Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/04/12
AREA FORECAST DISCUSSION
NWS DENVER CO
742 PM MDT FRI AUG 3 2012
.UPDATE...GUSTY WEST WINDS HAVE SPREAD ACROSS THE URBAN CORRIDOR
AHEAD OF A COLD FRONT THAT IS JUST ENTERING NORTHEAST COLORADO.
THIS FRONT WILL SWEEP SOUTH THROUGH THE EVENING HOURS...PASSING
THROUGH THE DENVER AREA AROUND 10 PM. AIRMASS IS QUITE DRY ACROSS
THE FORECAST AREA WITH DEW POINTS IN THE 20S AND 30S. THERE IS GOOD
QG LIFT OVER THE AREA AT THIS TIME WHICH IS PRODUCING MID AND
UPPER LEVEL CLOUDS. A FEW SHORT LIVED SHOWERS AND A THUNDERSTORM
HAVE FORMED OVER SOUTHERN WYOMING BEHIND THE FRONT IN THE DRY
AIRMASS. BECAUSE OF THE LIFT BEHIND THE FRONT AND MID AND UPPER
LEVEL LIFT IN PLACE...ADDED A SLIGHT CHANCE FOR SHOWERS AND STORMS
TO THE FORECAST THIS EVENING FOR THE DENVER METRO AREA. IF ANY
THING DEVELOPS IT WOULD BE BEHIND THE FRONT AND SHORT LIVED. THE
LAST RAP MODEL IS SHOWING WEAK QPF BEHIND THE FRONT...WHICH
SUPPORTS THE IDEA OF A FEW SHOWERS OR STORMS BEHIND THE FRONT.
THERE IS A BOUNDARY OVER EASTERN COLORADO...EAST OF IT DEW POINTS
ARE IN THE 40S AND LOWER 50S. ONCE THE FRONT RUNS INTO THE MORE
MOIST AIRMASS...EXPECT SCATTERED THUNDERSTORMS TO FORM. MOST OF
THESE WILL BE EAST OF THE FORECAST AREA BUT A FEW MAY CLIP
WASHINGTON...LINCOLN...PHILLIPS AND SEDGEWICK COUNTIES. DID
INCREASE POPS TO AROUND 50 PERCENT FOR THE FAR EASTERN PARTS OF
THE FORECAST AREA.
&&
.AVIATION...GUSTY WEST WINDS WILL TURN NORTH-NORTHEAST BETWEEN 04Z
AND 05Z AS A COLD FRONT PUSHES THROUGH THE AREA. THERE IS A SLIGHT
CHANCE FOR A THUNDERSTORM BEHIND THE FRONT UNTIL 07Z. MOISTURE
WILL INCREASE BEHIND THE FRONT AND PRODUCE LOW CLOUDS FROM ABOUT
09Z TO 15Z. CEILING ARE EXPECTED TO BE IN THE 3000 TO 6000 FEET
RANGE.
&&
.PREV DISCUSSION... /ISSUED 244 PM MDT FRI AUG 3 2012/
SHORT TERM...A COLD FRONT ASSOCIATED WITH AN UPPER LEVEL TROUGH
MOVING ACROSS MONTANA AND INTO NORTH DAKOTA WILL USHER A BONAFIDE
COLD FRONT INTO THE FRONT RANGE FOOTHILLS...URBAN CORRIDOR AND
NORTHEAST PLAINS THIS EVENING. ISOLATED THUNDERSTORMS ON THE
FRINGE OF AN UPPER LEVEL JET MAX OF 80 KTS OVER SOUTHERN WYOMING
WILL PERSIST OVER GRAND...JACKSON AND LARIMER COUNTIES THROUGH
EARLY THIS EVENING. THE GOES SOUNDER TOTAL PRECIPITABLE
WATER IS MUCH DRIER IN THE LOWER LEVELS OVER THE NORTHERN HALF OF
THE CWFA. AS A RESULT...THOSE STORMS WILL BE HIGH BASED WITH
GUSTY WINDS AND LIGHTNING THE MAIN THREATS. ELSEWHERE...THERE WILL
BE SLIGHTLY BETTER MOISTURE IN THE LOWER LEVELS WITH EITHER
AFTERNOON HEATING OR THE INCOMING FRONT PROVIDING ENOUGH LIFT FOR
A FEW STORMS MAINLY EAST AND SOUTH OF THE DENVER AREA THIS EVENING. ON
SATURDAY...IT WILL BE MUCH COOLER WITH TEMPERATURES 10-15 DEGREES
LESS THAN TODAY. THE AIRMASS WILL BE TOO STABLE AS WELL. THE NAM12
SPATIAL CROSS-SECTIONS DO INCREASE THE MOISTURE ALONG THE FRONT
RANGE AND PALMER DIVIDE FOLLOWING THE COLD FRONT SO A FEW
SPRINKLES POSSIBLE SATURDAY MORNING. THE ONLY AREA WITH ENOUGH
MOISTURE AND INSTABILITY IN THE AFTERNOON FOR TSTMS WILL BE IN AND
AROUND PARK COUNTY SO WILL KEEP ISOLD TSTMS THERE.
LONG TERM...AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD BACK INTO THE
AREA ON SUN WITH SUBTROPICAL MOISTURE CONFINED MAINLY TO SRN
COLORADO. THUS WILL ONLY MENTION LOW POPS OVER THE HIGHER TERRAIN
ALONG AND SOUTH OF I-70. OVER NERN CO THERE IS SOME FAVORABLE CAPE
HOWEVER CAP IS RATHER STG WHICH WILL LIKELY INHIBIT CONVECTION. FOR
HIGHS WILL KEEP READINGS IN THE UPPER 80S TO LOWER 90S ACROSS THE
PLAINS.
BY MON AN UPPER LEVEL HIGH WILL BE CENTERED OVER COLORADO WITH WEAK
FLOW ALOFT. SOME SUBTROPICAL MOISTURE WILL BEGIN TO ROTATE AROUND
THE HIGH WHICH WILL LEAD TO AT LEAST A SLIGHT CHC OF STORMS OVER THE
HIGHER TERRAIN. OVER NERN CO CURRENT SOUNDINGS SHOW VERY LITTLE
CAPE SO WILL NOT MENTION ANY TSTMS. HIGHS ON MON WILL CONTINUE TO
RISE WITH READINGS IN THE MID TO UPPER 90S ACROSS THE PLAINS. ON
TUE THE UPPER LEVEL HIGH WILL BEGIN TO SHIFT SLOWLY WESTWARD WITH
THE FLOW ALOFT BECOMING MORE WNW AS A WK DISTURBANCE MOVES ACROSS.
THUS SHOULD STILL SEE A CHC OF TSTMS IN MTNS WITH A SLIGHT CHC OVER
THE PLAINS. HIGHS ON TUE WILL STILL BE IN THE 90S ACROSS NERN CO.
FOR WED AND THU THE UPPER LEVEL HIGH WILL BE CENTERED OVER WRN CO
WITH A SOMEWHAT DRIER AIRMASS WITH LIMITED CAPE. THUS APPEARS TSTM
ACTIVITY MAY BECOME MORE ISOLD TO WDLY SCT OVER THE HIGHER TERRAIN
WITH NO ACTIVITY OVER NERN CO. TEMPS BOTH DAYS WILL REMAIN IN THE
90S ACROSS THE PLAINS.
AVIATION...OVERALL VFR CONDITIONS WILL PREVAIL. A COLD FRONT
EXPECTED TO MOVE INTO THE DENVER AREA IN THE 03-05Z TIME FRAME SO
THE TIMING MAY NEED TO BE ADJUSTED FURTHER IN THE UPCOMING TAFS.
WINDS HAVE BEEN WAFFLING BETWEEN WEST/NORTHWEST AND SOUTH THIS
AFTERNOON AND WILL LIKELY CONTINUE TO DO SO OVER THE NEXT HOUR OR
TWO. WINDS WILL BECOME NORTHWESTERLY JUST AHEAD OF THE COLD FRONT
THEN NORTHEAST FOLLOWING FROPA. LOWER LEVEL MOISTURE IS EXPECTED
TO INCREASE AFTER 06Z WITH BKN CIGS OF 040-060 DEVELOPING IN THE
09Z-15Z TIME FRAME.
HYDROLOGY...NO FLOODING CONCERNS FOR THE BURN AREAS TONIGHT OR
SATURDAY. THE LOWER LEVEL WILL BE MUCH DRIER SO GUSTY WINDS AND
LIGHTNING THE MAIN ISSUES THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...COOPER
LONG TERM....RPK
UPDATE/AVIATION...MEIER
AREA FORECAST DISCUSSION
NWS PUEBLO CO
328 PM MDT THU AUG 2 2012
.SHORT TERM...
(TONIGHT AND FRIDAY)
THE MONSOON MOISTURE PLUME REMAINS OVER THE AREA WITH SHOWERS AND
THUNDERSTORMS OVER AND NEAR THE MOUNTAINS EARLY THIS AFTERNOON. THE
MODELS ARE SHOWING THE CONVECTIVE ACTIVITY SPREADING ACRS THE
PLAINS LATE THIS AFTERNOON THROUGH THE EVENING HOURS...IN
ASSOCIATION WITH A WEAK DISTURBANCE WORKING ITS WAY EAST ACRS
SOUTHERN CO. THE HRRR SHOWS A BAND OF PCPN COMING OFF THE MTS BY
00Z...MOVING EASTWARD ACRS THE PLAINS AND EXITING CO BY 04Z. THE
NSSL 4KM WRF IS VERY SIMILAR. BASED ON THESE HIGH RES MODELS WL GO
AHEAD AND END PCPN CHANCES IN THE FORECAST BY MIDNIGHT...HOWEVER
BOTH THE NAM AND GFS KEEP CHANCES FOR PCPN OVR THE FAR SERN PLAINS
THROUGH THE NIGHT AND INTO FRI MORNING. THERE IS THE POTENTIAL FOR
HEAVY RAIN TODAY UNDER SOME OF THE STRONGER STORMS...WITH THE WALDO
CANYON BURN SCARS BEING THE MOST VULNERABLE IF HEAVY RAIN DEVELOPS
OVR THAT AREA.
ON FRI THE BULK OF THE MONSOON MOISTURE WILL BE OVR SOUTHERN
PORTIONS OF THE FORECAST AREA...AS AN UPR TROF OVR THE NRN ROCKIES
FLATTENS THE RIDGE OVR OUR AREA. THUS THE BEST CHANCES FOR
CONVECTIVE ACTIVITY SHOULD OCCUR OVR THE SRN HALF OF THE CWA. THE
GFS HAS LITTLE IN THE WAY OF PCPN COVERAGE FOR FRI AFTERNOON...WHILE
THE NAM HAS A LITTLE MORE COVERAGE OVER THE FAR SOUTHEAST
PLAINS...THE SANGRES AND THE EASTERN SAN JUANS. HIGH TEMPS ON FRIDAY
SHOULD BE A FEW DEGREES ABOVE NORMAL IN MOST LOCATIONS.
.LONG TERM...
(FRIDAY NIGHT THROUGH THURSDAY)
LONGER TERM METEOROLOGICAL ISSUES CONTINUE TO BE POPS AND
TEMPERATURES. LATEST COMPUTER SOLUTIONS INDICATE THAT STRONG UPPER
RIDGE CENTERED OVER NORTHWESTERN TEXAS AT 00Z SATURDAY WILL BEGIN
TO PUSH WEST INTO NEW MEXICO BY LATER SUNDAY BEFORE BECOMING
CENTERED NEAR THE 4-CORNERS REGION BY NEXT TUESDAY. IN
ADDITION...HEALTHY NORTHERLY SURGE IS PROJECTED TO PUSH ACROSS
EASTERN SECTIONS OF THE FORECAST DISTRICT BY SATURDAY MORNING.
ENOUGH ATMOSPHERIC MOISTURE IS EXPECTED TO REMAIN AVAILABLE OVER
THE FORECAST DISTRICT AND COMBINE WITH OCCASIONAL UPPER WAVES AND
THE DAILY HEATING CYCLE/SURFACE BOUNDARIES TO ALLOW DAILY ISOLATED
TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE HIGHER TERRAIN REGIONS.
SOME OF THE STRONGER THUNDERSTORMS ARE EXPECTED TO PRODUCE PERIODS
OF LOCALLY HEAVY RAINFALL CAPABLE OF PRODUCING LOCALIZED FLASH
FLOODING ISSUES...ESPECIALLY IF A STORM DIRECTLY IMPACTS BURN SCAR
AREAS...SUCH AS THE WALDO BURN SCAR. IN ADDITION...THE STRONGER
STORMS WILL ALSO BE CAPABLE OF PRODUCING HAZARDOUS LIGHTNING...HAIL
AND GUSTY WINDS.
FINALLY...BELOW SEASONAL MAXIMUM TEMPERATURES SHOULD BE NOTED IN
THE WAKE OF THE STRONG NORTHERLY SURGE SATURDAY(ESPECIALLY EASTERN
SECTIONS) WITH MAXIMUM TEMPERATURES THEN REBOUNDING TO ABOVE
EARLY AUGUST SEASONAL AVERAGES NEXT WEEK.
&&
.AVIATION...
KALS...KCOS AND KPUB WILL HAVE VFR CONDITIONS MOST OF THE TIME
DURING THE NEXT 24 HRS. THERE WILL BE A CHANCE FOR SHOWERS AND
THUNDERSTORMS AT OR IN THE VCNTY OF THE TAF SITES THROUGH AROUND
03Z. THUNDERSTORMS COULD BRING BRIEF MVFR CONDITIONS TO THE TAF
SITES. OUTFLOW WINDS COULD ALSO BRING WIND GUSTS UP TO 45 KTS.
ON FRIDAY AFTERNOON WE COULD SEE SOME THUNDERSTORMS IN THE VCNTY OF
THE TAF SITES AFTER 20Z...BUT CONFIDENCE IS LOW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
155 PM EDT THU AUG 2 2012
.SYNOPSIS...
17Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE
SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT
WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND
ANOTHER RIDGE OVER CUBA/BAHAMAS.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE
SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT
OF THE SW TO THE MAJORITY OF THE FORECAST AREA.
&&
.SHORT TERM (TONIGHT THROUGH SATURDAY NIGHT)...
TONIGHT...SUBTROPICAL RIDGE AXIS BEGINS TO SHIFT SLOWLY NORTHWARD
OVER THE FLORIDA PENINSULA/EASTERN GULF IN RESPONSE TO THE APPROACH
OF A WEAK INVERTED TROUGH/WAVE TO THE EAST OF THE BAHAMAS. MAINLY
INLAND SCT CONVECTION EARLY THIS EVENING SHOULD DISSIPATE WITHIN A
COUPLE HOUR OF SUNSET SETTING UP DRY CONDITIONS FOR MUCH OF THE AREA
FROM LATE NIGHT INTO THE EARLY MORNING HOURS. WITH THE UPPER HEIGHT
WEAKNESS STILL IN PLACE OVER THE EASTERN GULF...WOULD EXPECT TO SEE
AT LEAST SOME DEGREE OF NOCTURNAL CONVECTION REDEVELOP TOWARD DAWN
OVER THE COASTAL WATERS. THE RIDGE AXIS LIFTING NORTH WILL ALSO
SHIFT THE FAVORED SW FLOW NORTH...SO WOULD ANTICIPATE THE MAJORITY
OF THIS ACTIVITY TO DEVELOP OVER THE NORTHERN WATERS/ALONG THE
NATURE COAST. FURTHER SOUTH (SOUTH OF TAMPA BAY)...A 1000-700MB FLOW
MORE PARALLEL TO THE COAST (OR EVEN SOUTHEASTERLY) SHOULD GENERALLY
KEEP ANY ISOLATED CELLS FROM MIGRATING BACK TO THE BEACHES.
FRIDAY...TYPICAL EARLY AUGUST CONDITIONS ARE EXPECTED FOR THE
FINAL DAY OF THE WORK WEEK. WILL BE CONTINUING TO WATCH THE SLOW
APPROACH OF A WEAK SURFACE TROUGH TOWARD THE FLORIDA EAST
COAST...HOWEVER MUCH OF THE LOW LEVEL FOCUS ASSOCIATED WITH THIS
FEATURE WILL REMAIN TO OUR EAST DURING THE FAVORED DIURNAL
CONVECTIVE MAX TIME-FRAME. 1000-700MB FLOW WILL INITIALLY BE QUITE
LIGHT AHEAD OF THIS TROUGH ALLOWING THE WEST COAST SEA-BREEZE TO BE
THE DOMINANT TRIGGER FOR ISOLATED-SCT CONVECTION NEAR THE COAST IN
THE EARLY AFTERNOON. LATER IN THE DAY...AS THE TROUGH GETS A BIT
CLOSER...THE FLOW WILL TRANSITION MORE EASTERLY. WITH THIS IN
MIND...IT IS LIKELY THAT THE SEA-BREEZE WILL BE SIGNIFICANTLY SLOWED
IN ITS INLAND PROPAGATION. THE ENHANCED LOW LEVEL CONVERGENCE MAY
ALLOW FOR A FEW STRONGER UPDRAFTS/PRECIPITATION LOADING AND A
RESULTING ISOLATED CONVECTIVE WIND THREAT. UNLIKE PREVIOUS
DAYS...THIS PATTERN SHOULD PREVENT THE LATE AFTERNOON DROP OFF IN
CONVECTIVE COVERAGE CLOSE TO THE COAST.
FRIDAY NIGHT/SATURDAY...
SURFACE TROUGH OVERSPREADS THE FLORIDA PENINSULA AND BECOMES
ESTABLISHED OVER THE WEST COAST DURING SATURDAY AFTERNOON. THE
COMBINATION OF INCREASING COLUMN MOISTURE...AND LOW LEVEL FOCUS
SHOULD HELP TO PROVIDE A CONVECTIVE ACTIVE PERIOD...ESPECIALLY
DURING SATURDAY AFTERNOON/EVENING. 1000-700MB FLOW IS STRAIGHT OUT
OF THE EAST AND THEREFORE QUITE FAVORABLE FOR ENHANCED CONVERGENCE
ALONG THE WEST-COAST SEA-BREEZE. SIMILAR TO FRIDAY...THIS PATTERN
SHOULD SUPPORT A FEW STRONGER UPDRAFTS AND THE POTENTIAL FOR SOME
LOCALIZED STRONGER STORMS.
&&
.LONG TERM (SUNDAY - NEXT WEDNESDAY)...
U/L RIDGE WILL PERSIST OVER THE ATLANTIC EXTENDING OVER THE SOUTHERN
PLAINS SUNDAY. U/L TROUGH WILL DIG OVER THE OHIO RIVER VALLEY MONDAY
AND TEMPORARILY WEAKEN THE RIDGE OVER FLORIDA. THE U/L RIDGE WILL
BUILD BACK OVER FLORIDA TUESDAY AND WEDNESDAY WITH INCREASING
SUBSIDENCE AND WARMER TEMPERATURES ACROSS WEST CENTRAL AND SOUTHWEST
FLORIDA. AT THE SURFACE...A TROPICAL WILL WAVE MOVE ACROSS THE
PENINSULA SUNDAY INCREASING DEEP LAYER MOISTURE AND INSTABILITY.
EASTERLY FLOW WILL ALLOW NUMEROUS SHOWERS AND THUNDERSTORMS TO
DEVELOP WITH LOCALLY HEAVY RAIN AND GUSTY WINDS WITH THE STRONGER
STORMS BOTH SUNDAY AND MONDAY. SURFACE RIDGE WILL BUILD ACROSS THE
CENTRAL PENINSULA TUESDAY AND WEDNESDAY. AS THE U/L RIDGE BUILDS
BACK OVER FLORIDA AND DRIER AIR ALOFT ADVECTING OVER THE FORECAST
AREA...AREAL COVERAGE OF AFTERNOON SHOWERS AND THUNDERSTORMS WILL
DECREASE EACH DAY.
&&
.AVIATION...
SOME SHOWERS AND STORMS VICINITY TPA...PIE AND SRQ SHOULD MOVE EAST
OF TERMINALS BY 20Z. PGD...FMY AND RSW SHOULD STAY MAINLY VFR.
HIGHEST PROBABILITY OF MVFR OR EVEN IFR WOULD BE AT LAL BUT
CONFIDENCE NOT HIGH ENOUGH FOR TEMPO GROUPS AT THIS TIME.
&&
.MARINE...
THE SUBTROPICAL RIDGE AXIS WILL SLOWLY SHIFT NORTH OVER THE AREA
THROUGH FRIDAY AND THEN REMAIN TO THE NORTH OF THE FORECAST WATERS
THROUGH THE UPCOMING WEEKEND. THIS MOVEMENT WILL SHIFT SYNOPTIC FLOW
FROM THE SOUTH AND SOUTHWEST TO AN EAST AND SOUTHEAST DIRECTION.
LOCAL SEA-BREEZE CIRCULATIONS WILL TURN THE FLOW ONSHORE NEAR THE
COAST EACH AFTERNOON.
&&
.FIRE WEATHER...
BEST RAIN CHANCES WILL BE ACROSS THE INTERIOR NEXT COUPLE OF DAYS AS
WESTERLY FLOW CONTINUES. A TROPICAL WAVE WILL BRING HIGHER RAIN
CHANCES TO THE GULF COAST OVER THE WEEKEND AND INTO THE FIRST PART
OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 77 92 77 91 / 20 40 20 40
FMY 76 93 75 92 / 20 40 20 60
GIF 75 94 74 94 / 30 40 20 40
SRQ 76 92 75 92 / 10 40 20 40
BKV 69 93 71 92 / 20 30 20 40
SPG 79 91 79 91 / 20 30 20 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
AVIATION...JILLSON
LONG TERM...OGLESBY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1045 AM EDT THU AUG 2 2012
.UPDATE...
14Z WATER VAPOR AND H4 RAP ANALYSIS CONTINUES TO SHOW THE
SOUTHEASTERN CONUS AND EASTERN GULF UNDERNEATH A SUBTLE HEIGHT
WEAKNESS BETWEEN A DOMINANT UPPER RIDGE OVER THE SOUTHERN PLAINS AND
ANOTHER RIDGE OVER CUBA/BAHAMAS.
AT THE SURFACE...SUBTROPICAL RIDGE AXIS EXTENDS ACROSS THE
SOUTH-CENTRAL FLORIDA PENINSULA PROVIDING A LIGHT LOW LEVEL FLOW OUT
OF THE SW TO THE MAJORITY OF THE FORECAST AREA. THE FAVORED SW FLOW
FOR NOCTURNAL MARINE SHOWERS COMBINED WITH THE SYNOPTIC SUPPORT
ASSOCIATED WITH THE WEAKNESS ALOFT PROVIDED THE FORCING FOR SCT-NMRS
CONVECTION OVER THE NORTHERN COASTAL WATERS THIS MORNING.
IN THE NEXT FEW HOURS...WILL LIKELY SEE A DECREASE IN THE COVERAGE
OF CONVECTION OVER THE COASTAL WATERS AS THE SEA-BREEZE TRANSLATES
THE BEST LOW LEVEL CONVERGENCE ONSHORE. ALREADY BEGINNING TO SEE THE
FIRST STAGE OF SHOWERS DEVELOPING ALONG THE NATURE COAST AND SHOULD
SEE THIS SCT ACTIVITY EXPAND DOWN INTO THE TAMPA BAY AREA AND
SOUTHWARD BY NOON.
SIMILAR TO WEDNESDAY...THE BEST CHANCES FOR SHOWERS ALONG THE
COASTAL ZONES WILL BE THROUGH EARLY AFTERNOON WITH CONVECTION
PUSHING FURTHER INLAND WITH THE SEA-BREEZE BY THE LATER AFTERNOON
HOURS. WILL NOT COMPLETELY REMOVE POPS CLOSE TO THE COAST LATER
TODAY...BUT WILL TRANSLATE WORDING FROM SCATTERED TO ISOLATED.
PLENTY OF MORNING INSOLATION HAS ALLOWED TEMPERATURES TO QUICKLY
REBOUND INTO THE MIDDLE AND UPPER 80S. SHOULD HAVE LITTLE TROUBLE
REACHING THE LOWER 90S INLAND AND UPPER 80S TO AROUND 90 AT THE
COAST FOR LOCATIONS WHICH AVOID SIGNIFICANT SHOWER ACTIVITY. CURRENT
TEMPERATURE/DEWPOINT GRIDS ARE IN GOOD SHAPE AND WILL NOT BE MAKING
ANY SIGNIFICANT CHANGES THROUGH THE EVENING HOURS.
&&
.PREVIOUS (FRIDAY - SATURDAY)...
PERSISTENT MID LEVEL TROUGH OVER THE EASTERN U.S EXTENDING SOUTH
INTO THE NORTHERN GULF WILL WEAKEN DURING THE SHORT TERM PERIOD
AS THE SUBTROPICAL RIDGE FROM THE WESTERN ATLANTIC WEST ACROSS THE
SOUTHERN PENINSULA SHIFTS NORTH FRIDAY INTO THE UPCOMING WEEKEND.
AS FOR TODAY MODELS DEPICT SLIGHTLY DRIER AIR MOVING INTO WEST
CENTRAL AND SOUTHWEST FLORID ASSOCIATED WITH THE RIDGE. THIS DRY
AIR SHOULD RESULT IN LOWER STORM COVERAGE WITH POPS IN THE 20 TO 30
PERCENT RANGE FROM THE COAST TO INTERIOR LOCATIONS WHICH IS DEPICTED
WELL BY THE MAV AND NAM POP GUIDANCE.
THE SURFACE RIDGE AXIS WILL LIFT NORTH TO THE CENTRAL PENINSULA ON
FRIDAY. A SLOW INCREASE IN MOISTURE WILL LEAD TO HIGHER COVERAGE OF
SCATTERED SHOWERS AND STORMS ALONG THE EAST AND WEST COAST SEA BREEZE
BOUNDARIES WITH HIGHEST POPS (40 PERCENT) EXPECTED TO SET UP OVER
INLAND LOCATIONS ALONG THE SEA BREEZE MERGER DURING THE AFTERNOON
HOURS...WITH 30 PERCENT POPS ALONG THE COAST.
DURING FRIDAY NIGHT INTO SATURDAY DEEPER MOISTURE (PW`S INCREASING
TOWARD 2 INCHES) WILL OVERSPREAD THE REGION FROM THE SOUTHEAST AHEAD
OF A TROPICAL WAVE WHICH IS FORECAST TO MOVE ACROSS THE SOUTH CENTRAL
PENINSULA DURING SATURDAY AND SATURDAY NIGHT. THIS MOISTURE WILL LEAD
TO EVEN HIGHER CHANCES (POPS 30 TO 50 PERCENT RANGE) FOR SHOWERS AND
STORMS ALONG WITH SOME LOCALLY HEAVY RAINFALL AS THE WAVE AFFECTS
THE REGION. TEMPERATURES WILL CONTINUE TO RUN A FEW DEGREES ABOVE
NORMAL WITH DAYTIME HIGHS CLIMBING INTO THE LOWER AND MID 90S WITH
NIGHTTIME LOWS IN THE LOWER 70S NORTH AND MID TO UPPER 70S CENTRAL
AND SOUTH.
&&
.AVIATION...
SOME SMALL SHOWERS MOVING IN FROM THE GULF COULD BRING BRIEF MVFR
CEILINGS AT TPA...PIE AND SRQ THROUGH 14 OR 15Z. MAIN ACTIVITY WILL
BE INLAND THIS AFTERNOON WITH LAL THE MOST LIKELY TO SEE IMPACTS.
&&
.MARINE...
SURFACE HIGH PRESSURE ACROSS THE SOUTHERN PENINSULA TODAY WILL
MAINTAIN A SOUTHWEST TO WEST WIND FLOW AT 10 KNOTS OR LESS ALONG
WITH SEAS OF 2 FEET OR LESS. DURING FRIDAY AND INTO THE UPCOMING
WEEKEND THE SURFACE RIDGE AXIS WILL SHIFT NORTH TO THE NORTH
CENTRAL PENINSULA WITH WINDS BACKING TO THE SOUTHEAST AND
EAST...WITH A WEAK PRESSURE PATTERN SUPPORTING AN ENHANCED ONSHORE
SEA BREEZE COMPONENT DEVELOPING ALONG THE COAST EACH AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 92 76 92 78 / 30 20 30 10
FMY 94 76 93 76 / 30 20 30 10
GIF 95 76 95 76 / 30 20 40 20
SRQ 91 76 92 75 / 30 20 30 10
BKV 93 70 93 72 / 30 20 30 10
SPG 91 80 91 79 / 30 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
UPDATE...MROCZKA
AVIATION...JILLSON
PREVIOUS DISCUSSION...MCMICHAEL
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1013 PM EDT FRI AUG 3 2012
.UPDATE...
SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT
OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY
ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP
BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO
THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS
THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO
SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...
03
&&
.PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW.
ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS
THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT
STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN
THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO
2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE
INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS
CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL
PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH
00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK
NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE
ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON
AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR
OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD
COVER EXPECTED.
01
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD
AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND
SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF
MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND
TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE.
DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z
GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM
WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT
BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO
THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE
GFS...POPS MAY BE A LITTLE ON THE LOW SIDE.
11
&&
.AVIATION...
00Z UPDATE...
SCATTERED THUNDERSTORM DEVELOPMENT AND ASSOCIATED OUTFLOW
BOUNDARIES WILL CONTINUE TO BRING THE POTENTIAL FOR GUSTY VARIABLE
WINDS AND REDUCED VSBYS NEAR KATL AND OTHER SITES THIS EVENING.
CIGS WILL GENERALLY STAY VFR THROUGH 06Z TONIGHT THEN LIKELY LOWER
TO MVFR OR LOWER AT 1-2 KFT BETWEEN 06Z AND 15Z ALONG WITH SOME BR
AND 5-6SM VSBYS. WINDS SHOULD BECOME SSW TO SW STAYING FAIRLY
LIGHT OVERNIGHT AND UNDER 10KTS SATURDAY. TSRA IS POSSIBLE AGAIN
SATURDAY AFTERNOON SO HAVE INCLUDED PROB30 GROUP FROM 19-23Z.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CONVECTION AND OVERNIGHT CIGS.
HIGH CONFIDENCE ALL ELSE.
03
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 89 71 91 / 40 40 30 30
ATLANTA 74 87 72 89 / 30 40 40 30
BLAIRSVILLE 68 83 68 85 / 70 50 30 40
CARTERSVILLE 71 89 70 90 / 60 50 30 40
COLUMBUS 75 91 73 91 / 30 40 40 30
GAINESVILLE 72 87 71 89 / 60 40 30 30
MACON 74 91 72 92 / 30 40 40 30
ROME 72 91 71 91 / 60 50 30 50
PEACHTREE CITY 71 89 70 90 / 30 40 40 30
VIDALIA 73 93 74 93 / 20 30 20 30
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01/03
LONG TERM....11
AVIATION...03
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
630 AM EDT THU AUG 2 2012
.SYNOPSIS...
A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY
AND SUNDAY INCREASING THE CHANCES FOR RAINFALL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.THIS MORNING...A SMALL AREA OF SHOWERS WERE AFFECTING THE CSRA.
INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS THIS MORNING. THIS
ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE WHICH ACCORDING TO
THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST BY 13Z. ELSEWHERE
LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION PATCHY FOG
SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT HIGHER.
.TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID
AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK
IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS
AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK
CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH
MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES
RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S
WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS
IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44
PERCENT. SO WENT 20 PERCENT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20
PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S.
FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE
CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE
90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT
CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND
EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED
TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS
AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE
CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES
SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION
NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO
DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT
VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE
BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY.
THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND
THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE
MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD
HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S.
OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
POTENTIAL FOR MAINLY MVFR VSBYS EARLY THIS MORNING...OTHERWISE VFR
CONDITIONS EXPECTED. UPPER SHORT WAVE IS COMING THROUGH THIS MORNING
AND WILL PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION
POSSIBLE THIS MORNING...THEN IT APPEARS THAT MOST CONVECTIVE
COVERAGE THIS AFTERNOON WILL BE CONFINED TO THE SE FA AND COASTAL
PLAIN. CONFIDENCE/COVERAGE OF TS NOT SUFFICIENT TO INCLUDE IN THE
TAFS AT THIS TIME. CONVECTIVE ANALYSIS INDICATES STRONG
INSTABILITIES FOR THIS AFTERNOON...SO ANYTHING THAT DOES DEVELOP
THIS AFTN/EVE WILL HAVE THE POTENTIAL TO BE STRONG TO SEVERE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE
NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH THE PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
607 AM EDT THU AUG 2 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A
TROUGH OF LOW PRESSURE PERSISTS INLAND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A TYPICAL MID-
LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW BOUNDARIES
GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY INTERSECT
OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK SCATTERED
CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S SOLUTION
SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/ PLOWING
THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS NOT
SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL MODELS
ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE HIGHEST
GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95 CORRIDOR.
HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER TODAY...
ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS NEARLY
IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM THE MID
90S INLAND TO THE MID 80S AT THE BEACHES.
MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG
BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND
SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA
EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK
FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR
PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY
INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR
ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS
INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES.
EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM
COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY
LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES
DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM
THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES.
THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH
PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST.
HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST
UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT
SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY
ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH
PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND.
THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY
EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND
CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED
TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE
UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY
PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES
GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM.
THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT
ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL
LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY
LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH
OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND
AND UPPER 70S ALONG THE BEACHES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A
LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS
ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA
SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL
UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE
SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE
SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE
SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN
INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE
STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA
BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS
WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO
THE LOW TO MID 70S OVERNIGHT.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
VFR FOR THE NEXT 24 HOURS. LOW PROBABILITIES FOR TSTMS THIS
AFTERNOON AT BOTH TERMINALS.
EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY
AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS
THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT.
ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH
EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS
BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS
BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE
ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY
DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES
DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3
FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION...UPDATED
NWS COLUMBIA SC
545 AM EDT THU AUG 2 2012
.SYNOPSIS...
A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY
AND SUNDAY INCREASING THE CHANCES FOR RAINFALL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.THIS MORNING...A SMALL AREA OF SHOWERS AND THUNDERSTORMS WERE
AFFECTING THE CSRA. INCLUDED A 30-40 PERCENT CHANCE FOR 3-4 HOURS`
THIS MORNING. THIS ACTIVITY IS ASSOCIATED WITH A WEAK SHORT WAVE
WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE MOVED TO THE EAST
BY 13Z. ELSEWHERE LESS THAN 10 PERCENT. WILL CONTINUE TO MENTION
PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE DEWPOINTS ARE A BIT
HIGHER.
.TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID
AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK
IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS
AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK
CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH
MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES
RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S
WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS
IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44
PERCENT. SO WENT 20 PERCENT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20
PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S.
FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE
CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE
90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT
CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND
EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED
TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS
AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE
CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES
SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION
NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO
DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT
VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE
BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY.
THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND
THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE
MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD
HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S.
OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND
VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS
MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP
GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN
SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT
OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL
PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE
EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN
ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE
CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT
APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE
CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS
NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE
ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO
ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO
BE STRONG TO SEVERE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE
NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH THE PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
445 AM EDT THU AUG 2 2012
.SYNOPSIS...
A WARM HUMID AIRMASS WILL REMAIN ACROSS THE REGION TODAY AND
FRIDAY. THERE WILL BE A SLIGHT CHANCE OF AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS. A COLD FRONT WILL APPROACH SATURDAY
AND SUNDAY INCREASING THE CHANCES FOR RAINFALL.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
.THIS MORNING...SOME WEAKENING SHOWERS AND THUNDERSTORMS MAY
AFFECT THE EXTREME NORTHEAST PORTION...LANCASTER AND CHESTERFIELD
COUNTIES EARLY BEFORE SUNRISE. THIS ACTIVITY IS ASSOCIATED WITH
A WEAK SHORT WAVE WHICH ACCORDING TO THE RUC13 MODEL SHOULD HAVE
MOVED TO THE EAST BY 12Z. WILL RUN A 20 PERCENT IN MENTIONED
COUNTIES UNTIL 10Z...THEN LESS THAN 10 PERCENT. WILL CONTINUE
TO MENTION PATCHY FOG SOUTHEAST PART OF CWA WHERE SURFACE
DEWPOINTS ARE A BIT HIGHER.
.TODAY...WEAK HIGH PRESSURE REMAINS OVER REGION WITH A WARM HUMID
AIRMASS. UPPER TROUGH AXIS IS STILL TO THE EAST AND ANOTHER WEAK
IMPULSE IS EXPECTED DROP SOUTHWARD OVER THE AREA LATE THIS
AFTERNOON OR EARLY THIS EVENING. NAM BUFR SOUNDING SHOWS A WEAK
CAP BUT WITH A LARGE POSITIVE AREA. CAPES AROUND 3000 J/KG WITH
MODERATELY STRONG LIS NEAR -6. TOTALS OVER 50 WITH PW VALUES
RISING TO OVER 2 INCHES. AFTERNOON TEMPERATURES IN THE UPPER 90S
WILL CREATE STRONG LOW LEVEL LAPSE RATES. ALSO...CONVECTIVE TEMPS
IN THE LOWER 90S. PREFER A BLEND OF MAV 9 PERCENT AND MET 44
PERCENT. SO WENT 20 PERCENT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
A FEW LINGERING SHOWERS OR THUNDERSTORMS POSSIBLE. THINK A 20
PERCENT CHANCE WILL COVER IT FOR THIS EVENING. LOWS IN THE 70S.
FRIDAY PRETTY MUCH APPEARS TO BE A REPEAT OF THURSDAY. SOME MORE
CLOUDS SHOULD KEEP HIGHS FRIDAY 1-2 DEGREES LOWER IN THE MIDDLE
90S. STILL UNSTABLE ENOUGH FRIDAY AFTERNOON FOR ANOTHER 20 PERCENT
CHANCE OF SHOWERS OR THUNDERSTORMS DURING THE AFTERNOON AND
EVENING. LOWS FRIDAY NIGHT AGAIN IN THE 70S. SATURDAY IS EXPECTED
TO BRING AN INCREASE IN THE CHANCES FOR SHOWERS AND THUNDERSTORMS
AS A COLD FRONT APPROACHES FROM THE NORTHWEST. WILL INCREASE
CHANCES TO 30-40 PERCENT. MORE CLOUDS AND HIGHER RAIN CHANCES
SHOULD KEEP HIGHS DOWN A BIT INTO THE LOWER 90S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MEDIUM RANGE MODELS IN DECENT AGREEMENT WITH UPPER TROUGH POSITION
NEAR THE EAST COAST FOR THE PERIOD. SURFACE COLD FRONT EXPECTED TO
DROP SOUTHWARD BUT SHOULD MEET CONSIDERABLE RESISTANCE MAKING IT
VERY FAR TO THE SOUTH AS PREVIOUS FRONTS HAVE BEEN HELD UP BY THE
BERMUDA RIDGE. BUT THE FRONT WILL AT LEAST BE IN THE VICINITY.
THIS IS EXPECTED TO GIVE A 20-30 PERCENT CHANCE OF SHOWERS AND
THUNDERSTORMS. MOISTURE CONVERGENCE AHEAD OF THE FRONT SHOULD GIVE
MORE CLOUDS AND THIS ALONG WITH A BETTER CHANCE OF PRECIP SHOULD
HELP TO HOLD HIGH TEMPERATURES BACK TO NORMAL IN THE LOWER 90S.
OVERNIGHT LOWS NEAR NORMAL AS WELL IN THE LOWER 70S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
MOSTLY CLEAR SKIES AND LIGHT WINDS AT THE MOMENT. TEMPS AND
VSBYS HAVE BEEN SLOW TO FALL SO FAR THIS MORNING. LOW LEVELS NOT AS
MOIST AS 24 HOURS AGO...AS DRIER AIR WORKED IN WEDNESDAY. GFS LAMP
GUIDANCE HAS BEEN PERFORMING WELL RECENTLY...AND MOST RECENT RUN
SUGGESTS NO SIGNIFICANT RESTRICTIONS AT MOST TERMINALS...WITH IFR AT
OGB. STRONG UPPER SHORT WAVE IS COMING THROUGH THIS MORNING AND WILL
PUSH TOWARDS THE COAST THIS AFTERNOON. ISOLATED CONVECTION POSSIBLE
EARLY THIS MORNING. LATEST RADAR INDICATES A FEW SHOWERS AND AN
ISOLATED THUNDERSTORM OVER EAST CENTRAL GA MOVING SE TOWARDS THE
CSRA. WILL MONITOR FOR POSSIBLE INCLUSION IN THE DNL/AGS TAFS. IT
APPEARS THAT MOST CONVECTIVE COVERAGE THIS AFTERNOON WILL BE
CONFINED TO THE SE FA AND COASTAL PLAIN. CONFIDENCE/COVERAGE OF TS
NOT SUFFICIENT TO INCLUDE IN THE TAFS AT THIS TIME. CONVECTIVE
ANALYSIS INDICATES STRONG INSTABILITIES FOR THIS AFTERNOON...SO
ANYTHING THAT DOES DEVELOP THIS AFTN/EVE WILL HAVE THE POTENTIAL TO
BE STRONG TO SEVERE.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN LATE
NIGHT/EARLY MORNING FOG/STRATUS...AS WELL AS SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS THROUGH THE PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
323 AM EDT THU AUG 2 2012
.SYNOPSIS...
ATLANTIC HIGH PRESSURE WILL PREVAIL THROUGH THE WEEK...WHILE A
TROUGH OF LOW PRESSURE PERSISTS INLAND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THROUGH SUNRISE...EARLY MORNING SURFACE ANALYSIS SHOWED A WEAK
SURFACE TROUGH EXTENDING ACROSS CENTRAL GEORGIA INTO THE NORTHERN
MIDLANDS. THE LATEST RUNS OF THE RAP AND NSSL WRF MODELS SHOW
ISOLATED CONVECTION FIRING ALONG THE TROUGH OVER THE NEXT FEW
HOURS AS SHORTWAVE ENERGY MOVING THROUGH EASTERN KENTUCKY MOVES
CLOSER. ALREADY SEEING A FEW CLUSTERS OF TSTMS FIRING ACROSS THE
NORTH CAROLINA FOOTHILLS...SO IT IS CERTAINLY CONCEIVABLE THAT A
TSTMS OR TWO COULD POP ACROSS THE MIDLANDS AND DRIFT INTO THE
WESTERN ZONES PRIOR TO SUNRISE. ATTM IT APPEARS THE CHANCES FOR
MEASURABLE RAINFALL WILL REMAIN LESS THAN 20 PERCENT SO WILL KEEP
MENTIONABLE POPS OUT OF FORECAST FOR NOW AND MONITOR TRENDS
CAREFULLY. MORNING LOWS FROM THE LOWER 70S WELL INLAND TO AROUND
80 AT THE BEACHES LOOK ON TRACK.
TODAY...THE EVOLUTION OF AFTERNOON CONVECTION WILL MIRROR A
TYPICAL MID-LATE SUMMER CONVECTIVE PATTERN TODAY WHERE OUTFLOW
BOUNDARIES GENERATED BY ISOLATED SEA BREEZE TSTMS EVENTUALLY
INTERSECT OUTFLOWS GENERATED BY UPSTREAM CONVECTION TO SPARK
SCATTERED CONVECTIVE CLUSTERS ACROSS INLAND AREAS. THE NAM/S
SOLUTION SHOWING SOME SHORT OF MESOSCALE CONVECTIVE SYSTEM /MCS/
PLOWING THROUGH SOUTHEAST GEORGIA LOOKS SOMEWHAT SPURIOUS AND IS
NOT SUPPORTED BY ANY OF THE OTHER VARIOUS MESOSCALE OR GLOBAL
MODELS ATTM. WILL MAINTAIN A 20-30 PERCENT POPS REGIME WITH THE
HIGHEST GRIDDED POPS CENTERED ROUGHLY ALONG AND WEST OF THE I-95
CORRIDOR. HIGHER SHORT-TERM POPS MAY EVENTUALLY BE NEEDED LATER
TODAY...ESPECIALLY IF MESOSCALE PROCESSES TAKE HOLD...BUT THIS IS
NEARLY IMPOSSIBLE TO PIN DOWN THIS FAR OUT. HIGHS WILL RANGE FROM
THE MID 90S INLAND TO THE MID 80S AT THE BEACHES.
MODIFIED RAP BUFR SOUNDINGS SHOW DCAPES RISING TO NEAR 1300 J/KG
BY EARLY AFTERNOON WITH TOTAL TOTALS NEARING 55 UNITS AND
SHOWALTER INDICES DROPPING TO NEAR -3C. THIS COUPLED WITH DELTA
EPT/S APPROACHING +30C SUGGEST THERE WILL BE A SLIGHTLY HIGHER RISK
FOR DAMAGING WINDS WITH THE STRONGER TSTMS TODAY. THE RISK FOR
PULSE SEVERE TSTMS WILL BE HIGHEST NEAR MESOSCALE BOUNDARY
INTERACTIONS WITHIN A WEAK 0-6KM BULK SHEAR REGIME. A MENTION FOR
ISOLATED SEVERE TSTMS WILL BE PLACED IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
ANY LINGERING CONVECTION WILL DIMINISH BY MID-EVENING AS
INSOLATION WANES AND THE SEA BREEZE CLEARS THE WESTERN ZONES.
EXPECT A DRY NIGHT TO PREVAIL...ALTHOUGH AN ISOLATED SHOWER/TSTM
COULD POPS JUST ABOUT ANYWHERE WITH RESIDUAL OUTFLOWS LIKELY
LURKING ABOUT. DEBRIS CLOUDINESS WILL THIN WITH MOSTLY CLEAR SKIES
DOMINATING FOR MUCH OF THE OVERNIGHT PERIOD. LOWS WILL RANGE FROM
THE LOWER 70S WELL INLAND TO AROUND 80 AT THE BEACHES.
THE FORECAST AREA WILL BECOME POSITIONED BETWEEN A SURFACE HIGH
PRESSURE TO THE WEST AND A SUBTROPICAL HIGH PRESSURE TO THE EAST.
HEIGHTS WILL CONTINUE TO INCREASE THROUGH THE WEEKEND WITH MODEST
UPPER LEVEL RIDGING BUILDING ALONG THE EAST COAST. A PERSISTENT
SOUTHERLY FLOW WILL ALLOW PLENTY OF DEEP MOISTURE TO CONTINUOUSLY
ADVECT OVER THE AREA. MODEL SOUNDINGS VERIFY THIS DEEP MOISTURE WITH
PWATS REMAINING STEADY AROUND 2 INCHES THROUGH THE WEEKEND.
THUS...EXPECT ISOLATED TO SCATTERED CONVECTION TO DEVELOP FAIRLY
EASILY EACH AFTERNOON AS THE SEA BREEZE PROPAGATES INLAND AND
CONVECTIVE TEMPERATURES ARE REACHED. WITH HIGH TEMPERATURES EXPECTED
TO REACH THE LOW TO MID 90S EACH AFTERNOON...CONVECTIVE TEMPS IN THE
UPPER 80S WILL NOT BE DIFFICULT TO EXCEED. STILL...INSTABILITY
PARAMETERS ARE LESS THAN IMPRESSIVE WITH SHOWALTER INDICES
GENERALLY POSITIVE AND LAPSE RATES BETWEEN 5 AND 6 C/KM.
THEREFORE...THE SEVERE POTENTIAL APPEARS LOW...BUT CAN NOT RULE OUT
ONE OR TWO ISOLATED STRONG TO SEVERE STORMS. ANY STRONG STORMS WILL
LIKELY DEMONSTRATE TRADITIONAL SUMMERTIME PULSE CHARACTERISTICS. ANY
LINGERING CONVECTION WILL QUICKLY DIMINISH AFTER SUNSET...WITH
OVERNIGHT LOWS EXPECTED TO REMAIN QUITE MILD IN THE MID TO LOW 70S INLAND
AND UPPER 70S ALONG THE BEACHES.
&&
.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY/...
MODELS SHOW SUBTLE HIGH FALLS AT THE BEGINNING OF THE PERIOD AS A
LOW PRESSURE SYSTEM MOVES EASTWARD ACROSS THE NEW ENGLAND AREA. ITS
ASSOCIATED COLD FRONT WILL LIKELY STALL OUT WELL NORTH OF THE AREA
SOMETIME AROUND MID WEEK. MEANWHILE...THE UPPER RIDGE ACROSS CENTRAL
UNITED STATES WILL CONTINUE TO STRENGTHEN THROUGH THE PERIOD. AT THE
SURFACE...THE FORECAST AREA WILL REMAIN SANDWICHED BETWEEN THE
SURFACE HIGH PRESSURE OVER THE MIDDLE OF THE UNITED STATES AND THE
SUBTROPICAL HIGH JUST TO THE EAST. THIS PATTERN COULD ALLOW FOR AN
INCREASE IN CONVECTION...ESPECIALLY AS CONVECTION DEVELOPS ALONG THE
STALLED FRONT AND INTERACTS WITH OTHER BOUNDARIES...LIKE THE SEA
BREEZE. TEMPERATURES WILL CONTINUE TO REFLECT NEAR SEASONAL NORMALS
WITH LOW TO MID 90S EXPECTED DURING THE AFTERNOON AND DIPPING INTO
THE LOW TO MID 70S OVERNIGHT.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
VFR FOR THE NEXT 24 HOURS. COULD SEE SOME GROUND FOG DEVELOP AT
EITHER KCHS/KSAV GIVEN MOIST LOW-LEVEL PROFILES UNDER A LIGHT WIND
REGIME. ANY REDUCTIONS WILL GENERALLY BE CONFINED TO AN HOUR OR
TWO PRIOR TO SUNRISE. LOW PROBABILITIES FOR TSTMS THIS AFTERNOON
AT BOTH TERMINALS. CHANCES TO LOW TO JUSTIFY ANY MENTION THIS FAR
OUT.
EXTENDED AVIATION OUTLOOK...MVFR CIGS/VSBYS POSSIBLE THURSDAY
AFTERNOON/EVENING WITH SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A BROAD SOUTHERLY FLOW REGIME WILL REMAIN IN TACT ACROSS THE WATERS
THROUGH TONIGHT. WINDS WILL REMAIN 10-15 KT WITH SEAS 2-4 FT.
ATLANTIC HIGH PRESSURE WILL PREVAIL ACROSS THE MARINE AREA THROUGH
EARLY NEXT WEEK. THIS PATTERN WILL CONTINUE TO RESULT IN CONDITIONS
BELOW SMALL CRAFT CRITERIA. IN GENERAL...SOUTH/SOUTHWEST WINDS
BETWEEN 10 TO 15 KNOTS WILL PERSIST ON THE WESTERN SIDE OF THE
ATLANTIC RIDGE WITH BRIEF INCREASES OF 15 TO 20 KNOTS...MAINLY
DURING NOCTURNAL SURGING. SEAS WILL ALSO REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA THROUGH THE PERIOD...BUT EXPECT BRIEF INCREASES
DURING TIMES OF STRONGER WINDS. GENERALLY...SEAS WILL REMAIN 2 TO 3
FEET WITHIN 20 NM AND NO MORE THAN 5 FEET FURTHER OUT.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
204 AM EDT THU AUG 2 2012
.PREV DISCUSSION...
UPDATE...
/ISSUED 956 PM EDT WED AUG 1 2012/
ISOLATED STRONG TO SEVERE STORM POTENTIAL CONTINUES ACROSS THE
NORTHERN TIER OF THE FORECAST AREA EARLY TONIGHT. SPC ALSO UPDATED
TO INCLUDE PART OF THIS AREA IN A SLIGHT RISK...HOWEVER THE
MAJORITY OF THE MORE INTENSE DEVELOPMENT HAS PASSED. SEVERAL
CLUSTERS OF CONVECTION NEAR A SFC BOUNDARY HAVE BEEN TRACKING
SEWD FROM SOUTHERN TN AND THE HRRR HAS THIS DEVELOPMENT PERSISTING
FARTHER SOUTH UNTIL JUST NORTH OF ATLANTA BY NEAR 06Z. PER
OBSERVED DEWPOINT DEPRESSIONS AHEAD OF THE STORMS AND RECENT
SOUNDING DATA...THE LOW LEVELS ARE QUITE DRY AND STORM DEVELOPMENT
IS LIKELY ELEVATED. LARGE HAIL AND DAMAGING WINDS HAVE BEEN THE
MAIN CONCERNS...HOWEVER SOME CELLS HAVE SHOWN ROTATION ALBEIT ONLY
OBSERVABLE ABOUT 6KFT AGL. ADJUSTED POPS TO LIKELY AND CHANCE IN
THE NORTH BEFORE MIDNIGHT AND THEN SLIGHT TO NO CHANCE THE REST OF
THE OVERNIGHT. MADE OTHER ADJUSTMENTS TO TEMP AND DEWPOINT
TRENDS...BUT DID NOT AFFECT OVERNIGHT MINS. PREVIOUS DISCUSSION
FOLLOWS...
03
PREV DISCUSSION...
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
/ISSUED 252 PM EDT WED AUG 1 2012/
CURRENT SATELLITE LOOP SHOW MOSTLY CLEAR SKIES OVER THE AREA. THERE
IS SOME CU BEGINNING TO DEVELOP ACROSS WEST AND CENTRAL GA SO THIS
LOOKS LIKE IT COULD BE THE BEGINNING OF SOME ISOLATED SHRA/TSRA THIS
AFTERNOON/EVENING. THERE IS A WEAK STATIONARY BOUNDARY OVER N GA
THAT MAY ACT AS A FOCUSING MECHANISM FOR THUNDERSTORM DEVELOPMENT.
THE KEY IS GOING TO BE JUST HOW MUCH DRIER AIR HAS FILTER INTO THE
AREA UNDER THE WEAK RIDGE BUILDING IN FROM THE NORTH AND HOW STRONG
IS THE INSTABILITY ACROSS THE AREA. LOOKS LIKE WE WILL SEE SOME
ISOLATED TO SCATTERED SHRA/TSRA DEVELOP ACROSS NORTH GA BUT IT
SHOULD DISSIPATE OUT SHORTLY AFTER SUNSET. MOISTURE INCREASES SOME
THURSDAY FROM THE NORTH AS THE RIDGE BREAKS DOWN A BIT MORE THROUGH
THE END OF THE WEEK. TEMPS WILL STAY NEAR SEASONAL NORMS THROUGH THE
SHORT TERM.
01
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
/ISSUED 252 PM EDT WED AUG 1 2012/
UPPER LEVEL HIGH PRESSURE RIDGE REMAINS SITUATED OVER TEXAS
INTO THE EXTENDED PERIOD...WITH NORTHWEST FLOW PREVAILING ACROSS
THE TENNESSEE VALLEY AND INTO GEORGIA. THIS FLOW WILL CONTINUE TO
USHER UPPER LEVEL DISTURBANCES INTO THE REGION INTO THE WEEKEND.
THESE FEATURES...COMBINED WITH AMPLE DAYTIME HEATING WILL KEEP
SLIGHT CHANCE TO CHANCE THUNDERSTORMS ACROSS THE AREA. INTO EARLY
NEXT WEEK...HIGH PRESSURE RIDGE OVER THE ATLANTIC BECOMES MORE
DOMINANT ACROSS THE SOUTHEAST AS LOW PRESSURE DEEPENS OVER SOUTH
CENTRAL CANADA. THIS LOW WILL DRAG A FRONTAL BOUNDARY THROUGH THE
TENNESSEE VALLEY BY MONDAY MORNING...AND PUSH INTO NORTHWEST
GEORGIA BY MONDAY AFTERNOON. TIMING OF THIS SYSTEM AS IT PUSHES
THROUGH DIFFERS SLIGHTLY BY MODEL...SO HAVE MADE NO MAJOR
ADJUSTMENTS TO THE CURRENT FORECAST BASED ON THE UNCERTAINTY. HIGH
PRESSURE BUILDS BACK INTO THE REGION BEHIND THE FRONT...AND
ANTICIPATE DIURNALLY DRIVEN CONVECTION TO RETURN BY MID WEEK.
PREVIOUS FORECAST CONTINUES TO APPEAR ON TRACK...AND HAVE ADDED
THE PREVIOUS DISCUSSION BELOW...
31
/ISSUED 438 AM EDT WED AUG 1 2012/
LITTLE CHANGE IN THE PATTERN...HENCE THE SCATTERED AFTERNOON AND
EVENING THUNDERSTORMS TO CONTINUE.
UPPER LEVEL LOW REMAINS OVER TEXAS AS STORM SYSTEM RIDE OVER THE
TOP THROUGH THE PLAINS AND OHIO VALLEY. THE HIGH OFF THE COAST
CONTINUES TO HOLD A WARM MOIST AIR MASS OVER THE SOUTHEAST...
THOUGH THE GFS MAINTAINS A HIGHER MEAN RH OVER THE AREA THAN DOES
THE ECMWF. THE GFS SOLUTION PREFERRED. SUNDAY NIGHT INTO MONDAY
THEY BOTH HAVE A COLD FRONT MOVING THROUGH EASTERN TENNESSEE AND
INTO NORTHERN GEORGIA MONDAY MORNING. IT SETTLES INTO
CENTRAL/SOUTH GEORGIA AND WEAKENS BY TUESDAY...BUT PLENTY OF MOISTURE
REMAINS OVER THE AREA TO CONTINUE THE AFTERNOON AND EVENING
THUNDERSTORMS. LIKEWISE...SEE NO CHANGE IN THE TEMPERATURES
THROUGH THE PERIOD.
37
&&
.AVIATION...
06Z UPDATE...
VFR THROUGH THE PERIOD...EXCEPT FOR MVFR MORNING HAZE/FOG
POSSIBLE AT SOME SITES. SOUTHWESTERLY WINDS STRUGGLING TO REACH 10
KTS...WITH LIGHT VARIABILITY AT NIGHT FOR MOST SITES. CONVECTION
MENTIONABLE IN THE AFTERNOON AT ALL SITES.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE FOR CONVECTION THURSDAY...
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
PREFERRED GFS SLIGHTLY OVER THE NAM.
RAG
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 94 73 94 71 / 40 20 20 30
ATLANTA 95 75 91 73 / 30 20 30 30
BLAIRSVILLE 88 67 85 67 / 20 20 30 50
CARTERSVILLE 96 72 92 70 / 30 20 30 40
COLUMBUS 97 76 93 73 / 30 20 20 20
GAINESVILLE 93 75 92 71 / 40 20 30 40
MACON 97 73 93 71 / 30 20 20 20
ROME 96 72 94 71 / 20 20 40 40
PEACHTREE CITY 94 71 90 69 / 30 20 20 20
VIDALIA 97 76 95 73 / 30 20 20 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RAG
LONG TERM....37
AVIATION...RAG
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
516 PM CDT THU AUG 2 2012
.DISCUSSION...
308 PM CDT
THE MAIN CONCERNS DURING THE FORECAST PERIOD ARE CONVECTIVE CHANCES
AND TIMING...ESPECIALLY ON SATURDAY AFTERNOON AND NIGHT...ALONG WITH
THE WARM TEMPERATURES FRIDAY AND SATURDAY.
A WEAK AND ILL DEFINED COOL FRONTAL BOUNDARY HAS DROPPED ACROSS
SOUTHERN WISCONSIN THIS AFTERNOON. THE CONVECTIVE THREAT ACROSS FAR
NORTHERN ILLINOIS LATE THIS AFTERNOON CONTINUES TO LOOK VERY LOW.
THE CLOUD COVER SHOWN ON REGIONAL SATELLITE IMAGERY ACROSS NORTHERN
ILLINOIS DOES NOT HAVE MUCH OF A CONVECTIVE LOOK TO IT. IN
ADDITION...AN AMDAR SOUNDING OUT OF MDW INDICATES THAT INSTABILITY
IS VERY WEAK. SO IT APPEARS THE AREA WILL LIKELY REMAIN DRY.
TONIGHT INTO FRIDAY...THE MODEL GUIDANCE IS INDICATING THAT SEVERAL
MID LEVEL SHORT WAVE PERTURBATIONS WILL BE EJECTED EASTWARD ACROSS
THE LOWER MISSOURI AND MID MISSISSIPPI VALLEYS WITHIN THE STRONG
WESTERLIES ACROSS THE PLAINS AND UPPER MIDWEST. THE STRONGEST OF
THESE DISTURBANCES...CURRENTLY ACROSS KANSAS AND NORTHWESTERN
MISSOURI...WILL MOVE EAST SOUTHEASTWARD ACROSS DOWNSTATE ILLINOIS
AND ACROSS THE SOUTHERN APPELLATIONS TONIGHT INTO FRIDAY. THIS WILL
LIKELY FOCUS MOST OF THE CONVECTION SOUTH OF THE AREA DURING THIS
PERIOD. HOWEVER...IT APPEARS THAT A SURFACE WARM
FRONT/TROUGH...ASSOCIATED WITH A WEAK SURFACE WAVE ACROSS THE
PLAINS...WILL BE IN PLACE ACROSS NORTHERN ILLINOIS ON FRIDAY. MODEL
BUFFER SOUNDINGS ACROSS THE REGION ON FRIDAY DO INDICATE AN INCREASE
IN INSTABILITY AS BETTER BOUNDARY LAYER MOISTURE GETS TRANSPORTED
NORTHWARD. OVERALL THIS DOES NOT LOOKS LIKE A GOOD SETUP FOR
WIDESPREAD CONVECTION AS MOST OF THE LARGER SCALE SUPPORT WILL BE
WELL TO THE SOUTH OF THE AREA. HOWEVER...I CANT RULE OUT SOME ISOLATED
STORMS DEVELOPING ACROSS PORTIONS OF THE AREA DURING THE
AFTERNOON...ESPECIALLY WITH A LOW LEVEL BOUNDARY/CONVERGENCE ZONE IN
PLACE. MOST MODEL GUIDANCE KEEPS THE AREA DRY...BUT SOME OF THE
CONVECTIVE ALLOWING MODELS DO ALLOW SOME ISOLATED ACTIVITY TO
DEVELOP ACROSS PORTIONS OF THE AREA. WITH THIS IN MIND...I WILL CONTINUE
TO MENTION THE SLIGHT CHANCE POPS FOR FRIDAY INTO FRIDAY
NIGHT...MAINLY SOUTH OF INTERSTATE 80.
FINALLY LATER SATURDAY AND SATURDAY NIGHT THE STRONG SHORT WAVE
TROUGH IS EXPECTED TO MOVE ACROSS THE DAKOTAS EASTWARD ACROSS THE
UPPER GREAT LAKES. AT THE SURFACE...A POTENT AREA OF LOW PRESSURE
WILL LIKELY DRIVE A COLD FRONT ACROSS NORTHERN ILLINOIS SOMETIME
SATURDAY EVENING AND ACROSS NORTHWESTERN INDIANA OVERNIGHT. THERE
CONTINUES TO BE SOME UNCERTAINTY WITH THE TIMING OF THIS SYSTEM AS
THE GFS ENSEMBLES STILL SHOW SOME DECENT SPREAD. IN SPITE OF THESE
TIMING DIFFERENCES...THIS STILL PROMISES TO PRODUCE BY FAR THE BEST
POTENTIAL FOR THUNDERSTORMS ACROSS THE AREA DURING THE FORECAST
PERIOD. IT CURRENTLY APPEARS THE BEST CHANCES FOR THUNDERSTORMS WILL
BE SATURDAY NIGHT. THERE IS ALSO A POTENTIAL FOR A SEVERE THREAT AS
WELL SATURDAY NIGHT. HOWEVER...THERE REMAINS QUESTIONS AS TO WHETHER OR
NOT THE STRONGER MID LEVEL FLOW WILL COINCIDE WITH THE UNSTABLE
AIRMASS...OR IF IT WILL LAG BEHIND THE FRONT.
TEMPERATURES FRIDAY AND SATURDAY WILL CONTINUE TO BE IN THE 90S. I
AM CONCERNED THAT WE WILL BE FLIRTING WITH HEAT ADVISORY CRITERIA
ACROSS MUCH OF THE AREA ON SATURDAY. MOISTURE SHOULD INCREASE
SUBSTANTIALLY ON SATURDAY AHEAD OF THE APPROACHING COLD FRONT.
SURFACE DEW POINTS LOOK TO CLIMB INTO THE LOW 70S DURING THE DAY.
THIS COMBINED WITH TEMPERATURES IN THE MID TO PERHAPS UPPER 90S IN A
FEW AREAS...LOOKS TO PRODUCE HEAT INDICES AROUND 105 DEGREES.
MUCH COOLER AND DRIER WEATHER MOVES ACROSS THE AREA FOR SUNDAY INTO
NEXT WEEK.
KJB
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* WIND DIRECTIONS INTO FRIDAY MORNING.
TRS
//DISCUSSION...UPDATED 22Z...
LAKE BREEZE HAS CONTINUED TO PUSH WELL INLAND TO WRN MCHENRY...NW
KANE W CNTRL DUPAGE COUNTIES DURING THE MID-LATE AFTERNOON BUT
MORE SLOWLY ACROSS SE DUPAGE AND SRN COOK INTO NRN LAKE COUNTY AS
950HPA VAD WINDS AT KLOT AND TMDW SHOWING ESE AROUND 10KT WHILE
TMDW AND TMKE SHOWING E TO ENE 10-15KT. 20Z AND 21Z RUC13 RUNS
DEPICTING VERY SHORT TERM WINDS WELL MAINTAINING E-ENE 10-15 KT
SFC WINDS AT ORD SO HAVE FOLLOWED THIS OUTPUT.
TRS
PREVIOUS 18Z DISCUSSION...
WIND DIRECTIONS WILL REMAIN PROBLEMATIC INTO FRIDAY MORNING DUE
TO A FAIRLY WEAK GRADIENT AND POTENTIAL FOR A LAKE BREEZE THIS
AFTERNOON. WEAK HIGH PRESSURE WILL MOVE EAST ACROSS THE OHIO
VALLEY THIS AFTERNOON AS WEAK LOW PRESSURE OVER NORTHERN MISSOURI
SLOWLY DRIFTS EAST/NORTHEAST TONIGHT INTO FRIDAY MORNING. IN
BETWEEN THESE TWO FEATURES...THE WINDS HAVE BECOME LIGHT AND VRB
AND EVEN CALM ACROSS THE AREA. LOW LEVEL WINDS ALSO ARE FAIRLY
LIGHT AND EXPECT A LAKE BREEZE TO DEVELOP. WHETHER ITS THE LAKE
BREEZE ITSELF OR A COMBINATION WITH THE GRADIENT...EXPECT WINDS TO
TURN SOUTHEASTERLY EARLY THIS AFTERNOON AND MORE EAST/SOUTHEAST BY
MID/LATE AFTERNOON. HAVE KEPT LAKE BREEZE TIMING UNCHANGED BUT
WILL NEED TO MONITOR THROUGH THE EARLY AFTERNOON. GRADIENT REMAINS
LIGHT OVERNIGHT AND EXPECT PERIODS OF LIGHT AND VARIABLE WINDS
THOUGH ANY PREVAILING WINDS LIKELY TO BE EAST/SOUTHEASTERLY...
ESPECIALLY TOWARD MORNING. GRADIENT TIGHTENS UP ENOUGH FOR MAINLY
EASTERLY WINDS UP TO 10KTS ON FRIDAY...POSSIBLY TURNING A BIT MORE
NORTHEASTERLY IN THE AFTERNOON.
GUIDANCE CONTINUES TO HINT AT SOME LIGHT FOG/HAZE FRIDAY MORNING.
GIVEN THE RELATIVELY DRY GROUND CERTAINLY NOT EXPECTING ANYTHING
TOO LOW OR WIDESPREAD BUT GIVEN THE LIGHT WINDS IF TEMPS CAN FALL
OFF TO THE DEWPOINTS...COMBINED WITH THE LIGHT WINDS...THERE COULD
BE SOME PATCHY/GROUND FOG.
WITH THE WEAK LOW EXPECTED TO PASS SOUTH OF THE TERMINALS ON
FRIDAY...EXPECT ANY PRECIP/CONVECTION TO ALSO REMAIN SOUTH OF THE
TERMINALS BUT SOME ISOLATED ACTIVITY IN THE AFTERNOON IS POSSIBLE
BUT CONFIDENCE AND EXPECTED COVERAGE TOO LOW TO INCLUDE IN THIS
FORECAST. CMS
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH CONFIDENCE IN WIND TRENDS THROUGH EARLY EVENING.
* HIGH CONFIDENCE IN OTHER FORECAST ELEMENTS WITH NO SIG WX TO
OCCUR.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...VFR. SLGT CHANCE TSRA/SHRA INCREASING TO CHANCE IN THE
AFTERNOON. PERIODS MVFR/IFR PSBL.
SUNDAY THROUGH WEDNESDAY...VFR.
JEE
&&
.MARINE...
243 PM CDT
AN AREA OF LOW PRESSURE CENTERED ACROSS FAR SOUTHWEST QUEBEC
CONTINUES TO WEAKEN AND DRIFT NORTHEAST...WITH A TRAILING FRONTAL
BOUNDARY STRETCHING WEST/SOUTHWEST THROUGH NORTHERN MICHIGAN INTO
NORTHERN WISCONSIN. THIS BOUNDARY IS EXPECTED TO DRIFT SOUTH
ACROSS LAKE MICHIGAN THIS EVENING...WITH WINDS TURNING
NORTH/NORTHEAST ACROSS NORTHERN LAKE MICHIGAN. MEANWHILE AN AREA
OF HIGH PRESSURE OVER WESTERN ONTARIO WILL CONTINUE TO PUSH EAST
ACROSS ONTARIO...AS THE FRONTAL BOUNDARY OVER LAKE MICHIGAN SLOWLY
ERODES. ANOTHER AREA OF LOW PRESSURE IS EXPECTED TO DEVELOP ACROSS
THE WESTERN DAKOTAS FRIDAY NIGHT...THEN STRENGTHEN AS THIS LOW
PRESSURE SLIDES EAST ACROSS THE UPPER MIDWEST AND LAKE SUPERIOR
SATURDAY AFTERNOON. THE PRESSURE GRADIENT IS EXPECTED TO TIGHTEN
ALONG THIS AREA OF LOW PRESSURE SAT NIGHT FOR CENTRAL/NORTHERN
LAKE MICHIGAN AND COULD BE TIGHT ENOUGH TO CREATE OCCASIONAL GALE
FORCE GUSTS SUNDAY. THEN THE FRONTAL BOUNDARY PUSHES EAST OF LAKE
MICHIGAN SUNDAY AND BROAD HIGH PRESSURE THEN BUILDS IN FOR EARLY
NEXT WEEK...WITH SEVERAL PERIODS OF LIGHT FLOW FROM THE NORTH TO
NORTHEAST.
BEACHLER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
642 PM CDT FRI AUG 3 2012
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING
THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED
COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY
FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST
FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY
ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME
REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND
HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE
DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD
SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT
HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT
CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE
AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY
IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED
SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY
ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR
PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP
IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL
NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO
MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS
THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK
EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE
EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY
LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY
EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT
LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE
CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS
SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE
FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS
CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE
FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS
NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE
FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID
80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO
90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE
DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN
ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS
MONDAY NIGHT ACROSS MUCH OF THE CWA.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK
AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A
COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN
COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING.
READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT
NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY.
SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK
SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH
THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST
FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE
INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW
CONTINUING BEYOND THE FORECAST PERIOD.
&&
.AVIATION...04/00Z
CDFNT FROM ERN ND INTO THE SWRN NEBRASKA PNHDL WILL MOVE INTO IA
TONIGHT AND PASS SOUTHEAST OF THE TAF SITES BY MID AFTERNOON SAT.
STRONG LINE OF TSRA ALONG THE FRONT THIS EVENING WILL MOVE INTO NWRN
IA BY 08Z...BECOMING MORE SCATTERED AS THEY APPROACH THE NWRN TAF
SITES TOWARD 09Z. A FEW SHOWERS MAY REACH KDSM AFT SUNRISE.
ADDITIONAL TSRA DEVELOPMENT LIKE BY EARLY TO MID AFTERNOON OVER THE
EASTERN TAF SITES NEAR AND JUST BEHIND CDFNT. STRATO CU DECK IS
POSSIBLE OVER THE NWRN HALF OF THE STATE FOR SAT AFTERNOON. AT
THIS TIME AM NOT SURE IT ILL BE AS LOW AS MVFR AND HELD IT ABOVE 030.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MJB
LONG TERM...COGIL
AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS WICHITA KS
1240 PM CDT THU AUG 2 2012
.AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
WEAK PV ANOMALY WILL CONTINUE MOVING SLOWLY EASTWARD ACROSS SOUTH
CENTRAL/SOUTHEAST KS THIS AFTERNOON. THIS SHOULD ALLOW FOR
ISOLATED-WIDELY SCATTERED HIGH-BASED -SHRA/-TSRA TO PERSIST THIS
AFTERNOON. WILL MENTION VCSH AT HUT/ICT/SLN BASED ON LATEST RADAR
TRENDS. THERE WILL BE A SMALL CHANCE OF HIGH-BASED -TSRA TONIGHT
INTO FRIDAY MORNING ACROSS THE AREA...WITH HIGH PRECIPITABLE WATER
AXIS REMAINING ALONG WITH WEAKNESS AT 700 MB. CHANCES APPEAR TOO
LOW TO MENTION AT TAF SITES THIS FAR OUT ESPECIALLY GIVEN COVERAGE
CONCERNS. GUSTY WINDS POSSIBLE NEAR ANY STORM ACTIVITY GIVEN
TEMPERATURE-DEWPOINT SPREADS. OTHERWISE VFR TO PREVAIL.
JMC
&&
.PREV DISCUSSION... /ISSUED 800 AM CDT THU AUG 2 2012/
UPDATE...
WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL
AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY.
PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10
TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF
THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A
PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT
LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING
& ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED
ATTENTION WITH 00Z & 06Z TAF ISSUANCES.
PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/
DISCUSSION...
TODAY-TONIGHT:
ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS
NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY
CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND
EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN
EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS
PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF
DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT
FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START
PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH
DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN
REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST
ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400.
CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT
HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH
IT.
FRI-FRI NIGHT:
HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND
POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER
CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING
HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY
ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN
CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW...
COULD BE EVEN WARMER THAN FORECAST.
SAT-SUN:
GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD.
LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH
FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES
NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT...
WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN
NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER
THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN
SECTIONS.
MON-WED:
CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN
THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON
THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS
NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF
AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH.
INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH
MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED.
WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO
INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD.
-HOWERTON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO
RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS
FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU.
DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM
REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU
SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE
MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM
TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK
THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING
CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST
FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT
FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 107 78 104 78 / 20 20 10 10
HUTCHINSON 103 76 103 76 / 20 20 10 10
NEWTON 103 77 102 77 / 20 20 10 10
ELDORADO 104 77 104 77 / 20 20 10 10
WINFIELD-KWLD 111 80 106 80 / 20 20 10 10
RUSSELL 98 73 101 73 / 20 30 10 20
GREAT BEND 100 74 102 74 / 20 20 10 20
SALINA 98 76 102 75 / 20 30 10 20
MCPHERSON 101 75 103 75 / 20 30 10 20
COFFEYVILLE 110 79 106 79 / 20 20 10 10
CHANUTE 105 76 103 78 / 20 20 10 10
IOLA 103 77 102 77 / 20 20 10 10
PARSONS-KPPF 107 77 104 79 / 20 20 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING UNTIL 9 PM CDT THIS EVENING FOR KSZ069-
082-083-091>096-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1221 PM CDT THU AUG 2 2012
...UPDATE TO AVIATION...
.DISCUSSION...
ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN
WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH
HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH.
THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS
LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE
EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY.
NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD
COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER
ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH
AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY
COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH
FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW
THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT
AN ADVISORY.
FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT
REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE
AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE
POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT
FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE
POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE
MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST.
MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA
SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS
WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS
TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN
UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED
CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A
RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY.
FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT
THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN
INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON
THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING
UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING
OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW
UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS.
WOLTERS
&&
.AVIATION...
STILL OUTSIDE CHANCE FOR A SHOWER OR STORM AT ONE OF THE TERMINALS
THIS AFTERNOON THEN AGAIN OVERNIGHT...HOWEVER MOST GUIDANCE
SUGGEST STORMS TO STAY SOUTH. WITH BOUNDARY TO THE SOUTH HAVE NE
WINDS BLO 12KTS AND VFR CIGS...WILL WATCH FOR BR OVERNIGHT BUT
THINK RAIN AMOUNTS WERE LOW ENOUGH TO NEGATE THAT THREAT. 67
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
800 AM CDT THU AUG 2 2012
.UPDATE...
WITH THE -SHRA & -TSRA HAVING VACATED CNTRL & SE KS HAVE UPDATED ALL
AFFECTED PRODUCTS TO REMOVE THE MORNING MENTION OF THIS ACTIVITY.
&&
.PREV DISCUSSION... /ISSUED 653 AM CDT THU AUG 2 2012/
AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10
TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF
THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A
PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT
LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING
& ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED
ATTENTION WITH 00Z & 06Z TAF ISSUANCES.
PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/
DISCUSSION...
TODAY-TONIGHT:
ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS
NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY
CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND
EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN
EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS
PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF
DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT
FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START
PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH
DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN
REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST
ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400.
CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT
HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH
IT.
FRI-FRI NIGHT:
HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND
POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER
CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING
HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY
ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN
CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW...
COULD BE EVEN WARMER THAN FORECAST.
SAT-SUN:
GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD.
LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH
FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES
NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT...
WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN
NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER
THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN
SECTIONS.
MON-WED:
CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN
THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON
THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS
NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF
AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH.
INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH
MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED.
WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO
INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD.
-HOWERTON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO
RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS
FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU.
DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM
REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU
SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE
MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM
TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK
THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING
CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST
FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT
FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 107 78 104 78 / 20 20 10 10
HUTCHINSON 104 76 103 76 / 20 20 10 10
NEWTON 103 77 102 77 / 20 20 10 10
ELDORADO 104 77 104 77 / 20 20 10 10
WINFIELD-KWLD 111 80 106 80 / 20 20 10 10
RUSSELL 99 73 101 73 / 20 30 10 20
GREAT BEND 101 74 102 74 / 20 20 10 20
SALINA 99 76 102 75 / 20 30 10 20
MCPHERSON 102 75 103 75 / 20 30 10 20
COFFEYVILLE 110 79 106 79 / 20 20 10 10
CHANUTE 105 76 103 78 / 20 20 10 10
IOLA 103 77 102 77 / 20 20 10 10
PARSONS-KPPF 107 77 104 79 / 20 20 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING
FOR KSZ069-082-083-091>094-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
654 AM CDT THU AUG 2 2012
...UPDATE TO AVIATION...
.DISCUSSION...
ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN
WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH
HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH.
THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS
LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE
EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY.
NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD
COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER
ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH
AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY
COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH
FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW
THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT
AN ADVISORY.
FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT
REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE
AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE
POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT
FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE
POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE
MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST.
MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA
SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS
WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS
TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN
UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED
CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A
RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY.
FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT
THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN
INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON
THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING
UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING
OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW
UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS.
WOLTERS
&&
.AVIATION...
LINGERING CONVECTION ON THE SOUTH SIDE OF MCV OVER THE NORTHERN
CWA WILL KEEP BKN AREA OF CONVECTION IN THE KTOP/KFOE SITES
THROUGH 13Z...THEN GRADUALLY ENDING....ALTHOUGH GUSTY NORTH WINDS
WILL PERSIST UNTIL 14Z-16Z TIME FRAME. MAIN AREA OF CONVECTION
SHOULD BE EAST OF THE KMHK SITE BY 12Z BUT SHOWERS LINGERING
THROUGH 13Z BEFORE ENDING. MVFR/BRIEF IFR VSBYS POSSIBLE IN ANY
THUNDERSTORMS UNTIL 13Z...BUT CIGS SHOULD GENERALLY BE VFR.
FOLLOWING CONVECTION THIS MORNING...REMAINDER OF THE TAFS WILL BE
VFR AND DRY...ALTHOUGH MORE CONVECTION CANNOT BE RULED OUT AFTER
06Z TONIGHT...BUT CONFIDENCE IS TOO LOW TO INCLUDE IN THE TAFS AT
THIS POINT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
653 AM CDT THU AUG 2 2012
.AVIATION...12Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
FOCUS THROUGH ~15Z IS ON OUTFLOW-INDUCED N/NE WINDS RANGING FROM 10
TO 20 KTS SUSTAINED WITH GUSTS TO ~30 KTS IN THE IMMEDIATE WAKE OF
THE BOUNDARY. QUIET WEATHER ANTICIPATED FOR REST OF THE DAY WITH A
PREDOMINANTLY E/NE WIND <=10KTS IN MOST AREAS. WITH THE SFC FRONT
LURKING ABOUT THE PREMISES A FEW TSRA REMAIN POSSIBLE THIS EVENING
& ESPECIALLY LATE TONIGHT OVER CNTRL KS. THIS WILL DRAW INCREASED
ATTENTION WITH 00Z & 06Z TAF ISSUANCES.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT THU AUG 2 2012/
DISCUSSION...
TODAY-TONIGHT:
ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS
NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY
CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND
EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN
EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS
PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF
DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT
FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START
PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH
DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN
REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST
ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400.
CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT
HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH
IT.
FRI-FRI NIGHT:
HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND
POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER
CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING
HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY
ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN
CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW...
COULD BE EVEN WARMER THAN FORECAST.
SAT-SUN:
GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD.
LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH
FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES
NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT...
WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN
NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER
THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN
SECTIONS.
MON-WED:
CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN
THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON
THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS
NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF
AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH.
INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH
MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED.
WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO
INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD.
-HOWERTON
AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO
RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS
FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU.
DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM
REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU
SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE
MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM
TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK
THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING
CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST
FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT
FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 107 78 104 78 / 20 20 10 10
HUTCHINSON 104 76 103 76 / 20 20 10 10
NEWTON 103 77 102 77 / 20 20 10 10
ELDORADO 104 77 104 77 / 20 20 10 10
WINFIELD-KWLD 111 80 106 80 / 20 20 10 10
RUSSELL 99 73 101 73 / 20 30 10 20
GREAT BEND 101 74 102 74 / 20 20 10 20
SALINA 99 76 102 75 / 20 30 10 20
MCPHERSON 102 75 103 75 / 20 30 10 20
COFFEYVILLE 110 79 106 79 / 20 20 10 10
CHANUTE 105 76 103 78 / 20 20 10 10
IOLA 103 77 102 77 / 20 20 10 10
PARSONS-KPPF 107 77 104 79 / 20 20 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING
FOR KSZ069-082-083-091>094-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
343 AM CDT THU AUG 2 2012
.DISCUSSION...
ANOTHER MCS ROLLING ACROSS THE AREA THIS MORNING. THERE HAVE BEEN
WIDESPREAD WIND REPORTS OF 35 TO 50 MPH WITH THESE STORMS...WHICH
HAVE LAID DOWN AN IMPRESSIVE OUTFLOW BOUNDARY MOVING TO THE SOUTH.
THE LATEST HRRR HI RESOLUTION MODEL SHOWS THESE SHOWERS AND STORMS
LINGERING THROUGH THE MORNING HOURS ACROSS NORTHEAST KS. THEREFORE
EXPECT A SIMILAR AFFECT TO THE WEATHER THAT WAS SEEN YESTERDAY.
NAMELY SLIGHTLY COOLER WEATHER ACROSS NORTHERN COUNTIES DUE TO CLOUD
COVER AND THE INITIALLY COOL OUTFLOW. THINK THE AIRMASS WILL RECOVER
ENOUGH TO REACH THE MID AND UPPER 90S ACROSS NORTHERN COUNTIES WITH
AROUND 100 IN EAST CENTRAL KS. SINCE HIGHS SHOULD BE SLIGHTLY
COOLER...THERE IS UNCERTAINTY IN HEAT INDICES GETTING WARM ENOUGH
FOR A HEAT ADVISORY...AND WILL OPT TO LET THE DAY SHIFT MONITOR HOW
THE AIRMASS RECOVERS AND SEE IF HIGHS WILL GET HOT ENOUGH TO WARRANT
AN ADVISORY.
FOR TONIGHT THE MODELS SHOW WARM AIR ADVECTION AND ISENTROPIC LIFT
REDEVELOPING ACROSS CENTRAL KS AS POTENTIAL IMPULSES ROUND THE RIDGE
AND MOVE OFF THE HIGHER TERRAIN. THEREFORE HAVE SOME LOW CHANCE
POPS. CONFIDENCE IN LOCATION OF THE PRECIP IS MARGINAL...SO DO NOT
FEEL COMFORTABLE WITH HIGHER POPS AT THIS TIME. THERE IS THE
POTENTIAL FOR ANY NOCTURNAL CONVECTION TO AGAIN LINGER INTO THE
MORNING HOURS FRIDAY...AND THIS IS REFLECTED IN THE FORECAST.
MODELS ARE IN GOOD AGREEMENT WITH THE FRONT MOVING INTO THE AREA
SATURDAY. THE NAM AND GFS ARE SHOWING BETTER PVA AND FRONTOGENESIS
WITH THE BOUNDARY THAN EARLIER MODELS. HOWEVER THE NAM STILL APPEARS
TO BE SKITTISH WITH QPF. THINK WITH THE FRONT PROVIDING LIFT IN AN
UNCAPPED AIRMASS THAT THERE WILL BE AT LEAST A CHANCE FOR SCATTERED
CONVECTION...LASTING INTO SATURDAY NIGHT. THE FRONT WILL BRING A
RELATIVELY NICE COOL DOWN FOR THE AREA BY SUNDAY.
FOR SUNDAY THROUGH WEDNESDAY...HAVE NOT SPENT MUCH TIME LOOKING AT
THIS PERIOD DUE TO THE ONGOING CONVECTION. HOWEVER WITH THE PATTERN
INITIALLY AMPLIFYING EXPECT THE EARLY PART OF THE WEEK TO BE DRY ON
THE BACK SIDE OF THE DEPARTING SHORTWAVE. THERE IS INCREASING
UNCERTAINTY BY THE MIDDLE OF THE WEEK AS MODELS HAVE VARYING TIMING
OF ANOTHER FRONT MOVING INTO THE AREA. LEFT THE FORECAST DRY FOR NOW
UNTIL THERE IS BETTER CLUSTERING IN THE MODEL SOLUTIONS.
WOLTERS
&&
.AVIATION...
MAIN CONCERN FOR THE TAFS WILL BE THE TIMING AND AREAL COVERAGE OF
CONVECTION AS IT MOVES ACROSS NORTHEAST KANSAS. CIGS EXPECTED TO BE
VFR THROUGH THE PERIOD BUT MVFR VSBYS ARE POSSIBLE WITH TSRA.
CONVECTION SHOULD MOVE EAST OF THE TERMINALS BY 16Z. HAVE MAINTAINED
A MENTION OF VCTS ATTM.
53
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
333 AM CDT THU AUG 2 2012
.DISCUSSION...
TODAY-TONIGHT:
ANOTHER NIGHT WITH NOCTURNAL THUNDERSTORMS ROLLING ACROSS
NORTHERN KS AND SIGNIFICANT OUTFLOW PUSHING ACROSS THE AREA. ONLY
CHANGE IS A BIT MORE FAVORABLE UPPER DIFFLUENCE ACROSS NE KS AND
EXPECT STORMS TO PERSIST WELL INTO THE DAY...BUT SOUTHERN
EXTENT/PROPAGATION IS PROBLEMATIC. NAM APPEARS TO BE SHOWING BOGUS
PRECIPITATION IN PEAK HEATING SIMILAR TO THE PREVIOUS COUPLE OF
DAYS...BUT WITH SOME UPPER SUPPORT MIGHT FINALLY BE RIGHT ALBEIT
FOR THE WRONG REASON. WILL KEEP AFTERNOON DRY...BUT START
PRECIPITATION AT 2300 UTC. BOUNDARY WILL LIKELY DRIFT/MIX NORTH
DURING THE AFTERNOON. AFTERNOON HEAT INDICES SHOULD ONCE AGAIN
REACH ADVISORY CRITERIA ALONG SOUTHERN COUNTIES...AND WILL HOIST
ANOTHER EXCESSIVE HEAT WARNING FOR AREA SOUTH OF HIGHWAY 400.
CONFIDENCE IN SOUTHERN GREENWOOD COUNTY REACHING CRITERIA IS NOT
HIGH ENOUGH TO HOIST WARNING...ALTHOUGH SOUTHERN HALF MAY REACH
IT.
FRI-FRI NIGHT:
HEAT INDICES WILL PROBABLY TOP 105 IN THOSE SAME AREAS AGAIN...AND
POTENTIALLY IN CENTRAL KS WHERE SURFACE DEW POINTS POOL. HOWEVER
CONFIDENT GIVEN CONVECTIVE OUTFLOW/DEBRIS PRECLUDES EXTENDING
HEADLINES INTO THIS PERIOD. PRECIPITATION CHANCES LOOK SLIM EARLY
ON...WITH BETTER CHANCES AS FRONT APPROACHES AFTER MIDNIGHT IN
CENTRAL KS. IN ADBSENCE OF SIGNIFICANT CONVECTIVE DEBRIS/OUTFLOW...
COULD BE EVEN WARMER THAN FORECAST.
SAT-SUN:
GETTING A BIT UNEASY ABOUT PRECIPITATION CHANCES THIS PERIOD.
LATEST RUN SHOW LESS THAN FAVORABLE TIMING FOR PRECIPITATION WITH
FRONTAL PASSAGE SAT MORNING OVER MUCH OF THE AREA. BEST CHANCES
NOW APPEAR TO BE IN FAR SOUTHERN SECTIONS SAT AFTERNOON/NIGHT...
WITH LESSER CHANCES ON SUN. HAVE TRIMMED BACK MORE ON POPS SUN
NIGHT. PRECIPITATION/CLOUDS MAKE TEMPERATURES A TOUGH CALL...OTHER
THAN IT WILL LIKELY BE COOLER IN THE NORTH THAN IN THE SOUTHERN
SECTIONS.
MON-WED:
CONSIDERABLE UNCERTAINTY EVEN WITH THE 0000 UTC MODEL RUNS. EVEN
THOUGH THE LAST TWO ECMWF RUNS WERE FAIRLY SIMILAR...THIS IS ON
THE HEELS OF LARGE CHANGES WITH THE PRIOR TWO RUNS. AND THE GFS IS
NOT FAIRING MUCH BETTERN. SO DESPITE SOME ROUGH SEMBLANCE OF
AGREEMENT WITH THE 00Z MODEL RUNS...CONFIDENCE IS NOT VERY HIGH.
INTIAL THOUGHT IS TEMPERATURES WOULD BE EVEN WARMER...BUT BOTH
MODELS DO SUGGEST COOLER AIR COULD BACKDOOR INTO THE AREA ON WED.
WILL KEEP DRY FORECAST GOING FOR NOW AND STICK CLOSE TO
INITIALIZATION TEMPERATURES WHICH APPEAR TO BE MIDDLE OF THE ROAD.
-HOWERTON
&&
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO
RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS
FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU.
DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM
REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU
SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE
MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM
TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK
THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING
CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST
FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT
FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 107 78 104 78 / 20 20 10 10
HUTCHINSON 104 76 103 76 / 20 20 10 10
NEWTON 103 77 102 77 / 20 20 10 10
ELDORADO 104 77 104 77 / 20 20 10 10
WINFIELD-KWLD 111 80 106 80 / 20 20 10 10
RUSSELL 99 73 101 73 / 20 30 10 20
GREAT BEND 101 74 102 74 / 20 20 10 20
SALINA 99 76 102 75 / 20 30 10 20
MCPHERSON 102 75 103 75 / 20 30 10 20
COFFEYVILLE 110 79 106 79 / 20 20 10 10
CHANUTE 105 76 103 78 / 20 20 10 10
IOLA 103 77 102 77 / 20 20 10 10
PARSONS-KPPF 107 77 104 79 / 20 20 10 10
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
EXCESSIVE HEAT WARNING FROM NOON TODAY TO 9 PM CDT THIS EVENING
FOR KSZ069-082-083-091>094-098>100.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1155 PM MDT WED AUG 1 2012
.UPDATE...
ISSUED AT 808 PM MDT WED AUG 1 2012
MODIFIED THE EVENING AND OVERNIGHT FORECAST SLIGHTLY MAINLY TO
ACCOUNT FOR CURRENT CLOUD COVER AND PRECIPITATION COVERAGE AND TO
BLEND INTO OVERNIGHT TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 225 PM MDT WED AUG 1 2012
THROUGH TONIGHT...CONVECTION IS ONCE AGAIN EXPECTED TO DEVELOP
ACROSS THE PALMER DIVIDE REGION OF COLORADO WITH A GRADUAL SHIFT
EASTWARD WITH TIME. HRRR IS ALSO DEVELOPING CONVECTION ACROSS
NORTHWEST KANSAS BUT GIVEN LACK OF CU DEVELOPMENT OVER THIS
AREA...CONFIDENCE IS BELOW AVERAGE IN THIS SOLUTION. HAVING SAID
THAT...WILL MAINTAIN SLIGHT CHANCE POPS TO COVER THIS POTENTIAL. DID
BUMP POPS UP SLIGHTLY FOR THE LATE EVENING TIME FRAME WHEN
CONFIDENCE IS HIGHEST.
TRENDED OVERNIGHT LOWS UP OVER THE EAST SIMILAR TO WHAT WAS OBSERVED
THIS MORNING. OTHERWISE...LIGHT AND VARIABLE WINDS WITH A GRADUALLY
CLEARING SKY ARE EXPECTED.
THURSDAY...MAX TEMPS WILL BE SLIGHTLY COOLER AS COMPARED WITH TODAY
WITH HIGHS IN MOST LOCATIONS REMAINING IN THE MID 90S TO AROUND 100
DEGREES. POTENTIAL EXISTS ONCE AGAIN FOR CONVECTION DEVELOPING
DURING THE LATE AFTERNOON HOURS. GIVEN OBSERVED PWAT VALUES AROUND
135 PERCENT OF NORMAL...LOCALLY HEAVY RAINFALL WILL ONCE AGAIN BE A
THREAT. GUSTY OUTFLOW WINDS ALSO APPEAR TO BE POSSIBLE BASED ON
POINT SOUNDINGS FROM ACROSS THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 225 PM MDT WED AUG 1 2012
THURSDAY NIGHT-SATURDAY...FAIRLY ACTIVE WEATHER WILL CONTINUE
THROUGH THE PERIOD AS STRONG SHORT WAVE TROUGH DIVES INTO THE
NORTHERN PLAINS...FORCING STRONG COLD FRONT INTO THE TRI STATE AREA
FRIDAY NIGHT AND SATURDAY...BRINGING SOME RELIEF FROM THE HEAT TO
THE AREA BY SATURDAY AFTERNOON. NOT REAL CONFIDENT IN PRECIPITATION
CHANCES ON THURSDAY EVENING WITH MAIN STATIONARY FRONT WELL TO THE
SOUTH OF THE AREA AND LOW LEVEL FLOW BEING LIGHT AND GENERALLY
WESTERLY. HOWEVER...PERIOD OF LARGE SCALE ASCENT WILL MOVE JUST
NORTH OF THE CWA AND IF THE MUCH WEAKER CINH PROFILE OF THE NAM
VERIFIES...THAT MAY BE ENOUGH TO INITIATE AT LEAST A FEW STORMS
ALONG SFC TROUGH THAT EXTENDS INTO WESTERN CWA. GIVEN ABOVE CONCERNS
AND SREF DATA REALLY FOCUSING BEST CHANCES NEAR FRONT DO NOT THINK
OVERALL PATTERN REALLY WARRANTS MORE THAN 15-20 PERCENT. THINK BEST
CHANCES FOR PRECIPITATION WILL BE DURING THE OVERNIGHT HOURS ON
FRIDAY AS STRONG COLD FRONT SWEEPS ACROSS THE AREA...WHICH WILL NOT
ONLY BRING A PERIOD OF STRONG NEAR SFC ASCENT BUT A PERIOD OF DEEPER
ASCENT DEEP DIRECT CIRCULATION EXPECTED TO DEVELOP BEHIND FRONT
COLOCATED WITH AREA OF LARGE SCALE ASCENT AS PER Q VECTOR ANALYSIS.
WHILE FORCING WILL LIKELY BE THE STRONGEST ITS BEEN OUT OF THE PAST
SEVERAL DAYS...STILL A LARGE AMOUNT OF UNCERTAINTY WITH RESPECT TO
HOW MUCH INSTABILITY WILL BE AHEAD AND BEHIND FRONTAL ZONE AS
EVIDENCED BY LARGE DIFFERENCES BETWEEN GEFS AND SREF PROBABILISTIC
OUTPUT...AND THINK FOR THE TIME BEING THINK KEEPING POPS BELOW 50
PERCENT WARRANTED ATTM.
IN THE EXTENDED (SAT NIGHT-WEDNESDAY)...WHILE 06Z ROUND OF ENSEMBLES
SHOWED LITTLE SPREAD IN OVERALL PATTERN STARTING TO SEE A BIT MORE
UNCERTAINTY DEVELOP WITH RESPECT TO STRENGTH OF H5 RIDGE EXPECTED TO
DEVELOP OVER THE ROCKIES THROUGH THE MIDDLE OF NEXT WEEK. SOME
ENSEMBLES SEEM TO BE CLUSTERING TOWARDS BOTH THE MORE AMPLIFIED GFS
WITH THE OTHERS MORE IN THE ECMWF CAMP WHICH CERTAINLY LOWERS
CONFIDENCE IN TRYING TO PICK ONE MODEL OVER THE OTHER. FOR THE TIME
BEING...THINK CONSENSUS APPROACH THE BEST BET FOR HIGH TEMPS FOR THE
TIME BEING. TEMPERATURES WILL GRADUALLY WARM THROUGH THE
PERIOD...BUT WITH POSSIBILITY OF CWA BEING ON NORTHEAST SIDE OF A
FAIRLY AMPLIFIED RIDGE POTENTIAL FOR COOLER AIR BACKING INTO THE AREA
KEEPS CONFIDENCE TOO LOW TO MAKE LARGE DEVIATIONS FOR MAX TEMPS. FOR
LOWS...WITH SFC HIGH SETTLING OVER THE AREA ON SAT NIGHT BEHIND
STRONG COLD FRONT AND AT LEAST A FEW HOURS OF LIGHT WINDS AND MUCH
DRIER AIR COULD SEE FAIRLY CHILLY LOWS ACROSS MUCH OF THE CWA WITH
VALUES IN THE MID TO UPPER 50S. PRECIP CHANCES DO NOT LOOK
PARTICULARLY GREAT THROUGH THE PERIOD BOTH DUE TO MORE STABLE AIR
MOVING IN BEHIND THE FRONT AND THEN WITH STRONG RIDGE DEVELOPING
NEAR THE AREA. LEFT A FEW AREAS SMALL CHANCES...ESPECIALLY ON SAT
DUE TO FRONTAL TIMING CONCERNS AND AGAIN ON WEDNESDAY AS GEFS DATA
BRINGING FAIRLY HIGH PROBABILITIES OF MEASURABLE PRECIP OVERNIGHT
TUES INTO WED MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM MDT WED AUG 1 2012
SCATTERED THUNDERSTORMS ARE MOVING EAST...DECREASING IN
COVERAGE...AND BECOMING ISOLATED RAIN SHOWERS ACROSS THE CENTRAL
HIGH PLAINS REGION. THISE ISOLATED SHOWERS WILL BE DIMINISHING
BY ABOUT 08Z. VFR CONDITIONS WILL PREVAIL THROUGH THE TAF PERIOD
AT BOTH KMCK AND KGLD WITH ANOTHER ROUND OF ISOLATED SHOWERS
ACROSS THE REGION AFTER ABOUT 22Z THURSDAY AFTERNOON AND EVENING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...LOCKHART
SHORT TERM...FOLTZ
LONG TERM...JRM
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS WICHITA KS
1155 PM CDT WED AUG 1 2012
.AVIATION...06Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
PUSHED BACK TIMING OF VCTS FOR RSL AND SLN A COUPLE HOURS DUE TO
RECENT RADAR TRENDS. LATEST GUIDANCE FROM THE HRRR NOW HAS THE MCS
FIZZLING OUT AROUND 14Z...SO TOOK OUT MENTION OF VCTS AT CNU.
DIFFICULT FORECASTING THE OUTFLOW STRENGTH AND TIMING BUT AM
REASONABLY CONFIDENT THAT OUTFLOW SHOULD AFFECT HUT...ICT AND CNU
SOMETIME JUST AFTER SUNRISE. HOWEVER THIS WILL HAVE TO BE
MONITORED CLOSELY ALONG WITH THE SKY TRENDS WITH THE MCS. NAM
TRIES TO DEVELOP CONVECTION AGAIN THURSDAY AFTERNOON...BUT THINK
THIS IS BECAUSE IT HAS VERY WARM TEMPERATURES LIKELY REACHING
CONVECTIVE TEMPERATURE AND FORMING PRECIPITATION. GIVEN THE LAST
FEW AFTERNOONS NOT SEEING MUCH...HAVE DECIDED TO LEAVE MENTION OUT
FOR NOW.
&&
ARL
.PREV DISCUSSION... /ISSUED 928 PM CDT WED AUG 1 2012/
UPDATE...
TRIMMED BACK POPS FOR CENTRAL KANSAS A LITTLE BEFORE 06Z AS THE
ACTIVITY HAS BARELY ENTERED EXTREME NORTHWEST KANSAS AT THIS HOUR.
AREAL COVERAGE OF POPS THOUGH LOOKS GOOD FROM 9Z ON SO LEFT THAT
AS IS. GUSTY DOWNBURST WINDS ARE STILL POSSIBLE WITH STORMS THAT
DO MAKE IT INTO THE AREA AS DCAPE VALUES EXTEND AS HIGH AT 2000
J/KG.
ARL
PREV DISCUSSION... /ISSUED 643 PM CDT WED AUG 1 2012/
AVIATION...00Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
NOT MUCH CHANGE TO PREVIOUS FORECAST AS VFR CONDITIONS SHOULD
DOMINATE MOST OF THE PERIOD FOR ALL SITES DUE TO 500MB RIDGE
CENTERED OVER THE SOUTHERN HIGH PLAINS. MOISTURE FLOWING NORTHWARD
AROUND THE WESTERN PERIPHERY OF THIS RIDGE IS CAUSING DIURNAL
CONVECTION TO FORM OVER THE HIGH PLAINS AND BEGINNING TO SLOWLY
DRIFT EAST/SOUTHEAST. WITH ELEVATED INSTABILITY IN NORTH CENTRAL
KANSAS OVERNIGHT THE BEST SHOT AT SHOWERS STILL APPEARS TO BE AT
RSL AND SLN AROUND 6 TO 12Z. WASN`T CONFIDENT ENOUGH TO ENTER VCTS
AT HUT...ICT OR CNU...BUT WILL HAVE TO REEVALUATE FOR THE 12Z
CYCLE. OVERNIGHT MCS COULD PROPAGATE AROUND TO THE SOUTHEAST ALONG
A 850MB BAROCLINIC ZONE TOWARDS CNU BY 12Z...BUT DECIDED TO LEAVE
THE VCTS OUT FOR THE MOMENT. WIND FORECAST IS ALSO TRICKY DUE TO
POSSIBLE OUTFLOW FROM THE MCS AND THE SURFACE TROUGH THAT NOSES
INTO SOUTH CENTRAL KANSAS...BUT THE GENERAL THEME IS THAT WINDS
SHOULD MOSTLY BE OUT OF THE SOUTHEAST.
LAUGEMAN
PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/
DISCUSSION...
MESO HIGH FROM LAST NIGHTS/THIS MORNINGS CONVECTION HAS RESULTED
IN A MUCH COOLER DAY THAN PREVIOUSLY ANTICIPATED OVER PORTIONS OF
CENTRAL/EASTERN KS. ASSOCIATED OUTFLOW BOUNDARY EXTENDS EAST/WEST
ACROSS NORTHERN OK...SO ANY ISOLATED CONVECTIVE DEVELOPMENT THIS
AFTERNOON/EVENING WILL REMAIN SOUTH OF THE KS/OK BORDER. HOWEVER
SIMILAR TO LAST NIGHT...WEAK MONSOONAL ENERGY ROUNDING TOP OF
RIDGE COULD PROVIDE ANOTHER ROUND OF SHOWERS/THUNDERSTORMS OVER
PORTIONS OF CENTRAL/EAST-CENTRAL KS AFTER MIDNIGHT...ALONG
NORTHERN FRINGE OF STOUT 850-700MB THERMAL RIDGE. THINKING HIGHEST
PROBABILITIES WILL REMAIN NORTH OF WICHITA.
LIKE TODAY...ANY POTENTIAL CONVECTIVE OUTFLOW COULD THROW A WRENCH
INTO THURSDAY MAX TEMPERATURES...WITH A WIDE RANGE OF TEMPERATURES
LIKELY ACROSS THE BOUNDARY. DUE TO GOOD MIXING AND 30-34C 850MB
TEMPERATURES...HIGHS SOUTH OF THE BOUNDARY SHOULD SOAR ABOVE 110
DEGREES...HIGHEST PROBABILITIES OVER SOUTHERN/SOUTHEAST KS.
HOWEVER...DUE TO CONVECTIVE OUTFLOW UNCERTAINTIES...WILL PUNT HEAT
HEADLINES DECISION TO THE NIGHT SHIFT. DUE TO THE VERY HOT
TEMPERATURES AND BOUNDARY IN VICINITY...COULD SEE A FEW HIT-AND-MISS
LATE AFTERNOON/EVENING THUNDERSTORMS OVER SOUTHERN KS
THURSDAY...WITH ANOTHER ROUND OF SHOWERS/THUNDERSTORMS POSSIBLE
THURSDAY NIGHT-EARLY FRIDAY OVER MAINLY CENTRAL KS...AS MORE WEAK
MONSOONAL ENERGY TOPS RIDGE.
ANOTHER VERY HOT FRIDAY IS ANTICIPATED...WITH AFTERNOON HIGHS LIKELY
SOARING ABOVE 105 DEGREES FOR MANY AREAS. LIKE THURSDAY...CANNOT
RULE OUT A FEW HIT-AND-MISS AFTERNOON/EVENING THUNDERSTORMS DUE TO
WEAK BOUNDARY IN VICINITY.
SHORT-MEDIUM RANGE GUIDANCE CONTINUES TO SUGGEST A COLD FRONT WILL
PASS SOUTHEAST ACROSS THE REGION SATURDAY...ASSOCIATED WITH AN
AMPLIFIED SHORTWAVE TROUGH OVER THE UPPER MISSISSIPPI VALLEY. AFTER
ANOTHER HOT DAY OVER SOUTHERN/CENTRAL KS SATURDAY AHEAD OF THE
FRONT...READINGS BY SUNDAY SHOULD DROP INTO THE 90S FOR MOST
LOCATIONS BEHIND THE FRONT...WHICH WILL BE NEAR SEASONAL NORMALS.
ADDITIONALLY...AT LEAST ISOLATED TO WIDELY SCATTERED THUNDERSTORMS
WILL BE POSSIBLE ALONG THE FRONT LATE FRIDAY NIGHT...AND ESPECIALLY
SATURDAY AFTERNOON/EVENING. HOWEVER...OTHER THAN ISOLATED
RELIEF...WIDESPREAD APPRECIABLE RAINS APPEAR UNLIKELY.
FOR MONDAY AND BEYOND...UNCERTAINTY EXISTS IN THE MODELS WHETHER THE
ABNORMALLY WARM SUMMER TEMPERATURES WILL RETURN. ECMWF SUGGESTS
RIDGE WILL BUILD BACK IN...RESULTING IN HOT AND DRY WEATHER
RETURNING. HOWEVER...GFS AND ASSOCIATED ENSEMBLES KEEP THE RIDGE
CENTERED WEST OF THE REGION...WHICH WOULD RESULT IN READINGS CLOSER
TO SEASONAL NORMALS...ALONG WITH PERIODIC CHANCES FOR PRECIPITATION.
WILL HOPE THAT THE GFS AND ASSOCIATED ENSEMBLES VERIFY.
KLEINSASSER
AVIATION...18Z TAFS KRSL/KSLN/KHUT/KICT/KCNU
VFR CONDITIONS EXPECTED TO PREVAIL THRU THE FORECAST VALID PERIOD.
AN IMPRESSIVE CONVECTIVE OUTFLOW BOUNDARY AND THE EAST TO
NORTHEAST WIND FLOW BEHIND IT WILL GRADUALLY WEAKEN THROUGH THE
AFTERNOON ACROSS THE AREA. HOWEVER ANOTHER COMPLEX OF STORMS IS
LIKELY TO DEVELOP ACROSS THE HIGH PLAINS THIS EVENING...WHICH
COULD IMPACT CENTRAL KANSAS AGAIN EARLY THURSDAY MORNING. FOR
NOW CONFIDENCE WAS ONLY HIGH ENOUGH TO INSERT VCTS AT KRSL AND
KSLN.
KED
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 106 77 106 77 / 10 10 10 20
HUTCHINSON 104 77 104 77 / 10 20 10 20
NEWTON 103 76 103 76 / 10 20 20 20
ELDORADO 103 77 104 77 / 10 20 20 20
WINFIELD-KWLD 108 78 109 78 / 10 10 10 20
RUSSELL 100 75 101 75 / 10 40 20 20
GREAT BEND 102 76 102 76 / 10 30 10 20
SALINA 100 75 101 75 / 10 40 20 20
MCPHERSON 102 76 102 76 / 10 30 20 20
COFFEYVILLE 108 78 108 78 / 10 10 20 20
CHANUTE 103 76 102 76 / 10 30 30 20
IOLA 102 75 101 75 / 10 30 30 20
PARSONS-KPPF 105 78 105 78 / 10 20 20 20
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
204 PM EDT THU AUG 2 2012
.UPDATE...
ISSUED AT 204 PM EDT THU AUG 2 2012
PREVIOUS FORECAST WAS LARGELY ON TRACK...AND ONLY MINOR ADJUSTMENTS
WERE MADE.
UPDATE ISSUED AT 1057 AM EDT THU AUG 2 2012
HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL.
WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A
BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM
IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT
ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT
IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR
THIS.
UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012
A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME
AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST
OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND
MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE
ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE
ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS.
LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE
SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON.
HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM
ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE
UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE
MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB
SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY
SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP
THE ZONES TO REMOVE THE PRE FIRST PERIOD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 340 AM EDT THU AUG 2 2012
SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO
VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER
OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE
GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY...
INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR
SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE
CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE
HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE
YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH
TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD
RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN
CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE.
OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY
PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST
HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE
CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON.
CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER
LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY
SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION
TODAY.
GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE
ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH
THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A
DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE
ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY
POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO
BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED
WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH
INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY.
TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE
CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID
90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH.
THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP
GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER
CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR
SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE
GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM
WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE
MOMENT AND MENTION BOTH IN THE HWO.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 AM EDT THU AUG 2 2012
THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN
HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN
US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY
SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD
FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY
FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY
AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS
FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS
THE SETTING SUN WILL STABILIZE THE AIR MASS AND FINALLY GIVE THE AREA
A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN
AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS
PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT
TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE
WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON
SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN
REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND
LOWER 90S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 204 PM EDT THU AUG 2 2012
MOST VFR CONDITIONS ARE FORECAST THROUGH THE PERIOD. THERE WILL BE A
COUPLE OF EXCEPTIONS...THOUGH. VALLEY FOG WILL BRING LOCALIZED IFR
LATE TONIGHT INTO EARLY FRIDAY MORNING. THUNDERSTORMS MAY DEVELOP
FROM SW TO NE OVER THE AREA OVERNIGHT AND ON FRIDAY. AT THIS
POINT...THE PROBABILITY LOOKS TOO LOW TO WARRANT ANYTHING MORE THAN
VCTS AT TAF SITES.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...MB
LONG TERM....DUSTY
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1057 AM EDT THU AUG 2 2012
.UPDATE...
ISSUED AT 1057 AM EDT THU AUG 2 2012
HAVE LOWERED CLOUD COVER FOR TODAY TO GIVE A SUNNY FORECAST OVERALL.
WHAT CUMULUS THAT DO POP UP SHOULD BE LIMITED AND MAINLY IN THE FAR
SOUTHERN AND EASTERN PORTIONS OF THE FORECAST AREA. HAVE ALSO ADDED A
BIT OF THE TYPICAL LATE SUMMER VALLEY FOG FOR LATE TONIGHT. THE NAM
IS ALSO ADVECTING ELEVATED INSTABILITY INTO OUR SW COUNTIES OVERNIGHT
ON ISENTROPIC LIFT. ALTHOUGH IT IS NOT AS PRONOUNCED IN THE GFS...IT
IS PERSISTENT NOW IN THE NAM...AND HAVE ADDED A SLIGHT CHANCE POP FOR
THIS.
UPDATE ISSUED AT 700 AM EDT THU AUG 2 2012
A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME
AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST
OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND
MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE
ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE
ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS.
LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE
SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON.
HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM
ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE
UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE
MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB
SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY
SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP
THE ZONES TO REMOVE THE PRE FIRST PERIOD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 340 AM EDT THU AUG 2 2012
SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO
VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER
OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE
GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY...
INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR
SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE
CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE
HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE
YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH
TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD
RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN
CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE.
OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY
PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST
HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE
CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON.
CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER
LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY
SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION
TODAY.
GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE
ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH
THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A
DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE
ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY
POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO
BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED
WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH
INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY.
TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE
CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID
90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH.
THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP
GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER
CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR
SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE
GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM
WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE
MOMENT AND MENTION BOTH IN THE HWO.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 AM EDT THU AUG 2 2012
THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN
HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN
US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY
SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD
FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY
FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY
AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS
FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS
THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA
A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN
AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS
PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT
TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE
WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON
SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN
REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND
LOWER 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 700 AM EDT THU AUG 2 2012
MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH
SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG
BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE
WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE
TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES
THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT
AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE
THE RULE THROUGH THE REMAINDER OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...MB
LONG TERM....DUSTY
AVIATION...MB
AREA FORECAST DISCUSSION
NWS JACKSON KY
700 AM EDT THU AUG 2 2012
.UPDATE...
ISSUED AT 700 AM EDT THU AUG 2 2012
A FEW CALLS TO LOCAL KSP POSTS REVEALED THAT THERE ARE INDEED SOME
AREAS OF DENSE FOG THROUGHOUT THE VALLEYS THIS MORNING...MAINLY EAST
OF A LINE FROM ABOUT WEST LIBERTY...THROUGH JACKSON...TO AROUND
MIDDLESBORO...THOUGH SOME OF THE STATIONS AROUND THE CUMBERLAND ARE
ALSO BEGINNING TO REPORT DETERIORATING VISIBILITIES...AND HAVE
ISSUED A SPS THROUGH 9 A.M. TO ACCOUNT FOR THIS.
LATEST HRRR ALONG WITH ITS FEW PREVIOUS RUNS CONTINUES TO ADVERTISE
SOME ISOLATED...ANEMIC...CONVECTION OVER ERN KY THIS AFTERNOON.
HOWEVER...ASIDE FROM THE 02.00Z EURO...THERE IS NOT MUCH SUPPORT FROM
ANY OF THE REST OF THE MODELS. FEELING IS THAT MODELS HAVE
UNDERREPRESENTED A BIT THE LAST COUPLE OF DAYS...AND TODAY MAY BE
MORE OF THE SAME IF THE CAP CAN BE BROKEN...BUT WILL SIT ON THE SUB
SLIGHT POPS CURRENTLY ADVERTISED AND PASS ALONG CONCERNS TO THE DAY
SHIFT. OTW...NO MAJOR CHANGES IN THINKING ATTM BUT WILL FRESHEN UP
THE ZONES TO REMOVE THE PRE FIRST PERIOD.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 340 AM EDT THU AUG 2 2012
SFC ANALYSIS EARLY THIS MORNING SHOWS HIGH PRESSURE OVER THE OHIO
VALLEY WITH A RATHER ILL DEFINED BOUNDARY ROUGHLY ALONG THE UPPER
OHIO VALLEY THROUGH NRN KY AND ACROSS THE MID MS VALLEY. DEW PTS ARE
GENERALLY RUNNING IN THE MID TO UPPER 60S SOUTH OF THIS BOUNDARY...
INCLUDING ERN KY...WITH SLIGHTLY DRIER AIR TO THE NORTH. CURRENT IR
SHOT SHOWS FOG HAS ALREADY DEVELOPED ALONG THE UPPER REGIONS OF THE
CUMBERLAND...KENTUCKY...LICKING...AND SANDY BASINS...WHERE THE
HEAVIER RAINS FELL YESTERDAY...HOWEVER LOCAL OBS AND WEB CAMS HAVE
YET TO INDICATE THAT THE DENSEST FOG HAS BECOME WIDESPREAD ENOUGH
TO WARRANT ANY HEADLINES JUST YET. WITH A FEW MORE HOURS OF GOOD
RADIATIONAL COOLING LEFT...WILL CONTINUE TO KEEP AN EYE ON THIS IN
CASE IT BEGINS TO LOOK LIKE IT WILL AFFECT THE MORNING COMMUTE.
OTHERWISE...HIGH PRESSURE LOOKS TO BE IN THE DRIVERS SEAT TODAY
PROVIDING FOR GENERALLY CLEAR SKIES THROUGH MUCH OF THE DAY WITH FCST
HIGHS TARGETING THE LOWER 90S...AND A FEW LOCALS AROUND THE
CUMBERLAND VALLEY POSSIBLY SNEAKING INTO THE MID 90S THIS AFTERNOON.
CANNOT RULE OUT SOME INCREASING CU THIS AFTERNOON WITH THE LOWER
LEVELS BECOMING RATHER UNSTABLE BUT FCST SOUNDINGS INDICATE A FAIRLY
SOLID CAP AROUND H8 AND THIS SHOULD KEEP A LID ON ANY CONVECTION
TODAY.
GUIDANCE REMAINS IN GOOD AGREEMENT WITH BRINGING A ROBUST SHORT WAVE
ACROSS THE MID MS VALLEY INTO THE TN VALLEY LATE TONIGHT AND THROUGH
THE DAY ON FRIDAY. MODELS ARE STILL GRAPPLING WITH THE IDEA OF A
DECAYING MCS MOVING INTO WRN TN TOWARDS DAWN ON FRIDAY. WITH A STABLE
ATMOSPHERE EXPECTED TO BE IN PLACE OVER ERN KY...DO NOT FORESEE ANY
POTENTIAL FOR PRECIP OVERNIGHT. HOWEVER...MOISTURE IS PROGGED TO
BEGIN INCREASING EARLY ON FRIDAY AND WITH THAT IDEA IN MIND COUPLED
WITH THE POTENTIAL FOR OUTFLOWS FROM ACTIVITY TO THE SW PUSHING NORTH
INTO THE AREA...HAVE RAISED POPS ACROSS THE BOARD FOR US ON FRIDAY.
TEMPS OF COURSE WILL BE LARGELY DEPENDENT ON WHO GETS RAIN...BUT THE
CURRENT POPS SCHEME WOULD ALLOW THE BLUEGRASS TO REACH INTO THE MID
90S WITH HIGHS A LITTLE CLOSER TO 90 IN THE SOUTH.
THERE IS A GOOD POSSIBILITY THAT THERE WILL BE A RATHER SHARP
GRADIENT BETWEEN WHO SEES RAIN AND WHO DOES NOT...BUT ATTM THE BETTER
CHANCES STILL LOOK TO BE CLOSER TO THE KY/TN LINE. NAM AND GFS BUFR
SOUNDINGS ARE OFFERING DIFFERENT SCENARIOS THIS MORNING...WITH THE
GFS LEANING MORE TOWARDS A LOCALLY HEAVY RAIN THREAT WHILE THE NAM
WOULD SUGGEST A POTENTIAL FOR DAMAGING WINDS. WILL HEDGE FOR THE
MOMENT AND MENTION BOTH IN THE HWO.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 AM EDT THU AUG 2 2012
THE WEEKEND STARTS WITH A NEARLY ZONAL PATTERN AT 50H FOR THE ERN
HALF OF THE CONUS. AN AREA OF LOW PRESSURE IS TRACKING ACROSS THE NRN
US PLAINS BORDER WITH CANADA AND THEN ACROSS THE NRN GREAT LAKES. BY
SUNDAY THE 50H LOW AND THE SFC ASPECT OF THIS SYSTEM WILL DRAG A COLD
FRONT ACROSS THE COMMONWEALTH. EXPECT LIKELY SHRA/TSRA FOR ERN KY
FROM LATE FRI NIGHT THRU MUCH OF THE WEEKEND. EVEN INTO MONDAY
AFTERNOON...THE HEATING AND HIGH DEWPOINTS WILL PRODUCE CHANCE POPS
FOR THE REGION. RELIEF FROM THE RAIN WILL ARRIVE ON MONDAY NIGHT AS
THE SETTING SUN WILL STABALIZE THE AIR MASS AND FINALLY GIVE THE AREA
A TWO DAY BREAK FROM THE RAIN. THEN THE NORTHWEST FLOW WILL BEGIN
AGAIN AS A TROF BECOMES ESTABLISHED OVER THE ATLANTIC COAST. THIS
PATTERN NEARLY ALWAYS BRING RAIN BUT THE DISTURBANCES ARE DIFFICULT
TO TIME SO WOULD RATHER BROAD BRUSH THE POPS BEGINNING LATE
WEDNESDAY. TEMPERATURES WILL FALL SLIGHTLY WITH THE PASSING FRONT ON
SUNDAY AND DROP DAY TIME HIGHS INTO THE MID 80S BEFORE THEY CAN
REBOUND BY WED WITH HIGH READING CLIMBING BACK INTO THE UPPER 80S AND
LOWER 90S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 700 AM EDT THU AUG 2 2012
MVFR FOG IS AFFECTING SOME OF THE TERMINALS EARLY THIS MORNING WITH
SITES SUCH AS KLOZ...KEKQ...AND K1A6 LIKELY TO SEE IFR BEFORE THE FOG
BEGINS TO LIFT AND MIX OUT BY 13Z. CLR SKIES THIS MORNING MAY GIVE
WAY TO SCT CU THIS AFTERNOON BEFORE CIGS BEGIN TO INCREASE LATE
TONIGHT AS A DISTURBANCE CURRENTLY OVER THE CENTRAL PLAINS APPROACHES
THE TN VALLEY. HOWEVER...CIGS ARE EXPECTED TO REMAIN AOA 5KFT
AND...ONCE THE FOG LIFTS THIS MORNING...VFR AND LIGHT WINDS SHOULD BE
THE RULE THROUGH THE REMAINDER OF THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...MB
SHORT TERM...MB
LONG TERM....DUSTY
AVIATION...MB
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1025 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE
COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
10PM UPDATE...NO CHANGES. PATCHY FOG STILL EXPECTED THROUGH MUCH
OF THE NIGHT.
PREV DISCUSSION...
CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND
HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE.
TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE
APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS
PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS
AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS
INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND
GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO
AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH
WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND
DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW
BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER
AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT
MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND
DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT
INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE
IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY
FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME
WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS
WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL.
HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL
PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX
TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S
W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE
MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE
COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT
INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT
HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO
THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS
WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS
WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF
AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY
LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY.
AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH
POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD
OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY
LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT
AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE
SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY
MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE
OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO
EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE
FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL
BE LAST TO CLEAR DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT.
DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY
NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY
THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES
ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE
NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /03Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING
W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY
MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED
TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE
VFR.
SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART.
HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN
EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING
COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER
COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5
FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME
OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS
HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE
OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED
THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT
AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3
FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW.
SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES
GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING
DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY
DROPPING THEM BACK 1-2 FEET.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT/RUNYAN
SHORT TERM...FITZSIMMONS
LONG TERM...OKULSKI
AVIATION...HEWITT/RUNYAN
MARINE...HEWITT/RUNYAN/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
157 PM EDT THU AUG 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER
COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL
RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR.
WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER
COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: ADDED HEAVY RAIN WORDING THE WX ELEMENT AS STORM MOTION
LESS THAN 10 KTS AND LATEST LAPS SOUNDINGS INDICATE K INDEX OF 35+
WEHRE STORMS ARE FIRING. STORMS ARE SLOW MOVING AND COULD DUMP UP
TO 1"RAFL/HR.
PREVIOUS DISCUSSION...
WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE
FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP
THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE
HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK.
THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE
BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED
POPS DOWN A BIT DUE TO THIS THINKING.
PREVIOUS DISCUSSION...
VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A
MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF
THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE
ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY
PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER
ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM
IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE...
THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/
A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE
AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY -
THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E
OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM
TO NOT BE A FACTOR...
WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS
TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS
RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W
YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR
A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN
HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS
TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS
AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE
COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE
CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF
THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS
REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN
THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST.
DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A
PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE
ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES
BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER
DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE,
DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER
CONDITIONS; HIGHS WILL BE IN THE MID 80S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS
LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM
WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY,
DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO.
AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE
LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS
FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING
COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY.
PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT
MOVES INTO NORTHERN MAINE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES
VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM
NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY
THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/
CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR
AT OUR SRN TAF SITES W/ LESSER CHCS N.
SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR
CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND
THUNDERSTORMS FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT...
SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN
CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES
ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY
EVE THRU MID AM HRS...
SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD
OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE.
RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO
MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE
NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY
BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE
WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
941 AM EDT THU AUG 2 2012
.SYNOPSIS...
A WEAKENING COLD FRONT WILL CROSS THE REGION THIS AFTERNOON. ANOTHER
COLD FRONT WILL CROSS THE AREA ON FRIDAY. HIGH PRESSURE WILL
RETURN FOR SATURDAY WITH PLEASANTLY WARM BUT LESS HUMID AIR.
WARMER AND MORE HUMID CONDITIONS RETURN ON SUNDAY AHEAD OF ANOTHER
COLD FRONT EXPECTED TO CROSS THE AREA ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE: NEEDED TO BOOST DEWPOINTS UP THROUGHOUT THE CWA BRINGING
THEM INTO THE MID AND UPPER 60S BY THE AFTERNOON. LATEST SATL
VISIBLE IMAGERY SHOWED STRATUS AND FOG BEGINNING TO ERODE THANKS
TO DAYTIME HEATING. CLEARING ACROSS THE WEST AND NORTHWEST HAS LED
TO TEMPERATURES RISING INTO THE LOWER 70S. THEREFORE, AFTERNOON
HIGHS WERE RAISED AS WELL AS THIS CLEARING WILL WORK EAST ALLOWING
FOR MORE SUNSHINE. DECIDED TO BRING MAXES UP TO AOA 80F ACROSS THE
NORTHERN AND CENTRAL AREAS WHILE DOWNEAST AND THE COAST WILL BE
COOLER THANKS IN PART TO THE ONSHORE FLOW(SSE WIND).
WIDELY SCATTERED TSTMS EXPECTED THIS AFTERNOON RIGHT ALONG THE
FRONT. LATEST HRRR SHOWED A LINE OF BROKEN CONVECTION SETTING UP
THIS AFTERNOON BUT NOT SEVERE. IT LOOK LIKE ANY TSTMS WILL HAVE
HEAVY RAIN AS WBZS ARE ABOVE 11K FT AND FORCING IN RATHER WEAK.
THERE IS SOME LLVL CONVERGENCE SETTING UP AHEAD AND ALONG THE
BOUNDARY AS IT MOVES THROUGH THIS AFTERNOON. THEREFORE, ADJUSTED
POPS DOWN A BIT DUE TO THIS THINKING.
PREVIOUS DISCUSSION...
VERY WEAK FRONTAL BNDRY CURRENTLY JUST W AND NW OF THE AREA W/ A
MILD AND RATHER HUMID LGT SRLY IN PLACE ACROSS OUR REGION AHEAD OF
THIS SYSTEM... A FEW VRY LGT SHOWERS APPEAR TO BE LIFTING NE
ACROSS THE FA PER RADAR THO NO RPTG STATIONS HAVE CARRIED ANY
PRECIP LAST FEW HRS. EVEN AN ISOLD TSTM NOTED JUST W OF OUR BORDER
ATTM - TO THE NW OF DAAQUAM. OTHER FEATURE OF INTEREST ERLY THIS AM
IS ANOTHER LOW PRES SYSTEM WELL SW OF THEN AREA - JUST S OF THE CAPE...
THE WEAK FRONTAL BNDRY WILL CONT TO SLOWLY CROSS THE AREA TDY W/
A BIT STRONGER FRONT ADVERTISED FOR FRI. LOW PRES WELL SW OF THE
AREA SIMILAR TO THE SYSTEM THAT AFFECTED THE REGION YESTERDAY -
THO WEAKER W/ THIS ONE EXPECTED TO TRACK A LITTLE FURTHER S AND E
OF THE AREA. AS A RESULT...EXPECT PRECIP ASSOCIATED W/ THIS SYSTEM
TO NOT BE A FACTOR...
WILL CONT W/ PREVIOUS FCST THINKING AND WILL CARRY JUST CHC POPS
TDY ACROSS THE FA AS UPPER SUPPORT W/ THIS SYSTEM APPEARS
RELATIVELY WEAK. SYSTEM SUPPORTED SOME CONVECTION TO OUR W
YESTERDAY AND W/ TDS IN THE 60S TDY...SFC HEATING SHOULD ALLOW FOR
A THREAT OF THUNDER OUR AREA TDY AS WELL SPCLY DURING THE AFTN
HRS. TEMPS EXPECTED TO WARM A FEW DEGREES OVER YESTERDAY W/ LOWS
TNGT AGAIN SIMILAR TO THE LAST FEW NGTS. LATE NGT/ERLY AM LOW CIGS
AND FOG A CONTG THREAT...SPCLY ACROSS THE SRN AREAS NEAR THE
COAST.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
A COLD FRONT WILL MOVE ACROSS THE REGION ON FRIDAY, BRINGING THE
CHANCES FOR SHOWERS AND THUNDERSTORMS TO MUCH OF THE STATE. AHEAD OF
THE FRONT, SOUTH FLOW WILL KEEP MUGGY CONDITIONS AROUND AS DEWPOINTS
REACH INTO THE LOWER AND MID 60S. HIGHS WILL RANGE FROM AROUND 80 IN
THE SAINT JOHN VALLEY TO THE UPPER 80S ACROSS THE INTERIOR DOWNEAST.
DRIER AIR WILL WORK INTO THE REGION BEHIND THE FRONT, LEADING TO A
PLEASANT NIGHT FRIDAY NIGHT. HOWEVER, HUMIDITY WILL BEGIN TO MAKE
ITS RETURN TO MAINE LATE SATURDAY AS THE COLD FRONT SLOWLY MOVES
BACK NORTH AS A WARM FRONT. NORTHERN AREAS WILL SEE A NICE SUMMER
DAY ON SATURDAY WITH HIGHS AROUND 80 AND LOW HUMIDITY. MEANWHILE,
DOWNEAST MAINE WILL SEE A RETURN TO MUCH WARMER AND MUGGIER
CONDITIONS; HIGHS WILL BE IN THE MID 80S.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE WARM FRONT LIFTS ACROSS THE REGION SATURDAY NIGHT INTO SUNDAY AS
LOW PRESSURE MOVES EASTWARD THROUGH THE GREAT LAKES. THIS SYSTEM
WILL MOVE NORTH OF THE FORECAST AREA SUNDAY NIGHT INTO MONDAY,
DRAGGING ITS ATTENDANT COLD FRONT ACROSS NEW ENGLAND AS IT DOES SO.
AS SUCH, THE CHANCES FOR SHOWERS AND THUNDERSTORMS WILL INCREASE
LATE SUNDAY, BUT ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY. THIS
FRONT WILL BE FOLLOWED BY A BRIEF RIDGE OF HIGH PRESSURE, BRINGING
COOLER TEMPERATURES AND DRY WEATHER FOR MONDAY NIGHT AND TUESDAY.
PRECIP CHANCES THEN INCREASE AGAIN BY MID WEEK AS ANOTHER FRONT
MOVES INTO NORTHERN MAINE.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
NEAR TERM: CURRENTLY KBHB AND KBGR IFR W/ OUR REMAINING TAF SITES
VFR... EXPECT SOME LOWER CIGS TO ARRIVE KHUL NEXT HR OR SO BUT AM
NOT CONFIDENT THAT THESE CONDS WILL REACH OUR NRN TAF SITES ERLY
THIS AM. FOR NOW WILL JUST ADVERTISE SOME MVFR UP N IN BR W/
CONFIDENCE LOW ATTM. MORE OF THE SAME TNGT W/ BEST THREAT OF IFR
AT OUR SRN TAF SITES W/ LESSER CHCS N.
SHORT TERM: VFR GENERALLY EXPECTED INTO EARLY NEXT WEEK, BUT MVFR
CONDITIONS WILL BE POSSIBLE IN MAINLY AFTERNOON SHOWERS AND
THUNDERSTORMS FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: LGT SE SWELL CURRENTLY RESULTING IN SEAS AROUND 4 FT...
SEAS GENERALLY EXPECTED TO REMAIN IN THE 3-5 FT RANGE THRU TNGT IN
CONTG LGT SE SWELL W/ MAINLY LGT (<15 KT SRLY WNDS). NO HEADLINES
ANTICIPATED THRU TNGT W/ AREAS OF FOG CONTG MAINLY DURING THE ERLY
EVE THRU MID AM HRS...
SHORT TERM: A COLD FRONT WILL MOVE ACROSS THE WATERS LATE FRIDAY. AHEAD
OF THIS FRONT, WAVES WILL APPROACH 5 FT AS SOUTH WINDS INCREASE.
RIGHT NOW THINGS LOOK MARGINAL, BUT LATER SHIFTS WILL HAVE TO
MONITOR TRENDS AS A SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS MAY BE
NECESSARY FRIDAY. WAVES WILL SUBSIDE FRIDAY NIGHT AND SATURDAY
BEHIND THE FRONT; NO HEADLINES SHOULD BE NECESSARY THROUGH THE
WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT/KHW
SHORT TERM...HASTINGS
LONG TERM...HASTINGS
AVIATION...HEWITT/KHW
MARINE...HEWITT/KHW/HASTINGS
AREA FORECAST DISCUSSION
NWS GRAY ME
1211 AM EDT THU AUG 2 2012
.SYNOPSIS...
LOW PRESSURE WILL TRACK EAST THROUGH THE SAINT LAWRENCE VALLEY
TONIGHT... WITH A WEAK FRONT EXTENDING SOUTHWARD THROUGH NORTHERN
NEW ENGLAND. ANOTHER LOW WILL TRACK THROUGH QUEBEC ON THURSDAY
WITH A COLD FRONT PUSHING INTO THE AREA THURSDAY NIGHT AND FRIDAY.
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR SATURDAY AND
SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...
MINOR ADJUSTMENTS TO POPS AND QPF OVER THE NEXT FEW HRS. ONE CELL
OVER N-CNTRL GRAFTON CO CONTS TO MOV E. THIS WILL SLOWLY DISSIPATE
WITH TIME.
OTRW...PATCHY FOG WILL CONT TO FORM OVERNIGHT AS DEW POINT VALUES
REMAIN HIGH. REST OF FCST WILL REMAIN UNCHANGED AT THIS TIME.
LATEST HRRR MODEL RUN HAS CONVECTION FIRING OVER THE NRN MTNS
TODAY. TIMING APPEARS TO BE AROUND 1 PM AND THEREAFTER.
PREVIOUS DISCUSSION...
MAINE AND NEW HAMPSHIRE ARE CAUGHT BETWEEN TWO LOW PRESSURE
SYSTEMS. THE FIRST MOVED THROUGH THE GULF OF MAINE AND INTO NOVA
SCOTIA THIS MORNING... WHILE THE OTHER SPUN THROUGH THE SAINT
LAWRENCE VALLEY. A WEAK TROUGH / COLD FRONT EXTENDS SOUTHWARD FROM
THIS LOW ACROSS NEW HAMPSHIRE THIS AFTERNOON. THE COMBINATION OF
LIFT FROM THE SHORTWAVE TROUGH ALOFT... WEAK CONVERGENCE AT THE
SURFACE... AND MOIST AIR IN PLACE GENERATING WEAK INSTABILITY THIS
AFTERNOON WILL LEAD TO A CHANCE OF SHOWERS AND A FEW THUNDERSTORMS
THROUGH EARLY EVENING. THESE SHOULD DISSIPATE IN LARGE PART AFTER
SUNSET... BUT FURTHER NORTH CLOSER TO THE SURFACE LOW AND COLD
CORE ALOFT... SHOWERS MAY CONTINUE INTO THE NIGHT.
WITH A LOT OF MOISTURE AROUND... DEW POINTS IN THE MID 60S... FOG
IS POSSIBLE TONIGHT. HOWEVER... EXPECT A LOT OF CLOUD COVER
OVERNIGHT AFTER CONVECTION DEVELOPS AND IN ASSOCIATION WITH LIFT
FROM THE SHORTWAVE TROUGH. THIS MAY LIMIT THE FOG POTENTIAL
SOMEWHAT OVERNIGHT. TEMPERATURES STAY IN THE 60S OVERNIGHT DUE TO
ALL THE MOISTURE IN PLACE.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM FRIDAY/...
INITIAL SHORTWAVE TROUGH AXIS STILL LINGERS ACROSS THE AREA
THROUGH THURSDAY. LIFT AHEAD OF THIS FEATURE WILL EXIST ESPECIALLY
ACROSS MUCH OF MAINE AND COASTAL AREAS. THIS... IN COMBINATION
WITH LOW LEVEL MOISTURE AND INSTABILITY... MAY LEAD TO SHOWERS AND
THUNDERSTORMS DEVELOPING ALONG THE COASTAL PLAIN BY LATE MORNING.
SURFACE BASED CAPE INDICATED BY THE NAM MODEL EXCEEDS 1200 AND
WOULD BE ENOUGH FOR THUNDERSTORMS. SUBSIDENCE BEHIND THE SHORTWAVE
TROUGH AXIS OVER NEW HAMPSHIRE SHOULD LIMIT SHOWER AND
THUNDERSTORM COVERAGE HERE. FOR NOW HAVE INDICATED A CHANCE OF
SHOWERS AND THUNDERSTORMS IN THIS AREA... WITH HIGHS IN THE 80S.
ANOTHER SHORTWAVE TROUGH CROSSES THROUGH SOUTHERN CANADA... WITH A
COLD FRONT PUSHING SOUTH TOWARD THE INTERNATIONAL BORDER THURSDAY
NIGHT. COULD BE MORE SHOWER ACTIVITY PUSHING SOUTHWARD WITH THIS
BY EARLY FRIDAY MORNING. MAY BE A BETTER POTENTIAL FOR FOG
THURSDAY NIGHT AS MOISTURE LEVELS REMAIN HIGH AND SKY WILL BE MORE
CLEAR AS DAYTIME SHOWERS DISSIPATE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A WEAK COLD FRONT WILL SLOWLY PUSH ACROSS THE AREA ON FRIDAY...BUT
FORCING IS QUITE WEAK...SO ONLY EXPECTING A FEW ISOLATED SHOWERS
AND THUNDERSTORMS AS IT MEANDERS TO THE SOUTHEAST. A WEAK HIGH
PRESSURE WILL BUILD IN BEHIND THE FOR THE WEEKEND...BUT A MUCH
STRONGER COLD FRONT WILL MOVE IN FROM THE GREAT LAKES LATE SUNDAY.
THERE IS SOME TIMING DIFFERENCES BETWEEN THE EURO AND GFS...WITH
THE GFS DRAGGING THE FRONT ACROSS SUNDAY NIGHT INTO MONDAY
MORNING...WHILE THE EURO BRINGS IT THROUGH EARLY MONDAY AFTERNOON.
THE EUROS PASSAGE WILL MIRROR PEAK HEATING ON MONDAY. THIS
SCENARIO...WITH A DECENT THERMODYNAMIC ENVIRONMENT...WILL GIVE US A
GOOD CHANCE FOR THUNDERSTORM DEVELOPMENT BY MIDDAY MONDAY. WITH
THE CURRENT UNCERTAINTY...STILL JUST LEAVING THINGS AS A CHANCE OF
THUNDERSTORMS. AFTER THE FRONT PASSES...HIGH PRESSURE WILL BUILD
IN AND KEEP THINGS QUIET THROUGH WEDNESDAY.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
SHORT TERM...EXPECTING MOSTLY VFR CONDITIONS AND LIGHT SOUTH TO
SOUTHWESTERLY WINDS... BUT MVFR IN SHOWERS THIS EVENING IS POSSIBLE.
BEST CHANCE OF THUNDER WILL BE OVER NEW HAMPSHIRE... AND IN
PARTICULAR NORTHERN NEW HAMPSHIRE CLOSER TO THE SHORTWAVE TROUGH
ALOFT. THERE IS THE POTENTIAL FOR NOCTURNAL FOG OVERNIGHT AS LOW
LEVEL MOISTURE IS HIGH. HOWEVER... CLOUD COVER MAY BE TOO
EXTENSIVE FOR FOG FORMATION AND CONFIDENCE IN FOG CAUSING REDUCED
VISIBILITIES TONIGHT IS DECREASING. ON THURSDAY THERE WILL BE A
CHANCE OF SHOWERS AND THUNDERSTORMS ACROSS THE COASTAL PLAIN...
WITH A BETTER CHANCE OF FOG THURSDAY NIGHT.
LONG TERM...
FRONTAL BOUNDARY COMING THROUGH ON MONDAY COULD DROP CIGS/VIS TO
IFR/MVFR.
&&
.MARINE...
SHORT TERM...LIGHT SOUTH TO SOUTHWEST FLOW EXPECTED OVER THE
WATERS TONIGHT AND TOMORROW. SEAS WILL SLOWLY SUBSIDE.
LONG TERM...
SCA CRITERIA MAY BE MET LATE SUNDAY INTO MONDAY AS A FRONTAL
BOUNDARY APPROACHES THE AREA.
&&
.EQUIPMENT...
DUAL POLARIZATION UPGRADE OF THE GYX RADAR HAS BEEN COMPLETED.
RADAR DATA IS NOW FLOWING THROUGH NORMAL CHANNELS.
COMMUNICATIONS WITH KRKD SEEM TO HAVE BEEN RESTORED AGAIN. ISSUE
MAY NOT BE PERMANENTLY RESOLVED. AS OBSERVATIONS CONTINUE TO COME
IN THROUGH NORMAL CHANNELS THE TAF WILL BE PRODUCED AS NORMAL.
HOWEVER... IF OBSERVATIONS DROP OUT AGAIN THEN THE "AMD NOT SKED"
REMARK MAY HAVE TO BE ADDED AGAIN.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...NONE.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
923 PM EDT FRI AUG 3 2012
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OFFSHORE THROUGH THE WEEKEND. A COLD
FRONT WILL CROSS THE GREAT LAKES SUNDAY...BEFORE MOVING THROUGH
SUNDAY NIGHT. WEAK HIGH PRESSURE WILL MOVE OVER THE MID-ATLANTIC
REGION FOR THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SIMILAR TO LAST EVENING...MOST OF THE SHOWERS AND THUNDERSTORMS
HAVE DISSIPATED WITH THE SETTING OF THE SUN BUT A COUPLE OF
ISOLATED CELLS REMAIN AT 01Z. THESE WILL LIKELY ALSO DISSIPATE
WITHIN THE NEXT COUPLE OF HOURS ALTHOUGH THE HRRR SUGGESTS THAT AN
ISOLATED SHOWER STILL CAN/T BE RULED OUT TOWARD THE HIGHLANDS/SHENANDOAH
VALLEY AREA OVERNIGHT. MID-CLOUDS MAY THIN OUT/SCATTER OVERNIGHT...SO
PATCHY FOG MAY ALSO FORM LATER TONIGHT.
TMRW WL BE A TYPICAL ERLY AUG DAY..IN FACT QUITE A BIT LK TDA.
LGT FOG WL BECOME HZ...HZ WL BECOME AFTN CU. ONCE AGN THE MTNS WL
BE THE BEST PLACE FOR AFTN CNVCTN TO FORM. HIGH TEMPS AGN XPCTD TO
RANGE FM THE U80S TO THE M90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
DIURNAL CONVECTION ON SAT WILL WANE DURING THE EVE WITH THE LOSS
OF DAYTIME HEATING. SAT NGT WILL BE MUGGY...WITH MIN TEMPS RANGING
FROM THE MID 60S IN THE HIGHLANDS TO MID 70S ALONG AND EAST OF
I-95.
SHORTWAVE TROUGH OVER THE UPPER MIDWEST ERY SUN IS FCST TO LIFT NEWD
ACROSS THE GREAT LAKES DURING THE DAY. THIS SHORTWAVE ENERGY WILL BE
WEAKENING DURING THIS TIME AS THE UPPER-JET STREAK AHEAD OF THE TROUGH
LIFTS NEWD INTO ERN CANADA. THE MID- ATLANTIC REGION WILL BE
SITUATED IN THE PRE- FRONTAL WARM- MOIST SECTOR ON SUN AS A SFC
COLD FRONT MOVES INTO THE OH VLY.
AFTN TEMPS IN THE LOWER 90S AND DEWPOINTS IN LOWER 70S ON SUN WILL
YIELD A MODERATE AMT OF INSTABILITY...AROUND 1.5-2 KJ/KG...BY THE
AFTN. COVERAGE AND ORGANIZATION OF CONVECTION SHOULD BE BETTER
NORTH AND WEST OF THE REGION...WHERE THE BEST SYNOPTIC LIFT
ASSOCIATED WITH THE TROUGH/COLD FRONT RESIDE. GIVEN THE STEEP LLVL
LAPSE RATES AND APPROACH OF A 30-KT LLVL JET BY EVE...A FEW
STORMS MAY BECOME SEVERE DURING THE PEAK HEATING HRS.
COLD FRONT WILL MOVE THRU SUN NGT. IF FRONT MOVES THRU EARLIER THAN
12Z MODELS INDICATE...THEN ORGANIZED CONVECTION AND A DAMAGING WIND
THREAT MAY EXTEND EWD TOWARD THE WRN TERRAIN AND NRN MD DURING
THE EVE. HOWEVER...ATMOSPHERE WILL BE LESS CONDUCIVE FOR SEVERE
WEATHER FARTHER SOUTH AND EAST WHEN FRONT MOVES THRU SEVERAL HRS
AFTER SUNSET.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AN UPPER-LEVEL TROUGH MOVES OVER THE REGION NEXT WEEK WITH NEAR TO
SLIGHTLY ABOVE NORMAL TEMPS EXPECTED FOR EARLY AUGUST. THE SURFACE
COLD FRONT THAT IS EXPECTED TO MOVE THROUGH THE REGION MONDAY
SHOULD STALL TO THE SOUTH AS A BERMUDA HIGH PERSISTS IN THE
ATLANTIC. LIFT ASSOCIATED WITH THE FRONT MAY PRODUCE SHOWERS AND
THUNDERSTORMS BUT ACTIVITY SHOULD TO THE SOUTH THROUGH THE PERIOD.
GFS AND ECMWF BRING FRONT NORTHWARD ON WEDNESDAY WHICH MAY PRODUCE
SHOWERS AND THUNDERSTORMS ESPECIALLY FOR THE SOUTHERN HALF OF THE
CWA. TROUGH WILL EVENUTALLY FLATTEN AND MOVE EASTWARD TOWARD THE
END OF NEXT WEEK BEFORE THE NEXT WAVE ARRIVES NEXT FRIDAY.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
EXCEPT FOR A STRAY SHOWER...AREA SHOULD BE DRY OVERNIGHT. LIKE
LAST NIGHT...SOME FOG MAY FORM AT MRB/CHO/IAD. MRB WENT DOWN TO
IFR LAST NIGHT...AND LEANED TOWARD PERSISTENCE. CHO RECEIVED RAIN
THIS EVENING...SO IFR MAY BE MORE LIKELY LATE TONIGHT. KEPT IAD IN
MVFR TOWARD SUNRISE. VFR WILL PREVAIL FOR SATURDAY...BUT WILL HAVE
TO WATCH SCATTERED THUNDERSTORMS POPPING UP IN THE AFTERNOON.
A COLD FRONT WILL APPROACH FROM THE NW SUN. SCT STORMS AHEAD OF
THE FRONT SUN AFTN WILL INCREASE IN COVERAGE LATE IN THE DAY AND
AT NGT AS THE COLD FRONT MOVES THRU. TEMPORARY RESTRICTIONS
EXPECTED IN STORMS.
VSBY RESTRICTIONS POSSIBLE IN FOG LATE SUN NGT...ESPECIALLY AT
TERMINALS THAT WERE IMPACTED BY EARLIER STORMS.
AS FRONT LINGERS TO THE SOUTH...VFR CONDITION EXPECTED MOST OF THE
TIME. SHOWERS AND THUNDERSTORMS MAY CAUSE BRIEF PERIODS OF
REDUCED VISBYS MAINLY FOR CHO TOWARDS THE END OF NEXT WEEK. LIGHT
S-SW FLOW EXPECTED THROUGH THE PERIOD.
&&
.MARINE...
RISK OF THUNDERSTORMS HAS DIMINISHED OVER THE WATERS OVERNIGHT.
SOUTHERLY FLOW WILL CHANNEL UP THE BAY...PRODUCING UP TO 15 KT AT
TIMES WITHIN THE MAIN CHANNEL. SCATTERED THUNDERSTORMS MAY PRODUCE
GUSTY WINDS SATURDAY AFTERNOON.
SCA HAS BEEN ISSUED FOR SAT NGT FOR THE MOUTH OF THE TIDAL POTOMAC
RVR AND SRN ZONES OF THE MD CHSPK BAY...WHERE SLY CHANNELING WILL
PRODUCE 20-KT GUSTS.
SCA CONDITIONS POSSIBLE FOR MOST MARINE ZONES AS SLY WINDS INCREASE
AHEAD OF A COLD FRONT. A FEW STORMS AHEAD OF THE FRONT COULD PRODUCE
GUSTY WINDS LATE SUN.
AS FRONT LINGERS SOUTH OF THE WATERS NEXT WEEK...LIGHT SOUTHWESTERLY
FLOW EXPECTED.
&&
.TIDES/COASTAL FLOODING...
WILL HAVE TO WATCH SENSITIVE AREAS SUCH AS ALEXANDRIA AND ANNAPOLIS
AGAIN DURING HIGH TIDE SATURDAY MORNING. IT WOULD TAKE AN ANOMALY
OF AROUND 0.8 TO HIT MINOR TIDAL FLOODING THRESHOLDS AT ANNAPOLIS.
ANOMALY IS AROUND 0.6. THIS HAS BEEN FAIRLY STEADY THUS FAR. WITH
SOUTHERLY WINDS...THERE IS THE CHANCE THIS COULD CREEP UP A LITTLE
MORE...BUT DON/T HAVE THE CONFIDENCE IN HITTING CRITERIA ATTM.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 PM SATURDAY TO 6 AM EDT SUNDAY FOR
ANZ533-534-537-541-543.
&&
$$
BPP/WOODY!/KLEIN
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
135 AM EDT THU AUG 2 2012
.UPDATE...
ISSUED AT 934 PM EDT WED AUG 1 2012
CONVECTIVE TRENDS MAIN ISSUE FOR THE LATE EVENING AND OVERNIGHT. LOW
PRESSURE OVR NORTH END OF LK SUPERIOR WHILE COLD FRONT IS CLOSING IN
ON FAR WESTERN UPR MICHIGAN. THERE ARE TWO MAIN SHORTWAVE TROUGHS
OVR THE REGION. FIRST WAVE IS PUSHING ACROSS EASTERN LK SUPERIOR AND
COMBINED WITH H85 THETA-E ADVECTION HAS DRIVEN SHRA/TSRA THAT HAVE
BEEN ROAMING OVER EASTERN LK SUPERIOR AND FAR EASTERN CWA THIS
EVENING. SECOND WAVE IS PUSHING INTO WESTERN MINNESOTA AND HAS
KICKED OFF COMPLEX OF STRONG TSRA OVER SW MINNESOTA. ANOTHER WAVE
IS UPSTREAM OVR SOUTHERN MANITOBA AND MAY HAVE AFFECT ON WX LATER
TONIGHT.
CONVECTION OVR WEST HALF OF UPR MICHIGAN PRETTY MUCH NIL THIS
EVENING DESPITE HIGHER INSTABILITY /MLCAPES UPWARDS OF 2000 J/KG
AND APPROACHING COLD FRONT. MAIN REASON FOR MINIMAL CONVECTION IS
PROBABLY LARGE AREA OF MINIMUM H7 DWPNT...WHICH IS LIKELY EXTENDING
LOWER INTO THE LOWER LAYERS OF THE ATMOSPHERE. RUC INDICATES
INCREASE OF H7 MOISTURE AFT MIDNIGHT AS THE COLD FRONT PUSHES INTO
CNTRL UPR MICHIGAN. THE INCREASED MOISTURE H85-H7 MOISTURE ADVECTION
INTO THE FRONT IN PRESENSE OF THE UPSTREAM SHORTWAVE OVR MANITOBA
COULD BE ENOUGH TO TRIGGER SHRA/TSRA OVERNIGHT MAINLY OVER THE SOUTH
INTO THE EASTERN CWA. STILL A RISK OF ISOLD STRONGER STORMS AS
INSTIBILITY AND SHEAR REMAIN MORE THAN SUFFICIENT. AFTER LATE
TONIGHT...GOING FLAVOR OF PREVIOUS FCST STILL THERE WITH COLD FRONT
STALLING OUT OVR SOUTH CENTRAL CWA ON THURSDAY. POPS REMAIN SLIGHT
CHANCE FOR NOW FOR THIS...BUT MAY NEED INCREASING LATER TONIGHT ONCE
NEXT UPSTREAM WAVE IS SORTED OUT.
ONLY CHANGE OF NOTE FOR FCST WAS TO RESTRUCTURE POPS THROUGH THE
OVERNIGHT BASED ON LATEST MESOANALYSIS/RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 327 PM EDT WED AUG 1 2012
A 1002MB SFC LOW IS CENTERED JUST NW OF LAKE SUPERIOR WITH AN
ASSOCIATED MID/UPPER LEVEL SHORTWAVE OVERHEAD. A SFC COLD FRONT IS
CURRENTLY STRETCHED FROM THE SFC LOW SW TO FAR NRN MN. ANOTHER
SHORTWAVE RIDING OVER THE UPPER RIDGE OVER THE WRN CONUS WAS LOCATED
JUST N OF LAKE SUPERIOR AT 14Z TODAY...CAUSING THUNDERSTORMS TO MOVE
N OF LAKE SUPERIOR. ANOTHER CLUSTER OF THUNDERSTORMS WAS OVER ERN MN
LATE THIS MORNING...WHERE MORE MOISTURE WAS PRESENT. BY AROUND 17Z
TODAY...THE STORMS MADE THEIR WAY INTO FAR WRN UPPER MI NEAR
IWD...AND ARE NOW /19Z/ LOCATED OVER WRN IRON/SRN HOUGHTON COUNTIES.
A COUPLE OF THE STORMS WERE STRONGER NEAR IWD...AND A COUPLE WERE
SEVERE JUST S OF GOGEBIC COUNTY.
CLEARING BEHIND THESE STORMS...ALONG WITH ALREADY HIGH SFC DEW
PTS...MAY LEAD TO INCREASED INSTABILITY OVER FAR WRN UPPER MI LATE
THIS AFTERNOON. THERE IS A RISK FOR SOME STRONGER THUNDERSTORMS OVER
THE FAR W INTO THIS EVENING. DRY AIR OVER THE AREA HAS LEAD TO LARGE
DCAPES...SO STRONG WINDS WOULD BE A THREAT WITH ANY SIGNIFICANT
CONVECTION. MLCAPES UP TO 2000J/KG WILL BE POSSIBLE WITH 0-6KM SHEAR
OF 30-40KTS...ALSO LEADING TO A HAIL THREAT. MODEL QPF VARIES WIDELY
FROM MODEL TO MODEL...FURTHER LIMITING CONFIDENCE IN COVERAGE THIS
EVENING THROUGH TONIGHT. OVERALL...BEST CHANCES FOR CONVECTION WILL
BE THIS AFTERNOON INTO THIS EVENING ALONG THE WI BORDER OVER THE W.
850MB TEMPS TODAY WERE AROUND 20C...BUT NW WINDS BEHIND THE COLD
FRONT TOMORROW WILL KEEP 850MB TEMPS AROUND 15C S TO 11C N...SO
TEMPS WILL QUITE A BIT COOLER /ESPECIALLY NEAR LAKE SUPERIOR/. THIS
WILL LEAD TO HIGHS IN THE 70S N TO 80S S. SINCE THE COLD FRONT LOOKS
TO BE S OF THE CWA BY 12Z THU...WILL CUT BACK POPS FROM PREVIOUS
SHIFT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 327 PM EDT WED AUG 1 2012
HIGH PRESSURE WILL CONTINUE TO BUILD ACROSS THE UPPER GREAT
LAKES...BEHIND THE COLD FRONT WHICH WILL BE MOVING ACROSS THE LOWER
GREAT LAKES AND NEW ENGLAND STATES. WHILE THE CENTER OF THE SFC LOW
WILL REMAIN TO OUR NE...LIGHT WINDS WILL PREVAIL...WITH SOME RETURN
FLOW OVER THE W HALF CLOSER TO THE NEARING SFC LOW OVER THE PLAINS
STATES THROUGH MANITOBA. NORTHWEST FLOW WILL CONTINUE ALOFT THURSDAY
NIGHT...WITH THE MAIN 500MB LOW STILL SPINNING OVER NE HUDSON BAY/N
QUEBEC...AND THE NEXT LOW PUSHING ACROSS THE PACIFIC NW/SW CANADA.
SLIGHT RIDGING TO ZONAL FLOW FRIDAY...OUT AS THE WESTERN 500MB LOW
DIGS ACROSS THE DAKOTAS. THE LOW WILL CONTINUE TO DEEPEN AS IT
SHIFTS ACROSS N MN/W ONTARIO BY 18Z SATURDAY. THE GFS/CANADIAN ARE
MORE PROGRESSIVE WITH THE 500MB LOW /NEAR JAMES BAY/...WHILE THE
ECMWF IS STILL OVER N LS AND CENTRAL ONTARIO.
WINDS JUST ABOVE THE SFC FRIDAY NIGHT COULD BE QUITE STRONG...WITH
NEARLY UNIDIRECTIONAL SW WINDS OF 30-40KTS AT AND ABOVE 925MB. SOME
DRY AIR AT THE SFC INITIALLY SHOULD PRECLUDE STRONG TS
DEVELOPMENT...BUT COULD DEPEND ON THE LOCATION OF THE WARM FRONT.
MLCAPE VALUES JUMP TO 500-1100J/KG OVER THE W LAND AWAY FROM THE
KEWEENAW PENINUSLA BY 12Z SATURDAY...WITH 45-55KT LLJ OVER THE
ENTIRE W HALF. THIS STRONG WAA SHOULD KEEP TEMPS FROM FALLING MUCH
BELOW 65F...PARTICULARLY OVER THE W HALF DOWNSLOPE LOCATIONS NEAR
LS. 850MB TEMPS JUMP TO AROUND 18C SATURDAY AFTERNOON CWA WIDE UNTIL
THE PASSAGE OF THE COLD FRONT BY MID/LATE AFTERNOON W.
NO MATTER WHICH SOLUTION PANS OUT ALOFT...NW FLOW WILL RETURN BY
SUNDAY NIGHT THROUGH MID DAY TUESDAY. LINGERING CLOUDS ON FAVORABLE
NW WINDS AND 850MB TEMPS OF 7-8C SHOULD KEEP A FEW CLOUDS SET UP N
CENTRAL AND E SUNDAY MORNING. A FEW DIFFICULT TO PREDICT SHORTWAVES
LOOK TO SWING THROUGH OR TO OUR N IN THE FAST NW FLOW. THE LARGE
SCALE TROUGH SET UP FROM CENTRAL CANADA THROUGH THE MID ATLANTIC
WILL BRING MORE ZONAL FLOW TO THE UPPER GREAT LAKES ON WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 134 AM EDT THU AUG 2 2012
A LOW PRESSURE SYSTEM CROSSING NORTHERN PORTIONS OF LAKE SUPERIOR
WILL PUSH A COLD FRONT ACROSS UPR MICHIGAN BY DAYBREAK THIS MORNING.
STILL SOME CONCERN THAT ISOLD SHRA/TSRA COULD AFFECT TAF SITES EARLY
THIS MORNING. AT THIS POINT...BEST CHANCE WOULD PROBABLY BE AT SAW
BEFORE SUNRISE AS COLD FRONT APPROACHES AND ADDITIONAL SUPPORT IS
PROVIDED BY UPPER LEVEL DISTURBANCE. ANY RISK OF SHRA/TSRA WILL BE
OUT OF THE TAF SITES BY MID MORNING AT THE LATEST. ATTN REST OF THE
DAY WILL BE ON POST-FRONTAL LOWER CLOUDS. BASED ON UPSTREAM CIGS IN
MANITOBA AND ONTARIO LAST EVENING AND EARLY THIS MORNING...SCT-BKN
STRATOCU CLOUDS ARE EXPECTED...ESPECIALLY GIVEN DEVELOPING NORTHERLY
WINDS OFF LK SUPERIOR. AFTER A PERIOD OF LOWER CIGS IN THE MVFR
RANGE...EXPECT SKIES TO SCATTER OUT MID-LATE AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE AREA.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 327 PM EDT WED AUG 1 2012
A LOW PRESSURE SYSTEM MOVING THROUGH SOUTHERN CANADA TODAY AND
TONIGHT WILL SWEEP A COLD FRONT ACROSS LAKE SUPERIOR. EXPECT SW
WINDS AHEAD OF THIS FRONT TO GUST TO 20KTS BEFORE SHIFTING TO THE NW
TO 20KTS OVERNIGHT. A HIGH PRESSURE RIDGE WILL THEN SETTLE BACK OVER
LAKE SUPERIOR THURS INTO FRI. A STRONGER LOW PRESSURE SYSTEM
DEVELOPING NEAR LAKE WINNIPEG ON FRIDAY WILL SHIFT ENE TO JAMES BAY
BY SUNDAY MORNING AND SWEEP A COLD FRONT ACROSS LAKE SUPERIOR ON
SATURDAY. WINDS COULD GUST TO 25KTS THIS WEEKEND AS THE SYSTEM MOVES
THROUGH.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...TITUS
LONG TERM...KF
AVIATION...JLA
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS DULUTH MN
1222 AM CDT THU AUG 2 2012
.AVIATION.../06Z TAF ISSUANCE/
SHOWERS OVER THE SOUTHERN TERMINALS WILL MOVE OUT OF BRD BY 07Z
AND 09Z AT HYR. SHOWERS NORTH OF INL WILL MOVE AWAY BY 07Z. SKIES
WILL PARTIALLY CLEAR BY DAYBREAK WHICH MAY LEAD TO A FEW FOG
PATCHES. HAVE TEMPO GROUPS FOR VISIBILITIES BETWEEN 3SM AND 5SM TO
ACCOUNT FOR THIS. VFR CONDITIONS WILL PREVAIL THROUGH THE DAYLIGHT
HOURS ON WEDNESDAY WITH NORTHWESTERLY WINDS UNDER 10 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 740 PM CDT WED AUG 1 2012/
SHORT TERM...
CURRENTLY...NO THUNDERSTORMS WERE OCCURRING OVER THE CWA. WE HAD A
BRIEF STORM DEVELOP OVER SOUTHERN PINE COUNTY AROUND 2330Z IN AN
AREA OF ENHANCED CU THAT HAS BEEN MOVING EAST OVER THE PAST COUPLE
HOURS. STABILITY IS IMPRESSIVE THIS EVENING...WITH MUCAPE AROUND
3000J/KG OVER NORTHWEST WISCONSIN...TO A 1000 J/KG OVER THE
INTERNATIONAL BORDER REGION. HOWEVER...LIFT IS QUITE MARGINAL WITH
MID LEVEL ENERGY FURTHER NORTH AND WEST PASSING THROUGH SOUTHERN
MANITOBA...AND STRONGER LOW LEVEL FGEN FORCING FURTHER SOUTH OVER
SOUTHERN MINNESOTA INTO SOUTH DAKOTA. THERE IS SOME WEAK LOW LEVEL
CONVERGENCE...SEEN IN THE SURFACE OBS...WITH W-NW FLOW AT
KRZN/KDLH/K04W AND LIGHT SW FLOW AT KPBH AND KASX. THE RAP SHOWS
LITTLE 925MB CONVERGENCE. WE CAN`T RULE OUT A THUNDERSTORM OVER THE
NEXT FEW HOURS OVER NORTHWEST WISCONSIN AS THE WEAK LOW LEVEL
CONVERGENCE MOVES THROUGH. WE ALSO COULD GET BRUSHED WITH THE
COMPLEX OF STORMS THAT WERE AFFECTING SOUTHERN/CENTRAL MN AND
SOUTH DAKOTA AS IT CONTINUES E-SE. HOWEVER...CHANCES OF THAT ARE
LOW.
FURTHER NORTH...A SHORTWAVE SEEN ON SATELLITE AND IN THE RAP`S 1.5
PV SURFACE...WILL AFFECT FAR NORTHERN MINNESOTA AND COULD BRING A
FEW SHOWER OR STORMS TO THAT AREA LATER THIS EVENING. WE MAY HAVE
TO EXTEND AND EVEN INCREASE POPS A BIT AFTER 03Z IN THE FAR NORTH.
PREV DISCUSSION... /ISSUED 626 PM CDT WED AUG 1 2012/
AVIATION.../0Z TAF ISSUANCE/
COLD FRONT HAS MOVED THROUGH THE TERMINALS WITH NORTHWESTERLY
WINDS. MAIN AREA OF SHOWER AND THUNDERSTORM ACTIVITY WILL STAY TO
OUR SOUTH. HAVE INCLUDED SOME TEMPO GROUPS TO ACCOUNT FOR THE
DEVELOPMENT OF PATCHY FOG BEFORE DAWN. VISIBILITIES MAY FALL TO
1SM AT HIB...DLH...AND HYR. WINDS WILL STAY LIGHT NORTHWESTERLY
THROUGH THE TAF FORECAST PERIOD.
PREV DISCUSSION... /ISSUED ISSUED BY NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN/
DISCUSSION...
PRIMARY FORECAST CONCERNS ARE CHANCES FOR TSRA THIS LATE THIS
AFTERNOON INTO THIS EVENING AS THE COLD FRONT MOVES THROUGH THE
REMAINDER OF THE AREA... THEN CHANCES FOR MORE WIDESPREAD
SHRA/TSRA FRIDAY NIGHT INTO SATURDAY MORNING AS THE NEXT SHORTWAVE
AND COLD FRONT MOVE THROUGH THE AREA. LATEST WATER VAPOR IMAGERY
SHOWS THE SAME BASIC UPPER AIR PATTERN WE/VE SEEN FOR MUCH OF THE
SUMMER... WITH A BROAD UPPER RIDGE ENCOMPASSING MOST OF THE
CENTRAL CONUS. THE SHORTWAVE CURRENTLY RIDING ALONG THE
US/CANADIAN BORDER NEAR THE MONTANA/NORTH DAKOTA BORDER WILL
CONTINUE TO DRIVE EAST TONIGHT... HELPING TO FINALLY PUSH THE COLD
FRONT CURRENTLY OVER MINNESOTA EAST THROUGH THE REMAINDER OF THE
AREA. SPC MESOANALYSIS SHOWS GOOD INSTABILITY ALONG AHEAD OF THE
FRONT... WITH MLCAPE AOA 2500 J/KG. SOME INSTABILITY LAGS THE
SURFACE BOUNDARY AS WELL... WHICH IS HELPING TO KEEP ACTIVITY
GOING TO THE WEST... AND NECESSITATES LEAVING POPS IN THE FORECAST
ACROSS THE AREA THROUGH AT LEAST EARLY EVENING AS THE UPPER WAVE
MOVES TOWARD THE FORECAST AREA. WE SHOULD MANAGE TO CLEAR THE PCPN
OUT OF ALL BUT PERHAPS THE SOUTHEAST PORTION OF THE AREA OVERNIGHT
AS THE FRONT CONTINUES EAST AND A WEAK SURFACE RIDGE TRIES TO WORK
INTO THE AREA. THERE COULD BE SOME AREAS OF FOG LATE TONIGHT WITH
WINDS DYING AND CLOUD COVER DECREASING... BUT THAT WILL LIKELY DEPEND ON
ANY RE-WETTING OF THE GROUND WHICH CAN OCCUR WITH PCPN THROUGH
EARLY THIS EVENING... SO OPTED TO LEAVE IT OUT OF THE FORECAST FOR
NOW. IT SHOULD BE PARTLY CLOUDY AND DRY OVER MOST OF THE AREA ON
THURSDAY AS THE SURFACE HIGH DRIFTS ACROSS THE AREA. HOWEVER...
THE ARROWHEAD COULD SEE SOME AFTERNOON PCPN DEVELOP GIVEN BETTER
PROXIMITY TO THE MID-LEVEL COLD POOL MOVING NORTH AND NORTHEAST OF
THE AREA DURING THE DAY.
AFTER TOMORROW ATTENTION WILL TURN TOWARD THE SHORTWAVE CURRENTLY
DROPPING THROUGH BRITISH COLUMBIA. THIS WAVE IS EXPECTED TO
CONTINUE EAST-SOUTHEAST THROUGH THE NEXT FEW DAYS... WORKING INTO
THE HIGH PLAINS BY FRIDAY... THEN CONTINUING EAST ACROSS THE
FORECAST AREA SATURDAY INTO SUNDAY. DECENT RETURN FLOW AND WARM
ADVECTION IS EXPECTED AHEAD OF THIS FEATURE... AND THE NAM...
GFS... AND ECMWF ARE ARE IN REASONABLY AGREEMENT ON THE DEGREE OF
INSTABILITY AND FORCING ASSOCIATED WITH ITS PASSAGE. THERE ARE
STILL SOME TIMING DIFFERENCES... WHICH RESULT IN HAVING A LONGER
PERIOD BLANKETED WITH POPS THAN WILL LIKELY OCCUR... BUT AS THINGS
GET CLOSER IN TIME THOSE WILL BE REFINED AND LIKELY INCREASED FOR
THE FROPA AND SHORTWAVE ARRIVAL WHICH CURRENTLY LOOKS TO OCCUR
FRIDAY NIGHT INTO SATURDAY MORNING. INCLUDED CHANCE-LIKELY POPS
WITH THIS SYSTEM FRIDAY NIGHT INTO SATURDAY... THEN TAPERED THING
BACK SATURDAY NIGHT AS THE FRONT MOVES WELL TO THE EAST BUT
CYCLONIC BOUNDARY LAYER FLOW AND AND MID-UPPER COLD POOL LINGER
OVER THE AREA. IMPRESSIVE RIDGING LOOKS TO ARRIVE AND KEEP THINGS
BENIGN SUNDAY THROUGH MONDAY... WITH A SMALL CHANCE FOR SOME PCPN
MONDAY NIGHT AS A WEAK FRONTAL BOUNDARY DROPS SOUTH THROUGH THE
AREA. THE MAIN CHANCES LOOK TO BE OVER THE SOUTHERN PORTION OF THE
AREA WITH THAT FEATURE... SINCE IT APPEARS IT WILL TAKE A WHILE
FOR THINGS TO SATURATE IF THEY DO AT ALL GIVEN THE DRYNESS OF THE
ANTECEDENT AIRMASS. PCPN CHANCES SHOULD RETURN BY THE MIDDLE OF
THE WEEK AS WE GET ONTO THE BACKSIDE OF THE SURFACE HIGH AND A FEW
SHORTWAVES DROP SOUTHEAST INTO THE AREA ON THE PREVAILING
NORTHWEST FLOW.
&&
.POINT TEMPS/POPS...
DLH 64 79 60 77 / 20 10 10 30
INL 60 79 60 78 / 30 10 20 50
BRD 63 84 62 84 / 30 10 10 50
HYR 65 82 60 82 / 30 10 10 20
ASX 68 77 61 78 / 20 10 0 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...KK
AREA FORECAST DISCUSSION
NWS GLASGOW MT
945 PM MDT FRI AUG 3 2012
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUNDAY...
PREVIOUS DISCUSSION...GOING FORECAST IN OVERALL GOOD SHAPE.
SHOWERS CONTINUE TO STREAM INTO THE NORTHERN ZONES...DRIVEN BY A
LARGE UPPER LOW. HRRR MODEL SEEMS TO BE DOING A GOOD JOB WITH THE
CURRENT PATTERN...THUS FAVORED IT FOR THE UPDATE. BIGGEST CHANGES
WERE TO DECREASE POPS ACROSS THE SOUTH AND TO INCREASE SHOWER
COVERAGE ACROSS THE NORTHEAST. WINDS HAVE ALSO DECREASED REGION
WIDE...THUS THE LAKE WIND ADVISORY WAS CANCELLED EARLY. GILCHRIST
A LARGE
MIDLEVEL LOW IS CURRENTLY SPINNING OVER NORTHEAST MONTANA. THIS
SYSTEM PULLED A COLD FRONT THROUGH YESTERDAY AND BROUGHT
WIDESPREAD SHOWERS AND CLOUD COVER TO THE REGION. WITH CLOUD COVER
AND RAIN ACTIVITY...HIGH TEMPERATURES HAVE NOT BEEN REACHING
FORECAST VALUES...EXCEPT IN THOSE AREAS WHICH SAW BREAKS IN THE
OVERCAST. SOME THUNDERSHOWER ACTIVITY HAS ALSO BEEN NOTED OVER
PHILLIPS COUNTY WHICH SAW SOME BREAKS IN CLOUDS AND SURFACE
WARMING. RADAR TRENDS AND RAP GUIDANCE CONTINUES SHOWER ACTIVITY
WITH SOME ISOLATED THUNDER THROUGH MIDNIGHT WITH SHOWERS ENDING
GRADUALLY FROM WEST TO EAST AS THE SYSTEM PROGRESSES EASTWARD.
WINDS HAVE BEEN BARELY STRONG ENOUGH TO JUSTIFY CONTINUING THE
LAKE WIND ADVISORY...HOWEVER...THEY HAVE BEEN CONSISTENTLY OVER
20MPH AT A NUMBER OF STATIONS AROUND THE LAKE. WINDS WILL DECLINE
BY OR SHORTLY AFTER NIGHTFALL AS SURFACE MIXING DECLINES AND
SURFACE PRESSURE RELAXES WITH THE PASSAGE OF THE WEATHER SYSTEM.
IN THE WAKE OF THIS SYSTEM...THE NEXT RIDGE MOVES IN FAIRLY
QUICKLY AND WILL BEGIN TO WARM THE REGION BY SUNDAY. MARTIN
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...
A FEW CHANGES IN THE EXTENDED FORECAST DROPPED POPS ACROSS THE
WESTERN ZONES TUESDAY NIGHT. DECIDED TO STAND PAT WITH THE POPS THAT
WERE IN THE FORECAST FOR WEDNESDAY THROUGH FRIDAY EVEN THOUGH
MODELS ARE HINTING AT A RATHER LARGE RIDGE ACROSS CENTRAL AND
EASTERN MONTANA STARTING ON TUESDAY THROUGH THURSDAY WITH A
SHORTWAVE MOVING ACROSS ALBERTA AND SOUTHERN SASKATCHEWAN THURSDAY
NIGHT THROUGH FRIDAY. MODELS ALL SHOW THIS SHORTWAVE BUT DIFFER ON
WHETHER IT WILL PRODUCE ANY RAINFALL.
THE PRIMARY DIFFERENCE IS THAT THE MODELS ARE STRENGTHENING THE
MID WEEK UPPER RIDGE SO THAT IS WHY I DECIDE TO LOWER POPS TUESDAY
NIGHT THROUGH THURSDAY. THE 12Z MODEL RUNS ARE IN BETTER AGREEMENT
WITH THIS FEATURE THEN THEY WERE WITH THE 00Z MODELS RUNS. RSMITH
PREVIOUS DISCUSSION...THE EXTENDED FORECAST SHOWS LITTLE CHANGE AGAIN
TONIGHT FROM THE LAST FEW MODEL RUNS. THE BEGINNING OF THE PERIOD
SUNDAY NIGHT/MONDAY MORNING HAS RIDGING BUILDING INTO NORTHEAST
MONTANA. THIS WILL HOLD OVER THE REGION THROUGH TUESDAY. THEN THE
RIDGE MOVES A TOUCH SOUTH ALLOWING SOME RIPPLES IN THE UPPER FLOW
TO COME INTO PLAY. STILL NO MAJOR EVENT TO POINT TOWARDS A BETTER
CHANCE OF CONVECTION OVER ANOTHER SHORTWAVE. THEREFORE KEPT THE
POPS LOW MID WEEK THROUGH THE END OF THE EXTENDED.
TEMPERATURES WILL CONTINUE WITH AN ABOVE NORMAL TREND FOR THE
REGION THROUGH THE ENTIRE PERIOD. PROTON
&&
.AVIATION...
PRIMARILY VFR CEILINGS BUT COULD HAVE TEMPORARY MVFR CEILING
ACROSS THE TERMINALS DURING THE EVENING WITH CEILING DROPPING
BELOW 3000 FT AGL NEAR ANY RAIN SHOWERS. EXPECT ISOLATED TO SCATTERED
VICINITY SHOWERS TO CONTINUE ACROSS THE TERMINALS THROUGH TONIGHT.
NORTHWEST WINDS WILL DROP TO NEAR 10 KNOTS THIS EVENING INCREASING
SLIGHTLY TO 10 TO 20 KTS TOMORROW AFTERNOON. GAH/RAS
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS HASTINGS NE
333 PM CDT THU AUG 2 2012
.SHORT TERM...TONIGHT THROUGH FRIDAY AFTERNOON. CONCERN IN THE NEXT
24 HRS WILL BE SLIGHT CHANCES FOR TSTMS EARLY ON ALONG WITH HIGH
TEMPERATURES FOR FRIDAY.
CURRENT WATER VAPOR IMAGERY ALONG WITH UPPER AIR AND WIND PROFILER
DATA SHOW UPPER RIDGE NOW ANCHORED OVER TEXAS...AN UPPER LOW
DROPPING SSE AND INTO THE WESTERN PART OF ALBERTA...PUTTING THE
PLAINS IN WESTERLY FLOW. ONE CAN ALSO SEE THE SUBTROPICAL MOISTURE
TAP STREAMING NORTH ACROSS WESTERN MEXICO...INTO THE FOUR CORNERS
REGION AND THEN SWINGING EAST AROUND THE HIGH ACROSS OUR REGION.
AT THE SURFACE...PRESSURE GRADIENT VERY WEAK ACROSS NEB/KS WITH ONE
WEAK SURFACE LOW OVER OKLAHOMA AND ANOTHER ONE SITUATED ACROSS
EASTERN MT/WY. SURFACE DEWPOINTS REMAIN FAIRLY HIGH OVER THE CWA
RANGING FROM THE MID TO UPPER 60S AT LUNCHTIME. WEAK CONVECTIVE
ACTIVITY HAS NEVER QUITE FADED AWAY IN OUR KS CWA ALTHOUGH DOUBT
ANYTHING IS REACHING THE GROUND. CLOUD COVER ACROSS OUR SOUTHERN CWA
HAS BEEN HOLDING IN A LITTLE LONGER THAN ANTICIPATED AND WITH SOME
RE-DEVELOPMENT TO THE WEST...MAY NOT SEE HIGHS QUITE AS WARM AS
EXPECT. ALSO WEAK CELLS MOVING ACROSS NORTHERN NEBRASKA HAVE ALSO
HUNG IN DURING THE DAY. SOME OF THE HOURLY HRRR MODEL RUNS HAVE
SHOWN THIS HANGING TOGETHER AND MOVING INTO THE WESTERN PART OF THE
CWA LATER THIS AFTERNOON. WILL NEED TO MONITOR THIS OVER THE NEXT
FEW HOURS.
BELIEVE OUR BETTER...ALTHOUGH NOT GREAT...CHANCES FOR RAIN WILL BE
LATER THIS EVENING AND OVERNIGHT. CHECKING OUT THE NEEDED
INGREDIENTS...WE HAVE ADEQUATE INSTABILITY...MOISTURE AND SHEAR AT
PRESENT BUT SEEM TO BE LACKING A FORCING MECHANISM. BELIEVE THE
SURFACE TROUGH ALONG THE FRONT RANGE MAY FIT THE BILL AND WILL
MONITOR CONVECTIVE DEVELOPMENT OUT WEST LATER THIS AFTERNOON.
QUESTION THEN BECOMES WILL THIS ACTIVITY MAKE IT FAR ENOUGH EAST TO
AFFECT OUR CWA. EARLY LOOK AT HRRR SHOWS THIS IS POSSIBLE AND WILL
CHECK OUT THE 4KM WRF WHEN IT ARRIVES. SEEMS LIKE BETTER LOW LEVEL
JET REMAINS WEST OVERNIGHT.
ON FRIDAY AFTERNOON...THE UPPER LOW NOTED ABOVE WILL SHOULD BE
CENTERED SOMEWHERE NEAR THE MT/NDAK/CANADA BORDER. THIS IS A DECENT
WAVE AND SHOULD PROVIDE GOOD HEIGHT FALLS AND COOLER TEMPS ALOFT TO
THE NORTHERN PLAINS. IT WILL ALSO PUSH A COLD FRONT INTO OUR NW CWA
BY LATE AFTN OR EARLY EVENING. EXPECT SOME COMPRESSIONAL HEATING
AHEAD OF THE FRONT AND WITH SURFACE WINDS BECOMING SOUTH TO SSW
ANOTHER HOT DAY WILL BE IN STORE. DO NOT PLAN ON ISSUING ANY HEAT
HEADLINES AS APPARENT TEMPERATURE VALUES FORECAST TO BE BETWEEN 98
AND 102 DEGREES IN THE SOUTHERN CWA. NOT SURE IF CONVECTION WILL
BREAK OUT LATE FRIDAY AFTERNOON OR HOLD OFF UNTIL THE EVENING AS
MOST MODELS SHOWING THE BULK OF THE PRECIPITATION BEING POST
FRONTAL. IF I DO PUT IN AFTERNOON POPS...IT WILL MAINLY BE IN THE
NORTHWEST AND WEST PART OF THE CWA.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY.
CONCERNS FOR THE MID AND LONG TERM PERIOD WILL AGAIN FOCUS ON
CHANCES FOR THUNDERSTORMS AS WELL AS COOLER TEMPERATURES FOR THE
WEEKEND.
BEGINNING THE MID TERM PERIOD...THE MODELS REMAIN IN FAIRLY
CONSISTENT AGREEMENT AS THE UPPER LEVEL LOW CONTINUES TO SHIFT
EASTWARD ACROSS PORTIONS OF MONTANA AND NORTH DAKOTA. AT THE
SURFACE...A LARGE AREA OF LOW PRESSURE ALSO CONTINUES TO PUSH
EASTWARD...WITH AN ASSOCIATED COLD FRONTAL BOUNDARY KNOCKING ON OUR
DOORSTEP BY FRIDAY EVENING. THUNDERSTORM CHANCES CONTINUE INTO THE
OVERNIGHT HOURS...WITH THE POSSIBILITY OF A FEW STRONG STORMS IN THE
EARLY EVENING. BY LATE SATURDAY MORNING...THE FRONTAL BOUNDARY
SHOULD BEGIN TO SAG SOUTHEAST OUT OF THE REGION WITH LINGERING
SLIGHT CHANCES FOR SHOWERS AND THUNDERSTORMS ALONG THE ELEVATED
BOUNDARY. WITH FRONTAL PASSAGE OVERNIGHT FRIDAY...HIGH PRESSURE AND
COOLER TEMPERATURES WILL SINK INTO THE REGION ALONG WITH NORTH
WINDS. MUCH COOLER 850 TEMPERATURES ON THE ORDER OF 10 DEGREES
COOLER THAN PREVIOUS DAYS WILL HELP DRASTICALLY REDUCE HIGH
TEMPERATURES. A VERY NICE WEEKEND IS IN STORE WITH HIGHS IN THE MID
TO UPPER 80S.
BY THE BEGINNING OF THE WORKWEEK...THE UPPER LEVEL RIDGE WILL BEGIN
TO BUILD BACK IN ACROSS THE ROCKIES...RESULTING IN NORTHWEST FLOW
THROUGH THE EXTENDED PERIOD. A DRY FORECAST IS EXPECTED THROUGH THE
BEGINNING OF THE WORKWEEK AS THE CENTRAL PLAINS REMAIN UNDER SURFACE
HIGH PRESSURE.
HOWEVER...TOWARDS THE END OF THE PERIOD...A FEW SHORT WAVE
PERTURBATIONS ROUND THE EASTERN EDGE OF THE UPPER LEVEL RIDGE...AND
COMBINED WITH A SURFACE TROUGH AXIS ALONG THE FRONT RANGE WILL HELP
GENERATE SOME CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
EXTENDED. CONTINUED SLIGHT CHANCES THROUGH THE PERIOD...MONDAY AND
AGAIN TUESDAY NIGHT THROUGH WEDNESDAY.
AS FOR TEMPERATURES...ALTHOUGH MUCH OF THE WARMER 850 TEMPERATURES
REMAIN FARTHER WEST ACROSS THE ROCKIES...EXPECT A RISE IN
TEMPERATURES THROUGH THE WORKWEEK. CONTINUED WITH HIGHS IN THE MID
TO UPPER 90S.
&&
.PREV DISCUSSION... /ISSUED 1213 PM CDT THU AUG 2 2012/
AVIATION...EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST
PERIOD. THERE IS JUST A SLIGHT CHANCE FOR THUNDERSTORMS LATER THIS
AFTERNOON AND INTO THE OVERNIGHT HOURS BUT LOOKS TO BE 20 PERCENT
SO WILL LEAVE OUT OF TAF. OTHERWISE WINDS WILL REMAIN LIGHT FOR
MOST OF THE PERIOD ALTHOUGH THEY SHOULD BEGIN TO PICK UP OUT OF
THE SOUTH A BIT BY MID MORNING FRIDAY AS THE PRESSURE GRADIENT
TIGHTENS UP WITH APPROACHING COLD FRONT MOVING IN FROM THE
NORTHWEST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...EWALD
LONG TERM...SALTZMAN
AREA FORECAST DISCUSSION...UPDATED
NWS OMAHA/VALLEY NE
1228 PM CDT THU AUG 2 2012
.UPDATE...
&&
.AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS WILL PREVAIL THRU THE 24HR FCST PD.
DEE
PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/
DISCUSSION...
SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH
SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER
LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA
LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS
ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR
TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY
IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH
UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN
BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE
THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE
IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY
THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN
COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR
THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET
WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK
OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS
INTO THE UPPER 90S IF NOT LOWER 100S.
A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY
NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL
DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY
00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY.
SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD
FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING.
CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO
SATURDAY MORNING.
COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE
80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL
FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE
BUILDS TO OUR WEST.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
626 AM CDT THU AUG 2 2012
.AVIATION...
12Z TAFS FOR KOFK...KLNK AND KOMA.
VFR CONDITIONS ARE FORECAST THROUGH FRIDAY MORNING. THINNING MID
AND HIGH CLOUDINESS CAN BE EXPECTED THROUGH THE AFTERNOON WITH
GENERALLY LIGHT NORTHEAST WINDS UNDER 10KTS.
DERGAN
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT THU AUG 2 2012/
DISCUSSION...
SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH
SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER
LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA
LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS
ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR
TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY
IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH
UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN
BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE
THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE
IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY
THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN
COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR
THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET
WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK
OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS
INTO THE UPPER 90S IF NOT LOWER 100S.
A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY
NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL
DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY
00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY.
SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD
FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING.
CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO
SATURDAY MORNING.
COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE
80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL
FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE
BUILDS TO OUR WEST.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
348 AM CDT THU AUG 2 2012
.DISCUSSION...
SCATTERED SHOWERS CONTINUE TO MOVE EAST/SOUTHEAST THROUGH
SOUTHEAST NEBRASKA ASSOCIATED WITH A PASSING SFC TROF AND UPPER
LEVEL VORT MAX. DO EXPECT THIS ACTIVITY TO PUSH OUT OF THE CWA
LATER THIS MORNING AS LATEST HRRR SUGGESTS. 06Z NAM LINGERS
ACTIVITY ACROSS OUR EAST INTO THE AFTERNOON BUT BASED ON RADAR
TRENDS...FEEL ACTIVITY WILL WANE THIS MORNING. ANOTHER WARM DAY
IS EXPECTED WITH HIGHS TOPPING OUT IN THE MID TO UPPER 90S. WITH
UNFAVORABLE MIXING IN EASTERLY LOW LEVEL FLOW...WE SHOULD REMAIN
BELOW THE 100 DEGREE MARK. A WEAK SHORTWAVE IS FORECAST TO SLIDE
THRU NEARLY ZONAL MID/UPPER LEVEL FLOW AND CONVECTION IS POSSIBLE
IN UPSLOPE FLOW ACROSS WESTERN NEBRASKA LATE THIS AFTERNOON/EARLY
THIS EVENING. THIS COULD SPREAD AS FAR EAST AS OUR WESTERN
COUNTIES THIS EVENING. HAVE ADDED A SMALL POP TO ACCOUNT FOR
THIS. OTHERWISE...MUCH OF THE OVERNIGHT SHOULD BE FAIRLY QUIET
WITH STRONG WARM AIR ADVECTION UNDERWAY INTO FRIDAY. DESPITE LACK
OF STRONG MIXING WINDS...AMPLE HEATING SHOULD PUSH FRIDAY HIGHS
INTO THE UPPER 90S IF NOT LOWER 100S.
A VIGOROUS SHORTWAVE WILL DROP OVER THE NORTHERN PLAINS FRIDAY
NIGHT PUSHING A COLD FRONT INTO THE CENTRAL PLAINS. LATEST MODEL
DATA SHOWS THAT THIS FRONT SHOULD ENTER INTO THE NORTHERN CWA BY
00-03Z SATURDAY AND MOVE SOUTH OF THE CWA BY 12-15Z SATURDAY.
SHOWERS/TSTMS ARE EXPECTED TO DEVELOP TO OUR NORTH ALONG THE COLD
FRONT FRIDAY AFTERNOON AND SPREAD INTO THE NRN CWA FRIDAY EVENING.
CONVECTION SHOULD CONTINUE ALONG AND BEHIND THE BOUNDARY INTO
SATURDAY MORNING.
COOLER TEMPERATURES TO FOLLOW WITH HIGHS ON SATURDAY ONLY IN THE
80S AS SURFACE HIGH PRESSURE BUILDS SOUTH. NORTHWEST UPPER LEVEL
FLOW IS EXPECTED THRU THE REMAINDER OF THE FORECAST AS UPPER RIDGE
BUILDS TO OUR WEST.
&&
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY
GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND
KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA
THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS
MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON
INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO
INCLUDE PAST 12Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1154 PM CDT WED AUG 1 2012
.AVIATION...
06Z TAFS FOR KOMA...KLNK...AND KOFK.
SHRA/TSRA CURRENTLY IN THE KOFK AREA. OUTFLOW FROM THE STORMS MAY
GENERATE SOME NORTHWEST WINDS 10 TO 20KTS AS IT GETS TO KOMA AND
KLNK. INCLUDED THIS IN THE TAF AS WELL AS SHRA AND ISOLATED TSRA
THROUGH 11Z. CONTINUED VFR CONDITIONS...HOWEVER MVFR CONDITIONS
MAY DEVELOP WITH SOME OF THE STORMS. STORMS MAY TRY TO HANG ON
INTO THE MORNING HOURS...HOWEVER CONFIDENCE LOW ENOUGH NOT TO
INCLUDE PAST 12Z.
&&
.PREV DISCUSSION... /ISSUED 1004 PM CDT WED AUG 1 2012/
UPDATE...
DID AN EVENING UPDATE A LITTLE EARLIER TO ACCOUNT FOR HIGHER POPS
IN THE NORTHEAST AND CONTINUED SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS FARTHER SOUTHEAST OVERNIGHT.
DISCUSSION...
THE EVENING OAX SOUNDING WAS ON THE DRY SIDE WITH LESS THAN ONE
INCH PRECIP WATER...LBF HOWEVER HAD A MUCH MORE FAVORABLE SOUNDING
WITH AROUND 3200 J/KG FOR CAPE AND LITTLE CINH AND 1.34 FOR PRECIP
WATER. THE MOISTURE TRANSPORT VECTORS CONTINUE TO BRING THE
MOISTURE EASTWARD AND SOUTHWARD...SO SCATTERED POPS STILL SEEM ON
TRACK. GUSTY WINDS ARE POSSIBLE WITH DOWNDRAFT CAPE OF 1800 J/KG.
SO FAR HAVE HAD REPORTS OF 40 TO 50 MPH NEAR NELIGH. THE NEW NAM
TRIES TO HOLD ON TO THE PRECIPITATION THURSDAY MORNING FARTHER
NORTH SO THIS WILL NEED TO BE ASSESSED.
&&
PREV DISCUSSION... /ISSUED 501 PM CDT WED AUG 1 2012/
DISCUSSION...
IT APPEARS THAT A SHORT REPRIEVE FROM THE OPPRESSIVE DRY CONDITIONS
THAT HAVE PLAGUED US AS OF LATE IS ON THE HORIZON AS A COUPLE OF COLD
FRONTS APPROACH THE PLAINS. RADAR LOOP WAS SHOWING PCPN ACTIVITY OVER
WESTERN NEBRASKA AND PARTS OF SOUTH DAKOTA WHILE LATEST OBS WERE
DEPICTING A BNDRY EXTENDING ALONG THE ND/SD BORDER WITH CAA SLOWLY
SPREADING SWD OVER NRN SD. THE BIG QUESTION IS WILL THIS RESULT IN
PCPN OVER THE CWA LATER TONIGHT. IT SEEMS THE MODELS ARE TRYING TO
STALL THE FRONT IN THE VICINITY OF THE NRN CWA...BUT GOOD CHUNK OF
DPVA DOES CROSS THE CWA...AND WITH STOUT 315K UPGLIDE NOT
UNREASONABLE AT THIS POINT TO EXPECT SOME HIGH BASED ACTIVITY
DEVELOPING. LATEST HRRR SEEMS TO HAVE A DECENT HANDLE ON THINGS...
WHICH SUGGEST ACTIVITY COULD GET INTO EASTERN NEBRASKA BEFORE
MIDNIGHT.
CHANCES FOR ANOTHER ROUND PCPN ARE ON TAP HEADING INTO THE
WEEKEND. MODELS ARE IN VERY GOOD AGREEMENT THAT UPSTREAM SHORTWAVE
TROF OVER BRITISH COLUMBIA WILL SLIGHTLY BREAK DOWN THE CONUS
UPPER RIDGE AS IT DROPS INTO THE LOWER 48. THE THERMAL GRADIENT
WITH THE ATTENDANT COLD FRONT WILL BE MORE STOUT IN NATURE. WITH
DECENT ENVIRONMENTAL MOISTURE ON HAND... PRECIP WATER VALUES
AROUND 2"/KI OF 40...IS REASONABLE TO MAINTAIN POPS FRIDAY NIGHT.
POSSIBLE LINGERING ACTIVITY THEN SATURDAY MORNING OVER THE SRN
CWA. RELATIVELY COOLER AFTN HIGHS IN THE MID 80S THEN SUNDAY
AFTERNOON. HEADING INTO NEXT WEEK...THE SITUATION LOOKS RATHER
BLEAK WITH DRY CONDITIONS AND HIGH TEMPS PUSHING BACK TO THE
MID/UPPER 90S AS AN UPPER RIDGE RETURNS OVER THE CONUS.
DEE/BCM
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION UPDATE
NWS LAS VEGAS NV
1054 PM PDT WED AUG 1 2012
.SYNOPSIS...A DISTURBANCE IN THE ATMOSPHERE COMBINED WITH ABUNDANT
MOISTURE AND INSTABILITY WILL RESULT IN SHOWERS AND THUNDERSTORMS
AROUND AT TIMES THROUGH THIS WEEKEND. ALTHOUGH HEAVY RAIN WILL BE
THE PRIMARY THREAT WITH HEAVIER STORMS...GUSTY WINDS AND HAIL MAY
ALSO OCCUR. BY EARLY NEXT WEEK DRIER AIR LOOKS TO SLOWLY SPREAD EAST
ACROSS THE AREA WHICH SHOULD DECREASE THE CHANCES FOR THUNDERSTORMS
AND ALSO RESULT IN A WARMING TREND.
&&
.UPDATE...
THE OUTFLOW BOUNDARY ASSOCIATED WITH THE LINE OF THUNDERSTORMS
PREVIOUSLY EXPECTED TO PASS ACROSS THE LAS VEGAS VALLEY AND FURTHER
SOUTH HAVE DISSIPATED AS THE OUTFLOW BOUNDARY ASSOCIATED WITH THE
STORMS HAD MOVED OUT TOO FAR AHEAD OF THE LINE OF STORMS...AND CUT
OFF FAVORABLE INFLOW TO STORMS DESPITE LIS BETWEEN -3 AND -5 AND
CAPE VALUES FROM 1000 TO 2000 J/KG. THE FLASH FLOOD WATCH HAS BEEN
CANCELLED...AND ANY MENTION OF SHOWERS OR THUNDERSTORMS HAVE BEEN
REMOVED FROM THE OVERNIGHT FORECAST. STILL EXPECT SUFFICIENT
MOISTURE TO BE IN PLACE FOR A CHANCE OF CONVECTION TOMORROW...BUT
NEED TO FURTHER ASSESS HOW MUCH ANY EXPECTED WARMING AND DRY AIR
MOVING IN ALOFT WILL MITIGATE DEVELOPMENT.
-KENNEDY-
&&
.AVIATION...FOR MCCARRAN...NO SIGNIFICANT WEATHER IS EXPECTED THE
REMAINDER OF THE NIGHT. THERE WILL BE A CHANCE OF THUNDERSTORMS ONCE
AGAIN ON THURSDAY...AS SUFFICIENT MOISTURE REMAINS IN PLACE FOR
THUNDERSTORM DEVELOPMENT. THUNDERSTORMS WILL DEVELOP INITIALLY OVER
HIGHER TERRAIN. OUTSIDE OF ANY THUNDERSTORM OUTFLOWS...WINDS WILL BE
RELATIVELY LIGHT.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...NO SIGNIFICANT WEATHER IS EXPECTED THE REMAINDER OF THE
NIGHT AS THUNDERSTORMS HAVE DISSIPATED ACROSS THE FORECAST AREA.
THERE WILL BE A CHANCE OF THUNDERSTORMS ACROSS THE REGION AGAIN
TOMORROW...AS SUFFICIENT MOISTURE REMAINS IN PLACE. THUNDERSTORMS
WILL DEVELOP INITIALLY OVER HIGHER TERRAIN. OUTSIDE OF ANY
THUNDERSTORM OUTFLOWS...WINDS WILL BE RELATIVELY LIGHT.
-KENNEDY-
&&
.PREV DISCUSSION...
331 PM PDT WED AUG 1 2012
.SHORT TERM...SO FAR THINGS HAVE NOT BEEN AS ACTIVE THIS AFTERNOON
AS THEY WERE AT THIS POINT YESTERDAY DESPITE AN EXTREMELY MOIST
ATMOSPHERE...PLENTY OF INSTABILITY AND MUCH MORE SUNSHINE. WATER
VAPOR IMAGERY SHOWS THE CENTER OF THE MID/UPPER LEVEL LOW WAS OVER
SOUTHERN CLARK COUNTY AND MOVING SLOWLY NORTHEASTWARD. RADAR SHOWS
AT THE PRESENT MOST OF THE ACTIVITY WAS ABOUT 100 MILES AWAY FROM
THE CENTER OF THE LOW. THE ATMOSPHERE REMAINS EXCEPTIONALLY MOIST
WITH THE 12Z SOUNDING THIS MORNING FROM OUR OFFICE HAVING A PWAT OF
1.82 INCHES. THIS TIED FOR THE SECOND HIGHEST PWAT EVER RECORDED IN
THE SOUNDING CLIMATOLOGY FOR SOUTHERN NEVADA WITH A VALUE BACK IN
AUGUST OF 1984 (THE HIGHEST EVER WAS 1.86 INCHES IN JULY 1966). WITH
SO MUCH MOISTURE PRESENT ANY SHOWER OR THUNDERSTORM THAT GETS GOING
WILL HAVE THE POTENTIAL TO PRODUCE EXTREMELY HEAVY RAIN IN A SHORT
PERIOD OF TIME. THUS THE FLASH FLOOD WATCH OUT WILL REMAIN IN EFFECT.
THE MAIN CHALLENGE FOR THIS EVENING AND THE REST OF TONIGHT WILL BE
JUST HOW ACTIVE THINGS WILL GET. WITH THE MID/UPPER LEVEL LOW
PROGGED TO BE AROUND THROUGH TONIGHT IT WILL BE HARD TO COMPLETELY
SHUT DOWN ALL CONVECTION EXCEPT IN ANY AREAS WHERE THE AIR MASS GETS
WORKED OVER ENOUGH THAT IT BECOMES MUCH MORE STABLE. IF YOU BELIEVE
THE WRF...GFS AND ECMWF CONVECTION SHOULD WIND DOWN AROUND 03Z OR SO
THIS EVENING. ON THE OTHER HAND...THE LOCAL ARW AND NMM MODELS AS
WELL AS THE HRRR MODEL SHOW THE REVERSE WITH THINGS BECOMING MUCH
MORE ACTIVE LATER THIS EVENING. 700 MB STEERING FLOW IS FROM THE
NORTHEAST AND RADAR PRESENTLY SHOWS SHOWERS AND THUNDERSTORMS IN AN
ARCH FROM AROUND ELY TO KANAB. TYPICALLY THIS PATTERN WOULD FAVOR
THIS CONVECTION EVENTUALLY WORKING IN DURING THE LATE EVENING INTO
CLARK COUNTY. IN THE PAST STORMS IN LAS VEGAS ORIGINATING FROM A
NORTHEAST FLOW HAVE USUALLY BEEN RATHER POTENT. THUS...BASED ON A
BLEND OF MODELS WE HAVE KEPT POPS IN THROUGH THE NIGHT FOR MUCH OF
LINCOLN...CLARK...MOHAVE....EASTERN SAN BERNARDINO AND SOUTHERN NYE
COUNTIES. ALTHOUGH FLASH FLOODING REMAINS A THREAT...WE CANNOT RULE
OUT GUSTY WINDS OR HAIL WITH SOME STORMS ESPECIALLY IF THINGS DRY
OUT A LITTLE.
VERY LITTLE CHANGE IN THE OVERALL PATTERN IS EXPECTED FOR THURSDAY
AND FRIDAY. THE MID/UPPER LEVEL LOW IS FORECAST TO GET TRAPPED NEAR
THE TRIPLE POINT OF CALIFORNIA...NEVADA AND ARIZONA AND EVENTUALLY
WEAKEN TO A MORE ILL-DEFINED VORTICITY FEATURE. MEANWHILE HIGH
PRESSURE IN THE MID AND UPPER LEVELS IS FORECAST TO BECOME CENTERED
OVER CENTRAL NEVADA. THIS HIGH WILL KEEP AN EASTERLY MID-LEVEL FLOW
OVER OUR AREA WHICH BY FRIDAY WILL HELP TO PUSH THE VORTICITY
FEATURE TO THE SOUTHWEST AND BY FRIDAY NIGHT PUSH IT OFFSHORE OF
SOCAL. OVER THE NEXT 2 DAYS THE FARTHER NORTHWEST ONE GOES IN THE
CWFA THE LESS OF CHANCE FOR CONVECTION AS THE HIGH ALOFT WILL KEEP
THE ATMOSPHERE MUCH MORE STABLE. FURTHER SOUTH THE COMBINATION OF
THE VORTICITY FEATURE...INSTABILITY AND SUFFICIENT MOISTURE WILL
KEEP THE POTENTIAL FOR THUNDERSTORMS AROUND. WHILE PWATS ARE
FORECAST TO REMAIN OVER AN INCH OVER THE MOJAVE DESERT WHICH WILL
SUPPORT HEAVY RAIN PRODUCING STORMS...WE WILL NOT ISSUE ANY FLASH
FLOOD WATCHES FOR THURSDAY OR FRIDAY AT THIS TIME DUE TO
UNCERTAINTIES IN JUST HOW ACTIVE IT WILL GET. TEMPS SHOULD BE A FEW
DEGREES ABOVE NORMAL BUT MUCH WARMER THAN WHAT WE HAVE SEEN THE PAST
FEW DAYS OVER THE MOJAVE DESERT. WELL ABOVE NORMAL TEMPS WILL
CONTINUE OVER INYO AND ESMERALDA COUNTY.
.LONG TERM...THE OLD VORTICITY FEATURE OFF OF SOCAL GETS CAUGHT UP
IN A BROAD MID/UPPER LEVEL TROUGH OFF THE WEST COAST ON SATURDAY. IT
APPEARS ENOUGH MOISTURE AND INSTABILITY REMAIN AROUND ON SATURDAY
THAT THE POTENTIAL FOR THUNDERSTORMS WILL CONTINUE ESPECIALLY ACROSS
THE NORTHERN HALF OF THE CWFA WHERE THE BEST INSTABILITY LOOKS TO
SET UP. BY SATURDAY NIGHT INTO SUNDAY DRIER AND MORE STABLE AIR IS
SHOWN TO WORK IN FROM THE SOUTH AS THE OFFSHORE TROUGH EDGES CLOSER
TO THE COAST AND MOST OF THE EMBEDDED ENERGY WITHIN THE TROUGH
STARTS TO LIFT ON NORTH. THUS SUNDAY MAY NOT BE QUITE AS ACTIVE FOR
CONVECTION AND POPS SHOW A SLIGHT TREND DOWN THEN. BY MONDAY INTO
NEXT WEDNESDAY THE TROUGH OFFSHORE STILL EXISTS AND RIDGING ALOFT
SITS OVER THE FOUR CORNERS. THIS WOULD FAVOR A SOUTHWEST FLOW ALOFT
ACROSS OUR AREA WHICH WOULD SPREAD DRIER AND STABLE AIR FURTHER EAST
WITH TIME. I DID LOWER POPS AND DEWPOINTS IN THE WESTERN HALF OF THE
AREA TO ACCOUNT FOR THIS HOWEVER MOIST AND UNSTABLE AIR IS SHOWN TO
LINGER OVER MOHAVE COUNTY AND THIS PART OF THE AREA MAY NEVER REALLY
DRY OUT. TEMPS SHOULD RISE BACK CLOSER TO NORMAL IN MOST AREAS AND
MAY EVEN BE A FEW DEGREES ABOVE NORMAL ON MONDAY AND TUESDAY AS
THINGS REALLY DRY OUT. I LEANED CLOSELY TO THE ECMWF MOS AND BIAS
CORRECTED NUMBERS FOR HIGHS.
&&
.VEF WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
AZ...NONE.
CA...NONE.
&&
$$
STACHELSKI
HTTP://WEATHER.GOV/LASVEGAS
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1021 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM SATURDAY MORNING/...
AS OF 1012 PM EDT FRIDAY...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF
SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND
UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN
BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION
BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE
COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S.
ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF
HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH
EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF
WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY
AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS
AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND
ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE
PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE
WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT.
TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH
THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD
COVER.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS
THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR
CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS
AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON
AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY
BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE SOUTHERLY
DIRECTION LATE SATURDAY MORNING INTO AFTERNOON.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN
BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
RELATIVELY LIGHT WINDS EXPECTED FROM THIS EVENING THROUGH THE DAY
SATURDAY. WINDS WILL TURN NORTHERLY FROM 5 TO 15 KNOTS THIS
EVENING...BECOMING LIGHT AND VARIABLE OVERNIGHT...AND THEN 5 TO
15 KNOTS OUT OF THE SOUTH ON SATURDAY. HOWEVER...WINDS WILL
INCREASE SATURDAY NIGHT AND ESPECIALLY ON SUNDAY WITH STRONG
SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED. WAVES WILL BE 1 TO 2
FEET THROUGH SATURDAY...BUILDING TO 2 TO 4 FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...BOYD
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...EVENSON/RJS
MARINE...MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
934 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD.
PREV BLO...
730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA
TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM
ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS.
RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL
POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS
AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND
DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV
BLO...
4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH
TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN
ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY
TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT
FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT
REDUCTION IN VISIBILITY.
WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE
EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS.
OUTLOOK...
SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD-
SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO
MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
733 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
730 AM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA TO
HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM
ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS.
RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL
POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS
AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND
DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV
BLO...
4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH
TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN
ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY
TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT
FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT
REDUCTION IN VISIBILITY.
WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE
EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS.
OUTLOOK...
SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD-
SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO
MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
725 PM EDT FRI AUG 3 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
VFR CONDITIONS UNDER WEAK HIGH PRESSURE WILL CONTINUE THROUGH
TOMORROW AFTERNOON. ONCE AGAIN THERE WILL BE A SMALL CHANCE FOR AN
ISOLATED SHOWER OR THUNDERSTORM, BUT NOT CURRENTLY EXPECTING ANY
TO AFFECT THE TAF SITES. THERE IS ALSO THE CHANCE OF SOME LIGHT
FOG AT KELM, BUT LIKE LAST NIGHT, NOT EXPECTING ANY SIGNIFICANT
REDUCTION IN VISIBILITY.
WINDS WILL BE LIGHT AND VARIABLE INTO TOMORROW MORNING. THEY ARE
EXPECTED TO PICK UP OUT OF THE SOUTH AT AROUND 10KTS.
OUTLOOK...
SAT AFTERNOON THROUGH SUN MORNING...VFR MUCH OF THE TIME. ISOLD-
SCTD LATE AFTN/EARLY EVE TSRA PSBL...WITH BRIEF RESTRICTIONS. ALSO
MVFR VSBYS POSSIBLE SUN AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...HEDEN
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...SLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
345 AM EDT THU AUG 2 2012
.SYNOPSIS...
BUILDING HIGH PRESSURE ALOFT WILL BRING NEAR TO SLIGHTLY ABOVE
NORMAL DAYTIME TEMPERATURES THURSDAY THROUGH THE
WEEKEND...ACCOMPANIED BY ISOLATED THUNDERSTORMS EACH DAY. A WEAK
COLD FRONT WILL REACH THE AREA MONDAY AND MAY LINGER AS IT WEAKENS
SLOWLY THROUGH MID WEEK AS HIGH PRESSURE BUILDS IN BEHIND IT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 AM THURSDAY...MID-LEVEL S/W TROFS OR IMPULSES ACROSS
CENTRAL NC AND UPSTATE GEORGIA...WILL BOTH MAKE A BEE-LINE TO THE SE
U.S. COAST THIS AFTERNOON AND NIGHT. THESE IMPULSES ARE CURRENTLY
RESPONSIBLE FOR THE SMALL CLUSTER OF TSTMS AT THE MOMENT VIA
LATEST AND ADJACENT 88-DS. MAY HAVE TO ADD CONVECTION FOR THIS
MORNING ACROSS THE ILM NC SECTION OF THE CWA GIVEN LATEST
EXTRAPOLATION AND HRRR MODEL OUTPUT. MODELS TAKE THE MID-LEVEL S/W
TROF OFF THE SE NC COAST EARLY THIS EVENING...RESULTING WITH NVA AND
SUBSIDENCE IN ITS WAKE FOR THE REMAINDER OF THU NIGHT. FOR THE TIME
BEING WILL GO WITH 20 TO POSSIBLY 30 POPS TODAY...MAINLY IN THE
VICINITY OF THE MID-LEVEL S/W TROF. FOR THE PAST SEVERAL DAYS IT HAS
BEEN A TUG-OF-WAR BETWEEN NAM MOS AND GFS MOS GUIDANCE FOR THE ILM
CWA. WILL LEAN TOWARD THE NAM MOS GUIDANCE FOR THE TIME BEING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...MID TO UPPER TROUGH LIFTS OFF AND
WEAKENS AS IT GETS SQUEEZED OUT BY RIDGE BUILDING IN OVER THE
SOUTHEAST FROM THE EAST AND WEST. HEIGHTS WILL BE RISING FROM NEAR
588 DM FRI MORNING UP TO 594 DM BY SAT EVENING WITH INCREASED
SUBSIDENCE AND PLENTY OF DRYING THROUGH THE MID LEVELS OF THE
ATMOSPHERE. LOOKS LIKE A VERY TYPICAL SUMMER TIME MOISTURE PROFILE
WITH MOISTURE LOCKED IN BELOW H85 AND RH VALUES DROPPING OFF TO 40
PERCENT OR LESS FROM H7 UP THROUGH H3. PCP WATER VALUES WILL BE
DOWN LESS THAN A HALF INCH AND WILL CREEP UP TO 1.75 BY END OF
PERIOD. MORE OF A W-SW FLOW ON FRI WILL BACK AROUND TO THE S
THROUGH THE LOWER LEVELS AS BERMUDA HIGH BUILDS BACK INTO AREA
FROM THE EAST THROUGH SAT. THIS WILL ALLOW A DEEPER MOISTURE
RETURN BY THE LATTER HALF OF THE WEEKEND. LIGHT SOUTHERLY RETURN
FLOW WILL BE ENHANCED EACH AFTERNOON BY THE SEA BREEZE AS TEMPS
RISE INTO THE 90S WITH PLENTY OF SUNSHINE. THIS SHOULD ALLOW FOR
SOME LOW LEVEL INSTABILITY AND CONVERGENCE ENOUGH TO PRODUCE SOME
CU WITH ONLY SLIGHT CHC OF CONVECTIVE DEVELOPMENT. OVERNIGHT LOWS
WILL FALL INTO THE 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...MID TO UPPER RIDGE WILL BUILD OVER THE
CENTRAL CONUS AS TROUGH PUSHES SYSTEM EAST THROUGH EARLY NEXT
WEEK. A COLD FRONT WILL MAKE IT INTO THE MOUNTAINS BY SUNDAY NIGHT
AND WILL GET PUSHED EAST AS H5 TROUGH DIGS DOWN THROUGH THE
SOUTHEAST ON MONDAY. THEREFORE WILL SEE INCREASED COVERAGE OF
SHWRS/TSTMS ON MONDAY. THIS FRONT MAY GET STALLED AND MAKE SLOW
PROGRESS EAST THROUGH MID WEEK AS IT COMES UP AGAINST STRONG ATLANTIC
RIDGE. IT LOOKS LIKE IT WILL WEAKEN OVER THE AREA MAKING LITTLE
PROGRESS EAST AS WEAK HIGH PRESSURE BUILDS INTO THE CAROLINAS
BEHIND IT. SHOULD KEEP MORE UNSETTLED WEATHER ESPECIALLY ALONG THE
COAST TUES AND WED.
OVERALL SUNDAY SHOULD SEE ONE LAST DAY OF WARMER TEMPS AND
SUNSHINE ON SUNDAY WITH PCP CHC INCREASING SLIGHTLY BUT EXPECT
MUCH MORE IN THE WAY OF CLOUDS AND PCP HEADING INTO MON AND TUES
AND THEREFORE TEMPS SHOULD BE A FEW DEGREES LOWER.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 06Z...PROB OF VCSH AT FLO/LBT BY 08-10Z IS LOW BUT WILL CONT
TO MENTION IN TAFS. BEST CHANCE SHOULD BE AT LBT. VFR CONDITIONS
EXPECTED TO GIVE WAY TO MVFR VSBYS IN BR 08-12Z. LOW CONFIDENCE OF
IFR...BUT IF IFR OCCURS IT MOST LIKELY WOULD OCCUR AT THE COASTAL
TERMINALS. LGT/VRBL WINDS WILL BECOME LIGHT SW AFT SUNRISE. VCSH
VCTS EXPECTED 14-19Z AT THE COASTAL TERMINALS AND AFT 18Z AT
FLO/LBT. WINDS BECOME SOUTHEAST TO SOUTH BY EARLY AFTERNOON. EXPECT
CONVECTION TO DIURNALLY DISSIPATE DURING THE EVENING.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR VSBYS IN BR WITH A CHANCE
OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...BERMUDA HIGH PRESSURE SFC AND ALOFT WILL
RIDGING WESTWARD TO THE SE U.S. COAST THROUGHOUT THE NEAR TERM. A
COUPLE OF MID-LEVEL S/W TROFS WILL MOVE OFF THE MAINLAND THIS NEAR
TERM AND RESULT IN A SOMEWHAT PINCHED SFC PG. WILL BE ADVERTISING SW
WINDS AROUND 15 KT...OR JUST 10-15 KT. AS FOR SIG SEAS...A LOCALLY
PRODUCED 2+ FOOT WIND WAVE COMBINED WITH A 1-2 FT ESE GROUND
SWELL...WILL COMBINE TO PRODUCE SIG SEAS IN THE 2 TO 4 FT RANGE.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH
WILL CONTINUE THROUGH THE PERIOD. WINDS OVERALL WILL BE 10 KTS OR
LESS BUT WILL SEE SOME GUSTINESS WITH SLIGHTLY HIGHER WINDS EACH
AFTERNOON IN SEA BREEZE CLOSER TO SHORE. SEAS WILL REMAIN 2 TO 3
FT WITH A SLIGHTLY LONGER PERIOD EASTERLY SWELL MIXING IN WITH THE
LOCALLY GENERATED WIND WAVE.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SOUTHERLY RETURN FLOW AROUND BERMUDA HIGH
WILL INCREASE SLIGHTLY AS GRADIENT TIGHTENS LATE SUNDAY INTO
MONDAY AS WEAK COLD FRONT MAKES ITS WAY INTO THE CAROLINAS.
THEREFORE EXPECT WINDS TO PICK UP FROM AROUND 10 KTS ON SUNDAY TO
A MORE SOLID 15 KTS THROUGH MONDAY AS FRONT NEARS THE WATERS. WNA
ALSO SHOWING A LONGER PERIOD SE SWELL UP TO 12 SECONDS REACHING
THE WATERS ON MONDAY.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...DCH
SHORT TERM...RGZ
LONG TERM...RGZ
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
958 AM EDT THU AUG 2 2012
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY WEAKEN AS IT SHIFTS TO THE ATLANTIC
COAST. A WEAK COLD FRONT WILL APPROACH THE AREA ON FRIDAY AND
BECOME STATIONARY ACROSS THE LOWER GREAT LAKES. A STRONGER COLD
FRONT WILL SWEEP ACROSS THE REGION BY SUNDAY EVENING.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CURRENT FORECAST IS ON TRACK SO ONLY MINOR CHANGES PLANNED. 12Z
SOUNDINGS SHOW RATHER WARM AIR IN LOW LEVELS WITH 850 MB
TEMPERATURES IN THE RANGE OF +17 TO +19C. ADDITIONAL WARMING IS
EXPECTED TODAY. SO WILL RAISE MAX TEMPERATURES A LITTLE IN THE TOL
TO FDY AREA. THERE STILL IS A QUESTION OF WHETHER OR NOT SOME
CONVECTION MAY DROP SOUTH FROM MICHIGAN AND ONTARIO LATE THIS
AFTERNOON. THE HRRR EVEN DEVELOPS CONVECTION OVER NW PA AND SW NY
BUT FOR NOW WILL KEEP THE FORECAST DRY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
PLENTY OF UNCERTAINTY FOR CONVECTIVE DEVELOPMENT FOR THE SHORT
TERM PERIOD AS WE WATCH FOR OUTFLOW BOUNDARIES TO PUSH A WEAK COLD
FRONT TOWARD LAKE ERIE TONIGHT INTO FRIDAY. IF THESE BOUNDARIES
REMAIN NORTH OF LAKE ERIE IT WILL REMAIN HOT WITH A DECENT CAP
ACROSS THE REGION EVEN AS LOW LEVEL MOISTURE INCREASES. THE
UNCERTAINTY FOR THE WEEKEND WILL BE HOW MUCH CONVECTIVE DEBRIS
WILL OCCUR. THIS MAY HAVE AN IMPACT ON HIGH TEMPERATURES AND THE
AMOUNT OF CAPE AVAILABLE FOR THUNDERSTORMS. THE BEST CHANCES OF
THUNDER WILL BE SATURDAY AFTERNOON INTO SUNDAY. SUNDAY S A BIT
UNCERTAIN WITH BECAUSE OF THE TIMING OF A STRONGER COLD FRONT INTO
NORTHERN OHIO. THE TIMING OF THIS FRONT WILL HAVE SIGNIFICANT
IMPACTS ON SEVERE THUNDERSTORM CHANCES FOR THE COUNTY WARNING AREA.
IT WILL REMAIN HOT INTO THE WEEKEND. AS STATED ABOVE CLOUD COVER
WILL LIKELY BE AN ISSUE FOR HIGHS SATURDAY INTO SUNDAY AND COULD
KEEP THE AREA SLIGHTLY COOLER THAN CURRENT THINKING.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
BEGINNING MONDAY A COLD FRONT WILL PUSH EAST OF THE AREA WITH HIGH
PRESSURE BRINGING DRY WEATHER AND NEAR SEASONABLE TEMPERATURES TO
THE AREA. GFS AND 00Z ECMWF QUIET A BIT DIFFERENT BY LATE IN THE
PERIOD WITH ECMWF QUICKER IN BRINGING NEXT COLD FRONT THROUGH THE
AREA ON WEDNESDAY. GFS SLOWER AND BRINGING FRONT ACROSS LATE NEXT
WEEK. GIVEN RECENT CONDITIONS AND PREVIOUS FORECAST WILL LEAN TOWARD
THE GFS WITH WARMING TEMPS AND THE FRONT NOT PUSHING THROUGH THE
AREA UNTIL LATE WEEK.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
HIGH PRESSURE WILL ALLOW FOR VFR CONDITIONS TO CONTINUE TODAY.
SOME MID AND HIGH CLOUDS WILL SPREAD ACROSS MAINLY NORTHERN SITES
FROM TOL-CLE-ERI TODAY BUT EXPECTING ALL PRECIP TO REMAIN NORTH OF
THE AREA. THE LIGHT GRADIENT WILL ALLOW FOR A LAKE BREEZE AT ERI
AND EVEN CLE LATER IN AFTERNOON.
THE WEAK COLD FRONT WILL MOVE OVER LAKE ERIE TONIGHT BUT WITH THE
EXCEPTION OF ERI WHICH IT WILL BE IN PROXIMITY THE REMAINDER OF
SITES SHOULD REMAIN SOUTH OF THE FRONT. MODELS TRYING AGAIN TO
SHOW SOME WIDESPREAD MVFR VIS DEVELOPING LATE TONIGHT...BUT GIVEN
PAST TRENDS WITH MODELS WILL HOLD OFF ON MENTIONING MVFR FOR NOW.
.OUTLOOK...NON VFR PROBABLE IN SCATTERED THUNDERSTORMS MAINLY
SATURDAY THROUGH SUNDAY.
&&
.MARINE...
HIGH PRESSURE WILL KEEP CONDITIONS ON THE LAKE QUIET TODAY. A COLD
FRONT WILL MOVE SOUTH TOWARD THE LAKE LATE TODAY AND TONIGHT...AND
THE BOUNDARY WILL BECOME STATIONARY NEAR THE LAKE THROUGH FRIDAY AND
PERHAPS EVEN THROUGH SATURDAY WITH SOUTHEAST FLOW. THE FRONT WILL
MOVE BACK NORTH LATER IN THE WEEKEND ALLOW FOR MAINLY SOUTH TO
SOUTHWEST WINDS. LOW PRESSURE IS EXPECTED TO TRACK OVER THE NORTHERN
GREAT LAKES SUNDAY NIGHT AND EARLY MONDAY...AND THE COLD FRONT WITH
THE LOW WILL CROSS THE LAKE. SUNDAY NIGHT THROUGH MONDAY WILL BE THE
NEXT OPPORTUNITY FOR SMALL CRAFT ADVISORY HEADLINES WITH WINDS
SHIFTING NW AND INCREASING TOWARD 20 KNOTS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MULLEN
NEAR TERM...REL
SHORT TERM...MULLEN
LONG TERM...ABE
AVIATION...ABE
MARINE...ABE
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
840 PM CDT FRI AUG 3 2012
.UPDATE...
SEVERAL LARGE WILDFIRES CONTINUE ACROSS PARTS OF THE CWA THIS
EVENING. WINDS EXPECTED TO REMAIN SOUTH AT 10 TO 15 MPH OVERNIGHT
ACROSS MUCH OF THE AREA. AN OUTFLOW BOUNDARY THAT WAS EXTENDED
ACROSS PORTIONS OF NORTHERN OK CONTINUES TO SLOWLY LIFT NORTH.
SHOWERS AND THUNDERSTORMS MOVING ACROSS THE PANHANDLES ARE MOVING
INTO NW PORTIONS OF THE FA THIS EVENING. SHOWERS/STORMS WILL
REMAIN POSSIBLE IN THIS AREA THROUGH THIS EVENING. INCREASED POPS
TO ACCOUNT FOR THE CURRENT ACTIVITY. WILL SEND UPDATES SHORTLY.
MAXWELL
&&
.PREV DISCUSSION... /ISSUED 322 PM CDT FRI AUG 3 2012/
DISCUSSION...
ONGOING CRITICAL FIRE WEATHER CONDITIONS AND RECORD BREAKING
HEAT ARE THE MAIN CONCERNS.
HEAT ADVISORY IS IN GREAT SHAPE AND WILL NOT ALTER.
THROUGH TONIGHT...WINDS WILL STAY UP IN THE 10 TO 15 MPH OVER
MUCH OF THE AREA...THOUGH THE STRONGEST GUSTS SHOULD DIMINISH
BETWEEN 6 AND 9 PM CDT. KEPT 20 PERCENT FOR SHOWERS AND STORMS
OVER NORTHERN OKLAHOMA...MAINLY NORTH OF AN ARNETT TO STILLWATER
LINE WHERE CAP IS WEAKEST. LATEST HRRR INDICATED NEW DEVELOPMENT
THIS EVENING IN FAR NORTHWEST OKLAHOMA. GUSTY WINDS IS THE MAIN
HAZARD WITH ANY STORM DUE TO HIGH CLOUD BASES.
SATURDAY WILL BE ANOTHER VERY HOT DAY...THOUGH MAY BE SLIGHTLY
COOLER DUE TO SLIGHTLY COOLER LOW LEVEL TEMPERATURES. A WEAK
FRONT WILL PUSH INTO NORTHERN OKLAHOMA DURING THE AFTERNOON
AND EVENING HOURS WHICH MAY ALLOW FOR ISOLATED STORM
DEVELOPMENT...SO KEPT 20 PERCENT CHANCES IN THESE AREAS.
SUNDAY THROUGH NEXT FRIDAY...DRY AND HOT CONDITIONS WILL
LIKELY CONTINUE. TEMPERATURES WILL BE COOLER DURING THIS
TIME FRAME...ESPECIALLY ON SUNDAY AS SOME LOCATIONS
MAY NOT REACH 100 DEGREES. CANNOT COMPLETELY RULE OUT
A FEW STORMS SUNDAY AND MONDAY...BUT KEPT A DRY FORECAST
DUE TO LOW CONFIDENCE OF OCCURRENCE.
MBS
FIRE WEATHER...
CURRENT RED FLAG WARNING IS IN GOOD SHAPE AND CONTINUES UNTIL 10
PM CDT. GUSTY SOUTH TO SOUTHWEST WINDS WILL DIMINISH SLIGHTLY
BETWEEN 6 AND 9 PM CDT AND SHIFT MAINLY TO THE SOUTH. LOCATIONS
NORTH OF A WEAK OUTFLOW BOUNDARY FROM PUTNAM TO CHANDLER HAVE A
LOWER CHANCE FOR FIRE IGNITIONS.
UPGRADED THE FIRE WEATHER WATCH TO A RED FLAG WARNING FOR
THE SAME AREAS ON SATURDAY DUE TO VERY SIMILAR FORECAST CONDITIONS.
WINDS MAY BE A NUDGE STRONGER ON SATURDAY COMPARED TO TODAY.
LIGHTER WINDS AND COOLER TEMPERATURES WILL ALLOW FOR
SLIGHTLY LOWER WILDFIRE POTENTIAL SUNDAY INTO NEXT WEEK.
CLIMATE...
OKLAHOMA CITY HAS ALREADY REACHED 112 DEGREES TODAY
SETTING A NEW DAILY RECORD. THE ALL TIME RECORD OF 113
DEGREES MAY BE TIED OR EXCEEDED IN THE NEXT FEW HOURS.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 83 109 74 99 / 0 10 10 10
HOBART OK 79 109 75 99 / 0 0 10 10
WICHITA FALLS TX 79 110 77 105 / 0 0 0 10
GAGE OK 74 100 66 95 / 40 20 30 10
PONCA CITY OK 78 110 69 98 / 10 20 30 10
DURANT OK 78 107 77 102 / 0 0 0 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR OKZ008-012-013-
016>047-050-051.
RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR OKZ008-012-
013-016>047-050-051.
HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR OKZ004>048-050>052.
TX...RED FLAG WARNING UNTIL 10 PM CDT THIS EVENING FOR TXZ083>090.
RED FLAG WARNING FROM 10 AM TO 10 PM CDT SATURDAY FOR TXZ083>090.
HEAT ADVISORY UNTIL 11 PM CDT SATURDAY FOR TXZ083>090.
&&
$$
25/30
AREA FORECAST DISCUSSION
NWS TULSA OK
344 PM CDT THU AUG 2 2012
.DISCUSSION...
ANOTHER OUTFLOW BOUNDARY STRIKES AGAIN. CONVECTION OVER KANSAS
ONCE AGAIN SENT AN OUTFLOW BOUNDARY DOWN INTO OKLAHOMA EARLY THIS
MORNING...AND IT HAS HAD SOME AFFECT ON TEMPS TODAY. BECAUSE OF
THIS...IT DOES NOT APPEAR THAT THE ALL-TIME TEMP RECORD WILL BE
REACHED AT TULSA. THE LATEST RUNS OF THE HRRR SUGGEST SOME
ISOLATED TO WIDELY SCATTERED STORMS COULD DEVELOP ALONG THE EAST-
WEST ORIENTED LOW LVL TROUGH/CONVERGENT ZONE LATE THIS AFTERNOON
AND THIS EVENING. OTHER ELEVATED STORMS COULD DEVELOP ON THE EDGE
OF THE CAP LATE TONIGHT TO OUR EAST.
NAM MODEL 850MB DATA SUGGESTS THAT FRIDAY WILL BE ANOTHER
SCORCHER...WITH HIGHS NEAR 110...ALTHOUGH CONVECTIVE OUTFLOW COULD
AFFECT THIS LIKE IT HAS THE PAST COUPLE OF DAYS. SATURDAY IS
SHAPING UP TO BE HOTTER DUE TO SOME COMPRESSIONAL WARMING AHEAD OF
AN APPROACHING FRONT. SW WINDS WILL BE STRONGER AS WELL...AND THIS
WILL REALLY INCREASE FIRE WEATHER CONCERNS. THE HEAT HEADLINES
WILL CONTINUE ON THROUGH FRIDAY...HOWEVER THIS MAY NEED TO BE
EXTENDED INTO SATURDAY IN LATER FORECASTS. STORMS THAT FORM ALONG
THE FRONT IN KANSAS SATURDAY MAY MAKE THEIR WAY DOWN INTO OKLAHOMA
AND ARKANSAS LATE SATURDAY AND SATURDAY NIGHT. MUCH
COOLER...RELATIVELY SPEAKING...850MB TEMPS...MORE CLOUDS...AND
HIGHER HUMIDITY WILL YIELD HIGHS BELOW 100 DEGREES ON SUNDAY.
TEMPS WARM BACK UP NEXT WEEK INTO THE 100S...HOWEVER IT DOES APPEAR
THAT THE REBUILDING RIDGE AND RESULTING HEAT WILL NOT BE AS
INTENSE THIS GO AROUND. THERE MAY BE ANOTHER WEAK BOUNDARY BY NEXT
THURSDAY OR SO...BUT CONFIDENCE IS NOT HIGH ENOUGH TO INSERT POPS
JUST YET.
LACY
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 85 110 86 108 / 10 20 10 20
FSM 79 105 79 102 / 20 20 10 20
MLC 79 107 81 105 / 10 10 10 10
BVO 74 108 76 108 / 20 20 20 30
FYV 76 104 77 100 / 30 20 10 20
BYV 75 101 76 101 / 30 30 20 20
MKO 80 109 80 107 / 10 20 10 20
MIO 77 104 79 104 / 30 20 20 30
F10 80 112 79 107 / 10 10 10 10
HHW 78 104 78 99 / 10 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR OKZ054-OKZ055-
OKZ056-OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-
OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071-
OKZ072-OKZ073-OKZ074.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR OKZ049-OKZ053-OKZ075-OKZ076.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM FRIDAY FOR ARZ001-ARZ010-
ARZ019-ARZ029.
HEAT ADVISORY UNTIL 7 PM FRIDAY FOR ARZ002-ARZ011-ARZ020.
&&
$$
LONG TERM....30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
352 PM EDT THU AUG 2 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A
SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING
WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY.
THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER
PART OF SUNDAY INTO EARLY MONDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR
CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS
POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER
3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON
THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT
EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED
DOWNPOUR.
AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE
OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG
FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL
AVERAGE SEVERAL DEG ABOVE NORMAL.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL
PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST
AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN
MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL
CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER
18Z...BUT AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW.
HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS
STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES
TO TOP 100...BUT IT WILL BE CLOSE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
NOT A LOT OF CHANGE FROM RECENT DAYS.
MAIN THING WAS TO UP TEMPS SOME ON MANY OF THE PERIODS...EVEN
WITH THE RAINFALL...MAX TEMPS LIKELY TO BE WARMER THAN FCST.
GFS HAS CLOSE TO A 579 THICKNESS ACROSS SE PA SUNDAY AFT.
ALSO GUIDANCE MIN TEMPS BEEN TOO COLD LATELY...BFD LAST
NIGHT WAS AN EXAMPLE OF THIS.
SOME CHC FOR A SHOWER OR TSRA ACROSS THE AREA FRIDAY NIGHT...
AND AGAIN LATER SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH
GRADUALLY RETURNS NORTH AS A WARM FRONT...AND THE FAVORABLE
LEFT EXIT REGION OF AN UPPER JET HEADS SE FROM THE GLAKES
REGION.
BEST CHC FOR SEVERE SUNDAY WILL BE NORTH CENTRAL PA AND THE
SUSQUEHANNA VLY. NORTHERN PA WILL BE NEAR THE SOUTHERN EDGE
OF THE BETTER DYANMICS. ACROSS EASTERN PA...THE LEE TROUGH
WILL LIKELY TO FORM IN EASTERN PA...AIDING THE FORMATION OF
STORMS SUNDAY AFTERNOON AND EVENING.
I DID SLOW TIMING OF FRONT DOWN SOME...THUS A LITTLE MORE
CLDS AND THREAT OF SHOWERS AND STORMS INTO MONDAY ACROSS
S PA.
NOT SEEING MUCH OF A COOL DOWN FOR NEXT WEEK...TEMPS NEAR
OR JUST ABOVE NORMAL.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE
OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP
NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS
VERY ISOLATED SO PROBABILITIES WILL BE LOW.
OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH
SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID
IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER
SUN.
ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED
POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH
SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER.
OUTLOOK...
.FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY
CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF
SUNDAY
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 PM EDT THU AUG 2 2012
.SYNOPSIS...
WEAK HIGH PRESSURE WILL DOMINATE THE WEATHER THROUGH FRIDAY. A
SOUTHWEST FLOW OF MORE HUMID AIR WILL DEVELOP FOR THE UPCOMING
WEEKEND. A COLD FRONT WILL MOVE IN LATE SUNDAY OR EARLY MONDAY.
THERE WILL BE A CHANCE OF SHOWERS OR STORMS...MAINLY THE LATER
PART OF SUNDAY INTO EARLY MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LOW CLOUDS BURNED OFF NICELY ALLOWING US TO HEAT RAPIDLY TO OUR
CONVECTIVE TEMP. AT THIS HOUR WE EVEN HAVE A FEW ISOLATED STORMS
POPPING OFF OVER MY SERN ZONES WHERE RAP CAPES ARE ANALYZED OVER
3000J AND DEWPOINTS REMAIN NEAR 70 DEG. THE STORMS ARE FORMING ON
THE BACK EDGE OF THE DEEPEST MOISTURE AND MOVING EAST...SO NOT
EXPECTED TO AFFECT MORE THAN A FEW COUNTIES WITH LOCALIZED
DOWNPOUR.
AFTER THE SPOTTY CONVECTION DIES WITH THE LOSS OF HEATING...THE
OVERNIGHT TONIGHT WILL ONCE AGAIN BE FAIR WITH SOME PATCHY FOG
FORMING AROUND OR AFTER MIDNIGHT. LOWS IN THE 50S AND 60S WILL
AVERAGE SEVERAL DEG ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY/...
DRY WEATHER AND GENERALLY PTLY CLOUDY SKIES WITH LIGHT WIND WILL
PERSIST THROUGH MOST OR ALL OF THIS PERIOD. THE NEARLY EAST/WEST
AXIS OF STEEP MID LEVEL LAPSE RATES WILL STRETCH ACROSS THE NRN
MTNS OF PENN FRIDAY AFTERNOON/EVENING. WEAK LLVL
CONVERGENCE/OROGRAPHIC LIFT COULD SPARK A FEW TSRA AFTER 18Z...BUT
AREAL COVERAGE IS ANTICIPATED TO BE QUITE LOW.
HIGHS FRIDAY WILL TOP 90 OVER A GOOD DEAL OF THE AREA. AT THIS
STAGE THE DEWPOINTS ARE JUST LOW ENOUGH TO NOT ALLOW HEAT INDICES
TO TOP 100...BUT IT WILL BE CLOSE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
SOME CHC FOR A SHOWER OR TSRA ACROSS THE ENTIRE AREA FRIDAY NIGHT
INTO SATURDAY NIGHT AS THE BOUNDARY TO OUR SOUTH GRADUALLY RETURNS
NORTH AS A WARM FRONT...AND THE FAVORABLE LEFT EXIT REGION OF AN
UPPER JET HEADS SE FROM THE GLAKES REGION.
THERE/S A BETTER CHC FOR MORE WIDESPREAD AND STRONGER CONVECTION
SATURDAY AFTERNOON AND EVENING...ESPECIALLY ACROSS THE WRN HALF OF
PENN WHERE THE LATEST SREF PAINTS SFC-BASED CAPES OF 1500-1800 J/KG
COINCIDING WITH A BELT OF ANOMALOUSLY STG SOUTHERLY 850 MB WINDS OF
PLUS 2-3 ST DEVIATIONS. THIS SRLY LL JET PEAKS AROUND 30 KTS AT 03Z
SUNDAY BEFORE LIFTING NORTH INTO NEW YORK STATE LATER SUNDAY
MORNING. A SHARP INCREASE IN LLVL MOISTURE/PRECIPITABLE WATER WILL
OCCUR LATE FRIDAY NIGHT THROUGH SATURDAY. PWATS WILL AVERAGE 1.5-2
INCHES ACROSS THE STATE SATURDAY AFTERNOON AND EVENING. THE
ASSOCIATED 850 MB MOISTURE FLUX WILL ALSO DISPLAY A STRONG SIGNAL
FOR POTENTIALLY SEVERE TSRA AS IT REACHES 2-3 ST DEVIATIONS ABOVE
NORMAL ACROSS ALL OF THE FCST AREA AT 00Z SUNDAY.
SUNDAY AFTERNOON AND EVENING WILL LIKELY BRING ANOTHER BOUT OF
SCTD-NUMEROUS SHOWERS/TSRA...SOME POTENTIALLY SVR AS A STRONG COLD
FRONT PLOWS EAST FROM THE OHIO VALLEY.
THE CORE OF STRONGER AND SLIGHTLY LESS ANOMALOUS...925-850 MB WINDS
SHIFTS TO OUR FAR EASTERN ZONES AND TURNS MORE TO A SWRLY
DIRECTION DURING THE DAY SUNDAY .
SFC TEMP/DEWPOINT SPREADS ARE PROGGED TO BE APPRECIABLY LOWER
SUNDAY...POSSIBLY DUE TO SOME EARLY MORNING CONVECTION/MCS REMNANTS
AND LINGERING MORNING/MIDDAY CLOUD COVER. IN ANY CASE...THE TARGET
AREA FOR THE GREATEST CONCENTRATION OF TSRA WILL SHIFT TO THE
CENTRAL MTNS AND SUSQ VALLEY SUNDAY AFTERNOON AND EVENING...WHERE
THE 0-1KM ENERGY/HELICITY INDEX WILL CLIMB TO AROUND 2-2.5
M2/S2.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
ALL SITES HAVE IMPROVED TO VFR AND WILL REMAIN THAT WAY INTO THE
OVERNIGHT. ONLY POSSIBLE COMPLICATION IS IF A STRAY STORM POPS UP
NEAR OUR SERN TERMINALS FOR THE NEXT FEW HOURS. THE ACTIVITY IS
VERY ISOLATED SO PROBABILITIES WILL BE LOW.
OVERNIGHT WILL ONCE AGAIN FEATURE PATCHY FOG AND LOW CLOUDS WITH
SOME MVFR/IFR POSSIBLE...ESPECIALLY AROUND SUNRISE. EXPECT RAPID
IMPROVEMENT TO VFR BY MID MORNING FRIDAY UNDER THE STRONG SUMMER
SUN.
ONLY CONCERN FOR FRIDAY WILL BE THE POTENTIAL FOR MORE ISOLATED
POP UP DIURNAL CONVECTION. NO REAL WEATHER FEATURE PASSING THROUGH
SO IT WILL BE BASICALLY DAY TIME HEATING AS A TRIGGER.
OUTLOOK...
.FRI-SUN...MAINLY VFR...BUT WITH DIURNAL CONVECTION POSSIBLY
CAUSING LOCALIZED REDUCED CONDITIONS...MAINLY THE LATER HALF OF
SUNDAY
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
803 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
0000 UTC UPDATE...POPS WERE LOWERED IN THE CENTRAL NC MOUNTAINS
WHERE A GAP ION COVERAGE HAS APPEARED. QPF WAS LOWERED IN THE SC
FOOTHILLS...AND RAISED IN THE CHARLOTTE AREA.
PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE
SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN
THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING
SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN.
THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS
THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND
LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS
EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN
WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP
CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED
AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE
AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING.
THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO
DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE.
OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST
ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD.
DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE
GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING.
PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT
EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT
WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY
HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS
POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS
MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN
UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE
IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE
AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY
JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE
REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN
SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND...
THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH
A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH
THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE
GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS
FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE
MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE
WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE
TO CLIMO.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AT KCLT...CONVECTIVE ACTIVITY IS EXPECTED TO CONTINUE NEAR THE FIELD
FOR SEVERAL HOURS THIS EVENING AS A MID LEVEL SYSTEM CROSSES THE
EAST COAST...POSSIBLY ACCOMPANIED BY MVFR CIG AND VSBY. OTHERWISE...
LOW VFR CIGS ARE EXPECTED UNTIL EARLY MORNING...WHEN GUIDANCE
SUGGEST IFR CIGS IN A MOIST BOUNDARY LAYER. GUIDANCE CIG HEIGHTS
WERE RAISED ABOUT 500 FEET FOR CONTINUITY WITH CIGS FROM THIS
MORNING...AS CONFIDENCE IS LIMITED IN THE LOW END IFR MODEL CIG.
THIS LEAVES KCLT WITH A LOW END MVFR CIG AROUND DAYBREAK. MODEL VSBY
WAS MVFR...BUT THE MODELS HAVE BEEN TOO LOW WITH VSBY...AND VFR WILL
BE CARRIED FOR NOW. CONVECTIVE CHANCES FOR SATURDAY AFTERNOON ARE
HIGH ENOUGH TO CARRY A PROB30. SOUTHERLY WINDS WILL PREVAIL.
ELSEWHERE...MOUNTAIN CONVECTION IS EXPECTED TO DEVELOP ACROSS THE
MOUNTAINS AND INTO THE FOOTHILLS THIS EVENING...AND MVFR CIG AND
VSBY RESTRICTIONS WILL BE POSSIBLE. AFTERWORDS...LOW VFR CIGS CAN BE
EXPECTED INTERMITTENTLY UNTIL SEVERAL HOURS BEFORE DAWN. AT THAT
POINT MODEL GUIDANCE IS QUITE DIRE WITH CIG HEIGHTS...BUT WITH LOW
CONFIDENCE IS SUCH LOW CIGS...A GENERAL IFR WILL BE CARRIED...EXCEPT
VFR AT KAND. GUIDANCE FAVORS MVFR VSBY EAST OF THE MOUNTAINS...AND
LIFR IN THE MOUNTAIN. BASED ON TRENDS FROM YESTERDAY AND LIMITED
CONFIDENCE...IFR WILL BE CARRIED IN THE MOUNTAINS...MVFR ALONG
INTERSTATE 40...AND VFR TO THE SOUTH. SATURDAY AFTERNOON CONVECTIVE
CHANCES WARRANT PROB30 AT ALL LOCATIONS. WINDS WILL GENERALLY BE
FROM THE S OR SE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...JAT/MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...JAT
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
718 PM EDT FRI AUG 3 2012
.SYNOPSIS...
CIRCULATION AROUND HIGH PRESSURE CENTERED OVER THE WESTERN ATLANTIC
WILL KEEP THE SOUTHERN APPALACHIAN REGION WARM AND HUMID THROUGH THE
WEEKEND. A COLD FRONT IS EXPECTED TO SLOWLY SWEEP ACROSS THE WESTERN
CAROLINAS AND NORTHEAST GEORGIA EARLY NEXT WEEK...POSSIBLY BECOMING
STATIONARY AND LINGERING INTO LATE IN THE WORK WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
2330 UTC UPDATE...POPS WERE RAISED ALONG INTERSTATE 85 IN NC PER
RADAR TRENDS. QPF WAS LOWERED IN THE FOOTHILLS. SKY COVER WAS
UPDATED FORM THE LATEST VISIBLE IMAGERY. WINDS WERE UPDATED WITH A
BLEND OF THE 18Z ADJMAV AND 18Z NAM.
PREVIOUS DISCUSSION...CONVECTION HAS BEGUN TO DEVELOP OVER THE
SOUTHWEST AND CENTRAL NC MTNS. LAYER RH VALUES ARE THE HIGHEST IN
THIS PART OF THE FORECAST AREA...AND IT/S CLOSET TO THE APPROACHING
SHORTWAVE TROUGH WHICH CURRENTLY EXTENDS FROM CENTRAL KY TO ERN TN.
THE FEATURE ITSELF IS QUITE WEAK AND THE EFFECTIVE BULK SHEAR ACROSS
THE REGION IS WELL UNDER 20 KTS. THEREFORE DIFFERENTIAL HEATING AND
LLVL MASS CONVERGENCE SHOULD BE THE MAIN DRIVERS FOR CONVECTION THIS
EVENING. THE LATEST HI-RES NUMERICAL MODEL RUNS ARE MORE VARIED THAN
WHAT I SAW THIS MORNING. THE WRF-ARW AND THE HRRR BOTH DEVELOP
CONVECTION OVER PARTS OF THE FA...BUT IT/S NOT LOOKING AS ORGANIZED
AS EARLIER. THE 12 UTC 4KM SPC WRF ON THE OTHER HAND HAS A LARGE
AREA OF CONVECTION OVER THE WESTERN UPSTATE AND NE GA THIS EVENING.
THE 12 UTC NAM HAS STRONG LLVL CONVERGENCE THIS EVENING AND ALSO
DEVELOPS INTENSE SLOW MOVING CONVECTION OVER THE UPSTATE.
OVERALL...THE IDEA OF LIKELY POPS SLOWLY SPREADING FROM WEST TO EAST
ACROSS THE FA THE REST OF THE AFN AND EVENING STILL LOOKS GOOD.
DCAPE VALUES ARE WELL OVER 1000 J/KG ACROSS THE UPSTATE AND NE
GA...AND PULSE SEVERE STORMS ARE A GOOD BET AGAIN THIS EVENING.
PULSE SEVERE WON/T BE LIKELY OVER THE NC MTNS AND FOOTHILLS...BUT
EVEN THOUGH CURRENT DCAPE VALUES AREN/T THAT GREAT...I STILL SUSPECT
WE/LL SEE A FEW SEVERE STORMS ALONG THE I-77 URBAN CORRIDOR. VERY
HEAVY RAIN IS ALSO POSSIBLE IS SPOTS AND ISOLATED FLASH FLOODING IS
POSSIBLE. LATER TONIGHT WIDESPREAD LOW CLOUDS SHOULD DEVELOP ACROSS
MOST OF THE FA.
ON SATURDAY THE UPPER TROUGH WEAKENS QUICKLY AS THE ATLANTIC RIDGE
STARTS TO BUILD BACK INTO THE REGION. THE WEAKENING OF THE TROUGH IS
A LITTLE FASTER THAN WHAT WE/D BEEN EXPECTING. LAYER RH/S WILL
REMAIN HIGH AND EVEN WITH VERY WEAK FORCING...THERE SHOULD BE PLENTY
OF CONVECTION OVER THE HIGH TERRAIN AND A LITTLE LESS OUT ACROSS THE
FOOTHILLS AND PIEDMONT. THE SEVERE AND FLOODING RISK DON/T LOOK AS
GREAT TOMORROW. INTERESTINGLY...THE STRONGEST FORCING OF THE DAY
COULD COME IN THE FORM OF THE SEA-BREEZE FRONT WHICH THE NAM BRINGS
INTO THE SE ZONES EARLY IN THE EVENING.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 145 PM EDT...EXPECT SOME ONGOING SCATTERED CONVECTION SATURDAY
EVENING TO WANE RATHER QUICKLY AS SUBTROPICAL RIDGE BUILDS WESTWARD
INTO THE AREA SAT NIGHT. HENCE...THE SAT OVERNIGHT THROUGH SUNDAY
MORNING IS EXPECTED TO BE TRANQUIL. ON SUNDAY AFTERNOON...UPSLOPE
FLOW AND THE APPROACH OF A WEAK COLD FRONT FROM THE NW SHOULD
TRIGGER SCATTERED TO NUMEROUS SHOWERS/THUNDERSTORMS ACROSS THE
MOUNTAINS. ONLY ISOLATED TO WIDELY SCATTERED ACTIVITY IS EXPECTED
ELSEWHERE. THE MODELS BRING THE FRONTAL BOUNDARY INTO THE MOUNTAINS
SUNDAY NIGHT WHICH NECESSITATES MAINTAINING AT LEAST SCATTERED POPS
THERE. ON MONDAY...THE FRONT IS FORECAST TO LAY OUT ACROSS THE
WESTERN CAROLINAS INTO NE GA WHICH SHOULD BE A FOCAL POINT FOR
SCATTERED TO NUMEROUS SHOWERS AND THUNDERSTORMS. MAXIMUM
TEMPERATURES ARE EXPECTED TO BE NEAR CLIMO WITH MIN TEMPERATURES
ABOUT A CATEGORY ABOVE AVERAGE.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1 PM EDT FRIDAY...THE MEDIUM RANGE IS EXPECTED TO FEATURE
SOME DEGREE OF BROAD UPPER TROFFING OVER THE EASTERN U.S. WITH
PERHAPS SOME AMPLIFICATION IN THE TROUGH TOWARD THE END OF THE
PERIOD. THE PERSISTENT TROUGH AND THE PRESENCE OF THE FRONT WILL
CONTINUE TO TRIGGER SHOWERS AND THUNDERSTORMS THROUGH TUE...WITH AN
UPTICK DURING THE FAVORED AFTERNOON AND EVENING TIME PERIOD. THERE
IS SOME DIVERGENCE IN THE GUIDANCE IN REGARD TO HOW FAR SOUTH THE
AFOREMENTIONED FRONT GOES. THE ECM CAMP TAKES THE FRONTAL BOUNDARY
JUST SOUTH OF THE AREA ON WED AND BRINGS SOMEWHAT DRYER INTO THE
REGION FOR WED INTO THU. THIS WOULD PRODUCE A DECREASE IN
SHOWER/THUNDERSTORM ACTIVITY FOR WED INTO THU. ON THE OTHER HAND...
THE GFS HANGS UP THE BOUNDARY OVER THE AREA THROUGH THE PERIOD WITH
A CONTINUATION OF ENHANCED SHOWER AND THUDNERSTORM ACTIVITY THROUGH
THE END OF THE WEEK. HPC SIDED WITH THE ECM FRONTAL POSITION. WE
GENERALLY STAYED CLOSE TO HPC GUIDANCE WITH HIGHER THAN CLIMO POPS
FOR TUE AND THEN SOMEWHAT LOWER THAN CLIMO...ESPECIALLY ACROSS THE
MOUNTAINS FOR WED. BASICALLY CLIMO POPS RETURN FOR THE END OF THE
WEEK. USED A BLEND OF HPC/GMOS FOR TEMPS WHICH ESSENTIALLY IS CLOSE
TO CLIMO.
&&
.AVIATION /23Z FRIDAY THROUGH WEDNESDAY/...
AT KCLT...CONVECTIVE ACTIVITY IS EXPECTED TO CONTINUE NEAR THE FIELD
FOR SEVERAL HOURS THIS EVENING AS A MID LEVEL SYSTEM CROSSES THE
EAST COAST...POSSIBLY ACCOMPANIED BY MVFR CIG AND VSBY. OTHERWISE...
LOW VFR CIGS ARE EXPECTED UNTIL EARLY MORNING...WHEN GUIDANCE
SUGGEST IFR CIGS IN A MOIST BOUNDARY LAYER. GUIDANCE CIG HEIGHTS
WERE RAISED ABOUT 500 FEET FOR CONTINUITY WITH CIGS FROM THIS
MORNING...AS CONFIDENCE IS LIMITED IN THE LOW END IFR MODEL CIG.
THIS LEAVES KCLT WITH A LOW END MVFR CIG AROUND DAYBREAK. MODEL VSBY
WAS MVFR...BUT THE MODELS HAVE BEEN TOO LOW WITH VSBY...AND VFR WILL
BE CARRIED FOR NOW. CONVECTIVE CHANCES FOR SATURDAY AFTERNOON ARE
HIGH ENOUGH TO CARRY A PROB30. SOUTHERLY WINDS WILL PREVAIL.
ELSEWHERE...MOUNTAIN CONVECTION IS EXPECTED TO DEVELOP ACROSS THE
MOUNTAINS AND INTO THE FOOTHILLS THIS EVENING...AND MVFR CIG AND
VSBY RESTRICTIONS WILL BE POSSIBLE. AFTERWORDS...LOW VFR CIGS CAN BE
EXPECTED INTERMITTENTLY UNTIL SEVERAL HOURS BEFORE DAWN. AT THAT
POINT MODEL GUIDANCE IS QUITE DIRE WITH CIG HEIGHTS...BUT WITH LOW
CONFIDENCE IS SUCH LOW CIGS...A GENERAL IFR WILL BE CARRIED...EXCEPT
VFR AT KAND. GUIDANCE FAVORS MVFR VSBY EAST OF THE MOUNTAINS...AND
LIFR IN THE MOUNTAIN. BASED ON TRENDS FROM YESTERDAY AND LIMITED
CONFIDENCE...IFR WILL BE CARRIED IN THE MOUNTAINS...MVFR ALONG
INTERSTATE 40...AND VFR TO THE SOUTH. SATURDAY AFTERNOON CONVECTIVE
CHANCES WARRANT PROB30 AT ALL LOCATIONS. WINDS WILL GENERALLY BE
FROM THE S OR SE.
OUTLOOK...ISO/SCT AFTN-EVE TSTMS ACROSS THE AREA EACH DAY. MTN VLYS
WILL SEE BEST CHANCE OF MORNING LOW CLOUDS/FOG.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...NED
NEAR TERM...JAT/MCAVOY
SHORT TERM...LG
LONG TERM...LG
AVIATION...JAT
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
819 PM MDT FRI AUG 3 2012
.UPDATE...THE SHOWERS MOVING THROUGH NORTHEAST WYOMING HAVE BECOME
SLIGHTLY MORE INTENSE DURING THE PAST COUPLE OF HOURS...BUT
LIGHTNING IS STILL VERY SPARSE. MEANWHILE THE POSSIBILITY OF
CONVECTION DEVELOPING NORTH OF THE FRONT IN NORTH CENTRAL NEBRASKA
MENTIONED IN THE PREVIOUS UPDATE HAS NOT OCCURRED. THE 00Z KUNR
SOUNDING SHOWS A VERY STRONG POST FRONTAL SUBSIDENCE INVERSION
WHICH WOULD PRECLUDE ANY SIGNIFICANT DEVELOPMENT.
&&
.PREV DISCUSSION... /ISSUED 536 PM MDT FRI AUG 3 2012/
UPDATE...KEEPING AN EYE ON THE CONVECTIONS ALONG THE COLD FRONT
IN NORTH CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR SHOWS SOME OF
THIS DEVELOPING NORTHWARD ACROSS THE SOUTH DAKOTA BORDER LATER
THIS EVENING WHEN A STRONG VORTICITY LOBE ROTATES AROUND THE MAIN
UPPER LOW THROUGH SOUTH CENTRAL SOUTH DAKOTA.
AVIATION...00Z TAFS
AN AREA OF SCT SHRA IS MOVING INTO NORTHEASTERN WYOMING THIS
AFTERNOON. CIGS AND VSBYS HAVE NOT BEEN BELOW MVFR IN THE
PRECIP...BUT SOMEWHAT LOWER CONDITIONS COULD DEVELOP AS IT MOVES
INTO NORTHERN CAMPBELL COUNTY WITH THE UPSLOPE SURFACE FLOW.
ELSEWHERE THE STRONGEST AFTERNOON CONVECTION IS CONFINED TO
EASTERN PARTS OF SOUTH DAKOTA AND NROTH CENTRAL NEBRASKA. MVFR
CONDITIONS POSSIBLE IN HEAVIER STORMS. OTHERWISE...VFR CONDITIONS
WILL PREVAIL THROUGH THE EVENING. GUSTY NORTHWEST WINDS TO 35 KTS
WILL CONTINUE TO GRADUALLY SUBSIDE DURING THE EVENING HOURS.
GUSTY NORTHWEST WINDS ARE EXPECTED AGAIN SATURDAY.
PREV DISCUSSION... /ISSUED 253 PM MDT FRI AUG 3 2012/
DISCUSSION...UPPER LEVEL ANALYSIS HAS LOW PRESSURE OVER FAR
SOUTHWESTERN SK MOVING SLOWLY EASTWARD...WITH SOUTHWESTERLY FLOW
AHEAD OF IT ACROSS THE NORTHERN PLAINS. CURRENT SURFACE ANALYSIS
SHOWS COLD FRONT STRETCHING FROM NORTHEASTERN ND THROUGH CENTRAL SD
AND INTO THE NEBRASKA PANHANDLE. TIGHTENING PRESSURE GRADIENT
BEHIND THE FRONT IS PRODUCING GUSTY NORTH TO NORTHWEST WINDS
ACROSS MUCH OF THE WESTERN SD PLAINS. THE STRONGEST WINDS ARE IN
THE RAPID CITY AREA...WHERE A FEW GUSTS TO AROUND 50 MPH HAVE BEEN
NOTED. SKIES RANGE FROM MOSTLY CLOUDY ACROSS FAR NORTHEASTERN WY
AND NORTHWESTERN SD TO MOSTLY SUNNY ACROSS SOUTHERN SD. MAIN BAND
OF SHOWERS AND THUNDERSTORMS IS STAYING NORTH OF THE CWA SO
FAR...CLOSER TO THE UPPER LOW. THUNDERSTORMS HAVE ALSO DEVELOPED
ALONG THE FRONT FROM CENTRAL ND INTO NORTH CENTRAL SD. TEMPS
CURRENTLY RANGE FROM THE UPPER 60S ACROSS PORTIONS OF
NORTHEASTERN WY AND NORTHWESTERN SD...TO THE 90S OVER SOUTH
CENTRAL SD.
COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL SD LATE THIS
AFTERNOON AND INTO EASTERN SD THIS EVENING. UPPER LOW WILL TRACK
EAST ACROSS FAR SOUTHERN SK THROUGH TONIGHT. GUSTY WINDS WILL
CONTINUE THROUGH THE LATE AFTERNOON AND THEN GRADUALLY DECREASE
THIS EVENING. THE BEST CHANCES FOR SHOWERS AND STORMS WILL BE
ALONG THE FRONT ACROSS CENTRAL SD LATE THIS AFTERNOON INTO
TONIGHT. SUFFICIENT INSTABILITY AND SHEAR REMAINS ALONG AND AHEAD
OF THE FRONT ACROSS FAR SOUTH CENTRAL SD TO ALLOW FOR A THREAT OF
A SEVERE THUNDERSTORM OR TWO OVER THE NEXT HOUR OR TWO.
HOWEVER...THE BETTER THREAT FOR SEVERE STORMS WILL CLEARLY BE
ACROSS EASTERN SD THROUGH THIS EVENING. STRONG WIND GUSTS WOULD BE
THE MAIN THREAT FROM ANY SEVERE STORMS...BUT LARGE HAIL IS ALSO A
POSSIBILITY. A FEW SHOWERS AND STORMS ARE ALSO POSSIBLE OVER
NORTHEASTERN WY AND SOUTHWESTERN SD LATE THIS AFTERNOON INTO THIS
EVENING AS WEAK SHORTWAVE ENERGY CROSSES ON THE SOUTHERN SIDE OF
THE TROF AND INTERACTS WITH WEAK INSTABILITY REMAINING OVER THE
AREA. THE POSSIBILITY FOR SHOWER COULD LINGER ACROSS SOUTH
CENTRAL SD OVERNIGHT AS THE BACK END OF THE WAVE CROSSES. TEMPS
WILL BE PLEASANTLY COOL IN MOST AREAS OVERNIGHT...WITH LOWS
MOSTLY IN THE 50S...SOME 40S OVER THE BLACK HILLS AND NORTHEASTERN
WY.
THE WEEKEND LOOKS TO BE VERY NICE WITH MOSTLY CLEAR SKIES
EXPECTED. TEMPS WILL BE PLEASANTLY COOL ON SATURDAY...WITH HIGHS
IN THE 70S AND LOWER 80S AS CANADIAN HIGH PRESSURE MOVES INTO THE
AREA LATE IN THE DAY. BREEZY NORTHWESTERLY WINDS CAN BE EXPECTED
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS THE
PLAINS BEFORE THE HIGH BUILDS IN. LIGHT WINDS...CLEAR SKIES...AND
DRY AIR WILL ALLOW FOR GOOD RADIATIONAL COOLING SATURDAY
NIGHT...WITH LOWS IN THE MID 40S TO MID 50S AT MOST LOCATIONS. AS
THE HIGH MOVES EAST OF THE REGION LATE SATURDAY NIGHT/EARLY
SUNDAY AND RIDGING BUILDS OVER THE ROCKIES...WARMER AIR WILL BEGIN
TO ADVECT BACK INTO THE AREA. SOUTH TO SOUTHEAST WINDS WILL DEVELOP
ON SUNDAY WITH TEMPS RISING TO THE UPPER 80S TO MID 90S ON THE
PLAINS...80S ACROSS THE BLACK HILLS.
EXTENDED...RESURGENCE OF THE CENTRAL/WESTERN NOAM RIDGE EXPECTED IN
THE PERIOD...WITH THE REGION REMAINING ON THE EDGE OF FAST DISTURBED
UPPER LEVEL FLOW. SEMI-PERMANENT NE PAC UPPER TROUGH WILL TEND TO
SUPPORT FAST FLOW ALOFT NEARBY WITH PERIODIC SUBTLE SHORTWAVE
IMPULSES EXPECTED IN THE FLOW SUPPORTING SOME TS CHANCES IN THE
PERIOD...PRIMARILY TUES THROUGH THUR ATTM. OVERALL RAIN CHANCES DO
REMAIN BLEAK GIVEN LACK OF DEEP MOISTURE...WITH VERY LIMITED
COVERAGE OF ANY STORMS THAT DO MATERIALIZE. WAVE TIMING STILL TO BE
RESOLVED TO FURTHER DELINEATE AREAL/TIMING DETAIL. THUS RETAINED POP
VALUES VERY CLOSE TO PREVIOUS FORECAST NUMBERS...RETAINING
CONSISTENCY. H7 GEFS TEMP ANOMALIES SUGGEST 1-2 STD DEVIATIONS ABOVE
CLIMO THROUGH MUCH OF THE PERIOD...ESP TUE ON...THUS A TREND TO THE
HIGH SIDE OF GUIDANCE WAS WARRANTED PER HIGHS. REMOVAL OF DEEP
MOISTURE WITH OVERALL LIGHT OVERNIGHT FLOW IN MANY PERIODS SUGGEST
DECENT RADIATIONAL COOLING...WITH PREFERENCE TOWARD MID GUIDANCE
NUMBERS PER LOWS. OVERALL...EXPECT ABOVE NORMAL TEMPS TO CONTINUE
IN THE PERIOD...WITH NORMAL TO BELOW NORMAL CHANCES FOR PRECIP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM....WFO UNR
AVIATION...CARPENTER
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
536 PM MDT FRI AUG 3 2012
.UPDATE...KEEPING AN EYE ON THE CONVECTIONS ALONG THE COLD FRONT
IN NORTH CENTRAL NEBRASKA THIS AFTERNOON. THE HRRR SHOWS SOME OF
THIS DEVELOPING NORTHWARD ACROSS THE SOUTH DAKOTA BORDER LATER
THIS EVENING WHEN A STRONG VORTICITY LOBE ROTATES AROUND THE MAIN
UPPER LOW THROUGH SOUTH CENTRAL SOUTH DAKOTA.
&&
AVIATION...00Z TAFS
AN AREA OF SCT SHRA IS MOVING INTO NORTHEASTERN WYOMING THIS
AFTERNOON. CIGS AND VSBYS HAVE NOT BEEN BELOW MVFR IN THE
PRECIP...BUT SOMEWHAT LOWER CONDITIONS COULD DEVELOP AS IT MOVES
INTO NORTHERN CAMPBELL COUNTY WITH THE UPSLOPE SURFACE FLOW.
ELSEWHERE THE STRONGEST AFTERNOON CONVECTION IS CONFINED TO
EASTERN PARTS OF SOUTH DAKOTA AND NROTH CENTRAL NEBRASKA. MVFR
CONDITIONS POSSIBLE IN HEAVIER STORMS. OTHERWISE...VFR CONDITIONS
WILL PREVAIL THROUGH THE EVENING. GUSTY NORTHWEST WINDS TO 35 KTS
WILL CONTINUE TO GRADUALLY SUBSIDE DURING THE EVENING HOURS.
GUSTY NORTHWEST WINDS ARE EXPECTED AGAIN SATURDAY.
&&
.PREV DISCUSSION... /ISSUED 253 PM MDT FRI AUG 3 2012/
DISCUSSION...UPPER LEVEL ANALYSIS HAS LOW PRESSURE OVER FAR
SOUTHWESTERN SK MOVING SLOWLY EASTWARD...WITH SOUTHWESTERLY FLOW
AHEAD OF IT ACROSS THE NORTHERN PLAINS. CURRENT SURFACE ANALYSIS
SHOWS COLD FRONT STRETCHING FROM NORTHEASTERN ND THROUGH CENTRAL SD
AND INTO THE NEBRASKA PANHANDLE. TIGHTENING PRESSURE GRADIENT
BEHIND THE FRONT IS PRODUCING GUSTY NORTH TO NORTHWEST WINDS
ACROSS MUCH OF THE WESTERN SD PLAINS. THE STRONGEST WINDS ARE IN
THE RAPID CITY AREA...WHERE A FEW GUSTS TO AROUND 50 MPH HAVE BEEN
NOTED. SKIES RANGE FROM MOSTLY CLOUDY ACROSS FAR NORTHEASTERN WY
AND NORTHWESTERN SD TO MOSTLY SUNNY ACROSS SOUTHERN SD. MAIN BAND
OF SHOWERS AND THUNDERSTORMS IS STAYING NORTH OF THE CWA SO
FAR...CLOSER TO THE UPPER LOW. THUNDERSTORMS HAVE ALSO DEVELOPED
ALONG THE FRONT FROM CENTRAL ND INTO NORTH CENTRAL SD. TEMPS
CURRENTLY RANGE FROM THE UPPER 60S ACROSS PORTIONS OF
NORTHEASTERN WY AND NORTHWESTERN SD...TO THE 90S OVER SOUTH
CENTRAL SD.
COLD FRONT WILL MOVE SLOWLY EAST ACROSS CENTRAL SD LATE THIS
AFTERNOON AND INTO EASTERN SD THIS EVENING. UPPER LOW WILL TRACK
EAST ACROSS FAR SOUTHERN SK THROUGH TONIGHT. GUSTY WINDS WILL
CONTINUE THROUGH THE LATE AFTERNOON AND THEN GRADUALLY DECREASE
THIS EVENING. THE BEST CHANCES FOR SHOWERS AND STORMS WILL BE
ALONG THE FRONT ACROSS CENTRAL SD LATE THIS AFTERNOON INTO
TONIGHT. SUFFICIENT INSTABILITY AND SHEAR REMAINS ALONG AND AHEAD
OF THE FRONT ACROSS FAR SOUTH CENTRAL SD TO ALLOW FOR A THREAT OF
A SEVERE THUNDERSTORM OR TWO OVER THE NEXT HOUR OR TWO.
HOWEVER...THE BETTER THREAT FOR SEVERE STORMS WILL CLEARLY BE
ACROSS EASTERN SD THROUGH THIS EVENING. STRONG WIND GUSTS WOULD BE
THE MAIN THREAT FROM ANY SEVERE STORMS...BUT LARGE HAIL IS ALSO A
POSSIBILITY. A FEW SHOWERS AND STORMS ARE ALSO POSSIBLE OVER
NORTHEASTERN WY AND SOUTHWESTERN SD LATE THIS AFTERNOON INTO THIS
EVENING AS WEAK SHORTWAVE ENERGY CROSSES ON THE SOUTHERN SIDE OF
THE TROF AND INTERACTS WITH WEAK INSTABILITY REMAINING OVER THE
AREA. THE POSSIBILITY FOR SHOWER COULD LINGER ACROSS SOUTH
CENTRAL SD OVERNIGHT AS THE BACK END OF THE WAVE CROSSES. TEMPS
WILL BE PLEASANTLY COOL IN MOST AREAS OVERNIGHT...WITH LOWS
MOSTLY IN THE 50S...SOME 40S OVER THE BLACK HILLS AND NORTHEASTERN
WY.
THE WEEKEND LOOKS TO BE VERY NICE WITH MOSTLY CLEAR SKIES
EXPECTED. TEMPS WILL BE PLEASANTLY COOL ON SATURDAY...WITH HIGHS
IN THE 70S AND LOWER 80S AS CANADIAN HIGH PRESSURE MOVES INTO THE
AREA LATE IN THE DAY. BREEZY NORTHWESTERLY WINDS CAN BE EXPECTED
DURING THE LATE MORNING AND EARLY AFTERNOON HOURS ACROSS THE
PLAINS BEFORE THE HIGH BUILDS IN. LIGHT WINDS...CLEAR SKIES...AND
DRY AIR WILL ALLOW FOR GOOD RADIATIONAL COOLING SATURDAY
NIGHT...WITH LOWS IN THE MID 40S TO MID 50S AT MOST LOCATIONS. AS
THE HIGH MOVES EAST OF THE REGION LATE SATURDAY NIGHT/EARLY
SUNDAY AND RIDGING BUILDS OVER THE ROCKIES...WARMER AIR WILL BEGIN
TO ADVECT BACK INTO THE AREA. SOUTH TO SOUTHEAST WINDS WILL DEVELOP
ON SUNDAY WITH TEMPS RISING TO THE UPPER 80S TO MID 90S ON THE
PLAINS...80S ACROSS THE BLACK HILLS.
EXTENDED...RESURGENCE OF THE CENTRAL/WESTERN NOAM RIDGE EXPECTED IN
THE PERIOD...WITH THE REGION REMAINING ON THE EDGE OF FAST DISTURBED
UPPER LEVEL FLOW. SEMI-PERMANENT NE PAC UPPER TROUGH WILL TEND TO
SUPPORT FAST FLOW ALOFT NEARBY WITH PERIODIC SUBTLE SHORTWAVE
IMPULSES EXPECTED IN THE FLOW SUPPORTING SOME TS CHANCES IN THE
PERIOD...PRIMARILY TUES THROUGH THUR ATTM. OVERALL RAIN CHANCES DO
REMAIN BLEAK GIVEN LACK OF DEEP MOISTURE...WITH VERY LIMITED
COVERAGE OF ANY STORMS THAT DO MATERIALIZE. WAVE TIMING STILL TO BE
RESOLVED TO FURTHER DELINEATE AREAL/TIMING DETAIL. THUS RETAINED POP
VALUES VERY CLOSE TO PREVIOUS FORECAST NUMBERS...RETAINING
CONSISTENCY. H7 GEFS TEMP ANOMALIES SUGGEST 1-2 STD DEVIATIONS ABOVE
CLIMO THROUGH MUCH OF THE PERIOD...ESP TUE ON...THUS A TREND TO THE
HIGH SIDE OF GUIDANCE WAS WARRANTED PER HIGHS. REMOVAL OF DEEP
MOISTURE WITH OVERALL LIGHT OVERNIGHT FLOW IN MANY PERIODS SUGGEST
DECENT RADIATIONAL COOLING...WITH PREFERENCE TOWARD MID GUIDANCE
NUMBERS PER LOWS. OVERALL...EXPECT ABOVE NORMAL TEMPS TO CONTINUE
IN THE PERIOD...WITH NORMAL TO BELOW NORMAL CHANCES FOR PRECIP.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...CARPENTER
LONG TERM....WFO UNR
AVIATION...CARPENTER
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
126 PM CDT THU AUG 2 2012
.DISCUSSION...
UPDATED FOR 18Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 1136 AM CDT THU AUG 2 2012/
UPDATE...
WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE
TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF
MISSOURI INTO CLAY COUNTY ARKANSAS.
KRM
PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/
REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS
MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO
DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE
KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO
NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE
UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA
TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS
AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO
THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY
AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND
NOON TO REMOVE MORNING WORDING.
KRM
DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/
FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE
WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO
DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST
HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT
WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT
MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS
MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST
DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD
COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S.
ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND
EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL
ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR
AN AFTERNOON SHOWER OR STORM.
THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING
CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD
AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI
THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT.
THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE
CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A
FEW SEVERE STORMS.
NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH
CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S.
HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY
CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED.
SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT
SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES.
THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT
SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY
NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW
SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO
MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE
DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE
THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY
MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO
CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY
SUNNIER SKIES.
EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST
FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO
THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE
FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE
LOW TO MID 90S.
JAB
&&
.AVIATION...
EARLIER SHOWERS AND THUNDERSTORMS HAVE WORKED OVER THE AIRMASS
ACROSS AT LEAST THE WESTERN HALF OF THE MID SOUTH. RECENT RADAR
TRENDS HAVE BEEN UNIMPRESSIVE AND THE CU FIELD IS STRUGGLING TO
DEVELOP. LOOKS LIKE THE BEST CHANCE FOR TSRAS THIS AFTN WILL BE
AT KTUP. ELSW CHANCES ARE LOW ENOUGH TO REMOVE THE VCTS FOR THE
REST OF THE AFTN. THE NEXT UPPER LEVEL DISTURBANCE...LOCATED OVER
NRN MO ATTM...WILL TRIGGER ANOTHER ROUND OF TSRAS THIS AFTERNOON
THAT WILL MOVE INTO THE MIDSOUTH THIS EVENING AND OVERNIGHT.
ADJUSTED VCTS TIMING TO REFLECT THIS THINKING. WINDS WILL
GENERALLY BE S/SW AT 8-12 KTS THIS AFTERNOON...DIMINISHING THIS
EVENING.
SJM
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 96 79 93 77 / 30 40 40 20
MKL 96 73 88 74 / 40 60 50 20
JBR 96 74 95 75 / 40 50 40 30
TUP 95 76 90 74 / 30 20 50 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-
RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO-
TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1136 AM CDT THU AUG 2 2012
.UPDATE...
WENT AHEAD AND BUMPED UP POPS ACROSS THE NORTHEAST HALF OF CWA DUE
TO THE THUNDERSTORM ACTIVITY BEGINNING TO POP UP NEAR POPLAR BLUFF
MISSOURI INTO CLAY COUNTY ARKANSAS.
KRM
&&
.PREV DISCUSSION... /ISSUED 1030 AM CDT THU AUG 2 2012/
REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS
MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO
DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE
KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO
NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE
UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA
TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS
AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO
THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY
AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND
NOON TO REMOVE MORNING WORDING.
KRM
&&
.DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/
FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE
WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO
DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST
HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT
WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT
MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS
MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST
DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD
COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S.
ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND
EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL
ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR
AN AFTERNOON SHOWER OR STORM.
THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING
CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD
AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI
THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT.
THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE
CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A
FEW SEVERE STORMS.
NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH
CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S.
HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY
CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED.
SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT
SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES.
THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT
SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY
NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW
SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO
MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE
DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE
THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY
MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO
CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY
SUNNIER SKIES.
EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST
FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO
THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE
FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE
LOW TO MID 90S.
JAB
&&
.AVIATION...
12Z TAF CYCLE (02/12Z-03/12Z)
SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR
HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS
MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL
15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY
DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED
TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION
OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH
DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY
MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW
INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER
03/09Z.
WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT
SOUTHERLY 4-8 KTS.
JCL
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 96 76 94 77 / 30 20 40 20
MKL 96 73 90 74 / 40 40 50 20
JBR 96 75 93 75 / 40 20 40 10
TUP 95 74 91 73 / 30 40 50 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-
RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO-
TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1030 AM CDT THU AUG 2 2012
.UPDATE...
REMNANTS FROM A MCS CONTINUE TO SKIRT EASTERN ARKANSAS THIS
MORNING. THE LATEST HRRR RUN SHOWS THE AREA OF RAIN TO CONTINUE TO
DISSIPATE AS THE AREA OF PRECIPITATION PUSHES SOUTH. CLOUDS HAVE
KEPT TEMPERATURES DOWN FROM NORTHEAST ARKANSAS...TO MEMPHIS TO
NORTHWEST MISSISSIPPI. CURRENT TEMPERATURES ARE RUNNING IN THE
UPPER 70S TO LOWER 80S. MEANWHILE...ACROSS THE REST OF THE CWA
TEMPERATURES ARE IN MID 80S. RELUCTANT TO LOWER HIGHS AT MEMPHIS
AND JONESBORO AS LATEST SATELLITE IMAGES SHOW CLOUDS PUSHING TO
THE SOUTH AND WEST. THUS EXPECT THE SUN TO PEAK THROUGH BY
AFTERNOON. CURRENT FORECAST HAS A GOOD HANDLE...WILL UPDATE AROUND
NOON TO REMOVE MORNING WORDING.
KRM
&&
.DISCUSSION... /ISSUED 352 AM CDT THU AUG 2 2012/
FOR TODAY AND TONIGHT...NORTHWESTERLY FLOW AROUND THE UPPER RIDGE
WILL CONTINUE FOR THE MIDSOUTH OVER THE NEXT 24 HOURS. TWO
DISTINCT DISTURBANCES ARE EXPECTED TO AFFECT THE REGION. THE FIRST
HAS BEEN GENERATING CONVECTION OVER CENTRAL ARKANSAS ALL NIGHT
WITH AN EVER SO TENDENCY TO SLIDE EASTWARD. THIS WILL AFFECT
MAINLY THE COUNTIES ALONG AND WEST OF THE MISSISSIPPI RIVER THIS
MORNING. HAVE LIFTED THE CURRENT HEAT ADVISORY FOR THE SOUTHWEST
DELTA COUNTIES AS THIS AREA WILL SEE THE LONGEST STRETCH OF CLOUD
COVER THROUGHOUT THE DAY KEEPING TEMPERATURE HIGHS IN THE LOW 90S.
ELSEWHERE...EXPECT DECREASING CLOUD COVER TOWARDS THE NORTH AND
EAST...WITH TEMPERATURES CLIMBING INTO THE MID 90S. THIS WILL
ALLOW FOR HEAT INDICES TO REACH 105 DEGREES DESPITE THE THREAT FOR
AN AFTERNOON SHOWER OR STORM.
THE SECOND DISTURBANCE IS MORE POTENT AND IS GENERATING
CONVECTION ACROSS NORTHEAST KANSAS. MODELS ARE IN VERY GOOD
AGREEMENT THAT THIS SHORTWAVE WILL SLIDE INTO EASTERN MISSOURI
THIS AFTERNOON AND DOWN TO THE TENNESSEE RIVER VALLEY TONIGHT.
THE EASTERN HALF OF THE MIDSOUTH WILL HAVE A BETTER CHANCE TO SEE
CONVECTION WITH THIS FEATURE...ALONG WITH A THE POSSIBILITY OF A
FEW SEVERE STORMS.
NOT MUCH CHANGE IS ANTICIPATED FOR FRIDAY AND SATURDAY WITH
CONTINUED RAIN CHANCES AND TEMPERATURES IN THE LOW TO MID 90S.
HEAT INDICES FOR NOW APPEAR TO BE JUST BELOW THE 105F ADVISORY
CRITERIA AS MORE EXTENSIVE CLOUD COVER IS EXPECTED.
SUNDAY...TIMING OF MODELS IS STILL ON TRACK WITH A POTENT
SHORTWAVE CROSSING THE NORTHERN PLAINS AND WESTERN GREAT LAKES.
THIS ENERGY WILL FLATTEN THE RIDGE AND SWING A COLD FRONT
SOUTHEAST INTO OUR AREA. THUS RAIN CHANCES REMAIN FAVORABLE SATURDAY
NIGHT THROUGH MONDAY MORNING WITH A CONTINUED THREAT FOR A FEW
SEVERE STORMS. TEMPERATURES THIS PERIOD WILL REMAIN IN THE LOW TO
MID 90S. BEHIND THE FRONT SLIGHTLY DRIER AIR...MAINLY 60 DEGREE
DEWPOINTS WILL MOVE INTO THE NORTHERN COUNTIES ON MONDAY AND MAKE
THEIR WAY AS FAR SOUTH AS THE TENNESSEE/MISSISSIPPI BORDER BY
MONDAY EVENING. TEMPERATURES BEHIND THE FRONT AREN`T EXPECTED TO
CHANGE MUCH AS THE SLIGHTLY COOLER AIR WILL ONLY BE OFFSET BY
SUNNIER SKIES.
EXTENDED PERIOD HAS THE MIDSOUTH BACK INTO THE PESKY NORTHWEST
FLOW. HOWEVER THE BRUNT OF DISTURBANCES APPEAR TO STAY NORTH INTO
THE SOUTHERN LAKES AND OHIO VALLEY...SO FOR NOW HAVE KEPT THE
FORECAST DRY WITH HIGH TEMPERATURES REMAINING CONSISTENT IN THE
LOW TO MID 90S.
JAB
&&
.AVIATION...
12Z TAF CYCLE (02/12Z-03/12Z)
SHOWERS AND THUNDERSTORMS IN A BAND ACROSS PORTIONS OF EASTERN AR
HAVE BEEN MOVING MAINLY NORTH TO SOUTH EARLIER THIS
MORNING...REMAINING WEST OF KJBR. DID MENTION VCSH AT KJBR UNTIL
15Z AND WILL MONITOR FOR AMENDING TO ADD VCTS IF THE ACTIVITY
DOES CREEP FURTHER EASTWARD. OTHERWISE VFR CONDITIONS ARE EXPECTED
TO PREVAIL MOST OF THE PERIOD AT THE TAF SITES. CONTINUED MENTION
OF VCTS AT ALL THE TAF SITES THIS AFTERNOON AND EARLY EVENING WITH
DAYTIME HEATING. MODELS INDICATE A MESOSCALE CONVECTION SYSTEM MAY
MOVE INTO THE REGION FROM THE NORTH LATE TONIGHT...FOR NOW
INCLUDED VCTS AT KJBR AND KMKL AFTER 03/06Z AND AT KMEM AFTER
03/09Z.
WINDS MAINLY S TO SW BECOMING 8-12 KTS TODAY...WINDS TONIGHT
SOUTHERLY 4-8 KTS.
JCL
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 96 76 94 77 / 30 20 40 20
MKL 96 73 90 74 / 30 40 50 20
JBR 96 75 93 75 / 40 20 40 10
TUP 95 74 91 73 / 30 40 50 20
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CLAY-CRAIGHEAD-
CRITTENDEN-CROSS-GREENE-LAWRENCE-MISSISSIPPI-POINSETT-
RANDOLPH-ST. FRANCIS.
MO...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR DUNKLIN-PEMISCOT.
MS...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ALCORN-BENTON MS-
CALHOUN-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-MARSHALL-
MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TISHOMINGO-
TUNICA-UNION-YALOBUSHA.
TN...HEAT ADVISORY UNTIL 7 PM CDT THIS EVENING FOR CARROLL-CHESTER-
CROCKETT-DECATUR-DYER-FAYETTE-GIBSON-HARDEMAN-HARDIN-
HAYWOOD-HENDERSON-HENRY-LAKE-LAUDERDALE-MADISON-MCNAIRY-
OBION-SHELBY-TIPTON-WEAKLEY.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
747 PM EDT FRI AUG 3 2012
.SYNOPSIS...
SEVERAL UPPER LEVEL DISTURBANCES WILL MOVE EAST ACROSS OUR REGION
TONIGHT INTO SATURDAY. ALOFT...A LARGE RIDGE OF HIGH PRESSURE COVERED
TEXAS...THIS RIDGE FORECAST TO EXPAND OVER THE SOUTHEAST AND THE
MIDDLE ATLANTIC THROUGH THE WEEKEND. A COLD FRONT WILL DROP SOUTH
FROM THE GREAT LAKES AND THE OHIO VALLEY EARLY NEXT WEEK...THE
RESULT OF AN AGGRESSIVE UPPER LEVEL TROUGH WHICH IS FORECAST TO
MOVE THROUGH THE GREAT LAKES AND OHIO VALLEY REGION SUNDAY INTO
MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 725 PM EDT FRIDAY...
LARGE AREA OF SHOWERS WITH EMBEDDED THUNDERSTORMS ACROSS FAR SW VA
INTO NE TN IN ASSOCIATION WITH UPPER SHORTWAVE SHOULD MOVED EWD
THROUGH THE EVENING AFFECTING MOST LOCATIONS WEST OF I-77 IN
VA/WV. THUNDERSTORMS HAVE BEEN WEAKENING WITH AIRMASS STABILIZING
UNDER COOLING RAINS. THE REST OF THE AREA SHOULD STAY IN A
ISOLATED TO SCATTERED COVERAGE INTO THE EVENING WITH HEAVY RAIN
POSSIBLE AT TIMES. OTHERWISE...NOT MANY OTHER CHANGES TO THE
FORECAST.
PREVIOUS DISCUSSION AT 400 PM...
COMPLICATED FORECAST WITH PLACEMENT OF CONVECTION THIS EVENING
INTO TONIGHT. THE LOW CLOUDS WHICH LIFTED NORTH ACROSS THE REGION
THIS MORNING ESPECIALLY ALONG THE EASTERN SLOPES OF BLUE RIDGE HAS
SLOWED THE DEVELOPMENT OF THE THUNDERSTORMS THIS AFTERNOON AND
HINDERED INSTABILITY. KFCX 88D SHOWED ISOLATED TO WIDELY SCATTERED
SHOWERS AND THUNDERSTORMS DEVELOPING AHEAD OF AREAS OF CONVECTION
ACROSS EASTERN KENTUCKY. THIS CONVECTION IS ASSOCIATED WITH
SHORTWAVE MOVING SLOWLY ESE. OUTFLOW AND LEFTOVER BOUNDARIES FROM
THUNDERSTORMS WILL MOVE ACROSS OUR REGION THIS EVENING INTO
TONIGHT.
CONVECTION WHICH FIRES ALONG THE UPPER LEVEL DISTURBANCE
ALONG THE CAROLINA COAST... MAY SEND AXIS OF DEEPER MOISTURE
NORTHWARD INTO OUR SE CWA INITIATING LATE AFTERNOON AND EVE
SHRA/TSRA. NAM...GFS...WRFARW-RNK AND HRRR PLACE THE HIGHEST POPS
ACROSS SOUTHWEST PORTION OF CWA THIS AFTERNOON INTO TONIGHT.
OVERALL...DEEP LAYER WINDS ACROSS THE MID ATLANTIC REGION
REMAIN WEAK...MEAN WIND LESS THAN 10 KTS. ANY DEEP CONVECTION THAT
DEVELOPS WILL BE SLOW MOVING WITH POTENTIAL OF HEAVY RAINS. TAPER
OFF POPS WITH THE LOSS OF SOLAR HEATING TONIGHT BUT HOLD ON TO SOME
ACTIVITY IN THE SOUTHWEST.
LEANED LOW TEMPERATURES TONIGHT TOWARDS THE ADJMET WITH THE IDEA OF
MORE CLOUDINESS KEEPING TEMPERATURES ELEVATED. ALSO ADD THE MENTION
OF PATCHY FOG OVERNIGHT WHICH CAN BE SHAPED TO WHERE THUNDERSTORMS
OCCUR.
DEEPER MOISTURE WILL REMAIN IN PLACE ESPECIALLY OVER THE WEST
SATURDAY. WEAKENING MID LEVEL WAVE AND OLD BOUNDARIES REMAINS ALONG
THE MOUNTAINS SATURDAY AFTERNOON DURING MAX HEATING. THE COMBINATION
OF W/NW FLOW ALOFT AND DECENT INSTABILITY WEST APPEARS TO BE A GOOD
SETUP FOR MULTICELLULAR BANDS ACROSS THE MOUNTAINS...WITH SOME OF
THIS ACTIVITY ABLE TO SPILL EAST OF THE BLUE RIDGE LATE. INCREASED
POPS AND EXTENDED CHANCES OUT EAST TO THE PIEDMONT. SHAPED TIMING
AND POPS CLOSE TO NAM. PLAYED HIGH CLOSER TO COOL MOS BECAUSE OF
CLOUD COVER WITH READINGS FROM THE MID 70S IN THE MOUNTAINS TO
AROUND 90 DEGREES IN THE SOUTHEAST.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 330 PM EDT FRIDAY...
SCATTERED LINGERING SHOWERS AND STORMS LATE SATURDAY ARE LIKELY TO
QUICKLY DISSIPATE BY LATE EVENING AS LITTLE IN THE WAY OF ORGANIZED
FORCING IS EXPECTED IN GENERALLY SOUTHERLY FLOW. THE 12Z GFS
PRODUCES SOME CONVECTIVELY INDUCED SHORT WAVES OVER TN/KY AND TRIES
TO CONTINUE SOME ACTIVITY MOST OF THE NIGHT ACROSS THE WEST BUT FEEL
THIS IS PROBABLY OVERDONE TO LARGE DEGREE...WHEREAS NAM HAS NOTHING ACROSS
THE WEST BUT CONTINUES CONVECTION ACROSS THE FAR EAST WELL PAST
MIDNIGHT IN ASSOC WITH A VERY WEAK LEE TROUGH. NOT SURE HOW MUCH TO
TRUST EITHER SOLUTION...BUT WILL LEAN MORE TOWARD THE GFS NOTION OF
KEEPING CHANCES GOING A LITTLE LONGER IN THE WEST...BUT WILL DROP
POPS QUICKLY AFTER MIDNIGHT.
SUNDAY APPEARS TO HAVE BETTER CHANCES...ESPECIALLY LATER IN THE DAY
OUT AHEAD OF APPROACHING FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY.
SOME INCREASE IN SHEAR AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A
BETTER SEVERE POTENTIAL AS WELL...WITH MORE ORGANIZED CLUSTERS
COMING OUT OF OF WV AHEAD OF FRONT. MAIN THREAT DURING THE DAY WOULD
MAINLY BE IN THE WEST. EXACT TIMING IS IN QUESTION...INCLUDING
WHETHER THERE WILL BE STORMS WELL OUT AHEAD OF FRONT DEVELOPING WITH
MAX HEATING AND OVER HIGHER TERRAIN...OR DOES IT WAIT UNTIL FRONTAL
BOUNDARY ACTUALLY ARRIVES WHICH WOULD BE MORE EVENING AND EVEN
OVERNIGHT IN THE WEST. SEVERE CHANCES MUCH LESS EAST OF THE BLUE
RIDGE GIVEN TIMING OF FRONT...BUT IF ANYTHING DEVELOPS WELL OUT
AHEAD...A FEW OF THESE STORMS COULD DRIFT INTO THE PIEDMONT LATE IN
THE DAY. IN ANY CASE...EXPECT AT LEAST MORE CLOUD COVER FROM
UPSTREAM CONVECTION TO KEEP TEMPS DOWN A BIT IN THE WEST...SO WENT
CLOSER TO COOLER MET GUIDANCE IN WEST...AND WARMER MAV IN EAST.
BOUNDARY SLOWLY DRIFTS ACROSS THE FCST AREA SUNDAY NIGHT INTO
MONDAY...AND MUCH BETTER CHANCE FOR LINGERING CONVECTION OR AT LEAST
SHOWERS MOST OF THE NIGHT SUNDAY NIGHT...AND ANY REDEVELOPMENT OF
DEEPER CONVECTION MONDAY WOULD BE ACROSS THE SOUTHEAST...AND
DEPENDENT ON ANY SMALL DEGREE OF SFC HEATING...BUT SEVERE CHANCES
SHOULD BE MUCH LOWER DUE TO LACK OF GOOD HEATING MONDAY. MONDAY
MORNING LOWS SHOULD BE PRETTY MILD WITH MOSTLY CLOUDY AND EVEN
ONGOING SHOWERS...AND MAV NUMBERS LOOK GOOD THERE WITH LOW TO MID
70S FOR MINS IN PIEDMONT AND UPPER 60S TO NEAR 70 WEST. SLIGHTLY
COOLER TEMPS FOR MONDAY...ESPECIALLY BEHIND BOUNDARY IN WEST...BUT
IN THE EAST WEVMAY NEED TO DROP TEMPS A LITTLE MORE IN THE EAST IF IT
LOOKS LIKE CLOUDS AND SHOWERS WILL NOT GIVE WAY TO ANY SUNSHINE AT
ALL DURING THE DAY MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 1230 PM EDT FRIDAY...
THE WEATHER PATTERN THROUGH MUCH OF NEXT WEEK WILL BE INFLUENCED BY
BOTH A STRONG RIDGE OF WARM HIGH PRESSURE OVER MUCH OF THE COUTH
CENTRAL PORTIONS OF THE COUNTRY...AS WELL AS A DEVELOPING WEAK
TROUGH ACROSS THE NORTHEAST WITH ASSOCIATED SLOW MOVING WEAK FRONTAL
BOUNDARYS MOVING IN FROM THE NORTHWEST. THESE FEATURES WILL KEEP TEMPERATURES
NEAR SEASONABLE READINGS THROUGH THE WEEK...WITH A CONTINUING CHANCE
FOR SHOWERS AND THUNDERSTORMS ON MOST DAYS.
MORE SPECIFICALLY...THE FRONTAL BOUNDARY SLOWLY MOVING ACROSS THE
APPALACHIAN REGION ON MONDAY WILL LIKELY BE LINGERING ACROSS THE
PIEDMONT INTO MONDAY NIGHT AND TUESDAY...BEFORE WASHING OUT ACROSS
THE CAROLINAS. THERE ARE SIGNS IN SOME OF THE GUIDANCE OF A WEAK
WAVE MOVING UP FROM THE SOUTHWEST...SO WHILE EXPECTING BETTER
COVERAGE OF SHOWERS AND STORMS CLOSER TO THE FRONT IN THE EASTERN
HALF OF THE FCST AREA TUESDAY...CAN ELIMINATE CHANCES FARTHER WEST
GIVEN THIS POSSIBLE WAVE. WITH FAIRLY GOOD CLOUD COVER LIKELY...THIS
COULD BE COOLEST DAY OF THE WEEK FOR SOME AREAS. WEDNESDAY WILL HAVE
LESS OF A FOCUSING MECHANISM...BUT WITH WEAK TROUGH DEVELOPING
OVERHEAD...AND MORE SUNSHINE PROBABLE...COULD RESULT IN STEEPER
LAPSE RATES OVERALL...SO WORTH KEEPING CHC FOR SCATTERED AFTERNOON
CONVECTION. PROBABLY BETTER CHANCES ACROSS THE SOUTHEAST...IF
LINGERING CONVERGENCE WITH OLD BOUNDARY IS STILL PRESENT. BY THURS
AND FRIDAY WILL HAVE TO RELY MORE ON DAYTIME HEATING AND LINGERING
LOW LEVEL MSTR...BUT WITH WEAK TROUGH ALOFT AND NO PUSH OF DRIER AIR
EVIDENT...FEEL ITS WORTH KEEPING LOW CHC POPS. ON FRIDAY THE
INFLUENCE OF ANOTHER WEAK FRONT TO THE NORTH MAY BE ENOUGH TO
PROVIDE SLIGHTLY BETTER CHANCES...BUT BY THIS TIME THERE IS ENOUGH
DIFFERENCE IN MODEL GUIDANCE...WITH SOME HOLDING THIS FRONT OFF
UNTIL SAT OR LATER...NOT TO PUT MUCH EMPHASIS ON MUCH OF A CHANGE
BETWEEN THURS AND FRIDAY. WITH GENERALLY MORE SUN BY MID TO LATE
WEEK ONCE THE FRONT FROM EARLY IN THE WEEK GOES BY AND
WEAKENS...EXPECTING A VERY GRADUAL WARMING TREND BY LATE IN THE
WEEK...WITH PIEDMONT HIGH TEMPS REACHING BACK INTO THE LOW TO MID
90S BY LATE IN THE WEEK.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 PM EDT FRIDAY...
WATCHING CONVECTION NEAR LYH/DAN AND BLF THIS EVENING BUT THINKING
WEAKENING TREND CONTINUES SO NOT ALLOWING ANY THUNDER EXCEPT VCTS
AT BLF. WILL HAVE TO SEE HOW THINGS EVOLVE OVERNIGHT WITH SHOWERS
IN THE FAR SOUTHWEST VA AREA NUDGING EWD. THINK BLF WILL SEE
SHOWERS INTO THE EVENING WITH CIGS/VSBYS STAYING MAINLY VFR BUT
COULD SEE VSBYS SINK INTO MVFR WITH HEAVY RAIN.
THE REST OF THE AREA WILL BE MUGGY WITH SOME FOG FORMING
ESPECIALLY WHERE IT RAINED. AN ISSUE COULD BE CLOUD COVER WHICH
COULD IMPEDE HOW LOW VSBYS GO. CONFIDENT ENOUGH ON BCB/LWB
DROPPING TO LIFR OVERNIGHT WITH DAN/LYH/ROA STAYING IFR/MVFR WHILE
BLF CLEARS OUT ENOUGH LATE TO DROP AROUND 1SM.
THE FOG WILL DISSIPATE SLOWLY SAT MORNING AND MODELS SHOWING THE
NEXT WAVE OF STORMS MOVING INTO THE MTNS AROUND 15-18Z THEN EAST
IN THE AFTN. WILL KEEP VCTS AT ALL SITES EXCEPT DAN WITH VFR
CIGS/VSBYS.
DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF
SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH
DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED
WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY
DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE
FROM OVERNIGHT VALLEY FOG.
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY
MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF
THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF
DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR
MID WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...KK/WP
SHORT TERM...SK
LONG TERM...SK
AVIATION...KK/WP
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1051 PM CDT FRI AUG 3 2012
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISOLATED SHOWERS AND STORMS PERSIST OVER CENTRAL WISCONSIN EARLY
THIS EVENING ALONG A SUBTLE BOUNDARY. PREVIOUSLY HANDLED THIS
CONVECTION WITH NOWCASTS. BUT WILL NOW UPDATE TO ADD TO THE ZONE
FORECASTS DUE TO WATER VAPOR LOOP SHOWS SOME MID LEVEL DRYING
WORKING INTO CENTRAL WISCONSIN THIS EVENING. ITS POSSIBLE THIS
MAY INTENSIFY THE ONGOING CONVECTION OR INCREASE THE CONVECTION
ALONG THE BOUNDARY.
TDH
&&
.PREV DISCUSSION...ISSUED AT 651 PM CDT FRI AUG 3 2012...
SHORT TERM...TODAY THROUGH SATURDAY.
IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO
EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD
DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z
RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN
3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT.
BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME.
SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS
MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD
RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES
TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM
TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY
INCREASING CLOUD COVER.
THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY.
WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT
WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF
UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING
DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE
STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER
SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL
LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF
INSTABILITY SATURDAY AFTERNOON.
TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH
ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N
WITH MORE CLOUDS AND PRECIP TO START THE DAY.
ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR
TWEAKING WAS NEEDED.
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND
CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY.
...SATURDAY NIGHT AND SUNDAY...
COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z
SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER
SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS
FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL
SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE
BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE
HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING.
AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY.
THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF
CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY
AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB
TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND
THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH
THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS
AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY
NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA.
GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH
TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH
CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY
COLD SUNDAY NIGHT.
...MONDAY THROUGH FRIDAY...
HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH
WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF
CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT
INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE.
BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE
SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO
NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK.
&&
.AVIATION...LINE OF STORMS JUST WEST OF THE WISCONSIN/MINNESOTA
BORDER LATE EVENING WILL BE MARCHING ACROSS WESTERN WISCONSIN BY
MIDNIGHT BEFORE WORKING TOWARD CENTRAL AND NORTH CENTRAL WISCONSIN
EARLY THIS MORNING. SEVERE WEATHER WAS OBSERVED WITH THIS LINE
OVER WESTERN MINNESOTA BUT HAS DIMINISHED. ALONG WITH THE
CONVECTION DEBRIS CLOUDS WITH AREAS OF MVFR CIGS AND VSBYS CAN BE
EXPECTED.
MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL
PASS OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND
STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS. A
FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL WISCONSIN
EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND EVENING OVER
EASTERN WISCONSIN.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
728 PM CDT FRI AUG 3 2012
.UPDATE...
ISOLATED SHOWERS AND STORMS PERSIST OVER CENTRAL WISCONSIN EARLY
THIS EVENING ALONG A SUBTLE BOUNDARY. PREVIOUSLY HANDLED THIS
CONVECTION WITH NOWCASTS. BUT WILL NOW UPDATE TO ADD TO THE ZONE
FORECASTS DUE TO WATER VAPOR LOOP SHOWS SOME MID LEVEL DRYING
WORKING INTO CENTRAL WISCONSIN THIS EVENING. ITS POSSIBLE THIS
MAY INTENSIFY THE ONGOING CONVECTION OR INCREASE THE CONVECTION
ALONG THE BOUNDARY.
TDH
&&
.PREV DISCUSSION...ISSUED AT 651 PM CDT FRI AUG 3 2012...
SHORT TERM...TODAY THROUGH SATURDAY.
IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO
EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD
DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z
RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN
3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT.
BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME.
SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS
MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD
RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES
TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM
TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY
INCREASING CLOUD COVER.
THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY.
WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT
WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF
UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING
DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE
STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER
SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL
LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF
INSTABILITY SATURDAY AFTERNOON.
TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH
ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N
WITH MORE CLOUDS AND PRECIP TO START THE DAY.
ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR
TWEAKING WAS NEEDED.
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND
CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY.
...SATURDAY NIGHT AND SUNDAY...
COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z
SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER
SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS
FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL
SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE
BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE
HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING.
AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY.
THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF
CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY
AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB
TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND
THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH
THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS
AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY
NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA.
GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH
TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH
CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY
COLD SUNDAY NIGHT.
...MONDAY THROUGH FRIDAY...
HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH
WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF
CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT
INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE.
BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE
SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO
NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK.
&&
.AVIATION...SUBTLE BOUNDARY LIFTING OVER CENTRAL WISCONSIN THIS
EVENING WAS PRODUCING VERY ISOLATED SHOWERS AND STORMS AT TIMES.
THE SHOWERS AND STORMS DURATION WERE RELATIVELY SHORT LIVED.
OTHERWISE DEBRIS CLOUDS AND CONVECTION FROM A CLUSTER OF SHOWERS
AND STORMS OVER THE DAKOTAS MAY WORK INTO THE WESTERN HALF OF THE
STATE OVERNIGHT. MVFR CIGS MAY WORK INTO CENTRAL AND NORTH CENTRAL
WISCONSIN OVERNIGHT.
MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL PASS
OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND
STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS.
A FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL
WISCONSIN EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND
EVENING OVER EASTERN WISCONSIN.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
651 PM CDT FRI AUG 3 2012
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SATURDAY.
IN THE NEAR-TERM...SC SLOWLY DISSIPATED DURING THE DAY THANKS TO
EASTERLY LOW-LEVEL FLOW. AS CONVECTIVE TEMP IS MET...CU FIELD
DEVELOPS...AS SEEN ON LATEST VIS SATELLITE IMAGERY. BOTH 03/15Z
RUNS OF HRRR AND RAP INDICATE ISOLATED CONVECTION IN NE WI BETWEEN
3 AND 6 PM...NOT UNLIKE YESTERDAY`S EARLY EVENING ISOLATED EVENT.
BUT PROBABILITY TOO LOW TO INCLUDE IN GRIDS AT THIS TIME.
SHARP UPPER TROUGH WILL PRODUCE GOOD UPPER DIFFLUENCE ACROSS
MINNESOTA TONIGHT. THAT COUPLED WITH A MODEST LOW LEVEL JET SHOULD
RESULT IN CONVECTION THAT COULD DRIFT INTO OUR WESTERN COUNTIES
TOWARD MORNING. BOTH THE 03/12Z NAM AND GFS HINT AT THIS. MINIMUM
TEMPERATURES SHOULD BE HELD UP ABOVE NORMAL ONCE AGAIN BY
INCREASING CLOUD COVER.
THE UPPER TROUGH MOVES INTO WESTERN WISCONSIN LATE SATURDAY.
WHILE DEBRIS FROM ANY LEFTOVER CONVECTION WILL HAVE TO BE DEALT
WITH...AIRMASS SHOULD DESTABILIZE SUFFICIENTLY WITH PRESENCE OF
UPPER TROF TO INCREASE THUNDERSTORM THREAT AFTER 18Z. INCREASING
DEEP SHEAR AND INSTABILITY INDICATE THREAT FOR SEVERE
STORMS...THOUGH BEST CHANCE WOULD BE ACROSS SE THIRD OF WI...PER
SPC DAY 2 OUTLOOK. AS IS USUALLY THE CASE...SEVERE THREAT WILL
LARGELY HINGE ON THE TIMING OF THE SYSTEM AND THE DEGREE OF
INSTABILITY SATURDAY AFTERNOON.
TEMPS ON SATURDAY SHOULD REACH NEAR 90 ACROSS THE FOX VALLEY WITH
ANY AMOUNT OF SUNSHINE. TEMPS IN THE LOWER 80S ACROSS THE FAR N
WITH MORE CLOUDS AND PRECIP TO START THE DAY.
ALL-IN-ALL...PREVIOUS FORECAST WAS IN GOOD SHAPE SO ONLY MINOR
TWEAKING WAS NEEDED.
.LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY.
MAIN FORECAST CONCERN WILL BE THE EXITING SYSTEM SUNDAY NIGHT AND
CLOUDS/LINGERING PRECIP OVER THE NORTH SUNDAY MIDDAY.
...SATURDAY NIGHT AND SUNDAY...
COLD FRONT SHOULD BE IN THE VICINITY OF THE FOX VALLEY AROUND 00Z
SUNDAY. MODEL CONSENSUS HAS TRENDED TOWARDS THIS SLOWER
SOLUTION...SO KEPT PRECIP IN THE CWA LONGER THAN THE PREVIOUS
FORECAST. THE COLD FRONT SHOULD MOVE OUT WITH THE UPPER LEVEL
SYSTEM AND CLEAR THE AREA BETWEEN 09-12Z SUNDAY. GFS/ECMWF HAVE
BEEN THE SLOWEST AND KEEP PRECIP AROUND THE LONGEST...THEREFORE
HAVE SHOWERS CONTINUING ON THE LAKESHORE UNTIL SUNDAY MORNING.
AFTER THAT...MUCH OF THE AREA IS EXPECTED TO REMAIN DRY FOR SUNDAY.
THE ONLY EXCEPTION BEING MODELS TRENDING TOWARDS AN AREA OF
CLOUDS AND SHOWERS OVER NORTHERN WISCONSIN AROUND MIDDAY SUNDAY
AS A WEAK JET STREAK SWINGS THROUGH ON THE BACK SIDE OF THE 500MB
TROUGH. WITH MODERATELY UNSTABLE MIDLEVEL LAPSE RATES AROUND 7C AND
THE GFS/GEM PUTTING PRECIP OVER THE NORTH SUNDAY MORNING THROUGH
THE EARLY AFTERNOON...ADDED SLIGHT CHANCES OF SHOWERS OVER THIS
AREA UNTIL MIDDAY PER MODEL TRENDS. SKIES WILL CLEAR OUT BY SUNDAY
NIGHT AS HIGH PRESSURE BUILDS INTO THE AREA.
GUIDANCE HAS TRENDED COOLER SATURDAY NIGHT THROUGH SUNDAY NIGHT WITH
TEMPERATURES...SO BROUGHT MAX/MIN TEMPS DOWN A FEW DEGREES. WITH
CLEARING SKIES AND CAA IN PLACE...MIN TEMPS COULD GET RELATIVELY
COLD SUNDAY NIGHT.
...MONDAY THROUGH FRIDAY...
HIGH PRESSURE HOLDS OVER WISCONSIN THROUGH MUCH OF THE PERIOD WITH
WEAK IMPULSES MOVING THROUGH THE MEAN ZONAL FLOW. A COUPLE OF
CHANCES FOR PRECIP IN THE EXTENDED...BEGINNING WITH MONDAY NIGHT
INTO TUESDAY AS A WEAK COLD FRONT PUSHES SOUTHEAST THROUGH THE STATE.
BETTER CHANCE LOOKS TO BE THURSDAY INTO FRIDAY AS A STRONGER SHORTWAVE
SWINGS THROUGH NORTHERN WISCONSIN. TEMPERATURES SHOULD RETURN TO
NEAR NORMAL OR SLIGHTLY ABOVE NORMAL LEVELS THROUGH NEXT WEEK.
&&
.AVIATION...SUBTLE BOUNDARY LIFTING OVER CENTRAL WISCONSIN THIS
EVENING WAS PRODUCING VERY ISOLATED SHOWERS AND STORMS AT TIMES.
THE SHOWERS AND STORMS DURATION WERE RELATIVELY SHORT LIVED.
OTHERWISE DEBRIS CLOUDS AND CONVECTION FROM A CLUSTER OF SHOWERS
AND STORMS OVER THE DAKOTAS MAY WORK INTO THE WESTERN HALF OF THE
STATE OVERNIGHT. MVFR CIGS MAY WORK INTO CENTRAL AND NORTH CENTRAL
WISCONSIN OVERNIGHT.
MAIN DYNAMICS WITH DEEP SHORT WAVE TROUGH AND COLD FRONT WILL PASS
OVER THE STATE ON SATURDAY FOR A FEW ROUNDS OF SHOWERS AND
STORMS. IFR CONDITIONS CAN BE EXPECTED WITH THE STRONGER STORMS.
A FEW STORMS MAY BE SEVERE OVER CENTRAL AND NORTH CENTRAL
WISCONSIN EARLY TO MID AFTERNOON AND THEN LATER AFTERNOON AND
EVENING OVER EASTERN WISCONSIN.
TDH
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT THU AUG 2 2012
.SHORT TERM...
334 PM CDT THU AUG 2 2012
OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON
SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER
THREAT STILL LOOKING LIKE EASTERN PART OF WI.
02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX
AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW
POINT CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS
INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN
LOW-LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME
CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG RANGE.
MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION SATURDAY IS
SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND ALBERTA WITH A
TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP ANALYSIS.
CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER WY/MT/ND IN THE
DIFFLUENT FLOW AND HEIGHT FALL REGION.
WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING
ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING
ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH
CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED
CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI
MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT
DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST
ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR.
FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM
THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE
WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN
FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT
HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING
SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS
THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH
A DRY AIR MASS IN PLACE.
LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY
WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST
OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME
LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING
TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE
FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS
AFTER MIDNIGHT.
IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT
ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT
LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER
WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z
ECMWF OF A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY
TOWARD KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS
THE NAM WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR
SENSIBLE WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE
WOULD ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR
SATURDAY AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW
MORE RAIN SATURDAY EVENING IN CENTRAL WI.
EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY
LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A
SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3
SLIGHT RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE
FORECAST AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY
TSRA THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING
IN SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT
ALLOWING A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE
1800 J/KG AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES
APPEAR TO BE EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW
SWRN-CENTRAL WI TO GET INTO A WIND AND HAIL THREAT.
HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED HIGH
TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN
CHANCES A BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER
SECONDARY LOW DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS
TAKEN ABOUT A 4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE
WEATHER FOR WESTERN WI IS STILL NOT RULED OUT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
335 PM CDT THU AUG 2 2012
A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER
HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS
AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH
DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE
02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF
IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD
ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER
CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE
ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST.
THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN
THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS
MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE
WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES
WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL
THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT.
&&
.AVIATION...
600 PM CDT THU AUG 2 2012
HIGH PRESSURE OVER SOUTHEAST CANADA WILL BE THE MAIN WEATHER
INFLUENCE FOR THE REGION TONIGHT...RESULTING IN MOSTLY CLEAR SKIES
AND LIGHT SFC WINDS. ADD RAINS FROM LAST NIGHT/EARLY THIS MORNING
AND THE SETUP WOULD SEEM CONDUCIVE TO AREAS OF FOG. HOWEVER...BUFKIT
RAP/NAM12 WIND FIELDS FAVOR AROUND 10 KTS WITHIN THE FIRST COUPLE
HUNDRED FEET TONIGHT...AN INHIBITOR TO WIDESPREAD FOG. AFTERNOON
SUNSHINE HAS ALSO LED TO A QUICK BUMP UPWARD IN THE TEMPS...AND
MIXING RESULTING IN DRYING OF THE SFC TD. LARGER T/TD SPREAD TO
OVERCOME TONIGHT AS A RESULT. WILL STAY WITH 5SM BR MENTION IN TAFS
FOR NOW AND MONITOR TRENDS THROUGH THE EVENING. THINK THE GREATER
THREAT FOR SUB 1SM WOULD LIE IN THE RIVER VALLEYS...AND THUS AT
KLSE.
VFR CONDITIONS SHOULD ABOUND FOR MOST OF FRIDAY...WITH SOME
INCREASING CLOUDS FROM THE WEST IN THE EVENING...AHEAD OF AN
APPROACHING COLD FRONT. THIS FRONT WILL BRING SOME SHRA/TS
CHANCES...MOSTLY AFTER 12Z SAT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
335 PM CDT THU AUG 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM....BAUMGARDT
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
354 PM CDT THU AUG 2 2012
.SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE IS MEDIUM.
AREA OF RAIN SHOWERS CONTINUES TO SHIFT EAST ACROSS THE NORTHERN
COUNTIES OF THE FORECAST AREA. THIS AREA AIDED BY MODEST 850MB/700MB
MOISTURE POOLING/CONVERGENCE AND LOW LEVEL FRONTOGENESIS RESPONSE.
THIS AREA SHOULD CONTINUE TO SHIFT EASTWARD THROUGH THE REST OF THE
AFTERNOON ACROSS THE NORTHEAST COUNTIES...ALONG WITH ASSOCIATED
UPWARD VERTICAL MOTION.
WEAK COLD FRONT FROM WEST CENTRAL TO NORTHEAST WISCONSIN IS EXPECTED
TO SAG SOUTHWARD THROUGH THE AREA THIS EVENING...THEN TO THE SOUTH
LATER TONIGHT. AREA OF WEAK TO MODEST 850MB CONFLUENCE ALSO SHIFTS
SOUTH INTO THE AREA AND LINGERS THROUGH THE NIGHT. AREA FORECAST
SOUNDINGS SHOWING CAP MIXING OUT ACROSS SOUTHERN PORTIONS OF THE
AREA WHERE CLOUDS MOVED AWAY...WITH AROUND 500 J/KG MEAN LAYER CAPE.
CLOUDIER AREAS WOULD HAVE LESS CAPE AND MORE CAPPING.
CAPE BECOMES MORE ELEVATED TONIGHT AND WOULD HAVE TO BE REACHED BY
ELEVATED PARCELS. HRRR MODEL SHOWING WIDELY SCATTERED CELLS AT BEST
DEVELOPING LATE THIS AFTERNOON INTO THE EARLY EVENING. KEPT POPS FOR
LATE THIS AFTERNOON INTO TONIGHT WITH THE ABOVE FORCING MECHANISMS
MOVING IN. A GOOD PORTION OF THE AREA LIKELY WILL BE DRY.
SCATTERED MID LEVEL CLOUDS EXPECTED TONIGHT INTO FRIDAY. DRIER AIR
WORKS INTO THE AREA FRIDAY ON EASTERLY WINDS. KEPT DRY FORECAST
GOING FOR FRIDAY WITH DECENT CAP ACROSS THE AREA. LOWS TONIGHT
SHOULD FALL TO THE MID TO UPPER 60S...WITH ANOTHER VERY WARM DAY IN
THE UPPER 80S TO LOWER 90S AWAY FROM THE LAKE. EAST WINDS KEEPS
HIGHS COOLER NEAR LAKESHORE.
FRIDAY NIGHT THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
A FAIRLY SHARP UPPER TROUGH WILL TRACK EWD FROM THE NRN HIGH
PLAINS THROUGH THE GREAT LAKES DURING THIS PERIOD WITH AN
ORGANIZED LOW PRESSURE AREA MOVING ALONG THE US/CANADIAN BORDER.
THETAE ADVECTION WILL BOOST PWS TO NEARLY ONE INCH FOR SAT
AFTERNOON AND EVENING AHEAD OF AND ALONG THE COLD FRONT ALONG WITH
MODERATE INSTABILITY AND WIND SHEAR. THUNDERSTORMS WILL LIKELY
DEVELOP SAT AFTERNOON OVER WRN WI AND THEN MOVE EWD THROUGH SAT
EVENING. A SLIGHT RISK OF SEVERE THUNDERSTORMS IS FORECAST BY SPC
AND LOOKS GOOD. COLD AND DRY ADVECTION WILL THEN PREVAIL ON SUNDAY
WITH A PLEASANT DAY FOLLOWED BY HIGH PRESSURE THROUGH MON NT.
.LONG TERM...
SRN WI WILL BE ON THE SRN PERIPHERY OF NW FLOW WITH ONLY A WEAK
COOL FRONT TO POSSIBLY BE IN THE VICINITY OF SRN WI FROM TUE-WED.
THUS ONLY SLIGHT CHANCE OF TSTORMS DURING THAT TIME. TEMPS WILL BE
AT LEAST SLIGHTLY ABOVE NORMAL NEXT WEEK.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS EXPECTED THROUGH FRIDAY ACROSS TAF SITES. CURRENT
SHOWER ACTIVITY WILL CONTINUE TO REMAIN NORTH OF TAF SITES. EXPECT
SCATTERED TO BROKEN MID LEVEL CLOUDS THROUGH THE LATE AFTERNOON.
EAST/SOUTHEAST WINDS ARE EXPECTED TO LINGER AT MILWAUKEE AND REACH
WAUKESHA BY 22Z. LIGHT WINDS ARE EXPECTED TO LINGER AT MADISON.
WEAK COLD FRONT SLIDING SOUTH TOWARD THE AREA LATE THIS
AFTERNOON...AND THROUGH THE AREA THIS EVENING. FRONT WOULD BRING
MAINLY SMALL CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE
EVENING...AND A SHOWER AFTER MIDNIGHT. HOWEVER...TOO MUCH
UNCERTAINTY RIGHT NOW TO MENTION IN TAFS.
LIGHT EAST TO NORTHEAST WINDS TONIGHT SHOULD REMAIN EASTERLY ON
FRIDAY ACROSS TAF SITES...WITH FEW TO SCATTERED MID LEVEL CLOUDS.
EASTERLY WINDS BRING DRIER AIR INTO THE AREA LATER TONIGHT AND
FRIDAY...WITH QUIET WEATHER EXPECTED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TONIGHT/FRIDAY AND AVIATION/MARINE...WOOD
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
335 PM CDT THU AUG 2 2012
.SHORT TERM...
334 PM CDT THU AUG 2 2012
OVERALL NOT MANY CHANGES TO THE ONGOING FORECAST. SIGHTS ARE ON
SATURDAY SYSTEM MOVING THROUGH THE REGION WITH SEVERE WEATHER
THREAT STILL LOOKING LIKE EASTERN PART OF WI.
02.12Z RAOB DATA SUGGESTS THE TAIL OF TWO AIR MASSES BETWEEN KMPX
AND KDVN. KDVN IS REMARKABLY DRY AND THIS IS LEADING TO THE DEW POINT
CRASHES INTO THE 50S SEEN NEAR KDBQ AND SOUTH AS MIXING HAS
INCREASED THIS AFTERNOON. STILL A WEAKLY CONVERGENCE FLOW IN LOW-
LEVELS ALONG AN INVERTED TROUGH FROM NEAR KDLL-KOVS-KMCW. SOME
CUMULUS LOOKING MORE ENHANCED...WITH MLCAPE IN THE 1500 J/KG
RANGE. MORE SIGNIFICANT TROUGH EXPECTED TO AFFECT THE REGION
SATURDAY IS SEEN IN GOES WATER VAPOR OVER BRITISH COLUMBIA AND
ALBERTA WITH A TROPOPAUSE LEVEL DOWN TO 500 MB PER THE 02.19Z RAP
ANALYSIS. CONVECTION ALREADY BECOMING ACTIVE DOWNSTREAM OVER
WY/MT/ND IN THE DIFFLUENT FLOW AND HEIGHT FALL REGION.
WITH SUCH WEAK CONVERGENCE AND MID-UPPER LEVEL SUPPORT THIS EVENING
ACROSS NE IA AND SWRN WI...HAVE DECIDED TO KEEP IT DRY THIS EVENING
ACROSS THE SOUTH. LATEST HRRR RUNS ARE SLIGHTLY LIGHTER WITH
CONVECTIVE CELL DEVELOPMENT DOWN THERE...MORE TOWARD AN ENHANCED
CUMULUS SOLUTION. HRRR SUGGESTS THE INVERTED TROUGH OVER ERN WI
MORE VIGOROUS IN EVENING. THERE COULD BE A STORM OR TWO THAT
DEVELOP BUT WE DO NOT SEE IT AS ENOUGH TO ADD IT TO THE FORECAST
ACROSS OUR FORECAST AREA. EVENING FORECASTER CAN MONITOR.
FRIDAY APPEARS TO BE A NICE DAY WITH THE RIDGE BUILDING IN FROM
THE GREAT LAKES AND SE FLOW IN THE LOW-LEVELS. WILL NEED TO BE
WATCHING THE SYSTEM TO THE SOUTH WHICH IS CUTOFF FROM THE MAIN
FLOW AND HAS SOME CAPE BUILDING ACROSS IL AND MOISTURE TRANSPORT
HAS SOME SIGNAL OF CONVERGENCE ACROSS NORTHERN IL. THIS MAY BRING
SOME SHRA ACTIVITY NEAR SOUTHERN WI AND THE FORECAST AREA. IDEA IS
THAT DEWPOINTS ARE PROBABLY OVERFORECAST IN THE GUIDANCE WITH SUCH
A DRY AIR MASS IN PLACE.
LARGER SCALE TROUGH MOVING EAST INTO THE NORTHERN PLAINS ON FRIDAY
WILL INITIATE CONVECTION IN THE DAKOTAS THAT WILL ROLL EAST
OVERNIGHT ON MOISTURE TRANSPORT AND DYNAMICS. STILL HAVE SOME
LIMITED CAPE TO THE WEST OVERNIGHT TO SUGGEST A DECAYING
TSRA/SHRA ACROSS MN/IA POSSIBLY AFFECTING SERN MN/WRN MN LATE
FRIDAY NIGHT. HAVE INCREASED RAIN CHANCES A BIT FOR THOSE AREAS
AFTER MIDNIGHT.
IN THE BIG PICTURE...THE 02.12Z NAM/GEM/GFS/ECMWF ARE IN AGREEMENT
ON THE TIMING OF THE LARGER SCALE TROUGH MOVING ACROSS THE GREAT
LAKES SATURDAY AND SATURDAY NIGHT. THE DETAILS ARE DIFFERENT HOWEVER
WITH THE 02.12Z NAM SUGGESTING A SIMILAR IDEA AS THE 02.00Z/12Z ECMWF OF
A SECONDARY SURFACE LOW MOVING NE ALONG THE FRONT SATURDAY TOWARD
KMKE FROM IL. THE EC SOLUTIONS ARENT QUITE AS AGGRESSIVE AS THE NAM
WITH THE STRENGTH OF THE SECOND LOW...BUT THEY HAVE SIMILAR SENSIBLE
WEATHER OUTCOMES BUT LESS RAINFALL. THIS LOW SHIFTING NE WOULD
ELICIT A GREATER CHANCE OF RAIN EAST OF THE MISS RIVER FOR SATURDAY
AND SLOW THE EASTWARD MOVING COLD FRONT AND DRYING TO ALLOW MORE
RAIN SATURDAY EVENING IN CENTRAL WI.
EVEN WITH THESE DIFFERENCE IN THE DEVELOPMENT OF A SECONDARY
LOW...THE CONSENSUS CAPE IS MAINLY EAST OF THE FORECAST AREA FOR A
SATURDAY SEVERE WEATHER THREAT. THIS AGREES WITH THE SPC DAY 3 SLIGHT
RISK FOR EASTERN WI. ANALYSIS OF THE SOUNDINGS OVER THE FORECAST
AREA SUGGEST THAT ELEVATED INSTABILITY IS REALLY THE ONLY TSRA
THREAT WITH THE LOWEST CIN VALUES AROUND 100 J/KG LATE MORNING IN
SWRN WI PER 02.12Z NAM. 02.12Z GFS A BIT SLOWER WITH FRONT ALLOWING
A BIT MORE WARMING AND INSTABILITY...WITH ML CAPE IN THE 1800 J/KG
AREA AND CIN NEAR 50 J/KG. SO...THE MAIN THREAT DOES APPEAR TO BE
EAST. BUT...ANY SLOWING TO THE FRONT WOULD ALLOW SWRN-CENTRAL WI TO
GET INTO A WIND AND HAIL THREAT.
HAVE INCREASED RAIN CHANCES FOR SATURDAY A BIT MORE AND LOWERED
HIGH TEMPERATURES BY 3-5F WITH MORE CLOUD. ALSO HAVE INCREASED RAIN CHANCES A
BIT WESTWARD SATURDAY EVENING TO ALLOW FOR A SLOWER SECONDARY LOW
DEVELOPMENT ALONG THE FRONT. THE 02.12Z ECMWF HAS TAKEN ABOUT A
4-6 HOUR STEP SLOWER THAN THE PREVIOUS RUN...SO SEVERE WEATHER FOR
WESTERN WI IS STILL NOT RULED OUT.
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY
335 PM CDT THU AUG 2 2012
A DRIER PERIOD IS SEEN HERE AS THE LARGE SCALE TROUGH DEEPENS OVER
HUDSONS BAY AND IMPACTS THE WESTERN GREAT LAKES WITH LOWER HEIGHTS
AND NORTHWEST FLOW. 02.12Z ECMWF IS MORE AGGRESSIVE WITH THE TROUGH
DEPTH OVER THE AREA SUGGESTING A BIT COOLER THAN THE 02.12Z GFS. THE
02.12Z GEM WOULD AGREE MORE ON THE GFS SIDE...HOWEVER IT MAY BE OFF
IN ITS TIMING AS IT HAS A DEEPER SHORTWAVE TROUGH ROTATING SOUTHWARD
ABOUT 24 HOURS AFTER THE 02.12Z ECMWF SOLUTION. IN EITHER
CASE...THE SENSIBLE WEATHER IS MAINLY A COOLER FORECAST IN THE
ECMWF. THUS...HAVE TAKEN A FEW DEGREES OFF A CONSENSUS FORECAST.
THE 02.00Z GFS ENSEMBLE DATA DID SHOW HIGHER SIGNS OF SPREAD IN
THE MID-WEEK HIGHS WITH A 78-87F RANGE...AND THE OPERATIONAL GFS
MOS WAS ON THE WARM SIDE. STILL THINK THE 02.12Z GFS IS ON THE
WARM SIDE AND HAVE UNDERCUT THOSE VALUES. FORECAST TEMPERATURES
WILL BE PLEASANT AND NEAR NORMAL. PRECIPITATION CHANCES ARE SMALL
THROUGH THE WEEK AND HARD TO TIME OUT AT THIS POINT.
&&
.AVIATION...THROUGH 18Z FRIDAY
1232 PM CDT THU AUG 2 2012
COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT
NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS
WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH
SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING
AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT
RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE
FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS
WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE
SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING
HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE
FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR
BETWEEN 07Z-14Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
335 PM CDT THU AUG 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1232 PM CDT THU AUG 2 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
359 AM CDT THU AUG 2 2012
AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED
NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE
EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST
WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE
02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE
TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE
SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT
OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND
NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST
ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN
ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A
WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE
LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS
WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH
WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A
700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS
HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE.
AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW
THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS.
FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE
FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG
THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE
THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE
NMM AND ARW ALSO SUPPORT THIS TOO.
FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING
SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA.
THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF
THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD
SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND
SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST
THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO
THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES
BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT
CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED
EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO
WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS
ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS
SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING
A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL
PASSAGE.
.LONG TERM...SUNDAY THROUGH THURSDAY
359 AM CDT THU AUG 2 2012
ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA
AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE
THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE
FORECAST AREA.
FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY
WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES.
BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER
ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT
WERE PRODUCED IN THE ALL BLEND.
&&
.AVIATION...THROUGH 18Z FRIDAY
1232 PM CDT THU AUG 2 2012
COLD FRONT WILL PUSH THROUGH THE TAF SITES BY 18Z...WITH A LIGHT
NORTHWEST WIND IN ITS WAKE. EXTENSIVE LAYER OF MID LEVEL CLOUDS
WILL AFFECT BOTH SITES THROUGH MUCH OF THE AFTERNOON...WITH
SCATTERED TO BROKEN CONDITIONS. CLOUDS WILL CLEAR OUT THIS EVENING
AND REMAIN CLEAR THROUGH 18Z FRIDAY. WITH THE OVERNIGHT
RAIN...THERE IS SOME CONCERN FOR FOG TONIGHT. THE BIGGEST NEGATIVE
FOR FOG FORMATION WILL BE WINDS. THE 02.12Z NAM SUGGEST WINDS
WILL REMAIN IN THE 10 TO 15 KNOT RANGE LATE TONIGHT JUST ABOVE THE
SURFACE. WILL HAVE TO MONITOR THIS CLOSE THROUGH THE EVENING
HOURS AND IF THE WINDS LOOK TO BE LIGHTER WILL HAVE TO ADD MORE
FOG TO THE TAFS. FOR THE 18Z TAFS WILL CONTINUE TO MENTION 5SM BR
BETWEEN 07Z-14Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
359 AM CDT THU AUG 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...RABERDING
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
628 AM CDT THU AUG 2 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
359 AM CDT THU AUG 2 2012
AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED
NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE
EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST
WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE
02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE
TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE
SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT
OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND
NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST
ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN
ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A
WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE
LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS
WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH
WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A
700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS
HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE.
AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW
THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS.
FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE
FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG
THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE
THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE
NMM AND ARW ALSO SUPPORT THIS TOO.
FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING
SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA.
THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF
THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD
SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND
SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST
THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO
THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES
BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT
CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED
EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO
WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS
ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS
SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING
A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL
PASSAGE.
.LONG TERM...SUNDAY THROUGH THURSDAY
359 AM CDT THU AUG 2 2012
ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA
AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE
THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE
FORECAST AREA.
FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY
WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES.
BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER
ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT
WERE PRODUCED IN THE ALL BLEND.
&&
.AVIATION...TODAY AND TONIGHT
628 AM CDT THU AUG 2 2012
FORECAST CONCERNS ARE FOCUSED ON NEAR-TERM PRECIPITATION
CHANCES...THEN FOG POTENTIAL OVERNIGHT. SURFACE ANALYSIS SHOWS
FRONTAL BOUNDARY LINGERING ACROSS SOUTHERN MINNESOTA INTO WESTERN
WISCONSIN...WITH A SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS
MOVING THROUGH. CONFIDENCE IS HIGH THAT THESE SHOWERS/STORMS WILL
WEAKEN AND MOVE SOUTHEAST OF KRST/KLSE BY MID TO LATE MORNING AS
FRONT FINALLY PUSHES THROUGH. BROKEN MID LEVEL CLOUDS WILL
GRADUALLY ERODE BY LATE AFTERNOON AS HIGH PRESSURE BUILDS ACROSS
NORTHERN MINNESOTA/WISCONSIN.
NEXT CONCERN IS OVERNIGHT FOG POTENTIAL. GIVEN RECENT RAINFALL
ACROSS THE AREA...COOLER AIR TEMPERATURES...AND BUILDING HIGH
PRESSURE...WOULD EXPECT AT LEAST SOME PATCHY FOG TO DEVELOP.
CONFIDENCE IS NOT HIGH ENOUGH HOWEVER TO INTRODUCE IFR OR LOWER
CONDITIONS AS SUGGESTED BY SOME FORECAST MODEL GUIDANCE. WINDS IN
THE LOWEST LEVELS COULD BE HIGH ENOUGH TO KEEP BOUNDARY LAYER
MIXED SO FOR NOW HAVE INCLUDED A MVFR VISIBILITY AND LATER
FORECASTS CAN EVALUATE POTENTIAL.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
359 AM CDT THU AUG 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ZT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
400 AM CDT THU AUG 2 2012
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT
359 AM CDT THU AUG 2 2012
AT 3 AM...THE CLUSTER OF SHOWERS AND THUNDERSTORMS...THAT MOVED
NORTH OF THE INTERSTATE 90 CORRIDOR FROM LAST EVENING INTO THE
EARLY OVERNIGHT...WAS LOCATED ACROSS EAST-CENTRAL AND NORTHEAST
WISCONSIN. THIS WAS ASSOCIATED WITH A 700 TO 500 MB TROUGH. THE
02.00Z MODELS ARE IN GOOD AGREEMENT THAT THIS SYSTEM WILL CONTINUE
TO MOVE EAST AWAY FROM THE REGION THIS MORNING. FURTHER TO THE
SOUTHWEST ANOTHER SHORT WAVE TROUGH WAS AIDING IN THE DEVELOPMENT
OF A MESOSCALE CONVECTIVE COMPLEX ACROSS EASTERN NEBRASKA AND
NORTHERN KANSAS. THIS SYSTEM IS FORECAST TO CONTINUE TO MOVE EAST
ACROSS SOUTHERN IOWA AND MISSOURI THIS MORNING...AND SOUTHERN
ILLINOIS THIS AFTERNOON. IN BETWEEN THESE TWO WAVES...THERE IS A
WEAK COLD FRONT EXTENDING FROM MENOMINEE TO CHARLES CITY IOWA. THE
LATEST RAP CONTINUES TO SHOW THAT THE 900 TO 600 MB FRONTOGENESIS
WILL SLOWLY WEAKEN THIS MORNING. THIS FRONTOGENESIS ALONG WITH
WEAK MOISTURE CONVERGENCE WILL AID IN THE IN THE DEVELOPMENT OF
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS MORNING. A
700 MB SPEED MAXIMUM MOVING THROUGH THE REGION EARLY THIS MORNING IS
HELPING TO ENHANCE THE 0-3 KM SHEAR INTO THE 35 TO 40 KNOT RANGE.
AS A RESULT...THERE IS A POSSIBILITY THAT WE COULD HAVE A FEW
THUNDERSTORMS BECOME SEVERE THROUGH 9 AM THIS MORNING. THE MAIN
THREATS WILL BE LARGE HAIL AND DAMAGING WINDS.
FOR THIS AFTERNOON...THE WINDS ARE GENERALLY PARALLEL WITH THE
FRONT. AS A RESULT...THERE IS LITTLE MOISTURE CONVERGENCE ALONG
THIS BOUNDARY. AS A RESULT...NOT SOLD ON THE IDEA THAT WE WILL SEE
THE REDEVELOPMENT OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON. THE
NMM AND ARW ALSO SUPPORT THIS TOO.
FROM FRIDAY NIGHT INTO SATURDAY NIGHT...THE MODELS ARE TRENDING
SLOWER WITH THE COLD FRONTAL PASSAGE THROUGH THE FORECAST AREA.
THE NAM/WRF IS THE FASTEST AND IT SHOWS THE FRONT THROUGH MUCH OF
THE AREA BY NOON SATURDAY. MEANWHILE THE ECMWF AND GFS WOULD
SUGGEST THAT THE COLD FRONT WILL MOVE INTO NORTHEAST IOWA AND
SOUTHEAST MINNESOTA ON SATURDAY MORNING...AND THEN MOVE EAST
THROUGH THE REMAINDER OF THE AREA EARLY SATURDAY AFTERNOON. DUE TO
THIS SLOWER FRONTAL MOVEMENT...DELAYED THE PRECIPITATION CHANCES
BY ABOUT 12 TO 18 HOURS. THE 0-3 KM ML CAPES AHEAD OF THIS FRONT
CLIMB INTO THE 2 TO 3K RANGE. MEANWHILE THE BEST SHEAR IS LOCATED
EITHER ON THE FRONT OR POST FRONTAL. AS RESULT...WILL HAVE TO
WATCH FOR THE POTENTIAL OF A FEW THUNDERSTORMS BECOMING SUPERCELLS
ALONG THE FRONT. AT THIS TIME...THE BEST CHANCE LOOKS TO BE ACROSS
SOUTHERN AND EASTERN WISCONSIN. THIS IS DUE TO THESE AREAS HAVING
A LONGER TIME TO BUILD UP INSTABILITY PRIOR TO THE FRONTAL
PASSAGE.
.LONG TERM...SUNDAY THROUGH THURSDAY
359 AM CDT THU AUG 2 2012
ON SUNDAY...A COLD POOL WILL MOVE EAST ACROSS NORTHEAST MINNESOTA
AND NORTHERN WISCONSIN. THERE WILL BE LIKELY SOME SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS ASSOCIATED WITH IT...BUT LIKE
THE PAST COUPLE OF DAYS IT LOOKS LIKE THEY WILL BE NORTH OF THE
FORECAST AREA.
FROM SUNDAY NIGHT INTO TUESDAY...HIGH PRESSURE WILL PROVIDE DRY
WEATHER AND SLIGHTLY ABOVE-NORMAL TEMPERATURES.
BEYOND THIS TIME FRAME...THE GFS AND ECMWF DIFFER ON WHETHER
ANOTHER CANADIAN COLD FRONT WILL MOVE SOUTHEAST THROUGH THE
REGION. WITH THESE DIFFERENCES JUST KEPT THE SLIGHT CHANCES THAT
WERE PRODUCED IN THE ALL BLEND.
&&
.AVIATION...
1115 PM CDT WED AUG 1 2012
A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE
FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU
MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND
GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY
THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED.
DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN
COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR
FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK
OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS...
DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT
LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING
DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU
AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
359 AM CDT THU AUG 2 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1150 PM CDT WED AUG 1 2012
.AVIATION/06Z TAFS/...
OUTFLOW DRIVEN THUNDERSTORMS NORTH OF LA CROSSE EXPECTED TO WEAKEN
AS THEY MOVE EAST...AND WILL REMAIN WELL NORTH OF TAF SITES
OVERNIGHT. CHANCE OF THUNDER THURSDAY AFTERNOON ON NOSE OF 850
WARM AIR ADVECTION AND FRONTOGENETIC FORCING WITH WEAK COLD FRONT...BUT
VERY DRY BELOW 10K FT SO CONFIDENCE LOW. WILL MENTION VCNTY FOR
NOW. BOUNDARY LAYER IS STILL STIRRED SO NO FOG FORECAST BUT NEEDS
TO BE WATCHED ESPECIALLY AT KENW. OTHERWISE VFR CONDITIONS
EXPECTED THROUGH FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 325 PM CDT WED AUG 1 2012/
VERY SHORT TERM...TONIGHT AND THURSDAY.
CURRENT ELEVATED CONVECTION ACROSS NORTHERN WISCONSIN ASSOCIATED
WITH LOW LEVEL WARM AIR ADVECTION AND NOSE OF 30 KNOT PLUS WESTERLY
LOW LEVEL JET. THIS CONVECTION SHOULD SHIFT SOUTHEAST TOWARD CENTRAL
TO EAST CENTRAL WISCONSIN BUT WEAKEN...AS CAPPED AIRMASS LINGERS IN
SOUTHERN WISCONSIN. THIS IS SUPPORTED BY 16Z RUN OF HRRR MODEL. MAY
SEE SOME LEFTOVER DEBRIS CLOUDS MOVE THROUGH THE AREA LATER THIS
AFTERNOON INTO THE EARLY EVENING. WILL GO DRY FOR NOW IN THE FAR
NORTHERN COUNTIES THROUGH THE REST OF THE DAY.
SURFACE COLD FRONT SHIFTS SOUTHEAST TOWARD THE AREA TONIGHT...THEN
SLOWLY SOUTHWARD THROUGH THE AREA ON THURSDAY. WARM AIR ADVECTION
CONTINUES AHEAD OF THE FRONT TONIGHT...WITH THE RIGHT REAR QUADRANT
OF A 250MB JET STREAK PUSHING THROUGH LATER TONIGHT INTO THURSDAY
MORNING.
AREA FORECAST SOUNDINGS FROM NAM AND RAP SHOWING CAP FOR SURFACE
BASED PARCELS TONIGHT AND THURSDAY...WITH MODEST ELEVATED CAPES
AROUND 500 J/KG. LOW LEVELS REMAIN DRY...WITH SOME MID LEVEL
MOISTURE MOVING INTO THE AREA LATER TONIGHT INTO THURSDAY. HRRR
MODEL TRIES TO DEVELOP AN AREA OF CONVECTION IN SOUTHERN MINNESOTA
ALONG COLD FRONT AND BRING IT TOWARD THE WESTERN COUNTIES AFTER
MIDNIGHT TONIGHT.
FOR NOW...WILL BRING IN CHANCE POPS FROM NORTHWEST TO SOUTHEAST
TONIGHT. LINGERED CHANCE POPS THURSDAY MORNING IN THE NORTHERN
COUNTIES...LOWER TO THE SOUTH...WITH LOWER END POPS DURING THE
AFTERNOON.
TEMPERATURES WILL BE TRICKY DEPENDING ON HOW MUCH MID LEVEL
CLOUDINESS DEVELOPS/MOVES THROUGH THE AREA. WENT SOMEWHAT LOWER THAN
WARM 925MB TEMPERATURES FROM NAM...UPPER 60S TONIGHT WITH UPPER 80S
TO LOWER 90S THURSDAY. LAKE BREEZE IN THE AFTERNOON
SHORT TERM...THURSDAY NIGHT THROUGH SATURDAY.
WEAK Q-VECTOR CONVERGENCE AND FRONTEGENETICAL FORCING MAY RESULT IN
A FEW SHOWERS OR THUNDERSTORMS LINGERING INTO THURSDAY EVENING OVER
THE NORTHERN AREAS. BOTH ECMWF AND NAM SHOW THIS WEAK FORCING...BUT
WILL BE LIMITED BY DRYING MID LEVELS. SLIGHTLY BETTER FORCING
FARTHER NORTH...SO WL ONLY GO WITH SCHC POPS FOR NOW.
LOW LEVEL MIXING SHOULD PREVENT SIGNIFICANT FOG LATER THURSDAY
NIGHT. SHORT WAVE RIDGING AHEAD OF NEXT WEATHER SYSTEM IS EXPECTED
TO BRING A PLEASANT DAY FOR FRIDAY...WITH UNSETTLED CONDITIONS
FOCUSED TO THE SOUTH AND WEST OF WI.
SHORT TERM GUIDANCE IN SURPRISINGLY GOOD AGREEMENT ON MORE VIGOROUS
SHORT WAVE TROF MOVING ACROSS SOUTHERN CANADA AND THE WESTERN
GTLAKES FRIDAY NIGHT THROUGH SATURDAY NIGHT. ASSOCIATED LOW
PRESSURE WILL DRAG A COLD FRONT ACROSS SOUTHERN WI AND LAKE MICHIGAN
DURING PEAK HEATING OF THE AFTN AND EVE. WITH SFC DEWPTS LIKELY TO
BE IN THE MID 60S TO LOW 70S...SFC BASED CAPE VALUES MAY CLIMB TO
ABV 3000 J/KG. BULK SHEAR WILL BE STRONG ENOUGH...IN THE 25 TO 40KT
RANGE. LOW LEVEL JETS REMAIN FOCUSED FARTHER SOUTH ALONG WARM FRONT
AND NORTH...CLOSER TO LOW PRESSURE. HENCE WL KEEP POPS IN HIGH
CHANCE CATEGORY INTO SAT NGT...AND MENTION POSSIBILITY OF SEVERE IN
HAZARDOUS WEATHER OUTLOOK.
LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY.
VIGOROUS SHORT WAVE TROUGH AND COLD FRONT PUSH EAST OF WISCONSIN
SATURDAY NIGHT...USHERING COOLER AND DRY CONDITIONS INTO THE REGION
FOR SUNDAY AND MONDAY. GFS ENSEMBLES IN FAIRLY GOOD AGREEMENT ON
THIS SCENARIO.
EXTENDED OUTLOOK TURNS MORE MURKY HEADING INTO MID-WEEK AS BOTH
ECMWF AND GFS HAVE BEEN FLIP-FLOPPING ON UPPER LEVEL STEERING FLOW.
LATEST SOLUTIONS HAVE TRENDED TOWARD MORE PROGRESSIVE WEST-NORTHWEST
STEERING FLOW FOR THE LATER HALF OF THE PERIOD. UKMT...GFS AND
ECMWF SOLUTIONS CARRY WEAK FRONTAL BOUNDARY THROUGH WI SOMETIME IN
THE MON NGT/TUESDAY TIME FRAME...WITH FRONT POSSIBLY BECOMING
STATIONARY ACROSS THE REGION...BUT CONFIDENCE LOW AS EXTENDED
GUIDANCE HAVING ISSUES WITH TIMING AND STRENGTH OF SHORT WAVE
TROFFING MOVING INTO WESTERN CONUS. AFTER COOLER...MORE SEASONAL
PERIOD ON SUNDAY AND MONDAY...85H TEMPS WARM BACK TO AROUND 20C.
GFS 5DAY ANOMOLIES SHOW RIDGING AND WARMER TEMPERATURES EXPANDING
BACK INTO THE UPPER MIDWEST LATER NEXT WEEK AHEAD OF LONG WAVE
TROUGH AMPLIFICATION IN THE EASTERN PAC/NORTHWEST CONUS.
AVIATION /00Z TAFS/...VFR CONDITIONS EXPECTED THROUGH THURSDAY
ACROSS TAF SITES. FEW TO SCATTERED DIURNAL CUMULUS AT EASTERN TAF
SITES SHOULD DISSIPATE BY SUNSET. LIGHT SOUTH TO SOUTHWEST WINDS
EXPECTED AT MADISON DURING THIS TIME...WITH LIGHT SOUTHEAST WINDS
EVENTUALLY REACHING MILWAUKEE AND KENOSHA BY 22Z TO 23Z WEDNESDAY.
SOME MID LEVEL CLOUDS FROM STORMS TO THE NORTH MAY SHIFT THROUGH TAF
SITES LATE THIS AFTERNOON AND EARLY THIS EVENING.
SCATTERED TO BROKEN MIDDLE TO HIGH CLOUDS SHOULD GRADUALLY MOVE INTO
THE AREA LATER TONIGHT AND THURSDAY. COLD FRONT WILL SHIFT SOUTHEAST
TOWARD TAF SITES LATE TONIGHT...THEN SLIDES SOUTHWARD THROUGH TAF
SITES THURSDAY. MAY SEE SHOWERS AND STORMS APPROACH MADISON BETWEEN
06Z AND 12Z THURSDAY...AND ACROSS ALL SITES THURSDAY. HOWEVER...WILL
HOLD OFF MENTION IN TAFS FOR NOW DUE TO LOW CONFIDENCE IN AREAL
COVERAGE AND TIMING.
LIGHT WINDS WILL SHIFT TO THE NORTHEAST/EAST IN THE WAKE OF THE COLD
FRONT IN THE LATE MORNING AND EARLY AFTERNOON THURSDAY.
CONFIDENCE...
TONIGHT AND THURSDAY...MEDIUM
THURSDAY NIGHT...LOW TO MEDIUM.
FRIDAY AND FRIDAY NIGHT...MEDIUM.
SATURDAY AND SATURDAY NIGHT...MEDIUM.
SUNDAY AND MONDAY...MEDIUM TO HIGH.
TUESDAY AND WEDNESDAY...LOW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...REM
TONIGHT/THURSDAY AND AVIATION/MARINE...WOOD
THURSDAY NIGHT THROUGH WEDNESDAY...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1115 PM CDT WED AUG 1 2012
.SHORT TERM...TONIGHT
615 PM CDT WED AUG 1 2012
WATCHING EVOLUTION OF THUNDERSTORMS ASSOCIATED WITH ELEVATED
INSTABILITY AND SFC FRONT/ELEVATED FRONTOGENETIC FORCING ACROSS
SOUTHWEST MN. THIS WEST-EAST RUNNING BOUNDARY WILL HOVER ACROSS
SOUTHEAST MN-WESTERN WI OVERNIGHT...STAYING A FOCUS FOR SHOWER/STORM
DEVELOPMENT. MAIN CONCERN THOUGH IS THE SEVERE POTENTIAL THIS
EVENING. STRONG INSTABILITY WITH MLCAPES NEAR 4K J/KG OVER SOUTHERN
MN PER RAP ANALYSIS AT 22Z. SHEAR ISN/T TOO IMPRESSIVE...BUT
ABOUT 20-25 KTS EFFECTIVE SHEAR. THE INSTABILITY WOULD SUPPORT
STRONG UPDRAFTS AND A LARGE HAIL THREAT. PERHAPS MORE SIGNIFICANTLY
IS THE DEEP DRY SUB CLOUD LAYER. BUFKIT SOUNDINGS CONTINUE TO
INDICATE THIS...WITH DCAPES OVER 1500 J/KG PROGGED FOR THE FORECAST
AREA THIS EVENING. THIS ENHANCES THE DAMAGING WIND THREAT. ANY
STRONG STORM WOULD BE CAPABLE OF PRODUCING 40 MPH GUSTS...OBVIOUSLY
MORE WITH A SEVERE STORM. SEVERE THUNDERSTORM WATCH BUTTING UP
AGAINST THE WESTERN FORECAST AREA...AND IF STORMS CONTINUE TO
EVOLVE...WOULD EXPECT ANOTHER WATCH FOR SOUTHEAST MN INTO WESTERN
WISCONSIN BY MID EVENING.
.LONG TERM...SUNDAY THROUGH WEDNESDAY
309 PM CDT WED AUG 1 2012
MEDIUM RANGE MODEL RUNS OF 01.00Z IN RATHER GOOD AGREEMENT WITH THE
TROUGH MOVING EAST OF THE REGION AND WEAK SHORTWAVE RIDGING BUILDING
INTO THE UPPER MIDWEST. MODELS STAY IN PRETTY GOOD AGREEMENT MON-WED
AS THE SHORTWAVE RIDGING QUICKLY MOVES EAST OF THE AREA MON AND THE
NEXT AND THE NEXT STRONGER TROUGH MOVES ACROSS SOUTHERN CAN/NORTHERN
CONUS...INTO THE UPPER MIDWEST TUE/WED. SOME DIFFERENCE OF TIMING/
STRENGTH DETAILS OF SHORTWAVES IN THE FLOW BY TUE/WED BUT THIS TO BE
EXPECTED. BETWEEN MODEL CONSISTENCY GOOD BUT RUN-TO-RUN CONSISTENCY
LESS THAN DESIRABLE...ESPECIALLY BY TUE/WED. LONG-TERM FCST
CONFIDENCE GOOD SUN THEN AVERAGE MON-WED UNTIL THE DETAIL CONSENSUS
IMPROVES. WITH THE TROUGH/LOW EXITING EAST...DRIER/COOLER CAN HIGH
PRESSURE SETTLES ACROSS THE REGION FOR SUN/MON. TEMPS LOOKING TO BE
BELOW NORMAL SUN...THEN ALREADY MODERATE ON MON AS THE CENTER OF THE
HIGH MOVES EAST AND SOUTHERLY FLOW RETURNS. MID LEVEL TROUGH MOVING
EAST ALONG THE US/CAN BORDER TUE/WED DRAGS A SFC TROUGH/FRONT INTO/
ACROSS THE AREA TUE. AGAIN TIMING/DETAIL DIFFERENCES ON MOISTURE/
INSTABILITY AND FORCING/LIFT BY TUE. BOUNDARY LOOKS TO STALL IN THE
REGION WED WITH STRENGTHENING LOW PRESSURE IN THE CENTRAL/NORTHERN
PLAINS AS MORE SHORTWAVE ENERGY COMES THRU THE ROCKIES OR DROPS INTO
THE NORTHERN PLAINS. SMALL SHRA/TSRA CHANCES TUE/WED LOOK
REASONABLE AT THIS POINT. WITH CONTINUED SOUTHERLY/INCREASING
MOISTURE...TEMPS CLIMB BACK TO ABOVE NORMAL FOR TUE/WED. MODEL
CONSENSUS DATA SET IN FCST GRIDS FOR DAYS 4-7 HAVE THIS WELL
TRENDED.
&&
.AVIATION...
1115 PM CDT WED AUG 1 2012
A WEST-EAST RUNNING FRONTAL BOUNDARY WILL CONTINUE TO SERVE AS THE
FOCUS FOR SHRA/TS DEVELOPMENT OVERNIGHT...PERSISTING INTO THU
MORNING. THERE IS STILL A SMALL THREAT FOR STRONG TO DAMAGING WIND
GUSTS IN THE VICINITY OF ANY STORM THROUGH ABOUT 2 AM...BUT MOSTLY
THIS POTENTIAL HAS LESSENED AS THE NEAR SFC STABILITY HAS INCREASED.
DO EXPECT PERIODS OF SHRA/TS OVERNIGHT. THE SEVERAL HOURS OF RAIN
COULD RESULT IN THE LOWERING OF CLOUD BASES...BUT WILL KEEP TAFS VFR
FOR NOW. EXPECT THE RAIN TO EXIT EAST BY THE AFTERNOON. SHOULD BREAK
OUT OF BKN MID LEVEL CIGS BY MID/LATE AFTERNOON. FOR WINDS...
DIRECTION COULD BE HIGHLY VARIABLE AND RELATIVELY LIGHT AS THE FRONT
LAYS ACROSS KRST/KLSE. THIS MAKES PINNING DOWN A PREVAILING
DIRECTION A BIT DIFFICULT UNTIL THE FRONT SAGS SOUTH LATER THU
AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
309 PM CDT WED AUG 1 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RIECK
LONG TERM....RRS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MIAMI FL
358 AM EDT SAT AUG 4 2012
...LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
...MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
.DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
&&
.MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
&&
.FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/GREGORIA
AVIATION/RADAR...15/JR
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
143 AM EDT SAT AUG 4 2012
.PREV DISCUSSION... /ISSUED 1013 PM EDT FRI AUG 3 2012/
UPDATE...
SCATTERED TO ISOLATED THUNDERSTORM DEVELOPMENT HAS BEEN PERSISTENT
OVER PORTIONS OF CENTRAL AND EASTERN GA WITH LITTLE TO NO ACTIVITY
ACROSS THE NW PORTION. THE RECENT HRRR RUNS HAVE BEEN PICKING UP
BETTER ON THE CONVECTION AND MAINTAINS THE DEVELOPMENT WELL INTO
THE OVERNIGHT. HAVE ADJUSTED TO HAVE CHANCE POPS IN THESE AREAS
THROUGH THE OVERNIGHT WHILE DECREASING THE NW AND SE PORTIONS TO
SLIGHT CHANCES FROM 06-12Z. ALL ELSE SEEMS TO BE ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...
03
PREV DISCUSSION... /ISSUED 303 PM EDT FRI AUG 3 2012/
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
CURRENT RADAR LOOP SHOWS SHOWERS MOVING INTO THE AREA FROM THE NW.
ISOLATED THUNDERSTORMS SHOULD START MOVING INTO THE AREA AS SOON AS
THINGS DESTABILIZE A BIT MORE THIS AFTERNOON. THE BIGGEST THREAT
STILL APPEARS TO BE ISOLATED AREAS OF FLOODING AS PW VALUES ARE IN
THE 2 TO 2.20 INCH RANGE THROUGH 00Z SUN. CAPES ARE IN THE 1500 TO
2000 J/KG RANGE WITH LIS NEAR -3 TO -4 THIS AFTERNOON. THE
INSTABILITIES DROP OFF VERY QUICKLY AFTER SUNSET BUT THE PWS
CONTINUE TO STAY UP. THE SHORTWAVE MOVING SE OUT OF MIDDLE TN WILL
PUSH INTO NW GA LATTER TONIGHT AND STALL ACROSS N AND W GA THROUGH
00Z SUN. IT WILL STAY THERE BEFORE BEGINNING TO MAKE ITS WAY BACK
NORTHWARD AS THE BERMUDA LIKE RIDGE BEGINS TO BUILD IN FROM THE
ATLANTIC SAT/SUN. WILL CONTINUE WITH LIKELY POPS THIS AFTERNOON
AND TONIGHT WITH CHANCE POPS SAT/SAT NIGHT. TEMPS WILL STAY NEAR
OR SLIGHTLY BELOW SEASONAL NORMS DUE TO THE PRECIP AND CLOUD
COVER EXPECTED.
01
LONG TERM /SUNDAY THROUGH FRIDAY/...
DESPITE SLIGHT TIMING DIFFERENCES...MODELS ARE STILL IN FAIRLY GOOD
AGREEMENT WITH A COLD FRONT MOVING INTO NORTH GEORGIA ON MONDAY AND
SINKING INTO CENTRAL GEORGIA ON TUESDAY. BASED ON CONSISTENCY OF
MODELS WITH AFFECTS FROM FRONT EXPECTED ACROSS THE CWA MONDAY AND
TUESDAY...HAVE INCREASED POPS CLOSER TO THE HIGHER END OF CHANCE.
DIFFERENCES IN GFS AND ECMWF BECOME MORE APPARENT INTO MIDWEEK. 12Z
GFS WANTS TO LINGER THE FRONT ACROSS THE CWA THROUGH THE LONG TERM
WHILE THE 00Z ECMWF SLIDES THE BOUNDARY SOUTH OF THE AREA. WITH IT
BEING SUMMER HAVE TRENDED TOWARD LOW END CHANCE POPS...CLOSER TO
THE GFS SOLUTION. WITH LINGERING BOUNDARY SUGGESTED THOUGH BY THE
GFS...POPS MAY BE A LITTLE ON THE LOW SIDE.
11
&&
.AVIATION...
06Z UPDATE...
CONVECTION IN EASTERN ZONES WILL CONTINUE TO WEAKEN THROUGH THE
EARLY MORNING. EXPECT THAT MOST SITES WILL SEE IFR CIGS...POSSIBLY
LIFR...AROUND 12Z. CIGS WILL LIFT THROUGH MID-MORNING. EXPECT A
SIMILAR CONVECTIVE PATTERN TO FRIDAY...WITH PEAK ACTIVITY AROUND
00Z. WINDS GENERALLY SOUTHEAST THROUGH THE PERIOD...LIGHT
OVERNIGHT AND BETWEEN 5-10KT DURING THE DAY EXCEPT IN
THUNDERSTORMS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM ON MOST ELEMENTS...INCLUDING TIMING OF CONVECTION AND
DEVELOPMENT OF IFR CIGS.
LOW ON POTENTIAL LIFR CIG DEVELOPMENT.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 87 70 89 72 / 60 60 30 20
ATLANTA 89 72 91 74 / 60 60 30 20
BLAIRSVILLE 80 69 85 68 / 60 60 40 30
CARTERSVILLE 88 71 90 69 / 60 50 40 30
COLUMBUS 90 72 91 74 / 50 50 40 20
GAINESVILLE 85 71 87 72 / 60 60 30 30
MACON 93 72 91 73 / 40 40 40 20
ROME 88 71 90 71 / 50 50 40 30
PEACHTREE CITY 88 69 89 70 / 60 60 30 20
VIDALIA 93 74 92 75 / 30 30 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1208 AM CDT SAT AUG 4 2012
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
FOCUS THROUGHOUT THE SHORT/MID RANGE WILL BE ON SYSTEM MOVING
THROUGH THE REGION TONIGHT THROUGH SATURDAY NIGHT...AND ASSOCIATED
COLD FRONT DROPPING THROUGH THE STATE. INITIALLY LINGERING ACTIVITY
FROM EARLIER TODAY TO THE NORTHWEST HAS JUST DIMINISHED IN THE PAST
FEW HOURS ACROSS NORTHWEST IOWA ASSOCIATED WITH SOME WEAK ENERGY
ALOFT PUSHING OUT AHEAD OF THE MAIN WAVE. HRRR ADVERTISES SOME
REDEVELOPMENT ACROSS THE NORTH CENTRAL CWA WITH THIS ENERGY...AND
HAVE A FEW WEAK CELLS POPPING JUST TO THE NE OF THE CWA. ALSO HAVE
DECENT CU FIELD EXTENDING BACK INTO THE CWA...WITH ANOTHER CU FIELD
SITUATED ACROSS THE EXTREME SOUTHERN CWA NORTH OF ONGOING MCS THAT
HAS BEEN IN PLACE ACROSS MO ALL DAY. THEREFORE HAVE SOME SLIGHT
CHANCE POPS IN THE NORTH AND SOUTH THROUGH THE REMAINDER OF THE
AFTERNOON HOURS WITH SPC MESODATA SUGGESTING SUFFICIENT INSTABILITY
IN PLACE AND DECENT SHEAR ACROSS THE NORTH. THEREFORE AN ISOLATED
SEVERE STORM CANNOT BE RULED EITHER ACROSS THE NORTH WITH ANY
ACTIVITY THAT MAY DEVELOP. OTHERWISE GREATER CHANCE FOR
PRECIPITATION/CONVECTION LATER TONIGHT AS STORMS CONTINUE TO DEVELOP
IN VICINITY OF THE SFC FRONT SITUATED ACROSS CENTRAL SD INTO CENTRAL
NE. AS THE MAIN UPPER WAVE PUSHES EAST ACROSS THE DAKOTAS AND INTO
MINNESOTA SATURDAY...ASSOCIATED COLD FRONT WILL SWEEP ACROSS THE
STATE...WITH SHOWERS AND THUNDERSTORMS EXPECTED TO BE ONGOING ACROSS
THE NORTHWESTERN CWA SATURDAY MORNING AND CONTINUING TO TRACK
EASTWARD SLOWLY DIMINISHING WITH TIME. FRONT WILL THEN PUSH INTO THE
EASTERN CWA IN THE AFTERNOON HOURS...WITH REDEVELOPMENT EXPECTED BY
LATE AFTERNOON ALONG THE FRONT...WITH THE FRONT EXITING THE CWA BY
EARLY TO LATE EVENING AS THE UPPER SYSTEM TRACKS INTO THE GREAT
LAKES REGION. THEREFORE HAVE GREATEST POPS FOR SATURDAY ACROSS THE
CWA...WITH BEST CHANCE OF WIDER SPREAD PRECIPITATION AS THE AREA HAS
SEEN IN A FEW WEEKS. MUCH COOLER AIR MOVING IN BEHIND THE
FRONT...WITH H85 TEMPS DROPPING INTO THE LOWER TEENS TO MID TEENS
CELSIUS ALOFT. THEREFORE MAX TEMPS TO BE COOLER IN AREAS BEHIND THE
FRONT SATURDAY...WITH MANY SITES NOT MAKING IT OUT OF THE 70S ACROSS
NORTHWESTERN IOWA AND MUCH COOLER CONDITIONS ACROSS THE ENTIRE STATE
FOR SUNDAY. HIGHS SUNDAY EXPECTED TO TOP OUT IN THE 70S NORTH TO MID
80S SOUTH...WITH A QUICK CHANGE TO RETURN FLOW MONDAY AND MID 80S TO
90S WITH DRY CONDITIONS SUNDAY INTO MONDAY. ANOTHER WEAK SHORTWAVE
DROPS DOWN THROUGH THE REGION MONDAY NIGHT IN NORTHWEST FLOW PATTERN
ALOFT. THEREFORE COULD SEE A CHANCE FOR SOME NOCTURNAL THUNDERSTORMS
MONDAY NIGHT ACROSS MUCH OF THE CWA.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
BOTH GFS AND EURO NOW INDICATE BROAD NORTHWEST FLOW INTO NEXT WEEK
AS UPPER RIDGING RETROGRADES INTO THE ROCKIES. THIS SHOULD DO A
COUPLE OF THIS FOR IOWA...FIRST TEMPERATURES WILL LIKELY REMAIN
COOLER DURING THE NEXT WEEK THAN WHAT PREVIOUS FORECASTS HAD GOING.
READINGS ARE EXPECTED TO BE CLOSE TO NORMAL OR SLIGHTLY ABOVE BUT
NOT THE 10 TO 15 DEGREE DEPARTURES WE SAW DURING MUCH OF JULY.
SECOND...THE THREAT OF PRECIPITATION SHOULD BE GREATER AS WEAK
SHORTWAVES IN THE FLOW DROP INTO THE MIDWEST. THE MAIN PROBLEM WITH
THESE IS MORE OF A TIMING ISSUE AS IS OFTEN TYPICAL IN NORTHWEST
FLOW. THESE CONDITIONS WILL CERTAINLY PROVIDE SOME RELIEF FROM THE
INTENSIFYING DROUGHT WITH BOTH MODELS INDICATING THE NORTHWEST FLOW
CONTINUING BEYOND THE FORECAST PERIOD.
&&
.AVIATION...04/06Z
CDFNT ENTERING NWRN IA WILL MOVE TO NEAR CENTRAL IA BY SHORTLY AFTER
SUNRISE...AND PASS SOUTHEAST OF THE TAF SITES BY EARLY SAT
AFTERNOON. LOW PRESSURE WAVE WILL TRAVEL NORTHEAST ALONG THE
FRONT. SCATTERED TSRA WILL ACCOMPANY THE FRONT AND ALSO WILL
DEVELOP NORTH OF THE FRONTAL BOUNDARY AS THE SURFACE WAVE LIFTS
NEWD. HAVE CARRIED A FEW HOURS OF TSRA AROUND THE FRONT AND SHOWERS
AFTER THE FRONT. THINKING IS THAT CONDITIONS WILL REMAIN VFR.
CLEARING WILL SPREAD SOUTH ACROSS THE STATE LATE SAT AFTERNOON AND
EVENING WITH LIGHT NWLY WINDS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MS AUG 12
LONG TERM...COGIL
AVIATION...MS AUG 12
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
354 AM CDT SAT AUG 4 2012
...LONG TERM SECTION UPDATED AT 355 AM...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM CDT SAT AUG 4 2012
THIS MORNING:
SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE
TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH
THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES
FROM THE NW.
TODAY:
MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE
REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T
THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD
OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND
BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT
OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND
ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS
SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP
LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF
OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE
THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES
GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST
CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL
ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A
250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN
COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND
ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC
PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY
DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS
FOR THE REST OF TODAY.
TONIGHT:
THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY
OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED
ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850
HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION.
WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL
NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE
FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY
ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT
WITH VALUES IN THE 50S AND 60S DEG F.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 353 AM CDT SAT AUG 4 2012
TROPICAL THUNDERSTORMS CONTINUE TO BE VERY ACTIVE NORTH OF THE
EQUATOR FROM NEAR 120E TO 170E, AND A TROPICAL CYCLONE IS EVIDENT ON
SATELLITE IMAGERY SOUTH OF JAPAN. THE INDIAN OCEAN HAS BEEN FAIRLY
QUIET IN RECENT DAYS. IT DOES APPEAR THAT A COHERENT FEATURE IS
PROPAGATING RAPIDLY EASTWARD INTO THE WESTERN HEMISPHERE AND WILL
REACH THE WESTERN INDIAN OCEAN AGAIN BY MID AUGUST. ATMOSPHERIC
RELATIVE ANGULAR MOMENTUM CONTINUES TO BE SLIGHTLY ABOVE
CLIMATOLOGICAL VALUES, AND MOUNTAIN TORQUE HAS BECOME POSITIVE
RECENTLY. ALTHOUGH THE SIGNAL IS VERY WEAK, THE ATMOSPHERE MAY BE
HEADED TOWARD PHASE 5 OF THE WEICKMANN/BERRY GLOBAL WIND OSCILLATION
PHASE SPACE DIAGRAM. IF THIS OCCURS, ANTICYCLONIC FLOW WILL BE
FAVORED ON THE WESTERN UNITED STATES WITH A TENDENCY TOWARD
TROUGHING IN THE EAST BY MID AUGUST. MOST OF THE NUMERICAL MODELS
ARE SUGGESTING THIS TREND. THE ECMWF IS MORE AGGRESSIVE IN WEAKENING
THE UPPER LEVEL RIDGING IN THE CENTRAL PART OF THE COUNTRY THAN THE
GFS, AND MOST OF THE GEM ENSEMBLE MEMBERS MAINTAIN MORE RIDGING THAN
THE ECMWF DETERMINISTIC SOLUTION. GIVEN THE HOT, DRY CONDITIONS IN
THE CENTRAL AND SOUTHERN PLAINS AND IMPROBABILITY OF WIDESPREAD
BENEFICIAL RAINFALL, THE GFS SOLUTION SEEMS MORE REASONABLE.
THE UPPER LEVEL ANTICYCLONE CENTERED OVER SOUTHERN OKLAHOMA AND
NORTHERN TEXAS WILL WEAKEN AND RETROGRADE TO NEAR 110W BY MONDAY,
AND TROUGHING WILL AMPLIFY IN THE EASTERN UNITED STATES. THE PLUME
OF SUBTROPICAL MOISTURE EXTENDING FROM WESTERN MEXICO TO THE CENTRAL
PLAINS WILL DROP SOUTHWARD TO NEAR THE KANSAS/OKLAHOMA BORDER BY
SUNDAY MORNING, AND A FEW HIGH BASED SHOWERS MAY BE IN PROGRESS
UNDER THE TROPICAL PLUME SUNDAY MORNING. A WEAK UPPER LEVEL TROUGH
EVIDENT ON SATELLITE IMAGERY IN NORTHERN ARIZONA WILL APPROACH THE
CENTRAL PLAINS LATE SATURDAY NIGHT AND MAY ENHANCE SHOWER AND
THUNDERSTORMS UNDER THE TROPICAL PLUME ALONG AND NORTH OF THE
FRONTAL BOUNDARY IN THE SOUTHERN PLAINS. THE PLUME OF SUBTROPICAL
MOISTURE WILL CONTINUE TO DROP SOUTHWARD AS FLOW OVER THE CENTRAL
PLAINS BECOMES MORE NORTHWEST ON SUNDAY. THERE IS A MARGINAL CHANCE
THAT THUNDERSTORMS IN SOUTHEASTERN COLORADO COULD CLIP THE SOUTHWEST
CORNER OF KANSAS AS THEY PROPAGATE SOUTHEAST DURING THE EVENING
HOURS SUNDAY, BUT CONFIDENCE IS NOT HIGH ENOUGH TO INTRODUCE POPS
YET. TEMPERATURES SUNDAY SHOULD BE NEAR SEASONAL AVERAGES.
VERY WARM AIR WILL SPREAD BACK INTO WESTERN KANSAS ON MONDAY AS
ANOTHER UPPER LEVEL TROUGH DIGS TOWARD THE GREAT LAKES AND LOW LEVEL
FLOW BECOMES MORE SOUTHWEST. TEMPERATURES MONDAY SHOULD RETURN TO
NEAR 100 DEGREES ACROSS WESTERN KANSAS. A WEAK UPPER LEVEL TROUGH
ROTATING AROUND THE WESTERN UNITED STATES ANTICYCLONE WILL APPROACH
THE CENTRAL PLAINS BY TUESDAY MORNING. WEAK SYNOPTIC SCALE LIFTING
MAY BE SUFFICIENT TO SUPPORT A FEW THUNDERSTORMS IN CENTRAL KANSAS
LATE MONDAY NIGHT INTO EARLY TUESDAY, BUT CONFIDENCE IS NOT HIGH.
ANOTHER UPPER LEVEL TROUGH ORIGINATING IN THE TROPICAL PACIFIC WILL
MOVE OVER THE UPPER LEVEL RIDGE AND APPROACH KANSAS ON WEDNESDAY,
AND THUNDERSTORM CHANCES WILL CONTINUE THROUGH THE DAY WEDNESDAY
WITH THE BEST OPPORTUNITY IN CENTRAL AND EASTERN KANSAS.
UPPER LEVEL HIGH PRESSURE WILL BUILD BACK INTO KANSAS THURSDAY
THROUGH SATURDAY, AND MORE TEMPERATURES IN EXCESS OF 100 DEGREES CAN
BE EXPECTED. THE NEXT POSSIBILITY OF RAINFALL WILL BE AROUND 12
AUGUST WHEN ANOTHER UPPER LEVEL TROUGH DIGS INTO THE UPPER MIDWEST
AND SUPPORTS PROGRESSION OF A COLD FRONT INTO KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 62 93 64 / 20 10 0 0
GCK 83 62 92 65 / 20 10 0 0
EHA 84 65 88 68 / 20 10 10 10
LBL 87 65 90 66 / 20 10 10 10
HYS 85 58 93 63 / 20 10 0 0
P28 99 67 95 66 / 20 20 10 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...RUTHI
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
245 AM CDT SAT AUG 4 2012
...UPDATE TO SHORT TERM DISCUSSION...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 245 AM CDT SAT AUG 4 2012
THIS MORNING:
SHOWERS AND ISOLATED THUNDERSTORMS ACTIVITY LAST NIGHT WILL CONTINUE
TO WEAKEN SIGNIFICANTLY OVERNIGHT. WILL GRADUALLY TAPER POPS THROUGH
THIS MORNING BUT KEEP ISOLATED IN THE GRIDS AS A COLD FRONT SLOWLY APPROACHES
FROM THE NW.
TODAY:
MUCH COOLER WEATHER IS EXPECTED TODAY AS A COLD FRONT MOVES ACROSS THE
REGION. 850 HPA WINDS ARE FORECAST TO BE IN THE 20-30 KT RANGE SO DON`T
THINK SURFACE WINDS WILL BE AT WIND ADVISORY CRITERIA FOR A LONG PERIOD
OF TIME. THERE COULD BE SOME ISALLOBARIC FORCING IMMEDIATELY ALONG AND
BEHIND THE FRONT SO WINDS MAY REACH CRITERIA JUST FOR A SHORT AMOUNT
OF TIME. DID USE THE MIXED LAYER WIND TOOL AND WILL HIGHLIGHT SUB WIND
ADVISORY CRITERIA IN THE HWO (MAINLY 20 TO 30 MPH). FORECAST SOUNDINGS
SHOW QUITE A BIT OF MID TO UPPER LEVEL (500-300 HPA) MOISTURE SO WILL KEEP
LINGERING CLOUD COVER IN THE GRIDS (PARTICULARLY FOR THE FIRST HALF
OF TODAY). USED MOSGUIDANCEBC AFTER CHECKING BOISE VERIFICATION TO SEE
THAT THIS OUTPUT IS PERFORMING BETTER THAN THE NAM. A LARGE TEMPERATURES
GRADIENT IS EXPECTED ACROSS THE REGION WITH LOWER 80S DEG F ACROSS WEST
CENTRAL KANSAS TO AROUND 100 DEG F ACROSS SOUTH CENTRAL KANSAS. WILL
ALSO KEEP SLIGHT POPS GOING TODAY AS THE RIGHT ENTRANCE REGION OF A
250 HPA JET STREAK SAGS SOUTHWARD CLOSER TO SOUTHWEST KANSAS. THIS IN
COMBINATION WITH WEAK ISENTROPIC LIFT COULD LEAD TO A FEW SHOWERS AND
ISOLATED THUNDERSTORMS TODAY. NOT REALLY IMPRESSED WITH THE THERMODYNAMIC
PROFILE IN THE SURFACE TO 700 HPA LAYER AS THIS STRATUM LOOKS FAIRLY
DRY SO DON`T THINK WE WILL SEE ANY SIGNIFICANT PRECIPITATION AMOUNTS
FOR THE REST OF TODAY.
TONIGHT:
THE WRF-ARW AND TO A LESSER EXTENT THE NAM ARE INDICATING THE POSSIBILITY
OF LATE NIGHT CONVECTION ALONG THE FRONT AFTER 00Z TONIGHT. THE AFOREMENTIONED
ENTRANCE REGION WILL BE EVEN CLOSER AND ALSO WITH A STRENGTHENING 850
HPA LOW LEVEL JET MAY PROVIDE ENOUGH DYNAMICS AND LIFT FOR MORE CONVECTION.
WILL INCREASE POPS LATE TONIGHT ACROSS SOUTH CENTRAL KANSAS BUT WILL
NOT GET CARRIED AWAY AS CONFIDENCE IS FAIRLY LOW AS THE NAM HAS THE
FRONT FARTHER SOUTH INTO OKLAHOMA IN WHICH OUR REGION MAY NOT SEE ANY
ADDITIONAL PRECIPITATION. LOWS HEADING INTO SUNDAY WILL BE PLEASANT
WITH VALUES IN THE 50S AND 60S DEG F.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CDT FRI AUG 3 2012
ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM
SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL
MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY
SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST
NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS.
UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH
SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH
CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER
BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY.
GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS
EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION
HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST.
ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN
AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE
CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB
TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN
TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO
SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS
FORECAST STILL LOOKS ON TRACK.
ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID
MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH
I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST
KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL
YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD
COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING
PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING
TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE
SUGGESTS.
ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG
THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A
4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE
MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY
FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS
TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT
REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS.
BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR
CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL
ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK
SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY
NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE
DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE
ALONG THE NORTHWEST FLOW AND ACROSS KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 86 62 91 70 / 20 10 10 10
GCK 83 62 90 69 / 20 10 10 10
EHA 84 65 90 69 / 20 10 10 10
LBL 87 65 91 70 / 20 10 10 10
HYS 85 58 91 69 / 20 10 0 10
P28 99 67 94 71 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...SUGDEN
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT SAT AUG 4 2012
...UPDATE TO AVIATION FOR 06Z TAFS...
.SYNOPSIS...
ISSUED AT 1035 PM CDT FRI AUG 3 2012
THE 04.00Z 250 HPA SYNOPTIC MAP SHOWED CYCLONIC FLOW ACROSS THE NORTHERN
HIGH PLAINS AND ACROSS THE CANADIAN PRAIRIES. A JET STREAK OF 75 KT
WAS OBSERVED AT KRIV (RIVERTON, WY). ANOTHER STRONGER JET STREAK OF
90 KT WAS OBSERVED ACROSS CENTRAL QUEBEC. AT 500 HPA, A 565 DM CYCLONE
WAS LOCATED ACROSS NW NORTH DAKOTA AND EXTENDING NORTHWARD INTO SASKATCHEWAN.
COLD AIR ADVECTION WAS OCCURRING UPSTREAM ACROSS MONTANA WEST OF THIS
LOW WITH VALUES AROUND -18 DEG C. ANOTHER ITEM OF INTEREST AT 500 HPA
WAS A LARGE 593 DM ANTICYCLONE LOCATED ACROSS THE STATE OF TEXAS. WARM
MID LEVEL TEMPERATURES AROUND -3 DEG C WERE ASSOCIATED WITH THIS FEATURE.
AT 700 HPA, TEMPERATURES ACROSS THE SOUTHERN AND CENTRAL PLAINS WERE
STILL WARM WITH VALUES IN THE 14 TO 17 DEG C RANGE. THIS ATMOSPHERE
WAS FAIRLY DRY AS WELL. FURTHER NORTH, COLD AIR AIR ADVECTION WAS OCCURRING
IN THE WAKE OF THE AFOREMENTIONED MID LEVEL DISTURBANCE WITH 700 HPA
TEMPERATURES AS LOW AS -2 DEG C ACROSS KGGW (GLASGOW, MT). AT 850 HPA,
THERE WAS AN IMPRESSIVE TEMPERATURE GRADIENT ACROSS THE PLAINS WITH
9 DEG C AT KGGW (GLASGOW, MT) TO A VERY WARM VALUE OF 34 DEG C AT KAMA
(AMARILLO, TX). AT THE SURFACE, A LOW PRESSURE SYSTEM WAS LOCATED ACROSS
SOUTHEASTERN MANITOBA WITH A COLD FRONT EXTENDING SOUTHWARD TO NEBRASKA.
TROPICAL STORM ERNESTO WAS LOCATED NEAR 13.9N 65.6W AT 04.03Z.
&&
.SHORT TERM...(THIS EVENING THROUGH TOMORROW)
ISSUED AT 352 PM CDT FRI AUG 3 2012
A NEARLY STATIONARY FRONT EXTENDED FROM SOUTHEAST KANSAS INTO THE
TEXAS PANHANDLE THIS AFTERNOON. LOW LEVEL MOISTURE WAS "POOLING"
NORTH OF THE FRONT OVER SOUTHWEST KANSAS WITH DEWPOINTS IN THE
UPPER 50S TO LOWER 60S, LEADING TO SURFACE BASED CAPE FROM
1000-1500 J/KG. A SHORTWAVE TROUGH WAS PROGRESSING ACROSS THE
NORTHERN ROCKIES TODAY AND WILL MOVE ACROSS THE NORTHERN PLAINS ON
SUNDAY. THIS FEATURE WILL HELP DRAG A COLD FRONT THROUGH SOUTHWEST
KANSAS SATURDAY MORNING. THE WARM FRONT WILL MOVE NORTHWARD
TONIGHT INTO SOUTHWEST KANSAS. A FEW THUNDERSTORMS MAY DEVELOP
NEAR AND NORTH OF THE WARM FRONT THIS AFTERNOON AND PROPAGATE
NORTHWARD AND EASTWARD THIS EVENING INTO KANSAS. ALSO, SURFACE
BASED CONVECTIVE INITIATION COULD OCCUR ACROSS SOUTHEAST COLORADO
THIS EVENING AND THEN PROGRESS INTO SOUTHWEST KANSAS PER NAM/HRRR.
GIVEN THE AFOREMENTIONED CAPE AND INCREASING HIGH LEVEL WINDS TO
40-45KTS, THESE STORMS ARE CAPABLE OF HAIL AS LARGE AS QUARTERS
AND WINDS ARE HIGH AS 60 MPH.
DECIDED TO CARRY THE HIGHEST POPS IN FAR SOUTHWEST KANSAS THIS
EVENING. ADDITIONAL ELEVATED THUNDERSTORMS COULD DEVELOP LATER
TONIGHT FURTHER NORTHEAST AND POSSIBLY INTO THE FIRST HALF OF THE
DAY SATURDAY. THE PREVIOUS TEMPERATURE FORECAST WAS IN GOOD SHAPE
FOR TONIGHT AND FRIDAY. SOME CLOUD COVER SHOULD KEEP TEMPERATURES
FROM FALLING TOO MUCH TONIGHT, ALTHOUGH THE WINDS COULD GO LIGHT
AROUND 12Z AHEAD OF THE FRONT WHICH WOULD PROMOTE RADIATIONAL COOLING.
WINDS SHOULD BE JUST SHY OF ADVISORY CRITERIA FOR FRIDAY BEHIND
THE COLD FRONT. TEMPERATURES WILL RISE INTO THE MID TO UPPER 80S
FOR MOST OF SOUTHWEST KANSAS, EXCEPT FOR 95 TO 101 IN SOUTH
CENTRAL KANSAS INCLUDING BARBER, PRATT AND COMANCHE COUNTIES WHERE
THE FRONT WILL NOT ARRIVE UNTIL 2-3 PM.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 227 PM CDT FRI AUG 3 2012
ON SATURDAY EVENING THE COLD FRONT IS FORECAST TO EXTEND FROM
SOUTH CENTRAL KANSAS INTO THE PANHANDLE OF TEXAS. THIS FRONT WILL
MOVE A LITTLE FURTHER SOUTH BEFORE BECOMING STATIONARY BY EARLY
SUNDAY MORNING. A WEDGE OF HIGHER DEWPOINTS WILL BE LOCATED JUST
NORTH OF THIS FRONT ALONG WITH IMPROVING 850-700MB FRONTOGENESIS.
UPPER LEVEL JET DYNAMICS ALONG WITH THE TIMING OF THE 500MB TROUGH
SUGGESTS THE BETTER UPPER FORCING WILL BE LOCATED NEAR SOUTH
CENTRAL KANSAS. FURTHER WEST WEAKER LIFT WILL BE PRESENT, HOWEVER
BETTER LOW LEVEL MOISTURE AND UPSLOPE FLOW IS EXPECTED LATE DAY.
GIVEN THE BETTER LIFT AND INSTABILITY ACROSS SOUTH CENTRAL KANSAS
EARLY SUNDAY EVENING WILL FOCUS THE HIGHER CHANCES OF PRECIPITATION
HERE WHILE LOWER CHANCES FURTHER WEST AND NORTHWEST.
ON SUNDAY AN UPPER LEVEL RIDGE WILL BUILD INTO THE ROCKIES AS AN
AREA OF HIGH PRESSURE AT THE SURFACE MOVES SOUTHEAST ACROSS THE
CENTRAL PLAINS. SKIES ARE EXPECTED TO BE MOSTLY SUNNY WITH 850MB
TEMPERATURES AT 00Z MONDAY RANGING FROM THE LOW TO MID 20S. MIXDOWN
TEMPERATURES FROM THE NAM, MEAN SREF, AND ECMWF CONTINUE TO
SUGGEST HIGHS MAINLY IN THE LOW TO MID 90S SO THE PREVIOUS
FORECAST STILL LOOKS ON TRACK.
ON SUNDAY NIGHT THE SURFACE HIGH WILL MOVE EAST INTO THE MID
MISSISSIPPI VALLEY AND 850MB WARM AIR ADVECTION ALONG WITH
I310-I315 ISENTROPIC LIFT STARTS TO IMPROVE ACROSS SOUTHWEST
KANSAS. MOISTURE MAY BE SOMEWHAT LIMITED, DEPENDING ON WHICH MODEL
YOU PREFER. AT THIS TIME GIVEN IMPROVING LIFT WILL INCREASE CLOUD
COVER BUT STILL AM LEANING TOWARD HOLDING OFF MENTIONING
PRECIPITATION. INCREASING CLOUDS WILL HOWEVER AID IN KEEPING
TEMPERATURES UP A FEW DEGREES COMPARED TO WHAT THE LATEST GUIDANCE
SUGGESTS.
ON MONDAY AND TUESDAY A TROUGH OF LOW PRESSURE WILL DEEPEN ALONG
THE LEE OF THE ROCKIES AS 850-700MB TEMPERATURES BEGIN WARM. A
4-6C 24HOUR 850MB TEMPERATURE WARM UP IS FORECAST BY ALL THE
MODELS BETWEEN 00Z MONDAY AND 00Z TUESDAY. TEMPERATURES THEN VARY
FROM 1 TO 3C BETWEEN 00Z TUESDAY AND 00Z WEDNESDAY. GIVEN THIS
TREND SEE LITTLE REASON TO DISAGREE WITH TEMPERATURES NOT
REBOUNDING BACK INTO THE MID 90S TO AROUND 100 DEGREES BOTH DAYS.
BY MID WEEK THE UPPER LEVEL RIDGE AXIS WILL EXTEND FROM THE FOUR
CORNERS REGION INTO SOUTHWEST CANADA. UPPER LEVEL DISTURBANCES WILL
ROTATE AROUND THIS UPPER RIDGE AND DOWN THE NORTHWEST FLOW. A WEAK
SURFACE BOUNDARY IS FORECAST TO MOVE INTO WESTERN KANSAS TUESDAY
NIGHT/WEDNESDAY AND MAY PROVIDE THE FOCUS FOR SOME LATE
DAY/OVERNIGHT THUNDERSTORMS AS ANY ONE OF THESE UPPER WAVES MOVE
ALONG THE NORTHWEST FLOW AND ACROSS KANSAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1200 AM CDT SAT AUG 4 2012
TWO FORECAST CONCERNS FOR THE 06Z TAFS. HRRR INDICATING MORE SHOWER
DEVELOPMENT AHEAD OF COLD FRONT THROUGH THE OVERNIGHT HOURS. DON`T HAVE
THE HIGHEST CONFIDENCE ON THIS BUT GIVEN CURRENT RADAR TRENDS, CANNOT
COMPLETELY DISMISS IT EITHER. WILL KEEP -SHRA IN THE TAFS THROUGH 10Z.
NEXT CONCERN IS WINDS. MESOHIGH WILL CONTINUE BREEZY S/SW WINDS THROUGH
THE OVERNIGHT. A COLD FRONT WILL PASS THROUGH TOMORROW MORNING WITH
A CONTINUATION OF WINDS EXCEPT FROM THE NW/N. MAGNITUDES 22-25 KT WITH
GUSTS OF 30-35 KT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 87 61 91 / 80 20 10 10
GCK 71 86 59 90 / 60 20 10 10
EHA 70 86 61 90 / 80 20 20 10
LBL 71 88 62 91 / 80 20 20 10
HYS 71 86 58 91 / 20 20 0 0
P28 76 99 68 94 / 80 20 20 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...SUGDEN
SHORT TERM...FINCH
LONG TERM...BURGERT
AVIATION...SUGDEN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1246 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A COLD FRONT WILL CROSS THE AREA THIS EVENING AND MOST OFF THE
COAST OVERNIGHT. HIGH PRESSURE WILL BUILD ACROSS THE REGION FOR
SATURDAY INTO SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
1245 AM UPDATE...NO SIGNIFICANT CHANGES NEEDED FOR THIS UPDATE.
ONLY MADE MINOR TWEAKS TO TREND TOWARD CURRENT CONDITIONS.
PREV DISCUSSION...
CHALLENGES WILL ARE CONVECTION THIS AFTERNOON INTO THE EVENING AND
HOW STRONG AND HOW EXTENSIVE WILL THE FOG BE.
TSTMS FIRING ACROSS NORTHERN AND CENTRAL AREAS ATTM AHEAD OF THE
APCHG COLD FRONT. STILL EXPECTING CONVECTION TO FIRE UP ACROSS
PORTIONS OF THE CENTRAL HIGHLANDS AND DOWNEAST REGIONS LATER THIS
AFTERNOON AS BEST INSTABILITY SHIFTS SSE. SPC MESO-ANALYSIS
INDICATES THIS ATTM. ALSO, THINKING HEAVY RAINFALL AND STRONG WIND
GUSTS STILL POSSIBLE. SBCAPES UP AROUND 2000+ JOULES W/LIS DOWN TO
AROUND -5. 0-6KM SHEAR FROM THE LATEST RUC WAS AROUND 25KTS WHICH
WOULD FAVOR POSSIBLE DOWNBURST WINDS. EXPECTING CONVECTION TO WIND
DOWN THIS EVENING AS INSTABILITY AXIS SHIFTS EAST INTO NEW
BRUNSWICK. COLD FRONT WILL CLEAR THE COAST TONIGHT W /DRIER-COOLER
AIR EXPECTED TO FILTER BEHIND THE FRONT. MIDNIGHT CREW/S OVERNIGHT
MINS OF LOW/MID 50S ACROSS THE NORTH W /MID-UPPER 50S CENTRAL AND
DOWNEAST LOOKED GOOD. THE OTHER CONCERN IS FOG RETURNING OVERNIGHT
INTO SATURDAY MORNING. DECIDED ON AREAS OF FOG RIGHT ALONG THE
IMMEDIATE COAST AND OVER THE WATERS. FURTHER INLAND, WENT W/PATCHY
FOG FOR NOW GIVEN THE DRYING TREND. THERE COULD BE A BRIEF TIME
WHEN VSBYS DROP LOWER AS DEWPOINT ALIGNS W/THE TEMPERATURE. THIS
WILL BE ESPECIALLY TRUE IN AREAS FROM EARLIER RAINFALL.
HIGH PRES BUILDING INTO THE REGION FROM CANADA ON SATURDAY WILL
PROVIDE DRY AND PLEASANT CONDITIONS FOR EARLY AUGUST. MAX
TEMPERATURES SHOULD HAVE NO PROBLEM REACHING WELL INTO THE 80S
W/AMPLE SUNSHINE. LATEST MOS/NAM MAXES MATCHED CLOSE TO WHAT THE
MIDNIGHT CREW HAS AND THEREFORE ONLY TWEAKING WAS DONE FOR THE
COAST TO BRING MAXES UP DUE TO OFFSHORE WINDS.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
A WARM FRONT WILL LIFT NORTH THROUGH THE REGION SATURDAY NIGHT
INTO SUNDAY USHERING IN VERY WARM AND HUMID CONDITIONS. EXPECT
HIGHS SUNDAY GENERALLY IN THE MID 80S WITH DEW POINTS RISING INTO
THE MID TO HIGH 60S. WINDS WILL BE GUSTY OUT OF THE SOUTH AND THIS
WILL HELP TO KEEP TEMPERATURES COOLER ALONG THE COAST WHERE HIGHS
WILL BE IN THE 70S. CLOUDS WILL INCREASE IN THE AFTERNOON AHEAD OF
AN APPROACHING COLD FRONT BUT ANY SHOWER/THUNDERSTORM ACTIVITY
LOOKS TO REMAIN WEST OF THE REGION THROUGH THE DAY.
AS THE COLD FRONT CONTINUES TO ADVANCE SUNDAY NIGHT SHOWERS WITH
POSSIBLE THUNDERSTORMS WILL ROLL THROUGH FROM WEST TO EAST AHEAD
OF FRONT DURING THE LATE EVENING INTO THE OVERNIGHT. INSTABILITY
LOOKS TO BE MARGINAL DUE TO THE TIMING OF THE FRONT BEING AT NIGHT
AND AS A RESULT ANY CONVECTION THAT OCCURS DOES NOT LOOK TO BE
SEVERE, ALTHOUGH SOME HEAVY DOWNPOURS WILL BE POSSIBLE. BY MONDAY
MORNING THE FRONT LOOKS TO BE SITUATED CLOSE TO THE WESTERN EDGE
OF THE STATE. SHOWERS AND STORMS WILL CLEAR THE AREA FROM WEST TO
EAST THROUGH THE DAY AS THE FRONT ADVANCES EAST. THE BEST CHANCE
FOR ANY STRONGER STORMS MONDAY WILL BE DOWNEAST AS THAT AREA WILL
BE LAST TO CLEAR DURING THE AFTERNOON.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ZONAL FLOW WILL DEVELOP BEHIND AN EXITING COLD FRONT MONDAY NIGHT.
DRY WEATHER IS EXPECTED IN THE WAKE OF THIS FRONT THROUGH TUESDAY
NIGHT. THE PERSISTENT SUMMER 2012 UPPER TROUGH RETURNS WEDNESDAY
THROUGH FRIDAY. ANTICIPATE A CHANCE OF MAINLY AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS DAYS 5 THROUGH 7 WITH DISTURBANCES
ROTATING AROUND THE BASE OF THE TROUGH. TEMPERATURES WILL BE ABOVE
NORMAL THROUGH THE LONG TERM PERIOD.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR W/TEMPO MVFR THIS AFTERNOON INTO THE EVENING
W/TSTMS FIRING. LEANED W/MVFR VSBY LATER TONIGHT INTO SATURDAY
MORNING FOR THE NORTHERN TERMINALS WHILE KBGR AND KBHB ARE EXPECTED
TO DROP TO IFR BY 09Z SATURDAY. AFTER 12Z SATURDAY, LOOKS LIKE
VFR.
SHORT TERM: LOOKS LIKE VFR SATURDAY NIGHT INTO SUNDAY FOR THE MOST PART.
HOWEVER, MVFR AND IFR POSSIBLE ACROSS KBGR AND KBHB COULD BE SEEN
EARLY SUNDAY MORNING AS WINDS BECOME SOUTHERLY AHEAD OF AN APPROACHING
COLD FRONT. SUNDAY NIGHT INTO MONDAY COULD BE INTERESTING AS THAT STRONGER
COLD FRONT MOVES ACROSS THE REGION W/POSSIBLE TSTMS AND WIND AND MVFR/IFR
CONDITIONS.
&&
.MARINE...
NEAR TERM: NO HEADLINES. MAIN CHALLEGE WILL THE CONTINUING 4-5
FOOT SWELL WHICH IS OUT THERE ATTM. WINDS WILL INCREASE SOME
OVERNIGHT W/THE COLD FROPA, BUT WINDS WILL RELAX ON SATURDAY AS
HIGH PRES MOVES IN FROM CANADA. AREAS OF FOG WILL BE NUISANCE
OVERNIGHT BUT VSBYS SHOULD IMPROVE LATER SATURDAY MORNING. USED
THE NAM12 AND GFS FOR THE WINDS WHICH SUPPORT 10-15 KTS TONIGHT
AND THEN SPEEDS FROP OFF FOR SATURDAY. BROUGHT THE SWELL DOWN TO 3
FT BY MIDDAY SATURDAY W/AN OFFSHORE FLOW.
SHORT TERM: POSSIBLE SCA FOR SUNDAY NIGHT INTO MONDAY AS PRES
GRADIENT TIGHTEN AHEAD AND W/THE FRONTAL PASSAGE. WINDS START COMING
DOWN LATER MONDAY INTO TUESDAY. BACKED OFF A BIT ON THE WNAWAVE BY
DROPPING THEM BACK 1-2 FEET.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS/HEWITT
SHORT TERM...FITZSIMMONS
LONG TERM...OKULSKI
AVIATION...HASTINGS/HEWITT
MARINE...HASTINGS/HEWITT/FITZSIMMONS
AREA FORECAST DISCUSSION
NWS DULUTH MN
323 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
&&
.AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 20 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 40 10 10 0
ASX 81 58 76 56 / 40 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...MELDE
LONG TERM....GSF
AVIATION...GRANING
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
419 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 419 AM EDT SATURDAY...ECMWF AND GFS MODELS SHOW A WEAK
RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT AND
WILL REMAIN OVER THE REGION THROUGH EARLY WEDNESDAY...WITH FAIR
AND DRY WEATHER EXPECTED. ON WEDNESDAY...ECMWF AND GFS MODELS SHOW
SOME WEAK SHORTWAVES WILL MOVE THROUGH THE REGION ON WEDNESDAY AND
EARLY WEDNESDAY NIGHT. GFS AND ECMWF MODELS BOTH SHOW SOME
CONVECTION DEVELOPING ALONG THE INTERNATIONAL BORDER BY WEDNESDAY
AFTERNOON AND EARLY WEDNESDAY NIGHT...SO HAVE GONE WITH SLIGHT
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS NEAR THE CANADIAN
BORDER. ON THURSDAY... MODEL GUIDANCE AGAIN SHOWING SOME MORE WEAK
SHORTWAVES MOVING THROUGH THE REGION...SO HAVE GONE WITH SLIGHT
CHANCE POPS FOR SHOWERS AND THUNDERSTORMS ON THURSDAY. EXPECTING
DRY CONDITIONS THURSDAY NIGHT. ON FRIDAY...ECMWF AND GFS MODELS IN
GOOD AGREEMENT IN SHOWING A LOW AT THE SURFACE AND ALOFT MOVING
EAST FROM THE WESTERN GREAT LAKES... WITH BOTH MODELS SHOWING
SHOWERS AND THUNDERSTORMS DEVELOPING ACROSS THE REGION ON FRIDAY.
ECMWF AND GFS MODELS IN GOOD AGREEMENT THROUGH THE FORECAST
PERIOD. THUS...FORECASTER CONFIDENCE IS HIGH.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR
SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN
AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS
...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY
AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW LEVEL
LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH CONDITIONS
DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING THE
BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS THE
WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE
ADIRONDACKS IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF
THUNDERSTORMS IN THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT
KMPV...KRUT AND KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL
BEGIN TO DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME
SURFACE HEATING.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z
SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...WGH
AVIATION...WGH/RJS
MARINE...KGM/MUCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
235 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF
SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND
UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN
BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION
BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE
COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S.
ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF
HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH
EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF
WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY
AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS
AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND
ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE
PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE
WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT.
TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH
THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD
COVER.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 06Z SUNDAY...MAINLY VFR THROUGH THE PERIOD...EXCEPT FOR
SOME MORNING VALLEY FOG ACROSS THE SHELTERED VALLEYS OF EASTERN
AND NORTHEAST VERMONT...AS WELL AS THE VALLEYS OF THE ADIRONDACKS
...WITH SOME AREAS OF IFR/LIFR IN FOG UNTIL 13Z SATURDAY...ESPECIALLY
AT KSLK AND KMPV. LATEST MODEL GUIDANCE INDICATING STEEP LOW
LEVEL LAPSE RATES DEVELOPING ACROSS THE REGION TODAY...WITH
CONDITIONS DESTABILIZING BY THIS AFTERNOON. MODEL GUIDANCE INDICATING
THE BEST CHANCE FOR SHOWERS AND THUNDERSTORMS TODAY WILL BE ACROSS
THE WESTERN SLOPES OF THE GREEN MOUNTAIN IN VERMONT...AND OVER THE ADIRONDACKS
IN NORTHERN NEW YORK. HAVE INCLUDED A MENTION OF THUNDERSTORMS IN
THE VICINITY AFTER 18Z SATURDAY IN THE TAFS AT KMPV...KRUT AND
KSLK. EXPECTING ANY STORMS THAT DEVELOP TODAY WILL BEGIN TO
DISSIPATE AROUND 00Z SUNDAY...WITH THE LOSS OF DAYTIME SURFACE
HEATING.
OUTLOOK 06Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. MVFR/IFR IN BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z
SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...WGH/RJS
MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
138 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL DROP SOUTH ACROSS THE AREA THIS
EVENING...ACCOMPANIED BY A SMALL CHANCE FOR THUNDERSTORMS THROUGH
EARLY EVENING. MAINLY DRY HOT WEATHER WILL RETURN ON SATURDAY. A STRONGER
COLD FRONT WILL BRING A BETTER CHANCE OF THUNDERSTORMS ON SUNDAY...
FOLLOWED BY COOLER DRY WEATHER ON MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
930 AM UPDATE...NO CHGS TO CRNT FCST WITH A QUIET OVRNGT PD XPCTD.
PREV BLO...
730 PM UPDATE...WELL IT TOOK SOME OF THE HIGHEST TRRN IN THE CWA
TO HELP TRIGGER AN ISOLD TSRA OVER CNTRL DELAWARE CNTY. STORM BCM
ANCHORED NEAR MT PISGAH AND BACK-BUILT/TRAINED FOR NEARLY 2 HRS.
RR AMTS UP 3-3.5 INCHES. THIS STORM HAS SINCE DSPTD AND SEE LTL
POTNL FOR ADDNL DVLPMNT ACRS THE FCST AREA...SO WILL REMOVE POPS
AND GO WITH MAINLY CLEAR TO SKC TNGT. FOG POTNL ALSO LIMITED AND
DON`T XPCT IT TO BE DENSE ENUF TO INCLUDE IN THE WX GRIDS. PREV
BLO...
4 PM UPDATE...MAINLY SKC ACRS THE BGM FCST AREA WITH XCPTN OF SOME
MID/HI CLD ACRS THE FINGER LAKES AND FAR SE ZONES. WSR-88D SHOWS A
WEAK E-W BNDRY BNDRY FROM SRN SCHUYLER/TOMPKINS ACRS NRN BROOME
INTO SRN CHENANGO CNTY. HOWEVER...TD`S ARE LOWEST ACRS THE SRN
TIER AND ANY LOW LVL CONVERGENCE WILL BE WEAK DUE TO THE LGT WINDS
VCNTY OF THE BNDRY. LACK OF UPR DYNAMICS AND LOW LVL CIN CONTINUE
TO IMPEDE DVLPMNT. GIVEN THESE TRENDS...WE LOWERED POPS TO SLGT
CHC FOR LATE THIS AFTN/EVNG AND LOWERED SKY CVR. PREV BLO...
2 PM UPDATE...NOT MUCH GOING ON ATTM ON RADAR AND WITH A BIT OF A
MID LEVEL CAP BETWEEN H8 AND H9 MB....A LOT OF US ARE NOT EVEN
SEEING A CU FIELD FORM. THE EXCEPTION IS ACROSS WESTERN NY NEAR
KROC SOUTHEAST THROUGH THE FINGER LAKES. THIS AREA IS RIGHT AHEAD
OF A COLD FRONT THAT IS WASHING OUT OVER CNY. THIS CU FIELD
MATCHES UP QUITE WELL WITH THE NAM 12 AND LATEST HRRR WHICH
CONTINUES TO SHOW ISOLATED CONVECTION DEVELOPING THROUGH 21Z
ACROSS THE FINGER LAKES...THROUGH THE SOUTHERN TIER INTO NORTHERN
PA. CONTINUED TO PLAY SLIGHT CHANCE POPS OVERALL THROUGH
EVENING...BUT HIGHLIGHT THE AREAS MENTIONED ABOVE FOR A CHANCE OF
A FEW ISOLATED STORMS. SEVERE STORMS ARE NOT EXPECTED GIVEN WEAK
MID LEVEL SHEAR (0-6 KM LESS THAN 20 KTS)...BUT BRIEF GUSTY WINDS
(DOWN BURSTS) A POSSIBILITY GIVEN SBCAPES IN THE 1000-2000 J/KG
RANGE AND AN INVERTED V SOUNDING. WHAT CONVECTION WE SEE THIS
EVENING WILL DIMINISH QUICKLY THIS EVENING.
WE WILL AGAIN BE IN A RICH ENVIRONMENT SATURDAY WITH MLCAPES IN THE
1000-2000 J/KG RANGE BUT WE WILL AGAIN BE LACKING A TRIGGER. THE
FRONT WHICH WILL CAUSE SOME ACTION THIS EVENING...WILL BE WASHED
OUT. ANY UPPER LEVEL SUPPORT LOOKS TO STAY NORTH OF OUR CWA AS THE
UPPER LEVEL FLOW BECOMES MORE SOUTHWESTERLY. CONTINUED WITH THE
MENTIONED OF ISOLATED CONVECTION AS WE MAY HAVE SOME LEFTOVER
BOUNDARIES FROM TODAY BUT MOST WILL REMAIN DRY. THE BIGGEST STORY
SATURDAY WILL AGAIN BE HOT TEMPS WITH HIGHS WELL INTO THE 90S.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
DEEP S-SWLY FLOW WILL BECOME ESTABLISHED OVER THE REGION ON
SATURDAY NIGHT AS SIGNIFICANT UPPER TROF PLOWS THROUGH THE GTLKS
REGION. OVERALL...WILL FOLLOW THE NAM AND ECMWF SOLUTIONS DURING
THIS TIME AS GFS LOOKS A LITTLE AGGRESSIVE IN DEVELOPING
CONVECTION WELL OUT AHEAD OF THE MAIN TROF WITHOUT MUCH FORCING.
THAT SAID...WILL CARRY SOME SMALL CHANCES FOR TSRA ACROSS THE
SOUTHERN PART OF FCST AREA AS BEGINNINGS OF HEIGHT FALLS AND
POTENTIAL FOR AN EMBEDDED MINOR WAVE COMING OUT OF PENNSYLVANIA
COULD SPAWN SOME LATE NIGHT ACTIVITY AND THE 12KM NAM IS
SUGGESTING SOME ACTIVITY IN CNTRL PA WORKING NORTH FROM 03Z-09Z.
ON SUNDAY...DESTABILIZATION OF THE LOWER TROPOSPHERE WILL
CONTINUE...MAINLY DUE TO THE INFLUX OF LOW LEVEL MOISTURE AS
OPPOSED TO A LOT OF PRISTINE SOLAR HEATING HOURS. CNY/NEPA REGION
SHOULD START THE DAY OFF PRETTY JUNKED UP WITH LOW LVL CLOUDINESS
AS A RESULT OF WARM AND MOIST ADVECTIONS SAT NIGHT. BREAKS IN
CLOUDS ARE EXPECTED LATER ON WITH OVERALL MEAN LYR CAPE VALUES
RANGING IN THE 1000-1500 J/KG RANGE. WITH SUCH A DYNAMIC UPPER
SYSTEM APPROACHING...THIS IS MORE THAN ENOUGH ENERGY. 0-3 KM AND
0-1 KM BULK SHEAR VALUES ARE FCST IN THE 25-30 KT RANGE IN A
VERTICALLY LAMINAR FASHION. THE MODEL TRENDS CONTINUE TO SLOW THE
PASSAGE OF THE ACTUAL SFC FRONT DOWN TO LATE SUNDAY NIGHT...HOWEVER
REGIME OF 500 MB HEIGHT FALLS AND BEST JET DIVERGENCE ARE EXPECTED
TO COINCIDE OVER CNY/NEPA DURING THE LATE AFTERNOON AND EVENING
HOURS. AT THIS TIME...THE PARAMETERS SUGGEST A LINEAR CONVECTIVE
MODE OF MULTICELLS AND LINES WITH WIND DAMAGE THE HIGHEST CONCERN.
HEADING INTO MONDAY...THE FRONT AND UPPER TROF AXIS CLEARS THE
REGION SHORTLY BEFORE 12Z WITH COOLER AND DRIER HIGH PRESSURE TO FOLLOW.
HAVE REDUCED POPS ON MONDAY TO JUST THE EARLIEST FEW HOURS AROUND
12Z...AND THAT STILL MAY BE A BIT TOO MUCH WITH MOST MODEL TRENDS
SUGGESTING THAT DEEP MOISTURE AND FORCING WILL BE EAST OF THE REGION.
CLOUDS MAY LIMIT TEMPS A BIT ON SUNDAY...BUT STILL EXPECT TO BE
WELL INTO THE 80S AFTER A PRETTY MILD AND MUGGY START TO THE DAY.
IT SHOULD FEEL RATHER OPPRESSIVE WITH FCST DWPTS REACHING THE
LOWER 70S ON SUNDAY...BUT WITHOUT TEMPERATURES SURGING INTO THE
90S THE DANGER FROM EXCESSIVE HEAT IS NOT ANTICIPATED.
COOLER...DRIER AND MORE SEASONABLE CONDITIONS ARE FORECAST MONDAY
AND GENERALLY FOLLOWED BLENDED MOS GUIDANCE TRENDS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE LINGERS OVER THE REGION THROUGH TUESDAY...WHICH WILL
THEN BE FOLLOWED BY ANOTHER WEAK COLD FRONT AND BROAD UPPER TROF
DRIFTING INTO THE REGION FROM WEDNESDAY THROUGH FRIDAY. THESE
FEATURES WILL LIKELY ACT AS THE FOCUS FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS...MAINLY DRIVEN BY DIURNAL INFLUENCES. THE
LATEST GFS AND LAST NIGHT/S ECMWF DEFINITELY DIFFER ON SOLUTIONS
FOR THIS PERIOD WITH THE ECMWF ILLUSTRATING A STRONGER TROF
PASSAGE THROUGH THE EAST THURSDAY NIGHT INTO FRIDAY. HPC THINKS
THIS HAS LITTLE SUPPORT WITHIN THE GENERAL ENSEMBLE FORECASTS AND
WILL LEAN WITH THEIR GENTLER APPROACH.
ENSEMBLE THERMAL FORECASTS AT 850 MB SHOW NO ANOMALOUS DEVIATIONS...
THEREFORE WILL FOLLOW A BLEND OF HPC AND MOS GUIDANCE ON
TEMPERATURES WHICH SHOULD TURN OUT TO BE FAIRLY NORMAL.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
IN GENERAL VFR CONDITIONS ARE EXPECTED THROUGH THIS TAF PERIOD.
THERE MAY BE MVFR VSBY RESTRICTIONS DUE TO HZ/BR AT KELM/KAVP
EARLY THIS MORNING BETWEEN 09Z-12Z. JUST SCATTERED CI THROUGH MID
MORNING THEN SCT CU AROUND 5K FT TODAY. ISOLATED CONVECTION IS
POSSIBLE THIS AFTERNOON IN THE HIGHER TERRAIN BUT NOT INCLUDED IN
TAFS DUE TO VERY LIMITED AREAL COVERAGE. OVERNIGHT AS NEXT SYSTEM
APPROACHES REGION SCT MID CLOUDS ARE LIKELY.
WINDS WILL BE LIGHT AND VARIABLE INTO MID MORNING THEN SOUTHERLY
AROUND 10 KNOTS BECOMING SOUTHEAST TONIGHT AROUND 5 KNOTS.
OUTLOOK...
SUN MORNING...VFR WITH POSSIBLE MVFR VSBYS RESTRICTIONS EARLY SUN
AM DUE TO HAZE.
SUNDAY AFTERNOON THROUGH SUNDAY EVENING...A COLD FRONT PASSING
THROUGH THE REGION WILL PRODUCE WIDESPREAD SHOWERS AND THUNDERSTORMS
WITH MVFR/IFR RESTRICTIONS IN STORMS.
MON - WED...AT THIS EARLY VANTAGE PT...PRIMARILY VFR ANTICIPATED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...JAB
NEAR TERM...HEDEN
SHORT TERM...JAB
LONG TERM...JAB
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1257 AM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT SITUATED ACROSS THE NORTH COUNTRY WILL CONTINUE
TO DROP SOUTH OF OUR REGION OVERNIGHT. THIS FRONT WILL LIFT NORTH
BACK ACROSS OUR FORECAST AREA AS A WARM FRONT ON SATURDAY. SUNDAY
NIGHT ANOTHER COLD FRONT WILL CROSS THE REGION. HIGH PRESSURE
WILL THEN BUILD OVER THE REGION UNTIL ANOTHER COLD FRONT CROSSES
THE AREA WEDNESDAY NIGHT INTO THURSDAY MORNING. ABOVE NORMAL
TEMPERATURE TREND WILL CONTINUE THROUGH MOST OF THE 8 DAY
FORECAST.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
AS OF 1257 AM EDT SATURDAY...OVERALL FORECAST IN GOOD SHAPE WITH
MINOR ADJUSTMENTS TO HOURLY TEMPERATURES AND DEWPOINTS. ALSO
ADDED PATCHY FOR FOR FAVORED AREAS AS RELATIVE HUMIDITIES OVER 90
PERCENT IN SOME LOCATIONS AND CONTINUED CLEAR SKIES WITH LITTLE
TO NO WIND WILL KEEP RADIATIONAL COOLING GOING FOR A FEW MORE
HOURS BEFORE THE SUN STARTS TO RISE.
PREVIOUS DISCUSSION FOLLOWS...ANOTHER ROUND OF MINOR ADJUSTMENTS
PERFORMED...MAINLY TO TEMPERATURE TRENDS NEAR LAKE CHAMPLAIN.
MODIFICATION OF AIR TEMPERATURES NEAR LAKE CHAMPLAIN CONTINUE TO
KEEP LOCATIONS ADJACENT TO THE LAKE WARMER THAN PREVIOUSLY
FORECASTED...HAVE INCREASED OVERALL TEMPERATURES AROUND AND OVER
THE LAKE TO ACCOUNT FOR THESE DIFFERENCES KEEPING MINIMUMS IN THE
UPPER 60S NEAR 70 OVERNIGHT. THERE HAVE BEEN SOME INDICATIONS IN
THE HRRR 3KM MODEL THAT INSTABILITY ASSOCIATED WITH LAKE ONTARIO
WILL KICK OFF SOME EARLY MORNING SURPRISE SHOWERS AND AN ISOLATED
THUNDERSTORM AROUND 10Z TO 12Z. CONTINUE TO HOLD BACK ON POPS DUE
TO THERE BEING ONLY ONE INDICATOR THAT THIS WILL HAPPEN.
OTHERWISE...OTHER THAN SOME FOG/MIST FORMING WHERE PRECIPITATION
OCCURRED FRIDAY AFTERNOON...BENIGN WEATHER CONTINUES TO BE
ANTICIPATED FOR THE NOCTURNAL HOURS. TEMPERATURES OVERNIGHT WILL
GENERALLY BE IN THE LOW 60S FOR THE VALLEYS AND MID 50S IN THE
HIGHER TERRAIN WITH A FEW OF THE COLDER HOLLOWS DROPPING TO NEAR
50 DEGREES.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH SUNDAY NIGHT/...
AS OF 500 PM EDT FRIDAY...COLD FRONT WHICH DROPPED SOUTH ACROSS
THE AREA ON FRIDAY WILL LIFT BACK NORTH OF THE AREA AS A COLD
FRONT ON SATURDAY. SATURDAY WILL BE HOT...A GOOD 10 DEGREES ABOVE
NORMAL WITH SOME MAX TEMPS IN THE UPPER 80S TO LOWER 90S. SHOWERS
AND THUNDERSTORMS WILL POP OFF ALONG THE FRONT AS CAPE VALUES
SURGE INTO THE MID 2000 RANGE...LIFTED INDICES DROP TO AROUND -8
AND SHOWALTERS AROUND -5. SHEAR WILL BE LACKING WITH WEAK FLOW IN
GENERAL...THEREFORE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS.
CONVECTION SHOULD BE SCATTERED WITH HIGHEST POPS DEPICTED OVER
THE HIGHER TERRAIN.
STORMS DIE DOWN FOLLOWING SUNSET WITH LOSS OF DAYTIME
HEATING...THOUGH NOT MUCH RELIEF AS FAR AS TEMPS ARE CONCERNED
WITH REGION IN WARM SECTOR BEHIND THE WARM FRONT. TEMPS WILL ONLY
DROP INTO THE MID TO UPPER 60S OVERNIGHT. FOG CAN AGAIN BE
EXPECTED IN AREAS THAT HAD RAINFALL SATURDAY AFTERNOON.
DURING THE DAYTIME HOURS ON SUNDAY...CHANCE FOR SHOWERS AND
THUNDERSTORMS AHEAD OF APPROACHING COLD FRONT WILL INCREASE WEST
TO EAST ACROSS THE AREA. SUNDAY WILL ALSO BE WARM AND MUGGY WITH
MAX TEMPS IN THE MID TO UPPER 80S AGAIN. SOUTHERLY FLOW WILL
PROVIDE SOME INSTABILITY AHEAD OF APPROACHING FRONT...CAPE VALUES
WILL REACH AROUND 1800 LATE IN THE AFTERNOON...LIFTED INDICES
AROUND -5. AS FRONT APPROACHES THE NORTH COUNTRY...STORMS WILL
REACH THE SAINT LAWRENCE VALLEY REGION AROUND 21Z...THEN TRACK
EASTWARD OVERNIGHT...ADIRONDACKS AROUND 00Z...AND MOVING INTO
VERMONT AFTER MIDNIGHT. SHEAR IS MORE DECENT SUNDAY
NIGHT...THOUGH BEST SHEAR WILL MOVE NORTH OF OUR REGION. PWATS
OVER 1.75" THEREFORE COULD HAVE HEAVY RAIN WITH ANY THUNDERSTORMS
THAT DEVELOP. FRONT WILL MOVE THROUGH AT A PRETTY STEADY
PACE...SO NO LARGE SCALE FLOOD ISSUES EXPECTED THOUGH ISOLATED
FLOODING IS POSSIBLE. TEMPERATURES SUNDAY NIGHT WILL REMAIN
MILD...ONLY DROPPING TO THE UPPER 60S TO AROUND 70.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 344 PM EDT FRIDAY...ECMWF AND GFS INDICATE A CHANCE OF
SHOWERS EARLY MONDAY...MAINLY ACROSS VERMONT...AS COLD FRONT AND
UPPER TROUGH PUSH EAST OF THE REGION. MID LEVEL DRY SLOT THEN
BUILDS IN BY MIDDAY...SO EXPECT CLEARING SKIES ACROSS THE REGION
BY MONDAY AFTERNOON. IT WILL TURN LESS HUMID AND BE A LITTLE
COOLER...WITH HIGHS GENERALLY IN THE UPPER 70S AND LOWER 80S.
ECMWF AND GFS REMAIN IN GOOD AGREEMENT IN SHOWING A WEAK RIDGE OF
HIGH PRESSURE OVER THE NORTH COUNTRY FROM MONDAY NIGHT THROUGH
EARLY WEDNESDAY...WITH FAIR AND DRY WEATHER EXPECTED. A SERIES OF
WEAK UPPER SHORTWAVES WILL THEN MOVE ACROSS THE REGION WEDNESDAY
AFTERNOON THROUGH THURSDAY...BRINGING A LOW CHANCE FOR SHOWERS
AND STORMS TO THE REGION...ESPECIALLY TO THE HIGHER TERRAIN AND
ACROSS THE NORTHERN ZONES. LATEST ECMWF INDICATING A MORE
PRONOUNCED TROUGH MOVING INTO THE NORTHEAST FRIDAY...SO HAVE GONE
WITH CHANCE POPS ACROSS THE ENTIRE AREA FRIDAY INTO FRIDAY NIGHT.
TEMPERATURES WILL BE A BIT ABOVE NORMAL TUESDAY THROUGH
THURSDAY...THEN LOWER TO SEASONAL LEVELS FRIDAY DUE MORE CLOUD
COVER.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THROUGH 00Z SUNDAY...VFR CONDITIONS EXPECTED AT MOST LOCATIONS
THROUGH THE PERIOD. THE ONLY EXCEPTION TO THIS WILL BE SOME VLIFR
CONDITIONS AT KSLK AND KMPV BETWEEN 07Z AND 13Z DUE TO LOW CLOUDS
AND FOG. SCATTERED CUMULUS CLOUDS SHOULD FORM SATURDAY AFTERNOON
AND ISOLATED STORMS WILL DEVELOP AFTER 20Z. WINDS WILL GENERALLY
BE LIGHT AND VARIABLE TONIGHT...THEN TREND TOWARD A MORE
SOUTHERLY DIRECTION LATE SATURDAY MORNING INTO AFTERNOON.
OUTLOOK 00Z SUNDAY THROUGH WEDNESDAY...MAINLY VFR THROUGH MIDDAY
SUNDAY. THERE WILL BE WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
SATURDAY AFTERNOON/EVENING WITH BRIEF MVFR POSSIBLE. MVFR/IFR IN
BR/FG ALSO POSSIBLE AT MPV/SLK 06Z-12Z SUNDAY.
APPROACH OF COLD FRONT WILL LEAD TO WIDESPREAD CONVECTION LATE
SUNDAY THROUGH SUNDAY NIGHT. A FEW OF THE STRONGER STORMS SUNDAY
AFTERNOON/EVENING HAVE THE POTENTIAL TO PRODUCE PERIODS OF IFR
CONDITIONS. CHANCE OF GUSTY WINDS WITH THUNDERSTORMS AS WELL.
COOLER AND DRIER AIR ARRIVES ON MONDAY WITH MAINLY VFR CONDITIONS
ANTICIPATED MONDAY INTO WEDNESDAY AS A RIDGE OF HIGH PRESSURE
BUILDS INTO THE REGION.
&&
.MARINE...
LIGHT AND VARIABLE WINDS TONIGHT INTO EARLY SATURDAY MORNING WILL
SHIFT OUT OF THE SOUTH AT 5 TO 15 KNOTS DURING THE DAY SATURDAY.
HOWEVER...WINDS WILL INCREASE SATURDAY NIGHT AND ESPECIALLY ON
SUNDAY WITH STRONG SOUTH WINDS FROM 20 TO 30 KNOTS ANTICIPATED.
WAVES WILL BE 1 TO 2 FEET THROUGH SATURDAY...BUILDING TO 2 TO 4
FEET BY SUNDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...NEILES
NEAR TERM...KGM/BOYD
SHORT TERM...NEILES
LONG TERM...RJS
AVIATION...EVENSON/RJS
MARINE...KGM/MUCCILLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
340 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 330 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO RIDGE
ACROSS THE FA BOTH SFC AND ALOFT THRU THE PERIOD. AN INVERTED SFC
TROF TO PASS OVER THE BAHAMAS TODAY...AND TRACK NW TO AND ACROSS THE
NORTHERN FLORIDA PENINSULA TONIGHT INTO SUNDAY. HOURLY NAMBUFR
SOUNDINGS INDICATE A GENERAL INCREASE OF PWS TO AROUND 2 INCHES
TONIGHT INTO SUNDAY. WINDS THRU THE ATM COLUMN TO BECOME BASICALLY
ONSHORE INDICATIVE OF A TROPICAL INFLUENCE ACROSS THE FA. THE SEA
BREEZE OR RESULTANT WIND TYPE CONVECTION WILL COMMENCE BY MID-LATE
THIS MORNING...AND TRACK INLAND THROUGHOUT THE DAY AS ADVERTIZED BY
THE LATEST HRRR MODEL RUNS. MODEL SOUNDING DATA INDICATE PWS OF 2
INCHES...AND A SLOW MOVEMENT OF THE CONVECTION...BASICALLY BETWEEN 5
AND 10 KT. AS A RESULT...THE MAIN THREAT FROM TODAYS CONVECTION WILL
BE FROM HEAVY RAIN. FOR TONIGHT...ONSHORE MOVEMENT OF PCPN DURING
THE PRE-DAWN HRS OF SUNDAY TO OCCUR AS A MUCH DEEPER ONSHORE FLOW TO
EVOLVE THRU THE ATM COLUMN. WILL ILLUSTRATE LOW CHANCE POPS FOR THE
COASTAL AREAS. COMPROMISED BETWEEN THE VARIOUS MODEL MOS GUIDANCE
FOR MAX/MIN TEMPS THRUOUT THE NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE
08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER
POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL
TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000
FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW
SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD
DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE
PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH
CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH
EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT
EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE FLORIDA PENINSULA SUNDAY. WIND SPEEDS MAY
INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT SEAS WILL
BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9 SECOND
PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO THE
CLOSER PROXIMITY OF THE EFFECTS FROM THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
329 AM EDT SAT AUG 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A
COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL
STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 3 AM SATURDAY...LATEST RAP MODEL ALONG THE NAM12/GFS SHOW A
THREAT OF SOME SHOWERS AND POSSIBLE TSTMS WILL AFFECT THE COAST
DURING THE EARLY MORNING HOURS AS STRONG MID-LEVEL VORT CENTER
TRACKS UP THE CAROLINA COAST IN AN UPPER-LEVEL WEAKNESS. RADAR
ALREADY SHOWING SOME SHOWERS DEVELOPING ABOUT 100 MILES DUE SOUTH
OF THE CRYSTAL COAST...SO HAVE RAISED POPS TO LOW CHC ALONG THE
COAST THROUGH MIDDAY. ADDITIONAL ISOLATED SHOWERS WITH A FEW TSTMS
MAY OCCUR ALONG THE SEA BREEZE LATER THIS AFTERNOON AND WILL HAVE
A SLIGHT CHC ALONG THE SEA BREEZE ZONE AT THAT TIME. MAX TEMPS
SHOULD MAINLY BE IN THE UPPER 80S TO AROUND 90 UNDER PARTLY CLOUDY
SKIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND
SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING
WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL
HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY
NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD
AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH
WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS
ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY...
SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK
SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR
CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE
IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE
EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE
AROUND MID TO LATE WEEK TIME FRAME.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND
GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY
FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S FLOW
WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE AFTERNOON.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH
AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE
LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT
RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING
TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 310 AM SATURDAY...WINDS HAVE DROPPED A BIT IN THE PAST
COUPLE OF HOURS AND ARE GENERALLY 12 KNOTS OR LESS FROM THE S/SW
WITH SEAS AT 1 TO 3 FEET WITH 7 TO 8 SECOND SWELLS. NOT PLANNING
ANY MAJOR CHANGES TO MARINE FORECAST AS S/SW WINDS WILL CONTINUE
TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST WITH FRONTAL
BOUNDARY REMAINING WELL OFF TO THE WEST IN THE OHIO VALLEY. THIS
WILL LEAD TO S/SW WINDS 10 TO 15 KNOTS WITH SEAS 2 TO 3 FEET
THROUGH TONIGHT.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE
LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS...
AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT
RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE
CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT
AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
102 AM EDT SAT AUG 4 2012
.SYNOPSIS...
WEAK UPPER LEVEL LOW PRESSURE WILL GRADUALLY LIFT OUT TONIGHT AS
HIGH PRESSURE BUILDS WEST INTO THE AREA FROM OFFSHORE THROUGH THE
WEEKEND. A COLD FRONT WILL APPROACH FROM THE NORTHWEST MONDAY AND
STALL ACROSS THE PIEDMONT INTO THE MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM SATURDAY...SIGNALS IN SEVERAL OF THE SHORT-TERM
MODELS INDICATE A DECENT MID-LEVEL SHORTWAVE TO MOVE NORTH ACROSS
EASTERN NORTH CAROLINA IN WEAKNESS BETWEEN AREAS OF HIGH PRESSURE
WELL TO THE EAST AND OVER THE SOUTHERN PLAINS. THE RAP/GFS AND TO
A LESSER EXTENT THE NAM ALL SHOW LIGHT QPF NEAR THE COAST FROM
ABOUT 10Z THIS MORNING INTO EARLY AFTERNOON. HAVE FOLLOWED SUIT
WITH CHANCE POPS NEAR THE COAST TAPERING TO NIL WEST OF HIGHWAY 17
THROUGH EARLY AFTERNOON. NO OTHER MAJOR CHANGES TO THE FORECAST AT
THIS TIME.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
AS OF 340 PM FRI...UPPER LEVEL RIDGE BEGINS TO MIGRATE WEST INTO
EASTERN NC ON SAT ALTHOUGH LOW LEVEL THICKNESSES CHANGE
LITTLE...RANGING 1415-1420 METERS WHICH WILL YIELD MAX TEMPS IN
THE LOWER 90S INLAND TO UPPER 80S ALONG THE COAST. FORECAST
SOUNDINGS INDICATE AN UNSTABLE AIRMASS WILL PERSIST SAT WITH PWATS
OVER 1.75 INCHES...CAPE VALUES ABOVE 3000 J/KG AND LIFTED INDICES
OF -7 TO -9 C. CONTINUED FORECAST FOR DIURNAL CONVECTION INLAND
ASSOCIATED WITH SEA BREEZE BOUNDARY PROPAGATION FOR THE AFTERNOON
HOURS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 155 PM FRI...MODELS IN GOOD AGREEMENT IN THE LONG TERM. WARM
AND HUMID THROUGH THE PERIOD WITH THE BERMUDA HIGH RIDGING ACROSS
THE SOUTHEAST MAINTAINING A SOUTHWEST FLOW. A COLD FRONT WILL
APPROACH FROM THE NORTHWEST EARLY NEXT WEEK BUT WILL BECOME
STATIONARY OVER THE CENTRAL PART OF THE STATE. THE FRONT WILL
DISSIPATE BY MIDWEEK LEAVING A WEAK SURFACE THROUGH THROUGH
FRIDAY. TYPICAL SUMMERTIME WEATHER WITH SCATTERED MAINLY DIURNAL
SHOWERS AND THUNDERSTORMS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH 00Z SUNDAY/...
AS OF 1 AM SAT...SOME MVFR FOG HAS DEVELOPED AT KEWN AND KISO AND
GIVEN LIGHT SE FLOW AND MOIST BOUNDARY LAYER EXPECT SOME PATCHY
FOG THROUGH THE EARLY MORNING HOURS. SAT WILL SEE CONTINUED S
FLOW WITH ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE
AFTERNOON.
LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
AS OF 150 PM FRI...SOUTHWEST SURFACE FLOW WILL PERSIST THROUGH THE
PERIOD...GENERALLY 10-15 KNOTS BY DAY AND LESS THAN 10 KNOTS AT
NIGHT. SCATTERED MAINLY AFTERNOON/EVENING THUNDERSTORMS WITH
LOCALLY LOWER CEILINGS/VISIBILITIES.
&&
.MARINE...
SHORT TERM /THROUGH SATURDAY/...
AS OF 1 AM SAT...WINDS ARE RUNNING JUST A BIT ABOVE FORECAST
VALUES WITH OBSERVED VALUES NEAR 15 KNOTS AT OREGON
INLET...DIAMOND BUOY AND CAPE LOOKOUT. HAVE UPPED THE WINDS BASED
ON THE LATEST RAP MODEL. SEAS REMAIN IN THE 2 TO 3 FEET RANGE AND
NO CHANGES NEEDED TO THE WAVEHEIGHT FORECAST.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/
AS OF 150 PM FRI...LATEST RUNS OF THE ECMWF/GFS/NAM IN VERY CLOSE
AGREEMENT THROUGH THE LONG TERM PERIOD SO USED AN OVERALL BLEND.
THE BERMUDA HIGH WILL BE THE MAIN FEATURE IN THE WEATHER
MAINTAINING A SOUTHWEST FLOW BUT SPEEDS AND SEAS WILL REMAIN BELOW
SMALL CRAFT LEVELS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DAG
NEAR TERM...CTC
SHORT TERM...DAG
LONG TERM...HSA
AVIATION...CTC/HSA/JBM
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
452 AM EDT SAT AUG 4 2012
.SYNOPSIS...
SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS
LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER
WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER
LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY
NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY
NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD
INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN
THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING
INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT
ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED
FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS
THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR
FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION.
WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN
ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD
COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY
LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES
DO APPROACH 100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION
AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN
BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER
TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY
DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY
DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS
THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN
IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE
REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL
ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE
DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT
STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE
ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS
OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR
POTENTIAL OF VERY HIGH RAINFALL RATES.
WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO
RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH
POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS
TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL
SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON
HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION.
HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE
AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE.
WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR
SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH
TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY
CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO
OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE
REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED
COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW
SEASONABLE VALUES DURING THE DAY.
THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH
TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW
PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE
WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE
SOUTH...TO THE MID 50S ACROSS THE NORTHEAST.
BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE
OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE
OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE
SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL
THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION
TOWARD THE END OF THE WEEK.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS MAY BE INTERRUPTED BY BR TONIGHT IN A HUMID
AIRMASS. SCATTERED CONVECTION TRIGGERED BY WEAK DISTURBANCES IN
AN UNSTABLE REGIME WILL AFFECT TAF SITES ON SATURDAY. WINDS WILL
BE OUT OF THE SOUTH WITH GUSTS NEAR 20 KNOTS SATURDAY AFTERNOON.
.OUTLOOK...SHOWERS AND THUNDERSTORMS ARE LIKELY SATURDAY NIGHT
AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...JDR
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 AM CDT SAT AUG 4 2012
.TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION
AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY.
SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING
TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A
SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM
AND 3AM ON CURRENT PACE.
HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES
AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS
SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING
FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE
INCREASES AHEAD OF TROUGH.
STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE
AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR
INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500
MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE
WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY
UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING
ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING.
IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE
BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED
INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES.
FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL
BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS
TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S.
BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE
AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR
DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000
J/KG.
PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH
DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE
WEST.
.SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND
MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A
FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS
THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER
AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR
NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY.
.TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM
MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT
OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION
IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD
SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL.
.THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH
CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM.
NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK
WEEK...WITH 80S CONTINUING.
&&
.AVIATION/12Z TAFS/...
WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL
EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z
AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY
EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST.
NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN
BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW
CLOUDS/FOG AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
246 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...
1120 PM CDT FRI AUG 3 2012
LINE OF CONVECTION CONTINUES TO TRACK EAST ACROSS MN LATE THIS
EVENING...AND THIS WILL IMPACT KRST AND KLSE. AT ITS CURRENT PACE IT
WILL REACH KRST BY 0530Z AND KLSE NEAR 07Z. THE STORMS ARE PACKING
QUITE A BIT OF WIND...EXPECT NORTHWEST GUSTS UPWARDS OF 40 TO 50 KTS
AT KRST...CLOSER TO 40 KTS AT KLSE. THE LINE SHOULD SWEEP EAST OF
KRST BY 09Z AND KLSE BY 11Z.
MORE SHRA/TS WILL MOVE IN LATER SAT MORNING...CONTINUING INTO THE
AFTERNOON...AS A COLD FRONT DRIVES EAST ACROSS THE REGION. NAM12
BRINGS IT ACROSS KRST AROUND 16Z AND KLSE NEAR 18Z. SOME OF THESE
STORMS COULD ALSO BECOME STRONG TO SEVERE...WITH WIND AND HAIL THE
THREATS. THE GREATER THREAT WILL LIKELY BE AT KLSE WHERE TIMING WILL
FAVOR MORE INSTABILITY...AND THUS THE POTENTIAL FOR STRONGER STORMS.
EXPECT MOST OF THE ACTIVITY TO EXIT EAST BETWEEN 21-00Z...WITH A
CLEARING TREND IN THE EVENING AS HIGH PRESSURE OVER THE PLAINS
STARTS TO INFLUENCE THE LOCAL AREA. PRESSURE GRADIENT STAYS
RELATIVELY TIGHT THOUGH...SO THERE MIGHT NOT BE A LOT OF DROP OFF IN
WINDS SAT NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS PUEBLO CO
408 AM MDT SAT AUG 4 2012
.SHORT TERM...
(TODAY AND TONIGHT)
COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH
THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE
BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF
SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW
POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT
ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS
HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN
SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS
OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY
THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS
EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE.
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING
AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE
PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY
AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH
SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS.
MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH
TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG
THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH
MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE
SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM
BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY.
LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE
FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS
TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE
TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING
AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE
GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS
SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY.
TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS
OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS
UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD
BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE
DEGREES. -KT
.LONG TERM...
(SUNDAY THROUGH SATURDAY)
THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE
FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER
ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO
BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST
ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE
BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND
HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP
THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH
PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH
AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT
WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL
HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS
FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON
SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE
PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO
LOWER 100S FOR THE PLAINS.
TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER
THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP
KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO
LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP
WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM
COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN.
WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL
REMAIN ANCHORED TO THE MOUNTAINS. MOZLEY
&&
.AVIATION...
MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND
NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO
30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS
DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE
AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY
PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO
SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE
AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND
SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER
CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO
LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE
LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER
SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE
NIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
31/88
AREA FORECAST DISCUSSION
NWS MIAMI FL
724 AM EDT SAT AUG 4 2012
.AVIATION...
A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS
SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS
FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND
WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD
TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY
LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST.
WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY
16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND
POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS
TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK
OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E
COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION.
SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE
MOVES PAST ANY ONE TERMINAL LATER TODAY.
&&
.PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/
..LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
..MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
936 AM EDT SAT AUG 04 2012
.Mesoscale Discussion...
Issued at 936 AM EDT Sat Aug 4 2012
With the exception of a slight uptick in intensity over the southern
Blue Grass, storms in the rest of the LMK CWA are continuing to fall
apart this morning. Once the Blue Grass convection heads
east/weakens, we should see a relative lull in the precip before
scattered storms are able to fire up in the warm unstable air this
afternoon. In the grids we have decreased PoPs for the late morning
hours before bringing them back up in the afternoon.
Have been keeping an eye on the convection south of St Louis this
morning. HRRR has had the best handle on this activity, and that
model dives the thunderstorms to the SSE through western Kentucky,
west Tennessee, and into Alabama. So far this is being borne out on
regional radar loops. However, while that path would be to the west
of the LMK CWA, model data are hinting at new convection possibly
firing up on outflow heading east from the Mississippi Valley storms
into central Kentucky and, to a lesser extent, southern Indiana.
This further supports chance PoPs for the afternoon hours.
We have cut high temps in the southeast where morning clouds and
showers will linger the longest. Have left temperatures alone in
the rest of the area where more sunshine is occurring or expected.
May flirt with Heat Advisory criteria briefly this afternoon in the
far west, thanks more to dew points in the lower and middle 70s than
the air temperature, but with cirrus shield moving in from the west
and the brevity of any indices AOA 105, will stick with the SPS for
now.
Issued at 810 AM EDT Sat Aug 4 2012
Storms have been on the decrease over the past couple of hours as
the NLLJ weakens. However, some strong storms remain, especially
INVOF Elizabethtown and Hodgenville. Torrential rainfall is
occurring in these low centroid storms thanks to very high
precipitation efficiency in a soupy air mass. Have upped PoPs to
categorical where it is currently raining as well as downstream to
the east. Have also introduced "heavy rain" wording -- the
Elizabethtown KY Mesonet site reported 0.31 inches of rain in just 5
minutes. Have also greatly increased QPF numbers, to around an inch
and a half INVOF the Hardin/LaRue storms, and 0.50-0.75" downstream
into the Blue Grass.
&&
.Short Term (Today through Sunday)...
Issued at 325 AM EDT Sat Aug 4 2012
A lot to talk about in the short-term period. To start off with, a
weak low-level jet is setting up early this morning across central
Kentucky. This is aiding in moisture advection and lift. A few
showers and thunderstorms have developed along the KY-TN border and
continue to push northeast into central Kentucky. Additional
development is possible, but overall areal coverage should be
limited. These, mainly isolated, showers and thunderstorms will
dissipate as the low-level jet relaxes shortly after sunrise. We
should then be mainly dry until the afternoon hours, but an isolated
shower/storm cannot be ruled out given the moist air mass.
For the rest of today, there is a weak wave across portions of
Missouri propagating eastward early this morning. It seems this will
initiate convection across eastern Missouri a little later, which
will push east into our area later this afternoon. This should act
to increase our thunderstorm potential and coverage throughout the
day, particularly with diurnal heating. Will have to see if this
solution pans out, but either way, convection should fire this
afternoon just due to heating, with highs topping out in the lower
90s. Heat indices will top out in mid and upper 90s across the east,
with 100 to around 105 expected along and west of I-65. Still
expecting convection to decrease as the sun sets this evening.
Activity should ramp up again, mainly across southern Indiana and
north-central Kentucky as a low-level jet increases ahead of our
approaching cold front. Convection associated with this feature
appears to dissipate a bit shortly after sunrise as well, with the
loss of the low-level jet. However, convection will increase in
coverage throughout the day Sunday, mainly across central Kentucky
and points south/east, as the cold front pushes southeast through
the forecast area during peak heating.
Here is a caveat. The latest 4km NAM indicates convection along the
cold front should initiate late this afternoon/early evening across
portions of northern Illinois and central Missouri. This model
generates a good cold pool, which drops the convection quickly
southeast and into portions of southern Indiana shortly after
midnight. This line appears to be in a weakening stage, but arrives
faster than most models are predicting. This solution also continues
pushing the outflow boundary southeast where additional storm
development occurs across central and south-central Kentucky before
sunrise Sunday. If this pans out, most convection will be overnight,
with the Sunday afternoon storms having less coverage and being
confined to the frontal boundary forcing. Given the uncertainty
amongst models and this seeming to be an outlier, will not jump
completely on this solution, but this will be key to watch as the
day unfolds. This model has shown some positive results over the
last few days.
Otherwise, models continue to indicate total PWs of almost 2 inches
for today, which increases to just over 2 inches for Sunday. High
temperatures Sunday should reach the mid and upper 80s, with a few
locations perhaps touching 90 degrees. This will yield CAPE values
in the 2000-3000 J/kg range, especially across southern and eastern
portions of the forecast area during Sunday afternoon. Shear appears
to be maximized in the afternoon as well, with 0-6km bulk shear
values in the 20-30 knot range. Damaging wind, very heavy rainfall,
and some hail will be the main threats. Given the recent rainfall
across the area and the increase in total moisture through Sunday,
there could be localized flash flooding concerns.
.Long Term (Sunday Night through Friday)...
Issued at 304 AM EDT Sat Aug 4 2012
The first forecast challenge in the long term will be the timing of
Sunday`s cold front pushing through the region Sun night/early Mon.
Models vary in exactly when the front and unstable airmass will push
south of our area. Because this weather system is on in the
stronger side, will go with a more progressive soln closer to the 0Z
GFS and GFS ensembles. This would push the front through early Mon
morning and stall it out just to our south over TN during the day
Mon. So, with this timing in mind, strong to severe storms with
damaging winds, torrential rainfall, and cloud to ground lightning
may linger east of I-65 early Sun night. After midnight, expect
storms to decrease in strength and be more confined to the Lake
Cumberland region. For Mon, will keep 20-30% chance POPs in the
southeast CWA which may or may not pan out depending on the exact
location of the front and left over showers/t-storms. Temps will be
tricky to nail down Sun night and Mon depending on the exact front
position and clearing of clouds from NW to SE. Will go with a
decent gradient of highs/lows for the Sun night/Mon time
period. Looks like lows Sun night should bottom out in the mid 60s
north to lower 70s south. Highs on Monday should range from the
upper 80s to around 90 north to lower 80s southeast.
Sfc high pressure will settle in for Tues and most of Wed keeping
conditions dry with low humidity. Seasonal temps will prevail in
the upper 80s and lower 90s for highs both days. With mostly clear
skies, low temps will bottom out in the 60s.
By late Wed, the left over boundary from early in the week, will
transition to more of an inverted trough forecast to move back north
into our region by Thurs. Along with this weak boundary, an upper
low will dive south into the Great Lakes region with an upper level
shortwave around its periphery making its way into the Ohio Valley.
Therefore, will continue 30% POPs for Thurs.
For Fri and into the weekend, long range models diverge on how far
south the upper low will travel and to what degree of strength it
will have. At this point, at least some troughing and a cold front
look possible toward Thurs night/Fri time frame. Thus will keep low
POPs going with cooler temps (mid 80s) in store for the weekend.
&&
.Aviation (12Z TAF Issuance)...
Issued at 648 AM EDT Sat Aug 4 2012
Isolated to scattered showers/storms around BWG and LEX early this
morning will continue to push northeast as a weak low-level jet
remains overhead. Isolated cells are moving away from BWG, while
thunderstorms will be in the vicinity of LEX for a little longer
this morning. Could see cigs drop at LEX too if the storms move
directly overhead. Storm coverage should decrease as the low-level
jet relaxes.
Winds will become south-southwesterly and increase between 10 and 15
mph, with gusts 20-25 mph by this afternoon. Diurnal Cu will develop
once again, with storm chances increasing during peak heating. A
weak wave across Missouri this morning is initiating convection
across the mid Mississippi Valley. This activity should push east,
which could mean slightly greater areal storm coverage later this
afternoon. Will continue VCTS and a CB group in the TAFs for this.
Overnight, another low-level jet will strengthen overhead, with
borderline LLWS setting up across the area starting around 06Z. At
the same time, storms could develop during the pre-dawn hours along
the Ohio River. At this time, will not mention LLWS, but will
include VCTS at SDF for the early morning storm chance.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
KY...NONE.
$$
Mesoscale........13
Short Term.......MJP
Long Term........AMS
Aviation.........MJP
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
933 AM CDT SAT AUG 4 2012
.UPDATE...
SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER
ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS
MORNING.
&&
.SHORT TERM...
THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING
THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW
AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS
SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES
PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND
THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS
ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW...
BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A
LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER.
.PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/
AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 40 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 50 10 10 0
ASX 81 58 76 56 / 50 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...EOM
LONG TERM....GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS DULUTH MN
631 AM CDT SAT AUG 4 2012
.AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
&&
.PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 77 55 75 55 / 20 20 10 0
INL 75 47 76 56 / 60 40 10 0
BRD 76 55 76 55 / 20 10 10 0
HYR 79 54 75 53 / 40 10 10 0
ASX 81 58 76 56 / 40 10 10 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1030 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING
ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH
LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL
CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN
FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW
TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO
BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT
ALL.
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z.
FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK
FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE
BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST
IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR
CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL
LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING
CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR
DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A
COUPLE OF HOURS BEFORE SUNRISE.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY
41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY.
JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT
OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE
CAROLINAS.
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
716 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...ANY LIGHT FOG AROUND WILL QUICKLY DISSIPATE BY 1230Z.
FAIRLY TYPICAL SUMMER DAY WITH TCU`S ALREADY LURKING OFFSHORE. LOOK
FOR ISOLATED/SCATTERED CONVECTION ALONG THE SEA BREEZE
BOUNDARY...BEGINNING NEAR THE COAST AROUND 16Z. LFC`S ARE THE LOWEST
IN PENDER COUNTY...SO THAT MAY BE THE INITIATION AREA FOR
CONVECTION. SOUTHEAST FLOW THROUGH 500 MB WILL GIVE US A TROPICAL
LIKE ENVIRONMENT WITH LOW BASED CU AND GREAT VISIBILITY. ANY ONGOING
CONVECTION LATE THIS AFTERNOON WILL LIKELY DISSIPATE BY 22-23Z FOR
DIURNAL REASONS. LIGHT WINDS OVERNIGHT WITH POSSIBLE LIGHT FOG A
COUPLE OF HOURS BEFORE SUNRISE.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
701 AM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT MVFR AND/OR IFR VSBYS FROM BR/FG DURING THE
08Z-13Z TIME FRAME. FLO AND/OR LBT TERMINALS WILL HAVE THE GREATER
POTENTIAL TO OBSERVE PREVAILING BR/FG...WHEREAS THE COASTAL
TERMINALS WILL INDICATE TEMPO MVFR VSBYS. COULD OBSERVE A SUB-1000
FT CLOUD DECK ALONG THE COASTAL TERMS WITHIN A 4 HR WINDOW
SURROUNDING SUNRISE. BY MID-MORNING...ANY RESIDUAL BR SHOULD
DISSIPATE...LEAVING VFR CONDITIONS FOR THE REMAINDER OF THE DAY. THE
PROB OF THUNDERSTORMS REMAINS ON THE LOW SIDE...BUT ENOUGH
CONFIDENCE TO MENTION VCTS AT ALL TERMINALS FROM MIDDAY THROUGH
EARLY THIS EVENING. PREVAILING SE-S WINDS AT 5 TO 10 KT
EXPECTED...UP TO 15 KT AT THE COASTAL TERMINALS.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DCH/MRR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
656 AM EDT SAT AUG 4 2012
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE EAST THROUGH THE WEEKEND. A
COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND TUESDAY BUT WILL
STALL AND WEAKEN WEST OF THE AREA WEDNESDAY THROUGH LATE NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 650 AM SATURDAY...PER EARLIER RUNS OF THE RAP MODEL AND THE
06Z NAM...SCATTERED SHOWERS AND A FEW TSTMS HAVE DEVELOPED IN AN
AREA OF SURFACE MOISTURE CONVERGENCE AND INSTABILITY NEAR THE
COAST AND HAVE MOVED INLAND. HAVE RAISED POPS TO CHC OVER ROUGHLY
THE EASTERN THIRD OR SO OF THE CWA. RAP INDICATES THESE SHOWERS
WILL AROUND FOR ALOT OF MORNING...WITH ADDITIONAL ISOLATED SHOWERS
AND TSTMS THIS AFTERNOON WITH THE SEA BREEZE. NO CHANGES TO
FORECAST TEMPERATURES MAINLY IN THE UPPER 80S TO AROUND 90 TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SUNDAY/...
AS OF 3 AM SATURDAY...THE COMBINATION OF A MOIST ONSHORE FLOW AND
SOME WEAK MID-LEVEL VORTICITY MAY LEAD TO A REPEAT OF THIS MORNING
WITH A FEW SHOWERS ALONG THE COAST IN THE OVERNIGHT HOURS AND WILL
HAVE A SLIGHT CHC POP. OTHERWISE...A PARTLY CLOUDY WARM AND MUGGY
NIGHT WITH MIN TEMPS IN THE 73 TO 78 DEGREE RANGE.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...LONG TERM MODELS STILL IN GENERALLY GOOD
AGREEMENT ON SYNOPTIC REGIME THROUGH THE COMING WEEK. BERMUDA HIGH
WILL REMAIN SOUTH AND EAST OF THE REGION...WHILE BROAD TROUGH EXISTS
ACROSS EASTERN HALF OF CONUS. FLOW WILL REMAIN SOUTHWESTERLY...
SUPPLYING E NC WITH WARM AND HUMID CONDITIONS...WHILE WEAK
SHORTWAVES AND STATIONARY FRONT ACROSS CENTRAL NC BRINGS CHANCES FOR
CONVECTIVE ACTIVITY EACH DAY. BEST CHANCES FOR THUNDERSTORMS WILL BE
IN THE AFTERNOON HOURS...THOUGH RAIN CHANCES MAY LINGER THROUGH THE
EVENING HOURS. BEST CHANCES FOR WIDESPREAD RAIN AND STORMS WILL BE
AROUND MID TO LATE WEEK TIME FRAME.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 7 AM SAT...SOME MVFR FOG HAS DEVELOPED AT ALL OF THE TAF
SITES AND VSBY HAS BEEN BOUNCING UP AND DOWN FOR THE PAST COUPLE
OF HOURS. THIS FOG SHOULD DISSIPATE BY ABOUT 13Z WITH ANOTHER
ROUND OF ISOLATED DIURNAL CONVECTION EXPECTED AGAIN IN THE
AFTERNOON. SIMILAR PATTERN EXPECTED TONIGHT WITH A FEW SHOWERS
DEVELOPING NEAR THE COAST...BUT OVERALL MVFR CONDITIONS EXPECTED
WITH SOME PATCHY FOG TOWARD MORNING ON SUNDAY.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...MAINLY VFR CONDITIONS WILL PREVAIL...THOUGH
AS IS THE CASE MOST EVENING...SOME REDUCTIONS TO MVFR/IFR POSSIBLE
LATE AS RADIATION FOG/LOW STRATUS DEVELOPS...ESP IN AREAS THAT
RECEIVE RAINFALL. SCT MAINLY AFTERNOON THUNDERSTORMS WILL BRING
TEMPO REDUCTIONS IN VSBYS THROUGH THE COMING WEEK.
&&
.MARINE...
/SHORT TERM TODAY AND TONIGHT/...
AS OF 7 AM SATURDAY...CURRENT BUOY OBSERVATIONS CONTINUE TO
INDICATE S/SW WINDS OF 12 KNOTS OR LESS WITH SEAS 2 TO 3 FEET WITH
A 7 TO 8 SECOND SWELL COMPONENT. A FEW SHOWERS MOVING ALONG THE
COAST MAY BRIEFLY CAUSE SOME GUSTINESS TO ABOUT 18 KNOTS OR SO. S/SW
WINDS WILL CONTINUE TO CIRCULATE AROUND HIGH PRESSURE TO THE EAST
TODAY AND TONIGHT WITH FRONTAL BOUNDARY REMAINING WELL OFF TO THE
WEST IN THE OHIO VALLEY. THIS WILL LEAD TO S/SW WINDS 10 TO 15
KNOTS WITH SEAS 2 TO 3 FEET THROUGH TONIGHT.
/LONG TERM SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SATURDAY...SOUTHWEST FLOW WILL CONTINUE THROUGH THE
LONG TERM...WITH WINDS GENERALLY 10 TO 15 KNOTS OVER THE WATERS...
AND AROUND 10 KT OVER THE SOUNDS. SEAS WILL REMAIN IN THE 3 TO 4 FT
RANGE ACROSS OUTER WATERS WITH 2 TO 3 FEET NEARSHORE. THERE WILL BE
CHANCES FOR THUNDERSHOWERS THROUGH THE COMING WEEK AS A COOL FRONT
AND TROUGH SAGS INTO CENTRAL AND EASTERN NC AND STALLS OUT NEARBY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
637 AM EDT SAT AUG 4 2012
.SYNOPSIS...
SCATTERED SHOWERS AND A POSSIBLE THUNDERSTORM WILL OCCUR TODAY AS
LOW LEVEL MOISTURE INCREASES OVER THE AREA. MORE ACTIVE WEATHER
WILL BEGIN WHEN A STRONG COLD FRONT WILL INTERACT WITH AN UPPER
LEVEL DISTURBANCE TO BRING SHOWERS AND THUNDERSTORMS SATURDAY
NIGHT INTO SUNDAY. THE FRONT WILL PUSH EAST OF THE AREA SUNDAY
NIGHT INTO MONDAY...ALLOWING HIGH PRESSURE AND DRIER AIR TO BUILD
INTO THE AREA. NEAR TO SLIGHTLY ABOVE NORMAL TEMPERATURES CAN
THEN BE EXPECTED DURING THE FIRST PART OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
INCREASING SHOWER ACTIVITY IN AMPLE LL MOISTURE AND INCREASING
INSTABILITY THROUGH TODAY. HRRR SEEMS TO HAVE A HANDLE ON CURRENT
ACTIVITY. COVERAGE NOT EXPECTED TO BE WIDESPREAD...SO HAVE OPTED
FOR CHANCE SHRA WITH ISOLD THUNDER THIS MORNING...AND SCT TSTMS
THIS AFTERNOON. WITH LACK OF ORGANIZED SURFACE OR UPPER AIR
FEATURE...EXPECTATION IS STILL THAT OF UNORGANIZED CONVECTION.
WITH LOW LEVEL CLOUDS...HAVE BROUGHT HIGH TEMPERATURES DOWN IN
ESPECIALLY THE SOUTHERN HALF OF THE AREA. WITH EXPECTANT CLOUD
COVER TODAY...NO HEAT ADVISORY CRITERIA MET WITH SLIGHTLY
LOWERED TEMPERATURES. WILL STILL KEEP MENTION IN THE HWO AS VALUES
DO APPROACH 100 DEGREES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SOME TIMING DIFFERENCES WITH THE MAIN EXPECTATION OF CONVECTION
AND SUBSEQUENT FRONTAL PASSAGE...WITH THE GFS A LITTLE FASTER THAN
BOTH THE NAM AND ECMWF. HAVE OPTED FOR THE TIMING OF THE LATTER
TWO MODELS. EARLY PART OF SAT EVENING CONTINUES FAIRLY
DISORGANIZED CONVECTION...WITH THE MORE ORGANIZED DYNAMICALLY
DRIVEN ACTIVITY TO BEGIN AFTER 00-06Z TIMEFRAME IN THE ILN AREA. AS
THE S/WV DIGS INTO THE UPR MS VALLEY AND APPROACHING WESTERN
IN...SOUTHERLY LL FLOW CONTINUES TO PUMP VERY MOIST AIR INTO THE
REGION. IN ADDITION TO CONCERN FOR SEVERE WITH THE PRE FRONTAL
ACTIVITY...THERE STILL IS POTENTIAL FOR MCS AHEAD OF THIS WITH THE
DEVELOPMENT OF A 40 KT+ LLJ (SLIGHTLY WEAKER IN THE ECMWF BUT
STILL ENHANCED) AND SIGNIFICANT MOISTURE TRANSPORT. WHILE THERE
ISNT STRONG EVIDENCE OF BACK BUILDING STORMS...WARM CLOUD DEPTHS
OF NEAR 4500M AND PW VALUES BETWEEN 2.25-2.5 INCHES WILL MAKE FOR
POTENTIAL OF VERY HIGH RAINFALL RATES.
WITH ENHANCED LL JET AND INCREASING DYNAMICS IN ADDITION TO
RESPECTIBLE ML CAPE...POTENTIAL FOR DAMAGING WINDS...WTH
POSSIBILITY OF LARGE HAIL. FIRST SHOT OF CONVECTION/POTENTIAL MCS
TO EXIT THE AREA BEFORE IN THE 15Z TIMEFRAME...AND THEN STILL
SEVERE POTENTIAL AHEAD OF THE FRONT IN THE AFTERNOON DEPENDING ON
HOW WORKED OVER THE AIRMASS IS AFTER PASSAGE OF MORNING CONVECTION.
HAVE SLOWED DOWN THE TIMING OF THIS CONVECTION TO NOT EXIT THE
AREA UNTIL AFTER 00Z...WTH PRECIP LINGERING LONGEST IN THE SE.
WITH AMPLE CLOUDS HAVE CONTINUED TO KEEP TEMPS BELOW 90 FOR
SUNDAY. FOR SUN NIGHT SKIES TO BEGIN CLEARING IN THE WEST WITH
TEMPS DROPPING TO UPR 50S HERE RANGING TO UP 60S SOUTHAST. DRY
CONDITIONS AND NEAR NORMAL TEMPERATURES FOR MONDAY AND TUE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
THE COLD FRONT AND ALL ASSOCIATED PRECIPITATION WILL SHIFT OF TO
OUR EAST MONDAY MORNING AS LOW LEVEL RIDGING BUILDS ACROSS THE
REGION. SKIES WILL BE MOSTLY CLEAR DURING THE DAY WITH CONTINUED
COLD ADVECTION KEEPING TEMPERATURES NEAR...TO JUST BELOW
SEASONABLE VALUES DURING THE DAY.
THE HIGH PRESSURE AREA WILL REMAIN IN CONTROL OF OUR WEATHER THROUGH
TUESDAY NIGHT. THIS WILL KEEP US DRY WITH LIGHT WINDS AND ONLY A FEW
PASSING CLOUDS. TEMPERATURES MONDAY NIGHT WILL BE THE COOLEST OF THE
WEEK...WITH FORECAST LOWS RANGING FROM THE LOW 60S ACROSS THE
SOUTH...TO THE MID 50S ACROSS THE NORTHEAST.
BY WEDNESDAY...TEMPERATURES ALOFT BEGIN TO WARM AS A SHORTWAVE
OVER THE PLAINS PUSHES PART THEIR VERY WARM AIRMASS TOWARD THE
OHIO VALLEY. THIS WILL BRING A REBOUND OF TEMPERATURES BACK TO ABOVE
SEASONABLE VALUES FOR THE MIDDLE OF THE WEEK. THE SHORTWAVE WILL
THEN SLIDE EASTWARD...BRINGING INCREASING CHANCES FOR PRECIPITATION
TOWARD THE END OF THE WEEK.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SCATTERED CONVECTION WILL BE ONGOING TODAY WITH GENERALLY VFR
CONDITIONS OUTSIDE OF THE PASSING SHOWERS. WINDS WILL PICK UP THIS
AFTERNOON AND A COLD FRONT WILL CROSS THE REGION AROUND THIS TIME
TOMORROW. EXPECT WIND SHIFT AT DAYBREAK TOMORROW WITH MORE
PREVALENT THUNDERSTORMS ALONG AND AHEAD OF IT AS THE LOW LEVEL
MOISTURE TRANSPORT KICKS IN OVERNIGHT.
.OUTLOOK...SHOWERS AND THUNDERSTORMS WILL BECOME MORE LIKELY TONIGHT
AND SUNDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...JDR
NEAR TERM...JDR
SHORT TERM...JDR
LONG TERM...LATTO
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1053 AM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A
COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING
CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIS AFTERNOON AND
EVENING.
MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON
HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH
CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND
STORMS.
SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE
OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY
OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING
OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED
PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE
UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT
DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF
THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE
MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS
AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC
FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH
PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE
SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG
AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
CONDITIONS HAVE IMPROVED TO HIGH MVFR/LOW VFR AS LAST OF THE HAZE
CONTINUES TO THIN OUT.
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED LATER TODAY IN AND
AROUND AN THUNDERSTORMS THAT ARE EXPECTED TO DEVELOP THIS
AFTERNOON AND EARLY EVENING...FROM ABOUT 22Z THROUGH 03Z TONIGHT.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-WED...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/CERU/MARTIN
NEAR TERM...LA CORTE/CERU/MARTIN
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
852 AM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
STILL SOME PATCHY LOW CLOUDS AND MAINLY THIN FOG THAT WILL BURN
OFF SMARTLY NOW THAT THE SUN IS UP.
MOIST SOUTHWESTERLY FLOW WILL CONTINUE TO INCREASE AHEAD OF A
COLD FRONT ENTERING THE GR LAKES. THIS WILL PROVIDE INCREASING
CHANCES FOR SHOWERS/STORMS...ESPECIALLY THIA AFTERNOON AND
EVENING.
MUCH OF THE MORNING AND POSSIBLY EVEN INTO THE EARLY AFTERNOON
HOURS SHOULD STAY PARTLY TO MOSTLY SUNNY AND DRY BEFORE WE REACH
CONVECTIVE TEMPS AND START TO COOK UP SCATTERED SHOWERS AND
STORMS.
SREF POPS FOR LATER THIS AFTERNOON AND EVENING RANGE FROM CHANCE
OVER THE NORTH TO CATEGORICAL OVER THE SOUTH...PROBABLY TYPICALLY
OVERDONE BY THE SREF. CURRENT HRRR SHOWING PRECIPITATION FORMING
OVER THE LAUREL HIGHLANDS BY 18Z. THE SREF AND GEFS HAVE INCREASED
PWAT ANOMALIES OVER THE AREA. COUPLE THIS WITH TEMPERATURES IN THE
UPPER 80S AND LOWER 90S...AND DECENT SOUTHEASTERLY FLOW...EXPECT
DIURNAL CONVECTION THIS AFTERNOON AND THROUGH THE FIRST HALF OF
THE EVENING. MODELS SOW IT SPREADING ACROSS CENTRAL PA BEFORE
MOVING EASTWARD. HAVE INCREASED POPS ACCORDINGLY. THESE SHOWERS
AND STORMS SHOULD BE MORE DIURNALLY DRIVEN THAN LARGER SYNOPTIC
FORCING...HOWEVER A 500MB SHORTWAVE COULD ALLOW FOR A STRONG ENOUGH
PV ANOMALY TO CONTINUE SHOWERS WELL INTO THE EVENING OVER THE
SOUTHEAST. ANY PRECIP SHOULD BE DONE BY 06-09Z TONIGHT. PATCHY FOG
AHEAD OF THE FRONT IS AGAIN A POSSIBILITY OVERNIGHT.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
PATCHY IFR AND LOWER CIGS AND VSBYS WILL CONTINUE THROUGH 14Z THIS
MORNING. LOW STRATO CU WILL SPREAD ACROSS THE LOWER SUSQ...AND
OVER THE NW MTNS. THE CENTRAL PA REGION HAS SEEN THE DEVELOPMENT
OF SOME MID LEVEL CLOUDS. LOW STRATOCU COULD STILL SPREAD OUT
THROUGH 15Z...BEFORE IT AND THE PATCHY FOG DISSIPATES.
IFR IS POSSIBLE IN AND AROUND TSRA THIS AFTERNOON AND EARLY
EVENING DUE TO A STRONGER CHANCE FOR CONVECTION...ESPECIALLY
JST...AOO AND ALONG THE LOWER SUSQ TAF SITES FROM 22Z THROUGH 03Z
TONIGHT.
OUTLOOK...
.SAT-SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...
ESPECIALLY SUNDAY AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/CERU/MARTIN
NEAR TERM...LA CORTE/CERU/MARTIN
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
1055 AM CDT SAT AUG 4 2012
UPDATED NEAR-TERM AND AVIATION PORTION FOR 18Z TAF ISSUANCE
.SHORT TERM...TODAY THROUGH SUNDAY.
NEAR-TERM...
HAD TO ADJUST TIMING OF CONVECTION INTO AREA PER EXTRAPOLATION OF
IA CONVECTION AND 04/12Z RUN OF HRRR AND RAP. BEGAN PRECIP EARLIER
THIS AFTERNOON AND ENDING EARLIER IN THE EVENING AS FRONT IS
MOVING A BIT FASTER THAN EARLIER ANTICIPATED. BEST SEVERE
PARAMETERS POINT TO THE SOUTH OF THE FORECAST AREA...BUT SHORT-
TERM MODELS INDICATE SCATTERED CONVECTION AHEAD OF MAIN LINE
BEGINNING BY 19Z IN EAST-CENTRAL WI IN CORRIDOR OF INSTABILITY
AND DIFFERENTIAL HEATING. OTHERWISE...MAIN LINE /HEAVIEST RAIN/
EXPECTED TO MOVE THROUGH THE FORECAST AREA BY ABOUT 00Z.
JKL
PREVIOUS SHORT TERM DISCUSSION...
REGARDLESS OF THE SEVERITY OF THE THUNDERSTORMS WE SHOULD GET A
LINE OF STORMS WITH HEAVY RAIN. PRECIPITABLE WATER VALUES OVER 2
INCHES ARE FORECAST DURING THE LATE AFTERNOON AND EARLY EVENING.
THE FRONT SHOULD BE MOVING QUICK ENOUGH TO PREVENT WIDESPREAD
FLOODING BUT WOULD NOT BE SURPRISED IF THERE ARE SOME 1 TO 2 INCH
PER HOUR RAINFALL RATES AND LOCAL URBAN OR SMALL STREAM FLOODING.
AREA SOUTH OF HIGHWAY 29 IS SO DRY THAT THE RAINFALL IS MUCH
NEEDED. THE FRONT WILL EXIT TONIGHT AND THE RAIN WILL END BY
MIDNIGHT IN MOST PLACES. COOLER AND DRIER AIR WILL ARRIVE
OVERNIGHT AND END THE NEED FOR AIR CONDITIONING FOR AWHILE.
"REAL WISCONSIN" SUMMER WEATHER SHOULD RETURN SUNDAY WITH HIGHS IN
THE 70S...LOW HUMIDITIES AND A NICE BREEZE. IT WILL PROBABLY BE THE
NICEST DAY SINCE JUNE 25TH OVER MUCH OF THE AREA.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT SATURDAY.
THE LATEST MEDIUM RANGE MODELS PLACE THE WESTERN GREAT LAKES REGION
WITHIN NW FLOW ALOFT FOR MUCH OF THE NEXT WEEK. SEVERAL SHORTWAVES
WITHIN THIS NW FLOW COULD IMPACT THE REGION...BUT OUTSIDE OF THE
FIRST WAVE ARRIVING MONDAY NIGHT...MODELS DO NOT HAVE A GOOD HANDLE
OF THESE IMPULSES. COULD SEE ANOTHER WAVE DROP INTO THE AREA
WEDNESDAY INTO WEDNESDAY NIGHT AND ANOTHER LATER IN THE WEEK...BUT
MOISTURE WILL BE LACKING WITH EACH SYSTEM. WILL HAVE TO TAKE A
GENERAL BLEND MID-WEEK ONWARD.
SUNDAY NIGHT INTO MONDAY NIGHT...HIGH PRESSURE WILL MOVE FROM THE
CENTRAL GREAT PLAINS TO THE SOUTHERN GREAT LAKES SUNDAY NIGHT.
WINDS LOOK LIGHT ENOUGH FOR DECOUPLING AND WILL SEE MOSTLY CLEAR
CONDITIONS...SO WILL SIDE ON THE COLD SIDE OF GUIDANCE FOR LOW
TEMPS. ON MONDAY...AN AMPLIFYING NORTHERN STREAM SHORTWAVE WILL
DROP A COOL FRONT INTO LAKE SUPERIOR IN THE AFTERNOON. BUT HIGH
PRESSURE WILL STICK AROUND OUR AREA TO GIVE A MOSTLY SUNNY AND WARM
DAY WITH HIGHS IN THE LOW TO MID 80S. THIS FRONT WILL THEN DROP
ACROSS NORTHERN WISCONSIN AND INTO CENTRAL WISCONSIN MONDAY NIGHT.
HARD TO SAY IF THERE WILL BE ENOUGH MOISTURE FOR PRECIP...BUT
POTENTIAL WILL EXIST SO WILL KEEP A SPOTTY MENTION IN THE FORECAST
FOR NORTHERN WISCONSIN.
REST OF THE FORECAST...THE FRONT WILL FINISH CROSSING CENTRAL AND
NORTHEAST WISCONSIN TUESDAY MORNING BEFORE DEPARTING BY THE
AFTERNOON. NOT TO THRILLED WITH PRECIP CHANCES IN THE MORNING...AS
MID-LEVEL MOISTURE WILL HAVE ALREADY PULLED OUT BY THIS POINT. WILL
REMOVE POPS. TEMPS WILL COOL SLIGHTLY BEHIND THE FRONT TO THE UPPER
70S AND LOWER 80S. HIGH PRESSURE WILL DRIFT ACROSS THE REGION
TUESDAY NIGHT BUT THEN WILL BE ANTICIPATING THE NEXT WAVE SWINGING
ACROSS THE REGION WEDNESDAY INTO WEDNESDAY NIGHT. WILL HAVE SOME
SMALL PRECIP CHANCES OVER THIS PERIOD. MAY HAVE ANOTHER WAVE ARRIVE
FRIDAY INTO SATURDAY...THOUGH AGAIN PRECIP CHANCES LOOK SMALL. WILL
TRY TO REMOVE CHANCES WHERE POSSIBLE UNTIL MODELS GET A BETTER
HANDLE ON THE DETAILS.
&&
.AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF
FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR
CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER
40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST-
CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF
STATE.
JKL
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1003 AM CDT SAT AUG 4 2012
.UPDATE...MAKING CHANGES ON TIMING AS IOWA CONVECTION LOOKS TO BE
OUR SHOW THIS AFTERNOON. HAVE UPPED POPS TO CATEGORICAL AND HAVE
ADDED SEVERE TO THE GRIDS AS WELL. AXIS OF 1000 DCAPE INTO
SOUTHERN WI...WITH WATER VAPOR/RUC COMBO SHOWING SHORTWAVE NE KS
VICINITY SHIFTING NORTHEAST. MID LEVEL LAPSE RATES OF AROUND 7
WITH BUILDING CAPES INTO SRN WI. ONLY THIN CIRRUS TO CONTEND SO
PLENTY OF HEATING. 0-8 KM SHEAR AROUND 50 KNOTS...AND SEEING SOME
40 KNOTS 0-6 KM. 0-1 SHEAR MORE SO- SO...TORNADO THREAT MINIMAL
BUT NON-ZERO. MAIN CONCERN WILL BE FOR DAMAGING WINDS.
PC
&&
.AVIATION/18Z TAFS/...HAVE ADJUSTED TIMING OF CONVECTION BASED ON
TRENDS ACROSS IOWA. LOOKS LIKE AROUND 19Z IN KMSN AND AROUND 21Z
TOWARDS KMKE.
PC
&&
.PREV DISCUSSION... /ISSUED 330 AM CDT SAT AUG 4 2012/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
BIG CONCERN IS IMPACT OF CURRENT LINE OF CONVECTION ON THE EVOLUTION
AND TIMING OF THUNDERSTORMS ACROSS FORECAST AREA LATER TODAY.
SUB-SEVERE WIND REPORTS SINCE 12 MIDNIGHT HAVE INDICATED A WEAKENING
TREND TO THE LINE...SUPPORTED BY REDUCED LIGHTNING ACTIVITY AND A
SLIGHT WARMING OF CLOUD TOPS. LINE WILL REACH NW CWA BETWEEN 245 AM
AND 3AM ON CURRENT PACE.
HRRR AND RAP SUGGEST A RAPID WEAKENING OF CURRENT LINE AS IT MOVES
AWAY FROM MAIN LOW-LEVEL JET AXIS AND INSTABILITY...THEN ALL MODELS
SHOW A RE-FIRING OF CONVECTION ALONG SURFACE FRONT MID-LATE MORNING
FROM WEST CENTRAL WI INTO FAR NE IOWA AS FRONTOGENETIC RESPONSE
INCREASES AHEAD OF TROUGH.
STILL FEEL BEST OPPORTUNITY FOR STRONG/SEVERE IN CWA DURING THE LATE
AFTERNOON INTO THIS EVENING WITH ENHANCED FORCING AND 0 TO 6KM SHEAR
INCREASING TO 30 TO 40 KTS AHEAD OF COLD FRONT AND POSITIVE-TILT 500
MB TROUGH AS IT SWINGS TO A MORE NEUTRAL POSITION WHILE CROSSING THE
WESTERN GREAT LAKES TONIGHT. FORCING FOR ASCENT WILL BE AIDED BY
UPPER LEVEL DIVERGENCE OF RRQ OF 100-110KT 250 MB JET MAX LIFTING
ACROSS WRN GREAT LAKES REGION DURING THE LATE AFTERNOON AND EVENING.
IF CLOUD DEBRIS DOESN/T OVERLY INHIBIT DAYTIME HEATING...SURFACE
BASED CAPE OVER CWA RISES TO AROUND 1600 J/KG...COMPUTED LIFTED
INDICES OF -5 TO -7...PRECIPITABLE WATER VALUES OF 1.8 TO 2 INCHES.
FEEL CLOUDS WILL THIN ENOUGH AND WARM ADVECTION AHEAD OF FRONT WILL
BRING HIGH TEMPERATURES IN THE LOW 90S INLAND...WITH SOUTHERLY WINDS
TURNING INSHORE ENOUGH TO KEEP LAKESHORE AREAS IN THE MID-UPPER 80S.
BUFKIT SOUNDINGS SHOW WELL MIXED BOUNDARY LAYER BY LATE
AFTERNOON...WITH DRY SUB-CLOUD LAYER ENHANCING POTENTIAL FOR
DAMAGING WINDS REFLECTED IN FORECAST DOWNDRAFT CAPE OF 1500 TO 2000
J/KG.
PRECIPITATION ENDS IN THE EAST WITH TROUGH PASSAGE AROUND 06Z WITH
DRIER AIR POURING IN ON NORTHWEST WINDS AS HIGH BUILDS IN FROM THE
WEST.
SUNDAY AND MONDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
HIGH PRESSURE TO MOVE IN BEHIND THE COLD FRONT FOR SUNDAY AND
MONDAY...BRINGING PLEASANT WEATHER TO SOUTHERN WISCONSIN. MAY SEE A
FEW LINGERING CLOUDS NORTH SUNDAY AS THE UPPER TROUGH AXIS SWINGS
THROUGH...WITH SUNNY SKIES ACROSS THE FORECAST AREA MONDAY. COOLER
AIR BEHIND THE DEPARTING SYSTEM WILL RETURN TEMPERATURES TO NEAR
NORMAL SUNDAY...WARMING BACK UP JUST A BIT MONDAY.
TUESDAY AND WEDNESDAY....FORECAST CONFIDENCE...MEDIUM
MAY SEE A WEAK WAVE OR TWO SLIDE THROUGH TUESDAY AND WEDNESDAY...BUT
OVERALL PRECIP CHANCES TOO LOW FOR POPS AT THIS TIME. WARM ADVECTION
IS EXPECTED INTO THE AREA WITH UPPER RIDGE TO THE WEST...SO SHOULD
SEE TEMPS RUN A FEW DEGREES ABOVE NORMAL.
THURSDAY AND FRIDAY...FORECAST CONFIDENCE...MEDIUM
MODELS ADVERTISING A STRONGER WAVE FOR THURSDAY...SO WENT WITH
CHANCE POPS MOST PLACES. LOOKS QUIETER FOR FRIDAY BEHIND THE SYSTEM.
NO BIG CHANGE EXPECTED IN TEMPS THROUGH THE END OF THE WORK
WEEK...WITH 80S CONTINUING.
AVIATION/12Z TAFS/...
WILL ADJUST TAFS FOR MVFR/IFR FOG IN THE NEAR TERM...THEN VFR UNTIL
EXPECTED THUNDERSTORMS BRING MVFR CONDITIONS AND GUSTY WINDS. 000Z
AND RAPID REFRESH MODELS SUPPORT KEEPING LATE AFTERNOON/EARLY
EVENING TIMING FOR THUNDERSTORMS THAT IS IN CURRENT FORECAST.
NORTHWEST WINDS KEEP BOUNDARY LAYER MIXED...WITH DRY AIR MOVING IN
BEHIND COLD FRONT KEEPING OUT ANY CHANCE OF POST-FRONTAL LOW
CLOUDS/FOG AT THIS TIME.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...REM
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
640 AM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...
640 AM CDT SAT AUG 4 2012
WAVES OF CONVECTION PASSING THROUGH REGION AHEAD OF APPROACHING
UPPER LOW HAVE BEEN A BIT PROBLEMATIC EARLY THIS MORNING. GENERALLY
VFR CONDITIONS PREVAIL EXCEPT IN AREAS OF STRONGER CONVECTION SO
TRIED TO TIME BETTER THUNDERSTORM WINDOWS IN SHORT TERM.
OFF AND ON ACTIVITY LIKELY TO CONTINUE THROUGH MOST OF THE MORNING
THOUGH AND AS UPPER LOW GETS EVEN CLOSER...ASSOCIATED COLD FRONT
WILL BEGIN LIMITING STORM CHANCES...PUSHING THREAT EAST. MESOSCALE
MODELS STILL HINT AT STRONGER STORMS REFORMING THIS AFTERNOON MAINLY
SOUTH AND SOUTHEAST OF TAF SITES SO EXPECT GENERALLY DRYING TREND BY
EVENING AS NORTHWEST WINDS TAKE OVER. SHOULD ALSO SEE CLEARING
TONIGHT AS HIGH PRESSURE BUILDS IN BUT NORTHWEST WINDS BEHIND SYSTEM
SHOULD KEEP THINGS MIXED AND PREVENT ANY FOG.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....SHEA
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 AM MDT SAT AUG 4 2012
.AVIATION...SMALL PATCH OF MVFR STRATUS NEAR KCOS AS OF 17Z WILL
DISSIPATE OVER THE NEXT HOUR AND WON`T INCLUDE IN THE NEW 18Z TAF.
ISOLATED TO SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS
THIS AFTERNOON...THOUGH STORMS SHOULD DISSIPATE AS THEY MOVE OFF
THE MTNS AND WILL LIKELY NOT IMPACT KCOS AND KPUB...AS MOISTURE
AND INSTABILITY ON THE PLAINS IS LIMITED. SLIGHTLY BETTER ODDS OF
A STORM AT KALS...THOUGH CHANCE IS STILL TOO LOW TO MENTION IN THE
TAF AT THIS POINT. TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY
AFTER SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH
THE NIGHT.
&&
.PREV DISCUSSION... /ISSUED 408 AM MDT SAT AUG 4 2012/
SHORT TERM...
(TODAY AND TONIGHT)
COLD FRONT CURRENTLY RACING THROUGH SOUTHEAST CO AND SHOULD REACH
THE SOUTHERN BORDER BY 12-13Z. WIND GUSTS BEHIND THE FRONT HAVE
BEEN IN THE 40-45 KT RANGE SO FAR THIS MORNING ACROSS PORTIONS OF
SOUTHERN EL PASO AND PUEBLO COUNTIES. HRRR AND LOCAL 4KM WRF SHOW
POTENTIAL FOR SOME ISOLATED SHOWERS TO DEVELOP BEHIND THE FRONT
ACROSS THE SOUTHEAST PLAINS EARLY THIS MORNING AS IT ENCOUNTERS
HIGHER DEW POINTS ACROSS THE FAR SOUTHEAST PLAINS. WILL MAINTAIN
SOME 20 POPS THROUGH 15Z FOR THE FAR SOUTHERN AND EASTERN PORTIONS
OF THE AREA. OTHERWISE...REMAINDER OF THE AREA SHOULD REMAIN DRY
THROUGH THE EARLY MORNING HOURS. NAM ALSO DEVELOPS SOME MVFR STRATUS
EARLY THIS MORNING ALONG THE CREST OF THE PALMER DIVIDE.
GUSTY NORTH WINDS WILL CONTINUE THROUGH THE MORNING BEFORE SWINGING
AROUND FROM THE EAST TO SOUTHEAST DURING THE AFTERNOON ACROSS THE
PLAINS. DEW POINTS BEHIND THE FRONT DROP INTO THE 40S BY
AFTERNOON...AND MODEL SOUNDINGS SHOW A STOUT CAPPING INVERSION WHICH
SHOULD HINDER AFTERNOON THUNDERSTORM DEVELOPMENT ACROSS THE PLAINS.
MEANWHILE...MONSOON PLUME HAS BEEN SHUNTED EVEN FARTHER SOUTH
TODAY...WITH PRECIP WATERS ABOVE 100% OF NORMAL NOW PUSHED TO ALONG
THE SRN CO BORDER AND INTO NEW MEXICO. STILL ENOUGH
MOISTURE PRESENT FOR ISOLATED TO SCATTERED THUNDERSTORMS ACROSS THE
SOUTHERN MTS TODAY...THOUGH GREATEST COVERAGE SHOULD BE NEAR THE NM
BORDER. HAVE DECREASED POPS FARTHER NORTH WHERE SOUNDINGS LOOK QUITE DRY.
LATEST MODELS ARE TRENDING PRECIPITATION SOUTHWARD TO ALONG THE
FRONTAL BOUNDARY ACROSS NORTHEAST NEW MEXICO...AND HAVE CUT BACK POPS
TO ISOLATED ALONG THE NRN SLOPES OF THE RATON RIDGE. GUIDANCE
TEMPERATURES TODAY STILL SHOW QUITE A DISCREPANCY...WITH MAV RUNNING
AROUND 5 TO 10 DEGREES COOLER THAN MET ACROSS THE PLAINS. HAVE
GENERALLY SPLIT THE DIFFERENCE FOR NOW. MTN AREAS SHOULD SEE TEMPS
SIMILAR TO A DEGREE OR TWO COOLER THAN THOSE OF YESTERDAY.
TONIGHT...CONVECTION SHOULD DIMINISH QUICKLY THIS EVENING WITH LOSS
OF HEATING. WILL MAINTAIN SOME ISOLATED POPS ACROSS THE SRN MTS
UNTIL 06Z...THEN REMOVE POPS THERE-AFTER. MIN TEMPS TONIGHT SHOULD
BE COOLER ACROSS THE PLAINS AND HAVE CUT THEM BACK A COUPLE
DEGREES. -KT
LONG TERM...
(SUNDAY THROUGH SATURDAY)
THE EXTENDED FORECAST WILL BE DOMINATED BY HIGH PRESSURE OVER THE
FOUR CORNERS REGION WITH VERY HOT CONDITIONS FOR THE LOWER
ELEVATIONS AND MOUNTAIN THUNDERSTORMS. HIGH PRESSURE BEGINS TO
BUILD NORTHWARD SUNDAY MORNING AS AN UPPER LEVEL TROUGH MOVES EAST
ACROSS THE GREAT LAKES. A WEAK DISTURBANCE CAUGHT UNDER THE
BUILDING HIGH WILL DRIFT NEAR THE COLORADO NEW MEXICO BORDER AND
HELP GENERATE SHOWER AND THUNDERSTORM ACTIVITY...ESPECIALLY OVER
THE SAN JUAN AND SOUTHERN SANGRE DE CRISTO RANGES. MODELS KEEP
THIS ACTIVITY GOING THROUGH SUNDAY NIGHT INTO MONDAY MORNING. HIGH
PRESSURE CONTINUES TO BUILD ACROSS THE REGION ON MONDAY WITH
AFTERNOON THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS. FLOW ALOFT
WILL REMAIN NORTHWESTERLY AROUND THE STRENGTHENING HIGH WHICH WILL
HELP PUSH CONVECTION INTO THE I-25 CORRIDOR. THIS ACTIVITY IS
FORECAST TO DIMINISH THROUGH THE EVENING HOURS. TEMPERATURES ON
SUNDAY WILL START TO WARM WITH UPPER 80S TO LOWER 90S FOR THE
PLAINS. BY MONDAY...HIGHS WILL BE PUSHING INTO THE UPPER 90S TO
LOWER 100S FOR THE PLAINS.
TUESDAY THROUGH SATURDAY...HIGH PRESSURE WILL ANCHOR ITSELF OVER
THE FOUR CORNERS AREA AND DOMINATE THE WEATHER. THIS WILL HELP
KEEP TEMPERATURES WARM THROUGH THE EXTENDED WITH UPPER 90S TO
LOWER 100S EXPECTED FOR THE PLAINS. WITH THE MONSOON MOISTURE TAP
WELL TO THE WEST AND DRIER AIR ACROSS COLORADO...THUNDERSTORM
COVERAGE IS FORECAST TO BE MINIMAL AND DIURNALLY DRIVEN.
WITH WEAK FLOW ALOFT...ANY THUNDERSTORMS THAT DO DEVELOP WILL
REMAIN ANCHORED TO THE MOUNTAINS. 88
AVIATION...
MVFR STRATUS WILL DEVELOP ALONG THE CREST OF THE PALMER DIVIDE AND
NORTH SIDE OF THE RATON RIDGE THIS MORNING. NORTH WINDS GUSTING TO
30-40 KTS WILL CONTINUE AT KPUB AND KCOS THROUGH 12-15Z BEFORE WINDS
DECREASE AND SWING AROUND FROM THE EAST TO SOUTHEAST BY THE
AFTERNOON. STRATUS SHOULD DISSIPATE BY LATE MORNING...AND STAY
PREDOMINANTLY TO THE NORTH OF THE KCOS TERMINAL. ISOLATED TO
SCATTERED -TSRA WILL DEVELOP ACROSS THE MOUNTAINS DURING THE
AFTERNOON...THOUGH SHOULD DISSIPATE AS THEY MOVE OFF THE MTS AND
SHOULD NOT IMPACT KCOS AND KPUB. KALS WILL HAVE A SLIGHTLY BETTER
CHANCE OF SEEING A PASSING -TSRA IN THE AFTERNOON...THOUGH ODDS TOO
LOW AT THIS POINT TO INCLUDE IN TAF AS LOW LEVEL MOISTURE SHOULD BE
LESS TODAY. -TSRA AND CLOUD COVER SHOULD DECREASE QUICKLY AFTER
SUNSET WITH VFR CONDITIONS AND LIGHT WINDS EXPECTED THROUGH THE
NIGHT. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
10/27
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 PM EDT SAT AUG 4 2012
.SHORT TERM...(TONIGHT-MONDAY NIGHT)
THE LATEST SURFACE ANALYSIS SHOWED A TROUGH EXTENDING SOUTH OF A
WEAK LOW PRESSURE AREA CENTERED ALONG IT NORTHWEST OF THE BAHAMAS
OR EAST SOUTHEAST OF FT PIERCE. LIGHT WNW FLOW ACROSS THE LOCAL
AREA TO ITS SOUTHWEST COMBINED WITH THE ATLANTIC SEA BREEZE HAS
ALREADY LED TO A FEW SHOWERS DEVELOPING ALONG IT OVER PALM BEACH
COUNTY NEAR THE COAST AND FARTHER SOUTH ALONG THE EAST COAST AREAS.
LOCAL WRF AND HRRR MODEL REFLECTIVITIES SEEM TO BE INITIALIZING
WELL WITH THIS PATTERN AND GENERALLY INDICATE THIS ACTIVITY
INCREASING IN COVERAGE THROUGH THE COURSE OF THE AFTERNOON TODAY
AS THE ATL SEA BREEZE CONTINUES TO MAKE ITS PUSH INLAND. THIS
COMBINED WITH THE ACTIVITY FROM YESTERDAY COULD GENERATE MORE
FLOODING CONCERNS DEPENDING ON WHERE THE HEAVIEST ACTIVITY
BECOMES CONCENTRATED AS THE DAY PROGRESSES. THE MORNING UPPER AIR
SOUNDING AT MIAMI ALONG WITH THE LATEST SATELLITE DERIVED 500 MB
TEMPERATURES INDICATE A MORE STABLE ENVIRONMENT COMPARED TO
YESTERDAY AND WITH THE BEST INSTABILITY OR COOLER MID /UPPER-LEVEL
AIR NOW TO THE WEST OF THE FL PENINSULA CLOSER TO THE BROAD UPPER
LOW CENTER OVER THE GULF OF MEXICO. THEREFORE...THE MAIN IMPACTS
FROM ANY STRONG STORMS THAT DO DEVELOP SHOULD REMAIN SUB-SEVERE
AND MAINLY ASSOCIATED WITH STRONG WIND GUSTS UP TO 50 MPH.
THE LATEST NUMERICAL MODEL GUIDANCE HAS INITIALIZED WELL WITH THIS
SURFACE TROUGH AND LOW JUST EAST OF THE LOCAL AREA AND GENERALLY
INDICATES THIS FEATURE CONTINUING WESTWARD OVER SOUTH FLORIDA
THROUGH TONIGHT...THEN WEST OF THE FL PENINSULA SUNDAY THROUGH
MONDAY. IN ITS WAKE...MOIST SOUTHEAST FLOW WILL BE EXPECTED AS THE
AFOREMENTIONED SURFACE TROUGH/UPPER LOW CONTINUES WEST AND AWAY FROM
THE FL PENINSULA AND ERNESTO CONTINUES ITS WESTWARD TRACK ACROSS THE
CARIBBEAN SEA AND PASSES THE LOCAL AREA TO THE SOUTH SUNDAY THROUGH
MONDAY NIGHT. MODERATE EAST AND SOUTHEAST FLOW THROUGH THE LOW
LEVELS DUE TO A SLIGHTLY ENHANCED GRADIENT BETWEEN ERNESTO TO THE
SOUTH AND THE SUBTROPICAL RIDGE TO THE NORTH COMBINED WITH
PRECIPITABLE WATER VALUES AROUND THE TWO INCH MARK WILL KEEP THE
RAIN CHANCES IN THE FORECAST THROUGH THE PERIOD.
.LONG TERM (TUESDAY-FRIDAY)...
ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING TUE AND
LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN FROM THE
EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH EVEN A LITTLE
BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID WEEK. WITH THE
EASTERLY FLOW IN PLACE...SHOWERS/TSTMS THAT DEVELOP DURING THIS TIME
SHOULD HAVE THE BEST CHANCE OF FORMING OVER THE INLAND AND WESTERN
LOCATIONS EACH AFTERNOON. MOISTURE BEGINS TO INCREASE ACROSS THE
AREA BY FRI.
&&
.MARINE...
A TROUGH EXTENDING SOUTH OF A WEAK LOW PRESSURE AREA CENTERED
NORTH OF THE BAHAMAS OR EAST SOUTHEAST OF CAPE CANAVERAL IS
FORECAST TO TRACK WEST AND NORTHWEST ACROSS THE FLORIDA PENINSULA
THROUGH TONIGHT. SCATTERED SHOWER AND STORMS ASSOCIATED WITH THIS
FEATURE WILL LEAD TO PERIODS WITH REDUCED VISIBILITIES ALONG WITH
LOCALLY HIGHER WINDS AND SEAS...ESPECIALLY ACROSS THE ATLANTIC
WATERS. SUNDAY THROUGH THE MID WEEK PERIOD...MODERATE EASTERLY
WINDS AND SEAS WILL BE ANTICIPATED AS TROPICAL STORM ERNESTO
PASSES SOUTH OF THE MARINE AREA ACROSS THE CARIBBEAN SEA. FOR THE
LATEST INFORMATION REGARDING ERNESTO...REFER TO THE LATEST
FORECASTS AND ADVISORIES ISSUED BY THE NATIONAL HURRICANE CENTER.
&&
.FIRE WEATHER...
NO CONCERNS THROUGH THE WEEKEND AND INTO THE UPCOMING WEEK AS PLENTY
OF MOISTURE AND RAIN CHANCES REMAIN IN THE FORECAST.SOME DRIER AIR
WITH MODERATE EASTERLY FLOW APPEARS POSSIBLE THROUGH THE MID-WEEK
PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 88 79 88 / 50 60 40 60
FORT LAUDERDALE 79 90 80 89 / 50 60 40 60
MIAMI 78 89 79 89 / 50 60 40 60
NAPLES 76 92 76 90 / 40 50 40 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS MIAMI FL
147 PM EDT SAT AUG 4 2012
.AVIATION...
SATELLITE AND RADAR SHOW AN AREA OF LOW PRESSURE OFF THE COAST OF
CENTRAL FLORIDA AND MOVING TO THE NORTHWEST. SHOWERS AND
THUNDERSTORMS REMAINED OVER THE LOCAL WATERS AND BAHAMAS. THE SEA
BREEZE BOUNDARIES WERE BEGINNING TO MOVE INLAND...WITH ISOLATED
SHOWERS AND THUNDERSTORMS DEVELOPING ALONG IT. EXPECT ACTIVITY TO
BECOME MORE NUMEROUS OVER THE NEXT COUPLE OF HOURS...BUT MOST OF
THE ACTIVITY MAY BE JUST TO THE WEST OF THE EAST COAST TAF SITES.
SO WILL KEEP VCTS AT THE TAF SITES. KEPT VCSH TONIGHT ACROSS THE
REGION AS THE AREA OF LOW PRESSURE MOVES ACROSS FLORIDA TONIGHT
THROUGH SUNDAY. AT THIS TIME DID NOT CARRY THUNDERSTORMS
OVERNIGHT...BUT THIS WILL NEED TO BE MONITORED. EXPECT NUMEROUS
SHOWERS AND THUNDERSTORMS TO REDEVELOP ACROSS THE REGION ON
SUNDAY...PUSHING TOWARDS KAPF IN THE AFTERNOON. MOSTLY VFR
CONDITIONS WILL CONTINUE...BUT MVFR CIG/VIS ARE POSSIBLE IN AND
AROUND SHOWERS AND THUNDERSTORMS. EAST TO SOUTHEAST WINDS AROUND
10 KNOTS ARE EXPECTED AT THE EAST COAST TAF SITES THIS
AFTERNOON...WITH A WEST TO NORTHWEST WIND AT NAPLES. LIGHT
EASTERLY FLOW IS EXPECTED OVERNIGHT...WITH THE EAST COAST SEA
BREEZE PUSHING BY MID/LATE MORNING.
&&
.PREV DISCUSSION... /ISSUED 724 AM EDT SAT AUG 4 2012/
AVIATION...
A TROPICAL WAVE BETWEEN THE BAHAMAS AND MAINLAND...WHICH EXTENDS
SW OVER N CUBA...WILL SLOWLY MOVE W THROUGH THE PERIOD. THIS
FEATURE WILL SLOWLY MOVE OVER THE SE FLA COAST THIS MORNING AND
WILL MOVE ACROSS S FLA THROUGH THE DAY. SCATTERED SHRA WITH ISOLD
TSRA AT THIS TIME WELL E IN THE ATLC BUT EXPECT SHRA TO DEVELOP BY
LATE MORNING AND POSSIBLE TSRA AS EARLY AS 16Z ALONG THE E COAST.
WILL HAVE VCSH IN E COAST TERMINALS INITIALLY BUT POSSIBLE TSRA BY
16Z. ANY TSRA THAT DEVELOP WILL MOVE SLOWLY SO HEAVY RA AND
POSSIBLE MVFR CIG/VSBY WILL BE POSSIBLE. MODEL GUIDANCE AT THIS
TIME DOES NOT INDICATE MVFR CIG/VSBY AND MODELS PROJECT THE BULK
OF THE SHRA/TSRA TO THE E OF THE WAVE MOVING N ALONG THE FLA E
COAST. HEATING OF THE DAY WILL BE THE MAIN INPUT TO PRECIPITATION.
SFC WINDS ENE < 10 KNOTS BECOMING ESE 10 TO 15 KNOTS AS THE WAVE
MOVES PAST ANY ONE TERMINAL LATER TODAY.
PREV DISCUSSION... /ISSUED 358 AM EDT SAT AUG 4 2012/
.LOCALLY HEAVY RAINFALL POSSIBLE TODAY...
.MODERATE RISK OF RIP CURRENTS ATLANTIC BEACHES...
DISCUSSION...TROPICAL DISTURBANCE OVER THE BAHAMAS HAS A LOW
PROBABILITY OF DEVELOPING PER NHC...AND OUR MAIN CONCERN IS THE
POTENTIAL FOR LOCALLY HEAVY RAINFALL...BUT THEN PERHAPS NOT MUCH?
A CHALLENGING FORECAST INDEED. MODEL CONSENSUS IS FOR THIS AREA OF
DISTURBED WEATHER OVER THE BAHAMAS, ASSOCIATED WITH A BROAD
TROUGH, TO MOVE NORTHWEST AND ACROSS SOUTH FLORIDA THROUGH
TONIGHT...BUT MODELS SHOWS THE BULK OF THE HEAVIER RAINFALL
CONCENTRATING OVER THE LOCAL ATLANTIC WATERS. HOWEVER, SHOWERS ARE
NOW DEVELOPING OVER THE ATLANTIC, ESPECIALLY EAST OF THE UPPER
KEYS. FORECAST SOUNDINGS SHOW A MOIST AND UNSTABLE PROFILE WITH NO
CAPPING...AND WITH PLENTY OF MORNING SUNSHINE/HEATING AND
DEVELOPING INSTABILITY, WILL MAINTAIN THE INHERITED 70% EAST TO
50% GULF COAST. INTERESTING THAT THE HRRR IS IN LINE WITH THE
GFS/ECMWF SHOWING MAX QPF OFFSHORE. STILL BELIEVE MOST AREAS WILL
SEE RAIN ACROSS THE EAST COAST METRO (SO MAINTAINED THE HIGH POPS),
DURATION AND AMOUNT IS OF HIGH UNCERTAINTY.
AS THIS TROUGH PASSES SOUTH FL TO THE NW TONIGHT, AN INCREASING
MOIST SOUTHEASTERLY WIND FLOW WILL DEVELOP SUN-MON. THIS IS
EXPECTED TO LEAD TO CONTINUED UNSETTLED WEATHER CONDITIONS WITH
BOUTS OF NUMEROUS SHOWERS/TSTORMS FOCUSED IN THE AFTERNOON ALL
AREAS (FAST EAST TO WEST MOVEMENT) AND ALONG THE ATLANTIC COAST AT
NIGHT.
THE MAIN CONCERN IS FOR POTENTIAL LOCALIZED HEAVY RAINFALL
ESPECIALLY THIS AFTERNOON AS FCST SOUNDINGS SHOW LITTLE STORM
MOTION...AND ANTECEDENT HEAVY RAINS FROM YESTERDAY. STORM MOTION
INCREASES SUN-MON. AT THIS TIME, THE CONCERN IS FOR LOCALIZED
HEAVIER RAIN AMOUNTS OF 3+" TODAY, WHICH COULD LEAD TO ISOLATED
STREET FLOODING...SIMILAR TO WHAT OCCURRED YESTERDAY WHERE HERE AT
THE OFFICE WE PICKED UP 4.03" OF RAIN...BRINGING OUR YEARLY TOTAL
TO 60.49"! STREET FLOODING COULD OCCUR QUICKER THAN NORMAL IF
HEAVY RAINS DEVELOP OVER AREAS WHICH RECEIVED HEAVY RAINFALL
YESTERDAY.
TS ERNESTO WILL PASS WELL SOUTH OF THE AREA OVER THE CARIB ON
MONDAY. ATLANTIC HIGH PRESSURE WILL BUILD INTO SOUTH FL BEGINNING
TUE AND LASTING THROUGH THE WORK WEEK WITH DRIER AIR MOVING IN
FROM THE EAST. PWATS LOWER TO AROUND 1.5 INCHES WED-THU...WITH
EVEN A LITTLE BIT OF HAZE FROM SAHARAN DUST POSSIBLY MOVING IN MID
WEEK. SO THE FORECAST TREND IS WET THROUGH MONDAY THEN LOWERING
RAIN CHANCES TUE AND BEYOND WITH TSTORMS FOCUSING OVER THE
INTERIOR EACH AFTERNOON. MOISTURE BEGINS TO INCREASE BY FRI.
MARINE...WINDS WILL BE ON THE INCREASE, ESPECIALLY SUN-MON WITH
SEAS INCREASING INTO THE 3-5 FT RANGE. HOWEVER, NO HIGHLIGHTS ARE
NEEDED AT THIS TIME.
FIRE WEATHER...NO CONCERNS AS RELATIVE HUMIDITIES REMAIN
TYPICALLY HIGH.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 88 78 89 79 / 70 50 60 50
FORT LAUDERDALE 88 80 89 79 / 70 50 60 50
MIAMI 89 78 89 79 / 70 50 60 50
NAPLES 91 76 92 77 / 50 30 50 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...85/AG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS LINCOLN IL
341 PM CDT SAT AUG 4 2012
.DISCUSSION...
ISSUED 341 PM CDT SAT AUG 4 2012
COLD FRONT HAS BEEN MOVING A BIT QUICKER TOWARD THE CWA...AND WAS
LOCATED FROM NEAR THE QUAD CITIES SOUTHWEST TO NEAR KANSAS CITY.
WELL-DEFINED MESOSCALE VORTEX FROM CONVECTION IN IOWA HELPED TO
DEVELOPED AN MCS WHICH HAS BEEN ROLLING ACROSS THE NORTHERN THIRD
OF ILLINOIS THIS AFTERNOON. SOME OF THE SOUTHERN FRINGES CONTINUE
TO PUSH ACROSS AREAS FROM CANTON EAST TO EL PASO AT MID AFTERNOON.
INSTABILITY OVER THE AREA PEAKED EARLY THIS AFTERNOON WITH CAPES
AROUND 4000 J/KG...BUT SPC MESOANALYSIS HAS BEEN SHOWING SOME
DECREASE IN CAPES AND INCREASE IN CAPPING ALOFT. HOWEVER...STILL
QUITE A BIT OF INSTABILITY AVAILABLE FROM SOUTHERN MISSOURI
NORTHEAST INTO EAST CENTRAL ILLINOIS. LATEST NAM AND HRRR SHOW
DEVELOPMENT OCCURRING IN THESE AREAS OVER THE NEXT COUPLE HOURS.
WILL MAINTAIN LIKELY POPS OVER A LARGE PART OF THE CWA THIS
EVENING...THEN LIMIT THEM TO 40-50 PERCENT AFTER MIDNIGHT ACROSS
THE EAST CENTRAL AND SOUTHEAST CWA. ANY LINGERING RAIN ACROSS THE
FAR SOUTHEAST WILL LIKELY BE ENDING BEFORE SUNRISE.
LITTLE CHANGE MADE TO THE REMAINDER OF THE FORECAST. BRIEF
COOL DOWN WILL BE NOTED EARLY THIS WEEK AS HIGH PRESSURE DRIFTS
EAST ACROSS THE AREA. A SLOW WARMING TREND WILL BRING TEMPERATURES
BACK TO NEAR 90 MUCH OF THE REMAINDER OF THE WEEK...WITH HOTTER
WEATHER KNOCKING ON THE DOOR AS WE REMAIN ON THE FRINGE OF THE
UPPER RIDGING ACROSS THE WESTERN HALF OF THE NATION. MAIN FEATURE
OF CONCERN IN THE LONG RANGE IS ON THURSDAY AND FRIDAY...WHEN A
PIECE OF ENERGY DROPS SOUTHEAST OUT OF THE CANADIAN PRAIRIES. GFS
AND ECMWF NOT TOO FAR APART WITH THE TRACK OF THIS SHORTWAVE OVER
THE GREAT LAKES...BUT THE GFS IS MORE AGGRESSIVE WITH BRINGING
RAIN CHANCES ALL THE WAY SOUTH ACROSS ILLINOIS. WILL KEEP SOME
SLIGHT CHANCES IN THE GRIDS THURSDAY AND THURSDAY NIGHT...BUT WILL
LEAN MORE TOWARD THE ECMWF WITH ITS ODDS OF DRY WEATHER.
GEELHART
&&
.AVIATION...
ISSUED 1233 PM CDT SAT AUG 4 2012
TS ADVANCING ON THE ILLINOIS RIVER VALLEY THIS AFTERNOON RESULTING
IN TS ADDED TO PIA TAF. MORE LIKELY CLOSER TO 1830Z...BUT TEMPO
GROUP IN. ALSO HAVE ADDED GUSTS FOR THE AFTERNOON MOMENTUM
TRANSFER THAT MAY BE SLIGHTLY DELAYED BY THE SLOW IN DIURNAL
HEATING WITH THE EXPANSIVE ALTOSTRATUS AND AC OUT THERE NOW. SO
FAR...CONVECTIVE DEVELOPMENT REMAINS QUESTIONABLE ELSEWHERE...AND
AM KEEPING THE VCSH IN THE BEST TIME FRAME. WILL UPDATE AS BECOMES
NECESSARY FOR TS. TOWARDS MORNING...CHANCE FOR BR AND REDUCED
VSBYS INTO MVFR/IFR CAT REMAIN FOR TERMINALS WITH RAIN. SO
FAR...PIA AND BMI ARE MOST LIKELY AT THIS POINT. AND HAVE PUT IN A
BRIEF TEMPO FOR THE EARLY MORNING/DAWN HOURS.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
434 PM EDT SAT AUG 4 2012
.SHORT TERM...(TONIGHT)
ISSUED AT 432 PM EDT SAT AUG 4 2012
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW A VIGOROUS LOOKING
SHORTWAVE TROF ACROSS THE ERN DAKOTAS/MN. AT THE SFC...ASSOCIATED
COLD FRONT IS SLICING THRU WRN LAKE SUPERIOR/WRN UPPER MI AND NW
WI. DESPITE VIGOROUS LOOK OF SHORTWAVE...CONVECTION HAS BEEN KEPT IN
CHECK BY ABUNDANT CLOUD COVER THAT HAS PERSISTED THRU THE DAY ACROSS
GOOD PORTIONS OF UPPER MI AND NRN WI. LATEST SPC MESOANALYSIS SHOWS
MLCAPE OF MOSTLY UNDER 500J/KG ACROSS THE FCST AREA. HIGHEST
VALUES...A LITTLE OVER 500J/KG...ARE OVER THE E WHERE THERE HAS BEEN
MORE SUNSHINE WITH SFC DWPTS AROUND 70F. IF MORE INSTABILITY HAD
DEVELOPED...A FAIRLY SIGNIFICANT SVR WEATHER OUTBREAK WOULD PROBABLY
BE GETTING UNDERWAY ACROSS THE FCST AREA AS DEEP LAYER SHEAR IS
STEADILY INCREASING TOWARD THE 40-50KT RANGE DUE TO MIDLEVEL SPEED
MAX APPROACHING THE AREA.
MAIN SHOW TONIGHT WILL BE S OF THE AREA WITH CONVECTIVELY ENHANCED
SHORTWAVE TRACKING TOWARD SRN WI/NRN IL/LWR MI. THE ONGOING
ASSOCIATED CLUSTER OF STRONG/SVR STORMS WILL PASS S OF THE AREA.
THAT SAID...OVER THE NEXT FEW HRS...SHRA/TSRA SHOULD TEND TO EXPAND
NE ACROSS ROUGHLY THE E HALF OF THE FCST AREA AS HEIGHT FALLS AND
RIGHT ENTRANCE OF UPPER JET STREAK WORK TO INCREASE UPWARD MOTION.
THERE IS STILL THE POTENTIAL OF ISOLD SVR STORMS...BUT WITH CLOUD
COVER NOW INCREASING EVEN OVER THE ERN FCST AREA TO PREVENT
INSTABILITY FROM BUILDING HIGHER...IT APPEARS RISK OF SVR STORMS IS
DIMINISHING. WILL KEEP SLIGHT RISK OF SVR WORDING IN HAZARDOUS WX
OUTLOOK FOR THE NEXT FEW HRS OR SO.
AFTER ANY SHRA/TSRA WITH COLD FRONT DEPART...ATTENTION TURNS TO VORT
MAX AND SECONDARY COLD FRONT THAT WILL SWING INTO THE AREA LATE
TONIGHT. THERE HAS BEEN FAIRLY SOLID COVERAGE OF SHRA AND EVEN SCT
TSRA ACROSS SE MANITOBA INTO ADJACENT NRN ONTARIO WITH TROF AXIS
THOUGH PCPN HAS TAKEN ON MORE OF A DIURNAL SCT COVERAGE THIS AFTN.
AS TROF AXIS/VORT MAX DROP INTO THE AREA...THERE SHOULD BE DECENT
SHRA COVERAGE LATE TONIGHT INTO SUN MORNING...ESPECIALLY SINCE CAA
DROPS 850MB TEMPS TO AROUND 6C BY 12Z SUN. WITH WATER TEMPS AROUND
20C ON LAKE SUPERIOR...THE OVERWATER INSTABILITY WILL BE MORE THAN
SUFFICIENT FOR LAKE ENHANCEMENT UNDER CYCLONIC FLOW WITH ARRIVAL OF
VORT MAX. THUS...EXPECT SCT/NMRS SHRA TO DEVELOP LATE TONIGHT OVER
THE NW HALF OF UPPER MI. AS ALWAYS...UPSLOPE NW WINDS WILL LEAD TO
MOST NMRS COVERAGE OVER THE HIGHER TERRAIN DOWNWIND OF THE LAKE.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 432 PM EDT SAT AUG 4 2012
GOOD AGREEMENT FM THE GFS/ECMWF/GEM-NHEM WITH OVERALL UPPER AIR
PATTERN THROUGH THIS WEEK. PATTERN STARTS OFF WITH DEEP TROUGH OVER
THE UPPER GREAT LAKES AND BROAD WEST-TO-EAST RIDGE ACROSS THE
SOUTHERN TIER OF THE CONUS. BY MIDWEEK...RIDGE BECOMES MORE
AMPLIFIED OVER INTERMOUNTAIN WEST INTO WESTERN CANADA WHILE
TROUGHING REMAINS IN PLACE OVER EASTERN CANADA AND THE GREAT LAKES
AND NORTHEAST CONUS.
WEATHER WILL STAY ON THE ACTIVE SIDE AS MULTIPLE SYSTEMS IMPACT THE
UPPER GREAT LAKES. FIRST WILL BE RIGHT AT BEGINNING OF LONG TERM ON
SUNDAY. ANOTHER WEAKER COLD FRONT COMES THROUGH AREA ON TUESDAY.
MUCH STRONGER LOW PRESSURE SYSTEM FCST TO PUSH ACROSS GREAT LAKES
LATER THURSDAY INTO FRIDAY. IT IS THIS SYSTEM THAT SHOWS THE MOST
POTENTIAL TO PRODUCE NOTEABLE PRECIPITATION AMOUNTS IN THE LONG TERM.
SINCE THE LARGE TROUGH IS CLOSE BY AND RIDING REMAINS WELL TO THE
WEST...EXPECT TEMPERATURES TO GENERALLY BE WITHIN A FEW DEGREES OF
NORMAL. ONLY WARM EXCEPTION WILL BE ON MONDAY AHEAD OF ANOTHER COLD
FRONT. SOME COOL PERIODS ARE EXPECTED AS WELL. COOLEST OF THE BUNCH
LIKELY WILL BE ON SUNDAY...BUT SIMILAR COOLER TEMPERATURES MAY OCCUR
AGAIN ON FRIDAY ON IN WAKE OF LOW PRESSURE SYSTEM MOVING THROUGH THE
GREAT LAKES.
A VERY CHAGEABLE WEATHER DAY IS IN STORE FOR SUNDAY. COLD FRONT
THROUGH UPR MICHIGAN BY DAYBREAK WHILE SFC LOW PUSHES ACROSS JAMES
BAY. COOL AND MOIST CYCLONIC FLOW SFC THROUGH H7 AFFECTS MOST CWA
THROUGH LATE MORNING THEN HEIGHTS RISE QUICKLY WHILE EDGE OF SFC
HIGH BUILDS IN MID-LATE AFTN. MOIST CYCLONIC FLOW AND THERMAL TROUGH
WITH H85 TEMPS AS LOW AS +5C IN ADDITION TO A SHARP SECONDARY WAVE
DROPPING THROUGH MEAN TROUGH SHOULD COMBINE TO BRING A PERIOD OF
SHOWERS TO PORTIONS OF CWA THROUGH THE MORNING. WARM LK SUPERIOR
TEMPS NEAR +20C ALSO ALLOW LAKE EFFECT PROCESSES TO ENHANCE PCPN
AS DELTA T/S ARE AROUND 14-15C/LAKE INDUCED CAPES UP TO 250 J/KG.
INCREASED POPS OVER UPSLOPE AREAS FAVORED BY NW BLYR WINDS. HIGHEST
POPS IN THE MORNING...THEN RAPIDLY DROPPING OFF IN THE AFTN AS AREA
QUICKLY RESIDES IN SUBSIDENCE REGION OF THE STRONG SHORTWAVE. SKIES
PROBABLY CLEAR QUICKLY IN THE AFTN DUE TO SUBSIDENCE AND DRY AIR.
TEMPS KIND OF TRICKY...BUT FOLLOWED TREND CLOSER TO GEM-REGIONAL
SHOWING TEMPS STUCK IN THE MID 50S-LOW 60S INTO EARLY AFTN...THEN
RISING TOWARD 70 DEGREES LATER IN THE DAY WITH INCREASING SUNSHINE.
GUSTY WINDS OTHER FACTOR ON SUNDAY AS DEEP MIXING EXPECTED THROUGH
EARLY AFTN BEFORE H85 WARM ADVECTION INCREASES STABILITY. MIXED
LAYER WINDS THROUGH 16Z 35-40KT AND EXPECT GOOD PORTION OF THESE TO
MIX TO SFC. STRONGEST WINDS NEAR EXPOSED LK SUPERIOR SHORE OF CNTRL
AND EAST. EXPECT WINDS TO DIMINISH BY LATE DAY.
HIGH PRESSURE AXIS REMAINS JUST SOUTH OF AREA SUNDAY NIGHT BUT WINDS
BECOME LIGHT ENOUGH/PWAT LOW ENOUGH TO SEE SOME RADIATIONAL COOLING
TAKE PLACE. LOWEST MINS SEEM LIKELY IN THE INTERIOR CNTRL AND EAST
WHERE COLD SPOTS MAY DROP INTO LOWER 40S.
MUCH DIFFERENT DAY ON MONDAY COMPARED TO COOLER/WINDY DAY ON SUNDAY.
HIGH PRESSURE SLIDES EAST AND A WEAK COLD FRONT IS FCST TO DROP INTO
UPR LAKES MONDAY NIGHT. NOT A LOT OF CLOUD COVER AHEAD OF FRONT
THOUGH OTHER THAN ON THE KEWEENAW IN THE LATER AFTN. WITH H85 TEMPS
15C-16C EXPECT HIGHS TO REACH WELL INTO THE 80S AWAY FM LK MICHIGAN
SHORE. AS UPR JET SLIDES ACROSS ONTARIO MONDAY NIGHT AND MID-LEVEL
FGEN INCREASES OVR LK SUPERIOR...EXPECT BAND OF SHRA/TSRA TO DEVELOP
ALONG SFC FRONT. FRONT SLIDES THROUGH CWA ON MONDAY NIGHT...WITH
BETTER CHANCES OF SHRA/TSRA TIED INTO THE MID-LEVEL FORCING.
SOUNDINGS SHOW DRY AIR LINGERING BLO H85-H7 DUE TO LIMITED MOISTURE
ADVECTION FM THE GULF INTO THIS SYSTEM. SO...COVERAGE OF PRECIP WILL
BE SPOTTY WITH THE FRONT. HIGH PRESSURE BUILDS BACK IN FOR TUESDAY
WITH TEMPS IN THE 70S NORTH AND NEARING 80 DEGREES OVR THE SOUTH AND
NEAR LK MICHIGAN.
EXTENDED...MAIN CHANCES FOR SHRA/TSRA COME IN LATER WEDNESDAY NIGHT
INTO THURSDAY AS ANOTHER UPPER LOW AND SFC LOW MOVE ACROSS THE UPR
LAKES. CYCLONIC FLOW LINGERING IN THE WAKE OF THE SFC LOW COULD
KEEP SOME SHRA GOING OVR THE AREA INTO FRIDAY...KIND OF SIMILAR TO
WHAT IS EXPECTED ON SUNDAY. WITH EXPECTED CLOUDS/PCPN...TRIMMED
TEMPS THURSDAY AND FRIDAY CLOSER TO LK SUPERIOR WHERE ONSHORE
NORTHEAST FLOW SHOULD RESULT IN COOLER CONDITIONS. INCREASED WINDS
OVR LK SUPERIOR SOME COMPARED TO GUIDANCE CONSENSUS BUT MAY NEED TO
INCREASE FURTHER WITH LATER FCSTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 139 PM EDT SAT AUG 4 2012
COLD FRONT MOVING ACROSS THE AREA THIS AFTN/EVENING AND FOLLOWED BY
SECONDARY COLD FRONT LATE TONIGHT/SUN MORNING WILL BE THE FEATURES OF
INTEREST. CLOUD COVER PER SATELLITE IMAGERY SHOULD SUFFICIENTLY HOLD
INSTABILITY DOWN TO KEEP TSRA POTENTIAL MINIMAL WITH FIRST COLD FROPA
AT KIWD/KCMX. HAVE ONLY INCLUDED VCSH MENTION THRU THE MID TO LATE
AFTN HRS AT THOSE SITES. KSAW IS MORE LIKELY TO SEE TSRA LATER THIS
AFTN DUE TO BETTER POTENTIAL FOR INSTABILITY TO BUILD PRIOR TO FROPA.
IF TSRA OCCUR...IFR/LIFR CONDITIONS POSSIBLE ALONG WITH GUSTY WINDS.
A PERIOD OF VFR CONDITIONS EXPECTED AT ALL SITES AFTER FIRST FROPA.
SECONDARY COLD FROPA LATER TONIGHT/SUN MORNING WILL BRING GUSTY NW
WINDS TO ROUGHLY 25-30KT...STRONGEST AT KCMX DUE TO FAVORABLE WIND
DIRECTION AND INCREASING OVERWATER INSTABILITY UNDER INCOMING BRIEF
SHOT OF COOL AIR. WITH OVERWATER INSTABILITY BECOMING SUFFICIENT FOR
LAKE ENHANCEMENT...CYCLONIC FLOW AND PASSING SHORTWAVE SHOULD RESULT
IN A SEVERAL HR PERIOD OF IFR CONDITIONS IN SHRA/BR AT ALL SITES
LATER TONIGHT/SUN MORNING. IMPROVEMENT TO VFR EXPECTED AT KIWD/KCMX
LATE MORNING/EARLY AFTN AND AT KSAW JUST AFTER THIS FCST PERIOD AS
STRONG SUBSIDENCE/DRYING ARRIVE UNDER PROGRESSIVE FLOW PATTERN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 432 PM EDT SAT AUG 4 2012
COLD FRONT PASSES ACROSS LK SUPERIOR THIS EVENING. PERIOD OF STRONG
WINDS AND HIGH WAVES /LIKELY OVR 10 FEET/ EXPECTED LATE TONIGHT
THROUGH MUCH OF SUNDAY AFTERNOON. EXPECT 25-30 KT WINDS FM THE
NORTHWEST DURING ON SUNDAY WITH FREQUENT GALE GUSTS 35-40 KTS. A
GALE WATCH HAS BEEN POSTED FOR THE EAST HALF OF LK SUPERIOR MOST
OF SUNDAY. WINDS DIMINISH SUNDAY NIGHT...BUT THEN INCREASE FM THE
SOUTHWEST ON MONDAY AHEAD OF A COLD FRONT THAT SLIDES THROUGH ON
MONDAY NIGHT. IN WAKE OF THE FRONT...EXPECT WINDS 20 KTS OR LESS
TUESDAY INTO WEDNESDAY AS HIGH PRESSURE MOVES ACROSS THE REGION.
WINDS MAY END UP STRONGER THAN FCST FOR LATE THIS WEEK AS DETAILS
ARE SORTED OUT REGARDING ANOTHER LOW PRESSURE SYSTEM MOVING THROUGH
THE UPPER GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY EVENING FOR LSZ251-
267.
GALE WATCH FROM SUNDAY MORNING THROUGH SUNDAY AFTERNOON FOR
LSZ249-250-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
154 PM CDT SAT AUG 4 2012
.UPDATE...
18Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
THE POWERFUL UPPER LEVEL SYSTEM WHICH SPARKED THE SQUALL LINE THAT
MARCHED ACROSS THE REGION OVERNIGHT WILL BE RESPONSIBLE FOR A
FEW MORE STORMS TODAY. IN THE WAKE OF THIS SYSTEM IS MUCH COOLER
AND DRIER AIR...WHICH WILL SETTLE IN ACROSS THE UPPER MIDWEST FOR
A MAJORITY OF THIS COMING WEEK.
TODAY...EARLY MORNING WATER VAPOR IMAGERY WITH 500MB HEIGHTS AND
WINDS SHOWED A BEAUTIFUL UPPER LEVEL WAVE SLIDING DOWN ACROSS THE
DAKOTAS. THIS WAVE HAD ITS ORIGINS FROM ALBERTA CANADA...BUT THE
DIFFERENCE BETWEEN THIS SYSTEM AND A TYPICAL ALBERTA CLIPPER IS THAT
THIS STORM WAS ABLE TO TAP INTO THE MONSOONAL MOISTURE ASSOCIATED
WITH THE SUBTROPICAL JET OFF THE SOUTHWEST US. THE COMBINATION OF
THE STRONG DYNAMICAL FORCING WITH THE CANADIAN WAVE...AND THE
FAVORABLE THERMODYNAMICS OF THE SUBTROPICAL AIRMASS LED TO SEVERAL
AREAS OF SHOWERS AND THUNDERSTORMS FROM NORTHERN WISCONSIN THROUGH
CENTRAL NEBRASKA. THE COMBINATION OF BOTH THE PHASING OF THE
SUBTROPICAL AND NORTHERN STREAM JETS...ALONG WITH THE CONTINUED
BANGING ON THE TROPOSPHERIC DRUM BY REPEATED ROUNDS OF CONVECTION
WILL CAUSE A +110KT JET STREAK TO FORM OVER NORTHERN MINNESOTA BY
LATER THIS AFTERNOON. THE AGEOSTROPHIC DIVERGENCE IN THE RIGHT
ENTRANCE REGION OF THIS JET...THE DOWNSTREAM POSITIVE VORTICITY
ADVECTION ASSOCIATED WITH THE UPPER LEVEL WAVE...AND THE LOW/MID
LEVEL FRONTOGENESIS WITH THE APPROACHING COLD FRONT WILL SUPPLY
PLENTY OF FORCING FOR CONTINUED PRECIP THROUGH THIS MORNING AND
EARLY AFTERNOON ACROSS THE SOUTHERN AND EASTERN CWA. FORECAST
SOUNDINGS SHOW DEEP LAYER SPEED SHEAR FAVORABLE FOR ORGANIZED
CONVECTION...BUT THE COLD AIR ADVECTION SHOULD LIMIT THE
INSTABILITY AND CONFINE SEVERE POTENTIAL TO CENTRAL AND EASTERN
WISCONSIN...DESPITE THE STRONG DYNAMICS. NONE THE LESS...COULD SEE
A FEW STRONGER STORMS EARLIER TODAY ACROSS FAR SOUTHERN AND EASTERN
MINNESOTA...AND WESTERN WISCONSIN. IN THE WAKE OF THIS
FRONT...NORTHWEST WINDS WILL INCREASE ACROSS THE ALEXANDRIA/ST
CLOUD AREA WITH AFTERNOON MIXING AND COLD AIR ADVECTION.
TONIGHT THROUGH FRIDAY...AN UPPER LEVEL RIDGE WILL SET UP ACROSS
THE 4-CORNERS REGION AND NORTHWEST FLOW WILL PREVAIL OVER THE
UPPER MIDWEST. FOR SUNDAY...COOLER AIR ON THE BACK SIDE OF THE
AFOREMENTIONED UPPER LEVEL WAVE WILL WRAP IN AND LIKELY BRING AN
END TO THE 80 DEGREE STREAK AT MINNEAPOLIS...WITH HIGHS ONLY
EXPECTED TO BE IN THE 70S REGION WIDE. A WEAK WAVE EMBEDDED IN
THIS FLOW REGIME WILL TRACK ACROSS THE REGION ON MONDAY...AND
COULD SEE SOME PRECIP DEVELOP ACROSS THE SOUTH LATE MONDAY ALONG
AN AREA OF H850 THETA_E ADVECTION. A SIMILAR FEATURE WILL TRACK
ACROSS THE REGION ON WEDNESDAY...WITH A MORE POTENT WAVE DROPPING
DOWN FROM CANADA OVER LAKE SUPERIOR ON THURSDAY. HAVE SOME 20-30
POPS IN THE GRIDS TO ACCOUNT FOR THESE TWO FEATURES. TEMPERATURES
WILL BE NEAR THE SEASONAL AVERAGE FOR LATE SUMMER.
&&
.AVIATION.../18Z TAF ISSUANCE/
PRIMARY FRONT HAS JUST CLEARED EAU...WITH A SECONDARY COLD FRONT
ASSOCIATED WITH THE UPPER LOW SLIDING SE ACROSS NODAK AND NW MN.
BAND OF MVFR CIGS IS WORKING ACROSS WRN WI BEHIND THE FRONT AND
WILL LINGER IN EAU THROUGH NO LATER THAN 20Z. COLD AIR ALOFT
ASSOCIATED WITH TROUGH LEADING TO THE DEVELOPMENT OF SCT SHOWERS
NW OF THE MPX AREA...THOUGH AS THE UPPER WAVE MOVES IN...EXPECT SCT
SHOWERS TO REACH DOWN INTO THE AXN/STC AREAS. FEEL HRRR IS A BIT
TOO AGGRESSIVE IN BRINGING SCT SHOWERS CLEAR DOWN TO THE IA BORDER.
TONIGHT...AS SECONDARY COLD FRONT SWINGS THROUGH...WINDS WILL TURN
NW AND WILL LIKELY COME WITH A BOUT OF MVFR CIGS...ESPECIALLY
ACROSS CENTRAL MN...THOUGH MSP/RNH/EAU MAY SEE SOME MVFR
CONDITIONS AS THE COLD AIR TROUGH MOVES THROUGH. AFTER
THAT...WEATHER LOOKS QUITE TRANQUIL FOR SUNDAY.
KMSP...ONLY A COUPLE OF MINOR THINGS TO WATCH THIS PERIOD.
FIRST...WITH SECONDARY FRONT TO DROP THROUGH THIS EVENING...MAY
SEE ENOUGH BACKING IN WINDS TO RESULT IN AN OCCASIONAL 250/260
DIRECTIONAL THROUGH 00Z BEFORE A MORE UNIFORM NW WINDS SETS UP
THIS EVENING. THERE WILL ALSO BE THE VERY SMALL THREAT OF AN
ISOLATED SHOWER AT THE AIRPORT THIS AFTERNOON...BUT BEST CHANCES
SHOULD BE CLOSER TO THE COLD AIR ALOFT NW OF THE FIELD.
FINALLY...PER THE RAP/NAM...EXPECT A BAND OF MVFR CIGS TO SWING
ACROSS NRN/CENTRAL MN THIS EVENING...WHICH MAY BRING THE THREAT
FOR AN MVFR CIG BETWEEN 5 AND 10Z BEFORE SKIES GO SKC.
/OUTLOOK/
.MONDAY...VFR. WINDS SW AT 10KT.
.TUESDAY...VFR. WINDS NW AT 5KT.
.WEDNESDAY...VFR. WINDS SOUTH 5 KNOTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JRB/MPG
AREA FORECAST DISCUSSION
NWS DULUTH MN
1236 PM CDT SAT AUG 4 2012
.AVIATION...18Z TAFS
MVFR CIGS WILL LINGER ACROSS FAR E MINNESOTA AND NW WISCONSIN
THROUGH EARLY THIS AFTERNOON...INCLUDING AT KDLH/KHYR...DUE TO THE
LOW STRATUS ASSOCIATED WITH A COLD FRONT THAT MOVED THROUGH THE
REGION EARLIER THIS MORNING. THE VFR CONDITIONS THAT HAVE
DEVELOPED ACROSS THE REST OF THE NE MINNESOTA SHOULD SPREAD INTO
NW WISCONSIN THIS AFTERNOON. VFR CONDITIONS SHOULD PREDOMINATE FOR
THE MID TO LATE AFTERNOON...BUT ANOTHER COLD FRONT BEGINNING TO
MOVE INTO FAR NW MINNESOTA WILL BEGIN TO MOVE INTO NE MINNESOTA
MID TO LATE AFTERNOON. THIS SECOND COLD FRONT WILL PROBABLY RESULT
IN SCATTERED RAIN SHOWERS...AND MAYBE SOME WEAK THUNDERSHOWERS. AT
THIS POINT...INCLUDED VCSH AND TEMPO OF -RA FOR
KINL/KHIB/KBRD...BUT MAY NEED TO INCLUDE VCTS OR TEMPO OF -TSRA
ONCE ANY STORMS MOVE INTO OR DEVELOP OVER NE MINNESOTA.
ALSO...THE SHOWERS AND STORMS MAY RESULT IN BRIEF PERIODS OF MVFR
CIGS AND VSBYS. WESTERLY WINDS OF 10 TO 15 KNOTS WITH GUSTS UP TO
25 KNOTS ARE GENERALLY EXPECTED THROUGH EARLY THIS EVENING AT ALL
TERMINALS...WITH WINDS RELAXING AND BECOMING NORTHWESTERLY
TONIGHT. MVFR CIGS WILL PROBABLY REAPPEAR THIS THIS EVENING IN THE
WAKE OF THE COLD FRONT...BUT CLEAR SKIES SHOULD DEVELOP LATE
TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 933 AM CDT SAT AUG 4 2012/
UPDATE...
SPREAD SCATTERED SHOWERS FURTHER WEST AND DE-EMPHASIZED THUNDER
ACROSS THE AREA THIS MORNING. DECREASED WINDS A LITTLE THIS
MORNING.
SHORT TERM...
THE ACTUAL FRONT IS MOVING THROUGH THE DULUTH AREA MID-MORNING
THIS MORNING. IT IS BECOMING A STRONG FRONT...WITH THE UPPER FLOW
AND THERMAL WIND LINING UP MORE AND MORE PARALLEL TO IT. THIS
SLOWS DOWN ITS FORWARD PROGRESS AND INCREASES MOISTURE AND CAUSES
PRECIPITATION TO FILL IN BEHIND IT. BRIEF SURFACE RIDGING BEHIND
THE FRONT IS FOLLOWED BY THE TROUGH THAT REFLECTS FALLING HEIGHTS
ALOFT. WE LEFT IN SHOWERS AND DID NOT DE-EMPHASIZE THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING...THUNDERSTORMS WILL BE SHALLOW...
BRIEF...AND SPOTTY IN DISTRIBUTION. SOUTHWEST WINDS WILL COME UP A
LITTLE LATER...AS THE SECOND TROUGH APPROACHES...AND SLOWLY VEER.
PREV DISCUSSION... /ISSUED 631 AM CDT SAT AUG 4 2012/
AVIATION...12Z TAFS.
FIRST FRONTAL BOUNDARY IS MOVING THROUGH FA ATTM. A FEW SHOWERS
WILL OCCUR IN THE VCNTY OF THE FRONT. LATER TODAY...THE SECOND
FRONT WILL BEGIN TO CROSS THE AREA WITH ADDITIONAL SHOWERS AND
POSSIBLY A THUNDERSTORM. A MIX OF MVFR/IFR CIGS WITH THE FIRST
FRONT UNTIL AROUND 15Z THEN AN IMPROVEMENT TO VFR. WITH THE SECOND
FRONT...CIGS WILL DROP BACK INTO THE MVFR WITH VCSH AT MOST SITES
FROM 18Z TO 00Z. CIGS IMPROVE TO VFR WITH THE DEPARTURE OF THE
FRONT AND DRIER AIR ARRIVING WITH HIGH PRESSURE AFTER 06Z.
PREV DISCUSSION... /ISSUED 323 AM CDT SAT AUG 4 2012/
SHORT TERM...THROUGH SUNDAY.
CONVECTIVE SYSTEM WILL EXIT THE CWA OVER THE CWA IN THE NEXT 2 TO 3
HOURS. GUSTY WINDS...30-45 MPH AND SOME HAIL WILL BE POSSIBLE IN
SPOTS WITH THIS LINE. THE FRONTAL BOUNDARY WAS STILL WEST OF THE
CWA...AND SHOULD REACH OUR EASTERN MN ZONES BY 12Z...AND EXIT THE
EASTERN CWA BY MID AFTERNOON. THE 925MB BOUNDARY WILL TAKE A BIT
LONGER TO EXIT...AND IS FORECAST TO BE THROUGH THE ARROWHEAD AND
OUR EASTERN WI COUNTIES AT 18Z. ADDITIONAL SHOWERS AND STORMS WERE
FIRING IN SOUTHERN MINNESOTA/SOUTHEAST SOUTH DAKOTA ALONG AND
AHEAD OF THE FRONT. UPPER WAVE WAS ALSO MOVING THROUGH THE
DAKOTAS...WHICH WILL AID IN ADDITIONAL LIFT. POPS ARE A BIT TRICKY
THIS MORNING. WE HAVE THEM HIGHEST IN THE EAST...AND WENT DRY IN
THE FAR WEST. WE`LL KEEP AN EYE ON THE ACTIVITY IN SOUTH DAKOTA
AND MAY HAVE TO INCLUDE A POP IN PORTIONS OF THE WEST-SOUTHWEST
THIS MORNING IF THAT ACTIVITY PERSISTS OR EXPANDS. HIGH RES WRF
AND HRRR SHOW THIS FALLING APART AS IT MOVES EAST-NORTHEAST.
THIS AFTERNOON SHOULD SEE THE HIGHER CHANCES FOR SHOWERS/STORMS IN
THE NORTH CLOSER TO THE UPPER LOW AND COLDER TEMPS ALOFT. WE HAVE A
CHANCE FOR SHOWERS AND STORMS ACROSS MOST ZONES...RANGING FROM
SLIGHT TO LIKELY. SHOWERS WILL DIMINISH THROUGH THE EVENING...BUT WE
KEPT A MENTION OF SHOWERS ALL NIGHT IN THE ARROWHEAD IN AREA OF
HIGHEST MOISTURE/AND NEAREST THE UPPER LOW.
IT SHOULD BE DRY SUNDAY WITH HIGH PRESSURE BUILDING IN.
TEMPERATURES TODAY AND SUNDAY FOR MOST AREAS WILL BE IN THE
SEVENTIES. EXPECT LOWS TONIGHT TO DROP INTO THE UPPER FORTIES IN THE
TRADITIONALLY COLDER SPOTS...WITH 50 TO 55 ELSEWHERE.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY.
SFC RIDGING COVERS THE FA SUNDAY NIGHT. ON MONDAY...A WEAK COLD
FRONT WILL CROSS INTO THE FA FROM CANADA. HAVE SMALL POPS IN THE
AFTERNOON IN RESPONSE TO SHORT WAVE ENERGY INTERACTING WITH THE
FRONT TO POSSIBLY GENERATE THUNDERSTORMS. THE FRONT WILL CROSS THE
REST OF THE FA MONDAY NIGHT. MOISTURE IS LIMITED AND HAVE SMALL
POPS IN NW WI FOR ANY STORMS. RIDGING RETURNS FOR TUESDAY AND
TUESDAY NIGHT. BY WEDNESDAY...A WARM FRONT IS PROGGED TO LIFT NWD
INTO THE FA FROM THE SW. MEANWHILE...AN UPPER LEVEL SHORT WAVE
DROPS OUT OF CANADA. THESE FEATURES WARRANT A SMALL POP. MOISTURE
IS LIMITED AHEAD OF THE FRONT AND THAT IS WHERE THESE STORMS ARE
EXPECTED TO DEVELOP AND HAVE SMALL POPS. A STRONG CUT OFF LOW WILL
MOVE ACROSS SOUTH CENTRAL CANADA WEDNESDAY NIGHT. THIS PUSHES A
SFC LOW AND STRONG COLD FRONT THROUGH THE FA. GFS AND ECMWF
DISAGREE ON TIMING AND OVERALL COVERAGE SO CHANCE POPS USED. THE
UPPER LOW CONTINUES TO MOVE SEWD AND GENERATE ADDITIONAL PCPN AND
MAINTAINED POPS IN THE PATH OF THE LOW. LINGERED POPS THURSDAY
NIGHT IN THE FAR EASTERN WI FA FOR AN LINGERING STORMS AS THE
UPPER LOW DEPARTS. RIDGING RETURNS FOR FRIDAY.
AVIATION...06Z ISSUANCE
WIDESPREAD SHOWERS AND THUNDERSTORMS CURRENTLY LOCATED OVER THE
REGION WILL GRADUALLY EXIT TO THE EAST THROUGH 12Z. EXPECT
VARIABLE WIND GUSTS TO 30 KT AND MVFR/IFR CONDITIONS IN ANY OF
THESE STORMS. WEST TO NORTHWEST SURFACE WINDS AND VFR CONDITIONS
WILL PREVAIL THROUGH MID-DAY SATURDAY...WITH SCATTERED RAIN
SHOWERS AND CEILINGS AROUND 4-6 KFT MAINLY AFTER 20Z.
&&
.POINT TEMPS/POPS...
DLH 53 76 55 83 / 20 10 0 10
INL 45 77 54 80 / 40 10 0 20
BRD 53 77 53 85 / 10 10 0 10
HYR 54 76 50 84 / 10 10 0 10
ASX 55 77 54 82 / 20 10 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...NONE.
&&
$$
SHORT TERM...EOM
LONG TERM....GROCHOCINSKI
AVIATION...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
554 PM CDT Sat Aug 4 2012
...UPDATED AVIATION DISCUSSION...
.DISCUSSION...
Well, looks like we have to wait for rain again. At least in many
areas this seems to be the appropriate theme for today, as yet
another shortwave/MCV race ahead of the surface front this morning
effectively shoving stabilizing much of northern Missouri and
allowing a weak surface trough to sneak southeast into Missouri and
Kansas. Currently the primary surface trough stretches from Ottumwa,
IA southwest through Kansas City and further south towards Wichita,
KS. A continued stream of mid-level strato-cu has suppressed the
warm surface temperatures in the extreme southern CWA with 88D radar
composites indicating northward extent of surface warm front is just
south of the Pleasant Hill office.
For tonight, highest convective potential remains along our southern
and southeastern tier of counties and again in areas near Kirksville
as mid-level shortwave currently moving through central Kansas
reaches the area after 4pm. HRRR and RAP suggest widely scattered
convection forming along the differential heating axis in the
southern CWA after 4pm with this convection slowly sinking southeast
this evening. Instability and shear plots indicate multi-cell
clusters would be the preferred storm type with downburst winds the
main threat. Elsewhere in areas further north, scattered high based
showers or sprinkles may the result of the weak shortwave and 850
trough passing through the area this evening. Dew points will remain
elevated through the evening as true front is just arriving into the
northwest corner of the CWA.
Will linger chc pops across the southern CWA through the overnight
hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied
with the right entrance region of the upr jet may be enough forcing
for west to east ling of elevated convection through early Sunday
morning in west central into central MO.
Sunday-Monday: Surface high pressure will drift southeast into the
region by Sunday morning. North to northeast winds will prevail
through the daytime hours with temperatures struggling to reach the
middle 80s in northern MO and barely hitting 90 towards east central
Kansas and central MO. This surface ridge will quickly slide into
the Ohio river valley by Monday allowing winds to take a more
southerly track. The resultant bump in low-level temperatures will
push daytime highs in the lower to middle 90s.
Tuesday-Friday: The overall longwave pattern will feature a building
ridge over the western CONUS and broad northwesterly flow over the
central and eastern US. GFS/EC/GEM indicate a weak disturbance in
the NW flow pattern moving through as we reach Tuesday night into
Wednesday. Always hard to time these shortwaves and their impact
especially considering the lack of boundary layer moisture. However
one could justify at least a slight chance for precip. Temperatures
will run near or slightly above normal through the end of the week.
31
&&
.AVIATION...
VFR conditions expected for all terminals through the forecast
period. Widely scattered showers continue to move across the area
this evening but should push east of the TAF sites in a few hours.
Otherwise, light north winds are expected to persist through
tomorrow.
Deroche
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053-
054.
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
323 PM CDT Sat Aug 4 2012
.DISCUSSION...
Well, looks like we have to wait for rain again. At least in many
areas this seems to be the appropriate theme for today, as yet
another shortwave/MCV race ahead of the surface front this morning
effectively shoving stabilizing much of northern Missouri and
allowing a weak surface trough to sneak southeast into Missouri and
Kansas. Currently the primary surface trough stretches from Ottumwa,
IA southwest through Kansas City and further south towards Wichita,
KS. A continued stream of mid-level strato-cu has suppressed the
warm surface temperatures in the extreme southern CWA with 88D radar
composites indicating northward extent of surface warm front is just
south of the Pleasant Hill office.
For tonight, highest convective potential remains along our southern
and southeastern tier of counties and again in areas near Kirksville
as mid-level shortwave currently moving through central Kansas
reaches the area after 4pm. HRRR and RAP suggest widely scattered
convection forming along the differential heating axis in the
southern CWA after 4pm with this convection slowly sinking southeast
this evening. Instability and shear plots indicate multi-cell
clusters would be the preferred storm type with downburst winds the
main threat. Elsewhere in areas further north, scattered high based
showers or sprinkles may the result of the weak shortwave and 850
trough passing through the area this evening. Dew points will remain
elevated through the evening as true front is just arriving into the
northwest corner of the CWA.
Will linger chc pops across the southern CWA through the overnight
hours, as 850 mb front stalls. Weak 850:700 mb frontogenesis tied
with the right entrance region of the upr jet may be enough forcing
for west to east ling of elevated convection through early Sunday
morning in west central into central MO.
Sunday-Monday: Surface high pressure will drift southeast into the
region by Sunday morning. North to northeast winds will prevail
through the daytime hours with temperatures struggling to reach the
middle 80s in northern MO and barely hitting 90 towards east central
Kansas and central MO. This surface ridge will quickly slide into
the Ohio river valley by Monday allowing winds to take a more
southerly track. The resultant bump in low-level temperatures will
push daytime highs in the lower to middle 90s.
Tuesday-Friday: The overall longwave pattern will feature a building
ridge over the western CONUS and broad northwesterly flow over the
central and eastern US. GFS/EC/GEM indicate a weak disturbance in
the NW flow pattern moving through as we reach Tuesday night into
Wednesday. Always hard to time these shortwaves and their impact
especially considering the lack of boundary layer moisture. However
one could justify at least a slight chance for precip. Temperatures
will run near or slightly above normal through the end of the week.
31
&&
.AVIATION...
For the 18Z TAFs...Quick progression of a cold front across Missouri
has resulted in winds at the terminals turning to the northeast in
the wake of some scattered convection this morning. Further
thunderstorm development might occur across northern and central
Missouri this afternoon, but at this time thoughts are this activity
will be east of all the terminals. As a result, only issue to watch
for looks to be the slightly gusty north winds this afternoon in the
post-frontal environment. Winds should stay from the north
overnight, with VFR skies prevailing.
Cutter
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
MO...HEAT ADVISORY until 8 PM CDT this evening FOR MOZ040-043>046-053-
054.
KS...HEAT ADVISORY until 8 PM CDT this evening FOR KSZ057-060.
&&
$$
WFO EAX
AREA FORECAST DISCUSSION...CORRECTED
NWS HASTINGS NE
406 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE
NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING
ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED
BY JUST HOW COOL WILL IT GET TONIGHT.
19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER
MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE
MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED
WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA
TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST
OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE
STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE
SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE
AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF
ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING
TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE
CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG
MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE
500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE
RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP
WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO
BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW
80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE
SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN
THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN
THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF
THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL
HANGING ON IN THE SOUTHEAST.
STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A
LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS
LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE
BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST
COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE
LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS
OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST
OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED
SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS
LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL
CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB.
GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE
EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS
THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED
SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST
OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS
THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION
OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE
RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS
WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO
THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY
LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN
SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY
OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING
SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL
NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z
MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS
FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN
COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL
AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE
VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S.
FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE
OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING.
FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED
OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS
FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL
REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE
AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS
NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT
TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND
VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE
AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE
AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE
AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL
GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY
REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT
REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY
81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST
MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY
DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL
WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO
EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL
THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND
ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS
YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS
ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM
PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND
LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD
DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A
FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF
FIRE WEATHER CRITERIA.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD
OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY
EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER
LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE
SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST.
DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER
TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE
DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST
DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING
S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY
SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ
DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS
LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE
CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL
FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY
DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD
COVER.
INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A
MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY
DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE
AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY
LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA.
DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE
N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER
SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY
WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER
TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR
MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS
SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE
LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE
EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE
TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO
TREND UP WINDS/TREND DOWN DPS.
KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY
ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE
SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB
AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF
THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT.
WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT
BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND
FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE
LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS
THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY
NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS
EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE
NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS
IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE
POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR
TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS
THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT
OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO
WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT
EXPECTING SEVERE WEATHER AT THIS POINT.
INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER
LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN
THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN
PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER
CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM
PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE
REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL
ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS
SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF
THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE
RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE
POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER
TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM
ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT.
&&
.PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST
THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA
THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL
3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM
OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING
SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER
MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN
THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS
WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW
HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS
COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD
AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH
TIME.
&&
.CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST
DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON
FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY
HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP
SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST
78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE
THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES
WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT
TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD
ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED
78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR
BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3
DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES
ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994.
ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE
THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND
ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH SUNDAY AFTERNOON. PRIMARY ISSUES THROUGH THE
NEXT 24 HOURS INCLUDE TIMING THE THE LAST FEW HOURS OF LINGERING
ISOLATED/SCATTERED LIGHT PRECIP THROUGH LATE AFTERNOON...FOLLOWED
BY JUST HOW COOL WILL IT GET TONIGHT.
19Z OBJECTIVE SURFACE ANALYSIS CENTERS A 1022MB HIGH OVER
MT/WY...WITH THE RIDGE AXIS EXTENDING DOWN INTO WESTERN NEB. THE
MUCH-AWAITED STRONGEST COLD FRONT WE HAVE SEEN AWHILE HAS PUSHED
WELL OFF TO THE SOUTH AND EAST...NOW ALIGNED ALONG FROM EASTERN IA
TO THE TX PANHANDLE. ALTHOUGH MID AFTERNOON WINDS CONTINUE TO GUST
OVER 20 MPH IN MANY AREAS FROM THE NORTH/NORTHWEST...THEY ARE
STARTING A GRADUAL DECLINE AS THE STRONGEST PRESSURE RISES SLIDE
SOUTHEAST WITH THE FRONT. RADAR IMAGERY AND VISIBLE SATELLITE
AROUND 1930Z GENERALLY CONFIRM THE EARLIER EXPECTATIONS OF
ISOLATED/SCATTERED MAINLY LIGHT HIGH BASED RAIN SHOWERS STARTING
TO INCREASE IN COVERAGE A BIT ACROSS THE SOUTHERN 1/2 OF THE
CWA...ALTHOUGH NO LIGHTNING STRIKES HAVE YET BEEN DETECTED. WATER
VAPOR IMAGERY AND SHORT TERM MODEL DATA REVEAL A SEASONABLY STRONG
MID LEVEL VORT MAX TRACKING EAST NEAR FAR NORTHERN MN...WITH THE
500MB SHORTWAVE AXIS TRAILING SOUTHWEST TO THE LOCAL AREA...WHILE
RIDGING DOMINATES THE SOUTH CENTRAL AND WEST CENTRAL CONUS. TEMP
WISE THIS AFTERNOON...STILL ANTICIPATING SOME LATE DAY SUNSHINE TO
BOOST AT LEAST MUCH OF THE NORTHWEST 1/2 OF THE CWA INTO THE LOW
80S...BUT THE JURY IS STILL OUT ON WHETHER PARTS OF THE
SOUTHEAST...MAYBE EVEN HASTINGS...WILL EVEN MAKE IT TO 80 GIVEN
THE EXTENSIVE MID CLOUDS LINGERING LONGER. SEASONABLY DRY AIR IN
THE FORM OF MID 40S-LOW 50S DEWPOINTS CONTINUE TO INVADE MUCH OF
THE CWA FROM THE NORTHWEST...ALTHOUGH SOME UPPER 50S ARE STILL
HANGING ON IN THE SOUTHEAST.
STARTING OFF WITH THE NEXT FEW HOURS THROUGH 00Z...JUST MADE A
LAST MINUTE DECISION TO PULL THUNDER MENTION ALTOGETHER...AS
LATEST HOURLY MESOANALYSIS AND RAP INSTABILITY PROGS INDICATE
BARELY EVEN 100 J/KG MUCAPE REMAINING IN THE FAR SOUTHEAST
COUNTIES...AND ONGOING LIGHT SHOWERS HAVE NOT EXHIBITED DETECTABLE
LIGHTNING AT ALL OVER THE PAST FEW HOURS. THESE LINGERING SHOWERS
OVER THE NEXT FEW HOURS WILL MAINLY AFFECT LIMITED AREAS SOUTHEAST
OF A LINE FROM HEBRON-STOCKTON...AND WILL CARRY ISOLATED/SCATTERED
SHOWER WORDING FOR JUST A FEW MORE HOURS TO COVER THEM. THIS
LINGERING PRECIP IS CLEARLY TIED TO A QUICKLY DEPARTING MID LEVEL
CONVERGENCE/FRONTOGENETIC ZONE EVIDENT AT 700MB.
GETTING TO THE OFFICIAL NIGHT PERIOD 00Z-12Z...BY THE START OF THE
EVENING ANTICIPATE CONSIDERABLE CLEAR SKIES NEARLY CWA-WIDE...AS
THE BACK EDGE OF THE PRIMARY MID DECK AND ASSOCIATED
SHOWERS/POSSIBLE WEAK STORMS SHOULD BE JUST OFF TO THE SOUTH/EAST
OF THE CWA BY THEN. AS A RESULT...HAVE ESSENTIALLY ZERO POPS
THROUGH THE NIGHT AREA- WIDE...AS THE TRAILING SOUTHWEST PORTION
OF THE POTENT MID LEVEL WAVE CONTINUES EXITING STAGE
RIGHT...REACHING AN AXIS FROM NORTHERN WI TO IL BY 12Z. IN ITS
WAKE...A PLEASANT AND EVEN SEASONABLY COOL NIGHT WILL SETTLE INTO
THE CENTRAL PLAINS. AT THE SURFACE...NORTH BREEZES WILL REALLY
LIGHTEN BY SUNSET...AND BECOME NEARLY CALM THROUGH THE NIGHT IN
SOME AREAS AS A 1023MB HIGH PRESSURE AXIS CENTERS ITSELF DIRECTLY
OVER THE AREA. THE COMBINATION OF THE INVADING DRY AIR...CLEARING
SKIES AND LIGHT BREEZES SHOULD SET THE STAGE FOR A RATHER COOL
NIGHT BY EARLY AUG STANDARDS. LEANED TOWARD THE LOWER END OF 12Z
MET/MAV GUIDANCE FOR LOWS...WHICH RESULTED IN LOWERING PREVIOUS
FORECAST BY 2-4 DEGREES MAINLY IN THE FAR NORTHWEST AND SOUTHERN
COUNTIES. THEREFORE...AM NOW ADVERTISING LOW-MID 50S ALL
AREAS...WITH TYPICAL COOLER SPOTS SUCH AS ORD AND THE PLATTE
VALLEY OF WESTERN DAWSON COUNTY VERY POSSIBLY TAGGING UPPER 40S.
FOR THIS TIME OF YEAR...DEFINITELY LIGHT JACKET WEATHER FOR THOSE
OUT AND ABOUT LATE TONIGHT/EARLY SUNDAY MORNING.
FOR THE SUNDAY DAYTIME 12Z-00Z PERIOD...LITERALLY KEPT POPS ZEROED
OUT CWA-WIDE...AS A BANNER DAY WITH VERY LITTLE...IF ANY CLOUDS IS
FORECAST. IN THE MID-UPPER LEVELS...THE DEPARTING SHORTWAVE WILL
REACH ALL THE WAY TO THE EASTERN GREAT LAKES BY LATE
AFTERNOON...WHILE THE SOUTHERN CONUS 500MB RIDGE AXIS EXPANDS
NORTH AND WEST IN COVERAGE A BIT...BECOMING CENTERED FROM CO/UT
TO OK/NORTHERN TX. THIS WILL LEAVE THE CWA IN FAIRLY LIGHT AND
VERY DRY WEST-NORTHWEST MID LEVEL FLOW. AT THE SURFACE...THE
AFOREMENTIONED RIDGE AXIS WILL START OUT CENTERED OVER THE
AREA...BUT GRADUALLY SLIDE EAST TO NEAR THE MO RIVER BY LATE
AFTERNOON. AS THE HIGH EDGES EAST...LIGHT SOUTHERLY BREEZES WILL
GRADUALLY OVERTAKE MUCH OF THE CWA FROM WEST TO EAST...EVENTUALLY
REACHING INTO THE 10-15 MPH RANGE IN FAR WESTERN COUNTIES...BUT
REMAINING VERY LIGHT/NEAR CALM ALL DAY IN THE FAR EAST NEAR HWY
81. ALTHOUGH THE LIGHT BREEZES/LACK OF MIXING WILL WORK AGAINST
MUCH OF A WARMUP OVER TODAY...PLENTIFUL SUNSHINE AND RELATIVELY
DRY AIR WILL WORK IN FAVOR OF IT. AS HAS BEEN THE CASE FOR SEVERAL
WEEKS NOW...NUMERICAL GUIDANCE HAS PROVEN DIFFICULT TO
EMPLOY...WITH THE MET AVERAGING TOO WARM AND THE MAV TOO COOL. OVERALL
THOUGH...WILL LEAN TOWARD THE WARMER END OF GUIDANCE...AND
ESSENTIALLY JUST BUMPED UP THE PREVIOUS FORECAST 1 DEGREE. THIS
YIELDS NEAR NORMAL HIGHS OF 86-88 MOST AREAS...AND 90-92 IN KS
ZONES AND FURNAS COUNTY AREA. LOWERED DEWPOINTS A BIT FROM
PREVIOUS FORECAST AS WELL...WITH ONLY MID-UPPER 40S SOUTHWEST AND
LOW-MID 50S SOUTHEAST. ALTHOUGH RELATIVE HUMIDITY VALUES COULD
DROP CLOSE TO THE 20 PERCENT CRITICAL FIRE WEATHER THRESHOLD IN A
FEW FAR SOUTHWEST COUNTIES...WINDS SPEEDS WILL FALL WELL SHORT OF
FIRE WEATHER CRITERIA.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY. MODELS NOT IN TOO BAD
OF AGREEMENT TO START OFF THE LONG TERM PERIOD...SHOWING SUNDAY
EVENING REMAINING UNDER ZONAL/WEAK NORTHWESTERLY FLOW IN THE UPPER
LEVELS...A RESULT OF A BROAD HIGH PRESSURE IN PLACE ACROSS THE
SCENTRAL/SWRN CONUS AND A TROUGH SHIFTING TOWARD THE EAST COAST.
DURING THE OVERNIGHT HOURS...THE FLOW DOES AMPLIFY SOME AS ANOTHER
TROUGH IS MAKING ITS WAY TOWARD THE WEST COAST...BUT NO NOTABLE
DISTURBANCES LOOK TO MOVE THROUGH AND DECIDED TO KEEP THE FORECAST
DRY. HOWEVER...MODELS DO SHOW THE SFC/LOWER LEVEL WINDS REMAINING
S/SWRLY OVERNIGHT...WITH INCREASING VALUES OF ELEVATED INSTABILITY
SHIFTING NORTH INTO THE REGION AS A STRONGER /30-35KT OR SO/ LLJ
DEVELOPS...MAINLY ACROSS THE HIGH PLAINS REGION. THE EDGE OF THIS
LLJ/INSTABILITY AXIS DOES LIE OVER THE WRN PORTIONS OF THE
CWA...AND MAY HAVE TO KEEP AN EYE ON THIS AREA FOR THE POTENTIAL
FOR PERHAPS SOME LIGHT PRECIP /BUT FORECAST SOUNDINGS ARE PRETTY
DRY IN THE LOWER LEVELS/...OR A LITTLE MORE IN THE WAY OF CLOUD
COVER.
INTO MONDAY/MONDAY NIGHT...THE MAIN STORY LIES WITH THE ARRIVAL OF A
MID/UPPER LEVEL WAVE...ASSOCIATED WITH A LOW PRESSURE SYSTEM LOCATED
UP NEAR THE HUDSON BAY. KEPT THE DAYTIME HOURS ON MONDAY
DRY...THOUGH A LITTLE MORE UNCERTAINTY ARISES TOWARD THE LATE
AFTERNOON HOURS...WITH THE ACCOMPANYING SURFACE FRONTAL BOUNDARY
LOOKS TO BE KNOCKING ON THE DOOR OF THE FAR NW CORNER OF THE CWA.
DID RAISE POPS A BIT DURING THE EVENING/OVERNIGHT HOURS ACROSS THE
N/NWRN PORTIONS OF THE CWA...BUT DIDNT MAKE MUCH CHANGE FURTHER
SOUTH. AHEAD OF THE FRONT ON MONDAY...EXPECTING INCREASED SOUTHERLY
WINDS...LIKELY A BIT GUSTY DURING THE AFTERNOON...AND WARMER
TEMPERATURES WITH HIGHS FORECAST TO REACH INTO THE MID/UPPER 90S FOR
MUCH/IF NOT ALL OF THE CWA. CONDITIONS DURING THE AFTERNOON HOURS
SHOULD REMAIN BELOW CRITICAL FIRE LEVELS...RHS COULD DROP INTO THE
LOWER/MID 20S ACROSS THE SOUTH...BUT SUSTAINED WIND SPEEDS ARE
EXPECTED TO REMAIN <20 MPH...THOUGH GUSTS COULD AT TIMES COME CLOSE
TO 25 MPH. WILL BE SOMETHING TO KEEP AN EYE ON IF MODELS HAPPEN TO
TREND UP WINDS/TREND DOWN DPS.
KEPT SOME LINGERING POPS IN DURING THE DAY ON TUESDAY...MAINLY
ACROSS THE SRN HALF OF THE CWA...IN CLOSER PROXIMITY TO WHERE THE
SFC BOUNDARY IS EXPECTED TO BE /SOMEWHERE NEAR OR SOUTH OF THE NEB
AND KS STATE LINE/. CONFIDENCE NOT THE HIGHEST...AS THE PLACEMENT OF
THE FRONT WILL BE DEPENDENT ON HOW THINGS PAN OUT MONDAY NIGHT.
WITH MOST OF THE CWA LOOKING TO BE ON THE NORTH SIDE OF THAT
BOUNDARY...MORE EASTERLY WINDS EXPECTED TO BE IN PLACE...AND
FORECAST HIGHS ARE A TOUCH COOLER THAN MONDAY...MORE IN THE
LOWER/MID 90S. BY 00Z WEDNESDAY...THE UPPER LEVEL PATTERN ACROSS
THE CONUS HAS BECOME MORE AMPLIFIED...WITH MORE SOLIDLY
NORTHWESTERLY FLOW IN PLACE ACROSS THE REGION AS THE RIDGE AXIS
EXTENDS FROM THE DESERT SW THROUGH THE ROCKIES AND INTO CANADA. THE
NOSE OF AN UPPER LEVEL JET STREAK ROUNDING THE TOP OF THE RIDGE AXIS
IS EXPECTED TO SHIFT INTO THE REGION FROM THE NW...BRINGING THE
POTENTIAL FOR MORE PRECIPITATION TUESDAY EVENING/OVERNIGHT. SIMILAR
TO MONDAY/MONDAY NIGHT...WHILE THERE IS INSTABILITY IN PLACE ACROSS
THE REGION...OVERALL DEEP LAYER SHEAR IS CERTAINLY NOT
OUTSTANDING...GENERALLY TOPPING OUT IN THE 25-30 KTS RANGE...SO
WHILE SOME THUNDERSTORMS COULD BE ON THE STRONGER SIDE...NOT
EXPECTING SEVERE WEATHER AT THIS POINT.
INTO WEDNESDAY...MODELS CONTINUE TO SHOW THE NOSE OF THIS UPPER
LEVEL JET IN THE AREA...AND DECIDED TO KEEP SOME LINGERING POPS IN
THE AREA...BUT CONFIDENCE IN CHANCES STICKING AROUND LONGER THAN
PERHAPS A FEW HOURS IN THE MORNING NOT EXACTLY HIGH. THAT LOWER
CONFIDENCE CONTINUES RIGHT ON THROUGH THE REMAINDER OF THE LONG TERM
PERIOD. THE UPPER LEVEL PATTERN REMAINS NORTHWESTERLY ACROSS THE
REGION WITH THE RIDGE STAYING IN PLACE OVER THE CENTRAL
ROCKIES...AND KEPT THE FORECAST DRY AT THIS POINT...WITH MODELS
SHOWING SOME DIFFERENCES WITH DISTURBANCES PASSING TO THE EAST OF
THE CWA...AND WHETHER WE SEE ANY PRECIP AS RESULT. WITH THE
RIDGE/WARMEST AIR REMAINING OFF TO THE WEST OF THE CWA...AND THE
POTENTIAL FOR AN ADDITIONAL FRONTAL PASSAGE...NOTABLY HIGHER
TEMPERATURES ARE NOT EXPECTED...WITH FORECAST HIGHS RANGING FROM
ROUGHLY THE MID 90S WED/THUR TO THE MID 80S TO LOWER 90S FRI/SAT.
&&
.PREV DISCUSSION... /ISSUED 1155 AM CDT SAT AUG 4 2012/
UPDATE...THE PRIMARY CHALLENGE FOR THE REST OF TODAY INVOLVES
WHETHER THERE IS MUCH RISK AT ALL FOR MEASURABLE RAIN...AND JUST
HOW COOL HIGH TEMPS MAY END UP BEING UNDER THE AREAS THAT HOLD
ONTO CLOUDS THE LONGEST. 1630Z RADAR IMAGERY AND VISIBLE SATELLITE
REVEAL A SCATTERED STREAM OF LIGHT SHOWERS/SPRINKLES LIKELY BASED
AROUND 700MB STREAMING INTO SOUTHWEST PORTIONS OF THE CWA FROM THE
WEST. THIS HIGH BASED ACTIVITY SEEMS FAIRLY WELL TIED TO A MODEST
CORRIDOR OF CONVERGENCE/FRONTOGENESIS EVIDENT AT 700MB AND ALSO ON
THE 315K ISENTROPIC SURFACE. THIS FORCING IS ALIGNED ALONG THE
SOUTHERN PERIPHERY OF THE MAIN MID LEVEL SHORTWAVE AXIS TRAILING
SOUTHWEST FROM THE PARENT STOUT VORT MAX NEAR THE MN/QUEBEC
BORDER. EXPECTATION BASED ON SHORT TERM TRENDS FROM THE LATEST
HRRR/RAP IS FOR MAINLY LIGHT HIGH BASED SHOWERS TO CONTINUE
SPREADING FROM WEST TO EAST TROUGH AT LEAST 21Z OR SO ACROSS AREAS
PRIMARILY SOUTH OF INTERSTATE 80...LIKELY AMOUNTING TO LITTLE MORE
THAN A BRIEF SPRINKLE MOST SPOTS. HOWEVER...LEFT AN ISOLATED
THUNDER AND EVEN A SMALL HAIL MENTION INTACT...JUST IN CASE A FEW
STRONGER STORMS ARE ABLE TO FLARE UP AND TAP INTO ELEVATED MUCAPE
POSSIBLY AS HIGH AS THE 500-1000 J/KG RANGE...BUT LIKELY LESS THAN
THIS. THE MOST FAVORABLE AREA FOR ONE OF THESE STRONGER
STORMS...SHOULD THEY EVEN DEVELOP...WOULD BE ACROSS A HANDFUL OF
FAR SOUTHEASTERN COUNTIES. OTHERWISE...CURRENT EXPECTATION IS
THAT ANY PRECIPITATION RISK FOR THE NEXT FEW DAYS WILL BE OVER
WITH BY...OR SHORTLY AFTER 21Z THIS AFTERNOON. TEMP WISE
TODAY...HAVE ESSENTIALLY LEFT PREVIOUS HIGH TEMPERATURES
UNCHANGED. ANTICIPATE THAT AT LEAST CENTRAL/NORTHWEST PORTIONS OF
THE CWA SHOULD SEE A RAPID CLEARING TREND AS THE AFTERNOON WEARS
ON...LIKELY ALLOWING TEMPS TO EVENTUALLY JUMP UP TO FORECAST
VALUES AROUND 83. HOWEVER...SOUTHEAST PORTIONS OF THE CWA THAT
WILL LIKELY REMAIN UNDER THE CLOUDS THE LONGEST COULD STRUGGLE TO
REACH THE FORECAST VALUES OF 82-84...AND AGREE WITH OVERNIGHT
FORECASTER THAT SOME SPOTS MAY NOT ESCAPE THE UPPER 70S. WILL HAVE
A BETTER HANDLE ON THIS BY AFTERNOON FORECAST ISSUANCE TIME.
OTHERWISE...INTRUSION OF DRIER AIR BEHIND THE COLD FRONT HAS BEEN
FAIRLY IMPRESSIVE WITH ORD DOWN TO 49 DEWPOINT NOW. AS A
RESULT...LOWERED AFTERNOON DEWPOINTS 6-8 DEGREES ACROSS MUCH OF
THE CWA...WITH COMFORTABLE 40S/LOW 50S DEWS LIKELY INTO MOST
COUNTIES BY MID-LATE AFTERNOON. NORTH BREEZES WILL CONTINUE
GUSTING AT LEAST 20-25 MPH THROUGH MID AFTERNOON...BEFORE STEADILY
DECLINING BEFORE SUNSET.
AVIATION...18Z KGRI TAF. VFR CEILING/VISIBILITY ARE FORECAST
THROUGH THE PERIOD. ESSENTIALLY CLEAR SKIES WILL DOMINATE THE AREA
THROUGH THE MAJORITY OF THE PERIOD...BUT FOR AT LEAST THE INITIAL
3-5 HOURS QUITE A BIT OF MID LEVEL CLOUD COVER WILL STREAM
OVER...ALONG WITH JUST A SLIGHT CHANCE OF BRIEF PASSING
SHOWERS...WHICH HAVE BEEN SUGGESTED WITH A VICINITY SHOWER
MENTION. SURFACE BREEZES WILL REMAIN NORTHERLY THROUGH TONIGHT IN
THE WAKE OF A SEASONABLY STRONG COLD FRONT. THE STRONGEST SPEEDS
WITH GUST POTENTIAL TO AROUND 20KT WILL OCCUR DURING THE FIRST FEW
HOURS OF THE PERIOD...BEFORE A STEADY SLACKENING OF SPEEDS
COMMENCES. FROM SUNSET THROUGH MID-DAY SUNDAY...SPEEDS SHOULD
AVERAGE UNDER 6KT AND BECOME A BIT VARIABLE IN DIRECTION WITH
TIME.
&&
.CLIMATE...TODAY/TONIGHT WILL LIKELY END UP BEING THE COOLEST
DAY/NIGHT AT GRAND ISLAND AND HASTINGS IN 6.5 WEEKS. BASED ON
FORECAST PROJECTIONS OVER THE NEXT FEW HOURS...THE CALENDAR DAY
HIGH TEMPERATURE AT BOTH GRAND ISLAND AND HASTINGS WILL END UP
SOMEWHERE BETWEEN 78-82 DEGREES...BUT IS GUARANTEED TO BE AT LEAST
78 BECAUSE THIS VALUE WAS REACHED SHORTLY AFTER MIDNIGHT BEFORE
THE COLD FRONT INVADED. FOR GRAND ISLAND...A HIGH OF 79-82 DEGREES
WOULD RESULT IN THE COOLEST DAILY HIGH SINCE JUNE 20TH...WHEN IT
TOPPED OUT AT 79. FOR HASTINGS...A HIGH OF 78-79 DEGREES WOULD
ALSO RESULT IN THE COOLEST DAY SINCE JUNE 20TH...WHEN IT REACHED
78. TURNING TO LOW TEMPERATURES TONIGHT...THE CURRENT FORECAST FOR
BOTH GRAND ISLAND AND HASTINGS CALLS FOR 55. THIS IS ONLY 3
DEGREES ABOVE HASTINGS AUGUST 5TH RECORD LOW OF 52...AND 4 DEGREES
ABOVE THE GRAND ISLAND RECORD LOW OF 51...BOTH SET IN 1994.
ASSUMING IT DIPS TO AT LEAST 57 DEGREES OVERNIGHT...THIS WILL BE
THE COOLEST LOW TEMP IN BOTH CITIES SINCE JUNE 21ST...WHEN GRAND
ISLAND BOTTOMED OUT AT 52 AND HASTINGS 51.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM/AVIATION...PFANNKUCH
LONG TERM...ADO
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
115 PM EDT SAT AUG 4 2012
.SYNOPSIS...
BUILDING BERMUDA HIGH PRESSURE WILL BRING TYPICAL SUMMERTIME
WEATHER OVER THE WEEKEND...WITH NEAR NORMAL TEMPERATURES AND
ISOLATED TO SCATTERED THUNDERSTORMS IN THE AFTERNOON TO EARLY
EVENINGS. A WEAK TROPICAL WAVE COULD BRING COASTAL SHOWERS TO
THE AREA ON SUNDAY. A SURFACE TROUGH MAY PROVIDE A FOCUS FOR
INLAND STORMS ON MONDAY...BUT WILL WEAKEN AS HIGH PRESSURE
BUILDS INTO THE AREA FROM THE WEST NEXT TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1030 AM SATURDAY...DEEP TROPICAL SOUTHEASTERLY FLOW DEVELOPING
ACROSS THE REGION TODAY WHILE MID LEVEL LOW OVER THE REGION BOTH
LIFTS OUT TO THE NORTH AND WEAKENS. THIS LEAVES THE COASTAL
CAROLINAS WITH LITTLE IN THE WAY OF FORCING FOR PRECIP OTHER THAN
FRICTIONAL CONVERGENCE ALONG THE COAST. 12Z WRF SHOWING JUST A FEW
TROPICAL SHOWERS MATERIALIZING OVER NC COASTAL ZONES. HRRR RUNS GO
BACK AND FORTH BETWEEN SHOWING MINIMAL COVERAGE AND NO COVERAGE AT
ALL.
AS OF 700 AM SATURDAY...LOOK FOR MORE OF A TROPICAL INFLUENCE ACROSS
THE REGION THIS FORECAST PERIOD. THE WESTERN ATLANTIC HIGH TO FLEX
ITS MUSCLES AND RIDGE ACROSS THE FA BOTH SFC AND ALOFT THRU THE
PERIOD. AN INVERTED SFC TROF TO PASS OVER THE BAHAMAS TODAY...AND
PROGGED TO TRACK NW TO AND ACROSS THE NORTHERN FLORIDA PENINSULA
TONIGHT INTO SUNDAY. HOURLY NAMBUFR SOUNDINGS INDICATE A GENERAL
INCREASE OF PWS TO AROUND 2 INCHES TONIGHT INTO SUNDAY. WINDS THRU
THE ATM COLUMN TO BECOME BASICALLY ONSHORE INDICATIVE OF A TROPICAL
INFLUENCE ACROSS THE FA. THE SEA BREEZE OR RESULTANT WIND TYPE
CONVECTION WILL COMMENCE BY MID-LATE THIS MORNING...AND TRACK INLAND
THROUGHOUT THE DAY AS ADVERTIZED BY THE LATEST HRRR MODEL RUNS.
MODEL SOUNDING DATA INDICATE PWS OF 2 INCHES...AND A SLOW MOVEMENT
OF THE CONVECTION...BASICALLY BETWEEN 5 AND 10 KT. AS A RESULT...THE
MAIN THREAT FROM TODAYS CONVECTION WILL BE FROM HEAVY RAIN. FOR
TONIGHT...ONSHORE MOVEMENT OF PCPN DURING THE PRE-DAWN HRS OF SUNDAY
TO OCCUR AS A MUCH DEEPER ONSHORE FLOW EVOLVES THRU THE ATM COLUMN.
WILL ILLUSTRATE LOW CHANCE POPS FOR THE COASTAL AREAS. COMPROMISED
BETWEEN THE VARIOUS MODEL MOS GUIDANCE FOR MAX/MIN TEMPS THRUOUT THE
NEAR TERM.
&&
.SHORT TERM /SUNDAY MORNING THROUGH MONDAY NIGHT/...AS OF 3:00 AM
SATURDAY...MID LEVEL RIDGING WILL CONTINUE TO BE THE MAIN WEATHER
MAKER SUNDAY. MONDAY WILL FEATURE A SLIGHT CHANGE AS THE RIDGE
RETREATS TO THE EAST AND A FRONT MOVES AT LEAST CLOSER TO THE AREA
FROM THE NORTHWEST. THIS ALLOWS POPS TO INCREASE FROM
ISOLATED/SLIGHT CHANCE SUNDAY TO CHANCE MONDAY PRIMARILY MONDAY
AFTERNOON. THERMAL PROFILES ARE ALMOST IDENTICAL FOR BOTH AFTERNOONS
AND MODEL GUIDANCE IS IN EXCELLENT AGREEMENT ON DAYTIME HIGHS ALMOST
SPOT ON CLIMATOLOGY WITH OVERNIGHT LOWS JUST ABOVE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3:00 AM SATURDAY...MID LEVEL PATTERN WILL FEATURE SUBTLE EAST
COAST TROUGHING WITH RIDGING CENTERED ACROSS THE ROCKIES AND
ACROSS THE CENTRAL ATLANTIC. AT THE SURFACE A WEAK FRONT/PIEDMONT
TROUGH WILL BE THE FEATURES OF NOTE. THE FRONT APPEARS TO STALL AS
WOULD BE EXPECTED THIS TIME OF YEAR TO THE WEST/NORTHWEST. TOUGH
TO ASCERTAIN WHICH DAY WILL FEATURE THE BEST CHANCE FOR RAIN AND
BASICALLY MAINTAINED THE DIURNAL CYCLE AND CHANCE VALUES. IF
ANYTHING...THURSDAY AND FRIDAY APPEAR SLIGHTLY MORE CONDUCIVE PER
THE FAVORED ECMWF HIGH RESOLUTION FROM HPC. NO CHANGES TO
TEMPERATURE FORECAST WHICH SHOULD HOVER AROUND CLIMATOLOGY.
&&
.AVIATION /18Z SATURDAY THROUGH WEDNESDAY/...
AS OF 18Z...TROPICAL ENVIRONMENT WITH SOUTHEAST FLOW THROUGH 500 MB.
THIS REGIME WILL GIVE US SCATTERED CONVECTION ALONG THE RESULTANT
THIS AFTERNOON. GIVEN THE UPPER FLOW...SEA BREEZE CONVECTION SHOULD
GENERALLY REMAIN INLAND FROM THE COASTAL TERMINALS. MOST OF THE
STUFF WILL BE FAIRLY LOW TOPPED...HOWEVER SCATTERED THUNDER IS
EXPECTED. SOUTHEAST WINDS WILL CONTINUE INTO THE EVENING HOURS.
SUNDAY...SYNOPTICALLY SIMILAR TO TODAY...WITH AFTERNOON THUNDER
PERSISTING.
EXTENDED OUTLOOK...CHANCE OF MORNING MVFR/IFR VSBYS FROM BR/FG
WITH A CHANCE OF SHOWERS AND THUNDERSTORMS EACH DAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM SATURDAY...SEAS JUST 2.5 FT ALL THE WAY OUT AT BUOY
41013 WITH DOMINANT PERIOD 8-9 SECONDS INDICATIVE OF SWELL ENERGY.
JUST A SUBLET CHANGE TO SEAS FORECAST FROM A STRAIGHT 3 FT TO THAT
OF 2 TO 3 FT AS A THOUSAND MILE SOUTHEAST FETCH CONTINUES INTO THE
CAROLINAS.
AS OF 700 AM SATURDAY...THE WESTERN ATLANTIC HIGH...SFC AND ALOFT...
WILL GOVERN THE ILM COASTAL WATERS. THE SFC RIDGE AXIS EXTENDING SW
FROM THE CENTER OF THIS HIGH...WILL CROSS THE WATERS THRU THE
PERIOD. THE ACTUAL POSITIONING OF THIS AXIS ACROSS THE LOCAL WATERS
WILL DETERMINE WIND DIRECTIONS. LOOK FOR SE TO S WIND DIRECTIONS
SOUTH OF THE AXIS AND S TO SSW NORTH OF THE AXIS. THE SFC PG WILL BE
CONDUCIVE FOR 10-15 KT WIND SPEEDS. WILL HAVE TO MONITOR THE
STRENGTH AND MOVEMENT OF AN INVERTED TROF OF LOW PRESSURE FROM THE
BAHAMAS TO AND ACROSS THE NORTHERN FLORIDA PENINSULA ON SUNDAY. WIND
SPEEDS MAY INCREASE TO A SOLID 15 KT SOUTH OF CAPE FEAR. SIGNIFICANT
SEAS WILL BE RULED BY A 2 TO 3 FT ESE GROUND SWELL EXHIBITING 8-9
SECOND PERIODS. FOR TONIGHT...SIG SEAS TO BUILD TO 3 TO 4 FT DUE TO
THE CLOSER PROXIMITY OF THE INVERTED SFC TROF.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3:00 AM SATURDAY...BERMUDA HIGH PRESSURE AND SEA BREEZE WILL
DOMINATE THE COASTAL WATERS THROUGH THE PERIOD WITH SLIGHTLY MORE
INFLUENCE FROM A FRONT MOVING CLOSER LATE MONDAY. WIND SPEEDS MAY
ADD A KNOT OR TWO AT THIS TIME. SEAS ARE RATHER UNEVENTFUL AS WELL
WITH 2-3 FEET FOR THE MOST PART. A FEW FOUR FOOTERS CANNOT BE
RULED OUT EARLY ACROSS THE OUTER WATERS.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3:00 AM SATURDAY...SUMMERTIME PATTERN CONTINUES ACROSS THE
COASTAL WATERS FOR THE MARINE COMMUNITY. SOUTHWEST WINDS OF 10-15
KNOTS WILL PREVAIL WITH A SLIGHT BACKING DURING THE DAY COURTESY OF
THE SEA BREEZE. NO REAL SIGNAL FROM TROPICAL ACTIVITY VIA THE
WAVEWATCH GUIDANCE AS SEAS REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...43
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
355 PM EDT SAT AUG 4 2012
.SYNOPSIS...
MUGGY AUGUST AIR THROUGH WEEKEND. WITH A LOCAL DOWNPOUR POSSIBLE.
MORE WIDESPREAD AND ORGANIZED CONVECTION LIKELY SUNDAY...WELL AHEAD
OF COLD FRONT. DRIER AIR TRIES TO CREEP SOUTH MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX
SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE
POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR.
NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT
A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER
STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES
CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS.
EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY
AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH
FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE
STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE
PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES
ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD
EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR
THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE
BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD
TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING.
STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD
MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER
STORMS.
BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN
PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES.
WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW
LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL
REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS
FORECAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
WE ARE HOPING THE PREFRONTAL CONVECTION DOES NOT ORIENT MORE EAST TO
WEST...BUT THE FLASH FLOOD WATCH WAS POSTED EARLY...FOR THAT
POSSIBILITY. AS WE HEAD INTO SUNDAY EVENING...OUR SOUTHERN COUNTIES
SEEM TO BE MORE VULNERABLE TO SOME TRAINING...DESPITE THE 25 TO 30
KNOT CELL MOVEMENT THAT WE ARE EXPECTED.
WILL BASE FORECAST ON SURFACE FRONT FROM NEAR EKN TO CRW TO SOUTH OF
HTS AT 12Z MONDAY. SO HAD TO LEAVE SOME CHANCE POPS ALONG THAT
FEATURE. PICTURING LOW CLOUDS ALONG THAT FRONT TOO. PROBABLY MOSTLY
JUST LINGERING RAIN SHOWERS RATHER THAN THUNDER.
PROBLEM THEN BECOMES...HOW LONG TO LINGER SOME 20/30 POPS IN OUR
EXTREME SOUTH INTO TUESDAY. WE ARE TYPICALLY LEARY OF THE DRIER AIR
IN THE LOW LEVELS MAKING IT THROUGH THE SOUTHERN MOUNTAINS. SO EVEN
THOUGH THE MID LEVELS SHOULD DRY OUT...WILL NOW HOLD ONTO SOME 20/30
POPS IN SW VIRGINIA TO NEAR BECKLEY FOR TUESDAY.
THERE COULD BE WIDESPREAD FOG MONDAY NIGHT FROM EKN TO CRW INTO THE
COAL FIELDS. YET...BEING THE THIRD NIGHT INTO THE FUTURE...WILL HOLD
OFF INCLUDING THOSE SPECIFICS FOR NOW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
12Z GFS AND 12Z ECMWF SOLUTIONS CONTINUE TO AGREE THAT THE MID LEVEL
RIDGE...BAKING THE PLAINS THIS SUMMER...WILL SLIDE BACK WEST INTO
THE GREAT BASIN...WITH A STRONG TROF SWINGING THROUGH OUR VICINITY
ON DAY 7...WITH THE SURFACE FRONT LIKELY AHEAD OF IT...ON DAY
6/FRIDAY.
PROBLEM FOR WEDNESDAY AND THURSDAY IS THE DEEP MOISTURE LINGERING TO
OUR SOUTHEAST. WILL TRY TO HOLD WEDNESDAY DRY MAINLY FOR COUNTIES
NORTH OF A HTS-CRW-EKN LINE...WITH SOME 20/30 POPS ALONG OUR
SOUTHEASTERN COUNTIES WEDNESDAY. WENT ALONG WITH HPC MEDIUM RANGE
CHANCE POPS FOR THURSDAY AND FRIDAY...WITH A COOL DOWN FOR SATURDAY.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND
ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE
AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO
THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS
POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND
REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED
MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN.
TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND
THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE
FROM WEST TO EAST AS COLD FRONT APPROACHES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY
VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM
OVERNIGHT IF CLOUD BREAKS DEVELOP.
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 20 21 22 23 00 01 02 03 04 05 06 07
EDT 1HRLY 16 17 18 19 20 21 22 23 00 01 02 03
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 M M 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 SUNDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT.
IFR IN LOW STRATUS POSSIBLE NEAR SURFACE FRONT MONDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR WVZ005-006-013>020-024>040-046-047.
OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR OHZ087.
KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ
SHORT TERM...KTB/ARJ
LONG TERM...KTB
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
225 PM EDT SAT AUG 4 2012
.SYNOPSIS...
WARM AND HUMID...WITH SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED
THIS AFTERNOON. A COLD FRONT BRINGS WIDESPREAD AND STRONGER
STORMS...WITH HEAVY RAIN AND SEVERE WEATHER SUNDAY AND SUNDAY NIGHT.
&&
.NEAR TERM /THROUGH SUNDAY/...
CONVECTION CURRENTLY DEVELOPING IN ASSOCIATION WITH WEAK VORT MAX
SHOWING UP ON RAP MOVING INTO CWA FROM THE WEST. DOWNPOURS WILL BE
POSSIBLE WITH THESE STORMS...AND ISOLATED FLASH FLOODING MAY OCCUR.
NOT EXPECTING FLASH FLOOD THREAT TO BE WIDESPREAD ENOUGH TO WARRANT
A SHORT FLASH FLOOD WATCH THOUGH THIS EVENING. TOMORROW IS ANOTHER
STORY...MOISTURE CONTINUES TO INCREASE OVERNIGHT...WITH PWAT VALUES
CLIMBING TO OVER 2.25 INCHES BY 18Z SUNDAY ON THE NAM AND GFS.
EXPECT WIDESPREAD PRECIPITATION...WITH VERY HEAVY RAINFALL SUNDAY
AFTERNOON INTO SUNDAY NIGHT...AND OPTED TO ISSUE A FLASH FLOOD WATCH
FOR LINE ROUGHLY HTS TO CKB AND SOUTH. ONE THING TO WATCH WILL BE
STORM SPEEDS...WITH 20-30KTS MID LEVEL FLOW...STORMS WILL BE
PROGRESSIVE...BUT WITH FLASH FLOOD GUIDANCE BETWEEN 1.5 AND 2 INCHES
ACROSS A LOT OF THE WATCH AREA...EVEN STORMS THAT ARE MOVING COULD
EASILY REACH THIS THRESHOLD. PLUS...IF ANY TRAINING CELLS OCCUR
THREAT WILL INCREASE GREATLY. AS FOR SEVERE THREAT...MODELS HAVE
BEEN BACKING OFF ON INSTABILITY A BIT. THINK THIS IS A GOOD
TREND...DUE TO MORE CLOUDS LEADING TO LESS HEATING.
STILL...1500-2000 J/KG CAPE SHOULD BE ENOUGH TO TAP INTO GOOD
MID-LEVEL FLOW AND PRODUCE STRONG TO SEVERE WIND GUSTS IN THE TALLER
STORMS.
BLENDED IN MET GUIDANCE FOR TEMPS OVERNIGHT...AS IT HAS BEEN
PERFORMING QUITE WELL LATELY...WHICH RESULTED IN MINIMAL CHANGES.
WITH MORE CLOUDS AROUND...BLENDED IN THE MAV FOR HIGHS TOMORROW
LIKING ITS DEPICTION OF COOLER TEMPS IN SE OHIO WHERE PRECIP WILL
REACH FIRST. THIS RESULTED OVERALL IN A BIT COOLER DAY THAN PREVIOUS
FORECAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
A COLD FRONT APPROACHES TO SOUTHEAST OH SUNDAY. MODELS ARE IN GOOD
AGREEMENT TIGHTENING THE PRESSURE GRADIENT AND FLOW AT H850 FROM THE
SOUTHWEST...AND BRINGING MOISTURE ADVECTION TO THE AREA EARLY
SUNDAY MORNING. THETA-E VALUES REACHING 340K SUGGEST VERY JUICY
AIR CAPABLE TO PRODUCE HEAVY RAIN AND STRONG STORMS WILL SPREAD
EAST ACROSS WV DURING THE PEAK OF DIURNAL HEATING. THIS MOISTURE
IS ALSO NOTED IN PRECIPITABLE WATER VALUES EXCEEDING 2.2 INCHES.
ALTHOUGH EQUILIBRIUM LEVEL EXCEEDING 40 KFT...A THIN CAPE SOUNDING
AND LOW UNIDIRECTIONAL DEEP LAYERED SHEAR VALUES SUGGEST WATER
LOADING EFFECTS WITH TALL STORMS. THESE CONDITIONS COULD REDUCE
SEVERE UPDRAFTS...BUT WILL PROMOTE VERY HEAVY DOWNPOURS. STRONG
H5 VORTICITY MAXIMUM REACHES SOUTHEAST OH BY MON 00Z...SUGGESTING
GOOD DYNAMICS COULD ENHANCE STORMS DURING THE AFTERNOON HOURS.
THEREFORE...EXPECT CONVECTION FIRING UP AHEAD OF THE FRONT BY MID
DAY SUNDAY...AND SPREAD EAST NORTHEAST...WITH CONTINUING CONVECTION
DEVELOPING ACROSS SOUTHEAST OH WITH THE STRONGER UPPER FORCING
APPROACHING THROUGH THE EVENING.
ALTHOUGH THERE IS A SLIGHT RISK FOR SEVERE STORMS ACROSS THE ENTIRE
AREA...WILL ALSO WATCH FOR WATER PROBLEMS WITH THE AFOREMENTIONED
SCENARIO. KEPT CAP POPS SUNDAY AFTERNOON ACROSS SOUTHEAST
OH...SPREADING EAST THROUGH SUNDAY NIGHT. THE FRONT SEEMS TO SLOW
DOWN AS IT ENTERS WV...AND LINGER ACROSS THE SOUTHERN COAL FIELDS
AND CENTRAL MOUNTAINS THROUGH TUESDAY MORNING.
A FLASH FLOOD WATCH MAY BE REQUIRED FOR SUNDAY.
KEPT HIGH TEMPS IN THE 80S SUNDAY AND MONDAY PER ABUNDANT CLOUDS
AND RAINFALL EXPECTED. KEPT LOWS IN THE LOWER 70S SUNDAY NIGHT PER
ABUNDANT MOISTURE AND LACK OF EXTRA PUSH OF DRIER AIR TO DISPLACE
HIGH DEWPOINTS...BUT IN THE MID 60S MONDAY NIGHT PER CLEARING
SPREADING FROM THE WEST AND ASSOCIATED RADIATIONAL COOLING.
AREAS OF DENSE FOG WILL BE POSSIBLE UNDER CLEAR SKIES AND AREAS
THAT RECEIVE RAINFALL TUESDAY MORNING.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
GOING WITH HPC. NORTHWEST FLOW ALOFT STRENGTHENS...WITH THE HOT AND
HUMID AIR BEING SHUNTED TO THE SOUTH. TRANQUIL PERIOD OF DRY AND
NEAR SEASONABLE TEMPERATURES DOMINATE THIS PERIOD AS WEAK HIGH
PRESSURE DOMINATES. GOOD MODEL AGREEMENT ON THIS SCENARIO.
BY FRIDAY...NEXT SYSTEM APPROACHES AS THE UPPER FLOW BECOMES MORE
WESTERLY AND ALLOWS THE HEAT AND MOISTURE TO RETURN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
CONVECTION JUST BEGINNING TO FORM ACROSS THE EASTERN MOUNTAINS...AND
ALSO IN EASTERN KY. EXPECT ADDITIONAL DEVELOPMENT THROUGH THE
AFTERNOON...WITH SCATTERED SHOWERS AND THUNDERSTORMS LINGERING INTO
THE EVENING. KEPT EVERYTHING VFR FOR TODAY...HOWEVER BRIEF MVFR IS
POSSIBLE IN THE STRONGER CELLS. WITH MORE CLOUDS AND SOME WIND
REMAINING OVERNIGHT...DO NOT EXPECT DENSE FOG TO FORM. WILL INCLUDED
MVFR FOG TONIGHT IN MOST SHELTERED MOUNTAIN VALLEYS LIKE KEKN.
TOWARDS THE END OF THE TAF PERIOD...EXPECT SHOWERS AND
THUNDERSTORMS...WITH HEAVY RAIN POSSIBLE...TO BE ON THE INCREASE
FROM WEST TO EAST AS COLD FRONT APPROACHES.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z SUNDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: TIMING OF SHOWERS AND THUNDERSTORMS TODAY MAY
VARY...WITH AMENDMENTS POSSIBLE. ADDITIONAL POCKETS OF FOG MAY FORM
OVERNIGHT IF CLOUD BREAKS DEVELOP.
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 M M H H H M M 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 SUNDAY...
BRIEF IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS INTO SUNDAY NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR WVZ005-006-013>020-024>040-046-047.
OH...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR OHZ087.
KY...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR KYZ101>103-105.
VA...FLASH FLOOD WATCH FROM SUNDAY MORNING THROUGH LATE SUNDAY
NIGHT FOR VAZ003-004.
&&
$$
SYNOPSIS...ARJ/MZ
NEAR TERM...MZ
SHORT TERM...ARJ
LONG TERM...JMV
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
420 PM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS...SOME OF WHICH MAY BE STRONG TO
SEVERE ON SUNDAY...BEFORE DRIER AIR BUILDS IN FOR EARLY NEXT
WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE
MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH
INHIBITION DIMINISHING RAPIDLY.
HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS
AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS
AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z.
AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST
AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF
THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN
DAMAGING WINDS.
ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF
THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE
MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE ATLANTIC WILL
SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE NORMAL PW INTO
OUR REGION. HIGH PW VALUES ARE LIKELY IN THE STRONG FLOW AHEAD OF
THE COLD FRONT. WHILE THE STRONGEST FLOW WILL LIKELY LIFT NE OF
OUR AREA...THE FLOW WILL BE RATHER STRONG FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
FROM MID AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS...FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH WILL
REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING SEGMENTS
HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 10 PM IN EAST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
BY MONDAY MORNING...COLD FRONT WILL BE JUST SE OF CWA. WILL TAKE
SOME TIME TO CLEAR OUT RESIDUAL MOISTURE IN SOUTHEAST. BUT WITH
WESTERLY WINDS...DRIER AIR WILL EVENTUALLY WORK INTO THE BOUNDARY
LAYER IN THE SE. PW FALLS BELOW NORMAL STATE WIDE MONDAY.
CENTER OF SFC HIGH SETTLES OVER PA MON NIGHT/TUE KEEPING FORECAST
DRY. WEAK WAVE OVER SE U.S. SLIDES UP THE COAST FOR
WED/THU...NUDGING MOISTURE BACK INTO CWA. SO INTRODUCED SLIGHT
CHANCE FOR A TSTM WED/THU AS HUMIDITY BEGINS TO INCREASE. MORE
POTENT TROUGH APPROACHES IN NW FLOW FOR THU NIGHT-FRI NIGHT.
MODELS HANDLING THIS FEATURE WELL...THOUGH GFS TRIES TO LIFT
TROUGH NORTHWARD. EITHER WAY...CHANCE OF SHOWERS/TSTMS FITS THE
BILL BEFORE A MAINLY DRY WEEKEND.
TEMPERATURES WILL BE NEAR NORMAL TO START THE WEEK...THEN SLOWLY
RISE BACK ABOVE NORMAL FOR MIDWEEK. AS HUMIDITY INCREASES LATE
WEEK AHEAD OF APPROACHING TROUGH...TEMPS AGAIN GET A BIT MUGGY -
EVEN THOUGH THEY REMAIN JUST A FEW DEGREES ABOVE NORMAL.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS
SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME
HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND
OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS
FROM STORMS TAKE PLACE.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...RXR
LONG TERM...RXR
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
159 PM EDT SAT AUG 4 2012
.SYNOPSIS...
AN APPROACHING COLD FRONT WILL BRING AN INCREASE IN HUMIDITY AND
THE CHANCE OF SHOWERS AND STORMS THROUGH SUNDAY...BEFORE DRIER AIR
BUILDS IN FOR EARLY NEXT WEEK.
OVERALL THE PATTERN FOR EASTERN NORTH AMERICA IS IN TRANSITION
WITH THE EXPECTED DEVELOPMENT OF A BROAD TROUGH OVER THE NEXT 4 TO
8 DAYS.
&&
.NEAR TERM /THROUGH TONIGHT/...
SHOWERS AND STORMS WILL CONTINUE TO POP UP INTO THE EVENING IN THE
MOIST SOUTHWESTERLY FLOW. MESO ANAL SHOWS CAPES TOPPING 4000J WITH
INHIBITION DIMINISHING RAPIDLY.
HAVE TRIED TO FASHION THE NEAR TERM POPS TO CURRENT RADAR TRENDS
AND HRRR OUTPUT OVER THE NEXT SEVERAL HOURS. THESE KEEP SHOWERS
AND STORMS INTO THE EVENING BEFORE QUIETING DOWN AFTER 03Z.
AIRMASS IS VERY SOUPY WITH PWATS OVER 1.5" FOR MUCH OF THE FCST
AREA. CAN EASILY SEE 1-2 INCH PER HOUR RAINFALL RATES IN SOME OF
THE MORE ROBUST STORMS...ALONG WITH LOCALLY GUSTY POSSIBLY EVEN
DAMAGING WINDS.
ACTIVITY SHOULD DIMINISH TOWARD MIDNIGHT WITH PATCHY FOG AHEAD OF
THE FRONT IS AGAIN A POSSIBILITY LATER AT NIGHT. IT WILL BE QUITE
MUGGY WITH LOWS A FEW DEG EITHER SIDE OF 70 EVERYWHERE.
&&
.SHORT TERM /SUNDAY/...
SUNDAY THE FRONTAL SYSTEM TO OUR WEST AND THE RIDGE OVER THE
ATLANTIC WILL SEND A DEEP PLUME OF MOISTURE WITH 2-3 SIGMA ABOVE
NORMAL PW INTO OUR REGION. HIGH PW VALUES ARE LIKELY IN THE
STRONG FLOW AHEAD OF THE COLD FRONT. WHILE THE STRONGEST FLOW
WILL LIKELY LIFT NE OF OUR AREA...THE FLOW WILL BE RATHER STRONG
FOR EARLY AUG.
CAPE VALUES ARE GOOD FOR SEVERE WEATHER BUT NOT OVERLY IMPRESSIVE.
BUT OVER 20KTS OF 1KM SHEAR WITH 1200 TO 1800JKG-1 IMPLIES DEEP
UPDRAFTS AND GOOD SHEAR. THIS SHOULD FAVOR THE DEVELOPMENT...MAINLY
IN THE AFTERNOON INTO EVENING OF STRONG TO POTENTIAL SEVERE
THUNDERSTORMS. FAVORING MORE LINEAR SYSTEMS WITH POTENTIAL BOW
DEVELOPMENT. MOST GUIDANCE SHOWS STRONG LOW-LEVEL SHEAR WHICH
WILL REQUIRE MONITORING. MULTI-CELLULAR DAY LIKELY WITH BOWING
SEGMENTS HIGH PROBABILITY THINKING AT THIS TIME.
MOISTURE FLUX...OFTEN ALIGNS WELL WITH OUR BETTER SEVERE EVENTS
PEAKS 1800 UTC SUNDAY TO ABOUT 0000 UTC MONDAY. GOOD BET STRONG
STORMS FROM ABOUT 2 PM SUNDAY UNTIL 8 PM IN EAST. UPPED POPS IN
AFTERNOON INTO 80S BUT KEPT CLOSE TO NEIGHBORS FOR COLLABORATION.
PROBABLY NEED 90S IN THERE!
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
GEFS/SREF/GFS ALL SLOW TO CLEAR OUT THE RESIDUAL MOISTURE MONDAY
MORNING IN SOUTHEAST. BUT WINDS ARE WESTERLY. MAY TAKE UNTIL MID-
MORNING MONDAY TO GET THE DRY AIR INTO THE BOUNDARY LAYER. BUT PW
FALLS BELOW NORMAL STATE WIDE MONDAY.
KEPT POPS LOWER THAN GUIDANCE THROUGH WEDNESDAY AND GOT RID OF
SHOWERS AS THE PW VALUES ARE NEAR TO SLIGHTLY BELOW NORMAL.
PW IS NEAR NORMAL BY THURSDAY INTO SATURDAY SO KEPT CLOSE TO
GUIDANCE.
TEMPERATURE-WISE...850 HPA TEMPERATURES MAINLY NEAR NORMAL. SLIGHT
SURGE OF CLOSE TO 1 SIGMA ABOVE NORMAL WEDNESDAY AHEAD OF WHAT
MODELS IMPLY WOULD BE A SECONDARY COLD FRONT TAKING THE EDGE OF A
BIT MORE THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
LOCALIZED REDUCED CONDITIONS CAN BE EXPECTED INTO THE EVENING AS
SHOWERS AND THUNDERSTORMS CONTINUE TO POP UP UNDER DAYTIME
HEATING. STORM OVER MDT HAS CAUSED LIFR IN THE HEAVY RAIN...AND
OTHER TERMINALS CAN EXPECT SIMILAR CONDITIONS WHERE DIRECT HITS
FROM STORMS TAKE PLACE.
OUTLOOK...
.SUN...A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS...ESPECIALLY
SUNDAY PM AS A COLD FRONT MOVES THROUGH.
.MON...CHC OF A SHOWER OR STORM EARLY...THEN MAINLY VFR.
.TUES-THU...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LAMBERT/MARTIN
LONG TERM...GRUMM/MARTIN
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
412 PM EDT SAT AUG 4 2012
.SYNOPSIS...
A WEAK COLD FRONT WILL APPROACH THE APPALACHIANS LATE ON SUNDAY
AND SLOWLY MOVE THROUGH THE REGION ON MONDAY. THIS FRONT WILL
PROVIDE THE TRIGGER FOR MORE WIDESPREAD SHOWERS AND THUNDERSTORMS...
SOME WITH VERY HEAVY RAINFALL. THE FRONT WILL DRIFT INTO THE
CAROLINAS BY TUESDAY AND DISSIPATE...BUT LINGERING MOISTURE BEHIND
IT WILL ALLOW SOME SCATTERED SHOWERS AND THUNDERSTORMS TO CONTINUE
THROUGH MUCH OF NEXT WEEK.
&&
.NEAR TERM /TONIGHT THROUGH SUNDAY/...
AS 0F 205 PM EDT SATURDAY...
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPED IN THE MOIST AND
UNSTABLE AIR ACROSS OUR REGION THIS AFTERNOON. VORT LOBE WILL MOVE
ACROSS THE APPALACHIANS ENHANCING SHOWERS AND THUNDERSTORMS. THE
WRFARW-RNK...HRRR...NAM...RUC AND GFS KEEP SCATTERED STORMS THIS
EVENING INTO TONIGHT. ANY SLOW MOVING THUNDERSTORM MAY PRODUCE HEAVY
RAIN. FLASH FLOOD GUIDANCE IS RUNNING ABOUT 2 INCHES AN HOUR IN THE
MTNS AND 3 INCHES AN HOUR IN THE PIEDMONT. LOCAL FLOODING PROBLEMS
MAY BE A PROBLEM WITH TRAINING OF THUNDERSTORMS.
WITH THE LOW LEVEL FLOW FROM THE SOUTH...EXPECT THE GREATEST
CONVERGENCE ALONG THE BLUE RIDGE MOUNTAINS . SECONDARY AREA OF LOW
LEVEL CONVERGENCE LIKELY TO DEVELOP THIS AFTERNOON INTO THIS EVENING
OVER THE PIEDMONT. BOTH THE RUC AND NAM SHOWED SOME DEVELOPMENT OVER
THE EAST THIS EVENING.
LEANED TOWARDS THE NAM FOR TONIGHT POPS WITH ACTIVITY LINGER WELL
INTO THE OVERNIGHT AIDED BY CONTINUED MOIST LOW LEVEL MOISTURE
TRANSPORT INTO THE AREA UNDERNEATH NEARLY STATIONARY DISTURBANCE
ALOFT. WENT WITH LOWS CLOSE TO THE ADJMETBC WITH READINGS FROM THE
MID 60S IN THE MOUNTAINS TO THE LOWER 70S IN THE SOUTHEAST UNDER A
BLANKET OF CLOUDS AND ELEVATED DEWPOINTS.
UNSETTLED WEATHER WILL CONTINUE ON SUNDAY AHEAD OF APPROACHING
FRONTAL BOUNDARY COMING OUT OF OHIO VALLEY. SOME INCREASE IN SHEAR
AND SLIGHTLY STEEPER LAPSE RATES SUGGEST A BETTER SEVERE POTENTIAL
AS WELL...WITH MORE ORGANIZED CLUSTERS COMING OUT OF OF WV AHEAD OF
FRONT. WITH PWATS INCREASES THERE IS THE POTENTIAL FOR HEAVY RAINS.
MAIN THREAT DURING THE DAY WOULD MAINLY BE IN THE WEST. PLAYED HIGH
TEMPERATURES NEAR COOLER GUIDANCE WITH HIGHS FROM THE UPPER 70S IN
THE MOUNTAINS TO AROUND 90 IN THE SOUTHEAST.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 345 PM EDT SATURDAY...
COLD FRONT NOT TO ARRIVE UNTIL SUNDAY NIGHT...AND IT MAY BE THAT
BEST CHANCE FOR ORGANIZED CONVECTION...INCLUDING SLIGHT CHC OF
SEVERE AND HEAVIEST RAINFALL RATES...DO NOT ARRIVE UNTIL THE
EVENING. WITH SLOWER TIMING THE SEVERE POTENTIAL MAY BE LIMITED TO
EXTREME WESTERN PORTIONS OF AREA IF IT COMES IN LATE ENOUGH IN
EVENING...BUT HEAVY RAIN IS LOOKING LIKE A BIGGER CONCERN NOW UP
UNTIL AT LEAST MIDNIGHT. CONTEMPLATED FLASH FLOOD WATCH FOR THIS
PERIOD BUT WOULD NOT BE FOR MORE THAN ABOUT 6 HRS AS ANY HIGH RAINFALL
RATES DISSIPATE THROUGHOUT THE EVENING...AND PROBABLY LIMITED TO FAR
WESTERN PORTIONS...WV COUNTIES AND TAZEWELL MAINLY. SOME OF THESE
LOCATIONS HAVE HAD SIGNIFICANT RAINFALL RECENTLY BUT IT`S BEEN HIT
AND MISS. SO FOR NOW DECIDED TO HOLD OFF TO SEE IF FURTHER
GUIDANCE SUGGESTS EITHER AN EARLIER START OR LONGER THREAT TIME
INTO THE OVERNIGHT. INCREASES POPS SUNDAY NIGHT TO LIKELY AND
CATEGORICAL IN WEST.
MILDER OVERNIGHT LOWS MONDAY MORNING WITH EXTENSIVE CLOUD COVER
AND LINGERING PRECIP...AND ALSO COOLER HIGHS MONDAY UNDER SIMILAR
CONDITIONS AS FRONT SLOWLY MOVES ACROSS AREA. WENT SLIGHTLY COOLER
THAN LOWEST GUIDANCE NUMBERS. NOT SURE HOW MUCH INSTABILITY WILL
BE REALIZED FOR CONVECTION...SO MAINLY SHOWERS WITH ONLY SLIGHT
CHC FIRST HALF OF DAY...AND WITH LIKELY POPS ACROSS THE SOUTH BY
LATE IN THE DAY...STILL DOWNPLAYED THUNDER WITH ONLY A CHANCE. BETTER
TSTORM COVERAGE MAY BE WELL SOUTH OF OUR AREA.
BY TUESDAY SOME DIFFERENCES BETWEEN NAM AND GFS ARE EVIDENT...WITH
NAM TAKEING FRONTAL BOUNDARY FARTHER SOUTH...AND GFS WASHING IT
OUT ALLOWING BETTER SOUTHERLY FLOW TO RETURN. NAM HAS MID LEVEL
DRY AIR AND SUBSIDENCE ACROSS THE NORTHERN HALF OF FCST
AREA...SUPRESSING MOST CONVECTIVE THREATS DESPITE MODEST
INSTABILITY...WHEREAS GFS REMAINS MOIST AND HINTS AT WEAK UPPER
WAVE RIDING FROM SW TO NE HELPING TO SPREAD PRECIP BACK TO THE
NORTH AGAIN. COMPROMISED BETWEEN THE TWO BUT WITH A LEAN TOWARD
GFS...WITH SLIGHT CHC POPS ACROSS FAR NORTH BUT LIKELY ACROSS THE
SOUTH. INCREASED CLOUD COVER AND LOWERED HIGHS A BUT AS WELL GIVEN
FAVORED GFS SOLUTION...AGAIN GOING SLIGHTLY COOLER THAN LOWEST
GUIDANCE. THIS HAS SOME BUST POTENTIAL IF NAM IS CORRECT AND
PRECIP STAYS WELL SOUTH AND SOME CLEARING TAKES PLACE FARTHER
NORTH.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 1245 PM EDT SATURDAY...
DURING THE MID TO LATE PORTION OF THE WEEK...THE FRONTAL BOUNDARY IS
EXPECTED TO STALL ALONG THE SOUTHERN PERIPHERY OF THE FORECAST
AREA...IN RESPONSE TO A SLOWLY DIGGING UPPER LEVEL TROUGH OVER THE
SOUTHERN GREAT LAKES REGION. THE CONSENSUS OF GUIDANCE IS NOT
INDICATING THIS BOUNDARY WILL REMAIN CLOSE ENOUGH TO THE REGION TO
CONTINUE TO PROVIDE A FOCUSING MECHANISM FOR DAILY
CONVECTION...AIDED BY SOME WEAK UPPER LEVEL WAVES MOVING FROM
SOUTHWEST TO NORTHEAST. GENERALLY DURING THE WED/THURS TIME FRAME
THE PRECIP CHANCES WILL BE A LITTLE GREATER ACROSS THE SOUTHEAST
CLOSER TO THE WEAKENING FRONTAL BOUNDARY...BUT AM CONTINUING WITH
LOW TO MID CHANCE POPS FOR ALL LOCATIONS...EXCEPT FOR DIURNAL DROP
TO SLIGHT CHC OVERNIGHT. THEN...AS THE UPPER TROUGH DEEPENS TOWARD
THE END OF THE WEEK...A SECOND WEAK FRONTAL BOUNDARY WILL APPROACH
FROM THE NORTH LATE FRIDAY OR EARLY SATURDAY...INCREASING THE
CHANCES AGAIN FROM THE WEST. SOME MODELS ARE DEEPER WITH THIS TROUGH
THAN OTHERS...AND SUGGEST A BETTER POSSIBILITY THAT THE FRONT WILL
PUSH FARTHER THROUGH THE REGION BY LATE NEXT SATURDAY WITH POTENTIAL
FOR SOME DRYING AND SLIGHTLY COOLER TEMPS. ONLY HEDGING SLIGHTLY
TOWARD THIS IDEA SINCE THE CONSENSUS IN ENSEMBLES IS FOR A WEAKER
TROUGH AND LIFTING NORTHEAST BY NEXT WEEKEND...SO STILL SOME
UNCERTAINTY AS TO WHETHER THIS FRONT WILL REALLY PUSH THROUGH ANY
FARTHER THAN THE ONE FOR EARLIER IN THE WEEK.
WITH FRONTAL BOUNDARY LINGERING THROUGH MID WEEK JUST TO OUR
SOUTH...LOOKS LIKE INSTABILITY MAY BE LIMITED WITH PLENTY OF CLOUD
COVER EXPECTED...SO SEVERE POTENTIAL NOT ESPECIALLY HIGH...BUT
RELATIVELY HIGH MOISTURE CONTENT WITH WEAK CONVERGENCE ALONG OLD
BOUNDARY SUGGESTS A BIT MORE OF A FLASH FLOOD POTENTIAL ALTHOUGH
THIS STILL MUCH DEPENDENT ON GETTING HIGHER RAINFALL RATES.
INCREASED THE CLOUD COVER AND LOWERED HIGH TEMPS SOMEWHAT FROM
PREVIOUS FORECAST FOR WED AND THURS...BUT STILL GOING CLOSE TO
GFS-BASED GUIDANCE. SLIGHT WARMING BY FRIDAY AHEAD OF NEXT FRONTAL
BOUNDARY BUT STILL BORDERLINE IF THERE WILL BE ANY 90S ACROSS THE
PIEDMONT.
TROPICAL ACTIVITY TO MONITOR WITH ERNESTO MOVING TOWARD YUCATAN AND
INTO GULF BY MID WEEK BUT CURRENTLY EXPECTED TO REMAIN WELL SOUTH
AND NOT INFLUENCE THE MID ATLANTIC REGION. A TROPICAL WAVE CURRENTLY
OVER FLORIDA MAY EVENTUALLY EJECT SOME MOISTURE INTO OLD FRONTAL
BOUNDARY TO OUR SOUTH...AND COULD HELP ENHANCE SOME OF THE PRECIP
POTENTIAL BY MID WEEK. TROPICAL STORM FLORENCE WELL OUT IN THE
ATLANTIC LIKELY TO REMAIN WELL AWAY FROM MAINLAND BEFORE WEAKENING.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 1215 PM EDT SATURDAY...
LOW CLOUDS AND CONVECTION WILL HINDER AVIATION OPERATIONS
THIS AFTERNOON INTO TONIGHT. ATMOSPHERE REMAINS VERY MOIST...WITH
UPPER VORT REMAINING ALONG THE APPALACHIANS THIS AFTERNOON.
SCATTERED MVFR SHOWERS AND THUNDERSTORMS EXPECTED THIS AFTERNOON
INTO TONIGHT...KEPT VCTS AT TAF SITES UNTIL SUNSET. BELIEVE
THAT BCB AND DAN TAF SITES HAS THE BEST CHANCE OF A THUNDERSTORM.
DAN IS LOCATED BY THE RICHEST MOISTURE COMBINED WITH BEST INSTABILITY
CREATED BY SOLAR HEATING. ANY THUNDERSTORMS THIS AFTERNOON WILL BE
SLOW MOVING AND COULD CONTAIN HEAVY DOWNPOURS. EXPECT AREAS OF FOG
TO DEVELOP OVERNIGHT ESPECIALLY WHERE THUNDERSTORMS OCCUR THIS
AFTERNOON INTO THIS EVENING.
DEEPER MOISTURE REMAINS INTO EARLY NEXT WEEK WITH GREATER COVERAGE OF
SHOWERS AND STORMS...ESPCLY DURING THE AFTERNOON AND EVENING EACH
DAY THROUGH MONDAY. LOCAL MVFR/IFR CONDITIONS WILL BE ASSOCIATED
WITH THE MORE ORGANIZED STORMS. OUTSIDE OF THIS MAINLY DIURNALLY
DRIVEN CONVECTION...THE ONLY OTHER FLIGHT WEATHER HAZARDS WOULD BE
FROM OVERNIGHT VALLEY FOG.
A COLD FRONT IS EXPECTED TO DROP SOUTHEAST OUT OF THE OHIO VALLEY
MONDAY...CROSSING THE MID ATLANTIC REGION. WITH THE PASSAGE OF
THIS FRONT...WINDS SHOULD BECOME NORTHERLY...WITH A DAY OR TWO OF
DRY WEATHER AND VFR CONDITIONS FOLLOWING THE FRONTAL PASSAGE FOR
MID WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...KK
SHORT TERM...SK
LONG TERM...SK
AVIATION...KK/PM
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
258 PM CDT SAT AUG 4 2012
.SHORT TERM...TODAY THROUGH SUNDAY.
STORMS FIRED ALONG BOUNDARY IN MANITOWOC AND WAUPACA COUNTIES THIS
AFTN...AS THE MORNING RUNS OF THE HRRR MODEL INDICATED. CORRIDOR
OF HIGH INSTABILITY FROM S WI INTO THE FAR E PART OF THE STATE AND
CONVERGENCE ALONG BOUNDARIES ENOUGH TO INITIATE DEEP CONVECTION.
MAIN LINE OF SHOWERS AND STORMS...HOWEVER...MOVING INTO THE WEST
PART OF FORECAST AREA. THIS WILL MOVE ACROSS THE AREA LATE THIS
AFTERNOON AND EARLY EVENING PER LATEST RUN OF HRRR. BEST CHANCE OF
SEVERE WILL BE SOUTH OF FORECAST AREA...BUT STILL A THREAT IN THE
EAST-CENTRAL IN UNSTABLE AIRMASS AND INTERACTION OF LOW-LEVEL
BOUNDARIES.
UPPER TROF WILL QUICKLY SWING THROUGH TONIGHT. SMALL CHANCE FOR
LINGERING SHOWERS BEHIND MAIN LINE LATER THIS EVENING.
OTHERWISE...CLEARING SKIES ACROSS MUCH OF AREA. EXCEPTION IS IN THE
FAR NORTH CLOSER TO THE UPPER LOW AND RESIDUAL MOISTURE.
TEMPS TONIGHT AND SUNDAY ARE A BLEND OF MODELS...CLOSE TO
PREVIOUS FORECAST.
.LONG TERM...SUNDAY NIGHT THROUGH NEXT FRIDAY.
MEAN LONGWAVE PATTERN FOR THE EXTENDED FORECAST PERIOD GENERALLY
CHARACTERIZED BY A TROUGH OVER THE OHIO VALLEY AND RIDGE OVER THE
INTERMOUNTAIN WEST. WESTERN GREAT LAKES REGION WILL RESIDE IN
NORTHWESTERLY FLOW REGIME WITH AN OCCASIONAL EMBEDDED SHORTWAVE
DISTURBANCES TRAVERSING THE AREA. TIMING AND INTENSITY OF EMBEDDED
SHORTWAVE DISTURBANCES WITHIN THIS FLOW REGIME ARE TYPICALLY
PROBLEMATIC...THUS FORECAST CONFIDENCE IN THIS REGARD IS LOW TO
MEDIUM. EARLY IN THE WORK WEEK... DAYTIME TEMPERATURES WILL START
OUT ABOVE NORMAL...THEN SLOWLY FALL BACK TO NEAR...OR PERHAPS
SLIGHTLY BELOW NORMAL FOR EARLY AUGUST.
SURFACE HIGH PRESSURE WILL CONTINUE TO BUILD EASTWARD ACROSS THE
FORECAST AREA SUNDAY NIGHT INTO MONDAY. WENT ON THE COOLER SIDE
SIDE OF AVAILABLE GUIDANCE WITH RESPECT TO MIN TEMPERATURES SUNDAY
NIGHT GIVEN CLEAR SKIES...LIGHT WINDS AND RATHER DRY DRY AIRMASS.
MONDAY LOOKS LIKE A PLEASANT DAY WITH SUNNY SKIES...RELATIVELY
LIGHT WINDS WITH DAYTIME HIGHS A FEW DEGREES ABOVE NORMAL.
SHORTWAVE DISTURBANCE THEN FORECAST TO HEAD SOUTHEAST ACROSS
SOUTHERN HUDSON BAY MONDAY NIGHT INTO EARLY TUESDAY. ASSOCIATED
COLD FRONT WILL GET SHOVED SOUTHEAST TOWARD NORTHWEST WISCONSIN BY
AROUND 06Z TUESDAY. APPEARS TO BE A PLUME OF HIGHER MID-LEVEL
LAPSE RATES AND MODEST 850 WAA OUT AHEAD OF THIS SYSTEM. HOWEVER
AVAILABLE MOISTURE IS SOMEWHAT LIMITED. THUS...HAVE MAINLY SMALL
CHANCE POPS OVER NORTHWEST COUNTIES OVERNIGHT...THEN CARRY THESE
SMALL POPS SOUTHEAST ACROSS THE AREA TUESDAY MORNING. MAJORITY OF
GUIDANCE SUGGEST THAT FRONT WILL PASS SOUTHEAST OF THE FORECAST
AREA BY ABOUT 18Z TUESDAY WITH CAA TO ENSUE DURING THE AFTERNOON.
WEAK HIGH PRESSURE RETURNS TO THE AREA TUESDAY NIGHT INTO EARLY
WEDNESDAY...WITH NEXT DISTURBANCE ALREADY APPROACHING THE NORTHERN
MISSISSIPPI VALLEY BY WEDNESDAY MORNING. MODEL CONSENSUS SUGGESTS
THIS SYSTEM WILL BE A BIT MORE POTENT AS IT TRAVERSES SOUTHEAST
ACROSS THE FORECAST AREA THURSDAY. OPERATIONAL GFS AND ECMWF ARE A
BIT FURTHER SOUTH WITH STRENGTHENING SURFACE LOW WHILE GEM A BIT
FURTHER NORTH. BOTTOM LINE IS THAT IT LOOKS LIKE THERE WILL BE A
PRETTY DECENT CHANCE FOR SHOWERS AND THUNDERSTORMS DURING THE DAY ON
THURSDAY. BUMPED UP POPS FROM PREVIOUS FORECAST. SOME MODEL
DIFFERENCES ON EVOLUTION OF UPPER TROUGH AND ASSOCIATED SURFACE LOW
THURSDAY NIGHT INTO FRIDAY. SYSTEM DOES APPEARS TO SLOW DOWN
SOMEWHAT AS IT DEEPENS JUST TO THE EAST OF THE FORECAST AREA...THUS
PRECIPITATION COULD VERY WELL LINGER INTO FRIDAY ESPECIALLY OVER THE
EASTERN HALF OF THE FORECAST AREA. CLOUDS...SCATTERED PRECIPITATION
AND NORTHEASTERLY BOUNDARY LAYER FLOW ON FRIDAY WILL LIKELY HOLD
TEMPERATURES MAINLY IN THE 70S.
&&
.AVIATION...LINE OF STORMS FORECAST TO ENTER WESTERN PART OF
FORECAST AREA BY 18Z...THEN MOVE EAST THROUGH AREA BY 00Z. IFR
CONDITIONS CAN BE EXPECTED WITH STRONGER STORMS. WIND GUSTS OVER
40 KTS POSSIBLE WITH STORMS AT AIRPORTS IN CENTRAL AND EAST-
CENTRAL WI. BEST CHANCE FOR SEVERE WILL BE OVER SOUTHERN PART OF
STATE.
JKL
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JKL/ESB
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1225 PM CDT SAT AUG 4 2012
.SHORT TERM...THROUGH MONDAY
246 AM CDT SAT AUG 4 2012
MAIN FORECAST CONCERN IS WITH THE RAIN CHANCES TODAY.
SURFACE ANALYSIS THIS MORNING SHOWS AN AREA OF LOW PRESSURE OVER
SOUTHEAST SASKATCHEWAN WITH A COLD FRONT EXTENDING SOUTH INTO
EASTERN NEBRASKA. LOCAL AND REGIONAL RADARS SHOWING A LINE OF
CONVECTION OUT AHEAD OF THE FRONT FROM NORTHWEST WISCONSIN INTO
NORTHERN IOWA.
ONGOING CONVECTION WAS FUELED BY A SHORT WAVE TROUGH THAT EJECTED
OUT AHEAD OF THE MAIN LONG WAVE TROUGH AND BY LOW LEVEL WARM AIR
ADVECTION AHEAD OF THE WAVE. ACTIVITY HAS BEEN SLOWLY WEAKENING AS
IT MOVES EAST AS VWP WIND PROFILES SHOWS JUST A WEAK MOISTURE
TRANSPORT SIGNAL OUT AHEAD OF THE LINE ALONG WITH LESS INSTABILITY
TO THE EAST. THE 03.12Z AND 04.00Z HI-RES ARW HANDLED THIS SYSTEM
EXTREMELY WELL AND SUGGESTS IT WILL CONTINUE TO DIMINISH BUT HOLD
TOGETHER AS IT MOVES ACROSS THE FORECAST AREA...EXITING TO THE
EAST BEFORE 12Z. ANOTHER AREA OF CONVECTION OVER SOUTHWEST
MINNESOTA INTO NEBRASKA IS IN A MORE FAVORABLE POSITION TO
MAINTAIN ITSELF THROUGH THE NIGHT. THERE IS A BETTER LOW LEVEL JET
FEEDING INTO THIS AIDING THE ISENTROPIC UP GLIDE. AGAIN...THE HI-
RES ARW HAS A GOOD HANDLE ON THIS AS DOES THE 04.08Z HRRR WHICH
BRINGS THIS ACTIVITY INTO THE FORECAST AREA BEFORE IT DISSIPATES
BY MID MORNING AS THE LOW LEVEL JET DECREASES AFTER SUNRISE. HAVE
ACCOUNTED FOR THIS TREND WITH A BAND OF 60 PERCENT CHANCES FROM
SOUTHWEST TO NORTHEAST THROUGH 15Z AND THEN BACKED DOWN TO A 30 TO
40 PERCENT CHANCE FOR THE REMAINDER OF THE MORNING.
ATTENTION FOR THE AFTERNOON THEN TURNS TO THE LONG WAVE TROUGH TO
THE WEST. THIS IS EXPECTED TO CONTINUE LIFTING NORTHEAST THROUGH
THE DAY WITH THE UPPER LEVEL LOW GOING INTO WESTERN ONTARIO BY
LATE AFTERNOON. THE LATEST SET OF MODELS NOW SUGGEST THE TROUGH
AXIS WILL REMAIN POSITIVELY TILTED THROUGH THE DAY AND NOT TAKE ON
MORE OF A NEUTRAL TILT UNTIL TONIGHT ONCE IT IS EAST OF THE AREA.
THIS IS EXPECTED TO RESULT IN ABOUT 8 PVU/S OF VORTICITY ADVECTION
IN THE 500-300 MB LAYER COMING ACROSS THIS AFTERNOON WITH AN
INCREASE TONIGHT ONCE IT IS TO THE EAST OF THE AREA. IN THE LOW
LEVELS...THE FRONT SHOULD COME THROUGH WITH WEAK TO MODERATE
FRONTOGENESIS IN THE 1000-700 MB LAYER ALONG WITH UP TO 2 UBAR/S
OF UP GLIDE ON THE 310K ISENTROPIC SURFACE. THIS FORCING WILL ALSO
BE AIDED BY PRETTY GOOD DIVERGENCE ALOFT AS THE AREA WILL BE UNDER
THE RIGHT ENTRANCE REGION OF THE 100+ JET CORE AT 300 MB. THIS
FORCING IS EXPECTED TO BE ENOUGH TO GENERATE ANOTHER LINE OF
CONVECTION ALONG THE FRONT THIS AFTERNOON WITH THE BEST CHANCES
FOR REDEVELOPMENT OVER THE EASTERN PORTIONS OF THE FORECAST AREA.
WITH THE TIMING OF THE FRONT...THERE JUST MAY NOT BE ENOUGH TIME
FOR RECOVERY TO OCCUR OVER THE WEST FOR MUCH TO DEVELOP.
SEVERAL OF THE MODELS SUGGEST THE POTENTIAL FOR A NARROW CORRIDOR
OF UPPER 60S TO AROUND 70 DEW POINTS ALONG THE FRONT WHICH COULD
LEAD TO ML CAPES OF 2500 J/KG. THE BEST 0-6KM SHEAR DOES NOT LOOK
LIKE IT WILL CATCH UP WITH THE INSTABILITY BECAUSE OF THE POSITIVE
TILT OF THE LONG WAVE TROUGH...BUT UP TO 30 KNOTS OF 0-3KM SHEAR
SHOULD RESIDE OVER THE INSTABILITY AXIS. THIS WILL PROVIDE ENOUGH
SHEAR TO HELP ORGANIZE THE EXPECTED DEVELOPMENT ALONG THE FRONT
ALONG WITH POSSIBLY SUPPORTING SOME SEVERE STORMS. THE 04.00Z NAM
SUGGEST THERE WILL BE BETWEEN 1250-1500 J/KG OF DCAPE AVAILABLE
ALONG WITH FAVORABLE TEMPS ALOFT FOR SOME HAIL PRODUCTION AS
HEIGHTS LOWER WITH THE APPROACHING LONG WAVE TROUGH. SO IF THE
STORMS DO BECOME SEVERE...DAMAGING WINDS AND LARGE HAIL WILL BE
THE MAIN THREATS. HAVE LEFT THE RAIN CHANCES AT 60 PERCENT FOR THE
AFTERNOON AS SOME CONCERN ON HOW FAST THE CLOUDS FOR THIS
MORNING/S CONVECTION WILL CLEAR OUT. IF THESE HOLD ON LONGER THAN
EXPECTED...THE INSTABILITY WILL NOT BUILD SETTING UP THE POTENTIAL
FOR LESS CONVECTION TO OCCUR.
ONCE THIS SYSTEM GOES THROUGH...A NORTHWEST FLOW ALOFT WILL BE IN
PLACE OVER THE UPPER MIDWEST. THE NAM AND 03.12Z ECMWF ARE
SUGGESTING A SHORT WAVE TROUGH IN THIS FLOW WILL COME ACROSS
MONDAY NIGHT PUSHING A WEAK COLD FRONT THROUGH THE AREA. THIS
FRONT LOOKS TO HAVE PRETTY DECENT FRONTOGENESIS WITH IT AND WILL
CARRY A SMALL RAIN CHANCE ACROSS MUCH OF THE AREA.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY
246 AM CDT SAT AUG 4 2012
THE NORTHWEST FLOW ALOFT WILL CONTINUE THROUGH THE PERIOD WITH THE
NEXT SHORT WAVE TROUGH EXPECTED TO PASS OVER WEDNESDAY NIGHT AND
THURSDAY. THIS SHOULD PUSH ANOTHER WEAK COLD FRONT THROUGH FOR A
SMALL CHANCE OF RAIN. THE 04.00Z ECMWF SUGGESTS THIS SHORT WAVE
TROUGH WILL THEN BE FOLLOWED BY AN UPPER LEVEL LOW DROPPING DOWN
FROM THE HUDSONS BAY AREA. AS THIS MOVES ACROSS THE GREAT LAKES
REGION SOME RAIN CHANCES WILL LINGER INTO THURSDAY NIGHT AND FRIDAY.
&&
.AVIATION...THIS AFTERNOON THROUGH SUNDAY
1225 PM CDT SAT AUG 4 2012
LINE OF MVFR/IFR SHRA/TSRA WILL BE EXITING EAST OF KLSE BY 19Z WITH
ONLY LINGERING -SHRA THRU 20Z. SMALL AREA OF POST-FRONTAL STRATO-CU
IN THE 2500 TO 3500 FT RANGE WILL ROTATE ACROSS THE TAF SITES THRU
ABOUT 21Z...BUT BE PROGRESSIVE WITH DECREASING CLOUDS/CLEARING SKIES
FOR THE LATE AFTERNOON/EVENING HOURS AS A DRIER/COOLER AIRMASS AND
SUBSIDENCE SPREAD ACROSS THE AREA. OF CONCERN IS THE MVFR CLOUD
SHIELD OVER MUCH OF ND/NORTHERN MN...WRAPPED AROUND/BEHIND THE
SFC-850BM LOW. INCREASING NORTHWEST FLOW BEHIND THE DEPARTING
LOW/COLD FRONT WILL ADVECT THIS MOISTURE/CLOUDS SOUTHEAST TONIGHT.
ADDED A PERIOD OF 2500-3000FT CLOUDS/CIGS TO BOTH KRST/LSE FOR THE
LATE EVENING/OVERNIGHT HOURS AS THIS MOISTURE ROTATES ACROSS THE
AREA. DRIER HIGH PRESSURE/ANTI-CYCLONIC FLOW BUILDS INTO THE AREA
FOR SUN. WITH DIURNAL WARMING/MIXING GOOD VFR EXPECTED SUNDAY WITH
ONLY SCT VFR CUMULUS..AND CLOUD BASES RISING THRU THE DAY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
246 AM CDT SAT AUG 4 2012
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....RRS