Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/30/12
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
927 PM MDT SUN JUL 29 2012
.UPDATE...
UPDATED TO REMOVE POPS FOR THE PLAINS FOR THE REST OF TONIGHT. AN
OUTFLOW BOUNDARY HAS SHIFTED SOUTH ACROSS THE PLAINS WHICH HAS
HELPED STABILIZE THE PLAINS. ISOLATED SHOWER AND THUNDERSTORM
ACTIVITY WILL CONTINUE OVER THE MOUNTAIN REGIONS...ESPECIALLY THE
CONTINENTAL DIVIDE AREA. NO OTHER CHANGES AT THIS TIME. MOZLEY
&&
.PREV DISCUSSION... /ISSUED 355 PM MDT SUN JUL 29 2012/
SHORT TERM...
(TONIGHT AND MONDAY)
WATER VAPOR LOOPS TODAY CONTINUE TO SHOW DRY AIR PUNCHING IN UNDER
THE RIDGE ACROSS NM/SRN CO. LATEST AMSU SSM/I PRECIP WATER SAT PICS
ALSO SHOWING VALUES DROPPING OFF TO THE SOUTH...BUT STILL AN AXIS OF
HIGH PRECIP WATERS EXTENDING ACROSS NW CO. A COUPLE SHORTWAVES
EVIDENT IN WV PICS ACROSS UT/NW CO. MAIN FORCING FROM THESE MAY END
UP STAYING JUST TO THE NORTH OF THE FORECAST...BUT STILL ENOUGH
MOISTURE PRESENT WITHIN MONSOON PLUME ALOFT FOR SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS. GREATEST
COVERAGE WILL BE ACROSS CHAFFEE AND LAKE COUNTIES...AND POSSIBLY
TELLER...THOUGH EACH SUCCESSIVE HRRR RUN SEEMS TO SHIFT
AXIS OF HIGHER QPF TO THE NORTH ACROSS PARK COUNTY. WITH PRECIP
WATERS STILL AVERAGING AROUND OR SLIGHTLY BETTER THAN 100 PERCENT OF
NORMAL ACROSS THE SOUTHEAST MTS/ADJACENT PLAINS...LOCALLY HEAVY RAIN
WILL STILL BE A THREAT...PARTICULARLY FOR THE WALDO CANYON BURN SCAR
WHERE SOILS ARE SUSCEPTIBLE TO FLASH FLOODING WITH EVEN MINOR
AMOUNTS OF RAINFALL...ESPECIALLY WITH THE LIGHT RAIN THAT FELL
ACROSS THE REGION YESTERDAY. THE LOOSE SOILS OF THE CHALK CLIFFS IN
CHAFFEE COUNTY WOULD BE PRONE TO FLASH FLOODING TODAY AS WELL.
CONVECTION WHICH FIRES OFF TO THE NORTH AND MOVES ACROSS THE NE
PLAINS WILL SEND AN INITIAL CONVECTIVE OUTFLOW BOUNDARY THROUGH THE
NRN I-25 CORRIDOR...WITH A WIND SHIFT FROM THE WEST TO NORTHWEST
DURING THE EVENING PRIOR TO THE MAIN FRONT DROPPING SOUTHWARD
THROUGH THE PLAINS AFTER 03Z. LATEST NAM12 ADVECTS SOME LOWER 50S
DEW POINTS BEHIND THE FRONT INTO SE CO BY MON MORNING...THEN SHIFTS
WINDS WEAKLY FROM THE EAST AND MIXES OUT LOW LEVEL MOISTURE AGAIN BY
AFTERNOON...WITH DEW POINTS FALLING OFF INTO THE LOWER TO MID 40S BY
21Z. DRY AIR ALOFT WILL STILL BE LINGERING OVER SOUTHERN
AREAS...WITH MONSOON PLUME WITH ITS WEAK EMBEDDED IMPULSES EXTENDING
ACROSS UT THROUGH NRN AND CENTRAL CO. THUS GREATEST THREAT FOR
WIDESPREAD THUNDERSTORMS/HEAVY RAIN WILL BE ACROSS NORTHERN PORTIONS
OF THE FORECAST AREA. QUITE A BIT OF DISCREPANCIES IN THE MODEL
QPFS BETWEEN THE DRIER NAM AND THE WET GFS. GFS KEEPS DEW POINTS
ACROSS THE SE PLAINS IN THE 50S THROUGH THE AFTERNOON WITH STRONGER
EASTERLY UPSLOPE FLOW...RESULTING IN GREATER QPF FOR THE SE MTS.
ECMWF SIDES WITH THE DRIER NAM12...AND SREF IS SOMEWHERE IN
BETWEEN...THOUGH ITS QPF IS GENERALLY UNDER .25 ON AN AREAL AVERAGE
BASIS. LCLS STILL LOOK A LITTLE TOO HIGH TO JUSTIFY A FLASH FLOOD
WATCH AT THIS POINT...SO PLAN TO HOLD OFF. LATER SHIFTS CAN GET A
LOOK AT THE HIGH RES MODEL RUNS TONIGHT AND DECIDE IF ONE IS
JUSTIFIED. A LOT WILL DEPEND ON HOW FAR NORTH THE DRY AIR ALOFT
PROGRESSES OVERNIGHT. HOWEVER...THERE COULD BE A HEIGHTENED CONCERN
FOR FLASH FLOODING ON THE WALDO BURN SCAR TOMORROW VS THE PAST FEW
DAYS...AS SFC DEW POINTS SHOULD REMAIN A LITTLE HIGHER.
OTHERWISE...TEMPERATURES SHOULD BE SLIGHTLY COOLER ACROSS THE PLAINS
BEHIND THE FRONT...THOUGH STILL APPROACHING 100 NEAR THE CO/KS
BORDER. MTN AREAS WILL SEE HIGHS SIMILAR TO A COUPLE DEGREES
WARMER. -KT
LONG TERM...
(MONDAY NIGHT THROUGH SUNDAY)
LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES AND
POPS. 12Z/28TH GFS40 INDICATES THAT UPPER HIGH CENTERED OVER
NORTHEASTERN NEW MEXICO AT 00Z TUESDAY HOVERS OVER NEW MEXICO INTO
NEXT WEEKEND WHILE THE 12Z/28TH ECMWF SUGGESTS THAT HEALTHY UPPER
HIGH LOCATED OVER NORTHEASTERN NEW MEXICO AT 00Z TUESDAY SHIFTS
INTO NORTH TEXAS BY 06Z SATURDAY. IN ADDITION...THE 06Z/28TH DGEX
SUGGESTS THAT THE UPPER HIGH WILL BE OVER MISSOURI BY NEXT SUNDAY.
AT THE SURFACE...NORTHERLY SURGES IMPACTING PRIMARILY EASTERN
PORTIONS OF THE FORECAST DISTRICT ARE ANTICIPATED THURSDAY
MORNING...WITH A STRONGER NORTHERLY SURGE EXPECTED SATURDAY
MORNING.
THE COMBINATION OF RELATIVELY PERSISTENT DEEPER ATMOSPHERIC
MOISTURE/HIGHER PRECIPITABLE WATER VALUES IN COMBINATION WITH
THE DAILY HEATING CYCLE...THE AFORE-MENTIONED NORTHERLY SURGES
AND INCREASING UPPER ENERGY(ESPECIALLY AFTER TUESDAY) WILL ALLOW
ISOLATED TO SCATTERED PRIMARILY AFTERNOON AND EVENING
THUNDERSTORMS(SOME CONTAINING LOCALLY HEAVY RAIN AND HAIL) TO BE
NOTED OVER THE MAJORITY OF THE FORECAST DISTRICT INTO NEXT
WEEKEND.
BLEND OF LATEST COMPUTER SIMULATIONS SUGGEST THAT INCREASING
PROBABILITIES OF THUNDERSTORMS WILL BE POSSIBLE OVER PORTIONS OF
THE I-25 CORRIDOR/EASTERN COLORADO PLAINS AS THE WEEK PROGRESSES
AND INTO NEXT WEEKEND.
AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE
LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND FLASH
FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS THE
WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
MAXIMUM AND MINIMUM TEMPERATURES FROM TUESDAY NIGHT INTO NEXT
SUNDAY ARE STILL EXPECTED TO RUN A CATEGORY OR TWO ABOVE LATE
JULY/EARLY AUGUST CLIMATOLOGICAL AVERAGES.
AVIATION...
VCTS WILL BE POSSIBLE AT TAF SITES THROUGH 02-03Z. GUSTY ERRATIC
WINDS UP TO 35 KTS WILL BE POSSIBLE NEAR -TSRA POSSIBLY AFFECTING
THE KCOS AND KPUB SITES. VFR CIGS/VIS IN LIGHT RAIN WILL ALSO BE
POSSIBLE SHOULD STORMS BE LUCKY ENOUGH TO HIT THE TERMINAL. AT THIS
POINT THREAT LOOKS FAIRLY LOW...AND WILL MAINTAIN VCTS. CONVECTION
OVER THE MOUNTAINS SHOULD SHIFT WINDS FROM THE NORTH TO NORTHWEST AT
BOTH KCOS AND KPUB AROUND 00Z WITH GUSTS IN THE 15-25 KT RANGE.
FRONT WILL DROP THROUGH THE PLAINS AFTER 03Z...WHICH SHOULD KEEP
WINDS FROM THE NORTH AT AROUND 10-15 KTS FOR BOTH KCOS AND KPUB
THROUGH 09Z. MEANWHILE...THUNDERSTORM COVERAGE SHOULD DECREASE
AFTER SUNSET...THOUGH ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE
OVER AND NEAR THE MOUNTAINS THROUGH AT LEAST 06Z. ON MONDAY...WINDS
WILL SWING AROUND FROM THE EAST TO SOUTHEAST ACROSS THE PLAINS
DURING THE AFTERNOON WITH A SLIGHTLY BETTER CHANCE FOR -TSRA AT THE
KCOS TAF SITE DURING THE AFTERNOON. WINDS WILL REMAIN LIGHT AT KALS.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
88/40
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1117 AM MDT SAT JUL 28 2012
.UPDATE...
LATEST OBS/RADAR SHOWING BOUNDARY MAKING A STRONGER PUSH SOUTHWARD
THAN PREVIOUS MODELS HAD INDICATED. NORTH WINDS HAVE ALREADY
SPREAD INTO NRN PUEBLO COUNTY...AND LATEST HRRR PLACES THIS
BOUNDARY ALONG AN AXIS FROM WALSENBURG TO KLHX...TO ARLINGTON BY 20Z.
TO THE NORTH OF THIS BOUNDARY...DEW POINTS MIX OUT INTO THE LOWER
40S...POSSIBLY EVEN SOME UPPER 30S...WHILE 40S PERSIST TO THE
SOUTH AND EAST OF THIS BOUNDARY. HRRR BREAKS OUT SOME HIGH BASED
CONVECTION ALONG THIS AXIS IN THE AFTERNOON. WHILE COVERAGE LOOKS
A LITTLE OVERDONE...HAVE EXPANDED SOME 15-20 PERCENT POPS SOUTH
AND EASTWARD. LATEST HRRR AND RUC KEEP ANY PRECIPITATION OFF THE
WALDO CANYON BURN SCAR UNTIL AFTER 21Z...AND WITH BOUNDARY
POSITIONED FARTHER TO THE SOUTH...THIS LOOKS PLAUSIBLE. WE WILL
STILL BE UNDER THE MONSOON PLUME THOUGH...AND SUBJECT TO HIT OR
MISS STORMS FIRED OFF BY CONVECTIVE HEATING. WITH PRECIP WATERS IN
12Z SOUNDINGS RUNNING AROUND 115 PERCENT OF NORMAL ACROSS THE
EAST...AND 150 PERCENT OF NORMAL ACROSS WESTERN CO...LOCALLY HEAVY
RAINFALL WILL BE THE PRIMARY THREAT WITH ANY STORMS. WITH THE HIGH
LCLS...DON`T SEE ENOUGH OF A THREAT TO WARRANT A FLASH FLOOD WATCH
FOR THE WALDO BURN SCAR...BUT CLOSE MONITORING OF STORMS WILL BE
NEEDED THIS AFTERNOON...AS A DIRECT HIT FROM A STRONGER STORM
WOULD CERTAINLY BE SUFFICIENT TO CAUSE FLASH FLOODING. -KT
&&
.AVIATION...
VFR CONDITIONS EXPECTED AT TAF SITES WITH TSRA DEVELOPING ACROSS
THE MOUNTAINS AROUND 18Z. VCTS WILL BE POSSIBLE AT ALL THREE TAF
SITES AFTER BEGINNING AROUND 20-21Z...THOUGH KALS WILL HAVE THE
BEST CHANCE AND WILL INTRODUCE A TEMPO GROUP FROM 20Z-23Z. GUSTY
ERRATIC WINDS FROM THUNDERSTORM OUTFLOWS WILL BE POSSIBLE AT ALL 3
TAF SITES THIS AFTERNOON WITH GUSTS UP TO 35-40 KTS POSSIBLE.
MEANWHILE...MTN AREAS WILL SEE SCATTERED TO NUMEROUS THUNDERSTORMS
WITH MTN OBSCURATIONS AT TIMES DUE TO TSRA...ESPECIALLY ALONG THE
CONTINENTAL DIVIDE WHERE TSRA WILL BE MOST NUMEROUS. THUNDERSTORMS
WILL DIMINISH AFTER SUNSET WITH VFR CONVECTIVE DEBRIS CLOUDINESS
GRADUALLY DECREASING THROUGH THE NIGHT. -KT
&&
.PREV DISCUSSION... /ISSUED 415 AM MDT SAT JUL 28 2012/
SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...THE UPPER RIDGE AXIS REMAINED OVER WESTERN KS EARLY THIS
MORNING WITH THE VERY EVIDENT MONSOON PLUME BEING DRAWN UP ACROSS
THE 4 CORNERS AND INTO CO...AS PER RAP H5 ANALYSIS AND IR SATELLITE
IMAGERY. SFC OBS INDICATED THAT TEMPS HAD DROPPED INTO THE UPPER 50S
TO MID 60S FOR MOST PLAINS LOCATIONS AND DOWN TO AROUND 50F FOR THE
HIGH VALLEYS AS OF 330 AM. DEWPOINT TEMPS WERE FAIRLY UNIFORM FOR
THE CWA...IN THE MID 40S TO LOWER 50S.
TODAY AND TONIGHT...THE WEATHER TREND FOR TODAY LOOKS LIKE IT WILL
BE VERY SIMILAR TO FRIDAY...MINUS THE SPARK PROVIDED BY THE UPPER
DISTURBANCE THAT ROLLED ACROSS THE ROCKIES. PRECIPITABLE WATER
REMAINS AT OR SLIGHTLY ABOVE NORM...BUT UPPER AIR SOUNDINGS POINT
TO SOMEWHAT DRY LOW LEVELS. THE RIDGE AXIS REMAINING NEAR THE
CO/KS BORDER WILL IMPART A GRADUAL N-NE MOVEMENT FOR ANY STORMS
THAT DO DEVELOP OVER THE HIGHER TERRAIN THIS AFTN. MODELS ARE
HINTING AT A SFC BOUNDARY LURKING ALONG THE PALMER DVD THIS
AFTN...AND WHERE THIS BOUNDARY STALLS WILL BE A FOCUS AREA FOR
CONVECTION. DECIDED TO HOLD ONTO THE ONGOING FORECAST THAT KEEPS
THIS BOUNDARY PRIMARILY NORTH OF THE PALMER DVD...WITH CONVECTION
FIRING OVER MONUMENT HILL THIS AFTN BUT NOT ALONG KIOWA COUNTY.
EXPECT ANOTHER HOT DAY TODAY WITH MAX TEMPS RIGHT AROUND 100 F FOR
THE PLAINS...AND IN THE 80S FOR THE HIGH VALLEYS.
THE MAIN FORECAST CONCERN CONTINUES TO BE THE FLASH FLOOD POTENTIAL
FOR THE WALDO CANYON BURN SCAR THIS AFTN AND EVE. INDIVIDUAL STORMS
HAVE SHOWN SOME SPOTTY HIGHER RAINFALL RATES OVER THE PAST WEEK AND
LUCKILY HAVE SIDE-STEPPED THE BURN SCAR FOR THE MOST PART...BUT WITH
LITTLE CHANGE IN THE OVERALL PATTERN LOCALLY HEAVY RAINFALL REMAINS
A THREAT. 27
LONG TERM...
(SUNDAY THROUGH SATURDAY)
CONCERNS ARE COVERAGE OF SLOW MOVING THUNDERSTORMS THROUGH THE
WEEK...ESPECIALLY MONDAY.
SUNDAY THROUGH MONDAY...UPPER RIDGE CENTERED OVER WESTERN US WILL
PROVIDE WEAK WEST TO SOUTHWEST FLOW ALOFT. A SHORTWAVE MOVING
SOUTHEAST THROUGH THE GREAT PLAINS WILL BRING A COUPLE OF
BOUNDARIES INTO EASTERN COLORADO. THE STRONGER PUSH OF
COOLER...AND SLIGHTLY MOISTER LOW LEVEL AIR WILL LIKELY OCCUR
SUNDAY NIGHT WITH EASTERLY UPSLOPE FLOW DEVELOPING ACROSS THE
PLAINS THROUGH THE DAY ON MONDAY. BUT...MONSOONAL MOISTURE
FORECAST TO MOVE MAINLY WEST AND NORTH OF THE CWA. ISOLATED TO
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL
OCCUR...WITH BEST COVERAGE REMAINING OVER AND ADJACENT TO THE
MOUNTAINS. WEAK FLOW ALOFT WILL BRING THE THREAT FOR LOCALLY HEAVY
RAINFALL AND THE POSSIBILITY OF FLASH FLOODING...ESPECIALLY IF
CELLS DEVELOP OVER THE BURN SCARS...INCLUDING THE WALDO CANYON
BURN SCAR. MID LEVEL TEMPERATURES WILL BE A BIT LOWER ON MONDAY
ACROSS THE PLAINS...BUT STILL...TEMPERATURES WILL BE ABOVE
SEASONAL AVERAGES BOTH DAYS.
TUESDAY-FRIDAY...UPPER LEVEL RIDGE FORECAST TO PERSIST JUST SOUTH
OF THE AREA...WITH RESULTANT WEAK WESTERLY FLOW ALOFT. MODELS
ALSO NOT TOO HEAVY HANDED WITH THE MONSOON MOISTURE. THERE WILL BE
ENOUGH MOISTURE FOR DAILY ISOLATED TO SCATTERED COVERAGE OF
PRECIPITATION WITH TEMPERATURES RISING A BIT FROM EARLY WEEKS
LEVELS. -TLM-
AVIATION...
VFR CONDITIONS ARE EXPECTED FOR THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. HOWEVER...ISOLATED
CONVECTION WILL AFFECT KCOS AND KALS AFTER 18Z AND LASTING THROUGH
03Z...WITH THE MAIN THREAT BEING GUSTY WINDS OF 35-40 KTS. STORMS
WILL BE MORE SCATTERED OVER THE HIGHER TERRAIN...LINGERING THE
LONGEST OVER THE CONTDVD. THE STEERING FLOW IS FORECAST TO REMAIN
GENERALLY LIGHT AND FROM THE S-SW...SO ANY STORMS THAT FORM OVER THE
MTS WILL SLOWLY MOVE TO THE N-NE. 27
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/77
AREA FORECAST DISCUSSION
NWS DENVER CO
1029 AM MDT SAT JUL 28 2012
.UPDATE...WEAK NORTHERLY PUSH MOVED ACROSS THE PLAINS THIS
MORNING. THIS SLIGHTLY COOLER BOUNDARY LAYER...COMBINED WITH SOME
MID LEVEL CLOUDINESS...HAS DELAYED THE PLAINS HEATING A BIT AND
WILL LIKELY ALLOW THE CAP TO HOLD IN PLACE TIL LATE AFTERNOON. AS
A RESULT...HAVE DELAYED THE POPS A BIT ON THE PLAINS WHILE
LOWERING THEM SLIGHTLY OVER THE NORTHEASTERN PORTIONS OF THE
PLAINS WHERE CAP IS NORMALLY STRONGEST IN THESE SITUATIONS. LATEST
HRRR AND RAP ALSO SUGGEST A LATER ARRIVAL OF CONVECTION ON THE
PLAINS...AND EVEN HINT AT THE CAP REMAINING STRONG ENOUGH TO
PREVENT CONVECTION THIS AFTERNOON. WILL CONTINUE TO MONITOR
PROGRESSION.
MEANWHILE...THE MOUNTAINS AND FOOTHILLS SHOULD SEE ANOTHER ACTIVE
DAY WITH PLENTY OF PW AND VALUES ABOUT 0.10 TO 0.20 INCH HIGHER
THAN YESTERDAY. LOOKS LIKE THE BEST MOISTURE PLUME IS AIMING
TOWARD SUMMIT/PARK COUNTIES AND THE SOUTHERN FOOTHILLS. THE WEAK
Q-G SUBSIDENCE SHOULD ALSO ABATE LATER THIS AFTERNOON PER THE
LATEST Q-G ANALYSIS/TRENDS ALLOWING FOR RATHER HIGH CONVECTIVE
COVERAGE.
&&
.AVIATION...PER DISCUSSION ABOVE...CAP WILL LIKELY TAKE LONGER TO
ERODE ACROSS THE PLAINS THIS AFTERNOON/EVENING WITH WEAK BOUNDARY
LAYER COOLING AND SOME MID LEVEL CLOUDINESS. WILL PUSH BACK
THUNDER CHANCES A COUPLE HOURS AND CENTER IT CLOSER TO 00Z. SOME
CHANCE THAT CONVECTION MAY NOT AFFECT FRONT RANGE AIRPORTS IF CAP
IS A LITTLE STRONGER. WILL MONITOR LATEST ACARS SOUNDINGS FOR
THUNDER UPDATES THIS AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 345 AM MDT SAT JUL 28 2012/
SHORT TERM...BROAD HIGH PRESSURE ALOFT CENTERED OVER THE
PANHANDLES OF TEXAS AND OKLAHOMA WITH A HEALTHY WESTERLY FLOW
ALOFT OVER NORTHERN COLORADO. WATER VAPOR IMAGERY CONTINUES TO SHOW THE
MOISTURE PLUME OVER MUCH OF COLORADO STREAMING IN FROM ARIZONA AND
WESTERN NEW MEXICO. GIVEN SATELLITE TRENDS DON`T REALLY SEE MUCH
CHANGE IN THE OVERALL MOISTURE LEVELS THROUGH TONIGHT. CURRENT IPW
VALUES FROM GPS ARE JUST UNDER AN INCH OVER THE PLAINS. BOTH
NAM/GFS BUMP UP PW VALUES TO JUST OVER AN INCH BY AFTERNOON.
HOWEVER BOTH GFS/NAM SEEM TO KEEP MOST OF THE PRECIP OVER THE
MOUNTAINS...FOOTHILLS AND PALMER DIVIDE WITH VERY LITTLE PRECIP
OVER THE PLAINS. GIVEN THE WESTERLY FLOW DON`T SEE WHY THE STORMS
WON`T BE ABLE TO MAKE IT OVER ONTO THE PLAINS. MODEL DEWPOINTS SEE
A BIT LOW AS WE SHOULD BE ABLE TO HOLD DEWPOINTS IN THE MID 40S TO
AROUND 50. THIS WILL RESULT IN SFC BASED CAPES FROM 500-1000J/KG.
HAVE BUMPED UP POPS 10 PERCENT ACROSS THE BOARD OVER THE PLAINS
FOR THIS AFTERNOON AND EVENING.
LONG TERM...THE STRONG UPPER LEVEL SUBTROPICAL HIGH PRESSURE
RIDGE CENTERED OVER OKLAHOMA SUNDAY MORNING IS FORECAST TO SHIFT
SOUTHWARD OVER NORTHERN TEXAS DURING THE DAY. THIS ALLOWS THE
PLUME OF MOIST SUBTROPICAL AIR HOVERING OVER THE DESERT SOUTHWEST
TO STREAM NORTHEASTWARD OVER COLORADO THROUGH SUNDAY NIGHT.
MODELS SHOW 850-500MB PRECIPITABLE WATER AND MEAN LAYER SPECIFIC
HUMIDITY VALUES CLIMBING DURING THE DAY SUNDAY AS THE MAIN PUSH OF
MOISTURE PASSES OVER THE FORECAST AREA LATE IN THE DAY. NAM DOES
NOT INDICATE ALL THAT MUCH QUASI-GEOSTROPHIC ASCENT OR SFC-500MB
INSTABILITY AROUND ON SUNDAY. WHEREAS THE GFS SHOWS ABOUT THE SAME
AMOUNT OF Q-G LIFT BUT QUITE A BIT MORE LOW-LEVEL CAPE/INSTABILITY
DUE LARGELY TO MORE PRECIPITABLE WATER AROUND. ECMWF CAPE AND Q-G
ASCENT ABOUT THE SAME AS THAT ON THE GFS. MEANWHILE SOUTHWEST
FLOW ALOFT IS RELATIVELY WEAK ON ALL THREE MODELS ON SUNDAY. LIGHT
EASTERLY/UPSLOPE FLOW ALSO ACCOUNTING FOR THE INCREASE IN LOW-
LEVEL MOISTURE EAST OF THE MTNS. PW VALUES SOMEWHERE BETWEEN 0.80
AND 1.10 INCH ON THE PLAINS BY LATE AFTERNOON AND ABOUT 0.70 INCH
IN THE HIGH COUNTRY. WITH THIS MUCH WATER VAPOR HANGING AROUND...
COULD SEE SKIES CLOUDING OVER BEFORE SOLAR HEATING HAS TIME TO
GENERATE STORMS. THAT MAY EXPLAIN THE LOW POPS OFFERED BY THE
MODEL GUIDANCE. STILL FEEL THERE/S SUFFICIENT CAUSE TO STICK WITH
THE 20-30 PCT POPS ON THE PLAINS AND 30-50 PCT POPS IN THE HIGH
COUNTRY SUNDAY AFTERNOON AND EVENING. HOWEVER IT MAY REQUIRE
BOUNDARIES MOVING DOWN FROM STORMS SCATTERED OVER THE FOOTHILLS TO
INITIATE STORM DEVELOPMENT OVER THE ADJACENT PLAINS. THIS MAY NOT
HAPPEN UNTIL LATE..SAY 5 OR 6 PM DEPENDING ON THE AMOUNT OF CLOUD
COVERAGE. SLOW STORM MOTIONS AND THE POSSIBILITY OF TRAINING
STORMS COULD RESULT IN LOCALLY HEAVY RAINFALL...UPWARDS OF AN INCH
IN UNDER 30 MINUTES...MAINLY OVER AND NEAR THE FRONT RANGE. AS HAS
BEEN THE CASE THIS SUMMER...BURN SCARS MOST SUSCEPTIBLE TO FLASH
FLOODING SHOULD THIS SCENARIO PAN OUT.
COULD SEE STORMS LINGERING ON THE PLAINS WELL INTO THE OVERNIGHT
HOURS...MAINLY OUT NEAR THE EASTERN BORDER. LACK OF SHEAR OR MUCH
INSTABILITY SHOULD LIMIT SEVERE WX BUT BRIEF HEAVY RAIN STILL
POSSIBLE.
FOR MONDAY AND TUESDAY...THE SUBTROPICAL HIGH OVER NORTHERN TEXAS
ON SUNDAY MIGRATES WESTWARD OVER THE TEXAS/OKLAHOMA PANHANDLE
ON MONDAY WHERE IT LINGERS THROUGH TUESDAY. AS A CONSEQUENCE
STEERING WINDS ALOFT OVER NORTHEAST COLORADO BECOME MORE WESTERLY
IN DIRECTION. PULSES OF MONSOONAL MOISTURE CARRIED ALONG BY THIS
FLOW SHOULD KEEP THE CHANCE OF THE T-STORMS GOING IN THE HIGH
COUNTRY THROUGH TUESDAY EVENING. WHEREAS THIS SAME WESTERLY FLOW
WILL LIKELY REDUCE THE CHANCE OF STORMS ON THE PLAINS EVEN WITH
ALL OF THE MOISTURE AT MID-LEVELS. CAN/T RULE OUT A FEW STORMS
DRIFTING OFF THE FOOTHILLS AND OVER THE NEARBY PLAINS CAPABLE OF
BRIEF HEAVY RAIN IN THE AFTERNOON AND EVENING BOTH DAYS. STORMS
ARE NOT EXPECTED TO MOVE TOO FAR OUT OVER THE PLAINS WHERE THE
ATMOSPHERE LOOKS STRONGLY CAPPED.
FOR WEDNESDAY AND THURSDAY...WESTERLY FLOW ALOFT REMAINS IN PLACE
WITH THE UPPER LEVEL HIGH CONTINUING ITS SLOW WESTWARD TRACK ACROSS
NORTHERN NEW MEXICO. WEDNESDAY LOOKS DRIER...EVEN IN THE HIGH
COUNTRY...WITH SUBSIDENCE/WARMING ALOFT. BY THURSDAY...MODELS
INDICATE A RESURGENCE IN SUBTROPICAL MOISTURE ASSOCIATED WITH THE
PASSAGE OF A WEAK UPPER AIR DISTURBANCE. MEDIUM RANGE MODELS SHOW
THIS WAVE PASSING OVER THE FORECAST AREA AROUND MAX HEATING. SO
THE CHANCE FOR T-STORMS SLIGHTLY BETTER ON THURSDAY...ESPLY IN
THE HIGH COUNTRY. COULD SEE A REPEAT ON FRIDAY IF THE GFS IS
CORRECT. WHEREAS THE ECMWF APPEARS DRIER AND LESS ACTIVE.
TEMPERATURES THROUGHOUT THE EXTENDED PERIOD ARE PROGGED TO REMAIN
ABOVE AVERAGE WITH THE WARMEST READINGS MID-WEEK.
AVIATION...WITH NEXT 12Z TAF ISSUANCE WILL LIKELY INCREASE
CHANCES OF TS THIS AFTERNOON WITH TEMPO FOR TS/GUSTY WINDS GIVEN
SIMILAR MOISTURE LEVELS COMPARED TO YESTERDAY. TIMING OF STORMS MAYBE
A BIT LATER TODAY WITH MORE CLOUD COVER EXPECTED DURING THE
MORNING HOURS.
HYDROLOGY...GIVEN PW VALUES AROUND AN INCH AGAIN TODAY...SOME OF
THE STRONGER STORMS CAPABLE OF PRODUCING UP TO 2 INCHES IN LESS
THAN ONE HOUR. THIS WOULD RESULT IN POSSIBLE FLASH FLOODING
ESPECIALLY IN BURN AREAS. HOWEVER STORM MOTIONS OF 10-15KT SHOULD
KEEP THINGS MOVING AND NOT RESULT IN ANY MAJOR FLASH FLOODING
TODAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....BAKER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
415 AM MDT SAT JUL 28 2012
.SHORT TERM...
(TODAY AND TONIGHT)
CURRENTLY...THE UPPER RIDGE AXIS REMAINED OVER WESTERN KS EARLY THIS
MORNING WITH THE VERY EVIDENT MONSOON PLUME BEING DRAWN UP ACROSS
THE 4 CORNERS AND INTO CO...AS PER RAP H5 ANALYSIS AND IR SATELLITE
IMAGERY. SFC OBS INDICATED THAT TEMPS HAD DROPPED INTO THE UPPER 50S
TO MID 60S FOR MOST PLAINS LOCATIONS AND DOWN TO AROUND 50F FOR THE
HIGH VALLEYS AS OF 330 AM. DEWPOINT TEMPS WERE FAIRLY UNIFORM FOR
THE CWA...IN THE MID 40S TO LOWER 50S.
TODAY AND TONIGHT...THE WEATHER TREND FOR TODAY LOOKS LIKE IT WILL
BE VERY SIMILAR TO FRIDAY...MINUS THE SPARK PROVIDED BY THE UPPER
DISTURBANCE THAT ROLLED ACROSS THE ROCKIES. PRECIPITABLE WATER
REMAINS AT OR SLIGHTLY ABOVE NORM...BUT UPPER AIR SOUNDINGS POINT
TO SOMEWHAT DRY LOW LEVELS. THE RIDGE AXIS REMAINING NEAR THE
CO/KS BORDER WILL IMPART A GRADUAL N-NE MOVEMENT FOR ANY STORMS
THAT DO DEVELOP OVER THE HIGHER TERRAIN THIS AFTN. MODELS ARE
HINTING AT A SFC BOUNDARY LURKING ALONG THE PALMER DVD THIS
AFTN...AND WHERE THIS BOUNDARY STALLS WILL BE A FOCUS AREA FOR
CONVECTION. DECIDED TO HOLD ONTO THE ONGOING FORECAST THAT KEEPS
THIS BOUNDARY PRIMARILY NORTH OF THE PALMER DVD...WITH CONVECTION
FIRING OVER MONUMENT HILL THIS AFTN BUT NOT ALONG KIOWA COUNTY.
EXPECT ANOTHER HOT DAY TODAY WITH MAX TEMPS RIGHT AROUND 100 F FOR
THE PLAINS...AND IN THE 80S FOR THE HIGH VALLEYS.
THE MAIN FORECAST CONCERN CONTINUES TO BE THE FLASH FLOOD POTENTIAL
FOR THE WALDO CANYON BURN SCAR THIS AFTN AND EVE. INDIVIDUAL STORMS
HAVE SHOWN SOME SPOTTY HIGHER RAINFALL RATES OVER THE PAST WEEK AND
LUCKILY HAVE SIDE-STEPPED THE BURN SCAR FOR THE MOST PART...BUT WITH
LITTLE CHANGE IN THE OVERALL PATTERN LOCALLY HEAVY RAINFALL REMAINS
A THREAT. MOORE
.LONG TERM...
(SUNDAY THROUGH SATURDAY)
CONCERNS ARE COVERAGE OF SLOW MOVING THUNDERSTORMS THROUGH THE
WEEK...ESPECIALLY MONDAY.
SUNDAY THROUGH MONDAY...UPPER RIDGE CENTERED OVER WESTERN US WILL
PROVIDE WEAK WEST TO SOUTHWEST FLOW ALOFT. A SHORTWAVE MOVING
SOUTHEAST THROUGH THE GREAT PLAINS WILL BRING A COUPLE OF
BOUNDARIES INTO EASTERN COLORADO. THE STRONGER PUSH OF
COOLER...AND SLIGHTLY MOISTER LOW LEVEL AIR WILL LIKELY OCCUR
SUNDAY NIGHT WITH EASTERLY UPSLOPE FLOW DEVELOPING ACROSS THE
PLAINS THROUGH THE DAY ON MONDAY. BUT...MONSOONAL MOISTURE
FORECAST TO MOVE MAINLY WEST AND NORTH OF THE CWA. ISOLATED TO
SCATTERED AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL
OCCUR...WITH BEST COVERAGE REMAINING OVER AND ADJACENT TO THE
MOUNTAINS. WEAK FLOW ALOFT WILL BRING THE THREAT FOR LOCALLY HEAVY
RAINFALL AND THE POSSIBILITY OF FLASH FLOODING...ESPECIALLY IF
CELLS DEVELOP OVER THE BURN SCARS...INCLUDING THE WALDO CANYON
BURN SCAR. MID LEVEL TEMPERATURES WILL BE A BIT LOWER ON MONDAY
ACROSS THE PLAINS...BUT STILL...TEMPERATURES WILL BE ABOVE
SEASONAL AVERAGES BOTH DAYS.
TUESDAY-FRIDAY...UPPER LEVEL RIDGE FORECAST TO PERSIST JUST SOUTH
OF THE AREA...WITH RESULTANT WEAK WESTERLY FLOW ALOFT. MODELS
ALSO NOT TOO HEAVY HANDED WITH THE MONSOON MOISTURE. THERE WILL BE
ENOUGH MOISTURE FOR DAILY ISOLATED TO SCATTERED COVERAGE OF
PRECIPITATION WITH TEMPERATURES RISING A BIT FROM EARLY WEEKS
LEVELS. -TLM-
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED FOR THE THREE MAIN TAF SITES OF
KCOS...KPUB AND KALS FOR THE NEXT 24 HRS. HOWEVER...ISOLATED
CONVECTION WILL AFFECT KCOS AND KALS AFTER 18Z AND LASTING THROUGH
03Z...WITH THE MAIN THREAT BEING GUSTY WINDS OF 35-40 KTS. STORMS
WILL BE MORE SCATTERED OVER THE HIGHER TERRAIN...LINGERING THE
LONGEST OVER THE CONTDVD. THE STEERING FLOW IS FORECAST TO REMAIN
GENERALLY LIGHT AND FROM THE S-SW...SO ANY STORMS THAT FORM OVER THE
MTS WILL SLOWLY MOVE TO THE N-NE. MOORE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
27/13
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
152 AM EDT SAT JUL 28 2012
.PREV DISCUSSION... /ISSUED 1018 PM EDT FRI JUL 27 2012/
UPDATE...
CURRENT RADAR TREND SHOWS THE STRONG TSTMS THAT MOVED THROUGH CSG
AROUND 800 PM EDT ARE WEAKENING AND MOVING INTO SOUTHWEST GA.
OTHERWISE...THE AIRMASS OVER NORTH AND CENTRAL GA CONTINUES TO
STABILIZE. ONLY SCATTERED SPRINKLES OF LIGHT RAIN FROM MID LEVEL
MOISTURE FROM DISSIPATING TSTMS WAS OCCURRING OVER PORTIONS OF NORTH
GA. EXPECT ALL PRECIPITATION TO DIMINISH JUST AFTER MIDNIGHT. HAVE
LOWERED POPS ACCORDINGLY. PATCHY FOG WILL DEVELOP LATE TONIGHT
THROUGH SUNRISE IN AREAS WHERE MEASURABLE RAIN OCCURRED EARLIER
TODAY. OTHERWISE...NO OTHER CHANGES NEEDED AS FORECAST MIN TEMPS
ARE ON TRACK.
16
PREV DISCUSSION... /ISSUED 800 PM EDT FRI JUL 27 2012/
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MAIN FORECAST CONCERN IS THUNDERSTORM POTENTIAL THROUGH TOMORROW
ASSOCIATED WITH SEVERAL SHORTWAVES TRAVELING ALONG THE UPPER LEVEL
TROUGH SITUATED ACROSS THE EASTERN CONUS. A VERY MOIST AND UNSTABLE
ATMOSPHERE IS IN PLACE WITH MLCAPE VALUES OF NEAR 3000 J/KG AND PW
VALUES NEAR AND ABOVE 2.0 INCHES. SCATTERED SHOWER AND THUNDERSTORM
DEVELOPMENT HAS BEEN OCCURRING ACROSS THE FORECAST AREA EARLY THIS
AFTERNOON WITH A BIT BETTER ORGANIZED ACTIVITY ACROSS THE SOUTHERN
PORTION THAT INITIATED NEAR AN AREA OF ENHANCED BAROCLINICITY DUE TO
SOLAR SHELTERING FROM REMNANT CLOUD COVERAGE THIS MORNING. AMONG THE
ENSEMBLE OF AVAILABLE HI-RES GUIDANCE SOLUTIONS...THE HRRR SO FAR
HAS BEEN VERIFYING WELL WITH THE EARLY CONVECTIVE DEVELOPMENT AND IS
STARTING TO PICK UP MORE ON THE INFLUENCE OF THE SHORTWAVE IN THE
NORTHERN PORTION CLOSER TO 00Z THIS EVENING. THE WRF IS A BIT MORE
ROBUST WITH THIS LATER DEVELOPMENT. WILL THEREFORE EXPECT SEVERAL
ROUNDS OF DEVELOPMENT FROM THIS AFTERNOON THROUGH TONIGHT WITH THE
MORE ORGANIZED DEVELOPMENT AND GREATER SEVERE POTENTIAL OCCURRING
FROM ABOUT 23-02Z ACROSS THE NORTH. SPC ALSO HAS THIS AREA INCLUDED
IN A SLIGHT RISK. THE MAIN THREATS WILL BE STRONG WINDS AND HEAVY
RAINFALL WITH DOWNDRAFT CAPE ALREADY NEAR 1000 J/KG ACROSS THE NORTH
AND MUCH HYDROMETER LOADING EXPECTED WITH SUCH A MOIST THERMAL
PROFILE. FREQUENT LIGHTNING AND SMALL HAIL WILL ALSO BE POSSIBLE.
ISOLATED SEVERE STORM POTENTIAL IS ACROSS THE SOUTH AS WELL AS THE
MORE ENHANCED MOISTURE FIELD RESIDES NEAR A PERSISTENT SFC TROUGH.
HAVE GONE WITH LIKELY POPS IN THE NORTH AND SOUTH FROM 21-00Z
TRENDING INTO CHANCE POPS TONIGHT AND DECREASING TO SLIGHT ACROSS
THE NORTH NEAR EARLY MORNING.
MAINTAINING CHANCE POPS ACROSS SOUTHERN PORTION OVERNIGHT AND
EXPANDING BACK ACROSS MAJORITY OF AREA ON SATURDAY AS THE NAM
SUGGESTS ANOTHER SHORTWAVE RIPPLING ALONG UPPER TROUGH. GUIDANCE IS
IN GENERAL AGREEMENT WITH THE MAIN TROUGH AXIS LINGERING NEAR THE
EASTERN PORTION OF THE AREA INTO SUNDAY. PORTIONS OF THE SOUTH AND
EAST WILL THEREFORE HAVE SLIGHT TO CHANCE POPS OVERNIGHT SATURDAY.
FOR TEMPS...BLEND OF MAV AND MET LOOKS REASONABLE WITH GENERALLY
LOWER TEMPS THAN PREVIOUS DAYS AND INCREASED CLOUD COVERAGE
EXPECTED. ATTM THE PROGGED TEMPS AND DEWPOINTS DO NOT MEET HEAT
ADVISORY CRITERIA FOR SATURDAY... SO AM CURRENTLY PLANNING ON NO
ADDITIONAL ISSUANCE.
BAKER
LONG TERM /SUNDAY THROUGH FRIDAY/...
NOT MUCH CHANGE TO THE PREVIOUS GRIDS. DID INCREASE POPS ON SUNDAY
IN RESPONSE TO THE WEAK STATIONARY FRONT AND PROXIMITY OF THE
TROUGH AXIS...PROGGED TO BE PRETTY MUCH PARKED OVER THE
APPALACHIANS DURING THE DAY ON SUNDAY...WITH A SHORTWAVE PUSHING
INTO THE AREA. BEST CHANCES WILL BE IN THE SOUTHEAST HALF TO 2/3
OF THE FORECAST AREA...BUT CANNOT RULE OUT TOPOGRAPHICALLY-INDUCED
CONVECTION IN THE NORTHEAST MOUNTAINS. THE NAM GOES A LITTLE NUTS
WITH CONVECTION AS THE RESULT OF A VORT LOBE RIDING DOWN THE FLOW
ALOFT. ECMWF DOES ACTUALLY HAVE SOMETHING SIMILAR BUT WITH LESS
CONVECTIVE FEEDBACK AND THUS A MORE REASONABLE QPF FIELD.
OTHERWISE...ONLY MINOR CHANGES MADE TO THE EXTENDED PARTIALLY TO
ACCOUNT FOR NEW GUIDANCE MODERATING THE TEMPS SOMEWHAT MONDAY INTO
TUESDAY. SEE PREVIOUS DISCUSSION BELOW.
TDP
&&
.AVIATION...
06Z UPDATE...
A FRONT WILL SAG INTO THE AREA TODAY ALLOWING FOR GREATEST
MOISTURE AND TSRA CHANCES TO RESIDE OVER THE SOUTHERN MOST
TERMINALS OF CSG AND MCN. VERY TEMPTING TO REMOVE ALL MENTION OF
CONVECTION BASED ON MODEL PROJECTIONS BUT GOOD SHOT OF UPPER LEVEL
ENERGY ARRIVES LATE AND FEEL IT WILL BE JUST ENOUGH TO PRODUCE SCT
TSRA AT THE ATL ARE TERMINALS. TIMING IS DIFFICULT TO PIN DOWN BUT
LOOKS TO BE A LATE EVENING OR EVEN OVERNIGHT SCENARIO AT THIS POINT.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON TSRA CHANCES.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 95 72 94 70 / 40 20 20 20
ATLANTA 93 75 92 72 / 40 10 20 10
BLAIRSVILLE 89 66 88 64 / 30 10 20 20
CARTERSVILLE 93 70 92 67 / 30 10 10 20
COLUMBUS 94 76 93 74 / 40 20 30 10
GAINESVILLE 91 73 93 71 / 30 20 20 20
MACON 94 74 94 71 / 40 20 30 20
ROME 94 70 93 67 / 30 10 10 20
PEACHTREE CITY 93 70 91 67 / 40 20 20 10
VIDALIA 95 76 94 74 / 40 30 30 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1254 PM CDT SAT JUL 28 2012
.DISCUSSION...
ISSUED 1045 AM CDT SAT JUL 28 2012
WILL BE UPDATING THE FORECAST TODAY FOR MORE CLOUD COVER TODAY AND
MAY NEED TO ADD SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON NW OF THE IL RIVER. OTHERWISE REST OF FORECAST
LOOKS OK WITH HIGHS RANGING FROM THE MID 80S FROM LINCOLN NW TO
THE LOWER 90S IN SE IL. A WEAK/SMALL MCS OVER CENTRAL/NW IA INTO
SE SD AND SW MN IS SPREADING MID/HIGH CLOUDS QUICKLY SE INTO
CENTRAL IL THIS MORNING. ALSO HAVE SCATTERED CUMULUS CLOUDS
DEVELOPING BY LATE MORNING ACROSS AREAS EAST OF I-55 WITH BROKEN
CEILINGS OVER PARTS OF CENTRAL INDIANA. MODELS WEAKEN SHOWERS AND
THUNDERSTORMS OVER CENTRAL AND NW IA AS THEY TRACK SE INTO NW IL
THIS AFTERNOON. NAM KEEPS IT DRY OVER CWA THROUGH TONIGHT BUT HRRR
BRINGS PATCHES OF QPF INTO AREAS ALONG AND NORTH OF I-74 LATER
THIS AFTERNOON AND EVENING. WITH SEVERE TO EXTREME DROUGHT OVER
CENTRAL IL...THINK HRRR IS OVERDOING QPF BUT THINK NAM MAY BE TOO
DRY INTO TONIGHT SO WILL USE A BLEND THERE.
KH
&&
.AVIATION...
ISSUED 1250 PM CDT SAT JUL 28 2012
VFR CONDITIONS ARE GENERALLY EXPECTED TO CONTINUE ACROSS THE
CENTRAL IL TERMINAL AIRPORTS THROUGH 18Z/1 PM SUNDAY. VFR BROKEN
CEILINGS OF 3.5-5K FT POSSIBLE THIS AFTERNOON EAST OF I-55
ESPECIALLY AT BMI...DEC AND CMI AIRPORTS WHILE BROKEN MID/HIGH
CLOUDS 12-20K FT CONTINUE TO STREAM SE ACROSS CENTRAL IL FROM IA.
SHOWERS AND ISOLATED THUNDERSTORM COMPLEX OVER CENTRAL IA TO
WEAKEN AS IT MOVES SE INTO NW IL THIS AFTERNOON. MODELS DIFFER
WITH EVOLUTION OF CONVECTION DEVELOPMENT TONIGHT BUT CONSENSUS IS
KEEPING MOST OF CENTRAL IL DRY TONIGHT WITH VCSH AT PIA LATE
TONIGHT INTO SUNDAY MORNING AND POSSIBLY APPROACHING I-55 DURING
SUNDAY MORNING. WITH SEVERE TO EXTREME DROUGHT OVER CENTRAL IL
THINK ANY CONVECTION THAT TRIES TO MOVE INTO CENTRAL IL WILL WEAKEN
AND DISSIPATE THROUGH TONIGHT. A LITTLE BETTER CHANCES OF ISOLATED
CONVECTION SUNDAY AFTERNOON AND SUNDAY NIGHT BEYOND THE 24 HOUR
TAF PERIOD. NW WINDS 5-10 KTS THIS AFTERNOON TO VEER EAST TONIGHT
AND SSE SUNDAY MORNING AT 7-11 KTS.
KH
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT JUL 28 2012
LATEST SFC ANALYSIS INDICATED HIGH PRESSURE OVER THE UPPER
MIDWEST. THIS PROVIDED LIGHT NORTHERLY WINDS AND SLIGHTLY
COOLER/LESS HUMID AIR. ALOFT...NORTHWEST MID LEVEL FLOW PREVAILED
FOR MUCH OF THE MIDWEST...BETWEEN AN EASTERN GREAT LAKES TROUGH
AND STRONG CENTRAL PLAINS RIDGING. MAIN FORECAST ISSUE CONTINUES TO
BE TRYING TO PIN DOWN PRECIP CHANCES IN NORTHWEST FLOW...AS OUR
AREA LOOKS TO BE ON THE EDGE OF THE HEAT DOME FOR MUCH OF THE FORECAST.
SHORT TERM...TODAY THROUGH MONDAY
SURFACE HIGH DRIFTS SOUTHEAST THROUGH THE EASTERN GREAT LAKES THIS
WEEKEND. THIS WILL PROVIDE A NORTH/EAST WIND FLOW TODAY WHICH
KEEPS TEMPERATURES NEAR TO SLIGHTLY ABOVE NORMAL. SOUTHERLY WINDS
ON THE BACK SIDE OF THE HIGH WILL WARM TEMPS A FEW MORE DEGREES
SUNDAY. FOR RAIN CHANCES...TO OUR WEST...MID LEVEL THERMAL
GRADIENT...LOW-LEVEL JET...AND SHORTWAVES TOPPING THE UPPER LEVEL
RIDGE WILL PRODUCE NIGHTLY MCS ACTIVITY. THE FIRST OF THESE WAVES
CURRENTLY OVER THE SD/NEBRASKA BORDER IS FORECAST TO SPREAD
THUNDERSTORMS INTO IOWA TODAY BEFORE DISSIPATING. MAIN IMPACT
LOCALLY WOULD BE AN INCREASE MID/HIGH LEVEL CLOUDS. NEXT
DISTURBANCE IS PROGGED TO DEVELOP STORMS OVER CENTRAL IOWA AFTER
06Z TONIGHT AND DROP SOUTHEAST ALONG MID LEVEL THERMAL/MOISTURE
GRADIENT. CONDITIONS ARE LESS FAVORABLE FOR THIS ACTIVITY TO HOLD
TOGETHER AS IS SHIFTS EAST OF THE MISSISSIPPI RIVER SUNDAY
MORNING. HAVE LIMITED POPS TO LOW CHANCE IN THE WEST...WITH SLIGHT
CHANCES FARTHER EAST. A SOMEWHAT BETTER SETUP FOR THUNDERSTORMS
SETS UP OVER THE AREA SUNDAY NIGHT INTO MONDAY WITH A MORE
FAVORABLE LOW-LEVEL JET ORIENTATION AND THETA-E GRADIENT...HOWEVER
FORCING IS NOT THAT IMPRESSIVE AND AGAIN LIMITED POPS TO LOW
CHANCE.
LONG TERM...TUESDAY THROUGH FRIDAY
LITTLE CHANGE IN THE OVERALL SYNOPTIC PATTERN IS SHOWN BY
TONIGHTS 00Z MEDIUM RANGE MODELS. A GENERAL NORTHWEST MID-LEVEL
FLOW CONTINUES AS THE STRONG SOUTHERN PLAINS RIDGE PERSISTS.
ACCEPTED ECMWF 850 MB TEMPS WARM TO +20C OR GREATER WHICH WOULD
SUPPORT ANOTHER STRETCH OF WARM WEATHER WITH HIGHS IN THE 90S AND
LOWS IN THE 70S. HOWEVER...THIS PATTERN DOES NOT APPEAR NEARLY AS
HOT AS LAST WEEK. PRECIP CHANCES WILL BE HIGHLY DEPENDENT ON
SHORTWAVES MOVING THROUGH IN FASTER FLOW ON THE PERIPHERY OF THE
HOT/CAPPED AIRMASS CENTERED TO OUR WEST. THIS WILL BE REFINED IN
LATER FORECASTS BUT GIVEN EXTREME DROUGHT HAVE KEPT POPS TO SLIGHT
CHANCE OR LESS.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT SAT JUL 28 2012
.DISCUSSION...
ISSUED 1045 AM CDT SAT JUL 28 2012
WILL BE UPDATING THE FORECAST TODAY FOR MORE CLOUD COVER TODAY AND
MAY NEED TO ADD SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS LATE
THIS AFTERNOON NW OF THE IL RIVER. OTHERWISE REST OF FORECAST
LOOKS OK WITH HIGHS RANGING FROM THE MID 80S FROM LINCOLN NW TO
THE LOWER 90S IN SE IL. A WEAK/SMALL MCS OVER CENTRAL/NW IA INTO
SE SD AND SW MN IS SPREADING MID/HIGH CLOUDS QUICKLY SE INTO
CENTRAL IL THIS MORNING. ALSO HAVE SCATTERED CUMULUS CLOUDS
DEVELOPING BY LATE MORNING ACROSS AREAS EAST OF I-55 WITH BROKEN
CEILINGS OVER PARTS OF CENTRAL INDIANA. MODELS WEAKEN SHOWERS AND
THUNDERSTORMS OVER CENTRAL AND NW IA AS THEY TRACK SE INTO NW IL
THIS AFTERNOON. NAM KEEPS IT DRY OVER CWA THROUGH TONIGHT BUT HRRR
BRINGS PATCHES OF QPF INTO AREAS ALONG AND NORTH OF I-74 LATER
THIS AFTERNOON AND EVENING. WITH SEVERE TO EXTREME DROUGHT OVER
CENTRAL IL...THINK HRRR IS OVERDOING QPF BUT THINK NAM MAY BE TOO
DRY INTO TONIGHT SO WILL USE A BLEND THERE.
KH
&&
.AVIATION...
ISSUED 627 AM CDT SAT JUL 28 2012
FAIRLY QUIET WEATHER IS IN STORE FOR TODAY... WITH VFR CONDITIONS
EXPECTED THROUGH THIS TAF CYCLE. HIGH CLOUDS WILL SPREAD ACROSS THE
TERMINALS LATER THIS AFTERNOON AND PERSIST THROUGH THE OVERNIGHT.
MODELS HINT THAT SOME SHOWERS COULD DEVELOP TOWARDS THE END OF THE
PERIOD AT PIA/SPI AS AN UPPER LEVEL DISTURBANCE DROPS SOUTHEAST INTO
THE AREA...HOWEVER CONFIDENCE IS TOO LOW IN THIS OCCURRING BEFORE
12Z SO WILL LEAVE OUT MENTION FOR NOW. WINDS WILL MOSTLY BE OUT THE
NORTH/NORTHEAST TODAY...AND THEN GRADUALLY VEER TO THE EAST LATE
TONIGHT. SPEEDS WILL BE 10 KTS OR LESS.
ECT/SMITH
&&
.PREV DISCUSSION...
ISSUED 242 AM CDT SAT JUL 28 2012
LATEST SFC ANALYSIS INDICATED HIGH PRESSURE OVER THE UPPER
MIDWEST. THIS PROVIDED LIGHT NORTHERLY WINDS AND SLIGHTLY
COOLER/LESS HUMID AIR. ALOFT...NORTHWEST MID LEVEL FLOW PREVAILED
FOR MUCH OF THE MIDWEST...BETWEEN AN EASTERN GREAT LAKES TROUGH
AND STRONG CENTRAL PLAINS RIDGING. MAIN FORECAST ISSUE CONTINUES TO
BE TRYING TO PIN DOWN PRECIP CHANCES IN NORTHWEST FLOW...AS OUR
AREA LOOKS TO BE ON THE EDGE OF THE HEAT DOME FOR MUCH OF THE FORECAST.
SHORT TERM...TODAY THROUGH MONDAY
SURFACE HIGH DRIFTS SOUTHEAST THROUGH THE EASTERN GREAT LAKES THIS
WEEKEND. THIS WILL PROVIDE A NORTH/EAST WIND FLOW TODAY WHICH
KEEPS TEMPERATURES NEAR TO SLIGHTLY ABOVE NORMAL. SOUTHERLY WINDS
ON THE BACK SIDE OF THE HIGH WILL WARM TEMPS A FEW MORE DEGREES
SUNDAY. FOR RAIN CHANCES... TO OUR WEST...MID LEVEL THERMAL
GRADIENT...LOW-LEVEL JET...AND SHORTWAVES TOPPING THE UPPER LEVEL
RIDGE WILL PRODUCE NIGHTLY MCS ACTIVITY. THE FIRST OF THESE WAVES
CURRENTLY OVER THE SD/NEB BORDER IS FORECAST TO SPREAD
THUNDERSTORMS INTO IOWA TODAY BEFORE DISSIPATING. MAIN IMPACT
LOCALLY WOULD BE AN INCREASE MID/HIGH LEVEL CLOUDS. NEXT
DISTURBANCE IS PROGGED TO DEVELOP STORMS OVER CENTRAL IOWA AFTER
06Z TONIGHT AND DROP SOUTHEAST ALONG MID LEVEL THERMAL/MOISTURE
GRADIENT. CONDITIONS ARE LESS FAVORABLE FOR THIS ACTIVITY TO HOLD
TOGETHER AS IS SHIFTS EAST OF THE MISSISSIPPI RIVER SUNDAY
MORNING. HAVE LIMITED POPS TO LOW CHANCE IN THE WEST...WITH SLIGHT
CHANCES FARTHER EAST. A SOMEWHAT BETTER SETUP FOR THUNDERSTORMS
SETS UP OVER THE AREA SUNDAY NIGHT INTO MONDAY WITH A MORE
FAVORABLE LOW-LEVEL JET ORIENTATION AND THETA-E GRADIENT...HOWEVER
FORCING IS NOT THAT IMPRESSIVE AND AGAIN LIMITED POPS TO LOW
CHANCE.
LONG TERM...TUESDAY THROUGH FRIDAY
LITTLE CHANGE IN THE OVERALL SYNOPTIC PATTERN IS SHOWN BY
TONIGHTS 00Z MEDIUM RANGE MODELS. A GENERAL NORTHWEST MID-LEVEL
FLOW CONTINUES AS THE STRONG SOUTHERN PLAINS RIDGE PERSISTS.
ACCEPTED ECMWF 850 MB TEMPS WARM TO +20C OR GREATER WHICH WOULD
SUPPORT ANOTHER STRETCH OF WARM WEATHER WITH HIGHS IN THE 90S AND
LOWS IN THE 70S. HOWEVER...THIS PATTERN DOES NOT APPEAR NEARLY AS
HOT AS LAST WEEK. PRECIP CHANCES WILL BE HIGHLY DEPENDENT ON
SHORTWAVES MOVING THROUGH IN FASTER FLOW ON THE PERIPHERY OF THE
HOT/CAPPED AIRMASS CENTERED TO OUR WEST. THIS WILL BE REFINED IN
LATER FORECASTS BUT GIVEN EXTREME DROUGHT HAVE KEPT POPS TO SLIGHT
CHANCE OR LESS.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1251 PM EDT SAT JUL 28 2012
.AVIATION... / 18Z TAFS /
NORTHERLY WINDS NEAR 10 KNOTS WILL BECOME LIGHT/VARIABLE TONIGHT
INTO TOMORROW MORNING AS SFC HIGH PRESSUIRE BUILDS INTO THE
REGION. AS FOR CIGS...MAINLY SKC AT SBN WITH A GRADUAL INCREASE IN
HIGH CLOUDS POSSIBLE BY LATER TONIGHT. FWA IS ON THE EASTERN
FRINGE OF A STRATO CU DECK NEAR 3 KFT. CONTINUED MIXING/SUBSIDENCE
SHOULD ALLOWING CIGS TO CONTINUE TO SCATTER OUT THIS AFTERNOON AND
INCREASE TO 4-5 KFT. OTHERWISE...TEMPS TONIGHT MAY NEAR XOVER
VALUES AT FWA POSSIBLY SUPPORTING A BRIEF PERIOD OF BR AROUND
DAYBREAK. LEFT ANY BR MENTION OUT OF THE FCST FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 700 AM EDT SAT JUL 28 2012/
SHORT TERM...
TODAY THROUGH SUNDAY NIGHT. BENIGN PATTERN IN SHORT
TERM PD. 1021 MB SFC HIGH ACRS NRN WI TO DROP SLOWLY SEWD INTO LWR
GRTLKS BY MON AM. STATIC MIDLVL REGIME FEATURING STRONG OK/NRN TX
RIDGE CENTER WITH MULTIPLE SHORTWAVES RIDING BROAD WRLIES ACRS NRN
PLAINS/SRN CANADA...THEN TRACKING INTO MEAN ERN STATES TROF.
ANTICIPATE FURTHER EXPANSION WITHIN 925MB THERMAL TROF ACRS SRN
MI/NRN IN THIS AM AMID TURBULENT N-NERLY 10-15KT FLOW PER KDTX VWP
AND RAP POINT SNDGS. RAPID MIXOUT OF CLOUDS COINCIDENT WITH RAPID
EROSION OF LOW BASED SUBSIDENCE INVERSION/RAPID RISING
CCL/ENTRAINMENT OF SIG DRIER AIR ALOFT. SLIGHT DOWNWARD NUDGE IN
TEMPS TODAY PER AM CLOUD COVER/DEEP NRLY FLOW/GUID
CLUSTERING/SIMILAR THERMAL REGIME AS SEEN YDAY ACRS SRN WI. SLIGHT
NUDGE TOWARD NAM/ECMWF WRT NEXT MINIMAL TSRA CHCS ACRS SWRN CWA
LATE SUNDAY NIGHT/ERLY MONDAY MORNING. RATHER WEAK PIECEMEAL
ENERGY ACRS WRN/CNTL MT EMANATING FM STRONGER SRN BC VORTEX TO
TRACK INTO CNTL MS VLY LATE DY2. PSBL MCS DVLPG ACRS KS/MO SUNDAY
EVENING WITH EWD MAINTENANCE PER RAMPING NOCTURNAL JETLET INTO
ECNTL MO OVERNIGHT. EWD PUSH OF EML MAY BE LIMITED PER MORE VEERED
FLOW WITH ERN EXTENT AND RELEGATE HIEST CHCS ACRS CNTL IL/CNTL IN
TOWARD DAYBREAK...AND HAVE OMITTED MENTION ACRS NRN CWA 06-12 UTC
MON.
LONG TERM... /MONDAY THROUGH FRIDAY.
IN COORDINATION WITH SHORT TERM PERIOD...HAVE OPTED TO LOWER POPS
MON/MON NGT GIVEN INCREASING SIGNALS FROM ECMWF AND GEFS OF LITTLE
OR NO PRECIP OCCURRING AS WEAK WAVE SET TO MOVE THROUGH LATE SUN
INTO MONDAY WILL BE SERIOUSLY LACKING ANY MSTR OR SIG
LIFT...LIMITING ITS EFFECTS MAINLY TO INCREASE IN MID LEVEL CLOUDS
AND MAYBE SOME LIGHT SHOWERS. SOMEWHAT STRONGER WAVES WILL MOVE
ACROSS THE NORTHERN/CENTRAL GREAT LAKES TUESDAY AND AGAIN THURSDAY.
WITH NW FLOW IN PLACE...MSTR WILL REMAIN CUT OFF WITH THESE SYSTEMS
AS WELL...BUT AT LEAST A BIT MORE IN THE WAY OF DYNAMICS WITH EACH
WAVE TO HANG ONTO CHC/SLGT CHC POPS...MAINLY IN NORTH AND EAST
SECTIONS.
WITH LITTLE CHANGE IN OVERALL FLOW...TEMPERATURES SHOULD REMAIN IN
THE 85 TO 90 DEGREE RANGE MUCH OF THE PERIOD WITH LOWER READING SEEN
WITH PASSAGE OF EACH WAVE AND ASSOCIATED CLOUDS/PRECIP. BY
FRIDAY...SLIGHTLY COOLER AIR MAY ARRIVE BEHIND THE THURSDAY
SYSTEM...BUT WILL ONLY SHAVE A FEW DEGREES OFF HIGHS COMPARED TO THE
REST OF THE WEEK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK UNTIL 7 PM CDT THIS EVENING FOR INZ003.
MI...RIP CURRENT RISK UNTIL 8 PM EDT THIS EVENING FOR MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...STEINWEDEL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
700 AM EDT SAT JUL 28 2012
.AVIATION... /12 UTC TAFS/
LITTLE CHANGE WRT LATEST NRN IN TAFS. MORE SOLID MVFR STRATOCU DECK
INTO NERN IN ATTM...WITHIN HEART OF LLVL THERMAL TROF...WITH WRN
FRINGE INVOF KSBN. STILL SOME MVFR CU REGEN PSBL THIS AM FOR BRIEF
MVFR CIGS AT KSBN WITH INCRSD TURBULENT MIXING. SOME CONCERN LATE IN
FCST PD FOR SHALLOW/PATCHY BR FORMATION NEAR SUNRISE...ESPCLY AT
KFWA WITH SLIGHTLY HIR XOVER TEMP.
&&
.SHORT TERM...
TODAY THROUGH SUNDAY NIGHT. BENIGN PATTERN IN SHORT TERM PD. 1021 MB
SFC HIGH ACRS NRN WI TO DROP SLOWLY SEWD INTO LWR GRTLKS BY MON AM.
STATIC MIDLVL REGIME FEATURING STRONG OK/NRN TX RIDGE CENTER WITH
MULTIPLE SHORTWAVES RIDING BROAD WRLIES ACRS NRN PLAINS/SRN
CANADA...THEN TRACKING INTO MEAN ERN STATES TROF. ANTICIPATE FURTHER
EXPANSION WITHIN 925MB THERMAL TROF ACRS SRN MI/NRN IN THIS AM AMID
TURBULENT N-NERLY 10-15KT FLOW PER KDTX VWP AND RAP POINT SNDGS.
RAPID MIXOUT OF CLOUDS COINCIDENT WITH RAPID EROSION OF LOW BASED
SUBSIDENCE INVERSION/RAPID RISING CCL/ENTRAINMENT OF SIG DRIER AIR
ALOFT. SLIGHT DOWNWARD NUDGE IN TEMPS TODAY PER AM CLOUD COVER/DEEP
NRLY FLOW/GUID CLUSTERING/SIMILAR THERMAL REGIME AS SEEN YDAY ACRS
SRN WI. SLIGHT NUDGE TOWARD NAM/ECMWF WRT NEXT MINIMAL TSRA CHCS
ACRS SWRN CWA LATE SUNDAY NIGHT/ERLY MONDAY MORNING. RATHER WEAK
PIECEMEAL ENERGY ACRS WRN/CNTL MT EMANATING FM STRONGER SRN BC
VORTEX TO TRACK INTO CNTL MS VLY LATE DY2. PSBL MCS DVLPG ACRS KS/MO
SUNDAY EVENING WITH EWD MAINTENANCE PER RAMPING NOCTURNAL JETLET
INTO ECNTL MO OVERNIGHT. EWD PUSH OF EML MAY BE LIMITED PER MORE
VEERED FLOW WITH ERN EXTENT AND RELEGATE HIEST CHCS ACRS CNTL
IL/CNTL IN TOWARD DAYBREAK...AND HAVE OMITTED MENTION ACRS NRN CWA
06-12 UTC MON.
&&
.LONG TERM... /MONDAY THROUGH FRIDAY.
IN COORDINATION WITH SHORT TERM PERIOD...HAVE OPTED TO LOWER POPS
MON/MON NGT GIVEN INCREASING SIGNALS FROM ECMWF AND GEFS OF LITTLE
OR NO PRECIP OCCURRING AS WEAK WAVE SET TO MOVE THROUGH LATE SUN
INTO MONDAY WILL BE SERIOUSLY LACKING ANY MSTR OR SIG
LIFT...LIMITING ITS EFFECTS MAINLY TO INCREASE IN MID LEVEL CLOUDS
AND MAYBE SOME LIGHT SHOWERS. SOMEWHAT STRONGER WAVES WILL MOVE
ACROSS THE NORTHERN/CENTRAL GREAT LAKES TUESDAY AND AGAIN THURSDAY.
WITH NW FLOW IN PLACE...MSTR WILL REMAIN CUT OFF WITH THESE SYSTEMS
AS WELL...BUT AT LEAST A BIT MORE IN THE WAY OF DYNAMICS WITH EACH
WAVE TO HANG ONTO CHC/SLGT CHC POPS...MAINLY IN NORTH AND EAST
SECTIONS.
WITH LITTLE CHANGE IN OVERALL FLOW...TEMPERATURES SHOULD REMAIN IN
THE 85 TO 90 DEGREE RANGE MUCH OF THE PERIOD WITH LOWER READING SEEN
WITH PASSAGE OF EACH WAVE AND ASSOCIATED CLOUDS/PRECIP. BY
FRIDAY...SLIGHTLY COOLER AIR MAY ARRIVE BEHIND THE THURSDAY
SYSTEM...BUT WILL ONLY SHAVE A FEW DEGREES OFF HIGHS COMPARED TO THE
REST OF THE WEEK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK THROUGH THIS EVENING FOR INZ003.
MI...RIP CURRENT RISK THROUGH THIS EVENING FOR MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
459 AM EDT SAT JUL 28 2012
.SHORT TERM...
TODAY THROUGH SUNDAY NIGHT. BENIGN PATTERN IN SHORT TERM PD. 1021 MB
SFC HIGH ACRS NRN WI TO DROP SLOWLY SEWD INTO LWR GRTLKS BY MON AM.
STATIC MIDLVL REGIME FEATURING STRONG OK/NRN TX RIDGE CENTER WITH
MULTIPLE SHORTWAVES RIDING BROAD WRLIES ACRS NRN PLAINS/SRN
CANADA...THEN TRACKING INTO MEAN ERN STATES TROF. ANTICIPATE FURTHER
EXPANSION WITHIN 925MB THERMAL TROF ACRS SRN MI/NRN IN THIS AM AMID
TURBULENT N-NERLY 10-15KT FLOW PER KDTX VWP AND RAP POINT SNDGS.
RAPID MIXOUT OF CLOUDS COINCIDENT WITH RAPID EROSION OF LOW BASED
SUBSIDENCE INVERSION/RAPID RISING CCL/ENTRAINMENT OF SIG DRIER AIR
ALOFT. SLIGHT DOWNWARD NUDGE IN TEMPS TODAY PER AM CLOUD COVER/DEEP
NRLY FLOW/GUID CLUSTERING/SIMILAR THERMAL REGIME AS SEEN YDAY ACRS
SRN WI. SLIGHT NUDGE TOWARD NAM/ECMWF WRT NEXT MINIMAL TSRA CHCS
ACRS SWRN CWA LATE SUNDAY NIGHT/ERLY MONDAY MORNING. RATHER WEAK
PIECEMEAL ENERGY ACRS WRN/CNTL MT EMANATING FM STRONGER SRN BC
VORTEX TO TRACK INTO CNTL MS VLY LATE DY2. PSBL MCS DVLPG ACRS KS/MO
SUNDAY EVENING WITH EWD MAINTENANCE PER RAMPING NOCTURNAL JETLET
INTO ECNTL MO OVERNIGHT. EWD PUSH OF EML MAY BE LIMITED PER MORE
VEERED FLOW WITH ERN EXTENT AND RELEGATE HIEST CHCS ACRS CNTL
IL/CNTL IN TOWARD DAYBREAK...AND HAVE OMITTED MENTION ACRS NRN CWA
06-12 UTC MON.
&&
.LONG TERM... /MONDAY THROUGH FRIDAY.
IN COORDINATION WITH SHORT TERM PERIOD...HAVE OPTED TO LOWER POPS
MON/MON NGT GIVEN INCREASING SIGNALS FROM ECMWF AND GEFS OF LITTLE
OR NO PRECIP OCCURRING AS WEAK WAVE SET TO MOVE THROUGH LATE SUN
INTO MONDAY WILL BE SERIOUSLY LACKING ANY MSTR OR SIG
LIFT...LIMITING ITS EFFECTS MAINLY TO INCREASE IN MID LEVEL CLOUDS
AND MAYBE SOME LIGHT SHOWERS. SOMEWHAT STRONGER WAVES WILL MOVE
ACROSS THE NORTHERN/CENTRAL GREAT LAKES TUESDAY AND AGAIN THURSDAY.
WITH NW FLOW IN PLACE...MSTR WILL REMAIN CUT OFF WITH THESE SYSTEMS
AS WELL...BUT AT LEAST A BIT MORE IN THE WAY OF DYNAMICS WITH EACH
WAVE TO HANG ONTO CHC/SLGT CHC POPS...MAINLY IN NORTH AND EAST
SECTIONS.
WITH LITTLE CHANGE IN OVERALL FLOW...TEMPERATURES SHOULD REMAIN IN
THE 85 TO 90 DEGREE RANGE MUCH OF THE PERIOD WITH LOWER READING SEEN
WITH PASSAGE OF EACH WAVE AND ASSOCIATED CLOUDS/PRECIP. BY
FRIDAY...SLIGHTLY COOLER AIR MAY ARRIVE BEHIND THE THURSDAY
SYSTEM...BUT WILL ONLY SHAVE A FEW DEGREES OFF HIGHS COMPARED TO THE
REST OF THE WEEK.
&&
.AVIATION...
MOIST 950-900 MB LYR ACROSS SOUTHERN MICHIGAN WITH SUFFICIENT
TURBULENT MIXING IN BACKED/NERLY CLOUD LAYER FLOW TO AFFORD STRATUS
EXPANSION INTO NRN INDIANA ERLY THIS AM. RAPID MIXOUT OF SHALLOW
THERMAL TROF/SUBSIDENCE INVERSION TO AFFORD INCRSG CU/LCL THROUGH AM
HOURS...TO VFR MET CONDS BY 15 UTC THROUGH THE END OF FCST PD.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK THROUGH THIS EVENING FOR INZ003.
MI...RIP CURRENT RISK THROUGH THIS EVENING FOR MIZ077.
OH...NONE.
LM...NONE.
&&
$$
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1150 PM CDT FRI JUL 27 2012
.AVIATION...
VFR CONDITIONS WILL BE OVER MUCH OF THE AREA THROUGH THE PERIOD.
A BROAD AREA OF HIGH PRESSURE WILL KEEP LIGHT WINDS OVER THE AREA.
THE WIND DIRECTION WILL BE MAINLY FROM THE NORTH OVERNIGHT AND
WILL VEER TO THE EAST SATURDAY. THERE IS SOME POTENTIAL FOR MVFR
VSBYS LATE TONIGHT AT KDBQ WITH A WEAK AREA OF LOW LEVEL
CONVERGENCE IN THE VICINITY.
DLF
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT FRI JUL 27 2012/
SYNOPSIS...
12Z UA ANALYSIS HAD AN 850MB LOW NEAR KGRB WITH AN OCCLUDED FRONT
RUNNING INTO SOUTHWEST LOWER MICHIGAN. THE 850MB COLD FRONT RAN
FROM SOUTHWEST LOWER MICHIGAN INTO SOUTHERN NEBRASKA. SATELLITE
AND RADAR TRENDS THROUGH MID AFTERNOON SHOW PLENTY OF DIURNAL CU
WITH SHRA/TSRA ACROSS WISCONSIN.
18Z SFC ANALYSIS HAS A LOW NEAR KMKG WITH A COLD FRONT RUNNING
SOUTHWEST TO THE KSTL AREA AND THEN INTO NORTHEAST OKLAHOMA.
SEVERAL TROFS WERE BEHIND THE COLD FRONT FROM CENTRAL ILLINOIS
BACK NORTH INTO CENTRAL WISCONSIN. DEW POINTS WERE IN THE 50S AND
60S BEHIND THE FRONT WITH 60S AND 70S ACROSS THE OHIO VALLEY AND
DEEP SOUTH.
SHORT TERM...TONIGHT AND SATURDAY
THE FIRST QUESTION IS WILL DIURNAL CONVECTION DEVELOP LATE THIS
AFTERNOON. THE 20Z OBS INDICATE THE NORTHEAST CWFA IS WITHIN A FEW
DEGREES OF CONVECTIVE TEMPERATURE. IF CONVECTIVE TEMPERATURE CAN
BE REACHED BY 22Z AND A PARCEL CAN BE LIFTED TO THE LFC...
CONVECTION SHOULD ENSUE THAT DISSIPATES WITH SUNSET. RAP TRENDS
SHOW A WEAK THETA E GRADIENT DEVELOPING FROM ABOUT KPDC TO KSQI
WITH SOME FORCING ALONG IT. RADAR ALSO SHOWS SOME VERY WEAK
RETURNS BETWEEN KEFT AND KOVS IN SOUTHERN WISCONSIN.
SO...ALTHOUGH THE CHANCES ARE NOT GREAT...PROBABLY 1 IN 3... WILL
ADD A MENTION OF ISOLATED SHRA/TSRA VERY LATE THIS AFTERNOON UP TO
SUNSET. AT BEST THERE MAY ONLY BE A HANDFUL OF CELLS THAT DEVELOP.
IF NO CONVECTION DEVELOPS BY 2230Z...THE LATE AFTERNOON AND
EVENING IN THE NORTHEAST CWFA WILL LIKELY REMAIN DRY.
AS HIGH PRESSURE BUILDS INTO THE AREA LATE TONIGHT WINDS WILL
DIMINISH. AS TEMPERATURES DROP THE QUESTION THEN TURNS TO FOG
POTENTIAL. WHAT LITTLE RAIN THAT HAS OCCURRED RECENTLY HAS DONE
LITTLE TO MOISTEN THE GROUND. HOWEVER...A READY SOURCE OF MOISTURE
IS THE RIVERS. AN APPROACHING VORT MAX FROM THE PLAINS MAY ALLOW
SOME HIGH LEVEL CLOUDS TO SPILL INTO THE AREA PRIOR TO DAWN AND ANY
FOG DEVELOPMENT WILL BE VERY PATCHY. THUS WILL MENTION SOME PATCHY
RIVER VALLEY FOG IN THE NORTHERN CWFA LATE TONIGHT AND EARLY
SATURDAY MORNING.
MCS AND LIFT TOOLS ALL INDICATE A RESPECTABLE MCS SHOULD FIRE
TONIGHT IN THE PLAINS AND HEAD EAST. CLOUDS FROM THIS MCS SHOULD
SLOWLY OVERTAKE THE CWFA SATURDAY MORNING.
SATURDAY AFTERNOON...THE BETTER MOISTURE AND SUPPORT REMAIN WEST
OF THE CWFA PER THE MCS AND LIFT TOOLS. HOWEVER...DIURNAL HEATING
ON ANY OUTFLOW BOUNDARY FROM THE NOCTURNAL MCS SHOULD HELP
INITIATE CONVECTION IN CENTRAL IOWA THAT SLOWLY MOVES EAST. SO...
SCHC POPS FOR ISOLATED CONVECTION WILL BE ADDED TO THE FAR WESTERN
CWFA LATE SATURDAY AFTERNOON. TEMPERATURES ON SATURDAY SHOULD
AGAIN BE CLOSE TO NORMAL. ..08..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY
SATURDAY NIGHT WILL BE VERY INTERESTING. SEVERAL MODELS HAVE
INDICATIONS THAT AN MCS WILL FORM IN NORTH CENTRAL OR NORTHWEST
IOWA...ALONG AN INSTABILITY GRADIENT AND 850MB BAROCLINIC ZONE. THE
MODELS HAVE A LOT OF DIFFERENCES IN WHERE THE SURFACE FEATURES AND
QPF ARE FOR THIS EVENT...BUT THE MID LEVEL BAROCLINIC ZONE IS FAIRLY
SIMILAR...WHICH FAVORS THE NORTHWEST OR NORTH CENTRAL IOWA LOCATION.
THIS POTENTIAL AREA OF CONVECTION WOULD SLIDE SOUTHEAST SATURDAY
NIGHT...AND AFFECT MAINLY THE WESTERN HALF OF THE FORECAST AREA LATE
SATURDAY NIGHT AND SUNDAY. HAVE RAISED POPS FOR THIS AREA...BUT
HAVE STILL LEFT IN THE CHANCE CATEGORY AND WILL LET LATER SHIFTS
RE-EVALUATE. HAVE ALSO KEPT HIGH TEMPERATURES IN THE 80S TO NEAR 90
SUNDAY...KNOWING THAT IF THIS EVENT IS MORE WIDESPREAD THAN
ANTICIPATED...THIS FORECAST WILL BE TOO WARM.
SUNDAY NIGHT MODELS TRY TO START ANOTHER MCS SOMEWHERE IN THE
GENERAL VICINITY...BUT MCS TECHNIQUES ARE LESS FAVORABLE AND WOULD
INDICATE A LOCATION FARTHER EAST OR SOUTH. SO...HAVE KEPT POPS IN
THE SLIGHT OR LOW END CHANCE POP RANGE FOR SUNDAY NIGHT AND MONDAY FOR
NOW...AND WILL LET LATER SHIFTS REEVALUATE. WHAT HAPPENS SATURDAY
NIGHT AND SUNDAY WILL STRONGLY AFFECT WHAT HAPPENS SUNDAY NIGHT.
HIGH TEMPERATURES SHOULD INCREASE AS MID LEVEL WARM AIR SURGES IN
OUR DIRECTION...SO HIGHS SHOULD RANGE FROM THE UPPER 80S TO LOW 90S
WITH LOWS IN THE UPPER 60S TO LOW 70S.
TUESDAY THROUGH THURSDAY...GENERAL NORTHWEST FLOW ALOFT WITH THE
UPPER LEVEL RIDGE STALLED OUT WEST. DESPITE HAVING A SURFACE RIDGE
IN PLACE...THE MID LEVEL BAROCLINIC ZONE WILL BE IN THE GENERAL
VICINITY. A FEW PERIODS OF SHOWERS AND THUNDERSTORMS ARE POSSIBLE
IN THIS PERIOD...BUT IT IS TOUGH TO NARROW DOWN WHICH PERIODS OR
LOCATIONS WITH THE NECESSARY MESOSCALE FEATURES POORLY DEFINED AT
THIS TIME RANGE. THUS...AM CARRYING SEVERAL PERIODS OF JUST SLIGHT
CHANCE POPS. TEMPERATURES TO SLOWLY RISE THROUGH THE PERIOD...WITH
HIGHS BY THURSDAY IN THE UPPER 80S TO MID 90S. LOWS IN THE UPPER
60S TO LOW 70S.
FRIDAY THERE ARE SOME LARGE DIFFERENCES IN THE MODELS. IN THE
ECMWF...THE UPPER LEVEL RIDGE FLATTENS AGAIN...AND A SHORTWAVE
APPEARS TO DIVE ACROSS THE MIDWEST ON FRIDAY. THIS...COMBINED WITH
THE MID LEVEL BAROCLINIC ZONE COULD PRODUCE A DECENT LIGHT TO
MODERATE RAIN EVENT. HOWEVER...THE GFS STILL KEEPS THE UPPER LEVEL
RIDGE STRONG WITH NO RAIN IN SIGHT...SO CONFIDENCE IS NOT HIGH.
SO...KEPT FORECAST MAINLY DRY WITH NEAR NORMAL TEMPERATURES.
LE
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
619 PM MDT SUN JUL 29 2012
.SHORT TERM...(THIS EVENING THROUGH MONDAY AFTERNOON)
ISSUED AT 120 PM MDT SUN JUL 29 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE RIDGE CONTINUING TO
DOMINATE US PATTERN WITH CENTER OVER NORTHERN TEXAS. ALONG THE
WEST/NORTHWEST EXTENT OF THE RIDGE MONSOONAL MOISTURE CONTINUES TO
STREAM NORTH ACROSS THE INTER-MOUNTAIN WEST TOWARDS THE CWA. AT THE
SURFACE A LINGERING BAROCLINIC ZONE/DECAYED STATIONARY FRONT REMAINS
IN PLACE OVER THE CWA.
EARLY MORNING SHOWERS HAVE MOVED OFF TO THE EAST...WITH CLEARING
OCCURRING TO THE SOUTH AND WEST. MIXED LAYER CAPE VALUES ACROSS THE
AREA ARE CURRENTLY IN THE 500-1500 J/KG RANGE AND SHOULD INCREASE
WITH CLEARING AS LOW LEVEL LAPSE RATES STEEPEN. A WEAK SHORTWAVE
TROUGH IS PROGGED TO MOVE ACROSS SW NEBRASKA...AND MAY BE THE
FEATURE THAT HELPS GET THINGS GOING AGAIN TONIGHT. THE LATEST HRRR
WOULD INDICATE THAT THUNDERSTORM REDEVELOPMENT LIKELY WILL HOLD OFF
UNTIL AFTER 00Z...HOWEVER IT IS DEVELOPING WIDESPREAD CONVECTION
FURTHER SOUTH THAN WHAT THE LATEST NAM/GFS WOULD INDICATE...SO HAVE
KEPT POPS IN CHANCE CATEGORY THIS EVENING/OVERNIGHT. OVERALL SHEAR
IS WEAK AND THERE IS VERY LITTLE TO GET STORMS MOVING IN PROXIMITY
TO BAROCLINIC ZONE. WITH VERY HIGH PWAT VALUES IN EXCESS OF 1.5
HEAVY RAIN AND LOCALIZED FLOODING WILL BE POSSIBLE WITH THESE SLOW
MOVING THUNDERSTORMS. AS WITH YESTERDAY COVERAGE IS STILL A
QUESTION...WITH BEST COVERAGE RIGHT NOW EXPECTED TO BE ACROSS THE
NORTHERN HALF OTHER CWA OVERNIGHT IN PROXIMITY TO SHORTWAVE TROUGH.
WITH BAROCLINIC ZONE IN PLACE THROUGH MONDAY SHOWERS/THUNDERSTORMS
COULDN`T BE RULED OUT THROUGH MONDAY AFTERNOON AS WEAK PULSES
CONTINUE TO MOVE WITHIN PROXIMITY OF THE CWA.
TEMPERATURES SHOULD BE COOLER ON MONDAY AFTERNOON HIGHS IN THE MID
TO UPPER 90S ACROSS THE CWA. EASTERLY FLOW WILL DEVELOP ACROSS THE
REGION...AND H85 TEMPS WILL MODERATE SOME WITH VALUES ABOUT 3C COOLER.
DEPENDING ON CLOUD COVER SOME LOCATIONS COULD SEE HIGHS ON MONDAY
CLOSER TO NORMAL VALUES IN THE LOW 90S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 205 PM MDT SUN JUL 29 2012
RIDGE OVER THE SOUTHERN PLAINS WILL DRIFT WESTWARD. TEMPERATURES
WILL CONTINUE TO BE ABOVE NORMAL. THE RIDGE IS FAR ENOUGH SOUTH
THAT SHORTWAVE TROUGHS COMING OVER THE TOP WILL BRING OCCASIONAL
CHANCES FOR THUNDERSTORMS. MODELS HINTING AT FAIRLY STRONG ONE
TUESDAY NIGHT WITH POSSIBLE MCS DEVELOPING IN EASTERN COLORADO AND
MOVING ACROSS THE FORECAST AREA. BUMPED POPS UP TO
CHANCE...ESPECIALLY IN THE WEST. THE PATTERN BASICALLY REPEATS
THROUGH THE END OF THE WEEK...SO COULD END UP WITH A RATHER WET
PATTERN. STRONG SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS ON
FRIDAY AND DRIVE A COLD FRONT THROUGH THE AREA. COOLER
TEMPERATURES FOLLOW ON SATURDAY...AT LEAST CLOSER TO NORMAL.
DESPITE THE POST FRONTAL UPSLOPE AT THE SURFACE...SHORTWAVE
RIDGING IS FORECAST OVER THE WEEKEND...SO THINK PRECIPITATION
CHANCES WILL COME TO AN END.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 615 PM MDT SUN JUL 29 2012
PRIMARY AVIATION CONCERN IN THE NEAR TERM WILL BE THE POTENTIAL
FOR CONVECTION TO IMPACT BOTH TERMINALS. ONGOING CONVECTION OVER
SOUTHERN PORTIONS OF YUMA COUNTY AND CENTRAL PORTIONS OF KIT
CARSON COUNTY WILL CONTINUE TO TRANSLATE EASTWARD TOWARD KGLD. ANY
IMPACTS SHOULD BE REALIZED AFTER 02Z. DELAYED MENTION OF
CONVECTION FOR KMCK UNTIL 04Z BASED ON LATEST TRENDS. LARGE
COMPLEX OF CONVECTION CONTINUES TO ORGANIZE OVER FAR NORTHEASTERN
COLORADO WITH A GENERAL MOTION TO THE EAST-SOUTHEAST WITH TIME.
THIS WILL PROVIDE THE BEST OPPORTUNITY FOR CONVECTION AT KMCK
BETWEEN ROUGHLY 04Z AND 07Z. COULD SEE BRIEF PERIODS OF MVFR
VISBY/CIGS WITH STRONGEST STORMS OTHERWISE...EXPECTING VFR
CONDITIONS. WILL SEE ANOTHER OPPORTUNITY FOR CONVECTION LATE IN
THE EFFECTIVE PERIOD BUT TEMPORAL/SPATIAL UNCERTAINTY WILL
PRECLUDE INCLUSION FOR THIS TAF ISSUANCE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
224 PM MDT SAT JUL 28 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 224 PM MDT SAT JUL 28 2012
WV IMAGERY AND RUC H5 ANALYSIS SHOW STRONG RIDGE EXTENDING FROM THE
WESTERN US TO THE CENTRAL MISSISSIPPI RIVER VALLEY WITH A 597 HEIGHT
CENTER OVER NE OKLAHOMA. A PLUME OF MONSOONAL MOISTURE CONTINUES TO
ADVECT NORTH AND EAST ALONG THE WESTERN EXTENT OF THE RIDGE WITH
SEVERAL WEAK SHORTWAVE TROUGHS MOVING INTO THE TRI-STATE AREA FROM
THE WEST. AT THE SURFACE A COLD FRONT HAS STALLED OVER THE CWA AND
WILL ACT AS THE MAIN FOCUS FOR THUNDERSTORM DEVELOPMENT THROUGH THE
NEXT FEW DAYS.
EARLY THIS AFTERNOON ISOLATED THUNDERSTORMS HAVE ALREADY DEVELOPED
ACROSS THE NE CWA NEAR MCCOOK ALONG THE FRONT WITH CUMULUS FURTHER
SOUTH AND EAST. RUC SOUNDINGS CONTINUE TO SHOW INVERTED-V TYPE
SOUNDINGS ALONG WITH DCAPE VALUES AROUND 1400 J/KG OR GREATER ACROSS
THE EASTERN PART OF THE CWA...WHICH SUPPORTS A THREAT FOR STRONG
DAMAGING WINDS WITH ANY THUNDERSTORMS THAT DEVELOP. PWAT VALUES ARE
ACTUALLY PRETTY GOOD WITH VALUES AROUND 1.4-1.5 AS A RESULT OF
MONSOONAL MOISTURE ADVECTING INTO THE MID LEVELS...SO THUNDERSTORM
COULD BE GOOD RAIN PRODUCERS THOUGH STORM MOTIONS AROUND 20KT SHOULD
KEEP FLASH FLOOD THREAT LIMITED. STORM THUNDERSTORM ACTIVITY THIS
EVENING SHOULD BE TIED TO DIURNAL PROCESSES WITH ACTIVITY ENDING
SHORTLY AFTER SUNRISE.
SUNDAY...THERE WILL BE VERY LITTLE CHANGE IN THE PATTERN AS THE
STATIONARY FRONT LINGERS OVER THE CWA...AND THE RIDGE REMAINS IN
PLACE. THUNDERSTORMS SHOULD REDEVELOP BY THE AFTERNOON WITH THE
FRONT AGAIN ACTING AS THE MAIN FOCUS FOR INITIATION. NAM SOUNDINGS
SHOW EVEN BETTER MID LEVEL MOISTURE SUNDAY AFTERNOON WITH PWAT
VALUES IN EXCESS OF 1.6...WHICH IS ANOMALOUSLY HIGH FOR THIS TIME
OF YEAR. CONSIDERING THAT AND VERY LIGHT STORM MOTIONS ON SUNDAY
IN THE ABSENCE OF ANY FLOW ALONG THE STATIONARY FRONT...THERE WILL
BE AN INCREASED THREAT OF FLASH FLOODING WITH ANY THUNDERSTORMS
THAT DO DEVELOP. COVERAGE WILL BE A QUESTION...SO I AM NOT
CONFIDENT ENOUGH TO ISSUE A FLASH FLOOD WATCH FOR SUNDAY
AFTERNOON/EVENING DURING THIS FORECAST CYCLE...HOWEVER THIS SHOULD
BE WATCHED GOING FORWARD.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 112 PM MDT SAT JUL 28 2012
UPPER RIDGE OVER THE SOUTHERN PLAINS WILL DRIFT WEST SOUTHWESTWARD
DURING THIS PERIOD. FAST MOVING SHORTWAVE TROUGHS RIDING THE RIDGE
MIGHT BE CLOSE ENOUGH TO PROVIDE WEAK LIFT FOR ISOLATED AFTERNOON
AND EVENING THUNDERSTORMS...BUT CONFIDENCE IS LOW AND DO NOT
WARRANT MORE THAN A SLIGHT TO LOW CHANCE MENTION. TEMPERATURES
WILL CONTINUE TO BE ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1131 AM MDT SAT JUL 28 2012
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE PERIOD AT KGLD AND
KMCK. COLD FRONT JUST NW OF BOTH TERMINALS WILL DROP SOUTH OVER
THE NEXT FEW HOURS. THIS WILL ACT A FOCUS FOR ISOLATED TO
SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING WITHING THE
VICINITY OF BOTH TERMINALS. CONFIDENCE IS STILL TOO LOW TO INCLUDE
ANYTHING OTHER THAN VCTS. GUSTY SW WINDS BETWEEN 10 AND 20 KT
CURRENTLY OVER BOTH TERMINALS WILL BECOME LIGHT AND VARIABLE AS
FRONT SHIFTS SOUTH AND GRADIENT DECREASES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS JACKSON KY
137 PM EDT SAT JUL 28 2012
.UPDATE...
ISSUED AT 136 PM EDT SAT JUL 28 2012
UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS. VORT LOBE SWINGING
ACROSS OH IS TRIGGERING ISOLATED SHOWERS AS FAR SW AS THE
KY...WV...OH TRI STATE REGION. EXPECT THESE TO STAY NE OF FORECAST
AREA. ALSO APPEARS A FEW SHOWERS MAY BE TRYING TO DEVELOP OVER SW VA.
FOR NOW WILL CONTINUE TO CARRY A THE SLIGHT CHANCE OF PRECIPITATION
IN OUR FAR SOUTHEAST.
UPDATE ISSUED AT 1121 AM EDT SAT JUL 28 2012
LATEST SATELLITE IMAGERY INDICATES EXTENSIVE CU/SC FIELD WILL AFFECT
THE FORECAST AREA THIS AFTERNOON...WITH PARTLY CLOUDY SKIES. HAVE
UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 954 AM EDT SAT JUL 28 2012
OVERCAST LOW STRATUS ON SATELLITE IMAGERY THIS MORNING IN NORTHERN
PART OF FORECAST AREA AND IN SOUTHERN OH. BASED ON GOES CLOUD
THICKNESS PRODUCT THIS IS THINNING FAIRLY RAPIDLY. WAS AROUND 1200
FEET THICK AT 1215Z AND THINNING TO AROUND 600 FEET AT 1315Z. EXPECT
STRATUS TO CONTINUE TO THIN AND MIX OUT. ILN SOUNDING SHOWS FAIRLY
MOIST CONDITIONS UP TO 7OO MB AND AS LOW STRATUS MIXES OUT EXPECT CU
TO DEVELOP. HAVE MADE ADJUSTMENTS TO SKY COVER FORECAST TO ACCOUNT
FOR MORE CLOUD IN THE NORTH THIS MORNING...AND MORE CLOUD FOR THIS
AFTERNOON AS WELL AS CU FIELD DEVELOPS. SKY COVER HAS ALSO AFFECTED
THE DIURNAL TEMPERATURE RISE AND HAVE SLOWED THE RISE WHERE
CONDITIONS WILL BE MOSTLY CLOUDY THIS MORNING.
KEPT THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FAR
SOUTHEAST THIS AFTERNOON. THE 06Z GFS STILL SUPPORTS THIS
IDEA...WHILE THE 06Z NAM WOULD POINT TOWARDS DRY CONDITIONS.
INTERESTINGLY THE HRRR DEVELOPS SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS NEARLY THE ENTIRE FORECAST AREA THIS AFTERNOON. FEEL THIS IS
OVERDONE AND ONLY EXPECT A CU FIELD...NOT SCATTERED PRECIPITATION.
NDFD AND ZFP HAVE BEEN UPDATED.
UPDATE ISSUED AT 623 AM EDT SAT JUL 28 2012
FORECAST IS IN PRETTY GOOD SHAPE THIS MORNING WITH SKIES CONTINUING
TO CLEAR OFF. THERE IS SOME PATCHY MORNING FOG IN THE VALLEYS WHICH
WILL BE BURNING OFF SHORTLY AFTER SUNRISE. COLD FRONT IS CONTINUING
TO MAKE STEADY PROGRESS TO THE SOUTH AND EAST. LATEST 06Z NAM KEEPS
ALL THE CONVECTION SOUTHEAST OF THE AREA TODAY...BUT THE HRRR SHOWS
SOME HINTS AT SOME DEVELOPMENT IN THE SOUTHEAST AROUND MIDDAY.
THUS...GOING TO HANG ONTO THE SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR THE TIME BEING. IT IS POSSIBLE EVERYTHING ENDS UP
FURTHER SOUTHEAST AND THE AREA STAYS COMPLETELY DRY TODAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 308 AM EDT SAT JUL 28 2012
COLD FRONT IS QUICKLY DROPPING SOUTHEAST...VIRTUALLY ALIGNED WITH THE
OHIO RIVER PRESENTLY. COMPLEX OF SHOWERS AND STORMS CONTINUES TO ROLL
ACROSS AREAS NEAR THE TENNESSEE BORDER. BASED ON RADAR TRENDS...THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH AND EXIT OVER THE NEXT
HOUR...LEAVING BEHIND DRY CONDITIONS FOR THE REMAINDER OF THE
MORNING. COLD FRONT WILL ROCKET SOUTHEAST THIS MORNING...REACHING THE
VIRGINIA/KENTUCKY BORDER BY MID MORNING. WITH MOISTURE POOLING AHEAD
OF THE FRONT...A FEW SHOWERS OR STORMS COULD DEVELOP IN THE VICINITY
OF THE VIRGINIA BORDER BY MIDDAY INTO THE EARLY AFTERNOON. THIS
SHOULD ONLY IMPACT A SLIVER OF EASTERN KENTUCKY. THE REST OF THE AREA
WILL REMAIN DRY TODAY. THERE IS MARGINAL WIND SHEAR PRESENT...BUT
SEVERE THREAT WILL LIKELY BE CONFINED TO AREAS FURTHER SOUTHEAST OF
KENTUCKY.
HIGH PRESSURE WILL CONTINUE TO DEVELOP OVER THE REGION TODAY THROUGH
TONIGHT...KEEPING QUIET WEATHER AROUND THROUGH THE REMAINDER OF THE
WEEKEND.
A VERY PLEASANT WEEKEND IS ON TAP AS SLIGHTLY COOLER AND A LESS HUMID
AIRMASS SPREAD INTO EASTERN KENTUCKY HIGHS TODAY AND SUNDAY WILL TOP
OUT IN THE MID 80S WITH LOWS IN THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 AM EDT SAT JUL 28 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE GENERAL PATTERN ALOFT
THROUGH THE EXTENDED PORTION OF THE FORECAST. A SEMI-PERSISTENT TROUGH
WILL HOLD IN PLACE JUST TO THE NORTHEAST OF THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL PROMOTE OCCASIONAL SHORTWAVES TO DROP
INTO THE OHIO VALLY ON NORTHWEST FLOW. A KEY ONE LOOKS TO MOVE
THROUGH LATE MONDAY. TOWARD THE END OF THE UPCOMING WORK WEEK THE
MODELS START TO DEVIATE FROM EACH OTHER WITH THE LATEST ECMWF PUSHING
THE WESTERN RIDGE FURTHER EAST AND FLATTENING OUT THE PATTERN
LOCALLY WHEN COMPARED TO THE GFS. ACCORDINGLY...PREFER A BLENDED
SOLUTION WHEN THE MODELS ARE CLOSE...BUT LEAN MORE TOWARD THE ECMWF
WHEN THEY START TO DEVIATE. DID HONOR THE SHORTWAVE THAT THE NAM12
AND THE 00Z ECMWF BRING DOWN INTO THE AREA MONDAY NIGHT AS A
POTENTIAL MCS...OTHERWISE PREFER AN EVEN MIX OF THE GFS AND ECMWF
FOR WEATHER SPECIFICS THROUGH MIDWEEK...LEANING MORE TOWARD THE
LATTER BY THE END OF THE WEEK. ALSO INCLUDED A GENEROUS DIURNAL
CYCLE TO THE POP PATTERN AND MAGNITUDE...THOUGH...AS THE PAST SEVERAL
NIGHTS HAVE SHOWN...THE CONVECTION HAS BEEN ABLE TO THRIVE WELL PAST
PEAK HEATING...IN OUR AREA.
SENSIBLE WEATHER WILL FEATURE HIGH PRESSURE HOLDING ON FOR A MOSTLY
DRY DAY ON MONDAY BEFORE A WARM FRONT APPROACHES FROM THE WEST
POSSIBLY YIELDING SOME LATE DAY STORMS. THESE STORM CHANCES WILL
CONTINUE THROUGH THE NIGHT AS A SHOT OF MID LEVEL ENERGY LOOKS TO
DIVE THROUGH THE STATE AFTER DARK IN THE NAM12...WITH CONSIDERABLE
SUPPORT FROM THE LATEST ECMWF. OTHERWISE...WITH A WEAK PRESSURE
FIELD THROUGHOUT THE REGION...NORTHWEST FLOW ALOFT...AND A HUMID
ENVIRONMENT...EXPECT THE DIURNAL INSTABILITY CYCLE TO DRIVE THE
CONVECTIVE CHANCES INTO THE END OF THE WEEK WITH PERHAPS ANOTHER
BOUNDARY MOVING INTO THE CWA LATE IN THE PERIOD IN RESPONSE TO
CHANGES ALOFT. TEMPERATURES WILL BE SEASONABLY WARM THROUGH THE
EXTENDED WITH PLENTY OF HUMIDITY KEEPING THE LOWS FAIRLY HIGH AND
CONDITIONS MUGGY EACH NIGHT.
THE CR EXTENDED GRID PACKAGE CAME IN REASONABLE FOR THE PATTERN...
THOUGH DID MAKE ADJUSTMENTS TO THE DIURNAL/TEMPORAL PATTERN OF
MAXIMUM AND MINIMUM POPS THROUGH THE PERIOD. MADE ONLY MINOR TWEAKS
TO LOW TEMPERATURES EACH NIGHT AS THE TERRAIN EFFECTS WILL BE RATHER
LIMITED GIVEN THE STILL MOIST ENVIRONMENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 136 PM EDT SAT JUL 28 2012
EXTENSIVE AREA OF SCT TO BKN CU/SC IS ACROSS THE REGION. CLOUD BASES
NEAR THE 3K FOOT ABOVE GROUND LEVEL...WITH SOME LOCAL MVFR CEILINGS
PRESENT. CLOUD BASES WILL CONTINUE TO LIFT THIS AFTERNOON WITH VFR
CONDITIONS PREVAILING.
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT. CLOUDS WILL DECREASE
THIS EVENING...WITH MOSTLY CLEAR SKIES AND CALM WINDS SETTING THE
STAGE FOR FOG DEVELOPMENT TONIGHT. WITH THE EXCEPTION OF RIDGE TOP
AIRPORTS EXPECT IFR TO LIFR CONDITIONS TO DEVELOP. CONDITIONS WILL
IMPROVE AFTER SUNRISE ON SUNDAY...AND THERE SHOULD BE LESS EXTENSIVE
CU DEVELOPMENT LATE SUNDAY MORNING AND SUNDAY AFTERNOON. VFR
CONDITIONS WILL PREVAIL ONCE THE FOG DISSIPATES ON SUNDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM....GREIF
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1121 AM EDT SAT JUL 28 2012
.UPDATE...
ISSUED AT 1121 AM EDT SAT JUL 28 2012
LATEST SATELLITE IMAGERY INDICATES EXTENSIVE CU/SC FIELD WILL AFFECT
THE FORECAST AREA THIS AFTERNOON...WITH PARTLY CLOUDY SKIES. HAVE
UPDATED NDFD FOR LATEST OBSERVATIONAL TRENDS.
UPDATE ISSUED AT 954 AM EDT SAT JUL 28 2012
OVERCAST LOW STRATUS ON SATELLITE IMAGERY THIS MORNING IN NORTHERN
PART OF FORECAST AREA AND IN SOUTHERN OH. BASED ON GOES CLOUD
THICKNESS PRODUCT THIS IS THINNING FAIRLY RAPIDLY. WAS AROUND 1200
FEET THICK AT 1215Z AND THINNING TO AROUND 600 FEET AT 1315Z. EXPECT
STRATUS TO CONTINUE TO THIN AND MIX OUT. ILN SOUNDING SHOWS FAIRLY
MOIST CONDITIONS UP TO 7OO MB AND AS LOW STRATUS MIXES OUT EXPECT CU
TO DEVELOP. HAVE MADE ADJUSTMENTS TO SKY COVER FORECAST TO ACCOUNT
FOR MORE CLOUD IN THE NORTH THIS MORNING...AND MORE CLOUD FOR THIS
AFTERNOON AS WELL AS CU FIELD DEVELOPS. SKY COVER HAS ALSO AFFECTED
THE DIURNAL TEMPERATURE RISE AND HAVE SLOWED THE RISE WHERE
CONDITIONS WILL BE MOSTLY CLOUDY THIS MORNING.
KEPT THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FAR
SOUTHEAST THIS AFTERNOON. THE 06Z GFS STILL SUPPORTS THIS
IDEA...WHILE THE 06Z NAM WOULD POINT TOWARDS DRY CONDITIONS.
INTERESTINGLY THE HRRR DEVELOPS SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS NEARLY THE ENTIRE FORECAST AREA THIS AFTERNOON. FEEL THIS IS
OVERDONE AND ONLY EXPECT A CU FIELD...NOT SCATTERED PRECIPITATION.
NDFD AND ZFP HAVE BEEN UPDATED.
UPDATE ISSUED AT 623 AM EDT SAT JUL 28 2012
FORECAST IS IN PRETTY GOOD SHAPE THIS MORNING WITH SKIES CONTINUING
TO CLEAR OFF. THERE IS SOME PATCHY MORNING FOG IN THE VALLEYS WHICH
WILL BE BURNING OFF SHORTLY AFTER SUNRISE. COLD FRONT IS CONTINUING
TO MAKE STEADY PROGRESS TO THE SOUTH AND EAST. LATEST 06Z NAM KEEPS
ALL THE CONVECTION SOUTHEAST OF THE AREA TODAY...BUT THE HRRR SHOWS
SOME HINTS AT SOME DEVELOPMENT IN THE SOUTHEAST AROUND MIDDAY.
THUS...GOING TO HANG ONTO THE SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR THE TIME BEING. IT IS POSSIBLE EVERYTHING ENDS UP
FURTHER SOUTHEAST AND THE AREA STAYS COMPLETELY DRY TODAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 308 AM EDT SAT JUL 28 2012
COLD FRONT IS QUICKLY DROPPING SOUTHEAST...VIRTUALLY ALIGNED WITH THE
OHIO RIVER PRESENTLY. COMPLEX OF SHOWERS AND STORMS CONTINUES TO ROLL
ACROSS AREAS NEAR THE TENNESSEE BORDER. BASED ON RADAR TRENDS...THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH AND EXIT OVER THE NEXT
HOUR...LEAVING BEHIND DRY CONDITIONS FOR THE REMAINDER OF THE
MORNING. COLD FRONT WILL ROCKET SOUTHEAST THIS MORNING...REACHING THE
VIRGINIA/KENTUCKY BORDER BY MID MORNING. WITH MOISTURE POOLING AHEAD
OF THE FRONT...A FEW SHOWERS OR STORMS COULD DEVELOP IN THE VICINITY
OF THE VIRGINIA BORDER BY MIDDAY INTO THE EARLY AFTERNOON. THIS
SHOULD ONLY IMPACT A SLIVER OF EASTERN KENTUCKY. THE REST OF THE AREA
WILL REMAIN DRY TODAY. THERE IS MARGINAL WIND SHEAR PRESENT...BUT
SEVERE THREAT WILL LIKELY BE CONFINED TO AREAS FURTHER SOUTHEAST OF
KENTUCKY.
HIGH PRESSURE WILL CONTINUE TO DEVELOP OVER THE REGION TODAY THROUGH
TONIGHT...KEEPING QUIET WEATHER AROUND THROUGH THE REMAINDER OF THE
WEEKEND.
A VERY PLEASANT WEEKEND IS ON TAP AS SLIGHTLY COOLER AND A LESS HUMID
AIRMASS SPREAD INTO EASTERN KENTUCKY HIGHS TODAY AND SUNDAY WILL TOP
OUT IN THE MID 80S WITH LOWS IN THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 AM EDT SAT JUL 28 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE GENERAL PATTERN ALOFT
THROUGH THE EXTENDED PORTION OF THE FORECAST. A SEMI-PERSISTENT TROUGH
WILL HOLD IN PLACE JUST TO THE NORTHEAST OF THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL PROMOTE OCCASIONAL SHORTWAVES TO DROP
INTO THE OHIO VALLY ON NORTHWEST FLOW. A KEY ONE LOOKS TO MOVE
THROUGH LATE MONDAY. TOWARD THE END OF THE UPCOMING WORK WEEK THE
MODELS START TO DEVIATE FROM EACH OTHER WITH THE LATEST ECMWF PUSHING
THE WESTERN RIDGE FURTHER EAST AND FLATTENING OUT THE PATTERN
LOCALLY WHEN COMPARED TO THE GFS. ACCORDINGLY...PREFER A BLENDED
SOLUTION WHEN THE MODELS ARE CLOSE...BUT LEAN MORE TOWARD THE ECMWF
WHEN THEY START TO DEVIATE. DID HONOR THE SHORTWAVE THAT THE NAM12
AND THE 00Z ECMWF BRING DOWN INTO THE AREA MONDAY NIGHT AS A
POTENTIAL MCS...OTHERWISE PREFER AN EVEN MIX OF THE GFS AND ECMWF
FOR WEATHER SPECIFICS THROUGH MIDWEEK...LEANING MORE TOWARD THE
LATTER BY THE END OF THE WEEK. ALSO INCLUDED A GENEROUS DIURNAL
CYCLE TO THE POP PATTERN AND MAGNITUDE...THOUGH...AS THE PAST SEVERAL
NIGHTS HAVE SHOWN...THE CONVECTION HAS BEEN ABLE TO THRIVE WELL PAST
PEAK HEATING...IN OUR AREA.
SENSIBLE WEATHER WILL FEATURE HIGH PRESSURE HOLDING ON FOR A MOSTLY
DRY DAY ON MONDAY BEFORE A WARM FRONT APPROACHES FROM THE WEST
POSSIBLY YIELDING SOME LATE DAY STORMS. THESE STORM CHANCES WILL
CONTINUE THROUGH THE NIGHT AS A SHOT OF MID LEVEL ENERGY LOOKS TO
DIVE THROUGH THE STATE AFTER DARK IN THE NAM12...WITH CONSIDERABLE
SUPPORT FROM THE LATEST ECMWF. OTHERWISE...WITH A WEAK PRESSURE
FIELD THROUGHOUT THE REGION...NORTHWEST FLOW ALOFT...AND A HUMID
ENVIRONMENT...EXPECT THE DIURNAL INSTABILITY CYCLE TO DRIVE THE
CONVECTIVE CHANCES INTO THE END OF THE WEEK WITH PERHAPS ANOTHER
BOUNDARY MOVING INTO THE CWA LATE IN THE PERIOD IN RESPONSE TO
CHANGES ALOFT. TEMPERATURES WILL BE SEASONABLY WARM THROUGH THE
EXTENDED WITH PLENTY OF HUMIDITY KEEPING THE LOWS FAIRLY HIGH AND
CONDITIONS MUGGY EACH NIGHT.
THE CR EXTENDED GRID PACKAGE CAME IN REASONABLE FOR THE PATTERN...
THOUGH DID MAKE ADJUSTMENTS TO THE DIURNAL/TEMPORAL PATTERN OF
MAXIMUM AND MINIMUM POPS THROUGH THE PERIOD. MADE ONLY MINOR TWEAKS
TO LOW TEMPERATURES EACH NIGHT AS THE TERRAIN EFFECTS WILL BE RATHER
LIMITED GIVEN THE STILL MOIST ENVIRONMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM EDT SAT JUL 28 2012
AFTER SOME PATCHY MORNING VALLEY FOG...VFR CONDITIONS WILL TAKE HOLD
ACROSS THE AREA BY MID MORNING AND CONTINUING THROUGH THIS EVENING.
WE WILL LIKELY SEE MORE PATCHY VALLEY FOG TONIGHT AS CLEAR SKIES
DOMINATE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM....GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
954 AM EDT SAT JUL 28 2012
.UPDATE...
ISSUED AT 954 AM EDT SAT JUL 28 2012
OVERCAST LOW STRATUS ON SATELLITE IMAGERY THIS MORNING IN NORTHERN
PART OF FORECAST AREA AND IN SOUTHERN OH. BASED ON GOES CLOUD
THICKNESS PRODUCT THIS IS THINNING FAIRLY RAPIDLY. WAS AROUND 1200
FEET THICK AT 1215Z AND THINNING TO AROUND 600 FEET AT 1315Z. EXPECT
STRATUS TO CONTINUE TO THIN AND MIX OUT. ILN SOUNDING SHOWS FAIRLY
MOIST CONDITIONS UP TO 7OO MB AND AS LOW STRATUS MIXES OUT EXPECT CU
TO DEVELOP. HAVE MADE ADJUSTMENTS TO SKY COVER FORECAST TO ACCOUNT
FOR MORE CLOUD IN THE NORTH THIS MORNING...AND MORE CLOUD FOR THIS
AFTERNOON AS WELL AS CU FIELD DEVELOPS. SKY COVER HAS ALSO AFFECTED
THE DIURNAL TEMPERATURE RISE AND HAVE SLOWED THE RISE WHERE
CONDITIONS WILL BE MOSTLY CLOUDY THIS MORNING.
KEPT THE SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS IN THE FAR
SOUTHEAST THIS AFTERNOON. THE 06Z GFS STILL SUPPORTS THIS
IDEA...WHILE THE 06Z NAM WOULD POINT TOWARDS DRY CONDITIONS.
INTERESTINGLY THE HRRR DEVELOPS SCATTERED SHOWERS AND THUNDERSTORMS
ACROSS NEARLY THE ENTIRE FORECAST AREA THIS AFTERNOON. FEEL THIS IS
OVERDONE AND ONLY EXPECT A CU FIELD...NOT SCATTERED PRECIPITATION.
NDFD AND ZFP HAVE BEEN UPDATED.
UPDATE ISSUED AT 623 AM EDT SAT JUL 28 2012
FORECAST IS IN PRETTY GOOD SHAPE THIS MORNING WITH SKIES CONTINUING
TO CLEAR OFF. THERE IS SOME PATCHY MORNING FOG IN THE VALLEYS WHICH
WILL BE BURNING OFF SHORTLY AFTER SUNRISE. COLD FRONT IS CONTINUING
TO MAKE STEADY PROGRESS TO THE SOUTH AND EAST. LATEST 06Z NAM KEEPS
ALL THE CONVECTION SOUTHEAST OF THE AREA TODAY...BUT THE HRRR SHOWS
SOME HINTS AT SOME DEVELOPMENT IN THE SOUTHEAST AROUND MIDDAY.
THUS...GOING TO HANG ONTO THE SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR THE TIME BEING. IT IS POSSIBLE EVERYTHING ENDS UP
FURTHER SOUTHEAST AND THE AREA STAYS COMPLETELY DRY TODAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 308 AM EDT SAT JUL 28 2012
COLD FRONT IS QUICKLY DROPPING SOUTHEAST...VIRTUALLY ALIGNED WITH THE
OHIO RIVER PRESENTLY. COMPLEX OF SHOWERS AND STORMS CONTINUES TO ROLL
ACROSS AREAS NEAR THE TENNESSEE BORDER. BASED ON RADAR TRENDS...THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH AND EXIT OVER THE NEXT
HOUR...LEAVING BEHIND DRY CONDITIONS FOR THE REMAINDER OF THE
MORNING. COLD FRONT WILL ROCKET SOUTHEAST THIS MORNING...REACHING THE
VIRGINIA/KENTUCKY BORDER BY MID MORNING. WITH MOISTURE POOLING AHEAD
OF THE FRONT...A FEW SHOWERS OR STORMS COULD DEVELOP IN THE VICINITY
OF THE VIRGINIA BORDER BY MIDDAY INTO THE EARLY AFTERNOON. THIS
SHOULD ONLY IMPACT A SLIVER OF EASTERN KENTUCKY. THE REST OF THE AREA
WILL REMAIN DRY TODAY. THERE IS MARGINAL WIND SHEAR PRESENT...BUT
SEVERE THREAT WILL LIKELY BE CONFINED TO AREAS FURTHER SOUTHEAST OF
KENTUCKY.
HIGH PRESSURE WILL CONTINUE TO DEVELOP OVER THE REGION TODAY THROUGH
TONIGHT...KEEPING QUIET WEATHER AROUND THROUGH THE REMAINDER OF THE
WEEKEND.
A VERY PLEASANT WEEKEND IS ON TAP AS SLIGHTLY COOLER AND A LESS HUMID
AIRMASS SPREAD INTO EASTERN KENTUCKY HIGHS TODAY AND SUNDAY WILL TOP
OUT IN THE MID 80S WITH LOWS IN THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 AM EDT SAT JUL 28 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE GENERAL PATTERN ALOFT
THROUGH THE EXTENDED PORTION OF THE FORECAST. A SEMI-PERSISTENT TROUGH
WILL HOLD IN PLACE JUST TO THE NORTHEAST OF THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL PROMOTE OCCASIONAL SHORTWAVES TO DROP
INTO THE OHIO VALLY ON NORTHWEST FLOW. A KEY ONE LOOKS TO MOVE
THROUGH LATE MONDAY. TOWARD THE END OF THE UPCOMING WORK WEEK THE
MODELS START TO DEVIATE FROM EACH OTHER WITH THE LATEST ECMWF PUSHING
THE WESTERN RIDGE FURTHER EAST AND FLATTENING OUT THE PATTERN
LOCALLY WHEN COMPARED TO THE GFS. ACCORDINGLY...PREFER A BLENDED
SOLUTION WHEN THE MODELS ARE CLOSE...BUT LEAN MORE TOWARD THE ECMWF
WHEN THEY START TO DEVIATE. DID HONOR THE SHORTWAVE THAT THE NAM12
AND THE 00Z ECMWF BRING DOWN INTO THE AREA MONDAY NIGHT AS A
POTENTIAL MCS...OTHERWISE PREFER AN EVEN MIX OF THE GFS AND ECMWF
FOR WEATHER SPECIFICS THROUGH MIDWEEK...LEANING MORE TOWARD THE
LATTER BY THE END OF THE WEEK. ALSO INCLUDED A GENEROUS DIURNAL
CYCLE TO THE POP PATTERN AND MAGNITUDE...THOUGH...AS THE PAST SEVERAL
NIGHTS HAVE SHOWN...THE CONVECTION HAS BEEN ABLE TO THRIVE WELL PAST
PEAK HEATING...IN OUR AREA.
SENSIBLE WEATHER WILL FEATURE HIGH PRESSURE HOLDING ON FOR A MOSTLY
DRY DAY ON MONDAY BEFORE A WARM FRONT APPROACHES FROM THE WEST
POSSIBLY YIELDING SOME LATE DAY STORMS. THESE STORM CHANCES WILL
CONTINUE THROUGH THE NIGHT AS A SHOT OF MID LEVEL ENERGY LOOKS TO
DIVE THROUGH THE STATE AFTER DARK IN THE NAM12...WITH CONSIDERABLE
SUPPORT FROM THE LATEST ECMWF. OTHERWISE...WITH A WEAK PRESSURE
FIELD THROUGHOUT THE REGION...NORTHWEST FLOW ALOFT...AND A HUMID
ENVIRONMENT...EXPECT THE DIURNAL INSTABILITY CYCLE TO DRIVE THE
CONVECTIVE CHANCES INTO THE END OF THE WEEK WITH PERHAPS ANOTHER
BOUNDARY MOVING INTO THE CWA LATE IN THE PERIOD IN RESPONSE TO
CHANGES ALOFT. TEMPERATURES WILL BE SEASONABLY WARM THROUGH THE
EXTENDED WITH PLENTY OF HUMIDITY KEEPING THE LOWS FAIRLY HIGH AND
CONDITIONS MUGGY EACH NIGHT.
THE CR EXTENDED GRID PACKAGE CAME IN REASONABLE FOR THE PATTERN...
THOUGH DID MAKE ADJUSTMENTS TO THE DIURNAL/TEMPORAL PATTERN OF
MAXIMUM AND MINIMUM POPS THROUGH THE PERIOD. MADE ONLY MINOR TWEAKS
TO LOW TEMPERATURES EACH NIGHT AS THE TERRAIN EFFECTS WILL BE RATHER
LIMITED GIVEN THE STILL MOIST ENVIRONMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM EDT SAT JUL 28 2012
AFTER SOME PATCHY MORNING VALLEY FOG...VFR CONDITIONS WILL TAKE HOLD
ACROSS THE AREA BY MID MORNING AND CONTINUING THROUGH THIS EVENING.
WE WILL LIKELY SEE MORE PATCHY VALLEY FOG TONIGHT AS CLEAR SKIES
DOMINATE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...KAS
LONG TERM....GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
623 AM EDT SAT JUL 28 2012
.UPDATE...
ISSUED AT 623 AM EDT SAT JUL 28 2012
FORECAST IS IN PRETTY GOOD SHAPE THIS MORNING WITH SKIES CONTINUING
TO CLEAR OFF. THERE IS SOME PATCHY MORNING FOG IN THE VALLEYS WHICH
WILL BE BURNING OFF SHORTLY AFTER SUNRISE. COLD FRONT IS CONTINUING
TO MAKE STEADY PROGRESS TO THE SOUTH AND EAST. LATEST 06Z NAM KEEPS
ALL THE CONVECTION SOUTHEAST OF THE AREA TODAY...BUT THE HRRR SHOWS
SOME HINTS AT SOME DEVELOPMENT IN THE SOUTHEAST AROUND MIDDAY.
THUS...GOING TO HANG ONTO THE SMALL CHANCE FOR SHOWERS AND
THUNDERSTORMS FOR THE TIME BEING. IT IS POSSIBLE EVERYTHING ENDS UP
FURTHER SOUTHEAST AND THE AREA STAYS COMPLETELY DRY TODAY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 308 AM EDT SAT JUL 28 2012
COLD FRONT IS QUICKLY DROPPING SOUTHEAST...VIRTUALLY ALIGNED WITH THE
OHIO RIVER PRESENTLY. COMPLEX OF SHOWERS AND STORMS CONTINUES TO ROLL
ACROSS AREAS NEAR THE TENNESSEE BORDER. BASED ON RADAR TRENDS...THIS
ACTIVITY SHOULD CONTINUE TO DIMINISH AND EXIT OVER THE NEXT
HOUR...LEAVING BEHIND DRY CONDITIONS FOR THE REMAINDER OF THE
MORNING. COLD FRONT WILL ROCKET SOUTHEAST THIS MORNING...REACHING THE
VIRGINIA/KENTUCKY BORDER BY MID MORNING. WITH MOISTURE POOLING AHEAD
OF THE FRONT...A FEW SHOWERS OR STORMS COULD DEVELOP IN THE VICINITY
OF THE VIRGINIA BORDER BY MIDDAY INTO THE EARLY AFTERNOON. THIS
SHOULD ONLY IMPACT A SLIVER OF EASTERN KENTUCKY. THE REST OF THE AREA
WILL REMAIN DRY TODAY. THERE IS MARGINAL WIND SHEAR PRESENT...BUT
SEVERE THREAT WILL LIKELY BE CONFINED TO AREAS FURTHER SOUTHEAST OF
KENTUCKY.
HIGH PRESSURE WILL CONTINUE TO DEVELOP OVER THE REGION TODAY THROUGH
TONIGHT...KEEPING QUIET WEATHER AROUND THROUGH THE REMAINDER OF THE
WEEKEND.
A VERY PLEASANT WEEKEND IS ON TAP AS SLIGHTLY COOLER AND A LESS HUMID
AIRMASS SPREAD INTO EASTERN KENTUCKY HIGHS TODAY AND SUNDAY WILL TOP
OUT IN THE MID 80S WITH LOWS IN THE MID 60S.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 445 AM EDT SAT JUL 28 2012
THE MODELS ARE IN DECENT AGREEMENT WITH THE GENERAL PATTERN ALOFT
THROUGH THE EXTENDED PORTION OF THE FORECAST. A SEMI-PERSISTENT TROUGH
WILL HOLD IN PLACE JUST TO THE NORTHEAST OF THE REGION THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL PROMOTE OCCASIONAL SHORTWAVES TO DROP
INTO THE OHIO VALLY ON NORTHWEST FLOW. A KEY ONE LOOKS TO MOVE
THROUGH LATE MONDAY. TOWARD THE END OF THE UPCOMING WORK WEEK THE
MODELS START TO DEVIATE FROM EACH OTHER WITH THE LATEST ECMWF PUSHING
THE WESTERN RIDGE FURTHER EAST AND FLATTENING OUT THE PATTERN
LOCALLY WHEN COMPARED TO THE GFS. ACCORDINGLY...PREFER A BLENDED
SOLUTION WHEN THE MODELS ARE CLOSE...BUT LEAN MORE TOWARD THE ECMWF
WHEN THEY START TO DEVIATE. DID HONOR THE SHORTWAVE THAT THE NAM12
AND THE 00Z ECMWF BRING DOWN INTO THE AREA MONDAY NIGHT AS A
POTENTIAL MCS...OTHERWISE PREFER AN EVEN MIX OF THE GFS AND ECMWF
FOR WEATHER SPECIFICS THROUGH MIDWEEK...LEANING MORE TOWARD THE
LATTER BY THE END OF THE WEEK. ALSO INCLUDED A GENEROUS DIURNAL
CYCLE TO THE POP PATTERN AND MAGNITUDE...THOUGH...AS THE PAST SEVERAL
NIGHTS HAVE SHOWN...THE CONVECTION HAS BEEN ABLE TO THRIVE WELL PAST
PEAK HEATING...IN OUR AREA.
SENSIBLE WEATHER WILL FEATURE HIGH PRESSURE HOLDING ON FOR A MOSTLY
DRY DAY ON MONDAY BEFORE A WARM FRONT APPROACHES FROM THE WEST
POSSIBLY YIELDING SOME LATE DAY STORMS. THESE STORM CHANCES WILL
CONTINUE THROUGH THE NIGHT AS A SHOT OF MID LEVEL ENERGY LOOKS TO
DIVE THROUGH THE STATE AFTER DARK IN THE NAM12...WITH CONSIDERABLE
SUPPORT FROM THE LATEST ECMWF. OTHERWISE...WITH A WEAK PRESSURE
FIELD THROUGHOUT THE REGION...NORTHWEST FLOW ALOFT...AND A HUMID
ENVIRONMENT...EXPECT THE DIURNAL INSTABILITY CYCLE TO DRIVE THE
CONVECTIVE CHANCES INTO THE END OF THE WEEK WITH PERHAPS ANOTHER
BOUNDARY MOVING INTO THE CWA LATE IN THE PERIOD IN RESPONSE TO
CHANGES ALOFT. TEMPERATURES WILL BE SEASONABLY WARM THROUGH THE
EXTENDED WITH PLENTY OF HUMIDITY KEEPING THE LOWS FAIRLY HIGH AND
CONDITIONS MUGGY EACH NIGHT.
THE CR EXTENDED GRID PACKAGE CAME IN REASONABLE FOR THE PATTERN...
THOUGH DID MAKE ADJUSTMENTS TO THE DIURNAL/TEMPORAL PATTERN OF
MAXIMUM AND MINIMUM POPS THROUGH THE PERIOD. MADE ONLY MINOR TWEAKS
TO LOW TEMPERATURES EACH NIGHT AS THE TERRAIN EFFECTS WILL BE RATHER
LIMITED GIVEN THE STILL MOIST ENVIRONMENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 623 AM EDT SAT JUL 28 2012
AFTER SOME PATCHY MORNING VALLEY FOG...VFR CONDITIONS WILL TAKE HOLD
ACROSS THE AREA BY MID MORNING AND CONTINUING THROUGH THIS EVENING.
WE WILL LIKELY SEE MORE PATCHY VALLEY FOG TONIGHT AS CLEAR SKIES
DOMINATE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM....GREIF
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
124 AM EDT SAT JUL 28 2012
.AVIATION...
//DISCUSSION...
A LINGERING SURFACE TROUGH RESIDING WITHIN LOW LEVEL NORTHEAST FLOW
WILL MAINTAIN SOME POCKETS OF LOWER STRATUS THROUGH THE NIGHT.
LATEST SATELLITE TRENDS SUGGEST A PERIOD OF LOWER MVFR CONDITIONS
WILL EXIST FROM FNT DOWN THROUGH THE DETROIT CORRIDOR DURING THE
EARLY MORNING PERIOD. DRIER AIR WORKING IN FROM THE NORTH WILL HELP
MIX OUT THIS MOISTURE THROUGH THE LATTER HALF OF THE MORNING. HIGH
PRESSURE WILL THEN BRING A PERIOD OF MOSTLY CLEAR SKIES AND LIGHTER
NORTHEAST WINDS FOR THE LATTER HALF OF THE DAY.
//DTW THRESHOLD THREATS...
* NONE
&&
.PREV DISCUSSION...ISSUED 333 PM EDT FRI JUL 27 2012
SHORT TERM...THIS EVENING AND OVERNIGHT
CONVECTION HAS ERUPTED THIS AFTERNOON IN ADVANCE OF A MID LEVEL
SHORT WAVE IMPULSE NOW ROTATING INTO WRN LOWER MI. THE REGIONAL
WATER VAPOR LOOP INDICATES SMALLER SCALE CIRCULATIONS EMBEDDED
WITHIN THE SHORT WAVE...ONE NEAR MUSKEGON AND ONE OVER NW LOWER MI.
THE MID LEVEL WAVE WILL TRACK ACROSS SE MI THIS EVENING. DESPITE THE
EARLY ONSET OF CONVECTION...THE LARGER SCALE ASCENT ASSOCIATED WITH
THIS WAVE AND AMPLE LOW LEVEL MOISTURE WILL SUSTAIN CONVECTION INTO
AT LEAST EARLY EVENING. THUS FAR...SOME OF THE STRONGER STORMS HAVE
BEEN PRODUCING HAIL...INTENSE RAINFALL AND FREQUENT LIGHTNING. MID
LEVEL DRY AIR SHOWN ON THE WATER VAPOR LOOP SHOULD CONTINUE TO
SUPPORT SOME HAIL IN THE STRONGER CELLS. SLOW STORM MOVEMENT AND
PROLONGED LARGER SCALE FORCING WILL ALSO CONTINUE THE THREAT OF
LOCALIZED HEAVY RAINFALL. LENAWEE AND MONROE COUNTIES HAVE BEEN
PLACED IN A SEVERE THUNDERSTORM WATCH AS THEY ARE CLOSER TO THE
POOL OF BETTER INSTABILITY ACROSS THE OHIO VALLEY. STEEPER LOW
LEVEL LAPSE RATES AND STRONGER MID LEVEL WINDS NEAR THE OHIO
BORDER WILL ALSO PROVIDE AN OPPORTUNITY FOR STRONGER STORMS IN
THIS REGION. THE LATEST NAM AND RUC CONTINUE TO SUGGEST SOME
ENHANCEMENT IN MID TROPOSPHERIC DEFORMATION ALONG AND NORTH OF THE
I-69 CORRIDOR THROUGH EARLY EVENING AS THE CIRCULATION NEAR MKG
PUSHES EAST. THIS FORCING IS EXPECTED TO LINGER PAST 00Z BEFORE
SLOWLY WEAKENING AS IT MOVES EAST OF PORT HURON SHORTLY AFTER
MIDNIGHT...SUPPORTING DECREASING POPS THROUGH THE COURSE OF THE
NIGHT.
WEAK SFC LOW PRESSURE NOW LOCATED OVER NW OHIO WILL PUSH SOUTH
DURING THE NIGHT. SOME RESIDUAL SFC TROUGHING WILL LINGER OVER SE MI
INTO THE OVERNIGHT. THIS ALONG WITH NORTHEAST FLOW OFF LAKE HURON
AND THE DEVELOPMENT OF A WEAK SHALLOW INVERSION SHOULD ALLOW SOME
STRATUS REDEVELOPMENT TONIGHT. DRY AIR IS HOWEVER EXPECTED TO
IMPINGE ON THE SAGINAW VALLEY TOWARD DAYBREAK...WHICH MAY LEAD TO
SOME CLEARING NORTH OF FLINT LATE. THE POTENTIAL CLOUD COVER AND
INCREASING NERLY GRADIENT SHOULD HOLD MIN TEMPS MAINLY IN THE 60S
/WITH SOME 50S POSSIBLE IN THE TRI CITIES WHERE CLEARING IS POSSIBLE
PRIOR TO DAYBREAK/.
LONG TERM...SATURDAY THROUGH NEXT FRIDAY
SATURDAY BEGINS WITH THE EXIT OF THE MID-LEVEL WAVE AND SURFACE
PRESSURE TENDENCIES INCREASING ON THE ORDER OF 2-4 MB PER 6 HOURS.
LIFTED INDICES WILL BE WELL POSITIVE AND ANY LINGERING MOISTURE
CONTENT NEAR THE DETROIT RIVER WILL QUICKLY BE SCOURED OUT BY THE
APPROACHING HIGH PRESSURE. MORNING RH VALUES WILL BE HIGH ENOUGH TO
ALLOW FOR PATCHY AM FOG...OTHERWISE AN IDEAL SUMMER WEEKEND IS
EXPECTED. MAX TEMPERATURES WILL BE NEAR CLIMO NORMS AS A LOW
AMPLITUDE/LONGWAVE TROUGH SETTLES OVER THE REGION. BY SUNDAY NIGHT,
THE SURFACE HIGH WILL BE PUSHED EAST BY AN APPROACHING 100KT JET AND
SURFACE LOW.
THE GREAT LAKES REGION WILL REMAIN UNDER THE INFLUENCE OF A STABLE
NORTHWESTERLY FLOW CONFIGURATION ALOFT FOR MUCH OF NEXT WEEK. THE
NWP SOLUTION SPACE DOES DIVERGE SOMEWHAT TOWARD MIDWEEK...WITH THE
27.00 ECMWF BEING A BIT MORE AGGRESSIVE WITH RELEASING A PORTION OF
THE LONGWAVE RIDGE THROUGH THE UPPER MISSISSIPPI VALLEY INTO THE
WESTERN LAKES REGION. REGARDLESS OF THE SOLUTION VARIANCE...THE NET
RESULT WILL BE SEASONABLE CONDITIONS /NEAR TO SLIGHTLY ABOVE AVERAGE
TEMPERATURES/ WITH AN OCCASIONAL SHOT AT MEASURABLE PRECIPITATION.
CONSENSUS TIMING OF EMBEDDED SHORTWAVES WOULD SUGGEST THE BEST
CHANCES FOR RAINFALL WILL BE TUESDAY AND THURSDAY...BUT THAT WILL
CERTAINLY REQUIRE GREATER REFINEMENT GIVEN THE POOR RESOLUTION OF
THESE TRANSIENT FEATURES.
MARINE...
NORTHEASTERLY WINDS WILL INCREASE THIS EVENING AS LOW PRESSURE SINKS
SOUTH ACROSS THE OHIO VALLEY AND HIGH PRESSURE BUILDS OVER THE
NORTHERN GREAT LAKES. THIS ALONG WITH RECENT OBSERVATIONS OVER LAKE
HURON /ESPECIALLY SAGINAW BAY/ SUGGEST THESE WINDS ARE GOING TO KICK
UP SOME FAIRLY GOOD WAVE HEIGHTS THIS EVENING...PROMPTING THE
ISSUANCE OF SMALL CRAFT ADVISORIES FOR SAGINAW BAY AND THE NEARSHORE
WATERS FROM PORT AUSTIN DOWN TO PORT HURON. WINDS WILL RELAX ON
FRIDAY AS THE HIGH NUDGES INTO LOWER MI.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...NEARSHORE WATERS FROM PORT AUSTIN TO PORT
HURON INCLUDING SAGINAW BAY...UNTIL 6 AM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....MR
SHORT TERM...SC
LONG TERM....MM
MARINE.......SC
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GLASGOW MT
237 PM MDT SAT JUL 28 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH MONDAY...
WATER VAPOR IMAGERY AND 500 MB HEIGHT FIELD LOOK MUCH THE SAME AS
THEY DID AT THIS TIME YESTERDAY...BUT TODAY...THE STRENGTH AND
EXTENT OF THE UPPER LEVEL DOME OF HIGH PRESSURE OVER THE CENTRAL
HIGH PLAINS IS BEING CHALLENGED BY MULTIPLE EMBEDDED SMALLER SCALE SHORT
WAVE DISTURBANCES RIDING OVER THE TOP OF THE RIDGE.
FORECAST CHALLENGES WILL FOCUS ON HOW STRONG OR SEVERE THE
THUNDERSTORM THREAT IS TONIGHT. IT SEEMS THAT EVERY SHORT TERM
MODEL SOLUTION HAS A DIFFERENT IDEA ON WHAT IS GOING TO OR NOT
GOING TO HAPPEN. A FEW CLOUDS AND SOME SCATTERED STORMS CURRENTLY
GETTING STARTED OUT THERE OVER CENTRAL AND WESTERN MONTANA. SPC
OUTLOOK FOR THIS AFTERNOON AND EVENING PUTS A SLIGHT RISK AREA
OVER OUR SOUTH-CENTRAL AND SOUTH-WESTERN ZONES. THE GRID TIME FOR
NOW THROUGH 00Z SHOWS SIGNIFICANT MODEL QPF OUTPUT DISCREPANCIES.
GFS WANTS TO KEEP THE ENTIRE CWA DRY WHILE THE NAM WANTS TO BRING
IN AT LEAST A WETTING RAIN TO OUR SOUTH-WESTERN...NORTH-
WESTERN...AND FAR NORTH-EASTERN ZONES. THE HRRR WANTS TO PUSH
THROUGH A SCATTERED NORTH-TO-SOUTH ORIENTED LINE OF STORMS...BUT
EACH SUCCESSIVE MODEL RUN DELAYS THE ONSET OF STORMS AND BREAKS UP
THE LINE EVEN MORE. HARD TO KNOW WHICH MODEL TO TRUST AT THIS
TIME.
TONIGHT THROUGH SUNDAY...SHORT TERM MODELS SHOW BETTER AGREEMENT
AND KEEP SOME LINGERING PRECIPITATION NEAR THE SOUTHERN AND NORTH-
EASTERN PERIMETERS OF OUR CWA.
SUNDAY NIGHT THROUGH MONDAY...THE UPPER LEVEL RIDGE AXIS RE-
STRENGTHENS THROUGH MONTANA AND CUTS OF THE MOISTURE
FLOW...ALLOWING FOR HOT TEMPERATURES AND SUNNY SKIES TO DOMINATE
THROUGH THE FORECAST PERIOD. BMICKELSON
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...
GOOD MODEL CONSISTENCY IN THE SYNOPTIC PATTERN LEADS TO HIGH
CONFIDENCE THAT OUR AREA WILL REMAIN LARGELY UNDER THE INFLUENCE
OF AN UPPER LEVEL RIDGE CENTERED OVER THE SRN HI PLAINS THROUGH
WED NIGHT. THE TRICKY PART OF THE FORECAST IS TIMING OF WEAK
SHORTWAVES RIDING THROUGH THE RIDGE AXIS. THERE DOES SEEM TO BE
DECENT AGREEMENT AT LEAST AMONG A FEW OF THE MODELS THAT MON NIGHT
AND EARLY TUESDAY WILL BE UNSETTLED AS CONVECTION INITIATES ALONG
A SURFACE BOUNDARY ACROSS NORTHEAST MT AND MOVES EAST. SO HAVE
RELATIVELY HIGHER POPS IN THE CHANCE CATEGORY FOR THAT PERIOD.
TEMPERATURES WILL REMAIN WARMER THAN NORMAL THROUGH THE MIDDLE OF
THE WEEK.
BY LATE WEDNESDAY INTO THURSDAY AN UPPER LEVEL TROUGH MOVING
ONSHORE OVER BRITISH COLUMBIA WILL TRACK EASTWARD AND SUPPRESS THE
RIDGE AXIS...USHERING COOLER...NEAR TO BELOW NORMAL...AIR SOUTH
INTO MT BY THE END OF THE WEEK. RAIN CHANCES WILL DEPEND ON HOW
FAR SOUTH THE ENERGY WITH THIS SHORTWAVE ACTUALLY TRACKS. FOR
NOW...LEFT POPS IN THE SLIGHT CHANCE OR LESS CATEGORY. MOYER
&&
.AVIATION...
28/18Z...VFR CONDITIONS EXPECTED FOR THE MOST PART. ISOLATED TO
SCATTERED TSTMS ARE EXPECTED TO DEVELOP OR MOVE ACROSS NORTHEAST
MONTANA LATE THIS AFTN THROUGH MIDNIGHT. SYNOPTIC FEATURES AND
MESOSCALE MODELS SUPPORT THIS SCENARIO. FEEL PRETTY CONFIDENT ABOUT TIMING
AT TAF SITES...BUT LESS CONFIDENT ABOUT WHETHER ANY GIVEN TAF SITE
WILL EXPERIENCE A TSTM. SO AM JUST GOING TO CARRY A CB MENTION FOR
A TWO-HOUR WINDOW. MOYER
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
412 PM CDT SAT JUL 28 2012
.SHORT TERM...THROUGH LATE SUNDAY AFTERNOON. THE MOST IMPORTANT
ISSUE OVER THE NEXT 24 HOURS IS MONITORING FOR STRONG TO SEVERE
CONVECTION MAINLY THROUGH MIDNIGHT TONIGHT...WITH SECONDARY
CONCERNS CONSISTING OF NEAR HEAT ADVISORY CONDITIONS MAINLY IN
NORTH CENTRAL KS ZONES SUNDAY AFTERNOON...AND ALSO VERY-NEAR
CRITICAL FIRE WEATHER CONDITIONS THROUGH EARLY THIS EVENING IN
SOUTHWEST ZONES.
19Z OBJECTIVE SURFACE ANALYSIS INDICATES WHAT ESSENTIALLY AMOUNTS
TO A TRIPLE POINT ACROSS SOUTHWEST PORTIONS OF THE CWA...AS A
WELL-DEFINED NORTHWEST-SOUTHEAST ORIENTED WARM FRONT CONTINUES
SURGING NORTHEAST INTO THE CWA...WHILE A WEAK SURFACE TROUGH
EXTENDS FROM THE FURNAS COUNTY AREA NORTHWARD INTO NORTH CENTRAL
NEB. AS EXPECTED...TEMPERATURES HAVE SOARED IN THE SOUTHWESTERLY
FLOW IN THE WAKE OF THE WARM FRONT...WITH A SEASONABLY IMPRESSIVE
MID AFTERNOON TEMPERATURE GRADIENT RANGING FROM THE UPPER 80S-LOW
90S IN NORTH/NORTHEAST ZONES...TO 102-108 IN SEVERAL SOUTHWEST
COUNTIES. WIND DIRECTION IS ALSO SHOWING A RATHER SHARP VARIANCE
ACROSS THE WARM FRONT...TRANSITIONING FROM SOUTHEASTERLY TO
SOUTHWESTERLY AS THE WARM FRONT PASSES...ALONG WITH A NOTICEABLE
DECREASE IN DEWPOINTS. VISIBLE SATELLITE IMAGERY IS SHOWING QUITE
A BIT OF MID LEVEL CLOUD COVER INCREASING OVER THE CWA FROM THE
NORTHWEST...WHILE ALONG THE ADVANCING WARM FRONT AND TRIPLE POINT
AREA...THUS FAR WEAK ISOLATED/SCATTERED SHOWERS/STORMS ARE
DEVELOPING ON THE LEADING EDGE OF A SCATTERED CUMULUS
FIELD...WITH THE BOUNDARY LAYER CUMULUS AREA CLOSELY TIED TO THE
EDGE OF A NORTHEASTWARD ADVANCING PLUME OF STEEP LOW LEVEL LAPSE
RATES. WATER VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEALS THE
CENTER OF THE PRIMARY MID-UPPER RIDGE OVER THE SOUTHERN
PLAINS...WITH THE CWA AND CENTRAL/NORTHERN PLAINS REGION
UNDERNEATH THE SEASONABLY RESPECTABLE WEST-NORTHWEST FLOW ALOFT
ALONG THE PERIPHERY OF THE RIDGE...WITH THE ONLY DISCERNIBLE
SHORTWAVE ON WATER VAPOR IMAGERY ACROSS SD.
STARTING OFF WITH FIRE WEATHER THE NEXT FEW HOURS...IN HINDSIGHT
PROBABLY COULD HAVE/SHOULD HAVE ISSUED A FIRE WEATHER HEADLINE FOR A
HANDFUL OF SOUTHWESTERN COUNTIES AS RELATIVE HUMIDITY VALUES HAVE
CRASHED TO NEAR OR JUST BELOW 20 PERCENT BEHIND THE SURGING WARM
FRONT AND WIND GUSTS HAVE FAIRLY CONSISTENTLY REACHED/TOPPED 25
MPH. HOWEVER...BEING PAST MID AFTERNOON ALREADY...WILL FOREGO
WARNING ISSUANCE AND KEEP ELEVATED FIRE DANGER MENTION IN THE HWO
AND EXTREME FIRE DANGER CATEGORY IN THE GRASSLAND FIRE DANGER
PRODUCT.
TURNING TO THUNDERSTORM CHANCES/SEVERITY...PLENTY OF QUESTIONS
STILL REMAIN REGARDING COVERAGE AND SEVERITY. FOR ONE THING...THE
FAIRLY EXPANSIVE BAND OF MID CLOUDS OVERTAKING MUCH OF THE CWA IS
LIKELY NOT DOING ANY FAVORS FOR HELPING THE CURRENTLY WEAK
CONVECTION MAINLY IN SOUTHWEST ZONES OVERCOME AT LEAST A WEAK
CAPPING INVERSION...WHILE AT THE SAME TIME...HOURLY MESOSCALE
ANALYSIS INDICATES A FAVORABLE ENVIRONMENT FOR SEVERE WITH
1000-2000 J/KG MLCAPE...AND AT LEAST 30KT OF 0-6KM DEEP LAYER
SHEAR...WHICH IS ENOUGH TO GET AT LEAST BRIEF SUPERCELL STRUCTURES
GOING. LEANING ON HIGHER RES MODELS SUCH AS THE HRRR AND 00Z 4K
WRF-NMM...ANTICIPATE STORMS TO GRADUALLY INCREASE IN COVERAGE AND
INTENSITY AS THE LATE AFTERNOON/EVENING WEARS ON...ESPECIALLY
ACROSS THE SOUTHERN 2/3 OF THE CWA. HOWEVER...GIVEN CONTINUED
UNCERTAINTY IN ULTIMATE COVERAGE AND DESIRE TO NOT GET RAIN HOPES UP
TOO MUCH IN THIS DROUGHT PATTERN...HAVE OPTED TO LIMIT POPS TO NO
MORE THAN 30 PERCENT/SCATTERED COVERAGE FOR NOW THROUGH 06Z. ANY
STRONG/SEVERE STORMS THAT GET GOING SHOULD PRIMARILY POSE A WIND
THREAT...GIVEN STEEP LOW LEVEL LAPSE RATES AND CONSIDERABLE
SURFACE TEMP-DEWPOINT DEPRESSIONS AND RESULTANT HIGH CLOUD BASES.
HOWEVER...HAIL TO AROUND QUARTER SIZE CANNOT BE RULED OUT
COMPLETELY. ALTHOUGH SPC HAS OFFICIALLY LEFT THE SOUTHWEST 1/3 OR
SO OF THE CWA OUT OF A SLIGHT RISK...FOR LOCAL PRODUCT PURPOSES
FEEL THAT INCLUDING ALL 30 COUNTIES IN A SLIGHT RISK SCENARIO FOR
WIND/HAIL IS THE WAY TO GO. WOULD EXPECT INDIVIDUAL/MULTICELL
UPDRAFTS TO POSSIBLY CONGEAL INTO A BROKEN SOUTH-SOUTHEAST MOVING
LINE AT SOME POINT THIS EVENING ACROSS THE SOUTHERN CWA...POSSIBLY
ENHANCING A LOCALIZED WIND THREAT. AFTER 06Z...INTRODUCED A 20 POP
ACROSS A FEW FAR SOUTHEASTERN COUNTIES TO ACCOUNT FOR THE
POSSIBILITY OF LINGERING OVERNIGHT STORMS ALONG A VEERING LOW
LEVEL JET AXIS...BUT BY THIS TIME ANTICIPATE ANY SEVERE THREAT TO
BE ON THE WANE. TEMP WISE TONIGHT...NUDGED DOWN LOWS A FEW DEGREES
MOST AREAS PER GUIDANCE CONSENSUS...RANGING FROM LOW 60S FAR
NORTHWEST TO AROUND 70 FAR SOUTHEAST.
GETTING INTO THE DAYTIME HOURS TOMORROW...AND STARTING WITH
TEMPERATURES...AM WONDERING JUST HOW WARM IT IS GOING TO GET WITH
NORTHEAST/EASTERLY BREEZES FLOWING INTO THE CWA IN THE FORM A WEAK
BACK DOOR COLD FRONT FLOWING OUT OF A SURFACE HIGH TO THE
NORTHEAST. HOWEVER...WITH 850MB TEMPERATURES STAYING QUITE
TOASTY...IT WON/T TAKE MUCH MIXING TO GET THINGS CLIMBING FAST. AS
A RESULT...ONLY NUDGED DOWN HIGHS AN AVERAGE OF 1-2 DEGREES MOST
AREAS...STILL CALLING FOR MID-UPPER 90S IN MOST NEB ZONES...AND
100-105 IN KS ZONES AND FURNAS COUNTY AREA. ALTHOUGH CONFIDENCE IS
LOW REGARDING DEWPOINT TRENDS...WITH THE NAM SOMEWHAT INEXPLICABLY
CRASHING DEWPOINTS ALL THE WAY INTO THE UPPER 30S IN NORTHERN
AREAS ALTHOUGH THIS SOLUTION WAS NOT FOLLOWED...CURRENT GRIDS
YIELD HEAT INDEX VALUES IN THE 103-105 RANGE ACROSS PARTS OF KS
ZONES...WHICH COULD NECESSITATE HEAT ADVISORY ISSUANCE.
HOWEVER...WITH SOME UNCERTAINTY REMAINING REGARDING THE STRENGTH
OF THE BACK DOOR COLD FRONT ALONG WITH DEWPOINTS...WILL DEFER TO
OVERNIGHT SHIFT FOR POSSIBLE ADVISORY ISSUANCE...AND CONTINUE TO
MENTION HEAT IN THE HAZARDOUS WEATHER OUTLOOK. AS FOR STORM
CHANCES...LEFT THE MORNING HOURS FREE OF RAIN MENTION...ALTHOUGH
SOME ACTIVITY COULD BE FESTERING RATHER CLOSE TO THE FAR SOUTHERN
EDGE OF THE CWA. FOR THE AFTERNOON HOURS...TRIMMED BACK THE AREA
OF SLIGHT POPS TO ONLY AREAS MAINLY SOUTH OF A CAMBRIDGE-SMITH
CENTER LINE...WHERE THE PRIMARY SURFACE FRONT WILL STALL OUT AND
FOCUS A POSSIBLE INSTABILITY AXIS. AT THIS TIME...NOT ANTICIPATING
A SEVERE THREAT DURING THE DAYTIME PERIOD...BUT IN THIS TRICKY
PATTERN WITH ONE SUBTLE SHORTWAVE AFTER ANOTHER MOVING ACROSS THE
TOP OF THE UPPER RIDGE AXIS...THINGS ARE SUBJECT TO CHANGE ON
SOMEWHAT SHORT NOTICE.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. BIGGEST CHALLENGE WILL
BE DETERMINING CHANCES AND TIMING OF ANY PRECIPITATION. ENSEMBLE
MEANS FROM THE ECMWF SEEM THE BEST BET FOR CONSISTENCY. WE BEGIN
THE LONG TERM WITH THE SOUTH CENTRAL PLAINS ANTICYCLONE HEAVILY
INFLUENCING OUR WEATHER...BUT WITH NUMEROUS SHALLOW PERTURBATIONS
ALONG THE PERIPHERY TO THROW UNCERTAINTY INTO THE FORECAST.
UNCERTAINTY ALSO EXISTS FOR WHAT KIND OF SURFACE FEATURES WE MIGHT
HAVE...BUT WE COULD HAVE A FRONT DRAPED ACROSS THE CWA SUNDAY
NIGHT...AS SUGGESTED BY SOME MODELS...THAT COULD BE A FOCUS FOR
ELEVATED CONVECTION...MAINLY ALONG AND JUST NORTH OF THE BOUNDARY.
AN EAST-WEST ORIENTED THETA-E RIDGE IS ADVERTISED TO DRAPE ACROSS
SOUTH CENTRAL NEBRASKA FOR SUNDAY NIGHT...WHICH SUGGESTS THAT
CHANCES OF PRECIPITATION IN THE FORECAST ARE WARRANTED. THERE
COULD BE BOUNDARIES DRAPED ACROSS PARTS OF THE CWA FOR THE BULK OF
THE LONG TERM AS WELL...AS THE FORECAST GETS A LITTLE MUDDLED WITH
POTENTIALLY COMPLICATED SURFACES FEATURES.
THE ANTICYCLONE/RIDGE WILL RETROGRADE SOMEWHAT BY MONDAY...WITH
PERTURBATIONS CONTINUING TO PLAY HAVOC ON ANY CERTAINTY IN THE
FORECAST. THE UPPER LEVEL HIGH WILL CONTINUE TO BE A PROMINENT
FEATURE FOR THE REMAINDER OF THE LONG TERM...HOWEVER. MODELS ARE
KEEPING POTENTIALLY SIGNIFICANT AMOUNTS OF MID-HIGH LEVEL CLOUDINESS
AROUND ON TUESDAY...AND I WILL KNOCK DOWN TEMPERATURES A BIT FROM
THE PREVIOUS FORECAST FOR THIS REASON. WITH THE UPPER LEVEL HIGH IN
PLACE FOR THE REST OF THE WEEK...THIS MEANS MORE ABOVE NORMAL
TEMPERATURES...EVEN WITH ADDITIONAL MID TO UPPER LEVEL CLOUDINESS.
SINCE THE HIGH RETROGRADES A BIT...THIS SHOULD ALLOW A BIT MORE
CHANCES OF PRECIPITATION MORE OFTEN WITH FREQUENT PERTURBATIONS
POSSIBLE. THE ECMWF INDICATES A BIT MORE SIZABLE OF A SHORTWAVE
TROUGH CUTTING THROUGH THE NORTHERN/CENTRAL PLAINS FOR
SATURDAY...WHICH WILL HELP FLATTEN THE RIDGE SOMEWHAT...AND PERHAPS
GIVE A BETTER SHOT AT PRECIPITATION THAN THE LOW CONFIDENCE/LOW
CHANCE PRECIPITATION PATTERN FOR MUCH OF THE LONG TERM. JUDGING BY
THE POTENTIAL STRENGTH OF THE WAVE...THIS COULD BE THE MOST
POTENTIAL FOR SEVERE WEATHER IN THE LONG TERM AS WELL...NOT TO SAY
THERE COULD NOT BE A STRONG STORM WITH ANY CONVECTION THAT MAY FIRE
ALONG THE WAY DURING THE EXTENDED. ALTHOUGH...THE 12Z ECMWF HAS JUST
BACKED OFF OF THE AMPLITUDE OF THE WAVE ON SATURDAY...THIS WAVE
STILL BEARS WATCHING FOR POTENTIAL PRECIPITATION AND PERHAPS STRONG
TO SEVERE WEATHER.
&&
.PREV DISCUSSION... /ISSUED 1202 PM CDT SAT JUL 28 2012/
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY REMAINS IN THE
FORECAST FOR THE NEXT 24 HOURS...WITH MID LEVEL CLOUDS UNLIKELY TO
DROP BELOW 8000 FT EXCEPT POSSIBLY IN HIT OR MISS THUNDERSTORM
ACTIVITY. SPEAKING OF THIS THUNDERSTORM POSSIBILITY...CONFIDENCE
STILL REMAINS ON THE LOW SIDE WHETHER THE TERMINAL WILL BE
DIRECTLY IMPACTED...BUT JUST TO HINT AT THE POSSIBILITY OPTED TO
INTRODUCE A VICINITY THUNDERSTORM /VCTS/ MENTION COVERING A 5-HOUR
PERIOD FROM MID AFTERNOON INTO THIS EVENING. ALTHOUGH NOT
REFLECTED IN THE CURRENT TAF...ANY STORMS NEAR KGRI COULD INDUCE
SOME GUSTY/ERRATIC WINDS. OUTSIDE OF ANY STORMS...SURFACE WINDS
WILL PREVAIL FROM THE SOUTH THIS AFTERNOON...WITH GUST POTENTIAL
TO AROUND 21KT. OVERNIGHT...ANTICIPATE MORE OF A VARIABLE 6KT WIND
REGIME...WITH SOME LIGHT HAZE NOT OUT OF THE QUESTION...POSSIBLY
INDUCING VISIBILITY RESTRICTIONS DOWN TO AROUND 6SM BUT ABOVE MVFR
THRESHOLDS. AFTER SUNRISE SUNDAY MORNING...BREEZES WILL PICK UP
SLIGHTLY TO AROUND 11KT FROM THE NORTH-NORTHEAST BEHIND A WEAK
COLD FRONT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...HEINLEIN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1202 PM CDT SAT JUL 28 2012
.UPDATE...PRIMARY CHALLENGE FOR THIS AFTERNOON/EVENING CONTINUES
TO BE HOW MUCH THUNDERSTORM ACTIVITY WILL DEVELOP...FOLLOWED BY
HOW CLOSE PARTS OF THE SOUTHWEST CWA WILL GET TO REACHING CRITICAL
FIRE WEATHER THRESHOLDS. IN SHORT...HAVE CHANGED VERY LITTLE OF
NOTE FROM THE PREVIOUS FORECAST...OTHER THAN DELAYING ANY RISK OF
CONVECTION TO AFTER 20Z INSTEAD OF THE PREVIOUSLY ADVERTISED 18Z.
STILL KEPT POPS AT NO MORE THAN 30 PERCENT FOR THIS EVENT GIVEN
UNCERTAINTY IN COVERAGE...AT LEAST FOR NOW. DETERMINISTIC AND HIGH
RES QPF FIELDS HAVE BEEN ALL OVER THE PLACE THIS MORNING...BUT
WITH THE HRRR FINALLY ACKNOWLEDGING THAT MOST ACTIVITY SHOULD HOLD
OFF UNTIL THE MID- LATE AFTERNOON HOURS VERSUS EARLY AFTERNOON. AT
THE SURFACE...THE PRIMARY INITIAL FOCUS FOR AFTERNOON/EVENING
CONVECTION LOOKS TO BE A SURFACE TROUGH CURRENTLY SETTING UP ALONG
A LINE FROM NORTH CENTRAL TO SOUTHWEST NEB. ALTHOUGH WATER VAPOR
IMAGERY INDICATES NO WELL-DEFINED DISTURBANCES HEADING OUR
WAY...SUBTLE SHORTWAVE ENERGY EMBEDDED IN THE NEARLY ZONAL FLOW
SHOULD BE ENOUGH TO KICK OFF STORMS...ESPECIALLY AS AT LEAST
1000-1500 J/KG 0-1KM MLCAPE WEAKENS THE CAP IN THE VICINITY OF THE
SURFACE TROUGH. GIVEN FAIRLY WELL-MIXED BOUNDARY LAYER ANTICIPATE
INITIAL STORMS ACROSS THE NORTHERN/WESTERN CWA TO STEADILY
PROPAGATE EAST- SOUTHEAST...AND POSSIBLY TAKE ON A QUASI-LINEAR
CONFIGURATION. ALTHOUGH INSTABILITY IS NOT LOOKING OVERLY
HIGH...AT LEAST BRIEF GENERALLY HIGH BASED SUPERCELL STRUCTURES
CANNOT BE RULED OUT GIVEN 30-40KT OF DEEP LAYER SHEAR. EARLIER
THIS MORNING SPC UPGRADED MUCH OF THE NORTHERN 1/2 OF THE CWA TO A
SLIGHT RISK...AND FROM A LOCAL FORECAST PERSPECTIVE...FEEL THAT AT
LEAST A BRIEF SEVERE WEATHER THREAT PROBABLY CANNOT BE RULED OUT
ANYWHERE WITHIN THE CWA THROUGH THIS EVENING. REGARDING OTHER
ELEMENTS OF TODAYS FORECAST...MADE VERY LITTLE CHANGE TO HIGH TEMP
FORECAST...BUT DID LOWER SOME NORTHEAST COUNTIES A FEW DEGREES
GETTING THEM MORE SO INTO THE 92-94 RANGE. OTHERWISE...UPPER 90S
TO AROUND 105 STILL APPEAR ON TRACK IN KS ZONES...AND AS MENTIONED
BY OVERNIGHT SHIFT...IT COULD BE A VERY CLOSE CALL WHETHER SOME
SOUTHWESTERN COUNTIES MEET CRITICAL FIRE WEATHER CRITERIA THIS
AFTERNOON. WILL CONTINUE TO MONITOR BUT NO FIRE WEATHER HEADLINES
PLANNED AT THIS TIME.
&&
.AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY REMAINS IN THE
FORECAST FOR THE NEXT 24 HOURS...WITH MID LEVEL CLOUDS UNLIKELY TO
DROP BELOW 8000 FT EXCEPT POSSIBLY IN HIT OR MISS THUNDERSTORM
ACTIVITY. SPEAKING OF THIS THUNDERSTORM POSSIBILITY...CONFIDENCE
STILL REMAINS ON THE LOW SIDE WHETHER THE TERMINAL WILL BE
DIRECTLY IMPACTED...BUT JUST TO HINT AT THE POSSIBILITY OPTED TO
INTRODUCE A VICINITY THUNDERSTORM /VCTS/ MENTION COVERING A 5-HOUR
PERIOD FROM MID AFTERNOON INTO THIS EVENING. ALTHOUGH NOT
REFLECTED IN THE CURRENT TAF...ANY STORMS NEAR KGRI COULD INDUCE
SOME GUSTY/ERRATIC WINDS. OUTSIDE OF ANY STORMS...SURFACE WINDS
WILL PREVAIL FROM THE SOUTH THIS AFTERNOON...WITH GUST POTENTIAL
TO AROUND 21KT. OVERNIGHT...ANTICIPATE MORE OF A VARIABLE 6KT WIND
REGIME...WITH SOME LIGHT HAZE NOT OUT OF THE QUESTION...POSSIBLY
INDUCING VISIBILITY RESTRICTIONS DOWN TO AROUND 6SM BUT ABOVE MVFR
THRESHOLDS. AFTER SUNRISE SUNDAY MORNING...BREEZES WILL PICK UP
SLIGHTLY TO AROUND 11KT FROM THE NORTH-NORTHEAST BEHIND A WEAK
COLD FRONT.
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT SAT JUL 28 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MULTIPLE FORECAST
CONCERNS...ESP TODAY AND SUNDAY...INCLUDING
TEMPERATURES...PRECIP CHANCES...AND FIRE WEATHER ISSUES.
SATELLITE AND UPPER LEVEL PROFILER DATA CONTINUE TO SHOW THE
REGION UNDER THE INFLUENCE OF HIGH PRESSURE/RIDGING CENTERED
OVER THE SRN PLAINS...WHILE A WEAK DISTURBANCE CONTINUES TO RIDE
AROUND THE EDGE OF THE RIDGE...CURRENTLY OVER NERN NEB/SERN SD.
ANOTHER DISTURBANCE IS CURRENTLY MAKING ITS WAY THROUGH WY...WHICH
CAN ALSO BE PICKED OUT VIA LIGHTNING DATA. WAS CONCERNED LAST
NIGHT THAT THE ACTIVITY MAY STAY JUST NORTH OF THE CWA...AND AT
THIS POINT...LOOKS LIKE HOW IT IS GOING TO TURN OUT. AT THE
SURFACE...THE CWA SITS BETWEEN HIGH PRESSURE EXTENDING FROM NRN IA
INTO ERN CANADA...AND LOW PRESSURE DRAPED ALONG THE HIGH/SRN
PLAINS...BRINGING SOUTHEASTERLY FLOW...WITH SPEEDS GENERALLY
NEAR/LESS THAN 10 MPH.
LOOKING TO THE REST OF TODAY AND INTO TONIGHT...CONTINUE TO SEE
THE POTENTIAL FOR THUNDERSTORM ACTIVITY ACROSS THE
CWA...PRIMARILY THIS AFTERNOON/EVENING. EVEN THIS CLOSE IN
TIME...PLENTY OF MODEL DIFFERENCES REMAIN. THE GENERAL STORY LIES
WITH THAT NEXT DISTURBANCE MOVING ONTO THE PLAINS...WHICH LOOKS TO
SPARK OFF THUNDERSTORMS ACROSS THE REGION. A SURFACE TROUGH AXIS
IS EXPECTED TO PUSH SOUTH THROUGH THE DAY...BUT WHERE IT EXACTLY
ENDS UP CONTINUES TO BE DEBATED BETWEEN MODELS. THE NAM REMAINS ON
THE MORE AGGRESSIVE SIDE OF THINGS WITH THE THUNDERSTORM
DEVELOPMENT...WITH THE GFS/EC SHOWING VERY LITTLE. WITH SUPPORT
FROM THE 00Z 4KM WRF AND HRRR ALSO TRENDED MORE TOWARD THE NAM
/BUT NOT NEARLY AS WIDESPREAD/...DECIDED TO UP POPS INTO THE 30
PERCENT RANGE...MAINLY ACROSS SC NEB. DIDNT RAISE ANY HIGHER DUE
TO THOUGHT THAT THE NAMS COVERAGE COULD BE OVERDONE. DID KEEP
LINGERING POPS INTO THIS EVENING...BUT EXPECT THINGS TO BE WINDING
DOWN PRIOR TO MIDNIGHT. AS FAR AS SEVERE WEATHER GOES...FEEL THAT
WHAT THUNDERSTORMS DO DEVELOP LATER TODAY COULD BE CAPABLE OF
DAMAGING WINDS...WITH FORECAST SOUNDINGS SHOWING GOOD MIXING
POTENTIAL AND PLENTY OF DRIER AIR IN THE LOWER LEVELS. WILL GO
AHEAD AND INSERT THAT POSSIBILITY IN THE HWO. COULDNT RULE OUT
SOME QUARTER SIZE HAIL...BUT WINDS LOOK TO BE MORE A THREAT.
AS FAR AS TEMPERATURES GO...ONLY MINOR ADJUSTMENTS WERE MADE...AND
STILL EXPECTED TO BE WARMER THAN FRIDAY...AS WARMER AIR ALOFT
CONTINUES TO BUILD IN FROM THE WEST. FORECAST CURRENTLY CALLING
FOR MID 90S IN THE NORTHEAST TO 100-105 ACROSS THE SW CORNER OF
THE CWA. AS MENTIONED ABOVE...FORECAST SOUNDINGS /ESP IN THE SW/
SHOW GOOD MIXING POTENTIAL...AND AFTERNOON DEWPOINTS REFLECT THAT
POSSIBILITY. COMBINED WITH THE EXPECTED INCREASINGLY MORE
SOUTHWESTERLY COMPONENT TO THE WINDS...BY MID
AFTERNOON...EXPECTING TO SEE DEWPOINTS IN THOSE SOUTHWESTERN
LOCATIONS FALL INTO THE LOWER 50S...WHILE LOCATIONS GENERALLY
ALONG/NORTH OF I80 LOOK TO REMAIN CLOSER TO THE LOWER 60 PERCENT
RANGE. DID NOT GO WITH ANY HEAT ADV HEADLINE FOR TODAY ACROSS NC
KS /WHERE HIGHS ARE HOTTEST/...AS THE LOWER DEWPOINTS EXPECTED TO
ACCOMPANY THOSE TEMPERATURES SHOULD KEEP HEAT INDEX VALUES FROM
EXCEEDING 105 DEGREES ON A WIDESPREAD BASIS.
FORECAST FOR TODAY DID RAISE SOME CONCERNS ABOUT FIRE
WEATHER...SEE FIRE SECTION BELOW FOR MORE INFORMATION.
AS WE GET INTO SUNDAY/SUNDAY NIGHT...THUNDERSTORM CHANCES REMAIN
IN THE FORECAST. KEPT THE MORNING HOURS DRY...BUT AS THIS LATEST
DISTURBANCE MOVES THROUGH AND EVENTUALLY EAST OF THE CWA...MODELS
HAVE COME INTO BETTER AGREEMENT SHOWING THE SURFACE BOUNDARY
PUSHING FURTHER SOUTH THROUGH THE CWA...EVENTUALLY SETTLING AT
LEAST NEAR THE NEB/KS STATE LINE...IF NOT FURTHER SOUTH. DEPENDS
ON THE MODEL. HAVE SOME LOW POPS IN DURING THE AFTERNOON ACROSS
SOUTHERN PORTIONS OF THE CWA...CLOSE TO WEAR THE BOUNDARY COULD
BE. MADE LITTLE CHANGE TO THE EVENING/OVERNIGHT POPS...THE GFS
CONTINUES TO CERTAINLY BE ON THE MORE WIDESPREAD SIDE OF
THINGS...BUT FORECAST REMAINS TRENDED TOWARDS BETTER SUPPORT
JUSTIFYING LOWER POPS. MODELS SHOW AN INCREASE IN TEMPERATURES
ALOFT ACROSS THE REGION ON SUNDAY...BUT WITH THE MORE EASTERLY
COMPONENT TO THE WINDS...HARD TO GO MORE THAN A COUPLE OF DEGREES
WARMER THAN TODAY /DIDNT MAKE NOTABLE CHANGES TO THE INHERITED
TEMPERATURES/. AM CONCERNED THAT THOSE EASTERLY WINDS ARE GOING
HAVE A GREATER IMPACT ON THE TEMPERATURES /PRIMARILY ACROSS SC
NEB/...AND UPCOMING SHIFTS WILL HAVE TO TAKE A LOOK AT THAT. IF
THE BOUNDARY DOESNT GET AS FAR SOUTH AS SAY THE 06Z NAM
SUGGESTS...WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR HEAT ADV
CRITERIA ACROSS NC KS. AT THIS TIME...WITH PLENTY OF UNCERTAINTY
WASNT GOING TO GO DOWN THAT ROAD.
UNCERTAINTY WITH THE PRECIPITATION CHANCES CONTINUES INTO
MONDAY...AND KEPT LOW POPS IN PLACE ACROSS THE CWA. MODELS RANGE
FROM VERY LITTLE GOING ON ANYWHERE...TO WIDESPREAD ACTIVITY ACROSS
PORTIONS OF SC NEB...TO ACTIVITY DRIFTING INTO THE WEST FROM
EARLIER DEVELOPMENT ACROSS THE HIGH PLAINS. CANT REALLY NAIL
DOWN BETTER SPECIFICS WITH THE POPS UNTIL THERE IS BETTER
AGREEMENT WITH ANY SOLUTION BETWEEN THE MODELS. THERE IS BETTER
AGREEMENT IN REGARD TO TEMPERATURES...WHICH SHOW HIGHS BEING
COOLER THAN ON SUNDAY...WITH LOWER/MID 90S IN NEB...MID/UPPER 90S
IN KS. KEPT THE INHERITED DRY FORECAST FOR MONDAY NIGHT IN PLACE.
LONG TERM...TUESDAY THROUGH FRIDAY.
THE MAIN CONCERN FOR THE LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR SHOWERS AND THUNDERSTORMS. OTHERWISE...MADE VERY FEW
CHANGES TO THE EXTENDED.
WHILE AN UPPER LEVEL RIDGE REMAINS STEADFAST ACROSS THE WESTERN
TWO THIRDS OF THE CONUS TOWARDS THE BEGINNING OF THE LONG
TERM...AN UPPER LEVEL TROUGH OFF THE WESTERN COAST SLOWLY BEGINS
TO PUSH EASTWARD ACROSS CANADA...THUS HELPING BREAK DOWN THE UPPER
LEVEL RIDGE. IN ADDITION...NUMEROUS SHORT WAVES CONTINUE TO ROUND
THE TOP OF THE UPPER LEVEL RIDGE AND SKIRT ACROSS THE PLAINS.
ALTHOUGH TIMING AND PLACEMENT AS WELL AS RESOLUTION REMAIN
INCONSISTENT AMONG THE LONG TERM MODELS...THERE APPEARS TO BE SOME
CHANCE AT AN UPPER LEVEL DISTURBANCE PASSING THROUGH THE REGION
SOMETIME DURING THE LONG TERM PERIOD. AT THE SURFACE...LOW
PRESSURE ALONG THE NORTHERN ROCKIES IS EXPECTED TO SHIFT EASTWARD
ACROSS THE DAKOTAS...WHILE HIGH PRESSURE REMAINS SITUATED ACROSS
THE CENTRAL PLAINS...THROUGH AT LEAST THURSDAY MORNING. DEVELOPING
LOW PRESSURE ACROSS THE REGION ON THURSDAY...COMBINED WITH THE
POSSIBILITY OF AN UPPER LEVEL SHORT WAVE AND UPPER LEVEL JET
STREAK COULD CERTAINLY GENERATE SOME POPS ACROSS THE AREA. AT THIS
POINT...MODELS REMAIN TOO INCONSISTENT TO CONTINUE WITH SEVERAL
PERIODS OF SLIGHT CHANCE POPS. PER NEIGHBOR
COLLABORATION...CONTINUED A DRY FORECAST THROUGH MUCH OF THE
EXTENDED WITH THE EXCEPTION OF FRIDAY. FOR FRIDAY...MODELS ARE AT
LEAST IN AGREEMENT ON PLACEMENT OF A SURFACE LOW/TROUGH ALONG THE
HIGH PLAINS SHIFTING EASTWARD...AN UPPER LEVEL JET ACROSS PORTIONS
OF NEBRASKA...AND A WEAK UPPER LEVEL WAVE TRAVERSING THE REGION.
THUS ADDED SLIGHT CHANCES FOR POPS TO MOST OF THE OUTLOOK AREA ON
FRIDAY.
FIRE WEATHER...MAIN CONCERN IS GOING TO LIE ACROSS THE
SOUTHWESTERN THIRD OF THE CWA...WHERE THE BETTER MIXING
POTENTIAL...AND THUS LOWER DEWPOINTS AND HIGHER TEMPERATURES WILL
EXIST. DEBATED ISSUING A HEADLINE FOR PORTIONS OF NC KS THIS
AFTERNOON...AS FORECAST RELATIVE HUMIDITY VALUES ARE EXPECTED TO
FALL TO NEAR/JUST BELOW 20 PERCENT. THE LIMITING FACTOR LIES WITH
THE WINDS. THE MAJORITY OF MODEL DATA AND GUIDANCE KEEPS SUSTAINED
WIND SPEEDS BELOW CRITICAL LEVELS...AND FORECAST SOUNDINGS SHOW
THE HIGHER WINDS ALOFT/GUST POTENTIAL HAPPENING EARLIER IN THE
AFTERNOON...BEFORE THE RH VALUES DROP. CONFIDENCE IN THE WIND/WIND
GUST AND RH CRITERIA BOTH BEING MET FOR 3 HOURS WAS LOW ENOUGH TO
NOT ISSUE A HEADLINE. HOWEVER...IT WILL BE SOMETHING FOR THE DAY
SHIFT CREW TO KEEP A CLOSE EYE ON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE/AVIATION...PFANNKUCH
SHORT TERM/FIRE WEATHER...ADO
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
540 AM CDT SAT JUL 28 2012
.AVIATION...12Z KGRI TAF. A SURFACE TROUGH AXIS WILL BEGIN TO
SHIFT SOUTHEAST ACROSS THE REGION TODAY. AS A RESULT...WINDS WILL
GRADUALLY SHIFT TO BECOME MORE SOUTHERLY THIS MORNING...BEFORE
SWITCHING TO THE SOUTHWEST. BOUNDARY LAYER MIXING THIS AFTERNOON
WILL ALLOW INCREASED WINDS NEAR 15 KTS SUSTAINED AND WIND GUSTS
UP TO 20 KTS. THERE REMAINS CHANCE FOR SCATTERED SHOWERS AND
THUNDERSTORMS ACROSS CENTRAL NEBRASKA. AT THIS TIME...LEFT MENTION
OUT OF TAF DUE TO SCATTERED NATURE OF ANY STORMS THAT SHOULD
DEVELOP...BUT WILL NEED TO BE MONITORED. INCREASED CLOUDS CAN BE
EXPECTED THIS AFTERNOON AND EVENING WITH THUNDERSTORM
DEVELOPMENT...BUT EXPECTING VFR CONDITIONS THROUGHOUT THE PERIOD.
&&
.PREV DISCUSSION... /ISSUED 440 AM CDT SAT JUL 28 2012/
SHORT TERM...TODAY THROUGH MONDAY NIGHT. MULTIPLE FORECAST
CONCERNS...ESP TODAY AND SUNDAY...INCLUDING
TEMPERATURES...PRECIP CHANCES...AND FIRE WEATHER ISSUES.
SATELLITE AND UPPER LEVEL PROFILER DATA CONTINUE TO SHOW THE
REGION UNDER THE INFLUENCE OF HIGH PRESSURE/RIDGING CENTERED
OVER THE SRN PLAINS...WHILE A WEAK DISTURBANCE CONTINUES TO RIDE
AROUND THE EDGE OF THE RIDGE...CURRENTLY OVER NERN NEB/SERN SD.
ANOTHER DISTURBANCE IS CURRENTLY MAKING ITS WAY THROUGH WY...WHICH
CAN ALSO BE PICKED OUT VIA LIGHTNING DATA. WAS CONCERNED LAST
NIGHT THAT THE ACTIVITY MAY STAY JUST NORTH OF THE CWA...AND AT
THIS POINT...LOOKS LIKE HOW IT IS GOING TO TURN OUT. AT THE
SURFACE...THE CWA SITS BETWEEN HIGH PRESSURE EXTENDING FROM NRN IA
INTO ERN CANADA...AND LOW PRESSURE DRAPED ALONG THE HIGH/SRN
PLAINS...BRINGING SOUTHEASTERLY FLOW...WITH SPEEDS GENERALLY
NEAR/LESS THAN 10 MPH.
LOOKING TO THE REST OF TODAY AND INTO TONIGHT...CONTINUE TO SEE
THE POTENTIAL FOR THUNDERSTORM ACTIVITY ACROSS THE
CWA...PRIMARILY THIS AFTERNOON/EVENING. EVEN THIS CLOSE IN
TIME...PLENTY OF MODEL DIFFERENCES REMAIN. THE GENERAL STORY LIES
WITH THAT NEXT DISTURBANCE MOVING ONTO THE PLAINS...WHICH LOOKS TO
SPARK OFF THUNDERSTORMS ACROSS THE REGION. A SURFACE TROUGH AXIS
IS EXPECTED TO PUSH SOUTH THROUGH THE DAY...BUT WHERE IT EXACTLY
ENDS UP CONTINUES TO BE DEBATED BETWEEN MODELS. THE NAM REMAINS ON
THE MORE AGGRESSIVE SIDE OF THINGS WITH THE THUNDERSTORM
DEVELOPMENT...WITH THE GFS/EC SHOWING VERY LITTLE. WITH SUPPORT
FROM THE 00Z 4KM WRF AND HRRR ALSO TRENDED MORE TOWARD THE NAM
/BUT NOT NEARLY AS WIDESPREAD/...DECIDED TO UP POPS INTO THE 30
PERCENT RANGE...MAINLY ACROSS SC NEB. DIDNT RAISE ANY HIGHER DUE
TO THOUGHT THAT THE NAMS COVERAGE COULD BE OVERDONE. DID KEEP
LINGERING POPS INTO THIS EVENING...BUT EXPECT THINGS TO BE WINDING
DOWN PRIOR TO MIDNIGHT. AS FAR AS SEVERE WEATHER GOES...FEEL THAT
WHAT THUNDERSTORMS DO DEVELOP LATER TODAY COULD BE CAPABLE OF
DAMAGING WINDS...WITH FORECAST SOUNDINGS SHOWING GOOD MIXING
POTENTIAL AND PLENTY OF DRIER AIR IN THE LOWER LEVELS. WILL GO
AHEAD AND INSERT THAT POSSIBILITY IN THE HWO. COULDNT RULE OUT
SOME QUARTER SIZE HAIL...BUT WINDS LOOK TO BE MORE A THREAT.
AS FAR AS TEMPERATURES GO...ONLY MINOR ADJUSTMENTS WERE MADE...AND
STILL EXPECTED TO BE WARMER THAN FRIDAY...AS WARMER AIR ALOFT
CONTINUES TO BUILD IN FROM THE WEST. FORECAST CURRENTLY CALLING
FOR MID 90S IN THE NORTHEAST TO 100-105 ACROSS THE SW CORNER OF
THE CWA. AS MENTIONED ABOVE...FORECAST SOUNDINGS /ESP IN THE SW/
SHOW GOOD MIXING POTENTIAL...AND AFTERNOON DEWPOINTS REFLECT THAT
POSSIBILITY. COMBINED WITH THE EXPECTED INCREASINGLY MORE
SOUTHWESTERLY COMPONENT TO THE WINDS...BY MID
AFTERNOON...EXPECTING TO SEE DEWPOINTS IN THOSE SOUTHWESTERN
LOCATIONS FALL INTO THE LOWER 50S...WHILE LOCATIONS GENERALLY
ALONG/NORTH OF I80 LOOK TO REMAIN CLOSER TO THE LOWER 60 PERCENT
RANGE. DID NOT GO WITH ANY HEAT ADV HEADLINE FOR TODAY ACROSS NC
KS /WHERE HIGHS ARE HOTTEST/...AS THE LOWER DEWPOINTS EXPECTED TO
ACCOMPANY THOSE TEMPERATURES SHOULD KEEP HEAT INDEX VALUES FROM
EXCEEDING 105 DEGREES ON A WIDESPREAD BASIS.
FORECAST FOR TODAY DID RAISE SOME CONCERNS ABOUT FIRE
WEATHER...SEE FIRE SECTION BELOW FOR MORE INFORMATION.
AS WE GET INTO SUNDAY/SUNDAY NIGHT...THUNDERSTORM CHANCES REMAIN
IN THE FORECAST. KEPT THE MORNING HOURS DRY...BUT AS THIS LATEST
DISTURBANCE MOVES THROUGH AND EVENTUALLY EAST OF THE CWA...MODELS
HAVE COME INTO BETTER AGREEMENT SHOWING THE SURFACE BOUNDARY
PUSHING FURTHER SOUTH THROUGH THE CWA...EVENTUALLY SETTLING AT
LEAST NEAR THE NEB/KS STATE LINE...IF NOT FURTHER SOUTH. DEPENDS
ON THE MODEL. HAVE SOME LOW POPS IN DURING THE AFTERNOON ACROSS
SOUTHERN PORTIONS OF THE CWA...CLOSE TO WEAR THE BOUNDARY COULD
BE. MADE LITTLE CHANGE TO THE EVENING/OVERNIGHT POPS...THE GFS
CONTINUES TO CERTAINLY BE ON THE MORE WIDESPREAD SIDE OF
THINGS...BUT FORECAST REMAINS TRENDED TOWARDS BETTER SUPPORT
JUSTIFYING LOWER POPS. MODELS SHOW AN INCREASE IN TEMPERATURES
ALOFT ACROSS THE REGION ON SUNDAY...BUT WITH THE MORE EASTERLY
COMPONENT TO THE WINDS...HARD TO GO MORE THAN A COUPLE OF DEGREES
WARMER THAN TODAY /DIDNT MAKE NOTABLE CHANGES TO THE INHERITED
TEMPERATURES/. AM CONCERNED THAT THOSE EASTERLY WINDS ARE GOING
HAVE A GREATER IMPACT ON THE TEMPERATURES /PRIMARILY ACROSS SC
NEB/...AND UPCOMING SHIFTS WILL HAVE TO TAKE A LOOK AT THAT. IF
THE BOUNDARY DOESNT GET AS FAR SOUTH AS SAY THE 06Z NAM
SUGGESTS...WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR HEAT ADV
CRITERIA ACROSS NC KS. AT THIS TIME...WITH PLENTY OF UNCERTAINTY
WASNT GOING TO GO DOWN THAT ROAD.
UNCERTAINTY WITH THE PRECIPITATION CHANCES CONTINUES INTO
MONDAY...AND KEPT LOW POPS IN PLACE ACROSS THE CWA. MODELS RANGE
FROM VERY LITTLE GOING ON ANYWHERE...TO WIDESPREAD ACTIVITY ACROSS
PORTIONS OF SC NEB...TO ACTIVITY DRIFTING INTO THE WEST FROM
EARLIER DEVELOPMENT ACROSS THE HIGH PLAINS. CANT REALLY NAIL
DOWN BETTER SPECIFICS WITH THE POPS UNTIL THERE IS BETTER
AGREEMENT WITH ANY SOLUTION BETWEEN THE MODELS. THERE IS BETTER
AGREEMENT IN REGARD TO TEMPERATURES...WHICH SHOW HIGHS BEING
COOLER THAN ON SUNDAY...WITH LOWER/MID 90S IN NEB...MID/UPPER 90S
IN KS. KEPT THE INHERITED DRY FORECAST FOR MONDAY NIGHT IN PLACE.
LONG TERM...TUESDAY THROUGH FRIDAY.
THE MAIN CONCERN FOR THE LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR SHOWERS AND THUNDERSTORMS. OTHERWISE...MADE VERY FEW
CHANGES TO THE EXTENDED.
WHILE AN UPPER LEVEL RIDGE REMAINS STEADFAST ACROSS THE WESTERN
TWO THIRDS OF THE CONUS TOWARDS THE BEGINNING OF THE LONG
TERM...AN UPPER LEVEL TROUGH OFF THE WESTERN COAST SLOWLY BEGINS
TO PUSH EASTWARD ACROSS CANADA...THUS HELPING BREAK DOWN THE UPPER
LEVEL RIDGE. IN ADDITION...NUMEROUS SHORT WAVES CONTINUE TO ROUND
THE TOP OF THE UPPER LEVEL RIDGE AND SKIRT ACROSS THE PLAINS.
ALTHOUGH TIMING AND PLACEMENT AS WELL AS RESOLUTION REMAIN
INCONSISTENT AMONG THE LONG TERM MODELS...THERE APPEARS TO BE SOME
CHANCE AT AN UPPER LEVEL DISTURBANCE PASSING THROUGH THE REGION
SOMETIME DURING THE LONG TERM PERIOD. AT THE SURFACE...LOW
PRESSURE ALONG THE NORTHERN ROCKIES IS EXPECTED TO SHIFT EASTWARD
ACROSS THE DAKOTAS...WHILE HIGH PRESSURE REMAINS SITUATED ACROSS
THE CENTRAL PLAINS...THROUGH AT LEAST THURSDAY MORNING. DEVELOPING
LOW PRESSURE ACROSS THE REGION ON THURSDAY...COMBINED WITH THE
POSSIBILITY OF AN UPPER LEVEL SHORT WAVE AND UPPER LEVEL JET
STREAK COULD CERTAINLY GENERATE SOME POPS ACROSS THE AREA. AT THIS
POINT...MODELS REMAIN TOO INCONSISTENT TO CONTINUE WITH SEVERAL
PERIODS OF SLIGHT CHANCE POPS. PER NEIGHBOR
COLLABORATION...CONTINUED A DRY FORECAST THROUGH MUCH OF THE
EXTENDED WITH THE EXCEPTION OF FRIDAY. FOR FRIDAY...MODELS ARE AT
LEAST IN AGREEMENT ON PLACEMENT OF A SURFACE LOW/TROUGH ALONG THE
HIGH PLAINS SHIFTING EASTWARD...AN UPPER LEVEL JET ACROSS PORTIONS
OF NEBRASKA...AND A WEAK UPPER LEVEL WAVE TRAVERSING THE REGION.
THUS ADDED SLIGHT CHANCES FOR POPS TO MOST OF THE OUTLOOK AREA ON
FRIDAY.
FIRE WEATHER...MAIN CONCERN IS GOING TO LIE ACROSS THE
SOUTHWESTERN THIRD OF THE CWA...WHERE THE BETTER MIXING
POTENTIAL...AND THUS LOWER DEWPOINTS AND HIGHER TEMPERATURES WILL
EXIST. DEBATED ISSUING A HEADLINE FOR PORTIONS OF NC KS THIS
AFTERNOON...AS FORECAST RELATIVE HUMIDITY VALUES ARE EXPECTED TO
FALL TO NEAR/JUST BELOW 20 PERCENT. THE LIMITING FACTOR LIES WITH
THE WINDS. THE MAJORITY OF MODEL DATA AND GUIDANCE KEEPS SUSTAINED
WIND SPEEDS BELOW CRITICAL LEVELS...AND FORECAST SOUNDINGS SHOW
THE HIGHER WINDS ALOFT/GUST POTENTIAL HAPPENING EARLIER IN THE
AFTERNOON...BEFORE THE RH VALUES DROP. CONFIDENCE IN THE WIND/WIND
GUST AND RH CRITERIA BOTH BEING MET FOR 3 HOURS WAS LOW ENOUGH TO
NOT ISSUE A HEADLINE. HOWEVER...IT WILL BE SOMETHING FOR THE DAY
SHIFT CREW TO KEEP A CLOSE EYE ON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT/FIRE WEATHER...ADO
LONG/AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
440 AM CDT SAT JUL 28 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT. MULTIPLE FORECAST
CONCERNS...ESP TODAY AND SUNDAY...INCLUDING
TEMPERATURES...PRECIP CHANCES...AND FIRE WEATHER ISSUES.
SATELLITE AND UPPER LEVEL PROFILER DATA CONTINUE TO SHOW THE
REGION UNDER THE INFLUENCE OF HIGH PRESSURE/RIDGING CENTERED
OVER THE SRN PLAINS...WHILE A WEAK DISTURBANCE CONTINUES TO RIDE
AROUND THE EDGE OF THE RIDGE...CURRENTLY OVER NERN NEB/SERN SD.
ANOTHER DISTURBANCE IS CURRENTLY MAKING ITS WAY THROUGH WY...WHICH
CAN ALSO BE PICKED OUT VIA LIGHTNING DATA. WAS CONCERNED LAST
NIGHT THAT THE ACTIVITY MAY STAY JUST NORTH OF THE CWA...AND AT
THIS POINT...LOOKS LIKE HOW IT IS GOING TO TURN OUT. AT THE
SURFACE...THE CWA SITS BETWEEN HIGH PRESSURE EXTENDING FROM NRN IA
INTO ERN CANADA...AND LOW PRESSURE DRAPED ALONG THE HIGH/SRN
PLAINS...BRINGING SOUTHEASTERLY FLOW...WITH SPEEDS GENERALLY
NEAR/LESS THAN 10 MPH.
LOOKING TO THE REST OF TODAY AND INTO TONIGHT...CONTINUE TO SEE
THE POTENTIAL FOR THUNDERSTORM ACTIVITY ACROSS THE
CWA...PRIMARILY THIS AFTERNOON/EVENING. EVEN THIS CLOSE IN
TIME...PLENTY OF MODEL DIFFERENCES REMAIN. THE GENERAL STORY LIES
WITH THAT NEXT DISTURBANCE MOVING ONTO THE PLAINS...WHICH LOOKS TO
SPARK OFF THUNDERSTORMS ACROSS THE REGION. A SURFACE TROUGH AXIS
IS EXPECTED TO PUSH SOUTH THROUGH THE DAY...BUT WHERE IT EXACTLY
ENDS UP CONTINUES TO BE DEBATED BETWEEN MODELS. THE NAM REMAINS ON
THE MORE AGGRESSIVE SIDE OF THINGS WITH THE THUNDERSTORM
DEVELOPMENT...WITH THE GFS/EC SHOWING VERY LITTLE. WITH SUPPORT
FROM THE 00Z 4KM WRF AND HRRR ALSO TRENDED MORE TOWARD THE NAM
/BUT NOT NEARLY AS WIDESPREAD/...DECIDED TO UP POPS INTO THE 30
PERCENT RANGE...MAINLY ACROSS SC NEB. DIDNT RAISE ANY HIGHER DUE
TO THOUGHT THAT THE NAMS COVERAGE COULD BE OVERDONE. DID KEEP
LINGERING POPS INTO THIS EVENING...BUT EXPECT THINGS TO BE WINDING
DOWN PRIOR TO MIDNIGHT. AS FAR AS SEVERE WEATHER GOES...FEEL THAT
WHAT THUNDERSTORMS DO DEVELOP LATER TODAY COULD BE CAPABLE OF
DAMAGING WINDS...WITH FORECAST SOUNDINGS SHOWING GOOD MIXING
POTENTIAL AND PLENTY OF DRIER AIR IN THE LOWER LEVELS. WILL GO
AHEAD AND INSERT THAT POSSIBILITY IN THE HWO. COULDNT RULE OUT
SOME QUARTER SIZE HAIL...BUT WINDS LOOK TO BE MORE A THREAT.
AS FAR AS TEMPERATURES GO...ONLY MINOR ADJUSTMENTS WERE MADE...AND
STILL EXPECTED TO BE WARMER THAN FRIDAY...AS WARMER AIR ALOFT
CONTINUES TO BUILD IN FROM THE WEST. FORECAST CURRENTLY CALLING
FOR MID 90S IN THE NORTHEAST TO 100-105 ACROSS THE SW CORNER OF
THE CWA. AS MENTIONED ABOVE...FORECAST SOUNDINGS /ESP IN THE SW/
SHOW GOOD MIXING POTENTIAL...AND AFTERNOON DEWPOINTS REFLECT THAT
POSSIBILITY. COMBINED WITH THE EXPECTED INCREASINGLY MORE
SOUTHWESTERLY COMPONENT TO THE WINDS...BY MID
AFTERNOON...EXPECTING TO SEE DEWPOINTS IN THOSE SOUTHWESTERN
LOCATIONS FALL INTO THE LOWER 50S...WHILE LOCATIONS GENERALLY
ALONG/NORTH OF I80 LOOK TO REMAIN CLOSER TO THE LOWER 60 PERCENT
RANGE. DID NOT GO WITH ANY HEAT ADV HEADLINE FOR TODAY ACROSS NC
KS /WHERE HIGHS ARE HOTTEST/...AS THE LOWER DEWPOINTS EXPECTED TO
ACCOMPANY THOSE TEMPERATURES SHOULD KEEP HEAT INDEX VALUES FROM
EXCEEDING 105 DEGREES ON A WIDESPREAD BASIS.
FORECAST FOR TODAY DID RAISE SOME CONCERNS ABOUT FIRE
WEATHER...SEE FIRE SECTION BELOW FOR MORE INFORMATION.
AS WE GET INTO SUNDAY/SUNDAY NIGHT...THUNDERSTORM CHANCES REMAIN
IN THE FORECAST. KEPT THE MORNING HOURS DRY...BUT AS THIS LATEST
DISTURBANCE MOVES THROUGH AND EVENTUALLY EAST OF THE CWA...MODELS
HAVE COME INTO BETTER AGREEMENT SHOWING THE SURFACE BOUNDARY
PUSHING FURTHER SOUTH THROUGH THE CWA...EVENTUALLY SETTLING AT
LEAST NEAR THE NEB/KS STATE LINE...IF NOT FURTHER SOUTH. DEPENDS
ON THE MODEL. HAVE SOME LOW POPS IN DURING THE AFTERNOON ACROSS
SOUTHERN PORTIONS OF THE CWA...CLOSE TO WEAR THE BOUNDARY COULD
BE. MADE LITTLE CHANGE TO THE EVENING/OVERNIGHT POPS...THE GFS
CONTINUES TO CERTAINLY BE ON THE MORE WIDESPREAD SIDE OF
THINGS...BUT FORECAST REMAINS TRENDED TOWARDS BETTER SUPPORT
JUSTIFYING LOWER POPS. MODELS SHOW AN INCREASE IN TEMPERATURES
ALOFT ACROSS THE REGION ON SUNDAY...BUT WITH THE MORE EASTERLY
COMPONENT TO THE WINDS...HARD TO GO MORE THAN A COUPLE OF DEGREES
WARMER THAN TODAY /DIDNT MAKE NOTABLE CHANGES TO THE INHERITED
TEMPERATURES/. AM CONCERNED THAT THOSE EASTERLY WINDS ARE GOING
HAVE A GREATER IMPACT ON THE TEMPERATURES /PRIMARILY ACROSS SC
NEB/...AND UPCOMING SHIFTS WILL HAVE TO TAKE A LOOK AT THAT. IF
THE BOUNDARY DOESNT GET AS FAR SOUTH AS SAY THE 06Z NAM
SUGGESTS...WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR HEAT ADV
CRITERIA ACROSS NC KS. AT THIS TIME...WITH PLENTY OF UNCERTAINTY
WASNT GOING TO GO DOWN THAT ROAD.
UNCERTAINTY WITH THE PRECIPITATION CHANCES CONTINUES INTO
MONDAY...AND KEPT LOW POPS IN PLACE ACROSS THE CWA. MODELS RANGE
FROM VERY LITTLE GOING ON ANYWHERE...TO WIDESPREAD ACTIVITY ACROSS
PORTIONS OF SC NEB...TO ACTIVITY DRIFTING INTO THE WEST FROM
EARLIER DEVELOPMENT ACROSS THE HIGH PLAINS. CANT REALLY NAIL
DOWN BETTER SPECIFICS WITH THE POPS UNTIL THERE IS BETTER
AGREEMENT WITH ANY SOLUTION BETWEEN THE MODELS. THERE IS BETTER
AGREEMENT IN REGARD TO TEMPERATURES...WHICH SHOW HIGHS BEING
COOLER THAN ON SUNDAY...WITH LOWER/MID 90S IN NEB...MID/UPPER 90S
IN KS. KEPT THE INHERITED DRY FORECAST FOR MONDAY NIGHT IN PLACE.
.LONG TERM...TUESDAY THROUGH FRIDAY.
THE MAIN CONCERN FOR THE LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR SHOWERS AND THUNDERSTORMS. OTHERWISE...MADE VERY FEW
CHANGES TO THE EXTENDED.
WHILE AN UPPER LEVEL RIDGE REMAINS STEADFAST ACROSS THE WESTERN
TWO THIRDS OF THE CONUS TOWARDS THE BEGINNING OF THE LONG
TERM...AN UPPER LEVEL TROUGH OFF THE WESTERN COAST SLOWLY BEGINS
TO PUSH EASTWARD ACROSS CANADA...THUS HELPING BREAK DOWN THE UPPER
LEVEL RIDGE. IN ADDITION...NUMEROUS SHORT WAVES CONTINUE TO ROUND
THE TOP OF THE UPPER LEVEL RIDGE AND SKIRT ACROSS THE PLAINS.
ALTHOUGH TIMING AND PLACEMENT AS WELL AS RESOLUTION REMAIN
INCONSISTENT AMONG THE LONG TERM MODELS...THERE APPEARS TO BE SOME
CHANCE AT AN UPPER LEVEL DISTURBANCE PASSING THROUGH THE REGION
SOMETIME DURING THE LONG TERM PERIOD. AT THE SURFACE...LOW
PRESSURE ALONG THE NORTHERN ROCKIES IS EXPECTED TO SHIFT EASTWARD
ACROSS THE DAKOTAS...WHILE HIGH PRESSURE REMAINS SITUATED ACROSS
THE CENTRAL PLAINS...THROUGH AT LEAST THURSDAY MORNING. DEVELOPING
LOW PRESSURE ACROSS THE REGION ON THURSDAY...COMBINED WITH THE
POSSIBILITY OF AN UPPER LEVEL SHORT WAVE AND UPPER LEVEL JET
STREAK COULD CERTAINLY GENERATE SOME POPS ACROSS THE AREA. AT THIS
POINT...MODELS REMAIN TOO INCONSISTENT TO CONTINUE WITH SEVERAL
PERIODS OF SLIGHT CHANCE POPS. PER NEIGHBOR
COLLABORATION...CONTINUED A DRY FORECAST THROUGH MUCH OF THE
EXTENDED WITH THE EXCEPTION OF FRIDAY. FOR FRIDAY...MODELS ARE AT
LEAST IN AGREEMENT ON PLACEMENT OF A SURFACE LOW/TROUGH ALONG THE
HIGH PLAINS SHIFTING EASTWARD...AN UPPER LEVEL JET ACROSS PORTIONS
OF NEBRASKA...AND A WEAK UPPER LEVEL WAVE TRAVERSING THE REGION.
THUS ADDED SLIGHT CHANCES FOR POPS TO MOST OF THE OUTLOOK AREA ON
FRIDAY.
&&
.AVIATION...06Z KGRI TAF. VFR CONDITIONS ARE EXPECTED TO CONTINUE
THROUGHOUT THE TAF PERIOD. HOWEVER...A SURFACE LOW PRESSURE
SYSTEM/TROUGH AXIS WILL GRADUALLY SHIFT EASTWARD ALONG THE HIGH
PLAINS TODAY. AS A RESULT...SOUTHEAST WINDS WILL GRADUALLY SHIFT
TO MORE SOUTHERLY THIS MORNING AND EVENTUALLY TO THE SOUTHWEST
THIS AFTERNOON. WITH GOOD BOUNDARY LAYER MIXING THIS
AFTERNOON...WIND SPEEDS NEAR 15 KTS WITH GUSTS NEAR 20 KTS CAN BE
EXPECTED BEFORE BECOMING LIGHT AND VARIABLE IN THE EVENING. A
SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS ALSO REMAINS POSSIBLE
THIS AFTERNOON AND EVENING...ESPECIALLY ACROSS NORTHERN NEBRASKA.
AT THIS TIME...NOT EXPECTING THESE SHOWERS TO SHIFT THROUGH THE
TAF SITE...SINCE THEY WILL LIKELY BE SCATTERED IN NATURE...BUT
SHOULD BE MONITORED. INCREASED CLOUD COVER WILL BE POSSIBLE THIS
AFTERNOON...SHOULD THUNDERSTORMS DEVELOP ACROSS NORTHERN NEBRASKA.
&&
.FIRE WEATHER...MAIN CONCERN IS GOING TO LIE ACROSS THE
SOUTHWESTERN THIRD OF THE CWA...WHERE THE BETTER MIXING
POTENTIAL...AND THUS LOWER DEWPOINTS AND HIGHER TEMPERATURES WILL
EXIST. DEBATED ISSUING A HEADLINE FOR PORTIONS OF NC KS THIS
AFTERNOON...AS FORECAST RELATIVE HUMIDITY VALUES ARE EXPECTED TO
FALL TO NEAR/JUST BELOW 20 PERCENT. THE LIMITING FACTOR LIES WITH
THE WINDS. THE MAJORITY OF MODEL DATA AND GUIDANCE KEEPS SUSTAINED
WIND SPEEDS BELOW CRITICAL LEVELS...AND FORECAST SOUNDINGS SHOW
THE HIGHER WINDS ALOFT/GUST POTENTIAL HAPPENING EARLIER IN THE
AFTERNOON...BEFORE THE RH VALUES DROP. CONFIDENCE IN THE WIND/WIND
GUST AND RH CRITERIA BOTH BEING MET FOR 3 HOURS WAS LOW ENOUGH TO
NOT ISSUE A HEADLINE. HOWEVER...IT WILL BE SOMETHING FOR THE DAY
SHIFT CREW TO KEEP A CLOSE EYE ON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT/FIRE WEATHER...ADO
LONG/AVIATION...SALTZMAN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
359 PM CDT SAT JUL 28 2012
.SHORT TERM...NOW THROUGH SUNDAY MORNING...
THE MAIN PROBLEM OF THE DAY IS WITH TIMING AND COVERAGE OF
PRECIPITATION WITH SEVERAL MIDDLE LEVEL IMPULSES OVER CONUS
NOW AIMED AT NORTH DAKOTA...PER WATER VAPOR SATELLITE IMAGERY.
SHOWERS AND THUNDERSTORMS ARE MAINTAINING COVERAGE AND INTENSITY
ALONG I94 CORRIDOR PER 20 UTC RADAR IMAGERY. THE PERSISTENCE OF
THIS FEATURE/CONVECTION OUTLINES THE LOW PREDICTABILITY
ASSOCIATED WITH WEAK MIDDLE LEVEL SHORTWAVES MOVING OVER A CAPPED
AND MODESTLY CONVECTIVELY UNSTABLE ENVIRONMENT. AS A RESULT OF
MAINTENANCE...FORECAST GRIDS HAVE BEEN REACTIVELY UPDATED TO
REFLECT EASTWARD PROPAGATION THROUGH MIDNIGHT.
CURRENT RADAR IMAGERY ALSO INDICATES A STRONG/SEVERE THUNDERSTORM
PRESENTLY OVER SOUTHEASTERN SASKATCHEWAN IS RIGHT MOVING TOWARD
DIVIDE COUNTY...AND SHOULD BE ENTERING THE AREA BY 5 PM CDT. THERE
MAY BE SUFFICIENTLY-DEFINED DYNAMIC SUPPORT MECHANISM FOR A SEVERE
WEATHER THREAT THIS EVENING. TRENDS WILL BE MONITORED.
THE 16 AND 17 UTC HRRR BOTH SUPPORT CONVECTION FORMING SOON AND
IMPACTING NORTHERN NORTH DAKOTA UNTIL JUST AFTER SUNSET. THEY THEN
DIRECT ADDITIONAL CONVECTION INTO WESTERN NORTH DAKOTA TONIGHT AS
THE IMPULSE OVER SOUTHWESTERN MONTANA ADVECTS EASTWARD.
THEREAFTER...SEVERAL SHORTWAVES ARE FORECAST TO MOVE ACROSS THE
DAKOTAS...BUT PREDICTABILITY IS LOW. FORECASTS REFLECT A BLEND OF
09 UTC SREF MEAN WITH ASSORTED MOS GUIDANCE.
TEMPERATURES WILL GENERALLY REMAIN ABOVE AVERAGE THROUGH THE
PERIOD.
.LONG TERM...MONDAY THROUGH SATURDAY...
THE WESTERN ROCKIES AND HIGH PLAINS RIDGE REMAINS QUITE STRONG
THROUGH THE FIRST PART OF THE EXTENDED PERIOD WITH PERIODIC CLOSED
LOWS AND SHORTWAVES TOPPING RIDGE BRINGING EPISODES OF THUNDERSTORMS
TO THE FORECAST AREA.
ON MONDAY THE UPPER RIDGE IS WEST OF THE FORECAST AREA...AND WE HAVE
NORTHWEST FLOW ALOFT OVER THE STATE WITH A COOL AND DRY SURFACE HIGH
PRESSURE SYSTEM OVER MANITOBA/MINNESOTA/EASTERN DAKOTAS WHICH SHOULD
KEEP THE AREA FREE FROM CONVECTION.
HOWEVER MONDAY NIGHT AND TUESDAY THE UPPER LEVEL RIDGE MOVES EAST
INTO THE DAKOTAS WITH THE LEADING EDGE OF A CLUSTER OF SHORTWAVE
IMPULSES. A SURFACE LOW/TROUGH THAT DEVELOPS IN RESPONSE IN THE LEE
OF THE ROCKIES MOVES INTO THE WESTERN DAKOTAS DURING THE DAY
TUESDAY. THUS HAVE RAISED CHANCES OF THUNDERSTORMS FOR MONDAY NIGHT
AND TUESDAY A BIT.
TUESDAY NIGHT THROUGH THURSDAY THE TIMING OF SHORT WAVES IS
DIFFICULT AND CONFIDENCE LOW IN PRECIPITATION CHANCES. THUS SPOTTY
SLIGHT CHANCES OF PRECIPITATION THESE TIME PERIODS.
LATE IN THE EXTENDED PERIOD...BEGINNING THURSDAY NIGHT...THE UPPER
LEVEL RIDGE FLATTENS AS A STRONGER SYSTEM ROTATES AROUND HUDSON BAY
LOW AND AND SECONDARY CLOSED FORMS OVER THE CANADIAN PRAIRIE
PROVINCES BRINGING COOLER TEMPERATURES AND INCREASED CHANCES OF
PRECIPITATION TO THE NORTHERN PLAINS.
HIGH TEMPERATURES IN THE MID 80S TO MID 90S FOR MONDAY THROUGH
WEDNESDAY...THEN A COOLING TREND AT THE END OF THE WEEK AS THE
AFOREMENTIONED UPPER LEVEL LOW FROM THE CANADIAN PRAIRIES MOVES
ACROSS THE FORECAST AREA.
&&
.AVIATION...
LARGE AREA OF SHOWERS AND ISOLATED TSTMS AROUND KBIS AND SOUTH TO
THE SD BORDER SHOULD MOVE EWD AND AFFECT KJMS AFT 23Z. TSTMS HAD
DEVELOPED OVER S CENTRAL SASK AND WERE MOVING SEWD...LIKELY
ASSOCIATED WITH A DISTURBANCE THAT IS FORECAST TO MOVE E/SE ACROSS
THE NRN TIER OF COUNTIES - MAINLY N OF KISN...BUT MAY AFFECT KMOT
TAF SITE. LATER TAF ISSUANCES TO PINPOINT BETTER CONFIDENCE IN
TIMING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SCHECK
LONG TERM/AVIATION....JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
101 PM CDT SAT JUL 28 2012
.DISCUSSION...
ONGOING SHOWERS ARE EXPANDING IN COVERAGE PER RADAR IMAGERY...AND
LIGHTENING OVERLAY SHOWS A FEW LIGHTENING STRIKES EVERY HOUR OR SO.
THESE TRENDS SUGGEST THAT A BLEND OF THE 09 UTC SREF MEAN AND 15
UTC HRRR WILL BE BEST IN THE SHORT TERM FOR PRECIPITATION CHANCES.
THUS...UPDATED FORECAST INDICATES MUCH GREATER CHANCES ALONG I94
CORRIDOR. CLOUD GRIDS HAVE ALSO BEEN UPDATED TO REFLECT THESE
TRENDS.
THE MAIN PROBLEM OF THE DAY IS WITH TIMING AND COVERAGE OF
PRECIPITATION AS AT LEAST FOUR MIDDLE LEVEL IMPULSES OVER CONUS
ARE AIMED AT NORTH DAKOTA.
&&
.AVIATION...
18Z TAF ISSUANCE...RATHER LARGE AREA OF SHOWERS BETWEEN KDIK AND
KBIS IS MOVING WEST TO EAST. 18Z-00Z ONLY ISOLATED/SCATTERED
CONVECTION EXPECTED. DID NOT MENTION VCTS OR VCSH IN TAFS AFT
00Z...MAINLY WITH EXPECTATION OF ANOTHER DISTURBANCE ACROSS THE
NRN TIER OF COUNTIES - MAINLY NORTH OF KISN/KMOT. KJMS MAY SEE
VCTS IN LATER ISSUANCE AS WELL. LATER TAF ISSUANCES TO PINPOINT
BETTER CONFIDENCE IN TIMING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...SCHECK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1136 AM CDT SAT JUL 28 2012
.DISCUSSION...EARLY CONVECTIVE THREAT HAS SLID MAINLY ACROSS EASTERN
SD INTO SWRN MN... MISSING THE SOUTHERN RRV ENTIRELY. MEANWHILE...
SCATTERED MID TO UPPER LVL CLOUDS ACROSS THE FA HAVE SLOWED THE
HEATING CURVE A BIT. EXPECT MAX TEMPS TO STILL REACH MID 80S IN MOST
LOCATIONS.
A DEVELOPING CONVECTIVE AREA IN WESTERN ND IS LIFTING TOWARDS CNTRL
ND ATTM AND STILL HAS POTENTIAL TO EXPAND INTO ERN ND THROUGH LATE
AFTERNOON AS PER CURRENT RAP GUIDANCE. CURRENT SHREF AND NAM
SOLUTIONS TEND TO SHEAR AND DIMINISH THIS IMPULSE... WHILE FAVORING
A LATER AND MORE NORTHERLY TRACKING IMPULSE /NOW MOVING ACROSS SRN
SASK/ FOR SOME EVENING AND OVERNIGHT CONVECTIVE THREAT.
&&
.AVIATION...
SCATTERED MID TO UPPER LEVEL CLOUDS AND LIGHT TO MODERATE SOUTHERLY
WINDS EXPECTED THROUGH THE AFTERNOON AND EARLY EVENING. ISOLATED
SHOWERS AND THUNDERSTORMS POSSIBLE LATE EVENING IN EASTERN ND AND
OVERNIGHT INTO NWR MN.
&&
.PREVIOUS DISCUSSION.../ISSUED 346 AM CDT SAT JUL 28 2012/
LARGE SCALE PATTERN WILL UNDERGO LITTLE CHANGE THROUGH THIS
PERIOD. WATER VAPOR IMAGERY INDICATES MULTIPLE SHORTWAVES THAT
COULD BRING THUNDER CHANCES TO THE REGION OVER THE NEXT COUPLE
DAYS. ONE SUCH WAVE BRINGS SHOWER/THUNDER CHANCES TO THE SW FA
THIS MORNING. THERE IS ANOTHER SHORTWAVE IN WESTERN MONTANA (AT
08Z) THAT SHOULD TRACK ALONG OR JUST NORTH OF THE INTERNATIONAL
BORDER TODAY INTO TONIGHT. DEPENDING ON EXACT TIMING AND
LOCATION...THIS COULD PROVIDE ENOUGH FORCING FOR SCATTERED THUNDER
ACROSS THE NORTHERN FA MAINLY TONIGHT. MODELS INDICATE INCREASING
850MB CAPE AND 0-6KM DEEP LAYER SHEAR OF 30-35 KNOTS...WHICH COULD
LEAD TO A FEW STRONGER STORMS. LOW LEVEL JET IS WEAK...AND COVERAGE
SHOULD BE LIMITED.
A STRONGER SHORTWAVE CURRENTLY (08Z) ACROSS SOUTHWEST CANADA WILL
ROUND THE UPPER RIDGE AND TRACK INTO NORTHERN MINNESOTA BY 06Z
MONDAY...SENDING A COLD FRONT THROUGH THE REGION SUNDAY
AFTERNOON/EVENING. STRONGEST FORCING AND BEST STORM COVERAGE
SHOULD BE ACROSS THE NORTHERN FA. DEEP LAYER SHEAR WILL BE AOA 40
KNOTS ACROSS THE NORTH...AND MLCAPE VALUES COULD BE MODERATE. THE
MAIN QUESTION FOR SEVERE POTENTIAL WILL BE TIMING OF THE UPPER
WAVE (AND STRONGEST FORCING). SUNDAY AFTERNOON AND EVENING HAS THE
POTENTIAL TO BE BUSY (ESPECIALLY ACROSS THE NORTHERN FA).
LOW-LEVEL RIDGING AND A DRIER AIRMASS WILL MOVE INTO THE REGION ON
MONDAY.
TEMPERATURES WILL BE BACK TO SLIGHTLY ABOVE NORMAL VALUES...WITH
THE WARMEST DAY BEING SUNDAY AS MAX TEMPS SHOULD BE ABLE TO RISE
INTO THE 90S AHEAD OF THE STRONGER WAVE.
LONG TERM (TUESDAY-FRIDAY)...MODELS IN GENERAL AGREEMENT THAT START
OF EXTENDED WILL BE RELATIVELY RAIN FREE AS SURFACE HIGH PRESSURE
BUILDS IN BEHIND DEPARTING FRONT. RETURN FLOW DEVELOPS TUESDAY
SETTING THE STAGE FOR NEXT SIGNIFICANT THREAT FOR SHOWERS AND
STORMS. DGEX APPEARS TO BE ODD MODEL OUT WITH WHAT LOOKS LIKE AN MCS
12Z-18Z TUESDAY...ALTHOUGH GEM-NH ABOUT 12 HOURS SLOWER ON SIMILAR
TRACK ACROSS SOUTHERN RRV.
FROM THE MASS FIELDS STANDPOINT THERE IS SUPPORT FOR TSRA WITH 850
MOIST FLUX DIV...700 WAA AND 250MB DIVERGENCE SUGGESTING ELEVATED
CONVECTION POSSIBLE. ALLBLEND SUPPORT THE SLOWER SOLUTION IN THE
00Z - 12Z WEDNESDAY TIME PERIOD...WHICH IS IN LINE WITH THE GFS
AND ECMWF SOLUTIONS AS WELL.
TEMPERATURES REMAIN WELL ABOVE NORMAL TUESDAY - WEDNESDAY AS UPPER
RIDGE MAINTAINS AND LITTLE IN THE WAY OF IMMEDIATE COOLING BEHIND
WIND-SHIFT FORECAST IN THE EARLY THURSDAY TIME FRAME. LIKE THE
SLOWER ECMWF...BUT NET RESULT SIMILAR IN THAT COOLER AIR FOR
THURSDAY AND FRIDAY BRINGING TEMPERATURES DOWN TO NEAR EARLY AUGUST
NORMALS.
LATE PERIOD RETURN FLOW SETS THE STAGE AGAIN FOR THREAT OF
CONVECTION AS LARGE SCALE PATTERN SUPPORTS ENERGETIC WEST/NORTHWEST
FLOW INTO THE PLAINS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
GUST/WB/JAM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1010 AM CDT SAT JUL 28 2012
.DISCUSSION...
THE SHORTWAVE IMPULSE NEAR KDIK PER 1445 UTC SATELLITE IMAGERY
WILL SLIDE EASTWARD TODAY. THE 12 UTC HRRR SUGGESTS THAT THIS
FEATURE WILL PROVIDE AMPLE BROAD SCALE ASCENT TO BREAK THE WEAK
CAP CURRENTLY OVER THE AREA AROUND 18 OR 19 UTC. SKY AND
PRECIPITATION GRIDS HAVE BEEN ADJUSTED ACCORDINGLY...WITH SOME
RESPECT ALSO GIVEN TO THE 09 UTC SREF MEAN.
THE MAIN FORECAST PROBLEM TODAY WILL BE TIMING AND COVERAGE OF
THUNDERSTORMS AND THE THREAT OF SEVERE WEATHER.
&&
.AVIATION...
ADDED VCTS TO KDIK FOR A COUPLE OF HOURS AS CONVECTION DEVELOPED
WEST OF THE TAF SITE AND CONTINUED TO MOVE EASTWARD TOWARDS KDIK.
EXPECT AMENDMENTS TO TAFS THROUGH THE DAY AS MODELS ARE DEPICTING
SMALL UPPER LEVEL DISTURBANCES MOVING WEST TO EAST ACROSS THE STATE
TODAY...AND THINK CONVECTION MAY DEVELOP ON AND OFF DURING THE
AFTERNOON. OTHERWISE VFR CONDITIONS EXPECTED FOR ALL TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...SCHECK
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1133 PM CDT FRI JUL 27 2012
.DISCUSSION...LATEST WATER VAPOR IMAGERY SHOWS A BROAD UPPER LEVEL
RIDGE HOLDING STEADY OVER THE CENTRAL AND NORTHERN HIGH PLAINS
WITH PLENTY OF SHORTWAVES ROTATING AROUND THE PERIPHERY. THE LATEST
NAM AND SREF INDICATE THAT UPPER LEVEL DIVERGENCE WILL INCREASE
ACROSS WESTERN AND SOUTH CENTRAL NORTH DAKOTA THE REST OF THE
NIGHT AS AN EJECTING SHORTWAVE NOW IN SOUTH CENTRAL MONTANA
APPROACHES. HENCE A CHANCE FOR SHOWERS/THUNDERSTORMS CONTINUE FOR
WESTERN AND SOUTH CENTRAL NORTH DAKOTA. THE LATEST HRRR WHICH HAS
BEEN OVERDOING THE CURRENT PRECIPITATION IS COMING MORE IN LINE
WITH WHAT IS ACTUALLY OCCURRING AND IT DEVELOPS PRECIPITATION IN
ROUGHLY THE SAME AREA AS THE NAM/SREF OVERNIGHT. ONLY MADE MINOR
CHANGES TO THE POP COVERAGE PER NAM/SREF/HRRR AS THE MAIN
FORECAST ALREADY HAD A GOOD HANDLE ON THE SCENARIO.
&&
.AVIATION...A STATIONARY FRONTAL BOUNDARY ACROSS EASTERN MONTANA
INTO WESTERN SOUTH DAKOTA...IS FORECAST TO MOVE INTO WESTERN NORTH
DAKOTA BY SATURDAY EVENING. THE FRONT WILL BE THE FOCUS FOR
SHOWERS AND SCATTERED THUNDERSTORMS ACROSS WESTERN AND SOUTHERN
NORTH DAKOTA. SCATTERED THUNDERSTORMS ARE POSSIBLE ACROSS WEST AND
SOUTHERN NORTH DAKOTA AFTER 09Z...HOWEVER TO UNCERTAIN AS TO
TIMING TO MENTION IN THE TAFS AT THIS TIME.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1002 PM EDT SUN JUL 29 2012
.SYNOPSIS...
A CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS BEGINS ON MONDAY
AS AN UPPER DISTURBANCE WILL DROP SOUTHEAST ACROSS THE AREA. A
WEAK COLD FRONT WILL THEN PUSH THROUGH THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE OVER THE SOUTHERN GREAT
LAKES AND MIDDLE OHIO VALLEY REGIONS. NORTHWESTERLY FLOW ALOFT
WILL CONTINUE TO SPREAD IN A FEW MID AND HIGH CLOUDS...GRADUALLY
THICKENING SLIGHTLY GOING INTO TOMORROW. THE EARLIER ADJUSTMENTS
TO A DRY FORECAST STILL APPEAR TO BE THE BEST COURSE OF ACTION.
LOW TEMPS WERE ADJUSTED SLIGHTLY BASED PRIMARILY ON THE MET
NUMBERS (RECENT RAP RUNS LOOK WELL TOO WARM...GIVEN THAT IT IS
ALREADY IN THE UPPER 60S IN OUTLYING AREAS).
PREVIOUS DISCUSSION >
7PM UPDATE...MADE ONLY MINOR DEWPOINT AND CLOUD TWEAKS OVERNIGHT.
PREVIOUS DISCUSSION...EARLIER MODEL RUNS WERE PUSHING A WET SOLUTION
IN HANDLING APPROACHING WEAK S/WV PUSHING SSE ACROSS INDIANA
OVERNIGHT. UPDATED RUNS...INCLUDING THE HRRR/WRF/ECMWF
SOLUTIONS...THE DRY BOUNDARY LAYER AND NO STRONG FORCING MECHANISM
HAVE PROMPTED DECISION TO KEEP PRECIP OUT OF AREA AS A RESULT.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS THE SHORT WAVE DROPS THROUGH AREA ON MONDAY...AGAIN SOME
DIFFERENCES IN PRECIP PLACEMENT AND COVERAGE. HAVE KEPT ONLY A 20
POP ACROSS THE AREA DUE TO DRIER BOUNDARY LAYER ONLY WEAK FORCING
AND DIMINISHED COVERAGE AS A RESULT. GFS HAD BEEN VERY AGGRESSIVE
WITH THE PRECIP...BUT IS AGAIN HANDLING SURFACE DEWPOINTS
POORLY...SO HAVE NOT CONSIDERED THIS SOLUTION. 00Z ECMWF RUN HAD
ALSO BEEN MORE AGGRESSIVE WITH PRECIP BUT 12Z RUN CAME IN MORE
CONSERVATIVE...GIVING FURTHER SUPPORT FOR SLIGHT CUTS IN PRECIP
CHANCES.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
HAVE TAKEN A BLEND OF NCEP/HPC AND THE 00Z ECMWF FOR THE EXTENDED
FORECAST AS THEY OFFER THE BEST SOLUTION AND HAVE CONTINUITY.
A WEAK COLD FRONT IS FORECAST TO SLIDE INTO THE REGION ON TUESDAY
AND WITH A S/WV DROPPING DOWN IN THE NORTHWEST FLOW ALOFT...IT
APPEARS THAT THERE WILL BE A CHANCE OF SHOWERS/STORMS TUESDAY INTO
TUESDAY EVENING. IT STILL LOOKS LIKE A SURFACE RIDGE WILL THEN BUILD
INTO THE REGION BY WEDNESDAY NIGHT AND PERSIST ACRS THE AREA INTO
THURSDAY. UPR LVL FLOW BRIEFLY TRANSITIONS MORE TO A ZONAL PATTERN
ON FRIDAY...AND WITH WEAK RETURN SFC FLOW AROUND DEPARTING HIGH AND
PERHAPS AN EMBEDDED DISTURBANCE RIPPLING ALOFT...HAVE KEPT A LOW
CHANCE FOR SHOWERS/STORMS. A STRONGER S/WV AND COLD FRONT IS POISED
TO AFFECT THE REGION SATURDAY INTO SATURDAY NIGHT...OFFERING AN
ENHANCED CHANCE OF SHOWERS AND STORMS. THE COLD FRONT IS PROGGED TO
SLIDE SE OF THE AREA ON SUNDAY...BRING AN END TO THE PCPN AND
ALLOWING DRIER AIR TO BUILD BACK INTO THE AREA ONCE AGAIN.
TEMPERATURES ON A WHOLE SHOULD AVERAGE ABOVE NORMAL THROUGH THE
PERIOD. HOW FAR ABOVE NORMAL WILL DEPEND ON CLOUD COVER AND
PRECIPITATION COVERAGE.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. HIGH PRESSURE WILL
SLIDE OFF TO THE EAST TONIGHT. WATCHING A SUBTLE UPPER LEVEL
DISTURBANCE PRODUCING SHOWERS NEAR THE WI/ILL BORDER WHICH WILL
SLIDE SOUTHEAST TONIGHT. ANY PCPN WILL LIKELY DISSIPATE OR AT LEAST
REMAIN WEST OF THE AREA...BUT MID LEVEL CLOUDS WILL SPREAD IN AND
LINGER THROUGH MUCH OF MONDAY. THESE CLOUDS...ALONG WITH DRIER
ATMOSPHERE...SHOULD PREVENT FOG FORMATION TONIGHT. SOME CU IS
EXPECTED TO DEVELOP IN THE DAYTIME HEATING ON MONDAY. WITH LOW
PRESSURE OVER THE LOWER OHIO VALLEY AND AN UPPER LEVEL DISTURBANCE
NEARBY...IT IS NOT OUT OF THE QUESTION FOR SOME ISOLATED
SHOWERS/STORMS TO DEVELOP ON MONDAY...BUT PROBABILITY OF AFFECTING
A TERMINAL IS LOW ENOUGH TO NOT INCLUDE IN THE TAFS. WINDS WILL
REMAIN LIGHT WITH A GENERAL SOUTHEAST COMPONENT.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR/HATZOS
SHORT TERM...JDR
LONG TERM...HICKMAN
AVIATION...SNYDER
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
349 PM EDT SAT JUL 28 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE REGION FROM THE
NORTHWEST...PROVIDING DRY CONDITIONS FOR THE WEEKEND. TEMPERATURES
WILL WARM EARLY IN THE WEEK...WITH LOW PRESSURE BRINGING A CHANCE
OF PRECIPITATION MONDAY AND TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
PRIMARY CONCERN FOR THE NEAR TERM IS THE CHANCE OF SHOWERS IN THE
EASTERN HALF OF THE CWA OVER THE NEXT FEW HOURS. A WEAK FRONT HAS
MOVED THROUGH MOST OF THE CWA...SWITCHING WINDS TO THE NORTH AND
BRINGING GUSTS UP TO THE 15-20 KNOT RANGE IN SOME LOCATIONS.
NEBULOUS SURFACE LOW PRESSURE OVER WESTERN PENNSYLVANIA WILL MOVE
FURTHER AWAY...AS A MID LEVEL SHORTWAVE HEADS SOUTHEAST INTO THE
MID-ATLANTIC. FORCING FOR SHOWERS (AND THE SLIM CHANCE OF A FEW
RUMBLES) WILL THUS BE LARGELY DIMINISHING OVER THE CWA THROUGH THE
EVENING HOURS...WHICH SHOULD COMBINE WITH THE DIURNAL CYCLE TO
ALLOW FOR A GRADUAL DIMINISHING IN POPS THROUGH AND JUST AFTER
00Z. HIGH-RES MODELS (RECENT HRRR RUNS FOR EXAMPLE) SHOW SOME
ENHANCEMENT CLOSER TO 00Z...AND A BIT MORE WESTWARD OF ACTIVITY
THAN THE FORECAST WILL INDICATE.
WITH LIGHT WINDS AND CLEAR SKIES...THERE DOES APPEAR TO BE SOME
FOG POTENTIAL OVERNIGHT. BOUNDARY LAYER MOISTURE IS NOT ESPECIALLY
HIGH...BUT SHOULD BE HIGH ENOUGH TO AT LEAST PROMOTE FOG IN THE
VALLEYS AND LOW LOCATIONS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
HIGH PRESSURE WILL EXTEND FROM THE GREAT LAKES INTO THE OHIO
VALLEY ON SUNDAY...PLACING THE CWA IN AN AREA OF WEAK WIND FLOW.
THE AIR MASS WILL NOT BE SUBSTANTIALLY DIFFERENT FROM THE ONE OVER
THE REGION TODAY...THOUGH SLIGHTLY DRIER. WITH A DECENT BIT MORE
SUN EXPECTED THAN TODAY...WILL CONTINUE WITH A TEMPERATURE
FORECAST ABOUT 5-7 DEGREES WARMER THAN TODAY.
MOST OF THE MODELS ARE IN AGREEMENT ON A WEAK AREA OF LOW PRESSURE
MOVING FROM THE MIDDLE MISSISSIPPI VALLEY INTO THE SOUTH ON MONDAY
AND INTO MONDAY NIGHT. THE 12Z GFS IS ADVERTISING AN UNSUPPORTED
SOLUTION WITH A SURFACE LOW MOVING THROUGH THE SOUTHERN GREAT
LAKES INSTEAD. WILL SIDE WITH THE CONSENSUS (WHICH INCLUDES THE
06Z GFS) AND KEEP THE FORECAST IMPACTS FOR MONDAY LESS
SUBSTANTIAL. BUILDING INSTABILITY WITH WEAK FORCING WILL SUPPORT
CHANCE POPS IN THE FAR SOUTHWEST...AND SLIGHT CHANCE FOR ABOUT THE
REST OF THE SOUTHWESTERN HALF OF THE CWA.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
HAVE TAKEN A BLEND OF NCEP/HPC AND THE 00Z ECMWF FOR THE EXTENDED
FORECAST AS THEY OFFER THE BEST SOLUTION AND HAVE CONTINUITY.
A WEAK BOUNDARY IS FORECAST TO SLIDE INTO THE REGION AND WITH
DISTURBANCES DROPPING DOWN IN NORTHWEST FLOW...IT APPEARS THAT THERE
WILL BE AN ENHANCED CHANCE OF PRECIPITATION TUESDAY INTO TUESDAY
NIGHT. THAT MAY LINGER INTO WEDNESDAY ALTHOUGH THERE IS MORE
UNCERTAINTY BY THAT TIME. LOOKS LIKE A SURFACE RIDGE WILL MOVE IN
FOR THURSDAY. BUT THERE IS MODEST AGREEMENT IN THE MODELS THAT A
MORE ROBUST SHORT WAVE WILL MOVE INTO THE AREA THURSDAY NIGHT AND
FRIDAY WHICH WOULD BRING ANOTHER CHANCE OF SHOWERS AND
THUNDERSTORMS. THIS FEATURE WILL PASS BY TO THE EAST FRIDAY NIGHT
AND SATURDAY WITH PERHAPS A WEAK SFC BOUNDARY LINGERING ACROSS THE
SRN ZONES ON SATURDAY.
TEMPERATURES ON A WHOLE SHOULD AVERAGE ABOVE NORMAL THROUGH THE
PERIOD. HOW FAR ABOVE NORMAL WILL DEPEND ON CLOUD COVER AND
PRECIPITATION COVERAGE.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
DID NOT CHANGE MUCH WITH THE FORECAST TODAY. CLEARED OUT THE CU
FIELD QUICKLY THIS EVENING. NORTH WINDS UNDER 5KT WILL HELP LIMIT
ANY BR TO MAINLY OCCUR WITH THE COOLEST PERIOD OF THE OVERNIGHT
9-12Z AND MAINLY BE MVFR. EXCEPTION HERE IS KLUK WHERE THE COLD
POOL WILL PROBABLY SOCK THEM IN WITH A LOW CIG AND NEAR ZERO VSBYS.
CU FIELD WILL BE A GOOD BIT LESS TOMORROW AS THE AIRMASS MODIFIES
AND SOME H8 HEATING IS EXPECTED THROUGH THE DAY. VARIABLE WINDS
WILL WORK IN LATE IN THE PERIOD AS THE SURFACE HIGH MAINTAINS A
CLOSE IF NOT NEBULOUS PROXIMITY TO THE REGION.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE MONDAY THROUGH WEDNESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HATZOS
NEAR TERM...HATZOS
SHORT TERM...HATZOS
LONG TERM...HICKMAN
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1033 AM PDT Sat Jul 28 2012
.SYNOPSIS...
A trough of low pressure off the coast will keep a southwest to
northeast oriented storm track in the vicinity of Eastern
Washington and North Idaho into next week. This pattern should
result in near normal temperatures through around mid week. A cooler
and more showery weather pattern may develop late next week as the
offshore low moves inland.
&&
.DISCUSSION...
Morning Update: We have removed thunderstorm chances over the Blue
Mtns and Camas Prairie for this afternoon. Drier W flow in the
wake of last night`s shortwave passage has brought surface
dewpoints down into the 30`s to low 40`s Fahrenheit. Forecast
soundings plotted over these locations via the NAM/GFS strongly
agree that the CIN (convective inhibition) will be overwhelming
this afternoon and local HRRR is in strong agreement. Otherwise,
the forecast is on track with sunny skies and seasonal
temperatures expected region-wide with the exception of fair
cumulus fields speckled across the northern mountains. /sb
&&
.AVIATION...
18Z TAFS...Weak high pressure will promote mainly clear and dry
conditions at TAF sites, with VFR conditions, and light winds.
/sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 83 58 86 61 87 61 / 0 0 0 10 0 0
Coeur d`Alene 82 53 84 56 85 56 / 0 0 0 10 10 0
Pullman 82 52 84 54 85 54 / 0 0 0 10 10 10
Lewiston 91 62 93 65 93 63 / 0 0 10 10 10 10
Colville 86 55 88 56 91 55 / 0 0 0 10 10 10
Sandpoint 84 47 82 50 83 52 / 0 0 0 10 10 10
Kellogg 81 51 84 54 85 54 / 0 0 0 10 10 10
Moses Lake 86 59 89 60 90 58 / 0 0 0 0 0 0
Wenatchee 87 63 89 63 90 62 / 0 0 0 0 0 0
Omak 88 58 90 58 91 58 / 0 0 0 0 0 0
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1158 AM CDT SAT JUL 28 2012
.UPDATE...
AREA OF SHOWERS/STORMS OVER IOWA ASSOCIATED WITH MESOSCALE SHORTWAVE
SHOULD CONTINUE TO MOVE SOUTHEAST AS WAVE TRAVELS AROUND MID-UPPER
LEVEL RIDGE OVER SOUTHERN PLAINS. EARLIER HRRR RUN BROUGHT THE
PRECIP INTO THE SOUTHWEST CWA LATE THIS AFTERNOON...BUT IT WAS THE
OUTLIER AMONG THE SHORT TERM MODELS AND THE 13Z RUN KEEPS US DRY.
THE SOUTHWEST WILL SEE SOME CIRRUS FROM THE SYSTEM THOUGH. UPDATED
SKY TRENDS FOR THIS.
PREVIOUSLY FORECAST TEMPERATURES WERE GENERALLY ON TRACK BUT
SLIGHTLY REVISED AFTERNOON TRENDS BASED ON CHANGES TO SKY COVER AND
MID MORNING READINGS. LAKE BREEZE SCOURING AWAY CU NEAR THE LAKE AS
EXPECTED...AND WITH THE BREEZE TEMPERATURES SHOULD NOT CLIMB MUCH
MORE.
&&
.AVIATION/18Z TAFS/...
VFR CUMULUS WILL PERSIST THROUGH MUCH OF THE TODAY...DIMINISHING
LATE AFTERNOON AND EVENING. MID AND HIGH LEVEL CLOUDS WILL THEN
SLOWLY INCREASE FROM THE WEST OVERNIGHT. WITH HIGH PRESSURE SLIDING
TO THE EAST AND MORE CLOUDS EXPECTED...SHOULD SEE LESS AREAS OF
BR/FG THAN LAST NIGHT. BEST CHANCE FOR LOWER VSBYS WILL BE IN THE
EAST WHERE IT WILL LIKELY STAY MOSTLY CLEAR THROUGH MUCH OF THE
NIGHT.
PRECIP CHANCES FOR TOMORROW EXPECTED TO STAY SOUTHWEST OF
MADISON...WITH VFR CONDITIONS ACROSS THE AREA THROUGH THE DAY.
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT JUL 28 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
A NELY FETCH OFF LAKE MI AND WATER TO 850 MB TEMP DIFFERENCES OF
11-12C HAS RESULTED IN SCT-BKN STRATUS CLOUDS WITH EVEN A FEW
SHOWERS LAST NIGHT. SATELLITE TRENDS ARE SHOWING LESS CLOUDS AND
WILL COUNT ON NO MORE SHOWER ACTIVITY EARLY THIS AM. OTHERWISE
HIGH PRESSURE AND A LAKE BREEZE WILL BE THE MAIN WX FEATURES
TODAY. SCT-BKN CUMULUS WILL OCCUR ONCE AGAIN BUT WITHOUT THE
SHOWERS. 925-850 MB TEMPS SUGGEST SFC TEMPS IN THE LOWER 80S WITH
SLIGHTLY COOLER TEMPS NEAR THE LAKE.
FOR TNT...HIGH PRESSURE WILL GRADUALLY MOVE EWD BUT WINDS WILL
REMAIN VERY LIGHT WITH PATCHY FOG POSSIBLE LATE IN FAVORED AREAS.
EXPECT SOME INCREASE IN CLOUDS MAINLY IN THE WRN CWA LATE TNT AS A
WEAK VORTICITY MAXIMUM MOVES ACROSS IA AND THE ERN EXTENT OF A MID
LEVEL WARM ADVECTION ZONE AFFECTS SW WI. SLIGHT CHANCE FOR TSTORMS
FOR THE FAR SW CWA LATE.
SHORT TERM...SUNDAY THROUGH MONDAY NIGHT...FORECAST CONFIDENCE IS
MEDIUM.
NORTHWEST FLOW IN THE MID TO UPPER LEVELS LINGERS ACROSS THE
REGION DURING THIS TIME. NAM/ECMWF/CANADIAN AND GFS DIFFER WITH
TRENDS DURING THIS PERIOD. NAM/ECMWF/CANADIAN MODELS KEEP THE AREA
DRY SUNDAY...WITH LOW LEVEL JET NOSE REMAINING WEST OF THE AREA.
GFS BRINGS LIGHT QPF THROUGH THE AREA MAINLY SUNDAY AFTERNOON...AS
LOW LEVEL JET NOSE POINTS INTO THE AREA FROM THE SOUTHWEST.
ALL MODELS DO SHOW MODEST WARM AIR ADVECTION AND VARIOUS WEAK
VORTICITY MAXIMA SHIFTING THROUGH THE AREA. NAM FORECAST SOUNDINGS
QUITE DRY...WITH GFS SOUNDINGS SHOWING MORE LOW LEVEL
MOISTURE...THOUGH LIKELY A RESULT OF HIGH BIAS WITH DEWPOINTS AND
LOW LEVEL MOISTURE.
FOR NOW...WILL LEAVE SLIGHT CHANCE POPS GOING IN JUST THE FAR
SOUTHWEST COUNTIES. TEMPERATURES SHOULD RISE ABOVE NORMAL AWAY
FROM LAKE MICHIGAN...WITH NAM 925MB TEMPERATURES IN THE MID 20S
CELSIUS RANGE. ONSHORE WINDS WILL KEEP NEAR NORMAL TEMPERATURES
NEAR THE SHORE.
NOT SEEING MUCH IN THE WAY OF UPWARD VERTICAL MOTION POTENTIAL
SUNDAY NIGHT...WITH JUST SOME WEAK VORTICITY MAXIMA SHIFTING
THROUGH THE REGION. GFS ONLY MODEL WITH LIGHT QPF IN THE
AREA...AGAIN LIKELY OVERDONE DUE TO HIGH MOISTURE BIAS. WENT DRY
FOR SUNDAY NIGHT.
MODELS BRING MORE WARM AIR ADVECTION INTO THE AREA FOR
MONDAY...ALONG WITH DECENT VORTICITY MAXIMA PASSING THROUGH THE
AREA PER NAM/GFS. HIGHER DEWPOINTS IN THE LOWER TO MID 60S ARE
EXPECTED...WHICH SHOULD BRING IN MORE INSTABILITY. CAP IN 850MB
TO 700MB LAYER MAY LIMIT AREAL COVERAGE OF SHOWERS AND STORMS. FOR
NOW...WILL KEEP SLIGHT CHANCE POPS GOING FOR MONDAY...MAINLY IN
THE NORTHERN COUNTIES.
HIGHS COULD GET VERY WARM IF CLOUDS ARE NOT TOO WIDESPREAD. 925MB
TEMPERATURES FROM NAM SUGGEST HIGHS WELL INTO THE 90S AWAY FROM
THE LAKE. WILL GO SOMEWHAT LOWER WITH HIGHS GIVEN THE POSSIBILITY
FOR SOME MID LEVEL CLOUDS.
KEPT POPS GOING MONDAY NIGHT...AS MODELS BRING COLD FRONT
SOUTHEAST INTO OR THROUGH THE FORECAST AREA. MODEST SHORTWAVE
TROUGH DROPPING SOUTHEAST INTO THE AREA LATE MONDAY NIGHT WOULD
HELP WITH UPWARD VERTICAL MOTION. NAM FORECAST SOUNDINGS SUGGEST A
FAIRLY STRONG CAP MONDAY NIGHT...SO THAT WOULD BE A LIMITING
FACTOR.
LONG TERM...TUESDAY THROUGH FRIDAY...FORECAST CONFIDENCE IS
MEDIUM.
GFS/ECMWF SHOWING NORTHWEST FLOW IN THE MID TO UPPER LEVELS
LINGERING ACROSS THE REGION FOR MOST OF THIS PERIOD...EVENTUALLY
BECOMING MORE ZONAL BY LATE FRIDAY INTO NEXT WEEKEND.
COLD FRONT/MODEST SHORTWAVE PUSHES THROUGH THE AREA TUESDAY
MORNING...WITH HIGH PRESSURE PUSHING INTO THE AREA DURING THE
AFTERNOON. LOW POPS WILL BE KEPT FOR TUESDAY IN THE EASTERN
COUNTIES...WITH WARM TEMPERATURES LINGERING.
HIGH PRESSURE THEN SLIDES SOUTHEAST THROUGH THE AREA TUESDAY
NIGHT INTO WEDNESDAY...BRINGING QUIET WEATHER AND CONTINUED WARM
TEMPERATURES. SLIGHT CHANCES FOR PRECIPITATION WEDNESDAY IN THE
FAR NORTHWEST COUNTIES WITH COLD FRONTAL APPROACH.
ECMWF/GFS BRINGING ANOTHER COLD FRONT SOUTHEAST THROUGH THE AREA
WEDNESDAY NIGHT INTO THURSDAY. GFS HAS BETTER SHORTWAVE TROUGH
SLIDING THROUGH THE AREA...WITH THE ECMWF TO THE NORTHEAST OF THE
AREA. DECENT VORTICITY MAXIMUM THEN SLIDES EAST INTO THE AREA
FRIDAY FOR ANOTHER SHOT OF PRECIPITATION. KEPT GENERALLY LOW END
POPS AT TIMES DURING THIS PERIOD. TEMPERATURES SHOULD BE NEAR
SEASONAL NORMALS.
AVIATION/12Z TAFS/...
SCT LAKE EFFECT STRATUS CLOUDS WILL DISSIPATE BY MID MORNING WITH
A LAKE BREEZE TO THEN PREVAIL OVER FAR ERN WI. OTHERWISE HIGH
PRESSURE AND SCT-BKN CUMULUS CLOUDS AT 4-5 KFT WILL DEVELOP FROM
LATE MORNING THROUGH THE AFTERNOON AWAY FROM THE LAKE. CUMULUS TO
DISSIPATE QUICKLY EARLY THIS EVENING WITH SCT MID TO HIGH CLOUDS
INCREASING FROM WEST TO EAST ACROSS SRN WI THROUGHOUT THE NIGHT.
THE CLOUDS WILL BE THIN HOWEVER AND PATCHY FOG MAY DEVELOP IN LOW
LYING AREAS LATE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
SUNDAY THROUGH FRIDAY...WOOD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
259 AM CDT SAT JUL 28 2012
.SHORT TERM...TODAY THROUGH MONDAY NIGHT
259 AM CDT SAT JUL 28 2012
THE MAIN FOCUS THROUGH THE WEEKEND AND EARLY NEXT WEEK IS WITH THE
PRECIPITATION CHANCES AS A PAIR OF STORM SYSTEMS MOVE THROUGH THE
REGION.
THE CORE OF A SURFACE RIDGE OF HIGH PRESSURE CONTINUES TO DRIFT TO
THE EAST WITH A WEAK SURFACE TROUGH RUNNING NORTHWEST ALONG THE
MISSISSIPPI RIVER. SKIES HAVE MAINLY CLEARED OUT WITH SOME MID
LEVEL BASED CU LINGERING ALONG THE SURFACE TROUGH AND HIGH LEVEL
CLOUD COVER STARTING TO MOVE IN FROM THE WEST OFF OF CONVECTION IN
THE DAKOTAS. SOME SHALLOW GROUND/VALLEY FOG HAS FORMED THIS
MORNING BUT SURFACE DEW POINT DEPRESSIONS REMAIN A FEW DEGREES OFF
ELSEWHERE AND HAS NOT ALLOWED FOR WIDESPREAD FOG FORMATION.
THE DAKOTAS CONVECTION HAS FORMED AS A MID LEVEL SHORT WAVE TROUGH
ROUNDS THE NORTHERN PERIPHERY OF THE FLAT MID LEVEL RIDGE IN THE
SOUTHERN PLAINS/ROCKIES. THIS CONVECTION HAS ALSO BEEN FUELED BY
850MB WARM AIR ADVECTION...ISENTROPIC LIFT ON THE 315K SURFACE AND
A CORRIDOR OF 2000 J/KG 0-3KM MUCAPE THAT NOSES UP INTO THE
CONVECTION. THESE FEATURES WILL BE THE MAIN FORCING FEATURES FOR
OUR REGION AS THE SYSTEM MOVES EAST THIS WEEKEND.
THE MID LEVEL SHORT WAVE TROUGH DIVES SOUTHEAST THROUGH THE
NORTHWEST FLOW TODAY WITH THE LOW LEVEL FORCING SLOWLY DRIFTING
EAST INTO IOWA. THIS SHOULD TAKE THE ONGOING CONVECTION IN
SOUTHERN SOUTH DAKOTA TO THE SOUTHEAST TOWARD CENTRAL IOWA TODAY
AS A SURFACE LOW MOVES ACROSS NEBRASKA. THROUGH 00Z...IT APPEARS
THAT MUCH OF THE LOW LEVEL FORCING FROM THE 850MB WAA AND
ISENTROPIC LIFT STAYS MAINLY IN IOWA AND SOUTHERN MINNESOTA...SO
HAVE KEPT THE CHANCES TO THIS REGION. LITTLE TO NO 0-3KM MUCAPE
COMES IN DURING THIS TIME FRAME...SO HAVE KEPT ANY THUNDER MENTION
ISOLATED. THESE TRENDS CONTINUE INTO THE OVERNIGHT HOURS AS THE
FORCING AIMS TO THE EAST A BIT MORE CLOSER TOWARD THE MISSISSIPPI
RIVER WITH MUCAPE REMAINING LOW AT LESS THAN 500 J/KG. THE NOSE OF
THE 925-850MB MOISTURE TRANSPORT PROPAGATES SOUTHEAST ACROSS
CENTRAL IOWA TONIGHT AND DOES NOT PUSH TOO FAR NORTHEAST INTO THE
FORECAST AREA GOING INTO SUNDAY. WITH THE BEST FORCING REMAINING
IN SOUTHERN MINNESOTA/IOWA TODAY INTO TOMORROW...HAVE KEPT THE
BEST CHANCES FOR PRECIPITATION ACROSS THIS REGION. MUCH LESS
CONFIDENT IN THE CHANCES GOING EAST OF THE MISSISSIPPI AS THE
FORCING BECOMES MORE BROAD AND THERE BEING MUCH LESS INSTABILITY
TO WORK WITH. TEMPERATURES TODAY WILL BE DEPENDENT ON HOW MUCH
CLOUD COVER MOVES IN AND HOW FAST. WITH HIGH LEVEL CLOUD COVER
TO THE RIVER BY EARLY AFTERNOON...LOCATIONS WEST OF IT WILL SEE
LOWER MAX TEMPERATURES IN THE UPPER 70S TODAY.
SOME DIFFERENCES ARISE BETWEEN THE 28.00Z NAM/GEM AND 28.00Z GFS
FOR SUNDAY WITH THE NAM/GEM TAKING THE PRECIPITATION TO THE
SOUTHEAST TOWARD WESTERN ILLINOIS ALONG THE NOSE OF THE LOW LEVEL
MOISTURE TRANSPORT WHILE THE GFS LINGERS PRECIPITATION AROUND
THROUGH THE DAY WITH A DEEPER 850MB LOW SITTING OVER THE REGION.
HAVE TRENDED SUNDAY MORE ON THE DRY SIDE...BUT HAVE LEFT THE
CHANCES GOING IN NORTHEAST IOWA/SOUTHWEST WISCONSIN FOR ANY
LEFTOVER SHOWERS THAT COULD BE LINGERING FROM THE SOUTHERN SYSTEM.
A SURFACE RIDGE AXIS WILL THEN HELP TO DRY THINGS OUT SUNDAY NIGHT
AS THE NEXT SYSTEM TRACKS ACROSS THE NORTHERN PLAINS/SOUTHERN
CANADA. THIS SYSTEM WILL BRING A SURFACE COLD FRONT THROUGH THE
REGION MONDAY INTO MONDAY NIGHT. SOME CONSIDERABLE TIMING
DIFFERENCES ON WHEN THE FRONT MAKES IT IN SHOW UP BETWEEN THE
28.00Z NAM/GFS/ECMWF WITH THE NAM BEING THE FASTEST IN BRINGING IT
THROUGH DURING THE AFTERNOON MONDAY. THE NAM IS ALSO ON THE HIGH
SIDE WITH TEMPERATURE ADVECTION AND IS THE WARMEST WITH ITS HIGHS
FOR MONDAY IN THE UPPER 90S. MONDAY DOES APPEAR TO BE THE WARMEST
DAY OF THE NEXT WEEK...THOUGH LOW 90S SEEM TO BE MORE LIKELY THAN
NEAR RECORD HIGHS. WHILE INSTABILITY DOES BUILD ALONG/AHEAD OF
THE FRONT...THE BETTER LOW TO MID LEVEL LIFT STAYS NORTH CLOSER TO
THE MID LEVEL TROUGH TO THE NORTH. THEREFORE...HAVE GONE A LITTLE
MORE CONSERVATIVE ON THE PRECIPITATION CHANCES MONDAY/MONDAY NIGHT
WITH THE BEST CHANCES IN NORTH CENTRAL WISCONSIN.
.LONG TERM...TUESDAY THROUGH FRIDAY
259 AM CDT SAT JUL 28 2012
WITH THE COLD FRONT CLEAR OF THE REGION ON TUESDAY...HIGH PRESSURE
WILL SETTLE IN ACROSS THE UPPER MISSISSIPPI RIVER VALLEY REGION
AND PROVIDE A DRY TUESDAY AND TUESDAY NIGHT. THE UPPER LEVEL RIDGE
REMAINS IN PLACE THROUGHOUT THE WEEK ALONG THE WESTERN
PLAINS/ROCKIES WITH WEAK TROUGHING ALONG THE EAST COAST. THE NEXT
MID LEVEL SHORT WAVE TROUGH APPEARS TO EJECT OUT OF THE CANADIAN
ROCKIES MID WEEK. THIS TROUGH AND SURFACE COLD FRONT SHOULD MOVE
INTO THE REGION LATE WEDNESDAY AFTERNOON AND EVENING AND BRING THE
NEXT CHANCE FOR PRECIPITATION ALONG WITH IT. NOT MUCH IN THE WAY
OF LOW LEVEL WARM AIR ADVECTION THROUGH THE WEEK...SO AM EXPECTING
MAINLY SEASONAL OR SLIGHTLY WARMER THAN NORMAL TEMPERATURES
THROUGH NEXT WEEK.
&&
.AVIATION...THROUGH 06Z SUNDAY
1150 PM CDT FRI JUL 27 2012
MAIN NEAR TERM CONCERN CONTINUES ON FOG POTENTIAL. 04Z
OBSERVATIONS SHOWS 6 DEGREE TEMPERATURE/DEW POINT SPREAD AT KLSE
AND 7 DEGREES AT KRST. HIGH PRESSURE WAS CENTERED OVER MINNESOTA
AND NORTHERN WISCONSIN AND WILL SETTLE OVER THE AREA. CLOUDS HAVE
CLEARED AT BOTH TAF SITES AND BOTH THE NAM AND RAP SOUNDINGS SHOW
DEEP LAYER LIGHT WINDS. 28.03Z RAP CONTINUES TO SHOW A 2 TO 3
DEGREE CELSIUS TEMPERATURE/DEW POINT SPREAD LATE TONIGHT...WHILE
NAM IS MORE SATURATED. WITH THESE FAVORABLE CONDITIONS DID
CONTINUE THE MENTION OF FOG AT BOTH SITES...BUT NOT QUITE AS LOW
AT KRST. VFR CONDITIONS THEN EXPECTED THROUGH THE REMAINDER OF THE
FORECAST PERIOD. DID ADD MENTION OF VCSH AT KRST AFTER 03Z
SUNDAY AHEAD OF THE NEXT WAVE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
259 AM CDT SAT JUL 28 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1108 PM CDT FRI JUL 27 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT THROUGH SATURDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COMPACT UPPER
SHORTWAVE MOVING EAST OVER NORTHERN LAKE MICHIGAN EARLY THIS
AFTERNOON. SCATTERED TO NUMEROUS SHOWER ACTIVITY CONTINUES TO
DEVELOP AND ROTATE AROUND THE SHORTWAVE ACROSS MUCH OF NORTHEAST AND
CENTRAL WISCONSIN. NORTH-CENTRAL WISCONSIN HAS BEEN THE LONE DRY
SPOT TODAY AND CLEARING IS BEGINNING TO WORK INTO VILAS COUNTY FROM
THE NORTH. HIGH PRESSURE RESIDES OVER THE NORTHERN MISSISSIPPI
VALLEY AND THE DAKOTAS WHERE MOSTLY CLEAR TO PARTLY CLOUDY
CONDITIONS ARE OCCURRING. THE MAIN FORECAST CONCERNS ARE TIMING THE
END OF THE SHOWER ACTIVITY AND FOG/TEMPS.
TONIGHT...THE SHORTWAVE TROUGH WILL MOVE TO THE EASTERN GREAT LAKES
TONIGHT WHILE HIGH PRESSURE BUILDS INTO THE REGION IN ITS WAKE.
PLENTY OF LOW LEVEL MOISTURE UPSTREAM ALL THE WAY WEST TO MINNESOTA
AND DRY AIR ADVECTION IS WEAK...SO IT MAY TAKE AWHILE FOR CLOUDS TO
CLEAR. SHOULD SEE THE CLEARING WORK FROM NW TO SE THROUGH THE NIGHT
THOUGH. HAVE INCREASED SKY COVER THIS EVENING BUT STILL TAKE SKY
CONDITIONS MOSTLY CLEAR OVERNIGHT. AFTER SEVERAL ROUND OF RAINFALL
THE PAST FEW DAYS...MOIST SOIL CONDITIONS WILL BE SUPPORTIVE FOR FOG
OVERNIGHT. WILL ADD AREAS OF DENSE FOG TO THE FORECAST FOR
NORTH-CENTRAL WISCONSIN. LOWS RANGING FROM THE UPPER 40S NORTH TO
AROUND 60 SOUTH.
SATURDAY...HIGH PRESSURE WILL BE OVER THE AREA AND WILL LEAD TO DRY
CONDITIONS. THE 12Z NAM IS MORE BULLISH IN KEEPING THE LOW LEVEL
MOISTURE AROUND FOR TOMORROW...WHICH SHOULD LEAD TO A DECENT CU
FIELD DEVELOPING BY LATE MORNING. UPSTREAM OBS SUPPORT THIS OVER
MINNESOTA SO WILL PORTRAY PARTLY CLOUDY CONDITIONS FOR THE
AFTERNOON. HIGHS WILL BE SEASONABLE AROUND THE UPPER 70S TO LOWER
80S.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
THE PRIMARY CONCERNS DURING THIS PART OF THE FORECAST ARE TIMING OF
UPPER LEVEL SHORT WAVES AND ASSOCIATED PRECIPITATION CHANCES.
A CLOSED 500MB LOW IN THE VICINITY OF HUDSON BAY AND A WEAK RIDGE
OVER THE CENTRAL/WESTERN CONUS WILL KEEP THE REGION IN WEST-
NORTHWEST FLOW ALOFT. MEDIUM RANGE MODELS WERE NOT IN THE BEST OF
AGREEMENT...BUT DID HAVE SOME QPF FORECAST IN/AROUND THE AREA
SATURDAY NIGHT AND SUNDAY. SHORT WAVE ENERGY AND A WEAK SURFACE
BOUNDARY MOVING INTO WISCONSIN FROM THE NORTH WILL BRING A CHANCE
OF SHOWERS AND THUNDERSTORMS ON TUESDAY. SURFACE HIGH PRESSURE
SHOULD KEEP TUESDAY NIGHT DRY BEFORE MODELS BRING THE NEXT SHORT
WAVE AND SURFACE BOUNDARY INTO THE FORECAST AREA...KEEPING A
CHANCE OF SHOWERS AND STORMS AROUND THROUGH THURSDAY. SURFACE HIGH
PRESSURE BUILDING IN BEHIND THE DEPARTING FRONT SHOULD KEEP
FRIDAY DRY.
DO NOT REALLY SEE A REASON FOR TEMPERATURES TO WARM INTO THE 90S
IN THE NEAR FUTURE. LOOKS LIKE READINGS SHOULD BE CLOSER TO
SEASONAL NORMALS.
&&
.AVIATION...POSSIBLITY FOR PATCHY/AREAS OF DENSE FOG EXISTS FOR
THE OVERNIGHT PERIOD...PARTICULARLY ACROSS NORTH CENTRAL
WISCONSIN. ALSO COULD BE SOME PATCHY DENSE FOG OVER PARTS OF THE
FOX VALLEY...PARTICULARLY IN AREAS WHERE SUBSTANTIAL RAINFALL HAS
FALLEN OVER THE PAST 48 HOURS.
SCT-BKN VFR CIGS EXPECTED TO DEVELOP AROUND MID-DAY SATURDAY AS
RESIDUAL BOUNDARY LAYER MOISTURE FROM RECENT RAINS WILL LINGER.
WINDS EXPECTED TO BE LIGHT AND VARIABLE THROUGH MID-DAY AS HIGH
PRESSURE DRIFTS ACROSS THE AREA. THERE IS SOME INDICATION FROM
HIGHER RESOLUTION MODELS OF ONSHORE SOUTHEAST FLOW DEVLOPING
AND PERHAPS PENETRATING AS FAR WEST AS GRB...ATW AND OSH BY LATE
AFTERNOON.
EB
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PUEBLO CO
1135 PM MDT SUN JUL 29 2012
.UPDATE...
UPDATED TO INCREASE WINDS THROUGH AROUND 09Z TONIGHT. NORTH FLOW
CONTINUES TO BE ENHANCED BY AN MCV OVER NORTHEAST COLORADO AND
OUTFLOW WINDS FROM THUNDERSTORMS EARLIER. GUSTS TO 40 KTS WILL
CONTINUE OVER THE NEXT COUPLE OF HOURS AND DECREASE THROUGH 09Z.
LATEST RADAR TRENDS HAVE INDICATED ISOLATED THUNDERSTORMS NEAR
TRINIDAD AND WEST OF PUEBLO...SO ADDED THE MENTION OF ISOLATED
THUNDERSTORMS FOR THESE AREAS THROUGH THE NEXT HOUR OR SO. MOZLEY
&&
.PREV DISCUSSION... /ISSUED 1106 PM MDT SUN JUL 29 2012/
AVIATION...
ISOLATED THUNDERSTORMS CONTINUE OVER THE MOUNTAINS OVERNIGHT BUT
SHOULD NOT IMPACT THE TERMINALS. NORTH WINDS HAVE BEEN GUSTY AT
KCOS AND KPUB...WITH GUSTS APPROACHING 35-40 KTS. THESE WINDS WILL
CONTINUE THROUGH 09Z TONIGHT WITH LIGHTER WINDS THROUGH THE
MORNING. THUNDERSTORMS ARE FORECAST TO REDEVELOP OVER THE
MOUNTAINS AND SPREAD EAST ACROSS THE TERMINALS DURING THE LATE
AFTERNOON HOURS. GUSTY OUTFLOW WINDS WILL BE THE MAIN THREAT.
88
PREV DISCUSSION... /ISSUED 927 PM MDT SUN JUL 29 2012/
UPDATE...
UPDATED TO REMOVE POPS FOR THE PLAINS FOR THE REST OF TONIGHT. AN
OUTFLOW BOUNDARY HAS SHIFTED SOUTH ACROSS THE PLAINS WHICH HAS
HELPED STABILIZE THE PLAINS. ISOLATED SHOWER AND THUNDERSTORM
ACTIVITY WILL CONTINUE OVER THE MOUNTAIN REGIONS...ESPECIALLY THE
CONTINENTAL DIVIDE AREA. NO OTHER CHANGES AT THIS TIME. 88
PREV DISCUSSION... /ISSUED 355 PM MDT SUN JUL 29 2012/
SHORT TERM...
(TONIGHT AND MONDAY)
WATER VAPOR LOOPS TODAY CONTINUE TO SHOW DRY AIR PUNCHING IN UNDER
THE RIDGE ACROSS NM/SRN CO. LATEST AMSU SSM/I PRECIP WATER SAT PICS
ALSO SHOWING VALUES DROPPING OFF TO THE SOUTH...BUT STILL AN AXIS OF
HIGH PRECIP WATERS EXTENDING ACROSS NW CO. A COUPLE SHORTWAVES
EVIDENT IN WV PICS ACROSS UT/NW CO. MAIN FORCING FROM THESE MAY END
UP STAYING JUST TO THE NORTH OF THE FORECAST...BUT STILL ENOUGH
MOISTURE PRESENT WITHIN MONSOON PLUME ALOFT FOR SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS. GREATEST
COVERAGE WILL BE ACROSS CHAFFEE AND LAKE COUNTIES...AND POSSIBLY
TELLER...THOUGH EACH SUCCESSIVE HRRR RUN SEEMS TO SHIFT
AXIS OF HIGHER QPF TO THE NORTH ACROSS PARK COUNTY. WITH PRECIP
WATERS STILL AVERAGING AROUND OR SLIGHTLY BETTER THAN 100 PERCENT OF
NORMAL ACROSS THE SOUTHEAST MTS/ADJACENT PLAINS...LOCALLY HEAVY RAIN
WILL STILL BE A THREAT...PARTICULARLY FOR THE WALDO CANYON BURN SCAR
WHERE SOILS ARE SUSCEPTIBLE TO FLASH FLOODING WITH EVEN MINOR
AMOUNTS OF RAINFALL...ESPECIALLY WITH THE LIGHT RAIN THAT FELL
ACROSS THE REGION YESTERDAY. THE LOOSE SOILS OF THE CHALK CLIFFS IN
CHAFFEE COUNTY WOULD BE PRONE TO FLASH FLOODING TODAY AS WELL.
CONVECTION WHICH FIRES OFF TO THE NORTH AND MOVES ACROSS THE NE
PLAINS WILL SEND AN INITIAL CONVECTIVE OUTFLOW BOUNDARY THROUGH THE
NRN I-25 CORRIDOR...WITH A WIND SHIFT FROM THE WEST TO NORTHWEST
DURING THE EVENING PRIOR TO THE MAIN FRONT DROPPING SOUTHWARD
THROUGH THE PLAINS AFTER 03Z. LATEST NAM12 ADVECTS SOME LOWER 50S
DEW POINTS BEHIND THE FRONT INTO SE CO BY MON MORNING...THEN SHIFTS
WINDS WEAKLY FROM THE EAST AND MIXES OUT LOW LEVEL MOISTURE AGAIN BY
AFTERNOON...WITH DEW POINTS FALLING OFF INTO THE LOWER TO MID 40S BY
21Z. DRY AIR ALOFT WILL STILL BE LINGERING OVER SOUTHERN
AREAS...WITH MONSOON PLUME WITH ITS WEAK EMBEDDED IMPULSES EXTENDING
ACROSS UT THROUGH NRN AND CENTRAL CO. THUS GREATEST THREAT FOR
WIDESPREAD THUNDERSTORMS/HEAVY RAIN WILL BE ACROSS NORTHERN PORTIONS
OF THE FORECAST AREA. QUITE A BIT OF DISCREPANCIES IN THE MODEL
QPFS BETWEEN THE DRIER NAM AND THE WET GFS. GFS KEEPS DEW POINTS
ACROSS THE SE PLAINS IN THE 50S THROUGH THE AFTERNOON WITH STRONGER
EASTERLY UPSLOPE FLOW...RESULTING IN GREATER QPF FOR THE SE MTS.
ECMWF SIDES WITH THE DRIER NAM12...AND SREF IS SOMEWHERE IN
BETWEEN...THOUGH ITS QPF IS GENERALLY UNDER .25 ON AN AREAL AVERAGE
BASIS. LCLS STILL LOOK A LITTLE TOO HIGH TO JUSTIFY A FLASH FLOOD
WATCH AT THIS POINT...SO PLAN TO HOLD OFF. LATER SHIFTS CAN GET A
LOOK AT THE HIGH RES MODEL RUNS TONIGHT AND DECIDE IF ONE IS
JUSTIFIED. A LOT WILL DEPEND ON HOW FAR NORTH THE DRY AIR ALOFT
PROGRESSES OVERNIGHT. HOWEVER...THERE COULD BE A HEIGHTENED CONCERN
FOR FLASH FLOODING ON THE WALDO BURN SCAR TOMORROW VS THE PAST FEW
DAYS...AS SFC DEW POINTS SHOULD REMAIN A LITTLE HIGHER.
OTHERWISE...TEMPERATURES SHOULD BE SLIGHTLY COOLER ACROSS THE PLAINS
BEHIND THE FRONT...THOUGH STILL APPROACHING 100 NEAR THE CO/KS
BORDER. MTN AREAS WILL SEE HIGHS SIMILAR TO A COUPLE DEGREES
WARMER. -KT
LONG TERM...
(MONDAY NIGHT THROUGH SUNDAY)
LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES AND
POPS. 12Z/28TH GFS40 INDICATES THAT UPPER HIGH CENTERED OVER
NORTHEASTERN NEW MEXICO AT 00Z TUESDAY HOVERS OVER NEW MEXICO INTO
NEXT WEEKEND WHILE THE 12Z/28TH ECMWF SUGGESTS THAT HEALTHY UPPER
HIGH LOCATED OVER NORTHEASTERN NEW MEXICO AT 00Z TUESDAY SHIFTS
INTO NORTH TEXAS BY 06Z SATURDAY. IN ADDITION...THE 06Z/28TH DGEX
SUGGESTS THAT THE UPPER HIGH WILL BE OVER MISSOURI BY NEXT SUNDAY.
AT THE SURFACE...NORTHERLY SURGES IMPACTING PRIMARILY EASTERN
PORTIONS OF THE FORECAST DISTRICT ARE ANTICIPATED THURSDAY
MORNING...WITH A STRONGER NORTHERLY SURGE EXPECTED SATURDAY
MORNING.
THE COMBINATION OF RELATIVELY PERSISTENT DEEPER ATMOSPHERIC
MOISTURE/HIGHER PRECIPITABLE WATER VALUES IN COMBINATION WITH
THE DAILY HEATING CYCLE...THE AFORE-MENTIONED NORTHERLY SURGES
AND INCREASING UPPER ENERGY(ESPECIALLY AFTER TUESDAY) WILL ALLOW
ISOLATED TO SCATTERED PRIMARILY AFTERNOON AND EVENING
THUNDERSTORMS(SOME CONTAINING LOCALLY HEAVY RAIN AND HAIL) TO BE
NOTED OVER THE MAJORITY OF THE FORECAST DISTRICT INTO NEXT
WEEKEND.
BLEND OF LATEST COMPUTER SIMULATIONS SUGGEST THAT INCREASING
PROBABILITIES OF THUNDERSTORMS WILL BE POSSIBLE OVER PORTIONS OF
THE I-25 CORRIDOR/EASTERN COLORADO PLAINS AS THE WEEK PROGRESSES
AND INTO NEXT WEEKEND.
AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE
LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND FLASH
FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS THE
WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
MAXIMUM AND MINIMUM TEMPERATURES FROM TUESDAY NIGHT INTO NEXT
SUNDAY ARE STILL EXPECTED TO RUN A CATEGORY OR TWO ABOVE LATE
JULY/EARLY AUGUST CLIMATOLOGICAL AVERAGES.
AVIATION...
VCTS WILL BE POSSIBLE AT TAF SITES THROUGH 02-03Z. GUSTY ERRATIC
WINDS UP TO 35 KTS WILL BE POSSIBLE NEAR -TSRA POSSIBLY AFFECTING
THE KCOS AND KPUB SITES. VFR CIGS/VIS IN LIGHT RAIN WILL ALSO BE
POSSIBLE SHOULD STORMS BE LUCKY ENOUGH TO HIT THE TERMINAL. AT THIS
POINT THREAT LOOKS FAIRLY LOW...AND WILL MAINTAIN VCTS. CONVECTION
OVER THE MOUNTAINS SHOULD SHIFT WINDS FROM THE NORTH TO NORTHWEST AT
BOTH KCOS AND KPUB AROUND 00Z WITH GUSTS IN THE 15-25 KT RANGE.
FRONT WILL DROP THROUGH THE PLAINS AFTER 03Z...WHICH SHOULD KEEP
WINDS FROM THE NORTH AT AROUND 10-15 KTS FOR BOTH KCOS AND KPUB
THROUGH 09Z. MEANWHILE...THUNDERSTORM COVERAGE SHOULD DECREASE
AFTER SUNSET...THOUGH ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE
OVER AND NEAR THE MOUNTAINS THROUGH AT LEAST 06Z. ON MONDAY...WINDS
WILL SWING AROUND FROM THE EAST TO SOUTHEAST ACROSS THE PLAINS
DURING THE AFTERNOON WITH A SLIGHTLY BETTER CHANCE FOR -TSRA AT THE
KCOS TAF SITE DURING THE AFTERNOON. WINDS WILL REMAIN LIGHT AT KALS.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
88/40
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1106 PM MDT SUN JUL 29 2012
.AVIATION...
ISOLATED THUNDERSTORMS CONTINUE OVER THE MOUNTAINS OVERNIGHT BUT
SHOULD NOT IMPACT THE TERMINALS. NORTH WINDS HAVE BEEN GUSTY AT
KCOS AND KPUB...WITH GUSTS APPROACHING 35-40 KTS. THESE WINDS WILL
CONTINUE THROUGH 09Z TONIGHT WITH LIGHTER WINDS THROUGH THE
MORNING. THUNDERSTORMS ARE FORECAST TO REDEVELOP OVER THE
MOUNTAINS AND SPREAD EAST ACROSS THE TERMINALS DURING THE LATE
AFTERNOON HOURS. GUSTY OUTFLOW WINDS WILL BE THE MAIN THREAT.
MOZLEY
&&
.PREV DISCUSSION... /ISSUED 927 PM MDT SUN JUL 29 2012/
UPDATE...
UPDATED TO REMOVE POPS FOR THE PLAINS FOR THE REST OF TONIGHT. AN
OUTFLOW BOUNDARY HAS SHIFTED SOUTH ACROSS THE PLAINS WHICH HAS
HELPED STABILIZE THE PLAINS. ISOLATED SHOWER AND THUNDERSTORM
ACTIVITY WILL CONTINUE OVER THE MOUNTAIN REGIONS...ESPECIALLY THE
CONTINENTAL DIVIDE AREA. NO OTHER CHANGES AT THIS TIME. 88
PREV DISCUSSION... /ISSUED 355 PM MDT SUN JUL 29 2012/
SHORT TERM...
(TONIGHT AND MONDAY)
WATER VAPOR LOOPS TODAY CONTINUE TO SHOW DRY AIR PUNCHING IN UNDER
THE RIDGE ACROSS NM/SRN CO. LATEST AMSU SSM/I PRECIP WATER SAT PICS
ALSO SHOWING VALUES DROPPING OFF TO THE SOUTH...BUT STILL AN AXIS OF
HIGH PRECIP WATERS EXTENDING ACROSS NW CO. A COUPLE SHORTWAVES
EVIDENT IN WV PICS ACROSS UT/NW CO. MAIN FORCING FROM THESE MAY END
UP STAYING JUST TO THE NORTH OF THE FORECAST...BUT STILL ENOUGH
MOISTURE PRESENT WITHIN MONSOON PLUME ALOFT FOR SCATTERED TO
NUMEROUS SHOWERS AND THUNDERSTORMS ACROSS THE MOUNTAINS. GREATEST
COVERAGE WILL BE ACROSS CHAFFEE AND LAKE COUNTIES...AND POSSIBLY
TELLER...THOUGH EACH SUCCESSIVE HRRR RUN SEEMS TO SHIFT
AXIS OF HIGHER QPF TO THE NORTH ACROSS PARK COUNTY. WITH PRECIP
WATERS STILL AVERAGING AROUND OR SLIGHTLY BETTER THAN 100 PERCENT OF
NORMAL ACROSS THE SOUTHEAST MTS/ADJACENT PLAINS...LOCALLY HEAVY RAIN
WILL STILL BE A THREAT...PARTICULARLY FOR THE WALDO CANYON BURN SCAR
WHERE SOILS ARE SUSCEPTIBLE TO FLASH FLOODING WITH EVEN MINOR
AMOUNTS OF RAINFALL...ESPECIALLY WITH THE LIGHT RAIN THAT FELL
ACROSS THE REGION YESTERDAY. THE LOOSE SOILS OF THE CHALK CLIFFS IN
CHAFFEE COUNTY WOULD BE PRONE TO FLASH FLOODING TODAY AS WELL.
CONVECTION WHICH FIRES OFF TO THE NORTH AND MOVES ACROSS THE NE
PLAINS WILL SEND AN INITIAL CONVECTIVE OUTFLOW BOUNDARY THROUGH THE
NRN I-25 CORRIDOR...WITH A WIND SHIFT FROM THE WEST TO NORTHWEST
DURING THE EVENING PRIOR TO THE MAIN FRONT DROPPING SOUTHWARD
THROUGH THE PLAINS AFTER 03Z. LATEST NAM12 ADVECTS SOME LOWER 50S
DEW POINTS BEHIND THE FRONT INTO SE CO BY MON MORNING...THEN SHIFTS
WINDS WEAKLY FROM THE EAST AND MIXES OUT LOW LEVEL MOISTURE AGAIN BY
AFTERNOON...WITH DEW POINTS FALLING OFF INTO THE LOWER TO MID 40S BY
21Z. DRY AIR ALOFT WILL STILL BE LINGERING OVER SOUTHERN
AREAS...WITH MONSOON PLUME WITH ITS WEAK EMBEDDED IMPULSES EXTENDING
ACROSS UT THROUGH NRN AND CENTRAL CO. THUS GREATEST THREAT FOR
WIDESPREAD THUNDERSTORMS/HEAVY RAIN WILL BE ACROSS NORTHERN PORTIONS
OF THE FORECAST AREA. QUITE A BIT OF DISCREPANCIES IN THE MODEL
QPFS BETWEEN THE DRIER NAM AND THE WET GFS. GFS KEEPS DEW POINTS
ACROSS THE SE PLAINS IN THE 50S THROUGH THE AFTERNOON WITH STRONGER
EASTERLY UPSLOPE FLOW...RESULTING IN GREATER QPF FOR THE SE MTS.
ECMWF SIDES WITH THE DRIER NAM12...AND SREF IS SOMEWHERE IN
BETWEEN...THOUGH ITS QPF IS GENERALLY UNDER .25 ON AN AREAL AVERAGE
BASIS. LCLS STILL LOOK A LITTLE TOO HIGH TO JUSTIFY A FLASH FLOOD
WATCH AT THIS POINT...SO PLAN TO HOLD OFF. LATER SHIFTS CAN GET A
LOOK AT THE HIGH RES MODEL RUNS TONIGHT AND DECIDE IF ONE IS
JUSTIFIED. A LOT WILL DEPEND ON HOW FAR NORTH THE DRY AIR ALOFT
PROGRESSES OVERNIGHT. HOWEVER...THERE COULD BE A HEIGHTENED CONCERN
FOR FLASH FLOODING ON THE WALDO BURN SCAR TOMORROW VS THE PAST FEW
DAYS...AS SFC DEW POINTS SHOULD REMAIN A LITTLE HIGHER.
OTHERWISE...TEMPERATURES SHOULD BE SLIGHTLY COOLER ACROSS THE PLAINS
BEHIND THE FRONT...THOUGH STILL APPROACHING 100 NEAR THE CO/KS
BORDER. MTN AREAS WILL SEE HIGHS SIMILAR TO A COUPLE DEGREES
WARMER. -KT
LONG TERM...
(MONDAY NIGHT THROUGH SUNDAY)
LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE TEMPERATURES AND
POPS. 12Z/28TH GFS40 INDICATES THAT UPPER HIGH CENTERED OVER
NORTHEASTERN NEW MEXICO AT 00Z TUESDAY HOVERS OVER NEW MEXICO INTO
NEXT WEEKEND WHILE THE 12Z/28TH ECMWF SUGGESTS THAT HEALTHY UPPER
HIGH LOCATED OVER NORTHEASTERN NEW MEXICO AT 00Z TUESDAY SHIFTS
INTO NORTH TEXAS BY 06Z SATURDAY. IN ADDITION...THE 06Z/28TH DGEX
SUGGESTS THAT THE UPPER HIGH WILL BE OVER MISSOURI BY NEXT SUNDAY.
AT THE SURFACE...NORTHERLY SURGES IMPACTING PRIMARILY EASTERN
PORTIONS OF THE FORECAST DISTRICT ARE ANTICIPATED THURSDAY
MORNING...WITH A STRONGER NORTHERLY SURGE EXPECTED SATURDAY
MORNING.
THE COMBINATION OF RELATIVELY PERSISTENT DEEPER ATMOSPHERIC
MOISTURE/HIGHER PRECIPITABLE WATER VALUES IN COMBINATION WITH
THE DAILY HEATING CYCLE...THE AFORE-MENTIONED NORTHERLY SURGES
AND INCREASING UPPER ENERGY(ESPECIALLY AFTER TUESDAY) WILL ALLOW
ISOLATED TO SCATTERED PRIMARILY AFTERNOON AND EVENING
THUNDERSTORMS(SOME CONTAINING LOCALLY HEAVY RAIN AND HAIL) TO BE
NOTED OVER THE MAJORITY OF THE FORECAST DISTRICT INTO NEXT
WEEKEND.
BLEND OF LATEST COMPUTER SIMULATIONS SUGGEST THAT INCREASING
PROBABILITIES OF THUNDERSTORMS WILL BE POSSIBLE OVER PORTIONS OF
THE I-25 CORRIDOR/EASTERN COLORADO PLAINS AS THE WEEK PROGRESSES
AND INTO NEXT WEEKEND.
AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE
LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND FLASH
FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS THE
WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
MAXIMUM AND MINIMUM TEMPERATURES FROM TUESDAY NIGHT INTO NEXT
SUNDAY ARE STILL EXPECTED TO RUN A CATEGORY OR TWO ABOVE LATE
JULY/EARLY AUGUST CLIMATOLOGICAL AVERAGES.
AVIATION...
VCTS WILL BE POSSIBLE AT TAF SITES THROUGH 02-03Z. GUSTY ERRATIC
WINDS UP TO 35 KTS WILL BE POSSIBLE NEAR -TSRA POSSIBLY AFFECTING
THE KCOS AND KPUB SITES. VFR CIGS/VIS IN LIGHT RAIN WILL ALSO BE
POSSIBLE SHOULD STORMS BE LUCKY ENOUGH TO HIT THE TERMINAL. AT THIS
POINT THREAT LOOKS FAIRLY LOW...AND WILL MAINTAIN VCTS. CONVECTION
OVER THE MOUNTAINS SHOULD SHIFT WINDS FROM THE NORTH TO NORTHWEST AT
BOTH KCOS AND KPUB AROUND 00Z WITH GUSTS IN THE 15-25 KT RANGE.
FRONT WILL DROP THROUGH THE PLAINS AFTER 03Z...WHICH SHOULD KEEP
WINDS FROM THE NORTH AT AROUND 10-15 KTS FOR BOTH KCOS AND KPUB
THROUGH 09Z. MEANWHILE...THUNDERSTORM COVERAGE SHOULD DECREASE
AFTER SUNSET...THOUGH ISOLATED THUNDERSTORMS WILL STILL BE POSSIBLE
OVER AND NEAR THE MOUNTAINS THROUGH AT LEAST 06Z. ON MONDAY...WINDS
WILL SWING AROUND FROM THE EAST TO SOUTHEAST ACROSS THE PLAINS
DURING THE AFTERNOON WITH A SLIGHTLY BETTER CHANCE FOR -TSRA AT THE
KCOS TAF SITE DURING THE AFTERNOON. WINDS WILL REMAIN LIGHT AT KALS.
-KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
88/40
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1145 PM MDT SUN JUL 29 2012
.UPDATE...
ISSUED AT 1140 PM MDT SUN JUL 29 2012
UPDATED SHORT-TERM GRIDS TO REMOVE MENTION OF PRECIP FROM SOUTHERN
PORTIONS OF THE FORECAST AREA BASED ON LATEST RADAR TRENDS. ALSO
INCREASED POPS ALONG AND NORTH OF THE HIGHWAY 36 CORRIDOR FOR THE
NEXT FEW HOURS. LOWERED MINS ACROSS THE WESTERN PORTIONS OF THE
AREA A FEW DEGREES AS WELL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY AFTERNOON)
ISSUED AT 120 PM MDT SUN JUL 29 2012
LATEST WV IMAGERY AND RUC H5 ANALYSIS SHOW LARGE RIDGE CONTINUING TO
DOMINATE US PATTERN WITH CENTER OVER NORTHERN TEXAS. ALONG THE
WEST/NORTHWEST EXTENT OF THE RIDGE MONSOONAL MOISTURE CONTINUES TO
STREAM NORTH ACROSS THE INTER-MOUNTAIN WEST TOWARDS THE CWA. AT THE
SURFACE A LINGERING BAROCLINIC ZONE/DECAYED STATIONARY FRONT REMAINS
IN PLACE OVER THE CWA.
EARLY MORNING SHOWERS HAVE MOVED OFF TO THE EAST...WITH CLEARING
OCCURRING TO THE SOUTH AND WEST. MIXED LAYER CAPE VALUES ACROSS THE
AREA ARE CURRENTLY IN THE 500-1500 J/KG RANGE AND SHOULD INCREASE
WITH CLEARING AS LOW LEVEL LAPSE RATES STEEPEN. A WEAK SHORTWAVE
TROUGH IS PROGGED TO MOVE ACROSS SW NEBRASKA...AND MAY BE THE
FEATURE THAT HELPS GET THINGS GOING AGAIN TONIGHT. THE LATEST HRRR
WOULD INDICATE THAT THUNDERSTORM REDEVELOPMENT LIKELY WILL HOLD OFF
UNTIL AFTER 00Z...HOWEVER IT IS DEVELOPING WIDESPREAD CONVECTION
FURTHER SOUTH THAN WHAT THE LATEST NAM/GFS WOULD INDICATE...SO HAVE
KEPT POPS IN CHANCE CATEGORY THIS EVENING/OVERNIGHT. OVERALL SHEAR
IS WEAK AND THERE IS VERY LITTLE TO GET STORMS MOVING IN PROXIMITY
TO BAROCLINIC ZONE. WITH VERY HIGH PWAT VALUES IN EXCESS OF 1.5
HEAVY RAIN AND LOCALIZED FLOODING WILL BE POSSIBLE WITH THESE SLOW
MOVING THUNDERSTORMS. AS WITH YESTERDAY COVERAGE IS STILL A
QUESTION...WITH BEST COVERAGE RIGHT NOW EXPECTED TO BE ACROSS THE
NORTHERN HALF OTHER CWA OVERNIGHT IN PROXIMITY TO SHORTWAVE TROUGH.
WITH BAROCLINIC ZONE IN PLACE THROUGH MONDAY SHOWERS/THUNDERSTORMS
COULDN`T BE RULED OUT THROUGH MONDAY AFTERNOON AS WEAK PULSES
CONTINUE TO MOVE WITHIN PROXIMITY OF THE CWA.
TEMPERATURES SHOULD BE COOLER ON MONDAY AFTERNOON HIGHS IN THE MID
TO UPPER 90S ACROSS THE CWA. EASTERLY FLOW WILL DEVELOP ACROSS THE
REGION...AND H85 TEMPS WILL MODERATE SOME WITH VALUES ABOUT 3C COOLER.
DEPENDING ON CLOUD COVER SOME LOCATIONS COULD SEE HIGHS ON MONDAY
CLOSER TO NORMAL VALUES IN THE LOW 90S.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 205 PM MDT SUN JUL 29 2012
RIDGE OVER THE SOUTHERN PLAINS WILL DRIFT WESTWARD. TEMPERATURES
WILL CONTINUE TO BE ABOVE NORMAL. THE RIDGE IS FAR ENOUGH SOUTH
THAT SHORTWAVE TROUGHS COMING OVER THE TOP WILL BRING OCCASIONAL
CHANCES FOR THUNDERSTORMS. MODELS HINTING AT FAIRLY STRONG ONE
TUESDAY NIGHT WITH POSSIBLE MCS DEVELOPING IN EASTERN COLORADO AND
MOVING ACROSS THE FORECAST AREA. BUMPED POPS UP TO
CHANCE...ESPECIALLY IN THE WEST. THE PATTERN BASICALLY REPEATS
THROUGH THE END OF THE WEEK...SO COULD END UP WITH A RATHER WET
PATTERN. STRONG SYSTEM WILL MOVE ACROSS THE NORTHERN PLAINS ON
FRIDAY AND DRIVE A COLD FRONT THROUGH THE AREA. COOLER
TEMPERATURES FOLLOW ON SATURDAY...AT LEAST CLOSER TO NORMAL.
DESPITE THE POST FRONTAL UPSLOPE AT THE SURFACE...SHORTWAVE
RIDGING IS FORECAST OVER THE WEEKEND...SO THINK PRECIPITATION
CHANCES WILL COME TO AN END.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1140 PM MDT SUN JUL 29 2012
PERIODIC MVFR/IFR VISBY CONTINUES AT KMCK WITH A COMPLEX OF
SHOWERS AND THUNDERSTORMS CONTINUING TO IMPACT THE TERMINAL.
APPEARS CONDITIONS WILL BE VARIABLE BETWEEN MVFR/IFR AND VFR FOR
THE NEXT FEW HOURS BEFORE VFR CONDITIONS BECOME ESTABLISHED AROUND
09Z. PRECIP CHANCES HAVE ESSENTIALLY ENDED FOR KGLD FOR THE NIGHT
WITH GUSTY NORTHERLY WINDS UP TO AROUND 30KTS CONTINUING FOR THE
NEXT FEW HOURS IN THE WAKE OF THE CONVECTIVE ACTIVITY FURTHER
NORTH. WINDS DURING THE DAY MONDAY WILL VEER TO THE NORTHEAST/EAST
WITH GUSTS AROUND 20KTS POSSIBLE. STILL CAN`T RULE OUT CONVECTION
MONDAY AFTERNOON AND EVENING BUT SIGNAL IS STILL NOT STRONG
ENOUGH TO WARRANT INCLUSION.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FOLTZ
SHORT TERM...DR
LONG TERM...024
AVIATION...FOLTZ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
444 AM EDT MON JUL 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT MON JUL 30 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS BTWN GENERAL TROFFING CENTERED NEAR HUDSON BAY AND
PERSISTENT RDG AXIS OVER THE HI PLAINS. WITH LOSS OF DAYTIME
HEATING...SHRA/TS THAT IMPACTED THE CWA LAST EVNG HAVE DIMINISHED.
BUT ANOTHER LINE OF SHRA/TS IS PUSHING SEWD THRU THE MN ARROWHEAD IN
ADVANCE OF POTENT SHRTWV MOVING ESEWD IN MANITOBA TOWARD NW MN AND
LEFT EXIT OF SUPPORTING 75KT H3 JET MAX NOTED IN THE NRN PLAINS.
THIS LINE OF TS PROMPTED THE ISSUANCE OF A WATCH FOR MUCH OF NE
MN...WITH SOME SVR TS GIVEN STEEP MID LVL LAPSE RATES SHOWN ON THE
00Z INL RAOB THAT CONTRIBUTED TO MUCAPE IN EXCESS OF 2000 J/KG AS
WELL AS EFFECTIVE DEEP LYR SHEAR UP TO 40KTS UNDER UNIDIRECTIONAL
WNW FLOW ALF PER SPC ANALYSIS. PRESENCE OF DRIER AIR ALF SHOWN ON
00Z RAOBS HAS CONTRIBUTED TO DCAPE AOA 1000 J/KG IN PORTIONS OF THE
AREA IMPACTED BY THE WATCH. RECENT TRENDS HOWEVER ARE FOR THE STORMS
TO WEAKEN AS THEY MOVE INTO A BIT MORE STABLE AIR IMPACTED BY
NOCTURNAL COOLING AND AXIS OF LOWER H85 DEWPTS OVER CENTRAL MN.
MAIN FCST CONCERNS THIS PACKAGE INCLUDE CONVECTIVE TRENDS INTO TNGT
AND POTENTIAL FOR SVR STORMS.
TODAY...VIGOROUS SHRTWV TO THE NW IS PROGGED TO MOVE TO JUST N OF
INL AT 12Z MON AND THEN INTO FAR NE LK SUP BY 00Z TUE WITH SWATH OF
VIGOROUS DVPA/DEEP LYR QVECTOR CNVGC MOVING W-E ACRS UPR MI.
ALTHOUGH AXIS OF LOWER H85 THETA E CONTRIBUTING TO WEAKENING STORMS
IN MN NOW MAY TEND TO REDUCE COVERAGE/INTENSITY THIS MRNG...ONSET OF
DAYTIME HEATING AND ARRIVAL OF MORE IMPRESSIVE H85 THETA E ADVECTION
BY THIS AFTN IN PRESENCE OF THE HEFTY DYNAMICS SHOULD LEAD TO NMRS
SHRA/TS...ESPECIALLY OVER THE CNTRL AND E WHERE ARRIVAL OF DYNAMICS
APPEAR TO BE MOST IN SYNC WITH DAYTIME HEATING. NAM/GFS FCST SNDGS
INDICATE SBCAPE WL REACH AOA 2000 J/KG AS HI TEMPS RISE WELL INTO
THE 80S AWAY FM LK MODERATION MOST PRONOUNCED OFF LK MI. DRYING ALF
UNDER UNIDIRECTIONAL WNW FLOW ON THE SRN FLANK OF SHRTWV TRACK IS
FCST TO CONTRIBUTE TO SFC-10K FT AGL DELTA THETA E UP TO 25C...VERY
FAVORABLE PER THE MQT SEVERE WX CHECKLIST TO ENHANCE DCAPE. THE
BIGGEST DRAWBACK FOR ORGANIZED SEVERE WX IS FCST RATHER MODEST DEEP
LYR SHEAR ONLY 25-30KTS. THIS WEAKER SHEAR MAY RESULT IN MORE PULSE
SVR EPISODES...WITH THE BETTER CHC FOR ORGANIZED STORMS WHERE LK
BREEZE CNVGC OVER MAINLY THE E HALF MIGHT ENHANCE THE SHEAR AS WELL
AS INCRS LLVL CNVGC AND SHRA/TS COVERAGE. SHRA/TS WL DIMINISH OVER
THE W IN THE AFTN WITH ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/LLVL
DRYING IN THE WAKE OF SHRTWV PASSAGE/ATTENDANT COLD FROPA.
TNGT...DRYING/NEGATIVE H85 THETA E ADVECTION IN THE WAKE OF SHRTWV
MOVING INTO SE ONTARIO AND LOSS OF DAYTIME HEATING WL CAUSE SHRA/TS
TO DIMINISH NW-SE. HOWEVER...MODELS SHOW QUITE A BIT OF LINGERING
LLVL MSTR WITH NNW FLOW IN THE WAKE OF DEPARTING SHRTWV/SFC LO. LO
CLDS MAY BE ESPECIALLY TENACIOUS IN THE UPSLOPE AREAS NEAR LK SUP...
WHERE THERE MAY EVEN BE SOME -DZ/SPRINKLES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 443 AM EDT MON JUL 30 2012
VERY ACTIVE FORECAST PERIOD...AS UPPER MI SITS IN AN UPPER LEVEL
TROUGHING PATTERN THROUGH TUESDAY...BEFORE STRONG RIDGING PATTERN
OVER MUCH OF THE CONUS BEGINS TO MOVE EASTWARD INTO THE REGION.
ALONG THIS RIDGE...SEVERAL SHORTWAVES WILL PASS OVER UPPER MI
BRINGING CHANCES FOR TSRA WED AND THUR AND THEN AGAIN DURING THE
WEEKEND.
AFTER EXITING 500MB SHORTWAVE DURING THE DAY TUESDAY...STRONG
RIDGING WILL BEGIN TO PUSH IN FROM WEST TO EAST...WHICH WILL ALSO
TRANSLATE TO SURFACE HIGH PRESSURE. AS WINDS TURN TO A NORTHERLY
DIRECTION...EXPECT AN INFLUX OF DRY AIR AND CLEARING SKIES ACROSS
THE REGION. SUCH A WIND DIRECTION WILL CAUSE HIGH TEMPERATURES TO BE
SLIGHTLY COOLER THAN THE PREVIOUS DAY...BUT STILL A QUITE
COMFORTABLE MID 70 TO LOW 80 DEGREE RANGE. WINDS WILL THEN TURN TO A
MORE SOUTHERLY DIRECTION ON THE BACKSIDE OF THE SURFACE
HIGH...ALLOWING WARMER WINDS OFF THE LAKE DURING THE FIRST PART OF
THE NIGHT...AND THEN SOUTHERLY WINDS ACROSS THE INTERIOR FOR THE
LAST HALF. THIS SHOULD MODERATE TEMPERATURES TO STAY AT OR ABOVE
NORMAL. UNFORTUNATELY...SURFACE HIGH PRESSURE WILL BE SHORT-LIVED AS
THE FIRST OF SEVERAL SHORTWAVES BEGINS TO TRAVERSE THE AREA BY LATE
WEDNESDAY WITH UPPER LEVEL RIDGING IN PLACE.
MAIN SHORTWAVE AND SURFACE LOW PRESSURE WILL SPREAD ACROSS LAKE
SUPERIOR LATE WEDNESDAY AND THROUGH THE DAY THURSDAY. HOWEVER THERE
IS SOME DISCREPANCY BETWEEN THE MODELS...AS THE NAM IS SLIGHTLY
DELAYED IN THE ARRIVAL OF THE SYSTEM...AND IS MUCH MORE AMPLIFIED
THAN THE OTHER MODELS. REGARDLESS...OVERALL EFFECTS OF THE SYSTEM
WILL BE SIMILAR...STARTING WITH THE INFLUX OF MOIST SOUTHERLY WINDS
/LLVL JET/ AHEAD OF THE SYSTEM AND DECENT WAA. THIS WILL ALLOW HIGH
TEMPERATURES WEDNESDAY TO RISE TO WELL ABOVE NORMAL INLAND /MID TO
UPPER 80S POSSIBLE/. WITH PRESENCE OF AFTERNOON LAKE BREEZES...AND
WARM/MOIST/UNSTABLE AIR IN PLACE...SHOULD SEE SOME AFTERNOON
CONVECTION INLAND AS A RESULT.
AS SYSTEM NEARS...EXPECT A WELL DEFINED AREA OF CONVERGENCE TO SPAWN
PRECIP ACROSS THE ENTIRE CWA WEDNESDAY NIGHT THROUGH
THURSDAY...DESPITE OUR LOCATION IN THE RIGHT EXIT REGION OF A VERY
WEAK JET. MU CAPE VALUES ARE POINTING AT CENTRAL AND WESTERN UPPER
MI GETTING UP TO BETWEEN 1.4-1.8K J/KG IN WEDNESDAY EVENING...AND
THEN MAXING OUT AROUND 2K J/KG OVERNIGHT...THOUGH CAPE WILL BE
FAIRLY SKINNY AND MAINLY CONFINED TO THE MID AND UPPER LEVELS WITH
THE BEST MOISTURE...WHILE THE LOWER LEVELS SHOULD REMAIN FAIRLY DRY.
THAT BEING SAID...MODEL SOUNDINGS SHOW SOME IMPRESSIVE SHEAR
THROUGHOUT THE ENTIRE COLUMN /BOTH DIRECTIONAL AND SPEED/ SO COULD
SEE SOME WIDESPREAD ELEVATED TSRA DEVELOPMENT...BUT WITH LITTLE
MOISTURE IN THE LOW LEVELS...SHOULD/T BE MUCH OF A RAIN SOAKER.
SHORTWAVE AND BEST FORCING SHOULD MOVE OFF TO THE EAST DURING THE
DAY THURSDAY AHEAD OF SURFACE COLD FRONT...BUT THE BREAK IN PRECIP
WILL BE SHORT-LIVED AS LARGER 500MB SHORTWAVE OVER SASKATCHEWAN
FRIDAY AFTERNOON BEGINS TO MOVE ALONG THE SAME TRACK SOUTHEAST
TOWARDS THE UPPER GREAT LAKES. WHILE ALL MODELS ARE IN GOOD
AGREEMENT OF THIS LOW STRENGTHENING AND BECOMING CLOSED OFF AS IT
REACHES THE UPPER GREAT LAKES...THERE IS LITTLE AGREEMENT IN THE
EXACT TIMING AND TRACK...SO WILL GO WITH A GENERAL MODEL CONSENSUS
AT THIS TIME. WITH SOME LOW LEVEL MOISTURE FROM PREVIOUS SYSTEM
ALREADY IN PLACE...COULD SEE SOME SCATTERED SHRA/TSRA DEVELOPMENT AS
EARLY AS FRIDAY MORNING FAR WEST WITH THIS SYSTEM. A STRONG UPPER
LEVEL JET WILL CRUISE OVER UPPER MI BY SATURDAY PUTTING US IN THE
LEFT ENTRANCE REGION...FURTHERING ENHANCING PRECIP CHANCES. PWAT
VALUES WILL QUICKLY RISE TO 160 PERCENT OF NORMAL THROUGH SATURDAY
MORNING AS SURFACE WARM FRONT AND WELL DEFINED AREA OF QVECTOR CONV
TRAVERSES FROM WEST TO EAST. UNLIKE WEDNESDAY NIGHT/THURSDAY...THIS
SYSTEM WILL HAVE ABUNDANT MOISTURE THROUGH ALL LAYERS...SO EXPECT
THIS TO BE A GOOD RAIN EVENT. BY SATURDAY AFTERNOON COLD FRONT WILL
PRESENT IMPRESSIVE FORCING...LATEST GFS HAS 0-3KM COMPUTED CAPE
VALUES MAXING OUT AROUND 1.2K SOUTH CENTRAL...WITH MU CAPE VALUES
2.2-2.6K J/KG OVER MUCH OF THE WESTERN AND CENTRAL CWA. FORECAST
SOUNDINGS SHOW MUCH IMPROVEMENT OVER THE SKINNY ELEVATED CAPE DURING
PREVIOUS EVENT...AND ONCE AGAIN SHEAR LOOKS TO BE VERY IMPRESSIVE
BOTH FOR DIRECTION AND SPEED. DCAPE ON THE OTHER HAND WILL BE ON THE
DIMINISHING TREND DURING THE DAY SATURDAY...SO ONCE STORMS DEVELOP
EXPECT THE MAIN THREAT TO BE HEAVY RAINS...ABUNDANT LIGHTNING...AND
POTENTIAL HAIL.
THE SYSTEM WILL CONTINUE ON ITS TRACK TO THE SOUTHEAST DURING THE
NIGHT SATURDAY...WITH A WELCOME BREAK IN PRECIP BY SUNDAY AFTERNOON
AS HIGH PRESSURE ONCE AGAIN REGAINS CONTROL
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 131 AM EDT MON JUL 30 2012
STRONG UPPER DISTURBANCE MOVING THROUGH SOUTH CENTRAL CANADA HAS
PRODUCED CLUSTER OF TSRA OVER WRN ONTARIO AND NRN MN EARLY THIS
MORNING. THIS DISTURBANCE WILL MOVE ACROSS THE UPPER GREAT LAKES ON
MONDAY BRINGING A CHANCE OF SHRA AND POSSIBLY THUNDERSTORMS TO THE
TAF SITES. THE BEST CHANCE OF THUNDERSTORMS WILL BE OVER KSAW WHERE
DAYTIME HEATING/INSTABILITY WILL BE ABLE TO BUILD BEFORE THE ARRIVAL
OF THE DISTURBANCE AND ASSOC SFC TROUGH. DEVELOPING LAKE BREEZE
BOUNDARIES MAY ALSO HELP AFTERNOON CONVECTION ALONG AT KSAW. EXPECT
ANY LINGERING SHRA TO END AT KIWD AND KCMX BY EARLY AFTERNOON AND AT
KSAW BY EARLY EVENING IN WAKE OF THE SFC TROUGH. GIVEN UNCERTAINTY
WITH THE EXTENT AND TRACK OF PCPN OVER LAKE SUPERIOR ELECTED NOT TO
INCLUDE ANY MVFR LAKE STRATUS OR FOG MENTION IN THE TAFS MON EVENING
ALTHOUGH THIS POSSIBILITY MAY NEED TO BE CONSIDERED...ESPECIALLY
ONCE WINDS SHIFT NW BEHIND THE TROUGH LATE MONDAY INTO MONDAY
EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT MON JUL 30 2012
EXPECT SSW WINDS UP TO 20 KTS AND SOME TS IN ADVANCE OF LO PRES TROF
THAT IS FORECAST TO DRIFT ACROSS LAKE SUPERIOR LATE TODAY AND
TONIGHT. BEHIND THE TROF PASSAGE...WINDS WILL SHIFT TO THE NNW AS
HIGH PRESSURE SETS IN...HOWEVER THE W LAKE COULD CONTINUE TO SEE
GUSTS BETWEEN 15 AND 20 KNOTS THROUGH THE MORNING HOURS WITH THIS
WIND DIRECTION. ANOTHER TROF WILL BRING TSRA CHANCES WEDNESDAY
AFTERNOON THROUGH TUESDAY EVENING...AND AGAIN BY FRIDAY. OTHERWISE
EXPECT WINDS TO REMAIN BELOW 15 KNOTS ACROSS THE LAKE FOR THE FCST
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JMW
AVIATION...VOSS
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
326 AM CDT MON JUL 30 2012
.SHORT TERM...THIS MORNING THROUGH TUESDAY...
LOW PRESSURE NORTH OF LAKE SUPERIOR WILL DRAG AN INSIGNIFICANT
COLD FRONT THROUG DULUTH LATE THIS MORNING AND SEND IT BEYOND OUR
AREA BY THIS EVENING. TROUGHINESS ALOFT WILL STIMULATE SCATTERED
SHOWERS OR THUNDERSTORMS. WITH OUR POSITION IN THE LEFT-ENTRANCE
REGION OF A JET AND DRY AIR AT MID LEVELS...CONVECTIVE DEVELOPMENT
WILL BE UNREMARKABLE. SURFACE HIGH PRESSURE WILL BUILD TOWARD OUR
AREA TONIGHT AND LINGER OVER LAKE SUPERIOR TUESDAY. HEIGHTS ALOFT
WILL QUICKLY BECOME ANTICYCLONIC THIS EVENING WITH ANOTHER UPPER
RIDGE BUILDING TOWARD OUR AREA TUESDAY. EVEN WITH RESIDUAL
MOISTURE ALLOWING CLOUDS...ESPECIALLY NORTH OF DULUTH TUESDAY...
AFTERNOON TEMPERATURES WILL REMAIN WARMER THAN NORMAL AND THE HIGH
HUMIDITY WILL CONTINUE BOTH DAYS.
.LONG TERM...TUESDAY NIGHT THROUGH THE COMING WEEKEND...
THE NORTHLAND WILL BEGIN THE PERIOD IN NORTHWEST FLOW ALOFT DUE TO A
A MID/UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE SOUTHERN AND
WESTERN PLAINS. THIS WILL BRING A SHORTWAVE TROUGH PASSAGE THAT
COULD BRING SHOWERS AND THUNDERSTORMS TO THE NORTHLAND LATE TUESDAY
NIGHT THROUGH THURSDAY. THE RIDGE WILL BEGIN TO GET FLATTENED AFTER
THE MIDDLE OF THE WEEK AS A MORE POTENT SHORTWAVE TROUGH IN SOUTH
CENTRAL CANADA APPROACHES THE REGION. THAT SHORTWAVE TROUGH COULD
BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS TO THE NORTHLAND
FRIDAY THROUGH SATURDAY NIGHT. THE END OF THE FORECAST PERIOD MIGHT
SEE HIGH PRESSURE RETURN TO THE FA. TEMPERATURES THROUGH THE PERIOD
WILL BEGIN ABOVE NORMAL...THEN TRANSITION TO CLOSE TO NORMAL FOR
LATE THIS WEEK AND INTO EARLY NEXT WEEK.
&&
.AVIATION...07/30/06Z ISSUANCE...
LINE OF STORMS WILL MOVE FROM NW TO SE OVER THE NORTHERN HALF OF THE
FA AND AFFECT INL/HIB/DLH. IN THE VCNTY OF THE STORMS...MVFR
CIGS...GUSTY WINDS TO 35 KTS...HEAVY RAIN AND SMALL HAIL IS
POSSIBLE. LATEST HRRR HAS THE STORMS DEPARTING THE INL TERMINAL BY
09Z...HIB BY 11Z AND DLH BY 13Z. THE COLD FRONT WILL FOLLOW QUICKLY
BEHIND THE STORMS AND TURN THE SFC WIND TO THE NW AND BECOME GUSTY
WITH A CLEARING SKY. GUSTY WINDS WILL SUBSIDE NEAR SUNSET. CIGS WILL
BE IN THE VFR RANGE AHEAD OF STORMS AND AFTER FROPA.
&&
.POINT TEMPS/POPS...
DLH 84 61 81 63 / 40 10 10 0
INL 82 57 85 63 / 40 10 10 30
BRD 85 62 85 66 / 20 10 0 10
HYR 86 60 85 61 / 40 10 0 0
ASX 84 63 83 62 / 50 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...EOM
LONG TERM....GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
1207 AM CDT MON JUL 30 2012
.AVIATION...06Z TAFS.
LINE OF STORMS WILL MOVE FROM NW TO SE OVER THE NORTHERN HALF OF THE
FA AND AFFECT INL/HIB/DLH. IN THE VCNTY OF THE STORMS...MVFR
CIGS...GUSTY WINDS TO 35 KTS...HEAVY RAIN AND SMALL HAIL IS
POSSIBLE. LATEST HRRR HAS THE STORMS DEPARTING THE INL TERMINAL BY
09Z...HIB BY 11Z AND DLH BY 13Z. THE COLD FRONT WILL FOLLOW QUICKLY
BEHIND THE STORMS AND TURN THE SFC WIND TO THE NW AND BECOME GUSTY
WITH A CLEARING SKY. GUSTY WINDS WILL SUBSIDE NEAR SUNSET. CIGS WILL
BE IN THE VFR RANGE AHEAD OF STORMS AND AFTER FROPA.
&&
.PREV DISCUSSION... /ISSUED 916 PM CDT SUN JUL 29 2012/
UPDATE...BRIEF BREAK IN THE ACTION ATTM. HOWEVER...THUNDERSTORMS
COMPLEX JUST N OF THE CANADIAN BORDER WILL MOVE INTO NORTHERN MN.
MADE SOME MINOR ADJUSTMENTS AS STORMS SHOULD STAY N OF THE
SOUTHERN TIER OF THE FA UNTIL AFTER MIDNIGHT.
PREV DISCUSSION... /ISSUED 617 PM CDT SUN JUL 29 2012/
AVIATION...00Z TAFS.
UNSTABLE AIR MASS OVER THE FA WITH THUNDERSTORMS ALONG THE CANADIAN
BORDER AND OVER WESTERN LAKE SUPERIOR ATTM. WILL EXPECT TO SEE
ADDITIONAL DEVELOPMENT WITH THE APPROACHING FRONT IN EASTERN ND.
ATTEMPTED TO TIME STORMS THROUGH THE TAF SITES. ANTICIPATE VFR
THROUGH THE FORECAST CYCLE...EVEN IN THE VCNTY OF STORMS AS THEY
REMAIN FAIRLY ELEVATED. LLWS IS POSSIBLE NEAR SUNRISE AT
DLH/HIB/BRD UNTIL ABOUT 15Z WHEN FROPA TURNS THE SFC WIND TO THE
NW AND BECOMES GUSTY.
PREV DISCUSSION... /ISSUED 319 PM CDT SUN JUL 29 2012/
SHORT TERM...
AN H85 TROUGH ASSOCIATED WITH H50 VORT MAX CURRENTLY SEEN ON IR SAT
IMAGERY ROTATING OVER SRN MANITOBA...WILL REMAIN THE FOCUS FOR
SHRA/TSTMS TONIGHT THROUGH MONDAY MORNING. CURRENT RADAR TRENDS
SHOW A WELL ORGANIZED AREA OF STORMS OVER ONTARIO...TRACKING SW
INTO THE MINNESOTA ARROWHEAD. AT THIS TIME THE STRONGEST STORMS
ARE LOCATED TO THE NORTH OF THE INTERNATIONAL BORDER.
HOWEVER...INSTABILITY IS QUITE HIGH WITH THE LATEST SPC
MESO ANALYSIS SHOWING 3000 J/KG MUCAPE AND INCREASING 0-1KM SHEAR
ACROSS THE NRN ZONES.
MODELS ARE IN GOOD AGREEMENT THAT THE DIGGING TROUGH PUSHES INTO
NW MN AROUND 06Z TONIGHT...TRACKING ACROSS NE MN AND OVER LAKE
SUPERIOR THROUGH MONDAY AFTERNOON. A 100 KT H25 CYCLONICALLY
CURVED JET OVER SOUTHERN MN WILL PLACE THE ZONES IN A REGION OF
INCREASING UPPER LEVEL DIVERGENCE OVERNIGHT...PROVIDING ADDITIONAL
SUPPORT FOR CONVECTION. THE BULK OF THE PRECIP WILL BE FOUND NEAR
THE SFC REFLECTION LOW THAT WILL TRACK EAST ALONG THE
INTERNATIONAL BORDER INTO ONTARIO BY MONDAY MORNING. HAVE KEPT
LIKELY POPS GOING ACROSS IRON RAGE/ARROWHEAD REGION WHERE A HALF
TO ONE INCH OF RAIN IS EXPECTED THROUGH MONDAY. DECREASING RAIN
CHANCES ARE FOUND SOUTH OF THE HIGHWAY 2 CORRIDOR. ALTHOUGH
SOUNDINGS SHOW INSTABILITY AND CAPE VALUES REMAIN HIGH IN THE
KBRD/KDLH/KHYR AREAS...THERE REMAINS UNCERTAINTY HOW FAR SOUTH
ALONG THE SFC TROUGH INTO THE DRY AIR STORMS WILL DEVELOP LATE
TONIGHT.
KEPT 20 POPS FOR A FEW ADDITIONAL STORMS MONDAY AFTERNOON ON THE
BACKSIDE OF THE LOW WITH STEEP LAPSE RATES...ELEVATED SBCAPE AND
LINGERING MID LEVEL MOISTURE.
LONG TERM...TUESDAY THROUGH SATURDAY NIGHT...
SURFACE HIGH PRESSURE IN PLACE ACROSS THE UPPER MIDWEST TUESDAY WILL
KEEP MUCH OF THE REGION DRY AND WARM EARLY IN THE EXTENDED PERIOD.
THE NEXT UPPER WAVE AND SFC TROUGH WILL MOVE THROUGH NRN MN ON
WEDNESDAY AND SPREAD SHOWERS AND THUNDERSTORMS ACROSS THE NORTHLAND
THROUGH THE DAY...WITH THE BEST CHANCE OF PRECIP NORTH OF HIGHWAY 2.
THE ACTIVE PATTERN WILL CONTINUE THURSDAY THROUGH SATURDAY AS THE
LARGE UPPER RIDGE OVER THE CENTRAL US SUBSIDES AND QUASI-ZONAL FLOW
SETS UP ACROSS THE NRN PLAINS/UPPER MIDWEST. A SERIES OF FAST MOVING
SHRT WVS WILL TRANSITION THROUGH THE AREA AND BRING SCATTERED
SHOWERS AND STORMS. WILL LIKELY SEE A BREAK IN THE ACTIVE WEATHER
PATTERN INTO THE LATTER HALF OF THE WEEKEND. TEMPERATURES WILL
REMAIN WARM TUESDAY THROUGH THURSDAY WITH HIGHS IN THE LOW TO MID
80S AND OVERNIGHT LOWS IN THE LOWER 60S. BY FRIDAY AND INTO THE
WEEKEND...A SLIGHTLY COOLER AIR MASS MOVES IN FROM THE NORTH AND
ALLOWS DAYTIME HIGHS TO DROP INTO THE LOWER TO MID 70S...WITH NIGHT
TIME LOWS IN THE LOWER TO MID 50S THIS WEEKEND.
&&
.POINT TEMPS/POPS...
DLH 62 83 62 83 / 10 10 10 40
INL 58 84 63 83 / 10 10 10 50
BRD 61 85 65 87 / 0 0 10 30
HYR 63 85 60 85 / 10 10 10 30
ASX 63 83 62 86 / 10 10 10 40
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
335 AM CDT MON JUL 30 2012
.DISCUSSION...
TEMPERATURES AND PCPN CHANCES THE NEXT SEVERAL DAYS WILL PROVIDE THE
MAIN FORECAST CHALLENGES.
HIGHS YESTERDAY ENDED UP A LITTLE HOTTER THAN EXPECTED...ESPECIALLY
CENTRAL AND SOUTHERN ZONES. 00Z KOAX SOUNDING SHOWED MIXING UP TO
AROUND 825 MB AND EVEN A SMALL SUPERADIABATIC LAYER NEAR THE SURFACE.
OVERALL PATTERN IS SIMILAR TO YESTERDAY...BUT SUBTLE DIFFERENCES. AT
300 MB...JETSTREAM STILL STRETCHED FROM NEVADA INTO THE DAKOTAS...
THEN DIVED SOUTHEAST INTO THE OHIO VALLEY. A JET MAX OF AROUND 85 KTS
WAS NOTED OVER NORTHWEST NORTH DAKOTA AT 00Z. THIS APPEARED TO HAVE
SHIFTED INTO EASTERN SOUTH DAKOTA BY 06Z ACCORDING TO LATEST NAM12
AND RAP MODELS. CENTER OF RIDGE AT 700 MB AND 500 MB WAS LOCATED
OVER THE SOUTHERN PART OF THE TEXAS PANHANDLE. MONSOONAL MOISTURE
WAS WORKING ITS WAY NORTH INTO THE ROCKIES...THEN EASTWARD THROUGH
THE CENTRAL PLAINS. A MESOSCALE CONVECTIVE SYSTEM THAT DEVELOPED
OVER NORTHEAST COLORADO LAST EVENING CONTINUED TO MOVE EAST
ACROSS NORTHERN KANSAS AND SOUTHERN NEBRASKA EARLY THIS MORNING.
WILL MAINTAIN AREAL COVERAGE WORDING FOR OUR SOUTHERN ZONES INTO
MID MORNING...WHEN MCS MAY START TO WEAKEN. OTHERWISE...WILL HAVE
A SLIGHT CHANCE OF THUNDERSTORMS MOST AREAS UNTIL 18Z THEN
MAINTAIN LOW POPS MUCH OF THE FORECAST AREA THIS AFTERNOON. FELT
CLOUDS MAY HOLD HIGHS BACK SOME TODAY...SO WENT WITH MID TO UPPER
90S NORTH AND LOWER TO MID 90S SOUTH. SOME STORMS COULD POP UP
LATE THIS AFTERNOON OR EARLY EVENING NEAR A FRONTAL BOUNDARY THAT
PUSHES DOWN FROM THE NORTHERN PLAINS.
CENTER OF THE 500 MB RIDGE LOCATION DOES NOT CHANGE MUCH THROUGH
MID WEEK...AND SO MID LEVEL MOISTURE WILL BE ONE THING TO KEY ON
FOR CONVECTIVE POTENTIAL. HAVE A MAINLY DRY FORECAST GOING FROM
LATE THIS EVENING INTO TUESDAY EVENING. 00Z ECMWF SHOWS ANOTHER
PRETTY GOOD INCREASE IN 700 MB DEWPOINTS INTO THE AREA FOR LATE
TUESDAY NIGHT AND WEDNESDAY...SO SPREAD THUNDERSTORM CHANCES FROM
WEST TO EAST DURING THAT TIME.
LATER IN THE WEEK...A FAIRLY STRONG SHORTWAVE TROUGH DIGS OVER THE
NORTHERN ROCKIES THURSDAY...THEN MOVES INTO THE NORTHERN PLAINS BY
FRIDAY NIGHT. THIS SHOULD PUSH A FRONT THROUGH THE REGION FRIDAY
NIGHT OR SATURDAY. TEMPERATURES AHEAD OF THE FRONT SHOULD TOP OUT
MAINLY IN THE 90S TO AROUND 100 THROUGH THE WEEK. HIGHS BY SATURDAY
AND SUNDAY COULD COOL TO THE UPPER 80S/LOWER 90S. ALTHOUGH THE
FRONTAL PASSAGE SUGGESTS A DECENT CHANCE OF PCPN...MODELS DO NOT
AGREE ON QPF...SO WILL NOT GET TOO OPTIMISTIC AT THIS POINT.
MILLER
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...KOFK.
VFR CONDS ARE EXPECTED THROUGH THE PERIOD. MID AND HIGH LVL CLOUDS
HAVE BEEN INCREASING AT ALL THE TAF SITES AND THIS WILL CONT THROUGH
THE OVERNIGHT HOURS. SCT SHRA TO THE WEST ASSOCIATED WITH A WEAK
SHRTWV TROUGH WILL CONT TO ADVANCE EWD AND WL INCLUDE SOME VC
SHOWERS AT LNK FOR LATE TONIGHT AND INTO MON MRNG...BUT THIS WILL
LIKELY REMAIN S OF OMA/OFK. OTHERWISE LIGHT WINDS ARE EXPECTED THRU
THE PERIOD WITH WEAK SFC RIDGE OVER THE AREA.
BOUSTEAD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
316 AM EDT MON JUL 30 2012
.SYNOPSIS...
A STATIONARY FRONT OVER EASTERN NORTH CAROLINA WILL WEAKEN TODAY. A
SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE SOUTHEAST THROUGH THE
REGION THROUGH WEDNESDAY. UPPER LEVEL HIGH PRESSURE BUILDS OVER THE
REGION FROM THE WEST LATER IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
TODAY...
WATER VAPOR IMAGERY THIS MORNING CONTINUES TO SHOW CONVECTIVELY
ENHANCED UPPER LEVEL DISTURBANCES MOVING SOUTHEAST OUT OF THE
UPPER MIDWEST...BETWEEN AN UPPER RIDGE OVER THE INNER MOUNTAIN
WEST AND A BROAD TROUGH OVER THE EASTERN US. THE MOST NOTABLE
DISTURBANCE APPROACHING THE CAROLINAS IN THE SHORT TERM IS
CURRENTLY NEAR THE IN/KY BORDER. THIS DISTURBANCE IS FORECAST TO
DEEPEN THE UPPER TROUGH AS IT SWINGS ACROSS NORTHERN GA AND SC
LATER TODAY. MODELS INDICATE THE LOW LEVEL WINDS WILL BACK IN
RESPONSE TO THE DEEPENING TROUGH...LEADING TO WEAK WARM
ADVECTION/VEERING PROFILE AND CONVECTIVE INITIATION ALONG A
STALLED OUT THE COLD FRONT OVER THE COASTAL PLAIN. WITH DEWPOINTS
HAVING RECOVERED INTO THE LOWER 70S AND PW UP TO 2 INCHES EAST OF
THE BOUNDARY BUT WEAK MID LEVEL LAPSE RATES...A MODEL CONSENSUS
GIVES 1000 TO MAYBE 1500 J/KG OF MLCAPE OVER THE COASTAL PLAIN AND
LESS TO THE WEST. THE WEAK CINH ON THE 00Z KMHX RAOB SHOULD ERODE
QUICKLY WITH HEATING LATER THIS MORNING AND HRRR SHOWS ISOLATED
CONVECTION AS EARLY AS 15-16Z AROUND SAMPSON/WAYNE COUNTY. WE WILL
SHOW POPS INCREASING WESTWARD DURING THE AFTERNOON AS THE
SOUTHEASTERLY FLOW AND ANY OUTFLOW OF SHOWERS/STORMS WILL HELP
SHIFT THE REMNANTS OF THE FRONT AND LOW LEVEL FOCUS WESTWARD.
HOWEVER...BASED ON THE 00Z KGSO RAOB AND FORECAST
SOUNDINGS...SHOWERS AND STORMS WILL ENCOUNTER A MORE PRONOUNCED
MID LEVEL CAP OVER THE WESTERN PIEDMONT..SO WE WILL KEEP POPS AT
SLIGHT CHANCE OVER MUCH OF THE WESTERN CWA. DEEP LAYER FLOW WILL
BE WEAK TODAY..SO ANY HAZARDOUS WEATHER WILL BE FROM PULSING
STRONGER STORMS AND AN ISOLATED PRECIP LOADED DOWNBURST.
GUIDANCE CONTINUES TO BE VERY CONSISTENT WITH HIGHS RIGHT AT
NORMAL VALUES...88-90
TONIGHT...
MODELS SHOW A WEAK SURFACE WAVE DEVELOPING OVER THE COASTAL PLAIN
BENEATH WEAK HEIGHT FALLS ALOFT. A RELATIVELY STRONG 35KT 850MB JET
IS FORECAST TO DEVELOP OFFSHORE...WHICH IS WHERE MOST OF THE
OVERNIGHT SHOWERS AND STORMS WILL BE FOCUSED. THUS...THERE SHOULD BE
LITTLE IMPACTS ON SENSIBLE WEATHER FOR CENTRAL NC..OTHER THAN A
LIGHT NORTHEASTERLY WIND AND POSSIBLY SOME PATCHY STRATUS BY TUESDAY
MORNING. LOWS IN THE LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 310 AM MONDAY...
THE TRAIN OF UPPER LEVEL DISTURBANCES FROM THE UPPER MIDWEST TO THE
SOUTHERN APPALACHIANS WILL CONTINUE ON TUESDAY...AS MODELS SHOW A
80KT SPEED MAX AND ASSOCIATED VORTICITY DIVING TOWARD WESTERN NC AND
UP STATE SC BY EARLY AFTERNOON. MODELS INDICATE SOME CONVECTION OVER THE
MOUNTAINS AND ALONG THE COAST BY LATE MORNING...BUT A SHARPENING OF
THE MID/UPPER LEVEL TROUGH AXIS ASSOCIATED WITH THE AFOREMENTIONED UPPER
DISTURBANCE SHOULD LEAD TO SCATTERED SHOWERS AND STORMS OVER THE
WEST BY EARLY AFTERNOON. THE SEVERE THREAT OVER CENTRAL NC IS
SOMEWHAT UNCERTAIN AS THE STRONGER EFFECTIVE DEEP LAYER SHEAR WILL
LIKELY LIE TO THE SOUTHWEST OF THE CWA IN CLOSER PROXIMITY TO THE
BELT OF STRONGER MID LEVEL FLOW AND A FAIRLY STRONG SURFACE REFLECTION.
HOWEVER...IF STORMS CAN GET GOING OVER THE WESTERN AND SOUTHERN
PIEDMONT...THEN THERE WOULD BE A LOWER END THREAT OF DAMAGING WIND
GUSTS WITH STRONGER STORMS AND/OR MERGING COLD POOLS. WE WILL SHOW
HIGHEST POPS SHIFTING FROM THE SOUTHWEST TO EASTERN AREAS DURING THE
AFTERNOON AND EVENING...TRENDING DOWN TO A SLIGHT CHANCE OVERNIGHT.
WITH WEAK FLOW OVER CENTRAL NC DURING THE DAY AND NEAR MAXIMUM
INSOLATION...HIGHS SHOULD TOP OUT IN THE 86-90 RANGE BASED ON A
FORECAST 12Z LOW LEVEL THICKNESS OF 1405M. LOWS TUESDAY NIGHT ONCE
AGAIN IN THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT...A MID-LEVEL TROUGH REMAINS OVER
CENTRAL NORTH CAROLINA...AND BOTH THE GFS AND THE NAM FORECAST AN
850MB TROUGH MOVING GRADUALLY WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA THROUGH THE EVENING. THE NAM IS FARTHER SOUTH IN THE TRACK
OF THE 850MB WAVE AS COMPARED TO THE GFS...THOUGH BOTH FORECAST A
WEAK SURFACE WAVE MOVING OVER OR NEAR THE SANDHILLS AND THE SOUTHERN
COASTAL PLAIN AND TOWARD THE COAST WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT. WITH 850MB THETA-E RIDGING FORECAST BY THE GFS
DURING THE DAY...AND THE APPROACH OF A WEAK 50KT JETLET AT 250MB
FROM THE NORTHWEST AIDING IN UPPER DIFFLUENCE...EXPECT AT LEAST
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING OVER MUCH OF CENTRAL
NORTH CAROLINA DURING THE DAY. THE GREATER CHANCES WILL BE TOWARD
INTERSTATE 95...IN VICINITY OF DEEPER MOISTURE WHERE PRECIPITABLE
WATER VALUES WILL BE AROUND 1.75 INCHES...AS COMPARED TO 1.5 INCHES
TOWARD THE YADKIN RIVER. IT SHOULD BE NOTED THAT THE GFS BUFR
SOUNDINGS ARE STABLE IN COMPARISON TO THE NAM BUFR SOUNDINGS...
DESPITE THE FACT THE GFS HAS THE 850MB TROUGH FARTHER NORTH AND ITS
QPF IS GREATER THAN THE NAM. 0-6KM SHEAR IS AROUND 25KT...NOT TOO
BAD COMPARED TO MANY RECENT DAYS...AND MLCAPE IS FORECAST AROUND
2000J/KG DURING WEDNESDAY AFTERNOON. ALTHOUGH A SURFACE WAVE IS
FORECAST TO MOVE OVER OR VERY CLOSE TO THE AREA...ESPECIALLY TO THE
SOUTHEAST...0-3KM HELICITY VALUES ARE FAIRLY SMALL OVER CENTRAL
NORTH CAROLINA...ONLY RISING TO NEAR 100M2/S2 TOWARD AND OFFSHORE OF
THE CAROLINA COAST. IF ANY ISOLATED SEVERE STORMS WOULD DEVELOP...
CURRENT THOUGHTS ARE THE BETTER CHANCE WOULD BE FROM ABOUT U.S. 1
EASTWARD.
BEHIND THE SURFACE AND 850MB WAVES...THE OVERALL AIR MASS DRIES ON
BUFR SOUNDINGS OVERNIGHT WEDNESDAY. HOWEVER...BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS SHOW SLIGHT LAYER COOLING ABOVE 700MB...
AND THE GFS FORECASTS FAIRLY ROBUST POTENTIAL VORTICITY ON THE 1.5
PVU SURFACE MOVING INTO CENTRAL NORTH CAROLINA LATE AT NIGHT IN THE
NORTHWEST FLOW ALOFT. POSSIBLY FOR THESE REASONS BOTH THE NAM AND
GFS FORECAST LIGHT QPF OVER THE PIEDMONT OVERNIGHT...AND WILL
MAINTAIN A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM DUE TO THE
SLIGHT POTENTIAL FOR WHAT SHOULD BE ELEVATED...DEEP CONVECTION.
FOLLOWED A BLEND OF THE MET AND MAV MOS AND THE BIAS CORRECTED MOS
GUIDANCE FOR WEDNESDAY WITH HIGHS AROUND 90...AND EXPECT OVERNIGHT
LOWS WEDNESDAY AROUND 70.
FROM THURSDAY THROUGH THE END OF THE WEEK...LONG-TERM GUIDANCE
CONSENSUS IS FOR HEIGHTS TO INCREASE OVER AND AROUND CENTRAL NORTH
CAROLINA...AS RIDGING BUILDS EAST FROM THE PLAINS AND...PROBABLY
MORE SO...INFLUENCED BY RIDGING OVER THE NORTH ATLANTIC. DESPITE THE
RIDGING ALOFT...RELATIVE TROUGHINESS SHOULD REMAIN IN THE FLOW ALOFT
OVER THE MID-ATLANTIC. THE RESULT SHOULD BE LIGHT...BUT BROADLY
DIFFLUENT FLOW ALOFT. 1000-850MB THICKNESSES SHOULD WARM...LEADING
TO HIGHS MOST DAYS IN THE LOWER TO MID 90S...AND A FEW UPPER 90S
CANNOT BE COMPLETELY RULED OUT ESPECIALLY OVER THE SOUTHWEST
PIEDMONT...SANDHILLS...AND U.S. 1 CORRIDOR. CURRENTLY FORECAST DEW
POINTS LEAD TO HEAT INDICES AT THE END OF THE WEEK BETWEEN 100 AND
105 DEGREES...HIGHEST SATURDAY AND SUNDAY.
ALL OF THE LONG-TERM GUIDANCE SUGGESTS PERIODIC PASSAGE OF WEAK
MID-LEVEL DISTURBANCES IN THE BROADLY DIFFLUENT WEST-NORTHWEST FLOW
ALOFT. THE TIMING OF THESE...AND HOW THEY ARE INFLUENCED BY DEEP
CONVECTION UPSTREAM...IS DIFFICULT TO FORECAST IN THE LONG TERM. THE
COMBINATION OF SEA BREEZE AND PIEDMONT TROUGH INFLUENCES FOR
LOW-LEVEL LIFT...AND MID-LEVEL SHORTWAVES IN A MODESTLY MOIST AND
UNSTABLE AIR MASS...SHOULD RESULT IN ISOLATED TO SCATTERED CHANCES
FOR SHOWERS AND THUNDERSTORMS...GENERALLY DIURNALLY...EACH DAY. THE
LATEST GFS FORECASTS PRECIPITABLE WATER VALUES AT OR BELOW 1.5
INCHES ON THURSDAY...WHICH IS AT OR BELOW NORMAL FOR THIS TIME OF
YEAR AND COULD RESULT IN A LARGELY DRY DAY. PRECIPITABLE WATER
VALUES GRADUALLY CLIMB FRIDAY THROUGH THE WEEKEND ON THE GFS. NOT
BEING A FAN OF REMOVING SMALL CHANCES OF PRECIPITATION ESPECIALLY IN
THE HUMIDITY OF SUMMER...WILL CONTINUE THE OVERALL TREND AT THE END
OF THE WEEK OF ISOLATED CHANCES FOR A SHOWER OR THUNDERSTORM IN MOST
AREAS EXCEPT CHANCES TOWARD THE COASTAL PLAIN CLOSER TO ANY SEA
BREEZE AND WHERE MOISTURE WILL BE SOMEWHAT GREATER. DURING THE
WEEKEND...AND ESPECIALLY BY SUNDAY...AS MOISTURE GRADUALLY INCREASES
AND DUE TO GROWING SYNOPTIC SCALE UNCERTAINTY...WILL FORECAST BROAD
CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH CAROLINA.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
AS OF 150 AM MONDAY...
ANY FOG THIS MORNING SHOULD BE PATCHY AND MAINLY CONFINED TO THE
EASTERN PIEDMONT AND COASTAL PLAIN. CONFIDENCE IS ONLY HIGH ENOUGH
TO CARRY A PERIOD OF MVFR VSBY AT KRDU/KFAY/KRWI...WITH A SHORTER
PERIOD OF MORE DENSE FOG POSSIBLE AT KRWI BY 12Z.
THUNDERSTORMS WILL BE POSSIBLY BY EARLY AFTERNOON FROM KRDU TO THE
SOUTH AND EAST..POSSIBLY SPREADING WEST TOWARD THE TRIAD LATER IN
THE AFTERNOON/EVENING. HOWEVER..COVERAGE SHOULD BE TOO LOW FOR
MENTION AT ANY TAF SITE AT THIS TIME.
OUTLOOK...
STORMS ARE EXPECTED TO BE MORE NUMEROUS ON TUESDAY AS AN UPPER
LEVEL TROUGH CROSSES THE AREA. A TYPICAL THREAT OF SUMMERTIME
AFTERNOON AND EVENING THUNDERSTORMS AND EARLY MORNING FOG AND
STRATUS WILL THEN CONTINUE THROUGH THE REMAINDER OF THE WEEK..
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...SMITH
LONG TERM...DJF
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
844 PM EDT SUN JUL 29 2012
.SYNOPSIS...
A COLD FRONT ACROSS THE EASTERN CAROLINAS AND VIRGINIA WILL LINGER
AND GRADUALLY DISSIPATE THROUGH TUESDAY. A SERIES OF UPPER LEVEL
DISTURBANCES WILL MOVE SOUTHEASTWARD ACROSS THE REGION ON MONDAY AND
TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 235 PM SUNDAY...
DIFFUSE COLD FRONT HAS DRIFTED SOUTH SLIGHTLY DURING THE PAST FEW
HOURS WITH NORTHERLY WINDS AT KFAY AND KGSB. DEW POINTS BEHIND THE
FRONT CONTINUE TO FALL TO AROUND 60 IN THE TRIAD WITH MUCH MORE
MOIST DEW POINTS IN THE LOWER 70S ACROSS THE COASTAL PLAIN. MORNING
RAOBS DEPICTED A MUCH DRIER AIR MASS TO THE WEST WITH A PRECIPITABLE
WATER VALUES OF AROUND 0.8 TO 1.1 INCHES AT KRNK/KGSO
RESPECTIVELY WHILE A PRECIPITABLE WATER OF 1.8 INCHES WAS NOTED
AT KMHX. RECENT VISIBLE SATELLITE IMAGERY DEPICTS A FAIR AMOUNT OF
CUMULUS BUT LIMITED VERTICAL GROWTH GIVEN THE WEAK SUBSIDENCE IN
THE WAKE OF A DEPARTING MID LEVEL WAVE AND DRYING ALOFT.
THE LIMITED THREAT OF CONVECTION THIS AFTERNOON AND EVENING WILL
REMAIN FOCUSED ACROSS THE COASTAL PLAIN...THE SOUTHERN PIEDMONT AND
THE SANDHILLS IN THE VICINITY OF THE SURFACE FRONT...IN A REGION OF
THE DEEPER MOISTURE AND NEAR THE UPPER LEVEL TROUGH AXIS. MOST
CONVECTION ALLOWING MODELS SUGGEST THAT SOME CONVECTION IS POSSIBLE
IN THE EAST TODAY BUT RECENT RUNS OF THE HRRR DOWNPLAY THE COVERAGE
SIGNIFICANTLY. INSTABILITY WILL BE LIMITED TODAY ACROSS THE WEST AND
NORTH WITH MLCAPE VALUES AROUND 500 J/KG...FURTHER EAST IN THE
COASTAL PLAIN MLCAPE VALUES MAY REACH AS HIGH AS 1500 J/KG. MID
LEVEL LAPSE RATES REMAIN RATHER ANEMIC WITH WEAK LOW AND MID LEVEL
FLOW RESULTING IN BULK SHEAR VALUES OF AROUND 15 KNOTS OR LESS. GIVEN
THE DRY AIR ALOFT...DCAPE VALUES CURRENTLY RANGE AROUND 1300 J/KG
SUGGESTING AT LEAST SOME POTENTIAL FOR STRONG DOWNBURST WINDS WITH A
WELL DEVELOPED CELL. GIVEN THIS ENVIRONMENT...OVERALL STORM STRENGTH
AND ORGANIZATION SHOULD BE LIMITED. PRECIPITATION CHANCES DIMINISH
DURING THE EVENING WITH JUST A LIMITED THREAT OF SHOWERS OR A
THUNDERSTORM OVERNIGHT ACROSS THE EAST AND SOUTH. LOWS TONIGHT
SHOULD DROP INTO THE 67 TO 75 RANGE IN AGREEMENT WITH GUIDANCE.
-BLAES
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 310 PM SUNDAY...
A SHORT WAVE TROUGH ACROSS WISCONSIN/MINNESOTA/IOWA ON SUNDAY
AFTERNOON ASSOCIATED WITH A 40 KNOT MID LEVEL JET WILL DROP
SOUTHEAST INTO AND SHARPEN THE EASTERN UNITED STATES ON MONDAY AN
MONDAY NIGHT. THIS FEATURE SHOULD MOVE ACROSS THE SOUTHERN
APPALACHIANS DURING MONDAY AFTERNOON WHICH WILL SUPPORT THE
DEVELOPMENT OF SCATTERED CONVECTION ACROSS THE CAROLINAS. THE MAIN
PUSH OF THE SHORTWAVE WILL MOVE ACROSS GEORGIA AND SOUTH CAROLINA
AND RESULT IN A SLIGHT COOLING OF TEMPERATURES ALOFT IN CENTRAL
NORTH CAROLINA BUT A GENERALLY WEAK FLOW ALOFT. THE COLD FRONT
DRAPED ACROSS THE SOUTHEASTERN PORTION OF NORTH CAROLINA SUNDAY
AFTERNOON SHOULD MIGRATE NORTHWEST EARLY MONDAY AND PROVIDE A
FOCUS FOR CONVECTION ACROSS THE EASTERN PIEDMONT AND COASTAL PAIN.
MID LEVEL LAPSE RATES STEEPEN ON MONDAY AFTERNOON AND MLCAPE
VALUES SHOULD RANGE BETWEEN 1000 AND 2000 J/KG WHILE BULK SHEAR
VALUES RANGE AROUND 15 KNOTS IN CENTRAL NORTH CAROLINA.
PRECIPITABLE WATER VALUES INCREASE SOMEWHAT ON MONDAY AND RANGE
FROM 1.4 IN THE TRIAD TO NEAR 2 INCHES IN THE COASTAL PLAIN. THESE
PARAMETERS SUGGEST THE PRIMARY SEVERE WEATHER THREAT ON MONDAY
AFTERNOON AND EVENING WILL BE DAMAGING WINDS FROM WET DOWNBURSTS
AND AN ISOLATED MINOR FLOODING POTENTIAL. LOW LEVEL THICKNESSES
WILL CLIMB TO BETWEEN 1410 AND 1420 METERS MONDAY AFTERNOON...
SUGGESTING HIGHS IN THE 88 TO 92 RANGE. SCATTERED CONVECTION
SHOULD PERSIST INTO MONDAY EVENING BUT GENERALLY DIMINISH
OVERNIGHT. LOW TEMPERATURES SHOULD RANGE BETWEEN 68 AND 72
DEGREES. -BLAES
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 315 PM SUNDAY...
TUESDAY AND TUESDAY NIGHT:
THE SYNOPTIC PATTERN OVER THE MID ATLANTIC AND THE CAROLINAS ON
TUESDAY AND TUESDAY NIGHT WILL BE CHARACTERIZED BY TROUGHING
ALOFT...ON THE EASTERN PERIPHERY OF AN UPPER LEVEL RIDGE CENTERED
OVER THE CENTRAL CONUS... WITH SMALL AMPLITUDE DISTURBANCES
PROGRESSING TOWARD THE AREA IN NORTHWEST FLOW ALOFT. GIVEN
TROUGHING ALOFT IN THE PRESENCE OF A SEASONABLY MOIST AND UNSTABLE
AIR MASS...EXPECT ABOVE NORMAL CHANCES FOR SHOWERS AND STORMS...
PRIMARILY DURING THE AFTERNOON AND EVENING HOURS. HOWEVER THE
TIMING... LOCATION AND COVERAGE OF CONVECTION IS STILL UNCERTAIN
AND WILL HIGHLY DEPEND ON THE EVOLUTION OF SMALL AMPLITUDE
DISTURBANCES EXPECTED TO PROGRESS TOWARD THE REGION IN NORTHWEST FLOW
ALOFT. WITH THE ABOVE IN MIND...WILL INDICATE A 50 PERCENT CHANCE
OF SHOWERS OR THUNDERSTORMS EVERYWHERE ON TUESDAY...WITH CHANCES
DECREASING TO 20 PERCENT AFTER MIDNIGHT. HIGHS ON TUESDAY SHOULD BE
NEAR NORMAL (UPPER 80S TO LOWER 90S) BASED ON 1000 TO 850 MILLIBAR
THICKNESSES IN VICINITY OF 1415 METERS. LOWS WEDNESDAY MORNING SHOULD
ALSO SHOULD BE NEAR NORMAL (UPPER 60S TO LOWER 70S). THE PRIMARY
UNCERTAINTY WITH TEMPERATURES WILL BE THE TIMING AND LOCATION OF
CONVECTION AND CLOUD COVER ASSOCIATED WITH THE REMNANTS OF
CONVECTION OVER OR UPSTREAM OF THE AREA. AS MENTIONED IN THE SPC
DAY 3 CONVECTIVE OUTLOOK...THERE MAY BE AN INCREASED THREAT FOR
SEVERE THUNDERSTORMS TUESDAY AFTERNOON AND EVENING...THOUGH
UNCERTAINTY PERSISTS. MODEL GUIDANCE IS INDICATING RICH BOUNDARY
LAYER MOISTURE TUESDAY AFTERNOON AND EVENING...FOCUSED SHORT WAVE
ENERGY DIGGING TOWARD THE AREA IN VICINITY OF PEAK HEATING...
STRENGTHENING MID AND UPPER LEVEL FLOW...DEEP LAYER SHEAR...AND A
POTENTIAL FOR MODESTLY STEEP (6 TO 7 C/KM) MID LEVEL LAPSE RATES
ADVECTING SOUTHEAST TO THE SOUTHERN APPALACHIANS AND PORTIONS OF
THE MID ATLANTIC AND THE CAROLINAS VIA NORTHWEST FLOW ALOFT.
WEDNESDAY THROUGH SUNDAY:
THE SYNOPTIC PATTERN OVER THE CAROLINAS AND MID ATLANTIC WEDNESDAY
THROUGH SUNDAY WILL BE CHARACTERIZED INITIALLY (WEDNESDAY AND
THURSDAY) BY NORTHWEST FLOW ALOFT... TRANSITIONING (FRIDAY/
SATURDAY/ SUNDAY) TO WESTERLY FLOW ALOFT AS THE UPPER LEVEL RIDGE
OVER THE CENTRAL CONUS FLATTENS AND EXTENDS EAST TOWARD THE
CAROLINAS/SOUTHEAST. PRECIPITATION CHANCES...I.E. THE TIMING...
LOCATION AND COVERAGE OF CONVECTION...WILL BE HIGHLY DEPENDENT ON
THE EVOLUTION OF SMALL AMPLITUDE DISTURBANCES PROGRESSING
SOUTHEAST FROM THE UPPER MIDWEST/CENTRAL MISSISSIPPI RIVER VALLEY
INTO THE MID ATLANTIC AND CAROLINAS ON WEDNESDAY AND THURSDAY...
WITH A POTENTIAL FOR ENHANCED COVERAGE AND SEVERE WEATHER.
THOUGH UNCERTAINTY INCREASES BY NEXT WEEKEND... CONVECTION MAY
BECOME MORE ISOLATED IN NATURE FRIDAY/SATURDAY/SUNDAY AS THE MAIN
BELT OF WESTERLIES SHIFTS FURTHER NORTH INTO THE MID ATLANTIC AND
FORCING BECOMES INCREASINGLY CONFINED TO THE PIEDMONT TROUGH/
SEABREEZE...MORE TYPICAL FOR THIS TIME OF YEAR. WILL INDICATE
CHANCES FOR SHOWERS AND THUNDERSTORMS SLIGHTLY ABOVE CLIMATOLOGY
IN THE 30 TO 40 PERCENT RANGE WEDNESDAY AND THURSDAY...WITH A
SLIGHT CHANCE (20 PERCENT) PERSISTING DURING THE OVERNIGHT HOURS.
ON FRIDAY/SATURDAY/SUNDAY WILL TREND CLOSER TOWARD CLIMATOLOGY
WITH REGARD TO CHANCES FOR CONVECTION. TEMPERATURES WILL PRIMARILY
DEPEND ON THE EVOLUTION OF CONVECTION AND ASSOCIATED CLOUD COVER
WEDNESDAY AND THURSDAY...WITH 1000 TO 850 MILLIBAR THICKNESSES
SUGGESTING HIGHS AND LOWS NEAR NORMAL...IN THE UPPER 80S TO LOWER
90S AND UPPER 60S TO LOWER 70S. SLIGHTLY ABOVE NORMAL TEMPERATURES
(LOWER TO MID 90S) WILL BE POSSIBLE FRIDAY/SATURDAY/SUNDAY GIVEN A
RELATIVELY DECREASED POTENTIAL FOR CONVECTION AND RISING HEIGHTS
ALOFT. -VINCENT
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AS OF 840 PM...
ISOLATED SHOWERS OR A THUNDERSTORM THIS EVENING... SHOULD
DISSIPATE BEFORE MIDNIGHT. FOG DEVELOPING BEFORE DAWN WITH MVFR
VISIBILITIES. FOG DISSIPATING SHORTLY AFTER SUNRISE.
SCATTERED THUNDERSTORMS ARE POSSIBLE MAINLY EAST OF HIGHWAY ONE
MONDAY AFTERNOON AND EVENING WITH A PERIOD OF MVFR/IFR
FOG AND STRATUS POSSIBLE EARLY TUESDAY MORNING. MORE NUMEROUS
THUNDERSTORMS ARE EXPECTED TUESDAY AFTERNOON AND EVENING. A MORE
TYPICAL THREAT OF SUMMERTIME AFTERNOON AND EVENING THUNDERSTORMS
AND EARLY MORNING FOG AND STRATUS CONTINUES ON WEDNESDAY AND
THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
NEAR TERM...BLAES
SHORT TERM...BLAES
LONG TERM...VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1133 PM CDT SUN JUL 29 2012
.DISCUSSION...LATEST WATER VAPOR IMAGERY SHOWS A WESTERLY FLOW
INTO NORTH DAKOTA WITH A SHORTWAVE SEEN OVER FAR SOUTH CENTRAL
MONTANA. WEAK ECHOES BEING SUPPORTED WITH THIS PER REGIONAL RADAR.
THE HRRR DOES HOLD TOGETHER SOME OF THE PRECIPITATION AS IT SHIFTS
EAST OVERNIGHT WITH THE ADVANCING SHORTWAVE. WILL MENTION ISOLATED
THUNDERSTORMS FAR SOUTHWEST TO RIGHT ALONG THE SOUTHERN BORDER
OVERNIGHT AS THERE HAS BEEN SHOWERS DEVELOPING OVER SIOUX AND
EMMONS COUNTIES LAST COUPLE OF HOURS. THESE SHOWERS HAVE BEEN
ADVANCING SOUTHEAST INTO SOUTH DAKOTA. THE HRRR PICKS UP ON THIS
AND THUS WILL MAINTAIN THE ISOLATED THUNDERSTORMS OVERNIGHT FAR
SOUTHEAST. WITH CLEAR SKIES IN THE NORTH...TEMPERATURES COOLING A BIT
QUICKER AND HAVE ADJUSTED OVERNIGHT LOWS WITH WIDESPREAD MID/UPPER
50S. MONDAY STILL LOOKS VERY WARM AND DRY PER 00Z DATA. REST OF
FORECAST REMAINS ON TRACK.
&&
.AVIATION...HIGH PRESSURE WAS BUILDING INTO THE STATE FROM
MONTANA AND SASKATCHEWAN. A TROUGH AND COLD FRONTAL BOUNDARY
ACROSS SOUTHEAST NORTH DAKOTA THROUGH NORTH CENTRAL SOUTH DAKOTA
WILL BE THE FOCUS FOR SHOWERS AND THUNDERSTORMS ACROSS FAR
SOUTHERN AND EASTERN NORTH DAKOTA SUNDAY NIGHT. ALL TAF SITES WILL
BE VFR THROUGH THE TAF PERIOD AND THUNDERSTORMS WILL REMAIN SOUTH
OF ALL AERODROMES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KS
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
126 AM EDT MON JUL 30 2012
.SYNOPSIS...
A CHANCE FOR SCATTERED SHOWERS AND THUNDERSTORMS BEGINS ON MONDAY
AS AN UPPER DISTURBANCE WILL DROP SOUTHEAST ACROSS THE AREA. A
WEAK COLD FRONT WILL THEN PUSH THROUGH THE AREA ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SURFACE HIGH PRESSURE REMAINS IN PLACE OVER THE SOUTHERN GREAT
LAKES AND MIDDLE OHIO VALLEY REGIONS. NORTHWESTERLY FLOW ALOFT
WILL CONTINUE TO SPREAD IN A FEW MID AND HIGH CLOUDS...GRADUALLY
THICKENING SLIGHTLY GOING INTO TOMORROW. THE EARLIER ADJUSTMENTS
TO A DRY FORECAST STILL APPEAR TO BE THE BEST COURSE OF ACTION.
LOW TEMPS WERE ADJUSTED SLIGHTLY BASED PRIMARILY ON THE MET
NUMBERS (RECENT RAP RUNS LOOK WELL TOO WARM...GIVEN THAT IT IS
ALREADY IN THE UPPER 60S IN OUTLYING AREAS).
PREVIOUS DISCUSSION >
7PM UPDATE...MADE ONLY MINOR DEWPOINT AND CLOUD TWEAKS OVERNIGHT.
PREVIOUS DISCUSSION...EARLIER MODEL RUNS WERE PUSHING A WET SOLUTION
IN HANDLING APPROACHING WEAK S/WV PUSHING SSE ACROSS INDIANA
OVERNIGHT. UPDATED RUNS...INCLUDING THE HRRR/WRF/ECMWF
SOLUTIONS...THE DRY BOUNDARY LAYER AND NO STRONG FORCING MECHANISM
HAVE PROMPTED DECISION TO KEEP PRECIP OUT OF AREA AS A RESULT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/...
AS THE SHORT WAVE DROPS THROUGH AREA ON MONDAY...AGAIN SOME
DIFFERENCES IN PRECIP PLACEMENT AND COVERAGE. HAVE KEPT ONLY A 20
POP ACROSS THE AREA DUE TO DRIER BOUNDARY LAYER ONLY WEAK FORCING
AND DIMINISHED COVERAGE AS A RESULT. GFS HAD BEEN VERY AGGRESSIVE
WITH THE PRECIP...BUT IS AGAIN HANDLING SURFACE DEWPOINTS
POORLY...SO HAVE NOT CONSIDERED THIS SOLUTION. 00Z ECMWF RUN HAD
ALSO BEEN MORE AGGRESSIVE WITH PRECIP BUT 12Z RUN CAME IN MORE
CONSERVATIVE...GIVING FURTHER SUPPORT FOR SLIGHT CUTS IN PRECIP
CHANCES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HAVE TAKEN A BLEND OF NCEP/HPC AND THE 00Z ECMWF FOR THE EXTENDED
FORECAST AS THEY OFFER THE BEST SOLUTION AND HAVE CONTINUITY.
A WEAK COLD FRONT IS FORECAST TO SLIDE INTO THE REGION ON TUESDAY
AND WITH A S/WV DROPPING DOWN IN THE NORTHWEST FLOW ALOFT...IT
APPEARS THAT THERE WILL BE A CHANCE OF SHOWERS/STORMS TUESDAY INTO
TUESDAY EVENING. IT STILL LOOKS LIKE A SURFACE RIDGE WILL THEN BUILD
INTO THE REGION BY WEDNESDAY NIGHT AND PERSIST ACRS THE AREA INTO
THURSDAY. UPR LVL FLOW BRIEFLY TRANSITIONS MORE TO A ZONAL PATTERN
ON FRIDAY...AND WITH WEAK RETURN SFC FLOW AROUND DEPARTING HIGH AND
PERHAPS AN EMBEDDED DISTURBANCE RIPPLING ALOFT...HAVE KEPT A LOW
CHANCE FOR SHOWERS/STORMS. A STRONGER S/WV AND COLD FRONT IS POISED
TO AFFECT THE REGION SATURDAY INTO SATURDAY NIGHT...OFFERING AN
ENHANCED CHANCE OF SHOWERS AND STORMS. THE COLD FRONT IS PROGGED TO
SLIDE SE OF THE AREA ON SUNDAY...BRING AN END TO THE PCPN AND
ALLOWING DRIER AIR TO BUILD BACK INTO THE AREA ONCE AGAIN.
TEMPERATURES ON A WHOLE SHOULD AVERAGE ABOVE NORMAL THROUGH THE
PERIOD. HOW FAR ABOVE NORMAL WILL DEPEND ON CLOUD COVER AND
PRECIPITATION COVERAGE.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
MID AND HIGH CLOUDS WILL CONTINUE TO WORK INTO THE AREA DURING THE
OVERNIGHT HOURS AND INTO THE DAY ON MONDAY. THESE CLOUDS SHOULD
HELP TO LIMIT SOME FOG FORMATION HOWEVER HAVE ADDED MVFR FOG TO
KILN. IN ADDITION HAVE ADDED IFR FOG TO KLUK DUE TO LIGHT SE FLOW.
VFR CONDITIONS WILL RETURN TO THE TAF SITES BY 13Z ON MONDAY. A
WEAK SYSTEM WILL MOVE CLOSE TO THE AREA ON MONDAY HOWEVER CURRENT
INDICATIONS ARE THAT PRECIPITATION WILL STAY SW OF THE AREA TAF
SITES. AN ISOLATED SHOWER IS NOT OUT OF THE QUESTION HOWEVER
AROUND THE KCVG AND KLUK AREA FOR MONDAY. WINDS WILL BE LESS THAN
10 KNOTS THROUGH THE TAF PERIOD.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE ON TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR/HATZOS
SHORT TERM...JDR
LONG TERM...HICKMAN
AVIATION...NOVAK
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1136 PM CDT SUN JUL 29 2012
.UPDATE...
UPDATED FOR AVIATION.
&&
.PREV DISCUSSION... /ISSUED 923 PM CDT SUN JUL 29 2012/
UPDATE...
THE FORECAST FOR TONIGHT STILL LOOKS LARGELY ON TRACK. A FEW
STORMS CONTINUE OVER SOUTHERN MISSOURI...BUT ARE IN A WEAKENING
PHASE. LITTLE RIPPLES CONTINUE TO SPILL DOWN THE FORWARD FLANK OF
AN EXPANSIVE RIDGE OVER THE SOUTHERN PLAINS WHICH MAY KICK OFF
ADDITIONAL STORMS OVERNIGHT...SIMILAR TO WHAT THE THE GLOBAL
MODELS AND THE HRRR ARE SHOWING OVERNIGHT. THUS...DESPITE LITTLE
ACTIVITY UPSTREAM AT THE PRESENT TIME...CANNOT RULE OUT ADDITIONAL
DEVELOPMENT BUT IT IS BEGINNING TO LOOK A LITTLE LESS LIKELY.
ANY ACTIVITY TONIGHT WILL HAVE SIGNIFICANT IMPLICATIONS ON
TEMPERATURES TOMORROW. 00Z NAM CONTINUES TO ADVERTISE 110+ DEGREE
HIGHS ACROSS THE DELTA MONDAY AS AN INCREDIBLE THERMAL RIDGE
ARRIVES WITH 925 MB TEMPS IN THE +32 TO +35C RANGE. THE NAM HAS
BEEN RATHER CONSISTENT IN SHOWING THIS FOR THE PAST FEW DAYS AND
IT SEEMED TO HAVE INITIALIZED WELL OVER THE PLAINS TONIGHT.
THUS...IT IS A LITTLE CONCERNING. HISTORY HAS SHOWN...HOWEVER...
THAT IT TENDS TO RUN ABOUT 5 DEGREES TOO WARM ON OTHER SUCH
EXTREME HEAT DAYS THIS MONTH. THE CANADIAN AND ECMWF ARE SHOWING
105 DEGREE HIGHS WEST OF THE RIVER AS WELL SO MODELS SEEM TO BE IN
A BIT OF AGREEMENT. TOUGH TO SAY WHAT DEW POINTS WILL DO...BUT AM
THINKING WITH A STRONG WESTERLY FLOW AND A DRY SLOT ASSOCIATED
WITH LOW PRESSURE OVER SOUTHEAST MISSOURI PUNCHING IN...WE SHOULD
BE ABLE TO MIX DOWN INTO THE 60S AT LEAST IN THE DELTA. THIS WILL
YIELD RH VALUES IN THE 20S WITH FIRE WEATHER BECOMING A CONCERN.
MIXING SHOULD ALSO KEEP HEAT INDEX VALUES BELOW 110...BUT IT WILL
BE CLOSE.
BORGHOFF
PREV DISCUSSION... /ISSUED 320 PM CDT SUN JUL 29 2012/
DISCUSSION...
SKIES ARE PARTLY CLOUDY ACROSS MUCH OF WEST TENNESSEE AND PARTS OF
NORTH MISSISSIPPI THIS AFTERNOON WITH MOSTLY SUNNY SKIES ACROSS
THE REMAINDER OF THE FORECAST AREA. TEMPERATURES RANGE FROM THE
MID 80S TO UPPER 90S. SOME SHOWERS AND THUNDERSTORMS CONTINUE TO
MOVE ACROSS SECTIONS OF WEST TENNESSEE THIS AFTERNOON. THIS
ACTIVITY IS ASSOCIATED WITH A UPPER LEVEL DISTURBANCE WHICH IS
MOVING ACROSS SOUTHEAST MISSOURI THIS AFTERNOON AND SHOULD MOVE
THROUGH MIDDLE TENNESSEE AND NORTH ALABAMA TONIGHT. SOME ADDITIONAL
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TONIGHT MAINLY OVER
NORTHERN AND EASTERN SECTIONS OF THE FORECAST AREA.
BY MONDAY...UPPER LEVEL RIDGE WILL CONTINUE TO BUILD INTO THE
REGION BRINGING ANOTHER ROUND OF VERY HOT AND HUMID WEATHER. HEAT
INDEX VALUES WILL LIKELY EXCEED 105 DEGREES OVER ROUGHLY THE
WESTERN HALF OF THE FORECAST AREA SO WILL ISSUE A HEAT ADVISORY
FOR MONDAY. TEMPERATURES WILL BE QUITE HOT WITH AFTERNOON READINGS
RANGING FROM THE MID 90S TO AROUND 102. ISOLATED THUNDERSTORMS WILL
BE POSSIBLE BOTH MONDAY AND MONDAY NIGHT AS WELL AS ANOTHER WEAK
UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION MONDAY NIGHT.
TUESDAY WILL BE ANOTHER VERY HOT DAY WITH AFTERNOON TEMPERATURES
IN THE MID 90S TO AROUND 100. A FEW ISOLATED THUNDERSTORMS WILL BE
POSSIBLE MAINLY OVER EASTERN SECTIONS TUESDAY AND TUESDAY NIGHT.
BY WEDNESDAY...THE UPPER LEVEL RIDGE WILL RETREAT SOME TO THE WEST
AND REMAIN OVER THE SOUTHWEST U.S. FOR MUCH OF THE REMAINDER OF
THE FORECAST PERIOD. AS A RESULT...TEMPERATURES FROM WEDNESDAY
THROUGH NEXT SUNDAY WILL NOT BE AS HOT AS THEY WILL BE FOR MONDAY
AND TUESDAY WITH AFTERNOON READINGS MAINLY IN THE MID 90S.
ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE PERIOD AS
WELL.
ARS
&&
.AVIATION...
06Z TAFS
MIDLEVEL CLOUDS NEAR FL100 CONTINUED TO STREAM SOUTH THROUGH THE
MID MS RIVER VALLEY AT 0430Z. THESE CLOUDS AND ASSOCIATED SHRA
WERE ENHANCED BY AN UPPER LEVEL DISTURBANCE EVIDENT ON GOES WATER
VAPOR IMAGERY. SUFFICIENT ELEVATED INSTABILITY EXISTED FOR
ISOLATED TSRA IN THE SHORT TERM FOR THE MKL VICINITY. OVERNIGHT
TSRA CHANCES FOR MEM ARE NONZERO... BUT APPEAR MORE LIMITED THAN
FURTHER EAST AT MKL AND PERHAPS TUP.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 78 103 80 101 / 10 20 20 20
MKL 72 98 75 99 / 30 20 20 20
JBR 75 105 78 102 / 10 20 20 10
TUP 73 97 77 98 / 20 20 20 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CALHOUN-COAHOMA-
DESOTO-LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-
TUNICA-YALOBUSHA.
TN...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CROCKETT-DYER-
FAYETTE-GIBSON-HAYWOOD-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON-
WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
923 PM CDT SUN JUL 29 2012
.UPDATE...
THE FORECAST FOR TONIGHT STILL LOOKS LARGELY ON TRACK. A FEW
STORMS CONTINUE OVER SOUTHERN MISSOURI...BUT ARE IN A WEAKENING
PHASE. LITTLE RIPPLES CONTINUE TO SPILL DOWN THE FORWARD FLANK OF
AN EXPANSIVE RIDGE OVER THE SOUTHERN PLAINS WHICH MAY KICK OFF
ADDITIONAL STORMS OVERNIGHT...SIMILAR TO WHAT THE THE GLOBAL
MODELS AND THE HRRR ARE SHOWING OVERNIGHT. THUS...DESPITE LITTLE
ACTIVITY UPSTREAM AT THE PRESENT TIME...CANNOT RULE OUT ADDITIONAL
DEVELOPMENT BUT IT IS BEGINNING TO LOOK A LITTLE LESS LIKELY.
ANY ACTIVITY TONIGHT WILL HAVE SIGNIFICANT IMPLICATIONS ON
TEMPERATURES TOMORROW. 00Z NAM CONTINUES TO ADVERTISE 110+ DEGREE
HIGHS ACROSS THE DELTA MONDAY AS AN INCREDIBLE THERMAL RIDGE
ARRIVES WITH 925 MB TEMPS IN THE +32 TO +35C RANGE. THE NAM HAS
BEEN RATHER CONSISTENT IN SHOWING THIS FOR THE PAST FEW DAYS AND
IT SEEMED TO HAVE INITIALIZED WELL OVER THE PLAINS TONIGHT.
THUS...IT IS A LITTLE CONCERNING. HISTORY HAS SHOWN...HOWEVER...
THAT IT TENDS TO RUN ABOUT 5 DEGREES TOO WARM ON OTHER SUCH
EXTREME HEAT DAYS THIS MONTH. THE CANADIAN AND ECMWF ARE SHOWING
105 DEGREE HIGHS WEST OF THE RIVER AS WELL SO MODELS SEEM TO BE IN
A BIT OF AGREEMENT. TOUGH TO SAY WHAT DEW POINTS WILL DO...BUT AM
THINKING WITH A STRONG WESTERLY FLOW AND A DRY SLOT ASSOCIATED
WITH LOW PRESSURE OVER SOUTHEAST MISSOURI PUNCHING IN...WE SHOULD
BE ABLE TO MIX DOWN INTO THE 60S AT LEAST IN THE DELTA. THIS WILL
YIELD RH VALUES IN THE 20S WITH FIRE WEATHER BECOMING A CONCERN.
MIXING SHOULD ALSO KEEP HEAT INDEX VALUES BELOW 110...BUT IT WILL
BE CLOSE.
BORGHOFF
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT SUN JUL 29 2012/
DISCUSSION...
SKIES ARE PARTLY CLOUDY ACROSS MUCH OF WEST TENNESSEE AND PARTS OF
NORTH MISSISSIPPI THIS AFTERNOON WITH MOSTLY SUNNY SKIES ACROSS
THE REMAINDER OF THE FORECAST AREA. TEMPERATURES RANGE FROM THE
MID 80S TO UPPER 90S. SOME SHOWERS AND THUNDERSTORMS CONTINUE TO
MOVE ACROSS SECTIONS OF WEST TENNESSEE THIS AFTERNOON. THIS
ACTIVITY IS ASSOCIATED WITH A UPPER LEVEL DISTURBANCE WHICH IS
MOVING ACROSS SOUTHEAST MISSOURI THIS AFTERNOON AND SHOULD MOVE
THROUGH MIDDLE TENNESSEE AND NORTH ALABAMA TONIGHT. SOME ADDITIONAL
SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE TONIGHT MAINLY OVER
NORTHERN AND EASTERN SECTIONS OF THE FORECAST AREA.
BY MONDAY...UPPER LEVEL RIDGE WILL CONTINUE TO BUILD INTO THE
REGION BRINGING ANOTHER ROUND OF VERY HOT AND HUMID WEATHER. HEAT
INDEX VALUES WILL LIKELY EXCEED 105 DEGREES OVER ROUGHLY THE
WESTERN HALF OF THE FORECAST AREA SO WILL ISSUE A HEAT ADVISORY
FOR MONDAY. TEMPERATURES WILL BE QUITE HOT WITH AFTERNOON READINGS
RANGING FROM THE MID 90S TO AROUND 102. ISOLATED THUNDERSTORMS WILL
BE POSSIBLE BOTH MONDAY AND MONDAY NIGHT AS WELL AS ANOTHER WEAK
UPPER LEVEL DISTURBANCE MOVES THROUGH THE REGION MONDAY NIGHT.
TUESDAY WILL BE ANOTHER VERY HOT DAY WITH AFTERNOON TEMPERATURES
IN THE MID 90S TO AROUND 100. A FEW ISOLATED THUNDERSTORMS WILL BE
POSSIBLE MAINLY OVER EASTERN SECTIONS TUESDAY AND TUESDAY NIGHT.
BY WEDNESDAY...THE UPPER LEVEL RIDGE WILL RETREAT SOME TO THE WEST
AND REMAIN OVER THE SOUTHWEST U.S. FOR MUCH OF THE REMAINDER OF
THE FORECAST PERIOD. AS A RESULT...TEMPERATURES FROM WEDNESDAY
THROUGH NEXT SUNDAY WILL NOT BE AS HOT AS THEY WILL BE FOR MONDAY
AND TUESDAY WITH AFTERNOON READINGS MAINLY IN THE MID 90S.
ISOLATED THUNDERSTORMS WILL ALSO BE POSSIBLE THROUGH THE PERIOD AS
WELL.
ARS
&&
.AVIATION...
00Z TAFS
SCATTERED SHRA WAS GRADUALLY DECREASING IN COVERAGE FROM SOUTHERN
MO... EASTWARD INTO KY. THIS ACTIVITY...BORNE FROM MIDLEVEL VFR CIGS...
WAS ASSOCIATED WITH A MIDLEVEL DISTURBANCE DROPPING SOUTH THROUGH
THE OZARK PLATEAU.
SIMILAR TO THIS MORNING... ISOLATED SHRA WILL BE POSSIBLE THIS
EVENING AND OVERNIGHT...AS ADDITIONAL UPPER LEVEL ENERGY DROPS
INTO THE MID MS RIVER VALLEY. OTHERWISE...VFR AND LIGHT WINDS
WILL PREVAIL ACROSS THE MIDSOUTH TONIGHT AND EARLY MONDAY.
PWB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 78 102 80 101 / 20 20 20 20
MKL 72 98 75 99 / 30 20 20 20
JBR 75 105 78 102 / 20 20 20 10
TUP 73 97 77 98 / 20 20 20 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-LEE AR-MISSISSIPPI-
PHILLIPS-POINSETT-RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CALHOUN-COAHOMA-
DESOTO-LAFAYETTE-MARSHALL-PANOLA-QUITMAN-TALLAHATCHIE-TATE-
TUNICA-YALOBUSHA.
TN...HEAT ADVISORY FROM 10 AM TO 8 PM CDT MONDAY FOR CROCKETT-DYER-
FAYETTE-GIBSON-HAYWOOD-LAKE-LAUDERDALE-OBION-SHELBY-TIPTON-
WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
909 PM CDT SUN JUL 29 2012
.UPDATE...
EARLIER LIGHT RAIN THAT PUSHED ACROSS THE CWA HAS DISSIPATED WITH
CLEARING SKIES AREAWIDE. HOWEVER...WATER VAPOR IMAGERY SHOWS A
VORT MAX MOVING SOUTHEAST ACROSS ILLINOIS. MOST MODEL GUIDANCE
INCLUDING THE 00Z NAM...18Z GFS...AND 23Z HRRR INDICATES THAT AS
THIS FEATURE APPROACHES THE MID STATE OVERNIGHT...ADDITIONAL
SHOWERS AND POSSIBLY A FEW THUNDERSTORMS WILL DEVELOP OVER
SOUTHERN IL/W KY/W TN. THIS ACTIVITY WILL THEN SPREAD
SOUTHEASTWARD INTO AREAS MAINLY WEST OF I-65 AND ESPECIALLY CLOSER
TO THE TN RIVER. WILL ADJUST PRECIP CHANCES TO SHOW CHANCE POPS
NEAR THE WESTERN CWA BORDER WITH SLIGHT CHANCE POPS FURTHER TO THE
EAST AND NO PRECIP ON THE PLATEAU. REST OF FORECAST FOR TONIGHT
APPEARS TO BE ON TRACK AND ONLY MINOR TWEAKS WERE MADE.
&&
.PREV DISCUSSION... /ISSUED 833 PM CDT SUN JUL 29 2012/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
EXPECT GENERALLY VFR CONDITIONS NEXT 24 HOURS ACROSS THE MID
STATE. SOME LATE NIGHT FOG CAN BE EXPECTED TONIGHT AT CROSSVILLE
WITH MVFR CONDITIONS DEVELOPING. HOWEVER...MUST KEEP AN EYE TO THE
NORTHWEST AS MID STATE REMAINS UNDER A NORTHWEST FLOW WITH
EMBEDDED SPEED MAX DIVING SOUTHEAST IN THE OVERNIGHT AND EARLY
MONDAY MORNING. ISOLATED CONVECTION HAS BEEN TRYING TO DEVELOP
IN FAR SOUTHERN ILLINOIS AND FAR WESTERN KENTUCKY THIS EVENING BUT
IS HAVING A HARD TIME OF IT. HOWEVER...90+ JET HAS BEEN DROPPING
SOUTHEAST FROM EASTERN IOWA WITH NOSE OF JET DOWN THROUGH THE
SAINT LOUIS AREA INTO FAR WESTERN KENTUCKY. THIS AREA IS RIGHT ON
THE EDGE OF THE LID OF VERY WARM AIR +12 CELSIUS ASSOCIATED WITH
UPPER LEVEL HIGH OUT OVER THE CENTRAL/SOUTHERN PLAINS. AS SPEED
MAX DROPS SOUTHEAST EXPECT TO SEE CONVECTION FIRE FROM NORTHWEST
ILLINOIS DOWN THROUGH THE SAINT LOUIS AREA AND MOVE INTO FAR
WESTERN KENTUCKY AND EVENTUALLY DOWN INTO WESTERN TENNESSEE AND
PERHAPS NORTHWEST MIDDLE TENNESSEE DURING THE LATE NIGHT/EARLY
MONDAY MORNING. 850-300 MILLIBAR THICKNESS PATTERN WOULD CARRY
MOST IF NOT ALL OF THIS CONVECTION DOWN INTO NORTH MISSISSIPPI AND
NORTHWEST ALABAMA CLIPPING WESTERN MIDDLE TENNESSEE LATE TONIGHT
AND EARLY MONDAY MORNING.
BOYD
PREV DISCUSSION... /ISSUED 529 PM CDT SUN JUL 29 2012/
UPDATE...
SENDING OUT A QUICK UPDATE TO EXTEND SLIGHT CHANCE POPS FURTHER
EASTWARD BASED ON LATEST RADAR TRENDS. AREA OF LIGHT RAIN MOVING
SOUTHEASTWARD CONTINUES TO WEAKEN AND SHRINK IN SIZE...BUT PRECIP
IS NEVERTHELESS MAKING IT FURTHER EASTWARD THAN CURRENT
GRIDS/ZONES INDICATE. REST OF FORECAST IS UNCHANGED.
PREV DISCUSSION... /ISSUED 305 PM CDT SUN JUL 29 2012/
DISCUSSION...TEMPS WERE A LITTLE LOWER THIS AFTN COMPARED TO
SATURDAY IN THE WAKE OF YESTERDAY/S WEAK FRONT PLUS THE CLOUD
COVER THAT HAS BEEN INCREASING FROM THE NORTHWEST TODAY. AN AREA
OF SHOWERS HAS BEEN APPROACHING MID TN FROM THE NORTHWEST ALL DAY
AND HAS REFUSED TO WEAKEN. SOME LIGHT RETURNS ON 88D WERE NOTED IN
NW COUNTIES AT 19Z. HRRR SEEMS TO BE HANDLING THIS PRECIP BETTER
THE PAST COUPLE HOURS...AND IT SHOWS THE AREA GRADUALLY WEAKENING
AS IT MOVES THROUGH WEST MIDDLE TN DURING NEXT SEVERAL HOURS BEFORE
DISSIPATING BEFORE 00Z.
FOR THE WEEK AHEAD...MODELS AGREE THAT NORTHWEST FLOW WILL
CONTINUE ALOFT THROUGH MOST OF THE WEEK AS H5 RIDGE...CENTERED
OVER WESTERN OKLAHOMA AT 12Z TODAY...STAYS IN THE VCNTY OF THE TX
PANHANDLE THROUGH AT LEAST THURSDAY. THIS PATTERN LEAVES TN
VULNERABLE TO WEAK SHORT WAVES APPROACHING FROM THE NW...
ESPECIALLY OVER THE NEXT COUPLE DAYS.
THE NEXT S/W TO APPROACH US WAS OVER SOUTHERN MN AT 12Z. MODELS
ARE INCONSISTENT IN HANDLING PRECIP FROM THIS S/W AS WELL AS THE
NEXT ONE. THE NAM HITS THE FIRST ONE HARDER LATE TONIGHT AND
MONDAY...WHILE THE GFS HITS THE SECOND ONE HARDER ON MONDAY NIGHT
AND TUESDAY. CANNOT HAVE CONFIDENCE IN MODEL TIMING EITHER OF
THESE WAVES BUT 20 TO 30 POPS ARE CERTAINLY WARRANTED AREA WIDE FOR
MOST OF THE WEEK. CONVECTION MAY BE MINIMIZED ON WEDNESDAY AS
MODELS SHOW LOWER MEAN HUMIDITY BEHIND THE SECOND S/W.
BY FRIDAY AND NEXT WEEKEND...THE H5 RIDGE ELONGATES ACROSS THE
WHOLE SOUTHERN U.S. AND ENDS OUR NW FLOW PATTERN. THUS...NORMAL
SUMMER DIURNAL CONVECTION EXPECTED WITH 20 TO 30 PERCENT CHANCE OF
AFTN/EVENING STORMS. TEMPS WILL CONTINUE ABOVE SEASONAL NORMS
WITH HIGHS IN 90S AND LOWS IN 70S EXCEPT A FEW DEGREES LOWER ON
THE PLATEAU.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHAMBURGER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
833 PM CDT SUN JUL 29 2012
.UPDATE...FOR 00Z AVIATION FORECAST
&&
.AVIATION...
EXPECT GENERALLY VFR CONDITIONS NEXT 24 HOURS ACROSS THE MID
STATE. SOME LATE NIGHT FOG CAN BE EXPECTED TONIGHT AT CROSSVILLE
WITH MVFR CONDITIONS DEVELOPING. HOWEVER...MUST KEEP AN EYE TO THE
NORTHWEST AS MID STATE REMAINS UNDER A NORTHWEST FLOW WITH
EMBEDDED SPEED MAX DIVING SOUTHEAST IN THE OVERNIGHT AND EARLY
MONDAY MORNING. ISOLATED CONVECTION HAS BEEN TRYING TO DEVELOP
IN FAR SOUTHERN ILLINOIS AND FAR WESTERN KENTUCKY THIS EVENING BUT
IS HAVING A HARD TIME OF IT. HOWEVER...90+ JET HAS BEEN DROPPING
SOUTHEAST FROM EASTERN IOWA WITH NOSE OF JET DOWN THROUGH THE
SAINT LOUIS AREA INTO FAR WESTERN KENTUCKY. THIS AREA IS RIGHT ON
THE EDGE OF THE LID OF VERY WARM AIR +12 CELSIUS ASSOCIATED WITH
UPPER LEVEL HIGH OUT OVER THE CENTRAL/SOUTHERN PLAINS. AS SPEED
MAX DROPS SOUTHEAST EXPECT TO SEE CONVECTION FIRE FROM NORTHWEST
ILLINOIS DOWN THROUGH THE SAINT LOUIS AREA AND MOVE INTO FAR
WESTERN KENTUCKY AND EVENTUALLY DOWN INTO WESTERN TENNESSEE AND
PERHAPS NORTHWEST MIDDLE TENNESSEE DURING THE LATE NIGHT/EARLY
MONDAY MORNING. 850-300 MILLIBAR THICKNESS PATTERN WOULD CARRY
MOST IF NOT ALL OF THIS CONVECTION DOWN INTO NORTH MISSISSIPPI AND
NORTHWEST ALABAMA CLIPPING WESTERN MIDDLE TENNESSEE LATE TONIGHT
AND EARLY MONDAY MORNING.
BOYD
&&
.PREV DISCUSSION... /ISSUED 529 PM CDT SUN JUL 29 2012/
UPDATE...
SENDING OUT A QUICK UPDATE TO EXTEND SLIGHT CHANCE POPS FURTHER
EASTWARD BASED ON LATEST RADAR TRENDS. AREA OF LIGHT RAIN MOVING
SOUTHEASTWARD CONTINUES TO WEAKEN AND SHRINK IN SIZE...BUT PRECIP
IS NEVERTHELESS MAKING IT FURTHER EASTWARD THAN CURRENT
GRIDS/ZONES INDICATE. REST OF FORECAST IS UNCHANGED.
PREV DISCUSSION... /ISSUED 305 PM CDT SUN JUL 29 2012/
DISCUSSION...TEMPS WERE A LITTLE LOWER THIS AFTN COMPARED TO
SATURDAY IN THE WAKE OF YESTERDAY/S WEAK FRONT PLUS THE CLOUD
COVER THAT HAS BEEN INCREASING FROM THE NORTHWEST TODAY. AN AREA
OF SHOWERS HAS BEEN APPROACHING MID TN FROM THE NORTHWEST ALL DAY
AND HAS REFUSED TO WEAKEN. SOME LIGHT RETURNS ON 88D WERE NOTED IN
NW COUNTIES AT 19Z. HRRR SEEMS TO BE HANDLING THIS PRECIP BETTER
THE PAST COUPLE HOURS...AND IT SHOWS THE AREA GRADUALLY WEAKENING
AS IT MOVES THROUGH WEST MIDDLE TN DURING NEXT SEVERAL HOURS BEFORE
DISSIPATING BEFORE 00Z.
FOR THE WEEK AHEAD...MODELS AGREE THAT NORTHWEST FLOW WILL
CONTINUE ALOFT THROUGH MOST OF THE WEEK AS H5 RIDGE...CENTERED
OVER WESTERN OKLAHOMA AT 12Z TODAY...STAYS IN THE VCNTY OF THE TX
PANHANDLE THROUGH AT LEAST THURSDAY. THIS PATTERN LEAVES TN
VULNERABLE TO WEAK SHORT WAVES APPROACHING FROM THE NW...
ESPECIALLY OVER THE NEXT COUPLE DAYS.
THE NEXT S/W TO APPROACH US WAS OVER SOUTHERN MN AT 12Z. MODELS
ARE INCONSISTENT IN HANDLING PRECIP FROM THIS S/W AS WELL AS THE
NEXT ONE. THE NAM HITS THE FIRST ONE HARDER LATE TONIGHT AND
MONDAY...WHILE THE GFS HITS THE SECOND ONE HARDER ON MONDAY NIGHT
AND TUESDAY. CANNOT HAVE CONFIDENCE IN MODEL TIMING EITHER OF
THESE WAVES BUT 20 TO 30 POPS ARE CERTAINLY WARRANTED AREA WIDE FOR
MOST OF THE WEEK. CONVECTION MAY BE MINIMIZED ON WEDNESDAY AS
MODELS SHOW LOWER MEAN HUMIDITY BEHIND THE SECOND S/W.
BY FRIDAY AND NEXT WEEKEND...THE H5 RIDGE ELONGATES ACROSS THE
WHOLE SOUTHERN U.S. AND ENDS OUR NW FLOW PATTERN. THUS...NORMAL
SUMMER DIURNAL CONVECTION EXPECTED WITH 20 TO 30 PERCENT CHANCE OF
AFTN/EVENING STORMS. TEMPS WILL CONTINUE ABOVE SEASONAL NORMS
WITH HIGHS IN 90S AND LOWS IN 70S EXCEPT A FEW DEGREES LOWER ON
THE PLATEAU.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
309 AM CDT MON JUL 30 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
309 AM CDT MON JUL 30 2012
MUCH OF THE SHORT TERM FOCUS IS ON TODAYS FORECAST FOR HIGH
TEMPERATURES AND THE CHANCES FOR THUNDERSTORMS THAT COULD PRODUCE
STRONG WINDS.
CURRENTLY...SKIES HAVE MAINLY CLEARED OUT BESIDES SOME HIGH LEVEL
CLOUDS MOVING ACROSS NORTHEAST IOWA AND SOUTHERN WISCONSIN. WITH
A SURFACE RIDGE AXIS OF HIGH PRESSURE IN PLACE FROM THE GREAT
LAKES WEST THROUGH THE REGION...SHALLOW GROUND/VALLEY FOG HAS
FORMED IN MANY LOW LYING AREAS. FURTHER TO THE NORTHWEST...A COLD
FRONT EXTENDS FROM NORTHWEST OF DULUTH TOWARD NORTHEAST SOUTH
DAKOTA. THIS FRONT WILL BE THE FOCUS FOR CONVECTION TODAY AS IT
DIVES SOUTHEAST THROUGH THE REGION.
SOUTHWESTERLY LOW LEVEL WINDS WILL BE ON THE INCREASE TODAY AHEAD
OF THE FRONT WHICH WILL ADVECT WARMER AIR INTO THE REGION. THE
30.00Z NAM IS THE WARMEST OF THE GUIDANCE WITH 850MB TEMPERATURES
OF AROUND +23C AND 925MB TEMPERATURES REACHING +33C BY MID
AFTERNOON. THE 30.00Z GFS/ECMWF/GEM ARE MORE CONSERVATIVE WITH
850MB TEMPS AROUND +20C AND 925MB TEMPS AROUND +27C TO +30C. THE
MAIN LIMITATION TO TEMPERATURES TODAY WILL AGAIN BE WITH CLOUD
COVER...PARTICULARLY THE HIGH LEVEL BAND OF CLOUDS THAT ARE ON THE
EASTERN NOSE OF A MOISTURE FEED THAT COMES OUT OF THE
GULF...ROUNDS THE WESTERN EDGE OF THE MID LEVEL RIDGE THROUGH
ARIZONA AND THEN ROUNDS THE NORTHERN PERIPHERY OF THE RIDGE ACROSS
THE CENTRAL PLAINS ON INTO IOWA. 30.06Z RAP AND 30.00Z NAM/GFS RH
FIELDS SHOW THIS HIGHER CONCENTRATION OF UPPER LEVEL MOISTURE
TRACKING TO THE SOUTHEAST TODAY...WHICH SHOULD LEAVE MAINLY SUNNY
SKIES TODAY AND ALLOW FOR MOST OF THE AREA TO GET INTO THE LOWER 90S.
THE TIMING OF THE COLD FRONT MOVING THROUGH THIS AFTERNOON WILL BE
IDEAL IN TERMS OF COMING THROUGH DURING PEAK DIURNAL HEATING WHEN
INSTABILITY SHOULD BE MAXIMIZED AT ABOUT 2000 J/KG OF SURFACE
BASED CAPE. THE 30.00Z NAM/GFS/ECMWF/GEM ALL ARE IN REASONABLE
AGREEMENT WITH THIS FROPA TIMING ALONG WITH MUCH OF THE REST OF
THE SETUP FOR TODAY. THE BEST LIFT APPEARS TO SHOW UP ACROSS
NORTHERN WISCONSIN THIS AFTERNOON AND IS MAINLY IN THE LOW LEVELS
WITH SOME WEAK 0-2KM CONVERGENCE AND FRONTOGENESIS SHOWING UP FROM
NORTHEAST WISCONSIN TOWARD LA CROSSE BY AROUND 21Z. THE MAIN
LIMITATIONS WILL BE WITH A 850-700MB CAP THAT WILL SUPPRESS MOST
OF THE CONVECTION UNTIL THE AFTERNOON AND WITH A POOR LOW LEVEL
MOISTURE FEED OUT OF THE NORTHERN PLAINS WHICH WILL KEEP THE
COVERAGE OF THE STORMS DOWN. 30.00Z NAM/GFS BUFKIT SOUNDINGS DO
SHOW A FAVORABLE PROFILE FOR STRONG WINDS ONCE THE CAP BREAKS WITH
AN INVERTED V SOUNDING IN THE AFTERNOON. INCREASING 0-3KM SHEAR TO
AROUND 30-40KTS SHOWS UP ACROSS THE CENTRAL PORTION OF WISCONSIN
ALONG THE FRONT...SO THE THREAT APPEARS TO BE THERE THIS AFTERNOON
FOR SEVERE STORMS THAT PRODUCE DAMAGING WINDS ACROSS MAINLY THE
CENTRAL AND EASTERN PORTIONS OF WISCONSIN. CAN NOT RULE OUT SOME
HAIL GIVEN THE AMOUNT OF INSTABILITY...BUT THE MAIN THREAT SHOULD
BE WITH THE WIND. BY 00Z TONIGHT...THE FRONT SHOULD EXTEND FROM
JUST NORTH OF GREEN BAY TO JUST SOUTH OF LA CROSSE AND INTO
NORTHERN ILLINOIS BY MIDNIGHT. PRECIPITATION CHANCE-WISE...THE
MAIN QUESTION IS WITH COVERAGE AND HOW FAR TO THE WEST WILL THE
CONVECTION DEVELOPING INTO THE STRONGER CAP. ANY STORM DEVELOPMENT
WILL BE MORE ISOLATED THE FURTHER WEST YOU GO WITH MORE WIDESPREAD
STORMS LIKELY TOWARD EASTERN WISCONSIN.
AFTER THE FRONT MOVES THROUGH...A RIDGE OF HIGH PRESSURE SETTLES
IN ACROSS THE REGION FOR TUESDAY BEFORE SHIFTING SOUTH A BIT ON
WEDNESDAY. THE NEXT COLD FRONT WILL BE DROPPING DOWN ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY REGION WEDNESDAY NIGHT AND WILL
BRING THE NEXT CHANCES FOR PRECIPITATION ALONG WITH IT.
TEMPERATURES WILL SLOWLY CLIMB AS THE WINDS SHIFT AROUND TO THE
SOUTH ON WEDNESDAY.
.LONG TERM...THURSDAY THROUGH SUNDAY
309 AM CDT MON JUL 30 2012
AN ACTIVE PATTERN WILL CONTINUE INTO THIS WEEKEND WITH THE MAIN
FEATURE BEING A POTENT LOW PRESSURE SYSTEM THAT WILL MOVE THROUGH
ON SATURDAY. BEFORE THAT THOUGH...A MID LEVEL SHORT WAVE TROUGH
WILL DROP DOWN THROUGH THE NORTHWEST FLOW ON THURSDAY WHILE A COLD
FRONT MOVES THROUGH AT THE SURFACE. HIGH PRESSURE WILL BRIEFLY
BUILD IN AT THE SURFACE FOR FRIDAY BEFORE THE MAIN SHOW RAMPS UP
FRIDAY NIGHT INTO SATURDAY. A CLOSED MID LEVEL LOW WILL TRACK
ACROSS SOUTHERN CANADA OVER THIS TIME FRAME WITH A DEEPENING
SURFACE LOW FORMING ACROSS THE DAKOTAS ON FRIDAY. FAIRLY GOOD
AGREEMENT AMONGST THE LONG TERM 30.00Z GUIDANCE WITH THE
POSITION/TIMING OF THE MID LEVEL CUT OFF LOW AND THE SURFACE
LOW/FRONT SETUP. THE WAY THINGS CURRENTLY LOOK...THERE WOULD BE A
COMPLEX OF STORMS THAT WOULD FORM IN THE EASTERN DAKOTAS FRIDAY
WHICH WOULD THEN TRAVEL EAST THROUGH THE REGION INTO SATURDAY
MORNING. THE SURFACE LOW WOULD THEN BE IN AN OCCLUDING STAGE ON
SATURDAY WITH THE WARM SECTOR MAINLY ACROSS EASTERN WISCONSIN AND
THE COLD FRONT NEAR THE MISSISSIPPI RIVER BY 18Z. LOTS OF DETAILS
TO STILL BE HASHED OUT...BUT THIS SYSTEM WILL BRING THE BEST
CHANCES FOR HEAVY RAINFALL OVER THE NEXT WEEK.
&&
.AVIATION...THROUGH 06Z TUESDAY
1202 AM CDT MON JUL 30 2012
WILL CONTINUE TO FORECAST IFR FOG IN THE UPCOMING 06Z TAFS.
TEMPERATURE AND DEW POINT SPREADS ARE 2-4F AT 04Z UNDER CLEAR SKIES
AND CALM WINDS AT BOTH TAF SITES. THIS IS A NICE SETUP FOR IFR FOG
FORMATION. CONFIDENCE TO GO TO AN LIFR FOG EVENT WAS NOT HIGH
ENOUGH BECAUSE THERE ARE SOME UPSTREAM CLOUDS IN THE 10 KFT AND
ABOVE RANGE THAT MAY PLAY A ROLE IN REDUCING THE COOLING SOMEWHAT
IF THEY REMAIN THICK ENOUGH. KTOB TO THE WEST OF KRST FELL TO
1/2SM FAG FROM 10SM IN THE LAST HOUR.
HAVE STILL NOT INCLUDED A TSRA/VATS INTO THE TAF SITES FROM A COLD
FRONTAL PASSAGE BETWEEN 19-22Z. THERE REMAINS INSTABILITY OF
1500-2000 J/KG ON THE FRONT AND CONVERGENCE...BUT LITTLE UPPER
LEVEL SUPPORT FOR WIDESPREAD INITIATION OF TSRA ALONG THE FRONT.
THUS...HAVE KEPT SCT100 DURING FRONTAL PASSAGE FOR NOW. FUTURE
FORECASTS WILL HAVE TO ASSESS THE TSRA POTENTIAL AND CONFIDENCE
FOR POSSIBLE INCLUSION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 AM CDT MON JUL 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1112 AM EDT MON JUL 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A WARM SUMMER AFTERNOON. INCREASING
HUMIDITY AND SLOW MOVING LOW PRESSURE ALOFT WILL FUEL SCATTERED
SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
JUDGING FROM BLEND OF RECENT SATELLITE AND UPPER AIR DATA ALONG
WITH HRRR AND WRF-NMM MODEL OUTPUT, EXPECT MOST OF THE UPPER OHIO
VALLEY TO HAVE A WARM AND DRY AFTERNOON.
CANNOT COMPLETELY RULE OUT ISOLATED THUNDERSTORM DEVELOPMENT LATE
THIS AFTERNOON, BUT CONFINED MENTION OF SLIGHT CHANCE TO NEED NEAR
THE WV-MD MOUNTAINS AND PA LAUREL HIGHLANDS.
NEED CONVECTIVE TEMPERATURES OF 83-85F BEFORE CUMULUS BUILD
UPS/TOWERING CUMULUS/ DEVELOP, WHICH COULD HAPPEN 3-4 PM. HOWEVER,
DEEP MOISTURE WILL BE LACKING, SO DRY ENTRAINMENT MAY PREVENT
CUMULONIMBUS, EXCEPT WHERE LIFT AND MOISTURE CONVERGENCE ARE
OROGRAPHICALLY ENHANCED.
AS HUMIDITY INCREASES OVERNIGHT, ITS POSSIBLE THUNDERSTORMS MAY
DEVELOP ACROSS OTHER PARTS OF THE UPPER OHIO VALLEY.
FORECASTED TEMPERATURES A COUPLE DEGREES WARMER THAN NORMAL USING
BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
MODELS IN OVERALL AGREEMENT ON THE EASTBOUND PASSAGE OF A SERIES
OF UPPER LEVEL SHORTWAVE TROUGHS THROUGH THE HUMID UPPER OHIO
VALLEY THIS PERIOD. SO HAVE CONTINUED SHOWER AND THUNDERSTORM
CHANCES INTO WEDNESDAY, WITH A CONTINUED DIURNAL TREND FOR HIGHER
AFTERNOON AND EVENING POPS.
BULK OF ACTIVITY SHOULD BE ON THE WANE WEDNESDAY AFTERNOON AS
MODELS IN GENERAL SHIFT DEEPER MOISTURE EAST OF THE RIDGES.
THE SPC SEVERE WEATHER OUTLOOK SHOWS NO MORE THAN A 5 PERCENT
CHANCE OF SEVERE THUNDERSTORMS THIS PERIOD, AS VERTICAL WIND SHEAR
WILL BE WEAK.
AS THE OVERALL FLOW PATTERN FOR THE SHORT TERM IS CLOSE TO THE
SUMMER CLIMATOLOGY...TEMPERATURES SHOULD AVERAGE OUT CLOSE TO THE
SEASONAL NORMALS AND WERE FORECAST USING A BLEND OF GUIDANCE.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
BLEND OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW HIGH PRESSURE
PROVIDING MAINLY DRY CONDITIONS ACROSS THE UPPER OHIO VALLEY
THURSDAY AND FRIDAY. THEREAFTER...HAVE FORECASTED A CHANCE OF
THUNDERSTORMS FOR THE WEEKEND...AS SOUTHERLY WIND ON THE WESTERN FLANK
OF THE EXITING HIGH PRESSURE INCREASE HUMIDITY AND INSTABILITY IN
ADVANCE OF EASTBOUND CANADIAN LOW PRESSURE.
FORECASTED TEMPERATURES WILL AVERAGE ABOVE NORMAL BASED ON A
BLEND OF GFS AND ECMWF MOS WITH NAEFS MEDIAN VALUES.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL DOMINATE THE WEATHER ACROSS THE TERMINALS
THROUGH THE TAF PERIOD. CLOUDS WILL BE ON THE INCREASE INTO THE
EVENING. AT THIS TIME DID NOT INSERT ANY PRECIPITATION BECAUSE OF
LOW PROBABILITY AT TERMINALS. NAM DOES TRY TO BRING IN SCATTERED
SHOWERS MONDAY EVENING BUT GFS HOLDS OFF WITH MORE LIKELY
PROBABILITY ON TUESDAY. WENT WITH GFS SOLUTION AND HELD OFF ANY
PRECIP. WINDS SHOULD NOT BE A PROBLEM COMING FROM THE SE AND S BY
LATE IN THE DAY AND WILL ALL BE BELOW 10KTS.
OUTLOOK...TUESDAY NIGHT THROUGH FRIDAY...
A WEAK FRONTAL SYSTEM WILL BE PUSHING EAST FROM THE MIDWEST AND
WILL TRIGGER SOME SCATTERED SHOWERS AND THUNDERSTORMS ESPECIALLY
BY TUESDAY AFTERNOON. SOME SCATTERED SHOWERS AND STORMS COULD
LINGER INTO WEDNESDAY AND THEN HIGH PRESSURE WILL MOVE EAST FOR
THURSDAY AND MOST OF FRIDAY WITH VFR CONDITIONS.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
727 AM EDT MON JUL 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT MON JUL 30 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS BTWN GENERAL TROFFING CENTERED NEAR HUDSON BAY AND
PERSISTENT RDG AXIS OVER THE HI PLAINS. WITH LOSS OF DAYTIME
HEATING...SHRA/TS THAT IMPACTED THE CWA LAST EVNG HAVE DIMINISHED.
BUT ANOTHER LINE OF SHRA/TS IS PUSHING SEWD THRU THE MN ARROWHEAD IN
ADVANCE OF POTENT SHRTWV MOVING ESEWD IN MANITOBA TOWARD NW MN AND
LEFT EXIT OF SUPPORTING 75KT H3 JET MAX NOTED IN THE NRN PLAINS.
THIS LINE OF TS PROMPTED THE ISSUANCE OF A WATCH FOR MUCH OF NE
MN...WITH SOME SVR TS GIVEN STEEP MID LVL LAPSE RATES SHOWN ON THE
00Z INL RAOB THAT CONTRIBUTED TO MUCAPE IN EXCESS OF 2000 J/KG AS
WELL AS EFFECTIVE DEEP LYR SHEAR UP TO 40KTS UNDER UNIDIRECTIONAL
WNW FLOW ALF PER SPC ANALYSIS. PRESENCE OF DRIER AIR ALF SHOWN ON
00Z RAOBS HAS CONTRIBUTED TO DCAPE AOA 1000 J/KG IN PORTIONS OF THE
AREA IMPACTED BY THE WATCH. RECENT TRENDS HOWEVER ARE FOR THE STORMS
TO WEAKEN AS THEY MOVE INTO A BIT MORE STABLE AIR IMPACTED BY
NOCTURNAL COOLING AND AXIS OF LOWER H85 DEWPTS OVER CENTRAL MN.
MAIN FCST CONCERNS THIS PACKAGE INCLUDE CONVECTIVE TRENDS INTO TNGT
AND POTENTIAL FOR SVR STORMS.
TODAY...VIGOROUS SHRTWV TO THE NW IS PROGGED TO MOVE TO JUST N OF
INL AT 12Z MON AND THEN INTO FAR NE LK SUP BY 00Z TUE WITH SWATH OF
VIGOROUS DVPA/DEEP LYR QVECTOR CNVGC MOVING W-E ACRS UPR MI.
ALTHOUGH AXIS OF LOWER H85 THETA E CONTRIBUTING TO WEAKENING STORMS
IN MN NOW MAY TEND TO REDUCE COVERAGE/INTENSITY THIS MRNG...ONSET OF
DAYTIME HEATING AND ARRIVAL OF MORE IMPRESSIVE H85 THETA E ADVECTION
BY THIS AFTN IN PRESENCE OF THE HEFTY DYNAMICS SHOULD LEAD TO NMRS
SHRA/TS...ESPECIALLY OVER THE CNTRL AND E WHERE ARRIVAL OF DYNAMICS
APPEAR TO BE MOST IN SYNC WITH DAYTIME HEATING. NAM/GFS FCST SNDGS
INDICATE SBCAPE WL REACH AOA 2000 J/KG AS HI TEMPS RISE WELL INTO
THE 80S AWAY FM LK MODERATION MOST PRONOUNCED OFF LK MI. DRYING ALF
UNDER UNIDIRECTIONAL WNW FLOW ON THE SRN FLANK OF SHRTWV TRACK IS
FCST TO CONTRIBUTE TO SFC-10K FT AGL DELTA THETA E UP TO 25C...VERY
FAVORABLE PER THE MQT SEVERE WX CHECKLIST TO ENHANCE DCAPE. THE
BIGGEST DRAWBACK FOR ORGANIZED SEVERE WX IS FCST RATHER MODEST DEEP
LYR SHEAR ONLY 25-30KTS. THIS WEAKER SHEAR MAY RESULT IN MORE PULSE
SVR EPISODES...WITH THE BETTER CHC FOR ORGANIZED STORMS WHERE LK
BREEZE CNVGC OVER MAINLY THE E HALF MIGHT ENHANCE THE SHEAR AS WELL
AS INCRS LLVL CNVGC AND SHRA/TS COVERAGE. SHRA/TS WL DIMINISH OVER
THE W IN THE AFTN WITH ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/LLVL
DRYING IN THE WAKE OF SHRTWV PASSAGE/ATTENDANT COLD FROPA.
TNGT...DRYING/NEGATIVE H85 THETA E ADVECTION IN THE WAKE OF SHRTWV
MOVING INTO SE ONTARIO AND LOSS OF DAYTIME HEATING WL CAUSE SHRA/TS
TO DIMINISH NW-SE. HOWEVER...MODELS SHOW QUITE A BIT OF LINGERING
LLVL MSTR WITH NNW FLOW IN THE WAKE OF DEPARTING SHRTWV/SFC LO. LO
CLDS MAY BE ESPECIALLY TENACIOUS IN THE UPSLOPE AREAS NEAR LK SUP...
WHERE THERE MAY EVEN BE SOME -DZ/SPRINKLES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 443 AM EDT MON JUL 30 2012
VERY ACTIVE FORECAST PERIOD...AS UPPER MI SITS IN AN UPPER LEVEL
TROUGHING PATTERN THROUGH TUESDAY...BEFORE STRONG RIDGING PATTERN
OVER MUCH OF THE CONUS BEGINS TO MOVE EASTWARD INTO THE REGION.
ALONG THIS RIDGE...SEVERAL SHORTWAVES WILL PASS OVER UPPER MI
BRINGING CHANCES FOR TSRA WED AND THUR AND THEN AGAIN DURING THE
WEEKEND.
AFTER EXITING 500MB SHORTWAVE DURING THE DAY TUESDAY...STRONG
RIDGING WILL BEGIN TO PUSH IN FROM WEST TO EAST...WHICH WILL ALSO
TRANSLATE TO SURFACE HIGH PRESSURE. AS WINDS TURN TO A NORTHERLY
DIRECTION...EXPECT AN INFLUX OF DRY AIR AND CLEARING SKIES ACROSS
THE REGION. SUCH A WIND DIRECTION WILL CAUSE HIGH TEMPERATURES TO BE
SLIGHTLY COOLER THAN THE PREVIOUS DAY...BUT STILL A QUITE
COMFORTABLE MID 70 TO LOW 80 DEGREE RANGE. WINDS WILL THEN TURN TO A
MORE SOUTHERLY DIRECTION ON THE BACKSIDE OF THE SURFACE
HIGH...ALLOWING WARMER WINDS OFF THE LAKE DURING THE FIRST PART OF
THE NIGHT...AND THEN SOUTHERLY WINDS ACROSS THE INTERIOR FOR THE
LAST HALF. THIS SHOULD MODERATE TEMPERATURES TO STAY AT OR ABOVE
NORMAL. UNFORTUNATELY...SURFACE HIGH PRESSURE WILL BE SHORT-LIVED AS
THE FIRST OF SEVERAL SHORTWAVES BEGINS TO TRAVERSE THE AREA BY LATE
WEDNESDAY WITH UPPER LEVEL RIDGING IN PLACE.
MAIN SHORTWAVE AND SURFACE LOW PRESSURE WILL SPREAD ACROSS LAKE
SUPERIOR LATE WEDNESDAY AND THROUGH THE DAY THURSDAY. HOWEVER THERE
IS SOME DISCREPANCY BETWEEN THE MODELS...AS THE NAM IS SLIGHTLY
DELAYED IN THE ARRIVAL OF THE SYSTEM...AND IS MUCH MORE AMPLIFIED
THAN THE OTHER MODELS. REGARDLESS...OVERALL EFFECTS OF THE SYSTEM
WILL BE SIMILAR...STARTING WITH THE INFLUX OF MOIST SOUTHERLY WINDS
/LLVL JET/ AHEAD OF THE SYSTEM AND DECENT WAA. THIS WILL ALLOW HIGH
TEMPERATURES WEDNESDAY TO RISE TO WELL ABOVE NORMAL INLAND /MID TO
UPPER 80S POSSIBLE/. WITH PRESENCE OF AFTERNOON LAKE BREEZES...AND
WARM/MOIST/UNSTABLE AIR IN PLACE...SHOULD SEE SOME AFTERNOON
CONVECTION INLAND AS A RESULT.
AS SYSTEM NEARS...EXPECT A WELL DEFINED AREA OF CONVERGENCE TO SPAWN
PRECIP ACROSS THE ENTIRE CWA WEDNESDAY NIGHT THROUGH
THURSDAY...DESPITE OUR LOCATION IN THE RIGHT EXIT REGION OF A VERY
WEAK JET. MU CAPE VALUES ARE POINTING AT CENTRAL AND WESTERN UPPER
MI GETTING UP TO BETWEEN 1.4-1.8K J/KG IN WEDNESDAY EVENING...AND
THEN MAXING OUT AROUND 2K J/KG OVERNIGHT...THOUGH CAPE WILL BE
FAIRLY SKINNY AND MAINLY CONFINED TO THE MID AND UPPER LEVELS WITH
THE BEST MOISTURE...WHILE THE LOWER LEVELS SHOULD REMAIN FAIRLY DRY.
THAT BEING SAID...MODEL SOUNDINGS SHOW SOME IMPRESSIVE SHEAR
THROUGHOUT THE ENTIRE COLUMN /BOTH DIRECTIONAL AND SPEED/ SO COULD
SEE SOME WIDESPREAD ELEVATED TSRA DEVELOPMENT...BUT WITH LITTLE
MOISTURE IN THE LOW LEVELS...SHOULD/T BE MUCH OF A RAIN SOAKER.
SHORTWAVE AND BEST FORCING SHOULD MOVE OFF TO THE EAST DURING THE
DAY THURSDAY AHEAD OF SURFACE COLD FRONT...BUT THE BREAK IN PRECIP
WILL BE SHORT-LIVED AS LARGER 500MB SHORTWAVE OVER SASKATCHEWAN
FRIDAY AFTERNOON BEGINS TO MOVE ALONG THE SAME TRACK SOUTHEAST
TOWARDS THE UPPER GREAT LAKES. WHILE ALL MODELS ARE IN GOOD
AGREEMENT OF THIS LOW STRENGTHENING AND BECOMING CLOSED OFF AS IT
REACHES THE UPPER GREAT LAKES...THERE IS LITTLE AGREEMENT IN THE
EXACT TIMING AND TRACK...SO WILL GO WITH A GENERAL MODEL CONSENSUS
AT THIS TIME. WITH SOME LOW LEVEL MOISTURE FROM PREVIOUS SYSTEM
ALREADY IN PLACE...COULD SEE SOME SCATTERED SHRA/TSRA DEVELOPMENT AS
EARLY AS FRIDAY MORNING FAR WEST WITH THIS SYSTEM. A STRONG UPPER
LEVEL JET WILL CRUISE OVER UPPER MI BY SATURDAY PUTTING US IN THE
LEFT ENTRANCE REGION...FURTHERING ENHANCING PRECIP CHANCES. PWAT
VALUES WILL QUICKLY RISE TO 160 PERCENT OF NORMAL THROUGH SATURDAY
MORNING AS SURFACE WARM FRONT AND WELL DEFINED AREA OF QVECTOR CONV
TRAVERSES FROM WEST TO EAST. UNLIKE WEDNESDAY NIGHT/THURSDAY...THIS
SYSTEM WILL HAVE ABUNDANT MOISTURE THROUGH ALL LAYERS...SO EXPECT
THIS TO BE A GOOD RAIN EVENT. BY SATURDAY AFTERNOON COLD FRONT WILL
PRESENT IMPRESSIVE FORCING...LATEST GFS HAS 0-3KM COMPUTED CAPE
VALUES MAXING OUT AROUND 1.2K SOUTH CENTRAL...WITH MU CAPE VALUES
2.2-2.6K J/KG OVER MUCH OF THE WESTERN AND CENTRAL CWA. FORECAST
SOUNDINGS SHOW MUCH IMPROVEMENT OVER THE SKINNY ELEVATED CAPE DURING
PREVIOUS EVENT...AND ONCE AGAIN SHEAR LOOKS TO BE VERY IMPRESSIVE
BOTH FOR DIRECTION AND SPEED. DCAPE ON THE OTHER HAND WILL BE ON THE
DIMINISHING TREND DURING THE DAY SATURDAY...SO ONCE STORMS DEVELOP
EXPECT THE MAIN THREAT TO BE HEAVY RAINS...ABUNDANT LIGHTNING...AND
POTENTIAL HAIL.
THE SYSTEM WILL CONTINUE ON ITS TRACK TO THE SOUTHEAST DURING THE
NIGHT SATURDAY...WITH A WELCOME BREAK IN PRECIP BY SUNDAY AFTERNOON
AS HIGH PRESSURE ONCE AGAIN REGAINS CONTROL
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 726 AM EDT MON JUL 30 2012
CLUSTER OF SHRA/TS IN ADVANCE OF STRONG DISTURBANCE MOVING ESEWD
THRU ONTARIO JUST N OF THE BORDER IS IN THE PROCESS OF DIMINISHING.
SOME SHRA MAY REACH SAW...BUT SUSPECT THESE WILL WEAKEN...SO
INCLUDED ONLY MENTION OF VCSH. ALTHOUGH THERE MAY BE SOME MVFR CIGS
AT CMX FOR A FEW HRS THIS MRNG AFT THE HEAVIER SHRA THERE...EXPECT
MAINLY VFR CONDITIONS THIS MRNG. CLOSER APRCH OF THIS DISTURBANCE
AND ATTENDANT COLD FNT WITH MOIST UNSTABLE AIRMASS AT TIME OF PEAK
DAYTIME HEATING WL TRIGGER MORE SHRA/TS THIS AFTN. SUSPECT THIS
ACTIVITY WILL IMPACT MAINLY SAW AS DRIER AIR WL BE MAKING ITS WAY
INTO WRN UPR MI BY THE TIME PEAK HEATING COMMENCES. SO INCLUDED
SPECIFIC MENTION OF TS ONLY AT SAW. FOLLOWING THE COLD FROPA...
FAIRLY HUMID LLVL AIR WL LINGER. SO WITH UPSLOPE NNW WIND DVLPG
BEHIND THE FROPA...EXPECT LO CLDS/FOG/IFR CONDITIONS AT ALL 3 SITES
PER VARIOUS MOS FCST PRODUCTS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT MON JUL 30 2012
EXPECT SSW WINDS UP TO 20 KTS AND SOME TS IN ADVANCE OF LO PRES TROF
THAT IS FORECAST TO DRIFT ACROSS LAKE SUPERIOR LATE TODAY AND
TONIGHT. BEHIND THE TROF PASSAGE...WINDS WILL SHIFT TO THE NNW AS
HIGH PRESSURE SETS IN...HOWEVER THE W LAKE COULD CONTINUE TO SEE
GUSTS BETWEEN 15 AND 20 KNOTS THROUGH THE MORNING HOURS WITH THIS
WIND DIRECTION. ANOTHER TROF WILL BRING TSRA CHANCES WEDNESDAY
AFTERNOON THROUGH TUESDAY EVENING...AND AGAIN BY FRIDAY. OTHERWISE
EXPECT WINDS TO REMAIN BELOW 15 KNOTS ACROSS THE LAKE FOR THE FCST
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JMW
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
605 AM CDT MON JUL 30 2012
.UPDATED FOR 12Z AVIATION DISCUSSION BELOW...
.DISCUSSION...
OVERVIEW...NEAR TO ABOVE NORMAL TEMPS EXPECTED TO CONTINUE WITH
NOTABLE COOLING IN THE EXTENDED DUE TO ARRIVAL OF ANOTHER UPPER
LOW. STILL SOME TIMING ISSUES TO WORK OUT YET...BUT DECENT CHANCES
FOR RAIN ON WEDNESDAY AND SATURDAY. SEVERAL SUBTLE SHORTWAVES COME
RIPPLING THROUGH THE AREA OVER THE NEXT FEW DAYS...BUT MOST OF
THESE FEATURES WILL MOVE HARMLESSLY THROUGH THE FORECAST AREA WITH
LITTLE CHANGE TO OUR SENSIBLE WEATHER.
TWO AREAS OF PRECIPITATION THIS MORNING...ONE IN THE NORTHERN
PLAINS AND THE OTHER IN NORTHERN MN BOTH BEING ASSISTED BY STRONG
250MB JET STRETCHED OUT ACROSS SD...MN...IA/WI AND IL. THE
FORECAST AREA IS ACTUALLY IN AN ZONE WHERE THE QG VERTICAL VELOCITY
SUGGESTS SINKING AIR. THERE ARE ALSO A COUPLE COMPACT SHORTWAVES
HELPING TO DRIVE THE CONVECTION. THE AREA OF THUNDERSTORMS TO OUR
SOUTH IS EMBEDDED IN THAT MOIST TONGUE OF MONSOONAL AIR STREAMING
OUT OF THE FOUR CORNERS. MEANWHILE...THE NORTHERN SHORT WAVE IS
EMBEDDED IN CYCLONIC CURVATURE. WHILE IT HAS LOST SOME OF ITS
DEFINITION...THIS FEATURE WILL STILL PLAY A ROLE IN KEEPING THE
THREAT FOR RAIN ACROSS WESTERN WI THIS MORNING. BY THIS
AFTERNOON...THE NORTHERN STREAM SFC TROUGH AND CORRESPONDING COLD
FRONT WILL THROUGH THE AREA. WHILE CONVERGENCE FROM THE SURFACE TO
OVERLY STRONG...THERE WILL DEFINITELY BE SOME WEAK FGEN AND QG
VERTICALLY VELOCITY THIS AFTERNOON IN WESTERN WI. MUCAPE HAS
FALLEN OFF THIS MORNING...BUT SHOULD BE ENOUGH TIME OUT AHEAD OF
THE SURFACE WAVE TO BUILD SOME INSTABILITY. INCLUDED SMALL POPS IN
WEST CENTRAL WI...BUT ACTIVITY MAY IN FACT BE EVEN FURTHER EAST
GIVEN THE CURRENT SPEED OF THINGS. THIS THINKING FALLS IN LINE
WITH THE SPC DAY ONE SLIGHT RISK AREA.
EXPECT IT TO BE A BIT COOLER AND DRIER IN THE WAKE OF THE SURFACE
TROUGH WHEN THE HIGH BUILDS IN ON TUESDAY. POPS/WEATHER GET A BIT
MORE COMPLICATED WEDNESDAY INTO FRIDAY WITH MUCH LESS
AMPLIFICATION TO THE LONG WAVE PATTERN AND A SLOWLY EVOLVING
SURFACE TROUGH JUST WEST OF THE FORECAST AREA. THERE WILL
CERTAINLY BE THUNDERSTORMS AROUND...LIKELY AIDED BY THE NOCTURNAL
LOW LEVEL JET AND IN THE DAKOTAS AND WESTERN MN.
IN THE EXTENDED...THE EC HAS BEEN TRENDING WARMER EARLY/MIDDLE OF
NEXT WEEK OVER THE LAST COUPLE AND THE GFS HAS BEEN TRENDING
COOLER. THE 500MB HEIGHTS AND 850MB TEMPS OFF THE EC SUGGEST ONCE
A AGAIN TEMPS WELL INTO THE 90S. THE RECENT GFS SOLUTIONS HAVE
BEEN MUCH FLATTER WITH THE HEIGHTS AND COOLER AT 850 MB. THE
ENSEMBLE MEANS OF THE EC/GFS SUGGEST THE OPERATIONAL RUNS ARE NOT
COMPLETELY OFF BASE. JUST HAVE TO WAIT AND SEE IF THE SOLUTIONS
BEGIN TO CONVERGE OVER THE NEXT COUPLE DAYS.
&&
.AVIATION.../12Z TAF ISSUANCE/
SOME FOG ISSUES AROUND SOUTHERN AREAS AHEAD OF INCOMING FRONT. MAY
HAVE TO INCLUDE SOME AT KEAU/KRNH EARLY. RARITY OF LATE WITH FRONT
MOVING THROUGH THE CWA ON THE DRY SIDE THROUGH THE MORNING. WILL
MOVE THROUGH THE KEAU AREA AROUND 19Z. THIS WOULD BE THE ONLY AREA
THAT WOULD HAVE A SMALL CHANCE OF SEEING AND CONVECTION AS WELL.
WILL LEAVE IT OUT FOR NOW. WINDS BECOMING NORTHWEST BEHIND FRONT AND
COULD MIX OUT A 20 KNOT GUST OR SO. THE RAP HAS BEEN STRONGER WITH
THE WIND LAST SEVERAL RUNS. SOME CUMULUS EXPECTED AS WELL...WITH
SOME SMALL NEGATIVE CU RULES OVER THE EASTERN AREAS. SHOULD LIFT
AND DISSIPATE BY EVENING. SKC OVERNIGHT EXPECTED WITH WINDS BECOMING
MORE NORTH/NORTHEAST AND LIGHT AS RIDGE BUILDS IN. LEFT OUT FOG
MENTION FOR NOW DUE TO DRIER DEWPOINTS EXPECTED.
KMSP...DRY FRONT MOVING THROUGH AROUND 18Z WITH WINDS TURNING MORE
NORTHWEST WITH SOME GUSTS TO 20 KNOTS POSSIBLE IN THE AFTERNOON.
FEW CUMULUS ALONG WITH SOME HIGH OR MID LEVEL CLOUDS AS FRONT EXITS
TO THE SOUTHEAST THIS AFTERNOON. WINDS DIMINISHING THIS EVENING
BECOMING LIGHT EAST TUESDAY MORNING. SKC EXPECTED OVERNIGHT INTO
TUESDAY.
//OUTLOOK
TUESDAY THROUGH TUESDAY NIGHT...VFR.
WEDNESDAY...MVFR CONDITIONS POSSIBLE WITH SHRA/TSRA.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/DE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
623 AM CDT MON JUL 30 2012
.AVIATION...12Z TAFS FOR KOFK...KOMA AND KLNK
VFR CONDITIONS ARE EXPECTED THRU THE TAF PERIOD. SFC WINDS WILL BE
AROUND OR LESS THAN 5 KTS...GENERALLY FROM THE EAST. A WEAK FRONT
WILL DROP INTO NORTHEAST NEBRASKA LATE THIS AFTERNOON. A FEW
SHOWERS OR THUNDERSTORMS COULD DEVELOP ALONG THIS BOUNDARY. THIS
WOULD MAINLY AFFECT KOFK...BUT DUE TO UNCERTAINTY...WILL LEAVE OUT
OF THE TERMINAL FOR NOW.
KERN
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT MON JUL 30 2012/
DISCUSSION...
TEMPERATURES AND PCPN CHANCES THE NEXT SEVERAL DAYS WILL PROVIDE THE
MAIN FORECAST CHALLENGES.
HIGHS YESTERDAY ENDED UP A LITTLE HOTTER THAN EXPECTED...ESPECIALLY
CENTRAL AND SOUTHERN ZONES. 00Z KOAX SOUNDING SHOWED MIXING UP TO
AROUND 825 MB AND EVEN A SMALL SUPERADIABATIC LAYER NEAR THE SURFACE.
OVERALL PATTERN IS SIMILAR TO YESTERDAY...BUT SUBTLE DIFFERENCES. AT
300 MB...JETSTREAM STILL STRETCHED FROM NEVADA INTO THE DAKOTAS...
THEN DIVED SOUTHEAST INTO THE OHIO VALLEY. A JET MAX OF AROUND 85 KTS
WAS NOTED OVER NORTHWEST NORTH DAKOTA AT 00Z. THIS APPEARED TO HAVE
SHIFTED INTO EASTERN SOUTH DAKOTA BY 06Z ACCORDING TO LATEST NAM12
AND RAP MODELS. CENTER OF RIDGE AT 700 MB AND 500 MB WAS LOCATED
OVER THE SOUTHERN PART OF THE TEXAS PANHANDLE. MONSOONAL MOISTURE
WAS WORKING ITS WAY NORTH INTO THE ROCKIES...THEN EASTWARD THROUGH
THE CENTRAL PLAINS. A MESOSCALE CONVECTIVE SYSTEM THAT DEVELOPED
OVER NORTHEAST COLORADO LAST EVENING CONTINUED TO MOVE EAST
ACROSS NORTHERN KANSAS AND SOUTHERN NEBRASKA EARLY THIS MORNING.
WILL MAINTAIN AREAL COVERAGE WORDING FOR OUR SOUTHERN ZONES INTO
MID MORNING...WHEN MCS MAY START TO WEAKEN. OTHERWISE...WILL HAVE
A SLIGHT CHANCE OF THUNDERSTORMS MOST AREAS UNTIL 18Z THEN
MAINTAIN LOW POPS MUCH OF THE FORECAST AREA THIS AFTERNOON. FELT
CLOUDS MAY HOLD HIGHS BACK SOME TODAY...SO WENT WITH MID TO UPPER
90S NORTH AND LOWER TO MID 90S SOUTH. SOME STORMS COULD POP UP
LATE THIS AFTERNOON OR EARLY EVENING NEAR A FRONTAL BOUNDARY THAT
PUSHES DOWN FROM THE NORTHERN PLAINS.
CENTER OF THE 500 MB RIDGE LOCATION DOES NOT CHANGE MUCH THROUGH
MID WEEK...AND SO MID LEVEL MOISTURE WILL BE ONE THING TO KEY ON
FOR CONVECTIVE POTENTIAL. HAVE A MAINLY DRY FORECAST GOING FROM
LATE THIS EVENING INTO TUESDAY EVENING. 00Z ECMWF SHOWS ANOTHER
PRETTY GOOD INCREASE IN 700 MB DEWPOINTS INTO THE AREA FOR LATE
TUESDAY NIGHT AND WEDNESDAY...SO SPREAD THUNDERSTORM CHANCES FROM
WEST TO EAST DURING THAT TIME.
LATER IN THE WEEK...A FAIRLY STRONG SHORTWAVE TROUGH DIGS OVER THE
NORTHERN ROCKIES THURSDAY...THEN MOVES INTO THE NORTHERN PLAINS BY
FRIDAY NIGHT. THIS SHOULD PUSH A FRONT THROUGH THE REGION FRIDAY
NIGHT OR SATURDAY. TEMPERATURES AHEAD OF THE FRONT SHOULD TOP OUT
MAINLY IN THE 90S TO AROUND 100 THROUGH THE WEEK. HIGHS BY SATURDAY
AND SUNDAY COULD COOL TO THE UPPER 80S/LOWER 90S. ALTHOUGH THE
FRONTAL PASSAGE SUGGESTS A DECENT CHANCE OF PCPN...MODELS DO NOT
AGREE ON QPF...SO WILL NOT GET TOO OPTIMISTIC AT THIS POINT.
MILLER
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
719 AM EDT MON JUL 30 2012
.SYNOPSIS...
A STATIONARY FRONT OVER EASTERN NORTH CAROLINA WILL WEAKEN TODAY. A
SERIES OF UPPER LEVEL DISTURBANCES WILL MOVE SOUTHEAST THROUGH THE
REGION THROUGH WEDNESDAY. UPPER LEVEL HIGH PRESSURE BUILDS OVER THE
REGION FROM THE WEST LATER IN THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 310 AM MONDAY...
TODAY...
WATER VAPOR IMAGERY THIS MORNING CONTINUES TO SHOW CONVECTIVELY
ENHANCED UPPER LEVEL DISTURBANCES MOVING SOUTHEAST OUT OF THE
UPPER MIDWEST...BETWEEN AN UPPER RIDGE OVER THE INNER MOUNTAIN
WEST AND A BROAD TROUGH OVER THE EASTERN US. THE MOST NOTABLE
DISTURBANCE APPROACHING THE CAROLINAS IN THE SHORT TERM IS
CURRENTLY NEAR THE IN/KY BORDER. THIS DISTURBANCE IS FORECAST TO
DEEPEN THE UPPER TROUGH AS IT SWINGS ACROSS NORTHERN GA AND SC
LATER TODAY. MODELS INDICATE THE LOW LEVEL WINDS WILL BACK IN
RESPONSE TO THE DEEPENING TROUGH...LEADING TO WEAK WARM
ADVECTION/VEERING PROFILE AND CONVECTIVE INITIATION ALONG A
STALLED OUT THE COLD FRONT OVER THE COASTAL PLAIN. WITH DEWPOINTS
HAVING RECOVERED INTO THE LOWER 70S AND PW UP TO 2 INCHES EAST OF
THE BOUNDARY BUT WEAK MID LEVEL LAPSE RATES...A MODEL CONSENSUS
GIVES 1000 TO MAYBE 1500 J/KG OF MLCAPE OVER THE COASTAL PLAIN AND
LESS TO THE WEST. THE WEAK CINH ON THE 00Z KMHX RAOB SHOULD ERODE
QUICKLY WITH HEATING LATER THIS MORNING AND HRRR SHOWS ISOLATED
CONVECTION AS EARLY AS 15-16Z AROUND SAMPSON/WAYNE COUNTY. WE WILL
SHOW POPS INCREASING WESTWARD DURING THE AFTERNOON AS THE
SOUTHEASTERLY FLOW AND ANY OUTFLOW OF SHOWERS/STORMS WILL HELP
SHIFT THE REMNANTS OF THE FRONT AND LOW LEVEL FOCUS WESTWARD.
HOWEVER...BASED ON THE 00Z KGSO RAOB AND FORECAST
SOUNDINGS...SHOWERS AND STORMS WILL ENCOUNTER A MORE PRONOUNCED
MID LEVEL CAP OVER THE WESTERN PIEDMONT..SO WE WILL KEEP POPS AT
SLIGHT CHANCE OVER MUCH OF THE WESTERN CWA. DEEP LAYER FLOW WILL
BE WEAK TODAY..SO ANY HAZARDOUS WEATHER WILL BE FROM PULSING
STRONGER STORMS AND AN ISOLATED PRECIP LOADED DOWNBURST.
GUIDANCE CONTINUES TO BE VERY CONSISTENT WITH HIGHS RIGHT AT
NORMAL VALUES...88-90
TONIGHT...
MODELS SHOW A WEAK SURFACE WAVE DEVELOPING OVER THE COASTAL PLAIN
BENEATH WEAK HEIGHT FALLS ALOFT. A RELATIVELY STRONG 35KT 850MB JET
IS FORECAST TO DEVELOP OFFSHORE...WHICH IS WHERE MOST OF THE
OVERNIGHT SHOWERS AND STORMS WILL BE FOCUSED. THUS...THERE SHOULD BE
LITTLE IMPACTS ON SENSIBLE WEATHER FOR CENTRAL NC..OTHER THAN A
LIGHT NORTHEASTERLY WIND AND POSSIBLY SOME PATCHY STRATUS BY TUESDAY
MORNING. LOWS IN THE LOWER 70S.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 310 AM MONDAY...
THE TRAIN OF UPPER LEVEL DISTURBANCES FROM THE UPPER MIDWEST TO THE
SOUTHERN APPALACHIANS WILL CONTINUE ON TUESDAY...AS MODELS SHOW A
80KT SPEED MAX AND ASSOCIATED VORTICITY DIVING TOWARD WESTERN NC AND
UP STATE SC BY EARLY AFTERNOON. MODELS INDICATE SOME CONVECTION OVER THE
MOUNTAINS AND ALONG THE COAST BY LATE MORNING...BUT A SHARPENING OF
THE MID/UPPER LEVEL TROUGH AXIS ASSOCIATED WITH THE AFOREMENTIONED UPPER
DISTURBANCE SHOULD LEAD TO SCATTERED SHOWERS AND STORMS OVER THE
WEST BY EARLY AFTERNOON. THE SEVERE THREAT OVER CENTRAL NC IS
SOMEWHAT UNCERTAIN AS THE STRONGER EFFECTIVE DEEP LAYER SHEAR WILL
LIKELY LIE TO THE SOUTHWEST OF THE CWA IN CLOSER PROXIMITY TO THE
BELT OF STRONGER MID LEVEL FLOW AND A FAIRLY STRONG SURFACE REFLECTION.
HOWEVER...IF STORMS CAN GET GOING OVER THE WESTERN AND SOUTHERN
PIEDMONT...THEN THERE WOULD BE A LOWER END THREAT OF DAMAGING WIND
GUSTS WITH STRONGER STORMS AND/OR MERGING COLD POOLS. WE WILL SHOW
HIGHEST POPS SHIFTING FROM THE SOUTHWEST TO EASTERN AREAS DURING THE
AFTERNOON AND EVENING...TRENDING DOWN TO A SLIGHT CHANCE OVERNIGHT.
WITH WEAK FLOW OVER CENTRAL NC DURING THE DAY AND NEAR MAXIMUM
INSOLATION...HIGHS SHOULD TOP OUT IN THE 86-90 RANGE BASED ON A
FORECAST 12Z LOW LEVEL THICKNESS OF 1405M. LOWS TUESDAY NIGHT ONCE
AGAIN IN THE UPPER 60S TO LOWER 70S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 AM MONDAY...
WEDNESDAY AND WEDNESDAY NIGHT...A MID-LEVEL TROUGH REMAINS OVER
CENTRAL NORTH CAROLINA...AND BOTH THE GFS AND THE NAM FORECAST AN
850MB TROUGH MOVING GRADUALLY WEST TO EAST ACROSS CENTRAL NORTH
CAROLINA THROUGH THE EVENING. THE NAM IS FARTHER SOUTH IN THE TRACK
OF THE 850MB WAVE AS COMPARED TO THE GFS...THOUGH BOTH FORECAST A
WEAK SURFACE WAVE MOVING OVER OR NEAR THE SANDHILLS AND THE SOUTHERN
COASTAL PLAIN AND TOWARD THE COAST WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT. WITH 850MB THETA-E RIDGING FORECAST BY THE GFS
DURING THE DAY...AND THE APPROACH OF A WEAK 50KT JETLET AT 250MB
FROM THE NORTHWEST AIDING IN UPPER DIFFLUENCE...EXPECT AT LEAST
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING OVER MUCH OF CENTRAL
NORTH CAROLINA DURING THE DAY. THE GREATER CHANCES WILL BE TOWARD
INTERSTATE 95...IN VICINITY OF DEEPER MOISTURE WHERE PRECIPITABLE
WATER VALUES WILL BE AROUND 1.75 INCHES...AS COMPARED TO 1.5 INCHES
TOWARD THE YADKIN RIVER. IT SHOULD BE NOTED THAT THE GFS BUFR
SOUNDINGS ARE STABLE IN COMPARISON TO THE NAM BUFR SOUNDINGS...
DESPITE THE FACT THE GFS HAS THE 850MB TROUGH FARTHER NORTH AND ITS
QPF IS GREATER THAN THE NAM. 0-6KM SHEAR IS AROUND 25KT...NOT TOO
BAD COMPARED TO MANY RECENT DAYS...AND MLCAPE IS FORECAST AROUND
2000J/KG DURING WEDNESDAY AFTERNOON. ALTHOUGH A SURFACE WAVE IS
FORECAST TO MOVE OVER OR VERY CLOSE TO THE AREA...ESPECIALLY TO THE
SOUTHEAST...0-3KM HELICITY VALUES ARE FAIRLY SMALL OVER CENTRAL
NORTH CAROLINA...ONLY RISING TO NEAR 100M2/S2 TOWARD AND OFFSHORE OF
THE CAROLINA COAST. IF ANY ISOLATED SEVERE STORMS WOULD DEVELOP...
CURRENT THOUGHTS ARE THE BETTER CHANCE WOULD BE FROM ABOUT U.S. 1
EASTWARD.
BEHIND THE SURFACE AND 850MB WAVES...THE OVERALL AIR MASS DRIES ON
BUFR SOUNDINGS OVERNIGHT WEDNESDAY. HOWEVER...BUFR SOUNDINGS FROM
BOTH THE NAM AND THE GFS SHOW SLIGHT LAYER COOLING ABOVE 700MB...
AND THE GFS FORECASTS FAIRLY ROBUST POTENTIAL VORTICITY ON THE 1.5
PVU SURFACE MOVING INTO CENTRAL NORTH CAROLINA LATE AT NIGHT IN THE
NORTHWEST FLOW ALOFT. POSSIBLY FOR THESE REASONS BOTH THE NAM AND
GFS FORECAST LIGHT QPF OVER THE PIEDMONT OVERNIGHT...AND WILL
MAINTAIN A SLIGHT CHANCE OF A SHOWER OR THUNDERSTORM DUE TO THE
SLIGHT POTENTIAL FOR WHAT SHOULD BE ELEVATED...DEEP CONVECTION.
FOLLOWED A BLEND OF THE MET AND MAV MOS AND THE BIAS CORRECTED MOS
GUIDANCE FOR WEDNESDAY WITH HIGHS AROUND 90...AND EXPECT OVERNIGHT
LOWS WEDNESDAY AROUND 70.
FROM THURSDAY THROUGH THE END OF THE WEEK...LONG-TERM GUIDANCE
CONSENSUS IS FOR HEIGHTS TO INCREASE OVER AND AROUND CENTRAL NORTH
CAROLINA...AS RIDGING BUILDS EAST FROM THE PLAINS AND...PROBABLY
MORE SO...INFLUENCED BY RIDGING OVER THE NORTH ATLANTIC. DESPITE THE
RIDGING ALOFT...RELATIVE TROUGHINESS SHOULD REMAIN IN THE FLOW ALOFT
OVER THE MID-ATLANTIC. THE RESULT SHOULD BE LIGHT...BUT BROADLY
DIFFLUENT FLOW ALOFT. 1000-850MB THICKNESSES SHOULD WARM...LEADING
TO HIGHS MOST DAYS IN THE LOWER TO MID 90S...AND A FEW UPPER 90S
CANNOT BE COMPLETELY RULED OUT ESPECIALLY OVER THE SOUTHWEST
PIEDMONT...SANDHILLS...AND U.S. 1 CORRIDOR. CURRENTLY FORECAST DEW
POINTS LEAD TO HEAT INDICES AT THE END OF THE WEEK BETWEEN 100 AND
105 DEGREES...HIGHEST SATURDAY AND SUNDAY.
ALL OF THE LONG-TERM GUIDANCE SUGGESTS PERIODIC PASSAGE OF WEAK
MID-LEVEL DISTURBANCES IN THE BROADLY DIFFLUENT WEST-NORTHWEST FLOW
ALOFT. THE TIMING OF THESE...AND HOW THEY ARE INFLUENCED BY DEEP
CONVECTION UPSTREAM...IS DIFFICULT TO FORECAST IN THE LONG TERM. THE
COMBINATION OF SEA BREEZE AND PIEDMONT TROUGH INFLUENCES FOR
LOW-LEVEL LIFT...AND MID-LEVEL SHORTWAVES IN A MODESTLY MOIST AND
UNSTABLE AIR MASS...SHOULD RESULT IN ISOLATED TO SCATTERED CHANCES
FOR SHOWERS AND THUNDERSTORMS...GENERALLY DIURNALLY...EACH DAY. THE
LATEST GFS FORECASTS PRECIPITABLE WATER VALUES AT OR BELOW 1.5
INCHES ON THURSDAY...WHICH IS AT OR BELOW NORMAL FOR THIS TIME OF
YEAR AND COULD RESULT IN A LARGELY DRY DAY. PRECIPITABLE WATER
VALUES GRADUALLY CLIMB FRIDAY THROUGH THE WEEKEND ON THE GFS. NOT
BEING A FAN OF REMOVING SMALL CHANCES OF PRECIPITATION ESPECIALLY IN
THE HUMIDITY OF SUMMER...WILL CONTINUE THE OVERALL TREND AT THE END
OF THE WEEK OF ISOLATED CHANCES FOR A SHOWER OR THUNDERSTORM IN MOST
AREAS EXCEPT CHANCES TOWARD THE COASTAL PLAIN CLOSER TO ANY SEA
BREEZE AND WHERE MOISTURE WILL BE SOMEWHAT GREATER. DURING THE
WEEKEND...AND ESPECIALLY BY SUNDAY...AS MOISTURE GRADUALLY INCREASES
AND DUE TO GROWING SYNOPTIC SCALE UNCERTAINTY...WILL FORECAST BROAD
CHANCES FOR SHOWERS AND THUNDERSTORMS ACROSS CENTRAL NORTH CAROLINA.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
AS OF 720 AM MONDAY...
FOG IS CONFINED TO THE NORTHERN COASTAL PLAIN THIS MORNING...AND
KRWI IS THE ONLY TAF SITE IMPACTED. THE FOG WILL LIFT BY
14Z...WITH VFR CONDITIONS TO PREVAIL TODAY. SCATTERED SHOWERS AND
STORMS ARE EXPECTED TO DEVELOP LATE THIS MORNING INTO THE
AFTERNOON HOURS...FIRST OVER THE COASTAL PLAIN...THEN SPREADING
WESTWARD TOWARD THE WESTERN PIEDMONT. THE SCATTERED NATURE OF THE
SHOWERS/STORMS PRECLUDE ANY MENTION OF ADVERSE CONDITIONS IN THE
TAF AT THIS TIME.
TONIGHT...
GUIDANCE SUGGESTS VSBYS WILL DROP OVER THE COASTAL PLAIN AGAIN
LATE TONIGHT...AND SOME PATCHY STRATUS IS POSSIBLE AS A LIGHT
NORTHEASTERLY WIND DEVELOPS BEHIND A WEAK SURFACE LOW FORECAST TO
MOVE UP THE COAST OVERNIGHT.
OUTLOOK...
SCATTERED THUNDERSTORMS ARE EXPECTED TUESDAY AND WEDNESDAY
AFTERNOON AS UPPER LEVEL DISTURBANCES CONTINUE TO MOVE ACROSS THE
REGION FROM THE NORTHWEST. BEYOND WEDNESDAY...TYPICAL SUMMERTIME
ISOLATED TO WIDELY SCATTERED STORMS ARE POSSIBLE EACH
AFTERNOON/EVENING...WITH EARLY MORNING FOG AND STRATUS ALSO
POSSIBLE.
&&
.CLIMATE...
THROUGH JULY 29...THE AVERAGE MONTHLY TEMPERATURE AT KRDU IS 83.8
DEGREES. THE WARMEST JULY ON RECORD IS 83.7 DEGREES...SET JUST
LAST YEAR. CONSIDERING EXPECTED HIGHS AND LOWS OVER THE NEXT
COUPLE OF DAYS...THIS JULY SHOULD EITHER BE THE WARMEST OR JUST
SHY OF THE WARMEST JULY ON RECORD.
AT KGSO...THE AVERAGE MONTHLY TEMPERATURE THROUGH JULY 29 IS 81.5
DEGREES. THIS IS CURRENTLY THIRD WARMEST...A HALF DEGREE WARMER THAN
THE 81.0 AVERAGE TEMPERATURE OF 2011...BUT WELL BELOW THE 82.6
RECORD OF 1893. CONSIDERING EXPECTED HIGHS AND LOWS OVER THE NEXT
COUPLE OF DAYS...IT APPEARS LIKELY THAT THE AVERAGE JULY TEMPERATURE
WILL RANK IN THE TOP THREE.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...SMITH
SHORT TERM...SMITH
LONG TERM...DJF
AVIATION...SMITH
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
958 AM EDT MON JUL 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TO OFF THE MID ATLANTIC COAST THIS
AFTERNOON. RETURN SOUTHEAST FLOW AROUND THE HIGH WILL BRING
INCREASING MOISTURE INTO TONIGHT. AN UPPER LEVEL TROUGH OF LOW
PRESSURE WILL THEN RESIDE OVER THE EASTERN UNITED STATES...YIELDING
THE POTENTIAL FOR UNSETTLED WEATHER INTO LATE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 AM EDT MONDAY...
ISOLATED SHOWERS CONTINUE TO LINGER ALONG THE EASTERN SLOPES AIDED
BY WEAK SE FLOW INTO THE BLUE RIDGE AND LOW LEVEL THETA-E GRADIENT
PARKED ALONG RIDGES. HOWEVER MORNING RAOBS SHOW THAT THE MOISTURE
REMAINS QUITE SHALLOW IN THE ZONE OF EASTERLY FLOW...CAPPED BY VERY
DRY AIR ALOFT WITH ONLY VERY WEAK MID LEVEL STEERING. THIS
SUPPORTS ADDED SLOW MOVING HEAVY RAIN PRODUCING SHRA/TSRA BUT
EXPECT COVERAGE TO BE LIMITED SOMEWHAT BY LACK OF MUCH SUPPORT
GIVEN PASSAGE OF ONE S/W ATTM AND ONLY FAINT ENERGY SPILLING IN
FROM THE WEST THIS AFTERNOON. LATEST FORECAST SOUNDINGS DO SHOW
THE CAP SLOWLY ERODING OVER THE WEST LATER ON WITH MOST LOCAL
MODELS AS WELL AS THE HRRR PRODUCING A SCATTERING OF CONVECTION
MAINLY MOUNTAINS. THUS BUMPED UP POPS SOME ACROSS THE WEST ESPCLY
BLUE RIDGE TO INIT AND INCLUDED A BRIEF HEAVY RAIN MENTION FOR
SLOW MOVING STORMS. ANY SVR SHOULD BE ISOLATED AND MAINLY WHERE
HELPED BY PRECIP LOADING PER HIGH WINDEX/DCAPE VALUES OFF MODIFIED
RAOBS. OTRW MAINLY PC WITH PLENTY OF CU AROUND AS MOISTURE SLOWLY
RETURNS. MORNING THICKNESS SUPPORTING HIGHS MOSTLY IN THE 80S BUT
MAYBE NOT QUITE AS WARM IN SPOTS SO TWEAKED DOWN RANGES A BIT.
PREVIOUS DISCUSSION AS OF 725 AM EDT MONDAY...
SHORTWAVE MOVING ACROSS ERN TN ATTM...WITH EASTERLY FLOW INTO THE
MTNS STILL KEEPING SHOWERS/FEW TSRA GOING FROM SOUTH OF ROANOKE TO
JUST SOUTH OF THE VA BORDER ALONG ROCKINGHAM/STOKES COUNTY LINE.
WILL SEE THE ACTIVITY CONTINUE UNTIL SHORTWAVE INFLUENCE
PASSES...ALTHOUGH WINDOW WILL BE SHORT AS ANOTHER SHORTWAVE HEADS
INTO THE COALFIELDS OF ERN KY BY 18Z TODAY. ADJUSTED POPS TO
ACCOUNT FOR THIS AND UPPED TEMPS THIS MORNING AS MORE CLOUD COVER
HAS KEPT TEMPS IN THE MID 60S TO AROUND 70.
PREVIOUS VALID DISCUSSION...
SHORTWAVE SINKS SOUTHEAST INTO GA/SC BY MIDDAY AND SHOULD TAKE
MOST OF THE HIGH CLOUDS WITH IT. ANOTHER WAVE PUSHES EAST OUT OF
THE OHIO VALLEY INTO THE BLUE RIDGE THIS AFTERNOON AND WITH UPPER
TROUGH OVERHEAD WITH UPPER DIVERGENCE AHEAD OF 80 KNOT
JET...SHOULD SEE ENOUGH LIFT TO INDUCE SCATTERED STORMS AFTER
MIDDAY. THE 00Z GFS/12Z ECMWF SEEM TO BE IN THE SAME CAMP IN
REGARDS TO THE UPPER LEVEL FEATURES AND TRY TO AIM THE BEST
COVERAGE OF SHOWERS AND STORMS FROM THE ALLEGHANY HIGHLANDS/WV
MTNS SOUTHEAST ALONG THE BLUE RIDGE. KEPT HIGHER POPS HERE WITH A
LESSER THREAT OVER THE PIEDMONT OF NC. WITH FLOW IN THE LOWEST
5KFT EAST TO SOUTHEAST AND WEST TO NW FLOW ALOFT SOME OF THESE
STORMS THAT FORM COULD BE ANCHORED TO THE RIDGES...RESULTING IN
POTENTIALLY HEAVIER RAIN AND POSSIBLE ISOLATED FLOODING...ALTHOUGH
PWATS ARE NOT AS HIGH AS A FEW DAYS AGO RANGING FROM 1 TO 1.4
INCHES.
TONIGHT...ONE SHORTWAVE EXITS WITH THE NEXT UPSTREAM WAVE MOVING
TOWARD THE TN VALLEY INTO THE SRN APPALACHIANS. GFS/ECMWF/SREF
LINGER THE CHANCES OF SHRA/TSRA ACROSS THE AREA THROUGH THE NIGHT
MAINLY ALONG EITHER SIDE OF THE BLUE RIDGE WHERE BEST CONVERGENCE
LIES. LOWERED POPS TO 30 AROUND THE BLUE RIDGE WITH SLIGHT CHANCE
EITHER SIDE.
FOR TEMPS...TODAY WILL SEE INCREASING HUMIDITY IN THE EAST PER SE
FLOW AND WITH CLOUDS FORMING FASTER...THINK MET MOS MAY HAVE BETTER
RESULTS WHICH IS A DEGREE OR THREE COOLER THAN MAV MOS. HIGHS WILL
RANGE FROM NEAR 90 EAST AND IN THE ROA/SRN SHENANDOAH VALLEYS TO
LOWER TO MID 80S WEST.
TONIGHT...THE FLOW IS WEAK AT THE SFC SO THINK LOWS SHOULD BE
SIMILAR TO THIS MORNING WITH 60S CWA WIDE...LOWER IN THE WEST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 340 AM EDT SUNDAY...
WILL START OUT THE DAY TUESDAY WITH THE PERSISTENT UPPER LEVEL
TROUGH DRIFTING SLOWLY TO THE EAST...BUT STILL SITUATED ALMOST
DIRECTLY OVER OUR AREA. THE SUBTLE UPPER DISTURBANCES RIDING INTO
THE BASE OF THE TROUGH FROM THE MIDWEST WILL TRIGGER ANOTHER ROUND
OF SCATTERED THUNDERSTORM ACTIVITY...INITIALLY DEVELOPING OVER THE
MOUNTAINS WITH SUPPORT FROM CONVERGENCE ALONG THE RIDGELINES...BUT
THEN SPREADING INTO THE PIEDMONTS AS AFTERNOON HEATING MAXIMIZES. AS
HAS BEEN TYPICAL OVER THE PAST SEVERAL WEEKS...A FEW OF THESE STORMS
WILL BECOME SEVERE...LIKELY WITHIN MINUTES OF DEVELOPING...WITH
DAMAGING WINDS AS THE GREATEST THREAT. PERIODS OF HEAVY RAIN...WITH
2 TO 3 INCH AMOUNTS LOCALLY...WILL ALSO POSSIBLE IN THE SLOWER
MOVING STORMS.
COME WEDNESDAY...THE WEATHER PATTERN REMAINS SIMILAR...WITH THE
UPPER TROUGH SHIFTING MORE TOWARDS THE COASTAL PLAIN...BUT ALSO
BECOMING MORE BROADENED BY EVENING. WE WILL ALSO SEE A COLD FRONT
MAKE ITS WAY SOUTHWARD FROM THE GREAT LAKES REGION INTO THE OHIO
RIVER VALLEY. IMPACTS FOR OUR AREA REMAIN RELATIVELY UNCHANGED...
WITH SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. WITH THE TROUGH
BECOMING LESS PRONOUNCED ACROSS OUR AREA...AFTERNOON TEMPERATURES
WILL ALSO BE TWO OR THREE DEGREES WARMER THAN THOSE FORECAST FOR
TUESDAY.
ON THURSDAY...THE UPPER TROUGH REALLY BREAKS DOWN...AND RIDGING FROM
THE SOUTHWEST BEGINS TO BUILD INTO OUR AREA. THIS RIDGING WILL WARM
THE MID AND UPPER LEVELS OF THE ATMOSPHERE...HELPING TO LIMIT THE
DEVELOPMENT OF THUNDERSTORMS DURING THE AFTERNOON AND EVENING...
ALTHOUGH WE WILL STILL SEE A FEW. FORECAST MODELS ARE ALSO IN
AGREEMENT THAT THE COLD FRONT WILL STALL SOMEWHERE BETWEEN THE OHIO
RIVER VALLEY AND THE VIRGINIA/NORTH CAROLINA STATE LINE...ALTHOUGH
ITS HARD TO BE MORE SPECIFIC AT THIS POINT BECAUSE THE BOUNDARY
BECOMES SO DIFFUSE. AT ANY RATE...UPPER RIDGING WILL ALSO SUPPORT A
CONTINUED WARMUP FOR OUR AREA...WITH MID AND UPPER 80S EXPECTED FOR
THE MOUNTAINS...AND UPPER 80S TO LOW 90S FOR THE PIEDMONTS.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 330 PM EDT SUNDAY...
THE UPPER TROUGH BEGINS TO LIFT OUT AS HEIGHTS INCREASE WITH THE
HEARTLAND RIDGE AND THE BERMUDA HIGH JOINING FORCES. THIS WILL
ALLOW THE TEMPERATURE AND DEWPOINT TO CLIMB TOWARDS UNCOMFORTABLE
LEVELS AGAIN INTO NEXT WEEKEND. INITIALLY POP UP STORMS CAN BE
EXPECTED WITH INCREASING INSTABILITY...THEN A BETTER CHANCE OF
THUNDERSTORMS EXISTS AT THE END OF THE FORECAST WITH ANOTHER COLD
FRONT DROPPING OUT OF THE OHIO VALLEY AND GREAT LAKES.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 725 AM EDT MONDAY...
SHOWERS SOUTH OF ROANOKE SHOULD STAY THERE THIS MORNING BUT WILL
SEE COVERAGE INCREASING ACROSS THE MTNS THIS AFTERNOON. HAVE
ENOUGH CONFIDENCE THAT MOST PLACES WILL SEE A SHOWER OR
THUNDERSTORM IN THE VICINITY OF THE TERMINAL FOR A COUPLE HOURS
AFTER 18Z TODAY...EXCEPT MAYBE DANVILLE. STILL WILL MAINLY KEEP
VFR CONDITIONS GOING.
THE FORECAST TONIGHT WILL BE TRICKY AS THE CONVECTION MAY LINGER
THROUGH EARLY MORNING IN THIS REGIME...ALTHOUGH MODELS SHOW LESS
COVERAGE. WITH THIS IN MIND KEPT FOG AT IFR/MVFR AT LWB/BCB WHICH
IS HIGHER VSBY THAN MODELS FORECASTING.
THE DAILY AFTERNOON AND EVENING THREAT OF SHOWERS AND
THUNDERSTORMS CONTINUES THROUGH THE WEEK. GREATEST COVERAGE OF
SHOWER ACTIVITY WILL BE DURING THE AFTERNOON AND EVENING TUESDAY.
OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN CONVECTION...THE ONLY
OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM OVERNIGHT VALLEY FOG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PM/WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
643 AM CDT MON JUL 30 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
309 AM CDT MON JUL 30 2012
MUCH OF THE SHORT TERM FOCUS IS ON TODAYS FORECAST FOR HIGH
TEMPERATURES AND THE CHANCES FOR THUNDERSTORMS THAT COULD PRODUCE
STRONG WINDS.
CURRENTLY...SKIES HAVE MAINLY CLEARED OUT BESIDES SOME HIGH LEVEL
CLOUDS MOVING ACROSS NORTHEAST IOWA AND SOUTHERN WISCONSIN. WITH
A SURFACE RIDGE AXIS OF HIGH PRESSURE IN PLACE FROM THE GREAT
LAKES WEST THROUGH THE REGION...SHALLOW GROUND/VALLEY FOG HAS
FORMED IN MANY LOW LYING AREAS. FURTHER TO THE NORTHWEST...A COLD
FRONT EXTENDS FROM NORTHWEST OF DULUTH TOWARD NORTHEAST SOUTH
DAKOTA. THIS FRONT WILL BE THE FOCUS FOR CONVECTION TODAY AS IT
DIVES SOUTHEAST THROUGH THE REGION.
SOUTHWESTERLY LOW LEVEL WINDS WILL BE ON THE INCREASE TODAY AHEAD
OF THE FRONT WHICH WILL ADVECT WARMER AIR INTO THE REGION. THE
30.00Z NAM IS THE WARMEST OF THE GUIDANCE WITH 850MB TEMPERATURES
OF AROUND +23C AND 925MB TEMPERATURES REACHING +33C BY MID
AFTERNOON. THE 30.00Z GFS/ECMWF/GEM ARE MORE CONSERVATIVE WITH
850MB TEMPS AROUND +20C AND 925MB TEMPS AROUND +27C TO +30C. THE
MAIN LIMITATION TO TEMPERATURES TODAY WILL AGAIN BE WITH CLOUD
COVER...PARTICULARLY THE HIGH LEVEL BAND OF CLOUDS THAT ARE ON THE
EASTERN NOSE OF A MOISTURE FEED THAT COMES OUT OF THE
GULF...ROUNDS THE WESTERN EDGE OF THE MID LEVEL RIDGE THROUGH
ARIZONA AND THEN ROUNDS THE NORTHERN PERIPHERY OF THE RIDGE ACROSS
THE CENTRAL PLAINS ON INTO IOWA. 30.06Z RAP AND 30.00Z NAM/GFS RH
FIELDS SHOW THIS HIGHER CONCENTRATION OF UPPER LEVEL MOISTURE
TRACKING TO THE SOUTHEAST TODAY...WHICH SHOULD LEAVE MAINLY SUNNY
SKIES TODAY AND ALLOW FOR MOST OF THE AREA TO GET INTO THE LOWER 90S.
THE TIMING OF THE COLD FRONT MOVING THROUGH THIS AFTERNOON WILL BE
IDEAL IN TERMS OF COMING THROUGH DURING PEAK DIURNAL HEATING WHEN
INSTABILITY SHOULD BE MAXIMIZED AT ABOUT 2000 J/KG OF SURFACE
BASED CAPE. THE 30.00Z NAM/GFS/ECMWF/GEM ALL ARE IN REASONABLE
AGREEMENT WITH THIS FROPA TIMING ALONG WITH MUCH OF THE REST OF
THE SETUP FOR TODAY. THE BEST LIFT APPEARS TO SHOW UP ACROSS
NORTHERN WISCONSIN THIS AFTERNOON AND IS MAINLY IN THE LOW LEVELS
WITH SOME WEAK 0-2KM CONVERGENCE AND FRONTOGENESIS SHOWING UP FROM
NORTHEAST WISCONSIN TOWARD LA CROSSE BY AROUND 21Z. THE MAIN
LIMITATIONS WILL BE WITH A 850-700MB CAP THAT WILL SUPPRESS MOST
OF THE CONVECTION UNTIL THE AFTERNOON AND WITH A POOR LOW LEVEL
MOISTURE FEED OUT OF THE NORTHERN PLAINS WHICH WILL KEEP THE
COVERAGE OF THE STORMS DOWN. 30.00Z NAM/GFS BUFKIT SOUNDINGS DO
SHOW A FAVORABLE PROFILE FOR STRONG WINDS ONCE THE CAP BREAKS WITH
AN INVERTED V SOUNDING IN THE AFTERNOON. INCREASING 0-3KM SHEAR TO
AROUND 30-40KTS SHOWS UP ACROSS THE CENTRAL PORTION OF WISCONSIN
ALONG THE FRONT...SO THE THREAT APPEARS TO BE THERE THIS AFTERNOON
FOR SEVERE STORMS THAT PRODUCE DAMAGING WINDS ACROSS MAINLY THE
CENTRAL AND EASTERN PORTIONS OF WISCONSIN. CAN NOT RULE OUT SOME
HAIL GIVEN THE AMOUNT OF INSTABILITY...BUT THE MAIN THREAT SHOULD
BE WITH THE WIND. BY 00Z TONIGHT...THE FRONT SHOULD EXTEND FROM
JUST NORTH OF GREEN BAY TO JUST SOUTH OF LA CROSSE AND INTO
NORTHERN ILLINOIS BY MIDNIGHT. PRECIPITATION CHANCE-WISE...THE
MAIN QUESTION IS WITH COVERAGE AND HOW FAR TO THE WEST WILL THE
CONVECTION DEVELOPING INTO THE STRONGER CAP. ANY STORM DEVELOPMENT
WILL BE MORE ISOLATED THE FURTHER WEST YOU GO WITH MORE WIDESPREAD
STORMS LIKELY TOWARD EASTERN WISCONSIN.
AFTER THE FRONT MOVES THROUGH...A RIDGE OF HIGH PRESSURE SETTLES
IN ACROSS THE REGION FOR TUESDAY BEFORE SHIFTING SOUTH A BIT ON
WEDNESDAY. THE NEXT COLD FRONT WILL BE DROPPING DOWN ACROSS THE
UPPER MISSISSIPPI RIVER VALLEY REGION WEDNESDAY NIGHT AND WILL
BRING THE NEXT CHANCES FOR PRECIPITATION ALONG WITH IT.
TEMPERATURES WILL SLOWLY CLIMB AS THE WINDS SHIFT AROUND TO THE
SOUTH ON WEDNESDAY.
.LONG TERM...THURSDAY THROUGH SUNDAY
309 AM CDT MON JUL 30 2012
AN ACTIVE PATTERN WILL CONTINUE INTO THIS WEEKEND WITH THE MAIN
FEATURE BEING A POTENT LOW PRESSURE SYSTEM THAT WILL MOVE THROUGH
ON SATURDAY. BEFORE THAT THOUGH...A MID LEVEL SHORT WAVE TROUGH
WILL DROP DOWN THROUGH THE NORTHWEST FLOW ON THURSDAY WHILE A COLD
FRONT MOVES THROUGH AT THE SURFACE. HIGH PRESSURE WILL BRIEFLY
BUILD IN AT THE SURFACE FOR FRIDAY BEFORE THE MAIN SHOW RAMPS UP
FRIDAY NIGHT INTO SATURDAY. A CLOSED MID LEVEL LOW WILL TRACK
ACROSS SOUTHERN CANADA OVER THIS TIME FRAME WITH A DEEPENING
SURFACE LOW FORMING ACROSS THE DAKOTAS ON FRIDAY. FAIRLY GOOD
AGREEMENT AMONGST THE LONG TERM 30.00Z GUIDANCE WITH THE
POSITION/TIMING OF THE MID LEVEL CUT OFF LOW AND THE SURFACE
LOW/FRONT SETUP. THE WAY THINGS CURRENTLY LOOK...THERE WOULD BE A
COMPLEX OF STORMS THAT WOULD FORM IN THE EASTERN DAKOTAS FRIDAY
WHICH WOULD THEN TRAVEL EAST THROUGH THE REGION INTO SATURDAY
MORNING. THE SURFACE LOW WOULD THEN BE IN AN OCCLUDING STAGE ON
SATURDAY WITH THE WARM SECTOR MAINLY ACROSS EASTERN WISCONSIN AND
THE COLD FRONT NEAR THE MISSISSIPPI RIVER BY 18Z. LOTS OF DETAILS
TO STILL BE HASHED OUT...BUT THIS SYSTEM WILL BRING THE BEST
CHANCES FOR HEAVY RAINFALL OVER THE NEXT WEEK.
&&
.AVIATION...TODAY AND TONIGHT
643 AM CDT MON JUL 30 2012
FORECAST CONCERNS ARE FOCUSED ON NEAR TERM FOG/STRATUS...FRONTAL
PASSAGE THIS AFTERNOON...AND FOG POTENTIAL AGAIN OVERNIGHT.
AS OF 12Z...FOG/STRATUS BEGINNING TO DISSIPATE AT BOTH KRST/KLSE
AND SHOULD COMPLETELY ERODE AROUND 13Z. SURFACE COLD FRONT IS
DRAPED ACROSS NORTH CENTRAL MINNESOTA AND WILL ADVANCE TOWARDS
THE AREA THIS AFTERNOON...CROSSING THE TAF SITES BETWEEN 18Z AND
22Z. ONLY SENSIBLE WEATHER IMPACT IS A NORTHWESTERLY WIND SHIFT...AS
PRECIPITATION CHANCES WILL REMAIN NORTHEAST OF TAF SITES...CLOSER
TO SURFACE LOW AND BETTER FORCING. THERE IS A VERY SMALL CHANCE OF A
SHOWER OR THUNDERSTORM IN THE VICINITY OF KLSE...BUT CONFIDENCE IS
TOO LOW TO INCLUDE IN TAF FORECAST.
HIGH PRESSURE WILL BUILD IN ITS WAKE BY TUESDAY MORNING. GIVEN
WARM RIVER WATER TEMPERATURES AND COOL AIR TEMPERATURES...ANOTHER
ROUND OF FOG/STRATUS WOULD SEEM POSSIBLE. THIS IS ALSO SUGGESTED
BY MOST GUIDANCE...WHICH TAKES CEILINGS AND VISIBILITIES DOWN TO
IFR. HOWEVER...THE SURFACE HIGH POSITION ISN/T THE MOST IDEAL AND
THERE SHOULD BE A STEADY BUT LIGHT NORTHERLY WIND TO KEEP THINGS
MIXED. ALSO...DRIER AIR WORKING IN SHOULD PRECLUDE FOG/STRATUS
FORMING SO FOR NOW HAVE LEFT OUT OF FORECAST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 AM CDT MON JUL 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
220 PM PDT MON JUL 30 2012
.SYNOPSIS...
MONSOON MOISTURE HAS MOVED OVER MOST OF SOUTHWEST CALIFORNIA. THERE
IS A THREAT OF THUNDERSTORMS AND RAINSHOWERS THROUGH WEDNESDAY. THE
CHANCE OF SHOWERS WILL BE WANING DURING THE LATTER HALF OF THE WEEK.
ALONG THE IMMEDIATE COAST AND OVER THE COASTAL WATERS...SOME LATE
NIGHT AND EARLY MORNING LOW CLOUDS AND FOG ARE STILL POSSIBLE.
&&
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...
.EQUIPMENT OUTAGES KNOWN AND PLANNED...
EDWARDS AFB WSR-88D...ETR TUESDAY JULY 31
SAN DIEGO/MIRAMAR WSR-88D...PLANNED OUTAGE TUESDAY 0800-1100 PDT.
&&
.SHORT TERM...
REMAINDER THIS EVENING...
RECENT SATELLITE/RADAR IMAGERY LOOPS INDICATE THE LOW TO MID LEVEL
CIRCULATION OVER IMPERIAL COUNTY STARTING TO LIFT NORTHWARD. WILL
STAY WITH FLASH FLOOD WATCH FOR REMAINDER OF EVENING. RAINFALL
REPORTS/RATES SO FAR ARE IMPRESSIVE FOR REGION...BUT ALSO TYPICAL
FOR PULSE TYPE STORMS IN TROPICAL AIR MASS.THE SURFACE OBS ACROSS
INLAND EMPIRE AND THE HRRR MODEL SHOW ELSINORE CONVERGENCE SETTING
UP ABOUT THIS TIME...2 PM AND CONTINUING THROUGH AT LEAST 6 PM.
STRONG LOW LEVEL MOISTURE ADVECTION HAS BEEN TAKING PLACE THROUGH
THE BANNING PASS WITH DEWPOINTS IN THE 70S AND EAST WINDS 15-25 MPH.
EXPANDED THE COVERAGE AREA FOR TSTMS/SHWRS THIS EVENING TO INCLUDE
MOST OF THE RIVERSIDE COUNTY PORTION OF THE INLAND EMPIRE. OTHERWISE
FORECAST MORE OR LESS UNCHANGED SINCE THE LATE MORNING UPDATE.
TONIGHT THROUGH WEDNESDAY...FROM PREVIOUS DISCUSSION
THE PROXIMITY OF THE LOW/MID LEVEL CIRCULATION WHETHER IT DOES SHIFT
BACK OVER SE CALIFORNIA OR REMAINS BUMPED UP AGAINST THE MOUNTAINS
OF SW CALIFORNIA...THE UPPER LEVEL LOW RETROGRADING BACK OVER SE
CALIFORNIA PER GFS AND EARLIER RUNS OF ECMWF MODEL...AND THE
RESIDUAL MONSOON MOISTURE OVER THE AREA...ALL POINT TO A MOIST AND
CONDITIONALLY UNSTABLE ENVIRONMENT CONTINUING OVER THE EASTERN HALF
OF THE FORECAST AREA. MAY NEED TO CONSIDER ADDITIONAL FLASH FLOOD
WATCHES FOR TUESDAY AND PERHAPS WEDNESDAY.
&&
.LONG TERM...
THURSDAY THROUGH NEXT MONDAY AUGUST 6...
THE SOUTHERN PORTION OF THE EASTERLY WAVE THAT BROUGHT THE MONSOON
MOISTURE TO THE REGION IS CURRENTLY CENTERED ALONG 123W AND SOUTH OF
28N. IT MAKES A LONG CLOCKWISE LOOP AND COMES BACK TO THE OFF THE
CENTRAL CALIFORNIA COAST BY SATURDAY...AND THEN MOVES SLOWLY
NORTHEAST AND INLAND AS A NEGATIVE TILT TROUGH. FOR SOUTHERN
CALIFORNIA THIS WILL BE A DRYING SYNOPTIC PATTERN WITH HIGH PRESSURE
REBUILDING OVER THE AREA. THIS IS SORT OF REFLECTED IN THE CURRENT
FORECASTS.
&&
.AVIATION...
302000Z...COAST/VALLEYS...VFR CONDS WILL PREVAIL THIS AFTN AND
EVENING...WITH INCREASING MID AND HIGH LEVEL CLOUDS THROUGHOUT THE
DAY. STRATUS...WITH BASES AROUND 1000 FT MSL AND TOPS TO 1800 FT
MSL...WILL DEVELOP OVER THE COAST BTWN 08-10Z TONIGHT...AND PUSH
AROUND 10 SM INLAND BY MID TUE MORNING. CONFIDENCE IN STRATUS
DEVELOPMENT OVER KSAN AND KCRQ IS MODERATE...WHILE DEVELOPMENT OVER
KSNA IS LOW. STRATUS WILL CLEAR TOWARDS THE COAST BTWN 16-17Z TUE
MORNING.
MTNS/DESERTS...ISOLATED TO SCATTERED SHOWERS AND TSTMS WILL CONTINUE
TO DEVELOP THIS AFTN AND EVENING. BASES WILL BE AROUND 5000 FT MSL
WITH TOPS TO 35000 FT MSL. LOCALLY GUSTY SFC WINDS AND SMALL HAIL
ARE POSSIBLE WITH THESE STORMS. MOST TSTMS WILL DISSIPATE IN THE
EVENING. HOWEVER...AN ISOLATED TSTM OVERNIGHT IS POSSIBLE.
&&
.FIRE WEATHER...
MONSOON MOISTURE STREAMING THROUGH EAST TO WEST ALIGNED PASSES...AND
INTO INLAND EMPIRE. CABAZON HAS DEWPOINTS IN THE MID 70S WITH EAST
WINDS GUSTING 25 MPH. OTHER RAWS LOCATED NEAR THE SUMMITS AND
PASSES OF RIVERSIDE AND SAN DIEGO COUNTY ARE SHOWING SIMILAR
NUMBERS. ONLY A FEW PLACES ALONG THE MID COASTAL SLOPES IN SAN DIEGO
COUNTY STILL HAVE HUMIDITY BELOW 45 PERCENT...CAPABLE OF SUPPORTING
FIRE SPREADS FROM LIGHTNING STARTS...BUT FURTHER NORTH ACROSS SW SAN
BERNARDINO COUNTY...THERE IS STILL A SLIGHT RISK OF DRY LIGHTNING
STARTS OVER WESTERN HALF OF FIRE WEATHER ZONES CAZ255-CAZ260...SAN
SAN GABRIEL MOUNTAINS AND SAN BERNARDINO MOUNTAINS WEST OF LAKE
ARROWHEAD...VICTOR VALLEY...APPLE VALLEY...LUCERNE VALLEY.
ELSEWHERE...WETTING RAINS WITH AMOUNTS 0.10 TO 0.50 INCHES IN LESS
THAN AN HOUR ARE OCCURRING WITH THE THUNDERSTORMS. MAIN THREAT HERE
WILL BE FLASH FLOODING UNTIL THIS EVENING.
&&
.HYDROLOGY...FROM PREVIOUS DISCUSSION...
THE SATELLITE PRECIPITATION ESTIMATE BRANCH HAS RAINFALL RATES
AROUND 1.5 INCHES ACROSS MOST OF FORECAST AREA. UPSTREAM SOUNDING
TAKEN AT YUMA THIS MORNING SHOWED PRECIPITABLE WATER VALUES OF 2.2
INCHES. GENERAL CONSENSUS OF REGIONAL AND GLOBAL MODELS...
ECMWF/GFS40/NAM12 IS THAT THE HEAVIEST PRECIPITABLE WATER WILL MOVE
BACK TOWARDS THE EAST AND AWAY FROM FORECAST AREA AFTER 4PM. FLASH
FLOOD WATCH CONTINUES UNTIL 2200 PDT.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...UPDATED
CA...FLASH FLOOD WATCH UNTIL 10 PM PDT THIS EVENING FOR THE
COACHELLA VALLEY...RIVERSIDE COUNTY MOUNTAINS...SAN DIEGO
COUNTY DESERTS...SAN DIEGO COUNTY MOUNTAINS.
PZ...NONE.
&&
$$
PUBLIC/FIRE WEATHER...BALFOUR
SHORT TERM WARNINGS...MOEDE
AVIATION/MARINE...JJT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
323 PM MDT MON JUL 30 2012
.SHORT TERM...
(TONIGHT AND TUESDAY)
...MORE INTENSE THUNDERSTORMS TODAY BRINGING THREAT OF HEAVY RAIN TO
PORTIONS OF SOUTH CENTRAL AND SOUTHEAST COLORADO...
UPPER HIGH TO THE SOUTH CONTINUES TO NUDGE THE MAIN TAP OF THE
MONSOON PLUME FARTHER WEST AND NORTH...HOWEVER...YESTERDAY`S FRONT
HAS COMPENSATED SOME WITH AN INCREASE IN LOW LEVEL MOISTURE. THIS
HAS RESULTED IN HIGHER CAPES TODAY ACROSS THE SOUTHEAST
MTS/PLAINS...AND STORMS ON RADAR HAVE DEFINITELY BEEN STRONGER.
CAPE VALUES OFF SPC MESONET SHOWING VALUES SHOWING AROUND 1000-2000
J/KG...THOUGH WITH A LITTLE MIXING...THEY MAY DROP BACK TO AROUND
1000-1500 J/KG. DEEP LAYER SHEARS ARE RUNNING AROUND 20-30KTS...SO
SHOULD NOT LOOKING AT A WIDESPREAD SEVERE RISK...BUT CERTAINLY SOME
STORMS COULD PULSE UP AND PRODUCE HAIL TO AROUND 1 INCH IN
DIAMETER...ESPECIALLY OVER/NEAR THE HIGHER TERRAIN. HRRR BRINGS SEVERAL WAVES
OF THUNDERSTORMS OFF THE SOUTHEAST MTS...PARTICULARLY ACROSS THE
PIKES PEAK REGION WITH THUNDERSTORMS SPREADING OFF INTO THE
SOUTHEAST PLAINS DURING THE EVENING. STORM MOTIONS OFF RADAR HAVE
BEEN TO THE EAST NORTHEAST AROUND 10-15 MPH...HOWEVER WITH CONTINUAL
REGENERATION...IF STORMS TRACK OVER THE SAME LOCATION...LOCALLY
HEAVY RAINFALL WITH THE POTENTIAL FOR FLASH FLOODING WILL BE A
CONCERN...ESPECIALLY FOR THE WALDO CANYON BURN SCAR. ONE STORM HAS ALREADY
COME FAIRLY CLOSE...THOUGH JUST MISSED TO THE SOUTH. HRRR SHOWS
ANOTHER LINE OF THUNDERSTORMS MOVING OFF THE PIKES PEAK REGION AND
POTENTIAL AFFECTING THE BURN SCAR AROUND 22-23Z. GIVEN THAT STORMS
ARE STRONGER TODAY...AND CAPABLE OF HIGHER RAINFALL RATES (UP TO 1.5
INCH PER HOUR)...FLOODING ON THE WALDO CANYON BURN SCAR IS A GREATER
CONCERN. HOWEVER...STORMS WILL STILL BE HIT OR MISS...SO CLOSE
MONITORING OF THE BURN SCAR WILL CONTINUE.
FOR TONIGHT...MODELS IN GENERAL AGREEMENT SPREADING THUNDERSTORMS
EASTWARD ACROSS THE PLAINS THROUGH THE EVENING BEFORE DIMINISHING
TOWARDS MORNING. TUESDAY LOOKS LIKE A SIMILAR EVENT TO TODAY...WITH
LOW LEVEL MOISTURE STILL IN PLACE...BUT MAIN MONSOON PLUME SHIFTED
FARTHER WEST AND NORTH. MAIN TRACK OF ANY SHORTWAVES AROUND THE
PERIPHERY OF THE UPPER RIDGE MAY BE FARTHER NORTH AS WELL...BUT WITH
CONVECTIVE HEATING...MODELS BREAK OUT ANOTHER ROUND OF SCATTERED
THUNDERSTORMS ACROSS THE MOUNTAINS AREAS...WITH GREATEST COVERAGE
ACROSS THE SOUTHEAST MTS. CAPES WILL PROBABLY END UP BEING SIMILAR
TODAY...SO SMALL HAIL AND HEAVY RAINFALL WILL BE THE PRIMARY
THREATS. FLASH FLOODING ON THE WALDO CANYON BURN SCAR WILL BE A
CONCERN ONCE AGAIN.
.LONG TERM...
(TUESDAY NIGHT THROUGH NEXT MONDAY)
TEMPERATURES AND POPS ARE THE PRIMARY METEOROLOGICAL ISSUES DURING
THE LONGER TERM. RECENT COMPUTER MODELS SUGGEST THAT UPPER HIGH
CENTERED OVER THE TEXAS PANHANDLE AT 00Z WEDNESDAY ATTEMPTS TO SLOWLY
SHIFT INTO CENTRAL OKLAHOMA BY 12Z SATURDAY BEFORE PUSHING BACK
INTO THE TEXAS PANHANDLE REGION BY NEXT MONDAY.
FAVORABLE ATMOSPHERIC MOISTURE/HIGH PRECIPITABLE WATER VALUES/MONSOONAL
PLUME ROTATING AROUND THE UPPER HIGH WILL CONTINUE TO IMPACT THE
FORECAST DISTRICT AT TIMES THROUGH THE LONGER TERM. IN
ADDITION...INCREASING SHORT-WAVE ACTIVITY AS WELL AS SEVERAL
NORTHERLY SURGES ARE PROJECTED TO IMPACT THE FORECAST DISTRICT AT
TIMES FROM TUESDAY NIGHT INTO AT LEAST THE UPCOMING WEEKEND.
AS DISCUSSED DURING PREVIOUS DISCUSSIONS...ISOLATED TO SCATTERED
PRIMARILY AFTERNOON AND EVENING THUNDERSTORMS(SOME CONTAINING
LOCALLY HEAVY RAIN AND HAIL) ARE ANTICIPATED OVER MANY SECTIONS OF
THE FORECAST DISTRICT AT TIMES DURING THE LONGER TERM.
AS ALWAYS...PLEASE REMEMBER THAT THE STRONGER STORMS DURING THE
LONGER TERM WILL BE CAPABLE OF PRODUCING LOCALLY HEAVY RAIN AND
FLASH FLOODING POTENTIAL(ESPECIALLY OVER BURN SCAR REGIONS SUCH AS
THE WALDO CANYON BURN SCAR). WFO PUEBLO WILL CONTINUE TO MONITOR
CLOSELY.
FINALLY...MAXIMUM AND MINIMUM TEMPERATURES DURING THE LONGER TERM
SHOULD CONTINUE TO RUN AT TO ABOVE EARLY AUGUST CLIMATOLOGICAL
AVERAGES IN COMBINATION WITH GENERALLY LOW-GRADE GRADIENT WINDS.
&&
.AVIATION...
TSRA WILL BE MOST LIKELY TO IMPACT THE COS TAF SITE THIS
EVENING...WITH HEAVY RAIN...AND ERRATIC GUSTY WINDS UP TO 45 KTS THE
PRIMARY THREAT. SOME SMALL HAIL WILL ALSO BE POSSIBLE. LESS OF A
CHANCE FOR -TSRA TO AFFECT THE KPUB AND KALS TAF SITE...SO WILL
MAINTAIN VCTS IN TAFS THERE. WINDS SHOULD SHIFT OUT OF THE NORTH TO
NORTHWEST WITH CONVECTIVE OUTFLOWS SPREADING OFF THE MOUNTAINS
DURING THE 23-00Z TIME FRAME FOR KCOS AND KPUB. WINDS AND
THUNDERSTORMS SHOULD DIMINISH THROUGH THE EVENING. ANOTHER ROUND OF
THUNDERSTORMS WILL BE POSSIBLE AGAIN ON TUESDAY...WITH KCOS UNDER
THE GREATEST RISK FOR -TSRA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
636 PM EDT MON JUL 30 2012
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OFF THE NEW ENGLAND COAST WILL SLOWLY DRIFT
SOUTHEAST AND MERGE WITH THE BERMUDA HIGH PRESSURE SYSTEM IN THE
WESTERN ATLANTIC. A COLD FRONT MOVING THROUGH THE GREAT LAKES ON
TUESDAY AND WEDNESDAY IS EXPECTED TO DISSIPATE BEFORE REACHING OUR
FORECAST AREA. ANOTHER COLD FRONT MOVING THROUGH THE GREAT LAKES
ON FRIDAY IS EXPECTED TO SUFFER A SIMILAR FATE EARLY ON THE
WEEKEND. A THIRD AND PLAUSIBLY STRONGER COLD FRONT IS FORECAST TO
REACH THE APPALACHIANS ABOUT MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE OVERALL SYNOPTIC PATTERN REMAINS WEAK WITH HIGH PRESSURE WELL
OFFSHORE AND LOW PRESSURE ACROSS THE NORTHERN GREAT LAKES. IT`S MUCH
THE SAME ALOFT, WEAK THAT IS. MOISTURE REMAINS RATHER ABUNDANT IN
THE LOWER LEVELS, HENCE ALL THE LOW CLOUDS ACROSS THE CWA,
ESPECIALLY EASTERN PA WHERE UPSLOPE FLOW IS BEING MAXIMIZED.
OUTSIDE OF THE SCATTERED SHOWERS FIRING WEST OF A READING,
ALLENTOWN, MOUNT POCONO LINE, PRECIPITATION IS ISOLATED. THE
PRECIPITATION IS SLOWLY DRIFTING TO THE NORTH/NORTHEAST, A MUCH
DIFFERENT ROAD THEN THE HIGH RESOLUTION HRRR SUGGESTS.
TEMPERATURES SHOULD SETTLE INTO THE 60S TONIGHT IN MOST SPOTS.
CENTER CITY COULD STILL REMAIN IN THE LOW 70S AND THE SOUTHERN
POCONOS COULD SEE SOME UPPER 50S.
THE SHOWERS AN THUNDERSTORMS WILL DISSIPATE THIS EVENING, BUT
LIKE LAST NIGHT, LOW CLOUDS WILL RETURN, PROBABLY A LITTLE EARLIER
AND A LITTLE THICKER AS THE LIGHT ONSHORE FLOW PERSISTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
LOOKS LIKE LOTS OF CLOUDS TO START THE DAY. THEN AFTER JUST A LITTLE
BIT OF SUN, WE HAVE CHANCE POPS IN THE FORECAST AS THE MID LEVEL
TROF APPROACHES FROM THE WEST. IT APPEARS THE FOCUS OF THE
THUNDERSTORM ACTIVITY WILL BE WELL WEST OF THE CWA.
WITH ALL THE CLOUD COVER IN PLACE TOMORROW, HIGHS WILL RANGE FROM
THE UPPER 70S ACROSS THE POCONOS TO THE MID 80S ACROSS THE
DELAWARE VALLEY AND ALL POINTS SOUTH AND EAST.
WINDS WILL REMAIN ON THE LIGHT SIDE AND MAINLY FROM THE EAST,
PROBABLY MORE NORTHEAST TOMORROW MORNING AND MORE SOUTHEAST
TOMORROW AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE GENERAL EVOLUTION OF THIS LONG TERM PERIOD IS A TRANSITION FROM
TROFINESS ALONG THE EASTERN SEABOARD TO A MORE ZONAL FLOW.
UNFORTUNATELY THE FORECAST SOUNDINGS ARE NOT SHOWING ENOUGH OF A CAP
TO FORECAST A DRY DAY (FRIDAY MIGHT BECOME THE ONE). HIGHEST POPS
ARE CONCENTRATED WHEN THE COLD FRONTS RUNNING ON FUMES ATTEMPT TO
PASS THROUGH OUR CWA ON WEDNESDAY AND SATURDAY. HIGHER POPS ARE THEN
WITH THE NEXT (STRONGER?) CFP LATER SUNDAY INTO MONDAY. WITH THE
RETURN OF ZONAL FLOW, TEMPERATURES WILL RESPOND AGAIN WITH MORE 90S
IN STORE. WHILE THE FRONTS PER-SE DON`T MAKE IT, THEY OFFER THE
OPPORTUNITY OF FILTERING IN SOME DRIER AIR INTO THE REGION AND ALSO
BY THEIR FCST THICKNESS FIELDS TRY TO KEEP A STATUS-QUO ON THE
HEAT. RIGHT NOW THE HEAT LOOKS LESS OPPRESSIVE THAN SOME OF THE
HOT SPELLS WE HAVE ALREADY HAD THIS SUMMER. REGARDLESS WE MIGHT
STILL REACH ADVISORY LEVELS, ESPECIALLY IN THE MORE URBANIZED
PARTS OF OUR CWA.
THE GFS INITIALIZATION AT 500MB WAS BETTER THAN THE WRF-NMMB. THE
WRF-NMMB WAS TOO SHARP WITH THE EASTERN TROF AND SUBSEQUENTLY
PRODUCED A STRONGER AND MORE CLOSER TO THE COAST LOW WHICH WE ARE
NOT FOLLOWING AT THE START OF THE LONG TERM. BEYOND THAT TOO MUCH
DAMAGE IS DONE FOR MODEL RECOVERY AND THE 12Z GFS IS GIVING US A
MIDDLE OF THE ROAD SOLUTION LOOKING AT ALL OF THE MEDIUM RANGE
MODELS.
AT THE START OF THE LONG TERM TUESDAY NIGHT, WE CARRY SOME CHANCES
ASSOCIATED WITH THE DEPARTING OFFSHORE LOW TO THE EAST AND THE
POSSIBILITY OF RESIDUAL SHOWERS AND THUNDERSTORMS ASSOCIATED WITH
THE SHORT WAVE OF THE FIRST COLD FRONT APPROACHING FROM THE WEST.
ON WEDNESDAY WE SUPPOSE IF THE WRF-NMMB ENDS UP BEING RIGHT FOR THE
WRONG REASON, POPS MAY BE OVERDONE EAST BECAUSE OF SUBSIDENCE
BETWEEN SYSTEMS. BUT, OTHER THAN LATER SUNDAY AND THAT IS FRAUGHT WITH
UNCERTAINTIES BECAUSE ITS DAY 6 AND A HALF THIS APPEARS TO BE THE
"GO TO" DAY FOR CONVECTION AND HEAVY RAIN IN OUR CWA. FORECAST BULK
SHEAR VALUES ARE LOW. NOT TERRIBLY SOLD THAT A EML CAN SURVIVE
UNSCATHED AS THE GFS IS FORECASTING. BUT THE COMBINATION OF ROBUST
CAPE, SOME DECREASE OF THETA E WITH HEIGHT WOULD BE ENOUGH FOR
PULSE TYPE STRONG TO MAYBE SEVERE STORMS. WITH SREF PWATS NEARING
1.75 INCHES AND ENVIRONMENTAL WINDS GENERALLY LIGHT SOME HEAVY
DOWNPOURS ARE ALSO POSSIBLE. THE MORE LIKELY GEOGRAPHIC AREAS ARE
WEST BECAUSE THE FRONT SHOULD STILL BE STRONGER AND FARTHER AWAY
FROM ANY OFFSHORE LOW INFLUENCE. BECAUSE OF THE LATTER ERRORS WITH
THE WRF-NMMB, WARMER GFS PREFERRED FOR MAX TEMPS.
WE WILL LOWER OUR CHANCES WEDNESDAY NIGHT PARTLY BECAUSE OF DIURNAL
CONSIDERATIONS, BUT ALSO BECAUSE OF THE FORECAST POSITION OF THE
LONG WAVE TROF PASSING THROUGH OUR CWA.
MODELS ARE SHOWING MORE OF A CHANCE OF THUNDERSTORMS EAST WITH
RESIDUAL HIGHER THETA E VALUES. OVERALL WITH WARMER TEMPS FCST
ALOFT AS THE TROF MOVES EAST THE GENERAL COVERAGE AND STRENGTH OF
THE TSTMS SHOULD BE LESS. BECAUSE MOST OF THE MODELS ARE SHOWING
SOME "COOLING" BELOW 700MB, WE WENT SLIGHTLY LOWER THAN GFS MOS WITH
MAX TEMPS.
IF THERE IS GOING TO BE A PREVAILING DRY DAY (WITH RESPECT TO POPS),
IT MAY BE FRIDAY AS THE NEXT FRONT IS GEOGRAPHICALLY FORECAST TO BE
TOO FAR AWAY AND THERE IS FORECAST NVA IN THE ZONAL FLOW. RIGHT NOW
ONLY ISOLATED POPS WERE CARRIED AND MAINLY INLAND AND NORTH OF THE
MASON-DIXON LINE. GENERAL MODEL AGREEMENT OF A HOTTER DAY WITH
POSSIBLY SOME LOWER DEW POINTS BECAUSE MORE OF A WESTERLY FLOW ALOFT.
THE NEXT REMNANT FRONTAL IMPULSE SHOULD COME IN FRIDAY NIGHT OR
SATURDAY WHERE WE INCREASE POPS AGAIN. NOT COUNTING ON CLOUDS KEEPING
TEMPS DOWN, SO HERE WE WENT ABOVE GFS MOS GUIDANCE. THE NEXT FRONT
IS FORECAST TO APPROACH ON SUNDAY AND MONDAY WITH MODEL TIMING
DIFFERENCES. WE NORMALLY PREFER THE SLOWER ENVELOPE OF SOLUTIONS IN
THE MIDDLE OF THE SUMMER AS THESE TYPICALLY WORK BETTER. SO POPS MAY
BE TOO AGGRESSIVE ON SUNDAY AND OPTIMISTIC FOR MONDAY. MORE 90
DEGREE DAYS ARE POSSIBLE AS PER FCST 925MB TEMPS. MONDAY IS ONE OF
THOSE DAYS WHERE WE SHOULD HIT 90 ALONG THE COASTAL PLAIN EVEN IF
THE FRONT MOVES THROUGH WITH DOWNSLOPING FLOW AS SUB 15C 850MB
TEMPS ARE STILL FORECAST TO BE JUST GETTING TO THE EASTERN GREAT
LAKES IN THE MORNING.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THE MAIN ISSUE DURING THIS FORECAST PERIOD IS GOING TO BE THE LOW
CLOUDS DEVELOPING TONIGHT. CURRENTLY, THERE ARE A FEW SHOWERS AND
THUNDERSTORMS NEAR KRDG, BUT THEY ARE ON THE LIGHTER/LESS INTENSE
SIDE.
WITH THE ONSHORE FLOW CONTINUING THROUGH THE NIGHT. MOISTURE WILL
INCREASE AND POOL OVER THE TERMINALS, ESPECIALLY THE ONES IN
EASTERN PA. MVFR IS A REAL GOOD BET BY 07Z TONIGHT FOR ALL THE
TERMINALS. IFR LOOKS QUITE POSSIBLE FOR KRDG AND KABE BEFORE
DAYBREAK. LOOKS LIKE MORE OF A LOW CEILING ISSUE THAN VISIBILITY
ISSUE.
WINDS REMAIN OUT OF THE EAST TOMORROW, PROBABLY MORE NORTHEAST IN
THE MORNING AND MORE SOUTHEAST IN THE AFTERNOON. LOOKS LIKE A
MVFR/VFR TYPE OF DAY WITH SCATTERED SHOWERS AND THUNDERSTORMS.
OUTLOOK...
TUESDAY NIGHT...VFR...CHANCE OF MVFR CIGS AND VSBYS MAINLY NORTH.
WEDNESDAY AND WEDNESDAY NIGHT...PRIMARILY VFR, EXCEPT MVFR TO
LOCALLY IFR IN SCATTERED SHOWERS AND THUNDERSTORMS AND FOG LATE.
THURSDAY THROUGH FRIDAY NIGHT...VFR, ISOLATED MVFR CONDITIONS IN
EARLY MORNING FOG AND MORE ISOLATED (VS WEDNESDAY) SHOWERS AND
THUNDERSTORMS.
SATURDAY...PRIMARILY VFR, BUT INCREASE CHANCES OF MVFR CONDITIONS
IN GREATER COVERAGE SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
FAIRLY TRANQUIL ACROSS AREA WATERS THE NEXT 24 HOURS. SOUTHEAST
WINDS TONIGHT WILL GO MORE NORTHEAST TOMORROW MORNING AND THEN
BACK TO SOUTHEAST TOMORROW IN THE AFTERNOON.
SEAS WILL BE AROUND 2 FEET ON THE OCEAN AND 1 TO 2 FEET ON THE BAY.
OUTLOOK...
WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH THE OUTLOOK PERIOD. WE ARE FOLLOWING THE WEAKER
OFFSHORE LOW SOLUTIONS AT THE START OF THE OUTLOOK PERIOD AS PER
PMDHMD AND A BETTER INITIALIZATION BY THE GFS (WHICH ALSO HAS WEAKER
LOWS). THUS BOTH LOWS ARE EXPECTED TO TRACK FARTHER OFFSHORE AND NOT
GENERATE ENOUGH WINDS AND SWELLS UP TO SMALL CRAFT ADVISORY CRITERIA.
BEYOND THAT, A PAIR OF COLD FRONTS ARE FORECAST TO DISSIPATE BEFORE
REACHING THE AREA WATERS ABOUT WEDNESDAY AND AGAIN ABOUT SATURDAY. A
STRONGER FRONT AS OF NOW IS FORECAST TO APPROACH BEYOND THE END OF
OUR DETERMINISTIC FORECAST PERIOD. THE PREVAILING SOUTHERLY TO
SOUTHWESTERLY FLOW IS NOT EXPECTED TO BE STRONG ENOUGH TO PRODUCE
SMALL CRAFT ADVISORY WINDS OR SWELLS INTO SATURDAY NIGHT.
&&
.TIDES/COASTAL FLOODING...
GFS ET-SURGE GUIDANCE, AND CURRENT POSITIVE 1/2 FOOT TIDAL DEPARTURES
INDICATE THE ATLC OCEAN FRONTS OF NJ/DE WOULD SEE NEAR MARGINAL
"MINOR" TIDAL INUNDATION FLOODING WITHIN 1/2 HR OF THE NEXT THREE EVENING
HIGH TIDE AS WE APPROACH FULL MOON. THE COASTAL FLOOD STATEMENT
WAS EXPANDED TO INCLUDE THE UPPER DELAWARE BAY. REEDY POINT IS
RUNNING ABOUT 1 FOOT ABOVE PREDICTED EARLY THIS EVENING. HIGH TIDE
OCCURS IN ABOUT 3 HOURS...AND THIS TYPE OF DEPARTURE WOULD BRING
THE HIGH TIDE AT REEDY POINT CLOSE TO THE MINOR TIDAL FLOODING
BENCHMARK.
&&
.RIP CURRENTS...
FOR THE REMAINDER OF THE DAY, SOUTHEAST WINDS AROUND 10 KNOTS CAN
BE EXPECTED. WAVE HEIGHTS IN THE SURF ARE FORECAST TO RANGE FROM
2 TO 3 FEET. A CONTINUED SOUTHEAST SWELL WITH AN 11 SECOND PERIOD
SHOULD RESULT IN A MODERATE RISK OF RIP CURRENTS.
&&
.CLIMATE...
IN TERMS OF 90 DEGREE DAYS FOR THE MONTH OF JULY.
AT PHILADELPHIA 21 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
HIGHER OCCURRED THROUGH THE 29TH. THIS TIES THE RECORD FOR
THE MOST NUMBER OF 90 DEGREES DAYS ALL TIME WITH 1952, 1988, 1995
AND 2011.
AT ALLENTOWN 15 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR HIGHER
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1983, 2010 AND
2011. GREATEST IS 20 DAYS IN 1999, 1966 AND 1955.
AT WILMINGTON 17 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1952. GREATEST
IS 22 DAYS IN 1894.
AT ATLANTIC CITY 14 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
MORE OCCURRED THROUGH THE 29TH. THIS IS FIFTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 2010. GREATEST IS
21 DAYS IN 1983.
AT READING 19 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SECOND ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY. GREATEST IS 20 DAYS
SET IN 2011, 2010, 1999 AND 1955.
IN TERMS OF WARMEST AVERAGE TEMPERATURE RECORDED FOR THE MONTH OF
JULY.
AT PHILADELPHIA THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH
WAS 81.9. THIS IS THE THE THIRD WARMEST JULY ON RECORD BEHIND 1994
AND 2011.
AT WILMINGTON THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH WAS
80.5. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2011 AND 1955.
AT ATLANTIC CITY THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH
WAS 78.8. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2010 AND
2011.
AT ALLENTOWN THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH WAS
77.6 AND IS THE SEVENTH WARMEST JULY ON RECORD.
DATA SINCE 6/28...32 DAYS.
RDG ONLY 2 DAYS BELOW NORMAL
PHL/ABE/GED ONLY 3 DAYS BELOW NORMAL
TTN 4 DAYS BELOW NORMAL
MPO 5 DAYS BELOW NORMAL
ILG 6 DAYS BELOW NORMAL
ACY 9 DAYS BELOW NORMAL
90 OR HIGHER FOR THE SEASON
SO FAR TOTAL
NORMAL THIS YR LAST YR POR
ABE 17 24 21 1922
ACY 22 31
GED 29 40
ILG 27 27
PHL 21 30 33 1874
RDG 30 30
TTN 25 26
MPO 3 4
THE NORMAL AND PERIOD OF RECORD /POR/ IS LISTED FOR ONLY TWO CLIMATE
SITES WHERE THE DATASET IS EASILY AVAILABLE AND COMPLETE.
WITH RESPECT TO OCCURRENCES OF 95 OR GREATER PHL CLIMATOLOGICALLY
AVG`S 4/YR SO FAR THIS YR 12 LAST YRS TOTAL 11.
STATISTICALLY FOR PHL AS EVALUATED BY MARK DELISI...THE NUMBER OF 95
OR WARMER DAYS THIS YEAR IS UNUSUAL.
FOR OUR FORECAST AREA...
PCPN FOR THE MONTH SO FAR NOW GENERALLY WITHIN 75 PCT OF NORMAL.
TEMP FOR THE MONTH SO FAR NOW GENERALLY 2.5 TO 5F ABOVE NORMAL.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI
NEAR TERM...KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...GIGI
AVIATION...DRAG/GIGI/KRUZDLO
MARINE...GIGI/KRUZDLO
TIDES/COASTAL FLOODING...KRUZDLO/HAYES
RIP CURRENTS...DRAG/KRUZDLO
CLIMATE...CARDINALE/DRAG/GAINES
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
329 PM EDT MON JUL 30 2012
.SYNOPSIS...
A HIGH PRESSURE SYSTEM OFF THE NEW ENGLAND COAST WILL SLOWLY DRIFT
SOUTHEAST AND MERGE WITH THE BERMUDA HIGH PRESSURE SYSTEM IN THE
WESTERN ATLANTIC. A COLD FRONT MOVING THROUGH THE GREAT LAKES ON
TUESDAY AND WEDNESDAY IS EXPECTED TO DISSIPATE BEFORE REACHING OUR
FORECAST AREA. ANOTHER COLD FRONT MOVING THROUGH THE GREAT LAKES
ON FRIDAY IS EXPECTED TO SUFFER A SIMILAR FATE EARLY ON THE
WEEKEND. A THIRD AND PLAUSIBLY STRONGER COLD FRONT IS FORECAST TO
REACH THE APPALACHIANS ABOUT MONDAY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE OVERALL SYNOPTIC PATTERN REMAINS WEAK WITH HIGH PRESSURE WELL
OFFSHORE AND LOW PRESSURE ACROSS THE NORTHERN GREAT LAKES. IT`S MUCH
THE SAME ALOFT, WEAK THAT IS. MOISTURE REMAINS RATHER ABUNDANT IN
THE LOWER LEVELS, HENCE ALL THE LOW CLOUDS ACROSS THE CWA,
ESPECIALLY EASTERN PA WHERE UPSLOPE FLOW IS BEING MAXIMIZED.
OUTSIDE OF THE SCATTERED SHOWERS FIRING WEST OF A READING,
ALLENTOWN, MOUNT POCONO LINE, PRECIPITATION IS ISOLATED. THE
PRECIPITATION IS SLOWLY DRIFTING TO THE NORTH/NORTHEAST, A MUCH
DIFFERENT ROAD THEN THE HIGH RESOLUTION HRRR SUGGESTS.
TEMPERATURES SHOULD SETTLE INTO THE 60S TONIGHT IN MOST SPOTS.
CENTER CITY COULD STILL REMAIN IN THE LOW 70S AND THE SOUTHERN
POCONOS COULD SEE SOME UPPER 50S.
THE SHOWERS AN THUNDERSTORMS WILL DISSIPATE THIS EVENING, BUT
LIKE LAST NIGHT, LOW CLOUDS WILL RETURN, PROBABLY A LITTLE EARLIER
AND A LITTLE THICKER AS THE LIGHT ONSHORE FLOW PERSISTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
LOOKS LIKE LOTS OF CLOUDS TO START THE DAY. THEN AFTER JUST A LITTLE
BIT OF SUN, WE HAVE CHANCE POPS IN THE FORECAST AS THE MID LEVEL
TROF APPROACHES FROM THE WEST. IT APPEARS THE FOCUS OF THE
THUNDERSTORM ACTIVITY WILL BE WELL WEST OF THE CWA.
WITH ALL THE CLOUD COVER IN PLACE TOMORROW, HIGHS WILL RANGE FROM
THE UPPER 70S ACROSS THE POCONOS TO THE MID 80S ACROSS THE
DELAWARE VALLEY AND ALL POINTS SOUTH AND EAST.
WINDS WILL REMAIN ON THE LIGHT SIDE AND MAINLY FROM THE EAST,
PROBABLY MORE NORTHEAST TOMORROW MORNING AND MORE SOUTHEAST
TOMORROW AFTERNOON.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
THE GENERAL EVOLUTION OF THIS LONG TERM PERIOD IS A TRANSITION FROM
TROFINESS ALONG THE EASTERN SEABOARD TO A MORE ZONAL FLOW.
UNFORTUNATELY THE FORECAST SOUNDINGS ARE NOT SHOWING ENOUGH OF A CAP
TO FORECAST A DRY DAY (FRIDAY MIGHT BECOME THE ONE). HIGHEST POPS
ARE CONCENTRATED WHEN THE COLD FRONTS RUNNING ON FUMES ATTEMPT TO
PASS THROUGH OUR CWA ON WEDNESDAY AND SATURDAY. HIGHER POPS ARE THEN
WITH THE NEXT (STRONGER?) CFP LATER SUNDAY INTO MONDAY. WITH THE
RETURN OF ZONAL FLOW, TEMPERATURES WILL RESPOND AGAIN WITH MORE 90S
IN STORE. WHILE THE FRONTS PER-SE DON`T MAKE IT, THEY OFFER THE
OPPORTUNITY OF FILTERING IN SOME DRIER AIR INTO THE REGION AND ALSO
BY THEIR FCST THICKNESS FIELDS TRY TO KEEP A STATUS-QUO ON THE
HEAT. RIGHT NOW THE HEAT LOOKS LESS OPPRESSIVE THAN SOME OF THE
HOT SPELLS WE HAVE ALREADY HAD THIS SUMMER. REGARDLESS WE MIGHT
STILL REACH ADVISORY LEVELS, ESPECIALLY IN THE MORE URBANIZED
PARTS OF OUR CWA.
THE GFS INITIALIZATION AT 500MB WAS BETTER THAN THE WRF-NMMB. THE
WRF-NMMB WAS TOO SHARP WITH THE EASTERN TROF AND SUBSEQUENTLY
PRODUCED A STRONGER AND MORE CLOSER TO THE COAST LOW WHICH WE ARE
NOT FOLLOWING AT THE START OF THE LONG TERM. BEYOND THAT TOO MUCH
DAMAGE IS DONE FOR MODEL RECOVERY AND THE 12Z GFS IS GIVING US A
MIDDLE OF THE ROAD SOLUTION LOOKING AT ALL OF THE MEDIUM RANGE
MODELS.
AT THE START OF THE LONG TERM TUESDAY NIGHT, WE CARRY SOME CHANCES
ASSOCIATED WITH THE DEPARTING OFFSHORE LOW TO THE EAST AND THE
POSSIBILITY OF RESIDUAL SHOWERS AND THUNDERSTORMS ASSOCIATED WITH
THE SHORT WAVE OF THE FIRST COLD FRONT APPROACHING FROM THE WEST.
ON WEDNESDAY WE SUPPOSE IF THE WRF-NMMB ENDS UP BEING RIGHT FOR THE
WRONG REASON, POPS MAY BE OVERDONE EAST BECAUSE OF SUBSIDENCE
BETWEEN SYSTEMS. BUT, OTHER THAN LATER SUNDAY AND THAT IS FRAUGHT WITH
UNCERTAINTIES BECAUSE ITS DAY 6 AND A HALF THIS APPEARS TO BE THE
"GO TO" DAY FOR CONVECTION AND HEAVY RAIN IN OUR CWA. FORECAST BULK
SHEAR VALUES ARE LOW. NOT TERRIBLY SOLD THAT A EML CAN SURVIVE
UNSCATHED AS THE GFS IS FORECASTING. BUT THE COMBINATION OF ROBUST
CAPE, SOME DECREASE OF THETA E WITH HEIGHT WOULD BE ENOUGH FOR
PULSE TYPE STRONG TO MAYBE SEVERE STORMS. WITH SREF PWATS NEARING
1.75 INCHES AND ENVIRONMENTAL WINDS GENERALLY LIGHT SOME HEAVY
DOWNPOURS ARE ALSO POSSIBLE. THE MORE LIKELY GEOGRAPHIC AREAS ARE
WEST BECAUSE THE FRONT SHOULD STILL BE STRONGER AND FARTHER AWAY
FROM ANY OFFSHORE LOW INFLUENCE. BECAUSE OF THE LATTER ERRORS WITH
THE WRF-NMMB, WARMER GFS PREFERRED FOR MAX TEMPS.
WE WILL LOWER OUR CHANCES WEDNESDAY NIGHT PARTLY BECAUSE OF DIURNAL
CONSIDERATIONS, BUT ALSO BECAUSE OF THE FORECAST POSITION OF THE
LONG WAVE TROF PASSING THROUGH OUR CWA.
MODELS ARE SHOWING MORE OF A CHANCE OF THUNDERSTORMS EAST WITH
RESIDUAL HIGHER THETA E VALUES. OVERALL WITH WARMER TEMPS FCST
ALOFT AS THE TROF MOVES EAST THE GENERAL COVERAGE AND STRENGTH OF
THE TSTMS SHOULD BE LESS. BECAUSE MOST OF THE MODELS ARE SHOWING
SOME "COOLING" BELOW 700MB, WE WENT SLIGHTLY LOWER THAN GFS MOS WITH
MAX TEMPS.
IF THERE IS GOING TO BE A PREVAILING DRY DAY (WITH RESPECT TO POPS),
IT MAY BE FRIDAY AS THE NEXT FRONT IS GEOGRAPHICALLY FORECAST TO BE
TOO FAR AWAY AND THERE IS FORECAST NVA IN THE ZONAL FLOW. RIGHT NOW
ONLY ISOLATED POPS WERE CARRIED AND MAINLY INLAND AND NORTH OF THE
MASON-DIXON LINE. GENERAL MODEL AGREEMENT OF A HOTTER DAY WITH
POSSIBLY SOME LOWER DEW POINTS BECAUSE MORE OF A WESTERLY FLOW ALOFT.
THE NEXT REMNANT FRONTAL IMPULSE SHOULD COME IN FRIDAY NIGHT OR
SATURDAY WHERE WE INCREASE POPS AGAIN. NOT COUNTING ON CLOUDS KEEPING
TEMPS DOWN, SO HERE WE WENT ABOVE GFS MOS GUIDANCE. THE NEXT FRONT
IS FORECAST TO APPROACH ON SUNDAY AND MONDAY WITH MODEL TIMING
DIFFERENCES. WE NORMALLY PREFER THE SLOWER ENVELOPE OF SOLUTIONS IN
THE MIDDLE OF THE SUMMER AS THESE TYPICALLY WORK BETTER. SO POPS MAY
BE TOO AGGRESSIVE ON SUNDAY AND OPTIMISTIC FOR MONDAY. MORE 90
DEGREE DAYS ARE POSSIBLE AS PER FCST 925MB TEMPS. MONDAY IS ONE OF
THOSE DAYS WHERE WE SHOULD HIT 90 ALONG THE COASTAL PLAIN EVEN IF
THE FRONT MOVES THROUGH WITH DOWNSLOPING FLOW AS SUB 15C 850MB
TEMPS ARE STILL FORECAST TO BE JUST GETTING TO THE EASTERN GREAT
LAKES IN THE MORNING.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
THE MAIN ISSUE DURING THIS FORECAST PERIOD IS GOING TO BE THE LOW
CLOUDS DEVELOPING TONIGHT. CURRENTLY, THERE ARE A FEW SHOWERS AND
THUNDERSTORMS NEAR KRDG, BUT THEY ARE ON THE LIGHTER/LESS INTENSE
SIDE.
WITH THE ONSHORE FLOW CONTINUING THROUGH THE NIGHT. MOISTURE WILL
INCREASE AND POOL OVER THE TERMINALS, ESPECIALLY THE ONES IN
EASTERN PA. MVFR IS A REAL GOOD BET BY 07Z TONIGHT FOR ALL THE
TERMINALS. IFR LOOKS QUITE POSSIBLE FOR KRDG AND KABE BEFORE
DAYBREAK. LOOKS LIKE MORE OF A LOW CEILING ISSUE THAN VISIBILITY
ISSUE.
WINDS REMAIN OUT OF THE EAST TOMORROW, PROBABLY MORE NORTHEAST IN
THE MORNING AND MORE SOUTHEAST IN THE AFTERNOON. LOOKS LIKE A
MVFR/VFR TYPE OF DAY WITH SCATTERED SHOWERS AND THUNDERSTORMS.
OUTLOOK...
TUESDAY NIGHT...VFR...CHANCE OF MVFR CIGS AND VSBYS MAINLY NORTH.
WEDNESDAY AND WEDNESDAY NIGHT...PRIMARILY VFR, EXCEPT MVFR TO
LOCALLY IFR IN SCATTERED SHOWERS AND THUNDERSTORMS AND FOG LATE.
THURSDAY THROUGH FRIDAY NIGHT...VFR, ISOLATED MVFR CONDITIONS IN
EARLY MORNING FOG AND MORE ISOLATED (VS WEDNESDAY) SHOWERS AND
THUNDERSTORMS.
SATURDAY...PRIMARILY VFR, BUT INCREASE CHANCES OF MVFR CONDITIONS
IN GREATER COVERAGE SHOWERS AND THUNDERSTORMS.
&&
.MARINE...
FAIRLY TRANQUIL ACROSS AREA WATERS THE NEXT 24 HOURS. SOUTHEAST
WINDS TONIGHT WILL GO MORE NORTHEAST TOMORROW MORNING AND THEN
BACK TO SOUTHEAST TOMORROW IN THE AFTERNOON.
SEAS WILL BE AROUND 2 FEET ON THE OCEAN AND 1 TO 2 FEET ON THE BAY.
OUTLOOK...
WINDS AND WAVES ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THROUGH THE OUTLOOK PERIOD. WE ARE FOLLOWING THE WEAKER
OFFSHORE LOW SOLUTIONS AT THE START OF THE OUTLOOK PERIOD AS PER
PMDHMD AND A BETTER INITIALIZATION BY THE GFS (WHICH ALSO HAS WEAKER
LOWS). THUS BOTH LOWS ARE EXPECTED TO TRACK FARTHER OFFSHORE AND NOT
GENERATE ENOUGH WINDS AND SWELLS UP TO SMALL CRAFT ADVISORY CRITERIA.
BEYOND THAT, A PAIR OF COLD FRONTS ARE FORECAST TO DISSIPATE BEFORE
REACHING THE AREA WATERS ABOUT WEDNESDAY AND AGAIN ABOUT SATURDAY. A
STRONGER FRONT AS OF NOW IS FORECAST TO APPROACH BEYOND THE END OF
OUR DETERMINISTIC FORECAST PERIOD. THE PREVAILING SOUTHERLY TO
SOUTHWESTERLY FLOW IS NOT EXPECTED TO BE STRONG ENOUGH TO PRODUCE
SMALL CRAFT ADVISORY WINDS OR SWELLS INTO SATURDAY NIGHT.
&&
.TIDES/COASTAL FLOODING...
GFS ET-SURGE GUIDANCE, AND CURRENT POSITIVE 1/2 FOOT TIDAL DEPARTURES
INDICATE THE ATLC OCEAN FRONTS OF NJ/DE WOULD SEE NEAR MARGINAL
"MINOR" TIDAL INUNDATION FLOODING WITHIN 1/2 HR OF THE NEXT THREE EVENING
HIGH TIDE AS WE APPROACH FULL MOON.
&&
.RIP CURRENTS...
FOR THE REMAINDER OF THE DAY, SOUTHEAST WINDS AROUND 10 KNOTS CAN
BE EXPECTED. WAVE HEIGHTS IN THE SURF ARE FORECAST TO RANGE FROM
2 TO 3 FEET. A CONTINUED SOUTHEAST SWELL WITH AN 11 SECOND PERIOD
SHOULD RESULT IN A MODERATE RISK OF RIP CURRENTS.
&&
.CLIMATE...
IN TERMS OF 90 DEGREE DAYS FOR THE MONTH OF JULY.
AT PHILADELPHIA 21 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
HIGHER OCCURRED THROUGH THE 29TH. THIS TIES THE RECORD FOR
THE MOST NUMBER OF 90 DEGREES DAYS ALL TIME WITH 1952, 1988, 1995
AND 2011.
AT ALLENTOWN 15 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR HIGHER
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1983, 2010 AND
2011. GREATEST IS 20 DAYS IN 1999, 1966 AND 1955.
AT WILMINGTON 17 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SIXTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 1952. GREATEST
IS 22 DAYS IN 1894.
AT ATLANTIC CITY 14 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR
MORE OCCURRED THROUGH THE 29TH. THIS IS FIFTH ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY TIED WITH 2010. GREATEST IS
21 DAYS IN 1983.
AT READING 19 DAYS WITH A HIGH TEMPERATURE OF 90 DEGREES OR MORE
OCCURRED THROUGH THE 29TH. THIS IS SECOND ALL TIME IN TERMS OF DAYS
REACHING 90 DEGREES FOR THE MONTH OF JULY. GREATEST IS 20 DAYS
SET IN 2011, 2010, 1999 AND 1955.
IN TERMS OF WARMEST AVERAGE TEMPERATURE RECORDED FOR THE MONTH OF
JULY.
AT PHILADELPHIA THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH
WAS 81.9. THIS IS THE THE THIRD WARMEST JULY ON RECORD BEHIND 1994
AND 2011.
AT WILMINGTON THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH WAS
80.5. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2011 AND 1955.
AT ATLANTIC CITY THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH
WAS 78.8. THIS IS THE THIRD WARMEST JULY ON RECORD BEHIND 2010 AND
2011.
AT ALLENTOWN THE AVERAGE TEMPERATURE FOR THE MONTH THROUGH THE 29TH WAS
77.6 AND IS THE SEVENTH WARMEST JULY ON RECORD.
DATA SINCE 6/28...32 DAYS.
RDG ONLY 2 DAYS BELOW NORMAL
PHL/ABE/GED ONLY 3 DAYS BELOW NORMAL
TTN 4 DAYS BELOW NORMAL
MPO 5 DAYS BELOW NORMAL
ILG 6 DAYS BELOW NORMAL
ACY 9 DAYS BELOW NORMAL
90 OR HIGHER FOR THE SEASON
SO FAR TOTAL
NORMAL THIS YR LAST YR POR
ABE 17 24 21 1922
ACY 22 31
GED 29 40
ILG 27 27
PHL 21 30 33 1874
RDG 30 30
TTN 25 26
MPO 3 4
THE NORMAL AND PERIOD OF RECORD /POR/ IS LISTED FOR ONLY TWO CLIMATE
SITES WHERE THE DATASET IS EASILY AVAILABLE AND COMPLETE.
WITH RESPECT TO OCCURRENCES OF 95 OR GREATER
PHL CLIMATOLOGICALLY AVG`S 4/YR
SO FAR THIS YR 12
LAST YRS TOTAL 11
STATISTICALLY FOR PHL AS EVALUATED BY MARK DELISI...THE NUMBER OF 95
OR WARMER DAYS THIS YEAR IS UNUSUAL.
FOR OUR FORECAST AREA...
PCPN FOR THE MONTH SO FAR NOW GENERALLY WITHIN 75 PCT OF NORMAL.
TEMP FOR THE MONTH SO FAR NOW GENERALLY 2.5 TO 5F ABOVE NORMAL.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GIGI
NEAR TERM...KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...GIGI
AVIATION...DRAG/GIGI/KRUZDLO
MARINE...GIGI/KRUZDLO
TIDES/COASTAL FLOODING...DRAG/KRUZDLO
RIP CURRENTS...DRAG/KRUZDLO
CLIMATE...CARDINALE/DRAG/GAINES
&&
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT MON JUL 30 2012
.DISCUSSION...
310 PM CDT
SHORT TERM...THIS EVENING THROUGH THURSDAY...
PRIMARY CONCERN IS CONVECTIVE CHANCES THIS EVENING ACROSS NORTHERN
ILLINOIS. WATER VAPOR IMAGERY TODAY SHOWS STRONG MIDLEVEL RIDGING
CENTERED OVER THE SOUTHERN PLAINS AND A FAIRLY STRONG SHORTWAVE
TROUGH OVER ONTARIO...WITH ANOTHER TROUGH OFF THE PACIFIC NORTHWEST
COAST. THE TROUGH OVER ONTARIO WILL DIG SOUTHEAST...WITH ASSOCIATED
SURFACE LOW DRAGGING COOL FRONT ACROSS LAKE MICHIGAN AND ACROSS CWA
THIS EVENING THROUGH TONIGHT.
THIS EVENING...THOUGH THE BEST FORCING IN TERMS OF POSITIVE
VORTICITY ADVECTION WILL BE FOCUSED NORTHEAST OF THE CWA CLOSER TO
THE TROUGH AXIS...IT APPEARS THERE WILL BE DECENT CONVERGENCE ALONG
AND AHEAD OF THE COOL FRONT...ALONG WITH 0-6 KM BULK SHEAR VALUES
INCREASING TO 30 TO 35 KT AND NORTHERN ILLINOIS BEING IN THE EXIT
REGION OF AN ~80 KT UPPER LEVEL JET STREAK. SO THERE IS SOME SUPPORT
FOR ORGANIZED UPDRAFTS. SUSPECT THAT THE MLCAPE BEING PROGGED THIS
BY THE NAM AND RAP ACROSS FAR NORTHERN IL...IN EXCESS OF 2500 J/KG
IS A BIT OVERDONE BECAUSE FCST SURFACE TEMPS AND DEWPOINTS ARE
LIKELY A BIT TOO HIGH...BUT THERE SHOULD STILL BE AT LEAST 1500 J/KG
TO TAP INTO...WITH MINIMAL CIN. WITH TEMPERATURES ONLY SLOWLY
COOLING AHEAD OF THE FRONT...LOW LEVEL LAPSE RATES ARE EXPECTED TO
REMAIN FAIRLY STEEP AND DRY AIR IN THE LOWER LEVELS MAY SUPPORT
DCAPE VALUES IN EXCESS OF 1000 J/KG. THUS PRIMARY THREAT WITH ANY
TSRA IS EXPECTED TO BE DAMAGING WIND GUSTS...THOUGH THE GOOD DEEP
LAYER SHEAR COULD ALSO ALLOW FOR AT LEAST MARGINALLY SEVERE HAIL.
HAVE INCREASED POPS JUST A BIT ALONG AND NORTH OF I-80...THOUGH
STILL EXPECTING SCATTERED COVERAGE AT MOST...WITH EARLY EVENING
POPS CONFINED TO CLOSER TO THE WISCONSIN BORDER...SPREADING INTO
THE CHICAGO AREA LATER IN THE EVENING. DIURNAL DECREASE IN
INSTABILITY LATER THIS EVENING AND OVERNIGHT WILL LIKELY LEND TO
DECREASE IN INTENSITY AND COVERAGE OF CONVECTION. WILL MAINTAIN
LOW POPS FOR ISOLATED SHRA/TSRA AFTER MIDNIGHT AS THE FRONT PUSHES
THROUGH. KEPT THE INHERITED SLIGHT POPS TUESDAY MORNING PORTIONS
OF NORTHWEST INDIANA MAINLY EAST OF I-65...WITH THE FRONT EXPECTED
TO ON THE DOORSTEP BY THAT TIME. THE THING TO WATCH FOR WOULD BE A
SLOWER FRONTAL TIMING...WHICH MAY ALLOW SOME INSTABILITY TO
REBUILD AND PRESENT SOME OPPORTUNITY FOR THE FAR SOUTHEAST CWA TO
SEE TSRA LATE MORNING/EARLY AFTERNOON. FOR NOW...DO NOT THINK THIS
IS A LIKELY SCENARIO AND HAVE THE WHOLE CWA DRY AFTER 15Z TUESDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON TUESDAY...WITH
NORTHERLY WINDS...THOUGH THE AIR MASS REALLY WONT BE MUCH COOLER.
AREAS AWAY FROM THE LAKE SHOULD ACTUALLY REACH NEAR OR A BIT ABOVE
90 UNDER FULL SUN...WITH ONSHORE WINDS KEEPING THE LAKEFRONT IN THE
MID 80S. THE MOST NOTICEABLE DIFFERENCE BEHIND THE FRONT IS EXPECTED
TO BE A DRIER AIR MASS. THUS DESPITE ABOVE NORMAL TEMPERATURES...THE
NORTHERLY BREEZE AND MANAGEABLE HUMIDITY LEVELS WILL MAKE IT A
FAIRLY COMFORTABLE DAY...ESPECIALLY CONSIDERING ALL THE EXTREME HEAT
WEVE SEEN THIS SUMMER. WEDNESDAY WILL BE SIMILARLY WARM AND
SUNNY...EXCEPT WITH MUCH LIGHTER WINDS WITH HIGH PRESSURE OVERHEAD. IF
WINDS ARENT ONSHORE TO START TO THE DAY ALONG THE LAKEFRONT...A LAKE
BREEZE SHOULD BE ABLE TO GET GOING QUICKLY WITH SUCH LIGHT FLOW OVER
THE AREA. THIS WILL AGAIN LIMIT HIGH TEMPERATURES A BIT ALONG THE
LAKESHORE.
THURSDAY PRESENTS A MORE INTERESTING SCENARIO IN TERMS OF THE HIGH
TEMPERATURE FORECAST. THE CWA WILL NOT BE IN A FAVORED AREA WITH
REGARD TO THE POSITION OF THE CENTER OF THE MIDLEVEL RIDGE...WHICH
WILL STILL BE OVER THE SOUTHERN PLAINS. HOWEVER...AN 850 MB THERMAL
RIDGE WILL PUSH INTO THE AREA WITH WARM ADVECTION BRINGING 850 MB
TEMPS TO HIGHER THAN 20C BY THE AFTERNOON...SUCH AS ON THE WELL
PERFORMING ECMWF MODEL. WITH FULL SUN AND DEEP MIXING...THIS WOULD
SUPPORT HOT TEMPERATURES IN THE MID AND UPPER 90S. HOWEVER...BOTH
THE NAM AND ECMWF...WHICH HAVE THE HOTTEST MAX TEMPS FCST...ALSO
SUGGEST FAIRLY HIGH RH AT THE MID AND UPPER LEVELS...WHICH COULD BE
IN THE FORM OF CONVECTIVE MID AND HIGH CLOUD DEBRIS. THINK CLOUDS
WILL BE THE LIMITING FACTOR FOR TEMPS ON THURSDAY...BUT WITH THE
VERY WARM THERMAL PROFILES...RAISED TEMPS A FEW DEGREES FROM
INHERITED TO MAINLY LOW 90S. IF THERE IS LESS CLOUD
COVER...CERTAINLY COULD SEE THE HOTTER TEMPS REALIZED. ALSO...WINDS
ALOFT ARE EXPECTED TO BE WEAK ENOUGH TO ALLOW FOR A LATE DAY LAKE
BREEZE TO PUSH INLAND...WHICH MAY BRING SOME MINOR COOLING.
FORCING FOR CONVECTION LOOKS RATHER WEAK AND MAINLY THURSDAY
AFTERNOON...WITH SHORT WAVE MOVING TO NORTH AND WEAK COOL FRONT
STARTING TO DROP INTO AREA...BUT WILL MAINTAIN INHERITED SLIGHT POPS
FOR NOW FOR SHRA/TSRA. MOST OF THE AREA WILL LIKELY REMAIN DRY.
RC
LONG TERM...THURSDAY EVENING THROUGH MONDAY..
SHORT WAVE MOVING THROUGH THE NORTHERN GREAT LAKES THU EVENING WITH
ASSOCIATED WEAK SURFACE TROF/FRONT DROPPING INTO NORTHERN
IL/NORTHWEST IN. WITH BEST FORCING FURTHER NORTH AND ONLY WEAK
SURFACE CONVERGENCE...AND CONSIDERING STRENGTH OF ONGOING
DROUGHT...WILL ONLY CARRY 20-30 PCT POPS. REMNANTS OF FRONT THEN
HANG UP OVER THE AREA FRIDAY BUT AGAIN WITH ONLY WEAK LOW LEVEL
CONVERGENCE AND NO UPPER LEVEL SUPPORT...WILL JUST MAINTAIN SLIGHT
CHANCE POPS FOR FRIDAY. GFS PUSHES FRONT THROUGH AND DEVELOPS EAST
WINDS OVER THE AREA FRIDAY WHILE ECMWF HAS A WEAK WISHY WASHY
SURFACE PATTERN. EITHER WAY LAKE BREEZE LIKELY TO KEEP TEMPS IN LOW
TO MID 80S LAKEFORNT BUT NEAR 90 SOUTH TOWARDS PONTIAC.
MEANWHILE MUCH MORE POTENT TROF/UPPER LOW BARRELS INTO WESTERN
CANADA COAST WED AND PLOWS THROUGH NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THU AND FRI. THIS WILL ACT TO SHOVE UPPER RIDGE AND
ASSOCIATED HEAT DOME EASTWARD INTO THE MIDWEST AND GREAT LAKES BY
SATURDAY. SOUTHWEST FLOW AHEAD OF APPROACHING TROF PUSHES 850 TEMPS
TO AROUND 22C SATURDAY. WITH UNCERTAINTY ON CLOUD COVER HESITANT TO
RAISE TEMPS TOO MUCH. WILL GO WITH TEMPS IN LOWER 90S BUT MID TO
UPPER 90S NOT OUT OF THE QUESTION IF WE GET ENOUGH SUN. BEST CHANCE
OF WIDESPREAD RAIN IN A LONG TIME SAT AFTN AND EVENING AS STRONG
UPPER TROF/UPPER LOW MOVES THROUGH THE GREAT LAKES AND STRONG COLD
FRONT PUSHES THROUGH THE AREA. 12Z ECMWF A BITY SLOWER ON ARRIVAL OF
FRONT AND THUNDERSTORMS...MORE LIKELY SAT NIGHT INTO SUN MORNING.
TURNING COOLER AND DRIER SUN AND MON.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* SOUTHWEST WINDS PREVAILING. LAKE BREEZE APPEARS TO HAVE STOPPED
MOVING WESTWARD WITHOUT REACHING ORD OR MDW.
* POTENTIAL FOR TSRA TO IMPACT ORD AFTER 00Z.
BEACHLER
//DISCUSSION...UPDATED 18Z...
A COLD FRONT WILL BE MOVING TO THE SOUTH ACROSS MN AND WI
TONIGHT...AND WILL MOVE THROUGH NORTHERN IL AND NORTHWEST IN
TUESDAY MORNING. TSRA WILL DEVELOP NEAR AND AHEAD OF THE FRONT
OVER WI THIS AFTERNOON. TSRA ARE EXPECTED TO STAY TO THE NORTH OF
THE TERMINALS...THOUGH THEY COULD GET CLOSE TO ORD AND RFD AFTER
00Z. THE CHANCES OF TSRA ACTUALLY GETTING TO THE TERMINALS IS TOO
LOW TO BE INCLUDED IN THE TAFS AT THIS TIME.
WHEN THE COLD FRONT MOVES THROUGH ON TUESDAY MORNING WINDS WILL
SHIFT FIRST TO THE WEST AND THEN TO THE NORTHWEST. THE CHICAGO
AREA TERMINALS WILL THEN SHIFT TO THE NORTHEAST IN THE AFTERNOON.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN LAKE BREEZE NOT AFFECTING ORD OR MDW.
* LOW CONFIDENCE IN POTENTIAL FOR TSRA TO REACH ORD.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR.
THURSDAY AND FRIDAY...VFR. SLIGHT CHANCE TSRA/SHRA WITH
OCCASIONAL MVFR CIGS.
SATURDAY...CHANCE OF TSRA/SHRA WITH OCCASIONAL MVFR CIGS.
SUNDAY...VFR.
JEE
&&
.MARINE...
226 PM CDT
LOW PRESSURE MOVING ACROSS SOUTHERN ONTARIO...WILL DRAG A COLD FRONT
DOWN THE LAKE TONIGHT. SOME STRONG TO SEVERE THUNDERSTORMS COULD
OCCUR ACROSS THE LAKE THIS EVENING AHEAD OF THE FRONT. ONCE THE
FRONT PASSES THE WINDS WILL SWITCH OUT OF THE NORTH UP TO 25 KT.
THESE STRONGER WINDS WILL CONTINUE ACROSS THE SOUTH HALF OF THE LAKE
DURING THE DAY ON TUESDAY. WAVES OVER 4 FEET ARE POSSIBLE ALONG THE
INDIANA NEAR SHORE WATERS. THIS COULD RESULT IN HAZARDS TO SMALL
CRAFT FOR TUESDAY EVENING THROUGH WEDNESDAY MORNING. HIGH PRESSURE
WILL BUILD IN ACROSS THE LAKE TUESDAY NIGHT INTO WEDNESDAY. THIS
WILL RESULT IN ABATING WINDS FOR A PERIOD TUESDAY NIGHT INTO
WEDNESDAY.
THE WINDS LOOK TO TURN SOUTHERLY AT 10 TO 20 KT AGAIN BY THURSDAY AS
THE SURFACE HIGH SHIFTS EASTWARD ACROSS THE OHIO VALLEY. ANOTHER
AREA OF LOW PRESSURE MAY PUSH ANOTHER COLD FRONT ACROSS THE LAKE
LATE THURSDAY AND THURSDAY NIGHT...BRINGING ANOTHER PUSH OF NORTHERLY
FLOW DOWN THE LAKE. IN THE EXTENDED PERIOD IT APPEARS THAT A
STRONGER STORM SYSTEM MAY MOVE ACROSS THE UPPER MIDWEST AND GREAT
LAKES REGION OVER THE WEEKEND. THIS COULD PRODUCE A PERIOD OF
STRONGER WINDS ACROSS THE LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...HIGH RIP CURRENT RISK...ILZ014...10 AM TUESDAY TO 10 AM
WEDNESDAY.
IN...HIGH RIP CURRENT RISK...INZ001-INZ002...10 AM TUESDAY TO 10 AM
WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ742-LMZ743-LMZ744-LMZ745...4 PM
TUESDAY TO 10 AM WEDNESDAY.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
315 PM CDT MON JUL 30 2012
.DISCUSSION...
310 PM CDT
SHORT TERM...THIS EVENING THROUGH THURSDAY...
PRIMARY CONCERN IS CONVECTIVE CHANCES THIS EVENING ACROSS NORTHERN
ILLINOIS. WATER VAPOR IMAGERY TODAY SHOWS STRONG MIDLEVEL RIDGING
CENTERED OVER THE SOUTHERN PLAINS AND A FAIRLY STRONG SHORTWAVE
TROUGH OVER ONTARIO...WITH ANOTHER TROUGH OFF THE PACIFIC NORTHWEST
COAST. THE TROUGH OVER ONTARIO WILL DIG SOUTHEAST...WITH ASSOCIATED
SURFACE LOW DRAGGING COOL FRONT ACROSS LAKE MICHIGAN AND ACROSS CWA
THIS EVENING THROUGH TONIGHT.
THIS EVENING...THOUGH THE BEST FORCING IN TERMS OF POSITIVE
VORTICITY ADVECTION WILL BE FOCUSED NORTHEAST OF THE CWA CLOSER TO
THE TROUGH AXIS...IT APPEARS THERE WILL BE DECENT CONVERGENCE ALONG
AND AHEAD OF THE COOL FRONT...ALONG WITH 0-6 KM BULK SHEAR VALUES
INCREASING TO 30 TO 35 KT AND NORTHERN ILLINOIS BEING IN THE EXIT
REGION OF AN ~80 KT UPPER LEVEL JET STREAK. SO THERE IS SOME SUPPORT
FOR ORGANIZED UPDRAFTS. SUSPECT THAT THE MLCAPE BEING PROGGED THIS
BY THE NAM AND RAP ACROSS FAR NORTHERN IL...IN EXCESS OF 2500 J/KG
IS A BIT OVERDONE BECAUSE FCST SURFACE TEMPS AND DEWPOINTS ARE
LIKELY A BIT TOO HIGH...BUT THERE SHOULD STILL BE AT LEAST 1500 J/KG
TO TAP INTO...WITH MINIMAL CIN. WITH TEMPERATURES ONLY SLOWLY
COOLING AHEAD OF THE FRONT...LOW LEVEL LAPSE RATES ARE EXPECTED TO
REMAIN FAIRLY STEEP AND DRY AIR IN THE LOWER LEVELS MAY SUPPORT
DCAPE VALUES IN EXCESS OF 1000 J/KG. THUS PRIMARY THREAT WITH ANY
TSRA IS EXPECTED TO BE DAMAGING WIND GUSTS...THOUGH THE GOOD DEEP
LAYER SHEAR COULD ALSO ALLOW FOR AT LEAST MARGINALLY SEVERE HAIL.
HAVE INCREASED POPS JUST A BIT ALONG AND NORTH OF I-80...THOUGH
STILL EXPECTING SCATTERED COVERAGE AT MOST...WITH EARLY EVENING
POPS CONFINED TO CLOSER TO THE WISCONSIN BORDER...SPREADING INTO
THE CHICAGO AREA LATER IN THE EVENING. DIURNAL DECREASE IN
INSTABILITY LATER THIS EVENING AND OVERNIGHT WILL LIKELY LEND TO
DECREASE IN INTENSITY AND COVERAGE OF CONVECTION. WILL MAINTAIN
LOW POPS FOR ISOLATED SHRA/TSRA AFTER MIDNIGHT AS THE FRONT PUSHES
THROUGH. KEPT THE INHERITED SLIGHT POPS TUESDAY MORNING PORTIONS
OF NORTHWEST INDIANA MAINLY EAST OF I-65...WITH THE FRONT EXPECTED
TO ON THE DOORSTEP BY THAT TIME. THE THING TO WATCH FOR WOULD BE A
SLOWER FRONTAL TIMING...WHICH MAY ALLOW SOME INSTABILITY TO
REBUILD AND PRESENT SOME OPPORTUNITY FOR THE FAR SOUTHEAST CWA TO
SEE TSRA LATE MORNING/EARLY AFTERNOON. FOR NOW...DO NOT THINK THIS
IS A LIKELY SCENARIO AND HAVE THE WHOLE CWA DRY AFTER 15Z TUESDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT ON TUESDAY...WITH
NORTHERLY WINDS...THOUGH THE AIR MASS REALLY WONT BE MUCH COOLER.
AREAS AWAY FROM THE LAKE SHOULD ACTUALLY REACH NEAR OR A BIT ABOVE
90 UNDER FULL SUN...WITH ONSHORE WINDS KEEPING THE LAKEFRONT IN THE
MID 80S. THE MOST NOTICEABLE DIFFERENCE BEHIND THE FRONT IS EXPECTED
TO BE A DRIER AIR MASS. THUS DESPITE ABOVE NORMAL TEMPERATURES...THE
NORTHERLY BREEZE AND MANAGEABLE HUMIDITY LEVELS WILL MAKE IT A
FAIRLY COMFORTABLE DAY...ESPECIALLY CONSIDERING ALL THE EXTREME HEAT
WEVE SEEN THIS SUMMER. WEDNESDAY WILL BE SIMILARLY WARM AND
SUNNY...EXCEPT WITH MUCH LIGHTER WINDS WITH HIGH PRESSURE OVERHEAD. IF
WINDS ARENT ONSHORE TO START TO THE DAY ALONG THE LAKEFRONT...A LAKE
BREEZE SHOULD BE ABLE TO GET GOING QUICKLY WITH SUCH LIGHT FLOW OVER
THE AREA. THIS WILL AGAIN LIMIT HIGH TEMPERATURES A BIT ALONG THE
LAKESHORE.
THURSDAY PRESENTS A MORE INTERESTING SCENARIO IN TERMS OF THE HIGH
TEMPERATURE FORECAST. THE CWA WILL NOT BE IN A FAVORED AREA WITH
REGARD TO THE POSITION OF THE CENTER OF THE MIDLEVEL RIDGE...WHICH
WILL STILL BE OVER THE SOUTHERN PLAINS. HOWEVER...AN 850 MB THERMAL
RIDGE WILL PUSH INTO THE AREA WITH WARM ADVECTION BRINGING 850 MB
TEMPS TO HIGHER THAN 20C BY THE AFTERNOON...SUCH AS ON THE WELL
PERFORMING ECMWF MODEL. WITH FULL SUN AND DEEP MIXING...THIS WOULD
SUPPORT HOT TEMPERATURES IN THE MID AND UPPER 90S. HOWEVER...BOTH
THE NAM AND ECMWF...WHICH HAVE THE HOTTEST MAX TEMPS FCST...ALSO
SUGGEST FAIRLY HIGH RH AT THE MID AND UPPER LEVELS...WHICH COULD BE
IN THE FORM OF CONVECTIVE MID AND HIGH CLOUD DEBRIS. THINK CLOUDS
WILL BE THE LIMITING FACTOR FOR TEMPS ON THURSDAY...BUT WITH THE
VERY WARM THERMAL PROFILES...RAISED TEMPS A FEW DEGREES FROM
INHERITED TO MAINLY LOW 90S. IF THERE IS LESS CLOUD
COVER...CERTAINLY COULD SEE THE HOTTER TEMPS REALIZED. ALSO...WINDS
ALOFT ARE EXPECTED TO BE WEAK ENOUGH TO ALLOW FOR A LATE DAY LAKE
BREEZE TO PUSH INLAND...WHICH MAY BRING SOME MINOR COOLING.
FORCING FOR CONVECTION LOOKS RATHER WEAK AND MAINLY THURSDAY
AFTERNOON...WITH SHORT WAVE MOVING TO NORTH AND WEAK COOL FRONT
STARTING TO DROP INTO AREA...BUT WILL MAINTAIN INHERITED SLIGHT POPS
FOR NOW FOR SHRA/TSRA. MOST OF THE AREA WILL LIKELY REMAIN DRY.
RC
LONG TERM...THURSDAY EVENING THROUGH MONDAY..
SHORT WAVE MOVING THROUGH THE NORTHERN GREAT LAKES THU EVENING WITH
ASSOCIATED WEAK SURFACE TROF/FRONT DROPPING INTO NORTHERN
IL/NORTHWEST IN. WITH BEST FORCING FURTHER NORTH AND ONLY WEAK
SURFACE CONVERGENCE...AND CONSIDERING STRENGTH OF ONGOING
DROUGHT...WILL ONLY CARRY 20-30 PCT POPS. REMNANTS OF FRONT THEN
HANG UP OVER THE AREA FRIDAY BUT AGAIN WITH ONLY WEAK LOW LEVEL
CONVERGENCE AND NO UPPER LEVEL SUPPORT...WILL JUST MAINTAIN SLIGHT
CHANCE POPS FOR FRIDAY. GFS PUSHES FRONT THROUGH AND DEVELOPS EAST
WINDS OVER THE AREA FRIDAY WHILE ECMWF HAS A WEAK WISHY WASHY
SURFACE PATTERN. EITHER WAY LAKE BREEZE LIKELY TO KEEP TEMPS IN LOW
TO MID 80S LAKEFORNT BUT NEAR 90 SOUTH TOWARDS PONTIAC.
MEANWHILE MUCH MORE POTENT TROF/UPPER LOW BARRELS INTO WESTERN
CANADA COAST WED AND PLOWS THROUGH NORTHERN ROCKIES AND INTO THE
NORTHERN PLAINS THU AND FRI. THIS WILL ACT TO SHOVE UPPER RIDGE AND
ASSOCIATED HEAT DOME EASTWARD INTO THE MIDWEST AND GREAT LAKES BY
SATURDAY. SOUTHWEST FLOW AHEAD OF APPROACHING TROF PUSHES 850 TEMPS
TO AROUND 22C SATURDAY. WITH UNCERTAINTY ON CLOUD COVER HESITANT TO
RAISE TEMPS TOO MUCH. WILL GO WITH TEMPS IN LOWER 90S BUT MID TO
UPPER 90S NOT OUT OF THE QUESTION IF WE GET ENOUGH SUN. BEST CHANCE
OF WIDESPREAD RAIN IN A LONG TIME SAT AFTN AND EVENING AS STRONG
UPPER TROF/UPPER LOW MOVES THROUGH THE GREAT LAKES AND STRONG COLD
FRONT PUSHES THROUGH THE AREA. 12Z ECMWF A BITY SLOWER ON ARRIVAL OF
FRONT AND THUNDERSTORMS...MORE LIKELY SAT NIGHT INTO SUN MORNING.
TURNING COOLER AND DRIER SUN AND MON.
ALLSOPP
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SOUTH TO SOUTHWEST WINDS PREVAILING. LAKE BREEZE APPEARS TO HAVE
STOPPED MOVING WESTWARD WITHOUT REACHING ORD OR MDW.
* POTENTIAL FOR TSRA TO IMPACT ORD AFTER 00Z.
PAW
//DISCUSSION...UPDATED 18Z...
A COLD FRONT WILL BE MOVING TO THE SOUTH ACROSS MN AND WI
TONIGHT...AND WILL MOVE THROUGH NORTHERN IL AND NORTHWEST IN
TUESDAY MORNING. TSRA WILL DEVELOP NEAR AND AHEAD OF THE FRONT
OVER WI THIS AFTERNOON. TSRA ARE EXPECTED TO STAY TO THE NORTH OF
THE TERMINALS...THOUGH THEY COULD GET CLOSE TO ORD AND RFD AFTER
00Z. THE CHANCES OF TSRA ACTUALLY GETTING TO THE TERMINALS IS TOO
LOW TO BE INCLUDED IN THE TAFS AT THIS TIME.
WHEN THE COLD FRONT MOVES THROUGH ON TUESDAY MORNING WINDS WILL
SHIFT FIRST TO THE WEST AND THEN TO THE NORTHWEST. THE CHICAGO
AREA TERMINALS WILL THEN SHIFT TO THE NORTHEAST IN THE AFTERNOON.
PAW
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE IN LAKE BREEZE NOT AFFECTING ORD OR MDW.
* LOW CONFIDENCE IN POTENTIAL FOR TSRA TO REACH ORD.
PAW
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR.
THURSDAY AND FRIDAY...VFR. SLIGHT CHANCE TSRA/SHRA WITH
OCCASIONAL MVFR CIGS.
SATURDAY...CHANCE OF TSRA/SHRA WITH OCCASIONAL MVFR CIGS.
SUNDAY...VFR.
JEE
&&
.MARINE...
226 PM CDT
LOW PRESSURE MOVING ACROSS SOUTHERN ONTARIO...WILL DRAG A COLD FRONT
DOWN THE LAKE TONIGHT. SOME STRONG TO SEVERE THUNDERSTORMS COULD
OCCUR ACROSS THE LAKE THIS EVENING AHEAD OF THE FRONT. ONCE THE
FRONT PASSES THE WINDS WILL SWITCH OUT OF THE NORTH UP TO 25 KT.
THESE STRONGER WINDS WILL CONTINUE ACROSS THE SOUTH HALF OF THE LAKE
DURING THE DAY ON TUESDAY. WAVES OVER 4 FEET ARE POSSIBLE ALONG THE
INDIANA NEAR SHORE WATERS. THIS COULD RESULT IN HAZARDS TO SMALL
CRAFT FOR TUESDAY EVENING THROUGH WEDNESDAY MORNING. HIGH PRESSURE
WILL BUILD IN ACROSS THE LAKE TUESDAY NIGHT INTO WEDNESDAY. THIS
WILL RESULT IN ABATING WINDS FOR A PERIOD TUESDAY NIGHT INTO
WEDNESDAY.
THE WINDS LOOK TO TURN SOUTHERLY AT 10 TO 20 KT AGAIN BY THURSDAY AS
THE SURFACE HIGH SHIFTS EASTWARD ACROSS THE OHIO VALLEY. ANOTHER
AREA OF LOW PRESSURE MAY PUSH ANOTHER COLD FRONT ACROSS THE LAKE
LATE THURSDAY AND THURSDAY NIGHT...BRINGING ANOTHER PUSH OF NORTHERLY
FLOW DOWN THE LAKE. IN THE EXTENDED PERIOD IT APPEARS THAT A
STRONGER STORM SYSTEM MAY MOVE ACROSS THE UPPER MIDWEST AND GREAT
LAKES REGION OVER THE WEEKEND. THIS COULD PRODUCE A PERIOD OF
STRONGER WINDS ACROSS THE LAKE.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1222 PM CDT MON JUL 30 2012
.AVIATION...
VFR WX IS EXPECTED THROUGH 06Z/31. THERE IS STILL UNCERTAINTY
REGARDING THE POTENTIAL FOR DIURNAL CONVECTION IN THE 23Z/30 TO
03Z/31 TIME FRAME. IF DIURNAL CONVECTION WOULD DVLP IT WOULD BE
ISOLD IN NATURE AND KDBQ WOULD HAVE THE BEST CHANCE IF ANY FOR A
POSSIBLE SHRA/TSRA. AREAL COVERAGE LIKELY WILL BE 10 PERCENT OR
LESS SO NO VCSH/VCTS WAS INCLUDED IN THE 18Z TAF FOR KDBQ. AFT
06Z/31 CONTINUED LIGHT WINDS MAY ALLOW MVFR FG TO DVLP ARND
SUNRISE BUT WAS NOT INCLUDED IN THE 18Z TAFS. ..08..
&&
.PREV DISCUSSION... /ISSUED 1106 AM CDT MON JUL 30 2012/
UPDATE...
AN UPDATE TO THE FCST HAS BEEN DONE TO REFLECT CURRENT TRENDS.
RAIN FROM THE DECAYING MISSOURI MCS WILL REMAIN JUST SOUTH OF THE
CWFA LATE THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. CLOUD
COVER FROM THE MCS WILL HELP SUPPRESS TEMPERATURES A COUPLE OF
DEGREES IN THE FAR SOUTH. SATELLITE TRENDS DO SHOW THE CLOUD
COVER IS SLOWLY THINNING WITH TIME.
LIGHT WINDS ACROSS THE AREA IS ALLOWING DEW POINTS TO CLIMB HIGHER
THAN PREVIOUSLY THOUGHT. HOWEVER...BASED ON PROJECTED MAX
TEMPERATURES AND DEW POINTS THE HEAT INDEX READINGS SHOULD ONLY
REACH THE MID 90S WITH PERHAPS SOME LOCALIZED UPPER 90S.
CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON AND EVENING ACROSS THE
CWFA IS STILL UNCERTAIN. CONVECTIVE TEMPERATURES ON THE 12Z
SOUNDINGS RANGED FROM THE LOW 80S TO THE LOW 90S. RAP TRENDS
INDICATE CONVECTIVE TEMPERATURES WILL CLIMB INTO THE MID AND UPPER
90S ACROSS THE CWFA DURING THE AFTERNOON HOURS. THUS CONVECTION
THIS AFTERNOON APPEARS DOUBTFUL.
THE QUESTION THEN BECOMES WILL THE WEAK FRONT BE STRONG ENOUGH TO
INITIATE CONVECTION LATE THIS AFTERNOON AND EARLY EVENING AS THE
ATMOSPHERE COOLS. THE BETTER FORCING IS NORTHEAST OF THE CWFA AS
IS THE BETTER DIFFLUENCE ALOFT. FOR NOW WILL CONTINUE WITH THE
CURRENT SCHC/LOW CHC POPS IN THE NORTH/NORTHEAST CWFA FOR THE
EVENING HOURS. HOWEVER...THE PROBABILITY OF SOMETHING HAPPENING
IS NOT HIGH. ..08..
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1106 AM CDT MON JUL 30 2012
.UPDATE...
AN UPDATE TO THE FCST HAS BEEN DONE TO REFLECT CURRENT TRENDS.
RAIN FROM THE DECAYING MISSOURI MCS WILL REMAIN JUST SOUTH OF THE
CWFA LATE THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. CLOUD
COVER FROM THE MCS WILL HELP SUPPRESS TEMPERATURES A COUPLE OF
DEGREES IN THE FAR SOUTH. SATELLITE TRENDS DO SHOW THE CLOUD
COVER IS SLOWLY THINNING WITH TIME.
LIGHT WINDS ACROSS THE AREA IS ALLOWING DEW POINTS TO CLIMB HIGHER
THAN PREVIOUSLY THOUGHT. HOWEVER...BASED ON PROJECTED MAX
TEMPERATURES AND DEW POINTS THE HEAT INDEX READINGS SHOULD ONLY
REACH THE MID 90S WITH PERHAPS SOME LOCALIZED UPPER 90S.
CONVECTIVE DEVELOPMENT LATE THIS AFTERNOON AND EVENING ACROSS THE
CWFA IS STILL UNCERTAIN. CONVECTIVE TEMPERATURES ON THE 12Z
SOUNDINGS RANGED FROM THE LOW 80S TO THE LOW 90S. RAP TRENDS
INDICATE CONVECTIVE TEMPERATURES WILL CLIMB INTO THE MID AND UPPER
90S ACROSS THE CWFA DURING THE AFTERNOON HOURS. THUS CONVECTION
THIS AFTERNOON APPEARS DOUBTFUL.
THE QUESTION THEN BECOMES WILL THE WEAK FRONT BE STRONG ENOUGH TO
INITIATE CONVECTION LATE THIS AFTERNOON AND EARLY EVENING AS THE
ATMOSPHERE COOLS. THE BETTER FORCING IS NORTHEAST OF THE CWFA AS
IS THE BETTER DIFFLUENCE ALOFT. FOR NOW WILL CONTINUE WITH THE
CURRENT SCHC/LOW CHC POPS IN THE NORTH/NORTHEAST CWFA FOR THE
EVENING HOURS. HOWEVER...THE PROBABILITY OF SOMETHING HAPPENING
IS NOT HIGH. ..08..
&&
.PREV DISCUSSION... /ISSUED 700 AM CDT MON JUL 30 2012/
UPDATE...
WEAKENING MCS HAS MOVED INTO NORTHWEST MO AND WAS SPREADING A
CIRRUS SHIELD INTO PORTIONS OF EASTERN IA...WESTERN IL AND
NORTHEAST MO. OTHERWISE COLD FRONT EXTENDED FROM NORTHERN MN TO
NORTHERN SD AND WAS MOVING SOUTHEAST. EXPECT AS THE MCS CONTINUES
TO WEAKEN THE CIRRUS WILL THIN ALLOWING FOR HEATING TO TAKE PLACE
AHEAD OF THE ADVANCING COLD FRONT. GRIDS UNCHANGED AT THIS TIME.
AVIATION...
VFR CONDS TODAY AND TONIGHT. THERE WILL BE ISOLATED TO SCATTERED
THUNDERSTORMS DEVELOPING ALONG A COLD FRONT LATE THIS AFTERNOON
AND EVENING. WILL CARRY VCTS AT KCID/KDBQ/KMLI LEAVING IT OUT OF
KBRL FOR NOW. SOUTHEAST WINDS LESS THAN 10 KNOTS TODAY BECOMING
NORTHWEST BEHIND THE FRONT TONIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
351 PM CDT MON JUL 30 2012
...UPDATED FOR LONG TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1158 AM CDT MON JUL 30 2012
AN UPPER LEVEL HIGH CONTINUED TO GRIP THE CENTRAL AND SOUTHERN GREAT
PLAINS. THE CENTER OF THE HIGH AT 500MB WAS LOCATED ACROSS THE
SOUTHERN TEXAS PANHANDLE PER RAOB AND RAP ANALYSIS AS OF 30.12Z. AN
ARC OF MID LEVEL MOISTURE COULD BE SEEN ON WATER VAPOR LOOP AND RAOB
ANALYSIS FROM WESTERN/CENTRAL ARIZONA THROUGH UTAH AND NORTHEAST TO
SOUTHEASTERN WYOMING AND WESTERN NEBRASKA. ALL ALONG THIS MOISTURE
ARC...THERE WERE MINOR MID LEVEL PERTURBATIONS IN THE FLOW PATTERN
DUE TO LATENT HEAT RELEASE FROM VARIOUS THUNDERSTORM CLUSTERS. A
MESOSCALE CONVECTIVE SYSTEM MOVED ACROSS SOUTHERN NEBRASKA/NORTHERN
KANSAS DURING THE OVERNIGHT HOURS WITH THE MID LEVEL POTENTIAL
VORTICITY ANOMALY TIED TO THIS MCS MOVING INTO EASTERN KS/WESTERN
MO. ADDITIONAL MID LEVEL VORTICITY COULD BE SEEN IN THE RAP ANALYSIS
MOVING INTO NORTHERN COLORADO WITH A 30-40 KNOT 400MB SPEED MAX
ROTATING NORTH-NORTHEASTWARD INTO THE COLORADO ROCKIES. IN THE LOWER
TROPOSPHERE...A STATIONARY FRONT EXTENDED FROM ROUGHLY BEAVER, OK TO
BUCKLIN, KS TO NEAR PRATT, KS AT 16Z. OKLAHOMA MESONET OBSERVATIONS
AT 1650Z REVEALED AN AXIS OF 102 TO 104F TEMPERATURES ACROSS
WEST-CENTRAL OKLAHOMA ON WEST-SOUTHWEST SURFACE WINDS SOUTH OF THIS
BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 244 PM CDT MON JUL 30 2012
WITH THE AFTERNOON FORECAST UPDATE...WILL LOWER THE POPS DOWN TO
10-14 PERCENT FOR AREAS ALONG THE STATIONARY FRONT AS CONVERGENCE
ALONG THE FRONT IS QUITE WEAK AND THERE HAS BEEN A LACK OF CUMULUS
DEVELOPMENT THROUGH 1930Z. IF ANYTHING DOES DEVELOP...THE COVERAGE
WILL BE VERY ISOLATED AND ANY INDIVIDUAL STORM WILL BE SMALL. WILL
BE TURNING THE ATTENTION TO THE WEST LATER ON THIS EVENING AND
DURING THE OVERNIGHT HOURS AS AN MCS MAY DEVELOP IN THE POST-FRONTAL
LIGHT UPSLOPE WINDS WITH DEWPOINTS IN THE MID TO UPPER 50S ACROSS
EAST-CENTRAL COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS ALONG AND
NORTH OF THE FRONT. VARIOUS HIGH-RESOLUTION CONVECTION-ALLOWING
MODELS SUGGEST HIGHER TERRAIN STORMS WILL MANAGE TO HOLD TOGETHER TO
THE KANSAS STATE BORDER...SO WILL HAVE 30 POPS GOING ACROSS THE
WESTERN COUNTIES AND 20 POPS AS FAR EAST AS ROUGHLY HIGHWAY 83.
LATE TONIGHT INTO TOMORROW...THE CONVECTIVE OUTFLOW FROM WHATEVER
REMAINS OF THE MCS TONIGHT WILL PUSH THE STATIONARY FRONT FARTHER
SOUTH THAN WHERE IT IS NOW WITH A WEAK WAVE DEVELOPING ALONG THE
FRONT ACROSS SOUTH-CENTRAL KS BY DAYBREAK TUESDAY. WEST OF THE
WAVE...WINDS AT THE SURFACE WILL LIKELY BE MORE NORTHERLY ACROSS
MUCH OF THE DDC FORECAST AREA. TOMORROW`S FORECAST HIGH TEMPERATURE
HAS BEEN LOWERED TO MID-UPPER 90S FROM HAYS TO CIMARRON TO HUGOTON
AND POINTS WEST TO THE COLORADO BORDER. EVEN THE AREAS ACROSS SOUTH
CENTRAL KANSAS WILL BE SLIGHTLY NORTH OF THE FRONT MORE THAN LIKELY
AND HAVE LOWERED THE HIGHS IN MEDICINE LODGE AREA DOWN TO ABOUT
103-104F (WHICH MAY STILL BE A BIT TOO WARM IF THE FRONT ENDS UP
BEING JUST SOUTH OF THERE). AS FAR AS THUNDERSTORM POTENTIAL GOES
TOMORROW...IT WILL BE VERY SIMILAR TO TODAY...WITH THE GENERAL
THINKING BEING THAT ANYTHING THAT WOULD DEVELOP ALONG THE FRONT
WOULD BE VERY ISOLATED IN NATURE WITH THE MOST COHERENT CONVECTION
FORMING ONCE AGAIN OVER EASTERN COLORADO. WILL BE KEEPING POPS BELOW
15 EXCEPT NEAR THE COLORADO BORDER FOR LATE IN THE AFTERNOON TUESDAY
AS A RESULT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 336 PM CDT MON JUL 30 2012
AN UPPER LEVEL RIDGE WILL REMAIN ACROSS THE SOUTHERN PLAINS
WEDNESDAY AND THURSDAY, WITH WESTERN KANSAS LOCATED ALONG THE
SOUTHERN EDGE OF THE WESTERLIES NEAR A QUASI-STATIONARY SURFACE
FRONT. ORDINARILY THIS KIND OF PATTERN COULD RESULT IN ISOLATED
THUNDERSTORMS. BUT THIS YEAR THE LOW-LEVEL MOISTURE IS JUST VERY
LIMITED. NEVERTHELESS, ISOLATED THUNDERSTORMS CANNOT BE RULED OUT
EITHER DAY. TEMPERATURES WILL CONTINUE TO BE HOT, ESPECIALLY
SOUTH OF THE FRONT OVER SOUTH CENTRAL AND PARTS OF SOUTHWEST
KANSAS TO THE SOUTH OF THE FRONT.
ALTHOUGH THERE ARE SLIGHT DIFFERENCES IN MODEL TIMING, A STRONG
SHORTWAVE TROUGH IS ADVERTISED TO DIG INTO THE NORTHERN ROCKIES
FRIDAY AND THEN PASS ACROSS THE NORTHERN PLAINS BY SATURDAY.
AN OLD FRONT WILL STILL BE STALLED OUT ACROSS SOUTHWEST KANSAS, AND
A REINFORCING COLD FRONT WILL APPROACH KANSAS WITH THE NORTHERN
STREAM SYSTEM BY SATURDAY OR SATURDAY NIGHT. THERE WILL BE ADDITIONAL
SMALL CHANCES FOR THUNDERSTORMS EACH DAY, WITH THE EXACT LOCATION
DEPENDING ON WHERE THE FRONTAL BOUNDARIES ARE. IT WILL STILL BE HOT,
ESPECIALLY SOUTH OF THE FRONTS OVER SOUTH CENTRAL KANSAS, WITH HIGHS
ABOVE 105F FOR BOTH FRIDAY AND SATURDAY. SLIGHTLY COOLER TEMPERATURES
CAN BE EXPECTED IN WEST CENTRAL KANSAS. SLIGHTLY COOLER
TEMPERATURES ARE EXPECTED BY SUNDAY AND MONDAY ACROSS MOST OF
SOUTHWEST KANSAS AFTER THE AFOREMENTIONED SHORTWAVE TROUGH PUSHES
A COLD FRONT THROUGH KANSAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1158 AM CDT MON JUL 30 2012
A WEAK STATIONARY FRONT WILL PERSIST ACROSS SOUTHWEST KANSAS THROUGH
TODAY AND TONIGHT. WHILE AN ISOLATED THUNDERSTORM MAY DEVELOP LATE
IN THE AFTERNOON/EVENING ANYWHERE ALONG THIS BOUNDARY...THE COVERAGE
IS NOT EXPECTED TO BE ENOUGH TO JUSTIFY INCLUSION IN THE TAFS. WILL
HOWEVER INCLUDE A PROB30 GROUP FOR THUNDERSTORMS AT GCK DURING THE
OVERNIGHT HOURS AS THERE IS A GREATER PROBABILITY OF A SMALL CLUSTER
OF STORMS TO MOVE EAST OUT OF EASTERN COLORADO AND PERHAPS AFFECT
GCK ALONG/NORTH OF THE MENTIONED STATIONARY FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 100 75 104 / 10 10 20 10
GCK 71 96 73 103 / 20 10 20 20
EHA 70 98 73 103 / 30 20 20 20
LBL 71 99 74 104 / 20 10 20 10
HYS 71 98 75 103 / 10 10 20 10
P28 75 104 78 108 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...FINCH
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
246 PM CDT MON JUL 30 2012
...UPDATED SHORT TERM SECTION...
.SYNOPSIS...
ISSUED AT 1158 AM CDT MON JUL 30 2012
AN UPPER LEVEL HIGH CONTINUED TO GRIP THE CENTRAL AND SOUTHERN GREAT
PLAINS. THE CENTER OF THE HIGH AT 500MB WAS LOCATED ACROSS THE
SOUTHERN TEXAS PANHANDLE PER RAOB AND RAP ANALYSIS AS OF 30.12Z. AN
ARC OF MID LEVEL MOISTURE COULD BE SEEN ON WATER VAPOR LOOP AND RAOB
ANALYSIS FROM WESTERN/CENTRAL ARIZONA THROUGH UTAH AND NORTHEAST TO
SOUTHEASTERN WYOMING AND WESTERN NEBRASKA. ALL ALONG THIS MOISTURE
ARC...THERE WERE MINOR MID LEVEL PERTURBATIONS IN THE FLOW PATTERN
DUE TO LATENT HEAT RELEASE FROM VARIOUS THUNDERSTORM CLUSTERS. A
MESOSCALE CONVECTIVE SYSTEM MOVED ACROSS SOUTHERN NEBRASKA/NORTHERN
KANSAS DURING THE OVERNIGHT HOURS WITH THE MID LEVEL POTENTIAL
VORTICITY ANOMALY TIED TO THIS MCS MOVING INTO EASTERN KS/WESTERN
MO. ADDITIONAL MID LEVEL VORTICITY COULD BE SEEN IN THE RAP ANALYSIS
MOVING INTO NORTHERN COLORADO WITH A 30-40 KNOT 400MB SPEED MAX
ROTATING NORTH-NORTHEASTWARD INTO THE COLORADO ROCKIES. IN THE LOWER
TROPOSPHERE...A STATIONARY FRONT EXTENDED FROM ROUGHLY BEAVER, OK TO
BUCKLIN, KS TO NEAR PRATT, KS AT 16Z. OKLAHOMA MESONET OBSERVATIONS
AT 1650Z REVEALED AN AXIS OF 102 TO 104F TEMPERATURES ACROSS
WEST-CENTRAL OKLAHOMA ON WEST-SOUTHWEST SURFACE WINDS SOUTH OF THIS
BOUNDARY.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 244 PM CDT MON JUL 30 2012
WITH THE AFTERNOON FORECAST UPDATE...WILL LOWER THE POPS DOWN TO
10-14 PERCENT FOR AREAS ALONG THE STATIONARY FRONT AS CONVERGENCE
ALONG THE FRONT IS QUITE WEAK AND THERE HAS BEEN A LACK OF CUMULUS
DEVELOPMENT THROUGH 1930Z. IF ANYTHING DOES DEVELOP...THE COVERAGE
WILL BE VERY ISOLATED AND ANY INDIVIDUAL STORM WILL BE SMALL. WILL
BE TURNING THE ATTENTION TO THE WEST LATER ON THIS EVENING AND
DURING THE OVERNIGHT HOURS AS AN MCS MAY DEVELOP IN THE POST-FRONTAL
LIGHT UPSLOPE WINDS WITH DEWPOINTS IN THE MID TO UPPER 50S ACROSS
EAST-CENTRAL COLORADO AND WEST-CENTRAL/SOUTHWEST KANSAS ALONG AND
NORTH OF THE FRONT. VARIOUS HIGH-RESOLUTION CONVECTION-ALLOWING
MODELS SUGGEST HIGHER TERRAIN STORMS WILL MANAGE TO HOLD TOGETHER TO
THE KANSAS STATE BORDER...SO WILL HAVE 30 POPS GOING ACROSS THE
WESTERN COUNTIES AND 20 POPS AS FAR EAST AS ROUGHLY HIGHWAY 83.
LATE TONIGHT INTO TOMORROW...THE CONVECTIVE OUTFLOW FROM WHATEVER
REMAINS OF THE MCS TONIGHT WILL PUSH THE STATIONARY FRONT FARTHER
SOUTH THAN WHERE IT IS NOW WITH A WEAK WAVE DEVELOPING ALONG THE
FRONT ACROSS SOUTH-CENTRAL KS BY DAYBREAK TUESDAY. WEST OF THE
WAVE...WINDS AT THE SURFACE WILL LIKELY BE MORE NORTHERLY ACROSS
MUCH OF THE DDC FORECAST AREA. TOMORROW`S FORECAST HIGH TEMPERATURE
HAS BEEN LOWERED TO MID-UPPER 90S FROM HAYS TO CIMARRON TO HUGOTON
AND POINTS WEST TO THE COLORADO BORDER. EVEN THE AREAS ACROSS SOUTH
CENTRAL KANSAS WILL BE SLIGHTLY NORTH OF THE FRONT MORE THAN LIKELY
AND HAVE LOWERED THE HIGHS IN MEDICINE LODGE AREA DOWN TO ABOUT
103-104F (WHICH MAY STILL BE A BIT TOO WARM IF THE FRONT ENDS UP
BEING JUST SOUTH OF THERE). AS FAR AS THUNDERSTORM POTENTIAL GOES
TOMORROW...IT WILL BE VERY SIMILAR TO TODAY...WITH THE GENERAL
THINKING BEING THAT ANYTHING THAT WOULD DEVELOP ALONG THE FRONT
WOULD BE VERY ISOLATED IN NATURE WITH THE MOST COHERENT CONVECTION
FORMING ONCE AGAIN OVER EASTERN COLORADO. WILL BE KEEPING POPS BELOW
15 EXCEPT NEAR THE COLORADO BORDER FOR LATE IN THE AFTERNOON TUESDAY
AS A RESULT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 AM CDT MON JUL 30 2012
.MONDAY NIGHT THROUGH THURSDAY...
THE LARGE UPPER LEVEL HIGH WILL BE THE MAIN FEATURE DURING THE
EXTENDED FORECAST AND BE LOCATED ACROSS THE CENTRAL PART OF THE
UNITED STATES WITH AN UPPER LEVEL LONG WAVE TROUGH POSITIONED ACROSS
THE EASTERN CONUS. A PERSISTENT FRONTAL BOUNDARY AT THE SURFACE WILL
BE LOCATED ACROSS WEST CENTRAL AND CENTRAL KANSAS WHICH WILL BE THE
MAIN AREA WHERE CONVECTION COULD OCCUR DURING THE AFTERNOON AND
EVENING HOURS. OTHERWISE EXPECT PARTLY CLOUDY SKIES ACROSS WESTERN
KANSAS. VERY WARM CONDITIONS WILL CONTINUE DURING THIS TIME FRAME
WITH HIGHS RANGING FROM AROUND 100 TO 110 WITH LOWS ONLY DIPPING
INTO THE LOWER TO MID 70S.
.THURSDAY NIGHT THROUGH SATURDAY...
THE AFOREMENTIONED UPPER LEVEL HIGH WILL BE PUSHED SOUTHWARD AS A
STRONG UPPER LEVEL LOW MOVES ACROSS THE NORTHERN PLAINS AND CENTRAL
CANADA. THIS FEATURE WILL HELP PUSH A SECOND FRONT DOWN THROUGH
WESTERN KANSAS. RAIN CHANCES WILL INCREASE ACROSS AS THIS COLD FRONT
MOVES THROUGH THE AREA BUT I HAVE KEPT POPS LOW DUE TO THE
UNCERTAINTY OF SPEED AND INTENSITY OF THIS SYSTEM. THIS FRONT SHOULD
ALLOW TEMPERATURES TO DECREASE SLIGHTLY WITH HIGHS RANGING FROM THE
UPPER 90S TO 103 DEGREES AND LOWS IN THE LOWER TO MID 70S.
.SATURDAY NIGHT THROUGH SUNDAY NIGHT...
THE WEATHER PATTERN BECOMES MORE UNCERTAIN SATURDAY NIGHT THROUGH
SUNDAY AS THE GFS KEEPS THE UPPER LEVEL HIGH ACROSS THE SOUTHERN
ROCKIES AND THE ECMWF REBUILDS THE HIGH OVER THE CENTRAL PLAINS.
NEVERTHELESS, BOTH SOLUTIONS WILL BRING PARTLY CLOUDY SKIES AND DRY
CONDITIONS ACROSS WESTERN KANSAS. HIGHS THROUGH THIS TIME FRAME WILL
GENERALLY BE AROUND 100 DEGREES WITH LOWS REMAINING IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1158 AM CDT MON JUL 30 2012
A WEAK STATIONARY FRONT WILL PERSIST ACROSS SOUTHWEST KANSAS THROUGH
TODAY AND TONIGHT. WHILE AN ISOLATED THUNDERSTORM MAY DEVELOP LATE
IN THE AFTERNOON/EVENING ANYWHERE ALONG THIS BOUNDARY...THE COVERAGE
IS NOT EXPECTED TO BE ENOUGH TO JUSTIFY INCLUSION IN THE TAFS. WILL
HOWEVER INCLUDE A PROB30 GROUP FOR THUNDERSTORMS AT GCK DURING THE
OVERNIGHT HOURS AS THERE IS A GREATER PROBABILITY OF A SMALL CLUSTER
OF STORMS TO MOVE EAST OUT OF EASTERN COLORADO AND PERHAPS AFFECT
GCK ALONG/NORTH OF THE MENTIONED STATIONARY FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 100 75 104 / 10 10 20 10
GCK 71 96 73 103 / 20 10 20 20
EHA 70 98 73 103 / 30 20 20 20
LBL 71 99 74 104 / 20 10 20 10
HYS 71 98 75 103 / 10 10 20 10
P28 75 104 78 108 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...UMSCHEID
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1159 AM CDT MON JUL 30 2012
...UPDATED SYNOPSIS AND AVIATION SECTION FOR 18Z TAFS...
.SYNOPSIS...
ISSUED AT 1158 AM CDT MON JUL 30 2012
AN UPPER LEVEL HIGH CONTINUED TO GRIP THE CENTRAL AND SOUTHERN GREAT
PLAINS. THE CENTER OF THE HIGH AT 500MB WAS LOCATED ACROSS THE
SOUTHERN TEXAS PANHANDLE PER RAOB AND RAP ANALYSIS AS OF 30.12Z. AN
ARC OF MID LEVEL MOISTURE COULD BE SEEN ON WATER VAPOR LOOP AND RAOB
ANALYSIS FROM WESTERN/CENTRAL ARIZONA THROUGH UTAH AND NORTHEAST TO
SOUTHEASTERN WYOMING AND WESTERN NEBRASKA. ALL ALONG THIS MOISTURE
ARC...THERE WERE MINOR MID LEVEL PERTURBATIONS IN THE FLOW PATTERN
DUE TO LATENT HEAT RELEASE FROM VARIOUS THUNDERSTORM CLUSTERS. A
MESOSCALE CONVECTIVE SYSTEM MOVED ACROSS SOUTHERN NEBRASKA/NORTHERN
KANSAS DURING THE OVERNIGHT HOURS WITH THE MID LEVEL POTENTIAL
VORTICITY ANOMALY TIED TO THIS MCS MOVING INTO EASTERN KS/WESTERN
MO. ADDITIONAL MID LEVEL VORTICITY COULD BE SEEN IN THE RAP ANALYSIS
MOVING INTO NORTHERN COLORADO WITH A 30-40 KNOT 400MB SPEED MAX
ROTATING NORTH-NORTHEASTWARD INTO THE COLORADO ROCKIES. IN THE LOWER
TROPOSPHERE...A STATIONARY FRONT EXTENDED FROM ROUGHLY BEAVER, OK TO
BUCKLIN, KS TO NEAR PRATT, KS AT 16Z. OKLAHOMA MESONET OBSERVATIONS
AT 1650Z REVEALED AN AXIS OF 102 TO 104F TEMPERATURES ACROSS
WEST-CENTRAL OKLAHOMA ON WEST-SOUTHWEST SURFACE WINDS SOUTH OF THIS
BOUNDARY.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 354 AM CDT MON JUL 30 2012
TODAY INTO TONIGHT WILL SEE THE MID/UPPER LEVEL PATTERN CHANGE
LITTLE AS A STRONG HIGH ANCHORS ACROSS THE CENTRAL/SOUTHERN HIGH
PLAINS WHILE A MODEST 70-80 KNOT UPPER JET SLIPS ACROSS THE DAKOTAS.
A MONSOONAL SUBTROPICAL MOISTURE PLUME WRAPPING AROUND THE BACK SIDE
OF THIS HIGH WILL CONTINUE TO STRETCH FROM THE DESERT SOUTHWEST INTO
THE CENTRAL HIGH PLAINS REGION WITH CONVECTION POSSIBLE ANYWHERE IN
THIS PLUME. NONETHELESS...THE DIRECT CIRCULATION ASSOCIATED WITH THE
ENTRANCE REGION OF THIS JET STREAK ALONG WITH OUTFLOW FROM
CONVECTION THIS PAST EVENING TO OVERNIGHT IS PUSHING A WEAK
FRONT/CONVECTIVE OUTFLOW INTO SOUTHWEST KANSAS THIS MORNING. THIS
BOUNDARY AND ITS POSITIONING LEADS TO SEVERAL QUESTIONS FOR THE
AFTERNOON TO EVENING HOURS.
INITIALLY FOR THE MORNING HOURS...THIS SETUP WILL ONLY RESULT IN A
WIND SHIFT FOR LOCATIONS MOSTLY NORTH OF HIGHWAY 50 AS THE BOUNDARY
SLOWS TO A STALL WHILE CONVECTION REMAINS NEAR THE NEBRASKA BORDER.
HOWEVER...AS THE MORNING GIVES WAY TO THE AFTERNOON HOURS...DEEP
THERMAL MIXING AND ASSOCIATED MOMENTUM TRANSFER FROM WINDS ALOFT MAY
MIX OUT THE SOUTHERN PERIPHERY OF THE BOUNDARY. NONETHELESS...THE
RAP MODEL HINTS AT A SMALL FRONTAL WAVE MOVING OVER SOUTHERN
KANSAS THAT COUNTERS ANY NORTHWARD MOVEMENT OF THE BOUNDARY. THIS
SETS UP A COMPLICATED HIGH TEMPERATURE SCENARIO BASED ON BOUNDARY
LOCATION. LOCATIONS SOUTH OF THE BOUNDARY WILL LIKELY SEE
TEMPERATURES A FEW DEGREES EITHER SIDE OF 105 AS THERMAL MIXING
EXPANDS TO LEVELS AT OR ABOVE 700 HPA WHERE TEMPERATURES OF +14 TO
+16C EXIST. NORTH OF THE BOUNDARY...HIGHS REALISTICALLY COULD
VARYING FROM 95 TO AROUND 100. GUESS AT THIS POINT IS FOR THE
DIVIDING LINE TO REMAIN ROUGHLY ALONG A HIGHWAY 56 LINE BUT THIS
WILL LIKELY NEED ADJUSTING THROUGH THE DAY. ALTHOUGH HEAT INDEX
VALUES WILL APPROACH ADVISORY LEVELS BY MID AFTERNOON SOUTH OF THE
BOUNDARY...THE SAME DEEP THERMAL MIXING BRINGING TEMPS AROUND 105
SHOULD AID IN LOWERING DEWPOINTS ENOUGH TO SUPPRESS HEAT INDEX
VALUES BELOW 105 FOR MOST OF THE DAY.
ATTENTION THEN TURNS TOWARD LATER THIS AFTERNOON TO EARLY EVENING ALONG
AND NORTH OF HIGHWAY 50. ALTHOUGH UPPER SUPPORT WILL BE
MARGINAL...MINIMAL INHIBITION DUE TO CONVECTIVE TEMPS BEING REACHED
AND A DEEP MONSOONAL MOISTURE PROFILE MAY TRIGGER ISOLATED
CONVECTION NORTH OF A GARDEN CITY TO ST JOHN LINE. SHEAR PROFILES
ALONG AND NORTH OF THE BOUNDARY WILL BE MODEST WITH 0-6KM BULK SHEAR
VALUES AROUND 25 TO 30 KNOTS WHILE ML CAPE VALUES ARE AROUND 1000
J/KG. BASED ON THIS SCENARIO...AN ISOLATED STRONG TO SEVERE
STORM CAPABLE OF PRODUCING WIND GUSTS UP TO 60 MPH AND QUARTER SIZE
HAIL CAN/T BE RULED OUT...ESPECIALLY WITH VEERING WINDS ABOVE 6 KM.
OTHERWISE...CONVECTION COMING OFF THE RATON MESA REGION IN COLORADO
MAY SLIP INTO FAR WESTERN KANSAS DURING THE EVENING HOURS BEFORE
FADING BY THE EARLY OVERNIGHT HOURS. OVERNIGHT LOWS WILL REMAIN
WARM WITH READINGS IN THE 70S LIKELY.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 303 AM CDT MON JUL 30 2012
.MONDAY NIGHT THROUGH THURSDAY...
THE LARGE UPPER LEVEL HIGH WILL BE THE MAIN FEATURE DURING THE
EXTENDED FORECAST AND BE LOCATED ACROSS THE CENTRAL PART OF THE
UNITED STATES WITH AN UPPER LEVEL LONG WAVE TROUGH POSITIONED ACROSS
THE EASTERN CONUS. A PERSISTENT FRONTAL BOUNDARY AT THE SURFACE WILL
BE LOCATED ACROSS WEST CENTRAL AND CENTRAL KANSAS WHICH WILL BE THE
MAIN AREA WHERE CONVECTION COULD OCCUR DURING THE AFTERNOON AND
EVENING HOURS. OTHERWISE EXPECT PARTLY CLOUDY SKIES ACROSS WESTERN
KANSAS. VERY WARM CONDITIONS WILL CONTINUE DURING THIS TIME FRAME
WITH HIGHS RANGING FROM AROUND 100 TO 110 WITH LOWS ONLY DIPPING
INTO THE LOWER TO MID 70S.
.THURSDAY NIGHT THROUGH SATURDAY...
THE AFOREMENTIONED UPPER LEVEL HIGH WILL BE PUSHED SOUTHWARD AS A
STRONG UPPER LEVEL LOW MOVES ACROSS THE NORTHERN PLAINS AND CENTRAL
CANADA. THIS FEATURE WILL HELP PUSH A SECOND FRONT DOWN THROUGH
WESTERN KANSAS. RAIN CHANCES WILL INCREASE ACROSS AS THIS COLD FRONT
MOVES THROUGH THE AREA BUT I HAVE KEPT POPS LOW DUE TO THE
UNCERTAINTY OF SPEED AND INTENSITY OF THIS SYSTEM. THIS FRONT SHOULD
ALLOW TEMPERATURES TO DECREASE SLIGHTLY WITH HIGHS RANGING FROM THE
UPPER 90S TO 103 DEGREES AND LOWS IN THE LOWER TO MID 70S.
.SATURDAY NIGHT THROUGH SUNDAY NIGHT...
THE WEATHER PATTERN BECOMES MORE UNCERTAIN SATURDAY NIGHT THROUGH
SUNDAY AS THE GFS KEEPS THE UPPER LEVEL HIGH ACROSS THE SOUTHERN
ROCKIES AND THE ECMWF REBUILDS THE HIGH OVER THE CENTRAL PLAINS.
NEVERTHELESS, BOTH SOLUTIONS WILL BRING PARTLY CLOUDY SKIES AND DRY
CONDITIONS ACROSS WESTERN KANSAS. HIGHS THROUGH THIS TIME FRAME WILL
GENERALLY BE AROUND 100 DEGREES WITH LOWS REMAINING IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1158 AM CDT MON JUL 30 2012
A WEAK STATIONARY FRONT WILL PERSIST ACROSS SOUTHWEST KANSAS THROUGH
TODAY AND TONIGHT. WHILE AN ISOLATED THUNDERSTORM MAY DEVELOP LATE
IN THE AFTERNOON/EVENING ANYWHERE ALONG THIS BOUNDARY...THE COVERAGE
IS NOT EXPECTED TO BE ENOUGH TO JUSTIFY INCLUSION IN THE TAFS. WILL
HOWEVER INCLUDE A PROB30 GROUP FOR THUNDERSTORMS AT GCK DURING THE
OVERNIGHT HOURS AS THERE IS A GREATER PROBABILITY OF A SMALL CLUSTER
OF STORMS TO MOVE EAST OUT OF EASTERN COLORADO AND PERHAPS AFFECT
GCK ALONG/NORTH OF THE MENTIONED STATIONARY FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 101 72 105 75 / 20 20 20 20
GCK 99 71 102 73 / 20 20 20 20
EHA 99 70 102 73 / 20 30 20 20
LBL 101 71 104 74 / 10 20 20 20
HYS 99 71 101 75 / 10 20 20 20
P28 108 75 107 78 / 10 10 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...UMSCHEID
SHORT TERM...AJOHNSON
LONG TERM...HOVORKA_42
AVIATION...UMSCHEID
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
304 PM EDT MON JUL 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A WARM SUMMER AFTERNOON EVENING. INCREASING
HUMIDITY AND A SLOW EASTBOUND LOW PRESSURE SYSTEM WILL FUEL
SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
RECENT SATELLITE SATELLITE DATA AND RAP MODEL OUTPUT SHOW SOME
CUMULUS BUILD UPS WITHIN THE UPPER OHIO VALLEY, CONFINED TO AREAS
JUST SOUTH OF LAKE ERIE OR NEAR THE APPALACHIAN MOUNTAINS. RAP
MODEL OUTPUT SUGGESTS SLIGHTLY INCREASED INSTABILITY IN THESE
LOCATIONS, WHERE EITHER H8 TEMPERATURES ARE SLIGHTLY WARMER OR H5
TEMPERATURES ARE SLIGHTLY COLDER. RECENT SURFACE DATA CONTINUES TO
SHOW NO MORE THAN SEASONABLE HUMIDITY VALUES ACROSS THE UPPER OHIO
VALLEY, SO INSTABILITY OF THE LIFTED PARCELS MAY BE RESTRICTED BY
DRY AIR ENTRAINMENT. HENCE HAVE MAINTAINED NO MORE THAN A SLIGHT
CHANCE OF THUNDERSTORMS NEAR THE MOUNTAINS DUE TO OROGRAPHIC
ENHANCEMENT.
SOUTHERLY LOW LEVEL WINDS WILL INCREASE HUMIDITY VALUES OVERNIGHT
AND TUESDAY. WHILE RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A
LOW PRESSURE TROUGH WILL MOVE SLOWLY SOUTHEASTWARD THROUGH THE
GREAT LAKES. SO EXPECT MORE OF A CHANCE OF THUNDERSTORMS BY
TUESDAY AFTERNOON AS DAYTIME HEATING INCREASES THE INSTABILITY AND
PRE-SYSTEM CONVERGENCE INCREASES LIFT AND STORM ORGANIZATION.
CONCUR WITH SPC THAT THE RISK OF SEVERE REMAINS RESTRICTED DUE TO
WEAK VERTICAL SHEAR. LIKEWISE, THUNDERSTORM RAINFALL MAY BE
RESTRICTED, AS HUMIDITY VALUES DO NOT APPEAR EXTRAORDINARILY LARGE
NOR STORM MOVEMENTS EXTRAORDINARILY SLOW.
FORECASTED TEMPERATURES A COUPLE DEGREES WARMER THAN NORMAL USING
BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW THE LIFT-PRODUCING LOW
PRESSURE TROUGH EXITING EAST PAST THE APPALACHIAN MOUNTAINS
DAYTIME WEDNESDAY. SO HAVE MAINTAINED A CHANCE OF SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT, WITH CHANCES TRENDING LOWER WEST TO
EAST ACROSS THE UPPER OHIO VALLEY WEDNESDAY. THIS IS DESPITE
HUMIDITY VALUES REMAINING ABOVE NORMAL, WITH SURFACE DEW POINTS IN
THE MID 60S, INTO THURSDAY.
BASED ON RECENT GFS, NAM, AND ECMWF MOS, FORECASTED TEMPERATURE
GENERALLY ABOUT 5 DEGREES WARMER THAN NORMAL EACH PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
SLIGHTLY UNSETTLED PATTERN FOR THE LONG TERM PORTION OF THE
FORECAST. TRENDED AWAY FROM THE ECMWF...WHICH SEEMED TO HANG A FRONT
OVER THE REGION MUCH LONGER THAN OTHER DETERMINISTIC/ENSEMBLE
MODELS. BEST CHANCE FOR RAIN APPEARS TO BE SUNDAY INTO SUNDAY
NIGHT...WITH SOME TIMING CONSENSUS FOR FRONT FROM GFS/CMC/GEFS.
TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL BEFORE THE FRONTAL
PASSAGE...RETURNING TO NORMAL BY SUNDAY AND MONDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
EXPECT SCATTERED LOW CLOUDS TO REMAIN IN THE FORECAST FOR THE ENTIRE
TAF PERIOD. ALTHOUGH THERE WILL BE SOME ISOLATED SHOWERS/STORMS IN
THE RIDGES...NOT ENOUGH CONFIDENCE THAT PRECIP WILL REACH MGW OR LBE
TO INCLUDE IN TAFS. WINDS WILL GENERALLY BE LIGHT AND OUT OF THE
SOUTHEAST. IF WINDS DO MANAGE TO GO CALM TONIGHT...SOME MVFR
VISIBILITIES CANNOT BE RULED OUT.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
SCATTERED SHOWERS/STORMS ARE MORE LIKELY TUESDAY INTO
WEDNESDAY...WITH GENERALLY DRY CONDITIONS EXPECTED FOR THURSDAY
AND FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN IN SCATTERED
SHOWERS/STORMS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
251 PM EDT MON JUL 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE A WARM SUMMER AFTERNOON EVENING. INCREASING
HUMIDITY AND A SLOW EASTBOUND LOW PRESSURE SYSTEM WILL FUEL
SCATTERED SHOWERS AND THUNDERSTORMS TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
RECENT SATELLITE SATELLITE DATA AND RAP MODEL OUTPUT SHOW SOME
CUMULUS BUILD UPS WITHIN THE UPPER OHIO VALLEY, CONFINED TO AREAS
JUST SOUTH OF LAKE ERIE OR NEAR THE APPALACHIAN MOUNTAINS. RAP
MODEL OUTPUT SUGGESTS SLIGHTLY INCREASED INSTABILITY IN THESE
LOCATIONS, WHERE EITHER H8 TEMPERATURES ARE SLIGHTLY WARMER OR H5
TEMPERATURES ARE SLIGHTLY COLDER. RECENT SURFACE DATA CONTINUES TO
SHOW NO MORE THAN SEASONABLE HUMIDITY VALUES ACROSS THE UPPER OHIO
VALLEY, SO INSTABILITY OF THE LIFTED PARCELS MAY BE RESTRICTED BY
DRY AIR ENTRAINMENT. HENCE HAVE MAINTAINED NO MORE THAN A SLIGHT
CHANCE OF THUNDERSTORMS NEAR THE MOUNTAINS DUE TO OROGRAPHIC
ENHANCEMENT.
SOUTHERLY LOW LEVEL WINDS WILL INCREASE HUMIDITY VALUES OVERNIGHT
AND TUESDAY. WHILE RECENT SREF MODEL OUTPUT CONTINUES TO SHOW A
LOW PRESSURE TROUGH WILL MOVE SLOWLY SOUTHEASTWARD THROUGH THE
GREAT LAKES. SO EXPECT MORE OF A CHANCE OF THUNDERSTORMS BY
TUESDAY AFTERNOON AS DAYTIME HEATING INCREASES THE INSTABILITY AND
PRE-SYSTEM CONVERGENCE INCREASES LIFT AND STORM ORGANIZATION.
CONCUR WITH SPC THAT THE RISK OF SEVERE REMAINS RESTRICTED DUE TO
WEAK VERTICAL SHEAR. LIKEWISE, THUNDERSTORM RAINFALL MAY BE
RESTRICTED, AS HUMIDITY VALUES DO NOT APPEAR EXTRAORDINARILY LARGE
NOR STORM MOVEMENTS EXTRAORDINARILY SLOW.
FORECASTED TEMPERATURES A COUPLE DEGREES WARMER THAN NORMAL USING
BLEND OF RECENT GFS AND NAM MOS.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT CONTINUES TO SHOW THE LIFT-PRODUCING LOW
PRESSURE TROUGH EXITING EAST PAST THE APPALACHIAN MOUNTAINS
DAYTIME WEDNESDAY. SO HAVE MAINTAINED A CHANCE OF SHOWERS AND
THUNDERSTORMS TUESDAY NIGHT, WITH CHANCES TRENDING LOWER WEST TO
EAST ACROSS THE UPPER OHIO VALLEY WEDNESDAY. THIS IS DESPITE
HUMIDITY VALUES REMAINING ABOVE NORMAL, WITH SURFACE DEW POINTS IN
THE MID 60S, INTO THURSDAY.
BASED ON RECENT GFS, NAM, AND ECMWF MOS, FORECASTED TEMPERATURE
GENERALLY ABOUT 5 DEGREES WARMER THAN NORMAL EACH PERIOD.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
SLIGHTLY UNSETTLED PATTERN FOR THE LONG TERM PORTION OF THE
FORECAST. TRENDED AWAY FROM THE ECMWF...WHICH SEEMED TO HANG A FRONT
OVER THE REGION MUCH LONGER THAN OTHER DETERMINISTIC/ENSEMBLE
MODELS. BEST CHANCE FOR RAIN APPEARS TO BE SUNDAY INTO SUNDAY
NIGHT...WITH SOME TIMING CONSENSUS FOR FRONT FROM GFS/CMC/GEFS.
TEMPERATURES WILL BE SLIGHTLY ABOVE NORMAL BEFORE THE FRONTAL
PASSAGE...RETURNING TO NORMAL BY SUNDAY AND MONDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
EXPECT SCATTERED LOW CLOUDS TO REMAIN IN THE FORECAST FOR THE ENTIRE
TAF PERIOD. ALTHOUGH THERE WILL BE SOME ISOLATED SHOWERS/STORMS IN
THE RIDGES...NOT ENOUGH CONFIDENCE THAT PRECIP WILL REACH MGW OR LBE
TO INCLUDE IN TAFS. WINDS WILL GENERALLY BE LIGHT AND OUT OF THE
SOUTHEAST. IF WINDS DO MANAGE TO GO CALM TONIGHT...SOME MVFR
VISIBILITIES CANNOT BE RULED OUT.
OUTLOOK...TUESDAY NIGHT THROUGH SATURDAY...
SCATTERED SHOWERS/STORMS ARE MORE LIKELY TUESDAY INTO
WEDNESDAY...WITH GENERALLY DRY CONDITIONS EXPECTED FOR THURSDAY
AND FRIDAY. RESTRICTIONS WILL BE POSSIBLE AGAIN IN SCATTERED
SHOWERS/STORMS SATURDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
113 PM EDT MON JUL 30 2012
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 443 AM EDT MON JUL 30 2012
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW WNW FLOW ALF OVER
THE UPR GRT LKS BTWN GENERAL TROFFING CENTERED NEAR HUDSON BAY AND
PERSISTENT RDG AXIS OVER THE HI PLAINS. WITH LOSS OF DAYTIME
HEATING...SHRA/TS THAT IMPACTED THE CWA LAST EVNG HAVE DIMINISHED.
BUT ANOTHER LINE OF SHRA/TS IS PUSHING SEWD THRU THE MN ARROWHEAD IN
ADVANCE OF POTENT SHRTWV MOVING ESEWD IN MANITOBA TOWARD NW MN AND
LEFT EXIT OF SUPPORTING 75KT H3 JET MAX NOTED IN THE NRN PLAINS.
THIS LINE OF TS PROMPTED THE ISSUANCE OF A WATCH FOR MUCH OF NE
MN...WITH SOME SVR TS GIVEN STEEP MID LVL LAPSE RATES SHOWN ON THE
00Z INL RAOB THAT CONTRIBUTED TO MUCAPE IN EXCESS OF 2000 J/KG AS
WELL AS EFFECTIVE DEEP LYR SHEAR UP TO 40KTS UNDER UNIDIRECTIONAL
WNW FLOW ALF PER SPC ANALYSIS. PRESENCE OF DRIER AIR ALF SHOWN ON
00Z RAOBS HAS CONTRIBUTED TO DCAPE AOA 1000 J/KG IN PORTIONS OF THE
AREA IMPACTED BY THE WATCH. RECENT TRENDS HOWEVER ARE FOR THE STORMS
TO WEAKEN AS THEY MOVE INTO A BIT MORE STABLE AIR IMPACTED BY
NOCTURNAL COOLING AND AXIS OF LOWER H85 DEWPTS OVER CENTRAL MN.
MAIN FCST CONCERNS THIS PACKAGE INCLUDE CONVECTIVE TRENDS INTO TNGT
AND POTENTIAL FOR SVR STORMS.
TODAY...VIGOROUS SHRTWV TO THE NW IS PROGGED TO MOVE TO JUST N OF
INL AT 12Z MON AND THEN INTO FAR NE LK SUP BY 00Z TUE WITH SWATH OF
VIGOROUS DVPA/DEEP LYR QVECTOR CNVGC MOVING W-E ACRS UPR MI.
ALTHOUGH AXIS OF LOWER H85 THETA E CONTRIBUTING TO WEAKENING STORMS
IN MN NOW MAY TEND TO REDUCE COVERAGE/INTENSITY THIS MRNG...ONSET OF
DAYTIME HEATING AND ARRIVAL OF MORE IMPRESSIVE H85 THETA E ADVECTION
BY THIS AFTN IN PRESENCE OF THE HEFTY DYNAMICS SHOULD LEAD TO NMRS
SHRA/TS...ESPECIALLY OVER THE CNTRL AND E WHERE ARRIVAL OF DYNAMICS
APPEAR TO BE MOST IN SYNC WITH DAYTIME HEATING. NAM/GFS FCST SNDGS
INDICATE SBCAPE WL REACH AOA 2000 J/KG AS HI TEMPS RISE WELL INTO
THE 80S AWAY FM LK MODERATION MOST PRONOUNCED OFF LK MI. DRYING ALF
UNDER UNIDIRECTIONAL WNW FLOW ON THE SRN FLANK OF SHRTWV TRACK IS
FCST TO CONTRIBUTE TO SFC-10K FT AGL DELTA THETA E UP TO 25C...VERY
FAVORABLE PER THE MQT SEVERE WX CHECKLIST TO ENHANCE DCAPE. THE
BIGGEST DRAWBACK FOR ORGANIZED SEVERE WX IS FCST RATHER MODEST DEEP
LYR SHEAR ONLY 25-30KTS. THIS WEAKER SHEAR MAY RESULT IN MORE PULSE
SVR EPISODES...WITH THE BETTER CHC FOR ORGANIZED STORMS WHERE LK
BREEZE CNVGC OVER MAINLY THE E HALF MIGHT ENHANCE THE SHEAR AS WELL
AS INCRS LLVL CNVGC AND SHRA/TS COVERAGE. SHRA/TS WL DIMINISH OVER
THE W IN THE AFTN WITH ARRIVAL OF DNVA/DEEP LYR QVECTOR DVGC/LLVL
DRYING IN THE WAKE OF SHRTWV PASSAGE/ATTENDANT COLD FROPA.
TNGT...DRYING/NEGATIVE H85 THETA E ADVECTION IN THE WAKE OF SHRTWV
MOVING INTO SE ONTARIO AND LOSS OF DAYTIME HEATING WL CAUSE SHRA/TS
TO DIMINISH NW-SE. HOWEVER...MODELS SHOW QUITE A BIT OF LINGERING
LLVL MSTR WITH NNW FLOW IN THE WAKE OF DEPARTING SHRTWV/SFC LO. LO
CLDS MAY BE ESPECIALLY TENACIOUS IN THE UPSLOPE AREAS NEAR LK SUP...
WHERE THERE MAY EVEN BE SOME -DZ/SPRINKLES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 443 AM EDT MON JUL 30 2012
VERY ACTIVE FORECAST PERIOD...AS UPPER MI SITS IN AN UPPER LEVEL
TROUGHING PATTERN THROUGH TUESDAY...BEFORE STRONG RIDGING PATTERN
OVER MUCH OF THE CONUS BEGINS TO MOVE EASTWARD INTO THE REGION.
ALONG THIS RIDGE...SEVERAL SHORTWAVES WILL PASS OVER UPPER MI
BRINGING CHANCES FOR TSRA WED AND THUR AND THEN AGAIN DURING THE
WEEKEND.
AFTER EXITING 500MB SHORTWAVE DURING THE DAY TUESDAY...STRONG
RIDGING WILL BEGIN TO PUSH IN FROM WEST TO EAST...WHICH WILL ALSO
TRANSLATE TO SURFACE HIGH PRESSURE. AS WINDS TURN TO A NORTHERLY
DIRECTION...EXPECT AN INFLUX OF DRY AIR AND CLEARING SKIES ACROSS
THE REGION. SUCH A WIND DIRECTION WILL CAUSE HIGH TEMPERATURES TO BE
SLIGHTLY COOLER THAN THE PREVIOUS DAY...BUT STILL A QUITE
COMFORTABLE MID 70 TO LOW 80 DEGREE RANGE. WINDS WILL THEN TURN TO A
MORE SOUTHERLY DIRECTION ON THE BACKSIDE OF THE SURFACE
HIGH...ALLOWING WARMER WINDS OFF THE LAKE DURING THE FIRST PART OF
THE NIGHT...AND THEN SOUTHERLY WINDS ACROSS THE INTERIOR FOR THE
LAST HALF. THIS SHOULD MODERATE TEMPERATURES TO STAY AT OR ABOVE
NORMAL. UNFORTUNATELY...SURFACE HIGH PRESSURE WILL BE SHORT-LIVED AS
THE FIRST OF SEVERAL SHORTWAVES BEGINS TO TRAVERSE THE AREA BY LATE
WEDNESDAY WITH UPPER LEVEL RIDGING IN PLACE.
MAIN SHORTWAVE AND SURFACE LOW PRESSURE WILL SPREAD ACROSS LAKE
SUPERIOR LATE WEDNESDAY AND THROUGH THE DAY THURSDAY. HOWEVER THERE
IS SOME DISCREPANCY BETWEEN THE MODELS...AS THE NAM IS SLIGHTLY
DELAYED IN THE ARRIVAL OF THE SYSTEM...AND IS MUCH MORE AMPLIFIED
THAN THE OTHER MODELS. REGARDLESS...OVERALL EFFECTS OF THE SYSTEM
WILL BE SIMILAR...STARTING WITH THE INFLUX OF MOIST SOUTHERLY WINDS
/LLVL JET/ AHEAD OF THE SYSTEM AND DECENT WAA. THIS WILL ALLOW HIGH
TEMPERATURES WEDNESDAY TO RISE TO WELL ABOVE NORMAL INLAND /MID TO
UPPER 80S POSSIBLE/. WITH PRESENCE OF AFTERNOON LAKE BREEZES...AND
WARM/MOIST/UNSTABLE AIR IN PLACE...SHOULD SEE SOME AFTERNOON
CONVECTION INLAND AS A RESULT.
AS SYSTEM NEARS...EXPECT A WELL DEFINED AREA OF CONVERGENCE TO SPAWN
PRECIP ACROSS THE ENTIRE CWA WEDNESDAY NIGHT THROUGH
THURSDAY...DESPITE OUR LOCATION IN THE RIGHT EXIT REGION OF A VERY
WEAK JET. MU CAPE VALUES ARE POINTING AT CENTRAL AND WESTERN UPPER
MI GETTING UP TO BETWEEN 1.4-1.8K J/KG IN WEDNESDAY EVENING...AND
THEN MAXING OUT AROUND 2K J/KG OVERNIGHT...THOUGH CAPE WILL BE
FAIRLY SKINNY AND MAINLY CONFINED TO THE MID AND UPPER LEVELS WITH
THE BEST MOISTURE...WHILE THE LOWER LEVELS SHOULD REMAIN FAIRLY DRY.
THAT BEING SAID...MODEL SOUNDINGS SHOW SOME IMPRESSIVE SHEAR
THROUGHOUT THE ENTIRE COLUMN /BOTH DIRECTIONAL AND SPEED/ SO COULD
SEE SOME WIDESPREAD ELEVATED TSRA DEVELOPMENT...BUT WITH LITTLE
MOISTURE IN THE LOW LEVELS...SHOULD/T BE MUCH OF A RAIN SOAKER.
SHORTWAVE AND BEST FORCING SHOULD MOVE OFF TO THE EAST DURING THE
DAY THURSDAY AHEAD OF SURFACE COLD FRONT...BUT THE BREAK IN PRECIP
WILL BE SHORT-LIVED AS LARGER 500MB SHORTWAVE OVER SASKATCHEWAN
FRIDAY AFTERNOON BEGINS TO MOVE ALONG THE SAME TRACK SOUTHEAST
TOWARDS THE UPPER GREAT LAKES. WHILE ALL MODELS ARE IN GOOD
AGREEMENT OF THIS LOW STRENGTHENING AND BECOMING CLOSED OFF AS IT
REACHES THE UPPER GREAT LAKES...THERE IS LITTLE AGREEMENT IN THE
EXACT TIMING AND TRACK...SO WILL GO WITH A GENERAL MODEL CONSENSUS
AT THIS TIME. WITH SOME LOW LEVEL MOISTURE FROM PREVIOUS SYSTEM
ALREADY IN PLACE...COULD SEE SOME SCATTERED SHRA/TSRA DEVELOPMENT AS
EARLY AS FRIDAY MORNING FAR WEST WITH THIS SYSTEM. A STRONG UPPER
LEVEL JET WILL CRUISE OVER UPPER MI BY SATURDAY PUTTING US IN THE
LEFT ENTRANCE REGION...FURTHERING ENHANCING PRECIP CHANCES. PWAT
VALUES WILL QUICKLY RISE TO 160 PERCENT OF NORMAL THROUGH SATURDAY
MORNING AS SURFACE WARM FRONT AND WELL DEFINED AREA OF QVECTOR CONV
TRAVERSES FROM WEST TO EAST. UNLIKE WEDNESDAY NIGHT/THURSDAY...THIS
SYSTEM WILL HAVE ABUNDANT MOISTURE THROUGH ALL LAYERS...SO EXPECT
THIS TO BE A GOOD RAIN EVENT. BY SATURDAY AFTERNOON COLD FRONT WILL
PRESENT IMPRESSIVE FORCING...LATEST GFS HAS 0-3KM COMPUTED CAPE
VALUES MAXING OUT AROUND 1.2K SOUTH CENTRAL...WITH MU CAPE VALUES
2.2-2.6K J/KG OVER MUCH OF THE WESTERN AND CENTRAL CWA. FORECAST
SOUNDINGS SHOW MUCH IMPROVEMENT OVER THE SKINNY ELEVATED CAPE DURING
PREVIOUS EVENT...AND ONCE AGAIN SHEAR LOOKS TO BE VERY IMPRESSIVE
BOTH FOR DIRECTION AND SPEED. DCAPE ON THE OTHER HAND WILL BE ON THE
DIMINISHING TREND DURING THE DAY SATURDAY...SO ONCE STORMS DEVELOP
EXPECT THE MAIN THREAT TO BE HEAVY RAINS...ABUNDANT LIGHTNING...AND
POTENTIAL HAIL.
THE SYSTEM WILL CONTINUE ON ITS TRACK TO THE SOUTHEAST DURING THE
NIGHT SATURDAY...WITH A WELCOME BREAK IN PRECIP BY SUNDAY AFTERNOON
AS HIGH PRESSURE ONCE AGAIN REGAINS CONTROL
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 112 PM EDT MON JUL 30 2012
TOUGH FORECAST FOR THIS AFTERNOON WITH CONFIDENCE LOW IN HOW THE
CONVECTION WILL PLAY OUT THIS AFTERNOON AS A COLD FRONT MOVES
THROUGH. A DISTURBANCE AND ATTENDANT COLD FRONT WITH MOIST UNSTABLE
AIRMASS AT TIME OF PEAK DAYTIME HEATING WILL REDEVELOP SOME SHRA/TS
THIS AFTN AT SAW. SUSPECT THIS ACTIVITY WILL IMPACT MAINLY SAW AS
DRIER AIR WL BE MAKING ITS WAY INTO WRN UPR MI BY THE TIME PEAK
HEATING COMMENCES. SO INCLUDED SPECIFIC MENTION OF TS ONLY AT SAW.
FOLLOWING THE COLD FROPA...FAIRLY HUMID LLVL AIR WL LINGER. SO WITH
UPSLOPE NNW WIND DVLPG BEHIND THE FROPA...EXPECT LO CLDS/FOG/IFR
CONDITIONS AT ALL 3 SITES PER VARIOUS MOS FCST PRODUCTS TONIGHT. THE
LOW CLOUDS AND FOG WILL BURN OFF TUE MORNING AND CONDITIONS WILL
RETURN TO VFR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 443 AM EDT MON JUL 30 2012
EXPECT SSW WINDS UP TO 20 KTS AND SOME TS IN ADVANCE OF LO PRES TROF
THAT IS FORECAST TO DRIFT ACROSS LAKE SUPERIOR LATE TODAY AND
TONIGHT. BEHIND THE TROF PASSAGE...WINDS WILL SHIFT TO THE NNW AS
HIGH PRESSURE SETS IN...HOWEVER THE W LAKE COULD CONTINUE TO SEE
GUSTS BETWEEN 15 AND 20 KNOTS THROUGH THE MORNING HOURS WITH THIS
WIND DIRECTION. ANOTHER TROF WILL BRING TSRA CHANCES WEDNESDAY
AFTERNOON THROUGH TUESDAY EVENING...AND AGAIN BY FRIDAY. OTHERWISE
EXPECT WINDS TO REMAIN BELOW 15 KNOTS ACROSS THE LAKE FOR THE FCST
PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...JMW
AVIATION...07
MARINE...KC
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
349 PM CDT MON JUL 30 2012
.SHORT TERM...
ISSUED AT 344 PM CDT MON JUL 30 2012
(TONIGHT)
EXTENSIVE AREA OF MID AND HIGH CLOUDS HAVE HELPED HOLD TEMPERATURES
BACK OVER MOST OF THE REGION TODAY. SURFACE REPORTS FROM THE LARGE
AREA OF RETURNS ON RADAR ARE MAINLY SPRINKLES. THIS IS BEING
GENERATED BY A VORT MAX THAT WILL MOVE SOUTH INTO THE SOUTHERN CWA
BY 00Z. THERE IS LITTLE LOW LEVEL FORCING ASSOCIATED WITH IT
ACCORDING TO THE RAP UNTIL AFTER 00Z...AND EVEN THEN IT IS QUITE
WEAK. THINK GOING SLIGHT CHANCES FOR SHOWERS/THUNDERSTORMS STILL
LOOKS OKAY GIVEN SLIGHTLY BETTER LOW LEVEL FORCING AND MORE
INSTABILITY. OTHERWISE CHANCES SHOULD DECREASE WITH TIME AS THE
LOW MOVES FARTHER SOUTH.
BRIIT
&&
.LONG TERM...
ISSUED AT 344 PM CDT MON JUL 30 2012
(TUESDAY THROUGH NEXT MONDAY)
MAIN CONCERN ONCE AGAIN IS HEAT. HAVE ISSUED A HEAT ADVISORY JUST
FOR THE ST. LOUIS METRO AREA ON TUESDAY AFTERNOON AS IT CURRENTLY
LOOKS LIKE HEAT INDEX READINGS WILL CLIMB TO AROUND 105 DURING THE
AFTERNOON.
GFS/NAM ARE IN RELATIVELY GOOD AGREEMENT THAT A WEAK COLD FRONT WILL
BE MOVING SOUTH OUT OF THE UPPER MIDWEST INTO NORTHERN MISSOURI AND
CENTRAL ILLINOIS AROUND MIDDAY TOMORROW. DO NOT EXPECT MUCH CLOUDS
AND ANY RAIN CHANCES WITH THIS FRONT AS WE WILL LIE UNDER SUBSIDENCE
BETWEEN A SHORTWAVE TROUGH MOVING THROUGH THE GREAT LAKES AND A
VORT MAX MOVING ACROSS SOUTHWEST MISSOURI. NAM FORECAST SOUNDINGS
SHOWING DEEP MIXING TO 700MB AHEAD OF THE FRONT WHICH SUPPORTS
GOING HIGHS WHICH ARE CLOSE TO THE NAM MOS TEMPERATURES WHICH HAVE
VERIFIED BETTER THIS SUMMER. DEWPOINTS SHOULD FALL INTO THE UPPER
50S TO LOWER 60S WITH THE MIXING...WHICH COMBINED WITH HIGHS
RISING TO AROUND 104 RESULT IN HEAT INDEX HIGHS BRIEFLY REACHING
105 TOMORROW AFTERNOON. TEMPERATURES ON WEDNESDAY LOOK TO BE NOT
AS WARM BEHIND THE FRONT...SO HEAT INDEX READINGS ARE EXPECTED TO
STAY BELOW 100 DEGREES. ANOTHER FRONT MOVES INTO NORTHERN MISSOURI
LATE THURSDAY/THURSDAY NIGHT...WITH THE GFS BRINGING IT THROUGH
THE AREA AND THE ECMWF KEEPING IT STALLED TO THE NORTH AS THE
UPPER FLOW BECOMES ZONAL. HAVE GONE WITH JUST A SLIGHT CHANCE FOR
SHOWERS/STORMS ON THURSDAY AND TEMPERATURES IN THE UPPER 90S WHICH
SHOULD RESULT IN HEAT INDEX READINGS BETWEEN 98-103.
GENERALLY STAYED WITH THE ECMWF OVER THE WEEKEND. SHOULD BE SOME
INCREASE IN LOW LEVEL FORCING AHEAD OF A COLD FRONT THAT WILL MOVE
ACROSS THE AREA ON SUNDAY...SO HAVE KEPT A CHANCE OF SHOWERS AND
THUNDERSTORMS GOING AHEAD OF IT. WITH 850MB TEMPS STAYING ABOVE
20C...HIGH TEMPERATURES SHOULD REMAIN ABOVE 90 THROUGH THE PERIOD.
BRITT
&&
.AVIATION...
ISSUED AT 1236 PM CDT MON JUL 30 2012
VFR CONDITIONS EXPECTED AT ALL TAF SITES THROUGH THE FORECAST
PERIOD. WEAK LOW PRESSURE TO THE SOUTH OF KSTL WILL CONTINUE
MOVING SOUTHEASTWARD TODAY INTO TONIGHT. A FEW SPRINKLES ARE
POSSIBLE AT KUIN THROUGH AROUND 00Z AS AN UPPER LEVEL DISTURBANCE
MOVES THROUGH. A WEAK FRONT WILL APPROACH KUIN TAF SITE BY AROUND
12Z...THEN CONTINUE TO SINK TO THE SOUTH REACHING KSTL BY AROUND
18Z. NORTHWEST TO NORTH WINDS WILL INCREASE BEHIND THE
FRONT...HOWEVER NO PRECIPITATION IS EXPECTED.
SPECIFICS FOR KSTL...VFR CONDITIONS WILL CONTINUE...AS ONLY HIGH
CLOUDS ARE EXPECTED FOR THE REMAINDER OF THE DAY. SLOW CLEARING
SHOULD BEGIN AFTER SUNSET. LIGHT NORTH WINDS WILL BECOME VARIABLE
NEAR SUNSET...THEN INCREASE BY LATE TUESDAY MORNING AS A FRONT
APPROACHES.
BROWNING
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY FROM NOON TO 8 PM CDT TUESDAY FOR JEFFERSON MO-ST.
CHARLES MO-ST. LOUIS CITY MO-ST. LOUIS MO.
IL...HEAT ADVISORY FROM NOON TO 8 PM CDT TUESDAY FOR MADISON IL-
MONROE IL-ST. CLAIR IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
333 PM CDT MON JUL 30 2012
.DISCUSSION...
MOISTURE AS INDICATED ON SFC OBS SHOWING DEW PTS IN THE 60S AND
SATELLITE TPW PRECIPITABLE WATER ESTIMATES NEAR 1.3 INCHES OR HIGHER
ACROSS SWRN NEB WOULD SUGGEST A REASONABLE CHANCE OF TSTMS GIVEN
THE WEAK DISTURBANCE MOVING THROUGH NRN COLO THIS AFTN. HOWEVER
THE HRRR AND THE RAP MODELS ARE VERY QUIET GENERATING LIMITED CONVECTIVE
ACTIVITY ACROSS THE HIGH PLAINS. THIS COULD BE THE RESULT OF WEAK
UPSLOPE ADVECTION...A MID LEVEL SUBSIDENCE/CAP AND WEAK STEERING
CURRENTS. MEANWHILE THE KLNX VWP INDICATES A VERY DEEP BUT WEAK
EAST WINDS EXTENDING ALL THE WAY TO 12 KFT ASL.
THE FCST THIS EVENING CALLS FOR ISOLATED STORMS GENERALLY ALONG
AND WEST OF HIGHWAY 61. WE WILL CONTINUE TO CLOSELY MONITOR THE
CONVECTION DEVELOPING IN COLO AND OBVIOUS DEEP MOISTURE PLUME
ACROSS SWRN NEB. UPSLOPE FLOW MAY INCREASE LATE THIS AFTN AND
EARLY THIS EVENING ENHANCING CONVERGENCE. THE MODERATE CU FORMING
SOUTH OF THE WEATHER OFFICE AND CIGS NEAR 5 KFT AT HOLYOKE SUGGEST
ATLEAST SOME POTENTIAL FOR ORGANIZED STORM DEVELOPMENT IF THE
DISTURBANCE ACROSS COLO CAN REACH SWRN NEB BY EARLY EVENING.
ON TUESDAY...LOW PRESSURE WILL BEGIN TRACKING THROUGH THE NRN
PLAINS WHILE HIGH PRESSURE CONTINUES ACROSS ERN NEB. THIS SHOULD
PRODUCE COOLER TEMPS SOUTH AND EAST IN THE SOUTH-SOUTHEAST WIND
AREA AND VERY WARM TEMPS ACROSS THE NW ZONES WHERE DOWN SLOPING
SOUTHWEST WINDS MAY DEVELOP. THE MOISTURE PLUME BECOMES DIFFUSE
AND LESS FOCUSED AS IT IS DRAWN NORTH IN ALL MODELS EXCEPT THE GFS
WHICH EXPLODES WEDNESDAY EVENING OVER SRN SD/NCNTL NEB AS A COLD
FRONT APPROACHES THE FCST AREA. THE FATE OF THIS MOISTURE PLUME
THE POTENTIAL FOR DESPERATELY NEEDED RAINFALL MIGHT BEST BE
HANDLED INSIDE 12 HRS. THE OTHER MODELS ARE NOT GENERATING MUCH
QPF...POSSIBLY THE RESULT OF WARM MIDLEVEL LAPSE RATES.
A WEAK AREA OF COOLER HIGH PRESSURE WILL BUILD BEHIND THE FRONT
THURSDAY AND TEMPS SHOULD SETTLE BACK IN TO THE 90S AFTER HIGHS
AROUND 100 WEDNESDAY. ALL MODELS ARE IN GOOD AGREEMENT THAT A DEEP
DISTURBANCE WILL MOVE THROUGH NRN HIGH PLAINS FRIDAY. THIS SYSTEM
SHOULD PRODUCE STRONG SOUTHWEST WINDS WITH TEMPERATURES RISING TO
OR ABOVE 100F IN MANY AREAS. A POWERFUL COLD FRONT WILL SWEEP
THROUGH FRIDAY NIGHT AND COOL TEMPS BACK INTO THE 80S FOR SATURDAY.
THE ECM HOLDS COOL HIGH PRESSURE INPLACE SUNDAY WHILE THE GFS IS
OFF TO THE RACES DEEPENING LOW PRESSURE ACROSS THE NRN HIGH PLAINS.
THE ECM IS PREFERRED FOR HIGHS IN THE LOWER 90S. BOTH MODELS ARE
SHOWING A STRONG THERMAL RIDGE ACROSS THE HIGH PLAINS MONDAY. THIS
SHOULD EASILY PRODUCE HIGHS IN THE UPPER 90S.
THE UPPER LEVEL RIDGE AND ASSOCIATED SFC HEAT LOW SHOULD REMAIN
ACROSS THE SRN HIGH PLAINS AND MID SOUTH DURING THE NEXT 7 DAYS.
THE ECM IS TRYING TO AMPLIFY THE RIDGE INTO THE CENTRAL PLAINS BY
NEXT MONDAY. RAIN CHANCES ARE GENERALLY CONFINED TO THE NORTH AND
EAST LATE FRIDAY WITH THE APPROACHING COLD FRONT. A WEAK
DISTURBANCE CROSSING ERN WY AND THE BLACK HILLS THURSDAY MAY BE
THE CATALYST FOR ISOLATED STORMS LATE IN THE DAY OR AT NIGHT
ACROSS MUCH OF THE FCST AREA. THE REST OF THE FCST...SATURDAY THROUGH
MONDAY...IS DRY.
BE AWARE THAT THE ONLY REAL HOPE FOR RAINFALL DURING THE NEXT 4
DAYS LIES IN THE FATE OF THE MOISTURE PLUME ACROSS SRN NEB THIS
AFTERNOON. THERE REMAINS A VAST AREA OF VERY DRY AIR AT THE
SURFACE AND LOWER LEVELS OF THE ATM. IN FACT THE WATER VAPOR
PAIRED WITH THE TPW PRODUCT SHOW A TREMENDOUS SURGE OF DRY AIR
FEEDING IN OFF THE PACIFIC THROUGH NEVADA...ID AND MT.
&&
.AVIATION...
18Z TAF ISSUANCE...SHOWERS AND ISOLATED THUNDERSTORMS ARE EXPECTED
TO FORM OVER THE HIGH PLAINS OF COLORADO/WYOMING ONCE AGAIN THIS
AFTERNOON...AND POSSIBLY SPREAD EAST ACROSS PORTIONS OF WESTERN AND
SOUTHWEST NEBRASKA THIS EVENING/TONIGHT. MODEL GUIDANCE INDICATES
THIS ACTIVITY POSSIBLY AS FAR EAST AS KOGA AND KIML BUT GIVEN THAT
THE LOWER LEVELS OF THE ATMOSPHERE REMAIN DRY...VISIBILITY AND/OR
CIGS RESTRICTIONS ARE NOT ANTICIPATED. THE MAIN THREAT FROM ANY
STORM THAT DEVELOPS WILL BE GUSTY ERRATIC WIND. OTHERWISE...WIND
SPEEDS WILL REMAIN LIGHT AND VARIABLE THROUGH MID MORNING TOMORROW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/EXTENDED...JACOBS/CDC
AVIATION...JACOBS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
109 PM EDT MON JUL 30 2012
.SYNOPSIS...
HIGH PRESSURE WILL DRIFT EAST TO OFF THE MID ATLANTIC COAST THIS
EVENING. RETURN SOUTHEAST FLOW AROUND THE HIGH WILL BRING
INCREASING MOISTURE INTO TONIGHT. AN UPPER LEVEL TROUGH OF LOW
PRESSURE WILL THEN RESIDE OVER THE EASTERN UNITED
STATES...YIELDING THE POTENTIAL FOR UNSETTLED WEATHER INTO MID WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 925 AM EDT MONDAY...
ISOLATED SHOWERS CONTINUE TO LINGER ALONG THE EASTERN SLOPES AIDED
BY WEAK SE FLOW INTO THE BLUE RIDGE AND LOW LEVEL THETA-E GRADIENT
PARKED ALONG RIDGES. HOWEVER MORNING RAOBS SHOW THAT THE MOISTURE
REMAINS QUITE SHALLOW IN THE ZONE OF EASTERLY FLOW...CAPPED BY VERY
DRY AIR ALOFT WITH ONLY VERY WEAK MID LEVEL STEERING. THIS
SUPPORTS ADDED SLOW MOVING HEAVY RAIN PRODUCING SHRA/TSRA BUT
EXPECT COVERAGE TO BE LIMITED SOMEWHAT BY LACK OF MUCH SUPPORT
GIVEN PASSAGE OF ONE S/W ATTM AND ONLY FAINT ENERGY SPILLING IN
FROM THE WEST THIS AFTERNOON. LATEST FORECAST SOUNDINGS DO SHOW
THE CAP SLOWLY ERODING OVER THE WEST LATER ON WITH MOST LOCAL
MODELS AS WELL AS THE HRRR PRODUCING A SCATTERING OF CONVECTION
MAINLY MOUNTAINS. THUS BUMPED UP POPS SOME ACROSS THE WEST ESPCLY
BLUE RIDGE TO INIT AND INCLUDED A BRIEF HEAVY RAIN MENTION FOR
SLOW MOVING STORMS. ANY SVR SHOULD BE ISOLATED AND MAINLY WHERE
HELPED BY PRECIP LOADING PER HIGH WINDEX/DCAPE VALUES OFF MODIFIED
RAOBS. OTRW MAINLY PC WITH PLENTY OF CU AROUND AS MOISTURE SLOWLY
RETURNS. MORNING THICKNESS SUPPORTING HIGHS MOSTLY IN THE 80S BUT
MAYBE NOT QUITE AS WARM IN SPOTS SO TWEAKED DOWN RANGES A BIT.
PREVIOUS DISCUSSION AS OF 725 AM EDT MONDAY...
SHORTWAVE MOVING ACROSS ERN TN ATTM...WITH EASTERLY FLOW INTO THE
MTNS STILL KEEPING SHOWERS/FEW TSRA GOING FROM SOUTH OF ROANOKE TO
JUST SOUTH OF THE VA BORDER ALONG ROCKINGHAM/STOKES COUNTY LINE.
WILL SEE THE ACTIVITY CONTINUE UNTIL SHORTWAVE INFLUENCE
PASSES...ALTHOUGH WINDOW WILL BE SHORT AS ANOTHER SHORTWAVE HEADS
INTO THE COALFIELDS OF ERN KY BY 18Z TODAY. ADJUSTED POPS TO
ACCOUNT FOR THIS AND UPPED TEMPS THIS MORNING AS MORE CLOUD COVER
HAS KEPT TEMPS IN THE MID 60S TO AROUND 70.
PREVIOUS VALID DISCUSSION...
SHORTWAVE SINKS SOUTHEAST INTO GA/SC BY MIDDAY AND SHOULD TAKE
MOST OF THE HIGH CLOUDS WITH IT. ANOTHER WAVE PUSHES EAST OUT OF
THE OHIO VALLEY INTO THE BLUE RIDGE THIS AFTERNOON AND WITH UPPER
TROUGH OVERHEAD WITH UPPER DIVERGENCE AHEAD OF 80 KNOT
JET...SHOULD SEE ENOUGH LIFT TO INDUCE SCATTERED STORMS AFTER
MIDDAY. THE 00Z GFS/12Z ECMWF SEEM TO BE IN THE SAME CAMP IN
REGARDS TO THE UPPER LEVEL FEATURES AND TRY TO AIM THE BEST
COVERAGE OF SHOWERS AND STORMS FROM THE ALLEGHANY HIGHLANDS/WV
MTNS SOUTHEAST ALONG THE BLUE RIDGE. KEPT HIGHER POPS HERE WITH A
LESSER THREAT OVER THE PIEDMONT OF NC. WITH FLOW IN THE LOWEST
5KFT EAST TO SOUTHEAST AND WEST TO NW FLOW ALOFT SOME OF THESE
STORMS THAT FORM COULD BE ANCHORED TO THE RIDGES...RESULTING IN
POTENTIALLY HEAVIER RAIN AND POSSIBLE ISOLATED FLOODING...ALTHOUGH
PWATS ARE NOT AS HIGH AS A FEW DAYS AGO RANGING FROM 1 TO 1.4
INCHES.
TONIGHT...ONE SHORTWAVE EXITS WITH THE NEXT UPSTREAM WAVE MOVING
TOWARD THE TN VALLEY INTO THE SRN APPALACHIANS. GFS/ECMWF/SREF
LINGER THE CHANCES OF SHRA/TSRA ACROSS THE AREA THROUGH THE NIGHT
MAINLY ALONG EITHER SIDE OF THE BLUE RIDGE WHERE BEST CONVERGENCE
LIES. LOWERED POPS TO 30 AROUND THE BLUE RIDGE WITH SLIGHT CHANCE
EITHER SIDE.
FOR TEMPS...TODAY WILL SEE INCREASING HUMIDITY IN THE EAST PER SE
FLOW AND WITH CLOUDS FORMING FASTER...THINK MET MOS MAY HAVE BETTER
RESULTS WHICH IS A DEGREE OR THREE COOLER THAN MAV MOS. HIGHS WILL
RANGE FROM NEAR 90 EAST AND IN THE ROA/SRN SHENANDOAH VALLEYS TO
LOWER TO MID 80S WEST.
TONIGHT...THE FLOW IS WEAK AT THE SFC SO THINK LOWS SHOULD BE
SIMILAR TO THIS MORNING WITH 60S CWA WIDE...LOWER IN THE WEST.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
AS OF 340 AM EDT SUNDAY...
WILL START OUT THE DAY TUESDAY WITH THE PERSISTENT UPPER LEVEL
TROUGH DRIFTING SLOWLY TO THE EAST...BUT STILL SITUATED ALMOST
DIRECTLY OVER OUR AREA. THE SUBTLE UPPER DISTURBANCES RIDING INTO
THE BASE OF THE TROUGH FROM THE MIDWEST WILL TRIGGER ANOTHER ROUND
OF SCATTERED THUNDERSTORM ACTIVITY...INITIALLY DEVELOPING OVER THE
MOUNTAINS WITH SUPPORT FROM CONVERGENCE ALONG THE RIDGELINES...BUT
THEN SPREADING INTO THE PIEDMONTS AS AFTERNOON HEATING MAXIMIZES. AS
HAS BEEN TYPICAL OVER THE PAST SEVERAL WEEKS...A FEW OF THESE STORMS
WILL BECOME SEVERE...LIKELY WITHIN MINUTES OF DEVELOPING...WITH
DAMAGING WINDS AS THE GREATEST THREAT. PERIODS OF HEAVY RAIN...WITH
2 TO 3 INCH AMOUNTS LOCALLY...WILL ALSO POSSIBLE IN THE SLOWER
MOVING STORMS.
COME WEDNESDAY...THE WEATHER PATTERN REMAINS SIMILAR...WITH THE
UPPER TROUGH SHIFTING MORE TOWARDS THE COASTAL PLAIN...BUT ALSO
BECOMING MORE BROADENED BY EVENING. WE WILL ALSO SEE A COLD FRONT
MAKE ITS WAY SOUTHWARD FROM THE GREAT LAKES REGION INTO THE OHIO
RIVER VALLEY. IMPACTS FOR OUR AREA REMAIN RELATIVELY UNCHANGED...
WITH SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. WITH THE TROUGH
BECOMING LESS PRONOUNCED ACROSS OUR AREA...AFTERNOON TEMPERATURES
WILL ALSO BE TWO OR THREE DEGREES WARMER THAN THOSE FORECAST FOR
TUESDAY.
ON THURSDAY...THE UPPER TROUGH REALLY BREAKS DOWN...AND RIDGING FROM
THE SOUTHWEST BEGINS TO BUILD INTO OUR AREA. THIS RIDGING WILL WARM
THE MID AND UPPER LEVELS OF THE ATMOSPHERE...HELPING TO LIMIT THE
DEVELOPMENT OF THUNDERSTORMS DURING THE AFTERNOON AND EVENING...
ALTHOUGH WE WILL STILL SEE A FEW. FORECAST MODELS ARE ALSO IN
AGREEMENT THAT THE COLD FRONT WILL STALL SOMEWHERE BETWEEN THE OHIO
RIVER VALLEY AND THE VIRGINIA/NORTH CAROLINA STATE LINE...ALTHOUGH
ITS HARD TO BE MORE SPECIFIC AT THIS POINT BECAUSE THE BOUNDARY
BECOMES SO DIFFUSE. AT ANY RATE...UPPER RIDGING WILL ALSO SUPPORT A
CONTINUED WARMUP FOR OUR AREA...WITH MID AND UPPER 80S EXPECTED FOR
THE MOUNTAINS...AND UPPER 80S TO LOW 90S FOR THE PIEDMONTS.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
AS OF 330 PM EDT SUNDAY...
THE UPPER TROUGH BEGINS TO LIFT OUT AS HEIGHTS INCREASE WITH THE
HEARTLAND RIDGE AND THE BERMUDA HIGH JOINING FORCES. THIS WILL
ALLOW THE TEMPERATURE AND DEWPOINT TO CLIMB TOWARDS UNCOMFORTABLE
LEVELS AGAIN INTO NEXT WEEKEND. INITIALLY POP UP STORMS CAN BE
EXPECTED WITH INCREASING INSTABILITY...THEN A BETTER CHANCE OF
THUNDERSTORMS EXISTS AT THE END OF THE FORECAST WITH ANOTHER COLD
FRONT DROPPING OUT OF THE OHIO VALLEY AND GREAT LAKES.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1245 PM EDT MONDAY...
WIDELY SCATTERED...SLOW MOVING SHOWERS AND STORMS...WILL CONTINUE
TO POP UP AND MOVE LITTLE THROUGH EARLY THIS EVENING RESULTING IN
POCKETS OF HEAVY RAINFALL IN A FEW SPOTS. STILL IFFY AS TO WHETHER
ANY HEAVIER SHRA/TSRA WILL IMPACT ANY OF THE AIRPORTS...SO
INCLUDING A VCTS OR VCSH MENTION UNLESS CONVECTION IS NEAR A TAF
SITE AT RELEASE WHICH WOULD WARRANT MORE PREVAILING LOWER
CONDITIONS. OTRW RUNNING WITH MAINLY VFR 4-6K FT CIGS THIS
AFTERNOON OUTSIDE OF CONVECTION WITH CB BUILDUPS ALONG THE BLUE
RIDGE.
STORMS FADE SOME EARLY THIS EVENING BUT MAY TEND TO REGENERATE
ALONG THE BLUE RIDGE WHERE LOW LEVEL EASTERLY FLOW WILL PERSIST
AHEAD OF ANOTHER WEAK MID LEVEL WAVE CROSSING FROM THE WEST
OVERNIGHT. THEREFORE INCLUDED A VCSH MENTION AT A FEW
LOCATIONS...MAINLY KROA/KBCB WHERE GUIDANCE SHOWS A SWATH OF SHRA
LINGERING PAST MIDNIGHT. ALSO ADDED SOME LOWER MVFR CIGS IN SPOTS
WHILE KEEPING FOG AT IFR LEVELS AT LWB/BCB...AND MVFR OUT EAST AS
WELL AS KBLF WHERE CONFIDENCE IN FOG/STRATUS REMAINS LOW.
LOW CIGS AND FOG SHOULD SLOWLY BURN AWAY TUESDAY MORNING BUT MAY
TAKE UNTIL LATE MORNING FOR A RETURN TO VFR IN THE VALLEY
LOCATIONS. HOWEVER ANY HEATING WILL AGAIN RESULT IN BKN CU FIELDS
BY MIDDAY WITH YET ANOTHER WAVE TO THE SOUTH BRINGING AN EVEN
BETTER COVERAGE OF SHRA/TSRA FOR THE AFTERNOON AND EVENING ON
TUESDAY.
THE DAILY AFTERNOON AND EVENING THREAT OF SHOWERS AND
THUNDERSTORMS CONTINUES THROUGH THE WEEK BUT SHOULD BECOME MORE
ISOLATED FROM MIDWEEK ON AS WEAK HIGH PRESSURE SETTLES IN FROM
THE WEST BY WEEKS END. OUTSIDE OF THIS MAINLY DIURNALLY DRIVEN
CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE FROM
OVERNIGHT VALLEY FOG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/PM/WP
NEAR TERM...JH/WP
SHORT TERM...NF
LONG TERM...KM
AVIATION...JH/WP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
247 PM CDT MON JUL 30 2012
.SHORT TERM...TONIGHT THROUGH THURSDAY
247 PM CDT MON JUL 30 2012
MAIN FORECAST CONCERNS ARE ON SHOWER AND THUNDERSTORM CHANCES THIS
EVENING. FOCUS THEN TURNS TO VALLEY FOG POTENTIAL TONIGHT AND AGAIN
WEDNESDAY NIGHT AND SHOWER/THUNDERSTORM CHANCES WEDNESDAY NIGHT
INTO THURSDAY.
LATEST SURFACE OBSERVATIONS SHOWED A COLD FRONT EXTENDING FROM
IRONWOOD MICHIGAN...TO NEAR RICE LAKE WISCONSIN...TO NEAR ST.
JAMES MINNESOTA...DRIFTING SOUTHEAST. MESOSCALE FORECAST MODELS
CONTINUE TO SUGGEST THAT SHOWERS AND THUNDERSTORMS WILL FIRE ALONG
THIS FRONT IN THE 4 TO 6 PM TIME FRAME. THIS WOULD PUT THE FRONT
OVER CENTRAL WISCONSIN...EXTENDING SOUTHWEST INTO NORTHEAST IOWA.
LATEST VISIBLE SATELLITE IMAGERY SHOWED A WELL DEFINED CUMULUS
FIELD AHEAD OF THE FRONT. NO PRECIPITATION RETURNS ON RADAR YET
ALONG THIS FIELD. THINKING THE FRONT WILL FINALLY GENERATE
CONVECTION AS IT MOVES INTO CENTRAL AND FAR SOUTHWEST
WISCONSIN...EXTENDING INTO NORTHEAST IOWA. DRY LOW LEVELS WILL LEAD
TO THE POTENTIAL FOR DAMAGING WINDS WITH ANY STORMS THAT DEVELOP.
LATEST RAP ANALYSIS INDICATES NEARLY 1400-1600 DOWNDRAFT CAPE
AHEAD OF THE COLD FRONT. 0-6 KM SHEAR IS RATHER WEAK...GENERALLY
LESS THAN 30 KTS...SO STORMS MAY STRUGGLE TO BECOME ORGANIZED ONCE
THEY DEVELOP. SURFACE BASED CAPE VALUES OF NEARLY 4000 J/KG WILL
LEAD TO STRONG UPDRAFTS...WITH MARGINALLY SEVERE HAIL POSSIBLE.
THE COLD FRONT WILL PUSH EAST OF THE FORECAST AREA LATE THIS EVENING
WITH HIGH PRESSURE BUILDING INTO THE REGION. FORECAST SOUNDINGS ARE
SHOWING THE POTENTIAL FOR SOME VALLEY FOG DEVELOPMENT ALONG THE
MISSISSIPPI RIVER. THE AIR MASS LOOKS A BIT ON THE DRY SIDE FOR THIS
TO OCCUR. TEMPERATURE AND DEW POINT SPREADS AT KLSE APPROACH TWO
DEGREES BUT THIS OCCURS LATE IN THE NIGHT/EARLY MORNING...AROUND
11Z. WINDS ARE MORE FAVORABLE...WITH LIGHT WIND FROM THE SURFACE
THROUGH 2 KFT. THINKING A BRIEF PERIOD OF PATCHY VALLEY FOG IS
POSSIBLE TONIGHT...ESPECIALLY IF ANY PRECIPITATION FALLS THIS
EVENING. ANOTHER FACTOR POSSIBLY WORKING AGAINST VALLEY FOG IS A LOW
CLOUD DECK APPROACHING THE FORECAST AREA BEHIND THE COLD FRONT.
THESE CLOUDS LOOK TO PASS JUST EAST OF THE MISSISSIPPI SO WILL HAVE
TO KEEP A CLOSE WATCH ON THESE. OTHERWISE...PLAN ON SKIES RANGING
FROM MOSTLY CLEAR TO PARTLY CLOUD DURING THE OVERNIGHT HORUS. LOOK
FOR LOW TEMPERATURES WILL RANG FROM LOWER 60S ACROSS NORTHERN
WISCONSIN TO THE UPPER 60 OVER NORTHEAST IOWA.
SLIGHTLY COOLER AIR WILL MOVE INTO THE REGION BEHIND THE FRONT LATE
TONIGHT INTO TUESDAY. 850 MB TEMPERATURES WILL FALL FROM 22C MONDAY
AFTERNOON INTO THE 14 TO 16 C RANGE BY EARLY TUESDAY MORNING. HIGH
PRESSURE WILL BE IN CONTROL THROUGH THE DAY ON TUESDAY PROVIDING
MOSTLY SUNNY SKIES. PLAN ON HIGHS RANGING FROM THE LOWER 80S ACROSS
NORTHERN WISCONSIN TO THE UPPER 80S OVER NORTHEAST IOWA.
HIGH PRESSURE IS EXPECTED TO SLIDE EAST OF THE FORECAST AREA TUESDAY
NIGHT INTO WEDNESDAY MORNING AS ANOTHER COLD FRONT APPROACHES FROM
WESTERN MINNESOTA AND EAST SOUTH DAKOTA. FORECAST SOUNDINGS AGAIN
SHOW THE POTENTIAL FOR SOME VALLEY FOG. HIGH PRESSURE WILL BE
SETTLED OVER THE AREA DURING THE OVERNIGHT HOURS PROVIDING LIGHT AND
VARIABLE WINDS. TEMPERATURE/DEW POINT SPREADS APPROACH TWO DEGREES
BY 09Z. WILL HAVE TO KEEP A CLOSE WATCH ON SOME HIGH CLOUDS TRYING
TO STREAM IN FROM THE WEST. CURRENT THINKING IS THAT AREAS OF FOG
WILL DEVELOP ALONG THE MISSISSIPPI AND WISCONSIN RIVER VALLEY.
FORECAST MODELS ARE SHOWING VERY DRY AIR ADVECTING INTO THE AREA
AHEAD OF THE APPROACHING FRONT. WINDS WILL SHIFT TO THE SOUTHWEST
BY WEDNESDAY AFTERNOON AS THE FRONT APPROACHES. DEW POINTS PLUMMET
AS THIS OCCURS...ESPECIALLY ACROSS NORTHEAST IOWA...PORTIONS OF
SOUTHEAST MINNESOTA AND SOUTHWEST WISCONSIN. COULD SEE DEW POINTS
FALL INTO THE MID 40S BY THE MID AFTERNOON HOURS. THE COLD FRONT
IS EXPECTED TO MOVE INTO THE AREA LATE WEDNESDAY AFTERNOON INTO
WEDNESDAY NIGHT AS A SHORTWAVE TROUGH MOVES OVER THE UPPER
MISSISSIPPI RIVER VALLEY. THE FRONT AND SHORTWAVE WILL NOT HAVE
MUCH MOISTURE TO WORK WITH AS THE DRY AIR ADVECTS IN FROM THE
SOUTHWEST...WITH A FAIRLY DEEP ELEVATED MIXED LAYER IN PLACE.
EXPECT TO SEE SOME SHOWERS AND ISOLATED THUNDERSTORMS AS THIS
FEATURE MOVES THROUGH. RATHER HIGH BASED ACTIVITY WITH CLOUD BASES
IN THE 8 TO 10KFT RANGE. GUSTY WINDS WOULD BE A CONCERN WITH ANY
SHOWER/STORM ACTIVITY THAT DEVELOPS. ANOTHER SHORTWAVE IS
EXPECTED TO MOVE OVER THE REGION DURING THE DAY ON THURSDAY.
AGAIN THE ELEVATED MIXED LAYER AND CAPPING WILL BE A FACTOR. 0-3KM
MUCAPE WILL CLIMB TO AROUND 2000 J/KG THURSDAY AFTERNOON BUT
QUICKLY WANES DURING THE AFTERNOON AS WEAK SURFACE HIGH PRESSURE
ATTEMPTS TO BUILD IN FROM THE EAST. WILL MAINTAIN A CHANCE OF
SHOWERS AND THUNDERSTORMS ON THURSDAY GIVEN THE SHORTWAVE MOVING
THROUGH.
.LONG TERM...FRIDAY THROUGH MONDAY
247 PM CDT MON JUL 30 2012
30.12 MEDIUM RANGE MODELS IN AGREEMENT FRIDAY INTO
SATURDAY...SHOWING A POTENT UPPER LEVEL TROUGH MOVING ACROSS THE
DAKOTAS AND PUSHING INTO THE UPPER MISSISSIPPI RIVER VALLEY. THE
TROUGH IS EXPECTED TO CLOSE INTO AN UPPER LOW OVER EASTERN NORTH
DAKOTA/NORTHERN MINNESOTA DURING THE DAY ON SATURDAY...PUSHING A
COLD FRONT ACROSS THE AREA. GIVEN THE STRONG DYNAMICS OF THIS SYSTEM
AND STRONG MOISTURE RETURN AHEAD OF IT...FOCUSED INTO THE FORECAST
AREA...A SEVERE WEATHER EVENT LOOKS POSSIBLE. TIMING OF THE FRONT
AND ANY MCS ACTIVITY AHEAD OF IT WILL HAVE AN IMPACT ON CONVECTION
OVER THE FORECAST AREA. EXACT DETAILS ARE UNCLEAR AT THIS TIME BUT
WILL HAVE TO KEEP A VERY CLOSE WATCH ON THE NEXT FEW FORECAST MODEL
RUNS. CURRENT THINKING IS THAT THE AREA COULD SEE AN MCS MOVE
THROUGH SATURDAY MORNING...WITH STORMS REDEVELOPING ALONG THE COLD
FRONT SATURDAY AFTERNOON. PLAN ON HIGHS ON FRIDAY RANGING FORM THE
LOWER 80S OVER NORTHERN WISCONSIN TO THE MID 80S ACROSS NORTHEAST
IOWA. LOOK FOR OVERNIGHT LOWS IN THE 60S. SLIGHTLY COOLER AIR WILL
MOVE IN BEHIND THE FRONT ON SUNDAY WITH HIGHS FALLING INTO THE 70S
TO LOWER 80S.
&&
.AVIATION...THROUGH 18Z TUESDAY
1228 PM CDT MON JUL 30 2012
SHORT WAVE TROUGH MOVING SOUTHEAST ACROSS LAKE SUPERIOR INTO THE
GREAT LAKES REGION THIS AFTERNOON/EVENING. TRAILING COLD FRONT
EXPECTED TO PASS BOTH TAF LOCATIONS DURING THE AFTERNOON. AT THIS
TIME...IT APPEARS THE FRONT WILL BE PAST BEFORE THE PEAK HEATING
CAN BREAK THE CONVECTIVE CAP...SO DID NOT INCLUDE ANY SHRA/TSRA IN
THE TAF LOCATIONS. FEEL IF CONVECTION DEVELOPS IT WILL BE SOUTH
AND SOUTHEAST OF THE AIRFIELDS. HOWEVER...THERE IS A BAND OF MVFR
STRATO-CUMULUS SHOWING UP WITH THE FRONT. THIS MAY BRIEFLY DROP
EACH TAF LOCATION TO A MVFR CEILING FOR 60-90 MINUTES. BEHIND THE
FRONT...EXPECT NORTHWEST WINDS TO BE A BIT GUSTY...BUT GUSTS OVER
G20KT ARE NOT ANTICIPATED. ENOUGH OF A NORTH-NORTHWEST BREEZE WILL
OCCUR OVERNIGHT SO THAT FOG WILL NOT BE AN ISSUE...BUT IF WINDS DO
DIE OFF ENOUGH FOR THE ATMOSPHERE TO DECOUPLE THERE COULD BE SOME
LIGHT FOG/MIST WITH 4-6SM VISIBILITY. LATER SHIFTS WILL MONITOR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CDT MON JUL 30 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...MW
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1156 AM CDT MON JUL 30 2012
.UPDATE...
TEMPS AND DEWPOINTS HAVE BEEN MOSTLY ON TRACK SO FAR. MAIN CONCERN
HAS BEEN THUNDERSTORM POTENTIAL AND SEVERE RISK THIS AFTN/EVENING. SHOT
OF WARM AIR IN MIDLEVELS WILL LIMIT CONVECTION THIS
AFTERNOON...BUT 700MB TEMPERATURES FALL A BIT GOING INTO THE
EVENING PARTICULARLY OVER EASTERN CWA. 11Z HRRR DEVELOPS THUNDER
ALONG SURFACE BOUNDARY AROUND 5 PM WHICH SEEMS REASONABLE.
&&
.AVIATION/18Z TAFS/...
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE DAY TUESDAY. ONLY
EXCEPTION WOULD BE THIS EVENING WITH A CHANCE OF THUNDERSTORMS.
CERTAINLY A POSSIBILITY OF IFR TO MVFR VSBYS WITHIN HEAVIER
RAINFALL. MONITORING THE POTENTIAL FOR SEVERE STORMS AS WELL...WITH
LARGE HAIL AND DAMAGING WINDS THE PRIMARY THREATS. WILL PROBABLY
LEAVE VCTS IN TAFS FOR NOW UNTIL CONFIDENCE IN AREAL COVERAGE OF
STORMS INCREASES. BEST CHANCE FOR STORMS STILL SEEMS TO BE IN THE
22Z-03Z RANGE ACROSS SOUTHERN WISCONSIN.
QUIET WEATHER THEN EXPECTED THROUGH TUESDAY AFTER SHOWERS AND STORMS
WIND DOWN LATE THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 344 AM CDT MON JUL 30 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH
MID LEVEL CLOUDS TO GRADUALLY CLEAR TO THE SE THROUGH ABOUT 15Z.
SWLY WINDS AND WARM ADVECTION TO THEN ENSUE AS LOW PRESSURE AND ITS
SHORTWAVE TROUGH ALONG THE MN/CANADIAN BORDER MOVE THROUGH THE NRN
GREAT LAKES TODAY AND TNT. THE 850-700 MB THERMAL RIDGE WILL SETTLE
OVER THE AREA BY LATE AFTERNOON WITH MODEL AVERAGE 925/850MB TEMPS
SUGGESTING LOWER TO MID 90S FOR HIGHS. HEAT INDEX VALUES WILL BE
SLIGHTLY HIGHER BUT ANY 100 DEGREE READINGS SHOULD BE BRIEF AND
ISOLATED. THE SWLY WINDS WILL KEEP THE LAKE BREEZE CLOSE TO THE LAKE
TODAY.
A WEAK COLD FRONT WILL THEN APPROACH CENTRAL WI TOWARD 00Z AND
SLOWLY PROGRESS ACROSS SRN WI TNT. LOW TO MID LEVEL Q-VECTORS AND
FRONTOGENESIS/CONVERGENCE DO SHOW SOME LIFT WHILE THE AREA WILL BE
AIDED ALOFT BY SOME DIFFERENTIAL PVA FROM THE SHORTWAVE TROUGH
MOVING ACROSS THE NRN GREAT LAKES. MLCAPE/MUCAPE VALUES WILL RANGE
FROM 1500-2500 J/KG IN AN ENVIRONMENT OF 35 KTS OF DEEP LAYER SHEAR
AND HELICITIES SUFFICIENT FOR SUPERCELLS. THUS INCREASED POPS TO
30-50 PERCENT WITH BEST CHANCES TOWARD EAST CENTRAL WI WHERE SCT
TSTORMS WILL OCCUR CLOSER TO MAXIMUM HEATING DURING THE EARLY
EVENING WHILE THEY WILL OCCUR MORE TOWARD MID TO LATE EVENING
FARTHER SOUTH. SVR THREAT WILL THUS BE A LITTLE HIGHER TOWARD EAST
CENTRAL WI WITH PRIMARY THREATS OF DAMAGAGING WINDS AND LARGE HAIL.
HIGH LCL HTS OF 6-7 KFT SHOULD LIMIT THE TORNADO THREAT.
SHORT TERM...TUESDAY THROUGH WEDNESDAY NIGHT...FORECAST
CONFIDENCE IS MEDIUM.
SHORT TERM MODELS INDICATING NORTHWEST FLOW IN THE MIDDLE TO
UPPER LEVELS LINGERING ACROSS THE REGION DURING THIS PERIOD. COLD
FRONT SHIFTS SOUTHEAST OF THE AREA TUESDAY MORNING...WITH THE
PASSING SHORTWAVE TROUGH CLEARING THE AREA BY 18Z TUESDAY. MAY SEE
SOME LINGERING CLOUDS BEFORE THE SHORTWAVE CLEARS THE AREA IN THE
MORNING.
OTHERWISE...NAM/GFS BRING HIGH PRESSURE SLOWLY SOUTHEAST ACROSS
THE REGION TUESDAY THROUGH WEDNESDAY. THIS FEATURE SHOULD BRING
QUIET WEATHER TO THE AREA. LIGHT WINDS AND MOSTLY CLEAR SKIES
TUESDAY NIGHT WITH LOWER 60S DEWPOINTS SHOULD BRING PATCHY FOG TO
LOW LYING AREAS.
NAM 925MB TEMPERATURES REMAIN IN THE MID 20S CELSIUS RANGE
TUESDAY AND WEDNESDAY...WHICH SHOULD RESULT IN HIGHS IN THE UPPER
80S TO LOWER 90S EACH DAY. ONSHORE WINDS WILL BRING SOMEWHAT
COOLER TEMPERATURES NEAR LAKE MICHIGAN.
NAM/GFS INDICATING WARM AIR ADVECTION ACROSS THE AREA WEDNESDAY
AFTERNOON AND WEDNESDAY NIGHT. SHORTWAVE TROUGH ALSO APPROACHES
THE AREA FROM THE WEST LATE WEDNESDAY NIGHT. SURFACE COLD FRONT
SLOW TO SHIFT SOUTHEAST ACROSS NORTHERN WISCONSIN WEDNESDAY NIGHT.
AREA FORECAST SOUNDINGS FROM NAM/GFS SHOWING SOME MID LEVEL
MOISTURE WEDNESDAY NIGHT WITH WEAK ELEVATED CAPE. KEPT LOW CHANCE
POPS FOR NOW FOR WEDNESDAY NIGHT.
LONG TERM...THURSDAY THROUGH SUNDAY...FORECAST CONFIDENCE IS
MEDIUM.
ECMWF/GFS SHOWING MID TO UPPER LEVEL HIGH OVER WESTERN TEXAS TO
CONTINUE TO FLATTEN OUT THURSDAY AND FRIDAY...ALLOWING MORE ZONAL
FLOW OVER THE WESTERN GREAT LAKES REGION. THIS ALLOWS A WELL
DEFINED SHORTWAVE TROUGH TO SHIFT EAST ACROSS THE DAKOTAS
FRIDAY/FRIDAY NIGHT...AND ACROSS MINNESOTA AND NORTHERN WISCONSIN
SATURDAY/SATURDAY NIGHT. THE GFS IS QUICKER AND NOT AS DEEP WITH
THE SHORTWAVE AS THE ECMWF.
AT THE SURFACE...ECMWF/GFS BRINGS COLD FRONT SOUTH THROUGH THE
AREA WITH SOME QPF LATE THURSDAY INTO THURSDAY NIGHT. THEY THEN
TRY TO BRING A BRIEF DRY PERIOD TO THE AREA FRIDAY. USED CONSENSUS
BLEND WITH POPS AND TEMPERATURES FOR THURSDAY THROUGH FRIDAY GIVEN
SOME DIFFERENCES WITH TIMING OF FEATURES. TEMPERATURES SHOULD
REMAIN NEAR TO SLIGHTLY ABOVE NORMAL.
BOTH MODELS THEN IN GENERAL AGREEMENT WITH STRONG COLD FRONT
SHIFTING EAST THROUGH THE REGION SATURDAY. GIVEN THE STRENGTH OF
THE SHORTWAVE TROUGH MOVING THROUGH THE REGION...THIS SHOULD BE
THE NEXT GOOD SHOT OF PRECIPITATION ACROSS THE AREA. KEPT CHANCE
POPS GOING FOR FRIDAY NIGHT THROUGH SATURDAY NIGHT...WITH DRIER
CONDITIONS RETURNING SUNDAY. GFS ALSO SHOWING GOOD DEEP LAYER
SHEAR THOUGH IS OVERDONE WITH MEAN LAYER CAPE. SEVERE WEATHER
WOULD NOT BE OUT OF THE QUESTION WITH THIS SYSTEM. STILL FAR
OFF...SO WILL SEE HOW THIS SYSTEM DEVELOPS OVER THE NEXT SEVERAL
DAYS. NEAR NORMAL TEMPERATURES ARE EXPECTED.
AVIATION/12Z TAFS/...
BKN MID LEVEL DECK WILL GRADUALLY CLEAR BY MID TO LATE MORNING
HOURS. ONLY A FEW CUMULUS WILL DEVELOP FOR MUCH OF THE DAY WITH
SCT-BKN050-070 DEVELOPING FOR THE EVENING AS A COLD FRONT AND
SCATTERED TSTORMS MOVE THROUGH THE REGION. SKIES WILL CLEAR TOWARD
SUNRISE FOR TUE. VFR CONDITIONS WILL PREVAIL BUT REDUCED CIGS AND
VSBYS WITHIN TSTORMS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...WIMBERLEY/DDV
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
TUESDAY THROUGH SUNDAY...WOOD