Forecast Discussions mentioning any of "HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/18/12

AREA FORECAST DISCUSSION

NWS ALBANY NY

 1030 AM EDT THU AUG 16 2012

.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM PENNSYLVANIA THIS
AFTERNOON WITH A BRIEF PERIOD OF FAIR AND DRY WEATHER. A COLD FRONT
WILL MOVE THROUGH FRIDAY AFTERNOON...TRIGGERING MORE SHOWERS AND
THUNDERSTORMS...AND WILL BE FOLLOWED BY FAIR AND COOLER CONDITIONS
FOR THE WEEKEND.
&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT...SFC HIGH PRESSURE CONTINUES TO RIDGE IN FROM
W-CNTRL PA. THE RUC SHOWS A MID-LEVEL RIDGE AXIS BUILDING IN FROM
LAKE HURON AND MICHIGAN. AN UPPER-LEVEL IMPULSE IS FEEDING INTO
THE SFC WAVE NEAR MAINE. THE WATER VAPOR LOOP CONTINUES TO SHOW
LOTS OF MID AND UPPER LEVEL DRY AIR FILTER IN ALOFT. THE CUMULUS
FIELD IS NOT THAT IMPRESSIVE IN THE LATE MORNING. WE REMOVED ALL
THE POPS FOR THE LATE MORNING AND AFTERNOON. THERE MAY BE SOME
INSTABILITY CUMULUS OVER SRN GREENS..BERKS...TACONICS...AND
LITCHFIELD HILLS...BUT THE LATEST 12Z RAOB SHOWS A PAIR OF MID AND
UPPER LEVEL INVERSIONS WHICH SHOULD LIMIT ANY DEEP COLD POOL
RELATED CONVECTIVE GROWTH.

PARTLY TO MOSTLY SUNNY CONDITIONS WILL PREVAIL WITH MANAGEABLE
HUMIDITY LEVELS. STUCK WITH CURRENT MAX TEMPS FOR NOW...WITH
LOWER/MID 80S IN VALLEY REGIONS...AND 75-80 ACROSS HIGHER
ELEVATIONS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
TONIGHT...MAINLY CLEAR SKIES ARE EXPECTED FOR MUCH OF THE
NIGHT...BEFORE SOME MID LEVEL CLOUDS APPROACH FROM THE WEST. THERE
IS A POSSIBILITY THAT SOME SHOWERS OR THUNDERSTORMS REACH FAR NW
AREAS TOWARD DAYBREAK...AS A LOW LEVEL JET WITHIN INCREASING WARM
ADVECTION TRANSLATES TOWARD THIS REGION. ELSEWHERE...HAVE KEPT
CONDITIONS RAIN-FREE.

FRIDAY...A COLD FRONT WILL APPROACH FROM THE WEST DURING THE MID
TO LATE AFTERNOON HOURS. SCATTERED SHOWERS AND THUNDERSTORMS WILL
LIKELY DEVELOP WITHIN A NARROW BAND NEAR OR JUST AHEAD OF THE
FRONT...DEVELOPING ACROSS WESTERN AREAS BY LATE MORNING...THEN
SPREADING INTO THE CAPITAL REGION BY MIDDAY/EARLY AFTERNOON...AND
AREAS TO THE S/E BY LATE AFTERNOON. ABUNDANT HIGH AND MID LEVEL
CLOUDS ARE EXPECTED TO ENVELOPE THE REGION BY LATE MORNING...WHICH
MAY TEND TO LIMIT POTENTIAL DESTABILIZATION AND THUNDERSTORM
INTENSITY...DESPITE INCREASING 0-6 KM VERTICAL SHEAR OF 30-40 KT
BY LATE AFTERNOON. SHOULD MORE SUNSHINE OCCUR...THEN THE GREATER
DESTABILIZATION COULD LEAD TO STRONG TO SEVERE
THUNDERSTORMS...WITH STRONG WINDS AND HAIL POSSIBLE. THE STORM
PREDICTION CENTER INDICATES THAT A CATEGORICAL SLIGHT RISK MAY BE
WARRANTED DEPENDING ON HOW MUCH DESTABILIZATION CAN OCCUR.
OTHERWISE...EXPECT MAX TEMPS TO REACH THE LOWER/MID 80S IN
VALLEYS...AND 70S ACROSS HIGHER ELEVATIONS ACROSS NORTHERN AREAS.

FRI NT...THE COLD FRONT WILL BE SLOWING ITS SE PROGRESSION...AS
THE RIGHT ENTRANCE REGION OF A JET MAX ACROSS THE EASTERN GREAT
LAKES APPROACHES. THIS MAY TEND TO KEEP SHOWERS/THUNDERSTORMS
LINGERING WELL INTO THE NIGHT ACROSS THE MID HUDSON VALLEY REGION
AND NW CT...POSSIBLY INTO THE BERKSHIRES...WHERE CHC POPS ARE
RETAINED THROUGH THE NIGHT. ELSEWHERE...OTHER THAN POSSIBLE
EVENING SHOWERS...HAVE TRENDED TOWARD DRY CONDITIONS LATER AT
NIGHT...ALONG WITH SOME CLEARING. HAVE SIDED WITH BLEND OF MAV/MET
MOS FOR MIN TEMPS.

SAT-SAT NT...HAVE KEPT SOME SLIGHT CHC POPS ACROSS FAR SE AREAS
FOR SAT MORNING...OTHERWISE EXPECT GENERALLY DRY AND LESS HUMID
CONDITIONS. MAX TEMPS SHOULD REACH 75-80 IN VALLEYS...AND 60S TO
LOWER 70S ACROSS HIGHER ELEVATIONS. FOR SAT NT...IT SHOULD BE
QUITE COOL ACROSS PORTIONS OF THE SOUTHERN ADIRONDACKS...AND
HIGHER ELEVATIONS IN SOUTHERN VT...WHERE SOME MIN TEMPS MAY FALL
INTO THE UPPER 30S TO MID 40S. ELSEWHERE...EXPECT MINS TO FALL
INTO THE 50S.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
EXPECT GENERALLY DRY WEATHER FOR MUCH OF THE LONG TERM PERIOD EXCEPT
FOR EARLY IN THE WEEK AS WAVES OF LOW PRESSURE WORK NORTHWARD ALONG A
STATIONARY FRONT ANCHORED ALONG EASTERN SEABOARD. THE BIGGEST IMPACT
WILL BE ACROSS SOUTHERN AND EASTERN ZONES CLOSEST TO THE FRONTAL
BOUNDARY WHERE HIGHEST CHANCE POPS HAVE BEEN PLACED IN THE FORECAST
GRIDS. FROM TUESDAY INTO WEDNESDAY HIGH PRESSURE BUILDS OVER THE
NORTHEAST AS FRONTAL BOUNDARY SLIDES WELL TO THE SOUTH AND EAST.

ON SUNDAY HAVE SLIGHT CHANCE TO LOW CHANCE POPS IN THE GRIDS WITH
HIGHEST POPS FROM THE EASTERN CATSKILLS SOUTHEAST TO THE LITCHFIELD
HILLS DURING THE AFTERNOON WITH SLIGHT CHANCE POPS ON SUNDAY NIGHT.
EXPECT HIGHS ON SUNDAY MAINLY IN THE UPPER 60S TO UPPER 70S WITH A
FEW READINGS AROUND 80 IN THE MID HUDSON VALLEY. LOWS SUNDAY NIGHT
ARE EXPECTED TO BE IN THE UPPER 40S TO UPPER 50S.

FOR MONDAY...A VORT MAX SWINGING AROUND THE UPPER TROUGH WILL RESULT
IN SCATTERED SHOWERS AND POSSIBLY EVEN AN ISOLD THUNDERSTORM.  THE
INSTABILITY LOOKS LIMITED AT THIS TIME. HIGHS ARE EXPECTED TO BE IN
THE MID 60S TO UPPER 70S.

MON NIGHT THROUGH WEDNESDAY...HIGH PRESSURE AT THE SFC CONTINUES TO
BUILD IN FROM THE SOUTH AND WEST WITH FAIR AND DRY WEATHER...AND
COMFORTABLE HUMIDITY LEVELS. HIGHS TUESDAY AND WEDNESDAY GENERALLY
UPPER 60S TO UPPER 70S WITH LOWS MONDAY NIGHT AND TUESDAY NIGHT IN
THE 50S.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
EXPECT MAINLY VFR CONDITIONS AT THE TAF SITES THROUGH THE END OF THE
TAF PERIOD AT 12Z FRIDAY. THE EXCEPTION WILL BE SOME LATE NIGHT FOG
TONIGHT AFTER 08Z AT KGFL AND KPSF WHERE BRIEF IFR CONDITIONS
EXPECTED. THERE MAY ALSO BE SOME SHOWERS DEVELOPING MAINLY EAST OF
THE HUDSON RIVER AS UPPER TROUGH SWINGS THROUGH THIS REGION. WL
PLACE VCSH IN THE TAF FOR KPSF UP UNTIL 18Z. EXPECT GENERALLY
SCT045-070 THROUGH ERLY THIS EVENING AND THEN SKC CONDITIONS AFT 00Z
WITH THE AFOREMENTIONED FOG EXPECTED AT KGFL AND KPSF AFT 08Z.

LIGHT AND VARIABLE WINDS WILL BECOME NORTHWEST THIS MORNING AT 3-7
KTS AND THEN LIGHT AND VARIABLE AGAIN THIS EVENING.

OUTLOOK...
FRI...VFR. CHC PM SUB-VFR SHRA/TSRA.
SAT-SUN...VFR...NO SIG WX.
MONDAY...VFR. CHC SUB-VFR -SHRA.

&&

.FIRE WEATHER...
HIGH PRESSURE WILL BUILD IN FROM PENNSYLVANIA THIS
AFTERNOON WITH A BRIEF PERIOD OF FAIR AND DRY WEATHER. A COLD FRONT
WILL MOVE THROUGH FRIDAY AFTERNOON...TRIGGERING MORE SHOWERS AND
THUNDERSTORMS...AND WILL BE FOLLOWED BY FAIR AND COOLER CONDITIONS
FOR THE WEEKEND.

THE RH WILL FALL TO 40-50 PERCENT THIS AFTERNOON...THEN RECOVER TO
90-100 PERCENT TONIGHT...WITH DEW FORMATION LIKELY. THE RH WILL
THEN FALL TO 45-60 PERCENT FRI AFTERNOON.

WINDS WILL BECOME WEST TO NORTHWEST AT 5-15 MPH THIS
AFTERNOON...THEN TREND TOWARD CALM TONIGHT. WINDS WILL BECOME
SOUTH TO SOUTHWEST FRIDAY AT 10-20 MPH. WINDS WILL BE
STRONGER...AND VARIABLE IN DIRECTION IN AND NEAR ANY THUNDERSTORMS
TODAY AND FRIDAY.

&&

.HYDROLOGY...
ISOLATED SHOWERS AND THUNDERSTORMS WILL REMAIN POSSIBLE THROUGH
EARLY THIS AFTERNOON...ESPECIALLY FROM THE HUDSON RIVER VALLEY
EASTWARD. LOCALLY HEAVY...SLOW MOVING DOWNPOURS WILL BE
POSSIBLE...WHICH COULD RESULT IN PONDING OF WATER IN LOW
LYING...POOR DRAINAGE AND URBAN AREAS.

A COLD FRONT WILL BRING ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS
FOR FRIDAY AFTERNOON AND EVENING. AREAL BASIN AVERAGE AMOUNTS
SHOULD GENERALLY REMAIN UNDER ONE QUARTER OF AN INCH.
HOWEVER...LOCALIZED HEAVIER DOWNPOURS COULD RESULT IN PONDING OF
WATER ONCE AGAIN IN LOW LYING...POOR DRAINAGE AND URBAN AREAS.

DRY CONDITIONS ARE EXPECTED OVER THE WEEKEND.

&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.

&&

$$
SYNOPSIS...KL/WASULA
NEAR TERM...KL/WASULA
SHORT TERM...KL
LONG TERM...11
AVIATION...11
FIRE WEATHER...KL
HYDROLOGY...KL








AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 127 AM EDT THU AUG 16 2012

.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM AND WEAK LOW PRESSURE ACROSS THE AREA
LATE THIS AFTERNOON WILL MOVE TO THE EAST OVERNIGHT. THIS WILL ALLOW
HIGH PRESSURE FROM THE OHIO VALLEY TO BUILD ACROSS THE REGION. THIS
HIGH WILL REMAIN THROUGH FRIDAY EVENING...BEFORE A COLD FRONT
CROSSES THE AREA. THIS FRONT WILL SLOW DOWN AS IT MOVES OFF THE
COAST SATURDAY. MORE HIGH PRESSURE WILL BUILD OVER THE AREA SATURDAY
NIGHT AND LAST INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LAST OF THE CONVECTION HAS MOVED OFFSHORE...AND THE INSTABILITY
IS NOT FAR BEHIND. THE SURFACE FRONT HAS CROSSED MUCH OF THE AREA...
BUT THE AIRMASS CHANGE IS STILL BACK OVER WESTERN PENNSYLVANIA.
WINDS ARE FAIRLY LIGHT...AND THE LOW LEVEL REMAIN MOIST...ESPECIALLY
AREAS THAT RECEIVED RAIN THURSDAY AFTERNOON AND EVENING. THE COMBINATION
IS ALLOWING FOG TO FORM (ALREADY 1/4SM FG AT KFWN). THE FOG WAS
HIT A BIT HARDER FOR THE EARLY MORNING UPDATE. AT THIS POINT...WITH
THE AIRMASS SLOWLY MODIFYING....THE FOG SHOULD NOT BE AS DENSE AS
THURSDAY MORNING...NOR SHOULD IT BE AS WIDESPREAD.

THE MID LEVEL SHORT WAVE THAT WILL HELP USHER IN THE AIRMASS
CHANGE IS ABOUT TO DROP INTO THE LONG WAVE TROUGH POSITION OVER
THE FORECAST AREA. WITH SOME INSTABILITY LINGERING...IT IS
POSSIBLE THAT SMALL CONVECTIVE CELLS COULD FORM JUST EAST OF THE
AREA BEFORE ABOUT 0900 UTC...FOSTERED BY FAIRLY STEEP MID LEVEL
LAPSE RATES. THE LATEST HRRR DOES SHOW SOME LIGHT SHOWER ACTIVITY
ACROSS THE SOUTHERN POCONOS AND UPPER LEHIGH VALLEY DURING THE
NEXT COUPLE OF HOURS WITH THE SHORT WAVE...BUT THERE IS NOTHING
UPSTREAM...SO THIS LOOKS OVERDONE. WE WILL CONTINUE THE DRY
FORECAST OVERNIGHT.

NOT MUCH WAS MADE IN THE WAY OF BIG CHANGES TO THE TEMPERATURE AND
WIND FORECASTS OVERNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
ON THURSDAY, HIGH PRESSURE WILL BUILD ACROSS THE EAST COAST, WHILE
SLIGHT RIDGING TAKES PLACE ALOFT. THIS WILL PROVIDE A WARM AND DRY
WEST-NORTHWEST FLOW ACROSS THE AREA. IN FACT, DEWPOINTS MAY MIX DOWN
INTO THE 50S ACROSS MUCH OF THE AREA DURING THE AFTERNOON, AND EVEN
THOUGH TEMPERATURES ARE FORECAST TO RISE INTO THE MID/UPPER 80S,
EVEN AROUND 90 IN SOME AREAS, IT SHOULD FEEL QUITE NICE. WITH MOSTLY
CLEAR SKIES, THE FORECAST WILL REMAIN POP LESS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE UPPER FLOW REMAINS SOMEWHAT FLAT...WITH A SLIGHT TROUGH ACROSS
THE EAST AND A RIDGE OUT WEST. DURING THE LONG RANGE...THE PATTERN
AMPLIFIES WITH A UPPER LOW SPINNING ACROSS HUDSON`S BAY THIS WEEKEND
WHICH WILL WEAKEN EARLY NEXT WEEK. THIS WILL KEEP OUR AREA IN AN
UNSETTLED PATTERN WITHOUT MUCH IN THE WAY OF EXCESSIVELY WARM
TEMPERATURES. IN FACT...TEMPERATURES FROM SATURDAY INTO EARLY NEXT
WEEK WILL BE NORMAL...OR PERHAPS A FEW DEGREES BELOW NORMAL. IT WILL
STILL BE WARM ON FRIDAY...HOWEVER...WITH MID TO UPPER 80S IN MOST
AREAS. A COLD FRONT WILL CROSS THE AREA LATER FRIDAY...BRINGING AN
END TO THE VERY WARM TEMPERATURES.

A FEW THUNDERSTORMS WILL ACCOMPANY THE FRONT FRIDAY AND FRIDAY
NIGHT. MY FORECAST HAS SLOWED THE START TIME FOR THE RAIN A BIT
COMPARED TO THE PREVIOUS FCST...BUT NOT BY MUCH. THE NAM SUGGESTS
THE RAIN WILL BEGIN TOWARDS EVENING...WHILE THE GFS HAS SOME SHOWERS
DEVELOPING AHEAD OF THE FRONT IN NJ FRI MORNING. THE 00Z EC MODEL IS
QUITE A BIT SLOWER...BRINGING THE SHOWERS IN SAT MORNING. WE WILL
OFFER CHC POPS FOR FRI NIGHT INTO SAT...WITH THE SAT ACTIVITY MOSTLY
IN THE MORNING.

FAIR WEATHER RETURNS FOR SAT NIGHT INTO SUNDAY AS HIGH PRESSURE
BUILDS BACK OVER THE AREA. THE REMAINDER OF THE EXTENDED FCST LOOKS
MOSTLY DRY...BUT THE UPPER TROUGH LINGERING TO THE WEST WILL OFFER
SMALL CHCS FOR A FEW SHOWERS AND MAYBE A TSTM MON-TUE. ONLY SLGT CHC
POPS ARE IN THE GRIDS FOR THESE TIME PERIODS ATTM. TEMPERATURES WILL
REMAIN NEAR NORMAL WITH HIGHS MOSTLY IN THE LOW TO MID 80S AND LOWS
IN THE MID 50S TO LOW 60S.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.

MAINLY VFR CONDITIONS CONTINUE EARLY THIS MORNING UNDER MAINLY CLEAR
SKIES. PATCHY MVFR FOG IS EXPECTED (AS IT ALREADY OCCURRING AT
KMIV)...AND THIS SHOULD AFFECT KRDG...KTTN AND KILG BETWEEN 0800 AND
1200 UTC.

VFR CONDITIONS ARE EXPECTED TODAY. A FEW CUMULUS ARE POSSIBLE
ACROSS THE LEHIGH VALLEY AND PORTIONS OF NORTHWEST AND NORTH CENTRAL
NEW JERSEY...OTHERWISE SKIES SHOULD BE CLEAR. A NORTH TO NORTHWEST
FLOW BETWEEN 8 AND 12 KNOTS IS EXPECTED THIS MORNING...AND THE FLOW
SHOULD BEND BACK TO AROUND WEST DURING THE AFTERNOON...WITH WINDS
CLOSER TO 10 KNOTS.

ANY CUMULUS WILL DISAPPEAR EARLY THIS EVENING...OTHERWISE MAINLY VFR
CONDITIONS ARE EXPECTED TONIGHT. LIGHT WINDS MAY ALLOW PATCHY MVFR
FOG TO FORM...BUT COVERAGE OF FOG SHOULD BE LESS THAN THIS MORNING.

OUTLOOK...
FRI...MOSTLY VFR.
FRI NIGHT INTO SATURDAY...MOSTLY VFR WITH SCATTERED SHOWERS/TSTMS.
LOWER CONDITIONS POSSIBLE.
SAT NIGHT INTO MONDAY...MOSTLY VFR.

&&

.MARINE...
CONDITIONS ON THE WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY THROUGH THURSDAY. WINDS WILL SHIFT TOWARD THE NORTHWEST
BEHIND THE COLD FRONT AS IT CROSSES THE WATERS TONIGHT. WINDS MAY
GUST NEAR 15-20 KNOTS FOR A PERIOD TONIGHT, BUT SHOULD REMAIN BELOW
ADVISORY LEVELS.

OUTLOOK...
A COLD FRONT WILL CROSS THE WATERS LATER FRIDAY INTO EARLY
SATURDAY. IT WILL BE ACCOMPANIED BY SCATTERED SHOWERS/TSTMS.
CONDITIONS SHOULD REMAIN SUB-SCA THROUGH THE PERIOD.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...O`HARA
NEAR TERM...HAYES/HEAVENER
SHORT TERM...ROBERTSON
LONG TERM...O`HARA
AVIATION...HAYES/O`HARA
MARINE...ROBERTSON







AREA FORECAST DISCUSSION

NWS MOUNT HOLLY NJ

 1228 AM EDT THU AUG 16 2012

.SYNOPSIS...
A SLOW MOVING FRONTAL SYSTEM AND WEAK LOW PRESSURE ACROSS THE AREA
LATE THIS AFTERNOON WILL MOVE TO THE EAST OVERNIGHT. THIS WILL ALLOW
HIGH PRESSURE FROM THE OHIO VALLEY TO BUILD ACROSS THE REGION. THIS
HIGH WILL REMAIN THROUGH FRIDAY EVENING...BEFORE A COLD FRONT
CROSSES THE AREA. THIS FRONT WILL SLOW DOWN AS IT MOVES OFF THE
COAST SATURDAY. MORE HIGH PRESSURE WILL BUILD OVER THE AREA SATURDAY
NIGHT AND LAST INTO EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE LAST OF THE CONVECTION HAS MOVED OFFSHORE...AND THE INSTABILITY
IS NOT FAR BEHIND. THE SURFACE FRONT HAS CROSSED MUCH OF THE AREA...
BUT THE AIRMASS CHANGE IS STILL BACK OVER WESTERN PENNSYLVANIA.
WINDS ARE FAIRLY LIGHT...AND THE LOW LEVEL REMAIN MOIST...ESPECIALLY
AREAS THAT RECEIVED RAIN THURSDAY AFTERNOON AND EVENING. THE COMBINATION
IS ALLOWING FOG TO FORM (ALREADY 1/4SM FG AT KFWN). THE FOG WAS
HIT A BIT HARDER FOR THE EARLY MORNING UPDATE. AT THIS POINT...WITH
THE AIRMASS SLOWLY MODIFYING....THE FOG SHOULD NOT BE AS DENSE AS
THURSDAY MORNING...NOR SHOULD IT BE AS WIDESPREAD.

THE MID LEVEL SHORT WAVE THAT WILL HELP USHER IN THE AIRMASS
CHANGE IS ABOUT TO DROP INTO THE LONG WAVE TROUGH POSITION OVER
THE FORECAST AREA. WITH SOME INSTABILITY LINGERING...IT IS
POSSIBLE THAT SMALL CONVECTIVE CELLS COULD FORM JUST EAST OF THE
AREA BEFORE ABOUT 0900 UTC...FOSTERED BY FAIRLY STEEP MID LEVEL
LAPSE RATES. THE LATEST HRRR DOES SHOW SOME LIGHT SHOWER ACTIVITY
ACROSS THE SOUTHERN POCONOS AND UPPER LEHIGH VALLEY DURING THE
NEXT COUPLE OF HOURS WITH THE SHORT WAVE...BUT THERE IS NOTHING
UPSTREAM...SO THIS LOOKS OVERDONE. WE WILL CONTINUE THE DRY
FORECAST OVERNIGHT.

NOT MUCH WAS MADE IN THE WAY OF BIG CHANGES TO THE TEMPERATURE AND
WIND FORECASTS OVERNIGHT.

&&

.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM THIS EVENING/...
ON THURSDAY, HIGH PRESSURE WILL BUILD ACROSS THE EAST COAST, WHILE
SLIGHT RIDGING TAKES PLACE ALOFT. THIS WILL PROVIDE A WARM AND DRY
WEST-NORTHWEST FLOW ACROSS THE AREA. IN FACT, DEWPOINTS MAY MIX DOWN
INTO THE 50S ACROSS MUCH OF THE AREA DURING THE AFTERNOON, AND EVEN
THOUGH TEMPERATURES ARE FORECAST TO RISE INTO THE MID/UPPER 80S,
EVEN AROUND 90 IN SOME AREAS, IT SHOULD FEEL QUITE NICE. WITH MOSTLY
CLEAR SKIES, THE FORECAST WILL REMAIN POP LESS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE UPPER FLOW REMAINS SOMEWHAT FLAT...WITH A SLIGHT TROUGH ACROSS
THE EAST AND A RIDGE OUT WEST. DURING THE LONG RANGE...THE PATTERN
AMPLIFIES WITH A UPPER LOW SPINNING ACROSS HUDSON`S BAY THIS WEEKEND
WHICH WILL WEAKEN EARLY NEXT WEEK. THIS WILL KEEP OUR AREA IN AN
UNSETTLED PATTERN WITHOUT MUCH IN THE WAY OF EXCESSIVELY WARM
TEMPERATURES. IN FACT...TEMPERATURES FROM SATURDAY INTO EARLY NEXT
WEEK WILL BE NORMAL...OR PERHAPS A FEW DEGREES BELOW NORMAL. IT WILL
STILL BE WARM ON FRIDAY...HOWEVER...WITH MID TO UPPER 80S IN MOST
AREAS. A COLD FRONT WILL CROSS THE AREA LATER FRIDAY...BRINGING AN
END TO THE VERY WARM TEMPERATURES.

A FEW THUNDERSTORMS WILL ACCOMPANY THE FRONT FRIDAY AND FRIDAY
NIGHT. MY FORECAST HAS SLOWED THE START TIME FOR THE RAIN A BIT
COMPARED TO THE PREVIOUS FCST...BUT NOT BY MUCH. THE NAM SUGGESTS
THE RAIN WILL BEGIN TOWARDS EVENING...WHILE THE GFS HAS SOME SHOWERS
DEVELOPING AHEAD OF THE FRONT IN NJ FRI MORNING. THE 00Z EC MODEL IS
QUITE A BIT SLOWER...BRINGING THE SHOWERS IN SAT MORNING. WE WILL
OFFER CHC POPS FOR FRI NIGHT INTO SAT...WITH THE SAT ACTIVITY MOSTLY
IN THE MORNING.

FAIR WEATHER RETURNS FOR SAT NIGHT INTO SUNDAY AS HIGH PRESSURE
BUILDS BACK OVER THE AREA. THE REMAINDER OF THE EXTENDED FCST LOOKS
MOSTLY DRY...BUT THE UPPER TROUGH LINGERING TO THE WEST WILL OFFER
SMALL CHCS FOR A FEW SHOWERS AND MAYBE A TSTM MON-TUE. ONLY SLGT CHC
POPS ARE IN THE GRIDS FOR THESE TIME PERIODS ATTM. TEMPERATURES WILL
REMAIN NEAR NORMAL WITH HIGHS MOSTLY IN THE LOW TO MID 80S AND LOWS
IN THE MID 50S TO LOW 60S.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
WE SHOULD BE VFR TONIGHT WITH JUST OUR USUAL TERMINALS HAVING SOME
LINGERING MVFR VSBYS EARLY TOMORROW MORNING WITH TODAY`S ADDED
RAIN. IT SHOULD BE NOTED THAT ONLY THE TERMINALS THAT SAW RAIN
TODAY WILL HAVE THESE ISSUES. THOUGH DRIER AIR IS WORKING INTO THE
REGION FROM THE NORTHWEST IT WILL TAKE A WHILE FOR THE NEWLY
ADDED, RAINFALL, MOISTURE TO DRY OUT. HAVE HIT TTN A BIT HARDER IN
TERMS OF VSBYS TONIGHT AND DROPPED THEM TO IFR THROUGH SUNRISE
TOMORROW.

FOG WILL BURN OFF AND VSBYS WILL REBOUND BACK TO VFR BY 14 OR 15Z
EVERYWHERE WHILE THE SKIES WILL REMAIN CLEAR. WINDS WILL SHIFT
MORE TOWARDS THE NORTHWEST BY DAYBREAK AND THEN MORE TOWARDS THE
WEST BY THE MID-AFTERNOON, ALL REMAINING UNDER 10 KNOTS.

OUTLOOK...
THU NIGHT INTO FRI...MOSTLY VFR.
FRI NIGHT INTO SATURDAY...MOSTLY VFR WITH SCATTERED SHOWERS/TSTMS.
LOWER CONDITIONS POSSIBLE.
SAT NIGHT INTO MONDAY...MOSTLY VFR.

&&

.MARINE...
CONDITIONS ON THE WATERS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY THROUGH THURSDAY. WINDS WILL SHIFT TOWARD THE NORTHWEST
BEHIND THE COLD FRONT AS IT CROSSES THE WATERS TONIGHT. WINDS MAY
GUST NEAR 15-20 KNOTS FOR A PERIOD TONIGHT, BUT SHOULD REMAIN BELOW
ADVISORY LEVELS.

OUTLOOK...
A COLD FRONT WILL CROSS THE WATERS LATER FRIDAY INTO EARLY
SATURDAY. IT WILL BE ACCOMPANIED BY SCATTERED SHOWERS/TSTMS.
CONDITIONS SHOULD REMAIN SUB-SCA THROUGH THE PERIOD.

&&

.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...O`HARA
NEAR TERM...HAYES
SHORT TERM...ROBERTSON
LONG TERM...O`HARA
AVIATION...HEAVENER/ROBERTSON/O`HARA
MARINE...ROBERTSON







AREA FORECAST DISCUSSION

NWS TAMPA BAY RUSKIN FL

 725 PM EDT FRI AUG 17 2012

.UPDATE (TONIGHT - SATURDAY)...
23Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A NOW AMPLIFIED UPPER
LEVEL PATTERN IN PLACE OVER THE CONUS CONSISTING OF LONGWAVE RIDGING
ALONG THE PACIFIC COAST/INTER-MOUNTAIN WEST...FOLLOWED DOWNSTREAM BY
LONGWAVE TROUGHING OVER MUCH OF THE CENTRAL/EASTERN STATES. THE
BASE OF THIS TROUGH EXTENDS ALL THE WAY SOUTH TO THE NE GULF
COAST...AND WE HAVE SEEN OUR HEIGHTS DROP A FEW DM IN THE PAST 24
HOURS AS THE UPPER RIDGE WAS SUPPRESSED. A SERIES OF
IMPULSES/SHORTWAVES HAVE BEEN ROUNDING THE BASE OF THIS TROUGH
ACROSS NORTH FLORIDA TODAY...AND LOOKS LIKE AT LEAST ONE MORE PIECE
OF ENERGY WILL BE INFLUENCING OUR WEATHER DURING THE OVERNIGHT INTO
EARLY SATURDAY MORNING.

AT THE SURFACE...THE SUBTROPICAL RIDGE AXIS HAS ALSO BEEN SUPPRESSED
SOUTHWARD AND NOW LIES OVER FAR SOUTH FL/FLORIDA STRAITS. THIS
POSITION IS PROVIDING OUR REGION WITH A MOIST SW/W LOW LEVEL FLOW.
TYPICAL OF THIS TYPE OF FLOW...THE MAJORITY OF THE DIURNAL
CONVECTION OCCURRED EARLY IN THE DAY AND HAS SENSE PROGRESSED OVER
TO AND OFF THE EASTERN FL SEABOARD. IN FACT...THE INITIAL PUSH OF
CONVECTION ENDED EARLY ENOUGH TO ALLOW TEMPERATURES TO WARM BACK UP
OVER NORTHERN PORTIONS OF THE FORECAST AREA WHERE AMPLE SUNSHINE
RETURNED. FURTHER SOUTH THE CLOUDS WERE MORE STUBBORN AND KEPT
TEMPERATURES COOLER. ACTUALLY NOW SEEING A FEW STORMS REDEVELOP OVER
THE CENTRAL INTERIOR ZONES ALONG THIS THERMAL GRADIENT.

SOME CHANGES HAVE BEEN MADE TO THE FORECAST FOR LATER TONIGHT INTO
EARLY SATURDAY MORNING...ESPECIALLY FOR COASTAL ZONES FROM TAMPA BAY
NORTHWARD. THE W/SW LOW LEVEL FLOW IS ALREADY A CLIMATOLOGICALLY
FAVORED FLOW FOR NOCTURNAL MARINE CONVECTION TO MIGRATE BACK TOWARD
LAND...HOWEVER TONIGHT WE WILL ALSO SEE THE APPROACH OF A WEAK
SHORTWAVE TROUGH FROM THE NORTHWEST. EVEN THIS WEAK SYNOPTIC SUPPORT
FOR LIFT SHOULD BE ENOUGH TO TRIGGER SCT/NMRS SHOWERS AND STORMS
OVER THE WATER. NATIONAL AND LOCAL HIGH-RESOLUTION ENSEMBLE MEMBERS
ARE IN AGREEMENT SHOWING DECENT CONVECTIVE COVERAGE RETURNING TO THE
NATURE COAST AFTER MIDNIGHT AND EVEN DOWN INTO THE TAMPA BAY AREA
LATE AT NIGHT/EARLY SATURDAY MORNING. THIS PATTERN IS SHARED BY MOST
OF THE LARGER SCALE GUIDANCE MEMBERS AS WELL. HAVE INCREASED THE
POPS OVER THESE AREAS TO REPRESENT THIS MODEL CONSENSUS. 25KT SPEED
MAX WITHIN THE STEERING LEVELS AHEAD OF THE SHORTWAVE SHOULD KEEP
ANY CONVECTION ON THE MOVE...SO NOT EXPECTING LONG DURATIONS OF
RAINFALL...HOWEVER THE ENVIRONMENT CERTAINLY SUGGEST HIGHER POPS
THAN THE MAV MOS NUMBERS.

SATURDAY WILL BE A DIFFICULT FORECAST...AS CONVECTIVE MORNING
COVERAGE WILL BE DEPENDENT ON WHERE/WHEN THE OVERNIGHT STORMS
OCCUR. WOULD APPEAR THE BEST CHANCES FOR SHOWERS AND STORMS DURING
THE MORNING WILL BE FROM HERNANDO COUNTY SOUTHWARD TO TAMPA BAY.
SHORTWAVE ENERGY PASSES EAST OF THE REGION BY THE EARLY AFTERNOON
ALLOWING WEAK NVA IN ITS WAKE. THIS NVA PATTERN MAY ACTUALLY BE
ENOUGH TO SUPPRESS SOME OF THE AFTERNOON CONVECTIVE COVERAGE. WILL
HAVE TO MONITOR THE PROGRESS OF THIS FEATURES BEFORE MAKING ANY
SIGNIFICANT CHANGES TO THE SATURDAY AFTERNOON FORECAST.

&&

.PREVIOUS DISCUSSION (SAT NIGHT - SUNDAY)...
DURING SATURDAY NIGHT INTO SUNDAY SURFACE AND MID LEVEL RIDGING WILL
LIFT BACK TO THE NORTH SOME. AMPLE MOISTURE AND INSTABILITY WILL
SUPPORT SCATTERED DIURNAL SEA BREEZE DRIVEN SHOWERS AND STORMS
ACROSS THE REGION WITH A SOUTHWEST TO WEST STEERING FLOW FAVORING
HIGHEST POPS (40 PERCENT) OVER INLAND LOCATIONS DURING THE AFTERNOON
AND EARLY EVENING HOURS. IT WILL REMAIN QUITE MUGGY WITH
TEMPERATURES CLIMBING INTO THE UPPER 80S ALONG THE COAST AND LOWER
TO MID 90S INLAND WITH OVERNIGHT LOWS IN THE 70S...EXCEPT AROUND 80
ALONG THE IMMEDIATE COAST DUE TO THE ONSHORE FLOW.

&&

.AVIATION...
VFR THROUGH 06Z OR SO THEN INCREASING SHRA/TSRA OVER GULF COULD
BEGIN TO IMPACT NORTHERN TAF SITES...ESPECIALLY TPA AND PIE. WILL
SHOW TEMPO TSRA THOSE SITES 09Z TO 12Z BUT ACTIVITY COULD LINGER
THROUGH 15Z BEFORE MOVING INLAND. WILL HANDLE REMAINDER OF TAF
SITES WITH VCTS AS COVERAGE SHOULD BE LOWER TO THE SOUTH AND EAST.

&&

.MARINE...
SURFACE HIGH PRESSURE ACROSS THE SOUTHERN PENINSULA WILL MEANDER
BACK NORTH TO THE CENTRAL PENINSULA LATE IN THE WEEKEND AND INTO
EARLY NEXT WEEK. A WEAK PRESSURE PATTERN UNDER THE HIGH WILL KEEP
LIGHT WINDS AND LOW SEAS OVER THE GULF WATERS THROUGH THE PERIOD
WITH AN ENHANCED ONSHORE SEA BREEZE COMPONENT DEVELOPING ALONG THE
COAST EACH AFTERNOON.

&&

.PRELIMINARY POINT TEMPS/POPS...
TPA  77  91  78  91 /  50  60  20  30
FMY  76  93  76  93 /  20  30  20  30
GIF  76  93  76  93 /  20  40  20  40
SRQ  77  91  77  91 /  40  50  20  30
BKV  72  93  73  92 /  50  60  20  30
SPG  81  91  80  91 /  50  60  20  30

&&

.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.

&&

$$

UPDATE...MROCZKA
PREVIOUS DISCUSSION...MCMICHAEL
AVIATION...JILLSON







AREA FORECAST DISCUSSION

NWS MELBOURNE FL

 1014 AM EDT THU AUG 16 2012

.DISCUSSION...
ATLC RIDGE AXIS EXTENDING FROM THE NRN BAHAMAS INTO THE E GOMEX WILL
INTERACT WITH A FRONTAL TROF OVER THE ERN CONUS TO MAINTAIN A DEEP
BUT LIGHT WRLY FLOW ACRS CENTRAL FL...LATEST RAP ANALYSIS SHOWS BOTH
H100-H70 AND H85-H50 WINDS AOB 10KTS ACRS CENTRAL FL. THIS WILL
ALLOW BOTH SEA BREEZES TO FROM BY EARLY AFTN...BUT WILL NOT PROMOTE
RAPID INLAND MOVEMENT ON EITHER SIDE OF THE PENINSULA.

MORNING SOUNDINGS SHOW PWAT VALUES HAVE INCREASED OVER THE PAST
24HRS...NOW ARND 2.0" ACRS THE PENINSULA...MOISTURE PROFILE IS VERY
SIMILAR WITH MUCH OF THE MOISTURE BLO H70 AND GRADUAL DRYING ABV
H70. SFC DEWPOINTS IN THE M70S AREAWIDE WILL MAKE FOR ANOTHER SULTRY
DAY ACRS THE AREA. MID LVL CAPS ARE ABSENT...ONLY THE SHALLOW
NOCTURNAL SFC INVERSIONS WERE NOTED AND THOSE HAVE BURNED OFF BY
NOW. H85-H70 LAPSE RATES BTWN 6.0-7.0C/KM ARE RESPECTABLE...BUT THE
H85-H50 VALUES BLO 6.0C/DM ARE NOT. DEEP LYR VORT FIELDS REMAIN
QUITE WEAK WHILE UPR LVL DIV FIELDS ARE NEUTRAL OR WEAKLY
CONVERGENT.

SIMILAR WX PATTERN TO YESTERDAY. THE DEEP LYR MOISTURE PROFILE WILL
ALLOW SCT SHRAS/TSRAS TO DVLP AREAWIDE. HOWEVER...WEAK MID/UPR LVL
DYNAMIC SUPPORT WILL TEND TO SUPPRESS DIURNAL CONVECTION OUTSIDE OF
THE IMMEDIATE VICINITY OF THE SEABREEZE/LAKE BREEZE BOUNDARIES.
COVERAGE WILL INCREASE THRU LATE AFTN/EARLY EVNG AS SFC TEMPS WARM
INTO THE L/M90S AND THE SEA BREEZES INTERACT WITH OTHER MESOSCALE
BOUNDARIES. DRIER AIR ALOFT WILL INCREASE THE POTENTIAL FOR STRONG
DOWNBURSTS.

WILL UPDATE FCST TO MENTION EARLIER FORMATION OF TSRAS ALONG THE SEA
BREEZE ON THE EAST SIDE OF LAKE OKEECHOBEE...NO OTHER CHANGES
NECESSARY.

&&

.AVIATION...
THRU 16/17Z...VFR ALL SITES...SFC WNDSHFT FM W/SW TO E/NE AOB 12KTS
CSTL SITES ASSOCD WITH THE EAST COAST SEA BREEZE...ISOLD MVFR SHRAS
S OF KVRB. BTWN 16/17Z-16/20Z...SFC WNDSHFT FM W/SW TO S/SE INTERIOR
SITES AS THE SEA BREEZE STALLS W OF I-95...SCT MVFR SHRAS/ISOLD
TSRAS S OF KVRB AND W OF KLEE-KOBE MVG E/NE 5-10KTS. BTWN
16/20Z-16/24Z...SCT IFR/ISOLD LIFR TSRAS N OF KOBE-KVRB AS THE E/W
COAST SEA BREEZES INTERACT. BTWN 17/00Z-17/03Z...SCT MVFR
SHRAS/ISOLD TSRAS N OF KISM-KTIX...VFR ELSEWHERE. AFT 17/03Z...VFR
ALL SITES.

&&

.MARINE...
NO HIGHLIGHTS...NO SIG CHANGES. BROAD RIDGE AXIS OVER S FL WILL
MAINTAIN A WEAK SFC PGRAD AREAWIDE. GENTLE TO MODERATE SFC/BNDRY LYR
WINDS WILL SHIFT FROM W/SW TO E/NE NEAR THE COAST THRU EARLY AFTN AS
THE EAST COAST SEA BREEZE DVLPS AND DRIFTS INLAND. SEAS AOB 2FT
NEARSHORE AND 2-3FT OFFSHORE. SCT TSRAS MOVING OFFSHORE LATE
AFTN/EARLY EVNG...MORE NUMEROUS N OF PORT CANAVERAL.

&&

.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.

&&

$$

FORECAST/AVIATION...BRAGAW
RADAR/IMPACT WX.....LASCODY













AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 931 PM EDT FRI AUG 17 2012

.SYNOPSIS...
AN INLAND TROUGH OF LOW PRESSURE WILL PREVAIL THROUGH FRIDAY.
A COLD FRONT WILL APPROACH FROM THE NORTH SATURDAY AND STALL ACROSS
NORTHERN SOUTH CAROLINA SATURDAY NIGHT INTO SUNDAY. THE FRONT WILL
LINGER TO THE NORTH THROUGH EARLY NEXT WEEK BEFORE SHIFTING
OFFSHORE.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
DEEP CONVECTION OVER THE FORECAST AREA HAS DIMINISHING THIS EVENING.
KCHS SOUNDING AT 00Z INDICATES AN AIR MASS THAT HAS BEEN WORKED OVER
BY EARLIER TSTMS...INSTABILITY FEEBLE. LATEST RUC SHOWS A THIN
AXIS OF INSTABILITY RUNNING N TO S FROM AIKEN SC TO WAYCROSS GA.
RADAR TRENDS HOWEVER SHOW CONVECTION DECREASING IN THIS AXIS.
ATTENTION TURNS TO THE ACTIVE DEEP CONVECTION IN THE SOUTH
CAROLINA MIDLANDS. WEAK UPPER DIFLUENCE/UPPER WAVE AND A PRE-FRONTAL
TROUGH KEEPING THIS AREAS ACTIVE AND LATEST GUIDANCE SUGGEST MOST
OF THIS ACTIVITY WILL SWING INTO THE PEE DEE REGION BY LATER
TONIGHT BEFORE WEAKENING. FOR OUR FORECAST WE HAVE LEFT 20-30 POPS
GOING ALL LOCATIONS OVERNIGHT GIVEN THE MID LEVEL SHORT WAVE STILL
PROGGED TO PASS INTO THE AREA.

LOW TEMPS WILL BE IN THE LOWER 70S MOST AREAS...EXCEPT MID 70S
CLOSER TO THE COAST. THE POTENTIAL FOR PATCHY FOG HAS INCREASED
FOR LATER TONIGHT GIVEN THE MORE WIDESPREAD RAINFALL THIS
AFTERNOON...BUT CONFIDENCE NOT HIGH ENOUGH TO INCLUDE IN FORECAST
AT THIS TIME.

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
SATURDAY...A COLD FRONT WILL SAG SOUTH INTO THE SOUTH CAROLINA
MIDLANDS AND PEE DEE SATURDAY AFTERNOON IN RESPONSE TO SHORTWAVE
ENERGY DIGGING ACROSS THE EASTERN OHIO VALLEY AND CENTRAL
APPALACHIANS. THE EVOLUTION OF CONVECTION IS RATHER UNCERTAIN WITH
MODELS SHOWING A POTENTIAL FOR SOME FAIRLY SIGNIFICANT LOWER MID-
LEVEL THETA AIR ADVECTING INTO THE REGION AHEAD OF THE FRONT
DURING PEAK HEATING. THE LATEST NAM IS THE MOST AGGRESSIVE WITH
THE MID-LEVEL DRYING WHILE THE SIGNALS IN THE GFS/ECMWF ARE NOT AS
PRONOUNCED. THE EVENTUAL COVERAGE OF SHOWERS/TSTMS WILL BE CLOSELY
TIED TO THIS GIVEN THE LACK OF SIGNIFICANT UPPER FORCING. PLAN TO
LOWER POPS SLIGHTLY TO 20-40 PERCENT GIVEN THE LATEST MODEL TRENDS
WITH THE HIGHEST GRIDDED POPS PLACED ACROSS THE INTERIOR AND FAR
NORTHERN ZONES WHICH WILL BE CLOSEST TO THE COLD FRONT ITSELF.
CONVERGE MAY BE MORE LIMITED ACROSS SOUTHEAST GEORGIA WHERE
CONVECTION WILL BE PRIMARY CLUSTERED ALONG THE SEA BREEZE AND
VARIOUS CONVECTIVE OUTFLOWS.

MODIFIED SOUNDINGS SHOW MODEST INSTABILITY WILL BE IN PLACE WITH
FAIRLY WEAK SHEAR PROFILES. 0-6KM BULK SHEAR IS FORECAST TO INCREASE
TO 20-25 KT BY LATE AFTERNOON ACROSS THE CHARLESTON TRI-COUNTY
WHICH MAY PROVIDE ENOUGH SUPPORT FOR MORE ORGANIZE MULTI-CELLULAR
CLUSTERS...ESPECIALLY IF MESOSCALE BOUNDARY INTERACTIONS OCCUR. THE
SPC DAY 2 SEVERE WEATHER OUTLOOK GUIDANCE PRODUCT CURRENTLY
HIGHLIGHTS THE NORTHERN PARTS OF THE FORECAST AREA IN A SLIGHT RISK
FOR SEVERE TSTMS...BUT CURRENT DATA SUGGEST THE GREATEST RISK FOR
ORGANIZED SEVERE WEATHER WILL BE DISPLACED FARTHER TO NORTH AND
NORTHEAST WHERE SHEAR PROFILES WILL BE THE STRONGEST. THE RISK FOR
ORGANIZED SEVERE WEATHER LOOKS TOO MARGINAL TO INCLUDE A MENTION IN
THE HAZARDOUS WEATHER OUTLOOK ATTM. HOPEFULLY...THE NEXT FEW MODELS
RUNS WILL YIELD A CLEARER PICTURE ON HOW CONVECTION WILL EVOLVE.

SUNDAY...SCATTERED SHOWERS/TSTMS ARE EXPECTED DURING THE AFTERNOON/
EARLY EVENING HOURS AS A RATHER POTENT SOUTHERN STREAM SHORTWAVE
CROSSES THE REGION DURING PEAK HEATING. A STATIONARY FRONT TO THE
NORTH...LINGERING CONVECTIVE OUTFLOWS FROM TSTMS SATURDAY AS WELL AS
THE AFTERNOON SEA BREEZE CIRCULATION WILL THE PRIMARY FOCI FOR
CONVECTIVE DEVELOPMENT. SOUNDINGS SHOW MODEST SBCAPE...BUT
CONSIDERABLE CLOUD COVER WILL LIMIT OVERALL INSTABILITY SOMEWHAT.
0-6KM BULK SHEAR ON THE ORDER OF 15-20 KT COULD SUPPORT A FEW SEVERE
MULTI-CELLULAR CLUSTERS A FEW OF WHICH COULD BECOME SEVERE. AN
ORGANIZED SEVERE EVENT IS UNLIKELY ATTM. GRIDDED POPS OF 40-50 PCNT
LOOK REASONABLE DURING THIS TIME FRAME...BUT HIGHER POPS MAY
EVENTUALLY BE NEEDED.

MONDAY...ANOTHER ROUND OF SCATTERED SHOWERS/TSTMS IS EXPECTED AS A
PLETHORA OF IMPULSES ROUNDING THE BASE OF THE LONG-WAVE TROUGH
TRAVERSE THE REGION AND INTERACTS WITH INCREASING TROPICAL
MOISTURE...LIKELY ASSOCIATED WITH THE REMNANTS OF TROPICAL
DEPRESSION 7 IN THE BAY OF CAMPECHE. WILL CAP POPS AT 40
PERCENT...BUT HIGHER POPS MAY BE NEEDED AS TEMPORAL AND SPATIAL
DETAILS BECOME MORE CERTAIN.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE UPPER TROUGH WILL REMAIN ANCHORED ACROSS THE EASTERN HALF OF THE
UNITED STATES THROUGH MID WEEK. INITIALLY A STALLED COLD FRONT WILL
REMAIN OFFSHORE BEFORE PULLING AWAY FROM THE AREA AROUND WEDNESDAY.
THE UPPER TROUGH WILL BEGIN TO WEAKEN THEREAFTER...BUT MODELS STILL
SHOW A SERIES OF WEAK DISTURBANCES SWINGING ACROSS THE AREA.
OVERALL...EXPECT ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS
THROUGH THE EXPENDED PERIOD...ESPECIALLY DURING THE TRADITIONAL
AFTERNOON HOURS. SLIGHTLY BELOW NORMAL TEMPERATURES ARE ALSO
EXPECTED TO CONTINUE WITH HIGHS IN THE UPPER 80S AND LOWS POSSIBLY
DIPPING INTO THE MID TO UPPER 60S.

&&

.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
WILL MONITOR THE POTENTIAL FOR PATCHY FOG LATER TONIGHT...ESPECIALLY
IF MID AND HIGH CLOUDS DISSIPATE OVER THE REGION LATE. ISOLATED
SHOWERS AND TSTMS ARE POSSIBLE AFTER 18Z ON SAT. AT THIS TIME...
KCHS APPEARS TO STAND A BIT BETTER CHANCE FOR LATE DAY THUNDER
ON SAT.

EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE OF SOME LOW CLOUDS
AROUND EACH MORNING THROUGH THE WEEKEND...POSSIBLY ENOUGH TO LOWER
CIGS TO MVFR FOR AN HOUR OR TWO. OTHERWISE...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY DURING THE AFTERNOON/EVENING HOURS...COULD
RESULT IN TEMPORARY REDUCTIONS IN CIGS/VSBYS THIS WEEKEND.

&&

.MARINE...
NO HIGHLIGHTS EXPECTED THROUGH TONIGHT. A TROUGH OF LOW PRESSURE
WILL REMAIN INLAND WITH AN ATLANTIC RIDGE CENTERED WELL SOUTHEAST
OF THE REGION. A FEW SHOWERS AND THUNDERSTORMS COULD DEVELOP
AGAIN LATER TONIGHT. WINDS ARE EXPECTED TO REMAIN GENERALLY 15 KT
OR LESS AND SEAS 3 FEET OR LESS THROUGH TONIGHT. WINDS MAY BRIEFLY
SURGE TO 15-20 KT LATER TONIGHT OVER THE SC WATERS. HOWEVER...DUE
TO A RELATIVELY SHORT DURATION AND UNCERTAINTY IN THE FORECAST FOR
THIS SURGE TO OCCUR...HAVE KEPT OUT OF FORECAST FOR NOW.

A COLD FRONT WILL APPROACH FROM THE NORTHWEST THROUGH THE
WEEKEND...BEFORE STALLING JUST OFF THE SOUTHEAST COAST BY THE MIDDLE
OF NEXT WEEK. OVERALL...A SOUTH-SOUTHWEST FLOW IS GENERALLY EXPECTED
EACH DAY...WITH THE FLOW VEERING OFFSHORE DURING THE NIGHTTIME/EARLY
MORNING HOURS. GENERALLY BRIEF SURGES UPWARDS OF 15-20 KT WILL
OCCUR AT TIMES...ESPECIALLY SUNDAY THROUGH MONDAY NIGHT AS THE
PRESSURE GRADIENT TIGHTENS IN ASSOCIATION WITH THE APPROACHING
COLD FRONT.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...JHP
AVIATION...
MARINE...RFM







AREA FORECAST DISCUSSION

NWS CHARLESTON SC

 353 PM EDT THU AUG 16 2012

.SYNOPSIS...
AN INLAND TROUGH OF LOW PRESSURE WILL PREVAIL THROUGH FRIDAY.
ANOTHER WEAK COLD FRONT WILL APPROACH FROM THE NORTHWEST SATURDAY
BEFORE STALLING JUST NORTH AND WEST OF THE AREA ON SUNDAY AS A
WEAK WAVE OF LOW PRESSURE FORMS ALONG THE FRONT. THE FRONT IS
EXPECTED TO SHIFT ACROSS THE AREA EARLY NEXT WEEK...THEN LINGER
JUST OFFSHORE INTO THE MIDDLE OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE CONVECTION HAS CERTAINLY TAKEN OFF OVER OUR SOUTHERN AND
CENTRAL COASTAL REGION...SPARKED BY LOW LEVEL BOUNDARY COLLISIONS
AND A WEAK UPPER LEVEL SHORT WAVE MOVING ACROSS CENTRAL GA. HAVE
INCREASED POPS...BUT CONVECTION IS CHANGING IN COVERAGE SO
RAPIDLY...IT IS NEARLY IMPOSSIBLE TO GET THE POPS ALIGNED WITH
REALITY. HAVE ALREADY RECEIVED SEVERAL REPORTS OF LARGE HAIL WITH
THE STORMS AROUND THE SAVANNAH RIVER REGION. EXPECT STORMS TO
PROPAGATE NORTHWARD ALONG SEA BREEZE...WHICH IS PINNED VERY CLOSE
TO THE COAST. HOWEVER...NOT THINKING THE STORMS THAT DEVELOP
FURTHER NORTH WILL BE QUITE AS STRONG AS THE MORE SOUTHERN ONES
DUE TO LOWER CAPE VALUES. HOWEVER...LATEST RUC ANALYSES INDICATING
30-40 KTS OF BULK SHEAR NEAR THE COAST...WHICH COULD ALLOW
ORGANIZED UPDRAFTS AND LONGER LASTING STORMS MOVING UP THE COAST.

SCATTERED STORMS...WHICH SHOULD STAY CONFINED TO MAINLY THE
COASTAL THIRD OF THE REGION...WILL DISSIPATE BY THE EVENING...BUT
LIKELY LINGER OVER THE COASTAL WATERS WELL INTO THE EVENING. MIN
TEMPS GENERALLY IN THE LOWER TO MID 70S.

SOME GUIDANCE INDICATING MUCH MORE CLOUD COVER TONIGHT THAN
CURRENTLY ADVERTISED. WE DID BUMP CLOUD COVER UP FROM THE PREVIOUS
FORECAST...BUT IT MAY NEED TO BE ADJUSTED HIGHER. THERE MAY ALSO
NOW BE A THREAT FOR SOME FOG LATER TONIGHT AND EARLY FRIDAY
MORNING WITHIN AREAS THAT RECEIVED RAIN. HOWEVER...CONFIDENCE TOO
LOW TO MENTION IN FORECAST AT THIS TIME.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
THINK FRIDAY WILL BE QUIET THROUGH MID DAY AS A WEAK AREA OF
SUBSIDENCE MOVES THROUGH. THE SUBSIDENCE MAY ALLOW FOR A LOW CLOUD
DECK FOR A FEW HOURS IN THE EARLY MORNING HOURS...GRADUALLY
BREAKING UP BY MID DAY. I HAVE GONE JUST A TOUCH BELOW MAX TEMP
GUIDANCE BASED ON THE THINKING THAT THE CLOUDS MAY KEEP TEMPS DOWN
A SMIDGE BEFORE NOON. HOWEVER...THERE SHOULD BE PLENTY OF SUNSHINE
AROUND BY AFTERNOON...WITH JUST A FEW ISOLATED THUNDERSTORMS
POSSIBLE NEAR THE SEA BREEZE.

LATER IN THE DAY...THE LEE TROF WILL GET A LITTLE BOOST FROM A WEAK
SHORTWAVE AND BE A FOCUS FOR LATE DAY CONVECTION OVER INLAND
AREAS...PROBABLY LASTING INTO THE EVENING HOURS IN A FEW PLACES.

ON SATURDAY...CLOUDS AND AFTERNOON/EVENING THUNDERSTORMS WILL
INCREASE IN COVERAGE AS A RATHER ROBUST UPPER TROF SETS UP OVER THE
EASTERN HALF OF NORTH AMERICA. THE FRONT APPROACHING FROM THE
NORTHWEST WILL STALL OVER THE UPSTATE AS A WEAK AREA OF LOW PRESSURE
FORMS ALONG THE FRONT...GIVING US MOIST AND DEEP SOUTHWESTERLY FLOW.
PWS WILL INCREASE TO NEAR 2 INCHES...AND THE CYCLONIC FLOW ALOFT
WILL PROVIDE SUPPORT FOR DIURNAL CONVECTION ALONG ANY BOUNDARIES
THAT FORM.

THINGS WILL BE EVEN MORE UNSETTLED ON SUNDAY AS THE UPPER JET
STRETCHES OUT TO OUR NORTHWEST FROM THE LOWER MISSISSIPPI VALLEY ALL
THE WAY TO NEW ENGLAND. PWS SHOULD GO UP OVER 2 INCHES BY THEN...AND
THE SYNOPTIC LIFT WILL BE STRONGER. ONLY FACTOR THAT MAY HOLD BACK
CONVECTION IN A FEW PLACES IS THE LACK OF STRONG INSTABILITY AS
CLOUDS WILL KEEP MAXIMUM TEMPS DOWN A FEW DEGREES FROM SATURDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT INDICATING AN UNSETTLED
PATTERN FOR MOST OF THE LONG TERM PERIOD WITH BROAD UPPER LEVEL
TROUGHING PERSISTING ACROSS THE EASTERN UNITED STATES THROUGH THE
MIDDLE OF NEXT WEEK. WHILE MODELS DIFFER SLIGHTLY WITH THE POSITION
OF A COLD FRONT ALONG THE SOUTHEAST COAST...THEY GENERALLY SUGGEST
THE FRONT SLOWLY SHIFTING ACROSS THE AREA ON MONDAY THEN STALLING
JUST OFFSHORE INTO THE MIDDLE OF NEXT WEEK. THE GREATEST CHANCES FOR
PRECIPITATION APPEAR TO BE EARLY IN THE WEEK WITH AN AXIS OF DEEP
MOISTURE OVER THE AREA AND THE FRONT PASSING THROUGH...BUT COULD
DIMINISH SOME TOWARD THE MIDDLE OF NEXT WEEK DEPENDING ON HOW FAR
OFFSHORE THE FRONT AND ASSOCIATED DEEP MOISTURE GET. OVERALL...THE
FORECAST WILL MAINTAIN A CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH
THE LONG TERM PERIOD. SLIGHTLY BELOW NORMAL TEMPERATURES ARE
EXPECTED THROUGH THE LONG TERM PERIOD.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
CONVECTION HAS BLOSSOMED QUICKLY OVER KSAV DUE TO MULTIPLE
BOUNDARY COLLISIONS AND THE PRESENCE OF A WEAK UPPER LEVEL SHORT
WAVE. BRIEF PERIODS OF MVFR POSSIBLE THROUGH THE REST OF THE
AFTERNOON...THEN EXPECT A RETURN TO MAINLY VFR BY THIS EVENING.
CONVECTION STILL POSSIBLE AT KCHS...BUT COVERAGE EXPECTED TO BE
LESS THAN AROUND KSAV AND TIMING...IF IT OCCURS...WILL BE LATE
AFTERNOON AND EVENING. HAVE CONTINUED TO LEAVE OUT PRECIP MENTION
FOR KCHS GIVEN LOW PROBABILITIES OF IT HITTING THE TERMINAL...BUT
WILL CLOSELY MONITOR.

TONIGHT...VFR EXPECTED TO PREVAIL FOR MUCH OF THE NIGHT.
HOWEVER...STILL CONCERNED ABOUT A POTENTIAL FOR LOWER
CIGS...POSSIBLY MVFR/IFR FOR BOTH SITES MAINLY AFTER 08Z TONIGHT.
ALSO...GIVEN THE CONVECTION THIS AFTERNOON AND EVENING...FOG IS
MORE OF A POSSIBILITY...ESPECIALLY FOR KSAV. WILL NEED TO ADDRESS
THE FOG POTENTIAL WITH LATER UPDATES.

EXTENDED AVIATION OUTLOOK...THERE IS A CHANCE OF SOME LOW CLOUDS
AROUND EACH MORNING THROUGH THE WEEKEND...POSSIBLY ENOUGH TO LOWER
CIGS TO MVFR FOR AN HOUR OR TWO. OTHERWISE...SCATTERED SHOWERS AND
THUNDERSTORMS...MAINLY DURING THE AFTERNOON/EVENING HOURS...COULD
RESULT IN TEMPORARY REDUCTIONS IN CIGS/VSBYS THIS WEEKEND.

&&

.MARINE...
A WEAK SURFACE FRONT REMAINS STALLED INLAND THROUGH THIS EVENING.
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE ALONG
THE COASTAL WATERS THROUGH THIS EVENING. SOME OF THESE STORMS
COULD BE STRONG WITH GUSTY WINDS NEAR 35 KTS AND SMALL HAIL.
ISOLATED SHOWERS AND THUNDERSTORMS WILL GRADUALLY TAPPER OFF LATER
TONIGHT. WINDS LESS THAN 15 KTS AND SEAS 3 FT OR LESS WILL PERSIST
THROUGH TONIGHT.

AFTER A RELATIVELY QUIET FRIDAY...A COLD FRONT WILL APPROACH FROM
THE NORTHWEST THROUGH THE WEEKEND...BEFORE STALLING JUST OFF THE
SOUTHEAST COAST EARLY NEXT WEEK. OVERALL...A SOUTH-SOUTHWEST FLOW
IS GENERALLY EXPECTED EACH DAY...WITH THE FLOW VEERING OFFSHORE
DURING THE NIGHTTIME/EARLY MORNING HOURS BY NEXT WEEK. BRIEF
SURGES UPWARDS OF NO MORE THAN 15-20 KT COULD OCCUR AT TIMES...BUT
WIND AND SEA CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
CRITERIA THROUGH THE PERIOD.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...
NEAR TERM...RFM
SHORT TERM...ALSHEIMER
LONG TERM...JAQ
AVIATION...BDC/RFM
MARINE...ALSHEIMER/RFM







AREA FORECAST DISCUSSION

NWS NORTHERN INDIANA

 111 PM EDT THU AUG 16 2012

.AVIATION...

18Z TAF

REMNANT CONVECTION FROM THE MCC CONTINUES TO SHIFT EASTWARD. WAKE
PRECIPITATION SHIELD SHOWING SIGNS OF ERODING FROM THE WEST. SPEED
MAX AROUND 600MB HAS SHOWN UP ON THE PROFILER AND RADAR VWP...AS
WELL AS WATER VAPOR IMAGERY OVER SOUTHERN IA-CENTRAL IL. THIS JET
HAS BEEN THE FOCUS FOR RENEWED CONVECTIVE DEVELOPMENT IN CENTRAL
IL. EXPECT TO SEE A LINE OF CONVECTION FORMING FROM MONTICELLO
INDIANA-AUBURN INDIANA TO MONTPELIER OHIO FROM 20-22Z. INCREASED
SHEAR AND INSTABILITY WOULD FAVOR QLCS SEVERE POTENTIAL...
ESPECIALLY FOR THE KFWA TERMINAL.

CONVECTION TO MOVE QUICKLY OUT OF THE FORECAST AREA AFTER 03Z AND
SHOULD BE ENOUGH MOISTURE AND CLEARING TO SUPPORT PATCHY FOG
FORMATION BEFORE DAYBREAK.

&&

.PREV DISCUSSION... /ISSUED 633 AM EDT THU AUG 16 2012/

AVIATION...(12Z TAF ISSUANCE) COLD FRONT OVER WI-IA WILL MOVE
SOUTHEAST ACROSS NORTHERN INDIANA THIS AFTN/EVE. TSRA ALONG/AHEAD
OF THE FRONT ATTM MAY WEAKEN THIS MORNING BUT EXPECT RE-
DEVELOPMENT/INTENSIFICATION AS THE FRONT APPROACHES THE AREA THIS
AFTN. MOVED UP TIMING OF STORMS IMPACTING TERMINALS A COUPLE OF
HOURS FROM PREVIOUS TAFS BASED MAINLY ON HRRR WITH TEMPO TSRA WITH
GUSTY WINDS AND FLYING CONDITIONS LOWERING TO AT LEAST MVFR
EXPECTED AT SBN 15-19Z AND 17-21Z AT FWA. SCT SHOWERS SHOULD
PERSIST ALONG AND FOR AWHILE BEHIND THE FRONT TONIGHT WITH LOW VFR
AND PSBLY MVFR CONDITIONS.

SHORT TERM...
TODAY THROUGH FRIDAY NIGHT....THE SEVERE WEATHER POTENTIAL FOR TODAY
AND THIS EVENING IS THE MOST SIGNIFICANT CONCERN FOR THIS PERIOD. A
CONVECTIVE STORM COMPLEX ORGANIZING IN IOWA WAS BEING HELPED BY THE
UPPER LEVEL TROF AND A JET STREAK. THIS COMPLEX SHOULD MOVE ABOUT
DUE EAST AND SHOULD REACH THE FAR NORTHWEST PART OF THE FORECAST
AREA AROUND NOON EDT/16Z. A CAVEAT IS THAT OTHER CONVECTION WAS
ALREADY DEVELOPING AHEAD OF THIS COMPLEX AND COULD CAUSE SOME ISSUES
WITH BOUNDARIES...CLOUDS AND RAIN COOLED AIR. HOWEVER...SIGNIFICANT
UPPER LEVEL SUPPORT AND REASONABLE LOW LEVEL BULK SHEAR COMBINED
WITH INCREASING INSTABILITY WITH DAYTIME HEATING SHOULD BE
SUFFICIENT FOR SEVERE STORMS AS THE COMPLEX MOVES EAST. ATTEMPTED TO
PLACE SOME DETAIL IN THE GRIDS/FORECAST IN REGARD TO THE TIMING AND
COVERAGE OF STORMS. GUT FEELING IS SEVERE STORMS SHOULD BE OVER BY 8
PM EDT. OTHERWISE...MUCH COOLER AIR WILL SPREAD BACK INTO THE AREA.
WENT WITH THE WARMER MET GUIDANCE FOR HIGHS TODAY. THERE SHOULD BE A
SHALLOW RADIATION INVERSION FORM FRIDAY NIGHT...ALLOWING
TEMPERATURES TO FALL INTO THE UPPER 40S TO AROUND 50 DEGREES MOST
AREAS. HAVE LOWERED LOWS SEVERAL DEGREES IN THIS REGARD.

LONG TERM.../SAT-WED/
DEEP VERTICALLY STACKED LOW OVER JAMES BAY AT START OF THE
PERIOD IS EXPECTED TO SLOWLY LIFT NE AND FILL/WEAKEN OVER THE
WEEKEND. WK SHRTWV ROTATING AROUND THE LOW EXPECTED TO MOVE ACROSS
THE WRN GRTLKS SAT NGT/SUNDAY. DRY AIRMASS WILL BE IN PLACE OVER OUR
AREA... BUT THERE MAY BE SUFFICIENT MOISTURE/INSTABILITY FOR
ISOLATED SHOWERS OVER/NEAR LM SAT NGT AND WITH AID OF DIURNAL
HEATING... ACROSS NRN 1/2 OF CWA SUNDAY. COOL POOL ASSOCIATED WITH
THE UPR TROF WILL RESULT IN CONTD BLO NORMAL TEMPS OVER THE WEEKEND
WITH HIGHS IN THE L-M70S AND LOWS IN THE L-M50S. FAIR WX WITH A SLOW
WARMING TREND EXPECTED MON-TUE AS HEIGHTS RISE IN RESPONSE TO WKNG
ERN CANADA/GRTLKS UPR TROF. SHRTWV MOVG INTO PAC NW BY WED WILL
CAUSE WRN U.S. RIDGE TO MOVE EAST INTO THE PLAINS CONTG DRY SPELL
AND GRADUAL WARMING TREND IN OUR AREA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...RIP CURRENT RISK THROUGH FRIDAY EVENING FOR INZ003.

MI...RIP CURRENT RISK THROUGH FRIDAY EVENING FOR MIZ077.

OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR LMZ043-046.

&&

$$

SHORT TERM...SKIPPER
LONG TERM...JT
AVIATION...LEWIS






AREA FORECAST DISCUSSION

NWS GOODLAND KS

 356 PM MDT THU AUG 16 2012

.UPDATE...
ISSUED AT 356 PM MDT THU AUG 16 2012

JUST COMPLETED MINOR UPDATE TO CAPTURE LATEST TREND REGARDING
POPS/SKY OVER WESTERN PARTS OF CWA. ACTIVITY OVER FRONT RANGE
CURRENTLY PROGRESSING EASTWARD TOWARDS WESTERN EXTENT OF CWA.
BASED ON LATEST RUC INSTABILITY REMAINS VERY WEAK OVER OUR CWA
AND THERE IS LITTLE IN THE WAY OF LARGE SCALE ASCENT. JUST BASED
ON CURRENT RADAR TRENDS AND RUC QPF I COULDNT RULE OUT AN ISOLATED
SHOWER OR THUNDERSTORM SNEAKING INTO WESTERN YUMA AND KIT CARSON
COUNTIES LATE THIS AFTERNOON OR EARLY THIS EVENING BEFORE DIURNAL
HEATING COMES TO AN END AND LOW LEVEL LAPSE RATES DECREASE. NO
OTHER SIGNIFICANT CHANGE MADE.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 210 PM MDT THU AUG 16 2012

18Z WATER VAPOR IMAGERY INDICATED AN UPPER LEVEL SHORT WAVE TROUGH
OVER THE NORTH CENTRAL CONUS...WITH THE TROUGH AXIS EXTENDING
SOUTHWEST INTO WESTERN KANSAS.  AT THE SURFACE HIGH PRESSURE WAS
OVER THE NEBRASKA PANHANDLE...BUILDING SOUTHEAST.  THE COLD FRONT WAS
BACKED UP AGAINST THE ROCKIES AND EXTENDED SOUTHEAST INTO THE TEXAS
PANHANDLE.

TONIGHT WINDS WILL BE LIGHT AS THE HIGH PRESSURE BUILDS INTO THE
AREA.  DURING THE OVERNIGHT HOURS THE SURFACE HIGH MOVES EAST OF THE
AREA.  MEANWHILE WARM AIR ADVECTION IN THE 750-650 MB LAYER AND
MOISTURE INCREASE OVER THE EASTERN PART OF THE AREA BEHIND THE
SURFACE HIGH.  A DRY LAYER WILL REMAIN IN PLACE BELOW 750MB SO WILL
KEEP THE PRECIPITATION CHANCES IN THE SLIGHT CATEGORY.

EARLY FRIDAY MORNING WARM AIR ADVECTION INCREASES AND AN UPPER LEVEL
SHORT WAVE TROUGH MOVES OVER THE EASTERN HALF OF THE AREA.
INCREASED PRECIP. CHANCES DURING THE FIRST HALF OF THE MORNING WHEN
THE LIFT AND MOISTURE WILL BE GREATEST.  DURING THE LATE MORNING AND
AFTERNOON THE BETTER ISENTROPIC LIFT/MOISTURE MOVE EAST WITH THE
SHORT WAVE TROUGH...BRINGING PRECIPITATION CHANCES TO AN END FROM WEST
TO EAST.  DURING THE LATE AFTERNOON SURFACE CONVERGENCE/LIFT FROM A
700MB SHORT WAVE TROUGH DEVELOP OVER LINCOLN COUNTY CO.  POINT
SOUNDINGS SHOW THE AIR MASS EITHER BEING TOO DRY OR CAPPED.  HOWEVER
AS THE SURFACE HIGH MOVES EAST IT WILL DRAG THE FRONT ACROSS THE
WEST HALF OF AREA WITH IT.  WILL INCLUDE LOW SLIGHT CHANCES OVER THE
FAR WEST DURING THE LATE AFTERNOON DUE TO THE SHORT WAVE AND FRONT.

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 210 PM MDT THU AUG 16 2012

NORTHWEST FLOW WILL CONTINUE THROUGH SUNDAY WITH A RIDGE OVER THE
ROCKIES AND AN UPPER LOW NORTH OF THE GREAT LAKES. SURFACE HIGH
PRESSURE WILL RESIDE OVER THE CENTRAL PLAINS THROUGH THIS TIME.

A SHORTWAVE COMES THROUGH THE FLOW FRIDAY NIGHT/EARLY SATURDAY. THE
BEST FORCING COMES ACROSS THE FA FRIDAY NIGHT WITH DYNAMICS EXITING
ALL BUT THE EASTERN FA SATURDAY MORNING. SUBSIDENCE MOVES INTO THE
FA SATURDAY AFTERNOON/NIGHT. SUBSIDENCE CONTINUES SUNDAY. 850-700
LAYER MEAN RH IS LIMITED WITH THE BEST MOISTURE JUST TO THE EAST OF
THE FA. DUE TO THE LIMITED MOISTURE WILL GO WITH SLIGHT CHANCE POPS
FRIDAY NIGHT/EARLY SATURDAY WITH NIL POPS SATURDAY AFTERNOON/NIGHT
THROUGH SUNDAY.

MIN TEMPERATURES WILL BE IN THE MID 50S FRIDAY NIGHT AND THE LOWER
TO MID 50S SATURDAY NIGHT. MAX TEMPERATURES WILL RISE TO THE LOWER
80S SATURDAY/SUNDAY.

FOR SUNDAY NIGHT THROUGH THURSDAY...A RIDGE WILL BE OVER THE ROCKIES
THROUGH THURSDAY. OTHER THAN SURFACE HIGH PRESSURE SUNDAY, A TROUGH
WILL EXIST OVER EASTERN COLORADO THROUGH THURSDAY.

SHORTWAVES IN THE FLOW WILL BRING A SLIGHT CHANCE OF THUNDERSTORMS
MONDAY THROUGH TUESDAY NIGHT. DYNAMICS MOVE OFF TO THE NORTHEAST
WEDNESDAY WITH SUBSIDENCE FOLLOWING WEDNESDAY NIGHT/THURSDAY.

850 TEMPERATURES INDICATE STEADILY WARMER TEMPERATURES WITH MAX
TEMPERATURES IN THE MID 80S MONDAY WARMING TO THE LOWER 90S
WEDNESDAY COOLING SLIGHTLY TO THE UPPER 80S THURSDAY. MIN
TEMPERATURES WILL RANGE FROM THE LOWER 60S TO THE MID 60S.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1107 AM MDT THU AUG 16 2012

VFR CONDITIONS FORECAST FOR THE 18Z TAFS. SURFACE HIGH PRESSURE
OVER WESTERN NEBRASKA WILL CONTINUE TO BUILD SOUTHEAST TODAY
THROUGH FRIDAY. SPOTTY SPRINKLES MAY STILL DEVELOP NEAR/OVER KMCK
THROUGH THE EARLY AFTERNOON AHEAD OF THE SURFACE HIGH...BUT AM NOT
ANTICIPATING ANY RESTRICTIONS WITH THEM. OTHERWISE PRECIPITATION
CHANCES WILL INCREASE OVERNIGHT THROUGH FRIDAY MORNING...MAINLY
EAST OF KGLD. AM ANTICIPATING MOSTLY RAIN SHOWERS WITH ISOLATED
THUNDERSTORMS...MAINLY DURING THE MORNING. DECIDED AGAINST ADDING
A MENTION OF VCSH TO KMCK AT THIS TIME SINCE THERE IS TOO MUCH
UNCERTAINTY WITH SHOWERS DEVELOPING NEAR/OVER KMCK AT THIS TIME.
WINDS WILL INCREASE FOR KGLD DURING THE MORNING AS THE SURFACE
HIGH PRESSURE MOVES EAST AND THE PRESSURE GRADIENT TIGHTENS BEHIND
IT. ANTICIPATE THE WINDS TO DECLINE DURING THE AFTERNOON.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...DR
SHORT TERM...FS
LONG TERM...JTL
AVIATION...JTL







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 1217 PM CDT THU AUG 16 2012

.UPDATE...
ISSUED AT 1215 PM CDT THU AUG 16 2012

QUICK UPDATE TO THE GRIDS TO ACCOUNT FOR LATEST KDDC WSR-88D
TRENDS. SCATTERED SPRINKLES WILL BE LIKELY THIS AFTERNOON ACROSS
THE NORTHWESTERN AND NORTHERN ZONES. THE HRRR HAS LATCHED ON ACTIVITY
APPROPRIATELY.

&&

.SYNOPSIS...
ISSUED AT 911 AM CDT THU AUG 16 2012

THE 16.12Z 250 HPA SYNOPTIC MAP SHOWED AN 80-85 KT JET STREAK MOVING
ACROSS SOUTH DAKOTA AND INTO MINNESOTA. ANOTHER 80-85 KT JET STREAK
WAS LOCATED ACROSS NEW ENGLAND. AT 500 HPA, A SHORTWAVE TROF WAS LOCATED
FROM ONTARIO SOUTHWARD TO NEBRASKA. MID LEVEL COLD AIR ADVECTION WAS
OCCURRING IN THE WAKE OF THE TROF ACROSS THE NORTHERN PLAINS. ANOTHER
ELONGATED SHORTWAVE TROF WAS LOCATED ACROSS THE NORTHEAST US. AT 700
HPA, LOW TO MID LEVEL TEMPERATURES WERE STILL WARM ACROSS SW KANSAS
WITH KDDC MEASURING 13 DEG C. THIS WAS PROBABLY THE REASON FOR A LACK
OF CONVECTION ALONG A FRONT THAT MOVED THROUGH. ALL THE COLD AIR WITH
700 HPA TEMPERATURES BELOW 5 DEG C WAS LOCATED ACROSS THE DAKOTAS AND
NORTHWARD. AT 850 HPA, A BAROCLINIC ZONE WAS BISECTING KANSAS SEPARATING
20S DEG C AIR FROM LOWER TEENS DEG C. VALUES AS LOW AS 6 DEG C WERE
OBSERVED ACROSS THE DAKOTAS AND MONTANA. KDDC WAS MUCH COOLER THAN 12
HOURS AGO (18 DEG C VERSUS 27 DEG C). AT THE SURFACE, A 995 HPA CYCLONE
WAS LOCATED ACROSS WESTERN ONTARIO WITH A COLD FRONT FROM THIS SYSTEM
SOUTHWEST TO THE TEXAS PANHANDLE. A 1025 HPA HIGH LOCATED ACROSS THE
LEE OF THE NORTHERN ROCKIES WAS MOVING SOUTHWARD IN THE WAKE OF THE
SURFACE FRONT.

&&

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 355 AM CDT THU AUG 16 2012

A STRONG SHORTWAVE TROUGH MOVING ACROSS THE NORTHERN PLAINS EARLY
THIS MORNING WILL PUSH A COLD FRONT INTO OKLAHOMA BY THIS AFTERNOON.
WITH THE LOSS OF DAYTIME HEATING, SURFACE BASED THUNDERSTORMS HAD
DISSIPATED ACROSS NORTHERN KANSAS EARLIER TONIGHT. MODEL SOUNDINGS
FOR SOUTH CENTRAL KANSAS FOR EARLY THIS MORNING SHOW STRONG CAPPING
AHEAD OF THE FRONT. SURFACE BASED CONVECTION SEEMS HIGHLY UNLIKELY,
ESPECIALLY GIVEN THE INITIALLY SHALLOW NATURE OF THE LOW LEVEL FRONT
AS IT ENCOUNTERS THE 60-65F DEWPOINTS AS WELL AS THE TIME OF DAY.
ALSO, WITH THE MAIN UPPER-LEVEL JET STREAK WELL TO THE NORTH AND
ANOTHER MINOR JET STREAK WELL TO OUR SOUTH, DEEP, LARGE SCALE LIFT
IS ABSENT. SO WE ARE EXPECTING A DRY FRONTAL PASSAGE, WITH ONLY
SCATTERED TO BROKEN MID TO HIGH LEVEL CLOUDS. WINDS WILL BE FROM THE
NORTH TO NORTHEAST AT 20-25 KTS FROM 15-18Z BEFORE DIMINISHING TO 15
KTS LATER THIS AFTERNOON AS THE PRESSURE GRADIENT RELAXES. I DECIDED
TO UNDERCUT THE NAM TEMPERATURES FOR TODAY JUST SLIGHTLY SINCE THE
FRONT IS AHEAD OF SCHEDULE WITH STRONG COLD ADVECTION IN ITS WAKE.
IF POST FRONTAL CLOUD COVER IS MORE EXTENSIVE THAN FORE CAST THEN
IT COULD STAY EVEN COOLER. BUT I SEE NO REASON WHY MID-LEVEL CLOUD
WOULD STAY ABUNDANT ALL DAY.

BY LATE TONIGHT, THE AFOREMENTIONED SHORTWAVE TROUGH WILL HAVE
PASSED INTO THE GREAT LAKES REGION, WITH WESTERN KANSAS IN THE RIGHT
ENTRANCE REGION OF THE ASSOCIATED JET STREAK, ALONG WITH SOME MID
LEVEL FRONTOGENESIS. A FEW SHOWERS AND THUNDERSTORMS MAY DEVELOP
TOWARD MORNING, WITH THE BEST CHANCES IN CENTRAL KANSAS. ALTHOUGH
TEMPERATURES SHOULD BE RATHER COOL, CLOUD COVER AND 5 TO 7 KT WINDS
COULD PREVENT TEMPERATURES FROM REALLY BOTTOMING OUT. HOWEVER, IF
THE CLEAR BREAKS ARE SIGNIFICANT, THEN TEMPERATURES COULD FALL INTO
THE LOWER OR MIDDLE 50S. MINIMUM TEMPERATURES COULD ACTUALLY BE LOWER IN
PLACES LIKE ULYSSES AND ELKHART THAN HAYS SINCE CLOUD COVER MAY BE
MORE ABUNDANT IN CENTRAL KANSAS THAN THE FAR SOUTHWEST.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 355 AM CDT THU AUG 16 2012

N UPPER LEVEL TROUGH WILL MOVE EAST ACROSS THE GREAT LAKES REGION
ON FRIDAY AS AN AREA OF HIGH PRESSURE AT THE SURFACE SETTLES INTO
THE CENTRAL PLAINS. BASED ON THE COOLING FORECAST IN THE 925-850MB
LEVEL BY FRIDAY AFTERNOON THE PREVIOUS FORECAST STILL LOOKS ON
TRACK. DID HOWEVER LOWER TEMPERATURES BACK INTO THE UPPER 70S IN
NORTH CENTRAL AND IN PARTS OF WEST CENTRAL KANSAS GIVEN THE LATEST
NAM AND ECMWF 850MB TEMPERATURES AND PROBABILITY OF INCREASING CLOUD
COVER.

CLOUD COVER IS EXPECTED TO INCREASE ACROSS SOUTHWEST KANSAS ON
FRIDAY AS 850-700MB WINDS VEER AND WARM AIR ADVECTION DEVELOPS.
I310-I315 ISENTROPIC LIFT ALSO WILL BE IMPROVING LATE FRIDAY AND
WILL THEN CONTINUE ACROSS WESTERN KANSAS THROUGH SATURDAY. IN
ADDITION AN UPPER LEVEL TROUGH IS FORECAST TO CROSS THE CENTRAL
PLAINS EARLY THIS WEEKEND AS AN UPPER LEVEL JET CROSSES THE PLAINS.
GIVEN THIS ALONG WITH THE LOCATION OF THE RIGHT ENTRANCE REGION OF
THE UPPER LEVEL JET WILL FAVOR KEEPING THE BETTER CHANCES FOR
PRECIPITATION EARLY SATURDAY. THE PRECIPITATION CHANCES WILL THEN
BEGIN TO TAPER OFF EARLY SATURDAY NIGHT FROM NORTH TO SOUTH AS THIS
UPPER WAVE/JET PASSES.

SUNDAY STILL APPEARS TO BE DRY WHILE ANOTHER UPPER LEVEL TROUGH IS
FORECAST BY BOTH THE ECMWF AND GFS TO MOVE OUT OF THE ROCKIES AND
ACROSS THE CENTRAL PLAINS LATE MONDAY/EARLY TUESDAY. AS FOR
TEMPERATURES SUNDAY AND MONDAY A SLOW WARMING TREND IS EXPECTED BUT
HIGHS STILL APPEAR TO BE MAINLY IN THE 80S GIVEN 850MB TEMPERATURES
AT 00Z MONDAY AND 00Z TUESDAY GENERALLY RANGING FROM 20C TO 23C.

A TROUGH OF LOW PRESSURE AT THE SURFACE WILL DEVELOP ALONG THE LEE
OF THE ROCKIES EARLY NEXT WEEK AS WARMER 850-700MB TEMPERATURES
BEGIN TO SPREAD EAST ACROSS EASTERN COLORADO/WESTERN KANSAS. THE GFS
ATTEMPTS TO DEVELOP SOME OVERNIGHT CONVECTION MID WEEK ACROSS
PORTIONS OF WESTERN AND SOUTH CENTRAL KANSAS JUST EAST OF THE WARM
(+10 TO +12C) 700MB TEMPERATURES WHERE SOME 850MB WARM AIR ADVECTION
DEVELOPS. UPPER LEVEL DYNAMICS APPEAR SOMEWHAT LACKING TOWARDS MID
WEEK AS DOES THE 850-700MB MOISTURE BUT AT THIS TIME CONFIDENCE IS
NOT HIGH ENOUGH YET TO REMOVE MENTION OF PRECIPITATION MID WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1200 PM CDT THU AUG 16 2012

VFR CIGS EXPECTED THROUGH PD. NORTHEASTERLY WINDS AROUND 20 KT
WILL DECREASE 10 TO 15 KT BY THIS EVENING AND CONTINUE TO VEER
THROUGH THE OVERNIGHT. THETA-E ADVECTION/WARM AIR ADVECTION/ISENTROPIC
LIFT WILL LEAD TO CONVECTION ACROSS CENTRAL KANSAS TOMORROW
MORNING. HAVE INSERTED CB/TS GROUPS AS A RESULT FOR KHYS.


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  84  56  80  59 /  10  20  20  30
GCK  82  55  80  58 /  10  10  20  20
EHA  84  57  83  61 /  10  10  20  20
LBL  86  57  83  60 /  10  10  20  30
HYS  81  57  79  59 /  10  20  20  30
P28  87  59  82  62 /  10  20  20  30

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

UPDATE...SUGDEN
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...SUGDEN







AREA FORECAST DISCUSSION

NWS TOPEKA KS

 241 AM CDT THU AUG 16 2012

.DISCUSSION...

UPPER TROF SLIDING ACROSS THE UPPER MIDWEST AND GENERATING ROUND
OF SHOWERS AND THUNDERSTORMS TO OUR NORTH AND EAST. SOUTHERN END
OF THE SURFACE FRONT SLIDING ACROSS THE CWA ATTM BRINGING GUSTY
WINDS AS IT PASSES. SHOWER ACTIVITY ALSO NOTED DEVELOPING OVER
WESTERN KS AND CENTRAL NEBRASKA ATTM WHILE THE REMAINDER OF
CENTRAL AND EASTERN KANSAS REMAINS DRY.

FOR TODAY...THINK TOO MUCH DRY AIR IN THE LAYER COUPLED WITH THE
LAG OF BETTER LIFT BACK SO FAR NW OF THE SURFACE FRONT HAS LEFT
THE INITIAL FRONTAL PUSH DRY FOR OUR AREA. ISENTROPIC CHARTS WOULD
SUGGEST POTENTIAL FOR SOME SHOWERS LATER THIS MORNING AND WILL
LEAVE JUST ISOLATED CHANCES AT THIS TIME. IF FRONT STALLS ACROSS
THE SOUTHEAST COUNTIES LATE THIS MORNING WOULD ANTICIPATE SOME
REDEVELOPMENT OF STORMS ALONG THE FRONT WHERE AFTERNOON MOISTURE
AND INSTABILITY POOL...BUT WILL DEPEND ON HOW FAR SOUTH THE FRONT
MAKES IT BEFORE LATE AFTERNOON. FOR NOW WILL CARRY POPS FROM
TOPEKA SOUTHEAST WITH BETTER CHANCES THE FARTHER SOUTHEAST YOU GO.
HIGHS SHOULD BE ON THE COOL SIDE WITH THE FRONT ALMOST TO MHK AT
THIS HOUR...WITH 70S NORTHWEST AND LOWER 80S SOUTHEAST. LOWS
TONIGHT RANGE FROM LOWER 50S NW TO UPPER 50S SE.

FRI/SAT/SUN...AIRMASS REMAINS ON THE COOL SIDE OF NORMAL THROUGH
THE WEEKEND WITH HIGHS IN THE LOWER 80S FOR MUCH OF THE AREA. EC
SUGGESTS LATE DAY CONVECTION ON THE HIGH PLAINS FRIDAY STAYS WEST
OF THE AREA. LEFT SOME SLIGHT CHANCES WEST THEN SOUTHWEST FOR
SATURDAY AND SATURDAY NIGHT AS ANOTHER POTENTIAL SHORTWAVE MOVES
THROUGH THE FLOW.

TEMPERATURES SLOWLY RISE MONDAY INTO TUESDAY AS SOUTHERLY FLOW
AROUND THE SURFACE HIGH RETURNS TO THE PLAINS..WITH MIDDLE 80S
MONDAY AND A FEW DEGREES WARMER TUESDAY. AGAIN LEFT SOME SLIGHT
CHANCE POPS WEST ON TUESDAY WITH NEXT SHORTWAVE. 67

&&

.AVIATION...
HIRES HRRR/NMM CONTINUE TO SHOW ISOLATED TO WIDELY SCATTERED
CONVECTION ALONG OR JUST AHEAD OF THE FRONT. THIS SEEMS TO BE
SUPPORTED BY RADAR TRENDS OVER THE LAST FEW HOURS. SO CONFIDENCE IN
CONVECTION ACTUALLY AFFECTING A GIVEN TERMINAL IS MARGINAL AT THIS
POINT AND WILL MAINTAIN A VCTS. THE GFS IS HINTING AT SOME MVFR CIGS
MOVING IN BEHIND THE FRONT. THE RAP AND NAM SHOW LOWER HUMIDITIES AT
925MB SUGGESTING A BKN DECK IS LESS LIKELY. WILL MENTION A SCT MVFR
DECK WITH THE FROPA...BUT THE MID SHIFT MAY NEED TO WATCH THIS AND
INCLUDE A TEMPO FOR MVFR CIGS IF IT LOOKS LIKE LOW CLOUDS ARE
DEVELOPING AS THE GFS SHOWS.

WOLTERS


&&

.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS TOPEKA KS

 1128 PM CDT WED AUG 15 2012

.DISCUSSION...
SEE PREV DISCUSSION.

&&

.AVIATION...
HIRES HRRR/NMM CONTINUE TO SHOW ISOLATED TO WIDELY SCATTERED
CONVECTION ALONG OR JUST AHEAD OF THE FRONT. THIS SEEMS TO BE
SUPPORTED BY RADAR TRENDS OVER THE LAST FEW HOURS. SO CONFIDENCE IN
CONVECTION ACTUALLY AFFECTING A GIVEN TERMINAL IS MARGINAL AT THIS
POINT AND WILL MAINTAIN A VCTS. THE GFS IS HINTING AT SOME MVFR CIGS
MOVING IN BEHIND THE FRONT. THE RAP AND NAM SHOW LOWER HUMIDITIES AT
925MB SUGGESTING A BKN DECK IS LESS LIKELY. WILL MENTION A SCT MVFR
DECK WITH THE FROPA...BUT THE MID SHIFT MAY NEED TO WATCH THIS AND
INCLUDE A TEMPO FOR MVFR CIGS IF IT LOOKS LIKE LOW CLOUDS ARE
DEVELOPING AS THE GFS SHOWS.

WOLTERS

&&

.PREV DISCUSSION.../ISSUED 343 PM CDT WED AUG 15 2012/
TONIGHT AND THURSDAY...FCST FOCUS REMAINS ON COLD FRONT AND
ASSOCIATED RAIN CHCS.

FAVOR THE NAM OVER THE GFS FOR THE SHORT TERM FCST GIVEN RECENT
VERIFICATION AND BIAS. EXPECT THE COLD FRONT TO SWEEP THROUGH THE
AREA IN THE 10Z TO 14Z TIME FRAME ON THU. STRONGER DYNAMICS WILL
LEAD TO MORE WIDESPREAD PRECIP TO THE NORTH OF THE AREA WHILE
FRONTAL FORCING SHOULD YIELD SOME SCT CONVECTION ACROSS THE CWA
MAINLY AFTER 06Z. TIMING OF FRONT DOES NOT SUGGEST MORE THAN 20 TO
30 PERCENT COVERAGE AND WILL KEEP RAIN CHCS LOWER THAN THE MAV/GFS
GUIDANCE.

BREEZY NORTH WINDS BEHIND THE FRONT SHOULD ARRIVE BY MORNING WITH
MAX TEMPS EXPECTED TO RISE CLOSER TO THE WARMER NAM GUIDANCE GIVEN
TIME OF YEAR AND EXPECTED CLOUD HTS. RAIN CHCS AFTER 12Z APPEAR SLIM
AND WILL CONTINUE TO UNDERCUT GFS GUIDANCE.

OMITT

FRIDAY THROUGH TUESDAY...CONTINUED NW FLOW PATTERN PERSISTS
THROUGH THE EXTENDED WITH TWO SHORTWAVE TROFS AFFECTING
NORTHEASTERN KANSAS THROUGH TUESDAY. BIGGEST FACTOR IN BOTH EVENTS
WILL BE THE ABILITY OF MOISTURE TO RETURN IN TIME TO BE AVAILABLE
FOR THE WEAK FRONTAL PASSAGES.

THE FIRST SYSTEM ROTATES  AROUND A DEEP LOW PRESSURE SYSTEM ANCHORED
NEAR HUDSON BAY ON SATURDAY. A RELATIVELY NARROW BAND OF MOISTER
AND WEAK CONVERGENCE WILL REALLY LIMIT THE POTENTIAL OF THIS WAVE TO
PRODUCE WIDESPREAD PRECIPITATION. STILL...GIVEN IT MAY PASS DURING
THE AFTERNOON WITH SOME INSTABILITY TO TAP...LOWER CHANCES OF PRECIP
SEEM REASONABLE.

THE SECOND WAVE AGAIN MOVES IN FROM THE NORTHWEST OVERNIGHT MONDAY
INTO TUESDAY MORNING. THIS SYSTEM HAS A DECENT FETCH OF MOISTURE
INFLUX FROM THE SOUTH AS THE WAVE PASSES. LIMITING FACTOR WITH THIS
SYSTEM IS A LACK OF DECENT CONVERGENCE TO FOCUS PRECIPITATION.
HOWEVER...AN OVERNIGHT EVENT WITH A STRENGTHENING LOW LEVEL JET
AIDING ELEVATED THUNDERSTORMS LOOKS TO BE THE MOST LIKELY SCENARIO
AND HAVE KEPT PREVIOUS TREND OF PRECIPITATION CHANCES.

NO WILD SWINGS IN TEMPERATURE WITH ANY OF THE SYSTEM PASSAGES...BUT
EXPECT SLIGHTLY BELOW TEMPS FRIDAY THROUGH SUNDAY...AND NEAR NORMAL
MONDAY AND TUESDAY.

HARDING

&&

.TOP WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS GRAY ME

 1006 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS NORTHERN NEW ENGLAND
TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH IT. THE
FRONT WILL STALL OVER THE GULF OF MAINE AS LOW PRESSURE MOVES
ALONG IT SATURDAY INTO SUNDAY. AT THE PRESENT TIME IT LOOKS LIKE
MOST OF THE CLOUDS AND RAIN WITH THIS SYSTEM WILL STAY JUST EAST
OF THE REGION.

&&

.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
LATEST UPDATE IS TO USE THE "EXTRAPOLATE" TOOL WITH THE LINES OF
CONVECTION.

CONVECTION CONTS TO MARCH EASTWARD...MUCH IN LINE WITH THE
SAME OVERALL PATTERN SHOWN IN THE LATEST HRRR MODEL. HAVE INCLUDED
THE POSSIBILITY OF GUSTY WINDS AND HAIL TO THE GRIDS AS WELL AS
SOME OF THE STMS ARE NOW SHOWING CORES WELL ABV THE FRZG LVL. HAVE
ALSO INCREASED POPS IN A LINE MOVG EASTWARD INTO CTNRL ME OVER THE
NEXT FEW HRS.

MADE A FEW ADJUSTMENTS TO CLOUD COVER AND DEW POINTS AS WELL.
OTRW...FCST WILL REMAIN RELATIVELY UNCHANGED. UPDATE FOR NEW
CONVECTION RACING ACROSS SRN/CNTRL NH AS WELL.

PREV DISC...
MOSTLY SUNNY SKIES ACROSS THE REGION THIS AFTERNOON WITH DEW
POINTS MAINLY IN THE 50S TO LOWER 60S. A WEAK FRONTAL BOUNDARY IS
APPROACHING THE CWA FROM THE WEST. INSTABILITY AHEAD OF THE FRONT
IS AT BEST WEAK. APPEARS AS THOUGH THE NAM HAS A LITTLE BETTER
HANDLE ON THIS FEATURE THAN THE GFS DOES. ONLY ISOLATED SHOWERS
POPPING UP OVER THE ADIRONDACKS TO THE WEST OF US WHERE
INSTABILITY IS BETTER. BECAUSE OF THIS...WILL BACK OFF OF POPS A
BIT THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE MOUNTAINS.
BOUNDARY LOOKS AS THOUGH IT WILL WASH OUT QUITE A BIT AS IT MOVES
ACROSS THE AREA.

&&

.SHORT TERM /SATURDAY NIGHT/...
THE FRONTAL BOUNDARY WILL STALL JUST OFFSHORE EARLY SATURDAY. THIS
LOOKS LIKE IT WILL BE THE TRICKIEST PART OF THE FORECAST. THE NAM
TAKES THE BOUNDARY INTO THE GULF OF MAINE SATURDAY MORNING. IT
DEVELOPS A WAVE THAT MOVES ALONG THE BOUNDARY AND PRODUCES SOME
PRECIPITATION JUST OFFSHORE. THE GFS ON THE OTHER HAND...KEEPS THE
BOUNDARY ALONG THE COAST AND GENERATES PRECIPITATION TOMORROW
MORNING ALONG THE COAST OF MAINE. AGAIN...FEEL AS THOUGH THE NAM
IS HANDLING THIS FEATURE BETTER DUE TO INITIALIZATION OF
CONVECTION OVER NEW YORK STATE TODAY. ONCE THE BOUNDARY IS CLEAR
OF THE COAST...HIGH PRESSURE WILL BUILD IN FOR TOMORROW NIGHT.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEM WITH DEPARTING LOW WILL KEEP CLOUDS AND SHOWER
THREAT OVER THE COASTAL WATERS ON SUNDAY. EXPECT LAND AREAS TO
REMAIN DRY. CLOUDS ALONG THE IMMEDIATE COAST COULD BE PROBLEMATIC
DEPENDING ON HOW QUICKLY THE FRONT PUSHES EAST. HAVE GONE WITH A
EURO-GFS SOLUTION AS THE NAM IS SLOWER IN MOVING THE FRONT EAST.
WEAK RIDGING WILL KEEP THINGS DRY SUNDAY NIGHT INTO MONDAY. A WEAK
TROUGH WILL CROSS THE AREA LATE MONDAY INTO MONDAY NIGHT. THIS
MAY BRING A FEW SHOWERS WITH IT.

TUE-FRI THE AREA WILL BE UNDER A CYCLONIC FLOW ALOFT. WHILE NO
LARGE SCALE PRECIPITATION EVENT IS FORECAST...A FEW SHOWERS ARE
POSSIBLE ESPECIALLY DIURNALLY OVER THE MOUNTAINS. IN ADDITION ANY SHORT
WAVES MOVING THROUGH THIS CYCLONIC FLOW COULD TRIGGER SHOWERS.
TIMING OF THESE SUBTLE FEATURES IN THE LONG RANGE PORTION OF THE
FORECAST IS DIFFICULT. TEMPERATURES SHOULD BE NEAR NORMAL.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL PREVAIL INTO THE EVENING HOURS.
AN APPROACHING BOUNDARY MAY GENERATE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS EVENING. EXPECT RADIATION FOG TO SET UP AGAIN
TONIGHT AND DROP VSBY AND CIGS TO IFR/LIFR BY MORNING. FOG SHOULD
NOT BE AS THICK AS LAST NIGHT AND IS EXPECTED TO BURN OFF QUICKER.

LONG TERM...MAINLY MVFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...NO FLAGS EXPECTED.

LONG TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$






AREA FORECAST DISCUSSION

NWS GRAY ME

 752 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS NORTHERN NEW ENGLAND
TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH IT. THE
FRONT WILL STALL OVER THE GULF OF MAINE AS LOW PRESSURE MOVES
ALONG IT SATURDAY INTO SUNDAY. AT THE PRESENT TIME IT LOOKS LIKE
MOST OF THE CLOUDS AND RAIN WITH THIS SYSTEM WILL STAY JUST EAST
OF THE REGION.

&&

.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
LATEST UPDATE IS TO USE THE "EXTRAPOLATE" TOOL WITH THE LINES OF
CONVECTION.

CONVECTION CONTS TO MARCH EASTWARD...MUCH IN LINE WITH THE
SAME OVERALL PATTERN SHOWN IN THE LATEST HRRR MODEL. HAVE INCLUDED
THE POSSIBILITY OF GUSTY WINDS AND HAIL TO THE GRIDS AS WELL AS
SOME OF THE STMS ARE NOW SHOWING CORES WELL ABV THE FRZG LVL. HAVE
ALSO INCREASED POPS IN A LINE MOVG EASTWARD INTO CTNRL ME OVER THE
NEXT FEW HRS.

MADE A FEW ADJUSTMENTS TO CLOUD COVER AND DEW POINTS AS WELL.
OTRW...FCST WILL REMAIN RELATIVELY UNCHANGED. UPDATE FOR NEW
CONVECTION RACING ACROSS SRN/CNTRL NH AS WELL.

PREV DISC...
MOSTLY SUNNY SKIES ACROSS THE REGION THIS AFTERNOON WITH DEW
POINTS MAINLY IN THE 50S TO LOWER 60S. A WEAK FRONTAL BOUNDARY IS
APPROACHING THE CWA FROM THE WEST. INSTABILITY AHEAD OF THE FRONT
IS AT BEST WEAK. APPEARS AS THOUGH THE NAM HAS A LITTLE BETTER
HANDLE ON THIS FEATURE THAN THE GFS DOES. ONLY ISOLATED SHOWERS
POPPING UP OVER THE ADIRONDACKS TO THE WEST OF US WHERE
INSTABILITY IS BETTER. BECAUSE OF THIS...WILL BACK OFF OF POPS A
BIT THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE MOUNTAINS.
BOUNDARY LOOKS AS THOUGH IT WILL WASH OUT QUITE A BIT AS IT MOVES
ACROSS THE AREA.

&&

.SHORT TERM /SATURDAY NIGHT/...
THE FRONTAL BOUNDARY WILL STALL JUST OFFSHORE EARLY SATURDAY. THIS
LOOKS LIKE IT WILL BE THE TRICKIEST PART OF THE FORECAST. THE NAM
TAKES THE BOUNDARY INTO THE GULF OF MAINE SATURDAY MORNING. IT
DEVELOPS A WAVE THAT MOVES ALONG THE BOUNDARY AND PRODUCES SOME
PRECIPITATION JUST OFFSHORE. THE GFS ON THE OTHER HAND...KEEPS THE
BOUNDARY ALONG THE COAST AND GENERATES PRECIPITATION TOMORROW
MORNING ALONG THE COAST OF MAINE. AGAIN...FEEL AS THOUGH THE NAM
IS HANDLING THIS FEATURE BETTER DUE TO INITIALIZATION OF
CONVECTION OVER NEW YORK STATE TODAY. ONCE THE BOUNDARY IS CLEAR
OF THE COAST...HIGH PRESSURE WILL BUILD IN FOR TOMORROW NIGHT.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEM WITH DEPARTING LOW WILL KEEP CLOUDS AND SHOWER
THREAT OVER THE COASTAL WATERS ON SUNDAY. EXPECT LAND AREAS TO
REMAIN DRY. CLOUDS ALONG THE IMMEDIATE COAST COULD BE PROBLEMATIC
DEPENDING ON HOW QUICKLY THE FRONT PUSHES EAST. HAVE GONE WITH A
EURO-GFS SOLUTION AS THE NAM IS SLOWER IN MOVING THE FRONT EAST.
WEAK RIDGING WILL KEEP THINGS DRY SUNDAY NIGHT INTO MONDAY. A WEAK
TROUGH WILL CROSS THE AREA LATE MONDAY INTO MONDAY NIGHT. THIS
MAY BRING A FEW SHOWERS WITH IT.

TUE-FRI THE AREA WILL BE UNDER A CYCLONIC FLOW ALOFT. WHILE NO
LARGE SCALE PRECIPITATION EVENT IS FORECAST...A FEW SHOWERS ARE
POSSIBLE ESPECIALLY DIURNALLY OVER THE MOUNTAINS. IN ADDITION ANY SHORT
WAVES MOVING THROUGH THIS CYCLONIC FLOW COULD TRIGGER SHOWERS.
TIMING OF THESE SUBTLE FEATURES IN THE LONG RANGE PORTION OF THE
FORECAST IS DIFFICULT. TEMPERATURES SHOULD BE NEAR NORMAL.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL PREVAIL INTO THE EVENING HOURS.
AN APPROACHING BOUNDARY MAY GENERATE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS EVENING. EXPECT RADIATION FOG TO SET UP AGAIN
TONIGHT AND DROP VSBY AND CIGS TO IFR/LIFR BY MORNING. FOG SHOULD
NOT BE AS THICK AS LAST NIGHT AND IS EXPECTED TO BURN OFF QUICKER.

LONG TERM...MAINLY MVFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...NO FLAGS EXPECTED.

LONG TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$






AREA FORECAST DISCUSSION

NWS GRAY ME

 719 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A WEAK FRONTAL BOUNDARY WILL MOVE ACROSS NORTHERN NEW ENGLAND
TONIGHT BRINGING SCATTERED SHOWERS AND THUNDERSTORMS WITH IT. THE
FRONT WILL STALL OVER THE GULF OF MAINE AS LOW PRESSURE MOVES
ALONG IT SATURDAY INTO SUNDAY. AT THE PRESENT TIME IT LOOKS LIKE
MOST OF THE CLOUDS AND RAIN WITH THIS SYSTEM WILL STAY JUST EAST
OF THE REGION.

&&

.NEAR TERM /THROUGH SATURDAY/...
UPDATE...
CONVECTION CONTS TO MARCH EASTWARD...MUCH IN LINE WITH THE SAME
OVERALL PATTERN SHOWN IN THE LATEST HRRR MODEL. HAVE INCLUDED THE
POSSIBILITY OF GUSTY WINDS AND HAIL TO THE GRIDS AS WELL AS SOME
OF THE STMS ARE NOW SHOWING CORES WELL ABV THE FRZG LVL. HAVE ALSO
INCREASED POPS IN A LINE MOVG EASTWARD INTO CTNRL ME OVER THE NEXT
FEW HRS.

MADE A FEW ADJUSTMENTS TO CLOUD COVER AND DEW POINTS AS WELL.
OTRW...FCST WILL REMAIN RELATIVELY UNCHANGED. UPDATE FOR NEW
CONVECTION RACING ACROSS SRN/CNTRL NH AS WELL.

PREV DISC...
MOSTLY SUNNY SKIES ACROSS THE REGION THIS AFTERNOON WITH DEW
POINTS MAINLY IN THE 50S TO LOWER 60S. A WEAK FRONTAL BOUNDARY IS
APPROACHING THE CWA FROM THE WEST. INSTABILITY AHEAD OF THE FRONT
IS AT BEST WEAK. APPEARS AS THOUGH THE NAM HAS A LITTLE BETTER
HANDLE ON THIS FEATURE THAN THE GFS DOES. ONLY ISOLATED SHOWERS
POPPING UP OVER THE ADIRONDACKS TO THE WEST OF US WHERE
INSTABILITY IS BETTER. BECAUSE OF THIS...WILL BACK OFF OF POPS A
BIT THIS AFTERNOON AND EVENING...ESPECIALLY OVER THE MOUNTAINS.
BOUNDARY LOOKS AS THOUGH IT WILL WASH OUT QUITE A BIT AS IT MOVES
ACROSS THE AREA.

&&

.SHORT TERM /SATURDAY NIGHT/...
THE FRONTAL BOUNDARY WILL STALL JUST OFFSHORE EARLY SATURDAY. THIS
LOOKS LIKE IT WILL BE THE TRICKIEST PART OF THE FORECAST. THE NAM
TAKES THE BOUNDARY INTO THE GULF OF MAINE SATURDAY MORNING. IT
DEVELOPS A WAVE THAT MOVES ALONG THE BOUNDARY AND PRODUCES SOME
PRECIPITATION JUST OFFSHORE. THE GFS ON THE OTHER HAND...KEEPS THE
BOUNDARY ALONG THE COAST AND GENERATES PRECIPITATION TOMORROW
MORNING ALONG THE COAST OF MAINE. AGAIN...FEEL AS THOUGH THE NAM
IS HANDLING THIS FEATURE BETTER DUE TO INITIALIZATION OF
CONVECTION OVER NEW YORK STATE TODAY. ONCE THE BOUNDARY IS CLEAR
OF THE COAST...HIGH PRESSURE WILL BUILD IN FOR TOMORROW NIGHT.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
FRONTAL SYSTEM WITH DEPARTING LOW WILL KEEP CLOUDS AND SHOWER
THREAT OVER THE COASTAL WATERS ON SUNDAY. EXPECT LAND AREAS TO
REMAIN DRY. CLOUDS ALONG THE IMMEDIATE COAST COULD BE PROBLEMATIC
DEPENDING ON HOW QUICKLY THE FRONT PUSHES EAST. HAVE GONE WITH A
EURO-GFS SOLUTION AS THE NAM IS SLOWER IN MOVING THE FRONT EAST.
WEAK RIDGING WILL KEEP THINGS DRY SUNDAY NIGHT INTO MONDAY. A WEAK
TROUGH WILL CROSS THE AREA LATE MONDAY INTO MONDAY NIGHT. THIS
MAY BRING A FEW SHOWERS WITH IT.

TUE-FRI THE AREA WILL BE UNDER A CYCLONIC FLOW ALOFT. WHILE NO
LARGE SCALE PRECIPITATION EVENT IS FORECAST...A FEW SHOWERS ARE
POSSIBLE ESPECIALLY DIURNALLY OVER THE MOUNTAINS. IN ADDITION ANY SHORT
WAVES MOVING THROUGH THIS CYCLONIC FLOW COULD TRIGGER SHOWERS.
TIMING OF THESE SUBTLE FEATURES IN THE LONG RANGE PORTION OF THE
FORECAST IS DIFFICULT. TEMPERATURES SHOULD BE NEAR NORMAL.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
SHORT TERM...VFR CONDITIONS WILL PREVAIL INTO THE EVENING HOURS.
AN APPROACHING BOUNDARY MAY GENERATE SOME SCATTERED SHOWERS AND
THUNDERSTORMS THIS EVENING. EXPECT RADIATION FOG TO SET UP AGAIN
TONIGHT AND DROP VSBY AND CIGS TO IFR/LIFR BY MORNING. FOG SHOULD
NOT BE AS THICK AS LAST NIGHT AND IS EXPECTED TO BURN OFF QUICKER.

LONG TERM...MAINLY MVFR CONDITIONS EXPECTED.

&&

.MARINE...
SHORT TERM...NO FLAGS EXPECTED.

LONG TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS.

&&

.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 508 PM EDT THU AUG 16 2012

.SYNOPSIS...
DRY WEATHER WILL COME TO AN END TONIGHT AS A COLD FRONT APPROACHES
FROM THE WEST. THE COLD FRONT WILL CROSS THE AREA EARLY FRIDAY,
BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. IN THE WAKE OF
THE FRONT, A COOLER AND DRIER WEEKEND CAN BE EXPECTED.

&&

.NEAR TERM /THROUGH FRIDAY/...
QUICK UPDATE TO ADD SLIGHT CHANCE TO COUNTIES NORTH AND EAST OF
PITTSBURGH AS RANDOM SHOWERS AND STORMS HAVE DEVELOPED WELL AHEAD
OF MAIN ACTIVITY. NO OTHER CHANGES AND PREVIOUS DISCUSSION
FOLLOWS.

AT THE SURFACE, A COLD FRONT EXTENDS SOUTHWARD FROM A SURFACE LOW
THAT IS CENTERED NORTH OF LAKE SUPERIOR. THE FRONT EXTENDS ACROSS
LAKE MICHIGAN AND INTO ILLINOIS. WELL AHEAD OF THIS FEATURE, A
1018MB SURFACE HIGH CENTERED ACROSS WEST VIRGINIA CONTINUES TO
ALLOW FOR MAINLY DRY WEATHER ACROSS THE UPPER OHIO VALLEY.

THIS EVENING..RIDGE AXIS WILL SHIFT EASTWARD AS A SURFACE TROUGH
AND ITS COINCIDENT COLD FRONT APPROACH FROM THE WEST. UPSTREAM
QUASI-LINEAR CONVECTIVE SYSTEM (QLCS) IS ANTICIPATED TO SLIDE
SOUTHEASTWARD AND DIMINISH MOSTLY BEFORE REACHING THE UPPER OHIO
VALLEY. THE RAP INDICATES SBCAPE INCREASING TO AROUND 1500 J/KG
WITH LI VALUES DECREASING TO -1 TO -3 BY LATE EVENING. THIS MAY BE
ENOUGH INSTABILITY TO INSTIGATE A FEW SHOWERS OR STORMS AS
DIMINISHING CONVECTION CROSSES OHIO. THUS, A SCHC IS FORECAST FOR
AREAS NORTHWEST OF PITTSBURGH. FOCUS OF THUNDERSTORMS TO IMPACT
OUR AREA TONIGHT WILL THEN SHIFT TO RIGHT ALONG THE FRONT.

TONIGHT...THE COLD FRONT AND SURFACE TROUGH ARE PROGGED TO MOVE
ACROSS OHIO OVERNIGHT, ENTERING WESTERN PA BY AROUND 12Z ON FRIDAY.
INITIAL QLCS WILL WEAKEN AND THE FOCUS OF CONVECTION SHOULD HAVE
TRANSITIONED CLOSER TO THE ACTUAL FRONT. A MODEL CONSENSUS INDICATES
THAT INSTABILITY WILL BE WEAK OVERNIGHT WITH SBCAPE AND MUCAPE
VALUES LESS THAN 500 J/KG AS THE FRONT CROSSES OHIO. WITH WEAK
SHEAR OVERNIGHT, DO NOT ANTICIPATE A SEVERE THREAT. HOWEVER, THERE
STILL MAY BE ENOUGH LIFT AND MOISTURE TO SUPPORT THUNDERSTORMS AS
THE FRONT MOVES ACROSS. WITH INCREASING LOW-LEVEL MOISTURE,
OVERNIGHT LOWS WILL BE LIMITED TO THE MID TO UPPER 60S ACROSS MOST
OF THE AREA.

FRIDAY...THERE IS MODEL AGREEMENT BETWEEN THE GFS/NAM THAT THE FRONT
AXIS IS PROGGED TO BE ALONG THE RIDGES BY BETWEEN 18Z AND 21Z FRI, AND
AM LEANING TOWARDS THE EARLIER SOLUTION GIVEN UPSTREAM PROGRESSION
OF THE FRONT THUS FAR. THUS, GIVEN THE EARLY PASSAGE OF THE FRONT
AND LIMITED INSTABILITY, BELIEVE IT WILL PASS MOST OF THE AREA AT A
DIURNALLY UNFAVORABLE TIME FOR SEVERE WEATHER. THE SOUTHEASTERN
RIDGES OF WV/MD HAVE THE BEST CHANCE OF A STRONG THUNDERSTORM AS
THE LINE RE-DEVELOPS IN THE LATE MORNING, BUT THE SEVERE THREAT
THERE IS STILL MINIMAL WITH WEAK SHEAR AND THE BEST INSTABILITY
SOUTHEAST OF THE APPALACHIANS. CATEGORICAL POPS ARE FORECAST ALONG
THE FRONT, WITH GENERALLY A QUARTER TO A HALF OF AN INCH OF
RAINFALL ANTICIPATED WITH ITS PASSAGE.

THERE IS SOME UNCERTAINTY WITH HIGH TEMPS ON FRIDAY DEPENDING ON THE
TIMING OF THE FRONT. HIGHS ARE CLOSEST TO THE ECMWF IN THE LOWER TO
MID 70S, WITH LITTLE DIURNAL RANGE FOR MUCH OF THE AREA AS WEAK COLD
AIR ADVECTION BEGINS TO WORK FROM THE NORTHWEST BEHIND THE FRONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
THERE IS GFS/NAM/ECMWF AGREEMENT THAT IN THE WAKE OF THE FRONT A
COOLER AND DRIER AIR MASS WILL BE USHERED INTO THE AREA ON FRIDAY
NIGHT WITH A SURFACE HIGH BUILDING INTO THE OHIO VALLEY. THIS WILL
ALLOW FOR A MOSTLY DRY WEEKEND WITH TEMPS 5 TO 10 DEGREES BELOW
NORMAL.

THE ONE PIECE OF UNCERTAINTY IN THE DRY FORECAST OVER THE WEEKEND IS
A WAVE THAT WILL SWING AROUND THE BASE OF A LONG WAVE TROUGH
CENTERED ACROSS THE GREAT LAKES. THE WAVE WILL MOVE NORTHEAST ALONG
THE APPALACHIANS ON SUNDAY. SCHC SHOWERS ARE FORECAST WITH THIS
FEATURE ACROSS THE SOUTHEASTERN RIDGES GIVEN THE UNCERTAINTY OF
ITS WESTERN EXTENT.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
KEPT MENTION OF ISOLATED SHOWERS ALONG THE RIDGES SUNDAY NIGHT INTO
MONDAY AS AN UPPER TROUGH REMAINS OVER THE GREAT LAKES REGION WHILE
A WEAK SURFACE LOW CROSSES THE SOUTHEASTERN STATES. THE REMAINDER OF
THE EXTENDED PERIOD SHOULD BE DRY AS A SURFACE RIDGE BUILDS EASTWARD
ACROSS THE UPPER OHIO VALLEY.

TEMPERATURES ARE FORECAST TO BE 5 TO 10 DEGREES BELOW NORMAL THROUGH
TUESDAY...THEN RETURN TO NEAR NORMAL BY MIDWEEK.

&&

.AVIATION /21Z THURSDAY THROUGH TUESDAY/...
A LOW PRESSURE SYSTEM CROSSING SOUTHERN ONTARIO WILL PUSH A COLD
FRONT EASTWARD ACROSS THE TERMINALS FRIDAY MORNING. EXPECT VFR
CONDITIONS TO CONTINUE THROUGH THIS EVENING AS BROKEN MID LEVEL
CLOUD DECK AHEAD OF THE FRONT SPREADS ACROSS THE OHIO VALLEY. A BAND
OF RAIN SHOWERS AND EMBEDDED THUNDERSTORMS JUST AHEAD OF AND ALONG
FRONTAL BOUNDARY IS FORECAST TO REACH KZZV BY AROUND 05Z AND WESTERN
PA SITES BY 09Z-12Z FRIDAY. MVFR RESTRICTIONS SHOULD PREVAIL WITH
BRIEF IFR CONDITIONS POSSIBLE IN HEAVIER RAINFALL WITH
THUNDERSTORMS. PRECIPITATION AND RESTRICTIONS SHOULD END BY
18Z-21Z AS SYSTEM PULLS EAST OF THE REGION.

.OUTLOOK/ FRIDAY NIGHT THROUGH TUESDAY/...
GENERALLY VFR WEATHER IS ANTICIPATED UNDER A WEAK SURFACE RIDGE.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 356 PM EDT THU AUG 16 2012

.SYNOPSIS...
DRY WEATHER WILL COME TO AN END TONIGHT AS A COLD FRONT APPROACHES
FROM THE WEST. THE COLD FRONT WILL CROSS THE AREA EARLY ON FRIDAY,
BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. IN THE WAKE OF THE
FRONT, A COOLER AND DRIER WEEKEND CAN BE EXPECTED.

&&

.NEAR TERM /THROUGH FRIDAY/...
THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK 500MB RIDGE AXIS
EXTENDING FROM WESTERN PA INTO EASTERN ONTARIO. DRY MID-LEVELS
ACROSS THE REGION ARE GIVING WAY TO UPSTREAM MOISTURE AS IT
SPILLS AHEAD OF CONVECTION THAT HAS DEVELOPED IN ADVANCE OF A COLD
FRONT. AT THE SURFACE, THE AFOREMENTIONED COLD FRONT EXTENDS
SOUTHWARD FROM A SURFACE LOW THAT IS CENTERED NORTH OF LAKE
SUPERIOR. THE FRONT EXTENDS ACROSS LAKE MICHIGAN AND INTO
ILLINOIS. WELL AHEAD OF THIS FEATURE, A 1018MB SURFACE HIGH
CENTERED ACROSS WEST VIRGINIA CONTINUES TO ALLOW FOR DRY WEATHER
ACROSS THE UPPER OHIO VALLEY.

THIS EVENING..THE RIDGE AXIS WILL SHIFT EASTWARD AS A SURFACE
TROUGH AND ITS COINCIDENT COLD FRONT APPROACH FROM THE WEST.
UPSTREAM QUASI-LINEAR CONVECTIVE SYSTEM (QLCS) IS ANTICIPATED TO
SLIDE SOUTHEASTWARD AND DIMINISH MOSTLY BEFORE REACHING THE UPPER
OHIO VALLEY. THE RAP INDICATES SBCAPE INCREASING TO AROUND 1500
J/KG WITH LI VALUES DECREASING TO -1 TO -3 BY LATE EVENING. THIS
MAY BE ENOUGH INSTABILITY TO INSTIGATE A FEW SHOWERS OR STORMS AS
DIMINISHING CONVECTION CROSSES OHIO. THUS, A SCHC IS FORECAST FOR
AREAS NORTHWEST OF PITTSBURGH. FOCUS OF THUNDERSTORMS TO IMPACT
OUR AREA TONIGHT WILL THEN SHIFT TO RIGHT ALONG THE FRONT.

TONIGHT...THE COLD FRONT AND SURFACE TROUGH ARE PROGGED TO MOVE
ACROSS OHIO OVERNIGHT, ENTERING WESTERN PA BY AROUND 12Z ON FRIDAY.
INITIAL QLCS WILL WEAKEN AND THE FOCUS OF CONVECTION SHOULD HAVE
TRANSITIONED CLOSER TO THE ACTUAL FRONT. A MODEL CONSENSUS INDICATES
THAT INSTABILITY WILL BE WEAK OVERNIGHT WITH SBCAPE AND MUCAPE
VALUES LESS THAN 500 J/KG AS THE FRONT CROSSES OHIO. WITH WEAK
SHEAR OVERNIGHT, DO NOT ANTICIPATE A SEVERE THREAT. HOWEVER, THERE
STILL MAY BE ENOUGH LIFT AND MOISTURE TO SUPPORT THUNDERSTORMS AS
THE FRONT MOVES ACROSS. WITH INCREASING LOW-LEVEL MOISTURE,
OVERNIGHT LOWS WILL BE LIMITED TO THE MID TO UPPER 60S ACROSS MOST
OF THE AREA.

FRIDAY...THERE IS MODEL AGREEMENT BETWEEN THE GFS/NAM THAT THE FRONT
AXIS IS PROGGED TO BE ALONG THE RIDGES BY BETWEEN 18Z AND 21Z FRI, AND
AM LEANING TOWARDS THE EARLIER SOLUTION GIVEN UPSTREAM PROGRESSION
OF THE FRONT THUS FAR. THUS, GIVEN THE EARLY PASSAGE OF THE FRONT
AND LIMITED INSTABILITY, BELIEVE IT WILL PASS MOST OF THE AREA AT A
DIURNALLY UNFAVORABLE TIME FOR SEVERE WEATHER. THE SOUTHEASTERN
RIDGES OF WV/MD HAVE THE BEST CHANCE OF A STRONG THUNDERSTORM AS
THE LINE RE-DEVELOPS IN THE LATE MORNING, BUT THE SEVERE THREAT
THERE IS STILL MINIMAL WITH WEAK SHEAR AND THE BEST INSTABILITY
SOUTHEAST OF THE APPALACHIANS. CATEGORICAL POPS ARE FORECAST ALONG
THE FRONT, WITH GENERALLY A QUARTER TO A HALF OF AN INCH OF
RAINFALL ANTICIPATED WITH ITS PASSAGE.

THERE IS SOME UNCERTAINTY WITH HIGH TEMPS ON FRIDAY DEPENDING ON THE
TIMING OF THE FRONT. HIGHS ARE CLOSEST TO THE ECMWF IN THE LOWER TO
MID 70S, WITH LITTLE DIURNAL RANGE FOR MUCH OF THE AREA AS WEAK COLD
AIR ADVECTION BEGINS TO WORK FROM THE NORTHWEST BEHIND THE FRONT.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
THERE IS GFS/NAM/ECMWF AGREEMENT THAT IN THE WAKE OF THE FRONT A
COOLER AND DRIER AIR MASS WILL BE USHERED INTO THE AREA ON FRIDAY
NIGHT WITH A SURFACE HIGH BUILDING INTO THE OHIO VALLEY. THIS WILL
ALLOW FOR A MOSTLY DRY WEEKEND WITH TEMPS 5 TO 10 DEGREES BELOW
NORMAL.

THE ONE PIECE OF UNCERTAINTY IN THE DRY FORECAST OVER THE WEEKEND IS
A WAVE THAT WILL SWING AROUND THE BASE OF A LONG WAVE TROUGH
CENTERED ACROSS THE GREAT LAKES. THE WAVE WILL MOVE NORTHEAST ALONG
THE APPALACHIANS ON SUNDAY. SCHC SHOWERS ARE FORECAST WITH THIS
FEATURE ACROSS THE SOUTHEASTERN RIDGES GIVEN THE UNCERTAINTY OF
ITS WESTERN EXTENT.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
KEPT MENTION OF ISOLATED SHOWERS ALONG THE RIDGES SUNDAY NIGHT INTO
MONDAY AS AN UPPER TROUGH REMAINS OVER THE GREAT LAKES REGION WHILE
A WEAK SURFACE LOW CROSSES THE SOUTHEASTERN STATES. THE REMAINDER OF
THE EXTENDED PERIOD SHOULD BE DRY AS A SURFACE RIDGE BUILDS EASTWARD
ACROSS THE UPPER OHIO VALLEY.

TEMPERATURES ARE FORECAST TO BE 5 TO 10 DEGREES BELOW NORMAL THROUGH
TUESDAY...THEN RETURN TO NEAR NORMAL BY MIDWEEK.

&&

.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
A LOW PRESSURE SYSTEM CROSSING SOUTHERN ONTARIO WILL PUSH A COLD
FRONT EASTWARD ACROSS THE TERMINALS FRIDAY MORNING. EXPECT VFR
CONDITIONS TO CONTINUE THROUGH THIS EVENING AS BROKEN MID LEVEL
CLOUD DECK AHEAD OF THE FRONT SPREADS ACROSS THE OHIO VALLEY. A BAND
OF RAIN SHOWERS AND EMBEDDED THUNDERSTORMS JUST AHEAD OF AND ALONG
FRONTAL BOUNDARY IS FORECAST TO REACH KZZV BY AROUND 05Z AND WESTERN
PA SITES BY 09Z-12Z FRIDAY. MVFR RESTRICTIONS SHOULD PREVAIL WITH
BRIEF IFR CONDITIONS POSSIBLE IN HEAVIER RAINFALL WITH
THUNDERSTORMS. PRECIPITATION AND RESTRICTIONS SHOULD END BY
18Z-21Z AS SYSTEM PULLS EAST OF THE REGION.

.OUTLOOK/ FRIDAY NIGHT THROUGH TUESDAY/...
GENERALLY VFR WEATHER IS ANTICIPATED UNDER A WEAK SURFACE RIDGE.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 1201 PM EDT THU AUG 16 2012

.SYNOPSIS...
DRY WEATHER WILL COME TO AN END TONIGHT AS A COLD FRONT APPROACHES
FROM THE WEST. THE COLD FRONT WILL CROSS THE AREA EARLY ON FRIDAY,
BRINGING SHOWERS AND THUNDERSTORMS TO THE REGION. IN THE WAKE OF THE
FRONT, A COOLER AND DRIER WEEKEND CAN BE EXPECTED.

&&

.NEAR TERM /UNTIL 8 PM THIS EVENING/...
AN ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO MAKE THE
ONSET OF THE CHANCE OF SHOWERS AND THUNDERSTORMS EARLIER TONIGHT.

THE LATEST RAP MID-LEVEL ANALYSIS INDICATES A WEAK 500MB RIDGE AXIS
EXTENDING FROM THE OHIO VALLEY INTO EASTERN ONTARIO. DRY MID-LEVELS
ACROSS THE REGION ARE ABOUT TO GIVE WAY TO UPSTREAM MOISTURE AS IT
SPILLS AHEAD OF THE MCS DEVELOPING WITH A COLD FRONT. AT THE
SURFACE, THE AFOREMENTIONED COLD FRONT EXTENDS SOUTHWARD FROM A
SURFACE LOW THAT IS CENTERED NORTH OF LAKE SUPERIOR. THE FRONT
EXTENDS ACROSS THE UPPER MIDWEST AND INTO MISSOURI. WELL AHEAD OF
THIS FEATURE, A 1019MB SURFACE HIGH CENTERED ACROSS WEST VIRGINIA
CONTINUES TO ALLOW FOR DRY WEATHER ACROSS THE UPPER OHIO VALLEY.

THIS AFTERNOON...THE RIDGE AXIS WILL SHIFT EASTWARD TODAY AS A
SURFACE TROUGH AND ITS COINCIDENT COLD FRONT APPROACH FROM THE WEST.
UPSTREAM CONVECTION IS ANTICIPATED TO WEAKEN MOSTLY BEFORE REACHING THE
UPPER OHIO VALLEY. THE RAP INDICATES SBCAPE INCREASING TO 500-1000
J/KG WITH LI VALUES DECREASING TO -1 TO -3 BY LATE EVENING. THIS
MAY BE ENOUGH INSTABILITY TO MAINTAIN A FEW STORMS AS THE WEAKENING
CONVECTION CROSSES OHIO. THUS, A SCHC HAS BEEN MOVED UP TO 21Z
ACROSS AREAS WEST OF PITTSBURGH. WARM AIR ADVECTION WILL BE
ONGOING TODAY, ALLOWING FOR 850MB TEMPS TO INCREASE TO 16-17C.
THUS, HIGHS TODAY WILL BE AROUND 5 DEGREES ABOVE NORMAL, WELL INTO
THE MID 80S ACROSS MOST OF THE AREA.

&&

.SHORT TERM /8 PM THIS EVENING THROUGH SUNDAY/...
LATEST MODEL RUNS REMAIN IN GENERAL AGREEMENT IN HANDLING THE
APPROACH AND PASSAGE OF AN UPPER TROUGH AND THE ASSOCIATED COLD
FRONT TONIGHT AND FRIDAY.

WARM...MOIST ADVECTION AND INCREASING ASCENT IN ADVANCE OF THAT
SYSTEM SUPPORT SCATTERED PRECIP PROBABILITIES BEGINNING TONIGHT...AND
RESULT IN LIKELY NUMBERS WITH THE PASSAGE OF THE COLD FRONT ON
FRIDAY. ALTHOUGH DEEP LAYER SHEAR VALUES ARE FORECAST TO INCREASE
CONSIDERABLY WITH THE QUICKENING FLOW ALOFT...CURRENT THOUGHTS ARE
THAT TIMING OF THE FRONTAL PASSAGE SHOULD LIMIT INSTABILITY
BUILDUP AND PRECLUDE SEVERE STORMS.

THEREAFTER...HAVE PERSISTED IN THE PREVIOUSLY FORECAST FRIDAY
AFTERNOON AND EVENING POP DIMINISHMENT IN ACCORDANCE WITH THE
EXPECTED EXIT OF THE SYSTEM.

A CLOSED UPPER LOW IS PROGGED TO REMAIN PARKED OVER JAMES BAY
THROUGH THE WEEKEND WITH A BROAD TROUGH HOLDING OVER THE EASTERN CONUS.
THIS PATTERN WILL MAINTAIN SUB NORMAL POST FRONTAL TEMPERATURES AS
SURFACE RIDGING AND DRY ADVECTION YIELD GENERALLY DRY CONDITIONS.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
SEASONABLY COOL AND GENERALLY DRY WEATHER IS FORECAST AS A BROAD
UPPER LEVEL TROUGH REMAINS ENTRENCHED OVER THE REGION WITH WEAK
SURFACE RIDGING. KEPT POPS IN THE SLIGHT CHANCE RANGE...BELOW 25
PERCENT THROUGH THE PERIOD.

&&

.AVIATION /16Z THURSDAY THROUGH MONDAY/...
CONSIDERING MOSTLY SUNNY SKIES AND MODERATE WINDS ON
WEDNESDAY...SOME LOW LEVEL DRYING SHOULD HAVE OCCURRED...SO DO NOT
ANTICIPATE THAT ANY SITES WOULD HAVE CONDITIONS LOWER THIS MORNING
THAN THEY DID YESTERDAY MORNING. STILL THINK THAT MOST SITES WILL
HAVE A FAIR CHANCE OF DROPPING TO IFR...ALTHOUGH GUIDANCE IS MORE
OPTIMISTIC IN THE MVFR/VFR RANGE. ANY FOG WILL DISSIPATE BY MID
MORNING...WITH VFR CONDITIONS EXPECTED FOR THE REST OF THE TAF
PERIOD.

.OUTLOOK...
MVFR/IFR RESTRICTIONS ARE POSSIBLE FRIDAY IN SHOWERS AND
THUNDERSTORMS WITH THE NEXT COLD FRONT. GENERAL VFR IS ANTICIPATED
UNDER WEEKEND SURFACE HIGH PRESSURE.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 334 PM EDT THU AUG 16 2012

.SYNOPSIS...
ISSUED AT 333 PM EDT THU AUG 16 2012

A STRONG COLD FRONT COMING THROUGH SOUTHWEST MICHIGAN THIS EVENING
WILL BRING UNSEASONABLY COOL TEMPERATURES TO THE AREA THROUGH THE WEEKEND.
A SLOW WARMING TREND WILL BEGIN BY TUESDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 333 PM EDT THU AUG 16 2012

THE BIGGEST ISSUE IS WILL MORE CONVECTION DEVELOP BEFORE THE FRONT
COMES THROUGH EARLY THIS EVENING? OTHER THAN THAT A LARGE CLOSED
UPPER LOW OVER SOUTHERN HUDSON BAY WILL FEED UNSEASONABLY COOL
WEATHER INTO THE AREA THROUGH THROUGH THE SHORT TERM.

THE LARGE AREA OF RAIN COOLED AIR FROM THE MORNING SQUALL LINE HAS
CREATED A LARGE POCKET OF COOL AIR AHEAD OF THE SURFACE COLD
FRONT. MIX LAYER CAPES OVER SOUTHWEST LOWER MICHIGAN AT 3 PM WERE
UNDER 300 J/KG. SO EVEN WITH THE 40 TO 60 KNOTS OF DEEP LAYER
SHEAR AND STRONG SURFACE WIND CONVERGENCE ON THE FRONT... LITTLE
HAS DEVELOPED ON THE FRONT AS OF YET. I DO BELIEVE THE AREA SOUTH
AND EAST OF I-69 WILL HAVE TO BE WATCHED EARLY THIS EVENING AS THE
RAP SHOWS MIX LAYER CAPES RISING IN THAT AREA TO 500 J/KG THERE.
STILL NOT ALL THAT GREAT THROUGH. ALSO THE HRRR RUC SHOWS A LINE
DEVELOPING BETWEEN 22Z AND 01Z MOVING EAST AND INCREASING THROUGH
02Z AS IT EXITS THE SE CWA. I REMAIN UNIMPRESSED SO I HAVE ONLY
30-40 PCT POPS INTO EARLY THIS EVENING.

AFTER THAT A HIGH PRESSURE RIDGE BUILDS IN AND THAT SHOULD HELP TO
CLEAR OUT ANY RESIDUAL LOW CLOUDS THAT NOW COVER MOST OF WI
BEHIND THE FRONT BY MID MORNING FRIDAY. THE AIR REMAINS TO DRY FOR
LAKE EFFECT RAIN SHOWERS SO I KEPT THE FORECAST DRY THROUGH
SATURDAY.

WITH LIGHT WINDS AND DRY AIR WE COULD SEE LOWS IN THE 30S NEAR AND
NORTH OF ROUTE 10 SATURDAY MORNING. STILL THE DEW POINTS WILL BE
TO HIGH FOR FROST SO THAT SHOULD NOT BE MUCH OF A PROBLEM.


.LONG TERM...(SUNDAY THROUGH THURSDAY)
ISSUED AT 333 PM EDT THU AUG 16 2012

COOL WX WILL CONTINUE SUNDAY AND MONDAY BEFORE TEMPS MODERATE TO
NEAR NORMAL TUESDAY THROUGH THURSDAY. THE UPPER LEVEL TROUGH AND
COLD POOL OF AIR ALOFT IN CONJUNCTION WITH SEVERAL SHORTWAVES
ROTATING AROUND THE UPPER LOW AND SOME SUN WILL COMBINE TO PRODUCE
SCATTERED DIURNALLY DRIVEN SHOWERS SUNDAY AND MONDAY (MAINLY DURING
THE AFTERNOON AND EARLY EVENING).

MAX TEMPS SUNDAY AND MONDAY WILL ONLY REACH THE 70 TO 75 DEGREE
RANGE. DRY AND MILDER WX IS ANTICIPATED TUESDAY THROUGH WEDNESDAY
WITH MAX TEMPS BACK NEAR NORMAL IN THE UPPER 70S TO LOWER 80S. THE
NEXT LOW PRESSURE SYSTEM TO IMPACT OUR AREA WILL BRING A CHC OF
SHOWERS AND TSTORMS BY LATE NEXT WEEK.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY)
ISSUED AT 120 PM EDT THU AUG 16 2012

PRIMARILY MVFR CIGS ARE ANTICIPATED THIS AFTERNOON THROUGH THIS
EVENING WITH EXTENSIVE LOW CLOUD COVER NOTED OFF TO THE WEST. RADAR
TRENDS INDICATE SHOWERS WILL LINGER AT KLAN/KJXN THRU MID AFTN
BEFORE EXITING. THERE IS POTENTIAL FOR A FEW MORE SHOWERS TO DEVELOP
ALONG AND JUST AHEAD OF THE COLD FRONT LATE THIS AFTN/EARLY EVE
MAINLY AT KLAN/KJXN.

CONDITIONS WILL GRADUALLY TRANSITION FROM MAINLY MVFR TO VFR
OVERNIGHT WITH CIGS EXPECTED TO SLOWLY INCREASE TO AROUND 3500-4000
KFT AGL.


&&

.MARINE...
ISSUED AT 333 PM EDT THU AUG 16 2012

ENOUGH WIND AND COLD AIR TO KEEP THE WAVES 3 TO 6 FEET INTO FRIDAY
AFTERNOON SO I WILL CONTINUE OUR BEACH HAZARD EVENT AND SC AS IS.
IT SHOULD BE NOTED THAT THE LUDINGTON BUOY HAD WAVE HEIGHTS AS
HIGH AS 7 FEET THIS MORNING.

&&

.HYDROLOGY...
ISSUED AT 333 PM EDT THU AUG 16 2012

RAINFALL WAS FOR THE MOST PART BETWEEN .3 AND .7 INCHES OF MOST OF
THE WESTERN AND CENTRAL CWA WITH LESSER AMOUNTS TO THE EAST AND
SOUTHEAST. THIS WAS NOT ENOUGH TO CAUSE ANY RIVER RISE ISSUES BUT
SHOULD BE ENOUGH TO MITIGATE DROUGHT ISSUES.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH FRIDAY AFTERNOON FOR MIZ037-043-
     050-056-064-071.

LM...SMALL CRAFT ADVISORY UNTIL 5 PM EDT FRIDAY FOR LMZ844>849.

&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...LAURENS
AVIATION...LAURENS
HYDROLOGY...WDM
MARINE...WDM







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 132 PM EDT THU AUG 16 2012

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 559 AM EDT THU AUG 16 2012

MAIN FCST PROBLEMS FOCUS ON COVERAGE OF SHRA/TSRA ALONG COLD FRONT
AS IT MOVES THROUGH CENTRAL/ERN UPR MI THIS MORNING INTO EARLY
AFTERNOON...POSSIBILITY OF LINGERING INSTABILITY SHRA AND LAKE
EFFECT SHRA IN WAKE OF FRONT THIS AFTERNOON INTO EARLY FRIDAY...AND
GOOD POTENTIAL FOR ADVISORY W-NW WINDS OVER THE KEWEENAW PENINSULA
THIS AFTERNOON INTO THIS EVENING AND THEN OVER SHORELINE AREAS OF
ALGER AND LUCE COUNTIES TONIGHT.

WV IMAGERY AND RUC ANALYSIS SHOWS WELL-DEFINED VIGOROUS NEG-TILT
SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO. AT THE SFC...A COLD
FRONT EXTENDS SOUTH FROM THIS SYSTEM THROUGH WRN UPR MI AND NW WI.
MOISTURE CONVERGENCE AND INSTABILITY ALONG THIS FRONT HAVE SUPPORTED
SCT SHRA/TSRA ALONG THIS FRONT OVER WRN UPR MI AND NOW OVR FAR
SCNTRL UPR MI IN THE PAST HR.

TODAY AND TONIGHT...SHOWERS AND ISOLD TSRA OVER NCNTRL UPR MI HAVE
DISSIPATED OR MOVED NORTH OVER LAKE SUPERIOR IN PAST HR AS
INSTABILITY HAS WEAKENED ALONG/AHEAD OF COLD FRONT. DYNAMICS WITH
ONTARIO SHORTWAVE WILL SUSTAIN SHOWERS OVER ERN LAKE SUPERIOR THIS
MORNING INTO EARLY AFTERNOON. RUC HAS FCST MLCAPES INCREASING TO
200-400 J/KG OVER THE EAST HALF OF FCST AREA LATE THIS MORNING ALONG
COLD FRONT WHICH SHOULD SUSTAIN SCT TO NMRS SHRA/TSRA INTO EARLY
AFTERNOON UNTIL COLD FRONT PASSES EAST. LINGERING WEAK DIURNAL
INSTABILITY IN LOW-LVLS AND STEEP SFC-8H LAPSE RATES AS NOTED ON
NAM/RUC FCST SNDGS COULD SUPPORT SOME ISOLD SHRA INTO THE EARLY
AFTERNOON AS MID-LVL TROUGH MOVES OVERHEAD. SOME SCT LAKE EFFECT
SHRA COULD ALSO DEVELOP THIS AFTERNOON OVER WRN COUNTIES IN CYCLONIC
NW FLOW AS LAKE SFC DELTA-T/S WILL INCREASE NEAR 13-14C AS 8H TEMPS
DROP TO 5-6C OVER WRN LAKE SUPERIOR.

BIGGER CONCERN MAY BE POTENTIAL FOR ADVISORY WINDS OVER THE KEWEENAW
PENINSULA AND SHORELINE AREAS OF ALGER LUCE COUNTIES THIS AFTERNOON
INTO TONIGHT. MODELS PARTICULARLY NAM SUGGEST AN AREA OF PRES RISES
(4-5 MB OVER 6HR PERIOD) COMBINED WITH PASSAGE OF SECONDARY COLD
FRONT AND INCREASING INSTABILITY SHOULD ALLOW 35-40 KT TO MIX TO
SFC. HAVE POSTED WIND ADVISORY OVER THE NRN HOUGHTON-KEWEENAW FOR
THIS AFTERNOON INTO THIS EVENING AND OVER SHORELINE AREAS OF ALGER
AND LUCE COUNTIES TONIGHT.

CONTINUED COLD ADVECTION AS 8H TEMPS DROP TO 3-5C TONIGHT IN
CYCLONIC NW FLOW WILL CONTINUE TO SUPPORT LINGERING LAKE EFFECT RAIN
SHOWERS DOWNWIND OF LAKE SUPERIOR ESPECIALLY OVER ERN COUNTIES WHERE
FETCH WILL BE LONGER ACROSS THE LAKE.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 559 AM EDT THU AUG 16 2012

NAM SHOWS A CLOSED 500 MB LOW NEAR JAMES BAY ON FRIDAY AND IT DOES
NOT MOVE MUCH SAT NIGHT. A RIDGE OVER THE WESTERN U.S. SLOWLY MOVES
EAST INTO THE ROCKIES WITH TIME. THERE ARE ALSO NUMEROUS WEAK
SHORTWAVES ROTATING AROUND THE CLOSED 500 MB LOW OVER NE ONTARIO IN
THE DEEP TROUGH THAT IS OVER THE ERN U.S. TIMING THESE WILL BE
DIFFICULT AND THESE WEAK SHORTWAVES COULD KICK OFF SOME
SHOWERS...ESPECIALLY DIURNAL HEATING OF THE DAY SHOWERS. DID NOT
MAKE TOO MANY CHANGES TO THE GOING FORECAST. MADE JUST A FEW
ADJUSTMENTS TO TEMPERATURES HERE AND THERE. SLIGHT CHANCE POPS FOR
LATE FRI NIGHT INTO SATURDAY LOOK GOOD ESPECIALLY OVER THE EASTERN
CWA AS ANOTHER SHORTWAVE LOOKS TO BE MOVING THROUGH.

IN THE EXTENDED...GFS AND ECMWF HAVE A DEEP TROUGH OVER THE EASTERN
HALF OF N.A. WITH A RIDGE IN THE WESTERN HALF 12Z SUN. PATTERN DOES
NOT CHANGE UNTIL TUE WHEN THE RIDGE MOVES INTO THE ROCKIES AND THE
TROUGH OVER THE ERN U.S. STARTS TO HEAD EAST AND DE-AMPLIFY A BIT.
COLDER THAN NORMAL TEMPERATURES WILL BEGIN THE PERIOD WITH A SLOW
WARM-UP THIS PERIOD. WITH TROUGHING IN THE AREA THROUGH
MONDAY...DIURNAL SHOWERS ARE DEFINITELY POSSIBLE. A SHORTWAVE
AFFECTS THE AREA FOR WED AND WILL HAVE SLIGHT CHANCE TO LOW CHANCE
POPS IN. TEMPERATURES WARM BACK TO NEAR NORMAL ON TUE AND WED. WILL
CONTINUE DRY FOR MONDAY NIGHT AND TUESDAY.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 131 PM EDT THU AUG 16 2012

BEHIND A COLD FRONT THAT MOVED THROUGH THIS MORNING...WNW WINDS WILL
ADVECT COOLER AND MOISTER LOW LEVEL AIR INTO THE AREA...RESULTING IN
LOW CLOUDS/MVFR CONDITIONS AND STRENGTHENING WINDS. THE STRONGER
WINDS AOA 35KTS AND BETTER CHANCE FOR UPSLOPE/LAKE EFFECT SHRA WILL
BE AT CMX AND IWD WITH MORE PRONOUNCED UPSLOPE WIND COMPONENTS.
EXPECT THESE LOW CIGS TO SLOWLY LIFT TONIGHT.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 559 AM EDT THU AUG 16 2012

AS A COLD FRONT MOVES THROUGH LAKE SUPERIOR THIS MORNING...EXPECT A
SHARP WIND SHIFT TO THE WEST FOLLOWING THIS FRONTAL PASSAGE. THE
ARRIVAL OF MUCH COOLER AIR IN THE WAKE OF THE FRONT OVER THE WARM
WATERS OF LAKE SUPERIOR WILL ALSO RESULT IN ENHANCED MIXING OVER THE
LAKE WITH W-NW WINDS UP TO 30 KTS AND GALES TO 40 KNOTS OVER MOST OF
LAKE SUPERIOR THIS AFTERNOON THROUGH TONIGHT AND HAVE POSTED A GALE
WARNING FOR THIS. EXPECT THE STRONGER NW WINDS TO SLOWLY SUBSIDE ON
FRI THRU THE WEEKEND AS THE PRES GRADIENT WEAKENS WITH BROAD HIGH
PRESSURE SETTLING OVER THE REGION. THERE IS ALSO AN INCREASED RISK
OF RIP CURRENTS IN MARQUETTE AND ALGER COUNTIES THROUGH FRIDAY WITH
STRONG NORTHWEST WINDS AND HIGH WAVES.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WIND ADVISORY UNTIL MIDNIGHT EDT TONIGHT FOR MIZ001-003.

  WIND ADVISORY FROM 9 PM THIS EVENING TO 8 AM EDT FRIDAY FOR
     MIZ006-007.

LAKE SUPERIOR...
  GALE WARNING FROM 10 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
     LSZ267.

  GALE WARNING UNTIL 10 AM EDT FRIDAY FOR LSZ264>266.

  GALE WARNING UNTIL 1 AM EDT FRIDAY FOR LSZ263.

  GALE WARNING FROM 8 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
     LSZ249>251.

  GALE WARNING UNTIL MIDNIGHT EDT TONIGHT FOR LSZ242-243.

  GALE WARNING UNTIL 8 AM EDT FRIDAY FOR LSZ244-245.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...07
AVIATION...TITUS
MARINE...07







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 758 AM EDT THU AUG 16 2012

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 559 AM EDT THU AUG 16 2012

MAIN FCST PROBLEMS FOCUS ON COVERAGE OF SHRA/TSRA ALONG COLD FRONT
AS IT MOVES THROUGH CENTRAL/ERN UPR MI THIS MORNING INTO EARLY
AFTERNOON...POSSIBILITY OF LINGERING INSTABILITY SHRA AND LAKE
EFFECT SHRA IN WAKE OF FRONT THIS AFTERNOON INTO EARLY FRIDAY...AND
GOOD POTENTIAL FOR ADVISORY W-NW WINDS OVER THE KEWEENAW PENINSULA
THIS AFTERNOON INTO THIS EVENING AND THEN OVER SHORELINE AREAS OF
ALGER AND LUCE COUNTIES TONIGHT.

WV IMAGERY AND RUC ANALYSIS SHOWS WELL-DEFINED VIGOROUS NEG-TILT
SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO. AT THE SFC...A COLD
FRONT EXTENDS SOUTH FROM THIS SYSTEM THROUGH WRN UPR MI AND NW WI.
MOISTURE CONVERGENCE AND INSTABILITY ALONG THIS FRONT HAVE SUPPORTED
SCT SHRA/TSRA ALONG THIS FRONT OVER WRN UPR MI AND NOW OVR FAR
SCNTRL UPR MI IN THE PAST HR.

TODAY AND TONIGHT...SHOWERS AND ISOLD TSRA OVER NCNTRL UPR MI HAVE
DISSIPATED OR MOVED NORTH OVER LAKE SUPERIOR IN PAST HR AS
INSTABILITY HAS WEAKENED ALONG/AHEAD OF COLD FRONT. DYNAMICS WITH
ONTARIO SHORTWAVE WILL SUSTAIN SHOWERS OVER ERN LAKE SUPERIOR THIS
MORNING INTO EARLY AFTERNOON. RUC HAS FCST MLCAPES INCREASING TO
200-400 J/KG OVER THE EAST HALF OF FCST AREA LATE THIS MORNING ALONG
COLD FRONT WHICH SHOULD SUSTAIN SCT TO NMRS SHRA/TSRA INTO EARLY
AFTERNOON UNTIL COLD FRONT PASSES EAST. LINGERING WEAK DIURNAL
INSTABILITY IN LOW-LVLS AND STEEP SFC-8H LAPSE RATES AS NOTED ON
NAM/RUC FCST SNDGS COULD SUPPORT SOME ISOLD SHRA INTO THE EARLY
AFTERNOON AS MID-LVL TROUGH MOVES OVERHEAD. SOME SCT LAKE EFFECT
SHRA COULD ALSO DEVELOP THIS AFTERNOON OVER WRN COUNTIES IN CYCLONIC
NW FLOW AS LAKE SFC DELTA-T/S WILL INCREASE NEAR 13-14C AS 8H TEMPS
DROP TO 5-6C OVER WRN LAKE SUPERIOR.

BIGGER CONCERN MAY BE POTENTIAL FOR ADVISORY WINDS OVER THE KEWEENAW
PENINSULA AND SHORELINE AREAS OF ALGER LUCE COUNTIES THIS AFTERNOON
INTO TONIGHT. MODELS PARTICULARLY NAM SUGGEST AN AREA OF PRES RISES
(4-5 MB OVER 6HR PERIOD) COMBINED WITH PASSAGE OF SECONDARY COLD
FRONT AND INCREASING INSTABILITY SHOULD ALLOW 35-40 KT TO MIX TO
SFC. HAVE POSTED WIND ADVISORY OVER THE NRN HOUGHTON-KEWEENAW FOR
THIS AFTERNOON INTO THIS EVENING AND OVER SHORELINE AREAS OF ALGER
AND LUCE COUNTIES TONIGHT.

CONTINUED COLD ADVECTION AS 8H TEMPS DROP TO 3-5C TONIGHT IN
CYCLONIC NW FLOW WILL CONTINUE TO SUPPORT LINGERING LAKE EFFECT RAIN
SHOWERS DOWNWIND OF LAKE SUPERIOR ESPECIALLY OVER ERN COUNTIES WHERE
FETCH WILL BE LONGER ACROSS THE LAKE.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 559 AM EDT THU AUG 16 2012

NAM SHOWS A CLOSED 500 MB LOW NEAR JAMES BAY ON FRIDAY AND IT DOES
NOT MOVE MUCH SAT NIGHT. A RIDGE OVER THE WESTERN U.S. SLOWLY MOVES
EAST INTO THE ROCKIES WITH TIME. THERE ARE ALSO NUMEROUS WEAK
SHORTWAVES ROTATING AROUND THE CLOSED 500 MB LOW OVER NE ONTARIO IN
THE DEEP TROUGH THAT IS OVER THE ERN U.S. TIMING THESE WILL BE
DIFFICULT AND THESE WEAK SHORTWAVES COULD KICK OFF SOME
SHOWERS...ESPECIALLY DIURNAL HEATING OF THE DAY SHOWERS. DID NOT
MAKE TOO MANY CHANGES TO THE GOING FORECAST. MADE JUST A FEW
ADJUSTMENTS TO TEMPERATURES HERE AND THERE. SLIGHT CHANCE POPS FOR
LATE FRI NIGHT INTO SATURDAY LOOK GOOD ESPECIALLY OVER THE EASTERN
CWA AS ANOTHER SHORTWAVE LOOKS TO BE MOVING THROUGH.

IN THE EXTENDED...GFS AND ECMWF HAVE A DEEP TROUGH OVER THE EASTERN
HALF OF N.A. WITH A RIDGE IN THE WESTERN HALF 12Z SUN. PATTERN DOES
NOT CHANGE UNTIL TUE WHEN THE RIDGE MOVES INTO THE ROCKIES AND THE
TROUGH OVER THE ERN U.S. STARTS TO HEAD EAST AND DE-AMPLIFY A BIT.
COLDER THAN NORMAL TEMPERATURES WILL BEGIN THE PERIOD WITH A SLOW
WARM-UP THIS PERIOD. WITH TROUGHING IN THE AREA THROUGH
MONDAY...DIURNAL SHOWERS ARE DEFINITELY POSSIBLE. A SHORTWAVE
AFFECTS THE AREA FOR WED AND WILL HAVE SLIGHT CHANCE TO LOW CHANCE
POPS IN. TEMPERATURES WARM BACK TO NEAR NORMAL ON TUE AND WED. WILL
CONTINUE DRY FOR MONDAY NIGHT AND TUESDAY.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 758 AM EDT THU AUG 16 2012

A COLD FRONT MOVING ACROSS THE AREA WL BRING THE THREAT OF SHRA AND
PERHAPS A TS TO KSAW THIS MORNING. HOWEVER...CONFIDENCE IS LOW THAT
A TSRA WILL MOVE DIRECTLY OVER THE AIRPORT SO DID NOT INCLUDE AN
EXPLICIT MENTION IN TAF. BEHIND THE FROPA AT KIWD AND KCMX...A WSHFT
TO THE WNW WL ADVECT COOLER AND MOISTER LLVL AIR INTO THE
AREA...RESULTING IN LO CLDS/MVFR CONDITIONS AND STRENGTHENING WINDS.
THE STRONGER WINDS AOA 35 KT AND BETTER CHC FOR UPSLOPE/LAKE EFFECT
SHRA WL BE AT THE MORE EXPOSED CMX SITE WITH A MORE PRONOUNCED
UPSLOPE WIND COMPONENT. EXPECT THESE LO CIGS TO SLOWLY LIFT LATE
THIS AFTERNOON AND TONIGHT REACHING VFR AT KIWD TOWARD EVENING AND
VFR AT KCMX OVERNIGHT.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 559 AM EDT THU AUG 16 2012

AS A COLD FRONT MOVES THROUGH LAKE SUPERIOR THIS MORNING...EXPECT A
SHARP WIND SHIFT TO THE WEST FOLLOWING THIS FRONTAL PASSAGE. THE
ARRIVAL OF MUCH COOLER AIR IN THE WAKE OF THE FRONT OVER THE WARM
WATERS OF LAKE SUPERIOR WILL ALSO RESULT IN ENHANCED MIXING OVER THE
LAKE WITH W-NW WINDS UP TO 30 KTS AND GALES TO 40 KNOTS OVER MOST OF
LAKE SUPERIOR THIS AFTERNOON THROUGH TONIGHT AND HAVE POSTED A GALE
WARNING FOR THIS. EXPECT THE STRONGER NW WINDS TO SLOWLY SUBSIDE ON
FRI THRU THE WEEKEND AS THE PRES GRADIENT WEAKENS WITH BROAD HIGH
PRESSURE SETTLING OVER THE REGION. THERE IS ALSO AN INCREASED RISK
OF RIP CURRENTS IN MARQUETTE AND ALGER COUNTIES THROUGH FRIDAY WITH
STRONG NORTHWEST WINDS AND HIGH WAVES.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WIND ADVISORY FROM 1 PM THIS AFTERNOON TO MIDNIGHT EDT TONIGHT
     FOR MIZ001-003.

  WIND ADVISORY FROM 9 PM THIS EVENING TO 8 AM EDT FRIDAY FOR
     MIZ006-007.

LAKE SUPERIOR...
  GALE WARNING FROM 10 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
     LSZ267.

  GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 AM EDT FRIDAY FOR
     LSZ264>266.

  GALE WARNING FROM 1 PM THIS AFTERNOON TO 1 AM EDT FRIDAY FOR
     LSZ263.

  GALE WARNING FROM 2 PM THIS AFTERNOON TO 8 PM EDT THIS EVENING
     FOR LSZ244-245.

  GALE WARNING FROM 11 AM THIS MORNING TO 8 PM EDT THIS EVENING
     FOR LSZ242-243.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...07
AVIATION...VOSS
MARINE...07







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 600 AM EDT THU AUG 16 2012

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 559 AM EDT THU AUG 16 2012

MAIN FCST PROBLEMS FOCUS ON COVERAGE OF SHRA/TSRA ALONG COLD FRONT
AS IT MOVES THROUGH CENTRAL/ERN UPR MI THIS MORNING INTO EARLY
AFTERNOON...POSSIBILITY OF LINGERING INSTABILITY SHRA AND LAKE
EFFECT SHRA IN WAKE OF FRONT THIS AFTERNOON INTO EARLY FRIDAY...AND
GOOD POTENTIAL FOR ADVISORY W-NW WINDS OVER THE KEWEENAW PENINSULA
THIS AFTERNOON INTO THIS EVENING AND THEN OVER SHORELINE AREAS OF
ALGER AND LUCE COUNTIES TONIGHT.

WV IMAGERY AND RUC ANALYSIS SHOWS WELL-DEFINED VIGOROUS NEG-TILT
SHORTWAVE TROUGH MOVING THROUGH NRN ONTARIO. AT THE SFC...A COLD
FRONT EXTENDS SOUTH FROM THIS SYSTEM THROUGH WRN UPR MI AND NW WI.
MOISTURE CONVERGENCE AND INSTABILITY ALONG THIS FRONT HAVE SUPPORTED
SCT SHRA/TSRA ALONG THIS FRONT OVER WRN UPR MI AND NOW OVR FAR
SCNTRL UPR MI IN THE PAST HR.

TODAY AND TONIGHT...SHOWERS AND ISOLD TSRA OVER NCNTRL UPR MI HAVE
DISSIPATED OR MOVED NORTH OVER LAKE SUPERIOR IN PAST HR AS
INSTABILITY HAS WEAKENED ALONG/AHEAD OF COLD FRONT. DYNAMICS WITH
ONTARIO SHORTWAVE WILL SUSTAIN SHOWERS OVER ERN LAKE SUPERIOR THIS
MORNING INTO EARLY AFTERNOON. RUC HAS FCST MLCAPES INCREASING TO
200-400 J/KG OVER THE EAST HALF OF FCST AREA LATE THIS MORNING ALONG
COLD FRONT WHICH SHOULD SUSTAIN SCT TO NMRS SHRA/TSRA INTO EARLY
AFTERNOON UNTIL COLD FRONT PASSES EAST. LINGERING WEAK DIURNAL
INSTABILITY IN LOW-LVLS AND STEEP SFC-8H LAPSE RATES AS NOTED ON
NAM/RUC FCST SNDGS COULD SUPPORT SOME ISOLD SHRA INTO THE EARLY
AFTERNOON AS MID-LVL TROUGH MOVES OVERHEAD. SOME SCT LAKE EFFECT
SHRA COULD ALSO DEVELOP THIS AFTERNOON OVER WRN COUNTIES IN CYCLONIC
NW FLOW AS LAKE SFC DELTA-T/S WILL INCREASE NEAR 13-14C AS 8H TEMPS
DROP TO 5-6C OVER WRN LAKE SUPERIOR.

BIGGER CONCERN MAY BE POTENTIAL FOR ADVISORY WINDS OVER THE KEWEENAW
PENINSULA AND SHORELINE AREAS OF ALGER LUCE COUNTIES THIS AFTERNOON
INTO TONIGHT. MODELS PARTICULARLY NAM SUGGEST AN AREA OF PRES RISES
(4-5 MB OVER 6HR PERIOD) COMBINED WITH PASSAGE OF SECONDARY COLD
FRONT AND INCREASING INSTABILITY SHOULD ALLOW 35-40 KT TO MIX TO
SFC. HAVE POSTED WIND ADVISORY OVER THE NRN HOUGHTON-KEWEENAW FOR
THIS AFTERNOON INTO THIS EVENING AND OVER SHORELINE AREAS OF ALGER
AND LUCE COUNTIES TONIGHT.

CONTINUED COLD ADVECTION AS 8H TEMPS DROP TO 3-5C TONIGHT IN
CYCLONIC NW FLOW WILL CONTINUE TO SUPPORT LINGERING LAKE EFFECT RAIN
SHOWERS DOWNWIND OF LAKE SUPERIOR ESPECIALLY OVER ERN COUNTIES WHERE
FETCH WILL BE LONGER ACROSS THE LAKE.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 559 AM EDT THU AUG 16 2012

NAM SHOWS A CLOSED 500 MB LOW NEAR JAMES BAY ON FRIDAY AND IT DOES
NOT MOVE MUCH SAT NIGHT. A RIDGE OVER THE WESTERN U.S. SLOWLY MOVES
EAST INTO THE ROCKIES WITH TIME. THERE ARE ALSO NUMEROUS WEAK
SHORTWAVES ROTATING AROUND THE CLOSED 500 MB LOW OVER NE ONTARIO IN
THE DEEP TROUGH THAT IS OVER THE ERN U.S. TIMING THESE WILL BE
DIFFICULT AND THESE WEAK SHORTWAVES COULD KICK OFF SOME
SHOWERS...ESPECIALLY DIURNAL HEATING OF THE DAY SHOWERS. DID NOT
MAKE TOO MANY CHANGES TO THE GOING FORECAST. MADE JUST A FEW
ADJUSTMENTS TO TEMPERATURES HERE AND THERE. SLIGHT CHANCE POPS FOR
LATE FRI NIGHT INTO SATURDAY LOOK GOOD ESPECIALLY OVER THE EASTERN
CWA AS ANOTHER SHORTWAVE LOOKS TO BE MOVING THROUGH.

IN THE EXTENDED...GFS AND ECMWF HAVE A DEEP TROUGH OVER THE EASTERN
HALF OF N.A. WITH A RIDGE IN THE WESTERN HALF 12Z SUN. PATTERN DOES
NOT CHANGE UNTIL TUE WHEN THE RIDGE MOVES INTO THE ROCKIES AND THE
TROUGH OVER THE ERN U.S. STARTS TO HEAD EAST AND DE-AMPLIFY A BIT.
COLDER THAN NORMAL TEMPERATURES WILL BEGIN THE PERIOD WITH A SLOW
WARM-UP THIS PERIOD. WITH TROUGHING IN THE AREA THROUGH
MONDAY...DIURNAL SHOWERS ARE DEFINITELY POSSIBLE. A SHORTWAVE
AFFECTS THE AREA FOR WED AND WILL HAVE SLIGHT CHANCE TO LOW CHANCE
POPS IN. TEMPERATURES WARM BACK TO NEAR NORMAL ON TUE AND WED. WILL
CONTINUE DRY FOR MONDAY NIGHT AND TUESDAY.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 117 AM EDT THU AUG 16 2012

EXPECT VFR CONDITIONS AT TAF ISSUANCE AT ALL 3 TAF SITES...BUT THE
APRCH OF A COLD FNT EARLY THIS MRNG WL BRING THE THREAT OF SHRA AND
PERHAPS A TS. INCLUDED AN EXPLICIT MENTION OF TS ONLY AT IWD WHERE
LATEST ANALYSIS SHOWS SOMEWHAT GREATER INSTABILITY. FOLLOWING THE
FROPA...A WSHFT TO THE WNW WL ADVECT COOLER AND MOISTER LLVL AIR
INTO THE AREA...RESULTING IN SOME LO CLDS/MVFR CONDITIONS AND
STRENGTHENING WINDS. THE BEST CHC FOR IFR CONDITIONS AND STRONGER
WINDS WL BE AT THE MORE EXPOSED CMX SITE WITH A MORE PRONOUNCED
UPSLOPE WIND COMPONENT. EXPECT THESE LO CIGS TO SLOWLY LIFT DURING
THE DAY TO VFR. BUT MVFR CIGS MAY LINGER THRU THIS EVNG AT CMX...
WHERE WIND GUSTS MAY APRCH 35 KTS WITH THE APRCH OF AXIS OF COOLEST
AIR/MORE INSTABILITY.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 559 AM EDT THU AUG 16 2012

AS A COLD FRONT MOVES THROUGH LAKE SUPERIOR THIS MORNING...EXPECT A
SHARP WIND SHIFT TO THE WEST FOLLOWING THIS FRONTAL PASSAGE. THE
ARRIVAL OF MUCH COOLER AIR IN THE WAKE OF THE FRONT OVER THE WARM
WATERS OF LAKE SUPERIOR WILL ALSO RESULT IN ENHANCED MIXING OVER THE
LAKE WITH W-NW WINDS UP TO 30 KTS AND GALES TO 40 KNOTS OVER MOST OF
LAKE SUPERIOR THIS AFTERNOON THROUGH TONIGHT AND HAVE POSTED A GALE
WARNING FOR THIS. EXPECT THE STRONGER NW WINDS TO SLOWLY SUBSIDE ON
FRI THRU THE WEEKEND AS THE PRES GRADIENT WEAKENS WITH BROAD HIGH
PRESSURE SETTLING OVER THE REGION. THERE IS ALSO AN INCREASED RISK
OF RIP CURRENTS IN MARQUETTE AND ALGER COUNTIES THROUGH FRIDAY WITH
STRONG NORTHWEST WINDS AND HIGH WAVES.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
  WIND ADVISORY FROM 1 PM THIS AFTERNOON TO MIDNIGHT EDT TONIGHT
     FOR MIZ001-003.

  WIND ADVISORY FROM 9 PM THIS EVENING TO 8 AM EDT FRIDAY FOR
     MIZ006-007.

LAKE SUPERIOR...
  GALE WARNING FROM 10 PM THIS EVENING TO 11 AM EDT FRIDAY FOR
     LSZ267.

  GALE WARNING FROM 2 PM THIS AFTERNOON TO 10 AM EDT FRIDAY FOR
     LSZ264>266.

  GALE WARNING FROM 1 PM THIS AFTERNOON TO 1 AM EDT FRIDAY FOR
     LSZ263.

LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...VOSS
LONG TERM...07
AVIATION...KC
MARINE...07







AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 118 AM EDT THU AUG 16 2012

.UPDATE...
ISSUED AT 842 PM EDT WED AUG 15 2012

TENDED TO SLOW DOWN EWD PROGRESSION OF SHRA/TS NOW IN MN INTO WRN
UPR MI WITH LLVL SE FLOW TENDING TO MAINTAIN DRY LLVL AIR SHOWN ON
THE 00Z APX RAOB OVER THE CWA. THE 12Z CNDN MODEL APPEARS TO HAVE
THE BEST HANDLE ON THIS SLOWER EWD PROGRESSION. EVEN THOUGH VIGOROUS
DYNAMICS ASSOCIATED WITH POTENT SHRTWV MOVING E THRU THE NRN PLAINS
ARE ACTING ON THIS LINE OF SHRA/TS DURING PEAK HEATING TIME...SVR
STORMS HAVE BEEN FEW AND FAR BTWN IN MN. SINCE MODELS SHOW WEAKER
MUCAPES IN THE 400-800 J/KG RANGE OVER THE CWA TNGT...SVR THREAT
SEEMS LO. DESPITE THE PRESENCE OF THIS LARGER SCALE DRY LLVL
AIR...THE 00Z GRB RAOB SHOWS AN AREA OF HIER MID LVL MSTR WITH KINX
OF 33. RADAR SHOWS SOME ISOLD -SHRA OVER NE WI MOVING TOWARD MNM
COUNTY AND HIER MUCAPE OVER THE SE CWA SHOWN ON THE SPC
MESOANALYSIS. SO INTRODUCED SOME ISOLD SHRA/TS OVER THE SE ZNS THRU
06Z. MAINTAINED THE INCRSG POPS LATER TNGT OVER THE CNTRL ZNS AS THE
CNDN MODEL SHOWS HIER QPF AFT 09Z AS DYNAMICS INTERACT WITH MORE
ABUNDANT MID LVL MSTR SHOWN ON THE GRB RAOB AND WSHFT TO THE SW
AHEAD OF APRCHG COLD FNT MIGHT ALLOW MORE LLVL MSTR TO ARRIVE.
&&

.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 425 PM EDT WED AUG 15 2012

WV IMAGERY AND RUC ANALYSIS INDICATED A POSITIVE TILT MID/UPPER
LEVEL TROUGH FROM NRN MANITOBA INTO ERN MT WITH A DOWNSTREAM RIDGE
FROM THE WRN GREAT LAKES INTO NRN ONTARIO. AT THE SFC...A COLD FRONT
EXTENDED THROUGH THE ERN DAKOTAS FROM LOW PRES OVER SE MANITOBA.
LIGHT SHOWERS OVER WRN WI THAT HAD DEVELOPED WITH WAA/305-310K
ISENTROPIC LIFT HAD DISSIPATED AS THEY MOVED INTO DRIER AIR TO THE
EAST...LEAVING MAINLY JUST BKN MID CLOUDS UPSTREAM OVER NW WI. SCT
SHRA/TSRA HAD ALSO DEVELOPED AHEAD OF THE FRONT OVER NW MN.

TONIGHT AND THURSDAY...EVEN THOUGH THE NAM/RUC SEEM OVERDONE WITH
THE AMOUNT OF WAA PCPN INTO THE AREA LATE THIS AFTERNOON AND
EVENING...COMPARED TO CURRENT TRENDS...CANNOT RULE OUT SOME LIGHT
SHOWERS DEVELOPING OVER THE WEST THIS EVENING WHERE SLIGHT CHANCE
POPS WERE RETAINED. OTHERWISE...MORE WIDESPREAD PCPN SHOULD MOVE
INTO THE CWA...MAINLY AFT 06Z AS THE MODELS HAVE TRENDED TOWARD A
SLOWER ARRIVAL OF GREATEST SHRA/TSRA CHANCES. FAVORABLE DYNAMICS
WITH 700-300 MB QVECTOR CONV AHEAD OF THE MID LEVEL TROUGH AND LOW
LEVEL CONV WITH THE FRONT SHOULD SUPPORT CATEGORICAL POPS LATE
TONIGHT INTO THURSDAY MORNING. THE SHRA/TSRA SHOULD EXIT CNTRL UPPER
MI IN THE MORNING AND THE ERN CWA DURING THE EARLY AFTERNOON. THERE
IS LESS CONFIDENCE WITH POTENTIAL FOR HIGHER PCPN AMOUNTS OR SEVERE
WEATHER AS THE GREATER MOISTURE INFLOW AND INSTABILITY WILL REMAIN
FARTHER SOUTH OVER WI.

STRENGTHENING WIND FIELDS WITH 0-6KM SHEAR VALUES INTO THE 30-35 KT
ARE EXPECTED AS THE SHRA/TSRA ARRIVES BUT MAY LAG THE BEST LOW LEVEL
FORCING. NEVERTHELESS THERE IS LIMITED SVR POTENTIAL WITH MUCAPE
VALUES FCST INTO THE 500-1000 J/KG RANGE. IF STRONGER LINEAR
CONVECTIVE AREAS SURVIVE AS THEY MOVE OUT OF MN AND NW WI...SOME
DAMAGING WIND GUSTS MAY BE POSSIBLE AS THE MAIN HAZARD...PER SPC.

.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 425 PM EDT WED AUG 15 2012

TEMPERATURES THROUGH THE EXTENDED WILL REMAIN BELOW NORMAL WITH A
WARMING TREND BEGINNING LATE IN THE PERIOD.

THURSDAY NIGHT THROUGH FRIDAY NIGHT...THE UPPER LEVEL AND SURFACE
LOW WILL BECOME VERTICALLY STACKED THURSDAY NIGHT INTO FRIDAY AS THE
LOW SHIFTS FROM CENTRAL ONTARIO NORTH AND EASTWARD TO JAMES BAY. AS
THIS HAPPENS THE UPPER LEVEL TROUGH AXIS WILL SWING ACROSS UPPER
MICHIGAN. THE COOLER AIR ALOFT ASSOCIATED WITH THIS TROUGH WILL HELP
TO CREATE CONDITIONS FAVORABLE FOR LAKE EFFECT RAIN SHOWERS ACROSS
MAINLY CENTRAL PORTIONS OF UPPER MICHIGAN. H850 TEMPS ARE PROGGED TO
BE AROUND 4 TO 6C WITH SURFACE TEMPS AROUND 18 TO 19C ACROSS THE
AREA...WHICH SHOULD CREATE A LARGE ENOUGH TEMPERATURE DIFFERENCE TO
CAUSE THE LAKE EFFECT RAIN SHOWERS TO FORM. ALONG WITH THE RAIN
SHOWERS...HIGH WINDS ARE ALSO POSSIBLE OVER THE LAKE THURSDAY
AFTERNOON INTO THURSDAY NIGHT AS 30 TO 35 KNOT WINDS...AS SHOWN BY
THE EC/GFS...MIX DOWN TO THE LAKE SURFACE. AS THE UPPER LEVEL LOW
SHIFTS NORTHEASTWARD AND THE UPPER LEVEL TROUGH AXIS SHIFTS PAST THE
UPPER PENINSULA FRIDAY NIGHT...H850 TEMPS ARE EXPECTED TO
WARM...EFFECTIVELY REDUCING THE LAKE EFFECT RAIN SHOWER CHANCES. A
COOL NIGHT IS IN STORE FOR FRIDAY NIGHT AS WINDS BECOME LIGHT AND
SKIES BECOME MOSTLY CLEAR. TEMPERATURES AREA EXPECTED TO BE IN THE
LOW TO MID 40S ACROSS MAINLY INLAND AREAS...WITH A FEW OF THE USUAL
COOL SPOTS POTENTIALLY FALLING INTO THE UPPER 30S.

SATURDAY THROUGH MONDAY...A WEAK COLD FRONT WILL PUSH SOUTHWARD INTO
THE U.P. SATURDAY AFTERNOON THROUGH SUNDAY. A 500MB SHORTWAVE IS
ALSO PROGGED TO MOVE THROUGH THE AREA SATURDAY NIGHT THROUGH
MONDAY...AS IT ROTATES AROUND THE LOW CENTERED OVER JAMES BAY. THIS
SHOULD PROVIDE ENOUGH FORCING FOR A FEW SHOWERS TO DEVELOP THROUGH
THIS TIME PERIOD...HOWEVER...MOISTURE SHOULD BE FAIRLY LIMITED AS A
SURFACE HIGH PRESSURE SYSTEM WILL REMAIN CENTERED TO THE SOUTH
SOUTHWEST OF THE AREA KEEPING DRIER AIR ADVECTING INTO THE AREA FROM
THE WEST.

MONDAY NIGHT THROUGH WEDNESDAY...AS THE UPPER LEVEL LOW BEGINS TO
DRIFT SLOWLY EASTWARD...A RIDGE BUILDING OVER MUCH OF THE PLAINS
STATES WILL BEGIN TO WEAKEN AS IT TRIES TO BUILD EASTWARD INTO THE
UPPER GREAT LAKES REGION. THIS SHOULD ALLOW TEMPERATURES TO INCREASE
TO NEAR NORMAL LEVELS BY TUESDAY AND INTO THE DAY WEDNESDAY. TUESDAY
NIGHT INTO WEDNESDAY BOTH THE GFS/EC HAVE A SHORTWAVE ROTATING
AROUND THE RIDGE ALONG WITH A SURFACE LOW JUST TO THE WEST OF THE
REGION...BRINGING THE NEXT CHANCE OF SHOWERS TO THE AREA.
HOWEVER...WITH CONSIDERABLE DIFFERENCES IN SURFACE LOW PLACEMENT AND
STRENGTH HAVE DECIDED TO STICK TO A CONSENSUS OF THE MODELS.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 117 AM EDT THU AUG 16 2012

EXPECT VFR CONDITIONS AT TAF ISSUANCE AT ALL 3 TAF SITES...BUT THE
APRCH OF A COLD FNT EARLY THIS MRNG WL BRING THE THREAT OF SHRA AND
PERHAPS A TS. INCLUDED AN EXPLICIT MENTION OF TS ONLY AT IWD WHERE
LATEST ANALYSIS SHOWS SOMEWHAT GREATER INSTABILITY. FOLLOWING THE
FROPA...A WSHFT TO THE WNW WL ADVECT COOLER AND MOISTER LLVL AIR
INTO THE AREA...RESULTING IN SOME LO CLDS/MVFR CONDITIONS AND
STRENGTHENING WINDS. THE BEST CHC FOR IFR CONDITIONS AND STRONGER
WINDS WL BE AT THE MORE EXPOSED CMX SITE WITH A MORE PRONOUNCED
UPSLOPE WIND COMPONENT. EXPECT THESE LO CIGS TO SLOWLY LIFT DURING
THE DAY TO VFR. BUT MVFR CIGS MAY LINGER THRU THIS EVNG AT CMX...
WHERE WIND GUSTS MAY APRCH 35 KTS WITH THE APRCH OF AXIS OF COOLEST
AIR/MORE INSTABILITY.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 425 PM EDT WED AUG 15 2012

AS A COLD FRONT MOVES THROUGH LAKE SUPERIOR...EXPECT A SHARP WIND
SHIFT TO THE W LATE TONIGHT AND THU FOLLOWING THIS FRONTAL PASSAGE.
THE ARRIVAL OF MUCH COOLER AIR IN THE WAKE OF THE FRONT OVER THE
WARM WATERS OF LAKE SUPERIOR WILL ALSO RESULT IN ENHANCED MIXING
OVER THE LAKE WITH W-NW WINDS UP TO 30 KTS AND POSSIBLE GALES TO 35
KNOTS OVER THE N CNTRL PORTION OF THE LAKE...FROM LATE THURSDAY
AFTERNOON THROUGH THURSDAY NIGHT WHERE A GALE WATCH WAS POSTED.
SINCE MODELS HAVE TRENDED STRONGER WITH THE LOW LEVEL WIND FIELDS
THERE IS ALSO THE POTENTIAL FOR THE WATCH TO BE EXPANDED AND OR A
WARNING ISSUED FOR A LARGER AREA OF THE LAKE. EXPECT THE STRONGER NW
WINDS TO SLOWLY SUBSIDE ON FRI THRU THE WEEKEND AS THE PRES GRADIENT
WEAKENS WITH BROAD HIGH PRESSURE SETTLING OVER THE REGION.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
  GALE WATCH FROM THIS AFTERNOON THROUGH LATE TONIGHT FOR LSZ264-
     266.

LAKE MICHIGAN...
NONE.
&&

$$

UPDATE...KC
SHORT TERM...JLB
LONG TERM...KEC
AVIATION...KC
MARINE...JLB







AREA FORECAST DISCUSSION

NWS DULUTH MN

 1224 PM CDT THU AUG 16 2012

.AVIATION...

MVFR CIGS AND GUSTY NW WINDS ARE EXPECTED THROUGH THE AFTERNOON
ACROSS NE MINNESOTA AND NW WISCONSIN. THE WINDS AROUND 15 KNOTS WILL
GUST TO 20 TO 30 KNOTS AT TIMES. THERE SHOULD BE GRADUAL LIFTING AND
BREAKING UP OF THE CLOUD COVER THIS AFTERNOON. SOME TERMINALS MAY
RETURN TO LOW END BKN/OVC VFR CIGS MID TO LATE AFTERNOON...BUT
OTHERWISE VFR CONDITIONS SHOULD RETURN EARLY TO MID EVENING. THE NW
WINDS WILL RELAX THIS EVENING AND REMAIN LIGHT OVERNIGHT. THERE MAY
BE SOME GUSTS AROUND 15 KNOTS LATE TOMORROW MORNING WHEN THE NW
WINDS REGAIN SOME STRENGTH.

&&

.PREV DISCUSSION... /ISSUED 1002 AM CDT THU AUG 16 2012/

UPDATE...
EXPANDED COVERAGE OF ISOLATED RAIN SHOWERS THIS MORNING AND EARLY
AFTERNOON FURTHER TO THE SOUTH...AND INCREASED TEMPS 1-2 DEG TO
MATCH WITH CURRENT OBSERVATIONS. OTHERWISE...FORECAST LOOKS ON
TRACK.

PREV DISCUSSION... /ISSUED 634 AM CDT THU AUG 16 2012/

AVIATION...08/16/12Z ISSUANCE...
MVFR OR HIGH-END IFR IN CLOUDS IMPROVING TO MID-RANGE MVFR ABOUT
NOON AND TO VFR CLEAR EARLY THIS EVENING THROUGH TONIGHT.

PREV DISCUSSION... /ISSUED 344 AM CDT THU AUG 16 2012/

SHORT TERM...MSAS SHOWS SFC FRNTL BDRY HAS PUSHED INTO ERN WISC
ZONES EARLY THIS MORNING. PRESSURE IS RISING RAPIDLY BEHIND FRONT
AND GUSTY W/NW WINDS ARE INCREASING. A LARGE CANOPY OF POST
FRONTAL LOW CLOUDS IS OCCURRING WITHIN A DEEP MOIST CIRCULATION
GENERATED BY MID LVL TROF STRETCHING FROM ONTARIO SOUTH TO NRN
IOWA. LATEST WV IMAGERY AND RAP ANALYSIS SHOWS A MID LVL SHORTWAVE
TROF MOVING TOWARDS NWRN MN. BEHIND THIS FEATURE...A SECONDARY
FRONTAL SYSTEM IS INDICATED BY THE 925H THETAE FIELD.

TODAY...SECONDARY SHORTWAVE WILL SWEEP SE QUICKLY THIS MORNING AND
EXIT THE NORTH SHORE OF LAKE SUPERIOR BY MIDDAY. SUFFICIENT MSTR
RESIDES WITHIN THE CYCLONIC FLOW TODAY SO SHOWERS WILL BE OCCURRING
ACROSS THE NRN MN ZONES. A BIT CHALLENGING TO PREDICT WHERE THE
PRECIP/NO PRECIP ZONE WILL LIE EXACTLY. CLOUDS WILL BE PREVALENT
IN MOST AREAS THROUGH 18Z...BEFORE A MORE SERIOUS CLEARING TREND
DEVELOPS. LATEST NAM12 FCST AND BUFKIT PROFILES INDICATE 25-35MPH
GUSTS ARE POSSIBLE TODAY. ALONG THE NORTH SHORE THIS AFTN LOCALIZED
HIGHER WINDS ARE POSSIBLE AS AIR DESCENDS FROM HIGHER ELEVATION OF
COOK/LAKE COUNTY DOWN TO LAKE FRONT. MOST SIGNIFICANT COLD
ADVECTION IN BDRY LYR IS FOCUSED OVER ARROWHEAD SO MAX TEMPS MAY
BE SIGNIFICANTLY LOWER THAN SWRN CWA WHERE MORE NEUTRAL ADVECTION
OCCURS BY AFTN.

TONIGHT/TOMORROW...NO MAJOR CHANGES MADE TO EXISTING FCST EXCEPT
TO LOWER POPS FRIDAY OVER ARROWHEAD. SFC HIGH WILL SLOWLY APPROACH
THE CWA AS DEEP UPPER TROF CRAWLS EAST. INHERITED MIN TEMPS LOOK A
BIT ON THE LOW SIDE CONSIDERING SOME AMOUNT OF MIXING IS IMPLIED
BY THE FCST SFC PRESS GRADIENT AND POTENTIAL FOR FEW MORE CLOUDS
IN NW FLOW ALOFT. CURRENT FCST VALUES ARE ON LOW EDGE OF LATEST
SREF 2M TEMP PLUMES SO WE MAY NEED SOME TWEAK UPWARDS IN LATER
FORECASTS. A MID LVL SHORTWAVE TROF WILL APPROACH THE BORDERLAND
AND THE ARROWHEAD LATE FRIDAY. MDL CONSENSUS IS THAT ANY PRECIP
WILL BE SLOW TO ARRIVE.

LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
SHORT WAVES ROTATING AROUND THE JAMES BAY UPPER TROUGH WILL PROVOKE
A FEW MOSTLY AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS ACROSS
THE AREA THROUGH THE COMING WEEKEND.  A MORE ZONAL FLOW WILL DRY OUR
AREA OUT MONDAY AND TUESDAY.  AFTERNOON TEMPERATURES AROUND 70 THIS
WEEKEND WILL WARM TO THE MID OR UPPER 70S MONDAY AND GET INTO THE
80S TUESDAY.  A COLD FRONT FROM CENTRAL CANADA AND A DIGGING TROUGH
ALOFT WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY AND THURSDAY.

&&

.POINT TEMPS/POPS...
DLH  45  68  49  70 /   0  10  10  20
INL  43  71  44  69 /  10  20  10  10
BRD  45  70  51  73 /   0   0  10  20
HYR  43  68  44  73 /   0  10  10  20
ASX  47  71  47  71 /  10  10  10  20

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
     140>148.

&&

$$

AVIATION...GROCHOCINSKI






AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 1002 AM CDT THU AUG 16 2012

.UPDATE...
EXPANDED COVERAGE OF ISOLATED RAIN SHOWERS THIS MORNING AND EARLY
AFTERNOON FURTHER TO THE SOUTH...AND INCREASED TEMPS 1-2 DEG TO
MATCH WITH CURRENT OBSERVATIONS. OTHERWISE...FORECAST LOOKS ON
TRACK.

&&

.PREV DISCUSSION... /ISSUED 634 AM CDT THU AUG 16 2012/

AVIATION...08/16/12Z ISSUANCE...
MVFR OR HIGH-END IFR IN CLOUDS IMPROVING TO MID-RANGE MVFR ABOUT
NOON AND TO VFR CLEAR EARLY THIS EVENING THROUGH TONIGHT.

PREV DISCUSSION... /ISSUED 344 AM CDT THU AUG 16 2012/

SHORT TERM...MSAS SHOWS SFC FRNTL BDRY HAS PUSHED INTO ERN WISC
ZONES EARLY THIS MORNING. PRESSURE IS RISING RAPIDLY BEHIND FRONT
AND GUSTY W/NW WINDS ARE INCREASING. A LARGE CANOPY OF POST
FRONTAL LOW CLOUDS IS OCCURRING WITHIN A DEEP MOIST CIRCULATION
GENERATED BY MID LVL TROF STRETCHING FROM ONTARIO SOUTH TO NRN
IOWA. LATEST WV IMAGERY AND RAP ANALYSIS SHOWS A MID LVL SHORTWAVE
TROF MOVING TOWARDS NWRN MN. BEHIND THIS FEATURE...A SECONDARY
FRONTAL SYSTEM IS INDICATED BY THE 925H THETAE FIELD.

TODAY...SECONDARY SHORTWAVE WILL SWEEP SE QUICKLY THIS MORNING AND
EXIT THE NORTH SHORE OF LAKE SUPERIOR BY MIDDAY. SUFFICIENT MSTR
RESIDES WITHIN THE CYCLONIC FLOW TODAY SO SHOWERS WILL BE OCCURRING
ACROSS THE NRN MN ZONES. A BIT CHALLENGING TO PREDICT WHERE THE
PRECIP/NO PRECIP ZONE WILL LIE EXACTLY. CLOUDS WILL BE PREVALENT
IN MOST AREAS THROUGH 18Z...BEFORE A MORE SERIOUS CLEARING TREND
DEVELOPS. LATEST NAM12 FCST AND BUFKIT PROFILES INDICATE 25-35MPH
GUSTS ARE POSSIBLE TODAY. ALONG THE NORTH SHORE THIS AFTN LOCALIZED
HIGHER WINDS ARE POSSIBLE AS AIR DESCENDS FROM HIGHER ELEVATION OF
COOK/LAKE COUNTY DOWN TO LAKE FRONT. MOST SIGNIFICANT COLD
ADVECTION IN BDRY LYR IS FOCUSED OVER ARROWHEAD SO MAX TEMPS MAY
BE SIGNIFICANTLY LOWER THAN SWRN CWA WHERE MORE NEUTRAL ADVECTION
OCCURS BY AFTN.

TONIGHT/TOMORROW...NO MAJOR CHANGES MADE TO EXISTING FCST EXCEPT
TO LOWER POPS FRIDAY OVER ARROWHEAD. SFC HIGH WILL SLOWLY APPROACH
THE CWA AS DEEP UPPER TROF CRAWLS EAST. INHERITED MIN TEMPS LOOK A
BIT ON THE LOW SIDE CONSIDERING SOME AMOUNT OF MIXING IS IMPLIED
BY THE FCST SFC PRESS GRADIENT AND POTENTIAL FOR FEW MORE CLOUDS
IN NW FLOW ALOFT. CURRENT FCST VALUES ARE ON LOW EDGE OF LATEST
SREF 2M TEMP PLUMES SO WE MAY NEED SOME TWEAK UPWARDS IN LATER
FORECASTS. A MID LVL SHORTWAVE TROF WILL APPROACH THE BORDERLAND
AND THE ARROWHEAD LATE FRIDAY. MDL CONSENSUS IS THAT ANY PRECIP
WILL BE SLOW TO ARRIVE.

LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
SHORT WAVES ROTATING AROUND THE JAMES BAY UPPER TROUGH WILL PROVOKE
A FEW MOSTLY AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS ACROSS
THE AREA THROUGH THE COMING WEEKEND.  A MORE ZONAL FLOW WILL DRY OUR
AREA OUT MONDAY AND TUESDAY.  AFTERNOON TEMPERATURES AROUND 70 THIS
WEEKEND WILL WARM TO THE MID OR UPPER 70S MONDAY AND GET INTO THE
80S TUESDAY.  A COLD FRONT FROM CENTRAL CANADA AND A DIGGING TROUGH
ALOFT WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY AND THURSDAY.

&&

.POINT TEMPS/POPS...
DLH  65  45  68  49 /  20   0  10  10
INL  61  43  71  44 /  30  10  20  10
BRD  67  45  70  51 /  20   0   0  10
HYR  66  43  68  44 /  20   0  10  10
ASX  69  47  71  47 /  20  10  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
     144>148.

     SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ140>143.

&&

$$

SHORT TERM...TENTINGER






AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 634 AM CDT THU AUG 16 2012

.AVIATION...08/16/12Z ISSUANCE...
MVFR OR HIGH-END IFR IN CLOUDS IMPROVING TO MID-RANGE MVFR ABOUT
NOON AND TO VFR CLEAR EARLY THIS EVENING THROUGH TONIGHT.

&&

.PREV DISCUSSION... /ISSUED 344 AM CDT THU AUG 16 2012/

SHORT TERM...MSAS SHOWS SFC FRNTL BDRY HAS PUSHED INTO ERN WISC
ZONES EARLY THIS MORNING. PRESSURE IS RISING RAPIDLY BEHIND FRONT
AND GUSTY W/NW WINDS ARE INCREASING. A LARGE CANOPY OF POST
FRONTAL LOW CLOUDS IS OCCURRING WITHIN A DEEP MOIST CIRCULATION
GENERATED BY MID LVL TROF STRETCHING FROM ONTARIO SOUTH TO NRN
IOWA. LATEST WV IMAGERY AND RAP ANALYSIS SHOWS A MID LVL SHORTWAVE
TROF MOVING TOWARDS NWRN MN. BEHIND THIS FEATURE...A SECONDARY
FRONTAL SYSTEM IS INDICATED BY THE 925H THETAE FIELD.

TODAY...SECONDARY SHORTWAVE WILL SWEEP SE QUICKLY THIS MORNING AND
EXIT THE NORTH SHORE OF LAKE SUPERIOR BY MIDDAY. SUFFICIENT MSTR
RESIDES WITHIN THE CYCLONIC FLOW TODAY SO SHOWERS WILL BE OCCURRING
ACROSS THE NRN MN ZONES. A BIT CHALLENGING TO PREDICT WHERE THE
PRECIP/NO PRECIP ZONE WILL LIE EXACTLY. CLOUDS WILL BE PREVALENT
IN MOST AREAS THROUGH 18Z...BEFORE A MORE SERIOUS CLEARING TREND
DEVELOPS. LATEST NAM12 FCST AND BUFKIT PROFILES INDICATE 25-35MPH
GUSTS ARE POSSIBLE TODAY. ALONG THE NORTH SHORE THIS AFTN LOCALIZED
HIGHER WINDS ARE POSSIBLE AS AIR DESCENDS FROM HIGHER ELEVATION OF
COOK/LAKE COUNTY DOWN TO LAKE FRONT. MOST SIGNIFICANT COLD
ADVECTION IN BDRY LYR IS FOCUSED OVER ARROWHEAD SO MAX TEMPS MAY
BE SIGNIFICANTLY LOWER THAN SWRN CWA WHERE MORE NEUTRAL ADVECTION
OCCURS BY AFTN.

TONIGHT/TOMORROW...NO MAJOR CHANGES MADE TO EXISTING FCST EXCEPT
TO LOWER POPS FRIDAY OVER ARROWHEAD. SFC HIGH WILL SLOWLY APPROACH
THE CWA AS DEEP UPPER TROF CRAWLS EAST. INHERITED MIN TEMPS LOOK A
BIT ON THE LOW SIDE CONSIDERING SOME AMOUNT OF MIXING IS IMPLIED
BY THE FCST SFC PRESS GRADIENT AND POTENTIAL FOR FEW MORE CLOUDS
IN NW FLOW ALOFT. CURRENT FCST VALUES ARE ON LOW EDGE OF LATEST
SREF 2M TEMP PLUMES SO WE MAY NEED SOME TWEAK UPWARDS IN LATER
FORECASTS. A MID LVL SHORTWAVE TROF WILL APPROACH THE BORDERLAND
AND THE ARROWHEAD LATE FRIDAY. MDL CONSENSUS IS THAT ANY PRECIP
WILL BE SLOW TO ARRIVE.

LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
SHORT WAVES ROTATING AROUND THE JAMES BAY UPPER TROUGH WILL PROVOKE
A FEW MOSTLY AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS ACROSS
THE AREA THROUGH THE COMING WEEKEND.  A MORE ZONAL FLOW WILL DRY OUR
AREA OUT MONDAY AND TUESDAY.  AFTERNOON TEMPERATURES AROUND 70 THIS
WEEKEND WILL WARM TO THE MID OR UPPER 70S MONDAY AND GET INTO THE
80S TUESDAY.  A COLD FRONT FROM CENTRAL CANADA AND A DIGGING TROUGH
ALOFT WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY AND THURSDAY.

&&

.POINT TEMPS/POPS...
DLH  64  45  68  49 /  10   0  10  10
INL  62  41  71  44 /  30  10  20  10
BRD  68  45  70  51 /  10   0   0  10
HYR  68  44  68  44 /  20   0  10  10
ASX  68  47  71  47 /  20  10  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
     144>148.

&&

$$

SHORT TERM...CANNON
LONG TERM....EOM
AVIATION...EOM






AREA FORECAST DISCUSSION

NWS DULUTH MN

 344 AM CDT THU AUG 16 2012

.SHORT TERM...MSAS SHOWS SFC FRNTL BDRY HAS PUSHED INTO ERN WISC
ZONES EARLY THIS MORNING. PRESSURE IS RISING RAPIDLY BEHIND FRONT
AND GUSTY W/NW WINDS ARE INCREASING. A LARGE CANOPY OF POST
FRONTAL LOW CLOUDS IS OCCURRING WITHIN A DEEP MOIST CIRCULATION
GENERATED BY MID LVL TROF STRETCHING FROM ONTARIO SOUTH TO NRN
IOWA. LATEST WV IMAGERY AND RAP ANALYSIS SHOWS A MID LVL SHORTWAVE
TROF MOVING TOWARDS NWRN MN. BEHIND THIS FEATURE...A SECONDARY
FRONTAL SYSTEM IS INDICATED BY THE 925H THETAE FIELD.

TODAY...SECONDARY SHORTWAVE WILL SWEEP SE QUICKLY THIS MORNING AND
EXIT THE NORTH SHORE OF LAKE SUPERIOR BY MIDDAY. SUFFICIENT MSTR
RESIDES WITHIN THE CYCLONIC FLOW TODAY SO SHOWERS WILL BE OCCURRING
ACROSS THE NRN MN ZONES. A BIT CHALLENGING TO PREDICT WHERE THE
PRECIP/NO PRECIP ZONE WILL LIE EXACTLY. CLOUDS WILL BE PREVALENT
IN MOST AREAS THROUGH 18Z...BEFORE A MORE SERIOUS CLEARING TREND
DEVELOPS. LATEST NAM12 FCST AND BUFKIT PROFILES INDICATE 25-35MPH
GUSTS ARE POSSIBLE TODAY. ALONG THE NORTH SHORE THIS AFTN LOCALIZED
HIGHER WINDS ARE POSSIBLE AS AIR DESCENDS FROM HIGHER ELEVATION OF
COOK/LAKE COUNTY DOWN TO LAKE FRONT. MOST SIGNIFICANT COLD
ADVECTION IN BDRY LYR IS FOCUSED OVER ARROWHEAD SO MAX TEMPS MAY
BE SIGNIFICANTLY LOWER THAN SWRN CWA WHERE MORE NEUTRAL ADVECTION
OCCURS BY AFTN.

TONIGHT/TOMORROW...NO MAJOR CHANGES MADE TO EXISTING FCST EXCEPT
TO LOWER POPS FRIDAY OVER ARROWHEAD. SFC HIGH WILL SLOWLY APPROACH
THE CWA AS DEEP UPPER TROF CRAWLS EAST. INHERITED MIN TEMPS LOOK A
BIT ON THE LOW SIDE CONSIDERING SOME AMOUNT OF MIXING IS IMPLIED
BY THE FCST SFC PRESS GRADIENT AND POTENTIAL FOR FEW MORE CLOUDS
IN NW FLOW ALOFT. CURRENT FCST VALUES ARE ON LOW EDGE OF LATEST
SREF 2M TEMP PLUMES SO WE MAY NEED SOME TWEAK UPWARDS IN LATER
FORECASTS. A MID LVL SHORTWAVE TROF WILL APPROACH THE BORDERLAND
AND THE ARROWHEAD LATE FRIDAY. MDL CONSENSUS IS THAT ANY PRECIP
WILL BE SLOW TO ARRIVE.

.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY...
SHORT WAVES ROTATING AROUND THE JAMES BAY UPPER TROUGH WILL PROVOKE
A FEW MOSTLY AFTERNOON AND EVENING SHOWERS OR THUNDERSTORMS ACROSS
THE AREA THROUGH THE COMING WEEKEND.  A MORE ZONAL FLOW WILL DRY OUR
AREA OUT MONDAY AND TUESDAY.  AFTERNOON TEMPERATURES AROUND 70 THIS
WEEKEND WILL WARM TO THE MID OR UPPER 70S MONDAY AND GET INTO THE
80S TUESDAY.  A COLD FRONT FROM CENTRAL CANADA AND A DIGGING TROUGH
ALOFT WILL BRING SCATTERED THUNDERSTORMS WEDNESDAY AND THURSDAY.

.AVIATION...08/16/06Z ISSUANCE...
FRONTAL BOUNDARY IS SLOWLY PROGRESSING THROUGH THE FA WITH SHOWERS
AND STORMS AHEAD OF THE FRONT. A MIX OF HIGH END MVFR/LOW END VFR
CIGS/VSBYS IN THE VCNTY OF THE STORMS. BEHIND THE FRONT...MVFR CIGS
WITH AREAS OF -DZ UNTIL AROUND 18Z WHEN DRIER AIR BEGINS TO MOVE
INTO THE AREA WITH BUILDING HIGH PRESSURE LEADING TO VFR.



.POINT TEMPS/POPS...
DLH  64  45  68  49 /  10   0  10  10
INL  62  41  71  44 /  30  10  20  10
BRD  68  45  70  51 /  10   0   0  10
HYR  68  44  68  44 /  20   0  10  10
ASX  68  47  71  47 /  20  10  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 PM CDT THIS EVENING FOR LSZ121-
     144>148.

&&

$$

SHORT TERM...CANNON
LONG TERM....EOM






AREA FORECAST DISCUSSION...UPDATED

NWS DULUTH MN

 1210 AM CDT THU AUG 16 2012

.AVIATION...08/16/06Z ISSUANCE...
FRONTAL BOUNDARY IS SLOWLY PROGRESSING THROUGH THE FA WITH SHOWERS
AND STORMS AHEAD OF THE FRONT. A MIX OF HIGH END MVFR/LOW END VFR
CIGS/VSBYS IN THE VCNTY OF THE STORMS. BEHIND THE FRONT...MVFR CIGS
WITH AREAS OF -DZ UNTIL AROUND 18Z WHEN DRIER AIR BEGINS TO MOVE
INTO THE AREA WITH BUILDING HIGH PRESSURE LEADING TO VFR.

&&

.PREV DISCUSSION... /ISSUED 832 PM CDT WED AUG 15 2012/

UPDATE...THUNDERSTORMS HAVE WEAKENED CONSIDERABLY AS COLD FRONT
MOVES THROUGH A LARGELY STABLE ATMOPSHERE. STILL EXPECT STORMS
TO PERCOLATE THROUGH THE EVENING AHEAD OF THE FRONT UNTIL IT CLEARS
THE FA ROUGHLY AROUND 06Z. SAID STORMS ARE ONLY PRODUCING
BENEFICIAL RAINS AND OCCASIONAL LIGHTNING. NO GUSTY WINDS OR HAIL
HAVE BEEN REPORTED WITH THESE STORMS. HAVE UPDATED TO REMOVE
SEVERE WORDING.

PREV DISCUSSION... /ISSUED 307 PM CDT WED AUG 15 2012/

SHORT TERM...[NOW - THURSDAY NIGHT]

AT 20Z...THERE WAS A POTENT SHORTWAVE IN EASTERN MONTANA AND
WESTERN NORTH DAKOTA APPROACHING THE NORTHERN PLAINS...AND AN
ASSOCIATED MID/UPPER LEVEL TROUGH EXTENDING INTO CENTRAL CANADA.
AN ASSOCIATED SURFACE LOW WAS IN SOUTHEASTERN MANITOBA. A 70 TO 80
KNOT JET WAS ROUNDING THE BASE OF THE MID/UPPER LEVEL TROUGH. A
STRONG COLD FRONT IN ASSOCIATION WITH THE SURFACE LOW STRETCHED
FROM SOUTHEASTERN MANITOBA...THROUGH NORTHWESTERN MINNESOTA...AND
THROUGH EASTERN SOUTH DAKOTA. THE FA HAD SLIGHTLY GUSTY SOUTHERLY
WINDS. TEMPERATURES WERE IN THE MID TO UPPER 70S. DEW POINT
TEMPERATURES WERE STILL IN THE 50S ACROSS MUCH OF THE EASTERN
FA...BUT THEY WERE CLIMBING INTO THE LOW TO MID 60S ACROSS THE
WESTERN FA WITH THE INFLUX OF MOISTURE AHEAD OF THE APPROACHING
COLD FRONT. THERE WERE SHOWERS AND SOME STORMS STRETCHING FROM
SOUTHWESTERN ONTARIO...THROUGH NORTHWESTERN MINNESOTA...AND INTO
EAST CENTRAL NORTH DAKOTA.

THROUGH THIS EVENING...THE COLD FRONT IN WESTERN MINNESOTA IS
EXPECTED TO SWEEP ACROSS THE NORTHLAND LATE THIS AFTERNOON AND
THIS EVENING...AND ITS PASSAGE WILL LIKELY MEAN SHOWERS AND
THUNDERSTORMS FOR MUCH OF THE FA. THE MODELS CONTINUE TO BE IN
REASONABLE AGREEMENT WITH TIMING AND PCPN. THE INFLUX OF WARM
SOUTHERLY FLOW AHEAD OF THE FRONT...COUPLED WITH THE EXPECTED
SHEAR AND CAPE...COULD RESULT IN SOME SEVERE THUNDERSTORMS.
CONTINUE TO THINK THAT MORE DISCREET SHOWERS AND STORMS IN WESTERN
MINNESOTA THIS AFTERNOON WILL BEGIN TO MOVE INTO NORTHEASTERN
MINNESOTA LATE THIS AFTERNOON AND TAKE ON A MORE LINEAR STRUCTURE.
THIS IS BACKED UP BY RECENT RUNS OF THE WRF AND HRRR MODELS. THIS
WOULD SUGGEST THAT DAMAGING WINDS ARE THE GREATEST THREAT FOR THE
STORMS TONIGHT...AND THAT IS IN AGREEMENT WITH THE SLIGHT RISK OF
SEVERE WEATHER CURRENTLY OUT FROM THE STORM PREDICTION CENTER AND
ITS EMPHASIS ON DAMAGING WINDS. LARGE HAIL AND BRIEF DOWNPOURS OF
RAIN ARE BOTH CERTAINLY POSSIBLE TOO. MIXED LAYER CAPE VALUES OF
1000 TO 2000 J/KG...DEEP LAYER SHEAR OF 30 TO 50 KNOTS...AND
PRECIPITABLE WATER VALUES OF AROUND 1.5 INCHES ARE EXPECTED THIS
AFTERNOON WHEN THE COLD FRONT MOVES INTO THE WESTERN FA. SINCE
THIS COLD FRONT WILL BE MOVING FAIRLY QUICKLY...HEAVY RAIN IS NOT
TOO MUCH OF AN ISSUE DUE TO LACK OF THUNDERSTORMS RESIDENCE TIME
OR TRAINING. HOWEVER...THERE COULD CERTAINLY BE BRIEF DOWNPOURS
WITH THE RAIN. MUCH OF THE FA HAS BEEN GIVEN ABOUT A QUARTER TO
HALF INCH OF RAIN FOR THE FORECAST THROUGH THIS EVENING.

LATE TONIGHT...MUCH COOLER AIR WILL SWOOP INTO THE NORTHLAND LATE
TONIGHT IN THE WAKE OF THE FRONT. ANY REMAINING PCPN SHOULD
TRANSITION TO SHOWERS...BUT THERE MAY BE SOME LINGERING THUNDER
ACROSS THE FAR EASTERN FA.

THURSDAY...IT LOOKS LIKE A SOMEWHAT DREARY SUMMER DAY ACROSS THE
NORTHLAND. PARTLY TO MOSTLY CLOUDY SKIES...GUSTY NORTHWEST
WINDS...AND MUCH COOLER TEMPERATURES ARE EXPECTED IN THE WAKE OF
THE FRONT. MODEL SOUNDINGS SUGGEST WIND GUSTS OF 20 TO 30 MPH AT
TIMES. SHOWERS ARE POSSIBLE ACROSS NORTHERN MINNESOTA. THERE MAY
BE SOME LATE DAY SUNSHINE ACROSS THE WESTERN FA.

THURSDAY NIGHT...THE CLOUDS SHOULD GRADUALLY CLEAR AND THE WINDS
RELAX AS HIGH PRESSURE MOVES INTO THE NORTH CENTRAL US.

LONG TERM...[FRIDAY - TUESDAY]

PATTERN CHANGE TO A STRONGER UPPER LEVEL TROF ANCHORED OVER THE
CENTRAL GREAT LAKES THIS WEEKEND AND EARLY NEXT WEEK WILL LEAVE
THE DULUTH CWA UNDERNEATH COOL NW FLOW ALOFT AND WHAT WILL
PROBABLY FEEL LIKE EARLY FALL WEATHER AT TIMES. AS IS COMMON IN
PREVAILING NW FLOW ALOFT..A SERIES OF WEAK BUT AMPLIFYING
DISTURBANCES WILL DIVE SOUTHEASTWARD ACROSS OUR AREA INTO THE MAIN
TROF AXIS DURING THE SAT-MON TIME FRAME. RELATIVELY COOL TEMPS
ALOFT AND STEEP LOW-MID LEVEL LAPSE RATES WITH ANY DAYTIME SUN
SHOULD RESULT IN ISOLATED/SCATTERED SHOWERS AND PERHAPS A FEW
T-STORMS EACH DAY FRIDAY THRU SUNDAY. MODELS TYPICALLY HAVE A HARD
TIME RESOLVING INDIVIDUAL DISTURBANCES IN THIS FLOW REGIME BEYOND
48-60 HOURS..AND THIS SEEMS TO BE THE CASE THRU MONDAY AS THE WAVE
THAT SEEMS BEST RESOLVED RIGHT NOW TIMING/PLACEMENT WISE IS ON
FRIDAY.

EARLY NEXT WEEK LOOKS FAIRLY TRANQUIL WITH A SLOW WARMING TREND OF
A FEW DEGREES EACH DAY AS GREAT LAKES TROF SLOWLY DE-AMPLIFIES
AND FLOW ALOFT BECOMES MORE WESTERLY. THIS SHOULD EVENTUALLY ALLOW
MOISTURE TO SLOWLY INCREASE BY THE END OF THE 7 DAY FORECAST
PERIOD..WITH AT LEAST SMALL CHANCES FOR SHOWERS/TSTMS RETURNING
FROM WED/THUR.

&&

.POINT TEMPS/POPS...
DLH  45  69  51  70 /   0  30  20  20
INL  41  72  43  70 /  10  30  20  10
BRD  45  71  51  73 /   0  10  10  20
HYR  44  69  43  72 /   0  20  20  20
ASX  47  72  48  71 /  10  30  20  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&

$$

SHORT TERM...CANNON
LONG TERM....EOM
AVIATION...EOM






AREA FORECAST DISCUSSION...UPDATED AVIATION

NWS ST LOUIS MO

 1210 PM CDT THU AUG 16 2012

.UPDATE...
ISSUED AT 1051 AM CDT THU AUG 16 2012

COLD FRONT HAS NOW MOVED TO NEAR A EOK-IRK-SZL AT 15Z. MAIN CLUSTER
OF THUNDERSTORMS ARE STAYING NORTH AND NORTHEAST OF THE CWA AHEAD
OF A VORT MAX OVER FAR EASTERN IOWA. STILL EXPECT SOME DEVELOPMENT
FARTHER SOUTH THE NEXT FEW HOURS AS THE RAP IS SHOWING DECENT SURFACE-
850MB MOISTURE CONVERGENCE DEVELOPING ALONG THE FRONT BETWEEN 18-21Z.
LATEST SPC OBJECTIVE ANALYSIS IS SHOWING MIXED LAYER CAPES OF 2000-2500
J/KG SOUTH OF THE FRONT WITH RAP FORECAST SOUNDINGS SHOWING THE CINH
ERODING BY EARLY AFTERNOON. PREDOMINANT CONVECTIVE MODE STILL LOOKS
LIKE IT WILL BE FROM MULTI-CELL STORMS AS BEST DEEP LAYER SHEAR
REMAINS NORTH OF THE AREA.

HAVE TRIMMED BACK LIKELY POPS FROM CENTRAL MISSOURI INTO WEST
CENTRAL ILLINOIS WHERE THE FRONT HAS ALREADY MOVED SOUTH. FARTHER
SOUTH...HAVE MAINTAINED LIKELY POPS AHEAD OF THE FRONT GIVEN THAT
LOW LEVEL CONVERGENCE WILL BE PERSISTENT WITH THE ERODING CINH.
WILL KEEP CHANCE POPS OVER NORTHEAST MISSOURI AND WEST CENTRAL
ILLINOIS THIS AFTERNOON WHICH WILL HAVE WEAK ASCENT FROM THE TAIL
END OF THE MAIN SHORTWAVE TROUGH MOVING EAST THROUGH THE UPPER
MIDWEST.

BRITT

&&

.SHORT TERM...
ISSUED AT 248 AM CDT THU AUG 16 2012
(TODAY AND TONIGHT)

AS OF THIS WRITING...THE CDFNT THAT IS EXPECTED TO BRING TSRA TO
THE REGION TODAY IS JUST NOW REACHING FAR NWRN TIP OF MO. THE
FORECAST WILL LIKELY TAKE ON A NUMBER OF ITERATIONS TODAY AS A
NUMBER OF QUESTIONS REMAIN WITH MDLS OFFERING A WIDE VARIETY OF
SOLNS.

STRONG WAA EVIDENT IN SATELLITE IMAGERY THIS MORNING WITH ACCAS
AND ISOD SHRA ALREADY DEVELOPED IN CNTL IL STRETCHING WWD INTO W
CNTL IL. WHILE THIS IS DEPICTED IN THE NAM...THE NAM OBVIOUSLY
DOES NOT HAVE ENUF OF A CAP IN PLACE GIVEN FORECAST SOUNDINGS AND
PRECIP OUTPUT. THIS STRONG WAA SHUD ALSO HELP TO PUT A CAP IN
PLACE AHEAD OF THE CDFNT PREVENTING ANY CONVECTION UNTIL EITHER
LATE THIS MORNING OR INTO THE AFTERNOON.

IN GENERAL...BELIEVE TSRA WILL BE LIMITED TO NRN COUNTIES LATE
THIS MORNING AS ONGOING TSRA DIMINISH WITH LOSS OF LLJ. SINCE THE
BEST FORCING AND WEAKEST CAP WILL BE ALONG THE FNT...HAVE TIMED
THE HIGHEST POPS TO BE CO-LOCATED WITH THE FNT. THAT SAID...WITH
DEWPOINTS REACHING INTO THE UPPER 60S...IT SHUD NOT TAKE TOO MUCH
HEATING FOR PARCELS TO BECOME UNSTABLE.

AS FOR THE SVR THREAT...MDLS CONTINUE TO PROG K INDEX VALUES
AROUND 40C. THIS WUD NORMALLY SUGGEST TSRA WILL BE TOO WATER LADEN
TO PRODUCE MUCH IN THE WAY OF SVR WX. HOWEVER...MDL MOISTURE
PROFILE MAY BE OVERDONE. EVEN IF TSRA ARE WATER LADEN...STEEP LOW
LEVEL LAPSE RATES WILL POSE A WIND THREAT ACROSS THE REGION. ANY
OUTFLOW BOUNDARY MAY MODIFY THE ENVIRONMENT AND INCREASE SHEAR
ENUF TO SUPPORT LARGE HAIL LATER IN THE DAY. THIS THREAT SHUD
LINGER INTO AT LEAST THE EARLY EVENING.

THE NAM IS NOW THE ONLY MDL SUGGESTING STRONG FRONTOGENESIS THIS
EVENING PRODUCING TSRA BEHIND THE FNT. WHILE THIS WUD GENERALLY
SUGGEST SHRA...PROG SOUNDINGS HAVE ELEVATED PARCELS UNCAPPED WITH
STRONG FORCING AND HIGH CAPE. IT IS DOUBTFUL HOWEVER THAT ANY SVR
TSRA WILL OCCUR BEHIND THE FNT AS EARLIER ACTIVITY WILL GREATLY
MODIFY THE ATMO AS THE FNT MOVES THRU THE REGION.

AS FOR TEMPS...HAVE TRENDED TWD THE WARM SOLNS...ESP S OF THE FNT.
ALSO TRENDED TWD THE COOLER SOLNS TONIGHT BEHIND THE FNT AS SKIES
CLEAR OUT ACROSS NRN PORTIONS OF THE CWA. OVERALL...THIS RESULTS
IN VERY FEW CHANGES TO THE PREV FORECAST.

TILLY

&&

.LONG TERM...
ISSUED AT 338 AM CDT THU AUG 16 2012
(SATURDAY THROUGH WEDNESDAY)

BEHIND THE CDFNT MENTIONED ABOVE...A LARGE SFC RIDGE WILL SETTLE
INTO THE REGION. HAVE KEPT SLIGHT CHANCE POPS FRI MORNING TO
ACCOUNT FOR ANY LINGERING TSRA LEFT OVER FROM TONIGHT BUT BULK OF
THE ACTIVITY IS EXPECTED TO BE S OF THE CWA.

NW FLOW WILL SETTLE OVER THE REGION WHICH PRESENTS A BIG FORECAST
CHALLENGE. ANY SUBTLE S/W MAY BE ENUF TO GENERATE PRECIP. MDLS
STILL IN GENERALLY GOOD AGREEMENT WITH A S/W DROPPING INTO THE
REGION LATE SAT INTO SUN. HOWEVER...WITH MUCH OF THE MO/IL REGION
LACKING MUCH IN THE WAY OF MOISTURE...IT CURRENTLY APPEARS THIS
S/W WILL NOT GENERATE PRECIP FOR THE CWA.

OTHERWISE...FORECAST REMAINS DRY THRU THE PERIOD WITH BELOW
SEASONAL AVERAGE TEMPS. MDLS IN FAIRLY GOOD AGREEMENT THRU TUES
WITH THE AREA REMAINING IN NW FLOW. BEYOND TUES...THE ECMWF/GEM
SUGGEST A SYSTEM REINFORCING THE UPPER TROF WHILE THE GFS SUGGESTS
THE UPPER RIDGE STARTING TO BUILD BACK INTO THE REGION. DUE TO THE
LARGE DIFFERENCES...HAVE TRENDED TWD A BLEND OF GUIDANCE WHICH
RESULTS NEAR CLIMO. WILL MAKE ADJUSTMENTS AS MDLS COME INTO BETTER
AGREEMENT.

TILLY

&&

.AVIATION...
ISSUED AT 1152 AM CDT THU AUG 16 2012

COLD FRONT IS CURRENTLY NEAR A KUIN-KMBY-KDMO LINE. THE WIND IS
HAS JUST SHIFTED BEHIND FROPA AT KUIN...AND SHOULD ALSO SHIFT
FROM SOUTHWEST TO NORTHWEST WITHIN THE NEXT 1-2 HOURS AT KCOU.
THIS SHIFT WILL LIKELY OCCUR AROUND 21Z AT THE ST. LOUIS METRO TAF
SITES. THUNDERSTORMS ARE STILL EXPECTED TO INCREASE IN COVERAGE
AHEAD OF THE FRONT AS ATMOSPHERE BECOMES MORE UNSTABLE...AND HAVE
EXPANDED THE TIMING OF THE TEMPO GROUP FROM 18-21Z FOR -TSRA. NEW
CELL HAS DEVELOPED TO THE NORTHWEST OF KSTL IN THE LAST FEW
MINUTES. EXPECT MAINLY VFR CONDITIONS THIS AFTERNOON WITH TWO
EXCEPTIONS. ONE BEING MVFR OR POSSIBLY IFR CONDITIONS WITH HEAVER
CORES OF RAIN...THE SECOND WITH LOWER CEILINGS MOVING SOUTH OUT OF
IOWA. STILL MAY BE SOME ISOLATED -SHRA LASTING INTO THE
EVENING...SO HAVE MAINTAINED VCSH AT THE ST. LOUIS METRO TAF
SITES. EXPECT VFR CONDITIONS TO PREVAIL THE LAST HALF OF THE TAF
PERIOD.

SPECIFICS FOR KSTL...AS MENTIONED ABOVE...NEW CELL HAS RECENTLY
DEVELOPED JUST NORTHWEST OF THE TERMINAL...SO HAVE STARTED THE
TEMPO GROUP FOR -TSRA AT 18Z AND WILL CONTINUE IT UNTIL 21Z WHEN I
STILL EXPECT FROPA. WILL MAINTAIN MVFR CAT WITH THE TEMPO GROUP.
THERE STILL MAY BE SOME ISOLATED LIGHT -SHRA BEHIND THE FRONT INTO
EARLY EVENING...SO WILL KEEP VCSH FOR NOW. OTHERWISE EXPECT DRY
AND VFR CONDITIONS OVERNIGHT AND FRIDAY.

BRITT

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION...UPDATED

NWS ST LOUIS MO

 1051 AM CDT THU AUG 16 2012

.UPDATE...
ISSUED AT 1051 AM CDT THU AUG 16 2012

COLD FRONT HAS NOW MOVED TO NEAR A EOK-IRK-SZL AT 15Z. MAIN CLUSTER
OF THUNDERSTORMS ARE STAYING NORTH AND NORTHEAST OF THE CWA AHEAD
OF A VORT MAX OVER FAR EASTERN IOWA. STILL EXPECT SOME DEVELOPMENT
FARTHER SOUTH THE NEXT FEW HOURS AS THE RAP IS SHOWING DECENT SURFACE-
850MB MOISTURE CONVERGENCE DEVELOPING ALONG THE FRONT BETWEEN 18-21Z.
LATEST SPC OBJECTIVE ANALYSIS IS SHOWING MIXED LAYER CAPES OF 2000-2500
J/KG SOUTH OF THE FRONT WITH RAP FORECAST SOUNDINGS SHOWING THE CINH
ERODING BY EARLY AFTERNOON. PREDOMINANT CONVECTIVE MODE STILL LOOKS
LIKE IT WILL BE FROM MULTI-CELL STORMS AS BEST DEEP LAYER SHEAR
REMAINS NORTH OF THE AREA.

HAVE TRIMMED BACK LIKELY POPS FROM CENTRAL MISSOURI INTO WEST
CENTRAL ILLINOIS WHERE THE FRONT HAS ALREADY MOVED SOUTH. FARTHER
SOUTH...HAVE MAINTAINED LIKELY POPS AHEAD OF THE FRONT GIVEN THAT
LOW LEVEL CONVERGENCE WILL BE PERSISTENT WITH THE ERODING CINH.
WILL KEEP CHANCE POPS OVER NORTHEAST MISSOURI AND WEST CENTRAL
ILLINOIS THIS AFTERNOON WHICH WILL HAVE WEAK ASCENT FROM THE TAIL
END OF THE MAIN SHORTWAVE TROUGH MOVING EAST THROUGH THE UPPER
MIDWEST.

BRITT

&&

.SHORT TERM...
ISSUED AT 248 AM CDT THU AUG 16 2012
(TODAY AND TONIGHT)

AS OF THIS WRITING...THE CDFNT THAT IS EXPECTED TO BRING TSRA TO
THE REGION TODAY IS JUST NOW REACHING FAR NWRN TIP OF MO. THE
FORECAST WILL LIKELY TAKE ON A NUMBER OF ITERATIONS TODAY AS A
NUMBER OF QUESTIONS REMAIN WITH MDLS OFFERING A WIDE VARIETY OF
SOLNS.

STRONG WAA EVIDENT IN SATELLITE IMAGERY THIS MORNING WITH ACCAS
AND ISOD SHRA ALREADY DEVELOPED IN CNTL IL STRETCHING WWD INTO W
CNTL IL. WHILE THIS IS DEPICTED IN THE NAM...THE NAM OBVIOUSLY
DOES NOT HAVE ENUF OF A CAP IN PLACE GIVEN FORECAST SOUNDINGS AND
PRECIP OUTPUT. THIS STRONG WAA SHUD ALSO HELP TO PUT A CAP IN
PLACE AHEAD OF THE CDFNT PREVENTING ANY CONVECTION UNTIL EITHER
LATE THIS MORNING OR INTO THE AFTERNOON.

IN GENERAL...BELIEVE TSRA WILL BE LIMITED TO NRN COUNTIES LATE
THIS MORNING AS ONGOING TSRA DIMINISH WITH LOSS OF LLJ. SINCE THE
BEST FORCING AND WEAKEST CAP WILL BE ALONG THE FNT...HAVE TIMED
THE HIGHEST POPS TO BE CO-LOCATED WITH THE FNT. THAT SAID...WITH
DEWPOINTS REACHING INTO THE UPPER 60S...IT SHUD NOT TAKE TOO MUCH
HEATING FOR PARCELS TO BECOME UNSTABLE.

AS FOR THE SVR THREAT...MDLS CONTINUE TO PROG K INDEX VALUES
AROUND 40C. THIS WUD NORMALLY SUGGEST TSRA WILL BE TOO WATER LADEN
TO PRODUCE MUCH IN THE WAY OF SVR WX. HOWEVER...MDL MOISTURE
PROFILE MAY BE OVERDONE. EVEN IF TSRA ARE WATER LADEN...STEEP LOW
LEVEL LAPSE RATES WILL POSE A WIND THREAT ACROSS THE REGION. ANY
OUTFLOW BOUNDARY MAY MODIFY THE ENVIRONMENT AND INCREASE SHEAR
ENUF TO SUPPORT LARGE HAIL LATER IN THE DAY. THIS THREAT SHUD
LINGER INTO AT LEAST THE EARLY EVENING.

THE NAM IS NOW THE ONLY MDL SUGGESTING STRONG FRONTOGENESIS THIS
EVENING PRODUCING TSRA BEHIND THE FNT. WHILE THIS WUD GENERALLY
SUGGEST SHRA...PROG SOUNDINGS HAVE ELEVATED PARCELS UNCAPPED WITH
STRONG FORCING AND HIGH CAPE. IT IS DOUBTFUL HOWEVER THAT ANY SVR
TSRA WILL OCCUR BEHIND THE FNT AS EARLIER ACTIVITY WILL GREATLY
MODIFY THE ATMO AS THE FNT MOVES THRU THE REGION.

AS FOR TEMPS...HAVE TRENDED TWD THE WARM SOLNS...ESP S OF THE FNT.
ALSO TRENDED TWD THE COOLER SOLNS TONIGHT BEHIND THE FNT AS SKIES
CLEAR OUT ACROSS NRN PORTIONS OF THE CWA. OVERALL...THIS RESULTS
IN VERY FEW CHANGES TO THE PREV FORECAST.

TILLY

&&

.LONG TERM...
ISSUED AT 338 AM CDT THU AUG 16 2012
(SATURDAY THROUGH WEDNESDAY)

BEHIND THE CDFNT MENTIONED ABOVE...A LARGE SFC RIDGE WILL SETTLE
INTO THE REGION. HAVE KEPT SLIGHT CHANCE POPS FRI MORNING TO
ACCOUNT FOR ANY LINGERING TSRA LEFT OVER FROM TONIGHT BUT BULK OF
THE ACTIVITY IS EXPECTED TO BE S OF THE CWA.

NW FLOW WILL SETTLE OVER THE REGION WHICH PRESENTS A BIG FORECAST
CHALLENGE. ANY SUBTLE S/W MAY BE ENUF TO GENERATE PRECIP. MDLS
STILL IN GENERALLY GOOD AGREEMENT WITH A S/W DROPPING INTO THE
REGION LATE SAT INTO SUN. HOWEVER...WITH MUCH OF THE MO/IL REGION
LACKING MUCH IN THE WAY OF MOISTURE...IT CURRENTLY APPEARS THIS
S/W WILL NOT GENERATE PRECIP FOR THE CWA.

OTHERWISE...FORECAST REMAINS DRY THRU THE PERIOD WITH BELOW
SEASONAL AVERAGE TEMPS. MDLS IN FAIRLY GOOD AGREEMENT THRU TUES
WITH THE AREA REMAINING IN NW FLOW. BEYOND TUES...THE ECMWF/GEM
SUGGEST A SYSTEM REINFORCING THE UPPER TROF WHILE THE GFS SUGGESTS
THE UPPER RIDGE STARTING TO BUILD BACK INTO THE REGION. DUE TO THE
LARGE DIFFERENCES...HAVE TRENDED TWD A BLEND OF GUIDANCE WHICH
RESULTS NEAR CLIMO. WILL MAKE ADJUSTMENTS AS MDLS COME INTO BETTER
AGREEMENT.

TILLY

&&

.AVIATION...
ISSUED AT 630 AM CDT THU AUG 16 2012

LOTS OF UNCERTAINTY WITH REGARDS TO THE SHOWER AND THUNDERSTORM
THREAT AT THE TERMINALS. MODEL SOLUTIONS WOULD SUGGEST THERE
SHOULD ALREADY BE SCATTERED SHOWERS AND THUNDERSTORMS ACROSS
NORTHERN MISSOURI INTO CENTRAL ILLINOIS...AND THIS IS NOT THE
CASE. SEEMS LIKE THE BEST THREAT OF SHOWERS AND THUNDERSTORMS
SHOULD BE IN A 2-3 HOUR WINDOW IN ADVANCE OF THE COLD FRONT
PASSAGE AND THAT IS HOW THE TERMINALS HAVE BEEN COMPOSED. GIVEN
THE UNCERTAINTY I HAVE JUST MENTIONED SHOWERS IN KUIN AND KCOU.
TIMING OF THE FRONT THROUGH THE ST LOUIS AREA IS BETTER FOR
THUNDERSTORMS WITH PASSAGE DURING PEAK INSTABILITY. SOME OF THE
PREVIOUS MODEL SOLUTIONS WERE SUGGESTING A WEST-EAST BAND OF POST-
FRONTAL RAIN WOULD DEVELOP THIS EVENING ALONG OR JUST SOUTH OF
INTERSTATE 70. THIS SCENARIO HAS BECOME AN OUTLIER IN THE CURRENT
DATA AND THEREFORE HAVE BEGUN TO DOWNPLAY IT AND JUST MENTIONED
VCSH. EXPECTING VFR CONDITIONS TO PREVIAL OUTSIDE OF ANY
PRECIPITATION.

SPECIFICS FOR KSTL...

HAVE BACKED OFF ON THE TIMING OF ANY PRECIPITATION THREAT IN THE
NEW FORECAST. SEEMS LIKE THE BEST THREAT OF SHOWERS AND THUNDERSTORMS
SHOULD BE IN A 2-3 HOUR WINDOW IN ADVANCE OF THE COLD FRONT PASSAGE...AND
THE CURRENT PROJECTION HAS FROPA AROUND 21Z. SOME OF THE PREVIOUS
MODEL SOLUTIONS WERE SUGGESTING A WEST-EAST BAND OF POST-FRONTAL
RAIN WOULD DEVELOP THIS EVENING ALONG OR JUST SOUTH OF INTERSTATE
70. THIS SCENARIO HAS BECOME AN OUTLIER IN THE CURRENT DATA AND
THEREFORE HAVE BEGUN TO DOWNPLAY IT AND JUST MENTIONED VCSH.
EXPECTING VFR CONDITIONS TO PREVIAL OUTSIDE OF ANY PRECIPITATION.

GLASS

&&

.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&

$$

WFO LSX







AREA FORECAST DISCUSSION...CORRECTED

NWS HASTINGS NE

 701 PM CDT FRI AUG 17 2012

.AVIATION...00Z KGRI TAF. BIGGEST CONCERN WILL BE CHANCE OF
PRECIPITATION COMING UP IN ASSOCIATION WITH AN OCCLUDED FRONT. IT
APPEARS THAT THE TREND IS FOR PRECIPITATION ARRIVING TOWARD EARLY-
MID MORNING. CEILINGS WILL NOT BE ALL THAT LOW AND THE DURATION OF
ANY RAIN WILL BE SHORT-LIVED...WITH JUST ENOUGH INSTABILITY TO
THROW IN THUNDER.

&&

.PREV DISCUSSION... /ISSUED 408 PM CDT FRI AUG 17 2012/

SHORT TERM...THROUGH SATURDAY DAYTIME. PRIMARY ISSUE DURING THE
NEXT 24 HOURS IS TRYING TO PIN DOWN HIGH WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY WILL BE LATE TONIGHT INTO THE DAYTIME
SATURDAY...AND THE RESULTANT EFFECTS ON HIGH TEMPERATURES.

19Z OBJECTIVE SURFACE ANALYSIS REVEALS AN INCREDIBLY PLEASANT
AFTERNOON ACROSS THE CWA WITH VERY LIGHT BREEZES...THANKS TO A
1020MB RIDGE AXIS PARKED DIRECTLY OVER THE AREA AND EXTENDING
NORTHEAST INTO MN. VISIBLE SATELLITE CONFIRMS NEARLY CLOUD-FREE
SKIES ACROSS THE NORTHEAST 1/2 OF THE CWA...WHILE IN THE
SOUTHWEST...WHAT WAS A FAIRLY SOLID MID LEVEL CLOUD DECK A FEW
HOURS AGO HAS STEADILY ERODED/SCATTERED OUT QUITE A BIT. WATER
VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA DEPICTS
THE CWA UNDER SEASONABLY STRONG NORTHWEST FLOW ALOFT...SANDWICHED
BETWEEN A LARGE SCALE TROUGH OVER THE NORTHEAST CONUS WHICH IS
ANCHORED BY A VIGOROUS VORT MAX OVER EASTERN QUEBEC...AND A BROAD
RIDGE CENTERED FROM THE INTERMOUNTAIN WEST TO SOUTH TX. THE QUICK
MOVING SHORTWAVE/SPEED MAX THAT WILL BRING PRECIP CHANCES LATE
TONIGHT INTO SATURDAY IS CURRENTLY EVIDENT DROPPING SOUTHEAST NEAR
THE MT/ND/CANADA BORDER. TEMPS THIS AFTERNOON ARE VERY MUCH ON
TRACK WITH PREVIOUS FORECAST HIGHS...AND MAY ACTUALLY EXCEED THEM
SLIGHTLY IN SOME AREAS AS A FEW POTS ARE MAKING A RUN AT REACHING
80. AS SUGGESTED IN THE EARLIER UPDATE DISCUSSION...LIMITED MIXING
INTO VERY DRY AIR ALOFT HAS ALLOWED SURFACE DEWPOINTS TO FALL INTO
THE UPPER 30S IN SOME AREAS...ALTHOUGH LOW 40S ARE PREVALENT.

FOR THIS EVENING/TONIGHT...THE MOST SIGNIFICANT CHANGE WAS TO
COMPLETELY REMOVE ALL MENTION OF SHOWERS/STORMS BEFORE 06Z...AS
MOISTURE RETURN AND RESULTANT ELEVATED INSTABILITY NOW APPEARS
CONSIDERABLY MORE DELAYED THAN IT DID 24 HOURS AGO. THAT BEING
SAID...LATEST RAP-BASED HOURLY MESOANALYSIS INDICATED THE
PRESENCE OF UP TO 500 J/KG MUCAPE CURRENTLY SITTING ACROSS
SOUTHWEST ZONES ALONG THE LEADING EDGE OF MOISTURE RETURN AROUND
700MB. HOWEVER THE 12Z NAM WOULD SUGGEST THIS MUCAPE IS ACTUALLY
MORE MEAGER AND MORE CAPPED THAN THE RAP SUGGESTS...AND GIVEN THE
LIMITED FORCING AND THE FACT THAT A NUMBER OF DETERMINISTIC AND
HIGH RES MODELS SUCH AS THE 12Z 4KM WRF-NMM DO NOT INITIATE
CONVECTION IN THIS AREA THROUGH THIS EVENING...HAVE REMOVED THE
SLIGHT POPS. FOR THE LATE NIGHT 06Z-12Z PERIOD...DECIDED TO BREAK
THE POP/WX GRIDS INTO 3-HOUR BLOCKS...WITH THE PRIMARY FOCUS
SQUARELY ON THE VERY LATE NIGHT/EARLY MORNING HOURS POST-09Z. FOR
THE 06Z-09Z PERIOD...ONLY HAVE SLIGHT POPS CREEPING INTO A FEW FAR
SOUTHWEST COUNTIES. THEN AFTER 09Z...BRING IN 20-30 PERCENT
SHOWER/ISOLATED STORM CHANCES FOR ALL BUT ROUGHLY THE EASTERN 1/4
OF THE CWA. AS THE NIGHT WEARS ON...THE AFOREMENTIONED NORTHWEST
FLOW SHORTWAVE WILL REACH THE SD/NORTHERN NEB BORDER AREA...WHILE
OUT AHEAD OF IT...THETA-E ADVECTION MAINLY IN THE 850-700MB LAYER
WILL BE ON THE INCREASE...AS THE EASTERN EDGE OF A MODEST 850MB
LOW LEVEL JET VEERS INTO THE AREA. INTERESTINGLY...THE NEWLY
ARRIVED 18Z NAM KEEPS MOST ALL OF THIS ACTIVITY OUTSIDE THE CWA
UNTIL AFTER SUNRISE...BUT FEEL AT LEAST 20-30 POPS ARE WARRANTED
BASED ON THE 4KM WRF-NMM AND NSSL 4KM-WRF DEPICTION OF ONE BATCH
OF SHOWERS/FEW STORMS SLIDING INTO THE CWA FROM THE
NORTHWEST...WHILE ANOTHER POTENTIALLY SEPARATE AREA DEVELOPS OVER
THE SOUTHWESTERN CWA MAINLY IN KS. ALTHOUGH NOT ANTICIPATING A
SEVERE WEATHER THREAT THROUGH SUNRISE WITH MUCAPE LIKELY REMAINING
NO MORE THAN A FEW HUNDRED J/KG...SUPPOSE A FEW STRONGER CORES
WITH SMALL HAIL CANNOT BE RULED OUT GIVEN STRONG DEEP LAYER SHEAR
ON THE ORDER OF 50+ KNOTS. TEMP WISE TONIGHT...GIVEN THE SLOWER
ONSET OF CLOUDS AND STORM CHANCES...AND WITH WINDS REMAINING LIGHT
AS THE RIDGE AXIS SLOWLY DEPARTS...NUDGED DOWN LOWS TONIGHT 2-3
DEGREES IN MOST AREAS...WITH MUCH OF THE CWA AIMED INTO THE 50-53
RANGE...AND EVEN COOLER MID-UPPER 40S IN THE FAR EAST...BUT NOT
RECORD-BREAKING TERRITORY.

TURNING TO THE DAYTIME PERIOD 12Z-00Z...SPLIT THE DAY INTO 6-HOUR
BLOCKS FOR POPS/WEATHER...WITH THE OVERALL BEST RAIN CHANCES FOCUSED
DURING THE MORNING. ALOFT...THE COMPACT BUT FAIRLY VIGOROUS
NORTHWEST FLOW WAVE WILL DIVE SOUTHWARD ACROSS THE EASTERN HALF OF
NEBRASKA TOWARD NORTHEAST KANSAS DURING THE DAY...ACCOMPANIED BY
AN ASSOCIATED UPPER LEVEL JET STREAK. ALTHOUGH IT WILL NOT BE AN
ALL-DAY RAIN OUT BY ANY MEANS...THE CONSENSUS OF VARIOUS MODELS
INCLUDING THE 12Z 4KM WRF-NMM REFLECTIVITY SHOWS A DECENT CHANCE
FOR AT LEAST SCATTERED SHOWERS/A FEW STORMS SPREADING SOUTHEAST
ACROSS THE CWA DURING THE DAY...POSSIBLY IN TWO SEPARATE ROUNDS
WITH ONE ROUND DURING THE MORNING...FOLLOWED BY MORE HIT AND MISS
ACTIVITY DURING THE AFTERNOON DIRECTLY UNDER THE SHORTWAVE AXIS.
WITH THE OVERALL BEST COVERAGE EXPECTED DURING THE MORNING
HOURS...INCREASED POPS TO 50S ACROSS ROUGHLY THE NORTHWEST 1/2 OF
THE CWA...BUT KEPT THEM BELOW LIKELY TERRITORY FOR NOW. DURING THE
AFTERNOON...WENT LOWER WITH POPS BUT KEPT AT LEAST 20-30 PERCENT
CHANCES AND HIGHEST ACROSS THE EASTERN 1/2. AS FOR SEVERE
CHANCES...WITH BOTH ELEVATED AND NEAR SURFACE-BASED PARCELS NOT
EXPECTED TO AVERAGE MORE THAN 500 J/KG MOST AREAS...WHICH CAME IN
LOWER ON THE 18Z NAM THAN ITS 12Z RUN...NOT EXPECTING SEVERE
STORMS TO BE A BIG ISSUE. HOWEVER...GIVEN THE VIGOROUS WAVE AND
CONTINUED SEASONABLY STRONG DEEP LAYER SHEAR...AT LEAST A FEW
STRONG TO MARGINALLY SEVERE STORMS MAINLY WITH HAIL POTENTIAL TO
AROUND QUARTER SIZE ARE NOT OUT OF THE QUESTION...ESPECIALLY IN
KANSAS ZONES...AND AGREE WITH SPC ON HIGHLIGHTING THESE SOUTHERN
ZONES FOR 5 PERCENT SEVERE PROBS ON THE DAY 2 OUTLOOK. AS FOR RAIN
AMOUNTS SATURDAY...WOULD EXPECT THAT MOST PLACES WILL AVERAGE
UNDER ONE-QUARTER INCH...SO NOT A MAJOR BOOST TO DROUGHT RELIEF BY
ANY MEANS. TEMP-WISE...IT WILL BE A TRICKY BATTLE BETWEEN
WIDESPREAD CLOUDS/SCATTERED RAIN FOR THE MAJORITY OF THE DAY...BUT
POTENTIAL FOR DECENT AFTERNOON CLEARING ESPECIALLY NORTHWEST.
OVERALL MADE NO BIG CHANGES...BUT RAISED WESTERN ZONES A FEW
DEGREES...ESPECIALLY UP AROUND ORD. HAVE MOST OF THE CWA TOPPING
OUT IN THE 76-81 RANGE.

LONG TERM...STARTING SATURDAY EVENING. GUIDANCE SUGGESTS
NORTHWESTERLY UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL
PLAINS THROUGH MUCH OF THE EXTENDED FORECAST PERIOD AS UPPER LEVEL
RIDGING REMAINS RELEGATED TO THE SOUTHWESTERN CONUS. QPF FIELDS
FROM THE SREF- MEAN...NAM AND OPERATIONAL GFS SUGGEST LINGERING
PRECIPITATION WILL BE POSSIBLE OVER OUR SOUTHEASTERN CWA 00Z-06Z
SUNDAY AS A MID LEVEL SHORT WAVE DEPARTS THE AREA. AS A
RESULT...WENT AHEAD AND KEPT 20% POPS GOING ACROSS OUR SOUTHEAST
00Z-06Z SUNDAY. A FEW SMALL-SCALE MID LEVEL PERTURBATIONS COULD
POTENTIALLY PUSH OVER THE CENTRAL PLAINS SUNDAY AND MONDAY.
DESPITE THE POSSIBILITY OF THESE SMALL-SCALE DISTURBANCES...OPTED
TO KEEP THE CWA DRY DURING THIS TIME PERIOD GIVEN THE VERY LOW
PROBABILITY OF PRECIPITATION ACTUALLY BEING REALIZED FROM ANY ONE
OF THESE FEATURES. THE EC...OPERATIONAL GFS AND GEFS-MEAN ALL
ADVERTISE A MORE SIGNIFICANT MID LEVEL SHORT WAVE WILL PUSH
SOUTHEAST ACROSS THE CENTRAL HIGH PLAINS MONDAY NIGHT INTO
TUESDAY. AT THIS TIME IT APPEARS THE BULK OF THE DPVA AND MID
LEVEL THERMAL ADVECTION WILL REMAIN SOUTHWEST OF OUR AREA...BUT
THERE MAY BE JUST ENOUGH OMEGA FOR PRECIPITATION ACROSS OUR
WEST/SOUTHWEST AND AS A RESULT...WENT AHEAD AND KEPT 20%-30% POPS
GOING ACROSS OUR WEST/SOUTHWEST FOR MONDAY NIGHT. SOME OF THIS
OMEGA MAY CREEP A BIT FARTHER EAST INTO OUR AREA DURING THE DAY
TUESDAY SO WENT AHEAD AND SPREAD POPS A BIT FARTHER EAST ACROSS
THE CWA DURING THE DAY TUESDAY AS A RESULT. AN OVERALL LACK IN
KINEMATIC FORCING SHOULD THEN PRESENT DRY CONDITIONS TO OUR AREA
TUESDAY NIGHT THROUGH THURSDAY...WITH GUIDANCE SUGGESTING YET
ANOTHER MID LEVEL SHORT WAVE WILL BRING PRECIPITATION CHANCES TO
MUCH OF THE AREA THURSDAY NIGHT INTO FRIDAY.

VERY LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS TEMPERATURES
SUNDAY THROUGH FRIDAY WILL BE FAIRLY SIMILAR...WITH PERHAPS A SLIGHT
WARMING TREND TOWARDS THE END OF THE FORECAST PERIOD. GIVEN
THIS...BELOW-NORMAL TEMPERATURES ARE FORECAST ACROSS THE CWA SUNDAY
WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER 40S TO NEAR 50.
SLIGHTLY WARMER BUT STILL BELOW-NORMAL TEMPERATURES ARE THEN
FORECAST FOR MUCH OF THE CWA MONDAY BEFORE WEAK LOW LEVEL WARM
ADVECTION PROVIDES NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES
TUESDAY ONWARD.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$

AVIATION...HEINLEIN
SHORT TERM...PFANNKUCH
LONG TERM...BRYANT





AREA FORECAST DISCUSSION

NWS HASTINGS NE

 700 PM CDT FRI AUG 17 2012

.AVIATION...00Z KGRI TAF. BIGGEST CONCERN WILL BE CHANCE OF
PRECIPIATION COMING UP IN ASSOCIATION WITH AN OCCLUDED FRONT. IT
APPEARS THAT THE TREND IS FOR PRECIPIATION ARRIVING TOWARD EARLY-
MID MORNING. CEILINGS WILL NOT BE ALL THAT LOW AND THE DURATION OF
ANY RAIN WILL BE SHORT-LIVED...WITH JUST ENOUGH INSTABILITY TO
THROW IN THUNDER.

&&

.PREV DISCUSSION... /ISSUED 408 PM CDT FRI AUG 17 2012/

SHORT TERM...THROUGH SATURDAY DAYTIME. PRIMARY ISSUE DURING THE
NEXT 24 HOURS IS TRYING TO PIN DOWN HIGH WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY WILL BE LATE TONIGHT INTO THE DAYTIME
SATURDAY...AND THE RESULTANT EFFECTS ON HIGH TEMPERATURES.

19Z OBJECTIVE SURFACE ANALYSIS REVEALS AN INCREDIBLY PLEASANT
AFTERNOON ACROSS THE CWA WITH VERY LIGHT BREEZES...THANKS TO A
1020MB RIDGE AXIS PARKED DIRECTLY OVER THE AREA AND EXTENDING
NORTHEAST INTO MN. VISIBLE SATELLITE CONFIRMS NEARLY CLOUD-FREE
SKIES ACROSS THE NORTHEAST 1/2 OF THE CWA...WHILE IN THE
SOUTHWEST...WHAT WAS A FAIRLY SOLID MID LEVEL CLOUD DECK A FEW
HOURS AGO HAS STEADILY ERODED/SCATTERED OUT QUITE A BIT. WATER
VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA DEPICTS
THE CWA UNDER SEASONABLY STRONG NORTHWEST FLOW ALOFT...SANDWICHED
BETWEEN A LARGE SCALE TROUGH OVER THE NORTHEAST CONUS WHICH IS
ANCHORED BY A VIGOROUS VORT MAX OVER EASTERN QUEBEC...AND A BROAD
RIDGE CENTERED FROM THE INTERMOUNTAIN WEST TO SOUTH TX. THE QUICK
MOVING SHORTWAVE/SPEED MAX THAT WILL BRING PRECIP CHANCES LATE
TONIGHT INTO SATURDAY IS CURRENTLY EVIDENT DROPPING SOUTHEAST NEAR
THE MT/ND/CANADA BORDER. TEMPS THIS AFTERNOON ARE VERY MUCH ON
TRACK WITH PREVIOUS FORECAST HIGHS...AND MAY ACTUALLY EXCEED THEM
SLIGHTLY IN SOME AREAS AS A FEW POTS ARE MAKING A RUN AT REACHING
80. AS SUGGESTED IN THE EARLIER UPDATE DISCUSSION...LIMITED MIXING
INTO VERY DRY AIR ALOFT HAS ALLOWED SURFACE DEWPOINTS TO FALL INTO
THE UPPER 30S IN SOME AREAS...ALTHOUGH LOW 40S ARE PREVALENT.

FOR THIS EVENING/TONIGHT...THE MOST SIGNIFICANT CHANGE WAS TO
COMPLETELY REMOVE ALL MENTION OF SHOWERS/STORMS BEFORE 06Z...AS
MOISTURE RETURN AND RESULTANT ELEVATED INSTABILITY NOW APPEARS
CONSIDERABLY MORE DELAYED THAN IT DID 24 HOURS AGO. THAT BEING
SAID...LATEST RAP-BASED HOURLY MESOANALYSIS INDICATED THE
PRESENCE OF UP TO 500 J/KG MUCAPE CURRENTLY SITTING ACROSS
SOUTHWEST ZONES ALONG THE LEADING EDGE OF MOISTURE RETURN AROUND
700MB. HOWEVER THE 12Z NAM WOULD SUGGEST THIS MUCAPE IS ACTUALLY
MORE MEAGER AND MORE CAPPED THAN THE RAP SUGGESTS...AND GIVEN THE
LIMITED FORCING AND THE FACT THAT A NUMBER OF DETERMINISTIC AND
HIGH RES MODELS SUCH AS THE 12Z 4KM WRF-NMM DO NOT INITIATE
CONVECTION IN THIS AREA THROUGH THIS EVENING...HAVE REMOVED THE
SLIGHT POPS. FOR THE LATE NIGHT 06Z-12Z PERIOD...DECIDED TO BREAK
THE POP/WX GRIDS INTO 3-HOUR BLOCKS...WITH THE PRIMARY FOCUS
SQUARELY ON THE VERY LATE NIGHT/EARLY MORNING HOURS POST-09Z. FOR
THE 06Z-09Z PERIOD...ONLY HAVE SLIGHT POPS CREEPING INTO A FEW FAR
SOUTHWEST COUNTIES. THEN AFTER 09Z...BRING IN 20-30 PERCENT
SHOWER/ISOLATED STORM CHANCES FOR ALL BUT ROUGHLY THE EASTERN 1/4
OF THE CWA. AS THE NIGHT WEARS ON...THE AFOREMENTIONED NORTHWEST
FLOW SHORTWAVE WILL REACH THE SD/NORTHERN NEB BORDER AREA...WHILE
OUT AHEAD OF IT...THETA-E ADVECTION MAINLY IN THE 850-700MB LAYER
WILL BE ON THE INCREASE...AS THE EASTERN EDGE OF A MODEST 850MB
LOW LEVEL JET VEERS INTO THE AREA. INTERESTINGLY...THE NEWLY
ARRIVED 18Z NAM KEEPS MOST ALL OF THIS ACTIVITY OUTSIDE THE CWA
UNTIL AFTER SUNRISE...BUT FEEL AT LEAST 20-30 POPS ARE WARRANTED
BASED ON THE 4KM WRF-NMM AND NSSL 4KM-WRF DEPICTION OF ONE BATCH
OF SHOWERS/FEW STORMS SLIDING INTO THE CWA FROM THE
NORTHWEST...WHILE ANOTHER POTENTIALLY SEPARATE AREA DEVELOPS OVER
THE SOUTHWESTERN CWA MAINLY IN KS. ALTHOUGH NOT ANTICIPATING A
SEVERE WEATHER THREAT THROUGH SUNRISE WITH MUCAPE LIKELY REMAINING
NO MORE THAN A FEW HUNDRED J/KG...SUPPOSE A FEW STRONGER CORES
WITH SMALL HAIL CANNOT BE RULED OUT GIVEN STRONG DEEP LAYER SHEAR
ON THE ORDER OF 50+ KNOTS. TEMP WISE TONIGHT...GIVEN THE SLOWER
ONSET OF CLOUDS AND STORM CHANCES...AND WITH WINDS REMAINING LIGHT
AS THE RIDGE AXIS SLOWLY DEPARTS...NUDGED DOWN LOWS TONIGHT 2-3
DEGREES IN MOST AREAS...WITH MUCH OF THE CWA AIMED INTO THE 50-53
RANGE...AND EVEN COOLER MID-UPPER 40S IN THE FAR EAST...BUT NOT
RECORD-BREAKING TERRITORY.

TURNING TO THE DAYTIME PERIOD 12Z-00Z...SPLIT THE DAY INTO 6-HOUR
BLOCKS FOR POPS/WEATHER...WITH THE OVERALL BEST RAIN CHANCES FOCUSED
DURING THE MORNING. ALOFT...THE COMPACT BUT FAIRLY VIGOROUS
NORTHWEST FLOW WAVE WILL DIVE SOUTHWARD ACROSS THE EASTERN HALF OF
NEBRASKA TOWARD NORTHEAST KANSAS DURING THE DAY...ACCOMPANIED BY
AN ASSOCIATED UPPER LEVEL JET STREAK. ALTHOUGH IT WILL NOT BE AN
ALL-DAY RAIN OUT BY ANY MEANS...THE CONSENSUS OF VARIOUS MODELS
INCLUDING THE 12Z 4KM WRF-NMM REFLECTIVITY SHOWS A DECENT CHANCE
FOR AT LEAST SCATTERED SHOWERS/A FEW STORMS SPREADING SOUTHEAST
ACROSS THE CWA DURING THE DAY...POSSIBLY IN TWO SEPARATE ROUNDS
WITH ONE ROUND DURING THE MORNING...FOLLOWED BY MORE HIT AND MISS
ACTIVITY DURING THE AFTERNOON DIRECTLY UNDER THE SHORTWAVE AXIS.
WITH THE OVERALL BEST COVERAGE EXPECTED DURING THE MORNING
HOURS...INCREASED POPS TO 50S ACROSS ROUGHLY THE NORTHWEST 1/2 OF
THE CWA...BUT KEPT THEM BELOW LIKELY TERRITORY FOR NOW. DURING THE
AFTERNOON...WENT LOWER WITH POPS BUT KEPT AT LEAST 20-30 PERCENT
CHANCES AND HIGHEST ACROSS THE EASTERN 1/2. AS FOR SEVERE
CHANCES...WITH BOTH ELEVATED AND NEAR SURFACE-BASED PARCELS NOT
EXPECTED TO AVERAGE MORE THAN 500 J/KG MOST AREAS...WHICH CAME IN
LOWER ON THE 18Z NAM THAN ITS 12Z RUN...NOT EXPECTING SEVERE
STORMS TO BE A BIG ISSUE. HOWEVER...GIVEN THE VIGOROUS WAVE AND
CONTINUED SEASONABLY STRONG DEEP LAYER SHEAR...AT LEAST A FEW
STRONG TO MARGINALLY SEVERE STORMS MAINLY WITH HAIL POTENTIAL TO
AROUND QUARTER SIZE ARE NOT OUT OF THE QUESTION...ESPECIALLY IN
KANSAS ZONES...AND AGREE WITH SPC ON HIGHLIGHTING THESE SOUTHERN
ZONES FOR 5 PERCENT SEVERE PROBS ON THE DAY 2 OUTLOOK. AS FOR RAIN
AMOUNTS SATURDAY...WOULD EXPECT THAT MOST PLACES WILL AVERAGE
UNDER ONE-QUARTER INCH...SO NOT A MAJOR BOOST TO DROUGHT RELIEF BY
ANY MEANS. TEMP-WISE...IT WILL BE A TRICKY BATTLE BETWEEN
WIDESPREAD CLOUDS/SCATTERED RAIN FOR THE MAJORITY OF THE DAY...BUT
POTENTIAL FOR DECENT AFTERNOON CLEARING ESPECIALLY NORTHWEST.
OVERALL MADE NO BIG CHANGES...BUT RAISED WESTERN ZONES A FEW
DEGREES...ESPECIALLY UP AROUND ORD. HAVE MOST OF THE CWA TOPPING
OUT IN THE 76-81 RANGE.

LONG TERM...STARTING SATURDAY EVENING. GUIDANCE SUGGESTS
NORTHWESTERLY UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL
PLAINS THROUGH MUCH OF THE EXTENDED FORECAST PERIOD AS UPPER LEVEL
RIDGING REMAINS RELEGATED TO THE SOUTHWESTERN CONUS. QPF FIELDS
FROM THE SREF- MEAN...NAM AND OPERATIONAL GFS SUGGEST LINGERING
PRECIPITATION WILL BE POSSIBLE OVER OUR SOUTHEASTERN CWA 00Z-06Z
SUNDAY AS A MID LEVEL SHORT WAVE DEPARTS THE AREA. AS A
RESULT...WENT AHEAD AND KEPT 20% POPS GOING ACROSS OUR SOUTHEAST
00Z-06Z SUNDAY. A FEW SMALL-SCALE MID LEVEL PERTURBATIONS COULD
POTENTIALLY PUSH OVER THE CENTRAL PLAINS SUNDAY AND MONDAY.
DESPITE THE POSSIBILITY OF THESE SMALL-SCALE DISTURBANCES...OPTED
TO KEEP THE CWA DRY DURING THIS TIME PERIOD GIVEN THE VERY LOW
PROBABILITY OF PRECIPITATION ACTUALLY BEING REALIZED FROM ANY ONE
OF THESE FEATURES. THE EC...OPERATIONAL GFS AND GEFS-MEAN ALL
ADVERTISE A MORE SIGNIFICANT MID LEVEL SHORT WAVE WILL PUSH
SOUTHEAST ACROSS THE CENTRAL HIGH PLAINS MONDAY NIGHT INTO
TUESDAY. AT THIS TIME IT APPEARS THE BULK OF THE DPVA AND MID
LEVEL THERMAL ADVECTION WILL REMAIN SOUTHWEST OF OUR AREA...BUT
THERE MAY BE JUST ENOUGH OMEGA FOR PRECIPITATION ACROSS OUR
WEST/SOUTHWEST AND AS A RESULT...WENT AHEAD AND KEPT 20%-30% POPS
GOING ACROSS OUR WEST/SOUTHWEST FOR MONDAY NIGHT. SOME OF THIS
OMEGA MAY CREEP A BIT FARTHER EAST INTO OUR AREA DURING THE DAY
TUESDAY SO WENT AHEAD AND SPREAD POPS A BIT FARTHER EAST ACROSS
THE CWA DURING THE DAY TUESDAY AS A RESULT. AN OVERALL LACK IN
KINEMATIC FORCING SHOULD THEN PRESENT DRY CONDITIONS TO OUR AREA
TUESDAY NIGHT THROUGH THURSDAY...WITH GUIDANCE SUGGESTING YET
ANOTHER MID LEVEL SHORT WAVE WILL BRING PRECIPITATION CHANCES TO
MUCH OF THE AREA THURSDAY NIGHT INTO FRIDAY.

VERY LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS TEMPERATURES
SUNDAY THROUGH FRIDAY WILL BE FAIRLY SIMILAR...WITH PERHAPS A SLIGHT
WARMING TREND TOWARDS THE END OF THE FORECAST PERIOD. GIVEN
THIS...BELOW-NORMAL TEMPERATURES ARE FORECAST ACROSS THE CWA SUNDAY
WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER 40S TO NEAR 50.
SLIGHTLY WARMER BUT STILL BELOW-NORMAL TEMPERATURES ARE THEN
FORECAST FOR MUCH OF THE CWA MONDAY BEFORE WEAK LOW LEVEL WARM
ADVECTION PROVIDES NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES
TUESDAY ONWARD.

PREV DISCUSSION... /ISSUED 1217 PM CDT FRI AUG 17 2012/

AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY IS FORECAST
THROUGH THE NEXT 24 HOURS...WITH THE MAIN CONCERN BEING A RISK FOR
SHOWERS/WEAK THUNDERSTORMS DURING PARTS OF THE FINAL 6 HOURS OF
THE PERIOD MAINLY SATURDAY MORNING. PRIOR TO THIS PRECIPITATION
POSSIBILITY...THE REST OF TODAY AND THROUGH TONIGHT WILL FEATURE
LIGHT/GENERALLY VARIABLE BREEZES AS A SURFACE HIGH PRESSURE AXIS
DEPARTS...ALONG WITH AT MOST A SMATTERING OF MID LEVEL CLOUD
COVER. FOR NOW...DECIDED TO GO WITH A PROB30 -TSRA MENTION FROM
12Z-18Z TO COVER THE THUNDERSTORM RISK...AND WILL DEFER TO LATER
FORECASTS TO INSERT POSSIBLE TEMPO/PREVAILING GROUPS AS THE EVENT
NEARS AND TIMING CONFIDENCE INCREASES. EVEN DURING POSSIBLE
THUNDERSTORM ACTIVITY...DO NOT FORESEE CEILING DROPPING EVEN CLOSE
TO MVFR THRESHOLDS...AND VISIBILITY SHOULD REMAIN VFR AS WELL
UNLESS A BRIEF HEAVY RAIN CORE SLIDES THROUGH.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS HASTINGS NE

 1208 AM CDT THU AUG 16 2012

.AVIATION...06Z TAF. COLD FRONT HAS SWEPT THROUGH THE TERMINAL
WITH STEADY NORTHERLY WINDS IN ITS WAKE...WITH GUSTS NEAR 30KTS.
WINDS WILL BE STEADY DURING THE NIGHT...THEN WILL DECREASE DURING
THE DAY ON THURSDAY AS SURFACE RIDGE SETTLES SOUTH ONTO THE PLAINS
AND GRADIENT RELAXES. FOR THE MOST PART...INTERMITTENT MID LEVEL
CLOUDS ARE EXPECTED TO ARRIVE OVERNIGHT AND INTO THE DAY THURSDAY
AND MODELS INDICATE DEVELOPMENT OF SCATTERED SHOWERS WITH THE
PASSAGE OF THE MID/UPPER TROUGH. CONDFIDENCE IN PCPN ACTIVITY IS
NOT EXTREMELY HIGH BUT DID INCLUDE MENTION FOR KGRI. CLOUDS SHLD
SCATTER TOWARD EVENING.

&&

.PREV DISCUSSION... /ISSUED 939 PM CDT WED AUG 15 2012/

UPDATE...HAVE INCREASINGLY BEEN LOSING CONFIDENCE IN THUNDERSTORM
DEVELOPMENT THIS EVENING. THE HRRR AND 00Z NAM CONTINUE TO TRY AND
DEVELOP CONVECTION ALONG THE FRONT...BUT THUS FAR THIS HAS NOT
MATERIALIZED AND IT SEEMS LESS LIKELY THAT IT WILL EVER
MATERIALIZE IN AT LEAST AN IMPACTFUL WAY. IT IS APPEARING MORE
LIKELY THAT MOST AREAS WILL ONCE AGAIN SEE A DRY NIGHT...OR MAYBE
A FEW POST FRONTAL SHOWERS DURING THE EARLY MORNING HOURS. EVEN IF
POST FRONTAL SHOWERS DEVELOP...THEY WILL LIKELY NOT BE BIG
PRECIPITATION PRODUCERS. THEREFORE...HAD TO DRASTICALLY CUT POPS
FOR THE REMAINDER OF TONIGHT FOR MOST NEBRASKA ZONES. THERE HAVE
BEEN A FEW THUNDERSTORMS OVER KANSAS ZONES AND HAVE ACTUALLY
INCREASED POPS ACROSS OUR FAR SOUTHERN KANSAS ZONES.

PREV DISCUSSION... /ISSUED 338 PM CDT WED AUG 15 2012/

SHORT TERM...THROUGH 00Z FRIDAY. MORNING UPPER AIR ANALYSIS
INDICATES UPPER LEVEL RIDGING OVER THE SOUTHWESTERN
CONUS...TROUGHING OVER THE EAST...AND A MID LEVEL SHORT WAVE OVER
SOUTH-CENTRAL CANADA AND THE NORTHERN PLAINS. UPPER LEVEL JET
ENERGY IS ALSO NOTED MEANDERING NORTH AND SOUTH FROM SOUTHWESTERN
AND SOUTHERN CANADA...AS WELL AS THE NORTHERN PLAINS ON INTO THE
EASTERN CONUS...AND A ~50KT MID LEVEL JET STREAK IS NOTED OVER
PORTIONS OF THE NORTHERN PLAINS ON THE SOUTH/SOUTHEAST SIDE OF THE
APPROACHING MID LEVEL SHORT WAVE. WATER VAPOR IMAGERY INDICATES A
DEVELOPING TROPICAL TAP OVER THE SOUTHWESTERN CONUS...BUT THIS
MOISTURE REMAINS RELEGATED TO OUR SOUTHWEST WITH MID LEVEL
MOISTURE OVER OUR AREA PRIMARILY BEING PULLED IN FROM THE PACIFIC
NORTHWEST BY THE APPROACHING MID LEVEL SHORT WAVE. A SURFACE LOW
IS NOTED OVER NORTHERN MINNESOTA...AHEAD OF THE MID LEVEL SHORT
WAVE...AND A COLD FRONT EXTENDS SOUTH/SOUTHWESTWARD FROM THE LOW
ACROSS THE DAKOTAS INTO CENTRAL NEBRASKA...AND THEN INTO
NORTHWESTERN KANSAS AND EASTERN COLORADO. AS OF 19Z THIS FRONT WAS
NOTED EXTENDING FROM NEAR KANW...TO KTIF...KLBF AND NEAR KIML. LOW
LEVEL FLOW REMAINS FROM THE SOUTH ACROSS MUCH OF OUR CWA AS A
RESULT...WITH A NORTHWESTERLY LOW LEVEL WIND FIELD NOTED BEHIND
THE LOW LEVEL BAROCLINIC ZONE ACROSS THE HIGH PLAINS. VISIBLE
SATELLITE IMAGERY INDICATES VERY LITTLE IN THE WAY OF CLOUD COVER
ACROSS NEBRASKA...BUT HIGH LEVEL CLOUDS AHEAD OF THE MID LEVEL
SHORT WAVE ARE BEGINNING TO ENTER THE STATE FROM SOUTH DAKOTA.
SMOKE IS ALSO EVIDENT ON VISIBILITY SATELLITE IMAGERY...ORIGINATING
FROM THE WILDFIRES CURRENTLY BURNING ACROSS WESTERN PORTIONS OF
THE CONUS.

SHORT TERM GUIDANCE CONTINUES TO SUGGEST THE NORTHERN PLAINS MID
LEVEL SHORT WAVE WILL CONTINUE MOVING EAST/SOUTHEAST TONIGHT INTO
TOMORROW. THIS WILL ALLOW THE SURFACE LOW...CURRENTLY OVER
NORTHERN MINNESOTA...TO PUSH EAST THUS ALLOWING THE LOW LEVEL
BAROCLINIC ZONE TO ALSO SWEEP EAST ACROSS OUR CWA. QPF FIELDS FROM
THE 15/12Z NAM AND 4KM WRF-NMM...AS WELL AS THE 15/14Z HRRR
SUGGEST CONVECTION WILL INITIATE NEAR OUR WEST/NORTHWESTERN CWA
ALONG THE LOW LEVEL BAROCLINIC ZONE AROUND 00Z. ISOLATED TO
PERHAPS SCATTERED PRECIPITATION IS THEN EXPECTED TO PUSH
EAST/SOUTHEAST ACROSS THE CWA. THE BEST DPVA AND MID LEVEL THERMAL
ADVECTION IS EXPECTED TO REMAIN OVER THE UPPER MISSISSIPPI
VALLEY...BUT THE SOUTH/SOUTHWESTERN MOST EXTENT OF THIS OMEGA MAY
CLIP OUR NORTH/NORTHEASTERN CWA AND AS A
RESULT...NORTH/NORTHEASTERN PORTIONS OF OUR CWA APPEAR MOST
FAVORED FOR PRECIPITATION THIS EVENING INTO TONIGHT. LOWER POPS
EXIST FARTHER SOUTHWEST ACROSS THE CWA WHERE BROAD-SCALE OMEGA
WILL BE WEAKER...BUT LOW LEVEL CONVERGENCE AND RESULTANT FORCING
ALONG THE LOW LEVEL BAROCLINIC ZONE MAY BE STRONG ENOUGH FOR
CONVECTIVE INITIATING AND RESULTANT PRECIPITATION PRODUCTION.
GIVEN ALL THIS...WENT AHEAD WITH 20% POPS ACROSS OUR FAR
WEST/NORTHWEST 21Z-00Z...WITH 20%-60% POPS SPREADING ACROSS MUCH
OF THE REST OF THE CWA 00Z-06Z. AGAIN...THE HIGHEST POPS HAVE BEEN
RELEGATED TO OUR NORTHEASTERN CWA. THE 15/12Z NAM SUGGESTS 0-1KM
MLCAPE VALUES OF ~1500J/KG WILL BE IN EXISTENCE ACROSS MUCH OF THE
CWA THIS AFTERNOON AND EVENING...WITH DEEP LAYER BULK SHEAR VALUES
OF 20-30KTS ALSO IN EXISTENCE. GIVEN THIS IT CERTAINLY APPEARS THE
GREATER RISK FOR SEVERE WEATHER THIS AFTERNOON AND EVENING WILL
EXIST FARTHER NORTHEAST INTO THE UPPER MISSISSIPPI VALLEY WHERE
GREATER VALUES OF INSTABILITY WILL BE OBSERVED...BUT AN ISOLATED
REPORT OF LARGE HAIL CANNOT BE RULED OUT ACROSS OUR AREA WITH THE
AFOREMENTIONED INSTABILITY IN PLACE. IN ADDITION...SIMULATED
REFLECTIVITY FIELDS FROM THE 15/12Z 4KM WRF-NMM SUGGEST A
QLCS...ALBEIT DISORGANIZED...COULD BE REALIZED ALONG THE LOW LEVEL
BAROCLINIC ZONE FROM THE UPPER MISSISSIPPI VALLEY INTO PORTIONS OF
THE MISSOURI RIVER VALLEY...WITH THE VERY SOUTHWESTERN EXTENT OF
THIS SYSTEM PERHAPS CLIPPING OUR NORTHEASTERN CWA. GIVEN ALL
THIS...WILL GO AHEAD AND CONTINUE TO CARRY SEVERE STORM WORDING IN
THE HWO FOR LATE THIS AFTERNOON THROUGH THIS EVENING...WITH
NORTHEASTERN PORTIONS OF OUR CWA THE MOST LIKELY AREA TO OBSERVE
SEVERE WEATHER ACROSS OUR AREA.

ANY SEVERE WEATHER THAT IS REALIZED SHOULD BE SHORT-LIVED AS THE
LOW LEVEL BAROCLINIC ZONE QUICKLY PUSHES AWAY FROM THE AREA BY 06Z
AND THE MID LEVEL TROUGH AXIS PUSHES WELL TO THE EAST/NORTHEAST OF
OUR AREA. THE OVERALL LACK IN KINEMATIC FORCING WOULD OTHERWISE
PRESENT DRY CONDITIONS TO THE AREA HEADING INTO THE DAY
THURSDAY...BUT SHORT TERM GUIDANCE SUGGESTS THE ~50KT MID LEVEL
JET STREAK TO OUR NORTHWEST WILL PUSH OVERHEAD TOMORROW...WITH A
DIRECT THERMAL CIRCULATION WITHIN THE RIGHT-REAR QUAD OF THIS JET
STREAK PERHAPS PROVIDING ENOUGH LIFT FOR ADDITIONAL PRECIPITATION
PRODUCTION DURING THE MORNING HOUR THURSDAY. WENT AHEAD WITH 20%
POPS ACROSS THE ENTIRE CWA THURSDAY MORNING AS A RESULT.

LOW LEVEL PRESSURE RISES POST-FROPA WILL CREATE A SIGNIFICANT
INCREASE IN THE LOW LEVEL PRESSURE GRADIENT FOR A BRIEF TIME THIS
EVENING...LIKELY RESULTING IN STRONG WINDS ACROSS PORTIONS OF OUR
CWA PRIMARILY DURING THE 00Z-09Z TIME FRAME. MET AND MAV GUIDANCE
BOTH SUGGEST WIND SPEEDS FOR A FEW LOCATIONS ACROSS THE CWA COULD
FLIRT WITH WIND ADVISORY CRITERIA FOR A TIME...BUT THESE STRONGEST
WINDS ARE EXPECTED TO REMAIN FAIRLY BRIEF AND SHOULD NOT REQUIRE
ANY HEADLINES THIS EVENING OR TONIGHT.

BCCONSRAW HAS BECOME ONE OF THE BETTER SETS OF GUIDANCE WITH
RESPECT TO OVERNIGHT LOWS THE PAST FEW DAYS AND THUS PLAYED
CLOSELY TO BCCONSRAW FOR OVERNIGHT LOWS TONIGHT. OVERNIGHT LOWS IN
THE 60S ARE FORECAST ACROSS MUCH OF THE CWA FOR TONIGHT AS A
RESULT. A MAJOR COOL DOWN IS IN STORE FOR THE AREA BEGINNING
TOMORROW AS A MUCH COOLER AIRMASS SETTLES INTO THE REGION.
STATISTICALLY...CONSMOS AND ADJMAVBC HAVE BEEN DOING VERY WELL
WITH DAY 1 HIGH TEMPERATURES...BUT THE ADJMAVBC LOOKED A LITTLE
WARM WITH HIGHS IN THE UPPER 70S TO LOWER 80S. WITH STRONG LOW
LEVEL COLD AIR ADVECTION...AS WELL AS LINGERING CLOUD COVER AND
POSSIBLE PRECIPITATION...WOULD MUCH RATHER KEEP DAY TIME
TEMPERATURE RISES TO AROUND 15 DEGREES ON THURSDAY...WHICH WOULD
PRESENT THURSDAY HIGHS IN THE MID TO UPPER 70S FOR THE MOST PART.
CONSMOS SEEMED TO HAVE A BETTER HANDLE ON THIS AND THUS WENT
CONSMOS FOR HIGHS ON THURSDAY.

LONG TERM...BEGINNING 00Z FRIDAY AND CONTINUING THROUGH
WEDNESDAY. MAIN CONCERNS FOR THIS PERIOD WILL BE TEMPERATURES AND
PRECIPITATION. FOG MAY BECOME AN ISSUE FRIDAY MORNING AS WELL.

STARTING WITH FRIDAY MORNING...LOW TEMPERATURES WILL BE THE
COOLEST LOWS OBSERVED THROUGHOUT THE LONG TERM AS TEMPERATURES
WILL BE 10 TO 15 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. A
STEADY INCREASE IN LOW TEMPERATURES EACH DAY WILL BE OBSERVED
THROUGH THE EXTENDED FORECAST...EVENTUALLY GETTING BACK TO NEAR
NORMAL LOW TEMPERATURES ON MONDAY. WENT WITH BCCONSRAW FOR FRIDAY
LOW TEMPS AND BCCONSALL FOR LOW TEMPS ON SATURDAY...BOTH CHANGES
INDUCED A SLIGHT LOWERING IN LOW TEMPERATURES FROM THE PREVIOUS
FORECAST. HIGH TEMPERATURES DURING THIS PERIOD WILL BEGIN BELOW
NORMAL AS WELL...WITH TEMPERATURES EVENTUALLY GETTING BACK TO
NORMAL ON MONDAY. WENT WITH THE PREVIOUS SHIFTS HIGH TEMPERATURES
FOR FRIDAY AND SATURDAY. ALLBLEND TOOK CARE OF THE FOLLOWING DAYS
WITH VERY REASONABLE OUTCOMES FOR BOTH LOW AND HIGH TEMPERATURES.

PRECIPITATION CHANCES WILL BEGIN AS EARLY AS FRIDAY EVENING AND
CONTINUE ON INTO SUNDAY MORNING AS A WEAK WAVE MOVES THROUGH THE
PLAINS. INITIALIZATION OF THE PRECIPITATION ACROSS SOUTHWESTERN
PARTS OF THE CWA FRIDAY EVENING ARE IN PRETTY GOOD AGREEMENT WITH
THE NAM12...GFS40...AND THE EC. SREF 6-HR QPF PROBABILITIES FOR
GREATER THAN 0.01 INCHES OF PRECIPITATION AT 00Z SATURDAY INDICATE
NEAR 50 PERCENT FOR NEARLY THE ENTIRE SOUTHWESTERN HALF OF THE
CWA. A LESS CLEAR PICTURE IS PAINTED AS DISAGREEMENT BETWEEN MODEL
OUTPUT WITH PRECIPITATION COVERAGE BECOMES EVIDENT LATER IN THE
DAY. LEANED MORE TOWARDS THE NAM SOLUTION FOR SATURDAY AND
ALLBLEND FOR SUNDAY MORNING. DEEP LAYER SHEAR AND SURFACE BASED
CAPE ARE WEAK...BUT LOW LEVEL SHEAR IS MODEST...WITH EARLY
AFTERNOON VALUES BETWEEN 15 AND 25 KTS/KM. THUNDERSTORMS ARE
POSSIBLE BUT SEVERE POTENTIAL IS VERY LIMITED AT THE MOMENT. THE
NEXT CHANCE FOR PRECIPITATION IS MONDAY EVENING LEADING INTO
TUESDAY MORNING...AND HAS BEEN THE CASE FOR PREVIOUS FORECAST
ACROSS THE CWA. THE GFS AND EC ARE IN PRETTY GOOD AGREEMENT FOR
PRECIPITATION ON TUESDAY MORNING. THUNDERSTORMS WILL BE POSSIBLE
WITH THIS SYSTEM ON TUESDAY.

SURFACE DEW POINT DEPRESSIONS WILL BE CLOSE TO 5 DEGREES OR LESS
FOR NORTHERN AND WESTERN PARTS OF THE CWA FRIDAY MORNING. MAY WANT
TO CONSIDER MONITORING FOG CONDITIONS TOMORROW EVENING AS THE
PICTURE BECOMES MORE CLEAR. MODELS ARE INDICATING A SURFACE HIGH
SITTING OVER THE NORTHERN/CENTRAL PLAINS...LIGHT WINDS ACROSS MUCH
OF THE OUTLOOK AREA FRIDAY MORNING...AND MOSTLY CLEAR SKIES WILL
HELP INDUCE FOG UNDER THESE CONDITIONS.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.

&&

$$








AREA FORECAST DISCUSSION

NWS ALBUQUERQUE NM

 323 PM MDT THU AUG 16 2012

.DISCUSSION...
DEFINITE INCREASE IN STORM STRENGTH AND COVERAGE TODAY AS EXPECTED
WITH SEVERAL FORCING MECHANISMS IN PLACE OVER THE STATE. CIRA BLENDED
PWAT IMAGERY SHOWING VALUES OF 100-125 PCT OF NORMAL. THE AXIS OF THE
H5 RIDGE IS POSITIONED FROM NORTHERN AZ SOUTHEAST ACROSS WEST CENTRAL
NM. H5 TEMPS OF -6 TO -7C ARE HELPING NOT TO CAP ANY CONVECTION AS
HAS BEEN THE CASE. WINDS ARE ALSO VERY WEAK ABOVE 700MB SO COMBINATION
OF HIGHER MOISTURE...COOLER TEMPS ALOFT...AND GOOD SURFACE HEATING WILL
ALLOW FOR LOCALLY HEAVY RAINFALL THRU THIS EVENING. THE HRRR AND RUC
MODELS INDICATE CONVECTION WILL ORGANIZE INTO THE MIDDLE RIO GRANDE
VALLEY SOUTHEASTWARD SO HAVE RAISED POPS TO HIGH CHANCE AND LIKELY.
DID NOT HAVE HIGH ENOUGH CONFIDENCE TO PLACE LOCALLY HEAVY RAINFALL
WORDING IN FORECAST FOR TONIGHT...AND FOR THAT MATTER THE NEXT FEW
DAYS...AS IT WILL BE HARD TO PINPOINT ANY SPECIFIC AREA FOR ENHANCED
THREAT.

THE H5 RIDGE AXIS WILL CHANGE LITTLE OVER THE NEXT FEW DAYS...SETTING
UP WEAK STEERING FLOW FOR CENTRAL AND WESTERN NM WHILE THE EAST ENJOYS
THE BENEFITS OF NW FLOW ALOFT. LIGHT UPSLOPE FLOW ACROSS THE PLAINS
ONTO THE EAST SLOPES BENEATH NW FLOW WILL BE FAVORABLE FOR POTENTIALLY
SOME OF BEST PRECIP SEEN IN QUITE SOME TIME. ANOTHER BACK DOOR FRONT
SUNDAY WILL JUST ENHANCE MOISTURE AND PRECIP CHANCES AGAIN. RAISED
POPS EVEN MORE TO THE HIGH CHANCE/LIKELY CATEGORY THRU THE WEEKEND.
TEMPS WILL BE MUCH CLOSER TO NORMAL AND EVEN A FEW DEGREES BELOW. GAP
WINDS ARE EXPECTED AGAIN IN THE RIO GRANDE VALLEY SATURDAY EVENING
INTO SUNDAY MORNING.

MODELS REMAIN AT ODDS BEYOND THE WEEKEND WITH HOW MUCH CONDITIONS WILL
DRY OUT. THE GFS HAS THE RIDGE SLIDING EAST AND CENTERING OVER CENTRAL
NM MONDAY THRU MOST OF NEXT WEEK...WHILE THE ECMWF KEEPS THE RIDGE TO
THE WEST AND FORCING MORE BACK DOOR FRONTS INTO THE AREA. GIVEN THE
PATTERN THIS SUMMER WILL BE FAVORING THE ECMWF AT THIS TIME...WHICH
WILL KEEP TEMPS NEAR NORMAL AND PRECIP CHANCES PERHAPS AT CLIMO FOR
LATE AUGUST. GUYER

&&

.FIRE WEATHER...
CRITICAL FIRE WEATHER...NOT EXPECTED THROUGH AT LEAST MIDWEEK NEXT
WEEK.

FCST MODELS REMAIN IN FAIRLY GOOD AGREEMENT ON GENERAL FCST PATTERN
THROUGH THE START TO MIDDLE OF NEXT WEEK. UPPER HIGH CENTER TO
CONTINUE TO MEANDER BACK AND FORTH GENERALLY BETWEEN NV AND AZ. THIS
WILL ALLOW FOR SOME WEAK TO MODERATE LOW LVL MOISTURE REPLENISHMENT
FROM THE E THROUGH S FROM TIME TO TIME WITH COMBINATION OF WESTBOUND
THROUGH NORTHBOUND OUTFLOWS FROM STORM COMPLEXES IN S AND E HALVES
OF THE STATE AS WELL AS CURRENT WEAKENING BACK DOOR FRONT VCNTY OF
RIO GRANDE VALLEY AS OF THIS WRITING AND ANOTHER ONE DUE INTO E AND
PERHAPS CENTRAL NM OVER THE WEEKEND.

SHOWERS AND STORMS THIS EVE AND OVERNIGHT TO BE MOST NUMEROUS...AND
WITH GOOD WETTING FOOTPRINTS...TO E OF THE CONTINENTAL DIVIDE WITH
MOST LIGHTNING OVER WITH BY OR NOT TOO LONGER AFTER MIDNIGHT...
ESPECIALLY HIGHER TERRAIN. GOOD TO EXCELLENT HUMIDITY RECOVERIES
OVERNIGHT.

FOR FRIDAY...ACTIVE CONVECTION EXPECTED ACROSS THE STATE...WITH
WETTING RAINS THE BEST BET AGAIN E OF DIVIDE. MINIMUM HUMIDITIES
INCREASING TO THE HIGH 20S TO THE MID 40S PCT RANGE OVER MUCH OF THE
STATE...WITH SOME HIGH TEENS AND 20S PCT REMAINING OVER THE DRYER
NORTHWEST QUADRANT. AGAIN GOOD TO EXCELLENT HUMIDITY RECOVERY
OVERNIGHT.

SATURDAY WILL BRING WEAK COLD FRONT INTO THE NORTHEAST PLAINS...
PROGRESSING TO THE S AND W LATER IN THE DAY THROUGH SUN AM. WETTING
RAINS MOST LIKELY ALONG AND E THROUGH N OF FRONTAL BOUNDARY. NW
PLATEAU STILL GETTING THE SHORT END OF THE STICK WITH REGARDS TO
CONVECTION AND WETTING RAIN. VERY GOOD TO EXCELLENT RECOVERIES
OVERNIGHT FOR ALL BUT THE NORTHWEST...WHERE RECOVERY WILL DROP BACK
INTO THE GOOD CATEGORY. FOR SUN THROUGH TUE THE UPPER HIGH AND RIDGE
STILL GENERALLY TO W OF NM. PRETTY GOOD CHANCES FOR WETTING RAINS
SUNDAY BUT BEGINNING A BIT OF A DOWNTURN MON AND TUE. AFTN TEMPS
SHOULD WARM A FEW DEGREES MOST AREAS BY MON OR TUE AND THIS WILL
LOWER MIN HUMIDITIES AND LESSEN OVERNIGHT RECOVERIES. 43

&&

.AVIATION...
18Z TAF CYCLE
BACK DOOR COLD FRONT AS OF MIDDAY LOCATED APPROX FROM WESTERN RIO
ARRIBA COUNTY THEN SOUTHWARD JUST TO THE WEST OF THE MIDDLE RIO
GRANDE VALLEY THEN INTO EASTERN SOCORRO COUNTY. THIS FRONT WILL NOT
LIKELY MOVE TOO MUCH FARTHER WEST THROUGH LATE AFTN...BUT SHOULD
MAKE IT TO OR A LITTLE WAYS EITHER SIDE OF THE CONTINENTAL DIVIDE
TONIGHT. THIS PATTERN WILL SET UP SCT TO AT TIMES NUMEROUS SHRA AND
TSRA COVERAGE LATE THIS AFTERNOON INTO TONIGHT. IN TAFS...VCTS SHOWS
MOST LIKELY EXPECTED TIME OF THUNDERSTORM ACTIVITY IN VCNTY OF SAID
AIRPORT. THE LATER VCSH GROUPS INDICATE REDUCED BUT NOT ZERO
LIGHTNING POTENTIAL AND SOME RAINFALL REMAINING IN VCNTY FOR ALL
POINTS. HEAVIER RAINFALL TODAY MAY DROP CIGS AND VSBY TO MVFR IN
HEAVIER TSTMS FOR RELATIVELY BRIEF PERIODS. TSRA DIMINISHING AFTER 4
OR 5Z OTHERWISE...VFR CONDITIONS AT ALL POINTS OVER THE NEXT 24
HOURS. 43

&&

.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON......................  68  94  63  93 /  10  10  10  10
DULCE...........................  52  87  51  87 /  20  30  20  20
CUBA............................  55  87  56  86 /  30  50  30  30
GALLUP..........................  60  88  58  88 /  20  30  20  10
EL MORRO........................  56  80  53  80 /  30  40  30  20
GRANTS..........................  57  83  52  85 /  30  40  30  20
QUEMADO.........................  56  81  56  85 /  40  40  30  30
GLENWOOD........................  60  88  56  86 /  50  40  40  20
CHAMA...........................  54  80  49  80 /  30  40  20  40
LOS ALAMOS......................  62  81  58  82 /  40  60  40  60
PECOS...........................  57  77  59  78 /  50  60  40  60
CERRO/QUESTA....................  57  79  51  80 /  40  50  30  60
RED RIVER.......................  48  72  45  72 /  50  60  30  60
ANGEL FIRE......................  48  74  46  74 /  50  60  40  60
TAOS............................  54  83  53  83 /  40  50  30  50
MORA............................  52  74  56  75 /  50  60  40  60
ESPANOLA........................  59  87  58  88 /  40  40  30  50
SANTA FE........................  62  81  59  82 /  50  50  30  60
SANTA FE AIRPORT................  63  85  61  85 /  40  50  30  50
ALBUQUERQUE FOOTHILLS...........  65  88  65  88 /  50  40  40  40
ALBUQUERQUE HEIGHTS.............  70  90  67  90 /  50  30  40  30
ALBUQUERQUE VALLEY..............  67  92  63  93 /  50  30  40  30
ALBUQUERQUE WEST MESA...........  69  91  65  92 /  40  30  40  30
LOS LUNAS.......................  66  90  62  91 /  50  30  40  30
RIO RANCHO......................  69  92  65  92 /  40  40  40  40
SOCORRO.........................  69  94  66  96 /  60  40  50  30
SANDIA PARK/CEDAR CREST.........  61  85  57  85 /  50  60  50  60
TIJERAS.........................  63  88  58  88 /  50  50  40  60
MORIARTY/ESTANCIA...............  60  82  57  82 /  60  60  50  60
CLINES CORNERS..................  59  81  60  81 /  50  60  50  60
GRAN QUIVIRA....................  61  83  62  84 /  60  50  50  60
CARRIZOZO.......................  63  86  64  86 /  40  40  50  50
RUIDOSO.........................  57  75  58  77 /  40  50  50  60
CAPULIN.........................  58  80  56  78 /  40  40  40  50
RATON...........................  59  88  60  86 /  40  50  40  50
SPRINGER........................  59  86  61  86 /  40  50  40  50
LAS VEGAS.......................  57  80  58  81 /  50  60  50  60
CLAYTON.........................  61  87  59  84 /  30  40  50  40
ROY.............................  64  82  64  85 /  40  50  50  50
CONCHAS.........................  68  90  67  92 /  30  50  50  50
SANTA ROSA......................  66  90  67  93 /  40  50  50  50
TUCUMCARI.......................  68  91  68  93 /  30  50  50  50
CLOVIS..........................  66  87  69  88 /  30  50  40  40
PORTALES........................  68  88  70  87 /  30  50  30  40
FORT SUMNER.....................  70  89  69  91 /  30  50  40  40
ROSWELL.........................  71  91  71  89 /  30  30  30  30
PICACHO.........................  64  84  62  83 /  30  40  30  50
ELK.............................  60  79  59  78 /  30  40  30  50

&&

.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

GUYER







AREA FORECAST DISCUSSION

NWS BUFFALO NY

 1059 AM EDT THU AUG 16 2012

.SYNOPSIS...
HIGH PRESSURE WILL BRING SUNNY AND WARM WEATHER TO WESTERN NEW YORK
TODAY. THEN A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT...
PRODUCING A BAND OF SHOWERS AND THUNDERSTORMS. FOLLOWING THE PASSAGE
OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS HUMID
CONDITIONS FOR THIS UPCOMING WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
FOR THE REST OF THE MORNING AND AFTERNOON HOURS...A COMBINATION OF
A WEAK LAKE BOUNDARY OVER EASTERN LAKE ONTARIO AND GENERAL
INSTABILITY OVER THE EASTERN LAKE ONTARIO REGION WILL BE ENOUGH TO
GENERATE SOME SHOWER ACTIVITY. WILL FOCUS ON AN AREA BETWEEN
WATERTOWN AND ROUTE 49 BASED ON SATELLITE IMAGERY AND WEAK
CONVERGENCE IN RUC ANALYSIS. HAVE UPDATED THE FORECASTS FOR THE
EASTERN LAKE ONTARIO REGION AND ISSUED A NOWCAST TO COVER THIS AS
EARLIER FORECASTS WERE FOCUSED ON LARGER SCALE FEATURES. SBCAPE IS
FORECAST TO LOWER WITH TIME...SO ANY ADDITIONAL SHOWERS THAT FORM
THIS MORNING OR EARLY AFTERNOON SHOULD FALL APART AND/OR HEAD INTO
THE ADIRONDACKS WITHOUT ADDITIONAL DEVELOPMENT LATER THIS
AFTERNOON AS THE TYPICAL SUMMER LAKE BREEZE SETS UP. GOT TO LOVE
THOSE LAKES...

A LARGE BUT WEAK AND ELEVATED MCS IS WORKING ITS WAY EASTWARD INTO
SW MI AND NORTHERN IL AT 14Z.  SATELLITE IR IMAGERY SHOWS WARMING
TOPS A LOWER CG STRIKES...INDICATING A WEAKENING TREND.  THIS
FEATURE IS WITHIN A NARROW WARM SECTOR AND AHEAD OF A COLD FRONT
THAT IS FORECAST TO SWEEP ACROSS NY LATER TONIGHT AND EARLY
FRIDAY.  LINEAR EXTRAPOLATION TAKES THIS FEATURE TO THE SOUTHWEST
CORNER OF THE STATE BEFORE SUNSET...AND MATCHES HRRR RUNS...THE
LATEST OF WHICH /11Z RUN/ ACTUALLY KEEPS CONVECTIVE ACTIVITY MAINLY
SOUTH OF THE STATE LINE...BUT STILL MUCH EARLIER OLDER MODEL RUNS.
WILL ADD A CHANCE OF CONVECTION INTO THE EVENING FORECAST FOR THE
EARLIER TIMING FOR AREAS SOUTH OF KBUF.

MOST OF THE GUIDANCE MISSES THE LEADING AREA OF CONVECTION AND
INSTEAD FOCUSES ON A LINE ASSOCIATED WITH THE MAIN COLD
FRONT...WHICH SHOULD NOT ARRIVE IN WESTERN NY UNTIL AROUND OR AFTER
MIDNIGHT AND THEN HEAD EAST INTO CENTRAL NY TOWARD DAYBREAK OR EARLY
FRIDAY.  TIMING IS POOR FOR SEVERE WEATHER WITH LOW AND GENERALLY
ELEVATED INSTABILITY...ALTHOUGH THE WARM BOUNDARY LAYER ABOVE LAKE
ERIE WATERS IS NOT WELL HANDLED BY MODEL DATA...WITH OVERNIGHT
CONVECTION OFTEN BLOSSOMING MUCH MORE QUICKLY AND SOMETIMES IN A
MORE ROBUST FASHION THAN MODEL INDICATIONS.  CAPE IS SKINNY AND
STRONGER WINDS ALOFT WILL HAVE A TOUGH TIME MIXING DOWN.  HOWEVER
WILL LEAVE WORDING NOTING GUSTY WINDS IN THE FORECAST. AM STILL NOT
CONFIDENT ENOUGH TO RAISE THE PROBABILITY OF MEASURABLE RAIN ANY
HIGHER THAN 60-70 PERCENT AS THE EXPECTED LINE STILL HAS YET TO
MATERIALIZE BEHIND THE CURRENT MCS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THIS PERIOD WILL BEGIN WITH A COLD FRONT ON OUR WESTERN DOORSTEP
FRIDAY MORNING...WITH THE SHORT TERM GUIDANCE IN GOOD AGREEMENT ON
THIS FEATURE THEN RAPIDLY PUSHING EAST AND EXITING INTO EASTERN NEW
YORK/WESTERN NEW ENGLAND BY EARLY TO MID FRIDAY AFTERNOON...OR A
LITTLE QUICKER THAN SEEN IN PREVIOUS RUNS.

IMMEDIATELY ALONG AND AHEAD OF THE BOUNDARY...THE COMBINATION OF LOW
LEVEL CONVERGENCE ALONG THE FRONT AND THE LEADING EDGE OF HEIGHT
FALLS ALOFT WILL HELP TO FORCE A RELATIVELY NARROW BUT FAIRLY
COHESIVE BAND OF SHOWERS...WITH PLENTY ENOUGH LIFT AND MOISTURE
AVAILABLE TO WARRANT A CONTINUATION OF HIGH LIKELY POPS. DESPITE THE
RELATIVELY UNFAVORABLE MORNING TIMING...THERE WILL ALSO BE AT LEAST
A MENTIONABLE CHANCE OF THUNDERSTORMS AS WELL GIVEN THE OVERALL
STRENGTH OF THE LIFT...AND THE POTENTIAL CONTRIBUTION OF MOISTURE/
INSTABILITY FROM THE WARM WATERS OF LAKES ERIE AND ONTARIO. WITH A
FAIRLY UNIDIRECTIONAL SOUTHWESTERLY FLOW ALOFT INCREASING TO 35-40
KTS BETWEEN 850 AND 700 MB...ANY STORMS THAT DO FORM WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY GUSTY WINDS...AND WILL THEREFORE
CONTINUE TO HIGHLIGHT THIS IN BOTH THE GRIDS/WORDED FORECAST AND HWO.

GIVEN THE TIMING OF THE FRONT...THE GREATEST LIKELIHOOD OF
CONVECTION WILL OCCUR DURING THE MORNING HOURS...WITH STRONG
COOL/DRY AIR ADVECTION AND SUBSIDENCE IN THE WAKE OF THE FRONT THEN
LEADING TO RAPIDLY IMPROVING CONDITIONS FOLLOWING ITS PASSAGE.
EXPECT MOSTLY SUNNY SKIES TO SPREAD ACROSS THE AREA FROM WEST TO
EAST BETWEEN MID MORNING AND MID FRIDAY AFTERNOON...WITH PRECIP
CHANCES ALSO PLUMMETING TO BELOW SLIGHT CHANCE. WITH DECENT MIXING
AND THE RETURN TO SUNSHINE FOLLOWING THE FRONT...850 MB TEMPS OF
+10C TO +13C SHOULD SUPPORT HIGHS IN THE MID 70S IN MOST
LOCATIONS...WITH PERHAPS A SLIGHT DROP-OFF IN TEMPS COMING DURING
THE MID AND LATE AFTERNOON HOURS AS THE COLD AIR ADVECTION REGIME
STRENGTHENS.

AFTER THAT...RELATIVELY QUIET AND COOLER WEATHER IS EXPECTED FOR THE
BALANCE OF THE PERIOD AS LARGE-SCALE UPPER TROUGHING SLOWLY DEEPENS
ACROSS THE GREAT LAKES AND NORTHEAST...WHILE SURFACE HIGH PRESSURE
AND DRIER AIR CONTINUES TO RIDGE NORTHEAST FROM THE OHIO VALLEY.
WHILE TEMPS ALOFT WILL CERTAINLY GET COLD ENOUGH /I.E. +7C TO +9C/
TO SUPPORT A LAKE RESPONSE DOWNWIND OF THE LAKES...THE RELATIVELY
DRY NATURE OF THE AIRMASS AND SHEARED NATURE OF THE LOW TO MID LEVEL
FLOW WILL LIKELY PREVENT MUCH MORE THAN JUST SOME INCREASED STRATOCU
DOWNWIND OF THE LAKES AT POINTS...AND MAINLY DURING NIGHTTIME/EARLY
MORNING PERIODS AT THAT. WITH THE MUCH COOLER AIRMASS ALOFT...TEMPS
WILL EASILY DROP TO BELOW NORMAL LEVELS...WITH DAYTIME HIGHS ON
SATURDAY FALLING BACK TO THE LOWER HALF OF THE 70S...AND NIGHTTIME
LOWS FRIDAY AND SATURDAY NIGHTS DROPPING INTO THE LOWER TO MID
50S...WITH SOME UPPER 40S EVEN POSSIBLE IN INTERIOR VALLEYS OF THE
SOUTHERN TIER.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY THROUGH TUESDAY...OUR REGION WILL REMAIN UNDER THE INFLUENCE
OF AN UPPER LOW THAT WILL ONLY SLOWLY MOVE FROM JAMES BAY TO NORTH
CENTRAL QUEBEC. A SERIES OF WEAK SHORTWAVES MIGRATING THROUGH
THE LARGER-SCALE UPPER TROUGH WILL ROTATE ACROSS THE REGION DURING
THIS PERIOD...THOUGH EXPECT NO MORE THAN A SLIGHT CHANCE OF
SHOWERS AS ONLY LIMITED AMOUNTS OF MOISTURE WILL BE AVAILABLE TO
THESE WAVES TO WORK WITH. WITH THE UPPER LEVEL TROUGH REMAINING
THE DOMINANT WEATHER FEATURE...EXPECT SOMEWHAT COOLER THAN NORMAL
BUT COMFORTABLE TEMPS TO ALSO CONTINUE THROUGH TUESDAY.

LATE IN THE PERIOD...THE MAIN UPPER LOW WILL FINALLY GET KICKED OUT
ACROSS LABRADOR AND INTO THE NORTH ATLANTIC...ALLOWING FOR A
FLATTENING QUASI-ZONAL FLOW TO SET UP ACROSS THE GREAT LAKES AND
NORTHEAST. THIS WILL BRING AN END TO THE VERY LOW-END SHOWER
CHANCES...AS WELL AS THE START OF A WARMING TREND AS A WARM AIR
ADVECTION REGIME DEVELOPS ALOFT.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS THIS AFTERNOON WITH HIGH PRESSURE IN PLACE.

FOR TONIGHT A FRONTAL BOUNDARY WILL APPROACH LATE THIS EVENING.
2000FT WINDS WILL INCREASE TO 35 TO 40 KTS FROM WEST TO EAST...BUT
WILL NOT MIX DOWN OVERNIGHT. THIS WILL RESULT IN LLWS...WHICH IS
FORECAST TO BEGIN AT AROUND 04Z AT BUF/IAG/JHW.

THE FRONT IS ALSO LIKELY TO BRING A ROUND OF SHOWERS TO TAF
LOCATIONS LATE TONIGHT. THERE MAY BE SOME THUNDERSTORMS AS
WELL...BUT WITH THESE EXPECTED TO BE SCATTERED IN NATURE...WILL
CARRY -SHRA IN TAFS.

OUTLOOK...
FRIDAY...A PERIOD OF SHOWERS/THUNDERSTORMS WITH ASSOCIATED
MVFR...OTHERWISE VFR.
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.

&&

.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA FOR
TODAY...WITH TYPICAL LAKE BREEZE DEVELOPMENT EXPECTED. TONIGHT AND
FRIDAY...A COLD FRONT WILL CROSS THE LOWER LAKES ALONG WITH THE
LIKELIHOOD OF ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS...SOME OF
WHICH COULD PRODUCE LOCALLY GUSTY WINDS. BEHIND THE FRONT...A BRISK
WESTERLY FLOW OF COOLER AIR WILL SET UP ACROSS LAKE ONTARIO ON
FRIDAY...WITH WINDS AND WAVES POTENTIALLY REACHING ADVISORY CRITERIA.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...APFFEL
NEAR TERM...APFFEL/ZAFF
SHORT TERM...JJR
LONG TERM...JJR/WOOD
AVIATION...APFFEL/ZAFF
MARINE...APFFEL








AREA FORECAST DISCUSSION

NWS BUFFALO NY

 1036 AM EDT THU AUG 16 2012

.SYNOPSIS...
HIGH PRESSURE WILL BRING SUNNY AND WARM WEATHER TO WESTERN NEW YORK
TODAY. THEN A COLD FRONT WILL MOVE THROUGH THE AREA LATE TONIGHT...
PRODUCING A BAND OF SHOWERS AND THUNDERSTORMS. FOLLOWING THE PASSAGE
OF THE COLD FRONT EXPECT COOLER TEMPERATURES AND LESS HUMID
CONDITIONS FOR THIS UPCOMING WEEKEND.

&&

.NEAR TERM /THROUGH TONIGHT/...
A LARGE BUT WEAK AND ELEVATED MCS IS WORKING ITS WAY EASTWARD INTO
SW MI AND NORTHERN IL AT 14Z.  SATELLITE IR IMAGERY SHOWS WARMING
TOPS A LOWER CG STRIKES...INDICATING A WEAKENING TREND.  THIS
FEATURE IS WITHIN A NARROW WARM SECTOR AND AHEAD OF A COLD FRONT
THAT IS FORECAST TO SWEEP ACROSS NY LATER TONIGHT AND EARLY
FRIDAY.  LINEAR EXTRAPOLATION TAKES THIS FEATURE TO THE SOUTHWEST
CORNER OF THE STATE BEFORE SUNSET...AND MATCHES HRRR RUNS...THE
LATEST OF WHICH /11Z RUN/ ACTUALLY KEEPS CONVECTIVE ACTIVITY MAINLY
SOUTH OF THE STATE LINE...BUT STILL MUCH EARLIER OLDER MODEL RUNS.
WILL ADD A CHANCE OF CONVECTION INTO THE EVENING FORECAST FOR THE
EARLIER TIMING FOR AREAS SOUTH OF KBUF.

MOST OF THE GUIDANCE MISSES THE LEADING AREA OF CONVECTION AND
INSTEAD FOCUSES ON A LINE ASSOCIATED WITH THE MAIN COLD
FRONT...WHICH SHOULD NOT ARRIVE IN WESTERN NY UNTIL AROUND OR AFTER
MIDNIGHT AND THEN HEAD EAST INTO CENTRAL NY TOWARD DAYBREAK OR EARLY
FRIDAY.  TIMING IS POOR FOR SEVERE WEATHER WITH LOW AND GENERALLY
ELEVATED INSTABILITY...ALTHOUGH THE WARM BOUNDARY LAYER ABOVE LAKE
ERIE WATERS IS NOT WELL HANDLED BY MODEL DATA...WITH OVERNIGHT
CONVECTION OFTEN BLOSSOMING MUCH MORE QUICKLY AND SOMETIMES IN A
MORE ROBUST FASHION THAN MODEL INDICATIONS.  CAPE IS SKINNY AND
STRONGER WINDS ALOFT WILL HAVE A TOUGH TIME MIXING DOWN.  HOWEVER
WILL LEAVE WORDING NOTING GUSTY WINDS IN THE FORECAST. AM STILL NOT
CONFIDENT ENOUGH TO RAISE THE PROBABILITY OF MEASURABLE RAIN ANY
HIGHER THAN 60-70 PERCENT AS THE EXPECTED LINE STILL HAS YET TO
MATERIALIZE BEHIND THE CURRENT MCS.

&&

.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
THIS PERIOD WILL BEGIN WITH A COLD FRONT ON OUR WESTERN DOORSTEP
FRIDAY MORNING...WITH THE SHORT TERM GUIDANCE IN GOOD AGREEMENT ON
THIS FEATURE THEN RAPIDLY PUSHING EAST AND EXITING INTO EASTERN NEW
YORK/WESTERN NEW ENGLAND BY EARLY TO MID FRIDAY AFTERNOON...OR A
LITTLE QUICKER THAN SEEN IN PREVIOUS RUNS.

IMMEDIATELY ALONG AND AHEAD OF THE BOUNDARY...THE COMBINATION OF LOW
LEVEL CONVERGENCE ALONG THE FRONT AND THE LEADING EDGE OF HEIGHT
FALLS ALOFT WILL HELP TO FORCE A RELATIVELY NARROW BUT FAIRLY
COHESIVE BAND OF SHOWERS...WITH PLENTY ENOUGH LIFT AND MOISTURE
AVAILABLE TO WARRANT A CONTINUATION OF HIGH LIKELY POPS. DESPITE THE
RELATIVELY UNFAVORABLE MORNING TIMING...THERE WILL ALSO BE AT LEAST
A MENTIONABLE CHANCE OF THUNDERSTORMS AS WELL GIVEN THE OVERALL
STRENGTH OF THE LIFT...AND THE POTENTIAL CONTRIBUTION OF MOISTURE/
INSTABILITY FROM THE WARM WATERS OF LAKES ERIE AND ONTARIO. WITH A
FAIRLY UNIDIRECTIONAL SOUTHWESTERLY FLOW ALOFT INCREASING TO 35-40
KTS BETWEEN 850 AND 700 MB...ANY STORMS THAT DO FORM WILL HAVE THE
POTENTIAL TO PRODUCE LOCALLY GUSTY WINDS...AND WILL THEREFORE
CONTINUE TO HIGHLIGHT THIS IN BOTH THE GRIDS/WORDED FORECAST AND HWO.

GIVEN THE TIMING OF THE FRONT...THE GREATEST LIKELIHOOD OF
CONVECTION WILL OCCUR DURING THE MORNING HOURS...WITH STRONG
COOL/DRY AIR ADVECTION AND SUBSIDENCE IN THE WAKE OF THE FRONT THEN
LEADING TO RAPIDLY IMPROVING CONDITIONS FOLLOWING ITS PASSAGE.
EXPECT MOSTLY SUNNY SKIES TO SPREAD ACROSS THE AREA FROM WEST TO
EAST BETWEEN MID MORNING AND MID FRIDAY AFTERNOON...WITH PRECIP
CHANCES ALSO PLUMMETING TO BELOW SLIGHT CHANCE. WITH DECENT MIXING
AND THE RETURN TO SUNSHINE FOLLOWING THE FRONT...850 MB TEMPS OF
+10C TO +13C SHOULD SUPPORT HIGHS IN THE MID 70S IN MOST
LOCATIONS...WITH PERHAPS A SLIGHT DROP-OFF IN TEMPS COMING DURING
THE MID AND LATE AFTERNOON HOURS AS THE COLD AIR ADVECTION REGIME
STRENGTHENS.

AFTER THAT...RELATIVELY QUIET AND COOLER WEATHER IS EXPECTED FOR THE
BALANCE OF THE PERIOD AS LARGE-SCALE UPPER TROUGHING SLOWLY DEEPENS
ACROSS THE GREAT LAKES AND NORTHEAST...WHILE SURFACE HIGH PRESSURE
AND DRIER AIR CONTINUES TO RIDGE NORTHEAST FROM THE OHIO VALLEY.
WHILE TEMPS ALOFT WILL CERTAINLY GET COLD ENOUGH /I.E. +7C TO +9C/
TO SUPPORT A LAKE RESPONSE DOWNWIND OF THE LAKES...THE RELATIVELY
DRY NATURE OF THE AIRMASS AND SHEARED NATURE OF THE LOW TO MID LEVEL
FLOW WILL LIKELY PREVENT MUCH MORE THAN JUST SOME INCREASED STRATOCU
DOWNWIND OF THE LAKES AT POINTS...AND MAINLY DURING NIGHTTIME/EARLY
MORNING PERIODS AT THAT. WITH THE MUCH COOLER AIRMASS ALOFT...TEMPS
WILL EASILY DROP TO BELOW NORMAL LEVELS...WITH DAYTIME HIGHS ON
SATURDAY FALLING BACK TO THE LOWER HALF OF THE 70S...AND NIGHTTIME
LOWS FRIDAY AND SATURDAY NIGHTS DROPPING INTO THE LOWER TO MID
50S...WITH SOME UPPER 40S EVEN POSSIBLE IN INTERIOR VALLEYS OF THE
SOUTHERN TIER.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
SUNDAY THROUGH TUESDAY...OUR REGION WILL REMAIN UNDER THE INFLUENCE
OF AN UPPER LOW THAT WILL ONLY SLOWLY MOVE FROM JAMES BAY TO NORTH
CENTRAL QUEBEC. A SERIES OF WEAK SHORTWAVES MIGRATING THROUGH
THE LARGER-SCALE UPPER TROUGH WILL ROTATE ACROSS THE REGION DURING
THIS PERIOD...THOUGH EXPECT NO MORE THAN A SLIGHT CHANCE OF
SHOWERS AS ONLY LIMITED AMOUNTS OF MOISTURE WILL BE AVAILABLE TO
THESE WAVES TO WORK WITH. WITH THE UPPER LEVEL TROUGH REMAINING
THE DOMINANT WEATHER FEATURE...EXPECT SOMEWHAT COOLER THAN NORMAL
BUT COMFORTABLE TEMPS TO ALSO CONTINUE THROUGH TUESDAY.

LATE IN THE PERIOD...THE MAIN UPPER LOW WILL FINALLY GET KICKED OUT
ACROSS LABRADOR AND INTO THE NORTH ATLANTIC...ALLOWING FOR A
FLATTENING QUASI-ZONAL FLOW TO SET UP ACROSS THE GREAT LAKES AND
NORTHEAST. THIS WILL BRING AN END TO THE VERY LOW-END SHOWER
CHANCES...AS WELL AS THE START OF A WARMING TREND AS A WARM AIR
ADVECTION REGIME DEVELOPS ALOFT.

&&

.AVIATION /15Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS THIS AFTERNOON WITH HIGH PRESSURE IN PLACE.

FOR TONIGHT A FRONTAL BOUNDARY WILL APPROACH LATE THIS EVENING.
2000FT WINDS WILL INCREASE TO 35 TO 40 KTS FROM WEST TO EAST...BUT
WILL NOT MIX DOWN OVERNIGHT. THIS WILL RESULT IN LLWS...WHICH IS
FORECAST TO BEGIN AT AROUND 04Z AT BUF/IAG/JHW.

THE FRONT IS ALSO LIKELY TO BRING A ROUND OF SHOWERS TO TAF
LOCATIONS LATE TONIGHT. THERE MAY BE SOME THUNDERSTORMS AS
WELL...BUT WITH THESE EXPECTED TO BE SCATTERED IN NATURE...WILL
CARRY -SHRA IN TAFS.

OUTLOOK...
FRIDAY...A PERIOD OF SHOWERS/THUNDERSTORMS WITH ASSOCIATED
MVFR...OTHERWISE VFR.
SATURDAY...POSSIBLE MVFR/IFR IN FOG EARLY OTHERWISE VFR.
SUNDAY...VFR.
MONDAY...CHANCE OF SHOWERS/TSTMS. MAINLY VFR.

&&

.MARINE...
WINDS AND WAVES WILL REMAIN BELOW SMALL CRAFT ADVISORY CRITERIA FOR
TODAY...WITH TYPICAL LAKE BREEZE DEVELOPMENT EXPECTED. TONIGHT AND
FRIDAY...A COLD FRONT WILL CROSS THE LOWER LAKES ALONG WITH THE
LIKELIHOOD OF ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS...SOME OF
WHICH COULD PRODUCE LOCALLY GUSTY WINDS. BEHIND THE FRONT...A BRISK
WESTERLY FLOW OF COOLER AIR WILL SET UP ACROSS LAKE ONTARIO ON
FRIDAY...WITH WINDS AND WAVES POTENTIALLY REACHING ADVISORY CRITERIA.

&&

.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...APFFEL
NEAR TERM...APFFEL/ZAFF
SHORT TERM...JJR
LONG TERM...JJR/WOOD
AVIATION...APFFEL/ZAFF
MARINE...APFFEL








AREA FORECAST DISCUSSION

NWS CLEVELAND OH

 328 PM EDT THU AUG 16 2012

.SYNOPSIS...
A COLD FRONT ACROSS THE WESTERN GREAT LAKES WILL MOVE EAST ACROSS
THE LOCAL AREA TONIGHT. THE FRONT WILL MOVE TO THE EAST COAST
FRIDAY ALLOWING HIGH PRESSURE TO BEGIN BUILDING OVER THE REGION
FROM THE WEST. THE HIGH IS EXPECTED TO LINGER OVER THE REGION
THROUGH THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
THE AREA OF SHOWERS MOVING TOWARD NW OH CONTINUES TO BREAK UP BUT
HAVE STARTED TO SEE SOME NEW DEVELOPMENT IN FAR NE OH ALONG A LAKE
BREEZE BOUNDARY. THESE TRENDS WILL LIKELY CONTINUE FOR THE
REMAINDER OF THE AFTERNOON WITH AN INCREASE IN ACTIVITY IN THE
EAST AND A DECREASE IN THE WEST. HRRR AND CONVECTIVE SREF CONTINUE
TO SHOW ANOTHER LINE OF STORMS DEVELOPING JUST TO THE WEST OF THE
AREA TOWARD 00Z AHEAD OF AN APPROACHING COLD FRONT. THIS IS THE
LINE THAT WILL LIKELY BRING PRECIP TO THE ENTIRE AREA OVERNIGHT.
WILL CONTINUE WITH CATAGORICAL PRECIP CHANCES WITH MOST AREAS
SEEING UP TO A HALF INCH OF RAINFALL. THE PRECIP WILL END FROM
WEST TO EAST AFTER MIDNIGHT AS THE FRONT PULLS OUT. THICK CLOUDS
HAVE OVERSPREAD THE AREA AND THE THREAT FOR SEVERE WEATHER APPEARS
MINIMAL. BETTER INSTABILITY REMAINS TO THE SW AND THAT IS WHERE
ANY SEVERE WEATHER WILL LIKELY OCCUR.

&&

.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY NIGHT/...
THE COLD FRONT WILL BE GONE BY DAYBREAK AND MOST OF THE PRECIP
ALONG WITH IT. COULD SEE SOME SHOWERS IN THE EAST AND SOUTH
THROUGH MIDDAY BUT AFTER THAT IT SHOULD BE TOO DRY FOR MORE
PRECIP. 850 MB TEMPS WILL DIP TO AROUND PLUS 8 BY FRIDAY EVENING
SO THIS WILL BE A COLD AIRMASS. WILL LIKELY SEE A FAIR AMOUNT OF
LAKE EFFECT STATO CU THROUGH SATURDAY. SOME INDICATION FROM THE
MODELS OF ANOTHER WEAK FRONT APPROACHING FROM THE NORTH LATE
SUNDAY AND SUNDAY NIGHT. WILL GO WITH A VERY SMALL MENTION OF
SHOWERS IN THE FAR NORTH BUT REALLY DON`T THINK THIS WILL BE A BIG
DEAL. TEMPS WILL AVERAGE WELL BELOW NORMAL AND LATER SHIFTS WILL
HAVE TO WATCH FOR POSSIBLE 40S FOR LOWS SUNDAY MORNING. HAVE USED
A BLEND OF GUIDANCE DURING THE PERIOD.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
INITIALLY LONG RANGE PART OF FORECAST SHOULD START OFF COOL AND
SOMEWHAT CLOUD. THE BIG QUESTION IS WHETHER THE UPPER TROF OVER THE
AREA WILL CAUSE ENOUGH FORCING TO PRODUCE A FEW SHRA...ESPECIALLY IN
THE SNOWBELT OR WHETHER SURFACE HIGH PRESSURE WILL KEEP THINGS DRY.
PREFERENCE IS TO CARRY AT LEAST A SLIGHT CHANCE FOR THE NE PART OF
THE AREA MON THEN GO DRY TUE AS THE UPPER TROF WEAKENS AND SHIFT
EAST.

WED LOOKS DRY AS TEMPS WARM BACK TO NORMAL. THE MODELS DIFFER BY THU
SO MUCH GREATER UNCERTAINTY IN OVERALL FORECAST. THUS FORECAST WILL
LARGELY BE INFLUENCED BY BEST COLLABORATION WITH SURROUNDING WFO`S.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
MODELS REMAIN ON TRACK IN MOVING A COLD FRONT ACROSS THE TAF SITES
TONIGHT. PROBLEM IS THAT CURRENT BAND OF CONVECTION WITH THE FRONT
IS AHEAD OF MODEL PROJECTIONS THUS LEADING TO AN ISSUE WITH MODEL
TIMING. WILL USE BLEND OF CURRENT RADAR INFO WITH MODELS TO TIME
TSRA EAST ACROSS THE AREA. EMPHASIS WILL BE ON CURRENT RADAR FOR
WESTERN TAF SITES WITH EMPHASIS GRADUALLY SHIFTING MORE TO MODELS
FOR TAF SITES FURTHER TO THE EAST.

EXPECT SOME FOG TO OCCUR LATER TONIGHT AFTER THE RAIN BUT CLOUD
COVER AND WNW FLOW OF 5 TO 8 KNOTS SHOULD KEEP FOG MOSTLY IN THE
MVFR RANGE. FOG AND CIGS IMPROVE FRI MORNING ALTHOUGH SOME MVFR MAY
LINGER IN THE EAST THROUGH 18Z AS SOME LAKE ENHANCEMENT WILL LIKELY
TAKE PLACE. A FEW SHRA MAY ALSO LINGER AT CAK...YNG AND ERI UNTIL
MIDDAY FRI.

.OUTLOOK...MAINLY VFR SHOULD PREVAIL BUT PATCHES OF LAKE EFFECT MVFR
CLOUDS MAY BE PRESENT SAT INTO MON...ESPECIALLY AROUND THE SNOWBELT.

&&

.MARINE...
COLD FRONT WILL MOVE INTO THE CENTRAL GREAT LAKES TONIGHT. EXPECT TO
SEE SOUTHWEST WINDS TO REMAIN IN THE 10 TO 20 KNOT RANGE. HOWEVER
THE EASTERN HALF OF THE LAKE COULD SEE SLIGHTLY HIGHER FOR A COUPLE
HOURS JUST AHEAD OF THE FRONT AFTER MIDNIGHT. WILL THEN AWAIT THE
WIND SHIFT TO CLEAR LAKE ERIE NEAR OR SHORTLY AFTER SUNRISE.
NORTHWESTERLY WINDS MAY BE JUST STRONG ENOUGH WITH THE LONGER FETCH
TO PROVIDE SMALL CRAFT CONDITIONS FOR THE EASTERN HALF TO TWO THIRDS
OF THE LAKE INTO FRIDAY AFTERNOON. WILL LET THE NEXT SHIFT MONITOR
THIS POTENTIAL OVERNIGHT TO DECIDE IF WE WILL REACH THE CRITERIA.

HIGH PRESSURE WILL THEN CONTROL THE LAKE WITH A LIGHT WEST TO
NORTHWEST WIND EXPECTED THROUGH THE WEEKEND. SOUTHWESTERLY WINDS
SHOULD RETURN BY MONDAY AFTERNOON AND SHOULD PERSIST INTO TUESDAY
AHEAD OF THE NEXT COLD FRONT.

&&

.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...KUBINA
NEAR TERM...KUBINA
SHORT TERM...KUBINA
LONG TERM...ADAMS
AVIATION...
MARINE...MULLEN







AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 309 PM EDT THU AUG 16 2012

.SYNOPSIS...
STRONG COLD FRONT CROSSES TOMORROW. WEAK HIGH
PRESSURE OVER WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY.
ANOTHER HIGH PRESSURE BUILDS NEXT WEEK

&&

.NEAR TERM /THROUGH FRIDAY/...
MORNING COMPLEX CONT TO WEAKEN AS IT RUNS IN TO DRY AIR IN MID
LVLS AND AWAY FROM COLD FRONT/UPR SUPPORT. RUC AND RAP DO INDICATE
A SLIGHT MOISTENING ACROSS PERRY/MORGAN 22-00Z WHICH MAY BE ENOUGH
FOR AN ISO SHRA/TSRA AS REMNANTS...AT LEAST ALOFT...MOVE ACROSS E
OH. THUS ELECTED TO CODE UP SCHC ACROSS PERRY DURING
AFOREMENTIONED TIME FRAME.

OTHERWISE WILL BE WAITING FOR APPROACH OF UPR TROF AND ASSOCIATED
SFC FRONT HEADING INTO TOMORROW. LIKED TIMING OF PREV FCST WHICH
IS IN GOOD AGREEMENT WITH NAM. LOOKS LIKE AREA WILL BE DEALING
WITH TWO POSSIBLE BANDS OF PCPN...PREFRONTAL BAND IN THE MORNING
FOLLOWED BY A ROUND OF CONVECTION MORE WITH ACTUAL FRONT. HAVE SFC
FRONT JUST ENTERING SE OH AT 12Z WITH PREFRONTAL BAND HAVING
TRAVERSED THRU SE OH/NE KY INTO CENTRAL WV...AIDED MORE BY DECENT
OMEGA ARND H7 AND LLVL WAA. EXPECT THIS TO FIZZLE OUT AS IT HEADS
INTO MTNS BY MID MORNING. WILL KEEP THUNDER IN GIVEN ELEVATED
INSTABILITY. MEANWHILE FRONT MAY SLOW DOWN BRIEFLY TOMORROW WITH
ANOTHER ORGANIZED BAND OF INITIALLY FRONTAL CONVECTION MOVING
ACROSS THE AREA AFTER A BRIEF BREAK FOLLOWING MORNING CONVECTION.
THIS LOOKS TO PROPAGATE OUT AHEAD OF BOUNDARY IN AFTN AND EXIT
MTNS BY 21Z AS DEEPER MOISTURE IS EXODUS. WILL HANG SOME LOW POPS
BACK A FEW HRS WITH SFC FRONT ONLY CROSSING OH RVR BY SAID TIME.

WILL GO WITH HIGHER NUMBERS TONIGHT WITH BL FLOW INCREASING LATE.
HIGHS TOMORROW TRICKY. WILL LEAN TOWARD LOWER NUMBERS FROM
GUIDANCE.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
COLD FRONT EXPECTED TO BE EXIT THE EASTERN MOUNTAINS AT THE
BEGINNING OF THE PERIOD WITH PCPN DECREASING FROM CHANCE TO SLIGHT
CHANCE THROUGH 12Z SATURDAY. DEWPOINTS WILL LINGER INTO THE LOWER
60S EXTREME NORTHEAST...UPPER TO MID 50S EAST OF THE OH
RIVER...DROPPING TO THE LOW 50S ACROSS SOUTHEAST OH BY SATURDAY
MORNING.

HIGH PRESSURE BUILDS BEHIND THE FRONT WITH DRIER AIR TO PROVIDE
PLENTY OF SUNSHINE SATURDAY. WITH ABUNDANT LINGERING MOISTURE OVER
THE EASTERN MOUNTAINS...KEPT SLIGHT CHANCE FOR AFTERNOON SHOWERS.

WITH THE EXPECTED WIDESPREAD CLEARING SATURDAY AND SUNDAY
NIGHTS...DENSE FOG IS A GOOD BET OVER AREAS THAT RECEIVE RAIN AND
ALONG RIVER VALLEYS DUE TO NEAR CLAM FLOW.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
HIGH PRESSURE STRENGTHENS THROUGH MID WEEK PROVIDING MOSTLY CLEAR
SKIES AND NORMAL TEMPERATURES. HOWEVER...THE GFS SUGGEST UPPER LEVEL
SYNOPTIC LIFT ASSOCIATED WITH AND UPPER LEVEL JET...ALTHOUGH
MOISTURE IS LIMITED PER PWATS AROUND 0.75 INCHES...FEW SHOWERS COULD
DEVELOP ONCE AGAIN OVER THE EASTERN MOUNTAINS SUNDAY AFTERNOON.

OTHERWISE...DRY WEATHER AND PLEASANT TEMPERATURES WILL PREVAIL
THROUGH THE END OF THE WEEK.

SOME WARM AIR ADVECTION NOTICED AT H850 FROM 11C TO 14-16C FROM
THE GFS/ECMWF UNDER WEAK SOUTHERLY FLOW FROM WED THROUGH THE END
OF THE WEEK. THEREFORE...INCREASED TEMPS TO THE MID TO UPPER 80S
SIMILAR TO HPC AND GMOS FROM WEDNESDAY THROUGH END OF THE PERIOD.

USED HPC TEMPS...WITH SOME TWEAKS DAY 5 THROUGH DAY 7.

&&

.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
VFR CONDITIONS PREVAIL INTO MUCH OF THE NIGHT. WITH BL FLOW
INCREASING MVFR/IFR FG SHOULD BE MITIGATED TO MTN VALLEYS AND HAVE
KEKN IN IFR FG BY 06Z BEFORE PERHAPS IMPROVING BY DAWN. OTHERWISE
SOME MID AND HI CLDS INCREASE LATE TONIGHT FROM W TO E WITH
PREFRONTAL CONVECTIVE PCPN MOVING ACROSS SE OH INTO CENTRAL WV BY
12Z. WILL CARRY MVFR VSBY IN SHRA WITH VCTS AT THIS DISTANCE. COLD
FRONT ENTERS SE OH ARND 12Z...TAKING MUCH OF THE DAYLIGHT HRS TO
CROSS OH RVR WITH ANOTHER ROUND OF CONVECTION ASSOCIATED WITH
FRONT PUSHING ACROSS LATE MORNING THRU AFTN WITH LCL IFR
CONDITIONS EXPECTED.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...

FORECAST CONFIDENCE: HIGH.

ALTERNATE SCENARIOS: EXTENT OF FG MAY BE GREATER THAN FCST SHOULD
CLOUDS AND INCREASE IN FLOW IS DELAYED. ARRIVAL OF PRECIPITATION
EARLY FRI MORNING MAY ALSO VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z FRIDAY...
IFR POSSIBLE IN THUNDERSTORMS FRI AND IN LOW CLOUDS AND / OR FOG SAT
MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...ARJ
LONG TERM...ARJ
AVIATION...30









AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 220 PM EDT THU AUG 16 2012

.SYNOPSIS...
STRONG COLD FRONT CROSSES TOMORROW. WEAK HIGH
PRESSURE OVER WEEKEND...WITH DISTURBANCE ALOFT PASSING SUNDAY.

&&

.NEAR TERM /THROUGH FRIDAY/...
MORNING COMPLEX CONT TO WEAKEN AS IT RUNS IN TO DRY AIR IN MID
LVLS AND AWAY FROM COLD FRONT/UPR SUPPORT. RUC AND RAP DO INDICATE
A SLIGHT MOISTENING ACROSS PERRY/MORGAN 22-00Z WHICH MAY BE ENOUGH
FOR AN ISO SHRA/TSRA AS REMNANTS...AT LEAST ALOFT...MOVE ACROSS E
OH. THUS ELECTED TO CODE UP SCHC ACROSS PERRY DURING
AFOREMENTIONED TIME FRAME.

OTHERWISE WILL BE WAITING FOR APPROACH OF UPR TROF AND ASSOCIATED
SFC FRONT HEADING INTO TOMORROW. LIKED TIMING OF PREV FCST WHICH
IS IN GOOD AGREEMENT WITH NAM. LOOKS LIKE AREA WILL BE DEALING
WITH TWO POSSIBLE BANDS OF PCPN...PREFRONTAL BAND IN THE MORNING
FOLLOWED BY A ROUND OF CONVECTION MORE WITH ACTUAL FRONT. HAVE SFC
FRONT JUST ENTERING SE OH AT 12Z WITH PREFRONTAL BAND HAVING
TRAVERSED THRU SE OH/NE KY INTO CENTRAL WV...AIDED MORE BY DECENT
OMEGA ARND H7 AND LLVL WAA. EXPECT THIS TO FIZZLE OUT AS IT HEADS
INTO MTNS BY MID MORNING. WILL KEEP THUNDER IN GIVEN ELEVATED
INSTABILITY. MEANWHILE FRONT MAY SLOW DOWN BRIEFLY TOMORROW WITH
ANOTHER ORGANIZED BAND OF INITIALLY FRONTAL CONVECTION MOVING
ACROSS THE AREA AFTER A BRIEF BREAK FOLLOWING MORNING CONVECTION.
THIS LOOKS TO PROPAGATE OUT AHEAD OF BOUNDARY IN AFTN AND EXIT
MTNS BY 21Z AS DEEPER MOISTURE IS EXODUS. WILL HANG SOME LOW POPS
BACK A FEW HRS WITH SFC FRONT ONLY CROSSING OH RVR BY SAID TIME.

WILL GO WITH HIGHER NUMBERS TONIGHT WITH BL FLOW INCREASING LATE.
HIGHS TOMORROW TRICKY. WILL LEAN TOWARD LOWER NUMBERS FROM
GUIDANCE.

&&

.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
THE 00Z NAM WAS THE SLOWEST WITH THE FRONTAL DEEP MOISTURE...THE GFS
APPEARS TO THE THE QUICKEST.  THE 12Z ECMWF WAS A NICE COMPROMISE.
ALL MODELS SHOW THE RIGHT REAR OF A 250 MB JET MAX HELPING THE
SYNOPTIC FORCING CENTERED ON 18Z FRIDAY.  WITH THAT IN MIND...LIKE
HPC DAY 2 QPF GOING WETTER...AND WETTER THAN THE 00Z GFS.

BASING THE FORECAST ON THE FRONT NOT PASSING CRW UNTIL ABOUT 00Z
SATURDAY. SO WAS A BIT SLOWER DRYING OUT/LOWERING POPS/IN OUR
SOUTHERN COAL FIELDS AND SOUTHERN MOUNTAINS SATURDAY EVENING.

HARD TO GET ANY GOOD HANDLE ON AMOUNT OF BREAKS IN THE CLOUDS...AND
THE INCREASE IN INSTABILITY FOR FRIDAY AFTERNOON. BUT SOUTHERN AND
EASTERN COUNTIES HAVE BEST CHANCE ON MORE INSTABILITY. STEERING FLOW
ABOUT 30 KNOTS ACROSS THE NORTH AND 25 KNOTS FURTHER SOUTH.

HOPE ANY CONVECTIVE CLUSTERS DO NOT BEND OVER TO A MORE EAST/WEST
ORIENTATION IN OUR SOUTHERN COUNTIES...AND THUS INCREASE CHANCE
FOR REPETITIVE ACTION...BY LATE FRIDAY AFTERNOON OR EARLY FRIDAY
EVENING.

FIGURING ON SOME LOW CLOUDS...MAYBE FOG SATURDAY MORNING MAINLY
EKN-CRW ON SOUTH...BUT TOO EARLY TO INSERT FOG INTENSITY. LOWERING
DEW POINTS REACH FURTHER SOUTH SATURDAY AFTERNOON.

LIKELY A SHARP CLOUD AND POP GRADIENT FROM SE TO NW SUNDAY MORNING
WITH DISTURBANCE ALOFT...INCREASING THE DEEPER MOISTURE TO OUR SOUTH
AND EAST.  DID INCLUDE SOME CHANCE POPS IN OUR MOUNTAINOUS COUNTIES
LEAVING THE WESTERN LOWLANDS DRY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
USED PREEPD THINKING FOR THIS PORTION OF THE FORECAST. REGION
SHOULD BE UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE...WITH AN
UPPER LEVEL TROF EXPECTED TO MOVE EAST ON TUESDAY.

THIS SHOULD RESULT IN MAINLY DRY WEATHER.  HOWEVER...WITH UPPER
LEVEL TROF PUSHING EAST...HAVE GONE WITH DIURNAL SLIGHT CHANCE POPS
ACROSS OUR HIGHER ELEVATIONS.

USED HPC TEMPS WITH SOME TWEAKS.

&&

.AVIATION /17Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS PREVAIL INTO MUCH OF THE NIGHT. WITH BL FLOW
INCREASING MVFR/IFR FG SHOULD BE MITIGATED TO MTN VALLEYS AND HAVE
KEKN IN IFR FG BY 06Z BEFORE PERHAPS IMPROVING BY DAWN. OTHERWISE
SOME MID AND HI CLDS INCREASE LATE TONIGHT FROM W TO E WITH
PREFRONTAL CONVECTIVE PCPN MOVING ACROSS SE OH INTO CENTRAL WV BY
12Z. WILL CARRY MVFR VSBY IN SHRA WITH VCTS AT THIS DISTANCE. COLD
FRONT ENTERS SE OH ARND 12Z...TAKING MUCH OF THE DAYLIGHT HRS TO
CROSS OH RVR WITH ANOTHER ROUND OF CONVECTION ASSOCIATED WITH
FRONT PUSHING ACROSS LATE MORNING THRU AFTN WITH LCL IFR
CONDITIONS EXPECTED.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z FRIDAY...

FORECAST CONFIDENCE: HIGH.

ALTERNATE SCENARIOS: EXTENT OF FG MAY BE GREATER THAN FCST SHOULD
CLOUDS AND INCREASE IN FLOW IS DELAYED. ARRIVAL OF PRECIPITATION
EARLY FRI MORNING MAY ALSO VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       18   19   20   21   22   23   00   01   02   03   04   05
EDT 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H

AFTER 18Z FRIDAY...
IFR POSSIBLE IN THUNDERSTORMS FRI AND IN LOW CLOUDS AND / OR FOG SAT
MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...ARJ/30
NEAR TERM...30
SHORT TERM...KTB
LONG TERM...JSH
AVIATION...30









AREA FORECAST DISCUSSION

NWS CHARLESTON WV

 1020 AM EDT THU AUG 16 2012

.SYNOPSIS...
HIGH PRESSURE PUSHES EAST THIS AFTERNOON. STRONG COLD FRONT CROSSES
FRIDAY AND FRIDAY EVENING. WEAK HIGH PRESSURE OVER WEEKEND...WITH
DISTURBANCE ALOFT PASSING SUNDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
1000AM UPDATE...
FOG/LOW STRATUS HANGING TOUGH ACROSS MTN VALLEYS AND S COAL FIELDS
THIS MORNING. THIS WILL LIFT AND SCT OUT NEXT HR OR SO.
OTHERWISE...WATCHING COMPLEX ASSOCIATED WITH COLD FRONT ACROSS N
IL THIS MORNING. MDLS ARE STRUGGLING WITH THIS CONVECTION TO SAY
THE LEAST. LATEST HRRR SEEMS TO BE CLOSE WITH INITIALIZATION BUT
THEN STRUGGLES WITH TIMING OF EASTERN PROGRESSION AS DAY WEARS ON.
ROUGH TIMING FROM SATELLITE/LIGHTNING STRIKES PUTS IN ON NW
FLANK ARND 21Z. HOWEVER...THINK THIS WILL CONTINUE TO WEAKEN THIS
MORNING BEFORE PERHAPS REFIRING THIS AFTN CLOSER TO FRONT. WILL
LEAVE POPS OUT ATTM ACROSS SE OH FOR LATE THIS AFTN GIVEN DRY AIR
ARND H7 AND MUCH OF SUPPORT REMAINING WELL WEST CLOSER TO FRONT
AND UPR SUPPORT. TRENDS WILL BE MONITORED THOUGH FOR SOME
INCLUSION OF LOW POPS ACROSS SE OH LATE.

PREVIOUS DISCUSSION BELOW...
LIGHT SW FLOW ON THE BACK SIDE OF HIGH PRESSURE EXITING STAGE E
WILL GIVE RISE TO A DRY DAY WITH SUNSHINE ONCE THE DENSE MORNING
FOG BURNS OFF...WITH A WARMER AFTERNOON.

A COLD FRONT AND UPPER LEVEL TROUGH APPROACHES FROM THE W TONIGHT.
THE ONSET OF THE PRECIPITATION IS LIKELY TO COINCIDE WITH THE
LEADING EDGE OF THE THETA E RIDGE AND UPPER LEVEL FORCING.  USED A
BLEND OF THE SLOWER SREF / GFS TIMING AND THE FASTER NAM12
TIMING...WHICH TAKES IT TO THE W EDGE OF THE CWA NEAR 06Z...THE OHIO
RIVER AT 09Z AND TO VERY NEAR THE MOUNTAINS 12Z FRI.  HAVE THE
CHANCE FOR THUNDER GIVEN ELEVATED INSTABILITY OVER TOP OF THE
STRAIGHT UP STABILITY GRADIENT.

TEMPERATURES AND DEW POINTS LOOKED TO BE CLOSE TO GUIDANCE WITH NO
MAJOR CHANGES NEEDED...ALTHOUGH THERE MAY BE A SMALL RISE W AND ON
THE RIDGES TOWARD DAYBREAK IN THE INCREASINGLY MOIST SW FLOW AHEAD
OF THE COLD FRONT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...
THE 00Z NAM WAS THE SLOWEST WITH THE FRONTAL DEEP MOISTURE...THE GFS
APPEARS TO THE THE QUICKEST.  THE 12Z ECMWF WAS A NICE COMPROMISE.
ALL MODELS SHOW THE RIGHT REAR OF A 250 MB JET MAX HELPING THE
SYNOPTIC FORCING CENTERED ON 18Z FRIDAY.  WITH THAT IN MIND...LIKE
HPC DAY 2 QPF GOING WETTER...AND WETTER THAN THE 00Z GFS.

BASING THE FORECAST ON THE FRONT NOT PASSING CRW UNTIL ABOUT 00Z
SATURDAY. SO WAS A BIT SLOWER DRYING OUT/LOWERING POPS/IN OUR
SOUTHERN COAL FIELDS AND SOUTHERN MOUNTAINS SATURDAY EVENING.

HARD TO GET ANY GOOD HANDLE ON AMOUNT OF BREAKS IN THE CLOUDS...AND
THE INCREASE IN INSTABILITY FOR FRIDAY AFTERNOON. BUT SOUTHERN AND
EASTERN COUNTIES HAVE BEST CHANCE ON MORE INSTABILITY. STEERING FLOW
ABOUT 30 KNOTS ACROSS THE NORTH AND 25 KNOTS FURTHER SOUTH.

HOPE ANY CONVECTIVE CLUSTERS DO NOT BEND OVER TO A MORE EAST/WEST
ORIENTATION IN OUR SOUTHERN COUNTIES...AND THUS INCREASE CHANCE
FOR REPETITIVE ACTION...BY LATE FRIDAY AFTERNOON OR EARLY FRIDAY
EVENING.

FIGURING ON SOME LOW CLOUDS...MAYBE FOG SATURDAY MORNING MAINLY
EKN-CRW ON SOUTH...BUT TOO EARLY TO INSERT FOG INTENSITY. LOWERING
DEW POINTS REACH FURTHER SOUTH SATURDAY AFTERNOON.

LIKELY A SHARP CLOUD AND POP GRADIENT FROM SE TO NW SUNDAY MORNING
WITH DISTURBANCE ALOFT...INCREASING THE DEEPER MOISTURE TO OUR SOUTH
AND EAST.  DID INCLUDE SOME CHANCE POPS IN OUR MOUNTAINOUS COUNTIES
LEAVING THE WESTERN LOWLANDS DRY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
USED PREEPD THINKING FOR THIS PORTION OF THE FORECAST. REGION
SHOULD BE UNDER THE INFLUENCE OF SURFACE HIGH PRESSURE...WITH AN
UPPER LEVEL TROF EXPECTED TO MOVE EAST ON TUESDAY.

THIS SHOULD RESULT IN MAINLY DRY WEATHER.  HOWEVER...WITH UPPER
LEVEL TROF PUSHING EAST...HAVE GONE WITH DIURNAL SLIGHT CHANCE POPS
ACROSS OUR HIGHER ELEVATIONS.

USED HPC TEMPS WITH SOME TWEAKS.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
VFR DAY TODAY ONCE THE FOG...MAINLY IN THE VALLEYS OF EASTERN WV...
BURNS OFF FIRST THING THIS MORNING.  SOME OF IT WILL MIX INTO LOW
CLOUDS THAT WILL THEN QUICKLY SCATTER OUT.  HIGH PRESSURE MOVES OFF
TO THE E TODAY...AND CLOUDS INCREASE FROM THE W TONIGHT AS A COLD
FRONT APPROACHES FROM THE W.

SHOWERS AND THUNDERSTORMS ARE LIKELY TO CROSS THE OHIO RIVER BY THE
END OF THE TAF PERIOD...WITH CONDITIONS GETTING DOWN TO AT LEAST VFR
THERE.  THE PRECIPITATION MAY MAKE IT AS FAR E AS CRW BY 12Z FRI.
MVFR MIST POSSIBLE IN THE MOUNTAIN VALLEYS OVERNIGHT TONIGHT BEFORE
THE CLOUDS MOVE IN.

SFC FLOW WILL BE LIGHT SW TODAY AND TONIGHT WHILE LIGHT W FLOW ALOFT
THIS MORNING BECOMES LIGHT TO MODERATE W TO SW FOR THIS AFTERNOON
AND TONIGHT.

FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z FRIDAY...

FORECAST CONFIDENCE: HIGH.

ALTERNATE SCENARIOS: FOG LIFTING AND MIXING OUT THIS MORNING MAY
VARY FROM TAF CODE.  ARRIVAL OF PRECIPITATION EARLY FRI MORNING MAY
ALSO VARY.

EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH:   TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW:    TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.

UTC 1HRLY       14   15   16   17   18   19   20   21   22   23   00   01
EDT 1HRLY       10   11   12   13   14   15   16   17   18   19   20   21
CRW CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
HTS CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
BKW CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H
EKN CONSISTENCY  H    H    H    H    H    H    H    H    H    H    H    H
PKB CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H
CKB CONSISTENCY  M    H    H    H    H    H    H    H    H    H    H    H

AFTER 12Z FRIDAY...
IFR POSSIBLE IN THUNDERSTORMS FRI AND IN LOW CLOUDS AND / OR FOG SAT
MORNING.

&&

.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.

&&

$$
SYNOPSIS...KTB/TRM
NEAR TERM...TRM/30
SHORT TERM...KTB
LONG TERM...JSH
AVIATION...TRM









AREA FORECAST DISCUSSION

NWS WILMINGTON OH

 1003 AM EDT THU AUG 16 2012

.SYNOPSIS...
WEAK HIGH PRESSURE WILL MOVE EAST TODAY AS A COLD FRONT APPROACHES
THE AREA FROM THE NORTHWEST. THE FRONT IS EXPECTED TO MOVE THROUGH
THE REGION TONIGHT INTO FRIDAY. CANADIAN HIGH PRESSURE WILL THEN
SETTLE ACROSS THE OHIO VALLEY FOR THE WEEKEND.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONVECTION MOVING INTO NORTHWEST INDIANA MAKES FOR CHALLENGING
FORECAST. THIS ACTIVITY IS NOT BEING HANDLED WELL BY MOST
NUMERICAL GUIDANCE. THE CLOSEST SEEMS TO BE THE HRRR RUNS AND EVEN
AMONGST THOSE THERE IS VARIABILITY ON CONVECTIVE EVOLUTION.

AT THIS POINT IT SEEMS THAT THESE STORMS WILL CONTINUE EASTWARDS
AND THUS SHOULD IMPACT AT LEAST WEST CENTRAL OHIO THIS AFTERNOON.
HAVE FORECAST SOME WEAKENING AS THIS CONTINUES INTO CENTRAL OHIO.
THEN EXPECT REDEVELOPMENT BACK WEST CLOSER TO A COLD FRONT LATER
IN THE AFTERNOON.

FORECAST HIGHS LOOK REASONABLE BASED ON WARMING LOW LEVELS AS
SAMPLED IN THE MORNING SOUNDING. ONLY QUESTION IS IF CONVECTION
COULD IMPACT READINGS MAINLY IN THE NORTHWEST. FOR THE TIME BEING
HAVE MADE LITTLE CHANGE IN THAT REGARD.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
THERE CONTINUES TO BE SOME SUBTLE TIMING DIFFERENCES AMONGST THE
MODELS IN TERMS OF FRONTAL SPEED THROUGH THE REGION TONIGHT INTO
FRIDAY. THE NAM IS THE SLOWEST...THE ECMWF THE SECOND
SLOWEST...WITH THE CMC AND GFS MOST PROGRESSIVE. HAVE LEANED
TOWARD THE CMC/GFS SOLUTIONS BUT ALLOWED FOR SOME LINGERING POST
FRONTAL PCPN IN THE SE ZONES INTO EARLY FRIDAY AFTERNOON.

OTHERWISE...A LINE OF SHOWERS AND THUNDERSTORMS SHOULD BE UNDERWAY
TO OUR WEST EARLY THIS EVENING IN AN AREA OF UPR LVL SUPPORT AND
LOW LEVEL FRONTAL CONVERGENCE. MODERATE SHEAR AND INSTABILITY WILL
LIKELY RENDER THESE STORMS TO BE SEVERE EARLY ON. HOWEVER...AS THE
FRONT PUSHES SOUTHEAST INTO OUR AREA...OVERALL INSTABILITY AND LOW
LEVEL CONVERGENCE WILL SHOW A WEAKENING TREND DURING THE OVERNIGHT
HOURS. AS A RESULT...HAVE GONE WITH CATEGORICAL POPS ACRS THE FAR
WRN/NWRN ZONES...AND THEN TAPERED THEM OFF TO LOW END LIKELY AS
THE PCPN MAKES ITS WAY TO THE SERN ZONES TOWARD FRIDAY MORNING.
AGREE WITH SPC THAT A FEW STORMS MAY STILL BE SEVERE AS THEY HEAD
INTO OUR WESTERN ZONES THIS EVENING INTO EARLY MORNING...SO WILL
HIGHLIGHT THIS THREAT IN THE HWO. DAMAGING WINDS WILL BE THE
PRIMARY SEVERE WEATHER THREAT WITH ISOLATED LARGE HAIL POSSIBLE.
FOR POINTS TO THE EAST/SE...THE SEVERE THREAT APPEARS TO BE
MINIMAL ATTM DUE TO AN EXPECTED WEAKENING TREND OF THE
AFOREMENTIONED PARAMETERS. OVERNIGHT LOWS WILL RANGE FROM THE
LOWER 60S NW TO THE UPPER 60S SE.

ON FRIDAY...LARGE SCALE MID LVL TROUGH WILL CONTINUE TO CARVE
ITSELF ACRS THE GREAT LAKES AND OHIO VALLEY REGION...PUSHING THE
COLD FRONT SOUTHEAST AWAY FROM THE AREA. HIGHEST POPS WILL BE
ONGOING DURING THE MORNING HOURS ACRS THE ERN/SERN ZONES...THEN
THE THREAT FOR RAIN SHOULD END BY THE EARLY AFTERNOON HOURS AS
DRIER AIR FILTERS IN BEHIND THE FRONT. SKIES SHOULD GRADUALLY
BECOME PARTLY CLOUDY FROM NW TO SE WITH SOME POST FRONTAL CAA
CUMULUS CLOUDS EXPECTED. WITH CAA...HIGHS WILL RANGE FROM THE
LOWER 70S NW TO THE UPPER 70S TO NEAR 80 SE.

FOR FRIDAY NIGHT...HIGH PRESSURE OF CANADIAN ORIGIN WILL BUILD
SOUTHEAST INTO THE OHIO VALLEY REGION. SKIES WILL BECOME MOSTLY
CLEAR WITH LIGHT NORTHERLY WINDS. TEMPERATURES WILL COOL
SUBSTANTIALLY FOR MID AUGUST WITH OVERNIGHT LOWS RANGING FROM THE
UPPER 40S NW TO THE MID 50S SE.

&&

.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
THE LONG TERM PERIOD WILL BE GENERALLY QUIET AND COMFORTABLE. A
CLOSED UPPER LEVEL LOW WILL REMAIN NEARLY STATIONARY NEAR JAMES BAY
IN CANADA...WITH AN ANOMALOUSLY DEEP LONG WAVE TROUGH EXTENDING INTO
THE EASTERN CONUS THROUGH THE BEGINNING OF NEXT WEEK. AT THE
SFC...HIGH PRESSURE WILL KEEP THE AREA UNDER NORTHERLY FLOW. A
WEAK SHORTWAVE ROUNDING THE TROUGH MAY INCREASE CLOUDS ON SUNDAY.
HAVE PLACED A 20 POP IN THE FAR NORTHERN COUNTIES...BUT WITH
LIMITED MOISTURE AND FORCING...THAT MAY BE GENEROUS. ANY OTHER
EMBEDDED SHORT WAVES LOOK EVEN WEAKER. MODELS ARE IN GOOD
AGREEMENT WITH THE LARGE SCALE FEATURES THROUGH MONDAY. THEN THERE
IS SOME DIVERGENCE AS A TROUGH MOVES ONTO THE WEST COAST AND THE
ENSUING DOWNSTREAM DEAMPLIFICATION OF THE PATTERN TAKES PLACE
DURING THE MIDDLE OF THE WEEK. HOWEVER THIS WILL HAVE LITTLE
IMPACT ON OUR SENSIBLE WEATHER (PERHAPS A FEW DEGREES ON
TEMPERATURES)...WITH THE SFC HIGH REMAINING IN CONTROL AS IT
GRADUALLY SHIFTS TO THE EAST COAST.

850 MB TEMPERATURE ANOMALIES AND ENSEMBLE SPREADS INDICATE THE
COLDEST AIR WILL BE OVER THE REGION ON SATURDAY. COMBINED WITH
DIURNAL CU...ELECTED TO GO A LITTLE BELOW GUIDANCE WITH HIGHS IN THE
LOWER TO MID 70S. THE DRY AIR MASS AND RADIATIONAL COOLING WILL
ALLOW FOR SEVERAL NIGHTS OF LOWS IN THE 50S. TEMPERATURES WILL
GRADUALLY REBOUND THROUGH MID WEEK...ALTHOUGH NOT REACHING
NEAR/SLIGHTLY ABOVE NORMAL VALUES UNTIL TUESDAY/WEDNESDAY WHEN
RETURN FLOW SETS UP. DEW POINTS WILL ONLY MODERATELY RECOVER AS
WELL...REMAINING COMFORTABLE AOB 60F THROUGH THE PERIOD.

&&

.AVIATION /14Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE OVER THE EASTERN US WILL SLIDE OFF THE EAST COAST AS
A COLD FRONT EXTENDING FROM WISCONSIN THROUGH EASTERN KANSAS MOVES
SOUTHEAST INTO THE FORECAST AREA TONIGHT.

SCT MID AND HI CLOUDS WILL MOVE SOUTHEAST ACROSS THE AREA
THROUGHOUT THE DAY TIME HOURS. SCT CU EXPECTED TO DEVELOP LATE
LATE THIS MORNING. HI CLOUDS FROM THUNDERSTORMS NW OF THE AREA
WILL THICKEN THROUGHOUT THE AFTERNOON AS THEY SPREAD EAST
SOUTHEASTWARD ACROSS THE AREA.

TONIGHT COLD FRONT WILL APPROACH THE AREA CAUSING CEILINGS TO
GRADUALLY LOWER THROUGHOUT THE NIGHT TIME HOURS. ISOLATED
CONVECTION WILL MOVE INTO WESTERN PORTIONS OF THE FORECAST AREA
LATE THIS EVENING WITH SHOWERS AND THUNDERSTORMS INCREASING TO
LIKELY AROUND MIDNIGHT. HAVE HANDLED THE BEST CHANCE FOR
THUNDERSTORMS IN THE TAF WITH A 3 TO 4 HOUR WINDOW OF PREVAILING
SHOWERS AND VCTS UNTIL TIMING CAN BE NAILED DOWN A LITTLE BETTER
WITH LATER FORECASTS. CONVECTION WILL DECREASE FROM NORTHWEST TO
SOUTHEAST STARTING AROUND 09Z. PATCHY FOG CONDITIONS WILL PRODUCE
MVFR CONDS STARTING AROUND 09Z WITH CEILINGS BECOMING MVFR MOST
AREAS LATE IN THE FORECAST PERIOD.

.OUTLOOK...THUNDERSTORMS POSSIBLE INTO FRIDAY MORNING.

&&

.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.

&&

$$
SYNOPSIS...HICKMAN
NEAR TERM...
SHORT TERM...HICKMAN
LONG TERM...HICKMAN/SNYDER
AVIATION...HAYDU







AREA FORECAST DISCUSSION

NWS NORMAN OK

 1010 PM CDT FRI AUG 17 2012

.AVIATION...
SHOWERS AND THUNDERSTORMS MAY FORM IN NORTHERN OKLAHOMA OVERNIGHT
AND MOVE SOUTHEAST. ANOTHER AREA WOULD BE SOUTHEAST OKLAHOMA ALSO
LATER TONIGHT. ON SATURDAY MORE RAIN AND THUNDERSTORMS MAY OCCUR
LATER IN THE AFTERNOON AND EVENING IN ADVANCE OF A COLD FRONT
WHICH IS EXPECTED TO MOVE FROM KANSAS AFTER 190000.

&&

.PREV DISCUSSION... /ISSUED 909 PM CDT FRI AUG 17 2012/

UPDATE...
DRIER AIR BEHIND FRONT REACHED MOST AREAS EXCEPT FAR SOUTHEAST
OKLAHOMA AND PART OF WESTERN NORTH TEXAS WHERE MID AND UPPER
60S DEWPOINT REMAIN. HRRR FAIRLY CONSISTENT IN DEVELOPING
SCATTERED SHOWERS AND STORMS AROUND 5-7Z ACROSS NORTH CENTRAL
AND MAYBE CENTRAL OKLAHOMA WIHTIN AREA OF WAA/DECENT MID-LEVEL
MOISTURE. CLOUDS HAVE BEEN DEVELOPING ACROSS THIS GENERAL
AREA OVER THE PAST HOUR. OUNWRF DEVELOPS PRECIP ALSO WITH
BETTER CONCENTRATION OF PRECIP ACROSS SOUTH CENTRAL
AND SOUTHEAST OKLAHOMA CLOSER TO SURFACE BOUNDARY. GENERALLY
HAVE 30 POPS MOST AREAS OVERNIGHT...BUT MAY INCREASE
POPS OVER NORTH CENTRAL/CENTRAL IF CLOUD/MODEL TRENDS
CONTINUE. IF PRECIP OCCURS...WILL ALSO NEED TO LOWER
TEMPS ACROSS THIS AREA WITH DRY NEAR SURFACE CONDITIONS.

PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 17 2012/

DISCUSSION...
THERE IS SOME SIGNIFICANT DISAGREEMENT AMONG THE NUMERIC MODELS
ABOUT THE RAIN CHANCES TONIGHT. GFS IS QUITE A BIT MORE AGGRESSIVE
WITH PRECIPITATION THAN NAM AND ECMWF... ESPECIALLY AFTER 06Z.
GIVEN THE RECENT HISTORY OF GFS PRECIP FORECASTS BEING MUCH TOO
HIGH WITH POPS AND QPF... HAVE OPTED TOWARD THE LESS AGGRESSIVE
SOLUTIONS. ONE AREA OF PRECIPITATION WILL LIKELY DEVELOP OVER THE
HIGH PLAINS... BUT THIS PRECIPITATION WILL LIKELY REMAIN MOSTLY
WEST OF THE FORECAST AREA. THERE IS ALSO A SIGNAL OF PRECIPITATION
DEVELOPING FROM NORTHWEST TO CENTRAL OKLAHOMA AS ISENTROPIC LIFT
DEVELOPS OVER THE FRONTAL SURFACE. DESPITE THIS... IT IS UNCLEAR
HOW WIDESPREAD THIS PRECIPITATION WILL BE. WITH ALL OF THESE
UNCERTAINTIES... HAVE GENERALLY GONE ON THE LOW SIDE OF GUIDANCE
RANGE. SIMILARLY... HAVE ALSO GENERALLY GONE ON THE LOW SIDE OF
GUIDANCE POP RANGES FOR TOMORROW AND TOMORROW NIGHT.

ONLY MINOR CHANGES WERE MADE TO THE EXTENDED PERIODS OF THE
FORECAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  69  86  69  86 /  30  40  40  20
HOBART OK         69  90  67  88 /  30  40  40  20
WICHITA FALLS TX  74  93  72  90 /  30  40  40  20
GAGE OK           63  84  60  86 /  30  40  30  10
PONCA CITY OK     63  82  63  86 /  30  40  30  10
DURANT OK         73  90  72  85 /  30  40  40  20

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

$$

06/09/09




AREA FORECAST DISCUSSION

NWS NORMAN OK

 909 PM CDT FRI AUG 17 2012

.UPDATE...
DRIER AIR BEHIND FRONT REACHED MOST AREAS EXCEPT FAR SOUTHEAST
OKLAHOMA AND PART OF WESTERN NORTH TEXAS WHERE MID AND UPPER
60S DEWPOINT REMAIN. HRRR FAIRLY CONSISTENT IN DEVELOPING
SCATTERED SHOWERS AND STORMS AROUND 5-7Z ACROSS NORTH CENTRAL
AND MAYBE CENTRAL OKLAHOMA WIHTIN AREA OF WAA/DECENT MID-LEVEL
MOISTURE. CLOUDS HAVE BEEN DEVELOPING ACROSS THIS GENERAL
AREA OVER THE PAST HOUR. OUNWRF DEVELOPS PRECIP ALSO WITH
BETTER CONCENTRATION OF PRECIP ACROSS SOUTH CENTRAL
AND SOUTHEAST OKLAHOMA CLOSER TO SURFACE BOUNDARY. GENERALLY
HAVE 30 POPS MOST AREAS OVERNIGHT...BUT MAY INCREASE
POPS OVER NORTH CENTRAL/CENTRAL IF CLOUD/MODEL TRENDS
CONTINUE. IF PRECIP OCCURS...WILL ALSO NEED TO LOWER
TEMPS ACROSS THIS AREA WITH DRY NEAR SURFACE CONDITIONS.

&&

.PREV DISCUSSION... /ISSUED 239 PM CDT FRI AUG 17 2012/

DISCUSSION...
THERE IS SOME SIGNIFICANT DISAGREEMENT AMONG THE NUMERIC MODELS
ABOUT THE RAIN CHANCES TONIGHT. GFS IS QUITE A BIT MORE AGGRESSIVE
WITH PRECIPITATION THAN NAM AND ECMWF... ESPECIALLY AFTER 06Z.
GIVEN THE RECENT HISTORY OF GFS PRECIP FORECASTS BEING MUCH TOO
HIGH WITH POPS AND QPF... HAVE OPTED TOWARD THE LESS AGGRESSIVE
SOLUTIONS. ONE AREA OF PRECIPITATION WILL LIKELY DEVELOP OVER THE
HIGH PLAINS... BUT THIS PRECIPITATION WILL LIKELY REMAIN MOSTLY
WEST OF THE FORECAST AREA. THERE IS ALSO A SIGNAL OF PRECIPITATION
DEVELOPING FROM NORTHWEST TO CENTRAL OKLAHOMA AS ISENTROPIC LIFT
DEVELOPS OVER THE FRONTAL SURFACE. DESPITE THIS... IT IS UNCLEAR
HOW WIDESPREAD THIS PRECIPITATION WILL BE. WITH ALL OF THESE
UNCERTAINTIES... HAVE GENERALLY GONE ON THE LOW SIDE OF GUIDANCE
RANGE. SIMILARLY... HAVE ALSO GENERALLY GONE ON THE LOW SIDE OF
GUIDANCE POP RANGES FOR TOMORROW AND TOMORROW NIGHT.

ONLY MINOR CHANGES WERE MADE TO THE EXTENDED PERIODS OF THE
FORECAST.

&&

.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK  69  86  69  86 /  30  40  40  20
HOBART OK         69  90  67  88 /  30  40  40  20
WICHITA FALLS TX  74  93  72  90 /  30  40  40  20
GAGE OK           63  84  60  86 /  30  40  30  10
PONCA CITY OK     63  82  63  86 /  30  40  30  10
DURANT OK         73  90  72  85 /  30  40  40  20

&&

.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&

$$




AREA FORECAST DISCUSSION

NWS NASHVILLE TN

 628 PM CDT FRI AUG 17 2012

.UPDATE...SATELLITE PICS SHOW CLOUDS ARE SOMEWHAT SLOWER TO CLEAR
OUT THAN PREVIOUSLY EXPECTED, AND AM SOMEWHAT UNCERTAIN HOW FAST CLOUDS
WILL CLEAR FOLLOWING SUNSET. THIS, IN ADDITION TO THE FACT THAT
THE LATEST 1000-850MB RH PROGS FROM THE RUC SHOW A SLOWER
DISSIPATION OF LOW LEVEL MOISTURE DURING THE FIRST PART OF THE
NIGHT, HAVE LED TO THE CONCLUSION THAT GRIDS AND FORECAST SHOULD
BE UPDATED TO GO WITH A SOMEWHAT CLOUDIER OVERNIGHT
FORECAST...ESPECIALLY SOUTH AND EAST. IN ADDITION, BELIEVE WHERE
CLEARING TAKES PLACE WE COULD SEE FOG AND LOW CLOUDS RE-DEVELOP.
THUS, HAVE ADDED PATCHY FOG INTO THE FORECAST AS WELL. HAVE LEFT
ALL OTHER FORECAST VARIABLES ALONE FOR NOW.


&&

.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

19






AREA FORECAST DISCUSSION...UPDATED

NWS SAN ANGELO TX

 643 PM CDT FRI AUG 17 2012

.DISCUSSION...
SEE AVIATION SECTION.

&&

.AVIATION...
AVIATION FORECAST FOR THIS PACKAGE LARGELY REVOLVES AROUND PLACEMENT
OF CONVECTION AND ASSOCIATED EFECTS. ONE OF THE MAIN CHANGES WITH
THE 00Z PACKAGE IS TO REMOVE/REDUCE LONG-PERIOD /UP TO 20 HOURS AT
KSJT/ VCTS GROUPS. MOST OF THE SHOWERS AND THUNDERSTORMS THIS
EVENING HAVE BEEN ACROSS THE AREA SOUTH OF INTERSTATE 20 AND NORTH
OF INTERSTATE 10...WITHIN SUBTROPICAL MOISTURE PLUME. OVERALL
STEERING FLOW IS WEAK...BUT THE GENERAL PROPAGATION AND NEW
DEVELOPMENT HAS BEEN MOSTLY TO THE SOUTH-SOUTHEAST. FORECAST
PLACEMENT OF CONVECTION IS VERY PROBLEMATIC FOR THE NEXT 24 HOURS.
BELIEVE MOST OF THE CURRENT CONVECTION...WHICH IS SURFACE BASED AND
DIURNALLY DRIVEN...WILL DISSIPATE EARLY TONIGHT. WHILE REDEVELOPMENT
OF CONVECTION CANNOT BE RULED OUT OVERNIGHT...THE CHANCE APPEARS LOW
ENOUGH TO PRECLUDE MENTIONING IN THE AREA TAFS. A BETTER CHANCE OF
REDEVELOPMENT WILL BE DURING THE DAY SATURDAY WITH DIURNAL HEATING
AND DESTABILIZATION OF THE MOIST AIRMASS. WILL HAVE MULTIPLE OUTFLOW
BOUNDARIES ACROSS THE AREA WHICH WHERE CONVECTION MAY INITIATE. WILL
CARRY VCTS AFTER 16Z OR 17Z AT MOST IF NOT ALL TAF SITES. A FEW
STRONGER STORMS WITH GUSTS OVER 35 KT WILL BE POSSIBLE. LOCALIZED
REDUCTIONS IN VISIBILITY AND CEILING ARE ALSO POSSIBLE IN THE HEAVY
RAINFALL WHICH ACCOPMANIES THE CONVECTION. WINDS TONIGHT WILL BE
VARIABLE AT SPEEDS UNDER 10 KT. ON SATURDAY...WINDS OUTSIDE OF
CONVECTIVE INFLUENCES WILL BE MOSTLY SOUTHEAST TO SOUTH AT 5-10 KT.

&&

.PREV DISCUSSION... /ISSUED 312 PM CDT FRI AUG 17 2012/

SHORT TERM...
FOR THIS AFTERNOON INTO THIS EVENING...HAVE RAISED POPS A LITTLE
THROUGH THE REST OF THE CONCHO VALLEY. HIGH RESOLUTION RAP SOLUTION
HAS CONVECTION ACROSS THE CONCHO VALLEY THROUGH THE AFTERNOON AND
THEN DEVELOPS MORE CONVECTION ACROSS THE BIG COUNTRY. THE RAP HAS
MORE BROAD CONVECTION ACROSS THE AREA WHILE THE TEXAS TECH 3KM WRF
HAS THE ACTIVITY TOO FAR NORTH. TAKING A LOOK AT SHOWERS AND
THUNDERSTORMS THAT ARE ALREADY FORMING...THE HIGH RESOLUTION RAP
MODEL LOOKS TO BE A BETTER SOLUTION. HAVE NOT CHANGED MUCH THROUGH
THE REST OF TONIGHT AND TOMORROW. MOST OF ACTIVITY LOOKS TO BE
SCATTERED AS IT WILL BE DRIVEN BY MESOSCALE PROCESSES.

REIMER

LONG TERM...
PRECIPITATION CHANCES WILL CONTINUE THROUGH THE FIRST PART OF THE
EXTENDED FORECAST. A WEAK COLD FRONT THAT IS CURRENTLY STALLED
ACROSS WEST CENTRAL TEXAS WILL REMAIN IN THE VICINITY OF THE AREA
AND BECOME FAIRLY DIFFUSE BY LATE SATURDAY. REGARDLESS...THE FRONT
WILL SERVE AS A FOCUS FOR CONTINUED SHOWERS AND THUNDERSTORMS ACROSS
ALL OF THE REGION SATURDAY NIGHT. SATURDAY...A SHORTWAVE TROUGH WILL
SWING ACROSS THE PLAINS...ALONG THE SOUTHERN PERIPHERY OF THE MAIN
UPPER LEVEL TROUGH THAT IS FORECAST TO BE LOCATED OVER THE MIDWEST.
THIS WILL SEND A REINFORCING SHOT OF SURFACE HIGH PRESSURE DOWN THE
PLAINS AND INTO WEST CENTRAL TEXAS ON SUNDAY. THIS WILL RESULT IN
DECREASING RAIN CHANCES FROM NORTH TO SOUTH THROUGHOUT THE DAY
SUNDAY. I COOLED HIGH TEMPERATURES SUNDAY BY A DEGREE OR TWO...GIVEN
THE EXPECTED CLOUD COVER AND RAINFALL...AND THESE MAY NEED TO
EVENTUALLY BE LOWERED EVEN MORE. SUNDAY NIGHT...RAIN CHANCES WILL BE
CONFINED TO THE CONCHO VALLEY AND AREAS TO THE SOUTH. ALTHOUGH A FEW
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT
THROUGH SUNDAY...THE MAIN THREAT IS THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL.

BEYOND SUNDAY...A SLOW WARMING TREND IS EXPECTED...WITH TEMPERATURES
BACK INTO THE MID 90S BY MID WEEK. MODELS ARE STILL INDICATING A
DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW ALOFT...DROPPING THROUGH
THE TEXAS PANHANDLE MONDAY NIGHT OR TUESDAY. THIS WILL LIKELY RESULT
IN AN MCS DEVELOPING ACROSS THE PANHANDLE AND THEN MOVING SOUTHEAST.
AT THIS TIME...CONFIDENCE IS NOT HIGH ENOUGH IN THIS FEATURE
REACHING WEST CENTRAL TEXAS...SO I HAVE LEFT POPS BELOW 15 PERCENT.

DANIELS

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  73  95  71  90  68 /  40  50  50  30  10
SAN ANGELO  74  95  72  91  69 /  30  40  50  40  20
JUNCTION  74  97  72  92  70 /  20  30  40  40  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$










AREA FORECAST DISCUSSION...UPDATED

NWS SAN ANGELO TX

 634 PM CDT FRI AUG 17 2012

.DISCUSSION...
SEE AVIATION SECTION.

&&

.AVIATION...
AVIATION FORECAST FOR THIS PACKAGE LARGELY REVOLVES AROUND PLACEMENT
OF CONVECTION AND ASSOCIATED EFECTS. ONE OF THE MAIN CHANGES WITH
THE 00Z PACKAGE IS TO REMOVE/REDUCE LONG-PERIOD /UP TO 20 HOURS AT
KSJT/ VCTS GROUPS. MOST OF THE SHOWERS AND THUNDERSTORMS THIS
EVENING HAVE BEEN ACROSS THE AREA SOUTH OF INTERSTATE 20 AND NORTH
OF INTERSTATE 10...WITHIN SUBTROPICAL MOISTURE PLUME. OVERALL
STEERING FLOW IS WEAK...BUT THE GENERAL PROPAGATION AND NEW
DEVELOPMENT HAS OCCURRED MOSTLY TO THE SOUTH- SOUTHEAST. FORECAST
PLACEMENT OF CONVECTION IS VERY PROBLEMATIC FOR THE NEXT 24
HOURS. BELIEVE MOST OF THE CURRENT CONVECTION...WHICH IS SURFACE
BASED AND DIURNALLY DRIVEN...WILL DISSIPATE EARLY TONIGHT. WHILE
REDEVELOPMENT OF CONVECTION CANNOT BE RULED OUT OVERNIGHT...THE
CHANCE APPEARS LOW ENOUGH TO PRECLUDE MENTIONING IN THE AREA TAFS.
A BETTER CHANCE OF REDEVELOPMENT WILL BE DURING THE DAY SATURDAY
WITH DIURNAL HEATING AND DESTABILIZATIO OF THE AIRMASS. WILL HAVE
MULTIPLE OUTFLOW BOUNDARIES ACROSS THE AREA WHICH WHERE CONVECTION
MAY INITIATE. WILL CARRY VCTS AFTER 16Z OR 17Z AT MOST IF NOT ALL
TAF SITES. A FEW STRONGER STORMS WITH GUSTS OVER 35 KT WILL BE
POSSIBLE. LOCALIZED REDUCTIONS IN VISIBILITY AND CEILING ARE ALSO
POSSIBLE IN THE HEAVY RAINFALL WHICH ACCOPMANIES THE CONVECTION.
WINDS TONIGHT WILL BE VARIABLE TONIGHT AT SPEEDS UNDER 10 KT. ON
SATURDAY...WINDS WILL BE MOSTLY SOUTHEAST TO SOUTH AT 5-10 KT.

&&

.PREV DISCUSSION... /ISSUED 312 PM CDT FRI AUG 17 2012/

SHORT TERM...
FOR THIS AFTERNOON INTO THIS EVENING...HAVE RAISED POPS A LITTLE
THROUGH THE REST OF THE CONCHO VALLEY. HIGH RESOLUTION RAP SOLUTION
HAS CONVECTION ACROSS THE CONCHO VALLEY THROUGH THE AFTERNOON AND
THEN DEVELOPS MORE CONVECTION ACROSS THE BIG COUNTRY. THE RAP HAS
MORE BROAD CONVECTION ACROSS THE AREA WHILE THE TEXAS TECH 3KM WRF HAS
THE ACTIVITY TOO FAR NORTH. TAKING A LOOK AT SHOWERS AND
THUNDERSTORMS THAT ARE ALREADY FORMING...THE HIGH RESOLUTION RAP MODEL
LOOKS TO BE A BETTER SOLUTION. HAVE NOT CHANGED MUCH THROUGH THE
REST OF TONIGHT AND TOMORROW. MOST OF ACTIVITY LOOKS TO BE
SCATTERED AS IT WILL BE DRIVEN BY MESOSCALE PROCESSES.

REIMER

LONG TERM...
PRECIPITATION CHANCES WILL CONTINUE THROUGH THE FIRST PART OF THE
EXTENDED FORECAST. A WEAK COLD FRONT THAT IS CURRENTLY STALLED
ACROSS WEST CENTRAL TEXAS WILL REMAIN IN THE VICINITY OF THE AREA
AND BECOME FAIRLY DIFFUSE BY LATE SATURDAY. REGARDLESS...THE FRONT
WILL SERVE AS A FOCUS FOR CONTINUED SHOWERS AND THUNDERSTORMS ACROSS
ALL OF THE REGION SATURDAY NIGHT. SATURDAY...A SHORTWAVE TROUGH WILL
SWING ACROSS THE PLAINS...ALONG THE SOUTHERN PERIPHERY OF THE MAIN
UPPER LEVEL TROUGH THAT IS FORECAST TO BE LOCATED OVER THE MIDWEST.
THIS WILL SEND A REINFORCING SHOT OF SURFACE HIGH PRESSURE DOWN THE
PLAINS AND INTO WEST CENTRAL TEXAS ON SUNDAY. THIS WILL RESULT IN
DECREASING RAIN CHANCES FROM NORTH TO SOUTH THROUGHOUT THE DAY
SUNDAY. I COOLED HIGH TEMPERATURES SUNDAY BY A DEGREE OR TWO...GIVEN
THE EXPECTED CLOUD COVER AND RAINFALL...AND THESE MAY NEED TO
EVENTUALLY BE LOWERED EVEN MORE. SUNDAY NIGHT...RAIN CHANCES WILL BE
CONFINED TO THE CONCHO VALLEY AND AREAS TO THE SOUTH. ALTHOUGH A FEW
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT
THROUGH SUNDAY...THE MAIN THREAT IS THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL.

BEYOND SUNDAY...A SLOW WARMING TREND IS EXPECTED...WITH TEMPERATURES
BACK INTO THE MID 90S BY MID WEEK. MODELS ARE STILL INDICATING A
DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW ALOFT...DROPPING THROUGH
THE TEXAS PANHANDLE MONDAY NIGHT OR TUESDAY. THIS WILL LIKELY RESULT
IN AN MCS DEVELOPING ACROSS THE PANHANDLE AND THEN MOVING SOUTHEAST.
AT THIS TIME...CONFIDENCE IS NOT HIGH ENOUGH IN THIS FEATURE
REACHING WEST CENTRAL TEXAS...SO I HAVE LEFT POPS BELOW 15 PERCENT.

DANIELS

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  73  95  71  90  68 /  40  50  50  30  10
SAN ANGELO  74  95  72  91  69 /  30  40  50  40  20
JUNCTION  74  97  72  92  70 /  20  30  40  40  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$







AREA FORECAST DISCUSSION

NWS LUBBOCK TX

 1218 AM CDT THU AUG 16 2012

.AVIATION...
TSRA WILL APPROACH KCDS DURING THE FIRST SEVERAL HRS OF FORECAST.
IF CONVECTION CONTINUES CURRENT PROPAGATION TRENDS...TSRA MAY
IMPACT KCDS OR VCTY BTWN 09Z AND 11Z. ANY IMPACTS TO THE
TERMINAL SHOULD LAST LESS THAN AN HOUR AND WILL LIKELY NOT FALL
BELOW MVFR CAT. OTHERWISE...VFR CONDITIONS EXPECTED AT BOTH KLBB
AND KCDS THROUGH THE FORECAST PERIOD. JH
&&

.PREV DISCUSSION... /ISSUED 653 PM CDT WED AUG 15 2012/

AVIATION...
ALTHOUGH ISLD TSRA WILL APPROACH KLBB TERMINAL FROM THE WEST
THROUGH 16/06Z...DO NOT ANTICIPATE ANY IMPACTS. ADDITIONAL ISOLD
SHRA/TSRA WILL BE POSSIBLE ACROSS W TX THU AFTN...BEYOND 16/18Z.
HOWEVER...ANY POTENTIAL IMPACTS WILL BE BRIEF AND WILL LIKELY NOT
FALL BELOW MVFR CAT. OTHERWISE...VFR CONDITIONS EXPECTED AT BOTH
KLBB AND KCDS THROUGH THE FORECAST PERIOD. JH

PREV DISCUSSION... /ISSUED 313 PM CDT WED AUG 15 2012/

SHORT TERM...
WE HAVE SOME MIXED SIGNALS REGARDING TSTM CHANCES LATE THIS
AFTERNOON AND EVENING. ON ONE HAND...LOW MOISTURE HAS INCREASED
MARKEDLY OVER YESTERDAY AND WE REMAIN UNDERNEATH A WEST-EAST MID-LVL
MOISTURE AXIS AS WELL. ON THE OTHER HAND...THE MOISTURE HAS DELAYED
HEATING AND THE AREA WAS STILL CAPPED AS OF 2 PM. NW FLOW CONTINUES
ALOFT AND WATER VAPOR IMAGERY SHOWS THE NEXT SHORTWAVE MOVING INTO
NRN NM AT THIS TIME....WHICH IS HELPING TO INITIATE STORMS ALL ALONG
THE NEW MEXICO MTNS. THERE IS ALSO SOME CU DEVELOPMENT IN THE
EAST TO SOUTH-CENTRAL TX PANHANDLE ALONG A SFC TROUGH AND AS THE CAP
WEAKENS WE COULD SEE SOME STORMS DEVELOP ALONG THIS TROUGH INTO
THE FAR SRN PANHANDLE...POSSIBLY SWISHER AND BRISCOE COUNTIES.
FINALLY...WE HAVE ANOTHER WEAK SFC TROUGH NEAR THE TX-NM BORDER
WHICH COULD ALSO BE THE FOCUS FOR SOME STORM DEVELOPMENT WEST OF
HIGHWAY 214. SO WITH ALL THIS...WE HAVE A SLGT CHANCE GOING ACROSS
THE ENTIRE FA THIS AFTERNOON FOR THE POSSIBILITY OF SOME LOCAL
DEVELOPMENT. BUT WE EXPECT THE MAIN SHOW SO TO SPEAK TO BE LATER
THIS EVENING AS A BROKEN LINE/LOOSE COMPLEX OF STORMS MOVES
ROUGHLY E-SEWD OUT OF EASTERN NEW MEXICO....ACROSS THE SPLNS AND
POSSIBLY INTO THE ROLLING PLAINS TONIGHT. THE HRRR HAS BEEN RATHER
CONSISTENT IN THIS DEPICTION...WHILE MUCH OF THE OTHER GUIDANCE
WEAKENS THE ACTIVITY AS IT MOVES EAST. WITH THE UPPER WAVE
PROVIDING SOME BACKGROUND ASCENT AND A 30 TO 40 KT SRLY LLJ WE
CURRENTLY ANTICIPATE THE ACTIVITY MAKING IT AT LEAST INTO THE
CENTRAL SPLNS AND FAR SRN PANHANDLE. DEEP LAYER SHEAR IS CURRENTLY
VERY WEAK...BUT WILL INCREASE THIS EVENING AS THE LLJ CRANKS UP.
INSTABILITY IS ALSO ON THE WEAK TO MODERATE SIDE...HIGHEST
POSITIONED ACROSS THE NORTH. THIS ENVIRONMENT SHOULD SUPPORT THE
THREAT FOR ISOLATED STRONG TO SEVERE WIND GUSTS...WITH THE DEEPER
MOISTURE SUPPORTING STRONGER COLD POOLS AND BETTER RAINFALL
POTENTIAL AS WELL.

WHILE WE SHOULD SEE MOST ACTIVITY WANE IN THE EARLY MORNING
HRS...CONTINUED BROAD UPWARD MOTION IN NW FLOW WILL KEEP A CHANCE OF
SOME ISOLD SHOWERS/TSTMS GOING THROUGH THU MORNING. THEN...A COLD
FRONT IS EXPECTED TO MOVE INTO OUT NRN ZONES LATE THU
MORNING...LIKELY STALLING OUT SOMEWHERE ACROSS THE FAR SRN PANHANDLE
AND NW SPLNS BY MIDDAY OR EARLY AFTERNOON. THIS FRONT SHOULD ABLY SERVE
AS A FOCUS FOR CONVECTIVE INITIATION THURSDAY AFTERNOON. TEMPS MAY
NOT MAKE IT OUT OF THE 80S NORTH OF THE FRONT...WHILE WE EXPECT
HIGHS TO ONCE AGAIN CLIMB INTO THE UPPER 90S TO THE SOUTH OF THE
FRONT. SOUTH OF THE FRONT...THERE WILL BE SOME DOWNBURST POTENTIAL
FROM THE TSTM ACTIVITY....WHILE NORTH OF THE FRONT RAINFALL CHANCES
WILL BE BETTER.

LONG TERM...
THURSDAY NIGHT THRU SATURDAY...
THE COLD FRONT FROM EARLIER IN THE DAY THURSDAY SHOULD BE STALLED
SOMEWHERE IN THE NORTHERN HALF OF THE CWA BY THURSDAY EVENING. A
GENERAL WEAKNESS IN WINDS ALOFT MAY ACT TO KEEP CONVECTION FOCUSED
RELATIVELY CLOSE TO THE BOUNDARY...OR PERHAPS EVEN NORTH OF THE
FRONT AS ISENTROPIC LIFT IS PROGGED TO AMPLIFY OVERNIGHT AS PER THE
GFS. OPTED TO THEREFORE TIGHTEN THE POP GRADIENT THU NIGHT FROM
NORTH-TO-SOUTH TO REFLECT THIS THINKING. BY FRIDAY...ATTENTION WILL
TURN MORE TO THE SUBTROPICAL PLUME OF MOISTURE CURRENTLY HUGGING THE
WRN COAST OF MEXICO. SOME OF THIS MOISTURE WILL SPREAD NORTH BEFORE
CURLING EASTWARD INTO WEST TX WITHIN A REGION OF LOWERED HEIGHTS
BETWEEN TWO 700MB HIGH CENTERS. PROVIDED THE OSCILLATING FRONTAL
BOUNDARY REMAINS IN THE CWA...LIKELY POPS MAY BE WARRANTED FRI AFTN.
HOWEVER...THIS STRATEGY IS CLOUDED WITH DOUBT AS THE NAM NOW
RETREATS THE BOUNDARY WELL NORTH INTO THE PANHANDLE WHILE PUSHING
HIGHS AREA WIDE INTO THE 90S. NOT YET WILLING TO BREAK CONTINUITY AS
THE NAM`S FRONTAL SOLUTION SEEMS TOO AGGRESSIVE...SO WILL SIDE WITH
THE GFS FAVORING A MORE SOUTHERLY BOUNDARY POSITION. A LULL IN PRECIP
CHANCES MAY VERY WELL DEVELOP FRI EVENING BEFORE DEEPER ASCENT
ARRIVES LATE IN THE NIGHT AND EARLY SAT COURTESY OF A CYCLONICALLY
CURVED JET STREAK DIVING THROUGH THE SOUTHERN GREAT PLAINS. ENHANCED
UPPER DIVERGENCE IN THE EXIT REGION OF THIS 2-CELL MAXIMA WOULD TEND
TO FAVOR THE BEST POPS AFTER MIDNIGHT PRIMARILY ACROSS THE NERN 1/3
OF THE CWA BEFORE EXPANDING OVER THE REMAINDER OF THE AREA SAT
MORNING AS THE BASE OF AN UPPER TROUGH IN NWLY FLOW DRAWS CLOSER.
GIVEN THIS PATTERN IN THE PRESENCE OF PWATS AROUND 1.5 INCHES...WE
COULD CERTAINLY RATCHET POPS INTO THE LIKELY REALM...BUT WILL SETTLE
FOR HIGH CHANCE AT THIS TIME AS THIS WINDOW IS STILL FIVE PERIODS
OUT AND SUBJECT TO CHANGE.

GFS AND ECMWF ARE IN A SURPRISINGLY GOOD AGREEMENT...FOR THE MOST PART...
FOR THE PERIODS SAT THRU TUES. BOTH SEEM TO BE IN AN AGREEMENT WITH
A STALLED FRONT DRAPED FROM THE NC COAST TO THE TX PANHANDLE.
DEWPOINTS WILL BE FAIRLY HIGH...AROUND THE LOWER 60S. THIS COUPLED
WITH UPPER LEVEL DIVERGENCE SHOULD ALLOW WITH SOME PRECIP. I HAVE
BUMPED UP THE POPS JUST A BIT FOR SAT EVENING. THE FRONT SHOULD MOVE
OUT OF THE AREA BY SUN MORNING/EARLY AFTERNOON. HIGHS FOR SAT SHOULD
BE IN THE UPPER 80S. BEYOND THEN THE MODELS VARY IN PRECIP CHANCES.
THE GFS KEEPS PRECIP SOMEWHAT SUPPRESSED AND LOCALIZED OVER THE
PANHANDLE WITH THE INFLUENCE OF AN UPPER LEVEL HIGH WHILE THE 12Z
ECMWF HAS MORE WIDESPREAD COVERAGE DUE TO THE INFLUENCE OF A
SHORTWAVE TROF OVER KS. HAVE KEPT POPS ON THE DOWN LOW AT THE
CURRENT TIME DUE TO UNCERTAINTY BUT DO HAVE A MENTION OF THEM.
LATER IN THE PERIOD AROUND WED THE 12Z GFS AND THE 00Z ECMWF
DIFFER...ESPECIALLY NEAR THE SURFACE. THE GFS IS TRYING TO DEVELOP A
1001 MB LOW IN EASTERN MT WITH A SURFACE TROF DRAPED DOWN TO THE OK
PANHANDLE WED MORNING AND DEEPENS IT TO A 997 MB LOW BY THUR
MORNING...WHILE PUSHING A DRYLINE INTO THE WESTERN PANHANDLE. THE
ECMWF HAS A 1022 MB HIGH OVER MT AND SINKS DOWN TO CO BY THUR
MORNING. HOWEVER...THE NEW 12Z ECMWF HAS COME MORE IN LINE WITH THE
12Z GFS EXCEPT WITH ABOUT A 6 HOUR TIMING DELAY. EITHER WAY...UPPER
LEVEL RIDGING APPEARS TO BE THE NAME OF THE GAME OVER WESTERN TEXAS
AND THAT SHOULD HELP SUPPRESS CONVECTION AND KEEP TEMPS AT THE SURFACE
WARM. ALDRICH
&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        65  86  63  85  65 /  30  40  40  40  40
TULIA         67  88  65  86  65 /  30  40  40  40  50
PLAINVIEW     68  90  65  86  66 /  30  30  40  40  50
LEVELLAND     68  93  67  88  67 /  30  30  20  40  40
LUBBOCK       70  93  68  88  68 /  30  30  20  40  40
DENVER CITY   69  94  68  88  68 /  20  20  20  30  30
BROWNFIELD    67  94  68  89  68 /  20  20  20  30  40
CHILDRESS     72  97  69  90  69 /  20  30  40  40  50
SPUR          70  96  70  90  71 /  20  20  20  40  50
ASPERMONT     71 100  72  92  71 /  20  20  20  30  50
&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

02






AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 938 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A COLD FRONT WILL CONTINUE HEADING SOUTHEAST THROUGH...AND THEN
OUT OF THE REGION TONIGHT. DEEPENING LOW PRESSURE...ANCHORED OVER
SOUTHEAST CANADA...WILL EVOLVE ACROSS THE EASTERN U.S. FOR THE
WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A SERIES OF DISTURBANCES
EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 934 PM EDT FRIDAY...

ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH A COLD FRONT HAVE
ENTERED THE FAR SOUTHWEST PORTION OF THE FORECAST AREA. LITTLE IF
ANY PRECIPITATION WAS OCCURRING ELSEWHERE. BELIEVE THE REMAINDER
OF THE NIGHT WILL WELCOME THE ISOLATED TO SCATTERED SHOWERS ALONG
THE FRONT AS IT PROGRESSES EAST OF THE CREST OF THE BLUE RIDGE.
AROUND DAYBREAK SATURDAY...GUIDANCE SUGGEST A DISTURBANCE WILL BE
RIDING ALONG THE FRONT THROUGH THE CAROLINAS. THIS MAY HAVE THE
IMPACT OF INCREASING THE COVERAGE OF SHOWERS ACROSS SOUTHSIDE
VIRGINIA AND NEIGHBORING SECTIONS OF NORTH CAROLINA AT THIS TIME.
HAVE ADJUSTED PERCENTAGE OF PRECIPITATION CHANCES AND WEATHER
GRIDS TO REFLECT THIS THINKING. HAVE ALSO TWEAKED HOURLY GRIDS FOR
TEMPERATURE...DEW POINT...AND WIND BASED UPON CURRENT CONDITIONS
AND EXPECTED TRENDS INTO EARLY SATURDAY MORNING.

AS OF 715 PM EDT FRIDAY...

HAVE TRIMMED BACK PRECIPITATION CHANCES BASED UPON THE LATEST
TRENDS OF KFCX AND OTHER NEIGHBORING 88D RADARS. FIRST LINE OF
CONVECTION WILL BE EAST OF THE FORECAST AREA BY 800 PM. NEXT LINE
OF PRECIPITATION WILL BE ASSOCIATED WITH THE ACTUAL COLD FRONT.
RADARS ARE SHOWING AN ISOLATED TO SCATTERED COVERAGE WITH THIS
ACTIVITY. ANTICIPATE CONVERAGE TO BE OF A SIMILAR OR LESS COVERAGE
AS THE FRONT HEADS EAST AND ENCOUNTERS THE RELATIVELY STABLE AREA
ACROSS THE REGION...ESPECIALLY WITH THE SOON LOSS OF SUNSHINE.
HAVE ALSO ADJUSTED TEMPERATURE...DEW POINT...AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
EVENING.

AS 310 PM EDT FRIDAY...

SFC COLD FRONT LOCATED TO OUR WEST FROM WESTERN PENNSYLVANIA
SOUTHWARD TO EASTERN KY. THIS FRONT WILL MOVE SOUTHEAST TONIGHT INTO
SATURDAY. CONVECTION COVERAGE SHOULD INCREASE LATE THIS AFTERNOON
INTO TONIGHT...DUE TO COMBINATION OF DIFFERENTIAL HEATING EFFECTS
AND THE APPROACH OF COLD FRONT/MID-LEVEL SHORT WAVE TROUGH. AT THIS
TIME...REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED
THUNDERSTORMS MOVING EAST ACROSS WESTERN PORTIONS OF CWA. LOOKS LIKE
THE BEST INSTABILITY IS JUST AHEAD OF THE CLOUD DECK. SPC RECENTLY
REMOVED MUCH OF THE AREA FROM THEIR SLIGHT RISK...AND THIS SEEMS
REASONABLE...ESPECIALLY IN LIGHT OF THE WEAK SHEAR OVER THE REGION.
AN ISOLATED STRONG TO SEVERE THUNDERSTORM MAY BE POSSIBLE THIS
EVENING WITH MAIN THREAT HEAVY RAINS AND GUSTY WINDS.

THUNDERSTORMS AND SHOWERS SHOULD WANE/DIMINISH TONIGHT AS THE
UPPER SHORT WAVE SHEARS OUT AND THE MAIN DYNAMICS MOVE TOWARD NEW
ENGLAND.  ANOTHER SHORTWAVE POISED THE MOVE ACROSS THE UPPER
MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG SW FLOW ALOFT AND
DELAY ANY CLEARING. WITH PLENTY OF CLOUDS TONIGHT...PLAYED LOW
TEMPERATURES CLOSE TO THE ADJMET WITH READINGS FROM AROUND 60
DEGREES IN THE MOUNTAINS TO THE UPPER 60S TO NEAR 70 IN THE
SOUTHEAST.

THE COLD FRONT WILL MOVE SOUTH INTO NORTH CAROLINA FOR SATURDAY.
THERE IS ENOUGH MOISTURE TO COMBINED WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW THUNDERSTORMS. HIGH TEMPERATURES ON SATURDAY WILL VARY THE MID
70S IN THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EDT FRIDAY...

COLD FRONT WILL BE DOWN IN THE CAROLINAS BY SAT NIGHT WITH DRIER AND
COOLER AIR SEEPING SOUTHBOUND ALLOWING FOR AN EXODUS OF MOST
LEFTOVER SHRA OVER THE SOUTH SAT EVENING. NEXT MID LEVEL IMPULSE
PROGGED BY MOST MODELS WILL ROUND THE 5H TROF SLIDING THRU THE UPPER
MIDWEST SUNDAY AND DAMPEN UPON PASSING INTO THE OHIO VALLEY SUNDAY
NIGHT. DEEPER MOISTURE WITH THE RESIDUAL FRONT LOOKS TO REMAIN JUST
SOUTH OF THE CWA THOUGH AS OVERALL MID LEVEL BACKING OF THE FLOW
AHEAD OF THE WAVE APPEARS WEAK ATTM. HOWEVER WITH LOW LEVEL
TRAJECTORIES TURNING MORE SOUTH/SE AND A RIBBON OF HIGHER SFC-85H
THETA-E SPREADING ALONG/EAST OF THE BLUE RIDGE...WENT AHEAD AND
EXPANDED THE CHANCE POPS NORTH SUNDAY/SUNDAY EVENING...WITH BEST
COVERAGE SOUTHERN HALF WHERE SOME CAPE WILL EXIST. SHRA MAY LINGER
EAST SUNDAY NIGHT AND BUBBLE BACK TO THE WEST ON MONDAY AS YET
ANOTHER UPPER LEVEL DISTURBANCE SPINS BY AND PERHAPS INDUCES A SFC
WAVE ALONG THE FRONT TO THE SOUTH MONDAY AFTERNOON PER THE LASTEST
CANADIAN. AGAIN MAINLY MIDDLE RANGE CHANCE POPS FOR NOW GIVEN
UNCERTAINTY AND ONLY SLIGHT POPS FAR WEST/NW WHERE REMOVED FROM THE
DEEPER RH. OTRW MORE CLOUDS SOUTH/EAST AND PERHAPS MORE
BREAKS/CLEARING AT TIMES NORTH-NW THRU MONDAY. CLOUDS/SHRA SHOULD
KEEP HIGHS MAINLY IN THE 70S TO LOW 80S WITH LOWS 50S TO LOW 60S
MOUNTAINS...AND 60-65 BEHIND THE FRONT OUT EAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...

UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.

&&

.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 830 PM EDT FRIDAY...

SHOWERS AND THUNDERSTORMS HAVE MAINLY EXITED THE REGION AS OF 00Z.
THE EXCEPTION IS SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS WESTERN
VIRGINIA AS A WEAK DISTURBANCE PASSES BY. LEFT A CHANCE OF RAIN AT
BLF THROUGH 02Z. THE HRRR FORECAST MODEL SHOWS ANY SHOWERS THAT
DEVELOP ALONG THE COLD FRONT WILL DISSIPATE EAST OF THE BLUE RIDGE
TONIGHT THANKS TO THE NORTHWESTERLY DOWNSLOPE FLOW.

WESTERLY FLOW WILL PROMOTE LOW CEILINGS AT LWB AND BLF...AND
POSSIBLY FOR A SHORT TIME AT BCB...IFR CONDITIONS ARE EXPECTED
DURING THE EARLY MORNING HOURS ON SATURDAY. A DOWNSLOPE FLOW FURTHER
EAST TONIGHT SHOULD KEEP CEILINGS AT ROA/LYH/DAN FROM DROPPING BELOW
3KFT DURING THE EARLY MORNING HOURS...ALTHOUGH LIGHT RAIN EARLIER
THIS EVENING MAY CAUSE LIGHT FOG TO DEVELOP BEFORE SUNRISE. BY 15Z
SATURDAY ALL TAF LOCATIONS WILL RETURN TO VFR CONDITIONS AS DAYTIME
HEATING INCREASES...ERODING THE REMAINING LOW CLOUDS.

A DEVELOPING LOW PRESSURE SYSTEM ACROSS EASTERN CANADA WILL KEEP OUR
REGION UNSETTLED THROUGH THE EARLY PART OF NEXT WEEK. VFR CONDITIONS
ARE EXPECTED FOR THE MAJORITY OF THE PERIOD...WITH ISOLATED IFR/MVFR
CONDITIONS POSSIBLE WHERE SHOWERS AND THUNDERSTORMS DEVELOP.

&&

.EQUIPMENT...
KFCX RADAR IS BACK UP AND RUNNING...BUT MAY GO DOWN AGAIN
TONIGHT. PROBLEMS WITH KLYSTRON BLOWER MOTOR. PARTS ON ORDER.
ESTIMATED REPLACEMENT OF PART AFTER DELIVERY ON SATURDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...DS/KK/RAB
NEAR TERM...DS/KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...CF/KK/NF
EQUIPMENT...







AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 855 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST CROSS THE REGION THIS EVENING
INTO TONIGHT ACCOMPANIED BY SHOWERS AND THUNDERSTORMS. DEEPENING
LOW PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS
THE EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK.
A SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 715 PM EDT FRIDAY...

HAVE TRIMMED BACK PRECIPITATION CHANCES BASED UPON THE LATEST
TRENDS OF KFCX AND OTHER NEIGHBORING 88D RADARS. FIRST LINE OF
CONVECTION WILL BE EAST OF THE FORECAST AREA BY 800 PM. NEXT LINE
OF PRECIPITATION WILL BE ASSOCIATED WITH THE ACTUAL COLD FRONT.
RADARS ARE SHOWING AN ISOLATED TO SCATTERED COVERAGE WITH THIS
ACTIVITY. ANTICIPATE CONVERAGE TO BE OF A SIMILAR OR LESS COVERAGE
AS THE FRONT HEADS EAST AND ENCOUNTERS THE RELATIVELY STABLE AREA
ACROSS THE REGION...ESPECIALLY WITH THE SOON LOSS OF SUNSHINE.
HAVE ALSO ADJUSTED TEMPERATURE...DEW POINT...AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
EVENING.

AS 310 PM EDT FRIDAY...

SFC COLD FRONT LOCATED TO OUR WEST FROM WESTERN PENNSYLVANIA
SOUTHWARD TO EASTERN KY. THIS FRONT WILL MOVE SOUTHEAST TONIGHT INTO
SATURDAY. CONVECTION COVERAGE SHOULD INCREASE LATE THIS AFTERNOON
INTO TONIGHT...DUE TO COMBINATION OF DIFFERENTIAL HEATING EFFECTS
AND THE APPROACH OF COLD FRONT/MID-LEVEL SHORT WAVE TROUGH. AT THIS
TIME...REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED
THUNDERSTORMS MOVING EAST ACROSS WESTERN PORTIONS OF CWA. LOOKS LIKE
THE BEST INSTABILITY IS JUST AHEAD OF THE CLOUD DECK. SPC RECENTLY
REMOVED MUCH OF THE AREA FROM THEIR SLIGHT RISK...AND THIS SEEMS
REASONABLE...ESPECIALLY IN LIGHT OF THE WEAK SHEAR OVER THE REGION.
AN ISOLATED STRONG TO SEVERE THUNDERSTORM MAY BE POSSIBLE THIS
EVENING WITH MAIN THREAT HEAVY RAINS AND GUSTY WINDS.

THUNDERSTORMS AND SHOWERS SHOULD WANE/DIMINISH TONIGHT AS THE
UPPER SHORT WAVE SHEARS OUT AND THE MAIN DYNAMICS MOVE TOWARD NEW
ENGLAND.  ANOTHER SHORTWAVE POISED THE MOVE ACROSS THE UPPER
MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG SW FLOW ALOFT AND
DELAY ANY CLEARING. WITH PLENTY OF CLOUDS TONIGHT...PLAYED LOW
TEMPERATURES CLOSE TO THE ADJMET WITH READINGS FROM AROUND 60
DEGREES IN THE MOUNTAINS TO THE UPPER 60S TO NEAR 70 IN THE
SOUTHEAST.

THE COLD FRONT WILL MOVE SOUTH INTO NORTH CAROLINA FOR SATURDAY.
THERE IS ENOUGH MOISTURE TO COMBINED WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW THUNDERSTORMS. HIGH TEMPERATURES ON SATURDAY WILL VARY THE MID
70S IN THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EDT FRIDAY...

COLD FRONT WILL BE DOWN IN THE CAROLINAS BY SAT NIGHT WITH DRIER AND
COOLER AIR SEEPING SOUTHBOUND ALLOWING FOR AN EXODUS OF MOST
LEFTOVER SHRA OVER THE SOUTH SAT EVENING. NEXT MID LEVEL IMPULSE
PROGGED BY MOST MODELS WILL ROUND THE 5H TROF SLIDING THRU THE UPPER
MIDWEST SUNDAY AND DAMPEN UPON PASSING INTO THE OHIO VALLEY SUNDAY
NIGHT. DEEPER MOISTURE WITH THE RESIDUAL FRONT LOOKS TO REMAIN JUST
SOUTH OF THE CWA THOUGH AS OVERALL MID LEVEL BACKING OF THE FLOW
AHEAD OF THE WAVE APPEARS WEAK ATTM. HOWEVER WITH LOW LEVEL
TRAJECTORIES TURNING MORE SOUTH/SE AND A RIBBON OF HIGHER SFC-85H
THETA-E SPREADING ALONG/EAST OF THE BLUE RIDGE...WENT AHEAD AND
EXPANDED THE CHANCE POPS NORTH SUNDAY/SUNDAY EVENING...WITH BEST
COVERAGE SOUTHERN HALF WHERE SOME CAPE WILL EXIST. SHRA MAY LINGER
EAST SUNDAY NIGHT AND BUBBLE BACK TO THE WEST ON MONDAY AS YET
ANOTHER UPPER LEVEL DISTURBANCE SPINS BY AND PERHAPS INDUCES A SFC
WAVE ALONG THE FRONT TO THE SOUTH MONDAY AFTERNOON PER THE LASTEST
CANADIAN. AGAIN MAINLY MIDDLE RANGE CHANCE POPS FOR NOW GIVEN
UNCERTAINTY AND ONLY SLIGHT POPS FAR WEST/NW WHERE REMOVED FROM THE
DEEPER RH. OTRW MORE CLOUDS SOUTH/EAST AND PERHAPS MORE
BREAKS/CLEARING AT TIMES NORTH-NW THRU MONDAY. CLOUDS/SHRA SHOULD
KEEP HIGHS MAINLY IN THE 70S TO LOW 80S WITH LOWS 50S TO LOW 60S
MOUNTAINS...AND 60-65 BEHIND THE FRONT OUT EAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...

UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 830 PM EDT FRIDAY...

SHOWERS AND THUNDERSTORMS HAVE MAINLY EXITED THE REGION AS OF 00Z.
THE EXCEPTION IS SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS WESTERN
VIRGINIA AS A WEAK DISTURBANCE PASSES BY. LEFT A CHANCE OF RAIN AT
BLF THROUGH 02Z. THE HRRR FORECAST MODEL SHOWS ANY SHOWERS THAT
DEVELOP ALONG THE COLD FRONT WILL DISSIPATE EAST OF THE BLUE RIDGE
TONIGHT THANKS TO THE NORTHWESTERLY DOWNSLOPE FLOW.

WESTERLY FLOW WILL PROMOTE LOW CEILINGS AT LWB AND BLF...AND
POSSIBLY FOR A SHORT TIME AT BCB...IFR CONDITIONS ARE EXPECTED
DURING THE EARLY MORNING HOURS ON SATURDAY. A DOWNSLOPE FLOW FURTHER
EAST TONIGHT SHOULD KEEP CEILINGS AT ROA/LYH/DAN FROM DROPPING BELOW
3KFT DURING THE EARLY MORNING HOURS...ALTHOUGH LIGHT RAIN EARLIER
THIS EVENING MAY CAUSE LIGHT FOG TO DEVELOP BEFORE SUNRISE. BY 15Z
SATURDAY ALL TAF LOCATIONS WILL RETURN TO VFR CONDITIONS AS DAYTIME
HEATING INCREASES...ERODING THE REMAINING LOW CLOUDS.

A DEVELOPING LOW PRESSURE SYSTEM ACROSS EASTERN CANADA WILL KEEP OUR
REGION UNSETTLED THROUGH THE EARLY PART OF NEXT WEEK. VFR CONDITIONS
ARE EXPECTED FOR THE MAJORITY OF THE PERIOD...WITH ISOLATED IFR/MVFR
CONDITIONS POSSIBLE WHERE SHOWERS AND THUNDERSTORMS DEVELOP.

&&

.EQUIPMENT...
KFCX RADAR IS BACK UP AND RUNNING...BUT MAY GO DOWN AGAIN
TONIGHT. PROBLEMS WITH KLYSTRON BLOWER MOTOR. PARTS ON ORDER.
ESTIMATED REPLACEMENT OF PART AFTER DELIVERY ON SATURDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...KK/RAB
NEAR TERM...DS/KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...CF/KK/NF
EQUIPMENT...







AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 718 PM EDT FRI AUG 17 2012

.SYNOPSIS...
A COLD FRONT WILL MOVE SOUTHEAST CROSS THE REGION THIS EVENING
INTO TONIGHT ACCOMPANIED BY SHOWERS AND THUNDERSTORMS. DEEPENING
LOW PRESSURE...ANCHORED OVER SOUTHEAST CANADA...WILL EVOLVE ACROSS
THE EASTERN U.S. FOR THE WEEKEND INTO THE FIRST HALF OF NEXT WEEK.
A SERIES OF DISTURBANCES EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 715 PM EDT FRIDAY...

HAVE TRIMMED BACK PRECIPITATION CHANCES BASED UPON THE LATEST
TRENDS OF KFCX AND OTHER NEIGHBORING 88D RADARS. FIRST LINE OF
CONVECTION WILL BE EAST OF THE FORECAST AREA BY 800 PM. NEXT LINE
OF PRECIPITATION WILL BE ASSOCIATED WITH THE ACTUAL COLD FRONT.
RADARS ARE SHOWING AN ISOLATED TO SCATTERED COVERAGE WITH THIS
ACTIVITY. ANTICIPATE CONVERAGE TO BE OF A SIMILAR OR LESS COVERAGE
AS THE FRONT HEADS EAST AND ENCOUNTERS THE RELATIVELY STABLE AREA
ACROSS THE REGION...ESPECIALLY WITH THE SOON LOSS OF SUNSHINE.
HAVE ALSO ADJUSTED TEMPERATURE...DEW POINT...AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
EVENING.

AS 310 PM EDT FRIDAY...

SFC COLD FRONT LOCATED TO OUR WEST FROM WESTERN PENNSYLVANIA
SOUTHWARD TO EASTERN KY. THIS FRONT WILL MOVE SOUTHEAST TONIGHT INTO
SATURDAY. CONVECTION COVERAGE SHOULD INCREASE LATE THIS AFTERNOON
INTO TONIGHT...DUE TO COMBINATION OF DIFFERENTIAL HEATING EFFECTS
AND THE APPROACH OF COLD FRONT/MID-LEVEL SHORT WAVE TROUGH. AT THIS
TIME...REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED
THUNDERSTORMS MOVING EAST ACROSS WESTERN PORTIONS OF CWA. LOOKS LIKE
THE BEST INSTABILITY IS JUST AHEAD OF THE CLOUD DECK. SPC RECENTLY
REMOVED MUCH OF THE AREA FROM THEIR SLIGHT RISK...AND THIS SEEMS
REASONABLE...ESPECIALLY IN LIGHT OF THE WEAK SHEAR OVER THE REGION.
AN ISOLATED STRONG TO SEVERE THUNDERSTORM MAY BE POSSIBLE THIS
EVENING WITH MAIN THREAT HEAVY RAINS AND GUSTY WINDS.

THUNDERSTORMS AND SHOWERS SHOULD WANE/DIMINISH TONIGHT AS THE
UPPER SHORT WAVE SHEARS OUT AND THE MAIN DYNAMICS MOVE TOWARD NEW
ENGLAND.  ANOTHER SHORTWAVE POISED THE MOVE ACROSS THE UPPER
MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG SW FLOW ALOFT AND
DELAY ANY CLEARING. WITH PLENTY OF CLOUDS TONIGHT...PLAYED LOW
TEMPERATURES CLOSE TO THE ADJMET WITH READINGS FROM AROUND 60
DEGREES IN THE MOUNTAINS TO THE UPPER 60S TO NEAR 70 IN THE
SOUTHEAST.

THE COLD FRONT WILL MOVE SOUTH INTO NORTH CAROLINA FOR SATURDAY.
THERE IS ENOUGH MOISTURE TO COMBINED WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW THUNDERSTORMS. HIGH TEMPERATURES ON SATURDAY WILL VARY THE MID
70S IN THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EDT FRIDAY...

COLD FRONT WILL BE DOWN IN THE CAROLINAS BY SAT NIGHT WITH DRIER AND
COOLER AIR SEEPING SOUTHBOUND ALLOWING FOR AN EXODUS OF MOST
LEFTOVER SHRA OVER THE SOUTH SAT EVENING. NEXT MID LEVEL IMPULSE
PROGGED BY MOST MODELS WILL ROUND THE 5H TROF SLIDING THRU THE UPPER
MIDWEST SUNDAY AND DAMPEN UPON PASSING INTO THE OHIO VALLEY SUNDAY
NIGHT. DEEPER MOISTURE WITH THE RESIDUAL FRONT LOOKS TO REMAIN JUST
SOUTH OF THE CWA THOUGH AS OVERALL MID LEVEL BACKING OF THE FLOW
AHEAD OF THE WAVE APPEARS WEAK ATTM. HOWEVER WITH LOW LEVEL
TRAJECTORIES TURNING MORE SOUTH/SE AND A RIBBON OF HIGHER SFC-85H
THETA-E SPREADING ALONG/EAST OF THE BLUE RIDGE...WENT AHEAD AND
EXPANDED THE CHANCE POPS NORTH SUNDAY/SUNDAY EVENING...WITH BEST
COVERAGE SOUTHERN HALF WHERE SOME CAPE WILL EXIST. SHRA MAY LINGER
EAST SUNDAY NIGHT AND BUBBLE BACK TO THE WEST ON MONDAY AS YET
ANOTHER UPPER LEVEL DISTURBANCE SPINS BY AND PERHAPS INDUCES A SFC
WAVE ALONG THE FRONT TO THE SOUTH MONDAY AFTERNOON PER THE LASTEST
CANADIAN. AGAIN MAINLY MIDDLE RANGE CHANCE POPS FOR NOW GIVEN
UNCERTAINTY AND ONLY SLIGHT POPS FAR WEST/NW WHERE REMOVED FROM THE
DEEPER RH. OTRW MORE CLOUDS SOUTH/EAST AND PERHAPS MORE
BREAKS/CLEARING AT TIMES NORTH-NW THRU MONDAY. CLOUDS/SHRA SHOULD
KEEP HIGHS MAINLY IN THE 70S TO LOW 80S WITH LOWS 50S TO LOW 60S
MOUNTAINS...AND 60-65 BEHIND THE FRONT OUT EAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...

UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH MAINLY
DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.

&&

.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
AS OF 105 PM EDT FRIDAY...

MAIN FOCUS FOR TAF VALID PERIOD IS CHANCE FOR CONVECTION THIS
AFTERNOON/EVENING. REGIONAL WSR-88D LOOP SHOWED SCATTERED SHOWERS
AND ISOLATED THUNDERSTORMS MOVING EAST ACROSS THE WESTERN MOUNTAINS.
LOOKS LIKE THE BEST INSTABILITY JUST IN FRONT OF THE CLOUD BLANKET.
COLD FRONT LOCATED TO OUR WEST ALONG THE OHIO RIVER WILL MOVE EAST
ACROSS OUR REGION WITH SCATTERED MVFR SHOWERS AND THUNDERSTORM.
LOCAL IFR CONDITIONS AND GUSTY WINDS POSSIBLE WITH A STRONGER
STORM. ACCORDING TO THE HRRR AND LOCAL WRFARW-RNK LOOKS LIKE THE
BEST CHANCE FOR A THUNDERSTORM MAY BE AT BLF OR DAN. HOWEVER
THUNDERSTORMS ARE POSSIBLE AT ALL TAF SITES THIS AFTERNOON INTO
TONIGHT WITH COLD FRONT MOVING ACROSS THE REGION.

ANOTHER CONCERN IS WHETHER OR NOT CLOUDS/PCPN WILL EXIT THE AREA...OR
BUILD BACK NORTHWARD OVERNIGHT IN WAKE OF INITIAL WAVE OF
SHRA/TSRA. KEPT MVFR CLOUDS-CIGS AND MVFR-IFR VSBYS IN -RA/-SHRA/-DZ AFT
08Z. THINKING IS THAT -SHRA WILL GENERALLY BE CONFINED TO PIEDMONT
REGION...BUT UPSLOPE FLOW AND PASSING WAVE ALONG FRONT TO THE
SOUTH COULD PROMOTE DEVELOPMENT OF LOW CLOUDS AND -DZ BLF-LWB AFT
08Z SAT. WINDS REMAIN W-NW THROUGH TAF VALID PERIOD...BUT WILL BE
VEERING OVER TO NE NEAR 12Z SAT...WHICH WILL FURTHER PROMOTE
DEVELOPMENT OF LOW CLOUDS AND FOG...ESPECIALLY ACROSS THE PIEDMONT
REGION.

EXTENDED AVIATION DISCUSSION...

THE FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE
WEEKEND...WHILE HIGH PRESSURE PASSES EASTWARD TO THE SOUTH OF THE
GREAT LAKES. EXPECT MOST OF THE AREA TO REMAIN DRY ON
SATURDAY...HOWEVER WIDELY SCATTERED SHOWERS AND THUNDERSTORMS WILL
DEVELOP MAINLY ACROSS THE MOUNTAINS WITH AFTERNOON HEATING FROM
SUNDAY INTO THE MIDDLE OF NEXT WEEK.

&&

.EQUIPMENT...
KFCX RADAR IS BACK UP AND RUNNING...BUT MAY GO DOWN AGAIN
TONIGHT. PROBLEMS WITH KLYSTRON BLOWER MOTOR. PARTS ON ORDER.
ESTIMATED REPLACEMENT OF PART AFTER DELIVERY ON SATURDAY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...KK/RAB
NEAR TERM...DS/KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...KK/RAB
EQUIPMENT...







AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 340 AM EDT THU AUG 16 2012

.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS IN OVERNIGHT ALLOWING FOR DRIER WEATHER
INTO THURSDAY. ANOTHER FRONT IMPACTS THE REGION FRIDAY INTO THE
WEEKEND WITH A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY FRIDAY THROUGH SATURDAY ALONG WITH
SEASONABLY MILD TEMPERATURES.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 345 AM EDT THURSDAY...

NO SIGNIFICANT CHANGES AT THIS TIME. DENSE FOG FORMING IN THE RIVER
VALLEYS...OTHERWISE MOSTLY CLEAR AT THIS TIME. ONLY MINOR
MODIFICATIONS TO T/TD GRIDS. POPS ARE NIL AND WILL REMAIN SO FOR THE
NEXT 18 HRS OR SO.

AS OF 1010 PM EDT WEDNESDAY...

LOOKS LIKE THE LAST OF THE SHRA FINALLY FADING ACROSS THE EAST
WITH PERHAPS STILL AN ISOLATED SHRA TO AFFECT LYNCHBURG BEFORE
PRECIP ENDS WITH LOSS OF HEATING/INSTABILITY. HOWEVER SOME LOW
CLOUDS CONTINUE TO LINGER EAST OF THE BLUE RIDGE IN VIRGINIA AND
REMAIN BANKED UP WITH UPSLOPE FLOW AROUND BLUEFIELD SO UPDATING TO
INCLUDE MORE CLOUDS EARLY ON. OTRW ARRIVAL OF VERY DRY AIR ALOFT
PER VAPOR LOOP/EVENING RAOBS IN CONJUNCTION WITH HIGH PRESSURE
BUILDING IN FROM THE WEST SHOULD MAKE FOR MAINLY CLEAR SKIES AND
MORE COMFORTABLE TEMPS AFTER MIDNIGHT AS DRIER AIR SEEPS IN. SOME
FOG AGAIN LIKELY ESPCLY VALLEYS AND WHERE SPOTTY HEAVIER DOWNPOURS
OCCURRED EARLIER SO TWEAKING COVERAGE A LITTLE. BASICALLY LEAVING
TEMPS CLOSE TO PREVIOUS EXCEPT NUDGING UP SLIGHTLY IN THE EAST
WHERE DRIER AIR WILL BE SLOWER TO ARRIVE. OTRW LOWS MAINLY IN THE
COOLER 50S MOUNTAINS TO 60-65 EAST ON TRACK.

AS OF 605 PM EDT WEDNESDAY...

EVENING UPDATE TO LOWER POPS ACROSS THE FAR SOUTH AS DEEPER
CONVECTION ACROSS CENTRAL NC HAS TAKEN BETTER LIFT FARTHER SOUTH.
HOWEVER BUMPED UP COVERAGE A BIT OVER THE NE PER LEFTOVER BAND OF
SHRA/TSRA HEADING DOWN JUST EAST OF THE BLUE RIDGE AND OVER THE NW
JUST AHEAD OF THE ACTUAL DEWPOINT FRONT. APPEARS ENOUGH
INSTABILITY OVER THE NE TO PROMOTE SOME ISOLATED TSRA SO KEPT
MENTION THERE WITH MAINLY SHRA ELSW. THIS BOUNDARY SHOULD PUSH
THRU THE MOUNTAINS OVER THE NEXT FEW HOURS AND THE REST OF THE CWA
THIS EVENING BEHIND THE PASSING UPPER VORT. GOOD SUBSIDENCE BEHIND
THIS FEATURE SHOULD BRING AN END TO ANY REMAINING SHRA WITH LOSS
OF HEATING SO ONLY ISOLATED POPS AT BEST ELSW THIS EVENING.

PREVIOUS DISCUSSION AS OF 325 PM EDT WEDNESDAY...

MAIN SHORTWAVE IS STARTING TO MOVE INTO NRN VA ATTM...WITH PIECES OF
VORT ENERGY OCCURRING ALONG THE BACK EDGE OF THE DEEPER MOISTURE
ACROSS THE SOUTHERN APPALACHIANS INTO SRN WV. STILL APPEARS THE NEAR
TERM MESOSCALE MODELS HOLD CONVECTION THAT IS OCCURRING OVER THE
CENTRAL PORTION OF OUR FORECAST AREA EAST INTO THE PIEDMONT FOR LATE
AFTERNOON. FOLLOWED THE LATEST HRRR EXCEPT SLOWED ITS TIMING DOWN
GIVEN SPEED OF ECHOES ON RADAR BEING SLOWER. ATTM...THINK WILL SEE
THUNDER THREAT PUSHING EAST OF THE BLUE RIDGE SOON....THEN SHOULD
EXPECT SHOWERS TO WIND DOWN AND DISSIPATE AFTER 00Z. SOME CLEARING
AHEAD OF THE VORT LOBE MAY CREATE ENOUGH INSTABILITY THAT A FEW
CELLS COULD BE STRONG TO EVEN SEVERE WITH DAMAGING WINDS POSSIBLE.
CURRENT ANALYSIS SUGGESTS THE GREATEST POTENTIAL FOR THIS WILL BE
SOUTHEAST OF OUR CWA...BUT THOSE AREAS SOUTH OF HIGHWAY 58 FROM
DANVILLE TO SOUTH BOSTON INTO NC MAY BE IN A BETTER ENVIRONMENT FOR
THIS.

AFTER THE ACTIVITY WANES TONIGHT...SKIES SHOULD CLEAR AND SOME FOG
WILL FORM ESPECIALLY WHERE IT RAINED...BUT OVERALL KEPT IT IN THE
MTNS. WILL SEE JUST ENOUGH DRY AIR TO LOWER TEMPS SOME
TONIGHT...CLOSER TO LOCAL MOS WITH MID 50S MTNS TO LOWER 60S
SOUTHEAST.

FLOW WILL BACK AGAIN TO THE SOUTHWEST THU AFTERNOON WITH RISING
HEIGHTS. HIGHS WILL BE WARM ESPECIALLY EAST WITH NEAR 90...WHILE THE
MTNS STAY IN THE LOWER 80S.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 PM WEDNESDAY...

UPPER AIR PATTERN BECOMES AMPLIFIED FOR THE WEEKS END WITH RIDGE
OVER THE ROCKIES AND TROUGH IN THE EAST.  DEEPER TROUGHING IN THE
EAST WILL BE PRECEDED BY WEAK RIDGING THURSDAY NIGHT AND EARLY
FRIDAY AHEAD OF SURFACE COLD FRONT THAT WILL BE MOVING THROUGH THE
OHIO VALLEY. WITH 85H TEMPS +18 DEG C...SHOULD SEE SPIKE IN
TEMPERATURE PRIOR TO FROPA FRIDAY EVENING.  CLOUD INCREASE AHEAD OF
FRONT SHOULD KEEP TEMPS IN THE MTNS IN THE 70S...BUT NEAR FULL
INSOLATION EAST OF MTNS WILL LIKELY PERMIT TEMPS TO TEST 90 EAST
OF THE BLUE RIDGE.  HIGHEST POPS FRIDAY ANTICIPATED IN THE
MTNS...SHRA/TSRA DEVELOPING IN ADV OF FRONT AND MOVING ACROSS THE
CWA DURING THE LATE AFTERNOON AND EVENING.

MODELS SLOW PROGRESSION OF FRONT AS IT CROSSES THE CWA...THUS CLOUDS
AND PRECIP THREAT MAY LINGER INTO SATURDAY.  NOT OVERLY EXCITED
ABOUT INSTABILITY SATURDAY PER LINGERING CLOUD COVER...THUS THINK
ANY PRECIP SATURDAY WOULD BE IN THE FORM OF SHOWERS AND LITTLE OR NO
THUNDER.   FRONT IS FCST TO DISSIPATE OVER OR JUST SOUTH OF THE AREA
SATURDAY NIGHT...AMOUNT OF CLEARING DEPENDENT ON FRONTAL REMNANTS.
TEMPERATURES SATURDAY WILL BE TEMPERED BY CLOUD COVER...L-M 70S
MTS...LOWER 80S PIEDMONT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 350 PM WEDNESDAY...

UPPER LEVEL TROUGH SETS UP SHOP OVER THE ERN CONUS FOR NEXT WEEK.
FLOW ALOFT REMAINS CYCLONIC WITH EMBEDDED SHORT WAVE ENERGY HELPING
TO KEEP THE FLOW AMPLIFIED.  PRESENCE OF THE TROUGH SUGGESTS TEMPS
WILL RUN BLO MEDIAN.  AS FOR PRECIP...A LOT WILL DEPEND ON THE
AMOUNT OF RETURN FLOW THAT CAN DEVELOP AND TIMING OF ANY SHORT WAVE
ENERGY. FOR NOW WILL FOCUS HIGHEST POPS VCNTY OF MTNS WHERE LOW
LEVEL CONVERGENCE WILL BE GREATEST...ALTHOUGH COOLER THAN NORMAL
TEMPS SUGGESTS INSTABILITY WILL BE MAINLY DIURNALLY DRIVEN.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 150 AM EDT THURSDAY...

FORECAST AREA CURRENTLY IN BETWEEN WEATHER SYSTEMS...WITH THE SHORT
WAVE OF WEDNESDAY HAVING PASSED OFF TO THE EAST AND ANOTHER STRONGER
UPPER LOW PRESSURE SYSTEM APPROACHING FROM THE WEST FOR FRI INTO THE
WEEKEND. PRIOR TO 14Z...THERE WILL BE POCKETS OF IFR-LIFR
VSBYS/CIGS...MAINLY IN THE USUALLY FAVORED SPOTS FOR SUCH...NAMELY
LWB...BLF...AND BCB. WILL NEED TO WATCH LYH FOR SUCH LATER AS WELL.
CALM WINDS AND MOIST GROUND FROM WIDESPREAD -RA WED WILL PROMOTE
RADIATIONAL FOG DEVELOPMENT OVERNIGHT. ALREADY OBSERVING IFR-LIFR
VSBYS/CIGS AT BLF. AFT 14Z...EXPECT VFR CIGS/VSBYS THROUGHOUT
REMAINDER OF TAF VALID PERIOD WITH ONLY A FEW FAIR WEATHER CU
EXPECTED AOA 050. WINDS CHAOTIC AND LIGHT THROUGHOUT TAF VALID
PERIOD...FAVORING A LIGHT WNW DIRECTION THROUGH MID-DAY...THEN
MOSTLY VRB03-04KT FOR THE REMAINDER OF TAF VALID PERIOD.

AS OF 650 PM EDT WEDNESDAY...

FEW SHOWERS REMAIN ACROSS THE NE BUT EXPECT FURTHER DISSIPATION WITH
LOSS OF HEATING SO THINKING MAY BE ABLE TO RUN WITHOUT ANY PRECIP
MENTION TO INIT AT MOST TAF SITES OUTSIDE OF KLYH THIS EVENING.
WAVE EXITS BY MIDNIGHT WITH DECENT SUBSIDENCE SPILLING EAST
ALLOWING FOR CLEARING SKIES AND SLOWLY FALLING DEWPOINTS. HOWEVER
APPEARS ENOUGH LOW LEVEL MOISTURE MAY LINGER LONG ENOUGH TO CAUSE
FOG FORMATION IN THE VALLEYS AND IN SPOTS NEAR WHERE EARLIER RAIN
OCCURRED ESPCLY KDAN. LOW CIGS MAY ALSO BANK UP AROUND KBLF
OVERNIGHT GIVEN WEAK NW FLOW WITH MVFR/IFR FOG LIKELY. OTRW
THINKING LIFR IN FOG/STRATUS AT KLWB AND MAINLY MVFR KBCB/KDAN AND
PERHAPS KLYH.

ANY FOG AND/OR LOW CLOUDS SHOULD HAVE ERODED BY MID MORNING
THURSDAY WITH HIGH PRESSURE PROVIDING FOR VFR UNDER FEW/SCTD CU
INTO THE AFTERNOON UNDER LIGHT WINDS.

ASIDE FROM SOME LATE NIGHT FOG AT LWB/BCB ANTICIPATE THE NEXT
THREAT FOR SUB VFR TO COME WITH A FRONT FRIDAY INTO SATURDAY. THE
FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE WEEKEND
SUCH THAT THE THREAT OF SHOWERS MAY OCCUR ACROSS SOUTHERN
SECTIONS...WITH SOME MVFR POSSIBLE. THE FRONT WILL BE MOVING SLOWLY
EAST BY MONDAY AS HIGH PRESSURE WORKS IN FROM THE OHIO VALLEY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...RAB/JH/WP
SHORT TERM...PM
LONG TERM...PM
AVIATION...RAB/JH/WP













AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 150 AM EDT THU AUG 16 2012

.SYNOPSIS...
WEAK HIGH PRESSURE BUILDS IN OVERNIGHT ALLOWING FOR DRIER WEATHER
INTO THURSDAY. ANOTHER FRONT IMPACTS THE REGION FRIDAY INTO THE
WEEKEND WITH A BETTER CHANCE FOR SHOWERS AND
THUNDERSTORMS...ESPECIALLY FRIDAY THROUGH SATURDAY ALONG WITH
SEASONABLY MILD TEMPERATURES.

&&

.NEAR TERM /THROUGH THURSDAY/...
AS OF 1010 PM EDT WEDNESDAY...

LOOKS LIKE THE LAST OF THE SHRA FINALLY FADING ACROSS THE EAST
WITH PERHAPS STILL AN ISOLATED SHRA TO AFFECT LYNCHBURG BEFORE
PRECIP ENDS WITH LOSS OF HEATING/INSTABILITY. HOWEVER SOME LOW
CLOUDS CONTINUE TO LINGER EAST OF THE BLUE RIDGE IN VIRGINIA AND
REMAIN BANKED UP WITH UPSLOPE FLOW AROUND BLUEFIELD SO UPDATING TO
INCLUDE MORE CLOUDS EARLY ON. OTRW ARRIVAL OF VERY DRY AIR ALOFT
PER VAPOR LOOP/EVENING RAOBS IN CONJUNCTION WITH HIGH PRESSURE
BUILDING IN FROM THE WEST SHOULD MAKE FOR MAINLY CLEAR SKIES AND
MORE COMFORTABLE TEMPS AFTER MIDNIGHT AS DRIER AIR SEEPS IN. SOME
FOG AGAIN LIKELY ESPCLY VALLEYS AND WHERE SPOTTY HEAVIER DOWNPOURS
OCCURRED EARLIER SO TWEAKING COVERAGE A LITTLE. BASICALLY LEAVING
TEMPS CLOSE TO PREVIOUS EXCEPT NUDGING UP SLIGHTLY IN THE EAST
WHERE DRIER AIR WILL BE SLOWER TO ARRIVE. OTRW LOWS MAINLY IN THE
COOLER 50S MOUNTAINS TO 60-65 EAST ON TRACK.

AS OF 605 PM EDT WEDNESDAY...

EVENING UPDATE TO LOWER POPS ACROSS THE FAR SOUTH AS DEEPER
CONVECTION ACROSS CENTRAL NC HAS TAKEN BETTER LIFT FARTHER SOUTH.
HOWEVER BUMPED UP COVERAGE A BIT OVER THE NE PER LEFTOVER BAND OF
SHRA/TSRA HEADING DOWN JUST EAST OF THE BLUE RIDGE AND OVER THE NW
JUST AHEAD OF THE ACTUAL DEWPOINT FRONT. APPEARS ENOUGH
INSTABILITY OVER THE NE TO PROMOTE SOME ISOLATED TSRA SO KEPT
MENTION THERE WITH MAINLY SHRA ELSW. THIS BOUNDARY SHOULD PUSH
THRU THE MOUNTAINS OVER THE NEXT FEW HOURS AND THE REST OF THE CWA
THIS EVENING BEHIND THE PASSING UPPER VORT. GOOD SUBSIDENCE BEHIND
THIS FEATURE SHOULD BRING AN END TO ANY REMAINING SHRA WITH LOSS
OF HEATING SO ONLY ISOLATED POPS AT BEST ELSW THIS EVENING.

PREVIOUS DISCUSSION AS OF 325 PM EDT WEDNESDAY...

MAIN SHORTWAVE IS STARTING TO MOVE INTO NRN VA ATTM...WITH PIECES OF
VORT ENERGY OCCURRING ALONG THE BACK EDGE OF THE DEEPER MOISTURE
ACROSS THE SOUTHERN APPALACHIANS INTO SRN WV. STILL APPEARS THE NEAR
TERM MESOSCALE MODELS HOLD CONVECTION THAT IS OCCURRING OVER THE
CENTRAL PORTION OF OUR FORECAST AREA EAST INTO THE PIEDMONT FOR LATE
AFTERNOON. FOLLOWED THE LATEST HRRR EXCEPT SLOWED ITS TIMING DOWN
GIVEN SPEED OF ECHOES ON RADAR BEING SLOWER. ATTM...THINK WILL SEE
THUNDER THREAT PUSHING EAST OF THE BLUE RIDGE SOON....THEN SHOULD
EXPECT SHOWERS TO WIND DOWN AND DISSIPATE AFTER 00Z. SOME CLEARING
AHEAD OF THE VORT LOBE MAY CREATE ENOUGH INSTABILITY THAT A FEW
CELLS COULD BE STRONG TO EVEN SEVERE WITH DAMAGING WINDS POSSIBLE.
CURRENT ANALYSIS SUGGESTS THE GREATEST POTENTIAL FOR THIS WILL BE
SOUTHEAST OF OUR CWA...BUT THOSE AREAS SOUTH OF HIGHWAY 58 FROM
DANVILLE TO SOUTH BOSTON INTO NC MAY BE IN A BETTER ENVIRONMENT FOR
THIS.

AFTER THE ACTIVITY WANES TONIGHT...SKIES SHOULD CLEAR AND SOME FOG
WILL FORM ESPECIALLY WHERE IT RAINED...BUT OVERALL KEPT IT IN THE
MTNS. WILL SEE JUST ENOUGH DRY AIR TO LOWER TEMPS SOME
TONIGHT...CLOSER TO LOCAL MOS WITH MID 50S MTNS TO LOWER 60S
SOUTHEAST.

FLOW WILL BACK AGAIN TO THE SOUTHWEST THU AFTERNOON WITH RISING
HEIGHTS. HIGHS WILL BE WARM ESPECIALLY EAST WITH NEAR 90...WHILE THE
MTNS STAY IN THE LOWER 80S.

&&

.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 PM WEDNESDAY...

UPPER AIR PATTERN BECOMES AMPLIFIED FOR THE WEEKS END WITH RIDGE
OVER THE ROCKIES AND TROUGH IN THE EAST.  DEEPER TROUGHING IN THE
EAST WILL BE PRECEDED BY WEAK RIDGING THURSDAY NIGHT AND EARLY
FRIDAY AHEAD OF SURFACE COLD FRONT THAT WILL BE MOVING THROUGH THE
OHIO VALLEY. WITH 85H TEMPS +18 DEG C...SHOULD SEE SPIKE IN
TEMPERATURE PRIOR TO FROPA FRIDAY EVENING.  CLOUD INCREASE AHEAD OF
FRONT SHOULD KEEP TEMPS IN THE MTNS IN THE 70S...BUT NEAR FULL
INSOLATION EAST OF MTNS WILL LIKELY PERMIT TEMPS TO TEST 90 EAST
OF THE BLUE RIDGE.  HIGHEST POPS FRIDAY ANTICIPATED IN THE
MTNS...SHRA/TSRA DEVELOPING IN ADV OF FRONT AND MOVING ACROSS THE
CWA DURING THE LATE AFTERNOON AND EVENING.

MODELS SLOW PROGRESSION OF FRONT AS IT CROSSES THE CWA...THUS CLOUDS
AND PRECIP THREAT MAY LINGER INTO SATURDAY.  NOT OVERLY EXCITED
ABOUT INSTABILITY SATURDAY PER LINGERING CLOUD COVER...THUS THINK
ANY PRECIP SATURDAY WOULD BE IN THE FORM OF SHOWERS AND LITTLE OR NO
THUNDER.   FRONT IS FCST TO DISSIPATE OVER OR JUST SOUTH OF THE AREA
SATURDAY NIGHT...AMOUNT OF CLEARING DEPENDENT ON FRONTAL REMNANTS.
TEMPERATURES SATURDAY WILL BE TEMPERED BY CLOUD COVER...L-M 70S
MTS...LOWER 80S PIEDMONT.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 350 PM WEDNESDAY...

UPPER LEVEL TROUGH SETS UP SHOP OVER THE ERN CONUS FOR NEXT WEEK.
FLOW ALOFT REMAINS CYCLONIC WITH EMBEDDED SHORT WAVE ENERGY HELPING
TO KEEP THE FLOW AMPLIFIED.  PRESENCE OF THE TROUGH SUGGESTS TEMPS
WILL RUN BLO MEDIAN.  AS FOR PRECIP...A LOT WILL DEPEND ON THE
AMOUNT OF RETURN FLOW THAT CAN DEVELOP AND TIMING OF ANY SHORT WAVE
ENERGY. FOR NOW WILL FOCUS HIGHEST POPS VCNTY OF MTNS WHERE LOW
LEVEL CONVERGENCE WILL BE GREATEST...ALTHOUGH COOLER THAN NORMAL
TEMPS SUGGESTS INSTABILITY WILL BE MAINLY DIURNALLY DRIVEN.

&&

.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 150 AM EDT THURSDAY...

FORECAST AREA CURRENTLY IN BETWEEN WEATHER SYSTEMS...WITH THE SHORT
WAVE OF WEDNESDAY HAVING PASSED OFF TO THE EAST AND ANOTHER STRONGER
UPPER LOW PRESSURE SYSTEM APPROACHING FROM THE WEST FOR FRI INTO THE
WEEKEND. PRIOR TO 14Z...THERE WILL BE POCKETS OF IFR-LIFR
VSBYS/CIGS...MAINLY IN THE USUALLY FAVORED SPOTS FOR SUCH...NAMELY
LWB...BLF...AND BCB. WILL NEED TO WATCH LYH FOR SUCH LATER AS WELL.
CALM WINDS AND MOIST GROUND FROM WIDESPREAD -RA WED WILL PROMOTE
RADIATIONAL FOG DEVELOPMENT OVERNIGHT. ALREADY OBSERVING IFR-LIFR
VSBYS/CIGS AT BLF. AFT 14Z...EXPECT VFR CIGS/VSBYS THROUGHOUT
REMAINDER OF TAF VALID PERIOD WITH ONLY A FEW FAIR WEATHER CU
EXPECTED AOA 050. WINDS CHAOTIC AND LIGHT THROUGHOUT TAF VALID
PERIOD...FAVORING A LIGHT WNW DIRECTION THROUGH MID-DAY...THEN
MOSTLY VRB03-04KT FOR THE REMAINDER OF TAF VALID PERIOD.

AS OF 650 PM EDT WEDNESDAY...

FEW SHOWERS REMAIN ACROSS THE NE BUT EXPECT FURTHER DISSIPATION WITH
LOSS OF HEATING SO THINKING MAY BE ABLE TO RUN WITHOUT ANY PRECIP
MENTION TO INIT AT MOST TAF SITES OUTSIDE OF KLYH THIS EVENING.
WAVE EXITS BY MIDNIGHT WITH DECENT SUBSIDENCE SPILLING EAST
ALLOWING FOR CLEARING SKIES AND SLOWLY FALLING DEWPOINTS. HOWEVER
APPEARS ENOUGH LOW LEVEL MOISTURE MAY LINGER LONG ENOUGH TO CAUSE
FOG FORMATION IN THE VALLEYS AND IN SPOTS NEAR WHERE EARLIER RAIN
OCCURRED ESPCLY KDAN. LOW CIGS MAY ALSO BANK UP AROUND KBLF
OVERNIGHT GIVEN WEAK NW FLOW WITH MVFR/IFR FOG LIKELY. OTRW
THINKING LIFR IN FOG/STRATUS AT KLWB AND MAINLY MVFR KBCB/KDAN AND
PERHAPS KLYH.

ANY FOG AND/OR LOW CLOUDS SHOULD HAVE ERODED BY MID MORNING
THURSDAY WITH HIGH PRESSURE PROVIDING FOR VFR UNDER FEW/SCTD CU
INTO THE AFTERNOON UNDER LIGHT WINDS.

ASIDE FROM SOME LATE NIGHT FOG AT LWB/BCB ANTICIPATE THE NEXT
THREAT FOR SUB VFR TO COME WITH A FRONT FRIDAY INTO SATURDAY. THE
FRONT SLOWS AND LINGERS ACROSS THE CAROLINAS THROUGH THE WEEKEND
SUCH THAT THE THREAT OF SHOWERS MAY OCCUR ACROSS SOUTHERN
SECTIONS...WITH SOME MVFR POSSIBLE. THE FRONT WILL BE MOVING SLOWLY
EAST BY MONDAY AS HIGH PRESSURE WORKS IN FROM THE OHIO VALLEY.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...JH/WP
NEAR TERM...JH/WP
SHORT TERM...PM
LONG TERM...PM
AVIATION...RAB/JH/WP










AREA FORECAST DISCUSSION

NWS GREEN BAY WI

 226 PM CDT THU AUG 16 2012

.SHORT TERM...TONIGHT AND FRIDAY.

LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW TODAYS COLD
FRONT NOW MOVING ACROSS LAKE MICHIGAN EARLY THIS
AFTERNOON...ATTACHED TO A SURFACE LOW OVER ONTARIO.  GUSTY NORTHWEST
WINDS BEHIND THE FRONT ARE BRINGING IN A COOLER AIRMASS...AS WELL AS
A STRATO-CU DECK OVER CENTRAL AND NORTH-CENTRAL WISCONSIN.  BOTH DLH
AND MQT RADARS ARE PICKING UP ON WEAK RETURNS IN THIS STRATO-CU AREA
AND EAGLE RIVER REPORTED A LIGHT SHOWER OVER THE PAST HOUR.  WILL
KEEP A SHOWER MENTION FOR NORTH-CENTRAL WISCONSIN FOR THE REST OF
THE AFTERNOON.  AS THE COLD AND MOIST AIR CONTINUES TO FLOW OVER THE
REGION...SHOWER CHANCES AND CLOUD COVER ARE THE MAIN FORECAST
CONCERNS.

TONIGHT...TODAYS COLD FRONT WILL MOVE EAST OVER THE EASTERN GREAT
LAKES WHILE THE BADGER STATE WILL BE BETWEEN THIS FRONT AND HIGH
PRESSURE OVER THE GREAT PLAINS.  BREEZY NORTHWEST WINDS WILL
CONTINUE TO PUSH A WIDESPREAD STRATO-CU DECK ACROSS THE REGION THIS
EVENING.  IN ADDITION...DELTA T/S WILL BE INCREASING TO 15C OVER
WESTERN LAKE SUPERIOR WHICH WILL ADD A LAKE EFFECT COMPONENT TO THE
CLOUD COVER OVER NORTH-CENTRAL WISCONSIN.  AS A RESULT...KEPT A
CHANCE OF SHOWERS ACROSS THE NORTH THROUGH 12Z.  DRIER LOW LEVEL AIR
FINALLY ARRIVES AFTER MIDNIGHT WHICH WILL ERODE THE CLOUD COVER
INCLUDING THE LAKE EFFECT BANDS.  BUT LAKE EFFECT BANDS SHOULD TAKE
LONGER TO ERODE...SO KEPT MOSTLY CLOUDY CONDITIONS IN THE FORECAST
THROUGH THE NIGHT OVER NORTH-CENTRAL WISCONSIN...WHILE GOING MOSTLY
CLEAR NEARLY EVERYWHERE ELSE.  BL WINDS LOOK BEEFY ENOUGH TO PREVENT
DECOUPLING...SO WENT WITH LOWS IN THE MID 40S NORTH TO LOWER 50S
NEAR LAKE MICHIGAN.

FRIDAY...CANADIAN HIGH PRESSURE WILL BE BUILDING EAST ACROSS THE
STATE OF WISCONSIN THROUGH THE DAY.  PLENTY OF DRY AIR PRESENT ON
PROGGED SOUNDINGS...BUT FLOW REMAINS OUT OF THE NORTHWEST OFF OF
LAKE SUPERIOR AND THINK THIS WILL INCREASE LOW LEVEL MOISTURE MORE
THAN THE MODELS ARE SHOWING.  SO LIKE THE IDEA OF THE PREVIOUS SHIFT
WHICH PORTRAY DIURNAL CU BUILD-UP BY LATE IN THE MORNING.  BUT ONCE
MIXING IS ABLE TO TAP INTO THE DRIER AIR ALOFT...SHOULD SEE THE CU
DISSIPATE FAIRLY QUICKLY IN THE AFTERNOON.  REMAINING COOL AND
TURNING CONSIDERABLY LESS HUMID WITH HIGHS IN THE MID 60S NORTH TO
LOW 70S SOUTH.

.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY.

NUMEROUS PERIODS OF SLIGHT CHC POPS IN THE EXTENDED DUE TO
CONTINUED MODEL DISCREPANCIES ON TIMING AND COVERAGE OF SHOWER
ACTIVITY ACROSS WISCONSIN.


...FRIDAY NIGHT THROUGH SUNDAY...
LARGE SCALE UPPER LEVEL TROUGH STALLS OVER THE EASTERN CONUS FOR
THE BEGINNING PART OF THE EXTENDED WITH SHORTWAVE ENERGY SWINGING
THROUGH THE MEAN FLOW INTO WI. MODELS CONTINUE TO HAVE TROUBLE
HANDLING THESE PIECES OF ENERGY. AGREEMENT THAT FRIDAY NIGHT WILL
REMAIN DRY WITH MANY MODELS TRENDING DOWN IN THE AMOUNT OF CLOUDS
THAT WILL FILTER INTO NORTHERN WISCONSIN OVERNIGHT. STILL THINK
THERE WILL BE ENOUGH CLOUDINESS TO KEEP OVERNIGHT TEMPS ABOVE
FROST CRITERIA...BUT WILL CONTINUE TO MONITOR SITUATION IN CASE
DECREASING CLOUD TREND CONTINUES.

A WEAK SFC FRONT WILL SLIP SOUTH THROUGH WI SATURDAY AS A 500MB
SHORTWAVE MOVES INTO THE GREAT LAKES REGION. THERE IS STILL
DISAGREEMENT BETWEEN MODELS ON HOW QUICKLY THE 500MB SHORTWAVE
DIGS INTO IL...WITH THE ECMWF BEING THE SLOWEST AND THE THE GFS
BEING THE FASTEST. GFS IS THE OUTLIER AND HAS WIDESPREAD PRECIP
BREAKING OUT BY 18Z SAT. HOWEVER... IT IS THE OUTLIER AND MODEL
CONSENSUS KEEPS PRECIP CONFINED TO NORTHERN WISCONSIN. THEREFORE
KEPT SOUTHERN PORTIONS OF THE CWA DRY WITH CHC IN NORTHERN WI.

MODELS DISAGREE FURTHER ON PRECIP CHANCES SATURDAY NIGHT. SOME
MODELS CONTINUE SHOWERS THROUGH 09Z SUN IN CENTRAL WI AND THE FOX
VALLEY...WHILE OTHERS SHUT THE PRECIP OFF AFTER SUNSET. GIVEN THE
DIURNALLY DRIVEN NATURE OF THE PRECIP AND THAT THERE IS VERY
LITTLE UPPER LEVEL DYNAMICS/FORCING TO KEEP THE SHOWERS GOING
THROUGH THE NIGHT...WILL DRY THINGS OUT BY 06Z SUNDAY.

SHOWERS SHOULD THEN DEVELOP AGAIN NEAR THE SLOW MOVING SFC FRONT
SUNDAY AFTERNOON. MODELS ARE TRENDING TOWARDS EASTERN WI SEEING
THE BEST CHCS OF SHOWERS SO INCREASED POPS TO CHC OVER THE EAST.
OTHERWISE...CONTINUED WITH THE WIDESPREAD SLIGHT CHC POPS.


...MONDAY NIGHT THROUGH WEDNESDAY...

SHOULD BE DRY MONDAY NIGHT INTO TUESDAY DUE TO A WEAK UPPER RIDGE
PASSING THROUGH WISCONSIN. A MORE SIGNIFICANT SHORT WAVE WILL
RESULT IN AT LEAST A SLIGHT CHANCE FOR SHOWERS AND THUNDERSTORMS
AROUND THE MIDDLE OF THE WEEK.

EXPECT BELOW NORMAL TEMPERATURES THROUGH MONDAY WITH A WARMER
WEATHER TUESDAY AND WEDNESDAY IN SOUTHERLY FLOW AHEAD OF AN
APPROACHING SURFACE SYSTEM OVER THE PLAINS.
&&

.AVIATION...FOR 12Z TAF ISSUANCE. LARGE AREA OF MVFR AND LOW-END
VFR CIGS WL DROP SE ACRS THE AREA IN THE WAKE OF THE COLD FRONT.
MVFR CIGS MAY LINGER THROUGHOUT TNGT IN THE N DUE TO COLDER AIR
FLOWING ACRS LAKE SUPERIOR.
&&

.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$
MPC/WOLF







AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 705 PM MDT FRI AUG 17 2012

.DISCUSSION...
SURFACE COLD FRONT APPEARED TO BE ROUGHLY FROM EAST OF KCDR TO
NEAR KEAN AT 00Z.  HOWEVER...WINDS FURTHER SOUTH HAVE TURNED TO
MORE NORTHEAST AS WELL IN MUCH OF SOUTHEAST WYOMING.  THE FRONT
SHOULD MOVE THROUGH THE ENTIRE CWA BY 09Z.  ATMOSPHERE IS DRY
AND RELATIVELY STABLE EARLY THIS AFTERNOON OVER THE CWA.  SOME
WEAK RETURNS WERE OBSERVED AROUND 2330Z ON THE COLORADO BORDER
SOUTH OF LARAMIE.  ADDITIONAL DEVELOPMENT SEEMS UNLIKELY THE REST
OF TONIGHT...SO HAVE TAKEN OUT THE MENTION OF SHOWERS AND STORMS
IN A RECENT UPDATE.  OTHERWISE...ONLY MINOR FIRST PERIOD CHANGES
WERE MADE TO THE FORECAST.

&&

.PREVIOUS DISCUSSION.../ISSUED AT 602 PM MDT FRI AUG 17 2012/...

.AVIATION...00Z TAF ISSUANCE...
COLD FRONT TO MOVE ACROSS SE WY AND THE WRN NEB PANHANDLE THIS
EVENING. WINDS WILL GENERALLY BE LIGHT ALONG AND BEHIND THE
FRONT. HIGH PRESSURE TO SETTLE IN ACROSS THE AREA LATE TONIGHT
AND SATURDAY. SOME BREEZY CONDITIONS IN THE AFTERNOON ACROSS
MUCH OF THE FORECAST AREA WITH WINDS GUSTING UP TO 25 MPH BUT THEN
WINDS TO BECOME LIGHT AND VARIABLE SATURDAY NIGHT. A FEW STRAY
SHOWERS POSSIBLE THIS EVENING NEAR THE CO/WY BORDER...OTHERWISE
DRY WITH VFR THROUGH SATURDAY NIGHT.

&&

.PREV DISCUSSION... /ISSUED 249 PM MDT FRI AUG 17 2012/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WATER VAPOR IMAGERY SHOWS FAST NORTHWEST FLOW ALOFT OVER THE WY/MT
WITH A STRONG SHORTWAVE DIVING SOUTHWARD OVER SASKATCHEWAN. CUMULUS
HAVE DEVELOPED OVER THE LARAMIE RANGE BUT FAILED TO MOVE EASTWARD
OVER THE PLAINS. THE MODELS ARE IN AGREEMENT IN SHOWING THE
SHORTWAVE DIVING SSE OVER THE NORTHERN PLAINS THROUGH TONIGHT.
ALTHOUGH THERE IS LIMITED LOW AND MIDLEVEL MOISTURE TO WORK
WITH...THE QG LIFT AHEAD OF THE SHORTWAVE COULD ENHANCE CONVECTIVE
CHANCES LATE THIS AFTERNOON AND EVENING. CURRENT LAPS ANALYSIS SHOWS
WEAK SFC INSTABILITY OVER THE PLAINS (WITH A FEW HUNDRED J/KG OF
CAPE).  BOTH THE GFS AND HRRR MODELS GENERATE ISOLATED STORMS OVER
THE SOUTHEASTERN PART OF THE CWA BETWEEN 00Z AND 06Z. KEPT SLIGHT
CHANCE POPS FOR MAINLY AREAS ALONG INTERSTATE 80 TO THE EAST OF THE
LARAMIE RANGE THROUGH EARLY TONIGHT. A 1018MB SFC HIGH BEHIND THE
SHORTWAVE WILL DRIVE A COLD FRONT THROUGH THE AREA LATE TONIGHT.
BREEZY CONDITIONS WILL DEVELOP SAT MORNING AFTER THE FROPA...HOWEVER
PRESSURE RISES/SOUNDINGS DO NOT SUGGEST THAT THE WINDS WILL BE
PARTICULARLY STRONG.

RATHER QUIET THROUGH THE REMAINDER OF THE SHORT TERM WITH VERY DRY
NORTHWESTERLY FLOW ALOFT. HIGHS ON SAT WILL BE AROUND 5 DEGREES
COOLER IN THE POST FRONTAL AIRMASS. THE BREEZY NORTHERLY WINDS
WILL SUBSIDE ON SAT NIGHT AS THE SFC HIGH PRESSURE CENTER SETTLES
OVER THE CWA. WENT A FEW DEGREES COOLER THAN MOS FOR LOWS ON SAT
NIGHT...WITH VALUES MAINLY IN THE MID-TO-UPPER 40S OVER THE
PLAINS...WITH GOOD RADIATION AL COOLING POTENTIAL. 700MB TEMPS RISE
ON SUN TO 9C (FROM 7C ON SAT) FOR A FEW DEGREES OF WARMING...BUT
LITTLE OTHER CHANGE IN THE SENSIBLE WEATHER. A SHORTWAVE WILL
ROUND THE TOP OF THE INTERMOUNTAIN WEST RIDGE ON SUN
NIGHT...APPROACHING THE CWA BY MON.

LONG TERM...MONDAY THROUGH FRIDAY
LONG TERM GENERALLY DOMINATED BY A RIDGE OF HIGH PRESSURE WITH THE
RIDGE AXIS WEST OF THE CWA EARLY. WE GET A SHORTWAVE THAT MOVES DOWN
THROUGH THE NORTHWEST FLOW MONDAY...EXITING EAST BY MONDAY
AFTERNOON. GENERALLY DRY CONDITIONS EXPECTED WITH THE EXCEPTION
POSSIBLY BEING THE HIGHER TERRAIN OF THE SNOWY...SIERRA MADRE AND
NORTHERN LARAMIE RANGES MONDAY AFTERNOON.

RIDGE AXIS THEN BUILDS OVER THE CWA TUESDAY WITH THE AXIS SHIFTING
EAST BY TUESDAY AFTERNOON. COULD SEE AN INCREASE IN FIRE WEATHER
CONCERNS AS WINDS SHIFT SOUTHWEST AND BEGIN TO INCREASE. GFS
SHOWING 20 TO 25KTS OF WIND AT 700MB AS ANOTHER SHORTWAVE TRACKS
INTO IDAHO AND NORTHERN UTAH. THIS SHORTWAVE TRACKS NORTHEAST
ACROSS WESTERN WYOMING TUESDAY NIGHT INTO WEDNESDAY...DRAGGING A
COLD FRONT THROUGH AT LEAST OUR WESTERN ZONES WEDNESDAY EVENING.
MAINTAINED...AND SLIGHTLY INCREASED POP COVERAGE FOR THIS AREA
WEDNESDAY NIGHT. WEDNESDAY MOST LIKELY OUR WARMEST DAY NEXT WEEK
WITH HIGHS CLIMBING BACK INTO THE 90S WITH THESE GUSTY WINDS. DRIER
CONDITIONS RETURNING FOR THE END OF THE WEEK CWA WIDE.

AVIATION...18Z TAFS
VFR CONDITIONS EXPECTED NEXT 24 HOURS AT MOST AIRPORTS ACROSS
SOUTHEAST WYOMING AND NEBRASKA PANHANDLE. CHEYENNE COULD SEE SOME
ISOLATED THUNDERSTORMS THIS AFTERNOON...BUT CONFIDENCE NOT HIGH
ENOUGH TO NAIL DOWN TIMING. WENT WITH VCTS WORDING IN TAF UNTIL THE
01-02Z TIME FRAME. ELSEWHERE...MAINLY CLEAR SKIES AND NO IMPACTS TO
AVIATION INTERESTS.

FIRE WEATHER...
FIRE WEATHER CONCERNS WILL BE MINIMAL THROUGH THE WEEKEND. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT BRINGING BREEZY NORTHERLY
WINDS AND COOLER THAN AVERAGE TEMPERATURES ON SATURDAY. MINIMUM
AFTERNOON RELATIVE HUMIDITY VALUES WILL BE IN THE 15 TO 20 PERCENT
RANGE. THE AIRMASS WILL BEGIN TO WARM ON SUNDAY WITH AFTERNOON
HUMIDITIES DROPPING BELOW 15 PERCENT TO THE WEST OF THE LARAMIE
RANGE. HOWEVER...WINDS WILL BE LIGHT WITH THE SURFACE HIGH PRESSURE
CENTER NEAR SOUTHEAST WYOMING. PRECIPITATION CHANCES WILL BE LOW
THROUGH EARLY NEXT WEEK WITH A DRY AIRMASS IN PLACE...HOWEVER SOME
ISOLATED SHOWER AND THUNDERSTORMS WILL BE POSSIBLE STARTING MONDAY
OVER THE MOUNTAINS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/FIRE WEATHER...FINCH
LONG TERM...CLAYCOMB
AVIATION...LIEBL












AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 602 PM MDT FRI AUG 17 2012

.AVIATION...00Z TAF ISSUANCE...
COLD FRONT TO MOVE ACROSS SE WY AND THE WRN NEB PANHANDLE THIS
EVENING. WINDS WILL GENERALLY BE LIGHT ALONG AND BEHIND THE
FRONT. HIGH PRESSURE TO SETTLE IN ACROSS THE AREA LATE TONIGHT
AND SATURDAY. SOME BREEZY CONDITIONS IN THE AFTERNOON ACROSS
MUCH OF THE FORECAST AREA WITH WINDS GUSTING UP TO 25 MPH BUT THEN
WINDS TO BECOME LIGHT AND VARIABLE SATURDAY NIGHT. A FEW STRAY
SHOWERS POSSIBLE THIS EVENING NEAR THE CO/WY BORDER...OTHERWISE
DRY WITH VFR THROUGH SATURDAY NIGHT.

&&

.PREV DISCUSSION... /ISSUED 249 PM MDT FRI AUG 17 2012/

SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...

WATER VAPOR IMAGERY SHOWS FAST NORTHWEST FLOW ALOFT OVER THE WY/MT
WITH A STRONG SHORTWAVE DIVING SOUTHWARD OVER SASKATCHEWAN.
CUMULUS HAVE DEVELOPED OVER THE LARAMIE RANGE BUT FAILED TO MOVE
EASTWARD OVER THE PLAINS. THE MODELS ARE IN AGREEMENT IN SHOWING
THE SHORTWAVE DIVING SSE OVER THE NORTHERN PLAINS THROUGH TONIGHT.
ALTHOUGH THERE IS LIMITED LOW AND MIDLEVEL MOISTURE TO WORK
WITH...THE QG LIFT AHEAD OF THE SHORTWAVE COULD ENHANCE
CONVECTIVE CHANCES LATE THIS AFTERNOON AND EVENING. CURRENT LAPS
ANALYSIS SHOWS WEAK SFC INSTABILITY OVER THE PLAINS (WITH A FEW
HUNDRED J/KG OF CAPE).  BOTH THE GFS AND HRRR MODELS GENERATE
ISOLATED STORMS OVER THE SOUTHEASTERN PART OF THE CWA BETWEEN 00Z
AND 06Z. KEPT SLIGHT CHANCE POPS FOR MAINLY AREAS ALONG INTERSTATE
80 TO THE EAST OF THE LARAMIE RANGE THROUGH EARLY TONIGHT. A
1018MB SFC HIGH BEHIND THE SHORTWAVE WILL DRIVE A COLD FRONT
THROUGH THE AREA LATE TONIGHT. BREEZY CONDITIONS WILL DEVELOP SAT
MORNING AFTER THE FROPA...HOWEVER PRESSURE RISES/SOUNDINGS DO NOT
SUGGEST THAT THE WINDS WILL BE PARTICULARLY STRONG.

RATHER QUIET THROUGH THE REMAINDER OF THE SHORT TERM WITH VERY DRY
NORTHWESTERLY FLOW ALOFT. HIGHS ON SAT WILL BE AROUND 5 DEGREES
COOLER IN THE POST FRONTAL AIRMASS. THE BREEZY NORTHERLY WINDS
WILL SUBSIDE ON SAT NIGHT AS THE SFC HIGH PRESSURE CENTER SETTLES
OVER THE CWA. WENT A FEW DEGREES COOLER THAN MOS FOR LOWS ON SAT
NIGHT...WITH VALUES MAINLY IN THE MID-TO-UPPER 40S OVER THE
PLAINS...WITH GOOD RADIATION AL COOLING POTENTIAL. 700MB TEMPS RISE
ON SUN TO 9C (FROM 7C ON SAT) FOR A FEW DEGREES OF WARMING...BUT
LITTLE OTHER CHANGE IN THE SENSIBLE WEATHER. A SHORTWAVE WILL
ROUND THE TOP OF THE INTERMOUNTAIN WEST RIDGE ON SUN
NIGHT...APPROACHING THE CWA BY MON.

LONG TERM...MONDAY THROUGH FRIDAY

LONG TERM GENERALLY DOMINATED BY A RIDGE OF HIGH PRESSURE WITH
THE RIDGE AXIS WEST OF THE CWA EARLY. WE GET A SHORTWAVE THAT
MOVES DOWN THROUGH THE NORTHWEST FLOW MONDAY...EXITING EAST BY
MONDAY AFTERNOON. GENERALLY DRY CONDITIONS EXPECTED WITH THE
EXCEPTION POSSIBLY BEING THE HIGHER TERRAIN OF THE SNOWY...SIERRA
MADRE AND NORTHERN LARAMIE RANGES MONDAY AFTERNOON.

RIDGE AXIS THEN BUILDS OVER THE CWA TUESDAY WITH THE AXIS SHIFTING
EAST BY TUESDAY AFTERNOON. COULD SEE AN INCREASE IN FIRE WEATHER
CONCERNS AS WINDS SHIFT SOUTHWEST AND BEGIN TO INCREASE. GFS
SHOWING 20 TO 25KTS OF WIND AT 700MB AS ANOTHER SHORTWAVE TRACKS
INTO IDAHO AND NORTHERN UTAH. THIS SHORTWAVE TRACKS NORTHEAST
ACROSS WESTERN WYOMING TUESDAY NIGHT INTO WEDNESDAY...DRAGGING A
COLD FRONT THROUGH AT LEAST OUR WESTERN ZONES WEDNESDAY EVENING.
MAINTAINED...AND SLIGHTLY INCREASED POP COVERAGE FOR THIS AREA
WEDNESDAY NIGHT. WEDNESDAY MOST LIKELY OUR WARMEST DAY NEXT WEEK
WITH HIGHS CLIMBING BACK INTO THE 90S WITH THESE GUSTY WINDS. DRIER
CONDITIONS RETURNING FOR THE END OF THE WEEK CWA WIDE.

AVIATION...18Z TAFS

VFR CONDITIONS EXPECTED NEXT 24 HOURS AT MOST AIRPORTS ACROSS
SOUTHEAST WYOMING AND NEBRASKA PANHANDLE. CHEYENNE COULD SEE SOME
ISOLATED THUNDERSTORMS THIS AFTERNOON...BUT CONFIDENCE NOT HIGH
ENOUGH TO NAIL DOWN TIMING. WENT WITH VCTS WORDING IN TAF UNTIL THE
01-02Z TIME FRAME. ELSEWHERE...MAINLY CLEAR SKIES AND NO IMPACTS TO
AVIATION INTERESTS.

FIRE WEATHER...

FIRE WEATHER CONCERNS WILL BE MINIMAL THROUGH THE WEEKEND. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT BRINGING BREEZY NORTHERLY
WINDS AND COOLER THAN AVERAGE TEMPERATURES ON SATURDAY. MINIMUM
AFTERNOON RELATIVE HUMIDITY VALUES WILL BE IN THE 15 TO 20 PERCENT
RANGE. THE AIRMASS WILL BEGIN TO WARM ON SUNDAY WITH AFTERNOON
HUMIDITIES DROPPING BELOW 15 PERCENT TO THE WEST OF THE LARAMIE
RANGE. HOWEVER...WINDS WILL BE LIGHT WITH THE SURFACE HIGH
PRESSURE CENTER NEAR SOUTHEAST WYOMING. PRECIPITATION CHANCES WILL
BE LOW THROUGH EARLY NEXT WEEK WITH A DRY AIRMASS IN
PLACE...HOWEVER SOME ISOLATED SHOWER AND THUNDERSTORMS WILL BE
POSSIBLE STARTING MONDAY OVER THE MOUNTAINS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/FIRE WEATHER...FINCH
LONG TERM...CLAYCOMB
AVIATION...LIEBL










AREA FORECAST DISCUSSION

NWS TUCSON AZ

 925 PM MST FRI AUG 17 2012

.SYNOPSIS...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS INTO NEXT WEEK. BELOW NORMAL DAYTIME TEMPERATURES
WILL OCCUR THIS WEEKEND FOLLOWED BY A SLIGHT WARMING TREND NEXT WEEK.

&&

.DISCUSSION...MOSTLY CLOUDY SKIES ACROSS SE AZ AT THIS TIME.
SCATTERED SHOWERS/TSTMS HAVE DEVELOPED DURING THE PAST 30 MINUTES OR
SO WELL TO THE NORTH OF THE WHITE MOUNTAINS. RUC HRRR DEPICTS
SHOWERS/TSTMS TO MOVE INTO NERN SECTIONS DURING THE NEXT 2-3 HOURS.
OTHER LIGHT SHOWERS ARE PROGGED TO DEVELOP NEAR THE INTERNATIONAL
BORDER ADJACENT PIMA COUNTY LATER TONIGHT. GIVEN THE MOIST
AIRMASS...WILL MAINTAIN A SLIGHT CHANCE OF SHOWERS/TSTMS MOST
SECTIONS THE REST OF TONIGHT. SCATTERED SHOWERS/TSTMS ON TAP SAT AS
DIFFLUENT FLOW ALOFT PREVAILS OVER THE AREA.

&&

.PREV DISCUSSION...THE NAM AND GFS DIFFER SLIGHTLY FOR SATURDAY WITH
THE NAM DRYING OUT FASTER THAN THE GFS. SINCE THIS MUCH MOISTURE
CANNOT LEAVE QUICKLY...KEEP LIKELY POPS AT MANY LOCATIONS THROUGH
SATURDAY...THEN TAPER ACTIVITY DOWN SATURDAY NIGHT AND SUNDAY.

NEXT WEEK HAS A WARMING TREND AS THE AIR MASS DRIES OUT. HOWEVER
SCATTER SHOWERS AND THUNDERSTORMS ARE EXPECTED EVERYDAY NEXT WEEK.
THE MODELS KEEP A HEALTHY MONSOON PATTERN OVER THE SOUTHWEST THROUGH
THE FORECAST PERIOD.

&&

.AVIATION...THE NEARLY SATURATED SFC AT KOLS COMBINED WITH THE
RESIDUAL LOW LVL MOISTURE AND LIGHT WINDS MAY CONTRIBUTE TO SOME BR
DEVELOPMENT NEAR THE TERMINAL. WILL HAVE TO REEVALUATE WITH 06Z
ISSUANCE. ALSO...TS DEVELOPMENT EXPECTED ACROSS SRN AZ THURS
AFTN...SPREADING GENERALLY NEWD FROM THE GULF OF CALI.
THEREFORE...HAVE ADDED VCTS MENTION TO BOTH KTUS AND KOLS AFTER
18/17Z RESPECTIVELY. AS FOR NEAR KDUG...TS DEVELOPMENT IS EXPECTED
TO LAG BY A FEW HOURS. OTHERWISE...GENERALLY LIGHT WINDS EXPECTED
THRU THE PERIOD OR 06Z SUN. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.

&&

.FIRE WEATHER...SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN BE
POSSIBLE SATURDAY...WITH A SLIGHT DRYING TREND AFTERWARD.
STILL...WITH FRIDAY/S WETTING RAINFALL GOOD RH RECOVERIES CAN BE
EXPECTED TO CONTINUE. THIS SHOULD CONTRIBUTE TO TEMPERATURES
REMAINING BELOW SEASONABLE NORMALS.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$









AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 241 AM CDT SAT AUG 18 2012

...UPDATED FOR SHORT TERM DISCUSSION...

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 230 AM CDT SAT AUG 18 2012

A LARGE UPPER-LEVEL TROUGH WAS CENTERED OVER THE GREAT LAKES REGION
EARLY THIS MORNING. A SHORTWAVE TROUGH HAS ALREADY ROTATED AROUND
THIS FEATURE AND PUSHED A COLD FRONT INTO THE SOUTHERN PLAINS. THE
WESTERN END OF THIS FRONT PUSHED BACK NORTHWARD INTO NORTHEAST NEW MEXICO
FRIDAY AFTERNOON WHERE SURFACE BASED CONVECTION DEVELOPED. SURFACE
LOW PRESSURE WAS DEVELOPING IN EASTERN COLORADO AS OF 3 AM IN RESPONSE
TO THE NEXT ROBUST SHORTWAVE TROUGH THAT WAS DIVING SOUTHEASTWARD
INTO THE NORTHERN PLAINS ON THE BACK SIDE OF THE GREAT LAKES
LONGWAVE TROUGH.

A LOW LEVEL JET HAD DEVELOPED EARLY THIS MORNING IN RESPONSE TO THE
APPROACHING SHORTWAVE TROUGH. STRONG THETA-E ADVECTION WAS LOCATED
ACROSS FAR WESTERN KANSAS AND WAS PROGRESSING NORTHEASTWARD. NAM
SOUNDINGS VALID FOR 12Z SHOW 1800-2400 J/KG OF ELEVATED CAPE AS FAR
EAST AS CIMARRON AND SCOTT CITY. THUNDERSTORMS WERE ALREADY DEVELOPING
IN THE WARM ADVECTION REGIME ALONG THE EDGE OF THE MID LEVEL CAPPING
INVERSION AS OF 230 AM. ADDITIONAL STORMS WILL DEVELOP AND
PROPAGATE SOUTHEASTWARD WITH THE MID-LEVEL FLOW. THE HRRR AND NAM
INDICATE THAT THE BEST CHANCE OF THUNDERSTORMS WILL BE ALONG AN
AXIS FROM SCOTT CITY TO NESS CITY TO DODGE CITY TO COLDWATER.
PRECIPITATION CHANCES WERE RAISED TO 60-70% IN THIS CORRIDOR.
GIVEN THE ELEVATED SHEAR AND MODERATE ELEVATED CAPE, SEVERE STORMS
ARE POSSIBLE WITH HAIL AS LARGE AS HALF DOLLARS.

THE CONVECTIVE CLUSTER WILL BE SLOW TO EXIT SOUTHERN KANSAS THIS
AFTERNOON SO THAT SOUTHEASTERLY OUTFLOW IN THE WAKE OF THE STORMS
WILL TEND TO KEEP COOL AIR IN PLACE EVEN IF SOME CLEARING OCCURS.
HOWEVER, IF THE MORNING STORM CLUSTER MOVES THROUGH FAST ENOUGH,
THEN DESTABILIZATION COULD LEAD TO RENEWED THUNDERSTORMS BY
MID-AFTERNOON SINCE THE COLD FRONT WILL NOT HAVE PASSED YET. THESE
STORMS COULD BE SURFACE BASED AND COULD ALSO BE SEVERE. HIGH
TEMPERATURES WERE LOWERED SEVERAL DEGREES, ESPECIALLY FROM DODGE
CITY SOUTH AND EAST AND ACTUAL HIGHS WILL PROBABLY OCCUR TOWARD 6-7
PM.

THE COLD FRONT ASSOCIATED WITH THIS UPPER-LEVEL SYSTEM WILL PASS
THROUGH LATE THIS EVENING. CLEARING WILL OCCUR LATE TONIGHT IN
THE WAKE OF THIS SYSTEM WITH SUBSIDING WINDS TOWARD SUNRISE. THE
COOLEST TEMPERATURES OF THE SEASON ARE POSSIBLE, WITH SOME UPPER
40S NOT OUT OF THE QUESTION NEAR SCOTT CITY. SLIGHTLY WARMER MINIMUM
TEMPERATURES IN THE LOWER TO MID 50S ARE EXPECTED AT GARDEN CITY AND
DODGE CITY.


.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 228 AM CDT SAT AUG 18 2012

AN AREA OF HIGH PRESSURE AT THE SURFACE WILL SETTLE INTO CENTRAL
PLAINS ON SUNDAY. SKIES WILL CLEAR AND BASED ON 850MB TEMPERATURES
TRENDS BETWEEN 18Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL
APPEARS ON TRACK WITH HIGHS CLIMBING INTO THE LOW TO MID 80S.

A CLEAR AND COOL NIGHT CAN BE EXPECTED SUNDAY NIGHT AS THIS SURFACE
HIGH SLOWLY CROSSES WESTERN AND CENTRAL KANSAS. BASED ON WHERE THE
LIGHTEST WINDS WILL BE BETWEEN 09Z AND 12Z SUNDAY  AM LEANING
TOWARDS UNDERCUTTING THE COOLEST GUIDANCE WHILE STAYED CLOSE TO THE
MAV/MET ELSEWHERE.

ON MONDAY THE NEXT UPPER LEVEL DISTURBANCE WILL BEGIN TO CROSS THE
CENTRAL ROCKIES. THE GFS, NAM, AND ECMWF REMAIN IN DECENT AGREEMENT
WITH THIS NEXT SYSTEM EXITING THE ROCKIES AND CROSSING INTO THE
CENTRAL PLAINS LATE MONDAY NIGHT AND TUESDAY. AS THIS SYSTEM
CROSSING INTO THE PLAINS...SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP WITH THE BETTER CHANCES FOR WIDESPREAD
PRECIPITATION BEING LATE MONDAY NIGHT/EARLY TUESDAY BASED ON THE
UPPER LEVEL JET DYNAMICS, 850-700MB MOISTURE AND IMPROVING
FRONTOGENESIS.

ONCE THIS SYSTEM EXITS THE CENTRAL PLAINS AND MOVES TOWARDS THE
LOWER MISSISSIPPI VALLEY THE MID LEVEL FLOW WILL BACK AND BECOME
MORE PERPENDICULAR TO THE ROCKIES. THIS ENHANCED DOWNSLOPE FLOW
SUGGESTS A WARMING TREND MID WEEK AS A TROUGH OF LOW PRESSURE AT THE
SURFACE BEGINS TO DEVELOP ALONG THE LEE OF THE ROCKIES.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1241 AM CDT SAT AUG 18 2012

A CLUSTER OF THUNDERSTORMS IS EXPECTED TO DEVELOP AHEAD OF A
STRONG SHORTWAVE TROUGH TOWARD 12Z OVER NORTHWEST KANSAS AS A LOW LEVEL
JET DEVELOPS AND TRANSPORTS RICH MOISTURE INTO THE CENTRAL HIGH PLAINS.
THESE STORMS ARE EXPECTED TO MOVE SOUTHEAST AND POSSIBLY AFFECT
GCK/DDC/HYS BETWEEN 12 AND 18Z, WITH DDC BEING THE MOST LIKELY
TERMINAL TO BE AFFECTED. AWAY FROM THE THUNDERSTORMS, VFR
CONDITIONS WILL PERSIST. SOME OBSTRUCTION TO VISIBILITIES
IS POSSIBLE WITH ANY AREAS OF HEAVY RAIN. SOME STRONG WIND GUSTS
CANNOT BE RULED OUT BUT ARE NOT THE MAIN THREAT DUE TO THE
ELEVATED NATURE OF THE CONVECTION,


&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  76  52  82  52 /  60  10  10   0
GCK  79  51  82  53 /  60  10  10  10
EHA  83  61  83  56 /  30  20  10  10
LBL  80  58  84  54 /  50  20  10  10
HYS  82  49  82  52 /  60  10  10   0
P28  79  59  84  52 /  60  20  10   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...FINCH










AREA FORECAST DISCUSSION

NWS CARIBOU ME

 418 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WILL STALL ALONG THE MAINE COAST TODAY AND TONIGHT.
LOW PRESSURE WILL APPROACH FROM THE SOUTH LATER SUNDAY AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
A COLD FRONT IS EXPECTED TO BECOME STATIONARY ALONG THE DOWNEAST
COAST TODAY. WITH UPPER LOW NEAR JAMES BAY AND 500MB FLOW PARALLEL
TO THE FRONT THIS SCENARIO LOOKS MOST REASONABLE. AT THE SAME TIME
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE WEST LATER TODAY AND
TONIGHT. FOR POPS HAVE BEEN USING HRRR THEN MERGING IT WITH BLEND
OF THE NAM12...GFS40...SREF AND ECMWF. FOR QPF HAVE USED THE SAME
BLEND BUT WILL EXCHANGE NAM12 FOR NAM80. FOR WIND HAVE BLENDED
NAM12 AND GMOS AND WILL USE ONLY GMOS LATE TONIGHT. FOR
TEMPERATURE AND DEW POINT WILL USE GMOS WITH SOME MINOR
ADJUSTMENTS TO MAXIMUM TEMPERATURE.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MAIN CHALLENGE WILL BE STALLED FRONTAL BOUNDARY ALONG THE COAST ON
SUNDAY AND WEAK LOW PRES WAVE MOVING UP ALONG THE FRONT.

DECIDED TO FOLLOW A BLEND OF THE ECMWF AND CANADIAN GLOBAL THIS
FCST CYCLE SHOWING AN AREA OF RAIN AFFECTING MAINLY THE COAST AND
OVER THE GULF OF MAINE WATERS FOR SUNDAY. THESE 2 NUMERICAL MODELS
WERE CONSISTENT W/THEIR PREVIOUS RUNS OF SHOWING THIS WAVE MOVING
UP ALONG THE FRONT. THE BOUNDARY WILL SERVE AS A CONVERGENCE AXIS
AND W/THE LOW, ENOUGH FORCING WILL BE THERE FOR A PERIOD OF RAIN
IN THE AFOREMENTIONED AREAS. THEREFORE, INCREASED THE RAIN PERCENTAGES
TO 50-60% ACROSS THE COAST AND OVER THE WATERS UP THROUGH 18Z AND
THEN DRY THINGS OUT AS THE FRONT SLIDES FURTHER SOUTH AND
EAST.THIS WILL ALSO HOLD DOWN TEMPERATURES OVER THE DOWNEAST AND
THE COAST(LOW/MID 70S). FURTHER NORTH AND WEST, DRIER CONDITIONS
AND HENCE WARMER TEMPERATURES(MID-UPPER 70S). QPF AMOUNTS WERE
ADJUSTED USING THE ECMWF AND CANADIAN GLOBAL W/AREAL ADJUSTMENTS.
THEREFORE, NOT EXPECTING MORE THAN .10" OF RAINFALL ALONG THE
IMMEDIATE COAST.

HIGH PRES IS SET TO RIDGE IN ACROSS THE CWA FROM THE SW SUNDAY
NIGHT INTO MONDAY. THIS SHOULD ALLOW FOR DRY CONDITIONS AND WARMER
TEMPERATURES. BROAD SWLY FLOW ALOFT WILL ALLOW FOR SOME CUMULUS TO
DEVELOP BY LATE MORNING. REMOVED THE MENTION OF RAIN SHOWERS FOR
MONDAY AND RAISED MAXES FROM THE PREVIOUS FORECAST UP A CATEGORY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BACKED AWAY FROM GMOS THROUGH WEDNESDAY AND BASICALLY STAYED
CLOSER TO THE ECMWF. THE ECMWF HAS BEEN CONSISTENT W/THE SYNOPTIC
PATTERN OF A  BROAD SW FLOW ALOFT W/CLOSED LOWER OVER HUDSON`S BAY.
THIS WILL ALLOW FOR A WAVE OF LOW PRES TO DEVELOP ON THAT STALLED
FRONTAL BOUNDARY JUST OFF THE MAINE COAST TO MOVE UP ALONG THE
FRONT ON TUESDAY. THE GFS APPEARED TO BE TOO STRONG AND AGGRESSIVE
W/THE LOW WHILE THE ECMWF AND CANADIAN GLOBAL KEEP THE LOW FURTHER
S AND E AND BOTH ARE NOT AS STRONG W/THE WAVE AND HAVE A SECOND
FRONT APPROACHING FROM CANADA BY TUESDAY AFTERNOON. DECIDED TO CUT
BACK ON PRECIP CHANCES TUESDAY W/THE LOW OFF THE COAST AND LEAN
W/A 20-30% CHANCE FOR SHOWERS IN THE AFTERNOON DUE TO THE COLD
FRONT MOVING IN FROM THE WEST. BOTH THE CANADIAN GLOBAL AND ECMWF
SUPPORT SOME SHOWER AS UPPER LEVEL SUPPORT IS THERE. TWEAKED
TEMPERATURES FOR TUESDAY TO BRING THEM UP A CATEGORY INTO THE
MID AND UPPER 70S. HIGH PRES AT THE SFC IS SHOWN TO MOVE ACROSS
THE REGION ON WEDNESDAY AND THE FRONT SLIDES TO THE EAST. THIS
WILL ALLOW FOR A DRY AND COMFORTABLE DAY. UPPER FLOW APPEARS TO
SHIFT A BIT TO A MORE WESTERLY COMPONENT ALLOWING FOR A DRIER SETUP.
OVERNIGHT TEMPERATURES MONDAY NIGHT AND AGAIN TUESDAY NIGHT LOOKED
TO NEED ADJUSTMENTS UPWARD USING A NAM12/GMOS BLEND. BROAD SW FLOW
ALOFT SEEMS TO FAVOR A WARM SCENARIO. DAYCREW CAN ASSESS THIS
FURTHER W/NEWER MODEL GUIDANCE.

THE UPPER TROF LOOKS LIKE IT WILL SHARPEN AGAIN BY LATE WEEK W/S
FRONTAL BOUNDARY APPROACHING. THERE IS THE POTENTIAL FOR SHOWERS
AND POSSIBLE TSTMS ON THURSDAY AND AGAIN FRIDAY AND THE FRONT WILL
BE SLOW TO MOVE ACROSS THE REGION. ATTM, STAYED CLOSER TO GMOS
W/30% POPS AND STAYED CLOSER TO THE TEMPERATURES SHOWING NEAR
NORMAL READINGS FOR LATE AUGUST.

&&

.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: EXPECT VFR CONDITIONS TODAY WITH IFR CONDITIONS LATER
TONIGHT MOSTLY DUE TO CEILINGS.

SHORT TERM: POSSIBLE IFR/MVFR FOR THE COAST ON SUNDAY AND THEN
CONDITIONS IMPROVE TO VFR. IT LOOKS LIKE VFR FOR THE NORTHERN
TERMINALS THROUGH MONDAY. THERE DOES APPEAR TO BE SOME POTENTIAL
FOR MVFR AND POSSIBLY IFR CONDITIONS LATER MONDAY NIGHT INTO
TUESDAY MORNING W/A LIGHT ESE FLOW SETTING UP.

&&

.MARINE...
NEAR TERM: FOR WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND
GFS40 AND ADJUSTED BLEND DOWN 20 PERCENT DUE TO EXPECTED BOUNDARY
CONDITIONS. WILL USE NAM/SWAN TO INITIALIZE WAVE GRIDS. WILL
ADJUST WAVE MODEL DOWN 1 FOOT. PRIMARY WAVE GROUP IS WEAK
SOUTHERLY FETCH AROUND PERIPHERY OF HIGH OFF-SHORE. WAVE MODELS ARE
TOO HIGH WITH THIS WAVE GROUP. WNA SPECTRAL CONTINUES TO SHOW
BACKGROUND SOUTHEAST SWELL AT AROUND 1 FOOT. VERY LONG PERIOD
SWELL FROM ATLANTIC TROPICAL SYSTEMS MAY SHOW UP BUT NOT UNTIL
NEXT WEEK. WILL KEEP FOG ACROSS COASTAL WATERS WITH FRONT STALLED
ALONG COAST.


SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE NAM12 AND
GFS40 WAS USED FOR THE WINDS INTO MONDAY WHICH SHOWS SUSTAINED
WINDS AT 10-15 KTS. AN ESE SWELL LOOKS POSSIBLE BY MONDAY AND
COULD CONTINUE THROUGH THE WEEK W/A LONG PERIOD. AS MENTIONED
IN THE NEAR TERM, WANAVE RUNNING TOO HIGH AND THEREFORE STAYED
W/THE CURRENT WAVE HEIGHTS OF 2-3 FT THROUGH THE PERIOD.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/HEWITT









AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 501 AM EDT SAT AUG 18 2012

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM EDT SAT AUG 18 2012

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF DOMINATING
ROUGHLY THE E HALF OF THE CONUS. TROF IS ANCHORED BY A MID/UPPER
LEVEL LOW CENTERED OVER JAMES BAY. A NUMBER OF SHORTWAVES ARE
ROTATING THRU THE TROF THOUGH NONE ARE ESPECIALLY STRONG. MOST
NOTABLE WAVES ARE TRACKING SE THRU MN AND THE DAKOTAS...BUT THE WAVE
OF INTEREST FOR TODAY IS DROPPING THRU NRN ONTARIO. CANADIAN RADARS
HAVE BEEN SHOWING SCT SHRA STREAKING SE ACROSS NE LAKE SUPERIOR WITH
MAIN BAND OF SHRA SINKING S TOWARD THE MN ARROWHEAD AND ISLE ROYALE.

FCST THINKING FOR TODAY HASN`T CHANGED MUCH FROM PREVIOUS SHIFTS.
SHORTWAVE WILL DROP INTO THE UPPER LAKES TODAY WITH ASSOCIATED SFC
COLD FRONT MOVING THRU THE AREA. WITH CYCLONIC FLOW...APPROACHING
SHORTWAVE/COLD POCKET ALOFT...COLD FRONT ARRIVING DURING HEATING
CYCLE AND MLCAPE INCREASING TO BTWN 200 AND 500J/KG...IT STILL LOOKS
LIKE A GOOD SETUP FOR SCT/NMRS SHRA TODAY...ESPECIALLY SINCE SHRA
ARE ALREADY OCCURRING UPSTREAM DURING THE PERIOD OF THE DIURNAL MIN.
TIMING OF COLD FRONT INTO THE SRN FCST AREA DURING THE LATER AFTN
SHOULD FAVOR THAT AREA FOR THE GREATEST SHRA COVERAGE. CAN`T RULE
OUT SOME THUNDER AS WELL...PARTICULARLY SINCE A FEW LIGHTNING
STRIKES WERE DETECTED UPSTREAM IN ONTARIO LAST EVENING. AGAIN...THE
SRN PORTIONS OF THE FCST AREA WILL BE FAVORED. LOW FREEZING/WET BULB
ZERO LEVELS SUPPORT POTENTIAL OF SMALL HAIL WITH ANY STORMS...
ESPECIALLY IF THERE IS ENOUGH HEATING THRU THE MORNING HRS TO HELP
BUILD INSTABILITY A LITTLE HIGHER THAN CURRENTLY PROGGED.

ALTHOUGH WAVES ARE SUBSIDING ON LAKE SUPERIOR AFTER A COUPLE OF
ROUGH DAYS...WAVES ARE STILL HIGH ENOUGH TO RESULT IN A MODERATE
RISK OF RIP CURRENTS ALONG THE BEACHES OF ALGER COUNTY THRU EARLY
AFTERNOON.

SIGNIFICANT COLUMN DRYING OCCURS TONIGHT BEHIND SHORTWAVE...MOST
NOTABLY WITH THE GFS. THIS WILL WORK TO MINIMIZE LAKE EFFECT -SHRA
POTENTIAL AS 850MB TEMPS BECOME MARGINALLY LOW ENOUGH OVER THE ERN
LAKE (4C) BY 12Z SUN. GIVEN THE DRYING...WILL NOT INCLUDE ANY PCPN
MENTION OTHER THAN LINGERING -SHRA SCNTRL. TO THE W...DEGREE OF
DRYING AND WARMER 850MB TEMPS SUGGESTS LITTLE/NO LAKE CLOUD...AND
WITH WINDS DIMINISHING UNDER DRYING COLUMN (PRECIPITABLE WATER
40-55CT OF NORMAL)...IT SHOULD BE A CHILLY NIGHT OVER THE INTERIOR
W. A FEW UPPER 30S ARE POSSIBLE IN THE TRADITIONAL COLD SPOTS.
TYPICAL FOR COOL NIGHTS AT THIS TIME OF YEAR...SOME GROUND FOG WILL
ALSO BE POSSIBLE IN LOW-LYING AREAS AROUND
RIVERS/STREAMS/LAKES/SWAMPS OVER THE INTERIOR W HALF...ESPECIALLY
WHERE RAINFALL OCCURS TODAY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM EDT SAT AUG 18 2012

SUN...MODELS HINT AT A WEAK DISTURBANCE ROTATING DOWN FM CLOSED LOW
NEAR JAMES BAY...BUT VERY DRY LOW LVLS AND WEAK DYNAMIC FORCING
SHOULD ALLOW FOR MAINLY DRY CONDITIONS ACROSS CWA. FCST H85 TEMPS FM
6C OVER THE E TO 8C OVER THE W IN LIGHT NRLY FLOW WILL SUPPORT HI
TEMPS FM MID 60S NEAR LAKE SUPERIOR TO LOWER 70S SCNTRL.

SUN NIGHT...ALTHOUGH THERE MAY BE MORE SCT MID CLDS ASSOCIATED WITH
ANOTHER DISTURBANCE APPROACHING IN NW FLOW ALF...LACK OF SIGNIFICANT
DYNAMIC SUPPORT AND OVERALL DRYNESS OF THE LLVLS SHOULD PREVENT ANY
PCPN. WITH LGT WINDS ESPECIALLY IN THE EVENING CLOSER TO SFC HI PRES
SINKING TOWARD THE LOWER GREAT LAKES...TEMPS COULD FALL INTO THE MID
TO UPPER 30S OVER SOME WRN INTERIOR COLD SPOTS WITH LOWER 40S
ELSEWHERE INLAND. DID NOT MENTION ANY PATCHY FROST FOR NOW BUT THIS
COULD BE A POSSIBILITY IF MODELS KEEP SFC RDG OVER AREA LONGER...
ALLOWING FOR LONGER PD OF GOOD RADIATIONAL COOLING. TEMPS WILL STAY
WARMER NEAR THE GREAT LAKES...IN THE UPPER 40S TO MID 50S.

MON...12Z NAM/GFS STILL GENERATE SOME LIGHT PCPN ASSOCIATED WITH
PASSAGE OF NEXT NW SHORTWAVE MOVING DOWN BACKSIDE OF MID-LVL TROF.
HOWEVER...LACK OF ANY SIGNIFICANT MOISTENING OR DEEP LYR Q-VECT CONV
AS WELL AS MARGINAL INSTABILITY (< 100 J/KG) SHOULD YIELD ONLY
PARTLY CLOUDY SKIES AND DRY CONDITIONS PER CANADIAN/ECMWF MODELS.
WITH H85 TEMPS FM 6-8C UNDER CONTINUED LIGHT NRLY FLOW...EXPECT HI
TEMPS FM MID 60S ALONG LAKE SUPERIOR TO LOWER 70S SOUTH CENTRAL.

TUESDAY THROUGH FRIDAY...LATEST 00Z RUN OF ECMWF TRENDING FARTHER
NORTH AND NOT AS DEEP WITH NEXT NW FLOW SHORTWAVE TUE NIGHT AND WED
PER CANADIAN MODEL. IT LOOKS LIKE BEST FORCING WILL STAY WELL NORTH
SO HAVE TRIMMED BACK POPS TO SLIGHT CHC TUE NIGHT INTO WEDNESDAY
NIGHT. THE GLOBAL GEM AND TO LESSER EXTENT THE ECMWF SHOW A
SHORTWAVE/VORT MAX APPROACHING FROM THE NRN PLAINS LATE THU.
INCREASING WAA IN RESPONSE TO THIS SHORTWAVE AS NOTED ON ECMWF COULD
TRIGGER SOME ISOLD SHRA/TSRA LATE THU. CHC POPS FOR CONVECTION
WARRANTED BY FRIDAY AS ECMWF AND CANADIAN MODEL ADVERTISE INCREASING
Q-VECT CONV...WAA AND DIFLUENT MID-LVL FLOW AHEAD OF SHORTWAVE
MOVING IN FM THE NRN PLAINS.
&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 138 AM EDT SAT AUG 18 2012

CLOUDS EXPECTED TO INCREASE OVERNIGHT AS UPPER DISTURBANCE
APPROACHES FROM ONTARIO. EXPECT SCT SHRA INTO CMX BY DAYBREAK THIS
MORNING AND AT SAW BY LATER THIS MORNING. BEST CHANCE FOR ANY TSRA
WOULD BE AT SAW THIS AFTERNOON...BUT KEPT MENTION OUT OF TAF AS TSRA
COVERAGE WILL BE ISOLD. CONTINUE TO KEEP SHRA OUT OF IWD AS ONLY
ISOLD COVERAGE IS EXPECTED AND DURATION WILL BE FAIRLY BRIEF.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 500 AM EDT SAT AUG 18 2012

A GENERALLY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES WILL
RESULT IN WINDS MOSTLY UNDER 20KT THRU THE MIDDLE OF THE UPCOMING
WEEK.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...VOSS
AVIATION...JLA
MARINE...ROLFSON







AREA FORECAST DISCUSSION

NWS HASTINGS NE

 1225 AM CDT SAT AUG 18 2012

.AVIATION...06Z TAF. MAIN CONCERN WILL BE TIMING THUNDERSTORMS
THROUGH THE KGRI TERMINAL AREA. STILL LOOKS LIKE THE BEST CHANCE
WILL BE DURING THE MORNING HOURS. EARLY THIS MORNING THERE HAS
BEEN SOME MID LEVEL CLOUDS DEVELOPING TO THE SOUTH OF KGRI. THEY
SHOULD STAY MAINLY SOUTH OF THE TERMINAL...BUT MAY SNEAK INTO THE
AREA LATER. SOME MID AND HIGH CLOUDS WILL LINGER AFTER THE
THUNDERSTORMS FOR A TIME...BUT GRADUALLY MOVE OUT. A WEAK COLD
FRONT WILL MOVE THROUGH AND TURN WINDS TO THE NORTHWEST DURING
THE LATE MORNING.

&&

.PREV DISCUSSION... /ISSUED 408 PM CDT FRI AUG 17 2012/

SHORT TERM...THROUGH SATURDAY DAYTIME. PRIMARY ISSUE DURING THE
NEXT 24 HOURS IS TRYING TO PIN DOWN HIGH WIDESPREAD
SHOWER/THUNDERSTORM ACTIVITY WILL BE LATE TONIGHT INTO THE DAYTIME
SATURDAY...AND THE RESULTANT EFFECTS ON HIGH TEMPERATURES.

19Z OBJECTIVE SURFACE ANALYSIS REVEALS AN INCREDIBLY PLEASANT
AFTERNOON ACROSS THE CWA WITH VERY LIGHT BREEZES...THANKS TO A
1020MB RIDGE AXIS PARKED DIRECTLY OVER THE AREA AND EXTENDING
NORTHEAST INTO MN. VISIBLE SATELLITE CONFIRMS NEARLY CLOUD-FREE
SKIES ACROSS THE NORTHEAST 1/2 OF THE CWA...WHILE IN THE
SOUTHWEST...WHAT WAS A FAIRLY SOLID MID LEVEL CLOUD DECK A FEW
HOURS AGO HAS STEADILY ERODED/SCATTERED OUT QUITE A BIT. WATER
VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM MODEL DATA DEPICTS
THE CWA UNDER SEASONABLY STRONG NORTHWEST FLOW ALOFT...SANDWICHED
BETWEEN A LARGE SCALE TROUGH OVER THE NORTHEAST CONUS WHICH IS
ANCHORED BY A VIGOROUS VORT MAX OVER EASTERN QUEBEC...AND A BROAD
RIDGE CENTERED FROM THE INTERMOUNTAIN WEST TO SOUTH TX. THE QUICK
MOVING SHORTWAVE/SPEED MAX THAT WILL BRING PRECIP CHANCES LATE
TONIGHT INTO SATURDAY IS CURRENTLY EVIDENT DROPPING SOUTHEAST NEAR
THE MT/ND/CANADA BORDER. TEMPS THIS AFTERNOON ARE VERY MUCH ON
TRACK WITH PREVIOUS FORECAST HIGHS...AND MAY ACTUALLY EXCEED THEM
SLIGHTLY IN SOME AREAS AS A FEW POTS ARE MAKING A RUN AT REACHING
80. AS SUGGESTED IN THE EARLIER UPDATE DISCUSSION...LIMITED MIXING
INTO VERY DRY AIR ALOFT HAS ALLOWED SURFACE DEWPOINTS TO FALL INTO
THE UPPER 30S IN SOME AREAS...ALTHOUGH LOW 40S ARE PREVALENT.

FOR THIS EVENING/TONIGHT...THE MOST SIGNIFICANT CHANGE WAS TO
COMPLETELY REMOVE ALL MENTION OF SHOWERS/STORMS BEFORE 06Z...AS
MOISTURE RETURN AND RESULTANT ELEVATED INSTABILITY NOW APPEARS
CONSIDERABLY MORE DELAYED THAN IT DID 24 HOURS AGO. THAT BEING
SAID...LATEST RAP-BASED HOURLY MESOANALYSIS INDICATED THE
PRESENCE OF UP TO 500 J/KG MUCAPE CURRENTLY SITTING ACROSS
SOUTHWEST ZONES ALONG THE LEADING EDGE OF MOISTURE RETURN AROUND
700MB. HOWEVER THE 12Z NAM WOULD SUGGEST THIS MUCAPE IS ACTUALLY
MORE MEAGER AND MORE CAPPED THAN THE RAP SUGGESTS...AND GIVEN THE
LIMITED FORCING AND THE FACT THAT A NUMBER OF DETERMINISTIC AND
HIGH RES MODELS SUCH AS THE 12Z 4KM WRF-NMM DO NOT INITIATE
CONVECTION IN THIS AREA THROUGH THIS EVENING...HAVE REMOVED THE
SLIGHT POPS. FOR THE LATE NIGHT 06Z-12Z PERIOD...DECIDED TO BREAK
THE POP/WX GRIDS INTO 3-HOUR BLOCKS...WITH THE PRIMARY FOCUS
SQUARELY ON THE VERY LATE NIGHT/EARLY MORNING HOURS POST-09Z. FOR
THE 06Z-09Z PERIOD...ONLY HAVE SLIGHT POPS CREEPING INTO A FEW FAR
SOUTHWEST COUNTIES. THEN AFTER 09Z...BRING IN 20-30 PERCENT
SHOWER/ISOLATED STORM CHANCES FOR ALL BUT ROUGHLY THE EASTERN 1/4
OF THE CWA. AS THE NIGHT WEARS ON...THE AFOREMENTIONED NORTHWEST
FLOW SHORTWAVE WILL REACH THE SD/NORTHERN NEB BORDER AREA...WHILE
OUT AHEAD OF IT...THETA-E ADVECTION MAINLY IN THE 850-700MB LAYER
WILL BE ON THE INCREASE...AS THE EASTERN EDGE OF A MODEST 850MB
LOW LEVEL JET VEERS INTO THE AREA. INTERESTINGLY...THE NEWLY
ARRIVED 18Z NAM KEEPS MOST ALL OF THIS ACTIVITY OUTSIDE THE CWA
UNTIL AFTER SUNRISE...BUT FEEL AT LEAST 20-30 POPS ARE WARRANTED
BASED ON THE 4KM WRF-NMM AND NSSL 4KM-WRF DEPICTION OF ONE BATCH
OF SHOWERS/FEW STORMS SLIDING INTO THE CWA FROM THE
NORTHWEST...WHILE ANOTHER POTENTIALLY SEPARATE AREA DEVELOPS OVER
THE SOUTHWESTERN CWA MAINLY IN KS. ALTHOUGH NOT ANTICIPATING A
SEVERE WEATHER THREAT THROUGH SUNRISE WITH MUCAPE LIKELY REMAINING
NO MORE THAN A FEW HUNDRED J/KG...SUPPOSE A FEW STRONGER CORES
WITH SMALL HAIL CANNOT BE RULED OUT GIVEN STRONG DEEP LAYER SHEAR
ON THE ORDER OF 50+ KNOTS. TEMP WISE TONIGHT...GIVEN THE SLOWER
ONSET OF CLOUDS AND STORM CHANCES...AND WITH WINDS REMAINING LIGHT
AS THE RIDGE AXIS SLOWLY DEPARTS...NUDGED DOWN LOWS TONIGHT 2-3
DEGREES IN MOST AREAS...WITH MUCH OF THE CWA AIMED INTO THE 50-53
RANGE...AND EVEN COOLER MID-UPPER 40S IN THE FAR EAST...BUT NOT
RECORD-BREAKING TERRITORY.

TURNING TO THE DAYTIME PERIOD 12Z-00Z...SPLIT THE DAY INTO 6-HOUR
BLOCKS FOR POPS/WEATHER...WITH THE OVERALL BEST RAIN CHANCES FOCUSED
DURING THE MORNING. ALOFT...THE COMPACT BUT FAIRLY VIGOROUS
NORTHWEST FLOW WAVE WILL DIVE SOUTHWARD ACROSS THE EASTERN HALF OF
NEBRASKA TOWARD NORTHEAST KANSAS DURING THE DAY...ACCOMPANIED BY
AN ASSOCIATED UPPER LEVEL JET STREAK. ALTHOUGH IT WILL NOT BE AN
ALL-DAY RAIN OUT BY ANY MEANS...THE CONSENSUS OF VARIOUS MODELS
INCLUDING THE 12Z 4KM WRF-NMM REFLECTIVITY SHOWS A DECENT CHANCE
FOR AT LEAST SCATTERED SHOWERS/A FEW STORMS SPREADING SOUTHEAST
ACROSS THE CWA DURING THE DAY...POSSIBLY IN TWO SEPARATE ROUNDS
WITH ONE ROUND DURING THE MORNING...FOLLOWED BY MORE HIT AND MISS
ACTIVITY DURING THE AFTERNOON DIRECTLY UNDER THE SHORTWAVE AXIS.
WITH THE OVERALL BEST COVERAGE EXPECTED DURING THE MORNING
HOURS...INCREASED POPS TO 50S ACROSS ROUGHLY THE NORTHWEST 1/2 OF
THE CWA...BUT KEPT THEM BELOW LIKELY TERRITORY FOR NOW. DURING THE
AFTERNOON...WENT LOWER WITH POPS BUT KEPT AT LEAST 20-30 PERCENT
CHANCES AND HIGHEST ACROSS THE EASTERN 1/2. AS FOR SEVERE
CHANCES...WITH BOTH ELEVATED AND NEAR SURFACE-BASED PARCELS NOT
EXPECTED TO AVERAGE MORE THAN 500 J/KG MOST AREAS...WHICH CAME IN
LOWER ON THE 18Z NAM THAN ITS 12Z RUN...NOT EXPECTING SEVERE
STORMS TO BE A BIG ISSUE. HOWEVER...GIVEN THE VIGOROUS WAVE AND
CONTINUED SEASONABLY STRONG DEEP LAYER SHEAR...AT LEAST A FEW
STRONG TO MARGINALLY SEVERE STORMS MAINLY WITH HAIL POTENTIAL TO
AROUND QUARTER SIZE ARE NOT OUT OF THE QUESTION...ESPECIALLY IN
KANSAS ZONES...AND AGREE WITH SPC ON HIGHLIGHTING THESE SOUTHERN
ZONES FOR 5 PERCENT SEVERE PROBS ON THE DAY 2 OUTLOOK. AS FOR RAIN
AMOUNTS SATURDAY...WOULD EXPECT THAT MOST PLACES WILL AVERAGE
UNDER ONE-QUARTER INCH...SO NOT A MAJOR BOOST TO DROUGHT RELIEF BY
ANY MEANS. TEMP-WISE...IT WILL BE A TRICKY BATTLE BETWEEN
WIDESPREAD CLOUDS/SCATTERED RAIN FOR THE MAJORITY OF THE DAY...BUT
POTENTIAL FOR DECENT AFTERNOON CLEARING ESPECIALLY NORTHWEST.
OVERALL MADE NO BIG CHANGES...BUT RAISED WESTERN ZONES A FEW
DEGREES...ESPECIALLY UP AROUND ORD. HAVE MOST OF THE CWA TOPPING
OUT IN THE 76-81 RANGE.

LONG TERM...STARTING SATURDAY EVENING. GUIDANCE SUGGESTS
NORTHWESTERLY UPPER LEVEL FLOW WILL PERSIST OVER THE CENTRAL
PLAINS THROUGH MUCH OF THE EXTENDED FORECAST PERIOD AS UPPER LEVEL
RIDGING REMAINS RELEGATED TO THE SOUTHWESTERN CONUS. QPF FIELDS
FROM THE SREF- MEAN...NAM AND OPERATIONAL GFS SUGGEST LINGERING
PRECIPITATION WILL BE POSSIBLE OVER OUR SOUTHEASTERN CWA 00Z-06Z
SUNDAY AS A MID LEVEL SHORT WAVE DEPARTS THE AREA. AS A
RESULT...WENT AHEAD AND KEPT 20% POPS GOING ACROSS OUR SOUTHEAST
00Z-06Z SUNDAY. A FEW SMALL-SCALE MID LEVEL PERTURBATIONS COULD
POTENTIALLY PUSH OVER THE CENTRAL PLAINS SUNDAY AND MONDAY.
DESPITE THE POSSIBILITY OF THESE SMALL-SCALE DISTURBANCES...OPTED
TO KEEP THE CWA DRY DURING THIS TIME PERIOD GIVEN THE VERY LOW
PROBABILITY OF PRECIPITATION ACTUALLY BEING REALIZED FROM ANY ONE
OF THESE FEATURES. THE EC...OPERATIONAL GFS AND GEFS-MEAN ALL
ADVERTISE A MORE SIGNIFICANT MID LEVEL SHORT WAVE WILL PUSH
SOUTHEAST ACROSS THE CENTRAL HIGH PLAINS MONDAY NIGHT INTO
TUESDAY. AT THIS TIME IT APPEARS THE BULK OF THE DPVA AND MID
LEVEL THERMAL ADVECTION WILL REMAIN SOUTHWEST OF OUR AREA...BUT
THERE MAY BE JUST ENOUGH OMEGA FOR PRECIPITATION ACROSS OUR
WEST/SOUTHWEST AND AS A RESULT...WENT AHEAD AND KEPT 20%-30% POPS
GOING ACROSS OUR WEST/SOUTHWEST FOR MONDAY NIGHT. SOME OF THIS
OMEGA MAY CREEP A BIT FARTHER EAST INTO OUR AREA DURING THE DAY
TUESDAY SO WENT AHEAD AND SPREAD POPS A BIT FARTHER EAST ACROSS
THE CWA DURING THE DAY TUESDAY AS A RESULT. AN OVERALL LACK IN
KINEMATIC FORCING SHOULD THEN PRESENT DRY CONDITIONS TO OUR AREA
TUESDAY NIGHT THROUGH THURSDAY...WITH GUIDANCE SUGGESTING YET
ANOTHER MID LEVEL SHORT WAVE WILL BRING PRECIPITATION CHANCES TO
MUCH OF THE AREA THURSDAY NIGHT INTO FRIDAY.

VERY LITTLE CHANGE IN THE LOW LEVEL AIRMASS SUGGESTS TEMPERATURES
SUNDAY THROUGH FRIDAY WILL BE FAIRLY SIMILAR...WITH PERHAPS A SLIGHT
WARMING TREND TOWARDS THE END OF THE FORECAST PERIOD. GIVEN
THIS...BELOW-NORMAL TEMPERATURES ARE FORECAST ACROSS THE CWA SUNDAY
WITH HIGHS IN THE UPPER 70S AND LOWS IN THE UPPER 40S TO NEAR 50.
SLIGHTLY WARMER BUT STILL BELOW-NORMAL TEMPERATURES ARE THEN
FORECAST FOR MUCH OF THE CWA MONDAY BEFORE WEAK LOW LEVEL WARM
ADVECTION PROVIDES NEAR TO SLIGHTLY ABOVE-NORMAL TEMPERATURES
TUESDAY ONWARD.

&&

.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS SAN ANGELO TX

 1153 PM CDT FRI AUG 17 2012

.DISCUSSION...

LOOK FOR VFR CONDITIONS TO CONTINUE ACROSS WEST CENTRAL TEXAS FOR
THE NEXT 24 HOURS. SEE AVIATION BELOW FOR DETAILS.

&&

.AVIATION...

SHOWERS AND THUNDERSTORMS ARE POSSIBLE AGAIN ACROSS WEST CENTRAL
TEXAS TOMORROW AFTERNOON AND EVENING. MODELS INDICATE DEVELOPMENT
WILL BEGIN AROUND 18Z AND CONTINUE UNTIL AROUND 06Z TOMORROW
EVENING. MEANWHILE...DISSIPATING SHOWERS WILL LINGER ACROSS MAINLY
THE NORTHERN EDWARDS PLATEAU AND NORTHWEST HILL COUNTY FOR A
COUPLE MORE HOURS. HOWEVER...IMPACT TO ANY OF OUR SOUTHERN
TERMINALS WILL BE NIL. EXPECT SOUTH TO SOUTHEAST SURFACE WINDS
DURING THE NEXT 24 HOURS AT 10 KNOTS OR LESS.

HUBER

&&

.PREV DISCUSSION... /ISSUED 643 PM CDT FRI AUG 17 2012/

DISCUSSION...
SEE AVIATION SECTION.

AVIATION...
AVIATION FORECAST FOR THIS PACKAGE LARGELY REVOLVES AROUND PLACEMENT
OF CONVECTION AND ASSOCIATED EFFECTS. ONE OF THE MAIN CHANGES WITH
THE 00Z PACKAGE IS TO REMOVE/REDUCE LONG-PERIOD /UP TO 20 HOURS AT
KSJT/ VCTS GROUPS. MOST OF THE SHOWERS AND THUNDERSTORMS THIS
EVENING HAVE BEEN ACROSS THE AREA SOUTH OF INTERSTATE 20 AND NORTH
OF INTERSTATE 10...WITHIN SUBTROPICAL MOISTURE PLUME. OVERALL
STEERING FLOW IS WEAK...BUT THE GENERAL PROPAGATION AND NEW
DEVELOPMENT HAS BEEN MOSTLY TO THE SOUTH-SOUTHEAST. FORECAST
PLACEMENT OF CONVECTION IS VERY PROBLEMATIC FOR THE NEXT 24 HOURS.
BELIEVE MOST OF THE CURRENT CONVECTION...WHICH IS SURFACE BASED AND
DIURNALLY DRIVEN...WILL DISSIPATE EARLY TONIGHT. WHILE REDEVELOPMENT
OF CONVECTION CANNOT BE RULED OUT OVERNIGHT...THE CHANCE APPEARS LOW
ENOUGH TO PRECLUDE MENTIONING IN THE AREA TAFS. A BETTER CHANCE OF
REDEVELOPMENT WILL BE DURING THE DAY SATURDAY WITH DIURNAL HEATING
AND DESTABILIZATION OF THE MOIST AIRMASS. WILL HAVE MULTIPLE OUTFLOW
BOUNDARIES ACROSS THE AREA WHICH WHERE CONVECTION MAY INITIATE. WILL
CARRY VCTS AFTER 16Z OR 17Z AT MOST IF NOT ALL TAF SITES. A FEW
STRONGER STORMS WITH GUSTS OVER 35 KT WILL BE POSSIBLE. LOCALIZED
REDUCTIONS IN VISIBILITY AND CEILING ARE ALSO POSSIBLE IN THE HEAVY
RAINFALL WHICH ACCOMPANIES THE CONVECTION. WINDS TONIGHT WILL BE
VARIABLE AT SPEEDS UNDER 10 KT. ON SATURDAY...WINDS OUTSIDE OF
CONVECTIVE INFLUENCES WILL BE MOSTLY SOUTHEAST TO SOUTH AT 5-10 KT.

PREV DISCUSSION... /ISSUED 312 PM CDT FRI AUG 17 2012/

SHORT TERM...
FOR THIS AFTERNOON INTO THIS EVENING...HAVE RAISED POPS A LITTLE
THROUGH THE REST OF THE CONCHO VALLEY. HIGH RESOLUTION RAP SOLUTION
HAS CONVECTION ACROSS THE CONCHO VALLEY THROUGH THE AFTERNOON AND
THEN DEVELOPS MORE CONVECTION ACROSS THE BIG COUNTRY. THE RAP HAS
MORE BROAD CONVECTION ACROSS THE AREA WHILE THE TEXAS TECH 3KM WRF
HAS THE ACTIVITY TOO FAR NORTH. TAKING A LOOK AT SHOWERS AND
THUNDERSTORMS THAT ARE ALREADY FORMING...THE HIGH RESOLUTION RAP
MODEL LOOKS TO BE A BETTER SOLUTION. HAVE NOT CHANGED MUCH THROUGH
THE REST OF TONIGHT AND TOMORROW. MOST OF ACTIVITY LOOKS TO BE
SCATTERED AS IT WILL BE DRIVEN BY MESOSCALE PROCESSES.

REIMER

LONG TERM...
PRECIPITATION CHANCES WILL CONTINUE THROUGH THE FIRST PART OF THE
EXTENDED FORECAST. A WEAK COLD FRONT THAT IS CURRENTLY STALLED
ACROSS WEST CENTRAL TEXAS WILL REMAIN IN THE VICINITY OF THE AREA
AND BECOME FAIRLY DIFFUSE BY LATE SATURDAY. REGARDLESS...THE FRONT
WILL SERVE AS A FOCUS FOR CONTINUED SHOWERS AND THUNDERSTORMS ACROSS
ALL OF THE REGION SATURDAY NIGHT. SATURDAY...A SHORTWAVE TROUGH WILL
SWING ACROSS THE PLAINS...ALONG THE SOUTHERN PERIPHERY OF THE MAIN
UPPER LEVEL TROUGH THAT IS FORECAST TO BE LOCATED OVER THE MIDWEST.
THIS WILL SEND A REINFORCING SHOT OF SURFACE HIGH PRESSURE DOWN THE
PLAINS AND INTO WEST CENTRAL TEXAS ON SUNDAY. THIS WILL RESULT IN
DECREASING RAIN CHANCES FROM NORTH TO SOUTH THROUGHOUT THE DAY
SUNDAY. I COOLED HIGH TEMPERATURES SUNDAY BY A DEGREE OR TWO...GIVEN
THE EXPECTED CLOUD COVER AND RAINFALL...AND THESE MAY NEED TO
EVENTUALLY BE LOWERED EVEN MORE. SUNDAY NIGHT...RAIN CHANCES WILL BE
CONFINED TO THE CONCHO VALLEY AND AREAS TO THE SOUTH. ALTHOUGH A FEW
STRONG TO SEVERE THUNDERSTORMS WILL BE POSSIBLE SATURDAY NIGHT
THROUGH SUNDAY...THE MAIN THREAT IS THE POTENTIAL FOR LOCALLY HEAVY
RAINFALL.

BEYOND SUNDAY...A SLOW WARMING TREND IS EXPECTED...WITH TEMPERATURES
BACK INTO THE MID 90S BY MID WEEK. MODELS ARE STILL INDICATING A
DISTURBANCE EMBEDDED IN THE NORTHWEST FLOW ALOFT...DROPPING THROUGH
THE TEXAS PANHANDLE MONDAY NIGHT OR TUESDAY. THIS WILL LIKELY RESULT
IN AN MCS DEVELOPING ACROSS THE PANHANDLE AND THEN MOVING SOUTHEAST.
AT THIS TIME...CONFIDENCE IS NOT HIGH ENOUGH IN THIS FEATURE
REACHING WEST CENTRAL TEXAS...SO I HAVE LEFT POPS BELOW 15 PERCENT.

DANIELS

&&

.PRELIMINARY POINT TEMPS/POPS...
ABILENE  73  95  71  90  68 /  20  50  50  30  10
SAN ANGELO  74  95  72  91  69 /  30  40  50  40  20
JUNCTION  74  97  72  92  70 /  20  30  40  40  20

&&

.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

HUBER






AREA FORECAST DISCUSSION

NWS BLACKSBURG VA

 150 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WILL CONTINUE HEADING SOUTHEAST THROUGH...AND THEN
OUT OF THE REGION TONIGHT. DEEPENING LOW PRESSURE...ANCHORED OVER
SOUTHEAST CANADA...WILL EVOLVE ACROSS THE EASTERN U.S. FOR THE
WEEKEND INTO THE FIRST HALF OF NEXT WEEK. A SERIES OF DISTURBANCES
EMBEDDED WITHIN THE UPPER LOW WILL KEEP
UNSETTLED...SHOWERY...CLOUDY...COOL CONDITIONS ACROSS MUCH OF THE
AREA UNTIL TUESDAY...WHEN DRIER CONDITIONS ALONG WITH SEASONABLE
TEMPERATURES ARE EXPECTED.

&&

.NEAR TERM /THROUGH SATURDAY/...
AS OF 120 AM EDT SATURDAY...

SCATTERED PATCHES OF -RA MOVING THROUGH FAR SW VA TOWARD THE NEW
RIVER VALLEY ASSOCIATED WITH DISSIPATING FRONTAL BOUNDARY. THIS
ACTIVITY WILL LIKELY MAKE VERY LITTLE PROGRESS PAST THE NEW RIVER
VALLEY REGION BEFORE COMPLETELY DISSIPATING. HAVE HELD ONTO TO VERY
LOW POPS FOR -SHRA GENERALLY WEST OF LWB-ROA FOR A COUPLE HOURS
LONGER THAN PREVIOUSLY INDICATED. OTHERWISE...ONLY MINOR
MODIFICATIONS TO T/TD GRIDS TO BRING MORE INTO LINE WITH CURRENT
OBS...WHICH IN GENERAL WERE A COUPLE OF DEGREES COOLER THAN PLANNED
AS A RESULT OF LESS HEATING THAN ANTICIPATED FRIDAY WITH EXTENSIVE
MID CLOUDS.

AS OF 934 PM EDT FRIDAY...

ISOLATED TO SCATTERED SHOWERS ASSOCIATED WITH A COLD FRONT HAVE
ENTERED THE FAR SOUTHWEST PORTION OF THE FORECAST AREA. LITTLE IF
ANY PRECIPITATION WAS OCCURRING ELSEWHERE. BELIEVE THE REMAINDER
OF THE NIGHT WILL WELCOME THE ISOLATED TO SCATTERED SHOWERS ALONG
THE FRONT AS IT PROGRESSES EAST OF THE CREST OF THE BLUE RIDGE.
AROUND DAYBREAK SATURDAY...GUIDANCE SUGGEST A DISTURBANCE WILL BE
RIDING ALONG THE FRONT THROUGH THE CAROLINAS. THIS MAY HAVE THE
IMPACT OF INCREASING THE COVERAGE OF SHOWERS ACROSS SOUTHSIDE
VIRGINIA AND NEIGHBORING SECTIONS OF NORTH CAROLINA AT THIS TIME.
HAVE ADJUSTED PERCENTAGE OF PRECIPITATION CHANCES AND WEATHER
GRIDS TO REFLECT THIS THINKING. HAVE ALSO TWEAKED HOURLY GRIDS FOR
TEMPERATURE...DEW POINT...AND WIND BASED UPON CURRENT CONDITIONS
AND EXPECTED TRENDS INTO EARLY SATURDAY MORNING.

AS OF 715 PM EDT FRIDAY...

HAVE TRIMMED BACK PRECIPITATION CHANCES BASED UPON THE LATEST
TRENDS OF KFCX AND OTHER NEIGHBORING 88D RADARS. FIRST LINE OF
CONVECTION WILL BE EAST OF THE FORECAST AREA BY 800 PM. NEXT LINE
OF PRECIPITATION WILL BE ASSOCIATED WITH THE ACTUAL COLD FRONT.
RADARS ARE SHOWING AN ISOLATED TO SCATTERED COVERAGE WITH THIS
ACTIVITY. ANTICIPATE COVERAGE TO BE OF A SIMILAR OR LESS COVERAGE
AS THE FRONT HEADS EAST AND ENCOUNTERS THE RELATIVELY STABLE AREA
ACROSS THE REGION...ESPECIALLY WITH THE SOON LOSS OF SUNSHINE.
HAVE ALSO ADJUSTED TEMPERATURE...DEW POINT...AND SKY COVER BASED
UPON THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
EVENING.

AS 310 PM EDT FRIDAY...

SFC COLD FRONT LOCATED TO OUR WEST FROM WESTERN PENNSYLVANIA
SOUTHWARD TO EASTERN KY. THIS FRONT WILL MOVE SOUTHEAST TONIGHT INTO
SATURDAY. CONVECTION COVERAGE SHOULD INCREASE LATE THIS AFTERNOON
INTO TONIGHT...DUE TO COMBINATION OF DIFFERENTIAL HEATING EFFECTS
AND THE APPROACH OF COLD FRONT/MID-LEVEL SHORT WAVE TROUGH. AT THIS
TIME...REGIONAL WSR-88D IMAGES SHOWED SHOWERS AND ISOLATED
THUNDERSTORMS MOVING EAST ACROSS WESTERN PORTIONS OF CWA. LOOKS LIKE
THE BEST INSTABILITY IS JUST AHEAD OF THE CLOUD DECK. SPC RECENTLY
REMOVED MUCH OF THE AREA FROM THEIR SLIGHT RISK...AND THIS SEEMS
REASONABLE...ESPECIALLY IN LIGHT OF THE WEAK SHEAR OVER THE REGION.
AN ISOLATED STRONG TO SEVERE THUNDERSTORM MAY BE POSSIBLE THIS
EVENING WITH MAIN THREAT HEAVY RAINS AND GUSTY WINDS.

THUNDERSTORMS AND SHOWERS SHOULD WANE/DIMINISH TONIGHT AS THE
UPPER SHORT WAVE SHEARS OUT AND THE MAIN DYNAMICS MOVE TOWARD NEW
ENGLAND.  ANOTHER SHORTWAVE POISED THE MOVE ACROSS THE UPPER
MIDWEST/NORTHERN PLAINS OVERNIGHT...WILL PROLONG SW FLOW ALOFT AND
DELAY ANY CLEARING. WITH PLENTY OF CLOUDS TONIGHT...PLAYED LOW
TEMPERATURES CLOSE TO THE ADJMET WITH READINGS FROM AROUND 60
DEGREES IN THE MOUNTAINS TO THE UPPER 60S TO NEAR 70 IN THE
SOUTHEAST.

THE COLD FRONT WILL MOVE SOUTH INTO NORTH CAROLINA FOR SATURDAY.
THERE IS ENOUGH MOISTURE TO COMBINED WITH WEAK UPPER LEVEL
DISTURBANCES AND SURFACE WIND CONVERGENCE TO PRODUCE SHOWERS AND A
FEW THUNDERSTORMS. HIGH TEMPERATURES ON SATURDAY WILL VARY THE MID
70S IN THE MOUNTAINS TO THE MID 80S IN THE SOUTHEAST.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 320 PM EDT FRIDAY...

COLD FRONT WILL BE DOWN IN THE CAROLINAS BY SAT NIGHT WITH DRIER AND
COOLER AIR SEEPING SOUTHBOUND ALLOWING FOR AN EXODUS OF MOST
LEFTOVER SHRA OVER THE SOUTH SAT EVENING. NEXT MID LEVEL IMPULSE
PROGGED BY MOST MODELS WILL ROUND THE 5H TROF SLIDING THRU THE UPPER
MIDWEST SUNDAY AND DAMPEN UPON PASSING INTO THE OHIO VALLEY SUNDAY
NIGHT. DEEPER MOISTURE WITH THE RESIDUAL FRONT LOOKS TO REMAIN JUST
SOUTH OF THE CWA THOUGH AS OVERALL MID LEVEL BACKING OF THE FLOW
AHEAD OF THE WAVE APPEARS WEAK ATTM. HOWEVER WITH LOW LEVEL
TRAJECTORIES TURNING MORE SOUTH/SE AND A RIBBON OF HIGHER SFC-85H
THETA-E SPREADING ALONG/EAST OF THE BLUE RIDGE...WENT AHEAD AND
EXPANDED THE CHANCE POPS NORTH SUNDAY/SUNDAY EVENING...WITH BEST
COVERAGE SOUTHERN HALF WHERE SOME CAPE WILL EXIST. SHRA MAY LINGER
EAST SUNDAY NIGHT AND BUBBLE BACK TO THE WEST ON MONDAY AS YET
ANOTHER UPPER LEVEL DISTURBANCE SPINS BY AND PERHAPS INDUCES A SFC
WAVE ALONG THE FRONT TO THE SOUTH MONDAY AFTERNOON PER THE LATEST
CANADIAN. AGAIN MAINLY MIDDLE RANGE CHANCE POPS FOR NOW GIVEN
UNCERTAINTY AND ONLY SLIGHT POPS FAR WEST/NW WHERE REMOVED FROM THE
DEEPER RH. OTRW MORE CLOUDS SOUTH/EAST AND PERHAPS MORE
BREAKS/CLEARING AT TIMES NORTH-NW THRU MONDAY. CLOUDS/SHRA SHOULD
KEEP HIGHS MAINLY IN THE 70S TO LOW 80S WITH LOWS 50S TO LOW 60S
MOUNTAINS...AND 60-65 BEHIND THE FRONT OUT EAST.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1215 PM EDT FRIDAY...

UPPER TROF ACROSS THE EAST WILL GRADUALLY WEAKEN AND START TO LIFT
OUT BY LATE IN THE WEEK AS WEAK SURFACE HIGH PRESSURE REMAINS IN
PLACE. HOWEVER MODELS SUGGEST THAT A 5H IMPULSE ROTATING AROUND THE
DEPARTING TROFFINESS THRU THE MID MISS VALLEY...COULD EVOLVE INTO A
WEAK UPPER LOW BY MID WEEK WHICH MAY SLIP EAST INTO THE CENTRAL
APPALACHIANS BY FRIDAY. THIS QUITE UNCERTAIN AND MAINLY SUPPORTED BY
THE LATEST ECMWF...BUT WOULD BE ENOUGH TO LIKELY ENHANCE CONVECTIVE
CHANCES LATER IN THE WEEK DESPITE WEAK RIDGING IN PLACE. OTRW TREND
IN THE OVERALL FORECAST REMAINS ON THE DRY SIDE WITH THE RESIDUAL
AXIS OF DEEPER MOISTURE STILL TO THE SE...AND CONTINUED DRIER NORTH
TO NE FLOW IN PLACE. THIS LOW LEVEL ONSHORE FLOW COULD BRING IN SOME
LOW CLOUDS TO ALONG THE BLUE RIDGE AT TIMES DURING THE OVERNIGHTS
BUT IFFY. OTRW INTERVALS OF CLOUDS AND SUN THRU THE PERIOD WITH
MAINLY DIURNALLY DRIVEN SLIGHT CHANCE CONVECTIVE POPS ESPCLY SW AND
MOUNTAINS WHERE AIDED BY LOCAL CONVERGENCE. COVERAGE PERHAPS A BIT
MORE LATE IN THE WEEK OVER THE SOUTH IF THE WEAK CUTOFF DEVELOPS AND
BETTER MOISTURE GETS RETURNED NORTH. TEMPS MAINLY PERSISTENCE THRU
THE PERIOD UNDER HIGH PRESSURE/LIGHT WINDS...AND ONLY SLIGHT WARMING
ALOFT...WITH HIGHS 70S TO ARND 80 MOUNTAINS AND LOW/MID 80S EAST.

&&

.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 150 AM EDT SATURDAY...

MOSTLY VFR CONDITIONS EXPECTED THIS TAF VALID PERIOD. SPOTTY -RA
NOTED ACROSS SW VA TOWARD BCB/ROA...WILL LIKELY DISSIPATE BY 08Z.
THIS IS ASSOCIATED WITH THE DISSIPATING FRONTAL BOUNDARY AS IT LOSES
UPPER SUPPORT TO CONTINUE MUCH FURTHER EAST PROGRESS. TYPICAL
UPSLOPE FLOW NOTED ON THE WV SIDE RESULTING IN IFR CIGS/VSBYS AGAIN
AT BLF...WITH FOG DEVELOPING AT LWB. EXPECT IFR CIGS/VSBYS AT
LWB/BLF OVERNIGHT...OTHERWISE VFR AFT 13Z THERE AS WELL. EXTENSIVE
MID CLOUDS WILL LINGER ACROSS THE EASTERN 2/3RD OF THE CWA TODAY AND
IMPACT MOST TAF SITES WITH BKN-OVC CIGS...YET AOA080 IN ALL CASES
AFT 13Z. WINDS WILL VEER TO THE NE THROUGH THE DAY...ESPECIALLY EAST
OF THE BLUE RIDGE...WITH VRB03KT PREVAILING WEST OF THE BLUE RIDGE
THROUGH MOST OF THE TAF VALID PERIOD.

AS OF 830 PM EDT FRIDAY...

SHOWERS AND THUNDERSTORMS HAVE MAINLY EXITED THE REGION AS OF 00Z.
THE EXCEPTION IS SOME VERY LIGHT RAIN SHOWERS MOVING ACROSS WESTERN
VIRGINIA AS A WEAK DISTURBANCE PASSES BY. LEFT A CHANCE OF RAIN AT
BLF THROUGH 02Z. THE HRRR FORECAST MODEL SHOWS ANY SHOWERS THAT
DEVELOP ALONG THE COLD FRONT WILL DISSIPATE EAST OF THE BLUE RIDGE
TONIGHT THANKS TO THE NORTHWESTERLY DOWNSLOPE FLOW.

WESTERLY FLOW WILL PROMOTE LOW CEILINGS AT LWB AND BLF...AND
POSSIBLY FOR A SHORT TIME AT BCB...IFR CONDITIONS ARE EXPECTED
DURING THE EARLY MORNING HOURS ON SATURDAY. A DOWNSLOPE FLOW FURTHER
EAST TONIGHT SHOULD KEEP CEILINGS AT ROA/LYH/DAN FROM DROPPING BELOW
3KFT DURING THE EARLY MORNING HOURS...ALTHOUGH LIGHT RAIN EARLIER
THIS EVENING MAY CAUSE LIGHT FOG TO DEVELOP BEFORE SUNRISE. BY 15Z
SATURDAY ALL TAF LOCATIONS WILL RETURN TO VFR CONDITIONS AS DAYTIME
HEATING INCREASES...ERODING THE REMAINING LOW CLOUDS.

A DEVELOPING LOW PRESSURE SYSTEM ACROSS EASTERN CANADA WILL KEEP OUR
REGION UNSETTLED THROUGH THE EARLY PART OF NEXT WEEK. VFR CONDITIONS
ARE EXPECTED FOR THE MAJORITY OF THE PERIOD...WITH ISOLATED IFR/MVFR
CONDITIONS POSSIBLE WHERE SHOWERS AND THUNDERSTORMS DEVELOP.

&&

.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.

&&

$$
SYNOPSIS...DS/KK/RAB
NEAR TERM...RAB/DS/KK
SHORT TERM...JH
LONG TERM...JH
AVIATION...RAB/CF/KK/NF










AREA FORECAST DISCUSSION

NWS CHEYENNE WY

 1128 PM MDT FRI AUG 17 2012

.AVIATION...06Z TAF ISSUANCE...
WINDS WILL SHIFT TO NORTHERLY BEHIND A COLD FRONT WHICH WILL MOVE
ACROSS THE AREA TONIGHT. HIGH PRESSURE AXIS TO MOVE ACROSS THE
AREA LATE TONIGHT AND EARLY SATURDAY. SOME BREEZY CONDITIONS
SATURDAY AFTERNOON WITH WINDS GUSTS 15 TO 25 MPH BUT THEN WINDS
TO AGAIN BECOME LIGHT SATURDAY NIGHT. A FEW STRAY SHOWERS POSSIBLE
LATE THIS EVENING OVER SOUTHEAST WY...OTHERWISE DRY WITH VFR
THROUGH SATURDAY NIGHT.

&&

.PREV DISCUSSION... /ISSUED 705 PM MDT FRI AUG 17 2012/

DISCUSSION...
SURFACE COLD FRONT APPEARED TO BE ROUGHLY FROM EAST OF KCDR TO
NEAR KEAN AT 00Z.  HOWEVER...WINDS FURTHER SOUTH HAVE TURNED TO
MORE NORTHEAST AS WELL IN MUCH OF SOUTHEAST WYOMING.  THE FRONT
SHOULD MOVE THROUGH THE ENTIRE CWA BY 09Z.  ATMOSPHERE IS DRY
AND RELATIVELY STABLE EARLY THIS AFTERNOON OVER THE CWA.  SOME
WEAK RETURNS WERE OBSERVED AROUND 2330Z ON THE COLORADO BORDER
SOUTH OF LARAMIE.  ADDITIONAL DEVELOPMENT SEEMS UNLIKELY THE REST
OF TONIGHT...SO HAVE TAKEN OUT THE MENTION OF SHOWERS AND STORMS
IN A RECENT UPDATE.  OTHERWISE...ONLY MINOR FIRST PERIOD CHANGES
WERE MADE TO THE FORECAST.

PREV DISCUSSION... /ISSUED 249 PM MDT FRI AUG 17 2012/

.SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT...
WATER VAPOR IMAGERY SHOWS FAST NORTHWEST FLOW ALOFT OVER THE WY/MT
WITH A STRONG SHORTWAVE DIVING SOUTHWARD OVER SASKATCHEWAN. CUMULUS
HAVE DEVELOPED OVER THE LARAMIE RANGE BUT FAILED TO MOVE EASTWARD
OVER THE PLAINS. THE MODELS ARE IN AGREEMENT IN SHOWING THE
SHORTWAVE DIVING SSE OVER THE NORTHERN PLAINS THROUGH TONIGHT.
ALTHOUGH THERE IS LIMITED LOW AND MID LEVEL MOISTURE TO WORK
WITH...THE QG LIFT AHEAD OF THE SHORTWAVE COULD ENHANCE CONVECTIVE
CHANCES LATE THIS AFTERNOON AND EVENING. CURRENT LAPS ANALYSIS SHOWS
WEAK SFC INSTABILITY OVER THE PLAINS (WITH A FEW HUNDRED J/KG OF
CAPE).  BOTH THE GFS AND HRRR MODELS GENERATE ISOLATED STORMS OVER
THE SOUTHEASTERN PART OF THE CWA BETWEEN 00Z AND 06Z. KEPT SLIGHT
CHANCE POPS FOR MAINLY AREAS ALONG INTERSTATE 80 TO THE EAST OF THE
LARAMIE RANGE THROUGH EARLY TONIGHT. A 1018MB SFC HIGH BEHIND THE
SHORTWAVE WILL DRIVE A COLD FRONT THROUGH THE AREA LATE TONIGHT.
BREEZY CONDITIONS WILL DEVELOP SAT MORNING AFTER THE FROPA...HOWEVER
PRESSURE RISES/SOUNDINGS DO NOT SUGGEST THAT THE WINDS WILL BE
PARTICULARLY STRONG.

RATHER QUIET THROUGH THE REMAINDER OF THE SHORT TERM WITH VERY DRY
NORTHWESTERLY FLOW ALOFT. HIGHS ON SAT WILL BE AROUND 5 DEGREES
COOLER IN THE POST FRONTAL AIRMASS. THE BREEZY NORTHERLY WINDS
WILL SUBSIDE ON SAT NIGHT AS THE SFC HIGH PRESSURE CENTER SETTLES
OVER THE CWA. WENT A FEW DEGREES COOLER THAN MOS FOR LOWS ON SAT
NIGHT...WITH VALUES MAINLY IN THE MID-TO-UPPER 40S OVER THE
PLAINS...WITH GOOD RADIATION AL COOLING POTENTIAL. 700MB TEMPS RISE
ON SUN TO 9C (FROM 7C ON SAT) FOR A FEW DEGREES OF WARMING...BUT
LITTLE OTHER CHANGE IN THE SENSIBLE WEATHER. A SHORTWAVE WILL
ROUND THE TOP OF THE INTERMOUNTAIN WEST RIDGE ON SUN
NIGHT...APPROACHING THE CWA BY MON.

.LONG TERM...MONDAY THROUGH FRIDAY...
LONG TERM GENERALLY DOMINATED BY A RIDGE OF HIGH PRESSURE WITH THE
RIDGE AXIS WEST OF THE CWA EARLY. WE GET A SHORTWAVE THAT MOVES DOWN
THROUGH THE NORTHWEST FLOW MONDAY...EXITING EAST BY MONDAY
AFTERNOON. GENERALLY DRY CONDITIONS EXPECTED WITH THE EXCEPTION
POSSIBLY BEING THE HIGHER TERRAIN OF THE SNOWY...SIERRA MADRE AND
NORTHERN LARAMIE RANGES MONDAY AFTERNOON.

RIDGE AXIS THEN BUILDS OVER THE CWA TUESDAY WITH THE AXIS SHIFTING
EAST BY TUESDAY AFTERNOON. COULD SEE AN INCREASE IN FIRE WEATHER
CONCERNS AS WINDS SHIFT SOUTHWEST AND BEGIN TO INCREASE. GFS
SHOWING 20 TO 25KT OF WIND AT 700MB AS ANOTHER SHORTWAVE TRACKS
INTO IDAHO AND NORTHERN UTAH. THIS SHORTWAVE TRACKS NORTHEAST
ACROSS WESTERN WYOMING TUESDAY NIGHT INTO WEDNESDAY...DRAGGING A
COLD FRONT THROUGH AT LEAST OUR WESTERN ZONES WEDNESDAY EVENING.
MAINTAINED...AND SLIGHTLY INCREASED POP COVERAGE FOR THIS AREA
WEDNESDAY NIGHT. WEDNESDAY MOST LIKELY OUR WARMEST DAY NEXT WEEK
WITH HIGHS CLIMBING BACK INTO THE 90S WITH THESE GUSTY WINDS. DRIER
CONDITIONS RETURNING FOR THE END OF THE WEEK CWA WIDE.

&&

.FIRE WEATHER...
FIRE WEATHER CONCERNS WILL BE MINIMAL THROUGH THE WEEKEND. A COLD
FRONT WILL MOVE ACROSS THE AREA TONIGHT BRINGING BREEZY NORTHERLY
WINDS AND COOLER THAN AVERAGE TEMPERATURES ON SATURDAY. MINIMUM
AFTERNOON RELATIVE HUMIDITY VALUES WILL BE IN THE 15 TO 20 PERCENT
RANGE. THE AIRMASS WILL BEGIN TO WARM ON SUNDAY WITH AFTERNOON
HUMIDITIES DROPPING BELOW 15 PERCENT TO THE WEST OF THE LARAMIE
RANGE. HOWEVER...WINDS WILL BE LIGHT WITH THE SURFACE HIGH PRESSURE
CENTER NEAR SOUTHEAST WYOMING. PRECIPITATION CHANCES WILL BE LOW
THROUGH EARLY NEXT WEEK WITH A DRY AIRMASS IN PLACE...HOWEVER SOME
ISOLATED SHOWER AND THUNDERSTORMS WILL BE POSSIBLE STARTING MONDAY
OVER THE MOUNTAINS.

&&

.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.

&&

$$

SHORT TERM/FIRE WEATHER...RE
LONG TERM/AVIATION...MAJ
PREVIOUS DISCUSSIONS...MSW/SML/GCC/ZAF








AREA FORECAST DISCUSSION...UPDATE

NWS PEACHTREE CITY GA

 1042 AM EDT SAT AUG 18 2012

.MID MORNING UPDATE...
LATEST SURFACE MAP SHOWS A COLD FRONT NEARLY STALLED ACROSS NORTH
GA...JUST NORTH OF ATLANTA. A NEARLY ZONAL FLOW ALOFT SUGGEST THE
FRONT MAY ONLY SAG SLIGHTLY SOUTHWARD TODAY... AND THIS WOULD PUT IT
OVER METRO ATLANTA DURING DAYTIME HEATING. THE LATEST HRRR MODEL
SHOWS CONVECTION FIRING ALONG THE FRONT RIGHT OVER ATLANTA AREA BY
21-22Z TODAY...WHILE THE LOCAL WRF MODEL SHOWS SCATTERED CONVECTION
NEAR ATLANTA AND SOUTHWARD. ONGOING CONVECTION CURRENTLY PUSHING
ACROSS NE GA AND ANOTHER AREA PUSHING INTO THE LA GRANGE AREA FROM
ALABAMA WILL CONTINUE TO WEAKEN...BUT EXPECT DIFFERENTIAL HEATING
FROM CLOUD FREE AREAS TO THE EAST AND SOUTH OF THIS CONVECTION TO
PROVIDE A FOCUS FOR STORM DEVELOPMENT LATER TODAY...ESPECIALLY AS
WEAK DISTURBANCES ALOFT TRAVERSE THE STATE FRONT THE WEST. MOISTURE
AND INSTABILITY ARE SUFFICIENT TO SUPPORT SCATTERED STORMS WITH A
MODIFIED 12Z SOUNDING SHOWING AROUND 2500 J/KG OF CAPE WITH 1.70
PW`S AND ALMOST -6 LI`S. WILL UPDATE ZONES TO INCREASE POPS TO THE
30-40% RANGE FROM AREAS JUST NORTH OF ATLANTA SOUTHWARD THROUGH THE
AFTERNOON AND HOLD ONTO A LOW CHANCE ACROSS PARTS OF CENTRAL GA
THROUGH THE EVENING HOURS. WITH THE FRONT STALLING ACROSS THE AREA
OVERNIGHT... WILL ALSO HOLD ONTO A SLIGHT CHANCE POP MOST AREAS
OVERNIGHT. AT THIS TIME... NOT EXPECTING SEVERE...BUT CANNOT RULE
OUT A FEW STRONG STORMS PRODUCING 45 MPH WIND GUSTS...SMALL HAIL AND
FREQUENT LIGHTNING. THE STRONG STORM THREAT SHOULD GREATLY DIMINISH
BY 9-10 PM THIS EVENING WITH LOSS OF HEATING.

.PREVIOUS DISCUSSIONS ISSUED AT 426 AM EDT SAT AUG 18 2012/...

SHORT TERM /TODAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SAG SOUTH AND EASTWARD...AND RADAR SHOWING A
FEW SHOWERS ALONG BOUNDARY OVER NORTHERN ALABAMA AND EASTERN
TENNESSEE. SOME DEVELOPMENT HAS STARTED IN NORTHERN GEORGIA. MODELS
SHOWING SOMEWHAT DIFFERENT SOLUTIONS...IN THAT THE NAM WEAKENS THE
BOUNDARY WITH LITTLE MOISTURE OVER THE AREA TODAY. AS SHORT WAVES
MOVE ALONG THE BOUNDARY AND TOWARD THE COAST...IT OFFERS LITTLE
CHANCE OF PRECIP. SUNDAY ANOTHER WAVE MOVES ALONG THE BOUNDARY
BRINGING A GREATER ABUNDANCE OF MOISTURE TO THE AREA SUNDAY...AT
LEAST TO CENTRAL GEORGIA...WHILE THE AIR MASS REMAINS RELATIVELY DRY
OVER THE NORTH. THIS WEAK RIDGE OF HIGH PRESSURE IN THE LOWER
EASTERN TENNESSEE VALLEY PUSHES A DRIER AIR MASS INTO NORTH GEORGIA
WHILE MOISTURE LINGERS TO THE SOUTH. THE GFS HAS THE FRONT MOVING IN
THIS MORNING AS WELL BUT WITH A DRIER AIR MASS BEHIND IT TOO.
HOWEVER...GFS HAS THE MOISTURE INCREASING FOR SUNDAY INTO SUNDAY
NIGHT WITH NO DRY AIR INVASION FROM THE NORTH.

GREAT UNCERTAINTY WITH THIS FORECAST BEYOND TODAY. THE THINKING IS
THAT THE FRONT...THOUGH WEAKENING WILL PUSH INTO GEORGIA AND STALL
OVER MIDDLE GEORGIA THIS AFTERNOON TO GIVE A CHANCE OF SHOWERS...
POSSIBLY THUNDERSTORMS FOR THE AREA. SOME SHOWERS ARE ALSO POSSIBLE
ALONG THE FRONT AT IT MAKES ITS WAY SOUTH.

MOS TEMPERATURES LOOK TO BE CLOSE IN AGREEMENT WITH PREVIOUSLY
OBSERVED TEMPERATURES. HENCE...LITTLE CHANGE FROM MOS
TEMPERATURES.

37

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CWA REMAINS UNDER THE INFLUENCE OF A LONGWAVE TROUGH AT THE
BEGINNING OF THE LONG TERM. LATEST GUIDANCE STILL BRINGS A WAVE
ACROSS THE CWA NEAR THE BEGINNING OF THE LONG TERM BUT ABOUT 12
HOURS EARLIER THAN SUGGESTED YESTERDAY WITH MODELS SHOWING SUNDAY
NIGHT NOW. ALTHOUGH NAM/GFS/ECMWF/SREF SHOW SOME REFLECTION OF A SFC
LOW ASSOCIATED WITH THIS DISTURBANCE...THE GFS IS BY FAR THE
STRONGEST AND APPEARS TO BE OVERDONE ON STRENGTH AND PRECIP. AT
LEAST THROUGH MONDAY...LEANED TOWARD THE NAM/ECMWF SOLUTION TO
ACCOUNT FOR THE OVERDONE GFS. MAIN IMPACT WAS TO POPS THAT ARE IN
THE SLIGHT CHANCE TO LIKELY CATEGORY THROUGH MONDAY AS OPPOSED TO
THE LIKELY AND CATEGORICAL POPS SUGGESTED BY THE GFS. AFTER THE
INFLUENCES FROM THE WAVE ON MONDAY MOVES OUT OF THE CWA...RAIN
CHANCES DECREASE. BEST MOISTURE REMAINS ACROSS SOUTHERN HALF OF CWA
SO HAVE CONTINUED TO SHOW BEST POPS ACROSS THAT AREA. BY
MIDWEEK...LONGWAVE TROUGH CONTINUES TO BREAK DOWN ACROSS THE AREA
AND BEST MOISTURE CONTINUES TO SHIFT OFF TO THE EAST AS HIGH
PRESSURE PUSHES INTO THE CWA AT THE SFC. THIS WILL HELP TO LIMIT
POPS TO SLIGHT CHANCE ACROSS THE NORTH AND CHANCE ACROSS THE
SOUTHERN HALF OF THE CWA.

MEX MAX TEMPS ARE SLIGHTLY HIGHER THAN PREVIOUS RUN. LIKE THIS TREND
AND HAVE EVEN NUDGED MAX TEMPS UP A DEGREE IN SOME PLACES. MIN TEMPS
APPEAR A LITTLE COOL DURING THE WORK WEEK...SO HAD TO MAKE SOME
ADJUSTMENTS UPWARD HERE TOO.

11

&&

.AVIATION...
15Z UPDATE...
SOME SHOWERS OVER NORTHERN GEORGIA HAVE BROUGHT IN CIGS SCT030 TO
BKN045. VFR CONDITIONS CURRENTLY OVER ALL TAF SITES. CONVECTION OVER
ALABAMA EXPECTED TO BRING CLOUDS AND POSSIBLY SHOWERS INTO VICINITY
OF NORTHERN TAFS...IT IT HOLDS TOGETHER. FRONT TO PUSH INTO ATLANTA
AREA DURING THE AFTERNOON... WITH AN ACTIVE WESTERLY FLOW ALOFT.
HRRR MODEL INDICATES CONVECTION WILL FIRE ALONG THE FRONT AND BRUSH
THE ATLANTA AREA TAF SITES BY 21-22Z. WILL UPDATE TO INCLUDE TEMPO
-TSRA 21-00Z FOR ATLANTA AREA TAFS. CSG AND MCN TAFS ALREADY SHOW
AFTN TSRA THREAT.

//ATL CONFIDENCE...
15Z UPDATE...
MODERATE CONFIDENCE ON CONVECTION AND TIMING. HIGH CONFIDENCE ON
ALL OTHER ELEMENTS.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          89  69  89  67 /  20  10  50  50
ATLANTA         86  70  85  69 /  20  20  50  40
BLAIRSVILLE     82  60  80  64 /  20  10  20  50
CARTERSVILLE    87  65  86  65 /  20  20  40  40
COLUMBUS        90  72  90  70 /  20  20  50  50
GAINESVILLE     85  68  85  67 /  20  10  40  50
MACON           91  72  91  70 /  20  20  50  50
ROME            88  66  88  66 /  20  20  40  30
PEACHTREE CITY  86  68  87  67 /  20  20  50  40
VIDALIA         91  73  90  72 /  20  20  40  50

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...37
LONG TERM....11
AVIATION...37












AREA FORECAST DISCUSSION

NWS LINCOLN IL

 1013 AM CDT SAT AUG 18 2012

.DISCUSSION...
ISSUED 1013 AM CDT SAT AUG 18 2012

MADE A FEW MINOR TWEEKS TO TEMP GRIDS FOR TODAY.
OTHERWISE...FORECAST LOOKS ON TRACK.

HIGH PRESSURE IS CENTERED OVER THE MIDWEST TODAY PROVIDING DRY
CONDITIONS AND CALM WINDS. HIGH CLOUDS ASSOCIATED WITH DYING
MESOSCALE COMPLEX OVER THE CENTRAL MISSOURI VALLEY WILL GRADUALLY
SPREAD INTO THE AREA...BUT SHOULD ONLY HAVE A MINIMAL IMPACT ON TEMPS.

BARKER
&&

.AVIATION...
ISSUED 652 AM CDT SAT AUG 18 2012

SHALLOW GROUND FOG HAS FORMED AT DAYBREAK THIS MORNING IN A FEW
LOCATIONS IN CENTRAL AND EASTERN IL...BUT NOT AT THE TAF SITES. A
FEW SPOTS MAY DIP TOWARD LIFR CONDITIONS WITH FOG BETWEEN 12Z AND
14Z. HOWEVER THIS WILL BE ISOLATED AND SHORT LIVED. THE CHANCES
ARE SLIM THAT THIS WILL OCCUR AT THE TAF SITES IN CENTRAL AND
EASTERN IL...BUT WILL KEEP A CLOSE EYE ON THIS.

OTHERWISE...VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS.
FORECAST SOUNDINGS IN BUFKIT AND THE HRRR CLOUD BASE PROG BOTH
INDICATE THAT A FEW CUMULUS ARE POSSIBLE VERY LATE THIS MORNING
AND DURING THE AFTERNOON...PARTICULARLY IN THE EAST CENTRAL IL.

A SHORTWAVE TROF CURRENTLY IN THE NORTHERN PLAINS IS EXPECTED TO
DIG INTO THE MEAN UPPER TROF POSITION EAST OF THE MS RIVER BY THIS
EVENING. THE ATMOSPHERE WILL BE FAIRLY MOISTURE STARVED...BUT
THERE SHOULD BE ENOUGH LIFT TO PRODUCE AT LEAST A BROKEN AC LAYER
AROUND 10K FT OR SO FROM DUSK THROUGH THE OVERNIGHT HOURS.

MILLER
&&

.PREV DISCUSSION...
ISSUED 356 AM CDT SAT AUG 18 2012
RELATIVELY QUIET WEATHER PATTERN OVERALL. HIGH PRESSURE STILL IN
PLACE OVER THE REGION...WITH A EXPANSIVE TROF STRETCHING FROM THE
NRN PLAINS TO THE NRN ATLANTIC COAST. COOLER AIR IN THE REGION AND
VERY LITTLE MOISTURE FOR MUCH OF THE FORECAST. ISSUES WITHIN THE
MODELS CONFINED TO SUNDAY AND SUNDAY NIGHT WITH SOME QPF REPORTED
IN THE NAM AND GFS. HOWEVER...RH FIELDS DO NOT SEEM TO BACK THIS
UP...AND WOULD LIKE TO KEEP THE POPS TO A MIN AT LEAST ONE MORE
RUN. FORECAST A RATHER CONSERVATIVE ONE.

SHORT TERM...TODAY AND TOMORROW...
COOLER AIR REMAINING IN PLACE THROUGH THE WEEKEND AND FIRST
PORTION OF THE WORK WEEK WITH 850MB TEMPS IN THE 11C-13C RANGE AND
SFC TEMPS IN THE UPPER 70S/LOWER 80S WITH PLENTY OF SUNSHINE.
MOISTURE THROUGH THE COLUMN A BIT OF A TRICKY SITUATION. MODELS
PUSHING QPF THROUGH TOMORROW AND INTO MONDAY WITH A WEAK STORM
SYSTEM MOVING INTO THE OHIO RIVER VALLEY ON SUN. HOWEVER...MODEL
SOUNDINGS DO NOT BACK UP THE WIDESPREAD RAINFALL/QPF. KEEPING A
SLIGHT CHANCE IN THE GRIDS FOR SURE...STARTING THE TREND SHOULD
SUBSEQUENT MODEL RUNS BACK IT UP AND BRING THE RH FIELDS AROUND.
OTHERWISE...MAYBE A SPRINKLE MENTION IS ALL THAT WILL BE NEEDED.
SFC LOW AT THIS POINT WELL TO THE SOUTH AND THE EAST IN THE GFS
AND MORE DIFFUSE IN THE NAM TO WARRANT A WIDESPREAD HIGH POP.

LONG TERM...MONDAY THROUGH FRIDAY...
DEEPER EASTERN TROF AND THERMAL TROF MOVES OUT TO THE EAST LATE
WED/THURSDAY...RESULTING IN WARMEST DAY OF THE WEEK FOR THURSDAY.
850MB TEMPS 16-18C IN ECMWF AS THE WARMTH OVER THE WESTERN HALF OF
THE CONUS SHIFTS EAST SLIGHTLY INTO THE MIDWEST. FOR NOW...TEMPS
IN THE EXTENDED ON THU AND FRI IN THE MID-UPPER 80S. SUN ANGLE
DROPPING...LENGTH OF DAY SHORTENING...LESS TIME TO GET INTO THE
90S...THOUGH THE HEAT OVER THE WESTERN HALF OF THE CONUS IS
AVAILABLE AND OPEN AND WILL HAVE TO BE WATCHED CLOSELY. FOR NOW...
ENOUGH REASONS AGAINST TOPPING GUIDANCE...WILL LEAVE THE 80S
ALONE. QUIET FORECAST AS FAR AS POPS...WITH SOME WEAK POPS SHOWING
UP GOING INTO NEXT WEEKEND IN BOTH THE GFS AND THE ECMWF.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$









AREA FORECAST DISCUSSION

NWS LINCOLN IL

 653 AM CDT SAT AUG 18 2012

.DISCUSSION...
ISSUED 356 AM CDT SAT AUG 18 2012
RELATIVELY QUIET WEATHER PATTERN OVERALL. HIGH PRESSURE STILL IN
PLACE OVER THE REGION...WITH A EXPANSIVE TROF STRETCHING FROM THE
NRN PLAINS TO THE NRN ATLANTIC COAST. COOLER AIR IN THE REGION AND
VERY LITTLE MOISTURE FOR MUCH OF THE FORECAST. ISSUES WITHIN THE
MODELS CONFINED TO SUNDAY AND SUNDAY NIGHT WITH SOME QPF REPORTED
IN THE NAM AND GFS. HOWEVER...RH FIELDS DO NOT SEEM TO BACK THIS
UP...AND WOULD LIKE TO KEEP THE POPS TO A MIN AT LEAST ONE MORE
RUN. FORECAST A RATHER CONSERVATIVE ONE.

SHORT TERM...TODAY AND TOMORROW...
COOLER AIR REMAINING IN PLACE THROUGH THE WEEKEND AND FIRST
PORTION OF THE WORK WEEK WITH 850MB TEMPS IN THE 11C-13C RANGE AND
SFC TEMPS IN THE UPPER 70S/LOWER 80S WITH PLENTY OF SUNSHINE.
MOISTURE THROUGH THE COLUMN A BIT OF A TRICKY SITUATION. MODELS
PUSHING QPF THROUGH TOMORROW AND INTO MONDAY WITH A WEAK STORM
SYSTEM MOVING INTO THE OHIO RIVER VALLEY ON SUN. HOWEVER...MODEL
SOUNDINGS DO NOT BACK UP THE WIDESPREAD RAINFALL/QPF. KEEPING A
SLIGHT CHANCE IN THE GRIDS FOR SURE...STARTING THE TREND SHOULD
SUBSEQUENT MODEL RUNS BACK IT UP AND BRING THE RH FIELDS AROUND.
OTHERWISE...MAYBE A SPRINKLE MENTION IS ALL THAT WILL BE NEEDED.
SFC LOW AT THIS POINT WELL TO THE SOUTH AND THE EAST IN THE GFS
AND MORE DIFFUSE IN THE NAM TO WARRANT A WIDESPREAD HIGH POP.

LONG TERM...MONDAY THROUGH FRIDAY...
DEEPER EASTERN TROF AND THERMAL TROF MOVES OUT TO THE EAST LATE
WED/THURSDAY...RESULTING IN WARMEST DAY OF THE WEEK FOR THURSDAY.
850MB TEMPS 16-18C IN ECMWF AS THE WARMTH OVER THE WESTERN HALF OF
THE CONUS SHIFTS EAST SLIGHTLY INTO THE MIDWEST. FOR NOW...TEMPS
IN THE EXTENDED ON THU AND FRI IN THE MID-UPPER 80S. SUN ANGLE
DROPPING...LENGTH OF DAY SHORTENING...LESS TIME TO GET INTO THE
90S...THOUGH THE HEAT OVER THE WESTERN HALF OF THE CONUS IS
AVAILABLE AND OPEN AND WILL HAVE TO BE WATCHED CLOSELY. FOR NOW...
ENOUGH REASONS AGAINST TOPPING GUIDANCE...WILL LEAVE THE 80S
ALONE. QUIET FORECAST AS FAR AS POPS...WITH SOME WEAK POPS SHOWING
UP GOING INTO NEXT WEEKEND IN BOTH THE GFS AND THE ECMWF.



&&

.AVIATION...
ISSUED 652 AM CDT SAT AUG 18 2012

SHALLOW GROUND FOG HAS FORMED AT DAYBREAK THIS MORNING IN A FEW
LOCATIONS IN CENTRAL AND EASTERN IL...BUT NOT AT THE TAF SITES. A
FEW SPOTS MAY DIP TOWARD LIFR CONDITIONS WITH FOG BETWEEN 12Z AND
14Z. HOWEVER THIS WILL BE ISOLATED AND SHORT LIVED. THE CHANCES
ARE SLIM THAT THIS WILL OCCUR AT THE TAF SITES IN CENTRAL AND
EASTERN IL...BUT WILL KEEP A CLOSE EYE ON THIS.

OTHERWISE...VFR CONDITIONS WILL PREVAIL THE NEXT 24 HOURS.
FORECAST SOUNDINGS IN BUFKIT AND THE HRRR CLOUD BASE PROG BOTH
INDICATE THAT A FEW CUMULUS ARE POSSIBLE VERY LATE THIS MORNING
AND DURING THE AFTERNOON...PARTICULARLY IN THE EAST CENTRAL IL.

A SHORTWAVE TROF CURRENTLY IN THE NORTHERN PLAINS IS EXPECTED TO
DIG INTO THE MEAN UPPER TROF POSITION EAST OF THE MS RIVER BY THIS
EVENING. THE ATMOSPHERE WILL BE FAIRLY MOISTURE STARVED...BUT
THERE SHOULD BE ENOUGH LIFT TO PRODUCE AT LEAST A BROKEN AC LAYER
AROUND 10K FT OR SO FROM DUSK THROUGH THE OVERNIGHT HOURS.

MILLER
&&

.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$








AREA FORECAST DISCUSSION

NWS GOODLAND KS

 607 AM MDT SAT AUG 18 2012

.UPDATE...
ISSUED AT 559 AM MDT SAT AUG 18 2012

JUST COMPLETED AN UPDATE. PRECIPITATION IS FURTHER SOUTH AND WEST
THAN MOST GUIDANCE INDICATES. THE LATEST HRRR HAS FINALLY CAUGHT
ONTO THIS AND USED IT FOR THIS UPDATE. HIGHEST CHANCES WILL BE
CONFINED TO THE EAST AND ESPECIALLY THE SOUTH. PRECIPITATION
SHOULD BE DONE BY 18Z. BASED ON LATEST GUIDANCE AND
TRENDS...UPDATED WINDS...DEWPOINTS AND SKY COVER.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION TODAY...LOW
TEMPERATURES TONIGHT...HIGH TEMPERATURES THROUGH THE SHORT TERM...
AND THE NEXT CHANCE OF PRECIPITATION THE BEGINNING OF NEXT WEEK.
SATELLITE SHOWING AN AMPLIFIED/AMPLIFYING PATTERN FROM THE CENTRAL
PACIFIC INTO THE WESTERN ATLANTIC.

THE MODELS INITIALIZED WELL ON THE JET SEGMENT TO OUR NORTH...
ALTHOUGH THE NAM WAS SLIGHTLY WORSE. THE GFS WAS DOING BETTER AT
MID LEVELS. ON THE SURFACE WINDS...THE ECMWF WAS DOING A LITTLE
BETTER THAN THE NAM. ON THE LOW LEVEL THERMAL FIELD...THE GFS AND
ECMWF WERE DOING A LITTLE BETTER THAN THE UKMET AND SREF.

TODAY/TONIGHT...INCOMING UPPER JET AND SHORTWAVE TROUGH/PV ANOMALY
HAVE BEEN CAUSING THUNDERSTORM DEVELOPMENT FOR THE LAST COUPLE OF
HOURS. MODELS ARE HAVING A LITTLE TROUBLE PLACING THE MAIN AXIS.
OVERALL THEY TEND TO PUT IT TOO FAR NORTH AND EAST. MOST IF NOT ALL
OF THE LIFT WILL PUSH THROUGH BY 18Z. CURRENT GRIDS ADJUSTED BY THE
EVENING SHIFT ARE CAPTURING CURRENT STORMS AND TRENDS WELL AND WILL
LEAVE ALONE AT THIS TIME. WILL MAKE FURTHER ENHANCEMENTS AS TIME
PERMITS.

SHOULD SEE FAIRLY RAPIDLY CLEARING BEHIND STORMS. CURRENT CLOUD
COVER IS HOLDING UP MINS AS WELL SO THEY MAY NOT HAVE THAT FAR TO
GO. TENDED TO DO A BLEND OF THE WARMEST/COOLEST GUIDANCE NEAR THE
CONSENSUS OF MOST OF THE GUIDANCE. IF CLOUD COVER LASTS LONGER...
MAXES WILL HAVE TO BE ADJUSTED DOWN.

JET AND LINGERING LIFT HANG AROUND THROUGH THE NIGHT WHICH MAY
CREATE SPOTTY CLOUD COVER. LIGHT AND VARIABLE WINDS AND LOWER
DEWPOINTS WILL ALLOW TEMPERATURES WILL DROP RAPIDLY. LOWERED MINS
BUT DAY SHIFT WILL HAVE TO TAKE A LOOK AT AGAIN. DO NOT HAVE TIME TO
PUT A CLIMATE SECTION IN BUT RECORD LOWS LOOK TO BE THREATENED
TONIGHT OVER THE ENTIRE AREA.

SUNDAY...WEAK JET SEGMENT LOOKS TO STAY OVER THE AREA THROUGH THE
DAY. LEFT FRONT QUADRANT LOOKS TO AFFECT THE WESTERN AREA IN THE
AFTERNOON. HOWEVER LOOKS TO DO NOTHING WITH AN EXTREMELY AIR MASS
OVER THE AREA. SO LOOK TO HAVE PLENTY OF SUN BUT EASTERLY WINDS AS
THE SURFACE RIDGE MOVES THROUGH. FOLLOWED A CON OF
TEMPERATURE GUIDANCE THAT FELL BETWEEN THE TWO EXTREMES.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

SUNDAY NIGHT...ABOVE MENTIONED JET SEGMENT MOVES ACROSS THE AREA
WITH THE RIGHT REAR QUADRANT AFFECTING THE WESTERN HALF TO TWO
THIRDS BY LATE IN THE NIGHT. AGAIN LOOKS LIKE ONLY CLOUDS SINCE
THERE IS A DEEP DRY LAYER AT THE BOTTOM. WINDS ARE SLOW TO COME UP
WITH THE POTENTIAL FOR RATHER COOL MINS ONCE AGAIN.

MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT STARTS THE DAY OVER THE
AREA AND MOVES EAST OF THE AREA BY MID AFTERNOON. A LEFT FRONT
QUADRANT WILL BEGIN TO AFFECT THE AREA BY LATE EVENING AS IT BEGINS
TO MOVE ACROSS THE AREA. THE MAIN MID LEVEL LIFT LOOKS TO MOVE IN
FROM THE NORTHWEST LATE IN THE DAY. ALL THIS LIFT TENDS TO AFFECT
THE SOUTHWEST HALF TO TWO THIRDS OF THE OTHER WHICH IS A SOUTHWARD
SHIFT SINCE YESTERDAY. ANOTHER PROBLEM IS THAT A LOT OF THE MODEL
OUTPUT IS SUFFERING FROM CONVECTIVE FEEDBACK. OVERALL KEPT THE
HIGHER CHANCE POPS FURTHER SOUTHWEST. ONLY MADE A SLIGHT ADJUSTMENT
ON MAXES BUT IF CLOUD COVER IS THICKER THAN EXPECTED WILL NEED TO
ADJUST DOWN.

TUESDAY THROUGH FRIDAY...DUE TO SHORT TERM CONCERNS/INCREASING
THUNDERSTORM COVERAGE WAS NOT ABLE TO SPEED A LOT OF TIME ON THIS
PERIOD. LINGERING CONVECTION WILL BE OVER THE AREA TUESDAY. MODELS
ARE DIFFERING FROM EACH OTHER IN HOW THEY HANDLE THE WESTERN
RIDGING AND HOW SHORTWAVE ENERGY COMES OVER THE TOP. GENERAL IDEA IS
A SERIES OF SHORTWAVE TROUGHS WILL BRING CONTINUED CHANCES FOR
THUNDERSTORMS THROUGH FRIDAY WITH WEDNESDAY AND THURSDAY HAVING THE
GREATEST COVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM MDT SAT AUG 18 2012

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THUNDERSTORMS WILL
STAY TO THE SOUTH AND EAST OF KMCK. CURRENT AREA OF THUNDERSTORMS
WILL AFFECT KGLD FOR A COUPLE MORE HOURS BEFORE ENDING. AS SKIES
CLEAR AND SUBSIDENCE OCCURS BEHIND AREA OF STORMS...WINDS WILL
SHIFT TO THE NORTH AND BECOME GUSTY UNTIL EARLY EVENING BEFORE
BECOMING LIGHT AND VARIABLE.

&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...BULLER
SHORT TERM...BULLER
LONG TERM...BULLER
AVIATION...BULLER







AREA FORECAST DISCUSSION

NWS DODGE CITY KS

 638 AM CDT SAT AUG 18 2012

...UPDATED FOR AVIATION DISCUSSION...

.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 230 AM CDT SAT AUG 18 2012

A LARGE UPPER-LEVEL TROUGH WAS CENTERED OVER THE GREAT LAKES REGION
EARLY THIS MORNING. A SHORTWAVE TROUGH HAS ALREADY ROTATED AROUND
THIS FEATURE AND PUSHED A COLD FRONT INTO THE SOUTHERN PLAINS. THE
WESTERN END OF THIS FRONT PUSHED BACK NORTHWARD INTO NORTHEAST NEW MEXICO
FRIDAY AFTERNOON WHERE SURFACE BASED CONVECTION DEVELOPED. SURFACE
LOW PRESSURE WAS DEVELOPING IN EASTERN COLORADO AS OF 3 AM IN RESPONSE
TO THE NEXT ROBUST SHORTWAVE TROUGH THAT WAS DIVING SOUTHEASTWARD
INTO THE NORTHERN PLAINS ON THE BACK SIDE OF THE GREAT LAKES
LONGWAVE TROUGH.

A LOW LEVEL JET HAD DEVELOPED EARLY THIS MORNING IN RESPONSE TO THE
APPROACHING SHORTWAVE TROUGH. STRONG THETA-E ADVECTION WAS LOCATED
ACROSS FAR WESTERN KANSAS AND WAS PROGRESSING NORTHEASTWARD. NAM
SOUNDINGS VALID FOR 12Z SHOW 1800-2400 J/KG OF ELEVATED CAPE AS FAR
EAST AS CIMARRON AND SCOTT CITY. THUNDERSTORMS WERE ALREADY DEVELOPING
IN THE WARM ADVECTION REGIME ALONG THE EDGE OF THE MID LEVEL CAPPING
INVERSION AS OF 230 AM. ADDITIONAL STORMS WILL DEVELOP AND
PROPAGATE SOUTHEASTWARD WITH THE MID-LEVEL FLOW. THE HRRR AND NAM
INDICATE THAT THE BEST CHANCE OF THUNDERSTORMS WILL BE ALONG AN
AXIS FROM SCOTT CITY TO NESS CITY TO DODGE CITY TO COLDWATER.
PRECIPITATION CHANCES WERE RAISED TO 60-70% IN THIS CORRIDOR.
GIVEN THE ELEVATED SHEAR AND MODERATE ELEVATED CAPE, SEVERE STORMS
ARE POSSIBLE WITH HAIL AS LARGE AS HALF DOLLARS.

THE CONVECTIVE CLUSTER WILL BE SLOW TO EXIT SOUTHERN KANSAS THIS
AFTERNOON SO THAT SOUTHEASTERLY OUTFLOW IN THE WAKE OF THE STORMS
WILL TEND TO KEEP COOL AIR IN PLACE EVEN IF SOME CLEARING OCCURS.
HOWEVER, IF THE MORNING STORM CLUSTER MOVES THROUGH FAST ENOUGH,
THEN DESTABILIZATION COULD LEAD TO RENEWED THUNDERSTORMS BY
MID-AFTERNOON SINCE THE COLD FRONT WILL NOT HAVE PASSED YET. THESE
STORMS COULD BE SURFACE BASED AND COULD ALSO BE SEVERE. HIGH
TEMPERATURES WERE LOWERED SEVERAL DEGREES, ESPECIALLY FROM DODGE
CITY SOUTH AND EAST AND ACTUAL HIGHS WILL PROBABLY OCCUR TOWARD 6-7
PM.

THE COLD FRONT ASSOCIATED WITH THIS UPPER-LEVEL SYSTEM WILL PASS
THROUGH LATE THIS EVENING. CLEARING WILL OCCUR LATE TONIGHT IN
THE WAKE OF THIS SYSTEM WITH SUBSIDING WINDS TOWARD SUNRISE. THE
COOLEST TEMPERATURES OF THE SEASON ARE POSSIBLE, WITH SOME UPPER
40S NOT OUT OF THE QUESTION NEAR SCOTT CITY. SLIGHTLY WARMER MINIMUM
TEMPERATURES IN THE LOWER TO MID 50S ARE EXPECTED AT GARDEN CITY AND
DODGE CITY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 228 AM CDT SAT AUG 18 2012

AN AREA OF HIGH PRESSURE AT THE SURFACE WILL SETTLE INTO CENTRAL
PLAINS ON SUNDAY. SKIES WILL CLEAR AND BASED ON 850MB TEMPERATURES
TRENDS BETWEEN 18Z SUNDAY AND 00Z MONDAY THE PREVIOUS FORECAST STILL
APPEARS ON TRACK WITH HIGHS CLIMBING INTO THE LOW TO MID 80S.

A CLEAR AND COOL NIGHT CAN BE EXPECTED SUNDAY NIGHT AS THIS SURFACE
HIGH SLOWLY CROSSES WESTERN AND CENTRAL KANSAS. BASED ON WHERE THE
LIGHTEST WINDS WILL BE BETWEEN 09Z AND 12Z SUNDAY  AM LEANING
TOWARDS UNDERCUTTING THE COOLEST GUIDANCE WHILE STAYED CLOSE TO THE
MAV/MET ELSEWHERE.

ON MONDAY THE NEXT UPPER LEVEL DISTURBANCE WILL BEGIN TO CROSS THE
CENTRAL ROCKIES. THE GFS, NAM, AND ECMWF REMAIN IN DECENT AGREEMENT
WITH THIS NEXT SYSTEM EXITING THE ROCKIES AND CROSSING INTO THE
CENTRAL PLAINS LATE MONDAY NIGHT AND TUESDAY. AS THIS SYSTEM
CROSSING INTO THE PLAINS...SCATTERED SHOWERS AND THUNDERSTORMS ARE
EXPECTED TO DEVELOP WITH THE BETTER CHANCES FOR WIDESPREAD
PRECIPITATION BEING LATE MONDAY NIGHT/EARLY TUESDAY BASED ON THE
UPPER LEVEL JET DYNAMICS, 850-700MB MOISTURE AND IMPROVING
FRONTOGENESIS.

ONCE THIS SYSTEM EXITS THE CENTRAL PLAINS AND MOVES TOWARDS THE
LOWER MISSISSIPPI VALLEY THE MID LEVEL FLOW WILL BACK AND BECOME
MORE PERPENDICULAR TO THE ROCKIES. THIS ENHANCED DOWNSLOPE FLOW
SUGGESTS A WARMING TREND MID WEEK AS A TROUGH OF LOW PRESSURE AT THE
SURFACE BEGINS TO DEVELOP ALONG THE LEE OF THE ROCKIES.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 632 AM CDT SAT AUG 18 2012

ANOTHER CLUSTER OF THUNDERSTORMS WILL AFFECT GCK/DDC BETWEEN 1230
AND 15 UTC. SOME HEAVY RAIN, WIND GUSTS AS HIGH AS 45 MPH AND
SMALL HAIL ARE POSSIBLE CLOSE TO THESE TERMINALS. OUTSIDE OF THE
STORMS, VFR CONDITIONS WILL PREVAIL. ISOLATED THUNDERSTORMS COULD ALSO
AFFECT THE HYS TERMINAL THROUGH 16 UTC. A COLD FRONT WILL PASS
THROUGH THE TERMINALS BY 03Z, WITH A WIND SHIFT TO THE NORTH.

&&

.PRELIMINARY POINT TEMPS/POPS...
DDC  79  52  82  54 /  90  20  10   0
GCK  83  51  82  54 /  70  10  10  10
EHA  84  61  83  56 /  30  20  10  10
LBL  80  58  84  55 /  40  20  10  10
HYS  83  49  82  53 /  50  20  10   0
P28  81  59  84  55 /  60  30  10   0

&&

.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...FINCH







AREA FORECAST DISCUSSION

NWS CARIBOU ME

 1011 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WILL STALL ALONG THE MAINE COAST TODAY AND TONIGHT.
LOW PRESSURE WILL APPROACH FROM THE SOUTH LATER SUNDAY AND MONDAY.&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...HAVE ADJUSTED POP AND WEATHER GRIDS TO BETTER FIT CURRENT
RADAR IMAGERY.

A COLD FRONT IS EXPECTED TO BECOME STATIONARY ALONG THE DOWNEAST
COAST TODAY. WITH UPPER LOW NEAR JAMES BAY AND 500MB FLOW PARALLEL
TO THE FRONT THIS SCENARIO LOOKS MOST REASONABLE. AT THE SAME TIME
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE WEST LATER TODAY AND
TONIGHT. FOR POPS HAVE BEEN USING HRRR THEN MERGING IT WITH BLEND
OF THE NAM12...GFS40...SREF AND ECMWF. FOR QPF HAVE USED THE SAME
BLEND BUT WILL EXCHANGE NAM12 FOR NAM80. FOR WIND HAVE BLENDED
NAM12 AND GMOS AND WILL USE ONLY GMOS LATE TONIGHT. FOR
TEMPERATURE AND DEW POINT WILL USE GMOS WITH SOME MINOR
ADJUSTMENTS TO MAXIMUM TEMPERATURE.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MAIN CHALLENGE WILL BE STALLED FRONTAL BOUNDARY ALONG THE COAST ON
SUNDAY AND WEAK LOW PRES WAVE MOVING UP ALONG THE FRONT.

DECIDED TO FOLLOW A BLEND OF THE ECMWF AND CANADIAN GLOBAL THIS
FCST CYCLE SHOWING AN AREA OF RAIN AFFECTING MAINLY THE COAST AND
OVER THE GULF OF MAINE WATERS FOR SUNDAY. THESE 2 NUMERICAL MODELS
WERE CONSISTENT W/THEIR PREVIOUS RUNS OF SHOWING THIS WAVE MOVING
UP ALONG THE FRONT. THE BOUNDARY WILL SERVE AS A CONVERGENCE AXIS
AND W/THE LOW, ENOUGH FORCING WILL BE THERE FOR A PERIOD OF RAIN
IN THE AFOREMENTIONED AREAS. THEREFORE, INCREASED THE RAIN PERCENTAGES
TO 50-60% ACROSS THE COAST AND OVER THE WATERS UP THROUGH 18Z AND
THEN DRY THINGS OUT AS THE FRONT SLIDES FURTHER SOUTH AND
EAST.THIS WILL ALSO HOLD DOWN TEMPERATURES OVER THE DOWNEAST AND
THE COAST(LOW/MID 70S). FURTHER NORTH AND WEST, DRIER CONDITIONS
AND HENCE WARMER TEMPERATURES(MID-UPPER 70S). QPF AMOUNTS WERE
ADJUSTED USING THE ECMWF AND CANADIAN GLOBAL W/AREAL ADJUSTMENTS.
THEREFORE, NOT EXPECTING MORE THAN .10" OF RAINFALL ALONG THE
IMMEDIATE COAST.

HIGH PRES IS SET TO RIDGE IN ACROSS THE CWA FROM THE SW SUNDAY
NIGHT INTO MONDAY. THIS SHOULD ALLOW FOR DRY CONDITIONS AND WARMER
TEMPERATURES. BROAD SWLY FLOW ALOFT WILL ALLOW FOR SOME CUMULUS TO
DEVELOP BY LATE MORNING. REMOVED THE MENTION OF RAIN SHOWERS FOR
MONDAY AND RAISED MAXES FROM THE PREVIOUS FORECAST UP A CATEGORY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BACKED AWAY FROM GMOS THROUGH WEDNESDAY AND BASICALLY STAYED
CLOSER TO THE ECMWF. THE ECMWF HAS BEEN CONSISTENT W/THE SYNOPTIC
PATTERN OF A  BROAD SW FLOW ALOFT W/CLOSED LOWER OVER HUDSON`S BAY.
THIS WILL ALLOW FOR A WAVE OF LOW PRES TO DEVELOP ON THAT STALLED
FRONTAL BOUNDARY JUST OFF THE MAINE COAST TO MOVE UP ALONG THE
FRONT ON TUESDAY. THE GFS APPEARED TO BE TOO STRONG AND AGGRESSIVE
W/THE LOW WHILE THE ECMWF AND CANADIAN GLOBAL KEEP THE LOW FURTHER
S AND E AND BOTH ARE NOT AS STRONG W/THE WAVE AND HAVE A SECOND
FRONT APPROACHING FROM CANADA BY TUESDAY AFTERNOON. DECIDED TO CUT
BACK ON PRECIP CHANCES TUESDAY W/THE LOW OFF THE COAST AND LEAN
W/A 20-30% CHANCE FOR SHOWERS IN THE AFTERNOON DUE TO THE COLD
FRONT MOVING IN FROM THE WEST. BOTH THE CANADIAN GLOBAL AND ECMWF
SUPPORT SOME SHOWER AS UPPER LEVEL SUPPORT IS THERE. TWEAKED
TEMPERATURES FOR TUESDAY TO BRING THEM UP A CATEGORY INTO THE
MID AND UPPER 70S. HIGH PRES AT THE SFC IS SHOWN TO MOVE ACROSS
THE REGION ON WEDNESDAY AND THE FRONT SLIDES TO THE EAST. THIS
WILL ALLOW FOR A DRY AND COMFORTABLE DAY. UPPER FLOW APPEARS TO
SHIFT A BIT TO A MORE WESTERLY COMPONENT ALLOWING FOR A DRIER SETUP.
OVERNIGHT TEMPERATURES MONDAY NIGHT AND AGAIN TUESDAY NIGHT LOOKED
TO NEED ADJUSTMENTS UPWARD USING A NAM12/GMOS BLEND. BROAD SW FLOW
ALOFT SEEMS TO FAVOR A WARM SCENARIO. DAY CREW CAN ASSESS THIS
FURTHER W/NEWER MODEL GUIDANCE.

THE UPPER TROF LOOKS LIKE IT WILL SHARPEN AGAIN BY LATE WEEK W/S
FRONTAL BOUNDARY APPROACHING. THERE IS THE POTENTIAL FOR SHOWERS
AND POSSIBLE TSTMS ON THURSDAY AND AGAIN FRIDAY AND THE FRONT WILL
BE SLOW TO MOVE ACROSS THE REGION. ATTM, STAYED CLOSER TO GMOS
W/30% POPS AND STAYED CLOSER TO THE TEMPERATURES SHOWING NEAR
NORMAL READINGS FOR LATE AUGUST.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: EXPECT VFR CONDITIONS TODAY WITH IFR CONDITIONS LATER
TONIGHT MOSTLY DUE TO CEILINGS.

SHORT TERM: POSSIBLE IFR/MVFR FOR THE COAST ON SUNDAY AND THEN
CONDITIONS IMPROVE TO VFR. IT LOOKS LIKE VFR FOR THE NORTHERN
TERMINALS THROUGH MONDAY. THERE DOES APPEAR TO BE SOME POTENTIAL
FOR MVFR AND POSSIBLY IFR CONDITIONS LATER MONDAY NIGHT INTO
TUESDAY MORNING W/A LIGHT ESE FLOW SETTING UP.

&&

.MARINE...
NEAR TERM: FOR WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND
GFS40 AND ADJUSTED BLEND DOWN 20 PERCENT DUE TO EXPECTED BOUNDARY
CONDITIONS. WILL USE NAM/SWAN TO INITIALIZE WAVE GRIDS. WILL
ADJUST WAVE MODEL DOWN 1 FOOT. PRIMARY WAVE GROUP IS WEAK
SOUTHERLY FETCH AROUND PERIPHERY OF HIGH OFF-SHORE. WAVE MODELS ARE
TOO HIGH WITH THIS WAVE GROUP. WNA SPECTRAL CONTINUES TO SHOW
BACKGROUND SOUTHEAST SWELL AT AROUND 1 FOOT. VERY LONG PERIOD
SWELL FROM ATLANTIC TROPICAL SYSTEMS MAY SHOW UP BUT NOT UNTIL
NEXT WEEK. WILL KEEP FOG ACROSS COASTAL WATERS WITH FRONT STALLED
ALONG COAST.


SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE NAM12 AND
GFS40 WAS USED FOR THE WINDS INTO MONDAY WHICH SHOWS SUSTAINED
WINDS AT 10-15 KTS. AN ESE SWELL LOOKS POSSIBLE BY MONDAY AND
COULD CONTINUE THROUGH THE WEEK W/A LONG PERIOD. AS MENTIONED
IN THE NEAR TERM, WANAVE RUNNING TOO HIGH AND THEREFORE STAYED
W/THE CURRENT WAVE HEIGHTS OF 2-3 FT THROUGH THE PERIOD.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...MIGNONE/RUNYAN
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE/RUNYAN
MARINE...MIGNONE/RUNYAN/HEWITT







AREA FORECAST DISCUSSION

NWS CARIBOU ME

 713 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WILL STALL ALONG THE MAINE COAST TODAY AND TONIGHT.
LOW PRESSURE WILL APPROACH FROM THE SOUTH LATER SUNDAY AND MONDAY.

&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...HAVE ADJUSTED POP AND WEATHER GRIDS TO BETTER FIT CURRENT
RADAR. HAVE ALSO ADJUSTED FOG AREAS IN COASTAL ZONES.

A COLD FRONT IS EXPECTED TO BECOME STATIONARY ALONG THE DOWNEAST
COAST TODAY. WITH UPPER LOW NEAR JAMES BAY AND 500MB FLOW PARALLEL
TO THE FRONT THIS SCENARIO LOOKS MOST REASONABLE. AT THE SAME TIME
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE WEST LATER TODAY AND
TONIGHT. FOR POPS HAVE BEEN USING HRRR THEN MERGING IT WITH BLEND
OF THE NAM12...GFS40...SREF AND ECMWF. FOR QPF HAVE USED THE SAME
BLEND BUT WILL EXCHANGE NAM12 FOR NAM80. FOR WIND HAVE BLENDED
NAM12 AND GMOS AND WILL USE ONLY GMOS LATE TONIGHT. FOR
TEMPERATURE AND DEW POINT WILL USE GMOS WITH SOME MINOR
ADJUSTMENTS TO MAXIMUM TEMPERATURE.

&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MAIN CHALLENGE WILL BE STALLED FRONTAL BOUNDARY ALONG THE COAST ON
SUNDAY AND WEAK LOW PRES WAVE MOVING UP ALONG THE FRONT.

DECIDED TO FOLLOW A BLEND OF THE ECMWF AND CANADIAN GLOBAL THIS
FCST CYCLE SHOWING AN AREA OF RAIN AFFECTING MAINLY THE COAST AND
OVER THE GULF OF MAINE WATERS FOR SUNDAY. THESE 2 NUMERICAL MODELS
WERE CONSISTENT W/THEIR PREVIOUS RUNS OF SHOWING THIS WAVE MOVING
UP ALONG THE FRONT. THE BOUNDARY WILL SERVE AS A CONVERGENCE AXIS
AND W/THE LOW, ENOUGH FORCING WILL BE THERE FOR A PERIOD OF RAIN
IN THE AFOREMENTIONED AREAS. THEREFORE, INCREASED THE RAIN PERCENTAGES
TO 50-60% ACROSS THE COAST AND OVER THE WATERS UP THROUGH 18Z AND
THEN DRY THINGS OUT AS THE FRONT SLIDES FURTHER SOUTH AND
EAST.THIS WILL ALSO HOLD DOWN TEMPERATURES OVER THE DOWNEAST AND
THE COAST(LOW/MID 70S). FURTHER NORTH AND WEST, DRIER CONDITIONS
AND HENCE WARMER TEMPERATURES(MID-UPPER 70S). QPF AMOUNTS WERE
ADJUSTED USING THE ECMWF AND CANADIAN GLOBAL W/AREAL ADJUSTMENTS.
THEREFORE, NOT EXPECTING MORE THAN .10" OF RAINFALL ALONG THE
IMMEDIATE COAST.

HIGH PRES IS SET TO RIDGE IN ACROSS THE CWA FROM THE SW SUNDAY
NIGHT INTO MONDAY. THIS SHOULD ALLOW FOR DRY CONDITIONS AND WARMER
TEMPERATURES. BROAD SWLY FLOW ALOFT WILL ALLOW FOR SOME CUMULUS TO
DEVELOP BY LATE MORNING. REMOVED THE MENTION OF RAIN SHOWERS FOR
MONDAY AND RAISED MAXES FROM THE PREVIOUS FORECAST UP A CATEGORY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BACKED AWAY FROM GMOS THROUGH WEDNESDAY AND BASICALLY STAYED
CLOSER TO THE ECMWF. THE ECMWF HAS BEEN CONSISTENT W/THE SYNOPTIC
PATTERN OF A  BROAD SW FLOW ALOFT W/CLOSED LOWER OVER HUDSON`S BAY.
THIS WILL ALLOW FOR A WAVE OF LOW PRES TO DEVELOP ON THAT STALLED
FRONTAL BOUNDARY JUST OFF THE MAINE COAST TO MOVE UP ALONG THE
FRONT ON TUESDAY. THE GFS APPEARED TO BE TOO STRONG AND AGGRESSIVE
W/THE LOW WHILE THE ECMWF AND CANADIAN GLOBAL KEEP THE LOW FURTHER
S AND E AND BOTH ARE NOT AS STRONG W/THE WAVE AND HAVE A SECOND
FRONT APPROACHING FROM CANADA BY TUESDAY AFTERNOON. DECIDED TO CUT
BACK ON PRECIP CHANCES TUESDAY W/THE LOW OFF THE COAST AND LEAN
W/A 20-30% CHANCE FOR SHOWERS IN THE AFTERNOON DUE TO THE COLD
FRONT MOVING IN FROM THE WEST. BOTH THE CANADIAN GLOBAL AND ECMWF
SUPPORT SOME SHOWER AS UPPER LEVEL SUPPORT IS THERE. TWEAKED
TEMPERATURES FOR TUESDAY TO BRING THEM UP A CATEGORY INTO THE
MID AND UPPER 70S. HIGH PRES AT THE SFC IS SHOWN TO MOVE ACROSS
THE REGION ON WEDNESDAY AND THE FRONT SLIDES TO THE EAST. THIS
WILL ALLOW FOR A DRY AND COMFORTABLE DAY. UPPER FLOW APPEARS TO
SHIFT A BIT TO A MORE WESTERLY COMPONENT ALLOWING FOR A DRIER SETUP.
OVERNIGHT TEMPERATURES MONDAY NIGHT AND AGAIN TUESDAY NIGHT LOOKED
TO NEED ADJUSTMENTS UPWARD USING A NAM12/GMOS BLEND. BROAD SW FLOW
ALOFT SEEMS TO FAVOR A WARM SCENARIO. DAYCREW CAN ASSESS THIS
FURTHER W/NEWER MODEL GUIDANCE.

THE UPPER TROF LOOKS LIKE IT WILL SHARPEN AGAIN BY LATE WEEK W/S
FRONTAL BOUNDARY APPROACHING. THERE IS THE POTENTIAL FOR SHOWERS
AND POSSIBLE TSTMS ON THURSDAY AND AGAIN FRIDAY AND THE FRONT WILL
BE SLOW TO MOVE ACROSS THE REGION. ATTM, STAYED CLOSER TO GMOS
W/30% POPS AND STAYED CLOSER TO THE TEMPERATURES SHOWING NEAR
NORMAL READINGS FOR LATE AUGUST.

&&

.AVIATION /11Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: EXPECT VFR CONDITIONS TODAY WITH IFR CONDITIONS LATER
TONIGHT MOSTLY DUE TO CEILINGS.

SHORT TERM: POSSIBLE IFR/MVFR FOR THE COAST ON SUNDAY AND THEN
CONDITIONS IMPROVE TO VFR. IT LOOKS LIKE VFR FOR THE NORTHERN
TERMINALS THROUGH MONDAY. THERE DOES APPEAR TO BE SOME POTENTIAL
FOR MVFR AND POSSIBLY IFR CONDITIONS LATER MONDAY NIGHT INTO
TUESDAY MORNING W/A LIGHT ESE FLOW SETTING UP.

&&

.MARINE...
NEAR TERM: FOR WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND
GFS40 AND ADJUSTED BLEND DOWN 20 PERCENT DUE TO EXPECTED BOUNDARY
CONDITIONS. WILL USE NAM/SWAN TO INITIALIZE WAVE GRIDS. WILL
ADJUST WAVE MODEL DOWN 1 FOOT. PRIMARY WAVE GROUP IS WEAK
SOUTHERLY FETCH AROUND PERIPHERY OF HIGH OFF-SHORE. WAVE MODELS ARE
TOO HIGH WITH THIS WAVE GROUP. WNA SPECTRAL CONTINUES TO SHOW
BACKGROUND SOUTHEAST SWELL AT AROUND 1 FOOT. VERY LONG PERIOD
SWELL FROM ATLANTIC TROPICAL SYSTEMS MAY SHOW UP BUT NOT UNTIL
NEXT WEEK. WILL KEEP FOG ACROSS COASTAL WATERS WITH FRONT STALLED
ALONG COAST.


SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE NAM12 AND
GFS40 WAS USED FOR THE WINDS INTO MONDAY WHICH SHOWS SUSTAINED
WINDS AT 10-15 KTS. AN ESE SWELL LOOKS POSSIBLE BY MONDAY AND
COULD CONTINUE THROUGH THE WEEK W/A LONG PERIOD. AS MENTIONED
IN THE NEAR TERM, WANAVE RUNNING TOO HIGH AND THEREFORE STAYED
W/THE CURRENT WAVE HEIGHTS OF 2-3 FT THROUGH THE PERIOD.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...MIGNONE
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE
MARINE...MIGNONE/HEWITT







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 1102 AM EDT SAT AUG 18 2012

.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND COOLER WEATHER TO CONTINUE
THROUGH TONIGHT. COOLER WEATHER WILL CONTINUE ON SUNDAY, ALTHOUGH
AN UPPER LEVEL DISTURBANCE MAY BRING A FEW ISOLATED SHOWERS TO THE
AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO REMOVE
MORNING FOG WORDING AND TO INCREASE CLOUD COVERAGE TODAY.

THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IS AT THE
BASE OF WEAK CYCLONIC MID-LEVEL FLOW THAT IS ON THE DISTANT
SOUTHERN PERIPHERY OF A VORTEX CENTERED OVER THE HUDSON BAY. DRY
AIR IS IN PLACE IN THE 750-400MB LAYER. THIS COUPLED WITH SURFACE
HIGH PRESSURE EXTENDING FROM THE MIDWEST INTO THE OHIO VALLEY HAS
YIELDED A DRY DAY ACROSS THE AREA.

THE SURFACE HIGH WILL SLOWLY SLIDE EASTWARD TODAY AND TONIGHT,
ALLOWING FOR DRY WEATHER TO CONTINUE. TEMP DIFFERENTIAL BTW 850MB
AND A WARMER LAKE ERIE WITH AN INITIAL NORTHWESTERLY FLOW WILL
ALLOW FOR DIURNAL CUMULUS TO DEVELOP ACROSS MOST OF THE AREA WITH
PARTLY CLOUDY SKIES TODAY. DIURNAL CUMULUS THAT DEVELOPS WILL
QUICKLY DIMINISH AFTER SUNSET. SOME THIN CIRRUS WILL ADVECT ACROSS
THE AREA TONIGHT. WITH NEAR CALM WINDS, RADIATIONAL COOLING WILL
OCCUR TONIGHT. LOWS ARE SLIGHTLY COOLER THAN A MAV/MET BLEND,
RANGING FROM THE UPPER 40S ACROSS THE I-80 CORRIDOR AND EASTERN
RIDGES TO THE LOWER 50S ELSEWHERE.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE UPPER OHIO VALLEY IS FORECAST TO REMAIN UNDER THE INFLUENCE OF
A JAMES BAY TO GULF COAST TROUGH THROUGH THE SHORT TERM PERIOD. ALTHOUGH
THE BOUNDARY LAYER MOISTURE FORECAST LOOKS RATHER LIMITED...STEEPENING
LAPSE RATES WITH A SHORTWAVE IN THE UPPER FLOW MAY SUPPORT SOME
ISOLATED TO SCATTERED SHOWERS ON SUNDAY. SLIGHT CHANCE POPS HAVE
THUS BEEN INTRODUCED...AND CONTINUED THROUGH MONDAY GIVEN THE
PRESENCE OF THE TROUGH AXIS PROJECTED TO LINGER OVER THE GREAT
LAKES AND OHIO VALLEY REGION. BY TUESDAY...THAT AXIS IS FORECAST
FAR ENOUGH EAST FOR A DRY FORECAST AS SURFACE HIGH PRES BUILD OVER
THE OHIO VALLEY. TEMPS UNDER THIS PATTERN ARE PROJECTED ABOUT 5
DEGREES UNDER THE AVERAGES USING TWEAKED SREF MEANS BLENDED WITH
THE LATEST MOS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
WEAK SURFACE HIGH PRESSURE THAT IS FORECAST TO REMAIN OVER THE REGION
THROUGHOUT THE WEEK WILL SUPPORT SEASONAL TEMPERATURES AND
GENERALLY DRY CONDITIONS.

&&

.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
EXPECT REMAINING MVFR STRATUS CLOUD BANK NEAR THE MOUNTAINS AND
AFFECTING TAF SITES SUCH AS KLBE AND KMGW TO DISSIPATE BEFORE 16Z.
AFTER THAT, NONSTOP VFR AS GENERALLY NO MORE THAN SCATTERED DAYTIME
CUMULUS EXPECTED TO DEVELOP THIS AFTERNOON.

SURFACE WINDS WILL BE MAINLY FROM THE NORTHWEST INCREASING TO
MORE THAN 8 KTS BY AFTERNOON.

.OUTLOOK/ SUNDAY THROUGH WEDNESDAY/...
VFR.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS BALTIMORE MD/WASHINGTON DC

 1031 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WHICH MOVED ACROSS THE AREA LAST NIGHT WILL STALL OUT
ACROSS SOUTHEAST VIRGINIA TODAY. THE BOUNDARY WILL RETURN NORTH
AS A WARM FRONT SUNDAY. A WAVE OF LOW PRESSURE MAY DEVELOP ALONG
THE BOUNDARY...IMPACTING THE WATERS SUNDAY NIGHT INTO MONDAY. HIGH
PRESSURE WILL SLOWLY BUILD TOWARD THE WATERS DURING THE MIDDLE
PORTION OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT HAS PUSHED SOUTHEAST OF THE AREA THIS MORNING...AND IS
LIKELY TO STALL OUT ACROSS EXTREME SOUTHEAST VIRGINIA OR THE
NORTHEAST NORTH CAROLINA COAST THIS AFTERNOON.

NORTH/NORTHWEST WINDS HAVE BROUGHT SOME DRIER AIR BOTH AT THE
SURFACE AND ALOFT ACROSS THE AREA. BUT WITH SOME COOLING ALOFT
ATOP THE WARM GROUND...EXPECT AT LEAST SCATTERED CUMULUS TO DOT
THE SKY THIS AFTERNOON.

MORE CLOUDS MAY BE FOUND ACROSS SOUTHERN MARYLAND AND THE LOWER
CHESAPEAKE BAY AREA CLOSER TO THE FRONT AND ALSO WITHIN THE UPPER
JET FLOW. THIS IS ALSO AN AREA WHERE ISOLATED SHOWERS MAY DEVELOP THIS
AFTERNOON PER THE WRF-ARW. HRRR IMPLIES THERE MAY BE SHOWERS
FURTHER NORTH AND WEST...BUT GIVEN DRYING AND WEAK FORCING HAVE
KEPT REST OF THE CWA DRY. MAXIMA ARE FORECAST TO BE SLIGHTLY BELOW
CLIMO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
LIGHT NELY/ELY FLOW DEVELOPS WITH ISOLATED CHANCE FOR SHOWERS
EXPANDING WEST TO THE BLUE RIDGE. PLENTY OF CLOUDS WITH MIN TEMPS
MID TO UPR 50S PIEDMONT AND WEST...LOW TO MID 60S I-95 AND EAST.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
THIS XTND FCST IS "A STORY OF THE DIFFERENCES IN THE MDL POSNS OF
LAST NGT AND TNGT." LAST NGT NAM HAD A CLOSED SFC LOW OVR THE MID
ATLC SUNDAY WHILE THE GFS DVLPD IT OFFSHORE. TNGT THE CHG IS
FOCUSED ON SUN NGT/MON. GFS HAS CHGD TO HV THE SFC LOW DVLP UNDER
THE UPR TROF - FORMING IN THE TN VLLY SUN NGT AND MOVG OVR THE
DELMARVA MON EVE. THE NAM FORMS THE LOW OFF THE CST...SO
ESSENTIALLY A "180" FM THE PRVS NGT. THIS IN TURN GIVES CAT POPS
TO THE ENTIRE CWA FOR MON FM THE GFS...WHILE THE NAM RANGES FM LKLY
AT BALT TO NOTHING AT SHD.

I MUST SAY - LAST NGT I WAS VERY SUSPICIOUS WHEN THE NAM WENT SO
AGGRESSIVE W/ POPS...BUT AM LESS SO W/ THE NEW GFS APPROACH. LAST
YR I DID A STUDY ON GFS PERFORMANCE DURG THE SUMMER MONTHS AT THE
3 MAJOR AIRPORTS. FM 2009-11...DURG THE SUMMER...WHEN THE GFS
FCSTD 80 POP IN PD 5 - IN THIS CASE THAT`D BE MON...MEASURABLE
PCPN OCCURRED 14 OUT OF 14 TIMES. HIGH POPS CAN BE HARD TO JUSTIFY
IN SUMMER DUE TO THE "HIT OR MISS" NATURE OF CNVCTN...BUT IT`S
HARD TO ARGUE W/ THOSE NUMBERS...ESPECIALLY WHEN WE`RE NOT TALKING
ABT A CD FNT APRCHG FM THE NW.

ECM IS COMING IN AS I WRITE AT 315 AM. ITS SFC LOW IS NOT AS
TIGHT AS THE GFS DEPICTION BUT IT TOO HAS THE INCRSD RH IN THE E.
21Z SREF ALSO HAD A 50% CHC OF .05" FOR MON IN THE E.

SO FOR NOW HV INCRSD THE POPS FOR MON E OF THE MTNS FM CHC TO
LKLY...W/ HIGHEST NUMBERS ALONG THE BAY. IF THE SYNOPTIC PATTERN
PLAYS OUT LK I`M BEGINING TO THINK IT WL PCPN MOST LKLY WL BE RW
W/ EMBEDDED T PSBL. AM NOT THINKING A SVR OUTBRK GIVEN ERLY FLOW
AND DEEP CLD CVR. THE PCPN WOULD MOST LKLY BE EXITING THE AREA DURG MON
AFTN...SO FLDG NOT A CONCERN.

AFTR MON HIGH PRES LOOKS TO BLD IN FOR TUE-FRI. TEMPWISE THE WK
AHD SHOULD BE QUITE PLSNT W/ DAYS W/ HIGHS IN THE LM80S AND NGTS
RANGING FM THE M50S IN THE MTNS TO L70S ON THE CHES BAY. FM I-81
TO I-95 WL DROP INTO THE 60S.

&&

.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
VFR TODAY WITH FRONT STALLING OUT OVER FAR SOUTHEAST VIRGINIA.
EXPECT SHOWERS TO REMAIN SOUTHEAST OF THE TERMINALS. N/NW WINDS
MAY BE 10 TO 15 KT AT TIMES DURING THE AFTERNOON.

CIGS MAY DROP INTO MVFR CAT SUN NGT AND MON AS LOW PRES TRACKS
ACROSS THE ERN PORTION OF THE FCST AREA. ISOLD TSTMS WOULD BE
PSBL. HIGH PRES TO BUILD IN TUE THRU THU.

&&

.MARINE...
NORTHERLY WINDS HAVE BEEN DIMINISHING OVER THE LAST COUPLE OF
HOURS AND THE LATEST COVM2 OB DROPPED TO 17 KT. TREND SHOULD
CONTINUE AND THUS SCA WILL BE CANCELLED. EXPECT 10 TO 15 KT FOR
THE REST OF THE AFTERNOON.

THERE IS SOME DIFFERENCE IN THE MDLS REGARDING THE DVLPMNT OF A
LOW PRES AREA TO OUR SW SUN MOVG INTO THE WATERS MON. IF THIS DOES
COMES TRUE MON MAY BE WETTER THAN PRVSLY THOT. THERE MAY ALSO BE A
PD OF SCA-LVL WINDS.

HIGH PRES LOOKS TO MOVE INTO THE MID ATLC TUE-FRI.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
BPP/BAJ/WOODY!








AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 739 AM EDT SAT AUG 18 2012

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 500 AM EDT SAT AUG 18 2012

WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A DEEP TROF DOMINATING
ROUGHLY THE E HALF OF THE CONUS. TROF IS ANCHORED BY A MID/UPPER
LEVEL LOW CENTERED OVER JAMES BAY. A NUMBER OF SHORTWAVES ARE
ROTATING THRU THE TROF THOUGH NONE ARE ESPECIALLY STRONG. MOST
NOTABLE WAVES ARE TRACKING SE THRU MN AND THE DAKOTAS...BUT THE WAVE
OF INTEREST FOR TODAY IS DROPPING THRU NRN ONTARIO. CANADIAN RADARS
HAVE BEEN SHOWING SCT SHRA STREAKING SE ACROSS NE LAKE SUPERIOR WITH
MAIN BAND OF SHRA SINKING S TOWARD THE MN ARROWHEAD AND ISLE ROYALE.

FCST THINKING FOR TODAY HASN`T CHANGED MUCH FROM PREVIOUS SHIFTS.
SHORTWAVE WILL DROP INTO THE UPPER LAKES TODAY WITH ASSOCIATED SFC
COLD FRONT MOVING THRU THE AREA. WITH CYCLONIC FLOW...APPROACHING
SHORTWAVE/COLD POCKET ALOFT...COLD FRONT ARRIVING DURING HEATING
CYCLE AND MLCAPE INCREASING TO BTWN 200 AND 500J/KG...IT STILL LOOKS
LIKE A GOOD SETUP FOR SCT/NMRS SHRA TODAY...ESPECIALLY SINCE SHRA
ARE ALREADY OCCURRING UPSTREAM DURING THE PERIOD OF THE DIURNAL MIN.
TIMING OF COLD FRONT INTO THE SRN FCST AREA DURING THE LATER AFTN
SHOULD FAVOR THAT AREA FOR THE GREATEST SHRA COVERAGE. CAN`T RULE
OUT SOME THUNDER AS WELL...PARTICULARLY SINCE A FEW LIGHTNING
STRIKES WERE DETECTED UPSTREAM IN ONTARIO LAST EVENING. AGAIN...THE
SRN PORTIONS OF THE FCST AREA WILL BE FAVORED. LOW FREEZING/WET BULB
ZERO LEVELS SUPPORT POTENTIAL OF SMALL HAIL WITH ANY STORMS...
ESPECIALLY IF THERE IS ENOUGH HEATING THRU THE MORNING HRS TO HELP
BUILD INSTABILITY A LITTLE HIGHER THAN CURRENTLY PROGGED.

ALTHOUGH WAVES ARE SUBSIDING ON LAKE SUPERIOR AFTER A COUPLE OF
ROUGH DAYS...WAVES ARE STILL HIGH ENOUGH TO RESULT IN A MODERATE
RISK OF RIP CURRENTS ALONG THE BEACHES OF ALGER COUNTY THRU EARLY
AFTERNOON.

SIGNIFICANT COLUMN DRYING OCCURS TONIGHT BEHIND SHORTWAVE...MOST
NOTABLY WITH THE GFS. THIS WILL WORK TO MINIMIZE LAKE EFFECT -SHRA
POTENTIAL AS 850MB TEMPS BECOME MARGINALLY LOW ENOUGH OVER THE ERN
LAKE (4C) BY 12Z SUN. GIVEN THE DRYING...WILL NOT INCLUDE ANY PCPN
MENTION OTHER THAN LINGERING -SHRA SCNTRL. TO THE W...DEGREE OF
DRYING AND WARMER 850MB TEMPS SUGGESTS LITTLE/NO LAKE CLOUD...AND
WITH WINDS DIMINISHING UNDER DRYING COLUMN (PRECIPITABLE WATER
40-55CT OF NORMAL)...IT SHOULD BE A CHILLY NIGHT OVER THE INTERIOR
W. A FEW UPPER 30S ARE POSSIBLE IN THE TRADITIONAL COLD SPOTS.
TYPICAL FOR COOL NIGHTS AT THIS TIME OF YEAR...SOME GROUND FOG WILL
ALSO BE POSSIBLE IN LOW-LYING AREAS AROUND
RIVERS/STREAMS/LAKES/SWAMPS OVER THE INTERIOR W HALF...ESPECIALLY
WHERE RAINFALL OCCURS TODAY.

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 500 AM EDT SAT AUG 18 2012

SUN...MODELS HINT AT A WEAK DISTURBANCE ROTATING DOWN FM CLOSED LOW
NEAR JAMES BAY...BUT VERY DRY LOW LVLS AND WEAK DYNAMIC FORCING
SHOULD ALLOW FOR MAINLY DRY CONDITIONS ACROSS CWA. FCST H85 TEMPS FM
6C OVER THE E TO 8C OVER THE W IN LIGHT NRLY FLOW WILL SUPPORT HI
TEMPS FM MID 60S NEAR LAKE SUPERIOR TO LOWER 70S SCNTRL.

SUN NIGHT...ALTHOUGH THERE MAY BE MORE SCT MID CLDS ASSOCIATED WITH
ANOTHER DISTURBANCE APPROACHING IN NW FLOW ALF...LACK OF SIGNIFICANT
DYNAMIC SUPPORT AND OVERALL DRYNESS OF THE LLVLS SHOULD PREVENT ANY
PCPN. WITH LGT WINDS ESPECIALLY IN THE EVENING CLOSER TO SFC HI PRES
SINKING TOWARD THE LOWER GREAT LAKES...TEMPS COULD FALL INTO THE MID
TO UPPER 30S OVER SOME WRN INTERIOR COLD SPOTS WITH LOWER 40S
ELSEWHERE INLAND. DID NOT MENTION ANY PATCHY FROST FOR NOW BUT THIS
COULD BE A POSSIBILITY IF MODELS KEEP SFC RDG OVER AREA LONGER...
ALLOWING FOR LONGER PD OF GOOD RADIATIONAL COOLING. TEMPS WILL STAY
WARMER NEAR THE GREAT LAKES...IN THE UPPER 40S TO MID 50S.

MON...12Z NAM/GFS STILL GENERATE SOME LIGHT PCPN ASSOCIATED WITH
PASSAGE OF NEXT NW SHORTWAVE MOVING DOWN BACKSIDE OF MID-LVL TROF.
HOWEVER...LACK OF ANY SIGNIFICANT MOISTENING OR DEEP LYR Q-VECT CONV
AS WELL AS MARGINAL INSTABILITY (< 100 J/KG) SHOULD YIELD ONLY
PARTLY CLOUDY SKIES AND DRY CONDITIONS PER CANADIAN/ECMWF MODELS.
WITH H85 TEMPS FM 6-8C UNDER CONTINUED LIGHT NRLY FLOW...EXPECT HI
TEMPS FM MID 60S ALONG LAKE SUPERIOR TO LOWER 70S SOUTH CENTRAL.

TUESDAY THROUGH FRIDAY...LATEST 00Z RUN OF ECMWF TRENDING FARTHER
NORTH AND NOT AS DEEP WITH NEXT NW FLOW SHORTWAVE TUE NIGHT AND WED
PER CANADIAN MODEL. IT LOOKS LIKE BEST FORCING WILL STAY WELL NORTH
SO HAVE TRIMMED BACK POPS TO SLIGHT CHC TUE NIGHT INTO WEDNESDAY
NIGHT. THE GLOBAL GEM AND TO LESSER EXTENT THE ECMWF SHOW A
SHORTWAVE/VORT MAX APPROACHING FROM THE NRN PLAINS LATE THU.
INCREASING WAA IN RESPONSE TO THIS SHORTWAVE AS NOTED ON ECMWF COULD
TRIGGER SOME ISOLD SHRA/TSRA LATE THU. CHC POPS FOR CONVECTION
WARRANTED BY FRIDAY AS ECMWF AND CANADIAN MODEL ADVERTISE INCREASING
Q-VECT CONV...WAA AND DIFLUENT MID-LVL FLOW AHEAD OF SHORTWAVE
MOVING IN FM THE NRN PLAINS.
&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 738 AM EDT SAT AUG 18 2012

UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT APPROACHING FROM
ONTARIO WILL BRING INCREASING CLOUDS AND POTENTIAL FOR -SHRA AT
KIWD/KCMX/KSAW TODAY. AT THIS TIME...IT APPEARS CONDITIONS WILL
REMAIN VFR PER UPSTREAM OBS. HOWEVER...AS SOME INSTABILITY BUILDS
WITH DAYTIME HEATING...-SHRA MAY BECOME HEAVIER...LEADING TO MVFR
CONDITIONS...ESPECIALLY AT KSAW. IN ADDITION...THERE IS A SMALL RISK
OF TSRA...MAINLY AT KSAW DUE TO EXPECTED BETTER DAYTIME HEATING THIS
MORNING. WITH EXPECTED LIMITED COVERAGE OF TSRA...DID NOT INCLUDE
MENTION IN FCST YET. RAINFALL TODAY MAY LEAD TO FOG TONIGHT...MAINLY AT
KIWD/KSAW. WILL NEED TO REASSESS THIS POTENTIAL IN LATER FCSTS.
&&

.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 500 AM EDT SAT AUG 18 2012

A GENERALLY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES WILL
RESULT IN WINDS MOSTLY UNDER 20KT THRU THE MIDDLE OF THE UPCOMING
WEEK.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...ROLFSON
LONG TERM...VOSS
AVIATION...ROLFSON
MARINE...ROLFSON







AREA FORECAST DISCUSSION

NWS NEWPORT/MOREHEAD CITY NC

 1140 AM EDT SAT AUG 18 2012

.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE AREA TODAY...THEN STALL OVER
EASTERN NORTH CAROLINA TONIGHT INTO MONDAY BEFORE MOVING
OFF THE COAST TUESDAY. HIGH PRESSURE WILL BUILD INTO THE AREA
TUESDAY AND WEDNESDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1100 AM SATURDAY...UPDATED TO DELAY LIKELY POPS FOR
SHOWERS/TSTMS UNTIL PRIME CONVECTIVE TIME OF 2 PM TO 6 PM. MOST
MODELS WERE OVERDONE WITH PCPN FCST DURING MORNING HOURS WITH ONLY
SCT ACTIVITY ACCOMPANYING THICKER CLOUD LAYER WITH SHRT WV. SKIES
HAVE CLEARED BEHIND THIS FEATURE AND SFC OBS INDICATE WIND SHIFT
WITH FRONTAL BNDRY HAS PUSHED INTO NRN OBX AND COASTAL PLAINS. THIS
WILL ALLOW GOOD HEATING OVER INLAND SECTIONS THROUGH EARLY AFTN AND
CONVERGENCE ALONG BNDRY AND SEA BREEZE MOVING INLAND EXPECTED TO
PRODUCE GOOD COVERAGE OF SHOWERS/TSTMS...THUS CONTINUED LIKELY POPS
ALL BUT CENTRAL AND SRN OBX. SLGT RISK OF SVR FOR AREA MAY BE
SLIGHTLY OVERDONE WITH GENERALLY WEAK WIND FIELDS SUPPORTING ONLY
ISOLATED SVR. NO CHANGES TO TEMPS.

/PREVIOUS DISCUSSION/
AS OF 635 AM SATURDAY...NO CHANGES TO PREVIOUS THINKING. A BROAD
UPPER TROUGH WITH SEVERAL EMBEDDED SHORTWAVES CONTINUES OVER THE
CENTRAL AND EASTERN US. ISOLATED SHOWERS AND THUNDERSTORMS HAVE
DEVELOPED EARLY THIS MORNING BUT MOST OF EASTERN NC IS DRY. A
WEAK COLD FRONT WILL BE MOVING INTO THE AREA AND IS EXPECTED TO
ENHANCE THE SHOWER AND THUNDERSTORM THREAT TODAY. ALL OF THE
GUIDANCE IS INDICATING THAT THE PRECIPITATION WILL DEVELOP RAPIDLY
THIS MORNING AND HAVE INCREASED EARLY POPS TO LIKELY ALL BUT THE
FAR EAST ZONES BUT HAVE DELAYED ONSET OF WIDESPREAD PRECIPITATION
FROM 11Z TO 14Z. SPC CONTINUES TO HAVE EASTERN NC IN A "SLIGHT
RISK FOR SEVERE" TODAY DUE TO MODERATE INSTABILITY AND UPPER LEVEL
SHEAR WHICH WOULD SUPPORT MULTI-CELL CLUSTERS CAPABLE OF PRODUCING
DAMAGING WIND GUSTS AND LARGE HAIL. LIMITING FACTOR WILL BE CLOUD
DECK MOVING INTO EASTERN NC EARLY THIS MORNING (ALTHOUGH LOOKS
LIKE THESE CLOUDS ARE BEGINNING TO ERODE)...AND EXPECTED EARLY
START TO THE PRECIPITATION. TREND OF MID CLOUD DECK ACROSS EASTERN
NC THIS MORNING IS FOR CLOUDS TO DISSIPATE SO WE WILL HAVE AT
LEAST POCKETS OF SUBSTANTIAL HEATING. WITH PW VALUES AROUND 2"
LOCALLY HEAVY RAINS WILL OCCUR WITH URBAN AND POOR DRAINAGE
FLOODING POSSIBLE IF TRAINING OF CELLS OCCURS.

HIGH TEMPERATURES TODAY WILL HIGHLY DEPENDENT ON THE AMOUNT OF
INSOLATION THAT OCCURS. I WENT WITH A BLEND OF THE COOL MET (LOWER
80S) AND WARMER MAV (UPPER 80S) TO YIELD HIGHS IN THE MIDDLE 80S
AREA WIDE. SOUTHERLY WINDS EARLY WILL GRADUALLY SHIFT TO THE LIGHT
NORTHWEST AND NORTH THIS AFTERNOON.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 340 AM SATURDAY...THERE IS STRONG AGREEMENT IN THE GUIDANCE
SUGGESTING A DRYING TREND LATE THIS EVENING AND OVERNIGHT AS THE
FRONT OR WIND SHIFT BRIEFLY MOVES JUST OFF OF THE COAST SO WILL
INDICATE A DRY PERIOD AFTER 06Z WITH SCATTERED SHOWERS AND
THUNDERSTORMS ENDING IN THE EVENING. OVERNIGHT LOWS WILL RANGE
FROM THE MIDDLE TO UPPER 60S INLAND TO TO THE LOWER TO MIDDLE 70S
ALONG THE COAST.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 340 AM SAT...AN UNSETTLED PATTERN WILL BE THE RULE THROUGH
EARLY NEXT WEEK. SLOW-MOVING COLD FRONT IN THE WESTERN PART OF THE
STATE WILL SLOWLY APPROACH THIS WEEKEND...EVENTUALLY DRIFTING OFF
THE COAST EARLY NEXT WEEK. HAVE KEPT POPS IN THE CHANCE CATEGORY
FOR SUNDAY BUT BUMPED UP POPS TO 50 PERCENT SUNDAY NIGHT AND 60
PERCENT MONDAY AS BETTER VORT ENERGY IN THE LOWER AND MID LEVELS
PASSES THROUGH.

ATMS SHOULD DRY OUT SLOWLY TUE AS FRONT MOVES OFFSHORE. UPPER
TROUGH WILL MOVE INTO THE EASTERN US EARLY NEXT WEEK THROUGH MID
WEEK RESULTING IN LOW LEVEL N/NE FLOW...CLOUDY CONDITIONS AND
TEMPS SLIGHTLY BELOW NORMAL...HIGHS GENERALLY LOW TO MID 80S AND
OVERNIGHT LOWS IN THE MID 60S TO MID 70S. UPPER FLOW BEGINS TO
BECOME MORE ZONAL LATE WEEK WITH TEMPS LIKELY WARMING A FEW
DEGREES.

&&

.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SATURDAY NIGHT/...
AS OF 1240 AM SATURDAY...WIDESPREAD MID AND OPAQUE HIGH CLOUDS
WILL CONTINUE TO SPREAD EAST OVER EASTERN NC OVERNIGHT AND HELP TO
SUPPRESS RADIATIONAL COOLING AND THUS DENSE FOG POTENTIAL OVERNIGHT
WITH ONLY A BRIEF PERIOD OF MVFR FOG POSSIBLE AT THE TAF SITES.
SCATTERED SHOWERS AND STORMS ARE EXPECTED TO REDEVELOP LATE
TONIGHT AS THE SHORTWAVE MOVES INTO THE AREA AND WILL CONTINUE
THROUGH MUCH OF SATURDAY AS A WEAK COLD FRONT AND DEEPER MOISTURE
MOVES INTO THE AREA. SOMEWHAT DRIER AIR IS FORECAST TO SPREAD INTO
EASTERN NC SATURDAY NIGHT WHICH WILL LEAD TO A DECREASE IN IN
SHOWER THUNDERSTORM ACTIVITY AFTER 00Z.

LONG TERM /SUNDAY THROUGH WEDNESDAY/...
S OF 340 AM SAT...LOCALLY LOWER VSBYS/CIGS THIS WEEKEND THROUGH
EARLY NEXT WEEK IN SCATTERED SHOWERS AND THUNDERSTORMS. ACTIVITY
WILL BECOME ISOLATED BY MIDWEEK. SOUTHWEST SURFACE FLOW CONTINUES
THROUGH TUESDAY MORNING THEN BECOMES LIGHT AND VARIABLE. WINDS
WILL THEN BECOME LIGHT EAST TO NORTHEAST FOR WEDNESDAY.

LOW LEVEL N/NE FLOW WILL LIKELY RETURN TUE/WED AS HIGH PRESSURE
BUILDS BEHIND THE FRONTAL BOUNDARY...LOWERED CIGS WILL BE
POSSIBLE.

&&

.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1100 AM SATURDAY...UPDATED FOR WINDS SHIFTING OVER NRN WATERS
THIS AFTN WITH FRONTAL PROTRUSION. RUC13 APPEARS TO HAVE BEST HANDLE
ON CURRENT WINDS WITH FRONT MOVING INTO NRN WATERS WITH NRLY WINDS
OBSERVED JUST N OF VA BORDER. WIND SHIFT WITH THIS FEATURE EXPECTED
TO PUSH INTO NRN PAMLICO SOUND AND BETWEEN HAT AND ORE INLET EARLY
AFTN. SW WINDS 15 KT OR LESS WILL PREVAIL OVER SRN HALF OF WATERS.

/PREVIOUS DISCUSSION/
AS OF 635 AM SATURDAY...NO CHANGES TO PREVIOUS THINKING. SOUTHERLY
FLOW TO 15 KT CONTINUES AHEAD OF APPROACHING WEAK COLD FRONT. THIS
FLOW IS FORECAST TO CONTINUE THROUGH THIS MORNING THEN RELAX THIS
AFTERNOON AND TONIGHT AS A WEAK COLD FRONT BECOMES MORE DIFFUSE
AND SETTLES OVER THE NORTHERN AND CENTRAL NC WATERS DECREASING THE
PRESSURE GRADIENT. WINDS WILL BRIEFLY SHIFT TO THE NORTHWEST AND
NORTH AS THE FRONT IS FORECAST TO STALL JUST OFF OF THE NORTHERN
AND CENTRAL WATERS. 2-3 FT SEAS ARE EXPECTED THROUGH TONIGHT WITH
SOME 4 FT SETS ACROSS THE OUTER WATERS POSSIBLE THIS MORNING. THE
SEAS WILL BE A COMBINATION OF A ESE SWELL AT 9 SECONDS AND A S TO
SW WIND WAVE WITH A PERIOD AROUND 5 SECONDS.

LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 340 AM SAT...MODELS IN GOOD AGREEMENT SUNDAY...BUT BY EARLY
NEXT WEEK THE 00Z GFS HAS A MORE AMPLIFIED SOLUTION AS COMPARED TO
THE 17/12Z ECMWF AND THE SREF. SO FOR THIS PACKAGE I HAVE USED A
BLEND OF THESE TWO MODELS. THE SLOW-MOVING COLD FRONT WILL DRIFT
OFF THE COAST EARLY NEXT WEEK. BY WEDNESDAY THE SURFACE HIGH WILL
MOVE OVER THE REGION. THE SOUTHWEST FLOW WILL CONTINUE FROM SUNDAY
THROUGH TUESDAY MORNING AND THEN BECOME LIGHT AND VARIABLE. WINDS
WILL THEN BECOME LIGHT EAST TO NORTHEAST FOR WEDNESDAY. NO
HEADLINES EXPECTED AS WINDS AND SEAS WILL REMAIN BELOW SMALL
CRAFT LEVELS.

&&

.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JME
NEAR TERM...JME/JBM
SHORT TERM...JME
LONG TERM...HSA
AVIATION...JME/HSA
MARINE...JME/HSA/JBM







AREA FORECAST DISCUSSION

NWS TUCSON AZ

 250 PM MST SAT AUG 18 2012

.SYNOPSIS...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS THIS WEEK. DAYTIME TEMPERATURES WILL AVERAGE A
FEW DEGREES BELOW NORMAL.

&&

.DISCUSSION...SCATTERED SHOWERS AND THUNDERSTORMS ONGOING IN AN ARC
FROM SELLS-NOGALES-CHIRICAHUA NATIONAL MONUMENT. OTHER SHOWERS AND
THUNDERSTORMS WERE MOVING SWWD ACROSS NRN GREENLEE COUNTY. 18/12Z
UNIV OF AZ GFS-WRF AND 18/18Z RUC HRRR DEPICTED SIMILAR SOLUTIONS
INTO THIS EVENING. IN SUMMARY...SHOWERS/TSTMS EXPECTED TO REMAIN
SOUTH OF THE TUCSON METRO AREA AND SUBSEQUENTLY DIMINISH THIS
EVENING. ALSO...SHOWERS/TSTMS PROGGED TO MOVE SWWD ACROSS PORTIONS
OF GRAHAM COUNTY AND THEN DIMINISH THIS EVENING.

THE OFFICIAL FORECAST DEPICTS A CHANCE OF SHOWERS/TSTMS MOST
SECTIONS THIS EVENING FOLLOWED BY A SLIGHT CHANCE OF SHOWERS/TSTMS
MOST SECTIONS LATE TONIGHT. BASED ON THE AFOREMENTIONED MESOSCALE
SOLUTIONS...WOULD NOT BE SURPRISED TO SEE POPS FOR TONIGHT REDUCED
SIGNIFICANTLY BY THE EVENING SHIFT.

591 DM HIGH PRESSURE PROGGED TO BE CENTERED OVER NRN AZ SUN. UPPER
HIGH TO REMAIN QUASI-STATIONARY MON-TUE...THEN 18/12Z ECMWF DEPICTS
UPPER RIDGE TO BE FLATTENED LATER IN THE WEEK AS SHORTWAVE TROUGH
MOVES EWD ACROSS THE GREAT BASIN. THERE WILL BE ENOUGH MOISTURE TO
MAINTAIN A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS/TSTMS
ACROSS MUCH OF THE AREA THROUGH THURSDAY.

THEREAFTER...18/12Z GFS/ECMWF WERE SIMILAR WITH DEPICTING A DRYING
TREND FRI-SAT. HAVE MADE ONLY VERY MINOR CHANGES TO THE INHERITED
GRIDDED DATA POPS FOR FRI-SAT. THE UPSHOT...A CHANCE OF
AFTERNOON/EVENING SHOWERS/TSTMS EAST AND SOUTH OF TUCSON BY
SAT...AND A SLIGHT CHANCE OF AFTERNOON AND EVENING SHOWERS/TSTMS
ACROSS PIMA/SOUTH CENTRAL PINAL COUNTIES.

HIGH TEMPS SUN-SAT TO AVERAGE A COUPLE OF DEGS OR SO BELOW NORMAL.

&&

.AVIATION...SCT TSRA/SHRA THIS EVENING THEN A SLIGHT CHANCE OF
-TSRA/-SHRA LATE TONIGHT. BRIEF WIND GUSTS MAY APPROACH 40 KTS WITH
THE STRONGEST TSRA THRU EARLY THIS EVENING. SCT TSRA/SHRA MAINLY
EAST OF KTUS SUNDAY AFTERNOON. OTHERWISE...VFR CONDITIONS AND
SURFACE WIND LESS THAN 10 KTS THRU SUNDAY AFTERNOON OR 20/00Z.
AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.

&&

.FIRE WEATHER...EXPECT SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS THIS WEEK.

&&

.TWC WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$






AREA FORECAST DISCUSSION

NWS PUEBLO CO

 1101 AM MDT SAT AUG 18 2012

.UPDATE...
UPDATED FORECAST TO REMOVE THUNDERSTORMS ACROSS NORTHERN PORTIONS
OF THE SOUTHEAST PLAINS FOR THE REMAINDER OF THE MORNING.  HIGH
RES SHORT TERM MODELS HAVE BEEN TRENDING THE FRONT SOUTHWARD WITH
DRIER LOW LEVEL AIRMASS MOVING INTO SE CO THROUGH THE AFTERNOON. HRRR HAS
DEW POINTS DROPPING BACK INTO THE LOWER TO MID 40S ACROSS SOUTHERN
PORTIONS OF THE SOUTHEAST PLAINS...WITH 30S ACROSS THE NRN I-25
CORRIDOR BY 21Z. RUC AND NAM12 A LITTLE MORE OPTIMISTIC KEEPING
SOME LOWER 50 DEW POINTS IN ACROSS BACA COUNTY THROUGH
21Z...BEFORE DROPPING THEM INTO THE 40S TOWARDS 00Z. DEW POINTS
ALREADY A LITTLE DRIER AT KSPD THAN NAM12...AND RAP HAD
PREDICTED. THUS APPEARS BEST CHANCE FOR THUNDERSTORMS WILL BE
ALONG THE EASTERLY UPSLOPE REGIONS OF THE SE MTS...MAINLY WETS AND
SANGRES...AS WELL AS ALONG THE FRONT ACROSS NE NM/TX PANHANDLES
WHERE SFC CONVERGENCE WILL BE MAXIMIZED. IF AN ISOLATED STORM CAN
GET GOING DUE TO ELEVATED HEATING ALONG THE RATON RIDGE/SRN CO
BORDER AREA...IT COULD BRIEFLY STRENGTHEN AS IT MOVES SOUTHWARD
INTO NM/OK PANHANDLE...AS DEEP LAYER SHEARS WILL BE RUNNING AROUND
40 KTS. ALL DEPENDS ON THE AMOUNT OF LOW LEVEL MOISTURE AND TIMING
OF THE DRIER AIR MOVING IN. WILL MAINTAIN SOME ISOLATED POPS ALONG
THE BORDER FOR NOW...WITH POTENTIAL FOR A STRONG STORM OR TWO
(JUST BELOW SEVERE LIMITS) IN THE HAZARDOUS WEATHER OUTLOOK. -KT

&&

.AVIATION...

GUSTY NORTH 15-25 KTS AT KCOS WILL GRADUALLY DECREASE AND SWING
AROUND FROM THE EAST AROUND 10-15 KTS IN THE LATE AFTERNOON. KPUB
WILL SEE LIGHTER WINDS...THOUGH THESE SHOULD INCREASE FROM THE
EAST AT AROUND 10-15 KTS DURING AFTERNOON. ISOLATED TO SCATTERED
AFTERNOON THUNDERSTORMS WILL DEVELOP ACROSS THE MOUNTAINS. THESE
SHOULD DIMINISH AS THEY DRIFT OFF INTO THE MORE STABLE COOLER AIR
ACROSS THE SOUTHEAST PLAINS...AND SHOULD NOT AFFECT THE KCOS OR
KPUB TAF SITE. KALS MAY HAVE THE BEST POTENTIAL OF SEEING A STRAY
VCTS...THOUGH COVERAGE MAY TO TOO LIMITED TO WARRANT INCLUSION IN
THE TAF AS AIRMASS OVER THE REGION WILL BE DRIER THAN YESTERDAY.
THUNDERSTORMS WILL DIMINISH AFTER SUNSET WITH LIGHT DIURNALLY
DRIVEN WINDS UNDER 10 KTS. -KT


&&

.PREV DISCUSSION... /ISSUED 338 AM MDT SAT AUG 18 2012/

SHORT TERM...

(TODAY AND TONIGHT)

CURRENTLY...

A LINE OF SHOWERS/TSRA WERE NOTED EXTENDING NW-SE OVER NE CO. THIS
BAND OF PRECIP WAS MOVING SE. OTHER VERY LIGHT SHOWERS WERE NOTED
OVER EC CO. SOME LIGHT SHOWERS WERE ALSO NOTED OVER SW CO. AN AREA
OF LOW PRESSURE WAS IN THE FT MORGAN AREA AND IT WAS PROGRESSING
SWD. THIS ACTIVITY WAS ASSOCIATED WITH A SHORTWAVE IN THE NW FLOW
ALOFT WHICH WAS MOVING SE.

TODAY AND TONIGHT...

SHOWER ACTIVITY WILL CONTINUE TO MOVE/DEVELOP SE THROUGH THE MORNING
HOURS. SOME OF THIS SHOWER/TSRA ACTIVITY WILL AFFECT THE NE SECTIONS OF
THE CWA...MAINLY KIOWA COUNTY. THE BEST CHANCE OF SHOWERS ACROSS
THIS REGION WILL BE BETWEEN 5 AM AND 11 AM THIS MORNING. AFTER THE
DISTURBANCE MOVES THROUGH THE THREAT OF PRECIP OVER THE FAR E PLAINS
IS EXPECTED TO BE NEAR ZERO AS COOLER MORE STABLE AIR MOVES INTO THE
EASTERN PLAINS.

SHOWER ACTIVITY WILL ONCE AGAIN REDEVELOP OVER THE EAST FACING
SLOPES OF THE EASTERN MOUNTAINS...ESPECIALLY THE S SANGRE MTNS BY
EARLY AFTERNOON. FARTHER NORTH...SHOWERS WILL BE POSSIBLE BUT WILL
BE MUCH MORE ISOLATED. FOR THE PIKES PEAK AREA...ISOLATED
SHOWERS/TSRA WILL BE POSSIBLE...BUT WILL LIKELY FORM AFTER 2 PM.

THE SAN JUANS WILL ALSO SEE A GOOD CHANCE OF SHOWERS/TSRA BY THIS
AFTERNOON. OVER THE REST OF THE INTERIOR MTNS THE PRECIP WILL BE
MORE ISOLATED.

TEMPS WILL BE QUITE NICE WITH TEMPS A COUPLE OF DEGREES BELOW NORMAL
THIS AFTERNOON.

AS FOR THE PLAINS...IT WILL BE DRY. THE ONLY EXCEPTION MAY BE DOWN
ALONG THE CO/NM/OK BORDER WHERE AN ISOLD TSRA MAY DEVELOP DURING THE
AFTERNOON. GIVEN THE NW FLOW ALOFT...THIS ACTIVITY WILL QUICKLY MOVE
SOUTH OUT OF THE STATE. IT WILL BE BREEZY OVER THE PLAINS TODAY AS
THE FRONT MOVES S ACROSS THE REGION THIS MORNING. BY THIS AFTERNOON
NE WINDS OF 10-20 MPH WILL BE COMMON.

FOR THIS EVENING...ANY PRECIP...IF OCCURRING...WILL LIKELY BE ALONG
THE CO/NM BORDER OR SAN JUANS...AND WILL QUICKLY DISSIPATE. TEMPS
TONITE WILL MAINLY BE IN THE 50S PLAINS...WITH 30S AND 40S
MTNS/VALLEYS. /34

LONG TERM...
(SUNDAY THROUGH NEXT SATURDAY)

MAIN FORECAST CONCERNS CONTINUE TO CENTER ON IMPACT OF FRONTAL
SYSTEMS THAT WILL AFFECT THE AREA FIRST ON MONDAY AND AGAIN LATE
WED OR THU. OVERALL PICTURE CONTINUES TO LOOK PRETTY TYPICAL FOR
LATE AUGUST.

SUN-MON SHOULD BE THE COOLEST DAYS OF THE PERIOD IN THE WAKE OF A
FRONTAL PASSAGE THIS WEEKEND. EXPECT TEMPS IN THE LOWER TO MID 80S
FOR THE PLAINS BOTH DAYS. SUNDAY CONTINUES TO LOOK MOSTLY DRY...WITH
MOST OF THE PRECIP CONFINED TO THE SRN MTS IN THE AFTERNOON-EVE. GFS
STILL IS OVERDONE WITH QPF...BUT IN FOLLOWING THE NAM SOLUTION HAVE
BUMPED UP POPS SLIGHTLY FOR THE NRN MT RANGES...INCLUDING PIKES
PEAK...FOR THE LATE AFTERNOON.

NEXT FRONT ARRIVES EARLY ON MON...AND WILL RESULT IN MORE
WIDESPREAD SHOWERS OVR THE CWA. AFTER A BIT OF A LULL IN THE
PRECIP MID DAY...COULD SEE AN INCREASE IN SHWR ACTIVITY AGAIN IN
THE LATE AFTERNOON THRU EARLY EVE AS UPSLOPE WINDS COMBINE WITH
SOME MODEST INCREASE IN INSTABILITY. SEVERAL CONVECTIVE COMPLEXES
ARE POSSIBLE BY LATE MON EVE...BUT SHOULD BE MOSTLY E OF OUR AREA
BY THAT TIME. WILL HANG ON TO SOME LOW POPS NR THE KS/OK BORDERS
THRU MON NIGHT.

TUE THRU WED THE RIDGE REBUILDS OVR THE ROCKIES AND TEMPS WILL
REBOUND OVR THE PLAINS TO THE UPPER 80S AND POSSIBLY LOWER 90S.
MOISTURE WILL LARGELY BE CONFINED TO THE SRN MTS...SAN JUANS AND
SPANISH PEAKS REGION. COULD SEE SOME SPOTTY HEAVY AMTS OF PRECIP
OVR THE SAN JUANS THRU THIS PERIOD. NEXT...MORE SIGNIFICANT...FRONT
ARRIVES LATE WED OR EARLY THU...AND THIS SHOULD BRING A GOOD CHANCE
OF SHOWERS TO ALL OF SE CO. THE UPPER RIDGE LOOKS TO REBUILD LATE
IN THE WEEK FOR MORE DRY AND WARM WX. 44

AVIATION...

VFR EXPECTED AT KCOS AND KPUB NEXT 24. KALS MAY SEE AND ISOLD TSRA
LATE THIS AFTERNOON...OTHERWISE VFR. A COOL FRONT WILL MOVE ACROSS
KCOS AOA 15-16Z WITH SOME GUSTY N WINDS AFTER FROPA. THE FRONT WILL
COME ACROSS KPUB ABOUT AN HOUR LATER. WINDS ON THE PLAINS WILL SHIFT
TO THE NORTHEAST THIS AFTERNOON.

&&

.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

31/23






AREA FORECAST DISCUSSION

NWS PEACHTREE CITY GA

 321 PM EDT SAT AUG 18 2012

.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
EXPECT AN ACTIVE WEATHER PATTERN THROUGH THE SHORT TERM. SURFACE
ANALYSIS SHOWS A COLD FRONT NEAR A CARROLLTON TO ATLANTA TO ATHENS
LINE. EXPECT A STRONG UPPER DISTURBANCE OVER MS TO TRAVERSE THE AREA
AND SPARK ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ALONG AND
SOUTH OF THE FRONT THROUGH MID EVENING. THIS ACTIVITY SHOULD
DIMINISH BY MIDNIGHT... BUT THE BREAK MAY BE SHORT LIVED AS A SERIES
OF DISTURBANCES BEGIN TO CARVE A LONG WAVE TROUGH ALONG THE LOWER MS
VALLEY REGION OVERNIGHT AND ON SUNDAY. AS A RESULT... EXPECT A VERY
ACTIVE SW FLOW ALOFT TO INTERACT WITH AN INCREASINGLY MOIST AND
UNSTABLE AIRMASS TO SPARK SCATTERED TO WIDESPREAD CONVECTION ACROSS
MUCH OF THE AREA STARTING EARLY ON SUNDAY AND CONTINUING THROUGH
MONDAY. THE GFS SHOWS A SURFACE LOW DEVELOPING ALONG THE STALLED
FRONT AND SWEEPING ACROSS THE STATE MONDAY NIGHT... WITH THE
TRAILING COLD FRONT FINALLY BRINGING SOME DRIER CONDITIONS TO AT
LEAST NORTH GA BY TUESDAY MORNING. AT THIS TIME...EXPECT THE
STRONGER STORMS TO OCCUR ON MONDAY AS THE UPPER TROUGH DEEPENS AND A
SURFACE LOW PUSHES INTO THE STATE DURING DAYTIME HEATING. ALTHOUGH .
AMPLE CLOUD COVER AND WIDESPREAD SHOWERS SHOULD HELP HINDER SEVERE
STORM DEVELOPMENT ON SUNDAY AND MONDAY... THE INCREASED FORCING
EXPECTED ON MONDAY WARRANTS GREATER CONCERN FOR MONDAY AFTERNOON AND
EVENING. SPC DOES NOT HAVE THE FORECAST AREA OUTLOOKED AT THIS
TIME... BUT WILL MONITOR THIS POTENTIAL CLOSELY GOING INTO MONDAY.
OTHERWISE...LEANED TOWARD A MAV AND MET BLEND FOR LOWS AND HIGHS
THROUGH THE PERIOD WITH SOME UNCERTAINTY ON TIMING AND COVERAGE OF
CONVECTION AT THIS TIME.

39

&&

.LONG TERM /TUESDAY THROUGH SATURDAY/...
OVERALL GUIDANCE IN BETTER AGREEMENT THAN YESTERDAY WITH MAIN
INFLUENCING FEATURES FOR THE MAJORITY OF THE LONG TERM. THROUGH
TUESDAY BOTH THE GFS AND ECMWF KEEP THE MOISTURE FIELD SOUTH OF THE
NEARLY STATIONARY SFC FRONT ACROSS CENTRAL GEORGIA...WHICH
EVENTUALLY SAGS ACROSS SOUTHERN GEORGIA FOR WEDNESDAY INTO THURSDAY.
CURRENT POPS OF LOW END CHANCE IN THE SOUTH TO SLIGHT NORTHWARD
THROUGH THIS PERIOD SEEM REASONABLE. THE ECMWF HINTS AT A WEAK UPPER
LOW DRAWING MOISTURE IN A BIT FARTHER NORTHWARD THAN THE GFS ON
THURSDAY... BUT THERE IS DECENT UNCERTAINTY IN THIS SOLUTION THIS
FAR OUT SO WILL KEEP BEST CHANCE POPS IN SOUTH AND EAST PORTIONS.
WEAK SFC HIGH BUILDING INTO AREA NEAR END OF THE WEEK SHOULD LIMIT
CONVECTIVE DEVELOPMENT SO WILL ALSO CONTINUE THE CURRENT SLIGHT POPS
FOR THAT TIMEFRAME. NO SIGNIFICANT CHANGES NEEDED TO THE FORECAST
TEMPS AS LATEST MEX GUIDANCE KEEPING BETTER CONSISTENCY BETWEEN RUNS
THAN YESTERDAY. WITH ALL CONSIDERED...FORECAST LOOKS TO BE ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...

03

.PREVIOUS DISCUSSION ISSUED AT 426 AM EDT SAT AUG 18 2012/...

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CWA REMAINS UNDER THE INFLUENCE OF A LONGWAVE TROUGH AT THE
BEGINNING OF THE LONG TERM. LATEST GUIDANCE STILL BRINGS A WAVE
ACROSS THE CWA NEAR THE BEGINNING OF THE LONG TERM BUT ABOUT 12
HOURS EARLIER THAN SUGGESTED YESTERDAY WITH MODELS SHOWING SUNDAY
NIGHT NOW. ALTHOUGH NAM/GFS/ECMWF/SREF SHOW SOME REFLECTION OF A
SFC LOW ASSOCIATED WITH THIS DISTURBANCE...THE GFS IS BY FAR THE
STRONGEST AND APPEARS TO BE OVERDONE ON STRENGTH AND PRECIP. AT
LEAST THROUGH MONDAY...LEANED TOWARD THE NAM/ECMWF SOLUTION TO
ACCOUNT FOR THE OVERDONE GFS. MAIN IMPACT WAS TO POPS THAT ARE IN
THE SLIGHT CHANCE TO LIKELY CATEGORY THROUGH MONDAY AS OPPOSED TO
THE LIKELY AND CATEGORICAL POPS SUGGESTED BY THE GFS. AFTER THE
INFLUENCES FROM THE WAVE ON MONDAY MOVES OUT OF THE CWA...RAIN
CHANCES DECREASE. BEST MOISTURE REMAINS ACROSS SOUTHERN HALF OF
CWA SO HAVE CONTINUED TO SHOW BEST POPS ACROSS THAT AREA. BY
MIDWEEK...LONGWAVE TROUGH CONTINUES TO BREAK DOWN ACROSS THE AREA
AND BEST MOISTURE CONTINUES TO SHIFT OFF TO THE EAST AS HIGH
PRESSURE PUSHES INTO THE CWA AT THE SFC. THIS WILL HELP TO LIMIT
POPS TO SLIGHT CHANCE ACROSS THE NORTH AND CHANCE ACROSS THE
SOUTHERN HALF OF THE CWA.

MEX MAX TEMPS ARE SLIGHTLY HIGHER THAN PREVIOUS RUN. LIKE THIS TREND
AND HAVE EVEN NUDGED MAX TEMPS UP A DEGREE IN SOME PLACES. MIN TEMPS
APPEAR A LITTLE COOL DURING THE WORK WEEK...SO HAD TO MAKE SOME
ADJUSTMENTS UPWARD HERE TOO.

11

&&

.AVIATION...
18Z UPDATE...
VFR CONDITIONS CURRENTLY OVER ALL TAF SITES AND EXPECTED TO PREVAIL
THROUGH THE TAF PERIOD. A COLD FRONT REMAINS NEARLY STATIONARY
ACROSS THE ATLANTA METRO AREA... AND WITH AN ACTIVE WESTERLY FLOW
ALOFT...EXPECT ANOTHER ROUND OF SCATTERED CONVECTION BY LATE
AFTERNOON-EARLY EVENING. LATEST HRRR MODEL INDICATES CONVECTION WILL
FIRE NEAR THE FRONT AND BRUSH THE ATLANTA AREA TAF SITES BY
21-23Z...BUT KEEPS THE MAIN CONVECTION JUST SOUTH OF ATL. WILL PLAY
IT SAFE AND CONTINUE TO SHOW TEMPO -TSRA 21-24Z FOR ALL TAF SITES
TODAY. MODELS AGREE ON WIDESPREAD CONVECTION MOVING IN LATE TONIGHT
AND PREVAILING ON SUNDAY. WILL SHOW VCSH BY 09Z...AND PREVAILING
-SHRA BY 12Z WITH PROB30 -TSRA 12-19Z SUN FOR NOW. WINDS WILL REMAIN
MAINLY WESTERLY AT 8KTS OR LESS.

//ATL CONFIDENCE...
18Z UPDATE...
MODERATE CONFIDENCE ON CONVECTION AND TIMING. HIGH CONFIDENCE ON
ALL OTHER ELEMENTS.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          68  86  68  84 /  30  50  60  60
ATLANTA         69  86  69  83 /  30  60  60  60
BLAIRSVILLE     62  80  66  80 /  20  30  50  50
CARTERSVILLE    68  85  67  84 /  30  50  60  60
COLUMBUS        72  87  70  84 /  30  60  70  70
GAINESVILLE     68  85  68  83 /  30  50  60  60
MACON           71  88  70  86 /  30  60  70  70
ROME            69  87  68  85 /  30  40  50  60
PEACHTREE CITY  68  86  67  84 /  30  60  60  60
VIDALIA         72  89  72  85 /  30  60  70  70

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...39
LONG TERM...11/03
AVIATION...39






AREA FORECAST DISCUSSION...UPDATE FOR AVIATION

NWS PEACHTREE CITY GA

 144 PM EDT SAT AUG 18 2012

.MID MORNING UPDATE...
/ISSUED AT 1042 AM EDT SAT AUG 18 2012/
LATEST SURFACE MAP SHOWS A COLD FRONT NEARLY STALLED ACROSS NORTH
GA...JUST NORTH OF ATLANTA. A NEARLY ZONAL FLOW ALOFT SUGGEST THE
FRONT MAY ONLY SAG SLIGHTLY SOUTHWARD TODAY... AND THIS WOULD PUT IT
OVER METRO ATLANTA DURING DAYTIME HEATING. THE LATEST HRRR MODEL
SHOWS CONVECTION FIRING ALONG THE FRONT RIGHT OVER ATLANTA AREA BY
21-22Z TODAY...WHILE THE LOCAL WRF MODEL SHOWS SCATTERED CONVECTION
NEAR ATLANTA AND SOUTHWARD. ONGOING CONVECTION CURRENTLY PUSHING
ACROSS NE GA AND ANOTHER AREA PUSHING INTO THE LA GRANGE AREA FROM
ALABAMA WILL CONTINUE TO WEAKEN...BUT EXPECT DIFFERENTIAL HEATING
FROM CLOUD FREE AREAS TO THE EAST AND SOUTH OF THIS CONVECTION TO
PROVIDE A FOCUS FOR STORM DEVELOPMENT LATER TODAY...ESPECIALLY AS
WEAK DISTURBANCES ALOFT TRAVERSE THE STATE FRONT THE WEST. MOISTURE
AND INSTABILITY ARE SUFFICIENT TO SUPPORT SCATTERED STORMS WITH A
MODIFIED 12Z SOUNDING SHOWING AROUND 2500 J/KG OF CAPE WITH 1.70
PW`S AND ALMOST -6 LI`S. WILL UPDATE ZONES TO INCREASE POPS TO THE
30-40% RANGE FROM AREAS JUST NORTH OF ATLANTA SOUTHWARD THROUGH THE
AFTERNOON AND HOLD ONTO A LOW CHANCE ACROSS PARTS OF CENTRAL GA
THROUGH THE EVENING HOURS. WITH THE FRONT STALLING ACROSS THE AREA
OVERNIGHT... WILL ALSO HOLD ONTO A SLIGHT CHANCE POP MOST AREAS
OVERNIGHT. AT THIS TIME... NOT EXPECTING SEVERE...BUT CANNOT RULE
OUT A FEW STRONG STORMS PRODUCING 45 MPH WIND GUSTS...SMALL HAIL AND
FREQUENT LIGHTNING. THE STRONG STORM THREAT SHOULD GREATLY DIMINISH
BY 9-10 PM THIS EVENING WITH LOSS OF HEATING.

.PREVIOUS DISCUSSIONS ISSUED AT 426 AM EDT SAT AUG 18 2012/...

SHORT TERM /TODAY THROUGH SUNDAY/...
COLD FRONT CONTINUES TO SAG SOUTH AND EASTWARD...AND RADAR SHOWING A
FEW SHOWERS ALONG BOUNDARY OVER NORTHERN ALABAMA AND EASTERN
TENNESSEE. SOME DEVELOPMENT HAS STARTED IN NORTHERN GEORGIA. MODELS
SHOWING SOMEWHAT DIFFERENT SOLUTIONS...IN THAT THE NAM WEAKENS THE
BOUNDARY WITH LITTLE MOISTURE OVER THE AREA TODAY. AS SHORT WAVES
MOVE ALONG THE BOUNDARY AND TOWARD THE COAST...IT OFFERS LITTLE
CHANCE OF PRECIP. SUNDAY ANOTHER WAVE MOVES ALONG THE BOUNDARY
BRINGING A GREATER ABUNDANCE OF MOISTURE TO THE AREA SUNDAY...AT
LEAST TO CENTRAL GEORGIA...WHILE THE AIR MASS REMAINS RELATIVELY DRY
OVER THE NORTH. THIS WEAK RIDGE OF HIGH PRESSURE IN THE LOWER
EASTERN TENNESSEE VALLEY PUSHES A DRIER AIR MASS INTO NORTH GEORGIA
WHILE MOISTURE LINGERS TO THE SOUTH. THE GFS HAS THE FRONT MOVING IN
THIS MORNING AS WELL BUT WITH A DRIER AIR MASS BEHIND IT TOO.
HOWEVER...GFS HAS THE MOISTURE INCREASING FOR SUNDAY INTO SUNDAY
NIGHT WITH NO DRY AIR INVASION FROM THE NORTH.

GREAT UNCERTAINTY WITH THIS FORECAST BEYOND TODAY. THE THINKING IS
THAT THE FRONT...THOUGH WEAKENING WILL PUSH INTO GEORGIA AND STALL
OVER MIDDLE GEORGIA THIS AFTERNOON TO GIVE A CHANCE OF SHOWERS...
POSSIBLY THUNDERSTORMS FOR THE AREA. SOME SHOWERS ARE ALSO POSSIBLE
ALONG THE FRONT AT IT MAKES ITS WAY SOUTH.

MOS TEMPERATURES LOOK TO BE CLOSE IN AGREEMENT WITH PREVIOUSLY
OBSERVED TEMPERATURES. HENCE...LITTLE CHANGE FROM MOS
TEMPERATURES.

37

LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
CWA REMAINS UNDER THE INFLUENCE OF A LONGWAVE TROUGH AT THE
BEGINNING OF THE LONG TERM. LATEST GUIDANCE STILL BRINGS A WAVE
ACROSS THE CWA NEAR THE BEGINNING OF THE LONG TERM BUT ABOUT 12
HOURS EARLIER THAN SUGGESTED YESTERDAY WITH MODELS SHOWING SUNDAY
NIGHT NOW. ALTHOUGH NAM/GFS/ECMWF/SREF SHOW SOME REFLECTION OF A SFC
LOW ASSOCIATED WITH THIS DISTURBANCE...THE GFS IS BY FAR THE
STRONGEST AND APPEARS TO BE OVERDONE ON STRENGTH AND PRECIP. AT
LEAST THROUGH MONDAY...LEANED TOWARD THE NAM/ECMWF SOLUTION TO
ACCOUNT FOR THE OVERDONE GFS. MAIN IMPACT WAS TO POPS THAT ARE IN
THE SLIGHT CHANCE TO LIKELY CATEGORY THROUGH MONDAY AS OPPOSED TO
THE LIKELY AND CATEGORICAL POPS SUGGESTED BY THE GFS. AFTER THE
INFLUENCES FROM THE WAVE ON MONDAY MOVES OUT OF THE CWA...RAIN
CHANCES DECREASE. BEST MOISTURE REMAINS ACROSS SOUTHERN HALF OF CWA
SO HAVE CONTINUED TO SHOW BEST POPS ACROSS THAT AREA. BY
MIDWEEK...LONGWAVE TROUGH CONTINUES TO BREAK DOWN ACROSS THE AREA
AND BEST MOISTURE CONTINUES TO SHIFT OFF TO THE EAST AS HIGH
PRESSURE PUSHES INTO THE CWA AT THE SFC. THIS WILL HELP TO LIMIT
POPS TO SLIGHT CHANCE ACROSS THE NORTH AND CHANCE ACROSS THE
SOUTHERN HALF OF THE CWA.

MEX MAX TEMPS ARE SLIGHTLY HIGHER THAN PREVIOUS RUN. LIKE THIS TREND
AND HAVE EVEN NUDGED MAX TEMPS UP A DEGREE IN SOME PLACES. MIN TEMPS
APPEAR A LITTLE COOL DURING THE WORK WEEK...SO HAD TO MAKE SOME
ADJUSTMENTS UPWARD HERE TOO.

11

&&

.AVIATION...
18Z UPDATE...
VFR CONDITIONS CURRENTLY OVER ALL TAF SITES AND EXPECTED TO PREVAIL
THROUGH THE TAF PERIOD. A COLD FRONT REMAINS NEARLY STATIONARY
ACROSS THE ATLANTA METRO AREA... AND WITH AN ACTIVE WESTERLY FLOW
ALOFT...EXPECT ANOTHER ROUND OF SCATTERED CONVECTION BY LATE
AFTERNOON-EARLY EVENING. LATEST HRRR MODEL INDICATES CONVECTION WILL
FIRE NEAR THE FRONT AND BRUSH THE ATLANTA AREA TAF SITES BY
21-23Z...BUT KEEPS THE MAIN CONVECTION JUST SOUTH OF ATL. WILL PLAY
IT SAFE AND CONTINUE TO SHOW TEMPO -TSRA 21-24Z FOR ALL TAF SITES
TODAY. MODELS AGREE ON WIDESPREAD CONVECTION MOVING IN LATE TONIGHT
AND PREVAILING ON SUNDAY. WILL SHOW VCSH BY 09Z...AND PREVAILING
-SHRA BY 12Z WITH PROB30 -TSRA 12-19Z SUN FOR NOW. WINDS WILL REMAIN
MAINLY WESTERLY AT 8KTS OR LESS.

//ATL CONFIDENCE...
18Z UPDATE...
MODERATE CONFIDENCE ON CONVECTION AND TIMING. HIGH CONFIDENCE ON
ALL OTHER ELEMENTS.

39

&&

.PRELIMINARY POINT TEMPS/POPS...
ATHENS          89  69  89  67 /  20  10  50  50
ATLANTA         86  70  85  69 /  20  20  50  40
BLAIRSVILLE     82  60  80  64 /  20  10  20  50
CARTERSVILLE    87  65  86  65 /  20  20  40  40
COLUMBUS        90  72  90  70 /  20  20  50  50
GAINESVILLE     85  68  85  67 /  20  10  40  50
MACON           91  72  91  70 /  20  20  50  50
ROME            88  66  88  66 /  20  20  40  30
PEACHTREE CITY  86  68  87  67 /  20  20  50  40
VIDALIA         91  73  90  72 /  20  20  40  50

&&

.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SHORT TERM...37
LONG TERM....11
AVIATION...37















AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1148 AM MDT SAT AUG 18 2012

.UPDATE...
ISSUED AT 1023 AM MDT SAT AUG 18 2012

THUNDERSTORMS HAVE ENDED FOR TODAY AND REMOVED ALL REMAINING POPS.
SHORTWAVE TROUGH HAS MOVED SOUTHEAST AND SUBSIDENCE IS BUILDING
OVER THE FORECAST AREA IN ITS WAKE WITH MOSTLY SUNNY SKIES.
TEMPERATURES SHOULD EASILY REBOUND TO THE LOWER 8OS FOR HIGHS.

UPDATE ISSUED AT 559 AM MDT SAT AUG 18 2012

JUST COMPLETED AN UPDATE. PRECIPITATION IS FURTHER SOUTH AND WEST
THAN MOST GUIDANCE INDICATES. THE LATEST HRRR HAS FINALLY CAUGHT
ONTO THIS AND USED IT FOR THIS UPDATE. HIGHEST CHANCES WILL BE
CONFINED TO THE EAST AND ESPECIALLY THE SOUTH. PRECIPITATION
SHOULD BE DONE BY 18Z. BASED ON LATEST GUIDANCE AND
TRENDS...UPDATED WINDS...DEWPOINTS AND SKY COVER.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION TODAY...LOW
TEMPERATURES TONIGHT...HIGH TEMPERATURES THROUGH THE SHORT TERM...
AND THE NEXT CHANCE OF PRECIPITATION THE BEGINNING OF NEXT WEEK.
SATELLITE SHOWING AN AMPLIFIED/AMPLIFYING PATTERN FROM THE CENTRAL
PACIFIC INTO THE WESTERN ATLANTIC.

THE MODELS INITIALIZED WELL ON THE JET SEGMENT TO OUR NORTH...
ALTHOUGH THE NAM WAS SLIGHTLY WORSE. THE GFS WAS DOING BETTER AT
MID LEVELS. ON THE SURFACE WINDS...THE ECMWF WAS DOING A LITTLE
BETTER THAN THE NAM. ON THE LOW LEVEL THERMAL FIELD...THE GFS AND
ECMWF WERE DOING A LITTLE BETTER THAN THE UKMET AND SREF.

TODAY/TONIGHT...INCOMING UPPER JET AND SHORTWAVE TROUGH/PV ANOMALY
HAVE BEEN CAUSING THUNDERSTORM DEVELOPMENT FOR THE LAST COUPLE OF
HOURS. MODELS ARE HAVING A LITTLE TROUBLE PLACING THE MAIN AXIS.
OVERALL THEY TEND TO PUT IT TOO FAR NORTH AND EAST. MOST IF NOT ALL
OF THE LIFT WILL PUSH THROUGH BY 18Z. CURRENT GRIDS ADJUSTED BY THE
EVENING SHIFT ARE CAPTURING CURRENT STORMS AND TRENDS WELL AND WILL
LEAVE ALONE AT THIS TIME. WILL MAKE FURTHER ENHANCEMENTS AS TIME
PERMITS.

SHOULD SEE FAIRLY RAPIDLY CLEARING BEHIND STORMS. CURRENT CLOUD
COVER IS HOLDING UP MINS AS WELL SO THEY MAY NOT HAVE THAT FAR TO
GO. TENDED TO DO A BLEND OF THE WARMEST/COOLEST GUIDANCE NEAR THE
CONSENSUS OF MOST OF THE GUIDANCE. IF CLOUD COVER LASTS LONGER...
MAXES WILL HAVE TO BE ADJUSTED DOWN.

JET AND LINGERING LIFT HANG AROUND THROUGH THE NIGHT WHICH MAY
CREATE SPOTTY CLOUD COVER. LIGHT AND VARIABLE WINDS AND LOWER
DEWPOINTS WILL ALLOW TEMPERATURES WILL DROP RAPIDLY. LOWERED MINS
BUT DAY SHIFT WILL HAVE TO TAKE A LOOK AT AGAIN. DO NOT HAVE TIME TO
PUT A CLIMATE SECTION IN BUT RECORD LOWS LOOK TO BE THREATENED
TONIGHT OVER THE ENTIRE AREA.

SUNDAY...WEAK JET SEGMENT LOOKS TO STAY OVER THE AREA THROUGH THE
DAY. LEFT FRONT QUADRANT LOOKS TO AFFECT THE WESTERN AREA IN THE
AFTERNOON. HOWEVER LOOKS TO DO NOTHING WITH AN EXTREMELY AIR MASS
OVER THE AREA. SO LOOK TO HAVE PLENTY OF SUN BUT EASTERLY WINDS AS
THE SURFACE RIDGE MOVES THROUGH. FOLLOWED A CON OF
TEMPERATURE GUIDANCE THAT FELL BETWEEN THE TWO EXTREMES.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

SUNDAY NIGHT...ABOVE MENTIONED JET SEGMENT MOVES ACROSS THE AREA
WITH THE RIGHT REAR QUADRANT AFFECTING THE WESTERN HALF TO TWO
THIRDS BY LATE IN THE NIGHT. AGAIN LOOKS LIKE ONLY CLOUDS SINCE
THERE IS A DEEP DRY LAYER AT THE BOTTOM. WINDS ARE SLOW TO COME UP
WITH THE POTENTIAL FOR RATHER COOL MINS ONCE AGAIN.

MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT STARTS THE DAY OVER THE
AREA AND MOVES EAST OF THE AREA BY MID AFTERNOON. A LEFT FRONT
QUADRANT WILL BEGIN TO AFFECT THE AREA BY LATE EVENING AS IT BEGINS
TO MOVE ACROSS THE AREA. THE MAIN MID LEVEL LIFT LOOKS TO MOVE IN
FROM THE NORTHWEST LATE IN THE DAY. ALL THIS LIFT TENDS TO AFFECT
THE SOUTHWEST HALF TO TWO THIRDS OF THE OTHER WHICH IS A SOUTHWARD
SHIFT SINCE YESTERDAY. ANOTHER PROBLEM IS THAT A LOT OF THE MODEL
OUTPUT IS SUFFERING FROM CONVECTIVE FEEDBACK. OVERALL KEPT THE
HIGHER CHANCE POPS FURTHER SOUTHWEST. ONLY MADE A SLIGHT ADJUSTMENT
ON MAXES BUT IF CLOUD COVER IS THICKER THAN EXPECTED WILL NEED TO
ADJUST DOWN.

TUESDAY THROUGH FRIDAY...DUE TO SHORT TERM CONCERNS/INCREASING
THUNDERSTORM COVERAGE WAS NOT ABLE TO SPEED A LOT OF TIME ON THIS
PERIOD. LINGERING CONVECTION WILL BE OVER THE AREA TUESDAY. MODELS
ARE DIFFERING FROM EACH OTHER IN HOW THEY HANDLE THE WESTERN
RIDGING AND HOW SHORTWAVE ENERGY COMES OVER THE TOP. GENERAL IDEA IS
A SERIES OF SHORTWAVE TROUGHS WILL BRING CONTINUED CHANCES FOR
THUNDERSTORMS THROUGH FRIDAY WITH WEDNESDAY AND THURSDAY HAVING THE
GREATEST COVERAGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1144 AM MDT SAT AUG 18 2012

VFR CONDITIONS EXPECTED AT BOTH KGLD AND KMCK THROUGH THE TAF
PERIOD. SHORTWAVE TROUGH HAS MOVED SOUTHEAST WITH MUCH DRIER AIR
MOVING IN FROM NEBRASKA.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...024
SHORT TERM...BULLER
LONG TERM...BULLER
AVIATION...024





AREA FORECAST DISCUSSION

NWS GOODLAND KS

 1025 AM MDT SAT AUG 18 2012

.UPDATE...
ISSUED AT 1023 AM MDT SAT AUG 18 2012

THUNDERSTORMS HAVE ENDED FOR TODAY AND REMOVED ALL REMAINING POPS.
SHORTWAVE TROUGH HAS MOVED SOUTHEAST AND SUBSIDENCE IS BUILDING
OVER THE FORECAST AREA IN ITS WAKE WITH MOSTLY SUNNY SKIES.
TEMPERATURES SHOULD EASILY REBOUND TO THE LOWER 8OS FOR HIGHS.

UPDATE ISSUED AT 559 AM MDT SAT AUG 18 2012

JUST COMPLETED AN UPDATE. PRECIPITATION IS FURTHER SOUTH AND WEST
THAN MOST GUIDANCE INDICATES. THE LATEST HRRR HAS FINALLY CAUGHT
ONTO THIS AND USED IT FOR THIS UPDATE. HIGHEST CHANCES WILL BE
CONFINED TO THE EAST AND ESPECIALLY THE SOUTH. PRECIPITATION
SHOULD BE DONE BY 18Z. BASED ON LATEST GUIDANCE AND
TRENDS...UPDATED WINDS...DEWPOINTS AND SKY COVER.

&&

.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

FORECAST PROBLEMS WILL BE CHANCE OF PRECIPITATION TODAY...LOW
TEMPERATURES TONIGHT...HIGH TEMPERATURES THROUGH THE SHORT TERM...
AND THE NEXT CHANCE OF PRECIPITATION THE BEGINNING OF NEXT WEEK.
SATELLITE SHOWING AN AMPLIFIED/AMPLIFYING PATTERN FROM THE CENTRAL
PACIFIC INTO THE WESTERN ATLANTIC.

THE MODELS INITIALIZED WELL ON THE JET SEGMENT TO OUR NORTH...
ALTHOUGH THE NAM WAS SLIGHTLY WORSE. THE GFS WAS DOING BETTER AT
MID LEVELS. ON THE SURFACE WINDS...THE ECMWF WAS DOING A LITTLE
BETTER THAN THE NAM. ON THE LOW LEVEL THERMAL FIELD...THE GFS AND
ECMWF WERE DOING A LITTLE BETTER THAN THE UKMET AND SREF.

TODAY/TONIGHT...INCOMING UPPER JET AND SHORTWAVE TROUGH/PV ANOMALY
HAVE BEEN CAUSING THUNDERSTORM DEVELOPMENT FOR THE LAST COUPLE OF
HOURS. MODELS ARE HAVING A LITTLE TROUBLE PLACING THE MAIN AXIS.
OVERALL THEY TEND TO PUT IT TOO FAR NORTH AND EAST. MOST IF NOT ALL
OF THE LIFT WILL PUSH THROUGH BY 18Z. CURRENT GRIDS ADJUSTED BY THE
EVENING SHIFT ARE CAPTURING CURRENT STORMS AND TRENDS WELL AND WILL
LEAVE ALONE AT THIS TIME. WILL MAKE FURTHER ENHANCEMENTS AS TIME
PERMITS.

SHOULD SEE FAIRLY RAPIDLY CLEARING BEHIND STORMS. CURRENT CLOUD
COVER IS HOLDING UP MINS AS WELL SO THEY MAY NOT HAVE THAT FAR TO
GO. TENDED TO DO A BLEND OF THE WARMEST/COOLEST GUIDANCE NEAR THE
CONSENSUS OF MOST OF THE GUIDANCE. IF CLOUD COVER LASTS LONGER...
MAXES WILL HAVE TO BE ADJUSTED DOWN.

JET AND LINGERING LIFT HANG AROUND THROUGH THE NIGHT WHICH MAY
CREATE SPOTTY CLOUD COVER. LIGHT AND VARIABLE WINDS AND LOWER
DEWPOINTS WILL ALLOW TEMPERATURES WILL DROP RAPIDLY. LOWERED MINS
BUT DAY SHIFT WILL HAVE TO TAKE A LOOK AT AGAIN. DO NOT HAVE TIME TO
PUT A CLIMATE SECTION IN BUT RECORD LOWS LOOK TO BE THREATENED
TONIGHT OVER THE ENTIRE AREA.

SUNDAY...WEAK JET SEGMENT LOOKS TO STAY OVER THE AREA THROUGH THE
DAY. LEFT FRONT QUADRANT LOOKS TO AFFECT THE WESTERN AREA IN THE
AFTERNOON. HOWEVER LOOKS TO DO NOTHING WITH AN EXTREMELY AIR MASS
OVER THE AREA. SO LOOK TO HAVE PLENTY OF SUN BUT EASTERLY WINDS AS
THE SURFACE RIDGE MOVES THROUGH. FOLLOWED A CON OF
TEMPERATURE GUIDANCE THAT FELL BETWEEN THE TWO EXTREMES.

.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 240 AM MDT SAT AUG 18 2012

SUNDAY NIGHT...ABOVE MENTIONED JET SEGMENT MOVES ACROSS THE AREA
WITH THE RIGHT REAR QUADRANT AFFECTING THE WESTERN HALF TO TWO
THIRDS BY LATE IN THE NIGHT. AGAIN LOOKS LIKE ONLY CLOUDS SINCE
THERE IS A DEEP DRY LAYER AT THE BOTTOM. WINDS ARE SLOW TO COME UP
WITH THE POTENTIAL FOR RATHER COOL MINS ONCE AGAIN.

MONDAY/MONDAY NIGHT...RIGHT REAR QUADRANT STARTS THE DAY OVER THE
AREA AND MOVES EAST OF THE AREA BY MID AFTERNOON. A LEFT FRONT
QUADRANT WILL BEGIN TO AFFECT THE AREA BY LATE EVENING AS IT BEGINS
TO MOVE ACROSS THE AREA. THE MAIN MID LEVEL LIFT LOOKS TO MOVE IN
FROM THE NORTHWEST LATE IN THE DAY. ALL THIS LIFT TENDS TO AFFECT
THE SOUTHWEST HALF TO TWO THIRDS OF THE OTHER WHICH IS A SOUTHWARD
SHIFT SINCE YESTERDAY. ANOTHER PROBLEM IS THAT A LOT OF THE MODEL
OUTPUT IS SUFFERING FROM CONVECTIVE FEEDBACK. OVERALL KEPT THE
HIGHER CHANCE POPS FURTHER SOUTHWEST. ONLY MADE A SLIGHT ADJUSTMENT
ON MAXES BUT IF CLOUD COVER IS THICKER THAN EXPECTED WILL NEED TO
ADJUST DOWN.

TUESDAY THROUGH FRIDAY...DUE TO SHORT TERM CONCERNS/INCREASING
THUNDERSTORM COVERAGE WAS NOT ABLE TO SPEED A LOT OF TIME ON THIS
PERIOD. LINGERING CONVECTION WILL BE OVER THE AREA TUESDAY. MODELS
ARE DIFFERING FROM EACH OTHER IN HOW THEY HANDLE THE WESTERN
RIDGING AND HOW SHORTWAVE ENERGY COMES OVER THE TOP. GENERAL IDEA IS
A SERIES OF SHORTWAVE TROUGHS WILL BRING CONTINUED CHANCES FOR
THUNDERSTORMS THROUGH FRIDAY WITH WEDNESDAY AND THURSDAY HAVING THE
GREATEST COVERAGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 559 AM MDT SAT AUG 18 2012

VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. THUNDERSTORMS WILL
STAY TO THE SOUTH AND EAST OF KMCK. CURRENT AREA OF THUNDERSTORMS
WILL AFFECT KGLD FOR A COUPLE MORE HOURS BEFORE ENDING. AS SKIES
CLEAR AND SUBSIDENCE OCCURS BEHIND AREA OF STORMS...WINDS WILL
SHIFT TO THE NORTH AND BECOME GUSTY UNTIL EARLY EVENING BEFORE
BECOMING LIGHT AND VARIABLE.


&&

.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&

$$

UPDATE...024
SHORT TERM...BULLER
LONG TERM...BULLER
AVIATION...BULLER





AREA FORECAST DISCUSSION

NWS CARIBOU ME

 131 PM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WILL STALL ALONG THE MAINE COAST TODAY AND TONIGHT.
LOW PRESSURE WILL APPROACH FROM THE SOUTH LATER SUNDAY AND MONDAY.
&&

.NEAR TERM /THROUGH TONIGHT/...
UPDATE...CONTINUE TO TRIM BACK ON POPS/WX OVER DOWNEAST MAINE.
WHILE THE SHOWERS HAVE DISSIPATED OR MOVED OUT OF THE
AREA...ENOUGH INSTABILITY REMAINS OVER SOUTHEAST MAINE TO NOT RULE
OUT SCATTERED SHOWERS REDEVELOPING THIS AFTERNOON.

PREVIOUS DISCUSSION...
A COLD FRONT IS EXPECTED TO BECOME STATIONARY ALONG THE DOWNEAST
COAST TODAY. WITH UPPER LOW NEAR JAMES BAY AND 500MB FLOW PARALLEL
TO THE FRONT THIS SCENARIO LOOKS MOST REASONABLE. AT THE SAME TIME
SURFACE HIGH PRESSURE WILL BUILD IN FROM THE WEST LATER TODAY AND
TONIGHT. FOR POPS HAVE BEEN USING HRRR THEN MERGING IT WITH BLEND
OF THE NAM12...GFS40...SREF AND ECMWF. FOR QPF HAVE USED THE SAME
BLEND BUT WILL EXCHANGE NAM12 FOR NAM80. FOR WIND HAVE BLENDED
NAM12 AND GMOS AND WILL USE ONLY GMOS LATE TONIGHT. FOR
TEMPERATURE AND DEW POINT WILL USE GMOS WITH SOME MINOR
ADJUSTMENTS TO MAXIMUM TEMPERATURE.
&&

.SHORT TERM /SUNDAY THROUGH MONDAY/...
MAIN CHALLENGE WILL BE STALLED FRONTAL BOUNDARY ALONG THE COAST ON
SUNDAY AND WEAK LOW PRES WAVE MOVING UP ALONG THE FRONT.

DECIDED TO FOLLOW A BLEND OF THE ECMWF AND CANADIAN GLOBAL THIS
FCST CYCLE SHOWING AN AREA OF RAIN AFFECTING MAINLY THE COAST AND
OVER THE GULF OF MAINE WATERS FOR SUNDAY. THESE 2 NUMERICAL MODELS
WERE CONSISTENT W/THEIR PREVIOUS RUNS OF SHOWING THIS WAVE MOVING
UP ALONG THE FRONT. THE BOUNDARY WILL SERVE AS A CONVERGENCE AXIS
AND W/THE LOW, ENOUGH FORCING WILL BE THERE FOR A PERIOD OF RAIN
IN THE AFOREMENTIONED AREAS. THEREFORE, INCREASED THE RAIN PERCENTAGES
TO 50-60% ACROSS THE COAST AND OVER THE WATERS UP THROUGH 18Z AND
THEN DRY THINGS OUT AS THE FRONT SLIDES FURTHER SOUTH AND
EAST.THIS WILL ALSO HOLD DOWN TEMPERATURES OVER THE DOWNEAST AND
THE COAST(LOW/MID 70S). FURTHER NORTH AND WEST, DRIER CONDITIONS
AND HENCE WARMER TEMPERATURES(MID-UPPER 70S). QPF AMOUNTS WERE
ADJUSTED USING THE ECMWF AND CANADIAN GLOBAL W/AREAL ADJUSTMENTS.
THEREFORE, NOT EXPECTING MORE THAN .10" OF RAINFALL ALONG THE
IMMEDIATE COAST.

HIGH PRES IS SET TO RIDGE IN ACROSS THE CWA FROM THE SW SUNDAY
NIGHT INTO MONDAY. THIS SHOULD ALLOW FOR DRY CONDITIONS AND WARMER
TEMPERATURES. BROAD SWLY FLOW ALOFT WILL ALLOW FOR SOME CUMULUS TO
DEVELOP BY LATE MORNING. REMOVED THE MENTION OF RAIN SHOWERS FOR
MONDAY AND RAISED MAXES FROM THE PREVIOUS FORECAST UP A CATEGORY.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
BACKED AWAY FROM GMOS THROUGH WEDNESDAY AND BASICALLY STAYED
CLOSER TO THE ECMWF. THE ECMWF HAS BEEN CONSISTENT W/THE SYNOPTIC
PATTERN OF A  BROAD SW FLOW ALOFT W/CLOSED LOWER OVER HUDSON`S BAY.
THIS WILL ALLOW FOR A WAVE OF LOW PRES TO DEVELOP ON THAT STALLED
FRONTAL BOUNDARY JUST OFF THE MAINE COAST TO MOVE UP ALONG THE
FRONT ON TUESDAY. THE GFS APPEARED TO BE TOO STRONG AND AGGRESSIVE
W/THE LOW WHILE THE ECMWF AND CANADIAN GLOBAL KEEP THE LOW FURTHER
S AND E AND BOTH ARE NOT AS STRONG W/THE WAVE AND HAVE A SECOND
FRONT APPROACHING FROM CANADA BY TUESDAY AFTERNOON. DECIDED TO CUT
BACK ON PRECIP CHANCES TUESDAY W/THE LOW OFF THE COAST AND LEAN
W/A 20-30% CHANCE FOR SHOWERS IN THE AFTERNOON DUE TO THE COLD
FRONT MOVING IN FROM THE WEST. BOTH THE CANADIAN GLOBAL AND ECMWF
SUPPORT SOME SHOWER AS UPPER LEVEL SUPPORT IS THERE. TWEAKED
TEMPERATURES FOR TUESDAY TO BRING THEM UP A CATEGORY INTO THE
MID AND UPPER 70S. HIGH PRES AT THE SFC IS SHOWN TO MOVE ACROSS
THE REGION ON WEDNESDAY AND THE FRONT SLIDES TO THE EAST. THIS
WILL ALLOW FOR A DRY AND COMFORTABLE DAY. UPPER FLOW APPEARS TO
SHIFT A BIT TO A MORE WESTERLY COMPONENT ALLOWING FOR A DRIER SETUP.
OVERNIGHT TEMPERATURES MONDAY NIGHT AND AGAIN TUESDAY NIGHT LOOKED
TO NEED ADJUSTMENTS UPWARD USING A NAM12/GMOS BLEND. BROAD SW FLOW
ALOFT SEEMS TO FAVOR A WARM SCENARIO. DAY CREW CAN ASSESS THIS
FURTHER W/NEWER MODEL GUIDANCE.

THE UPPER TROF LOOKS LIKE IT WILL SHARPEN AGAIN BY LATE WEEK W/S
FRONTAL BOUNDARY APPROACHING. THERE IS THE POTENTIAL FOR SHOWERS
AND POSSIBLE TSTMS ON THURSDAY AND AGAIN FRIDAY AND THE FRONT WILL
BE SLOW TO MOVE ACROSS THE REGION. ATTM, STAYED CLOSER TO GMOS
W/30% POPS AND STAYED CLOSER TO THE TEMPERATURES SHOWING NEAR
NORMAL READINGS FOR LATE AUGUST.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: PREDOMINANTLY VFR CONDITIONS EXPECTED THROUGH TONIGHT.

SHORT TERM: POSSIBLE IFR/MVFR FOR THE COAST ON SUNDAY AND THEN
CONDITIONS IMPROVE TO VFR. IT LOOKS LIKE VFR FOR THE NORTHERN
TERMINALS THROUGH MONDAY. THERE DOES APPEAR TO BE SOME POTENTIAL
FOR MVFR AND POSSIBLY IFR CONDITIONS LATER MONDAY NIGHT INTO
TUESDAY MORNING W/A LIGHT ESE FLOW SETTING UP.

&&

.MARINE...
NEAR TERM: FOR WINDS HAVE USED A 50/50 BLEND OF THE NAM12 AND
GFS40 AND ADJUSTED BLEND DOWN 20 PERCENT DUE TO EXPECTED BOUNDARY
CONDITIONS. WILL USE NAM/SWAN TO INITIALIZE WAVE GRIDS. WILL
ADJUST WAVE MODEL DOWN 1 FOOT. PRIMARY WAVE GROUP IS WEAK
SOUTHERLY FETCH AROUND PERIPHERY OF HIGH OFF-SHORE. WAVE MODELS ARE
TOO HIGH WITH THIS WAVE GROUP. WNA SPECTRAL CONTINUES TO SHOW
BACKGROUND SOUTHEAST SWELL AT AROUND 1 FOOT. VERY LONG PERIOD
SWELL FROM ATLANTIC TROPICAL SYSTEMS MAY SHOW UP BUT NOT UNTIL
NEXT WEEK. WILL KEEP FOG ACROSS COASTAL WATERS WITH FRONT STALLED
ALONG COAST.


SHORT TERM: NO HEADLINES ANTICIPATED. A BLEND OF THE NAM12 AND
GFS40 WAS USED FOR THE WINDS INTO MONDAY WHICH SHOWS SUSTAINED
WINDS AT 10-15 KTS. AN ESE SWELL LOOKS POSSIBLE BY MONDAY AND
COULD CONTINUE THROUGH THE WEEK W/A LONG PERIOD. AS MENTIONED
IN THE NEAR TERM, WANAVE RUNNING TOO HIGH AND THEREFORE STAYED
W/THE CURRENT WAVE HEIGHTS OF 2-3 FT THROUGH THE PERIOD.

&&

.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.

&&

$$
NEAR TERM...MIGNONE/RUNYAN
SHORT TERM...HEWITT
LONG TERM...HEWITT
AVIATION...MIGNONE/RUNYAN
MARINE...MIGNONE/RUNYAN/HEWITT







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 341 PM EDT SAT AUG 18 2012

.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND COOLER WEATHER TO CONTINUE
THROUGH TONIGHT. A SERIES OF A WEAK UPPER LEVEL DISTURBANCES WILL
CROSS THE AREA THROUGH MONDAY, BRINGING A FEW ISOLATED SHOWERS TO
THE AREA.

&&

.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IS AT THE
BASE OF WEAK CYCLONIC MID-LEVEL FLOW THAT IS ON THE DISTANT
SOUTHERN PERIPHERY OF A VORTEX CENTERED OVER THE HUDSON BAY. DRY
AIR IS IN PLACE IN THE 750-400MB LAYER. THIS COUPLED WITH SURFACE
HIGH PRESSURE EXTENDING FROM THE MIDWEST INTO THE OHIO VALLEY HAS
YIELDED A DRY DAY ACROSS THE AREA.

THE SURFACE HIGH WILL SLOWLY SLIDE EASTWARD TODAY AND TONIGHT,
ALLOWING FOR DRY WEATHER TO CONTINUE. TEMP DIFFERENTIAL BTW 850MB
AND A WARMER LAKE ERIE WITH AN INITIAL NORTHWESTERLY FLOW WILL
ALLOW FOR PARTLY CLOUDY SKIES TO CONTINUE INTO THE EARLY EVENING.
CUMULUS WILL QUICKLY DIMINISH AFTER SUNSET. SOME THIN CIRRUS WILL
ADVECT ACROSS THE AREA TONIGHT. WITH NEAR CALM WINDS, SOME RADIATIONAL
COOLING WILL OCCUR TONIGHT DESPITE PASSING CIRRUS. LOWS ARE SLIGHTLY
COOLER THAN A MAV/MET BLEND, RANGING FROM THE MID 40S ACROSS THE
I-80 CORRIDOR TO THE LOWER 50S ACROSS THE LOWLANDS ELSEWHERE.

&&

.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
MODELS ARE IN AGREEMENT IN THE MID-LEVEL TROUGH ACROSS THE GREAT
LAKES AMPLIFYING WITH ITS AXIS CENTERED OVER LAKE MICHIGAN ON
SUNDAY. THERE IS SOME MODEL DISAGREEMENT IN REGARDS TO THE
INTENSITY OF VORT ENERGY SWINGING AROUND THE BOTTOM OF THE TROUGH
AND INTO THE UPPER OHIO VALLEY SUNDAY AFTERNOON. INCREASED MOISTURE
IN THE 850-700MB LAYER ALONG WITH STEEPENING LAPSE RATES WITH THE
POTENTIAL SHORT WAVE PASSAGE HAVE LED TO CHANCE POPS FORECAST WITH
SCHC THUNDER ON SUNDAY.

FOR TEMPS THROUGH SUNDAY NIGHT, AIR MASS IN PLACE WILL BE SIMILAR TO
THE PREVIOUS DAY WITH 850MB TEMPS IN THE 18-20C RANGE. THUS, HIGHS WILL
AGAIN RANGE FROM THE MID 70S ACROSS THE I-80 CORRIDOR AND EASTERN
RIDGES TO NEAR 80 IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV.
ANOTHER NIGHT OF RADIATIONAL COOLING IS ANTICIPATED WITH LOWS AROUND
5 DEGREES BELOW NORMAL.

MONDAY INTO TUESDAY...THE MID-LEVEL TROUGH WILL CROSS THE OHIO
VALLEY WITH SOME MODEL UNCERTAINTY IN HOW FAST ITS AXIS TRANSLATES
INTO PENNSYLVANIA. ECMWF IS MORE AMPLIFIED WITH THIS FEATURE THAN
THE GFS. WITH THIS IN MIND CHC POPS AND SCHC THUNDER ARE FORECAST
IN ADVANCE OF THE TROUGH MONDAY. DEEP LAYER MOISTURE BEGINS TO
ADVECT EAST OF THE AREA BY TUESDAY MORNING, AND THUS POPS ARE
LIMITED TO LOCATIONS EAST OF PITTSBURGH ON TUESDAY. TEMPS WILL
CONTINUE TO BE AROUND 5 DEGREES BELOW NORMAL THROUGH THIS PERIOD.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
CONSENSUS OF RECENT ECMWF AND NAEFS MODEL OUTPUT SHOW BROAD HIGH
PRESSURE ACROSS THE EASTERN U.S. WILL MAINTAIN DRY CONDITIONS
THROUGH FRIDAY IF NOT SATURDAY.

BLEND OF GFS MOS, ECMWF MOS, AND NAEFS MEDIAN VALUES SHOW
TEMPERATURES WEDNESDAY CAN STILL BE SLIGHTLY COOLER THAN NORMAL. AS
HIGH PRESSURE CENTER TRANSITIONS TO THE EAST COAST, DAYTIME HIGH
TEMPERATURES WILL BECOME SLIGHTLY WARMER THAN NORMAL THURSDAY INTO
WEEKEND.

BY SATURDAY, LOW LEVEL SOUTHERLY WINDS WILL TRANSPORT SURFACE DEW
POINTS OF 60 TO 65 INTO THE UPPER OHIO VALLEY. SO EARLY MORNING LOW
TEMPERATURES SHOULD RETURN TO NEAR NORMAL VALUES THIS WEEKEND.

CONCUR WITH HPC THINKING THAT THERE CAN BE AT LEAST A SLIGHT CHANCE
OF SHOWERS BY SUNDAY.

&&

.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR THROUGH EARLY
TONIGHT, AS GENERALLY NO MORE THAN SCATTERED DAYTIME CUMULUS
EXPECTED TO DEVELOP THIS AFTERNOON.

SURFACE WINDS WILL BE MAINLY FROM THE NORTHWEST INCREASING TO
MORE THAN 7 KTS BY AFTERNOON.

PER BLEND OF RECENT NAM MODEL PROFILES AND GFS LAMP, PATCHY  RIVER
VALLEY FOG MAY SPREAD MVFR VISIBILITIES TO SOME NEARBY TAF SITES
09Z-13Z.

AFTER THAT, MAINLY VFR DAYTIME SUNDAY, ALTHOUGH ISOLATED AFTERNOON
SHOWERS CAN DEVELOP.

.OUTLOOK/ SUNDAY NIGHT THROUGH THURSDAY/...
GENERALLY VFR. RESTRICTIONS MAY ACCOMPANY SCATTERED THUNDERSTORMS
MONDAY AFTERNOON AND EVENING AND PATCHY RIVER VALLEY FOG EACH
MORNING.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS PITTSBURGH PA

 142 PM EDT SAT AUG 18 2012

.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR DRY AND COOLER WEATHER TO CONTINUE
THROUGH TONIGHT. COOLER WEATHER WILL CONTINUE ON SUNDAY, ALTHOUGH
AN UPPER LEVEL DISTURBANCE MAY BRING A FEW ISOLATED SHOWERS TO THE
AREA.

&&

.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED WITH MINOR
ADJUSTMENTS TO ACCOUNT FOR THE LATEST TRENDS IN TEMP AND SKY
GRIDS.

THE LATEST RAP ANALYSIS INDICATES THE UPPER OHIO VALLEY IS AT THE
BASE OF WEAK CYCLONIC MID-LEVEL FLOW THAT IS ON THE DISTANT
SOUTHERN PERIPHERY OF A VORTEX CENTERED OVER THE HUDSON BAY. DRY
AIR IS IN PLACE IN THE 750-400MB LAYER. THIS COUPLED WITH SURFACE
HIGH PRESSURE EXTENDING FROM THE MIDWEST INTO THE OHIO VALLEY HAS
YIELDED A DRY DAY ACROSS THE AREA.

THE SURFACE HIGH WILL SLOWLY SLIDE EASTWARD TODAY AND TONIGHT,
ALLOWING FOR DRY WEATHER TO CONTINUE. TEMP DIFFERENTIAL BTW 850MB
AND A WARMER LAKE ERIE WITH AN INITIAL NORTHWESTERLY FLOW WILL
ALLOW FOR DIURNAL CUMULUS TO CONTINUE ACROSS MOST OF THE AREA WITH
PARTLY CLOUDY SKIES TODAY. DIURNAL CUMULUS WILL QUICKLY DIMINISH
AFTER SUNSET. SOME THIN CIRRUS WILL ADVECT ACROSS THE AREA
TONIGHT. WITH NEAR CALM WINDS, RADIATIONAL COOLING WILL OCCUR
TONIGHT. LOWS ARE SLIGHTLY COOLER THAN A MAV/MET BLEND, RANGING
FROM THE MID 40S ACROSS THE I-80 CORRIDOR TO THE LOWER 50S ACROSS
THE LOWLANDS ELSEWHERE.

&&

.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE UPPER OHIO VALLEY IS FORECAST TO REMAIN UNDER THE INFLUENCE OF
A JAMES BAY TO GULF COAST TROUGH THROUGH THE SHORT TERM PERIOD. ALTHOUGH
THE BOUNDARY LAYER MOISTURE FORECAST LOOKS RATHER LIMITED...STEEPENING
LAPSE RATES WITH A SHORTWAVE IN THE UPPER FLOW MAY SUPPORT SOME
ISOLATED TO SCATTERED SHOWERS ON SUNDAY. SLIGHT CHANCE POPS HAVE
THUS BEEN INTRODUCED...AND CONTINUED THROUGH MONDAY GIVEN THE
PRESENCE OF THE TROUGH AXIS PROJECTED TO LINGER OVER THE GREAT
LAKES AND OHIO VALLEY REGION. BY TUESDAY...THAT AXIS IS FORECAST
FAR ENOUGH EAST FOR A DRY FORECAST AS SURFACE HIGH PRES BUILD OVER
THE OHIO VALLEY. TEMPS UNDER THIS PATTERN ARE PROJECTED ABOUT 5
DEGREES UNDER THE AVERAGES USING TWEAKED SREF MEANS BLENDED WITH
THE LATEST MOS.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
WEAK SURFACE HIGH PRESSURE THAT IS FORECAST TO REMAIN OVER THE REGION
THROUGHOUT THE WEEK WILL SUPPORT SEASONAL TEMPERATURES AND
GENERALLY DRY CONDITIONS.

&&

.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
PER RECENT SURFACE AND SATELLITE DATA, EXPECT VFR THROUGH EARLY
TONIGHT, AS GENERALLY NO MORE THAN SCATTERED DAYTIME CUMULUS
EXPECTED TO DEVELOP THIS AFTERNOON.

SURFACE WINDS WILL BE MAINLY FROM THE NORTHWEST INCREASING TO
MORE THAN 7 KTS BY AFTERNOON.

PER BLEND OF RECENT NAM MODEL PROFILES AND GFS LAMP, PATCHY MVFR
RIVER VALLEY FOG MAY AFFECT SOME TAF SITES 10Z-13Z.

.OUTLOOK/ SUNDAY THROUGH WEDNESDAY/...
VFR.

&&

.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.

&&

$$







AREA FORECAST DISCUSSION

NWS BALTIMORE MD/WASHINGTON DC

 118 PM EDT SAT AUG 18 2012

.SYNOPSIS...
A COLD FRONT WHICH MOVED ACROSS THE AREA LAST NIGHT WILL STALL OUT
ACROSS SOUTHEAST VIRGINIA TODAY. THE BOUNDARY WILL RETURN NORTH
AS A WARM FRONT SUNDAY. A WAVE OF LOW PRESSURE MAY DEVELOP ALONG
THE BOUNDARY SUNDAY NIGHT INTO MONDAY. HIGH PRESSURE WILL SLOWLY
BUILD DURING THE MIDDLE PORTION OF THE WEEK.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT HAS PUSHED SOUTHEAST OF THE AREA THIS MORNING...AND IS
LIKELY TO STALL OUT ACROSS EXTREME SOUTHEAST VIRGINIA OR THE
NORTHEAST NORTH CAROLINA COAST THIS AFTERNOON.

NORTH/NORTHWEST WINDS HAVE BROUGHT SOME DRIER AIR BOTH AT THE
SURFACE AND ALOFT ACROSS THE AREA. BUT WITH SOME COOLING ALOFT
ATOP THE WARM GROUND...EXPECT AT LEAST SCATTERED CUMULUS TO DOT
THE SKY THIS AFTERNOON.

MORE CLOUDS MAY BE FOUND ACROSS SOUTHERN MARYLAND AND THE LOWER
CHESAPEAKE BAY AREA CLOSER TO THE FRONT AND ALSO WITHIN THE UPPER
JET FLOW. THIS IS ALSO AN AREA WHERE ISOLATED SHOWERS MAY DEVELOP THIS
AFTERNOON PER THE WRF-ARW. HRRR IMPLIES THERE MAY BE SHOWERS
FURTHER NORTH AND WEST...BUT GIVEN DRYING AND WEAK FORCING HAVE
KEPT REST OF THE CWA DRY. MAXIMA ARE FORECAST TO BE SLIGHTLY BELOW
CLIMO.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
LIGHT NELY/ELY FLOW DEVELOPS WITH ISOLATED CHANCE FOR SHOWERS
EXPANDING WEST TO THE BLUE RIDGE. PLENTY OF CLOUDS WITH MIN TEMPS
MID TO UPR 50S PIEDMONT AND WEST...LOW TO MID 60S I-95 AND EAST.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
THIS XTND FCST IS "A STORY OF THE DIFFERENCES IN THE MDL POSNS OF
LAST NGT AND TNGT." LAST NGT NAM HAD A CLOSED SFC LOW OVR THE MID
ATLC SUNDAY WHILE THE GFS DVLPD IT OFFSHORE. TNGT THE CHG IS
FOCUSED ON SUN NGT/MON. GFS HAS CHGD TO HV THE SFC LOW DVLP UNDER
THE UPR TROF - FORMING IN THE TN VLLY SUN NGT AND MOVG OVR THE
DELMARVA MON EVE. THE NAM FORMS THE LOW OFF THE CST...SO
ESSENTIALLY A "180" FM THE PRVS NGT. THIS IN TURN GIVES CAT POPS
TO THE ENTIRE CWA FOR MON FM THE GFS...WHILE THE NAM RANGES FM LKLY
AT BALT TO NOTHING AT SHD.

I MUST SAY - LAST NGT I WAS VERY SUSPICIOUS WHEN THE NAM WENT SO
AGGRESSIVE W/ POPS...BUT AM LESS SO W/ THE NEW GFS APPROACH. LAST
YR I DID A STUDY ON GFS PERFORMANCE DURG THE SUMMER MONTHS AT THE
3 MAJOR AIRPORTS. FM 2009-11...DURG THE SUMMER...WHEN THE GFS
FCSTD 80 POP IN PD 5 - IN THIS CASE THAT`D BE MON...MEASURABLE
PCPN OCCURRED 14 OUT OF 14 TIMES. HIGH POPS CAN BE HARD TO JUSTIFY
IN SUMMER DUE TO THE "HIT OR MISS" NATURE OF CNVCTN...BUT IT`S
HARD TO ARGUE W/ THOSE NUMBERS...ESPECIALLY WHEN WE`RE NOT TALKING
ABT A CD FNT APRCHG FM THE NW.

ECM IS COMING IN AS I WRITE AT 315 AM. ITS SFC LOW IS NOT AS
TIGHT AS THE GFS DEPICTION BUT IT TOO HAS THE INCRSD RH IN THE E.
21Z SREF ALSO HAD A 50% CHC OF .05" FOR MON IN THE E.

SO FOR NOW HV INCRSD THE POPS FOR MON E OF THE MTNS FM CHC TO
LKLY...W/ HIGHEST NUMBERS ALONG THE BAY. IF THE SYNOPTIC PATTERN
PLAYS OUT LK I`M BEGINING TO THINK IT WL PCPN MOST LKLY WL BE RW
W/ EMBEDDED T PSBL. AM NOT THINKING A SVR OUTBRK GIVEN ERLY FLOW
AND DEEP CLD CVR. THE PCPN WOULD MOST LKLY BE EXITING THE AREA DURG MON
AFTN...SO FLDG NOT A CONCERN.

AFTR MON HIGH PRES LOOKS TO BLD IN FOR TUE-FRI. TEMPWISE THE WK
AHD SHOULD BE QUITE PLSNT W/ DAYS W/ HIGHS IN THE LM80S AND NGTS
RANGING FM THE M50S IN THE MTNS TO L70S ON THE CHES BAY. FM I-81
TO I-95 WL DROP INTO THE 60S.

&&

.AVIATION /17Z SATURDAY THROUGH WEDNESDAY/...
VFR TODAY WITH FRONT STALLING OUT OVER FAR SOUTHEAST VIRGINIA.
EXPECT SHOWERS TO REMAIN SOUTHEAST OF THE TERMINALS. N/NW WINDS
MAY BE 10 TO 15 KT AT TIMES DURING THE AFTERNOON.

CIGS MAY DROP INTO MVFR CAT SUN NGT AND MON AS LOW PRES TRACKS
ACROSS THE ERN PORTION OF THE FCST AREA. ISOLD TSTMS WOULD BE
PSBL. HIGH PRES TO BUILD IN TUE THRU THU.

&&

.MARINE...
NORTHERLY WINDS HAVE BEEN DIMINISHING OVER THE LAST COUPLE OF
HOURS AND THE LATEST COVM2 OB DROPPED TO 17 KT. TREND SHOULD
CONTINUE AND THUS SCA WILL BE CANCELLED. EXPECT 10 TO 15 KT FOR
THE REST OF THE AFTERNOON.

THERE IS SOME DIFFERENCE IN THE MDLS REGARDING THE DVLPMNT OF A
LOW PRES AREA TO OUR SW SUN MOVG INTO THE WATERS MON. IF THIS DOES
COMES TRUE MON MAY BE WETTER THAN PRVSLY THOT. THERE MAY ALSO BE A
PD OF SCA-LVL WINDS.

HIGH PRES LOOKS TO MOVE INTO THE MID ATLC TUE-FRI.

&&

.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...NONE.

&&

$$
BPP/BAJ/WOODY!








AREA FORECAST DISCUSSION

NWS MARQUETTE MI

 401 PM EDT SAT AUG 18 2012

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 359 PM EDT SAT AUG 18 2012

12Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP UPR TROF OVER
ERN NAMERICA CENTERED AROUND CUTOFF UPR LO NEAR JAMES BAY. THERE ARE
SEVERAL SHRTWVS ROTATING THRU THE TROF AND ARND THIS FEATURE. THE
FIRST IS SETTLING S THRU ONTARIO WHILE ANOTHER NEAR LK WINNIPEG IS
DIVING SSEWD TOWARD NW MN. AT 15Z...THESE SHRTWVS/ACCOMPANYING SFC
TROF OVER LK SUP WITH SHARP WSHFT WERE SUPPORTING A BKN LINE OF SHRA
EXTENDING FM ERN LK SUP ACRS THE KEWEENAW THRU NRN MN TOWARD LK
WINNIPEG. THE 12Z INL RAOB SHOWS ABUNDANT MID LVL MSTR ABV A DRIER
SUB H75 LYR...AND THIS LOWER LVL DRY AIR SEEMS TO BE THE BIGGEST
IMPEDIMENT TO MORE WDSPRD SHRA. THE DRY AIR IS DEEPER TO THE S AS
INDICATED BY THE 12Z GRB RAOB...AND THE MRNG WAS MOSUNNY OVER THE
SCNTRL. TO THE N...MUCH DRIER LLVL AIR IS PRESENT ON THE 12Z YPL
RAOB UNDER HI PRES RDG AXIS EXTENDING SEWD INTO NW ONTARIO FM HI
PRES CENTERED OVER NRN MANITOBA. MODIFIED

LATE THIS AFTN...WITH ARRIVAL OF SFC TROF/ENHANCED LLVL CNVGC
ASSOCIATED WITH SHARP SYNOPTIC WSHFT THAT WL BE ENHANCED BY
BREEZE OFF LK SUP DURING PEAK HEATING TIME...THE SHRA HAVE BECOME
MORE NMRS WITH SOME EMBEDDED TS ON A LINE THRU THE CNTRL ZNS.
MODIFIED 12Z INL RAOB FOR SFC T/TD OF 75/47 YIELDS SBCAPE UP TO 600
J/KG. ALTHOUGH SHRA COVERAGE IS STILL LIMITED OVER THE SCNTRL BY
LINGERING LLVL DRY AIR...EXPECT THESE SHRA TO SPREAD INTO THAT AREA
AS THE DRY AIR RETREATS. THE INTENSITY OF THE TS WL BE LIMITED BY
DRY LLVL AIR...ENVIRONMENTAL LAPSE RATES NOT FAR FM MOIST
ADIABATIC/DEEP SKINNY CAPE...LACK OF MID LVL DRY AIR THAT KEEPS
SFC-10K FT DELTA THETA-E NO HIER THAN 5-10C...AND RELATIVELY WEAK
DEEP LYR SHEAR NO GREATER THAN 15-25 KTS. ALTHOUGH SOME STORMS HAVE
PULSED AT TIMES...THE SMALL CORES HAVE NOT PERSISTED AND REMAINED
NEARLY VERTICAL...CONSISTENT WITH A WEAK SHEAR ENVIRONMENT. LO FRZG
LVL NOT FAR FM 9K FT AGL INDICATES THE STRONGER CELLS MIGHT DROP
SOME SMALL HAIL.

TONIGHT...MAIN FCST CONCERNS BECOME HOW QUICKLY DRIER AIR OVER
ONTARIO CAN MOVE INTO THE UPR LKS AND COUNTER LINGERING DYNAMIC
SUPPORT ASSOCIATED WITH DISTURBANCE NOW NEAR LK WINNIPEG THAT IS
FCST TO DROP SEWD INTO NW WI BY 12Z SUN AND SHARPEN UPR TROF AXIS
EXTENDING FM CLOSED LO NEAR JAMES BAY SWWD THRU UPR MI. LOSS OF
DAYTIME HEATING WL ALSO ENHANCE SHRA DISSIPATION. THE NAM IS MOST
AGGRESSIVE WITH UPR DRYING AND SHOWS ANY LINGERING -SHRA OVER THE
SCNTRL ENDING BY 03Z. THE BULK OF THE OTHER GUIDANCE MAINTAINS THE
-SHRA MAINLY OVER THE SCNTRL THRU MUCH OF THE NGT. HOWEVER...
CONSIDERING THE LLVL DRYNESS OF THE 12Z YPL RAOB AND RATHER
AGGRESSIVE DRYING TAKING PLACE OVER THE N PORTIONS OF LK SUP/
ADJOINING ONTARIO...THE NAM MIGHT BE ON THE RIGHT TRACK. SINCE ALL
THE MODELS ALSO SHOW LIMITED DEEP LYR QVECTOR CVNGC AS ANY DPVA
AHEAD OF SHRTWV IS OFFSET BY DRYING...TENDED TO CUT POPS A BIT
FASTER THAN GOING FCST WITH SMALL CHC POPS LINGERING ONLY OVER THE
FAR SCNTRL NEAR MNM LATER TNGT. ALTHOUGH LGT WINDS ASSOCIATED WITH
BLDG HI PRES MOVING TOWARD WRN UPR MI TOWARD 12Z/AGGRESSIVE MID LVL
DRYING MIGHT SUPPORT FOG FORMATION ESPECIALLY IN AREAS THAT GET RA
THIS AFTN/EVNG...WL KEEP FOG OUT OF FCST EXCEPT FOR OVER THE
INTERIOR WCNTRL...WHERE THE GFS HINTS THE LLVL DRYING WL BE LESS
PRONOUNCED AND SREF PROB VSBY UNDER 1 MILE IS HIER AND WHERE MIN
TEMPS ARE LIKELY TO BE LOWEST ARND 40.

SUN...CWA IS FCST TO REMAIN UNDER UPR TROF EXTENDING SWWD FM HUDSON
BAY. THE 12Z NAM/LOCAL WRF-ARW SHOW A SFC RDG AXIS EXTENDING FM WRN
LK SUP THRU THE CWA BRINGING A DRY DAY. THE 12Z GFS/CNDN MODELS ON
OTHER HAND SHOW A WEAKER SFC RDG...WITH A WEAKER GRADIENT ALLOWING
SOME LK BREEZE CNVGC/WEAK LO PRES TROF OVER THE SCNTRL...WHERE THESE
MODELS GENERATES SOME INSTABILITY -SHRA IN THE AFTN. CONSIDERING THE
WARM/DRY H7-5 LYR/LO FCST KINX ARND 18 BY THE GFS IN THIS AREA...
OPTED TO MAINTAIN GOING DRY FCST. WITH H85 TEMPS FCST TO BE ARND 8C
AND MIXING TO H75 ON GFS FCST SDNGS...EXPECT HI TEMPS TO REACH THE
MID 70S NEAR THE WI BORDER/SCNTRL AWAY FM LK MODERATION.

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 359 PM EDT SAT AUG 18 2012

UPPER-LEVEL CONDITIONS WILL REMAIN SUPPORTIVE OF A SUBTLE SERIES OF
TROUGHS AND RIDGES THROUGH MONDAY. DRY CONDITIONS WILL THEN BUILD IN
FOR THE MIDDLE OF THE WEEK BEFORE A WARM...AND POTENTIALLY WET...END
TO THE WEEK.

SUNDAY NIGHT AND MONDAY...NAM/GFS/ECMWF/GEM HAVE COME INTO GOOD
AGREEMENT ON THE SYNOPTIC PATTERN ACROSS CENTRAL AND EASTERN NORTH
AMERICA THROUGH TUESDAY...SO OVERALL CONFIDENCE OF THE FORECAST IN
THIS TIME PERIOD IS FAIRLY GOOD.

A PERSISTENT MID-LEVEL LOW OVER JAMES BAY WILL BEGIN TO MOVE
NORTHEAST SUNDAY NIGHT AS A BROAD MID-LEVEL RIDGE OVER THE WESTERN
THIRD OF THE CONUS COMMENCES DEAMPLIFICATION WHILE DRIFTING EASTWARD
TOWARD THE UPPER GREAT LAKES REGION. A SERIES OF SHORTWAVE TROUGHS
WILL CONTINUE TO TRACK AROUND THE BACKSIDE OF THE LOW OVER JAMES
BAY. THE FIRST OF THOSE IS MOVING THROUGH THE AREA TODAY. THEN...A
SECOND TROUGH BEHIND TODAYS TROUGH WILL CROSS THE AREA ON
SUNDAY...AND BE EXITING TO THE SOUTHEAST OUT OF UPPER MI BY SUNDAY
EVENING. A SHORTWAVE RIDGE WILL THEN BRIEFLY MOVE IN SUNDAY EVENING
AHEAD OF YET ANOTHER WEAK SHORTWAVE TROUGH CROSSING THE CWA ON
MONDAY.

THE WEAK INCOMING RIDGE COMBINED WITH PLENTY OF DRY AIR THROUGHOUT
THE COLUMN SHOULD LIMIT THE CHANCE OF ANY PRECIP BY SUNDAY EVENING.
ATTENTION IS PLACED MOSTLY ON THE POTENTIAL OF TEMPERATURES NEARING
FROST CRITERIA/ 36F/ INTERIOR WEST SUNDAY NIGHT. DIFFICULTY OF
PINNING DOWN EXACT LOW TEMPS RESIDES WITH WINDS AND THE CLOUD COVER
PATTERN BETWEEN THE TROUGH ON MONDAY AND THE ONE ON TUESDAY.
FIRST...DRY AIR AND SUBSIDENCE WILL ERODE REMAINING CLOUDS FROM
SUNDAYS SHORTWAVE. SEVERAL MODELS ARE SHOWING AN ENHANCED LAYER OF
MOISTURE BETWEEN 800 AND 700MB MOVING INTO THE AREA LATE SUNDAY
NIGHT. THIS IS LIKELY RESIDUAL MOISTURE FROM DIURNAL CUMULUS ON
SUNDAY...AS IS NOTED WITH THE UPSTREAM SATELLITE IMAGES IN NORTHERN
MANITOBA...SO DO NOT THINK LOW CLOUDS WILL BE A FACTOR. AIR ABOVE
THE MID-LEVELS WILL BE QUITE DRY...WHICH IS ALSO NOTED ON IR/VIS
SATELLITE IMAGES FROM UPSTREAM. BEHIND A WEAK SFC RIDGE SUNDAY
EVENING...WINDS MAY END UP BEING THE LIMITING FACTOR AS THE PRESSURE
GRADIENT INCREASES WITH HIGH PRESSURE UNDER THE WESTERN RIDGE
BUILDING INTO THE REGION. THE LOW-LEVELS SHOULD BE ABLE TO DECOUPLE
ENOUGH...ESPECIALLY IN THE TYPICAL COLD SPOTS. ULTIMATELY...WILL
KEEP ONGOING FORECAST OF MID TO UPPER 30S WELL INLAND...AND LEAVE
PATCHY FROST OUT OF THE FORECAST FOR RIGHT NOW.

THE THIRD SHORTWAVE TROUGH IS PROGGED TO MOVE ACROSS THE CWA
THROUGHOUT THE DAY ON MONDAY. NOT MUCH IN THE WAY OF MOISTURE WITH
THIS SHORTWAVE EITHER. HOWEVER...AS THE INFLUENCE FROM THE TROUGH
APPROACHES THE SOUTH CENTRAL CWA...H8 WAA/MOISTURE TRANSPORT MAY
ASSIST WITH KICKING OFF SOME ISOLATED SHOWERS. LOW-LEVEL DRY AIR MAY
INHIBIT SHOWERS SOMEWHAT...SO WILL ONLY PUT A SLIGHT CHANCE IN THE
FORECAST FOR THE SOUTH-CENTRAL CWA. H8 TEMPS AROUND 7-8C SHOULD
YIELD HIGHS AROUND 70 FOR MOST LOCATIONS.

MONDAY NIGHT AND TUESDAY...THE DE-AMPLIFYING RIDGE FROM THE WESTERN
STATES WILL MOVE OVER UPPER MI MONDAY NIGHT...LEADING TO MOSTLY
CLEAR SKIES AND ANOTHER ROUND OF GOOD RADIATIONAL COOLING. THIS
TIME...DEW POINTS WILL BE MUCH HIGHER...SO MOST INLAND LOCATIONS
SHOULD STAY ABOVE 40. SUBSIDENCE FROM THE RIDGE WILL KEEP CONDITIONS
DRY THROUGH TUESDAY. H8 TEMPS FROM 10-12C WOULD RESULT IN MID 70S
FOR HIGHS ACROSS MOST OF THE CWA ON TUESDAY...WITH SLIGHTLY COOLER
TEMPS EAST IN REGIONS AFFECTED BY LAKE BREEZES FROM LAKES MICHIGAN
AND SUPERIOR.

TUESDAY NIGHT THROUGH SATURDAY...THE REMNANTS OF THE LOW CURRENTLY
OVER JAMES BAY WILL BE IN FAR NORTHERN QUEBEC BY TUESDAY NIGHT. A
SHORTWAVE TROUGH ROTATING AROUND THE BACK OF THE LOW IS PROGGED
TO MOVE THROUGH NORTHERN ONTARIO TUESDAY NIGHT INTO WEDNESDAY. THE
ECMWF HAS BEEN TRENDING FARTHER NORTH WITH THIS SYSTEM. MEANWHILE
THE GFS HAS BECOME THE MORE SOUTHERN SOLUTION. PREFER THE TREND OF
THE ECMWF AS THE WAVE WILL BE ATTEMPTING TO DIG INTO THE EASTERN
EDGE OF A NOW BUILDING WESTERN RIDGE. EXPECTATION IS THAT PRECIP
WILL STAY OUT OF THE AREA UNTIL LATE WEDNESDAY AS AN ASSOCIATED SFC
COLD FRONT STALLS OVER LAKE SUPERIOR...THOUGH THE FINAL LOCATION OF
THIS FEATURE IS STILL A LITTLE INCONSISTENT IN THE MODELS.

DRY AIR ABOVE THE LOWEST FEW KFT WILL ALLOW FOR DECENT MIXING ON
BOTH TUESDAY AND WEDNESDAY. LOWERED DAYTIME DEW POINTS ABOUT 5F FROM
PREVIOUS FORECAST FOR BOTH DAYS. THIS RESULTS IN MIN RH VALUES
AROUND 40 PERCENT BOTH DAYS. HOWEVER...FEELING IS THAT THE TREND
WILL BE TOWARD LOWER RH VALUES WITH PROCEEDING FORECASTS.

A DEEP TROUGH MOVING ONTO THE WEST COAST TUESDAY WILL THEN REACH THE
UPPER MS VALLEY BY LATE FRIDAY. THE INDUCED SFC LOW IS EXPECTED TO
BRING THE STALLED SFC BOUNDARY BACK NORTHWARD AS A WARM FRONT. HIGH
TEMPS DURING THIS TIME WILL LIKELY BE ABOVE NORMAL /AROUND 80/ DUE
TO SOUTHERLY FLOW SOUTH OF THE STALLED BOUNDARY...BUT AS NOTED
BEFORE...UNCERTAINTY STILL EXISTS IN THE FINAL LOCATION OF THE
BOUNDARY. WILL STICK WITH CONSENSUS OF MODEL THROUGHOUT THIS TIME
FRAME GIVEN DECENT AGREEMENT FOR THIS FAR OUT.
&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 123 PM EDT SAT AUG 18 2012

INCOMING UPR DISTURBANCE/LO PRES TROF WL BRING THE THREAT OF -SHRA
AND PERHAPS A TS TO THE 3 SITES THIS AFTN...ESPECIALLY SAW. INCLUDED
EXPLICIT MENTION OF TS FOR A FEW HRS THIS AFTN ONLY AT SAW...WHERE
LESS EXPOSURE TO MODERATION OFF LK SUP AND LLVL CNVGC WL BE MOST
PRONOUNCED AND ABLE TO TAKE ADVANTAGE OF MARGINAL INSTABILITY. SINCE
THE LLVLS ARE SO DRY...VFR CONDITIONS SHOULD PREDOMINATE. THE SHRA
THREAT WL END EVERYWHERE BY 00Z WITH THE ARRIVAL OF DRIER AIR/ARPCH
OF SFC HI PRES. SOME FOG IS POSSIBLE LATE TNGT AT IWD...WHERE THE
LLVL DRYING WL BE LESS AGRESSIVE. AFTER ANY FOG BURNS OFF SOON AFTER
SUNRISE...SUN SHOULD FEATURE VFR CONDITIONS WITH LLVL ACYC FLOW
ASSOCIATED WITH HI PRES BLDG INTO THE AREA.
&&

.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 359 PM EDT SAT AUG 18 2012

A GENERALLY WEAK PRES GRADIENT DOMINATING THE UPPER GREAT LAKES WILL
RESULT IN WINDS MOSTLY UNDER 20KT THRU THU. THE PRES GRADIENT WILL
BECOME A BIT SHARPER TUE NIGHT AS A LO PRES TROF MOVES ACROSS
CENTRAL ONTARIO...RESULTING IN WSW WINDS UP TO 25 KTS OVER PORTIONS
OF THE W AND NORTH CENTRAL.
&&

.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&

$$

SHORT TERM...KC
LONG TERM...TK
AVIATION...KC
MARINE...KC







AREA FORECAST DISCUSSION

NWS GRAND RAPIDS MI

 344 PM EDT SAT AUG 18 2012

.SYNOPSIS...
ISSUED AT 342 PM EDT SAT AUG 18 2012

A DEPARTING HIGH PRESSURE SYSTEM SHOULD CLEAR THE SKIES EARLY
TONIGHT. HOWEVER A COLD FRONT MOVING SOUTH THROUGH THE AREA SUNDAY
WILL BRING SOME SHOWERS AND ISOLATED THUNDERSTORMS TO NORTHERN
SECTIONS AFTER MIDNIGHT. AS THE FRONT MOVES THROUGH THE AREA
SUNDAY EXPECT SHOWERS AND ISOLATED THUNDERSTORMS. TEMPERATURES
WILL REMAIN BELOW NORMAL INTO TUESDAY BEFORE A SLOW WARMING TREND
SETS IN THAT WILL LAST NEXT WEEKEND.

&&

.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 342 PM EDT SAT AUG 18 2012

THE PRIMARY ISSUE WITH THIS FORECAST IS CONVECTION AND THE
POTENTIAL FOR SHOWERS AND THUNDERSTORMS INTO MONDAY.

A WEAK CONVERGENCE BOUNDARY FROM NEAR MKG TO MBS THIS AFTERNOON IS
INTERACTING WITH THE LAKE BREEZE AND A WEAK MID LEVEL SHORTWAVE TO
CAUSE A CLUSTER OF SHOWERS AND ISOLATED THUNDERSTORMS THAT
CONTINUES TO MOVE EAST FROM NEWAYGO COUNTY INTO MONTCALM COUNTY.
THIS ACTIVITY IS MOVING VERY SLOWLY... ONLY 10 MPH AND SHOULD
DISSIPATE BY SUNSET OVER GRATIOT AND ISABELLA COUNTIES. AREAS NEAR
AND SOUTH OF INTERSTATE 96 SHOULD STAY DRY. DUE TO THE DRY SUB
CLOUD LAYER EXPECT SOME GUSTY WINDS WITH THE STORMS. WE HAVE SEEN
GUSTS TO AROUND 20 MPH SO FAR. A MESO-NET IN THE CITY OF NEWYGO HAD
A QUARTER INCH OF RAIN FROM THE STORMS THIS AFTERNOON SO FAR.

AS THE COLD FRONT DROPS SOUTH OVERNIGHT INTO SUNDAY THE SURFACE
PRESSURE GRADIENT IS WEAK. WITH THE SURFACE WATERS OF LAKE
MICHIGAN NEAR 22C AND AIR TEMPS EXPECTED TO FALL INTO THE 50S
INLAND AN LAND BREEZE WILL ONCE AGAIN SET UP. WITH THAT AND THE
FRONT MOVING SOUTH THE NAM12 SHOWS A MESO LOW FORMING THIS EVENING
NEAR TVC THE MOVING SOUTH TO LITTLE SABLE POINT BY MID MORNING
SUNDAY. THIS SHOULD FOCUS INSTABILITY NEAR THE LAKE SHORE AS IT
MOVES SOUTH OVERNIGHT. THERE IS ENOUGH INSTABILITY FOR
THUNDERSTORMS BASED ON BOTH RAP AND NAM SOUNDINGS. SO I INCREASED
POPS NORTH TONIGHT.

THIS BOUNDARY WILL SLOWLY MOVE SOUTH SUNDAY INTO SUNDAY EVENING.
THERE IS INSTABILITY BUT MARGINAL MOISTURE. EVEN SO GIVEN THE
CONVECTION THAT OCCURRED TODAY I BELIEVE SHOWERS ARE LIKELY NORTH
OF INTERSTATE 96 SUNDAY. WITH THE DRY SUB CLOUD LAYER EXPECT
GUSTY WINDS WITH THE SHOWERS AND THUNDERSTORMS. WITH THE COLD AIR
ALOFT EXPECT SMALL HAIL WITH THE STRONGER STORM TOO.

ONCE THE DRIER AIR BEHIND THE FRONT MOVES IN SUNDAY NIGHT SKIES
SHOULD CLEAR FROM NORTH TO SOUTH. WINDS WILL ONCE AGAIN BE LIGHT
SO ANOTHER LAKE BREEZE CONVERGENCE BAND OVER LAKE MICHIGAN IS
LIKELY TO FORM (SOUNDING REALLY SUPPORT THIS).

THERE IS STILL ENOUGH INSTABILITY WITH THE COLD AIR ALOFT FOR
AFTERNOON SHOWERS AND ISOLATED THUNDERSTORMS MONDAY. HOWEVER THE
MOISTURE IS ANEMIC. SO I WENT WITH ISOLATED SHOWERS /THUNDERSTORMS
FOR NOW.



.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 342 PM EDT SAT AUG 18 2012

WILL LEAVE TUESDAY DRY...BUT CAN NOT COMPLETELY RULE OUT A SHOWER AS
A SHORT WAVE CLEARS THE CWA.  BEYOND THAT THE MID WEEK PERIOD LOOKS
QUIET AND PLEASANT AS LARGE HIGH PRESSURE SLIDES IN.  THE HIGH
BECOMES BLOCKED BY AN UPPER LOW OVER THE CANADIAN MARITIME...SO
COMFORTABLE WEATHER SHOULD PREVAIL FOR A FEW DAYS.  THE RIDGE
FINALLY MOVES EAST LATE IN THE WEEK WHICH ALLOWS A NORTHERN STREAM
SHORT WAVE TO APPROACH.  WILL START POPS FRIDAY NIGHT IN THE WEST...
THEN SPREAD OVER ENTIRE CWA SATURDAY.

AS FOR TEMPS...WE SHOULD SEE A SLIGHT MODERATING TREND...BUT STAYING
NEAR NORMAL MUCH OF THE TIME.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 109 PM EDT SAT AUG 18 2012

VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING HOURS. SOME
PATCHY FOG WILL DEVELOP TOWARD DAYBREAK SUNDAY. THERE COULD BE
SOME IFR CONDITIONS...BUT THIS SHOULD NOT LAST LONG...NO MORE THAN
A COUPLE HOURS AT ANY ONE LOCATION.

AN ISOLATED THUNDERSTORM OR TWO MAY BE POSSIBLE AFTER 15Z SUNDAY
ALONG AND NORTH OF I-96. HAVE NOT MENTION THESE IN THE TAFS
HOWEVER DUE TO THEIR ISOLATED NATURE.


&&

.MARINE...
ISSUED AT 342 PM EDT SAT AUG 18 2012

WINDS WILL FOR THE MOST PART BE LESS THAN 15 KNOTS THROUGH MONDAY.
THUS I SEE NO NEED FOR A SMALL CRAFT ADVISORY AT THIS TIME. EVEN
SO THERE IS UNSEASONABLY COOL AIR IN PLACE AND LAKE MICHIGAN IS
STILL WARM RELATIVE TO THE AIR OVER IT... SO WITH THE CONVECTION
EXPECTED LATER TONIGHT AND SUNDAY EXPECT ISOLATED WATER SPOUTS
WITH THE STRONG SHOWERS AND THUNDERSTORMS. I ADDED THEM TO THE
GRIDS INTO SUNDAY AFTERNOON.

&&

.HYDROLOGY...
ISSUED AT 342 PM EDT SAT AUG 18 2012

WHILE THERE WILL BE SHOWERS AROUND INTO MONDAY I DO NOT EXPECT ANY
WIDESPREAD HEAVY RAINFALL. THUS NO BIG HYDRO ISSUES ARE FORESEEN AT
THIS TIME.

&&

.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&

$$

SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...JK
AVIATION...JK
HYDROLOGY...WDM
MARINE...WDM







AREA FORECAST DISCUSSION

NWS OMAHA/VALLEY NE

 316 PM CDT SAT AUG 18 2012

.DISCUSSION...

SCATTERED SHOWERS CONTINUE TO SLIDE SOUTHEAST AS FORCING FOR
ASCENT FROM A MID LEVEL SHORTWAVE CONTINUES TO MOVE SOUTHEAST THRU
THE FORECAST AREA. THERE IS ANOTHER AREA OF SHOWERS IN A BAND TO
THE NORTHEAST OF THE CWA WHICH SEEMS TO LINE UP WELL WITH A NARROW
BAND OF MID LEVEL FRONTOGENESIS ON NOSE OF THETA-E AXIS. THIS
IS FORECAST TO CONTINUE SOUTHEAST THRU THE LATE AFTERNOON AND
EVENING HOURS SO WL CONTINUE TO INCLUDE A SMALL MENTION OF POPS IN
OUR EASTERN COUNTIES FOR THIS ACTIVITY AS WELL. IN
ADDITION...THERE IS A POTENTIAL FOR FOG DEVELOPMENT OVERNIGHT WITH
CLEARING SKIES. SFC WIND BECOMES LIGHT AND VARIABLE AS HIGH
PRESSURE MOVES OVER AREAS THAT SAW SOME PRECIPITATION TODAY.
LATEST HRRR ALSO SHOWING AREA OF REDUCED VISIBILITIES...ESPECIALLY
IN OUR NORTH SO WL GO AHEAD AND MENTION SOME PATCHY FOG OVERNIGHT.
EXPECTING LOWS TO FALL INTO THE UPPER 40S TO LOWER 50S WHICH
WILL BE CLOSE BUT SLIGHTLY ABOVE RECORDS.

SUNDAY CONTINUES TO LOOK MOSTLY DRY AS HIGH PRESSURE SLIDES EAST OF
THE AREA. MODELS CONTINUE TO INDICATE SOME LIGHT QPF IN OUR EASTERN
COUNTIES ASSOCIATED WITH EXITING UPPER LEVEL SHORTWAVE ENERGY. MAY
HAVE SOME ISOLATED SHOWERS OVER IOWA COUNTIES IN THE AFTERNOON
ONCE CU FIELD DEVELOPS. WILL THROW IN A SLIGHT CHANCE POP IN OUR
FAR NERN COUNTIES FOR SUNDAY AFTERNOON AND MENTION ISOLATED
THUNDER AS SOME INSTABILITY IS PRESENT.

AREA REMAINS IN NORTHWESTERLY FLOW FOR EARLY IN THE SCHOOL/WORK
WEEK. THE WEATHER SHOULD REMAIN FAIRLY QUIET WITH WARM SOUTHERLY
FLOW BRINGING A SLIGHT INCREASE IN LOW LEVEL MOISTURE TO THE
AREA.

IN THE EXTENDED...MID LEVEL FLOW WILL BECOME MORE ZONAL BY MID
WEEK AS WEAKENING UPPER LEVEL RIDGE FLATTENS OVER THE NATIONS MID
SECTION. A POTENT SHORTWAVE MOVING INTO THE NORTHERN PLAINS BY
LATE IN THE WEEK WILL DRIVE A COOL FRONT THRU THE CENTRAL PLAINS.
AHEAD OF THIS BOUNDARY...LOW LEVEL WARM AIR AND MOIST ADVECTION
COULD LEAD TO A SCATTERED CHANCE OF SHOWERS AND THUNDERSTORMS
THURSDAY. SEVERE THREAT WOULD LIKELY REMAIN FAR TO OUR
NORTH...CLOSER TO POTENT SHORTWAVE ENERGY.

&&

.AVIATION...

18Z TAFS FOR KOMA...KLNK AND KOFK.
SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO AFFECT KOMA
AND KLNK THIS AFTERNOON. KEPT CIGS VFR WITH MOST CIGS IN THE FL060
TO FL100 LEVEL. SFC WINDS HAVE BEEN VARIABLE WITH OUTFLOW AND
NORTHWEST WINDS ASSOCIATED WITH PRECIPITATION AND GUSTY WINDS
FROM THE SOUTHEAST BEHIND PRECIPITATION AREA. SOME OF THE SHORT
TERM MODELS ARE HOLDING ON TO CIGS OVERNIGHT...THOUGHT TREND
SHOULD BE FOR SCATTERING OUT ALTHOUGH THERE COULD BE SOME PATCHY
FOG.

ZAPOTOCNY

&&

.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.

&&

$$




AREA FORECAST DISCUSSION...UPDATED

NWS LUBBOCK TX

 551 PM CDT SAT AUG 18 2012

.UPDATE...
QUICK UPDATE TO REMOVE HALL...CHILDRESS AND COTTLE COUNTIES FROM
THE SEVERE THUNDERSTORM WATCH. OVERALL...STORM INTENSITY HAS BEEN
RATHER TAME...THOUGH A FEW CELLS DO OCCASIONALLY PULSE UP. IN
ADDITION...A SMALL CLUSTER OF STORMS COULD GENERATE GUSTY WINDS AS
THEY MOVE THROUGH THE SOUTHEASTERN ZONES OVER THE NEXT HALF HOUR
TO HOUR. UPDATED PRODUCTS HAVE BEEN SENT.

&&

.PREV DISCUSSION... /ISSUED 339 PM CDT SAT AUG 18 2012/

SHORT TERM...
WELL-DEFINED OUTFLOW BOUNDARY/COMPOSITE COLD FRONT WAS MOVING
SOUTHWEST INTO CHILDRESS AND HALL COUNTIES JUST NORTH OF A SURFACE
TROUGH STRETCHING FROM NEAR DIMMITT ESE TO SWEARINGEN. THE TRUE COLD
FRONT OF INTEREST THAT IS PROGGED TO DROP HIGHS BELOW NORMAL ON
SUNDAY /UNDER MOSTLY SUNNY SKIES!/ WAS FOUND DIVING SOUTH ACROSS WRN
KANSAS AND ERN COLORADO. BRUNT OF THE PRECIP POTENTIAL WILL BE
RELEGATED TO THE PRE-FRONTAL BOUNDARIES CURRENTLY CONVECTING ACROSS
THE NRN HALF OF THE CWA. ALTHOUGH WIND SHEAR IS WEAK THUS FAR...THIS
WILL IMPROVE AS THE AFTERNOON AND EARLY EVENING WEAR ON COURTESY OF
A SHORTWAVE TROUGH AND ASSOCIATED WIND MAX APPROACHING IN NORTHWEST
FLOW. EVEN WITH MLCAPES GENERALLY AOB 1000 J/KG...THIS IMPROVING
LIFT SHOULD SECURE A WINDOW FOR ORGANIZED SEVERE STORMS MAINLY IN
THE FORM OF SMALL SEGMENTS OR LINES WITH DMGG WINDS THE GREATEST
THREAT BEFORE INTENSITY AND STORM COVERAGE WANE BY LATE EVENING.
CURRENT SVR WATCH CAPTURES THIS THREAT WELL...BUT MAY REQUIRE
EXPANSION SWWD SHOULD TRENDS WARRANT. A FEW HI-RES MODELS SUCH AS
THE TTU WRF AND HRRR DO INDICATE SUCH A SCENARIO FOR LUBBOCK AND
POINTS SOUTHWEST...SO THIS WILL BE MONITORED CLOSELY BY THE ONCOMING
SHIFT. OTHERWISE...FROPA WILL OCCUR AFTER MIDNIGHT FOLLOWED BY
DIMINISHING POPS. MOIST POST-FRONTAL UPSLOPE TOMORROW AFTN IN ERN NM
AND ADJACENT COUNTIES OF THE TX SOUTH PLAINS STILL APPEARS
REASONABLE FOR SLIGHT CHANCE POPS IN OUR SWRN COUNTIES...HOWEVER THE
NAM LOOKS MUCH TOO BULLISH WITH QPF IN SUCH A REGIME AND IS LARGELY
BEING DISMISSED

LONG TERM...
NNW FLOW ALOFT IS EXPECTED ON MONDAY.  HIGH AMPLITUDE RIDGE WILL
SPAN FROM NWRN MEXICO UP TO NORTHERN ALBERTA.  OUT EAST...MATURE LOW
WILL BE SITUATED OVER THE SRN PART OF HUDSON BAY WITH AN EMBEDDED
SHORTWAVE DUE INTO THE CENTRAL PLAINS EARLY ON TUESDAY ALTHOUGH THE
BEST ENERGY ASSOCIATED WITH THIS SYSTEM WILL LIKELY REMAIN NORTHEAST
OF THE REGION.  BY MID WEEK...THE RIDGE WILL BEGIN TO MOVE EASTWARD
AND FLATTEN WITH SOME HINTS IN BOTH THE GFS AND ECM ABOUT A BIT OF A
DISTURBANCE PASSING TO OUR NORTH ON THURSDAY.  WHILE THE ECM
SOLUTION WOULD BE MORE FAVORABLE INTO BRINGING A FRONT INTO THE
REGION...AND PRECIPITATION...THE GFS HAS MORE CLOSELY PARALLELED
REALITY FOR THE PAST WEEK AND THUS WILL TREND THE FORECAST IN THAT
DIRECTION.

GIVEN NWP PERFORMANCE AS OF LATE WRT QPF AM NOT COMPLETELY CONVINCED
THAT WE WILL SEE AS MUCH RAIN ACROSS THE REGION AS PREVIOUSLY
THOUGHT...BUT HAVE ELECTED ONLY TO MAKE A DOWNWARD TREND OF MONDAY
NIGHT POPS.  LIKE TODAY...VIRTUALLY EVERY MODEL CONVECTS BUT PRECIP
HAS BEEN HARD TO COME BY.  AS PREVIOUSLY MENTIONED...SHORTWAVE
PASSES TO OUR NORTH SOMETIME ON THURSDAY BUT AGAIN...CONFIDENCE IN
MEANINGFUL RAINFALL IS TOO LOW FOR MENTION IN THE WX GRIDS ATTM.
GIVEN THAT...MOST OF THE EXTENDED LOOKS DRY ALTHOUGH WE WOULD LOVE
TO BE WRONG ABOUT THAT.

&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        61  83  57  85  58 /  30  10  10  20  30
TULIA         63  83  61  85  60 /  40  10  10  10  30
PLAINVIEW     64  82  61  88  63 /  50  10  10  10  30
LEVELLAND     66  83  61  89  63 /  50  20  10  10  30
LUBBOCK       67  84  62  90  65 /  50  20  10  10  30
DENVER CITY   66  84  62  93  63 /  40  20  10  10  20
BROWNFIELD    66  84  62  93  65 /  50  20  10  10  20
CHILDRESS     68  87  64  91  64 /  40  10   0  10  30
SPUR          68  86  65  94  68 /  50  20  10  10  20
ASPERMONT     70  89  67  97  68 /  50  20  10  10  20

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

33/23






AREA FORECAST DISCUSSION

NWS LUBBOCK TX

 339 PM CDT SAT AUG 18 2012

.SHORT TERM...
WELL-DEFINED OUTFLOW BOUNDARY/COMPOSITE COLD FRONT WAS MOVING
SOUTHWEST INTO CHILDRESS AND HALL COUNTIES JUST NORTH OF A SURFACE
TROUGH STRETCHING FROM NEAR DIMMITT ESE TO SWEARINGEN. THE TRUE COLD
FRONT OF INTEREST THAT IS PROGGED TO DROP HIGHS BELOW NORMAL ON
SUNDAY /UNDER MOSTLY SUNNY SKIES!/ WAS FOUND DIVING SOUTH ACROSS WRN
KANSAS AND ERN COLORADO. BRUNT OF THE PRECIP POTENTIAL WILL BE
RELEGATED TO THE PRE-FRONTAL BOUNDARIES CURRENTLY CONVECTING ACROSS
THE NRN HALF OF THE CWA. ALTHOUGH WIND SHEAR IS WEAK THUS FAR...THIS
WILL IMPROVE AS THE AFTERNOON AND EARLY EVENING WEAR ON COURTESY OF
A SHORTWAVE TROUGH AND ASSOCIATED WIND MAX APPROACHING IN NORTHWEST
FLOW. EVEN WITH MLCAPES GENERALLY AOB 1000 J/KG...THIS IMPROVING
LIFT SHOULD SECURE A WINDOW FOR ORGANIZED SEVERE STORMS MAINLY IN
THE FORM OF SMALL SEGMENTS OR LINES WITH DMGG WINDS THE GREATEST
THREAT BEFORE INTENSITY AND STORM COVERAGE WANE BY LATE EVENING.
CURRENT SVR WATCH CAPTURES THIS THREAT WELL...BUT MAY REQUIRE
EXPANSION SWWD SHOULD TRENDS WARRANT. A FEW HI-RES MODELS SUCH AS
THE TTU WRF AND HRRR DO INDICATE SUCH A SCENARIO FOR LUBBOCK AND
POINTS SOUTHWEST...SO THIS WILL BE MONITORED CLOSELY BY THE ONCOMING
SHIFT. OTHERWISE...FROPA WILL OCCUR AFTER MIDNIGHT FOLLOWED BY
DIMINISHING POPS. MOIST POST-FRONTAL UPSLOPE TOMORROW AFTN IN ERN NM
AND ADJACENT COUNTIES OF THE TX SOUTH PLAINS STILL APPEARS
REASONABLE FOR SLIGHT CHANCE POPS IN OUR SWRN COUNTIES...HOWEVER THE
NAM LOOKS MUCH TOO BULLISH WITH QPF IN SUCH A REGIME AND IS LARGELY
BEING DISMISSED

&&

.LONG TERM...
NNW FLOW ALOFT IS EXPECTED ON MONDAY.  HIGH AMPLITUDE RIDGE WILL
SPAN FROM NWRN MEXICO UP TO NORTHERN ALBERTA.  OUT EAST...MATURE LOW
WILL BE SITUATED OVER THE SRN PART OF HUDSON BAY WITH AN EMBEDDED
SHORTWAVE DUE INTO THE CENTRAL PLAINS EARLY ON TUESDAY ALTHOUGH THE
BEST ENERGY ASSOCIATED WITH THIS SYSTEM WILL LIKELY REMAIN NORTHEAST
OF THE REGION.  BY MID WEEK...THE RIDGE WILL BEGIN TO MOVE EASTWARD
AND FLATTEN WITH SOME HINTS IN BOTH THE GFS AND ECM ABOUT A BIT OF A
DISTURBANCE PASSING TO OUR NORTH ON THURSDAY.  WHILE THE ECM
SOLUTION WOULD BE MORE FAVORABLE INTO BRINGING A FRONT INTO THE
REGION...AND PRECIPITATION...THE GFS HAS MORE CLOSELY PARALLELED
REALITY FOR THE PAST WEEK AND THUS WILL TREND THE FORECAST IN THAT
DIRECTION.

GIVEN NWP PERFORMANCE AS OF LATE WRT QPF AM NOT COMPLETELY CONVINCED
THAT WE WILL SEE AS MUCH RAIN ACROSS THE REGION AS PREVIOUSLY
THOUGHT...BUT HAVE ELECTED ONLY TO MAKE A DOWNWARD TREND OF MONDAY
NIGHT POPS.  LIKE TODAY...VIRTUALLY EVERY MODEL CONVECTS BUT PRECIP
HAS BEEN HARD TO COME BY.  AS PREVIOUSLY MENTIONED...SHORTWAVE
PASSES TO OUR NORTH SOMETIME ON THURSDAY BUT AGAIN...CONFIDENCE IN
MEANINGFUL RAINFALL IS TOO LOW FOR MENTION IN THE WX GRIDS ATTM.
GIVEN THAT...MOST OF THE EXTENDED LOOKS DRY ALTHOUGH WE WOULD LOVE
TO BE WRONG ABOUT THAT.


&&

.PRELIMINARY POINT TEMPS/POPS...
FRIONA        61  83  57  85  58 /  30  10  10  20  30
TULIA         63  83  61  85  60 /  40  10  10  10  30
PLAINVIEW     64  82  61  88  63 /  50  10  10  10  30
LEVELLAND     66  83  61  89  63 /  50  20  10  10  30
LUBBOCK       67  84  62  90  65 /  50  20  10  10  30
DENVER CITY   66  84  62  93  63 /  40  20  10  10  20
BROWNFIELD    66  84  62  93  65 /  50  20  10  10  20
CHILDRESS     68  87  64  91  64 /  40  10   0  10  30
SPUR          68  86  65  94  68 /  50  20  10  10  20
ASPERMONT     70  89  67  97  68 /  50  20  10  10  20

&&

.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

93/26