Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/13/12
AREA FORECAST DISCUSSION
NWS NEW YORK NY
822 AM EDT SAT AUG 11 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE TOWARDS THE REGION TODAY WITH A
LOW DEVELOPING ALONG IT TONIGHT AS IT WEAKENS IN THE REGION. THE
FRONT MOVES ACROSS THE WHOLE REGION BY SUNDAY EVENING. HIGH
PRESSURE BUILDS INTO THE REGION FOR THE START OF THE NEW
WEEK...THEN UNSETTLED WEATHER RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TEMPS AND DEWPOINTS ON TRACK. ADJUSTED POPS A FEW HOURS LATER
COMPARING TO RECENT RADAR REFLECTIVITY TRENDS. NOTING HRRR FORECAST
REFLECTIVITY FIELDS ARE AGGRESSIVE IN BRINGING IN AND DEVELOPING
ACROSS THE AREA WITH MORE SHOWERS THIS MORNING.
EQUIVALENT BAROTROPIC STRUCTURE TO LOW NEAR LAKE HURON. THIS LOW
SLOWLY WEAKENS AND MOVES NORTH...FARTHER AWAY FROM ITS ASSOCIATED
FRONTAL SYSTEM TO THE SOUTH AND EAST. THE TIMING REPRESENTS A SLOWER
TIMING OF THE FRONTAL MOVEMENT.
THE AREA STAYS IN THE WARM SECTOR THROUGH THE DAY WITH EASTERN
SECTIONS CLOSER TO LOW LEVEL JET DEVELOPMENT ASSOCIATED WITH
SECONDARY CYCLOGENESIS NEAR DELMARVA. A COLD FRONT AT THE SURFACE
SLOWLY APPROACHES FROM THE WEST AND MOVES INTO THE AREA...WEAKENING
AS IT DOES SO. THERE WILL BE EMBEDDED SHORTWAVES MOVING THROUGH
ALOFT ON A SSW SYNOPTIC FLOW WITH THE LOCAL REGION NEAR THE SOUTHERN
END OF A REGION OF DECENT MID LEVEL Q VECTOR CONVERGENCE. PW VALUES
REMAIN IN GENERAL 1.8 TO 2 INCH RANGE FOR CITY AND EASTERN
SECTIONS WITH DEEP TROPICAL SYNOPTIC FLOW. NORTH AND WEST OF THE
CITY...THERE ARE SIGNS SOME DRIER AIR WILL TRY TO WORK INTO THE
ATMOSPHERE...ALLOWING FOR PW VALUES TO DROP A FEW TENTHS OF AN
INCH BY THE END OF THE AFTERNOON INTO THE EVENING.
2/3 MET AND 1/3 MAV FOR MAX TEMPS TODAY. GREATER WEIGHT WITH COOLER
GUIDANCE WITH ABUNDANT CLOUDS AND HIGHER POPS EXPECTED. ANY SHOWERS
AND THUNDERSTORM COULD PRODUCE HEAVY DOWNPOURS AS WELL AS GUSTY
WINDS WITH BULK SHEAR 0-6KM OF AROUND 30 KT. TRAINING OF CELLS IS
PROBABLE WITH PARALLEL FLOW FROM TO LOW TO UPPER LEVELS.
THERE IS A HIGH RISK FOR RIP CURRENTS AT ATLANTIC OCEAN BEACHES THIS
AFTERNOON AND EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLD FRONT WILL BE MOVING THROUGH BY LATE SUNDAY AFTERNOON AT
LEAST ACROSS THE WESTERN HALF OF THE CWA. AGAIN...A SLOWER TIMING
OF THE FRONT HAS BEEN CONVEYED BY MUCH OF THE NUMERICAL GUIDANCE.
POPS INCREASED FROM PREVIOUS FORECAST WITH SOME LINGERING SHOWERS
AND THUNDERSTORMS TONIGHT. THE COVERAGE WILL BE HIGHEST OUT
EAST...WHERE BETTER DYNAMICS WILL BE. AGAIN WITH PW VALUES HIGH
AND BULK SHEAR O-6 KM NEAR 30-35 KT...THUNDERSTORMS WILL BE
CAPABLE OF PRODUCING GUSTY WINDS AND TORRENTIAL RAIN. THE JET
STREAK COMES THROUGH TONIGHT AS WELL AND THE REGION WILL BE IN THE
RIGHT REAR QUAD WHICH COULD LEAD TO FURTHER WESTWARD EXPANSION OF
THE HIGHER COVERAGE OF SHOWERS AND THUNDERSTORMS TONIGHT. CURRENT
THINKING STILL HAS THIS HIGHER COVERAGE MOSTLY OVER EASTERN LONG
ISLAND AND SOUTHEAST CONNECTICUT WHERE MORE INSTABILITY WILL BE.
BLEND OF MET...MAV...AND NAM12 SFC TEMPS FOR MIN TEMPS TONIGHT
WITHOUT MUCH DIURNAL TEMP RANGE EXPECTED. SOUTHERLY FLOW WILL BE STILL
IN PLACE. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE COLD FRONT
WHICH WILL BE MOVING INTO THE REGION.
2/3 MAV AND 1/3 MET FOR MAX TEMPS ON SUN. AGAIN...THIS IS FAVORING
THE COOLER GUIDANCE. IT DOES APPEAR THIS WILL BE A WARMER DAY FOR
WESTERN SECTIONS AS DRIER AIR MOVES FARTHER EAST IN THE AFTERNOON
HOURS BEHIND THE COLD FRONT. POPS FOR SHOWERS DIMINISH AS WELL FROM
WEST TO EAST. THUNDERSTORMS WILL BE MORE ISOLATED GIVEN THE LOWER
CAPE ACROSS THE REGION OF LESS THAN 1000 J/KG FOR MOST LOCATIONS.
FOR MONDAY....COLD FRONT EAST OF REGION AND MORE STABLE AIR IN
PLACE AS HIGH PRESSURE BUILDS IN. WARMER TEMPS EXPECTED WITH WARMER
MET GUIDANCE CHOSEN. FLOW AT SFC TURNS MORE WESTERLY WITH DRIER
AIR WORKING ITS WAY IN...HELPING INCREASE DIURNAL WARMTH. MAV/MET
BLEND USED FOR MIN TEMPS MONDAY NIGHT WITH NEAR NORMAL TEMPS
EXPECTED AS HIGH PRESSURE MOVES OFFSHORE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
WITH THE HIGH MOVING OFFSHORE MONDAY NIGHT AND LOW PRES TRACKING
THROUGH THE GREAT LAKES AND OHIO VALLEY...A WARM FRONT WILL LIFT
NORTH INTO THE REGION MONDAY NIGHT/TUESDAY MORNING. SOME
SHOWERS/THUNDERSTORMS EXPECTED WITH ITS PASSAGE. AS THE LOW TRACKS
INTO EASTERN CANADA...A SECONDARY LOW WILL FORM OVER THE DELMARVA
AREA ON TUESDAY...AND THIS SYSTEM WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH WEDNESDAY.
WEAK HIGH PRES WILL MOVE THROUGH THE REGION THURSDAY...THEN
ANOTHER SYSTEM WILL IMPACT THE AREA LATE IN THE WEEK. THERE ARE
INCONSISTENCIES AMONG THE MODELS...RESULTING IN A LOW CONFIDENCE
FORECAST FOR THE LONG TERM PERIOD. HPC GUIDANCE WAS CLOSELY
FOLLOWED AS A RESULT.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT SLOWLY APPROACHES FROM THE WEST THROUGH SUNDAY.
LOW CONFIDENCE FORECAST ON TIMING OF CONVECTION AND STRATUS/FOG
TONIGHT. MVFR TO IFR CONDS EARLY WILL LIFT TO VFR BY AROUND 14Z.
EXCEPTION IS KGON WHO MAY HOLD ON TO MVFR CIGS FOR MOST OF THE
DAY.
DUE TO LACK OF SHOWER/TSTM ACTIVITY TO THE SW THIS MORNING...AM
NOW THINKING CONVECTION WILL BE CONFINED TO THE AFTN HOURS. TIMING
OF 16Z-19Z MAY STILL BE TOO EARLY...BUT INSTABILITY IS ALREADY
PRESENT ACROSS THE AREA SO IT MAY NOT TAKE LONG FOR STORMS TO
DEVELOP. CONDS WILL LIKELY VARY FROM VFR TO MVFR/IFR IN
CONVECTION.
WINDS MAY VARY AND BE +/- 20-30 DEGREES OF CURRENT
FORECAST...ESPECIALLY THIS MORNING.
AS FRONT INCHES CLOSER TO THE AREA TONIGHT...SHOWERS/TSTMS WILL
REMAIN A THREAT...BUT COVERAGE WILL DECREASE AND THEREFORE
CONFIDENCE NOT HIGH ENOUGH TO INCLUDE AT THIS TIME. AREAS OF MVFR
TO IFR IN FOG/STRATUS POSSIBLE AGAIN TONIGHT.
OUTLOOK FOR 12Z SUNDAY THROUGH WEDNESDAY...
.SUN... MVFR TO IFR IN THE MORNING. SCT SHOWERS/TSTMS MAINLY E OF
NYC TERMINALS.
.SUN NIGHT-TUE MORN...VFR.
.TUE AFTN-WED...SCT SHOWERS AND TSTMS.
&&
.MARINE...
WEAK SFC TROUGH/WARM FRONTAL BOUNDARY LIFTS N OF THE WATERS LATER THIS
MORNING/AFTN. MEANWHILE...A COLD FRONT AND WAVE OF LOW PRES WILL
APPROACH FROM THE WEST AND SLOWLY MOVE ACROSS THE AREA SUN AND SUN
NIGHT.
TIGHTENING PRES GRADIENT TODAY WITH SLY WINDS 10-20 KT ON THE
WATERS...HIGHEST ON THE OCEAN. GUSTS ON THE OCEAN WATERS MAY FALL
SHORT OF ADVSY LEVELS THIS AFTN...BUT SEAS WILL REMAIN BETWEEN 5 AND
7 FT THROUGH TONIGHT. SCA REMAINS IN PLACE AS A RESULT. MARGINAL
SEAS MAY LINGER INTO SUNDAY MORNING...MAINLY ON EASTERN OCEAN
WATERS...BUT DO NOT HAVE THE CONFIDENCE TO EXTEND INTO THE THIRD
PERIOD AT THIS POINT...ESPECIALLY SINCE WW3 HAS BEEN RUNNING HIGH
ALL SEASON.
HIGH PRES BUILDS IN FOR MONDAY INTO TUE...THEN ANOTHER FRONTAL
SYSTEM WITH UNSETTLED WEATHER RETURNS FOR THE MIDDLE OF THE WEEK.
SUB-ADVSY CONDS ARE EXPECTED DURING THIS TIME.
&&
.HYDROLOGY...
STILL LOOKING AT A HEAVY RAIN THREAT WITH PWATS NEAR 1.8 TO 2 INCHES
FOR TODAY AND TONIGHT...ESPECIALLY FOR EASTERN SECTIONS OF THE
FORECAST REGION. ADDITIONAL RAINFALL TOTALS THROUGH SUNDAY ARE
BASIN AVERAGED FROM 1/2 TO 1 INCH. HIGHER AMOUNTS WILL BE POSSIBLE
UP TO 2 INCHES HERE THOUGH. SIMILAR TO YESTERDAY...MINOR FLOODING
SEEMS TO BE MAIN THREAT WITH ISOLATED FLASH FLOODING POSSIBLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MPS
AVIATION...24
MARINE...24
HYDROLOGY...JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
419 AM EDT SAT AUG 11 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT WILL MOVE TOWARDS THE REGION TODAY WITH A
LOW DEVELOPING ALONG IT TONIGHT AS IT WEAKENS IN THE REGION. THE
FRONT MOVES ACROSS THE WHOLE REGION BY SUNDAY EVENING. HIGH
PRESSURE BUILDS INTO THE REGION FOR THE START OF THE NEW
WEEK...THEN UNSETTLED WEATHER RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
EQUIVALENT BAROTROPIC STRUCTURE TO LOW NEAR LAKE HURON. THIS LOW
SLOWLY WEAKENS AND MOVES NORTH...FARTHER AWAY FROM ITS ASSOCIATED
FRONTAL SYSTEM TO THE SOUTH AND EAST. THE TIMING REPRESENTS A SLOWER
TIMING OF THE FRONTAL MOVEMENT.
THE AREA STAYS IN THE WARM SECTOR THROUGH THE DAY WITH EASTERN
SECTIONS CLOSER TO LOW LEVEL JET DEVELOPMENT ASSOCIATED WITH
SECONDARY CYCLOGENESIS NEAR DELMARVA. A COLD FRONT AT THE SURFACE
SLOWLY APPROACHES FROM THE WEST AND MOVES INTO THE AREA...WEAKENING
AS IT DOES SO. THERE WILL BE EMBEDDED SHORTWAVES MOVING THROUGH
ALOFT ON A SSW SYNOPTIC FLOW WITH THE LOCAL REGION NEAR THE SOUTHERN
END OF A REGION OF DECENT MID LEVEL Q VECTOR CONVERGENCE. PW VALUES
REMAIN IN GENERAL 1.8 TO 2 INCH RANGE FOR CITY AND EASTERN SECTIONS.
NORTH AND WEST OF THE CITY...THERE ARE SIGNS SOME DRIER AIR WILL TRY
TO WORK INTO THE ATMOSPHERE...ALLOWING FOR PW VALUES TO DROP A FEW
TENTHS OF AN INCH BY THE END OF THE AFTERNOON INTO THE EVENING.
2/3 MET AND 1/3 MAV FOR MAX TEMPS TODAY. GREATER WEIGHT WITH COOLER
GUIDANCE WITH ABUNDANT CLOUDS AND HIGHER POPS EXPECTED. ANY SHOWERS
AND THUNDERSTORM COULD PRODUCE HEAVY DOWNPOURS AS WELL AS GUSTY
WINDS WITH BULK SHEAR 0-6KM OF AROUND 30 KT.
THERE IS A MODERATE RISK FOR RIP CURRENTS ALONG THE SOUTH SHORE OF
LONG ISLAND THIS AFTERNOON AND EVENING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
COLD FRONT WILL BE MOVING THROUGH BY LATE SUNDAY AFTERNOON AT
LEAST ACROSS THE WESTERN HALF OF THE CWA. AGAIN...A SLOWER TIMING
OF THE FRONT HAS BEEN CONVEYED BY MUCH OF THE NUMERICAL GUIDANCE.
POPS INCREASED FROM PREVIOUS FORECAST WITH SOME LINGER SHOWERS AND
THUNDERSTORMS TONIGHT. THE COVERAGE WILL BE HIGHEST OUT
EAST...WHERE BETTER DYNAMICS WILL BE.
BLEND OF MET...MAV...AND NAM12 SFC TEMPS FOR MIN TEMPS TONIGHT
WITHOUT MUCH DIURNAL TEMP RANGE EXPECTED. SOUTHERLY FLOW WILL BE STILL
IN PLACE. A WAVE OF LOW PRESSURE DEVELOPS ALONG THE COLD FRONT
WHICH WILL BE MOVING INTO THE REGION.
2/3 MAV AND 1/3 MET FOR MAX TEMPS ON SUN. AGAIN...THIS IS FAVORING
THE COOLER GUIDANCE. IT DOES APPEAR THIS WILL BE A WARMER DAY FOR
WESTERN SECTIONS AS DRIER AIR MOVES FARTHER EAST IN THE AFTERNOON
HOURS BEHIND THE COLD FRONT. POPS FOR SHOWERS DIMINISH AS WELL FROM
WEST TO EAST. THUNDERSTORMS WILL BE MORE ISOLATED GIVEN THE LOWER
CAPE ACROSS THE REGION OF LESS THAN 1000 J/KG FOR MOST LOCATIONS.
FOR MONDAY....COLD FRONT EAST OF REGION AND MORE STABLE AIR IN
PLACE AS HIGH PRESSURE BUILDS IN. WARMER TEMPS EXPECTED WITH WARMER
MET GUIDANCE CHOSEN. FLOW AT SFC TURNS MORE WESTERLY WITH DRIER
AIR WORKING ITS WAY IN...HELPING INCREASE DIURNAL WARMTH. MAV/MET
BLEND USED FOR MIN TEMPS MONDAY NIGHT WITH NEAR NORMAL TEMPS
EXPECTED AS HIGH PRESSURE MOVES OFFSHORE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
WITH THE HIGH MOVING OFFSHORE MONDAY NIGHT AND LOW PRES TRACKING
THROUGH THE GREAT LAKES AND OHIO VALLEY...A WARM FRONT WILL LIFT
NORTH INTO THE REGION MONDAY NIGHT/TUESDAY MORNING. SOME
SHOWERS/THUNDERSTORMS EXPECTED WITH ITS PASSAGE. AS THE LOW TRACKS
INTO EASTERN CANADA...A SECONDARY LOW WILL FORM OVER THE DELMARVA
AREA ON TUESDAY...AND THIS SYSTEM WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH WEDNESDAY.
WEAK HIGH PRES WILL MOVE THROUGH THE REGION THURSDAY...THEN
ANOTHER SYSTEM WILL IMPACT THE AREA LATE IN THE WEEK. THERE ARE
INCONSISTENCIES AMONG THE MODELS...RESULTING IN A LOW CONFIDENCE
FORECAST FOR THE LONG TERM PERIOD. HPC GUIDANCE WAS CLOSELY
FOLLOWED AS A RESULT.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
ISOLATED TO SCATTERED CONVECTION LIKELY TO STAY EAST OF THE
TERMINALS OVERNIGHT WITH THE EXCEPTION OF KGON.
LOW CONFIDENCE FORECAST. HAVE FOLLOWED PERSISTENCE FROM THE LAST
FEW NIGHT WITH AREAS OF MVFR TO LOCALLY IFR THROUGH 12Z OR SO WITH
MOIST LOW LEVELS.
ANOTHER WEAK BOUNDARY IS FORECAST TO LIFT N OF
THE AREA LATER THIS MORNING AND AFTERNOON. SHOWERS AND TSTMS
LIKELY DEVELOP AGAIN AHEAD OF IT AND CURRENT TIMING MAY NOT BE
EARLY ENOUGH. LATEST HRRR MOVED UP THE TIMING FROM 15Z BACK TO
13Z. IF THIS TREND CONTINUES AND START TO SEE DEVELOPMENT TO THE
S...WILL NEED TO AMEND TIMING IN 06Z TAFS. CIGS WILL LIKELY VARY
FROM VFR TO MVFR/IFR WITH ANY CONVECTION.
COLD FRONT ADVANCING FROM THE WEST WILL ALSO TRIGGER SCT
CONVECTION DURING THE AFTN. MORNING ACTIVITY WILL DETERMINE
WHETHER AIRMASS CAN RECOVER FOR MORE STORMS IN THE AFTN. HAVE
CONTINUED WITH PROB30.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SAT NIGHT...AREAS OF MVFR TO IFR IN FOG/STRATUS.
.SUN-TUE MORN...VFR.
.TUE AFTN-WED...SCT SHOWERS AND TSTMS.
&&
.MARINE...
WEAK WARM FRONTAL BOUNDARY LIFTS N OF THE WATERS LATER THIS
MORNING/AFTN. MEANWHILE...A COLD FRONT AND WAVE OF LOW PRES WILL
APPROACH FROM THE WEST AND SLOWLY MOVE ACROSS THE AREA SUN AND SUN
NIGHT.
TIGHTENING PRES GRADIENT TODAY WITH SLY WINDS 10-20 KT ON THE
WATERS...HIGHEST ON THE OCEAN. GUSTS ON THE OCEAN WATERS MAY FALL
SHORT OF ADVSY LEVELS THIS AFTN...BUT SEAS WILL REMAIN BETWEEN 5 AND
7 FT THROUGH TONIGHT. SCA REMAINS IN PLACE AS A RESULT. MARGINAL
SEAS MAY LINGER INTO SUNDAY MORNING...MAINLY ON EASTERN OCEAN
WATERS...BUT DO NOT HAVE THE CONFIDENCE TO EXTEND INTO THE THIRD
PERIOD AT THIS POINT...ESPECIALLY SINCE WW3 HAS BEEN RUNNING HIGH
ALL SEASON.
HIGH PRES BUILDS IN FOR MONDAY INTO TUE...THEN ANOTHER FRONTAL
SYSTEM WITH UNSETTLED WEATHER RETURNS FOR THE MIDDLE OF THE WEEK.
SUB-ADVSY CONDS ARE EXPECTED DURING THIS TIME.
&&
.HYDROLOGY...
STILL LOOKING AT A HEAVY RAIN THREAT WITH PWATS NEAR 1.8 TO 2 INCHES
FOR TODAY AND TONIGHT...ESPECIALLY FOR EASTERN SECTIONS OF THE
FORECAST REGION. ADDITIONAL RAINFALL TOTALS THROUGH SUNDAY ARE
BASIN AVERAGED FROM 1/2 TO 1 INCH. HIGHER AMOUNTS WILL BE POSSIBLE
UP TO 2 INCHES HERE THOUGH. SIMILAR TO YESTERDAY...MINOR FLOODING
SEEMS TO BE MAIN THREAT WITH ISOLATED FLASH FLOODING POSSIBLE.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM
NEAR TERM...JM
SHORT TERM...JM
LONG TERM...MPS
AVIATION...24
MARINE...24
HYDROLOGY...JM
AREA FORECAST DISCUSSION
NWS NEW YORK NY
246 AM EDT SAT AUG 11 2012
.SYNOPSIS...
A SLOW MOVING COLD FRONT APPROACHES FROM THE WEST THROUGH THE
FIRST HALF OF THE WEEKEND...THEN PASSES TO THE EAST SUNDAY
MORNING. HIGH PRESSURE BUILDS INTO THE REGION FOR THE START OF THE
NEW WEEK...THEN UNSETTLED WEATHER RETURNS LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LOW PRESSURE OVER THE OHIO VALLEY WILL CONTINUE TO SLOWLY
RETROGRADE TOWARDS LAKE HURON INTO EARLY SATURDAY MORNING. THIS
WILL BEGIN A SLIGHT WEAKENING TREND AS THE UPPER LEVEL LOW WILL BE
DIRECTLY OVERHEAD...LIMITING FAVORABLE VORTICITY AND TEMPERATURE
ADVECTIONS WITH AN EQUIVALENT BAROTROPIC STRUCTURE. THE ASSOCIATED
FRONTAL SYSTEM TO THE SOUTH AND EAST WILL BECOME SLOWER IN MOVEMENT.
THE AREA REMAINS IN THE WARM SECTOR WITH HIGH PRECIPITABLE WATER
VALUES OF 1.7 TO 2 INCHES AND HIGHEST CAPE VALUES ON ORDER OF
1000-1500 J/KG ALONG PORTIONS OF LONG ISLAND AND HIGHER TO THE
SOUTH. NOT EXPECTING MUCH FURTHER DROP IN TEMPS AND THESE AS WELL
AS DEWPOINTS ARE ON TRACK. LOWS IN THE UPPER 60S TO LOWER 70S FOR
MOST PLACES WITH PATCHY FOG EXPECTED TOWARDS MORNING WITH NEARLY
SATURATED AIRMASS IN PLACE.
LOOKING FOR CONVECTION TO BECOME GENERALLY ISOLATED UNTIL ANOTHER
MID LEVEL IMPULSE ARRIVES TOWARDS SATURDAY MORNING AS THE BROKEN
LINE OF CONVECTION FROM THE WEST APPROACHES THE CWA. AT THE
SFC...THIS WILL BE SEEN AS A WEAK WARM FRONT ASSOCIATED WITH
SECONDARY LOW DEVELOPMENT TOWARDS THE DELMARVA. WITH HIGH PW
VALUES...KEPT MENTION OF HEAVY RAIN POTENTIAL BY SATURDAY MORNING.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY NIGHT/...
SOME QUESTIONS AS TO HOW MUCH PRECIP WILL MAKE IT TO THE LOCAL
AREA DURING THE DAY ON SATURDAY. WITH THE COLD FRONT WEST OF THE
AREA TRACKING EAST AND LOW PRES MOVING ALONG THE COAST...SHOWERS
WILL DEVELOP ONCE AGAIN OVER THE AREA...BUT IT LOOKS LIKE THE BULK
OF THE PRECIP COULD BE CONFINED TO EASTERN ZONES AND OVER THE
OCEAN. WILL CARRY LIKELY POPS FOR THE EASTERN ZONES AND CHANCE
OVER THE WESTERN ZONES FOR SATURDAY AND SATURDAY NIGHT AS THE
FRONT SLOWLY MOVES THROUGH THE REGION.
ON SUNDAY...THE FRONT SHOULD BE THROUGH WESTERN ZONES...AND WILL
EXPECT MAINLY DRY CONDS FOR WESTERN ZONES SATURDAY NIGHT AND
SUNDAY...AND LOW CHANCE POPS AHEAD OF THE FRONT OVER THE EASTERN
ZONES. BY SUNDAY NIGHT...PRECIP WILL BE EAST OF THE AREA AND HIGH
PRES TO THE WEST WILL NOSE ITS WAY INTO THE REGION FROM THE WEST.
CLOUD COVER SHOULD KEEP INSTABILITY PARAMETERS LOW...AND
THUNDERSTORMS SHOULD BE ISOLATED TO SCATTERED...PRODUCING LOCALLY
HEAVY RAIN AND GUSTY WINDS.
THERE IS A MODERATE RISK FOR RIP CURRENTS ALONG THE SOUTH SHORE OF
LONG ISLAND IN THE AFTERNOON AND EVENING.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
HIGH PRES BUILDS INTO THE REGION MONDAY AND MOVES OFFSHORE MONDAY
NIGHT. DRY AND MILD CONDS WITH TEMPS RUNNING A FEW DEGREES ABOVE
NORMAL...TOPPING OUT IN THE MID TO UPPER 80S.
WITH THE HIGH MOVING OFFSHORE MONDAY NIGHT AND LOW PRES TRACKING
THROUGH THE GREAT LAKES AND OHIO VALLEY...A WARM FRONT WILL LIFT
NORTH INTO THE REGION MONDAY NIGHT/TUESDAY MORNING. SOME
SHOWERS/THUNDERSTORMS EXPECTED WITH ITS PASSAGE. AS THE LOW TRACKS
INTO EASTERN CANADA...A SECONDARY LOW WILL FORM OVER THE DELMARVA
AREA ON TUESDAY...AND THIS SYSTEM WILL KEEP SHOWERS AND
THUNDERSTORMS IN THE FORECAST THROUGH WEDNESDAY.
WEAK HIGH PRES WILL MOVE THROUGH THE REGION THURSDAY...THEN
ANOTHER SYSTEM WILL IMPACT THE AREA LATE IN THE WEEK. THERE ARE
INCONSISTENCIES AMONG THE MODELS...RESULTING IN A LOW CONFIDENCE
FORECAST FOR THE LONG TERM PERIOD. HPC GUIDANCE WAS CLOSELY
FOLLOWED AS A RESULT.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
ISOLATED TO SCATTERED CONVECTION LIKELY TO STAY EAST OF THE
TERMINALS OVERNIGHT WITH THE EXCEPTION OF KGON.
LOW CONFIDENCE FORECAST. HAVE FOLLOWED PERSISTENCE FROM THE LAST
FEW NIGHT WITH AREAS OF MVFR TO LOCALLY IFR THROUGH 12Z OR SO WITH
MOIST LOW LEVELS.
ANOTHER WEAK BOUNDARY IS FORECAST TO LIFT N OF
THE AREA LATER THIS MORNING AND AFTERNOON. SHOWERS AND TSTMS
LIKELY DEVELOP AGAIN AHEAD OF IT AND CURRENT TIMING MAY NOT BE
EARLY ENOUGH. LATEST HRRR MOVED UP THE TIMING FROM 15Z BACK TO
13Z. IF THIS TREND CONTINUES AND START TO SEE DEVELOPMENT TO THE
S...WILL NEED TO AMEND TIMING IN 06Z TAFS. CIGS WILL LIKELY VARY
FROM VFR TO MVFR/IFR WITH ANY CONVECTION.
COLD FRONT ADVANCING FROM THE WEST WILL ALSO TRIGGER SCT
CONVECTION DURING THE AFTN. MORNING ACTIVITY WILL DETERMINE
WHETHER AIRMASS CAN RECOVER FOR MORE STORMS IN THE AFTN. HAVE
CONTINUED WITH PROB30.
OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SAT NIGHT...AREAS OF MVFR TO IFR IN FOG/STRATUS.
.SUN-TUE MORN...VFR.
.TUE AFTN-WED...SCT SHOWERS AND TSTMS.
&&
.MARINE...
SOUTHERLY FLOW INCREASES TONIGHT AS A WARM FRONT LIFTS NORTH.
EXPECTING SUB-SCA WINDS/SEAS ON LI SOUND/NY HARBOR/LI BAYS...BUT A
FEW GUSTS TO 20 KT ARE POSSIBLE. ON THE OCEAN...25 KT GUSTS
EXPECTED TONIGHT THROUGH SATURDAY...AND SEAS WILL BUILD TO 4-6 FT
BEGINNING TONIGHT. SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR
TONIGHT THROUGH SATURDAY...AND WILL GO AHEAD AND EXTEND IT THROUGH
SATURDAY NIGHT. SEAS MAY REMAIN UP THROUGH SUNDAY BEFORE SLOWLY
SUBSIDING FROM WEST TO EAST.
UNSETTLED WEATHER EXPECTED ON THE WATERS AS SEVERAL AREAS OF LOW
PRES TRACK NORTH ALONG THE COAST. BY SUNDAY NIGHT...COLD FRONT
WILL BE EAST OF THE AREA AND HIGH PRES WILL BUILD INTO THE WATERS.
DRY CONDS FOR THE START OF THE WEEK...THEN UNSETTLED WEATHER ON
TAP FOR THE MIDDLE TO END OF NEXT WEEK. SUB-SCA CONDS EXPECTED FOR
THE NEW WEEK.
&&
.HYDROLOGY...
MUCH LESS PRECIP EXPECTED IN THE OVERNIGHT HOURS INTO TOMORROW.
RAINFALL TOTALS BETWEEN 1/4 AND 3/4 IN ARE POSSIBLE...WITH
ISOLATED AREAS POSSIBLY HITTING 1 INCH WITH ANY HEAVIER
THUNDERSTORMS.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT SUNDAY FOR ANZ350-353-355.
&&
$$
AREA FORECAST DISCUSSION
NWS LINCOLN IL
911 PM CDT SUN AUG 12 2012
.DISCUSSION...
ISSUED 910 PM CDT SUN AUG 12 2012
EARLIER SPRINKLES HAVE EXITED THE AREA. NEXT ROUND OF SHOWERS HAS
BEEN INCREASING NORTHWEST OF THE ILLINOIS RIVER OVER THE LAST HOUR
OR TWO...WITH SOME EMBEDDED THUNDERSTORMS MAINLY IN AREAS NEAR AND
NORTHWEST OF QUINCY. BULK OF THE RAIN HAS BEEN ALONG AND NORTH OF
A WARM FRONT/TROUGH THAT EXTENDS ACROSS NORTHERN MISSOURI TO NEAR
BLOOMINGTON. LATEST HRRR GUIDANCE HAS BEEN DOING A REASONABLE JOB
WITH THE COVERAGE OF THESE SHOWERS...AND SHOWS THE HIGHEST RAIN
CHANCES OVER THE NORTHERN HALF OF THE CWA OVER THE NEXT SEVERAL
HOURS. SOUTH OF THE BOUNDARY...SCATTERED SHOWERS AND STORMS HAVE
BEEN DEVELOPING AHEAD OF A COLD FRONT WHICH EXTENDS SOUTHWEST TO
NORTHEAST ACROSS MISSOURI. IT WILL LIKELY TAKE UNTIL AFTER
MIDNIGHT BEFORE THESE REACH THE SOUTHEAST CWA. THE SHOWERS WILL
PROBABLY BE EXITING THE SOUTHEAST CWA SHORTLY BEFORE SUNRISE... AS
SOME DRY SLOTTING TAKES PLACE OVER WEST CENTRAL ILLINOIS.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 635 PM CDT SUN AUG 12 2012
EARLIER BAND OF SPRINKLES IS EXITING THE AREA...BUT ADDITIONAL
SHOWERS AND SCATTERED THUNDERSTORMS WERE MOVING OUT OF SOUTHEAST
IOWA. THESE WILL BE APPROACHING KPIA BY 02Z AND KBMI TOWARD 03Z.
ADDITIONAL CONVECTIVE DEVELOPMENT WAS OCCURRING IN NORTH CENTRAL
MISSOURI ALONG A COLD FRONT...AND THIS WILL INCREASE AS IT MOVES
INTO WEST CENTRAL ILLINOIS LATER THIS EVENING. SHOULD SEE SHOWERS
BECOME WIDESPREAD OVER THE TAF SITES BY LATE EVENING...WITH A FEW
EMBEDDED THUNDERSTORMS. FIRST WAVE OF SHOWERS SHOULD LARGELY BE
OUT OF THE AREA BY 12-13Z...BUT WILL SEE SOME SCATTERED
DEVELOPMENT AGAIN LATE MORNING AS THE FRONT PUSHES THROUGH THE
AREA. MUCH OF THIS SHOULD BE OUT OF THE AREA BY MID AFTERNOON.
WINDS WILL BE TRICKY...AS A WARM FRONT CURRENTLY EXTENDS FROM
NORTH CENTRAL MISSOURI EASTWARD TO NEAR KPIA/KBMI. WINDS WILL VARY
FROM NORTHEAST TO SOUTHEAST DEPENDING ON WHAT SIDE OF THE FRONT
EACH TAF SITE ENDS UP ON...WITH THIS FRONT REMAINING OVER CENTRAL
ILLINOIS MUCH OF THE NIGHT. THE PARENT LOW PRESSURE WILL MOVE INTO
THE AREA LATE MONDAY MORNING...WITH WINDS SWINGING AROUND TO THE
NORTH AS THE LOW PASSES.
GEELHART
&&
.PREV DISCUSSION...
ISSUED 259 PM CDT SUN AUG 12 2012
ANOTHER RELATIVELY COOL DAY ACROSS MOST OF CENTRAL ILLINOIS...
WHILE SOUTHEAST ILLINOIS IS WARMER DUE TO RECEIVING MORE SUN
BEFORE THE CLOUDS MOVED IN. THESE CLOUDS ARE ASSOCIATED WITH AN
APPROACHING CLIPPER TYPE SYSTEM...SOMEWHAT UNUSUAL FOR THE MIDDLE
OF SUMMER...THAT IS EXPECTED TO IMPACT THE AREA FOR THE NEXT 24-36
HOURS. MAIN FORECAST CONCERNS TODAY REVOLVE AROUND PRECIPITATION
CHANCES AND TEMPERATURES WHILE THIS SYSTEM MOVES THROUGH. OTHER
THAN THAT...THE WEATHER FOR THE COMING WEEK IS RATHER QUIET..WITH
THE EXCEPTION BEING A STRONG FRONTAL PASSAGE AROUND THURSDAY NIGHT
AND THE ASSOCIATED RISK OF SHOWERS/STORMS. TEMPERATURES WILL
AVERAGE COOLER THAN NORMAL FOR MUCH OF THE WEEK...ESPECIALLY BY
NEXT WEEKEND...A RARE OCCURRENCE THIS SUMMER..
12Z MODELS IN GOOD AGREEMENT OVERALL. HOWEVER...THE GFS HAS BEEN
IGNORED FOR THE APPROACHING SYSTEM. THE MORE SOUTHERN SURFACE LOW
TRACK ADVERTISED BY THE MODEL CONSENSUS IS SUPPORTED BY RECENT
SURFACE PRESSURE FALLS AND MAKES MORE SENSE CONSIDERING THE LOW
LEVEL THERMAL FIELD.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...THE UPSTREAM SYSTEM IS
PROGGED TO TRACK THROUGH THE LOWER MIDWEST...WITH THE SURFACE
LOW TRACKING IN THE VICINITY OF THE MO/IL BORDER. WEAK
WAA/ISENTROPIC LIFT IN ADVANCE OF THE SYSTEM HAS RESULTED IN
ABUNDANT MID/HIGH LEVEL CLOUDINESS AND SOME LIGHT SHOWERS. MANY OF
THE ECHOES ON RADAR ARE NOT REACHING THE GROUND OR ONLY FALLING AS
VERY LIGHT SPRINKLES DUE TO A DRY LOW LEVEL AIRMASS. WHILE MOST OF
THE FORECAST AREA SHOULD BE NORTH OF THE SURFACE LOW TRACK...THE
EXPECTED FORCING AND MOISTURE AVAILABILITY AS THE SYSTEM MOVES
THROUGH SHOULD PRECLUDE SIGNIFICANT RAINFALL. WATER VAPOR IMAGERY
IS ALREADY SHOWING DRY AIR BEING WRAPPED INTO UPPER WAVE WHICH IS
NOT GOING TO BE CONDUCIVE FOR IT BEING A GOOD RAIN PRODUCER.
PRECIPITATION CHANCES WILL END FROM WEST TO EAST MONDAY AS THE
SYSTEM DEPARTS.
HIGH PRESSURE AT THE SURFACE AND NEUTRAL FLOW ALOFT WILL BUILD IN
BEHIND THE EARLY WEEK SYSTEM AND PROVIDE QUIET WEATHER.
TEMPERATURES WILL MODERATE EACH DAY...WITH WEDNESDAY EXPECTED TO
BE THE HOTTEST DAY OF THE WEEK WITH THE BEST COMBINATION OF
SUNSHINE AND SOUTHERLY RETURN FLOW.
LONG TERM...THURSDAY THROUGH SUNDAY...A VIGOROUS WAVE/STRONG COLD
FRONT IS PROGGED TO ARRIVE AROUND THURSDAY NIGHT. THERE HAS BEEN A
SLIGHTLY SLOWER TREND IN THE MODEL CONSENSUS...AND HAVE REMOVED
MENTIONABLE POPS FROM WEDNESDAY NIGHT. IF THE SLOWER TREND
CONTINUES...THURSDAY MAY END UP DRY AS WELL. WHILE IT IS TOO SOON
TO TELL WITH ANY CERTAINTY...THIS SYSTEM IS APT TO BE STRONG
ENOUGH TO BE A SEVERE WEATHER PRODUCER...ESPECIALLY IF THE FRONT
ARRIVES AT THE RIGHT TIME OF DAY. THE UPPER LEVEL FLOW IS EXPECTED
TO AMPLIFY HEADING INTO THE WEEKEND BEHIND THE WAVE/FRONT AND
SHOULD USHER IN ANOTHER UNSEASONABLY COOL AUGUST AIRMASS AS
TROFFING DIGS ACROSS THE EASTERN UNITED STATES.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
749 PM CDT SUN AUG 12 2012
.UPDATE...
STILL A SMALL OPPORTUNITY FOR A FEW THUNDERSTORMS OVER EXTREME
SOUTHEAST KANSAS THROUGH ABOUT 10 PM...AS THE COLD FRONT CONTINUES
TO SLOWLY MOVE SOUTHEAST. POOR LAPSE RATES PER 00Z SPRINGFIELD
SOUNDING AND ONLY MODEST LOW-LEVEL MOISTURE IS PREVENTING OFF THE
CHARTS INSTABILITY...ALTHOUGH 40 KTS OF DEEP LAYER SHEAR WOULD
SUPPORT STRONG TO MARGINALLY SEVERE WIND/HAIL WITH ANY ACTIVITY
THAT CAN DEVELOP. THREAT SHOULD END BY 10 PM.
KLEINSASSER
&&
.PREV DISCUSSION... /ISSUED 636 PM CDT SUN AUG 12 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
NARROW WINDOW FOR A STRAY THUNDERSTORM AT KCNU WILL END BY 01-02Z
THIS EVENING...ALONG A COLD FRONT SHIFTING SOUTHEAST ACROSS THE
REGION. DUE TO LOW PROBABILITIES...DID NOT INCLUDE VCTS IN KCNU
TAF. OTHERWISE...MODEST NORTH WINDS WILL CONTINUE TONIGHT. BY
11-13Z EARLY MONDAY MORNING...ANTICIPATING MVFR CIGS TO FILTER
SOUTH ACROSS EASTERN KS...AFFECTING PRIMARILY KCNU ALTHOUGH
WESTERN EDGE COULD CLIP KICT-KSLN. CIGS SHOULD RISE ABOVE MVFR BY
LATE MORNING/EARLY AFTERNOON...WITH MODESTLY GUSTY NORTH WINDS
ANTICIPATED AGAIN MONDAY MORNING THROUGH AFTERNOON.
KLEINSASSER
PREV DISCUSSION... /ISSUED 351 PM CDT SUN AUG 12 2012/
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH TUESDAY
IN THE VERY SHORT TERM...SMALL CU BEGINNING TO DEVELOP ACROSS EXTREME
EASTERN KANSAS DUE TO DIURNAL MIXING AND WEAK ISENTROPIC LIFT...WITH
ADDITIONAL COLD CORE CU MOVING INTO NORTHEAST KANSAS. RIGHT
NOW...CU DEVELOPMENT IS NOT OVERLY IMPRESSIVE...HOWEVER SPC MESO
GRAPHICS INDICATED UNCAPPED ENVIRONMENT ACROSS SOUTHEAST KANSAS
AHEAD OF FRONTAL BOUNDARY CURRENTLY BISECTING CWA. HRRR AND RUC
BOTH GIVING INFINITESIMAL CHANCE OF THUNDERSTORMS BRUSHING EXTREME
SOUTHEASTERN CWA BETWEEN 21/12 AND 01/13...THUS WILL MAINTAIN LOW
CHANCE PO0PS IN THIS AREA. THE REST OF THE CWA WILL REMAIN DRY
OVERNIGHT.
NEXT CHANCE OF PRECIPITATION COMES LATE MONDAY NIGHT INTO TUESDAY
AS MCS ROLLS OFF LEE SLOPE OF ROCKIES. MITIGATING FACTOR FOR
COVERAGE WILL BE LOW LEVEL MOISTURE AS FRONT CURRENTLY MOVING
THROUGH PLAINS WILL SCOUR MOISTURE. ISENTROPIC LIFT/MOIST ADVECTION
IMPROVES BETWEEN 06 AND 12 UTC ON TUESDAY...SO WILL TREND POPS UP IN
THIS TIME PERIOD. DISCREPANCY AS WELL ON EXACT TRACK AND SOUTHERN
DEVELOPMENT OF STORMS BETWEEN SHORT TERM MODELS AND ENSEMBLES...WILL
LEAN TOWARD EC SOLUTION WHICH KEEPS BULK OF PRECIP IN CLOSE
PROXIMITY TO BETTER QG AND ISENTROPIC FORCING. MCS THAT ROLLS
THROUGH APPEARS TO LEAVE BOUNDARIES AROUND THAT WILL ALLOW
ADDITIONAL DEVELOPMENT TUES AFTERNOON EVENING AS RRQ OF UPPER LEVEL
JET DIVES FROM CENTRAL PLAINS INTO LOWER MISSISSIPPI VALLEY.
OVERALL...TRENDED LOWER ON QPF AS WELL GIVEN DROUGHT TRENDS.
TEMPERATURES WILL BE PLEASANT...WITH NARY A 100 DEGREE IN SITE FOR
SOME TIME. LARGE SCALE TROUGH ACROSS EASTERN TWO THIRDS OF NATION
WILL KEEP HEAT AT BAY FOR A WHILE. NORTH TO NORTHEAST FLOW MONDAY
WILL KEEP TEMPERATURES BELOW NORMAL FOR THE FIRST TIME IN A LONG
TIME. THAT TREND CONTINUES THROUGH THE SHORT TERM...AS CLOUDS AND
CONVECTION WILL KEEP THINGS A LITTLE COOLER ON TUESDAY AS WELL.
DRYNESS OF SOIL WILL ALLOW FOR SUPERADIABATIC HEATING...SO WILL
TREND TOWARD HIGHER END OF GUIDANCE FOR THE MOST PART.
MEDIUM RANGE...WEDNESDAY THROUGH SATURDAY
ANOTHER ROUND OF SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO
THURSDAY AS POTENT SHORT WAVE MOVING THROUGH NORTHERN STREAM DRIVES
ANOTHER FRONTAL SYSTEM THROUGH CWA. MOISTURE AGAIN WILL BE
LIMITED...SO LITTLE SUSPECT OF GREATER POPS PROBABILITIES BEING
GENERATED BY GEFS AND CONSENSUS BLENDS. GIVEN RECENT DROUGHT
TRENDS...TONED PROBABILITIES BACK A LITTLE. AFTER
THURSDAY...SURFACE RIDGING WILL BE IN PLACE THROUGH THE EARLY
WEEKEND...THEN UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS AS EASTERN U.S. LARGE SCALE TROUGH EDGES EAST. THERE IS AN
OUTSIDE CHANCE OF CONVECTION RETURNING LATE IN THE WEEKEND DUE TO
ENHANCED RETURNED FLOW...BUT WILL LEAVE FORECAST DRY FOR NOW.
TEMPERATURES RETURN TO NORMAL ON WEDNESDAY HEAD OF AFOREMENTIONED
FRONTAL BOUNDARY...THEN ANOTHER SEVERAL DAYS OF BELOW NORMAL
TEMPERATURES IN STORE FOR THE CWA IN TERMS OF MAXIMUMS AND
MINIMUMS. USED A BLEND OF CONSENSUS FOR HIGHS AND GFS40 FOR
MINS...WHICH HAS BEEN DOING AMAZINGLY WELL GIVEN HOW POORLY IT HAS
HANDLED MAX TEMPERATURES OF LATE.
SF
PREV DISCUSSION... /ISSUED 1222 PM CDT SUN AUG 12 2012/
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
ISOLATED CONVECTION IS EXPECTED ALONG A COLD FRONT LATE THIS
AFTERNOON...WITH A FEW STORMS POSSIBLY AFFECTING SOUTHEAST KANSAS.
FRONTAL TIMING SUGGESTS THIS ACTIVITY WILL BE JUST SOUTH OF KCNU
THOUGH INCLUDED A VCTS FOR A FEW HOURS AT START OF FORECAST.
OTHERWISE GUSTY NORTH-NORTHWEST WINDS BEHIND THE FRONT WILL
DIMINISH THIS EVENING...ONLY TO PICK UP AGAIN AFTER SUNRISE ON
MONDAY MORNING ACROSS THE AREA.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 62 90 62 87 / 0 0 20 30
HUTCHINSON 60 87 62 88 / 0 0 20 30
NEWTON 60 86 60 88 / 0 0 20 30
ELDORADO 61 89 58 88 / 0 0 10 30
WINFIELD-KWLD 64 91 62 88 / 0 0 10 30
RUSSELL 57 87 60 88 / 0 0 30 30
GREAT BEND 58 87 61 88 / 0 0 30 30
SALINA 59 87 61 89 / 0 0 20 30
MCPHERSON 59 87 62 88 / 0 0 20 30
COFFEYVILLE 64 93 60 88 / 20 0 0 30
CHANUTE 62 89 58 88 / 10 0 0 30
IOLA 62 88 58 87 / 10 10 0 30
PARSONS-KPPF 64 90 60 88 / 20 0 0 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
636 PM CDT SUN AUG 12 2012
.AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
NARROW WINDOW FOR A STRAY THUNDERSTORM AT KCNU WILL END BY 01-02Z
THIS EVENING...ALONG A COLD FRONT SHIFTING SOUTHEAST ACROSS THE
REGION. DUE TO LOW PROBABILITIES...DID NOT INCLUDE VCTS IN KCNU
TAF. OTHERWISE...MODEST NORTH WINDS WILL CONTINUE TONIGHT. BY
11-13Z EARLY MONDAY MORNING...ANTICIPATING MVFR CIGS TO FILTER
SOUTH ACROSS EASTERN KS...AFFECTING PRIMARILY KCNU ALTHOUGH
WESTERN EDGE COULD CLIP KICT-KSLN. CIGS SHOULD RISE ABOVE MVFR BY
LATE MORNING/EARLY AFTERNOON...WITH MODESTLY GUSTY NORTH WINDS
ANTICIPATED AGAIN MONDAY MORNING THROUGH AFTERNOON.
KLEINSASSER
&&
.PREV DISCUSSION... /ISSUED 351 PM CDT SUN AUG 12 2012/
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH TUESDAY
IN THE VERY SHORT TERM...SMALL CU BEGINNING TO DEVELOP ACROSS EXTREME
EASTERN KANSAS DUE TO DIURNAL MIXING AND WEAK ISENTROPIC LIFT...WITH
ADDITIONAL COLD CORE CU MOVING INTO NORTHEAST KANSAS. RIGHT
NOW...CU DEVELOPMENT IS NOT OVERLY IMPRESSIVE...HOWEVER SPC MESO
GRAPHICS INDICATED UNCAPPED ENVIRONMENT ACROSS SOUTHEAST KANSAS
AHEAD OF FRONTAL BOUNDARY CURRENTLY BISECTING CWA. HRRR AND RUC
BOTH GIVING INFINITESIMAL CHANCE OF THUNDERSTORMS BRUSHING EXTREME
SOUTHEASTERN CWA BETWEEN 21/12 AND 01/13...THUS WILL MAINTAIN LOW
CHANCE PO0PS IN THIS AREA. THE REST OF THE CWA WILL REMAIN DRY
OVERNIGHT.
NEXT CHANCE OF PRECIPITATION COMES LATE MONDAY NIGHT INTO TUESDAY
AS MCS ROLLS OFF LEE SLOPE OF ROCKIES. MITIGATING FACTOR FOR
COVERAGE WILL BE LOW LEVEL MOISTURE AS FRONT CURRENTLY MOVING
THROUGH PLAINS WILL SCOUR MOISTURE. ISENTROPIC LIFT/MOIST ADVECTION
IMPROVES BETWEEN 06 AND 12 UTC ON TUESDAY...SO WILL TREND POPS UP IN
THIS TIME PERIOD. DISCREPANCY AS WELL ON EXACT TRACK AND SOUTHERN
DEVELOPMENT OF STORMS BETWEEN SHORT TERM MODELS AND ENSEMBLES...WILL
LEAN TOWARD EC SOLUTION WHICH KEEPS BULK OF PRECIP IN CLOSE
PROXIMITY TO BETTER QG AND ISENTROPIC FORCING. MCS THAT ROLLS
THROUGH APPEARS TO LEAVE BOUNDARIES AROUND THAT WILL ALLOW
ADDITIONAL DEVELOPMENT TUES AFTERNOON EVENING AS RRQ OF UPPER LEVEL
JET DIVES FROM CENTRAL PLAINS INTO LOWER MISSISSIPPI VALLEY.
OVERALL...TRENDED LOWER ON QPF AS WELL GIVEN DROUGHT TRENDS.
TEMPERATURES WILL BE PLEASANT...WITH NARY A 100 DEGREE IN SITE FOR
SOME TIME. LARGE SCALE TROUGH ACROSS EASTERN TWO THIRDS OF NATION
WILL KEEP HEAT AT BAY FOR A WHILE. NORTH TO NORTHEAST FLOW MONDAY
WILL KEEP TEMPERATURES BELOW NORMAL FOR THE FIRST TIME IN A LONG
TIME. THAT TREND CONTINUES THROUGH THE SHORT TERM...AS CLOUDS AND
CONVECTION WILL KEEP THINGS A LITTLE COOLER ON TUESDAY AS WELL.
DRYNESS OF SOIL WILL ALLOW FOR SUPERADIABATIC HEATING...SO WILL
TREND TOWARD HIGHER END OF GUIDANCE FOR THE MOST PART.
MEDIUM RANGE...WEDNESDAY THROUGH SATURDAY
ANOTHER ROUND OF SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO
THURSDAY AS POTENT SHORT WAVE MOVING THROUGH NORTHERN STREAM DRIVES
ANOTHER FRONTAL SYSTEM THROUGH CWA. MOISTURE AGAIN WILL BE
LIMITED...SO LITTLE SUSPECT OF GREATER POPS PROBABILITIES BEING
GENERATED BY GEFS AND CONSENSUS BLENDS. GIVEN RECENT DROUGHT
TRENDS...TONED PROBABILITIES BACK A LITTLE. AFTER
THURSDAY...SURFACE RIDGING WILL BE IN PLACE THROUGH THE EARLY
WEEKEND...THEN UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS AS EASTERN U.S. LARGE SCALE TROUGH EDGES EAST. THERE IS AN
OUTSIDE CHANCE OF CONVECTION RETURNING LATE IN THE WEEKEND DUE TO
ENHANCED RETURNED FLOW...BUT WILL LEAVE FORECAST DRY FOR NOW.
TEMPERATURES RETURN TO NORMAL ON WEDNESDAY HEAD OF AFOREMENTIONED
FRONTAL BOUNDARY...THEN ANOTHER SEVERAL DAYS OF BELOW NORMAL
TEMPERATURES IN STORE FOR THE CWA IN TERMS OF MAXIMUMS AND
MINIMUMS. USED A BLEND OF CONSENSUS FOR HIGHS AND GFS40 FOR
MINS...WHICH HAS BEEN DOING AMAZINGLY WELL GIVEN HOW POORLY IT HAS
HANDLED MAX TEMPERATURES OF LATE.
SF
PREV DISCUSSION... /ISSUED 1222 PM CDT SUN AUG 12 2012/
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
ISOLATED CONVECTION IS EXPECTED ALONG A COLD FRONT LATE THIS
AFTERNOON...WITH A FEW STORMS POSSIBLY AFFECTING SOUTHEAST KANSAS.
FRONTAL TIMING SUGGESTS THIS ACTIVITY WILL BE JUST SOUTH OF KCNU
THOUGH INCLUDED A VCTS FOR A FEW HOURS AT START OF FORECAST.
OTHERWISE GUSTY NORTH-NORTHWEST WINDS BEHIND THE FRONT WILL
DIMINISH THIS EVENING...ONLY TO PICK UP AGAIN AFTER SUNRISE ON
MONDAY MORNING ACROSS THE AREA.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 61 90 62 87 / 10 0 20 30
HUTCHINSON 59 87 62 88 / 10 0 20 30
NEWTON 59 86 60 88 / 10 0 20 30
ELDORADO 58 89 58 88 / 10 0 10 30
WINFIELD-KWLD 62 91 62 88 / 10 0 10 30
RUSSELL 58 87 60 88 / 0 0 30 30
GREAT BEND 59 87 61 88 / 0 0 30 30
SALINA 58 87 61 89 / 10 0 20 30
MCPHERSON 58 87 62 88 / 10 0 20 30
COFFEYVILLE 62 93 60 88 / 20 0 0 30
CHANUTE 60 89 58 88 / 30 0 0 30
IOLA 59 88 58 87 / 30 10 0 30
PARSONS-KPPF 61 90 60 88 / 20 0 0 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
200 PM MDT SAT AUG 11 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 108 PM MDT SAT AUG 11 2012
PRE-FRONTAL TROUGH AND ASSOCIATED WIND SHIFT LINE HAS MOVED INTO
THE FAR WESTERN PART OF THE FORECAST AREA. WATER VAPOR IMAGERY
SHOWS SHORT WAVE TROUGH CURRENTLY MOVING ACROSS SOUTHEAST WYOMING.
ALTHOUGH THE STRONGEST PART OF THE WAVE WILL BE NORTH OF FORECAST
AREA...THERE WILL BE ENOUGH DIFFERENTIAL CYCLONIC VORTICITY
ADVECTION TO PRODUCE SCATTERED CONVECTION. LATEST GFS IS SLIGHTLY
SLOWER WITH FEATURE...BUT STILL ON TRACK FOR SCATTERED PRECIPITATION
CHANCES TONIGHT.
KFTG RADAR IS SHOWING SIGNS OF CONVECTIVE DEVELOPMENT NORTH OF KLIC.
LATEST RUN OF THE HRRR MODEL CONTINUES TO PRODUCE SCATTERED
THUNDERSTORMS OVER EASTERN COLORADO FROM 21Z-23Z...WITH STORMS
MOVING OVER THE REST OF THE AREA AFTER THAT TIME. HRRR MAY BE
OVERDONE WITH THE AMOUNT OF COVERAGE...BUT HAS THE GENERAL IDEA.
BOTH THE NAM/GFS ALSO SHOW CONVECTION ADVECTING OVER MOST OF THE
AREA. THEREFORE...WILL CONTINUE WITH SCATTERED POPS THROUGH
MIDNIGHT. AS MENTIONED EARLIER...LOW LEVEL SHEAR IS MINIMAL.
SOUNDING PROFILES...HOWEVER..HAVE AN INVERTED-V SIGNATURE.
SO...SOME CONVECTIVE WIND GUSTS WILL APPROACH SEVERE LIMITS...THOUGH
WOULD LIKE TO SEE A LITTLE MORE IMPRESSIVE DOWNDRAFT CAPE. 700 MB
THETA/E AXIS WILL EXTEND FROM GOODLAND TO HASTINGS THIS EVENING...SO
A FEW STORMS MAY PRODUCE BRIEF HEAVY RAIN.
COLD FRONT AND DRIER AIR WILL MOVE ACROSS THE AREA AFTER 06Z.
1000/500 MB THICKNESS VALUES DROP...BUT NOT IMPRESSIVELY. WILL
ONLY COOL TEMPERATURES SEVERAL DEGREES TONIGHT AND SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 200 PM MDT SAT AUG 11 2012
SUNDAY NIGHT-MONDAY NIGHT...DRY SUNDAY NIGHT UNDER HIGH PRESSURE
WITH JUST A FEW CLOUDS. LOWS IN THE 50S. ON MONDAY A WEATHER
DISTURBANCE ENTERS THE SOUTHWEST AND WESTERN PORTION OF THE FORECAST
AREA MOVING EAST/SOUTHEAST ACROSS THE REMAINDER OF THE AREA MONDAY
NIGHT. THERE WILL BE A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS
WITH ITS PASSAGE. HIGH TEMPERATURES MONDAY IN THE MID 80S TO AROUND
90 WITH OVERNIGHT LOWS MONDAY NIGHT IN THE UPPER 50S TO LOW 60S.
TUESDAY...DRY WEATHER EXPECTED. NOT REAL CONFIDENT IN PRECIP CHANCES
TUESDAY NIGHT GIVEN RATHER POOR MOISTURE AVAILABILITY ACROSS THE
AREA. HIGHS IN THE LOW TO MID 90S.
WEDNESDAY...COVERAGE OF SHOWERS AND THUNDERSTORMS INCREASES THROUGH
WEDNESDAY NIGHT AS AN UPPER LEVEL TROUGH AND COLD FRONT MOVE ACROSS
THE AREA. HIGHS IN THE UPPER 80S TO LOW 90S WITH LOWS WEDNESDAY
NIGHT IN THE UPPER 50S TO MID 60S.
THURSDAY...MAY SEE SOME LINGERING PRECIPITATION DURING THE DAY
BEFORE MOISTURE AVAILABILITY DECREASES AS SFC HIGH MOVES IN THURSDAY
NIGHT. HIGHS IN THE MID 70S TO LOW 80S. OVERNIGHT LOWS IN THE MID TO
UPPER 50S.
FRIDAY-SATURDAY...UPPER RIDGE REBUILDS ACROSS THE INTERMOUNTAIN WEST
THROUGH THE PERIOD. MOISTURE AVAILABILITY FOR PRECIPITATION LOOKS
PRETTY LOW AS IS CONFIDENCE IN PRECIPITATION CHANCES. HIGHS ON
FRIDAY IN THE LOW 80S...WARMING INTO THE UPPER 80S TO AROUND 90.
OVERNIGHT LOWS IN THE MID 50S TO AROUND 60.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1040 AM MDT SAT AUG 11 2012
CONVECTION WILL DEVELOP OVER EASTERN COLORADO AROUND 21Z...AND
THEN MOVE EAST. BASED ON SHORT RANGE MODELS...THUNDERSTORMS WILL
LIKELY MOVE ACROSS KGLD BETWEEN 23Z-01Z. CONFIDENCE IS NOT AS HIGH
AT KMCK...SO INDICATED THUNDERSTORMS IN VICINITY OF THAT LOCATION
BETWEEN 01Z-03Z. SOUTH SURFACE WINDS 15-25 KNOTS WILL SWITCH TO
THE NORTHWEST BEHIND A WEAK COLD FRONT AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MENTZER
LONG TERM...99
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
108 PM MDT SAT AUG 11 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 108 PM MDT SAT AUG 11 2012
PRE-FRONTAL TROUGH AND ASSOCIATED WIND SHIFT LINE HAS MOVED INTO
THE FAR WESTERN PART OF THE FORECAST AREA. WATER VAPOR IMAGERY
SHOWS SHORT WAVE TROUGH CURRENTLY MOVING ACROSS SOUTHEAST WYOMING.
ALTHOUGH THE STRONGEST PART OF THE WAVE WILL BE NORTH OF FORECAST
AREA...THERE WILL BE ENOUGH DIFFERENTIAL CYCLONIC VORTICITY
ADVECTION TO PRODUCE SCATTERED CONVECTION. LATEST GFS IS SLIGHTLY
SLOWER WITH FEATURE...BUT STILL ON TRACK FOR SCATTERED PRECIPITATION
CHANCES TONIGHT.
KFTG RADAR IS SHOWING SIGNS OF CONVECTIVE DEVELOPMENT NORTH OF KLIC.
LATEST RUN OF THE HRRR MODEL CONTINUES TO PRODUCE SCATTERED
THUNDERSTORMS OVER EASTERN COLORADO FROM 21Z-23Z...WITH STORMS
MOVING OVER THE REST OF THE AREA AFTER THAT TIME. HRRR MAY BE
OVERDONE WITH THE AMOUNT OF COVERAGE...BUT HAS THE GENERAL IDEA.
BOTH THE NAM/GFS ALSO SHOW CONVECTION ADVECTING OVER MOST OF THE
AREA. THEREFORE...WILL CONTINUE WITH SCATTERED POPS THROUGH
MIDNIGHT. AS MENTIONED EARLIER...LOW LEVEL SHEAR IS MINIMAL.
SOUNDING PROFILES...HOWEVER..HAVE AN INVERTED-V SIGNATURE.
SO...SOME CONVECTIVE WIND GUSTS WILL APPROACH SEVERE LIMITS...THOUGH
WOULD LIKE TO SEE A LITTLE MORE IMPRESSIVE DOWNDRAFT CAPE. 700 MB
THETA/E AXIS WILL EXTEND FROM GOODLAND TO HASTINGS THIS EVENING...SO
A FEW STORMS MAY PRODUCE BRIEF HEAVY RAIN.
COLD FRONT AND DRIER AIR WILL MOVE ACROSS THE AREA AFTER 06Z.
1000/500 MB THICKNESS VALUES DROP...BUT NOT IMPRESSIVELY. WILL
ONLY COOL TEMPERATURES SEVERAL DEGREES TONIGHT AND SUNDAY.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 333 AM MDT SAT AUG 11 2012
A LEE SURFACE TROUGH WILL BEGIN TO DEEPEN AHEAD OF A SHORTWAVE
TROUGH OVER ALBERTA CANADA BY EARLY NEXT WEEK. AS A MINOR
DISTURBANCE MOVES ACROSS THE LOCAL REGION...THERE IS A CHANCE FOR
SOME SCATTERED CONVECTION TO OCCUR ALONG THE TROUGH AXIS AND MOVE
EASTWARD WITH THE SHORTWAVE. THE CHANCE FOR CONVECTION WILL CONTINUE
WED AS THE DOMINATING RIDGE OVER THE GREAT BASIN REGION CONTINUES TO
WEAKEN AS THE VIGOROUS UPPER LEVEL SHORTWAVE TROUGH MOVES DOWN
THROUGH CANADA AND INTO THE MIDWEST. THIS WILL ALLOW THE ASSOCIATED COLD FRONT
TO BE PUSHED ACROSS THE HIGH AND CENTRAL PLAINS BY EARLY WED MORNING.
COOLER TEMPERATURES WILL FOLLOW THE FRONTAL PASSAGE AND WILL COOL
EVEN FURTHER BY THURSDAY AFTERNOON AS ANOTHER COLD FRONT MAKES ITS
WAY ACROSS THE CENTRAL PLAINS. PRECIPITATION CHANCES LOOK TO
INCREASE WITH THIS SECOND FRONTAL PASSAGE BEFORE DECREASING BY LATE
NEXT WEEK WHEN THE SURFACE HIGH PRESSURE MOVES IN AND RIDGE BEGINS TO
REBUILD OVER THE WESTERN PORTION OF THE COUNTRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1040 AM MDT SAT AUG 11 2012
CONVECTION WILL DEVELOP OVER EASTERN COLORADO AROUND 21Z...AND
THEN MOVE EAST. BASED ON SHORT RANGE MODELS...THUNDERSTORMS WILL
LIKELY MOVE ACROSS KGLD BETWEEN 23Z-01Z. CONFIDENCE IS NOT AS HIGH
AT KMCK...SO INDICATED THUNDERSTORMS IN VICINITY OF THAT LOCATION
BETWEEN 01Z-03Z. SOUTH SURFACE WINDS 15-25 KNOTS WILL SWITCH TO
THE NORTHWEST BEHIND A WEAK COLD FRONT AFTER 00Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MENTZER
LONG TERM...PMM
AVIATION...MENTZER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1123 PM MDT FRI AUG 10 2012
.UPDATE...
ISSUED AT 539 PM MDT FRI AUG 10 2012
THUNDERSTORMS EARLY THIS EVENING HAVE BEEN CONFINED TO THE PALMER
DIVIDE AREA AND FRONT RANGE...SO REMOVED MENTION FOR THE EVENING
HOURS. HOWEVER...MODELS SHOW A ROBUST 40-50KT LOW LEVEL JET
DEVELOPING OVER THE AREA AFTER 06Z WITH MODEST ELEVATED
INSTABILITY OF A FEW HUNDRED J/KG. HRRR SIMULATED REFLECTIVITY
AND QPF OUTPUT FROM THE NAM AND GFS SUPPORT ADDING A SLIGHT CHANCE
MENTION FOR OVERNIGHT ELEVATED CONVECTION. HARD TO PIN DOWN ANY
LOCATION SO JUST BROAD BRUSHED ALL AREAS. THIS ACTIVITY...IF IT
DEVELOPS...COULD LINGER INTO SATURDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 231 PM MDT FRI AUG 10 2012
A WEATHER DISTURBANCE CURRENTLY PRODUCING A FEW THUNDERSTORMS IN
SOUTHWEST COLORADO IS EXPECTED TO MOVE INTO THE SOUTHERN COLORADO
HIGH COUNTRY AND ADJACENT PLAINS BY THE END OF TODAY THEN SOUTHEAST
INTO SOUTHWEST KANSAS BY MIDNIGHT BEFORE CONTINUING SOUTHEAST
SATURDAY MORNING. ANOTHER WEATHER SYSTEM AND ASSOCIATED SFC TROUGH
WILL BRING ANOTHER SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS TO
THE AREA SATURDAY AFTERNOON. PRECIPITATION CHANCES TONIGHT WILL BE
CONFINED TO AREAS IN EASTERN COLORADO AND SOUTH OF INTERSTATE 70.
OVERNIGHT LOWS IN THE UPPER 50S TO LOW 60S. HIGHS ON SATURDAY
GENERALLY IN THE 90S. IT SHOULD BE NOTED THAT 850MB TEMPERATURES
FROM THE NAM/UKMET SUPPORT READINGS CLOSER TO 100 DEGREES IN THE
HILL CITY...MCCOOK AND TRIBUNE AREAS. THE GFS 850MB TEMPERATURES
SUPPORT READINGS SEVERAL DEGREES COOLER.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 231 PM MDT FRI AUG 10 2012
MAIN FORECAST CONCERN WILL BE CHANCES FOR PRECIP. ACCOMPANYING THE
COLD FRONT SATURDAY NIGHT.
SATURDAY EVENING A COLD FRONT WILL BE OVER THE WESTERN THIRD TO HALF
OF THE AREA. MODELS DISAGREE WITH THE TIMING OF THE FRONT THROUGH
THE NIGHT AS WELL AS AVAILABLE MOISTURE TO WORK WITH. THE NAM/ECMWF
HAVE THE FRONT EXITING THE AREA DURING THE LATE EVENING...WHILE THE
GFS/SREF HAVE THE FRONT EXITING THE AREA BY EARLY SUNDAY MORNING.
FAVORED MORE OF A GFS/SREF SOLUTION SINCE ALMOST ALL OF THE GEFS
MEMBERS AGREED WITH THE GFS/SREF TIMING OF THE FRONT. MODELS HAVE
MOST OF THE LIFT/INSTABILITY FOCUSED ALONG THE FRONT...SO AM
THINKING THE MAJORITY OF THE PRECIPITATION ACTIVITY SHOULD REMAIN
TIED TO THE FRONT. 850-700MB FRONTOGENESIS INCREASE DURING THE
EVENING ALONG THE FRONT THEN DECLINE AS THE FRONT MOVES
SOUTHEAST...SO TRENDED PRECIP. CHANCES UPWARD IN THE EVENING THEN
LEVELED THEM OFF DURING THE OVERNIGHT HOURS. WITH 0-6KM SHEAR
AROUND 30 KTS...AM THINKING ANY SEVERE WEATHER THREAT SHOULD BE
CONFINED TO THE EVENING HOURS WHEN 700-500MB CAPE AND INSTABILITY
FROM DAYTIME HEATING ARE BEST.
SUNDAY WILL BE DRY AS HIGH PRESSURE BUILDS INTO THE AREA BEHIND THE
COLD FRONT. AHEAD OF THE HIGH PRESSURE WINDS WILL BE GUSTY DURING
THE DAY...MAINLY EAST OF A BENKELMAN TO GOVE LINE...WITH GUSTS UP TO
35 MPH POSSIBLE WHICH MAY CAUSE FIRE WEATHER CONCERNS. SEE FIRE WEATHER
SECTION FOR MORE INFORMATION. THE GUSTS WILL DECLINE DURING THE
EARLY EVENING AS MIXING DISSIPATES. DURING THE LATE AFTERNOON INTO
THE EVENING MODELS SHOW SOME SURFACE CONVERGENCE OVER THE FAR
SOUTHWEST PART OF THE AREA ON THE PERIPHERY OF THE SURFACE RIDGE.
HOWEVER 500MB SUBSIDENCE IS ALSO PRESENT OVER THE SAME AREA SO
WILL ONLY PLACE IN SILENT CHANCES AT THIS TIME.
THE MONDAY THROUGH FRIDAY PERIOD STARTS OUT WITH HIT AND MISS
PRECIPITATION CHANCES AS A FEW MINOR UPPER LEVEL DISTURBANCES MOVE
OVER THE TRI-STATE AREA. PRECIPITATION CHANCES INCREASE AS AN UPPER
LEVEL LONG WAVE TROUGH...THAT MOVES ON SHORE TUESDAY...PASSES OVER THE
AREA WEDNESDAY NIGHT AND THURSDAY BRINGING A COLD FRONT WITH IT.
PRECIPITATION CHANCES CONTINUE ON FRIDAY AS MINOR UPPER LEVEL
DISTURBANCES IN THE FLOW MOVE OVER THE AREA. TEMPERATURES WILL BE
NEAR NORMAL WITH HIGHS IN THE LOWER 90S AND LOWS IN THE LOWER/MID
60S AHEAD OF THE COLD FRONT...WITH HIGHS IN THE 80S AND LOWS IN THE MID
50S TO LOWER 60S BEHIND THE FRONT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1119 PM MDT FRI AUG 10 2012
VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE VALID
TAF PERIOD. HOWEVER...THERE ARE SOME WILD CARDS IN THE MIX.
OVERNIGHT...ISOLATED ELEVATED THUNDERSTORMS WILL DEVELOP. SOME
HINT OF THEM ALREADY APPARENT ON RADAR SOUTH OF KGLD. CONFIDENCE
IS LOW THAT A THUNDERSTORM WILL DIRECTLY IMPACT EITHER TERMINAL.
A LOW CHANCE OF THUNDERSTORMS WILL CONTINUE ON FRIDAY. SURFACE
WINDS WILL BE CHANGEABLE THROUGH THE PERIOD AS WELL...WITH GUSTY
SOUTH WINDS IN THE MORNING AND AFTERNOON FOLLOWED BY A COLD FRONT
AND WIND SHIFT TO THE NORTH FRIDAY NIGHT.
&&
.FIRE WEATHER...
ISSUED AT 231 PM MDT FRI AUG 10 2012
SUNDAY AFTERNOON WIND GUSTS UP TO 35 MPH MAY DEVELOP MAINLY IN THE
MCCOOK TO HILL CITY AREA. RELATIVE HUMIDITIES WILL FALL TO AROUND
25 PERCENT. THESE CONDITIONS ARE ABOVE OUR FIRE WEATHER
CRITERIA...SO AM NOT ANTICIPATING A HAZARD BEING NEEDED AT THIS
TIME. HOWEVER THE GUSTY WINDS WILL MAKE ANY FIRE THAT IS BURNING
DIFFICULT TO CONTROL.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...024
SHORT TERM...DDT
LONG TERM...JTL
AVIATION...024
FIRE WEATHER...JTL
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
942 PM CDT SUN AUG 12 2012
.DISCUSSION...
WHILE STORM COVERAGE HAS INCREASED SLIGHTLY ACROSS THE MIDDLE RED
RIVER VALLEY OF NE TX/SE OK/SW AR OVER THE LAST HOUR OR SO...STORM
SEVERITY HAS DECREASED OVER THE LAST COUPLE OF HOURS ACROSS
SE OK/NE TX. BELIEVE SLIGHT STABILIZATION OF THE BOUNDARY LAYER
HAS RESULTED IN THIS SLIGHT WEAKENING TREND. THE MAIN QUESTION AS
WE GO THROUGH THE NIGHT IS WHETHER THE DEVELOPMENT OF A NOCTURNAL
LOW LEVEL JET WILL RESULT IN AN INCREASE IN STORM COVERAGE AND
INTENSITY. THE 00Z NAM SAYS NO TO BOTH THESE QUESTIONS AND HAS
SUPPORT FROM THE LATEST HRRR AS WELL. FOR THIS UPDATE THIS
EVENING...HAVE LOWERED POPS ONLY 10 PERCENT ACROSS THE I-20
CORRIDOR OF NE TX/NW LA AND LOWERED EVERYTHING SOUTH OF A LFK/MLU
LINE DOWN TO SLIGHT CHANCE VARIETY. KEPT HIGH CHANCE GOING ACROSS
OUR N AND NW ZONES FOR NOW. WILL CONTINUE TO MONITOR TRENDS CLOSER
TO THE WATCH EXPIRATION AT 06Z TO SEE WHAT COVERAGE LOOKS LIKE BY
THEN.
DID RAISE TEMPS SLIGHTLY I-20 AND SOUTH AS THIS WILL BE HIGHLY
DEPENDENT ON AN INCREASE IN STORM COVERAGE AS WELL. OTHERWISE...
NO OTHER SIGNIFICANT CHANGES ATTM.
UPDATED ZONE PACKAGE ALREADY SENT...13.
&&
.AVIATION...
A COLD FRONT DRAPED ROUGHLY FROM KPBF...TO KOKC...TO KLBB HAS
TRIGGERED STRONG CONVECTION ACROSS SRN OK/N TX THIS EVENING. THIS
CONVECTION IS EXPECTED TO MOVE INTO THE REGION DURING THE NEXT
SEVERAL HOURS...AND MAY AFFECT KTXK/KTYR/KGGG. THE PICTURE IS A BIT
MORE UNCERTAIN FOR TERMINALS E OF THIS LINE...BUT MAY NEED TO ADD
TEMPO TSRA IN IF STORMS CONTINUE TO HOLD TOGETHER. VFR IS EXPECTED
TO PREVAIL THROUGH MOST OF THE PD. THE ONLY EXCEPTIONS WILL BE WITH
CONVECTION AND POSSIBILITY FOR SOME ISOLD MVFR CIGS BEFORE SUNRISE.
OTHERWISE...WINDS OUT OF THE S 5-10 KTS OVERNIGHT...VEERING WLY/NWLY
AT 10-12 KTS AFTER SUNRISE AS THE FRONT MAKES ITS WAY THROUGH THE
REGION. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 76 96 74 95 74 / 30 40 20 20 20
MLU 73 94 73 95 71 / 20 40 30 30 20
DEQ 72 94 65 93 67 / 40 20 10 20 20
TXK 74 96 68 94 71 / 40 30 10 20 20
ELD 72 95 69 94 68 / 30 40 20 20 20
TYR 77 98 72 96 74 / 30 30 20 20 20
GGG 77 98 71 96 73 / 30 30 20 20 20
LFK 77 97 75 96 75 / 20 40 20 30 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
13/12
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1147 PM CDT FRI AUG 10 2012
.DISCUSSION...
06Z TAF ISSUANCE.
&&
.AVIATION...
FRONTAL BOUNDARY OVER E TX/C LA IGNITED NUMEROUS STRONG TO SEVERE TSRA
ACROSS THE REGION...WITH THE LAST REMNANTS DISSIPATED OVER THE
NORTHERN ATCHAFALAYA BASIN A COUPLE OF HOURS AGO. THE BOUNDARY
HASN`T MOVED MUCH. 00Z NAM12 CONTINUES TO SHOW REDEVELOPMENT
BETWEEN 09-15Z ACROSS SC LA...WHICH WOULD AFFECT LFT/ARA DURING
THIS TIME. WILL PLACE VCSH WITH A TEMPO GROUP OF SHRA & MVFR
VSBY/CEILING 10-14Z. BY 15Z...BELIEVE SHRA WILL PUSH SOUTH OF THE
TERMINALS...AS DRIER AIR ALOFT FINALLY FILTERS ACROSS THE REGION.
DML
&&
.PREV DISCUSSION... /ISSUED 949 PM CDT FRI AUG 10 2012/
UPDATE...
WITH CONVECTION CONTINUING TO DECREASE OVER EAST CENTRAL
LOUISIANA...WILL GO AHEAD AND CANCELLED THE REMAINDER OF THE
SEVERE THUNDERSTORM WATCH.
RUA
PREV DISCUSSION... /ISSUED 921 PM CDT FRI AUG 10 2012/
UPDATE...
HAVE CANCELLED THE SEVERE THUNDERSTORM WATCH FOR ALL EXCEPT
PORTIONS OF EAST CENTRAL LOUISIANA...WHERE STILL SOME STRONG
STORMS PERSIST. THE STORMS ARE ALSO ON THE DOWNWARD TREND WITH THE
LOSS OF DAYTIME HEATING AND THE REAL GOOD INSTABILITY DECREASING. WILL
LIKELY BE ABLE TO CANCEL THE REMAINDER OF THE WATCH BEFORE EXPIRATION
TIME.
ACTIVITY DEVELOPED AHEAD OF A SOUTHWARD MOVING BOUNDARY THAT
DELINEATES...VERY MOIST MARITIME AIR TO THE SOUTH...WITH DRIER CONTINENTAL
AIR TO THE NORTH. THIS BOUNDARY WILL CONTINUE A SLOW MOVEMENT TO THE
SOUTH TONIGHT. COULD SEE SOME NOCTURNAL SHOWERS AND A FEW STORMS
DEVELOP DURING THE LATE NIGHT AND BEFORE SUNRISE SOUTH OF THE
BOUNDARY...MAINLY OVER LOWER ACADIANA...WHICH NAM AND RUC HINT AT. SO
WILL KEEP CHANCE POPS GOING IN THAT AREA...AND TAPER THEM OFF TO
SLIGHT CHANCE OR NONE...THE FURTHER WEST AND NORTH YOU GO.
RUA
PREV DISCUSSION... /ISSUED 711 PM CDT FRI AUG 10 2012/
UPDATE...
A QUICK UPDATE TO REMOVE SOME OF OUR SE TX COUNTIES FM THE WATCH
AND ADD A FEW FURTHER EAST IN LA. SCT STRONG TO SVR STORMS
CONTINUE FROM NR BEAUMONT NE TOWARD ALEXANDRIA AND
MARKSVILLE...WITH AN ESPECIALLY POTENT AND PROLIFIC LIGHTNING
PRODUCING STORM JUST NE OF THE CWA DROPPING SWD TOWARD AVOYELLES
PARISH. WILL CONTINUE TO MONITOR ACTIVITY...BUT ANTICIPATE MOST OF
IT WILL BE DECREASING IN INTENSITY AND COVERAGE THE NEXT FEW
HOURS. 24
PREV DISCUSSION... /ISSUED 617 PM CDT FRI AUG 10 2012/
DISCUSSION...
00Z TAF ISSUANCE.
AVIATION...
FRONTAL BOUNDARY OVER E TX/C LA IGNITING SCT/NUM TSRA JUST S OF
THE BOUNDARY...WHICH WILL CONTINUE TO MOVE S THIS EVENING.
INCREASED CHANCE OF TSRA EXPECTED FOR BPT/LCH BY 01-02Z...AND
LFT/ARA BY 02-03Z THIS EVENING...WITH ACTIVITY LINGERING THRU
05-06Z. SVR WATCH 572 FOR SE TX/C AND SW LA THRU 05Z...NOT
INCLUDING LFT/ARA. ACTIVITY EXPECTED TO DIMINISH BY 06Z...BUT
NAM12 SHOWS REDEVELOPMENT TOWARDS 09-12Z ACROSS SC LA...WHICH
WOULD AFFECT LFT/ARA DURING THIS TIME. WILL WAIT FOR 00Z RUN TO
BITE ON THIS.
DML
PREV DISCUSSION... /ISSUED 501 PM CDT FRI AUG 10 2012/
SYNOPSIS...
RUNNING A LITTLE LATE ON THE AFD THIS AFTN...BUT THAT TURNED OUT
TO BE OK AS SEVERE THUNDERSTORM WATCH 572 WAS ISSUED AS I WAS
PUTTING THIS TOGETHER EARLIER. ALREADY WENT AHEAD AND UPDATED
ZONE AND COASTAL FORECASTS FOR THE WATCH.
THE WATCH WAS PROMPTED BY A BAND OF STORMS THAT DEVELOPED QUICKLY
THIS AFTN ALONG A PREFRONTAL TROF FM NATCHEZ TO JASPER TO CONROE.
THESE STORMS RAPIDLY INTENSIFIED AS THEY ENTERED A VERY MOIST AND
HEATED ATMOSPHERE ACRS SE TX AND WRN LA...AND ARE CAPABLE OF
PRODUCING ABUNDANT CG LIGHTNING...GUSTY WINDS AND VERY HEAVY
RAINFALL.
OTHERWISE...THE LATEST UPPER AIR ANALYSES AND WV IMAGERY INDICATE
THE AREA IS BETWEEN A TROF TO THE EAST AND A RIDGE OF HIGH
PRESSURE ACRS THE SRN ROCKIES AND SW STATES. THIS IS PRODUCING A
NLY FLOW ALOFT...WITH SEVERAL DISTURBANCES TRAVELING SOUTHWARD
TOWARD THE REGION. ABUNDANT MOISTURE PERSISTS OVER THE AREA PER
12Z SOUNDINGS WITH PW VALUES AROUND 2 INCHES. AT THE SFC...A COLD
FRONT WAS LOCATED FM GREENWOOD MS TO NR MONROE TO CENTERVILLE
TX...SEPARATING DEWPOINTS IN THE MID 60S FM DEWPOINTS IN THE MID
70S.
DISCUSSION...
THINGS EXPECTED TO REMAIN ACTIVE FOR THROUGH EARLY EVENING AS
STORMS CONTINUE TO FIRE ALONG THE AFOREMENTIONED TROF...WITH
OUTFLOW BOUNDARY INTERACTIONS HELPING TO MAINTAIN ADDITIONAL
DEVELOPMENT. ACTIVITY WILL TRAVEL SOUTHWARD...AND SHOULD DIMINISH
BY MID-EVENING WITH THE LOSS OF DAYTIME HEATING...ALTHOUGH
ANOTHER IMPULSE FURTHER UPSTREAM COULD BRING SOME MORE SCT
ACTIVITY LATE TONIGHT.
THE BIG QUESTION IS HOW FAR SOUTH WILL THE FRONT GET...AND
VARIOUS MODEL GUIDANCE NOT IN TOTAL AGREEMENT ON HOW MANY OF US WILL
SEE AT LEAST SOME RELIEF FM THE HUMIDITY. THE ECMWF AND NAM BOTH
SHOW THE FRONT STALLING JUST NR OUR NRN CWA BORDER...WHILE THE
CANADIAN...OPERATIONAL GFS AND GEM SHOW THE FRONT TREKKING FURTHER
SOUTH INTO THE CWA...ESSENTIALLY STALLING IT CLOSER TO THE I-10
CORRIDOR. HPC GUIDANCE EARLIER TODAY LEANED TOWARD THE FORMER
SOLUTIONS...BUT THE LATEST FCST SHOWS THE FRONT MOVING FURTHER
SOUTH BEFORE STALLING. FOR THE GRIDS...CHOSE A BLEND OF
GUIDANCE BUT WEIGHTED A LITTLE MORE ON THE NORTHERLY
SOLUTIONS...WITH THE FRONT MAKING IT THROUGH AT LEAST THE NRN
TIER OF COUNTIES/PARISHES.
EXPECT SCT SHOWERS AND THUNDERSTORMS AGAIN SATURDAY...MAINLY ACRS
SRN PORTIONS OF THE AREA WITH THE FRONT GRADUALLY WASHING OUT
SATURDAY NIGHT INTO SUNDAY. RAIN CHANCES DIMINISH ON SUNDAY...WITH
A RETURN TO A MORE TYPICAL SUMMERTIME PATTERN BY EARLY NEXT WEEK.
HIGH PRESSURE WILL BECOME REESTABLISHED OVER THE NRN GULF AND GULF
COAST STATES...WITH AFTN HIGHS IN THE 90S AND LOWS IN THE 70S.
MARINE...
HIGH PRESSURE RIDGING OVER THE NORTHERN GULF WILL MAINTAIN A
LIGHT TO MODERATE SOUTHWESTERLY FLOW TONIGHT...WITH WINDS
DIMINISHING OVER THE WEEKEND AS A WEAK FRONT STALLS ACROSS THE
GULF COAST STATES. SCATTERED SHOWERS AND THUNDERSTORMS WILL BE
POSSIBLE MAINLY EAST OF SABINE PASS. A GENERALLY LIGHT ONSHORE
FLOW...LOW SEAS AND MORE TYPICAL LATE NIGHT/EARLY MORNING SHOWERS
WILL RESUME INTO THE COMING WEEK AS HIGH PRESSURE BECOMES
REESTABLISHED OVER THE GULF COAST.
24
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 76 93 75 94 77 / 40 30 10 20 10
KBPT 76 93 74 94 77 / 40 20 10 20 10
KAEX 73 94 69 95 74 / 40 20 10 10 10
KLFT 76 92 74 95 76 / 40 30 10 20 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1136 PM EDT SUN AUG 12 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH OF THE REGION OVERNIGHT. A WEAK RIDGE
OF HIGH PRESSURE WILL MOVE ACROSS THE AREA MONDAY INTO TUESDAY THEN
ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL APPROACH
ON WEDNESDAY FROM CENTRAL CANADA.&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...DELAYED ONSET OF FOG OVERNIGHT ACROSS CENTRAL PARTS OF
THE CWA. ALSO MADE SOME MINOR CHANGES TO POPS BASED ON CURRENT RADAR.
PREVIOUS DISCUSSION... LOW PRESSURE WILL MOVE INTO CENTRAL QUEBEC
PROVINCE TONIGHT THEN WEAKEN MONDAY. HAVE BASED POPS INTO THIS
EVENING ON RUC13 THEN TRANSITION TO THE A BLEND OF THE
NAM12...GFS40...CMCREG AND ECMWF. FOR TEMPERATURE AND DEW POINT
HAVE USED THE GMOS. QPF BASED ON THE A BLEND OF THE NAM12 AND
GFS40. ATMOSPHERE LOOKS STABLE OVER EASTERN MAINE SO WILL REMOVE
MENTION OF THUNDER THIS EVENING AFTER 0000Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
LGT WINDS WITH A WEAK SFC PRES GRAD AND AT LEAST PARTIALLY CLR
SKIES MON NGT ACROSS THE FA SHOULD ALLOW FOR ENOUGH RADIATIONAL
COOLING TO RESULT IN PATCHY VALLEY FOG LATE IN THE PD.
MOST IF NOT ALL OF THIS FOG SHOULD BURN OFF SHORTLY AFT SUNRISE
TUE ALLOWING FOR INTERVALS OF CLDS AND SUNSHINE ACROSS THE FA ALG
WITH WARM AFTN HI TEMPS MSLY IN THE LOWER TO MID 80S...XCPT COOLER
ALG THE IMMEDIATE COAST. THE STRENGTH OF THE S/WV RIDGE ALF SHOULD
MSLY PREVENT TSTM DEVELOPMENT...SO WE LOWERED POPS TO THE SLGT CHC
CAT MAINLY ACROSS NRN/WRN PTNS OF THE FA FOR THE AFTN AND EVE HRS.
MEANWHILE...A STRONGER S/WV MOVG E FROM CNTRL CAN WILL BEGIN TO
BRING HI/MID CLDS TO THE FA AS ERLY AS LATE TUE NGT. DUE TO THE
SLIGHTLY FASTER ARRIVAL OF THE S/WV THAN SHOWN IN MODELS YSTDY
ATTM...WE HELD OFF ON ANY FOG MENTION IN OUR FA LATE TUE NGT FOR
NOW. OTHERWISE...SHWRS COULD ARRIVE INTO WRN PTNS OF THE FA WED
MORN AND INTENSIFY TO TSTMS OVR CNTRL AND ERN PTNS OF THE FA WED
AFTN WITH MAX POTENTIAL AFTN SB CAPES OF 1000-1500 J/KG BASED ON
SREF PROJECTIONS WITH OPNL GFS/NAM PROJECTIONS UPWARDS OF 1500-
2000 J/KG LIKELY TO HI GIVEN CURRENT PROJECTIONS OF LMTD SUNSHINE
ON WED. FOR THIS REASON...WE WILL NOT BE INCLUDING ANY ENHANCED
TSTM WORDING IN OUR GRIDS FOR WED AFTN ATTM. HOWEVER...CONSENSUS
OF DIFFERENT MODEL 6 HRLY QPF PROJECTIONS FAVORED GOING UP TO LOW
CAT POPS SPCLY W...N AND CNTRL PTNS OF THE FA WED AFTN WITH LIKELY
POPS OVR DOWNEAST AREAS AND CHC POPS OVR THE WATERS.
AFT MILD OVRNGT LOWS TUE NGT...HI TEMPS WED WILL LIKELY BE HELD
BACK BY CLD CVR...SPCLY OVR NRN AND WRN PTNS OF THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
UNSETTLED CONDITIONS WILL CONTINUE THROUGH THE END OF THE WEEK INTO
THE WEEKEND AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER
TROUGH. RIGHT OFF THE BAT, THE FORECAST MODELS ARE HAVING TROUBLE
AGREEING ON THE HANDLING OF THIS TROUGH AND THE SHORTWAVES THAT WILL
TRAVERSE AROUND ITS PERIPHERY. WHILE THE GFS AND ECMWF BOTH HAVE A
CLOSED SHORTWAVE IN THE VICINITY OF SOUTHERN WEDNESDAY EVENING, THE
GFS OPENS THE WAVE UP WEDNESDAY NIGHT AND SHUNTS IT EASTWARD
THURSDAY. THIS ALLOWS A BRIEF RIDGE TO BUILD OVER NEW ENGLAND
THURSDAY INTO EARLY FRIDAY, MEANING DRY WEATHER FOR THAT TIME
PERIOD. THE GFS THEN PRODUCES SEVERAL ROUNDS OF SHOWERS OVER THE
STATE THROUGH THE WEEKEND AS WAVES MOVE THROUGH THE SOUTHWEST FLOW
ALOFT AHEAD OF THE MAIN UPPER LOW. MEANWHILE, THE ECMWF CUTS OFF THE
FIRST UPPER SHORTWAVE WEDNESDAY NIGHT AND THEN SLOWLY MOVES IT EAST
TO NOVA SCOTIA BY SATURDAY MORNING. ONLY THEN DOES IT SHOW SOME
RIDGING AT THE SURFACE AND ALOFT, FRIDAY NIGHT THROUGH SUNDAY. WHILE
THIS SOLUTION WOULD FAVOR A MAINLY DRY WEEKEND, THE UPPER LOW WILL
STILL BE CLOSE ENOUGH TO PRODUCE SCATTERED SHOWERS EACH AFTERNOON.
GIVEN THESE DISCREPANCIES, HAVE GONE WITH A CHANCE OF SHOWERS
EACH DAY OF THE LONG TERM PERIOD.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
NEAR TERM: EXPECT IFR CONDITIONS TONIGHT INTO MONDAY.
SHORT TO LONG TERM: GENERALLY VFR ALL TAF SITES XCPT MVFR/IFR IN
LATE NGT PATCHY FOG LATE TUE NGT AND IN TSTMS AND HEAVIER SHWRS
MSLY WED INTO WED NGT. PREVAILING VFR THEREAFTER WITH MVFR
POSSIBLE IN SCATTERED SHOWERS POSSIBLE EACH DAY THROUGH THE
WEEKEND.
&&
.MARINE...
NEAR TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 TO INITIALIZE
THE WIND GRIDS WILL LOWER MODEL WINDS SPEEDS ABOUT 50 PERCENT TO
BETTER FIT BUOY OBSERVATIONS. LATE THIS EVENING INTO MONDAY WILL
LOWER MODEL BLEND WINDS BY 20 PERCENT TO ADJUST FOR STRONG MARINE
LAYER. FOR WAVES: PRIMARY WAVE GROUP IS AROUND 4 FEET FROM 195
DEGREES AT 8 SECONDS AND ORIGINATES FROM FETCH AREA SOUTH AND
EAST OF GULF OF MAINE. SECONDARY LONG PERIOD GROUP AT 1 FOOT FROM
145 DEGREES AND 10 SECONDS. EXPECT COMBINED SEA TO STAY BELOW 5
FEET SO WILL NOT ISSUE SCA FOR SEAS BUT MAY COME CLOSE TO 5 FEET
FOR A FEW HOURS THIS EVENING. WILL USE NAM/SWAN FOR WAVES. STILL
DENSE FOG ACROSS COASTAL WATERS SO WILL KEEP AREAS OF FOG WITH
VISIBILITY BELOW 1 MILE THROUGH MONDAY MORNING THEN TRANSITION TO
PATCHY FOG IN AFTERNOON.
SHORT TERM: NO HDLNS ANTICIPATED THRU THE SHORT TERM. STABLE
SFC-500M AGL LAPSE RATES WILL PRECLUDE MUCH IN THE WAY OF MIXING
AND WIND SPEEDS ABV 12 KT. TDYS 12Z WW3 WV GUIDANCE WAS NOT TO
HIGH OVR OUTER WATERS...SO WE ONLY LOWERED IT BY 10-15 PERCENT OVR
OPEN WATERS AND LOWERED IT TO 1 TO 2 FT NEAR THE COASTLINE AND
INNER BAYS/HARBORS. WITH LITTLE IN THE WAY OF OFFSHORE WINDS MON
NGT TO BRING DRIER AIR OVR THE WATERS...WE KEPT A MENTION OF
PATCHY FOG OVR OUR MZS DURG THIS PD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...FITZSIMMONS/MIGNONE
SHORT TERM...VJN
LONG TERM...HASTINGS
AVIATION...FITZSIMMONS/MIGNONE
MARINE...FITZSIMMONS/MIGNONE/VJN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
936 PM EDT SUN AUG 12 2012
.SYNOPSIS...
LOW PRESSURE WILL MOVE NORTH OF THE REGION OVERNIGHT. A WEAK RIDGE
OF HIGH PRESSURE WILL MOVE ACROSS THE AREA MONDAY INTO TUESDAY THEN
ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL APPROACH
ON WEDNESDAY FROM CENTRAL CANADA.&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...REMOVED MENTION OF THUNDERSTORMS FOR THIS EVENING AS THEY HAVE
DIMINISHED AT THIS HOUR. ALSO MADE SOME FAIRLY MINOR ADJUSTMENTS
TO POP AND QPF BASED ON RADAR.
PREVIOUS DISCUSSION... LOW PRESSURE WILL MOVE INTO CENTRAL QUEBEC
PROVINCE TONIGHT THEN WEAKEN MONDAY. HAVE BASED POPS INTO THIS
EVENING ON RUC13 THEN TRANSITION TO THE A BLEND OF THE
NAM12...GFS40...CMCREG AND ECMWF. FOR TEMPERATURE AND DEW POINT
HAVE USED THE GMOS. QPF BASED ON THE A BLEND OF THE NAM12 AND
GFS40. ATMOSPHERE LOOKS STABLE OVER EASTERN MAINE SO WILL REMOVE
MENTION OF THUNDER THIS EVENING AFTER 0000Z.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
LGT WINDS WITH A WEAK SFC PRES GRAD AND AT LEAST PARTIALLY CLR
SKIES MON NGT ACROSS THE FA SHOULD ALLOW FOR ENOUGH RADIATIONAL
COOLING TO RESULT IN PATCHY VALLEY FOG LATE IN THE PD.
MOST IF NOT ALL OF THIS FOG SHOULD BURN OFF SHORTLY AFT SUNRISE
TUE ALLOWING FOR INTERVALS OF CLDS AND SUNSHINE ACROSS THE FA ALG
WITH WARM AFTN HI TEMPS MSLY IN THE LOWER TO MID 80S...XCPT COOLER
ALG THE IMMEDIATE COAST. THE STRENGTH OF THE S/WV RIDGE ALF SHOULD
MSLY PREVENT TSTM DEVELOPMENT...SO WE LOWERED POPS TO THE SLGT CHC
CAT MAINLY ACROSS NRN/WRN PTNS OF THE FA FOR THE AFTN AND EVE HRS.
MEANWHILE...A STRONGER S/WV MOVG E FROM CNTRL CAN WILL BEGIN TO
BRING HI/MID CLDS TO THE FA AS ERLY AS LATE TUE NGT. DUE TO THE
SLIGHTLY FASTER ARRIVAL OF THE S/WV THAN SHOWN IN MODELS YSTDY
ATTM...WE HELD OFF ON ANY FOG MENTION IN OUR FA LATE TUE NGT FOR
NOW. OTHERWISE...SHWRS COULD ARRIVE INTO WRN PTNS OF THE FA WED
MORN AND INTENSIFY TO TSTMS OVR CNTRL AND ERN PTNS OF THE FA WED
AFTN WITH MAX POTENTIAL AFTN SB CAPES OF 1000-1500 J/KG BASED ON
SREF PROJECTIONS WITH OPNL GFS/NAM PROJECTIONS UPWARDS OF 1500-
2000 J/KG LIKELY TO HI GIVEN CURRENT PROJECTIONS OF LMTD SUNSHINE
ON WED. FOR THIS REASON...WE WILL NOT BE INCLUDING ANY ENHANCED
TSTM WORDING IN OUR GRIDS FOR WED AFTN ATTM. HOWEVER...CONSENSUS
OF DIFFERENT MODEL 6 HRLY QPF PROJECTIONS FAVORED GOING UP TO LOW
CAT POPS SPCLY W...N AND CNTRL PTNS OF THE FA WED AFTN WITH LIKELY
POPS OVR DOWNEAST AREAS AND CHC POPS OVR THE WATERS.
AFT MILD OVRNGT LOWS TUE NGT...HI TEMPS WED WILL LIKELY BE HELD
BACK BY CLD CVR...SPCLY OVR NRN AND WRN PTNS OF THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
UNSETTLED CONDITIONS WILL CONTINUE THROUGH THE END OF THE WEEK INTO
THE WEEKEND AS THE REGION REMAINS UNDER THE INFLUENCE OF AN UPPER
TROUGH. RIGHT OFF THE BAT, THE FORECAST MODELS ARE HAVING TROUBLE
AGREEING ON THE HANDLING OF THIS TROUGH AND THE SHORTWAVES THAT WILL
TRAVERSE AROUND ITS PERIPHERY. WHILE THE GFS AND ECMWF BOTH HAVE A
CLOSED SHORTWAVE IN THE VICINITY OF SOUTHERN WEDNESDAY EVENING, THE
GFS OPENS THE WAVE UP WEDNESDAY NIGHT AND SHUNTS IT EASTWARD
THURSDAY. THIS ALLOWS A BRIEF RIDGE TO BUILD OVER NEW ENGLAND
THURSDAY INTO EARLY FRIDAY, MEANING DRY WEATHER FOR THAT TIME
PERIOD. THE GFS THEN PRODUCES SEVERAL ROUNDS OF SHOWERS OVER THE
STATE THROUGH THE WEEKEND AS WAVES MOVE THROUGH THE SOUTHWEST FLOW
ALOFT AHEAD OF THE MAIN UPPER LOW. MEANWHILE, THE ECMWF CUTS OFF THE
FIRST UPPER SHORTWAVE WEDNESDAY NIGHT AND THEN SLOWLY MOVES IT EAST
TO NOVA SCOTIA BY SATURDAY MORNING. ONLY THEN DOES IT SHOW SOME
RIDGING AT THE SURFACE AND ALOFT, FRIDAY NIGHT THROUGH SUNDAY. WHILE
THIS SOLUTION WOULD FAVOR A MAINLY DRY WEEKEND, THE UPPER LOW WILL
STILL BE CLOSE ENOUGH TO PRODUCE SCATTERED SHOWERS EACH AFTERNOON.
GIVEN THESE DISCREPANCIES, HAVE GONE WITH A CHANCE OF SHOWERS
EACH DAY OF THE LONG TERM PERIOD.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: EXPECT IFR CONDITIONS TONIGHT INTO MONDAY.
SHORT TO LONG TERM: GENERALLY VFR ALL TAF SITES XCPT MVFR/IFR IN
LATE NGT PATCHY FOG LATE TUE NGT AND IN TSTMS AND HEAVIER SHWRS
MSLY WED INTO WED NGT. PREVAILING VFR THEREAFTER WITH MVFR
POSSIBLE IN SCATTERED SHOWERS POSSIBLE EACH DAY THROUGH THE
WEEKEND.
&&
.MARINE...
NEAR TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 TO INITIALIZE
THE WIND GRIDS WILL LOWER MODEL WINDS SPEEDS ABOUT 50 PERCENT TO
BETTER FIT BUOY OBSERVATIONS. LATE THIS EVENING INTO MONDAY WILL
LOWER MODEL BLEND WINDS BY 20 PERCENT TO ADJUST FOR STRONG MARINE
LAYER. FOR WAVES: PRIMARY WAVE GROUP IS AROUND 4 FEET FROM 195
DEGREES AT 8 SECONDS AND ORIGINATES FROM FETCH AREA SOUTH AND
EAST OF GULF OF MAINE. SECONDARY LONG PERIOD GROUP AT 1 FOOT FROM
145 DEGREES AND 10 SECONDS. EXPECT COMBINED SEA TO STAY BELOW 5
FEET SO WILL NOT ISSUE SCA FOR SEAS BUT MAY COME CLOSE TO 5 FEET
FOR A FEW HOURS THIS EVENING. WILL USE NAM/SWAN FOR WAVES. STILL
DENSE FOG ACROSS COASTAL WATERS SO WILL KEEP AREAS OF FOG WITH
VISIBILITY BELOW 1 MILE THROUGH MONDAY MORNING THEN TRANSITION TO
PATCHY FOG IN AFTERNOON.
SHORT TERM: NO HDLNS ANTICIPATED THRU THE SHORT TERM. STABLE
SFC-500M AGL LAPSE RATES WILL PRECLUDE MUCH IN THE WAY OF MIXING
AND WIND SPEEDS ABV 12 KT. TDYS 12Z WW3 WV GUIDANCE WAS NOT TO
HIGH OVR OUTER WATERS...SO WE ONLY LOWERED IT BY 10-15 PERCENT OVR
OPEN WATERS AND LOWERED IT TO 1 TO 2 FT NEAR THE COASTLINE AND
INNER BAYS/HARBORS. WITH LITTLE IN THE WAY OF OFFSHORE WINDS MON
NGT TO BRING DRIER AIR OVR THE WATERS...WE KEPT A MENTION OF
PATCHY FOG OVR OUR MZS DURG THIS PD.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...FITZSIMMONS/MIGNONE
SHORT TERM...VJN
LONG TERM...HASTINGS
AVIATION...FITZSIMMONS/MIGNONE
MARINE...FITZSIMMONS/MIGNONE/VJN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT SAT AUG 11 2012
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 407 PM EDT SAT AUG 11 2012
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL LOW OVER SRN
ONTARIO...JUST WEST OF TORONTO...SLOWLY LIFTING TO THE NORTHEAST.
UPSTREAM...A SHORTWAVE TROUGH WAS LOCATED OVER SE MT LEAVING WEAK
RIDGING FROM MN INTO WRN LAKE SUPERIOR. AT THE SFC...A RIDGE EXTENDED
FROM JAMES BAY THROUGH NE MN INTO IA AHEAD OF A TROUGH OVER THE WRN
PLAINS.
TONIGHT...AS HIGH PRES BUILDS INTO THE REGION AND DAYTIME HEATING
FADES...ANY REMAINING CU WILL DIMINISH THIS EVENING. THE AIRMASS
WILL ALSO BE RELATIVELY DRY WITH PWAT VALUES AOB 0.50 INCH.
WITH FAVORABLE RADIATIONAL COOLING CONDITIONS TONIGHT...LOW TEMPS
WILL DROP TO THE LOWER 40S OVER THE INTERIOR W...WITH LOWS AROUND 50
OVER THE INTERIOR E. NEAR THE GREAT LAKES SHORES...LOWS WILL BE IN
THE 50S TO NEAR 60. CANNOT RULE OUT SOME GROUND FOG AGAIN OVER THE WEST
BUT SHOULD BE PATCHY/ISOLATED.
SUNDAY...THE MODELS WERE CONSISTENT IN KEEPING THE PLAINS SHORTWAVE
FAR ENOUGH TO THE SOUTHWEST OF THE CWA TO KEEP UPPER MI DRY. EVEN
THOUGH THERE WILL BE INCREASING OVER THE WEST HALF DURING THE
AFTERNOON ON THE NRN FRINGE OF THE SHRTWV FORCING...A DECENT AMOUNT OF
SUNSHINE ALONG WITH WEAK WA WILL HELP PUSH TEMPS BACK INTO THE MID
TO UPPER 70S.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 407 PM EDT SAT AUG 11 2012
UPPER MS VALLEY UPPER TROUGH WILL CROSS THE UPPER GREAT LAKES SUNDAY
NIGHT INTO MONDAY. MOISTURE WILL BE LIMITED AND BEST FORCING WILL
BE WELL SOUTH OF THE AREA CLOSER TO THE SURFACE LOW TRACKING ACROSS
NORTHERN IL INTO LOWER MI. WILL KEEP LOW CHANCE POPS ACROSS THE
AREA LATE SUNDAY NIGHT THROUGH MONDAY. LAKE BREEZES COULD BE THE
FOCUS FOR SOME ADDED SHRA AND ISOLATED TSRA DEVELOPMENT MONDAY
AFTERNOON.
SURFACE LOW WILL CONTINUE EAST INTO SOUTHERN ONTARIO ON TUESDAY WITH
HIGH PRESSURE BUILDING INTO WEST AND CENTRAL UPPER MI. RIDGE AXIS
WILL PASS OVER THE AREA EARLY WEDNESDAY WITH WINDS TURNING TO THE
SOUTHWEST DURING THE AFTERNOON. WITH PLENTY OF SUNSHINE THIS SHOULD
BE THE WARMEST DAY OF THE WEEK WITH TEMPS NEAR 80 IN MANY AREAS.
NEXT UPPER TROUGH AND COLD FRONT WILL BEGIN TO APPROACH THE AREA
FROM THE WEST BY LATE IN THE DAY INTO WEDNESDAY NIGHT. THIS SHOULD
OFFER UP A DECENT CHANCE OF RAIN ACROSS MUCH OF THE AREA AHEAD OF
THE FRONT. SEVERE WEATHER CHANCES APPEAR TO BE MINIMAL BUT EXPECT AT
LEAST A BROKEN BAND OF SHOWERS AND THUNDERSTORMS ALONG AND AHEAD OF
THE FRONT FROM WEDNESDAY NIGHT INTO THURSDAY.
AFTER THE FRONT PASSES AND WINDS TURN NORTHWESTERLY...DECENT COLD
ADVECTION WILL LOWER 85H TEMPS INTO THE 2-4C RANGE. THUS...EXPECT
SOME EARLY FALL LIKE CONDITIONS WITH POST FRONTAL LAKE EFFECT CLOUDS
AND EVEN SOME LAKE INDUCED SHRAS FROM LATE THURSDAY INTO FRIDAY.
SURFACE RIDGE AXIS WILL PASS OVER THE AREA ON SATURDAY WITH A
MODERATING TREND BEGINNING THEREAFTER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 134 PM EDT SAT AUG 11 2012
UNDER DRY AIR MASS ASSOCIATED WITH HIGH PRES DRIFTING INTO THE UPPER
LAKES...EXPECT PREDOMINANT VFR CONDITIONS THROUGH THE FCST PERIOD AT
ALL TAF SITES. THERE MAY BE SOME GROUND FOG AT KIWD...SIMILAR TO
LAST NIGHT...BUT SHOULD BE BRIEF/INTERMITTENT. CONFIDENCE IS ALSO
LIMITED THAT ANY WILL OCCUR SO WAS NOT INCLUDED AT THIS TIME.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE) ISSUED AT
407 PM EDT SAT AUG 11 2012
AS HIGH PRESSURE BUILDS INTO THE REGION...WINDS WILL SLOWLY DIMINISH
THROUGH TONIGHT. WINDS SUN THRU WED WILL BE MOSTLY 15KT OR LESS AS
ONLY WEAK SYSTEMS AFFECT THE AREA. A FALL-LIKE LOW PRESSURE SYSTEM
AND FRONT MOVING THROUGH LAKE SUPERIOR THURSDAY COULD PRODUCE
STRONGER NW WINDS INTO THE 20-30 KT RANGE FROM THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
340 PM EDT SAT AUG 11 2012
.SHORT TERM...THIS EVENING AND TONIGHT
THE CLOSED CIRCULATION OF THE BAROTROPIC UPPER LEVEL PRESSURE SYSTEM
REMAINS CENTERED OVER PORTIONS OF FAR SOUTHWESTERN ONTARIO THIS
AFTERNOON. THIS POSITIONING FOR THE PAST 6HRS SEEMS TO HAVE BEEN A
RESULT OF A LAKE AGGREGATE EFFECT OFF OF THE CENTROID OF THE CENTRAL
GREAT LAKES. THE EFFECTIVE REACH OF THE LOW HAS BEEN GREAT ENOUGH TO
KEEP THE ENTIRETY OF EASTERN LOWER MICHIGAN UNDER A VEIL OF LOW TO
MIDLEVEL STRATUS. EROSION OF THE WESTERN EDGE OF THE CLOUDS IS
TAKING PLACE AS WE/RE CURRENTLY SEEING SOME CELLULAR BASED CLOUD
SCALE CIRCULATIONS/SUBSIDENCE BRINGING SOME INCREASED SUNSHINE AT
THE WESTERN CWA DOORSTEP. EVEN IF THIS OCCURS...TIME IS RUNNING OUT
TO SALVAGE MUCH IF ANY OF THE TODAY PERIOD. MAY SEE A 3-5 DEGREE
SPIKE IF THAT OCCURS...MERELY PUTTING US AT THE FORECASTED HIGH
VALUES FOR TODAY.
SUBTLE TROUGH AXIS WILL PUSH TO THE LAKE ERIE APPENDAGE PRIOR TO
00Z. THIS WILL OFFER ADDITIONAL SUPPORT FOR A CONTINUATION OF THE
GRADIENT FLOW RIGHT UP TO THE ADVENT OF THE EVENING ALONG WITH THE
SUBSEQUENT EVAPORATION/DRYING OF THE LOW LEVEL TROPOSPHERE.
SOUTHEASTERN MICHIGAN WILL RESIDE IN A GENERAL AREA OF DIFFERENTIAL
AVA THROUGH THE EVENING HOURS PER RAP-FORMERLY RUC. THIS RAP DATASET
ALSO SEEMS TO HAVE A REASONABLE HANDLE OF THE CYCLONIC VORTICITY
FILAMENT NOW EXITING THE FAR EAST. THUS...FOR THE REMAINDER OF THE
AFTERNOON/EARLY EVENING WILL BE LOOKING AT POTENTIAL FOR SMALLISH
WAVES OF LIGHT SHOWERS/DRIZZLE BUT NOT ANTICIPATING MUCH IN THE WAY
OF WIDESPREAD HEAVY PRECIPITATION. LOSS OF INSOLATION THIS EVENING
SHOULD SHUT EVERYTHING DOWN WITH TIME. ELEVATED LEVELS OF NEAR
SURFACE MOISTURE BRINGS PROSPECTS OF FOG TOWARDS MORNING ESPECIALLY
IF CLOUD COVER TOTALLY DISSIPATES. NOT SEEING A GREAT MODELED
MOISTURE PROFILE FOR FOG TONIGHT AND WILL LEAVE PATCHY MENTION IN
THE GRIDS...BEST POTENTIAL SHOULD BE IN LOW LYING AREAS. LACK OF
ADVECTION WILL LIKELY KEEP LOWS IN THE MIDDLE TO UPPER 50S.
&&
.LONG TERM...SUNDAY THROUGH SATURDAY
ACTIVE WEATHER PATTERN WILL CONTINUE DURING THE UPCOMING WEEK WITH
TWO MAJOR SYSTEM SLATED TO TRAVEL THROUGH THE GREAT LAKES...BOTH
BRINGING THE CHANCE OF WIDESPREAD RAINFALL. THESE SYSTEMS WILL BE
TRACKING INTO THE AREA WITHIN MEAN NORTHWEST UPPER FLOW...WITH THIS
PATTERN ESSENTIALLY KEEPING TEMPERATURES NEAR AVERAGE FOR WARMEST
DAYS IMMEDIATELY PRECEDING THESE STORM SYSTEMS AS SHORTWAVE RIDGING
TRANSLATES THROUGH THE AREA TO BELOW AVERAGE AFTER IN THE WAKE OF
THESE SYSTEMS AS COLD AIR ADVECTION AND RESIDUAL MOISTURE AND CLOUD
COVER HOLDS TEMPERATURES DOWN. THE COOLEST AIRMASS WILL HOLD OFF
UNTIL LATE IN THE FORECAST PERIOD AS SECOND SHORTWAVE TAPS A FAIR
AMOUNT OF FALL-LIKE AIR AS IT DROPS ACROSS CANADA INTO THE LAKES
REGION.
THE FIRST SHORTWAVE IS EVIDENT ON WATER VAPOR IMAGERY CHURNING EAST
ACROSS THE US ROCKIES NEAR THE MONTANA AND WYOMING STATE LINE. ITS
COUNTERPART IS ANOTHER SHORTWAVE WHICH IS TRACKING OVER THE CANADIAN
ROCKIES. BOTH VORTICITY CENTERS ARE QUITE WELL DEVELOPED ALREADY.
THE POSITIONING OF THE SOUTHERN SHORTWAVE WILL FAVOR AN EVENTUAL
TRACK OF THE MAIN ENERGY ACROSS THE NORTHERN OHIO VALLEY/SOUTHERN
GREAT LAKES...WHICH WILL BE FAVORABLE FOR A FAIRLY WIDESPREAD AND
STEADY RAIN ACROSS THE AREA. MODELS HAVE REMAINED RATHER CONSISTENT
RUN TO RUN AS WELL AS IN RESPECT TO EACH OTHER IN BRINGING THIS
STORM SYSTEM INTO THE AREA LATE MONDAY...HAVING THE BULK OF THE
RESULTING PRECIPITATION EVENT OCCUR MONDAY NIGHT...AND THEN HOLDING
ONTO LINGERING SHOWERS INTO TUESDAY. WILL NOT ADJUST FORECAST MUCH
OTHER THAN TO INCREASE PRECIPITATION CHANCES SLIGHTLY AS CONFIDENCE
IN THIS SCENARIO CONTINUES TO INCREASE.
THE SECOND SYSTEM...STILL WELL OFF THE CANADIAN WEST COAST...WILL
EVENTUALLY COME ONSHORE OVER BRITISH COLUMBIA AND TAP A LARGER CHUNK
OF COLDER AIR AS THE NORTHERN STREAM COMPONENT OF THE JET ENERGY
REMAINS DOMINANT AS IT CROSS NOAM. THIS WILL RESULT IN A SURFACE LOW
TRACKING THROUGH SOUTHERN CANADA AND JUST BRUSHING THE NORTHERN
GREAT LAKES. THIS LOW WILL FORCE A STRONG COLD FRONT THROUGH THE
GREAT LAKES AS IT WRAPS UP INTO THE JAMES BAY/HUDSON BAY AREA. THE
TIMING IS SLIGHTLY MORE ELUSIVE...BUT FOR A DAY 6/7 FORECAST...THE
CONFIDENCE REMAINS HIGHER THAN NORMAL AS MODELS SUGGEST A THURSDAY
NIGHT INTO FRIDAY TIME FRAME. THIS SCENARIO...WITH THE MAIN SYSTEM
NORTH OF THE REGION...SUPPORTS A LINE OR LINES OF CONVECTION IN
ADVANCE OR WITH THE COLD FRONTAL PASSAGE...FOLLOWED BY WRAPAROUND
MOISTURE AND EVEN SOME LAKE EFFECT/ENHANCED SHOWER ACTIVITY HEADING
INTO THE WEEKEND AS THE COOLER AIR INTERACTS WITH RELATIVELY WARM
LAKE WATERS. SO...OVERALL...WHILE RAIN CHANCES LOOK PRETTY GOOD AT
THIS POINT...THIS ACTIVITY WILL BE SHORTER LIVED AND MORE SCATTERED
IN NATURE THAN THE SYSTEM EARLY IN THE WEEK.
AS ELUDED TO EARLIER...TEMPERATURES WILL OSCILLATE BETWEEN AVERAGE
AND BELOW AVERAGE WITH THE APPROACH AND THEN DEPARTURE OF THESE
STORM SYSTEMS. THIS WILL BRING HIGH TEMPERATURES AROUND 80 EARLY IN
THE WEEK AND AGAIN WEDNESDAY/THURSDAY...WITH HIGHS CLOSER TO 70
TUESDAY AND 70 OR LESS FRIDAY INTO SATURDAY. LOWS WILL RANGE IN THE
UPPER 50S TO LOWER 60S UNTIL THE LAST PART OF THE FORECAST PERIOD
WHEN LOWS AROUND 50 WILL BE MORE COMMON AS THE COLDER AIRMASS SPILLS
INTO THE AREA. IN FACT...A FEW READINGS IN THE 40S SEEM PROBABLE BY
NEXT WEEKEND IF THE CURRENT BASIC STORM TRACK SCENARIO HOLDS CLOSE
TO CURRENT PROJECTIONS.
&&
.MARINE...
THE BROAD LOW PRESSURE CENTER CIRCULATION IS IN PLACE OVER FAR
SOUTHERN LAKE HURON THIS AFTERNOON. OVERALL...THE WEAK SFC LOW
FEATURE HAS KEPT CONDITIONS RELATIVELY IN CHECK GIVEN THE ANOMALOUS
PARENT UPPER LEVEL SYSTEM. THE AREA WATERS ARE EXPERIENCE SOME LOW
STABILITY CONDITIONS WHICH WILL MAINTAIN THE RESIDUAL CHOPPY SEA
STATE THROUGH THE TONIGHT PERIOD. THIS IS HANDLED IN THE NEARSHORE
ZONES WITH SMALL CRAFT ADVISORIES THAT ARE IN EFFECT UNTIL 2Z THIS
EVENING. WAVE HEIGHTS SHOULD TRANSLATE QUICKLY AWAY FROM THE US
WATERS OVERNIGHT...AND THE DECISION WAS MADE TO MAINTAIN THE
INHERITED TIMING OF HEADLINES. BUILDING HIGH PRESSURE WILL BRING
MUCH CALMER CONDITIONS LATE SUNDAY AND SUNDAY NIGHT. AN APPROACHING
TROUGH OF LOW PRESSURE WILL ADVANCE INTO THE GREAT LAKES REGION BY
MONDAY NIGHT...POTENTIALLY SUPPORTING A SURFACE LOW CENTER THAT
WOULD TRACK THROUGH SOUTHEASTERN MICHIGAN ON TUESDAY.
AVAILABLE MODEL GUIDANCE IS NOT VERY STRONG WITH THE LAKE EFFECT
POTENTIAL OF SHOWERS AND TSTORMS OVERNIGHT. WITH THAT SAID...PATTERN
RECOGNITION SUGGESTS CONVECTION WILL BE POSSIBLE THROUGHOUT THE
NIGHT. GIVEN THE STABILITY AND VORTICITY RICH
ENVIRONMENT....WATERSPOUTS WILL BE POSSIBLE WITH ANY ACTIVITY.
&&
.AVIATION...ISSUED 128 PM EDT SAT AUG 11 2012
//DISCUSSION...
A MOIST/SATURATED ENVIRONMENT REMAINS IN PLACE ACROSS ALL OF
SOUTHEASTERN MICHIGAN AS THE BAROTROPIC LOW STRUCTURE IS NOW
CENTERED DIRECTLY EAST OF THE FORECAST AREA. HAVE BEEN WITNESSING
ON MSLP SFC ANALYSIS AND SATELLITE IMAGERY SIGNS THE LOW IS
FAVORING THE CENTRAL GREAT LAKES REGION AS AN AGGREGATE EFFECT.
SOUTHEASTERN MICHIGAN RESIDES ON THE WESTERN PERIPHERY IN
NORTHERLY FLOW SECTOR...WHICH MEANS PERIODS OF LIGHT SHOWERS AS
WAVES OF WRAP AROUND MOISTURE WORK THROUGH. THE ONLY REAL ISSUE TO
WATCH FOR IS ANY HEAVIER SHOWER/ISOLATED TSTORM DEVELOPMENT WITH
ANY BREAKS IN THE CLOUDS AND BRIEF SHOT OF INSOLATION. CONFIDENCE
IN THIS OCCURRING REMAINS LOW. LOSS OF INSOLATION THIS
EVENING...COMBINED WITH RISING HEIGHTS SHOULD YIELD TO BUILDING
SURFACE HIGH PRESSURE AND A DISSIPATION IN MVFR/VFR TYPE
CLOUDS.THE TIMING CONFIDENCE ON THIS REMAINS SHAKY GIVEN PATTERN
RECOGNITION.
//DTW THRESHOLD THREATS...
* HIGH CONFIDENCE CEILINGS WILL REMAIN BELOW 5000 FT THROUGH THE
AFTERNOON.
* VERY LOW CONFIDENCE WITH A THUNDERSTORM AFFECTING DTW TODAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...
SMALL CRAFT ADVISORY...INNER SAGINAW BAY...UNTIL 4 PM SATURDAY.
SMALL CRAFT ADVISORY...OUTER SAGINAW BAY AND THE NEARSHORE WATERS
FROM PORT AUSTIN TO PORT SANILAC...UNTIL 10 PM SATURDAY.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....DG
MARINE.......CB
AVIATION.....CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1050 PM CDT SUN AUG 12 2012
.UPDATE...
06Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
PRIMARY FORECAST CONCERNS ARE THE SHORTWAVE AND ASSOCIATED PCPN
CURRENTLY AFFECTING THE AREA... AND A DECENT UPPER WAVE AND COLD
FRONT EXPECTED TO IMPACT THE REGION ON WEDNESDAY. ON THE BIG
PICTURE... EXPECTATIONS HAVE NOT CHANGED MUCH... WITH A GENERAL
COOLING TREND EXPECTED TO CONTINUE AS THE UPPER RIDGE IS DISPLACED
WEST FOR MOST OF THE WEEK. THE ONLY EXCEPTION BEING A BRIEF PUSH
OF HIGHER HEIGHTS INTO THE AREA MIDWEEK PRIOR TO THE SHORTWAVE
DROPPING IN ON WEDNESDAY AND REASSERTING THE EASTERN TROUGH. ONCE
WE MOVE INTO NEXT WEEKEND AND THE BEGINNING OF NEXT WEEK THINGS
ARE NOT AS CLEAR... WITH THE ECMWF KEEPING THE RIDGE WELL TO OUR
WEST WHILE THE GFS STARTS TO PUSH IT EAST ONCE AGAIN. THE
ENSEMBLES SHOW QUITE A BIT OF SPREAD AFTER THURSDAY... SO DON/T
HAVE TOO MUCH CONFIDENCE IN EITHER PARTICULAR IDEA AT THIS POINT
IN TIME. IN TERMS OF SENSIBLE WEATHER... THE ONLY REAL PCPN
CHANCES WILL BE TONIGHT AS THE SHORTWAVE OVER NORTHERN IOWA
CONTINUES TO PUSH EAST... THEN AGAIN FROM TUESDAY NIGHT INTO EARLY
THURSDAY AS WE INITIALLY SEE SOME DECENT WARM ADVECTION THEN HAVE
THE COLD FRONT PUSH THROUGH AS THE SURFACE LOW MOVES BY TO OUR NORTH.
SOME LINGERING MID-LEVEL FRONTOGENESIS IN THE DEFORMATION ZONE
NORTH OF THE SHORTWAVE TO OUR SOUTH WILL KEEP SOME LIGHT PCPN
GOING INTO TONIGHT... BUT WE SHOULD EVENTUALLY SEE SOME DRIER AIR
SCOUR THINGS OUT. UPPER LEVEL DIVERGENCE IN ASSOCIATION WITH A
SECONDARY JET MAX WHICH CAN BE SEEN IN WATER VAPOR IMAGERY DIVING
SOUTHEAST THROUGH CENTRAL SOUTH DAKOTA IS ALSO HELPING TO KEEP
ACTIVITY GOING ACROSS THE AREA. CLOUDS SHOULD START TO SCOUR OUT
LATER THIS EVENING INTO THE OVERNIGHT HOURS... WHICH COULD RESULT
IN FOG FORMATION OVER PORTIONS OF THE AREA... PARTICULARLY WHERE
RAINFALL WAS MORE ABUNDANT. SO... INCLUDED SOME MENTION OF FOG
OVER THE WEST AND NORTHWEST CWFA WHERE THERE IS A BIT MORE
CONFIDENCE IN CLEARING LATER THIS EVENING. LINGERED SOME POPS OVER
THE EASTERN PORTION OF THE AREA ON MONDAY WITH LINGERING DEEPER
MOISTURE AND SOME RESIDUAL MID-LEVEL FORCING SUGGESTED BY THE NAM
AND GFS. HIGH PRESSURE WILL THEN BUILD ACROSS THE ENTIRE AREA
MONDAY NIGHT... AND SLIDE EAST OF THE REGION BY TUESDAY NIGHT WITH
RETURN FLOW SETTING UP OVER THE WESTERN CWFA BY WEDNESDAY MORNING.
BROUGHT POPS IN FROM WEST TO EAST TUESDAY NIGHT AS THE WARM
ADVECTION TAKES HOLD AND SOME ELEVATED INSTABILITY WORKS INTO THE
AREA. WOULD EXPECT A DECENT CHANCE FOR SOME SHRA/TSRA ALONG THE
PERIPHERY OF THE 850MB THETA-E RIDGE AS IT MOVES INTO THE AREA
DURING THAT PERIOD OF TIME. SHOULD THEN SEE SOME BREAK IN WHATEVER
PCPN IS OCCURRING DURING THE DAY ON WEDNESDAY AS WE BREAK INTO THE
WARM SECTOR AHEAD OF THE APPROACHING COLD FRONT AND UPPER TROUGH.
THERE APPEARS TO BE AT LEAST SOME POTENTIAL FOR SEVERE WEATHER
WEDNESDAY AFTERNOON AND EVENING AS THE FRONT SWEEPS ACROSS THE
AREA... ALTHOUGH THERE ARE STILL SOME SIGNIFICANT DIFFERENCES IN
FRONTAL TIMING BETWEEN THE NAM/GFS AND ECMWF... AND THAT COULD
OBVIOUSLY IMPACT THE SEVERE WEATHER POTENTIAL. HOWEVER... WITH
MLCAPE AOA 1500 J/KG EXPECTED ALONG WITH 0-6KM BULK SHEAR AOA 35
KT... THERE IS AT LEAST THE POTENTIAL FOR STORM ORGANIZATION AND
SEVERE WEATHER... SO IT WILL BEAR WATCHING OVER THE NEXT FEW DAYS.
ANY LINGERING PCPN ON THE BACKSIDE OF WEDNESDAY/S SYSTEM TO SHOULD
CLEAR OUT OF THE AREA ON THURSDAY... LINGERING A BIT LONGER IF THE
SLOWER ECMWF SOLUTION PANS OUT. A STRONG AREA OF HIGH PRESSURE
THEN LOOKS TO BUILD IN FOR THE SECOND HALF OF THE WEEK INTO THE
WEEKEND... SO KEPT THINGS DRY BEYOND THURSDAY. IT/S POSSIBLE WE
COULD SEE SOME PCPN SNEAK BACK INTO THE AREA BY THE SECOND PART OF
THE WEEKEND AS WE GET ON THE BACKSIDE OF THE SURFACE HIGH AND
START TO SEE SOME RETURN FLOW. BUT WITH THE GFS AND ECMWF HAVING
FAIRLY SIGNIFICANT DIFFERENCES IN THE POSITION AND AMPLITUDE OF
THE UPSTREAM RIDGE AT THAT POINT IT IS A BIT TOUGH TO HAVE MUCH
CONFIDENCE IN THOSE DETAILS AT THIS POINT... SO OPTED TO KEEP
THINGS DRY.
&&
.AVIATION.../06Z TAF ISSUANCE/
LOW CIGS AND PRECIP NOW EXITING SRN MN AND ALL TERMINALS ARE NOW
DONE WITH THAT SYSTEM WITH A WORRISOME CLEARING /FROM THE FOG
POTENTIAL PERSPECTIVE/ QUICKLY WORKING SE OUT OF WRN MN. AT 330Z...A
COLD FRONT STRETCHED FROM NEAR GRAND FORKS UP TOWARD LAKE OF THE
WOODS AND WAS MOVING SOUTH AT ONLY ABOUT 10-15 KTS. MID LEVEL
CLOUDS ASSOCIATED WITH THE FRONT WILL CERTAINLY COMPLICATE THE FOG
SITUATION THIS EVENING. AS FOR THE FOG...MOST SITES IN WRN MN HAVE
A DEWP DEPRESSION LESS THAN 5 DEGS...AND WITH RWF PICKING UP OVER
AN INCH OF RAIN OVER THE LAST 24 HOURS...FOG IS CERTAINLY A CONCERN
NOW THAT SKIES HAVE CLEARED OUT. HRRR HAS BEEN PAINTING DENSE FOG
ACROSS SW MN AS WELL FOR SEVERAL RUNS NOW...SO DID INCREASE FG
MENTION AT RWF...COULD CERTAINLY HAVE A FEW HOURS OF DENSE FOG
THERE INTO THE MORNING. ACROSS CENTRAL MN...CLOUDS COMING DOWN
WITH THE FRONT WILL COMPLICATE THE FOG SITUATION...BUT IF STC CAN
SPEND A COUPLE OF HOURS CLOUD FREE...THEY COULD EASILY GO DOWN TO
1/2SM OR LESS BEFORE FRONTAL CLOUDS SHOW UP. AS FOR
WINDS...FOLLOWED MORE OF A MET/HRRR IDEA FOR DIRECTIONS WITH THE
SLOWER FROPA GIVEN SPEED WITH WHICH FRONT IS CURRENTLY MOVING. FOR
MONDAY...CU RULE QUITE NEGATIVE BY LATE MORNING ON THE NAM...AND
EXPECT CU TO COME IN RATHER QUICKLY IN THE MORNING AND FADE DURING
THE AFTERNOON AS PROGRESSIVELY DRIER AIR WORKS IN.
KMSP...SLOWED THE ARRIVAL OF NW WINDS A BIT FROM THE GOING TAF AND
IT MAY NOT BE UNTIL CLOSER TO 15Z THAT THE FIELD TURNS OVER TO A
300 DIRECTION. WILL LIKELY CLEAR MID CLOUDS OUT FOR A BIT THIS
EVENING BEFORE FRONTAL CLOUD BAND MOVES IN...WHICH COULD ALLOW FOR
SOME VALLEY FOR THAT COULD IMPACT PARTS OF THE FIELD CLOSEST TO
THE MN RIVER VALLEY. FOR WINDS...NAM/RUC SHOWING SOME 20 KT WINDS
WITHIN 3K FT OF THE SFC IN THE MORNING...SO MAY SEE A FEW GUSTS UP
OVER 15 KTS THROUGH 20Z...BEFORE HIGH PRESSURE MOVING IN FROM THE
DAKOTAS BEGINS TO CUT BACK ON WIND SPEEDS.
OUTLOOK...
.TUESDAY...VFR. TSRA POSSIBLE LATE TUE NIGHT. VARIABLE WINDS 5 KTS.
.WEDNESDAY...CHANCE TSRA DURING THE DAY...TSRA LIKELY AT NIGHT. S
WINDS 10-20 KTS.
.THURSDAY...SHRA AND ISOLD TSRA ENDING EARLY. NW WINDS 10-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
TRH/MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
132 PM CDT SAT AUG 11 2012
.DISCUSSION...
OVERVIEW...ONLY SIGNIFICANT FORECAST CHALLENGE IN THE COMING DAYS
LIES WITH THE SYSTEM CURRENTLY MOVING INTO THE DAKOTAS...WHICH WILL
AFFECT THE SENSIBLE WEATHER IN MINNESOTA AND PERHAPS EVEN FAR
WESTERN WI OVER THE NEXT 30 HOURS. COOL AND RAINY WEATHER IS ALMOST
GUARANTEED FROM WEST CENTRAL TO SOUTH CENTRAL MINNESOTA ON SUNDAY.
CONTINUED NORTHWEST FLOW AND COOLER THAN NORMAL TEMPERATURES WILL BE
AT WORK ALL THE WAY THROUGH THE EXTENDED. AFTER SUNDAY...NEXT CHANCE
FOR RAIN DOES NOT ARRIVE UNTIL MID WEEK WHEN A SURFACE TROUGH AND
COLD FRONT PASS THROUGH THE AREA.
IF ALL GOES WELL TODAY...WE WILL HAVE OUR RADAR BACK BY THIS EVENING
AND WE CAN ALL WATCH TOGETHER AS THE RAIN SHIELD ADVANCES INTO
MINNESOTA FROM THE DAKOTAS. PROBABLY A LITTLE BIT HIGHER CONFIDENCE
WITH THE FORECAST DONE TODAY GIVEN THE TIGHTER CLUSTERING OF MODEL
SOLUTIONS COMPARED TO THE LAST COUPLE DAYS. MOST NOTABLE CHANGE
PROBABLY COMES WITH THE NORTHERN JUMP OF THE SURFACE REFLECTION IN
THE 11.12Z NAM. THE EC HAS BEEN ON THE NORTHERN SIDE OF THE MODEL
SPREAD...GFS - VERY CONSISTENTLY SOMEWHERE IN THE MIDDLE...AND THE
NAM HAS BEEN PRETTY FAR SOUTH. SO...WITH THE NORTHERN JUMP ON THE
NAM...THERE IS HIGHER CONFIDENCE IN WESTERN AND SOUTHERN MN GETTING A
SOLID 6-12 HOURS OF DEFORMATION BANDED RAINFALL.
CURRENT WATER VAPOR IMAGERY AND 500MB RUC ANALYSIS SUGGEST THE UPPER
WAVE NOW COMING OUT OF THE NORTHERN ROCKIES IS NOT BEING COMPLETELY
MISHANDLED BY EITHER THE NAM/GFS/EC. HOWEVER...WOULD HAVE TO SAY
THAT THE 11.12Z NAM/UKMET ARE PROBABLY JUST A TOUCH BETTER THAN THE
EC/GFS...WHICH HAVE THE GREATEST HEIGHT FALLS AND LOW CENTER JUST A
BIT TOO FAR TO THE NORTHEAST AT 18Z TODAY. AT ANY RATE...INCREASED
POPS TO 90-100% IN WEST CENTRAL AND SOUTH CENTRAL MN...AS IT IS HARD
TO IMAGINE A SITUATION WHERE MEASURABLE RAIN BY PASSES THESE AREAS.
THE 700MB LOW TRACK AND 850-700MB FGEN...WHICH IS QUITE GOOD...ARE
BOTH FAVORABLE FOR A WIDESPREAD 0.25" OR MORE IN THESE AREAS. THERE
IS NOT GREAT CONVECTIVE POTENTIAL...SO DON`T THINK WE WILL SEE MANY
LOCATIONS GET NEAR 1"...BUT THERE SHOULD BE A LOT OF 0.50" TOTALS IN
AREAS THAT SORELY NEED THE RAIN. STILL MEAGER MUCAPE SHOWING UP AND
IT IS AUGUST SO STILL INCLUDED SLIGHT CHANCE OF THUNDER IN THE
FORECAST.
MUCH BIGGER QUESTION MARK FOR AREAS IN EAST CENTRAL MN AND WESTERN
WI. ALTHOUGH THIS SYSTEM HAS TRENDED A BIT STRONGER AND FARTHER
NORTH...LOCATIONS ON THE NORTH SIDE OF THE BEST BANDED PRECIP MAY
ONLY END UP WITH A TENTH OR A FEW HUNDREDTH. THIS INCLUDES THE TWIN
CITIES METRO. THE 11.12Z GFS HAS A QPF BULLSEYE MUCH FURTHER NORTH
THAN MOST OF THE OTHER GUIDANCE...BUT GET THE FEELING THIS IS A
BIT AGGRESSIVE AND THAT THE LOCATION OF THE LOW LEVEL FGEN AND QG
FORCING A BIT FURTHER SOUTH WILL ANCHOR THE RAIN MORE IN WESTERN
AND SOUTHERN MN. STILL INCREASED POPS FOR THE LIKELIHOOD OF AT
LEAST A FEW HUNDREDTHS IN MANY AREAS TOMORROW.
AS MENTIONED PREVIOUSLY...WE WILL SEE BRIEF RIDGING FOR TUESDAY AS
THE NEXT STRONG TROUGH MOVES INTO THE REGION FOR WEDNESDAY
AFTERNOON/WEDNESDAY NIGHT. THERE IS MUCH BETTER CONVECTIVE
POTENTIAL WITH THIS SYSTEM. SHOULD SEE MUCH COOLER CONDITIONS
FOLLOWING THIS TROUGH INTO THE WEEKEND.
&&
.AVIATION.../18Z TAF ISSUANCE/
HIGH PRESSURE CENTERED OVER EASTERN MINNESOTA WILL SLIDE OFF TO THE
SOUTHEAST TODAY AS A LOW PRESSURE SYSTEM CURRENTLY LOCATED IN
WESTERN NEBRASKA MOVES EAST. HIGH CLOUDS MOVED INTO WESTERN
MINNESOTA THIS MORNING AND WILL ADVANCE TO EASTERN MINNESOTA BY
EVENING. THE LOW PRESSURE AREA WILL MOVE TO SOUTHWEST MINNESOTA BY
SUNRISE SUNDAY PROVIDING AN OPPORTUNITY FOR LOWER CEILINGS AND
RAIN. THE GFS MODEL WOULD LIKE TO EXTEND A LARGER PRECIPITATION
SHIELD THAN THE NAM...AM LEANING WITH THE NAM. CEILINGS IN THE
DAKOTAS HAVE BEEN ABOVE 060 FOR THE MOST PART. THE BEST CHANCES
FOR RAIN WILL BE SOUTH OF A KAXN TO KMSP LINE. SOUTH OF THIS LINE
RAIN CAN BE EXPECTED FROM EARLY MORNING THROUGH THE AFTERNOON.
CEILINGS MAY BECOME MVFR AT KRWF. OTHERWISE DO NOT EXPECT
ANYTHING LESS THAN VFR ELSEWHERE AT THIS POINT IN TIME. THE
PRECIPITATION GRADIENT MAY BE RATHER SHARP...IN FACT KMSP/KSTC/
KAXN MAY SEE MORE SPRINKLES IN THE MORNING TO EARLY AFTERNOON THAN
STEADY RAIN. WILL HAVE TO MONITOR THIS CLOSELY.
MSP...VFR THROUGH THE PERIOD. HIGH CLOUDS WILL THICKEN AND LOWER
TONIGHT THROUGH SUNDAY MORNING. GFS WOULD LIKE TO START
PRECIPITATION AROUND SUNRISE. NAM IS SLOWER AND MORE COMPACT IN
TERMS OF THE AREAL EXTENT WITH PRECIPITATION BEGINNING AT 16Z.
ELECTED TO BEGIN PRECIPITATION AT 18Z DUE TO THE VERY DRY AIRMASS
CURRENTLY IN PLACE AND BELIEF THAT IT MAY TAKE LONGER TO SATURATE
TO THE POINT OF PRECIPITATION. THERE WILL BE A SHARP INCREASE IN
PRECIPITATION CHANCES TO THE SOUTH AND A SHARP DECREASE TO THE
NORTH. WINDS 7 KT OR LESS THROUGHOUT THE PERIOD...MAINLY FROM THE
SOUTHEAST.
OUTLOOK...
SUNDAY NIGHT...VFR-MVFR WITH SHRA AND ISOLD TSRA POSSIBLE...AT
KRWF. SE WINDS 5-10 KTS.
MONDAY...VFR. NW WINDS 5-10 KTS.
TUESDAY...VFR. VARIABLE WINDS 5 KTS.
WEDNESDAY...VFR...ISOLD TSRA IN THE AFTERNOON.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
CLF/DRL
AREA FORECAST DISCUSSION
NWS GLASGOW MT
901 PM MDT SUN AUG 12 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
UPDATED THE FORECAST TO INTRODUCE SLIGHT CHANCE POPS OVER THE
NORTHERN ZONES TONIGHT. WATER VAPOR AND MODEL DATA INDICATE A
WEAK DISTURBANCE RIDING ALONG THE JET ACROSS WESTERN MONTANA. THE
DISTURBANCE IS PRESENTLY MOVING ACROSS SOUTHERN BRITISH COLUMBIA
AND ALBERTA. IT WILL MOVE ALONG THE CANADA/ NW MONTANA BORDER LATE
THIS EVENING AND TRIGGER THUNDERSTORMS DEVELOPMENT. THESE
THUNDERSTORMS WILL MOVE EASTWARD TONIGHT AHEAD OF THIS DISTURBANCE
AND ARRIVE IN NORTHEAST MONTANA BETWEEN 1 AND 2 AM TIME FRAME.
THE LATEST HRRR MODEL AS PICKED UP ON THIS AGAIN TONIGHT JUST
LIKE IT HAS OVER THE LAST FEW NIGHTS. I AM ALSO LOOKING AT THE
POSSIBILITY OF ADDING SLIGHT CHANCE POPS TO THE FORECAST FOR THE
MORNING HOURS...BUT WILL HOLD OFF ON THAT FOR NOW AND WAIT FOR THE
LATEST MODEL DATA. THE REST OF THE SHORT TERM FORECAST LOOKS GOOD.
RSMITH
PREVIOUS DISCUSSION...SYNOPTIC SET UP... A LARGE HEAT DOME
EXTENDS OVER THE SOUTHWESTERN QUADRANT OF THE UNITED STATES WITH A
RIDGE SPUR RUNNING UP THROUGH THE PACIFIC NORTHWEST AND INTO
BRITISH COLUMBIA. A LARGE TROUGH STRETCHES FROM THE NORTHWESTERN
TERRITORIES THROUGH SOUTHERN MANITOBA AND INTO THE UPPER
MISSISSIPPI VALLEY. THIS HAS PLACED NEMONT IN A NORTHWESTERN FLOW
ALOFT. AT THE SURFACE A LARGE DRY... COOL...AND SEMI-STABLE
AIR MASS HAS SET UP SHOP OVER HIGH PLAINS AND IS MODIFYING. FURTHER
WEST ANOTHER LARGE TROUGH EXISTS SOUTH OF ALASKA AND IS MOVING
ONTO THE BRITISH COLUMBIAN SHORE.
THIS EVENING... AFTERNOON HEAT HAS HELP TO WARM UP THE LOWER ATMOSPHERE
JUST ENOUGH TO RE-INDUCE CONDITIONAL INSTABILITY INTO THE NORTHWEST
FLOW ALOFT. THIS IS SHOWING UP ACROSS SOUTHERN ALBERTA ON
SATELLITE AND CANADIAN RADARS. HRRR MODEL PROJECTS THIS TO DROP
SOUTH THROUGH BLAINE COUNTY AND INTO OUR CWA AND THEN DIE OFF JUST
BEFORE MIDNIGHT. PHILLIPS... PETROLEUM... AND GARFIELD COUNTY ARE
THE MOST LIKELY TO RECEIVE ANY OF THIS BANDED PRECIPITATION. QPF
IS UNKNOWN DUE TO NARROW BANDING POTENTIAL AND STRENGTH OF THE
BANDS. BEST GUESS FOR ANY ISOLATED LOCATIONS THAT DO SEE PRECIP
WOULD BE WELL LESS THAN AN TENTH OF AN INCH.
MONDAY... CONDITIONS SHOULD BE FAIRLY SIMILAR TO TODAY INCLUDING
SEASONAL TEMPERATURES WITH PARTLY CLOUDY SKIES AND A MOSTLY DRY
AFTERNOON.
MONDAY NIGHT THROUGH TUESDAY... A PROGRESSION OF SYNOPTIC FEATURES
IS ANTICIPATED WITH THE PACIFIC NORTHWEST RIDGE MOVING OVER MONTANA
OVERNIGHT AND THEN INTO EASTERN MONTANA AND THE DAKOTAS BY
TUESDAY. THE BC TROUGH WILL EXIT THE FRONTRANGE OVERNIGHT AND THEN
TAP INTO THE ARCTIC AIRMASS BUILDING OVER NUNAVUT... CREATING AN
EXPRESS LANE DOWN THE CANADIAN PRAIRIES FOR ONE WHOPPER OF A COLD
FRONT. COMPRESSIONAL WARMING OUT AHEAD OF THE COLD FRONT WILL SHOW
UP TUESDAY MORNING AND LAST INTO THE AFTERNOON HOURS. HAVE KEPT
GRIDS ON THE WARM SIDE THROUGHOUT THESE PERIODS TO ACCOUNT FOR
THIS... WITH DAYTIME HIGHS ABOVE NORMAL FOR THIS TIME OF YEAR. THE
COLD FRONT WILL HIT IN THE LATE AFTERNOON/EVENING AND MAY HAVE A
CHANCE AT PRODUCING AS MUCH THUNDER AS REGULAR RAIN SHOWERS EARLY
ON. GAH
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
STILL ANTICIPATING COLD FRONT TO SWEEP THROUGH MONTANA EARLY
TUESDAY NIGHT. PRECIPITATION WILL BE ASSOCIATED WITH THE 700MB
TROF WHICH DROPS OUT OF CANADA INTO NORTHERN MONTANA AFTER
MIDNIGHT AND WILL TAKE UNTIL WEDNESDAY AFTERNOON TO PUSH OUT OF
SOUTHERN MONTANA. FOLLOWING THE FRONT COLD HIGH PRESSURE SETTLES
INTO THE NORTHERN PLAINS FOR TEMPERATURES ABOUT 20 DEGREES COOLER
ON WEDNESDAY AND THURSDAY COMPARED TO TUESDAY.
UPPER RIDGE REBOUNDS INTO THE PACIFIC NORTHWEST LATE IN THE WEEK
THEN SLIDES ACROSS THE NORTHERN ROCKIES OVER THE WEEKEND. THIS
WILL RESULT IN DRY BUT STEADILY WARMING TEMPERATURES THROUGH THE
END OF THE EXTENDED PERIOD. EBERT
&&
.AVIATION...
MOSTLY VFR CONDITIONS EXPECTED OVER THE NEXT 24 HOURS. WINDS WILL
CONTINUE TURNING TO THE EAST OVERNIGHT...BUT STRENGTHEN MONDAY.
ISOLATED SHOWERS AND POSSIBLY A THUNDERSTORM MAY MOVE INTO THE TAF
SITES ANYTIME THROUGH MONDAY. JAMBA
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1120 PM MDT FRI AUG 10 2012
AVIATION SECTION UPDATED
.DISCUSSION...
UPDATE FORTHCOMING. HAVE LOWERED POPS ACROSS THE AREA TO BETTER
REFLECT ONGOING CONDITIONS. RUC AND GFS MODELS CONTINUE TO INDICATE
SCATTERED SHOWERS AND THUNDERSTORMS A POSSIBILITY ACROSS THE AREA
AFTER MIDNIGHT. RADAR RETURNS INDICATE SCATTERED THUNDERSTORMS
MOVING ACROSS SOUTHWEST MONTANA AT THIS TIME. EMANUEL
&&
.AVIATION...
UPDATED 0520Z.
UPPER LEVEL TROF WITH ISOLATED SHOWERS AND THUNDERSTORMS WILL
CONTINUE TO MOVE EASTWARD THRU SOUTHWEST AND CENTRAL MT OVER NEXT 2
TO 3 HRS. EXPECT CONDITIONS TO REMAIN VFR BUT KBZN/KLWT/KHVR MAY SEE
BRIEF PERIOD OF MVFR VISIBILITY DUE TO MODERATE RAINFALL. SKIES WILL
GRADUALLY CLEAR DURING THE OVERNIGHT PERIOD WITH JUST SCATTERED
CLOUDS EXPECTED ACROSS MOST OF THE REGION ON SAT. FORECAST MODELS
STILL INDICATING SOME INSTABILITY AND MOISTURE ASSOCIATED WITH A
WEAK SECONDARY TROF SKIRTING THE US/CAN BORDER ON SAT AFTN SO HAVE
ADDED MENTION OF VCSH AT KCTB/KHVR AFTER 20Z.
WARANAUSKAS
&&
.PREV DISCUSSION...ISSUED 245 PM MDT FRI AUG 10 2012
TONIGHT THROUGH SUNDAY...SCATTERED SHOWERS AND THUNDERSTORMS WILL
CONTINUE OVER THE CENTRAL AND SOUTHERN SECTIONS OF THE REGION
THROUGH THE EVENING HOURS...THUS POPS HAVE BEEN INCREASED IN THIS
REGION. FURTHER NORTH...A PASSING THUNDERSTORM IS POSSIBLE. SOME
STORMS OVER CENTRAL MONTANA COULD PRODUCE GUSTY WINDS THIS
EVENING. EXPECT MOST OF THE THUNDERSTORM ACTIVITY TO TAPPER OFF BY
EARLY SATURDAY MORNING...THEN A MOSTLY DRY AND QUIET WEEKEND IS
EXPECTED FOR MUCH OF THE AREA. THE ONLY EXCEPTION IS A SMALL
CHANCE FOR AN ISOLATED THUNDERSTORM ON SUNDAY AFTERNOON UP IN THE
CUT BANK AREA...AS A WEAK UPPER LEVEL DISTURBANCE MOVES SOUTHWARD
INTO THE REGION. SUMMER LIKE TEMPERATURES WILL CONTINUE OVER THE
REGION...WITH MOST LOCATIONS RUNNING ABOUT 5 DEGREES ABOVE NORMAL
FOR AFTERNOON HIGH TEMPERATURES ON SATURDAY AND SUNDAY. BRUSDA
SUNDAY NIGHT THROUGH FRIDAY...THE UPPER LEVEL RIDGE OVER THE ZONES
WILL BE FLATTENED SUNDAY NIGHT AS A SHORTWAVE MOVES THROUGH THE
REGION. MID LEVEL MOISTURE WILL BE PRESENT AND SOME CONVECTION WILL
CONTINUE THROUGH THE EVENING HOURS. THE SHORTWAVE WILL MOVE EAST OF
THE ZONES AND HIGH PRESSURE WILL AGAIN DOMINATE ON MONDAY BUT THE
NEXT LOW PRESSURE TROF WILL ALREADY BE MOVING OVER THE WEST COAST.
THIS SHORTWAVE WILL MOVE ACROSS THE REGION TUESDAY AND THE
ASSOCIATED COLD FRONT WILL BRING MUCH COOLER TEMPS INTO THE AREA.
THE ECMWF IS CONSIDERABLY COOLER THAN THE GFS UNTIL MATCHING UP
AGAIN 12Z SAT. THE ECMWF TENDS TO HANDLE SIGNIFICANT CHANGES IN
TEMPERATURES BETTER THAN OTHER MODELS...SO HAVE TRENDED TEMPERATURES
COOLER THAN MOST MODELS...BUT NOT AS COOL AS THE ECMWF FOR NOW. WILL
CONTINUE TO MONITOR THE PROGRESS OF THIS SYSTEM. AN UPPER LEVEL HIGH
PRESSURE RIDGE WILL BE OVER THE WEST COAST BY WEDNESDAY AND HEIGHTS
OVER THE ZONES WILL BE REBUILDING. THIS HIGH PRESSURE RIDGE WILL
CONTINUE TO BUILD THROUGH FRIDAY AND THE AIRMASS WILL REMAIN WARM
AND DRY. TEMPS WILL BEGIN THE PERIOD WELL ABOVE NORMALS...DROP TO
BELOW NORMALS TUESDAY AND WEDNESDAY...THEN BEGIN TO TREND UPWARDS
AGAIN THROUGH FRIDAY. ZELZER/COULSTON
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 89 55 89 / 60 10 0 10
CTB 52 83 51 83 / 30 10 0 20
HLN 57 90 55 90 / 60 10 0 10
BZN 50 88 48 91 / 70 20 10 10
WEY 41 77 38 81 / 40 20 10 0
DLN 50 85 48 88 / 30 10 0 0
HVR 60 90 54 87 / 50 10 0 10
LWT 54 84 52 83 / 80 20 10 10
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING BROADWATER...
CASCADE...CENTRAL AND SOUTHERN LEWIS AND CLARK...CHOUTEAU...
EASTERN TETON...FERGUS...JEFFERSON...JUDITH BASIN...NORTHERN
ROCKY MOUNTAIN FRONT...SOUTHERN ROCKY MOUNTAIN
FRONT...MEAGHER...BEAVERHEAD AND MADISON.
RED FLAG WARNING UNTIL MIDNIGHT MDT THIS EVENING GALLATIN...
&&
$$
WEATHER.GOV/GREATFALLS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
408 PM CDT SAT AUG 11 2012
.SHORT TERM...THROUGH 00Z MONDAY. MORNING UPPER AIR ANALYSIS
INDICATES UPPER LEVEL RIDGING OVER THE SOUTHWESTERN CONUS AND
TROUGHING OVER THE EASTERN CONUS. A MID LEVEL SHORT WAVE IS ALSO
NOTED OVER EASTERN MONTANA. MID AND UPPER LEVEL JET ENERGY IS
SITUATED FROM THE NORTHWESTERN CONUS...EASTWARD INTO THE NORTHERN
PLAINS...AND THEN SOUTHEAST ACROSS THE MISSOURI AND MISSISSIPPI
VALLEYS ON INTO THE SOUTHEASTERN CONUS. THIS ~70KT UPPER LEVEL JET
AXIS REMAINS JUST TO THE EAST OF OUR CWA...MORE OVER EASTERN
NEBRASKA AND IOWA...THUS RESULTING IN FAIRLY WEAK TROPOSPHERIC
FLOW OVER SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS. WATER
VAPOR IMAGERY DOES NOT INDICATE A SUFFICIENT TROPICAL TAP OF MID
LEVEL MOISTURE ACROSS THE CENTRAL CONUS TODAY...BUT INCREASING MID
LEVEL MOISTURE IS NOTED OVER THE NORTHERN ROCKY MOUNTAIN RANGE AND
PORTIONS OF THE NORTHERN AND CENTRAL PLAINS AS THE MID LEVEL SHORT
WAVE...CURRENTLY OVER EASTERN MONTANA...APPROACHES FROM THE
NORTHWEST. THERE ALSO APPEARS TO BE A SUBTLE MID LEVEL
PERTURBATION WORKING ACROSS NEBRASKA AT THIS TIME AS WELL. AT THE
SURFACE A RIDGE OF HIGH PRESSURE IS NOTED OVER THE UPPER
MISSISSIPPI VALLEY...WITH LOW LEVEL RETURN FLOW ON THE BACK SIDE
OF THE RIDGE AXIS OVERTAKING MUCH OF THE CENTRAL PLAINS. A SURFACE
LOW IS ALSO NOTED OVER WESTERN NORTH DAKOTA...WITH AN ASSOCIATED
COLD FRONT EXTENDING SOUTH FROM THE LOW ACROSS THE NORTHERN AND
CENTRAL HIGH PLAINS.
WEAK FORCING AHEAD OF THE SUBTLE MID LEVEL PERTURBATION NOW
PUSHING ACROSS NEBRASKA IS HELPING PROMOTE ELEVATED PRECIPITATION
PRODUCTION ACROSS PORTIONS OF CENTRAL NEBRASKA...WITH RADAR DATA
FROM KUEX INDICATING ISOLATED TO SCATTERED RETURNS ACROSS NORTHERN
PORTIONS OF OUR CWA AS OF 20Z. THAT BEING SAID...PRECIPITATION
REPORTS HAVE BEEN HARD TO COME BY WITH THIS ACTIVITY WITH
PROXIMITY SOUNDINGS ACROSS OUR CWA PER RAP ANALYSIS INDICATING
PLENTY OF LOW LEVEL DRY AIR IN PLACE. STILL...QPF FIELDS FROM THE
11/12Z NAM AND OPERATIONAL GFS...AS WELL AS THE 11/12Z EC AND
11/09Z SREF-MEAN...ALL SUGGEST AT LEAST SOME PRECIPITATION WILL BE
REALIZED AT THE SURFACE ACROSS PORTIONS OF OUR WESTERN AND
NORTHERN CWA THROUGH 00Z THIS EVENING. GIVEN THE CURRENT RETURNS
FROM AREA RADARS...AS WELL AS THE ABOVE-MENTIONED MODEL
OUTPUT...WENT AHEAD AND INSERTED 20% POPS ACROSS THE NORTHERN TWO-
THIRDS OF OUR CWA THROUGH THIS EVENING. AS MENTIONED EARLIER...LOW
LEVEL MOISTURE VALUES ARE FAIRLY LOW AS OF EARLY AFTERNOON WITH
SURFACE DEW POINTS ACROSS OUR CWA GENERALLY IN THE 50S. THIS IS
HELPING KEEP INSTABILITY ON THE WEAK SIDE ACROSS SOUTH CENTRAL
NEBRASKA AND NORTH CENTRAL KANSAS. THAT BEING SAID...THE NAM DOES
INDICATE 0-1KM MLCAPE VALUES WILL INCREASE TO ~500J/KG ACROSS OUR
NORTHERN CWA LATER THIS AFTERNOON AS MID LEVEL LAPSE RATES
UNDERNEATH THE MID LEVEL PERTURBATION INCREASE. CHANCES FOR SEVERE
WEATHER THIS AFTERNOON AND EVENING APPEAR VERY LOW DUE TO THE
OVERALL LACK IN INSTABILITY...BUT THE RAP ANALYSIS PROXIMITY
SOUNDINGS ALSO INDICATE VERY DEEP INVERTED-V SOUNDINGS ACROSS MUCH
OF THE CWA WHICH WILL BE CONDUCIVE FOR BRIEF DOWN BURSTS DESPITE
THE GENERALLY WEAK CONVECTION. GIVEN ALL THIS...WILL ALSO GO AHEAD
AND INTRODUCE STRONG STORM WORDING...BRIEF WIND GUSTS TO AROUND 50
MPH...TO THE HWO FOR THIS AFTERNOON AND EVENING...AGAIN PRIMARILY
FOR LOCATIONS ACROSS OUR NORTHERN CWA.
SHOWERS WITH EMBEDDED THUNDERSTORMS SHOULD INCREASE IN AERIAL
COVERAGE ACROSS OUR CWA AS THE MAIN MID LEVEL SHORT WAVE
APPROACHES FROM EASTERN MONTANA. PLENTY OF DPVA AND MID LEVEL
THERMAL ADVECTION AHEAD OF THE MID LEVEL TROUGH AXIS SHOULD
PRESENT A DECENT PRECIPITATION SHIELD SOMEWHERE OVER THE
REGION...WITH QPF FIELDS FROM THE 11/12Z NAM...OPERATIONAL
GFS...EC...AS WELL AS THE 11/09Z SREF-MEAN...11/12Z 4KM WRF-
NMM...AND 11/16Z HRRR ALL SUGGESTING THE MOST LIKELY AREA OF
MEASURABLE PRECIPITATION IS LOCATED FROM NORTH CENTRAL NEBRASKA
INTO EASTERN NEBRASKA...WITH THESE BEST CHANCES FOR PRECIPITATION
CLIPPING OUR NORTHEASTERN CWA...ALTHOUGH ITS IMPORTANT TO REMEMBER
PRECIPITATION CHANCES ARE IN THE FORECAST FOR THE ENTIRE CWA. THE
NAM SUGGESTS OVERNIGHT DEEP LAYER MUCAPE VALUES OF AROUND 100J/KG
WILL BE REALIZED ACROSS PORTIONS OF THE AREA TONIGHT...AND WITH
THE AMOUNT OF DPVA AND MID LEVEL THERMAL ADVECTION INFILTRATING
THE AREA TONIGHT...WOULD EXPECT MORE OF A STRATIFORM RAIN EVENT
WITH EMBEDDED CONVECTIVE CLUSTERS WITHIN THE MAIN PRECIPITATION
SHIELD. WENT AHEAD WITH ONLY AN ISOLATED THUNDER MENTION IN THE
FORECAST FOR TONIGHT AS A RESULT...WITH NOTHING IN THE WAY OF
SEVERE WEATHER CURRENTLY EXPECTED. PRECIPITATION SHOULD QUICKLY
COME TO AN END SUNDAY MORNING AS THE MID LEVEL TROUGH AXIS CLEARS
THE AREA BY 12Z SUNDAY AND SUBSIDENCE QUICKLY INFILTRATES THE AREA
THROUGH THE REMAINDER OF SUNDAY.
THE SURFACE LOW...CURRENTLY OVER WESTERN NORTH DAKOTA...IS
EXPECTED TO MOVE SOUTHEAST ACROSS THE DAKOTAS AND INTO THE
MISSOURI AND MISSISSIPPI VALLEYS OVERNIGHT TONIGHT INTO TOMORROW.
THE ASSOCIATED COLD FRONT WILL ALSO MOVE SOUTHEAST AND IS EXPECTED
TO PUSH ACROSS OUR CWA DURING THE DAY SUNDAY. THAT BEING SAID
THERE ARE INDICATIONS...ESPECIALLY FROM THE NAM...THAT THE TRUE
LOW LEVEL COLD AIR ADVECTION WILL LIKELY HOLD OFF UNTIL THE
AFTERNOON AND EVENING HOURS ON SUNDAY BEFORE INFILTRATING OUR CWA.
THIS SCENARIO LOOKS A LOT LIKE THIS PAST WEDNESDAY WHERE WE HAD A
WIND SHIFT TO THE WEST/NORTHWEST AND THIS DOWN-SLOPING
WIND...WHICH ALLOWED THE LOW LEVEL AIRMASS TO DRY OUT VERY QUICKLY
BUT ALSO EFFICIENTLY HEAT UP AS THE COOLER AIR REMAINED WELL NORTH
OF THE AREA...RESULTED IN A FORECAST WHICH PRESENTED AN
OVERWHELMING COLD BIAS WITH MANY LOCATIONS COMING DANGEROUSLY
CLOSE TO CRITICAL FIRE WEATHER CONDITIONS. GIVEN ALL THIS...OPTED
TO PLAY CLOSE TO NAM/MET GUIDANCE...WHICH BOIVERIFY INDICATES
PERFORMED THE BEST OF ANY MODEL HEADING INTO LAST WEDNESDAY...FOR
SUNDAY TEMPERATURES...DEW POINTS AND WINDS. AS A RESULT...THE
CURRENT FORECAST SHOWS AFTERNOON RELATIVE HUMIDITY VALUES IN THE
23%-25% RANGE ACROSS THE SOUTHWESTERN ONE-THIRD OF OUR CWA. BREEZY
CONDITIONS WILL ALSO BE OBSERVED POST-FROPA ON SUNDAY BUT WITH THE
COOLER AIR LAGGING WELL BEHIND...ACROSS THE NORTHERN PLAINS
THROUGH MUCH OF THE DAY...THE STRONGEST LOW LEVEL PRESSURE
GRADIENT AND RESULTANT STRONGEST WINDS SHOULD ALSO REMAIN
RELEGATED TO NORTHERN PORTIONS OF THE CWA. ALTHOUGH SUSTAINED
WINDS OF ~20KTS EXIST IN THE FORECAST FOR NORTHERN PORTIONS OF THE
CWA...FARTHER SOUTH WHERE SURFACE RELATIVE HUMIDITY VALUES WILL BE
LOWER...SUSTAINED WINDS ARE ONLY EXPECTED TO CLIMB INTO THE
14-16KT RANGE. SO...AT THIS TIME CRITICAL FIRE WEATHER CONDITIONS
ARE NOT FORECAST FOR SUNDAY...BUT THIS IS SOMETHING FUTURE SHIFTS
WILL CERTAINLY WANT TO MONITOR CLOSELY. WILL GO AHEAD AND
HIGHLIGHT NEAR CRITICAL FIRE WEATHER CONDITIONS ACROSS OUR
SOUTHWEST IN THE HWO TO GET THE WORD OUT. FINALLY...BOIVERIFY
INDICATES BCCONSRAW HAS BEEN DOING VERY WELL WITH RESPECT TO SHORT
TERM OVERNIGHT TEMPERATURE FORECASTS AND AS A RESULT...FOLLOWED
CLOSELY TO BCCONSRAW FOR OVERNIGHT LOWS TONIGHT.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. OVERALL THIS WILL BE A
COOL PERIOD WITH HIGH TEMPERATURES GENERALLY RUNNING BELOW NORMAL
ON MOST DAYS. IN ADDITION...THERE WILL BE SEVERAL CHANCES OF
SHOWERS AND THUNDERSTORMS.
SUNDAY NIGHT THROUGH MONDAY. AN UPPER TROUGH WILL TRACK FROM IOWA
INTO THE GREAT LAKES WITH COOL HIGH PRESSURE SETTLING INTO THE
REGION. THIS WILL ALSO RESULT IN DRY WEATHER. MONDAY SHOULD BE A
GREAT DAY AS THE WINDS BECOME LIGHT UNDER THE SFC HIGH PRESSURE
AND HIGH TEMPERATURES WILL RANGE FROM AROUND 80 OVER SOUTHERN
NEBRASKA TO THE MID 80S OVER NORTHERN KANSAS. DECIDED TO GO A
TOUCH BELOW GUIDANCE WITH HIGH TEMPERATURES OVER NEBRASKA ZONES.
MONDAY NIGHT THROUGH TUESDAY...A WEAK SHORT WAVE WILL TRACK
THROUGH THE CENTRAL PLAINS. HOWEVER...FORECAST MODELS ARE NOT IN
VERY GOOD AGREEMENT ON THE TRACK OF THIS SYSTEM. THE 12Z ECMWF
WOULD MAKE FOR A RATHER RAINY MONDAY NIGHT INTO TUESDAY WHILE THE
GFS IS LESS EXCITED ABOUT PRECIPITATION. TYPICALLY THIS HAS BEEN
THE OTHER WAY AROUND THIS SEASON WITH THE GFS SHOWING MORE QPF.
ULTIMATELY IT DEPENDS ON THE TRACK OF THE WAVE AND WILL CONTINUE
TO CARRY SLIGHT POPS FOR NOW AND WILL WAIT FOR BETTER MODEL
AGREEMENT BEFORE RAISING OR LOWING POPS DURING THIS PERIOD. THE
TIMING OF THIS WAVE WOULD PUT THE MOST LIKELY TIMING OF POSSIBLE
PRECIPITATION AFTER MIDNIGHT MONDAY NIGHT THROUGH THE FIRST HALF
OF TUESDAY.
WEDNESDAY AND THURSDAY...A STRONGER SHORT WAVE WITH A SHARP COLD
FRONT WILL TRACK ACROSS OUR FORECAST AREA WEDNESDAY INTO WEDNESDAY
EVENING. THIS WILL RESULT IN SCATTERED THUNDERSTORMS WITH A FEW
POSSIBLY STRONG STORMS. THUNDERSTORMS WILL FOR THE MOST PART HAVE
MOVED THROUGH BY THURSDAY MORNING...WITH A CHANCE OF POST FRONTAL
RAIN SHOWERS DURING THE DAY ON THURSDAY. WEDNESDAY WILL LIKELY BE
ONE OF THE HOTTER DAYS OF THE WEEK AND POSSIBLY THE ONLY DAY
DURING THE LONG TERM PERIOD WITH ABOVE NORMAL HIGHS. HOWEVER...THE
TIMING OF THE COLD FRONT MAY IMPACT HIGH TEMPERATURES ACROSS
NORTHERN ZONES AND WILL NEED TO BE WATCHED CLOSELY. TEMPERATURES
ON THURSDAY WILL ONLY BE IN THE 70S ACROSS NEBRASKA TO AROUND 80
OVER NORTHER KANSAS. THE NEW CONSALL TEMPERATURES ARE ACTUALLY
EVEN A FEW DEGREES COOLER WITH THURSDAY HIGHS.
FRIDAY AND SATURDAY...DRY WEATHER WILL RETURN WITH HIGH PRESSURE
SETTLING IN BEHIND THE DEPARTING STORM SYSTEM. HIGH TEMPERATURES
WILL SLOWLY WARM...BUT REMAIN COOLER THAN NORMAL.
&&
.PREV DISCUSSION... /ISSUED 1226 PM CDT SAT AUG 11 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. MID LEVEL CLOUDS WILL PERSIST AT THE TERMINAL THROUGH
MUCH OF THE TAF PERIOD...BUT NOTHING BELOW 8000FT AGL CURRENTLY
EXPECTED. SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE OBSERVED
ACROSS PORTIONS OF THE REGION TONIGHT AND AS A RESULT...WILL GO
AHEAD WITH PROB30 TSRA 03Z-06Z...AND PREVAILING TSRA 06Z-09Z.
THERE MAY BE SOME ISOLATED CONVECTION NEAR THE TERMINAL THIS
AFTERNOON AND EVENING AS WELL...BUT AT THIS TIME THE PROBABILITY
OF MEASURABLE PRECIPITATION BEING REALIZED AT KGRI THIS AFTERNOON
AND EVENING IS FAR TOO LOW FOR INSERTION INTO THE TAF AT THIS
TIME. PRECIPITATION SHOULD QUICKLY DEPART TO THE EAST OF THE
TERMINAL BY 09Z SUNDAY WITH CLEARING SKIES OBSERVED SHORTLY
THEREAFTER. MINOR VISIBILITY RESTRICTIONS TO AROUND 6SM WILL BE
POSSIBLE IN PRECIPITATION 03Z-09Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...BRYANT
LONG TERM...WESELY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
125 PM CDT SAT AUG 11 2012
.UPDATE...MORNING UPPER AIR ANALYSIS INDICATES UPPER LEVEL RIDGING
OVER THE SOUTHWESTERN CONUS AND TROUGHING OVER THE EASTERN CONUS.
A MID LEVEL SHORT WAVE IS ALSO NOTED OVER EASTERN MONTANA. MID AND
UPPER LEVEL JET ENERGY IS SITUATED FROM THE NORTHWESTERN
CONUS...EASTWARD INTO THE NORTHERN PLAINS...AND THEN SOUTHEAST
ACROSS THE MISSOURI AND MISSISSIPPI VALLEYS ON INTO THE
SOUTHEASTERN CONUS. THIS ~70KT UPPER LEVEL JET AXIS REMAINS JUST
TO THE EAST OF OUR CWA...MORE OVER EASTERN NEBRASKA AND
IOWA...THUS RESULTING IN FAIRLY WEAK TROPOSPHERIC FLOW OVER SOUTH
CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS. WATER VAPOR IMAGERY
DOES NOT INDICATE A SUFFICIENT TROPICAL TAP OF MID LEVEL MOISTURE
ACROSS THE CENTRAL CONUS TODAY...BUT INCREASING MID LEVEL MOISTURE
IS NOTED OVER THE NORTHERN ROCKY MOUNTAIN RANGE AND PORTIONS OF
THE NORTHERN AND CENTRAL PLAINS AS THE MID LEVEL SHORT
WAVE...CURRENTLY OVER EASTERN MONTANA...APPROACHES FROM THE
NORTHWEST. THERE ALSO APPEARS TO BE A SUBTLE MID LEVEL
PERTURBATION WORKING ACROSS NEBRASKA AT THIS TIME AS WELL. AT THE
SURFACE A RIDGE OF HIGH PRESSURE IS NOTED OVER THE UPPER
MISSISSIPPI VALLEY...WITH LOW LEVEL RETURN FLOW ON THE BACK SIDE
OF THE RIDGE AXIS OVERTAKING MUCH OF THE CENTRAL PLAINS. A SURFACE
LOW IS ALSO NOTED OVER WESTERN NORTH DAKOTA...WITH AN ASSOCIATED
COLD FRONT EXTENDING SOUTH FROM THE LOW ACROSS THE NORTHERN AND
CENTRAL HIGH PLAINS.
WEAK FORCING AHEAD OF THE SUBTLE MID LEVEL PERTURBATION NOW
PUSHING ACROSS NEBRASKA IS HELPING PROMOTE ELEVATED PRECIPITATION
PRODUCTION ACROSS PORTIONS OF NEBRASKA...WITH RADAR DATA FROM KUEX
AND KLNX INDICATING ISOLATED TO SCATTERED RETURNS ACROSS NORTHERN
AND WESTERN NEBRASKA AS OF 18Z. THAT BEING SAID...PRECIPITATION
REPORTS HAVE BEEN HARD TO COME BY WITH THIS ACTIVITY WITH
PROXIMITY SOUNDINGS ACROSS OUR CWA PER RAP ANALYSIS INDICATING
PLENTY OF LOW LEVEL DRY AIR IN PLACE. STILL...QPF FIELDS FROM THE
11/12Z NAM AND OPERATIONAL GFS...AS WELL AS THE 11/00Z EC AND
11/09Z SREF-MEAN...ALL SUGGEST AT LEAST SOME PRECIPITATION WILL BE
REALIZED AT THE SURFACE ACROSS PORTIONS OF OUR WESTERN AND
NORTHERN CWA THROUGH 00Z THIS EVENING. THIS SOLUTION IS ALSO
SUPPORTED BY THE 11/00Z 4KM WRF-NMM. GIVEN THE CURRENT RETURNS
FROM AREA RADARS...AS WELL AS THE ABOVE-MENTIONED MODEL
OUTPUT...WENT AHEAD AND INSERTED 20% POPS ACROSS
NORTH/NORTHWESTERN PORTIONS OF OUR CWA FOR THIS AFTERNOON AND
EVENING. AS MENTIONED EARLIER...LOW LEVEL MOISTURE VALUES ARE
FAIRLY LOW AS OF MIDDAY WITH SURFACE DEW POINTS ACROSS OUR CWA
GENERALLY IN THE 50S. THIS IS HELPING KEEP INSTABILITY ON THE WEAK
SIDE ACROSS SOUTH CENTRAL NEBRASKA AND NORTH CENTRAL KANSAS. THAT
BEING SAID...THE NAM DOES INDICATE 0-1KM MLCAPE VALUES WILL
INCREASE TO ~500J/KG ACROSS OUR NORTHERN CWA LATER THIS AFTERNOON
AS MID LEVEL LAPSE RATES UNDERNEATH THE MID LEVEL PERTURBATION
INCREASE. CHANCES FOR SEVERE WEATHER THIS AFTERNOON AND EVENING
APPEAR VERY LOW DUE TO THE OVERALL LACK IN INSTABILITY...BUT THE
RAP ANALYSIS PROXIMITY SOUNDINGS ALSO INDICATE VERY DEEP
INVERTED-V SOUNDINGS ACROSS MUCH OF THE CWA WHICH WILL BE
CONDUCIVE FOR BRIEF DOWN BURSTS DESPITE THE GENERALLY WEAK
CONVECTION. GIVEN ALL THIS...WILL ALSO GO AHEAD AND INTRODUCE
STRONG STORM WORDING...BRIEF WIND GUSTS TO AROUND 50 MPH...TO THE
HWO FOR THIS AFTERNOON AND EVENING...AGAIN PRIMARILY FOR LOCATIONS
ACROSS OUR WESTERN AND NORTHERN CWA.
TEMPERATURES ARE STILL SOMEWHAT DIFFICULT TO PIN DOWN FOR THIS
AFTERNOON. MOST LOCATIONS ACROSS THE CWA AS OF MIDDAY ARE IN THE
70S TO NEAR 80...AND WITH EXPANSIVE CLOUD COVER INFILTRATING THE
AREA ITS HARD TO BELIEVE TEMPERATURES WILL RISE MUCH MORE THAN
10-13 DEGREES. THAT BEING SAID...THE CURRENT FORECAST ONLY HAS
AFTERNOON HIGHS RISING INTO THE LOW TO MID 80S ACROSS OUR
NORTHEAST...AND INTO THE LOW 90S ACROSS OUR SOUTHWEST. CERTAINLY
HARD TO ARGUE WITH THE INHERITED HIGH TEMPERATURES SO WENT AHEAD
AND LEFT THEM AS IS FOR TODAY. OVERALL THE FORECAST FOR TODAY IS
IN GREAT SHAPE AND THE ONLY CHANGES MADE TO THE FORECAST...OTHER
THAN THE ADDITION OF POPS FOR THIS AFTERNOON AND EVENING...WAS TO
TWEAK HOURLY SKY...DEW POINT AND WIND GRIDS TO BETTER REFLECT
CURRENT CONDITIONS.
&&
.PREV DISCUSSION... /ISSUED 1226 PM CDT SAT AUG 11 2012/
AVIATION...18Z KGRI TAF. VFR CONDITIONS EXPECTED THROUGH THE NEXT
24 HOURS. MID LEVEL CLOUDS WILL PERSIST AT THE TERMINAL THROUGH
MUCH OF THE TAF PERIOD...BUT NOTHING BELOW 8000FT AGL CURRENTLY
EXPECTED. SHOWERS WITH EMBEDDED THUNDERSTORMS WILL BE OBSERVED
ACROSS PORTIONS OF THE REGION TONIGHT AND AS A RESULT...WILL GO
AHEAD WITH PROB30 TSRA 03Z-06Z...AND PREVAILING TSRA 06Z-09Z.
THERE MAY BE SOME ISOLATED CONVECTION NEAR THE TERMINAL THIS
AFTERNOON AND EVENING AS WELL...BUT AT THIS TIME THE PROBABILITY
OF MEASURABLE PRECIPITATION BEING REALIZED AT KGRI THIS AFTERNOON
AND EVENING IS FAR TOO LOW FOR INSERTION INTO THE TAF AT THIS
TIME. PRECIPITATION SHOULD QUICKLY DEPART TO THE EAST OF THE
TERMINAL BY 09Z SUNDAY WITH CLEARING SKIES OBSERVED SHORTLY
THEREAFTER. MINOR VISIBILITY RESTRICTIONS TO AROUND 6SM WILL BE
POSSIBLE IN PRECIPITATION 03Z-09Z.
PREV DISCUSSION... /ISSUED 400 AM CDT SAT AUG 11 2012/
SHORT TERM...THROUGH 12Z TUESDAY...AN UPPER LEVEL DISTURBANCE
ACROSS THE NORTHERN ROCKIES THIS MORNING IS EXPECTED TO EJECT INTO
THE NORTHERN PLAIN THIS AFTERNOON AND EVENING...HELPING TO STEER A
LOW LEVEL TROUGH OF LOW PRESSURE ACROSS THE LOCAL AREA THIS
EVENING AND OVERNIGHT...WHICH MAY PROVIDE ENOUGH FORCING FOR SOME
SCATTERED SHOWERS AND THUNDERSTORMS. WHILE BEST SHOWER AND
THUNDERSTORM CHANCES APPEAR TO BE TO THE WEST OF THE LOCAL AREA
DURING THE MID/LATE AFTERNOON HOURS...EXPECT A FEW SHOWERS TO
REMAIN IN TACT AND CROSS PORTIONS OF SOUTH CENTRAL NEBRASKA AND
NORTH CENTRAL KANSAS THIS EVENING AND OVERNIGHT. WHILE JUST ABOUT
ALL THE MODELS ARE PAINING SOME SCATTERED PRECIP ACROSS THE AREA
OVER THIS TIME PERIOD...OVERALL QPF VALUES APPEAR TO BE FAIRLY
MODEST...WITH UNDER ONE HALF AN INCH OF TOTAL PRECIPITATION
EXPECTED IN THE WETTEST SPOTS. THIS IS SUPPORTED BY ONLY MARGINAL
SHEAR AND INSTABILITY FORECAST ACROSS THE LOCAL AREA
TONIGHT...WITH MAINLY UNORGANIZED SHOWERS AND THUNDERSTORMS WITH
VERY LOW SEVERE POTENTIAL EXPECTED AS A RESULT. TEMPERATURES THIS
AFTERNOON MAY BE A LITTLE TRICKY...AS WITH INCREASED CLOUD COVER
WOULD EXPECT AFTERNOON TEMPERATURES TO BE HELD DOWN A FEW DEGREES
FROM THEIR POTENTIAL...HOWEVER 850 MB TEMPS WARM AHEAD OF THE LOW
LEVEL TROUGH SLIGHTLY FROM FRIDAY READINGS...SO WHILE NUDGED DOWN
AFTERNOON TEMPS A COUPLE OF DEGREES FROM PREVIOUS FORECAST...KEPT
FORECAST HIGHS ABOVE FRIDAYS NICE READINGS.
THEREAFTER...A DRY COLD FRONT IS EXPECTED TO DROP SOUTHWARD ACROSS
THE CENTRAL PLAINS SUNDAY AFTERNOON...WHICH SHOULD HELP TO
MAINTAIN THE CURRENT STRING OF SEASONABLY COOL SUMMER TEMPERATURES
TO ROUND OUT THE SHORT TERM FORECAST PERIODS...WITH THE NEXT
APPROACHING UPPER LEVEL DISTURBANCE EXPECTED TO BRING A SLIGHT
CHANCE OF SOME SHOWERS AND THUNDERSTORMS TO THE REGION LATE MONDAY
NIGHT. WINDS WILL ALSO INCREASE OUT OF THE NORTH ON SUNDAY WITH
THE PASSING COLD FRONT...BUT RELATIVE HUMIDITIES AT THIS TIME
APPEAR TO REMAIN HIGH ENOUGH TO AVOID ANY CRITICAL FIRE WEATHER
CONDITIONS AT THIS TIME.
LONG TERM...12Z TUESDAY THROUGH FRIDAY. OVERALL LITTLE NOTABLE
CHANGE WAS MADE TO THE BIG PICTURE DURING THIS 4-DAY
PERIOD...WHICH WILL BE MARKED BY A CONTINUED WELCOME STRETCH OF
NEAR-NORMAL TO BELOW NORMAL TEMPERATURES...ALONG WITH A FEW
CHANCES FOR AT LEAST SPOTTY RAINFALL...AND MAYBE A SHOT AT MORE
WIDESPREAD RAINFALL ESPECIALLY WED NIGHT. AS DISCUSSED LAST
NIGHT...THE DOWNWARD TRENDING OF HIGH TEMPS FOR THURSDAY
CONTINUES.
STARTING OUT TUESDAY/TUESDAY NIGHT...LEFT AT LEAST 20 POPS GOING
CWA-WIDE THE ENTIRE TIME...WITH SLIGHTLY HIGHER 30 PERCENT CHANCES
FOCUSED WITHIN THE EASTERN HALF OF THE AREA. THE 00Z ECMWF/GFS
DETERMINISTIC SOLUTIONS ARE FAIRLY CONSISTENT ON THE SYNOPTIC
SCALE SCENE ALOFT...WITH WEST-NORTHWEST FLOW OVER THE AREA IN
BETWEEN THE SUBTROPICAL RIDGE AXIS WELL TO THE SOUTH OVER THE
SOUTHERN CONUS...AND A DEEPENING SHORTWAVE TROUGH PASSING FROM
SOUTHWEST CANADA TOWARD THE NORTHERN ROCKIES/NORTHERN PLAINS.
RIGHT OFF THE BAT THOUGH...THERE ARE SOME INCONSISTENCIES...AS THE
ECMWF SOLUTION DEPICTS LINGERING DAYTIME SHOWERS/STORMS ASSOCIATED
WITH A LOW AMPLITUDE DEPARTING SHORTWAVE BUT A DRY NIGHT...WHILE
THE GFS AND ITS ENSEMBLE MEAN SHOW LIMITED SUPPORT FOR DAYTIME
PRECIP BUT A BIT BETTER SIGNAL FOR TUES NIGHT. FOR NOW...THE BEST
APPROACH SEEMS TO BE LEAVING THE 20-30 PERCENT CHANCES
GOING...WITH PLENTY OF TIME STILL FOR REFINEMENT OR REMOVAL. NO
MATTER...NOT SEEING MUCH OF A SEVERE WEATHER THREAT WITH ANY
STORMS DURING THIS TIME FRAME DUE TO LIMITED
INSTABILITY...ALTHOUGH SEASONALLY TYPICAL SMALL HAIL/GUSTY WIND
NOT OUT OF THE QUESTION GIVEN AT LEAST MODEST DEEP LAYER SHEAR AT
LEAST 25-35KT. TEMP WISE...MADE ALMOST NO CHANGE TO THE HIGHS OR
LOWS...WITH MOST OF THE CWA TOPPING OUT BETWEEN 83-90 DURING THE
DAY.
WEDNESDAY/WEDNESDAY NIGHT...THIS IS BY FAR THE MOST INTERESTING 24
HOURS OF THE PERIOD...AS BOTH THE ECMWF/GFS SWING THE POSITIVELY
TILTED SHORTWAVE TROUGH AXIS FROM THE NORTHERN ROCKIES/PLAINS
TOWARD THE CENTRAL PLAINS...ALTHOUGH THE ECMWF ADVERTISES AN
OVERALL SHARPER/STRONGER WAVE WITH A STRONGER UPPER LEVEL JET
ALONG ITS LEADING EDGE. IN THE LOW LEVELS HOWEVER...BOTH MODELS
ARE IN VERY GOOD AGREEMENT BRINGING A COLD FRONT INTO AT LEAST
NORTHWEST PORTIONS OF THE CWA LATE IN THE DAY...BEFORE PUSHING IT
ALL THE WAY THROUGH THE AREA IN A DECENTLY FORCED MANNER WED
NIGHT. AHEAD OF THIS BOUNDARY...MOST OF THE DAY IS ANTICIPATED TO
BE DRY AND CAPPED WITH SOUTHERLY SURFACE WINDS RESULTING IN WHAT
SHOULD BE THE WARMEST DAY OF THE WEEK...AND MADE ESSENTIALLY NO
CHANGE TO HIGH TEMPS WITH MAINLY UPPER 80S NEB ZONES...AND LOW-MID
90S IN KS. BY LATE AFTERNOON...COULD THEN SEE A CORRIDOR OF STRONG
TO POTENTIALLY SEVERE STORMS ERUPT IN OR VERY NEAR THE CWA ALONG
THIS FRONT...WITH MORE WIDESPREAD ACTIVITY THEN DEVELOPING MAINLY
BEHIND THE FRONT WED EVENING/NIGHT AS THE CWA BECOMES ALIGNED
WITHIN THE ENTRANCE REGION OF A 300MB JET STREAK EXTENDING FROM
THE DAKOTAS INTO QUEBEC. ALTHOUGH NOT LOOKING LIKE A WIDESPREAD
SEVERE WEATHER EVENT AT THIS POINT...AT LEAST A FEW SEVERE STORMS
CERTAINLY NOT OUT OF THE QUESTION GIVEN SUCH STRONG FORCING AND
INCREASING POST-FRONTAL DEEP LAYER SHEAR. POP-WISE...KEPT ONLY
SLIGHT 20S GOING THROUGH THE DAY...AGAIN MAINLY FOR AFTERNOON
POTENTIAL...BUT INCREASED NIGHT PERIOD TO CHANCE 30S FOR
NOW...WITH FURTHER INCREASES LIKELY IF TRENDS HOLD.
THURSDAY/THURS NIGHT...THE SOUTHERN END OF THE SHORTWAVE AXIS
QUICKLY SLIDES EAST OF THE REGION...CARVING OUT A LONGWAVE TROUGH
OVER THE EASTERN HALF OF THE CONUS BY FRIDAY MORNING AS RIDGING
DOMINATES THE WESTERN STATES...LEAVING THE LOCAL AREA UNDER
SEASONABLY STRONG NORTHWEST FLOW. FOR THE DAYTIME...INTRODUCED
SOME 20-30 POPS ACROSS MAINLY KS ZONES TO ACCOUNT FOR DEPARTING
PRECIP. FOR NOW LEFT A THUNDER MENTION WITH THIS ACTIVITY...BUT
LATER SHIFTS MAY CONSIDER CONVERTING TO ONLY SHOWER WORDING AS
INSTABILITY SHOULD BE ON THE WANE BY THEN. CONFIDENCE IS THEN
RATHER HIGH IN A DRY THURS NIGHT PERIOD AS COOL HIGH PRESSURE
BUILDS IN AT THE SURFACE. TEMP-WISE...LOWERED HIGHS ANOTHER 3-4
DEGREES...NOW ADVERTISING ONLY UPPER 70S NORTH TO MID 80S
SOUTH...WHICH STILL MIGHT NOT BE COOL ENOUGH. ALONG THOSE SAME
LINES...THE CURRENTLY ADVERTISED LOWS IN THE 50S THURS NIGHT COULD
END UP BEING IN THE 40S SOME AREAS IF SKIES ARE CLEAR AND THE
SURFACE RIDGE AXIS SETS UP ACROSS OR VERY NEAR THE CWA AS
CURRENTLY DEPICTED.
FRIDAY DAYTIME...CONFIDENCE IS CURRENTLY RATHER HIGH FOR BEING 6
DAYS OUT IN A DRY AND PLEASANT END TO THE WORK-WEEK AS DRY
NORTHERLY FLOW PREVAILS ALOFT...AND THE SURFACE RIDGE AXIS SLOWLY
MIGRATES EAST ACROSS THE REGION. KEPT SEASONABLY COOL HIGHS ALMOST
UNCHANGED...WITH MOST NEB ZONES ONLY UPPER 70S...AND MORE SO LOW-
MID 80S IN KS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
125 PM UPDATE/AVIATION...BRYANT
SHORT TERM...ROSSI
LONG TERM...PFANNKUCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
732 AM EDT SAT AUG 11 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY MORNING. THIS FRONT WILL STALL OVER THE
AREA AND DISSIPATE BY MONDAY. DRIER CONDITIONS ARE EXPECTED FOR THE
EARLY PART OF THE WEEK...BEFORE ANOTHER COLD FRONT BRINGS RENEWED
THUNDERSTORM CHANCES LATE TUESDAY AND WEDNESDAY. MORE SEASONABLE
WEATHER IS EXPECTED FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...EACH RUN OF THE HRRR HAS POOR INITIALIZATION
VERSUS RADAR AND PLACES PRECIPITATION IN DIFFERENT...SEEMINGLY
RANDOM...LOCATIONS THROUGHOUT THE DAY. ASIDE FROM THE CURRENT
CONVECTIVE DEVELOPMENT IN THE WHITEVILLE VICINITY...UPSTREAM
SATELLITE AND RADAR SHOWS LITTLE NEW ACTIVITY MOVING INTO OUR
FORECAST AREA FOR THE NEXT HOUR OR TWO. WE STILL ANTICIPATE SHOWERS
AND STORMS TO FILL IN LATER THIS MORNING AND ESPECIALLY INLAND THIS
AFTERNOON GIVEN THE HIGHLY FAVORABLE UPPER LEVEL ENVIRONMENT...DEEP
ALBEIT MODEST INSTABILITY...AND RICH MOISTURE IN THE LOW LEVELS. NO
SIGNIFICANT CHANGES HAVE BEEN MADE. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
THE ONLY THING NORMAL ABOUT TODAY`S WEATHER PATTERN IS HIGH HUMIDITY
THROUGHOUT THE ATMOSPHERE: PRECIPITABLE WATER VALUES WILL HOVER
BETWEEN 2.0 AND 2.3 INCHES THROUGH THIS EVENING. QUITE UNUSUAL FOR
EARLY AUGUST IS THE OVERALL SYNOPTIC PATTERN WHICH INCLUDES A CLOSED
UPPER LOW IN THE GREAT LAKES AND A STRONG TROUGH AXIS EXTENDING DOWN
WEST OF THE APPALACHIANS. THIS TROUGH HAS BACKED OUR MID AND UPPER
FLOW ALL THE WAY AROUND TO THE SOUTH-SOUTHWEST WITH CARIBBEAN AIR
BEING PULLED NORTH INTO THE CAROLINAS. A SURFACE COLD FRONT
CURRENTLY LOCATED IN THE MOUNTAINS WILL PUSH EAST AND INTO THE
EASTERN CAROLINAS LATE TONIGHT.
WE ARE EXPECTING GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS
TODAY...WITH CHANCES RANGING FROM 50-60 PERCENT ON THE SOUTH
CAROLINA COAST TO 70 PERCENT ELSEWHERE. THE 21Z SATURDAY SREF QPF
ENSEMBLES SHOWED THE BEST POTENTIAL FOR PRECIP TODAY IS IN THE
LUMBERTON/DILLON/BENNETTSVILLE CORRIDOR WHERE I`M CONTEMPLATING AN
80 POP FOR TODAY. A FAVORABLY POSITIONED 300 MB JET STREAK EXTENDING
FROM CENTRAL NC NORTH INTO NEW ENGLAND WILL PROVIDE UPPER
DIVERGENCE...WHILE 25-30 KT WINDS AT 700 MB WILL PUSH STORMS ALONG
AT A GOOD CLIP WITH HIGH AREAL COVERAGE EXPECTED. PLENTY OF CLOUD
COVER WILL HOLD HIGHS IN THE MID TO UPPER 80S WITH TALL SKINNY CAPE
PROFILES NOTED IN MODEL FORECAST SOUNDINGS. THIS LIMITED INSTABILITY
SHOULD HELP HOLD SEVERE WEATHER PROBABILITIES DOWN...ALTHOUGH HEAVY
RAINFALL AND LOCALIZED FLOODING WILL REMAIN POSSIBLE WHERE TRAINING
STORMS OCCUR.
THE 500 MB TROUGH WILL PUSH EAST AND OVERHEAD TONIGHT...THEN
OFFSHORE BY DAYBREAK SUNDAY. THIS COULD BRING ONE MORE BAND OF
SHOWERS AND STORMS WITH IT ALTHOUGH INSTABILITY WILL BECOME MORE
LIMITED AS THE NIGHT WEARS ON. LOWS SHOULD FALL INTO THE LOWER 70S
IN MOST AREAS...WITH SOME READINGS AROUND OR JUST BELOW 70 POSSIBLE
WELL INLAND.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT WILL BE CROSSING THE CWA WHILE
DISSIPATING EARLY SUNDAY. ALTHOUGH SOME GUIDANCE HAS THE FRONT
CROSSING BEFORE THE START OF THE SHORT TERM...FAVOR THE SLOWER
SOLUTIONS WHICH SHOW FROPA BY EARLY SUNDAY AFTN DUE TO SOMEWHAT
BOUNDARY-PARALLEL MID LEVEL FLOW. FORECAST SOUNDINGS SUGGEST VERY
DRY AIR WORKING IN FROM WEST TO EAST BEHIND THE FRONT...SO ANY
PRECIP EARLY SUNDAY WILL FADE BY AFTN AND MUCH OF SUNDAY WILL BE
PRETTY NICE WITH INCREASING SUNSHINE. DRY WESTERLY FLOW PERSISTS
SUNDAY NIGHT AND MONDAY WITH PWATS FALLING TO BELOW ONE INCH. THIS
COMBINED WITH A CONVECTIVE LID NEAR 800MB WILL PREVENT ANY
CONVECTION MONDAY...AND WILL DROP INHERITED SCHC TO SILENT. TEMPS
SUNDAY WILL BE AT OR SLIGHTLY BELOW CLIMO WITH SOME WEAK COOL AIR
ADVECTION...BUT AMPLE AUGUST SUNSHINE WILL HELP RAISE TEMPS TO
AROUND 90 DURING THE AFTN...FALLING TO AROUND 70 SUNDAY NIGHT.
SIMILAR ON MONDAY...IF NOT A TOUCH WARMER...WITH LOWS ONCE AGAIN
AROUND 70.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...BROAD UPPER TROUGHING PERSISTS THROUGH
THURSDAY ACROSS THE SOUTHEAST BEFORE 500MB RIDGE BEGINS TO WORK BACK
INTO THE AREA FOR FRIDAY. UPPER TROUGH AND HENCE SLIGHTLY LOWER
1000-500MB THICKNESSES WOULD GENERALLY SUGGEST MODERATE DIURNAL
CONVECTIVE CHANCES DURING THE SUMMER...BUT OVERALL DO NOT ANTICIPATE
WIDESPREAD STORMS THROUGH MUCH OF THE PERIOD. THE EXCEPTION WILL BE
LATE TUESDAY AND WEDNESDAY AS A SHORTWAVE ROTATES DOWN THROUGH THE
BASE OF THE TROUGH AND DRIVES A COLD FRONT TOWARDS THE ILM CWA.
WINDS AHEAD OF THIS FEATURE FINALLY TURN SW ON TUESDAY...HELPING TO
FORCE THE MID LEVEL THETA-E RIDGE INTO THE MID-ATLANTIC...SERVING AS
THE FUEL FOR STORMS ALONG AND AHEAD OF THE COLD FRONT. TOO EARLY TO
GET VERY SPECIFIC IN THE DETAILS...BUT WILL CARRY CHC POP BEGINNING
LATE TUESDAY AND THROUGH WEDNESDAY FOR TSTMS. FRONT PUSHES OFFSHORE
LATE WEDNESDAY LEADING TO DRIER AND COOLER CONDITIONS
THURSDAY...BEFORE RIDGING DEVELOPS ALOFT FOR THE END OF THE WEEK.
TEMPS WILL BE RIGHT AROUND CLIMO MOST DAYS...POTENTIALLY WARMING TO
ABOVE CLIMO BY FRIDAY DUE TO INCREASING THICKNESSES AND RETURN OF SW
RETURN FLOW.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...EXPECT SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS
TO DEVELOP DURING THE PERIOD. WHILE SHOWERS AND STORMS ARE POSSIBLE
THROUGHOUT THE FORECAST PERIOD...THEY ARE MOST PROBABLE DURING THE
12 HOURS FROM APPROXIMATELY 18Z THROUGH 06Z. INTERMITTENT STORMS
WILL BE ACCOMPANIED BY MVFR OR SHORT DURATION IFR CONDITIONS. S TO
SW WINDS OF 10 TO 15 KT THIS AM WILL DIMINISH TO 5 TO 10 KT THIS
AFTERNOON.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. VFR MONDAY THROUGH
WED...OUTSIDE POSSIBLE SHOWERS AND STORMS TUESDAY NIGHT INTO WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...WINDS ARE DECREASING AS THE GRADIENT UNWINDS
ON THE WESTERN PERIPHERY OF THE BERMUDA HIGH. THE SMALL CRAFT
ADVISORY SHOULD BE ABLE TO EXPIRE ON-SCHEDULE IN JUST A COUPLE OF
HOURS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
STRONG SOUTH-SOUTHWEST WINDS THIS MORNING ARE THE RESULT OF A
PINCHED GRADIENT ALONG THE WESTERN EXTENT OF THE BERMUDA HIGH. A
SURFACE COLD FRONT HAS PUSHED INTO THE SOUTHERN APPALACHIANS...AND
THIS BOUNDARY WILL MOVE EAST AND INTO THE EASTERN CAROLINAS LATE
TONIGHT. SOUTH TO SOUTHWEST WINDS WILL CONTINUE THROUGH
TONIGHT...ALTHOUGH THE STRONGEST WIND SPEEDS ARE EXPECTED NOW
THROUGH DAYBREAK IN ASSOCIATION WITH A LOW LEVEL JET STREAM
OVERHEAD. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE FAIRLY
WIDESPREAD THIS MORNING ACROSS THE COASTAL WATERS...WITH SOME
DECREASE IN COVERAGE EXPECTED THIS AFTERNOON. AS THE MAIN UPPER
LEVEL TROUGH MOVES OUT ACROSS THE WATERS LATE TONIGHT THERE COULD BE
A SECOND WAVE OF ACTIVITY MOVING OFFSHORE...ESPECIALLY NORTH OF
MYRTLE BEACH. SEAS CURRENTLY RANGE FROM 4-5 FT AT THE CAPE FEAR AREA
BUOYS...IN-LINE WITH PREVIOUS FORECASTS. NO CHANGES ARE PLANNED AT
THIS TIME TO THE PREVIOUSLY ISSUED SMALL CRAFT ADVISORY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT WILL BE SLOWLY MOVING ACROSS THE
AREA AT THE START OF THE PERIOD...WHILE AT THE SAME TIME WEAKENING.
SW WINDS OF 10-15 KTS THROUGH SUNDAY WILL GRADUALLY VEER TO THE WEST
AND EASE BY EARLY MONDAY AS FRONT WASHES OUT OVER THE WATERS. THESE
WINDS WILL CREATE 3-4 FT SEAS SUNDAY AS THEY WORK IN TANDEM WITH AN
INCREASING 2FT/9SEC SE SWELL. ALTHOUGH THE SE SWELL WILL PERSIST ON
MONDAY...WAVE HEIGHTS WILL GRADUALLY DECAY DUE TO THE DECREASING
WINDS...FALLING TO 2-3 FT THROUGH MONDAY NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM SATURDAY...BERMUDA HIGH PRESSURE WILL CONTROL THE
SYNOPTIC FLOW TUESDAY...BEFORE A COLD FRONT WORKS THROUGH THE AREA
ON WEDNESDAY. THESE TWO FEATURES COMBINE TO CREATE INCREASING SW
WINDS BY TUESDAY NIGHT...RISING FROM AROUND 10 KTS EARLY
TUESDAY...TO AS MUCH AS 20 KTS BY EARLY WEDNESDAY...THANKS TO THE
TIGHTENING PRESSURE GRADIENT AHEAD OF THE COLD FRONT. THESE WINDS
FORCE RAPIDLY BUILDING WIND-WAVES...BECOMING 3-5 FT TUESDAY NIGHT
AND EARLY WEDNESDAY...AND A SCEC MAY BE NEEDED FOR A TIME. FRONT
WILL CROSS WEDNESDAY WHILE WEAKENING...AND WINDS WILL SLOWLY VEER TO
THE WEST BY LATE WEDNESDAY WHILE EASING TO AROUND 10 KTS. SEAS FALL
IN RESPONSE...BECOMING 2-3 FT BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR AMZ250-
252.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...RAN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
651 AM EDT SAT AUG 11 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH SUNDAY MORNING. THIS FRONT WILL STALL OVER
THE AREA AND DISSIPATE BY MONDAY. DRIER CONDITIONS EXPECTED FOR
THE EARLY PART OF THE WEEK...BEFORE ANOTHER COLD FRONT WILL BRING
RENEWED THUNDERSTORM CHANCES LATE TUESDAY AND WEDNESDAY. MORE
SEASONABLE WEATHER EXPECTED FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...EACH RUN OF THE HRRR HAS POOR INITIALIZATION
VERSUS RADAR AND PLACES PRECIPITATION IN DIFFERENT...SEEMINGLY
RANDOM...LOCATIONS THROUGHOUT THE DAY. ASIDE FROM THE CURRENT
CONVECTIVE DEVELOPMENT IN THE WHITEVILLE VICINITY...UPSTREAM
SATELLITE AND RADAR SHOWS LITTLE NEW ACTIVITY MOVING INTO OUR
FORECAST AREA FOR THE NEXT HOUR OR TWO. WE STILL ANTICIPATE SHOWERS
AND STORMS TO FILL IN LATER THIS MORNING AND ESPECIALLY INLAND THIS
AFTERNOON GIVEN THE HIGHLY FAVORABLE UPPER LEVEL ENVIRONMENT...DEEP
ALBEIT MODEST INSTABILITY...AND RICH MOISTURE IN THE LOW LEVELS. NO
SIGNIFICANT CHANGES HAVE BEEN MADE. PREVIOUS DISCUSSION FROM 300 AM
FOLLOWS...
THE ONLY THING NORMAL ABOUT TODAY`S WEATHER PATTERN IS HIGH HUMIDITY
THROUGHOUT THE ATMOSPHERE: PRECIPITABLE WATER VALUES WILL HOVER
BETWEEN 2.0 AND 2.3 INCHES THROUGH THIS EVENING. QUITE UNUSUAL FOR
EARLY AUGUST IS THE OVERALL SYNOPTIC PATTERN WHICH INCLUDES A CLOSED
UPPER LOW IN THE GREAT LAKES AND A STRONG TROUGH AXIS EXTENDING DOWN
WEST OF THE APPALACHIANS. THIS TROUGH HAS BACKED OUR MID AND UPPER
FLOW ALL THE WAY AROUND TO THE SOUTH-SOUTHWEST WITH CARIBBEAN AIR
BEING PULLED NORTH INTO THE CAROLINAS. A SURFACE COLD FRONT
CURRENTLY LOCATED IN THE MOUNTAINS WILL PUSH EAST AND INTO THE
EASTERN CAROLINAS LATE TONIGHT.
WE ARE EXPECTING GOOD COVERAGE OF SHOWERS AND THUNDERSTORMS
TODAY...WITH CHANCES RANGING FROM 50-60 PERCENT ON THE SOUTH
CAROLINA COAST TO 70 PERCENT ELSEWHERE. THE 21Z SATURDAY SREF QPF
ENSEMBLES SHOWED THE BEST POTENTIAL FOR PRECIP TODAY IS IN THE
LUMBERTON/DILLON/BENNETTSVILLE CORRIDOR WHERE I`M CONTEMPLATING AN
80 POP FOR TODAY. A FAVORABLY POSITIONED 300 MB JET STREAK EXTENDING
FROM CENTRAL NC NORTH INTO NEW ENGLAND WILL PROVIDE UPPER
DIVERGENCE...WHILE 25-30 KT WINDS AT 700 MB WILL PUSH STORMS ALONG
AT A GOOD CLIP WITH HIGH AREAL COVERAGE EXPECTED. PLENTY OF CLOUD
COVER WILL HOLD HIGHS IN THE MID TO UPPER 80S WITH TALL SKINNY CAPE
PROFILES NOTED IN MODEL FORECAST SOUNDINGS. THIS LIMITED INSTABILITY
SHOULD HELP HOLD SEVERE WEATHER PROBABILITIES DOWN...ALTHOUGH HEAVY
RAINFALL AND LOCALIZED FLOODING WILL REMAIN POSSIBLE WHERE TRAINING
STORMS OCCUR.
THE 500 MB TROUGH WILL PUSH EAST AND OVERHEAD TONIGHT...THEN
OFFSHORE BY DAYBREAK SUNDAY. THIS COULD BRING ONE MORE BAND OF
SHOWERS AND STORMS WITH IT ALTHOUGH INSTABILITY WILL BECOME MORE
LIMITED AS THE NIGHT WEARS ON. LOWS SHOULD FALL INTO THE LOWER 70S
IN MOST AREAS...WITH SOME READINGS AROUND OR JUST BELOW 70 POSSIBLE
WELL INLAND.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT WILL BE CROSSING THE CWA WHILE
DISSIPATING EARLY SUNDAY. ALTHOUGH SOME GUIDANCE HAS THE FRONT
CROSSING BEFORE THE START OF THE SHORT TERM...FAVOR THE SLOWER
SOLUTIONS WHICH SHOW FROPA BY EARLY SUNDAY AFTN DUE TO SOMEWHAT
BOUNDARY-PARALLEL MID LEVEL FLOW. FORECAST SOUNDINGS SUGGEST VERY
DRY AIR WORKING IN FROM WEST TO EAST BEHIND THE FRONT...SO ANY
PRECIP EARLY SUNDAY WILL FADE BY AFTN AND MUCH OF SUNDAY WILL BE
PRETTY NICE WITH INCREASING SUNSHINE. DRY WESTERLY FLOW PERSISTS
SUNDAY NIGHT AND MONDAY WITH PWATS FALLING TO BELOW ONE INCH. THIS
COMBINED WITH A CONVECTIVE LID NEAR 800MB WILL PREVENT ANY
CONVECTION MONDAY...AND WILL DROP INHERITED SCHC TO SILENT. TEMPS
SUNDAY WILL BE AT OR SLIGHTLY BELOW CLIMO WITH SOME WEAK COOL AIR
ADVECTION...BUT AMPLE AUGUST SUNSHINE WILL HELP RAISE TEMPS TO
AROUND 90 DURING THE AFTN...FALLING TO AROUND 70 SUNDAY NIGHT.
SIMILAR ON MONDAY...IF NOT A TOUCH WARMER...WITH LOWS ONCE AGAIN
AROUND 70.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 300 AM SATURDAY...BROAD UPPER TROUGHING PERSISTS THROUGH
THURSDAY ACROSS THE SOUTHEAST BEFORE 500MB RIDGE BEGINS TO WORK BACK
INTO THE AREA FOR FRIDAY. UPPER TROUGH AND HENCE SLIGHTLY LOWER
1000-500MB THICKNESSES WOULD GENERALLY SUGGEST MODERATE DIURNAL
CONVECTIVE CHANCES DURING THE SUMMER...BUT OVERALL DO NOT ANTICIPATE
WIDESPREAD STORMS THROUGH MUCH OF THE PERIOD. THE EXCEPTION WILL BE
LATE TUESDAY AND WEDNESDAY AS A SHORTWAVE ROTATES DOWN THROUGH THE
BASE OF THE TROUGH AND DRIVES A COLD FRONT TOWARDS THE ILM CWA.
WINDS AHEAD OF THIS FEATURE FINALLY TURN SW ON TUESDAY...HELPING TO
FORCE THE MID LEVEL THETA-E RIDGE INTO THE MID-ATLANTIC...SERVING AS
THE FUEL FOR STORMS ALONG AND AHEAD OF THE COLD FRONT. TOO EARLY TO
GET VERY SPECIFIC IN THE DETAILS...BUT WILL CARRY CHC POP BEGINNING
LATE TUESDAY AND THROUGH WEDNESDAY FOR TSTMS. FRONT PUSHES OFFSHORE
LATE WEDNESDAY LEADING TO DRIER AND COOLER CONDITIONS
THURSDAY...BEFORE RIDGING DEVELOPS ALOFT FOR THE END OF THE WEEK.
TEMPS WILL BE RIGHT AROUND CLIMO MOST DAYS...POTENTIALLY WARMING TO
ABOVE CLIMO BY FRIDAY DUE TO INCREASING THICKNESSES AND RETURN OF SW
RETURN FLOW.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...MOD CONFIDENCE RW W/TEMPO MVFR CONDS WILL OCCUR AT THE
COAST THRU 08-10Z AND AT FLO/LBT 08-12Z. ISOLD TS PSBL MAINLY AT THE
COAST. CONFIDENCE LOW ON TIMING THUS HAVE USED PROB30 GROUPS FOR
THUNDERSTORMS/IFR AFT 15Z. TIMING BASED ON BEST GFS VERTICAL
VELOCITIES.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. VFR MONDAY THROUGH WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...WINDS ARE DECREASING AS THE GRADIENT UNWINDS
ON THE WESTERN PERIPHERY OF THE BERMUDA HIGH. THE SMALL CRAFT
ADVISORY SHOULD BE ABLE TO EXPIRE ON-SCHEDULE IN JUST A COUPLE OF
HOURS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
STRONG SOUTH-SOUTHWEST WINDS THIS MORNING ARE THE RESULT OF A
PINCHED GRADIENT ALONG THE WESTERN EXTENT OF THE BERMUDA HIGH. A
SURFACE COLD FRONT HAS PUSHED INTO THE SOUTHERN APPALACHIANS...AND
THIS BOUNDARY WILL MOVE EAST AND INTO THE EASTERN CAROLINAS LATE
TONIGHT. SOUTH TO SOUTHWEST WINDS WILL CONTINUE THROUGH
TONIGHT...ALTHOUGH THE STRONGEST WIND SPEEDS ARE EXPECTED NOW
THROUGH DAYBREAK IN ASSOCIATION WITH A LOW LEVEL JET STREAM
OVERHEAD. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO BE FAIRLY
WIDESPREAD THIS MORNING ACROSS THE COASTAL WATERS...WITH SOME
DECREASE IN COVERAGE EXPECTED THIS AFTERNOON. AS THE MAIN UPPER
LEVEL TROUGH MOVES OUT ACROSS THE WATERS LATE TONIGHT THERE COULD BE
A SECOND WAVE OF ACTIVITY MOVING OFFSHORE...ESPECIALLY NORTH OF
MYRTLE BEACH. SEAS CURRENTLY RANGE FROM 4-5 FT AT THE CAPE FEAR AREA
BUOYS...IN-LINE WITH PREVIOUS FORECASTS. NO CHANGES ARE PLANNED AT
THIS TIME TO THE PREVIOUSLY ISSUED SMALL CRAFT ADVISORY.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM SATURDAY...COLD FRONT WILL BE SLOWLY MOVING ACROSS THE
AREA AT THE START OF THE PERIOD...WHILE AT THE SAME TIME WEAKENING.
SW WINDS OF 10-15 KTS THROUGH SUNDAY WILL GRADUALLY VEER TO THE WEST
AND EASE BY EARLY MONDAY AS FRONT WASHES OUT OVER THE WATERS. THESE
WINDS WILL CREATE 3-4 FT SEAS SUNDAY AS THEY WORK IN TANDEM WITH AN
INCREASING 2FT/9SEC SE SWELL. ALTHOUGH THE SE SWELL WILL PERSIST ON
MONDAY...WAVE HEIGHTS WILL GRADUALLY DECAY DUE TO THE DECREASING
WINDS...FALLING TO 2-3 FT THROUGH MONDAY NIGHT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM SATURDAY...BERMUDA HIGH PRESSURE WILL CONTROL THE
SYNOPTIC FLOW TUESDAY...BEFORE A COLD FRONT WORKS THROUGH THE AREA
ON WEDNESDAY. THESE TWO FEATURES COMBINE TO CREATE INCREASING SW
WINDS BY TUESDAY NIGHT...RISING FROM AROUND 10 KTS EARLY
TUESDAY...TO AS MUCH AS 20 KTS BY EARLY WEDNESDAY...THANKS TO THE
TIGHTENING PRESSURE GRADIENT AHEAD OF THE COLD FRONT. THESE WINDS
FORCE RAPIDLY BUILDING WIND-WAVES...BECOMING 3-5 FT TUESDAY NIGHT
AND EARLY WEDNESDAY...AND A SCEC MAY BE NEEDED FOR A TIME. FRONT
WILL CROSS WEDNESDAY WHILE WEAKENING...AND WINDS WILL SLOWLY VEER TO
THE WEST BY LATE WEDNESDAY WHILE EASING TO AROUND 10 KTS. SEAS FALL
IN RESPONSE...BECOMING 2-3 FT BY THE END OF THE PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT THIS MORNING FOR AMZ250-
252.
&&
$$
SYNOPSIS...JDW
NEAR TERM...TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...TRA
MARINE...TRA/JDW
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 AM EDT SAT AUG 11 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING A GOOD CHANCE OF SHOWERS AND
THUNDERSTORMS THROUGH THE WEEKEND. THE FRONT WILL STALL ACROSS THE
AREA SUNDAY...AND DISSIPATE MONDAY. DRIER CONDITIONS WILL OVERSPREAD
THE REGION DURING THE MID TO LATE WEEK PERIOD OF THE COMING WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 1230 AM SATURDAY...SEVERAL WAVES OF CONVECTION HAVE PUSHED
ACROSS SE NORTH CAROLINA SINCE SUNSET...AND ANOTHER WAVE APPEARS TO
BE COMING UP THE COAST AROUND GEORGETOWN CURRENTLY. WE HAVE
INCREASED POPS INTO THE 60-70 PERCENT RANGE WITH THIS NEXT
FEATURE...EXPECTING IT TO REACH MYRTLE BEACH AND WILMINGTON BEFORE
SUNRISE. ALTHOUGH NOT INITIALIZED PERFECTLY THE 00Z AND 01Z RUNS OF
THE HRRR SHOW AN EXPANSION OF INLAND CONVECTION OCCURRING IN THE
08-10Z TIME FRAME...PROBABLY LINKED TO THE APPROACH OF ANOTHER UPPER
DISTURBANCE WITHIN THE BROADLY DIVERGENT PATTERN AT 200 AND 300 MB.
WE`RE PROBABLY WITHIN A FEW DEGREES OF LOW TEMPERATURES AT MOST
LOCATIONS...OTHERWISE FEW SIGNIFICANT CHANGES ARE PLANNED.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...PRIMARY WEATHER FEATURE IMPACTING THE WEEKEND
IS A WEAK COLD FRONTAL PASSAGE ASSOCIATED WITH A TRAVERSING UPPER
AND DE- AMPLIFYING TROUGH EARLY SUNDAY. THE NET RESULT IS LOTS OF
DRY AIR ABOVE 9000 FEET BY SUNDAY AFTERNOON. AHEAD OF THIS SYSTEM
WE HAVE A GOOD SHOT OF PCPN SATURDAY...TAPERING TO ISOLATED
THROUGH SUNDAY. AT THE SURFACE THE FRONT IS SO WEAK THAT IT
APPEARS SOUTHERLY LOW-LEVEL FLOW IS SUSTAINED THROUGH
SUNDAY...WITH BRIEF VEERING TO WSW SUNDAY AFTERNOON AND
NIGHT...ACCOMPANIED BY SEVERAL DEGREE DEW POINT DROPS LATE SUNDAY.
THIS SHOULD TAKE AN EDGE OFF THE MUGGINESS LATE IN THE WEEKEND.
BECAUSE THE SURFACE FRONT IS WEAK...LITTLE COOLING IS ANTICIPATED
AND TEMPERATURES WILL ADHERE CLOSE TO CLIMATOLOGY SUNDAY...BUT A
BIT COOLER THAN NORMAL SATURDAY DUE TO CLOUDS OR RAIN-COOLED AIR.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 3 PM FRIDAY...MODEL AGREEMENT IS FAIRLY GOOD ON MONDAY SHOWING
A FAIRLY DRY WSW MID LEVEL FLOW AHEAD OF A TROUGH DEVELOPING OVER
WESTERN GREAT LAKES. AT THE SURFACE THE GRADIENT IT QUITE WEAK AND
LOW LEVEL FLOW OUT OF THE SW WILL KEEP DEEPEST MOISTURE OFFSHORE.
THIS TROUGH SWINGS INTO THE EASTERN U.S. ON TUESDAY BUT THE FIRST
HINTS AT MODEL SOLUTION DIVERGENCE STARTS TO APPEAR. LOWERED HEIGHTS
ARGUABLY COULD SUPPORT SOME FORCING FOR RAINFALL BUT LOW LEVEL
MOISTURE REMAINS QUESTIONABLE...AND THE WETTER LOOKING GFS SEEMS TO
ADVECT IT IN FROM THE WEST...WHICH LOOKS OVERDONE. FROM THERE THE
GFS AND CMC HOLD ON TO SOME EASTERN TROUGHINESS ALBEIT FURTHER TO
THE EAST. THE OLD RUN OF THE EC IS MUCH MORE PROGRESSIVE AND QUICKLY
FLATTENS OUT THE FLOW BEYOND WEDNESDAY. EITHER WAY THE FORECAST
IMPLICATIONS LOCALLY ARE QUITE SIMILAR IN THAT RAIN CHANCES WILL BE
QUITE LOW AND TEMPS NEAR CLIMO.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...MOD CONFIDENCE RW W/TEMPO MVFR CONDS WILL OCCUR AT THE
COAST THRU 08-10Z AND AT FLO/LBT 08-12Z. ISOLD TS PSBL MAINLY AT THE
COAST. CONFIDENCE LOW ON TIMING THUS HAVE USED PROB30 GROUPS FOR
THUNDERSTORMS/IFR AFT 15Z. TIMING BASED ON BEST GFS VERTICAL
VELOCITIES.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS THROUGH SUNDAY. VFR MONDAY THROUGH WED.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 AM SATURDAY...A NEARLY STATIONARY FRONT ACROSS THE
WESTERN CAROLINAS IS SQUEEZING THE WESTERN PERIPHERY OF THE BERMUDA
HIGH AND CREATING A LOW LEVEL SOUTHWESTERLY JET ALONG OVER THE
COASTAL CAROLINAS. SURFACE WIND SPEEDS HAVE BEEN MEASURED AS HIGH AS
23-27 KNOTS OUTSIDE OF CONVECTION IN THE PAST FEW HOURS...AND THESE
STRONG WINDS SHOULD CONTINUE UP THROUGH DAYBREAK. SEVERAL WAVES OF
SHOWERS AND STORMS HAVE AFFECTED THE CAPE FEAR REGION SINCE
SUNSET...AND ANOTHER WAVE OF SHOWERS ARE APPROACHING GEORGETOWN AND
WILL PROBABLY MOVE NORTHEAST ALONG THE COAST AFFECTING MYRTLE BEACH
AND PERHAPS CAPE FEAR LATE TONIGHT. WINDS AND SEAS SUPPORT FORECASTS
AND NO SIGNIFICANT CHANGES ARE PLANNED.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 3 PM FRIDAY...S-SW WINDS WILL PREVAIL THROUGH THE WEEKEND
AND FAR FROM IDEAL CONDITIONS EARLY IN THE GOING SINCE WE WILL BE
COMING OFF ADVISORY CONDITIONS SATURDAY MID-MORNING. AS A WEAK LOW
PRESSURE TROUGH APPROACHES LATE SATURDAY AND SUNDAY...WINDS WILL
EASE SATURDAY NIGHT AND SUNDAY. THUS IT APPEARS MARINE CONDITIONS
WILL IMPROVE THROUGH THE WEEKEND AFTER A ROUGH START EARLY SAT.
ACTIVE AND STRONG TSTMS ARE POSSIBLE THROUGH SATURDAY NIGHT AND
SOME MAY PRODUCE STRONG WIND GUSTS SINCE STORM MOTION WILL BE
SWIFT...SSW TO NNE AT 25-35 KNOTS. THUS MARINERS ARE ENCOURAGED TO
CONSULT RADAR TRENDS BEFORE HEADING OUT.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 3 PM FRIDAY...INITIALLY LIGHT SW FLOW ON MONDAY CAUSED BY WEST
ATLANTIC HIGH PRESSURE. THE GRADIENT WILL TIGHTEN ON TUESDAY AS A
SURFACE TROUGH DROPS INTO THE SOUTHEASTERN U.S. SEAS WILL THUS
TRANSITION TO A GENTLE WIND WAVE/SWELL MIXTURE ON MONDAY TO BECOMING
PREDOMINANTLY A SHORTER PERIOD WIND WAVE. SIMILARLY THE DOMINANT
WAVE HEIGHT WILL BUILD. THE BOUNDARY WILL APPROACH AND WEAKEN BY
WEDNESDAY VEERING AND DECREASING THE WINDS. SEAS WILL FOLLOW SUIT
WHILE RETAINING THE WIND WAVE-RELATED SHORTER PERIOD.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EDT SATURDAY FOR AMZ250-252.
&&
$$
SYNOPSIS...DCH/TRA
NEAR TERM...TRA
SHORT TERM...MJC
LONG TERM...MBB
AVIATION...MRR/TRA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1018 PM EDT SUN AUG 12 2012
.SYNOPSIS...
HIGH PRESSURE WILL BEGIN TO SLIDE EAST OF OUR AREA LATE TONIGHT AS
LOW PRESSURE MOVES EASTWARD ACROSS THE NORTHERN PLAINS. THE LOW
WILL TRACK TOWARD THE LOWER GREAT LAKES ON MONDAY NIGHT BRINGING A
COLD FRONT AND CHANCES FOR SHOWERS AND THUNDERSTORMS TO OUR AREA.
HIGH PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
SFC HIGH PRESSURE WILL SLIDE OFF TO THE EAST AS LOW PRESSURE
DEVELOPS INTO THE MID MS VLY IN RESPONSE TO DIGGING UPR SYSTEM
OVERNIGHT. WEAK ISENTROPIC LIFT AHD OF THIS SYSTEM HAS LED TO
VERY LIGHT RAIN SHOWERS/SPRINKLES. RADAR SHOWS THESE LIGHT
SHOWERS/SPRINKLES MOVING ACRS INDIANA AND WEAKENING. EXPECT
THIS TREND TO CONTINUE AS THE SHOWERS MOVE INTO A LESS FAVORABLE
ENVIRONMENT WITH DRIER AIR IN PLACE.
HAVE ALLOWED FOR AN INCREASE IN MID LEVEL CLOUD COVER. THESE
CONDITIONS WILL RESULT IN MOSTLY CLOUDY SKY CONDITIONS. MORE BREAKS
WILL BE PSBL IN THE SW AS INITIAL S/W PASSES BY LATE TONIGHT.
CONTINUING TO FOLLOW LATEST HRRR RUNS...HAVE ALLOWED FOR SPRINKLES
TO WORK ACRS ILN/S FA OVERNIGHT.
HAVE FCST LOWS RANGING FROM THE LOW TO MID 50S FAR EAST TO THE
LOW TO MID 60S WEST.
&&
.SHORT TERM /MONDAY NIGHT/...
THE LOW WILL CROSS ILLINOIS AND INDIANA DURING THE DAY MONDAY.
THIS MEANS OUR AREA WILL BE UNDER SOUTHERLY FLOW WITH PLENTY OF
CLOUD COVER DURING THE DAYTIME. THIS SCENARIO WILL YIELD
TEMPERATURES IN THE LOW TO MIDDLE 80S...SIMILAR TO WHAT IS BEING
EXPERIENCED UPSTREAM OVER EASTERN ILLINOIS TODAY.
MODELS DIFFER SOMEWHAT ON THE TRACK OF THE SURFACE LOW MONDAY
NIGHT. THE NAM/CMC REGIONAL/ECMWF TRACK THE LOW ACROSS OUR FORECAST
AREA TUESDAY MORNING....WHILE THE SREF AND GFS PIVOT THE LOW
ACROSS LAKE HURON. THE LATTER SOLUTION IS FASTER AND BASED ON
SATELLITE TRENDS THIS APPEARS TO BE THE MOST LIKELY SCENARIO. THIS
WOULD DRAG A COLD FRONT ACROSS OUR AREA TUESDAY MORNING. AHEAD OF
THIS FRONT...DYNAMIC FORCING WILL SUPPORT CONVECTIVE DEVELOPMENT
ACROSS INDIANA LATE MONDAY AFTERNOON WITH THIS CONVECTION SHIFTING
EAST ACROSS OUR AREA OVERNIGHT MONDAY NIGHT. THIS MEANS THE
CONVECTION WILL BE IN A WEAKENING MODE AS IT PUSHES ACROSS OUR
AREA. HOWEVER...WITH SUFFICIENT PRE-FRONTAL FORCING
OCCURRING...SHOWERS AND THUNDERSTORMS WILL LIKELY HOLD TOGETHER AS
THEY CROSS THE FORECAST AREA...WITH A WANING SEVERE WEATHER THREAT
DUE TO THE LOSS OF DAYTIME HEATING. HAVE KEPT SIMILAR POPS TO THE
PREVIOUS FORECAST PACKAGE...WITH CHANCE POPS ACROSS THE SOUTH AND
LIKELY ACROSS THE NORTH...WHERE BETTER FORCING WOULD BE OCCURRING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
QUITE A BIT OF VARIABILITY AMONG THE MODELS IN REGARD TO THE SPEED
AND TRACK OF THE SYSTEM EXITING THE AREA ON TUESDAY. THE 12Z NAM IS
THE SLOWEST AND FARTHEST SOUTH...WITH THE SURFACE LOW JUST TO OUR
SOUTHWEST AT 12Z TUESDAY. MEANWHILE THE 12Z GFS IS FASTER AND MUCH
FARTHER NORTH WITH THE LOW. THE 12Z CMC AND ECMWF ARE MORE IN THE
MIDDLE AND WILL TREND THE FORECAST THAT WAY...SLOWING THE END OF
PCPN A BIT THROUGH THE DAY ON TUESDAY. WILL CONTINUE WITH HIGHS ON
TUESDAY IN THE UPPER 70S TO LOWER 80S...BUT THEY MAY END UP BEING A
LITTLE TRICKY DEPENDING ON THE EXACT PLACEMENT/TIMING OF THE LOW AND
RESULTING CLOUD COVER.
SKIES WILL BECOME MOSTLY CLEAR TUESDAY NIGHT INTO WEDNESDAY AS HIGH
PRESSURE BUILDS IN FROM THE WEST. THIS WILL LEAD TO A BRIEF SHOT OF
WEAK CAA WHICH SHOULD HELP KEEP TEMPERATURES DOWN IN THE LOWER TO
POSSIBLY MID 80S ON WEDNESDAY. AS THE HIGH SLIDES OFF TO THE EAST
THROUGH THE DAY ON THURSDAY...WE WILL GET INTO RETURN FLOW...
RESULTING IN THE WARMEST DAY OF THE WEEK WITH HIGHS INTO THE MID TO
UPPER 80S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH DAYS
GENERALLY IN THE LOWER 70S.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
SFC HIGH PRESSURE WILL SLIDE OFF TO THE EAST WITH LOW PRESSURE
DEVELOPING INTO THE MID MS VLY OVERNIGHT. WEAK ISENTROPIC LIFT
WILL DEVELOP ACRS THE AREA WITH MID LEVEL CIGS DEVELOPING. RADAR
SHOWS A LIGHT SHOWERS/SPRINKLES MOVING ACRS INDIANA. AS THESE SHOWERS
MOVE INTO A LESS FAVORABLE ENVIRONMENT WITH DRIER AIR IN PLACE EXPECT
SOME WEAKENING TO TAKE PLACE. HAVE CONTD VFR CONDITIONS AS MID
LEVEL CIGS DEVELOP AND HAVE HANDLED THIS CHC WITH A MENTION OF
VCSH IN WESTERN TAF SITES. AXIS OF INSTBY DEVELOPS AHD OF APPROACHING
FRONTAL BOUNDARY LATE MONDAY AFTN. HAVE A MENTION OF VCTS
BEGINNING AT 20Z IN WESTERN TAF SITES. BETTER DYNAMICS AND INSTBY
COME INTO PLAY BY LATE EVENING WITH THE APPROACH OF THE FRONTAL
BOUNDARY. SO HAVE A MENTION OF THUNDER AT 30 HOUR KCVG TAF SITE.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE MONDAY NIGHT INTO TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...AR
SHORT TERM...LATTO
LONG TERM...JGL
AVIATION...AR
AREA FORECAST DISCUSSION
NWS TULSA OK
745 PM CDT SUN AUG 12 2012
.DISCUSSION...
TEXT PRODUCTS WERE UPDATED TO INCLUDE SVR WATCH FOR SE OK. SLOW
MOVING FRONT EXTENDS FROM SE KS DOWN TO THE WEST OF TULSA AND THEN
DOWN INTO SOUTH CENTRAL OK. SEVERE STORMS HAVE ERUPTED OVER SOUTH
CENTRAL OK DOWN WHERE THE BEST INSTABILITY LIES...AND WITH 30KTS
OF 500MB FLOW...THERE IS ENOUGH SHEAR TO FOR SUSTAINED CELLS TO
ROTATE. FAIRLY UNIDIRECTIONAL WNW FLOW ALOFT IS FAVORING SPLITTING
CELLS...AND INDEED A LEFT SPLIT IS MOVING TOWARD PUSHMATAHA COUNTY
AS I TYPE. OTHER CELLS ARE DEVELOPING TO ITS NORTH AS WELL...SO
SOME CELL MERGERS COULD OCCUR AS WELL. VERY LARGE HAIL AND
DAMAGING WINDS WILL BE THE PRIMARY THREATS. WILL CONTINUE TO
MONITOR AREAS TO THE NORTH ALONG THE FRONT...AS THE LATEST RUNS OF
THE HRRR MODEL CONTINUE TO INDICATE SCT DVLPMT THIS EVENING.
LACY
&&
.PREV DISCUSSION... /ISSUED 621 PM CDT SUN AUG 12 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A COLD FRONT IS POISED TO MOVE THROUGH KBVO AND THE TULSA
TAF SITES DURING THE NEXT HOUR OR SO. THE FRONT WILL SLOWLY
WORK THROUGH THE AREA TONIGHT MAKING IT THROUGH FSM AROUND 10Z.
SCATTERED THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE FRONT
TONIGHT. HAVE GONE WITH TEMPO THUNDER AT KMLC AND VCTS AT THE
ARKANSAS TAF SITES FOR NOW. VFR CONDITIONS ARE EXPECTED ON
MONDAY.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN AUG 12 2012/
DISCUSSION...
A SHORTWAVE CURRENTLY LOCATED OVER THE NORTHERN PLAINS WAS PUSHING
A COLD FRONT THROUGH WESTERN AND CENTRAL OKLAHOMA THIS AFTERNOON.
AHEAD OF THE FRONT...TEMPS HAVE WARMED INTO THE LOW 90S TO AROUND
100 DEGREES WITH BREEZY SOUTHERLY WINDS. THIS FRONT IS EXPECTED TO
ENTER INTO EASTERN OKLAHOMA DURING THE LATE AFTERNOON/EVENING
HOURS AND NORTHWEST ARKANSAS OVERNIGHT. CHANCES FOR SHOWERS AND
THUNDERSTORMS REMAIN PROBABLE ACROSS THE REGION AS THE FRONT
PUSHES THROUGH. TEMPS THIS AFTERNOON ARE WARMING ENOUGH TO DEVELOP
INSTABILITY OVER THE REGION WHICH WILL CREATE THE POTENTIAL FOR
SEVERE THUNDERSTORMS THROUGH THE EVENING HOURS. DAMAGING WINDS AND
LARGE HAIL STILL LOOK TO BE THE MAIN THREATS. WINDS WILL SHIFT OUT
OF THE NORTH-NORTHWEST BEHIND THE FRONTAL PASSAGE...WHICH COULD
CREATE A CONCERN FOR THE FIGHTING OF ANY WILDFIRES. THE COLD FRONT
SHOULD BE NEAR THE RED RIVER VALLEY MONDAY MORNING...WITH MOST OF
THE PRECIP HAVING PUSHED OUT OF THE AREA. WILL LEAVE A SLIGHT
CHANCE POP ACROSS FAR SOUTHEAST OKLAHOMA.
BEHIND THE FRONTAL BOUNDARY...LATEST MODEL SOLUTIONS DEVELOP A MCS
OVER EASTERN COLORADO/WESTERN KANSAS MONDAY NIGHT AND PUSH IT
EAST/SOUTHEASTWARD TUESDAY MORNING. THE LOCATION OF THE MCS
TUESDAY MORNING STILL REMAINS SOME WHAT UNCERTAIN THOUGH ANY
OUTFLOW BOUNDARY COULD PUSH THROUGH THE REGION IF THE MCS STAYS
OVER KANSAS. THUS...WILL CONTINUE CHANCE POPS TUESDAY AND COOLER
TEMP NORTH OF I-40. IF INDICATIONS ARE THAT THE SYSTEM COULD REMAIN
NORTH OF THE REGION...THEN THESE TEMPS WILL NEED TO BE BUMPED BACK
UP.
A PIECE OF ENERGY WITHIN THE NORTHWESTERLY UPPER LEVEL FLOW LOOKS
TO MOVE ACROSS THE SOUTHERN PLAINS TUESDAY AND WEDNESDAY AS WELL
WHICH WILL KEEP POPS IN THE GRIDS THROUGH WEDNESDAY. THE GREATEST
CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TO BE THURSDAY INTO
FRIDAY IN RESPONSE TO A STRONGER COLD FRONT MOVING ACROSS THE
PLAINS. TEMPS BEHIND THIS FRONT SHOULD BE ABLE TO BE BELOW NORMAL
WITH HIGHS IN THE 80S FOR MOST LOCATIONS INTO THE WEEKEND. USED THE
ECMWF FOR DETAILS IN THE EXTENDED PERIODS AS IT CONTINUES TO BE
THE MOST CONSISTENT WITH THIS SYSTEM.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 68 96 64 88 / 20 10 10 30
FSM 72 98 66 93 / 30 10 10 20
MLC 70 99 65 93 / 30 10 10 30
BVO 61 93 60 87 / 20 0 10 30
FYV 65 91 58 88 / 30 10 10 20
BYV 68 89 60 88 / 30 10 10 20
MKO 68 97 63 90 / 30 10 10 30
MIO 65 90 61 87 / 20 10 10 30
F10 68 98 65 90 / 20 10 10 30
HHW 73 100 67 97 / 40 20 10 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS NORMAN OK
637 AM CDT SAT AUG 11 2012
.DISCUSSION...
AVIATION DISCUSSION FOR THE 12Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE.
A FEW -SHRA WILL CONTINUE TO AFFECT WESTERN OKLAHOMA
THROUGH 15Z BEFORE DISSIPATING. ADDITIONAL -SHRA/-TSRA
MAY DEVELOP MAINLY AFTER 00Z...BUT DID NOT MENTION
DUE TO VERY LOW CONFIDENCE OF OCCURRENCE.
SOUTH/SOUTHEAST WINDS WILL BECOME GUSTY ACROSS WESTERN
OKLAHOMA BY 16Z.
MBS
&&
.PREV DISCUSSION... /ISSUED 422 AM CDT SAT AUG 11 2012/
DISCUSSION...
THE FIRST CONCERN IS ELEVATED TO CRITICAL FIRE WEATHER
CONDITIONS ESPECIALLY TODAY OVER NORTHWEST OKLAHOMA...THEN
HOT WEATHER AND RAIN CHANCES ARE THE NEXT CONCERNS.
THIS MORNING...A FEW HIGH BASED SHOWERS AND THUNDERSTORMS WILL
AFFECT FAR WESTERN OKLAHOMA AND BRING LIGHT AMOUNTS OF RAINFALL.
BASED ON THE LATEST HRRR OUTPUT...THIS ACTIVITY WILL DIMINISH
AFTER 9 AM. KEPT 20 PERCENT CHANCE WEST OF AN ALVA TO ALTUS LINE
TO ACCOUNT FOR THIS. OTHERWISE...DRY AND COOLER CONDITIONS WILL
PREVAIL. A FEW LOCATIONS NEAR EL RENO AND ADA HAVE DROPPED TO THE
UPPER 50S EARLY THIS MORNING.
THIS AFTERNOON WILL BE PARTLY TO MOSTLY SUNNY AND ABOUT 2 TO 5
DEGREES WARMER THAN YESTERDAY. PREFERRED THE HOTTER 00Z METMOS
HIGHS. SOUTHERLY WINDS WILL INCREASE OVER WESTERN OKLAHOMA.
TONIGHT...INCREASING CLOUDS AND WINDS WILL ALLOW FOR WARMER
CONDITIONS. KEPT 20 PERCENT CHANCE MAINLY OVER NORTHERN OKLAHOMA
AS A FEW HIGH BASED SHOWERS AND STORMS MAY DEVELOP...THOUGH
CONFIDENCE IS NOT THE GREATEST. ANY RAINFALL WILL BE LIGHT.
SUNDAY...VERY HOT TEMPERATURES AND A FEW AFTERNOON AND EVENING
SEVERE THUNDERSTORMS REMAIN THE BIG CONCERNS. TRIPLE DIGIT HEAT IS
EXPECTED ACROSS MOST...IF NOT ALL...OF THE AREA WITH HIGHS
POSSIBLY APPROACHING 110 DEGREES OVER SOUTHWEST OKLAHOMA AND
WESTERN NORTH TEXAS. WENT NEAR OR SLIGHTLY ABOVE 00Z METMOS HIGHS.
HEAT INDICES MAY APPROACH 105 DEGREES SOUTH OF AN ALTUS TO
STILLWATER LINE...SO A HEAT ADVISORY MAY BE NECESSARY.
AS FOR SEVERE THUNDERSTORM POTENTIAL SUNDAY AFTERNOON AND
EVENING...LATEST NAM12 RUNS SUGGESTED A FEW HIGH BASED
THUNDERSTORMS WILL DEVELOP NEAR A FRONT...SOMEWHERE NEAR
A VERNON TO OKLAHOMA CITY LINE 1 TO 4 PM CDT...THEN MOVE
SOUTHEAST. DUE TO MODERATE SHEAR AND INSTABILITY...A FEW
DAMAGING WIND GUSTS OVER 60 MPH WOULD BE THE MAIN
HAZARD. BELIEVE ANY SEVERE THREAT WOULD DIMINISH BY
MIDNIGHT.
MONDAY THROUGH WEDNESDAY...MAINLY HOT AND DRY CONDITIONS
ARE EXPECTED...THOUGH CONFIDENCE IS DECREASING TUESDAY
AND WEDNESDAY AS CLOUDS AND INCREASING MID LEVEL MOISTURE
MAY ALLOW FOR SOME STORMS AND COOLER TEMPERATURES. FOR
NOW...DID NOT MAKE MANY CHANGES DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...A SIGNIFICANT COOLDOWN WITH INCREASING
RAIN CHANCES MAY OCCUR WITH THE PASSAGE OF A COLD FRONT AS
LATEST MODELS WERE IN DECENT AGREEMENT.
MBS
FIRE WEATHER...
UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING
ACROSS WEST CENTRAL AND NORTHWEST OKLAHOMA DUE TO MODERATE
CONFIDENCE THAT CRITICAL FIRE WEATHER CONDITIONS WILL BE MET.
WINDS WILL BE MARGINAL. ANY RAINFALL IN THE WARNED AREA
THIS MORNING WILL BE ISOLATED AND VERY LIGHT...WHICH IS NOT
EXPECTED TO HAVE ANY SUBSTANTIAL EFFECT ON THE IGNITION OF
WILDFIRES.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL
CONTINUE THROUGH AT LEAST MIDWEEK.
THERE IS A LOW CHANCE FOR NEAR CRITICAL FIRE WEATHER
CONDITIONS NEAR A WICHITA FALLS TO OKLAHOMA CITY TO
STILLWATER LINE SUNDAY AFTERNOON. DUE TO MARGINAL WINDS
MAINLY UNDER 20 MPH AND HUMIDITY LEVELS ABOVE 20 PERCENT...
DID NOT ISSUE A FIRE WEATHER WATCH.
WEDNESDAY MAY HAVE A HIGHER CHANCE FOR CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 97 75 103 73 / 0 10 20 20
HOBART OK 99 74 103 72 / 20 10 10 10
WICHITA FALLS TX 101 76 108 76 / 0 10 20 20
GAGE OK 97 71 102 67 / 20 20 10 0
PONCA CITY OK 97 75 102 68 / 0 20 20 20
DURANT OK 96 73 102 74 / 0 10 20 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS
EVENING FOR OKZ004-005-009-010-014>016-021-022.
TX...NONE.
&&
$$
25/17/17
AREA FORECAST DISCUSSION...CORRECTED FIRE WX SECTION
NWS NORMAN OK
422 AM CDT SAT AUG 11 2012
.DISCUSSION...
THE FIRST CONCERN IS ELEVATED TO CRITICAL FIRE WEATHER
CONDITIONS ESPECIALLY TODAY OVER NORTHWEST OKLAHOMA...THEN
HOT WEATHER AND RAIN CHANCES ARE THE NEXT CONCERNS.
THIS MORNING...A FEW HIGH BASED SHOWERS AND THUNDERSTORMS WILL
AFFECT FAR WESTERN OKLAHOMA AND BRING LIGHT AMOUNTS OF RAINFALL.
BASED ON THE LATEST HRRR OUTPUT...THIS ACTIVITY WILL DIMINISH
AFTER 9 AM. KEPT 20 PERCENT CHANCE WEST OF AN ALVA TO ALTUS LINE
TO ACCOUNT FOR THIS. OTHERWISE...DRY AND COOLER CONDITIONS WILL
PREVAIL. A FEW LOCATIONS NEAR EL RENO AND ADA HAVE DROPPED TO THE
UPPER 50S EARLY THIS MORNING.
THIS AFTERNOON WILL BE PARTLY TO MOSTLY SUNNY AND ABOUT 2 TO 5
DEGREES WARMER THAN YESTERDAY. PREFERRED THE HOTTER 00Z METMOS
HIGHS. SOUTHERLY WINDS WILL INCREASE OVER WESTERN OKLAHOMA.
TONIGHT...INCREASING CLOUDS AND WINDS WILL ALLOW FOR WARMER
CONDITIONS. KEPT 20 PERCENT CHANCE MAINLY OVER NORTHERN OKLAHOMA
AS A FEW HIGH BASED SHOWERS AND STORMS MAY DEVELOP...THOUGH
CONFIDENCE IS NOT THE GREATEST. ANY RAINFALL WILL BE LIGHT.
SUNDAY...VERY HOT TEMPERATURES AND A FEW AFTERNOON AND EVENING
SEVERE THUNDERSTORMS REMAIN THE BIG CONCERNS. TRIPLE DIGIT HEAT IS
EXPECTED ACROSS MOST...IF NOT ALL...OF THE AREA WITH HIGHS
POSSIBLY APPROACHING 110 DEGREES OVER SOUTHWEST OKLAHOMA AND
WESTERN NORTH TEXAS. WENT NEAR OR SLIGHTLY ABOVE 00Z METMOS HIGHS.
HEAT INDICES MAY APPROACH 105 DEGREES SOUTH OF AN ALTUS TO
STILLWATER LINE...SO A HEAT ADVISORY MAY BE NECESSARY.
AS FOR SEVERE THUNDERSTORM POTENTIAL SUNDAY AFTERNOON AND
EVENING...LATEST NAM12 RUNS SUGGESTED A FEW HIGH BASED
THUNDERSTORMS WILL DEVELOP NEAR A FRONT...SOMEWHERE NEAR
A VERNON TO OKLAHOMA CITY LINE 1 TO 4 PM CDT...THEN MOVE
SOUTHEAST. DUE TO MODERATE SHEAR AND INSTABILITY...A FEW
DAMAGING WIND GUSTS OVER 60 MPH WOULD BE THE MAIN
HAZARD. BELIEVE ANY SEVERE THREAT WOULD DIMINISH BY
MIDNIGHT.
MONDAY THROUGH WEDNESDAY...MAINLY HOT AND DRY CONDITIONS
ARE EXPECTED...THOUGH CONFIDENCE IS DECREASING TUESDAY
AND WEDNESDAY AS CLOUDS AND INCREASING MID LEVEL MOISTURE
MAY ALLOW FOR SOME STORMS AND COOLER TEMPERATURES. FOR
NOW...DID NOT MAKE MANY CHANGES DURING THIS TIME FRAME.
THURSDAY AND FRIDAY...A SIGNIFICANT COOLDOWN WITH INCREASING
RAIN CHANCES MAY OCCUR WITH THE PASSAGE OF A COLD FRONT AS
LATEST MODELS WERE IN DECENT AGREEMENT.
MBS
&&
.FIRE WEATHER...
UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING
ACROSS WEST CENTRAL AND NORTHWEST OKLAHOMA DUE TO MODERATE
CONFIDENCE THAT CRITICAL FIRE WEATHER CONDITIONS WILL BE MET.
WINDS WILL BE MARGINAL. ANY RAINFALL IN THE WARNED AREA
THIS MORNING WILL BE ISOLATED AND VERY LIGHT...WHICH IS NOT
EXPECTED TO HAVE ANY SUBSTANTIAL EFFECT ON THE IGNITION OF
WILDFIRES.
ELEVATED TO NEAR CRITICAL FIRE WEATHER CONDITIONS WILL
CONTINUE THROUGH AT LEAST MIDWEEK.
THERE IS A LOW CHANCE FOR NEAR CRITICAL FIRE WEATHER
CONDITIONS NEAR A WICHITA FALLS TO OKLAHOMA CITY TO
STILLWATER LINE SUNDAY AFTERNOON. DUE TO MARGINAL WINDS
MAINLY UNDER 20 MPH AND HUMIDITY LEVELS ABOVE 20 PERCENT...
DID NOT ISSUE A FIRE WEATHER WATCH.
WEDNESDAY MAY HAVE A HIGHER CHANCE FOR CRITICAL FIRE WEATHER
CONDITIONS ACROSS THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 97 75 103 73 / 0 10 20 20
HOBART OK 99 74 103 72 / 20 10 10 10
WICHITA FALLS TX 101 76 108 76 / 0 10 20 20
GAGE OK 97 71 102 67 / 20 20 10 0
PONCA CITY OK 97 75 102 68 / 0 20 20 20
DURANT OK 96 73 102 74 / 0 10 20 30
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 10 PM CDT THIS
EVENING FOR OKZ004-005-009-010-014>016-021-022.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
157 AM EDT SAT AUG 11 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON AND SHOULD
GET HUNG UP ACROSS THE MOUNTAINS TONIGHT. THE FRONT IS EXPECTED TO
PUSH THROUGH LATE SATURDAY AND THEN SOUTH OF THE AREA ON SUNDAY.
HIGH PRESSURE WILL MOVE IN FOR THE EARLY PART OF NEXT WEEK.
MEANWHILE ANOTHER FRONT WILL APPROACH THE AREA BY MID WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
130 AM UPDATE...NO MAJOR CHANGES NEEDED FOR THE FCST. ADJUSTED TEMPS
DOWN A FEW DEGREES WITH THE RAIN COOLED STORM AREAS...GENERALLY THE
NRN UPSTATE. POPS AND SKY LOOK GOOD.
AS OF 1030 PM...CONVECTIVE COVERAGE IS BEGINNING TO INCREASE OVER NE
GA AND THE WRN UPSTATE...CONSISTENT WITH THE HRRR OUTPUT. OVERALL IT
APPEARS THAT SHRA/TSTMS WILL CONTINUE FOR SEVERAL MORE HOURS OVER
THE REGION...THOUGH THE CHANCES OF SEVERE WEATHER OR FLASH FLOODING
APPEAR TO BE DECREASING WITH THE LOSS OF HEATING.
AS OF 530 PM...A STRONG STORM HAS MOVED INTO RABUN COUNTY...AND A
LINE OF CONVECTION IS ORGANIZING OVER THE GREAT VALLEY OF TN.
HOWEVER...NOT MUCH IS HAPPENING OVER THE ERN FOOTHILLS AND PIEDMONT
ZONES ATTM AND I/VE CUT BACK POPS IN THOSE LOCATIONS FOR THE NEXT
COUPLE HOURS. THERE CONTINUES TO BE GOOD MODEL AGREEMENT THAT
CONVECTION WILL BECOME MORE WIDESPREAD THROUGH BOTH AN MCS MOVING
INTO THE NC MTNS AND CONVECTION DEVELOPING IN STRENGTHENING LLVL
CONVERGENCE ACROSS THE FOOTHILLS LATER THIS EVENING. AND THIS IS
REFLECTED WELL IN THE GRIDS.
AS OF MID AFTERNOON...VISIBLE SATELLITE IMAGERY SHOWS LOW CONVECTIVE
CLOUDS SCATTERING SUFFICIENTLY E OF THE BLUE RIDGE TO ALLOW HEATING
THAT HAS RAISED SFC-BASED CAPE INTO THE 1500-2000 J/KG RANGE ON THE
LAPS ANALYSIS. SHOWER ACTIVITY HAS DEVELOPED OVER THE CLT METRO AREA
AND ALONG THE BLUE RIDGE...WITH MORE ACTIVITY CLOSER TO THE FRONT
OVER THE CUMBERLAND PLATEAU. EXPECT SHOWERS AND STORMS TO CONTINUE
DEVELOPING AND BECOMING MORE NUMEROUS...MAINLY OVER THE MTNS AND
FOOTHILLS...THROUGH THE LATE AFTERNOON. SEVERE WEATHER REMAINS A
CONCERN WITH SOME DRY AIR ABOVE 500 MB...ALTHO IN GENERAL THE
SOUNDINGS DO NOT LOOK AS FAVORABLE AS YESTERDAY.
OVER THE NEXT 24 HOURS OR SO...THE MODELS ARE IN GOOD AGREEMENT WITH
THE EVOLUTION OF WEATHER FEATURES...AND IN PARTICULAR SHOW THE AXIS
OF THE UPPER TROF AND THE UPPER JET REMAINING TO OUR WEST. THIS WILL
ACT TO KEEP THE SURFACE FRONT HUNG UP PROBABLY OVER THE MTNS THROUGH
SATURDAY AFTERNOON. THE TREND...THEREFORE...IS TO HOLD ON TO MORE OF
A CHANCE OF SHOWER/TSTM ACTIVITY OVER A LARGER PART OF THE FCST AREA
THROUGH 00Z SUNDAY.
THE THREAT OF SEVERE STORMS WILL SLOWLY INCREASE AS BUOYANCY
AND DCAPE SLOWLY BECOME MORE FAVORABLE...WITH JUST ENOUGH SHEAR TO
PERHAPS ORGANIZE STORMS EARLY THIS EVENING. THE 4KM WRF DEVELOPS A
LINE OF STORMS OFF THE BLUE RIDGE AROUND 23Z WHILE THE HRRR BRINGS
THE LINE OF STORMS ACROSS TN AND INTO THE NC MTNS AROUND THAT TIME.
ABUNDANT LOW LEVEL MOISTURE AND ENUF UPPER FORCING WILL EXIST TO
WARRANT A LIKELY POP INTO THE EVENING HOURS. WILL KEEP POP IN THE
CHANCE RANGE OVERNIGHT AS ADDITIONAL STORMS COULD REDEVELOP AT ANY
TIME WITH THE SITUATION REMAINING UNCHANGED. TEMPS WILL REMAIN MILD.
ON SATURDAY...EXPECT THE FRONT TO BE HUNG UP OVER THE MTNS AT
SUNRISE. UNLESS EXTENSIVE CONVECTIVE DEBRIS PREVENTS IT...CONVECTION
SHOULD RE-FIRE EARLY IN THE DAY CLOSE TO THE FRONT AS IT DID TO OUR
WEST THIS PAST MORNING. UPPER DIVERGENCE...DPVA...AND PLENTY OF
MOISTURE SUGGEST ANOTHER POP IN THE LIKELY RANGE BY AFTERNOON OVER
THE PIEDMONT...AND A CHANCE UP TO THE BLUE RIDGE. A GUIDANCE BLEND
WAS USED FOR HIGH TEMPS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AT 200 PM EDT FRIDAY...12Z GFS AND NAM STILL SOMEWHAT AT ODDS AS TO
HOW FAST THE FRONTAL BAND OF DEEP LAYER MOISTURE AND PRECIP WILL
EXIT THE FORECAST AREA OVER THE EAST. THE NAM STIL IS FASTER AND HAS
THE DEEP LAYER FRONTAL MOISTURE EAST OF THE AREA BY 00Z SUN...WHILE
THE GFS IS CONSIDERABLY SLOWER AND WETTER. THE SREF APPEARS TO
CONTINUE TO BE A GOOD COMPROMISE FOR THE SOLUTION. THE SREF KEEPS
PRECIP CHANCES OVER THE EASTERN MOST PART OF THE FORECAST AREA EARLY
ON SAT NIGHT...AND THEN MOVES THE MOISTURE/PRECIP EAST BY MIDNIGHT.
WILL ALSO SCATTER AND CLEAR THE CLOUDS FROM NW TO SE SAT NIGHT. HIGH
PRESSURE BUILDS OVER THE AREA ON SUN WHICH SHOULD PRODUCE A VERY
NICE DAY WITH DEWPOINTS MIXING OUT INTO THE 50S OVER THE MOUNTAINS
AND LOW 60S ELSEWHERE. THE HIGH SHIFTS EAST OF THE AREA ON
MONDAY...BUT ITS LINGERING INFLUENCE SHOULD ALLOW FOR ANOTHER DRY
DAY ON MONDAY. TEMPS ARE EXPECTED TO BE SLIGHTLY BELOW CLIMO ON SUN
AND NEAR CLIMO ON MON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AT 130 PM EDT FRIDAY...A SOMEWHAT PROGRESSIVE PATTERN APPEARS TO BE
IN STORE DURING THE MEDIUM RANGE. THE UPPER AIR PATTERN WILL
GENERALLY FEATURE A MEAN TROUGH OVER THE EASTERN U.S. WITH
INDICATIONS FROM THE LATEST 12Z GFS OF BUILDING HEIGHTS TOWARD THE END
OF NEXT WEEK OVER THE EAST. LATEST HPC/GFS GUIDANCE SUGGESTS A WEAK
COLD FRONT WILL CROSS THE REGION ON TUE ALONG WITH SCATTERED
CONVECTION. THE GFS DRIVES THE FRONT SE OF THE AREA BY WED WITH HIGH
PRESSURE BUILDING IN THROUGH THU. THUS ONLY CLIMO TYPE POPS FOR
AFTERNOON CONVECTION IN THE MOUNTAINS WED AND THU. ANOTHER FRONT
APPROACHES THE AREA ON FRI AND PER HPC WILL FORECAST CHANCE TYPE
POPS. TEMPS SHOULD BE NEAR CLIMO THROUGH THE PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...KEEPING AN EYE ON THE CONVECTION UPSTREAM OF THE TERMINAL.
COULD NEED AN AWW FOR CTG LTG...BUT NOT EXPECTING SIGFNT WIND SHIFTS
OR CIG/VSBY ISSUES WITH THAT STORM. THE OVERALL PREFRONTAL ZONE IS
FAIRLY WEAK...BUT IT WILL SHIFT EAST THROUGH THE MORNING...LIKELY
CREATING A LOWERING OF CIGS TO IFR BY DAYBREAK. BRING MVFR BY
14Z...SIMILAR TO YDAY/S MORNING AIRMASS TRANSITION. THUNDER CLOSE BY
AGAIN THIS AFTERNOON...MOVING EAST OF THE TERMINAL BY 00Z PER THE
WRF ARW.
ELSEWHERE...SHOWERS AND THUNDER TO AFFECT THE SC TERMINALS OVER THE
NEXT FEW HRS. HAVE CIGS LOWERING AT ALL SITES TO MVFR/IFR AFT
09Z...SOME OF WHICH HAVE ALREADY FALLEN DUE TO RECENT PRECIP. A
LITTLE MORE DRYING AT KAVL AND KHKY COULD ALLOW FOR IFR VSBY BY
DAYBREAK. SHOWERS AND THUNDER WILL BE ISOL THIS AFTERNOON AND THE
MAIN LINE SHOULD BE EAST OF ALL SITES...HOWEVER CANNOT RULE OUT
UPPER TROF INDUCING CONVECTION IN BETTER INSOLATION AREA POST
FROPA...SO KEPT PROB30 TS AT ALL SITES EXCEPT KAVL.
OUTLOOK...A COLD FRONT WILL SLOWLY CROSS THE AREA LATE SATURDAY...
WITH DRIER HIGH PRES BUILDING IN FROM THE W THE LATTER HALF OF THE
WEEKEND. WEAK HIGH PRESSURE WILL LINGER THROUGH EARLY NEXT WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...MCAVOY/SBK
SHORT TERM...LG
LONG TERM...LG
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1227 PM CDT SAT AUG 11 2012
.UPDATE...
JUST A QUICK UPDATE TO EXPAND COVERAGE OF LIGHT RAIN SHOWERS. MOST
AREAS HAVE ONLY RECEIVED A FEW HUNDREDTHS THUS FAR...WITH A DRY
LAYER BELOW 10KFT. SOME DIFFERENCES IN MODEL TIMING HAVE ARISEN
WITH THIS MORNINGS SUITE OF GUIDANCE...THE HRRR PUSHING THE
SYSTEM THROUGH QUICKLY...WHILE THE NAM/SREF/GFS A MUCH SLOWER
PROGRESSION. AT THIS POINT...WILL NOT TINKER WITH THE
TIMING/COVERAGE FOR THIS EVENING/OVERNIGHT GIVEN UNCERTAINTY. DO
EXPECT THAT AS WE CONTINUE TO MOISTEN UP THE DRY LAYER...AND THE
ASSOCIATED WAVE STRENGTHENS OVER WESTERN SOUTH
DAKOTA...PRECIPITATION WILL INTENSITY AND INCREASE IN COVERAGE.
ALSO DROPPED HIGH TEMPERATURES A FEW DEGREES WITH WIDESPREAD CLOUD
COVER/RAIN.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
CHILLY AND GENERALLY WET CONDITIONS ARE EXPECTED FOR THE WEEKEND
ACROSS THE NORTHERN PLAINS.
THE AREA OF HIGH PRESSURE THAT BROUGHT SEASONALLY COOL CONDITIONS
TO THE EASTERN DAKOTAS FOR THE PAST FEW DAYS WILL GRADUALLY BE
REPLACED BY A LOW PRESSURE SYSTEM. THIS LOW PRESSURE SYSTEM WILL
HAVE SOME DRY AIR TO OVER COME BELOW 700 MB...WITH MODELS NOW PCPN
REACHING THE I-29 CORRIDOR CLOSER TO 0Z SUNDAY. THIS SLOW
PROGRESSION SEEMS PRETTY LIKELY GIVEN SHOWERS HAVE BEEN ONGOING
ALL NIGHT IN WESTERN SD...WITH LITTLE ADVANCEMENT TOWARD THIS CWA.
THE BEST TIMING FOR PCPN FOR THE CWA APPEARS TO BE TONIGHT THROUGH
SUNDAY. MODELS ARE SUGGESTING THE SURFACE AND UPPER LEVEL LOW
WILL BE NEARLY VERTICALLY STACKED OVER SOUTHERN SD WITH DECENT
WAA FLOW WRAPPING NORTHWARD INTO THIS CWA. WITH 850 MB TEMPS ONLY
IN THE LOWER TEENS...ALONG WITH CLOUDY SKIES...HIGH TEMPERATURES
ON SUNDAY WILL LIKELY STRUGGLE TO REACH THE MID 60S IN THE EASTERN
HALF OF THE CWA.
THE LOW PRESSURE SHOULD FINALLY EXIT THE REGION BY MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED TO START THE WORK WEEK.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
MAIN FORECAST CHALLENGE DURING THE EXTENDED WILL BE THE SFC COLD
FRONT THAT WILL MOVE THROUGH THE DAKOTAS MID WEEK. ENHANCED BY
SHORTWAVE ACTIVITY AND WITH GOOD SHEAR...SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY. H85 TEMPS IN THE
LOWER 20S WILL PLUMMET INTO THE UPPER SINGLE DIGITS BEHIND THE
FRONT. TEMPERATURES NEAR NORMAL AT THE START OF THE PERIOD WILL
FALL TO 5 TO 10 DEGREES BELOW AVERAGE THURSDAY THROUGH SATURDAY.
&&
.AVIATION...
18Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A SYSTEM WILL SLOWLY MOVE ACROSS THE REGION THROUGH THE
AFTERNOON...OVERNIGHT...AND INTO MINNESOTA SUNDAY. MAINLY
ANTICIPATE VFR CONDITIONS ALONG WITH SOUTH/SOUTHEAST WINDS OVER
THE NEXT SEVERAL HOURS. OVERNIGHT AND INTO SUNDAY AM...COULD
EXPERIENCE INTERMITTENT MVFR CIGS/VISBY ALTHOUGH HAVE HIGH
UNCERTAINTY OVER WHERE/WHEN. BEST CHANCE FOR MVFR CONDITIONS
DEPEND MAINLY ON TIMING OF MAIN RAIN BAND AND WRAP AROUND CLOUD
COVER...WITH LESS LIKELIHOOD ASSOCIATED WITH THE SURROUNDING
SHOWER ACTIVITY. WINDS ON THE BACK SIDE OF THE SYSTEM WILL PICK UP
AROUND 15 TO 25MPH OUT OF THE NORTHWEST.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...SD
LONG TERM...WISE
AVIATION...CONNELLY
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
1015 AM CDT SAT AUG 11 2012
.UPDATE...
JUST A QUICK UPDATE TO EXPAND COVERAGE OF LIGHT RAIN SHOWERS. MOST
AREAS HAVE ONLY RECEIVED A FEW HUNDREDTHS THUS FAR...WITH A DRY
LAYER BELOW 10KFT. SOME DIFFERENCES IN MODEL TIMING HAVE ARISEN
WITH THIS MORNINGS SUITE OF GUIDANCE...THE HRRR PUSHING THE
SYSTEM THROUGH QUICKLY...WHILE THE NAM/SREF/GFS A MUCH SLOWER
PROGRESSION. AT THIS POINT...WILL NOT TINKER WITH THE
TIMING/COVERAGE FOR THIS EVENING/OVERNIGHT GIVEN UNCERTAINTY. DO
EXPECT THAT AS WE CONTINUE TO MOISTEN UP THE DRY LAYER...AND THE
ASSOCIATED WAVE STRENGTHENS OVER WESTERN SOUTH
DAKOTA...PRECIPITATION WILL INTENSITY AND INCREASE IN COVERAGE.
ALSO DROPPED HIGH TEMPERATURES A FEW DEGREES WITH WIDESPREAD CLOUD
COVER/RAIN.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH MONDAY
CHILLY AND GENERALLY WET CONDITIONS ARE EXPECTED FOR THE WEEKEND
ACROSS THE NORTHERN PLAINS.
THE AREA OF HIGH PRESSURE THAT BROUGHT SEASONALLY COOL CONDITIONS
TO THE EASTERN DAKOTAS FOR THE PAST FEW DAYS WILL GRADUALLY BE
REPLACED BY A LOW PRESSURE SYSTEM. THIS LOW PRESSURE SYSTEM WILL
HAVE SOME DRY AIR TO OVER COME BELOW 700 MB...WITH MODELS NOW PCPN
REACHING THE I-29 CORRIDOR CLOSER TO 0Z SUNDAY. THIS SLOW
PROGRESSION SEEMS PRETTY LIKELY GIVEN SHOWERS HAVE BEEN ONGOING
ALL NIGHT IN WESTERN SD...WITH LITTLE ADVANCEMENT TOWARD THIS CWA.
THE BEST TIMING FOR PCPN FOR THE CWA APPEARS TO BE TONIGHT THROUGH
SUNDAY. MODELS ARE SUGGESTING THE SURFACE AND UPPER LEVEL LOW
WILL BE NEARLY VERTICALLY STACKED OVER SOUTHERN SD WITH DECENT
WAA FLOW WRAPPING NORTHWARD INTO THIS CWA. WITH 850 MB TEMPS ONLY
IN THE LOWER TEENS...ALONG WITH CLOUDY SKIES...HIGH TEMPERATURES
ON SUNDAY WILL LIKELY STRUGGLE TO REACH THE MID 60S IN THE EASTERN
HALF OF THE CWA.
THE LOW PRESSURE SHOULD FINALLY EXIT THE REGION BY MONDAY
MORNING...WITH DRY CONDITIONS EXPECTED TO START THE WORK WEEK.
.LONG TERM...MONDAY NIGHT THROUGH SATURDAY
MAIN FORECAST CHALLENGE DURING THE EXTENDED WILL BE THE SFC COLD
FRONT THAT WILL MOVE THROUGH THE DAKOTAS MID WEEK. ENHANCED BY
SHORTWAVE ACTIVITY AND WITH GOOD SHEAR...SHOWERS AND THUNDERSTORMS
WILL BE POSSIBLE TUESDAY NIGHT THROUGH WEDNESDAY. H85 TEMPS IN THE
LOWER 20S WILL PLUMMET INTO THE UPPER SINGLE DIGITS BEHIND THE
FRONT. TEMPERATURES NEAR NORMAL AT THE START OF THE PERIOD WILL
FALL TO 5 TO 10 DEGREES BELOW AVERAGE THURSDAY THROUGH SATURDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. HOWEVER A SYSTEM
WILL APPROACH FROM THE WEST THROUGH TODAY. SHOWERS WILL BE
POSSIBLE FIRST AROUND KPIR/KMBG TOWARD MORNING...THOSE SHOWERS
SHOULD PUSH EAST TO KABR/KATY BY THIS AFTERNOON/EVENING AND LINGER
NEAR KATY THROUGH SUNDAY MORNING.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...CONNELLY
SHORT TERM...SD
LONG TERM...WISE
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
923 PM CDT SUN AUG 12 2012
.UPDATE...
EXTENDED WATCH SOUTH INTO MILLS COUNTY AND CANCELED FOR AREAS
NORTH OF CONVECTION INCLUDING METROPLEX. 84
&&
.AVIATION...
THUNDERSTORM THREAT WILL CONTINUE THROUGH THIS EVENING. OUTFLOW
WINDS WILL BE QUITE VARIABLE...AND LOCALLY STRONG MICROBURST
POTENTIAL WILL CONTINUE THROUGH AT LEAST 9 PM. OVERNIGHT...WINDS
WILL LIKELY RECOVER AND RETURN TO THE SOUTHWEST...AND AS WEAK COLD
FRONT APPROACHES NEAR SUNRISE (METROPLEX) WINDS WILL VEER WEST AND
THEN NORTH. 84
&&
.PREV UPDATE...
.UPDATE...
HAVE CANCELLED THE SEVERE THUNDERSTORM WARNING FOR AREAS ALONG AND
NORTHWEST OF A LINE FROM BRECKENRIDGE TO GAINESVILLE. POTENTIAL
FOR SEVERE WEATHER CONTINUES TO THE SOUTHEAST AND THE WATCH HAS
BEEN EXTENDED AS FAR SOUTH AS A LINE FROM COMANCHE TO HAMILTON TO
CORSICANA TO SULPHUR SPRINGS. NUMEROUS REPORTS OF WIND DAMAGE HAVE
BEEN RECEIVED. THE WIND THREAT WILL DECREASE SLOWLY AS THE EVENING
PROGRESSES AND SURFACE TEMPERATURES COOL. 84
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN AUG 12 2012/
ALTHOUGH THE PRIMARY MODEL GUIDANCE REMAINS IN DISAGREEMENT
REGARDING THE CONVECTIVE POTENTIAL THIS EVENING...SHORT-TERM
MESOSCALE TRENDS ARE SUGGESTING THAT THE WETTER NAM...HI-RES WRF
AND HRRR MODELS ARE ON THE RIGHT TRACK. THE COLD FRONT IS MAKING
STEADY PROGRESS TO THE SOUTH AND AT 3 PM HAS PASSED THROUGH
WICHITA FALLS. HOWEVER OBS AND RADAR INDICATE A REGION OF LOW
LEVEL CONFLUENCE FROM ABILENE TO GRAHAM TO BOWIE. THIS AREA WILL
BE THE FAVORABLE REGION FOR INITIATION...AND CONVECTION LOOKS LIKE
IT WILL INITIATE WELL AHEAD OF THE FRONT. LOCAL OBJECTIVE ANALYSIS
INDICATES AN AXIS OF 1000-2500 J/KG OF CAPE ALONG AND EAST OF A
LINE FROM GAINESVILLE TO MINERAL WELLS TO LAMPASAS...WHILE DEEP
LAYER SHEAR IS NOW RUNNING NEAR 35KT ACROSS MUCH OF THE AREA.
UNLIKE PREVIOUS SUMMERTIME CONVECTIVE EVENTS...IT HAS BEEN A
COUPLE MONTHS SINCE WE HAVE HAD THIS MUCH 0-6KM WIND SHEAR
AVAILABLE. GIVEN THE AVAILABLE INSTABILITY AND SHEAR...BRIEF
SUPERCELLS WILL BE POSSIBLE...BUT THE MOST LIKELY CONVECTIVE MODE
WILL BE LINE SEGMENTS. SURFACE TEMPERATURES ARE 105+ ACROSS THE NW
ZONES AHEAD OF THE FRONT...WHILE DEWPOINTS ARE IN THE MID 50S.
THIS WILL CREATE AN EXTREMELY FAVORABLE ENVIRONMENT FOR
DOWNBURSTS. DAMAGING WINDS WILL BE THE PRIMARY THREAT THIS
EVENING...AND BECAUSE DEEP LAYER SHEAR IS AVAILABLE IT WILL ALSO
ENHANCE THE POTENTIAL FOR LINE SEGMENTS PRODUCING ORGANIZED COLD
POOLS. STRONG OUTFLOW WINDS MAY IMPACT A MUCH WIDER AREA THAN
ACTUAL RAINFALL. WILL ALSO INCLUDE A MENTION OF HAIL IN
HWO..ALTHOUGH HOT TEMPS MAY LIMIT HAIL SIZE. THE SCATTERED
CONVECTION IS EXPECTED TO TRACK NORTHWEST TO SOUTHEAST ACROSS THE
CWA THIS EVENING...AND THE HIGHEST POPS WILL BE PLACED IN A BAND
ACROSS THE CENTRAL CWA.
THE TRUE COLD FRONT WILL LIKELY BE TEMPORARILY HELD UP AS OUTFLOW
FROM CONVECTION OVER OUR AREA RESULTS IN PREDOMINANTLY SOUTHERLY
WINDS ON ITS NORTH SIDE. FRONT PROBABLY WILL NOT REACH THE
METROPLEX UNTIL DAYBREAK AND WILL LIKELY PUSH INTO THE SOUTHERN ZONES
BY AFTERNOON. HIGH TEMPERATURES TOMORROW WILL BE TRICKY...WITH
LOCATIONS ALONG AND SOUTH OF THE FRONT IN THE AFTERNOON BENEFITING
FROM SUBSIDENCE WARMING AND THE TEMPS FORECAST HERE MAY BE TOO
LOW. ON THE OTHER HAND...CURRENT OBSERVATIONS SUGGEST THE FRONT
HAS A STRONG PUSH...AND THEREFORE AM LEANING TOWARD THE GUIDANCE
THAT SHOWS SOME DECENT COLD ADVECTION IN THE LOW LEVELS ACROSS THE
NORTH AND NORTHEAST ZONES. WILL RETAIN A MENTION OF LOW POPS IN
THE SOUTHERN ZONES TOMORROW WHERE THE FRONT SHOULD BECOME ACTIVE
IN THE AFTERNOON HOURS.
NORTHWEST FLOW ALOFT WILL REMAIN IN PLACE THROUGH TUESDAY. MODEL
GUIDANCE IS HAVING SOME TIMING DIFFERENCES WITH RESPECT TO THE
NEXT SHORTWAVE...EITHER AS EARLY AS TUESDAY MORNING AND AS LATE AS
OVERNIGHT TUESDAY. INSTABILITY/SHEAR WILL BE SUFFICIENT FOR A MCS
OR REMNANT MCS OUTFLOW TO AFFECT THE AREA FROM OKLAHOMA DURING
THIS TIME. WILL CONTINUE WITH SLIGHT CHANCE POPS TUESDAY AND TUESDAY
NIGHT. SOUTHERLY WINDS RETURN BY WEDNESDAY AND NORTHWEST FLOW
ALOFT WEAKENS. CONVECTIVE POTENTIAL SHOULD ALSO DIMINISH...WHILE
TEMPS RETURN TO NEAR 100 DEGREES AREA WIDE THROUGH THURSDAY.
IN THE EXTENDED...THE STRONGER COLD FRONT STILL LOOKS ON TRACK.
IT SHOULD ARRIVE FRIDAY MORNING AND GRADUALLY WORK SOUTH THROUGH
THE REGION INTO SATURDAY MORNING. WILL CONTINUE WITH LOW POPS
STARTING THURSDAY NIGHT IN THE NORTH...WITH 30 PERCENT EVERYWHERE
FRIDAY. WILL HAVE POPS GRADUALLY CLEAR OUT FROM NORTH TO SOUTH ON
SATURDAY. THE LINGERING POPS ON SATURDAY ARE FAVORING THE GFS
SOLUTION WHICH IS WEAKER WITH THE FRONT...AND MAKES SENSE GIVEN
THE TIME OF THE YEAR. THE WEAKER THE FRONT...THE LONGER IT WILL
TAKE FOR IT TO CLEAR OUT THE MOISTURE. REGARDLESS...HIGH
TEMPERATURES SHOULD DROP INTO THE LOW 90S THIS WEEKEND DUE TO
EITHER LOWER THICKNESS VALUES AND/OR INCREASED CLOUDS/RAIN.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 99 73 98 76 / 40 10 5 10 20
WACO, TX 77 101 72 100 76 / 20 10 10 10 10
PARIS, TX 73 97 66 95 70 / 40 10 5 10 20
DENTON, TX 73 98 67 97 72 / 30 5 5 20 20
MCKINNEY, TX 73 98 67 96 71 / 40 10 5 10 20
DALLAS, TX 78 99 74 98 76 / 40 10 5 10 20
TERRELL, TX 77 99 70 96 73 / 40 10 5 10 20
CORSICANA, TX 76 100 73 98 75 / 30 10 5 10 20
TEMPLE, TX 75 100 72 100 75 / 20 20 10 10 10
MINERAL WELLS, TX 71 100 66 99 71 / 30 5 5 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
823 PM CDT SUN AUG 12 2012
.UPDATE...
HAVE CANCELLED THE SEVERE THUNDERSTORM WARNING FOR AREAS ALONG AND
NORTHWEST OF A LINE FROM BRECKENRIDGE TO GAINESVILLE. POTENTIAL
FOR SEVERE WEATHER CONTINUES TO THE SOUTHEAST AND THE WATCH HAS
BEEN EXTENDED AS FAR SOUTH AS A LINE FROM COMANCHE TO HAMILTON TO
CORSICANA TO SULPHUR SPRINGS. NUMEROUS REPORTS OF WIND DAMAGE HAVE
BEEN RECEIVED. THE WIND THREAT WILL DECREASE SLOWLY AS THE EVENING
PROGRESSES AND SURFACE TEMPERATURES COOL. 84
&&
.AVIATION...
THUNDERSTORM THREAT WILL CONTINUE THROUGH THIS EVENING. OUTFLOW
WINDS WILL BE QUITE VARIABLE...AND LOCALLY STRONG MICROBURST
POTENTIAL WILL CONTINUE THROUGH AT LEAST 9 PM. OVERNIGHT...WINDS
WILL LIKELY RECOVER AND RETURN TO THE SOUTHWEST...AND AS WEAK COLD
FRONT APPROACHES NEAR SUNRISE (METROPLEX) WINDS WILL VEER WEST AND
THEN NORTH. 84
&&
.PREV UPDATE...
.UPDATE...
ISSUING A QUICK UPDATE TO INCLUDE SEVERE THUNDERSTORM WATCH 573 IN
THE PACKAGE. 84
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN AUG 12 2012/
ALTHOUGH THE PRIMARY MODEL GUIDANCE REMAINS IN DISAGREEMENT
REGARDING THE CONVECTIVE POTENTIAL THIS EVENING...SHORT-TERM
MESOSCALE TRENDS ARE SUGGESTING THAT THE WETTER NAM...HI-RES WRF
AND HRRR MODELS ARE ON THE RIGHT TRACK. THE COLD FRONT IS MAKING
STEADY PROGRESS TO THE SOUTH AND AT 3 PM HAS PASSED THROUGH
WICHITA FALLS. HOWEVER OBS AND RADAR INDICATE A REGION OF LOW
LEVEL CONFLUENCE FROM ABILENE TO GRAHAM TO BOWIE. THIS AREA WILL
BE THE FAVORABLE REGION FOR INITIATION...AND CONVECTION LOOKS LIKE
IT WILL INITIATE WELL AHEAD OF THE FRONT. LOCAL OBJECTIVE ANALYSIS
INDICATES AN AXIS OF 1000-2500 J/KG OF CAPE ALONG AND EAST OF A
LINE FROM GAINESVILLE TO MINERAL WELLS TO LAMPASAS...WHILE DEEP
LAYER SHEAR IS NOW RUNNING NEAR 35KT ACROSS MUCH OF THE AREA.
UNLIKE PREVIOUS SUMMERTIME CONVECTIVE EVENTS...IT HAS BEEN A
COUPLE MONTHS SINCE WE HAVE HAD THIS MUCH 0-6KM WIND SHEAR
AVAILABLE. GIVEN THE AVAILABLE INSTABILITY AND SHEAR...BRIEF
SUPERCELLS WILL BE POSSIBLE...BUT THE MOST LIKELY CONVECTIVE MODE
WILL BE LINE SEGMENTS. SURFACE TEMPERATURES ARE 105+ ACROSS THE NW
ZONES AHEAD OF THE FRONT...WHILE DEWPOINTS ARE IN THE MID 50S.
THIS WILL CREATE AN EXTREMELY FAVORABLE ENVIRONMENT FOR
DOWNBURSTS. DAMAGING WINDS WILL BE THE PRIMARY THREAT THIS
EVENING...AND BECAUSE DEEP LAYER SHEAR IS AVAILABLE IT WILL ALSO
ENHANCE THE POTENTIAL FOR LINE SEGMENTS PRODUCING ORGANIZED COLD
POOLS. STRONG OUTFLOW WINDS MAY IMPACT A MUCH WIDER AREA THAN
ACTUAL RAINFALL. WILL ALSO INCLUDE A MENTION OF HAIL IN
HWO..ALTHOUGH HOT TEMPS MAY LIMIT HAIL SIZE. THE SCATTERED
CONVECTION IS EXPECTED TO TRACK NORTHWEST TO SOUTHEAST ACROSS THE
CWA THIS EVENING...AND THE HIGHEST POPS WILL BE PLACED IN A BAND
ACROSS THE CENTRAL CWA.
THE TRUE COLD FRONT WILL LIKELY BE TEMPORARILY HELD UP AS OUTFLOW
FROM CONVECTION OVER OUR AREA RESULTS IN PREDOMINANTLY SOUTHERLY
WINDS ON ITS NORTH SIDE. FRONT PROBABLY WILL NOT REACH THE
METROPLEX UNTIL DAYBREAK AND WILL LIKELY PUSH INTO THE SOUTHERN ZONES
BY AFTERNOON. HIGH TEMPERATURES TOMORROW WILL BE TRICKY...WITH
LOCATIONS ALONG AND SOUTH OF THE FRONT IN THE AFTERNOON BENEFITING
FROM SUBSIDENCE WARMING AND THE TEMPS FORECAST HERE MAY BE TOO
LOW. ON THE OTHER HAND...CURRENT OBSERVATIONS SUGGEST THE FRONT
HAS A STRONG PUSH...AND THEREFORE AM LEANING TOWARD THE GUIDANCE
THAT SHOWS SOME DECENT COLD ADVECTION IN THE LOW LEVELS ACROSS THE
NORTH AND NORTHEAST ZONES. WILL RETAIN A MENTION OF LOW POPS IN
THE SOUTHERN ZONES TOMORROW WHERE THE FRONT SHOULD BECOME ACTIVE
IN THE AFTERNOON HOURS.
NORTHWEST FLOW ALOFT WILL REMAIN IN PLACE THROUGH TUESDAY. MODEL
GUIDANCE IS HAVING SOME TIMING DIFFERENCES WITH RESPECT TO THE
NEXT SHORTWAVE...EITHER AS EARLY AS TUESDAY MORNING AND AS LATE AS
OVERNIGHT TUESDAY. INSTABILITY/SHEAR WILL BE SUFFICIENT FOR A MCS
OR REMNANT MCS OUTFLOW TO AFFECT THE AREA FROM OKLAHOMA DURING
THIS TIME. WILL CONTINUE WITH SLIGHT CHANCE POPS TUESDAY AND TUESDAY
NIGHT. SOUTHERLY WINDS RETURN BY WEDNESDAY AND NORTHWEST FLOW
ALOFT WEAKENS. CONVECTIVE POTENTIAL SHOULD ALSO DIMINISH...WHILE
TEMPS RETURN TO NEAR 100 DEGREES AREA WIDE THROUGH THURSDAY.
IN THE EXTENDED...THE STRONGER COLD FRONT STILL LOOKS ON TRACK.
IT SHOULD ARRIVE FRIDAY MORNING AND GRADUALLY WORK SOUTH THROUGH
THE REGION INTO SATURDAY MORNING. WILL CONTINUE WITH LOW POPS
STARTING THURSDAY NIGHT IN THE NORTH...WITH 30 PERCENT EVERYWHERE
FRIDAY. WILL HAVE POPS GRADUALLY CLEAR OUT FROM NORTH TO SOUTH ON
SATURDAY. THE LINGERING POPS ON SATURDAY ARE FAVORING THE GFS
SOLUTION WHICH IS WEAKER WITH THE FRONT...AND MAKES SENSE GIVEN
THE TIME OF THE YEAR. THE WEAKER THE FRONT...THE LONGER IT WILL
TAKE FOR IT TO CLEAR OUT THE MOISTURE. REGARDLESS...HIGH
TEMPERATURES SHOULD DROP INTO THE LOW 90S THIS WEEKEND DUE TO
EITHER LOWER THICKNESS VALUES AND/OR INCREASED CLOUDS/RAIN.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 99 73 98 76 / 40 10 5 10 20
WACO, TX 77 101 72 100 76 / 20 10 10 10 10
PARIS, TX 73 97 66 95 70 / 40 10 5 10 20
DENTON, TX 73 98 67 97 72 / 30 5 5 20 20
MCKINNEY, TX 73 98 67 96 71 / 40 10 5 10 20
DALLAS, TX 78 99 74 98 76 / 40 10 5 10 20
TERRELL, TX 77 99 70 96 73 / 40 10 5 10 20
CORSICANA, TX 76 100 73 98 75 / 30 10 5 10 20
TEMPLE, TX 75 100 72 100 75 / 20 20 10 10 10
MINERAL WELLS, TX 71 100 66 99 71 / 30 5 5 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
621 PM CDT SUN AUG 12 2012
.AVIATION...
THUNDERSTORM THREAT WILL CONTINUE THROUGH THIS EVENING. OUTFLOW
WINDS WILL BE QUITE VARIABLE...AND LOCALLY STRONG MICROBURST
POTENTIAL WILL CONTINUE THROUGH AT LEAST 9 PM. OVERNIGHT...WINDS
WILL LIKELY RECOVER AND RETURN TO THE SOUTHWEST...AND AS WEAK COLD
FRONT APPROACHES NEAR SUNRISE (METROPLEX) WINDS WILL VEER WEST AND
THEN NORTH. 84
&&
.UPDATE...
ISSUING A QUICK UPDATE TO INCLUDE SEVERE THUNDERSTORM WATCH 573 IN
THE PACKAGE. 84
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN AUG 12 2012/
ALTHOUGH THE PRIMARY MODEL GUIDANCE REMAINS IN DISAGREEMENT
REGARDING THE CONVECTIVE POTENTIAL THIS EVENING...SHORT-TERM
MESOSCALE TRENDS ARE SUGGESTING THAT THE WETTER NAM...HI-RES WRF
AND HRRR MODELS ARE ON THE RIGHT TRACK. THE COLD FRONT IS MAKING
STEADY PROGRESS TO THE SOUTH AND AT 3 PM HAS PASSED THROUGH
WICHITA FALLS. HOWEVER OBS AND RADAR INDICATE A REGION OF LOW
LEVEL CONFLUENCE FROM ABILENE TO GRAHAM TO BOWIE. THIS AREA WILL
BE THE FAVORABLE REGION FOR INITIATION...AND CONVECTION LOOKS LIKE
IT WILL INITIATE WELL AHEAD OF THE FRONT. LOCAL OBJECTIVE ANALYSIS
INDICATES AN AXIS OF 1000-2500 J/KG OF CAPE ALONG AND EAST OF A
LINE FROM GAINESVILLE TO MINERAL WELLS TO LAMPASAS...WHILE DEEP
LAYER SHEAR IS NOW RUNNING NEAR 35KT ACROSS MUCH OF THE AREA.
UNLIKE PREVIOUS SUMMERTIME CONVECTIVE EVENTS...IT HAS BEEN A
COUPLE MONTHS SINCE WE HAVE HAD THIS MUCH 0-6KM WIND SHEAR
AVAILABLE. GIVEN THE AVAILABLE INSTABILITY AND SHEAR...BRIEF
SUPERCELLS WILL BE POSSIBLE...BUT THE MOST LIKELY CONVECTIVE MODE
WILL BE LINE SEGMENTS. SURFACE TEMPERATURES ARE 105+ ACROSS THE NW
ZONES AHEAD OF THE FRONT...WHILE DEWPOINTS ARE IN THE MID 50S.
THIS WILL CREATE AN EXTREMELY FAVORABLE ENVIRONMENT FOR
DOWNBURSTS. DAMAGING WINDS WILL BE THE PRIMARY THREAT THIS
EVENING...AND BECAUSE DEEP LAYER SHEAR IS AVAILABLE IT WILL ALSO
ENHANCE THE POTENTIAL FOR LINE SEGMENTS PRODUCING ORGANIZED COLD
POOLS. STRONG OUTFLOW WINDS MAY IMPACT A MUCH WIDER AREA THAN
ACTUAL RAINFALL. WILL ALSO INCLUDE A MENTION OF HAIL IN
HWO..ALTHOUGH HOT TEMPS MAY LIMIT HAIL SIZE. THE SCATTERED
CONVECTION IS EXPECTED TO TRACK NORTHWEST TO SOUTHEAST ACROSS THE
CWA THIS EVENING...AND THE HIGHEST POPS WILL BE PLACED IN A BAND
ACROSS THE CENTRAL CWA.
THE TRUE COLD FRONT WILL LIKELY BE TEMPORARILY HELD UP AS OUTFLOW
FROM CONVECTION OVER OUR AREA RESULTS IN PREDOMINANTLY SOUTHERLY
WINDS ON ITS NORTH SIDE. FRONT PROBABLY WILL NOT REACH THE
METROPLEX UNTIL DAYBREAK AND WILL LIKELY PUSH INTO THE SOUTHERN ZONES
BY AFTERNOON. HIGH TEMPERATURES TOMORROW WILL BE TRICKY...WITH
LOCATIONS ALONG AND SOUTH OF THE FRONT IN THE AFTERNOON BENEFITING
FROM SUBSIDENCE WARMING AND THE TEMPS FORECAST HERE MAY BE TOO
LOW. ON THE OTHER HAND...CURRENT OBSERVATIONS SUGGEST THE FRONT
HAS A STRONG PUSH...AND THEREFORE AM LEANING TOWARD THE GUIDANCE
THAT SHOWS SOME DECENT COLD ADVECTION IN THE LOW LEVELS ACROSS THE
NORTH AND NORTHEAST ZONES. WILL RETAIN A MENTION OF LOW POPS IN
THE SOUTHERN ZONES TOMORROW WHERE THE FRONT SHOULD BECOME ACTIVE
IN THE AFTERNOON HOURS.
NORTHWEST FLOW ALOFT WILL REMAIN IN PLACE THROUGH TUESDAY. MODEL
GUIDANCE IS HAVING SOME TIMING DIFFERENCES WITH RESPECT TO THE
NEXT SHORTWAVE...EITHER AS EARLY AS TUESDAY MORNING AND AS LATE AS
OVERNIGHT TUESDAY. INSTABILITY/SHEAR WILL BE SUFFICIENT FOR A MCS
OR REMNANT MCS OUTFLOW TO AFFECT THE AREA FROM OKLAHOMA DURING
THIS TIME. WILL CONTINUE WITH SLIGHT CHANCE POPS TUESDAY AND TUESDAY
NIGHT. SOUTHERLY WINDS RETURN BY WEDNESDAY AND NORTHWEST FLOW
ALOFT WEAKENS. CONVECTIVE POTENTIAL SHOULD ALSO DIMINISH...WHILE
TEMPS RETURN TO NEAR 100 DEGREES AREA WIDE THROUGH THURSDAY.
IN THE EXTENDED...THE STRONGER COLD FRONT STILL LOOKS ON TRACK.
IT SHOULD ARRIVE FRIDAY MORNING AND GRADUALLY WORK SOUTH THROUGH
THE REGION INTO SATURDAY MORNING. WILL CONTINUE WITH LOW POPS
STARTING THURSDAY NIGHT IN THE NORTH...WITH 30 PERCENT EVERYWHERE
FRIDAY. WILL HAVE POPS GRADUALLY CLEAR OUT FROM NORTH TO SOUTH ON
SATURDAY. THE LINGERING POPS ON SATURDAY ARE FAVORING THE GFS
SOLUTION WHICH IS WEAKER WITH THE FRONT...AND MAKES SENSE GIVEN
THE TIME OF THE YEAR. THE WEAKER THE FRONT...THE LONGER IT WILL
TAKE FOR IT TO CLEAR OUT THE MOISTURE. REGARDLESS...HIGH
TEMPERATURES SHOULD DROP INTO THE LOW 90S THIS WEEKEND DUE TO
EITHER LOWER THICKNESS VALUES AND/OR INCREASED CLOUDS/RAIN.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 99 73 98 76 / 40 10 5 10 20
WACO, TX 77 101 72 100 76 / 20 10 10 10 10
PARIS, TX 73 97 66 95 70 / 40 10 5 10 20
DENTON, TX 73 98 67 97 72 / 30 5 5 20 20
MCKINNEY, TX 73 98 67 96 71 / 40 10 5 10 20
DALLAS, TX 78 99 74 98 76 / 40 10 5 10 20
TERRELL, TX 77 99 70 96 73 / 40 10 5 10 20
CORSICANA, TX 76 100 73 98 75 / 30 10 5 10 20
TEMPLE, TX 75 100 72 100 75 / 20 20 10 10 10
MINERAL WELLS, TX 71 100 66 99 71 / 30 5 5 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
648 PM CDT SUN AUG 12 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
TROUGHING MOVING EAST OVER IOWA AND MINNESOTA AND SURFACE LOW
PRESSURE CENTERED OVER NE KANSAS EARLY THIS AFTERNOON. ARCING BAND
OF PRECIP STRETCHING FROM SOUTHERN MINNESOTA TO WESTERN ILLINOIS HAS
GENERALLY BEEN DECAYING AS IT MOVES INTO DRIER AIR OVER WISCONSIN.
A SECONDARY AND MORE POTENT BAND IS MOVING NE OVER NORTHEAST IOWA
WHILE ANOTHER AREA OF PRECIP EXISTS OVER EASTERN NORTH DAKOTA WITHIN
THE COMMA HEAD OF THE SHORTWAVE AND ALONG A CANADIAN COOL FRONT. AS
THE SHORTWAVE ENERGY MOVES EAST OVER THE STATE...PRECIP CHANCES ARE
THE MAIN FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL MOVE EAST
INTO THE STATE OF WISCONSIN TONIGHT. ASSOCIATED ELONGATED SURFACE
LOW WILL ALSO MOVE EAST INTO ILLINOIS. THE LATEST NAM AND ECMWF
SHOW 300K ISENTROPIC ASCENT AND FGEN WILL REMAIN OVER NORTHERN
ILLINOIS AND SOUTHERN WISCONSIN TONIGHT...WHERE THE LOW LEVEL
MOISTURE WILL ALSO BE THE MOST ABUNDANT. PROGGED SOUNDINGS AND
UPSTREAM OBS CONTINUE TO SHOW DRY WEDGES BELOW 700MB WHERE THE
ATMOSPHERE STRUGGLES TO SATURATE BELOW 10KFT. WILL STILL HAVE THE
MID-LEVEL WAVE MOVE OVERHEAD THOUGH...SO SPRINKLES OR LIGHT SHOWERS
CANNOT BE RULED OUT. BUT WILL PLACE THE HIGHEST PROBABILITY OF
SHOWERS OVER CENTRAL AND EAST-CENTRAL WISCONSIN...THOUGH THE
PROBABILITY WILL ONLY BE IN THE LOW CHANCE RANGE. A MOSTLY CLOUDY
NIGHT WITH LOWS IN THE MID 50S TO LOW 60S.
MONDAY...THE SHORTWAVE TROUGH WILL SLOWLY MOVE ACROSS CENTRAL AND
EASTERN WISCONSIN IN THE MORNING AND EASTERN WISCONSIN AND LAKE
MICHIGAN IN THE AFTERNOON. NOT QUITE AS BULLISH IN QPF AS THE SREF
OR THE GFS SINCE THINK THAT LOW LEVEL FORCING WILL RESIDE FARTHER
SOUTH. BUT STILL LOOKS LIKE THE BEST CHANCES OF PRECIP WILL OCCUR
IN THE MORNING WHEN EAST-CENTRAL WISCONSIN WILL BE ON THE NORTHERN
PERIPHERY OF THE DEEPER MOISTURE...AND THE COMMA HEAD OF THE
SHORTWAVE MOVES OVER NORTH-CENTRAL WISCONSIN. SOME INTERACTION WITH
DAYTIME INSTABILITY APPEARS POSSIBLE AS ML CAPES UP TO 400 J/KG WILL
BE POSSIBLE BY MIDDAY. WILL KEEP A CHANCE IN THE AFTERNOON TO
ACCOUNT FOR ANY DIURNAL INSTABILITY ACTIVITY. PLENTY OF CLOUD COVER
WILL KEEP HIGHS IN THE LOW TO MID 70S.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. UPPER TROUGH WILL
EXIT THE AREA MONDAY NIGHT AND SCATTERED SHOWERS WILL END. THEN
MAINLY DRY NORTHWEST UPPER FLOW EXPECTED TUESDAY THROUGH
WEDNESDAY. THERE COULD BE ISOLATED OR WIDELY SCATTERED SHOWERS
TUESDAY AFTERNOON BUT LEFT THEM OUT OF THE FORECAST FOR NOW. A
SIGNIFICANT UPPER TROUGH WILL APPROACH THE REGION WEDNESDAY NIGHT
AND THURSDAY. THERE CONTINUES TO BE TIMING DIFFERENCES BETWEEN THE
MEDIUM RANGE MODELS SO DID NOT GO WITH LIKELY PROBABILITIES OF
PRECIPITATION AS THERE IS UNCERTAINTY AS TO WHICH PERIOD(S) RAIN
WILL FALL. EITHER WAY IT WILL BE MILDER AND A LITTLE MORE HUMID
WEDNESDAY AS WINDS BECOME SOUTH AND MOISTURE INCREASES. THE UPPER
TROUGH REALLY ESTABLISHES ITSELF ACROSS THE GREAT LAKES FRIDAY
THROUGH SUNDAY. WE MAY SEE THE FIRST PERIOD OF COOLER THAN NORMAL
WEATHER THIS SUMMER THAT LASTS MORE THAN A DAY OR TWO. FROST LOOKS
POSSIBLE FRIDAY NIGHT IN NORTHERN WISCONSIN WITH BIG SURFACE HIGH
OVERHEAD AND LOW DEW POINTS. MENTIONED THIS POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.AVIATION...A LOW PRESSURE SYSTEM WILL TRACK WELL SOUTH OF THE REGION
TONIGHT INTO MONDAY...TAKING MOST OF THE RAIN SOUTH OF THE FORECAST
AREA. SOME LIGHT SHOWER ACTIVITY MAY BRUSH PARTS OF C/EC WI LATE
TONIGHT INOT EARLY MONDAY. AN UPPER LEVEL TROF AND WEAK SFC COLD FRONT
WILL PASS THROUGH THE AREA ON MONDAY...AND SHOULD BRING SCATTERED
SHOWERS TO THE ENTIRE REGION. A FEW TSTMS ARE POSSIBLE...ESPECIALLY
OVER NORTHERN WI...ALTHOUGH THE PROBABILITY IS TOO LOW TO ADD TO
THE RHI TAF AT THIS TIME. WILL CONTINUE TO FCST VFR CONDITIONS
THROUGH THE TAF PERIOD...AS CIGS AND VSBYS ARE MOSTLY VFR UPSTREAM.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT SAT AUG 11 2012
.SHORT TERM...TONIGHT AND SUNDAY
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH PRESSURE
STRETCHING ALONG THE MISSISSIPPI VALLEY TO HUDSON BAY WHILE LOW
PRESURE IS MOVING OVER THE DAKOTAS AND ALSO LAKE ERIE. WITH HIGH
PRESSURE OVER THE REGION...MOSTLY CLEAR SKIES HAVE PREVAILED ACROSS
THE FORECAST AREA THROUGH EARLY THIS AFTERNOON. MID AND HIGH CLOUDS
ARE ALREADY ADVANCING ACROSS THE NORTHERN MISSISSIPPI VALLEY AHEAD
OF THE NEXT STORM SYTEM OVER THE NORTHERN PLAINS. AS THE STORM
SYSTEM CONTINUES TO MOVE EAST...LIGHT PRECIP CHANCES TOMORROW ALONG
WITH CLOUDS AND TEMPS ARE THE MAIN FORECAST CONCERNS.
TONIGHT...HIGH PRESSURE WILL REMAIN AT THE SURFACE ACROSS THE
WESTERN GREAT LAKES TONIGHT. HOWEVER...A SHORTWAVE TROUGH OVER THE
NORTHERN PLAINS WILL MOVE INTO THE NORTHERN MISSISSIPPI VALLEY
TONIGHT. A BLANKET OF MID AND HIGH CLOUDS WILL SPREAD ACROSS
CENTRAL AND EASTERN PORTIONS OF THE STATE LATE THIS EVENING THROUGH
THE OVERNIGHT. WITH DEWPOINTS MIXING OUT THIS AFTERNOON...POCKETS
OF GROUND FOG SHOULD ONLY BE NUISANCE LATE AND NOT EXPECTING
ANYTHING DENSE TO FORM. LOWS IN THE MID 40S NORTH TO MID 50S SOUTH.
SUNDAY...THE SHORTWAVE WILL PROCEED TO MOVE INTO THE STATE AND WILL
SEE A PRETTY THICK LAYER OF MID AND HIGH CLOUDS OVERHEAD. LOW LEVEL
MOISTURE WILL HANG TO THE WEST THOUGH CLOSER TO A SURFACE LOW OVER
IOWA. PROGGED SOUNDINGS REMAIN FAIRLY DRY BELOW 700MB...SO IF ANY
PRECIP WERE TO FALL OUT OF THE MID DECK...IT SHOULD ONLY BE
SPRINKLES. ADDED SPRINKLES OVER CENTRAL WISCONSIN FOR THE AFTERNOON.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY. MODELS ARE IN
DECENT AGREEMENT WITH THE UPPER PATTERN THROUGH THE MIDDLE OF NEXT
WEEK THEN THE GFS AND ECMWF DIFFER IN HOW THEY HANDLE A
SIGNIFICANT UPPER TROUGH AS IT MOVES ACROSS THE GREAT LAKES. THE
ECMWF HAS A SHARPER UPPER TROUGH AND CLOSES OFF AN UPPER LOW OVER
LOWER MICHIGAN WHILE THE GFS TROUGH IS BROADER.
A WEAK UPPER TROUGH MOVING ACROSS THE AREA SUNDAY NIGHT AND MONDAY
SHOULD PRODUCE AT LEAST SCATTERED SHOWERS AND THUNDERSTORMS DESPITE
THE SURFACE LOW BEING WELL SOUTH OF OUR AREA OVER ILLINOIS. HIGHS
MONDAY COULD BE COOLER THAN WHAT WE CURRENTLY HAVE IN THE FORECAST
IF SKIES ARE CLOUDY AND SHOWERS MORE ABUNDANT THAN NOW FORECAST.
THEN NORTHWEST UPPER FLOW SHOULD PROVIDE FOR DRY AND SEASONABLE
WEATHER FOR TUESDAY AND WEDNESDAY.
A SIGNIFICANT UPPER TROUGH WILL APPROACH WEDNESDAY NIGHT AND
THURSDAY AND PROVIDE SUFFICIENT UPPER SUPPORT FOR SHOWERS AND
THUNDERSTORMS. MODELS SUGGEST THERE WILL BE DECENT MID LEVEL WINDS
AND SHEAR BUT INSTABILITY IS MODEST. AFTER THAT GOES BY SOME
COOLER THAN NORMAL AIR WILL ARRIVE FOR THE END OF THE WEEK. GFS
FORECASTS SUBZERO 850 MB TEMPERATURES IN NORTHERN WISCONSIN FRIDAY
AFTERNOON.
&&
.AVIATION...HIGH PRESSURE AT THE SURFACE WILL PROVIDE MOSTLY CLEAR
CONDITIONS THROUGH THIS EVENING. WILL THEN SEE INCREASING MID AND
HIGH CLOUDS OVERNIGHT INTO SUNDAY AHEAD OF THE NEXT SYSTEM.
CONDITIONS TO REMAIN VFR OVER THE PERIOD...THOUGH PATCHY IFR VSBYS
IN GROUND FOG IS POSSIBLE OVER NORTH-CENTRAL WISCONSIN LATE TONIGHT.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
313 AM CDT SAT AUG 11 2012
.SHORT TERM...TONIGHT THROUGH MONDAY NIGHT
313 AM CDT SAT AUG 11 2012
MAIN FORECAST CHALLENGE IS ON RAIN CHANCES SUNDAY THROUGH MONDAY.
07Z SURFACE ANALYSIS SHOWS HIGH PRESSURE CENTERED FROM SOUTHERN
ONTARIO...SOUTHWARD INTO SOUTHERN MINNESOTA. AIRMASS WAS RELATIVELY
DRY...WITH MANY OF THE VALLEY LOCATIONS STILL SEEING 7 TO 8 DEGREE
TEMPERATURE DEWPOINT SPREADS. GRADIENT HAS ALSO BEEN STRONG ENOUGH
TO KEEP LOW LEVELS MIXED AND THUS NO FOG IS BEING REPORTED.
ANOTHER NICE DAY IS IN STORE FOR THE AREA TODAY. HIGH PRESSURE WILL
REMAIN OVERHEAD RESULTING IN ANOTHER DAY WITH LOTS OF SUNSHINE AND
TEMPERATURES SIMILAR TO YESTERDAYS.
A SHORTWAVE WILL DROP ACROSS THE PLAINS LATER TODAY AND BECOME THE
MAIN WEATHER INFLUENCE FOR TONIGHT THROUGH MONDAY. CLOUDS WILL
INCREASE TONIGHT WITH SHOWERS APPROACHING THE WESTERN SECTIONS OF THE
AREA BY 12Z SUNDAY. WAVE THEN TRANSLATES ACROSS IOWA...WITH THE
STRONGEST FORCING REMAINING ACROSS THE SOUTHWEST HALF OF THE
FORECAST AREA...ESPECIALLY NORTHEAST IOWA AND SOUTHWEST WISCONSIN.
MOISTURE TRANSPORT FOCUSES INTO THIS AREAS AS WELL...ESPECIALLY
SUNDAY NIGHT WITH PRECIPITABLE WATER VALUES INCREASING TO NEAR 1
INCH. WITH THE ATTENDANT SURFACE LOW TRACKING ACROSS SOUTHERN IOWA
SUNDAY NIGHT...COULD BE SOME SUBSTANTIAL RAINS IN THE DEFORMATION
AREA THAT WILL BE LOCATED OVER NORTHEAST IOWA AND SOUTHWEST
WISCONSIN. GFS INDICATING RATHER STRONG BAND OF FRONTOGENETIC
FORCING NORTH OF THE LOW. DID RAISE BOTH PROBABILITIES AND QPF
AMOUNTS FROM SUNDAY THROUGH MONDAY. LESSER PROBABILITIES FURTHER
NORTH...WHERE FORCING IS WEAKEST AND LOW LAYERS APPEAR TO REMAIN
RATHER DRY. INSTABILITIES VERY LIMITED SO EXPECT ONLY ISOLATED
THUNDERSTORMS AT BEST.
SHORTWAVE DOES PUSH EAST ON MONDAY AS HIGH PRESSURE BUILDS INTO THE
REGION. PROBABILITIES WILL TAPER OFF MONDAY NIGHT AS SUBSIDENCE
OVERTAKES THE AREA.
TEMPERATURES COULD BE RATHER TRICKY SUNDAY AND MONDAY WITH THE
CLOUDS AND SHOWERS. GUIDANCE NUMBERS SUGGEST HIGHS JUST IN THE LOWER
70S IN THE RAIN AREA...WITH MID 70S FURTHER NORTH AND EAST.
.LONG TERM...TUESDAY THROUGH FRIDAY
313 AM CDT SAT AUG 11 2012
THE FLOW WILL BE RATHER PROGRESSIVE THROUGH THE PERIOD. INITIAL WAVE
WILL PUSH EAST OF THE AREA ON TUESDAY...WITH HIGH PRESSURE SETTLING
IN OVER THE AREA. THIS WILL BE SHORT LIVED AS THE NEXT SHORTWAVE
BEGINS TO DIG ACROSS THE PLAINS AND THEN ROTATES ACROSS THE REGION
WEDNESDAY THROUGH THURSDAY WITH THE ATTENDANT COLD FRONT PUSHING
THROUGH WEDNESDAY NIGHT. SURFACE HIGH PRESSURE THEN BUILDS IN FOR
FRIDAY. RAIN CHANCES LOOK BEST FOR WEDNESDAY NIGHT INTO THURSDAY.
&&
.AVIATION...THROUGH 06Z SUNDAY
1153 PM CDT FRI AUG 10 2012
HIGH PRESSURE...CURRENTLY CENTERED OVER CENTRAL MINNESOTA...WILL
BUILD SOUTHEAST INTO THE REGION OVERNIGHT. WHILE THE WINDS IN THE
BOUNDARY LAYER WILL LIKELY DECOUPLE AND GO CALM AFTER
MIDNIGHT...THE RAP CONTINUES TO SUGGEST THAT THE WINDS JUST ABOVE
THE BOUNDARY LAYER WILL BE NORTHEAST AT 10 TO 15 KNOTS. IN ADDITION...
THE SOUNDINGS DO NOT SHOW MUCH MOISTURE IN THE BOUNDARY LAYER AT
ALL. THINKING THAT IF ANY FOG DOES DEVELOP IN THE MISSISSIPPI
RIVER VALLEY...IT WILL BE SCATTERED AND VERY SHALLOW. AS A RESULT...
KEPT A BCFG IN THE KLSE TAF...BUT WOULD NOT BE SURPRISED AT ALL
THAT NO FOG DEVELOPS THERE. MEANWHILE FURTHER SOUTH...EXPECT TO
SEE SOME VALLEY FOG DEVELOP IN THE WISCONSIN AND KICKAPOO RIVER
VALLEY AFTER 11.06Z AND DISSIPATE AROUND 11.13Z. ADDITIONAL AREAS
OF FOG WILL BE POSSIBLE ACROSS CENTRAL WISCONSIN ESPECIALLY NEAR
KVOK AND KBCK.
ON SATURDAY AFTERNOON AND EVENING...A LOW PRESSURE SYSTEM WILL
APPROACH THE REGION. THIS SYSTEM WILL BRING AN INCREASE IN THE
HIGH CLOUDS ACROSS THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
313 AM CDT SAT AUG 11 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RABERDING
LONG TERM...RABERDING
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1153 PM CDT FRI AUG 10 2012
.SHORT TERM...TONIGHT
929 PM CDT FRI AUG 10 2012
STILL HAVE NOT SEEN MUCH RECOVERY IN THE DEW POINTS THIS EVENING.
IN MOST LOCATIONS...THE DEW POINTS HAVE ONLY CLIMBED 2 DEGREES.
WITH THE EXCEPTION OF KVOK...KTOB..KOVS...AND KFKA...THE
TEMPERATURE/DEW POINT SPREADS ARE GREATER THAN 10 DEGREES.
WITH SURFACE RIDGE BUILDING SOUTHEAST ACROSS THE AREA...THE
SURFACE WINDS HAVE DECREASED AS EXPECTED. HOWEVER THERE IS STILL
A 10 TO 15 KNOT WIND AT THE OFFICE AND THE RAP CONTINUES TO SHOW
THESE WINDS WILL REMAIN LIKE THIS ALL NIGHT. AS A RESULT...
THINKING THAT THE FOG POSSIBILITY AT KLSE IS NOT THAT GREAT.
THIS WILL LIKELY THE CASE IN THE ENTIRE UPPER MISSISSIPPI RIVER
VALLEY. ONE CASE THAT LOOKS LIKELY TO SEE VALLEY FOG WILL BE
IN THE WISCONSIN AND THE LOWER PORTION OF KICKAPOO RIVER VALLEY.
ALSO WOULD NOT BE SURPRISED TO SEE SOME FOG NEAR VOLK FIELD.
.LONG TERM...TUESDAY THROUGH FRIDAY
253 PM CDT FRI AUG 10 2012
10.12 MEDIUM RANGE MODELS ARE IN REASONABLE AGREEMENT TUESDAY
THROUGH EARLY THURSDAY THEN DIVERGE GREATLY LATE THURSDAY THROUGH
FRIDAY. A BRIEF WARM UP IS IN STORE FOR THE AREA TUESDAY INTO
WEDNESDAY WITH HIGHS REBOUNDING INTO THE LOWER 80S. A STRONG COLD
FRONT IS EXPECTED TO PUSH INTO THE AREA DURING THE DAY ON THURSDAY
BRINGING SHOWERS AND THUNDERSTORMS TO THE AREA. STRONG SHEAR APPEARS
TO BE LACKING WITH THE LATEST SET OF FORECAST MODEL RUNS DURING THE
DAY ON THURSDAY WITH THE STRONGEST SHEAR WELL BEHIND THE COLD FRONT.
DETAILS THIS FAR OUT ARE UNCLEAR WITH THE VARYING MODEL SOLUTIONS SO
DIFFICULT TO DETERMINE SEVERE WEATHER POTENTIAL WITH THIS SYSTEM.
MODELS ARE POINTING TOWARDS A COOL DOWN FOR LATE NEXT WEEK BEHIND
THE FRONT AS A LONG WAVE TROUGH DEVELOPS ACROSS THE UPPER
MIDWEST/GREAT LAKES. AT THIS TIME IT APPEARS THAT HIGHS WILL STRUGGLE
TO GET OUT OF THE 60S ON FRIDAY.
&&
.AVIATION...THROUGH 06Z SUNDAY
1153 PM CDT FRI AUG 10 2012
HIGH PRESSURE...CURRENTLY CENTERED OVER CENTRAL MINNESOTA...WILL
BUILD SOUTHEAST INTO THE REGION OVERNIGHT. WHILE THE WINDS IN THE
BOUNDARY LAYER WILL LIKELY DECOUPLE AND GO CALM AFTER
MIDNIGHT...THE RAP CONTINUES TO SUGGEST THAT THE WINDS JUST ABOVE
THE BOUNDARY LAYER WILL BE NORTHEAST AT 10 TO 15 KNOTS. IN ADDITION...
THE SOUNDINGS DO NOT SHOW MUCH MOISTURE IN THE BOUNDARY LAYER AT
ALL. THINKING THAT IF ANY FOG DOES DEVELOP IN THE MISSISSIPPI
RIVER VALLEY...IT WILL BE SCATTERED AND VERY SHALLOW. AS A RESULT...
KEPT A BCFG IN THE KLSE TAF...BUT WOULD NOT BE SURPRISED AT ALL
THAT NO FOG DEVELOPS THERE. MEANWHILE FURTHER SOUTH...EXPECT TO
SEE SOME VALLEY FOG DEVELOP IN THE WISCONSIN AND KICKAPOO RIVER
VALLEY AFTER 11.06Z AND DISSIPATE AROUND 11.13Z. ADDITIONAL AREAS
OF FOG WILL BE POSSIBLE ACROSS CENTRAL WISCONSIN ESPECIALLY NEAR
KVOK AND KBCK.
ON SATURDAY AFTERNOON AND EVENING...A LOW PRESSURE SYSTEM WILL
APPROACH THE REGION. THIS SYSTEM WILL BRING AN INCREASE IN THE
HIGH CLOUDS ACROSS THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
253 PM CDT FRI AUG 10 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...WETENKAMP
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS TUCSON AZ
222 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.DISCUSSION...KIND OF AN INTERESTING DAY ON TAP FOR SOUTHEAST
ARIZONA. FIRST THERE IS A BACK DOOR COLD FRONT AND SEVERAL OUTFLOW
BOUNDARIES MOVING THROUGH SOUTHWEST NEW MEXICO WHICH HAS DEVELOPED
ISOLATED THUNDERSTORMS. LATEST HRRR RUNS INDICATE THAT THERE WILL BE
SOME WEAK SHOWERS...POSSIBLY A THUNDERSTORM...ALONG/NEAR THE AZ/NM
BORDER THIS MORNING. BASED ON WHAT IS CURRENTLY OCCURRING IN SE NEW
MEXICO...WILL UP POPS THIS MORNING ALONG/NEAR THE AZ/NM BORDER. FOR
THE REMAINDER OF TODAY...STILL RATHER DRY WITH PW VALUES AROUND ONE
INCH. STORMS FOR THE MOST PART WILL BE NEAR THE HIGHER TERRAIN. IF A
FEW DO MOVE INTO THE VALLEYS...THE COULD BE SEVERE DUE TO A VERY HOT
BOUNDARY LAYER. THE OTHER STORY FOR TODAY WILL BE THE CONTINUE VERY
HOT TEMPERATURES FOR MID AUGUST. HIGHS TODAY WILL BE SIMILAR TO WHAT
OCCURRED SUNDAY WITH HEAT ADVISORY IN EFFECT FOR THE LOWER
ELEVATIONS OF PIMA AND PINAL COUNTIES.
FOR THE REMAINDER OF THE WEEK...WILL SEE A GRADUAL INCREASE IN
MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL STORM HECTOR NO LONGER
WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT DID INCREASE MOISTURE
OVER THE SOUTHERN PARTS OF THE GULF OF CALIFORNIA ON SUNDAY. THE
GULF REMAINS VERY MOIST WITH PW VALUES OVER 1.50". WILL SEE MORE
THUNDERSTORM COMPLEXES DEVELOP OVER SONORA MEXICO...SENDING LOW
LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS SOUTHERN ARIZONA AND
ALSO PUSHING OUTFLOWS INTO THE GULF WITH RESULTANT INCREASE IN LOW
LEVEL MOISTURE INTO THE LOWER DESERTS. DIDN`T MAKE MANY CHANGES TO
THE INHERITED FORECAST AS IT HAD A VERY GOOD HANDLE ON THE TRENDS
FOR THE WEEK. WILL THERE BE DAILY CHANGES. SURE...BUT OVERALL THE
FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA MAINLY FROM KTUS EWD/SWD INTO THIS
EVENING. OTHERWISE...VFR CONDITIONS AND SURFACE WIND GENERALLY LESS
THAN 10 KTS THRU MIDNIGHT OR 14/07Z. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1142 PM CDT SUN AUG 12 2012
.DISCUSSION...
ISSUED 910 PM CDT SUN AUG 12 2012
EARLIER SPRINKLES HAVE EXITED THE AREA. NEXT ROUND OF SHOWERS HAS
BEEN INCREASING NORTHWEST OF THE ILLINOIS RIVER OVER THE LAST HOUR
OR TWO...WITH SOME EMBEDDED THUNDERSTORMS MAINLY IN AREAS NEAR AND
NORTHWEST OF QUINCY. BULK OF THE RAIN HAS BEEN ALONG AND NORTH OF
A WARM FRONT/TROUGH THAT EXTENDS ACROSS NORTHERN MISSOURI TO NEAR
BLOOMINGTON. LATEST HRRR GUIDANCE HAS BEEN DOING A REASONABLE JOB
WITH THE COVERAGE OF THESE SHOWERS...AND SHOWS THE HIGHEST RAIN
CHANCES OVER THE NORTHERN HALF OF THE CWA OVER THE NEXT SEVERAL
HOURS. SOUTH OF THE BOUNDARY...SCATTERED SHOWERS AND STORMS HAVE
BEEN DEVELOPING AHEAD OF A COLD FRONT WHICH EXTENDS SOUTHWEST TO
NORTHEAST ACROSS MISSOURI. IT WILL LIKELY TAKE UNTIL AFTER
MIDNIGHT BEFORE THESE REACH THE SOUTHEAST CWA. THE SHOWERS WILL
PROBABLY BE EXITING THE SOUTHEAST CWA SHORTLY BEFORE SUNRISE... AS
SOME DRY SLOTTING TAKES PLACE OVER WEST CENTRAL ILLINOIS.
UPDATED ZONES/GRIDS HAVE BEEN SENT.
GEELHART
&&
.AVIATION...
ISSUED 1140 PM CDT SUN AUG 12 2012
MAIN CONCERN FOR THIS TAF PERIOD WILL BE PINNING DOWN CONVECTION
TIMING/ENDING AT THE TERMINALS...AS LOW PRESSURE SYSTEM EDGES TO
THE EAST AND DRAGS A COLD FRONT ACROSS THE AREA ON MONDAY. CURRENT
RADAR TRENDS SHOW AN AREA OF SHOWERS AND THUNDERSTORMS STEADILY
PROGRESSING EASTWARD. LATEST MODEL RUNS SHOW FAIRLY WIDESPREAD
SHOWERS PERSISTING THROUGH AROUND 12Z AT PIA...AND AROUND 14Z AT
CMI. CIGS WILL ALSO BE A CONCERN...AS MODEL SOUNDINGS HINT THAT
SOME MVFR CIGS MIGHT DEVELOP LATE MORNING INTO THE AFTERNOON AND
HANG AROUND FOR MOST OF THE DAY. CMI/BMI/DEC MIGHT SEE THESE
CONDITIONS CONTINUE INTO THE OVERNIGHT AS THEY REMAIN IN CLOSER
PROXIMITY TO THE LOW.
WINDS WILL GENERALLY BE LIGHT OUT OF THE EAST/SOUTHEAST...AND THEN
BECOME NORTHERLY AND PICK UP SPEED AFTER FRONTAL PASSAGE.
ECT/GEELHART
&&
.PREV DISCUSSION...
ISSUED 259 PM CDT SUN AUG 12 2012
ANOTHER RELATIVELY COOL DAY ACROSS MOST OF CENTRAL ILLINOIS...
WHILE SOUTHEAST ILLINOIS IS WARMER DUE TO RECEIVING MORE SUN
BEFORE THE CLOUDS MOVED IN. THESE CLOUDS ARE ASSOCIATED WITH AN
APPROACHING CLIPPER TYPE SYSTEM...SOMEWHAT UNUSUAL FOR THE MIDDLE
OF SUMMER...THAT IS EXPECTED TO IMPACT THE AREA FOR THE NEXT 24-36
HOURS. MAIN FORECAST CONCERNS TODAY REVOLVE AROUND PRECIPITATION
CHANCES AND TEMPERATURES WHILE THIS SYSTEM MOVES THROUGH. OTHER
THAN THAT...THE WEATHER FOR THE COMING WEEK IS RATHER QUIET..WITH
THE EXCEPTION BEING A STRONG FRONTAL PASSAGE AROUND THURSDAY NIGHT
AND THE ASSOCIATED RISK OF SHOWERS/STORMS. TEMPERATURES WILL
AVERAGE COOLER THAN NORMAL FOR MUCH OF THE WEEK...ESPECIALLY BY
NEXT WEEKEND...A RARE OCCURRENCE THIS SUMMER..
12Z MODELS IN GOOD AGREEMENT OVERALL. HOWEVER...THE GFS HAS BEEN
IGNORED FOR THE APPROACHING SYSTEM. THE MORE SOUTHERN SURFACE LOW
TRACK ADVERTISED BY THE MODEL CONSENSUS IS SUPPORTED BY RECENT
SURFACE PRESSURE FALLS AND MAKES MORE SENSE CONSIDERING THE LOW
LEVEL THERMAL FIELD.
SHORT TERM...TONIGHT THROUGH WEDNESDAY...THE UPSTREAM SYSTEM IS
PROGGED TO TRACK THROUGH THE LOWER MIDWEST...WITH THE SURFACE
LOW TRACKING IN THE VICINITY OF THE MO/IL BORDER. WEAK
WAA/ISENTROPIC LIFT IN ADVANCE OF THE SYSTEM HAS RESULTED IN
ABUNDANT MID/HIGH LEVEL CLOUDINESS AND SOME LIGHT SHOWERS. MANY OF
THE ECHOES ON RADAR ARE NOT REACHING THE GROUND OR ONLY FALLING AS
VERY LIGHT SPRINKLES DUE TO A DRY LOW LEVEL AIRMASS. WHILE MOST OF
THE FORECAST AREA SHOULD BE NORTH OF THE SURFACE LOW TRACK...THE
EXPECTED FORCING AND MOISTURE AVAILABILITY AS THE SYSTEM MOVES
THROUGH SHOULD PRECLUDE SIGNIFICANT RAINFALL. WATER VAPOR IMAGERY
IS ALREADY SHOWING DRY AIR BEING WRAPPED INTO UPPER WAVE WHICH IS
NOT GOING TO BE CONDUCIVE FOR IT BEING A GOOD RAIN PRODUCER.
PRECIPITATION CHANCES WILL END FROM WEST TO EAST MONDAY AS THE
SYSTEM DEPARTS.
HIGH PRESSURE AT THE SURFACE AND NEUTRAL FLOW ALOFT WILL BUILD IN
BEHIND THE EARLY WEEK SYSTEM AND PROVIDE QUIET WEATHER.
TEMPERATURES WILL MODERATE EACH DAY...WITH WEDNESDAY EXPECTED TO
BE THE HOTTEST DAY OF THE WEEK WITH THE BEST COMBINATION OF
SUNSHINE AND SOUTHERLY RETURN FLOW.
LONG TERM...THURSDAY THROUGH SUNDAY...A VIGOROUS WAVE/STRONG COLD
FRONT IS PROGGED TO ARRIVE AROUND THURSDAY NIGHT. THERE HAS BEEN A
SLIGHTLY SLOWER TREND IN THE MODEL CONSENSUS...AND HAVE REMOVED
MENTIONABLE POPS FROM WEDNESDAY NIGHT. IF THE SLOWER TREND
CONTINUES...THURSDAY MAY END UP DRY AS WELL. WHILE IT IS TOO SOON
TO TELL WITH ANY CERTAINTY...THIS SYSTEM IS APT TO BE STRONG
ENOUGH TO BE A SEVERE WEATHER PRODUCER...ESPECIALLY IF THE FRONT
ARRIVES AT THE RIGHT TIME OF DAY. THE UPPER LEVEL FLOW IS EXPECTED
TO AMPLIFY HEADING INTO THE WEEKEND BEHIND THE WAVE/FRONT AND
SHOULD USHER IN ANOTHER UNSEASONABLY COOL AUGUST AIRMASS AS
TROFFING DIGS ACROSS THE EASTERN UNITED STATES.
BAK
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
427 AM EDT MON AUG 13 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 13/09Z TAF UPDATE /...
ISSUED AT 419 AM EDT MON AUG 13 2012
UPDATE...
NO CHANGES.
PREVIOUS DISCUSSION...
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...NIELD/TDUD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
347 AM EDT MON AUG 13 2012
.UPDATE...
THE SYNOPSIS...NEAR TERM...SHORT TERM AND LONG TERM SECTIONS HAVE
BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE 13/06Z TAFS/...
ISSUED AT 105 AM EDT MON AUG 13 2012
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
112 AM EDT MON AUG 13 2012
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 242 PM EDT SUN AUG 12 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA ON MONDAY
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO
THE AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE
END OF THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE
TEMPERATURES WILL RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 1000 PM EDT SUN AUG 12 2012
MODEL ISENTROPIC DATA ON THE 305K LEVEL SUGGESTS BEST CHANCE OF
LIGHT SHOWERS WILL BE ACROSS NORTHWEST PARTS OF THE FORECAST AREA
OVERNIGHT. SO...BUMPED UP POPS A BIT THERE TO AROUND 40 PERCENT AND
KEEP THE REST OF THE FORECAST AREA ESENTIALLY THE SAME.
OTHERWISE...HAD TO MAKE SOME CHANGES TO TEMPERATURES AND DEW POINTS
THE NEXT COUPLE OF HOURS BASED ON 01Z OBS AND TRENDS.
PREVIOUS DISCUSSION FOLLOWS...
ISENTROPIC LIFT WILL TRY TO GENERATE RAIN ACROSS THE FORECAST AREA
TONIGHT...BUT A DRY LOWER ATMOSPHERE WILL WORK AGAINST THE RAIN.
DEWPOINTS THIS AFTERNOON ARE IN THE 40S ACROSS PARTS OF THE
FORECAST AREA...WITH DEWPOINTS IN THE 50S EXTENDING WEST WELL INTO
ILLINOIS.
ANY RAIN THAT HAS TRIED TO MAKE IT EAST TOWARD THE FORECAST AREA
THIS AFTERNOON HAS DRIED OUT THANKS TO THE DRY ATMOSPHERE IN
PLACE. THIS TREND WILL CONTINUE THROUGH THE EVENING...SO HAVE LEFT
THE EVENING DRY. OVERNIGHT...MOISTURE IMPROVES AND FORCING GETS
BETTER ACROSS THE WESTERN HALF OF THE FORECAST AREA...BUT NOTHING
IS IMPRESSIVE.
THUS WILL ONLY GO LOW POPS ACROSS THE WESTERN FORECAST AREA
OVERNIGHT...AND WILL TIME FOR MAINLY AFTER 09Z.
WITH INCREASING CLOUDS TONIGHT...A BLEND OF MODEL TEMPERATURES
LOOKS GOOD FOR LOW TEMPERATURES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
ISSUED AT 242 PM EDT SUN AUG 12 2012
FOCUS IS ON CHANCES FOR RAIN EARLY IN THE PERIOD. FOR THE MOST
PART MODELS ARE IN DECENT AGREEMENT. GFS IS FARTHER NORTH THAN THE
OTHER MODELS WITH THE SURFACE LOW ON MONDAY...BUT SREF MEAN IS
ALSO FARTHER NORTH. THUS AM NOT GOING TO COMPLETELY DISREGARD THE
GFS...BUT WILL KEEP IT IN THE BLEND.
MODELS ARE NOT QUITE AS BULLISH WITH RAINFALL WITH THE NEXT
SYSTEM. HOWEVER FORCING AHEAD OF THE SURFACE LOW ON MONDAY SHOULD
BE ENOUGH FOR LIKELY POPS MOST AREAS. WITH LESS CONFIDENCE THOUGH
WILL ONLY GO ON LOW END OF LIKELY CATEGORY MONDAY.
THE LOW WILL EXIT THE AREA MONDAY NIGHT. WILL GO HIGHEST POPS
DURING THE EVENING THEN DIMINISH OVERNIGHT AS LOW EXITS THE AREA.
AN UPPER TROUGH REMAINS ACROSS THE AREA ON TUESDAY...BUT MOISTURE
SHOULD BE OUT OF THE AREA BY THEN. AS USUAL GFS OVERDOES MOISTURE
AND THUS GENERATES RAINFALL ON TUESDAY...BUT OTHER MODELS ARE
DRY. WILL THUS KEEP DRY FORECAST.
HIGH PRESSURE WILL THEN KEEP DRY CONDITIONS INTO WEDNESDAY.
MOS ACTUALLY DOES NOT LOOK TOO BAD FOR HIGHS MONDAY GIVEN EXPECTED
CONDITIONS. STUCK WITH A MODEL BLEND FOR LOWS MONDAY NIGHT AND
TUESDAY NIGHT. GIVEN RETURN OF SUNSHINE DURING TUESDAY WENT AT OR
ABOVE MOS FOR HIGHS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
ISSUED AT 205 PM EDT SUN AUG 12 2012
GFS AND ECMWF CONTINUE A PERSISTENT NW FLOW ALOFT DURING THIS
FORECAST PERIOD. THE MAIN WX EVENT DURING THE PERIOD WILL BE A
SHORT WAVE THAT WILL APPROACH AND PUSH THROUGH THE AREA ON
WEDNESDAY NIGHT THROUGH FRIDAY...BRINGING CHANCES FOR SHOWERS AND
THUNDERSTORMS. THE UPPER PATTERN CONTINUES TO INDICATE A HIGHLY
AMPLIFIED PATTERN THROUGH NEXT WEEKEND WITH STRONG RIDGING
BUILDING ACROSS THE WESTERN UNITED STATES AND COOL NORTHWEST FLOW
SPILLING INTO THE OHIO VALLEY FROM CENTRAL CANADA. THUS OTHER THAN
THE PREVIOUSLY MENTIONED PASSING SHORT WAVE...DRY AND COOLER
WEATHER WILL BE EXPECTED WITH HIGH TEMPERATURES AT OR BELOW
SEASONAL NORMALS.
&&
.AVIATION /DISCUSSION FOR THE 13/06Z TAFS/...
ISSUED AT 105 AM EDT MON AUG 13 2012
VFR THROUGH THE PERIOD.
MIDLEVEL OVERCAST ASSOCIATED WITH APPROACHING DISTURBANCE WILL
CONTINUE TO OVERSPREAD THE SITES DURING THE PERIOD. AN AREA OF
ECHOES ON REGIONAL RADAR MOSAIC...INCLUDING SOME THUNDERSTORMS...ARE
UNLIKELY TO SURVIVE INTO THE AREA IN THEIR CURRENT FORM PER HRRR AND
SREF PROBABILITIES. WILL MAINTAIN VCTS MENTION FOR TOMORROW FROM
PREVIOUS TAFS AS SURFACE AND UPPER LOW APPROACH.
WINDS WILL BE LIGHT AND VARIABLE EARLY...BECOMING SOUTHERLY IN THE
MORNING...GENERALLY REMAINING 10KT OR BELOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50/MK
SHORT TERM...50
LONG TERM....PUMA
AVIATION...NIELD
AREA FORECAST DISCUSSION
NWS WICHITA KS
1151 PM CDT SUN AUG 12 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
MVFR CIGS CURRENTLY OVER NEBRASKA AND IOWA WILL FILTER SOUTH
TONIGHT...APPROACHING KSLN BY 10-12Z AND KCNU BY 12-14Z...AND
PERSISTING THROUGH A GOOD PORTION OF THE MORNING. CIGS HAVE THE
POTENTIAL TO GO BELOW 2000 FT AGL...BUT ONLY WENT BKN025 FOR NOW.
WESTERN EDGE OF CIGS MAY FLIRT WITH KHUT-KICT...BUT LEFT OUT OF
THOSE TAFS FOR NOW. OTHERWISE...LOW CIGS WILL DISSIPATE FAIRLY
QUICKLY WITH DAYTIME HEATING ALTHOUGH THEY COULD HANG INTO THE
EARLY AFTERNOON AT KCNU. MODEST/GUSTY NORTH WINDS WILL PREVAIL
FOR MOST SITES MONDAY.
KLEINSASSER
&&
.PREV DISCUSSION... /ISSUED 749 PM CDT SUN AUG 12 2012/
UPDATE...
STILL A SMALL OPPORTUNITY FOR A FEW THUNDERSTORMS OVER EXTREME
SOUTHEAST KANSAS THROUGH ABOUT 10 PM...AS THE COLD FRONT CONTINUES
TO SLOWLY MOVE SOUTHEAST. POOR LAPSE RATES PER 00Z SPRINGFIELD
SOUNDING AND ONLY MODEST LOW-LEVEL MOISTURE IS PREVENTING OFF THE
CHARTS INSTABILITY...ALTHOUGH 40 KTS OF DEEP LAYER SHEAR WOULD
SUPPORT STRONG TO MARGINALLY SEVERE WIND/HAIL WITH ANY ACTIVITY
THAT CAN DEVELOP. THREAT SHOULD END BY 10 PM.
KLEINSASSER
PREV DISCUSSION... /ISSUED 636 PM CDT SUN AUG 12 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
NARROW WINDOW FOR A STRAY THUNDERSTORM AT KCNU WILL END BY 01-02Z
THIS EVENING...ALONG A COLD FRONT SHIFTING SOUTHEAST ACROSS THE
REGION. DUE TO LOW PROBABILITIES...DID NOT INCLUDE VCTS IN KCNU
TAF. OTHERWISE...MODEST NORTH WINDS WILL CONTINUE TONIGHT. BY
11-13Z EARLY MONDAY MORNING...ANTICIPATING MVFR CIGS TO FILTER
SOUTH ACROSS EASTERN KS...AFFECTING PRIMARILY KCNU ALTHOUGH
WESTERN EDGE COULD CLIP KICT-KSLN. CIGS SHOULD RISE ABOVE MVFR BY
LATE MORNING/EARLY AFTERNOON...WITH MODESTLY GUSTY NORTH WINDS
ANTICIPATED AGAIN MONDAY MORNING THROUGH AFTERNOON.
KLEINSASSER
PREV DISCUSSION... /ISSUED 351 PM CDT SUN AUG 12 2012/
DISCUSSION...
SHORT RANGE...TONIGHT THROUGH TUESDAY
IN THE VERY SHORT TERM...SMALL CU BEGINNING TO DEVELOP ACROSS EXTREME
EASTERN KANSAS DUE TO DIURNAL MIXING AND WEAK ISENTROPIC LIFT...WITH
ADDITIONAL COLD CORE CU MOVING INTO NORTHEAST KANSAS. RIGHT
NOW...CU DEVELOPMENT IS NOT OVERLY IMPRESSIVE...HOWEVER SPC MESO
GRAPHICS INDICATED UNCAPPED ENVIRONMENT ACROSS SOUTHEAST KANSAS
AHEAD OF FRONTAL BOUNDARY CURRENTLY BISECTING CWA. HRRR AND RUC
BOTH GIVING INFINITESIMAL CHANCE OF THUNDERSTORMS BRUSHING EXTREME
SOUTHEASTERN CWA BETWEEN 21/12 AND 01/13...THUS WILL MAINTAIN LOW
CHANCE PO0PS IN THIS AREA. THE REST OF THE CWA WILL REMAIN DRY
OVERNIGHT.
NEXT CHANCE OF PRECIPITATION COMES LATE MONDAY NIGHT INTO TUESDAY
AS MCS ROLLS OFF LEE SLOPE OF ROCKIES. MITIGATING FACTOR FOR
COVERAGE WILL BE LOW LEVEL MOISTURE AS FRONT CURRENTLY MOVING
THROUGH PLAINS WILL SCOUR MOISTURE. ISENTROPIC LIFT/MOIST ADVECTION
IMPROVES BETWEEN 06 AND 12 UTC ON TUESDAY...SO WILL TREND POPS UP IN
THIS TIME PERIOD. DISCREPANCY AS WELL ON EXACT TRACK AND SOUTHERN
DEVELOPMENT OF STORMS BETWEEN SHORT TERM MODELS AND ENSEMBLES...WILL
LEAN TOWARD EC SOLUTION WHICH KEEPS BULK OF PRECIP IN CLOSE
PROXIMITY TO BETTER QG AND ISENTROPIC FORCING. MCS THAT ROLLS
THROUGH APPEARS TO LEAVE BOUNDARIES AROUND THAT WILL ALLOW
ADDITIONAL DEVELOPMENT TUES AFTERNOON EVENING AS RRQ OF UPPER LEVEL
JET DIVES FROM CENTRAL PLAINS INTO LOWER MISSISSIPPI VALLEY.
OVERALL...TRENDED LOWER ON QPF AS WELL GIVEN DROUGHT TRENDS.
TEMPERATURES WILL BE PLEASANT...WITH NARY A 100 DEGREE IN SITE FOR
SOME TIME. LARGE SCALE TROUGH ACROSS EASTERN TWO THIRDS OF NATION
WILL KEEP HEAT AT BAY FOR A WHILE. NORTH TO NORTHEAST FLOW MONDAY
WILL KEEP TEMPERATURES BELOW NORMAL FOR THE FIRST TIME IN A LONG
TIME. THAT TREND CONTINUES THROUGH THE SHORT TERM...AS CLOUDS AND
CONVECTION WILL KEEP THINGS A LITTLE COOLER ON TUESDAY AS WELL.
DRYNESS OF SOIL WILL ALLOW FOR SUPERADIABATIC HEATING...SO WILL
TREND TOWARD HIGHER END OF GUIDANCE FOR THE MOST PART.
MEDIUM RANGE...WEDNESDAY THROUGH SATURDAY
ANOTHER ROUND OF SHOWERS AND STORMS POSSIBLE WEDNESDAY NIGHT INTO
THURSDAY AS POTENT SHORT WAVE MOVING THROUGH NORTHERN STREAM DRIVES
ANOTHER FRONTAL SYSTEM THROUGH CWA. MOISTURE AGAIN WILL BE
LIMITED...SO LITTLE SUSPECT OF GREATER POPS PROBABILITIES BEING
GENERATED BY GEFS AND CONSENSUS BLENDS. GIVEN RECENT DROUGHT
TRENDS...TONED PROBABILITIES BACK A LITTLE. AFTER
THURSDAY...SURFACE RIDGING WILL BE IN PLACE THROUGH THE EARLY
WEEKEND...THEN UPPER RIDGING BEGINS TO BUILD BACK INTO CENTRAL
PLAINS AS EASTERN U.S. LARGE SCALE TROUGH EDGES EAST. THERE IS AN
OUTSIDE CHANCE OF CONVECTION RETURNING LATE IN THE WEEKEND DUE TO
ENHANCED RETURNED FLOW...BUT WILL LEAVE FORECAST DRY FOR NOW.
TEMPERATURES RETURN TO NORMAL ON WEDNESDAY HEAD OF AFOREMENTIONED
FRONTAL BOUNDARY...THEN ANOTHER SEVERAL DAYS OF BELOW NORMAL
TEMPERATURES IN STORE FOR THE CWA IN TERMS OF MAXIMUMS AND
MINIMUMS. USED A BLEND OF CONSENSUS FOR HIGHS AND GFS40 FOR
MINS...WHICH HAS BEEN DOING AMAZINGLY WELL GIVEN HOW POORLY IT HAS
HANDLED MAX TEMPERATURES OF LATE.
SF
PREV DISCUSSION... /ISSUED 1222 PM CDT SUN AUG 12 2012/
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
ISOLATED CONVECTION IS EXPECTED ALONG A COLD FRONT LATE THIS
AFTERNOON...WITH A FEW STORMS POSSIBLY AFFECTING SOUTHEAST KANSAS.
FRONTAL TIMING SUGGESTS THIS ACTIVITY WILL BE JUST SOUTH OF KCNU
THOUGH INCLUDED A VCTS FOR A FEW HOURS AT START OF FORECAST.
OTHERWISE GUSTY NORTH-NORTHWEST WINDS BEHIND THE FRONT WILL
DIMINISH THIS EVENING...ONLY TO PICK UP AGAIN AFTER SUNRISE ON
MONDAY MORNING ACROSS THE AREA.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 62 90 62 87 / 0 0 20 30
HUTCHINSON 60 87 62 88 / 0 0 20 30
NEWTON 60 86 60 88 / 0 0 20 30
ELDORADO 61 89 58 88 / 0 0 10 30
WINFIELD-KWLD 64 91 62 88 / 0 0 10 30
RUSSELL 57 87 60 88 / 0 0 30 30
GREAT BEND 58 87 61 88 / 0 0 30 30
SALINA 59 87 61 89 / 0 0 20 30
MCPHERSON 59 87 62 88 / 0 0 20 30
COFFEYVILLE 64 93 60 88 / 0 0 0 30
CHANUTE 62 89 58 88 / 0 0 0 30
IOLA 62 88 58 87 / 0 10 0 30
PARSONS-KPPF 64 90 60 88 / 0 0 0 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
259 AM CDT MON AUG 13 2012
.DISCUSSION...
SHORT TERM CONCERNS DEAL WITH WEAK FRONTAL BOUNDARY ACROSS
NORTHERN MN...MOVING SE ACROSS THE FA DURING THE LATE MORNING/AFTN
TIME FRAME WHICH MAY GENERATE AN ISOLATED SHRA/TSRA IN THE FAR
EASTERN 1/4 OF THE FA. OTHER CONCERNS DEAL WITH TEMPS WED
AFTN...AND ONSET OF PRECIPITATION WED/WED NIGHT.
A BROKEN LINE OF SHRA/TSRA WAS OCCURRING IN NE MN PRIOR TO 3 AM.
THIS BROKEN LINE WAS ASSOCIATED WITH A MID-LEVEL SHRTWV ACROSS
SOUTH CENTRAL CANADA...ENHANCED BY A 25H JET STREAK ACROSS ND.
AMPLE MOISTURE AT MID LEVELS AND WEAK INSTABILITY DURING THE
AFTN...SHOULD BE ENOUGH TO GENERATE SCATTERED SHRA/TSRA FOR MAINLY
WC WI...BUT COVERAGE SHOULD BE LESS THAN 30%.
THE NEXT SYSTEM THAT WILL AFFECT THE UPPER MIDWEST WAS ACROSS THE
GULF OF ALASKA EARLY THIS MORNING...WHICH WILL TRANSLATE E/SE
ACROSS WESTERN CANADA...AND INTO THE NORTHERN ROCKIES BY TUESDAY.
TIMING OF THE FRONTAL PASSAGE WITH THIS SYSTEM HAS BEEN FAIRLY
CONSISTENT FOR WEDNESDAY AFTN/EVENING. THERE STILL REMAINS SOME
UNCERTAINTY WITH THE WAA REGIME DEVELOPING TUESDAY NIGHT/WED
AHEAD OF THE MAIN UPPER SUPPORT. THE LLJ IS NOT CONDUCIVE FOR OUR
REGION TO DEVELOP NOCTURNAL CONVECTION ALONG THE LEADING EDGE OF
THE MUCH WARMER AIR...AND WITH THE MAIN FORCING NORTH OF THE FA.
HOWEVER...THE UNCERTAINTY OF WHERE THIS LLJ DEVELOPS AT LEAST
WARRANTS SLIGHT CHC/S...OR UNTIL WED AFTN/EVENING WHEN THE MAIN
UPPER JET AND THE FRONTAL BOUNDARY MOVES ACROSS THE AREA. HIGHS ON
WED WILL BE DIFFICULT. THERE COULD BE SOME AREAS IN THE SW FA
WHICH READINGS REACH THE 90S...WITH 70S IN THE N FA DUE TO BETTER
CHC/S OF PRECIPITATION AND DENSER CLOUD COVER. WILL LEAN TOWARD
HIGHER TEMPS IN THE SOUTH...BUT THESE COULD BE CONSERVATIVE IF THE
FRONT SLOWS...AND LESS CLOUD COVER EXISTS.
AS WITH PREVIOUS FORECAST...THIS FRONT IS FAIRLY STRONG WHICH WILL
LEAD TO SVR WX CONCERNS WED. WILL HIGHLIGHT MORNING HWO BASED ON
THIS SCENARIO AND SEE WHAT SPC HIGHLIGHTS.
BEHIND THIS SYSTEM...TEMPS FALL TO WELL BELOW MID AUGUST READINGS.
SOME OF THE NORMALIZED ANOMALIES /GEFS/ OF 92/85/70H TEMPS ARE
RUNNING 1-2 STANDARD DEVIATIONS BELOW NORMAL ACROSS THE UPPER
MIDWEST THRU MOST OF THE PERIOD PAST WED. IN SOME PARTS OF THE
PLAINS...THESE ANOMALIES ARE 2-3 STANDARD DEVIATIONS BELOW NORMAL
FOR MID AUGUST. BASICALLY...OUR ABNORMAL WARM TEMPS WE HAVE BEEN
EXPERIENCING WILL END. WITH AT LEAST A PERIOD OF BELOW NORMAL
TEMPS THRU NEXT WEEK...AFT THE FRONTAL PASSAGE WED. LITTLE IN THE
WAY OF PRECIPITATION IS EXPECTED AS THE MAIN STORM SYSTEMS MOVE
SOUTH OF THE REGION. ..JLT..
&&
.AVIATION.../06Z TAF ISSUANCE/
LOW CIGS AND PRECIP NOW EXITING SRN MN AND ALL TERMINALS ARE NOW
DONE WITH THAT SYSTEM WITH A WORRISOME CLEARING /FROM THE FOG
POTENTIAL PERSPECTIVE/ QUICKLY WORKING SE OUT OF WRN MN. AT 330Z...A
COLD FRONT STRETCHED FROM NEAR GRAND FORKS UP TOWARD LAKE OF THE
WOODS AND WAS MOVING SOUTH AT ONLY ABOUT 10-15 KTS. MID LEVEL
CLOUDS ASSOCIATED WITH THE FRONT WILL CERTAINLY COMPLICATE THE FOG
SITUATION THIS EVENING. AS FOR THE FOG...MOST SITES IN WRN MN HAVE
A DEWP DEPRESSION LESS THAN 5 DEGS...AND WITH RWF PICKING UP OVER
AN INCH OF RAIN OVER THE LAST 24 HOURS...FOG IS CERTAINLY A CONCERN
NOW THAT SKIES HAVE CLEARED OUT. HRRR HAS BEEN PAINTING DENSE FOG
ACROSS SW MN AS WELL FOR SEVERAL RUNS NOW...SO DID INCREASE FG
MENTION AT RWF...COULD CERTAINLY HAVE A FEW HOURS OF DENSE FOG
THERE INTO THE MORNING. ACROSS CENTRAL MN...CLOUDS COMING DOWN
WITH THE FRONT WILL COMPLICATE THE FOG SITUATION...BUT IF STC CAN
SPEND A COUPLE OF HOURS CLOUD FREE...THEY COULD EASILY GO DOWN TO
1/2SM OR LESS BEFORE FRONTAL CLOUDS SHOW UP. AS FOR
WINDS...FOLLOWED MORE OF A MET/HRRR IDEA FOR DIRECTIONS WITH THE
SLOWER FROPA GIVEN SPEED WITH WHICH FRONT IS CURRENTLY MOVING. FOR
MONDAY...CU RULE QUITE NEGATIVE BY LATE MORNING ON THE NAM...AND
EXPECT CU TO COME IN RATHER QUICKLY IN THE MORNING AND FADE DURING
THE AFTERNOON AS PROGRESSIVELY DRIER AIR WORKS IN.
KMSP...SLOWED THE ARRIVAL OF NW WINDS A BIT FROM THE GOING TAF AND
IT MAY NOT BE UNTIL CLOSER TO 15Z THAT THE FIELD TURNS OVER TO A
300 DIRECTION. WILL LIKELY CLEAR MID CLOUDS OUT FOR A BIT THIS
EVENING BEFORE FRONTAL CLOUD BAND MOVES IN...WHICH COULD ALLOW FOR
SOME VALLEY FOR THAT COULD IMPACT PARTS OF THE FIELD CLOSEST TO
THE MN RIVER VALLEY. FOR WINDS...NAM/RUC SHOWING SOME 20 KT WINDS
WITHIN 3K FT OF THE SFC IN THE MORNING...SO MAY SEE A FEW GUSTS UP
OVER 15 KTS THROUGH 20Z...BEFORE HIGH PRESSURE MOVING IN FROM THE
DAKOTAS BEGINS TO CUT BACK ON WIND SPEEDS.
OUTLOOK...
.TUESDAY...VFR. TSRA POSSIBLE LATE TUE NIGHT. VARIABLE WINDS 5 KTS.
.WEDNESDAY...CHANCE TSRA DURING THE DAY...TSRA LIKELY AT NIGHT. S
WINDS 10-20 KTS.
.THURSDAY...SHRA AND ISOLD TSRA ENDING EARLY. NW WINDS 10-20 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JLT/MPG
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
419 AM EDT MON AUG 13 2012
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL SLOWLY TRACK EAST
ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY THROUGH TUESDAY. HIGH
PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS AND THEIR ASSOCIATED STRENGTH AND TIMING. HOWEVER...THERE
WILL BE SOME POTENTIAL PITFALLS IN THE NEAR TERM FORECAST.
SURFACE ANALYSIS DEPICTED AN AREA OF WEAK LOW PRESSURE OVER NE
MISSOURI THIS MORNING. MOSAIC RADAR TO OUR WEST WAS SHOWING A
SIZABLE AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS EXTENDING FROM
NW INDIANA SW ACRS MUCH OF ILLINOIS THEN INTO MISSOURI. THE SHOWERS
ACROSS THE NORTHERN SECTIONS OF ILLINOIS AND INDIANA APPEAR TO BE
THE RESULT OF MID LVL ISENTROPIC LIFT OCCURRING IN THE 8 TO 12 K FT
RANGE. FARTHER SOUTH...SHOWERS AND EMBEDDED THUNDERSTORMS WERE
BEING AIDED BY A 925-850 MB LOW LEVEL JET. IT APPEARS THAT THE
SHOWERS ACRS NRN ILLINOIS AND NW INDIANA WILL PUSH EAST THIS
MORNING AWAY FROM ITS ISENTROPIC SOURCE REGION TOWARD OUR NW
FORECAST AREA. IT IS STILL UNCLEAR AT THIS POINT HOW LONG THESE
SHOWERS WILL STAY IN TACT AS THEY CONTINUE TO MOVE EAST AWAY FROM
THEIR SOURCE REGION. HAVE WENT AHEAD AND GONE WITH LIKELY POPS ACRS
OUR NW ZONES AS THE LATEST HRRR MODEL INDICATES THAT THE SHOWERS
SHOULD AT LEAST MAKE IT HERE BEFORE THEY WEAKEN FURTHER TOWARD THE
AFTERNOON HOURS. FARTHER SOUTH...IT BECOMES TRICKY CONSIDERING
AFOREMENTIONED LOW LEVEL JET WILL WEAKEN SOME TOWARD MORNING. HAVE
PLACED CHANCES POPS HERE AND WILL MONITOR RADAR TRENDS AND HRRR
TRENDS SHOULD HIGHER POPS BE NEEDED. IT APPEARS THAT ALL PCPN
SHOULD BE IN THE FORM OF SHOWERS THROUGH EARLY AFTN AS HIGHER
INSTABILITY IS EXPECTED TO REMAIN TO OUR WEST.
THEREAFTER...MID LVL S/WV WILL CONTINUE TO DIG SE ACRS THE WESTERN
GREAT LAKES THROUGH THE REMAINDER OF THE DAY AS SFC LOW PRESSURE
MOVES TOWARD THE ENE TO SRN INDIANA BY THIS EVENING. THERE SHOULD
BE A RELATIVE LULL IN THE PCPN ACTIVITY THIS AFTERNOON BEFORE
HIGHER CHANCES OF SHOWERS/STORMS ARRIVE TONIGHT.
TEMPERATURES WILL BE HARD TO PIN DOWN GIVEN THE TIMING OF PCPN
AND THE AMOUNT OF CLOUD COVER THAT WILL OCCUR FROM TIME TO TIME
TODAY. HAVE TAKEN A BLEND OF ALL AVAILABLE OPERATIONAL MODELS
WHICH YIELD HIGHS FROM THE UPPER 70S NORTHWEST TO THE MID 80S
ALONG AND SOUTH OF THE OHIO RIVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MID LVL S/WV WILL CONTINUE EAST ACRS OUR AREA OVERNIGHT AS SFC LOW
PRESSURE AND WEAK COLD FRONT MOVE EAST AS WELL. THERE IS ENOUGH
EVIDENCE BY THE MODELS TO GO AHEAD AND RAMP POPS UP INTO THE
LIKELY CATEGORY FOR ALL LOCATIONS AS THERE SHOULD BE ENOUGH LOW
LEVEL CONVERGENCE PER A LOW LEVEL JET AND UPR LVL SUPPORT.
ON TUESDAY...LOW PRESSURE WILL SLOWLY MOVE OFF TO THE NE. ITS
ASSOCIATED WEAK COLD FRONT WILL MEANDER SLOWLY EAST AS WELL.
LIKELY POPS ARE EXPECTED EARLY ON ACRS OUR ERN ZONES...THEN POPS
WILL SLOWLY DECREASE THROUGH THE DAY AS DRIER AIR SLOWLY
INFILTRATES FROM THE WEST.
WEAKENING FRONTAL BOUNDARY IS EXPECTED TO BE EAST OF THE AREA BY
WEDNESDAY NIGHT AS WEAK SFC HIGH PRESSURE BUILDS IN FROM THE WEST.
SKIES WILL GRADUALLY CLEAR.
HIGH PRESSURE WILL SETTLE ACROSS THE OHIO VALLEY ON WEDNESDAY.
MOSTLY SUNNY SKIES ARE EXPECTED WITH SLIGHTLY BELOW NORMAL
TEMPERATURES FOR MID AUGUST. THE HIGH WILL BEGIN TO MOVE EAST OF
THE AREA WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS THE HIGH CONTINUES OFF TO THE EAST ON THURSDAY...WE WILL GET
INTO A RETURN FLOW... RESULTING IN THE WARMEST DAY OF THE WEEK
WITH HIGHS INTO THE UPPER 80S TO THE LOWER 90S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANCE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH
DAYS GENERALLY IN THE LOWER 70S.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
ALTHOUGH A FEW SPRINKLES OR LIGHT SHOWERS ARE POSSIBLE BETWEEN 06Z
AND 08Z (MAINLY AT THE WESTERN TAF SITES)...THE FIRST 8 HOURS OF
THE FORECAST PERIOD APPEAR TO BE RELATIVELY TRANQUIL. MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE OVERNIGHT AND INTO
MONDAY...AND HIGH-RESOLUTION COMPUTER GUIDANCE IS INDICATING THAT
RAIN SHOWERS WILL BE POSSIBLE BY EARLY AFTERNOON FOR THE WESTERN
TAF SITES (AND SLIGHTLY LATER FOR THE COLUMBUS SITES). THIS
ACTIVITY WILL GENERALLY BE DISORGANIZED AND IN THE VFR
CATEGORY...BUT BY LATE AFTERNOON THE DIURNAL CYCLE MAY LEAD TO
SOME HEAVIER SHOWERS. WITH INSTABILITY APPEARING MARGINAL...HAVE
LIMITED THE MENTION OF VCTS TO JUST THE CINCINNATI TAF SITES.
SOME SHOWERS MAY PERSIST INTO MONDAY NIGHT...AS WINDS SHIFT FROM
THE SOUTH TO WEST LATE IN THE FORECAST PERIOD.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
136 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL BEGIN TO SLIDE EAST OF OUR AREA LATE TONIGHT AS
LOW PRESSURE MOVES EASTWARD ACROSS THE NORTHERN PLAINS. THE LOW
WILL TRACK TOWARD THE LOWER GREAT LAKES ON MONDAY NIGHT BRINGING A
COLD FRONT AND CHANCES FOR SHOWERS AND THUNDERSTORMS TO OUR AREA.
HIGH PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE
MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
SFC HIGH PRESSURE WILL SLIDE OFF TO THE EAST AS LOW PRESSURE
DEVELOPS INTO THE MID MS VLY IN RESPONSE TO DIGGING UPR SYSTEM
OVERNIGHT. WEAK ISENTROPIC LIFT AHD OF THIS SYSTEM HAS LED TO
VERY LIGHT RAIN SHOWERS/SPRINKLES. RADAR SHOWS THESE LIGHT
SHOWERS/SPRINKLES MOVING ACRS INDIANA AND WEAKENING. EXPECT
THIS TREND TO CONTINUE AS THE SHOWERS MOVE INTO A LESS FAVORABLE
ENVIRONMENT WITH DRIER AIR IN PLACE.
HAVE ALLOWED FOR AN INCREASE IN MID LEVEL CLOUD COVER. THESE
CONDITIONS WILL RESULT IN MOSTLY CLOUDY SKY CONDITIONS. MORE BREAKS
WILL BE PSBL IN THE SW AS INITIAL S/W PASSES BY LATE TONIGHT.
CONTINUING TO FOLLOW LATEST HRRR RUNS...HAVE ALLOWED FOR SPRINKLES
TO WORK ACRS ILN/S FA OVERNIGHT.
HAVE FCST LOWS RANGING FROM THE LOW TO MID 50S FAR EAST TO THE
LOW TO MID 60S WEST.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM TUESDAY/...
THE LOW WILL CROSS ILLINOIS AND INDIANA DURING THE DAY MONDAY.
THIS MEANS OUR AREA WILL BE UNDER SOUTHERLY FLOW WITH PLENTY OF
CLOUD COVER DURING THE DAYTIME. THIS SCENARIO WILL YIELD
TEMPERATURES IN THE LOW TO MIDDLE 80S...SIMILAR TO WHAT IS BEING
EXPERIENCED UPSTREAM OVER EASTERN ILLINOIS TODAY.
MODELS DIFFER SOMEWHAT ON THE TRACK OF THE SURFACE LOW MONDAY
NIGHT. THE NAM/CMC REGIONAL/ECMWF TRACK THE LOW ACROSS OUR FORECAST
AREA TUESDAY MORNING....WHILE THE SREF AND GFS PIVOT THE LOW
ACROSS LAKE HURON. THE LATTER SOLUTION IS FASTER AND BASED ON
SATELLITE TRENDS THIS APPEARS TO BE THE MOST LIKELY SCENARIO. THIS
WOULD DRAG A COLD FRONT ACROSS OUR AREA TUESDAY MORNING. AHEAD OF
THIS FRONT...DYNAMIC FORCING WILL SUPPORT CONVECTIVE DEVELOPMENT
ACROSS INDIANA LATE MONDAY AFTERNOON WITH THIS CONVECTION SHIFTING
EAST ACROSS OUR AREA OVERNIGHT MONDAY NIGHT. THIS MEANS THE
CONVECTION WILL BE IN A WEAKENING MODE AS IT PUSHES ACROSS OUR
AREA. HOWEVER...WITH SUFFICIENT PRE-FRONTAL FORCING
OCCURRING...SHOWERS AND THUNDERSTORMS WILL LIKELY HOLD TOGETHER AS
THEY CROSS THE FORECAST AREA...WITH A WANING SEVERE WEATHER THREAT
DUE TO THE LOSS OF DAYTIME HEATING. HAVE KEPT SIMILAR POPS TO THE
PREVIOUS FORECAST PACKAGE...WITH CHANCE POPS ACROSS THE SOUTH AND
LIKELY ACROSS THE NORTH...WHERE BETTER FORCING WOULD BE OCCURRING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
QUITE A BIT OF VARIABILITY AMONG THE MODELS IN REGARD TO THE SPEED
AND TRACK OF THE SYSTEM EXITING THE AREA ON TUESDAY. THE 12Z NAM IS
THE SLOWEST AND FARTHEST SOUTH...WITH THE SURFACE LOW JUST TO OUR
SOUTHWEST AT 12Z TUESDAY. MEANWHILE THE 12Z GFS IS FASTER AND MUCH
FARTHER NORTH WITH THE LOW. THE 12Z CMC AND ECMWF ARE MORE IN THE
MIDDLE AND WILL TREND THE FORECAST THAT WAY...SLOWING THE END OF
PCPN A BIT THROUGH THE DAY ON TUESDAY. WILL CONTINUE WITH HIGHS ON
TUESDAY IN THE UPPER 70S TO LOWER 80S...BUT THEY MAY END UP BEING A
LITTLE TRICKY DEPENDING ON THE EXACT PLACEMENT/TIMING OF THE LOW AND
RESULTING CLOUD COVER.
SKIES WILL BECOME MOSTLY CLEAR TUESDAY NIGHT INTO WEDNESDAY AS HIGH
PRESSURE BUILDS IN FROM THE WEST. THIS WILL LEAD TO A BRIEF SHOT OF
WEAK CAA WHICH SHOULD HELP KEEP TEMPERATURES DOWN IN THE LOWER TO
POSSIBLY MID 80S ON WEDNESDAY. AS THE HIGH SLIDES OFF TO THE EAST
THROUGH THE DAY ON THURSDAY...WE WILL GET INTO RETURN FLOW...
RESULTING IN THE WARMEST DAY OF THE WEEK WITH HIGHS INTO THE MID TO
UPPER 80S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH DAYS
GENERALLY IN THE LOWER 70S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
ALTHOUGH A FEW SPRINKLES OR LIGHT SHOWERS ARE POSSIBLE BETWEEN 06Z
AND 08Z (MAINLY AT THE WESTERN TAF SITES)...THE FIRST 8 HOURS OF
THE FORECAST PERIOD APPEAR TO BE RELATIVELY TRANQUIL. MID LEVEL
MOISTURE WILL CONTINUE TO INCREASE OVERNIGHT AND INTO
MONDAY...AND HIGH-RESOLUTION COMPUTER GUIDANCE IS INDICATING THAT
RAIN SHOWERS WILL BE POSSIBLE BY EARLY AFTERNOON FOR THE WESTERN
TAF SITES (AND SLIGHTLY LATER FOR THE COLUMBUS SITES). THIS
ACTIVITY WILL GENERALLY BE DISORGANIZED AND IN THE VFR
CATEGORY...BUT BY LATE AFTERNOON THE DIURNAL CYCLE MAY LEAD TO
SOME HEAVIER SHOWERS. WITH INSTABILITY APPEARING MARGINAL...HAVE
LIMITED THE MENTION OF VCTS TO JUST THE CINCINNATI TAF SITES.
SOME SHOWERS MAY PERSIST INTO MONDAY NIGHT...AS WINDS SHIFT FROM
THE SOUTH TO WEST LATE IN THE FORECAST PERIOD.
.OUTLOOK...THUNDERSTORMS ARE POSSIBLE TUESDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...LATTO
NEAR TERM...AR
SHORT TERM...LATTO
LONG TERM...JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS TULSA OK
1153 PM CDT SUN AUG 12 2012
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
COLD FRONT IS CURRENTLY NEAR A KGMJ-KOKM LINE. SCATTERED
STRONG TO SEVERE THUNDERSTORMS CONTINUE AHEAD OF THE FRONT
ACROSS PORTIONS OF EASTERN OKLAHOMA AND NORTHWEST ARKANSAS...
MAINLY NORTH OF INTERSTATE 40 AND EAST OF US HIGHWAY 69. WILL
GO WITH A TEMPO THUNDER GROUP FOR A COUPLE OF HOURS AT THE
ARKANSAS TAF SITES AS THE COLD FRONT WORKS EAST ACROSS THE AREA.
OTHERWISE...VFR CONDITIONS ARE EXPECTED.
&&
.PREV DISCUSSION... /ISSUED 745 PM CDT SUN AUG 12 2012/
DISCUSSION...
TEXT PRODUCTS WERE UPDATED TO INCLUDE SVR WATCH FOR SE OK. SLOW
MOVING FRONT EXTENDS FROM SE KS DOWN TO THE WEST OF TULSA AND THEN
DOWN INTO SOUTH CENTRAL OK. SEVERE STORMS HAVE ERUPTED OVER SOUTH
CENTRAL OK DOWN WHERE THE BEST INSTABILITY LIES...AND WITH 30KTS
OF 500MB FLOW...THERE IS ENOUGH SHEAR TO FOR SUSTAINED CELLS TO
ROTATE. FAIRLY UNIDIRECTIONAL WNW FLOW ALOFT IS FAVORING SPLITTING
CELLS...AND INDEED A LEFT SPLIT IS MOVING TOWARD PUSHMATAHA COUNTY
AS I TYPE. OTHER CELLS ARE DEVELOPING TO ITS NORTH AS WELL...SO
SOME CELL MERGERS COULD OCCUR AS WELL. VERY LARGE HAIL AND
DAMAGING WINDS WILL BE THE PRIMARY THREATS. WILL CONTINUE TO
MONITOR AREAS TO THE NORTH ALONG THE FRONT...AS THE LATEST RUNS OF
THE HRRR MODEL CONTINUE TO INDICATE SCT DVLPMT THIS EVENING.
LACY
PREV DISCUSSION... /ISSUED 621 PM CDT SUN AUG 12 2012/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
A COLD FRONT IS POISED TO MOVE THROUGH KBVO AND THE TULSA
TAF SITES DURING THE NEXT HOUR OR SO. THE FRONT WILL SLOWLY
WORK THROUGH THE AREA TONIGHT MAKING IT THROUGH FSM AROUND 10Z.
SCATTERED THUNDERSTORMS ARE EXPECTED ALONG AND AHEAD OF THE FRONT
TONIGHT. HAVE GONE WITH TEMPO THUNDER AT KMLC AND VCTS AT THE
ARKANSAS TAF SITES FOR NOW. VFR CONDITIONS ARE EXPECTED ON
MONDAY.
PREV DISCUSSION... /ISSUED 355 PM CDT SUN AUG 12 2012/
DISCUSSION...
A SHORTWAVE CURRENTLY LOCATED OVER THE NORTHERN PLAINS WAS PUSHING
A COLD FRONT THROUGH WESTERN AND CENTRAL OKLAHOMA THIS AFTERNOON.
AHEAD OF THE FRONT...TEMPS HAVE WARMED INTO THE LOW 90S TO AROUND
100 DEGREES WITH BREEZY SOUTHERLY WINDS. THIS FRONT IS EXPECTED TO
ENTER INTO EASTERN OKLAHOMA DURING THE LATE AFTERNOON/EVENING
HOURS AND NORTHWEST ARKANSAS OVERNIGHT. CHANCES FOR SHOWERS AND
THUNDERSTORMS REMAIN PROBABLE ACROSS THE REGION AS THE FRONT
PUSHES THROUGH. TEMPS THIS AFTERNOON ARE WARMING ENOUGH TO DEVELOP
INSTABILITY OVER THE REGION WHICH WILL CREATE THE POTENTIAL FOR
SEVERE THUNDERSTORMS THROUGH THE EVENING HOURS. DAMAGING WINDS AND
LARGE HAIL STILL LOOK TO BE THE MAIN THREATS. WINDS WILL SHIFT OUT
OF THE NORTH-NORTHWEST BEHIND THE FRONTAL PASSAGE...WHICH COULD
CREATE A CONCERN FOR THE FIGHTING OF ANY WILDFIRES. THE COLD FRONT
SHOULD BE NEAR THE RED RIVER VALLEY MONDAY MORNING...WITH MOST OF
THE PRECIP HAVING PUSHED OUT OF THE AREA. WILL LEAVE A SLIGHT
CHANCE POP ACROSS FAR SOUTHEAST OKLAHOMA.
BEHIND THE FRONTAL BOUNDARY...LATEST MODEL SOLUTIONS DEVELOP A MCS
OVER EASTERN COLORADO/WESTERN KANSAS MONDAY NIGHT AND PUSH IT
EAST/SOUTHEASTWARD TUESDAY MORNING. THE LOCATION OF THE MCS
TUESDAY MORNING STILL REMAINS SOME WHAT UNCERTAIN THOUGH ANY
OUTFLOW BOUNDARY COULD PUSH THROUGH THE REGION IF THE MCS STAYS
OVER KANSAS. THUS...WILL CONTINUE CHANCE POPS TUESDAY AND COOLER
TEMP NORTH OF I-40. IF INDICATIONS ARE THAT THE SYSTEM COULD REMAIN
NORTH OF THE REGION...THEN THESE TEMPS WILL NEED TO BE BUMPED BACK
UP.
A PIECE OF ENERGY WITHIN THE NORTHWESTERLY UPPER LEVEL FLOW LOOKS
TO MOVE ACROSS THE SOUTHERN PLAINS TUESDAY AND WEDNESDAY AS WELL
WHICH WILL KEEP POPS IN THE GRIDS THROUGH WEDNESDAY. THE GREATEST
CHANCES FOR SHOWERS AND THUNDERSTORMS CONTINUE TO BE THURSDAY INTO
FRIDAY IN RESPONSE TO A STRONGER COLD FRONT MOVING ACROSS THE
PLAINS. TEMPS BEHIND THIS FRONT SHOULD BE ABLE TO BE BELOW NORMAL
WITH HIGHS IN THE 80S FOR MOST LOCATIONS INTO THE WEEKEND. USED THE
ECMWF FOR DETAILS IN THE EXTENDED PERIODS AS IT CONTINUES TO BE
THE MOST CONSISTENT WITH THIS SYSTEM.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1139 PM CDT SUN AUG 12 2012
.AVIATION...
THIS ROUND OF CONVECTION IS OVER FOR THE TAF SITES. VFR CONDITIONS
EXPECTED THROUGH PERIOD. AHEAD OF THE WEAK FRONT THE WINDS WILL
VARY AROUND FROM SOUTHWEST TO WEST...AND THEN SHIFT TO NORTH
NORTHEAST AFTER SUNRISE IN THE METROPLEX AND NEAR NOON AT WACO.
84
&&
.UPDATE...
EXTENDED WATCH SOUTH INTO MILLS COUNTY AND CANCELED FOR AREAS
NORTH OF CONVECTION INCLUDING METROPLEX. 84
&&
.PREV DISCUSSION... /ISSUED 332 PM CDT SUN AUG 12 2012/
ALTHOUGH THE PRIMARY MODEL GUIDANCE REMAINS IN DISAGREEMENT
REGARDING THE CONVECTIVE POTENTIAL THIS EVENING...SHORT-TERM
MESOSCALE TRENDS ARE SUGGESTING THAT THE WETTER NAM...HI-RES WRF
AND HRRR MODELS ARE ON THE RIGHT TRACK. THE COLD FRONT IS MAKING
STEADY PROGRESS TO THE SOUTH AND AT 3 PM HAS PASSED THROUGH
WICHITA FALLS. HOWEVER OBS AND RADAR INDICATE A REGION OF LOW
LEVEL CONFLUENCE FROM ABILENE TO GRAHAM TO BOWIE. THIS AREA WILL
BE THE FAVORABLE REGION FOR INITIATION...AND CONVECTION LOOKS LIKE
IT WILL INITIATE WELL AHEAD OF THE FRONT. LOCAL OBJECTIVE ANALYSIS
INDICATES AN AXIS OF 1000-2500 J/KG OF CAPE ALONG AND EAST OF A
LINE FROM GAINESVILLE TO MINERAL WELLS TO LAMPASAS...WHILE DEEP
LAYER SHEAR IS NOW RUNNING NEAR 35KT ACROSS MUCH OF THE AREA.
UNLIKE PREVIOUS SUMMERTIME CONVECTIVE EVENTS...IT HAS BEEN A
COUPLE MONTHS SINCE WE HAVE HAD THIS MUCH 0-6KM WIND SHEAR
AVAILABLE. GIVEN THE AVAILABLE INSTABILITY AND SHEAR...BRIEF
SUPERCELLS WILL BE POSSIBLE...BUT THE MOST LIKELY CONVECTIVE MODE
WILL BE LINE SEGMENTS. SURFACE TEMPERATURES ARE 105+ ACROSS THE NW
ZONES AHEAD OF THE FRONT...WHILE DEWPOINTS ARE IN THE MID 50S.
THIS WILL CREATE AN EXTREMELY FAVORABLE ENVIRONMENT FOR
DOWNBURSTS. DAMAGING WINDS WILL BE THE PRIMARY THREAT THIS
EVENING...AND BECAUSE DEEP LAYER SHEAR IS AVAILABLE IT WILL ALSO
ENHANCE THE POTENTIAL FOR LINE SEGMENTS PRODUCING ORGANIZED COLD
POOLS. STRONG OUTFLOW WINDS MAY IMPACT A MUCH WIDER AREA THAN
ACTUAL RAINFALL. WILL ALSO INCLUDE A MENTION OF HAIL IN
HWO..ALTHOUGH HOT TEMPS MAY LIMIT HAIL SIZE. THE SCATTERED
CONVECTION IS EXPECTED TO TRACK NORTHWEST TO SOUTHEAST ACROSS THE
CWA THIS EVENING...AND THE HIGHEST POPS WILL BE PLACED IN A BAND
ACROSS THE CENTRAL CWA.
THE TRUE COLD FRONT WILL LIKELY BE TEMPORARILY HELD UP AS OUTFLOW
FROM CONVECTION OVER OUR AREA RESULTS IN PREDOMINANTLY SOUTHERLY
WINDS ON ITS NORTH SIDE. FRONT PROBABLY WILL NOT REACH THE
METROPLEX UNTIL DAYBREAK AND WILL LIKELY PUSH INTO THE SOUTHERN ZONES
BY AFTERNOON. HIGH TEMPERATURES TOMORROW WILL BE TRICKY...WITH
LOCATIONS ALONG AND SOUTH OF THE FRONT IN THE AFTERNOON BENEFITING
FROM SUBSIDENCE WARMING AND THE TEMPS FORECAST HERE MAY BE TOO
LOW. ON THE OTHER HAND...CURRENT OBSERVATIONS SUGGEST THE FRONT
HAS A STRONG PUSH...AND THEREFORE AM LEANING TOWARD THE GUIDANCE
THAT SHOWS SOME DECENT COLD ADVECTION IN THE LOW LEVELS ACROSS THE
NORTH AND NORTHEAST ZONES. WILL RETAIN A MENTION OF LOW POPS IN
THE SOUTHERN ZONES TOMORROW WHERE THE FRONT SHOULD BECOME ACTIVE
IN THE AFTERNOON HOURS.
NORTHWEST FLOW ALOFT WILL REMAIN IN PLACE THROUGH TUESDAY. MODEL
GUIDANCE IS HAVING SOME TIMING DIFFERENCES WITH RESPECT TO THE
NEXT SHORTWAVE...EITHER AS EARLY AS TUESDAY MORNING AND AS LATE AS
OVERNIGHT TUESDAY. INSTABILITY/SHEAR WILL BE SUFFICIENT FOR A MCS
OR REMNANT MCS OUTFLOW TO AFFECT THE AREA FROM OKLAHOMA DURING
THIS TIME. WILL CONTINUE WITH SLIGHT CHANCE POPS TUESDAY AND TUESDAY
NIGHT. SOUTHERLY WINDS RETURN BY WEDNESDAY AND NORTHWEST FLOW
ALOFT WEAKENS. CONVECTIVE POTENTIAL SHOULD ALSO DIMINISH...WHILE
TEMPS RETURN TO NEAR 100 DEGREES AREA WIDE THROUGH THURSDAY.
IN THE EXTENDED...THE STRONGER COLD FRONT STILL LOOKS ON TRACK.
IT SHOULD ARRIVE FRIDAY MORNING AND GRADUALLY WORK SOUTH THROUGH
THE REGION INTO SATURDAY MORNING. WILL CONTINUE WITH LOW POPS
STARTING THURSDAY NIGHT IN THE NORTH...WITH 30 PERCENT EVERYWHERE
FRIDAY. WILL HAVE POPS GRADUALLY CLEAR OUT FROM NORTH TO SOUTH ON
SATURDAY. THE LINGERING POPS ON SATURDAY ARE FAVORING THE GFS
SOLUTION WHICH IS WEAKER WITH THE FRONT...AND MAKES SENSE GIVEN
THE TIME OF THE YEAR. THE WEAKER THE FRONT...THE LONGER IT WILL
TAKE FOR IT TO CLEAR OUT THE MOISTURE. REGARDLESS...HIGH
TEMPERATURES SHOULD DROP INTO THE LOW 90S THIS WEEKEND DUE TO
EITHER LOWER THICKNESS VALUES AND/OR INCREASED CLOUDS/RAIN.
TR.92
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 77 99 73 98 76 / 10 10 5 10 20
WACO, TX 77 101 72 100 76 / 20 10 10 10 10
PARIS, TX 73 97 66 95 70 / 10 10 5 10 20
DENTON, TX 73 98 67 97 72 / 10 5 5 20 20
MCKINNEY, TX 73 98 67 96 71 / 10 10 5 10 20
DALLAS, TX 78 99 74 98 76 / 10 10 5 10 20
TERRELL, TX 77 99 70 96 73 / 10 10 5 10 20
CORSICANA, TX 76 100 73 98 75 / 20 10 5 10 20
TEMPLE, TX 75 100 72 100 75 / 20 20 10 10 10
MINERAL WELLS, TX 71 100 66 99 71 / 10 5 5 20 20
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1140 PM CDT SUN AUG 12 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
TROUGHING MOVING EAST OVER IOWA AND MINNESOTA AND SURFACE LOW
PRESSURE CENTERED OVER NE KANSAS EARLY THIS AFTERNOON. ARCING BAND
OF PRECIP STRETCHING FROM SOUTHERN MINNESOTA TO WESTERN ILLINOIS HAS
GENERALLY BEEN DECAYING AS IT MOVES INTO DRIER AIR OVER WISCONSIN.
A SECONDARY AND MORE POTENT BAND IS MOVING NE OVER NORTHEAST IOWA
WHILE ANOTHER AREA OF PRECIP EXISTS OVER EASTERN NORTH DAKOTA WITHIN
THE COMMA HEAD OF THE SHORTWAVE AND ALONG A CANADIAN COOL FRONT. AS
THE SHORTWAVE ENERGY MOVES EAST OVER THE STATE...PRECIP CHANCES ARE
THE MAIN FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...SHORTWAVE TROUGH OVER THE NORTHERN PLAINS WILL MOVE EAST
INTO THE STATE OF WISCONSIN TONIGHT. ASSOCIATED ELONGATED SURFACE
LOW WILL ALSO MOVE EAST INTO ILLINOIS. THE LATEST NAM AND ECMWF
SHOW 300K ISENTROPIC ASCENT AND FGEN WILL REMAIN OVER NORTHERN
ILLINOIS AND SOUTHERN WISCONSIN TONIGHT...WHERE THE LOW LEVEL
MOISTURE WILL ALSO BE THE MOST ABUNDANT. PROGGED SOUNDINGS AND
UPSTREAM OBS CONTINUE TO SHOW DRY WEDGES BELOW 700MB WHERE THE
ATMOSPHERE STRUGGLES TO SATURATE BELOW 10KFT. WILL STILL HAVE THE
MID-LEVEL WAVE MOVE OVERHEAD THOUGH...SO SPRINKLES OR LIGHT SHOWERS
CANNOT BE RULED OUT. BUT WILL PLACE THE HIGHEST PROBABILITY OF
SHOWERS OVER CENTRAL AND EAST-CENTRAL WISCONSIN...THOUGH THE
PROBABILITY WILL ONLY BE IN THE LOW CHANCE RANGE. A MOSTLY CLOUDY
NIGHT WITH LOWS IN THE MID 50S TO LOW 60S.
MONDAY...THE SHORTWAVE TROUGH WILL SLOWLY MOVE ACROSS CENTRAL AND
EASTERN WISCONSIN IN THE MORNING AND EASTERN WISCONSIN AND LAKE
MICHIGAN IN THE AFTERNOON. NOT QUITE AS BULLISH IN QPF AS THE SREF
OR THE GFS SINCE THINK THAT LOW LEVEL FORCING WILL RESIDE FARTHER
SOUTH. BUT STILL LOOKS LIKE THE BEST CHANCES OF PRECIP WILL OCCUR
IN THE MORNING WHEN EAST-CENTRAL WISCONSIN WILL BE ON THE NORTHERN
PERIPHERY OF THE DEEPER MOISTURE...AND THE COMMA HEAD OF THE
SHORTWAVE MOVES OVER NORTH-CENTRAL WISCONSIN. SOME INTERACTION WITH
DAYTIME INSTABILITY APPEARS POSSIBLE AS ML CAPES UP TO 400 J/KG WILL
BE POSSIBLE BY MIDDAY. WILL KEEP A CHANCE IN THE AFTERNOON TO
ACCOUNT FOR ANY DIURNAL INSTABILITY ACTIVITY. PLENTY OF CLOUD COVER
WILL KEEP HIGHS IN THE LOW TO MID 70S.
.LONG TERM...MONDAY NIGHT THROUGH NEXT SUNDAY. UPPER TROUGH WILL
EXIT THE AREA MONDAY NIGHT AND SCATTERED SHOWERS WILL END. THEN
MAINLY DRY NORTHWEST UPPER FLOW EXPECTED TUESDAY THROUGH
WEDNESDAY. THERE COULD BE ISOLATED OR WIDELY SCATTERED SHOWERS
TUESDAY AFTERNOON BUT LEFT THEM OUT OF THE FORECAST FOR NOW. A
SIGNIFICANT UPPER TROUGH WILL APPROACH THE REGION WEDNESDAY NIGHT
AND THURSDAY. THERE CONTINUES TO BE TIMING DIFFERENCES BETWEEN THE
MEDIUM RANGE MODELS SO DID NOT GO WITH LIKELY PROBABILITIES OF
PRECIPITATION AS THERE IS UNCERTAINTY AS TO WHICH PERIOD(S) RAIN
WILL FALL. EITHER WAY IT WILL BE MILDER AND A LITTLE MORE HUMID
WEDNESDAY AS WINDS BECOME SOUTH AND MOISTURE INCREASES. THE UPPER
TROUGH REALLY ESTABLISHES ITSELF ACROSS THE GREAT LAKES FRIDAY
THROUGH SUNDAY. WE MAY SEE THE FIRST PERIOD OF COOLER THAN NORMAL
WEATHER THIS SUMMER THAT LASTS MORE THAN A DAY OR TWO. FROST LOOKS
POSSIBLE FRIDAY NIGHT IN NORTHERN WISCONSIN WITH BIG SURFACE HIGH
OVERHEAD AND LOW DEW POINTS. MENTIONED THIS POSSIBILITY IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.AVIATION...A LOW PRESSURE SYSTEM WILL TRACK WELL SOUTH OF THE REGION
LATE TONIGHT INTO MONDAY...TAKING MOST OF THE SHOWER ACTIVITY SOUTH
OF THE FORECAST AREA. SOME LIGHT SHOWER ACTIVITY WILL BRUSH PARTS
OF C/EC WI LATE TONIGHT INTO EARLY MONDAY. AN UPPER LEVEL TROF AND
WEAK SFC COLD FRONT WILL PASS THROUGH THE AREA ON MONDAY...AND
SHOULD BRING SCATTERED SHOWERS TO THE ENTIRE REGION. A FEW TSTMS
ARE POSSIBLE DURING THE AFTERNOON...ESPECIALLY OVER NORTHERN WI...
ALTHOUGH THE PROBABILITY IS TOO LOW TO ADD TO THE RHI TAF AT THIS
TIME. EXPECT SOME CLEARING TO OCCUR BY MONDAY EVG. VFR CONDITIONS
SHOULD PREVAIL THROUGH MOST OF THE TAF PERIOD.
KIECKBUSCH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1043 AM CDT MON AUG 13 2012
.UPDATE...
15Z SURFACE ANALYSIS INDICATES THE COLD FRONT HAS REACHED A LINE
FROM FLIPPIN...TO JUST SOUTH OF MENA. FORECASTS HAVE BEEN ADJUSTED
TO LOWER PRECIPITATION CHANCES THIS AFTERNOON...AS A FAIR AMOUNT
OF CONVECTIVE OVERTURNING HAS OCCURRED AHEAD OF THE BOUNDARY.
55
&&
.PREV DISCUSSION... /ISSUED 626 AM CDT MON AUG 13 2012/
AVIATION...
AREA OF CONVECTION MOVING ACROSS CENTRAL ARKANSAS THIS
MORNING...AS SHORTWAVES MOVES ACROSS THE STATE. THIS AREA OF
CONVECTION WILL MOVE OUT OF THE AREA IN THE NEXT COUPLE OF
HOURS...AND MAY CLIP KPBF THIS MORNING. EXPECT SOME REDEVELOPMENT
ACROSS SOUTHEAST ARKANSAS LATER THIS AFTERNOON AS COLD FRONT MOVES
INTO THE STATE. ACROSS THE NORTH...SKIES HAVE ALREADY
CLEARED...BUT SOME MVFR CIGS COULD DEVELOP LATER ON THIS MORNING.
WILL HAVE TO MONITOR FOR FOG DEVELOPMENT TONIGHT...ESPECIALLY IN
AREAS THAT RECEIVED HEAVY RAIN TODAY.
PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 91 65 86 65 / 30 10 10 10
CAMDEN AR 95 67 91 67 / 50 20 10 20
HARRISON AR 88 63 84 66 / 10 0 10 10
HOT SPRINGS AR 95 67 89 67 / 30 10 20 20
LITTLE ROCK AR 93 67 87 67 / 40 10 10 20
MONTICELLO AR 94 69 89 68 / 50 20 10 10
MOUNT IDA AR 93 65 89 64 / 20 10 20 20
MOUNTAIN HOME AR 89 63 85 63 / 10 0 10 10
NEWPORT AR 91 66 86 65 / 40 10 10 10
PINE BLUFF AR 93 67 88 66 / 50 20 10 10
RUSSELLVILLE AR 91 67 88 66 / 10 10 10 20
SEARCY AR 90 66 86 65 / 40 10 10 10
STUTTGART AR 91 67 87 66 / 50 20 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
626 AM CDT MON AUG 13 2012
.AVIATION...
AREA OF CONVECTION MOVING ACROSS CENTRAL ARKANSAS THIS
MORNING...AS SHORTWAVES MOVES ACROSS THE STATE. THIS AREA OF
CONVECTION WILL MOVE OUT OF THE AREA IN THE NEXT COUPLE OF
HOURS...AND MAY CLIP KPBF THIS MORNING. EXPECT SOME REDEVELOPMENT
ACROSS SOUTHEAST ARKANSAS LATER THIS AFTERNOON AS COLD FRONT MOVES
INTO THE STATE. ACROSS THE NORTH...SKIES HAVE ALREADY
CLEARED...BUT SOME MVFR CIGS COULD DEVELOP LATER ON THIS MORNING.
WILL HAVE TO MONITOR FOR FOG DEVELOPMENT TONIGHT...ESPECIALLY IN
AREAS THAT RECEIVED HEAVY RAIN TODAY.
&&
.PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...58
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
500 AM CDT MON AUG 13 2012
.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
&&
.LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...44 / LONG TERM...58
AREA FORECAST DISCUSSION
NWS TUCSON AZ
645 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.UPDATE...RAN OUT A QUICK UPDATE TO THE FORECAST FOR THE SPOTTY
SHOWERS THAT ARE AROUND THIS MORNING...BUT DID EMPHASIS BETTER
CHANCES IN WESTERN PIMA COUNTY SINCE THE HRRR HAS BEEN HITTING THIS
AREA WITH MORE LIGHT SHOWERS IN THE PAST 3 HOURLY RUNS. THIS MODEL
DID HIT THE EARLY MORNING SPOTTY SHOWERS THAT MOVED THROUGH AREAS
EAST OF TUCSON. TAKING A LOOK AT THE TUCSON SOUNDING...IT IS A BIT
WARMER AT THE SURFACE THAT IS WAS ON SUNDAY...SO 109 OR 110 LOOKS
PRETTY GOOD.
&&
.DISCUSSION...KIND OF AN INTERESTING DAY ON TAP FOR SOUTHEAST
ARIZONA. FIRST THERE IS A BACK DOOR COLD FRONT AND SEVERAL OUTFLOW
BOUNDARIES MOVING THROUGH SOUTHWEST NEW MEXICO WHICH HAS DEVELOPED
ISOLATED THUNDERSTORMS. LATEST HRRR RUNS INDICATE THAT THERE WILL BE
SOME WEAK SHOWERS...POSSIBLY A THUNDERSTORM...ALONG/NEAR THE AZ/NM
BORDER THIS MORNING. BASED ON WHAT IS CURRENTLY OCCURRING IN SE NEW
MEXICO...WILL UP POPS THIS MORNING ALONG/NEAR THE AZ/NM BORDER. FOR
THE REMAINDER OF TODAY...STILL RATHER DRY WITH PW VALUES AROUND ONE
INCH. STORMS FOR THE MOST PART WILL BE NEAR THE HIGHER TERRAIN. IF A
FEW DO MOVE INTO THE VALLEYS...THE COULD BE SEVERE DUE TO A VERY HOT
BOUNDARY LAYER. THE OTHER STORY FOR TODAY WILL BE THE CONTINUE VERY
HOT TEMPERATURES FOR MID AUGUST. HIGHS TODAY WILL BE SIMILAR TO WHAT
OCCURRED SUNDAY WITH HEAT ADVISORY IN EFFECT FOR THE LOWER
ELEVATIONS OF PIMA AND PINAL COUNTIES.
FOR THE REMAINDER OF THE WEEK...WILL SEE A GRADUAL INCREASE IN
MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL STORM HECTOR NO LONGER
WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT DID INCREASE MOISTURE
OVER THE SOUTHERN PARTS OF THE GULF OF CALIFORNIA ON SUNDAY. THE
GULF REMAINS VERY MOIST WITH PW VALUES OVER 1.50". WILL SEE MORE
THUNDERSTORM COMPLEXES DEVELOP OVER SONORA MEXICO...SENDING LOW
LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS SOUTHERN ARIZONA AND
ALSO PUSHING OUTFLOWS INTO THE GULF WITH RESULTANT INCREASE IN LOW
LEVEL MOISTURE INTO THE LOWER DESERTS. DIDN`T MAKE MANY CHANGES TO
THE INHERITED FORECAST AS IT HAD A VERY GOOD HANDLE ON THE TRENDS
FOR THE WEEK. WILL THERE BE DAILY CHANGES. SURE...BUT OVERALL THE
FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA MAINLY FROM KTUS EWD/SWD INTO THIS
EVENING. OTHERWISE...VFR CONDITIONS AND SURFACE WIND GENERALLY LESS
THAN 10 KTS THRU MIDNIGHT OR 14/07Z. AVIATION DISCUSSION NOT UPDATED
FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1133 AM EDT MON AUG 13 2012
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1133 AM EDT MON AUG 13 2012
LOW PRESSURE CONTINUES TO SPIN NEAR ST. LOUIS. THIS LOW WILL SLOWLY
WORK ITS WAY TOWARD THE FORECAST AREA THIS AFTERNOON.
MAIN AREA OF SHOWERS AND THUNDERSTORMS IS SKIRTING THE FAR SOUTHERN
FORECAST AREA THIS MORNING. THIS IS BEING DRIVEN BY A LOW LEVEL JET.
THIS AREA SHOULD CONTINUE TO SLIDE OFF TO THE EAST INTO EARLY
AFTERNOON. OTHER SCATTERED SHOWERS WERE DEVELOPING ACROSS NORTHWEST
INDIANA AND NORTHERN ILLINOIS IN ISENTROPIC LIFT AHEAD OF THE LOW.
WITH THE BULK OF THE RAIN REMAINING TO THE SOUTH THROUGH MID
AFTERNOON CLOSER TO THE LOW LEVEL JET...HAVE ONLY WENT CHANCE POPS
THROUGH MID AFTERNOON. ISENTROPIC LIFT AHEAD OF THE LOW WILL
CONTINUE TO PRODUCE SCATTERED SHOWERS...AND PERHAPS A THUNDERSTORM.
DID KEEP LIKELY POPS LATE THIS AFTERNOON ACROSS THE WEST AS MODELS
CONTINUE TO HINT AT SOME CONVECTIVE DEVELOPMENT AHEAD OF THE LOW.
LOWERED TEMPERATURES A LITTLE THIS AFTERNOON DUE TO CLOUD
COVER...BUT SATELLITE DOES SHOW SOME BREAKS IN THE CLOUDS AHEAD OF
THE LOW. TEMPERATURES SHOULD REBOUND WELL IN THE AREAS OF
SUNSHINE...SO DIDN/T CUT TEMPERATURES TOO MUCH.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE IND 131500Z TAF UPDATE/...
VFR CONDITIONS EXPECTED TO CONTINUE THIS AFTERNOON.
RADAR TRENDS SHOW PRECIP SHIELD STRETCHING EAST OF INDIANAPOLIS
SOUTHWEST TOWARD EVANSVILLE. THE PRECIPITATION WAS SLOWLY SLIDING
EAST...HOWEVER ISOLATED SHRA WERE POPPING UP IN WESTERN INDIANA IN
THE WAKE. BEST FORCING WILL CONTINUE TO DRIFT EAST THIS
AFTERNOON...ENDING THE WIDESPREAD RAIN CHCS. HOWEVER HRRR SUGGEST
CONVECTION DEVELOPING IN WESTERN INDIANA THIS AFTERNOON AND
SPREADING ACROSS CENTRAL INDIANA INCLUDING THE IND AREA. THUS WILL
INCLUDE SOME VCTS LATER THIS AFTERNOON AND EVENING DURING MAX
HEATING HOURS.
/DISCUSSION FOR THE 13/12Z TAF ISSUANCE/...
ISSUED AT 717 AM EDT MON AUG 13 2012
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL COVER ALL TAF SITES FOR
THE MAJORITY OF THE TAF PERIOD. ANTICIPATE MAINLY RAINFALL WITH
SOME EMBEDDED LIGHTNING THROUGH THE COURSE OF THE DAY...SO WILL
ONLY COVER WITH VCTS FOR NOW. IF ANYTHING BECOMES MORE
ORGANIZED...IT WILL HAVE TO BE ADDRESSED WITH FUTURE UPDATES...BUT
BEST CHANCES FOR SEVERE STORMS ARE SOUTH OF TAF SITES. FOR
NOW...EXPECTING VFR CONDITIONS THROUGH THE DURATION OF TAF PERIOD.
HOWEVER...WILL NOT RULE OUT POSSIBLE FOG FORMATION LATE
TONIGHT...ESPECIALLY AT KLAF AND KHUF WHERE THERE COULD BE
CLEARING SOONER THAN AT OTHER TAF SITES. CONFIDENCE IS NOT HIGH
THOUGH BECAUSE WINDS MAY BE A BIT TOO STRONG...AND CURRENT
THINKING IS THAT CLOUDS WILL HANG IN THERE. AS A RESULT...WILL
LEAVE MENTION OUT OF TAFS FOR NOW. WINDS WILL START OUT
SOUTHEASTERLY AND THEN VEER TO THE SOUTH...AND FINALLY WEST BY
TONIGHT. SUSTAINED SPEEDS WILL RANGE FROM 5 TO 10 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...50
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...TDUD/JP
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1030 AM EDT MON AUG 13 2012
.UPDATE...
AVIATION SECTION UPDATED
&&
.SYNOPSIS...
ISSUED AT 337 AM EDT MON AUG 13 2012
AN AREA OF LOW PRESSURE WILL MOVE THROUGH THE AREA TODAY AND TONIGHT
BRINGING SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL MOVE INTO THE
AREA ON THURSDAY...BRINGING ANOTHER CHANCE FOR RAIN FOR THE END OF
THE WEEK. BEHIND THIS COLD FRONT...BELOW AVERAGE TEMPERATURES WILL
RETURN FOR NEXT WEEKEND.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
FORECAST FOCUS IS ON RAIN THIS PERIOD. MODELS ARE IN GENERAL
AGREEMENT...WITH SOME MINOR DIFFERENCES SO WILL USE A BLEND.
NOTED TWO DIFFERENT THINGS WITH THIS MODEL RUN AS COMPARED TO THIS
TIME YESTERDAY. FIRST THIS SYSTEM IS NOT AS PROGRESSIVE AS
ORIGINALLY DEPICTED...INSTEAD TRANSVERSING VERY SLOWLY OVER A 12+
HR PERIOD ACROSS INDIANA. AND SECOND IT IS NOT AS BULLISH WITH THE
QPF AMOUNTS...SURPRISING SOMEWHAT CONSIDERING THE SLOWER TIMING.
SEVERE THREAT APPEARS MINIMAL...HOWEVER CENTRAL INDIANA WILL
LIKELY SEE PERIODS OF HEAVY RAIN AND CHANCES FOR HAIL...AND STRONG
WINDS. BETTER INSTABILITY AND SLIGHT RISK FOR SEVERE WEATHER LIES
JUST TO THE SOUTH OF THE FORECAST AREA. GRAZING ONLY THE FAR SW
COUNTIES OF CWA.
KEPT POPS LIKELY FOR TODAY. TRIED TO SHOW THE TRANSITION OF HIGHER
POPS FROM W TO E GOING INTO THIS EVENING. WENT SLIGHTLY BELOW MOS TO
ACCOUNT FOR CLOUDS/RAIN FOR HIGHS IN THE UPPER 70S TO LOW/MID 80S.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EDT MON AUG 13 2012
AS STATED ABOVE MODELS ARE NOT SO PROGRESSIVE WITH THIS SYSTEM.
HAVE OPTED TO CARRY LIKELY POPS...ESPECIALLY ACROSS THE EASTERN
HALF OF THE CWA WELL INTO THIS EVENING. LAST OF THE PRECIP DOES
NOT LOOK TO EXIT THE FORECAST AREA UNTIL EARLY TUESDAY MORNING.
AN UPPER TROUGH WILL REMAIN ACROSS THE AREA ON TUESDAY HOWEVER
CONDITIONS WILL BE DRY AND SKIES WILL SLOWLY BEGIN TO CLEAR. HIGH
PRESSURE WILL THEN KEEP DRY CONDITIONS THROUGH MID WEEK.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 337 AM EDT MON AUG 13 2012
MODELS MAINTAIN CONSISTENCY IN REGARD TO SYSTEM AT THE BEGINNING OF
THE EXTENDED PERIOD. INITIALIZATION CONTINUES TO PULL IN LIKELY
POPS ON THURSDAY NIGHT AS AN ASSOCIATED COLD FRONT TRACKS ACROSS
CENTRAL INDIANA. SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST
THROUGH FRIDAY AFTERNOON...AND THEN TAPER OFF AS THE SYSTEM EXITS
THE REGION. IN ITS WAKE...A LARGE RIDGE OF HIGH PRESSURE OVER THE
WESTERN U.S. WILL CONTRIBUTE TO DRIER CONDITIONS AND COOLER TEMPS
FOR THE REMAINDER OF THE LONG TERM PERIOD.
&&
.AVIATION /DISCUSSION FOR THE IND 131500Z TAF UPDATE/...
VFR CONDITIONS EXPECTED TO CONTINUE THIS AFTERNOON.
RADAR TRENDS SHOW PRECIP SHIELD STRETCHING EAST OF INDIANAPOLIS
SOUTHWEST TOWARD EVANSVILLE. THE PRECIPITATION WAS SLOWLY SLIDING
EAST...HOWEVER ISOLATED SHRA WERE POPPING UP IN WESTERN INDIANA IN
THE WAKE. BEST FORCING WILL CONTINUE TO DRIFT EAST THIS
AFTERNOON...ENDING THE WIDESPREAD RAIN CHCS. HOWEVER HRRR SUGGEST
CONVECTION DEVELOPING IN WESTERN INDIANA THIS AFTERNOON AND
SPREADING ACROSS CENTRAL INDIANA INCLUDING THE IND AREA. THUS WILL
INCLUDE SOME VCTS LATER THIS AFTERNOON AND EVENING DURING MAX
HEATING HOURS.
/DISCUSSION FOR THE 13/12Z TAF ISSUANCE/...
ISSUED AT 717 AM EDT MON AUG 13 2012
WIDESPREAD SHOWERS AND THUNDERSTORMS WILL COVER ALL TAF SITES FOR
THE MAJORITY OF THE TAF PERIOD. ANTICIPATE MAINLY RAINFALL WITH
SOME EMBEDDED LIGHTNING THROUGH THE COURSE OF THE DAY...SO WILL
ONLY COVER WITH VCTS FOR NOW. IF ANYTHING BECOMES MORE
ORGANIZED...IT WILL HAVE TO BE ADDRESSED WITH FUTURE UPDATES...BUT
BEST CHANCES FOR SEVERE STORMS ARE SOUTH OF TAF SITES. FOR
NOW...EXPECTING VFR CONDITIONS THROUGH THE DURATION OF TAF PERIOD.
HOWEVER...WILL NOT RULE OUT POSSIBLE FOG FORMATION LATE
TONIGHT...ESPECIALLY AT KLAF AND KHUF WHERE THERE COULD BE
CLEARING SOONER THAN AT OTHER TAF SITES. CONFIDENCE IS NOT HIGH
THOUGH BECAUSE WINDS MAY BE A BIT TOO STRONG...AND CURRENT
THINKING IS THAT CLOUDS WILL HANG IN THERE. AS A RESULT...WILL
LEAVE MENTION OUT OF TAFS FOR NOW. WINDS WILL START OUT
SOUTHEASTERLY AND THEN VEER TO THE SOUTH...AND FINALLY WEST BY
TONIGHT. SUSTAINED SPEEDS WILL RANGE FROM 5 TO 10 KTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....TDUD
AVIATION...TDUD/JP
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
642 AM CDT MON AUG 13 2012
.UPDATE...
A NARROW BAND OF FORCING/CONVERGENCE IS HELPING TO MAINTAIN LIGHT
RAIN FROM ROUGHLY KOTM TO SOUTH OF KRFD. BASED ON OVERALL CLOUD
MOVEMENT ACROSS THE DAKOTAS/MINNESOTA SKIES WILL BE SLOW TO CLEAR
DURING THE DAY. SAID CLEARING WILL HAVE AN IMPACT ON MAX TEMPERATURES
TODAY.
SFC OBS INDICATE DZ IS OCCURRING BUT NOT TO THE EXTENT OF A FEW
HOURS AGO. LOW CLOUDS AND CONDENSATION PRESSURE DEFICITS INDICATE
THAT DZ WILL BE POSSIBLE IN AREAS THAT DO NOT HAVE SHRA OR LIGHT
RAIN. RAP TRENDS WITH FCST SOUNDINGS DO SHOW A SLOW DRYING ALOFT
SUGGESTING DZ THROUGH THE MORNING HOURS.
CURRENT PLAN IS TO UPDATE THE FCST TO THE CURRENT TRENDS/THINKING.
THE APPARENT BACK EDGE OF ANY -RA/DZ APPEARS TO BE THE AXIS OF THE
NEXT VORT MAX DROPPING DOWN THROUGH THE SHORTWAVE. IF THE RAP
TRENDS ARE CORRECT...MOST AREAS WEST OF THE MISSISSIPPI SHOULD BE
DRY DURING THE AFTERNOON AS NVA BEHIND THE VORT MAX TAKES OVER.
NON-MEASURABLE PRECIP MAY LINGER INTO THE AFTERNOON EAST OF THE
MISSISSIPPI DUE TO THE WEAKENING VORT MAX. ..08..
&&
.AVIATION...
CONDITIONS RANGE FROM IFR TO VFR BUT WILL SLOWLY IMPROVE VFR
THROUGH 00Z/14. THE LIGHT RAIN/DRIZZLE WILL SLOWLY END FROM WEST
TO EAST AS A STORM SYSTEM NEAR KSTL MOVES INTO THE OHIO VALLEY.
HIGH PRESSURE BUILDING INTO THE AREA AFT 00Z/14 WILL CREATE LIGHT
WINDS. THE LIGHT WINDS AND WET GROUND MAY ALLOW FG TO DVLP AFT
06Z/14 AS HAS HAPPENED IN MINNESOTA. FG POTENTIAL WAS SUGGESTED
WITH THE 12Z TAFS WITH A FEW CLOUDS BLO 1KFT AGL. THE POTENTIAL
DOES EXIST FOR IFR/LIFR CONDITIONS AFT 06Z/14. ..08..
&&
.PREV DISCUSSION... /ISSUED 310 AM CDT MON AUG 13 2012/
SYNOPSIS...
06Z SFC ANALYSIS HAS A LOW NEAR KCOU WITH A WARM FRONT EAST ACROSS
SOUTHERN ILLINOIS. INVERTED TROFS RAN NORTHWEST FROM THE LOW INTO
WESTERN IOWA AND NORTHEAST INTO NORTHERN ILLINOIS. DEW POINTS WERE
IN THE 50S ACROSS MUCH OF THE MIDWEST EXCEPT FOR 60S AROUND THE LOW
AND INVERTED TROFS.
SHORT TERM...TODAY AND TONIGHT...
THE STRENGTHENING SYSTEM IN THE LOWER MISSOURI VALLEY WILL SLOWLY
MOVE INTO THE LOWER OHIO VALLEY BY MID DAY. BASED ON RADAR AND RAP
MODEL TRENDS THE DEFORMATION ZONE ACROSS THE AREA WILL SLOWLY WEAKEN
DURING THE MORNING HOURS. THE BETTER PRECIPITATION SHOULD BE EAST OF
THE MISSISSIPPI DURING THE MORNING WITH MORE SPRINKLES/DRIZZLE/LIGHT
RAIN WEST OF THE MISSISSIPPI. BY LATE MORNING CONDENSATION PRESSURE
DEFICITS BEGIN SLOWLY RISING OVER THE FAR NORTHWEST/WEST PARTS OF
THE CWFA SO RAIN THERE SHOULD END.
DURING THE AFTERNOON...THE OVERALL FORCING CONTINUES TO WEAKEN WITH
CONDENSATION PRESSURE DEFICITS SLOWLY RISING. THUS RAIN WILL DECAY
TO SHOWERS/SPRINKLES THAT END FROM WEST TO EAST DURING THE AFTERNOON
FROM THE MISSISSIPPI ON EAST.
TEMPERATURES WILL BE TRICKY TODAY AND WILL DEPEND UPON WHEN IT
CLEARS. BASED ON THE CURRENT POSITION OF THE CLOUDS...CLEARING
SHOULD BEGIN AROUND MID DAY IN THE FAR NORTHWEST PARTS OF THE CWFA
THAT SLOWLY MOVES EAST DURING THE AFTERNOON. THE FAR EASTERN PARTS
OF THE CWFA WILL LIKELY CLEAR JUST BEFORE/AFTER SUNSET. AS SUCH THE
EASTERN PARTS OF THE CWFA WILL LIKELY NOT GET OUT OF THE 60S TODAY
WHILE THE WESTERN THIRD TO HALF OF THE CWFA WILL BE IN THE MID 70S.
TONIGHT...QUIET AND DRY CONDITIONS ARE EXPECTED. THE LATE CLEARING
OF THE CLOUDS COMBINED WITH LIGHT WINDS AND WET GROUND RAISES THE
QUESTION OF FOG DEVELOPMENT. BASED ON WHAT IS CURRENTLY HAPPENING
UPSTREAM WHERE IT HAS CLEARED THIS CONCERN APPEARS VALID. FOR NOW
WILL CONFINE ANY MENTION OF FOG TO THE RIVER VALLEYS AND WORD IT AS
PATCHY. SUBSEQUENT SHIFTS WILL HAVE TO RE-EVALUATE THE FOG POTENTIAL
FOR LATE TONIGHT.
08
LONG TERM...TUESDAY THROUGH NEXT SUNDAY...
LIGHT TO MODERATE RAIN EVENT WITH NEXT SIGNIFICANT COLD FRONT LATE
WEDNESDAY INTO THURSDAY REMAINS THE PRIMARY FORECAST ISSUE.
OVERVIEW...
INITIALIZATION AND VERIFICATION IS POOR WITH PRECIPITATION AND
MOISTURE WITH MIDWEST STORM SYSTEM BUT ADEQUATE WITH UPSTREAM ENERGY
AFFECTING DAYS 2-7. VERIFICATION AT 06Z SUPPORTS A 50/50 BLEND OF GFS
AND HI-RES ECMWF WITH ONLY SENSIBLE WEATHER THE MID WEEK FRONTAL
PASSAGE.
TUESDAY/WEDNESDAY...ONLY MINOR CHANGES...FAIR SKIES AND A WARMING
TREND WITH MAXES IN THE LOWER 80S TUESDAY AND MID/UPPER 80S WEDNESDAY
AHEAD OF NEXT FRONT. MINS WEDNESDAY MORNING UPPER 50S TO AROUND 60
DEGREES. SOUTH WINDS TO INCREASE TO 10 TO 20+ MPH BY WEDNESDAY
AFTERNOON. WEDNESDAY NIGHT...AN AREA OR LINE OF SHOWERS AND STORMS TO
MOVE INTO NW SECTIONS BY MIDNIGHT AS COOL FRONT APPROACHES. TIMING
AT NIGHT AND LIMITED INSTABILITY DO NOT SUPPORT SEVERE ATTM WITH
LIGHT TO MODERATE RAIN AMOUNTS. HAVE HIGH CHANCE POPS NW TO SLIGHT
CHANCE POPS SE SECTIONS. MINS MOSTLY IN THE UPPER 60S TO AROUND 70.
THURSDAY...FRONT TO PASS EARLY DURING THE DAY AND TURNING COOLER.
MOST AREAS HAVE LIKELY POPS WITH FRONT SOUTHEAST OF AREA BY MID
AFTERNOON LIMITING CHANCE OF SEVERE. PW/S 1.25-1.5 CONTINUE TO
SUPPORT AT LEAST LIGHT TO MODERATE AMOUNTS OF RAIN. NORTHWEST WINDS
MAY INCREASE TO 15 TO 25 MPH BY MID TO LATE AFTERNOON BEHIND THE
FRONT WITH CLEARING SKIES.
FRIDAY AND SUNDAY...FAIR SKIES...PLEASANTLY COOL AND COMFORTABLE FOR
LATE SUMMER WITH HIGHS MOSTLY IN THE 70S WITH SOME UPPER 60S NORTH
SECTIONS POSSIBLE. THIS IS WELL BELOW NORMAL TEMPERATURES BY 10 TO 15
DEGREES FOR MID AUGUST. LOWS MAY NEED LOWERING BY UP TO 5 DEGREES
WITH MID 40S TO THE MID 50S. THIS MAY THREATEN THE LOW TEMP RECORDS
FOR SATURDAY AND SUNDAY MORNING THAT ARE IN THE UPPER 40S.
NICHOLS
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
703 AM EDT MON AUG 13 2012
.UPDATE...
MORNING SHOWERS HAVE POPPED UP OVER WESTERN MICHIGAN IN
CONJUNCTION WITH A SURGE OF HIGHER THETA E AIR. WHILE MUCH OF THIS
ACTIVITY IS QUICKLY DYING OUT AS IT APPROACHES THE WESTERN
CWA...THE SHOWERS APPROACHING THE SAGINAW VALLEY ARE HOLDING
TOGETHER FAIRLY WELL. THEREFORE WILL RAISE POPS DURING THE MORNING
HOURS GIVEN THE UPTICK IN ACTIVITY THIS MORNING. DESPITE THE
RAISED POPS THESE MORNING SHOWERS WILL BE ISOLATED AND LIGHT IN
NATURE...WITH LITTLE QPF OR A TRACE AMOUNT OF RAIN AS THEY PASS
THROUGH GIVEN THE LOW LEVEL DRY AIR IN PLACE. MAIN EVENT IS STILL
SLATED FOR LATER TODAY AND INTO TONIGHT AS 500 MB SHORTWAVE
EVIDENT ON WATER VAPOR APPROACHES FROM THE WEST.
&&
.AVIATION...ISSUED 653 AM EDT MON AUG 13 2012
//DISCUSSION...
A WEAK RIDGE OF HIGH PRESSURE WILL RESIDE OVER SRN MI THIS MORNING.
WINDS WILL THUS REMAIN QUITE LIGHT THROUGH AT LEAST 15Z. A MID LEVEL
WAVE NOW TRACKING ACROSS THE UPPER MIDWEST WILL ROTATE INTO LOWER MI
THIS AFTERNOON...WHILE THE ASSOCIATED SURFACE LOW REMAINS WELL SOUTH
OF THE STATE. THIS SYSTEM WILL ONLY RESULT IN AN INCREASE IN CLOUDS
ABOVE 10K FT THIS MORNING DUE TO RESIDUAL DRY LOW LEVEL AIR OVER SRN
MI. HOWEVER A FEW SHOWERS MAY MAKE IT OVER MBS THIS MORNING...SO
WILL INCLUDE A TEMPO GROUP TO START THE TAF OUT...BUT SHOULD ONLY
RESULT IN A FEW RAINDROPS WITH LITTLE IF ANY MEASURABLE RAIN.
RAIN WILL THEN OVERSPREAD THE AREA THIS AFTERNOON AND WILL RESULT IN
A RATHER ABRUPT LOWERING IN CEILINGS AND VISIBILITY AS RAIN
INTENSIFIES DURING THE EVENING AND CONTINUE INTO THE OVERNIGHT
HOURS.
FOR DTW...THE APPROACH OF THE UPPER WAVE WILL PROVIDE A GOOD CHANCE
OF RAIN AFTER 20Z. CEILINGS WILL GRADUALLY LOWER DURING THE
DAY...BUT ARE NOT EXPECTED TO DROP BELOW 5000 FT UNTIL AFTER 00Z.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL DROP BELOW 5000 FT AFTER 02Z.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......KURIMSKI
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
653 AM EDT MON AUG 13 2012
.AVIATION...
//DISCUSSION...
A WEAK RIDGE OF HIGH PRESSURE WILL RESIDE OVER SRN MI THIS MORNING.
WINDS WILL THUS REMAIN QUITE LIGHT THROUGH AT LEAST 15Z. A MID LEVEL
WAVE NOW TRACKING ACROSS THE UPPER MIDWEST WILL ROTATE INTO LOWER MI
THIS AFTERNOON...WHILE THE ASSOCIATED SURFACE LOW REMAINS WELL SOUTH
OF THE STATE. THIS SYSTEM WILL ONLY RESULT IN AN INCREASE IN CLOUDS
ABOVE 10K FT THIS MORNING DUE TO RESIDUAL DRY LOW LEVEL AIR OVER SRN
MI. HOWEVER A FEW SHOWERS MAY MAKE IT OVER MBS THIS MORNING...SO
WILL INCLUDE A TEMPO GROUP TO START THE TAF OUT...BUT SHOULD ONLY
RESULT IN A FEW RAINDROPS WITH LITTLE IF ANY MEASURABLE RAIN.
RAIN WILL THEN OVERSPREAD THE AREA THIS AFTERNOON AND WILL RESULT IN
A RATHER ABRUPT LOWERING IN CEILINGS AND VISIBILITY AS RAIN
INTENSIFIES DURING THE EVENING AND CONTINUE INTO THE OVERNIGHT
HOURS.
FOR DTW...THE APPROACH OF THE UPPER WAVE WILL PROVIDE A GOOD CHANCE
OF RAIN AFTER 20Z. CEILINGS WILL GRADUALLY LOWER DURING THE
DAY...BUT ARE NOT EXPECTED TO DROP BELOW 5000 FT UNTIL AFTER 00Z.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL DROP BELOW 5000 FT AFTER 02Z.
&&
.PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GLASGOW MT
847 AM MDT MON AUG 13 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
MORNING UPDATE...
THUNDERSTORMS DEVELOPED EARLIER THIS MORNING ALONG A NOW NON-EXISTENT
THETA-E RIDGE. A THIN SLIVER OF CAPE APPEARS ON THE MORNING
SOUNDING WHICH THE STORMS ARE CONTINUING TO CONSUME FROM ABOUT 700
MB UP. HOWEVER THESE STORMS WILL NEED TO MOVE OUT OF THEIR
LOCATION TO MAINTAIN AND ARE GRADUALLY PUSHING SOUTH AND EAST.
BEST GUESS FOR THE BLAINE COUNTY STORMS IS THROUGH NORTHERN
PHILLIPS AND INTO VALLEY COUNTY THROUGH THE MORNING HOURS. HOWEVER
THEY ARE NOT EXPECTED TO SURVIVE LONG TODAY AND SHOULD BEGIN TO
DISSIPATE INTO REGULAR RAIN SHOWERS BY THE AFTERNOON HOURS. POP
AND SKY GRIDS HAVE BEEN MODIFIED TO ACCOUNT FOR THIS ALONG WITH A
SLIGHT TWEAK TO DAYTIME HIGHS FOR A MINIMAL RAIN COOLED SHADOW.
GAH
PREVIOUS SHORT TERM DISCUSSION...
WEAK DISTURBANCE CROSSING THE NORTHERN ROCKIES THIS MORNING WHICH
HAD RESULTED IN A MCS COMPLEX OVER SOUTHERN ALBERTA THIS MORNING.
THIS MCS IS CURRENTLY HEADING IN THE DIRECTION OF NORTHEAST
MONTANA. SHORT TERM MODELS SUCH AD THE 4 KM WRF AND HRRR HAVE BEEN
SHOWING THIS FEATURE MOST OF THE NIGHT AND THE 00Z NAM AND GFS
HAVE SORT OF CAUGHT ONTO THIS SOLUTIONS. DECIDED TO PUT SLIGHT
CHANCE POPS IN THE FORECAST FOR THIS MORNING AND KEPT IT IN THE
FORECAST THROUGH THIS AFTERNOON. COULD HAVE GONE HIGHER ON THE
POPS BUT SOMETIMES THESE THINGS TEND TO DIE AS THE SUN RISES. DAY
SHIFT MIGHT NEED TO INCREASE POPS LATER THIS MORNING IF THIS THING
IS STILL CHUGGING AWAY IN OUR DIRECTION.
MONDAY AFTERNOON CONTINUED WITH THE SLIGHT CHANCE POPS ACROSS OUR
EAST AS WE ARE LIKE TO SEE A WARM SURGE OF AIR MOVE ACROSS THE
AREA TODAY. A WEAK WARM FRONT IF YOU WILL THAT WILL STALL ACROSS
OUR EASTERN AND NORTHEAST ZONES AND PROVIDE SOME SURFACE
LIFT AS AN UPPER LEVEL DISTURBANCE CROSSES FOR THE NORTHWEST.
DECIDED TO CONTINUE WITH THE SLIGHT CHANCE POPS MONDAY EVENING AND
MONDAY NIGHT ACROSS THE EAST. THE WIND ACROSS THE REGION WILL BE
IN THE 15 TO 20 MPH RANGE WITH OCCASIONAL HIGHER GUSTS. DECIDED TO
HOLD OFF ON A LAKE WIND ADVISORY AND LET THE DAY SHIFT TAKE A
LOOK AT CONDITIONS LATER THIS MORNING. THE CLOUD COVER MIGHT KEEP
THE MIXING DOWN.
TUESDAY THROUGH WEDNESDAY...A WIDE RANGE OF PROBLEMS EXIST IN THIS
TIME FRAME. FIRST OFF WE HAVE A SHORTWAVE OVER NORTHERN BC THAT
WILL EXIT THE FRONT RANGE AND THEN TAP INTO THE ARCTIC AIR MASS
BUILDING OVER NUNAVUT... CREATING AN EXPRESS LANE DOWN THE
CANADIAN PRAIRIES FOR ONE WHOPPER OF A COLD FRONT. THE NEXT
PROBLEM ON TUESDAY WILL COME IN THE AFTERNOON AS COMPRESSIONAL
WARMING OUT AHEAD OF THE COLD FRONT WILL SHOW UP TUESDAY MORNING
AND LAST INTO THE AFTERNOON HOURS. THIS WILL CAUSE THE RELATIVE
HUMIDITIES TO DROP SOUTH OF THE MISSOURI RIVER INTO THE LOWER TEEN.
THE WINDS WILL INCREASE AHEAD OF THIS COLD FRONT IN THE SAME AREA
OUT OF THE WEST TUESDAY AFTERNOON CREATING CRITICAL FIRE WEATHER
CONDITIONS.
THE FRONT WILL BLOW THROUGH THE REGION EARLY WEDNESDAY MORNING AND
OUR TEMPER TUES WILL BEGIN TO DROP. THE WINDS WILL INCREASE DUE TO
THE CAA BEHIND THE FRONT SO EXPECT GUSTY NORTHERLY WINDS TUESDAY
NIGHT THROUGH WEDNESDAY AFTERNOON. A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED FOR THIS TIME FRAME. ALSO ALL PRECIPITATION LOOKS
TO BE POST FRONTAL SO HAVE INCREASED POPS BEHIND THE FRONT THROUGH
WEDNESDAY AFTERNOON. MOSTLY SHOWERS BUT COULD HAVE SOME EMBEDDED
THUNDER WITH THESE SHOWERS. ALSO LOWERED THE HIGHS ON WEDNESDAY AS
I EXPECT SOME AREAS TO STAY IN THE MID 60S ALONG THE INTERNATIONAL
BORDER. VERY FALL LIKE FOR EARLY AUGUST. RSMITH
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FORECAST BEGINS WITH THE STRONG FALL LIKE COLD FRONT
THROUGH THE AREA AND HIGH PRESSURE MOVING IN FROM ALBERTA. THIS
WILL BRING STRONG NORTHWEST FLOW TO THE REGION. THE RESULT WILL BE
DRY AND COOL WEATHER WITH BELOW NORMAL TEMPERATURES FOR THURSDAY
AND FRIDAY.
THEN FOR SATURDAY THROUGH MONDAY A WEST COAST RIDGE BUILDS IN
BRINGING BACK THE ABOVE NORMAL TEMPERATURES AND CONTINUED DRY
WEATHER.
DAY 8 NEXT TUESDAY THE EC AND GFS DO HAVE DIFFERENT IDEAS
THEREFORE WILL OPT FOR DAY 7 PERSISTENCE FOR NOW. PROTON
&&
.AVIATION...
VFR. TWO MCS/S OVER SOUTHERN ALBERTA ARE ON TRACK FOR MOVING INTO
THE AREA EARLY THIS MORNING. BASED ON THEIR CURRENT MOVEMENT THEY
WOULD ARRIVE IN NORTHERN PHILLIPS COUNTY BY 13-14Z... THEN KGGW BY
16-17Z. MODELS DO HAVE THEM MAKING IT TO THE AREA THEREFORE HAVE
FAIR CONFIDENCE THAT TSRA WILL AFFECT THE KGGW LOCATION LATER THIS
MORNING. OTHERWISE ISOLATED TSRA COULD BRING FLIGHT CATEGORIES
DOWN TO MVFR BRIEFLY IF THEY PASS OVERHEAD. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR MTZ122-135>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS GLASGOW MT
418 AM MDT MON AUG 13 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH WEDNESDAY...
WEAK DISTURBANCE CROSSING THE NORTHERN ROCKIES THIS MORNING WHICH
HAD RESULTED IN A MCS COMPLEX OVER SOUTHERN ALBERTA THIS MORNING.
THIS MCS IS CURRENTLY HEADING IN THE DIRECTION OF NORTHEAST
MONTANA. SHORT TERM MODELS SUCH AD THE 4 KM WRF AND HRRR HAVE BEEN
SHOWING THIS FEATURE MOST OF THE NIGHT AND THE 00Z NAM AND GFS
HAVE SORT OF CAUGHT ONTO THIS SOLUTIONS. DECIDED TO PUT SLIGHT
CHANCE POPS IN THE FORECAST FOR THIS MORNING AND KEPT IT IN THE
FORECAST THROUGH THIS AFTERNOON. COULD HAVE GONE HIGHER ON THE
POPS BUT SOMETIMES THESE THINGS TEND TO DIE AS THE SUN RISES. DAY
SHIFT MIGHT NEED TO INCREASE POPS LATER THIS MORNING IF THIS THING
IS STILL CHUGGING AWAY IN OUR DIRECTION.
MONDAY AFTERNOON CONTINUED WITH THE SLIGHT CHANCE POPS ACROSS OUR
EAST AS WE ARE LIKE TO SEE A WARM SURGE OF AIR MOVE ACROSS THE
AREA TODAY. A WEAK WARM FRONT IF YOU WILL THAT WILL STALL ACROSS
OUR EASTERN AND NORTHEAST ZONES AND PROVIDE SOME SURFACE
LIFT AS AN UPPER LEVEL DISTURBANCE CROSSES FOR THE NORTHWEST.
DECIDED TO CONTINUE WITH THE SLIGHT CHANCE POPS MONDAY EVENING AND
MONDAY NIGHT ACROSS THE EAST. THE WIND ACROSS THE REGION WILL BE
IN THE 15 TO 20 MPH RANGE WITH OCCASIONAL HIGHER GUSTS. DECIDED TO
HOLD OFF ON A LAKE WIND ADVISORY AND LET THE DAY SHIFT TAKE A
LOOK AT CONDITIONS LATER THIS MORNING. THE CLOUD COVER MIGHT KEEP
THE MIXING DOWN.
TUESDAY THROUGH WEDNESDAY...A WIDE RANGE OF PROBLEMS EXIST IN THIS
TIME FRAME. FIRST OFF WE HAVE A SHORTWAVE OVER NORTHERN BC THAT
WILL EXIT THE FRONT RANGE AND THEN TAP INTO THE ARCTIC AIR MASS
BUILDING OVER NUNAVUT... CREATING AN EXPRESS LANE DOWN THE
CANADIAN PRAIRIES FOR ONE WHOPPER OF A COLD FRONT. THE NEXT
PROBLEM ON TUESDAY WILL COME IN THE AFTERNOON AS COMPRESSIONAL
WARMING OUT AHEAD OF THE COLD FRONT WILL SHOW UP TUESDAY MORNING
AND LAST INTO THE AFTERNOON HOURS. THIS WILL CAUSE THE RELATIVE
HUMIDITIES TO DROP SOUTH OF THE MISSOURI RIVER INTO THE LOWER TEEN.
THE WINDS WILL INCREASE AHEAD OF THIS COLD FRONT IN THE SAME AREA
OUT OF THE WEST TUESDAY AFTERNOON CREATING CRITICAL FIRE WEATHER
CONDITIONS.
THE FRONT WILL BLOW THROUGH THE REGION EARLY WEDNESDAY MORNING AND
OUR TEMPER TUES WILL BEGIN TO DROP. THE WINDS WILL INCREASE DUE TO
THE CAA BEHIND THE FRONT SO EXPECT GUSTY NORTHERLY WINDS TUESDAY
NIGHT THROUGH WEDNESDAY AFTERNOON. A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED FOR THIS TIME FRAME. ALSO ALL PRECIPITATION LOOKS
TO BE POST FRONTAL SO HAVE INCREASED POPS BEHIND THE FRONT THROUGH
WEDNESDAY AFTERNOON. MOSTLY SHOWERS BUT COULD HAVE SOME EMBEDDED
THUNDER WITH THESE SHOWERS. ALSO LOWERED THE HIGHS ON WEDNESDAY AS
I EXPECT SOME AREAS TO STAY IN THE MID 60S ALONG THE INTERNATIONAL
BORDER. VERY FALL LIKE FOR EARLY AUGUST. RSMITH
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...
THE EXTENDED FORECAST BEGINS WITH THE STRONG FALL LIKE COLD FRONT
THROUGH THE AREA AND HIGH PRESSURE MOVING IN FROM ALBERTA. THIS
WILL BRING STRONG NORTHWEST FLOW TO THE REGION. THE RESULT WILL BE
DRY AND COOL WEATHER WITH BELOW NORMAL TEMPERATURES FOR THURSDAY
AND FRIDAY.
THEN FOR SATURDAY THROUGH MONDAY A WEST COAST RIDGE BUILDS IN
BRINGING BACK THE ABOVE NORMAL TEMPERATURES AND CONTINUED DRY
WEATHER.
DAY 8 NEXT TUESDAY THE EC AND GFS DO HAVE DIFFERENT IDEAS
THEREFORE WILL OPT FOR DAY 7 PERSISTENCE FOR NOW. PROTON
&&
.AVIATION...
VFR. TWO MCS/S OVER SOUTHERN ALBERTA ARE ON TRACK FOR MOVING INTO
THE AREA EARLY THIS MORNING. BASED ON THEIR CURRENT MOVEMENT THEY
WOULD ARRIVE IN NORTHERN PHILLIPS COUNTY BY 13-14Z... THEN KGGW BY
16-17Z. MODELS DO HAVE THEM MAKING IT TO THE AREA THEREFORE HAVE
FAIR CONFIDENCE THAT TSRA WILL AFFECT THE KGGW LOCATION LATER THIS
MORNING. OTHERWISE ISOLATED TSRA COULD BRING FLIGHT CATEGORIES
DOWN TO MVFR BRIEFLY IF THEY PASS OVERHEAD. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR MTZ122-135>137.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
723 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE OHIO VALLEY BY THIS EVENING AND NEAR
LAKE ONTARIO BY LATE TUESDAY. A COLD FRONT WILL SWEEP ACROSS THE REGION
ON TUESDAY. HIGH PRESSURE WILL THEN RETURN TO THE OHIO VALLEY
TUESDAY NIGHT AND WILL PERSIST INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE AT THE SURFACE WILL MOVE EAST TODAY AHEAD OF A
SURFACE LOW AND FRONT. THE WEATHER ISSUES FOR TODAY ARE HOW THICK
WILL THE CLOUDS BE AND WHEN WILL THE SHOWERS MOVE INTO THE AREA
AND WILL THERE BE ANY SPRINKLES BEFORE THE SHOWERS ARRIVE.
THERE WILL BE PLENTY OF CLOUDS TODAY...STARTING OFF AS MID AND
HIGH AND THEN SLOWLY LOWERING. AT THIS TIME LEANING TOWARD MOSTLY
CLOUDY BUT THERE WILL BE SOME FILTERED SUNSHINE. SOME SPRINKLES
HAVE OCCURRED OVER CENTRAL AND SOUTHERN OHIO DURING THE EARLY
MORNING HOURS. WITH THE UPDATE ADDED SPRINKLES TO THE FORECAST FOR
MUCH OF THE AREA THIS MORNING.
WATCHING THE SHOWERS OVER INDIANA. THEY SEEM TO BE DECREASING SOME
AS THEY MOVE EAST. WILL HAVE A CHANCE OF SHOWERS BY 11 AM OVER
EXTREME NORTHWEST OHIO AND THEN SPREAD THE CHANCE EAST. STILL SOME
QUESTION HOW FAR EAST THE SHOWERS COULD SPREAD OR DEVELOP. MANY OF
THE MODELS HAVE QPF OVER THE ENTIRE FORECAST AREA BY 8 PM THIS
EVENING. INCREASED POPS OVER PARTS OF NORTHWEST OHIO THIS
AFTERNOON. MOST INDICATIONS ARE THAT IT WILL BE STABLE
ENOUGH...SO NO MENTION OF THUNDER TODAY. THE HRRR MODEL AND SREF
DATA SEEMS TO AGREE WITH THAT.
HIGH TEMPERATURES ARE TOUGH TODAY WITH THE CLOUDINESS. USED A
BLEND OF GUIDANCE BUT WENT TOWARD THE COOLER SIDE BECAUSE I AM
EXPECTING ONLY LIMITED AMOUNTS OF SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A LOW AND FRONT WILL BE APPROACHING TONIGHT. SLOWLY INCREASING
POPS FROM WEST TO EAST. SOME QUESTION AS TO HOW MUCH THUNDER WILL BE
OCCURRING. WILL NOT DIFFERENTIATE BETWEEN CHANCE THUNDER VERSUS
SHOWERS AND THUNDERSTORMS LIKELY. THE THREAT WILL CONTINUE ON
TUESDAY BUT START DECREASING FROM WEST TO EAST. HIGH PRESSURE WILL
BEGIN BUILDING IN TUESDAY NIGHT AND THEN MOVE EAST ON THURSDAY AS
ANOTHER COLD FRONT APPROACHES FOR THURSDAY NIGHT. AT THIS MOMENT
CONTINUED TO KEEP NORTHWEST OHIO DRY THURSDAY...BUT IT COULD BE
CLOSE. THIS WILL HAVE TO BE MONITORED. THE ECMWF IS A LITTLE
SLOWER THAN THE GFS. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE RATHER QUICKLY ACROSS THE AREA EARLY FRIDAY
MORNING SETTING UP ANOTHER ROUND OF LAKE EFFECT AND LAKE ENHANCEMENT
PRECIPITATION FOR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA. MODELS
DIFFER IN THE TIMING OF THE WIND SHIFT AWAY FROM THE LAKE TO END THE
PRECIPITATION. CURRENT THINKING IS THE PRECIPITATION SHOULD FINALLY
END BY SUNDAY MORNING AS HIGH PRESSURE BECOMES THE DOMINANT FEATURE.
IN THE MEAN TIME PRECIPITATION ASSOCIATED WITH THE COLD FRONT WILL
SWEEP EAST AND OUT OF THE REGION ALLOWING FOR FAIR WEATHER TO RETURN
TO MUCH OF THE FORECAST AREA...EXCEPTION BEING NORTHEAST.
SINCE COLD FRONT MOVES THROUGH THE AREA EARLY FRIDAY
MORNING...MINIMAL RECOVERY IN TEMPERATURES WILL OCCUR ON FRIDAY AS
COLD AIR ADVECTION BEGINS TO TAKE PLACE. COOL DOWN LASTS INTO THE
WEEKEND UNTIL ABOUT SATURDAY WHEN THE SURFACE HIGH MOVES EAST OF THE
REGION AND BEGINS A SLOW WARM UP ACROSS THE AREA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LATEST EUROPEAN MODEL APPEARS TO BE PICKING UP ON A WEAK
SHORTWAVE TROUGH IN THE UPPER LEVELS MOVING EAST TOWARD THE
REGION. THIS FEATURE FITS WELL WITH THE ACTIVITY MOVING THROUGH
INDIANA AT THIS TIME. THIS FEATURE IS PROGGED TO MARCH EAST ACROSS
OUR AREA THIS MORNING AND BE EAST OF THE AREA AFTER 21Z TIME
FRAME. EXPECTING SOME LOWERING OF THE CEILINGS AND VISIBILITIES
OVERNIGHT. OTHERWISE...WINDS SHOULD BE RELATIVELY LIGHT EXCEPT
SLIGHTLY HIGHER WINDS AROUND 10 KNOTS AT MANSFIELD AND AKRON
CANTON. THIS AREA SHOULD END UP SOUTH OF THE WEAK WARM FRONT BY
THIS EVENING.
.OUTLOOK...NON VFR PROBABLE TUESDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
LAKE SHOULD BE RELATIVELY QUIET UNTIL ABOUT TUESDAY NIGHT WHEN
SOUTHWEST FLOW AHEAD OF THE COLD FRONT DEVELOPS. THIS SHOULD KICK UP
WAVES TO BETWEEN 2 AND 3 FEET. COLD FRONT MOVES EAST ACROSS THE LAKE
EARLY FRIDAY MORNING AND WITH COLD AIR ADVECTION TAKING
PLACE...EXPECTING WAVES TO BUILD TO AROUND 4 FEET AND WILL LIKELY
NEED TO HOIST A SMALL CRAFT ADVISORY. AS COLD AIR ADVECTION OCCURS
OVER THE LAKE ON FRIDAY INTO SATURDAY...POTENTIAL FOR WATER SPOUTS
WILL EXIST ONCE AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
649 AM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE EAST TODAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE OHIO VALLEY BY THIS EVENING AND NEAR
LAKE ONTARIO BY LATE TUESDAY. A COLD FRONT WILL SWEEP ACROSS THE REGION
ON TUESDAY. HIGH PRESSURE WILL THEN RETURN TO THE OHIO VALLEY
TUESDAY NIGHT AND WILL PERSIST INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HIGH PRESSURE AT THE SURFACE WILL MOVE EAST TODAY AHEAD OF A
SURFACE LOW AND FRONT. THE WEATHER ISSUES FOR TODAY ARE HOW THICK
WILL THE CLOUDS BE AND WHEN WILL THE SHOWERS MOVE INTO THE AREA
AND WILL THERE BE ANY SPRINKLES BEFORE THE SHOWERS ARRIVE.
THERE WILL BE PLENTY OF CLOUDS TODAY...STARTING OFF AS MID AND
HIGH AND THEN SLOWLY LOWERING. AT THIS TIME LEANING TOWARD MOSTLY
CLOUDY BUT THERE WILL BE SOME FILTERED SUNSHINE. SOME SPRINKLES
HAVE OCCURRED OVER CENTRAL AND SOUTHERN OHIO DURING THE EARLY
MORNING HOURS. WITH THE UPDATE ADDED SPRINKLES TO THE FORECAST FOR
MUCH OF THE AREA THIS MORNING.
WATCHING THE SHOWERS OVER INDIANA. THEY SEEM TO BE DECREASING SOME
AS THEY MOVE EAST. WILL HAVE A CHANCE OF SHOWERS BY 11 AM OVER
EXTREME NORTHWEST OHIO AND THEN SPREAD THE CHANCE EAST. STILL SOME
QUESTION HOW FAR EAST THE SHOWERS COULD SPREAD OR DEVELOP. MANY OF
THE MODELS HAVE QPF OVER THE ENTIRE FORECAST AREA BY 8 PM THIS
EVENING. INCREASED POPS OVER PARTS OF NORTHWEST OHIO THIS
AFTERNOON. MOST INDICATIONS ARE THAT IT WILL BE STABLE
ENOUGH...SO NO MENTION OF THUNDER TODAY. THE HRRR MODEL AND SREF
DATA SEEMS TO AGREE WITH THAT.
HIGH TEMPERATURES ARE TOUGH TODAY WITH THE CLOUDINESS. USED A
BLEND OF GUIDANCE BUT WENT TOWARD THE COOLER SIDE BECAUSE I AM
EXPECTING ONLY LIMITED AMOUNTS OF SUNSHINE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
A LOW AND FRONT WILL BE APPROACHING TONIGHT. SLOWLY INCREASING
POPS FROM WEST TO EAST. SOME QUESTION AS TO HOW MUCH THUNDER WILL BE
OCCURRING. WILL NOT DIFFERENTIATE BETWEEN CHANCE THUNDER VERSUS
SHOWERS AND THUNDERSTORMS LIKELY. THE THREAT WILL CONTINUE ON
TUESDAY BUT START DECREASING FROM WEST TO EAST. HIGH PRESSURE WILL
BEGIN BUILDING IN TUESDAY NIGHT AND THEN MOVE EAST ON THURSDAY AS
ANOTHER COLD FRONT APPROACHES FOR THURSDAY NIGHT. AT THIS MOMENT
CONTINUED TO KEEP NORTHWEST OHIO DRY THURSDAY...BUT IT COULD BE
CLOSE. THIS WILL HAVE TO BE MONITORED. THE ECMWF IS A LITTLE
SLOWER THAN THE GFS. USED A BLEND OF GUIDANCE FOR THE
TEMPERATURES.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE RATHER QUICKLY ACROSS THE AREA EARLY FRIDAY
MORNING SETTING UP ANOTHER ROUND OF LAKE EFFECT AND LAKE ENHANCEMENT
PRECIPITATION FOR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA. MODELS
DIFFER IN THE TIMING OF THE WIND SHIFT AWAY FROM THE LAKE TO END THE
PRECIPITATION. CURRENT THINKING IS THE PRECIPITATION SHOULD FINALLY
END BY SUNDAY MORNING AS HIGH PRESSURE BECOMES THE DOMINANT FEATURE.
IN THE MEAN TIME PRECIPITATION ASSOCIATED WITH THE COLD FRONT WILL
SWEEP EAST AND OUT OF THE REGION ALLOWING FOR FAIR WEATHER TO RETURN
TO MUCH OF THE FORECAST AREA...EXCEPTION BEING NORTHEAST.
SINCE COLD FRONT MOVES THROUGH THE AREA EARLY FRIDAY
MORNING...MINIMAL RECOVERY IN TEMPERATURES WILL OCCUR ON FRIDAY AS
COLD AIR ADVECTION BEGINS TO TAKE PLACE. COOL DOWN LASTS INTO THE
WEEKEND UNTIL ABOUT SATURDAY WHEN THE SURFACE HIGH MOVES EAST OF THE
REGION AND BEGINS A SLOW WARM UP ACROSS THE AREA.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
CLOUDS CONTINUE TO MOVE EAST TOWARD THE REGION AT THIS TIME IN
ADVANCE OF THE NEXT STORM SYSTEM. MODELS HINTING AT THE FIRST
ARRIVAL OF MEASURABLE RAIN TO ARRIVE IN TOLEDO FINDLAY AREA BY
00Z THIS EVENING. PRECIPITATION WILL GRADUALLY SPREAD FROM WEST TO
EAST DURING THE NIGHT. PRECIPITATION SHOULD NOT REACH AKRON
CANTON...YOUNGSTOWN AND ERIE UNTIL AFTER THIS TAF PERIOD. CEILINGS
AND VISIBILITIES ARE EXPECTED TO REMAIN VFR THROUGH THE TAF PERIOD
BUT DROP TO MVFR AFTER 06Z AT CLEVELAND. WINDS SHOULD BE LIGHT
THROUGH TODAY BUT START TO INCREASE AS WARM FRONT LIFTS NORTH
ACROSS THE REGION. EXPECTING THE HIGHER WINDS AROUND 10 KNOTS
SOUTH OF THE FRONTAL BOUNDARY...ESPECIALLY AT AKRON CANTON.
.OUTLOOK...NON VFR PROBABLE TUESDAY IN SHOWERS/THUNDERSTORMS.
&&
.MARINE...
LAKE SHOULD BE RELATIVELY QUIET UNTIL ABOUT TUESDAY NIGHT WHEN
SOUTHWEST FLOW AHEAD OF THE COLD FRONT DEVELOPS. THIS SHOULD KICK UP
WAVES TO BETWEEN 2 AND 3 FEET. COLD FRONT MOVES EAST ACROSS THE LAKE
EARLY FRIDAY MORNING AND WITH COLD AIR ADVECTION TAKING
PLACE...EXPECTING WAVES TO BUILD TO AROUND 4 FEET AND WILL LIKELY
NEED TO HOIST A SMALL CRAFT ADVISORY. AS COLD AIR ADVECTION OCCURS
OVER THE LAKE ON FRIDAY INTO SATURDAY...POTENTIAL FOR WATER SPOUTS
WILL EXIST ONCE AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KIELTYKA
NEAR TERM...KIELTYKA
SHORT TERM...KIELTYKA
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
647 AM EDT MON AUG 13 2012
.SYNOPSIS...
LOW PRESSURE AND ITS ASSOCIATED COLD FRONT WILL SLOWLY TRACK EAST
ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY THROUGH TUESDAY. HIGH
PRESSURE WILL THEN BUILD BACK ACROSS THE REGION BY THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS ARE IN FAIRLY DECENT AGREEMENT IN TERMS OF SYNOPTIC SCALE
SYSTEMS AND THEIR ASSOCIATED STRENGTH AND TIMING. HOWEVER...THERE
WILL BE SOME POTENTIAL PITFALLS IN THE NEAR TERM FORECAST.
SURFACE ANALYSIS DEPICTED AN AREA OF WEAK LOW PRESSURE OVER NE
MISSOURI THIS MORNING. MOSAIC RADAR TO OUR WEST WAS SHOWING A
SIZABLE AREA OF SHOWERS AND EMBEDDED THUNDERSTORMS EXTENDING FROM
NW INDIANA SW ACRS MUCH OF ILLINOIS THEN INTO MISSOURI. THE SHOWERS
ACROSS THE NORTHERN SECTIONS OF ILLINOIS AND INDIANA APPEAR TO BE
THE RESULT OF MID LVL ISENTROPIC LIFT OCCURRING IN THE 8 TO 12 K FT
RANGE. FARTHER SOUTH...SHOWERS AND EMBEDDED THUNDERSTORMS WERE
BEING AIDED BY A 925-850 MB LOW LEVEL JET. IT APPEARS THAT THE
SHOWERS ACRS NRN ILLINOIS AND NW INDIANA WILL PUSH EAST THIS
MORNING AWAY FROM ITS ISENTROPIC SOURCE REGION TOWARD OUR NW
FORECAST AREA. IT IS STILL UNCLEAR AT THIS POINT HOW LONG THESE
SHOWERS WILL STAY IN TACT AS THEY CONTINUE TO MOVE EAST AWAY FROM
THEIR SOURCE REGION. HAVE WENT AHEAD AND GONE WITH LIKELY POPS ACRS
OUR NW ZONES AS THE LATEST HRRR MODEL INDICATES THAT THE SHOWERS
SHOULD AT LEAST MAKE IT HERE BEFORE THEY WEAKEN FURTHER TOWARD THE
AFTERNOON HOURS. FARTHER SOUTH...IT BECOMES TRICKY CONSIDERING
AFOREMENTIONED LOW LEVEL JET WILL WEAKEN SOME TOWARD MORNING. HAVE
PLACED CHANCES POPS HERE AND WILL MONITOR RADAR TRENDS AND HRRR
TRENDS SHOULD HIGHER POPS BE NEEDED. IT APPEARS THAT ALL PCPN
SHOULD BE IN THE FORM OF SHOWERS THROUGH EARLY AFTN AS HIGHER
INSTABILITY IS EXPECTED TO REMAIN TO OUR WEST.
THEREAFTER...MID LVL S/WV WILL CONTINUE TO DIG SE ACRS THE WESTERN
GREAT LAKES THROUGH THE REMAINDER OF THE DAY AS SFC LOW PRESSURE
MOVES TOWARD THE ENE TO SRN INDIANA BY THIS EVENING. THERE SHOULD
BE A RELATIVE LULL IN THE PCPN ACTIVITY THIS AFTERNOON BEFORE
HIGHER CHANCES OF SHOWERS/STORMS ARRIVE TONIGHT.
TEMPERATURES WILL BE HARD TO PIN DOWN GIVEN THE TIMING OF PCPN
AND THE AMOUNT OF CLOUD COVER THAT WILL OCCUR FROM TIME TO TIME
TODAY. HAVE TAKEN A BLEND OF ALL AVAILABLE OPERATIONAL MODELS
WHICH YIELD HIGHS FROM THE UPPER 70S NORTHWEST TO THE MID 80S
ALONG AND SOUTH OF THE OHIO RIVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
MID LVL S/WV WILL CONTINUE EAST ACRS OUR AREA OVERNIGHT AS SFC LOW
PRESSURE AND WEAK COLD FRONT MOVE EAST AS WELL. THERE IS ENOUGH
EVIDENCE BY THE MODELS TO GO AHEAD AND RAMP POPS UP INTO THE
LIKELY CATEGORY FOR ALL LOCATIONS AS THERE SHOULD BE ENOUGH LOW
LEVEL CONVERGENCE PER A LOW LEVEL JET AND UPR LVL SUPPORT.
ON TUESDAY...LOW PRESSURE WILL SLOWLY MOVE OFF TO THE NE. ITS
ASSOCIATED WEAK COLD FRONT WILL MEANDER SLOWLY EAST AS WELL.
LIKELY POPS ARE EXPECTED EARLY ON ACRS OUR ERN ZONES...THEN POPS
WILL SLOWLY DECREASE THROUGH THE DAY AS DRIER AIR SLOWLY
INFILTRATES FROM THE WEST.
WEAKENING FRONTAL BOUNDARY IS EXPECTED TO BE EAST OF THE AREA BY
WEDNESDAY NIGHT AS WEAK SFC HIGH PRESSURE BUILDS IN FROM THE WEST.
SKIES WILL GRADUALLY CLEAR.
HIGH PRESSURE WILL SETTLE ACROSS THE OHIO VALLEY ON WEDNESDAY.
MOSTLY SUNNY SKIES ARE EXPECTED WITH SLIGHTLY BELOW NORMAL
TEMPERATURES FOR MID AUGUST. THE HIGH WILL BEGIN TO MOVE EAST OF
THE AREA WEDNESDAY NIGHT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS THE HIGH CONTINUES OFF TO THE EAST ON THURSDAY...WE WILL GET
INTO A RETURN FLOW... RESULTING IN THE WARMEST DAY OF THE WEEK
WITH HIGHS INTO THE UPPER 80S TO THE LOWER 90S.
THE 00Z ECMWF HAS CONTINUED TO TREND SLOWER WITH THE APPROACH OF THE
NEXT SHORT WAVE FOR LATE IN THE WORK WEEK AND IS NOW ABOUT 18 HOURS
OR SO SLOWER THAN THE 12Z GFS. THE 12Z CMC IS ALSO TRENDING SLOWER
SO HAVE TRIMMED BACK THE ONSET OF PCPN FOR THURSDAY NIGHT...WITH THE
BEST CHANCE ON INTO FRIDAY. IT LOOKS LIKE A PRETTY GOOD CHANCE FOR
PCPN SOMETIME THURSDAY NIGHT INTO FRIDAY...BUT GIVEN THE TIMING
ISSUES AM HESITANT TO GO HIGHER THAN CHANCE AT THIS POINT FOR ANY
GIVEN PERIOD. A MUCH COOLER AIRMASS WILL FILTER DOWN INTO OUR AREA
FOR THE WEEKEND AS A 500 MB LOW SETTLES IN OVER THE WESTERN GREAT
LAKES. 850 MB TEMPERATURES WILL DROP DOWN INTO THE 6 TO 8 DEGREE
RANGE AT TIMES SATURDAY INTO SUNDAY. THIS WOULD KEEP HIGHS BOTH
DAYS GENERALLY IN THE LOWER 70S.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
THROUGH THE FIRST PART OF THE DAY...ISOLATED SHOWERS ARE EXPECTED
TO BE POSSIBLE. WHILE THIS ACTIVITY WOULD BE MOST LIKELY AT THE
CINCINNATI TAF SITES (AS DENOTED WITH A TEMPO GROUP)...THEY WILL
BE POSSIBLE AT ALL THE TAF SITES AS THE MORNING PROGRESSES (AND
EARLY AFTERNOON FOR COLUMBUS). THE AIR MASS IS STILL
SATURATING...SO THESE SHOWERS SHOULD REMAIN VFR...GENERALLY
FALLING OUT OF CLOUD DECKS ABOVE 5000 FEET (SOME OF THEM UP INTO
THE MID LEVELS).
ADDITIONAL SHOWERS AND POSSIBLY SOME THUNDERSTORMS WILL DEVELOP
DURING THE LATE AFTERNOON AND EVENING. CONFIDENCE IN THUNDERSTORM
COVERAGE IS NOT PARTICULARLY HIGH...SO THUNDER HAS BEEN EXCLUDED
FROM THE TAFS AT THIS TIME. INSTABILITY WILL BE GREATEST IN THE
SOUTHWEST PART OF THE ILN CWA...MEANING THAT THE CINCINNATI TAF
SITES WILL HAVE THE GREATEST CHANCE FOR THUNDER. WHETHER OR NOT
THUNDER OCCURS...SOME OF THE HEAVIER SHOWERS WILL BE CAPABLE OF
MVFR OR MAYBE EVEN IFR CONDITIONS.
OVERALL...THE GREATEST CHANCE FOR PRECIPITATION WILL COME DURING
THE OVERNIGHT HOURS AS A SURFACE LOW MOVES THROUGH THE REGION.
MOST OF THIS RAIN (POSSIBLY WITH SOME EMBEDDED THUNDER) WILL ALSO
REMAIN VFR...BUT BY DAYBREAK TUESDAY...SOME OF THE CEILINGS ARE
EXPECTED TO BE DROPPING INTO THE MVFR RANGE.
.OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE TUESDAY...ALONG WITH
MVFR AND POSSIBLY IFR CEILINGS.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...HICKMAN
NEAR TERM...HICKMAN
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/JGL
AVIATION...HATZOS
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
949 AM CDT MON AUG 13 2012
.UPDATE...
MINOR UPDATES FOR TODAY FOR OBSERVED TRENDS AND TO CLEAN UP ZONE
WORDING.
&&
.DISCUSSION...
24 HOUR DIFFERENCE FROM 14Z YESTERDAY SHOWS MOST LOCATIONS AT OR
WITHIN A DEGREE OF YESTERDAY. SMALL UPDATES TO HOURLY/MAX TEMPS
AND DEW POINTS FOR TODAY. STILL HOT AND HUMID WITH HEAT INDICES IN
THE 100-105 RANGE. FCST SOUNDINGS AND MDCRS/AIRCRAFT SOUNDINGS
THIS MORNING SHOW 11 TO 12C 700MB TEMPERATURES WHICH SHOULD KEEP
CONVECTION ISOLATED ALONG THE SEA BREEZE TODAY. DID INCLUDE ISO
POPS FOR SOUTHERN COUNTIES JUST INLAND PER 11Z HRRR FCST
REFLECTIVITY FIELDS. SLIGHTLY BETTER SHRA/TSRA CHANCES FOR
NORTHERN AND NORTHEASTERN COUNTIES THIS AFTERNOON FROM LEFTOVER
OUTFLOW BOUNDARIES AND CLOSER TO 850MB TROUGH EVIDENT IN AREA
VWP/PROFILER WINDS. 04
&&
.PREV DISCUSSION... /ISSUED 701 AM CDT MON AUG 13 2012/
DISCUSSION...
12Z TAF DISCUSSION IN AVIATION SECTION BELOW.
AVIATION...
MONITORING SHORT WAVE TROUGH AXIS ROTATING THROUGH NE TX WHICH
HAS KICKED OFF A FEW ISO TSRA TO THE NE OF KUTS/KCXO. POSSIBLE
THAT A FEW SHOWERS/TCU COULD WORK THROUGH THE TERMINALS THIS
MORNING BUT THINK CAPPING IS STRONG ENOUGH FOR NOW. WITH THE
PASSING OF THIS WAVE...MAY HAVE WEAKENED THE CAP ENOUGH FOR ISO TO
SCT TSRA BY THE AFTERNOON. LOCAL WRF-ARW HAS CONVECTION DEVELOPING
AROUND 21-22Z ALONG A PREFRONT TROUGH AHEAD OF A FRONTAL BOUNDARY
THAT COULD AFFECT KCLL/KUTS/KCXO TERMINALS. POSSIBLE SOME OF THIS
CONVECTION COULD WORK SOUTH INTO THE HOUSTON TERMINALS WHILE SEA
BREEZE PUSHES UP FROM THE SOUTH. SEA BREEZE COULD BE THE OTHER
FOCUS FOR CONVECTION SO DECIDED TO AT LEAST PUT VCTS FOR
KCLL/KUTS/KCXO AND KIAH. MODELS NOT REALLY INITIATING CONVECTION
ON THE SEA BREEZE SO NOT AS CONFIDENT WITH VCTS IN KHOU/KSGR TAFS.
WILL LIKELY NEED TO UPDATE OR AMEND DEPENDING ON CONVECTIVE
TRENDS. OTHERWISE EXPECT VFR CIGS WITH SW WINDS BECOMING S/SE WITH
THE DEVELOPING SEA BREEZE DURING THE AFTERNOON.
39
PREV DISCUSSION... /ISSUED 548 AM CDT MON AUG 13 2012/
UPDATE...
A QUICK UPDATE FOR SHOWERS AND THUNDERSTORMS DEVELOPING NEAR
GROVETON WITH THE PASSAGE OF S/W TROUGH AND OTHER SHOWERS AND
THUNDERSTORMS TO THE NORTH NEAR THE SHEAR AXIS. EXPECT THESE TO
WEAKEN AROUND 8-10 AM AND REMAIN GENERALLY NORTH OF MADISONVILLE
TO LIVINGSTON LINE.
45
PREV DISCUSSION... /ISSUED 433 AM CDT MON AUG 13 2012/
DISCUSSION...
UPPER RIDGING OVER NEW MEXICO/WEST TEXAS WILL FLATTEN WITH
NORTHWEST FLOW FROM COLORADO TO MISSISSIPPI WITH SETX ON THE
EASTERN PERIPHERY OF THE RIDGING. S/W TRACKING THROUGH ARKANSAS
THIS MORNING MAY BE AIDING DEVELOPMENT OF SHRA/TSRA NORTHEAST OF
THE AREA NEAR LUFKIN. ANOTHER S/W IN EASTERN COLORADO WILL SWING
DOWN TO THE NORTHERN ZONES LATE THIS AFTERNOON WHICH SHOULD
PROVIDE SOME LIFT BUT THE RIDGES INFLUENCE WITH VERY WARM PROFILES
SHOULD FIGHT THIS WITH CAPPING. THE GREATER CHANCES THOUGH SLIM
WILL BE THE OVER THE NORTHERN COUNTIES THIS AFTERNOON AND EVENING.
ISOLATED SHOWERS OR A THUNDERSTORM WILL BE POSSIBLE NEAR THE COAST
ALONG THE LATE AFTERNOON SEABREEZE. SPEAKING OF SLIM RAIN CHANCES
THESE WILL CONTINUE THROUGH THURSDAY MAINLY DURING THE LATE
AFTERNOON HOURS NEAR THE COAST AND EASTERN COUNTIES WITH THE
WEAKENING OF THE RIDGE AND DAYTIME HEATING POSSIBLY AIDED BY THE
SERIES OF S/W TRACKING SOUTH FROM THE PLAINS INTO THE PERSISTENT
EASTERN U.S. TROUGH UP THROUGH THE GREAT LAKES. EXPECTING
TEMPERATURES DOWN A DEGREE OR TWO THE NEXT FEW DAYS. A LITTLE
DRIER AS WELL SO HEAT INDEX READINGS SHOULD BE IN THE 100-105
DEGREE RANGE...SO NO HEAT ADVISORY NEEDED GIVEN CURRENT FORECAST.
RAIN CHANCES INCREASING ON FRIDAY AS STRONGER S/W MOVES SE TOWARD
THE AREA AND A WEAK COLD FRONT DRIFTS SOUTHWARD TO THE RED
RIVER/NORTHEAST TEXAS REGION. THIS WOULD MAKE FOR GOOD SOURCE OF
THUNDERSTORMS AND WITH THE NORTHWEST/NORTH FLOW ALOFT WOULD CARRY
THESE SOUTH INTO SETX. IN ADDITION AN OPEN WAVE (POSSIBLY REMNANTS
OF TD7) WILL TRACK INTO THE SOUTHWEST GULF PUSHING RICHER MOISTURE
UP INTO SETX LATE FRIDAY THROUGH SUNDAY. COOLING FROM THE CLOUD
COVER AND RETREAT OF RIDGING WESTWARD THIS COMING WEEKEND SHOULD
BRING SOME RELIEF FROM HIGHS IN THE MID- UPPER 90S DURING MID WEEK
TIME FRAME. 45
MARINE...
OVERALL NOT A LOT OF CHANGE IN THE FORECAST AS A TYPICAL SUMMER TIME
PATTERN PERSISTS OVER THE UPPER TX COAST. MODERATE SOUTHERLY WINDS
SHOULD CONTINUE WITH LOW SEAS.
39
AVIATION...
ANOTHER WEAK FRONTAL BOUNDARY MAY APPROACH SE TX TODAY. LOCAL WRF-
ARW SHOWING SOME CONVECTION FORMING FROM KCLL TO KUTS AROUND 22-23Z
THIS EVENING JUST SOUTH OF THE BOUNDARY. OTHERWISE MAY SEE SOME ISO
STORMS FORM ALONG THE SEA BREEZE AGAIN. COVERAGE OF STORMS IS NOT
EXPECTED TO BE ALL THAT MUCH SO WILL LIKELY GO WITH THE WAIT AND SEE
ROUTE. WILL KEEP MENTION OF CONVECTION OUT OF TAFS AND THEN AMEND
ACCORDINGLY AS CONVECTION DEVELOPS IF AT ALL. OTHERWISE THINK VFR
CIGS WILL BE EXPECTED WITH SW/S WINDS TURNING TO THE SE BEHIND THE
SEA BREEZE FOR TERMINALS ALONG THE COAST.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 99 / 20 10 10 10 10
HOUSTON (IAH) 96 78 97 77 96 / 20 10 20 10 10
GALVESTON (GLS) 91 82 90 82 90 / 10 10 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AREA FORECAST DISCUSSION...UPDATED
NWS LITTLE ROCK AR
1223 PM CDT MON AUG 13 2012
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION BELOW...
&&
.AVIATION...
FRONT PUSHING SE ACROSS THE STATE THIS AFTERNOON...WITH DRIER AIR
FILTERING INTO WRN SECTIONS OF THE STATE. THIS WILL KEEP VFR
CONDITIONS IN PLACE FOR MOST TAF SITES. SOME SHRA/TSRA WILL BE
POSSIBLE AHEAD OF THE FRONT THIS AFTERNOON...MAINLY ACROSS FAR ERN
AND SERN SECTIONS OF AR. HAVE MENTIONED VCTS AT LLQ FOR THIS
REASON. TAFS ALREADY OUT.
&&
.PREV DISCUSSION... /ISSUED 1043 AM CDT MON AUG 13 2012/
UPDATE...
15Z SURFACE ANALYSIS INDICATES THE COLD FRONT HAS REACHED A LINE
FROM FLIPPIN...TO JUST SOUTH OF MENA. FORECASTS HAVE BEEN ADJUSTED
TO LOWER PRECIPITATION CHANCES THIS AFTERNOON...AS A FAIR AMOUNT
OF CONVECTIVE OVERTURNING HAS OCCURRED AHEAD OF THE BOUNDARY.
55
PREV DISCUSSION... /ISSUED 500 AM CDT MON AUG 13 2012/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT
WL BE BRIEF THIS MRNG DUE TO STRONG/SVR STORMS OVR THE AREA. WARM
FNT WAS LOCATED ACRS CNTRL AR EARLY THIS MRNG. CONVECTION DVLPD
UPSTREAM OF THE FA LATE SUN EVENING AND EVENTUALLY TRACKED ALONG THE
BNDRY OVERNIGHT INTO NRN AND CNTRL AR. THIS ACTIVITY IS EXPECTED TO
CONT WORKING EWD THRU THE MRNG HRS AS ASSOCD SHRTWV MOVES THRU THE
REGION.
AFTER THE MRNG CONVECTIVE ACTIVITY...FOCUS WL SHIFT TO THE CDFNT
THAT WL MOVE THRU THE AREA LATER TODAY AND EARLY TNGT. THE FNT WAS
CURRENTLY ALONG THE I-44 CORRIDOR. THE POTENTIAL FOR STORMS TO FIRE
ALONG THE ACTUAL FNTL BNDRY LATER TODAY IS THE MAIN CONCERN. LAST
FEW RUNS OF THE HRRR MODEL INDC THAT SCTD STORMS SHLD DVLP THIS
AFTN...MAINLY ACRS ERN AND SRN AR.
FNTL BNDRY WL EVENTUALLY STALL OUT S OF AR BY TUE AS HIGH PRES BLDS
INTO THE REGION. HOWEVER...NWLY FLOW ALOFT WL BRING SEVERAL IMPULSES
SEWD TOWARD THE FA LATER TUE AND WED. THESE FEATURES WL PRODUCE SCTD
CONVECTION OVR PORTIONS OF THE AREA...WITH THE MAIN FOCUS ACRS THE
SWRN HALF OF THE STATE. UNSETTLED CONDS WL CONT INTO THE LONG TERM
AS A NEW CDFNT APCHS FM THE PLAINS.
LONG TERM...THURSDAY THROUGH SUNDAY
GUIDANCE IN RELATIVELY GOOD AGREEMENT IN THE LONG TERM IN SHOWING
WIDESPREAD RAINFALL FOR THE END OF THE WEEK. WARM FRONT WILL MOVE
NORTH THURSDAY BRINGING GULF MOISTURE TO THE STATE...AND COLD FRONT
WILL APPROACH THURSDAY NIGHT INTO FRIDAY. THERE IS A POSSIBILITY FOR
SOME SIGNIFICANT RAINFALL...BUT THIS SYSTEM IS SEVERAL DAYS
AWAY...AND SEVERAL DETAILS WILL NEED TO IRONED OUT IN REGARDS TO
RAINFALL AMOUNTS. THE GOOD NEWS IS THAT COOLER TEMPERATURES WILL
FOLLOW THE FRONT...WITH HIGHS IN THE 80S AND LOWER 90S.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 91 65 86 65 / 30 10 10 10
CAMDEN AR 95 67 91 67 / 50 20 10 20
HARRISON AR 88 63 84 66 / 10 0 10 10
HOT SPRINGS AR 95 67 89 67 / 30 10 20 20
LITTLE ROCK AR 93 67 87 67 / 40 10 10 20
MONTICELLO AR 94 69 89 68 / 50 20 10 10
MOUNT IDA AR 93 65 89 64 / 20 10 20 20
MOUNTAIN HOME AR 89 63 85 63 / 10 0 10 10
NEWPORT AR 91 66 86 65 / 40 10 10 10
PINE BLUFF AR 93 67 88 66 / 50 20 10 10
RUSSELLVILLE AR 91 67 88 66 / 10 10 10 20
SEARCY AR 90 66 86 65 / 40 10 10 10
STUTTGART AR 91 67 87 66 / 50 20 10 10
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AVIATION...62
AREA FORECAST DISCUSSION
NWS TUCSON AZ
220 PM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TUESDAY WITH RECORD OR
NEAR RECORD HIGHS IN SOME LOCATIONS. OTHERWISE...EXPECT A GRADUAL
INCREASE IN THUNDERSTORM CHANCES AND A GRADUAL COOLING TREND THIS
WEEK.
&&
.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS ONGOING ACROSS SE
AZ AT THIS TIME. 18Z RUC HRRR FAVORS THE TOHONO O`ODHAM NATION WITH
THE MOST SIGNIFICANT SHOWER/TSTM ACTIVITY DURING THE NEXT FEW HOURS.
MEANWHILE...ADDITIONAL SHOWERS/TSTMS ARE PROGGED TO DEVELOP FURTHER
EAST AND SOUTH OF TUCSON LATE THIS AFTERNOON AND EARLY THIS EVENING.
13/18Z SPECIAL KTWC SOUNDING YIELDED A FAIRLY DRY REGIME...WITH
PRECIP WATER AROUND 0.90 INCH WITH MINIMAL CAPE. STEERING FLOW WAS
SELY ONLY AROUND 5 KTS OR SO. THUS...THE MAIN THREAT DURING THE NEXT
FEW HOURS WILL BE BRIEF STRONG WIND GUSTS FOLLOWED BY PERHAPS
LOCALLY HEAVY RAINFALL LATE THIS AFTERNOON AND EARLY THIS EVENING.
THE OFFICIAL FORECAST DEPICTS SCATTERED SHOWERS/TSTMS MOST SECTIONS
THRU THIS EVENING. HAVE MAINTAINED A SLIGHT CHANCE OF SHOWERS/TSTMS
EAST AND SOUTH OF TUCSON LATE TONIGHT WITH GENERALLY PRECIP-FREE
CONDITIONS ELSEWHERE.
TUE-FRI...
DAILY PRECIP CHANCES WILL INCREASE ESPECIALLY THUR-FRI AS FAVORABLE
FLOW IMPORTS DEEPER MOISTURE INTO SE AZ. IN SUMMARY...SCATTERED
MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS TO OCCUR PARTICULARLY
FROM TUCSON EWD/SWD WITH SLIGHTLY LESSER SHOWER/TSTM ACTIVITY ACROSS
WRN SECTIONS.
SAT-MON...
SLIGHTLY LESS SHOWER/TSTM ACTIVITY THIS PERIOD VERSUS THUR-FRI.
THERE WILL STILL BE ENOUGH MOISTURE TO JUSTIFY CHANCE-CATEGORY POPS
MOST SECTIONS...ESPECIALLY DURING THE AFTERNOON/EVENING HOURS. AT
THIS TIME APPEARS THAT THE FAVORED AREAS FOR SHOWERS/TSTMS WILL BE
ACROSS THE WHITE MOUNTAINS AS WELL AS ACROSS SANTA CRUZ COUNTY AND
SOUTHERN COCHISE COUNTY.
HIGH TEMPS TUE WILL STILL AVERAGE NEARLY 10 DEGS F ABOVE NORMAL.
COOLING TREND TO OCCUR WED-FRI DUE TO THE PROSPECT FOR INCREASED
MOISTURE ACROSS THE AREA. DAYTIME TEMPS SAT-MON EXPECTED AT THIS
TIME TO BE SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA INTO THIS EVENING THEN A SLIGHT
CHANCE OF -TSRA/-SHRA EAST OF KTUS 06Z-12Z TUESDAY. SCT TSRA/SHRA
TUESDAY AFTERNOON. OTHERWISE...VFR CONDITIONS AND SURFACE WIND
GENERALLY LESS THAN 10 KTS THRU TUESDAY AFTERNOON OR 15/00Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS THROUGH THE WEEKEND. STRONG...ERRATIC AND GUSTY WINDS
WILL OCCUR WITH THE STRONGEST THUNDERSTORMS. OTHERWISE...A GRADUAL
COOLING TREND WILL OCCUR THROUGH FRIDAY ALONG WITH NORMAL DIURNAL
WIND TRENDS.
&&
.CLIMATE...THE FORECAST HIGH TEMPERATURE TODAY FOR THE TUCSON
INTERNATIONAL AIRPORT IS 110 DEGREES. NOT ONLY WILL THIS TEMPERATURE
SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING THE OLD RECORD OF
106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT WOULD ALSO BE THE
FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST SINCE 1994 WHEN IT
OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO...TODAY WILL BE 8
STRAIGHT DAYS WITH A HIGH OF 105 DEGREES OR WARMER IN TUCSON...
WHICH IS 2 DAYS SHY OF THE AUGUST RECORD OF DAYS THAT OCCURRED IN
1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 6 PM MST THIS EVENING FOR AZZ501-502-504-505.
$$
AREA FORECAST DISCUSSION
NWS TUCSON AZ
930 AM MST MON AUG 13 2012
.SYNOPSIS...EXPECT HOT DAYTIME TEMPERATURES TODAY AND TUESDAY WITH
RECORD OR NEAR RECORD HIGHS IN SOME LOCATIONS. STILL ENOUGH MOISTURE
FOR ISOLATED THUNDERSTORMS TODAY. SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL THEN OCCUR FOR THE REMAINDER OF THE WEEK
AS MOISTURE INCREASES ACROSS THE AREA.
&&
.DISCUSSION...KEMX WSR-88D DETECTED ISOLATED 30-50 DBZ ECHOES MOVING
NWWD ACROSS NRN CENTRAL PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY
AT 1605Z. THE REST OF SE AZ WAS VOID OF PRECIP ECHOES AT THIS TIME.
DEWPOINTS VALID 16Z GENERALLY RANGED FROM THE UPPER 40S-50S F...AND
THESE TEMPS WERE NEARLY 5-10 DEGS F LOWER VERSUS 24 HOURS AGO.
13/12Z KTWC SOUNDING PRECIP WATER VALUE WAS SIMILAR TO 24 HOURS
AGO...AND DEPICTED A VERY DRY SURFACE-700 MB LAYER. 13/12Z UPPER AIR
PLOTS INDICATED 594 DM HIGH CENTERED OVER CENTRAL NEW MEXICO AND
BROAD TROUGH WAS OVER THE ERN CONUS. LIGHT SELY/SLY FLOW PREVAILED
ABOVE 700 MB ACROSS SE AZ.
OUTFLOW BOUNDARY FROM SHOWERS/TSTMS THAT OCCURRED LAST NIGHT MOSTLY
ACROSS ERN NEW MEXICO WAS ADVANCING WWD ACROSS CENTRAL PIMA COUNTY
AT THIS TIME. THE AFOREMENTIONED ISOLATED SHOWERS/TSTMS WERE
GENERATED ALONG THIS BOUNDARY WHICH EXTENDING FURTHER NWD INTO
CENTRAL AZ.
FORECAST CHALLENGE FOR LATER TODAY IS MAINLY REGARDING SHOWER/TSTM
DEVELOPMENT AND EVENTUAL EVOLUTION. 13/13Z RUC HRRR FAVORS SHOWERS/
TSTMS TO OCCUR ACROSS WRN/CENTRAL PIMA COUNTY AND SRN PINAL COUNTY
THRU 19Z. SHOWERS/TSTMS TO THEN DEVELOP EARLY THIS AFTERNOON ACROSS
THE MOUNTAINS EXTENDING FROM SWRN GRAHAM COUNTY-ERN PIMA COUNTY-
SANTA CRUZ COUNTY.
GIVEN THE VERY DRY NEAR-SURFACE ENVIRONMENT AND STRONG DAYTIME
HEATING...MAIN CONCERN IS WITH REGARD TO STRONG DOWNBURSTS AND AN
INCREASED POTENTIAL FOR DAMAGING WIND GUSTS. HAVE NOTED A DOWNTREND
VIA THE 13/13Z RUC HRRR REGARDING SHOWERS/TSTMS LATER THIS AFTERNOON
INTO THIS EVENING.
AT ANY RATE...HAVE OPTED FOR A SPECIAL 18Z KTWC SOUNDING. FOR NOW...
NO ADJUSTMENTS REGARDING THE INHERITED OFFICIAL FORECASTS FOR THE
REST OF TODAY. THE UPSHOT...ISOLATED-SCATTERED SHOWERS/TSTMS THIS
AFTERNOON GENERALLY FROM TUCSON EWD/SWD...THEN SCATTERED SHOWERS/
TSTMS THIS EVENING EXCEPT IN WRN PIMA COUNTY WHERE PRECIP-FREE
CONDITIONS SHOULD CONTINUE.
ALSO...HEAT ADVISORY IS IN EFFECT FROM 1 PM THIS AFTERNOON TO 6 PM
MST THIS EVENING FOR PIMA COUNTY AND SOUTH CENTRAL PINAL COUNTY.
&&
.PREV DISCUSSION...FOR THE REMAINDER OF THE WEEK...WILL SEE A
GRADUAL INCREASE IN MOISTURE ACROSS SOUTHEAST ARIZONA. TROPICAL
STORM HECTOR NO LONGER WILL BE AN INFLUENCE FOR THE AREA. HOWEVER IT
DID INCREASE MOISTURE OVER THE SOUTHERN PARTS OF THE GULF OF
CALIFORNIA ON SUNDAY. THE GULF REMAINS VERY MOIST WITH PW VALUES
OVER 1.50". WILL SEE MORE THUNDERSTORM COMPLEXES DEVELOP OVER SONORA
MEXICO...SENDING LOW LEVEL OUTFLOWS AND ITS MOISTURE NORTH ACROSS
SOUTHERN ARIZONA AND ALSO PUSHING OUTFLOWS INTO THE GULF WITH
RESULTANT INCREASE IN LOW LEVEL MOISTURE INTO THE LOWER DESERTS.
DIDN`T MAKE MANY CHANGES TO THE INHERITED FORECAST AS IT HAD A VERY
GOOD HANDLE ON THE TRENDS FOR THE WEEK. WILL THERE BE DAILY CHANGES.
SURE...BUT OVERALL THE FORECAST LOOKS JUST FINE.
ALTHOUGH TUESDAY WILL BE A FEW DEGREES COOLER THAN TODAY...IT WILL
STILL BE PRETTY HOT WITH A FEW DAILY RECORD FALLING. THEN LOOK FOR
COOLER TEMPERATURES FOR THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...ISOLD-SCT TSRA/SHRA INTO THIS EVENING THEN A SLIGHT
CHANCE OF -TSRA/-SHRA EAST OF KTUS 06Z-12Z TUESDAY. OTHERWISE...VFR
CONDITIONS AND SURFACE WIND GENERALLY LESS THAN 10 KTS THRU EARLY
TUESDAY MORNING OR 14/12Z. AVIATION DISCUSSION NOT UPDATED FOR
TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM CHANCES WILL GRADUALLY INCREASE THIS
WEEK AS DEEPER MOISTURE RETURNS TO THE AREA. OTHERWISE...EXPECT
NORMAL DIURNAL WIND TRENDS THIS WEEK.
&&
.CLIMATE...THE FORECAST HIGH TODAY FOR THE TUCSON AIRPORT IS 110.
NOT ONLY WILL THIS SET A NEW DAILY RECORD FOR AUGUST 13TH BREAKING
THE OLD RECORD OF 106 DEGREES WHICH OCCURRED IN 1996/1194/1962...IT
WOULD ALSO BE THE FIRST BACK-TO-BACK 109 OR GREATER DURING AUGUST
SINCE 1994 WHEN IT OCCURRED THREE STRAIGHT DAYS (2ND-4TH). ALSO
TODAY WOULD BE 8 STRAIGHT DAYS WITH A HIGH OF 105 OR GREATER IN
TUCSON...WHICH IS TWO DAYS SHY OF THE AUGUST RECORD OF DAYS WHICH
OCCURRED IN 1995 (1ST-10TH).
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY TODAY FROM 1 PM TO 6 PM MST FOR AZZ501-502-504-505.
$$
WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MDT MON AUG 13 2012
.SHORT TERM...
(TONIGHT AND TOMORROW)
...SCATTERED STORMS FOR EVERYONE NEXT 6-9 HOURS OR SO...
CURRENTLY...
WATER VAPOR AT 2 PM SHOWS A HEALTHY DISTURBANCE UP IN WYOMING AND IT
WAS MOVING EAST SOUTHEAST TOWARDS THE REGION. A RATHER LARGE AREA OF
RAIN WAS NOTED OVER THE GENERAL NW SXTNS OF THE STATE OF CO...WITH
QUITE A FEW SHOWER SURROUNDING THIS AREA OF RAIN. A COUPLE OF
VORTICES WERE IMPLIED IN THE RAIN SHIELD (ORIENTATION OF CURVED
RAINSHIELD ON RADAR IMGY)...WITH ONE NW OF LARAMIE AND ANOTHER
ENTERING NW CO.
REST OF TODAY AND INTO TONIGHT...
SHOWERS AND STORMS WILL CONTINUE TO INCREASE IN COVERAGE OVER THE
REGION...AND THERE IS A PRETTY GOOD CHANCE NEARLY ALL OF US WILL SEE
SOME RAIN DURING THE NEXT 9 HOURS OR SO. PRECIP WAS ALREADY
DEVELOPING ON THE PLAINS AS I WRITE (2 PM) AND HRRR FCST THIS TO
EXPAND AND MOVE TO THE EAST-SOUTHEAST. EVEN GFS HAS A LARGE BULLSEYE
OF PRECIP OVER THE FAR SE PLAINS LATER TODAY. AS FOR THE BURN
SCAR...LATEST HI RES GUIDANCE SHOWS THE BEST CHANCE BETWEEN 3 AND 5
PM. LOCALLY HEAVY RAIN COULD OCCUR BUT I AM NOT ALL THAT CONFIDENT
AS IT MAY BE TOO STABLE FOR ANY HEAVIER RAIN OVER THE SCAR...HOWEVER
I AM PRETTY CERTAIN THEY WILL GET MORE PRECIP TODAY. PRECIP OVER THE
REST OF THE MTNS WILL CONTINUE TO BLOSSOM AS THE AFTERNOON
PROGRESSES.
SHOWERS AND STORMS WILL BE ONGOING ACROSS THE PLAINS THIS EVENING.
ACTIVITY OVER THE MTNS WILL STILL BE ONGOING...BUT WILL BE ON A
GRADUAL DOWNWARD TREND AS THE EVENING PROGRESSES. I WOULD EXPECT BY
MID EVENING THE HEAVIEST STORMS WILL BE OVER THE EASTERN
PLAINS...ESPECIALLY THE FAR E PLAINS. A FEW STRONGER STORMS WILL BE
POSSIBLE BUT WILL ONLY BE MARGINALLY SEVERE AT BEST GIVEN THE
LIMITED CAPE/SHEAR FIELDS CURRENTLY IN PLACE.
BY MIDNIGHT...ISOLATED PRECIP MAY BE OVER THE MTNS WITH PRECIP OVER
THE FAR E PLAIN MOVING OUT OF THE STATE.
TOMORROW...
RATHER STABLE AIRMASS WILL LIKELY BE OVER THE PLAINS AND DO NOT
EXPECT ANY PRECIP. THE ONLY EXCEPTION MAY BE THAT PART OF THE PLAINS
ABOVE 6000 FEET WHICH MAY SEE A SHOWER LATE IN THE DAY. THE MTNS
WILL CONTINUE TO SEE SCTD COVERAGE..ESPECIALLY ALONG THE CONTDVD. I
DID KNOCK DOWN TEMPS A FEW DEGREES AS IT WILL LIKELY BE A BIT COOLER
TOMORROW THAN EARLIER ADVERTISED.
.LONG TERM...
(TUESDAY NIGHT THROUGH MONDAY)
TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON...AS THE UPPER WAVE
DEPARTS AND THE RIDGE CONTINUES TO BREAK DOWN...SUBSIDENCE SHOULD
RESTRICT CONVECTION TO THE MTS THROUGH THE EVE...THEN THE TYPICAL
ISOLATED TO LOW SCATTERED CONVECTION FOR THE MTS WED AFTN. A WARM
AND BREEZY DAY IS ON TAP FOR WED...AHEAD OF THE NEXT INCOMING SFC
FRONT.
WEDNESDAY NIGHT THROUGH FRIDAY...MODELS INDICATE A RATHER STRONG
SHORTWAVE DROPS DOWN OUT OF CANADA AND ACROSS THE NORTHERN PLAINS ON
WED...PUSHING A SFC FRONT DOWN INTO COLORADO WED EVE. NAM MODEL
SHOWS A PRE-FRONTAL NORTHERLY PUSH THROUGH THE DAY WED...WITH THE
TRUE SFC FRONT CROSSING THE PALMER DVD RIGHT BETWEEN 00Z AND 06Z.
SO...NORTHERLY WINDS LATE WED NIGHT INTO THU MORNING...WITH WINDS
SWINGING AROUND TO THE EAST BY THU AFTN. PCPN SHOULD BE FAIRLY
WIDESPREAD LATE WED NIGHT AND LINGER INTO THE EARLY MORNING HRS OF
THU...THEN FIRE UP AGAIN QUICKLY ON THU WITH UPSLOPE SHOVING THE
MOISTURE UP AGAINST THE SOUTHERN FRONT RANGE. PCPN WILL TAPPER OFF
FROM N TO S THU EVE...THEN A LITTLE LESS COVERAGE IS THEN FORECAST
FOR FRI. MAX TEMPS ON THU ARE CURRENTLY FORECAST TO WARM INTO THE
70S TO NEAR 80 F FOR THE PLAINS...BUT WITH THE EXPECTED CLOUD COVER
THIS MAY BE SLIGHTLY TOO WARM...AND WILL HAVE TO REVISIT MAX TEMP
GRIDS AGAIN OVER THE NEXT FEW MODEL RUNS. THE COOL TEMPS SHOULD
CARRY OVER INTO FRI AS THE LLVL COOL AIR AND MOISTURE GRADUALLY
ERODES.
SATURDAY THROUGH MONDAY...UPPER RIDGE STRENGTHENS OVER THE WESTERN
US FOR THE WEEKEND...WITH CONVECTIVE ACTIVITY SLIPPING BACK INTO A
DIURNAL PATTERN WITH MORE ISOLATED COVERAGE TIED TO THE HIGHER
TERRAIN. GFS MODEL IS INDICATING A LOT MORE POSSIBLE PCPN OVER THE
PLAINS...WHICH IS LIKELY A RESULT OF THE RIDGE BREAKING DOWN FASTER
THAN WHAT THE ECMWF SHOWS...SO WILL MAINTAIN THE FORECAST OF DIURNAL
MT CONVECTION AND MAX TEMPS CLIMBING BACK INTO THE 90S FOR THE
PLAINS AND 80S FOR THE HIGH VALLEYS. MOORE
&&
.AVIATION...
ALL TAFS SITES WILL SEE STORMS TODAY. A FEW SHOWERS HAVE ALREADY
MOVED ACROSS KALS AND KCOS AS PER RADAR IMGY. WITH THE VORT MAX
MOVING ACROSS THE AREA LATER TODAY AND EARLY THIS EVENING SCATTERED
STORMS WILL MOVE ACROSS THE TAF SITES...WITH THE BEST CHANCE BETWEEN
3 AND 7 PM AT KCOS AND 3 AND 8 PM ACROSS KPUB. SHOWERS WILL MOVE
ACROSS KALS BETWEEN NOW AND 8 PM THIS EVENING. CIGS SHOULD REMAIN
ABOVE MVFR BUT WE MAY SEE BRIEF HVY RAINS WHICH WILL BRING MVFR
CONDITIONS TO THE TAF SITES.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
34/27
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
552 PM EDT MON AUG 13 2012
.UPDATE...
DIFFICULT FORECAST FOR TONIGHT...WITH NONE OF THE MODELS REALLY HAVING
A GOOD HANDLE ON THE CURRENT SHOWER AND THUNDERSTORM ACTIVITY.
HAVE SIGNIFICANTLY UPDATED POPS AND WEATHER GRIDS TO ACCOUNT FOR
CURRENT CONVECTION ASSOCIATED WITH MCS THAT MOVED EASTWARD OUT OF
TN/AL THIS AFTERNOON. LATEST LAPS SHOWING BEST INSTABILITY ALONG
THE GA/AL LINE...WITH AREAS FURTHER EAST FAR MORE STABLE. IN
GENERAL...EXPECT AN OVERALL WEAKENING TREND AS THIS LARGE AREA OF
PRECIPITATION CONTINUES TO MOVE EASTWARD.
WILL BE MAKING PERIODIC UPDATES TO THE FORECAST AS NECESSARY AS
THIS EVENT CONTINUES TO UNFOLD. HAVE GONE AHEAD AND CANCELLED THE
SVR WATCH FOR THE FAR NORTHEAST PORTION OF THE STATE.
31
&&
.PREV DISCUSSION... /ISSUED 308 PM EDT MON AUG 13 2012/
..SEVERE STORMS EXPECTED THROUGH THIS EVENING EXTREME NW GEORGIA...
SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ALL EYES ON MCS OVER TENNESSEE AND ALABAMA WHICH CONTINUES TO MAKE
STEADY PROGRESS TO THE EAST. NOW HAVE A WATCH UP FOR THE EXTREME
NW CORNER OF THE FORECAST AREA WHERE THERE IS IRONICALLY LITTLE TO
NO INSTABILITY AT THIS TIME. SYSTEM HAS HOWEVER BEEN ABLE TO BRING
ALONG ITS OWN ENHANCED MOISTURE AND INSTABILITY ALTHOUGH ITS
ABILITY TO DO SO AS IT APPROACHES THE FORECAST AREA REMAINS IN
QUESTION. RAP SHORT TERM GUIDANCE DOES SHOW INCREASED INSTABILITY
WITHIN THE NEXT 2 HOURS PUSHING INTO THE NW ZONES BUT ONLY ON THE
ORDER OF 1500 TO 2000 J/KG...MUCH LESS THAN UPSTREAM VALUES WE HAVE
SEEN. SO IN SHORT...EXPECTING SVR POTENTIAL TO INCREASE FOR THE
EXTREME NW AND WESTERN TIER OVER THE NEXT SEVERAL HOURS BUT TRENDS
IN INSTABILITY SUGGEST A LIMITED TIMEFRAME FOR CONVECTIVE
POTENTIAL. ALSO WATCHING DEVELOPING AREA OF DCAPE IN EXCESS OF
1000 J/KG WHICH COULD ALLOW FOR ISOLATED SVR OUTSIDE OF CURRENT
WATCH AREA FROM COLUMBUS UP TO LA GRANGE.
QUESTIONS ALSO SURROUND HOW FAR ACTUAL LINE OF SHOWERS AND STORMS
MAKES IT TO THE EAST. AS MENTIONED...EXPECTING A SHARP INSTABILITY
GRADIENT AND MOMENTUM LOOKS TO ONLY TAKE THIS SYSTEM SO FAR. HRRR
IS DIMINISHING LINE AND THEN GENERATES NEW CONVECTION ALONG ACTUAL
FRONT INTO THE OVERNIGHT HOURS. GIVEN CURRENT TRENDS...WILL EXPAND
POP COVERAGE SLIGHTLY EASTWARD BUT ONLY CARRY LOW END CHANCE POPS
INTO THE OVERNIGHT PERIOD FOR THE ATLANTA METRO AND POINTS NORTH
AND WEST.
BY 12Z...FRONT WILL SAG INTO NORTH GEORGIA WITH DRIER AIR
BEGINNING TO FILTER IN. WILL BE IN LARGE SCALE TROUGH PATTERN BUT
NO NOTABLE SHORTWAVES EMBEDDED IN FLOW UNTIL 00Z. THIS COULD
ENHANCE POPS FIELD BUT PRIMARILY OVER THE SOUTHERN TIER WHERE I
HAVE INCLUDED LIKELY POPS.
DEESE
LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO SIGNIFICANT CHANGES PLANNED.
BDL
MEDIUM RANGE MODELS REMAIN CONSISTENT THROUGH THE EXTENDED
FORECAST PERIOD KEEPING THE EASTERN U.S. UNDER PERSISTENT LONG
WAVE TROUGHING. ALTHOUGH THE LARGE SCALE PATTERN REMAINS FAIRLY
STATIC...THE SMALLER SCALE REMAINS QUITE ACTIVE AS SHORT WAVES
SWING THROUGH THE TROUGH DIGGING OUT OF THE NORTHERN PLAINS INTO
THE OHIO VALLEY. THIS PATTERN KEEPS THE BEST UPPER DYNAMICS NORTH
OF THE REGION...BUT MANAGES TO DRIVE A SERIES OF ASSOCIATED
SURFACE FRONTS THROUGH THE STATE. FIRST SYSTEM IS EXITING AS WE
HEAD INTO THE EXTENDED PERIOD SO ANOTHER SHOT OF MILDER AND FAIRLY
DRY AIR SETTLES IN FOR THE MIDDLE OF THE WEEK. NEXT SYSTEM IS
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. THIS
CORRESPONDS WELL WITH PREVIOUS MODEL RUNS SO THERE ARE NO
SIGNIFICANT CHANGES TO THE PREVIOUS EXTENDED FORECAST THEMES.
20
AVIATION...
18Z UPDATE...
CONTINUING TO WATCH THE ADVANCEMENT OF SQUALL LINE THROUGH
NORTHERN AND CENTRAL ALABAMA WITH NO WEAKENING TREND AS OF YET.
DESPITE THIS...ALL GUIDANCE INDICATES IT WILL BEGIN TO DISSIPATE
BY THE TIME IT REACHES THE AL/GA LINE WITH JUST RESIDUAL SHRA FOR
ATL AND SURROUNDING TERMINALS THROUGH THE OVERNIGHT PERIOD. MUCH
UNCERTAINTY EXISTS WITH THIS ASPECT OF THE FORECAST HOWEVER AND
CHANGES WILL BE HANDLED WITH SUBSEQUENT AMENDMENTS. DO EXPECT LINE
OF TSRA TO DEVELOP ONCE AGAIN MID MORNING ON TUESDAY AND HAVE
INCLUDED PROB30 THROUGH THE EARLY AFTERNOON HOURS.
//ATL CONFIDENCE...18Z UPDATE...
LOW ON CONVECTION POTENTIAL THIS EVENING.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 90 69 91 / 20 40 20 10
ATLANTA 70 87 71 88 / 60 30 20 10
BLAIRSVILLE 63 83 64 85 / 50 30 20 5
CARTERSVILLE 67 87 68 89 / 70 30 20 5
COLUMBUS 71 90 74 91 / 60 40 20 20
GAINESVILLE 67 87 69 88 / 50 30 20 10
MACON 67 91 72 91 / 20 50 30 20
ROME 67 87 68 89 / 50 30 20 5
PEACHTREE CITY 67 87 69 89 / 60 30 20 10
VIDALIA 70 92 75 92 / 10 60 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...41
LONG TERM....31
AVIATION...41
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
308 PM EDT MON AUG 13 2012
...SEVERE STORMS EXPECTED THROUGH THIS EVENING EXTREME NW GEORGIA...
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
ALL EYES ON MCS OVER TENNESSEE AND ALABAMA WHICH CONTINUES TO MAKE
STEADY PROGRESS TO THE EAST. NOW HAVE A WATCH UP FOR THE EXTREME
NW CORNER OF THE FORECAST AREA WHERE THERE IS IRONICALLY LITTLE TO
NO INSTABILITY AT THIS TIME. SYSTEM HAS HOWEVER BEEN ABLE TO BRING
ALONG ITS OWN ENHANCED MOISTURE AND INSTABILITY ALTHOUGH ITS
ABILITY TO DO SO AS IT APPROACHES THE FORECAST AREA REMAINS IN
QUESTION. RAP SHORT TERM GUIDANCE DOES SHOW INCREASED INSTABILITY
WITHIN THE NEXT 2 HOURS PUSHING INTO THE NW ZONES BUT ONLY ON THE
ORDER OF 1500 TO 2000 J/KG...MUCH LESS THAN UPSTREAM VALUES WE HAVE
SEEN. SO IN SHORT...EXPECTING SVR POTENTIAL TO INCREASE FOR THE
EXTREME NW AND WESTERN TIER OVER THE NEXT SEVERAL HOURS BUT TRENDS
IN INSTABILITY SUGGEST A LIMITED TIMEFRAME FOR CONVECTIVE
POTENTIAL. ALSO WATCHING DEVELOPING AREA OF DCAPE IN EXCESS OF
1000 J/KG WHICH COULD ALLOW FOR ISOLATED SVR OUTSIDE OF CURRENT
WATCH AREA FROM COLUMBUS UP TO LA GRANGE.
QUESTIONS ALSO SURROUND HOW FAR ACTUAL LINE OF SHOWERS AND STORMS
MAKES IT TO THE EAST. AS MENTIONED...EXPECTING A SHARP INSTABILITY
GRADIENT AND MOMENTUM LOOKS TO ONLY TAKE THIS SYSTEM SO FAR. HRRR
IS DIMINISHING LINE AND THEN GENERATES NEW CONVECTION ALONG ACTUAL
FRONT INTO THE OVERNIGHT HOURS. GIVEN CURRENT TRENDS...WILL EXPAND
POP COVERAGE SLIGHTLY EASTWARD BUT ONLY CARRY LOW END CHANCE POPS
INTO THE OVERNIGHT PERIOD FOR THE ATLANTA METRO AND POINTS NORTH
AND WEST.
BY 12Z...FRONT WILL SAG INTO NORTH GEORGIA WITH DRIER AIR
BEGINNING TO FILTER IN. WILL BE IN LARGE SCALE TROUGH PATTERN BUT
NO NOTABLE SHORTWAVES EMBEDDED IN FLOW UNTIL 00Z. THIS COULD
ENHANCE POPS FIELD BUT PRIMARILY OVER THE SOUTHERN TIER WHERE I
HAVE INCLUDED LIKELY POPS.
DEESE
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
NO SIGNIFICANT CHANGES PLANNED.
BDL
MEDIUM RANGE MODELS REMAIN CONSISTENT THROUGH THE EXTENDED
FORECAST PERIOD KEEPING THE EASTERN U.S. UNDER PERSISTENT LONG
WAVE TROUGHING. ALTHOUGH THE LARGE SCALE PATTERN REMAINS FAIRLY
STATIC...THE SMALLER SCALE REMAINS QUITE ACTIVE AS SHORT WAVES
SWING THROUGH THE TROUGH DIGGING OUT OF THE NORTHERN PLAINS INTO
THE OHIO VALLEY. THIS PATTERN KEEPS THE BEST UPPER DYNAMICS NORTH
OF THE REGION...BUT MANAGES TO DRIVE A SERIES OF ASSOCIATED
SURFACE FRONTS THROUGH THE STATE. FIRST SYSTEM IS EXITING AS WE
HEAD INTO THE EXTENDED PERIOD SO ANOTHER SHOT OF MILDER AND FAIRLY
DRY AIR SETTLES IN FOR THE MIDDLE OF THE WEEK. NEXT SYSTEM IS
EXPECTED FOR THE END OF THE WEEK INTO THE WEEKEND. THIS
CORRESPONDS WELL WITH PREVIOUS MODEL RUNS SO THERE ARE NO
SIGNIFICANT CHANGES TO THE PREVIOUS EXTENDED FORECAST THEMES.
20
&&
.AVIATION...
18Z UPDATE...
CONTINUING TO WATCH THE ADVANCEMENT OF SQUALL LINE THROUGH
NORTHERN AND CENTRAL ALABAMA WITH NO WEAKENING TREND AS OF YET.
DESPITE THIS...ALL GUIDANCE INDICATES IT WILL BEGIN TO DISSIPATE
BY THE TIME IT REACHES THE AL/GA LINE WITH JUST RESIDUAL SHRA FOR
ATL AND SURROUNDING TERMINALS THROUGH THE OVERNIGHT PERIOD. MUCH
UNCERTAINTY EXISTS WITH THIS ASPECT OF THE FORECAST HOWEVER AND
CHANGES WILL BE HANDLED WITH SUBSEQUENT AMENDMENTS. DO EXPECT LINE
OF TSRA TO DEVELOP ONCE AGAIN MID MORNING ON TUESDAY AND HAVE
INCLUDED PROB30 THROUGH THE EARLY AFTERNOON HOURS.
//ATL CONFIDENCE...18Z UPDATE...
LOW ON CONVECTION POTENTIAL THIS EVENING.
HIGH ON REMAINING ELEMENTS.
DEESE
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 65 90 69 91 / 20 40 20 10
ATLANTA 70 87 71 88 / 30 30 20 10
BLAIRSVILLE 63 83 64 85 / 30 30 20 5
CARTERSVILLE 67 87 68 89 / 30 30 20 5
COLUMBUS 71 90 74 91 / 40 40 20 20
GAINESVILLE 67 87 69 88 / 30 30 20 10
MACON 67 91 72 91 / 20 50 30 20
ROME 67 87 68 89 / 60 20 20 5
PEACHTREE CITY 67 87 69 89 / 30 30 20 10
VIDALIA 70 92 75 92 / 10 60 50 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
SEVERE THUNDERSTORM WATCH UNTIL 9 PM EDT THIS EVENING FOR THE
FOLLOWING ZONES: CATOOSA...CHATTOOGA...DADE...FLOYD...WALKER.
&&
$$
SHORT TERM...DEESE
LONG TERM....BDL
AVIATION...DEESE
AREA FORECAST DISCUSSION
NWS PADUCAH KY
529 PM CDT MON AUG 13 2012
.UPDATE...
ISSUED AT 529 PM CDT MON AUG 13 2012
FROM A MESOSCALE PERSPECTIVE...THE CURRENT CONVECTION REMAINS IN A
QUASI-STEADY STATE. THE BEST THETA-E CONVERGENCE VIA LAPS DATA IS
BEING FOCUSED IN A ROUGHLY A 25 NAUTICAL MILE WIDE BAND ALONG THE
SURFACE FRONT...BUT WEST OF THE NORTH/SOUTH ORIENTED 2300 J2/K2
CAPE MAXIMUM ORIENTED NEAR INTERSTATE 55 IN SOUTHWEST ILLINOIS AND
SOUTHEAST MISSOURI. THE MAIN SURFACE LOW /WAVE/ IS OVER JACKSON
COUNTY ILLINOIS...AND WILL LIKELY MOVE NEAR MOUNT VERNON IN THE
NEXT COUPLE OF HOURS. UNFORTUNATELY...THE CORE OF THE HIGHER CAPE
VALUES HAS NOT BEEN PROGRESSING FURTHER NORTH...WHICH MAY LIMIT
UNCONDITIONAL SURFACE BASED INSTABILITY THROUGH THE EVENING.
THE HRRR AND 12KM NAM GUIDANCE APPEAR TO A HAVE A GENERAL IDEA OF
THE PROGRESSION OF THE FRONT AND OVERALL SYSTEM...BUT THE
PROJECTED FORECAST REFLECTIVITY GRIDS ARE ABOUT 80 TO 100 NM TOO
FAR TO THE SOUTHWEST. THE TIMING FOR SURFACE BASED CONVECTION WILL
BECOME MORE LIMITED THROUGH 00Z TUESDAY /7 PM CDT/ TONIGHT.
THERE IS A SUGGESTION IN THE 12KM NAM-WRF GUIDANCE THAT ENOUGH
FORECAST SHEAR /30-40KTS BULK SHEAR IN THE ZERO TO SIX KILOMETER
LAYER/ MOVING UP FROM EAST OF THE MISSISSIPPI RIVER IN WEST
TENNESSEE BETWEEN 23Z AND 02Z...THAT SOME MORE STORM DEVELOPMENT
AND ORGANIZATION MAY OCCUR TO SUSTAIN UPDRAFTS AS WEAK LOW LEVEL
WIND TRY TO INCREASE AT OR ABOVE THE DEVELOPING BOUNDARY LAYER
INVERSION AHEAD OF THE COLD FRONT. LOW LEVEL SHEAR IS QUITE
WEAK...SO ANY SUPPORT FOR RENEWED CONVECTION INTO WESTERN KENTUCKY
WILL HAVE TO COME FROM MID/UPPER LEVEL FORCING AND INSTABILITY.
THE KNQA VAD WIND PROFILE HAS BEEN SHOWING SOME INCREASE IN WINDS
NEAR 20KFT AS THE BASE OF THE UPPER WAVE. WHETHER THAT WILL BE
ENOUGH AS THE SHORTWAVE MOVES ACROSS WESTERN KY WILL BE THE 20
THOUSAND DOLLAR QUESTION.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 124 PM CDT MON AUG 13 2012
BOUNDARY AT 18Z WAS STILL OVER SOUTHEAST MISSOURI. AIRMASS
CONTINUES TO DESTABILIZE...WITH SOME ENHANCED CU SEEN NW OF
KCGI UP TOWARD PERRYVILLE MO. WILL CONTINUE TO MONITOR THIS
CORRIDOR AND POINTS EAST THROUGH THE AFTERNOON AND EARLY
EVENING FOR A FEW STRONG TO POSSIBLY SEVERE STORMS. OTHERWISE
THE ACTIVITY WILL PUSH EAST TONIGHT. QUIET WEATHER EXPECTED
TUESDAY AND TUESDAY NIGHT WITH VERY WEAK HIGH PRESSURE
FORECAST TO BUILD INTO THE AREA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 124 PM CDT MON AUG 13 2012
BY WEDNESDAY...UPPER HEIGHTS BEGIN TO RISE ACROSS THE AREA AND THIS
SHOULD RESULT IN WARMER TEMPERATURES...BUT WE SHOULD REMAIN RIGHT
AROUND NORMAL. THE SFC HIGH THAT WILL BE OVER THE AREA ON WEDNESDAY
WILL CONTINUE PROGRESSING TO THE EAST AND BY WEDNESDAY NIGHT...OUR
AREA SHOULD BE IN SOUTHERLY FLOW...WITH A WARM FRONT DEVELOPING TO
OUR SOUTH THAT WILL INCH SLOWLY TO THE NORTH. HOWEVER...WE WILL
REMAIN DRY WEDNESDAY NIGHT.
BY 12Z THURSDAY...A COLD FRONT WILL STRETCH FROM THE GREAT LAKES TO
WEST TEXAS...AND BE MOVING EASTWARD ACROSS OUR AREA WITH TIME. BOTH
THE GFS AND ECMWF HAVE BEEN IN REALLY GOOD AGREEMENT WITH THE
PROGRESSION OF THIS FRONT. HOWEVER...THE GFS/ECMWF HAVE DEFINITELY
SLOWED DOWN EVEN MORE WITH THE ONSET OF PRECIP...AND ACTUALLY
INDICATE THAT MOST OF THURSDAY MIGHT END UP BEING FAIRLY DRY...WITH
OUR WESTERN SECTIONS HAVING THE BEST CHANCES BY LATER IN THE
AFTERNOON. THIS WILL MEAN THAT WE WILL PROBABLY SEE WARMER HIGHS ON
THURSDAY AS WELL. WITH HIGHS IN THE UPPER 80S/LOWER 90S AND
DEWPOINTS IN THE UPPER 60S/LOWER 70S...IT WILL DEFINITELY FEEL LIKE
SUMMER IS BACK. SO...WILL KEEP WITH MIDNIGHT SHIFTS THOUGHT OF
BREAKING THE THURSDAY TIME PERIOD INTO TWO...SHOWING BETTER CHANCES
DURING THE AFTERNOON. THE BULK OF THE RAIN WILL ARRIVE ON THURSDAY
NIGHT AS THE FRONT PASSES THROUGH...SO WILL CONTINUE WITH LIKELY
POPS.
BY 12Z FRIDAY...BOTH THE GFS/ECMWF/GEM HAVE THE FRONTAL BOUNDARY IN
OUR EASTERN COUNTIES OR JUST EAST OF THE AREA. BELIEVE WE WILL SEE
THE POSSIBILITY OF PRECIPITATION LINGERING FRIDAY MORNING MAINLY IN
THE SOUTHEASTERN HALF OF THE CWA. COULD ALMOST GO DRY FOR FRIDAY
AFTERNOON...BUT WITH THE MODELS TRENDING SLOWER WITH THIS
FRONT...WILL FORGO THAT FOR NOW.
FRIDAY NIGHT APPEARS DRY ATTM...AS HIGH PRESSURE BUILDS INTO THE
AREA FROM CANADA. MUCH COOLER TEMPERATURES SHOULD RESULT AS 850 MB
TEMPS DIVE INTO THE LOW TEENS BY SATURDAY. THIS SHOULD RESULT IN
TEMPERATURES THAT ARE WELL BELOW NORMAL. GIVEN THE VERY DRY AIR THAT
WILL LIKELY FILTER INTO THE REGION...HIGH TEMPERATURES WILL PROBABLY
END UP BEING HIGHER THAN WHAT THE CURRENT GUIDANCE NUMBERS ARE
SUGGESTING. THE GFS AND ECMWF INDICATE AN INCREASE IN
MOISTURE/PRECIPITATION AS EARLY AS SATURDAY NIGHT AND INTO
SUNDAY...AS SOME ENERGY WRAPS AROUND AN UPPER LOW IN EASTERN CANADA
AND DIVES DOWN INTO OUR AREA. THE ECMWF APPEARS TO BE FASTER AND A
LITTLE MORE GUNG HO ON THIS IDEA...SHOWING A MORE PRONOUNCED TROUGH
SWINGING THROUGH. WITH CURRENT MODEL DIFFERENCES...WILL LEAVE THINGS
DRY FOR THE WEEKEND AND MONDAY...UNTIL WE CAN OBTAIN SOME BETTER
CONSISTENCY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 529 PM CDT MON AUG 13 2012
MAIN CHALLENGE WITH THE 00Z TUESDAY TAF ISSUANCE WILL BE THE
TIMING AND EXTENT OF THE CONVECTION /SHOWERS AND THUNDERSTORMS/
OVER THE KPAH/KEVV/KOWB TAF SITES THIS EVENING. AT THIS
TIME...PLAN TO UTILIZED MVFR CEILINGS AND VISIBILITIES WITH ANY
EXPECTED STORMS AHEAD OF THE FRONT...WITH VFR CEILINGS OR CLOUD
BASES FOLLOWING FRONTAL PASSAGE. THERE WILL BE A SIX TO EIGHT HOUR
PERIOD OF SCATTERED CLOUDS /NO CEILINGS/ A FEW HOURS AFTER THE
COLD FRONTAL PASSAGE. PLAN TO REINTRODUCE VFR CEILINGS FOR
KCGI/KPAH WITH THE DIURNAL STRATOCUMULUS IN THE 11Z-13Z TUESDAY
TIME FRAME...WITH LATE MORNING /15Z OR LATER/ VFR AT KEVV/KOWB.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...SMITH
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
416 PM EDT MON AUG 13 2012
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 407 PM EDT MON AUG 13 2012
WV LOOP AND RAOBS INDICATE UPPER TROUGHS FROM NORTHERN ONTARIO
THROUGH THE WESTERN GREAT LAKES REGION. STRONGEST SHORTWAVES IN
THE MEAN TROUGH ARE OVER NORTHERN ONTARIO AND ALSO SOUTHERN LOWER
MICHIGAN. SHORTWAVE BTWN THE TWO TROUGHS AND SFC TROUGH MERGED UP
WITH LAKE BREEZES OVR CNTRL UPR MICHIGAN EARLIER THIS AFTN TO KICK
OFF ISOLD SHRA AND STORMS. CONVECTIVE DEPTH WAS SHALLOW...BUT RADAR
ESTIMATED PRECIP AMOUNTS UP TO 1-1.5 INCHES SEEMED REASONABLE AS
STORM MOTION WAS SLOW AND EVEN TRIED TO BACKBUILD OVR EXTREME
SOUTH CENTRAL MARQUETTE COUNTY AS ONE STORM BRIEFLY BECAME A RIGHT
MOVER.
AS OF 19Z...THE MESS OF THE SYNOPTIC TROUGH AND LAKE BREEZE
CONVERGENCE BOUNDARY IS ORIENTED FM ROUGHLY WATERSMEET THROUGH JUST
NORTH OF CRYSTAL FALLS AND IRON MOUNTAIN AND EAST TOWARD NEWBERRY
AND SAULT STE MARIE. ISOLD-SCATTERED SHRA/TSRA ARE LOCATED ALONG THE
TROUGH WITH STORM MOTIONS GENERALLY ESE AROUND 15 MPH. BASED ON
RADAR TRENDS AND HRRR MODEL...HIGHLIGHTED HIGHEST POPS EARLY THIS
EVENING OVR SCNTRL UPR MICHIGAN...WITH DIMINISHING TREND BY LATE
EVENING DUE TO LOSS OF DAYTIME INSTABILITY AND LOW-LEVEL
CONVERGENCE. STILL...AT LEAST ISOLD SHRA/TSRA MAY TRY TO STICK
AROUND THROUGH EVEN AFTER MIDNIGHT IN THE FAR SCNTRL WITH LINGERING
WEAKER SHORTWAVE ENERGY OVERHEAD AND STEEPER MID-LEVEL LAPSE RATES
AND H85-H7 MOISTURE. ALL CONVECTION SHOULD BE OUT OF CWA BY LATE
TONIGHT. TEMPS OVER INTERIOR WEST MAY TRY TO FALL OFF INTO THE 40S
LATE TONIGHT WITH A LOWER PWAT MIN LOCATED THERE. A BIT OF WIND AND
POSSIBLE SCT-BKN MID CLOUDS SHOULD KEEP REST OF CWA IN THE 50S.
ON TUESDAY...DAY STARTS OFF WITH THE SCT-BKN MID CLOUDS WITH CU
BUILDUP BY LATE MORNING AS CONVECTIVE TEMPS ARE IN THE LOWER 70S.
SHORTWAVE ON BACK SIDE OF LARGER SCALE TROUGH IN CNTRL SASKATCHEWAN
AND/OR MANITOBA FCST TO SLIDE INTO CNTRL CWA BY MID AFTN. GIVEN
SIMILAR FCST SBCAPES IN THE 700-1000J/KG RANGE COULD SEE REPEAT
PERFORMANCE OF TODAY...OR AT LEAST SOMEWHAT SIMILAR...WITH
ISOLD-SCATTERED SHRA/TSRA FORMING SHORTLY AFTER CONVECTIVE TEMPS
ARE REACHED. MAIN DIFFERENCE IS THE SHORTWAVE IS NOT AS STRONG AND
LOW-LEVEL CONVERGENCE WILL BE STRICTLY DRIVEN BY LAKE BREEZES FM
LAKE SUPERIOR/LAKE MICHIGAN. MSLP/WIND PATTERN POINTS TO AREA BTWN
SAW-IMT-ESC STAND TO SEE BEST COVERAGE OF SHRA/TSRA. FREEZING LEVELS
AROUND 11KFT AGL AND H85-H7 WINDS FAIRLY SIMILAR TO TODAY AS
WELL...SO AGAIN COULD SEE SLOW MOVING STORMS WITH MAIN HAZARDS
LIGHTNING AND HEAVY DOWNPOURS. SMALL HAIL COULD ALSO OCCUR WITH
STRONGEST STORMS. CONVERGENCE WANES BY LATE AFTN SO KEPT WITH IDEA
THAT POPS WILL BE OUT OF THE CWA BY EARLY TUESDAY EVENING.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 407 PM EDT MON AUG 13 2012
TUESDAY NIGHT THROUGH WEDNESDAY AFTERNOON...THE UPPER LEVEL TROUGH
WITH AXIS EXTENDING SOUTHWARD FROM CENTRAL ONTARIO THROUGH THE
EASTERN HALF OF UPPER MI AND INTO THE WESTERN HALF OF LOWER MI WILL
SHIFT EASTWARD OVERNIGHT...REACHING THE LOWER GREAT LAKES BY
WEDNESDAY AFTERNOON. AS THIS TROUGH SHIFTS EASTWARD A SURFACE AND
WEAK UPPER LEVEL RIDGE WILL BUILD INTO THE UPPER GREAT LAKES
REGION...BRIEFLY BRINGING AND END TO THE CHANCES OF PRECIPITATION.
WEDNESDAY EVENING THROUGH FRIDAY NIGHT...AS THE SURFACE RIDGE AND
UPPER LEVEL RIDGE BEGIN TO SHIFT EASTWARD TO THE LOWER GREAT LAKES
ATTENTION WILL THEN TURN TO AN APPROACHING LOW PRESSURE SYSTEM
CENTERED OVER NORTHERN MN...WITH ASSOCIATED UPPER LEVEL TROUGH TO
THE WEST OF THE SURFACE LOW...INDICATED BY BOTH THE
EC/GFS...SUGGESTING THAT THE SURFACE LOW IS EXPECTED TO INTENSIFY.
THE LOW WILL PASS TO THE NORTH OF THE UPPER PENINSULA BY 12Z
THURSDAY AS IT DRAGS A COLD FRONT THROUGH INTO CENTRAL UPPER MI
AROUND THE SAME TIME AS INDICATED BY PLOTTING MSLP/850 THETA
E/SURFACE WINDS. THE MAIN AREA OF PRECIPITATION WILL LIKELY BE
PEGGED TO THE FRONT OF THE COLD FRONT AS THE FORCING APPEARS THE
GREATEST ALONG THIS AREA AS SHOWN BY PLOTTING 500-300MB DIVQ ALONG
WITH 1000-500 RH VALUES. MU CAPE VALUES AREA PROGGED TO BE AROUND
500-800 J/KG OVER MUCH OF THE AREA OVER THE WESTERN HALF OF THE AREA
AROUND 06Z SHIFTING TO THE EAST HALF AROUND 12Z THURSDAY. 0-6 KM
SHEAR VALUES ARE EXPECTED TO BE AROUND 30 TO 35 KNOTS AHEAD OF THE
FRONT WITH VALUES INCREASING TO AROUND 50 KNOTS ALONG AND BEHIND THE
FRONT. SHEAR VALUES BEING MARGINAL FOR SEVERE WEATHER AHEAD OF THE
FRONT ALONG WITH CAPE IN THE HAIL GROWTH ZONE AROUND 100-200 J/KG
WOULD INDICATE ONLY A MARGINAL THREAT OF HAIL. DCAPE VALUES ARE
FAIRLY LOW WITH VALUES AROUND 100-150 J/KG DUE TO A LACK OF DRY AIR
IN THE MID LEVEL. THURSDAY NIGHT THROUGH FRIDAY NIGHT THE UPPER
LEVEL TROUGH WILL REMAIN OVER UPPER MI...WHILE SHIFTING EVER SO
SLOWLY TO THE EAST AS THE SURFACE LOW PULLS OT THE NORTHEAST TO
WESTERN QUEBEC. THE COOLER AIR WRAPPING AROUND THE BACK SIDE OF THE
LOW ALONG WITH DECREASED TEMPERATURES ALOFT...AROUND 4 TO 6C AT
H850...WILL HELP TO INCREASE THE CHANCE OF LAKE EFFECT SHOWERS OVER
THOSE AREAS FAVORED BY NORTH WINDS. HAVE ALSO INCREASED THE WINDS
OVER THE CENTRAL AND EASTERN PORTIONS OF THE LAKE AS CAA KICKS
IN...EXPECT THE STRONGER WINDS TO MIX DOWN AS H850 WINDS ARE AROUND
35 KNOTS. WILL HAVE TO KEEP AN EYE ON THIS THROUGH LATER SHIFTS.
SATURDAY THROUGH MONDAY...BOTH THE EC AND GFS KEEP THE UPPER LEVEL
500MB TROUGH SITUATED OVER MUCH OF THE UPPER GREAT LAKES
REGION...HELPING TO KEEP ON AND OFF CHANCES OF SHOWERS IN THE
FORECAST THROUGH MONDAY AFTERNOON. THE BEST CHANCE OF RAIN SHOWERS
THROUGH THIS PERIOD WOULD BE MONDAY AS A SURFACE LOW APPROACHES THE
AREA FROM THE WEST. MOISTURE THROUGH THIS TIME PERIOD APPEARS TO BE
FAIRLY LIMITED AS A SURFACE HIGH WILL REMAIN JUST TO THE SOUTH OF
THE REGION KEEPING DRY WESTERLY WINDS PUSHING INTO THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 225 PM EDT MON AUG 13 2012
WEAK COLD FRONT COULD TRIGGER ADDITIONAL SHRA/TSRA AT SAW THIS
AFTERNOON. IWD AND CMX SHOULD REMAIN DRY. IFR/MVFR CONDITIONS WITH
THE SHRA/TSRA EARLY THIS AFTN AT SAW...BUT OTHERWISE SHOULD BE VFR
AT ALL THE TAF SITES. ONCE FRONT MOVES THROUGH LATER TODAY...EXPECT
SCT-BKN MID CLOUDS AT ALL TAF SITES TONIGHT INTO TUESDAY MORNING
WITH OVERALL LIGHT WINDS. IF SKIES CAN CLEAR OUT SOME TONIGHT MAY
SEE PATCHY FOG FORM AT SAW DUE TO THE ADDITIONAL MOISTURE FROM
SHRA/TSRA THAT OCCURRED EARLY THIS AFTN. SHOT AT ISOLATED SHRA ON
TUESDAY AT SAW BUT THIS WOULD BE AFTER THIS TAF PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EDT MON AUG 13 2012
QUIET MARINE WEATHER THROUGH WEDNESDAY AS HIGH PRESSURE SLIDES
OVERHEAD. BY LATER THURSDAY...PASSAGE OF A STRONG COLD FRONT WILL
KICK UP NORTHWEST WINDS TO 25 KTS OVER MUCH OF THE LAKE. WINDS TO 30
KTS ARE EXPECTED OVER CENTRAL AND EASTERN SECTIONS AS COLDER AIRMASS
PUSHES ACROSS THE STILL WARMER WATERS OF LAKE SUPERIOR. THE UNSTABLE
PROFILE WILL LEAD TO BUILDING WAVES THURSDAY NIGHT INTO FRIDAY.
EXPECT THE STRONG WINDS AND HIGH WAVES TO CONTINUE INTO SATURDAY
BEFORE DIMINISHING WITH ARRIVAL OF HIGH PRESSURE. EXPECT THE HIGHER
WAVES TO LEAD TO AN INCREASED RISK OF RIP CURRENTS LATE THURSDAY
THROUGH FRIDAY ALONG THE BEACHES OF EASTERN LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...KEC
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
331 PM EDT MON AUG 13 2012
.SYNOPSIS...
ISSUED AT 311 PM EDT MON AUG 13 2012
RAIN SHOWERS WILL CONTINUE INTO TONIGHT AS LOW PRESSURE MOVES
SOUTH OF LOWER MICHIGAN. FAIR WEATHER WILL FOLLOW FOR TUESDAY AND
WEDNESDAY BUT STRONG THUNDERSTORMS ARE POSSIBLE THURSDAY NIGHT AS
A COLD FRONT MOVES THROUGH.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 311 PM EDT MON AUG 13 2012
LOWERED POPS A BIT TONIGHT AND TUESDAY MORNING. DROPPED POPS FOR
TUESDAY AFTERNOON AND WEDNESDAY NIGHT.
RADAR TRENDS AND HRRR INDICATE THAT MOST OF THE SHOWERS WILL BE
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA WITH MORE SCATTERED
RAIN SHOWERS ACROSS THE NORTH. ADJUSTED POPS TO REFLECT THIS AND
ADDED AREAS OF FOG AFTER MIDNIGHT GIVEN THE EXPECTED LIGHT WINDS
AND HIGH LOW LEVEL RH. LEFT THUNDER OUT OF THE FORECAST DUE TO
MARGINAL INSTABILITY BUT CANNOT RULE OUT AN ISOLATED THUNDERSTORM.
NAM AND GFS CROSS SECTIONS SHOW A QUICKER DEPARTURE OF THE DEEPER
RH ON TUESDAY...SO TRIMMED POPS FOR THE MORNING AND DROPPED THEM
FOR THE AFTERNOON FOR ALL ZONES.
WEAK SFC RIDGING MOVES IN FOR TUESDAY NIGHT AND WEDNESDAY BUT
UPPER TROUGH AMPLIFICATION WILL LEAD TO STRONG SFC COLD FRONT
MOVING TOWARDS LOWER MICHIGAN WEDNESDAY NIGHT. AT HIS POINT IT
APPEARS THE ST ROMS ALONG THE FRONT WILL HOLD OFF UNTIL LATER
THURSDAY...SO DROPPED POPS FOR WEDNESDAY NIGHT.
.LONG TERM...(THURSDAY THROUGH MONDAY)
ISSUED AT 311 PM EDT MON AUG 13 2012
MAIN FOCUS OF THE FCST CONTINUES TO BE THE STRONG FRONT EXPECTED TO
MOVE THROUGH THU/THU NIGHT. THE WEEKEND LOOKS COOL AND POTENTIALLY A
LITTLE UNSETTLED WITH TROUGHING HANGING OUT OVER THE REGION. NO REAL
CHANGES WERE MADE TO THE FCST.
PCPN CHANCES WILL BE GRADUALLY INCREASING AT THE BEGINNING OF THE
LONG TERM PERIOD ON THU. THIS OCCURS AS UPPER RIDGING MOVES EAST OF
THE AREA...AND THE STRONG UPPER SYSTEM CURRENTLY MOVING INTO NW
BRITISH COLUMBIA DIGS INTO THE REGION. MODELS CONTINUE TO INDICATE
THAT MOST OF THE PCPN WITH THE SFC FRONT WILL BE RIGHT ALONG AND
JUST BEHIND THE FRONT. THIS IS WHERE THE TAIL END OF THE UPPER
TROUGH AND SFC FRONT OVERLAP.
IT CONTINUES TO LOOK LIKE CLOUDS OUT AHEAD OF THE FRONT WILL
SUPPRESS DIURNAL INSTABILITY SOME. MODELS INDICATE THAT AT LEAST A
FEW HUNDRED J/KG OF ML CAPE WILL BE LIKELY...AND THE GFS /LIKELY
OVERDONE DUE TO SFC DEW POINTS/ SHOWS MORE POTENTIAL INSTABILITY.
DEEP LAYER SHEAR STILL LOOKS TO BE MARGINAL ALONG THE FRONT...WITH
MUCH BETTER VALUES POST-FRONTAL. WE STILL EXPECT THAT STRONG STORMS
WILL BE POSSIBLE DUE TO THE STRENGTH OF THE FRONT AND UPPER TROUGH
THAT COULD COMPENSATE FOR MARGINAL SHEAR AND INSTABILITY.
ONCE THE UPPER TROUGH SUPPORTING THE FRONT MOVES IN...IT LOOKS TO
BECOME ESTABLISHED OVER THE AREA THROUGH THE REMAINDER OF THE
PERIOD. WE WILL SEE SHORT WAVE ENERGY CONTINUE TO DIVE INTO THE MEAN
TROUGH OVER THE GREAT LAKES...HELPING TO REINFORCE IT. THIS WILL
KEEP A CHC OF MAINLY DIURNAL SHOWERS AROUND THROUGH NEXT MON. THE
AREA WILL SEE FALL-LIKE TEMPS IN THE 60S AND TO AROUND 70 FOR THE
WEEKEND. TEMPS WILL SLOWLY MODIFY INTO THE 70S BY MON NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 147 PM EDT MON AUG 13 2012
RAIN TRENDS AND FOG/STRATUS POTENTIAL ARE THE MAIN ITEMS OF CONCERN
WITH THIS SET OF FCSTS.
LIGHT RAIN/SHOWERS HAVE BEEN PUSHING THROUGH ALL MORNING LONG.
SOMEWHAT DRY LOW LEVELS HAVE LIMITED THE INTENSITY OF THE RAIN...
ALONG WITH THE CIGS AND VISBYS REMAINING HIGH. MODELS HAVE TRENDED
FURTHER SOUTH WITH THE ENTIRE SYSTEM. NO IT APPEARS BASED ON
UPSTREAM TRENDS IN CONDITIONS THAT ONLY THE I-94 TERMINALS MAY SEE
SOME MVFR CONDITIONS LATER THIS AFTERNOON AND EVENING. RAIN SHOULD
GRADUALLY END LATER THIS EVENING AND OVERNIGHT FROM WNW TO E/SE.
IFR IS LOOKING LIKELY AT MOST SITES LATER TONIGHT. MODELS ARE
INDICATING STRATUS MOVING IN ACROSS KJXN AND KLAN LATER TONIGHT. AT
THE OTHER SITES...THE RAIN AND CLOUDS LOOK TO CLEAR OUT. LIGHT WINDS
AND A MOIST LOW LEVEL ATMOSPHERE WILL LIKELY PRODUCE FOG AT THE
REMAINDER OF THE SITES.
FOG AND STRATUS WILL CLEAR/MIX OUT BY MID TUE MORNING. CUMULUS CAN
BE EXPECTED TO DEVELOP WITH CONTINUED LIGHT WINDS.
&&
.MARINE...
ISSUED AT 311 PM EDT MON AUG 13 2012
SOME FOG IS POSSIBLE ALONG THE COAST WHERE COOLER WATERS HAVE BEEN
STIRRED UP BY LAST WEEKS STORM. OTHERWISE...NO SIGNIFICANT WEATHER
IS EXPECTED UNTIL THURSDAY OR THURSDAY NIGHT WHEN A COLD FRONT
BRINGS THE CHANCE FOR STRONG THUNDERSTORMS.
&&
.HYDROLOGY...
ISSUED AT 311 PM EDT MON AUG 13 2012
RAINS TODAY AND TONIGHT SHOULD NOT AFFECT RIVER LEVELS. SOME
HEAVIER RAINS ARE POSSIBLE THURSDAY AND THURSDAY NIGHT WITH A HALF
TO AN INCH OF BASIN AVERAGE QPF POSSIBLE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
SYNOPSIS...OSTUNO
SHORT TERM...OSTUNO
LONG TERM...NJJ
AVIATION...NJJ
HYDROLOGY...OSTUNO
MARINE...OSTUNO
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
152 PM EDT MON AUG 13 2012
.AVIATION...
//DISCUSSION...
MESOSCALE WAVE IS LIFTING UP THROUGH SE MI AT THE MOMENT LEADING TO
ENHANCEMENT IN THE PRECIP SHIELD OVER THE STATE WHICH IS TIED TO THE
SURFACE LOW TO OUR SOUTH. SOME MODERATE SHOWERS WILL BE POSSIBLE FOR
MBS AND TO A LESSER EXTENT FNT THIS AFTERNOON. POINTS SOUTH WILL BE
MORE OF SCATTERED LIGHT SHOWERS. COVERAGE WILL INCREASE THROUGH THE
LATE EVENING AS AN UPPER LEVEL WAVE MOVES THROUGH THE REGION.
CEILINGS HAVE BEEN FLUCTUATING BETWEEN 3KFT-7KFT BUT IT LOOKS LIKELY
THAT 4500FT WILL BE MOST COMMON AND WILL LOWER THROUGH THE
EVENING/NIGHT. VISIBILITIES WILL DEGRADE OVERNIGHT AS WELL WITH
FOG/HAZE APPEARING TOWARD MORNING AS THE HEAVIER PRECIP WORKS EAST.
FOR DTW...CEILINGS WILL FLUCTUATE AROUND 5000FT THROUGH THE
AFTERNOON BEFORE DROPPING TO MVFR AFTER MIDNIGHT AND POSSIBLY IFR BY
MORNING. RAIN SHOWERS WILL INCREASE IN COVERAGE OVERNIGHT.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE CEILINGS WILL BE BELOW 5000FT AT TIMES THIS
AFTERNOON WITH HIGHER CONFIDENCE OVERNIGHT.
&&
.PREV DISCUSSION...ISSUED 703 AM EDT MON AUG 13 2012
UPDATE...
MORNING SHOWERS HAVE POPPED UP OVER WESTERN MICHIGAN IN
CONJUNCTION WITH A SURGE OF HIGHER THETA E AIR. WHILE MUCH OF THIS
ACTIVITY IS QUICKLY DYING OUT AS IT APPROACHES THE WESTERN
CWA...THE SHOWERS APPROACHING THE SAGINAW VALLEY ARE HOLDING
TOGETHER FAIRLY WELL. THEREFORE WILL RAISE POPS DURING THE MORNING
HOURS GIVEN THE UPTICK IN ACTIVITY THIS MORNING. DESPITE THE
RAISED POPS THESE MORNING SHOWERS WILL BE ISOLATED AND LIGHT IN
NATURE...WITH LITTLE QPF OR A TRACE AMOUNT OF RAIN AS THEY PASS
THROUGH GIVEN THE LOW LEVEL DRY AIR IN PLACE. MAIN EVENT IS STILL
SLATED FOR LATER TODAY AND INTO TONIGHT AS 500 MB SHORTWAVE
EVIDENT ON WATER VAPOR APPROACHES FROM THE WEST.
PREV DISCUSSION...ISSUED 347 AM EDT MON AUG 13 2012
SHORT TERM...TODAY AND TONIGHT
A SURFACE LOW PRESSURE SYSTEM CURRENTLY OVER THE MID-MISSISSIPPI
VALLEY WILL TRACK EAST THROUGH THE NORTHERN OHIO VALLEY TODAY AND
TONIGHT. WHILE THE MODELS HAVE COME INTO BETTER AGREEMENT WITH
REGARDS TO THE TRACK OF THE SURFACE LOW...THERE IS STILL MAJOR
DISAGREEMENT WITH THE TIMING...EXTENT AND QPF AMOUNTS ASSOCIATED
WITH THE PRECIPITATION. THE GFS IS ONCE AGAIN THE POOREST PERFORMER
AS INITIALIZATION HAS WAY TOO MUCH PRECIPITATION IN AN AREA THAT IS
CURRENTLY DRY. WHILE THE NAM IS LESS BROAD BRUSHED WITH ITS QPF...IT
IS TOO SLOW IN PUSHING THE PRECIPITATION EAST AS INITIALIZATION HAS
ABSOLUTELY NO RAIN IN EASTERN ILLINOIS. THE CANADIAN MODEL OFFERS
LITTLE HELP AS IT TRACKS THE LOW THROUGH THE CENTRAL OHIO
VALLEY...THE ONLY MODEL THAT IS THIS FAR SOUTH. THE BEST MODEL
INITIALIZATION IS CURRENTLY THE 3KM HRRR MODEL WHICH UNFORTUNATELY
ONLY GOES OUT THROUGH 18Z WITH THE 03Z MODEL RUN. DESPITE THE TIMING
ISSUES THE NAM SEEMS TO HAVE A GOOD HANDLE ON THE PRECIPITATION
HEADING EAST...AS A GOOD CHUNK OF THE INITIAL SURGE OF RAIN IS
EATEN AWAY THIS AFTERNOON AS THE RAIN RUNS INTO THE ABUNDANT DRY AIR
OVER SOUTHEAST MICHIGAN SHOWN ON THE 00Z KDTX RAOB THANKS TO A DRY
UPPER LEVEL RIDGE CURRENTLY IN PLACE ACROSS THE CENTRAL GREAT LAKES.
DESPITE THE SURGE OF HIGHER THETA E AIR INTO THE AREA THIS AFTERNOON
THE DRY AIR MAY ERODE ENOUGH OF THE RAIN TO WARRANT KEEPING POPS AS
IS WITH THE BEST CHANCES OUT ACROSS THE WESTERN CWA GIVEN THE
SHORTER DISTANCE THE RAIN TRACKS THROUGH THE DRY AIR.
THIS INITIAL SURGE OF MOISTURE SHOULD MOISTEN UP THE ATMOSPHERE BY
THIS EVENING WITH A BETTER CHANCE FOR RAIN AS THE MID LEVEL TROUGH
SWINGS THROUGH THE CENTRAL GREAT LAKES WITH ASSISTANCE FROM UPPER
LEVEL DIVERGENCE ON THE RIGHT REAR OF A WEAK JET STREAK. THE ADDED
DYNAMICS AND MOISTENING UP SHOULD LEND ITSELF TO A PERIOD OF STEADY
RAIN ACROSS SOUTHEAST MICHIGAN TONIGHT...WITH EMBEDDED THUNDERSTORMS
AS MUCAPE VALUES GET TO A FEW HUNDRED J/KG AND SHOWALTERS FALL TO
AROUND ZERO. DESPITE THE PROLONGED PERIOD OF RAIN...QPF AMOUNTS
SHOULD NOT BE EXCESSIVE AS PORTRAYED BY THE NAM GIVEN THE MEAGER
INSTABILITY AND SURFACE LOW WELL TO OUR SOUTH AS DYNAMICS...WHILE
PRESENT...ARE NOT OVERLY IMPRESSIVE.
WITH PRECIPITATION NOT EXPECTED TO MAKE IT INTO THE REGION UNTIL THE
LATE MORNING AND EARLY AFTERNOON...HIGH TEMPERATURES SHOULD BE ABLE
TO GET INTO THE MIDDLE TO UPPER 70S GIVEN THE RELATIVELY WARM START
AFFORDED BY THE OVERNIGHT CLOUD COVER. RAIN AND ABUNDANT CLOUDS
SHOULD KEEP OVERNIGHT LOWS IN THE LOWER TO MIDDLE 60S.
LONG TERM...TUESDAY THROUGH SUNDAY
UPPER TROUGH AXIS AND BACK EDGE OF DEFORMATION WILL SLOWLY PUSH OUT
OF SOUTHEAST MICHIGAN DURING THE MORNING HOURS ON TUESDAY. POTENTIAL
FOR SHOWERS AND THUNDERSTORMS WILL THEREFORE BE HIGHEST IN THE
MORNING...WITH LOWER CHANCES BY AFTERNOON AND EARLY EVENING. CLOUD
COVER SHOULD HELP KEEP MAX TEMPS CONFINED TO THE 70S.
UPPER SHORTWAVE RIDGE WILL THEN CROSS OVER THE AREA TUESDAY NIGHT
AND WEDNESDAY...ALLOWING SURFACE HIGH PRESSURE CENTERED OVER THE
TENNESSEE VALLEY TO EXPAND NORTHWARD INTO THE AREA. DRY WEATHER IS
EXPECTED UNDER THE HIGH...WITH GOOD INSOLATION HELPING TO BOOST
TEMPS BACK INTO THE UPPER 70S TO LOW 80S.
UPPER WAVE ON WATER VAPOR NOW SOUTH OF ALASKA WILL TRACK EAST AND
ACROSS ONTARIO BY EARLY THURSDAY. THE WAVE WILL THEN LIFT NORTH
TOWARDS HUDSON BAY ON FRIDAY AND SATURDAY...FORMING A LARGE UPPER
LOW OVER EASTERN CANADA. THIS WILL KEEP MICHIGAN CONFINED WITHIN A
BROAD UPPER TROUGH THROUGH EARLY NEXT WEEK...WITH MAX TEMPS EXPECTED
TO RUN WELL BELOW NORMAL ON FRIDAY AND THROUGH THE WEEKEND.
A WARM FRONT WILL FIRST LIFT ACROSS LOWER MICHIGAN WEDNESDAY NIGHT
AS SURFACE LOW PRESSURE QUICKLY SPINS UP LEE OF THE ROCKIES AND
BEGINS TO TRACK EAST. NAM SHOWS ISENTROPIC ASCENT WILL INCREASE
OVERNIGHT...BUT SOUNDINGS INDICATE MOISTURE WILL BE LACKING IN THE
LOWER LEVELS TO WORK WITH THE FORCING. WITH LOW-LEVEL DRY AIR
NEEDING TO FIRST BE OVERCOME...THINK PRECIPITATION FOR THE MOST PART
WILL HOLD OFF UNTIL LATE THURSDAY WHEN LOW-LEVEL JET IS FINALLY ABLE
TO PUMP HIGHER MOISTURE UP INTO THE GREAT LAKES (1.75 INCHES PER
GFS)...AND A STRONG COLD FRONT APPROACHES. GFS/EURO/GEM SHOW
PRECIPITATION WILL MAINLY BE TIED TO THE FRONTAL PASSAGE...BUT
EXPECT A FAIRLY BROAD AREA OF RAIN/TSTORMS TO DEVELOP AS GOOD UPPER
DIVERGENCE BECOMES POSITIONED OVER THE FRONT AND FAIRLY HEALTHY
LOW-LEVEL JET FEEDS MOISTURE UP INTO THE AREA. ALSO CANNOT RULE OUT
THE POSSIBILITY OF AN MCS DEVELOPING OVERHEAD...OR MOVING INTO LOWER
MICHIGAN FROM UPSTREAM. SOUTHEAST MICHIGAN LOOKS TO PICK UP ANOTHER
0.25 TO 0.50 INCHES OF RAINFALL FROM THIS SYSTEM BEFORE IT EXITS TO
OUR EAST ON FRIDAY.
MARINE...
QUIET MARINE CONDITIONS WILL BE MAINTAINED THIS MORNING AS A WEAK
RIDGE OF HIGH PRESSURE TRACKS EAST OF THE CENTRAL GREAT LAKES. IN
ITS WAKE A LOW PRESSURE SYSTEM WILL TRACK ACROSS THE SOUTHERN GREAT
LAKES TONIGHT AND TUESDAY. THIS SYSTEM WILL ONCE AGAIN PROVIDE HIGH
CHANCES FOR RAIN AND THUNDERSTORMS DURING IT`S TRANSIT ACROSS THE
AREA. ANOTHER LOW PRESSURE SYSTEM AND ASSOCIATED COLD FRONT WILL
THEN AFFECT THE AREA THURSDAY NIGHT AND FRIDAY. DESPITE THE ACTIVE
WEATHER PATTERN...WINDS AND WAVES SHOULD BE BELOW HEADLINE CRITERIA
THROUGH THE WORK WEEK.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
UPDATE.......KURIMSKI
SHORT TERM...KURIMSKI
LONG TERM....HLO
MARINE.......KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1255 PM EDT MON AUG 13 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL BUILD OVER EASTERN NORTH CAROLINA THROUGH
TUESDAY AS A WEAK FRONT REMAINS STALLED WELL NORTH OF THE AREA. A
COLD FRONT WILL MOVE INTO AREA WEDNESDAY WITH ANOTHER STRONGER
FRONT APPROACHING THE REGION ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1250 PM MONDAY...SHOWERS HAVE DEVELOPED IN AXIS OF SLIGHTLY
HIGHER SURFACE THETA-E OVER THE FAR NORTHEASTERN CWA. EXPECT SOME
ADDITIONAL SHOWERS AND PERHAPS A THUNDERSTORM OR TWO TO DEVELOP
SOUTHWEST ALONG THE SEA BREEZE THROUGH EARLY EVENING. HAVE RAISED
POPS SLIGHTLY OVER TYRRELL AND DARE COUNTIES WITH SLIGHT CHC
CONTINUING ELSEWHERE. LATEST RAP MODEL INDICATES ALL PRECIPITATION
SHOULD END BY 8 PM THIS EVENING. NO OTHER MAJOR CHANGES AT THIS
TIME.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 330 AM MONDAY...DRY CONDITIONS CONTINUE INTO MONDAY NIGHT.
WILL SEE A FEW CLOUDS SPREADING ACROSS THE AREA...THAT WILL LIMIT
FOG POTENTIAL. ALTHOUGH COULD SEE SOME LIGHT BRIEFLY PATCHY GROUND
FOG MONDAY NIGHT...IT WILL NOT BE NEAR THE POTENTIAL THERE IS THIS
MORNING.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 330 AM MON...BROAD LOW AMPLITUDE UPPER TROUGH WILL DEVELOP
ACROSS THE UPPER MISSISSIPPI VALLEY MON AND PUSH EAST TOWARDS THE
GREAT LAKES AND NORTHEASTERN U.S. TUES INTO WED. SURFACE LOW
DEVELOPMENT WILL OCCUR ACROSS THE OHIO RIVER VALLEY WITH A COLD
FRONT EXTENDING SOUTH TO NEAR THE CENTRAL GULF COAST. AS THE UPPER
TROUGH SHIFTS WEST TUES INTO WED A STRONG SHORTWAVE TROUGH WILL
PUSH EAST FROM THE CENTRAL PLAINS AND WILL AID IN SHOWER AND
THUNDERSTORM DEVELOPMENT ALONG THE SURFACE TROUGH TUES NIGHT INTO
WED. TUES WILL BE DRY WITH MID/UPPER LEVELS MOISTENING AS THE FRONT
APPROACHES LATE. PWATS BUILD BACK OVER 1.50 INCHES TUES NIGHT AS
SOUTHERLY FLOW TAKES OVER. OVERALL ONLY MINOR TWEAKS TO PREVIOUS
POPS/WX FORECAST TO REFLECT CHANGES IN GENERAL MODEL BLEND TUES
THROUGH THURS. HAVE MAINTAINED SLIGHT CHANCE TUES NIGHT INCREASING
TO 35-40 PERCENT CHANCE POPS WED. MODEL BLEND QPF FOR THE FRONTAL
PASSAGE WED RANGES 0.25-0.50 INCHES. LOW LEVEL THICKNESSES WILL
RANGE 1410-1415 METERS TUES THROUGH WED WHICH WILL PRODUCE MAX
TEMPS IN THE UPPER 80S WITH SOME SOUTHERN LOCALES REACHING THE
LOWER 90S.
SURFACE RIDGE WILL BUILD IN FROM THE NW THURS BEHIND THE EXITING
FRONT...WITH QUASI-ZONAL FLOW DEVELOPING ALOFT AND THUS KEPT THURS
DRY. LOW LEVEL THICKNESSES CONTINUE 1410-1415 METERS WITH CLEAR
SKIES EXPECTED THURS...MAX TEMPS WILL BUILD INTO THE UPPER 80S TO
LOWER 90S.
TIMING DIFFERENCES ARE APPARENT IN THE EXTENDED FROM FRI TO SUN...HAVE
HEDGED CLOSER TO THE 12Z/12TH ECMWF FOR THIS MORNINGS PACKAGE. THE
RIDGE WILL SHIFT OFFSHORE FRI MORNING ALLOWING RETURN SURFACE FLOW
TO DEVELOP BY FRI. CONTINUED SLIGHT CHANCE POPS FRI AFTERNOON FOR
DIURNAL CONVECTION. ANOTHER UPPER LEVEL TROUGH WILL DEVELOP ACROSS
THE NORTHERN PLAINS STATES FRI THEN AMPLIFY AS IT HEADS EAST
TOWARDS THE GREAT LAKES INTO SAT. AT THE SURFACE A COLD FRONT WILL
EXTEND FROM THE NORTHEASTERN STATES SOUTHWEST TO TN/MS/AL
AND PUSH EAST TOWARDS EASTERN NC ON SAT...BRINGING ANOTHER CHANCE
FOR SHOWERS AND THUNDERSTORMS. ADJUSTED POPS/WX TO BETTER REFLECT
TRENDS IN THE EXTENDED 12Z/12TH ECMWF...HOWEVER 00Z/13TH ECMWF
TRENDED CLOSER TO 00Z/13TH GFS WHICH HANGS UP THE SURFACE TROUGH
ACROSS THE CAROLINAS SAT THROUGH EARLY NEXT WEEK. IF 00Z SCENARIOS
MATERIALIZE THEN WE COULD SEE ANOTHER PROLONGED PERIOD OF UNSETTLED
WEATHER WITH SCATTERED SHOWERS AND THUNDERSTORMS POSSIBLE SAT
THROUGH EARLY NEXT WEEK. LOW LEVEL THICKNESSES CHANGE LITTLE
FRI/SAT THEN FALL TO NEAR 1400 METERS SUN. THESE VALUES WITH
INCREASING CLOUD COVER AND PRECIP SUPPORT TEMPS IN THE MID/UPPER
80S FRI/SAT...THEN LOW TO MID 80S SUN.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH MONDAY NIGHT/...
AS OF 330 AM MONDAY...A FEW SPOTS SAW SOME PATCHY FOG
DEVELOP...WITH CONDITIONS FLUCTUATING WILDLY BETWEEN
LIFR...IFR...AND MVFR CURRENTLY. FOG SHOULD QUICKLY BURN OFF AFTER
SUNRISE. VFR CONDITIONS WILL PERSIST THROUGH MOST OF MONDAY
NIGHT...AS RIDGING BUILDS OVER THE AREA. THERE IS JUST AN ISOLATED
THREAT OF A THUNDERSTORM ON THE SEA BREEZE OR OLD FRONTAL
BOUNDARY. COULD SEE SOME PATCHY FOG DEVELOP AGAIN MONDAY NIGHT. WILL
ALLOW FOR SOME MVFR VISIBILITIES IN THE TAFS TOWARDS MORNING.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM MON...MAINLY VFR CONDITIONS THROUGH THE LONG TERM.
EXPECT DRY CONDITIONS ON TUES. ISOLATED TO SCATTERED STORMS
POSSIBLE WED ASSOCIATED WITH A FRONTAL PASSAGE. EXPECT DRY
CONDITIONS AGAIN THURS WITH INCREASING CLOUDS AND PRECIP CHANCES
FRI AS ANOTHER FRONTAL SYSTEM APPROACHES FROM THE WEST. CANNOT
RULE OUT BRIEF/SHALLOW FOG LATE NIGHT/EARLY MORNING AS WINDS
DECOUPLE TO CALM JUST PRIOR TO SUNRISE.
&&
.MARINE...
SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
AS OF 1255 PM MONDAY...OPTIMAL MARINE CONDITIONS CONTINUE WITH
LIGHT S/SW WINDS...EXCEPT A SLIGHTLY BACKED SE FLOW OVER THE FAR
NORTHERN WATERS NEAR A WEAK BOUNDARY. SEAS REMAIN 2 TO 3 FEET. NO
SIGNIFICANT CHANGES NEEDED TO CURRENT FORECAST.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 345 AM MON...LIGHT FLOW TUES MORNING WILL BECOME SSW AROUND
10-15 KNOTS BY LATE TUES AFTERNOON/NIGHT AS SURFACE GRADIENT
TIGHTENS SLIGHTLY AHEAD OF APPROACHING FRONT. MAY SEE GUSTS
NEARING 20 KT TUES NIGHT BUT EXPECT WINDS TO REMAIN BELOW SCA
LEVELS. SEAS WILL BUILD 2-4 FT WED AS THE FRONT CROSSES THE
WATERS. WINDS WILL BRIEFLY TURN NORTHERLY BEHIND FRONTAL PASSAGE
EARLY THURS MORNING BUT REMAIN 10 KNOTS OR LESS. WINDS WILL SHIFT
BACK SW THURS NIGHT THROUGH THE WEEKEND AND INCREASE 10-15 KNOTS
WITH SEAS 2-4 FT. MINOR ADJUSTMENTS TO 00Z WAVEWATCH III GUIDANCE
WITH OVERALL SMALL CHANGES FROM PREVIOUS FORECAST. SPECTRAL WAVE
GUIDANCE CONTINUES TO INDICATE SE SWELL OF 2 FT AT 9 SECONDS
PERSISTING WED INTO LATE WEEK.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSB
NEAR TERM...CTC
SHORT TERM...RSB
LONG TERM...DAG
AVIATION...RSB/DAG
MARINE...RSB/CTC/DAG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
546 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 545 PM...RECENT RADAR IMAGES INDICATE A WEAKENING LINE OF
SHOWERS AND EMBEDDED TSRA ACROSS EASTERN TN AND NRN GA. RECENT IR
SATELLITE IMAGES INDICATE THAT CLOUD TOP TEMPERATURES ARE WARMING
STEADILY WITH CLOUD TO GROUND LIGHTNING COUNTS DECREASING
SIGNIFICANTLY. HOWEVER...THE BAND SHOULD SURVIVE TO PRODUCE
MEASURABLE RAINFALL ACROSS THE WESTERN NC MTNS AND NE GA THROUGH
EARLY THIS EVENING. BASED ON RADAR AND SATELLITE TRENDS AND THE
CURRENT TEMPERATURE PROFILES...IT APPEARS THAT RAINFALL WILL
DISSIPATE RAPIDLY EAST OF THE SAVANNAH AND FRENCH BROAD RIVER
VALLEYS.
AS OF 430 PM...A BROAD NORTH TO SOUTH ORIENTED LINE OF SHOWERS AND
THUNDERSTORMS WAS LOCATED ALONG THE NORTHERN BORDER BETWEEN AL AND
GA. THE LINE IS PUSHING EAST INTO WEAKLY UNSTABLE AIR...WITH THE
LATEST CAPE ANALYSIS INDICATING ONLY 100 J/KG OF CAPE OVER THE
WESTERN NC MTNS. BASED ON THE RADAR TRENDS...LIGHTNING RATES...AND
RATE OF WARMING CLOUD TOP TEMPERATURES...A BAND OF FADING CONVECTION
WILL REACH THE WESTERN NC MTNS BEFORE TOTALLY DISSIPATING DURING THE
LATE EVENING. I WILL INCREASE POPS TO CHC ACROSS THE WESTERN NC MTNS
AND HIGHLIGHT GENERAL THUNDERSTORMS IN THE HWO. I WILL ALSO UPDATE
THE FORECAST TO ALIGN TEMPS AND DWPTS WITH OBSERVATIONS.
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
432 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 430 PM...A BROAD NORTH TO SOUTH ORIENTED LINE OF SHOWERS AND
THUNDERSTORMS WAS LOCATED ALONG THE NORTHERN BORDER BETWEEN AL AND
GA. THE LINE IS PUSHING EAST INTO WEAKLY UNSTABLE AIR...WITH THE
LATEST CAPE ANALYSIS INDICATING ONLY 100 J/KG OF CAPE OVER THE
WESTERN NC MTNS. BASED ON THE RADAR TRENDS...LIGHTNING RATES...AND
RATE OF WARMING CLOUD TOP TEMPERATURES...A BAND OF FADING CONVECTION
WILL REACH THE WESTERN NC MTNS BEFORE TOTALLY DISSIPATING DURING THE
LATE EVENING. I WILL INCREASE POPS TO CHC ACROSS THE WESTERN NC MTNS
AND HIGHLIGHT GENERAL THUNDERSTORMS IN THE HWO. I WILL ALSO UPDATE
THE FORECAST TO ALIGN TEMPS AND DWPTS WITH OBSERVATIONS.
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...NED
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
320 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INTO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 3 TO 5 DEGREES BELOW
NORMAL WITH AFTERNOON HIGHS IN THE LOW TO MID 80S DURING THE PERIOD.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
254 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM MONDAY...A SHORT WAVE SWINGS ACROSS THE AREA TUE NITE
THEN EAST ON WED...LEAVING NEARLY ZONAL FLOW IN ITS WAKE FOR THU. AT
THE SFC...A COLD FRONT MOVES THRU WITH THE WAVE TUE NITE THEN EAST
OF THE AREA WED AS WELL. HIGH PRESSURE BUILDS IN FOR THU. EXPECT SCT
CONVECTION TO BE ONGOING TUE EVENING WHICH THEN DISSIPATES OVERNIGHT
WITH LOSS OF INSTABILITY. HOWEVER...ISOLATED SHRA COULD LINGER OVER
THE EAST NEAR THE FRONT AND OVER THE MTNS IN THE DEVELOPING WLY FLOW
AND LINGERING LOW LEVEL MOISTURE. ATMOS BECOMES CAPPED WED WITH
WARMER MID LEVEL TEMPS AND DIMINISHING LOW LEVEL MOISTURE IN THE
DEVELOPING WLY FLOW. TEMPS NEAR NORMAL TUE NITE AND WED. ATMOS
REMAINS CAPPED THU AS RELATIVELY WARM MID LEVEL TEMPS CONTINUE. LOW
LEVEL MOISTURE WILL BE LIMITED AS WELL. HOWEVER...ENUF H85 MOISTURE
WILL BE AROUND FOR A DECENT CU FIELD TO DEVELOP DURING THE
AFTERNOON. THEREFORE...HAVE A CONTINUED DRY FCST WITH LOWS FALLING A
LITTLE BELOW NORMAL BUT HIGHS REMAINING NEARLY STEADY AROUND NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM EDT MONDAY...THE LATEST MEDIUM RANGE MODELS INDICATE
THAT A WEAK RIDGE OF HIGH OVER OUR AREA MOVES OFF TO THE EAST ON
LATE THURSDAY AS A COLD FRONT AND ASSOCIATED UPPER TROUGH OVER THE
GREAT LAKES REGION DIGS SOUTH INTO TN/OH. THE FRONT IS EXPECTED TO
SLIP FURTHER SOUTH INTO THE APPALACHIANS BY FRIDAY AND CROSSES OUR
CWA ON SATURDAY. WITH DEEPENING MOISTURE...MODERATE INSTABILITY
AND UPPER LEVEL DIVERGENCE...WILL INCREASE POPS INO THE 30-40
PERCENT RANGE FRI/SAT. SOME THUNDERSTORMS COULD BE SEVERE ON
SATURDAY MAINLY OVER THE BLUE RIDGE AND NORTH CAROLINA PIEDMONT AS
MODEL SOUNDINGS SHOW FAIRLY STRONG 0-6KM BULK WIND SHEAR MAGNITUDE
OF +30KT AND MODERATE CAPE VALUES THERE. AS THE FRONT MOVES OFF TO
THE EAST...HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST SUNDAY AND
REMAIN THROUGH MONDAY. TEMPERATURES WILL REMAIN 5 TO 10 DEGREES
BELOW NORMALS WITH HIGHS IN THE LOW TO MID 80S SATURDAY THROUGH
MONDAY.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK
SHORT TERM...RWH
LONG TERM...JOH
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
206 PM EDT MON AUG 13 2012
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AS
HIGH PRESSURE MOVES OFF THE ATLANTIC COAST. THIS FRONT WILL CROSS
OUR REGION LATE TUESDAY FOLLOWED BY HIGH PRESSURE WEDNESDAY AND
THURSDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE AREA LATE IN
THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 145 PM...THE MAIN THING OF CONCERN FOR THIS UPDATE IS A LINE
OF CONVECTION CROSSING CENTRAL TN AND AL ATTM. THE MODELS DO NOT
SEEM TO BE HANDLING THIS VERY WELL. ATTM...IT STILL LOOKED LIKE THE
LINE WILL LOSE STEAM AS IT ENCOUNTERS STABLE AIR OVER ERN TN AND GA.
WITH THAT SAID...THE LATEST RAP BRINGS INSTBY WITH THE LINE (AS IT
IS NOT MOVING VERY FAST)...SUCH THAT THE SW NC MTNS DO DEVELOP ABOUT
1000-1500 J/KG OF CAPE BY 23Z AS THE LINE ARRIVES. THE CONVECTION
WILL HAVE THE ASSOCIATED MCV TO HELP WITH FORCING AS WELL. SO
ANOTHER UPDATE MAY BE NEEDED SHORTLY TO BUMP UP POP THERE. FOR
SURE...THE MOISTURE WILL SPREAD IN THIS EVENING/OVERNIGHT BRINGING
MAINLY MID AND HIGH CLOUDS. SOME SHWRS MAY SURVIVE INTO THE NC MTNS
THRU DAYBREAK. TEMPS ARE STILL FCST TO DROP TO NORMAL OR EVEN A
CATEGORY BELOW (THO THOSE MAY BE TOO COOL GIVEN EXPECTED CLOUD
COVER).
TUESDAY...A SHORTWAVE TROF WILL ROUND THE BASE OF THE LONGWAVE TROF
AXIS INVOF THE OH/TN VLYS. MEANWHILE...AN ASSOCIATED SFC LOW WILL
TRACK FROM THE MID MS VLY TO AROUND LAKE ERIE BY TUESDAY EVENING.
THE LOW PRES SYSTEM WILL PUSH A COLD FRONT ACRS THE OH/TN VLYS ON
TUESDAY...WITH PRE-FRONTAL BAND OF MOISTURE CROSSING THE CWFA.
GUIDANCE IN GOOD AGREEMENT OF HIGH-END CHC POPS FOR MOST OF THE AREA
WITH DECENT INSTBY AND NOMINAL BULK SHEAR. LLVL CONVERGENCE AND UPR
SUPPORT DO NOT LOOK THAT IMPRESSIVE. SO NOT EXPECTING TOO MUCH
ORGANIZATION. HOWEVER...A FEW SEVERE STORM CLUSTERS WILL BE POSSIBLE
TUESDAY AFTN. TEMPS WILL BE ONE TO TWO CATEGORIES BELOW NORMAL UNDER
MOSTLY CLOUDY SKIES.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AT 315 AM EDT MONDAY...UPPER LEVEL HEIGHTS WILL FALL THROUGHOUT THE
DAY TUE AHEAD OF A WEAKLY FORCED COLD FRONT. THE BEST MID TO UPPER
LEVEL DPVA WILL BE WELL NORTH OF THE AREA AND THE BEST THERMAL
FORCING TO THE SOUTH. THE SOUNDINGS DO DEPICT A DEEP LAYER OF
UNSTABLE AREA....BUT THE DEGREE OF UPWARD ACCELERATION WILL BE ON
THE LOW SIDE DUE TO A RELATIVELY WARM MID/UPPER LAYER. THE BEST LLVL
MOISTURE WILL BE ASSOCIATED WITH THE FRONTAL CONVERGENCE ZONE AS IT
CROSSES THE MTNS AND THEREFORE THE BEST CHANCE POPS WILL BE
MAINTAINED THERE...GENERALLY SCATTERED DIURNAL STORM COVERAGE. SOME
OF THESE STORMS COULD BECOME FAIRLY STRONG TO SEVERE HOWEVER...WITH
DAMAGING DOWNBURSTS BEING THE MAIN THREAT. THE TROF AXIS TRANSITIONS
EAST OF THE AREA EARLY WED...BUT IT WILL HAVE VERY LIMITED MOISTURE
TO WORK WITH AS A SFC LAYERED ANTICYCLONE BUILDS IN AND DRIES UP THE
COLUMN...RAISING LCLS TO AROUND 7 KFT WITH AN ASSOCIATED SHALLOW
MOIST LAYER. POPS FOR THU WILL REMAIN LOW AND NO GOOD CHANCE OF
-SHRA/TSTMS WILL BE ADVERTISED. MAX TEMPS WILL BE RIGHT AROUND
NORMAL TUE AND A BIT HIGHER WED WITH THE INCREASING SUBSIDENCE.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AT 130 AM EDT MONDAY...A SMALL SCALE UPPER RIDGE CONTIUNES MOVING
EAST OF THE AREA THU AND THIS WILL KEEP THINGS MOSTLY DRY AND ABOVE
NORMAL TEMPERTURE/WISE. ISOL LATE AFTERNOON MTN SHOWERS AND A COUPLE
TSTMS ARE PROBABLE...BUT AM NOT EXPECTING LONG LIVED OR VERY STRONG
CONVECTION AS THE ACTIVITY WILL BE MAINLY DIURNALLY FORCED. AS H5
HEIGHTS LOWER FRI...A PRE/FROTNAL TROF PUSHES INTO THE CWFA AND WILL
INSTIGATE AFTERNOON -SHRA/TSTMS ONCE AGAIN...YET MORE WIDESPREAD AND
EAST THAN ON THU. MODELS ARE VERY STINGY WITH LLVL AND ELEVATED
INSTABILITY LEVELS WHILE A BROAD HEIGHT FIELD PRODUCES LITTLE DEEP
LAYERD SHEAR. SO...THE CHANCE FOR A SIGFNT STRONG/SEVERE THREAT
SHOULD BE RATHER LIMITED. FROPA IS EXPECTED FRI NIGHT AND MILD
AIRMASS MIX WILL HELP KEEP SFC BASED INSTABILITY LOW SAT. THE 00Z
GFS IS BRINGING IN TOO MUCH STREAMLINED VORT DUE TO CONV FEEDBACK
OVER THE SRN PLAINS...SO IT/S SOLN OF WIDEPREAD PRECIP AND
CONVECTIVE ACTIVITY WAS GIVEN LITTLE WEIGHT FOR POPS AND SENSIBLE
WEATHER SAT AFTERNOON AND SIDED MORESO WITH THE ECMWF. THUS...EXPECT
A MAINLY DRY WEEKEND WITH RATHER NICE TEMPS AROUND OR A LITTLE BELOW
SEASONAL LEVELS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AT KCLT...FAIR WX (VFR CONDITIONS) EXPECTED THRU THE PERIOD WITH A
LIGHT SLY/SWLY WIND. MOISTURE WILL GRADUALLY INCREASE FROM THE WEST
OVERNIGHT THRU TUESDAY MORNING (GENERALLY MID AND UPR LVL).
CONVECTION WILL APPROACH FROM THE WEST AS WELL...BUT NOT EXPECTING
ANY CONVECTION AT KCLT THRU 18Z TUESDAY AT THIS TIME.
ELSEWHERE...FAIR WX CU AND INCREASING MID AND HIGH CLOUDS INTO THIS
EVENING. THE VFR CLOUDS MAY LIMIT ANY FOG/STRATUS DEVELOP...ALTHOUGH
LLVL MOISTURE WILL ALSO INCREASE FROM THE WEST LATE TNGT. LEFT OUT
ANY MENTION OF RESTRICTIONS FOR NOW. CONVECTION WILL ALSO BE
POSSIBLE WITH THIS MOISTURE BY MIDDAY TUESDAY...SO PROB30 ALREADY
ADDED FOR LAST 2-3 HOURS OF TAFS FOR KAVL/KHKY/KAND. LESS CONFIDENT
FOR KGSP/KGMU AT THIS TIME.
OUTLOOK...A SLOW MOVING COLD FRONT IS EXPECTED TO CROSS THE SOUTHERN
APPALACHIAN REGION TUESDAY AFTERNOON THROUGH TUESDAY
NIGHT...BRINGING A CHC FOR SHRA/TSRA. THE CENTER OF SURFACE HIGH
PRESSURE WILL SETTLE OVER THE REGION ON WEDNESDAY AND REMAIN THROUGH
THE WORK WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...SBK
NEAR TERM...ARK
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...ARK
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
226 PM CDT MON AUG 13 2012
.DISCUSSION...
MORNING CONVECTION HAS MOVED EAST OF THE MIDSOUTH AS EXPECTED WITH
PARTIAL SUNSHINE SPREADING OVER THE AREA FROM THE WEST.
MEANWHILE...A COLD FRONT IS PUSHING INTO NORTHEAST ARKANSAS AND
STRETCHES SOUTHWESTWARD INTO NORTHEAST TX. THE FRONT HAS MOVED
THROUGH WALNUT RIDGE ARKANSAS AND IS APPROACHING JONESBORO.
STILL THINK THERE IS A CHANCE OF SEVERE THUNDERSTORMS LATER THIS
AFTERNOON INTO THIS EVENING ALONG AND AHEAD OF THE COLD
FRONT...ALTHOUGH THE SITUATION IS NOT CLEAR CUT. WATER VAPOR IMAGERY
INDICATES THE MAIN UPPER LEVEL TROUGH IS MOVING EAST OF THE MIDSOUTH
WITH UPPER LEVEL SUPPORT NOW LIMITED ACROSS OUR FORECAST AREA. WATER
VAPOR IMAGERY IS ALSO SHOWING VERY DRY AIR ALOFT MOVING INTO OUR
FORECAST AREA. HOWEVER...VERY WARM AND UNSTABLE AIR IS PUSHING INTO
THE AREA AHEAD OF THE FRONT ON SOUTHWEST SURFACE WINDS. TEMPERATURES
IN NORTHEAST AND EAST CENTRAL AR ARE MOVING INTO THE LOWER 90S AND
SURFACE BASED CAPES HAVE INCREASED TO BETWEEN 2000 AND 2500 J/KG AND
LIFTED INDICES HAVE DECREASED TO ABOUT MINUS 6.
LATEST HIGH RESOLUTION RAPID REFRESH (HRRR) MODEL INDICATES THAT
SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN TO FORM ALONG THE
COLD FRONT BY 3 OR 4 PM...THEN BECOME A LITTLE BETTER ORGANIZED AS
THE STORMS MOVE EAST OF THE MS RIVER BY LATE AFTERNOON AND EVENING.
MODELS CONTINUE TO INDICATE THE ATMOSPHERE WILL BECOME QUITE
UNSTABLE AHEAD OF THE FRONT WITH SURFACE BASED CAPES INCREASING TO
BETWEEN 32000 AND 4200 J/KG WITH LIFTED INDICES DECREASING TO MINUS
8. ALTHOUGH...THE HRRR MODEL INDICATES THE STORMS WILL STRUGGLE IN
COVERAGE WITH SUCH DRY AIR ALOFT LIMITING THE MOISTURE.
ALTHOUGH...THE DRY AIR ALOFT WILL ENHANCE THE DOWNDRAFT POTENTIAL
WITH DAMAGING STRAIGHT LINE WINDS POSSIBLE IN THE STRONGER STORMS.
LARGE HAIL IS ALSO POSSIBLE.
THE COLD FRONT IS FORECAST NEAR THE MS RIVER BY LATE
AFTERNOON...THEN WILL MOVE SOUTHEASTWARD THROUGH THE MIDSOUTH
TONIGHT. THINK THE SEVERE WEATHER THREAT WILL END BY LATE EVENING.
NOT MUCH CHANGE TO THE EARLIER FORECAST CONCERNING TUESDAY THROUGH
THE WEEKEND. HIGH PRESSURE AND DRIER AIR WILL SPREAD OVER THE
MIDSOUTH TUESDAY INTO WEDNESDAY ALLOWING FOR GOOD DIURNAL SPREADS IN
TEMPERATURES WITH RELATIVELY COOL NIGHTS AND VERY WARM AFTERNOONS.
A WARM FRONT IS FORECAST TO PUSH THROUGH THE MIDSOUTH THURSDAY WITH
VERY UNSTABLE AND MOIST AIR SPREADING BACK OVER THE AREA. THIS WILL
CAUSE A CHANCE OF SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST THURSDAY NIGHT AND MOVE SLOWLY THROUGH
THE REGION FRIDAY INCREASING THE THREAT OF SHOWERS AND
THUNDERSTORMS. THERE WILL BE A LINGERING CHANCE OF SHOWERS AND
THUNDERSTORMS ACROSS EAST CENTRAL ARKANSAS AND NORTH MS SATURDAY BUT
OTHERWISE KEPT WITH A RAINFREE FORECAST FOR THE WEEKEND INTO NEXT
MONDAY. HOWEVER...THERE IS SOME QUESTION HOW FAR THE COLD FRONT WILL
SETTLE SOUTHWARD BECOMING STALLING...SO SOME CHANCE OF SHOWERS AND
THUNDERSTORMS COULD LINGER ACROSS EAST CENTRAL AR AND NORTH MS INTO
SUNDAY.
JCL
&&
.AVIATION...
18Z TAF CYCLE
VFR CONDITIONS WILL PERSIST AT TAF SITES FOR THIS TAF PERIOD
OUTSIDE OF THUNDERSTORMS. A LINE OF SHOWERS AND THUNDERSTORMS MAY
DEVELOP NEAR OR JUST EAST OF THE MISSISSIPPI RIVER THIS AFTERNOON
AS THE ATMOSPHERE DESTABILIZES AGAIN AND AN ASSOCIATED COLD FRONT
PUSHES THROUGH THE AREA. SOUTH TO SOUTHWEST WINDS WILL RANGE FROM
10-12 KTS THIS AFTERNOON VEER NORTHWEST TONIGHT AS THE COLD FRONT
PASSES THROUGH THE AREA. MVFR CONDITIONS ALSO POSSIBLE AT MKL/TUP
BETWEEN 14/08-12Z.
SWC
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 70 88 68 93 / 20 0 10 10
MKL 66 86 59 90 / 30 10 10 10
JBR 65 87 62 92 / 10 0 10 10
TUP 71 89 65 91 / 50 10 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1222 PM CDT MON AUG 13 2012
.DISCUSSION...
SEE AVIATION DISCUSSION BELOW.
&&
.AVIATION...
PORTIONS OF SE TX MAY EXPERIENCE AN ISOLATED THUNDERSTORM LATE
THIS AFTERNOON INTO THE EARLY EVENING. GENERALLY EXPECT THIS
ACTIVITY TO BE ASSOCIATED WITH THE SEABREEZE AND POSSIBLE FROM
OUTFLOWS WHICH MOVE SOUTHWARD FROM ANY ACTIVITY WHICH MAY DEVELOP
NORTH OF KUTS. OTHERWISE EXPECT VFR ALTHOUGH THERE IS AN OUTSIDE
CHANCE OF MVFR CEILINGS AROUND AND AFTER SUNRISE TUESDAY MORNING.
40
&&
.PREV DISCUSSION... /ISSUED 949 AM CDT MON AUG 13 2012/
UPDATE...
MINOR UPDATES FOR TODAY FOR OBSERVED TRENDS AND TO CLEAN UP ZONE
WORDING.
DISCUSSION...
24 HOUR DIFFERENCE FROM 14Z YESTERDAY SHOWS MOST LOCATIONS AT OR
WITHIN A DEGREE OF YESTERDAY. SMALL UPDATES TO HOURLY/MAX TEMPS
AND DEW POINTS FOR TODAY. STILL HOT AND HUMID WITH HEAT INDICES IN
THE 100-105 RANGE. FCST SOUNDINGS AND MDCRS/AIRCRAFT SOUNDINGS
THIS MORNING SHOW 11 TO 12C 700MB TEMPERATURES WHICH SHOULD KEEP
CONVECTION ISOLATED ALONG THE SEA BREEZE TODAY. DID INCLUDE ISO
POPS FOR SOUTHERN COUNTIES JUST INLAND PER 11Z HRRR FCST
REFLECTIVITY FIELDS. SLIGHTLY BETTER SHRA/TSRA CHANCES FOR
NORTHERN AND NORTHEASTERN COUNTIES THIS AFTERNOON FROM LEFTOVER
OUTFLOW BOUNDARIES AND CLOSER TO 850MB TROUGH EVIDENT IN AREA
VWP/PROFILER WINDS. 04
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 99 / 20 10 10 10 10
HOUSTON (IAH) 96 78 97 77 96 / 20 10 20 10 10
GALVESTON (GLS) 91 82 90 82 90 / 10 10 20 10 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...04
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
620 PM EDT MON AUG 13 2012
.SYNOPSIS...
HIGH PRESSURE WILL EXIT THE REGION TONIGHT AND MAKE WAY FOR AN
APPROACHING COLD FRONT. THIS FRONT WILL MOVE THROUGH THE REGION
TOMORROW EVENING. IN ITS WAKE...HIGH PRESSURE WILL RETURN TO THE
REGION WITH YET ANOTHER...AND PERHAPS STRONGER...COLD FRONT SLATED
TO CROSS THE REGION FRIDAY INTO SATURDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
AS OF 612 PM EDT MONDAY...
EARLY EVENING UPDATE MAINLY TO REDUCE POPS ACROSS THE SW THIS
EVENING GIVEN MAIN AXIS OF SHRA PASSING TO THE SW...AND THEN TO
INCLUDE SOME CHANCE POPS AFTER MIDNIGHT ACROSS THE WEST PER SHRA
DEVELOPMENT BEHIND THE PRE-FRONTAL RH LOBE ATTM. THIS SUPPORTED
VIA THE LATEST HRRR WHICH BRINGS SOME OF THIS LEFTOVER CONVECTION
INTO THE WESTERN ZONES LATE IN CONJUNCTION WITH MOISTENING OF MID
LEVELS OFF LATEST FORECAST RAOBS. ALSO LOWERED TEMPS SOME OVER THE
SW WHERE HEATING WAS LESS DUE TO EARLY ARRIVAL OF THE MID DECK
CANOPY.
AS OF 315 PM EDT MONDAY...
INFLUENCE OF HIGH PRESSURE WILL CONTINUE THROUGH THIS EVENING.
PRECIPITATION WILL BE VERY LIMITED...IF EXISTS AT ALL. THE GREAT
POTENTIAL WILL BE ALONG THE CREST OF THE BLUE RIDGE SOUTHWEST OF
FLOYD INTO THE NORTHERN MOUNTAINS OF NORTH CAROLINA...AND IN AREAS
ALONG AND NEAR THE NC/VA BORDER.
OVERNIGHT...MID TO HIGH LEVEL CLOUD COVER IS EXPECTED TO OVERSPREAD
THE REGION AS DEBRIS CLOUD COVER FROM AN APPROACHING COLD FRONT
ADVECTS INTO THE REGION. THIS WILL HAVE THE RESULT OF
LIMITED...ALTHOUGH NOT COMPLETELY PREVENTING...THE DEVELOPMENT OF
PRIMARILY LATE NIGHT MOUNTAIN VALLEY FOG...ESPECIALLY OVER PARTS OF
THE GREENBRIER AND NEW RIVER VALLEYS. SOME ISOLATED TO SCATTERED
SHOWERS WILL BE POSSIBLE OVER SOUTHEAST WEST VIRGINIA BY SUNRISE IN
ASSOCIATION WITH THE APPROACHING FRONT.
ON TUESDAY...THE FRONT WILL DRAW EVEN CLOSE TO THE REGION DURING THE
DAY TUESDAY. ISENTROPIC LIFT IN ADVANCE OF THE FRONT WILL HELP TO
PROVIDE GENEROUS COVERAGE OF SHOWERS AND STORMS BY MIDDAY ACROSS ALL
BUT THE FAR EASTERN SECTIONS OF THE REGION. BY THE LATE
AFTERNOON...ALL AREAS ARE EXPECTED TO HAVE AT LEAST SCATTERED
COVERAGE OF SHOWERS AND STORMS...WITH THE GREATEST COVERAGE ACROSS
SOUTHEAST WEST VIRGINIA AND AREAS ALONG AND NEAR THE CREST OF THE
BLUE RIDGE.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 112 PM EDT MONDAY...
JUST SOME MINOR TWEAKS TO THE PREVIOUS FORECAST FOR THIS TIME
PERIOD. MODELS SHOW A DECENT SHORTWAVE SHIFTING EAST ACROSS THE ARE
TUE NIGHT INTO WED MORNING...SO EXPECT TO SEE LINGERING SHOWERS OR
STORMS IN THE EAST TUE EVENING AND SOME UPSLOPE ENHANCE SHOWERS
ACROSS THE MTNS INTO WED MORNING BEFORE SUBSIDENCE STARTS TO DRY THE
COLUMN OUT SUBSTANTIALLY. THE UPPER FLOW STAYS IN A GENERAL WRLY
DIRECTION AFTER THE FRONTAL PASSAGE AND ONLY EXPECTING MEAGER DROPS
IN THE DEWPOINTS WITH TEMPS REMAINING JUST AS WARM AS TUESDAY.
A WEAK HIGH PRESSURE SYSTEM LINGERS ACROSS THE AREA INTO THURSDAY
DURING WHICH SKIES SHOULD REMAIN CLEAR-PARTLY CLOUDY.
SHOULD SEE INCREASING CLOUDS AHEAD OF NEXT TROUGH AND SFC FRONT LATE
THU NIGHT...BUT ANY PRECIP SHOULD HOLD OFF UNTIL FRIDAY.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 112 PM EDT MONDAY...
POSITIVE PNA PATTERN WITH TROUGH IN THE EASTERN U.S./TROUGH WEST
COAST WILL BE THE UPPER AIR FLOW INTO THE EXTENDED PERIOD WITH SOME
BREAKDOWN IN THE WRN RIDGE AFTER NEXT MONDAY.
THE NEXT FRONT WILL SLIDE INTO THE AREA FRIDAY INTO SATURDAY. UPPER
PATTERN SUPPORTS SLOWER MOVEMENT OF FRONT AND COULD SEE THE FRONT
STALL JUST SOUTH AND EAST OF THE FORECAST AREA OVER THE WEEKEND. THE
ECMWF ALLUDES TO MORE CLOUDS ACROSS THE SRN CWA INTO SUNDAY WITH AN
INCREASE IN PRECIP CHANCES HEADING INTO MONDAY ACROSS SRN VA/NRN NC.
FOR NOW WILL KEEP THE AREA DRY MONDAY...PER HPC AND ENSEMBLE
LEANINGS...GIVEN THE TROUGH DOES LOOK TO DEEPEN JUST ENOUGH.
SO FOR THIS PERIOD...THINK AT LEAST A CHANCE POPS WARRANTED FRI-SAT
WITH SOME DRYING ACROSS THE REGION SAT NIGHT-SUN WITH A FEW
LINGERING SHOWERS IN THE PIEDMONT...THEN MAINLY DRY WITH INCREASING
CLOUDS AROUND SUN NIGHT INTO MONDAY ACROSS THE PIEDMONT SOUTHWEST
INTO THE NC FOOTHILLS.
TEMPS THIS PERIOD SHOULD COOL OFF AGAIN TOWARD WHAT WE HAD THIS PAST
WEEKEND WITH HIGHS IN THE 70S WEST TO LOWER 80S EAST...WHILE LOWS AT
NIGHT RANGE FROM THE LOWER 50S WEST TO LOWER 60S EAST.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AS OF 140 PM EDT MONDAY...
VFR CONDITIONS ARE EXPECTED THROUGH THE EVENING HOURS FOR THE VAST
MAJORITY OF THE REGION. ISOLATED SHOWERS...AND PERHAPS A
THUNDERSTORM OR TWO...ARE POSSIBLE THIS AFTERNOON MAINLY NEAR THE
NC/VA BORDER...AND ALONG THE CREST OF THE BLUE RIDGE FROM SOUTH OF
KROA TO NEAR KTNB. OVERNIGHT...MID TO HIGH LEVEL CLOUDINESS WILL
OVERSPREAD THE AREA IN ADVANCE OF OUR NEXT COLD FRONT. THIS WILL
LIMIT THE EXTENT OF ANY MVFR MOUNTAIN OR RIVER VALLEY FOG. THE
ADVANCING COLD FRONT WILL PROMPT AN INCREASE IN SHOWERS AND STORMS
DURING THE DAY TOMORROW. ANTICIPATE THE KBLF-KLWB AREA WILL HAVE
SCATTERED SHOWERS AND PERHAPS A RUMBLE OR TWO OF THUNDER AFTER
14Z...10AM. HAVE INDICATED VCSH IN THE WEATHER GROUP AT THESE TAF
SITES TOMORROW TO INDICATE THIS.
LOCALIZED SUB-VFR CIGS AND VSBYS WILL BE POSSIBLE UNDER THE
STRONGEST CONVECTIVE CELLS TUESDAY AND TUESDAY EVENING.
NIGHTTIME SUB-VFR MOUNTAIN OR RIVER VALLEY FOG WILL BE POSSIBLE
THIS WEEK...ESPECIALLY IN AREAS THAT RECEIVE RAIN ON TUESDAY.
INCREASED COVERAGE OF SHOWERS AND STORMS AGAIN FRIDAY INTO
SATURDAY WITH THE PASSAGE OF THE NEXT COLD FRONT.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS
NEAR TERM...DS/JH
SHORT TERM...WP
LONG TERM...WP
AVIATION...DS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
259 PM CDT MON AUG 13 2012
.SHORT TERM...TONIGHT AND TUESDAY.
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW SHORTWAVE
TROUGHING MOVING ACROSS EASTERN WISCONSIN EARLY THIS AFTERNOON. A
SECONDARY FRONT IS MOVING INTO NORTHWEST WISCONSIN AS WELL WHICH IS
INTERACTING WITH STEEP LOW LEVEL LAPSE RATES AND 200-400 J/KG OF ML
CAPE TO CREATE SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS.
LOOKING UPSTREAM...PLENTY OF CU OVER MINNESOTA AND SOUTH-CENTRAL
CANADA WHERE ADDITIONAL WEAK SHORTWAVE ENERGY IS MOVING INTO THE
WESTERN LAKE WINNIPEG REGION. THE MAIN FORECAST CONCERNS INCLUDE
TIMING THE END OF PRECIP CHANCES THIS EVENING...AND SMALL PRECIP
CHANCE TOMORROW AFTERNOON.
TONIGHT...THE SHORTWAVE TROUGH OVER EASTERN WISCONSIN WILL EXIT
DURING THE EVENING AND SHOWERS WILL BE WEAKENING WITH LOSS OF
HEATING. THE LATEST SHORT RANGE GUIDANCE AND ESTIMATES FROM STORM
MOTION SUGGEST SHOWERS WILL LINGER INTO EARLY THIS EVENING OVER FAR
NE INTO CENTRAL WISCONSIN...SO WILL KEEP A SHOWER MENTION TROUGH MID
EVENING. CLOUDS MAY BE SLOWER TO DISSIPATE AS A WEAK FRONT WASHES
OUT ACROSS THE REGION. WILL SHOW PARTLY CLOUDY CONDITIONS BECOMING
MOSTLY CLEAR OVERNIGHT. LOW LEVEL MOISTURE IS NOT REALLY ALL THAT
DRY THOUGH...SO WITH CLEARING SKIES AND LIGHT WINDS...COULD SEE
PATCHY FOG DEVELOP LATE...ESPECIALLY OVER THE COLD SPOTS OF N-C
WISCONSIN. LOWS IN THE UPPER 40S NORTH TO MID 50S SOUTH.
TUESDAY...NORTHWEST FLOW WILL PREVAIL ALOFT WHILE WEAK HIGH PRESSURE
WILL BE AT THE SURFACE. A WEAK SHORTWAVE NOW OVER SOUTHERN MANITOBA
WILL SLOWLY PASS ACROSS THE STATE. PROGGED SOUNDINGS LOOK SIMILAR TO
TODAYS..WITH STEEP LOW LEVEL LAPSE RATES AND ML CAPES UP TO 500 J/KG
DEVELOPING IN THE AFTERNOON. WILL HAVE WEAK CONVERGENCE ALONG THE
LAKE BREEZE FOR A FOCUS MECHANISM SO LIKE HAVING A CHANCE OF SHOWERS
OVER NORTHERN WISCONSIN FOR THE AFTERNOON. WARMED HIGHS UP A COUPLE
DEGREES AND WENT MID 70S TO LOW 80S.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT MONDAY. OTHER THAN TIMING
OF THE COLD FRONT LATE WEDNESDAY NIGHT OR THURSDAY THE MEDIUM
RANGE MODELS ARE IN PRETTY GOOD AGREEMENT INTO EARLY NEXT WEEK.
WEAK UPPER RIDGING SHOULD PROVIDE DRY WEATHER TUESDAY NIGHT AND
WEDNESDAY. UPPER DIFFLUENCE INCREASES WEDNESDAY NIGHT AS THE UPPER
TOUGH APPROACHES AND LOW LEVEL MOISTURE INCREASES AS WELL. SHOULD
GET A GOOD AREA OF SHOWERS AND THUNDERSTORMS MOVING INTO THE
WESTERN PART OF THE FORECAST AREA LATE WEDNESDAY NIGHT AND ACROSS
THE EAST THURSDAY MORNING. TIMING OF THE FRONT IS NOT IDEAL FOR
SEVERE THUNDERSTORMS SO THINK THAT THE SEVERE THREAT IS LOW.
UPPER FLOW BECOMES NORTHWEST FRIDAY AND SATURDAY AND A LARGE
SURFACE HIGH DROPS IN FROM THE NORTHERN PLAINS. WHILE IT SHOULD BE
GENERALLY DRY THERE IS A SMALL CHANCE OF MAINLY AFTERNOON SHOWERS
ACROSS THE NORTH IN THE COLD AND CYCLONIC FLOW. SURFACE HIGH
SHOULD BE RIGHT OVER THE AREA FRIDAY NIGHT AND WOULD NOT BE
SURPRISED TO SEE SOME FROST IN THE FAR NORTH.
&&
.AVIATION...A WEAK STORM SYSTEM WILL PASS ACROSS THE STATE THIS
AFTERNOON BEFORE EXITING THIS EVENING. A FEW SHOWERS ARE POSSIBLE
OVER NORTH-CENTRAL WISCONSIN THIS AFTERNOON...AND INCLUDED A TEMP
GROUP THIS AFTERNOON AT RHI. WILL SEE BKN VFR CIGS DEVELOP THIS
AFTERNOON AS INSTABILITY DEVELOPS WITH THE HEAT OF THE DAY...BUT
CLEARING WILL ENSUE ONCE THE SUN GOES DOWN. CALM WINDS AND CLEARING
SKIES WILL LEAD TO PATCHY FOG DEVELOPMENT EARLY TUESDAY MORNING.
VSBYS MAY FALL TO THE IFR RANGE WITHIN ANY GROUND FOG. VFR
CONDITIONS ON TUESDAY WITH CLOUDS BUILDING MIDDAY.
MPC
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MPC/RDM