE OVER THE MIDWEST WILL EVENTUALLY DRIFT SOUTH AND BREAK
DOWN TOWARD THE END OF THE WEEK...WITH AN UPPER TROUGH DEVELOPING
OVER EASTERN CANADA AND THE GREAT LAKES/NORTHEAST STATES. THIS
SHOULD ALLOW A COLD FRONT TO SAG ACROSS THE AREA FRIDAY/FRIDAY
NIGHT...BRINGING A MORE SIGNIFICANT CHANCE OF THUNDERSTORMS
FRIDAY/FRIDAY NIGHT...AS WELL AS COOLER TEMPERATURES AND MORE
PROMINENT LAKE BREEZES TO THE AREA NEXT WEEKEND.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHOWERS AND POSSIBLE THUNDERSTORMS THROUGH EARLY AFTERNOON.
LENNING
//DISCUSSION...UPDATED 18Z...
SHOWER ACTIVITY THAT POPPED ALONG THE LAKE BREEZE LATE THIS
MORNING IS TRENDING DOWNWARD IN COVERAGE AND STRENGTH AS WE MOVE
INTO EARLY AFTERNOON. EXPECT THE FOCUS TO MOVE WEST WITH LAKE
BREEZE AND OUTFLOW FROM EARLIER ACTIVITY. A FEW GUSTS INTO THE
TEENS WITH VARIABLE WIND DIRECTIONS ARE POSSIBLE WITH THESE
SHOWERS. OTHERWISE WILL CONTINUE THE GRADUAL VEERING OF WINDS
FROM ENE AROUND TO EAST AND THEN EVENTUALLY SOUTH.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM TO HIGH CONFIDENCE THAT SHOWER ACTIVITY WILL DIMINISH
OVER THE TERMINALS AND FOCUS MORE TO THE WEST BY LATER THIS
AFTERNOON.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUE NIGHT...MVFR VISIBILITY DUE TO HZ AND BR.
WED AND THU...MVFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
THU...VFR VISIBILITY INTO MID MORNING DUE TO HZ AND BR.
FRI...CHANCE OF TSRA DURING THE AFTERNOON...LIKELY TSRA DURING
THE NIGHT CREATING PERIODS OF MVFR AND IFR.
SAT...CHANCE OF TSRA DURING DAYLIGHT HOURS.
SUN...VFR. NO SIG WX.
TRS
&&
.MARINE...
328 AM CDT
A BROAD AREA OF HIGH PRESSURE WILL REMAIN CENTERED OVER THE
LOWER GREAT LAKES AND THE UPPER OH VALLEY TODAY KEEPING WINDS AT
10 KT OR LESS. THE HIGH WILL START TO DRIFT SLOWLY WSW TONIGHT
AND WILL BE CENTERED OVER THE LOWER OH VALLEY AND THE MID MS
VALLEY BY THURSDAY MORNING. IN RESPONSE...WINDS WILL GENERALLY
VEER FROM SOUTHEAST AND SOUTH TO SOUTH AND SOUTHWEST AND START TO
FRESHEN. DURING THURSDAY AND THURSDAY NIGHT A COLD FRONT WILL BE
DROPPING SOUTHWARD FROM ONTARIO...CROSSING LAKE SUPERIOR BY
FRIDAY MORNING. AHEAD OF THE COLD FRONT WINDS FROM THE SOUTHWEST
WILL INCREASE TO A MODERATE BREEZE. THE COLD FRONT WILL CONTINUE
SLOWLY SOUTHWARD FRIDAY...CROSSING THE NORTHERN PORTION OF LAKE
MI BY LATE IN THE DAY...AND REACHING THE S TIP BY DAWN SATURDAY.
IL AND IN NEARSHORE WATERS WILL BE UNDER THE INFLUENCE OF A LAKE
BREEZE WITH ENHANCED ONSHORE WINDS DURING THE THIS AFTERNOON.
WINDS WILL RETURN TO ONSHORE AGAIN TUESDAY AFTERNOON...BUT MAINLY
ONLY ALONG THE IL SHORE.
TRS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS LINCOLN IL
102 PM CDT MON JUL 15 2013
.DISCUSSION...
ISSUED 1047 AM CDT MON JUL 15 2013
WITH MOISTURE INCREASING FROM YESTERDAY WITH SOME SCT SPRINKLES
AND PRETTY EXPANSIVE CU FIELD...SAT IMAGERY IS ON TRACK WITH MORE
CLOUD COVER FOR THIS AFTERNOON AS WELL. SOME OF THE CU GETTING A
BIT TALL WITH SOME SHOWERS POPPING UP NORTH OF CWA. EARLY CU FIELD
IN THE FAR SE HEADED THE SAME WAY. WITH PLENTY OF MUGGY AIR TO
WORK WITH IN THE COLUMN FROM THIS MORNINGS SOUNDING...AND A
SHORTWAVE RIPPLING THROUGH THE CWA...THINK A SLIGHT UPWARD ADJUSTMENT
IN THE POPS MAY BE WARRANTED. CONCERN FOR GOING TOO HIGH OR
WIDESPREAD WITH REGARDS TO THE LOCATION OF THE BEST LIFT WITH THE
SMALL WAVE BY THE TIME PEAK HEATING HITS THIS AFTERNOON. WITH
RATHER NON EXISTENT CAP...SHOULD NOT TAKE MUCH. HAVE BOOSTED FOR
AT LEAST A MENTION TO THE SE FOR SOME ISO SHOWERS...THOUGH SHOULD
BE WELL BEHIND THE WAVE BY THIS AFTERNOON.
&&
.AVIATION...
ISSUED 1257 PM CDT MON JUL 15 2013
CU FIELD A BIT DENSE AND LACK OF CAP RESULTING IN SOME SCT SHOWERS
ACROSS THE AREA. NONE OF THE TERMINALS ARE IN THE PATH OF THE
CURRENT ECHOS...BUT WILL LIKELY SEE ONE OR TWO BEFORE THE END OF
THE DAY. VCTS TO COVER INCREASING THREAT OF THUNDER AS THE
AFTERNOON PROGRESSES. LIGHT WINDS THROUGH THE OVERNIGHT MAY RESULT
IN SOME MVFR FOG...ESP WITH THE INCREASING MOISTURE ACROSS THE
AREA AND THE LACK OF MIXING OUT LIKELY WITH CLOUD COVER
INCREASING.
HJS
&&
.PREV DISCUSSION...
ISSUED 330 AM CDT MON JUL 15 2013
SHORT TERM...TODAY THROUGH FRIDAY
FORECAST CONCERN WILL BE THE HIGH HEAT AND HUMIDITY AS STRONG 600
DM 500 MB HIGH PRESSURE OVER EASTERN OHIO/WESTERN PA RETROGRADES
WESTWARD ACROSS THE SOUTHERN GREAT LAKES AND INTO IL BY WED. 00Z
MODELS ARE IN FAIR AGREEMENT NEXT FEW DAYS AND WILL USE A BLEND.
A WEAK SHORT WAVE AND SURFACE TROF TO LIFT NW ACROSS IL DURING
THE DAY AND INTERACT WITH UNSTABLE AIRMASS WITH CAPES 2000-3000
J/KG AND PRECIPITABLE WATER VALUES 1.75 TO 2.25 INCHES TO DEVELOP
ISOLATED SHOWERS AND THUNDERSTORMS THIS AFTERNOON WEST OF I-57.
SOME MODELS LIKE THE NAM SHOW CONVECTION DEVELOPING DURING THE
MORNING AND IF THIS OCCURS THEN ISOLATED CHANCES IN EASTERN IL
WOULD BE POSSIBLE TOO. LEANED ON THE HRRR AND RUC MODELS FOR
CONVECTION CHANCES TODAY. SCATTERED TO BROKEN CUMULUS CLOUDS TO
DEVELOP IN THE AFTERNOON. HIGHS IN THE UPPER 80S OVER CENTRAL IL
AND LOWER 90S BY THE WABASH RIVER WHICH IS DRYER TODAY. DEWPOINTS
IN THE LOWER 70S TO GIVE HEAT INDICES PEAKING IN MID TO UPPER 90S
THIS AFTERNOON.
ISOLATED CONVECTION COULD LINGER OVER THE IL RIVER VALLEY EARLY
THIS EVENING UNTIL SUNSET...OTHERWISE FAIR AND MUGGY WEATHER
EXPECTED TONIGHT WITH LOWS IN THE LOWER 70S. TEMPS GRADUALLY HEAT
UP NEXT FEW DAYS AS STRONG UPPER LEVEL HIGH PRESSURE RIDGE SETTLES
INTO IL BY WED. HIGHS TUE 89 TO 93 WITH AFTERNOON HEAT INDICES
AROUND 100F. HIGHS 90 TO 95F WED-FRI WITH AFTERNOON HEAT INDICES
PEAKING FROM 98 TO 105F AND HIGHEST IN SOUTHEAST OF I-70 IN
SOUTHEAST IL. BEEN THIS HOT BEFORE ON JUNE 12 BUT THIS WILL BE THE
LONGEST HEAT WAVE OF THE SUMMER...LASTING MUCH OF THIS WORK WEEK.
CHANCES OF SHOWERS AND THUNDERSTORMS LESS THAN 20% EACH AFTERNOON
AND EARLY EVENING DURING MID AND LATE WORK WEEK.
LONG TERM...FRIDAY NIGHT THROUGH SUNDAY
EXTENDED MODELS CONTINUE TO SHOW STRONG UPPER LEVEL RIDGE SLOWLY
WEAKENING AND SHIFTING SOUTHWARD ALLOWING COLD FRONT TO PRESS
SOUTHWARD ACROSS THE GREAT LAKES REGION FRIDAY AND THROUGH IL SAT
AND SAT NIGHT...AND INTO THE OHIO VALLEY SUNDAY. HAVE CHANCES OF
SHOWERS AND THUNDERSTORMS HIGHEST OVER NORTHERN AREAS FRI NIGHT
WITH JUST SLIGHT CHANCES IN SOUTHEAST IL. THEN CHANCE OF
CONVECTION ACROSS AREA SAT AND BEST CHANCES SHIFT INTO SE IL SAT
NIGHT AND SUNDAY. HIGHS BY SUNDAY IN THE MID TO UPPER 80S WITH
DEWPOINTS IN THE MID TO UPPER 60S SO SOME RELIEF FROM THE HIGH
HEAT AND HUMIDITY.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
245 PM MDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 138 PM MDT MON JUL 15 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 581 DM CLOSED LOW
CENTERED OVER SW OKLAHOMA...WITH A 599 DM RIDGE ACROSS THE EASTERN
CONUS EXTENDING WEST ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS
MOISTURE CONTINUING TO ROTATE AROUND EASTERN EXTEND OF CLOSED LOW
INTO SOUTHERN KS. RAP/LATEST NAM SHOW A CURVED JET STRUCTURE ACROSS
THE NORTHERN PART OF CLOSED LOW OVER SW KS AND SEVERAL VORT MAXES
ROTATING THROUGH THE NORTHERN EXTENT OF THIS LOW. COMPOSITE RADAR
SHOWS SHOWER ACTIVITY HAVING DEVELOPED WITH THESE FEATURES MOVING TO
ACROSS CENTRAL AND SOUTHWEST KANSAS. VIS SATELLITE SHOWS A
WIDESPREAD CU FIELD IN PLACE ACROSS OUR CWA THAT HAS DEVELOPED WITH
DAYTIME HEATING AND COLD POOL ALOFT.
LATEST SHORT RANGE GUIDANCE SHOWS THE ACTIVITY CURRENTLY SOUTH AND
EAST OF THE CWA FALLING APART BY 00Z AS IT MOVES TOWARDS OUR CWA. AT
THIS POINT I AM NOT SURE WE WILL ACTUALLY SEE ANY SHOWERS DEVELOP
WITH CU FIELD...THOUGH UNTIL WE LOOSE DAYTIME HEATING I COULDNT RULE
OUT SHOWERS SPREADING INTO THE SOUTHERN HALF CONSIDERING RADAR
TRENDS...AND AT LEAST SOME LARGE SCALE FORCING STILL IN PLACE JUST TO
OUR SOUTH. I DO NOT EXPECT THIS TO BE WIDESPREAD AND SHOULD QUICKLY
END AS WE LOOSE FAVORABLE LOW LEVEL LAPSE RATES DUE TO DIURNAL
COOLING.
SOUTHERLY FLOW WILL KEEP BL MOISTURE IN PLACE OVERNIGHT AND
TUESDAY...AND THERE IS SOME INDICATION OF A FEW SHOWERS ACROSS
SOUTHERN KS...POSSIBLY INTO OUR CWA AS UPPER LOW CONTINUES TO SLOWLY
MOVE WEST. WITH LITTLE IN THE WAY OF INSTABILITY AND STRONG
SUBSIDENCE BUILDING IN FROM THE NORTH TONIGHT I DECIDED TO KEEP
FORECAST DRY. WE DO BEGIN TO SEE A SIMILAR SET UP AS THIS AFTERNOON
REGARDING INCREASING LAPSE RATES BELOW COLD POOL...HOWEVER WITH
RIDGE BEGINNING TO HOLD MORE INFLUENCE AND DRIER AIR MOVING INTO THE
REGION ALOFT...I DECIDED TO KEEP POPS SILENT FOR NOW. I DID KEEP
PATCHY FOG MENTION IN THE FORECAST FOR TUESDAY MORNING...AND GOOD BL
MOISTURE ADVECTING IN FROM THE SOUTH. WITH BL WINDS
INCREASING...IF WE SEE SURFACE WINDS AROUND 10KT THE LOW LEVELS
MAY BE TOO MIXED FOR FOG DEVELOPMENT...SO I KEPT COVERAGE PATCHY.
THERE IS LITTLE CHANGE REGARDING THE AIR MASS OVER OUR CWA
TUESDAY...AND THERE ARE SIMILAR TRENDS REGARDING CLOUD COVER. TEMPS
ON TUESDAY SHOULD BE VERY SIMILAR TO TODAY...WITH HIGHS RANGING FROM
THE UPPER 70S WEST TO UPPER 80S EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 244 PM MDT MON JUL 15 2013
DRY CONDITIONS WITH A SLOW WARMING TREND WILL BE THE DOMINANT
WEATHER PATTERN UNTIL THE OF THE WEEK AS THE HIGH PRESSURE OVER THE
EASTERN CONUS MOVES WEST TOWARD THE ROCKIES. WEDNESDAY AND THURSDAY
WILL BE WINDY AS 850MB WINDS NEAR 30KTS ARE ABLE TO MIX DOWN TO
THE GROUND AHEAD OF THE RETROGRADING RIDGE. PRECIPITATION CHANCES
RETURN FRIDAY THROUGH EARLY NEXT WEEK AS A FEW UPPER LEVEL
DISTURBANCES MOVE THROUGH THE NORTHWEST FLOW OVER THE AREA.
FRIDAY A WEAK FRONT/SURFACE TROUGH MOVES OVER THE AREA...COOLING THE
ABOVE NORMAL TEMPERATURES DOWN AND HELPING WITH PRECIP. CHANCES AS
AN UPPER LEVEL TROUGH ALSO MOVES THROUGH.
THE WEAK FRONT LINGERS OVER THE SOUTHERN PART OF THE AREA THROUGH
SATURDAY WHICH MAY AID IN CREATING SOME STORMS FOR THE AREA.
PRECIPITATION CHANCES LINGER THROUGH EARLY NEXT WEAK AS ANOTHER WEAK
UPPER LEVEL TROUGH MOVES ACROSS THE AREA.
TEMPERATURES THROUGH THE PERIOD WILL START OUT NEAR NORMAL THEN WARM
TO NEAR/ABOVE NORMAL BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1121 AM MDT MON JUL 15 2013
GUSTY SOUTHEAST WINDS WILL DEVELOP THIS AFTERNOON AT BOTH
TERMINALS...WITH GUSTS BETWEEN 20-25KT EXPECTED. WINDS SHOULD
DIMINISH WITH END OF DAYTIME HEATING BEFORE INCREASING AGAIN
TUESDAY MORNING. FOG WILL ONCE AGAIN BE POSSIBLE AT BOTH TERMINALS
BY SUNRISE TUESDAY WITH MOIST BL STILL IN PLACE. WITH BL WINDS
INCREASING...I AM SKEPTICAL OF THESE LOWER CONDITIONS UNLESS
SURFACE WINDS ARE MUCH LIGHTER...AND IN THAT CASE FOG LAYER WOULD
BE FAIRLY SHALLOW. KMCK IS FARTHER REMOVED FROM BEST BL MOISTURE
IN THE SOUTH...THOUGH LOCAL EFFECTS AND LINGERING LOW LEVEL
MOISTURE COULD STILL SUPPORT LIGHT FOG DEVELOPMENT. CURRENT
FORECAST IS FOR MVFR VIS/CIGS AT KGLD AND BETTER CONDITIONS AT
KMCK...THOUGH MET GUIDANCE WOULD ACTUALLY SUPPORT IFR AT BOTH
TERMINALS. I PREFER BEING CONSERVATIVE AT THIS POINT...AND WILL
ALLOW NEXT FEW SCHEDULED UPDATES TO FINE TUNE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JTL
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
138 PM MDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 138 PM MDT MON JUL 15 2013
LATEST WV IMAGERY AND RAP H5 ANALYSIS SHOW 581 DM CLOSED LOW
CENTERED OVER SW OKLAHOMA...WITH A 599 DM RIDGE ACROSS THE EASTERN
CONUS EXTENDING WEST ACROSS THE NORTHERN PLAINS. WV IMAGERY SHOWS
MOISTURE CONTINUING TO ROTATE AROUND EASTERN EXTEND OF CLOSED LOW
INTO SOUTHERN KS. RAP/LATEST NAM SHOW A CURVED JET STRUCTURE ACROSS
THE NORTHERN PART OF CLOSED LOW OVER SW KS AND SEVERAL VORT MAXES
ROTATING THROUGH THE NORTHERN EXTENT OF THIS LOW. COMPOSITE RADAR
SHOWS SHOWER ACTIVITY HAVING DEVELOPED WITH THESE FEATURES MOVING TO
ACROSS CENTRAL AND SOUTHWEST KANSAS. VIS SATELLITE SHOWS A
WIDESPREAD CU FIELD IN PLACE ACROSS OUR CWA THAT HAS DEVELOPED WITH
DAYTIME HEATING AND COLD POOL ALOFT.
LATEST SHORT RANGE GUIDANCE SHOWS THE ACTIVITY CURRENTLY SOUTH AND
EAST OF THE CWA FALLING APART BY 00Z AS IT MOVES TOWARDS OUR CWA. AT
THIS POINT I AM NOT SURE WE WILL ACTUALLY SEE ANY SHOWERS DEVELOP
WITH CU FIELD...THOUGH UNTIL WE LOOSE DAYTIME HEATING I COULDNT RULE
OUT SHOWERS SPREADING INTO THE SOUTHERN HALF CONSIDERING RADAR
TRENDS...AND AT LEAST SOME LARGE SCALE FORCING STILL IN PLACE JUST TO
OUR SOUTH. I DO NOT EXPECT THIS TO BE WIDESPREAD AND SHOULD QUICKLY
END AS WE LOOSE FAVORABLE LOW LEVEL LAPSE RATES DUE TO DIURNAL
COOLING.
SOUTHERLY FLOW WILL KEEP BL MOISTURE IN PLACE OVERNIGHT AND
TUESDAY...AND THERE IS SOME INDICATION OF A FEW SHOWERS ACROSS
SOUTHERN KS...POSSIBLY INTO OUR CWA AS UPPER LOW CONTINUES TO SLOWLY
MOVE WEST. WITH LITTLE IN THE WAY OF INSTABILITY AND STRONG
SUBSIDENCE BUILDING IN FROM THE NORTH TONIGHT I DECIDED TO KEEP
FORECAST DRY. WE DO BEGIN TO SEE A SIMILAR SET UP AS THIS AFTERNOON
REGARDING INCREASING LAPSE RATES BELOW COLD POOL...HOWEVER WITH
RIDGE BEGINNING TO HOLD MORE INFLUENCE AND DRIER AIR MOVING INTO THE
REGION ALOFT...I DECIDED TO KEEP POPS SILENT FOR NOW. I DID KEEP
PATCHY FOG MENTION IN THE FORECAST FOR TUESDAY MORNING...AND GOOD BL
MOISTURE ADVECTING IN FROM THE SOUTH. WITH BL WINDS
INCREASING...IF WE SEE SURFACE WINDS AROUND 10KT THE LOW LEVELS
MAY BE TOO MIXED FOR FOG DEVELOPMENT...SO I KEPT COVERAGE PATCHY.
THERE IS LITTLE CHANGE REGARDING THE AIR MASS OVER OUR CWA
TUESDAY...AND THERE ARE SIMILAR TRENDS REGARDING CLOUD COVER. TEMPS
ON TUESDAY SHOULD BE VERY SIMILAR TO TODAY...WITH HIGHS RANGING FROM
THE UPPER 70S WEST TO UPPER 80S EAST.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 303 AM MDT MON JUL 15 2013
TOMORROW NIGHT-WEDNESDAY NIGHT...AS UPPER LOW EXITS THE AREA LARGE
H5 RIDGE WILL ONCE AGAIN BE THE PRIMARY SYNOPTIC SCALE FEATURE
IMPACTING THE AREA. WITH LARGE SCALE SUBSIDENCE...EXPECT DRY
CONDITIONS TO PREVAIL WITH TEMPERATURES WARMING THROUGH THE PERIOD.
A DEVELOPING SFC TROUGH WILL BRING SOME GUSTY SOUTHERLY WINDS TO THE
AREA ON WEDNESDAY WITH AFTERNOON SPEEDS AROUND 20KTS A STRONG
POSSIBILITY...WITH WINDS REMAINING UP THROUGH THE NIGHT HOLDING LOW
TEMPS UP SEVERAL DEGREES.
.EXTENDED RANGE...(THU JUL 18 THRU SUN JUL 21)
LATE WEEK THROUGH THE WEEKEND IS LOOKING LIKE TYPICAL JULY WEATHER
WITH NEAR NORMAL TEMPERATURES AND CHANCES FOR STORMS ON A FEW DAYS.
SYNOPTIC PATTERN STARTS AS A WEAK UPPER LEVEL RIDGE ACROSS MOST OF
THE CENTRAL CONUS AS AN UPPER HIGH WEAKENS IN THE EAST AND A RIDGE
BEGINS TO DEVELOP OVER THE WEST. AS THIS RIDGE IN THE WEST BUILDS
AND MOVES EAST THE GEM AND GFS DEVELOP A SMALL BUT POWERFUL VORT MAX
WEST OF THE CENTRAL ROCKIES AND EVENTUALLY MOVES IT EAST FRIDAY INTO
SATURDAY WITH AN ASSOCIATED COLD FRONT AND PLENTY OF PRECIPITATION.
THE GFS ENSEMBLES CARRIES THIS IDEA OF A COLD FRONT STRETCHING FROM
THE GREAT LAKES TO THE CENTRAL ROCKIES MOVING SOUTH WITH WIDESPREAD
PRECIPITATION ALONG THE FRONT. ECMWF DOES NOT AGREE ENTIRELY WITH
SUCH AN ORGANIZED SOLUTION...BUT IT DOES AT LEAST CARRY THE IDEA OF
THE FRONT ALBEIT WITH MUCH LESS PRECIP. THE EXTENDED INIT GAVE
QUITE HIGH POPS IN COMPARISON TO STATISTICAL GUIDANCE...SO WHILE
SOME OF THE POPS HAVE BEEN NUDGED DOWN GENERALLY WENT ALONG WITH THE
MODEL BLEND OF THE INIT. AT THIS POINT IT IS TOO FAR TO NAIL DOWN
ALL THE DETAILS...BUT MODEL SOUNDINGS ARE INDICATING A VERY MOIST
ENVIRONMENT AND SLOW STORM MOTIONS COULD LEAD TO A HEAVY
RAINFALL/FLOODING THREAT SIMILAR TO YESTERDAY. TEMPS OVER THE
PERIOD WILL BE NEAR NORMAL /HIGHS IN THE LOW 90S/ WITH THE EXCEPTION
OF BEING A BIT COOLER ON SATURDAY AFTER THE FRONT MOVES THROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1121 AM MDT MON JUL 15 2013
GUSTY SOUTHEAST WINDS WILL DEVELOP THIS AFTERNOON AT BOTH
TERMINALS...WITH GUSTS BETWEEN 20-25KT EXPECTED. WINDS SHOULD
DIMINISH WITH END OF DAYTIME HEATING BEFORE INCREASING AGAIN
TUESDAY MORNING. FOG WILL ONCE AGAIN BE POSSIBLE AT BOTH TERMINALS
BY SUNRISE TUESDAY WITH MOIST BL STILL IN PLACE. WITH BL WINDS
INCREASING...I AM SKEPTICAL OF THESE LOWER CONDITIONS UNLESS
SURFACE WINDS ARE MUCH LIGHTER...AND IN THAT CASE FOG LAYER WOULD
BE FAIRLY SHALLOW. KMCK IS FARTHER REMOVED FROM BEST BL MOISTURE
IN THE SOUTH...THOUGH LOCAL EFFECTS AND LINGERING LOW LEVEL
MOISTURE COULD STILL SUPPORT LIGHT FOG DEVELOPMENT. CURRENT
FORECAST IS FOR MVFR VIS/CIGS AT KGLD AND BETTER CONDITIONS AT
KMCK...THOUGH MET GUIDANCE WOULD ACTUALLY SUPPORT IFR AT BOTH
TERMINALS. I PREFER BEING CONSERVATIVE AT THIS POINT...AND WILL
ALLOW NEXT FEW SCHEDULED UPDATES TO FINE TUNE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JRM/JJM
AVIATION...DR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
130 PM EDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 427 AM EDT MON JUL 15 2013
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW SPRAWLING UPR RDG
CENTERED NEAR LAKE ERIE ON THE SRN FLANK OF FASTER WSW FLOW ALF OVER
CANADA. WITH VERY DRY MID LVLS AND SUBSIDENCE INVRN SHOWN ON THE 00Z
MPX/GRB/APX RAOBS...SKIES ARE MOCLR OVER THE CWA. RIBBON OF MSTR/
BAND OF SHRA TO THE SE OF STNRY FNT RUNNING FM MN INTO NW ONTARIO IS
JUST NW OF LK SUP...BUT ONLY SCT CLDS ARE IMPACTING THE WRN CWA.
MORE LO/MID LVL MSTR IS PRESENT OVER THE OH RIVER VALLEY/LOWER GRT LKS
AND TENDING TO DRIFT TO THE NW ARND THE CLOSED LO PER WV IMAGERY.
MAIN FCST CONCERNS THRU TNGT ARE TEMPS AND POPS...RELATED TO MSTR
RIBBON JUST TO THE NW AND AREA OF MOISTER AIR DRIFTING NWWD THRU THE
OH RIVER VALLEY/LOWER GRT LKS.
TODAY...UPR RDG IS FCST TO REMAIN DOMINANT OVER THE GREAT LKS...
WHICH SHOULD KEEP PCPN ASSOCIATED WITH MSTR RIBBON IN MN TO THE NW
OF ALL BUT NW LK SUP. THE BIGGER QUESTION IS WHETHER ENUF MSTR WL
ARRIVE FM THE S TO GENERATE SOME DIURNAL SHRA/TS IN THE ABSENCE OF
ANY DYNAMIC FORCING THAT WOULD TEND TO MAINTAIN THE STRENGTH OF THE
SUBSIDENCE INVRN. A FEW OF THE MODELS INCLUDING THE 00Z NAM GENERATE
SOME PCPN OVER THE FAR SCENTRAL THIS AFTN...MAINLY THE NAM FCST
SDNGS FOR MNM SHOW KINX INCRSG FM 15 AT 18Z TO 34 AT 00Z...BUT THE
NAM APPEARS TO WEAKEN THE SUBSIDENCE INVRN TOO MUCH. CONSIDERING THE
OBSVD STRENGTH OF THE UPR RDG/SUBSIDENCE INVRN SHOWN ON THE 00Z GRB
RAOB...PREFER THE MORE STABLE LOOK OF THE 00Z LOCAL WRF/ARW AND THE
DRY FCST IT SHOWS IN THE ABSENCE OF ANY LARGER SCALE FORCING OTHER
THAN MSTR ADVECTION. EVEN THOUGH MORE DIURNAL CU WL DVLP TODAY WITH
INFLUX OF LLVL MSTR FM THE S...EXPECT TEMPS TO RISE WELL INTO THE
80S AGAIN IN THE PRESENCE OF H85 TEMPS ARND 18C. BUT WITH RATHER
WEAK PRES GRADIENT...LK BREEZES SHOULD KEEP COASTAL AREAS COOLER.
TNGT...THE MAJORITY OF THE MODELS DO GENERATE PCPN TNGT ASSOCIATED
WITH THE RETURNING MSTR. BUT THE QUESTION REMAINS WHY THE MID LVL
INVRN WOULD WEAKEN AS MUCH AS SHOWN ON THE FCST SDNGS TO ALLOW SHRA
TO FORM IN THE PRESENCE OF NOCTURNAL COOLING. OFTEN DURING THIS TIME
OF YEAR...A STRENGTHENING OF THE NOCTURNAL LLJ RESULTS IN SOME
CONVECTION...BUT THERE IS NO SIGN OF THIS. IN FACT...THE H85 FLOW IS
FCST TO REMAIN ACYC. SO OPTED TO FOLLOW THE DRY NAM FCST AND JUST
SHOW SOME INCRSG CLDS. THIS INCRSG MSTR SHOULD RESULT IN HIER MIN
TEMPS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 427 AM EDT MON JUL 15 2013
LARGE MID-LEVEL HIGH OVER OHIO VALLEY AND LOWER GREAT LAKES EXPANDS
WESTWARD TOWARD THE CENTRAL PLAINS THROUGH MIDWEEK. MID TO LATE WEEK
HEIGHTS FM NORTHERN PLAINS TO THE UPPER GREAT LAKES ARE FORECAST
TO LOWER AS MID-LEVEL WIND CORE SETTLES ACROSS MANITOBA AND NORTHERN
ONTARIO. GOOD MODEL AGREEMENT IN THE TREND TOWARD LOWER HEIGHTS LATE
THIS WEEK.
FIRST QUANDARY FOR THE FORECAST IS ON TUESDAY. WHAT TO DO WITH ALL
THE QPF MODELS ARE KICKING OFF. AS DISCUSSED IN THE SHORT TERM
NEGATIVE LARGER SCALE FORCING WITH RIDGE NEARBY SEEMS TO OUTWEIGH
PRIMARILY MAIN DRIVER OF MOISTURE ADVECTION. ON TUESDAY MOISTURE
ADVECTION CONTINUES BUT THERE IS ALSO WEAK TEMP ADVECTION AT H85
MAINLY OVR NORTHERN LK SUPERIOR. THOUGH THERE IS MINIMAL LK BREEZE
CONVERGENCE...POSSIBLE THAT THIS AREA OF SHRA/TSRA OVER THE LAKE WILL
EXPAND OVER PARTS OF LAND AREAS OF UPR MICHIGAN DURING PEAK HEATING
OF AFTN. COVERAGE SHOULD BE PRETTY SPARSE. JUST SLIGHT CHANCE POPS
GIVEN PRIMARY NEGATIVE LARGER SCALE FORCING AND LIMITED COVERAGE.
ANY SHRA/TSRA FM AFTN WILL CEASE EARLY WITH LOSS OF DAYTIME HEATING
AND NOT MUCH OF TRIGGER OTHERWISE. SHRA/TSRA WILL BE ONGOING CLOSER
TO APPROACHING COLD FRONT/LOW-LEVEL JET OVER SOUTHERN MANITOBA INTO
NORTHWEST ONTARIO. ISLE ROYALE COULD GET CLIPPED BUT BASED ON
WESTERLY STORM MOTION THAT SEEMS TO BE PRETTY LOW CHANCE. PRIMARY
FRONTAL PASSAGE OCCURS OVR UPR MICHIGAN LATE WEDNESDAY INTO
WEDNESDAY NIGHT AS INITIAL HEIGHT FALLS BEGIN. AT THIS POINT...THINK
WEDNESDAY PM HOLDS THE HIGHEST LIKLIHOOD OF SEEING STRONG STORMS
AND POSSIBLE SEVERE WEATHER AS THE FRONT MOVES THROUGH AND INTERACTS
WITH HIGHER END INSTABILITY WITH MLCAPES OVER 1500J/KG AND STRONGER
DEEP LAYER SHEAR OVER 30 KTS. BASED ON HIGHER SHEAR AND FAVORABLE
0-1KM SHEAR...ALL MODES OF SEVERE...INCLUDING SUPERCELLS...WOULD BE
POSSIBLE WEDNESDAY AFTN INTO WEDNESDAY EVENING.
QUESTIONS THEN ON HOW FAR SOUTH THE FRONT EVENTUALLY PROGRESSES BY
THURSDAY. MODELS HAVE TRENDED A BIT FARTHER SOUTH WITH FROPA OVER
LAST COUPLE DAYS...INDICATING THE FRONT...POSSIBLY ENHANCED BY
OUTFLOW FM THE TSRA ON WEDNESDAY...WILL SET UP MORE OVER WISCONSIN
LATER WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. IF THIS OCCURS...AND
THAT IS NOT SURE THING AS FRONT WILL STILL BE PARALLEL TO MID LEVEL
HEIGHTS...BETTER CHANCES FOR SEVERE STORMS THURSDAY WOULD LIKELY
STAY TO SOUTH OF UPR MICHIGAN. HOWEVER BEFORE THAT IF TSRA FORM
UPSTREAM IN NORTHERN MINNESOTA ON WEDNESDAY AFTN/EVENING THERE IS
ADDITIONAL POTENTIAL FOR STRONGER TSRA WITH A WIND THREAT LATE
WEDNESDAY NIGHT OVR MUCH OF UPR MICHIGAN BASED ON H85-H3 THICKNESSES
AND GRADIENT OF HIGHER MUCAPE OVER UPR MICHIGAN. SINCE UPR MICHIGAN
WOULD THEN BE ON THE COOLER SIDE OF THE FRONT ON THURSDAY AND THERE
IS ABUNDANT MOISTURE INTERSECTING THE FRONT WITH PWATS NEARING 200
PCT OF NORMAL AND THERE ARE SHORTWAVES MOVING THROUGH IN WNW FLOW
ALOFT ACROSS MANITOBA AND ONTARIO...SEEMS LIKELY THAT COULD SEE
WIDESPREAD SHRA/TSRA ACROSS MUCH OF THE AREA ON THURSDAY. HEAVY
RAIN WOULD BE POSSIBLE WITH SUCH ABUNDANT MOISTURE. CONSENSUS OF
MODELS INDICATES LIKELY POPS THURSDAY INTO THURSDAY NIGHT WHICH
FITS THIS PATTERN PRETTY WELL. GIVEN POTENTIAL FOR A LOT OF
CLOUDS/FOG AND WIDESPREAD PRECIP ON THURSDAY IN ADDITION TO ONSHORE
FLOW DEVELOPING OFF LK SUPERIOR...HAVE LOWERED TEMPS ACROSS THE CWA.
GOOD AGREEMENT THAT COOLER NORTH FLOW KICKS IN BY FRIDAY AND
CONTINUES THROUGH SATURDAY. NO REAL CHANGE TO GOING FCST/CONSENSUS
WITH HIGHS STRUGGLING IN THE 60S NEAR LK SUPERIOR BOTH FRIDAY AND
SATURDAY. HIGHS AWAY FM LK SUPERIOR WILL BE IN THE 70S/LOWER
80S...COOLEST ON SATURDAY BEHIND SECONDARY RE-INFORCING COLD FRONT.
WARMER TEMPS BEGIN TO RETURN BY SUNDAY ALONG WITH A SMALL CHANCES
OF SHRA/TSRA DUE TO WARM AIR ADVECTION.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 129 PM EDT MON JUL 15 2013
WITH HIGH PRESSURE IN PLACE OVER UPPER MICHIGAN...EXPECT VFR
CONDITIONS THROUGH MOST OF THE TAF PERIOD. THE ONLY CONCERN FOR
TONIGHT WILL BE POTENTIAL FOR FOG DEVELOPMENT. THOUGH THERE WILL BE
ABUNDANT LL MOISTURE AND LIMITED CLOUD COVER TONIGHT...FOG MAY NOT
DEVELOP BECAUSE OF MORE PRONOUNCED SOUTHERLY WIND FLOW. STILL FELT
CONFIDENT ENOUGH TO PLACE IN TAF. ONLY HAVE HIGH END-MVFR
VISIBILITIES AS IT WILL NOT LIKELY DROP TO LESS THAN 3 MILES LIKE
LAST NIGHT BECAUSE OF THE SLIGHTLY STRONGER WINDS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 427 AM EDT MON JUL 15 2013
WITH A WEAK PRESSURE GRADIENT AND STABLE AIR OVER THE COOL WATERS OF
LAKE SUPERIOR...EXPECT WINDS TO REMAIN LESS THAN 20 KNOTS THROUGH
THE FORECAST PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JLA
AVIATION...MCD
MARINE...KC
AREA FORECAST DISCUSSION
NWS BILLINGS MT
315 PM MDT MON JUL 15 2013
.SHORT TERM...VALID FOR TUE AND WED...
I WILL FOCUS ON THIS EVENINGS WEATHER FOR THE MOST PART OF THIS
DISCUSSION DUE TO A THREAT OF SEVERE WEATHER. THE THREAT IS MAINLY
ALONG THE MONTANA/DAKOTA BORDERS REGION. THE OTHER SIGNIFICANT
WEATHER FEATURE THROUGH THE NEXT 48 HOURS IS A BRISK COLD FRONT
EXPECTED TONIGHT.
CURRENTLY...THERE IS CONVECTION ALONG THE CONVERGENCE AREA OF A
SURFACE TROUGH EXTENDING SOUTH ACROSS CUSTER COUNTY DOWN INTO
NORTH CENTRAL WYOMING. THIS CONVERGENCE REGION WILL SLOWLY SHIFT
EAST WITH TIME AS A COLD FRONT APPROACHES FROM THE NORTHWEST. AT
THE SAME TIME WE HAVE A WEAK SHORT WAVE IN THE SW FLOW ALOFT WHICH
WILL RIDE OVER THIS SURFACE TROUGH. THE GFS AND NAM ARE NOT VERY
BULLISH ON CONVECTIVE DEVELOPMENT...BUT THE HRRR UNZIPS A STRONG
LINE OF CONVECTION ALONG THE SURFACE TROUGH AND PUSHES IT EAST
INTO A RICH ENVIRONMENT WITH DEWPOINTS IN THE 60S ALONG THE
EASTERN STATELINE. IN THE SAME AREA WE HAVE A STRONGLY SHEARED
ENVIRONMENT. THIS ALL AMOUNTS TO A RISK OF SEVERE WEATHER ALONG
OUR EASTERN BORDER COUNTIES LATE TODAY THROUGH EARLY EVENING.
PRECIP WATER VALUES ARE WELL OVER AN INCH...SO ALONG WITH LARGE
HAIL AND DAMAGING WIND ANY STORMS COULD PRODUCE VERY HEAVY
RAINFALL AS WELL. AS THE FORCING FROM THE SHORT WAVE DRIFTS
NORTHEAST THE CONVECTION WILL SHIFT EAST AFTER MID EVENING.
WE THEN HAVE WHAT APPEARS TO BE A SHARP COLD FRONT MOVING IN FROM
THE NW OVERNIGHT. PRESSURE RISES ARE ON THE ORDER FROM 9 TO 13 MB
PER 6 HRS DEPENDING ON WHAT PROGG YOU LOOK AT. THIS IS A PRETTY
DECENT RIDGE CRASHING FRONT. AS A FRAME OF REFERENCE...THE FRONTAL
PASSAGE IS EXPECTED THROUGH BILLINGS AROUND MIDNIGHT. BUFKIT MIXES
SOME 20 TO 30 KT WINDS TO NEAR THE SURFACE. I EXPECT RIDGE TOPS TO
BE RATHER BREEZY BEHIND THE FRONT OVERNIGHT. THIS IS PRIMARILY A
FIRE WEATHER CONCERN AND WILL BE HIGHLIGHTED IN FIRE WEATHER
PRODUCTS.
LOOK FOR MUCH COOLER TEMPERATURES TUESDAY WITH SHOWERS POSSIBLE IN
THE EAST EARLY...SWITCHING TO THE WEST LATER IN THE DAY. BT
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
LITTLE IN THE WAY OF CHANGES FOR THE EXTENDED PERIOD FORECAST
THIS AFTERNOON...WITH MODELS IN FAIR AGREEMENT. MODELS SEEM TO
DIFFER A BIT ON STRENGTH AND IMPACTS OF MONSOONAL FLOW INTO THE
REGION...BUT GOING FORECAST SEEMS A GOOD REPRESENTATION WITH MINOR
DISCREPANCY.
SFC MOISTURE SHOULD REMAIN IN PLACE ACROSS THE REGION...WITH
RELATIVELY DEEP EASTERLY FLOW AT LOW LEVELS. ADDITIONALLY
MONSOONAL MOISTURE AT MID LEVELS WILL CONTINUE TO PUSH INTO THE
AREA KEEPING PWATS OVER AN INCH IN MOST AREAS. ALTHOUGH THE FLOW
IS MORE WESTERLY ALOFT...MULTIPLE SHORTWAVES THROUGH FRIDAY
SHOULD KEEP POTENTIAL FOR CONVECTION IN PLACE...ESPECIALLY IN THE
HIGH TERRAIN...AS UPSLOPE FLOW IMPROVES DURING THE DAY. STRONG TO
SEVERE COULD BE POSSIBLE...WITH POTENTIAL SHEAR VALUES...WHICH
HAVE BEEN IMPROVING RECENTLY. EXPECT SEASONAL TYPE TEMPS FOR
THURSDAY AND FRIDAY...AS HIGHS CLIMB TO AROUND 90 DEGREES.
SHALLOW UPPER LEVEL RIDGING AND SHIFTING OF MONSOONAL FLOW
EASTWARD...OUT OF THE AREA...SHOULD LEAD TO DRIER AND WARMER
CONDITIONS ON TAP FOR SATURDAY AND SUNDAY...WITH TEMPS BACK INTO
THE MID 90S IN MOST AREAS FOR THE WEEKEND. AAG
&&
.AVIATION...
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED THROUGH THIS
EVENING...ESPECIALLY EAST OF A LINE FORM KMLS TO KSHR. SOME MAY BE
SEVERE. WINDS WILL BE GENERALLY LIGHT ACROSS THE WEST THROUGH THE
DAY...WITH SOUTHEASTERLY WINDS AROUND 15 KNOTS EAST OF A LINE FROM
FORSYTH TO KSHR. A STRONG COLD FRONT WILL MOVE THROUGH THE REGION
AROUND MIDNIGHT...BRINGING MORE THUNDERSTORMS ACROSS THE REGION
OVERNIGHT AS WELL AS STRONG AND GUSTY NORTHWEST WINDS...AND MUCH
COOLER TEMPERATURES FOR TUESDAY. VFR CONDITIONS WILL PREVAIL...BUT
LOCAL/BRIEF MVFR IS POSSIBLE WITH ANY STORMS THAT DEVELOP. ERRATIC
GUSTY WINDS CAN BE EXPECTED AROUND THUNDERSTORMS. AAG
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 063/082 062/089 063/091 064/091 064/094 065/095 065/093
21/B 22/T 32/T 32/T 21/B 11/B 11/U
LVM 054/082 054/090 056/090 055/092 052/095 052/096 052/093
22/T 24/T 43/T 32/T 21/B 11/B 11/B
HDN 063/084 061/091 062/092 061/093 059/095 061/097 061/094
22/T 02/T 32/T 32/T 21/B 11/B 11/U
MLS 066/087 063/092 067/093 066/093 066/094 066/095 066/092
32/T 12/T 22/T 21/B 11/U 11/U 11/U
4BQ 062/088 060/093 062/091 065/090 060/092 060/094 060/093
32/T 01/B 12/T 22/T 21/B 11/U 11/U
BHK 061/087 058/089 062/090 064/088 062/089 061/092 061/087
32/T 12/T 22/T 21/B 12/T 21/U 11/U
SHR 059/085 059/092 059/090 058/090 057/092 057/095 057/092
22/T 12/T 23/T 33/T 31/B 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...TORNADO WATCH 415 IN EFFECT UNTIL 11 PM MDT THIS EVENING FOR
ZONES 33-37.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1249 PM CDT MON JUL 15 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 325 AM CDT MON JUL 15 2013
FORECAST CHALLENGES IN THE NEAR TERM ARE TEMPERATURES AND ENDING
TIME OF PRECIPITATION THIS MORNING. FOR TODAY...UPPER LEVEL LOW
PRESSURE WILL TRACK ALONG THE TX/OK BORDER. MID LEVEL WAA WILL
SHIFT NORTHWEST INTO THE NEBRASKA PANHANDLE AND SOUTH DAKOTA BY
MID MORNING...ENDING PRECIPITATION ACROSS THE FORECAST AREA. THE
NAM...GFS...AND HI RES RUC ALL SHIFT THIS MID LEVEL LIFT WEST...SO
CONFIDENCE IS FAIRLY HIGH IN ENDING PCPN MENTION BY MID MORNING.
DRY CONDITIONS WILL CARRY OVER INTO THE OVERNIGHT HOURS
TONIGHT...AS DRIER...MORE STABLE AIR PUSHES INTO WESTERN AND NORTH
CENTRAL NEBRASKA. TEMPERATURES TODAY WILL RANGE FROM THE LOWER 80S
IN THE WEST WITH MORE PERSISTENT CLOUD COVER...TO THE MIDDLE AND
UPPER 80S IN THE CENTRAL AND EASTERN FORECAST AREA...WITH MAINLY
CLEAR SKIES EXPECTED. WINDS WILL BE FROM THE SOUTH AND SOUTHEAST
AT 10 TO 20 MPH...DECREASING TO 10 TO 15 MPH TONIGHT. WITH MUCH
DRIER AIR PUSHING INTO THE REGION TODAY...OVERNIGHT LOWS WILL
BOTTOM OUT IN THE UPPER 50S IN THE WEST TO MID 60S IN THE EAST.
THE ONLY CAVEAT TO LOWS TONIGHT WILL BE WHETHER OR NOT WINDS WILL
TOTALLY DECOUPLE. THIS MAY BE AN ISSUE ACROSS NORTH CENTRAL
NEBRASKA WHERE H85 AND H925 WINDS REMAIN UNIDIRECTIONAL INTO THE
OVERNIGHT. WITH THIS IN MIND...HEDGED LOWS A LITTLE WARMER ACROSS
NORTH CENTRAL NEBRASKA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 325 AM CDT MON JUL 15 2013
EXPANSIVE UPPER LEVEL AREA OF HIGH PRESSURE WILL BE ANCHORED
ACROSS THE OHIO RVR VALLEY /LOWER GREAT LAKES REGION STARTING OFF
THE EXTENDED PERIOD AS A FILLING UPPER LOW CONTINUES TO RETROGRADE
SOUTHWEST ACROSS WESTERN TEXAS. WITH INCREASING SUBSIDENCE AND
RISING HEIGHTS...TEMPERATURES WILL CONTINUE TO WARM MID WEEK WITH
WIDESPREAD 90S ANTICIPATED WEDNESDAY AND ESPECIALLY THURSDAY FOR
ALL LOCATIONS ACROSS WESTERN AND NORTH CENTRAL NEBRASKA.
LOWS...UNDER MOSTLY CLEAR SKIES...SHOULD BE SEASONAL WITH 60S
PREVAILING FOR MOST LOCATIONS. BEYOND THURSDAY...MODELS REMAIN
CONSISTENT WITH THE PASSAGE OF A SHORTWAVE ACROSS THE NORTHERN
PLAINS...WHICH WILL FORCE A COLD FRONT THROUGH THE CWA ON FRIDAY.
HIGHS ARE ANTICIPATED TO BE A COUPLE TO SEVERAL DEGREES
COOLER...WITH MAINLY 80S AND LOW 90S EXPECTED. IT SEEMS THAT WITH
EACH SUCCESSIVE MODEL RUNS...QPF COVERAGE ASSOCIATED WITH THE
SHORTWAVE AND COLD FRONTAL PASSAGE IS BECOMING LESS AND
LESS...THUS WILL ONLY MAINTAIN SLIGHT CHANCES/LOW END CHANCES OF
POPS FRIDAY THROUGH EARLY SATURDAY...WITH THE HIGHEST PROBABILITY
OCCURRING ALONG OUR SOUTHERN BORDER FRIDAY EVENING AS THE FRONT
SAGS SOUTH. INTO THE WEEKEND...THERE REMAINS SOME CONSISTENCY IN
THE OPERATIONALS THAT THE FRONT WILL STALL TO THE SOUTH OF THE
CWA...WITH ADDITIONAL DISTURBANCES PASSING THROUGH NORTHWESTERLY
FLOW ALOFT. A THREAT OF STORMS WILL REMAIN THROUGH THE COMING
WEEKEND...HOWEVER SHEAR VALUES AT THIS TIME LOOK FAIRLY
WEEK...WIDESPREAD SEVERE WEATHER IS NOT ANTICIPATED IF STORMS
ACTUALLY ARE REALIZED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1246 PM CDT MON JUL 15 2013
CUMULUS CLOUDS WILL DISSIPATE THIS EVENING WITH THE LOSS OF
DAYTIME HEATING. VFR CONDITIONS WILL RULE...WITH SOUTH TO
SOUTHEAST SFC WINDS OCCASIONALLY GUSTING TO 20 KTS THIS
AFTERNOON...AND HOLD STEADY NEAR 10 KTS TONIGHT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CLB
LONG TERM...JACOBS
AVIATION...TAYLOR
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1212 PM CDT MON JUL 15 2013
.DISCUSSION...
LEFT IN A 20/30 PERCENT CHANCE FOR CONVECTION FOR THE AFTERNOON
AS WE CONTINUE TO WARM. THERE IS A WEAK CAP IN PLACE THAT WE WILL
HAVE TO OVERCOME. NAM/RAP MODELS SUGGEST BEST CHANCE MIGHT EXIST
BETWEEN KOMA/KSUX. HRRR SEEMS OVERDONE AS IT MAY JUST BE PICKING
UP ON THE CU FIELD THAT HAS DEVELOPED.
&&
.AVIATION...18Z TAFS FOR KOMA...KLNK AND KOFK. VFR CONDITIONS
EXPECTED THROUGH THE PERIOD. SOME CUMULUS CLOUDS WILL AFFECT THE
REGION THROUGH EARLY EVENING...BUT THEN SHOULD DISSIPATE BY
SUNSET. WHILE THERE IS A SMALL CHANCE THAT CONVECTION COULD
DEVELOP ACROSS EASTERN NEBRASKA/WESTERN IOWA...WILL NOT SPECIFICALLY
PUT IT IN THE FORECAST AT THIS TIME SINCE IT MAY BE NORTH OF THE
KOMA TAF SITE.
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON JUL 15 2013/
DISCUSSION...
TEMPERATURES THROUGH THE WEEK AND THE CHANCE FOR TSTMS FOR TODAY
INTO EARLY THIS EVENING ARE THE PRIMARY FORECAST CONCERNS. UNUSUAL
UPPER LEVEL PATTERN WITH RETROGRESSIVE MID TROPOSPHERIC FLOW WILL
CONTINUE INTO MID WEEK.
CURRENT AIRMASS OVER THE AREA IS MUCH DRIER THAN 24 HOURS AGO. AT
12Z SUNDAY THE PRECIPITABLE WATER AMOUNT FROM THE KOAX SOUNDING WAS
1.80 INCHES. THAT DROPPED TO 1.03 BY 00Z MONDAY. THAT WILL BE
CHANGING AS MOISTURE MOVES BACK INTO THE AREA FROM THE SOUTHEAST.
MOST OF THE SHORT RANGE MODEL DEVELOP SOME LIGHT PCPN OVER AT
LEAST PORTIONS OF THE FORECAST AREA FROM THIS AFTERNOON INTO THE
EARLY EVENING. NAM AND RAP SHOW SOME CAPE (500-1500 J/KG)
DEVELOPING THIS AFTERNOON AND CONTINUING INTO THE EVENING.
AFTER THIS EVENING...KEPT A DRY FORECAST UNTIL LATE IN THE WEEK.
ALTHOUGH CAN NOT COMPLETELY RULE OUT SOME ISOLD LATE AFTERNOON POP
SHOWERS/THUNDERSTORMS TUESDAY OR WEDNESDAY...FELT COVERAGE WOULD
JUST BE TOO LOW TO MENTION AT THIS POINT. WILL NEED TO LOOK AT THAT
THOUGH THE NEXT SEVERAL FORECAST CYCLES.
THE CLOSED LOW INITIALLY OVER OKLAHOMA TODAY WILL MOVE INTO EASTERN
NEW MEXICO TUESDAY AND THEN INTO THE NORTHERN PART OF SONORA MEXICO
ON THURSDAY. FAIRLY HIGH 500 MB HEIGHTS FAVOR WARM TEMPERATURES AND
MAINLY DRY CONDITIONS. THE LARGE MID/UPPER TROPOSPHERIC RIDGES DOES
START TO FLATTEN THURSDAY NIGHT/FRIDAY...WHICH WILL ALLOW A WEAK
COLD FRONT TO SAG SOUTH INTO THE AREA FRIDAY/SATURDAY. THIS SHOULD
BRING A DECENT CHANCE OF PCPN. TEMPERATURES WILL BE MAINLY IN THE
90S IN THE MID AND LATER PART OF THE WEEK WITH SLIGHT COOLING FOR
THE WEEKEND.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
400 PM EDT MON JUL 15 2013
.SYNOPSIS...
A SPRAWLING AREA OF HIGH PRESSURE WILL STAY IN POSITION OVER THE
REGION THROUGH FRIDAY...PROVIDING ABOVE-NORMAL TEMPERATURES. ON
FRIDAY NIGHT AND INTO SATURDAY...A COLD FRONT WILL MOVE SOUTH FROM
THE GREAT LAKES...PASSING THROUGH THE OHIO VALLEY. THIS WILL
PROVIDE A CHANCE OF SHOWERS AND STORMS. WITH HIGH PRESSURE
BUILDING IN BEHIND THE FRONT...SLIGHTLY COOLER AND DRIER
CONDITIONS ARE EXPECTED FOR SUNDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
WITH HIGH PRESSURE PROVIDING GENERALLY TRANQUIL (THOUGH WARM)
CONDITIONS ACROSS THE CWA TODAY...THE ONLY SIGNIFICANT FORECAST
QUESTION FOR TONIGHT IS THE POSSIBILITY OF A POP-UP SHOWER OR
THUNDERSTORM. CONVECTION IS DEVELOPING FAIRLY READILY ALONG AND
NORTH OF THE MICHIGAN BORDER...AND A FEW LIGHT ECHOES HAVE BEEN
OBSERVED JUST A COUPLE COUNTIES NORTH OF THE ILN CWA IN OHIO. LAPS
DATA SUGGESTS A FAIRLY UNIFORM FIELD OF AROUND 1500-2000 J/KG
CAPE (SURFACE BASED) ACROSS THE CWA...WITH SLIGHTLY MORE FURTHER
NORTH. WIND FLOW IS VERY LIGHT AND THERE IS VERY LITTLE IF ANY
FORCING...AND THERE IS ALSO A BIT OF INHIBITION (AS ALSO SUGGESTED
WITH A SMALL CAP ON RAP SOUNDINGS). THE FORECAST WILL CARRY A 10
PERCENT CHANCE OF A SHOWER OR STORM CWA-WIDE (10-POPS DO NOT SHOW
UP IN THE TEXT PRODUCTS) WITH A SLIGHT CHANCE IN THE FAR
NORTH...CLOSER TO THE SLIGHTLY HIGHER INSTABILITY AND A REALLY
SLIGHT AMOUNT OF 850MB CONVERGENCE IN THE TURNING FLOW AROUND THE
CENTER OF THE HIGH.
MIN TEMPS ARE NOT FAR FROM PERSISTENCE FROM LAST NIGHT...PERHAPS A
DEGREE OR TWO WARMER AS THE AIR MASS GRADUALLY ADJUSTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE CENTER OF THE LARGE STACKED HIGH PRESSURE AREA WILL PARK
ITSELF OVER THE ILN CWA ON TUESDAY...REMAINING IN PLACE BEFORE IT
IS FINALLY SUPPRESSED ON FRIDAY. THE HEIGHTS ASSOCIATED WITH THIS
HIGH ARE POSSIBLY HISTORIC...BUT THE HEAT (THOUGH WELL ABOVE
NORMAL) IS NOT. 850MB TEMP ANOMALIES PEAK OUT AT ABOUT ONE
STANDARD DEVIATION ABOVE NORMAL OVER THE NEXT FEW DAYS.
HOWEVER...500MB HEIGHT ANOMALIES ARE EXPECTED TO BE TWO TO TWO AND
A HALF STANDARD DEVIATIONS ABOVE NORMAL. DESPITE THE STRENGTH OF
THE HIGH...MOIST CONDITIONS ARE ONE FACTOR KEEPING THE HEAT
DOWN...AND PROVIDING CUMULUS DEVELOPMENT AND A SLIM CHANCE FOR A
SHOWER OR STORM ON JUST ABOUT EVERY DAY THIS WEEK.
LOOKING AT PRECIPITATION CHANCES...WEAK TO ALMOST NON-EXISTENT
FORCING WILL KEEP THE THREAT FOR ORGANIZED STORMS AWAY UNTIL THE
WEEKEND. INSTABILITY WILL DRIVE ANYTHING THAT DEVELOPS OVER THE
NEXT FEW DAYS...AS CAPE VALUES CLIMB TO AROUND 2000 J/KG
(POTENTIALLY AS HIGH AS 3000 J/KG) TUESDAY AND WEDNESDAY. THE SREF
FAVORS CONVECTIVE POTENTIAL TUESDAY FROM LOWER MICHIGAN SSE TOWARD
LAKE ERIE...AND PERHAPS AS FAR SOUTH AS CENTRAL OHIO. A 20-POP
WILL BE USED IN THE NORTHEAST HALF OF THE CWA. WEDNESDAY...AS THE
CENTER OF THE HIGH SLOWLY DRIFTS WEST...CONDITIONS WILL BE A
LITTLE MORE FAVORABLE CWA-WIDE (WITH UP TO A 30 PERCENT CHANCE IN
THE FAR EASTERN CWA). THE EXPECTATION ON EACH DAY IS TYPICAL FOR
THIS SORT OF PATTERN...WITH SPARSE COVERAGE...SLOW
MOTIONS...DOWNPOURS AND GUSTY WINDS.
AS OF NOW...IT LOOKS LIKE THE HEAT (THROUGH WEDNESDAY) WILL HOLD
OFF JUST SHY OF ADVISORY CRITERIA. WITH 925MB TEMPS IN THE 22C-24C
RANGE...AND 850MB TEMPS IN THE 18C-19C RANGE...SURFACE TEMPS OF
AROUND 90 TO THE LOWER 90S ARE SUPPORTED. DEWPOINTS IN THE LOWER
70S (APPROACHING MID-70S BY WEDNESDAY) ARE EXPECTED...WHICH SHOULD
ALLOW FOR HEAT INDICES IN THE MIDDLE TO UPPER 90S. A FEW LOCATIONS
WILL PROBABLY BRIEFLY MAKE IT TO AROUND 100 FOR A HEAT INDEX...BUT
THIS IS NOT EXPECTED TO BE WIDESPREAD. THE LACK OF WIND MAY MAKE
CONDITIONS RATHER UNCOMFORTABLE...BUT MIXING POTENTIAL MAY ONLY BE
TO AROUND 850MB (THERE DOES NOT SEEM TO BE MUCH SUPPORT IN THE
FORECAST SOUNDINGS FOR ANYTHING HIGHER THAN THAT). MIN TEMPS WERE
RAISED A DEGREE OR TWO FOR TUESDAY AND WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
COMPUTER MODELS ARE IN GOOD AGREEMENT THROUGH SATURDAY NECESSITATING
FEW CHANGES TO THE GOING FORECAST.
VERTICALLY STACKED HIGH PRESSURE STRETCHING FROM THE CENTRAL PLAINS
TO THE CENTRAL APPALACHIANS WILL CONTINUE TO DOMINATE ON THURSDAY.
A TROUGH MOVING ACROSS HUDSON BAY WILL ACT TO BEGIN SUPPRESSING THE
RIDGE...HOWEVER LOW LEVEL THERMAL PROFILES WILL CONTINUE TO SUPPORT
HIGH TEMPERATURES IN THE LOWER 90S AREA-WIDE. DEW POINTS IN THE
LOWER 70S WILL BRING ANOTHER DAY WITH HEAT INDICES NEAR OR POSSIBLY
EXCEEDING 100F. A STRAY THUNDERSTORM WILL BE POSSIBLE IN THIS
AIRMASS...ALTHOUGH THE LACK OF FORCING AND AT LEAST SOME CAPPING IN
PLACE SUGGEST MODEL QPF OUTPUT IS PROBABLY OVERDONE.
ON FRIDAY...UPPER HEIGHTS WILL BEGIN FALLING AS A VIGOROUS TROUGH
BEGINS DIVING THROUGH CENTRAL CANADA. A LITTLE HIGHER COVERAGE OF
THUNDERSTORMS MAY RESULT...AND WE WILL HAVE TO WATCH OUR NORTHERN
COUNTIES TO SEE WHAT EVOLVES FROM WHAT COULD BE AN ACTIVE WEATHER
DAY OVER THE GREAT LAKES. HIGH TEMPERATURES WILL STILL REACH THE 90S
FOR MANY...ALTHOUGH THE HEAT INDEX MAY BE A FEW DEGREES LOWER.
A COLD FRONT WILL DROP SOUTHWARD INTO THE AREA ON SATURDAY...LEADING
TO A FAIRLY HIGH CHANCES OF PRECIPITATION. OBVIOUSLY THIS FAR OUT
THE CONVECTIVE EVOLUTION REMAINS IN QUESTION THOUGH. SPC HAS
HIGHLIGHTED AREAS TO OUR NORTH (DAY 5/FRIDAY) AND EAST (DAY
6/SATURDAY) FOR SEVERE WEATHER...AND THIS COINCIDES WITH HIGHER WIND
SHEAR VALUES. HOWEVER...IT IS CERTAINLY POSSIBLE THE COLD FRONT
COULD BRING STRONG TO SEVERE STORMS TO OUR AREA AS WELL ON SATURDAY.
CONFIDENCE IS LOW ENOUGH TO LEAVE OUT OF THE HWO FOR NOW.
TEMPERATURES ON SATURDAY WILL BE TRICKY DEPENDING ON PRECIPITATION
TIMING.
EVEN THOUGH UPPER LEVEL HEIGHT PATTERNS ARE FAIRLY CONSISTENT...
THERE HAS BEEN DISAGREEMENT BETWEEN MODELS AND MODEL RUNS ON HOW FAR
SOUTH THE LOW LEVEL COLD FRONT WILL MAKE IT LATE IN THE WEEKEND.
GIVEN THE FRONT IS SOMEWHAT PARALLEL TO THE UPPER FLOW...FELT IT WAS
PRUDENT TO LINGER SOME POPS IN THE SOUTH FOR SUNDAY. RIGHT
NOW...HIGH PRESSURE TO THE NORTH APPEARS STRONG ENOUGH TO PROVIDE
DRY WEATHER FOR MONDAY. AFTER THE FRONT PASSES...TEMPERATURES WILL
RETURN CLOSER TO SEASONAL NORMALS (HIGHS IN LOWER TO MID 80S...LOWS
IN MID 60S).
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL PREVAIL AS DAYTIME CU DEVELOPMENT RAPIDLY CUTS
OFF WITH THE COMING OF NIGHT. CLEAR SKIES AND LIGHT WINDS SHOULD
ALLOW FOR SOME PREDAWN OBSERVATIONS OF BR...GENERALLY LIGHT.
FAIR WX CU ARE EXPECTED AGAIN TOMORROW AS HIGH PRESSURE CONTINUES
TO GIVE A GENERAL DOWNWARD MOTION TO THE REGION.
OUTLOOK...NO SIGNIFICANT WEATHER EXPECTED.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...SNYDER
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
147 PM EDT MON JUL 15 2013
.SYNOPSIS...
HIGH PRESSURE BRINGS ABOVE NORMAL TEMPERATURES THROUGH MUCH OF THE
WORK WEEK. A COLD FRONT SAGS SLOWLY SOUTHWARD TOWARD THE AREA NEAR
THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
UPDATE...
NO CHANGES TO THE LATEST FORECAST.
PREVIOUS DISCUSSION...
MODELS ARE SHOWING A BIT OF MID LEVEL MOISTURE MOVING INTO THE
REGION FROM THE SOUTHEAST TODAY. THIS SEEMS TO BE VALID BASED ON AN
AREA OF SHOWERS AND CLOUDS CURRENTLY IN SOUTHERN VA. BIG PROBLEM IS
THE EXTENT OF THE MOISTURE AND EXACTLY WHERE IT ENDS UP THIS
AFTERNOON. THIS IS WHERE THE MODELS DIFFER. RUC IS A BIT MORE
GENEROUS WITH THE MOISTURE...WHILE NAM KEEPS IT MORE
CONCENTRATED...AND GFS IS LEAST GENEROUS WITH IT. THIS FEATURE WAS
IN AN AREA WITHOUT SOUNDINGS AT 00Z...SO NOT SURPRISED BY MODEL
DIFFERENCES. HRRR ALSO SHOWS SOME SHOWERS IN THE WESTERN LOWLANDS
THIS AFTERNOON. DUE TO MODEL DIFFERENCES...WILL GO WITH A GENERIC
SLIGHT CHANCE.
MOS GUIDANCE FOR HIGHS TODAY SEEMS A BIT TOO WARM BASED ON THE AREA
STILL BEING FAIRLY WET. WILL UNCUT SLIGHTLY.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
UPR RIDGE AXIS WILL GRADUALLY SHIFT W OF THE AREA IN THE SHORT TERM
PERIODS. IT APPEARS THERE WILL BE SOME MOISTURE THAT ADVECTS IN FROM
NE AS IT DOES SO. AS SUCH...APPEARS MORE LIKE A TYPICAL DIRTY RIDGE
ARND THESE PARTS WHICH WILL ALLOW FOR DAILY AFTN/EVE THREAT FOR
SHRA/TSRA. WENT WITH COVERAGE WORDING IN WX GRIDS. THINK THESE
INITIALLY FIRE ACROSS THE MTNS...AIDED BY SOME TERRAIN INDUCED
CONVERGENCE. FEEL CAP HOLDS ON TUE W OF THE MTNS EXCEPT ACROSS N
LOWLANDS AND PORTIONS OF SE OH WHERE SOME SCHC POPS WERE MAINTAINED.
HAVE LOW CHC IN THE MTNS TUE AFTN/EVE. WED MDLS ARE TRYING TO
INDICATE AFTN MTN CONVECTION SLIDES OFF THE RIDGES INTO THE CENTRAL
LOWLANDS. STORM MOTIONS OFF MDLS SUPPORT THIS AND PERHAPS AIDED BY
COLD POOL PROPAGATION. NAM IN PARTICULAR ALLOWS THIS TO REACH INTO
COAL FIELDS AND KANAWHA VALLEY LATE WED AFTN. PREV FCST SEEMED TO
REFLECT THIS GENERAL THINKING AND ONLY SOME TWEAKS TO POPS TO ALLOW
W PENETRATION WAS NEEDED. HOLD IN CHC RANGE FOR NOW WITH THIS.
ELSEWHERE KEEP IT DRY. SAME GENERAL IDEA HOLDS FOR THU AS
WELL...WITH MTN CONVECTION PERHAPS SLIDING OFF THE HILLS INTO THE
CENTRAL LOWLANDS. THESE MAY BE SLOW TO DIE OFF AFTER SUNSET...HENCE
KEEP SOME SCHC IN UNTIL ARND 05Z. ANY STORMS THAT FIRE TUE-THU
COULD BE ON THE STRONG SIDE GIVEN CAPE BUILDUP EXPECTED. WIND WOULD
BE THE CONCERN AND HEAVY DOWNPOURS.
AS FOR TEMPS...FEEL MAV IS TOO WARM ACROSS THE LOWLANDS AND HEDGED
TOWARD COOLER MET. THIS RESULTS IN GENERALLY LWR 90S OUTSIDE OF THE
MTNS. DWPTS 70 TO 72F WILL PRODUCE HEAT INDICES IN THE MID TO UPR
90S TUE...PUSHING 100 WED AND THU OUTSIDE OF THE MTNS. A HEAT ADV
MAY BE NEEDED FOR WED AND THU. WILL PUT A MENTION IN HWO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
UPPER RIDGE GRADUALLY FLATTENS THIS PERIOD...ALLOWING EASTERN
CANADIAN TROUGHING TO GRADUALLY SETTLE S INTO THE NERN CONUS. THIS
DRIVES A COLD FRONT SWD TOWARD THE AREA AS EARLY AS FRI NT...AND
GRADUALLY INCREASES THE CHANCE FOR SHOWERS AND THUNDERSTORMS GOING
INTO NEXT WEEKEND...ESPECIALLY LATE DAY. HAVE THE FRONT PUSHING ON
THROUGH SUN / SUN NT THOUGH THIS WILL DEPEND UPON HOW DEEP THE NE
CONUS TROUGH GETS.
BLENDED IN A LITTLE OF ADJMEXBC ON HIGHS FOR SLIGHTLY HIGHER VALUES
AND USED PREVIOUS/ADJMEXBC/WPC BLEND ON LOWS WITH LITTLE CHANGE OR
SLIGHTLY HIGHER VALUES THERE.
&&
.AVIATION /17Z MONDAY THROUGH FRIDAY/...
VFR THROUGH TODAY UNDER DOMINANT HIGH PRESSURE ALOFT. HIT THE
IFR/LIFR CONDITIONS A LITTLE HARDER TONIGHT BASED ON CONSENSUS
GUIDANCE FROM THE MET/MAV/LAMP. SOME CONFIDENCE LACKS HOWEVER DUE
TO VERY HIGH DEWPOINTS. EXPECT THE WIND TO GO CALM LATE THIS
EVENING AND TONIGHT.
MAY HAVE A SHOWER NEAR BKW TODAY...BUT NOT ENOUGH OF A CHANCE TO
WARRANT SHRA IN THE PREVAILING...OR VCSH FOR THAT MATTER.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: HIGH TODAY...MEDIUM TO HIGH TONIGHT.
ALTERNATE SCENARIOS: LOCATION OF THUNDERSTORMS THIS AFTERNOON
COULD VARY. NOT SOLD ON IFR CHANCES TONIGHT...AND LATE TEMPOS MAY
BE A BETTER BET.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY H H H H H H H H H H H H
PKB CONSISTENCY H H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
NO IFR CONDITIONS EXPECTED.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...RPY/26
SHORT TERM...30
LONG TERM...TRM
AVIATION...26
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1232 PM CDT MON JUL 15 2013
.DISCUSSION...
SEE AVIATION FOR 18Z TAF DISCUSSION.
&&
.AVIATION...
DIFFICULT FORECAST THIS AFTERNOON WITH REGARDS TO PRECIPITATION
COVERAGE AND TIMING. ACTIVITY HAS DIMINISHED ACROSS MUCH OF THE
REGION EXCEPT FOR AN AREA EAST OF GALVESTON BAY. THIS ACTIVITY
LOOKS TO REMAIN EAST OF THE MAIN TAF CORRIDOR FOR THE NEXT FEW
HOURS SO WILL MAINLY CARRY VCSH FOR AREA SITES. GIVEN THE LOW
CONFIDENCE IN EXACT TIMING HAVE HELD OFF ON ANY TEMPO GROUPS FOR
NOW. OTHERWISE ONLY MAJOR CHANGE TO THE PREVIOUS TAF WAS TO REMOVE
THE MENTION OF FOG FOR THE EARLY MORNING HOURS. EXPECTED OVERCAST
HIGH CLOUDS SHOULD ACT TO LIMIT THE THREAT FOR FOG TONIGHT. IF
BREAKS CAN DEVELOP IN THE HIGH COVER THEN FOG THREAT MAY BE
INCREASED. 38
&&
.PREV DISCUSSION... /ISSUED 1041 AM CDT MON JUL 15 2013/
UPDATE...
MORNING FORECAST UPDATE.
DISCUSSION...
AREA RADAR SHOWING A BROAD SHIELD OF PRECIP OVER C TX INTO THE
BRAZOS VALLEY. WIDELY SCATTERED SHOWERS AND A FEW THUNDERSTORMS
NOW OVER SE TX AND ALONG THE UPPER TX COAST SHOULD CONTINUE TO
MOVE INLAND. THERE SEEMS TO BE A TREND IN THE SHOWER AND
THUNDERSTORM ACTIVITY DECREASING IN COVERAGE. THIS LOOKS TO BE
SUPPORTED BY LATEST HRRR MODEL RUNS WHICH ALSO SHOW MORE ACTIVITY
DEVELOPING DURING THE EARLY AFTERNOON. THINK IF THIS LULL IN
ACTIVITY DOES OCCUR AND CLOUD COVER LESSENS...MAY GET MORE HEATING
TO INITIATE ANOTHER ROUND OF STORMS THIS AFTERNOON. AS SUCH THINK
HOLDING ONTO 50/60 POPS THIS AFTERNOON LOOKS ON TRACK. MAX TEMP
FORECAST WILL BE TRICKY AS MOST INLAND AREAS ARE STILL IN THE 70S
AND MAY BE HARD PRESSED TO REACH THE LOW/MID 80S. GETTING SOME LOW
80S ALONG THE COAST WHERE CLOUDS ARE LESS SO FOR NOW THINK MAX
TEMPS FORECAST IS OKAY BUT LARGELY DEPENDS ON CLOUD COVER. IT
CERTAINLY WILL NOT GET ANY WARMER. UPDATED FORECAST HAS BEEN SENT.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 72 90 72 90 72 / 40 40 30 40 20
HOUSTON (IAH) 74 90 74 90 74 / 40 50 30 40 20
GALVESTON (GLS) 79 88 79 88 79 / 40 50 30 40 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...39
AVIATION/MARINE...38
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 PM CDT MON JUL 15 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 249 PM CDT MON JUL 15 2013
CURRENTLY AS OF 19Z...
WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS SHOWED TROUGHING OVER
SOUTHWEST CANADA...AN UPPER LOW OVER THE TEXAS PANHANDLE
RETROGRADING WESTWARD...AND A NEAR 600 DAM HIGH NEAR TOLEDO OHIO
ALSO RETROGRADING WESTWARD. STANDARD DEVIATIONS AGAIN WITH THIS HIGH
ARE RUNNING 2.5 ABOVE NORMAL. BETWEEN THE UPPER LOW AND SUBTROPICAL
HIGH...DEEP LAYER SOUTH TO SOUTHEAST WINDS ARE ADVECTING HIGHER
PRECIPITABLE WATER VALUES TOWARDS THE FORECAST AREA. 12Z DVN AND ILX
REPORTED VALUES OF 1.89 AND 2.04 INCHES RESPECTIVELY. HIGHER SURFACE
DEWPOINTS IN THE LOW 70S HAVE ACCOMPANIED THIS DEEP MOISTURE. WITH
TEMPERATURES THAT HAVE CLIMBED INTO THE UPPER 80S/LOW 90S...
RESULTING IN MLCAPE VALUES OF 500-1000 J/KG...ISOLATED SHOWERS HAVE
FORMED. NO LIGHTNING YET...WHICH MAY BE A RESULT OF THE SHALLOW
NATURE OF THE SHOWERS AND DEEP WARM CLOUD DEPTHS PREVENTING ICE
PRODUCTION. DESPITE THE HIGH 500MB HEIGHTS OVER THE FORECAST
AREA...ON THE ORDER OF 594-597 DAM...850MB TEMPS ARE ONLY 16-17C.
THE REASON THESE ARE COOL COMPARED TO THE 500MB HEIGHT IS A RESULT
OF THE SUBTROPICAL HIGH BEING OF ATLANTIC OCEAN ORIGIN. HAD IT COME
OUT OF THE WESTERN U.S....THE 850MB TEMPS WOULD BE A LOT HIGHER.
SYNOPTIC OVERVIEW...
MODELS CONTINUE TO SHOW THE STRONG SUBTROPICAL HIGH DRIFTING
WESTWARD THROUGH TUESDAY...REACHING NEAR GARY INDIANA BY 00Z
WEDNESDAY. THUS...500MB HEIGHTS WILL CONTINUE TO RISE OVER THE
FORECAST AREA...IMPLYING INCREASING MID-LEVEL SUBSIDENCE.
FOR TONIGHT...
ANY AFTERNOON CONVECTION THAT IS SPREADING NORTHWARD...ACCOMPANYING
THE HIGHER PRECIPITABLE WATER...WILL DIMINISH BY 03Z THIS EVENING
WITH LOSS OF HEATING SINCE IT IS HIGHLY DIURNALLY DRIVEN. THE REST
OF THE NIGHT LOOKS DRY WITH ANY FORCING FOR NOCTURNAL CONVECTION
WELL NORTH OF THE FORECAST AREA.
ON TUESDAY...
THE BATTLE CONTINUES OF WHETHER OR NOT TO NEED A MENTION OF SHOWERS
AND THUNDERSTORMS IN THE AFTERNOON. MODELS WERE A LITTLE HYPERACTIVE
WITH DIURNAL CONVECTION TODAY...ESPECIALLY THE 15.12Z NAM SHOWING
PRECIP ACROSS ALL OF ILLINOIS BY 15Z AND THERE WAS NONE IN REALITY.
ALL MODELS ARE IN AGREEMENT OF MUCH LESS QPF...AND THE 15.12Z NAM
CONTINUES TO SHOW A DRY FORECAST FOR THE FORECAST AREA. THERE ARE
OTHER NEGATIVES TOO FOR CONVECTION...BEING CLOSER TO THE SUBTROPICAL
HIGH...AND 0.25-0.5 INCH DRYING OF PRECIPITABLE WATER VALUES
ORIGINATING FROM EASTERN KY/TN THIS MORNING. SEEING THE DRY FORECAST
FROM THE NAM...THE 15.12Z CANADIAN WHICH DID A GOOD JOB WITH PRECIP
TODAY AND IS DRY FOR TUESDAY...ALONG WITH OTHER MODELS SHOWING VERY
LITTLE IF ANY QPF...WENT BACK TO A DRY FORECAST. 850MB TEMPS ARE 2C
HIGHER TOMORROW...BETWEEN 18-19C...SO WE SHOULD SEE ABOUT A SIMILAR
INCREASE IN HIGH TEMPERATURES INTO UPPER 80S/LOW 90S. DEWPOINTS UP
IN THE UPPER 60S/LOW 70S AND THE FORECAST HIGH TEMPERATURES WILL
LIKELY LEAD TO PLENTY OF CUMULUS...BUT MORE IMPORTANTLY MAKE IT FEEL
MUGGY. HEAT INDICES ARE STILL FORECAST TO TOP OUT IN THE 95-100
RANGE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 249 PM CDT MON JUL 15 2013
SYNOPTIC OVERVIEW...
MODELS REMAIN CONSISTENT IN THE STRONG SUBTROPICAL HIGH RETROGRADING
ACTUALLY SOUTHWESTWARD THROUGH THE REST OF THE WEEK. THIS IS IN
RESPONSE TO FIRST THE TROUGH IN SOUTHWEST CANADA MARCHING
EAST-NORTHEAST AND FLATTENING THE RIDGE...AND FINALLY AN UPPER LOW
CURRENTLY OFF THE COAST OF SAN FRANSISCO DROPPING SOUTHEAST THROUGH
THE FORECAST AREA AS A SHORTWAVE TROUGH. BY SATURDAY WE SHOULD BE
LOOKING AT TROUGHING OVER THE WESTERN GREAT LAKES VERSUS THE CURRENT
RIDGING. HEADING INTO SUNDAY AND MONDAY...INDICATIONS ARE THAT A
MORE POTENT SHORTWAVE TROUGH WILL BE APPROACHING THE AREA IN THE
NORTHWEST FLOW.
HAZARDS...
HEAT INDICES REMAIN THE BIG CONCERN. TUESDAY THROUGH THURSDAY LOOK
SOLID TO HAVE AFTERNOON HEAT INDICES BETWEEN 95-100...ESPECIALLY IN
THE VALLEYS. HEAT ADVISORY CRITERIA REQUIRES 100 OR GREATER FOR 1
DAY OR GREATER THAN 95 FOR 4 OR MORE DAYS. THE MORE LIKELY OF THE
TWO OPTIONS TO HIT WOULD BE DURATION. HEAT INDICES ONLY TOPPED OUT
IN THE UPPER 80S TO MID 90S TODAY...SO THAT MEANS FRIDAY WOULD NEED
95 OR GREATER. WITH CONCERN OF THE FRONT AND CONVECTION COMING
THROUGH FRIDAY...HAVE REFRAINED AT THIS TIME FROM ISSUING A HEAT
ADVISORY. HOWEVER...WE WILL ISSUE A SPECIAL WEATHER STATEMENT TO
DISCUSS THE HEAT. NOTE THAT THIS TIME PERIOD OF 15TH THROUGH 18TH
OF JULY IS COMMONLY THE TIME TO GET HEAT.
THERE IS A POSSIBILITY OF SEVERE WEATHER TOO IN THE THURSDAY THROUGH
FRIDAY TIME PERIOD. THURSDAY/THURSDAY NIGHT WOULD BE MORE TO THE
NORTH...PERHAPS JUST TAYLOR/CLARK COUNTIES AS ALSO SHOWN IN THE SPC
DAY 4-8 OUTLOOK. FRIDAY IT ALL DEPENDS ON THE FRONTAL TIMING.
ADDITIONALLY...THE BEST 0-6KM SHEAR IS BEHIND THE FRONT...WITH ONLY
30-35 KT ON THE FRONT. SO IT WOULD SEEM THAT OVERALL ANY SEVERE
WEATHER WOULD BE ISOLATED WITH DAMAGING WINDS AND HEAVY RAIN THE
MAIN HAZARDS.
DAILY DETAILS...
TUESDAY NIGHT AND WEDNESDAY...
A COLD FRONT ACCOMPANYING THE SOUTHWEST CANADA TROUGH IS PROGGED TO
DROP INTO NORTHERN MN BY 12Z WED AND THEN LAY UP BETWEEN ST CLOUD MN
AND UPPER MI LATE WEDNESDAY. ENVISIONING CONVECTION ON THIS
BOUNDARY...DUE TO PLENTIFUL MOISTURE AND INSTABILITY AROUND IT...
ALONG WITH LAKE BREEZE ENHANCED CONVERGENCE. GIVEN ITS LOCATION...
ANTICIPATING ANY CONVECTION TO STAY UP TO THE NORTH THROUGH
WEDNESDAY. WILL NEED TO MONITOR TAYLOR COUNTY FOR A NEED FOR SOME
CHANCES OF PRECIPITATION IN LATER FORECASTS SHOULD THE BOUNDARY DROP
FARTHER SOUTH. OTHERWISE...PRECIPITABLE WATER VALUES ARE PROGGED TO
HOLD STEADY OR EVEN FALL A LITTLE MORE COMPARED TO TUESDAY...SO NOT
ANTICIPATING ANY DIURNAL CONVECTION. WITH CONTINUED AIRMASS
MODIFICATION OF THE SUBTROPICAL HIGH...850MB TEMPS CLIMB ABOUT
ANOTHER 1C...WHICH WITH PLENTY OF SUN SHOULD YIELD ANOTHER DAY OF
HIGHS IN THE UPPER 80S/LOW 90S.
WEDNESDAY NIGHT THROUGH THURSDAY NIGHT...
THIS PERIOD APPEARS A BIT MORE MUDDLED / LESS CONFIDENCE / THAN
BEFORE. WITH A ZONAL UPPER FLOW PATTERN THROUGH THURSDAY...THE COLD
FRONT SITUATED UP TO OUR NORTH APPEARS LIKELY TO STAY IN PLACE. IN
FACT...ON THURSDAY NIGHT WHEN THE SHORTWAVE TROUGH DROPS INTO THE
DAKOTAS...THE FRONT COULD EVEN GET PROPELLED NORTHWARD. 15.12Z
ECMWF/GFS/NAM/UKMET/CANADIAN ALL DEPICT THE NOSE/GRADIENT OF THE
850MB MOISTURE TRANSPORT STAYING FOCUSED FROM NORTHERN MN INTO
NORTHERN WI/UPPER MI AND LOWER MI FROM WEDNESDAY NIGHT THROUGH
THURSDAY NIGHT. FIGURE CONVECTION WOULD EITHER BE TIED TO THE FRONT
OR NOSE OF THE MOISTURE TRANSPORT...WHICH BOTH SUGGEST NORTH OF THE
FORECAST AREA. CORFIDI VECTORS ARE FAIRLY LIGHT TOO IN TERMS OF
SPEEDS WITH DIRECTIONS MAINLY WEST OR WEST-NORTHWEST...SO IF AN MCS
FORMS IT COULD END UP STAYING NORTH OF THE AREA AS WELL. GIVEN ALL
OF THIS...HAVE DECIDED TO SHIFT ALL OF THE PRECIPITATION CHANCES
NORTHWARD...WHICH MEANS A REDUCTION ACROSS THE BOARD. WOULD NOT BE
SURPRISED IF ALL STORMS DURING THIS PERIOD STAY NORTH OF HIGHWAY 29.
TEMPERATURES THURSDAY LOOK SIMILAR TO TUESDAY AND WEDNESDAY WITH
850MB TEMPS OF 18-20C.
FRIDAY THROUGH MONDAY...
GOOD AGREEMENT REMAINS ABOUT THE COLD FRONT COMING THROUGH THE AREA
ON FRIDAY...AHEAD OF THE SHORTWAVE TROUGH. HAVE SOME CONCERN THAT
THIS FRONT COULD COME THROUGH DRY SEEING THE 15.00Z ECMWF. THREE
NEGATIVES WITH THIS FRONT FOR CONVECTION IS THE POSITIVELY TITLED
NATURE OF THE SHORTWAVE...WEAK CONVERGENCE AND THAT THE TIMING MAY
BE MESSED UP. FOR NOW LEFT A MODEL CONSENSUS 20-40 PERCENT CHANCES
IN THE FORECAST INTO FRIDAY EVENING. HIGH PRESSURE IS STILL
INDICATED TO BUILD INTO THE AREA FOR THE WEEKEND. HOWEVER...BEING
UNDER UPPER TROUGHING YIELDS CONCERNS FOR SHORTWAVES COMING THROUGH
AT PEAK HEATING AND INITIATING CONVECTION. THE 15.00Z ECMWF HINTED
AT THIS FOR SATURDAY...BUT THE 15.12Z RUN IS NOW DRY. WITH A DRY GFS
FORECAST...HAVE KEPT SATURDAY INTO SATURDAY NIGHT DRY. MUCH OF
SUNDAY MAY BE DRY TOO...THOUGH THERE ARE INDICATIONS FROM THE 15.12Z
ECMWF OF A SHORTWAVE MOVING INTO MN BRINGING CONVECTION TO LOCATIONS
MAINLY WEST OF THE MS RIVER. THUS...HAD TO KEEP SOME LOW CHANCES
THERE. ADDITIONAL CHANCES IN THE 20-40 RANGE ARE FORECAST INTO
MONDAY ASSOCIATED WITH THE MORE POTENT SHORTWAVE. TIMING IS STILL
YET TO BE DETERMINED ON THIS SHORTWAVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1211 PM CDT MON JUL 15 2013
NOT MUCH OF A FOCUS FOR CONVECTION TO DEVELOP THIS AFTERNOON...BUT
STILL POSSIBLE. THE 15.15Z RAP CONTINUES TO SUGGEST THE
POSSIBILITY OF A WEAK MID LEVEL SHORT WAVE TROUGH TO MOVE ACROSS
THE AREA ON THE WEST SIDE OF THE ATLANTIC RIDGE ALONG WITH SOME
WEAKENING LOW TO MID LEVEL MOISTURE TRANSPORT ASSOCIATED WITH THE
WAVE. A FEW SHOWERS HAVE ALREADY POPPED UP NORTH OF THE TAF SITES
WHERE THERE IS SOME WEAK SURFACE CONVERGENCE. HIGHER CONFIDENCE
THAT ANY SHOWERS THAT DEVELOP THROUGH THE AFTERNOON WILL MISS THE
TAF SITES BUT SINCE VCSH ALREADY INCLUDED IN THE FORECAST WILL
LEAVE IT IN. WILL INCLUDE SOME MVFR VISIBILITY FOR FOG OVERNIGHT
AS THE 15.12Z NAM BUFKIT SOUNDING SHOWS SATURATION OCCURRING AT
THE SURFACE FOR BOTH SITES. HOWEVER...THE 15.15Z RAP DOES NOT SHOW
THIS AND BOTH MODELS ALSO HAVE WINDS OF 10+ KNOTS NOT FAR ABOVE
THE SURFACE. BETTER CHANCE FOR THE VALLEY TO DECOUPLE AT KLSE SO
HAVE GONE WITH A CATEGORICAL VISIBILITY RESTRICTION THERE WHILE
JUST INCLUDING IT IN A TEMPO GROUP AT KLSE. SHOULD SEE SOME LATE
MORNING CUMULUS CLOUDS DEVELOP AGAIN TUESDAY BUT WILL LET LATER
FORECASTS DETAIL THIS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...04