Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/12/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
942 AM MST MON AUG 10 2015
.SYNOPSIS...
SOUTHERLY FLOW ALOFT WILL GRADUALLY INCREASE MOISTURE
LEVELS ACROSS THE REGION TODAY THROUGH TUESDAY...WITH TUESDAY
AFTERNOON AND EVENING SEEING THE BEST CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS SOUTH CENTRAL ARIZONA. VERY STRONG HIGH
PRESSURE ALOFT BUILDING INTO THE REGION FROM THE EAST WILL THEN
BRING MUCH ABOVE NORMAL TEMPERATURES AND REDUCE THUNDERSTORM CHANCES
FROM WEDNESDAY ONWARD INTO SATURDAY...WITH COOLER TEMPERATURES AND
BETTER CHANCES FOR STORMS RETURNING FROM SUNDAY ONWARD INTO EARLY
NEXT WEEK.
&&
.DISCUSSION...
DEBRIS CLOUDINESS PERSISTS THIS MORNING ACROSS EAST-CENTRAL AZ BUT IS
SHOWING SIGNS OF BREAKING APART. HIGH-RES WRFS ARE EXHIBITING
SOMEWHAT MORE VARIABILITY THIS MORNING IN THE PLACEMENT OF THE
AFTERNOON CONVECTION...THOUGH THE CONSENSUS IS THAT ACTIVITY WILL BE
MOST LIKELY FROM PHOENIX EASTWARD. LATEST RUNS OF THE HRRR INDICATE
THAT THE MORNING CLOUDS WILL INHIBIT CONVECTION...SUGGESTING ONLY
ISOLATED STORMS LATE THIS AFTERNOON...MAINLY ACROSS NORTHERN GILA
COUNTY.
SHORT-TERM UPDATES TO THE FORECAST ARE NEEDED THIS MORNING...MAINLY
TO ACCOUNT FOR THE DELAYED RISE IN TEMPERATURES. OTHERWISE...THE
FORECAST REMAINS ON TRACK.
&&
.PREVIOUS DISCUSSION...
IT NOW APPEARS THAT TUESDAY WILL LIKELY BE THE MOST ACTIVE DAY...AS
THE FLOW ALOFT BECOMES SOUTHERLY THROUGH THE WHOLE COLUMN WITH LESS
CLOUDINESS LIKELY ON TUESDAY MORNING THEN WHAT WE ARE SEEING
TODAY...WITH SOME DECENT MID-LEVEL SHEAR PERHAPS ENHANCING THE
THUNDERSTORM INTENSIFY/COVERAGE...AND AT LEAST SOME STORM ACTIVITY
WORKING ITS WAY INTO SW AZ.
WEDNESDAY THROUGH SATURDAY...
IT NOW LOOKS INCREASINGLY LIKELY THAT WE WILL SEE SOME VERY HOT
TEMPERATURES DURING THIS PERIOD AS THE MAIN LONG-WAVE PATTERN RE-
ADJUSTS ITSELF OVER NORTH AMERICA...WITH RATHER DEEP TROFING DROPPING
DOWN INTO THE GREAT LAKES/NE US...AND THE MAIN UPPER RIDGE AXIS BEING
FORCED WESTWARD OVER THE DESERT SW. EVEN THOUGH OUR MID/UPPER-LEVEL
FLOW IS EXPECTED TO REMAIN MAINLY FROM A SE-LY DIRECTION DURING THIS
PERIOD...WHICH NORMALLY IS THE BEST DIRECTION FOR MONSOON MOISTURE TO
BE IMPORTED INTO THE REGION...THE UPPER HIGH CENTER THAT IS FORECAST
TO BUILD OVER OUR REGION IS EXPECTED TO BE QUITE STRONG...WITH 500MB
HEIGHTS RISING INTO THE 596-598DM RANGE BY THU-FRI. THIS UPPER HIGH
CENTER...WHICH HAS BEEN CENTERED OVER THE GULF COAST REGION THE LAST
FEW DAYS...HAS BROUGHT THAT REGION VERY HOT AND DRY CONDITIONS...WITH
HIGHS APPROACHING OR EXCEEDING 100 DEGREES AT MANY
LOCATIONS...INCLUDING HOUSTON AND NEW ORLEANS. STRONG SUBSIDENCE
ALOFT HAS COMPLETELY SHUT DOWN THE CONVECTION THAT NORMALLY KEEPS
HIGHS DOWN IN THE LOW-MID 90S AT THESE COASTAL LOCATIONS...AND IT
APPEARS THAT THIS SUBSIDENCE IS HEADED OUR WAY...AS INDICATED ON THE
LATEST FORECAST SOUNDINGS. THUS...IT APPEARS THAT THUNDERSTORM
ACTIVITY WILL BE NOTICEABLY REDUCED DURING THIS PERIOD...WITH MOST
ACTIVITY BEING CONFINED TO THE HIGHER TERRAIN OF SOUTH-CENTRAL AND SW
AZ. THIS LACK OF CONVECTIVE ACTIVITY/INCREASED SUNSHINE ALONG WITH
VERY WARM AIR ALOFT (500MB TEMPS IN THE -3C TO -4C RANGE) IS ALSO
EXPECTED TO ALLOW OUT TEMPERATURES TO RISE WELL ABOVE NORMAL...WITH
WIDESPREAD READINGS IN THE 110-115F RANGE ACROSS THE LOWER DESERTS.
THESE VERY HOT DAYS ALONG WITH NIGHTTIME LOWS NEAR 90 AT THE WARMER
URBAN LOCATIONS MAKES THE ISSUANCE OF HEAT PRODUCTS LATER THIS WEEK
VERY LIKELY...ESPECIALLY FOR THE THU-FRI TIME PERIOD.
SUNDAY AND MONDAY...
ALTHOUGH SOME MODEL DISAGREEMENT DOES CROP UP DURING THIS
PERIOD...IT APPEARS LIKELY THAT THE RIDGING OVER THE DESERT SOUTHWEST
WILL BEGIN TO WEAKEN...WITH COOLER TEMPERATURES AND A BETTER CHANCE
FOR THUNDERSTORMS RETURNING TO THE REGION.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A REMNANT CIRCULATION CENTER NEAR TUCSON WILL ROTATE THROUGH THE
PHOENIX AREA THIS MORNING. AT THIS POINT IT APPEARS THE ONLY IMPACT
WILL BE INCREASED MID LEVEL CLOUDS AND POSSIBLY A FEW SPRINKLES...BUT
THAT`S ABOUT IT. LOOKING AHEAD TO THIS AFTERNOON...STORMS ARE
POSSIBLE SOUTH/EAST OF PHOENIX BUT ARE EXPECTED TO DISSIPATE BEFORE
REACHING ANY OF THE PHOENIX TERMINALS. MOST LIKELY IMPACT WOULD BE A
MID EVENING SOUTHEASTERLY OUTFLOW SOME TIME BETWEEN 03Z-06Z. WILL
LEAVE ALL OTHER WEATHER OUT OF THE TAFS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
DISTANT HIGH CLOUDS SHOULD BE THE ONLY IMPACT AT BOTH SE CA SITES.
WINDS SHOULD BE LIGHT /CAN`T RULE OUT AN OCCASIONAL LATE DAY GUST/ AND
FOLLOW DIURNAL TENDENCIES.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
MONSOON MOISTURE WILL LINGER OVER THE REGION WEDNESDAY BEFORE SOME
DRIER AIR BEGINS TO ADVECT INTO THE AREA. SLIGHT CHANCES FOR STORMS
WILL CONTINUE...BEFORE TAPERING OFF HEADING THROUGH THE LATE WEEK
AND INTO THE EARLY WEEKEND. AS HUMIDITIES AND DEWPOINTS BEGIN TO
SLOWLY DROP...TEMPERATURES WILL BEGIN TO WARM AND HEADING ABOVE
SEASONAL NORMALS FOR THE END OF THE WEEK. WINDS WILL GENERALLY BE
LIGHT THROUGH THE MAJORITY OF THE FORECAST PERIOD WITH
PERIODS OF UPSLOPE AFTERNOON GUSTINESS.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT CONDITIONS ACCORDING TO STANDARD
OPERATING PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...LEINS
FIRE WEATHER...NOLTE
AREA FORECAST DISCUSSION
NWS RENO NV
541 AM PDT MON AUG 10 2015
.UPDATE...
WE HAVE SEEN A FEW LIGHTNING STRIKES WITH THE WAVE LIFTING NORTH
ACROSS NE CA AND FAR NW NV THIS MORNING. AS THIS WAVES MOVES NORTH
THE TSTM/SHOWER ACTIVITY SHOULD END FROM SOUTH TO NORTH. WILL MAKE
SOME MINOR ADJUSTMENTS TO TIMING OF THE WEATHER THIS MORNING TO
ACCOUNT FOR THIS DECREASE FROM SOUTH TO NORTH. OTHERWISE NO
CHANGES TO THE CURRENT FORECAST. 20
&&
.PREVIOUS DISCUSSION... /ISSUED 230 AM PDT MON AUG 10 2015/
SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE THROUGH THIS MORNING WITH A SLIGHT
CHANCE OF THUNDERSTORMS NORTH OF INTERSTATE 80. SOUTH FLOW THEN
RESUMES MONDAY AFTERNOON AS LOW PRESSURE DROPS OFF THE WEST
COAST. DRY CONDITIONS WITH TYPICAL AFTERNOON BREEZES AND NEAR
NORMAL TEMPERATURES ARE EXPECTED. WINDY CONDITIONS ARE POSSIBLE
THURSDAY AS THE LOW MOVES INTO OREGON.
SHORT TERM...
WATER VAPOR AND IR SATELLITE IMAGERY SHOW A DEFINED UPPER LEVEL
DISTURBANCE MOVING INTO THE CALIFORNIA INTERIOR THIS MORNING. AS A
RESULT, ISOLATED VIRGA SHOWERS HAVE FORMED NORTH OF THE TAHOE
BASIN NORTHWARD INTO NORTHERN LASSEN COUNTY. THE HRRR AND NAM
CONCUR THAT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
THROUGH MID MORNING TODAY AS THIS WAVE MOVES NORTHWARD. ANY
THUNDERSTORMS THAT DO RESULT WILL BE DRY WITH DRY LIGHTNING THE
PRIMARY THREAT. NEW FIRE STARTS WILL BE POSSIBLE, BUT COVERAGE OF
CELLS DOES NOT WARRANT A RED FLAG WATCH OR WARNING.
AS FOR CONSIDERATIONS INVOLVING THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, HAVE EXTENDED AREAS OF SMOKE THROUGH MID
MORNING IN SOUTHERN MONO COUNTY WITH HAZE PERSISTING INTO THE
AFTERNOON. FIRE ACTIVITY THIS MORNING WILL DETERMINE WHETHER OR
NOT THESE CONDITIONS PERSIST INTO TUESDAY.
OTHERWISE, LOW PRESSURE DEEPENS AND DROPS SOUTH IN THE EASTERN
PACIFIC WITH HIGH PRESSURE LOCATED OVER THE WESTERN PLAINS OF THE
UNITED STATES. THIS LEAVES THE SIERRA AND WESTERN NEVADA IN A
NEUTRAL PRESSURE ADVECTION REGION RESULTING IN GENERALLY BENIGN
WEATHER CONDITIONS. MOISTURE TRANSPORT VECTORS ARE NOT FAVORABLE
FOR A MONSOONAL MOISTURE SURGE AT THIS TIME. THE MOST SIGNIFICANT
IMPACTS THROUGH MID WEEK WILL COME FROM DRIER SOUTH TO WESTERLY
FLOW EACH AFTERNOON WITH LOCALLY BREEZY CONDITIONS FROM TYPICAL
AFTERNOON ZEPHYRS. AS SEEN WITH THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, THESE WINDS AND DRY CONDITIONS COULD
ACTIVATE HOLDOVERS ALLOWING FOR RAPID FIRE GROWTH. BOYD
LONG TERM...THURSDAY THROUGH SUNDAY...
MEDIUM RANGE OPERATIONAL MODELS ARE IN GOOD AGREEMENT AGAIN THIS
CYCLE THROUGH EARLY SATURDAY. AFTER THAT DIFFERENCES APPEAR...AS
THEY HAVE BEEN DOING SO FOR THE PAST FEW DAYS. UPPER LOW MOVES INTO
THE PAC NW ON THURSDAY WITH STRONG LOW LEVEL PRESSURE AND THERMAL
GRADIENTS OVER THE NORTHERN PART OF THE FORECAST AREA NORTH INTO
OREGON. THESE STRONG GRADIENTS SHOULD DRIVE GUSTY WEST TO SOUTHWEST
WINDS OVER THE NORTHERN 2/3RDS OF THE FORECAST AREA THURSDAY
AFTERNOON AND EVENING. INCREASED MIXING WILL PUSH TEMPS AT OR ABOVE
AVERAGE FOR ALL BUT THE FAR NORTHERN FORECAST AREA AND HUMIDITY
VALUES SHOULD BE FAIRLY LOW. THIS COMBINATION WILL LIKELY PRODUCE
CRITICAL FIRE WEATHER CONDITIONS FOR AT LEAST THE AREA NORTH OF
HIGHWAY 50.
UPPER LOW MOVES EAST FRIDAY WITH A LESSENING OF THE GRADIENT AND
ATTENDANT WINDS. TEMPS WILL ALSO DECREASE OVER FAR NORTHERN AREAS OF
THE CWA. DRY SOUTHWEST FLOW WILL KEEP ANY MENTION OF PCPN OUT OF THE
FORECAST THROUGH AT LEAST SATURDAY. THE OPERATIONAL MODELS START TO
DIVERGE SATURDAY WITH THE GFS HOLDING ON TO THE TROUGH A BIT LONGER
WHILE THE ECMWF STARTS TO WEAKEN THE TROUGH AND BUILD A FLAT RIDGE.
BY SUNDAY THE ECMWF IS MORE AGGRESSIVE BUILDING THE RIDGE AND THE
GFS MAINTAINS A WEAK TROUGH. THE GEFS ENSEMBLE MEMBERS SHOW SOME
SUPPORT FOR BOTH SOLUTIONS SO A COMPROMISE WAS MADE. THIS MEANT
KEEPING THE HIGH TEMPS BELOW THE ECMWF GUIDANCE FOR SATURDAY AND
SUNDAY.
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST. IF THE ECMWF
SOLUTION IS MORE CORRECT THEN WE MIGHT SEE AND OUTSIDE CHANCE AT
WEAK CONVECTION OVER THE FAR SOUTHERN CWA BY SUNDAY AS LIGHT UPSLOPE
FLOW BRINGS A BIT MORE MOISTURE BACK TO THE REGION. OTHERWISE DRY
WITH NEAR SEASONAL TEMPERATURES FOR THE EXTENDED PERIOD AND TYPICAL
AFTERNOON WINDS ONCE WE GET PAST THURSDAY. 20
AVIATION...
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING
NORTH OF INTERSTATE 80 AS AN UPPER LEVEL WAVE OF LOW PRESSURE MOVES
NORTH. OUTSIDE OF THE WAVE THERE SHOULD BE VFR CONDITIONS TODAY.
TYPICAL SUMMER AFTERNOON WINDS ARE LIKELY TODAY WITH GUSTS EAST OF
THE SIERRA IN THE 20-25 KT RANGE.
HAZE AND SMOKE FROM CALIFORNIA FIRES WILL PRODUCE PERIODS OF
LOWERED VISIBILITY TODAY AND TUESDAY.
FAIRLY LIGHT WINDS TUESDAY. RIDGE WINDS BEGIN TO INCREASE WEDNESDAY
AND THEN GUSTY WINDS DEVELOP THURSDAY AHEAD OF A SURFACE BOUNDARY
THAT MOVES THROUGH THURSDAY NIGHT. INCREASED TURBULENCE IS HIGHLY
PROBABLE FROM LATE WEDNESDAY THROUGH THURSDAY. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS RENO NV
230 AM PDT MON AUG 10 2015
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE THROUGH THIS MORNING WITH A SLIGHT
CHANCE OF THUNDERSTORMS NORTH OF INTERSTATE 80. SOUTH FLOW THEN
RESUMES MONDAY AFTERNOON AS LOW PRESSURE DROPS OFF THE WEST
COAST. DRY CONDITIONS WITH TYPICAL AFTERNOON BREEZES AND NEAR
NORMAL TEMPERATURES ARE EXPECTED. WINDY CONDITIONS ARE POSSIBLE
THURSDAY AS THE LOW MOVES INTO OREGON.
&&
.SHORT TERM...
WATER VAPOR AND IR SATELLITE IMAGERY SHOW A DEFINED UPPER LEVEL
DISTURBANCE MOVING INTO THE CALIFORNIA INTERIOR THIS MORNING. AS A
RESULT, ISOLATED VIRGA SHOWERS HAVE FORMED NORTH OF THE TAHOE
BASIN NORTHWARD INTO NORTHERN LASSEN COUNTY. THE HRRR AND NAM
CONCUR THAT ISOLATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE
THROUGH MID MORNING TODAY AS THIS WAVE MOVES NORTHWARD. ANY
THUNDERSTORMS THAT DO RESULT WILL BE DRY WITH DRY LIGHTNING THE
PRIMARY THREAT. NEW FIRE STARTS WILL BE POSSIBLE, BUT COVERAGE OF
CELLS DOES NOT WARRANT A RED FLAG WATCH OR WARNING.
AS FOR CONSIDERATIONS INVOLVING THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, HAVE EXTENDED AREAS OF SMOKE THROUGH MID
MORNING IN SOUTHERN MONO COUNTY WITH HAZE PERSISTING INTO THE
AFTERNOON. FIRE ACTIVITY THIS MORNING WILL DETERMINE WHETHER OR
NOT THESE CONDITIONS PERSIST INTO TUESDAY.
OTHERWISE, LOW PRESSURE DEEPENS AND DROPS SOUTH IN THE EASTERN
PACIFIC WITH HIGH PRESSURE LOCATED OVER THE WESTERN PLAINS OF THE
UNITED STATES. THIS LEAVES THE SIERRA AND WESTERN NEVADA IN A
NEUTRAL PRESSURE ADVECTION REGION RESULTING IN GENERALLY BENIGN
WEATHER CONDITIONS. MOISTURE TRANSPORT VECTORS ARE NOT FAVORABLE
FOR A MONSOONAL MOISTURE SURGE AT THIS TIME. THE MOST SIGNIFICANT
IMPACTS THROUGH MID WEEK WILL COME FROM DRIER SOUTH TO WESTERLY
FLOW EACH AFTERNOON WITH LOCALLY BREEZY CONDITIONS FROM TYPICAL
AFTERNOON ZEPHYRS. AS SEEN WITH THE ROUGH FIRE IN THE SOUTHERN
SIERRA OF CALIFORNIA, THESE WINDS AND DRY CONDITIONS COULD
ACTIVATE HOLDOVERS ALLOWING FOR RAPID FIRE GROWTH. BOYD
.LONG TERM...THURSDAY THROUGH SUNDAY...
MEDIUM RANGE OPERATIONAL MODELS ARE IN GOOD AGREEMENT AGAIN THIS
CYCLE THROUGH EARLY SATURDAY. AFTER THAT DIFFERENCES APPEAR...AS
THEY HAVE BEEN DOING SO FOR THE PAST FEW DAYS. UPPER LOW MOVES INTO
THE PAC NW ON THURSDAY WITH STRONG LOW LEVEL PRESSURE AND THERMAL
GRADIENTS OVER THE NORTHERN PART OF THE FORECAST AREA NORTH INTO
OREGON. THESE STRONG GRADIENTS SHOULD DRIVE GUSTY WEST TO SOUTHWEST
WINDS OVER THE NORTHERN 2/3RDS OF THE FORECAST AREA THURSDAY
AFTERNOON AND EVENING. INCREASED MIXING WILL PUSH TEMPS AT OR ABOVE
AVERAGE FOR ALL BUT THE FAR NORTHERN FORECAST AREA AND HUMIDITY
VALUES SHOULD BE FAIRLY LOW. THIS COMBINATION WILL LIKELY PRODUCE
CRITICAL FIRE WEATHER CONDITIONS FOR AT LEAST THE AREA NORTH OF
HIGHWAY 50.
UPPER LOW MOVES EAST FRIDAY WITH A LESSENING OF THE GRADIENT AND
ATTENDANT WINDS. TEMPS WILL ALSO DECREASE OVER FAR NORTHERN AREAS OF
THE CWA. DRY SOUTHWEST FLOW WILL KEEP ANY MENTION OF PCPN OUT OF THE
FORECAST THROUGH AT LEAST SATURDAY. THE OPERATIONAL MODELS START TO
DIVERGE SATURDAY WITH THE GFS HOLDING ON TO THE TROUGH A BIT LONGER
WHILE THE ECMWF STARTS TO WEAKEN THE TROUGH AND BUILD A FLAT RIDGE.
BY SUNDAY THE ECMWF IS MORE AGGRESSIVE BUILDING THE RIDGE AND THE
GFS MAINTAINS A WEAK TROUGH. THE GEFS ENSEMBLE MEMBERS SHOW SOME
SUPPORT FOR BOTH SOLUTIONS SO A COMPROMISE WAS MADE. THIS MEANT
KEEPING THE HIGH TEMPS BELOW THE ECMWF GUIDANCE FOR SATURDAY AND
SUNDAY.
NO SIGNIFICANT CHANGES WERE MADE TO THE FORECAST. IF THE ECMWF
SOLUTION IS MORE CORRECT THEN WE MIGHT SEE AND OUTSIDE CHANCE AT
WEAK CONVECTION OVER THE FAR SOUTHERN CWA BY SUNDAY AS LIGHT UPSLOPE
FLOW BRINGS A BIT MORE MOISTURE BACK TO THE REGION. OTHERWISE DRY
WITH NEAR SEASONAL TEMPERATURES FOR THE EXTENDED PERIOD AND TYPICAL
AFTERNOON WINDS ONCE WE GET PAST THURSDAY. 20
&&
.AVIATION...
A FEW SHOWERS AND THUNDERSTORMS ARE POSSIBLE EARLY THIS MORNING
NORTH OF INTERSTATE 80 AS AN UPPER LEVEL WAVE OF LOW PRESSURE MOVES
NORTH. OUTSIDE OF THE WAVE THERE SHOULD BE VFR CONDITIONS TODAY.
TYPICAL SUMMER AFTERNOON WINDS ARE LIKELY TODAY WITH GUSTS EAST OF
THE SIERRA IN THE 20-25 KT RANGE.
HAZE AND SMOKE FROM CALIFORNIA FIRES WILL PRODUCE PERIODS OF
LOWERED VISIBILITY TODAY AND TUESDAY.
FAIRLY LIGHT WINDS TUESDAY. RIDGE WINDS BEGIN TO INCREASE WEDNESDAY
AND THEN GUSTY WINDS DEVELOP THURSDAY AHEAD OF A SURFACE BOUNDARY
THAT MOVES THROUGH THURSDAY NIGHT. INCREASED TURBULENCE IS HIGHLY
PROBABLE FROM LATE WEDNESDAY THROUGH THURSDAY. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
548 PM MDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 535 PM MDT TUE AUG 11 2015
UPDATED POP GRIDS TO REFLECT LASTEST MODEL AND RADAR TRENDS ACROSS
THE CWA. THE TWO MAIN AREAS OF CONCERN THROUGH THE LATE EVENING
HOURS WILL BE THE NORTHERN I-25 CORRIDOR INCLUDING EL PASO AND
PUEBLO COUNTIES AND THE FAR SE CO PLAINS NEAR THE CO/KS BORDER.
THE HRRR HAS BEEN CONSISTENTLY SHOWING A WEAK MCS DEVELOPING
ACROSS EL PASO AND PUEBLO COUNTIES BETWEEN 01-05Z TONIGHT. LAPS
AND MESOSCALE ANALYSIS SHOW 1000-1200 J/KG OF CAPE WITH DEEP
MOISTURE IN PLACE (PWATS 1.2-1.3 WITH DEW POINTS IN THE LOW 60S)
AND WEAK BULK SHEAR OF 20-25 KNOTS. ACROSS THE FAR SE PLAINS THERE
IS THE POTENTIAL FOR A FEW STRONGER STORMS AS CAPE VALUES ARE
CLOSE TO 2000 J/KG. SPC ANALYSIS ALSO DEPICTS UPPER LEVEL
VORTICITY MAXIMA IN PLACE WITH DEEP MOISTURE CONVERGENCE AND SFC
FRONTOGENESIS OCCURING...WITH THE HRRR ALSO DEVELOPING A FEW
STRONGER STORMS OVER THIS AREA BETWEEN 01ZZ-07Z. STORM ACTIVITY
SHOULD EASE BY 08Z TONIGHT AS SURFACE COOLING LIMITS INSTABILITY
OVERNIGHT. LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
SCATTERED THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS THIS
AFTERNOON...AS MOISTURE (PRECIPITABLE WATER OVER 1 INCH) AND
INSTABILITY (CAPES ABOVE 1000 J/KG MOST AREAS) REMAIN PLENTIFUL.
GENERALLY FOLLOWED THE HRRR FOR CONVECTIVE TRENDS FOR LATE AFTERNOON
INTO THE EVENING...WITH A WAVE OF STRONGER CONVECTION OVER THE
MOUNTAINS MOVING INTO THE NORTHERN I-25 CORRIDOR OVER PUEBLO AND EL
PASO COUNTIES IN THE 21Z-01Z TIME FRAME...BRINGING A THREAT OF HEAVY
RAIN TO AREAS AROUND COLORADO SPRINGS/WALDO CANYON. FARTHER
SOUTH...CONVECTION ALONG THE SOUTHERN I-25 CORRIDOR WILL EXPAND
EASTWARD INTO THE EVENING...WITH SOME POCKETS OF HEAVY RAIN ALONG
AND SOUTH OF THE ARKANSAS RIVER. MOUNTAINS AND INTERIOR VALLEYS WILL
SEE A CONTINUATION OF SCATTERED CONVECTION...WITH MODELS AND LATEST
SATELLITE LOOP SUGGESTING LEAST ACTIVITY OVER THE SOUTHWEST
MOUNTAINS AS STRONGER CONVECTION OVER AZ STAY FAIRLY FAR TO THE
WEST.
OVERNIGHT...HRRR DEVELOPS ANOTHER BAND OF HEAVIER PRECIP OVER THE
ARKANSAS VALLEY 04Z-06Z FROM FREMONT COUNTY EAST THROUGH PUEBLO AND
LA JUNTA...WITH FAIRLY VIGOROUS CONVECTION WELL INTO THE NIGHT. NOT
SURE HOW REALISTIC THIS IS GIVEN INITIAL CONVECTION THIS AFTERNOON
POTENTIALLY STABILIZING THE AIR MASS SOMEWHAT...BUT WILL MAINTAIN
POPS PAST MIDNIGHT MANY AREAS AS MOST MODELS KEEP AT LEAST SOME
PRECIP GOING PAST 06Z.
ON WEDNESDAY...EXPECT A DOWNTURN IN CONVECTION AS UPPER RIDGE
CONTINUES TO SLOWLY BUILD NORTHWARD ACROSS THE STATE...WHILE POCKET
OF DRIER AIR OVER WESTERN NM ROTATES NORTHWARD INTO THE REGION.
STILL ENOUGH RESIDUAL MOISTURE FOR ISOLATED TSRA MOST LOCATIONS IN
THE AFTERNOON...THOUGH STORM INTENSITY AND THE THREAT OF HEAVY RAIN
SHOULD BE LESS THAN THE PAST COUPLE DAYS. HIGHEST POPS WILL BE OVER
THE MOUNTAINS...ESPECIALLY NORTHERN HALF OF THE AREA WHERE SLIGHTLY
DEEPER MOISTURE WILL REMAIN. MAX TEMPS MOST LOCATIONS WILL BEGIN TO
MOVE UPWARD AS AIR MASS DRIES AND HEIGHTS BUILD...THOUGH READINGS
WILL STILL BE AT OR SLIGHTLY BELOW MID AUGUST AVERAGES BY LATE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
WEDNESDAY NIGHT THROUGH FRIDAY...A LARGE RIDGE OF HIGH PRESSURE IS
EXPECTED TO BE CENTERED OVER THE REGION THROUGH FRIDAY...KEEPING
WINDS ALOFT LIGHT. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL
AFTN AND EVE MT SHOWERS AND STORMS...AND STORMS THAT DO DEVELOP WILL
BE SLOW-MOVING AND MOVEMENT WILL BE DIFFICULT TO ANTICIPATE. LOOK
FOR MAX TEMPS TO REMAIN SOMEWHAT STEADY THROUGH THE PERIOD WITH AFTN
HIGHS IN THE 80S FOR THE HIGH VALLEYS...AND 80S TO MID 90S FOR THE E
PLAINS.
SATURDAY THROUGH MONDAY...MODELS INDICATE THAT AN UPPER SHORTWAVE
WILL CROSS MONTANA ON SATURDAY...WHICH WILL HELP TO SOMEWHAT FLATTEN
THE UPPER RIDGE AND EDGE IT TO THE SOUTH. A FRONTAL BOUNDARY WILL
DROP DOWN THE E PLAINS ON SUNDAY...BUT AT THIS TIME THERE DOES NOT
SEEM TO BE MUCH BY WAY OF SIGNIFICANT COOLING OR INCREASED
CONVECTIVE ACTIVITY WITH THIS FEATURE. LOOK FOR A CONTINUATION OF
THE DIURNAL AFTN AND EVE MT STORMS...THOUGH THERE IS A SLIGHT HINT
OF PERHAPS SOME LINGERING SHOWERS DURING THE OVERNIGHT PERIOD. AS
FOR TEMPS...MAX TEMPS WILL REMAIN IN THE 80S TO LOWER 90S FOR THE
PLAINS...AND 80S FOR THE HIGH VALLEYS.
TUESDAY...LONG RANGE MODELS SHOW A LOW DROPPING OUT OF CANADA AND
INTO MT AND THE DAKOTAS FOR TUE...SHUNTING THE UPPER RIDGE TO THE
SW. THIS IS STILL A BIT FAR OUT TIME-WISE TO MAKE SIGNIFICANT
CHANGES...BUT IF THIS SOLUTION PERSIST OVER THE NEXT FEW DAYS THEN
THIS MIGHT BRING COOLER TEMPS AND MORE PCPN FOR THE FORECAST AREA.
MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 312 PM MDT TUE AUG 11 2015
FOR LATE THIS AFTERNOON AND EVENING...FOLLOWED THE HRRR FORECAST FOR
CONVECTION...WITH TSRA MOUNTAINS MOVING ACROSS LOWER ELEVATIONS 21Z-
04Z. BEST WINDOW FOR STORMS AT KCOS AND KPUB STILL LOOKS TO BE 22Z-
01Z...WITH PERHAPS SOME WEAKER CONVECTION PERSISTING 01Z-04Z.
POTENTIAL FOR MVFR/BRIEF IFR BOTH SITES AS RAIN WILL BE HEAVY AT
TIMES. AT KALS...STILL A LOW THREAT OF TSRA INTO THE
EVENING...THOUGH STORM CHANCES LOOK LOWER HERE AS SOME DRY AIR
BEGINS TO WORK NORTHWARD OUT OF NM. TSRA DIMINISH AND SHIFT EAST
TOWARD KS OVERNIGHT...WITH A REPEAT OF MVFR STRATUS POSSIBLE AT KCOS
AND OVER THE EASTERN PLAINS AFTER ABOUT 10Z AS SURFACE WINDS BECOME
LIGHT SE. ON WED...VFR CONDITIONS FROM MID MORNING ONWARD WITH FEWER
AFTERNOON STORMS AS AIR MASS BEGINS TO DRY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
346 PM MDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
TSRA MOST NUMEROUS THIS AFTERNOON OVER THE PLAINS SOUTH OF THE
ARKANSAS RIVER...THOUGH AN ISOLATED CELL OVER TELLER AND EL PASO
COUNTIES EARLIER IN THE DAY MANAGED TO PRODUCE FLASH FLOODING OVER
WESTERN PORTIONS OF COLORADO SPRINGS AND THE EASTERN EDGE OF THE
WALDO CANYON BURN SCAR. MAIN QUESTION FOR TONIGHT WILL REVOLVE
AROUND LOCATION OF HEAVIER RAINFALL AND HOW LATE WILL STORMS
PERSIST INTO TUE MORNING. 19Z/20Z RUNS OF THE HRRR BRING ANOTHER
WAVE OF TSRA AND HEAVY RAIN THROUGH EL PASO COUNTY 00Z-02Z...THEN
ACROSS PUEBLO COUNTY AND NORTHERN PORTIONS OF THE ARKANSAS VALLEY
02Z-05Z. 12Z VERSIONS OF THE NAM/NAM 4KM/NSSL WRF ON THE OTHER
HAND...KEEP HEAVIEST RAINFALL MAINLY OVER THE MOUNTAINS
OVERNIGHT...WITH FOCUS FOR MOST TSRA SHIFTING TOWARD THE SAN JUAN
MOUNTAINS AFTER 06Z AS AREA OF DEEP TROPICAL MOISTURE OVER THE 4
CORNERS ROTATES NORTHEASTWARD. FORECAST LEANS A LITTLE TOWARD THE
HRRR...AS LAPS CAPES ARE STILL ABOVE 1000 J/KG OVER THE EASTERN
MOUNTAINS AND I-25 CORRIDOR...SUGGESTING ANOTHER BOUT OF TSRA IS
POSSIBLE. CONSIDERED A FLASH FLOOD WATCH FOR EL PASO COUNTY FOR
THIS EVENING AS HEAVY RAIN HAS FALLEN ACROSS THE REGION...THOUGH
WITH HRRR SHIFTING AXIS OF STRONGER STORMS SOUTH FAIRLY
QUICKLY...WILL REFRAIN FROM ISSUANCE AT THIS POINT. POCKETS OF
HEAVY RAIN LOOK POSSIBLE FARTHER SOUTH OVER THE PLAINS...BUT MOST
AREAS HAVE BEEN DRY ENOUGH LATELY TO TAKE AT LEAST A COUPLE HOURS
OF HEAVER PRECIP. PRECIP SLOWLY WANES OVERNIGHT...BUT NEVER
COMPLETELY COMES TO AN END...SO WILL KEEP SOME POPS GOING MANY
AREAS INTO EARLY TUE MORNING.
ON TUE...MOISTURE REMAINS IN PLACE...THOUGH HEIGHTS BEGIN TO BUILD
SLIGHTLY AS UPPER HIGH STARTS ITS NORTHWARD EXPANSION. STILL
APPEARS MOST LOCATIONS WILL SEE SCATTERED TO NUMEROUS SHOWERS AND
THUNDERSTORMS ONCE AGAIN...THOUGH EXTENT OF OVERNIGHT CONVECTION
AND POTENTIAL MCS OVER THE EASTERN PLAINS/NERN NM WILL LIKELY PLAY
A ROLE IN AMOUNT OF CONVECTIVE COVERAGE...ESPECIALLY OVER THE
PLAINS WHERE EARLY MORNING SHOWERS COULD LIMIT INSTABILITY. BROAD-
BRUSH OF SCATTERED POPS LOOKS FINE...AND WITH MOISTURE LEVELS
REMAINING RELATIVELY HIGH...LOCALLY HEAVY RAINFALL WILL AGAIN BE
POSSIBLE.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 235 PM MDT MON AUG 10 2015
UPPER RIDGE EXPANDS NORTHWARD WED-FRI...WITH THE UPPER LEVEL HIGH
PRESSURE CENTER REMAINING ALONG THE CO/NM BORDER THROUGH THE
PERIOD. TRAPPED MOISTURE UNDER THE HIGH WILL CONTINUE TO BE
RECYCLED...WITH DAILY AFTERNOON/EVENING TSRA OVER THE
MOUNTAINS...THOUGH COVERAGE MAY BECOME RATHER SPARSE WED/THU AS
TEMPERATURES ALOFT WARM. PLAINS/VALLEY TSRA CHANCES LOOK FAIRLY
LOW...THOUGH TOUGH TO RULE OUT A COUPLE STORMS DRIFTING AWAY FROM
THE MOUNTAINS EACH DAY...ESPECIALLY ALONG AND WEST OF I-25.
FORECAST HAS LOW POPS FOR ALL AREAS EACH DAY WED-FRI...WHICH MAY
BE A LITTLE OVERDONE...BUT WILL RUN WITH FOR NOW. RIDGE FLATTENS
SLIGHTLY FRI INTO THE WEEKEND...WHILE WEAK FRONT OOZES INTO THE
EASTERN PLAINS LATE SUN. EXPECT A GRADUAL INCREASE IN TSRA CHANCE
MOST LOCATIONS AS SLIGHTLY DEEPER MOISTURE MOVES IN FROM THE
WEST...WHILE LOW LEVELS ON THE PLAINS MOISTEN AND WLY STEERING
CURRENTS BECOME MORE FAVORABLE FOR STORMS TO MOVE ONTO THE PLAINS.
TEMPS FROM WED INTO THE WEEKEND WILL REMAIN AT OR SLIGHTLY ABOVE
SEASONAL AVERAGES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 235 PM MDT MON AUG 10 2015
SCATTERED TO NUMEROUS TSRA WERE OVER THE AREA THIS AFTERNOON WITH
THE GREATEST COVERAGE OF STORMS SOUTH OF THE ARKANSAS RIVER. WHILE
KPUB AND KCOS ARE CURRENTLY FREE OF CONVECTION AS OF
21Z...MESOSCALE MODELS INDICATE ANOTHER ROUND OF TSRA DROPPING
SOUTH THROUGH KCOS 00Z-02Z...THEN THROUGH KPUB 01Z-03Z...SO WILL
MAINTAIN A VCTS MENTION BOTH SITES UNTIL AROUND 03Z. AT
KALS...WILL ALSO KEEP VCTS IN THE TAF INTO THE EVENING AS
WELL...WITH STORMS ENDING 01-03Z. OVERNIGHT...TSRA MAY LINGER OVER
THE PLAINS EAST OF I-25 MUCH OF THE NIGHT...WITH A THREAT OF
SHOWERS AT TAF SITES 03Z-09Z. ON TUESDAY...TSRA WILL DEVELOP LATE
MORNING OVER THE MOUNTAINS...THEN SPREAD TO LOWER
ELEVATIONS...INCLUDING ALL TAF SITES IN THE AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PETERSEN
LONG TERM...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
401 AM MDT MON AUG 10 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 401 AM MDT MON AUG 10 2015
SHOWERS AND TSTMS CONTINUE EARLY THIS MORNING OVER THE ECNTRL PLAINS
DUE TO COMBINATION OF FNTL PASSAGE AND SOME WK MID LVL ASCENT MOVING
ACROSS. THIS ACTIVITY SHOULD BEGIN TO GRADUALLY END BY 12Z.
FOR LATER TODAY AN UPPER LEVEL HIGH WILL BEGIN TO REBUILD OVER THE
SRN ROCKIES WITH WLY FLOW ALOFT ACROSS NRN CO. MEANWHILE AS SFC
HIGH PRES BEGINS TO MOVE ESE OF THE AREA THE LOW LVL FLOW WILL
BECOME MORE SELY EAST OF THE MTNS AND KEEP DEEPER MOISTURE IN PLACE.
PW`S ARE FCST TO INCREASE INTO THE 1.00 TO 1.25 RANGE BY MID TO LATE
AFTN OVER NERN CO. AT THIS TIME CANNOT SEE ANY DEFINED DISTURBANCE
AFFECTING THE AREA THIS AFTN OR EVENING HOWEVER GRIDDED DATA DOES
SHOW SOME WL MID LVL ASCENT AFFECTING THE AREA.
OVERALL SHOULD SEE A GOOD CHC OF STORMS DEVELOPING IN AND NR THE
FOOTHILLS AND ACROSS THE PALMER DIVDE BY EARLY AFTN WITH ACTIVITY
SPREADING SLOWLY EASTWARD ACROSS THE PLAINS FM LATE AFTN INTO THE
EARLY EVENING HOURS. ONE THING THAT MODELS ARE NOT SHOWING IS A
DENVER CYCLONE WHICH IS A BIT SURPRISING CONSIDERING THE LOW LVL
FLOW WILL BE SELY. IF ONE DOES DVLP THE CONVERGENCE ZONE COULD END
BEING A FOCUS FOR HEAVIER RAINFALL OVER PORTIONS OF THE URBAN
CORRIDOR OR JUST TO THE EAST. WITH HIGH PW`S SOME STORMS WILL HAVE
THE POTENTIAL TO PRODUCE 1 TO 2 INCHES OF RAIN WITH LOCALLY HIGHER
AMOUNTS POSSIBLE IN A FEW SPOTS IF THE DENVER CONVERGENCE ZONE DOES
DEVELOP. AS FOR TEMPS 850-700 MB TEMPS DROP A FEW MORE DEGREES TODAY
SO READINGS WILL HOLD IN THE 80S ACROSS NERN CO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 401 AM MDT MON AUG 10 2015
LITTLE CHANGE TO THE FORECAST PACKAGE FOR THE LATTER FORECAST
PERIODS THIS TIME AROUND. MEDIUM RANGE MODELS CONTINUE INDICATING
THAT A STRONG UPPER LEVEL RIDGE WILL BUILD OVER COLORADO AND THE
FOUR CORNERS REGION THROUGH MOST OF THE WEEK. SPECIFIC HUMIDITY
FIELDS CONTINUE SHOWING HEALTHY AMOUNTS OF MOISTURE ROTATING OVER
THE STATE FROM THE SOUTH THROUGH THE FORECAST PERIOD. BUT MODEL
QPF CHARTS ARE NO LONGER SHOWING ANY PERIODS OF PARTICULARLY HEAVY
RAINFALL. MODEL SOUNDINGS FOR TUESDAY AND WEDNESDAY SHOW THAT
PRECIPITABLE WATER VALUES AROUND DENVER WILL REMAIN AT OR SLIGHTLY
ABOVE 1 INCH...WHICH MEANS THAT THUNDERSTORMS WILL BE CAPABLE OF
PRODUCING LOCALLY HEAVY RAINFALL. STORM MOTIONS ARE ALSO EXPECTED
TO BE WEAK...MEANING THAT WE WILL HAVE TO WATCH OUT FOR LOCAL
FLOODING PROBLEMS WHEN STORMS DEVELOP.
MODEL SOUNDINGS ALSO SHOW THAT THE AIRMASS WILL BE MOST UNSTABLE
ON TUESDAY...AND THEN STABILIZE LATER IN THE WEEK. THE INCREASE IN
STABILITY WILL BE DUE TO WARMING MID-LEVEL TEMPERATURES UNDER THE
CENTER OF THE SUBSIDENT HIGH PRESSURE ALOFT. THE EXPECTED PRESENCE
OF THE SUBTROPICAL MOISTURE AT MID AND UPPER LEVELS WILL MAKE IT
HARD TO COMPLETELY REMOVE THE MENION OF SHOWER ACTIVITY THOUGH.
THEREFORE...THE FORECAST WILL HAVE THE HIGHEST CHANCES OF SHOWERS
OVER THE MOUNTAINS IN THE AFTERNOONS AND EVENINGS WITH THE PLAINS
HAVING A SLIGHT CHANCE OF THUNDERSTORMS IN THE EVENINGS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 401 AM MDT MON AUG 10 2015
LIGHT DRAINAGE WINDS HAVE DEVELOPED EARLY THIS MORNING HOWEVER ONCE
MIXING OCCURS EXPECT WINDS WILL GRADUALLY BECOME MORE EARLY BY LATE
MORNING AND THEN MORE SELY BY AFTN. NEITHER THE HRRR OR RAP IS
SHOWING A DENVER CYCLONE THIS AFTN. IF ONE DOES DVLP THEN WIND
DIRECTIONS COULD END UP BEING CONSIDERABLY DIFFERENT DEPENDING ON
WHERE THE CONVERGENCE ZN SETS UP. TSTM THREAT WILL INCREASE BY
EARLY AFTN WITH SOME POTENTIAL FOR LOWER CEILINGS/VISIBILITIES IF
AIRPORT TAKES A DIRECT HIT FROM A STRONGER STORM. FURTHERMORE
CURRENT DATA SUGGESTS TSTM THREAT COULD CONTINUE INTO THE EARLY
EVENING HOURS AS WELL SO WILL HAVE TO KEEP IN AT LEAST A PROB GROUP
THRU 03Z. OVERNIGHT THERE WILL BE SOME POTENTIAL FOR STRATUS/FOG
TOWARDS MORNING BASED ON THE HI RES MODELS AS THEY SHOW A DENVER
CYCLONE NR DIA.
&&
.HYDROLOGY...
ISSUED AT 401 AM MDT MON AUG 10 2015
A FEW THUNDERSTORMS MAY DROP FROM 1 TO 2 INCHES OF RAIN IN 45
MINUTES OR LESS ALONG THE FRONT RANGE...PLAINS AND ACROSS THE
PALMER DIVIDE THIS AFTERNOON INTO THE EARLY EVENING HOURS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...RPK
LONG TERM...DANKERS
AVIATION...RPK
HYDROLOGY...RPK
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1148 PM MDT SUN AUG 9 2015
.SHORT TERM...(TONIGHT THROUGH MONDAY NIGHT)
ISSUED AT 302 PM MDT SUN AUG 9 2015
SIGNIFICANTLY DRIER AIR WILL REMAIN OVER THE AREA OVERNIGHT. THE
12Z KGJT SOUNDING HAD PRECIPITABLE WATER OF 0.63 IN. DEWPOINTS
WILL CONTINUE TO DROP INTO THE 40S AND EVEN UPPER 30S AT SOME
LOCATIONS. CAPE VALUES ARE PROJECTED IN THE RAP13 AND HRRR TO
REMAIN LOW AS WELL...SO CONVECTION EARLY THIS EVENING WILL BE
WEAK AND ONLY OVER AND DOWNWIND OF RIDGES. ONLY LIGHT
PRECIPITATION IS EXPECTED WITH THESE STORMS ALONG WITH GUSTY
WINDS. THUNDERSTORMS SHOULD DISSIPATE WELL BEFORE MIDNIGHT WITH
NEARLY CLEAR SKIES EXPECTED AGAIN OVERNIGHT.
MOISTURE BEGINS TO INCREASE FROM THE SOUTH AGAIN ON MONDAY...SO EXPECTING
SCATTERED ACTIVITY IN THE SAN JUANS MONDAY EVENING AS THE 12Z NAM
AND GFS INDICATE A H5 VORTICITY MAX REACHING THE FOUR CORNERS
MONDAY EVENING. THE EURO IS A BIT SLOWER WITH THIS ENERGY...BUT IN
ANY CASE IT DOES LOOK LIKE SHOWERS AND ISO TSTORMS WILL CONTINUE
THROUGH THE OVERNIGHT HOURS ON MONDAY NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 302 PM MDT SUN AUG 9 2015
TUESDAY MORNING WILL BE A MUGGY ONE...WITH CLOUD COVER AND RAIN
SHOWERS ACROSS MUCH OF THE REGION BY MIDDAY. MONSOONAL MOISTURE
WILL BE AT ITS HIGHEST THIS WEEK ON TUESDAY AFTERNOON AS
PRECIPITABLE WATER VALUES ACROSS THE FOUR CORNERS REACH UPWARDS OF
1.2 INCHES AND MORE THAN 0.75 INCHES REACHING THE UT/CO/WY BORDER.
THOUGH DEEP MOISTURE WILL BE IN PLACE...NOT FEELING VERY CONFIDENT
ON THE THREAT OF FLASH FLOODING SINCE WE WILL LIKELY BE DEALING
WITH WIDESPREAD CLOUD COVER AGAIN AND LACK OF LIFTING DUE TO
DAYTIME HEATING. LOCALIZED FLASH FLOODING COULD OCCUR IF THERE IS
SOME CLEARING WHICH PRODUCES ENOUGH LIFT FOR MORE VERTICALLY
SUPPORTED THUNDERSTORMS. WEDNESDAY WILL LIKELY BE MORE OF A THREAT
DAY FOR FLASH FLOODING WITH SKY CONDITIONS LESS CLOUDY BUT WITH
DEEP MOISTURE STILL IN PLACE. FORECAST CONVECTIVE INDICES ON THE
NAM ARE MORE FAVORABLE FOR HEAVY RAIN PRODUCING THUNDERSTORMS ON
WEDNESDAY THAN TUESDAY...SO THESE DAYS WILL NEED TO BE WATCHED FOR
POTENTIAL IMPACTS. THE LACK OF JET SUPPORT WILL KEEP STEERING
WINDS LIGHT THROUGH THE END OF THE WEEK SO ANY SHOWERS AND STORMS
WHICH DEVELOP WILL MOVE SLOWLY. SOME DRYING OCCURS LATER IN THE
WORK WEEK DUE TO HIGH PRESSURE AMPLIFYING OVER THE ROCKIES...BUT
PRECIPITABLE WATER VALUES REMAIN NEAR THREE QUARTERS OF AN INCH
SO DIURNALLY INDUCED SHOWERS AND THUNDERSTORMS WILL DEVELOP
EVERYDAY OVER HIGHER TERRAIN.
NEXT SATURDAY...A TROUGH OVER THE PACIFIC NORTHWEST IS PROGGED TO MOVE
INLAND NORTH OF COLORADO. THE INTERACTION OF THIS TROUGH WITH THE
HIGH PRESSURE IN PLACE OVER THE ROCKIES WILL DRIVE A 50 KT JET
INTO NE UTAH AND NW COLORADO AND POTENTIALLY CREATE MORE
CONVECTIVE ACTIVITY UP NORTH NEXT WEEKEND.
BUMPED HIGH TEMPS UP A COUPLE OF DEGREES IN THE LOWER VALLEYS
TOWARD THE END OF THE WEEK CLOSER TO MOS GUIDANCE FOR A MIDDLE
GROUND SOLUTION. FEEL THAT MOS GUIDANCE IS TOO HOT BUT PREVIOUS
FORECAST WAS TOO LOW CONSIDERING THE EXPECTED AMOUNT OF SUNSHINE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1142 PM MDT SUN AUG 9 2015
EXPECT VFR CONDITIONS THROUGH MONDAY MORNING ACROSS THE REGION.
INCREASING MOISTURE FROM THE SOUTH WILL BRING ISOLATED/SCATTERED SHOWERS
AND THUNDERSTORMS SPREADING SOUTH TO NORTH LATE MONDAY AFTERNOON
AND CONTINUING MONDAY NIGHT. THE BEST FOCUS WILL BE OVER
SOUTHWESTERN COLORADO AND SOUTHERN AND CENTRAL MOUNTAIN LOCATIONS.
STRONGER CELLS WILL HAVE CIGS OBSCURING MOUNTAIN TOPS BY LATE
MONDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...CC/JAM
LONG TERM...JAM
AVIATION...MPM
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
345 AM EDT MON AUG 10 2015
.DISCUSSION...
TODAY-TONIGHT...
POPS WELL BLO CLIMO AVG IN THE WAKE OF A DISSIPATING FRONTAL
BOUNDARY OVER S FL/NRN BAHAMAS. THE TROF WILL COMBINE WITH A NARROW
H100-H70 HI PRES RIDGE SPANNING THE ERN SEABOARD TO GENERATE A DEEP
NERLY FLOW REGIME OVER THE FL PENINSULA. PATTERNS SUCH AS THIS ONE
ARE ONE OF THE MOST STABLE FOR CENTRAL FL...AND THIS ONE WILL BE NO
DIFFERENT.
A MID LVL THERMAL RIDGE ASSOCD WITH THE RIDGE CURRENTLY BLANKETS
MUCH CENTRAL FL WITH H70 TEMPS BTWN 9-10C AND H50 TEMPS ARND -5C...
YIELDING AVG LAPSE RATES ARND 5.5C/KM THRU THE LYR. H85-H70 LAPSE
RATES ARE NO BETTER WITH VALUES ARND 5C/KM. THE 00Z RAOBS AT
KJAX/KXMR SHOW PWAT VALUES BTWN 1.6"-1.7"...WHILE RAP ANALYSIS
INDICATES H100-H70 MEAN RH VALUES STRUGGLING TO HOLD THE 70PCT
LINE...H85-H50 VALUES LARGELY ARND 40PCT.
AVAILABLE MOISTURE IS SUFFICIENT TO SUPPORT ISOLD CONVECTION...AS
RADAR TREND HAS SHOWN OVER THE PAST SVRL HRS OVER THE ATLC WATERS...
BUT LITTLE MORE. FURTHERMORE...THE ONSHORE FLOW WILL PROMOTE THE
EARLY FORMATION OF THE EAST COAST SEA BREEZE THAT WILL FAVOR THE W
FL PENINSULA FOR DIURNAL CONVECTION...POPS AOB 20PCT. SEA BREEZE
KEEP COASTAL TEMPS IN THE U80S...INTERIOR TEMPS IN THE L90S. MIN
TEMPS IN THE L/M70S.
A BROADLY WEAK BERMUDA RIDGE WL ATTEMPT TO BECOME RE-ESTABLISHED
NEAR CENTRAL FL DURING TUE. THE FEATURE WL BE NUDGED SWD HOWEVER
BY AN APCHG SHORTWAVE OVERNIGHT AND INTO WED. INCRSG RAIN CHCS WL
OCCUR AT MIDWEEK WITH UPR TROUGH AND ASCD SFC BOUNDARY MOVING INTO
N FL DURING WED...INCRSG LOCAL MOISTURE AND LIKELIHOOD OF AFTN
SHOWERS AND STORMS ACROSS THE AREA. SLIGHTLY HIGHER RAIN CHCS ARE
INDICATED OVER NORTHERN COUNTIES INTO THE OVERNIGHT PERIOD WHEN
BOUNDARY IS ADVERTISED STALLING NORTH OF CENTRAL FL.
THE WEAKENING BOUNDARY WI LINGER OVER N FL INTO LATE WEEK WITH
AMPLE LAYER MOISTURE ACROSS THE REGION ALONG WITH FAVORABLE
STEERING REGIME TO PRODUCE SCT TO NMRS DIURNAL SHOWERS AND SLOW
MOVING STORMS. A GENERALLY WEAK PRESSURE PATTERN WL PREVAIL FROM
THE WEEKEND INTO NEXT WEEK BRINGING HIGHER THAN NORMAL RAIN
COVERAGE AT LEAST INTO EARLY NEXT WEEK.
&&
.AVIATION...THRU 11/12Z
WINDS: THRU 10/14Z...NE AOB 4KTS. BTWN 10/14Z-10/16Z...E/NE 7-10KTS
CONTG THRU 11/02Z. BTWN 11/02Z-11/04Z...BCMG VRBL AOB 3KTS.
VSBY/WX/CIGS: THRU 10/12Z...PTCHY MVFR BR/LCL LIFR FG VCNTY
KVRB/KFPR...BRIEF ISOLD MVFR SHRAS COASTAL SITES. BTWN 10/12Z-
10/16Z...ISOLD MVFR SHRAS COASTAL SITES. BTWN 10/16Z-10/24Z...ISOLD
IFR TSRAS INTERIOR SITES. AFT 11/04Z...SLGT CHC MVFR SHRAS BTWN KTIX-
KSUA.
&&
.MARINE...
TODAY-TONIGHT...WEAK PGRAD IN THE WAKE OF A DISSIPATING FRONTAL
TROF WILL COMBINE WITH A HIGH PRES RIDGE OVER THE DEEP SOUTH TO
GENERATE A LIGHT E/NE BREEZE TODAY...BCMG A LIGHT TO GENTLE S/SW
BREEZE OVERNIGHT AS A NEW FRONTAL BOUNDARY WORKS ITS WAY INTO
THE DEEP SOUTH. SEAS AOB 2FT NEARSHORE AND 2-3FT OFFSHORE...
MAINLY IN AN ERLY SWELL.
PRESENCE OF A WEAK RIDGE OVER THE WATERS AT MIDWEEK WL PRODUCE
FAVORABLE BOATING CONDITIONS WITH SEAS AROUND 2 FT OR LESS NEAR
SHORE AND 2 TO 3 FT OVER THE OUTER WATERS. THESE SIMILAR
CONDITIONS CAN BE EXPECTED INTO THE WEEKEND AS WELL WITH AN
INCREASE IN STORMS NEAR THE IMMEDIATE COAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 88 74 92 74 / 10 0 20 20
MCO 92 74 95 75 / 20 0 30 20
MLB 88 76 91 75 / 10 10 30 20
VRB 89 73 92 73 / 20 20 30 30
LEE 93 74 94 76 / 20 10 30 20
SFB 92 73 95 76 / 20 0 30 20
ORL 93 74 94 77 / 20 0 30 20
FPR 89 72 92 72 / 20 20 30 30
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....PENDERGRAST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
945 PM EDT TUE AUG 11 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL MOVE INTO THE AREA WEDNESDAY...THEN PUSH
SOUTH INTO NORTHERN FLORIDA THURSDAY BEFORE DISSIPATING OVER THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
MAIN BATCH OF CONVECTION WAS NORTHWEST OF LAKE MOULTRIE HEADED
SOUTHEAST TOWARD THE COAST. LATEST HRRR INDICATES THIS ACTIVITY
WILL AFFECT MAINLY NORTHERN BERKELEY AND CHARLESTON COUNTIES THE
NEXT SEVERAL HOURS BEFORE DIMINISHING WHILE MORE ISOLATED SHOWERS
AND A FEW THUNDERSTORMS POSSIBLY IMPACTS THE REST OF THE FORECAST
AREA AHEAD OF AN APPROACHING COLD FRONT CURRENTLY ACROSS WESTERN
SC/NORTHERN GA. HOWEVER...AFTER MIDNIGHT MOST CONVECTION SHOULD
BE OFF THE SOUTH CAROLINA COAST AS THE FRONT SHIFTS SOUTHEAST
CLOSER TO THE SC COAST...POSSIBLY BRUSHING CHARLESTON COUNTY. LOWS
GENERALLY IN THE MID 70S INLAND AND UPPER 70S NEAR THE COAST.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY/...
WEDNESDAY...THE COLD FRONT WILL MEANDER ALONG THE COAST THOUGH THE
AFTERNOON SEA BREEZE MAY PUSH IT BACK INLAND. MODEL PWATS SHOW ONLY
A SLIGHT AMOUNT OF DRIER AIR TRYING TO PUSH IN FROM THE NORTHWEST
LATE IN THE DAY. THUS THE RAIN CHANCES INLAND WILL BE LIMITED AT
BEST. CLOSER TO THE COAST WHERE THE FRONT...SEA BREEZE AND DEEPER
MOISTURE EXIST...WE EXPECT SCATTERED AFTERNOON/EVENING SHOWERS AND
TSTMS. THE BEST COVERAGE LOOKS TO BE ACROSS SOUTHEAST GEORGIA DUE TO
DEEPER MOISTURE. HIGHS WILL RANGE FROM UPPER 80S ALONG THE COAST TO
LOWER 90S FAR INLAND.
THURSDAY...SOME DRIER AIR SPREADS INTO THE AREA AS HIGH PRESSURE
BUILDS FROM THE NORTH. PWATS EXPECTED TO DROP BELOW 1.5" DURING THE
DAY WITH SFC DEWPOINTS IN THE UPPER 60S EXCEPT ALONG THE COAST.
HOWEVER WITH TEMPS IN THE LOWER 90S AND SOME SHORTWAVE ENERGY
APPROACHING DURING THE AFTERNOON...ISOLATED SHOWERS AND TSTMS
EXPECTED.
FRIDAY...NORTHEAST LOW-LEVEL FLOW WILL GRADUALLY INCREASE MOISTURE
OFF THE ATLANTIC THOUGH INLAND AREAS WILL STILL BE FAIRLY DRY
THROUGHOUT THE COLUMN. A DEEPENING UPPER TROUGH OVER THE SOUTHEAST
COAST WILL SPREAD VORTICITY ENERGY INTO THE AREA FROM THE SOUTH.
THIS COMBINED WITH CONVERGENCE ALONG THE AFTERNOON SEA BREEZE SHOULD
PRODUCE SCATTERED CONVECTION...HIGHEST COVERAGE ACROSS FAR SOUTHEAST
PORTIONS. HIGH TEMPS WILL BE IN THE UPPER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
A STALLED FRONT TO THE SOUTH AND EAST ALONG WITH SOME WEAK AREAS OF
LOW PRESSURE WILL PERSIST THROUGH THE WEEKEND BEFORE EVENTUALLY
DISSIPATING EARLY NEXT WEEK AS HIGH PRESSURE TRIES TO BUILD FROM THE
SOUTHEAST. THIS PATTERN MEANS THERE WILL BE SOME SHOWER AND
THUNDERSTORM CHANCES THROUGH THE PERIOD...ESPECIALLY FOR SOUTHEAST
GEORGIA AND COASTAL SC WHICH WILL BE NEARER THE DEEPER MOISTURE.
TEMPS SHOULD BE ABOUT NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION /02Z WEDNESDAY THROUGH SUNDAY/...
BOTH KCHS AND KSAV REMAINED DRY THROUGH THE AFTERNOON AND WITH NO
IMPENDING THREATS FOR PRECIPITATION THIS EVENING DRY CONDITIONS WERE
KEPT IN THE TAFS THROUGH THE FORECAST PERIOD. SHOWERS AND
THUNDERSTORMS ARE STILL POSSIBLE AS THE FRONT APPROACHES LATE
TONIGHT FOR KCHS...AND TOMORROW MORNING FOR KSAV...BUT COVERAGE OF
PRECIP LOOKS LOW ENOUGH TO JUSTIFY KEEPING IT OUT OF THE TAF FOR
NOW.
VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AS HEIGHTS ALOFT
BEGIN TO RISE AND MID AND UPPER LEVEL CLOUD DECKS ERODE THROUGH THE
NIGHT. LIGHT NORTHERLY WINDS WILL FILL IN AS THE FRONT MOVES THROUGH
THE TERMINALS TOMORROW MORNING BEFORE THE SEABREEZE PASSES THROUGH
IN THE AFTERNOON.
EXTENDED AVIATION OUTLOOK...BRIEF FLIGHT RESTRICTIONS POSSIBLE EACH
DAY IN AFTERNOON/EVENING SHOWERS AND TSTMS.
&&
.MARINE...
TONIGHT...LOW-LEVEL JETTING WILL OCCUR OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT. 15-20 KT LOOKS REASONABLE FOR MOST LEGS.
A FEW STRONG TSTMS COULD ALSO OCCUR OVERNIGHT WITH GUSTS TO 35
KT...LOCALLY HEAVY RAINFALL REDUCING VSBYS TO LESS THAN 1 NM AND
CLOUD TO WATER LIGHTNING...MAINLY OFF CHARLESTON COUNTY.
WEDNESDAY THROUGH SUNDAY NIGHT...A WEAK COLD FRONT WILL DROP
INTO THE WATERS LATE WEDNESDAY THEN STALL JUST OFF THE COAST
WEDNESDAY NIGHT AS HIGH PRESSURE BUILDS FROM THE NORTHWEST. A WEAK
PRESSURE PATTERN WILL EXIST THROUGH WEDNESDAY NIGHT WITH THE MAIN
DRIVE BEING A MODEST AFTERNOON SEA BREEZE ALONG THE COAST
WEDNESDAY. BY THURSDAY AS HIGH PRESSURE STRENGTHENS FROM THE NORTH
AND A COASTAL TROUGH DEVELOPS...A NORTHEAST FLOW SETS UP OVER THE
WATERS WITH INCREASING WINDS AND SEAS. HOWEVER...CONDITIONS
CURRENTLY EXPECTED TO REMAIN BELOW ADVISORY THRESHOLDS THROUGH THE
WEEKEND.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RJB
SHORT TERM...JRL
LONG TERM...RJB
AVIATION...CEB
MARINE...JRL/ST
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS PEACHTREE CITY GA
152 PM EDT MON AUG 10 2015
.PREV DISCUSSION... /ISSUED 413 AM EDT MON AUG 10 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GULF OF MEXICO ALLOWING FOR
SOME LOW LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED
TO ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER CLEAR
FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING ANYTHING
WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO DEVELOPMENT
SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS SHOULD BE
SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR SLIGHTLY BELOW
WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
18Z UPDATE...
CURRENT RADAR SHOWS SCATTERED SHOWERS DEVELOPING AROUND ALL TAF
SITES. A MORE ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS WAS NOTED
OVER NE AL AND MOVING ESE. HI-RES MODELS BRING TH MORE ORGANIZED
CONVECTION TO THE NW ACROSS THE ATLANTA AREA TAF SITES BETWEEN 20-
24Z. WILL CONTINUE TO SHOW TEMPO TSRA 20-24Z FOR NOW... WITH VCSH
HANDLING THE CURRENT SHOWERS UNTIL 20Z. SCATTERED SHOWERS MAY LINGER
OVERNIGHT... WITH MVFR CIGS EXPECTED TO SETTLE IN OVER MOST TAF
SITES BY 09Z TUE... THEN PERSIST THROUGH 15-16Z TUE. A PRE-FRONTAL
TROUGH SHOULD PUSH SOUTH OF ATLANTA TAF SITES BY 17-18Z... WITH A
DRIER NW FLOW SPREADING VFR CONDITIONS INTO THE AREA TUE AFTERNOON.
//ATL CONFIDENCE...18Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
/39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1105 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR TONIGHT AHEAD OF SHORTWAVE TROUGH.
THE CONVECTION ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER
AND THUNDERSTORM COVERAGE TODAY AND THIS APPEARS REASONABLE WITH
SHORTWAVE TROUGH TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE
CONSENSUS MOS SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED OUTSIDE OF SHOWER/THUNDERSTORM ACTIVITY
THIS AFTERNOON AND TONIGHT.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY LATE AFTERNOON/EARLY THIS EVENING...BUT GIVEN LOW
CONFIDENCE IN TIMING AND AREAL COVERAGE...HAVE NOT INCLUDED
CONVECTION IN THE TAFS ATTM. WINDS WILL CONTINUE OUT OF THE SOUTH
AT AROUND 5 TO 10 KNOTS THROUGH TONIGHT...BECOMING MORE
SOUTHWESTERLY OVERNIGHT.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
744 AM EDT MON AUG 10 2015
.PREV DISCUSSION... /ISSUED 413 AM EDT MON AUG 10 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GOM ALLOWING FOR SOME LOW
LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED TO
ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER
CLEAR FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING
ANYTHING WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO
DEVELOPMENT SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS
SHOULD BE SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR
SLIGHTLY BELOW WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
12Z UPDATE...
HI-RES MODELS CONTINUE TO BRING AN ORGANIZED LINE OF SHOWERS AND
THUNDERSTORMS ACROSS THE AREA THIS AFTERNOON. THE HRRR SEEMS TO
HAVE THE BEST HANDLE ON THE SYSTEM AND HAS HAD MORE RUN TO RUN
CONSISTENCY. WINDS WILL REMAIN ON THE WEST SIDE.
//ATL CONFIDENCE...12Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
633 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR THIS MORNING AND TONIGHT AHEAD OF SHORTWAVE TROUGHS.
BELIEVE A LEAD SHORTWAVE TROUGH WAS HELPING SUPPORT THE SCATTERED
SHOWERS IN THE FORECAST AREA EARLY THIS MORNING. THE CONVECTION
ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER AND THUNDERSTORM
COVERAGE TODAY AND THIS APPEARS REASONABLE WITH SHORTWAVE TROUGH
TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE CONSENSUS MOS
SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A FEW SHOWERS HAVE DEVELOPED OVER PORTIONS OF THE MIDLANDS AND
CSRA EARLY THIS MORNING. GIVEN LATEST RADAR TRENDS...HAVE INCLUDED
A TEMPO GROUP FOR SHOWERS FOR AGS/DNL/CAE/CUB UNTIL 13Z. CLOUDS
AND A 15 TO 20 KNOT LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL
BEFORE SUNRISE. LIGHT SE WINDS EARLY BECOMING SOUTH TO SOUTHWEST 5
TO 10 KNOTS BY LATE MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY LATE AFTERNOON/EARLY THIS EVENING...BUT GIVEN LOW
CONFIDENCE IN TIMING AND AREAL COVERAGE...HAVE NOT INCLUDED
CONVECTION IN THE TAFS ATTM.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
526 AM EDT MON AUG 10 2015
.SYNOPSIS...
A PRESSURE RIDGE WILL PUSH FARTHER OFF THE COAST TODAY. MOISTURE
WILL INCREASE IN THE FORECAST AREA AHEAD OF AN APPROACHING COLD
FRONT. THE FRONT WILL MOVE THROUGH THE AREA LATE TUESDAY AND
TUESDAY NIGHT. NUMEROUS SHOWERS AND THUNDERSTORMS WILL BE
ASSOCIATED WITH THE FRONT. DRYING WITH A DIMINISHED SHOWER CHANCE
WILL OCCUR BEHIND THE FRONT WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE RIDGE ALONG THE COAST WILL BE SHIFTING FARTHER OFFSHORE
THROUGH TONIGHT. AN INCREASE IN MOISTURE SHOULD OCCUR IN A
SOUTHERLY FLOW. THE MODELS INDICATE UPPER SUPPORT WILL OCCUR
THROUGH TONIGHT WITH AN H5 DIFLUENT PATTERN. ENHANCED LIFT MAY
OCCUR THIS MORNING AND TONIGHT AHEAD OF SHORTWAVE TROUGHS.
BELIEVE A LEAD SHORTWAVE TROUGH WAS HELPING SUPPORT THE SCATTERED
SHOWERS IN THE FORECAST AREA EARLY THIS MORNING. THE CONVECTION
ALLOWING MODELS GENERALLY SHOWED SCATTERED SHOWER AND THUNDERSTORM
COVERAGE TODAY AND THIS APPEARS REASONABLE WITH SHORTWAVE TROUGH
TIMING NOT DIURNALLY FAVORABLE. THE GUIDANCE CONSENSUS MOS
SUPPORTED POPS OF 20 TO 30 PERCENT TODAY.
THE THUNDERSTORM CHANCE SHOULD INCREASE TONIGHT AHEAD OF THE NEXT
SHORTWAVE TROUGH. THE HRRR DISPLAYED CONSIDERABLE COVERAGE ABOUT
TO ENTER THE FORECAST AREA FROM THE WEST TOWARD SUNSET. THE SPC
WRF SHOWED THIS AREA DIMINISHING AS IT MOVED THROUGH THE FORECAST
AREA DURING THE 800 PM TO 100 AM TIME FRAME. FORECASTED A POP
AROUND 40 PERCENT CLOSE TO THE GUIDANCE CONSENSUS.
FOLLOWED THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE TODAY.
LEANED TOWARD THE WARMER GUIDANCE BECAUSE OF EXPECTED CLOUDINESS
AND MIXING TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
CONVERGENCE INTO A PRE-FRONTAL TROUGH AND COLD FRONT TUESDAY AND
TUESDAY NIGHT PLUS UPPER-LEVEL TROUGHING SHOULD LEAD TO NUMEROUS
SHOWERS AND THUNDERSTORMS TUESDAY AND TUESDAY NIGHT. WE LEANED
TOWARD THE HIGHER POP GUIDANCE. SHOWER AND THUNDERSTORM COVERAGE
MAY BE GREATEST EARLY TUESDAY AHEAD OF A MID-LEVEL SHORTWAVE
TROUGH AND AGAIN TUESDAY EVENING NEAR STRONGER CONVERGENCE JUST
AHEAD OF THE FRONT. THE MODELS INDICATE MODERATE INSTABILITY AND
PRECIPITABLE WATER OVER 2 INCHES. THUNDERSTORMS WITH DAMAGING WIND
AND EXCESSIVE RAIN WILL BE POSSIBLE. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
THE GFS AND ECMWF INDICATE UPPER TROUGHING CONTINUING OVER THE
EASTERN PART OF THE NATION THROUGH THE MEDIUM-RANGE PERIOD. THE
MODELS DISPLAY A FRONTAL SYSTEM LINGERING NEAR THE SOUTHEAST
COAST. DEEP MOISTURE APPEARS TO REMAIN SOUTH AND EAST OF THE
FORECAST AREA. THE GFS AND ECMWF MOS HAVE TEMPERATURES NEAR
CLIMATOLOGY WITH POPS 10 TO 30 PERCENT.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
A FEW SHOWERS HAVE DEVELOPED OVER THE WESTERN MIDLANDS AND CSRA
EARLY THIS MORNING. GIVEN LATEST RADAR TRENDS...HAVE INCLUDED A
TEMPO GROUP FOR SHOWERS FOR AGS/DNL UNTIL 12Z. CLOUDS AND A 15 TO 20
KNOT LOW LEVEL JET SHOULD LIMIT FOG POTENTIAL BEFORE SUNRISE. LIGHT
SE WINDS EARLY BECOMING SOUTH TO SOUTHWEST 5 TO 10 KNOTS BY LATE
MORNING.
SCATTERED SHOWERS AND THUNDERSTORMS EXPECTED TO DEVELOP ACROSS THE
AREA BY EARLY THIS EVENING...BUT GIVEN LOW CONFIDENCE IN TIMING
AND AREAL COVERAGE...HAVE NOT INCLUDED CONVECTION IN THE TAFS ATTM.
EXTENDED AVIATION OUTLOOK...SHOWERS AND THUNDERSTORMS POSSIBLE
TUESDAY THROUGH TUESDAY NIGHT AS AN APPROACHING FRONTAL BOUNDARY
MOVES THROUGH THE REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
413 AM EDT MON AUG 10 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...
A COLD FRONT WILL IMPACT THE CWFA IN THE SHORT TERM PORTION OF THE
FORECAST AREA. THE FRONT CURRENTLY STRETCHES FROM THE MID
MISSISSIPPI RIVER VALLEY TO THE TENNESSEE VALLEY. THE BOUNDARY WILL
SLIP SLOWLY SOUTH TODAY...AND CROSS MUCH OF THE FORECAST AREA ON
TUESDAY.
DEWPOINTS HAVE BEGUN TO CREEP UP ACROSS THE CWFA...A SIGN OF
INCREASING LOW LEVEL MOISTURE. PRECIPITATION CHANCES WILL INCREASE
TODAY AHEAD OF THE FROPA. HI-RES MODELS ARE SHOWING A RATHER
ORGANIZED LINE OF SHOWERS AND THUNDERSTORMS MOVING SOUTH ACROSS
NORTH AND CENTRAL GA THIS AFTERNOON. THE LOCAL WRF AND THE HRRR DO
DIFFER A BIT...WITH THE WRF BEING LATER WITH THE CONVECTION. HAVE
TRIED TO COMPROMISE ON TIMING. BOTH MODELS...HOWEVER...INDICATE VERY
GOOD RAIN CHANCES ACROSS NORTHERN GA TODAY. SO...HAVE RAISED POPS TO
LIKELY IN THAT REGION.
ATMOS WILL BE FAVORABLE FOR STRONG TO ISOLATED SEVERE STORMS. GOOD
SURFACE INSTABILITY WILL BE PRESENT...WITH AN ASSIST BY A SHORTWAVE
DROPPING SOUTH IN THE MID LEVEL FLOW. MODELS CURRENTLY KEEP LAPSE
RATES FAIRLY WEAK...BUT THE SHORTWAVE WILL PROVIDE SOME LIFT.
COPIOUS CLOUD COVER SHOULD HELP LIMIT SEVERE STORM COVERAGE.
THE MAIN FOCUS FOR TODAYS CONVECTION SHOULD BE ANY
OUTFLOW/DIFFERENTIAL HEATING BOUNDARIES FROM THE THUNDERSTORM
COMPLEX CURRENTLY ACROSS THE MID MISSISSIPPI RIVER VALLEY. THE
ACTUAL FRONTAL BOUNDARY WILL PROVIDE A FOCUS FOR STORMS TOMORROW.
TEMPS SHOULD BE A FEW DEGREES COOLER THAN YESTERDAYS VALUES DUE TO
THE INCREASED CLOUD COVER. TEMP/DEWPOINT VALUES REMAIN BELOW
CRITICAL THRESHOLDS FOR A HEAT ADVISORY AT THIS TIME.
NLISTEMAA
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GUIDANCE IN DECENT AGREEMENT WITH AFOREMENTIONED FRONTAL BOUNDARY
IN THE SHORT TERM LINGERING ACROSS THE SOUTHERN TIER OF THE CWA
FOR TUESDAY NIGHT INTO WEDNESDAY...THEN FINALLY PUSHING JUST SOUTH
OF THE AREA AND BECOMING MORE DIFFUSE THRU THE REST OF THE WORK
WEEK. HAVE TRENDED CHANCE TO SLIGHT POPS ACCORDINGLY AND ADVECTION
OF ABNORMALLY DRY AIR IN FROM THE NW WILL ALLOW FOR A RATHER
PLEASANT WED AND THURS WITH SLIGHTLY BELOW NORMAL HIGHS AND
RESULTANT AFTERNOON RH VALUES IN THE 40S.
FOR FRIDAY INTO THE WEEKEND...A BROAD/WEAK AREA OF LOW PRESSURE
LOOKS TO DEVELOP ACROSS THE NORTHERN GOM ALLOWING FOR SOME LOW
LEVEL MOISTURE TRANSPORT OFF THE ATLANTIC. HAVE CONTINUED TO
ADVERTISE A RETURN OF SLIGHT TO LOW END CHANCE POPS FOR PORTIONS
OF THE AREA...MAINLY FOR DIURNALLY DRIVEN CONVECTION. NO OTHER
CLEAR FORCING MECHANISM LOOKS TO BE PRESENT SO NOT EXPECTING
ANYTHING WIDESPREAD AND RATHER STAGNANT AIRMASS IN PLACE SO
DEVELOPMENT SHOULD BE TYPICAL SUMMERTIME OUTFLOW DRIVEN. TEMPS
SHOULD BE SLIGHTLY WARMER THAN MIDWEEK BUT CLOSE TO NORMAL OR
SLIGHTLY BELOW WITH ENHANCED CLOUD COVERAGE.
BAKER
&&
.AVIATION...
06Z UPDATE...
HIGH RES MODELS ARE BRINGING IN PRECIP A LITTLE EARLIER THAN
PREVIOUS RUNS. HAVE PUSHED BACK THE PROB GROUP A COUPLE OF
HOURS. CIGS AROUND 045 DURING THE AFTERNOON. MODEL SOUNDINGS ARE
ALSO SHOWING SOME POTENTIAL FOR MVFR CIGS OVERNIGHT.
//ATL CONFIDENCE...06Z UPDATE...
MED CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 72 89 71 / 40 40 30 30
ATLANTA 90 74 88 72 / 40 40 30 20
BLAIRSVILLE 84 67 83 63 / 60 40 30 10
CARTERSVILLE 90 71 88 68 / 60 40 30 20
COLUMBUS 93 76 91 74 / 40 30 40 40
GAINESVILLE 87 72 87 71 / 60 40 30 20
MACON 92 74 90 73 / 40 30 40 40
ROME 91 72 89 68 / 60 40 30 10
PEACHTREE CITY 91 72 89 70 / 40 30 30 30
VIDALIA 92 73 92 74 / 30 20 40 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....BAKER
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
509 PM CDT MON AUG 10 2015
.MESOSCALE DISCUSSION...
349 PM CDT
THREE LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE TO TRACK
SOUTHWARD FROM CENTRAL WISCONSIN TO NORTHERN ILLINOIS. THE FIRST
LINE...NOW EXTENDING FROM LONG POINT TO DE MOTTE...HAS LOST MUCH OF
ITS STRENGTH AS THE OUTFLOW BOUNDARY HAS OUTRUN THE MAIN LINE OF
STORMS. THIS OUTFLOW HAS SHOWN GUSTS OF 25KT AT IKK WITH SIMILAR
VALUES EXPECTED FOR THE REMAINDER OF ITS LIFE IN THE CWA. SINCE THIS
LINE HAS THE MOST UNTAPPED INSTABILITY TO WORK WITH...A FEW GIRTHY
YET SUB-SEVERE STORMS ARE POSSIBLE.
THE MIDDLE LINE OF STORM EXTENDING FROM BUFFALO TO NORTH CHICAGO IS
CURRENTLY SHOWING THE MOST UPWARD GROWTH AND OUTFLOW INTERACTIONS.
DOPPLER RADAR SHOWS NUMEROUS OUTFLOW WAVES FROM MULTIPLE PREVIOUS
STORMS. THESE INTERACTIONS CAN ACT TO CREATE LOW LEVEL WIND SHEAR
AND MAY PROMPT BRIEF FUNNEL CLOUD DEVELOPMENT. ONE CELL IN
PARTICULAR FROM CAROL STREAM HEADED SOUTH TOWARD DOWNERS GROVE HAS
SHOWN NEARLY 60 DBZ OF REFLECTIVITY ABOVE THE -20C LINE. 1 INCH HAIL
IS NOT OUT OF THE QUESTION WITH CELLS SIMILAR TO THIS OVER THE NEXT
2-3 HOURS WHILE DAYTIME HEATING IS STILL ABUNDANT. EXPECT CONTINUED
INTERACTIONS TO ALSO FUEL CELL GROWTH. IN THIS REGIME...EVEN
VERTICALLY CHALLENGED CELLS MAY SHOW SIGNS OF BRIEF ROTATION...BUT
WIDESPREAD TORNADIC ACTIVITY IS NOT ANTICIPATED.
THE THIRD/NORTHERLY LINE MARKS A COLD FRONT WHERE DEWPOINT
TEMPERATURES DROP ROUGHLY 10 DEGREES. THIS LINE HAS THE MOST
SUFFICIENT FORCING MECHANISM...BUT LITTLE IN THE WAY OF INSTABILITY.
THE FRONT WILL BE HALFWAY ACROSS THE CWA BY 23Z (MENDOTA TO
PLAINFIELD TO GARY)...AT WHICH POINT THE LOSS OF DAYTIME HEATING IS
EXPECTED TO CEASE REMAINING THUNDER CHANCES. THIS IS SUPPORTED BY
THE EXPERIMENTAL HRRR THAT SUGGESTS ISOLATED LINGERING SHOWERS
THROUGH 00Z.
MM
&&
.SHORT TERM...
237 PM CDT
THROUGH TONIGHT...
A SERIES OF SHORTWAVE TROUGHS CONTINUE TO TRACK SOUTHEAST ACROSS THE
REGION GENERATING BANDS OF SHOWERS AND THUNDERSTORMS. THE FIRST WAVE
IS CROSSING FAR SOUTHERN LAKE MICHIGAN PUSHING A BAND OF SHOWERS AND
STORMS SOUTHWARD ALONG THE I-80 CORRIDOR AT THIS TIME WITH ANOTHER
CLUSTER OUT OVER LAKE MICHIGAN. WITH THE MOVEMENT OF THE WAVE
HAVING AN EASTWARD COMPONENT THE BETTER LARGER SCALE FORCING WILL
BE SHIFTING AWAY FROM THE CURRENT BAND OF ACTIVITY ALONG I-80 SO
THIS AREA MAY START TO FADE IN COVERAGE OVER THE NEXT COUPLE HOURS.
IN ADDITION...OUTFLOW IS NOW OUTRUNNING THE CONVECTION SUPPORTING A
DOWNWARD TREND. HOWEVER...WITH AN UNSTABLE AIRMASS IN PLACE THE
OUTFLOW MAY GENERATE NEW STORMS SOUTH OF I-80 BUT THE EXITING OF THE
UPPER FORCING SUGGESTS MORE ISOLATED COVERAGE TO ANYTHING
ADDITIONAL. AREAS OF NORTHWEST INDIANA PROBABLY HAVE THE BEST CHANCE
FOR RENEWED DEVELOPMENT FROM THIS FIRST WAVE THROUGH LATE AFTERNOON.
ATTENTION TURNS TO A SECOND WAVE TRACKING ACROSS CENTRAL WISCONSIN
WHICH IS GENERATING SCATTERED CONVECTION ACROSS MUCH OF SOUTHERN
WISCONSIN. THIS ACTIVITY IS MORE DISJOINTED IN COVERAGE BUT WILL
LIKELY CONTINUE INTO NORTHERN ILLINOIS INTO LATE AFTERNOON...WITH
ADDITIONAL DEVELOPMENT ACROSS NORTHERN ILLINOIS IN THE MEANTIME.
STORM ORGANIZATION WILL LIKELY BE A BIGGER CHALLENGE NORTH OF I-80
GIVEN THE PREVIOUS ACTIVITY BUT SOME BRIEF PULSING OF UPDRAFTS MAY
PRODUCE SOME SMALL HAIL AND SOME SUB SEVERE WIND GUSTS. A SUBTLE
COOL FRONTAL BOUNDARY WILL BRING A PUSH OF DRIER AIR INTO THE AREA
EARLY THIS EVENING AS THE UPPER WAVE EXITS. THIS WILL BRING AN END
TO ANY CONVECTION. WILL KEEP A MINIMAL CHANCE FOR POPS VERY EARLY
THIS EVENING. OTHERWISE DRY WEATHER IS EXPECT TONIGHT. CANNOT RULE
OUT SOME PATCHY FOG LATE ACROSS SOUTHERN AREAS WHERE WINDS WILL BE
LIGHTEST BUT THERE MAY BE ENOUGH OF A BREEZE TO MITIGATE ANY
DEVELOPMENT. FURTHER NORTH...DECREASING DEWPOINTS AND A SLIGHT
BREEZE SHOULD FURTHER REDUCE THE CHANCE FOR FOG DEVELOPMENT.
MDB
&&
.LONG TERM...
TUESDAY THROUGH MONDAY...
306 PM...MAIN FORECAST CONCERN IS PRECIP CHANCES THURSDAY NIGHT
THRU FRIDAY NIGHT AND AGAIN SUNDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD ACROSS THE REGION TUESDAY AND TUESDAY NIGHT
AND THEN SLOWLY SAG SOUTHEAST OF THE AREA WEDNESDAY NIGHT INTO
THURSDAY. THIS WILL PROVIDE DRY WEATHER WITH NORTHEAST WINDS OFF THE
LAKE TUESDAY AND THEN A LAKE BREEZE WEDNESDAY...KEEPING AREAS NEAR
THE LAKE A FEW DEGREES COOLER BUT WITH MOSTLY SUNNY SKIES...TEMPS
INLAND SHOULD REACH AROUND 80 BOTH DAYS.
WINDS TURN SOUTHWESTERLY WEDNESDAY NIGHT AS THE LOW LEVELS BEGIN TO
WARM SOME OVERNIGHT. NOT SURE HOW LOW TEMPS WILL DROP NOW WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH THIS WARMING ALOFT. STILL POSSIBLE
FOR SOME MID/UPPER 50S LOW TEMPS AWAY FROM URBAN AREAS AND PERHAPS
MOST LIKELY INTO NORTHWEST INDIANA. THURSDAY LOOKING TO BE A BREEZY
WARM DAY AS HIGHS REBOUND BACK INTO THE MID 80S.
AN UPPER LEVEL WAVE IS EXPECTED TO MOVE ACROSS THE WESTERN LAKES
REGION THURSDAY NIGHT INTO FRIDAY WHICH WILL BE THE NEXT CHANCE FOR
SHOWERS/THUNDERSTORMS. OVERALL CONFIDENCE IS SOMEWHAT LOW REGARDING
COVERAGE/TIMING BUT CHANCE POPS INTO FRIDAY EVENING LOOK REASONABLE.
WINDS WILL LIKELY TURN OFF THE LAKE POSSIBLY FRIDAY AFTERNOON BUT
ESPECIALLY ON SATURDAY.
THE UPPER RIDGE BUILDS BACK INTO THE REGION SUNDAY INTO MONDAY.
TEMPS WILL LIKELY RISE BACK INTO THE MID...PERHAPS UPPER 80S DURING
THIS TIME PERIOD WITH A STRONGER COLD FRONT MOVING SOUTH INTO THE
UPPER MIDWEST/NORTHERN LAKES REGION SUNDAY/SUNDAY NIGHT. STILL
TIMING DIFFERENCES WITH HOW FAST THIS FRONT MOVES SOUTH ACROSS THE
AREA EARLY NEXT WEEK. OUTSIDE OF ANY LAKE COOLING...APPEARS HIGHS
IN THE MID 80...PERHAPS UPPER 80S...IS ON TRACK FROM THURSDAY
UNTIL THIS FRONT ARRIVES EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* ISOLATED SHRA NEXT 2-3 HOURS...THOUGH TSRA COVERAGE DECREASING
VCNTY ORD/MDW AND BECOMING FOCUSED MAINLY SOUTH-SOUTHWEST OF
THE TERMINALS.
* NORTHERLY WINDS AT OR BELOW 10 KTS...THOUGH DIRECTION VARIABLE
AT TIMES INTO EARLY EVENING WITH SHRA OUTFLOW.
* LAKE BREEZE DEVELOPMENT TUESDAY AFTERNOON.
MM/RATZER
//DISCUSSION...UPDATED 18Z...
LINE OF THUNDERSTORMS ALONG A NOW DEFINED BOUNDARY CONTINUES TO
SWEEP ACROSS THE CHICAGO TERMINALS EARLY THIS AFTERNOON. MAIN
CELLS APPEAR TO MISS ORD AND MDW...WITH VICINITY THUNDER COVERING
THIS FEATURE. SECOND BOUNDARY APPEARS TO ENTER THE AIRSPACE AROUND
20Z AS NOTED IN WEAK RADAR RETURNS IN CENTRAL WISCONSIN. THE
INITIAL LINE SHOULD LOWER INSTABILITY...LEAVING LESS ENERGY FOR
THE SECOND BOUNDARY TO TAP INTO. HAVE LEFT VCSH IN THE TAF WITH NO
MENTION OF THUNDER. FORECAST SOUNDINGS STILL SHOW LAPSE RATES
IN THE 8-10 C/KM RANGE WITH CONVECTIVE TEMPS OF 80F...SO THUNDER IS
NOT COMPLETELY OUT OF THE QUESTION IN THE 20-23Z TIMEFRAME.
BEHIND THE BOUNDARY...MAINLY VFR CONDITIONS ARE LIKELY FOR AN
EXTENDED PERIOD OF TIME. WHILE OUTLYING AREAS MAY SEE PATCHY AM
FOG...THE CHICAGO TERMINALS SHOULD STAY VFR. THE FOLLOWING FEW
DAYS WILL ALLOW FOR LAKE BREEZE CHANCES GENERALLY INITIALIZING IN
THE 19-22Z TIMEFRAME.
MM
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* HIGH FOR SHRA/TSRA TRENDS INTO THIS EVENING.
* MEDIUM-HIGH IN WIND DIRECTION THIS EVENING.
* MEDIUM FOR LAKE BREEZE TUESDAY.
MM/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR. NNE WINDS ABOVE 10 KT.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS.
SUNDAY...VFR. SOUTH-SOUTHWEST WINDS.
KMD
&&
.MARINE...
306 PM...LOW PRESSURE OVER THE SOUTHERN LAKES THIS AFTERNOON WILL
MOVE TO NEAR LAKE ONTARIO TUESDAY MORNING AS IT SLOWLY DEEPENS.
THIS LOW WILL THEN ABSORB ANOTHER LOW OVER NORTHERN QUEBEC ON
TUESDAY. THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES
BETWEEN THIS LOW AND HIGH PRESSURE OVER THE PLAINS WHICH WILL
BUILD SOUTHEAST TUESDAY INTO WEDNESDAY. NORTHERLY WINDS WILL
INCREASE TO 15-25KTS LATER TONIGHT AND CONTINUE INTO TUESDAY
EVENING...BEFORE DIMINISHING TUESDAY NIGHT INTO WEDNESDAY MORNING
AS THE HIGH APPROACHES.
LOW PRESSURE WILL MOVE ACROSS ONTARIO THURSDAY AS THE HIGH REMAINS
OVER THE OHIO VALLEY AND THIS WILL TIGHTEN GRADIENT ACROSS LAKE
MICHIGAN THURSDAY INTO THURSDAY NIGHT WITH SOUTHWEST WINDS PERHAPS
AS HIGH AS 15-25 KT WHICH WILL THEN DIMINISH LATER THURSDAY NIGHT
INTO FRIDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 7 AM
WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
350 PM CDT MON AUG 10 2015
.MESOSCALE DISCUSSION...
349 PM CDT
THREE LINES OF SHOWERS WITH EMBEDDED THUNDERSTORMS CONTINUE TO TRACK
SOUTHWARD FROM CENTRAL WISCONSIN TO NORTHERN ILLINOIS. THE FIRST
LINE...NOW EXTENDING FROM LONG POINT TO DE MOTTE...HAS LOST MUCH OF
ITS STRENGTH AS THE OUTFLOW BOUNDARY HAS OUTRUN THE MAIN LINE OF
STORMS. THIS OUTFLOW HAS SHOWN GUSTS OF 25KT AT IKK WITH SIMILAR
VALUES EXPECTED FOR THE REMAINDER OF ITS LIFE IN THE CWA. SINCE THIS
LINE HAS THE MOST UNTAPPED INSTABILITY TO WORK WITH...A FEW GIRTHY
YET SUB-SEVERE STORMS ARE POSSIBLE.
THE MIDDLE LINE OF STORM EXTENDING FROM BUFFALO TO NORTH CHICAGO IS
CURRENTLY SHOWING THE MOST UPWARD GROWTH AND OUTFLOW INTERACTIONS.
DOPPLER RADAR SHOWS NUMEROUS OUTFLOW WAVES FROM MULTIPLE PREVIOUS
STORMS. THESE INTERACTIONS CAN ACT TO CREATE LOW LEVEL WIND SHEAR
AND MAY PROMPT BRIEF FUNNEL CLOUD DEVELOPMENT. ONE CELL IN
PARTICULAR FROM CAROL STREAM HEADED SOUTH TOWARD DOWNERS GROVE HAS
SHOWN NEARLY 60 DBZ OF REFLECTIVITY ABOVE THE -20C LINE. 1 INCH HAIL
IS NOT OUT OF THE QUESTION WITH CELLS SIMILAR TO THIS OVER THE NEXT
2-3 HOURS WHILE DAYTIME HEATING IS STILL ABUNDANT. EXPECT CONTINUED
INTERACTIONS TO ALSO FUEL CELL GROWTH. IN THIS REGIME...EVEN
VERTICALLY CHALLENGED CELLS MAY SHOW SIGNS OF BRIEF ROTATION...BUT
WIDESPREAD TORNADIC ACTIVITY IS NOT ANTICIPATED.
THE THIRD/NORTHERLY LINE MARKS A COLD FRONT WHERE DEWPOINT
TEMPERATURES DROP ROUGHLY 10 DEGREES. THIS LINE HAS THE MOST
SUFFICIENT FORCING MECHANISM...BUT LITTLE IN THE WAY OF INSTABILITY.
THE FRONT WILL BE HALFWAY ACROSS THE CWA BY 23Z (MENDOTA TO
PLAINFIELD TO GARY)...AT WHICH POINT THE LOSS OF DAYTIME HEATING IS
EXPECTED TO CEASE REMAINING THUNDER CHANCES. THIS IS SUPPORTED BY
THE EXPERIMENTAL HRRR THAT SUGGESTS ISOLATED LINGERING SHOWERS
THROUGH 00Z.
MM
&&
.SHORT TERM...
237 PM CDT
THROUGH TONIGHT...
A SERIES OF SHORTWAVE TROUGHS CONTINUE TO TRACK SOUTHEAST ACROSS THE
REGION GENERATING BANDS OF SHOWERS AND THUNDERSTORMS. THE FIRST WAVE
IS CROSSING FAR SOUTHERN LAKE MICHIGAN PUSHING A BAND OF SHOWERS AND
STORMS SOUTHWARD ALONG THE I-80 CORRIDOR AT THIS TIME WITH ANOTHER
CLUSTER OUT OVER LAKE MICHIGAN. WITH THE MOVEMENT OF THE WAVE
HAVING AN EASTWARD COMPONENT THE BETTER LARGER SCALE FORCING WILL
BE SHIFTING AWAY FROM THE CURRENT BAND OF ACTIVITY ALONG I-80 SO
THIS AREA MAY START TO FADE IN COVERAGE OVER THE NEXT COUPLE HOURS.
IN ADDITION...OUTFLOW IS NOW OUTRUNNING THE CONVECTION SUPPORTING A
DOWNWARD TREND. HOWEVER...WITH AN UNSTABLE AIRMASS IN PLACE THE
OUTFLOW MAY GENERATE NEW STORMS SOUTH OF I-80 BUT THE EXITING OF THE
UPPER FORCING SUGGESTS MORE ISOLATED COVERAGE TO ANYTHING
ADDITIONAL. AREAS OF NORTHWEST INDIANA PROBABLY HAVE THE BEST CHANCE
FOR RENEWED DEVELOPMENT FROM THIS FIRST WAVE THROUGH LATE AFTERNOON.
ATTENTION TURNS TO A SECOND WAVE TRACKING ACROSS CENTRAL WISCONSIN
WHICH IS GENERATING SCATTERED CONVECTION ACROSS MUCH OF SOUTHERN
WISCONSIN. THIS ACTIVITY IS MORE DISJOINTED IN COVERAGE BUT WILL
LIKELY CONTINUE INTO NORTHERN ILLINOIS INTO LATE AFTERNOON...WITH
ADDITIONAL DEVELOPMENT ACROSS NORTHERN ILLINOIS IN THE MEANTIME.
STORM ORGANIZATION WILL LIKELY BE A BIGGER CHALLENGE NORTH OF I-80
GIVEN THE PREVIOUS ACTIVITY BUT SOME BRIEF PULSING OF UPDRAFTS MAY
PRODUCE SOME SMALL HAIL AND SOME SUB SEVERE WIND GUSTS. A SUBTLE
COOL FRONTAL BOUNDARY WILL BRING A PUSH OF DRIER AIR INTO THE AREA
EARLY THIS EVENING AS THE UPPER WAVE EXITS. THIS WILL BRING AN END
TO ANY CONVECTION. WILL KEEP A MINIMAL CHANCE FOR POPS VERY EARLY
THIS EVENING. OTHERWISE DRY WEATHER IS EXPECT TONIGHT. CANNOT RULE
OUT SOME PATCHY FOG LATE ACROSS SOUTHERN AREAS WHERE WINDS WILL BE
LIGHTEST BUT THERE MAY BE ENOUGH OF A BREEZE TO MITIGATE ANY
DEVELOPMENT. FURTHER NORTH...DECREASING DEWPOINTS AND A SLIGHT
BREEZE SHOULD FURTHER REDUCE THE CHANCE FOR FOG DEVELOPMENT.
MDB
&&
.LONG TERM...
TUESDAY THROUGH MONDAY...
306 PM...MAIN FORECAST CONCERN IS PRECIP CHANCES THURSDAY NIGHT
THRU FRIDAY NIGHT AND AGAIN SUNDAY NIGHT INTO MONDAY.
HIGH PRESSURE WILL BUILD ACROSS THE REGION TUESDAY AND TUESDAY NIGHT
AND THEN SLOWLY SAG SOUTHEAST OF THE AREA WEDNESDAY NIGHT INTO
THURSDAY. THIS WILL PROVIDE DRY WEATHER WITH NORTHEAST WINDS OFF THE
LAKE TUESDAY AND THEN A LAKE BREEZE WEDNESDAY...KEEPING AREAS NEAR
THE LAKE A FEW DEGREES COOLER BUT WITH MOSTLY SUNNY SKIES...TEMPS
INLAND SHOULD REACH AROUND 80 BOTH DAYS.
WINDS TURN SOUTHWESTERLY WEDNESDAY NIGHT AS THE LOW LEVELS BEGIN TO
WARM SOME OVERNIGHT. NOT SURE HOW LOW TEMPS WILL DROP NOW WEDNESDAY
NIGHT INTO THURSDAY MORNING WITH THIS WARMING ALOFT. STILL POSSIBLE
FOR SOME MID/UPPER 50S LOW TEMPS AWAY FROM URBAN AREAS AND PERHAPS
MOST LIKELY INTO NORTHWEST INDIANA. THURSDAY LOOKING TO BE A BREEZY
WARM DAY AS HIGHS REBOUND BACK INTO THE MID 80S.
AN UPPER LEVEL WAVE IS EXPECTED TO MOVE ACROSS THE WESTERN LAKES
REGION THURSDAY NIGHT INTO FRIDAY WHICH WILL BE THE NEXT CHANCE FOR
SHOWERS/THUNDERSTORMS. OVERALL CONFIDENCE IS SOMEWHAT LOW REGARDING
COVERAGE/TIMING BUT CHANCE POPS INTO FRIDAY EVENING LOOK REASONABLE.
WINDS WILL LIKELY TURN OFF THE LAKE POSSIBLY FRIDAY AFTERNOON BUT
ESPECIALLY ON SATURDAY.
THE UPPER RIDGE BUILDS BACK INTO THE REGION SUNDAY INTO MONDAY.
TEMPS WILL LIKELY RISE BACK INTO THE MID...PERHAPS UPPER 80S DURING
THIS TIME PERIOD WITH A STRONGER COLD FRONT MOVING SOUTH INTO THE
UPPER MIDWEST/NORTHERN LAKES REGION SUNDAY/SUNDAY NIGHT. STILL
TIMING DIFFERENCES WITH HOW FAST THIS FRONT MOVES SOUTH ACROSS THE
AREA EARLY NEXT WEEK. OUTSIDE OF ANY LAKE COOLING...APPEARS HIGHS
IN THE MID 80...PERHAPS UPPER 80S...IS ON TRACK FROM THURSDAY
UNTIL THIS FRONT ARRIVES EARLY NEXT WEEK. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* THUNDER FOR 1 HOUR AND SHRA MOVING THROUGH TERMINALS CURRENTLY.
* NORTH TO NORTHEAST WINDS GENERALLY UNDER 9KT TODAY...EXCEPT
BRIEF NORTHEAST GUSTS TO 20KT.
* LAKE BREEZE DEVELOPMENT TUESDAY AFTERNOON.
MM
//DISCUSSION...UPDATED 18Z...
LINE OF THUNDERSTORMS ALONG A NOW DEFINED BOUNDARY CONTINUES TO
SWEEP ACROSS THE CHICAGO TERMINALS EARLY THIS AFTERNOON. MAIN
CELLS APPEAR TO MISS ORD AND MDW...WITH VICINITY THUNDER COVERING
THIS FEATURE. SECOND BOUNDARY APPEARS TO ENTER THE AIRSPACE AROUND
20Z AS NOTED IN WEAK RADAR RETURNS IN CENTRAL WISCONSIN. THE
INITIAL LINE SHOULD LOWER INSTABILITY...LEAVING LESS ENERGY FOR
THE SECOND BOUNDARY TO TAP INTO. HAVE LEFT VCSH IN THE TAF WITH NO
MENTION OF THUNDER. FORECAST SOUNDINGS STILL SHOW LAPSE RATES
IN THE 8-10 C/KM RANGE WITH CONVECTIVE TEMPS OF 80F...SO THUNDER IS
NOT COMPLETELY OUT OF THE QUESTION IN THE 20-23Z TIMEFRAME.
BEHIND THE BOUNDARY...MAINLY VFR CONDITIONS ARE LIKELY FOR AN
EXTENDED PERIOD OF TIME. WHILE OUTLYING AREAS MAY SEE PATCHY AM
FOG...THE CHICAGO TERMINALS SHOULD STAY VFR. THE FOLLOWING FEW
DAYS WILL ALLOW FOR LAKE BREEZE CHANCES GENERALLY INITIALIZING IN
THE 19-22Z TIMEFRAME.
MM
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH FOR SHRA AND MEDIUM HIGH FOR THUNDER.
* HIGH FOR WINDS TODAY.
* MEDIUM FOR LAKE BREEZE TUESDAY.
MM
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT AND WEDNESDAY...VFR. NNE WINDS ABOVE 10 KT.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. EAST WINDS.
SUNDAY...VFR. SOUTH-SOUTHWEST WINDS.
KMD
&&
.MARINE...
306 PM...LOW PRESSURE OVER THE SOUTHERN LAKES THIS AFTERNOON WILL
MOVE TO NEAR LAKE ONTARIO TUESDAY MORNING AS IT SLOWLY DEEPENS.
THIS LOW WILL THEN ABSORB ANOTHER LOW OVER NORTHERN QUEBEC ON
TUESDAY. THE GRADIENT WILL TIGHTEN ACROSS THE WESTERN LAKES
BETWEEN THIS LOW AND HIGH PRESSURE OVER THE PLAINS WHICH WILL
BUILD SOUTHEAST TUESDAY INTO WEDNESDAY. NORTHERLY WINDS WILL
INCREASE TO 15-25KTS LATER TONIGHT AND CONTINUE INTO TUESDAY
EVENING...BEFORE DIMINISHING TUESDAY NIGHT INTO WEDNESDAY MORNING
AS THE HIGH APPROACHES.
LOW PRESSURE WILL MOVE ACROSS ONTARIO THURSDAY AS THE HIGH REMAINS
OVER THE OHIO VALLEY AND THIS WILL TIGHTEN GRADIENT ACROSS LAKE
MICHIGAN THURSDAY INTO THURSDAY NIGHT WITH SOUTHWEST WINDS PERHAPS
AS HIGH AS 15-25 KT WHICH WILL THEN DIMINISH LATER THURSDAY NIGHT
INTO FRIDAY. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...BEACH HAZARDS STATEMENT...INZ001-INZ002...9 AM TUESDAY TO 7 AM
WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ743-LMZ744-LMZ745...9 AM TUESDAY TO 4
AM WEDNESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS LINCOLN IL
255 PM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT)
ISSUED AT 254 PM CDT MON AUG 10 2015
ISOLATED SHOWERS AND THUNDERSTORMS WILL OCCUR UNTIL SUNSET OVER
CENTRAL AND SOUTHEAST IL. A FRONTAL BOUNDARY ALONG A PARIS TO
CHARLESTON TO EFFINGHAM TO VANDALIA LINE WILL PUSH THROUGH SE IL
LATE THIS AFTERNOON GIVING ISOLATED CONVECTION THERE. MEANWHILE AN
UPPER LEVEL SHORT WAVE OVER SOUTHERN LAKE MI INTO NORTHERN IL WILL
PUSH INTO CENTRAL IL BY 00Z WITH THE BRUNT OF ITS LIFT PASSING NE OF
CENTRAL IL OVER NORTHERN HALF OF INDIANA INTO SOUTHERN LOWER MI.
SCATTERED SHOWERS AND THUNDERSTORMS OVER NORTHERN IL JUST NORTH OF
CWA WILL PUSH SE INTO THE IL RIVER VALLEY LATE THIS AFTERNOON AND
TOWARD I-72 EARLY THIS EVENING. CAPES PEAK FROM 1500-3000 J/KG THIS
AFTERNOON WITH BULK SHEAR OF 20-40 KTS. THIS COULD SUPPORT A FEW
STRONG THUNDERSTORMS FROM I-74 NE AND FROM I-70 SE UNTIL 00Z/7 PM.
WEAK HIGH PRESSURE BUILD ACROSS THE MIDWEST INTO TONIGHT AND NW
WINDS TO BRING IN SOMEWHAT COOLER AND LESS HUMID AIR. LOWS OVERNIGHT
IN MID 60S WITH SOME UPPER 60S SOUTH OF I-70. PATCHY SHALLOW GROUND
FOG POSSIBLE LATE TONIGHT SE OF THE IL RIVER AND MORE WIDESPREAD IN
AREAS EAST AND SOUTH OF CENTRAL IL.
&&
.LONG TERM...(TUESDAY THROUGH MONDAY)
ISSUED AT 254 PM CDT MON AUG 10 2015
SURFACE HIGH PRESSURE WILL BUILD INTO THE MIDWEST THROUGH MIDWEEK
WHILE NORTHWEST FLOW AFFECTS THE AREA BETWEEN UPPER LEVEL RIDGING
OVER THE ROCKIES/WESTERN PLAINS AND TROUGHING OVER THE EAST COAST.
RELATIVELY MILD TEMPERATURES AND LESS HUMIDITY WILL BE ASSOCIATED
WITH THIS PATTERN AND HIGHS ARE EXPECTED IN THE LOW TO MID 80S
TUESDAY THROUGH THURSDAY...WITH DEWPOINTS IN THE 60S. LOWS FROM
AROUND 60 TO 65 EXPECTED EACH NIGHT.
A WEAKENING COLD FRONT CONTINUES IN MODEL FORECASTS FOR FRIDAY. THE
BULK OF MODEL GUIDANCE DROPS THE FRONTAL BOUNDARY FROM THE GREAT
LAKES REGION SOUTHWARD...PRIMARILY THROUGH AREAS EAST OF ILLINOIS.
THE BOUNDARY COULD BE A FOCUS FOR SHOWERS AND THUNDERSTORMS IN
NORTHERN AND EAST CENTRAL IL FRIDAY AND FRIDAY NIGHT. VERY LITTLE
COLD AIR IS EXPECTED TO PUSH INTO CENTRAL IL...AND TEMPERATURES
SHOULD CONTINUE A SLOW CLIMB INTO THE MID AND UPPER 80S FRIDAY
THROUGH MONDAY. ANOTHER COLD FRONT COULD POTENTIALLY AFFECT THE AREA
EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON AUG 10 2015
A FRONTAL BOUNDARY SOUTH OF I-72 WILL PUSH INTO SOUTHEAST IL
DURING THIS AFTERNOON WITH NW WIND 5-10 KTS BEHIND THIS BOUNDARY
OVER CENTRAL IL AIRPORTS. ISOLATED CONVECTION STARTED TO
DEVELOPING ALONG THIS BOUNDARY WHICH HAS MISSED THE CENTRAL IL
TAF SITES. AN UPPER LEVEL TROF OVER SE WI AND NW IL WILL MOVE
INTO THE IL RIVER VALLEY LATE THIS AFTERNOON. SCATTERED CONVECTION
OVER NORTHERN IL NORTH OF I-80 WILL SPREAD SE AT 30 MPH TOWARD PIA
BY 20Z AND BMI AND POSSIBLY CMI BETWEEN 21-22Z AS IT BECOMES MORE
ISOLATED. SO CARRIED VCTS/VCSH TO ADDRESS THIS CHANCE WITH MVFR
CEILINGS POSSIBLE AT TIMES THIS AFTERNOON. ISOLATED CONVECTION
SHOULD END BY SUNSET LEAVING MOSTLY CLEAR SKIES AND LIGHT NW WINDS
TONIGHT. HAVE 3-5 MILES FOG FROM 09Z-14Z WHILE MORE WIDESPREAD
AND DENSER FOG TO OCCUR NE OF CMI OVER INDIANA AND NE IL AND SW
OF SPI OVER SW IL INTO MO AND WESTERN KY PER HRRR MODEL VSBY
FORECAST THRU 07Z. WINDS TO BE NORTH 5-9 KTS AFTER 14Z TUE
MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...ONTON
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
101 PM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT MON AUG 10 2015
UPDATED THE FORECAST DURING MID MORNING WITH DENSE FOG ADVISORY
ENDING AT 9 AM ACROSS NORTHERN HALF OF CWA. WILL ISSUE ANOTHER
UPDATE LATE THIS MORNING TO REMOVE MENTION OF PATCHY FOG THIS
MORNING. OTHERWISE REST OF FORECAST LOOKS ON TRACK THIS AFTERNOON.
HAVE 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS
WARM AND HUMID CONDITIONS PREVAIL WITH DEWPOINTS OF 70-75F AND
SEASONABLE HIGHS IN THE LOW TO MID 80S. A WEAK FRONTAL BOUNDARY
JUST SE OF A RANTOUL TO DECATUR TO TAYLORVILLE LINE WILL PUSH SE
ACROSS SOUTHEAST IL DURING THIS AFTERNOON GIVING ISOLATED SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF IT WHERE UNSTABLE AIRMASS
WITH CAPES OF 1500-2500 J/KG. MEANWHILE A SHORT WAVE TROF OVER SE
WI INTO IA WILL SHIFT SE INTO THE IL RIVER VALLEY LATER THIS
AFTEROON GIVING A CHANCE OF SHOWERS/THUNDESTORMS THERE AS WELL.
SPC KEEPS MARGINAL RISK OF SEVERE STORMS SE OF CWA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1258 PM CDT MON AUG 10 2015
A FRONTAL BOUNDARY SOUTH OF I-72 WILL PUSH INTO SOUTHEAST IL
DURING THIS AFTERNOON WITH NW WIND 5-10 KTS BEHIND THIS BOUNDARY
OVER CENTRAL IL AIRPORTS. ISOLATED CONVECTION STARTED TO
DEVELOPING ALONG THIS BOUNDARY WHICH HAS MISSED THE CENTRAL IL
TAF SITES. AN UPPER LEVEL TROF OVER SE WI AND NW IL WILL MOVE
INTO THE IL RIVER VALLEY LATE THIS AFTERNOON. SCATTERED CONVECTION
OVER NORTHERN IL NORTH OF I-80 WILL SPREAD SE AT 30 MPH TOWARD PIA
BY 20Z AND BMI AND POSSIBLY CMI BETWEEN 21-22Z AS IT BECOMES MORE
ISOLATED. SO CARRIED VCTS/VCSH TO ADDRESS THIS CHANCE WITH MVFR
CEILINGS POSSIBLE AT TIMES THIS AFTERNOON. ISOLATED CONVECTION
SHOULD END BY SUNSET LEAVING MOSTLY CLEAR SKIES AND LIGHT NW WINDS
TONIGHT. HAVE 3-5 MILES FOG FROM 09Z-14Z WHILE MORE WIDESPREAD
AND DENSER FOG TO OCCUR NE OF CMI OVER INDIANA AND NE IL AND SW
OF SPI OVER SW IL INTO MO AND WESTERN KY PER HRRR MODEL VSBY
FORECAST THRU 07Z. WINDS TO BE NORTH 5-9 KTS AFTER 14Z TUE
MORNING.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...07
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1045 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 AM CDT MON AUG 10 2015
UPDATED THE FORECAST DURING MID MORNING WITH DENSE FOG ADVISORY
ENDING AT 9 AM ACROSS NORTHERN HALF OF CWA. WILL ISSUE ANOTHER
UPDATE LATE THIS MORNING TO REMOVE MENTION OF PATCHY FOG THIS
MORNING. OTHERWISE REST OF FORECAST LOOKS ON TRACK THIS AFTERNOON.
HAVE 20-30% CHANCE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON AS
WARM AND HUMID CONDITIONS PREVAIL WITH DEWPOINTS OF 70-75F AND
SEASONABLE HIGHS IN THE LOW TO MID 80S. A WEAK FRONTAL BOUNDARY
JUST SE OF A RANTOUL TO DECATUR TO TAYLORVILLE LINE WILL PUSH SE
ACROSS SOUTHEAST IL DURING THIS AFTERNOON GIVING ISOLATED SHOWERS
AND THUNDERSTORMS ALONG AND AHEAD OF IT WHERE UNSTABLE AIRMASS
WITH CAPES OF 1500-2500 J/KG. MEANWHILE A SHORT WAVE TROF OVER SE
WI INTO IA WILL SHIFT SE INTO THE IL RIVER VALLEY LATER THIS
AFTEROON GIVING A CHANCE OF SHOWERS/THUNDESTORMS THERE AS WELL.
SPC KEEPS MARGINAL RISK OF SEVERE STORMS SE OF CWA THIS AFTERNOON.
&&
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 657 AM CDT MON AUG 10 2015
MAIN CONCERN INITIALLY WILL BE CIGS AND VSBYS IN DENSE FOG. VLIFR
AND LIFR CONDITIONS WILL AFFECT ALL BUT BMI INITIALLY, WHERE IFR
CONDITIONS PREVAIL AT 12Z. FORECAST SOUNDINGS SHOW WELL SATURATED
SURFACE LAYER AND INVERSION, SO FOG MAY LINGER FOR SEVERAL HOURS
AFTER SUNRISE. FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z THIS
MORNING WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY LATE
MORNING. SCATTERED TO BROKEN CUMULUS SHOULD REMAIN IN THE
AFTERNOON WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS
WILL BECOME NORTH-NORTHWEST THIS MORNING AT 8 TO 13 KTS.
SPOTTY SHOWERS AND STORMS MAY DEVELOP THIS AFTERNOON INTO EARLY
EVENING ALONG A TROUGH OF LOW PRESSURE PASSING FROM NW TO SE
ACROSS THE AREA. HRRR AND RAP MODELS FOCUS CHANCES MAINLY FROM PIA
AND NW 21Z-01Z, THEN DISSIPATE THE LINE OF SHOWERS. FOR NOW, WILL
USE VCSH FOR PIA AND KEEP THE OTHER TAF SITES DRY.
ANOTHER ROUND OF FOG COULD DEVELOP LATE TONIGHT, SO WE ADDED MVFR
FOG ACROSS THE BOARD AFTER 11/09Z TO TREND IN THAT DIRECTION.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...07
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
658 AM CDT MON AUG 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VSBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE
PAST HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL
DENSE FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY
DENSE OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 657 AM CDT MON AUG 10 2015
MAIN CONCERN INITIALLY WILL BE CIGS AND VSBYS IN DENSE FOG. VLIFR
AND LIFR CONDITIONS WILL AFFECT ALL BUT BMI INITIALLY, WHERE IFR
CONDITIONS PREVAIL AT 12Z. FORECAST SOUNDINGS SHOW WELL SATURATED
SURFACE LAYER AND INVERSION, SO FOG MAY LINGER FOR SEVERAL HOURS
AFTER SUNRISE. FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z THIS
MORNING WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY LATE
MORNING. SCATTERED TO BROKEN CUMULUS SHOULD REMAIN IN THE
AFTERNOON WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS
WILL BECOME NORTH-NORTHWEST THIS MORNING AT 8 TO 13 KTS.
SPOTTY SHOWERS AND STORMS MAY DEVELOP THIS AFTERNOON INTO EARLY
EVENING ALONG A TROUGH OF LOW PRESSURE PASSING FROM NW TO SE
ACROSS THE AREA. HRRR AND RAP MODELS FOCUS CHANCES MAINLY FROM PIA
AND NW 21Z-01Z, THEN DISSIPATE THE LINE OF SHOWERS. FOR NOW, WILL
USE VCSH FOR PIA AND KEEP THE OTHER TAF SITES DRY.
ANOTHER ROUND OF FOG COULD DEVELOP LATE TONIGHT, SO WE ADDED MVFR
FOG ACROSS THE BOARD AFTER 11/09Z TO TREND IN THAT DIRECTION.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 8 AM CDT THIS MORNING FOR ILZ027>031-
036>038-041>043-045>051.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SHIMON
AREA FORECAST DISCUSSION
NWS LINCOLN IL
305 AM CDT MON AUG 10 2015
.SHORT TERM...(TODAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
07Z/2AM SURFACE ANALYSIS SHOWS A 1010MB LOW OVER CENTRAL
ILLINOIS...WITH A FRONTAL BOUNDARY EXTENDING SOUTHWESTWARD INTO THE
OZARKS. A LARGE CLUSTER OF THUNDERSTORMS THAT DEVELOPED ALONG AN
OLD OUTFLOW BOUNDARY IS ONGOING WELL SOUTH OF THE FRONT ACROSS
SOUTHERN MISSOURI INTO FAR SOUTHERN ILLINOIS...HOWEVER THESE STORMS
ARE DROPPING SOUTHWARD AWAY FROM THE KILX CWA. MEANWHILE...ANOTHER
WEAK FRONT IS ANALYZED ACROSS CENTRAL IOWA WHERE A SECOND CLUSTER OF
SHOWERS AND THUNDERSTORMS IS LOCATED. HRRR SUGGESTS THESE STORMS
WILL WEAKEN AS THEY TRACK SLOWLY EASTWARD AND WILL NEVER REACH
CENTRAL ILLINOIS. RAPIDLY WARMING CLOUD TOPS ON LATEST IR SATELLITE
IMAGERY SUPPORT THIS THEORY...SO HAVE MAINTAINED A DRY FORECAST
ACROSS THE ENTIRE AREA EARLY THIS MORNING. MAIN CONCERN EARLY ON
WILL BE AREAS OF FOG THANKS TO AMPLE LOW-LEVEL MOISTURE...LIGHT
WINDS...AND BREAKS IN THE OVERCAST. VISBYS HAVE OCCASIONALLY
DROPPED TO AROUND 1/4 MILE ACROSS THE FAR NORTHERN CWA OVER THE PAST
HOUR...SO WILL NEED TO MONITOR TRENDS CLOSELY FOR POTENTIAL DENSE
FOG ADVISORY. AT THIS POINT...FOG HAS NOT BEEN CONSISTENTLY DENSE
OR WIDESPREAD...SO WILL HOLD OFF ON AN ADVISORY.
AS THE IOWA FRONT SAGS SOUTHEASTWARD...A FEW SHOWERS AND
THUNDERSTORMS WILL DEVELOP THIS AFTERNOON DURING PEAK HEATING. WITH
SURFACE DEWPOINTS REMAINING IN THE LOWER TO MIDDLE 70S...SBCAPE
VALUES WILL REACH THE 1500 TO 2500J/KG RANGE. WEAK CONVERGENCE
ALONG THE FRONT WILL BE ENOUGH TO TRIGGER WIDELY SCATTERED
CONVECTION...PARTICULARLY ACROSS THE CENTRAL/NORTHERN CWA IN
CLOSER PROXIMITY TO THE BOUNDARY. WILL CARRY 30 POPS ACROSS THIS
AREA...TAPERING DOWN TO 20S ALONG/SOUTH OF I-70.
&&
.LONG TERM...(TONIGHT THROUGH SUNDAY)
ISSUED AT 305 AM CDT MON AUG 10 2015
ANY LINGERING SHOWERS/THUNDERSTORMS WILL QUICKLY DISSIPATE AFTER
SUNSET AS DAYTIME INSTABILITY WANES. HAVE THEREFORE INCLUDED A 20
POP ACROSS THE BOARD THROUGH MID-EVENING...THEN HAVE GONE DRY
OVERNIGHT. COOLER/LESS HUMID AIR WILL GRADUALLY TRICKLE SOUTHWARD
INTO THE AREA TONIGHT THROUGH THURSDAY AS HIGH PRESSURE BUILDS INTO
THE REGION. AFTERNOON HIGHS WILL BE IN THE LOWER TO MIDDLE 80S
WHILE OVERNIGHT LOWS DROP INTO THE UPPER 50S AND LOWER 60S EACH DAY.
AFTER THAT...MODELS CONTINUE TO ADVERTISE A WEAKENING COLD FRONT
DROPPING INTO THE REGION LATE IN THE WEEK. BOTH THE GFS AND ECMWF
ARE SLIGHTLY SLOWER WITH THE BOUNDARY THAN IN PRIOR RUNS...WITH THE
FRONT REMAINING ACROSS NORTHERN ILLINOIS UNTIL FRIDAY
NIGHT/SATURDAY. WITH PRONOUNCED UPPER RIDGE INITIALLY POSITIONED
OVER THE PLAINS/SOUTHERN CANADA BUILDING EASTWARD...RISING UPPER
HEIGHTS WILL CREATE AN UNFAVORABLE ENVIRONMENT FOR THE ALREADY WEAK
FRONT. AS SUCH...BOTH MODELS SUGGEST IT WILL COMPLETELY DISSIPATE
BEFORE PASSING THROUGH CENTRAL ILLINOIS. HAVE MAINTAINED JUST A
SLIGHT CHANCE POP ALONG/NORTH OF I-74 ON FRIDAY IN CASE BOUNDARY CAN
GET CLOSE ENOUGH TO TRIGGER ISOLATED STORMS...THEN HAVE RETURNED TO
A DRY FORECAST FRIDAY NIGHT THROUGH SUNDAY AS FRONT WASHES OUT.
TEMPERATURES OVER THE WEEKEND WILL CLIMB BACK INTO THE UPPER 80S TO
AROUND 90 BEFORE THE NEXT FRONT POTENTIALLY COMES INTO THE PICTURE
BY NEXT MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CDT SUN AUG 9 2015
MAIN FORECAST CONCERN WILL BE CIGS AND VSBYS OVERNIGHT AS FOG
BECOMES MORE WIDESPREAD. OVERALL...LITTLE CHANGE IN THINKING
FROM EARLIER THIS EVENING. WIDELY SCATTERED SHOWERS WERE NOTED
ALONG THE I-74 CORRIDOR WITH ANOTHER AREA OF SHOWERS AND STORMS
SOUTH OF I-70. LATEST SURFACE ANALYSIS AND SURFACE OBSERVATIONS
TO OUR WEST AND NORTHWEST STILL INDICATES SOME CLOUD COVER WHICH
MAY PREVENT THE FOG FROM BECOMING TO WIDESPREAD EARLY MONDAY
MORNING. HOWEVER...WE DO SEE SOME SIZEABLE BREAKS IN THE OVERCAST
AS WELL SO ANY PROLONGED PERIOD OF CLEAR SKIES WILL LEAD TO SOME
LOCALLY DENSE (IFR OR VLIFR CONDITIONS) FOG FOR A TIME EARLY
MONDAY MORNING. THE FOG SHOULD BEGIN TO DISSIPATE BETWEEN 13-15Z
MONDAY WITH CIGS GRADUALLY LIFTING TO LOW VFR CONDITIONS BY
LATE MORNING WITH SCATTERED TO BROKEN CUMULUS IN THE AFTERNOON
WITH BASES IN THE 3000-4000 FOOT RANGE. SURFACE WINDS WILL BE
LIGHT AND VARIABLE TONIGHT AND THEN SWING INTO THE NORTHWEST
TO NORTH MONDAY MORNING AT 10 TO 15 KTS.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARNES
LONG TERM...BARNES
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 AM CDT MON AUG 10 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR OVERNIGHT. A FEW
SPOTTY SHOWERS POSSIBLE. IMPROVEMENT FROM IFR/MVFR EXPECTED
DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* SCATTERED TSRA MONDAY AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
A FEW LOW TOPPED SHOWERS IN COOK COUNTY AND OVER THE LAKE IN MOIST
SW FLOW ATOP A LINGERING ELEVATED FRONT. CARRYING A VCSH FOR THESE
FOR THE NEXT FEW HOURS BUT SHOULD BE LOW IMPACT.
OVERNIGHT CONCERN FOCUSES ON CEILING AND VISIBILITY.
DETERIORATION OF CONDITIONS HAD BEEN SLOW GOING BUT THE DOWNWARD
TREND IS PICKING UP QUICKLY...ESPECIALLY IN OUTLYING AREAS WHERE
SOME CLEARING SKIES HAVE ALLOWED CIGS AND VIS TO DROP INTO IFR AND
EVEN LIFR. EXPECT THIS TREND TO CONTINUE AT LEAST FOR THE NEXT 4-6
HOURS BEFORE HIGHER CLOUDS BEGIN TO SPREAD OVERHEAD. MVFR
CONDITIONS ARE ALSO MOVING INTO THE CHICAGOLAND TERMINALS.
SLIGHTLY HIGHER DEWPOINT DEPRESSIONS MAY PRECLUDE IFR FROM GETTING
TO ORD/MDW BUT WILL BE A CLOSE CALL.
CONCERN SHIFTS TO SEVERAL ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. TIMING OF THE SHORTWAVE OVER MINNESOTA BRINGS
ACTIVITY THROUGH RFD BY 17Z AND THROUGH THE CHICAGO TERMINALS
AROUND 18-20Z. HAVE CARRIED A VCTS FOR THIS TIME FRAME AS THERE
SHOULD BE CAPE AROUND DUE TO THE MOIST AIR MASS AND INCREASED
LAPSE RATES AHEAD OF THIS WAVE. FAVORABLE TIMING OF THE WAVE
THOUGH SLIGHTLY EARLY...BUT SHOULD ALSO BE A CONVERGENT AXIS AS
THE LAKE BREEZE BEGINS TO SETUP AS WELL. CARRIED A VCSH AFTER DUE
TO THE FORCING POSSIBLY BEING THROUGH THE TERMINALS AND SLIGHTLY
SHALLOWER MOISTURE AVAILABILITY. COVERAGE LOOKS TO BE SCATTERED AT
THIS POINT.
LASTLY...WINDS WILL SHIFT TO NORTHERLY MONDAY MORNING...THEN GAIN
AN ONSHORE COMPONENT THROUGH THE MORNING/EARLY AFTERNOON AS THE
LAKE INFLUENCE KICKS IN. AT THIS POINT MOST HI-RES GUIDANCE KEEPS
WINDS UNDER 10 KT...THOUGH EXPECT A FEW GUSTS AT THE SENSORS TO
GET CLOSE TO THAT THRESHOLD.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 AM CDT
LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY THIS EVENING. THIS WILL ENABLE A TRAILING SURFACE TROUGH TO PASS
OVER THE LAKE THIS MORNING AND SHIFT WINDS NORTHERLY. SEVERAL WEAK
LOWS ALONG THE TROUGH AXIS WILL CONSOLIDATE INTO A SLIGHTLY DEEPER
LOW OVER THE EASTERN GREAT LAKES. HIGH PRESSURE OVER THE NORTHERN
PLAINS WILL SHIFT INTO UPPER MIDWEST TOMORROW. IN BETWEEN THESE TWO
FEATURES...NORTHERLY WINDS WILL INCREASE TO 15-25 KTS BY TUESDAY
MORNING. AS THE HIGH MOVES EAST...THESE NORTHERLY WINDS WILL SLOWLY
DIMINISH TUESDAY NIGHT INTO WEDNESDAY. WINDS WILL SHIFT TO THE
SOUTHWEST WEDNESDAY NIGHT AS THE HIGH SETTLES SOUTHEAST OF THE LAKE
AND LOW PRESSURE APPROACHES HUDSON BAY. SPEEDS LOOK TO INCREASE INTO
THE 15-25KT RANGE THURSDAY INTO THURSDAY NIGHT. HIGH PRESSURE WILL
SHIFT WINDS BACK NORTHERLY TOWARD THE WEEKEND.
KMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
123 AM CDT MON AUG 10 2015
.SHORT TERM...
219 PM CDT
THROUGH MONDAY...
THINKING THIS AFTERNOON AND EVENING WILL BE RELATIVELY QUIET AND
POSSIBLY QUIETER THAN WHAT IS CURRENTLY FORECAST. STRAY SHOWERS ARE
OUT OVER THE LAKE AND SOUTH OF I-80 NEAR OTTAWA AND OVER NW
INDIANA. THE MCV FROM THIS MORNING/S COMPLEX IS SPINNING OVER
WESTERN MO AND SOUTHERN IL BASED ON SATELLITE DATA WITH NEW
CONVECTION FIRING OVER NORTHERN MO. THE LATEST RAP ANALYSIS
INDICATES THERE IS ABOUT 500 J/KG OF CAPE OVER THE FAR SOUTHERN
CWA WITH LITTLE TO NO CAPE OVER THE REST OF THE CWA.
GUIDANCE IS STRUGGLING WITH WHERE CONVECTION WILL FIRE GOING INTO
THIS AFTN AND HAVE LOW CONFIDENCE IN THE EXACT DETAILS MYSELF.
THINKING THE MAJORITY OF CONVECTION WILL OCCUR TO THE WEST AND SOUTH
OF THE CWA...BUT CANNOT RULE OUT A FEW SHOWERS AND/OR STORMS AS THE
MCV SHIFTS EAST OVER SOUTHERN IL. LOWERED PRECIP CHANCES INTO THE
CHANCE RANGE BELOW 50% AT BEST WITH THE HIGHEST VALUES SOUTH OF I-
80. WHILE STORMS MAY PRODUCE HEAVY DOWNPOURS AND A GUST OF
WIND...SEVERE WEATHER IS NOT EXPECTED. ONCE AGAIN...AREAS NORTH OF
I-88 MAY END UP BEING DRY BUT DID NOT HAVE ENOUGH CONFIDENCE TO GO
DRY AT THIS TIME. LONG STORY SHORT...ISOLATED SHOWERS ARE POSSIBLE
NORTH OF I-80 WITH ISOLATED TO SCATTERED SHOWERS AND A FEW STORMS
SOUTH OF I-80.
AS THE MCV SHIFTS EAST THIS EVENING...THE THREAT OF SHOWERS AND
STORMS WILL ALSO SHIFT TO LOCATIONS ALONG AND EAST OF I-55.
EXPECTING FOG TO DEVELOP OVERNIGHT AS WINDS DIMINISH AND SATURATED
AIR COOLS. SOME AREAS MAY SEE DENSE FOG...VSBY OF 1/4 A MILE OR
LESS...BUT AS OF RIGHT NOW EXPECTING MOSTLY AREAS OF FOG WITH VSBY
GREATER THAN 1/4 OF A MILE.
A SHORTWAVE TROUGH TRAVELS ACROSS WI TOMORROW WITH VORTICITY
STREAMERS PASSING OVER FAR NORTHERN IL. THINKING SCATTERED SHOWERS
AND STORMS WILL FORM ALONG THE VORT STREAMERS WITH BETTER COVERAGE
NORTH OF I-80 ESPECIALLY ALONG THE WI/IL STATE LINE. THINKING
COVERAGE WILL BE HIT OR MISS WITH PLENTY OF RAIN FREE HOURS. DID
NOT MAKE MANY CHANGES TO HIGH TEMPS MONDAY WITH COOLER AIR SINKING
IN FROM THE NORTH AND THICK CLOUD COVER. EXPECTING HIGHS AROUND 80
ALONG THE IL/WI STATE LINE AND ALONG THE LAKE WITH LOW TO MID 80S
SOUTH OF I-80.
JEE
&&
.LONG TERM...
MONDAY NIGHT THROUGH SUNDAY...
251 PM...MAIN FORECAST CONCERN IS THE CHANCE OF THUNDERSTORMS
THURSDAY NIGHT THRU FRIDAY NIGHT.
WEAK LOW PRESSURE IS EXPECTED TO BE EAST OF THE AREA AND MOVING
ACROSS THE SOUTHERN GREAT LAKES REGION MONDAY EVENING. THERE IS A
SLIGHT CHANCE OF AN EVENING SHOWER OR THUNDERSTORM BUT ANY ACTIVITY
SHOULD BE QUICKLY DIMINISHING BY MID/LATE EVENING. HIGH PRESSURE
THEN BUILDS ACROSS THE REGION TUESDAY AND WEDNESDAY. NORTHERLY
WINDS MAY BE A BIT BREEZY NEAR THE LAKE INTO NORTHWEST INDIANA
TUESDAY WITH THE CENTER OF THE HIGH STILL WEST OF THE AREA WITH
CONTINUED LIGHTER NORTHERLY WINDS ON WEDNESDAY...WITH COOLER TEMPS
AT THE LAKESHORE BOTH DAYS.
WEDNESDAY NIGHT/THURSDAY MORNING WILL BE A BIT COOLER WITH LOWS
POSSIBLY IN THE MID/UPPER 50S AWAY FROM THE URBAN AREAS. BUT AS
THE HIGH SHIFTS EAST THURSDAY...WARMER SOUTHWESTERLY FLOW WILL
RETURN WITH WINDS PERHAPS BECOMING BREEZY THURSDAY AFTERNOON.
HIGHS WILL LIKELY REBOUND INTO THE MID 80S THOUGH STILL SOME
DIFFERENCES REGARDING HOW MUCH WARMER TEMPS COULD BECOME.
DIFFERENCES BEGIN TO SHOW UP FRIDAY AND FRIDAY NIGHT WITH THE GFS
BRINGING A FRONTAL BOUNDARY ACROSS THE AREA FRIDAY AFTERNOON/
EVENING WHILE THE ECMWF KEEPS THIS FRONT NORTH OF THE CWA. A
LITTLE TOO EARLY TO DETERMINE SPECIFICS BUT GRADIENT APPEARS
LIGHT ENOUGH THAT A LAKE BREEZE IS POSSIBLE FRIDAY AFTERNOON.
PRECIP CHANCES WILL LIKELY DEPEND ON HOW MUCH OF THE FRONTAL
BOUNDARY REACHES THE AREA. HAVE LOW CHANCE POPS FOR NOW...BUT
CONFIDENCE IS FAIRLY LOW. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* GRADUAL LOWERING OF CIG/VIS THROUGH MVFR/IFR OVERNIGHT. A FEW
SPOTTY SHOWERS POSSIBLE. IMPROVEMENT FROM IFR/MVFR EXPECTED
DURING MONDAY MORNING.
* NORTHERLY WINDS MONDAY...LIKELY BECOMING NORTHEAST WITH LAKE
BREEZE DURING THE AFTERNOON.
* SCATTERED TSRA MONDAY AFTERNOON.
KMD
//DISCUSSION...UPDATED 06Z...
A FEW LOW TOPPED SHOWERS IN COOK COUNTY AND OVER THE LAKE IN MOIST
SW FLOW ATOP A LINGERING ELEVATED FRONT. CARRYING A VCSH FOR THESE
FOR THE NEXT FEW HOURS BUT SHOULD BE LOW IMPACT.
OVERNIGHT CONCERN FOCUSES ON CEILING AND VISIBILITY.
DETERIORATION OF CONDITIONS HAD BEEN SLOW GOING BUT THE DOWNWARD
TREND IS PICKING UP QUICKLY...ESPECIALLY IN OUTLYING AREAS WHERE
SOME CLEARING SKIES HAVE ALLOWED CIGS AND VIS TO DROP INTO IFR AND
EVEN LIFR. EXPECT THIS TREND TO CONTINUE AT LEAST FOR THE NEXT 4-6
HOURS BEFORE HIGHER CLOUDS BEGIN TO SPREAD OVERHEAD. MVFR
CONDITIONS ARE ALSO MOVING INTO THE CHICAGOLAND TERMINALS.
SLIGHTLY HIGHER DEWPOINT DEPRESSIONS MAY PRECLUDE IFR FROM GETTING
TO ORD/MDW BUT WILL BE A CLOSE CALL.
CONCERN SHIFTS TO SEVERAL ADDITIONAL PERIODS OF SHOWERS AND
THUNDERSTORMS. TIMING OF THE SHORTWAVE OVER MINNESOTA BRINGS
ACTIVITY THROUGH RFD BY 17Z AND THROUGH THE CHICAGO TERMINALS
AROUND 18-20Z. HAVE CARRIED A VCTS FOR THIS TIME FRAME AS THERE
SHOULD BE CAPE AROUND DUE TO THE MOIST AIR MASS AND INCREASED
LAPSE RATES AHEAD OF THIS WAVE. FAVORABLE TIMING OF THE WAVE
THOUGH SLIGHTLY EARLY...BUT SHOULD ALSO BE A CONVERGENT AXIS AS
THE LAKE BREEZE BEGINS TO SETUP AS WELL. CARRIED A VCSH AFTER DUE
TO THE FORCING POSSIBLY BEING THROUGH THE TERMINALS AND SLIGHTLY
SHALLOWER MOISTURE AVAILABILITY. COVERAGE LOOKS TO BE SCATTERED AT
THIS POINT.
LASTLY...WINDS WILL SHIFT TO NORTHERLY MONDAY MORNING...THEN GAIN
AN ONSHORE COMPONENT THROUGH THE MORNING/EARLY AFTERNOON AS THE
LAKE INFLUENCE KICKS IN. AT THIS POINT MOST HI-RES GUIDANCE KEEPS
WINDS UNDER 10 KT...THOUGH EXPECT A FEW GUSTS AT THE SENSORS TO
GET CLOSE TO THAT THRESHOLD.
KMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH IN WINDS.
* MEDIUM IN CIG/VIS TRENDS TONIGHT/EARLY MONDAY.
* MEDIUM-LOW IN MONDAY AFTERNOON TSRA.
KMD
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY AND WEDNESDAY...VFR. NORTH-NORTHEAST WINDS.
THURSDAY...VFR. SLIGHT CHANCE TSRA THURSDAY NGT. WEST-SOUTHWEST
WINDS.
FRIDAY...CHANCE TSRA. WEST-SOUTHWEST WINDS.
SATURDAY...VFR. NORTHEAST WINDS.
RATZER
&&
.MARINE...
251 PM...LOW PRESSURE OVER NORTHERN ONTARIO WILL MOVE INTO QUEBEC
BY MONDAY EVENING. A TRAILING COLD FRONT WILL MOVE ACROSS THE LAKE
LATE TONIGHT INTO MONDAY MORNING SHIFTING WINDS NORTHERLY. ANOTHER
WEAK LOW WILL MOVE SOUTH OF THE LAKE MONDAY AFTERNOON AS HIGH
PRESSURE BUILDS INTO THE NORTHERN PLAINS. THE GRADIENT WILL
TIGHTEN BETWEEN THESE TWO FEATURES WITH NORTHERLY WINDS INCREASING
TO 15-25 KTS BY TUESDAY MORNING. AS THE HIGH MOVES EAST...THESE
NORTHERLY WINDS WILL SLOWLY DIMINISH TUESDAY NIGHT INTO WEDNESDAY.
WINDS WILL SHIFT TO THE SOUTHWEST WEDNESDAY NIGHT AS THE HIGH
SETTLES SOUTHEAST OF THE LAKE AND DEPENDING ON HOW STRONG THE
GRADIENT BECOMES...SPEEDS MAY INCREASE INTO THE 15-25KT RANGE
THURSDAY INTO THURSDAY NIGHT. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
338 PM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 335 PM EDT MON AUG 10 2015
A COUPLE OF UPPER LEVEL DISTURBANCES WILL CONTINUE TO PRODUCE
SCATTERED SHOWERS AND THUNDERSTORMS THIS EVENING. DRIER AIR WILL
FILTER INTO THE AREA LATER THIS EVENING INTO THE OVERNIGHT BEHIND
THIS SYSTEM. DRY WEATHER IS THEN EXPECTED THROUGH MID WEEK. LOW
TEMPERATURES TONIGHT WILL DROP INTO THE LOWER TO MID 60S. HIGH
TEMPERATURES ON TUESDAY WILL REACH INTO THE MID TO UPPER 70S.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
LEAD SHORT WAVE WHICH TRACKED ACROSS THE AREA EARLIER TODAY ALLOWED
FOR INITIAL WEAK LAKE ENHANCED SURFACE TROUGH TO SERVE AS FOCUSING
MECHANISM FOR SCATTERED SHOWERS/ISOLATED STORMS. OVER PAST
HOUR...STARTING TO SEE UPSWING IN CONVECTIVE COVERAGE ALONG THIS
BOUNDARY AS A STRONGER UPSTREAM VORT MAX ACROSS NORTHERN ILLINOIS
CONTINUES TO APPROACH THE AREA. A SECONDARY AREA OF
SCATTERED/NUMEROUS SHOWERS/STORMS HAS DEVELOPED ACROSS FAR
SOUTHERN/AND MAINLY SOUTH OF FORECAST AREA ACROSS CENTRAL INDIANA.
THIS AREA APPEARS BE TIED MORE CLOSELY TO ENHANCED LOW LEVEL THETAE
ADVECTION...WHICH ALSO IS COLOCATED WITH MORE PRONOUNCED INSTABILITY
AXIS WITH LATEST RUC ANALYSIS DEPICTING 100 HPA MLCAPES ON THE ORDER
OF 1000-1500 J/KG. MODEST DEEP LAYER SHEAR AND AND WEAK TO MODERATE
INSTABILITY WILL CONTINUE TO POSE SOME THREAT OF ISOLD STRONG STORMS
WITH GUSTY WINDS AS THE MAIN THREAT. WHILE BRIEF VERY HEAVY RAINFALL
IS POSSIBLE...PROPAGATION VECTORS ARE SLIGHTLY MORE PROGRESSIVE THIS
AFTERNOON IN COMPARISON TO LAST EVENING AND CURRENT THINKING IS THAT
WHILE LOCALIZED PONDING OF WATER/MINOR FLOODING IS POSSIBLE WITH THE
STRONGER STORMS...FLASH FLOODING CONCERNS SHOULD BE MINIMAL.
PRIMARY INSTABILITY AXIS SHOULD BEGIN TO ADVECT ACROSS FAR EASTERN
PORTIONS OF THE FORECAST AREA LATE THIS AFTERNOON...BUT WEAK
INSTABILITY WILL REMAIN ACROSS ENTIRE FORECAST AREA AS
AFOREMENTIONED NORTHERN ILLINOIS VORT MAX ALLOWS FOR EROSION OF
RELATIVELY 800-700 HPA LAYER NOTED PER EARLIER AMDAR REGIONAL
SOUNDINGS. THIS SHOULD ALLOW FOR ENOUGH LINGERING INSTABILITY WITH
STRONGER ILLINOIS VORT MAX TO KEEP SOME CHANCE OF ISOLD-SCT
CONVECTION ACROSS THE AREA EARLY THIS EVENING. QUIET CONDITIONS
EXPECTED LATER THIS EVENING INTO THE OVERNIGHT AS SECONDARY SFC
TROUGH USHERS IN COOLER AND DRIER LOW LEVEL AIR. QUIET WEATHER
EXPECTED FOR TUESDAY WITH PERSISTENT MID LEVEL SUBSIDENCE...ALTHOUGH
THE NEXT IN SERIES OF UPPER LEVEL SHORT WAVES IS EXPECTED TO DIG
ACROSS THE GREAT LAKES EARLY TUESDAY...WHICH COULD PROMOTE AN
ISOLATED SHOWER ACROSS SOUTHEAST LOWER MICHIGAN. GIVEN VERY MARGINAL
MOISTURE PROFILES...WILL OMIT FROM FORECAST WITH JUST SLIGHTLY MORE
CONCENTRATED DIURNAL CU ACROSS THE FAR NORTHEAST. DESPITE LOW LEVEL
CAA...GOOD DEAL OF INSOLATION MOST AREAS SHOULD ALLOW FOR HIGHS IN
THE MID TO UPPER 70S.
&&
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 335 PM EDT MON AUG 10 2015
HIGH PRESSURE MOVING OUT OF CANADA WILL BRING COOL...DRY
WEATHER FOR THE FIRST PORTION OF THE LONG TERM PERIOD. AS THE
LONGWAVE PATTERN BECOMES MORE ZONAL INTO THE WEEKEND...
TEMPERATURES WILL WARM AND A FEW FRONTAL BOUNDARIES WILL DROP
SOUTHWARD INTO THE GREAT LAKES REGION WITH SHOWERS AND
THUNDERSTORMS POSSIBLE. THE FIRST OF THESE FRONTS WILL DROP
THROUGH ON FRIDAY. A FEW STORMS ARE POSSIBLE ALONG THIS
FRONT...BUT LIMITED INSTABILITY SHOULD LIMIT WIDESPREAD
DEVELOPMENT. THIS FIRST FRONT WILL SETTLE SOUTH OF THE AREA OVER
THE WEEKEND WHICH SHOULD KEEP OUR AREA DRY.
BETTER SHOWERS AND STORM CHANCES RETURN BY THE EARLY PART OF NEXT
WEEK AS MODEL CONSENSUS STALLS A FRONTAL BOUNDARY ACROSS THE
SOUTHERN GREAT LAKES. DEWPOINTS IN THE UPPER 60S TO LOW 70S COUPLED
WITH DAYTIME HEATING SHOULD PROVIDE WEAK TO MODERATE INSTABILITY
EACH DAY...DEPENDING ON THE DEGREE OF HEATING. AT THIS TIME...MID
LEVEL LAPSE RATES AND DEEP LAYER SHEAR LOOK LACKLUSTER WHICH SHOULD
PRECLUDE ANY ORGANIZED SEVERE WEATHER THREAT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 138 PM EDT MON AUG 10 2015
LAKE ENHANCED SURFACE TROUGH AXIS HAS BEEN FOCAL POINT FOR
SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS ACROSS NORTH CENTRAL
INDIANA. THE IMMEDIATE NEAR TERM FOCUS IN THE NEXT 2 HOURS FOR
THIS ACTIVITY SHOULD REMAIN SOUTHEAST OF KSBN...AND AFFECT MAINLY
KFWA BETWEEN 19Z-22Z. THIS SURFACE TROUGH DOES MARK A PARTICULARLY
PRONOUNCED GRADIENT IN TERMS OF MOISTURE...AND ADDITIONAL
SHOWERS/STORMS HAVE DEVELOPED ACROSS NORTHEAST ILLINOIS IN CLOSER
PROXIMITY TO STRONGER UPPER VORT MAX. THUS...STILL EXPECTING
SHOWERS AND PERHAPS AN ISOLATED THUNDERSTORM TO AFFECT KSBN IN THE
20Z-22Z TIMEFRAME. WITH INSTABILITY SOMEWHAT ON THE MARGINAL SIDE
AND EXPECTED TO BE MORE PRONOUNCED AT KFWA...WILL LIMIT THUNDER
MENTION TO VCTS AT KFWA. SHOWERS/STORMS SHOULD DIMINISH AFTER 23Z
WITH DRIER AIR ADVECTING INTO NORTHERN INDIANA AND QUIET AVIATION
WEATHER CONDITIONS THROUGH THE REMAINDER OF THE PERIOD. NORTHWEST
WINDS SHOULD INCREASE IN GUSTINESS INTO THE 15 TO 20 KNOT RANGE
FOR TUESDAY AFTERNOON.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...BENTLEY
AVIATION...MARSILI
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1118 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 1115 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS WILL PERSIST THIS AFTERNOON
AND WILL BECOME MORE NUMEROUS OVER NORTHEAST INDIANA AND NORTHWEST
OHIO AS A LOW PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF
THESE STORMS MAY PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST
OF INTERSTATE 69. HIGH PRESSURE AND DRY CONDITIONS WILL RETURN
OVERNIGHT AND PERSIST UNTIL THE END OF THE WEEK. TODAY WILL BE THE
LAST MUGGY DAY FOR A WHILE WITH HIGHS AROUND 80 DEGREES. LESS HUMID
AND SLIGHTLY COOLER CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EDT MON AUG 10 2015
THE COMBINATION OF A WEAK MID LEVEL TROUGH AND LOW LEVEL THETAE
ADVECTION AT THE NOSE OF LOW LEVEL MOISTURE AXIS HAS ALLOWED FOR
SCATTERED SHOWER DEVELOPMENT ACROSS PORTIONS OF SOUTH CENTRAL
LOWER MICHIGAN/FAR NORTHEAST INDIANA THIS MORNING. REGIONAL AMDAR
SOUNDINGS JUST TO THE WEST DO DEPICT A RELATIVELY WARM 800-700 HPA
WHICH IS LIKELY PROVIDING SOME INHIBITION FOR SFC BASED PARCELS
ALONG ADVANCING FRONTAL BOUNDARY. AT LEAST TWO ADDITIONAL UPSTREAM
PERTURBATIONS APPEAR POISED TO TRACK ACROSS THE SOUTHERN GREAT
LAKES THIS EVENING...THE FIRST PUSHING INTO NORTHEAST ILLINOIS
CURRENTLY...WITH A SECOND UPPER SHORT WAVE ENTERING SOUTHERN
MINNESOTA. APPROACH OF THIS FIRST WAVE EARLY THIS AFTERNOON SHOULD
ALLOW FOR SOME COOLING OF AFOREMENTIONED 800-700 HPA WARM LAYER
AND A POTENTIAL OF SCATTERED SHOWER/ISOLATED THUNDERSTORM
DEVELOPMENT EVEN BEHIND INITIAL WIND SHIFT. IT STILL APPEARS AS
THOUGH MORE VIGOROUS CONVECTION SHOULD AFFECT AREAS EAST OF I-69
WHERE BETTER INSTABILITY AXIS SHOULD BE SITUATED. SEVERE THREAT
STILL APPEARS LOW BASED ON MARGINAL INSTABILITY PROFILES AND
OVERALL MODEST NATURE TO MID/UPPER FORCING. LOCALIZED HEAVIER
DOWNPOURS STILL APPAER TO BE THE MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 555 AM EDT MON AUG 10 2015
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE IN COVERAGE
TODAY AS A MIDLEVEL TROUGH APPROACHES THE REGION AND INTERSECTS A
VERY MOIST AIRMASS. ISOLATED THUNDERSTORMS POSSIBLE THIS MORNING
BUT BETTER CHANCES STILL LOOK TO BE AT KFWA THIS AFTERNOON.
PERIODS OF MVFR CONDITIONS POSSIBLE AS WEAK FRONTAL BOUNDARY
APPROACHES THE AREA BUT LATEST HI-RES/RAPID UPDATE GUIDANCE
SUGGESTS CEILINGS WILL LIKELY REMAIN ABOVE FUEL ALTERNATE
CRITERIA. CONDITIONS WILL IMPROVE BY THIS EVENING AS FRONT EXITS
AND DRIER AIR FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...MARSILI
SYNOPSIS...SKIPPER
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
555 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF THESE STORMS MAY
PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST OF INTERSTATE 69
THIS AFTERNOON. HIGH PRESSURE AND DRY CONDITIONS RETURN OVERNIGHT
AND PERSIST UNTIL THE END OF THE WEEK. ONE LAST MUGGY DAY TODAY
WITH HIGHS AROUND 80 DEGREES BUT LESS HUMID AND SLIGHTLY COOLER
CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 555 AM EDT MON AUG 10 2015
SHOWERS AND THUNDERSTORMS WILL GRADUALLY INCREASE IN COVERAGE
TODAY AS A MIDLEVEL TROUGH APPROACHES THE REGION AND INTERSECTS A
VERY MOIST AIRMASS. ISOLATED THUNDERSTORMS POSSIBLE THIS MORNING
BUT BETTER CHANCES STILL LOOK TO BE AT KFWA THIS AFTERNOON.
PERIODS OF MVFR CONDITIONS POSSIBLE AS WEAK FRONTAL BOUNDARY
APPROACHES THE AREA BUT LATEST HI-RES/RAPID UPDATE GUIDANCE
SUGGESTS CEILINGS WILL LIKELY REMAIN ABOVE FUEL ALTERNATE
CRITERIA. CONDITIONS WILL IMPROVE BY THIS EVENING AS FRONT EXITS
AND DRIER AIR FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
350 AM EDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 350 AM EDT MON AUG 10 2015
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TODAY AS A LOW
PRESSURE SYSTEM MOVES ACROSS THE REGION. A FEW OF THESE STORMS MAY
PRODUCE HEAVY RAIN AND GUSTY WINDS ALONG AND EAST OF INTERSTATE 69
THIS AFTERNOON. HIGH PRESSURE AND DRY CONDITIONS RETURN OVERNIGHT
AND PERSIST UNTIL THE END OF THE WEEK. ONE LAST MUGGY DAY TODAY
WITH HIGHS AROUND 80 DEGREES BUT LESS HUMID AND SLIGHTLY COOLER
CONDITIONS EXPECTED FOR THE REST OF THE WEEK.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM EDT MON AUG 10 2015
ANOTHER "GRUNGY" DAY IN STORE FOR THE LOCAL FORECAST AREA AS BROAD
MID/UPPER LEVEL HEIGHT FALLS INDUCE MODEST SURFACE CYCLOGENESIS OVER
THE GREAT LAKES WITH A VERY MOIST/MARGINALLY UNSTABLE ENVIRONMENT IN
PLACE. THIS SETUP WILL LIKELY LEAD TO SEVERAL ROUNDS OF SPORADIC
SHOWERS AND A FEW EMBEDDED THUNDERSTORMS. ALREADY A FEW ISOLATED
SHOWERS POPPING UP ACROSS THE REGION AND SHOULD SEE THIS ACTIVITY
GRADUALLY EXPAND DURING THE DAY AS DIFFUSE SURFACE BOUNDARY
CURRENTLY OVER IOWA PUSHES EASTWARD AND CAPITALIZES ON SOME DEGREE
OF DIURNAL HEATING. LAST FEW RUNS OF HRRR (AND TO A LESSER EXTENT
THE RAP) FINALLY SEEM TO HAVE A LITTLE BETTER HANDLE ON THE CURRENT
PICTURE AND SUGGEST PRECIP WILL EXPAND IN OUR NORTHWEST COUNTIES
DURING THE LATE MORNING (~14Z) AND PUSH SOUTHEASTWARD THROUGH THE
DAY. THIS SEEMS REASONABLE BASED ON LATEST RADAR MOSAIC/SURFACE OBS
AND BACKGROUND SYNOPTIC PATTERN. HAVE THEREFORE MASSAGED POP GRIDS A
BIT TO REFLECT THIS EXPECTED EVOLUTION. MIDLEVEL LAPSE RATES DO GET
A LITTLE BETTER WITH APPROACHING TROUGH AND AMPLE LOW LEVEL MOISTURE
WILL SUPPORT AROUND 1500 J/KG OF SBCAPE IN OUR EASTERN HALF THIS
AFTERNOON DESPITE ABUNDANT CLOUD COVER. THIS SHOULD BE ENOUGH FOR
DECENT COVERAGE OF THUNDERSTORMS BUT POTENTIAL FOR STRONG UPDRAFTS
AND SEVERE WEATHER APPEARS LOW. PASSING MIDLEVEL SPEED MAX DOES
YIELD GOOD DEEP LAYER SHEAR NUMBERS BUT WIND PROFILES IN THE 0-3KM
LAYER ARE FAIRLY LIGHT AND...GIVEN LESS THAN STELLAR INSTABILITY
VALUES...SUGGEST A LOW SEVERE RISK. MAIN THREAT WOULD BE AN ISOLATED
STRONG/SEVERE DOWNBURST WHERE ANY POCKETS OF ENHANCED CAPE MANAGE TO
DEVELOP. POCKETS OF HEAVY RAIN ALSO POSSIBLE GIVEN PW VALUES AROUND
1.75 INCHES BUT RECENT DRY SPELL AND OVERALL LACKLUSTER SYNOPTIC
FORCING SUGGEST THREAT FOR WIDESPREAD FLOODING IS LOW. PRECIP
SHOULD EXIT THE CWA BY THIS EVENING WITH COOLER AND MUCH DRIER AIR
FILTERING SOUTH. AFTER A MUGGY DAY TODAY WITH HIGHS AROUND
80F...EXPECT DEWPOINTS AND LOW TEMPS TO DROP BACK INTO THE LOWER
60S OVERNIGHT.
&&
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 350 AM EDT MON AUG 10 2015
HIGH PRESSURE OVER THE UPR MIDWEST TUE WILL MOVE SE TO INDIANA
WED PROVIDING FAIR WEATHER ACROSS OUR AREA. NW FLOW ALOFT WILL
ADVECT A COOL CANADIAN AIRMASS S-SE INTO OUR AREA RESULTING IN BLO
NORMAL TEMPS THROUGH THIS TIMEFRAME. DRY WX SHOULD CONT THU AS THE
HIGH MOVES SE OF THE AREA WITH WAA ON THE BACKSIDE OF THE HIGH
RESULTING IN A LITTLE WARMER TEMPS.
A CDFNT IS EXPECTED TO DROP SLOWLY S-SE ACROSS THE GRTLKS THU NGT-
FRI NGT. UPR RIDGE AXIS OVER THE ROCKIES IS ALSO EXPECTED TO MOVE
EAST IN THIS TIMEFRAME SO A GENERAL WKNG TREND OF THE FRONT IS
EXPECTED... BUT MEDIUM RANGE MODELS IN DECENT AGREEMENT SUGGESTING
AT LEAST SOME CONVECTION MAY FORM ALONG/AHEAD OF THE FRONT SO HAVE
ADDED LOW POPS FOR LATE IN THE WORKWEEK. BY THE WEEKEND THE UPR
RIDGE AXIS SHOULD MOVE OVER OUR AREA PROVIDING DRY WX WITH ABOVE
NORMAL TEMPS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 136 AM EDT MON AUG 10 2015
AVIATION CONDITIONS STILL EXPECTED TO GRADUALLY DETERIORATE
THROUGH THE MORNING AS BROAD TROUGH APPROACHES THE GREAT LAKES AND
INTERACTS WITH VERY MOIST ENVIRONMENT. LIGHT WINDS AND HIGH
SURFACE DEWPOINTS SUGGEST SOME PATCHY FOG AND LOW STRATUS POSSIBLE
LATER THIS MORNING. LEFT FORECAST CATEGORIES LARGELY IN PLACE DUE
TO LOWER CONFIDENCE...JUST ADJUSTED TIMING. ALSO ADDED A -SHRA
MENTION GIVEN MOST HI-RES GUIDANCE SHOW PRECIP BLOSSOMING AROUND
KSBN LATER THIS MORNING. CHANCE FOR A FEW THUNDERSTORMS AT KFWA
THIS AFTERNOON GIVEN SOME MARGINAL DIURNAL DESTABILIZATION BUT
EXACT TIMING AND COVERAGE REMAIN UNCERTAIN. CONDITIONS SHOULD
IMPROVE BY THE END OF THE TAF PERIOD AS FRONT EXITS AND DRIER AIR
FILTERS SOUTH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...JT
AVIATION...AGD
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 PM CDT TUE AUG 11 2015
...Updated for Aviation...
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The near term will bring chances for heavy rain producing
thunderstorms. The first opportunity will be later tonight as the 4
km NAM, HRRR and NMM models all redevelop convection later in the
day over eastern colorado that moves in to about the western two or
perhaps 3 tiers of KS counties. the key here to support convection
is the very high precipitable water values, and hence conditional
instability present. still no severe weather threat, with mainly
efficient warm rain processes and frequent lightning. easterly
surface wind, and an increasing surface pressure gradient is
expected wednesday with a transient 500 mb shortwave, in the western
counties, in proximity to the high precipitable water axis on the
west edge of the surface high. models again generate precipitation
into wednesday in this zone. extensive cloud cover may again muddle
the high temperature forecast, as occurred today and temperatures
should be at or below normal.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The upper ridge over the central and southern rockies will continue
to amplify, resulting in vorticity disturbances shifted farther
north across the northern plains. however, the GFS and ECMWF show a
vigorous wave during the weekend moving through the northern
states, effectively flattening the upper ridge and returning zonal
flow aloft to the central high plains. this setup will result in
low pressure across western kansas just ahead of an approaching
baroclinic zone/frontal boundary by early to mid week, and a
return to convective chances. the more zonal pattern may stay in
place for at least several days.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Wednesday EVENING)
ISSUED AT 612 PM CDT TUE AUG 11 2015
Light upslope winds will continue tonight as surface high pressure
is in control across the Central Plains. Thunderstorms are
forecast to move into the KGCK area around 09Z to around 12Z.
Current indications are they may fall apart before reaching KDDC
or KHYS. VFR conditions are expected except in thunderstorms.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 87 65 90 / 40 30 10 0
GCK 66 88 65 91 / 50 20 10 0
EHA 66 90 66 92 / 50 10 10 10
LBL 68 89 68 92 / 40 20 10 0
HYS 65 88 65 91 / 10 20 10 10
P28 68 87 67 89 / 20 20 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
325 PM CDT MON AUG 10 2015
.SYNOPSIS...
ISSUED AT 321 PM CDT MON AUG 10 2015
Light northeasterly surface winds prevailed across western and
central kansas this afternoon. Regional WSR88D as still showing 30
to 40 dbz reflectivity returns across the TX panhandles into
northeast oklahoma associated with the low to mid level baroclinic
zone that since has shifted south. Meanwhile a few surface based
storms have developed in south central and southeast colorado.
widespread 1.3 to 1.5 precipitable water values covered the
forecast area, with the greatest amounts in the south.
&&
.SHORT TERM...(THIS EVENING THROUGH Tuesday)
ISSUED AT 321 PM CDT MON AUG 10 2015
The latest arw and HRRR models were the most aggressive models
with respect to developing convection this afternoon. The 4 km nam
and the nmm were not as aggressive. However the nmm and 4 km HRRR
were also more aggressive with thunderstorms. The severe threat
will be minimal today and tonight with any storms that develop as
continued amplification the the upper ridge weakened the shear
profiles. However very heavy rainfall from efficient warm rain
processes will still be likely for the next day or so, but
steering flow will be weak or non existent. based on the HRRR,
thunderstorm coverage could become scattered by late in the
afternoon. additionally. thunderstorms development across
southeast colorado could spread into far southwest kansas later
this evening aided by weak vorticity advection embedded in the
northwest flow in the models.
.LONG TERM...(Tuesday NIGHT THROUGH Monday)
ISSUED AT 321 PM CDT MON AUG 10 2015
Beyond the short term, increasingly less humid conditions will
develop across central and much of western kansas as surface high
pressure from the northern plains begins to have greater
influence. The general low level moisture transport signal will
remain firmly anchored across the the western counties where the
main if any thunderstorms chances will be located, and the low
level jet may be the best mechanism for get a few thunderstorms
going. Generally high temperatures are forecast around 5 degrees
below climatology through the extended. Lowered dew points should
translate into overnight lows of a few degrees lower as well on
average.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Tuesday AFTERNOON)
ISSUED AT 1245 PM CDT MON AUG 10 2015
Light northeasterly upslope surface winds will continue through
the day, as a surface high pressure center over the northern
plains shifts to the southeast with time. The ARW and HRRR convective
allowing models indicate potential for convective redevelopment ,
but opposed to the less aggressive runs of the NMM and 4km NAM.
Additionally with surface convergence and upslope flow, and an
impulse aloft moving out of new mexico, higher probability for
storms exists over the far southeast kansas counties later this
evening. in either case, there is not enough confidence at this
time to include either tempo groups of prevailing convective
conditions at gck, much less ddc or hys.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 66 86 66 89 / 30 30 30 30
GCK 66 85 65 89 / 30 40 40 20
EHA 66 82 66 90 / 60 50 30 20
LBL 68 85 67 89 / 50 40 30 20
HYS 64 86 66 88 / 10 20 30 20
P28 70 86 68 88 / 10 10 30 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1246 PM CDT MON AUG 10 2015
...UPDATED AVIATION SECTION...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 259 AM CDT MON AUG 10 2015
A shortwave trough progressing across the northern plains has
pushed a cold front through western Kansas early this morning. A
few elevated showers and thunderstorms had developed and these
are expected to dissipate later this morning. A few thunderstorms
may redevelop this afternoon with daytime heating given the very
moist airmass north of the front, deep subtropical moisture at mid
levels and resultant weak capping. An organized cluster of
thunderstorms will probably develop just south and southwest of
Kansas along the frontal boundary this evening and tonight.
However, some elevated shower and thunderstorm activity is still
expected across far southwest Kansas tonight. Highs today will be
in the upper 80s to lower 90s.
.LONG TERM...(Tuesday THROUGH Sunday)
ISSUED AT 259 AM CDT MON AUG 10 2015
A cooler, post frontal regime can be expected this week with highs
mainly in the 80s through Thursday. However the airmass north of
the front will still be moist. Nocturnal showers and thunderstorms
are possible Tuesday night along and west of a line from Hays to
Dodge City given mid level warm advection. This precipitation will
probably be a little father east by Wednesday night, possibly all
the way into central Kansas. However, it does not appear as
though these will be organized heavy rains events. Drying and a
slight warming trend can be expected by the weekend as the mid to
upper level flow becomes more meridional as opposed to a more
favorable northwesterly direction, with highs warming into the
lower 90s. The next cold front may arrive by late Saturday night
or Sunday with small chances for thunderstorms.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Tuesday AFTERNOON)
ISSUED AT 1245 PM CDT MON AUG 10 2015
light northeasterly upslope surface winds will continue through the
day, as a surface high pressure center over the northern plains
shifts to the southeast with time. the arw and HRRR convective
allowing models indicate potential for convective redevelopment ,
but opposed to the less aggressive runs of the nmm and 4 km NAM.
additionally with surface convergence and upslope flow, and an
impulse aloft moving out of new mexico, higher probability for
storms exists over the far southeast kansas counties. in either
case, there is not enough confidence at this time to include
either tempo groups of prevailing convective conditions at gck,
much less ddc or hys.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 92 66 84 66 / 30 20 30 30
GCK 90 66 82 65 / 30 30 40 30
EHA 89 66 81 66 / 40 70 50 30
LBL 91 68 84 67 / 30 60 40 30
HYS 89 64 85 66 / 10 10 20 30
P28 92 70 87 68 / 60 10 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Finch
LONG TERM...Finch
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1137 PM MDT SUN AUG 9 2015
.SHORT TERM...(THIS AFTERNOON THROUGH MONDAY)
ISSUED AT 132 PM MDT SUN AUG 9 2015
EARLY AFTERNOON WV IMAGERY AND RAP H5 ANALYSIS SHOW RIDGE CONTINUING
TO DOMINATE PATTERN ACROSS SOUTHERN P.LAINS WITH WESTERLY FLOW
ACROSS THE NORTHERN PLAINS. H7 SHORTWAVE TROUGH HAS WEAKENED AND
SHIFTED EAST...WITH ANOTHER H7 SHORTWAVE TROUGH OVER NORTHCENTRAL
COLORADO. AT THE SURFACE HIGH PRESSURE IS IN PLACE OVER OUR
CWA...WITH A STATIONARY FRONT EXTENDING FROM NORTHEAST COLORADO
ACROSS NORTHCENTRAL NEBRASKA.
THIS AFTERNOON-TONIGHT...AS FIRST H7 TROUGH HAS WEAKENED AND SHIFTED
EAST SUBSIDENCE HAS SPREAD INTO THE WESTERN PART OF THE FORECAST
AREA WITH LOWER TD VALUES (UPPER 40S/LOWER 50S) ADVECTING INTO THE
WESTERN PARTS OF THE FORECAST AREA. RESULT HAS BEEN CAPE VALUES
DROPPING OFF SHARPLY AND SABLE AIR MOVING BACK OVER THE CWA. SHORT
RANGE GUIDANCE CONTINUES TO KEEP HIGHER TD/CAPE VALUES IN OUR
EASTERN CWA WITH ONLY 100-500 J/KG IN THE WEST THROUGH THE EVENING.
CAPE VALUES AROUND 2000 J/KG ACROSS OUR EASTERN CWA COULD SUPPORT A
FEW MARGINALLY SEVERE THUNDERSTORMS IF SOMETHING WAS TO DEVELOP
ALONG WHAT IS LIKELY A DEVELOPING DRY LINE. NOT A LOT OF CONFIDENCE
AND HI RES GUIDANCE HAS TRENDED AWAY FROM ADDITIONAL DEVELOPMENT IN
OUR EAST. IT APPEARS THAT CHANCES ARE DECREASING FOR MOST OF THE CWA
THIS AFTERNOON. THERE IS THE POSSIBILITY FOR A SHOWER OR
THUNDERSTORM IN THE WESTERN CWA AS ANOTHER SHORTWAVE MOVES IN FROM
THE WEST LATE THIS AFTERNOON THROUGH THIS EVENING...WITH BEST
PRECIP SIGNAL IN THE SW. NOT A LOT OF CONFIDENCE AT THIS POINT IN
COVERAGE...SO I DECIDED TO LIMIT POPS TO THE WEST THIS EVENING
WITH A DOWNWARD TREND THROUGH 06Z.
IT DOES APPEAR THAT HIGHER TD VALUES WILL BEGIN TO RECOVER OVERNIGHT
FROM THE EAST/NORTHEAST WITH SURFACE HIGH PRESSURE/LOW LEVEL
STABILITY SUPPORTING POSSIBLE FOG/STRATUS DEVELOPMENT. BASED ON
SHORT RANGE GUIDANCE AND PERSISTENCE I KEPT HIGHER FOG COVERAGE
(AREAS) LIMITED TO REPUBLICAN RIVER VALLEY IN SW NEBRASKA.
MONDAY...GUIDANCE CONTINUES TO SHOW PRECIP SIGNAL LINGERING ACROSS
THE SW PART OF OUR CWA. ANY SHORTWAVE TROUGHS/VORT MAXES ROTATING
THROUGH PERIPHERY OF THE RIDGE APPEAR TO REMAIN SW OF OUR CWA WITH
VERY LIMITED FORCING. INSTABILITY DOES BEGIN TO INCREASE SO IF
ACTIVITY WAS TO DEVELOP TO THE WEST WE COULD SEE DEVELOPMENT TOWARDS
THE SW PART OF OUR FORECAST AREA. I WASNT CONFIDENT ENOUGH TO
INCREASE POPS DESPITE OVERLAPPING QPF FIELDS IN GUIDANCE...SO I
LIMITED POPS TO 20/30 RANGE MONDAY AFTERNOON. HIGH TEMPS AS WITH THE
LAST FEW DAYS WILL BE HIGHLY DEPENDENT ON MORNING STRATUS CLEARING
WHICH IS CURRENTLY EXPECTED. RESULT SHOULD BE SEASONAL HIGHS IN THE
UPPER 80S/AROUND 90.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 244 PM MDT SUN AUG 9 2015
FORECAST PROBLEM WILL BE CONTINUED THUNDERSTORM CHANCES. SATELLITE
IS SHOWING AN AMPLIFIED AND MOSTLY PROGRESSIVE FLOW FROM THE PACIFIC
INTO NORTH AMERICA. SOUTHERN UNITED STATES RIDGE REMAINS CENTERED
OVER CENTRAL/EASTERN TEXAS.
MODELS STARTED OUT FINE AT JET LEVEL. AT MID LEVELS...THE
GFS/CANADIAN WERE INITIALLY DOING BETTER THAN THE REST OF THE OUT
WITH THE NAM/SREF THE WORST OF THE REST OF THE BUNCH. THE SREF
LOOKED LIKE IT WAS THE BEST AT THE SURFACE. IT LOOKED LIKE THE
GFS...CANADIAN AND ECMWF WERE DOING THE BEST ON THE LOW LEVEL
THERMAL FIELD AT THIS TIME.
MONDAY NIGHT...LOW LEVEL UPSLOPE WINDS WILL BE IN PLACE THROUGH THE
NIGHT AS SURFACE RIDGE NOSES DOWN INTO THE AREA. AS SHOWN THE LAST
TWO DAYS...THE SHORTWAVE RIDGE AT 700 MB WILL SLOWLY MOVE TOWARD THE
EAST THROUGH THE NIGHT AS A SHORTWAVE MOVES IN FROM THE WEST. MODELS
HAVE SLOWED THINGS UP A LITTLE...AS HAS THE TREND BEEN THE LAST FEW
DAYS AS WELL. THE GFS IS THE FURTHEST EAST WHICH IS NOT AN UCOMMON
THING WHEN IT COMES TO BREAKING DOWN RIDGES TOO FAST.
SO ONLY PROGRESSED THE POPS SLOWLY TO THE EAST THROUGH THE NIGHT.
THE COMBINATION OF SLOW STORM MOVEMENT...PWS OF 1 TO 1.5 INCHES AND
THE COMMON HEAVY RAIN SCENARIO OF A SHORTWAVE MOVING UP THE WEST
SIDE OF A RIDGE COULD PRODUCE SOME LOCALIZED HEAVY RAINFALL. RAMPED
THE AMOUNTS UP A LITTLE AND INCREASED THE INTENSITY OF THE RAINFALL
AS WELL. THE BEST CHANCE FOR RAINFALL WILL BE IN THE SOUTHWEST THIRD
TO HALF OF THE AREA. THIS PERIOD WILL NEED TO BE WASHED CLOSELY.
TUESDAY/TUESDAY NIGHT...SLOWLY EVOLVING SITUATION THAT BEGINS MONDAY
NIGHT...SLOWLY MOVING CONVECTIVELY INDUCED SYSTEM...CONTINUE THROUGH
THIS ENTIRE PERIOD. MODELS ARE IN GOOD AGREEMENT ABOUT THIS. MORE
THAN LIKELY SOME DEGREE OF CONVECTION WILL CONTINUE FROM THIS
PREVIOUS THROUGH THIS ENTIRE PERIOD. AGAIN SAME HEAVY RAIN SCENARIO
IS IN PLACE AS IN THE PREVIOUS PERIOD AND WILL HAVE TO BE WATCHED
CLOSELY. ALSO THE SOUTHWEST THIRD TO HALF WILL HAVE THE BEST CHANCE
OF RAINFALL...ESPECIALLY DURING THE DAY. THE AREA OF RAINFALL WILL
SLOWLY MOVE TO THE SOUTH AND EAST DURING THE NIGHT.
COMBINATION OF UPSLOPE SURFACE WINDS...LOTS OF CLOUD COVER AND
ONGOING PRECIPITATION...WILL KEEP TEMPERATURES FROM WARMING UP TOO
MUCH...ESPECIALLY IN THE SOUTHWEST HALF. SO LOWERED TEMPERATURES
AROUND 5 DEGREES OR SO. THE COOLEST OUTPUT HAS TEMPERATURES COOLER
THAN WHAT I HAVE THEM.
WEDNESDAY...SLOW MOVING UPPER SYSTEM WILL KEEP RAINFALL AROUND
THROUGH THE MORNING HOURS IN THE SOUTHEAST HALF. IF THERE IS ANY
MORE SLOWLY...THE POPS WILL NEED TO BE RAISED. TEMPERATURES WILL BE
A LITTLE WARMER BUT HOW MUCH WILL DEPEND ON HOW FAST THE SYSTEM AND
ASSOCIATED CLOUDS/RAINFALL MOVE OUT OF THE AREA. AGAIN IF ANY MORE
SLOWING TEMPERATURES WILL NEED TO BE LOWERED.
WEDNESDAY NIGHT THROUGH SUNDAY...NOT TOO MUCH HAS CHANGED FROM WHAT
THE MODELS HAVE BEEN DOING/SHOWING FROM THE LAST FEW DAYS. MODELS
STILL DIFFER ON THE AMPLITUDED AND POSITION OF WHAT IS NOW THE
SOUTHERN RIDGE THAT TRANSITIONS TO A MORE CENTERED WESTERN RIDGE. IN
GENERAL UPPER RIDGE STAYS CENTERED NEAR THE FOUR CORNERS REGION.
SINCE MUCH DOES CHANGE ALOFT...THE SURFACE ALSO DOES NOT CHANGE TOO
MUCH. A SURFACE TROUGH OR LINGERING FRONTAL BOUNDARY STAYS NEAR OR
OVER THE WESTERN PORTION OF THE AREA.
FORECAST WILL HINGE ON SMALL IMPORTANT DETAILS THAT WILL BE HARD TO
PIN DOWN AT THIS TIME SCALE. POSITION OF THE RIDGE SHOULD ALLOW
SUBTROPICAL MOISTURE/WEAK SHORTWAVE TROUGHS TO ROTATE AROUND THE
RIDGE INTO THE AREA. ALSO THE SURFACE BOUNDARY SHOULD HELP SET
THUNDERSTORMS OFF. THERE WILL NOT BE HIGH PRECIPITATION CHANCES BUT
HARD TO SAY THERE WILL NOT BE ANYTHING AT ALL. PER THE OVERNIGHT
DISCUSSION/REASONING...THE WESTERN PORTION OF THE AREA WILL PROBABLY
SEE THE BEST CHANCE DUE TO THE PROXIMITY OF THE SURFACE BOUNDARY.
THE NEW CRH_INIT IS IN GOOD AGREEMENT WITH THE ABOVE MENTIONED
SCENARIO/REASONING...SO ONCE AGAIN MADE NO CHANGES TO IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1131 PM MDT SUN AUG 9 2015
VFR CONDITIONS ARE EXPECTED AT KGLD FOR THE NEXT 24 HOURS. LATER
TONIGHT, BOUNDARY LAYER RH INCREASES TO 90 PERCENT OR MORE IN AN
AREA INCLUDING KMCK. CONDITIONS THERE MAY GET AS LOW AS IFR. VFR
CONDITIONS WILL RETURN TO KMCK BY MID MORNING. LATER MONDAY
AFTERNOON AND EVENING THERE IS A SLIGHT CHANCE OF THUNDERSTORMS
NEAR KGLD SO WILL INCLUDE VCTS. KMCK SHOULD NOT HAVE THUNDERSTORMS
UNTIL AFTER 06Z TUESDAY.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...BULLER
AVIATION...FS
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1159 PM CDT SUN AUG 9 2015
...UPDATE TO SHORT TERM CONVECTIVE FORECAST AND AVIATION FORECAST
DISCUSSION...
.UPDATE...
ISSUED AT 1152 PM CDT SUN AUG 9 2015
WHILE FORCING MECHANISMS REMAIN WEAK, THE ATMOSPHERE REMAINS QUITE
UNSTABLE WITH 2000-4000 J/KG OF MUCAPE ROOTED 2-3K FEET OFF THE
SURFACE. EFFECTIVE SHEAR IS SUFFICIENT TO SUSTAIN SUPERCELL
STRUCTURES MAINLY OVER NORTHERN PARTS OF THE AREA AND THE STORM
OVER REPUBLIC COUNTY HAS SHOWN SIGNS OF ORGANIZATION ALTHOUGH IT
HAS SO FAR REMAINED BELOW SEVERE LIMITS AND STRUGGLED TO REMAIN
ORGANIZED FOR A PROLONGED PERIOD. AN ADDITIONAL AREA OF
CONVERGENCE AND INCREASING CLOUD COVER IN THE 3500 FOOT AGL RANGE
INDICATE THAT ADDITIONAL SCATTERED STORMS MAY DEVELOP GENERALLY
ALONG THE I-70 CORRIDOR IN THE NEXT COUPLE OF HOURS AND THEN
PERHAPS INTO EAST CENTRAL KANSAS. BASICALLY, THERE ARE SEVERAL
AREAS OF WEAK FORCING AND WHETHER OR NOT ANY OF THESE AREAS CAN
INITIATE CONVECTION ARE THE PRIMARY QUESTION. IF STORMS DEVELOP, A
FEW STRONG TO SEVERE STORMS ARE POSSIBLE WITH WIND REMAINING THE
PRIMARY HAZARD ALONG WITH POCKETS OF HEAVY RAIN AND A SMALL CHANCE
FOR MARGINALLY SEVERE HAIL.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
CURRENT SURFACE ANALYSIS SHOWS THE MAIN SYNOPTIC BOUNDARY EXTENDING
SOUTHWARD FROM KANSAS CITY TO WICHITA, WHICH IS FORECAST TO SAG
SOUTHWARD THROUGH THE AFTERNOON AND EVENING HOURS. ALTHOUGH THE MORE
EVIDENT THERMAL GRADIENT HAS PUSHED INTO SOUTHEAST KS AND HAS BEEN
RESPONSIBLE FOR SCATTERED SHOWERS AND ISOLATED THUNDER THIS MORNING.
THIS HAS KEPT THE CLOUD COVER AROUND MUCH LONGER THAN FORECASTED,
BUT AN AREA OF CLEAR SKIES IS WORKING EASTWARD ACROSS NORTHEAST KS,
WHICH MAY ALLOW TEMPERATURES TO WARM INTO THE LOWER TO MIDDLE 90S.
HIGH MOISTURE POOLING IN THE BOUNDARY LAYER HAS KEPT DEW POINTS IN
THE MID TO UPPER 70S. EXPECT THAT HEAT INDICES WILL BE IN THE LOWER
100S THROUGH EARLY EVENING FOR LOCATIONS ALONG AND SOUTH OF I-70.
THERE WILL BE A FEW THINGS OF CONCERN LATER THIS EVENING AND
OVERNIGHT. THE MODELS SHOW A SHORTWAVE TROUGH ON THE NORTHERN
PERIPHERY OF THE UPPER HIGH CENTERED OVER THE SOUTHERN PLAINS WILL
TRACK ACROSS SOUTHERN KS TONIGHT. THIS MAY SUPPORT THE DEVELOPMENT
OF AN MCS OR MULTICELL CLUSTER IN WESTERN OR CENTRAL KS THIS EVENING
NORTH OF THE SURFACE BOUNDARY. SURFACE BASED CONVECTION HAS ALREADY
BEGAN IN NORTHWEST KS. AS THAT BOUNDARY DRIFTS SOUTHWARD THE TRACK
OF THE MCS MAY ALSO DO THE SAME AS DEPICTED BY THE NAM. THE PAST FEW
RUNS OF THE HRRR HAVE BEEN CLIPPING THE SOUTHERN FORECAST AREA WITH
THIS MCS. INSTABILITY HAS BEEN SOMEWHAT LIMITED TODAY ACROSS
SOUTHERN KS AS OPPOSED TO NORTHERN KS, WHICH HAS SET UP A DECENT
GRADIENT. THEREFORE IT IS UNCERTAIN HOW SEVERE THESE STORMS WILL BE
THIS EVENING, BUT THE TRACK MAY BE MORE FOCUSED ALONG THIS
INSTABILITY GRADIENT INSTEAD. AS FOR NOW THE BEST CHANCES FOR PRECIP
WILL BE SOUTH OF I-70 LATE THIS EVENING AND EARLY MORNING WITH THE
SLIGHT CHANCE FOR A STRONG STORM. WITH PLENTY OF MOISTURE AROUND AND
LIGHT LOW LEVEL WINDS ASSOCIATED WITH THE BOUNDARY THERE IS A CHANCE
FOR HAZE AND OR FOG EARLY TOMORROW MORNING. THERE ARE SOME
INDICATIONS THAT THE SKIES COULD CLEAR LATE TONIGHT AND ALLOW FOR
BOUNDARY LAYER COOLING. A FEW OF THE MODELS ARE HINTING AT A
NORTHERN SHORTWAVE THAT WILL TRACK OVER SD AND NE OVERNIGHT. THIS
MAY ALSO SUPPORT A SOUTHEASTWARD MOVING MCS THAT COULD REACH
NORTHERN KS AROUND SUNRISE. IN FACT, THE INSTABILITY IS ALREADY
DECENT IN THAT AREA, WHICH WOULD SUPPORT THIS SCENARIO BETTER.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 313 PM CDT SUN AUG 9 2015
THERE IS NOT MUCH CHANGE IN THE FORECAST FOR MONDAY NIGHT THROUGH
SUNDAY AS MODELS CONTINUE TO SHOW AN UPPER LEVEL RIDGE AMPLIFYING
TO THE WEST AND SOUTHWEST CAUSING NORTHWEST FLOW TO SET UP OVER
THE FORECAST AREA. ABOUT THE ONLY THING OF CONCERN IS THE
POSSIBILITY FOR SOME ELEVATED PRECIP ACROSS NORTH CENTRAL KS LATE
TUESDAY NIGHT AND WEDNESDAY MORNING. THERE ARE INDICATIONS THAT
CONVECTION IN THE MOUNTAINS COULD GENERATE A VORT MAX AND THEN
DRIFT EAST AND SOUTH THROUGH CENTRAL KS. FOR NOW MOST GUIDANCE
KEEPS ANY PRECIP JUST TO THE WEST OF THE FORECAST AREA. THIS SEEMS
TO MAKE SINCE AS MODELS BRING THE CENTER OF THE 850 MB RIDGE OVER
THE FORECAST AREA BY 12Z WED WITH NO REAL RETURN FLOW AND THE
DEEPER MOISTURE AXIS REMAINING OVER WESTERN KS. SO THE FORECAST
REMAINS DRY THROUGH NEXT WEEKEND WITH NO OBVIOUS SIGNS OF FORCING
IMPACTING THE FORECAST AREA AFTER WEDNESDAY.
TEMPS ARE EXPECTED TO BE COOLER THAN NORMAL FOR TUESDAY THROUGH
THURSDAY. MODELS ARE IN AGREEMENT THAT A MODIFIED HIGH PRESSURE
SYSTEM WILL BUILD INTO THE AREA WITH SOME WEAK COLD AIR ADVECTION
AND DRYER AIR. BECAUSE OF THIS LOWS SHOULD BE IN THE LOWER AND MID
60S WITH HIGHS IN THE 80S. BY FRIDAY AND INTO THE WEEKEND, THE
UPPER RIDGE IS EXPECTED TO PROPAGATE EAST INTO THE PLAINS AS AN
UPPER TROUGH OVER THE PACIFIC NORTHWEST COAST MOVES INLAND. THIS
SHOULD SHIFT THE THERMAL RIDGE OUT INTO THE PLAINS WITH HIGHS
WARMING BACK INTO THE LOWER AND MID 90S FOR THE WEEKEND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1152 PM CDT SUN AUG 9 2015
LOWER THAN NORMAL CONFIDENCE CONTINUES IN THE TAF. SCATTERED
THUNDERSTORMS MAY DEVELOP NEAR/OVER TAF SITES AT JUST ABOUT ANY
TIME THROUGH 13 OR 14Z. OTHERWISE DO EXPECT MVFR CIGS TO DEVELOP
IN THE NEXT FEW HOURS, PROBABLY BY 08Z...AND WITH SUCH AMPLE LOW
LEVEL MOISTURE MAY SEE SOME VIS RESTRICTIONS ESPECIALLY AFTER 09Z.
CIGS, LIKELY IN THE MVFR RANGE, EXPECTED TO CONTINUE THROUGH
AROUND NOON BEFORE SCATTERING OUT.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...SANDERS
LONG TERM...WOLTERS
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS JACKSON KY
653 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 653 PM EDT MON AUG 10 2015
SHOWERS/THUNDERSTORMS ASSOCIATED WITH A MID/UPPER LEVEL WAVE HAVE
EXITED TO THE EAST EARLY THIS EVENING. ADDITIONAL
SHOWERS/THUNDERSTORMS WERE OCCURRING ALONG A COLD FRONT NORTH OF
THE OHIO RIVER. THIS FRONT AND THE POTENTIAL FOR PRECIP WILL MOVE
SOUTHEAST THROUGH THE AREA DURING THE NIGHT. HAVE MODIFIED THE
PRECIP GRIDS TO REFLECT A LOW POP EARLY THIS EVENING...WITH A
LITTLE BIT BETTER CHANCE TO FOLLOW DURING THE NIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS JACKSON KY
350 PM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 350 PM EDT MON AUG 10 2015
18Z SFC ANALYSIS SHOWS AN AREA OF LOW PRESSURE MOVING THROUGH THE
OHIO VALLEY WITH A COLD FRONT NOW ENTERING WESTERN KENTUCKY. AHEAD
OF THIS BOUNDARY...PLENTY OF MOISTURE AND SOME BREAKS IN THE
CLOUDS HAVE ALLOWED A FEW CLUSTERS OF SHOWERS AND STORMS TO
DEVELOP THROUGH EAST KENTUCKY. TEMPERATURES ACROSS THE AREA VARY
GREATLY BASED ON THE PCPN WITH WESTERN PARTS OF THE CUMBERLAND
VALLEY DOWN NEAR 70 WHILE LOW TO MID 80S ARE NOTED ACROSS THE
NORTH AND EAST. WINDS ARE GENERALLY FROM THE SOUTHWEST TO WEST AT
5 TO 10 KTS WITH OCCASIONAL GUSTS TO 15 KTS.
THE MODELS ARE IN GOOD AGREEMENT AT MID LEVELS THROUGH THE SHORT
TERM PORTION OF THE FORECAST WITH AN AMPLIFYING TROUGH DIGGING
THROUGH THE GREAT LAKES AND OHIO VALLEY. THIS WILL PUSH THE
SOUTHERN PLAINS RIDGE BACK TO THE SOUTHWEST WHILE A SLEW OF MINOR
WAVES ROTATE THROUGH THE BASE OF THE TROUGH AND BRUSH BY/MOVE
THROUGH EAST KENTUCKY INTO WEDNESDAY MORNING. THE NAM REMAINS A
BIT STRONGER WITH THE TROUGH THAN THE CONSENSUS OF THE OTHER
MODELS. OTHERWISE...TIMING AND PLACEMENT ARE QUITE SIMILAR AMONGST
THE MODELS. ACCORDINGLY...HAVE FOLLOWED THE HRRR M0ST CLOSELY
THROUGH THE FIRST PART OF THE SHORT TERM WITH A GENERAL BLEND
FAVORED AFTER THAT.
SENSIBLE WEATHER WILL FEATURE AN ACTIVE LATE AFTERNOON AND EARLY
EVENING PERIOD AS CONVECTION MOVES THROUGH EASTERN KENTUCKY DRIVEN
BY INSTABILITY AND DIFFERENTIAL HEATING AS WELL AS OUTFLOW FROM
EARLIER STORMS. THE HIGH MOISTURE CONTENT IN THE AIR WILL MAKE
HEAVY RAINS A THREAT. IN ADDITION...A FEW OF THE STRONGER STORMS
COULD CONTAIN GUSTY WINDS WITH A SMALL POTENTIAL TO DO DAMAGE.
WILL CONTINUE TO MENTION THIS CONCERN IN THE FORTHCOMING UPDATE TO
THE HWO. THE INSTABILITY WILL WANE AFTER SUNSET...BUT THE
APPROACHING SFC FRONT WILL KEEP SHOWERS AND ISOLATED THUNDERSTORMS
POSSIBLE THROUGH THE EVENING AND INTO THE EARLY OVERNIGHT PERIOD.
DO EXPECT THE THUNDER TO BE MOSTLY GONE BY MIDNIGHT...THOUGH...SO
HAVE DROPPED ITS MENTION IN THE WX GRIDS AFTER THAT TIME. PATCHY
FOG WILL BE POSSIBLE AS WELL...POST FRONTAL...LATER TONIGHT...BUT
PLENTY OF CLOUDS AROUND SHOULD KEEP THE VISIBILITIES FROM GETTING
TOO LOW. A FEW SHOWERS MAY LINGER THROUGH FAR EASTERN KENTUCKY
INTO THE DAY TUESDAY AS HIGH PRESSURE ONLY SLOWLY PUSHES INTO THE
AREA. THIS HIGH WILL BRING IN DRIER AIR AND...EVENTUALLY...
CLEARING SKIES FROM WEST TO EAST LATER TUESDAY. A BETTER CHANCE
FOR FOG IN THE VALLEYS...PERHAPS LOCALLY DENSE...CAN THEN BE
ANTICIPATED FOR LATER TUESDAY NIGHT INTO WEDNESDAY MORNING.
STARTED WITH THE SHORTBLEND GUIDANCE THROUGH THE FIRST PART OF
THE FORECAST FOR THE T/TD/WIND GRIDS FOLLOWED BY THE SUPERBLEND
FOR THE REMAINDER OF THE TIME. DID MAKE SOME VERY MINOR CHANGES
TO LOWS TONIGHT AND TUESDAY NIGHT BASED ON THE TERRAIN. AS FOR
POPS...ENDED UP MOST SIMILAR TO A BLEND OF THE WETTER MAV AND
DRIER MET NUMBERS TONIGHT AND TUESDAY WITH SINGLE DIGIT POPS FOR
TUESDAY NIGHT IN LINE WITH GUIDANCE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
301 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 145 PM EDT MON AUG 10 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE CURRENT POP PATTERN
WITH SOME ADJUSTMENTS BASED ON THE LATEST HRRR INTO THE EVENING.
ALSO FINE TUNED THE T/TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 251 PM EDT MON AUG 10 2015
DRY AND PLEASANT WEATHER IS ON TAP FOR THE EXTENDED PORTION OF THE
FORECAST. A LARGE RIDGE OF HIGH PRESSURE IS FORECAST TO BECOME
ESTABLISHED OVER THE EASTERN THIRD OF THE CONUS FROM EARLY WEDNESDAY
ONWARD. THE RIDGE WILL USHER IN A MUCH COOLER AND DRIER AIR MASS
THAN ANY WE HAVE SEEN IN THIS PART OF THE COUNTY IN RECENT WEEKS.
BOTH DAY AND NIGHT TIME TEMPERATURES WILL BE RUNNING WELL BELOW
AVERAGE THE FIRST COUPLE OF DAYS AND NIGHTS OF THE PERIOD. HIGHS ON
TUESDAY AND WEDNESDAY ARE EXPECTED TO TOP OUT IN THE UPPER 70S FOR
MOST LOCATIONS...WITH OVERNIGHT LOWS WEDNESDAY AND THURSDAY NIGHT
DIPPING INTO THE UPPER 50S FOR EVERYWHERE...EXCEPT RIGHT ALONG THE
TENNESSEE BORDER...WHERE A FEW READINGS AT OR JUST ABOVE 60 MIGHT BE
REALIZED. NO PRECIPITATION IS IN THE FORECAST AT THIS POINT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
215 PM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 145 PM EDT MON AUG 10 2015
DID A QUICK UPDATE TO THE GRIDS TO REFLECT THE CURRENT POP PATTERN
WITH SOME ADJUSTMENTS BASED ON THE LATEST HRRR INTO THE EVENING.
ALSO FINE TUNED THE T/TD GRIDS PER THE LATEST OBS AND TRENDS.
THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
QUIET LONG TERM PERIOD IN STORE AS AN EXPANSIVE UPPER LEVEL RIDGE
OVER THE FOUR CORNERS REGION EXTENDS NORTHWARD INTO CENTRAL
CANADA. WHILE A TROUGH REMAINS IN PLACE OVER THE EASTERN CONUS...THE
HIGH AMPLITUDE RIDGE TO OUR WEST PLACES THE SOURCE REGION FOR OUR
AIRMASS ALOFT OVER THE PRAIRIE PROVINCES OF CANADA...SO NOT MUCH
OPPORTUNITY FOR MOISTURE RETURN. MODELS INDICATE A PIECE OF THE
UPPER TROUGH OVER THE EAST WILL RETROGRADE SOUTHWEST AND POSSIBLY
BREAK OFF INTO A WEAK CLOSED LOW OVER THE DEEP SOUTH. THIS MAY BRING
ENOUGH LOW LEVEL MOISTURE IN OFF THE ATLANTIC TO CAUSE SOME ISOLATED
DIURNAL CONVECTION OVER THE HIGHER TERRAIN OF THE SOUTHERN
APPALACHIANS AT TIMES...BUT NOT LIKELY AFFECTING OUR AREA. THE NET
RESULT SHOULD BE A DRY FORECAST WITH PLEASANT TEMPS AND HUMIDITY
MID WEEK SLOWLY MODERATING BACK TO SEASONAL NORMS BY THE WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 215 PM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL AT MOST SITES EARLY THIS AFTERNOON AS THE
CONVECTION HASN/T BEEN TOO WIDESPREAD AS OF YET. HOWEVER...A
HEALTHY CLUSTER OF SHOWERS AND STORMS ARE MOVING THROUGH THE
CUMBERLAND VALLEY. LOWER CIG AND VIS CAN BE EXPECTED FOR THOSE
LOCATIONS AS WELL AS OTHERS ACROSS THE FORECAST AREA WHEN THE
COVERAGE BECOMES MORE EXTENSIVE. FOR THIS...HAVE INCLUDED A TEMPO
TO IFR CONDITIONS WITH ANY STORMS. THE CONVECTION SHOULD BECOME
MORE SCATTERED BY LATE AFTERNOON AND THROUGH THE EVENING WITH A
LOSS OF THUNDER LIKELY FOLLOWING SUNSET. A FEW SHOWERS WILL
CONTINUE WELL INTO THE NIGHT...THOUGH ALONG WITH LOWERING CIGS AND
SOME MVFR FOG AT ALL SITES. CONDITIONS WILL IMPROVE BACK TO VFR BY
MID MORNING ON TUESDAY. OUTSIDE OF ANY STORMS...WINDS WILL BE
GENERALLY LIGHT THROUGH THE PERIOD FROM THE WEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1120 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1120 AM EDT MON AUG 10 2015
14Z SFC ANALYSIS SHOWS A BROAD AREA OF LOW PRESSURE CROSSING
THROUGH THE OHIO VALLEY NORTH OF KENTUCKY. A TRAILING COLD FRONT
ASSOCIATED WITH THIS IS APPROACHING THE REGION. HOWEVER...AHEAD OF
THIS BOUNDARY...AMPLE MOISTURE IS POOLING THROUGH EASTERN
KENTUCKY WITH DEWPOINTS PREDOMINATELY IN THE LOWER 70S. MORNING
BREAKS IN THE CLOUD COVER WILL HELP TO BUILD INSTABILITY THROUGH
THE CWA AS TEMPERATURES ARE CURRENTLY IN THE UPPER 70S AND LOWER
80S ON THEIR WAY TO THE MID AND UPPER 80S. THE QUESTION IS WHETHER
THE DEBRIS CLOUDS FROM THE EARLIER CONVECTION TO THE WEST WILL BE
ENOUGH TO INHIBIT THE DEVELOPMENT OF WIDESPREAD AND ORGANIZED
STORMS THROUGH THE AREA LATER THIS AFTERNOON. ALREADY A GROUP OF
SHOWERS AND DEVELOPING STORMS ARE TRACKING INTO THE CUMBERLAND
VALLEY. EXPECT THESE TO SPREAD INTO THE EARLY AFTERNOON WITH
ADDITIONAL POCKETS OF CONVECTION EXPANDING TO THE NORTH AND EAST.
THE LATEST HRRR MODEL AGREES WITH THIS SCENARIO WITH PEAK
CONVECTIVE ACTIVITY TAKING PLACE OVER THE JKL CWA BETWEEN 19 AND
23Z. HAVE UPDATED THE GRIDS WITH THIS IN MIND AS WELL AS INFUSED
THE LATEST SHORTBLEND GUIDANCE INTO THE T AND TD GRIDS. THOSE
LATER ONES WERE UPDATED TO BETTER REFLECT THE LATEST OBS AND
TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS WITH A
FRESHENED SET OF ZONES TO FOLLOW.
UPDATE ISSUED AT 654 AM EDT MON AUG 10 2015
WSR-88D CONTINUES TO INDICATE SOME ISOLATED SHOWERS MOVING
SOUTHEAST ACROSS PORTIONS OF EASTERN KY. EXPECT THIS MORNING
SHOWER ACTIVITY TO REMAIN LIGHT. THE HEAVIER STORMS REMAINED SOUTH
AND WEST OF THE REGION...AS MCS DIVED SOUTH TOWARD THE MORE
UNSTABLE ENVIRONMENT WHERE UPPER 70S TO LOW 80 DEWPOINTS WERE
REPORTED. STILL LOOKING AT INCREASING CHANCES OF SHOWERS AND
THUNDERSTORMS AS WE MOVE INTO THE AFTERNOON HOURS AHEAD OF A
APPROACHING COLD FRONT. SOME MINOR UPDATES TO POPS AND THEN
UPDATES TO TEMPS/DEWS/WINDS TO MATCH CURRENT CONDITIONS/TRENDS.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
OVERALL MODELS REMAIN IN GOOD AGREEMENT WITH OVERARCHING SYNOPTIC
PATTERN WITH TROUGHING CONTINUE TO DEEPEN IN THE EASTERN CONUS
THROUGH THE PERIOD. THIS MORNING WE ARE BEING MET WITH A FEW
SHOWERS SPREADING SE ACROSS PORTIONS OF EASTERN KY SEEN ON WSR-
88D. THIS HAS BEEN BROUGHT ON BY UPPER LEVEL WAVE AND INCREASING
LOW LVL JET ACROSS THE OHIO/TN VALLEYS. THESE ARE DEVELOPING AHEAD
OF AN APPROACHING SURFACE LOW PRESSURE AND COLD FRONT ACROSS THE
MIDWEST THIS MORNING. WHILE WE DO HAVE SHOWERS AND PERHAPS A
ISOLATED THUNDERSTORM THIS MORNING...BETTER CHANCES OF SHOWERS AND
THUNDERSTORMS WILL EXIST AS WE MOVE INTO THE AFTERNOON AHEAD OF
THE COLD FRONT.
THE QUESTION IS HOW MUCH DOES ON GOING ACTIVITY AND CLOUD COVER
PLAY ON THE OVERALL DESTABILIZATION...RIGHT NOW THIS LOOKS TO
HAVE SOME AFFECTS BUT INCREASING LOW LEVEL JET AND SOME INSULATION
LOOK TO BE ENOUGH TO FIRE OF STORMS THIS AFTERNOON. THIS LOOKS
REASONABLE WITH CA MODELS SHOWING GOOD AGREEMENT OF BEST ACTIVITY
GENERALLY AFTER 18Z. WHILE SOME OF THESE STORMS COULD BE
STRONG...THINKING OVERALL SEVERE THREAT REMAINS LOW WITH SHEAR
BEING MARGINAL AT BEST. THAT SAID MAIN THREAT WOULD BE ISOLATED
DAMAGING WIND GUST...AND THIS LINES UP WELL WITH SPC THINKING AND
OVERALL BROAD MARGINAL RISK. AFTER THIS SHOWER AND STORM ACTIVITY
WILL WAIN IN THE EVENING AND OVERNIGHT HOURS AS FRONT SLOWLY MOVES
EAST ACROSS THE REGION. MAINTAIN SOME INSTABILITY SHOWERS MAINLY
IN THE FAR EAST THROUGH THE DAY ON TUESDAY. OTHERWISE SOME SPOTS
ARE EXPECTED TO BEGIN THE DRYING OUT PROCESS IN THE WAKE OF THE
COLD FRONT...AS WE TRANSITION TO W/NW FLOW. THE OTHER ISSUE IS HOW
MUCH IF ANY FOG WILL BE SEEN EARLY TUESDAY GIVEN CLOUD COVER...SO
RIGHT NOW LEFT OUT OF THE FORECAST GIVEN LOWER CONFIDENCE. THAT
SAID VALLEYS AND AREAS THAT RECEIVED RAIN WILL HAVE THE BEST
CHANCES OF SEEING REASONABLE PRODUCTION.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 327 AM EDT MON AUG 10 2015
QUIET LONG TERM PERIOD IN STORE AS AN EXPANSIVE UPPER LEVEL RIDGE
OVER THE FOUR CORNERS REGION EXTENDS NORTHWARD INTO CENTRAL
CANADA. WHILE A TROUGH REMAINS IN PLACE OVER THE EASTERN CONUS...THE
HIGH AMPLITUDE RIDGE TO OUR WEST PLACES THE SOURCE REGION FOR OUR
AIRMASS ALOFT OVER THE PRAIRIE PROVINCES OF CANADA...SO NOT MUCH
OPPORTUNITY FOR MOISTURE RETURN. MODELS INDICATE A PIECE OF THE
UPPER TROUGH OVER THE EAST WILL RETROGRADE SOUTHWEST AND POSSIBLY
BREAK OFF INTO A WEAK CLOSED LOW OVER THE DEEP SOUTH. THIS MAY BRING
ENOUGH LOW LEVEL MOISTURE IN OFF THE ATLANTIC TO CAUSE SOME ISOLATED
DIURNAL CONVECTION OVER THE HIGHER TERRAIN OF THE SOUTHERN
APPALACHIANS AT TIMES...BUT NOT LIKELY AFFECTING OUR AREA. THE NET
RESULT SHOULD BE A DRY FORECAST WITH PLEASANT TEMPS AND HUMIDITY
MID WEEK SLOWLY MODERATING BACK TO SEASONAL NORMS BY THE WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 700 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL THIS MORNING ACROSS EASTERN KY...HOWEVER
SHORT DROPS TO MVFR VIS HAS BEEN SEEN IN SOME OF THE RAIN SHOWER
ACTIVITY SEEN ON WSR-88D SWEEPS. MUCH OF THE MORNING SHOULD
REMAIN VFR WITH BETTER STORM ACTIVITY REMAINING IN WESTERN END OF
THE STATE INTO TN ASSOCIATED WITH MCS. FROPA IS STILL EXPECTED TO
MOVE EASTWARD TOWARD THE REGION TODAY AND STORM ACTIVITY WILL FORM
AHEAD OF THE FRONT. OVERALL THE CONVECTIVE ALLOWING MODELS BRING
BEST CHANCES AFTER 18Z AND RIGHT NOW THINK WILL ADJUST TAF SITES
IN THAT DIRECTION...GIVEN THAT SOME SITES LIKELY HAD VCTS STARTING
TOO EARLY. AFTER THIS THE QUESTION OF HOW MUCH FOG DO WE GET IN
THE WAKE OF THE PRECIP AND FROPA...GIVEN THE UNCERTAINTY WENT WITH
JUST A GENERAL 4SM AFTER TEMPO GROUP FOR TS. OVERALL WINDS WILL
REMAIN GENERALLY LIGHT THROUGH THE PERIOD AROUND 5 TO 10
KNOTS...WITH CAVEAT OF ANY OF THE STORMS HAVE THE POTENTIAL TO
PRODUCE HIGHER GUST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...DJ
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
150 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 150 AM EDT MON AUG 10 2015
UPPER WAVE RIDING THROUGH THE FLOW HAS FIRED OFF SOME SHOWERS
AHEAD OF MAIN SURFACE LOW PRESSURE/COLD FRONT STILL DEVELOPING
ACROSS THE MIDWEST THIS EARLY MORNING HOUR. ALL THE PRECIP HAS
REMAINED LIGHT IN NATURE AT THIS POINT BASED OF THE LATEST WSR-88D
SWEEPS. DID UPDATE GRIDS TO ADD AT LEAST SOME ISOLATED POPS ACROSS
MUCH OF THE REGION OVERNIGHT...OTHERWISE MINOR ADJUSTMENTS MADE TO
THE TEMPS/DEWS/WINDS TOWARD LATEST OBS/TRENDS.
UPDATE ISSUED AT 1045 PM EDT SUN AUG 9 2015
A SHORTWAVE MOVING THROUGH THE OH VALLEY REGION IS BRINGING SOME
SHOWERS TO SOUTHERN OH AND NORTHERN KY. KCVG ONLY TRACED AS THESE
PASSED...SO THESE LIKELY DO NOT AMOUNT TO MUCH MORE THAN
SPRINKLES. OTHERWISE...MODELS INDICATE ADDITIONAL CONVECTION
UPSTREAM WILL MOVE EAST AND OR DEVELOP AND MOVE EAST TO EAST
SOUTHEAST AS IT WORKS AROUND THE MID LEVEL RIDGE CENTERED OVER THE
SOUTHERN PLAINS. DUE TO UNCERTAINTY IN TIMING AND MODEL
DIFFERENCES IN EVOLUTION OF CONVECTION OVERNIGHT AND INTO THE DAY
ON MONDAY...NO CHANGES WERE MADE TO POPS TOWARD DAWN. THE ONLY
CHANGES TO POPS WERE IN THE SHORT TERM TO ACCOUNT FOR THE SHOWERS
MOVING TOWARD NE KY. OTHERWISE...HOURLY GRIDS WERE FRESHENED UP
BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS.
UPDATE ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 115 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL ACROSS EASTERN KY THIS OVERNIGHT HOUR.
THERE ARE A FEW SHOWERS AND SPRINKLES THAT HAVE DEVELOPED ACROSS
PORTIONS OF THE REGION...SO DID GO WITH SOME VCSH AT MOST
SITES. HOWEVER SITES SHOULD REMAIN VFR THROUGH MUCH OF THE
BEGINNING OF THE PERIOD. UPSTREAM MCS RELATED CONVECTION IN
WESTERN KY HAS BEEN ON A WEAKENING TREND AND WILL PROBABLY MISS
THE REGION IN GENERAL. OTHERWISE THINK THE BETTER CONVECTION WILL
DEVELOP LATER MORNING INTO THE AFTERNOON HOURS. THEREFORE STAYED
CLOSE TO THE PREVIOUS FORECAST WITH TEMPO GROUP TO EXPRESS DROPS
TO MVFR/IFR AT TIMES TOMORROW AFTERNOON AND EARLY EVENING. WINDS
WILL BE GENERALLY LIGHT THROUGH THE PERIOD WITH HIGHER GUSTS
POSSIBLE IN STRONGER STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
115 AM EDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1045 PM EDT SUN AUG 9 2015
A SHORTWAVE MOVING THROUGH THE OH VALLEY REGION IS BRINGING SOME
SHOWERS TO SOUTHERN OH AND NORTHERN KY. KCVG ONLY TRACED AS THESE
PASSED...SO THESE LIKELY DO NOT AMOUNT TO MUCH MORE THAN
SPRINKLES. OTHERWISE...MODELS INDICATE ADDITIONAL CONVECTION
UPSTREAM WILL MOVE EAST AND OR DEVELOP AND MOVE EAST TO EAST
SOUTHEAST AS IT WORKS AROUND THE MID LEVEL RIDGE CENTERED OVER THE
SOUTHERN PLAINS. DUE TO UNCERTAINTY IN TIMING AND MODEL
DIFFERENCES IN EVOLUTION OF CONVECTION OVERNIGHT AND INTO THE DAY
ON MONDAY...NO CHANGES WERE MADE TO POPS TOWARD DAWN. THE ONLY
CHANGES TO POPS WERE IN THE SHORT TERM TO ACCOUNT FOR THE SHOWERS
MOVING TOWARD NE KY. OTHERWISE...HOURLY GRIDS WERE FRESHENED UP
BASED ON RECENT OBSERVATIONS AND SATELLITE TRENDS.
UPDATE ISSUED AT 820 PM EDT SUN AUG 9 2015
A MID LEVEL RIDGE OF HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH A SERIES OF SHORTWAVES MOVING THROUGH OR NEARING THE
LOWER OH VALLEY AS THEY MOVE AROUND THIS RIDGE. AT THE SAME TIME...
A SERIES OF SHORTWAVE TROUGH WILL APPROACH OR MOVE THROUGH THE
GREAT LAKES. ALL OF THIS WILL BEGIN TO CARVE OUT AN EASTERN US
TROUGH WHILE THE RIDGE BUILDS NORTH INTO THE NORTHERN ROCKIES. AT
THE SFC..AN AREA OF LOW PRESSURE WILL TRACK INTO THE LOWER GREAT
LAKES WITH THE WARM FRONT LIFTING INTO THE REGION WHILE A COLD
FRONT MOVES INTO THE LOWER OH VALLEY. OVERALL...MOISTURE AND
FORCING WILL INCREASE OVERNIGHT ACROSS THE OH VALLEY REGION...BUT
CONFIDENCE REMAINS LOW IN THE EVOLUTION OF CONVECTION OVERNIGHT.
WITH RECENT MODEL GUIDANCE STILL SUPPORTING CHANCES FOR CONVECTION
LATE TONIGHT AND SOME DISAGREEMENT AS TO WHERE CHANCES MAY BE
BEST...NO CHANGES WERE MADE TO POPS AND WEATHER ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 345 PM EDT SUN AUG 9 2015
18Z SFC ANALYSIS SHOWS HIGH PRESSURE STILL IN CONTROL OF THE
WEATHER ACROSS EAST KENTUCKY. HIGH CLOUDS ARE MOVING IN FROM THE
NORTHWEST AHEAD OF AN APPROACHING LOW PRESSURE SYSTEM WHILE
SCATTERED CU IS DISSIPATING OVER THE AREA. TEMPERATURES ARE
TOPPING OUT IN THE MIDDLE TO UPPER 80S THROUGH EAST KENTUCKY WHILE
DEWPOINTS VARY FROM THE MID 60S NORTH TO THE LOWER 70S IN THE
SOUTH WITH LIGHT AND VARIABLE WINDS.
THE MODELS ARE IN GOOD AGREEMENT WITH THE PATTERN ALOFT OVER THE
REGION. THEY ALL DEPICT KENTUCKY ON THE NORTHEAST FRINGE OF A
STRONG RIDGE CENTERED OVER CENTRAL TEXAS. THIS PLACES THE AREA IN
NORTHWEST FLOW WITH A COUPLE OF MINOR SHORTWAVES GLIDING PAST THE
CWA INTO MONDAY MORNING. THE PATTERN WILL FURTHER AMPLIFY THROUGH
THE OHIO VALLEY AND APPALACHIANS AS A TROUGH FROM CENTRAL CANADA
WILL DIVE INTO THE GREAT LAKES LATER MONDAY...SWEEPING INTO THE
OHIO VALLEY BY 12Z TUESDAY. SIGNIFICANT HEIGHT FALLS WILL SPREAD
OVER EASTERN KENTUCKY AS A RESPONSE ALONG WITH ADDITIONAL ENERGY
CLUSTERS. GIVEN THE MODEL AGREEMENT HAVE FOLLOWED THE HIGHER
RESOLUTION HRRR AND NAM12 MOST CLOSELY INITIALLY FOLLOWING WITH
WITH IDEAS FROM THE GFS AND ECMWF LATER ON IN THE SHORT TERM.
SENSIBLE WEATHER WILL FEATURE A QUIET EVENING UNDER HIGH
CLOUDS...THIN ENOUGH TO YIELD A SMALL RIDGE TO VALLEY TEMPERATURE
SPLIT. THE CLOUDS WILL THICKEN UP DURING THE EARLY MORNING HOURS
WITH A SEMI-ORGANIZED AREA OF SHOWERS AND THUNDERSTORMS
POTENTIALLY MOVING INTO THE AREA DURING THE PRE-DAWN HOURS FROM
NORTHWEST TO SOUTHEAST. THIS MAY STABILIZE THE ENVIRONMENT FOR A
TIME BEFORE INSTABILITY BUILDS ENOUGH FOR ANOTHER ROUND OF
ACTIVITY LATER IN THE DAY MONDAY. FROM EITHER OF THESE ROUNDS OF
CONVECTION A STORM OR TWO COULD GET STRONG ENOUGH TO MAKE DAMAGING
WIND GUSTS A POTENTIAL THREAT - WILL ADDRESS THIS IN THE
FORTHCOMING HWO. THIS SYSTEM/S COLD FRONT WILL PASS THROUGH LATER
MONDAY NIGHT WITH A LINGER SHOT AT SHOWERS OR STORMS AS IT EXITS
EARLY TUESDAY MORNING. DUE TO THE CLOUD COVER TONIGHT AND MONDAY
NIGHT HAVE KEPT FOG TO A MINIMUM IN THE GRIDS...BUT IT COULD BE
MORE SUBSTANTIAL TUESDAY MORNING SHOULD THE CLOUDS AND PCPN MANAGE
TO CLEAR OUT EARLIER MONDAY NIGHT.
AGAIN USED THE SHORTBLEND GUIDANCE AS A STARTING POINT THROUGH
THE FIRST PART OF THE FORECAST FOR THE T/TD/WIND GRIDS WITH A
SWITCH TO THE SUPERBLEND FOR THE REMAINDER. DID MAKE SOME
MINOR CHANGES TO LOWS TONIGHT BASED ON THE TERRAIN WITH A SMALL
RIDGE TO VALLEY SPLIT EXPECTED INTO THE EARLY MORNING HOURS. AS
FOR POPS...ENDED UP CLOSEST TO THE MET NUMBERS THROUGH THE
PERIOD.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 313 PM EDT SUN AUG 9 2015
THE MAJORITY OF THE EXTENDED LOOKS TO BE DRY AND PLEASANT WITH
SHOWERS AND STORMS AFFECTING EASTERN KENTUCKY DURING THE DAY ON
TUESDAY...AND BELOW NORMAL TEMPERATURES TUESDAY THROUGH FRIDAY.
MOIST UPSLOPE FLOW BEHIND A DEPARTING WEATHER SYSTEM WILL ALLOW
PRECIPITATION TO LINGER ACROSS THE AREA THROUGH LATE TUESDAY
AFTERNOON. THE PRECIPITATION WILL BE USHERED OUT OF EASTERN KENTUCKY
AS A STRONG RIDGE OF HIGH PRESSURE BEGINS BUILDING INTO THE AREA
FROM THE WEST. THIS FEATURE WILL BRING DRY CONDITIONS AND COOLER
THAN NORMAL TEMPERATURES TO EAST KENTUCKY FOR THE REST OF THE
WEEK...AS A COOL AND DRY AIR MASS MOVES FROM THE NORTHERN ROCKY
MOUNTAIN REGION AND INTO THE OHIO AND TENNESSEE VALLEY REGIONS.
HIGH TEMPERATURES ON WEDNESDAY AND THURSDAY ARE EXPECTED TO MAX OUT
IN THE UPPER 70S FOR MOST LOCATIONS...WITH LOWER 80S FOR HIGHS ON
TAP FOR TUESDAY AND FRIDAY. OVERNIGHT LOWS MAY FALL AS LOW AS THE
MID TO UPPER 50S WEDNESDAY NIGHT AND THURSDAY NIGHT AS CLEAR SKIES
AND NEAR CALM WINDS REMAIN IN PLACE. MINIMUM READINGS ARE EXPECTED
TO BOTTOM OUT IN THE 60S THE OTHER NIGHTS OF THE UPCOMING WORK
WEEK...WITH LOW TO MID 60S EXPECTED FOR FRIDAY NIGHT AND SATURDAY
NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 115 AM EDT MON AUG 10 2015
VFR CONDITIONS PREVAIL ACROSS EASTERN KY THIS OVERNIGHT HOUR.
THERE ARE A FEW SHOWERS AND SPRINKLES THAT HAVE DEVELOPED ACROSS
PORTIONS OF THE REGION...SO DID GO WITH SOME VCSH AT MOST
SITES. HOWEVER SITES SHOULD REMAIN VFR THROUGH MUCH OF THE
BEGINNING OF THE PERIOD. UPSTREAM MCS RELATED CONVECTION IN
WESTERN KY HAS BEEN ON A WEAKENING TREND AND WILL PROBABLY MISS
THE REGION IN GENERAL. OTHERWISE THINK THE BETTER CONVECTION WILL
DEVELOP LATER MORNING INTO THE AFTERNOON HOURS. THEREFORE STAYED
CLOSE TO THE PREVIOUS FORECAST WITH TEMPO GROUP TO EXPRESS DROPS
TO MVFR/IFR AT TIMES TOMORROW AFTERNOON AND EARLY EVENING. WINDS
WILL BE GENERALLY LIGHT THROUGH THE PERIOD WITH HIGHER GUSTS
POSSIBLE IN STRONGER STORMS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JP
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1217 PM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /16Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SCA OVER THE OCEAN HAS BEEN CANCELLED AS SEAS HAVE FAILED TO STAY
UP NEAR 5 FT. OTHER SCA OVER THE BAY REMAINS IN PLACE AND MAY HAVE
TO ISSUE OTHER HEADLINES WITH THIS AFTERNOONS FORECAST PACKAGE.
PREVIOUS DISCUSSION...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD STATEMENT HAS BEEN ISSUED FOR THE BAY SIDE OF THE
LWR MD ERN SHORE THRU MIDDAY...SPECIFICALLY FOR BISHOPS HEAD WHERE
LEVELS ARE EXPECTED TO BE ABOUT A TENTH OF A FOOT BLO MINOR FLOOD
THRESHOLDS.
PREVIOUS DISCUSSION...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MAS/MPR
TIDES/COASTAL FLOODING...MAS/MPR
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1008 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
A COASTAL FLOOD STATEMENT HAS BEEN ISSUED FOR THE BAY SIDE OF THE
LWR MD ERN SHORE THRU MIDDAY...SPECIFICALLY FOR BISHOPS HEAD WHERE
LEVELS ARE EXPECTED TO BE ABOUT A TENTH OF A FOOT BLO MINOR FLOOD
THRESHOLDS.
PREVIOUS DISCUSSION...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...MPR/MAS
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
954 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A QUICK UPDATE THIS MORNING TO FOCUS SHOWER COVERAGE ACROSS THE
SRN PIEDMONT...SCNTRL VA...AND SRN RICHMOND METRO AREAS THROUGH
THE REST OF THIS MORNING BEFORE SHOWERS DISSIPATE.
PREVIOUS DISCUSSION (651 AM)...RADAR TRENDS INDICATE SHOWERS
HOLDING TOGETHER BETTER THAN EXPECTED OVER AN INCREASINGLY MOIST
AIR MASS. LATEST RAP GUIDANCE DEPICTS WEAK VORT MAX OVER THE
REGION...PROVIDING SUBTLE FORCING OVER AN AREA OF ISENTROPIC
LIFT...HELPING DRIVE THE SHOWERS. THIS LIFT IS PROGGED TO SPREAD
NEWD ACROSS CENTRAL VA THRU MID MORNING. HIGH PRESSURE ALONG THE
COAST WILL BEGIN TO WIN OUT...HELPING ERODE THE SHOWERS AS THEY
SPREAD EAST OF INTERSTATE 95. MID LEVEL CLOUDS HAVE ALSO
OVERSPREAD THE AREA...RESULTING IN A MOSTLY CLOUDY SKY (PARTLY
CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND LATEST STATISTICAL
GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS THE PIEDMONT INTO
CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREVIOUS DISCUSSION (407 AM)...LATEST REGIONAL RADAR MOSAIC
DEPICTS AN AREA OF SHOWERS OVER THE ERN VA PIEDMONT EARLY THIS
MORNING...SLOWING SPREADING EWD. THIS IN ASSOCIATION WITH AN AREA
OF ISENTROPIC LIFT AND WEAKENING ENERGY ALOFT. EXPECT THIS AREA OF
SHOWERS TO DISSIPATE AS IT SPREADS EWD INTO THE LOCAL PIEDMONT
COUNTIES AS THE ENERGY ALOFT WEAKENS. HOWEVER...CLOUD COVER WILL
CONTINUE TO OVERSPREAD MUCH OF THE AREA THIS MORNING...RESULTING
IN A MOSTLY CLOUDY SKY. OTHERWISE...MID- LEVEL HEIGHT FALLS OVER
THE MID- ATLANTIC REGION HAS ALLOWED MOISTURE TO RETURN EARLY THIS
MORNING...WITH PWATS PROGGED AROUND 1.5 TO 1.8 INCHES AND
DEWPOINTS WARMING INTO THE MID 60S. AT THE SFC...HIGH PRESSURE HAS
ALIGNED ALONG THE COAST WITH A WARM FRONT LOCATED OVER THE OH/KY
VALLEYS. A COLD FRONT IS RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUE AFTERNOON...WHICH
WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR THUNDER.
STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED AROUND 1K
J/KG TUE AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE 20 TO 30
KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG WITH
LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TSCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTENT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTENT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/BMD/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...AKQ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
651 AM EDT MON AUG 10 2015
.SYNOPSIS...
A COLD FRONT APPROACHES FROM THE NORTHWEST TODAY...CROSSING THE
MID ATLANTIC TONIGHT INTO TUESDAY. HIGH PRESSURE RETURNS
WEDNESDAY...REMAINING OVER THE REGION INTO THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATE...
RADAR TRENDS INDICATE SHOWERS HOLDING TOGETHER BETTER THAN
EXPECTED OVER AN INCREASINGLY MOIST AIR MASS. LATEST RAP GUIDANCE
DEPICTS WEAK VORT MAX OVER THE REGION...PROVIDING SUBTLE FORCING
OVER AN AREA OF ISENTROPIC LIFT...HELPING DRIVE THE SHOWERS. THIS
LIFT IS PROGGED TO SPREAD NEWD ACROSS CENTRAL VA THRU MID MORNING.
HIGH PRESSURE ALONG THE COAST WILL BEGIN TO WIN OUT...HELPING
ERODE THE SHOWERS AS THEY SPREAD EAST OF INTERSTATE 95. MID LEVEL
CLOUDS HAVE ALSO OVERSPREAD THE AREA...RESULTING IN A MOSTLY
CLOUDY SKY (PARTLY CLOUDY SOUTHEAST). BASED ON CURRENT PRECIP AND
LATEST STATISTICAL GUIDANCE...HAVE LOWERED TEMPS A FEW DEGS ACROSS
THE PIEDMONT INTO CENTRAL VA. HIGHS IN THE LOW TO MID 80S.
PREV DISCUSSION...
LATEST REGIONAL RADAR MOSAIC DEPICTS AN AREA OF SHOWERS OVER THE
ERN VA PIEDMONT EARLY THIS MORNING...SLOWING SPREADING EWD. THIS
IN ASSOCIATION WITH AN AREA OF ISENTROPIC LIFT AND WEAKENING
ENERGY ALOFT. EXPECT THIS AREA OF SHOWERS TO DISSIPATE AS IT
SPREADS EWD INTO THE LOCAL PIEDMONT COUNTIES AS THE ENERGY ALOFT
WEAKENS. HOWEVER...CLOUD COVER WILL CONTINUE TO OVERSPREAD MUCH OF
THE AREA THIS MORNING...RESULTING IN A MOSTLY CLOUDY SKY.
OTHERWISE...MID- LEVEL HEIGHT FALLS OVER THE MID- ATLANTIC REGION
HAS ALLOWED MOISTURE TO RETURN EARLY THIS MORNING...WITH PWATS
PROGGED AROUND 1.5 TO 1.8 INCHES AND DEWPOINTS WARMING INTO THE
MID 60S. AT THE SFC...HIGH PRESSURE HAS ALIGNED ALONG THE COAST
WITH A WARM FRONT LOCATED OVER THE OH/KY VALLEYS. A COLD FRONT IS
RIGHT ON ITS HEELS OVER THE MIDWEST.
FOR TODAY...A MORE POTENT SHORTWAVE TROUGH APPROACHES THE REGION
FROM THE NW AS THE PARENT TROUGH CONTINUES TO DIG OVER THE ERN
GREAT LAKES. THE MIDWEST COLD FRONT REACHES THE OH VALLEY LATE
TODAY. EXPECT MOSTLY CLOUDY...BUT GENERALLY DRY CONDITIONS THIS
MORNING. WILL MAINTAIN SLIGHT CHANCE POPS OVER THE PIEDMONT DUE TO
THE AFOREMENTIONED WEAKENING WAVE AND ISENTROPIC LIFT. HIGH PRESSURE
PUSHES OFFSHORE THIS AFTERNOON...OPENING THE DOOR FOR BETTER
MOISTURE RETURN. H85 FLOW INCREASES...WITH PWATS PROGGED TO REACH ~2
INCHES THIS AFTERNOON. SHOWERS AND THUNDERSTORMS ARE EXPECTED TO
DEVELOP OVER THE HIGHER TERRAIN THIS AFTERNOON ALONG THE WARM FRONT
AND LEAD SHORTWAVE...SPREADING EWD DURING THE LATE AFTERNOON. HAVE
RETAINED CHANCE POPS GENERALLY ALONG AND WEST OF INTERSTATE
95...BUMPING UP TO LIKELY IN THE NW PIEDMONT COUNTIES. ERN PORTIONS
WILL LIKELY BECOME PARTLY TO MOSTLY SUNNY BY AFTERNOON...WHILE WRN
PORTIONS REMAIN MOSTLY CLOUDY. THIS WILL KEEP HIGHS IN THE LOW 80S
THERE...WHILE AREA FARTHER EAST RISE INTO THE MID/UPPER 80S. LOUISA
AND FLUVANNA COUNTIES MAY STRUGGLE TO GET OUT OF THE UPPER 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
STRONGER FORCING ARRIVES TONIGHT AS THE TROUGH CONTINUES TO DIG
SOUTHEAST AND THE WIND FIELD STRENGTHENS ALOFT. THE WARM FRONT
CROSSES THE REGION EARLY TONIGHT AS THE COLD FRONT LOCATES CENTRAL
APPALACHIANS. A WARM/HUMID AND MARGINALLY UNSTABLE AIR MASS WILL BE
IN PLACE OVER THE LOCAL AREA AHEAD OF THE WARM FRONT. THE RESULT
WILL BE WIDESPREAD SHOWERS AND EMBEDDED THUNDERSTORMS. LIKELY POPS
HAVE BEEN RETAINED. LATEST SREF GUIDANCE CONTINUES TO INDICATE
STRONG MOISTURE FLUX (ON THE ORDER OF +4 TO +5 STD DEV) OVERNIGHT.
HEAVY RAIN WORDING HAS BEEN RETAINED DUE TO THE COMBINATION OF
STRONG FORCING AND MOISTURE FLUX. MBE/CORFIDI VECTORS AND FLOW
INDICATE GOOD STORM MOTION...WHICH WILL LIMIT THE FLOODING
POTENTIAL. FFG HAS ALSO RECOVERED FOLLOWING LAST WEEKS RAINFALL.
MARGINAL SHEAR MAY PRODUCE SOME GUSTY WINDS UNDER THE STRONGEST
STORMS. LOWS FORECAST IN THE LOW 70S.
THE COLD FRONT PUSHES ACROSS THE LOCAL AREA TUESDAY
AFTERNOON/EVENING...AND PUSHES OFFSHORE TUESDAY NIGHT. SHOWERS AND
SOME EMBEDDED TSTMS SHOULD CONTINUE TUESDAY MORNING ACROSS ERN
PORTIONS. HOWEVER...HEAVY RAIN POTENTIAL WILL DIMINISH AND THE
MOISTURE FLUX ANOMALIES RELAX. ANOTHER ROUND OF
SHOWERS/THUNDERSTORMS IS EXPECTED BY AFTERNOON AHEAD OF THE COLD
FRONT. A WARM/MOIST AIR MASS REMAINS OVER THE REGION...BUT
INSTABILITY WILL LARGELY BE LIMITED BY ANY CLEARING. MODELS AND BUFR
SOUNDINGS INDICATE A DRY SLOT/MID LEVEL DRYING TUES
AFTERNOON...WHICH WOULD RESULT IN BETTER INSTABILITY AND CHANCES FOR
THUNDER. STICKING WITH THE LATEST SREF...MLCAPE VALUES PROGGED
AROUND 1K J/KG TUES AFTERNOON. EFFECTIVE SHEAR ALSO EXPECTED IN THE
20 TO 30 KT RANGE. STRONG GUSTY WINDS WILL BE THE MAIN THREAT ALONG
WITH LOCALLY HEAVY RAINFALL. CHC POPS WILL BE CONTINUED THROUGH THE
AFTERNOON INLAND...WITH LIKELY NEAR THE COAST. TRIMMED BACK POPS
SLIGHTLY...WITH HIGHS GENERALLY IN THE MID 80S.
SHOWERS/TSTMS CONTINUE INTO TUESDAY EVENING...BEFORE TAPERING OFF NW-
SE DURING THE LATE EVENING AND OVERNIGHT HOURS. HIGH PRESSURE AND A
DRIER AIRMASS BUILDS INTO THE REGION WEDNESDAY. SOME HIGHER LOW-
LEVEL MOISTURE IS EXPECTED TO LINGER ACROSS FAR SE VA/NE NC
WEDNESDAY...SO A SLIGHT CHC POP FOR SHOWERS/TSTMS WILL BE FORECAST
FOR THESE LOCATIONS. LOWS WEDNESDAY MORNING RANGE FROM THE MID 60S
NW...TO THE LOW 70S SE. 850MB TEMPERATURES OF 14-16C SUPPORT HIGHS
IN THE LOW/MID 80S.
SREF/GEFS/WPC PROBABILITIES INDICATE HIGH PROBS FOR GREATER THAN ONE
HALF INCH RAINFALL AMOUNTS ACROSS THE ENTIRE LOCAL AREA. PROBS DROP
OFF WITH HIGHER QPF AMOUNTS...WITH ONLY A SLIGHT CHANCE OVER THE NE
COUNTIES FOR AOA 1 INCH. HOWEVER...LOCALIZED AMOUNTS GREATER THAN
ONE INCH ARE EXPECTED...ESPECIALLY UNDER STRONGER THUNDERSTORMS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION LATE WED
NIGHT INTO FRI...THUS SHUNTING THE STALLED SFC FRONT ALONG THE
CAROLINA COAST FARTHER SWD AND AWAY FROM THE FORECAST AREA.
OVERALL FORECAST WILL BE DRY WITH TEMPERATURES CLOSE TO SEASONAL
NORMALS AND GENERALLY COMFORTABLE CONDITIONS. LONG RANGE MODELS
BEGIN TO BRING UPPER LEVEL TROUGHING ACROSS THE NE CONUS ON
SAT...HOWEVER THEY DIFFER ON HOW DEEP/FAR SOUTH THE TROUGHING
EXTENDS INTO THE MID ATLANTIC REGION. LEANED TWD A DRY SOLUTION
FOR NOW WITH A SLIGHT WARMING TREND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
VFR CNDTNS XPCTD THRU MOST OF THE TAF PRD DESPITE A WEAK DISTURBANCE
MOVING ACROSS THE RGN TDY. TCTNS SHOWING PLNTY OF MID LEVEL MSTR
WITH THIS FEATURE ALONG WITH SCT SHWRS MOVG EAST OF THE MTS THIS
MORNING. KEPT SCT TO BKN CLDS AT 5K-12K FT. HIGH RES MODELS NOW
INDCT THAT RIC SEES A FEW HRS PRD OF RAIN AT BEGINNING OF TAF PRD...
BUT CIGS AND VSBY XPCTD TO REMAIN IN MVFR TO VFR RANGE. SBY/PHF
MAY SEE SOME -RA BUT NO VSBY RESTRICTIONS XPCTD THIS MORNING.
ADDNTL SHWRS DVLP W-E AFTR 06Z AND MOVE EAST AS MSTR OVRSPRDS THE
AREA AHEAD OF APPRCHG CDFRNT.
OUTLOOK...THE COLD FRONT CROSSES THE REGION LATE TUESDAY WITH CHC
CONVECTION. DRY WEATHER RETURNS WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
SEAS SLOW TO SUBSIDE AND STILL AVG 4-5 FT GIVEN THE PERSISTANT
(ALBEIT LIGHT) ONSHORE FLOW. GIVEN THE PROGGED SWELL DRCTN...SEAS
WILL LIKELY REMAIN AT THESE LEVELS MOST OF THE DAY. THUS...HAVE
XTNDD SCA HEADLINES FOR SEAS DESPITE LIGHT ESE FLOW. THNKG IS FOR
OFFSHORE SEAS TO DROP BLO 5 FT BY TONIGHT ENDING THE CRNT SCA
HEADLINES...HOWEVER DATA SUGGESTS SEAS BLDG BACK TO NR 5 FT OUT
NEAR 20 NM ACROSS NRN CSTL WTRS TUE.
WNDS BECOME SRLY TONIGHT THEN SW ON TUE AHEAD OF APPRCHG CD FRNT.
SRLY CHANNELING NOTED IN ALL THE DATA BUT THE CHALLENGE WILL BE TO
DETERMINE WHICH AREAS SEE WNDS AT SCA LVLS. HIGHEST CONFIDENCE FOR
THIS TO OCCUR IS ACROSS THE MIDDLE CHES BAY (ANZ630) TONIGHT AND TUE
SO HAVE ISSUED SCA HEADLINES FOR THIS ZONE. CONFIDENCE NOT HIGH ENUF
TO PUT THE SRN CHES BAY IN ANY HEADLINE ATTM SO HAVE CAPPED THE
SUSTAINED WINDS AT 15 KTS AND WILL LET THE DAY SHIFT REVIEW THE 12Z
DATA TO DETERMINE IF ANY SCA`S ARE NEEDED THERE AHEAD OF THE FRNT.
CDFRNT CROSSES THE WATERS LATE TUE NIGHT SHFTG WNDS TO THE NORTH
WED. NOT MUCH OF A SURGE NOTED IN THE 12Z DATA BEHIND THE FROPA SO
NO SCA HEADLINE ANTICIPATE ATTM. HIGH PRS TO THE NORTH BLDS ACROSS
THE WTRS FOR THE REST OF THE WEEK WITH WNDS/SEAS BLO SCA THRESHOLDS.
INCREASED RIP CURRENT THREAT TO MODERATE GIVEN NEARSHORE WAVES
BTWN 3-4 FT AND A PERSISTANT ONSHORE SWELL. NOT OUT OF THE QSTN
THAT A HIGH RISK MAY BE NEEDED ACROSS THE NRN OUTER BANKS TODAY
AFTER GETTING SOME FEEDBACK FROM THE BEACH AREAS LATER THIS MORNING.
&&
.TIDES/COASTAL FLOODING...
AS EXPECTED...WATER HAVING A TUFF TIME GETTING OUT OF THE CHES BAY
WITH THE WATER LEVELS ACROSS THE MIDDLE OF THE CHES BAY REMAINED
ELEVATED DURING THE PAST HIGH TIDE CYCLE. BOTH BISHOPS HEAD AND
CAMBRIDGE TOPPED OUT JUST BLO MINOR FLOODING THRESHOLDS.
TONIGHTS HIGH TIDE CYCLE COMES CLOSE ONCE AGAIN TO MINOR FLOODING
THRESHOLDS IN SVRL AREAS OF THE CHES BAY. DESPITE TIDAL ANOMALIES
REMAINING AT 0.5 TO 1.0 FT ABOVE NORMAL OVR THE NEXT FEW HIGH TIDE
CYCLES...THE VALUES SHOULD TOP OUT BLO MINOR FLOODING THRESHOLDS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 4 PM EDT
TUESDAY FOR ANZ630.
SMALL CRAFT ADVISORY UNTIL NOON EDT TODAY FOR ANZ650-652-654.
SMALL CRAFT ADVISORY UNTIL 4 PM EDT THIS AFTERNOON FOR ANZ656-
658.
&&
$$
SYNOPSIS...AJZ/SAM
NEAR TERM...AJZ/SAM
SHORT TERM...AJZ/SAM
LONG TERM...BMD
AVIATION...MPR
MARINE...MPR
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
356 PM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 355 PM EDT MON AUG 10 2015
BEEN A SLOW EAST-SOUTHEAST PUSH TO THE COLD FRONT OVER EASTERN CWA
TODAY. SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS HAVE FIRED ALONG
AND AHEAD OF FRONT MOST OF THE DAY...ONLY CLEARING KESC/KISQ/KERY
WITHIN LAST COUPLE HOURS. MOST LIGHTNING WITH ANY CELLS HAS BEEN
OVER BAY OF GREEN BAY NEAR SHORELINE OF MENOMINEE COUNTY. SCATTERED
CU LEFT IN WAKE OF FRONT ELSEWHERE...THOUGH STRATUS AND FOG IS OVER
EASTERN LK SUPERIOR AND ADJACENT SHORELINE FROM HARVEY TO MUNISING
TO GRAND MARAIS AND WHITEFISH POINT. VISIBLE SATELLITE AND MODEL
GUIDANCE POINT TO FOG SHIRNKING IN COVERAGE THROUGH THE EVENING AND
EVENTUALLY DISIPPATING OVERNIGHT. DENSE FOG ADVISORY FOR EASTERN LK
SUPERIOR GOES UNTIL 11 PM THIS EVENING. EVENING SHIFT CAN ALTER THAT
HEADLINE TIMING BASED ON OBSERVATION TRENDS.
LOOKING UPSTREAM OVER NORTHERN ONTARIO...A SHORTWAVE IS DROPPING
TOWARD THUNDER BAY AND ISLE ROYALE. ENVIRONMENT CANADA/NWS DLH/NWS
MQT COMPOSITE RADAR LOOP SHOWS NUMEROUS SHRA AND SOME TSRA SPILLING
TOWARD ISLE ROYALE...BUT GREATER COVERAGE IS STAYING UPSTREAM. WILL
CARRY SCATTERED SHOWERS AND THUNDERSTORMS OVER ISLE ROYALE INTO THE
EVENING. NAM AND GEM-REGIONAL AND THE HRRR INDICATE REMNANTS OF THE
UPSTREAM SHOWERS MAY REACH WEST AND NORTHWEST CWA THIS EVENING. AT
THE LEAST...WILL SEE SCT-BKN MID CLOUDS. REST OF OVERNIGHT APPEARS
QUIET. GRADIENT NORTH TO NORTHWEST WINDS BETWEEN HIGH PRESSURE FM
NORTHERN MANITOBA TO THE NORTHERN PLAINS AND LOW OVER JAMES BAY
SHOULD RESTRICT IDEAL RADIATIONAL COOLING AND SIGNIFICANT FOG
POTENTIAL. COULD SEE PARTCHY FOG THOUGH WHERE THERE WAS SOME RAIN
TODAY.
MAIN ISSUE ON TUESDAY WILL BE LOW CLOUDS. CONSENSUS OF SHORT RANGE
MODELS TRENDING TOWARD GREATER CLOUD COVER AND BASED ON WIDESPREAD
STRATUS OVER NORTHERN ONTARIO THIS AFTN THAT IS FORECAST TO SETTLE
SOUTHWARD INTO TUESDAY...THE TREND MAKES A LOT OF SENSE. BUMPED UP
SKY COVER AND ALSO KEPT SMALL MENTION OF DRIZZLE MAINLY IN THE
MORNING FOR NCNTRL UPR MICHIGAN WITH NORTHERLY UPSLOPE FLOW. GUSTY
NORTH-NORTHWEST WINDS...POSSIBLY UP TO 25 MPH...WILL ALSO CAUSE SOME
IMPACT...MAINLY TO MARINE INTERESTS ALONG LK SUPERIOR SHORE TO EAST
OF BIG BAY AND MARQUETTE AND ALSO ON BAY OF GREEN BAY AND NORTHERN
LK MICHIGAN. THERMAL TROUGH AT H85 OVER THE AREA SHOULD ALLOW
STRATUS AND STRATOCU CLOUDS TO PERSIST THROUGH MUCH OF THE DAY.
TEMPS COOLEST NEAR LK SUPERIOR EAST OF MARQUETTE WITH LOW 60S.
TEMPS OVER SCNTRL CWA COULD STILL REACH MID 70S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 355 PM EDT MON AUG 10 2015
NW WINDS UP TO 20 KTS ARE EXPECTED THROUGH TUESDAY. STRONGEST PUSH
OF WINDS WILL OCCUR TONIGHT INTO TUESDAY MORNING OVER EAST HALF.
DENSE FOG WILL GRADUALLY DIMINISH BY OVERNIGHT TONIGHT. ARRIVAL OF
SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE NIGHT/WED.
WINDS WILL THEN INCREASE UP TO 20 KTS OUT OF THE SW INTO THU AHEAD
OF THE NEXT APPROACHING COLD FRONT. WINDS WILL DIMINISH TO LESS
THAN 15 KTS ON FRI AS HIGH PRESSURE BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...SRF
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
316 PM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 316 PM EDT MON AUG 10 2015
AT THE START OF THE LONG TERM PERIOD THE UPPER GREAT LAKES REGION
WILL BE UNDER NORTHWESTERLY FLOW ALOFT...AS AN UPPER TROUGH WILL BE
LOCATED OVER WESTERN QUEBEC AND AN UPPER RIDGE OVER THE U.S.
ROCKIES AND CANADIAN PRAIRIES. THIS NORTHWESTERLY FLOW ALOFT WILL
PERSIST THROUGH MUCH OF THE LONG TERM PERIOD...AS THE QUEBEC TROUGH
IS RE-ENFORCED BY WAVE THE CURRENTLY OVER SOUTHEAST ALASKA. THAT
WILL LEAD TO A COUPLE OPPORTUNITIES FOR SHOWERS/THUNDERSTORMS BUT
HIGH PRESSURE WILL CONTROL MUCH OF THE LONG TERM FORECAST.
A RIDGE WILL BE OVER THE UPPER GREAT LAKES AT THE START OF THE
PERIOD...FROM A HIGH IN THE CENTRAL MISSISSIPPI VALLEY...WHICH WILL
LEAD TO A MOSTLY CLEAR START TO TUESDAY NIGHT. THAT WILL BE SHORT
LIVED...AS A WEAK SHORTWAVE DIVES SOUTHEAST OUT OF FAR WESTERN
ONTARIO AND ACROSS NORTHWESTERN LAKE SUPERIOR. EXPECT SHOWERS AND
MAYBE A FEW THUNDERSTORMS TO BE ASSOCIATED WITH THIS WAVE...AS
THERE IS DECENT 925-700MB WARM AIR ADVECTION WITH IT. THIS SHOULD
ARRIVE LATE IN THE NIGHT TOWARDS THE KEWEENAW AND THEN SHIFT
SOUTHEAST THROUGH THE CENTRAL U.P. DURING THE DAY ON WEDNESDAY.
MODELS ARE SHOWING ENOUGH OF A SIGNAL IN WITH THE WARM AIR
ADVECTION TO TREND POPS UP TO CHANCES FOR PARTS OF THE AREA ON
WEDNESDAY. WHILE MUCAPE VALUES ARE NOT OVERLY IMPRESSIVE LATE
TUESDAY NIGHT INTO WEDNESDAY...THINK THE STEEPENING LAPSE RATES ON
THE WESTERN EDGE OF THE WARM AIR ADVECTION WOULD SUPPORT THERE
BEING SOME THUNDERSTORMS AND HAVE ADDED A SLIGHT CHANCE OF THUNDER
ALONG THE WESTERN EDGE OF THE POPS.
WHILE THAT WAVE WILL QUICKLY SLIDE TO THE SOUTHEAST...THEN NEXT
WAVE AND ASSOCIATED COLD FRONT (FROM A LOW MOVING THROUGH NORTHERN
ONTARIO) WILL MOVE SOUTHEAST THROUGH THE CWA LATE WEDNESDAY NIGHT
AND THURSDAY. THERE ARE STILL SOME TIMING DIFFERENCES IN THE
MODELS...WITH THEM SPEEDING IT UP SOME FROM PREVIOUS RUNS. THIS
WILL LIKELY PUSH THE FRONT AND A BULK OF THE PRECIPITATION THROUGH
THE AREA ON THURSDAY MORNING AND INTO EARLY THURSDAY AFTERNOON.
WILL SHOW CHANCE POPS MOVING THROUGH THE AREA DURING THAT
PERIOD...WITH THE HIGHEST NEAR THE LAKE MICHIGAN SHORELINE WITH THE
ADDED HELP OF DIURNAL HEATING. WILL HAVE THUNDER CHANCES FOLLOW THE
POPS...AS THERE ARE FAIRLY STEEP LAPSE RATES (7 C/KM OR HIGHER)
ALONG AND AHEAD OF THE FRONT. IF THE FRONT MOVES THROUGH A LITTLE
SLOWER...THERE WOULD BE ENOUGH SHEAR TO SUPPORT STRONGER
THUNDERSTORMS OVER THE SOUTHEASTERN U.P. ON THURSDAY AFTERNOON.
BEHIND THE COLD FRONT...THERE ARE SOME HINTS IN THE MODELS OF A
VERY WEAK SHORTWAVE BRUSHING THE AREA ON THURSDAY
NIGHT...OTHERWISE...HIGH PRESSURE FROM THE CANADIAN PRAIRIES WILL
MOVE SOUTHEAST OVER THE UPPER GREAT LAKES REGION ON FRIDAY AND
REMAIN INTO SATURDAY. THAT SHOULD LEAD TO A NICE COUPLE OF DAYS IN
THE U.P. WITH HIGHS IN THE 70S TO AROUND 80 DEGREES WITH AFTERNOON
LAKE BREEZES. THE HIGH WILL START TO SHIFT TO THE SOUTHEAST ON
SATURDAY NIGHT AS THE UPPER RIDGE AXIS CROSSES THE UPPER GREAT LAKES
REGION. BEHIND THAT UPPER RIDGE...ANOTHER TROUGH WILL MOVE THROUGH
THE AREA FOR LATER SUNDAY AND INTO SUNDAY NIGHT AND WILL SPREAD
CHANCE POPS EAST ACROSS THE AREA FOR THAT TIME FRAME. AT THIS
TIME...MODELS ARE CONSISTENT ON IT QUICKLY SHIFTING EAST AND
LEADING TO A MAINLY DRY MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...SRF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
147 PM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 146 PM EDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH TAF PERIOD AT KIWD AND KCMX. SCT-MID
CLOUDS WILL AFFECT BOTH SITES AT TIMES...ESPECIALLY TONIGHT AS SHRA
DISSIPATE WHILE MOVING OUT OF NORTHEAST MN AND NORTHERN ONTARIO. AT
KSAW...VFR CONDITNONS SHOULD PREVAIL UNTIL LATE TONIGHT WHEN LOW
CLOUDS CURRENTLY OVER NORTHERN ONTARIO DROP ACROSS LK SUPERIOR AND
MOVE INTO NORTHERN UPR MICHIGAN ON NORTH WINDS. CIGS SHOULD SETTLE
INTO LOW MVFR RANGE AROUND SUNRISE ON TUESDAY...WITH SOME POTENTIAL
OF IFR CIGS THROUGH TUE MORNING. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
DENSE FOG ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LSZ249>251-
266-267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
734 AM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 733 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT THAT HAS PASSED...VFR CONDITIONS SHOULD
PREVAIL THRU THE FCST PERIOD AT KIWD/KCMX/KSAW. THERE MAY BE A BRIEF
PERIOD OF HIGH MVFR CIGS THIS MORNING AS DAYTIME HEATING LEADS TO
CUMULUS DEVELOPMENT...AND THEN NEAR OR JUST AFTER THIS FCST
PERIOD...THERE ARE SOME INDICATIONS THAT LOW CLOUDS (LOW MVFR
CIGS/PERHAPS IFR) MAY DEVELOP...MAINLY AT KSAW. AN APPROACHING
DISTURBANCE WILL GENERATE SHOWERS NW OF LAKE SUPERIOR TODAY. SOME OF
THESE SHOWERS MAY BE ABLE TO REACH UPPER MI LATE THIS AFTN/EARLY
THIS EVENING BEFORE DISSIPATING. POTENTIAL OF THESE SHRA REACHING
ANY OF THE TERMINALS (KCMX IN PARTICULAR) IS TOO LOW TO INCLUDE A
MENTION IN FCST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
509 AM EDT MON AUG 10 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 509 AM EDT MON AUG 10 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A RIDGE OVER THE ROCKIES
WITH DOWNSTREAM TROF BEGINNING TO DEEPEN FROM HUDSON BAY S INTO THE
GREAT LAKES. IN THE DEVELOPING NW FLOW INTO THE GREAT LAKES...THERE
IS ONE SHORTWAVE OF NOTE UPSTREAM E OF LAKE WINNIPEG ALONG THE
ONTARIO/MANITOBA BORDER. CLOSER TO HOME...SCT SHRA CONTINUE EARLY
THIS MORNING OVER ROUGHLY THE E HALF UPPER MI...AHEAD OF COLD FRONT.
WILL CONTINUE TO CARRY SCT SHRA OVER THE ERN FCST AREA THIS MORNING
AHEAD OF SLOW MOVING COLD FRONT. MIGHT BE A FEW RUMBLES OF THUNDER.
WHERE CLOUDS SCATTER OUT...EXPECT SOME FOG UNTIL MID MORNING...
ESPECIALLY IN THOSE AREAS WHERE RAINFALL HAS OCCURRED OVER THE LAST
12HRS. THIS AFTN...UNDER NNW FLOW...LAKE BREEZE COMPONENTS TO WIND
WILL LEAD TO AN AREA OF CONVERGENCE IN SCNTRL UPPER MI. WITH
POTENTIAL OF 50-200J/KG OF MLCAPE PER GFS/RAP/HRRR...ISOLD SHRA/TSTM
MAY DEVELOP (NAM LOOKS WAY TOO HIGH WITH MLCAPES OVER 1000J/KG).
WITH MOST OF THE HIGH RES MODEL GUIDANCE SHOWING SOME CONVECTION IN
THAT AREA...WILL INCLUDE SCHC TO LOW CHC POPS IN SCNTRL UPPER MI
THIS AFTN. AHEAD OF THE LAKE BREEZE OFF LAKE SUPERIOR...MAY SEE A
FEW SHRA/TSRA E TOWARD KISQ/KERY AS WELL. AS SHORTWAVE CURRENTLY E
OF LAKE WINNIPEG DROPS SE...REACHING WRN LAKE SUPERIOR THIS
EVENING...THERE SHOULD BE QUITE A BIT OF SHRA AND SOME TSTMS
DEVELOPING NW OF LAKE SUPERIOR THIS AFTN. THIS CONVECTION WILL
SPREAD OUT OVER NW LAKE SUPERIOR IN THE AFTN. NOT SURE HOW FAR THIS
ACTIVITY WILL SPREAD BEFORE DISSIPATING OVER THE COOLER MARINE
LAYER. HOWEVER...WITH WATER NOT AS COLD AS EARLIER IN THE SUMMER AND
WITH SUPPORT FROM DECENT LOOKING SHORTWAVE...SOME OF THIS ACTIVITY
CERTAINLY HAS THE POTENTIAL TO SURVIVE IN A WEAKENED STATE INTO NW
UPPER MI LATE THIS AFTN/EARLY EVENING.
ANY -SHRA THAT SURVIVE THE TRIP ACROSS THE LAKE INTO NW UPPER MI
WILL DISSIPATE THIS EVENING AS SHORTWAVE QUICKLY MOVES E OF THE
AREA. THIS WILL LEAD TO A QUIET OVERNIGHT. SINCE GFS AND ESPECIALLY
NAM SUGGEST AN INCREASE IN LOW CLOUDS OCCURRING LATE IN THE NIGHT
INTO TUE MORNING...CLOUD COVERAGE WAS TRENDED UP OVERNIGHT...
ESPECIALLY ACROSS THE N WHERE UPSLOPE WIND SHOULD AID CLOUD
DEVELOPMENT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 509 AM EDT MON AUG 10 2015
IN THE WAKE OF A COLD FRONT CROSSING THE UPPER LAKES...W TO NW WINDS
WILL BEGIN TO INCREASE TODAY ACROSS LAKE SUPERIOR...THOUGH WINDS
WILL REMAIN UNDER 20KT. ANY FOG OVER THE LAKE SHOULD GRADUALLY
DISSIPATE. TONIGHT/TUE...PRES GRADIENT TIGHTENS A BIT AHEAD OF
APPROACHING SFC HIGH PRES...SO WINDS OVER THE E HALF OF LAKE
SUPERIOR WILL PROBABLY BEGIN TO GUST MORE FREQUENTLY TO AROUND 20KT.
ARRIVAL OF SFC HIGH PRES RIDGE WILL RESULT IN WINDS UNDER 15KT TUE
NIGHT/WED. WINDS WILL THEN INCREASE TO 10-20KT OUT OF THE SW INTO
THU AHEAD OF THE NEXT APPROACHING COLD FRONT. DEPENDING HOW MUCH THE
PRES GRADIENT TIGHTENS...WILL NEED TO WATCH FOR THE POTENTIAL OF
WINDS TO INCREASE FURTHER INTO THE 15-25KT RANGE...WITH PERHAPS
GUSTS TO 30KT AT THE HIGHEST OBS PLATFORMS. WINDS WILL DIMINISH
AFTER THE FRONT PASSES. EXPECT LIGHTER WINDS UNDER 15KT ON FRI AS
HIGH PRES BUILDS INTO THE UPPER LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...JLB
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
240 AM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 240 AM EDT MON AUG 10 2015
THE 500MB TROUGH SET UP ACROSS MUCH OF EASTERN CANADA AND THE
EASTERN US. THE LAST SHORTWAVE OVER W LAKE SUPERIOR AT 12Z TUESDAY
WILL EXPAND ACROSS E UPPER MI THROUGH THE AFTERNOON AND EVENING
HOURS. WHILE THIS AND THE STEADY N-NNW WINDS WILL KEEP CLOUDS STUCK
OVER THE E HALF...LINGERING PRECIP IS STILL UNKNOWN ESPECIALLY WITH
PW VALUES DIMINISHING THROUGH FROM A MAX OF AROUND 1.25 EARLY IN THE
DAY TO AROUND 1 IN BY MID AFTERNOON TUESDAY.
THE SFC HIGH STRETCHING FROM HUDSON BAY DOWN THROUGH THE CENTRAL
PLAINS TUESDAY MORNING WILL SETTLE ACROSS THE CWA BY 06Z WEDNESDAY.
THE CANADIAN/ECMWF/AND GFS ARE ALL BRINGING IN ADDITIONAL PRECIP
WEDNESDAY ASSOCIATED WITH A WARM FRONT EXTENDING FROM A LOW WAY UP
IN N CENTRAL CANADA. THIS WILL COINCIDE WITH THE SFC RIDGE SHIFTING
SLIGHTLY TO THE SE. THE NAM IS LESS IMPRESSIVE...AND HAS ONLY
INCREASED CLOUD COVER. GIVEN THE OVERALL LIMITED MOISTURE...WILL
KEEP POPS TO A MINIMUM.
THE SFC LOW WILL SHIFT E AND STRETCH FROM N CANADA THROUGH HUDSON
BAY BY THURSDAY AFTERNOON...WITH THE COLD FRONT SET UP ACROSS
ONTARIO...NW LAKE SUPERIOR AND CENTRAL MN. LOOK FOR A BETTER CHANCE
OF SHOWERS THURSDAY AS THE FRONT ROLLS THROUGH...SHIFTING SE OF THE
CWA BY MID MORNING FRIDAY. INCREASED WIND GUSTS A BIT MORE DUE TO
INCREASED MIXING AROUND THE COLD FRONT.
LOOK FOR HIGH PRESSURE TO QUICKLY BUILD IN FRIDAY...AND REMAIN
THROUGH SATURDAY...WITH DRY WEATHER FIGURED. WAA WILL BEGIN AGAIN
SATURDAY NIGHT AS THE LARGE AREA OF HIGH PRESSURE SHIFTS E. THE
ECMWF IS QUICKER TO HAVE THE HIGH SHIFT E IN ADVANCE OF THE NEXT
CANADIAN LOW AND ASSOCIATED COLD FRONT FOR SUNDAY-MONDAY. WILL GO
WITH A GENERAL BLEND FOR THE WEEKEND ON THE TIMING. WHILE TS MAY BE
MORE ALIGNED NEAR THE COLD FRONT...WILL GO WITH GENERAL SHOWERS AND
THUNDERSTORMS AT THIS POINT...WHICH WILL NEED TO BE FINE TUNED AS
THE TIME NEARS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KF
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
124 AM EDT MON AUG 10 2015
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 326 PM EDT SUN AUG 9 2015
SHOWERS AND THUNDERSTORMS CHANCES WILL INCREASE TONIGHT INTO MONDAY.
MANY AREAS SHOULD SEE AROUND A HALF INCH OF RAIN IN THIS PERIOD...
HOWEVER SEVERE WEATHER IS GENERALLY NOT EXPECTED. A FEW SHOWERS MAY
LINGER INTO MONDAY EVENING...BUT WE SHOULD GRADUALLY DRY OUT...
MAKING FOR A PLEASANT TUESDAY WITH LESS HUMIDITY.
MUCH OF THE REMAINDER OF THE WEEK LOOKS DRY WITH NEAR OR SLIGHTLY
ABOVE NORMAL TEMPERATURES...WITH DAYTIME HIGHS GENERALLY 80 TO 85.
A WIDELY SCATTERED THUNDERSTORM WILL BE POSSIBLE ON THURSDAY.
&&
.UPDATE...
ISSUED AT 1050 PM EDT SUN AUG 9 2015
I HAVE UPDATED THE FORECAST TO INCREASE THE RISK FOR THUNDERSTORMS
TOWARD MORNING OVER OUR SOUTHWEST CWA THEN SPREAD THAT CONVECTION
EASTWARD. WE ALREADY HAD LIKELY POP FOR MONDAY MORNING AFTER 8
AM...SO THIS JUST STARTS THE CONVECTION A TOUCH SOONER.
WHAT I AM SEEING FROM BOTH THE WATER VAPOR IMAGE LOOPS AND
WATCHING THE RAP MODEL HOURLY IS THAT WE HAVE A JET EXIT REGION
WITH DECENT PVU (POTENTIAL VORTICITY) IN THE 500 TO 300 MB LAYER
COMING THROUGH THE I-94 TO I-96 AREA BETWEEN 4 AM AND 9 AM THIS
MORNING. A WEAK LLJ DEVELOPS IN RESPONSE TO THIS AIMED AT AZO
BTW 8 AM AND 10 AM. SINCE THE HRRR...HRRR EXPERIMENTAL...AND
RAP13 HAVE BEEN RATHER CONSISTENT WITH THIS AND IT MAKES SENSE
GIVEN WHAT IS GOING ON NOW... I AM DID UPDATE THE GRIDS TO REFLECT
THE IDEA OF THUNDERSTORMS TOWARD MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 326 PM EDT SUN AUG 9 2015
RAIN CHANCES OVER SW MI WILL PEAK DURING THE FIRST HALF OF MONDAY AS
A COLD FRONT APPROACHES. GIVEN THE FRONT/S TIMING SEVERE WEATHER IS
GENERALLY NOT EXPECTED. WE DRY OUT MONDAY EVENING...BECOMING COOLER
AND LESS HUMID INTO TUESDAY.
A COLD FRONT WAS MOVING ACROSS THE MN/WI BORDER THIS AFTERNOON AND
HAS AN AREA OF SHOWERS AND STORMS WITH IT. THE STRONGEST AREA OF
STORMS WAS ASSOCIATED WITH THE LEFT EXIT REGION OF THE UPPER JET.
THE FRONT AND THE UPPER JET WILL MAKE IT/S WAY THROUGH THE CWA
MONDAY MORNING INTO EARLY AFTERNOON...NORMALLY A MIN TIME FOR SEVERE
WX. THIS LIKELY FAVORS AREAS TO OUR EAST FOR THE POTENTIAL OF
STRONGER STORMS. THE OTHER PARAMETER GOING AGAINST SEVERE STORMS IS
THAT THE 0-6 KM BULK SHEAR IS ONLY 20-25 KNOTS OVER SW MI AS THE
FRONT COMES THROUGH.
HOWEVER THE FRONT WILL BE HEADING INTO A JUICY AIR MASS WITH DEW
POINTS AROUND 70 ALONG I-94...AND MID TO UPPER 60S ELSEWHERE ACROSS
THE CWA. SO EXPECT THE STORMS OVER MN/WI TO HOLD TOGETHER AND
EXPAND...BRINGING A BENEFICIAL RAIN TO MOST OF THE CWA LATE TONIGHT
INTO MONDAY. RAIN TOTALS WILL VARY GREATLY GIVEN THE CONVECTIVE
NATURE...BUT MOST AREAS SHOULD SEE A HALF TO THREE QUARTERS OF INCH
OF RAIN. THE SHOWERS AND STORMS WILL END FROM WEST TO EAST WITH THE
FRONTAL PASSAGE MONDAY AFTERNOON INTO THE EVENING.
COOLER AND LESS HUMID AIR WILL FILTER IN BEHIND THE FRONT. HIGHS IN
THE 70S CAN BE EXPECTED FOR TUESDAY AS THE UPPER FLOW BECOMES
NORTHWESTERLY. OUTSIDE CHANCE THAT A FEW SHOWERS MAY POP UP ACROSS
CENTRAL LOWER TUESDAY DUE TO THE COOL AIR ALOFT. I DID NOT ADD
THIS...BUT I DID INCREASE THE CLOUD COVER IN THE FORECAST. WE
SHOULD SEE DIURNAL CU AT THE VERY LEAST...WHICH SHOULD BECOME BKN TO
OVC AT TIMES DURING THE AFTERNOON.
.LONG TERM...(WEDNESDAY THROUGH SUNDAY)
ISSUED AT 326 PM EDT SUN AUG 9 2015
FAIR WEATHER IS ANTICIPATED WEDNESDAY WITH A HIGH PRESSURE RIDGE
CENTERED OVER THE LOWER GREAT LAKES REGION STILL IN CONTROL OF THE
WX PATTERN.
IT WILL TURN WARMER AND MORE HUMID THURSDAY IN SW FLOW OUT AHEAD OF
AN APPROACHING COLD FRONT. THE COLD FRONT WILL BRING A CHANCE OF
RAIN AND THUNDERSTORMS LATE THURSDAY THROUGH THURSDAY NIGHT INTO
FRIDAY.
FAIR WX WILL RETURN BEHIND THAT SYSTEM FOR FRIDAY NIGHT THROUGH THE
WEEKEND AS A HIGH PRESSURE RIDGE BUILDS SLOWLY EAST ACROSS THE GREAT
LAKES REGION. TEMPERATURES NEXT WEEKEND WILL AVERAGE NEAR TO
SLIGHTLY ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 123 AM EDT MON AUG 10 2015
SCATTERED SHOWERS WILL CONTINUE TO DEVELOP OVERNIGHT AS SOUTH FLOW
AHEAD OF A COLD FRONT INCREASES. MVFR CIGS/VSBYS POSSIBLE PRIOR TO
AND JUST AFTER SUNRISE.
A COLD FRONT MAY TRIGGER NON SEVERE STORMS THIS
AFTERNOON...ESPECIALLY NEAR THE EASTERN TAF SITES.
&&
.MARINE...
ISSUED AT 326 PM EDT SUN AUG 9 2015
RATHER QUIET CONDITIONS ARE EXPECTED ON THE TONIGHT INTO MONDAY.
HOWEVER NORTHERLY WINDS WILL INCREASE BEHIND THE FRONT AND WAVES
WILL BEGIN TO BUILD MONDAY EVENING INTO TUESDAY. PEAK WINDS AND
WAVES SHOULD OCCUR INTO TUESDAY...AND WE MAY NEED A SMALL CRAFT
ADVISORY BY TUESDAY AFTERNOON. WINDS AND WAVES SHOULD THEN DIMINISH
LATE TUESDAY NIGHT.
&&
.HYDROLOGY...
ISSUED AT 326 PM EDT SUN AUG 9 2015
NO HYDRO IMPACTS ARE EXPECTED OVER THE NEXT WEEK. THE CHANCE FOR
SCATTERED SHOWERS WILL INCREASE THROUGH THE AFTERNOON AND ESPECIALLY
THE EVENING. RAIN CHANCES ARE HIGHEST THIS EVENING INTO MONDAY
AFTERNOON ALONG WITH THE POTENTIAL FOR ISOLATED STORMS. STORM
CHANCES WILL BE HIGHEST EARLY MONDAY AFTERNOON ACROSS THE EASTERN
FORECAST AREA. WE COULD SEE A FEW STRONG STORMS AT THAT TIME CAPABLE
OF LOCALLY HIGHER RAINFALL AMOUNTS. BUT IN GENERAL...WIDESPREAD
RAINFALL IS FORECAST TO REMAIN BELOW 0.75 INCHES AND MOST LIKELY IN
THE 0.25 TO 0.50 INCH RANGE. ANY RAINFALL TONIGHT INTO MONDAY WILL
LIKELY BE BENEFICIAL FOR MOST.
OUTLOOK...THE REST OF THE WORK WEEK LOOKS QUIET AND MAINLY DRY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...WDM
SYNOPSIS...JK
SHORT TERM...JK
LONG TERM...LAURENS
AVIATION...04
HYDROLOGY...EBW
MARINE...JK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
119 AM EDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 308 PM EDT SUN AUG 9 2015
MUCH OF THE FOCUS ON THE SHORT TERM FORECAST IS ON THE CONVECTIVE
DEVELOPMENT EXPECTED OVER THE WEST/CENTRAL U.P. IN THE NEXT FEW
HOURS AND CONTINUING INTO THE EVENING. A LARGE AREA OF MVFR CLOUDS
HAS BEEN SETUP OVER NORTHWEST WISCONSIN AND WESTERN UPPER MICHIGAN
THIS MORNING AND INTO THE EARLY AFTERNOON HOURS. THIS HAS HELPED
SUPPRESS THE DIURNAL HEATING AND HAS KEPT ML CAPE VALUES OVER THE
WESTERN THIRD OF THE U.P. BELOW 500 J/KG. FARTHER TO THE EAST AND
ALONG THE EDGE OF THE LOW CLOUDS...DIURNAL CU HAS DEVELOPED AND RAP
ANALYSIS DATA IS SHOWING 500-1000 J/KG OF ML CAPE. HAVE STARTED TO
SEE SOME SHOWERS DEVELOP IN CENTRAL IRON COUNTY AND ALSO ALONG THE
WISCONSIN BORDER SOUTH OF BESSEMER. THESE ARE OUT AHEAD OF THE COLD
FRONT STRETCHING SOUTHWEST ACROSS WESTERN LAKE SUPERIOR AND INTO
CENTRAL MINNESOTA. A SHORTWAVE HAS BEEN MOVING THROUGH CENTRAL
MINNESOTA THIS MORNING AND INTO THE EARLY AFTERNOON HOURS...WHICH
HAS BEEN THE MAIN FOCUS OF SHOWERS AND THUNDERSTORMS THUS FAR. WITH
THE SHORTWAVE EXPECTED TO CONTINUE EASTWARD...THINK THE CWA WILL
ONLY BE BRUSHED BY THE NORTHERN EDGE...BUT WITH THE SUPPORT OF THE
WEAK COLD FRONT MOVING INTO THE WESTERN U.P. STILL THINK ISOLATED TO
SCATTERED SHOWERS AND A FEW THUNDERSTORMS ARE POSSIBLE THE REST OF
THIS AFTERNOON INTO THIS EVENING. RAP MUCAPE VALUES EXCEED 1000 J/KG
OVER THE WESTERN U.P. SO THERE IS STILL SOME SUPPORT FOR STRONGER
STORMS IF THEY CAN GET GOING. UNFORTUNATELY MID CLOUDS FROM THE
SHORTWAVE ARE MASKING THE LOWER CLOUD FIELD AND IT IS MAKING IT
DIFFICULT TO SEE HOW DEVELOPMENT IS GOING...BUT AM ABLE TO MAKE OUT
SOME SCATTERING OF THE LOW CLOUDS TO THE SOUTHWEST OF MARQUETTE
COUNTY...SO THAT MAY BE ENOUGH TO GET SHOWERS DEVELOPING FURTHER AS
THEY INTERACT WITH THE BETTER INSTABILITY JUST TO THE EAST. IN
ADDITION...HAVE SEEN SOME HINTS OF A LAKE BREEZE NEAR MARQUETTE ON
OBS AND RADAR...WHICH WILL LEAD TO SOME SHOWER DEVELOPMENT. ADJUSTED
THE FORECAST EARLIER THIS MORNING WITH THE AXIS OF HIGHEST POPS
TOWARDS THAT AREA AND WILL MAKE SLIGHT ADJUSTMENTS TO THAT AREA
(SLIGHTLY TO THE WEST AND TOWARDS THE COLD FRONT) BEFORE FINAL
ISSUANCE.
THE FRONT WILL SLOWLY MOVE EAST ACROSS THE U.P. TONIGHT AND EXIT THE
NEWBERRY/MANISTIQUE AREA A COUPLE HOURS AFTER SUNRISE. A LOT OF THE
FORECAST FOR THIS EVENING WILL DEPEND ON THE DEVELOPMENT/COVERAGE OF
THE SHOWERS AND THUNDERSTORMS OVER THE WESTERN/CENTRAL U.P....BUT
THINK THE COMBINED FRONT AND SHORTWAVE WILL KEEP THE SCATTERED
SHOWER POTENTIAL PUSHING EAST THROUGH THE AREA INTO THE FIRST PART
OF THE OVERNIGHT HOURS...ESPECIALLY OVER THE CENTRAL. THEN...EXPECT
SHOWERS TO DIMINISH OVERNIGHT AS THE COLD FRONT AND WEAK SHORTWAVE
SHIFTS OFF TO THE EAST. THAT WILL LEAVE THE AREA BETWEEN THE
DEPARTING COLD FRONT AND A HIGH BUILDING INTO THE NORTHERN PLAINS.
WITH LIGHT WINDS AND PARTLY CLOUDY TO MOSTLY CLEAR SKIES BEHIND THE
FRONT...EXPECT THERE TO BE SOME FOG DEVELOPMENT
OVERNIGHT...ESPECIALLY OVER THE CENTRAL. THE WEST AND EAST THIRDS
WILL BE A LITTLE MORE UNCERTAIN...DUE TO THE POTENTIAL FOR LESS LOW
LEVEL MOISTENING FROM RAIN AND CLOUD COVER FROM THE DEPARTING
SHORTWAVE OVER THE EAST AND INCREASING LOW LEVEL NORTH-NORTHWESTERLY
FLOW OVER THE WEST.
THOSE NORTHERLY WINDS WILL INCREASE THROUGH THE MORNING TOMORROW AS
THE FRONT MOVES AWAY FROM THE AREA AND THE HIGH BUILDS INTO THE
NORTHERLY PLAINS. OVERALL...IT SHOULDN/T BE TOO WINDY WITH MOSTLY
LOCATIONS SEEING GUSTS AROUND 10-12KTS. WITH THE WINDS AIDING MIXING
AND DIURNAL HEATING...SHOULD SEE THE FOG THAT DEVELOPS OVERNIGHT
TRANSITION TO SOME DIURNAL CU THROUGH THE MORNING AND EARLY
AFTERNOON HOURS. MODELS SHOWING LIMITED MOISTURE THAT IT IS MIXING
INTO...SO WOULDN/T EXPECT THE COVERAGE TO BE MORE THAN PARTLY
CLOUDY. THERE CONTINUES TO BE INDICATIONS IN THE HIGHER RESOLUTION
MODELS THAT ISOLATED SHOWERS WILL DEVELOP OVER THE SOUTH CENTRAL IN
THE AFTERNOON AND ALSO AROUND OR JUST SOUTHEAST OF KERY. THERE IS
BETTER MOISTURE LINGERING IN THAT AREA AND INDICATIONS OF MLCAPE
VALUES RISING TOWARDS 300 J/KG. FINALLY...DEEPER MOISTURE ARRIVES
LATE IN THE DAY FROM THE NORTHWEST AS A 700-500MB TROUGH DROPS
SOUTHEAST AROUND THE DISSIPATING JAMES BAY UPPER LOW. WITH THE
STRENGTH OF THE WAVE...COULD SEE A FEW SHOWERS DROP SOUTHEAST ACROSS
NORTHWEST LAKE SUPERIOR LATE IN THE DAY AND MAYBE APPROACH THE
KEWEENAW PENINSULA. HAVE LEFT THE SLIGHT CHANCES JUST TO THE
NORTHWEST OF THE KEWEENAW FOR NOW...AS THE BEST OPPORTUNITY WOULD
COME AFTER 00Z.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 332 PM EDT SUN AUG 9 2015
A NW FLOW BTWN AN UPR RDG IN THE PLAINS AND A DOWNSTREAM TROF OVER
ERN CANADA WL DOMINATE THE GREAT LKS EARLY THIS WEEK...BRINGING A
PERIOD OF BLO NORMAL TEMPS FOR MON NGT INTO WED. WARMER WX AND A CHC
OF SHOWERS/TS WL THEN BE THE RULE ON THU IN ADVANCE OF A COLD FNT
ASSOCIATED WITH A DISTURBANCE DROPPING SEWD THRU NW ONTARIO. EXPECT
DRY AND A BIT COOLER WX LATE IN THE WEEK WITH HI PRES TRAILING THE
FNT. THE NEXT CHC OF SHOWERS/TS AND WARMER WX WL RETURN NEXT SUN
AHEAD OF THE NEXT SHRTWV/COLD FNT TOPPING THE PERSISTENT UPR RDG IN
THE PLAINS.
MON NGT...SHRTWV DIVING SEWD IN THE NW FLOW ALF BTWN PLAINS RDG AND
ERN TROF IS FCST TO DIG THRU THE AREA. SOME OF THE MODELS SHOW SOME
WEAK DEEP LYR QVECTOR CNVGC ASSOCIATED WITH THE PVA AHEAD OF THIS
DISTURBANCE AND GENERATE SOME SPOTTY LGT PCPN OVER THE AREA...MAINLY
OVER THE HIER TERRAIN NEAR LK SUP WITH UPSLOPE N WINDS. BUT ABSENCE
OF STRONGER FORCING AND ARRIVAL OF THIS DISTURBANCE DURING PERIOD OF
NOCTURNAL COOLING WL LIMIT INTENSITY AND COVERAGE OF ANY SHOWERS. DO
EXPECT MORE LO CLDS IN THESE UPSLOPE AREAS WITH AN INCRS IN LLVL RH
AS H85 TEMPS WITHIN THERMAL TROF FALL TO 8-10C BY 12Z TUE. STEADY N
WINDS WL LIMIT THE DIURNAL TEMP FALL DESPITE THE LLVL COOLING TREND.
MOST PLACES SHOULD SEE MINS IN THE 50S...WITH THE LOWER TEMPS AT THE
COOLER SPOTS OVER THE INTERIOR W HALF WHERE THE WINDS WL BE A BIT
LIGHTER CLOSER TO SFC HI PRES RDG BLDG INTO MN.
TUE/TUE NGT...EXPECT DRY WX TO PREVAIL DURING THIS TIME UNDER
CONFLUENT NW FLOW ALF/DEEP LYR QVECTOR DVGC/SUBSIDENCE LEFT IN THE
WAKE OF EXITING SHRTWV. SC IN THE UPSLOPE AREAS ON TUE MRNG SHOULD
EXPAND WITH DAYTIME HEATING UNDER THERMAL TROF...BUT CLOSER APRCH OF
SFC HI PRES FCST TO ARRIVE OVER THE W BY 00Z WED/INCRSGLY ACYC LLVL
FLOW/LOWERING SUBSIDENCE INVRN WL LIKELY RESULT IN MORE SUNSHINE W-E
THRU THE AFTN. UNDER MOCLR SKIES...TUE NGT WL BE COOL ESPECIALLY
OVER THE INTERIOR W HALF WITH LIGHTER WINDS CLOSER TO SFC HI PRES
RDG SINKING INTO WI. BUT WITH MIN PWAT NOT MUCH BLO 0.75 INCH IN
THIS AREA...DO NOT EXPECT MIN TEMPS TO BE TOO CHILLY.
WED/WED NGT...SFC HI PRES IS FCST TO SINK S INTO THE MID MS RIVER
VALLEY THRU THIS TIME. AS THE MSLP FALLS OVER NW ONTARIO IN ADVANCE
OF SHRTWV RIDING OVER THE TOP OF PLAINS RDG INTO FAR NW ONTARIO...
UPR MI WL BE DOMINATED BY AN INCRSG WSW FLOW. EXPECT SOME CLDS
ASSOCIATED WITH BAND OF INCRSG WAA/ISENTROPIC ASCENT BEST SHOWN ON
THE 300-305K SFCS TO IMPACT THE UPR LKS WED AFTN/EVNG. MANY OF THE
MODELS GENERATE SOME PCPN AS WELL...BUT RELATIVE DRYNESS OF THE
LLVLS AND MODEST PWAT FCST NEAR 1 INCH /ABOUT NORMAL/ WARRANT ONLY
LO CHC POPS.
THU/THU NGT...SHRTWV OVER FAR NW ONTARIO AT 12Z THU IS PROGGED TO
SLIDE SE INTO WRN QUEBEC THU NGT AND DRAG A COLD FNT ACRS UPR MI
SOMETIME THU AFTN/EVNG. ARRIVAL OF THIS BNDRY/BAND OF MODEST DEEP
LYR FORCING AT A TIME WHEN DAYTIME HEATING WL HAVE AN IMPACT FAVORS
SOME SHOWERS/TS...BUT ABSENCE OF MUCH IN THE WAY OF HGT FALLS WELL
TO THE SW OF TRACK OF SHRTWV/SHARPEST FORCING...QUESTIONS ABOUT
DEGREE OF MSTR INFLOW AHEAD OF THE FNT AND TIMING DIFFERENCES AMONG
THE MODELS ON FROPA TIMING WARRANT NO HIER THAN LO CHC POPS ATTM.
THU LOOKS TO BE A WARM DAY WITH H85 TEMPS PUSHING 18-20C AHEAD OF
THE FNT.
EXTENDED...HI PRES TRAILING THE COLD FROPA WL BRING MOCLR WX FOR FRI
AND SAT. FRI WL BE COOLER WITH H85 TEMPS DIPPING TO ARND 14C...BUT
THEN SAT WL TURN WARMER AS THE HI SHIFTS TO THE E AND RETURN SSW
FLOW LIFTS H85 TEMPS UP TO 16C. THE NEXT CHC OF SHOWERS/TS WL ARRIVE
ON SUN AHEAD OF NEXT DISTURBANCE RIDING OVER THE PLAINS RDG.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 119 AM EDT MON AUG 10 2015
SCT SHOWERS INTO CENTRAL UPPER MICHIGAN MAY STILL BRUSH KSAW EARLY
IN THE TAF PERIOD. OTHERWISE...MAINLY DRY CONDITIONS ARE EXPECTED
OVERNIGHT AT KCMX/KIWD.
ONCE THE COLD FRONT MOVES THROUGH THE AREA OVERNIGHT AND BREAKS IN
THE CLOUDS OCCUR...EXPECT SOME SHALLOW FOG TO DEVELOP AT ALL THREE
TERMINALS...ESPECIALLY AT KSAW WHERE RAIN FELL AND THE LIGHTEST
WINDS WILL OCCUR. THE FCST IS NOT AS PESSIMISTIC FOR THE WEST
TERMINALS...AS LOW LEVEL WINDS WILL SLOWLY BE INCREASING THROUGH THE
NIGHT WHICH WILL RESULT IN MORE MIXING INTO THE DRIER AIR ALOFT.
FOR TODAY...EXPECT CONDITIONS IMPROVING TO VFR THROUGH THE MORNING
HOURS AS THE AREA IS IN BETWEEN THE DEPARTING FRONT AND ANOTHER
UPPER LEVEL DISTURBANCE ARRIVING LATE AFTERNOON AND EVENING.
SCT/ISOLD SHRA MAY BE POSSIBLE DURING THE EVENING BUT SHOULD HAVE
LITTLE IMPACT ON CIGS/VSBY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 308 PM EDT SUN AUG 9 2015
A COLD FRONT MOVING ACROSS WEST-CENTRAL LAKE SUPERIOR AT THIS TIME
WILL PUSH EAST ACROSS THE REST OF THE LAKE TONIGHT WILL LEAD TO A
WIND SHIFT FROM SOUTHERLY TO NORTHWESTERLY. WITH GENERALLY A WEAK
PRES GRADIENT...WINDS SHOULD REMAIN UNDER 20KT THRU MON. PATCHY TO
AREAS OF FOG HAS BEEN OBSERVED ON SATELLITE FOR PORTIONS OF THE
LAKE AND EXPECT THAT TO DIMINISH TONIGHT INTO MONDAY AS SLIGHTLY
DRIER AIR ARRIVES BEHIND THE FRONT. MON NIGHT/TUE...THE GRADIENT
TIGHTENS A BIT AHEAD OF APPROACHING SFC HIGH PRES...SO WINDS OVER
THE E HALF OF LAKE SUPERIOR WILL PROBABLY BEGIN TO GUST MORE
FREQUENTLY TO AROUND 20KT. ARRIVAL OF SFC HIGH PRES RIDGE WILL
RESULT IN WINDS UNDER 15KT TUE NIGHT/WED. WINDS WILL THEN INCREASE
SOME OUT OF THE SOUTHWEST INTO THU AHEAD OF THE NEXT APPROACHING
COLD FRONT. THAT FRONT WILL SHIFT WINDS TO THE NORTHWEST FOR
FRIDAY...BUT SHOULD STAY BELOW 20KTS AT HIGH PRESSURE BUILDS BACK
OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1252 PM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1037 AM CDT MON AUG 10 2015
UPDATED THE FORECAST THROUGH AROUND MIDNIGHT...FOCUSING ON PCPN
CHANCES AND CLOUD COVER. LATEST MODEL SOUNDINGS AND HRRR RUNS
SUGGEST THERE WILL BE SCT/BKN CUMULUS ACROSS MUCH OF THE FORECAST
AREA BY EARLY THIS AFTERNOON...SO EXPANDED CLOUD COVER. THE LATEST
NAM12/SREF/GFS/HRRR INDICATED THE NORTHERN AND SE FORECAST AREA
COULD GET ISOLATED/SCATTERED SHOWERS AND STORMS THIS AFTERNOON AND
EARLY EVENING...SO INCREASED AND EXPANDED COVERAGE OF PCPN
CHANCES.
THERE MAY BE A THREAT FOR ISOLATED STRONG STORMS IN THE COOK
COUNTY AREA OF THE ARROWHEAD THIS AFTERNOON AND EARLY EVENING. THE
NAM12 AND GFS SOUNDINGS FOR THE HIGHER TERRAIN OF THE ARROWHEAD
INDICATE MUCAPE COULD BUILD TO AROUND 1000 J/KG BY THE MIDDLE OF
THE AFTERNOON...AND THERE WOULD BE ABOUT 30 TO 35 KNOTS OF DEEP
LAYER WIND SHEAR. ALSO...FREEZING LEVELS WILL BE RELATIVELY LOW IN
THE HIGHER TERRAIN...ABOUT 9000 FT. THEREFORE...WOULD NOT BE
SURPRISED BY ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL AND
GUSTY WINDS.
UPDATE ISSUED AT 612 AM CDT MON AUG 10 2015
PATCHY FOG WAS DOTTING THE LANDSCAPE...BUT SHOULD BURN OFF
QUICKLY. STILL ANTICIPATING SHOWERS AND STORMS WITH THE SHORTWAVE
TROF SET TO CLIP THE ARROWHEAD TODAY. LOWERED THE POPS IN NW WI A
BIT AS THE TROF STAYS A BIT FURTHER EAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
A SFC LOW CENTER WAS MOVING THROUGH EASTERN LAKE SUPERIOR AT 07Z
WITH ITS ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH NW WI. AREAS OF
FOG HAD FORMED ONCE AGAIN ACROSS MUCH OF THE REGION. EXPECT THE FOG
TO LINGER UNTIL 14Z. AS THE FRONT EXITS NW WI...HIGH PRESSURE BUILDS
ACROSS THE AREA. HOWEVER...AN UPPER LEVEL SHORTWAVE TROF WILL REACH
THE INTERNATIONAL BORDER BY 18Z AND PROCEED ACROSS THE ARROWHEAD AND
OVER LAKE SUPERIOR. SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN
TO AFFECT THE ARROWHEAD WWD TO NEAR CDD AT 15Z. STORMS WILL
PERCOLATE OVER THE ARROWHEAD THROUGH THE AFTERNOON WITH SOME STORM
DEVELOPMENT IN NW WI IN THE AFTERNOON.
THE SHORTWAVE TROF REACHES NORTHERN LOWER MICHIGAN BY 06Z TUESDAY.
ONE MORE IMPULSE WILL CLIP THE ARROWHEAD BEHIND THE TROF AND RESULT
IN SOME ISOLD SHOWERS FROM CKC TO GRAND PORTAGE. THIS ACTIVITY WILL
DIMINISH BY 03Z AS FORCING MOVES EAST AND SFC RIDGING COVERS THE
AREA. THE SFC RIDGING PERSISTS THROUGH TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
WARMER MID-WEEK WITH HIGHS IN THE LOW TO MID 80S ACROSS THE
REGION...THEN NOT AS HOT BUT STILL ABOVE NORMAL THROUGH SATURDAY
WITH HIGHS IN THE UPPER 70S TO LOW 80S. TWO MAIN PERIODS OF POSSIBLE
PRECIPITATION...ONE ON WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT
SWEEPS THROUGH FROM NORTHWEST TO SOUTHEAST...THEN AGAIN SATURDAY
NIGHT INTO SUNDAY AS ANOTHER COLD FRONT MOVES THROUGH. SOME
UNCERTAINTY EXISTS WITH THE TIMING OF THE LATE WEEKEND SYSTEM...BUT
IN GENERAL HAVE AN AVERAGE LEVEL OF CONFIDENCE FOR THE FORECAST.
ON THE SYNOPTIC SCALE A UPPER LEVEL RIDGE CENTERED OVER THE HIGH
PLAINS WILL GRADUALLY DRIFT WESTWARD TOWARDS THE FOUR CORNERS
THROUGH THE REST OF THE WORK WEEK...LEADING TO NORTHWEST FLOW ALOFT
LOCALLY. AHEAD OF A COLD FRONT/MID LEVEL DISTURBANCE SOUTHWESTERLY
WINDS COULD BECOME BREEZY WITH STRONG WARM AIR ADVECTION LEADING TO
PROBABLY THE WARMEST DAY OF THE FORECAST PERIOD. THERE IS A WEAK MID-
LEVEL IMPULSES IN THE NORTHWESTERLY FLOW WITH AN ASSOCIATED SFC LOW
THAT MOVES ACROSS NORTHWEST MINNESOTA INTO NORTHERN WISCONSIN LATE
WEDNESDAY INTO THURSDAY. THIS WILL BE SUPPORTED BY A 60-80 KT UPPER
LEVEL JET STREAK OVER THE UPPER MISSISSIPPI VALLEY...POSSIBLY
PEAKING UP TO 100 KTS IN STRENGTH OVER CENTRAL MINNESOTA. MODEL
SOUNDINGS DEPICT MODEST MID-LEVEL LAPSE RATES TO SUPPORT
THUNDERSTORMS...AND THE STRONG WINDS ALOFT WILL RESULT IN 35-45 KTS
DEEP LAYER SHEAR SUPPORTIVE OF POSSIBLY A FEW STRONG STORMS
OVERNIGHT INTO THURSDAY. COVERAGE OF STORMS MAY BE LIMITED GIVEN
ELEVATED NATURE AND DEPENDENCE ON UPSTREAM CONVECTION
EVOLUTION...BUT IN GENERAL THIS PERIOD LOOKS GOOD FOR
ISOLATED/SCATTERED STORMS.
FRIDAY/SATURDAY A HIGH PRESSURE OVER SOUTHERN SASKATCHEWAN/MANITOBA
DRIFTS INTO THE NORTHERN PLAINS THEN EAST ACROSS THE UPPER GREAT
LAKES RESULTING IN SUNNY SKIES AND SEASONABLE TO JUST ABOVE NORMAL
TEMPERATURES...UPPER 70S TO MID 80S. LATE SATURDAY INTO SUNDAY AN
UPPER LOW ENTERING BRITISH COLUMBIA WILL ABSORB THE ENERGY FROM AN
UPPER LOW OFF THE COAST OF THE PACIFIC NORTHWEST...DEEPENING INTO AN
UPPER LOW/TROUGH AS IT CROSSES THE CANADIAN PRAIRIE. A SECONDARY SFC
LOW/LEE TROUGH WILL DEVELOP OVER THE NORTHERN PLAINS ON SATURDAY
ALONG A COLD FRONT EXTENDING FROM NEAR THE MAIN SFC LOW IN SOUTHERN
CANADA INTO THE CENTRAL PLAINS. GUIDANCE IS IN FAIRLY REMARKABLE
AGREEMENT FOR THIS TIME RANGE...WITH ECMWF/GFS/GEM DEPICTING A
STRONG COLD FRONT IN THE EASTERN DAKOTAS/FAR WESTERN MINNESOTA
AROUND 00Z SUNDAY /SAT NIGHT/ PROGRESSING EASTWARD...THOUGH FROM
THERE MODEL SOLUTIONS DIVERGE. PRECIP CHANCES LOOK FAIRLY HIGH
REGARDLESS OF SPECIFICS. MOISTURE CONTENT WITH THIS SYSTEM MAY BE ON
THE HIGH SIDE GIVEN THE PACIFIC INFLUENCES. COOLER TEMPERATURES
EXPECTED IN WAKE OF THIS FRONT WITH HIGHS NEAR OR SLIGHTLY BELOW
SEASONABLE...IN THE LOW TO MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1238 PM CDT MON AUG 10 2015
VFR CONDITIONS EXPECTED THROUGH THE NEXT 24 HOURS WITH A SCT-BKN
CLOUD DECK AROUND 040-050 THIS AFTERNOON AND VCSH AROUND INL AND
HIB. CLOUDS SCOUR OUT THIS EVENING AND TONIGHT. MAY SEE SOME
PATCHY FOG LATE TONIGHT AND TUE MORNING. NW WINDS WILL GUST 10 TO
15 KTS TODAY AND BECOME LIGHT FROM THE NW TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 77 57 75 59 / 20 10 0 10
INL 75 52 77 56 / 20 10 0 10
BRD 79 55 80 56 / 0 0 0 0
HYR 77 55 76 53 / 20 20 0 10
ASX 76 57 73 54 / 20 20 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...TENTINGER
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1037 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1037 AM CDT MON AUG 10 2015
UPDATED THE FORECAST THROUGH AROUND MIDNIGHT...FOCUSING ON PCPN
CHANCES AND CLOUD COVER. LATEST MODEL SOUNDINGS AND HRRR RUNS
SUGGEST THERE WILL BE SCT/BKN CUMULUS ACROSS MUCH OF THE FORECAST
AREA BY EARLY THIS AFTERNOON...SO EXPANDED CLOUD COVER. THE LATEST
NAM12/SREF/GFS/HRRR INDICATED THE NORTHERN AND SE FORECAST AREA
COULD GET ISOLATED/SCATTERED SHOWERS AND STORMS THIS AFTERNOON AND
EARLY EVENING...SO INCREASED AND EXPANDED COVERAGE OF PCPN
CHANCES.
THERE MAY BE A THREAT FOR ISOLATED STRONG STORMS IN THE COOK
COUNTY AREA OF THE ARROWHEAD THIS AFTERNOON AND EARLY EVENING. THE
NAM12 AND GFS SOUNDINGS FOR THE HIGHER TERRAIN OF THE ARROWHEAD
INDICATE MUCAPE COULD BUILD TO AROUND 1000 J/KG BY THE MIDDLE OF
THE AFTERNOON...AND THERE WOULD BE ABOUT 30 TO 35 KNOTS OF DEEP
LAYER WIND SHEAR. ALSO...FREEZING LEVELS WILL BE RELATIVELY LOW IN
THE HIGHER TERRAIN...ABOUT 9000 FT. THEREFORE...WOULD NOT BE
SURPRISED BY ISOLATED STORMS CAPABLE OF PRODUCING SMALL HAIL AND
GUSTY WINDS.
UPDATE ISSUED AT 612 AM CDT MON AUG 10 2015
PATCHY FOG WAS DOTTING THE LANDSCAPE...BUT SHOULD BURN OFF
QUICKLY. STILL ANTICIPATING SHOWERS AND STORMS WITH THE SHORTWAVE
TROF SET TO CLIP THE ARROWHEAD TODAY. LOWERED THE POPS IN NW WI A
BIT AS THE TROF STAYS A BIT FURTHER EAST.
&&
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
A SFC LOW CENTER WAS MOVING THROUGH EASTERN LAKE SUPERIOR AT 07Z
WITH ITS ASSOCIATED FRONTAL BOUNDARY MOVING THROUGH NW WI. AREAS OF
FOG HAD FORMED ONCE AGAIN ACROSS MUCH OF THE REGION. EXPECT THE FOG
TO LINGER UNTIL 14Z. AS THE FRONT EXITS NW WI...HIGH PRESSURE BUILDS
ACROSS THE AREA. HOWEVER...AN UPPER LEVEL SHORTWAVE TROF WILL REACH
THE INTERNATIONAL BORDER BY 18Z AND PROCEED ACROSS THE ARROWHEAD AND
OVER LAKE SUPERIOR. SCATTERED SHOWERS AND THUNDERSTORMS WILL BEGIN
TO AFFECT THE ARROWHEAD WWD TO NEAR CDD AT 15Z. STORMS WILL
PERCOLATE OVER THE ARROWHEAD THROUGH THE AFTERNOON WITH SOME STORM
DEVELOPMENT IN NW WI IN THE AFTERNOON.
THE SHORTWAVE TROF REACHES NORTHERN LOWER MICHIGAN BY 06Z TUESDAY.
ONE MORE IMPULSE WILL CLIP THE ARROWHEAD BEHIND THE TROF AND RESULT
IN SOME ISOLD SHOWERS FROM CKC TO GRAND PORTAGE. THIS ACTIVITY WILL
DIMINISH BY 03Z AS FORCING MOVES EAST AND SFC RIDGING COVERS THE
AREA. THE SFC RIDGING PERSISTS THROUGH TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 309 AM CDT MON AUG 10 2015
WARMER MID-WEEK WITH HIGHS IN THE LOW TO MID 80S ACROSS THE
REGION...THEN NOT AS HOT BUT STILL ABOVE NORMAL THROUGH SATURDAY
WITH HIGHS IN THE UPPER 70S TO LOW 80S. TWO MAIN PERIODS OF POSSIBLE
PRECIPITATION...ONE ON WEDNESDAY NIGHT INTO THURSDAY AS A COLD FRONT
SWEEPS THROUGH FROM NORTHWEST TO SOUTHEAST...THEN AGAIN SATURDAY
NIGHT INTO SUNDAY AS ANOTHER COLD FRONT MOVES THROUGH. SOME
UNCERTAINTY EXISTS WITH THE TIMING OF THE LATE WEEKEND SYSTEM...BUT
IN GENERAL HAVE AN AVERAGE LEVEL OF CONFIDENCE FOR THE FORECAST.
ON THE SYNOPTIC SCALE A UPPER LEVEL RIDGE CENTERED OVER THE HIGH
PLAINS WILL GRADUALLY DRIFT WESTWARD TOWARDS THE FOUR CORNERS
THROUGH THE REST OF THE WORK WEEK...LEADING TO NORTHWEST FLOW ALOFT
LOCALLY. AHEAD OF A COLD FRONT/MID LEVEL DISTURBANCE SOUTHWESTERLY
WINDS COULD BECOME BREEZY WITH STRONG WARM AIR ADVECTION LEADING TO
PROBABLY THE WARMEST DAY OF THE FORECAST PERIOD. THERE IS A WEAK MID-
LEVEL IMPULSES IN THE NORTHWESTERLY FLOW WITH AN ASSOCIATED SFC LOW
THAT MOVES ACROSS NORTHWEST MINNESOTA INTO NORTHERN WISCONSIN LATE
WEDNESDAY INTO THURSDAY. THIS WILL BE SUPPORTED BY A 60-80 KT UPPER
LEVEL JET STREAK OVER THE UPPER MISSISSIPPI VALLEY...POSSIBLY
PEAKING UP TO 100 KTS IN STRENGTH OVER CENTRAL MINNESOTA. MODEL
SOUNDINGS DEPICT MODEST MID-LEVEL LAPSE RATES TO SUPPORT
THUNDERSTORMS...AND THE STRONG WINDS ALOFT WILL RESULT IN 35-45 KTS
DEEP LAYER SHEAR SUPPORTIVE OF POSSIBLY A FEW STRONG STORMS
OVERNIGHT INTO THURSDAY. COVERAGE OF STORMS MAY BE LIMITED GIVEN
ELEVATED NATURE AND DEPENDENCE ON UPSTREAM CONVECTION
EVOLUTION...BUT IN GENERAL THIS PERIOD LOOKS GOOD FOR
ISOLATED/SCATTERED STORMS.
FRIDAY/SATURDAY A HIGH PRESSURE OVER SOUTHERN SASKATCHEWAN/MANITOBA
DRIFTS INTO THE NORTHERN PLAINS THEN EAST ACROSS THE UPPER GREAT
LAKES RESULTING IN SUNNY SKIES AND SEASONABLE TO JUST ABOVE NORMAL
TEMPERATURES...UPPER 70S TO MID 80S. LATE SATURDAY INTO SUNDAY AN
UPPER LOW ENTERING BRITISH COLUMBIA WILL ABSORB THE ENERGY FROM AN
UPPER LOW OFF THE COAST OF THE PACIFIC NORTHWEST...DEEPENING INTO AN
UPPER LOW/TROUGH AS IT CROSSES THE CANADIAN PRAIRIE. A SECONDARY SFC
LOW/LEE TROUGH WILL DEVELOP OVER THE NORTHERN PLAINS ON SATURDAY
ALONG A COLD FRONT EXTENDING FROM NEAR THE MAIN SFC LOW IN SOUTHERN
CANADA INTO THE CENTRAL PLAINS. GUIDANCE IS IN FAIRLY REMARKABLE
AGREEMENT FOR THIS TIME RANGE...WITH ECMWF/GFS/GEM DEPICTING A
STRONG COLD FRONT IN THE EASTERN DAKOTAS/FAR WESTERN MINNESOTA
AROUND 00Z SUNDAY /SAT NIGHT/ PROGRESSING EASTWARD...THOUGH FROM
THERE MODEL SOLUTIONS DIVERGE. PRECIP CHANCES LOOK FAIRLY HIGH
REGARDLESS OF SPECIFICS. MOISTURE CONTENT WITH THIS SYSTEM MAY BE ON
THE HIGH SIDE GIVEN THE PACIFIC INFLUENCES. COOLER TEMPERATURES
EXPECTED IN WAKE OF THIS FRONT WITH HIGHS NEAR OR SLIGHTLY BELOW
SEASONABLE...IN THE LOW TO MID 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 647 AM CDT MON AUG 10 2015
WITH MINOR EXCEPTIONS...VFR CONDITIONS ARE EXPECTED THROUGH THE
TAF PERIOD THROUGHOUT THE REGION. PATCHY FOG RESULTING IN IFR
CONDITIONS AT HYR THIS MORNING BUT WILL LIFT AND CLEAR OUT OVER
THE NEXT HOUR. OTHERWISE EXPECTING SCATTERED/BROKEN 4-5KFT CLOUD
DECK TO DEVELOP THIS AFTERNOON WITH AN ISOLATED SHOWER POSSIBLE AT
HIB AND INL. OVERNIGHT TONIGHT SKIES GRADUALLY CLEAR OUT WITH
PATCHY FOG AGAIN POSSIBLE...FELT MOST CONFIDENT FOR HIB SO
INCLUDED A MENTION OF MVFR VISIBILITY LATE TONIGHT. OTHER SITES
MAY SEE FOG BUT CHANCES SEEM TOO LOW TO INCLUDE IN THIS TAF
ISSUANCE GIVEN THE COVERAGE OF FOG LAST NIGHT WAS A BIT LESS THAN
ORIGINALLY ANTICIPATED. WINDS LIGHT OUT OF THE NORTH-
NORTHWEST...WITH A FEW GUSTS TO AROUND 17 KTS POSSIBLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 77 57 75 59 / 20 10 0 10
INL 74 52 77 56 / 20 10 0 10
BRD 79 55 80 56 / 0 0 0 0
HYR 77 55 76 53 / 20 20 0 10
ASX 76 57 73 54 / 20 20 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...GSF
LONG TERM...JJM
AVIATION...JJM
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
940 AM CDT AUG 10 2015
.UPDATE...LATEST SATELLITE IMAGERY WAS SHOWING A WEAKENING MCS
ASSOCIATED WITH A SHORT WAVE OVER THE MIDSOUTH. IT HAD SENT A DRY
OUTFLOW BOUNDARY INTO OUR NORTHERN COUNTIES AS OF MID MORNING. THE
BOUNDARY WILL BE MOVING INTO A CAPPED REGION WITH THE STRONG
SUBTROPICAL RIDGE CENTERED OVER THE WESTERN ARKLATEX. IT SHOULD
LIMIT THE STRONG THUNDERSTORM POTENTIAL FOR THIS AFTERNOON. WILL
MONITOR THE BOUNDARY AS IT MOVES THROUGH THE REGION FOR ANY GOOD CU
FIELD CONVERGENCE ON SATELLITE. IT WILL BE ANOTHER HOT DAY. THE
BLOWOFF FROM THE MCS MAY HAMPER TEMPS SLIGHTLY IN THE
NORTHEAST...BUT WILL HOLD ONTO THE UPPER 90S IN THAT AREA. TEMPS
HAVE ALREADY HIT 90 AT JAN AS OF 920 AM. CURRENT POPS LOOK TO BE ON
TRACK. THE HRRR HIRES DEVELOPS SOME DECENT CONVECTIVE COVERAGE FOR
THIS AFTERNOON EAST OF MS RIVER WITH THE OUTFLOW BOUNDARY MOVING
THROUGH. SO WITH THAT IN MIND WILL MAKE NO CHANGES TO CURRENT
FORECAST TEMPS AND POPS./17/
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL THROUGH THE DAY AT MOST
TERMINALS. ISOLATED TO SCATTERED STORMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON, MOST LIKELY TO BE AROUND GTR, JAN/HKS, MEI, AND HBG/PIB
THROUGH EARLY EVENING. BRIEF CIG/VISBY REDUCTIONS DUE TO +RA AND
GUSTY WINDS ARE POSSIBLE WITH THE STORMS. LATER TONIGHT, A SHORT
PERIOD OF PATCHY FOG IS POSSIBLE AROUND DAYBREAK, MAINLY AT SITES
ALONG AND SOUTH OF I-20. /DL/
&&
./PREVIOUS DISCUSSION...529 AM CDT MON AUG 10 2015
.DISCUSSION...
TODAY THROUGH TUESDAY NIGHT...
A STRONG SUBTROPICAL RIDGE CENTERED OVER THE ARKLATEX REGION...
SUPPORTS ANOTHER DAY OF EXCESSIVE HEAT ACROSS THE ARKLAMISS WITH
H850 TEMPERATURES EXPECTED TO PEAK AROUND 25 DEG C...BUT MESOSCALE
INFLUENCES RAISE UNCERTAINTY REGARDING THE EXACT DURATION/INTENSITY
OF TODAY`S HEAT EVENT. A SIGNIFICANT SHORTWAVE TROUGH MOVING THROUGH
THE MID MS VALLEY REGION HAS INITIATED A MESOSCALE CONVECTIVE
SYSTEM THAT IS MOVING SOUTHEAST INTO NE AR/WRN TN. EXTRAPOLATION OF
THE OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS BRINGS IT TO THE HWY
82 CORRIDOR LATE THIS MORNING...AND RECENT RUNS OF THE HRRR HAVE A
GOOD HANDLE ON THIS ASSUMING CURRENT TIMING IS MAINTAINED.
PER HRRR GUIDANCE...THE DENSITY OF THE OUTFLOW WILL BE SUFFICIENT
FOR IT TO CONTINUE MOVING SOUTHWARD THROUGH THE ENTIRE AREA BY LATE
AFTN...HOWEVER IT WILL BE MOVING INTO AND AIRMASS THAT IS SOMEWHAT
CAPPED AND THIS COULD LIMIT OVERALL THUNDERSTORM POTENTIAL. STORM
DEVELOPMENT AND INTENSITY WILL BE GOVERNED BY HOW MUCH DESTABILIZATION
CAN TAKE PLACE PRECEDING THE FAST-MOVING BOUNDARY. THE NEW SPC SSEO
IS HINTING AT A GREATER THREAT FOR STORMS OVER EASTERN/SOUTHERN MS
LATE THIS AFTN/EVNG...BUT THE TIMING COULD BE TOO SLOW. WILL BE
MONITORING TRENDS TO POTENTIALLY ADD A LIMITED THREAT FOR SEVERE
STORMS FOR THIS AFTN/EVNG...ESPECIALLY IF THE BOUNDARY SLOWS DOWN
SOME.
ASIDE FROM THE STORM POTENTIAL TODAY...THE BOUNDARY WILL ACT TO
DISRUPT HEATING AND COULD HELP TO MITIGATE OVERALL HEAT STRESS IF THE
AIRMASS IS UNABLE TO RECOVER AND HEAT BACK UP IN THE WAKE OF THE
BOUNDARY. CURRENT INDICATIONS IN THE HRRR ARE THAT RE- HEATING SO TO
SPEAK WILL TAKE PLACE OVER NORTH CENTRAL/NE MS...BUT LOCATIONS
FARTHER SOUTH/WEST MAY SEE A PRE-MATURE ENDING TO THE DIURNAL
TEMPERATURE TREND THAT COULD RESULT IN HIGH TEMPERATURES/HEAT INDICES
THAT ARE A LITTLE LESS THAN PREVIOUSLY EXPECTED.
THE FORECAST FOR TUESDAY LARGELY HINGES ON TODAY AND THIS EVENING`S
CONVECTIVE EVOLUTION. IT SHOULD BE THE LAST DAY OF DANGEROUS HEAT IN
THIS EPISODE WITH GREATEST CONFIDENCE FOR HIGHER HEAT INDICES MAINLY
ALONG/S OF THE I-20 CORRIDOR. CONFIDENCE IS HIGH ENOUGH TO WARRANT
ISSUANCE OF A HEAT ADVISORY...BUT THERE IS SOME MARGINAL POTENTIAL
THAT AN EXCESSIVE HEAT WARNING COULD BECOME NECESSARY OVER PORTIONS
OF NE LA/SW MS. CONCERNING STORM POTENTIAL...FOR NOW HAVE STUCK WITH
THE IDEA THAT STORMS TODAY WILL LIMIT TUESDAY`S CONVECTIVE
DEVELOPMENT TO MAINLY ERN/SRN MS AHEAD OF AN APPROACHING FRONT AND
THE LEADING EDGE OF MUCH DRIER AIR. IT IS POSSIBLE THAT A MARGINAL
THREAT FOR SEVERE STORMS WILL EXIST DEPENDING ON THE AMOUNT OF
DESTABILIZATION. /EC/
WEDNESDAY THROUGH NEXT SUNDAY...
UNFORTUNATELY THROUGHOUT THE CURRENT LONG TERM PORTION OF THE
FORECAST...IT APPEARS THERE`S VERY LITTLE HOPE IN THE WAY OF GETTING
SOME MUCH NEEDED RAINFALL OVER THE REGION. HOWEVER...THE "SILVER
LINING" DURING THE PERIOD WILL BE FOUND IN GETTING SOME RELIEF FROM
THE OPPRESSIVE HEAT THAT`S PLAGUED THE FORECAST AREA IN RECENT
DAYS/WEEKS.
THE FORECAST AREA WILL BECOME FIXED BETWEEN AN UPPER TROUGH OVER THE
EAST COAST OF THE UNITED STATES AND THE STUBBORN UPPER RIDGE
CENTERED NEAR THE FOUR CORNERS REGION. NORTHERLY FLOW ALOFT AND AT
THE SURFACE THROUGH MUCH OF THE WEEK WILL ADVECT DRIER AIR INTO THE
REGION. WHILE HIGHS TOP OUT IN THE LOW TO MIDDLE 90S...THE
NOTICEABLY DRIER AIR WILL HELP TO MAKE FOR MORE TOLERABLE CONDITIONS
EACH AFTERNOON...AS WELL AS OVERNIGHT AS LOWS FALL INTO THE 60S AND
70S. AS EXPECTED THROUGH...DEW POINTS WILL MODERATE UP SLIGHTLY
OVER THE WEEKEND...AND THE CHANCES OF AT LEAST SOME ISOLATED
CONVECTION RETURNING TO THE FORECAST SATURDAY AND SUNDAY. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 102 77 99 75 / 30 31 32 21
MERIDIAN 100 73 94 74 / 23 42 43 29
VICKSBURG 103 77 99 73 / 22 18 23 15
HATTIESBURG 100 76 98 76 / 20 17 49 42
NATCHEZ 101 78 98 75 / 27 16 33 20
GREENVILLE 101 77 96 73 / 12 18 7 7
GREENWOOD 100 75 95 72 / 24 28 15 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MSZ018-
019-025>066-072>074.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
MSZ040>043-047>066-072>074.
LA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023>026.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
LAZ007>009-015-016-023>026.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR ARZ074-
075.
&&
$$
EC/19/
AREA FORECAST DISCUSSION
NWS JACKSON MS
529 AM CDT MON AUG 10 2015
.DISCUSSION...
TODAY THROUGH TUESDAY NIGHT...
A STRONG SUBTROPICAL RIDGE CENTERED OVER THE ARKLATEX REGION...
SUPPORTS ANOTHER DAY OF EXCESSIVE HEAT ACROSS THE ARKLAMISS WITH
H850 TEMPERATURES EXPECTED TO PEAK AROUND 25 DEG C...BUT MESOSCALE
INFLUENCES RAISE UNCERTAINTY REGARDING THE EXACT DURATION/INTENSITY
OF TODAY`S HEAT EVENT. A SIGNIFICANT SHORTWAVE TROUGH MOVING THROUGH
THE MID MS VALLEY REGION HAS INITIATED A MESOSCALE CONVECTIVE
SYSTEM THAT IS MOVING SOUTHEAST INTO NE AR/WRN TN. EXTRAPOLATION OF
THE OUTFLOW BOUNDARY ASSOCIATED WITH THIS MCS BRINGS IT TO THE HWY
82 CORRIDOR LATE THIS MORNING...AND RECENT RUNS OF THE HRRR HAVE A
GOOD HANDLE ON THIS ASSUMING CURRENT TIMING IS MAINTAINED.
PER HRRR GUIDANCE...THE DENSITY OF THE OUTFLOW WILL BE SUFFICIENT
FOR IT TO CONTINUE MOVING SOUTHWARD THROUGH THE ENTIRE AREA BY LATE
AFTN...HOWEVER IT WILL BE MOVING INTO AND AIRMASS THAT IS SOMEWHAT
CAPPED AND THIS COULD LIMIT OVERALL THUNDERSTORM POTENTIAL. STORM
DEVELOPMENT AND INTENSITY WILL BE GOVERNED BY HOW MUCH DESTABILIZATION
CAN TAKE PLACE PRECEDING THE FAST-MOVING BOUNDARY. THE NEW SPC SSEO
IS HINTING AT A GREATER THREAT FOR STORMS OVER EASTERN/SOUTHERN MS
LATE THIS AFTN/EVNG...BUT THE TIMING COULD BE TOO SLOW. WILL BE
MONITORING TRENDS TO POTENTIALLY ADD A LIMITED THREAT FOR SEVERE
STORMS FOR THIS AFTN/EVNG...ESPECIALLY IF THE BOUNDARY SLOWS DOWN
SOME.
ASIDE FROM THE STORM POTENTIAL TODAY...THE BOUNDARY WILL ACT TO
DISRUPT HEATING AND COULD HELP TO MITIGATE OVERALL HEAT STRESS IF THE
AIRMASS IS UNABLE TO RECOVER AND HEAT BACK UP IN THE WAKE OF THE
BOUNDARY. CURRENT INDICATIONS IN THE HRRR ARE THAT RE- HEATING SO TO
SPEAK WILL TAKE PLACE OVER NORTH CENTRAL/NE MS...BUT LOCATIONS
FARTHER SOUTH/WEST MAY SEE A PRE-MATURE ENDING TO THE DIURNAL
TEMPERATURE TREND THAT COULD RESULT IN HIGH TEMPERATURES/HEAT INDICES
THAT ARE A LITTLE LESS THAN PREVIOUSLY EXPECTED.
THE FORECAST FOR TUESDAY LARGELY HINGES ON TODAY AND THIS EVENING`S
CONVECTIVE EVOLUTION. IT SHOULD BE THE LAST DAY OF DANGEROUS HEAT IN
THIS EPISODE WITH GREATEST CONFIDENCE FOR HIGHER HEAT INDICES MAINLY
ALONG/S OF THE I-20 CORRIDOR. CONFIDENCE IS HIGH ENOUGH TO WARRANT
ISSUANCE OF A HEAT ADVISORY...BUT THERE IS SOME MARGINAL POTENTIAL
THAT AN EXCESSIVE HEAT WARNING COULD BECOME NECESSARY OVER PORTIONS
OF NE LA/SW MS. CONCERNING STORM POTENTIAL...FOR NOW HAVE STUCK WITH
THE IDEA THAT STORMS TODAY WILL LIMIT TUESDAY`S CONVECTIVE
DEVELOPMENT TO MAINLY ERN/SRN MS AHEAD OF AN APPROACHING FRONT AND
THE LEADING EDGE OF MUCH DRIER AIR. IT IS POSSIBLE THAT A MARGINAL
THREAT FOR SEVERE STORMS WILL EXIST DEPENDING ON THE AMOUNT OF
DESTABILIZATION. /EC/
WEDNESDAY THROUGH NEXT SUNDAY...
UNFORTUNATELY THROUGHOUT THE CURRENT LONG TERM PORTION OF THE
FORECAST...IT APPEARS THERE`S VERY LITTLE HOPE IN THE WAY OF GETTING
SOME MUCH NEEDED RAINFALL OVER THE REGION. HOWEVER...THE "SILVER
LINING" DURING THE PERIOD WILL BE FOUND IN GETTING SOME RELIEF FROM
THE OPPRESSIVE HEAT THAT`S PLAGUED THE FORECAST AREA IN RECENT
DAYS/WEEKS.
THE FORECAST AREA WILL BECOME FIXED BETWEEN AN UPPER TROUGH OVER THE
EAST COAST OF THE UNITED STATES AND THE STUBBORN UPPER RIDGE
CENTERED NEAR THE FOUR CORNERS REGION. NORTHERLY FLOW ALOFT AND AT
THE SURFACE THROUGH MUCH OF THE WEEK WILL ADVECT DRIER AIR INTO THE
REGION. WHILE HIGHS TOP OUT IN THE LOW TO MIDDLE 90S...THE
NOTICEABLY DRIER AIR WILL HELP TO MAKE FOR MORE TOLERABLE CONDITIONS
EACH AFTERNOON...AS WELL AS OVERNIGHT AS LOWS FALL INTO THE 60S AND
70S. AS EXPECTED THROUGH...DEW POINTS WILL MODERATE UP SLIGHTLY
OVER THE WEEKEND...AND THE CHANCES OF AT LEAST SOME ISOLATED
CONVECTION RETURNING TO THE FORECAST SATURDAY AND SUNDAY. /19/
&&
.AVIATION...VFR CONDITIONS WILL BE THE GENERAL RULE TODAY THROUGH
TONIGHT. THE EXCEPTIONS WILL BE A MIX OF HAZE/MIST EARLY THIS MORNING
THAT MAY RESULT IN OCCASIONAL MVFR VSBYS...AND ANY TSRA ACTIVITY THAT
DEVELOPS IN ASSOCIATION WITH AN APPROACHING OUTFLOW
BOUNDARY...ESPECIALLY IN THE GTR AREA. CURRENT EXTRAPOLATION BRINGS
THE BOUNDARY TO VICINITY OF GTR BY AROUND 15Z...BUT THINKING IT WILL
SLOW DOWN SOME AND DELAY TIMING TO MORE OF THE AFTN/EVNG. /EC
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 102 77 99 75 / 30 31 32 21
MERIDIAN 100 73 94 74 / 23 42 43 29
VICKSBURG 103 77 99 73 / 22 18 23 15
HATTIESBURG 100 76 98 76 / 20 17 49 42
NATCHEZ 101 78 98 75 / 27 16 33 20
GREENVILLE 101 77 96 73 / 12 18 7 7
GREENWOOD 100 75 95 72 / 24 28 15 8
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR MSZ018-
019-025>066-072>074.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
MSZ040>043-047>066-072>074.
LA...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
LAZ007>009-015-016-023>026.
HEAT ADVISORY FROM 7 PM THIS EVENING TO 7 PM CDT TUESDAY FOR
LAZ007>009-015-016-023>026.
AR...EXCESSIVE HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR ARZ074-
075.
&&
$$
EC/19/
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
113 PM CDT MON AUG 10 2015
.UPDATE:
ISSUED AT 1255 PM CDT MON AUG 10 2015
NO MAJOR CHANGES MADE. UPDATE WAS MAINLY FOR FINE TUNING POPS AND
SKY COVER FOR THE AFTN. BAND OF SHRAS AND ISLD TSTMS DVLPD LATE
THIS MRNG ALONG THE FRONT. THIS ACTIVITY WILL CONTINUE TO
PERCOLATE THRU THE AFTN AS IT SLOWLY DRIFTS SE. NE MO AND W CNTRL
IL MAY GET CLIPPED LATE THIS AFTN WITH THE TAIL END OF PRECIP
ASSOC WITH A WEAK SHORT WAVE TO OUR NE. NUDGED HIGH TEMPS UP A
A COUPLE DEGREES ACROSS NTHRN ZONES WHERE THERE ARE LESS CLOUDS
AND DOWN A COUPLE DEGREES ACROSS STHRN ZONES WHERE CONVECTIVE
DEBRIS CLOUDS ARE LINGERING.
MILLER
&&
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESDAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1255 PM CDT MON AUG 10 2015
PATCHES OF MVFR STRATUS CONTINUE TO DOT THE REGION EARLY THIS
AFTN. CLOUD HEIGHTS SHOULD CLIMB THRU THE AFTN WITH MVFR CIGS
BCMNG AROUND 21Z. A BAND OF SHRAS AND ISLD TSTMS DVLPD LATE THIS
AFTN ALONG A COLD FRONT. THIS ACTIVITY WILL CONTINUE TO PERCOLATE
THRU THE AFTN WHILE SLOWLY DRIFTING SE. VSBYS MAY BRIEFLY DIP TO
IFR UNDER THE HEAVIEST CORES. ANOTHER AREA OF PRECIP ASSOC WITH AN
UPPER LVL DISTURBANCE NEAR THE STHRN END OF LK MI MAY CLIP KUIN
LATE THIS AFTN BUT CHANCES AREA MINIMAL ATTM. PRECIP SHOULD DSSPT
AND SKIES SLOWLY CLEAR AFTER SUNSET.
SPECIFICS FOR KSTL:
BROKEN LINE OF SHRAS AND ISLD TSTMS HAS DVLPD JUST NORTH OF THE MO
RVR FROM NEAR KC TO STL. VSBYS MAY DROP TO IFR UNDER THE STRONGEST
CORES BUT WILL BE BRIEF. THIS ACTIVITY WILL DRIFT SE THRU THE
AFTN. CONVECTIVE ELEMENTS WILL BE TRANSIENT THE AFTN AND WILL
UNDOUBTABLY HAVE TO UPDATE THE TAF AS THE LINE APPROACHES THE
TERMINAL. SPOTTY MVFR CIGS WILL CONTINUE TO RAISE THRU THE AFN
BECMNG VFR IN A FEW HRS. PRECIP AND CLOUDS WILL SLOWLY DIMINISH
AFTER SUNSET WITH VFR CONDITIONS EXPECTED FOR THE REST OF THE
FCST PRD.
MILLER
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 30 20 5 0
QUINCY 85 64 84 62 / 20 20 5 0
COLUMBIA 87 67 85 63 / 30 10 5 0
JEFFERSON CITY 87 68 86 63 / 30 10 5 0
SALEM 84 70 84 63 / 30 20 10 0
FARMINGTON 84 69 84 61 / 30 20 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
615 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 611 AM CDT MON AUG 10 2015
MAIN AREA OF CONVECTION REMAINS SOUTH OF TERMINALS FROM NEAR LAKE
OF THE OZARKS TO BOOTHEEL OF MISSOURI. COLD FRONT JUST NOW
CROSSING MISSOURI/IOWA STATE LINE AND WILL CONTINUE TO MOVE SOUTH
ACROSS THE AREA THIS MORNING. COULD SEE SOME SHOWERS AND STORMS
DEVELOP ALONG THIS BOUNDARY TODAY...BUT COVERAGE IS EXPECTED TO BE
ISOLATED TO WIDELY SCATTERED AND THEREFORE IS LEFT OUT OF TERMINAL
FORECAST AT THIS TIME. LIGHT SOUTH WIND WILL BECOME NORTHERLY
BEHIND THE FRONT. SOME IFR FOG AND STRATUS EARLY THIS MORNING
SHOULD IMPROVE THROUGH THE MORNING WITH MOSTLY CLEAR CONDITIONS
EXPECTED THIS EVENING AS HIGH PRESSURE MOVES INTO THE REGION.
SPECIFICS FOR KSTL:
IFR STRATUS NEARBY AT KSUS AND KCPS AND MAY IMPACT TERMINAL EARLY
THIS MORNING. OTHERWISE...WIND SHIFT WITH COLD FRONT EXPECTED
AROUND 15Z. VFR CONDITIONS EXPECTED THIS AFTERNOON WITH THE
POTENTIAL OF A SHOWER OR STORM. CHANCES ARE TOO LOW TO INCLUDE IN
FORECAST AT THIS TIME.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (TONIGHT THROUGH SUNDAY)
ISSUED AT 345 AM CDT MON AUG 10 2015
EXPECT A FEW SHOWERS OR THUNDERSTORMS TO LINGER INTO EARLY THIS
EVENING, BUT SHOULD BE GONE BEFORE MIDNIGHT. DRIER AIR IS FORECAST
TO BUILD ACROSS THE AREA BEHIND THE FRONT TONIGHT AND TUESAY...AND
LAST AT LEAST THROUGH THE END OF THE WEEK WITH DEWPOINT
TEMPERATURES DROPPING INTO THE 60S. A HIGH AMPLITUDE UPPER LEVEL
PATTERN LOCKS THE DRY LOW LEVEL RIDGE OVER THE MISSISSIPPI VALLEY,
SO PRECIPITATION CHANCES ARE VIRTUALLY NIL. THIS SHOULD MAKE FOR
RELATIVELY COMFORTABLE WEATHER FOR WHAT ARE TYPICALLY THE DOG-DAYS
OF SUMMER WITH HIGHS NEAR OR A FEW DEGREES BELOW NORMAL IN THE MID
TO UPPER 80S AND LOWS WELL BELOW NORMAL IN THE 60S.
CARNEY
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1056 PM CDT SUN AUG 9 2015
BACKBUILDING MCS JUST EAST AND SOUTH OF THE ST LOUIS METRO AREA.
THERE MAY CONTINUE TO BE ISOLATED SHOWERS/STORMS IMPACTING THE ST
LOUIS AREA TAFS UNTIL AROUND 08Z MON. COULD NOT RULE OUT SOME
ADDITIONAL DEVELOPMENT AS WELL LATE TONIGHT/EARLY MONDAY MORNING
AS A COLD FRONT MOVES SOUTHWARD THROUGH OUR AREA LATE TONIGHT AND
MONDAY MORNING. S-SWLY SURFACE WINDS WILL VEER AROUND TO A N-NWLY
DIRECTION AFTER FROPA. THE MODEL MOS GUIDANCE WAS HINTING AT POST
FRONTAL MVFR CLOUD CEILINGS MAINLY EARLY MONDAY MORNING.
SPECIFICS FOR KSTL: ISOLATED SHOWERS AND STORMS MAY CONTINUE TO
IMPACT STL LATE TONIGHT DUE TO BACKBUILDING MCS AND AS A COLD
FRONT MOVES SOUTHWARD THROUGH STL AREA AROUND 12Z MONDAY. S-SWLY
SURFACE WINDS WILL VEER AROUND TO A NWLY DIRECTION AFTER FROPA
EARLY MONDAY MORNING. THERE WILL ALSO LIKELY BE POST FRONTAL MVFR
CIGS MONDAY MORNING.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
333 AM CDT MON AUG 10 2015
.SHORT TERM: (THROUGH LATE THIS AFTERNOON)
ISSUED AT 332 AM CDT MON AUG 10 2015
SHORT RANGE GUIDANCE SEEMS TO BE IN GOOD AGREEMENT WITH CURRENT
RADAR TRENDS IN CONTINUING TO PUSH THE BAND OF CONVECTION SOUTH OF
OUR CWFA BY 12Z. UPSTREAM DEVELOPMENT OVER SOUTHWEST MISSOURI LOOKS
LIKE IT SHOULD STAY OUT OF OUR AREA...BUT WE MAY STILL GET CLIPPED
SO HAVE KEPT MID-HIGH CHANCE POPS GOING PAST 12Z ACROSS SOUTHERN
ZONES. FURTHER NORTH, SHORT RANGE GUIDANCE HAS CONSISTENTLY BEEN
WEAKENING THE CONVECTION NOW MOVING INTO NORTHWEST MISSOURI OUT OF
IOWA, AND CURRENT RADAR TRENDS SUPPORT THIS AS WELL. THAT BEING
SAID, ISOLATED TO WIDELY SCATTERED STORMS WILL CONTINUE TO BE
POSSIBLE ACROSS THROUGH THE MORNING FROM I-70 NORTHWARD. THE ACTUAL
SYNOPTIC COLD FRONT IS DIFFICULT TO FIND AT THIS TIME, BUT LOOKS
LIKE IT SHOULD PUSH THROUGH THE AREA FROM MID MORNING THROUGH THE
AFTERNOON. RAP HAS THE 850MB FLOW TURNING SHARPLY TO THE NORTH-
NORTHWEST WITH DECENT COLD ADVECTION (FOR AUGUST) BEHIND IT. SHOULD
STILL BE ENOUGH INSTABILITY TO CONTINUE A CHANCE OF THUNDERSTORMS
THROUGH THE AFTERNOON INTO EARLY EVENING. STUCK PRETTY CLOSE TO
GUIDANCE FOR TEMPERATURES TODAY...THOUGH HIGHS WILL BE DIFFICULT TO
PIN DOWN DUE TO AFTERNOON CONVECTION.
CARNEY
.LONG TERM: (MONDAY THROUGH NEXT SUNDAY)
ISSUED AT 325 PM CDT SUN AUG 9 2015
(MONDAY THROUGH WEDNESDAY)
UPPER FLOW WILL BEGIN TO TURN OUT OF THE NORTHWEST BY TOMORROW AS
UPPER HIGH OVER OVER SOUTHERN HIGH PLAINS BEGINS TO BUILDS AND
TROUGH DIGS IN OVER THE NORTHEASTERN CONUS. THIS WILL HELP PUSH THE
SURFACE COLD FRONT THROUGH THE CWA EARLY IN THE DAY MONDAY. BOTH
THE NAM AND GFS ARE SHOWING A WEAK SHORTWAVE TROUGH MOVING ACROSS
MISSOURI AND ILLINOIS MIDDAY MONDAY. THE ASCENT FROM THE TROUGH
SHOULD BE ENOUGH TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS IN THE
INSTABILITY GENERATED BY MIDDAY OVER THE SOUTHERN CWA. ADDITIONAL
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE ACROSS
NORTHEAST MISSOURI AND WEST CENTRAL ILLINOIS DURING THE AFTERNOON AS
A SECONDARY TROUGH MOVES ACROSS IOWA. CHANCES FOR RAIN WILL DECREASE
TUESDAY AND WEDNESDAY AS THE UPPER FLOW CONTINUES TO AMPLIFY AND THE
VERTICAL MOTION BECOMES MORE SUBSIDENT AS HIGH PRESSURE BUILDS INTO
THE AREA.
MOS TEMPERATURES THE NEXT FEW DAYS ARE IN REASONABLE AGREEMENT WITH
EACH OTHER AND WITH MIXING UP TO THE 900-800MB LAYER...SO HAVE
GENERALLY FOLLOWED THEM.
(THURSDAY THROUGH SUNDAY)
EXPECT A DRY PERIOD AS AREA WILL BE DOMINATED BY A LARGE AREA OF
SURFACE HIGH PRESSURE UNDER NORTHWESTERLY UPPER FLOW ALOFT. 850MB
TEMPERATURES FROM THE GFS ENSEMBLE MEAN WILL BE IN THE 12-18C RANGE
WHICH SUPPORTS HIGHS IN THE 80S.
BRITT
&&
.AVIATION: (FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1056 PM CDT SUN AUG 9 2015
BACKBUILDING MCS JUST EAST AND SOUTH OF THE ST LOUIS METRO AREA.
THERE MAY CONTINUE TO BE ISOLATED SHOWERS/STORMS IMPACTING THE ST
LOUIS AREA TAFS UNTIL AROUND 08Z MON. COULD NOT RULE OUT SOME
ADDITIONAL DEVELOPMENT AS WELL LATE TONIGHT/EARLY MONDAY MORNING
AS A COLD FRONT MOVES SOUTHWARD THROUGH OUR AREA LATE TONIGHT AND
MONDAY MORNING. S-SWLY SURFACE WINDS WILL VEER AROUND TO A N-NWLY
DIRECTION AFTER FROPA. THE MODEL MOS GUIDANCE WAS HINTING AT POST
FRONTAL MVFR CLOUD CEILINGS MAINLY EARLY MONDAY MORNING.
SPECIFICS FOR KSTL: ISOLATED SHOWERS AND STORMS MAY CONTINUE TO
IMPACT STL LATE TONIGHT DUE TO BACKBUILDING MCS AND AS A COLD
FRONT MOVES SOUTHWARD THROUGH STL AREA AROUND 12Z MONDAY. S-SWLY
SURFACE WINDS WILL VEER AROUND TO A NWLY DIRECTION AFTER FROPA
EARLY MONDAY MORNING. THERE WILL ALSO LIKELY BE POST FRONTAL MVFR
CIGS MONDAY MORNING.
GKS
&&
.PRELIMINARY POINT TEMPS/POPS:
SAINT LOUIS 88 72 86 68 / 40 30 10 5
QUINCY 83 64 84 62 / 40 30 5 0
COLUMBIA 87 67 85 63 / 40 30 5 0
JEFFERSON CITY 89 68 86 63 / 40 30 5 0
SALEM 86 70 84 63 / 40 30 10 5
FARMINGTON 86 69 84 61 / 40 30 10 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1225 AM CDT MON AUG 10 2015
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
CHANCE FOR THUNDERSTORMS AND THEIR SEVERITY TONIGHT ARE THE PRIMARY
FORECAST CONCERNS.
THUNDERSTORMS WERE FIRING AT MID AFTERNOON ALONG A WEAK SURFACE
BOUNDARY STRETCHING FROM SOUTHEAST SOUTH DAKOTA INTO WESTERN
NEBRASKA. THESE STORMS HAVE PLENTY OF INSTABILITY AND SHEAR TO FEED
ON...SOME 2500 J/KG OF MLCAPE AND 40KT OF EFFECTIVE BULK SHEAR...AS
PER LATEST RAP OBJECTIVE ANALYSIS. ALREADY GETTING REPORTS OF SEVERE
HAIL JUST WEST OF OUR AREA WHERE VIGOROUS UPDRAFTS WERE SEEN. AND
FREEZING LEVELS ARE QUITE A BIT LOWER THAN LAST EVENING. SO A
CONTINUED HAIL THREAT IS CERTAINLY EXPECTED...WITH MODEST MICROBURST
POTENTIAL ALSO NOTED ON RAP PROGS.
PERHAPS A BIGGER SHOW WITH POTENTIALLY MORE WIDESPREAD SEVERE LATER
THIS EVENING IS POSSIBLE. MID LEVEL SHORTWAVE DIVING INTO WESTERN
SOUTH DAKOTA WILL CONTINUE SOUTHEAST THIS EVENING...PUSHING A COLD
FRONT ALONG WITH IT. SHEAR PROFILES SHOULD ACTUALLY INCREASE IN
MAGNITUDE GIVEN MID LEVEL SPEED MAX TIED TO WAVE. SHEAR VECTORS ARE
LINING UP NEARLY PARALLEL WITH EXPECTED FRONTAL/CONVECTIVE
LINE...SUPPORTING MORE OF A LINEAR STORM MODE. WIND
FIELDS...PREDICTED DOWNDRAFT CAPE AND LAYER THETA-E DIFFERENCES
APPROACHING 30 ALL SUGGEST SEVERE WIND POTENTIAL AS LINE RACES INTO
EASTERN NEBRASKA. SEVERAL MESOSCALE HI-RES MODELS ARE OFFERING
VARIED OPINIONS AROUND THIS LINE OF THINKING...SO WILL HIT EVENING
THUNDER CHANCES PRETTY HARD. EXPECT STORMS TO SLOWLY DIE OFF LATER
THIS EVENING AND OVERNIGHT AS THEY APPROACH INTERSTATE 80 AND
BEYOND...HOWEVER SEVERE THREAT APPEARS TO LINGER FOR SOME TIME AFTER
DARK.
BY MONDAY MORNING LINGERING STORMS SHOULD BE EXITING OUR
SOUTHEAST CWA. HOWEVER WEAK IMPULSE IN MID LEVEL FLOW COULD TAP
WANING INSTABILITY IN THE MID AFTERNOON TO PRODUCE A STORM OR TWO
IN SOUTHWEST IOWA. THEN NORTHERLY SURFACE FLOW UNDER HIGH PRESSURE
WILL FORETELL A RELATIVELY DRY PERIOD OVER THE NEXT COUPLE OF
DAYS.
HIGHS BOTH TUESDAY AND WEDNESDAY WILL GRADUALLY INCREASE INTO THE
LOWER AND MIDDLE 80S UNDER PLENTY OF SUNSHINE. AND DEW POINTS SHOULD
BE LOWER ON TUESDAY BEFORE BEGINNING TO RETURN WEDNESDAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 333 PM CDT SUN AUG 9 2015
OUR RELATIVELY QUIET WEATHER PATTERN IS EXPECTED TO CONTINUE THROUGH
THE REST OF THE WEEK. MID LEVEL HIGH PRESSURE RIDGE IS FORECAST BY
BOTH ECMWF AND GFS TO BUILD FROM THE SOUTHERN PLAINS INTO THE
NORTHERN ROCKIES...AND EXPAND A BIT TO THE EAST. THIS WILL TAKE MAIN
STORM TRACK NORTH AND EAST OF OUR AREA...AND ALLOW FOR WARMER
TEMPERATURES BOTH AT THE SURFACE AND ALOFT. WILL MAINTAIN OUR DRY
FORECAST UNTIL MAYBE SATURDAY NIGHT OR SUNDAY WHEN RIDGE IS FORECAST
TO BEGIN TO BREAK DOWN. HIGHS MAINLY IN THE UPPER 80S AND LOWER 90S
SHOULD PREVAIL.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1223 AM CDT MON AUG 10 2015
THUNDERSTORMS AFFECTING KOMA WERE MOVING AWAY AND WILL
EAST/SOUTHEAST OF THE TAF SITE BEFORE 06Z. OTHERWISE...THERE WILL
BE A CHANCE OF ADDITIONAL THUNDERSTORMS IN THE AREA...BUT NOT
CONFIDENT ENOUGH THAT STORMS WOULD DIRECTLY IMPACT ANY TAF
LOCATIONS. OCCASIONAL MVFR CONDITIONS AT ALL THREE TAF SITES
THROUGH ABOUT 13-15Z...THEN VFR AFTER THAT.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...DERGAN
LONG TERM...DERGAN
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS ELKO NV
345 PM PDT MON AUG 10 2015
.SYNOPSIS...POCKETS OF MOISTURE AND INSTABILITY WILL FUEL
THUNDERSTORM ACTIVITY. CONVECTION IS EXPECTED THIS AFTERNOON AND
EVENING OVER PORTIONS OF NORTHEASTERN NEVADA. TEMPERATURES WILL
BE NEAR NORMAL. EXPECTING ANOTHER MONSOON SURGE THIS WEEK.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY. KLRX HAS BEEN ACTIVE OVER
ELKO COUNTY THIS AFTERNOON. THE JET IS DIRECTLY OVER THE LKN
CWA...PROVIDING SUFFICIENT UPWARD VERTICAL VELOCITY OVER NE NV.
QPF-WISE...THE HRRR IS OVER DONE SOUTH OF I-80...THE NAM IS OVER
DONE IN LANDER AND EUREKA COUNTIES AND THE GFS IS UNDER DONE FOR
ALL THE EASTERN ZONES THIS AFTERNOON AND EVENING. THE MODELS
CONTINUE TO STRUGGLE WITH THE ENERGY BEING EJECTED FROM THE
PACIFIC LOW AND THE PLACEMENT OF THE MOISTURE.
TOMORROW...EXPECTING THE MONSOON SURGE TO MOVE ACROSS ARIZONA AND
INTO THE EASTERN GREAT BASIN THIS FORECAST PERIOD. THE NAM HAS THE
FETCH OF MOISTURE BISECTING CENTRAL NV AND THE GFS KEEPS IT
RESTRICTED TO THE EASTERN GREAT BASIN. THE NCEP RMOP IS ALSO
DEPICTING MODELING ISSUES AS EARLY AS 24 HRS. THE NAEFS ANOMALIES
ARE PINGING INTO A STRONG IVT...WITH A 30 YEAR RETURN INTERVAL FOR
WEDNESDAY. IF THAT VERIFIES...IT WOULD TRANSLATE INTO POTENTIAL
FLOODING ISSUES NEAR THE BORDER OF UTAH...BUT THAT SHOULD BE
TEMPERED WITH THE VAGARIES OF THE MODELS PERFORMANCES THE PAST
SEVERAL DAYS. NO SHORTAGE OF UNCERTAINTY THIS PERIOD...BUT ALSO
SOME POTENTIALLY INTERESTING WEATHER ON THE HORIZON. STAY TUNED
FOR MORE DETAILS.
.LONG TERM...WEDNESDAY NIGHT THROUGH NEXT MONDAY. THE MODELS HAVE
DISAGREED ON TIMING...STRENGTH...POSITION AND JUST ABOUT EVERYTHING
ELSE FOR A WEEK...COMING A LITTLE CLOSER EACH DAY. TODAY...THEY SEEM
TO BE IN ALMOST PERFECT AGREEMENT. MODERATELY SERIOUS DISAGREEMENT
DOES NOT APPEAR UNTIL SUNDAY NIGHT.
MAJOR MODELS HAVE A SLUG OF QUASI-MONSOON MOISTURE EXITING THE
REGION WEDNESDAY NIGHT WITH SOME LEFTOVER CONVECTION IN THE EASTERN
BORDERLANDS. THIS SLIDES ON EAST AND A DRY SOUTHWEST FLOW SETS UP
FOR THE REMAINDER. THERE WILL NO DOUBT BE AN ISOLATED DRY STORM NOW
AND THEN WITH HEAT AND SOME ELEVATED MOISTURE AND HUMIDITY. BUT HAVE
KEPT POPS LOW ENOUGH AFTER THURSDAY TO ESSENTIALLY ELIMINATE MENTION
OF SENSIBLE WEATHER.
TEMPS REMAIN NEAR TO SLIGHTLY ABOVE NORMAL. WINDS WILL KICK UP
THURSDAY AND WITH LOW RH`S COULD SEE SOME FIRE WEATHER PROBLEMS.
&&
.AVIATION...VFR CONDITIONS ARE EXPECTED AT KWMC KEKO KELY AND KTPH
THROUGH TUESDAY AFTERNOON. ISOLATED THUNDERSTORMS WILL CONTINUE TO
MOVE THROUGH EASTERN NEVADA THIS AFTERNOON AND EARLY
EVENING...AFFECTING MAINLY KEKO AND DISTANTLY KELY. THE USUAL GUSTY
WINDS AROUND STORMS...SHOWERS...AND VIRGA. DIMINISH OVERNIGHT BUT
FIRE UP AGAIN TUESDAY AFTERNOON.
&&
.FIRE WEATHER...MULTIPLE THUNDERSTORMS HAVE POPPED UP OVER 469 AND
470 TODAY. EXPECTING ACTIVITY TO TAPER OFF THIS EVENING. THE NEXT
CONVECTIVE PUSH WILL BE MONSOONAL IN NATURE...ALTHOUGH WETTING
RAINS WILL BE PROBABLE...ALTHOUGH NOT NECESSARILY COINCIDENT WITH
THE LIGHTNING STRIKES.
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
97/98/98/97
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
133 AM EDT MON AUG 10 2015
.SYNOPSIS...
DRY WEATHER AND SEASONAL TEMPERATURES WILL CONTINUE TONIGHT AND
MONDAY AS HIGH PRESSURE REMAINS OVER THE REGION, BUT CONDITIONS TAKE
A TURN FOR THE WORSE MONDAY NIGHT THROUGH TUESDAY NIGHT AS LOW
PRESSURE TRACKS OVER THE REGION. A WIDESPREAD RAIN EVENT IS EXPECTED
WITH STORM TOTALS OF A HALF TO ONE AND A HALF INCHES OF RAIN.
CHANCES FOR SHOWERS CONTINUE INTO WEDNESDAY BEFORE DRIER CONDITIONS
RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 116 AM EDT MONDAY...UPDATED TO CAPTURE LATEST TEMP/DWPT/WIND
AND SKY CONDITIONS. SOME PATCHY FOG ALREADY DEVELOPING WILL
CONTINUE TO SPREAD IN AREAL COVERAGE ACRS THE DEEPER PROTECTED
RIVER VALLEYS WITH TEMPS FALLING BACK INTO THE U40S DACKS TO L/M
50S SLV/NEK/CENTRAL VT TO NEAR 60F CPV.
MINOR ADJUSTMENTS TO SKY COVER AND MINIMUM TEMPERATURES (REALLY
AT THE NOISE LEVEL) TO COVER CURRENT OBSERVATIONAL TRENDS. A FEW
SPOTS IN THE ST LAWRENCE VALLEY WERE ALREADY WITHIN A DEGREE OF
FORECAST MINIMUM TEMPERATURES SO I DID LOWER THOSE VALUES BY A FEW
DEGREES. ALSO INCORPORATED LATEST RAP UPPER LEVEL RH PROGS INTO
THE CLOUD FORECAST OVERNIGHT, SHOWING AT LEAST SOME CI/CS
OVERSPREADING THE REGION FROM WEST TO EAST AFTER MIDNIGHT, THOUGH
BY AND LARGE CLEAR TO PARTLY CLOUDY SKIES WILL STILL BE THE
PREVAILING RULE. HAVE A GREAT NIGHT.
PRIOR DISCUSSION FROM 738 PM EDT SUNDAY... MINOR ADJUSTMENTS TO
FORECAST AS OF 700 PM, MAINLY TO KEEP 10-20% POPS ACROSS NC/NE VT
THROUGH 9 PM OR SO TO ACCOUNT FOR CURRENT WIDELY SCT SHOWER
ACTIVITY WHICH HAS SURPRISINGLY INCREASED IN AREAL COVERAGE OVER
THE PAST HOUR OR SO. THIS ACTIVITY IS DEVELOPING IN WEAKLY
CONVERGENT LOW TO MID LEVEL FLOW ALONG A DIFFUSE SFC
TROUGH/BACKDOOR FRONT ORIENTED NNW TO SSE ACROSS SOUTHERN QUEBEC
INTO NORTHEASTERN VT AND SOUTHWARD INTO CENTRAL NH WHERE IT
BECOMES DIFFICULT TO IDENTIFY. GIVEN THIS ACTIVITY AND ALLOWING
FOR SCATTERED AREAS OF WET GROUND TO FOSTER ENHANCED SFC MOISTURE
FLUXES OVERNIGHT I ALSO INTRODUCED SLIGHTLY HIGHER COVERAGE OF
BR/FG ACROSS THIS AREA WHICH LATEST BTV4/BTV6 KM OUTPUT SHOWS
QUITE NICELY. OTHERWISE INHERITED FORECAST REMAINS IN GOOD SHAPE
SHOWING MAINLY CLR/PTLY CLOUDY SKIES OVERNIGHT (OUTSIDE THE FOG)
AS TEMPERATURES BOTTOM OUT IN THE 50S TO AROUND 60 BY SUNRISE
MONDAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 355 PM EDT SUNDAY...MONDAY WILL BE OUR LAST DAY OF THIS
NICE STRETCH OF WEATHER AS ALL AVAILABLE GUIDANCE IS IN GOOD
AGREEMENT SHOWING THE BEST LOW/MID LEVEL MOISTURE AND FORCING
ASSOCIATED WITH OUR NEXT SYSTEM IS WEST OF THE AREA THROUGH 00Z
TUESDAY. AFTER MORNING FOG BURNS OFF WE`LL SEE INCREASING CLOUDS
FROM THE WEST WHICH MAY TEMPER AFTERNOON TEMPS, BUT PROGGED 850MB
TEMPS OF 12-14C WILL SUPPORT HIGHS IN THE UPPER 70S MOUNTAINS TO
LOW/MID 80S IN THE VALLEYS.
AS MENTIONED, ALL GUIDANCE IS IN GOOD AGREEMENT HANDLING A DEEPENING
MID/UPPER TROUGH ACROSS THE GREAT LAKES AND SURFACE LOW TRACKING
FROM THE OHIO VALLEY MONDAY NIGHT AND ACROSS THE BTV CWA TUESDAY.
00Z GFS CAME AROUND TO THE NAM/ECMWF/CMC SLOWER TIMING AND THE 12Z
RUNS SLOWED THE ARRIVAL OF DEEP LAYER MOISTURE EVEN FURTHER TO NOW
AFTER MIDNIGHT. HEAVIEST QPF AXIS CONTINUES TO POINT TOWARDS
NORTHERN NEW YORK WHERE 1-1.5" STORM TOTAL IS EXPECTED THROUGH
TUESDAY, WHILE POINTS EASTWARD WILL BE GENERALLY LESS THAN AN INCH
WITH SOME DOWNSLOPING EFFECTS EXPECTED ACROSS PORTIONS OF THE
GREEN MOUNTAINS ASSOCIATED WITH A LOW LEVEL SOUTHEASTERLY JET OF
40-50 KNOTS IMPACTING THE AREA TUESDAY. SOUNDINGS CONTINUE TO SHOW
THESE RIDGETOP WINDS ARE ABOVE THE INVERSION LEVEL AROUND 2000
FT, SO NOT EXPECTING STRONG GUSTS REACHING THE SURFACE, BUT 25-35
MPH SEEM REASONABLE ALONG THE FAVORED LOCALES OF THE WESTERN
SLOPES FROM RUTLAND TO UNDERHILL. CAN`T RULE OUT A FEW RUMBLES OF
THUNDER THROUGH THE EVENT EITHER WITH MODELS SHOWING SOME SLIGHT
ELEVATED INSTABILITY BUT AREAL COVERAGE SHOULD BE PRETTY LIMITED.
TUESDAY NIGHT THE SURFACE LOW TRACKS EAST OF THE REGION WITH A MID-
LEVEL DRY SLOT SHIFTING OVER THE REGION. PRECIP WILL END FROM WEST
TO EAST BY MIDNIGHT, WITH CONDITIONS GENERALLY DRY THROUGH SUNRISE.
MID-LEVEL HEIGHTS/THICKNESS DON`T FALL MUCH SO IT WILL BE A MILD
NIGHT UNDER PLENTY OF CLOUD COVER WITH LOWS IN THE UPPER 50S TO MID
60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 259 PM EDT SUNDAY...UNSETTLED WEATHER CONTINUES THROUGH THE
EXTENDED PERIOD WITH UPPER TROUGH REMAINING IN PLACE OVER THE
NORTHEAST AND PASSAGE OF ANOTHER SURFACE FRONT ON FRIDAY.
STARTING 12Z WEDNESDAY...SURFACE FRONT WILL HAVE PASSED ON TO THE
EAST WITH A WESTERLY LOW LEVEL FLOW. 500 MB TROUGH LAGGING BEHIND
SURFACE FEATURE AND WILL BE SETTLING IN ON WEDNESDAY. COMBINATION
OF COLD POOL ALOFT, LOW LEVEL UPSLOPE FLOW, AND MOISTURE TRAPPED
IN THE LOW LEVELS WILL RESULT IN MAINLY DAYTIME SHOWERS IN THE
RESULTING INSTABILITY AND LIFT.
IF ANY TIME WILL BE QUIET IT WOULD BE THURSDAY WHEN THE REGION IS
BETWEEN SYSTEMS. UPPER LOW GETS KICKED OUT AS NEXT LOW APPROACHES,
AND AN AREA OF SHORTWAVE RIDGING PASSES OVER. WESTERLY UPSLOPE LOW
LEVEL FLOW TURNS MORE SOUTHERLY BY END OF DAY, AND A BAND OF DRIER
AIR MOVES IN TO MINIMIZE CHANCES FOR RAIN. FRIDAY HAS RAIN CHANCES
AGAIN WHEN COLD FRONT MOVES THROUGH AT THE SURFACE AGAIN AND UPPER
SHORTWAVE THAT MOVED DOWN IN THE NORTHWEST FLOW DROPS INTO THE
BASE OF THE MEAN TROUGH. CHANCE FOR SHOWERS INTO SATURDAY WITH
SAME POST FRONTAL SCENARIO OF INSTABILITY DRIVEN BY COLD POOL
ALOFT AND LIFT FROM LOW LEVEL UPSLOPE FLOW.
MENTIONED THUNDER ON WEDNESDAY AND FRIDAY AS CAPE, MEAGER THOUGH
IT IS, INCREASES TO 250-500 J/KG AND COULD GET ENOUGH VERTICAL
DEVELOPMENT FOR LIGHTNING. NOT MUCH CHANGE IN TEMPERATURES
THROUGHOUT, WE NEVER GET MUCH CHANCE TO WARM APPRECIABLY, AND THE
AIR BEHIND THE FRONTS IS NOT PARTICULARLY COOL EITHER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
THROUGH 06Z TUESDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR OVERNIGHT INTO EARLY MONDAY MORNING AT
MPV/SLK/MSS. SCT CUMULUS FIELD WILL GRADUALLY DIMINISH OVERNIGHT.
THIS CLEARING WILL ALLOW FOR THE FORMATION OF FOG/BR AT SLK/MPV/MSS.
DENSEST AND MOST PERSISTENT FOG EXPECTED AT MPV BETWEEN 07Z AND 13Z.
AFTER 12-13Z MONDAY MORNING EXPECTING BOTH SCATTERED HIGH CIRRUS TO
FILTER ACROSS AS WELL AS THE DEVELOPMENT OF ADDITIONAL CUMULUS
CLOUDS BY AFTERNOON. CLOUD COVERAGE INCREASES AREA-WIDE MONDAY
EVENING. A FEW RAIN SHOWERS ARE POSSIBLE AT SLK AFTER 21Z.
COVERAGE OF RAIN SHOWERS INCREASES ACROSS NORTHERN NY BETWEEN
00-06Z TUESDAY...AFFECTING SLK/MSS/PBG. LIGHT AND LOCALLY
VARIABLE WINDS (EXCEPT SE DRAINAGE AT RUT) BECOME SOUTHERLY FROM
5-8 KNOTS ON MONDAY.
OUTLOOK 06Z TUESDAY THROUGH FRIDAY...
06Z TUE - 00Z WED...DETERIORATING CONDITIONS LIKELY (MVFR
POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND STRATUS.
00Z WED - 00Z THU...VFR WITH PERIODS OF MVFR IN LINGERING
SCATTERED SHOWERS.
00Z THU - 00Z FRI...VFR WITH A FEW SCATTERED RAIN SHOWERS STILL
POSSIBLE.
00Z FRI ONWARD...VFR WITH PERIODS MVFR IN SCATTERED SHOWERS ALONG
A COLD FRONT...MAINLY AFTER 18Z.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/TABER
SHORT TERM...LAHIFF
LONG TERM...HANSON
AVIATION...RJS/MUCCILLI
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
118 AM EDT MON AUG 10 2015
.SYNOPSIS...
DRY WEATHER AND SEASONAL TEMPERATURES WILL CONTINUE TONIGHT AND
MONDAY AS HIGH PRESSURE REMAINS OVER THE REGION, BUT CONDITIONS TAKE
A TURN FOR THE WORSE MONDAY NIGHT THROUGH TUESDAY NIGHT AS LOW
PRESSURE TRACKS OVER THE REGION. A WIDESPREAD RAIN EVENT IS EXPECTED
WITH STORM TOTALS OF A HALF TO ONE AND A HALF INCHES OF RAIN.
CHANCES FOR SHOWERS CONTINUE INTO WEDNESDAY BEFORE DRIER CONDITIONS
RETURN FOR THE END OF THE WORK WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 116 AM EDT MONDAY...UPDATED TO CAPTURE LATEST TEMP/DWPT/WIND
AND SKY CONDITIONS. SOME PATCHY FOG ALREADY DEVELOPING WILL
CONTINUE TO SPREAD IN AREAL COVERAGE ACRS THE DEEPER PROTECTED
RIVER VALLEYS WITH TEMPS FALLING BACK INTO THE U40S DACKS TO L/M
50S SLV/NEK/CENTRAL VT TO NEAR 60F CPV.
MINOR ADJUSTMENTS TO SKY COVER AND MINIMUM TEMPERATURES (REALLY
AT THE NOISE LEVEL) TO COVER CURRENT OBSERVATIONAL TRENDS. A FEW
SPOTS IN THE ST LAWRENCE VALLEY WERE ALREADY WITHIN A DEGREE OF
FORECAST MINIMUM TEMPERATURES SO I DID LOWER THOSE VALUES BY A FEW
DEGREES. ALSO INCORPORATED LATEST RAP UPPER LEVEL RH PROGS INTO
THE CLOUD FORECAST OVERNIGHT, SHOWING AT LEAST SOME CI/CS
OVERSPREADING THE REGION FROM WEST TO EAST AFTER MIDNIGHT, THOUGH
BY AND LARGE CLEAR TO PARTLY CLOUDY SKIES WILL STILL BE THE
PREVAILING RULE. HAVE A GREAT NIGHT.
PRIOR DISCUSSION FROM 738 PM EDT SUNDAY... MINOR ADJUSTMENTS TO
FORECAST AS OF 700 PM, MAINLY TO KEEP 10-20% POPS ACROSS NC/NE VT
THROUGH 9 PM OR SO TO ACCOUNT FOR CURRENT WIDELY SCT SHOWER
ACTIVITY WHICH HAS SURPRISINGLY INCREASED IN AREAL COVERAGE OVER
THE PAST HOUR OR SO. THIS ACTIVITY IS DEVELOPING IN WEAKLY
CONVERGENT LOW TO MID LEVEL FLOW ALONG A DIFFUSE SFC
TROUGH/BACKDOOR FRONT ORIENTED NNW TO SSE ACROSS SOUTHERN QUEBEC
INTO NORTHEASTERN VT AND SOUTHWARD INTO CENTRAL NH WHERE IT
BECOMES DIFFICULT TO IDENTIFY. GIVEN THIS ACTIVITY AND ALLOWING
FOR SCATTERED AREAS OF WET GROUND TO FOSTER ENHANCED SFC MOISTURE
FLUXES OVERNIGHT I ALSO INTRODUCED SLIGHTLY HIGHER COVERAGE OF
BR/FG ACROSS THIS AREA WHICH LATEST BTV4/BTV6 KM OUTPUT SHOWS
QUITE NICELY. OTHERWISE INHERITED FORECAST REMAINS IN GOOD SHAPE
SHOWING MAINLY CLR/PTLY CLOUDY SKIES OVERNIGHT (OUTSIDE THE FOG)
AS TEMPERATURES BOTTOM OUT IN THE 50S TO AROUND 60 BY SUNRISE
MONDAY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY NIGHT/...
AS OF 355 PM EDT SUNDAY...MONDAY WILL BE OUR LAST DAY OF THIS
NICE STRETCH OF WEATHER AS ALL AVAILABLE GUIDANCE IS IN GOOD
AGREEMENT SHOWING THE BEST LOW/MID LEVEL MOISTURE AND FORCING
ASSOCIATED WITH OUR NEXT SYSTEM IS WEST OF THE AREA THROUGH 00Z
TUESDAY. AFTER MORNING FOG BURNS OFF WE`LL SEE INCREASING CLOUDS
FROM THE WEST WHICH MAY TEMPER AFTERNOON TEMPS, BUT PROGGED 850MB
TEMPS OF 12-14C WILL SUPPORT HIGHS IN THE UPPER 70S MOUNTAINS TO
LOW/MID 80S IN THE VALLEYS.
AS MENTIONED, ALL GUIDANCE IS IN GOOD AGREEMENT HANDLING A DEEPENING
MID/UPPER TROUGH ACROSS THE GREAT LAKES AND SURFACE LOW TRACKING
FROM THE OHIO VALLEY MONDAY NIGHT AND ACROSS THE BTV CWA TUESDAY.
00Z GFS CAME AROUND TO THE NAM/ECMWF/CMC SLOWER TIMING AND THE 12Z
RUNS SLOWED THE ARRIVAL OF DEEP LAYER MOISTURE EVEN FURTHER TO NOW
AFTER MIDNIGHT. HEAVIEST QPF AXIS CONTINUES TO POINT TOWARDS
NORTHERN NEW YORK WHERE 1-1.5" STORM TOTAL IS EXPECTED THROUGH
TUESDAY, WHILE POINTS EASTWARD WILL BE GENERALLY LESS THAN AN INCH
WITH SOME DOWNSLOPING EFFECTS EXPECTED ACROSS PORTIONS OF THE
GREEN MOUNTAINS ASSOCIATED WITH A LOW LEVEL SOUTHEASTERLY JET OF
40-50 KNOTS IMPACTING THE AREA TUESDAY. SOUNDINGS CONTINUE TO SHOW
THESE RIDGETOP WINDS ARE ABOVE THE INVERSION LEVEL AROUND 2000
FT, SO NOT EXPECTING STRONG GUSTS REACHING THE SURFACE, BUT 25-35
MPH SEEM REASONABLE ALONG THE FAVORED LOCALES OF THE WESTERN
SLOPES FROM RUTLAND TO UNDERHILL. CAN`T RULE OUT A FEW RUMBLES OF
THUNDER THROUGH THE EVENT EITHER WITH MODELS SHOWING SOME SLIGHT
ELEVATED INSTABILITY BUT AREAL COVERAGE SHOULD BE PRETTY LIMITED.
TUESDAY NIGHT THE SURFACE LOW TRACKS EAST OF THE REGION WITH A MID-
LEVEL DRY SLOT SHIFTING OVER THE REGION. PRECIP WILL END FROM WEST
TO EAST BY MIDNIGHT, WITH CONDITIONS GENERALLY DRY THROUGH SUNRISE.
MID-LEVEL HEIGHTS/THICKNESS DON`T FALL MUCH SO IT WILL BE A MILD
NIGHT UNDER PLENTY OF CLOUD COVER WITH LOWS IN THE UPPER 50S TO MID
60S.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 259 PM EDT SUNDAY...UNSETTLED WEATHER CONTINUES THROUGH THE
EXTENDED PERIOD WITH UPPER TROUGH REMAINING IN PLACE OVER THE
NORTHEAST AND PASSAGE OF ANOTHER SURFACE FRONT ON FRIDAY.
STARTING 12Z WEDNESDAY...SURFACE FRONT WILL HAVE PASSED ON TO THE
EAST WITH A WESTERLY LOW LEVEL FLOW. 500 MB TROUGH LAGGING BEHIND
SURFACE FEATURE AND WILL BE SETTLING IN ON WEDNESDAY. COMBINATION
OF COLD POOL ALOFT, LOW LEVEL UPSLOPE FLOW, AND MOISTURE TRAPPED
IN THE LOW LEVELS WILL RESULT IN MAINLY DAYTIME SHOWERS IN THE
RESULTING INSTABILITY AND LIFT.
IF ANY TIME WILL BE QUIET IT WOULD BE THURSDAY WHEN THE REGION IS
BETWEEN SYSTEMS. UPPER LOW GETS KICKED OUT AS NEXT LOW APPROACHES,
AND AN AREA OF SHORTWAVE RIDGING PASSES OVER. WESTERLY UPSLOPE LOW
LEVEL FLOW TURNS MORE SOUTHERLY BY END OF DAY, AND A BAND OF DRIER
AIR MOVES IN TO MINIMIZE CHANCES FOR RAIN. FRIDAY HAS RAIN CHANCES
AGAIN WHEN COLD FRONT MOVES THROUGH AT THE SURFACE AGAIN AND UPPER
SHORTWAVE THAT MOVED DOWN IN THE NORTHWEST FLOW DROPS INTO THE
BASE OF THE MEAN TROUGH. CHANCE FOR SHOWERS INTO SATURDAY WITH
SAME POST FRONTAL SCENARIO OF INSTABILITY DRIVEN BY COLD POOL
ALOFT AND LIFT FROM LOW LEVEL UPSLOPE FLOW.
MENTIONED THUNDER ON WEDNESDAY AND FRIDAY AS CAPE, MEAGER THOUGH
IT IS, INCREASES TO 250-500 J/KG AND COULD GET ENOUGH VERTICAL
DEVELOPMENT FOR LIGHTNING. NOT MUCH CHANGE IN TEMPERATURES
THROUGHOUT, WE NEVER GET MUCH CHANCE TO WARM APPRECIABLY, AND THE
AIR BEHIND THE FRONTS IS NOT PARTICULARLY COOL EITHER.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
THROUGH 00Z TUESDAY...MAINLY VFR EXPECTED...WITH THE EXCEPTION OF
SOME IFR/LIFR FOG/BR AGAIN LATE TONIGHT/EARLY MONDAY MORNING AT
MPV/SLK/MSS. SCT CUMULUS FIELD FROM THIS AFTERNOON AND EVENING
WILL GRADUALLY DIMINISH THROUGH THE REMAINDER OF THE EVENING AND
OVERNIGHT HOURS. THIS CLEARING WILL ALLOW FOR THE FORMATION OF
FOG/BR AT SLK/MPV/MSS. DENSEST AND MOST PERSISTENT FOG EXPECTED AT
MPV BETWEEN 07Z AND 13Z. AFTER 12-13Z MONDAY MORNING EXPECTING
BOTH SCATTERED HIGH CIRRUS TO FILTER ACROSS AS WELL AS THE
DEVELOPMENT OF ADDITIONAL CUMULUS CLOUDS BY AFTERNOON. A FEW
SCATTERED RAIN SHOWERS ARE EVEN POSSIBLE AT SLK AFTER 21Z. LIGHT
AND LOCALLY VARIABLE WINDS (EXCEPT SE DRAINAGE AT RUT) BECOME
SOUTHERLY FROM 5-8 KNOTS ON MONDAY.
OUTLOOK 00Z TUESDAY THROUGH FRIDAY...
00Z TUESDAY THROUGH 00Z WEDNESDAY...DETERIORATING CONDITIONS
LIKELY (MVFR POSSIBLE IFR) WITH PERIODS OF RAIN SHOWERS AND
STRATUS.
00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR WITH PERIODS OF MVFR IN
LINGERING SCATTERED SHOWERS.
00Z THURSDAY-00Z FRIDAY...VFR WITH A FEW SCATTERED RAIN SHOWERS
STILL POSSIBLE.
00Z FRIDAY ONWARD...VFR WITH PERIODS MVFR IN SCATTERED
SHOWERS ALONG A COLD FRONT...MAINLY AFTER 18Z.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LAHIFF
NEAR TERM...JMG/TABER
SHORT TERM...LAHIFF
LONG TERM...HANSON
AVIATION...MUCCILLI
AREA FORECAST DISCUSSION...COR
NWS WILMINGTON NC
304 PM EDT MON AUG 10 2015
.SYNOPSIS...
RAIN CHANCES WILL INCREASE TUESDAY AND EXTEND INTO WEDNESDAY AS
A COLD FRONT MAKES ITS WAY INTO THE AREA. HIGH PRESSURE WILL
BUILD IN BEHIND THE FRONT LATE WEDNESDAY...OFFERING SEASONABLE
AND MAINLY DRY CONDITIONS INTO NEXT WEEKEND. A CHANCE OF RAIN
MAY RETURN EARLY NEXT WEEK AS HIGH PRESSURE MOVES OFFSHORE AND
DIRECTS MOISTURE ONSHORE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...CLOUD COVER HAS BEEN PRETTY EXTENSIVE ACROSS
THE INLAND HALF OF THE CWA...BUT COASTAL SECTIONS HAVE ONCE AGAIN
EXPERIENCED A GREAT EARLY-AUGUST DAY. MOISTURE WILL CONTINUE TO
INCREASE IN BOTH THE MID-LEVELS AND AT THE SURFACE...FINALLY
OVERCOMING THE VERY DRY AIR IN PLACE AS THE SURFACE RIDGE OVERHEAD
SHIFTS OFFSHORE. SHOWERS THAT HAD DEVELOPED WEST OF THE CWA HAVE
ERODED AS EXPECTED THANKS TO ENCOUNTERING DRY AIR...AND HIGH RES
GUIDANCE INCLUDING THE HRRR AND NSSL WRF BOTH KEEP THE CWA DRY
THROUGH TONIGHT. HAVE REMOVED MENTION OF POP FROM EVEN IN THE FAR
INLAND ZONES THROUGH DARK TO ACCOUNT FOR TRENDS IN SATELLITE AND
RADAR.
TONIGHT...COLUMN SATURATION WILL CONTINUE TO INCREASE WITH PWATS
RISING TOWARDS 2 INCHES BY TUESDAY MORNING. COLD FRONT APPROACHING
FROM THE WEST WILL BE NEAR THE CWA BY MORNING...WITH SHOWERS AND
THUNDERSTORMS INCREASING AHEAD OF IT. FORECAST PROFILES SUGGEST
ENOUGH SATURATION INLAND THAT POP HAS BEEN RAMPED UP TO HIGH CHC
FROM I-95 WESTWARD BY 8AM TUESDAY...WITH JUST SCHC ALONG THE
COAST...BUT MOST OF THE PRECIP WILL HOLD OFF UNTIL AFTER THIS PERIOD.
INCREASING CLOUD COVER AND CONTINUED LIGHT SOUTHERLY WINDS WILL KEEP
MINS ELEVATED TO ABOVE SEASONABLE NORMS TONIGHT. THE MAV AND MET ARE
IN GOOD AGREEMENT...AND HAVE FORECAST MORE CLOSELY TO THE SLIGHTLY
WARMER MAV NUMBERS. EXPECT LOWS IN THE 72-75 DEGREE RANGE THROUGHOUT
THE AREA.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...THE PRIME WEATHER CAPTION FOR TUE/WED IS RAIN
AS AN APPROACHING FRONTAL SYSTEM WITH RELATIVELY HIGH AMOUNTS OF
INGESTED PRECIPITABLE WATER...CROSSES THE APPALACHIAN MOUNTAINS
EARLY TUESDAY AND MOVES TO THE COAST TUESDAY NIGHT. IT APPEARS A
WEAK WAVE OF LOW PRESSURE MOVING NNE ALONG THE FRONT MAY SUSTAIN
ISOLATED COASTAL SHOWERS SLIGHTLY BEHIND THE DECAYING FRONTAL SYSTEM
ON WEDNESDAY. BEST FIT AND CONSENSUS QPF DEPICTIONS OF STORM/SYSTEM
TOTAL POINTS GENERALLY TO 0.50-0.75 INCHES OF RAIN TUE/WED AND
HIGHEST ALONG AREAS IN PROXIMITY TO THE COAST. A TREND OF DRYING
WILL PREVAIL ON WEDNESDAY ESPECIALLY INLAND...IN THE FACE OF
ISOLATED COASTAL SHOWERS.
POST-FRONTAL DOWNSLOPE WIND FLOW WEDNESDAY WITH LITTLE COLD AIR
ADVECTION WILL LIKELY RESULT IN A SEASONABLY WARM DAY WEDNESDAY
ALTHOUGH WE WILL OBSERVE SEVERAL DEGREES OF DEWPOINT DROPS THROUGH
WEDNESDAY...TAKING A SLIGHT EDGE OFF THE HUMIDITY LEVELS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 3 PM MONDAY...MID LEVEL TROUGHING WILL PERSIST ACROSS THE
EAST/SOUTHEAST THROUGH SATURDAY WITH MORE OF A ZONAL PATTERN
DEVELOPING THEREAFTER. GENERALLY QUIET WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES FROM THE MIDWEST TO THE APPALACHIANS THROUGH THE
PERIOD. THE HIGH WILL WEAKEN WITH THE MID LEVEL TROUGH THUS LEAVING
A WEAK PRESSURE PATTERN BOTH AT THE SURFACE AND ALOFT. HAVE
CONTINUED THE SLIGHT CHANCE POPS WHICH ARE MOSTLY CONFINED TO THE
COASTAL AND OFFSHORE ZONES. THE TEMPERATURE CURVE FOLLOWS THE SAME
PROGRESSION WITH COOL READINGS EARLY ON...FRIDAY SHOULD BE THE
COOLEST WITH 850MB TEMPERATURES NEAR 15 DEGREES C. THERMAL PROFILES
SLOWLY MODIFY FROM THAT POINT ON. READINGS MAY ECLIPSE CLIMATOLOGY
JUST BY A DEGREE OR TWO BY THE END OF THE PERIOD.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 18Z...A BIT TRICKY WITH RESPECT TO PRECIP THIS AFTERNOON.
CONVECTION ONGOING JUST WEST OF THE REGION AND THE MODELS ARE
SIMILAR IN BRINGING THE CONVECTION TO THE I-95 CORRIDOR...BUT
MOISTURE IS LIMITED AND HAVE REMOVED ANY MENTION OF SHOWERS DURING
THE DAYLIGHT HOURS. TONIGHT...ISOLATED CONVECTION POSSIBLE OVER
THE WESTERN THIRD OF THE REGION...WITH MID CLOUD CEILINGS DUE TO
CONVECTIVE DEBRIS. TUESDAY...SHOWERS ON THE INCREASE AS YET
ANOTHER COLD FRONT APPROACHES. CONVECTION COULD BECOME NUMEROUS
AFTER THE END OF THE FORECAST PERIOD WITH FRONTAL LIFT AND
INSTABILITY.
EXTENDED OUTLOOK...SCATTERED SHOWERS AND STORMS TUESDAY NIGHT WITH
INTERMITTENT MVFR/IFR CONDITIONS. BECOMING VFR WEDNESDAY WITH
ISOLATED MORNING CONVECTION. VFR THURSDAY THROUGH SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM MONDAY...WEAK RIDGE OF HIGH PRESSURE WILL SLOWLY SHIFT
OFFSHORE TONIGHT...SO ALTHOUGH THE GRADIENT WILL REMAIN LIGHT
KEEPING WIND SPEEDS TO 10 KTS OR LESS...DIRECTION WILL CONTINUE TO
VEER THROUGH TONIGHT...FROM CURRENT ESE ALL THE WAY TO SSW LATE.
CURRENT BUOY OBS SHOW A MIX OF 5 SEC AND 10 SEC WAVES...WITH THE 10
SEC WAVE DOMINANT DUE TO THE LIGHT WINDS...AND THESE WILL PERSIST
THROUGH THE PERIOD MAINTAINING WAVE HEIGHTS OF 2-3 FT.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 PM MONDAY...MAIN MARINE HEADLINE THIS PERIOD REMAINS
APPROACH AND DECAY OF A COLD FRONTAL SYSTEM OVER THE COASTAL
WATERS DURING THE DAY WEDNESDAY. THIS MAY BRING A BRIEF PERIOD
OF N-NW WINDS WEDNESDAY...PRECEDED BY COASTAL RAINSHOWERS AND
ISOLATED TSTMS TUESDAY NIGHT. A FEW TSTMS MAY IMPACT THE OUTER
WATERS ON WEDNESDAY AS WELL SINCE THE FRONT MAY SLOWLY DISSIPATE
THERE MID-WEEK. SEAS WILL BUILD TO 3-4 FT TUESDAY NIGHT AHEAD OF
THE COLD FRONT IN 15-20 KT SW WINDS...POSSIBLY 5 FT VERY OUTER
PORTION. SEAS SETTLING TO 2-3 FT WED AFTN AND EVENING AS WIND
SPEEDS GO LIGHT.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 3 PM MONDAY...HIGH PRESSURE WILL MOVE FROM THE MIDWEST TO THE
APPALACHIANS THROUGH THE PERIOD. THE HIGH WILL SLOWLY WEAKEN LEAVING
A BENIGN PRESSURE PATTERN BY SATURDAY. FOR THURSDAY AND FRIDAY
WINDS WONT BE OVERWHELMING AND EXPECT A EAST/NORTHEAST DIRECTION IN
A RANGE OF 10-15 KNOTS...MOSTLY HOVERING IN THE LOWER END OF THE
RANGE. SPEEDS DROP TO TEN KNOTS AND BELOW BY SATURDAY. SIGNIFICANT
SEAS WILL BE 1-3 FEET WITH AN EQUAL MIX OF A SHORTER PERIOD WIND
WAVE AND SWELL COMPONENT.
&&
.EQUIPMENT...
AS OF 130 PM MONDAY...POWER TO THE ILM ASOS HAS BEEN LOST DUE TO
A POWER SURGE. A REPLACEMENT IS ON ORDER...BUT IT IS LIKELY THAT
ILM ASOS WILL BE WITHOUT AUTOMATED OBSERVATIONS THROUGH TODAY AND
PART OF TUESDAY. THE ILM TOWER SHOULD AMEND OBSERVATIONS UNTIL 11
PM TONIGHT...AND RESUME EARLY TUESDAY MORNING. OVERNIGHT OBS MAY
WILL BE MISSING FOR ALL PARAMETERS. AMD NOT SKED HAS BEEN APPENDED
TO THE ILM TAF AND WILL REMAIN AS SUCH UNTIL POWER IS RESTORED TO
THE SITE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...JDW
SHORT TERM...MBB
LONG TERM...SHK
AVIATION...JDW/DL
MARINE...JDW/MJC/SHK
EQUIPMENT...JDW
AREA FORECAST DISCUSSION
NWS RALEIGH NC
252 PM EDT MON AUG 10 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY...
AND PUSH SOUTHEAST THROUGH THE AREA LATE TUESDAY THROUGH TUESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 250 PM MONDAY...
THE MAIN FRONT WILL SHIFT OFFSHORE ON WEDNESDAY...WITH GENERAL UPPER
LEVEL TROUGHINESS LINGERING OVER THE CAROLINAS THROUGH MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT AND
REMAIN OVERHEAD THROUGH MONDAY. WITH THAT IN MIND...MOST OF THE
EXTENDED PERIOD WILL REMAIN DRY...WITH JUST A SLIGHT CHANCE FOR
SHOWERS OVER THE WESTERN HALF OF THE STATE OVER THE WEEKEND.
TEMPERATURES DURING THE PERIOD WILL FEATURE HIGHS IN THE MID 80S TO
AROUND 90 DEGREES WITH OVERNIGHT LOWS GENERALLY IN THE MID 60S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...
AVIATION CONDITIONS WILL BE SUB-VFR FOR THE MAJORITY OF THE NEXT 24
HOURS AT INT/GSO... HOWEVER AT RDU/FAY/RWI... THE SUB-VFR CONDITIONS
WILL BE MORE SPORADIC WITH VFR DOMINATING AT LEAST THROUGH THIS
EVENING. A MOIST SOUTHWESTERLY SURFACE FLOW INTO NC AHEAD OF AN
APPROACHING COLD FRONT... COMBINED WITH LEFTOVER CLOUD COVER FROM
STORM COMPLEXES TO THE WEST AND NORTHWEST OF NC... WILL KEEP MOSTLY
CLOUDY SKIES AT ALL CENTRAL NC TERMINALS THROUGH TUE. CURRENT MVFR
CIGS AT INT/GSO ARE EXPECTED TO LIFT BRIEFLY TO MAINLY VFR AFTER 21-
22Z TODAY... BUT THEN DROP BACK DOWN TO VFR AND POTENTIALLY IFR
STARTING MID EVENING WITH NUMEROUS SHOWERS AND A FEW STORMS MOVING
IN MAINLY AFTER 01Z... LASTING WELL INTO THE OVERNIGHT HOURS WITH
PERIODIC MVFR VSBYS. MVFR CIGS AND PATCHY SHOWERS ARE LIKELY TO HOLD
AT INT/GSO THROUGH THE END OF THE TAF VALID PERIOD... WITH PATCHY
SHOWERS GIVING WAY TO MORE ORGANIZED THUNDERSTORMS TOWARD THE VERY
END OF THE TAF VALID PERIOD (18Z TUE). RDU/FAY/RWI COULD SEE A
PERIOD OF MVFR CIGS/VSBYS THROUGH THIS EVENING... BUT THE
PROBABILITIES ARE LOW (HIGHER AT RDU THAN AT FAY/RWI BUT STILL LOW).
AFTER 04Z... PATCHY SHOWERS ARE EXPECTED TO SHIFT EASTWARD NEARING
THESE TAF SITES... AND THEY MAY GENERATE A PERIOD OF MVFR OR BRIEFLY
IFR CIGS AND/OR MVFR VSBYS. SIMILAR TO INT/GSO... THE PATCHY MORNING
SHOWERS MAY GIVE WAY TO SCATTERED STORMS IN THE AFTERNOON.
LOOKING BEYOND 18Z TUE... SUB-VFR AND RAINY/STORMY CONDITIONS WILL
DOMINATE AT ALL SITES THROUGH MUCH OF TUE AFTERNOON AND EVENING...
WITH WINDS HOLDING FROM THE SW AT 9-15 KTS. AS THE FRONT PUSHES SE
THROUGH THE AREA WITH HIGH PRESSURE BUILDING IN... WE`LL SEE A NW-TO-
SE CLEARING TREND TO VFR CONDITIONS... WHICH WILL LAST INTO SAT
WITH LARGELY DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...RAH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
145 PM EDT MON AUG 10 2015
.SYNOPSIS...A MOIST SOUTHWEST FLOW WILL HOLD OVER THE REGION THROUGH
TONIGHT. A COLD FRONT WILL APPROACH FROM THE NORTHWEST TUESDAY...
AND PUSH SOUTHEAST THROUGH THE AREA LATE TUESDAY THROUGH TUESDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 255 AM MONDAY...
WEDNESDAY THROUGH FRIDAY... UPPER AIR PATTERN WILL BE DOMINATED BY A
STRONG...AMPLIFIED RIDGE ALONG THE SPINE OF THE ROCKIES...AND A L/W
TROUGH ALONG THE EASTERN SEABOARD. THIS TROUGH IS AT ITS MOST
AMPLIFIED/DEEPEST AT MID WEEK THEN WEAKENS/BROADENS BY THE END OF
THE WEEK. THIS SET-UP WILL SPREAD A DRIER STABLE AIR MASS INTO
CENTRAL NC ON WEDNESDAY WHICH SHOULD LINGER THROUGH THE REMAINDER OF
THE WORK WEEK AS AN AREA OF HIGH PRESSURE AT THE SURFACE BUILDS INTO
THEN SETTLES OVERHEAD BY FRIDAY. ASIDE FROM A SLIGHT CHANCE OF A
SHOWER EARLY WEDNESDAY OVER THE SE COUNTIES AS A COLD FRONT EXITS
THE REGION...EXPECT DRY WEATHER WEDNESDAY THROUGH FRIDAY...AND
TEMPERATURES AVERAGING FAIRLY CLOSE TO NORMAL FOR MID AUGUST. ONE
THING THAT WILL BE LACKING WILL BE THE TYPICAL LATE SUMMER HUMIDITY
AS AFTERNOON DEWPOINTS WILL DROP INTO THE 50S-LOWER 60S EACH
AFTERNOON...ESPECIALLY ON THURSDAY AND FRIDAY. THIS WILL LEAD TO
FAIRLY COMFORTABLE CONDITIONS FOR MID-AUGUST.
FOR SATURDAY THROUGH SUNDAY...THE UPPER RIDGE BECOMES ORIENTATED SW-
NE FROM THE DESERT SW INTO THE GREAT LAKES WHILE THE L/W TROUGH
MAINTAINS A PRESENCE ALONG THE EASTERN SEABOARD. THE SFC HIGH
WEAKENS WITH TIME BUT CONTINUES TO INFLUENCE THE SENSIBLE WEATHER
OVER CENTRAL NC AS THE LOW LEVEL FLOW WILL MAINTAIN A FAIRLY MILD
AIR MASS FOR THIS TIME OF YEAR. ENOUGH MOISTURE MAY CREEP BACK INTO
SECTIONS OF OUR COASTAL PLAIN AND SANDHILL COUNTIES BY SUNDAY TO
SPARK AN ISOLATED SHOWER OR STORM IN THE AFTERNOON. THE ATMOSPHERE
WILL UNDERGO SLIGHT MODIFICATION...LEADING TO TEMPS SLIGHTLY ABOVE
NORMAL BY SUNDAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 145 PM MONDAY...
AVIATION CONDITIONS WILL BE SUB-VFR FOR THE MAJORITY OF THE NEXT 24
HOURS AT INT/GSO... HOWEVER AT RDU/FAY/RWI... THE SUB-VFR CONDITIONS
WILL BE MORE SPORADIC WITH VFR DOMINATING AT LEAST THROUGH THIS
EVENING. A MOIST SOUTHWESTERLY SURFACE FLOW INTO NC AHEAD OF AN
APPROACHING COLD FRONT... COMBINED WITH LEFTOVER CLOUD COVER FROM
STORM COMPLEXES TO THE WEST AND NORTHWEST OF NC... WILL KEEP MOSTLY
CLOUDY SKIES AT ALL CENTRAL NC TERMINALS THROUGH TUE. CURRENT MVFR
CIGS AT INT/GSO ARE EXPECTED TO LIFT BRIEFLY TO MAINLY VFR AFTER 21-
22Z TODAY... BUT THEN DROP BACK DOWN TO VFR AND POTENTIALLY IFR
STARTING MID EVENING WITH NUMEROUS SHOWERS AND A FEW STORMS MOVING
IN MAINLY AFTER 01Z... LASTING WELL INTO THE OVERNIGHT HOURS WITH
PERIODIC MVFR VSBYS. MVFR CIGS AND PATCHY SHOWERS ARE LIKELY TO HOLD
AT INT/GSO THROUGH THE END OF THE TAF VALID PERIOD... WITH PATCHY
SHOWERS GIVING WAY TO MORE ORGANIZED THUNDERSTORMS TOWARD THE VERY
END OF THE TAF VALID PERIOD (18Z TUE). RDU/FAY/RWI COULD SEE A
PERIOD OF MVFR CIGS/VSBYS THROUGH THIS EVENING... BUT THE
PROBABILITIES ARE LOW (HIGHER AT RDU THAN AT FAY/RWI BUT STILL LOW).
AFTER 04Z... PATCHY SHOWERS ARE EXPECTED TO SHIFT EASTWARD NEARING
THESE TAF SITES... AND THEY MAY GENERATE A PERIOD OF MVFR OR BRIEFLY
IFR CIGS AND/OR MVFR VSBYS. SIMILAR TO INT/GSO... THE PATCHY MORNING
SHOWERS MAY GIVE WAY TO SCATTERED STORMS IN THE AFTERNOON.
LOOKING BEYOND 18Z TUE... SUB-VFR AND RAINY/STORMY CONDITIONS WILL
DOMINATE AT ALL SITES THROUGH MUCH OF TUE AFTERNOON AND EVENING...
WITH WINDS HOLDING FROM THE SW AT 9-15 KTS. AS THE FRONT PUSHES SE
THROUGH THE AREA WITH HIGH PRESSURE BUILDING IN... WE`LL SEE A NW-TO-
SE CLEARING TREND TO VFR CONDITIONS... WHICH WILL LAST INTO SAT
WITH LARGELY DRY WEATHER. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...WSS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1020 AM EDT MON AUG 10 2015
.SYNOPSIS...A WARM FRONT TO OUR SOUTHWEST THIS MORNING WILL LIFT
NORTH ACROSS THE AREA TODAY. A COLD FRONT WILL SWEEP THROUGH THE
REGION TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD INTO THE
AREA ON WEDNESDAY AND PERSIST THROUGH THE REMAINDER OF THE WORK
WEEK.
&&
.NEAR TERM /TODAY AND TONIGHT/...
AS OF 1020 AM MONDAY...
CURRENT FORECAST IS IN GOOD SHAPE. MAIN CHANGES WERE TO EXPAND IN
TIME AND AREA THE BAND OF PATCHY SHOWERS CURRENTLY TRACKING THROUGH
THE CWA... DRIVEN BY WEAK MOIST ISENTROPIC UPGLIDE IN THE LOW LEVELS
AND A WEAK MID LEVEL WAVE... AND TO DELAY AFTERNOON CONVECTION IN
THE WEST. HIGH-PW AIR (1.8-2.0") PERSISTS OVER CENTRAL NC WITH
CONSIDERABLE MID AND HIGH DEBRIS CLOUDINESS FROM UPSTREAM MCS ACTION
OVERSPREADING THE AREA FROM THE NW... AND THIS SHOULD SOMEWHAT CURB
THE POTENTIAL FOR INSTABILITY THIS AFTERNOON. EXTRAPOLATION WOULD
FAVOR ANY MCVS GENERATED BY LAST NIGHT`S THE CONVECTIVE COMPLEXES
ACROSS SRN KS/MO/IL INTO WRN KY/TN LIKELY TRACKING WELL TO OUR SW...
AND THIS TREND IS INDICATED BY THE NSSL WRF AND NCAR ENSEMBLE
NEIGHBORHOOD PROBABILITIES. THESE MODEL PACKAGES ALSO SUGGEST THAT
THE CHANCE FOR DEEP CONVECTION EAST OF HIGHWAY 1 THIS AFTERNOON INTO
TONIGHT IS QUITE LOW... AND THE HRRR ALSO DEPICTS LITTLE TO NO
COVERAGE OVER ALL BUT THE FAR WRN CWA AFTERNOON THROUGH AT LEAST
23Z. AFTER SLOWLY TRENDING THE COVERAGE OF SHOWERS DOWN THIS MORNING
INTO EARLY AFTERNOON AS THEY TREND EASTWARD WITH WANING UPGLIDE...
HAVE REDUCED CONVECTION CHANCES TO SLIGHT OR NIL IN THE EAST THIS
AFTERNOON... AND HAVE CUT BACK COVERAGE IN THE WRN CWA A BIT AS
WELL. GIVEN THE GENERALLY MOSTLY CLOUDY SKIES TODAY... HAVE CUT A
COUPLE OF DEGREES OFF HIGHS... NOW RANGING FROM 84 TO 90. -GIH
EARLIER DISCUSSION AS OF 255 AM: LATEST SURFACE ANALYSIS SHOWS WEAK
HIGH PRESSURE EXTENDING INTO EASTERN VA AND NC. MEANWHILE A WARM
FRONT EXTENDING FROM NEAR NASHVILLE TN SOUTHEAST TO NEAR SAVANNAH GA
WAS BEGINNING TO SLOWLY LIFT NORTHWARD...LIKELY LIFTING THROUGH
CENTRAL NC THIS AFTERNOON AND EVENING. FURTHER ALOFT...A RATHER WEAK
DIFFLUENT NORTHWEST FLOW ALOFT WAS EXPECTED TO STRENGTHEN AND
GRADUALLY BACK AND BECOME SOUTHWESTERLY BY LATE TONIGHT AS AN UPPER
TROUGH DROPS INTO THE GREAT LAKES REGION.
REGIONAL RADAR IMAGERY SHOWS SCT SHOWERS SLOWLY DEVELOPING AND
EXPANDING ACROSS THE YADKIN VALLEY AND THE WESTERN PIEDMONT OF
VA/NC/SC. THIS PRECIPITATION APPEARS TO BE ASSOCIATED WITH SOME
ISENTROPIC UPGLIDE NEAR THE 305K SURFACE ENHANCED BY A WEAK SHORT
WAVE ALOFT AND REMNANTS OF AN UPSTREAM MCS. NWP GUIDANCE SUGGESTS
THAT THESE SHOWERS MAY BECOME MORE NUMEROUS AS THEY MOVE INTO THE
WESTERN PIEDMONT TOWARD DAYBREAK. THE PRECIPITATION SHOULD BEGIN TO
DIMINISH LATE THIS MORNING BEFORE REACHING THE COASTAL PLAIN.
MUCH OF THE DAY TODAY SHOULD FEATURE A FAIR AMOUNT OF CLOUDINESS BUT
MAINLY DRY CONDITIONS ACROSS CENTRAL NC. WITH LITTLE FORCING FOR
ASCENT AND WITH ONLY WEAK INSTABILITY PRESENT THIS AFTERNOON AND
FAIRLY MEAGER MID LEVEL LAPSE RATES...CONVECTIVE COVERAGE SHOULD BE
RATHER LIMITED. THE ENVIRONMENT FOR CONVECTION BECOMES A LITTLE BIT
MORE FAVORABLE THIS EVENING AND OVERNIGHT ACROSS THE WESTERN
PIEDMONT AND TRIAD AREA AS LARGER SCALE FORCING APPROACHES AND MID
LEVEL LAPSE RATE ACCORDINGLY INCREASE. STILL...CONVECTION ALLOWING
MODELS HAVE TRENDED NOTICEABLY LESS ACTIVE FOR THIS AFTERNOON AND
TONIGHT WITH NOCTURNAL CONVECTION NOW APPEARING MORE FOCUSED ACROSS
VA/WV. HIGHS TODAY WILL BE COMPLICATED BY THE AMOUNT OF SUNSHINE AND
WITH A TREND TOWARD LESS PRECIPITATION AND PERHAPS THINNER CLOUDS
HAVE ADJUSTED MAXES UP EVER-SO-SLIGHTLY...HIGHS SHOULD RANGE SHOULD
RANGE FROM 84 TO 91. LOWS TONIGHT WILL BE MODERATED BY A GOOD DEAL
OF CLOUD COVER...LOWS SHOULD RANGE BETWEEN 69 AND 74 DEGREES. -BLAES
&&
.SHORT TERM /TUESDAY AND TUESDAY NIGHT/...
AS OF 320 AM MONDAY...
A STRENGTHENING UPPER TROUGH WILL MOVE ACROSS THE GREAT LAKES AND
NORTHEAST DURING THE PERIOD WITH THE MAIN TROUGH AXIS SHIFTING
ACROSS CENTRAL NC TOWARD DAYBREAK WEDNESDAY. THE ASSOCIATED COLD
FRONT WILL MOVE ACROSS THE APPALACHIANS TUESDAY AFTERNOON AND
THROUGH CENTRAL NC TUESDAY NIGHT...REACHING THE COAST TOWARD
WEDNESDAY MORNING.
SCATTERED CONVECTION IS EXPECTED AHEAD OF THE FRONT TUESDAY MORNING
AND EARLY AFTERNOON. AS NOTED IN THE PREVIOUS DISCUSSION...THIS MAY
PLAY A ROLE IN SUBSEQUENT CONVECTION TUESDAY AFTERNOON AND EVENING.
WITH THE UPPER TROUGH CONTAINING MULTIPLE VORTICITY CENTERS...EXPECT
SHOWERS AND THUNDERSTORMS TO MOVE ACROSS CENTRAL NC IN MULTIPLE
CLUSTER OR BANDS THROUGHOUT THE AFTERNOON AS OPPOSED TO ONE WELL
ORGANIZED LINE. THE CLOUDS AND PRECIPITATION WITH THESE CLUSTERS
SHOULD RETARD INSTABILITY A BIT. SPC HAS CENTRAL NC OUTLOOKED WITH A
MARGINAL THREAT OF SEVERE STORMS WHICH SEEMS REASONABLE GIVEN THE
STRONGER DEEP LAYER FLOW AND BULK SHEAR VALUES OF 20-25 KTS
SUGGESTING SOME STORM ORGANIZATION POSSIBLE. CAPE VALUES SHOULD
RANGE FROM WEAK TO LOW END MODERATE WITH MLCAPE VALUES CLIMBING TO
THE 750-1250 J/KG RANGE. THIS ENVIRONMENT WOULD SUPPORT A
MULTICELLULAR/LINE SEGMENT CONVECTIVE MODE WITH A FEW STRONG STORMS
AND POSSIBLY A SEVERE THUNDERSTORMS WITH DAMAGING WINDS THE MOST
LIKELY THREAT. WITH A LINGERING SHORT WAVE TROUGH LIKELY TO MOVE
ACROSS CENTRAL NC LATE TUESDAY EVENING...ANOTHER ROUND OF STORMS IS
POSSIBLE WITH THIS FEATURE AND THE ASSOCIATED COLD FRONT. THE FRONT
SHOULD EXIT THE RAH CWA BETWEEN 06-12Z AND BRING THE PRECIPITATION
TO AN END. HIGHS IN THE 86 TO 91 RANGE WITH LOWS TUESDAY NIGHT IN
THE 65 TO 73 RANGE. -BLAES
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 255 AM MONDAY...
WEDNESDAY THROUGH FRIDAY... UPPER AIR PATTERN WILL BE DOMINATED BY A
STRONG...AMPLIFIED RIDGE ALONG THE SPINE OF THE ROCKIES...AND A L/W
TROUGH ALONG THE EASTERN SEABOARD. THIS TROUGH IS AT ITS MOST
AMPLIFIED/DEEPEST AT MID WEEK THEN WEAKENS/BROADENS BY THE END OF
THE WEEK. THIS SET-UP WILL SPREAD A DRIER STABLE AIR MASS INTO
CENTRAL NC ON WEDNESDAY WHICH SHOULD LINGER THROUGH THE REMAINDER OF
THE WORK WEEK AS AN AREA OF HIGH PRESSURE AT THE SURFACE BUILDS INTO
THEN SETTLES OVERHEAD BY FRIDAY. ASIDE FROM A SLIGHT CHANCE OF A
SHOWER EARLY WEDNESDAY OVER THE SE COUNTIES AS A COLD FRONT EXITS
THE REGION...EXPECT DRY WEATHER WEDNESDAY THROUGH FRIDAY...AND
TEMPERATURES AVERAGING FAIRLY CLOSE TO NORMAL FOR MID AUGUST. ONE
THING THAT WILL BE LACKING WILL BE THE TYPICAL LATE SUMMER HUMIDITY
AS AFTERNOON DEWPOINTS WILL DROP INTO THE 50S-LOWER 60S EACH
AFTERNOON...ESPECIALLY ON THURSDAY AND FRIDAY. THIS WILL LEAD TO
FAIRLY COMFORTABLE CONDITIONS FOR MID-AUGUST.
FOR SATURDAY THROUGH SUNDAY...THE UPPER RIDGE BECOMES ORIENTATED SW-
NE FROM THE DESERT SW INTO THE GREAT LAKES WHILE THE L/W TROUGH
MAINTAINS A PRESENCE ALONG THE EASTERN SEABOARD. THE SFC HIGH
WEAKENS WITH TIME BUT CONTINUES TO INFLUENCE THE SENSIBLE WEATHER
OVER CENTRAL NC AS THE LOW LEVEL FLOW WILL MAINTAIN A FAIRLY MILD
AIR MASS FOR THIS TIME OF YEAR. ENOUGH MOISTURE MAY CREEP BACK INTO
SECTIONS OF OUR COASTAL PLAIN AND SANDHILL COUNTIES BY SUNDAY TO
SPARK AN ISOLATED SHOWER OR STORM IN THE AFTERNOON. THE ATMOSPHERE
WILL UNDERGO SLIGHT MODIFICATION...LEADING TO TEMPS SLIGHTLY ABOVE
NORMAL BY SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
VFR CONDITIONS ARE EXPECTED FOR MUCH OF THE TAF PERIOD ALTHOUGH A
STRENGTHENING SOUTHWESTERLY FLOW WILL PROVIDE INCREASING MOISTURE
AND CLOUDS ALONG WITH A CHANCE OF CONVECTION...MAINLY ACROSS THE
WESTERN PIEDMONT.
SCATTERED SHOWERS ACROSS THE WESTERN AND NORTHERN PIEDMONT NEAR THE
KGSO/KINT TERMINALS WILL CONTINUE TO MOVE SOUTH AND EAST THIS
MORNING BUT GRADUALLY WEAKEN AS THEY APPROACH THE NORTHEAST PIEDMONT
INCLUDING KRDU TERMINAL. THESE SHOWERS MAY PRODUCE A BRIEF MVFR
CIG/VSBY RESTRICTION. OTHERWISE...VFR CONDITIONS WITH LAYERS OF MID
AND HIGH CLOUDS ARE EXPECTED THIS MORNING ALONG WITH A SOUTH WIND
AROUND 10KTS OR LESS.
INCREASING AND LOWERING VFR CLOUDS ARE EXPECTED THIS AFTERNOON AND
EVENING WITH CEILINGS GENERALLY RANGING BETWEEN 4-10KFT. WINDS WILL
STRENGTHEN FROM THE SOUTH AND SOUTHWEST AFTER A WARM FRONT MOVES
THROUGH THE AREA WITH GUSTS UP TO 16KTS AT TIMES AT THE
KINT/KGSO/KRDU TERMINALS. WHILE AN ISOLATED SHOWER CANT BE RULED OUT
DURING THE LATE MORNING INTO THE MID AFTERNOON HOURS THE COVERAGE
SHOULD BE LIMITED ENOUGH TO EXCLUDE FROM THE TAFS. DURING THE LATE
AFTERNOON...SCT THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS WESTERN
NC AND THEN MOVE EAST IMPACTING THE KINT/KGSO/KRDU TERMINALS BETWEEN
20-02Z WITH MVFR VSBY AND CIG RESTRICTIONS. THESE STORMS WILL PUSH
EAST POTENTIALLY REACHING KFAY/KRWI TOWARD MIDNIGHT. GUIDANCE ALSO
SUGGESTS THAT A LAYER OF IFR/MVFR STRATUS MAY DEVELOP TOWARD
DAYBREAK AT THE KFAY/KRWI TERMINALS.
LOOKING BEYOND 06Z TUE...THUNDERSTORMS WILL LIKELY PUSH EAST MONDAY
NIGHT AND WEAKEN WITH A PERIOD OF ADVERSE AVIATION CONDITIONS
POSSIBLE. ANOTHER PERIOD OF SHOWERS/THUNDERSTORMS WITH ADVERSE
AVIATION CONDITIONS APPEARS TO BE A GOOD BET TUESDAY AND TUESDAY
NIGHT AS A COLD FRONT MOVES THROUGH THE AREA. FAIR WEATHER WITH
MAINLY VFR CONDITIONS ARE EXPECTED FROM WEDNESDAY INTO FRIDAY AS
HIGH PRESSURE BUILDS INTO THE REGION. -BLAES
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BLAES
NEAR TERM...HARTFIELD/BLAES
SHORT TERM...BLAES
LONG TERM...WSS
AVIATION...BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 927 PM CDT TUE AUG 11 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS VERY ISOLATED
CELLS ACROSS EASTERN MONTANA MAY LIKELY QUICKLY FADE AND NOT CROSS
THE BORDER INTO NORTH DAKOTA AS THE BOUNDARY LAYER DECOUPLES. THE
00-01 UTC HRRR RUNS SUGGEST A POTENTIAL FOR THUNDERSTORMS LATE
TONIGHT FAR NORTH NEAR THE INTERNATIONAL BORDER IN ASSOCIATION
WITH A WEAK IMPULSE ACROSS NORTHEAST MONTANA AS OF 0230 UTC AND
THE DEVELOPMENT OF A MODEST LOW LEVEL JET. HOWEVER...THIS SCENARIO
DOES CARRY PLENTY OF UNCERTAINTY.
UPDATE ISSUED AT 642 PM CDT TUE AUG 11 2015
AS OF 2345 UTC...ISOLATED CONVECTION ACROSS EASTERN MONTANA HAS
BEEN SLOW TO DEVELOP AND MAINTAIN ITSELF. THE 20-22 UTC HRRR RUNS
HAVE CONTINUED TO OVER DEVELOP CONVECTION THUS FAR AND WILL
DISCOUNT THEIR SOLUTIONS. WILL STILL MAINTAIN AN ISOLATED MENTION
OF THUNDERSTORMS THROUGH SUNSET GENERALLY ALONG AND WEST OF
HIGHWAY 85 AHEAD OF THE UPPER LEVEL IMPULSE ACROSS SOUTHEAST
MONTANA. ANY STORM THAT ENTERS THE STATE COULD POSE A SEVERE WIND
THREAT WITH HIGH STORM BASES. HOWEVER THE THREAT WILL BE ISOLATED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES THIS AFTERNOON/EVENING AND AGAIN WEDNESDAY
AFTERNOON/EVENING.
LATEST SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS WESTERN AND
CENTRAL NORTH DAKOTA...BUT A SHORTWAVE IS INDICATED OVER NORTHWEST
WYOMING/SOUTH CENTRAL MONTANA. THIS SHORTWAVE WILL TRACK OVER THE
TOP OF AN UPPER LEVEL RIDGE THAT EXTENDS FROM THE DESERT SOUTHWEST
INTO EASTERN MONTANA. THE FORCING FROM THIS WAVE/COMBINED WITH
DAYTIME SURFACE HEATING SHOULD BE ENOUGH TO PRODUCE SOME ISOLATED
CONVECTION OVER EASTERN MONTANA LATE THIS AFTERNOON...POSSIBLY
TRACKING INTO WESTERN NORTH DAKOTA THIS EVENING. WITH A BUILDING
UPPER RIDGE...CAPPING WILL BE A LIMITING FACTOR. BUT IF STORMS DO
FORM WE COULD SEE A STRONG OR POSSIBLY SEVERE STORM DUE TO THE
INSTABILITY. WITH THE EXPECTED LIMITED COVERAGE...WILL NOT MENTION
SEVERE WORDING IN THE WEST THIS EVENING.
THE AFOREMENTIONED WAVE...AND A NORTHERN STREAM WAVE WILL KEEP A
CHANCE OF THUNDERSTORMS MAINLY ACROSS SOUTHERN CANADA AND INTO THE
NORTHERN GREAT LAKES REGION LATE TONIGHT AND WEDNESDAY. WE COULD
SEE A STORM OR TWO AS FAR SOUTH AS THE NORTHERN FORECAST AREA
DURING THIS PERIOD...BUT FOR NOW WILL STICK WITH A DRY FORECAST
LATE TONIGHT AND WEDNESDAY. WEDNESDAY IS EXPECTED TO BE EVEN
HOTTER THAN TODAY WITH HIGHS IN THE MID TO UPPER 90S ACROSS MOST
OF WEST AND CENTRAL NORTH DAKOTA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN CONCERNS IN THE LONG TERM INCLUDE VERY WARM CONDITIONS
ASSOCIATED WITH A LARGE UPPER LEVEL RIDGE OVER THE CENTRAL
US...BRINGING FORECAST HIGH TEMPERATURES IN THE 90S WEDNESDAY
THROUGH FRIDAY. ON WEDNESDAY A MID-LEVEL THERMAL CAP SHOULD BE IN
PLACE ACROSS THE DAKOTAS. A LOW LEVEL JET WILL BE IN PLACE WITH
PLENTY OF LOW LEVEL MOISTURE WITH DEWPOINTS IN THE 60S. AN UPPER
LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH THE RIDGE ACROSS MONTANA
AND WYOMING ON WEDNESDAY...APPROACHING THE DAKOTAS WEDNESDAY NIGHT.
A WEAK SURFACE TROUGH IS FORECAST TO DEVELOP SOUTHWEST TO NORTHEAST
ACROSS THE STATE AS WELL. THIS MAY PROVIDE ENOUGH INSTABILITY TO
OVERCOME A MID-LEVEL CAP...ESPECIALLY AFTER SUNSET. HAVE SMALL
CHANCES OF THUNDERSTORMS WEDNESDAY NIGHT - SOME STORMS COULD
BE STRONG...WITH CONVECTION PERHAPS ABLE TO CONTINUE THROUGH
THURSDAY MORNING. THE UPPER LEVEL SHORTWAVE MOVES ACROSS NORTH
DAKOTA ON THURSDAY...WITH THE SURFACE BOUNDARY BECOMING A COLD FRONT
AS IT SAGS SOUTH. THE NAM ALIGNS THE COLD FRONT WEST-TO-EAST ACROSS
SOUTHERN NORTH DAKOTA THURSDAY AFTERNOON. THUS EVEN WITH VERY WARM
AIR AT MID LEVELS...THE CAP MAY BREAK THURSDAY AFTERNOON TO BRING
SCATTERED THUNDERSTORMS TO SOUTHERN NORTH DAKOTA...LINGERING INTO
THURSDAY EVENING. FRIDAY SHOULD BE MAINLY DRY AS THE UPPER LEVEL
RIDGE REMAINS IN PLACE WITH NO OBVIOUS SHORTWAVES OR SURFACE
FEATURES TO BREAK THE STRONG MID-LEVEL CAP.
THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN FRIDAY NIGHT WITH A
STRONG COLD FRONTAL SYSTEM MOVING EAST ACROSS THE NORTHERN PLAINS
THROUGH SATURDAY. CHANCES OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT
THROUGH SATURDAY NIGHT. HIGHS SUNDAY IN THE 70S TO LOWER 80S.
CHANCES OF SHOWERS AND THUNDERSTORMS AGAIN SUNDAY NIGHT THROUGH
TUESDAY NIGHT AS ANOTHER UPPER LEVEL LOW MOVES EAST OUT OF THE
ROCKIES AND ACROSS THE NORTHERN PLAINS. HIGH TEMPERATURES MAINLY IN
THE 70S.
WITH GRASSES CURING AND VERY WARM CONDITIONS THIS WEEK...THIS MAY
SET THE STAGE FOR FUTURE FIRE WEATHER CONCERNS. ALTHOUGH WINDS
SHOULD NOT BE STRONG THIS WEEK...ANY DRY AND WINDY DAYS BEYOND THIS
WEEK MAY POSE FOR HEIGHTENED FIRE WEATHER CONCERNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 927 PM CDT TUE AUG 11 2015
VFR CONDITIONS ARE FORECAST ACROSS WESTERN AND CENTRAL NORTH
DAKOTA FOR THE 00 UTC TAF PERIOD WITH A VERY WARM AIRMASS IN PLACE
FOR WEDNESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
650 PM CDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 642 PM CDT TUE AUG 11 2015
AS OF 2345 UTC...ISOLATED CONVECTION ACROSS EASTERN MONTANA HAS
BEEN SLOW TO DEVELOP AND MAINTAIN ITSELF. THE 20-22 UTC HRRR RUNS
HAVE CONTINUED TO OVER DEVELOP CONVECTION THUS FAR AND WILL
DISCOUNT THEIR SOLUTIONS. WILL STILL MAINTAIN AN ISOLATED MENTION
OF THUNDERSTORMS THROUGH SUNSET GENERALLY ALONG AND WEST OF
HIGHWAY 85 AHEAD OF THE UPPER LEVEL IMPULSE ACROSS SOUTHEAST
MONTANA. ANY STORM THAT ENTERS THE STATE COULD POSE A SEVERE WIND
THREAT WITH HIGH STORM BASES. HOWEVER THE THREAT WILL BE ISOLATED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES THIS AFTERNOON/EVENING AND AGAIN WEDNESDAY
AFTERNOON/EVENING.
LATEST SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS WESTERN AND
CENTRAL NORTH DAKOTA...BUT A SHORTWAVE IS INDICATED OVER NORTHWEST
WYOMING/SOUTH CENTRAL MONTANA. THIS SHORTWAVE WILL TRACK OVER THE
TOP OF AN UPPER LEVEL RIDGE THAT EXTENDS FROM THE DESERT SOUTHWEST
INTO EASTERN MONTANA. THE FORCING FROM THIS WAVE/COMBINED WITH
DAYTIME SURFACE HEATING SHOULD BE ENOUGH TO PRODUCE SOME ISOLATED
CONVECTION OVER EASTERN MONTANA LATE THIS AFTERNOON...POSSIBLY
TRACKING INTO WESTERN NORTH DAKOTA THIS EVENING. WITH A BUILDING
UPPER RIDGE...CAPPING WILL BE A LIMITING FACTOR. BUT IF STORMS DO
FORM WE COULD SEE A STRONG OR POSSIBLY SEVERE STORM DUE TO THE
INSTABILITY. WITH THE EXPECTED LIMITED COVERAGE...WILL NOT MENTION
SEVERE WORDING IN THE WEST THIS EVENING.
THE AFOREMENTIONED WAVE...AND A NORTHERN STREAM WAVE WILL KEEP A
CHANCE OF THUNDERSTORMS MAINLY ACROSS SOUTHERN CANADA AND INTO THE
NORTHERN GREAT LAKES REGION LATE TONIGHT AND WEDNESDAY. WE COULD
SEE A STORM OR TWO AS FAR SOUTH AS THE NORTHERN FORECAST AREA
DURING THIS PERIOD...BUT FOR NOW WILL STICK WITH A DRY FORECAST
LATE TONIGHT AND WEDNESDAY. WEDNESDAY IS EXPECTED TO BE EVEN
HOTTER THAN TODAY WITH HIGHS IN THE MID TO UPPER 90S ACROSS MOST
OF WEST AND CENTRAL NORTH DAKOTA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN CONCERNS IN THE LONG TERM INCLUDE VERY WARM CONDITIONS
ASSOCIATED WITH A LARGE UPPER LEVEL RIDGE OVER THE CENTRAL
US...BRINGING FORECAST HIGH TEMPERATURES IN THE 90S WEDNESDAY
THROUGH FRIDAY. ON WEDNESDAY A MID-LEVEL THERMAL CAP SHOULD BE IN
PLACE ACROSS THE DAKOTAS. A LOW LEVEL JET WILL BE IN PLACE WITH
PLENTY OF LOW LEVEL MOISTURE WITH DEWPOINTS IN THE 60S. AN UPPER
LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH THE RIDGE ACROSS MONTANA
AND WYOMING ON WEDNESDAY...APPROACHING THE DAKOTAS WEDNESDAY NIGHT.
A WEAK SURFACE TROUGH IS FORECAST TO DEVELOP SOUTHWEST TO NORTHEAST
ACROSS THE STATE AS WELL. THIS MAY PROVIDE ENOUGH INSTABILITY TO
OVERCOME A MID-LEVEL CAP...ESPECIALLY AFTER SUNSET. HAVE SMALL
CHANCES OF THUNDERSTORMS WEDNESDAY NIGHT - SOME STORMS COULD
BE STRONG...WITH CONVECTION PERHAPS ABLE TO CONTINUE THROUGH
THURSDAY MORNING. THE UPPER LEVEL SHORTWAVE MOVES ACROSS NORTH
DAKOTA ON THURSDAY...WITH THE SURFACE BOUNDARY BECOMING A COLD FRONT
AS IT SAGS SOUTH. THE NAM ALIGNS THE COLD FRONT WEST-TO-EAST ACROSS
SOUTHERN NORTH DAKOTA THURSDAY AFTERNOON. THUS EVEN WITH VERY WARM
AIR AT MID LEVELS...THE CAP MAY BREAK THURSDAY AFTERNOON TO BRING
SCATTERED THUNDERSTORMS TO SOUTHERN NORTH DAKOTA...LINGERING INTO
THURSDAY EVENING. FRIDAY SHOULD BE MAINLY DRY AS THE UPPER LEVEL
RIDGE REMAINS IN PLACE WITH NO OBVIOUS SHORTWAVES OR SURFACE
FEATURES TO BREAK THE STRONG MID-LEVEL CAP.
THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN FRIDAY NIGHT WITH A
STRONG COLD FRONTAL SYSTEM MOVING EAST ACROSS THE NORTHERN PLAINS
THROUGH SATURDAY. CHANCES OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT
THROUGH SATURDAY NIGHT. HIGHS SUNDAY IN THE 70S TO LOWER 80S.
CHANCES OF SHOWERS AND THUNDERSTORMS AGAIN SUNDAY NIGHT THROUGH
TUESDAY NIGHT AS ANOTHER UPPER LEVEL LOW MOVES EAST OUT OF THE
ROCKIES AND ACROSS THE NORTHERN PLAINS. HIGH TEMPERATURES MAINLY IN
THE 70S.
WITH GRASSES CURING AND VERY WARM CONDITIONS THIS WEEK...THIS MAY
SET THE STAGE FOR FUTURE FIRE WEATHER CONCERNS. ALTHOUGH WINDS
SHOULD NOT BE STRONG THIS WEEK...ANY DRY AND WINDY DAYS BEYOND THIS
WEEK MAY POSE FOR HEIGHTENED FIRE WEATHER CONCERNS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 642 PM CDT TUE AUG 11 2015
OTHER THAN A SMALL POTENTIAL FOR A THUNDERSTORM TO APPROACH
KISN/KDIK THROUGH SUNSET THIS EVENING...VFR CONDITIONS ARE
FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA FOR THE 00 UTC
TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1140 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 1124 AM CDT MON AUG 10 2015
LATEST VISIBLE SATELLITE SHOWING A CUMULUS FIELD INITIATING AS
CONVECTIVE TEMPERATURES HAVE BEEN REACHED. QUESTION BECOMES
WHETHER OR NOT A SHORTWAVE TROUGH SLIDING INTO CENTRAL NORTH
DAKOTA AND THE JAMES RIVER VALLEY THIS AFTERNOON WILL BE ABLE TO
GENERATE AN ISOLATED RAIN SHOWER(S) GIVEN SUCH A SHALLOW LAYER OF
HIGHER RELATIVE HUMIDITIES PER TIME HEIGHT CROSS SECTIONS. THE
HIGH RESOLUTION MODELS MAINTAIN THE IDEA OF ISOLATED CELLS
DEVELOPING WHILE THE NAM/GFS KEEP IT DRY. THE RAP13 PUTS 0.01 ON
THE SOUTH OF THE TURTLE MOUNTAINS AND PUSHES THIS AREA NEAR THE
NORTHERN JAMES RIVER VALLEY. DESPITE THE EXPECTED CUMULUS FIELD
GROWING IN COVERAGE WITH STRENGTHENING LOW LEVEL LAPSE RATES THIS
AFTERNOON...WILL KEEP THE FORECAST DRY. THE CHANCE FOR RECEIVING
MEASURABLE PRECIPIATION AND EXACTLY WHERE REMAINS VERY LOW AT THIS
TIME. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 815 AM CDT MON AUG 10 2015
12Z BISMARCK SKEW-T SHOWS A CONVECTIVE TEMPERATURE OF 77F TODAY
WHICH WILL BE REACHED BETWEEN 16Z-17Z/11AM-NOON CDT. EXPECTING
SOME CUMULUS TO DEVELOP...HOWEVER TIME-HEIGHT CROSS SECTIONS SHOW
LIMITED MOISTURE IN THE 850-700MB LAYER...WITH DRIER AIR ABOVE.
LATEST WATER VAPOR IMAGERY LOOP REVEALS A SHORTWAVE/VORTICITY LOBE
LOCATED IN FAR SOUTHEAST SASKATCHEWAN EXTENDING INTO WESTERN NORTH
DAKOTA. THIS SHORTWAVE IS PICKED UP BY THE GFS AND IS FORECAST TO
REACH THE JAMES RIVER VALLEY 21Z-00Z. 850MB-700MB LAPSE RATES
FORECAST AT 9.5C/KM LATE THIS AFTERNOON IN CENTRAL NORTH DAKOTA.
HI RESOLUTION MODELS HRRR/ARW WEST/NMM WEST INDICATE ISOLATED
SHOWERS BETWEEN BISMARCK AND JAMESTOWN 21Z-00Z. THE PREVIOUS
DISCUSSION MENTIONED THIS POTENTIAL. BUFKIT SOUNDINGS CURRENTLY
MAINTAIN A SHALLOW POCKET OF MOISTURE REMAINING IN PLACE LATE THIS
AFTERNOON WHEN THE MAX OMEGA/VERTICAL MOTION IN THE LOWEST LAYERS
IS REACHED. WITH VERY MINIMAL AREAL COVERAGE AT THIS TIME...WILL
KEEP THINGS DRY AND WATCH THE TRENDS AND ADJUST IF NEEDED LATER
THIS MORNING. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1124 AM CDT MON AUG 10 2015
VFR CIGS/VSBYS NEXT 24HR...WITH LIGHT WINDS. A SCT CUMULUS FIELD
WILL GROW THROUGH MONDAY AFTERNOON WITH BKN CIGS AT 5000FT
EXPECTED AT KJMS. THE RISK FOR ANY SHOWERS AT KBIS OR KJMS REMAIN
TOO LOW FOR ANY MENTION AT THIS TIME. THE CUMULUS WILL DISSIPATE
AFTER SUNSET WITH A CLEAR SKY TO FOLLOW FOR THE REMAINDER OF THE
TAF PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CK
LONG TERM...JNS
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
834 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 815 AM CDT MON AUG 10 2015
12Z BISMARCK SKEW-T SHOWS A CONVECTIVE TEMPERATURE OF 77F TODAY
WHICH WILL BE REACHED BETWEEN 16Z-17Z/11AM-NOON CDT. EXPECTING
SOME CUMULUS TO DEVELOP...HOWEVER TIME-HEIGHT CROSS SECTIONS SHOW
LIMITED MOISTURE IN THE 850-700MB LAYER...WITH DRIER AIR ABOVE.
LATEST WATER VAPOR IMAGERY LOOP REVEALS A SHORTWAVE/VORTICITY LOBE
LOCATED IN FAR SOUTHEAST SASKATCHEWAN EXTENDING INTO WESTERN NORTH
DAKOTA. THIS SHORTWAVE IS PICKED UP BY THE GFS AND IS FORECAST TO
REACH THE JAMES RIVER VALLEY 21Z-00Z. 850MB-700MB LAPSE RATES
FORECAST AT 9.5C/KM LATE THIS AFTERNOON IN CENTRAL NORTH DAKOTA.
HI RESOLUTION MODELS HRRR/ARW WEST/NMM WEST INDICATE ISOLATED
SHOWERS BETWEEN BISMARCK AND JAMESTOWN 21Z-00Z. THE PREVIOUS
DISCUSSION MENTIONED THIS POTENTIAL. BUFKIT SOUNDINGS CURRENTLY
MAINTAIN A SHALLOW POCKET OF MOISTURE REMAINING IN PLACE LATE THIS
AFTERNOON WHEN THE MAX OMEGA/VERTICAL MOTION IN THE LOWEST LAYERS
IS REACHED. WITH VERY MINIMAL AREAL COVERAGE AT THIS TIME...WILL
KEEP THINGS DRY AND WATCH THE TRENDS AND ADJUST IF NEEDED LATER
THIS MORNING. FORECAST REMAINS ON TRACK.
UPDATE ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CDT MON AUG 10 2015
EXPECT VFR CONDITIONS TO DOMINATE FOR THE 12Z TAF PERIOD. VERY
PATCHY FOG HAS DEVELOPED ACROSS PARTS OF CENTRAL INTO NORTHEAST
NORTH DAKOTA...BUT DO NOT EXPECT IT TO PERSIST. WILL MONITOR THE
LATEST OBSERVATIONS AND TRY TO KEEP ANY FOG MENTION TO A MINIMUM.
WINDS SHOULD STAY LESS THAN 10KTS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...CK
LONG TERM...JNS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
542 AM CDT MON AUG 10 2015
.UPDATE...
ISSUED AT 542 AM CDT MON AUG 10 2015
MADE A QUICK UPDATE TO ADD PATCHY FOG FROM HETTINGER...THOUGH
WASHBURN...TO RUGBY AND ROLETTE. OBSERVATIONS THIS MORNING HAVE
FAVORED THAT REGION FOR FOG...AND THIS ALSO LINES UP WITH THE
LATEST ITERATIONS OF THE HRRR AND RAP13. A COUPLE ROGUE SHOWERS
DEVELOPED OVERNIGHT IN PARTS OF LOGAN AND MCINTOSH COUNTIES...BUT
THOSE HAVE DISSIPATED. THE REMAINDER OF THE FORECAST IS ON TRACK
AND ONLY ADJUSTED TO CAPTURE THE LATEST OBSERVATIONS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 314 AM CDT MON AUG 10 2015
A QUIET START TO THE DAY IS EXPECTED WITH HIGH PRESSURE IN PLACE
AT THE SURFACE ACROSS THE NORTHERN PLAINS. WILL HAVE TO MONITOR
VISIBILITIES OVER THE NEXT FEW HOURS WITH LOW TEMPERATURE /
DEWPOINT SPREADS...OTHERWISE SKIES WILL BE MOSTLY SUNNY EARLY THIS
MORNING.
A POTENTIAL CONCERN FOR TODAY IS THE CHANCE FOR AN ISOLATED SHOWER
OR THUNDERSTORM THIS AFTERNOON. SOME OF THE HI-RES MODEL
SOLUTIONS HAVE HINTED AT THE POSSIBILITY OF AN ISOLATED SHOWER AS
LOW LEVEL LAPSE RATES STEEPEN THIS AFTERNOON. FORECAST SOUNDINGS
SHOW ONLY A SMALL AREA OF INCREASED MOISTURE (RELATIVE HUMIDITY)
THIS AFTERNOON AROUND H85...WITH VERY DRY AIR IN PLACE IN THE LOW
LEVELS. FOR NOW...WILL STAY WITH THE DRY FORECAST AND ONLY SHOW
SOME INCREASE IN CLOUDS AS CUMULUS DEVELOPS THIS AFTERNOON. HIGH
TEMPERATURES TODAY WILL BE IN THE 80S.
TONIGHT WILL SEE CLEARING SKIES AS THE CUMULUS DISSIPATES DURING
THE EVENING. LOWS SHOULD GENERALLY BE IN THE MID 50S TO NEAR 60.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 314 AM CDT MON AUG 10 2015
DETERMINISTIC MODELS AND ENSEMBLE OUTPUT CONTINUE TO INDICATE
STRONG UPPER LEVEL RIDGE BUILDING ACROSS WESTERN NORTH AMERICA AND
SLOWLY MOVING ACROSS THE NORTHERN PLAINS BY LATE WEEK AS DEEP
UPPER LOW MOVES INTO THE PAC NW BY THU/FRI. HIGH TEMPS ACROSS
WESTERN AND CENTRAL ND WILL REACH MID/UPPER 90S BY WEDNESDAY AND
THURSDAY WITH THE HIGHEST TEMPS ACROSS THE WEST. TEMPS WILL REMAIN
ABOVE NORMAL...BUT SLIGHTLY LOWER BY FRI AND SAT AS UPPER LEVEL
RIDGE AXIS SLOWLY PUSHES EAST OF US. MODELS GENERATE SOME
CONVECTIVE PRECIP TUE NIGHT AND WED WITH GFS INDICATING SOME
ELEVATED INSTABILITY AND A LOW LEVEL JET STRENGTHENING TUE NIGHT
AND UP TO 2000 J/KG OF SURFACE BASED CAPE ON WEDNESDAY. PROXIMITY
OF UPPER LEVEL RIDGE AND GENERAL ANTICYCLONIC FLOW WILL LIMIT
CONVECTIVE POTENTIAL...BUT AN ISOLATED SHOWER OR THUNDERSTORM IS
NOT OUT OF THE QUESTION WITH MODELS SHOWING A FEW WEAK SHORTWAVE
TROUGHS RIDING OVER THE RIDGE. BETTER CHANCE FOR PRECIP WILL BEGIN
FRIDAY EVENING AS COLD FRONT MOVES THROUGH THE REGION ON SATURDAY
PER GFS/ECMWF.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CDT MON AUG 10 2015
EXPECT VFR CONDITIONS TO DOMINATE FOR THE 12Z TAF PERIOD. VERY
PATCHY FOG HAS DEVELOPED ACROSS PARTS OF CENTRAL INTO NORTHEAST
NORTH DAKOTA...BUT DO NOT EXPECT IT TO PERSIST. WILL MONITOR THE
LATEST OBSERVATIONS AND TRY TO KEEP ANY FOG MENTION TO A MINIMUM.
WINDS SHOULD STAY LESS THAN 10KTS THROUGH THE PERIOD.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CK
SHORT TERM...CK
LONG TERM...JNS
AVIATION...CK
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
212 PM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TUESDAY/...
NO REAL CHANGES TO THE FORECAST. TWEAKED POPS A TAD TO ACCOUNT
FOR DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE
EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
UPPER TROUGH ACROSS THE EASTERN U.S. ALONG WITH SEVERAL EMBEDDED
SHORTWAVES...WILL KEEP A MENTION OF SHOWERS AND THUNDERSTORMS IN
THE FORECAST FOR THE SHORT TERM PERIOD. IN ADDITION...SOMEWHAT
COOLER WEATHER WILL BE REALIZED TOO. THE POTENTIAL FOR A MORE
POTENT WAVE IS POSSIBLE WEDNESDAY AFTERNOON...BUT THIS STILL
REMAINS IN QUESTION AS MODELS VARY ON THE HANDLING OF THIS
SITUATION. HIGH PRESSURE THEN NUDGES IN FROM THE WEST THIS
THURSDAY AND FRIDAY...FOR A BRIEF BREAK IN THE WEATHER.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WEEKEND AND BEYOND REMAINS RATHER UNCERTAIN. ANOTHER FRONT WILL
APPROACH OVER THE WEEKEND. GFS TENDS TO BRING THE FRONTAL BOUNDARY
THROUGH THE CWA OVER THE WEEKEND...WITH SHOWERS AND THUNDERSTORMS.
WHILE ECMWF IS A DRIER SOLUN...AND TENDS TO WASH OUT THE FRONT
ACROSS THE NORTHERN PART OF CWA. FOR NOW...WENT AHEAD AND PUT A
SLIGHT CHANCE TO CHANCE POPS ACROSS THE CWA.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
INCREASED THUNDERSTORM COVERAGE OVER MUCH OF THE REGION THIS
AFTERNOON WITH LOCALIZED MVFR AND POSSIBLE IFR IN SHRA/TSRA/CIGS.
COLD FRONT TO PUSH THROUGH OVERNIGHT TONIGHT WITH MVFR/IFR
CIGS/SHRA/TSRA WITH THE FRONT. BEHIND THE FRONT LINGERING MVFR/IFR
SHOWERS/FOG/CIGS TO 12Z TUESDAY AND LINGER PAST 12Z TUESDAY IN THE
WV MOUNTAINS. CONDITIONS IMPROVE TO VFR...MAINLY BETWEEN 15Z- 18Z
TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H M H H H H H
EKN CONSISTENCY H H H H H H M M M M M M
PKB CONSISTENCY H H H H H H M M M M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS
SHORT TERM...SL
LONG TERM...SL
AVIATION...JS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
156 PM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO REAL CHANGES TO THE FORECAST. TWEEKED POPS A TAD TO ACCOUNT FOR
DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
INCREASED THUNDERSTORM COVERAGE OVER MUCH OF THE REGION THIS
AFTERNOON WITH LOCALIZED MVFR AND POSSIBLE IFR IN SHRA/TSRA/CIGS.
COLD FRONT TO PUSH THROUGH OVERNIGHT TONIGHT WITH MVFR/IFR
CIGS/SHRA/TSRA WITH THE FRONT. BEHIND THE FRONT LINGERING MVFR/IFR
SHOWERS/FOG/CIGS TO 12Z TUESDAY AND LINGER PAST 12Z TUESDAY IN THE
WV MOUNTAINS. CONDITIONS IMPROVE TO VFR...MAINLY BETWEEN 15Z- 18Z
TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 18 19 20 21 22 23 00 01 02 03 04 05
EDT 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
CRW CONSISTENCY H H H H H H H H H M M M
HTS CONSISTENCY H H H H H H M M M M M M
BKW CONSISTENCY H H H H H H M H H H H H
EKN CONSISTENCY H H H H H H M M M M M M
PKB CONSISTENCY H H H H H H M M M M M M
CKB CONSISTENCY H H H H H H H H H M M M
AFTER 18Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS/KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...JS
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1108 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
NO REAL CHANGES TO THE FORECAST. TWEEKED POPS A TAD TO ACCOUNT FOR
DEVELOPING CONVECTION. OTHERWISE, NO OTHER CHANGES ARE EXPECTED.
PREVIOUS DISCUSSION...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY
WISE/BEST...NOT TO RUN WITH ANY ONE MODEL SOLUTION. WITH
ADJUSTMENTS BEING MADE DURING THE COURSE OF THE DAY AND EVENING
BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS WILL PREVAIL OUTSIDE OF BRIEF MVFR CONDITIONS IN
CONVECTION THIS AFTERNOON.
INCREASED THUNDERSTORM COVERAGE IN SE OHIO AFTER 20Z...THEN MOVE
INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A FEW STRONG TO SEVERE
CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT BKN TO OVC AND
VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
EDT 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H M M M M M H M M M
BKW CONSISTENCY H H H H M M M M M M H H
EKN CONSISTENCY H H H H M M M M M M M H
PKB CONSISTENCY H H H H H M M M M M M M
CKB CONSISTENCY H H H H H H H H H H M M
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...JS/KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...JS/KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
645 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
DURING THE EVENING INTO WV AND NRN KY . UPDATED THE HWO AT 630 AM...WILL
HIGHLIGHT SOUTHEAST OHIO INTO WRN WV AND NE KENTUCKY FOR POSSIBLE STRONG
TO SEVERE CONVECTION LATE THIS AFTERNOON OR THIS EVENING. WOULD
NOT BE SURPRISED IF SPC UPDATES ON DAY 1...INCLUDED SOME
SLIGHT RISK AREAS...AS THIS WHOLE SYSTEM EVOLVES/DEVELOPS.
OVERALL THOUGH...THE FLOW NOT STRONG AND EL PEAKS ABOUT 35 THSD FT.
ACTUALLY MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
IN THE WAKE OF THE OVERNIGHT MID LEVEL DISTURBANCE AND A FEW LIGHT SHOWERS
OR SPRINKLES...THE MID DECK WAS THINNING AT 10Z...ALLOWING SOME
DENSER VALLEY FOG IN THE WV MOUNTAIN VALLEYS.
THE FOG SHOULD DISSIPATE BY 13Z.
AT 10Z...MAIN CONVECTION COMPLEXES DROPPING SE THROUGH WRN KY AND TN...BUT
A FEW SHOWERS MAY FORM FURTHER E AND AFFECT HTS TRI STATE AND SW VA THIS
MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL CU FORMING TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES.
HOWEVER...LATER IN THE DAY...TRIED TO INCREASE THUNDERSTORM COVERAGE IN SE
OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A
FEW STRONG TO SEVERE CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT
BKN TO OVC AND VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H M M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L M M H H H H H H M M
PKB CONSISTENCY M H H H H H H H H H H M
CKB CONSISTENCY M M H H H H H H H H H H
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
604 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
THIS EVENING INTO WV. HOWEVER...AS OF THIS EARLY HOUR...COULD NOT
HIGHLIGHT A SPECIFIC THREAT AREA. WOULD NOT BE SURPRISED IF SPC
UPDATES ON DAY 1...INCLUDED SOME SLIGHT RISK AREAS...AS THIS WHOLE
SYSTEM EVOLVES/DEVELOPS.
OVERALL NOT TOO EXCITED WITH THE THIN CAPE AND RELATIVELY WEAK FLOW
AS DISCUSSED. MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /10Z MONDAY THROUGH FRIDAY/...
IN THE WAKE OF THE OVERNIGHT MID LEVEL DISTURBANCE AND A FEW LIGHT SHOWERS
OR SPRINKLES...THE MID DECK WAS THINNING AT 10Z...ALLOWING SOME
DENSER VALLEY FOG IN THE WV MOUNTAIN VALLEYS.
THE FOG SHOULD DISSIPATE BY 13Z.
AT 10Z...MAIN CONVECTION COMPLEXES DROPPING SE THROUGH WRN KY AND TN...BUT
A FEW SHOWERS MAY FORM FURTHER E AND AFFECT HTS TRI STATE AND SW VA THIS
MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL CU FORMING TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES.
HOWEVER...LATER IN THE DAY...TRIED TO INCREASE THUNDERSTORM COVERAGE IN SE
OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z TO 06Z. COULD NOT RULE OUT A
FEW STRONG TO SEVERE CELLS. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT
BKN TO OVC AND VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
LINGERING SHOWERS 06Z TO 12Z TUESDAY...CEILINGS COULD LOWER TO NEAR
1 THSD FT NEAR FRONT AND VSBY 3 TO 5 MILES...AND LINGER PAST
12Z TUESDAY IN THE WV MOUNTAINS.
HAVE ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY...THEN NEAR A EKN TO HTS LINE BY 12Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING AND DURATION OF ROUNDS OF
CONVECTION THIS AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 09 10 11 12 13 14 15 16 17 18 19 20
EDT 1HRLY 05 06 07 08 09 10 11 12 13 14 15 16
CRW CONSISTENCY M H H H H H H H H H H H
HTS CONSISTENCY M H H H H H H H H M M M
BKW CONSISTENCY H H H H H H H H H H M M
EKN CONSISTENCY L L M M H H H H H H M M
PKB CONSISTENCY M H H H H H H H H H H M
CKB CONSISTENCY M M H H H H H H H H H H
AFTER 12Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING IFR CEILINGS IN LIGHTER SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
500 AM EDT MON AUG 10 2015
.SYNOPSIS...
MUGGY TODAY. WEAK LOW PRESSURE DEVELOPS IN UPPER OHIO VALLEY MOVES
NORTHEAST TONIGHT...DRAGGING A COLD FRONT THRU LATE TONIGHT AND
TUESDAY MORNING. DRIER WITH COOLER NIGHTS WEDNESDAY INTO THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ONE OF THOSE MUGGY AUGUST DAYS...PROBABLY WISE/BEST...NOT TO RUN WITH ANY
ONE MODEL SOLUTION. WITH ADJUSTMENTS BEING MADE DURING THE COURSE OF
THE DAY AND EVENING BASED ON THE MOST RECENT CONVECTIVE TRENDS.
AT 07Z...ONE MID LEVEL VORT MAX STRETCHED OUT FROM SRN WV NNW TOWARD ZZV.
IT SHOULD EXIT TO OUR EAST 12Z TO 14Z. NOT MUCH VIRGA IN THIS AIRMASS...SO
IT WAS CAUSING SOME DISORGANIZED AREAS OF RW- OR SPRINKLES THIS PREDAWN.
ANOTHER DISTURBANCE DROPPING SE FROM WRN KY TOWARD MIDDLE TENNESSEE.
EVEN THOUGH MAIN CONVECTIVE CLUSTERS WILL DROP INTO TN...FEEL SOME
OF ITS AFFECTS... IN THIS MUGGY AIR...COULD RIPPLE EAST AND CAUSE
SHOWERS TO FORM INTO OUR TRI STATE AND SW VA THIS MORNING. MATTER OF
FACT...THE 00Z NAM HAD THE EQUILIBRIUM LEVEL QUICKLY REACHING TOWARD
35 THSD BY 15Z AT HTS. YET...IT DOES NOT GET ANY HIGHER...THIS
AFTERNOON OR EVENING.
WEAK SURFACE LOW EXPECTED TO FORM IN THE UPPER OHIO VALLEY...SAY
OVER OHIO...THIS AFTERNOON. THE WEAK WIND FLOW DOES
INCREASE...MAYBE SOME 15 KNOTS AT 925 MBS BY 21Z ON THE RAP IN THE
OHIO VALLEY COUNTIES. THE 06Z NAM DEEPENS THIS CIRCULATION EVEN
MORE WITH SOME 25 KNOTS BY 00Z TUESDAY. 700 MB FLOW ONLY INCREASES
TO ABOUT 20 TO 25 KNOTS. EXPECT CELL MOVEMENT THIS AFTERNOON AND
EVENING TO BE ABOUT 25 KNOTS...WHICH IS NOT TOO FAST...AND NOT TOO
SLOW.
WILL BASE FORECAST ON ASSOCIATED TROF/FRONT FORM THE EXITING WEAK
LOW PRESSURE...TO REACH INTO OUR SE OHIO AROUND 06Z TUESDAY...THEN
REACHING BETWEEN CKB AND EKN TO NEAR HTS BY 12Z TUESDAY. TRYING TO
TIME THE PREFRONTAL CONVECTION THAT FORMS IN OHIO THIS
AFTERNOON...AND HOW FAST TO PUSH THE HIGHER POPS EAST... THROUGH
WEST VIRGINIA...IS ONE HEADACHE. TRIED TO HAVE LIKELY POPS LATE
THIS AFTERNOON IN SE OHIO...REACHING OHIO RIVER AT 00Z
TUESDAY...THEN TOWARD EKN TO CRW 03Z TO 06Z TUESDAY. COULD SEE SOME
SEVERE STORM DEVELOPMENT IN THIS HUMID ENVIRONMENT NEAR OUR SE OHIO
COUNTIES IN THE OHIO VALLEY LATE THIS AFTERNOON...THEN MOVE EAST
THIS EVENING INTO WV. HOWEVER...AS OF THIS EARLY HOUR...COULD NOT
HIGHLIGHT A SPECIFIC THREAT AREA. WOULD NOT BE SURPRISED IF SPC
UPDATES ON DAY 1...INCLUDED SOME SLIGHT RISK AREAS...AS THIS WHOLE
SYSTEM EVOLVES/DEVELOPS.
OVERALL NOT TOO EXCITED WITH THE THIN CAPE AND RELATIVELY WEAK FLOW
AS DISCUSSED. MOST COUNTIES...ESPECIALLY ALONG THE ROUTE 50 CORRIDOR
COULD ACTUALLY USE SOME RAIN.
MAXIMUM TEMPERATURE FORECAST TODAY DEPENDENT ON AFTERNOON COVERAGE
OF CONVECTION... BUT TRIED TO STAY SLIGHTLY UNDER MOST 00Z MOS
GUIDANCE...AND LOWER THAN THE OBSERVED ON SUNDAY.
THE LOWEST CEILINGS SHOULD BE ASSOCIATED WITH THE FRONT...SO LEAVING
LINGERING SHOWERS IN THE WAKE OF THE FRONT THRU 12Z TUESDAY NEAR THE
OHIO RIVER...WITH SOME LIKELY POPS AT 12Z TUESDAY STILL OVER THE
CENTRAL WV MOUNTAINS WITH THE FRONT.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
COLD FRONT WILL BE PUSHING EAST OF THE CWA BY MIDDAY TUESDAY. SEVERAL
UPPER LEVEL SHORTWAVE TROUGHS WILL ROTATE AROUND A 500MB LOW OVER
QUEBEC...SO LINGER POPS THROUGH MUCH OF THE DAY. OVERALL TROUGH AXIS
PASSES LATE TUESDAY...HOWEVER NAM AND GFS SHOW ANOTHER RATHER POTENT
SHORTWAVE TROUGH/VORT MAX DIGS IN ON WEDNESDAY. THE ECMWF KEEPS THINGS
FARTHER NORTH. THIS FEATURE SHOULD BE FIGHTING INCREASINGLY DRIER AIR
IN THE LOW LEVELS...BUT DID INCLUDE ISOLATED TO SCATTERED SHOWERS
ACROSS NORTHERN AND EASTERN CWA.
HIGH TEMPS WILL GENERALLY BE BELOW NORMAL THROUGH THE SHORT TERM.
LOWS SHOULD BE JUST A TOUCH BELOW NORMAL TUESDAY NIGHT AS COLD AIR
FILTERS IN...AND THEN A MILD 5-10 DEGREES BELOW NORMAL WEDNESDAY
NIGHT.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A FRESH AIRMASS WILL SETTLE IN FOR THE EXTENDED WITH MILD
COMFORTABLE DAYS AND COOL NIGHTS. SOME MODERATION OVER THE
WEEKEND.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
ONE MID LEVEL DISTURBANCE MOVING THROUGH SRN WV AT 06Z WITH
A FEW LIGHT SHOWERS. WIDESPREAD CLOUDS AT 4 TO 10 THSD FT SHOULD
LIMITED COVERAGE OF ANY THICKER FOG THIS MORNING. ANY BREAKS COULD
BRING BRIEF IFR IN WV MOUNTAIN VALLEYS SUCH AS EKN.
CONVECTION DROPPING SE THROUGH WRN KY TOWARD TN BUT A FEW SHOWERS
MAY FORM FURTHER E AND AFFECT SW VA THIS MORNING.
WILL HAVE MOSTLY 3 TO 5 THSD FT SCT TO BKN AGL TODAY WITH LAYERS
ABOVE. COULD NOT TIME ANY DEFINITE ROUNDS OF CONVECTION THIS
AFTERNOON SO HAVE VCNTY THUNDERSTORM IN MOST TAF SITES. TRIED TO
INCREASE COVERAGE IN SE OHIO AFTER 20Z...THEN MOVE INTO WV FOR 00Z
TO 06Z. CEILINGS LOWER NEAR FRONT TO 2 TO 3 THSD FT BKN TO OVC AND
VSBY NEAR 3 MILES IN ANY SHOWER/STORM.
WITH WEAK LOW PRESSURE DEVELOPING IN UPPER OHIO VALLEY
TODAY...HAVE ITS ASSOCIATED FRONT/WIND SHIFT REACHING INTO OUR SE
OHIO BY 06Z TUESDAY. CEILINGS DETERIORATING FURTHER BUT MOSTLY
AFTER 06Z TUESDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: SPECIFIC TIMING OF ROUNDS OF CONVECTION THIS
AFTERNOON AND OVERNIGHT TONIGHT WILL VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 08/10/15
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EDT 1HRLY 02 03 04 05 06 07 08 09 10 11 12 13
CRW CONSISTENCY H H M M H H H H H H H H
HTS CONSISTENCY H H M M H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY M M L L L M M H H H H H
PKB CONSISTENCY H H M M H H H H H H H H
CKB CONSISTENCY H H M M M H H H H H H H
AFTER 06Z TUESDAY...
NEAR AND IN WAKE OF FRONT...LINGERING LOW CEILINGS AND SHOWERS
THROUGH TUESDAY MORNING.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...KTB
SHORT TERM...MZ
LONG TERM...30
AVIATION...KTB
AREA FORECAST DISCUSSION
NWS NORMAN OK
1226 PM CDT MON AUG 10 2015
.DISCUSSION...
AVIATION DISCUSSION FOR THE 18Z TAFS IS BELOW.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED TO CONTINUE.
ISO-SCT -SHRA/-TSRA WILL AFFECT SOME SITES MAINLY NORTH OF KHBR-
KOUN THROUGH 21Z. ADDITIONAL SHRA/TSRA MAY OCCUR AFTER 21Z...BUT
ONLY KEPT PROB30 MENTION NEAR KWWR AND KGAG 06-10Z AS CONFIDENCE
OF OCCURRENCE REMAINS RATHER LOW.
PATCHES OF MVFR/IFR CONDITIONS MAY OCCUR NORTH OF KHBR-KOKC 08-16Z...
PARTICULARLY NEAR KWWR AND KGAG...BUT DID NOT MENTION DUE TO LOW
CONFIDENCE OF OCCURRENCE.
MBS
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT MON AUG 10 2015/
UPDATE...
LOWERED TEMPS A FEW DEGREES ACROSS THE NORTH AND ADJUSTED POPS
SLIGHTLY.
DISCUSSION...
SCATTERED SHOWERS AND STORMS CONTINUE ALONG A WEAK MID LEVEL
CONVERGENCE ZONE ACROSS NORTH CENTRAL OK. THIS ZONE WILL SLOWLY
SHIFT SOUTHWARD DURING THE DAY BUT WITH LITTLE TO NO OTHER
SUPPORT PRESENT (LLJ DISSIPATING) EXPECT COVERAGE WILL DIMINISH
THROUGH THIS AFTERNOON. THE HRRR APPEARS TO HAVE A PRETTY GOOD
HANDLE ON THE FORECAST SO WEIGHTED POPS HEAVILY TOWARDS IT.
TEMPS WHERE ALSO LOWERED 2-4 DEGREES ACROSS NORTHERN OK...AND
PORTIONS OF CENTRAL OK...WHERE CLOUD COVER WILL LIKELY LINGER
THROUGH THE DAY. ALL UPDATED PRODUCTS HAVE BEEN SENT.
PREV DISCUSSION... /ISSUED 338 AM CDT MON AUG 10 2015/
DISCUSSION...
MAIN CONCERNS WILL BE PRECIP ACROSS THE NORTH AND HEAT FARTHER
SOUTH TODAY AND THEN COOL-OFF AND PRECIP CHANCES THIS WEEK.
CONT TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS NORTHWEST
INTO NORTHERN OKLAHOMA THIS MORNING NEAR A SLOW MOVING COLD FRONT.
THIS FRONT IS A BIT SLOWER THAN MODELS HAVE BEEN SHOWING. THIS
WILL ALLOW FOR TEMPS TO BE A BIT WARMER ACROSS PARTS OF THE AREA
TODAY. BECAUSE OF THIS WE WILL END UP WITH SOME HIGHER HEAT
INDICES AND WILL NECESSITATE THE NEED TO BRING THE HEAT ADVISORY
FARTHER NORTH INTO CENTRAL OKLAHOMA.
FRONT STILL EXPECTED TO PUSH SOUTH TOWARD THE RED RIVER BY TUESDAY
MORNING. SLIGHTLY COOLER TEMPS EXPECTED BEHIND THE FRONT. AS THIS
IS OCCURRING... UPPER RIDGE WILL BE BUILDING BACK NORTH ACROSS THE
SOUTHERN/CENTRAL ROCKIES. MODELS CONT TO INDICATE AT LEAST A
CHANCE FOR SOME ADDITIONAL PRECIP CHANCES INTO THE MIDDLE OF THE
WEEK AS WE COME UNDER THE INFLUENCE OF WEAK NORTHWEST FLOW.
HOWEVER TODAY`S MODEL RUNS HAVE SHIFTED THE MOISTURE PLUME FARTHER
WEST AND KEEP MUCH IN THE WAY OF PRECIP CONFINED TO FAR WESTERN
OKLAHOMA AND THE EASTERN TEXAS PANHANDLE AS WE GET INTO WED/THU
TIMEFRAME.
BEYOND THIS IT APPEARS THAT MOISTURE PLUME WILL DISSIPATE AND
UPPER FLOW BECOMES MORE NORTHERLY AS UPPER RIDGE CONT BUILD NORTH
AND NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS. ALTHOUGH
DRY... THIS PATTERN SHOULD KEEP THE HOTTEST TEMPS TO OUR WEST AND
NORTH BY LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 96 74 90 70 / 30 20 10 10
HOBART OK 97 74 93 70 / 30 20 20 20
WICHITA FALLS TX 104 76 97 73 / 0 10 20 10
GAGE OK 91 70 87 68 / 50 30 30 20
PONCA CITY OK 92 73 89 68 / 60 10 0 10
DURANT OK 104 77 97 73 / 0 10 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ025>032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
03/14/17
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1057 AM CDT MON AUG 10 2015
.UPDATE...
LOWERED TEMPS A FEW DEGREES ACROSS THE NORTH AND ADJUSTED POPS
SLIGHTLY.
&&
.DISCUSSION...
SCATTERED SHOWERS AND STORMS CONTINUE ALONG A WEAK MID LEVEL
CONVERGENCE ZONE ACROSS NORTH CENTRAL OK. THIS ZONE WILL SLOWLY
SHIFT SOUTHWARD DURING THE DAY BUT WITH LITTLE TO NO OTHER
SUPPORT PRESENT (LLJ DISSIPATING) EXPECT COVERAGE WILL DIMINISH
THROUGH THIS AFTERNOON. THE HRRR APPEARS TO HAVE A PRETTY GOOD
HANDLE ON THE FORECAST SO WEIGHTED POPS HEAVILY TOWARDS IT.
TEMPS WHERE ALSO LOWERED 2-4 DEGREES ACROSS NORTHERN OK...AND
PORTIONS OF CENTRAL OK...WHERE CLOUD COVER WILL LIKELY LINGER
THROUGH THE DAY. ALL UPDATED PRODUCTS HAVE BEEN SENT.
&&
.PREV DISCUSSION... /ISSUED 338 AM CDT MON AUG 10 2015/
DISCUSSION...
MAIN CONCERNS WILL BE PRECIP ACROSS THE NORTH AND HEAT FARTHER
SOUTH TODAY AND THEN COOL-OFF AND PRECIP CHANCES THIS WEEK.
CONT TO SEE SHOWERS AND THUNDERSTORMS DEVELOP ACROSS NORTHWEST
INTO NORTHERN OKLAHOMA THIS MORNING NEAR A SLOW MOVING COLD FRONT.
THIS FRONT IS A BIT SLOWER THAN MODELS HAVE BEEN SHOWING. THIS
WILL ALLOW FOR TEMPS TO BE A BIT WARMER ACROSS PARTS OF THE AREA
TODAY. BECAUSE OF THIS WE WILL END UP WITH SOME HIGHER HEAT
INDICES AND WILL NECESSITATE THE NEED TO BRING THE HEAT ADVISORY
FARTHER NORTH INTO CENTRAL OKLAHOMA.
FRONT STILL EXPECTED TO PUSH SOUTH TOWARD THE RED RIVER BY TUESDAY
MORNING. SLIGHTLY COOLER TEMPS EXPECTED BEHIND THE FRONT. AS THIS
IS OCCURRING... UPPER RIDGE WILL BE BUILDING BACK NORTH ACROSS THE
SOUTHERN/CENTRAL ROCKIES. MODELS CONT TO INDICATE AT LEAST A
CHANCE FOR SOME ADDITIONAL PRECIP CHANCES INTO THE MIDDLE OF THE
WEEK AS WE COME UNDER THE INFLUENCE OF WEAK NORTHWEST FLOW.
HOWEVER TODAY`S MODEL RUNS HAVE SHIFTED THE MOISTURE PLUME FARTHER
WEST AND KEEP MUCH IN THE WAY OF PRECIP CONFINED TO FAR WESTERN
OKLAHOMA AND THE EASTERN TEXAS PANHANDLE AS WE GET INTO WED/THU
TIMEFRAME.
BEYOND THIS IT APPEARS THAT MOISTURE PLUME WILL DISSIPATE AND
UPPER FLOW BECOMES MORE NORTHERLY AS UPPER RIDGE CONT BUILD NORTH
AND NORTHEAST INTO THE CENTRAL AND NORTHERN PLAINS. ALTHOUGH
DRY... THIS PATTERN SHOULD KEEP THE HOTTEST TEMPS TO OUR WEST AND
NORTH BY LATE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 96 74 90 70 / 30 20 10 10
HOBART OK 97 74 93 70 / 30 20 20 20
WICHITA FALLS TX 104 76 97 73 / 0 10 20 10
GAGE OK 91 70 87 68 / 50 30 30 20
PONCA CITY OK 92 73 89 68 / 60 10 0 10
DURANT OK 104 77 97 73 / 0 10 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR OKZ025>032-039>043-
045>048-050>052.
TX...NONE.
&&
$$
03/14
AREA FORECAST DISCUSSION
NWS MEDFORD OR
231 PM PDT MON AUG 10 2015
.DISCUSSION...CURRENT WATER VAPOR IMAGE SHOWS THE UPPER LOW MARCHING
SOUTH ALONG 130 W. IT ALSO SHOWS A WEAK SHORTWAVE MOVING INTO
SOUTHWEST OREGON BRINGING HIGH AND MID LEVEL CLOUDS WHICH WILL
CONTINUE TO MOVE NORTHEAST. THE STRONGER SHORTWAVE THAT MOVED
THROUGH LAKE AND EASTERN KLAMATH COUNTY HAS MOVED NORTH OF OUR AREA
AND INCREASED LIGHTNING STRIKES HAVE SHOWN UP IN NORTHEAST OREGON
AND TOWARDS THE BLUE MOUNTAINS. GENERALLY CLEAR SKIES ARE IN ITS
WAKE, BUT CUMULUS ARE STARTING TO BUILD UP OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES AND NORTHERN CAL.
LOOKING AT DATA SUGGEST THE BEST CHANCE FOR SCATTERED THUNDERSTORMS
WILL BE LATE THIS AFTERNOON AND EVENING AND MOST CENTERED OVER THE
CASCADES. THE MODELS SHOW THE LOWEST LI`S AND HIGHEST BOUNDARY LAYER
CAPE VALUES AND THETA E CONVERGENCE IN THESE AREAS LATE THIS
AFTERNOON. IN ADDITION THE 700 MB WINDS AND THE 700-500MB WINDS WILL
BE FROM THE SOUTH, THEN SHIFT EVER SO SLIGHTLY TO THE SOUTH TO
SOUTHWEST THIS EVENING. THEREFORE WE THINK THE MAJORITY OF
THUNDERSTORMS WILL REMAIN IN THESE AREAS LATE THIS AFTERNOON AND
EVENING. HOWEVER WINDS ALOFT WILL BE STRONGER, THEREFORE STORMS THAT
FORM OVER WESTERN SISKIYOUS COUNTY AND SISKIYOU MOUNTAINS WILL GET
CARRIED NORTH INTO THE WEST SIDE VALLEYS, BUT THEY WILL BE RUNNING
IN AN ENVIRONMENT THAT IS LESS UNSTABLE AND ALSO WITH LESS MID LEVEL
MOISTURE. ALSO STORMS THAT FORM OVER THE CASCADES COULD GET PULLED
SLIGHTLY WESTWARD AND SCATTERED STORMS ARE POSSIBLE ALONG THE
FOOTHILLS OF THE CASCADES IN EASTERN DOUGLAS COUNTY.
OF NOTE THE PAST SEVERAL RUNS OF HIGH RES HRRR MODEL (WHICH UPDATES
HOURLY) CONTINUES TO SHOW VERY LITTLE ACTIVITY FROM THE CASCADES
WEST. IT ACTUALLY SHOWS A FRONTAL BOUNDARY ARRIVING AT THE COAST BY
THIS EVENING USHERING MORE STABLE CONDITIONS BRINGING LIGHT RAIN
WITH MOST OF THE CONVECTION IN MODOC AND LAKE COUNTY. MOST OF THE
CONVECTIVE FEEDBACK IS EAST OF THE CASCADES IN PARTS OF KLAMATH AND
LAKE COUNTY. NOT SURE IF THIS IS CORRECT, BUT IT MAY BE ON TO
SOMETHING GIVEN THE CONSISTENCY FROM RUN TO RUN. SO ITS ENTIRELY
POSSIBLE NOT MUCH WILL HAPPEN WEST OF THE CASCADES.
TONIGHT, THE MODELS ARE IN FRIARLY GOOD AGREEMENT SHOWING WINDS AT
700 AND 700-500MB REMAIN SOUTH TO SOUTHWEST. THE NAM SHOWS MORE OF A
SOUTHEAST COMPONENT OVERNIGHT TONIGHT, BUT THE GFS DOES NOT. THE NAM
SHOWS LIFTED INDICES (LI`S) LOWERING TO AROUND -5 C ALONG THE
COOS/DOUGLAS COUNTY LINE, BUT SUSPECT THAT MAY BE OVERDONE. IN
CONTRAST THE GFS SHOWS LI`S AROUND -1C. THE NAM CONTINUES TO SHOW A
SHORTWAVE MOVING WEST OF THE CASCADES OVERNIGHT TONIGHT, BUT THE GFS
IS MUCH WEAKER. BECAUSE OF THE ABOVE MENTIONED REASONS, WE THINK
THERE WILL BE NOCTURNAL STORMS WEST OF THE CASCADES, BUT THEY WILL
BE ISOLATED.
ON TUESDAY MOST OF THE INSTABILITY WILL BE WEST OF THE CASCADES.
HOWEVER WE`LL ALSO HAVE A MARINE INFLUENCE NEAR THE COAST WHICH
SHOULD STABILIZE THINGS SOME, SO WE DON`T THINK THUNDERSTORMS WILL
BE A CONCERN THERE. SHORTWAVES WILL ROTATE IN FROM THE SOUTHEAST
AHEAD OF THE UPPER LOW AND THIS IN COMBINATION WITH LOWEST LI`S AND
HIGHEST BL CAPE CENTERED FROM WESTERN SISKIYOU COUNTY NORTHEAST
TOWARDS EASTERN DOUGLAS COUNTY COULD BE ENOUGH TO GENERATE ISOLATED
THUNDERSTORMS. OF NOTE THE HIGHEST BL CAPE VALUES AND LOWEST LI`S
ARE IN THE NORTHERN CASCADES NORTH OF CRATER LAKE, SO THERE`S A
CHANCE FOR SCATTERED STORMS THERE.
NOT MUCH CHANGE IN THE PATTERN IS EXPECTED TUESDAY NIGHT THROUGH
WEDNESDAY. THE UPPER LOW WILL REMAIN NEARLY STATIONARY, THEN SLOWLY
MOVE NORTHWARD WEDNESDAY AFTERNOON AS THE UPSTREAM UPPER TROUGH
MOVES TOWARDS WESTERN B.C. THE MODELS PUT THE GREATEST INSTABILITY
ALONG THE CASCADES AND WESTERN SISKIYOU COUNTY TUESDAY NIGHT, THEN
BECOMING MORE STABLE ON WEDNESDAY, THEREFORE THE CONCERN FOR
NOCTURNAL STORMS EXIST AGAIN TUESDAY NIGHT, THEN THE THREAT OF
STORMS SHIFTS NORTH WEDNESDAY.
THE UPPER LOW WILL MOVE INLAND AND ACROSS THE AREA THURSDAY
AFTERNOON AND WE EXPECT A BETTER CHANCE OF SHOWERS AND THUNDERSTORMS
ALONG WITH A BRIEF COOL DOWN. THE UPPER LOW WILL FINALLY KICK
NORTHEAST OF THE AREA FRIDAY AFTERNOON AND A WEAK TROUGH REMAINS,
BUT IT WILL STAY DRY WITH MILDER TEMPERATURES.
WINDS WILL BE ANOTHER CONCERN, PARTICULARLY OVER THE HIGHER TERRAIN
ALONG AND EAST OF THE CASCADES THIS AFTERNOON THROUGH AT LEAST
THURSDAY AFTERNOON. ALSO WINDS ARE ALIGNED UP PRETTY WELL IN THE
SHASTA VALLEY WITH 700MB WINDS BETWEEN 25-35 KTS, SOME OF WHICH
COULD MIX DOWN NEAR THE SURFACE. THE MODEL GUIDANCE SHOWS WIND GUSTS
BETWEEN 45-50 KTS, BUT SUSPECT THIS MAY BE A BIT OVERDONE. THIS IS
BECAUSE THE PRESSURE GRADIENT IS NOT STRONG LIKE WE TYPICALLY SEE IN
THE WINTER THAT WOULD PRODUCE WIND GUST OF THIS MAGNITUDE. SO WHILE
WE EXPECT WINDS TO INCREASE AROUND THE WEED AREA, THEY WON`T BE
ENOUGH TO REACH ADVISORY CRITERIA.
A THERMAL TROUGH WILL DEVELOP ALONG THE COAST FRIDAY NIGHT THROUGH
SATURDAY WITH INCREASING OFFSHORE FLOW. THE PATTERN THAT IS SETTING
UP IS FAVORABLE FOR A CHETCO EFFECT AND THE HIGH TEMPERATURES IN
BROOKINGS COULD EASILY GET INTO THE MID TO UPPER 80S OR LOW 90S.
MEANWHILE TEMPERATURES WILL HEAT UP IN THE WEST SIDE VALLEYS WITH
READINGS IN THE LOWER TO MID 90S. DRY CONDITIONS CONTINUE SUNDAY AND
THE THERMAL TROUGH WILL SHIFT INLAND OVER THE WEST SIDE VALLEYS WITH
TEMPERATURES EXPECTED TO BE IN THE MID 90S.
KEEP IN MIND WHILE THE MODELS REMAIN IN GOOD AGREEMENT WITH THE
OVERALL PATTERN THE NEXT FEW DAYS, THE MAIN CHALLENGE WILL BE
ADDRESSING THE DETAILS OF THE WEATHER, ESPECIALLY AS IT RELATES TO
THUNDERSTORM COVERAGE, SHOWERS AND PATCHY TO AREAS OF SMOKE.
CONFIDENCE REMAINS LOW REGARDING THE MOST FAVORABLE AREAS FOR
THUNDERSTORMS. THEREFORE DETAILS ON THIS COULD CHANGE FROM ONE DAY
TO THE NEXT SO STAY TUNED FOR THE LATEST UPDATES. -PETRUCELLI
&&
.AVIATION...FOR THE 10/18Z TAF CYCLE...ALONG THE COAST...IFR/MVFR
CIGS OFFSHORE WILL MOVE BACK ONSHORE THIS EVENING...THEN PERSIST
THROUGH MID-MORNING TUESDAY. INLAND...VFR CONDITIONS WILL
PREVAIL THROUGH TUESDAY MORNING...EXCEPT FOR AREAS OF MVFR VSBYS IN
SMOKE. ISOLATED TO SCATTERED THUNDERSTORMS WILL DEVELOP THIS
AFTERNOON WITH THE GREATER COVERAGE OVER THE CASCADES AND SISKIYOUS.
ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO THE MORNING
WEST OF THE CASCADES. STORMS MAY BRING ERRATIC AND GUSTY WINDS AND
LOCAL OBSCURATION OF HIGHER TERRAIN.
&&
.MARINE...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...A WEAK
SURFACE PRESSURE PATTERN WILL RESULT IN CALM WINDS AND SEAS OVER
THE NEXT SEVERAL DAYS, ALTHOUGH AN UPPER LEVEL DISTURBANCE COULD
BRING A FEW THUNDERSTORMS TO THE COASTAL WATERS TONIGHT INTO EARLY
TUESDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE COAST FRIDAY AND
SATURDAY, BRINGING WITH IT STRONG NORTH WINDS AND CHOPPY SEAS,
ESPECIALLY IN THE OUTER WATERS SOUTH OF CAPE BLANCO. ALTHOUGH
STILL TOO FAR OUT IN RANGE TO BE CERTAIN, GALES AND VERY STEEP
SEAS ARE POSSIBLE THIS WEEKEND INTO EARLY NEXT WEEK. -BPN
&&
.FIRE WEATHER...UPDATED 230 PM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASED TODAY...AND SO DID CLOUD COVER. THIS IS INHIBITING
THUNDERSTORM DEVELOPMENT OVER THE AREA...BUT SOME ARE STILL EXPECTED
TO DEVELOP. SCATTERED COVERAGE WILL EVENTUALLY DEVELOP OVER THE
CASCADES WITH ISOLATED COVERAGE OVER MOST OF THE OTHER INLAND AREAS.
ISOLATED THUNDERSTORMS MAY PERSIST THROUGH THE NIGHT...THEN BECOME
SCATTERED AGAIN OVER THE NORTHERN CASCADES TUESDAY AFTERNOON. GUSTY
SOUTH WINDS HAVE ALREADY DEVELOPED AND WILL CONTINUE THROUGH
THURSDAY...WHEN IT MAY BE ESPECIALLY WINDY ON THE EAST SIDE DUE TO
AN UPPER LEVEL TROUGH MOVING ONSHORE. AFTER THE TROUGH MOVES INLAND
...OFFSHORE LOW LEVEL FLOW WILL DEVELOP OVER THE COAST RANGE FRIDAY
NIGHT INTO SATURDAY NIGHT.
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING UNTIL 11 PM PDT THIS EVENING FOR
ORZ616-617-622>624.
RED FLAG WARNING FROM 5 PM TO 11 PM PDT TUESDAY FOR ORZ617-623.
CA...RED FLAG WARNING FROM 2 PM TO 8 PM PDT TUESDAY FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
AREA FORECAST DISCUSSION
NWS MEDFORD OR
957 AM PDT MON AUG 10 2015
.DISCUSSION...CURRENT VISIBLE IMAGE SHOWS A BAND OF CLOUDS MOVING
NORTH IN ASSOCIATION WITH A SHORTWAVE IN EASTERN KLAMATH AND LAKE
COUNTY. RETURNS FROM THIS FEATURE HAVE BEEN WEAK AND THERE HAVE
BEEN NO REPORTS OF ANY RAINFALL. ALSO NO LIGHTING STRIKES HAVE
BEEN OBSERVED IN OUR FORECAST AREA. THUS HAVE REMOVED POPS AND
THUNDER FROM THE FORECAST IN THESE AREAS. THE WATER VAPOR IMAGE
SHOWS THE UPPER LOW MARCHING SOUTH ALONG 130 W. IT`S ALSO PICKING
UP ON A WEAK SHORTWAVE MOVING INTO NORTHWEST CALIFORNIA AND THIS
WILL MOVE NORTHEAST.
LOOKING AT DATA THIS MORNING WOULD SUGGEST THE BEST CHANCE FOR
SCATTERED THUNDERSTORMS WILL BE LATE THIS AFTERNOON AND EVENING
AND MOST CENTERED OVER THE CASCADES, SISKIYOUS AND WESTERN
SIKSYOU COUNTY. THE MODELS SHOW THE LOWEST LI`S AND HIGHEST
BOUNDARY LAYER CAPE VALUES AND THETA E CONVERGENCE IN THESE AREAS
LATE THIS AFTERNOON. IN ADDITION THE 700 MB WINDS AND THE
700-500MB WINDS ARE FROM THE SOUTH THROUGH EARLY THIS AFTERNOON,
THEN SHIFT EVER SO SLIGHTLY TO THE SOUTH TO SOUTHWEST LATE THIS
AFTERNOON AND EVENING. THEREFORE WE THINK THE MAJORITY OF
THUNDERSTORMS WILL REMAIN IN THESE AREAS LATE THIS AFTERNOON AND
EVENING. HOWEVER WINDS ALOFT WILL BE STRONGER, THEREFORE STORMS
THAT FORM OVER WESTERN SIKSYOU COUNTY AND SISKIYOU MOUNTAINS WILL
GET CARRIED NORTH INTO THE WEST SIDE VALLEYS, BUT THEY WILL BE
RUNNING IN AN ENVIRONMENT THAT IS LESS UNSTABLE AND ALSO WITH
LESS MID LEVEL MOISTURE. ALSO STORMS THAT FORM OVER THE CASCADES
COULD GET PULLED SLIGHTLY WESTWARD AND SCATTERED STORMS ARE
POSSIBLE ALONG THE FOOTHILLS OF THE CASCADES IN EASTERN DOUGLAS
COUNTY.
OF NOTE THE HIGH RES HRRR MODEL SHOWS VERY LITTLE ACTIVITY FROM
THE CASCADES WEST. IT ACTUALLY SHOWS A FRONTAL BOUNDARY ARRIVING
AT THE COAST BY THIS EVENING USHERING MORE STABLE CONDITIONS
BRINGING LIGHT RAIN WITH MOST OF THE CONVECTION IN MODOC AND LAKE
COUNTY. NOT SURE IF THIS IS CORRECT, BUT IT MAY BE ON TO SOMETHING
GIVEN THE BAND OF CLOUDS JUST OFF THE COAST WHICH WILL PUSH
INLAND LATER THIS AFTERNOON.
FOR TONIGHT, THE MODELS ARE IN FRIARLY GOOD AGREEMENT SHOWING
WINDS AT 700 AND 700-500MB REMAIN SOUTH TO SOUTHWEST. THE NAM
SHOWS MORE OF A SOUTHEAST COMPONENT OVERNIGHT TONIGHT, BUT THE
GFS DOES NOT. THE NAM SHOWS LIFTED INDICES (LI`S) LOWERING TO
AROUND -5 C ALONG THE COOS/DOUGLAS COUNTY LINE, BUT SUSPECT THAT
MAY BE OVERDONE. IN CONTRAST THE GFS SHOWS LI`S AROUND -1C. THE
NAM CONTINUES TO SHOW A SHORTWAVE MOVING WEST OF THE CASCADES
OVERNIGHT TONIGHT, BUT THE GFS IS MUCH WEAKER. BECAUSE OF THE
ABOVE MENTIONED REASONS, WE THINK THUNDERSTORMS WILL BE ISOLATED
WEST OF THE CASCADES. -PETRUCELLI
&&
.AVIATION...FOR THE 10/12Z TAF CYCLE...ALONG THE COAST...MVFR TO
IFR CIGS ARE LINGERING MAINLY NORTH OF CAPE BLANCO THIS MORNING,
BUT EXPECT THAT THIS WILL BURN BACK OFFSHORE BY LATE MORNING WITH
VFR CONDITIONS EXPECTED TO LAST INTO TONIGHT. INLAND...VFR
CONDITIONS WILL PREVAIL FOR THE NEXT 24 HOURS. HOWEVER
THUNDERSTORMS WILL BE A CONCERN AFTER 21Z AND THEY COULD BRING
ERRATIC AND GUSTY WINDS. -PETRUCELLI
&&
.MARINE...UPDATED 830 AM PDT MONDAY 10 AUGUST 2015...A WEAK
SURFACE PRESSURE PATTERN WILL PREVAIL THROUGH THURSDAY NIGHT WITH
OCCASIONALSHOWERS. WINDS WILL BE 10 KT OR LESS AND SEAS LESS THAN 4
FEET THROUGH THURSDAY NIGHT. AN UPPER LEVEL DISTURBANCE WILL ALSO
BRING A SLIGHT CHANCE FOR THUNDERSTORMS TO THE COASTAL WATERS MONDAY
NIGHT INTO EARLY TUESDAY. A THERMAL TROUGH WILL DEVELOP NEAR THE
COAST FRIDAY AND SATURDAY...BRINGING WITH IT STRONG NORTH WINDS AND
CHOPPY SEAS...STRONGEST IN THE OUTER WATERS SOUTH OF CAPE BLANCO.
&&
.FIRE WEATHER...UPDATED 345 AM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASES TODAY...BRINGING MONSOONAL MOISTURE TO THE AREA ALONG
WITH MODERATE TO STRONG SOUTHERLY TO SOUTHWESTERLY
WINDS...ESPECIALLY OVER THE RIDGES AND OCCASIONALLY IN NORTH TO
SOUTH ORIENTED VALLEYS SUCH AS THE SHASTA VALLEY. THUNDERSTORMS WILL
DEVELOP...AFTER A WEAK SHORT WAVE BRINGS CLOUDS AND AN OCCASIONAL
CLAP OF THUNDER EARLY THIS MORNING AS IT MOVES THROUGH FROM THE
SOUTH...THIS AFTERNOON AND EVENING. STORMS WILL LIKELY DEVELOP IN
THE MOUNTAINS SOUTH OF WESTERN SISKIYOU COUNTY AS THE CLOUDS CLEAR
FROM THE SOUTH...BUILDING NORTH INTO THE CASCADES LATER IN THE
AFTERNOON. THE BEST AREA OF THUNDERSTORM INITIATION SHOULD BE IN
WESTERN SISKIYOU COUNTY TO THE NORTH AND EAST INTO THE CASCADES.
STRONG STEERING 700 MB WINDS WILL THEN MOVE THESE CELLS TO THE NORTH-
NORTHWEST ACROSS THE WEST SIDE IN A BROAD AREA OF INSTABLITY WITH
CELLS MOVING GENERALLY AT 15-20 MPH TO THE NORTH AND NORTH-
NORTHWEST. ELEVATED INSTABILITY REMAINS OVER NIGHT ON THE WEST
SIDE...AND WITH ANOTHER SHORT WAVE MOVING ACROSS OVERNIGHT IN THIS
AREA OF ELEVATED INSTABLITY HAVE EXTENDED THE RED FLAG WARNING TO
15Z AND MOVED THE AREA UP TO THE COAST AND NORTH TO INCLUDE ONLY THE
SW OREGON FIRE WEATHER ZONES. -SVEN
&&
.PREV DISCUSSION... /ISSUED 406 AM PDT MON AUG 10 2015/
DISCUSSION...AN UPPER LEVEL LOW PRESSURE SYSTEM IS SPINNING NEAR
47N AND 130W EARLY THIS MORNING. THE MAIN BAND OF RAIN WITH THIS
SYSTEM IS BEYOND ABOUT 60 NM FROM SHORE THIS MORNING AND WILL
LIKELY STAY OUT OVER THE WATER AND GRADUALLY WEAKEN OVER TIME.
MEANWHILE, WATER VAPOR IMAGERY IS SHOWING A SHORT WAVE LIFTING
NORTHWARD THROUGH THE SACRAMENTO VALLEY THIS MORNING AND SOME MID-
LEVEL MOISTURE IS FUNNELING NORTHWARD IN ADVANCE OF THIS FEATURE.
RADAR IS SHOWING SOME SHOWERS ENTERING SOUTHERN MODOC COUNTY
CURRENTLY AND THERE HAVE BEEN SOME ISOLATED CLOUD TO GROUND
STRIKES IN LASSEN COUNTY IN THE LAST HOUR. SINCE THESE SHOWERS ARE
MOVING INTO AN AREA OF ELEVATED INSTABILITY, EXPECT SOME ISOLATED
THUNDERSTORMS FROM MODOC INTO LAKE COUNTY, ESPECIALLY NEAR THE
WARNERS THROUGH THIS MORNING. THIS SHORT WAVE WILL LIFT NORTHWARD
THROUGH THE AREA BY EARLY THIS AFTERNOON.
OF NOTE, WINDS BEGIN TO ALIGN WITH THE SHASTA VALLEY THIS
AFTERNOON AND EVENING AND THEY`LL REMAIN THAT WAY THROUGH
THURSDAY, SO WE SHOULD SEE SOME PRETTY GOOD SOUTH TO SOUTHEAST
WIND GUSTS NEAR WEED (30-40 MPH)...JUST SHY OF WIND ADVISORY
LEVELS.
AS THE UPPER LOW DIGS SOUTHWARD TODAY, AN UNSTABLE AIR MASS WILL
DEVELOP OVER THE MARBLE/SISKIYOU/CASCADE MOUNTAINS WITH STEEP
LAPSE RATES (>7.5C/KM) AND AMPLE SURFACE-BASED CAPE (500-1000
J/KG). COMPUTED LIS ARE -2 TO -6. MID-UPPER LEVEL WIND SHEAR WILL
ALSO INCREASE (45-55KT) AS SHORTWAVES RIDE NORTH, THEN
NORTHWESTWARD ON INCREASING SOUTH-SOUTHEAST FLOW ALOFT. MID-LEVEL
MOISTURE (700-500MB) APPEARS TO BE ONE POTENTIAL LIMITING FACTOR
FOR CONVECTION TODAY, BUT THERE SHOULD STILL BE ISOLATED TO
SCATTERED THUNDERSTORMS. SINCE WINDS ALOFT ARE PRETTY STRONG, ANY
STORMS THAT DO DEVELOP WILL HAVE THE POTENTIAL TO PRODUCE GUSTY
WINDS AND SMALL HAIL. THEY WILL ALSO BE ABLE TO MOVE OUT AND OVER
THE VALLEYS THIS EVENING DUE TO THE STRONG SOUTH-SOUTHEAST MID-
LEVEL FLOW (25-35KT). IT SHOULD BE NOTED THAT THE AIR MASS WILL
REMAIN UNSTABLE TONIGHT INTO TUESDAY MORNING WEST OF THE CASCADES
AND ADDITIONAL STORMS MAY CONTINUE TO DEVELOP AND MOVE
NORTHWESTWARD. INSTABILITY IS ELEVATED AND THIS MAY RESULT IN
STORMS MOVING OUT OVER THE OCEAN. FOR THESE REASONS, WE HAVE
EXPANDED THE AREA OF THE CURRENT RED FLAG WARNINGS WESTWARD TO THE
COAST, BUT PRIMARILY NORTH OF PORT ORFORD.
BY TUESDAY AFTERNOON, THE UPPER LOW WILL BE RIGHT NEAR 40N AND
130W. SHORT WAVE ACTIVITY IS MINIMAL THROUGH ABOUT EARLY
AFTERNOON, BUT ANOTHER ONE IS EXPECTED TO ROTATE INTO THE AREA
DURING THE LATE AFTERNOON OR EVENING. THE BEST INSTABILITY IS FROM
THE CASCADES WESTWARD, BUT AGAIN, MOISTURE IS SOMEWHAT LACKING.
WE`LL MAINTAIN THE SLIGHT CHANCE TO CHANCE THUNDER THREAT. THE
AIR MASS STABILIZES ACROSS THE SOUTH AND EAST, SO IT SHOULD JUST
BE PARTLY TO MOSTLY SUNNY THERE WITH SOME GUSTY AFTERNOON BREEZES.
ON WEDNESDAY, THE UPPER LOW WILL STILL BE IN THE SAME GENERAL
POSITION NEAR 40N AND 130 W, BUT MODELS ARE SHOWING MUCH LESS
INSTABILITY ACROSS THE REGION. WE HAVE BACKED OFF ON THE THUNDER
THREAT, WITH JUST A SLIGHT CHANCE OF SHOWERS AGAIN MAINLY FROM
THE CASCADES WESTWARD.
BY WEDNESDAY NIGHT, AS HAS BEEN ADVERTISED FOR SEVERAL RUNS NOW, A
SHORT WAVE DISTURBANCE WILL MOVE INTO BRITISH COLUMBIA AND THIS
SHOULD ALLOW THE UPPER LOW TO EJECT AND MOVE ACROSS THE PACIFIC
NORTHWEST ON THURSDAY. THIS SHOULD BRING AN AREA OF SHOWERS AND
THUNDERSTORMS ACROSS A GOOD PORTION OF THE CWA ALONG AND WEST OF
THE CASCADES THROUGH THURSDAY EVENING ALONG WITH A COOL DOWN. THE
AIR MASS WILL DRY OUT THURSDAY NIGHT, BUT A PIECE OF THE UPPER
TROUGH WILL HANG BACK OVER THE AREA FRIDAY. THIS WILL KEEP
TEMPERATURES FROM WARMING UP TOO QUICKLY, BUT WE DO EXPECT
MODERATING TEMPS FOR THE WEEKEND. SPILDE
AVIATION...FOR THE 10/12Z TAF CYCLE...ALONG THE COAST...MVFR TO
IFR CIGS ARE HANGING OFFSHORE THIS MORNING WITH SOME STRATUS
DEVELOPING VCTY KOTH. EXPECT THAT THIS WILL MOVE ONTO THE SHORE
BRIEFLY BEFORE BURNING BACK OFFSHORE BY LATE MORNING. INLAND...VFR
CONDITIONS WILL PREVAIL THIS MORNING...EXCEPT FOR AREAS OF SMOKE
MOSTLY OVER SOUTHERN AND EASTERN DOUGLAS COUNTY...JACKSON
COUNTY...AND THE UPPER KLAMATH BASIN. AFTER A WEAK DISTURBANCE MOVES
MID CLOUDS THROUGH THE REGION EARLY THIS MORNING FROM THE SOUTH...
CUMULUS WILL DEVELOP EARLY THIS AFTERNOON OVER THE AREA FROM WESTERN
SISKIYOU COUNTY ACROSS THE SISKIYOU MOUNTAINS TO THE SOUTHERN OREGON
CASCADES AND NORTHERN PORTIONS OF KLAMATH AND LAKE COUNTIES WITH
ISOLATED TO SCATTERED THUNDERSTORMS EXPECTED TO FORM AROUND 22Z AND
LATER THIS AFTERNOON AND CONTINUE INTO THE EVENING. WITH ELEVATED
INSTABILITY AND A SHORT WAVE MOVING ACROSS WEST OF THE CASCADES AT
LEAST ISOLATED THUNDERSTORMS ARE EXPECTED TO CONTINUE INTO THE
MORNING WEST OF THE CASCADES. STORMS MAY BRING ERRATIC AND GUSTY
WINDS. -SVEN
MARINE...UPDATED 345 AM PDT MONDAY 10 AUGUST 2015...A WEAK SURFACE
PRESSURE PATTERN WILL PREVAIL THROUGH THURSDAY NIGHT WITH OCCASIONAL
SHOWERS ALONG WITH LIGHT WINDS AND SEAS. AN UPPER LEVEL DISTURBANCE
WILL ALSO BRING A SLIGHT CHANCE FOR THUNDERSTORMS TO THE COASTAL
WATERS TONIGHT INTO EARLY TUESDAY. WIND DIRECTION WILL VARY FROM
SOUTH TO NORTH THROUGH THURSDAY...BUT WILL REMAIN BELOW 10 KT WITH
SEAS 4 FEET OR LESS. THE THERMAL TROUGH WILL RETURN ON FRIDAY AND
STRENGTHEN INTO SATURDAY...BRINGING A RETURN OF MODERATE TO STRONG
NORTH WINDS AND CHOPPY SEAS. THESE WINDS WILL BE STRONGEST IN THE
OUTER WATERS SOUTH OF CAPE BLANCO. -SVEN
FIRE WEATHER...UPDATED 345 AM PDT MONDAY 10 AUGUST 2015...SOUTHERLY
FLOW INCREASES TODAY...BRINGING MONSOONAL MOISTURE TO THE AREA ALONG
WITH MODERATE TO STRONG SOUTHERLY TO SOUTHWESTERLY
WINDS...ESPECIALLY OVER THE RIDGES AND OCCASIONALLY IN NORTH TO
SOUTH ORIENTED VALLEYS SUCH AS THE SHASTA VALLEY. THUNDERSTORMS WILL
DEVELOP...AFTER A WEAK SHORT WAVE BRINGS CLOUDS AND AN OCCASIONAL
CLAP OF THUNDER EARLY THIS MORNING AS IT MOVES THROUGH FROM THE
SOUTH...THIS AFTERNOON AND EVENING. STORMS WILL LIKELY DEVELOP IN
THE MOUNTAINS SOUTH OF WESTERN SISKIYOU COUNTY AS THE CLOUDS CLEAR
FROM THE SOUTH...BUILDING NORTH INTO THE CASCADES LATER IN THE
AFTERNOON. THE BEST AREA OF THUNDERSTORM INITIATION SHOULD BE IN
WESTERN SISKIYOU COUNTY TO THE NORTH AND EAST INTO THE CASCADES.
STRONG STEERING 700 MB WINDS WILL THEN MOVE THESE CELLS TO THE NORTH-
NORTHWEST ACROSS THE WEST SIDE IN A BROAD AREA OF INSTABILITY WITH
CELLS MOVING GENERALLY AT 15-20 MPH TO THE NORTH AND NORTH-
NORTHWEST. ELEVATED INSTABILITY REMAINS OVER NIGHT ON THE WEST
SIDE...AND WITH ANOTHER SHORT WAVE MOVING ACROSS OVERNIGHT IN THIS
AREA OF ELEVATED INSTABILITY HAVE EXTENDED THE RED FLAG WARNING
TO 15Z AND MOVED THE AREA UP TO THE COAST AND NORTH TO INCLUDE
ONLY THE SW OREGON FIRE WEATHER ZONES. -SVEN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR... RED FLAG WARNING FROM 11 PM THIS EVENING TO 8 AM PDT TUESDAY FOR
ORZ615-619.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 8 AM PDT TUESDAY
ABOVE 500 FEET FOR FOR ORZ616-620.
RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR ORZ617-621>624.
CA...RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 11 PM PDT THIS
EVENING FOR CAZ280-281.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH TUESDAY
EVENING FOR CAZ281.
PACIFIC COASTAL WATERS...NONE.
$$
MAP/MAP/MAP
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
614 PM EDT MON AUG 10 2015
.SYNOPSIS...
A FRONTAL SYSTEM OVER THE OHIO VALLEY WILL MOVE THROUGH THE
REGION OVERNIGHT AND EARLY TUESDAY. COOLER AND DRIER AIR WILL
FOLLOW FOR THE MIDWEEK PERIOD. TEMPERATURES WILL REBOUND LATE
THIS WEEK WITH HIGH PRESSURE BUILDING EAST FROM THE MID
MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
EARLY EVENING RADAR MOSAIC SHOWING WIDESPREAD SHRA/TSRA ACROSS NW
PA IN ADVANCE OF APPROACHING UPPER TROF. SPC MESOANALYSIS
INDICATING SOME MODEST CAPES OF ARND 1000 J/KG ACROSS WESTERN
PA...WHERE THERE WAS SOME SUNSHINE EARLIER TODAY. FURTHER
EAST...MOIST SERLY FLOW YIELDING MARINE LYR STRATUS BUT NO PRECIP
ACROSS MOST OF CENTRAL PA.
EXPECT SHRA TO OVERSPREAD THE REGION FROM WEST TO EAST DURING THE
LATE EVENING HOURS...AS UPPER TROF AND PRECEDING LL JET/PLUME OF
ANOMALOUS PWATS OVERSPREAD THE STATE. SPC HAD PLACED THE
ALLEGHENY PLATEAU IN A MRGL RISK AREA FOR SVR WX THIS EVENING.
HOWEVER...GIVEN DIMINISHING CAPES AND NEARLY NON-EXISTENT
DCAPES...BELIEVE THE THREAT OF SVR WX IS LOW. GREATER RISK MAY BE
ISOLD FLOODING ACROSS THE NW MTNS...WHERE LINGERING INSTABILITY...COMBINED
WITH SURGING PWATS...COULD PRODUCE LOCALIZED EXCESSIVE RAINFALL.
HPC HAS OUTLINED OUR NORTHERN AREAS FOR POTENTIALLY HEAVY RAINS.
SHORT TERM GUIDANCE SHOWS A PRETTY QUICK PROGRESSION ACROSS THE
STATE OF THE LOW LEVEL JET AND AXIS OF DEEPEST MOISTURE. WILL HAVE
TO WATCH FOR THE POTENTIAL FOR TRAINING CONVECTION IN THE MOISTURE
RICH TROPICAL AIRMASS. SPC SSEO AND LATEST HRRR TARGET THE NW
MTNS FOR LOCALIZED AMTS 3+ INCHES. HAVE MENTIONED SLIGHT RISK OF
FLOODING ACROSS THIS AREA IN THE HWO...BUT GIVEN RECENT
DRYNESS...FEEL ODDS OF FLASH FLOODING NOT HIGH ENOUGH FOR A WATCH
ATTM.
STRONG FRONTAL PASSAGE...ANOMALOUS PWATS AND LATEST GEFS/SREF
OUTPUT ALL SUPPORT NR 100 PCT POPS OVERNIGHT ACROSS ALL OF CENTRAL
PA. BEST CHANCE WILL COME BEFORE MIDNIGHT ACROSS THE WESTERN
COUNTIES AND AFTER MIDNIGHT ACROSS THE EASTERN COS. SHORT TERM
GUIDANCE TIMES THE LOW LEVEL JET EAST OF THE ENTIRE REGION BY
12Z...RESULTING IN THE STEADIEST RAIN EXITING OUR EASTERN COUNTIES
ARND DAWN. LOWS IN THE MID 60S TO LOWER 70S WILL FEEL RATHER
TROPICAL.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
THE MAIN AXIS OF MOISTURE AND LOW LEVEL FORCING WILL HAVE SHIFTED
EAST OF THE AREA BY EARLY TUESDAY...BUT SHORT RANGE OPERATIONAL
MODELS SUGGEST THE SURFACE FRONT WILL BE SLOW TO MOVE
THROUGH...AND BY AFTERNOON THEY DEVELOP A NOT INSIGNIFICANT
AMOUNT OF CAPE AS THE UPPER TROUGH DEEPENS OVERHEAD. EASTERN AREAS
ARE PAINTED WITH A MARGINAL THREAT FOR SEVERE TOMORROW...WHICH
SEEMS REASONABLE DEPENDING ON THE EVENTUAL PROGRESS OF THE SURFACE
BOUNDARY. OTHERWISE THERE WILL BE SCATTERED SHOWERS AND A THREAT
FOR THUNDERSTORMS WITH THE BEST CHANCES FAVORING THE EASTERN HALF
OF THE FORECAST AREA.
HIGHS FROM THE MID 70S TO MID 80S WILL BE SEVERAL DEGREES COOLER
THAN NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
BEHIND TUESDAY/S FRONTAL PASSAGE...ANY LINGERING SHOWERS WILL
QUICKLY TAPER OFF AS TUESDAY NIGHT PROGRESSES. AN UPPER LEVEL
TROUGH WILL DEEPEN OVERHEAD AND COOLER TEMPERATURES WILL MOVE
INTO THE REGION FOR WEDNESDAY AND THURSDAY. BOTH THE GEFS AND THE
NAEFS CONTINUE TO FORECAST SLIGHTLY BELOW NORMAL 850 MB
TEMPERATURES OVER THE FORECAST AREA. ADDITIONALLY...NORTHWEST FLOW
ACROSS THE AREA WILL RESULT IN MOUNTAIN SHOWERS WEDNESDAY
AFTERNOON AND EVENING.
A SURFACE HIGH WILL BUILD SOUTHWEST OF THE AREA ON
THURSDAY...BRINGING CLEARER CONDITIONS. THE UPPER LEVEL TROUGH WILL
BECOME MORE SHALLOW FRIDAY AS THE SURFACE HIGH PUSHES EAST TOWARDS
THE ATLANTIC COAST AND TEMPERATURES WILL BEGIN TO REBOUND UNDER A
MORE WESTERLY FLOW.
A COLD FRONT WILL MOVE THROUGH FRIDAY AND SATURDAY...BRINGING
ANOTHER CHANCE FOR SHOWERS AND AFTERNOON THUNDERSTORMS. THE FRONT
PUSHES EAST OF PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL
RETURN FOR SUNDAY AND MONDAY.
&&
.AVIATION /22Z MONDAY THROUGH SATURDAY/...
AS NOTED BELOW...LOW CLDS OVER MUCH OF THE AREA. HOWEVER...WILL
BE WATCHING THE ENTIRE AREA CLOSELY THIS EVENING...AS A STRONG
JET AND DRY PUNCH HEAD TOWARD THE AREA. LOW PRESSURE WILL MOVE
TOWARD THE LOWER LAKES. PATTERN SUPPORTS STORMS WITH HEAVY RAIN.
POTENTIAL FOR SOME STRONG STORMS TOO...ESPECIALLY ACROSS THE
WEST LATER THIS EVENING.
SOME ADJUSTMENTS MADE TO THE TAFS AT 4 PM. WILL ADJUST MORE
HERE FOR THE 21Z TAFS. LOW CIGS OVER MUCH OF THE AREA AT THE
CURRENT TIME.
EARLIER DISCUSSION BELOW.
MARITIME FLOW IN THE LOW LEVELS HAS LED TO A LARGE SHIELD OF LOW
CLOUDS HANGING TOUGH OVER MUCH OF THE CENTRAL RIDGE MOUNTAIN
AREA...WITH WESTERNMOST TERMINALS JOHNSTOWN AND BRADFORD
UNCHARACTERISTICALLY ENJOYING THE BEST CONDITIONS.
THE LOW CLOUDS MAY SLOWLY LIFT FOR A TIME FROM ALTOONA THROUGH
STATE COLLEGE UP INTO WILLIAMSPORT...BUT IMPROVEMENT WILL LIKELY
BE SHORT LIVED WITH CONDITIONS EXPECTED TO DETERIORATE ONCE AGAIN
THIS EVENING AND OVERNIGHT AS PRECIPITATION DEVELOPS AND MOVES
INTO THE FLYING AREA.
THE COLD FRONT WILL MOVE EAST OF THE REGION TUESDAY...WITH A
DRIER WESTERLY FLOW EXPECTED TO DEVELOP. THERE WILL STILL BE THE
THREAT FOR SCATTERED SHOWERS AND THUNDERSTORMS AS AN UPPER
DISTURBANCE CROSSES THE REGION BUT MVFR/IFR EARLY IN THE DAY
SHOULD IMPROVE BY AFTERNOON WITH THE DRIER WESTERLY FLOW.
OUTLOOK...
WED...MOSTLY VFR...SCT SHOWERS WEST.
THU-FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI-SAT...VFR...SCATTERED SHOWERS. POSSIBLE PM THUNDER.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD/LA CORTE
SHORT TERM...LA CORTE
LONG TERM...HAGNER
AVIATION...LA CORTE/MARTIN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
351 AM EDT MON AUG 10 2015
.SYNOPSIS...
RETURN FLOW OFF THE GULF OF MEXICO WILL BRING IN MOISTURE TODAY
AHEAD OF THE NEXT COLD FRONT. EXPECT SHOWERS AND THUNDERSTORMS AHEAD
OF THE FRONT UNTIL THIS FRONT PASSES LATE TUESDAY. COOLER AND DRIER
HIGH PRESSURE WILL BE IN CONTROL OF OUR WEATHER FROM WEDNESDAY INTO
NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
SOME LINGERING -SHRA/TSTMS ACROSS THE NC PIEDMONT AND EXTREME SRN
ZONES THIS MORNING. THIS ACTIVITY IS REMAINING FAIRLY STATIONARY
ALONG THE EDGE OF A ERN SFC HIGH WITH MOIST W/LY LIFT. SOME
ADDITIONAL CELLS COULD FILL IN THROUGH DAYBREAK...BUT OVERALL THE
ACTIVITY WILL REMAIN SHALLOW WITH ECHO TOPS AROUND 20 KFT. ENUF CELL
MOVEMENT IS EVIDENT TO HAVE MUCH OF A HYDRO CONCERN...BUT WILL
MONITOR FOR ANY POSSIBLE ISSUES.
THE FCST FOR THIS AFTERNOON IS A LITTLE TRICKY AS CLOUD COVER ACROSS
THE ERN ZONES SHOULD INHIBIT DEEP INSTABILITY UNTIL LATE DAY. PLAN
VIEW SBCAPE SHOWS THE BEST POTENTIAL ACROSS THE UPPER SAVANNAH
VALLEY AND NORTH ACROSS THE BLUE RIDGE AND MOST OF THE UPSTATE.
THERE IS NOT A LOT OF DYNAMIC FORCING TO BE HAD. THE H3 FLOW DOES
BECOME DIFFLUENT AND THIS WILL HELP BRING IN A PRE/FRONTAL
TROF...BUT NO WELL DEFINED NOR ACUTE S/W ENERGY SHOULD BE AVAILABLE.
EXCEPT PERHAPS ACROSS NE GA AND THE FAR WRN UPSTATE PER SOME HIRES
MOD SOLNS. SO...EXPECT ISOL TSTM ACTIVITY TO BEGIN ACROSS THE MTNS
AND ARND 17Z OR SO...THEN SLOWLY FILL IN TO THE EAST THROUGHOUT THE
AFTERNOON/EVENING. POPS HAVE BEEN BUMPED DOWN ACROSS THE NC PIEDMONT AND
SE/RN UPSTATE DUE TO UNCERTAINTY WITH INSTABILITY AND PROGRESSION OF
THE PF/TROF. THE STRONGER STORMS WILL DEVELOP ACROSS NE GA ALONG
THE SC BORDER AND THE SRN BLUE RIDGE. BULK SHEAR IS NOT THAT
IMPRESSIVE...ON THE ORDER OF 20 KTS...BUT AREAS OF GOOD DIFF HEATING
COULD SUPPORT ISOL SEVERE CONVECTION.
THE BETTER ULVL ENERGY AND A S/W TROF MOVES INTO THE NC MTNS AFT 00Z
WHICH WILL THEN CROSS THE FA THROUGH THE OVERNIGHT. CROSS SECTIONS
DEPICT AROUND 150 J/KG OF ELCAPE...SO THUNDER MENTION WILL REMAIN
ALL ZONES WHILE POPS DROP TO THE LOWER CHANCE RANGE BY DAYBREAK. THE
UPPER PATTERN BECOMES MORE CYCLONIC AND DIFFLUENT OVERNIGHT AS
WELL...SO STRONG AND HIGH RAINFALL RATE STORMS ARE POSSIBLE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 AM MON...SFC COLD FRONT IS PROGGED TO PUSH THRU THE AREA
TUE ENHANCING FORCING IN AN OTHERWISE FAVORABLE ENVIRONMENT FOR DEEP
CONVECTION. FRONTAL TROUGH AXIS WILL CROSS THE MTNS IN THE MRNG AND
MODEST COVERAGE OF SHRA/TSRA IS EXPECTED THEN. DESTABILIZATION WILL
OCCUR PRIOR TO THE FRONT ITSELF. HIGHER RES GUIDANCE SUGGESTS THE
MRNG ACTIVITY WILL DISSIPATE AND/OR PROPAGATE OUT OF THE AREA BEFORE
A SECOND ROUND DEVELOPS OVER THE MTNS WITH THE FRONT.
THE PIEDMONT ACTIVITY...PARTICULAR THAT BEGINNING EARLIER IN THE
DAY...POSES A HEAVY RAIN THREAT DUE TO PWAT VALUES AT OR ABOVE THE
90TH PERCENTILE...BUT AS DRIER AIR WORKS IN ALOFT BEHIND THE TROUGH
PWATS DIP BACK TO VALUES NEAR CLIMATOLOGICAL MEDIAN. STORMS SHOULD
MOVE PRETTY QUICKLY GIVEN THE BRISK FLOW ALOFT...AND NO WELL-DEFINED
LLJ IS SEEN ON PROFILES. SO ANY HYDRO CONCERNS APPEAR LIKELY TO
REMAIN LOCALIZED ESPECIALLY IN LIGHT OF DRY SOIL CONDITIONS OVERALL.
INSTABILITY IS NOT THE GREATEST BUT SHEAR IS APPRECIABLE. 0-6KM BULK
VALUES PEAK AT 30-35 KT WHICH WILL ALLOW AT LEAST LOOSE ORGANIZATION.
SO AT THE OTHER END OF THE SPECTRUM...AS DRYING OCCURS ALOFT THE
LATER ROUND OF STORMS WILL BE CAPABLE OF DAMAGING WINDS ON A SOMEWHAT
LARGER SCALE THAN WE OFTEN SEE THIS TIME OF YEAR. SPC DAY 2 OUTLOOK
PAINTS OUR PIEDMONT IN A MARGINAL RISK AREA BUT THERE APPEARS TO BE
SOME RISK THROUGHOUT THE AREA...UNLESS THE FRONT ARRIVES EARLIER THAN
ANTICIPATED.
THE FRONT BRINGS DRIER AND COOLER AIR ACRS THE AREA TUE NIGHT AS POPS
DROP TO UNMENTIONABLY LOW VALUES. DIURNAL CONVECTION IS NOT EXPECTED
WED AND DEWPOINTS WILL BE COMFORTABLY LOW FOR MID-AUGUST. MINS THU
MORNING WILL BE SLIGHTLY BELOW CLIMO ALSO.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 AM TUE...HIGHLY AMPLIFIED UPPER PATTERN FEATURING SHARP ERN
TROUGH AND WRN RIDGE EXPECTED THU...BEGINNING TO BREAK DOWN BY LATE
FRI AS THE TROUGH LIFTS AND RIDGE BEGINS TO SHEAR. AT THE SFC THIS
MEANS BROAD SFC HIGH PRESSURE SPREADS EAST. A PORTION OF THE
RETREATING TROUGH SHEARS OFF OVER THE CENTRAL GULF COAST SATURDAY
POSSIBLY LEADING TO THE DEVELOPMENT OF A SFC LOW ALONG STALLED FRONT.
THESE FEATURES INITIATE MOIST RETURN FLOW FRI WHICH MAY CONTINUE INTO
THE WEEKEND PER GFS SOLUTION. THIS WOULD PROBABLY ALLOW SOME DIURNAL
CONVECTION TO RESUME AT LEAST OVER THE BLUE RIDGE. THE 09/12Z EC AND
TO SOME EXTENT THE 10/00Z GEM DEPICT A SECOND SFC HIGH MOVING THRU
THE OHIO VALLEY WHICH LEADS IT TO KEEP A DRIER AND MORE NORTHERLY
FLOW INTO OUR AREA. MAINLY SCHC POPS ARE MENTIONED EACH DAY OF THE
PERIOD...AND MAINLY NEAR THE BLUE RIDGE. TEMPS WILL START OFF A FEW
DEGREES BELOW CLIMO IN THE CONTINENTAL AIRMASS...MODERATING TO NEAR
CLIMO BY SUNDAY NIGHT AS IT MODIFIES.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
AT KCLT...CONTINUED IDEA OF PREVIOUS TAF WITH BRINGING IN LOW SCT
STCU BEFORE SUNRISE. NOT ENUF MOISTURE RESPONSE ON RAP SOUNDINGS TO
GO FOR A CIG ATTM. STILL EXPECT TSTMS THIS AFTERNOON...BUT MAY HAVE
TO PUSH BACK TIMING ON THE 12Z TAF. MODEL PROGRESSION OF MUCAPE IS
IS SLOW TO MOVE EAST AS LLVL CLOUD COVER COULD PERSIST THROUGH NOON
OR SO. IN FACT THE PREFRONTAL DEEP CONVECTION MAY REMAIN WEST OF
THE TERMINAL UNTIL LATE IN THE PERIOD.
ELSEWHERE...SOME MVFR/IFR IS POSSIBLE AT KAVL AND KHKY THIS MORNING
AS TTD/S ARE RUNNING 1-2 F. POSSIBLE VSBY CONCERNS ACROSS THE SC
SITES AS WELL ARND DAYBREAK. CONVECTIVE ACTIVITY WILL AFFECT KAVL
ARND 18Z AS PREFRONTAL TROF DEVELOPS AND FORCING SPREADS EAST
INDUCING THUNDER AT THE OTHER TERMINALS 1-3 HRS LATER. PRECIP AND
THUNDER WILL PERSIST NEAR ALL TERMINALS LATE IN THE TAF PERIOD WITH
SOME VSBY/CIGS ISSUES PROBABLE.
OUTLOOK...HEAVY RAINFALL MON AFTN/EVENING ASSOCIATED WITH THE COLD
FRONT/SHORTWAVE COULD LEAD TO SOME MORNING RESTRICTIONS TUE.
DRIER/VFR CONDITIONS RETURN BY TUE EVENING...AND SHOULD PREVAIL THRU
AT LEAST THURSDAY.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 83% HIGH 89% HIGH 100% HIGH 93%
KAVL HIGH 84% HIGH 88% HIGH 96% HIGH 83%
KHKY HIGH 86% HIGH 82% HIGH 100% HIGH 97%
KGMU HIGH 91% MED 76% HIGH 90% HIGH 93%
KAND HIGH 87% HIGH 93% HIGH 100% HIGH 93%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...WIMBERLEY
NEAR TERM...SBK
SHORT TERM...WIMBERLEY
LONG TERM...WIMBERLEY
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
134 AM EDT MON AUG 10 2015
.SYNOPSIS...
A SOUTH TO SOUTHWEST WIND FLOW WILL DEVELOP TONIGHT AND CONTINUE INTO
MONDAY BRINGING IN MOISTURE OFF THE GULF AHEAD OF THE NEXT COLD
FRONT. EXPECT SHOWERS AND THUNDERSTORMS AHEAD OF THE FRONT UNTIL
THIS FRONT PASSES LATE TUESDAY. COOLER AND DRIER HIGH PRESSURE WILL
BE IN CONTROL OF OUR WEATHER FOR THE LAST HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 130 AM EDT MONDAY...NO SIGFNT CHANGES NEEDED TO THE GOING
FCST. CLOUD COVER WAS UPDATED TO ACCOUNT FOR THICK CI ADV ACROSS THE
NRN ZONES. MADE SOME MINOR TWEAKS TO T/TD GRIDS ACROSS THE UPSTATE.
AS OF 1030 PM EDT SUNDAY...ONLY ISOLATED CONVECTION STILL OUT THERE
THIS EVENING BUT RAPIDLY DISSIPATING. MOST GRIDS LOOK GOOD WITH ONLY
MINOR CHANGES BASED ON OBSERVATIONAL TRENDS.
AS OF 730 PM EDT SUNDAY...VERY FEW ADDITIONAL CHANGES TO THE GRIDS
THIS EVENING WITH JUST MINOR TWEAKS TO POPS/SKY/TEMPS/DEWPOINTS.
CONVECTION IS BEGINNING TO WANE AS EXPECTED THOUGH THERE IS STILL
SOME ENHANCED CU AT THE HIGHER ELEVATIONS...BUT THE TREND IS
DEFINITELY DOWN. STILL MONITORING OVERNIGHT FOG POTENTIAL WHICH WILL
BE HEAVILY DEPENDENT ON HOW THE GROUND RESPONDS TO THE RAINFALL THIS
EVENING. OVERALL NO SIGNIFICANT CHANGES AT THIS TIME.
AS OF 430 PM EDT SUNDAY...HAVE INCREASED POPS ACROSS MAINLY THE
UPSTATE TO ACCOUNT FOR INCREASING SHOWER ACTIVITY. ONLY ISOLATED
LIGHTNING STRIKES HERE AND THERE SO KEPT THUNDER WORDING AT CHANCE
WITH LIKELY SHOWERS. VERY EFFICIENT RAINFALL PRODUCERS WITH ONE
REPORT OF 2 INCHES IN 45 MINUTES IN TRANSYLVANIA COUNTY. WILL
CONTINUE TO MONITOR AND ADJUST POPS ACCORDINGLY AS NECESSARY. MADE
SIMILAR ADJUSTMENTS TO SKY COVER FOR THE NEXT FEW HOURS...AND SOME
MINOR TWEAKS TO HOURLY TEMPS/WINDS/DEWPOINTS BASED ON OBS.
AS OF 230 PM EDT SUNDAY...CU FIELD IS BUBBLING INTO ISOLATED SHOWERS
ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA. WITH CAPE GENERALLY
LIMITED TO THE 1000-1500 J/KG RANGE ACROSS THIS AREA...IT/S
DEBATABLE AS TO WHETHER ANY UPDRAFTS WILL BECOME STRONG ENOUGH TO
PRODUCE LIGHTNING...BUT WILL CONTINUE A MENTION OF ISOLATED/WIDELY
SCT SHOWERS AND STORMS ACROSS THE WESTERN 2/3 OF THE FORECAST AREA
THROUGH THE AFTERNOON. ANY LINGERING CONVECTION SHOULD DISSIPATE
RATHER QUICKLY AFTER SUNSET...GIVING WAY TO A TYPICALLY WARM/MUGGY
NIGHT...WITH MIN TEMPS EXPECTED TO AVERAGE A COUPLE OF DEGREES ABOVE
CLIMO...POSSIBLY EVEN WARMER DEPENDING UPON IF/HOW SOON LOW CLOUDS
EXPAND ACROSS THE FORECAST AREA WITHIN INCREASING SOUTHERLY FLOW
REGIME.
SUBSTANTIVE UPPER HEIGHT FALLS WILL OVERSPREAD THE EASTERN CONUS BY
THE END OF THE NEAR TERM PERIOD...ALLOWING FOR RETROGRESSION OF THE
LONG WAVE PATTERN. HIGHER RESOLUTION SHORT TERM MODELS ARE IN GOOD
AGREEMENT IN DROPPING A SHORT WAVE TROUGH INTO WESTERN NC BY MONDAY
AFTERNOON...ACCOMPANIED BY INCREASING DEEP LAYER MOISTURE. IMPROVING
MID-LEVEL LAPSE RATES RESPONDING TO RIDGE RETROGRESSION SHOULD
RESULT IN IMPROVED...BUT STILL SOMEWHAT MODEST INSTABILITY PROFILES.
CONSIDERING THESE INGREDIENTS...COVERAGE OF CONVECTION SHOULD BE
QUITE RESPECTABLE MONDAY AFTERNOON...AND ANYWHERE FROM 50-70 POPS
WILL BE ADVERTISED...GENERALLY ALONG/NORTH OF I-85...TAPERING TO
30-40 PERCENT SOUTH OF THERE. DESPITE INCREASING SHEAR PROFILES
DEVELOP AS A CONSEQUENCE OF ANOMALOUSLY STRONG HEIGHT FALLS...THE
SEVERE CONVECTIVE THREAT APPEARS MARGINAL AT BEST MON PM...OWING TO
THE EXPECTED ABSENCE OF ROBUST INSTABILITY. STILL CAN/T RULE OUT
SOME ISOLATED SEVERE STORMS...ESP IF THE SHEAR PROVES STRONG ENOUGH
TO ORGANIZE SMALL CONVECTIVE CLUSTERS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 230 PM SUNDAY...A LARGE UPPER TROF WILL DIG ACRS THE GREAT
LAKES AND OHIO VALLEY MONDAY NIGHT THRU TUESDAY...SHARPENING THE
TROF AXIS ALONG THE APPALACHIANS BY WEDNESDAY. THIS WILL COINCIDE
WITH A COLD FROPA ON TUESDAY...WHICH SHUD HAVE DECENT QG FORCING AND
MOISTURE FOR GOOD CONVECTIVE COVERAGE. MOISTURE AND UPGLIDE AHEAD OF
THE FRONT WILL KEEP A CHC POP THRU THE OVERNIGHT MONDAY NIGHT. THEN
ON TUESDAY...THE MODELS ARE IN DECENT AGREEMENT ON THE FRONT
CROSSING THE CWFA TUESDAY EVENING. THERE SHUD STILL BE PLENTY OF
INSTBY FOR AT LEAST A SOLID CHC POP ALONG AND EAST OF THE BLUE
RIDGE. SBCAPE WILL RANGE FROM 1500-2500 J/KG PER THE GFS/NAM BLEND.
THE 0-6 KM BULK SHEAR WILL BE AROUND 25-30 KTS. SO EXPECT SOME
ORGANIZATION POTENTIAL WITH CONVECTION TUESDAY AFTN/EVE. THE DAY 3
CONVECTIVE OUTLOOK HAS A MARGINAL RISK ROUGHLY ALONG I-85 AND EAST.
TEMPS WILL BE A CATEGORY OR TWO ABOVE NORMAL MONDAY NIGHT AND
TUESDAY...THEN AT OR SLIGHTLY BELOW NORMAL TUESDAY NIGHT AND
WEDNESDAY DRIER AIR AND COOLER THICKNESSES COME IN BEHIND THE FRONT.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 145 PM SUNDAY...STARTING AT 00Z THURSDAY...THE 500MB PATTERN
SHOWS A TROUGH OVER THE EAST WITH AXIS ALONG THE APPALACHIANS AND A
RIDGE OVER THE ROCKIES. GOING INTO FRIDAY AND SATURDAY...THE
SOUTHERN PART OF THE EASTERN TROUGH IS EXPECTED SHEAR OFF GRADUALLY
INTO A CUT OFF UPPER LOW WHICH SHOULD BE FORMED BY SATURDAY NIGHT
OVER THE MISS DELTA. THIS CUT OFF LOW IS EXPECTED TO DRIFT WEST TO
THE TEXAS COAST BY SUNDAY NIGHT WHICH IS THE END OF THE CURRENT
FORECAST PERIOD.
AT THE SURFACE FOR WED NIGHT...DRY HIGH PRESSURE CENTERED NEAR
CHICAGO AND A STALLED OUT FRONT FROM THE GULF COAST TO NRN FLORIDA
THEN OUT OVER THE ATLANTIC OFF THE CAROLINA COAST. THE FRONT IS
CLOSE ENOUGH THROUGH THE EARLY WEEKEND THAT IF A STRONG WAVE OF LOW
PRESSURE WERE TO PASS ALONG IT...THE RESULT MAY BE A FEW SHOWERS FOR
OUR SE ZONES MAINLY OVER THE PIEDMONT OR OVER THE FAR SOUTHERN MTNS.
CURRENT LOW LEVEL WIND FORECAST HAS A NORTHERLY WIND WED
NIGHT...PERHAPS AN UPSLOPE WIND FROM THE EAST TO SE THURSDAY AND
THURSDAY NIGHT...THEN LIGHT AND VARIABLE THROUGH SUNDAY NIGHT. ON
SUNDAY...THE FRONT IS FORECAST TO DRIFT MORE SOUTH OVER FLORIDA AND
DRIER AIR OVER OUR AREA WITH HIGH PRESSURE. ALTHOUGH CAPES ARE
FORECAST TO BE AROUND 2000 OR ABOVE FOR THE NC MTNS LATE SAT AND
SUN...THERE IS VERY LITTLE MOISTURE. TEMPS A FEW DEGREES BELOW
NORMAL THURSDAY THEN SLOWLY RECOVERING TO AROUND NORMAL SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...CONTINUED IDEA OF PREVIOUS TAF WITH BRINGING IN LOW SCT
STCU BEFORE SUNRISE. NOT ENUF MOISTURE RESPONSE ON RAP SOUNDINGS TO
GO FOR A CIG ATTM. STILL EXPECT TSTMS THIS AFTERNOON...BUT MAY HAVE
TO PUSH BACK TIMING ON THE 12Z TAF. MODEL PROGRESSION OF MUCAPE IS
IS SLOW TO MOVE EAST AS LLVL CLOUD COVER COULD PERSIST THROUGH NOON
OR SO. IN FACT THE PREFRONTAL DEEP CONVECTION MAY REMAIN WEST OF
THE TERMINAL UNTIL LATE IN THE PERIOD.
ELSEWHERE...SOME MVFR/IFR IS POSSIBLE AT KAVL AND KHKY THIS MORNING
AS TTD/S ARE RUNNING 1-2 F. POSSIBLE VSBY CONCERNS ACROSS THE SC
SITES AS WELL ARND DAYBREAK. CONVECTIVE ACTIVITY WILL AFFECT KAVL
ARND 18Z AS PREFRONTAL TROF DEVELOPS AND FORCING SPREADS EAST
INDUCING THUNDER AT THE OTHER TERMINALS 1-3 HRS LATER. PRECIP AND
THUNDER WILL PERSIST NEAR ALL TERMINALS LATE IN THE TAF PERIOD WITH
SOME VSBY/CIGS ISSUES PROBABLE.
OUTLOOK...HEAVY RAINFALL MON AFTN/EVENING ASSOCIATED WITH THE COLD
FRONT/SHORTWAVE COULD LEAD TO SOME MORNING RESTRICTIONS TUE.
DRIER/VFR CONDITIONS RETURN BY TUE EVENING...AND SHOULD PREVAIL THRU
AT LEAST THURSDAY.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-00Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 95% HIGH 90% HIGH 100%
KAVL HIGH 100% MED 78% HIGH 100% HIGH 93%
KHKY HIGH 100% HIGH 90% HIGH 85% HIGH 100%
KGMU HIGH 100% MED 68% MED 70% HIGH 100%
KAND HIGH 100% HIGH 95% HIGH 95% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...SBK/TDP
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...SBK
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1254 PM CDT MON AUG 10 2015
.UPDATE...
UPDATED TO ADD 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1057 AM CDT MON AUG 10 2015/
UPDATE...
UPDATED TO TRIM HEAT HEADLINES...UPDATE POPS...AND TEMPERATURES.
DISCUSSION...
A MESOSCALE CONVECTIVE SYSTEM THAT DEVELOPED OVERNIGHT CONTINUES
TO PROGRESS ACROSS THE NORTHERN HALF OF THE FORECAST AREA BUT IS
SHOWING A WEAKENING TREND. ALTHOUGH MUCH OF THIS MORNING
CONVECTION SHOULD DIMINISH WITHIN THE NEXT FEW HOURS...IT HAS
IMPACTED EXPECTED AFTERNOON HIGH TEMPERATURES AND HEAT INDEX
VALUES. HEAT INDEX VALUES ABOVE 105 DEGREES SHOULD NOW BE CONFINED
TO THE SOUTHERN TIER OF THE MID SOUTH WITH ALL LOCATIONS REMAINING
BELOW 110 DEGREES. HEAT HEADLINES HAVE BEEN UPDATED TO REFLECT
THIS NEW THINKING...TRIMMING AWAY NORTHERN COUNTIES OF THE
ADVISORY AND CANCELING THE EXCESSIVE HEAT WARNING.
UPDATED ZONES AND GRIDS HAVE BEEN SENT...WITH THE HWO UPDATED
SHORTLY.
JLH
PREV DISCUSSION... /ISSUED 439 AM CDT MON AUG 10 2015/
A COMPLEX WEATHER DAY ACROSS THE MIDSOUTH. THE UPPER LEVEL RIDGE
THAT BROUGHT TRIPLE DIGIT HEAT CLOSE TO THE MIDSOUTH YESTERDAY HAD
RETROGRADED OVER THE PAST 12 HOURS...RETURNING NORTHWEST FLOW
ALOFT TO THE MIDSOUTH.
SEVERAL THUNDERSTORM COMPLEXES HAD FORMED OVER SOUTHERN MO EARLY
THIS MORNING...MOVING SOUTHEAST ALONG THE UPPER RIDGE PERIPHERY.
ASSUMING THE COLD POOL CAN REMAIN ESTABLISHED THROUGH SUNRISE...
850-500MB THICKNESS FIELDS SUGGEST THESE STORMS WILL MOVE
SOUTH/SOUTHEAST THROUGH NORTHEAST AR...WEST TN AND NORTHEAST MS.
THE HRRR MODEL HAS BEEN CONSISTENT IN DEPICTING SUCH A SCENARIO.
THE AIRMASS FEEDING THESE STORMS WAS RICH WITH MOISTURE...WITH
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE LOW LEVEL JET
HAS BEEN A RELATIVELY WEAK 20KTS...BUT ADEQUATE TO MAINTAIN
STORMS EARLY THIS MORNING.
THUNDERSTORM EVOLUTION THROUGH MIDDAY WILL HAVE SIGNIFICANT
IMPACTS ON AFTERNOON HEAT INDICES. HAVE TRIMMED BACK HEAT
HEADLINES TO REFLECT THE IMPACTS OF THUNDERSTORM OUTFLOW AND
INITIAL CLOUD COVER. HEAT INDEX FORECAST CONFIDENCE IS MARGINAL...
BUT PERHAPS BEST OVER THE MS RIVER DELTA...FROM CLARKSDALE TO
CHARLESTON MS. THIS AREA WILL LEAST LIKELY BE IMPACTED BY
THUNDERSTORM OUTFLOW AND CLOUD COVER...AND NEAREST TO THE
AFTERNOON LOW LEVEL THERMAL RIDGE OVER SOUTHERN AR AND CENTRAL MS.
A WEAK COLD FRONTAL PASSAGE APPEARS ON TRACK FOR LATE THIS EVENING
AND EARLY OVERNIGHT. COOLER AND DRIER AIR WILL LAG 12 TO 18 HOURS
BEHIND THE INITIAL WIND SHIFT...BUT LIKELY SUFFICIENT TO KEEP
TUESDAY AFTERNOON HEAT INDICES BELOW ADVISORY CRITERIA.
WEDNESDAY AND THURSDAY SHOULD SEE COOLER AND DRIER CONDITIONS...WITH
NORTHERLY WINDS. DAYTIME TEMPS WILL GRADUALLY MODERATE TO NEAR
NORMAL VALUES FROM FRIDAY THROUGH NEXT MONDAY...AS THE UPPER RIDGE
BUILDS INTO THE MIDDLE MS RIVER VALLEY. RAIN CHANCES FROM MIDWEEK
THROUGH EARLY NEXT WEEK APPEAR MINIMAL.
PWB
&&
.AVIATION...
18Z TAF CYCLE
CONVECTIVE SYSTEM FROM THIS MORNING HAS TEMPORARILY STABILIZED THE
ATMOSPHERE. ADDITIONAL SHOWER AND THUNDERSTORM DEVELOPMENT MAY BE
POSSIBLE THROUGH EARLY EVENING BUT OVERALL CONFIDENCE REMAINS TOO
LOW TO JUSTIFY AT THIS TIME. W/NW WINDS BETWEEN 4-6 KTS WILL
BECOME LIGHT/NEARLY CALM TONIGHT AND INCREASE TO 5-8 KTS AFTER
11/15Z. PATCHY FOG MAY PRODUCE MVFR CONDITIONS LATE TONIGHT AT
JBR/TUP AND PERHAPS IFR/LIFR CONDITIONS AT MKL.
CJC
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR LEE AR-PHILLIPS.
MO...NONE.
MS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR CALHOUN-CHICKASAW-
COAHOMA-ITAWAMBA-LAFAYETTE-LEE MS-MONROE-PANOLA-PONTOTOC-
QUITMAN-TALLAHATCHIE-TATE-TUNICA-UNION-YALOBUSHA.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
601 AM CDT MON AUG 10 2015
.DISCUSSION... /ISSUED 439 AM CDT MON AUG 10 2015/
A COMPLEX WEATHER DAY ACROSS THE MIDSOUTH. THE UPPER LEVEL RIDGE
THAT BROUGHT TRIPLE DIGIT HEAT CLOSE TO THE MIDSOUTH YESTERDAY HAD
RETROGRADED OVER THE PAST 12 HOURS...RETURNING NORTHWEST FLOW
ALOFT TO THE MIDSOUTH.
SEVERAL THUNDERSTORM COMPLEXES HAD FORMED OVER SOUTHERN MO EARLY
THIS MORNING...MOVING SOUTHEAST ALONG THE UPPER RIDGE PERIPHERY.
ASSUMING THE COLD POOL CAN REMAIN ESTABLISHED THROUGH SUNRISE...
850-500MB THICKNESS FIELDS SUGGEST THESE STORMS WILL MOVE
SOUTH/SOUTHEAST THROUGH NORTHEAST AR...WEST TN AND NORTHEAST MS.
THE HRRR MODEL HAS BEEN CONSISTENT IN DEPICTING SUCH A SCENARIO.
THE AIRMASS FEEDING THESE STORMS WAS RICH WITH MOISTURE...WITH
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE LOW LEVEL JET
HAS BEEN A RELATIVELY WEAK 20KTS...BUT ADEQUATE TO MAINTAIN
STORMS EARLY THIS MORNING.
THUNDERSTORM EVOLUTION THROUGH MIDDAY WILL HAVE SIGNIFICANT
IMPACTS ON AFTERNOON HEAT INDICES. HAVE TRIMMED BACK HEAT
HEADLINES TO REFLECT THE IMPACTS OF THUNDERSTORM OUTFLOW AND
INITIAL CLOUD COVER. HEAT INDEX FORECAST CONFIDENCE IS MARGINAL...
BUT PERHAPS BEST OVER THE MS RIVER DELTA...FROM CLARKSDALE TO
CHARLESTON MS. THIS AREA WILL LEAST LIKELY BE IMPACTED BY
THUNDERSTORM OUTFLOW AND CLOUD COVER...AND NEAREST TO THE
AFTERNOON LOW LEVEL THERMAL RIDGE OVER SOUTHERN AR AND CENTRAL MS.
A WEAK COLD FRONTAL PASSAGE APPEARS ON TRACK FOR LATE THIS EVENING
AND EARLY OVERNIGHT. COOLER AND DRIER AIR WILL LAG 12 TO 18 HOURS
BEHIND THE INITIAL WIND SHIFT...BUT LIKELY SUFFICIENT TO KEEP
TUESDAY AFTERNOON HEAT INDICES BELOW ADVISORY CRITERIA.
WEDNESDAY AND THURSDAY SHOULD SEE COOLER AND DRIER CONDITIONS...WITH
NORTHERLY WINDS. DAYTIME TEMPS WILL GRADUALLY MODERATE TO NEAR
NORMAL VALUES FROM FRIDAY THROUGH NEXT MONDAY...AS THE UPPER RIDGE
BUILDS INTO THE MIDDLE MS RIVER VALLEY. RAIN CHANCES FROM MIDWEEK
THROUGH EARLY NEXT WEEK APPEAR MINIMAL.
PWB
&&
.AVIATION...
12Z TAF SET
LATEST HRRR SHOWS LINE OF CONVECTION THAT CURRENTLY STRETCHES FROM
NEAR KMKL BACK TO THE NW ACROSS SW MO WILL CONTINUE TO PUSH
SOUTHEAST THROUGH THE MIDSOUTH. CONVECTION SHOULD BE SOUTH OF KTUP
BY 20Z. THEREAFTER...LOW CONFIDENCE ON TAFS IF ANY REDEVELOPMENT
WILL OCCUR OR NOT. PUT IN VCTS WORDING AT KJBR AROUND 23Z FOR A
COUPLE OF HOURS BUT HAVE MY DOUBTS IF ATMOSPHERE WILL RECOVER AS
THICK CIRRUS DECK MAY BE OVER CWA FOR MOST OF DAY LIMITING DAYTIME
HEATING. IF CLOUDS CLEAR OVERNIGHT COULD SEE SOME DENSE FOG AT
SOME OF THE TAF SITES BUT FOR NOW HAVE LEFT MENTION OUT. WINDS
WILL TURN AROUND TO THE N GUSTING TO 25-30 KTS INITIALLY BEHIND
GUST FRONT MOVING SOUTHWARD. EXPECT WINDS SHOULD TURN BACK TO SSW
BEFORE SWITCHING BACK TO THE NORTH. WIND DIRECTION AND SPEED WILL
BE VARIABLE TODAY DUE TO THE CONVECTION.
KRM
&&
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR PHILLIPS.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR CRITTENDEN-CROSS-LEE AR-POINSETT-ST. FRANCIS.
MO...NONE.
MS...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR CALHOUN-COAHOMA-QUITMAN-TALLAHATCHIE-YALOBUSHA.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR BENTON MS-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TUNICA-
UNION.
TN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR FAYETTE-SHELBY.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
439 AM CDT MON AUG 10 2015
.DISCUSSION...
A COMPLEX WEATHER DAY ACROSS THE MIDSOUTH. THE UPPER LEVEL RIDGE
THAT BROUGHT TRIPLE DIGIT HEAT CLOSE TO THE MIDSOUTH YESTERDAY HAD
RETROGRADED OVER THE PAST 12 HOURS...RETURNING NORTHWEST FLOW
ALOFT TO THE MIDSOUTH.
SEVERAL THUNDERSTORM COMPLEXES HAD FORMED OVER SOUTHERN MO EARLY
THIS MORNING...MOVING SOUTHEAST ALONG THE UPPER RIDGE PERIPHERY.
ASSUMING THE COLD POOL CAN REMAIN ESTABLISHED THROUGH SUNRISE...
850-500MB THICKNESS FIELDS SUGGEST THESE STORMS WILL MOVE
SOUTH/SOUTHEAST THROUGH NORTHEAST AR...WEST TN AND NORTHEAST MS.
THE HRRR MODEL HAS BEEN CONSISTENT IN DEPICTING SUCH A SCENARIO.
THE AIRMASS FEEDING THESE STORMS WAS RICH WITH MOISTURE...WITH
PRECIPITABLE WATER VALUES AROUND 2.25 INCHES. THE LOW LEVEL JET
HAS BEEN A RELATIVELY WEAK 20KTS...BUT ADEQUATE TO MAINTAIN
STORMS EARLY THIS MORNING.
THUNDERSTORM EVOLUTION THROUGH MIDDAY WILL HAVE SIGNIFICANT
IMPACTS ON AFTERNOON HEAT INDICES. HAVE TRIMMED BACK HEAT
HEADLINES TO REFLECT THE IMPACTS OF THUNDERSTORM OUTFLOW AND
INITIAL CLOUD COVER. HEAT INDEX FORECAST CONFIDENCE IS MARGINAL...
BUT PERHAPS BEST OVER THE MS RIVER DELTA...FROM CLARKSDALE TO
CHARLESTON MS. THIS AREA WILL LEAST LIKELY BE IMPACTED BY
THUNDERSTORM OUTFLOW AND CLOUD COVER...AND NEAREST TO THE
AFTERNOON LOW LEVEL THERMAL RIDGE OVER SOUTHERN AR AND CENTRAL MS.
A WEAK COLD FRONTAL PASSAGE APPEARS ON TRACK FOR LATE THIS EVENING
AND EARLY OVERNIGHT. COOLER AND DRIER AIR WILL LAG 12 TO 18 HOURS
BEHIND THE INITIAL WIND SHIFT...BUT LIKELY SUFFICIENT TO KEEP
TUESDAY AFTERNOON HEAT INDICES BELOW ADVISORY CRITERIA.
WEDNESDAY AND THURSDAY SHOULD SEE COOLER AND DRIER CONDITIONS...WITH
NORTHERLY WINDS. DAYTIME TEMPS WILL GRADUALLY MODERATE TO NEAR
NORMAL VALUES FROM FRIDAY THROUGH NEXT MONDAY...AS THE UPPER RIDGE
BUILDS INTO THE MIDDLE MS RIVER VALLEY. RAIN CHANCES FROM MIDWEEK
THROUGH EARLY NEXT WEEK APPEAR MINIMAL.
PWB
&&
.AVIATION...
06Z TAF CYCLE
A MESOSCALE CONVECTIVE SYSTEM IS BACK BUILDING ACROSS SOUTHEASTERN
MO AND SOUTHERN IL. THIS SYSTEM IS EXPECTED TO GENERATE A SOUTHWARD
MOVING OUTFLOW BOUNDARY THAT WILL RESULT IN SCATTERED TO NUMEROUS
SHOWERS AND THUNDERSTORMS AFFECTING KMKL AND KJBR AFTER
10/08Z...KMEM AFTER 10/11Z AND CONTINUE THROUGH MUCH OF THE MORNING.
CONDITIONS MAY LOWER TO MVFR OR IFR IN THE HEAVIER THUNDERSTORMS
ESPECIALLY AT KMKL AND KJBR. SCATTERED SHOWERS AND THUNDERSTORMS
WILL DEVELOP ALONG AND AHEAD OF A COLD FRONT APPROACHING AND MOVING
INTO THE AREA FROM THE NORTH BEGINNING MONDAY AFTERNOON. VFR
CONDITIONS WILL OCCUR MUCH OF THE PERIOD AT THE TAF SITES OUTSIDE
ANY SHOWERS AND THUNDERSTORMS.
LIGHT WINDS TONIGHT BECOMING WESTERLY MONDAY 6-8 KTS. WINDS MAY BE
STRONG AND GUSTY NEAR THUNDERSTORMS.
AFTER 11/00Z...THE COLD FRONT WILL CONTINUE SOUTHWARD THOUGH THE
REGION. WINDS TURNING TO THE NE AT 4-7 KTS WITH THE THREAT OF
SHOWERS AND THUNDERSTORM ENDING FOLLOWING THE FRONT.
JCL
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR PHILLIPS.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR CRITTENDEN-CROSS-LEE AR-POINSETT-ST. FRANCIS.
MO...NONE.
MS...EXCESSIVE HEAT WARNING FROM 11 AM THIS MORNING TO 8 PM CDT THIS
EVENING FOR CALHOUN-COAHOMA-QUITMAN-TALLAHATCHIE-YALOBUSHA.
HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR BENTON MS-CHICKASAW-DESOTO-ITAWAMBA-LAFAYETTE-LEE MS-
MARSHALL-MONROE-PANOLA-PONTOTOC-PRENTISS-TATE-TIPPAH-TUNICA-
UNION.
TN...HEAT ADVISORY FROM 11 AM THIS MORNING TO 8 PM CDT THIS EVENING
FOR FAYETTE-SHELBY.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1034 PM CDT TUE AUG 11 2015
.DISCUSSION...UPDATE TO REMOVE RAIN CHANCES FOR VICTORIA AREA
AS CONVECTION HAS DISSIPATED.
&&
.PREV DISCUSSION... /ISSUED 756 PM CDT TUE AUG 11 2015/
DISCUSSION...CONVECTION CONTINUES TO MOVE SOUTHWESTWARD FROM
THE UPPER TEXAS COAST EARLY THIS EVENING. THIS ACTIVITY MAY
CONTINUE TO HOLD TOGETHER FOR A FEW MORE HOURS BEFORE AIR MASS
STABILIZES WITH LOSS OF DAYTIME HEATING. 23Z HRRR MODEL SHOWS
THIS POSSIBILITY. GOES SOUNDER SHOWS SUFFICIENT MOISTURE REMAINS
OVER THE VICTORIA CROSSROADS WHILE THE AIR MASS IS SLIGHTLY DRIER
OVER THE COASTAL BEND. SOME OF THESE STORMS MAY PRODUCE STRONG
GUSTY WINDS OVER THE VICTORIA CROSSROADS.
PREV DISCUSSION... /ISSUED 640 PM CDT TUE AUG 11 2015/
DISCUSSION...UPDATED FOR 00Z AVIATION.
AVIATION...WILL KEEP MAINLY VFR CONDITIONS THROUGH TONIGHT...BUT
TSRA NOTED NORTHEAST OF VCT TAF SITE. THINK THESE STORMS SHOULD
REMAIN NORTH OF THE AREA...BUT WILL MONITOR. COULD SEE A BIT OF
FOG ONCE AGAIN TOWARD SUNRISE...HAVE TEMPO MVFR GROUPS. DURING THE
DAY TOMORROW...MOST SITES REMAIN VFR. TSRA COULD APPROACH VCT SITE
DURING THE AFTERNOON...HAVE PROB30 FOR THAT SITE DURING THE DAY.
ALI AND CRP HAVE A SLIGHT CHANCE FOR CONVECTION AS WELL...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 241 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 99 77 96 77 / 10 20 20 30 10
VICTORIA 74 101 76 98 76 / 10 30 30 30 10
LAREDO 77 103 80 104 80 / 10 10 20 20 10
ALICE 74 102 76 100 76 / 10 20 20 30 10
ROCKPORT 78 96 79 93 80 / 10 30 30 30 10
COTULLA 76 104 79 103 78 / 10 20 20 20 10
KINGSVILLE 76 101 76 98 76 / 10 20 20 30 10
NAVY CORPUS 78 94 80 91 80 / 10 20 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TT/89...SHORT TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
756 PM CDT TUE AUG 11 2015
.DISCUSSION...CONVECTION CONTINUES TO MOVE SOUTHWESTWARD FROM
THE UPPER TEXAS COAST EARLY THIS EVENING. THIS ACTIVITY MAY
CONTINUE TO HOLD TOGETHER FOR A FEW MORE HOURS BEFORE AIR MASS
STABILIZES WITH LOSS OF DAYTIME HEATING. 23Z HRRR MODEL SHOWS
THIS POSSIBILITY. GOES SOUNDER SHOWS SUFFICIENT MOISTURE REMAINS
OVER THE VICTORIA CROSSROADS WHILE THE AIR MASS IS SLIGHTLY DRIER
OVER THE COASTAL BEND. SOME OF THESE STORMS MAY PRODUCE STRONG
GUSTY WINDS OVER THE VICTORIA CROSSROADS.
&&
.PREV DISCUSSION... /ISSUED 640 PM CDT TUE AUG 11 2015/
DISCUSSION...UPDATED FOR 00Z AVIATION.
AVIATION...WILL KEEP MAINLY VFR CONDITIONS THROUGH TONIGHT...BUT
TSRA NOTED NORTHEAST OF VCT TAF SITE. THINK THESE STORMS SHOULD
REMAIN NORTH OF THE AREA...BUT WILL MONITOR. COULD SEE A BIT OF
FOG ONCE AGAIN TOWARD SUNRISE...HAVE TEMPO MVFR GROUPS. DURING THE
DAY TOMORROW...MOST SITES REMAIN VFR. TSRA COULD APPROACH VCT SITE
DURING THE AFTERNOON...HAVE PROB30 FOR THAT SITE DURING THE DAY.
ALI AND CRP HAVE A SLIGHT CHANCE FOR CONVECTION AS WELL...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 241 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 99 77 96 77 / 10 20 20 30 10
VICTORIA 74 101 76 98 76 / 20 30 30 30 10
LAREDO 77 103 80 104 80 / 10 10 20 20 10
ALICE 74 102 76 100 76 / 10 20 20 30 10
ROCKPORT 78 96 79 93 80 / 20 30 30 30 10
COTULLA 76 104 79 103 78 / 10 20 20 20 10
KINGSVILLE 76 101 76 98 76 / 10 20 20 30 10
NAVY CORPUS 78 94 80 91 80 / 10 20 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TMT/89...SHORT TERM
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
755 PM CDT TUE AUG 11 2015
.UPDATE...
VERY ISOLATED SHOWERS AND STORMS CONTINUE TO BE OBSERVED FROM THE
HILL COUNTRY TO THE COASTAL PLAINS THIS EVENING. THERE IS A STRONG
MOISTURE AND INSTABILITY GRADIENT DRAPED OVER BASICALLY THE I35
CORRIDOR WHICH HAS PREVENTED MUCH ACTIVITY FROM SURVIVING BEYOND
THAT POINT. FARTHER EAST...COLD POOL DYNAMICS HAVE TAKEN OVER AND
GENERATED A SEVERE CLUSTER OF STORMS JUST EAST OF THE LAVACA
COUNTY LINE AND ARE MOVING SOUTHWEST. SHOULD MISS THE CWA MOSTLY
WITH ONLY ISOLATED STORMS PRESENT THROUGH 10 PM. THREAT CONTINUES
TO REMAIN MOSTLY GUSTY WINDS OF UP TO 40 MPH THROUGH THE MID
EVENING. QUICKLY AFTER NIGHTFALL...CONDITIONS WILL BECOME QUIETER.
UPDATED HOURLY GRIDS TO MESH WITH LATEST OBS AND POPULATED HOURLY
WIND GRIDS WITH HRRR AS IT WAS PERFORMING WELL WITH THE OUTFLOW
WINDS GENERATED BY THIS ISOLATED CONVECTION.
ALSO...THE HEAT ADVISORY WAS ALLOWED TO EXPIRE AT 8PM. UPDATED
THE PRODUCT SUITE TO REMOVE THE ADVISORY WORDING.
&&
.PREV DISCUSSION... /ISSUED 641 PM CDT TUE AUG 11 2015/
AVIATION...
ISOLD SHRA/TSRA WILL LINGER UNTIL A LITTLE AFTER SUNSET EAST OF A
KAQO TO KT20 TO KARM LINE. KAUS HAS BEST CHANCE. HOWEVER...WILL
LEAVE OUT AS PROBS LESS THAN 20. DAYTIME HEATING INTERACTING WITH
A WEAK FRONTAL ZONE AND DEEPER MOISTURE DRIFTING TO THE SOUTHWEST
WILL ALLOW ISOLD/SCT SHRA/TSRA TO DEVELOP ON WEDNESDAY. BEST
CHANCES WILL BE ALONG AND SOUTH OF A KDRT TO KBAZ TO K3T5 LINE.
WILL MENTION AT KSAT/KSSF AFTER 12/20Z AND KDRT AFTER 12/22Z WITH
PROB30S. SKIES WILL BE VFR AS BELOW 3K FT DRIES OUT AND ABOVE 3K
MOISTENS UP. THE WEAK COLD FRONT WILL DRIFT TO THE SOUTHWEST WITH
MAINLY SELY WINDS 10 KTS OR LESS SHIFTING TO MAINLY NELY.
DOWNBURST WIND GUSTS UP TO 45 KTS ARE POSSIBLE IN/NEAR SHRA/TSRA.
PREV DISCUSSION... /ISSUED 315 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
ANOTHER DAY OF ABOVE NORMAL WARMTH CONTINUES THIS AFTERNOON WITH
TEMPERATURES IN THE UPPER 90S TO NEAR 105 DEGREES ACROSS SOUTH
CENTRAL TEXAS. BASED ON RECENT OBSERVATIONS AND SHORT RANGE
GUIDANCE...WE WILL CONTINUE THE HEAT ADVISORY TODAY. THE HEAT
CONTINUES TOMORROW AND BASED ON THE LATEST GUIDANCE...WE COULD SEE A
FEW SPOTS ALONG AND EAST OF I-35 NEAR HEAT ADVISORY LEVELS DURING
THE AFTERNOON AND EARLY EVENING HOURS. FOR NOW...WILL HOLD OFF ON
EXTENDING THE ADVISORY AND AWAIT ANOTHER ROUND OR TWO OF TEMPERATURE
GUIDANCE. OTHERWISE...WE/LL MAINTAIN A VERY LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS INTO THE EARLY EVENING HOURS FOR AREAS GENERALLY
ALONG AND EAST OF A BURNET TO CUERO LINE. WE EXPECT MOST ACTIVITY
WILL BE TIED CLOSELY TO DIURNAL HEATING...SO WILL NOT MENTION ANY
RAIN CHANCES FOR TONIGHT. ON WEDNESDAY...WE EXPECT ANOTHER SHOT FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS AS THE REMNANTS OF A
WEAK COLD FRONT ALONG WITH AN INCREASE IN MID-LEVEL MOISTURE MOVES
INTO SOUTH CENTRAL TEXAS. MOISTURE LEVELS REMAIN HIGHEST ALONG AND
SOUTH OF THE THE HIGHWAY 90 CORRIDOR...SO WE/LL MENTION HIGHER
RAIN CHANCES ACROSS THIS REGION.
LONG TERM (THURSDAY THROUGH TUESDAY)...
DRIER AIR IN THE LOW-LEVELS FILTERS INTO SOUTH CENTRAL TEXAS ON
THURSDAY. THIS WILL RESULT IN MOST AREAS NORTH OF HIGHWAY 90
REMAINING DRY...WITH A 20-30% CHANCE FOR RAIN GENERALLY ALONG AND
SOUTH OF HIGHWAY 90. THE MID-LEVEL MOIST AXIS CONTINUES TO SHIFT
WESTWARD ON FRIDAY AND WE/LL ONLY MENTION ISOLATED CONVECTION
ACROSS THE SOUTHERN EDWARDS PLATEAU...WITH DRY WEATHER ELSEWHERE.
FOR THE REMAINDER OF THE FORECAST PERIOD...THE MEDIUM RANGE MODELS
CONTINUE TO SHOW A WEAK UPPER LOW/TROUGH DEVELOPING OVER THE LOWER
MS RIVER VALLEY THIS WEEKEND. THIS FEATURE IS THEN EXPECTED TO
RETROGRADE THROUGH EARLY NEXT WEEK. THE MODELS ARE SHOWING SOME
FAIRLY SIGNIFICANT DIFFERENCES WITH REGARDS TO THE STRENGTH AND
LOCATION OF THIS LOW/TROUGH. FOR NOW...WE/LL KEEP RAIN CHANCES
CONFINED TO THE COASTAL PLAINS AND LEAVE THE REMAINDER OF THE AREA
DRY. AS FOR TEMPERATURES THROUGH THE PERIOD...ABOVE NORMAL WARMTH
IS EXPECTED THROUGH SATURDAY...WITH READINGS DROPPING CLOSER TO
NORMAL FOR EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 78 102 79 101 77 / 10 20 10 - -
AUSTIN BERGSTROM INTL AIRPORT 75 102 75 100 73 / 10 20 10 10 -
NEW BRAUNFELS MUNI AIRPORT 78 103 77 101 75 / 10 30 10 10 -
BURNET MUNI AIRPORT 76 100 76 98 74 / 10 20 - 10 -
DEL RIO INTL AIRPORT 78 102 78 103 79 / 0 30 20 20 -
GEORGETOWN MUNI AIRPORT 77 101 77 99 74 / 10 10 - - -
HONDO MUNI AIRPORT 75 101 76 102 75 / - 30 20 20 -
SAN MARCOS MUNI AIRPORT 78 102 78 101 76 / 10 20 10 10 -
LA GRANGE - FAYETTE REGIONAL 78 103 77 101 75 / 10 20 10 10 -
SAN ANTONIO INTL AIRPORT 79 102 80 101 77 / 10 30 20 10 -
STINSON MUNI AIRPORT 78 102 80 102 77 / 10 30 20 20 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR THE FOLLOWING
COUNTIES: ATASCOSA...BASTROP...BEXAR...BURNET...CALDWELL...COMAL...
DE WITT...FAYETTE...GONZALES...GUADALUPE...HAYS...KARNES...LAVACA...
LEE...LLANO...TRAVIS...WILLIAMSON...WILSON.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...TB3
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
640 PM CDT TUE AUG 11 2015
.DISCUSSION...UPDATED FOR 00Z AVIATION.
&&
.AVIATION...WILL KEEP MAINLY VFR CONDITIONS THROUGH TONIGHT...BUT
TSRA NOTED NORTHEAST OF VCT TAF SITE. THINK THESE STORMS SHOULD
REMAIN NORTH OF THE AREA...BUT WILL MONITOR. COULD SEE A BIT OF
FOG ONCE AGAIN TOWARD SUNRISE...HAVE TEMPO MVFR GROUPS. DURING THE
DAY TOMORROW...MOST SITES REMAIN VFR. TSRA COULD APPROACH VCT SITE
DURING THE AFTERNOON...HAVE PROB30 FOR THAT SITE DURING THE DAY.
ALI AND CRP HAVE A SLIGHT CHANCE FOR CONVECTION AS WELL...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 241 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 76 99 77 96 77 / 10 20 20 30 10
VICTORIA 75 101 76 98 76 / 10 30 30 30 10
LAREDO 77 103 80 104 80 / 10 10 20 20 10
ALICE 75 102 76 100 76 / 10 20 20 30 10
ROCKPORT 78 96 79 93 80 / 10 30 30 30 10
COTULLA 76 104 79 103 78 / 10 20 20 20 10
KINGSVILLE 76 101 76 98 76 / 10 20 20 30 10
NAVY CORPUS 79 94 80 91 80 / 10 20 20 30 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
PZ/83...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1228 AM CDT MON AUG 10 2015
.AVIATION.../06Z TAFS/
NO CONCERNS WITH HIGH PRESSURE REMAINING IN CONTROL AT THE SURFACE
AND ALOFT. SATELLITE CURRENTLY SHOWING LOW CLOUD DEVELOPMENT OVER
THE COASTAL PLAINS. EXPECT TO SEE KSAT/KSSF BECOME MVFR 07Z-08Z.
NOT AS CONFIDENT FOR KAUS AND WILL CONTINUE WITH A TEMPO FOR MVFR
CIGS THERE. KDRT WILL ONLY SEE AN HOUR OR TWO OD SCT SO NO ISSUES.
S/SE WINDS WILL DECREASE TO NEAR 10 KNOTS AFTER 06Z. SOUTHERLY
WINDS INCREASE TO 10-15 KNOTS WITH GUSTS TO NEAR 20 KNOTS AFTER
15Z AND BECOME SELY SAME SPEEDS AFTER 21Z. LIKELY TO SEE LESS LOW
CLOUD DEVELOPMENT FOR MON NIGHT INTO TUES MORNING SO NO ISSUES FOR
THE 30 HOUR TAF SITES.
&&
.PREV DISCUSSION... /ISSUED 852 PM CDT SUN AUG 9 2015/
UPDATE... /NPW CANCELED/
ALL HEAT INDEX REPORTS IN THE AREA FELL BELOW 105 AND WELL BELOW
THE ADVISORY CRITERIA OF 108/110 DEGREES FOR EAST/WEST COUNTIES.
A SPECIAL WEATHER STATEMENT FOR THE NEXT COUPLE DAYS REPLACES THE
CANCELED HEAT ADVISORY.
PREV DISCUSSION... /ISSUED 637 PM CDT SUN AUG 9 2015/
AVIATION.../00Z TAF CYCLE/
VFR SKC ACROSS MUCH OF THE REGION WITH ONLY A FEW/SCT250 CIRRUS
CLOUDS AS OF 09/2330Z. VFR WILL CONTINUE UNTIL 09Z OR SO WITH
DEVELOPMENT OF MVFR STRATUS CLOUDS INVOF KSAT/KSSF AND KAUS THROUGH
14-15Z. HIGHEST CONFIDENCE EXISTS FOR SAT/SSF PER SOUNDING ANALYSIS
AND HRRR OUTPUT. KAUS COULD ALSO BE IMPACTED WITH BKN015 CIGS BUT
MAY BE MORE SPORADIC. KDRT SHOULD STAY VFR THROUGH THE NIGHT BUT
STRATUS WAS CLOSE BY THIS MORNING AND THIS TREND WILL NEED TO
MONITORED IN THE 06Z TAF ISSUANCE. CURRENT SURFACE WINDS OF 10-15 KT
OUT OF THE SE WILL CALM TO 5-10KT OVERNIGHT. VFR CONDITIONS WILL
PREVAIL MONDAY AFTER 15Z WITH A REPEAT OF TODAY.
PREV DISCUSSION... /ISSUED 240 PM CDT SUN AUG 9 2015/
SHORT TERM (TONIGHT THROUGH MONDAY NIGHT)...
HIGH PRESSURE RIDGE CONTINUES TO DOMINATE THIS AFTERNOON. CURRENT
HEAT ADVISORY WILL EXPIRE THIS EVENING. PEAK HEATING HAS YET TO
OCCUR BUT LOOKS LIKE A FEW SPOTS WILL HIT ADVISORY CRITERIA MAINLY
OVER THE FAR EAST...DECENT MIXING ACROSS THE REST OF THE AREA WILL
DROP DEW POINTS THROUGH THE DAY. MILD NIGHT TONIGHT WITH A REPEAT
OF STRATUS FORMATION ACROSS CENTRAL SECTIONS WITH STRONGER LOW LEVEL
SOUTHERLY FLOW. ANOTHER HOT DAY ON MONDAY BUT THE UPPER RIDGE WILL
START A WESTWARD MOVEMENT THAT WILL BRING SLIGHT ADJUSTMENTS TO POP
AND TEMPS LATER IN THE WEEK. FAIRLY LOW DEWPOINTS WILL GENERALLY
KEEP AREA HEAT INDEX VALUES JUST BELOW HEAT ADVISORY CRITERIA
LEVELS. A WEAK FRONT WILL PUSH SOUTH INTO THE RED RIVER
AREA...HELPING TO DECREASE THE GRADIENT MONDAY NIGHT AND LIMIT THE
EARLY MORNING CLOUD COVER BY TUESDAY.
LONG TERM (TUESDAY THROUGH SUNDAY)...
AS THE UPPER RIDGE SHIFTS WEST BY MID WEEK...A SIMILAR
PATTERN WILL DEVELOP LIKE THE END OF JULY. A WEAK BACKDOOR COOL
FRONT WILL PUSH INTO EAST AND NE TEXAS AS MID AND UPPER FLOW BECOMES
INCREASINGLY EASTERLY/NORTHEASTERLY. RH TIME SECTIONS SHOWS AN
INCREASE IN MID LEVEL MOISTURE STARTING LATE TUE INTO WED. THIS
MOISTURE INCREASE...ALONG WITH THE EXPECTED HOT TEMPS...SHOULD BE
ENOUGH TO FIRE UP ISOLATED/SCT CONVECTION DURING THE
AFTERNOON/EVENING HOURS ON WED AND AGAIN ON THU. LIKE THE PREVIOUS
SYSTEM ABOUT 10 DAYS AGO...STORMS COULD PRODUCE SOME STRONG
DOWNDRAFTS...WITH SEVERAL OUTFLOW BOUNDARIES LIKELY HELPING TO
INITIATE ADDITIONAL STORMS. THIS MID LEVEL MOISTURE WILL PUSH WEST
THROUGH THE WEEK...AND BY WEEKS END...POP WILL BE CONFINED TO THE
FAR WEST AND NORTHWEST.
BY THE WEEKEND AND EARLY NEXT WEEK...LONG RANGE MODELS ARE SHOWING
AN UPPER LOW OVER THE SE U.S. MOVING WEST ALONG THE NORTHERN GULF
COAST...MOVING TOWARD THE TEXAS COAST. LOWERING 500MB HEIGHTS AND
BETTER MOISTURE LEVELS WILL KEEP THE INTENSE HEAT AWAY...BUT THE
HIGHER DEWPOINTS MIGHT ACTUALLY KEEP HEAT INDEX VALUES PLENTY WARM.
CANT RULE OUT SOME CHANCES OF RAIN ESPECIALLY IN THE COASTAL PLAINS
DUE TO THE PROXIMITY OF THE UPPER LOW. THE HOPE WILL BE FOR THIS
SYSTEM AND MOISTURE TO PUSH FARTHER INLAND AND GIVE SOME RAIN
CHANCES BEYOND THE 7 DAY PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 102 78 101 77 / 0 0 0 - 10
AUSTIN BERGSTROM INTL AIRPORT 74 101 74 101 76 / 0 0 0 - 10
NEW BRAUNFELS MUNI AIRPORT 77 102 76 101 76 / 0 0 0 0 -
BURNET MUNI AIRPORT 73 101 76 101 78 / 0 0 0 - 10
DEL RIO INTL AIRPORT 77 102 77 103 78 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 75 102 77 102 79 / 0 0 0 - 10
HONDO MUNI AIRPORT 74 101 74 102 75 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 76 100 75 101 77 / 0 0 0 - -
LA GRANGE - FAYETTE REGIONAL 75 101 77 103 77 / 0 0 0 10 10
SAN ANTONIO INTL AIRPORT 78 101 77 101 78 / 0 0 0 0 -
STINSON MUNI AIRPORT 77 102 76 101 77 / 0 0 0 0 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...10
SYNOPTIC/GRIDS...04
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
659 AM EDT MON AUG 10 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTHEAST INTO THE REGION TODAY BEFORE
SLIDING TO THE NORTH LATER TONIGHT. A STRONG COLD FRONT WILL PUSH
EAST INTO THE MOUNTAINS BY EARLY TUESDAY AND ACROSS THE REMAINDER
OF THE REGION BY TUESDAY EVENING. HIGH PRESSURE BUILDS INTO THE
AREA BEHIND THE FRONT BY WEDNESDAY...BRINGING SOMEWHAT COOLER AND
DRIER AIR FOR MIDWEEK INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 AM EDT MONDAY...
CLUSTERS OF VERY SLOW MOVING SHOWERS CONTINUE TO DEVELOP EARLY THIS
MORNING ESPCLY OVER THE EAST IN ADVANCE OF A RATHER STRONG MID LEVEL
WAVE DIPPING IN FROM THE NW JUST NORTH OF THE FRONT TO THE SW. THIS
UNDERDONE BY MOST SHORT TERM MODELS INCLUDING THE HRRR SO BUMPING UP
POPS TO AT LEAST CHANCE IN PARTS OF THE EAST AND SLIGHTS OVER THE WEST
WHERE SHRA MORE SPOTTY NATURE CLOSER TO THE ACTUAL IMPULSE ALOFT.
ONCE THIS FEATURE PASSES...LOTS OF UNCERTAINTY IN REGARDS TO THE
CONVECTIVE ENVIRONMENT FROM LATE MORNING INTO THE AFTERNOON WITH A WARM
FRONT HEADING INTO THE MOUNTAINS WHILE CLOUD COVER MAY STAY RATHER
EXTENSIVE. GUIDANCE SOLUTIONS RANGE FROM THE BEST LIFT STAYING WEST OF
THE MOUNTAINS UNTIL THIS EVENING SUPPORTING ONLY SCATTERED SHRA/TSRA
BLUE RIDGE LATER...TO MORE OUTFLOW DRIVEN SUPPORT FROM THE MCS TO THE
WEST WITH THIS RESIDUAL WAVE INTERACTING WITH AT LEAST SOME HEATING
TO PRODUCE MORE MULTICELLULAR BANDS/CLUSTERS SIMILAR TO THE GFS/EC
AND NCAR ENSEMBLE. THIS ALONG THE LINGERING HIGHER 85H THETA-E RIDGE
WEST AND WHERE MODELS SUGGEST AT LEAST SOME DECENT CAPE MAY EXIST BUT
LATER. THUS TRENDED MORE ALONG THOSE LINES AND BUMPED GOING POPS TO A
PERIOD OF CATEGORICAL FAR WEST LATE AND LEFT LIKELYS IN ALL EXCEPT THE
SE WHERE MAY BE LATE OR THIS EVENING BEFORE WHATS LEFT OF WESTERN
COVERAGE MOVES EAST GIVEN WEAK STEERING. THIS COULD ALSO LEAD TO
MORE OF A HEAVY RAINFALL THREAT VS SEVERE GIVEN RATHER MEAGER FLOW
ALOFT AND LACK OF GOOD LAPSES UNLESS HEATING IS BETTER. NUDGED
HIGHS DOWN A FEW DEGREES TO ACCOUNT FOR EARLY CLOUDS/SHRA AND
POTENTIAL FOR QUICK DEVELOPMENT THIS AFTERNOON WITH ANY INSOLATION
PER PWATS OF NEARLY 2 INCHES.
GUIDANCE PUSHES A LOBE OF CONVECTION EAST/NE THIS EVENING AS THE WARM
FRONT LIFTS NORTH AND THE COLD FRONT APPROACHES FROM THE WEST LATE.
THINK BEST COVERAGE THROUGH MIDNIGHT OR SO WITH A RESIDUAL WAVE
OVERHEAD BEFORE POSSIBLY SEEING A BREAK IN ALL EXCEPT THE NORTH LATE AS
THE REGION SLIPS IN BETWEEN THE EXITING WARM FRONT AND UPSTREAM COLD
FRONT. THE COLD FRONT MAY ALSO END UP BRINGING ANOTHER BAND OF
SHRA INTO THE NW SLOPES TOWARD DAYBREAK...SO BLENDING POPS FROM
LIKELYS MOST SPOTS TO INIT...TO MAINLY CHANCE IN ALL EXCEPT THE
EAST/SE OVERNIGHT...AND OVER THE NW LATE. AGAIN MORE HEAVY RAIN
POTENTIAL BUT EXPECT SHRA/TSRA TO MOVE A BIT MORE LATE AS WESTERLY
FLOW DEEPENS SOME AHEAD OF THE COLD FRONT. STILL QUITE WARM/MUGGY
WITH LOWS UPPER 60S/LOW 70S EXCEPT MID 60S VALLEYS AND IN SPOTS
THAT RECEIVE HEAVIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
MODELS HAVE OUR NEXT COLD FRONT MOVING ACROSS THE MOUNTAINS TUESDAY
MORNING...STALLING NEAR THE BLUE RIDGE BY THE AFTERNOON. THE FRONT
WILL EVENTUALLY CLEAR THE PIEDMONT TUESDAY EVENING...WAITING ON A
SURFACE WAVE THAT WILL DEVELOP OVER THE CAROLINAS THEN MOVE OFF THE
MID ATLANTIC COAST. WE CAN NOT RULE OUT SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON...BUT THE
MAJORITY OF THE STRONGER CONVECTION WILL BE ALONG AND EAST OF HWY
29. THE COVERAGE OF STRONG STORMS FOR THE FORECAST AREA WILL DEPEND
ON THE LOCATION OF THE COLD FRONT AND THE TRACK OF THIS SURFACE
WAVE. MOST MODELS ARE KEEPING THE STRONGER CONVECTION WITH THE
SURFACE LOW OVER CENTRAL NORTH CAROLINA AND THE COASTAL PIEDMONT OF
VIRGINIA. FOR NOW...WILL KEEP CHANCE POPS ACROSS THE FORECAST AREA.
POPS WILL INCREASE IF THE FRONT REMAINS FARTHER TO THE WEST OR
LOWER/DECREASING THROUGH THE AFTERNOON IF THE FRONT PUSHES EAST OF
THE BLUE RIDGE. THE FRONT WILL BE ALONG THE CAROLINA COAST ON
WEDNESDAY. THE DEW POINT FRONT WILL CROSS OVER THE REGION BY
WEDNESDAY EVENING. WITH THE UPPER LEVEL TROUGH OVERHEAD AND
LINGERING LOW LEVEL MOISTURE WEDNESDAY...A GOOD AMOUNT OF FAIR
WEATHER CUMULUS CLOUDS WILL BE PRESENT...BUT NOT EXPECTING ANY TO
PRODUCE MEASURE RAINFALL.
TEMPERATURES ARE EXPECTED TO WARM TO NEAR NORMAL LEVELS TUESDAY.
BEHIND THE FRONT...COOLER THAN NORMAL CONDITIONS ARE EXPECTED...70S
WEST TO LOWER TO MID 80S EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
MODELS ARE ADVERTISING A RETREAT OF THE UPPER TROF OVER THE
NORTHEAST THIS TIME FRAME. THE LARGE UPPER RIDGE OVER THE CENTRAL
UNITED STATES SLIGHTLY RETROGRADES AND BUILDS NORTHEAST INTO THE
OHIO VALLEY AS A LOW CUTS OFF SOMEWHERE AROUND THE NORTHERN GULF.
AT THE SURFACE BY THURSDAY...HIGH PRESSURE WILL EXTEND FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC REGION. THIS HIGH REMAINS
OVER THE FORECAST AREA THROUGH FRIDAY. MODELS WERE BEGINNING TO
SUGGEST A WEAK LOW OR SOME LEE TROUGHING MAY DEVELOP ON THE EASTERN
SIDE OF THE APPALACHIANS ON SATURDAY. STILL NOT ENOUGH LIFT OR
MOISTURE FOR ANY SUBSTANTIAL PROBABILITY OF PRECIPITATION.
WILL BE STARTING THURSDAY MORNING WITH BELOW NORMAL MINIMUM
TEMPERATURES THEN AIR MASS GRADUALLY MODERATES THROUGH SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 645 AM EDT MONDAY...
CLUSTERS OF SHOWERS REMAIN PERSISTENT ESPCLY ACROSS THE EAST THIS
MORNING WHERE ISOLATED COVERAGE CONTINUES TO AFFECT KLYH/KDAN.
ALSO SEEING SPOTTY LIGHT SHOWERS OVER THE WEST SO WILL START OFF
WITH AT LEAST A VCSH AT MOST LOCATIONS FROM THE BLUE RIDGE EAST
EARLY ON. OTRW EXPECTING A MIX OF AC AND STRATO-CU CIGS THIS
MORNING WITH MOST OF THE VFR VARIETY EXCEPT IN THE VICINITY OF
EASTERN SHOWERS WHERE MVFR REMAINS POSSIBLE. ALSO SOME PATCHY FOG
WILL MAKE FOR LOCALIZED MVFR/IFR THROUGH MID MORNING IN THE
VALLEYS SUCH AS KLWB. ONCE THE CURRENT MID LEVEL WAVE
PASSES...EXPECTING A LULL IN SHOWERS WITH SOME IMPROVEMENT IN CIGS
BEFORE THE NEXT ROUND OF DEEPER MOISTURE ARRIVES THIS AFTERNOON.
EXTENT OF MORE ORGANIZED CONVECTION REMAINS IN QUESTION THIS
AFTERNOON WITH SOLUTIONS FOCUSING MAINLY OVER THE WEST FOR MORE
WIDESPREAD COVERAGE. THIS SHOULD ALLOW ADDED SHOWERS AND A FEW
THUNDERSTORMS TO DEVELOP OVER THE WEST TOWARD EARLY AFTERNOON AND
OUT EAST BY 20Z/4PM. THUS KEPT VCTS IN WITH MODERATE SHRA AT ALL
SITES AFTER 18Z-20Z...WITH MVFR CIGS AT ALL EXCEPT VFR AT KDAN
WHERE WILL HOLD OFF ON PRECIP. SHOWERS LIKELY TO LINGER OR
REDEVELOP OVER THE WEST AFTER THE INITIAL CONVECTION SO LEAVING IN
A MVFR MENTION INTO THE EVENING FOR ALL SITES EXCEPT OVER THE
SOUTHEAST. SHOWERS AND ADDED TSRA COULD ALSO PERSIST OVER THE
SOUTH AND WEST INTO LATER TONIGHT GIVEN OUTFLOW AND APPROACH OF
THE COLD FRONT FROM THE WEST LATE. OTRW CUTTING BACK ON ADDED SHRA
BY MIDNIGHT AT MOST LOCATIONS FOR NOW TO SEE HOW TRENDS UNFOLD
WITH RUNS LATER TODAY.
EXTENDED AVIATION DISCUSSION...
TUESDAY...SHOWERS AND STORMS INCREASE AGAIN ACROSS THE REGION
THANKS TO BOTH A FRONTAL BOUNDARY ENTERING THE REGION AND A
SHORTWAVE TROUGH PROGRESSING EASTWARD THROUGH THE OHIO VALLEY.
MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT SUB-VFR CONDITIONS WHERE
CONVECTION BECOMES MORE ORGANIZED. STRONGER STORMS WILL BE
POSSIBLE LATER TUESDAY...MAINLY ALONG AND EAST OF THE KLYH-KDAN
CORRIDOR.
BY WEDNESDAY INTO FRIDAY...ANOTHER AREA OF HIGH PRESSURE BUILDS
INTO THE REGION MAKING FOR OVERALL VFR CONDITIONS. PATCHY LATE
NIGHT AND EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG WILL AGAIN
BE POSSIBLE...THOUGH AIRMASS WILL LIKELY BE DRIER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/JM/WP
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
314 AM EDT MON AUG 10 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT SLOWLY NORTHEAST INTO THE REGION TODAY BEFORE
SLIDING TO THE NORTH LATER TONIGHT. A STRONG COLD FRONT WILL PUSH
EAST INTO THE MOUNTAINS BY EARLY TUESDAY AND ACROSS THE REMAINDER
OF THE REGION BY TUESDAY EVENING. HIGH PRESSURE BUILDS INTO THE
AREA BEHIND THE FRONT BY WEDNESDAY...BRINGING SOMEWHAT COOLER AND
DRIER AIR FOR MIDWEEK INTO THE UPCOMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 220 AM EDT MONDAY...
CLUSTERS OF VERY SLOW MOVING SHOWERS CONTINUE TO DEVELOP EARLY THIS
MORNING ESPCLY OVER THE EAST IN ADVANCE OF A RATHER STRONG MID LEVEL
WAVE DIPPING IN FROM THE NW JUST NORTH OF THE FRONT TO THE SW. THIS
UNDERDONE BY MOST SHORT TERM MODELS INCLUDING THE HRRR SO BUMPING UP
POPS TO AT LEAST CHANCE IN PARTS OF THE EAST AND SLIGHTS OVER THE WEST
WHERE SHRA MORE SPOTTY NATURE CLOSER TO THE ACTUAL IMPULSE ALOFT.
ONCE THIS FEATURE PASSES...LOTS OF UNCERTAINTY IN REGARDS TO THE
CONVECTIVE ENVIRONMENT FROM LATE MORNING INTO THE AFTERNOON WITH A WARM
FRONT HEADING INTO THE MOUNTAINS WHILE CLOUD COVER MAY STAY RATHER
EXTENSIVE. GUIDANCE SOLUTIONS RANGE FROM THE BEST LIFT STAYING WEST OF
THE MOUNTAINS UNTIL THIS EVENING SUPPORTING ONLY SCATTERED SHRA/TSRA
BLUE RIDGE LATER...TO MORE OUTFLOW DRIVEN SUPPORT FROM THE MCS TO THE
WEST WITH THIS RESIDUAL WAVE INTERACTING WITH AT LEAST SOME HEATING
TO PRODUCE MORE MULTICELLULAR BANDS/CLUSTERS SIMILAR TO THE GFS/EC
AND NCAR ENSEMBLE. THIS ALONG THE LINGERING HIGHER 85H THETA-E RIDGE
WEST AND WHERE MODELS SUGGEST AT LEAST SOME DECENT CAPE MAY EXIST BUT
LATER. THUS TRENDED MORE ALONG THOSE LINES AND BUMPED GOING POPS TO A
PERIOD OF CATEGORICAL FAR WEST LATE AND LEFT LIKELYS IN ALL EXCEPT THE
SE WHERE MAY BE LATE OR THIS EVENING BEFORE WHATS LEFT OF WESTERN
COVERAGE MOVES EAST GIVEN WEAK STEERING. THIS COULD ALSO LEAD TO
MORE OF A HEAVY RAINFALL THREAT VS SEVERE GIVEN RATHER MEAGER FLOW
ALOFT AND LACK OF GOOD LAPSES UNLESS HEATING IS BETTER. NUDGED
HIGHS DOWN A FEW DEGREES TO ACCOUNT FOR EARLY CLOUDS/SHRA AND
POTENTIAL FOR QUICK DEVELOPMENT THIS AFTERNOON WITH ANY INSOLATION
PER PWATS OF NEARLY 2 INCHES.
GUIDANCE PUSHES A LOBE OF CONVECTION EAST/NE THIS EVENING AS THE WARM
FRONT LIFTS NORTH AND THE COLD FRONT APPROACHES FROM THE WEST LATE.
THINK BEST COVERAGE THROUGH MIDNIGHT OR SO WITH A RESIDUAL WAVE
OVERHEAD BEFORE POSSIBLY SEEING A BREAK IN ALL EXCEPT THE NORTH LATE AS
THE REGION SLIPS IN BETWEEN THE EXITING WARM FRONT AND UPSTREAM COLD
FRONT. THE COLD FRONT MAY ALSO END UP BRINGING ANOTHER BAND OF
SHRA INTO THE NW SLOPES TOWARD DAYBREAK...SO BLENDING POPS FROM
LIKELYS MOST SPOTS TO INIT...TO MAINLY CHANCE IN ALL EXCEPT THE
EAST/SE OVERNIGHT...AND OVER THE NW LATE. AGAIN MORE HEAVY RAIN
POTENTIAL BUT EXPECT SHRA/TSRA TO MOVE A BIT MORE LATE AS WESTERLY
FLOW DEEPENS SOME AHEAD OF THE COLD FRONT. STILL QUITE WARM/MUGGY
WITH LOWS UPPER 60S/LOW 70S EXCEPT MID 60S VALLEYS AND IN SPOTS
THAT RECEIVE HEAVIER RAINFALL.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 AM EDT MONDAY...
MODELS HAVE OUR NEXT COLD FRONT MOVING ACROSS THE MOUNTAINS TUESDAY
MORNING...STALLING NEAR THE BLUE RIDGE BY THE AFTERNOON. THE FRONT
WILL EVENTUALLY CLEAR THE PIEDMONT TUESDAY EVENING...WAITING ON A
SURFACE WAVE THAT WILL DEVELOP OVER THE CAROLINAS THEN MOVE OFF THE
MID ATLANTIC COAST. WE CAN NOT RULE OUT SCATTERED SHOWERS AND
THUNDERSTORMS OVER THE MOUNTAINS TUESDAY AFTERNOON...BUT THE
MAJORITY OF THE STRONGER CONVECTION WILL BE ALONG AND EAST OF HWY
29. THE COVERAGE OF STRONG STORMS FOR THE FORECAST AREA WILL DEPEND
ON THE LOCATION OF THE COLD FRONT AND THE TRACK OF THIS SURFACE
WAVE. MOST MODELS ARE KEEPING THE STRONGER CONVECTION WITH THE
SURFACE LOW OVER CENTRAL NORTH CAROLINA AND THE COASTAL PIEDMONT OF
VIRGINIA. FOR NOW...WILL KEEP CHANCE POPS ACROSS THE FORECAST AREA.
POPS WILL INCREASE IF THE FRONT REMAINS FARTHER TO THE WEST OR
LOWER/DECREASING THROUGH THE AFTERNOON IF THE FRONT PUSHES EAST OF
THE BLUE RIDGE. THE FRONT WILL BE ALONG THE CAROLINA COAST ON
WEDNESDAY. THE DEW POINT FRONT WILL CROSS OVER THE REGION BY
WEDNESDAY EVENING. WITH THE UPPER LEVEL TROUGH OVERHEAD AND
LINGERING LOW LEVEL MOISTURE WEDNESDAY...A GOOD AMOUNT OF FAIR
WEATHER CUMULUS CLOUDS WILL BE PRESENT...BUT NOT EXPECTING ANY TO
PRODUCE MEASURE RAINFALL.
TEMPERATURES ARE EXPECTED TO WARM TO NEAR NORMAL LEVELS TUESDAY.
BEHIND THE FRONT...COOLER THAN NORMAL CONDITIONS ARE EXPECTED...70S
WEST TO LOWER TO MID 80S EAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...
MODELS ARE ADVERTISING A RETREAT OF THE UPPER TROF OVER THE
NORTHEAST THIS TIME FRAME. THE LARGE UPPER RIDGE OVER THE CENTRAL
UNITED STATES SLIGHTLY RETROGRADES AND BUILDS NORTHEAST INTO THE
OHIO VALLEY AS A LOW CUTS OFF SOMEWHERE AROUND THE NORTHERN GULF.
AT THE SURFACE BY THURSDAY...HIGH PRESSURE WILL EXTEND FROM THE MID
MISSISSIPPI VALLEY TO THE MID ATLANTIC REGION. THIS HIGH REMAINS
OVER THE FORECAST AREA THROUGH FRIDAY. MODELS WERE BEGINNING TO
SUGGEST A WEAK LOW OR SOME LEE TROUGHING MAY DEVELOP ON THE EASTERN
SIDE OF THE APPALACHIANS ON SATURDAY. STILL NOT ENOUGH LIFT OR
MOISTURE FOR ANY SUBSTANTIAL PROBABILITY OF PRECIPITATION.
WILL BE STARTING THURSDAY MORNING WITH BELOW NORMAL MINIMUM
TEMPERATURES THEN AIR MASS GRADUALLY MODERATES THROUGH SUNDAY.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
AS OF 1245 AM EDT MONDAY...
STILL SEEING ISOLATED SLOW MOVING SHOWERS AROUND THE KLYH VICINITY
AND EXPECT THESE TO LINGER A WHILE LONGER BEFORE PUSHING EAST AND
WEAKENING WELL BEFORE DAYBREAK. THIS MAY BRING A PERIOD OF LOWER
MVFR VSBY IN SHRA FOR KLYH OVER THE NEXT COUPLE OF HOURS ALONG
WITH A MVFR CIG. OTRW EXPECTING ONLY ISOLATED ADDED SHOWER
COVERAGE OVERNIGHT WITH LOTS OF STRATO-CU/AC PUSHING IN FROM THE
NW AHEAD OF A WARM FRONT TO THE WEST. MODELS CONTINUE TO BRING A
LOW END VFR/HIGH END MVFR CIGS OVER MOST OF THE AREA...SO TWEAKED
CIGS DOWN IN SPOTS BUT NOT AS LOW AS CURRENT GUIDANCE. THUS WILL
LEAN TOWARD VFR THROUGH MOST OF THE OVERNIGHT BUT SEEING SOME FOG
POTENTIAL AT KBLF/KLWB/KBCB AS WELL AS KLYH IN THE PRE DAWN HOURS
WHEN PERIODS OF IFR/MVFR COULD DEVELOP IF CLOUDS ARE LESS.
BASED ON FORECAST CONSENSUS SHOULD SEE VFR TO MVFR CIGS MONDAY
MORNING WITH SHOWERS AND A FEW THUNDERSTORMS ARRIVING INTO THE
WEST TOWARD MIDDAY/18Z AND EAST BY 20Z. KEPT VCTS IN WITH MODERATE
SHRA AT ALL SITES AFTER 18Z-20Z...WITH MVFR CIGS AT ALL EXCEPT VFR
AT KDAN WHERE WILL HOLD OFF ON PRECIP. SHOWERS LIKELY TO LINGER OR
REDEVELOP OVER THE WEST AFTER THE INITIAL CONVECTION SO LEAVING IN
A MVFR MENTION INTO THE EVENING FOR ALL SITES EXCEPT OVER THE
SOUTHEAST. SHOWERS AND ADDED TSRA COULD ALSO PERSIST OVER THE
SOUTH AND WEST INTO LATER MONDAY NIGHT GIVEN OUTFLOW AND APPROACH
OF THE COLD FRONT FROM THE WEST LATE. OTRW CUTTING BACK ON ADDED
SHRA BY MIDNIGHT AT MOST LOCATIONS FOR NOW TO SEE HOW TRENDS
UNFOLD LATER ON.
EXTENDED AVIATION DISCUSSION...
TUESDAY...SHOWERS AND STORMS INCREASE AGAIN ACROSS THE REGION
THANKS TO BOTH A FRONTAL BOUNDARY ENTERING THE REGION AND A
SHORTWAVE TROUGH PROGRESSING EASTWARD THROUGH THE OHIO VALLEY.
MAINLY VFR CONDITIONS ARE EXPECTED EXCEPT SUB-VFR CONDITIONS WHERE
CONVECTION BECOMES MORE ORGANIZED. STRONGER STORMS WILL BE
POSSIBLE LATER TUESDAY...MAINLY ALONG AND EAST OF THE KLYH-KDAN
CORRIDOR.
BY WEDNESDAY INTO FRIDAY...ANOTHER AREA OF HIGH PRESSURE BUILDS
INTO THE REGION MAKING FOR OVERALL VFR CONDITIONS. PATCHY LATE
NIGHT AND EARLY MORNING MOUNTAIN AND RIVER VALLEY FOG WILL AGAIN
BE POSSIBLE...THOUGH AIRMASS WILL LIKELY BE DRIER.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...DS/JH
NEAR TERM...JH
SHORT TERM...RCS
LONG TERM...AMS
AVIATION...DS/JH/JM/WP
AREA FORECAST DISCUSSION
NWS PORTLAND OR
310 PM PDT MON AUG 10 2015
.SYNOPSIS...AN OFFSHORE LOW PRESSURE SYSTEM CENTERED NEAR 45N/130W
WILL CONTINUE MOVING SOUTHWARD OFF THE COAST...REACHING WEST OF THE
NORTHERN CALIFORNIA COAST TOMORROW AND WEDNESDAY. RESULTING SOUTHERLY
FLOW ALOFT IS BRINGING MOISTURE AND INSTABILITY INTO THE REGION AND
WILL KEEP SHOWER AND THUNDERSTORM CHANCES AROUND FOR THE NEXT FEW
DAYS. THE LOW WILL LIFT OUT TO THE NORTHEAST AND THROUGH THE PACIFIC
NORTHWEST ON THURSDAY AND FRIDAY. THE BEST CHANCE OF MORE WIDESPREAD
SHOWERS OR THUNDERSTORMS IS LATER THURSDAY INTO FRIDAY AS THE LOW
MOVES ONSHORE AND INLAND. WARMER AND DRY WEATHER IS EXPECTED TO
RETURN NEXT WEEKEND.
&&
.SHORT TERM...TODAY THROUGH THURSDAY...A SLOW MOVING OFFSHORE CLOSED
LOW IS CURRENTLY CENTERED AROUND 45N/130W. AN ASSOCIATED WEAK FRONTAL
BOUNDARY HAS BEEN JUST OFFSHORE TODAY...AND EVEN BROUGHT SOME WEAK
SHOWERS ONTO THE N OREGON AND S WASHINGTON COAST THIS MORNING. THERE
HAVE BEEN SOME DECENT ECHOES ON RADAR INDICATING THAT SOME SHOWERS
HAVE BEEN OCCURRING OVER THE COASTAL WATERS FOR MUCH OF THE DAY...BUT
DO NOT EXPECT THE FRONT TO HAVE ANY EFFECT ONSHORE GOING FORWARD. THE
POSITIONING OF THE UPPER LOW IS RESULTING IN SOUTHERLY FLOW ALOFT
OVER THE PAC NW...WHICH IS SPREADING MID LEVEL MOISTURE AND AN
UNSTABLE AIR MASS INTO THE REGION. FCST MODEL SOUNDINGS INDICATED A
DECENT CAP TO CONVECTION TODAY...BUT IT APPEARS THAT WE HAVE BROKEN
THE CAP. SURFACE BASED CONVECTIVE ACTIVITY IS STARTING TO OCCUR ALONG
AND EAST OF THE OREGON CASCADE CREST. BASED ON THE LATEST SHORT TERM
MODELS...EXPECT THAT THE CONVECTION WILL BECOME MORE VIGOROUS OVER
THE NEXT FEW HOURS IN THE CASCADES. SPC MESOSCALE ANALYSIS IS
INDICATING 0 TO 6 KM BULK SHEAR VALUES OF AROUND 40 KT OVER THE
REGION...WHICH WOULD SUGGEST THAT WE HAVE A BETTER THAN NORMAL CHANCE
OF SEEING SOME STRONGER AND LONGER LIVED CELLS FORMING LATER THIS
AFTERNOON. SSW FLOW ALOFT SHOULD STEER STORMS INTO THE
FOOTHILLS...AND POTENTIALLY INTO THE INTERIOR LOWLANDS AND COAST
RANGE LATER THIS AFTERNOON AND THIS EVENING.
ALTHOUGH THE CONVECTION TODAY IS SURFACE BASED...A FEW THUNDERSTORMS
MAY LINGER INTO THE OVERNIGHT PERIOD AS THERE IS SOME DECENT MID
LEVEL INSTABILITY IN PLACE. THERE WILL ALSO BE A WEAK SHORTWAVE
MOVING ONSHORE AND WE WILL BE NEAR THE LEFT EXIT REGION OF AN 80 KT
JET CORE. THINK THE BEST THUNDER CHANCES OVERNIGHT WILL BE OVER THE
CENTRAL OREGON COAST AND COAST RANGE NEAREST TO THE JET EXIT REGION.
THEN TOMORROW WILL LIKELY BE A NEAR REPEAT OF TODAY...ASSUMING WE
DON/T HAVE TOO MUCH CONVECTIVE DEBRIS CLOUD COVER. THE SOUTHERLY MID
LEVEL FLOW IS MODELED TO HAVE A BIT MORE OF AN EASTERLY COMPONENT TO
IT...SO THINK THE CHANCES OF GETTING SOME STORMS INTO THE VALLEY AND
COAST RANGE WILL BE HIGHER TOMORROW THAN TODAY.
THE UPPER LOW WILL BEGIN TO SLOWLY DRIFT NORTHEAST ON WED. EXPECT
THAT THERE WILL STILL BE SOME THUNDERSTORM POTENTIAL...GIVEN THAT THE
LOW REMAINS TO OUR SW...BUT THE FCST MODELS ARE NOT INDICATING AS
MUCH INSTABILITY AND THERE IS NO REAL TRIGGER FOR CONVECTION. SO FOR
NOW WILL LIMIT THE THUNDERSTORM CHANCES TO THE CASCADES. THE APPROACH
OF THE LOW WILL ALSO START TO INCREASE THE LOW LEVEL ONSHORE
FLOW...STARTING A GENERAL COOLING TREND AND INCREASING THE MARINE
INFLUENCE OVER THE INTERIOR.
THE LOW WILL BEGIN TO PUSH ONSHORE THU. EXPECT THIS WILL BE THE BEST
CHANCE FOR MORE WIDESPREAD PRECIPITATION ACROSS THE REGION AS THE
COLD POOL ALOFT ASSOCIATED WITH THE LOW CENTER DESTABILIZES THE
ATMOSPHERE FURTHER. WILL MAINTAIN A SLIGHT CHANCE FOR THUNDERSTORMS
DURING THE DAY THU EAST OF THE COAST RANGE...BUT THINK THE BEST
CHANCE WILL BE OVER THE CASCADES. HOWEVER...THERE SHOULD BE QUITE A
BIT OF SHOWER ACTIVITY ACROSS THE ENTIRE REGION. THE ONSHORE FLOW
WILL STRENGTHEN EVEN MORE THU...LIKELY BRINGING TEMPS OVER THE
INTERIOR LOWLANDS DOWN INTO THE UPPER 70S. PYLE
.LONG TERM...THE UPPER LEVEL LOW WILL CONTINUE TO MOVE ACROSS THE
FORECAST AREA THROUGH FRIDAY. AN INCREASE IN INSTABILITY WILL BRING
A GREATER CHANCE OF SHOWERS...WITH A SLIGHT CHANCE OF THUNDERSTORMS
EAST OF THE COAST RANGE LATE THURSDAY. THUNDERSTORMS SHOULD BECOME
MORE CONFIDED TO THE CASCADES FRIDAY. WIDESPREAD CLOUDS AND MUCH
COOLER TEMPERATURES ARE ALSO EXPECTED FRIDAY AS MARINE AIR RETURNS
TO THE REGION. MODELS CONTINUE TO SUGGEST DRIER AND SLIGHTLY WARMER
WEATHER THROUGH THE WEEKEND...BEFORE ANOTHER TROUGH APPROACHES FROM
THE NORTHWEST EARLY NEXT WEEK. HOWEVER...DUE TO DIFFERENCES IN THE
MODELS WILL CONTINUE WITH THE CURRENT TREND OF DRYING AND WARMING
FOR NOW. /64
&&
.AVIATION...VFR CONDITIONS CONTINUE ACROSS THE INTERIOR TODAY WITH
ONLY SCATTERED MID/HIGH CLOUDS. MEANWHILE VFR CIGS HAVE PERSISTED
ALONG THE COAST...WITH LOCAL IFR AROUND KONP...IN THE WEAKLY
ONSHORE LOW LEVEL FLOW. WILL SEE ADDITIONAL CUMULUS DEVELOPMENT
OVER THE COAST RANGE AND CASCADES THIS AFTERNOON AND ADDITIONAL
MID CLOUDS MOVING INTO THE REGION FROM S TO N. HOWEVER...INLAND
CIGS SHOULD REMAIN VFR WITH THE POSSIBLE EXCEPTION OF TEMPORARY
CIG/VSBY REDUCTIONS IN ANY DEVELOPING SHRA/TSRA. BEST CHANCES
REMAIN IN THE 00Z-06Z TIME FRAME. WITH ONSHORE LOW-LEVEL FLOW
OVERNIGHT...EXPECT A RETURN OF MARINE STRATUS TO THE COAST AFT 09Z
WITH A CHANCE OF A WEAK PUSH ALONG THE COLUMBIA TO AROUND KKLS OR
PERHAPS EVEN THE METRO PORTLAND TERMINALS BY AROUND DAYBREAK.
KPDX AND APPROACHES...VFR CONTINUES THIS AFTERNOON WITH
INCREASING CUMULUS DEVELOPING. MAY SEE ISOLATED TSRA/SHRA
FORM...GENERALLY BETWEEN 01Z AND 06Z TUE...BUT BEST CHANCES
REMAIN WELL E OF TERMINAL IN CASCADES AND FOOTHILLS. DUE TO THIS
CONTINUED LOWER CONFIDENCE...WILL MAINTAIN VCSH IN TAF THROUGH
THIS PERIOD AND PROACTIVELY AMEND AS NEEDED. CULLEN
&&
.MARINE...OVERALL NOT MUCH CHANGE TO THE FORECAST THROUGH THE
WEEK WITH WINDS AND WAVES REMAINING BELOW ABOUT 15 KTS AND AROUND
4 FT RESPECTIVELY. THE SURFACE LOW CURRENTLY SITS AROUND 250 NM W
OF CANNON BEACH AND WILL SLOWLY DRIFT S ACROSS THE REGION THROUGH
MIDWEEK. MODELS SUGGEST WINDS WILL BECOME N ON TUE AND BECOME A
BIT GUSTY IN THE NORTHERN ZONES. INCREASED FORECAST TO REFLECT
GUSTS TO AROUND 20 KT...BUT WILL LET FUTURE SHIFT EVALUATE
ANOTHER MODEL RUN TO SEE IF AN ADVISORY MAY BE NEEDED. WINDS THEN
RETURN SOUTHERLY ON WED WITH GUSTS 15 TO 20 KT. SURFACE HIGH
PRESSURE BUILDS WELL OFFSHORE OVER THE PACIFIC THROUGH THE WEEK
AND WILL PUSH INTO THE COASTAL WATERS LATE IN THE WEEK AND
ESPECIALLY THIS WEEKEND. THIS WILL BRING A BETTER CHANCE FOR SMALL
CRAFT ADVISORY STRENGTH WINDS AS THERMAL LOW PRESSURE STRENGTHENS
ALONG THE N CALIFORNIA/S OREGON COAST. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM NOON TODAY TO 11 PM PDT TUESDAY FOR
CENTRAL OREGON CASCADE FOOTHILLS-MT. HOOD NATIONAL FOREST
WEST OF CASCADE CREST-NORTH OREGON CASCADE FOOTHILLS-
WILLAMETTE NATIONAL FOREST.
WA...RED FLAG WARNING FROM NOON TODAY TO 11 PM PDT TUESDAY FOR
EXTREME SOUTH WASHINGTON CASCADES AND FOOTHILLS.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
217 PM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Blue Mountains and Camas
Prairie and spreading across extreme eastern Washington and north
Idaho. A few record high temperatures may be set Wednesday with a
isolated mountain thunderstorms possible. A cold front late Thursday
will bring another round of potentially strong thunderstorms.
Breezy and cooler conditions are expected by Friday and into the
upcoming weekend.
&&
.DISCUSSION...
ACTIVE AND UNSETTLED WEATHER EXPECTED THIS WEEK FEATURING HOT
CONDITIONS...THUNDERSTORMS AND POTENTIALLY GUSTY WINDS.
Tonight through Thursday night...A very active weather period
fraught with potential hazards for multiple interested parties is
shaping up through the short term. The deep closed upper low
pressure visible on satellite circulating off the Oregon coast is
the main offender.
First...for tonight this low has spawned a short wave disturbance
on it`s east flank southerly flow migrating through Oregon this
afternoon which is triggering thunderstorms upstream from the
forecast area. The pattern for tonight is conducive for these
storms to spit out a gust front moving from south to north through
the eastern and possibly central Columbia Basin late this
afternoon through this evening. This is not a sure bet but the
threat is high enough based on previous case histories and
supported by some fine scale models to warrant mention of gusty
winds and blowing dust across the eastern basin this evening. The
unstable moist air mass over the forecast area will also be ripe
for lifting by this gust front and the dynamic support from the
parent short wave into isolated to scattered thunderstorms across
the eastern half of the forecast area tonight...mandating a Red
Flag Warning for abundant lightning. Other than the potential
evening unpleasantness the late overnight period will be
uneventful but warm.
Tuesday and Wednesday feature the forecast area stuck under warm
southerly flow as the upper low remains largely stationary off
the coast. Other than another weak wave marginally detectable on
the GFS model due through the panhandle Wednesday
morning...thunderstorms will be largely confined to the mountains
ringing the Columbia Basin during the afternoons and evenings.
The big story of this period will be hot temperatures and sultry
overnight lows with generally light and terrain driven winds as a
strong surface thermal trough remains entrenched in the basin.
Thursday is the next potentially hazardous weather day. Models are
in good agreement and consistent in finally ejecting the upper low
inland...through the forecast area...Thursday night. After a few
days of sweltering temperatures the stage will be set for an
outbreak of thunderstorms...not just on the mountains but
everywhere...as the trough produces dynamic support aloft and a
strong cold front at the surface. These storms will probably begin
popping up during the day...isolated in the basin and scattered
over the mountains...as the trough approaches. Timing will be
critical as far as severe potential is concerned. A late
afternoon/evening arrival of the cold front will bear damaging
winds...blowing dust haboobs...organized lines of severe
thunderstorms and all manner of associated ugliness. A late
evening or overnight passage will be less vicious and probably
consist of scattered more garden variety thunderstorms and rain
showers with localized gusts followed by breezy to windy
conditions into Friday morning. This uncertainty forecast will be
refined and nailed down in the coming days as the "whites of the
eyes" become visible. /Fugazzi
Friday through Monday: A change to cooler and drier weather can be
expected for the upcoming weekend. After the strong cold front
pushes through late Thursday, the upper level low wobbles its way
across the northern Cascades and along the Canadian border Friday
and Friday night. This feature will enhance convection, continuing
the threat of showers with embedded thunderstorms as the cold pool
aloft swings through the region. Breezy winds can be expected on
Friday with sustained speeds of 15 to 25 mph from the Cascades and
across the Columbia Basin with gusts of 30-40 mph. The winds will
be in response to the substantial cooling expected Friday by 15
to 20 degrees. After a short heatwave, daytime temperatures Friday
will be stuck in the 70s. The upper level low will depart the
region by Saturday, leaving a flat ridge dominated by a westerly
flow aloft through the weekend with dry conditions and
temperatures moderating toward normal. Winds will be lighter but
occasional afternoon gusts are possible. The GFS and ECWMF show
the flat ridge buckling by Monday as another upper level low drops
down from BC and sits along the Canadian border. This will bring
another chance of showers to the northern mountains, slightly
cooler temperatures and locally breezy winds for Monday. /rfox.
&&
.AVIATION...
18Z TAFS: The timing of the shortwave seems to have slowed a bit
by a couple hours and have slowed the time of the convection.
Currently high clouds are pushing across the eastern TAF sites,
while mostly clear skies found across the Cascades and western
Basin. The atmosphere become increasingly unstable at this time
with scattered thunderstorms across much of extreme eastern WA and
into the ID panhandle. The focus of this thunderstorm activity is
expected to remain east of a line from KMWH to KOMK. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening
continues to be moderate. Expect a rapid transition to VFR
conditions behind this shortwave overnight into Tues AM. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 95 66 99 69 95 / 50 10 20 10 10 20
Coeur d`Alene 59 97 63 98 65 94 / 50 10 20 20 10 20
Pullman 55 97 60 98 63 93 / 60 10 20 10 10 20
Lewiston 65 104 69 105 71 100 / 50 10 20 10 10 30
Colville 60 99 59 102 59 99 / 30 20 10 10 10 20
Sandpoint 54 95 59 97 57 93 / 50 10 20 10 10 20
Kellogg 56 97 60 98 63 93 / 60 10 20 20 10 30
Moses Lake 63 100 64 102 66 96 / 40 10 10 0 0 20
Wenatchee 72 99 70 102 75 93 / 20 10 10 10 0 20
Omak 66 100 66 103 67 98 / 20 20 10 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 11 PM PDT this evening for Northern and
Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning until 11 PM PDT this evening for East
Washington Palouse and Spokane Area (Zone 674).
Red Flag Warning from 6 PM this evening to 2 AM PDT Tuesday for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
Red Flag Warning from 6 PM to 11 PM PDT this evening for East
Washington Northeast (Zone 686).
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
217 PM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Blue Mountains and Camas
Prairie and spreading across extreme eastern Washington and north
Idaho. A few record high temperatures may be set Wednesday with a
isolated mountain thunderstorms possible. A cold front late Thursday
will bring another round of potentially strong thunderstorms.
Breezy and cooler conditions are expected by Friday and into the
upcoming weekend.
&&
.DISCUSSION...
ACTIVE AND UNSETTLED WEATHER EXPECTED THIS WEEK FEATURING HOT
CONDITIONS...THUNDERSTORMS AND POTENTIALLY GUSTY WINDS.
Tonight through Thursday night...A very active weather period
fraught with potential hazards for multiple interested parties is
shaping up through the short term. The deep closed upper low
pressure visible on satellite circulating off the Oregon coast is
the main offender.
First...for tonight this low has spawned a short wave disturbance
on it`s east flank southerly flow migrating through Oregon this
afternoon which is triggering thunderstorms upstream from the
forecast area. The pattern for tonight is conducive for these
storms to spit out a gust front moving from south to north through
the eastern and possibly central Columbia Basin late this
afternoon through this evening. This is not a sure bet but the
threat is high enough based on previous case histories and
supported by some fine scale models to warrant mention of gusty
winds and blowing dust across the eastern basin this evening. The
unstable moist air mass over the forecast area will also be ripe
for lifting by this gust front and the dynamic support from the
parent short wave into isolated to scattered thunderstorms across
the eastern half of the forecast area tonight...mandating a Red
Flag Warning for abundant lightning. Other than the potential
evening unpleasantness the late overnight period will be
uneventful but warm.
Tuesday and Wednesday feature the forecast area stuck under warm
southerly flow as the upper low remains largely stationary off
the coast. Other than another weak wave marginally detectable on
the GFS model due through the panhandle Wednesday
morning...thunderstorms will be largely confined to the mountains
ringing the Columbia Basin during the afternoons and evenings.
The big story of this period will be hot temperatures and sultry
overnight lows with generally light and terrain driven winds as a
strong surface thermal trough remains entrenched in the basin.
Thursday is the next potentially hazardous weather day. Models are
in good agreement and consistent in finally ejecting the upper low
inland...through the forecast area...Thursday night. After a few
days of sweltering temperatures the stage will be set for an
outbreak of thunderstorms...not just on the mountains but
everywhere...as the trough produces dynamic support aloft and a
strong cold front at the surface. These storms will probably begin
popping up during the day...isolated in the basin and scattered
over the mountains...as the trough approaches. Timing will be
critical as far as severe potential is concerned. A late
afternoon/evening arrival of the cold front will bear damaging
winds...blowing dust haboobs...organized lines of severe
thunderstorms and all manner of associated ugliness. A late
evening or overnight passage will be less vicious and probably
consist of scattered more garden variety thunderstorms and rain
showers with localized gusts followed by breezy to windy
conditions into Friday morning. This uncertainty forecast will be
refined and nailed down in the coming days as the "whites of the
eyes" become visible. /Fugazzi
Friday through Monday: A change to cooler and drier weather can be
expected for the upcoming weekend. After the strong cold front
pushes through late Thursday, the upper level low wobbles its way
across the northern Cascades and along the Canadian border Friday
and Friday night. This feature will enhance convection, continuing
the threat of showers with embedded thunderstorms as the cold pool
aloft swings through the region. Breezy winds can be expected on
Friday with sustained speeds of 15 to 25 mph from the Cascades and
across the Columbia Basin with gusts of 30-40 mph. The winds will
be in response to the substantial cooling expected Friday by 15
to 20 degrees. After a short heatwave, daytime temperatures Friday
will be stuck in the 70s. The upper level low will depart the
region by Saturday, leaving a flat ridge dominated by a westerly
flow aloft through the weekend with dry conditions and
temperatures moderating toward normal. Winds will be lighter but
occasional afternoon gusts are possible. The GFS and ECWMF show
the flat ridge buckling by Monday as another upper level low drops
down from BC and sits along the Canadian border. This will bring
another chance of showers to the northern mountains, slightly
cooler temperatures and locally breezy winds for Monday. /rfox.
&&
.AVIATION...
18Z TAFS: The timing of the shortwave seems to have slowed a bit
by a couple hours and have slowed the time of the convection.
Currently high clouds are pushing across the eastern TAF sites,
while mostly clear skies found across the Cascades and western
Basin. The atmosphere become increasingly unstable at this time
with scattered thunderstorms across much of extreme eastern WA and
into the ID panhandle. The focus of this thunderstorm activity is
expected to remain east of a line from KMWH to KOMK. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening
continues to be moderate. Expect a rapid transition to VFR
conditions behind this shortwave overnight into Tues AM. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 95 66 99 69 95 / 50 10 20 10 10 20
Coeur d`Alene 59 97 63 98 65 94 / 50 10 20 20 10 20
Pullman 55 97 60 98 63 93 / 60 10 20 10 10 20
Lewiston 65 104 69 105 71 100 / 50 10 20 10 10 30
Colville 60 99 59 102 59 99 / 30 20 10 10 10 20
Sandpoint 54 95 59 97 57 93 / 50 10 20 10 10 20
Kellogg 56 97 60 98 63 93 / 60 10 20 20 10 30
Moses Lake 63 100 64 102 66 96 / 40 10 10 0 0 20
Wenatchee 72 99 70 102 75 93 / 20 10 10 10 0 20
Omak 66 100 66 103 67 98 / 20 20 10 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 11 PM PDT this evening for Northern and
Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning until 11 PM PDT this evening for East
Washington Palouse and Spokane Area (Zone 674).
Red Flag Warning from 6 PM this evening to 2 AM PDT Tuesday for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
Red Flag Warning from 6 PM to 11 PM PDT this evening for East
Washington Northeast (Zone 686).
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
217 PM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Blue Mountains and Camas
Prairie and spreading across extreme eastern Washington and north
Idaho. A few record high temperatures may be set Wednesday with a
isolated mountain thunderstorms possible. A cold front late Thursday
will bring another round of potentially strong thunderstorms.
Breezy and cooler conditions are expected by Friday and into the
upcoming weekend.
&&
.DISCUSSION...
ACTIVE AND UNSETTLED WEATHER EXPECTED THIS WEEK FEATURING HOT
CONDITIONS...THUNDERSTORMS AND POTENTIALLY GUSTY WINDS.
Tonight through Thursday night...A very active weather period
fraught with potential hazards for multiple interested parties is
shaping up through the short term. The deep closed upper low
pressure visible on satellite circulating off the Oregon coast is
the main offender.
First...for tonight this low has spawned a short wave disturbance
on it`s east flank southerly flow migrating through Oregon this
afternoon which is triggering thunderstorms upstream from the
forecast area. The pattern for tonight is conducive for these
storms to spit out a gust front moving from south to north through
the eastern and possibly central Columbia Basin late this
afternoon through this evening. This is not a sure bet but the
threat is high enough based on previous case histories and
supported by some fine scale models to warrant mention of gusty
winds and blowing dust across the eastern basin this evening. The
unstable moist air mass over the forecast area will also be ripe
for lifting by this gust front and the dynamic support from the
parent short wave into isolated to scattered thunderstorms across
the eastern half of the forecast area tonight...mandating a Red
Flag Warning for abundant lightning. Other than the potential
evening unpleasantness the late overnight period will be
uneventful but warm.
Tuesday and Wednesday feature the forecast area stuck under warm
southerly flow as the upper low remains largely stationary off
the coast. Other than another weak wave marginally detectable on
the GFS model due through the panhandle Wednesday
morning...thunderstorms will be largely confined to the mountains
ringing the Columbia Basin during the afternoons and evenings.
The big story of this period will be hot temperatures and sultry
overnight lows with generally light and terrain driven winds as a
strong surface thermal trough remains entrenched in the basin.
Thursday is the next potentially hazardous weather day. Models are
in good agreement and consistent in finally ejecting the upper low
inland...through the forecast area...Thursday night. After a few
days of sweltering temperatures the stage will be set for an
outbreak of thunderstorms...not just on the mountains but
everywhere...as the trough produces dynamic support aloft and a
strong cold front at the surface. These storms will probably begin
popping up during the day...isolated in the basin and scattered
over the mountains...as the trough approaches. Timing will be
critical as far as severe potential is concerned. A late
afternoon/evening arrival of the cold front will bear damaging
winds...blowing dust haboobs...organized lines of severe
thunderstorms and all manner of associated ugliness. A late
evening or overnight passage will be less vicious and probably
consist of scattered more garden variety thunderstorms and rain
showers with localized gusts followed by breezy to windy
conditions into Friday morning. This uncertainty forecast will be
refined and nailed down in the coming days as the "whites of the
eyes" become visible. /Fugazzi
Friday through Monday: A change to cooler and drier weather can be
expected for the upcoming weekend. After the strong cold front
pushes through late Thursday, the upper level low wobbles its way
across the northern Cascades and along the Canadian border Friday
and Friday night. This feature will enhance convection, continuing
the threat of showers with embedded thunderstorms as the cold pool
aloft swings through the region. Breezy winds can be expected on
Friday with sustained speeds of 15 to 25 mph from the Cascades and
across the Columbia Basin with gusts of 30-40 mph. The winds will
be in response to the substantial cooling expected Friday by 15
to 20 degrees. After a short heatwave, daytime temperatures Friday
will be stuck in the 70s. The upper level low will depart the
region by Saturday, leaving a flat ridge dominated by a westerly
flow aloft through the weekend with dry conditions and
temperatures moderating toward normal. Winds will be lighter but
occasional afternoon gusts are possible. The GFS and ECWMF show
the flat ridge buckling by Monday as another upper level low drops
down from BC and sits along the Canadian border. This will bring
another chance of showers to the northern mountains, slightly
cooler temperatures and locally breezy winds for Monday. /rfox.
&&
.AVIATION...
18Z TAFS: The timing of the shortwave seems to have slowed a bit
by a couple hours and have slowed the time of the convection.
Currently high clouds are pushing across the eastern TAF sites,
while mostly clear skies found across the Cascades and western
Basin. The atmosphere become increasingly unstable at this time
with scattered thunderstorms across much of extreme eastern WA and
into the ID panhandle. The focus of this thunderstorm activity is
expected to remain east of a line from KMWH to KOMK. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening
continues to be moderate. Expect a rapid transition to VFR
conditions behind this shortwave overnight into Tues AM. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 95 66 99 69 95 / 50 10 20 10 10 20
Coeur d`Alene 59 97 63 98 65 94 / 50 10 20 20 10 20
Pullman 55 97 60 98 63 93 / 60 10 20 10 10 20
Lewiston 65 104 69 105 71 100 / 50 10 20 10 10 30
Colville 60 99 59 102 59 99 / 30 20 10 10 10 20
Sandpoint 54 95 59 97 57 93 / 50 10 20 10 10 20
Kellogg 56 97 60 98 63 93 / 60 10 20 20 10 30
Moses Lake 63 100 64 102 66 96 / 40 10 10 0 0 20
Wenatchee 72 99 70 102 75 93 / 20 10 10 10 0 20
Omak 66 100 66 103 67 98 / 20 20 10 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 11 PM PDT this evening for Northern and
Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning until 11 PM PDT this evening for East
Washington Palouse and Spokane Area (Zone 674).
Red Flag Warning from 6 PM this evening to 2 AM PDT Tuesday for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
Red Flag Warning from 6 PM to 11 PM PDT this evening for East
Washington Northeast (Zone 686).
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
217 PM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Blue Mountains and Camas
Prairie and spreading across extreme eastern Washington and north
Idaho. A few record high temperatures may be set Wednesday with a
isolated mountain thunderstorms possible. A cold front late Thursday
will bring another round of potentially strong thunderstorms.
Breezy and cooler conditions are expected by Friday and into the
upcoming weekend.
&&
.DISCUSSION...
ACTIVE AND UNSETTLED WEATHER EXPECTED THIS WEEK FEATURING HOT
CONDITIONS...THUNDERSTORMS AND POTENTIALLY GUSTY WINDS.
Tonight through Thursday night...A very active weather period
fraught with potential hazards for multiple interested parties is
shaping up through the short term. The deep closed upper low
pressure visible on satellite circulating off the Oregon coast is
the main offender.
First...for tonight this low has spawned a short wave disturbance
on it`s east flank southerly flow migrating through Oregon this
afternoon which is triggering thunderstorms upstream from the
forecast area. The pattern for tonight is conducive for these
storms to spit out a gust front moving from south to north through
the eastern and possibly central Columbia Basin late this
afternoon through this evening. This is not a sure bet but the
threat is high enough based on previous case histories and
supported by some fine scale models to warrant mention of gusty
winds and blowing dust across the eastern basin this evening. The
unstable moist air mass over the forecast area will also be ripe
for lifting by this gust front and the dynamic support from the
parent short wave into isolated to scattered thunderstorms across
the eastern half of the forecast area tonight...mandating a Red
Flag Warning for abundant lightning. Other than the potential
evening unpleasantness the late overnight period will be
uneventful but warm.
Tuesday and Wednesday feature the forecast area stuck under warm
southerly flow as the upper low remains largely stationary off
the coast. Other than another weak wave marginally detectable on
the GFS model due through the panhandle Wednesday
morning...thunderstorms will be largely confined to the mountains
ringing the Columbia Basin during the afternoons and evenings.
The big story of this period will be hot temperatures and sultry
overnight lows with generally light and terrain driven winds as a
strong surface thermal trough remains entrenched in the basin.
Thursday is the next potentially hazardous weather day. Models are
in good agreement and consistent in finally ejecting the upper low
inland...through the forecast area...Thursday night. After a few
days of sweltering temperatures the stage will be set for an
outbreak of thunderstorms...not just on the mountains but
everywhere...as the trough produces dynamic support aloft and a
strong cold front at the surface. These storms will probably begin
popping up during the day...isolated in the basin and scattered
over the mountains...as the trough approaches. Timing will be
critical as far as severe potential is concerned. A late
afternoon/evening arrival of the cold front will bear damaging
winds...blowing dust haboobs...organized lines of severe
thunderstorms and all manner of associated ugliness. A late
evening or overnight passage will be less vicious and probably
consist of scattered more garden variety thunderstorms and rain
showers with localized gusts followed by breezy to windy
conditions into Friday morning. This uncertainty forecast will be
refined and nailed down in the coming days as the "whites of the
eyes" become visible. /Fugazzi
Friday through Monday: A change to cooler and drier weather can be
expected for the upcoming weekend. After the strong cold front
pushes through late Thursday, the upper level low wobbles its way
across the northern Cascades and along the Canadian border Friday
and Friday night. This feature will enhance convection, continuing
the threat of showers with embedded thunderstorms as the cold pool
aloft swings through the region. Breezy winds can be expected on
Friday with sustained speeds of 15 to 25 mph from the Cascades and
across the Columbia Basin with gusts of 30-40 mph. The winds will
be in response to the substantial cooling expected Friday by 15
to 20 degrees. After a short heatwave, daytime temperatures Friday
will be stuck in the 70s. The upper level low will depart the
region by Saturday, leaving a flat ridge dominated by a westerly
flow aloft through the weekend with dry conditions and
temperatures moderating toward normal. Winds will be lighter but
occasional afternoon gusts are possible. The GFS and ECWMF show
the flat ridge buckling by Monday as another upper level low drops
down from BC and sits along the Canadian border. This will bring
another chance of showers to the northern mountains, slightly
cooler temperatures and locally breezy winds for Monday. /rfox.
&&
.AVIATION...
18Z TAFS: The timing of the shortwave seems to have slowed a bit
by a couple hours and have slowed the time of the convection.
Currently high clouds are pushing across the eastern TAF sites,
while mostly clear skies found across the Cascades and western
Basin. The atmosphere become increasingly unstable at this time
with scattered thunderstorms across much of extreme eastern WA and
into the ID panhandle. The focus of this thunderstorm activity is
expected to remain east of a line from KMWH to KOMK. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening
continues to be moderate. Expect a rapid transition to VFR
conditions behind this shortwave overnight into Tues AM. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 64 95 66 99 69 95 / 50 10 20 10 10 20
Coeur d`Alene 59 97 63 98 65 94 / 50 10 20 20 10 20
Pullman 55 97 60 98 63 93 / 60 10 20 10 10 20
Lewiston 65 104 69 105 71 100 / 50 10 20 10 10 30
Colville 60 99 59 102 59 99 / 30 20 10 10 10 20
Sandpoint 54 95 59 97 57 93 / 50 10 20 10 10 20
Kellogg 56 97 60 98 63 93 / 60 10 20 20 10 30
Moses Lake 63 100 64 102 66 96 / 40 10 10 0 0 20
Wenatchee 72 99 70 102 75 93 / 20 10 10 10 0 20
Omak 66 100 66 103 67 98 / 20 20 10 10 10 30
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning until 11 PM PDT this evening for Northern and
Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning until 11 PM PDT this evening for East
Washington Palouse and Spokane Area (Zone 674).
Red Flag Warning from 6 PM this evening to 2 AM PDT Tuesday for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
Red Flag Warning from 6 PM to 11 PM PDT this evening for East
Washington Northeast (Zone 686).
&&
$$
Area Forecast Discussion
National Weather Service Spokane WA
1223 PM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Blue Mountains and Camas
Prairie and spreading across extreme eastern Washington and north
Idaho. A few record high temperatures may be set Wednesday with a
few mountain thunderstorms possible. A cold front Thursday will
bring another active thunderstorm threat along with cooler
temperatures by next weekend.
&&
.DISCUSSION...
...LIGHTNING AND GUSTY THUNDERSTORM WINDS POSSIBLE THIS EVENING...
The prospect of lightning and gusty thunderstorm outflow late this
afternoon and this evening continues to be our primary concern. As
of 12 PM, a compact vorticity max in southern Oregon was
activating instability over eastern Oregon around Burns and Baker
City. Thunderstorms that form over eastern Washington will track
north this afternoon and evening. We are uncertain whether these
cells will have enough deep layer instability and shear to come
off the terrain onto to the Palouse, West Plains and the northern
Panhandle. The NAM and several fine resolution convective
allowing models (HRRR, RAP and high resolution WRF) do maintain
thunderstorms through the evening into the Idaho Panhandle and
extreme eastern Washington. The northward extent of thunderstorms
may ultimately depend on how organized the clusters become over
Oregon this afternoon and whether clusters can produce a cold pool
strong enough to sustain northward propagation onto the Palouse
and West Plains. The large temperature/dewpoint spreads and
steep low level lapse rates suggest the possibility for gusty
outflow winds. Will there be enough deep layer shear to produce a
"haboob"? That is a tough call. Mid level winds (700-500mb) may
not be strong enough to promote a long lived gust front, but the
potential for blowing dust is there. /GKoch
&&
.AVIATION...
18Z TAFS: The timing of the shortwave seems to have slowed a bit
by a couple hours and have slowed the time of the convection.
Currently high clouds are pushing across the eastern TAF sites,
while mostly clear skies found across the Cascades and western
Basin. The atmosphere become increasingly unstable at this time
with scattered thunderstorms across much of extreme eastern WA and
into the ID panhandle. The focus of this thunderstorm activity is
expected to remain east of a line from KMWH to KOMK. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening
continues to be moderate. Expect a rapid transition to VFR
conditions behind this shortwave overnight into Tues AM. /rfox
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 91 64 97 66 100 69 / 10 40 10 20 10 10
Coeur d`Alene 92 59 97 63 99 65 / 20 40 10 20 20 10
Pullman 90 55 96 60 98 63 / 40 30 10 20 10 10
Lewiston 96 65 102 69 106 71 / 40 30 10 20 10 10
Colville 94 60 99 59 104 59 / 10 30 20 10 10 10
Sandpoint 90 54 95 59 98 57 / 20 30 10 20 10 10
Kellogg 92 56 96 60 98 63 / 30 50 10 20 20 10
Moses Lake 94 63 100 64 103 66 / 10 20 10 10 0 0
Wenatchee 94 72 99 70 102 75 / 10 20 10 10 10 0
Omak 96 66 101 66 102 67 / 0 20 20 10 10 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...Red Flag Warning from 2 PM this afternoon to 11 PM PDT this
evening for Northern and Central Idaho Panhandle (Zone 101).
WA...Red Flag Warning from 2 PM this afternoon to 11 PM PDT this
evening for East Washington Palouse and Spokane Area (Zone
674).
Red Flag Warning from 6 PM this evening to 2 AM PDT Tuesday for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
Red Flag Warning from 6 PM to 11 PM PDT this evening for East
Washington Northeast (Zone 686).
&&
$$
AREA FORECAST DISCUSSION
NWS SEATTLE WA
900 AM PDT MON AUG 10 2015
.SYNOPSIS...AN UPPER LEVEL LOW WILL SLIDE SOUTH OVER THE OFFSHORE
WATERS THROUGH MIDWEEK KEEPING WEATHER GENERALLY WARM WITH PARTLY
TO MOSTLY SUNNY SKIES. THERE WILL BE SOME LIGHT SPOTTY SHOWERS
MAINLY TUESDAY NIGHT AND WEDNESDAY. THE UPPER LEVEL LOW WILL MOVE
BACK TO THE NORTHEAST TOWARD THE AREA THURSDAY AND OVER WESTERN
WASHINGTON THURSDAY NIGHT FOR CLOUDIER SKIES...COOLER WEATHER AND
A CHANCE OF SHOWERS.
&&
.SHORT TERM...THE UPPER LEVEL LOW OFF THE WASHINGTON COAST HELPING STREAM
MID LEVEL CLOUDS ACROSS WESTERN WASHINGTON EARLY THIS MORNING WITH A
FEW SHOWERS MOVING NORTH OVER THE AREA THIS MORNING. WENT AHEAD AND
UPDATED THE FORECAST FOR THIS MORNING TO REFLECT MORE CLOUDINESS
THIS MORNING AND A CHANCE OF SHOWERS MOST AREAS. OTHERWISE SHOWERS
SHOULD MOVE NORTH OF THE AREA THIS MORNING LEAVING MID/HIGH LEVEL
CLOUDS AT TIMES THROUGH THE AFTERNOON WITH PARTLY SUNNY SKIES.
MOSTLY CLOUDY SKIES THIS MORNING WILL INHIBIT THE HIGH TEMPERATURES
A BIT TODAY. HOWEVER...SKIES ARE ALREADY CLEARING OVER THE FAR SOUTH
THIS MORNING WHICH WILL HELP SOME OF THE WARMER LOCATIONS REACH
INTO THE MID 80S TODAY.
A WEAK EMBEDDED UPPER LEVEL DISTURBANCE WILL BRUSH THE SOUTHERN
PORTION OF THE AREA TONIGHT KEEPING A CHANCE OF SHOWERS AND
THUNDERSTORMS OVER THE SOUTH THIS EVENING. THE REMAINDER OF THE AREA
WILL REMAIN DRY WITH MID/HIGH LEVEL CLOUDS.
WARMER TEMPERATURES ALOFT ON TUESDAY WILL BOOST HIGHS INTO THE 80S
WITH SOME LOWER 90S ARE POSSIBLE ESPECIALLY OVER THE SOUTH INTERIOR
AND ALONG THE CENTRAL AND SOUTH CASCADE FOOTHILLS. A SECOND WEAK
UPPER LEVEL DISTURBANCE WILL BRUSH THE AREA TUESDAY NIGHT FOR
ANOTHER CHANCE OF SHOWERS OVER THE AREA.
THE UPPER LEVEL LOW OVER THE WASHINGTON OFFSHORE WATERS WILL MOVE TO
THE CALIFORNIA OFFSHORE WATERS BEFORE BOUNCING BACK TO THE NORTHEAST
ON WEDNESDAY. THE CURRENT FORECAST FOR WEDNESDAY HAS A CHANCE OF
SHOWERS WITH PARTLY SUNNY SKIES TO REFLECT THE POTENTIAL FOR
EMBEDDED UPPER LEVEL DISTURBANCES AHEAD OF THE MAIN UPPER LEVEL LOW.
LOW LEVEL ONSHORE FLOW WILL STRENGTHEN SOMEWHAT RESULTING IN A WEAK
PUSH WITH MUCH COOLER HIGH TEMPERATURES ALONG THE COAST AND AROUND 5
DEGREES COOLER THOUGH THE INTERIOR.
.LONG TERM...FROM PREVIOUS DISCUSSION...EXTENDED MODELS IN GOOD
AGREEMENT ON THE 00Z RUN WITH THE LOW WEAKENING AND MOVING THROUGH
WESTERN WASHINGTON THURSDAY NIGHT INTO FRIDAY MORNING WITH THE UPPER
LEVEL TROUGH HANGING BACK OVER THE AREA DURING THE DAY ON FRIDAY.
WITH THE LOW OVER THE AREA EXPECT CLOUDIER AND COOLER WEATHER WITH
SCATTERED SHOWERS. UPPER LEVEL RIDGE BUILDING OVER THE AREA OVER THE
WEEKEND WITH THE LOW LEVEL FLOW ONSHORE FOR RETURN TO SUNNY WEATHER
WITH TEMPERATURES NEAR OR JUST A LITTLE ABOVE NORMAL. FELTON
&&
.AVIATION...THERE IS AN UPPER LEVEL LOW OFFSHORE WITH SOUTHERLY FLOW
ALOFT OVER WASHINGTON. THE AIR MASS IS MOIST AND UNSTABLE THIS
MORNING. SOME DRYING AND STABILIZATION IS FORECAST TO OCCUR THIS
AFTERNOON. HIGH AND MID LEVEL CLOUDS OVER MOST OF THE AREA WILL
CLEAR FROM THE SOUTH. THE COAST ALSO HAS AREAS OF MARINE STRATUS
THAT SHOULD LIFT IN THE AFTERNOON.
CEILINGS ARE GENERALLY VFR WITH CLOUDS 8-11K FT. THE COAST HAS IFR
CEILINGS. CONDITIONS WILL IMPROVE IN THE AFTERNOON.
KSEA...SHOWERS MOVING THROUGH THE AREA SHOULD BE GONE BY 18Z AND
THERE WILL BE SOME CLEARING. SOUTHERLY WINDS 4-8 KT WILL BECOME
NORTHWESTERLY AROUND 00Z. CHB
&&
.MARINE...LIGHT WINDS WILL CONTINUE TONIGHT WITH WEAK PRESSURE
GRADIENTS. ONSHORE FLOW WILL INCREASE SOMEWHAT IN THE AFTERNOON BUT
WILL KEEP FORECAST WINDS IN THE STRAIT TO WESTERLY 10-20 KT FOR NOW.
ONSHORE GRADIENTS WILL INCREASE LATER IN THE WEEK.
&&
.SEW WATCHES/WARNINGS/ADVISORIES... WA...NONE. PZ...NONE.
&&
$$
WWW.WEATHER.GOV/SEATTLE
YOU CAN SEE AN ILLUSTRATED VERSION OF THIS DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
Area Forecast Discussion
National Weather Service Spokane WA
458 AM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Northeast Blue Mountains
and Camas Prairie areas and propagating as far north as the Northeast
Mountains and Northern Panhandle. A few record high temperatures
may be set Wednesday. A cold front thursday will bring another
active thunderstorm threat along with cooler temperatures by next
weekend.
&&
.DISCUSSION...
...STRONG WINDS POSSIBLE WITH THUNDERSTORMS TODAY...
Today and Tonight: There are a couple of vorticity maximums to
watch out for today. Both are swinging around the base of a deep
upper level low pressure system off of the coast of WA. The first,
and more likely to have the bigger impact, is a shortwave
disturbance currently pushing into northern California early this
morning. This disturbance is progged to quickly push northeast and
begin to push up into the region between noon and 200 PM PDT.
Before we do see the effects of this disturbance, we will see some
lingering light shower activity mainly across the northern half of
the forecast area through this morning.
Satellite imagery indicates a lot of clearing occurring behind
these showers. This will set up a situation where there should be
plenty of sunshine for the atmosphere to destabilize by the
afternoon before the disturbance over California makes it this far
north. Moisture will increase across the region with dew points
expected to remain right around 50 degrees. This will set up the
ingredients for a decent amount of surface based CAPE to work
with. Models are generally showing somewhere in the neighborhood
of 500-1500 J/KG of surface based CAPE across the eastern half of
the forecast area; this generally includes areas east of a line
extending from Ritzville to Republic. Thunderstorms are expected
to initiate over northeast OR and in the southern Panhandle in the
early afternoon and the push northward into southeastern WA and
into the central Panhandle through the afternoon hours. Main
threats with the thunderstorms will be for strong outflow winds.
The WRF-NMM, WRF-ARW and HRRR models all show a signal of a gust
front emanating northward from the convection. These models have
also been consistent with this idea over the past few runs. I
increase winds across the Palouse, into the basin, the Spokane-
Coeur d`Alene corridor and into the northern mtns and ID
Panhandle. These winds may also result in blowing dust with
reduced visibility possible across portions of I-90 and highway 2.
Forecast confidence in the strong outflow winds and blowing dust
is only moderate and there is some bust potential as all the
ingredients need to come together. With that said, there is enough
evidence that concerns are increasing.
Thunderstorms are also expected to include frequent cloud to
ground lightning strikes. There will be some rain with the heavier
thunderstorm cores, but, away from these course, there will also
be a lot of evaporation that takes place. This should result in a
higher potential for new fire starts from lightning strikes. The
Fire Weather Watch will remain as is for now and will be
reassessed later in the morning.
A second disturbance will push up more across central OR in the
wake of the first. This piece of energy will spark off more
thunderstorms that will push northward through the late afternoon
hours. These thunderstorms will push into southern WA by the
evening, but much of the energy will begin to curl off to the
west. This should reduce the amount of forcing that enters the
region with this wave and is expected to result in thunderstorms
diminishing in intensity by this time. /SVH
Tues through Sunday: The Thurs/Fri ejection of the upper trough
still looks like the main focus as far as any widespread thunder
threat and post- frontal windy wx. The vast majority of model
guidance remain similar with digging the upper low S down the Pac
Nw coast. The primary challenge will be dealing with the ejection
of this low NE into Ern Wa and N Idaho Thurs & Fri. The ECMWF is
now only slightly faster to eject this wave NE, and both the GFS
and ECMWF continue with the trend of taking the low nearly
straight north across Wrn Wa and the Cascades. This would mean the
highest threat of thunder would be along and near the Cascades,
definitely NOT where we would prefer given the current wildfires
that may be enhanced by gusty outflow, not to mention new fire
starts. And if this Cascades pcpn is slow to exit, another issue
COULD be debris flows on current and recent burns. Though this is
the most important part of the fcst, it may not be the most
challenging part. As the wave digs S down the coast, Ern Wa and N
Idaho will be in a prolonged southerly fetch of increasing
moisture within a high- amplitude thermal ridge. This will not
only help to destabilize the sfc, but will also complicate matters
since there are at least three nocturnal subtle waves that move N
into Ern Wa through Wed. All of these accompany weak to moderate
convective/potential instability not rooted at the surface that
could produce a few overnight lightning strikes. Overnight low
temps will be very mild. And within the aforementioned thermal
ridge, Spokane may not be the only place that tops record high
temps Wed.bz
&&
.AVIATION...
12Z TAFS: A potent shortwave trough of lower pressure will push
across the region after 20Z. The atmosphere become increasingly
unstable at this time with scattered thunderstorms across much of
extreme eastern WA and into the ID panhandle. The focus of this
thunderstorm activity is expected to remain east of a line from
KMWH to KOMK. Timing of storms at KLWS and KPUW is expected
between 20-00Z and between 23-04Z at KGEG, KSFF and KCOE. Primary
concerns with thunderstorms will be for strong outflow winds and
frequent lightning strikes. Visibility may also be reduced at the
TAF sites from blowing, especially at the KGEG, KSFF and KMWH TAF
sites. Confidence of thunderstorms this afternoon and evening is
moderate. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 91 64 97 66 100 69 / 20 40 10 20 10 10
Coeur d`Alene 92 59 97 63 99 65 / 30 40 10 20 10 10
Pullman 90 55 96 60 98 63 / 40 30 10 20 20 10
Lewiston 96 65 102 69 106 71 / 40 20 20 20 20 10
Colville 94 60 99 59 104 59 / 20 20 10 20 20 20
Sandpoint 90 54 95 59 98 57 / 20 30 10 20 20 20
Kellogg 92 56 96 60 98 63 / 30 50 10 20 10 20
Moses Lake 94 63 100 64 103 66 / 10 20 10 20 10 10
Wenatchee 94 72 99 70 102 75 / 10 30 10 20 20 10
Omak 96 66 101 66 102 67 / 20 30 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for Northern and Central Idaho Panhandle (Zone 101).
WA...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for East Washington Palouse and Spokane Area (Zone
674).
FIRE Weather Watch from this afternoon through late tonight for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
300 AM PDT MON AUG 10 2015
.SYNOPSIS...A LOW PRESSURE SYSTEM CENTERED OFF THE WASHINGTON COAST
ALONG 130W EARLY THIS MORNING WILL CONTINUE MOVING SOUTHWARD OFF THE
COAST...REACHING WEST OF THE NORTHERN CALIFORNIA COAST TUESDAY...
THEN LIFTING OUT TO THE NORTHEAST AND THROUGH THE PACIFIC NORTHWEST
THURSDAY AND FRIDAY. LOOK FOR OCCASIONAL SHOWERS OR THUNDERSTORMS IN
THE AFTERNOONS AND EVENINGS DURING THE WEEK THAT MAY DRIFT OUT INTO
THE VALLEYS AND THE COAST RANGE AT TIMES IN THE EVENINGS AND
OVERNIGHT PERIODS. THE BEST CHANCE OF MORE WIDESPREAD SHOWERS OR
THUNDERSTORMS IS LATER THURSDAY INTO FRIDAY AS THE LOW MOVES ONSHORE
AND INLAND. WARMER AND DRY WEATHER IS EXPECTED TO RETURN NEXT
WEEKEND.
&&
.SHORT TERM...AS ADVERTISED...A CLOSED UPPER LOW WAS LOCATED OFF THE
WASHINGTON COAST EARLY THIS MORNING CENTERED ALONG 130W. THE LOW WILL
CONTINUE TO MOVE SOUTHWARD AND WILL BE CENTERED OFF THE OREGON COAST
THIS AFTERNOON. THIS WILL CAUSE THE FLOW ALOFT TO BACK TO MORE
SOUTHERLY TODAY...WARMING THE AIR MASS SOME. A BAROCLINIC OR FRONTAL
ZONE HAS DEVELOPED OVER THE COASTAL WATERS BUT WILL HAVE TROUBLE
MAKING MUCH INLAND PROGRESSION TODAY DUE TO THE SOUTHERLY FLOW ALOFT.
THE COAST MIGHT GET BRUSHED WITH A FEW SHOWERS THOUGH. TEMPS INLAND
TODAY WILL BE IN AT LEAST THE MID 80S AND POSSIBLY THE UPPER 80S. THE
MODELS ALSO INDICATE THAT CONVECTION WILL DEVELOP OVER THE CASCADES
AND FOOTHILLS THIS AFTERNOON AS A SHORT WAVE LIFTS NORTH ALONG THE
EASTERN PERIPHERY OF THE OFFSHORE LOW...AND POSSIBLY EVEN OVER THE
VALLEY OR INTO THE COAST RANGE LATER TODAY OR TONIGHT. THERE IS SOME
UPPER JET SUPPORT FOR THIS CONVECTION TODAY AND THIS EVENING...AND
SOME OF THE THUNDERSTORMS THAT DO DEVELOP COULD BE STRONGER THAN WHAT
WE NORMALLY SEE. AS THE LOW CONTINUES TO MOVE SOUTH TONIGHT INTO
TUESDAY...THE UPPER FLOW TURNS SOUTHEASTERLY AND WILL CAUSE ANY
RESIDUAL ACTIVITY TO DRIFT OUT OVER THE VALLEYS AND TOWARD THE COAST
RANGE TONIGHT.
THINGS SHOULD SETTLE DOWN BY TUESDAY MORNING AS THE LAST OF THE
MOISTURE DRIFTS OUT OVER THE COASTAL WATERS AND WEAKENS. THE LOW WILL
CONTINUE TO MOVE SOUTH AND BE CENTERED SOUTH OF 40N AND WEST OF 130W
OFF THE NORTHERN CALIFORNIA COAST BY LATER TUESDAY. THERE IS AGAIN A
CHANCE OF THUNDER OVER THE CASCADES TUESDAY AFTERNOON THAT COULD
DRIFT OUT OVER THE VALLEYS TUESDAY NIGHT UNDER PREVAILING SOUTHEAST
FLOW ALOFT. THE AIR MASS WILL CONTINUE TO BE QUITE WARM TO THE EAST
AND NORTHEAST OF THE LOW ON TUESDAY...AND INLAND TEMPS MAY APPROACH
90 ON TUESDAY.
THE LOW MEANDERS OFF THE NORTHERN CALIFORNIA COAST WEDNESDAY. THE
MODELS SUGGEST THAT AFTER THE RESIDUAL CONVECTIVE ACTIVITY FROM
TUESDAY NIGHT DRIFTS NORTHWEST AND AWAY FROM OUR AREA WEDNESDAY
MORNING...THAT ACTIVITY WILL BE LESS WEDNESDAY AFTERNOON AND EVENING.
HAVE KEPT A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDER OVER THE
CASCADES.
THE MODELS SHOW OUR CURRENT SOUTH WINDS ALONG THE COAST THIS MORNING
TURNING NORTHERLY IN THE WAKE OF THE LOW LATER TODAY AND TONIGHT. THE
WINDS THEN TURN BACK TO SOUTHERLY AGAIN WEDNESDAY AS A SOUTHERLY WIND
REVERSAL AND STRATUS SURGE MOVES UP THE COAST IN RESPONSE TO SHORT
WAVE MOVING NORTH ALONG THE COAST. THIS SHOULD BUILD THE MARINE LAYER
ALONG THE COAST AND IS THE FIRST STEP IN STARTING TO INCREASE THE
ONSHORE FLOW. WE MAY SEE SOME PATCHY DRIZZLE IN THIS STRENGTHENING
MARINE LAYER. THE SOUTHERLY WINDS THAT DEVELOP ALONG THE COAST
WEDNESDAY MAY BE A BIT BREEZY AS WELL. TOLLESON
.LONG TERM...THE LOW THAT DROPPED SOUTH ALONG THE COAST DURING THE
EARLY PART OF THE FORECAST IS EXPECTED TO APPROACH THE OREGON COAST
THURSDAY AND MOVE NORTHEAST ACROSS SOUTHWEST WASHINGTON AND NORTHWEST
OREGON THURSDAY NIGHT AND EARLY FRIDAY. THIS WILL BRING AN INCREASED
CHANCE OF SHOWERS...WITH A FEW THUNDERSTORMS POSSIBLE DUE TO
INSTABILITY FROM THE COLD POOL ALOFT WITH THE UPPER LOW. THIS WILL
ALSO BRING A STRONG SOUTHWEST MARINE PUSH TO OUR FORECAST AREA WITH
WIDESPREAD CLOUDS AND COOLER TEMPS THROUGH FRIDAY. THE MODELS ARE
THEN GENERALLY DRY FOR THE WEEKEND BUT DIFFER ON HOW WARM IT WILL
BE...AND HAVE OPTED FOR A BLEND OF THE MODELS FOR NOW AS NORTHWEST
FLOW ALOFT PREVAILS. THE MODELS HINT AT ANOTHER TROUGH DROPPING DOWN
FROM THE NORTHWEST EARLY NEXT WEEK...BUT THE GFS IS STRONGER AND DIGS
IT MORE SOUTHWARD WHILE THE ECMWF KEEPS THE MAIN PART OF THE TROUGH
SLIDING BY TO OUR NORTH. HAVE OPTED TO STAY DRY FOR NOW BUT WITH SOME
ONSHORE FLOW CONTINUING/INCREASING. TOLLESON
&&
.AVIATION...VFR CONDITIONS WITH CIGS BETWEEN 10K-25K FT WILL
GENERALLY PERSIST NEXT 24 HRS FOR INLAND SITES. MVFR AND IFR CIGS
ALONG THE COAST WILL CONTINUE TONIGHT UNDER SOUTH-SOUTHWEST
FLOW...BUT CIGS APPEAR TO BE RISING PARTICULARLY ALONG THE N OR
COAST. EXPECT MOSTLY MVFR CIGS ON THE COAST THROUGH MORNING. FOR
MON...CHANCE OF TSRA FROM THE COAST RANGE EASTWARD IN THE LATE
AFTERNOON AND EVENING BUT WITH DISAGREEMENT AMONG MODELS...WILL LEAVE
OUT MENTION FOR NOW.
KPDX AND APPROACHES...VFR NEXT 24 HOURS. SLIGHT CHANCE SHRA OR TSRA
MAINLY AFTER 00Z. BOWEN
&&
.MARINE...NOT MUCH CHANGE TO THE FORECAST WITH WINDS BELOW ABOUT 15
KTS AND SEAS AROUND 4 FT THROUGH MUCH OF THE WEEK. WEAK SURFACE LOW
CURRENTLY SITS OFF THE WASHINGTON COAST OVER THE OFFSHORE WATERS BUT
BIGGEST IMPACT WILL BE VARIABLE WIND DIRECTION WITH A VARYING DEGREE
OF SOUTH OR WEST COMPONENT IN THE WIND AS THE LOW SLOWLY DRIFTS
THROUGH THE REGION OVER THE NEXT 48 HOURS. SURFACE HIGH PRESSURE
BUILDS OVER THE NE PACIFIC STARTING MIDWEEK AND ESPECIALLY INTO LATE
WEEK. THE NEXT THREAT FOR SMALL CRAFT ADVISORY STRENGTH WINDS LOOKS
TO BE AROUND FRIDAY AS THERMAL LOW PRESSURE DEEPENS ALONG THE N
CALIFORNIA/SW OREGON COAST. HOWEVER MODELS HAVE AT LEAST TEMPORARILY
BACKED OFF ON WINDS LATE WEEK.BOWEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING FROM NOON TODAY TO 11 PM PDT TUESDAY FOR
CENTRAL OREGON CASCADE FOOTHILLS-MT. HOOD NATIONAL FOREST
WEST OF CASCADE CREST-NORTH OREGON CASCADE FOOTHILLS-
WILLAMETTE NATIONAL FOREST.
WA...FIRE WEATHER WATCH FROM 1 PM PDT THIS AFTERNOON THROUGH LATE
TONIGHT FOR EXTREME SOUTH WASHINGTON CASCADES AND FOOTHILLS.
PZ...NONE.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
Area Forecast Discussion
National Weather Service Spokane WA
258 AM PDT MON AUG 10 2015
.SYNOPSIS...
Hot weather will return for most of the work week with a continued
chance of thunderstorms. Some storms may produce strong winds this
afternoon and evening, mainly from the Northeast Blue Mountains
and Camas Prairie areas and propagating as far north as the Northeast
Mountains and Northern Panhandle. A few record high temperatures
may be set Wednesday. A cold front thursday will bring another
active thunderstorm threat along with cooler temperatures by next
weekend.
&&
.DISCUSSION...
...STRONG WINDS POSSIBLE WITH THUNDERSTORMS TODAY...
Today and Tonight: There are a couple of vorticity maximums to
watch out for today. Both are swinging around the base of a deep
upper level low pressure system off of the coast of WA. The first,
and more likely to have the bigger impact, is a shortwave
disturbance currently pushing into northern California early this
morning. This disturbance is progged to quickly push northeast and
begin to push up into the region between noon and 200 PM PDT.
Before we do see the effects of this disturbance, we will see some
lingering light shower activity mainly across the northern half of
the forecast area through this morning.
Satellite imagery indicates a lot of clearing occurring behind
these showers. This will set up a situation where there should be
plenty of sunshine for the atmosphere to destabilize by the
afternoon before the disturbance over California makes it this far
north. Moisture will increase across the region with dew points
expected to remain right around 50 degrees. This will set up the
ingredients for a decent amount of surface based CAPE to work
with. Models are generally showing somewhere in the neighborhood
of 500-1500 J/KG of surface based CAPE across the eastern half of
the forecast area; this generally includes areas east of a line
extending from Ritzville to Republic. Thunderstorms are expected
to initiate over northeast OR and in the southern Panhandle in the
early afternoon and the push northward into southeastern WA and
into the central Panhandle through the afternoon hours. Main
threats with the thunderstorms will be for strong outflow winds.
The WRF-NMM, WRF-ARW and HRRR models all show a signal of a gust
front emanating northward from the convection. These models have
also been consistent with this idea over the past few runs. I
increase winds across the Palouse, into the basin, the Spokane-
Coeur d`Alene corridor and into the northern mtns and ID
Panhandle. These winds may also result in blowing dust with
reduced visibility possible across portions of I-90 and highway 2.
Forecast confidence in the strong outflow winds and blowing dust
is only moderate and there is some bust potential as all the
ingredients need to come together. With that said, there is enough
evidence that concerns are increasing.
Thunderstorms are also expected to include frequent cloud to
ground lightning strikes. There will be some rain with the heavier
thunderstorm cores, but, away from these course, there will also
be a lot of evaporation that takes place. This should result in a
higher potential for new fire starts from lightning strikes. The
Fire Weather Watch will remain as is for now and will be
reassessed later in the morning.
A second disturbance will push up more across central OR in the
wake of the first. This piece of energy will spark off more
thunderstorms that will push northward through the late afternoon
hours. These thunderstorms will push into southern WA by the
evening, but much of the energy will begin to curl off to the
west. This should reduce the amount of forcing that enters the
region with this wave and is expected to result in thunderstorms
diminishing in intensity by this time. /SVH
Tues through Sunday: The Thurs/Fri ejection of the upper trough
still looks like the main focus as far as any widespread thunder
threat and post- frontal windy wx. The vast majority of model
guidance remain similar with digging the upper low S down the Pac
Nw coast. The primary challenge will be dealing with the ejection
of this low NE into Ern Wa and N Idaho Thurs & Fri. The ECMWF is
now only slightly faster to eject this wave NE, and both the GFS
and ECMWF continue with the trend of taking the low nearly
straight north across Wrn Wa and the Cascades. This would mean the
highest threat of thunder would be along and near the Cascades,
definitely NOT where we would prefer given the current wildfires
that may be enhanced by gusty outflow, not to mention new fire
starts. And if this Cascades pcpn is slow to exit, another issue
COULD be debris flows on current and recent burns. Though this is
the most important part of the fcst, it may not be the most
challenging part. As the wave digs S down the coast, Ern Wa and N
Idaho will be in a prolonged southerly fetch of increasing
moisture within a high- amplitude thermal ridge. This will not
only help to destabilize the sfc, but will also complicate matters
since there are at least three nocturnal subtle waves that move N
into Ern Wa through Wed. All of these accompany weak to moderate
convective/potential instability not rooted at the surface that
could produce a few overnight lightning strikes. Overnight low
temps will be very mild. And within the aforementioned thermal
ridge, Spokane may not be the only place that tops record high
temps Wed.bz
&&
.AVIATION...
06Z TAFS: A closed upper level low pressure system will remain
positioned off of the Washington Coast. Disturbance rotating
ahead of this low will move north and northeast and bring
increased mid level clouds along with some showers and
thunderstorms overnight tonight into Monday morning. Additional
disturbances will bring more potential for showers and
thunderstorms after 23Z Monday into the evening that could bring a
better chance of gusty wind. All TAF sites are expected to remain
VFR through 06Z tuesday. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 91 64 97 66 100 69 / 20 40 10 20 10 10
Coeur d`Alene 92 59 97 63 99 65 / 30 40 10 20 10 10
Pullman 90 55 96 60 98 63 / 40 30 10 20 20 10
Lewiston 96 65 102 69 106 71 / 40 20 20 20 20 10
Colville 94 60 99 59 104 59 / 20 20 10 20 20 20
Sandpoint 90 54 95 59 98 57 / 20 30 10 20 20 20
Kellogg 92 56 96 60 98 63 / 30 50 10 20 10 20
Moses Lake 94 63 100 64 103 66 / 10 20 10 20 10 10
Wenatchee 94 72 99 70 102 75 / 10 30 10 20 20 10
Omak 96 66 101 66 102 67 / 20 30 10 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for Northern and Central Idaho Panhandle (Zone 101).
WA...FIRE Weather Watch from 2 PM PDT this afternoon through late
tonight for East Washington Palouse and Spokane Area (Zone
674).
FIRE Weather Watch from this afternoon through late tonight for
East Washington South Central Cascade Mountains (Zone 680)-
East Washington South Central Cascade Valleys (Zone 676).
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1038 PM CDT TUE AUG 11 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO THE SOUTHERN GREAT PLAINS
EARLY THIS AFTERNOON. DIURNAL CU POPPED BY 15-16Z AND SPREAD SOUTH
TO COVER SCT-BKN CONDITIONS ACROSS MUCH OF THE STATE. A SHORTWAVE
CURRENTLY OVER WESTERN LAKE SUPERIOR WILL MOVE ACROSS NORTHEAST
WISCONSIN LATE IN THE DAY AND MAY PROLONG SCT CLOUD COVER INTO THIS
EVENING. OTHERWISE...THE MAIN FOCUS INCLUDES THUNDERSTORM POTENTIAL
FROM MID-LEVEL WARM ADVECTION FOR WEDNESDAY. SCATTERED
THUNDERSTORMS OCCURRED EARLIER TODAY OVER THE LAKE WINNIPEG REGION
IN THIS WARM ADVECTION ZONE.
TONIGHT...HIGH PRESSURE WILL SLIDING SOUTHEAST ACROSS THE WESTERN
GREAT LAKES WHILE A SHORTWAVE EXITS NORTHEAST WISCONSIN DURING THE
EVENING. THE SHORTWAVE MAY PROLONG SCT CLOUD COVER ACROSS EASTERN
WISCONSIN INTO MID-EVENING...BUT THE REST OF THE AREA SHOULD SEE
CLEARING SKIES WITH LOSS OF DAYTIME HEATING. ONCE THE CLOUDS
DISSIPATE...WILL SEE A PERIOD OF CLEAR CONDITIONS UNTIL LATE IN THE
NIGHT WHEN WARM ADVECTION CLOUDS MOVE SOUTHEAST INTO NORTH-CENTRAL
WISCONSIN. WITH CLOUDS ARRIVING LATE...DO NOT THINK FOG WILL BECOME
TOO BIG OF AN ISSUE. LOWS MAINLY IN THE LOWER TO MIDDLE 50S.
WEDNESDAY...WARM ADVECTION WILL CONTINUE ACROSS THE REGION. THE
BAND OF ASSOCIATED MID-CLOUDS WILL PROCEED EAST ACROSS THE FORECAST
AREA DURING THE MORNING AND THEN EXIT NORTHEAST WI AROUND MID-
AFTERNOON. SOME ELEVATED INSTABILITY GRAZES NORTHERN WISCONSIN
DURING THIS TIME...ALONG WITH MID-LEVEL FGEN ON THE NOSE OF A LLJ.
THOUGH MOISTURE IS NOT PLENTIFUL...NOT COMFORTABLE GOING DRY IN THIS
SCENARIO. SO WILL SHOW 20-30 PCT CHANCE OF RAIN ACROSS FAR N-C AND
PARTS OF NORTHEAST WI. THE REST OF THE AREA SHOULD SEE A PERIOD A
PARTLY/MOSTLY CLOUDY SKIES. HIGHS WARMING A COUPLE DEGREES...WITH
READINGS RANGING FROM THE UPPER 70S TO MID 80S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
WITH AMPLIFICATION OF THE WESTERN RIDGE EXPECTED THE REST OF THIS
WEEK...OUR AREA WILL CONTINUE TO FALL UNDER NORTHWEST FLOW.
DESPITE THAT...ABOVE NORMAL HEIGHTS AND WARM AIR ADVECTION FROM
THE WEST SHOULD KEEP TEMPERATURES ABOVE NORMAL...PERHAPS EVEN
SIGNIFICANTLY SO.
THE MAJOR FORECAST CHALLENGE REMAINS PRECIPITATION CHANCES FROM
WEDNESDAY NIGHT THROUGH THE WEEKEND. THOUGH THE GENERAL IDEA OF
MULTIPLE WEAK SHORTWAVE TROUGHS AND AT TIMES ASSOCIATED FRONTS
REMAINS SOLID...THE EXACT DETAILS REMAIN A BIT MUDDY. WEDNESDAY
NIGHT SEEMS PARTICULARLY CHALLENGING AS MANY INGREDIENTS ARE
PRESENT...BUT IN A DISJOINTED MANNER THAT DON`T ENTIRELY SUGGEST
STRONG POTENTIAL FOR CONVECTION. A THETA-E GRADIENT NOSES THROUGH
THE REGION EARLIER IN THE DAY...AND A MIDLEVEL VORT MAX SWINGS
THROUGH IN THE EVENING ALONG WITH MODEST INSTABILITY AND SHEAR BUT
LACKING ANY SIGNIFICANT TRIGGERING MECHANISM. IN THE OVERNIGHT
HOURS TOWARDS DAYBREAK...COULD BEGIN TO SEE INFLUENCE FROM AN
APPROACHING COLD FRONT. THOUGH I GET THE FEELING THAT THE EVENING
WILL END UP DRY...CAN`T RULE DEVELOPMENT OUT AND SO SOME LOW-END
POPS REMAIN. POPS THEN BEGIN TO INCREASE TOWARDS MORNING AS THE
FRONT DRAWS NEARER IN DEFERENCE TO THE MORE PROGRESSIVE ELEMENTS
OF THE MODEL ENVELOPE.
THURSDAY PERHAPS SHOWS THE BEST POTENTIAL FOR STORMS AS THE FRONT
SWINGS INTO THE AREA ALONG WITH BETTER INSTABILITY. INDEED...THE
GFS SUGGESTS UP TO 3000 J/KG OF CAPE IN THE NORTHWOODS LATE
THURSDAY AFTERNOON INTO THE EVENING AND MARGINAL 30 KNOT SHEAR.
FORECAST SOUNDINGS AGAIN SHOW CAPPING THURSDAY WHICH COULD BE
RESTRICTIVE...BUT THE FRONT SHOULD AID IN OVERCOMING THAT...AS
LONG AS IT MOVES IN QUICKLY ENOUGH. STEEP TEMPERATURE-DEWPOINT
SPREADS AT THE SURFACE AND A STRONGLY MIXED BOUNDARY LAYER CREATE
THE POTENTIAL FOR INVERTED-V TYPE SOUNDINGS. IF CONVECTION BECOMES
STRONG ENOUGH...THERE COULD BE SOME GUSTY WINDS TO BE FOUND.
GUIDANCE DOES BEGIN TO DIVERGE BUT...EITHER DUE TO SLOWER TIMING
IN SOME MODELS...AND STALLING THE FRONT OUT OVER SOUTHERN
WISCONSIN IN OTHERS...THE CHANCE FOR LINGERING RAIN DRAGS INTO
FRIDAY IN CENTRAL AND EAST CENTRAL WISCONSIN.
WE SHOULD THEN SEE A DRYING TREND THROUGH MOST OF THE WEEKEND AS
RIDING BUILDS INTO THE REGION AND TEMPERATURES ONLY A BIT COOLER
BEHIND THE WEAK FRONT. FINALLY...THE MIDLEVEL RIDGE WILL BEGIN TO
FLATTEN AS AN UPPER TROUGH SWINGS THROUGH CANADA. THE COLD FRONT
ASSOCIATED WITH ITS SURFACE REFLECTION LOOKS TO COME THROUGH THE
AREA SUNDAY NIGHT...BRINGING OUR NEXT CHANCE OF RAIN AND
POTENTIALLY TEMPERATURES NEAR SEASONAL AVERAGES FOR THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1038 PM CDT TUE AUG 11 2015
MAINLY CLEAR SKIES OVERNIGHT WITH GROUND FOG POSSIBLE
ACROSS NORTHERN WISCONSIN AND ALSO NEAR THE LAKE AND BAY. ANY FOG
SHOULD DISSIPATE BY 14Z WITH SCATTERED TO BROKEN CLOUDS AROUND
7000 TO 8000 FEET WEDNESDAY AFTERNOON. THERE IS A SLIGHT CHANCE OF
A THUNDERSTORM IN THE NORTH IN THE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
642 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 240 PM CDT TUE AUG 11 2015
MUCH OF THE PERIOD LOOKS TO BE QUIET AS HIGH PRESSURE DOMINATES
THE REGION. THIS HIGH IS CURRENTLY CENTERED OVER NEBRASKA WITH THE
RIDGE AXIS EXTENDING NORTH WELL INTO ONTARIO. THE HIGH IS EXPECTED
TO DRIFT EAST TONIGHT AND BE OVER THE AREA SETTING UP THE
POSSIBILITY OF VALLEY FOG. THE 11.12Z NAM FORECAST SOUNDING FOR
KLSE LATE TONIGHT HAS LIGHT WINDS OF 10 KNOTS OR LESS ONLY UP
THROUGH ABOUT 3000 FEET AND WHILE IT SHOWS SATURATION OCCURRING AT
THE SURFACE...IT IMMEDIATELY BECOMES VERY DRY JUST ABOVE THE
SURFACE. THE 11.17Z RAP FORECAST SOUNDING IS EVEN MORE PESSIMISTIC
AS IT DOES NOT SHOW SATURATION OCCURRING AT THE SURFACE AND HAS A
3C TEMP/DEW POINT SPREAD AT 12.11Z. FOR NOW...WILL LEAVE THE
MENTION OF PATCHY VALLEY FOG IN THE FORECAST IN CASE THE NAM
SOUNDING ENDS UP BEING MORE CORRECT BUT WOULD TEND TO THE THINK
WITH THE LACK OF A DEEPER LAYER OF LIGHT WINDS AND SATURATION THAT
THERE WILL BE VERY LITTLE FOG IN THE VALLEYS.
ALL THE 11.12Z MODELS HAVE TRENDED TOWARD KEEPING THE SURFACE
RIDGE OVER THE REGION LONGER THAN PREVIOUS MODEL RUNS. THE UPPER
LEVEL RIDGE AXIS REMAINS OVER THE EASTERN ROCKIES INTO THE
NORTHERN HIGH PLAINS WHICH ENDS UP PUSHING THE SYSTEM CROSSING
CANADA FARTHER TO THE NORTH. THE MODELS CONTINUE TO SHOW A WEAK
SHORT WAVE TROUGH UNDERNEATH THE MAIN SYSTEM BUT THIS SHOULD NOW
PASS EVEN FARTHER TO THE NORTHEAST AND OVER THE NORTHERN GREAT
LAKES FOR WEDNESDAY NIGHT INTO THURSDAY. WITH THE STRONGER LOW
LEVEL RIDGING...THE WEAK COLD FRONT HAS A HARD TIME WORKING SOUTH
AND ALL THE MODELS NOW SHOW THIS REMAINING TO THE NORTH OF THE
AREA WEDNESDAY NIGHT. WITH THE LACK OF SIGNIFICANT FORCING AND THE
FRONT STAYING TO THE NORTH...HAVE REMOVED THE RAIN CHANCES FOR
WEDNESDAY NIGHT.
THERE IS STILL A TREND FOR THE UPPER LEVEL HEIGHTS TO LOWER SOME
THURSDAY INTO THURSDAY NIGHT AS THE UPPER LEVEL RIDGE SHIFTS
SLIGHTLY TO THE WEST. THIS MAY ALLOW A SHORT WAVE TROUGH TO TOP
THE RIDGE AXIS AND THEN SLIDE SOUTHEAST ACROSS THE REGION. IF THE
11.12Z GFS IS CORRECT...THIS WAVE COULD PRODUCE SOME MODERATE PV
ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION.
WHAT LOW LEVEL MOISTURE TRANSPORT THERE IS LOOKS TO WRAP AROUND
THE LOW LEVEL RIDGE AND ACTUALLY COME BACK INTO THE AREA FROM THE
NORTHWEST. OVERALL...THE SIGNAL LOOKS PRETTY WEAK FOR RAIN AS THE
FRONT TRIES TO PUSH INTO THE REGION AND BOTH THE NAM AND 11.12Z
ECMWF KEEP THE AREA DRY WITH ANY RAIN OFF TO THE EAST. THE GFS
CONTINUES TO BE THE MOST ROBUST WITH RAIN AND WILL HONOR ITS
SOLUTION WITH SOME 20 TO 30 PERCENT RAIN CHANCES.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 240 PM CDT TUE AUG 11 2015
THERE COULD BE SOME LINGERING RAIN CHANCES ACROSS THE EAST INTO
FRIDAY FROM THIS SYSTEM...OTHERWISE IT LOOKS TO BE DRY THROUGH
SATURDAY NIGHT. THE RIDGE AXIS IS THEN EXPECTED TO GET FLATTENED
WITH A NEARLY ZONAL FLOW OVER THE UPPER MIDWEST AS A POSITIVE TILT
SYSTEM MOVES ACROSS SOUTHERN CANADA. THE CONCERN WITH THIS SYSTEM
IS HOW FAR SOUTH WILL THE TAIL OF THE SHORT WAVE TROUGH EXTEND.
THE GFS AND 11.12Z GEM ESSENTIALLY SHOW THIS SYSTEM STAYING WELL
TO THE NORTH WHILE THE ECMWF IS STRONGER WITH THE TAIL END OF THE
SYSTEM AND BRINGS A DECENT SECONDARY SHORT WAVE TROUGH ACROSS
SUNDAY AND SUNDAY NIGHT. A COLD FRONT SHOULD GET PUSHED INTO THE
AREA WITH THIS SYSTEM AND ALL THE MODELS AT LEAST SHOW SOME RAIN
CHANCES WITH THE FRONT WITH THE ECMWF HAVING THE MOST AND FOR NOW
WILL SHOW SOME 30 TO 40 PERCENT CHANCES SUNDAY AND SUNDAY NIGHT.
THE ECMWF PUSHES THE FRONT COMPLETELY THROUGH THE AREA WITH HIGH
PRESSURE BUILDING IN FOR THE START OF NEXT WEEK. HOWEVER...THE GFS
HANGS THE FRONT UP OVER THE AREA AND WOULD SUGGEST THERE WOULD BE
SOME ADDITIONAL RAIN CHANCES MONDAY INTO TUESDAY. WITH THE
UNCERTAINTY ON THAT SECONDARY SHORT WAVE TROUGH...WILL HONOR THE
GFS SOLUTION WITH SOME RAIN CHANCES FOR MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 642 PM CDT TUE AUG 11 2015
LATEST HIGH RESOLUTION FORECAST GUIDANCE SUGGESTS A LIGHT WIND
(LESS THAN 10 KTS) LAYER BETWEEN 3500 AND 4500 FT DEEP BY 12.10Z.
HOWEVER...THE MOISTURE PROFILE THROUGH THAT LAYER IS QUITE DRY AND
NEVER SATURATES AT THE SURFACE. IN ADDITION...11.23Z KLSE
OBSERVATION HAD A DEW POINT DEPRESSION OF 26 DEGREES. FOR SURE...
SKIES WILL BECOME CLEAR OVERNIGHT WITH LIGHT AND VARIABLE IF NOT
CALM SURFACE WIND. HOWEVER...THE DEGREE AND DEPTH OF MOISTURE IS
QUESTIONABLE. WILL MAINTAIN CONTINUITY WITH 11.18Z TAFS FOR NOW...
BUT MAY BE ABLE TO REMOVE STRATUS DECK AT KLSE AND MVFR VISIBILITYAT
KRST WITH 12.06Z TAFS IF BOUNDARY LAYER DOES NOT BECOME MORE MOIST
AFTER SUNSET.
BESIDES THE FOG CONCERN WEDNESDAY MORNING...EXPECT VFR CONDITIONS
THROUGH THE PERIOD WITH LIGHT AND VARIABLE WINDS OVERNIGHT
INCREASING SLIGHTLY AND SHIFTING TO THE SOUTHWEST ON WEDNESDAY.
THERE COULD ALSO BE SOME SCATTERED CUMULUS WEDNESDAY AFTERNOON IN
THE 3000 TO 4000 FT AGL LAYER.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
626 PM CDT TUE AUG 11 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM HUDSON BAY TO THE SOUTHERN GREAT PLAINS
EARLY THIS AFTERNOON. DIURNAL CU POPPED BY 15-16Z AND SPREAD SOUTH
TO COVER SCT-BKN CONDITIONS ACROSS MUCH OF THE STATE. A SHORTWAVE
CURRENTLY OVER WESTERN LAKE SUPERIOR WILL MOVE ACROSS NORTHEAST
WISCONSIN LATE IN THE DAY AND MAY PROLONG SCT CLOUD COVER INTO THIS
EVENING. OTHERWISE...THE MAIN FOCUS INCLUDES THUNDERSTORM POTENTIAL
FROM MID-LEVEL WARM ADVECTION FOR WEDNESDAY. SCATTERED
THUNDERSTORMS OCCURRED EARLIER TODAY OVER THE LAKE WINNIPEG REGION
IN THIS WARM ADVECTION ZONE.
TONIGHT...HIGH PRESSURE WILL SLIDING SOUTHEAST ACROSS THE WESTERN
GREAT LAKES WHILE A SHORTWAVE EXITS NORTHEAST WISCONSIN DURING THE
EVENING. THE SHORTWAVE MAY PROLONG SCT CLOUD COVER ACROSS EASTERN
WISCONSIN INTO MID-EVENING...BUT THE REST OF THE AREA SHOULD SEE
CLEARING SKIES WITH LOSS OF DAYTIME HEATING. ONCE THE CLOUDS
DISSIPATE...WILL SEE A PERIOD OF CLEAR CONDITIONS UNTIL LATE IN THE
NIGHT WHEN WARM ADVECTION CLOUDS MOVE SOUTHEAST INTO NORTH-CENTRAL
WISCONSIN. WITH CLOUDS ARRIVING LATE...DO NOT THINK FOG WILL BECOME
TOO BIG OF AN ISSUE. LOWS MAINLY IN THE LOWER TO MIDDLE 50S.
WEDNESDAY...WARM ADVECTION WILL CONTINUE ACROSS THE REGION. THE
BAND OF ASSOCIATED MID-CLOUDS WILL PROCEED EAST ACROSS THE FORECAST
AREA DURING THE MORNING AND THEN EXIT NORTHEAST WI AROUND MID-
AFTERNOON. SOME ELEVATED INSTABILITY GRAZES NORTHERN WISCONSIN
DURING THIS TIME...ALONG WITH MID-LEVEL FGEN ON THE NOSE OF A LLJ.
THOUGH MOISTURE IS NOT PLENTIFUL...NOT COMFORTABLE GOING DRY IN THIS
SCENARIO. SO WILL SHOW 20-30 PCT CHANCE OF RAIN ACROSS FAR N-C AND
PARTS OF NORTHEAST WI. THE REST OF THE AREA SHOULD SEE A PERIOD A
PARTLY/MOSTLY CLOUDY SKIES. HIGHS WARMING A COUPLE DEGREES...WITH
READINGS RANGING FROM THE UPPER 70S TO MID 80S.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 242 PM CDT TUE AUG 11 2015
WITH AMPLIFICATION OF THE WESTERN RIDGE EXPECTED THE REST OF THIS
WEEK...OUR AREA WILL CONTINUE TO FALL UNDER NORTHWEST FLOW.
DESPITE THAT...ABOVE NORMAL HEIGHTS AND WARM AIR ADVECTION FROM
THE WEST SHOULD KEEP TEMPERATURES ABOVE NORMAL...PERHAPS EVEN
SIGNIFICANTLY SO.
THE MAJOR FORECAST CHALLENGE REMAINS PRECIPITATION CHANCES FROM
WEDNESDAY NIGHT THROUGH THE WEEKEND. THOUGH THE GENERAL IDEA OF
MULTIPLE WEAK SHORTWAVE TROUGHS AND AT TIMES ASSOCIATED FRONTS
REMAINS SOLID...THE EXACT DETAILS REMAIN A BIT MUDDY. WEDNESDAY
NIGHT SEEMS PARTICULARLY CHALLENGING AS MANY INGREDIENTS ARE
PRESENT...BUT IN A DISJOINTED MANNER THAT DON`T ENTIRELY SUGGEST
STRONG POTENTIAL FOR CONVECTION. A THETA-E GRADIENT NOSES THROUGH
THE REGION EARLIER IN THE DAY...AND A MIDLEVEL VORT MAX SWINGS
THROUGH IN THE EVENING ALONG WITH MODEST INSTABILITY AND SHEAR BUT
LACKING ANY SIGNIFICANT TRIGGERING MECHANISM. IN THE OVERNIGHT
HOURS TOWARDS DAYBREAK...COULD BEGIN TO SEE INFLUENCE FROM AN
APPROACHING COLD FRONT. THOUGH I GET THE FEELING THAT THE EVENING
WILL END UP DRY...CAN`T RULE DEVELOPMENT OUT AND SO SOME LOW-END
POPS REMAIN. POPS THEN BEGIN TO INCREASE TOWARDS MORNING AS THE
FRONT DRAWS NEARER IN DEFERENCE TO THE MORE PROGRESSIVE ELEMENTS
OF THE MODEL ENVELOPE.
THURSDAY PERHAPS SHOWS THE BEST POTENTIAL FOR STORMS AS THE FRONT
SWINGS INTO THE AREA ALONG WITH BETTER INSTABILITY. INDEED...THE
GFS SUGGESTS UP TO 3000 J/KG OF CAPE IN THE NORTHWOODS LATE
THURSDAY AFTERNOON INTO THE EVENING AND MARGINAL 30 KNOT SHEAR.
FORECAST SOUNDINGS AGAIN SHOW CAPPING THURSDAY WHICH COULD BE
RESTRICTIVE...BUT THE FRONT SHOULD AID IN OVERCOMING THAT...AS
LONG AS IT MOVES IN QUICKLY ENOUGH. STEEP TEMPERATURE-DEWPOINT
SPREADS AT THE SURFACE AND A STRONGLY MIXED BOUNDARY LAYER CREATE
THE POTENTIAL FOR INVERTED-V TYPE SOUNDINGS. IF CONVECTION BECOMES
STRONG ENOUGH...THERE COULD BE SOME GUSTY WINDS TO BE FOUND.
GUIDANCE DOES BEGIN TO DIVERGE BUT...EITHER DUE TO SLOWER TIMING
IN SOME MODELS...AND STALLING THE FRONT OUT OVER SOUTHERN
WISCONSIN IN OTHERS...THE CHANCE FOR LINGERING RAIN DRAGS INTO
FRIDAY IN CENTRAL AND EAST CENTRAL WISCONSIN.
WE SHOULD THEN SEE A DRYING TREND THROUGH MOST OF THE WEEKEND AS
RIDING BUILDS INTO THE REGION AND TEMPERATURES ONLY A BIT COOLER
BEHIND THE WEAK FRONT. FINALLY...THE MIDLEVEL RIDGE WILL BEGIN TO
FLATTEN AS AN UPPER TROUGH SWINGS THROUGH CANADA. THE COLD FRONT
ASSOCIATED WITH ITS SURFACE REFLECTION LOOKS TO COME THROUGH THE
AREA SUNDAY NIGHT...BRINGING OUR NEXT CHANCE OF RAIN AND
POTENTIALLY TEMPERATURES NEAR SEASONAL AVERAGES FOR THE FIRST PART
OF NEXT WEEK.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 626 PM CDT TUE AUG 11 2015
GREAT FLYING WEATHER THIS EVENING AND IN MOST PLACES
THROUGH THE NIGHT. THERE IS A CHANCE OF GROUND FOG IN NORTHCENTRAL
WISCONSIN AND ALSO NEAR THE LAKE AND BAY LATE TONIGHT. ANY GROUND
FOG THAT FORMS WILL DISSIPATE BY 14Z WITH VFR CONDITIONS EXPECTED
WEDNESDAY. THERE IS A SMALL CHANCE OF A THUNDERSTORM ACROSS THE
NORTH IN THE LATE MORNING OR AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A DIFFUSE
SURFACE COLD FRONT SHIFTING SOUTH OVER SOUTHWEST TO EAST-CENTRAL
WISCONSIN EARLY THIS AFTERNOON. BUT BEHIND THE FRONT..INSTABILITY
HAS INCREASED TO OVER 800 J/KG ML CAPE AND TEMPERATURES HAVE
SURPASSED THE CONVECTIVE TEMP. WEAK CONVERGENCE IS ALSO DEVELOPING
ALONG THE BAY AND LAKE BREEZES. SO THINK WILL SEE SCATTERED SHOWERS
AND STORMS DEVELOP OVER EASTERN WI FOR THE REST OF THE AFTERNOON.
OTHER SHOWERS ARE POPPING UP OVER NORTHEAST MINNESOTA ASSOCIATED
WITH A SHORTWAVE TROUGH. THE TAIL END OF THE SHORTWAVE WILL
APPROACH FAR N-C WI LATE THIS AFTERNOON OR EARLY THIS EVENING...SO
WILL HAVE TO MONITOR FOR A SHOWER ADDITION TO THE FORECAST.
FORECAST CONCERNS INCLUDE PRECIP TRENDS...FOLLOWED BY CLOUD AND TEMP
TRENDS.
TONIGHT...RATHER DIFFUSE SURFACE COLD FRONT WILL SETTLE WELL SOUTH
OF THE REGION. BUT THE HIGHER RES MODELS CONTINUE TO POINT TOWARDS
WEAK LOW LEVEL CONVERGENCE CONTINUING INTO THE EVENING OVER EASTERN
WI...WITH SOME EXTRA UPPER LEVEL SUPPORT ARRIVING VIA THE SHORTWAVE
OVER WESTERN ONTARIO. INSTABILITY WEAKENS WITH LOSS OF DAYTIME
HEATING...BUT SOME DOES LINGER OVER EAST-CENTRAL WI THROUGH ABOUT
MID-EVENING. SO WILL KEEP AN ISOLATED SHOWER MENTION THROUGH ABOUT
03Z. THEREAFTER...SHOULD SEE SOME CLEARING TAKE PLACE OVER CENTRAL
AND NORTHEAST WISCONSIN. BUT STRATO-CU FROM NORTHERN MINNESOTA AND
ONTARIO WILL MAKE A RUN AT N-C WISCONSIN BY MID TO LATE EVENING.
DEWPOINTS WILL GRADUALLY FALL THROUGH THE NIGHT WHICH SHOULD SET UP
COOLER NIGHT TIME LOWS. LOWS FROM THE MID 50S NORTH TO LOW 60S SOUTH.
TUESDAY...HIGH PRESSURE WILL GRADUALLY BE BUILDING INTO THE REGION.
SHOULD SEE PLENTY OF DIURNAL CU POP WITH HEATING OF THE DAY BY LATE
MORNING BASED ON UPSTREAM OBS. ANY LOW STRATUS OVER N-C WI SHOULD
ALSO TURN INTO A CU FIELD...BUT NO SHOWER ACTIVITY IS EXPECTED.
HIGHS RANGING FROM THE LOW 70S NORTH TO AROUND 80 SOUTH.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 246 PM CDT MON AUG 10 2015
MAJOR FEATURE DOMINATING THE CONUS THIS WEEK IS LARGE MID-LEVEL
RIDGE OVER THE CENTRAL PLAINS...EXPECTED TO AMPLIFY FURTHER AND
DRIFT BACK TOWARDS THE MOUNTAIN WEST. THIS WILL KEEP...AND EVEN
ENHANCE NORTHWEST FLOW ALOFT OVER OUR AREA. DESPITE THE NORTHWEST
FLOW...THE SHEER AMPLITUDE OF THE RIDGE WILL RESULT IN ABOVE
NORMAL HEIGHTS. PAIRED WITH A WEAK 850 MB HIGH OVER THE MIDDLE
MISSISSIPPI VALLEY ALLOWING FOR HIGHER TEMPS AT THAT
LEVEL...EXPECT HIGHS IN THE SECOND HALF OF THE WEEK TO BE NEAR
NORMAL OR ABOVE NORMAL. POTENTIAL FOR PRECIPITATION WILL COME
FROM MULTIPLE WEAK TROUGHS RIDING DOWN THE EAST SIDE OF THE RIDGE
STRAIGHT INTO THE WEEKEND.
A SUBTLE 500 MB VORT MAX LOOKS TO SCOOT NORTHEAST OF THE AREA
THROUGH THE UPPER PENINSULA WEDNESDAY AFTERNOON AND EVENING. AT
THE TIME...BOTH THE GFS AND EURO SUGGEST ABOUT 1000 J/KG OF CAPE
AND ABOUT 30 KNOTS OF SHEAR IN THE MICHIGAN BORDER REGION.
BUT...DEEP TEMPERATURE-DEWPOINT SPREADS AND THE LACK OF TRIGGERING
MECHANISM MAKE IT DIFFICULT TO SEE CONVECTIVE INITIATION EVEN
WITHOUT MUCH CAPPING PRESENT. STILL...BUFKIT TEMPS ARE VERY NEAR
THE CONVECTIVE TEMP SO STORMS CAN`T BE RULED OUT IN NORTH CENTRAL
AND FAR NORTHEAST WISCONSIN...AND THREW SLIGHT CHANCE POPS IN
THERE.
PERHAPS MORE SIGNIFICANT PRECIP POTENTIAL COMES THURSDAY INTO
FRIDAY...AS A WEAK COLD FRONT WILL CROSS THE REGION. AS WITH
WEDNESDAY...THERE APPEARS TO BE MODEST INSTABILITY AND SHEAR FOR
SOME STRONG STORMS. AGAIN...LOW LEVEL MOISTURE APPEARS TO BE A
LIMITING FACTOR...BUT AT LEAST ON THIS DAY WE HAVE THE FRONT AS A
FOCUSING MECHANISM. GIVEN SOME CAPPING PRESENT...THERE`S
SIGNIFICANT UNCERTAINTY ABOUT HOW MUCH COVERAGE WILL BE SEEN IN
ANY DEVELOPMENT. BUT HAVE HIGHER POPS THAN WEDNESDAY THANKS TO
THAT FRONTAL PRESENCE.
FINALLY...AFTER A MOSTLY DRY WEEKEND THANKS TO THE UPPER RIDGE
TILTING EASTWARD TOWARDS OUR AREA...WE`LL LOOK FOR TROUGHING OVER
CANADA TO BEAT DOWN THAT NORTHWARD EXTENT OF THE RIDGE AND PROVIDE
ANOTHER SHOT AT SHOWERS AND STORMS LATE SUNDAY AFTERNOON THROUGH
SUNDAY NIGHT ALONG A COLD FRONT.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1158 AM CDT MON AUG 10 2015
A MOISTURE-LADEN AIRMASS WILL BE SLOW TO MOVE OUT BEHIND
A WEAK COLD FRONT THIS AFTERNOON. THE HIGH HUMIDITY WILL PRODUCE
SCT TO BKN MVFR CONDITIONS AT TIMES...MAINLY OVER EASTERN WISCONSIN.
WITH LAKE BREEZE DEVELOPMENT THIS AFTERNOON...EASTERN WISCONSIN
COULD ALSO SEE SCT SHOWERS AND ISOLATED TSTORMS POP UP FROM MID-
AFTERNOON THROUGH ABOUT MID-EVENING. COOLER AND DRIER AIR WILL
FINALLY PUSH INTO THE REGION TONIGHT...AT THE EXPENSE OF LOW STRATUS
PUSHING SOUTH INTO N-C WISCONSIN LATE. WITH DAYTIME MIXING...THINK
ANY LOW STRATUS WILL BECOME MORE SCATTERED IN NATURE AROUND MIDDAY
TUE.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......LUCHS
AVIATION.......MPC
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1046 AM CDT MON AUG 10 2015
.UPDATE...
A 500MB TROUGH WILL SWING THROUGH THE GREAT LAKES REGION TODAY AND
TONIGHT. VORTICITY ADVECTION WITH AN EMBEDDED SHORTWAVE WILL LEAD TO
SCATTERED SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS SOUTH CENTRAL
AND SOUTHEAST WI NOW THROUGH 3 PM. THE 14Z HRRR RUN IS SHOWING THIS
BUT LOOKS A LITTLE OVERDONE. RADAR IS ALREADY SHOWING A FEW MORE
SHOWERS DEVELOPING ALREADY. THERE IS MODERATE INSTABILITY IN PLACE
OVER SOUTHERN WI WITH UP TO 1000 J/KG OF SURFACE-BASED CAPE. SHEAR
IS MINIMAL... SO NOT EXPECTING ANY SEVERE THUNDERSTORMS- JUST
SCATTERED STORMS WITH HEAVY DOWNPOURS. STORMS ARE SLOW-MOVING SO UP
TO A QUARTER INCH OF RAIN WOULD BE POSSIBLE WITH A SINGLE STORM.
THE SURFACE COLD FRONT ALREADY WENT THROUGH THE AREA EARLY THIS
MORNING... BUT THE UPPER LEVEL COLD FRONT WILL NOT CLEAR SOUTHERN WI
UNTIL LATE TONIGHT. THERE IS ONE MORE SHORTWAVE TO CROSS THE AREA
OVERNIGHT... BUT THAT SHOULD COME THROUGH DRY. THE COLUMN WILL BE
DRYING OUT AND IT IS ALSO COMING THROUGH DURING A DIURNALLY
UNFAVORABLE TIME OF DAY FOR CONVECTION.
&&
.AVIATION/18Z TAFS/...
SCATTERED SHOWERS AND THUNDERSTORMS ARE DEVELOPING ACROSS SOUTH
CENTRAL AND SOUTHEAST WI LATE THIS MORNING AND WILL PERSIST THROUGH
MID AFTERNOON. THESE ARE DUE TO THE PASSAGE OF AN UPPER LEVEL COLD
FRONT AND THE DEVELOPMENT OF A LAKE BREEZE FRONT. AREAS OF MVFR CIGS
WILL BE POSSIBLE BY THE MIDDLE TO LATE MORNING WITH THE INITIAL
CUMULUS DEVELOPMENT BUT LIFT TO 3.5-5.0 KFT THROUGH THE AFTERNOON.
COLD AND DRY AIR ADVECTION TO PREVAIL TNT ON NLY WINDS SO FOG
POTENTIAL IS VERY LOW.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
TUESDAY THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1154 PM CDT SUN AUG 9 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A COLD
FRONT STRETCHING FROM SOUTHWEST MINNESOTA TO THE WESTERN UPPER
PENINSULA. THIS FRONT HAS BEEN MOSTLY INACTIVE SO FAR
TODAY...OUTSIDE OF A FEW SHOWERS OVER VILAS COUNTY EARLY THIS
MORNING. LOW STRATUS OVER NORTHERN WISCONSIN HAVE HELD BACK TEMPS
SOMEWHAT...WHICH IS KEEPING INSTABILITY LIMITED TO UNDER 800 J/KG SO
FAR THIS AFTERNOON. THE STRATUS IS SHOWING NO SIGNS OF BREAKING UP
EITHER. BIGGER CONCERNS REVOLVE AROUND THE SHOWERS AND
THUNDERSTORMS MOVING INTO WESTERN WISCONSIN ASSOCIATED WITH A
SHORTWAVE IMPULSE. THUNDERSTORMS ARE EXPANDING WITHIN THE
INSTABILITY AXIS OVER NORTHWEST WISCONSIN...AND A ROUGH TIMING SHOWS
STORMS MOVING INTO NORTH-CENTRAL WISCONSIN IN THE 3-5PM RANGE. DUE
TO THE LIMITED INSTABILITY...STILL THE SEVERE THREAT IS RATHER LOW.
BUT SMALL HAIL AND GUSTY STRAIGHT LINE WINDS WILL BE POSSIBLE.
FORECAST CONCERNS REVOLVE AROUND THUNDERSTORM POTENTIAL.
TONIGHT...THE COLD FRONT WILL REMAIN NEARLY STATIONARY FOR THE REST
OF THE AFTERNOON...AND THEN SHIFT SOUTHEAST AS THE SHORTWAVE IMPULSE
MOVES ACROSS THE AREA THIS EVENING. SHOWERS AND THUNDERSTORMS NOW
LOOK LIKELY ACROSS MOST OF THE AREA THIS EVENING...EXCEPT FOR MAYBE
THE SOUTHERN TIER. HAVE INCREASED PRECIP CHANCES INTO THE LIKELY
RANGE...AS THE SHORTWAVE SHOULD BE ABLE TO INTERACT WITH SOME OF
LINGERING DAYTIME INSTABILITY. THE RAINFALL SHOULD HELP GIVE SOME
SOUTHEAST PUSH TO THE COLD FRONT WHICH WILL MOVE INTO EAST-CENTRAL
WISCONSIN LATE. WITH THE RAINFALL AND FRONT NEARBY...THINK LOW
STRATUS AND/OR FOG WILL REDEVELOP AFTER MIDNIGHT. SOME DENSE FOG
LIKE EARLY THIS MORNING IS POSSIBLE IN SPOTS.
MONDAY...THE FRONT DOES NOT MAKE MUCH PROGRESS SOUTHWARD...LEAVING
NORTHEAST WISCONSIN IN CLOSE PROXIMITY TO THE FRONT. THOUGH HAVE
SOME CONCERN THAT TONIGHTS RAIN WILL PUSH THE FRONT SOUTH OF THE
AREA...LEFT A CHANCE OF STORMS IN THE FORECAST DURING THE AFTERNOON
OVER THE EAST. NO SEVERE STORMS ARE EXPECTED DUE TO MEAGER 0-6KM
SHEAR OF 10 KTS. HIGHS TO RANGE FROM THE MID 70S TO LOW 80S.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 214 PM CDT SUN AUG 9 2015
A TRANSITION IN THE UPPER LEVEL FLOW IS EXPECTED STARTING
TUESDAY...WHEN HIGH PRESSURE WILL STRENGTHEN OVER THE ROCKIES IN A
BLOCKING PATTERN THAT WILL KEEP THE NORTHEAST U.S. UNDER A LOW
PRESSURE TROUGH AND WISCONSIN UNDER A NORTHWEST FLOW. THIS
SCENARIO WILL PRODUCE DRIER CONDITIONS IN GENERAL FOR NORTHEAST
WISCONSIN...ALTHOUGH MODELS AGREE ON A CHANCE FOR PRECIPITATION
LATER IN THE WORK WEEK AS A WEAK COLD FRONT SWEEPS DOWN ON THE
NORTHWEST FLOW OUT OF CANADA.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1154 PM CDT SUN AUG 9 2015
A WEAK COLD FRONT WILL MOVE ACROSS THE REGION
OVERNIGHT ACCOMPANIED BY SCATTERED SHOWERS. THERE ARE A LOT OF
MIDDLE CLOUDS WHICH MAY BREAK UP ENOUGH FOR LOW CLOUDS OR FOG TO
FORM LATER TONIGHT IN SOME AREAS. THE FOG WOULD END BY 15Z MONDAY
WITH VFR CONDITION EXPECTED BY AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......ML
AVIATION.......RDM
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
606 PM MDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 558 PM MDT TUE AUG 11 2015
OUR GRIDDED FORECASTS IN NICE SHAPE. WE MASSAGED THE EVENING
SHOWER AND THUNDERSTORMS CHANCES BASED ON AREAL COVERAGE
OCCURRING.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY NIGHT)
ISSUED AT 237 PM MDT TUE AUG 11 2015
TONIGHT:
LATEST RADAR LOOP WAS SHOWING VERY MINIMAL COVERAGE IN SHOWERS AND
THUNDERSTORMS THIS AFTERNOON WITH THE BULK OF THEM DEVELOPING OVER
THE LARAMIE RANGE. WOULD EXPECT THIS TREND TO CONTINUE DURING THE
REMAINDER OF THE AFTERNOON. ANOTHER CONCERN IS THE POTENTIAL FOR
PATCHY FOG DEVELOPMENT IN THE SOUTHERN PANHANDLE TONIGHT. LATEST
SURFACE ANALYSIS WAS SHOWING A GOOD FETCH OF LOW LEVEL MOISTURE
BETWEEN THE SURFACE HIGH IN THE PLAINS AND THE LEE TROF EAST OF
THE LARAMIE RANGE. THE NAM BUFKIT ANALYSIS WAS SHOWING THE
BOUNDARY LAYER RH FIELDS INCREASING AFTER MIDNIGHT IN THE SOUTHERN
PANHANDLE UNDERNEATH THE LOW LEVEL INVERSION. WE WENT AHEAD AND
INTRODUCED PATCHY FOG IN THIS REGION TO REFLECT THIS POTENTIAL.
WEDNESDAY-WEDNESDAY NIGHT:
A WEAK POTENTIAL VORTICITY ANOMALY IS EXPECTED TO MOVE INTO THE
SOUTHWEST PORTION OF THE FORECAST AREA ON WEDNESDAY MORNING WITH
THIS WAVE SPREADING WEST TO EAST DURING THE COURSE OF THE DAY.
IN ADDITION...THERE IS DECENT MOISTURE TRANSPORT AROUND 310K WITH
THE BEST LIFT IN THE NORTHERN HALF OF THE AREA. ANY CONVECTION
THAT DOES DEVELOP OVER THE LARAMIE RANGE EARLY WEDNESDAY AFTERNOON
SHOULD GENERALLY SPREAD EAST-NORTHEAST DURING THE COURSE OF THE
DAY. THE BEST INSTABILITY EXISTS OVER THE PANHANDLE...BUT THE
SHEAR IS QUITE LIMITED SO NOT EXPECTING ANYTHING SEVERE. THE
CONVECTION SHOULD BEGIN TO DIMINISH THE EVENING AND OVERNIGHT DUE
TO LIMITED SHEAR.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 237 PM MDT TUE AUG 11 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 450 PM MDT TUE AUG 11 2015
GOING TO CONTINUE CHANCES FOR IFR/LIFR CONDITIONS AT KCYS...KBFF
AND KSNY TONIGHT WITH SOUTHEAST WINDS CONTINUING. SUPPORTED BY
LATEST SREF AND HRRR FORECASTS AS WELL. COULD LAST ALL MORNING IF
THERE IS NO CONVECTION TO BREAK UP THE LOW LEVEL MOISTURE. WILL
TRY TO NAIL DOWN TIMING A LITTLE BETTER WITH THE 06Z TAF SUITE.
&&
.FIRE WEATHER...
ISSUED AT 237 PM MDT TUE AUG 11 2015
ONLY FIRE WEATHER CONCERN WILL BE THE LIGHTNING POTENTIAL OVER
THE MOUNTAINS DURING THE NEXT COUPLE OF DAYS WHICH COULD IGNITE A
FIRE START. OTHERWISE...RELATIVE HUMIDITIES WILL BE MARGINAL 20
TO 30 PERCENT WITH WIND SPEEDS POSSIBLY REACHING 20 TO 25 MPH IN
AREAS WEST OF THE LARAMIE RANGE WEDNESDAY AFTERNOON.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...RUBIN
SHORT TERM...REC
LONG TERM...JG
AVIATION...GCC
FIRE WEATHER...REC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
442 PM MDT MON AUG 10 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
WE ARE STARTING TO SEE A FEW BUILDUPS ACROSS THE SOUTHERN LARAMIE
RANGE IN WYOMING AS WELL AS IN A ZONE OF DIFFERENTIAL HEATING ON
THE NORTH SIDE OF THE NORTH PLATTE RIVER VALLEY ACROSS THE
NEBRASKA PANHANDLE NORTH OF SCOTTSBLUFF. DONT THINK MOST STORMS
WILL GET OVERLY ROWDY THIS AFTERNOON AND EVENING...ALTHOUGH WITH
SBCAPES RUNNING IN THE 1200-1600 J/KG RANGE OVER THE PANHANDLE WE
COULD SEE A FEW STRONGER UPDRAFTS TO SUPPORT ISOLATED
STRONG/BRIEFLY MARGINALLY SEVERE STORMS...ALTHOUGH TYPICAL OF
AUGUST MIDLEVELS ARE FAIRLY WARM. MOST OF THE CONVECTION IS
EXPECTED TO FIRE ALONG AND JUST EAST OF THE LARAMIE RANGE THIS
AFTERNOON WITH ISOLATED STORMS EXPECTED THROUGH MID EVENING OVER
THE PANHANDLE.
RATHER AMPLIFIED UPPER RIDGE EXTENDS NORTH ACROSS THE CENTRAL AND
NORTHERN ROCKIES WITH OUR FORECAST AREA SEEING A GRADUAL INCREASE
IN MIDLEVEL MOISTURE FROM THE SOUTHWEST THROUGH MID WEEK. WILL SEE
SCATTERED STORMS TOMORROW AFTERNOON FIRE OVER THE SIERRA MADRE,
SNOWY AND SOUTHERN LARAMIE RANGE WITH ISOLATED STORMS EAST ONTO
THE PLAINS. BOTH THE GFS AND THE NAM SUPPORT THE NOTION OF A
SHORTWAVE RIDING NORTHEAST ACROSS OUR AREA WEDNESDAY AND THAT WILL
SUPPORT AN INCREASE IN POPS FOR WEDNESDAY AFTERNOON...ESPECIALLY
OUT WEST ALONG AND WEST OF THE LARAMIE RANGE WITH ISOLATED POPS
FARTHER EAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH MONDAY)
ISSUED AT 242 PM MDT MON AUG 10 2015
FAIRLY STAGNANT PATTERN EXPECTED ACROSS THE CWA WEDS NIGHT INTO
SATURDAY WITH A LARGE UPPER RIDGE HOLDING ACROSS THE REGION ATOP
AN UPPER HIGH THAT WILL DRIFT SLOWLY WESTWARD ACROSS THE SOUTHERN
ROCKY MTNS. TEMPS QUITE WARM THURSDAY THROUGH SATURDAY UNDER A MID
LEVEL THERMAL RIDGE WITH 700MB TEMPS WARMING TO ABOUT 14-16C. THIS
WILL ALLOW TEMPS TO WARM INTO THE 90S OVER LOWER ELEVATIONS. WEAK
IMPULSES WILL DRIFT THROUGH THE UPPER RIDGE AND ACROSS THE REGION
AND SHOULD SET OFF ISOLATED CONVECTION FROM TIME TO TIME.
INDIVIDUAL WAVES HARD TO TIME SO TAILORED POPS TO FIT WHAT SEEMED
TO BE THE BETTER CHANCES.
SOME CHANGES MAY ARRIVE IN THE SUNDAY/MONDAY TIME PERIOD AS AN
UPPER SHORTWAVE MOVES ACROSS SRN CANADA. THIS SHOULD PUSH A COOL
FRONT ACROSS THE CWA EARLY SUNDAY BEFORE WASHING BACK OUT EAST
MONDAY. PCPN CHANCE STILL NOT TOO IMPRESSIVE HOWEVER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 439 PM MDT MON AUG 10 2015
THERE IS THE POSSIBILITY OF LOWER FLIGHT CONDITIONS FOR SOME
AIRPORTS IN THE SOUTHERN PANHANDLE AND HERE AT CHEYENNE. LATEST
ALTERNATIVE HRRR AND SREF GUIDANCE IS SHOWING KSNY...KCYS AND
POSSIBLY KBFF GOING DOWN IN FOG AND STRATUS AFTER 09Z OR SO
TUESDAY MORNING. WILL TRY TO NARROW DOWN TIMING AND AIRPORTS ON
THE 06Z TAFS. BEST CHANCES LOOK TO BE HERE AT KCYS OVERNIGHT.
SOUTHEAST UPSLOPING WINDS TO CONTINUE THROUGH LATE MORNING TUESDAY
BEFORE TURNING MORE WESTERLY.
&&
.FIRE WEATHER...
ISSUED AT 242 PM MDT MON AUG 10 2015
STILL EXPECTING NO MAJOR FIRE WEATHER CONCERNS THROUGH AT LEAST
WEDNESDAY WITH WIND GUSTS (AWAY FROM THUNDERSTORMS) EXPECTED TO
REMAIN BELOW 25 MPH AND HUMIDITIES AT OR ABOVE 20 PERCENT FOR MOST
LOCATIONS. WE WILL SEE ISOLATED TO SCATTERED THUNDERSTORMS THROUGH
MID WEEK IN THE AFTERNOON AND EARLY EVENING HOURS...WITH THE MAIN
THREATS FROM THESE BEING CLOUD TO GROUND LIGHTNING AND
GUSTY/ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...JG
LONG TERM...RE
AVIATION...GCC
FIRE WEATHER...JG
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1120 AM MDT MON AUG 10 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
TRANQUIL WEATHER CONDITIONS TO START THE FORECAST PERIOD WITH MOSTLY
CLEAR SKIES IN PLACE ACROSS THE REGION. THERE IS STILL THE POTENTIAL
FOR PATCHY FOG TO DEVELOP ALONG AND EAST OF THE LARAMIE RANGE GIVEN
WEAK UPSLOPE AND EXCELLENT LOW-LEVEL SATURATION INDICATED BY NAM/GFS
BUFKIT SOUNDINGS. THE HRRR HAS NOT BEEN OVERLY SUPPORTIVE...BUT WILL
MAINTAIN MENTION OF FOG THROUGH ABOUT 15Z...WHEN BOUNDARY LAYER RHS
SHOULD DECREASE. A STALLED N-S ORIENTED COLD FRONT ALONG THE LARAMIE
RANGE WILL SUPPORT CONTINUED LOW-LEVEL UPSLOPE TODAY. EXPECT SHOWERS
AND THUNDERSTORMS TO DEVELOP OVER THE MOUNTAINS AFTER 21Z...AND MOVE
EAST ONTO THE PLAINS THROUGH THE EVENING. CANNOT ENTIRELY RULE OUT A
STRONGER STORM OR TWO IF THE GFS VERIFIES WITH SBCAPE NEAR 1000 J/KG
ALONG THE I-80 CORRIDOR BETWEEN CYS-SNY...ESPECIALLY GIVEN 0 TO 6 KM
SHEAR IN EXCESS OF 35 KTS. SHOULD NOT BE LOOKING AT ANYTHING SEVERE
THOUGH.
A TYPICAL AUGUST WEATHER PATTERN WILL CONTINUE THROUGH MID WEEK WITH
UPPER-LEVEL RIDGING THE DOMINANT FEATURE. SOUTHWEST FLOW ALOFT WILL
YIELD A PERSISTENT FEED OF MONSOONAL MOISTURE...GIVING WAY TO DAILY
CHANCES FOR CONVECTION GENERALLY ALONG AND WEST OF THE LARAMIE RANGE
ON TUESDAY AND WEDNESDAY AFTERNOONS. A GRADUAL WARMING TREND CAN BE
EXPECTED AS RIDGING STRENGTHENS...AND H7 TEMPS INCREASE TO NEAR +16
DEG C BY 00Z THU. SHOULD SEE MORE WIDESPREAD 90S FOR AFTERNOON HIGHS
BY THE END OF THE PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL HIGH...CENTERED
NEAR THE FOUR CORNERS REGION...DOMINATING THE WEATHER PATTERN LATE
THIS WEEK AND INTO NEXT WEEKEND. THE HIGH SHOWS SOME SIGNS OF
RETROGRADING OR WEAKENING BY NEXT WEEKEND...AS ENERGY FROM THE
NORTHERN PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES.
ANY NOTICEABLE CHANGES TO THE PATTERN ARE NOT EXPECTED TO OCCUR
OVER THE NEXT 7 DAYS THOUGH...SO EXPECTED PERSISTENT SOUTHWEST
FLOW ALOFT AND ADVECTION OF MONSOON MOISTURE LATE THIS WEEK AND
NEXT WEEKEND. HIGH TEMPERATURES WILL BE ABOVE NORMAL THROUGH
SATURDAY WITH READINGS IN THE 80S TO LOW 90S ACROSS MOST OF THE
AREA. PORTIONS OF WESTERN NEBRASKA AND FAR EASTERN WYOMING WILL
LIKELY REACH THE MID TO UPPER 90S ON FRIDAY AS 700MB TEMPERATURES
PEAK BETWEEN 15C TO 18C. WITH PW/S INCREASING TO OVER ONE
INCH ACROSS THE FRONT RANGE...THERE WILL BE PLENTY OF MOISTURE FOR
SHOWERS AND TSTORMS TO DEVELOP OVER THE HIGHER TERRAIN. NOT
CONFIDENT ON THE COVERAGE AT THIS TIME...BUT SOME OF THESE TSTORMS
MAY CONTAIN VERY HEAVY RAINFALL. IN ADDITION...SHOWERS AND TSTORMS
WILL NOT MOVE ALL THAT MUCH THROUGH EACH AFTERNOON. THUS THERE IS
SOME CONCERN FOR FLASH FLOODING. KEPT POP BETWEEN 20 TO 30 PERCENT
FOR THE HIGH VALLEYS AND HIGH PLAINS...WITH VALUES CLOSER TO 50
PERCENT IN THE MOUNTAINS. SEVERE TSTORMS APPEAR UNLIKELY AT THIS
TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1120 AM MDT MON AUG 10 2015
VFR EXPECTED OVER ALL TERMINALS THROUGH THE PERIOD. ISOLATED
SHOWERS A TSTMS POSSIBLE MAINLY OVER THE SE WY MTNS THIS AFTERNOON
INTO EARLY THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 222 AM MDT MON AUG 10 2015
NO MAJOR FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. NON-CRITICAL
CONDITIONS ARE EXPECTED WITH WIND GUSTS EXPECTED TO REMAIN BELOW 25
MPH AND HUMIDITIES GENERALLY ABOVE 20 PERCENT WITH GOOD TO EXCELLENT
RECOVERY OVERNIGHT. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS COULD
OCCUR EACH AFTERNOON THROUGH THE WEEK. THE MAIN HAZARD FROM THESE
STORMS WILL BE GUSTY AND ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...RE
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
418 AM MDT MON AUG 10 2015
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
TRANQUIL WEATHER CONDITIONS TO START THE FORECAST PERIOD WITH MOSTLY
CLEAR SKIES IN PLACE ACROSS THE REGION. THERE IS STILL THE POTENTIAL
FOR PATCHY FOG TO DEVELOP ALONG AND EAST OF THE LARAMIE RANGE GIVEN
WEAK UPSLOPE AND EXCELLENT LOW-LEVEL SATURATION INDICATED BY NAM/GFS
BUFKIT SOUNDINGS. THE HRRR HAS NOT BEEN OVERLY SUPPORTIVE...BUT WILL
MAINTAIN MENTION OF FOG THROUGH ABOUT 15Z...WHEN BOUNDARY LAYER RHS
SHOULD DECREASE. A STALLED N-S ORIENTED COLD FRONT ALONG THE LARAMIE
RANGE WILL SUPPORT CONTINUED LOW-LEVEL UPSLOPE TODAY. EXPECT SHOWERS
AND THUNDERSTORMS TO DEVELOP OVER THE MOUNTAINS AFTER 21Z...AND MOVE
EAST ONTO THE PLAINS THROUGH THE EVENING. CANNOT ENTIRELY RULE OUT A
STRONGER STORM OR TWO IF THE GFS VERIFIES WITH SBCAPE NEAR 1000 J/KG
ALONG THE I-80 CORRIDOR BETWEEN CYS-SNY...ESPECIALLY GIVEN 0 TO 6 KM
SHEAR IN EXCESS OF 35 KTS. SHOULD NOT BE LOOKING AT ANYTHING SEVERE
THOUGH.
A TYPICAL AUGUST WEATHER PATTERN WILL CONTINUE THROUGH MID WEEK WITH
UPPER-LEVEL RIDGING THE DOMINANT FEATURE. SOUTHWEST FLOW ALOFT WILL
YIELD A PERSISTENT FEED OF MONSOONAL MOISTURE...GIVING WAY TO DAILY
CHANCES FOR CONVECTION GENERALLY ALONG AND WEST OF THE LARAMIE RANGE
ON TUESDAY AND WEDNESDAY AFTERNOONS. A GRADUAL WARMING TREND CAN BE
EXPECTED AS RIDGING STRENGTHENS...AND H7 TEMPS INCREASE TO NEAR +16
DEG C BY 00Z THU. SHOULD SEE MORE WIDESPREAD 90S FOR AFTERNOON HIGHS
BY THE END OF THE PERIOD.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 222 AM MDT MON AUG 10 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL HIGH...CENTERED
NEAR THE FOUR CORNERS REGION...DOMINATING THE WEATHER PATTERN LATE
THIS WEEK AND INTO NEXT WEEKEND. THE HIGH SHOWS SOME SIGNS OF
RETROGRADING OR WEAKENING BY NEXT WEEKEND...AS ENERGY FROM THE
NORTHERN PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES.
ANY NOTICEABLE CHANGES TO THE PATTERN ARE NOT EXPECTED TO OCCUR
OVER THE NEXT 7 DAYS THOUGH...SO EXPECTED PERSISTENT SOUTHWEST
FLOW ALOFT AND ADVECTION OF MONSOON MOISTURE LATE THIS WEEK AND
NEXT WEEKEND. HIGH TEMPERATURES WILL BE ABOVE NORMAL THROUGH
SATURDAY WITH READINGS IN THE 80S TO LOW 90S ACROSS MOST OF THE
AREA. PORTIONS OF WESTERN NEBRASKA AND FAR EASTERN WYOMING WILL
LIKELY REACH THE MID TO UPPER 90S ON FRIDAY AS 700MB TEMPERATURES
PEAK BETWEEN 15C TO 18C. WITH PW/S INCREASING TO OVER ONE
INCH ACROSS THE FRONT RANGE...THERE WILL BE PLENTY OF MOISTURE FOR
SHOWERS AND TSTORMS TO DEVELOP OVER THE HIGHER TERRAIN. NOT
CONFIDENT ON THE COVERAGE AT THIS TIME...BUT SOME OF THESE TSTORMS
MAY CONTAIN VERY HEAVY RAINFALL. IN ADDITION...SHOWERS AND TSTORMS
WILL NOT MOVE ALL THAT MUCH THROUGH EACH AFTERNOON. THUS THERE IS
SOME CONCERN FOR FLASH FLOODING. KEPT POP BETWEEN 20 TO 30 PERCENT
FOR THE HIGH VALLEYS AND HIGH PLAINS...WITH VALUES CLOSER TO 50
PERCENT IN THE MOUNTAINS. SEVERE TSTORMS APPEAR UNLIKELY AT THIS
TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH MONDAY NIGHT)
ISSUED AT 300 AM MDT MON AUG 10 2015
MVFR CIGS AND PATCHY FOG IS EXPECTED EARLY THIS MORNING BEFORE
LIFTING BY 15Z OVER MOST TERMINALS. LOW CLOUDS MAY LINGER THROUGH
THE DAY OVER KSNY...KAIA...AND KCDR HOWEVER. ANOTHER ROUND OF
SHOWERS AND TSTORMS ARE EXPECTED MAINLY OVER SOUTHEAST WYOMING
THIS AFTERNOON AND INTO THIS EVENING.
&&
.FIRE WEATHER...
ISSUED AT 222 AM MDT MON AUG 10 2015
NO MAJOR FIRE WEATHER CONCERNS OVER THE NEXT FEW DAYS. NON-CRITICAL
CONDITIONS ARE EXPECTED WITH WIND GUSTS EXPECTED TO REMAIN BELOW 25
MPH AND HUMIDITIES GENERALLY ABOVE 20 PERCENT WITH GOOD TO EXCELLENT
RECOVERY OVERNIGHT. ISOLATED TO WIDELY SCATTERED THUNDERSTORMS COULD
OCCUR EACH AFTERNOON THROUGH THE WEEK. THE MAIN HAZARD FROM THESE
STORMS WILL BE GUSTY AND ERRATIC WINDS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1119 PM MDT TUE AUG 11 2015
.UPDATE...
ISSUED AT 535 PM MDT TUE AUG 11 2015
UPDATED POP GRIDS TO REFLECT LATEST MODEL AND RADAR TRENDS ACROSS
THE CWA. THE TWO MAIN AREAS OF CONCERN THROUGH THE LATE EVENING
HOURS WILL BE THE NORTHERN I-25 CORRIDOR INCLUDING EL PASO AND
PUEBLO COUNTIES AND THE FAR SE CO PLAINS NEAR THE CO/KS BORDER.
THE HRRR HAS BEEN CONSISTENTLY SHOWING A WEAK MCS DEVELOPING
ACROSS EL PASO AND PUEBLO COUNTIES BETWEEN 01-05Z TONIGHT. LAPS
AND MESOSCALE ANALYSIS SHOW 1000-1200 J/KG OF CAPE WITH DEEP
MOISTURE IN PLACE (PWATS 1.2-1.3 WITH DEW POINTS IN THE LOW 60S)
AND WEAK BULK SHEAR OF 20-25 KNOTS. ACROSS THE FAR SE PLAINS THERE
IS THE POTENTIAL FOR A FEW STRONGER STORMS AS CAPE VALUES ARE
CLOSE TO 2000 J/KG. SPC ANALYSIS ALSO DEPICTS UPPER LEVEL
VORTICITY MAXIMA IN PLACE WITH DEEP MOISTURE CONVERGENCE AND SFC
FRONTOGENESIS OCCURRING...WITH THE HRRR ALSO DEVELOPING A FEW
STRONGER STORMS OVER THIS AREA BETWEEN 01ZZ-07Z. STORM ACTIVITY
SHOULD EASE BY 08Z TONIGHT AS SURFACE COOLING LIMITS INSTABILITY
OVERNIGHT. LUKINBEAL
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
SCATTERED THUNDERSTORMS DEVELOPING OVER THE MOUNTAINS THIS
AFTERNOON...AS MOISTURE (PRECIPITABLE WATER OVER 1 INCH) AND
INSTABILITY (CAPES ABOVE 1000 J/KG MOST AREAS) REMAIN PLENTIFUL.
GENERALLY FOLLOWED THE HRRR FOR CONVECTIVE TRENDS FOR LATE AFTERNOON
INTO THE EVENING...WITH A WAVE OF STRONGER CONVECTION OVER THE
MOUNTAINS MOVING INTO THE NORTHERN I-25 CORRIDOR OVER PUEBLO AND EL
PASO COUNTIES IN THE 21Z-01Z TIME FRAME...BRINGING A THREAT OF HEAVY
RAIN TO AREAS AROUND COLORADO SPRINGS/WALDO CANYON. FARTHER
SOUTH...CONVECTION ALONG THE SOUTHERN I-25 CORRIDOR WILL EXPAND
EASTWARD INTO THE EVENING...WITH SOME POCKETS OF HEAVY RAIN ALONG
AND SOUTH OF THE ARKANSAS RIVER. MOUNTAINS AND INTERIOR VALLEYS WILL
SEE A CONTINUATION OF SCATTERED CONVECTION...WITH MODELS AND LATEST
SATELLITE LOOP SUGGESTING LEAST ACTIVITY OVER THE SOUTHWEST
MOUNTAINS AS STRONGER CONVECTION OVER AZ STAY FAIRLY FAR TO THE
WEST.
OVERNIGHT...HRRR DEVELOPS ANOTHER BAND OF HEAVIER PRECIP OVER THE
ARKANSAS VALLEY 04Z-06Z FROM FREMONT COUNTY EAST THROUGH PUEBLO AND
LA JUNTA...WITH FAIRLY VIGOROUS CONVECTION WELL INTO THE NIGHT. NOT
SURE HOW REALISTIC THIS IS GIVEN INITIAL CONVECTION THIS AFTERNOON
POTENTIALLY STABILIZING THE AIR MASS SOMEWHAT...BUT WILL MAINTAIN
POPS PAST MIDNIGHT MANY AREAS AS MOST MODELS KEEP AT LEAST SOME
PRECIP GOING PAST 06Z.
ON WEDNESDAY...EXPECT A DOWNTURN IN CONVECTION AS UPPER RIDGE
CONTINUES TO SLOWLY BUILD NORTHWARD ACROSS THE STATE...WHILE POCKET
OF DRIER AIR OVER WESTERN NM ROTATES NORTHWARD INTO THE REGION.
STILL ENOUGH RESIDUAL MOISTURE FOR ISOLATED TSRA MOST LOCATIONS IN
THE AFTERNOON...THOUGH STORM INTENSITY AND THE THREAT OF HEAVY RAIN
SHOULD BE LESS THAN THE PAST COUPLE DAYS. HIGHEST POPS WILL BE OVER
THE MOUNTAINS...ESPECIALLY NORTHERN HALF OF THE AREA WHERE SLIGHTLY
DEEPER MOISTURE WILL REMAIN. MAX TEMPS MOST LOCATIONS WILL BEGIN TO
MOVE UPWARD AS AIR MASS DRIES AND HEIGHTS BUILD...THOUGH READINGS
WILL STILL BE AT OR SLIGHTLY BELOW MID AUGUST AVERAGES BY LATE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 312 PM MDT TUE AUG 11 2015
WEDNESDAY NIGHT THROUGH FRIDAY...A LARGE RIDGE OF HIGH PRESSURE IS
EXPECTED TO BE CENTERED OVER THE REGION THROUGH FRIDAY...KEEPING
WINDS ALOFT LIGHT. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL
AFTERNOON AND EVE MT SHOWERS AND STORMS...AND STORMS THAT DO
DEVELOP WILL BE SLOW-MOVING AND MOVEMENT WILL BE DIFFICULT TO
ANTICIPATE. LOOK FOR MAX TEMPS TO REMAIN SOMEWHAT STEADY THROUGH
THE PERIOD WITH AFTERNOON HIGHS IN THE 80S FOR THE HIGH
VALLEYS...AND 80S TO MID 90S FOR THE E PLAINS.
SATURDAY THROUGH MONDAY...MODELS INDICATE THAT AN UPPER SHORTWAVE
WILL CROSS MONTANA ON SATURDAY...WHICH WILL HELP TO SOMEWHAT FLATTEN
THE UPPER RIDGE AND EDGE IT TO THE SOUTH. A FRONTAL BOUNDARY WILL
DROP DOWN THE E PLAINS ON SUNDAY...BUT AT THIS TIME THERE DOES NOT
SEEM TO BE MUCH BY WAY OF SIGNIFICANT COOLING OR INCREASED
CONVECTIVE ACTIVITY WITH THIS FEATURE. LOOK FOR A CONTINUATION OF
THE DIURNAL AFTERNOON AND EVE MT STORMS...THOUGH THERE IS A
SLIGHT HINT OF PERHAPS SOME LINGERING SHOWERS DURING THE OVERNIGHT
PERIOD. AS FOR TEMPS...MAX TEMPS WILL REMAIN IN THE 80S TO LOWER
90S FOR THE PLAINS...AND 80S FOR THE HIGH VALLEYS.
TUESDAY...LONG RANGE MODELS SHOW A LOW DROPPING OUT OF CANADA AND
INTO MT AND THE DAKOTAS FOR TUE...SHUNTING THE UPPER RIDGE TO THE
SW. THIS IS STILL A BIT FAR OUT TIME-WISE TO MAKE SIGNIFICANT
CHANGES...BUT IF THIS SOLUTION PERSIST OVER THE NEXT FEW DAYS THEN
THIS MIGHT BRING COOLER TEMPS AND MORE PCPN FOR THE FORECAST AREA.
MOORE
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1117 PM MDT TUE AUG 11 2015
UPPER MONSOON DISTURBANCE WILL TRACK ACROSS FLIGHT AREA TONIGHT
KEEPING ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
FORECAST THROUGH THE OVERNIGHT HOURS. MOSTLY VFR CONDITIONS
EXCEPT IN PRECIPITATION AREAS WHERE MVFR/IFR/LIFR CONDITIONS
CAN BE ENCOUNTERED. ALSO...SOME PATCHES OF MVFR STRATUS WILL BE
POSSIBLE ACROSS THE PLAINS INTO EARLY WEDNESDAY DUE TO RECENT
PRECIPITATION AND LIGHT WINDS.
ON WEDNESDAY...UPPER RIDGE OF HIGH PRESSURE WILL STRENGTHEN OVER
COLORADO...DECREASING THE OVERALL AMOUNT OF MONSOON THUNDERSTORM
ACTIVITY. HOWEVER...THERE WILL STILL BE ENOUGH MOISTURE AROUND FOR
ISOLATED STORMS BEGINNING IN THE MOUNTAINS AFTER 16Z AND ACROSS THE
PLAINS AFTER ABOUT 20Z. AGAIN...LOOKING AT MOSTLY VFR CONDITIONS
ACROSS THE FLIGHT AREA WEDNESDAY. HOWEVER...LOCAL MVFR/IFR/LIFR
CONDITIONS MAY BE ENCOUNTERED IN AREAS OF PRECIPITATION.
FOR THE KCOS...KPUB AND KALS TAF SITES...THE EXPECTATIONS ARE MUCH
THE SAME AS FOR THE REST OF SOUTHERN COLORADO. MOSTLY VFR EXCEPT IN
AREAS OF PRECIPITATION. BOTH KCOS AND KPUB COULD SEE THUNDERSTORMS
TOMORROW BETWEEN ABOUT 21Z AND 04Z. KALS LOOKS LIKE IT MAY REMAIN
DRY AT THIS POINT SO NO STORMS IN THE FORECAST AT THIS TIME.
FINALLY...A FEW AREAS OF MVFR STRATUS COULD SHOW UP ACROSS THE EAST
CENTRAL AND SOUTHEAST COLORADO PLAINS OVERNIGHT INTO EARLY WEDNESDAY
DUE TO RECENT RAINFALL AND LIGHT WINDS. HAVE INTRODUCED AN MVFR
STRATUS DECK IN THE KCOS AND KPUB TAFS AROUND 09Z TO REFLECT THIS
POSSIBILITY.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AL/LW
SHORT TERM...PETERSEN
LONG TERM...MOORE
AVIATION...LW
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
543 AM EDT WED AUG 12 2015
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS THE UPPER LEVELS HAVE
EVOLVED INTO A VERY AMPLIFIED AND SLOW PROGRESSION PATTERN FOR THE
MIDDLE OF AUGUST. LOOKING WEST TO EAST ACROSS THE CONTINENT WE
FIND A DEEP UPPER LOW SPINNING OFF THE NORTHERN CALIFORNIA COAST.
INTERESTING TO NOTE THAT H5 HEIGHTS ASSOCIATED WITH THIS LOW BASED
ON THE LATEST NAEFS OUTPUT ARE APPROACHING -5 STANDARD ANOMALIES
BELOW CLIMATOLOGY. A QUICK AND EASY WAY TO THINK ABOUT STANDARD
ANOMALIES IS TO RELATE THEM TO HOW DIFFERENT THE MODEL FORECAST IS
FROM THE CLIMATOLOGICAL MEAN. THE HIGHER THE NUMBER (POSITIVE OR
NEGATIVE)...THE FURTHER ABOVE OR BELOW THE CLIMO MEAN THE FORECAST
IS. THERE IS A VERY TIGHT UPPER LEVEL HEIGHT GRADIENT JUST INLAND
FROM THE PACIFIC COAST BETWEEN THIS UPPER LOW AND EXPANSIVE
LONGWAVE RIDGING EXTENDING FROM THE SOUTHERN PLAINS NORTHWARD
THROUGH THE INTER-MOUNTAIN WEST INTO SOUTH-CENTRAL CANADA. HOW
TIGHT IS THE HEIGHT GRADIENT...WELL KEEPING WITH THE THEME OF
STANDARD ANOMALIES...THE V (SOUTH TO NORTH) COMPONENT OF THE WINDS
THROUGH A DEEP LAYER OVER THE GREAT BASIN ARE +3-5 ABOVE
CLIMATOLOGY. THE UPPER RIDGED FLOW OF THE NORTHERN STREAM EXTENDS
EASTWARD OVER MUCH OF THE CENTRAL PLAINS AND SOUTH-CENTRAL CANADA
BEFORE TAKING A DEEP DIVE BACK SOUTHWARD INTO THE EASTERN THIRD OF
THE CONUS. THIS DEEP TROUGH NOW EXTENDS ALL THE WAY DOWN INTO
GA/CAROLINAS. AT THE MOMENT...THE FL PENINSULA RESIDES IN A WEAKLY
DEFINED UPPER PATTERN BETWEEN THIS TROUGH TO OUR NORTH...AND UPPER
RIDGING RETREATING WESTWARD ALONG THE NORTHERN GULF COAST.
GUIDANCE ENSEMBLES STILL PREDICT THAT THE FAR SOUTHERN PERIPHERY
OF THE CYCLONIC FLOW AROUND THE BASE OF THIS TROUGH WILL REACH
DOWN INTO NORTHERN/CENTRAL FLORIDA BY THE END OF TODAY.
A WEAK SURFACE FRONT IS MAKING PROGRESS SOUTHWARD ACROSS
AL/GA/CAROLINAS EARLY THIS MORNING...AND IS FORECAST TO STALL NEAR
THE I-10 CORRIDOR LATER TODAY. THE GRADIENT WILL REMAIN WEAK...BUT
OUR POSITION BETWEEN THIS FRONT AND THE SUBTROPICAL RIDGE AXIS
SUPPRESSED TO THE FL STRAITS WILL PROVIDE A GENERAL LIGHT WESTERLY
SYNOPTIC LOW LEVEL FLOW THROUGH MUCH OF THE SHORT TERM PERIOD.
&&
.SHORT TERM (TODAY THROUGH THURSDAY)...
TODAY...
A WEAK FRONTAL BOUNDARY WILL SETTLE SOUTHWARD AND STALL NEAR THE
I-10 CORRIDOR LATER TODAY. OTHER THAN PERHAPS FAR NORTHERN AREAS
AROUND LEVY COUNTY...THE MAJORITY OF THE CONVECTIVE ENHANCEMENT
RELATED TO THIS FRONT AND THE DIGGING UPPER TROUGH ALOFT SHOULD
REMAIN JUST NORTH OF OUR AREA. THEREFORE...OUR FORECAST WILL MORE
RESEMBLE A TYPICAL SUMMER DAY UNDER WESTERLY FLOW. ALREADY SEEING
A FEW SHOWERS DEVELOPING OVER THE COASTAL WATERS WITHIN THE
FAVORED WEAK WESTERLY FLOW. THESE WILL MIGRATE TOWARD THE COAST
DURING THE FIRST FEW DAYLIGHT HOURS...ALTHOUGH THEY WILL BE WIDELY
SCATTERED. MUCH OF THE MORNING FOR MOST SPOTS WILL BE DRY WITH
PARTLY SUNNY SKIES.
AS WE PROGRESS THROUGH THE DAY...WILL SEE A SEA-BREEZE GET
JOINING. WITH THIS BOUNDARY INITIALIZATION...WE WILL SEE A
SCATTERING OF STORMS DEVELOPING ALONG THE I-75 CORRIDOR...HOWEVER
MOST OF THIS ACTIVITY SHOULD FAIRLY QUICKLY PUSH INLAND BY THE
LATER AFTERNOON/EARLY EVENING. AS IS NORMAL UNDER THIS
REGIME...THE BEST COVERAGE OF STORMS AND HIGHEST POPS TODAY WILL
BE OVER THESE INTERIOR ZONES AFTER 19/20Z.
ONE THING TO NOTE. THE THETAE DIFFERENCES BETWEEN THE SURFACE AND
MINIMUM VALUES ALOFT ARE FAIRLY HIGH TODAY. LOOKING AT MOST SPOTS
BETWEEN 20-25K...WHICH IS GETTING INTO THE RANGE FAVORABLE FOR WET
MICROBURSTS GIVEN THE EXPECTED INSTABILITY. THE RAP IS EVEN
FORECASTING VALUES NEAR 30 UP TOWARD CITRUS/LEVY/SUMTER COUNTY.
GIVEN THESE VALUES...THE WET MICROBURST SEVERITY INDEX (WMSI)
CALCULATIONS ARE COMING UP WITH MARGINAL TO FAVORABLE ATMOSPHERIC
CONDITIONS FOR THE FORMATION OF WET MICROBURSTS ASSOCIATED WITH
STRONGER STORMS. WOULD EXPECT MUCH OF THE AREA TO BE WITHIN THE
RANGE OF LOCALLY 40-50 MPH GUSTS...BUT CAN NOT RULE OUT A FEW
ISOLATED SEVERE TYPE GUSTS...ESPECIALLY NORTH OF THE I-4 CORRIDOR.
JUST SOMETHING TO KEEP AND EYE ONE. KEEP IN MIND...THE WMSI IS A
CONDITIONAL INDEX...MEANING YOU NEED CONVECTION PRESENT FOR IT TO
MEAN ANYTHING. SO EVEN THOUGH THE VALUES MAY BE HIGH...THOSE AREA
BEHIND THE SEA-BREEZE WILL HAVE A LOW CHANCE OF CONVECTION AND
HENCE STRONG GUSTS.
TONIGHT...
THE EVENING STORMS RELATED TO THE DIURNAL HEATING OF TODAY WILL
DISSIPATE OVER BY THE I-95 CORRIDOR BY THE LATER EVENING
HOURS...AND THEN FOCUS WILL SHIFT TO THE LIKELIHOOD OF DEVELOPING
SHOWERS/STORMS OVER THE NORTHEAST GULF AND MOVING ASHORE. SOME OF
THE HIRES GUIDANCE MEMBERS ARE RATHER ROBUST WITH THIS CONVECTIVE
ACTIVITY...AND TAKING AN NEIGHBORHOOD ENSEMBLE APPROACH DOES GIVE
HIGH END CHANCE TO LIKELY RAIN CHANCES BY DAWN NEAR THE COAST FROM
TAMPA BAY NORTHWARD.
THURSDAY LOOK TO HAVE THE POTENTIAL TO BE THE WET DAY OF THE
WEEK...AT LEAST IN TERMS OF TOTAL RAINFALL COVERAGE. THE WEAK
BOUNDARY WILL BE IN PLACE...THE UPPER TROUGH WILL BE IN
PLACE...AND THE BEST POSITION OF THE COUPLED UPPER JET STRUCTURE
WILL BE IN PLACE. THEREFORE...THE CHANCES FOR ORGANIZED BANDS OF
CONVECTION MOVING SHORE ARE PRETTY HIGH. WOULD THINK THE BEST
CHANCES FOR LONGER PERIODS OF RAINFALL WOULD BE NORTH OF THE
SARASOTA AREA IN CLOSER PROXIMITY TO THE FRONTAL FOCUS...BUT WOULD
ANTICIPATE/PLAN FOR SCT SHOWERS ALL THE WAY DOWN TO THE FORT MYERS
AREA. LATER IN THE DAY WITH SOME DIURNAL HEATING...THE MAIN FOCUS
FOR STORMS MAY ONCE AGAIN BEGIN TO SHIFT INLAND AWAY FROM THE
COAST...HOWEVER THE PROCESS IS LIKELY TO NOT BE AS DEFINED AS IT
WILL BE TODAY.
&&
.LONG TERM...
.LONG TERM /FRIDAY-TUESDAY/...
THE SHIFTING MID-LEVEL TROUGH AXIS OVER THE EASTERN SEA BOARD HELPS
PUSH A SURFACE FRONTAL BOUNDARY INTO CENTRAL FLORIDA BY LATE
THURSDAY NIGHT/EARLY FRIDAY MORNING. THE EVOLUTION OF A CUTOFF MID-
LEVEL LOW LATE FRIDAY INTO SATURDAY IS A TAD DIFFERENT IN THE 00Z
GFS COMPARED TO THE 00Z ECMWF.
THE GFS FAVORS A LESS PRONOUNCED CUTOFF LOW OVER THE NORTHWESTERN
GULF/LOWER MISSISSIPPI RIVER VALLEY WHILE THE ECMWF CARRIES MORE OF
AN ELONGATED MID-LEVEL TROUGH STRETCHING INTO THE TENNESSEE VALLEY.
THE ECMWF SOLUTION KEEPS THE FRONTAL BOUNDARY STALLED OVER THE
PENINSULA OF FLORIDA WHILE THE GFS SOLUTION ALLOWS THE BOUNDARY TO
WEAKEN AND THE MOISTURE TO RETREAT NORTH INTO SOUTH GEORGIA/NORTH
FLORIDA BY SUNDAY. THE 00Z CANADIAN IS MORE CLOSELY ALIGNED WITH
THE ECMWF...TENDED TO PREFER A WETTER FORECAST.
EITHER WAY...ELEVATED RAIN CHANCES EXPECTED THROUGH THE WEEKEND. THE
GFS SOLUTION WOULD LEND TO A MORE TYPICAL AFTERNOON/EVENING DIURNAL
THUNDERSTORM PATTERN COMPARED TO THE MORE CONSTANT FRONTAL ZONE
CONVECTION THAT COULD PRESENT A FLOOD/HEAVY RAIN RISK IN THE
ECMWF/CANADIAN SOLUTION. BY THE END OF THE PERIOD...THE BUILDING
SURFACE RIDGE AXIS SHOULD HELP PUSH THE REMNANT FRONTAL BOUNDARY
NORTHWARD. ALOFT...THE CUTOFF LOW/ELONGATED TROUGH SHOULD BE
ABSORBED INTO THE NEXT LARGE SCALE TROUGH WHICH WILL PUSH THROUGH
THE EASTERN UNITED STATES BY MID NEXT WEEK. TEMPERATURES SHOULD
REMAIN IN THE UPPER 80S TO LOWER 90S FOR HIGHS AND 70S DURING THE
OVERNIGHTS.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE WEST-CENTRAL AND SOUTHWEST
FLORIDA UNDERNEATH SOME PASSING SCT HIGH LEVEL CIRRUS. OVERALL VFR
CONDITIONS CAN BE EXPECTED THROUGH THE TAF PERIOD WITH THE
EXCEPTION OF A POSSIBLE BRIEF VIS OR CIG RESTRICTION ASSOCIATED
WITH A PASSING SHOWER. THE BEST CHANCE FOR A QUICK SHOWER OR STORM
WILL BE IN THE EARLY TO MID AFTERNOON...WITH THE MAJORITY OF THE
STORM ACTIVITY THEN MIGRATING INLAND FROM THE TERMINALS FOR THE
LATER AFTERNOON...AND ESPECIALLY THE EVENING HOURS.
&&
.MARINE...
A WEAK FRONTAL BOUNDARY WILL APPROACH THE AREA TODAY AND STALL
OVER THE NORTHEAST GULF OF MEXICO TONIGHT AND THURSDAY. THIS
BOUNDARY WILL THEN DECAY FRIDAY INTO SATURDAY. WINDS WILL BE
GENERALLY WESTERLY THROUGH THURSDAY NIGHT AND THEN BECOME MORE
VARIABLE IN NATURE. WINDS AND SEAS WILL GENERALLY REMAIN BELOW
HEADLINE CRITERIA...OUTSIDE OF SHOWERS AND STORMS. STORMS MAY
BECOME NUMEROUS IN NATURE FOR A TIME LATE TONIGHT INTO THURSDAY
ALONG AND AHEAD OF THE STALLED FRONTAL BOUNDARY.
&&
.FIRE WEATHER...
NO SIGNIFICANT FIRE WEATHER CONCERNS ARE ANTICIPATED THROUGH THE
REMAINDER OF THE WORK WEEK. A WEAK FRONT WILL SETTLE SOUTHWARD AND
STALL OVER NORTH FLORIDA LATER TODAY. THIS FRONT WILL THEN
DISSIPATE BY THE EARLY PORTION OF THE UPCOMING WEEKEND. WESTERLY
FLOW OFF THE GULF OF MEXICO WILL KEEP ABUNDANT LOW LEVEL MOISTURE
IN PLACE TO PREVENT CRITICAL LEVELS OF RELATIVE HUMIDITY FROM
BEING REACHED. SHOWERS AND STORMS ARE FORECAST TO BECOME QUITE
NUMEROUS IN NATURE ON THURSDAY...ESPECIALLY ALONG AND NORTH OF
THE I-4 CORRIDOR...WHERE A WETTING RAIN SHOULD BE EXPECTED AND
PLANNED FOR.
FOG POTENTIAL...NO SIGNIFICANT AREAS OF FOG OR VISIBILITY
RESTRICTIONS ARE ANTICIPATED THROUGH THE FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 79 88 77 / 20 50 70 50
FMY 91 77 90 76 / 20 30 60 40
GIF 92 76 90 75 / 50 30 80 50
SRQ 89 78 88 76 / 20 50 70 60
BKV 90 74 89 73 / 30 60 70 50
SPG 89 79 88 78 / 20 50 70 60
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...GARCIA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
343 AM EDT WED AUG 12 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED IN THE MIDWEST TODAY WILL EXTEND EASTWARD
AND INTO THE DELMARVA REGION THURSDAY. A FRONTAL SYSTEM WILL BE
NEAR THE SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN
MAINLY EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE FRONT WILL BE STALLED NEAR THE EAST PART OF THE FORECAST AREA
TODAY. HEATING AND CONVERGENCE ASSOCIATED WITH THIS FEATURE MAY
SUPPORT THUNDERSTORMS BUT THE CHANCE APPEARS LOW. THE MODELS
INDICATE JUST WEAK CONVERGENCE. THE WATER VAPOR IMAGERY SHOWS DRY
AIR HAS OVERSPREAD THE AREA. THE GFS AND NAM FORECAST SOUNDINGS
INDICATE MID-LEVEL CAPPING. THE HRRR AND SPC WRF DISPLAYED
JUST ISOLATED SHOWERS OR THUNDERSTORMS. ANY THUNDERSTORMS SHOULD
DISSIPATE THIS EVENING WITH THE LOSS OF HEATING. THE TEMPERATURE
GUIDANCE WAS CLOSE TODAY AND TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
HIGH PRESSURE RIDGING EASTWARD TOWARD THE DELMARVA REGION WILL
CONTINUE TO DIRECT DRY AIR INTO THE FORECAST AREA. WE KEPT THE
FORECAST DRY. THE TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE MEDIUM-RANGE GUIDANCE CONTINUES TO SHOW AN UPPER TROUGH
ACROSS THE EASTERN PART OF THE NATION. THE REMNANTS OF THE
FRONTAL SYSTEM WILL LINGER NEAR THE FORECAST AREA PLUS A MOISTURE
INCREASE SHOULD OCCUR WITH TIME ASSOCIATED WITH AN ONSHORE FLOW.
THE GFS AND ECMWF MOS HAVE POPS 10 TO 20 PERCENT EARLY INCREASING
TO 30 TO 50 PERCENT LATE IN THE PERIOD. THE MOS HAS TEMPERATURES
NEAR CLIMATOLOGY.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE THROUGH THE AREA THIS MORNING. ISOLATED
CONVECTION IS OCCURRING NEAR THE FRONT EARLY THIS MORNING. WILL
MENTION SHRA IN TEMPO GROUPS WHERE NECESSARY. SOME MVFR CIGS
POSSIBLE EARLY THIS MORNING. WINDS SHIFTING TO THE NORTHEAST
BEHIND THE FRONT. MODELS SHOW POTENTIAL FOR MVFR FOG EARLY THIS
MORNING...ALTHOUGH WINDS MAY STAY UP ENOUGH TO PRECLUDE
DEVELOPMENT. HAVE INDICATED MVFR FOG AT AGS/OGB 08Z-12Z.A DRIER
AIR MASS WILL BUILD INTO THE REGION LATER TODAY WITH NO
RESTRICTIONS EXPECTED.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO
AVIATION ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
99
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1216 AM CDT WED AUG 12 2015
...Updated Synopsis and aviation discussion...
.SYNOPSIS...
ISSUED AT 1213 AM CDT WED AUG 12 2015
At 00z Wednesday a 700mb and 500mb high was located near southwest
Oklahoma. An upper level ridge axis extended north northwest of
the upper low to eastern Montana. An upper level trough was
located over south central Colorado. A 850mb and 700mb moisture
axis appears to be located from the panhandle of Texas to
northeast Colorado. This was also located near a +9 to +12c 700mb
temperature gradient. At 00z Wednesday a surface highs was located
over southeast Nebraska and a trough of low pressure was located
along the lee of the Rockies. An axis of upper 60s to near 70
degree surface dew points were located from the panhandle of Texas
to west central Kansas.
&&
.SHORT TERM...(THIS EVENING THROUGH Wednesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The near term will bring chances for heavy rain producing
thunderstorms. The first opportunity will be later tonight as the 4
km NAM, HRRR and NMM models all redevelop convection later in the
day over eastern colorado that moves in to about the western two or
perhaps 3 tiers of KS counties. the key here to support convection
is the very high precipitable water values, and hence conditional
instability present. still no severe weather threat, with mainly
efficient warm rain processes and frequent lightning. easterly
surface wind, and an increasing surface pressure gradient is
expected wednesday with a transient 500 mb shortwave, in the western
counties, in proximity to the high precipitable water axis on the
west edge of the surface high. models again generate precipitation
into wednesday in this zone. extensive cloud cover may again muddle
the high temperature forecast, as occurred today and temperatures
should be at or below normal.
.LONG TERM...(Wednesday NIGHT THROUGH Tuesday)
ISSUED AT 401 PM CDT TUE AUG 11 2015
The upper ridge over the central and southern rockies will continue
to amplify, resulting in vorticity disturbances shifted farther
north across the northern plains. however, the GFS and ECMWF show a
vigorous wave during the weekend moving through the northern
states, effectively flattening the upper ridge and returning zonal
flow aloft to the central high plains. this setup will result in
low pressure across western kansas just ahead of an approaching
baroclinic zone/frontal boundary by early to mid week, and a
return to convective chances. the more zonal pattern may stay in
place for at least several days.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Wednesday NIGHT)
ISSUED AT 1213 AM CDT WED AUG 12 2015
A southeasterly wind will continue overnight at less than 10
knots as a surface trough of low pressure remains nearly
stationary along the lee of the Rockies.The southeasterly winds
will increase by late morning into the 10 to 15 knot range.
Scattered thunderstorms will be possible overnight into early
Wednesday morning given the increasing moisture and lift in the
800mb to 600mb level. Areas more favorable for this convection
will be DDC and GCK. Ceilings are expected to primarily be above
3500 AGL based on 00z NAM BUFR soundings, however ceilings may
fall into the MVFR category at times with the thunderstorms early
this morning.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 90 67 93 / 10 0 10 10
GCK 65 91 67 92 / 10 0 10 0
EHA 66 92 67 92 / 10 10 10 0
LBL 68 92 68 93 / 10 0 10 0
HYS 65 91 68 92 / 10 10 20 10
P28 67 89 69 91 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GAYLORD MI
307 AM EDT WED AUG 12 2015
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL...A CHANCE OF THUNDERSTORMS TONIGHT.
HIGH PRESSURE EXTENDS FROM EASTERN KS TO NW WI. JUST IN ADVANCE OF
THE HIGH...PATCHY STRATOCU REMAINS FRUSTRATINGLY STUBBORN OVER A
PORTION OF NORTHERN MI...THOUGH THE LOW CLOUDS ARE SLOWLY ERODING
WITH TIME. THE HIGH WILL DRIFT SE TOWARD THE OHIO VALLEY THRU
TONIGHT. SHOWERS ARE OCCURRING IN THE WARM/MOIST ADVECTION ZONE ON
THE NORTH FLANK OF THE HIGH...JUST NORTH OF MN. WE WILL ENTER THAT
REGION VERY LATE TODAY INTO TONIGHT...WITH A WARM FRONT ADVANCING
INTO NORTHERN MI LATE TONIGHT. MOST OF TODAY WILL BE QUIET...BUT
CHANCES FOR PRECIP WILL BE INCREASING AS WE MOVE INTO TONIGHT.
TODAY...ONGOING CLOUD COVER WILL ERODE THIS MORNING...THANKS TO
HEATING/MIXING...AND THE ARRIVAL OF A NARROW AXIS OF SOMEWHAT DRIER
AIR NOW OVER WI AND CENTRAL UPPER MI. THAT WILL BE FOLLOWED BY
THE ARRIVAL OF SOME BUBBLY ALTOCU...THE WARM-ADVECTION CLOUD COVER
NOW NORTH OF MN. THE NAM IS CONSIDERABLY FURTHER EAST WITH THE
WARM FRONT LATE TODAY...REACHING A CMX-GRB LINE. THIS RESULTS IN
THE NAM ALLOWING CONVECTION TO REACH NW LOWER MI LATE IN THE
AFTERNOON. GIVEN THE NNW FLOW ALOFT...UPSTREAM RADAR/CLOUD
TRENDS...AND THE BULK OF THE OTHER SHORT-TERM GUIDANCE...THIS
LOOKS TOO FAST. SOMETHING CLOSER TO THE RAP IS PREFERRED...KEEPING
THE WARM FRONT IN CENTRAL WI AND -SHRA IN EASTERN WI/WESTERN UPPER
MI. SOME ACCAS WILL EXPAND IN NW LOWER MI LATE IN THE DAY...BUT
WILL KEEP THE FORECAST DRY THRU 8 PM.
HIGHS WILL BE IN THE 70S.
TONIGHT...WARM FRONT WILL MOVE EAST TOWARD A MUNISING-HTL LINE BY
DAWN. AN AREA OF SHRA EAST OF THE FRONT...STARTING THE EVENING OVER
NE WI/NORTHERN LAKE MI/CENTRAL UPPER WILL MOVE SE...ASSOCIATED WITH
A WEAK BUT FAST-MOVING SHORTWAVE DIVING ACROSS MI. THIS WILL POSE A
RISK FOR PRECIP ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA...
MAINLY DURING THE EVENING (WILL MAINTAIN A RISK OF PRECIP OVERNIGHT
SOUTH OF M-72). NAM LOVES IT/S LOW LEVEL MOISTURE AND GOES
BONKERS WITH MUCAPE. BUT EVEN A MORE REALISTIC MOISTURE PORTRAYAL
GIVES US HIGH THREE-FIGURES OF CAPE...SO WILL ADD THUNDER. WILL
STILL JUST KEEP POPS IN THE CHANCE CATEGORY. A BIT OF SHORTWAVE
RIDGING ARRIVES OVERNIGHT FROM THE NW...PROVIDING A LULL. ANOTHER
BATCH OF PRECIP MAY TRY TO GET GOING BACK BEHIND THAT RIDGE OVER
WESTERN LAKE SUPERIOR AND ENVIRONS. ANY SUCH ACTIVITY LOOKS
UNLIKELY TO REACH THIS FORECAST AREA BY MORNING.
MIN TEMPS WILL BE MILD...ESPECIALLY IN NW LOWER...WHERE A WARMER/
STICKIER AIRMASS WORKS IN BEHIND THE WARM FRONT. LOWS WILL BE
IN THE MID 50S TO MID 60S.
&&
.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL: STILL MONITORING THUNDERSTORM AND
LOCALLY HEAVY RAIN POTENTIAL TO END THE WORK WEEK.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: ONE RATHER MERIDIONAL FLOW
REGIME ACROSS THE CONUS...CONSISTING OF WESTERN/HIGH PLAINS RIDGE
AND EASTERN TROUGH...EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THIS WORK WEEK. NORTHERN MICHIGAN WILL REMAIN SQUARELY UNDER THE
INFLUENCE OF THE LATTER...WITH REINFORCING WAVES AND THEIR ATTENDANT
FRONTAL FEATURES BRINGING SOME SHOWER AND THUNDERSTORM THREAT
THURSDAY INTO FRIDAY. EXCELLENT INTER/INTRA MODEL AGREEMENT FOR A
RATHER SUBSTANTIAL PATTERN SHIFT HEADING INTO THE WEEKEND AND THE
START OF NEXT WEEK...WITH NORTHERN EXTENT OF UPSTREAM RIDGING
FOLDING OVER AND ACROSS THE NORTHERN LAKES...EVENTUALLY SETTING UP A
MUCH MORE ZONAL FLAVOR TO THE FLOW PATTERN ACROSS THE NORTHERN CONUS.
PRIMARY FORECAST CONCERNS/CHALLENGES: EVOLUTION OF SHOWER AND
THUNDERSTORM CHANCES THURSDAY THROUGH FRIDAY.
DETAILS: A CHALLENGING FORECAST SETTING UP FOR THURSDAY AS SOUTHWARD
RETREAT OF WHAT WAS ONCE OVERHEAD SURFACE HIGH PRESSURE
CONTINUES...ALLOWING A WEAK WARM FRONT TO SWEEP ACROSS THE AREA.
FRONT ITSELF DOES NOT LOOK ALL THAT ACTIVE...WITH LITTLE DEEP LAYER
SUPPORT. INCREASINGLY WARM/HUMID AIRMASS AND PASSING OF SUBTLE MID
LEVEL WAVE MAY ALLOW A FEW AFTERNOON SHOWERS AND STORMS TO
FIRE...ALTHOUGH STILL BELIEVE BETTER ACTIVITY WILL WAIT UNTIL THE
OVERNIGHT HOURS WHEN SOUTHEAST DROPPING CANADIAN COLD FRONT BEGINS
TO ENTER THE PICTURE. WHILE OVERNIGHT TIMING SHOULD HELP TO PREVENT
MUCH OF A SEVERE WEATHER THREAT...0-6KM BULK SHEAR OF UP TO 30 KNOTS
DOES SUPPORT AT LEAST SOME STORM ORGANIZATION.
COLD FRONT EXPECTED TO ONLY MAKE SLOW PROGRESS SOUTH ACROSS THE AREA
FRIDAY AS PARENT LOW PRESSURE IS WELL REMOVED TO THE NORTH. PER THE
USUAL...DAYTIME HEATING WILL ONLY FURTHER HINDER THE FRONTAL
ADVANCEMENT...ALTHOUGH SUSPECT SPEED TO BE AT LEAST PARTIALLY
DICTATED BY ANY SHOWER AND STORM PRODUCED OUTFLOWS. STILL LIKE THE
IDEA OF KEEPING THE BETTER CHANCES FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS SOUTH OF THE BRIDGE...PARTICULARLY SOUTH OF M-32. WHILE
NOT EXTREME...PRECIPITABLE WATERS AROUND AN INCH AND A HALF AND
POSSIBILITY FOR AT LEAST A COUPLE ROUNDS OF STORMS DEFINITELY
SUPPORTS SOME LOCALLY HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL IN OUR LATEST HAZARDOUS WEATHER PRODUCTS.
&&
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 306 AM EDT WED AUG 12 2015
AS MENTIONED EARLIER...SOME RATHER SIGNIFICANT CHANGES TO THE
LONG WAVE PATTERN SET TO TAKE SHAPE TO START THE WEEKEND. STRONG
ENERGY PUNCHING INTO THE CANADA WEST COAST AND EASTWARD PUNT OF
CURRENT WEST COAST CUTOFF LOW HELP SET THESE CHANGES IN
MOTION...WORKING IN TANDEM TO FORCE NORTHERN EXTENT OF SUBTROPICAL
RIDGE TO FOLD OVER INTO THE NORTHERN LAKES. PATTERN SET TO BECOME
TEMPORARILY MORE ZONAL INTO THE START OF NEXT WEEK AS NORTHERN
EXTENT OF RIDGING IS SHUNTED OFF THE EAST COAST. THE WEEKEND
CONTINUES TO LOOK DRY AND RATHER WARM...WITH TEMPERATURES AT LEAST
SEVERAL DEGREES ABOVE NORMAL. NOT OUT OF THE REALM OF POSSIBILITY
A FEW OF THE TRADITIONAL WARMER LOCALES MAKE A RUN AT 90 DEGREES
BY SUNDAY. NEXT STRETCH OF ACTIVE WEATHER (AT LEAST POTENTIALLY)
ARRIVES SUNDAY NIGHT THROUGH TUESDAY AS WARM/MOIST AIRMASS IS
WORKED OVER BY APPROACHING WAVES AND HINTS OF A SLOW MOVING COLD
FRONT. OF COURSE...PLENTY OF TIME FOR THIS TO ALL CHANGE...SO
INHERITED CHANCY POPS MORE THAN FINE FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 131 AM EDT WED AUG 12 2015
SOME MVFR CIGS OVERNIGHT...OTHERWISE VFR.
LOW CIGS CONTINUE OVER PARTS OF NORTHERN LOWER MI...THOUGH THESE
ARE SLOWLY ERODING. MVFR CIGS ARE POSSIBLE AT ALL SITES BUT MBL
OVERNIGHT. THE SUN COMING UP WILL FINISH OFF THESE CLOUDS ONCE AND
FOR ALL SHORTLY THEREAFTER.
A WARM FRONT WILL ADVANCE EAST INTO WI TODAY. -SHRA AHEAD OF THIS
FRONT WILL EXPAND INTO NW LOWER MI WEDNESDAY EVENING...POTENTIALLY
IMPACTING TVC/MBL. GENERALLY EXPECT CIGS/VSBYS TO REMAIN VFR.
A BIT OF A NW BREEZE ON WEDNESDAY...NOT AS GUSTY AS TUESDAY.
&&
.MARINE...
ISSUED AT 306 AM EDT WED AUG 12 2015
NW WINDS WILL CONTINUE TODAY...THOUGH WEAKER/LESS GUSTY THAN
TUESDAY. A WARM FRONT WILL MOVE EAST INTO NORTHERN MI
TONIGHT...PERHAPS BRINGING SHOWERS/STORMS TO NORTHERN LAKE MI.
SOUTHWEST WINDS WILL SEEN ON THURSDAY BEHIND THE WARM
FRONT...THOUGH AGAIN THESE WILL NOT BE PARTICULARLY STRONG. SMALL
CRAFT ADVISORIES ARE NOT EXPECTED TO BE NEEDED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
NEAR TERM...JAZ
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JAZ
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS DULUTH MN
340 AM CDT WED AUG 12 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
SUMMER HEAT RETURNS WITH SOME OF THE WARMEST WEATHER OF THE SUMMER
SO FAR TODAY AND TOMORROW. MORNING SHOWERS AND MAYBE A THUNDERSTORM
ACROSS THE TIP OF THE MINNESOTA ARROWHEAD THIS MORNING...BUT
OTHERWISE MOSTLY SUNNY THIS AFTERNOON WITH A BREEZY SOUTHWEST WIND.
TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST
ACROSS THE AREA WITH THE POSSIBILITY FOR A FEW STORMS TO BECOME
STRONG TO SEVERE. THURSDAY WILL BE THE HOTTEST DAY OF THE FORECAST
WITH HIGHS IN THE UPPER 80S TO LOW 90S AND THE POSSIBILITY FOR
ISOLATED STORMS.
ON THE SYNOPTIC SCALE A FAIRLY TYPICAL SUMMER PATTERN WITH AN UPPER
LEVEL RIDGE AXIS ALONG THE HIGH PLAINS AND A RESULTING NORTHWEST
FLOW ALOFT LOCALLY. THIS MORNING AN ELEVATED WARM FRONT IS MOVING
ACROSS FAR NORTHEAST MINNESOTA AND IT MOVES SOUTHEAST ACROSS SW
ONTARIO AND ACROSS WESTERN LAKE SUPERIOR...RESULTING IN SOME
ISOLATED SHOWERS AND STORMS. THE BROAD AREA OF HIGH PRESSURE OVER
THE AREA YESTERDAY HAS MOVED SOUTH INTO THE MID-MISSISSIPPI TO OHIO
VALLEY...WHICH WILL RESULT IN SOUTHWEST FLOW AT LOW LEVELS AND
CAUSE 850MB TEMPS TO SURGE 4-8 DEG CELSIUS TODAY. THIS WILL ALSO
INCREASE LOW LEVEL MOISTURE RESULTING IN DEW POINTS HEADING INTO THE
LOW TO MID 60S BY TONIGHT. THIS WILL ALL BE AHEAD OF A WEAK
FRONT/TROUGH THAT IS EXPECT TO BE THE FOCUS FOR STORM INITIATION
ACROSS SOUTHERN MANITOBA AND FAR NORTHEAST NORTH DAKOTA LATE TODAY
WITH STORMS MOVING INTO NORTHERN MINNESOTA TONIGHT. WHILE ONLY A
SUBTLY MID-LEVEL SHORTWAVE EXISTS AT 500MB...A 80-100 KT 300MB JET
STREAK ALOFT WILL PROVIDE RESULT IN DIVERGENCE ALOFT ACROSS
NORTHEAST MINNESOTA TONIGHT AND THUS PROVIDE SOME LARGE-SCALE
LIFT...NOT TO MENTION THE FASTER WINDS ALOFT WILL RESULT IN BETTER
DEEP LAYER SHEAR FOR STORMS TO SUSTAIN INTO THE NIGHT. ON THURSDAY
ANOTHER ELEVATED TROUGH/FRONT WILL MOVE THROUGH FROM THE
NORTHWEST...BUT CAP WILL LIKELY LIMIT COVERAGE OF STORMS.
EARLY THIS MORNING...PATCHY FOG WITH SHOWERS ACROSS THE TIP OF THE
ARROWHEAD. RAP SEEMED TO HAVE A GOOD HANDLE ON THE FOG DEVELOPMENT
WITH THE LOWEST VISIBILITIES DEVELOPING ACROSS NORTHEAST
WISCONSIN...WITH FOG EXPECTED TO BURN OFF JUST AFTER SUNRISE. USED
JUST SHOWERS WORDING IN THE FORECAST FOR THE ARROWHEAD GIVEN LACK OF
INSTABILITY EARLY THIS MORNING...BUT ADD IN ISOLATED THUNDER TOWARDS
MID-MORNING. OTHERWISE CLEAR SKIES AND TEMPS FALLING TO THE MID 50S
OR COOLER IN A FEW SPOTS.
THIS AFTERNOON...HOT AND SUNNY. BREEZY...SOUTHWEST WINDS GUSTING TO
20-25 MPH AT TIMES DUE TO DEEP MIXING. HIGHS IN THE LOW 80S OVER
NORTHWEST WISCONSIN AND THE ARROWHEAD...INTO THE MID TO UPPER 80S
ELSEWHERE INCLUDING THE TWIN PORTS. INCREASING CLOUDS ALONG THE
INTERNATIONAL BORDER LATE IN THE DAY.
TONIGHT...ISOLATED TO SCATTERED SHOWERS AND STORMS MOVING FROM
NORTHWEST TO SOUTHEAST ACROSS NORTHEAST MINNESOTA INTO NORTHWEST
WISCONSIN. WITH MUCAPE VALUES 1500-2000 J/KG AND DEEP LAYER SHEAR
AROUND 40-50KTS STRONG TO SEVERE STORMS ARE LIKELY IF STORMS DO
DEVELOP. THESE STORMS ARE EXPECTED TO BE ELEVATED....BUT IT SHOULD
BE NOTED 0-3KM HELICITY OF 300-400 M2/S2 ACROSS NORTH-CENTRAL
MINNESOTA AROUND 00-04 UTC THIS EVENING WHICH WOULD RESULT IN
ROTATING STORMS...BUT THE HIGH LCL HEIGHTS SHOULD PRECLUDE A
TORNADIC RISK. STILL...SOMETHING TO MONITOR. OTHERWISE THE NORMAL
HAIL/WIND/HEAVY RAINFALL THREATS WITH STORMS EXPECTED TO MOVE ACROSS
NORTHEAST MINNESOTA THROUGH MIDNIGHT AND ROLL INTO NORTHWEST
WISCONSIN IN THE EARLY MORNING HOURS. AGREE WITH INITIAL DAY ONE SPC
OUTLOOK WITH A MARGINAL RISK FOR MUCH OF THE NORTHLAND...BUT THIS
MAY NEED TO BE REEVALUATED FOR AN UPGRADE THIS AFTERNOON DEPENDING ON
HOW CONDITIONS EVOLVE.
THURSDAY...SOME UNCERTAINTY AS TO PRECIPITATION BUT NOT WHEN IT
COMES TO THE HEAT AND HUMIDITY...IT IS GOING TO BE A HOT ONE OUT
THERE. MOST GUIDANCE DEPICTING ANOTHER TROUGH/FRONT MOVING THROUGH
IN THE AFTERNOON...BUT BASED ON MODEL SOUNDINGS THINK CAP MIGHT BE
STRONG ENOUGH TO PREVENT WIDESPREAD STORMS. IF STORMS DO
DEVELOP...EXPECT RAPID DEVELOPMENT DUE TO MUCAPE IN EXCESS OF 2000
J/KG AND WITH 0-6KM SHEAR IN THE 25 TO 35 KT RANGE COULD SEE STORMS
SUSTAIN FOR A FEW HOURS. HIGHS IN THE MID 80S ACROSS NORTHWEST
WISCONSIN...IN THE UPPER 80S TO LOW 90S ACROSS NORTHEAST MINNESOTA
EXCEPT FOR THE TIP OF THE ARROWHEAD.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
A COLD FRONT WILL CONTINUE SOUTH THROUGH THE NORTHLAND THURSDAY
NIGHT WITH HIGH PRESSURE BUILDING IN DURING THE DAY FRIDAY. WE
LINGER CHANCES FOR SHOWERS/STORMS THURSDAY NIGHT OVER THE EASTERN
TWO THIRDS OF THE CWA THEN WENT DRY FOR MOST AREAS ON FRIDAY UNDER
THE HIGH. HIGHS FRIDAY WILL BE IN THE MIDDLE 80S.
THE HIGH WILL MOVE OFF TO THE EAST SATURDAY WITH ANOTHER COLD FRONT
OVER THE NORTHERN PLAINS PROGRESSING EAST. IT SHOULD BE VERY WARM
AND DRY SATURDAY WITH HIGHS IN THE 80S.
THE FRONT WILL CONTINUE EAST SATURDAY NIGHT INTO SUNDAY. THERE ARE
SOME TIMING DIFFERENCES BETWEEN THE GFS/ECMWF...WITH THE GFS FASTER.
THERE WILL BE A CHANCE FOR SHOWERS/STORMS SATURDAY NIGHT/SUNDAY WITH
THIS FRONT. AT THIS POINT...THE INSTABILITY IS NOT REAL IMPRESSIVE.
HOWEVER...THERE WILL BE A GOOD SOUTH/SOUTHWEST FLOW AHEAD OF THE
FRONT AS SEEN WITH 850MB WINDS 40-50KT AND GOOD LOW LEVEL
CONVERGENCE WITH THE FRONT. SOME STRONG STORMS WILL BE POSSIBLE.
THE MODELS DIVERGE MONDAY INTO MID WEEK WITH SOME FAIRLY LARGE
DIFFERENCES. AT THIS POINT WE HAVE LOW POPS THROUGH THAT PERIOD.
HIGHS MONDAY/TUESDAY WILL BE COOLER WITH HIGHS IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1238 AM CDT WED AUG 12 2015
GENERALLY VFR CONDITIONS SHOULD PREVAIL OVER THE NEXT 24 HOURS.
HOWEVER... DID INTRODUCE SOME TEMPO GROUPS FOR OVERNIGHT FOG AS
HIB/AIT HAVE ALREADY SEEN VIS DECREASE TO 2SM. NAM BUFR SOUNDINGS
SUGGEST LOW LEVELS BECOMING CLOSE TO SATURATED MAINLY AFTER 10Z
FOR DLH/HYR AS WELL. FOR THE REMAINING SITES... OCCASIONAL PATCHY
FOG WILL BE POSSIBLE... BUT SIGNAL FROM THE GUIDANCE WAS NOT AS
STRONG SO DECIDED AGAINST INCLUDING IN THE TAFS. WINDS WILL BECOME
GUSTY WEDNESDAY AFTERNOON OUT OF THE SOUTHEAST. THERE WILL BE A
CHANCE OF SHOWERS MAINLY AFTER 00Z THURSDAY. THUNDERSTORMS WILL
BE POSSIBLE... BUT WITH SPOTTY COVERAGE OF STORMS EXPECTED... LEFT
VCTS OUT OF THE TAFS FOR NOW. THIS MAY NEED TO BE ADJUSTED AS
CONFIDENCE INCREASES WITH THE NEXT FORECAST PACKAGE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 85 65 90 65 / 10 30 20 30
INL 88 61 88 59 / 40 50 20 10
BRD 86 66 90 65 / 10 20 10 10
HYR 82 63 86 63 / 0 40 30 20
ASX 84 64 88 62 / 10 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...MELDE
AVIATION...MCLOVIN
AREA FORECAST DISCUSSION
NWS RALEIGH NC
306 AM EDT WED AUG 12 2015
.SYNOPSIS...A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA DURING
THE EARLY MORNING HOURS...WEAKENING AS IT MOVES TOWARD THE COAST AND
SOUTH CAROLINA DURING THE DAY. HIGH PRESSURE SLOWLY BUILDS INTO THE
REGION FROM THE NORTHEAST THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 AM WEDNESDAY...
THE LATEST SURFACE ANALYSIS SHOWS THE SURFACE COLD FRONT MOVING OVER
THE NORTHWEST PIEDMONT...WITH THE DEW POINT AT KINT AND KTDF HAVING
DROPPED INTO THE MID 60S. ALTHOUGH VERY DRY MID-LEVEL AIR WAS NOTED
ON WATER VAPOR IMAGERY MOVING INTO CENTRAL NORTH CAROLINA AS A
MODERATE MID-LEVEL SHORTWAVE MOVED FROM THE LOWER GREAT LAKES TOWARD
THE VIRGINIAS...ENOUGH MID-LEVEL MOISTURE AND MINIMAL SURFACE
INSTABILITY...AROUND 100J/KG ON THE SPC MESOANALYSIS...WAS AHEAD OF
THE FRONT TO PROVIDE FOR ISOLATED SHOWERS. THESE SHOWERS...MOVING
FROM WAKE INTO JOHNSTON COUNTY...WILL RESULT IN CONTINUED MENTION OF
AN ISOLATED SHOWER INTO THE EARLY MORNING UNTIL THE FRONT SHOULD
MOVE THROUGH.
FOR THE AFTERNOON...THE MODERATE MID-LEVEL SHORTWAVE SHOULD PASS
NORTH OF CENTRAL NORTH CAROLINA. 700MB AIR IS DRY UPSTREAM ON 00Z
UPPER-AIR ANALYSES...AND GFS BUFR SOUNDINGS ARE CAPPED TO DEEP
CONVECTION. THE NAM IS CERTAINLY MORE UNSTABLE AND SLOWER WITH THE
PROGRESS OF THE FRONT...BUT IT ALSO DIGS THE SHORTWAVE A LITTLE
FARTHER SOUTH AND ITS CURRENT TRAJECTORY ON WATER VAPOR SEEMS TO
SUPPORT THE GFS. CONVECTIVE-ALLOWING MODELS AND THE RAP ARE DRY
AFTER EARLY THIS MORNING...SAVE FAR SOUTHERN SAMPSON COUNTY CLOSER
TO THE FRONT WITH HEATING AND WHERE LOW-LEVEL SHOULD DRY LAST. IN
THE GRIDDED FORECASTS WILL NOTE A SLIGHT CHANCE OF A SHOWER SOUTH OF
CLINTON AND GOLDSBORO...OTHERWISE EXPECTING THE AFTERNOON TO BE DRY
WITH HIGH-BASED CU DEVELOPING. MIXING SHOULD PROVIDE FOR A FEW WIND
GUSTS FROM THE NORTH IN THE TEENS MPH BY MID-MORNING OR SO BEFORE
925MB WINDS DIMINISH. HIGH TEMPERATURES WILL BE FORECAST CLOSE TO
THOSE IMPLIED BY THE 1000-850MB THICKNESSES AND THE SLIGHTLY COOLER
MAV MOS GUIDANCE...MID 80S TO AROUND 90.
TONIGHT...GFS BUFR SOUNDINGS WOULD SUGGEST SOME OF THE SHALLOW...
HIGH-BASED CU COULD EXPAND SOME IN THE VERY LATE AFTERNOON AND
EVENING BEFORE DIMINISHING OVERNIGHT. WINDS WILL BE LIGHT AND MAINLY
NORTHEAST. THE NAM EMPHASIZES THE POTENTIAL FOR FOG...BUT THE GFS
OVERALL IS MUCH LESS OPTIMISTIC FOR THAT AND SREF PROBABILITIES FAIL
TO REGISTER. POSSIBLY SOME GROUND FOG IN ISOLATED PATCHES LATE
TONIGHT. OVERNIGHT LOWS IN THE LOWER TO MID 60S.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 305 AM WEDNESDAY...
GFS BUFR SOUNDINGS ARE AGAIN STABLE TO DEEP CONVECTION. ITS 850MB
THETA-E VALUES DO INCREASE...WITH A RELATIVE MAXIMUM IN K INDICES
AND 850MB UVV ON THE GFS MAINLY OVER THE SOUTHERN COASTAL PLAIN AND
SANDHILLS THURSDAY AFTERNOON. THE GFS FORECASTS A WEAK INVERTED
SURFACE TROUGH OVER CENTRAL NORTH CAROLINA THURSDAY AFTERNOON...
WHILE THE NAM IS MUCH SHARPER WITH THE TROUGH AS ITS FORECAST OF
HIGH PRESSURE IS SLOWER TO BUILD SOUTH. WINDS ALOFT ARE WEAK...AND 0-
3KM SHEAR IS WEAK AS WELL WITH LIGHT 925MB WINDS. CONVECTIVE-
ALLOWING MODELS REMAIN DRY...AND WITH LIMITED LOW-LEVEL FORCING
EXPECTED...LIMITED UPPER-LEVEL SUPPORT...AND POOR INSTABILITY
ESPECIALLY ON THE GFS WITH A CAPPED SET OF BUFR SOUNDINGS AND LOW-
LEVEL MLCAPE BARELY TO 100J/KG...WILL MAINTAIN A DRY FORECAST. IF
ANY SHOWER WOULD FORM IT SHOULD BE VERY ISOLATED. GIVEN THE HIGHER
850MB THETA-E VALUES EXPECT MORE CU OVER CENTRAL NORTH CAROLINA
OVERALL...SHADING HIGHS ABOUT A DEGREE BELOW THOSE OF TODAY UNDER
BASICALLY PERSISTENCE FOR 1000-850MB THICKNESSES. OVERNIGHT LOWS
THURSDAY NIGHT GENERALLY IN THE MID 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...
FAIR SEASONABLE WEATHER IS EXPECTED FOR THE LATE-WEEK AND WEEKEND
PERIOD WITH HIGH PRESSURE CENTERED TO OUR NORTH EXTENDING ACROSS OUR
AREA...AND THE MAJOR SYNOP SCALE WEATHER PLAYERS REMAINING EITHER
WELL TO OUR NORTH OR TO OUR SOUTH...WITH THE NEAREST NOTABLE FEATURE
BEING THE REMNANT SFC BOUNDARY LOCATED JUST OFF THE EAST COAST.
MOISTURE POOLING INVOF OF THIS BOUNDARY MAY MOVE BACK TOWARD THE
COAST OVER THE WEEKEND...SO IT`S POSSIBLE THAT AN ISOLD SEA BREEZE
SHOWER COULD AFFECT OUR FAR SE ZONE (SOUTHERN SAMPSON CO) SAT AND
SUN AFTERNOON...BUT RIGHT NOW THE RISK IS TOO SMALL TO INCLUDE IN
THE FORECAST. WITH LOW LEVEL THICKNESSES GRADUALLY RECOVERING
THROUGH THE WEEK...HIGHS FRI THRU SUN WILL APPROACH 90 IN MANY
SPOTS...AND LOWS IN THE MID-UPR 60S...SO NORMAL TO SLIGHTLY ABOVE
NORMAL TEMPS DURING THIS TIME.
EARLY NEXT WEEK...THE UPPER RIDGE OVER THE WESTERN ALTANTIC WILL
MOVE WWD TOWARD THE GOMEX...WHILE A SHORT WAVE IN THE WESTERLIES
AMPLIFIES OVER THE TN VALLEY AS IT APPROACHES THE CAROLINAS. AS THE
RIDGE MOVES TOWARD THE GOMEX...NORTHWARD MOISTURE TRANSPORT WILL
MARKEDLY INCREASE AROUND THE PERIPHERY OF THE RIDGE...AND THAT WILL
HELP SET THE STAGE FOR SCATTERED SHOWERS/TSTMS ACROSS OUR AREA ON
TUESDAY AS THE SHORT WAVE APPROACHES FROM THE WEST. SO FOR NOW...
WILL KEEP POPS LOW ON MONDAY...ALBEIT WITH INCREASING CLOUDS...THEN
RAIN CHANCES RETURN MONDAY NIGHT AND TUESDAY AS THE SHORT WAVE
APPROACHES. TEMPS WILL CONTINUE TO RUN ABOVE NORMAL ON MONDAY BUT
COOLING SEVERAL DEGREES ON TUESDAY DUE TO CLOUDS AND RAIN.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 150 AM WEDNESDAY...
VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA THROUGH
THE 06Z VALID TAF PERIOD...OUTSIDE OF PATCHY MOSTLY MVFR LIGHT FOG
THIS MORNING...AND AN ISOLATED SHOWER AHEAD OF A COLD FRONT SLOWLY
MOVING THROUGH THE AREA. WINDS VEER TO NORTHERLY BEHIND THE FRONT
WITH A FEW GUSTS IN THE TEENS KNOTS WITH MIXING BEFORE WINDS
DIMINISH BY EARLY AFTERNOON. SURFACE WINDS SHOULD BACK SLIGHTLY MORE
NORTHWEST THIS AFTERNOON THEN VEER BACK TO LIGHT NORTHEAST THIS
EVENING AS HIGH PRESSURE SLOWLY BUILDS IN.
BEYOND THE 06Z VALID TAF PERIOD...NAM MET MOS GUIDANCE FAVORS SOME
AREAS OF FOG DURING THE EARLY MORNING HOURS OF BOTH THURSDAY AND
FRIDAY. HOWEVER...THE GFS GUIDANCE IS MUCH LESS FOCUSED ON FOG
EXCEPT AT KRWI THURSDAY MORNING...AND SREF PROBABILITIES FOR LOW
VISIBILITIES HARDLY REGISTER BOTH EARLY THURSDAY AND EARLY FRIDAY
MORNINGS. GIVEN SOME VERY LOW-LEVEL MOISTURE AND AREAS OF COOLER LOW
TEMPERATURES...PATCHY GROUND FOG SEEMS A POSSIBILITY...BUT
CONFIDENCE IN THAT AT SPECIFIC TAF SITES IS LOW. OTHERWISE...VFR
CONDITIONS ARE EXPECTED OVERALL THROUGH SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...RAH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1246 AM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 1245 AM CDT WED AUG 12 2015
HAVE DROPPED ALL POPS FOR THE OVERNIGHT BASED ON IR SATELLITE
SHOWING RAPIDLY WARMING TOPS / CLOUDS DISSIPATING.
UPDATE ISSUED AT 927 PM CDT TUE AUG 11 2015
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE AS VERY ISOLATED
CELLS ACROSS EASTERN MONTANA MAY LIKELY QUICKLY FADE AND NOT CROSS
THE BORDER INTO NORTH DAKOTA AS THE BOUNDARY LAYER DECOUPLES. THE
00-01 UTC HRRR RUNS SUGGEST A POTENTIAL FOR THUNDERSTORMS LATE
TONIGHT FAR NORTH NEAR THE INTERNATIONAL BORDER IN ASSOCIATION
WITH A WEAK IMPULSE ACROSS NORTHEAST MONTANA AS OF 0230 UTC AND
THE DEVELOPMENT OF A MODEST LOW LEVEL JET. HOWEVER...THIS SCENARIO
DOES CARRY PLENTY OF UNCERTAINTY.
UPDATE ISSUED AT 642 PM CDT TUE AUG 11 2015
AS OF 2345 UTC...ISOLATED CONVECTION ACROSS EASTERN MONTANA HAS
BEEN SLOW TO DEVELOP AND MAINTAIN ITSELF. THE 20-22 UTC HRRR RUNS
HAVE CONTINUED TO OVER DEVELOP CONVECTION THUS FAR AND WILL
DISCOUNT THEIR SOLUTIONS. WILL STILL MAINTAIN AN ISOLATED MENTION
OF THUNDERSTORMS THROUGH SUNSET GENERALLY ALONG AND WEST OF
HIGHWAY 85 AHEAD OF THE UPPER LEVEL IMPULSE ACROSS SOUTHEAST
MONTANA. ANY STORM THAT ENTERS THE STATE COULD POSE A SEVERE WIND
THREAT WITH HIGH STORM BASES. HOWEVER THE THREAT WILL BE ISOLATED.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN FORECAST ISSUE IN THE SHORT TERM PERIOD WILL BE THUNDERSTORM
CHANCES THIS AFTERNOON/EVENING AND AGAIN WEDNESDAY
AFTERNOON/EVENING.
LATEST SATELLITE IMAGERY SHOWS CLEAR SKIES ACROSS WESTERN AND
CENTRAL NORTH DAKOTA...BUT A SHORTWAVE IS INDICATED OVER NORTHWEST
WYOMING/SOUTH CENTRAL MONTANA. THIS SHORTWAVE WILL TRACK OVER THE
TOP OF AN UPPER LEVEL RIDGE THAT EXTENDS FROM THE DESERT SOUTHWEST
INTO EASTERN MONTANA. THE FORCING FROM THIS WAVE/COMBINED WITH
DAYTIME SURFACE HEATING SHOULD BE ENOUGH TO PRODUCE SOME ISOLATED
CONVECTION OVER EASTERN MONTANA LATE THIS AFTERNOON...POSSIBLY
TRACKING INTO WESTERN NORTH DAKOTA THIS EVENING. WITH A BUILDING
UPPER RIDGE...CAPPING WILL BE A LIMITING FACTOR. BUT IF STORMS DO
FORM WE COULD SEE A STRONG OR POSSIBLY SEVERE STORM DUE TO THE
INSTABILITY. WITH THE EXPECTED LIMITED COVERAGE...WILL NOT MENTION
SEVERE WORDING IN THE WEST THIS EVENING.
THE AFOREMENTIONED WAVE...AND A NORTHERN STREAM WAVE WILL KEEP A
CHANCE OF THUNDERSTORMS MAINLY ACROSS SOUTHERN CANADA AND INTO THE
NORTHERN GREAT LAKES REGION LATE TONIGHT AND WEDNESDAY. WE COULD
SEE A STORM OR TWO AS FAR SOUTH AS THE NORTHERN FORECAST AREA
DURING THIS PERIOD...BUT FOR NOW WILL STICK WITH A DRY FORECAST
LATE TONIGHT AND WEDNESDAY. WEDNESDAY IS EXPECTED TO BE EVEN
HOTTER THAN TODAY WITH HIGHS IN THE MID TO UPPER 90S ACROSS MOST
OF WEST AND CENTRAL NORTH DAKOTA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM CDT TUE AUG 11 2015
MAIN CONCERNS IN THE LONG TERM INCLUDE VERY WARM CONDITIONS
ASSOCIATED WITH A LARGE UPPER LEVEL RIDGE OVER THE CENTRAL
US...BRINGING FORECAST HIGH TEMPERATURES IN THE 90S WEDNESDAY
THROUGH FRIDAY. ON WEDNESDAY A MID-LEVEL THERMAL CAP SHOULD BE IN
PLACE ACROSS THE DAKOTAS. A LOW LEVEL JET WILL BE IN PLACE WITH
PLENTY OF LOW LEVEL MOISTURE WITH DEWPOINTS IN THE 60S. AN UPPER
LEVEL SHORTWAVE IS FORECAST TO MOVE THROUGH THE RIDGE ACROSS MONTANA
AND WYOMING ON WEDNESDAY...APPROACHING THE DAKOTAS WEDNESDAY NIGHT.
A WEAK SURFACE TROUGH IS FORECAST TO DEVELOP SOUTHWEST TO NORTHEAST
ACROSS THE STATE AS WELL. THIS MAY PROVIDE ENOUGH INSTABILITY TO
OVERCOME A MID-LEVEL CAP...ESPECIALLY AFTER SUNSET. HAVE SMALL
CHANCES OF THUNDERSTORMS WEDNESDAY NIGHT - SOME STORMS COULD
BE STRONG...WITH CONVECTION PERHAPS ABLE TO CONTINUE THROUGH
THURSDAY MORNING. THE UPPER LEVEL SHORTWAVE MOVES ACROSS NORTH
DAKOTA ON THURSDAY...WITH THE SURFACE BOUNDARY BECOMING A COLD FRONT
AS IT SAGS SOUTH. THE NAM ALIGNS THE COLD FRONT WEST-TO-EAST ACROSS
SOUTHERN NORTH DAKOTA THURSDAY AFTERNOON. THUS EVEN WITH VERY WARM
AIR AT MID LEVELS...THE CAP MAY BREAK THURSDAY AFTERNOON TO BRING
SCATTERED THUNDERSTORMS TO SOUTHERN NORTH DAKOTA...LINGERING INTO
THURSDAY EVENING. FRIDAY SHOULD BE MAINLY DRY AS THE UPPER LEVEL
RIDGE REMAINS IN PLACE WITH NO OBVIOUS SHORTWAVES OR SURFACE
FEATURES TO BREAK THE STRONG MID-LEVEL CAP.
THE UPPER LEVEL RIDGE BEGINS TO BREAK DOWN FRIDAY NIGHT WITH A
STRONG COLD FRONTAL SYSTEM MOVING EAST ACROSS THE NORTHERN PLAINS
THROUGH SATURDAY. CHANCES OF SHOWERS AND THUNDERSTORMS FRIDAY NIGHT
THROUGH SATURDAY NIGHT. HIGHS SUNDAY IN THE 70S TO LOWER 80S.
CHANCES OF SHOWERS AND THUNDERSTORMS AGAIN SUNDAY NIGHT THROUGH
TUESDAY NIGHT AS ANOTHER UPPER LEVEL LOW MOVES EAST OUT OF THE
ROCKIES AND ACROSS THE NORTHERN PLAINS. HIGH TEMPERATURES MAINLY IN
THE 70S.
WITH GRASSES CURING AND VERY WARM CONDITIONS THIS WEEK...THIS MAY
SET THE STAGE FOR FUTURE FIRE WEATHER CONCERNS. ALTHOUGH WINDS
SHOULD NOT BE STRONG THIS WEEK...ANY DRY AND WINDY DAYS BEYOND THIS
WEEK MAY POSE FOR HEIGHTENED FIRE WEATHER CONCERNS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1245 AM CDT WED AUG 12 2015
VFR ARE FORECAST ACROSS WESTERN AND CENTRAL NORTH DAKOTA FOR THE
06 UTC TAF PERIOD WITH A VERY WARM AIRMASS IN PLACE.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...TWH
LONG TERM...TWH
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS NORMAN OK
258 AM CDT WED AUG 12 2015
.DISCUSSION...
THIS MORNING... SCATTERED SHOWERS CONTINUE TO EVOLVE ACROSS SERN KS
INTO FAR NWRN OK. THIS ACTIVITY IS BEING DRIVEN ALONG A MID-LEVEL
BAROCLINC ZONE OF MOISTURE AND ASCENT WITH THE H700 HIGH CENTERED
OVER THE LLANO ESTACADO IN W CENTRAL TX NEAR LUBBOCK PER SPC
MESOANALYSIS. GOOD REPRESENTATION OF CORRIDOR OF MOISTURE AND ASCENT
CAN BE VISUALIZED ON THE 310 AND 315K ISENTROPIC SURFACES. LATEST
RUNS OF THE HRRR THIS MORNING APPEAR TO BE A TAD BULLISH THROUGH
SUNRISE... DEVELOPING A FAIRLY WIDE AREA OF PRECIP ACROSS SWRN KS
INTO THE NERN PANHANDLES AND NWRN OK. HOWEVER... THE 12/00Z RUN OF
ARW/NMM WRFS ARE ALSO A TAD AGGRESSIVE WITH CONVECTION. SHORT RANGE
SOLUTIONS FROM THE NAM/GFS/ECMWF SUGGEST A SLIGHT UPTICK IN THE LLJ
THROUGH 12Z. IF THIS OCCURS... WE COULD SEE SOME INCREASED
CONVECTIVE DEVELOPMENT THROUGH SUNRISE... MAYBE NOT ON THE ORDER OF
THE HRRR/WRF... BUT MORE THAN WHATS BEEN OCCURRING THROUGH 08Z (3
AM). EITHER WAY... EXPECT AT LEAST SCATTERED DEVELOPMENT TO PERSIST
THROUGH THE MORNING AND LINGER THROUGH THE AFTN ACROSS W/NW OK.
THIS AFTERNOON... BESIDES LINGERING SHOWER/THUNDERSTORM CHANCES...
INCREASING CLOUD COVER THIS AM ACROSS W/NW OK WILL HAVE AN IMPACT ON
AFTN TEMPS. HIGHS THIS AFTN WILL STRUGGLE TO CLIMB INTO THE UPPER
80S... LIKELY SETTLING IN THE MID 80S ACROSS NWRN OK. ELSEWHERE...
EXPECT UPPER 80S TO MID 90S FROM CENTRAL OK INTO NRN TX.
TONIGHT... CONTINUE TO KEEP A SLIGHT CHANCE FOR SCATTERED SHOWERS
AND THUNDER GOING FOR W/NW OK THROUGH THU AM. WITH THE H500 RIDGE
GOING NOWHERE FAST... MID-LEVEL MOISTURE WILL HOLD AND ASCENT WILL
BE SIMILAR TO THIS MORNING... KEEPING A LOW CHANCE FOR ISOLATED TO
SCATTERED CHCS.
FOR THE REMAINDER OF THE WEEK... SEASONABLE TEMPS WILL HOLD THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. THERE ALSO REMAINS A SLIGHT
CHANCE OF SCATTERED SHOWERS AND THUNDERSTORMS FRI ACROSS PORTIONS OF
WRN OK/WRN N TX AS A WEAK H500 SHORTWAVE TRAVERSES THE HIGH. CHCS
WILL LINGER INTO EARLY SAT. OTHER THAN THAT... EXPECT A DRY AND
PLEASANT SUMMER WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 88 66 90 68 / 10 10 0 10
HOBART OK 91 69 94 71 / 10 10 10 0
WICHITA FALLS TX 93 71 95 72 / 10 10 0 0
GAGE OK 86 66 91 70 / 40 20 0 0
PONCA CITY OK 89 65 90 69 / 10 0 0 0
DURANT OK 95 70 94 67 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1236 AM CDT WED AUG 12 2015
.DISCUSSION...FOR 06Z TAFS
&&
.AVIATION...COULD BE SOME BRIEF MVFR VSBY IN FOG AT ALI/VCT
TOWARD DAYBREAK AND WILL CONTINUE MENTION IN A TEMPO GROUP THERE.
STILL LOOKS LIKE BEST CHANCE FOR ANY CONVECTION TODAY WILL BE
AROUND VCT AND WILL MAINTAIN THE PROB30 FOR A GUSTY STORM. OTHW
VFR CONDS WILL CONTINUE.
&&
.PREV DISCUSSION... /ISSUED 1034 PM CDT TUE AUG 11 2015/
DISCUSSION...UPDATE TO REMOVE RAIN CHANCES FOR VICTORIA AREA
AS CONVECTION HAS DISSIPATED.
PREV DISCUSSION... /ISSUED 756 PM CDT TUE AUG 11 2015/
DISCUSSION...CONVECTION CONTINUES TO MOVE SOUTHWESTWARD FROM
THE UPPER TEXAS COAST EARLY THIS EVENING. THIS ACTIVITY MAY
CONTINUE TO HOLD TOGETHER FOR A FEW MORE HOURS BEFORE AIR MASS
STABILIZES WITH LOSS OF DAYTIME HEATING. 23Z HRRR MODEL SHOWS
THIS POSSIBILITY. GOES SOUNDER SHOWS SUFFICIENT MOISTURE REMAINS
OVER THE VICTORIA CROSSROADS WHILE THE AIR MASS IS SLIGHTLY DRIER
OVER THE COASTAL BEND. SOME OF THESE STORMS MAY PRODUCE STRONG
GUSTY WINDS OVER THE VICTORIA CROSSROADS.
PREV DISCUSSION... /ISSUED 640 PM CDT TUE AUG 11 2015/
DISCUSSION...UPDATED FOR 00Z AVIATION.
AVIATION...WILL KEEP MAINLY VFR CONDITIONS THROUGH TONIGHT...BUT
TSRA NOTED NORTHEAST OF VCT TAF SITE. THINK THESE STORMS SHOULD
REMAIN NORTH OF THE AREA...BUT WILL MONITOR. COULD SEE A BIT OF
FOG ONCE AGAIN TOWARD SUNRISE...HAVE TEMPO MVFR GROUPS. DURING THE
DAY TOMORROW...MOST SITES REMAIN VFR. TSRA COULD APPROACH VCT SITE
DURING THE AFTERNOON...HAVE PROB30 FOR THAT SITE DURING THE DAY.
ALI AND CRP HAVE A SLIGHT CHANCE FOR CONVECTION AS WELL...BUT TOO
SMALL TO INCLUDE IN TAFS AT THIS TIME.
PREV DISCUSSION... /ISSUED 241 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...MAIN ISSUE IS THE
CHANCE FOR RAIN...WHICH IS NOT STRAIGHT-FORWARD SINCE MESO-SCALE
INFLUENCES WILL PLAY SOME ROLE IN HOW FAR SOUTH AND WEST CONVECTION
GOES (AND HOW MUCH AREA GETS). MOST MODELS KEEP AT LEAST A BIT OF A
CAP/CIN BUT IT GETS CLOSE TO BREAKING AND ANY STORM WHICH BREAKS THE
CAP (GIVEN DAYTIME TEMPERATURES) COULD INITIATE MORE CONVECTION VIA
COOLING AND/OR CONVERGENCE.
FOR TONIGHT...THINK ANY CONVECTION WHICH DEVELOPS NORTH OF THE CWFA
WILL REMAIN NORTH (THIS AGREES WITH THE LATEST HRRR AND TTU SMALL
SCALE MODELS...AND TO A LESSER DEGREE THE MSSL MODEL RUN AT 11/00Z).
FOR WEDNESDAY...MOISTURE GETS BETTER AND CONVERGENCE ALONG THE
BOUNDARY (MAINLY NORTH) COULD TRIGGER CONVECTION WHICH COULD MOVE
INTO THE CWFA IN THE AFTEROOON AND EVENING BEFORE ENDING. THUS...
WILL MAINTAIN THE HIGHER POPS TO THE NORTH/NORTHEAST WEDNESDAY AND
NEAR THE COAST WEDNESDAY NIGHT...BUT WILL MENTION AT LEAST A SLIGHT
CHANCE FOR RAIN ALL LOCATIONS WEDNESDAY AFTERNOON AND WEDNESDAY
EVENING.
OTHER THAN THAT...STILL LOOKS LIKE A HOT DAY ON WEDNESDAY WITH
BOUNDARY/FRONT TO THE NORTH. HAVE GONE ON THE WARM SIDE OF GUIDANCE
FOR TEMPERATURES ON WEDNESDAY. CONCERNING LOWS...A BIT TRICKER AS
MOST MODEL 2 METER TEMPERATURES ARE QUITE WARM BUT ALSO SHOWING
LIGHT SOUTHWEST WINDS AND ABOUT THE SAME IF NOT COOLER BOUNDARY
LAYER TEMPERATURES. AM GOING WITH MORE OF A CONSENSUS FORECAST (BUT
A TAD WARMER THAN THIS MORNING DUE TO AFOREMENTIONED TEMPERATURES)
FOR WEDNESDAY`S LOW TEMPERATURES...AND EVEN A BIT WARMER WEDNESDAY
NIGHT/THURSDAY MORNING. OBVIOUSLY ANY CONVECTION OVERNIGHT (WHICH IS
NOT EXPECTED TO BE MORE THAN ISOLATED AND MAINLY IN THE EVENING)
COULD LOWER TEMPERATURES MORE THAN EXPECTED. FINALLY...GENERALLY
LIGHT WINDS AND MORE CLOUDS ON WEDNESDAY THAN TODAY.
$$
MARINE (TONIGHT THROUGH WEDNESDAY NIGHT)...A WEAK GRADIENT WILL
PERSIST WITH FRONT/BOUNDARY TO THE NORTH. WINDS WILL HAVE TROUBLE
MAKING IT BEYOND 10-12 KNOTS THROUGH THE PERIOD...MAYBE WEDNESDAY
NIGHT. MAINLY A SLIGHT CHANCE FOR SHOWERS/STORMS WEDNESDAY AND
WEDNESDAY NIGHT...BUT DID GO A BIT HIGHER OVER THE NORTHEAST
PROXIMATE TO BETTER FORCING AND LIMITED CAP.
LONG TERM (THURSDAY THROUGH TUESDAY)...EXTENDED BEGINS WITH UPPER
RIDGE AXIS STILL FAR ENOUGH WEST TO LIMIT CONVECTIVE CAP AND
MAINTAIN RAIN CHANCES ACROSS THE COASTAL BEND. RIDGE AXIS THEN
WOBBLES EASTWARD THROUGH THE WEEKEND...RESULTING IN DRY AND WARM
WEATHER.
BY MONDAY MODELS PROJECT THE NEXT IMPULSE REACHING THE GREAT LAKES
TO EXTEND SOUTHWEST DOWN UNDER THE BULK OF THE RIDGE...COOLING
TEMPERATURES ALOFT. IF THIS PANS OUT...IT WILL HAVE THE DOUBLE
EFFECT OF REINTRODUCING LOW POPS AND COOLING TEMPERATURES BY FIVE OR
SO DEGREES.
TEMPERATURES WILL REMAIN ABOVE NORMAL THROUGH THE WEEKEND...WITH
ELEVATED HEAT INDICES AS WELL. HIGHS MAY RELAX A BIT TOWARD THE END
OF THE PERIOD...WITH READINGS CLOSER TO NORMAL FOR MID AUGUST.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 99 77 96 77 95 / 20 20 30 10 10
VICTORIA 101 76 98 76 98 / 30 30 30 10 10
LAREDO 103 80 104 80 102 / 10 20 20 10 10
ALICE 102 76 100 76 100 / 20 20 30 10 10
ROCKPORT 96 79 93 80 92 / 30 30 30 10 10
COTULLA 104 79 103 78 102 / 20 20 20 10 10
KINGSVILLE 101 76 98 76 97 / 20 20 30 10 10
NAVY CORPUS 94 80 91 80 90 / 20 20 30 10 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
TJ/70...AVIATION
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1231 AM CDT WED AUG 12 2015
.AVIATION...
/06Z TAFS/
MID TO UPPER LEVEL CLOUDS WILL CONTINUE TO SPREAD WESTWARD AND
OVER MUCH OF THE AREA FROM EARLIER CONVECTION ACROSS EAST TEXAS
THROUGH WEDNESDAY MORNING. A COOL FRONT IS FORECAST TO PUSH
ACROSS THE NORTHERN PART OF SOUTH CENTRAL TEXAS ON WEDNESDAY AND
PRODUCE SLIGHT TO LOW END CHANCES OF RAIN ACROSS PARTS OF THE
SOUTHERN HALF OF THE AREA. WINDS WILL GENERALLY BE LIGHT AND
VARIABLE OVERNIGHT WITH A NORTHERLY COMPONENT EXPECTED ON
WEDNESDAY. SHOWERS/ISOLATED STORMS MAY AFFECT THE KSAT/KSSF AND
KDRT TERMINALS DURING THE LATE AFTERNOON/EARLY EVENING HOURS.
OVERALL...VFR CONDITIONS ARE EXPECTED ACROSS AREA SITES THROUGH
MUCH OF THE FORECAST PERIOD.
&&
.PREV DISCUSSION... /ISSUED 755 PM CDT TUE AUG 11 2015/
UPDATE...
VERY ISOLATED SHOWERS AND STORMS CONTINUE TO BE OBSERVED FROM THE
HILL COUNTRY TO THE COASTAL PLAINS THIS EVENING. THERE IS A STRONG
MOISTURE AND INSTABILITY GRADIENT DRAPED OVER BASICALLY THE I35
CORRIDOR WHICH HAS PREVENTED MUCH ACTIVITY FROM SURVIVING BEYOND
THAT POINT. FARTHER EAST...COLD POOL DYNAMICS HAVE TAKEN OVER AND
GENERATED A SEVERE CLUSTER OF STORMS JUST EAST OF THE LAVACA
COUNTY LINE AND ARE MOVING SOUTHWEST. SHOULD MISS THE CWA MOSTLY
WITH ONLY ISOLATED STORMS PRESENT THROUGH 10 PM. THREAT CONTINUES
TO REMAIN MOSTLY GUSTY WINDS OF UP TO 40 MPH THROUGH THE MID
EVENING. QUICKLY AFTER NIGHTFALL...CONDITIONS WILL BECOME QUIETER.
UPDATED HOURLY GRIDS TO MESH WITH LATEST OBS AND POPULATED HOURLY
WIND GRIDS WITH HRRR AS IT WAS PERFORMING WELL WITH THE OUTFLOW
WINDS GENERATED BY THIS ISOLATED CONVECTION.
ALSO...THE HEAT ADVISORY WAS ALLOWED TO EXPIRE AT 8PM. UPDATED
THE PRODUCT SUITE TO REMOVE THE ADVISORY WORDING.
PREV DISCUSSION... /ISSUED 641 PM CDT TUE AUG 11 2015/
AVIATION...
ISOLD SHRA/TSRA WILL LINGER UNTIL A LITTLE AFTER SUNSET EAST OF A
KAQO TO KT20 TO KARM LINE. KAUS HAS BEST CHANCE. HOWEVER...WILL
LEAVE OUT AS PROBS LESS THAN 20. DAYTIME HEATING INTERACTING WITH
A WEAK FRONTAL ZONE AND DEEPER MOISTURE DRIFTING TO THE SOUTHWEST
WILL ALLOW ISOLD/SCT SHRA/TSRA TO DEVELOP ON WEDNESDAY. BEST
CHANCES WILL BE ALONG AND SOUTH OF A KDRT TO KBAZ TO K3T5 LINE.
WILL MENTION AT KSAT/KSSF AFTER 12/20Z AND KDRT AFTER 12/22Z WITH
PROB30S. SKIES WILL BE VFR AS BELOW 3K FT DRIES OUT AND ABOVE 3K
MOISTENS UP. THE WEAK COLD FRONT WILL DRIFT TO THE SOUTHWEST WITH
MAINLY SELY WINDS 10 KTS OR LESS SHIFTING TO MAINLY NELY.
DOWNBURST WIND GUSTS UP TO 45 KTS ARE POSSIBLE IN/NEAR SHRA/TSRA.
PREV DISCUSSION... /ISSUED 315 PM CDT TUE AUG 11 2015/
SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...
ANOTHER DAY OF ABOVE NORMAL WARMTH CONTINUES THIS AFTERNOON WITH
TEMPERATURES IN THE UPPER 90S TO NEAR 105 DEGREES ACROSS SOUTH
CENTRAL TEXAS. BASED ON RECENT OBSERVATIONS AND SHORT RANGE
GUIDANCE...WE WILL CONTINUE THE HEAT ADVISORY TODAY. THE HEAT
CONTINUES TOMORROW AND BASED ON THE LATEST GUIDANCE...WE COULD SEE A
FEW SPOTS ALONG AND EAST OF I-35 NEAR HEAT ADVISORY LEVELS DURING
THE AFTERNOON AND EARLY EVENING HOURS. FOR NOW...WILL HOLD OFF ON
EXTENDING THE ADVISORY AND AWAIT ANOTHER ROUND OR TWO OF TEMPERATURE
GUIDANCE. OTHERWISE...WE/LL MAINTAIN A VERY LOW CHANCE FOR SHOWERS
AND THUNDERSTORMS INTO THE EARLY EVENING HOURS FOR AREAS GENERALLY
ALONG AND EAST OF A BURNET TO CUERO LINE. WE EXPECT MOST ACTIVITY
WILL BE TIED CLOSELY TO DIURNAL HEATING...SO WILL NOT MENTION ANY
RAIN CHANCES FOR TONIGHT. ON WEDNESDAY...WE EXPECT ANOTHER SHOT FOR
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS AS THE REMNANTS OF A
WEAK COLD FRONT ALONG WITH AN INCREASE IN MID-LEVEL MOISTURE MOVES
INTO SOUTH CENTRAL TEXAS. MOISTURE LEVELS REMAIN HIGHEST ALONG AND
SOUTH OF THE THE HIGHWAY 90 CORRIDOR...SO WE/LL MENTION HIGHER
RAIN CHANCES ACROSS THIS REGION.
LONG TERM (THURSDAY THROUGH TUESDAY)...
DRIER AIR IN THE LOW-LEVELS FILTERS INTO SOUTH CENTRAL TEXAS ON
THURSDAY. THIS WILL RESULT IN MOST AREAS NORTH OF HIGHWAY 90
REMAINING DRY...WITH A 20-30% CHANCE FOR RAIN GENERALLY ALONG AND
SOUTH OF HIGHWAY 90. THE MID-LEVEL MOIST AXIS CONTINUES TO SHIFT
WESTWARD ON FRIDAY AND WE/LL ONLY MENTION ISOLATED CONVECTION
ACROSS THE SOUTHERN EDWARDS PLATEAU...WITH DRY WEATHER ELSEWHERE.
FOR THE REMAINDER OF THE FORECAST PERIOD...THE MEDIUM RANGE MODELS
CONTINUE TO SHOW A WEAK UPPER LOW/TROUGH DEVELOPING OVER THE LOWER
MS RIVER VALLEY THIS WEEKEND. THIS FEATURE IS THEN EXPECTED TO
RETROGRADE THROUGH EARLY NEXT WEEK. THE MODELS ARE SHOWING SOME
FAIRLY SIGNIFICANT DIFFERENCES WITH REGARDS TO THE STRENGTH AND
LOCATION OF THIS LOW/TROUGH. FOR NOW...WE/LL KEEP RAIN CHANCES
CONFINED TO THE COASTAL PLAINS AND LEAVE THE REMAINDER OF THE AREA
DRY. AS FOR TEMPERATURES THROUGH THE PERIOD...ABOVE NORMAL WARMTH
IS EXPECTED THROUGH SATURDAY...WITH READINGS DROPPING CLOSER TO
NORMAL FOR EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 79 101 77 100 76 / 10 - - - -
AUSTIN BERGSTROM INTL AIRPORT 75 100 73 99 73 / 10 10 - - -
NEW BRAUNFELS MUNI AIRPORT 77 101 75 100 74 / 10 10 - - 10
BURNET MUNI AIRPORT 76 98 74 98 74 / - 10 - 10 10
DEL RIO INTL AIRPORT 78 103 79 101 78 / 20 20 - 10 10
GEORGETOWN MUNI AIRPORT 77 99 74 98 74 / - - - - -
HONDO MUNI AIRPORT 76 102 75 99 74 / 20 20 - - -
SAN MARCOS MUNI AIRPORT 78 101 76 98 75 / 10 10 - - 10
LA GRANGE - FAYETTE REGIONAL 77 101 75 99 74 / 10 10 - - 10
SAN ANTONIO INTL AIRPORT 80 101 77 98 76 / 20 10 - - -
STINSON MUNI AIRPORT 80 102 77 100 76 / 20 20 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...17
SYNOPTIC/GRIDS...RUNYEN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1142 PM CDT TUE AUG 11 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 240 PM CDT TUE AUG 11 2015
MUCH OF THE PERIOD LOOKS TO BE QUIET AS HIGH PRESSURE DOMINATES
THE REGION. THIS HIGH IS CURRENTLY CENTERED OVER NEBRASKA WITH THE
RIDGE AXIS EXTENDING NORTH WELL INTO ONTARIO. THE HIGH IS EXPECTED
TO DRIFT EAST TONIGHT AND BE OVER THE AREA SETTING UP THE
POSSIBILITY OF VALLEY FOG. THE 11.12Z NAM FORECAST SOUNDING FOR
KLSE LATE TONIGHT HAS LIGHT WINDS OF 10 KNOTS OR LESS ONLY UP
THROUGH ABOUT 3000 FEET AND WHILE IT SHOWS SATURATION OCCURRING AT
THE SURFACE...IT IMMEDIATELY BECOMES VERY DRY JUST ABOVE THE
SURFACE. THE 11.17Z RAP FORECAST SOUNDING IS EVEN MORE PESSIMISTIC
AS IT DOES NOT SHOW SATURATION OCCURRING AT THE SURFACE AND HAS A
3C TEMP/DEW POINT SPREAD AT 12.11Z. FOR NOW...WILL LEAVE THE
MENTION OF PATCHY VALLEY FOG IN THE FORECAST IN CASE THE NAM
SOUNDING ENDS UP BEING MORE CORRECT BUT WOULD TEND TO THE THINK
WITH THE LACK OF A DEEPER LAYER OF LIGHT WINDS AND SATURATION THAT
THERE WILL BE VERY LITTLE FOG IN THE VALLEYS.
ALL THE 11.12Z MODELS HAVE TRENDED TOWARD KEEPING THE SURFACE
RIDGE OVER THE REGION LONGER THAN PREVIOUS MODEL RUNS. THE UPPER
LEVEL RIDGE AXIS REMAINS OVER THE EASTERN ROCKIES INTO THE
NORTHERN HIGH PLAINS WHICH ENDS UP PUSHING THE SYSTEM CROSSING
CANADA FARTHER TO THE NORTH. THE MODELS CONTINUE TO SHOW A WEAK
SHORT WAVE TROUGH UNDERNEATH THE MAIN SYSTEM BUT THIS SHOULD NOW
PASS EVEN FARTHER TO THE NORTHEAST AND OVER THE NORTHERN GREAT
LAKES FOR WEDNESDAY NIGHT INTO THURSDAY. WITH THE STRONGER LOW
LEVEL RIDGING...THE WEAK COLD FRONT HAS A HARD TIME WORKING SOUTH
AND ALL THE MODELS NOW SHOW THIS REMAINING TO THE NORTH OF THE
AREA WEDNESDAY NIGHT. WITH THE LACK OF SIGNIFICANT FORCING AND THE
FRONT STAYING TO THE NORTH...HAVE REMOVED THE RAIN CHANCES FOR
WEDNESDAY NIGHT.
THERE IS STILL A TREND FOR THE UPPER LEVEL HEIGHTS TO LOWER SOME
THURSDAY INTO THURSDAY NIGHT AS THE UPPER LEVEL RIDGE SHIFTS
SLIGHTLY TO THE WEST. THIS MAY ALLOW A SHORT WAVE TROUGH TO TOP
THE RIDGE AXIS AND THEN SLIDE SOUTHEAST ACROSS THE REGION. IF THE
11.12Z GFS IS CORRECT...THIS WAVE COULD PRODUCE SOME MODERATE PV
ADVECTION IN THE 500-300 MB LAYER AS IT COMES ACROSS THE REGION.
WHAT LOW LEVEL MOISTURE TRANSPORT THERE IS LOOKS TO WRAP AROUND
THE LOW LEVEL RIDGE AND ACTUALLY COME BACK INTO THE AREA FROM THE
NORTHWEST. OVERALL...THE SIGNAL LOOKS PRETTY WEAK FOR RAIN AS THE
FRONT TRIES TO PUSH INTO THE REGION AND BOTH THE NAM AND 11.12Z
ECMWF KEEP THE AREA DRY WITH ANY RAIN OFF TO THE EAST. THE GFS
CONTINUES TO BE THE MOST ROBUST WITH RAIN AND WILL HONOR ITS
SOLUTION WITH SOME 20 TO 30 PERCENT RAIN CHANCES.
.LONG TERM...(FRIDAY THROUGH TUESDAY)
ISSUED AT 240 PM CDT TUE AUG 11 2015
THERE COULD BE SOME LINGERING RAIN CHANCES ACROSS THE EAST INTO
FRIDAY FROM THIS SYSTEM...OTHERWISE IT LOOKS TO BE DRY THROUGH
SATURDAY NIGHT. THE RIDGE AXIS IS THEN EXPECTED TO GET FLATTENED
WITH A NEARLY ZONAL FLOW OVER THE UPPER MIDWEST AS A POSITIVE TILT
SYSTEM MOVES ACROSS SOUTHERN CANADA. THE CONCERN WITH THIS SYSTEM
IS HOW FAR SOUTH WILL THE TAIL OF THE SHORT WAVE TROUGH EXTEND.
THE GFS AND 11.12Z GEM ESSENTIALLY SHOW THIS SYSTEM STAYING WELL
TO THE NORTH WHILE THE ECMWF IS STRONGER WITH THE TAIL END OF THE
SYSTEM AND BRINGS A DECENT SECONDARY SHORT WAVE TROUGH ACROSS
SUNDAY AND SUNDAY NIGHT. A COLD FRONT SHOULD GET PUSHED INTO THE
AREA WITH THIS SYSTEM AND ALL THE MODELS AT LEAST SHOW SOME RAIN
CHANCES WITH THE FRONT WITH THE ECMWF HAVING THE MOST AND FOR NOW
WILL SHOW SOME 30 TO 40 PERCENT CHANCES SUNDAY AND SUNDAY NIGHT.
THE ECMWF PUSHES THE FRONT COMPLETELY THROUGH THE AREA WITH HIGH
PRESSURE BUILDING IN FOR THE START OF NEXT WEEK. HOWEVER...THE GFS
HANGS THE FRONT UP OVER THE AREA AND WOULD SUGGEST THERE WOULD BE
SOME ADDITIONAL RAIN CHANCES MONDAY INTO TUESDAY. WITH THE
UNCERTAINTY ON THAT SECONDARY SHORT WAVE TROUGH...WILL HONOR THE
GFS SOLUTION WITH SOME RAIN CHANCES FOR MONDAY THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1142 PM CDT TUE AUG 11 2015
CONFLICTING SIGNALS FOR FOG FORMATION MAKE FOR A TRICKY FORECAST
AT KLSE. POSITIVE FACTORS INCLUDE A SURFACE RIDGE AXIS ALONG THE
VALLEY FLOOR BY 12.12Z...CALM SURFACE WINDS WITH PERHAPS A WEAK
SOUTHEAST DRAINAGE FLOW...WINDS LESS THAN 10 KTS TO NEAR 5000 FT
AGL...AND CLEAR SKIES. 12.04Z DEW POINT DEPRESSION WAS ALSO 5
DEGREES. NEGATIVE FACTORS INCLUDE A STRONGER NORTHERLY COMPONENT
TO THE WIND ALOFT AS SEEN ON THE RADAR WIND PROFILE...AND A DRY
AIR MASS IMMEDIATELY ABOVE THE SURFACE. ALL SAID...WILL MAINTAIN
PREVIOUS FORECAST WITH LOW TO MEDIUM CONFIDENCE OF OCCURRENCE.
DRY AIR AND SLIGHTLY STRONGER WINDS WILL KEEP FOG FROM FORMING AT
KRST AND REMOVED 5SM IN MIST OVERNIGHT.
AFTER ANY FOG DISSIPATES WEDNESDAY MORNING...EXPECT VFR CONDITIONS
AT BOTH TAF SITES THE REMAINDER OF THE PERIOD WITH MOSTLY SUNNY
SKIES AND LIGHT SOUTH-SOUTHWEST WINDS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...ROGERS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
244 AM MDT WED AUG 12 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
PERSISTENCE. THAT IS THE NAME OF THE GAME THROUGH MOST OF THE SHORT
TERM PERIOD AS HIGH-AMPLITUDE UPPER LEVEL RIDGING REMAINS ANCHORED
OVER THE CENTRAL ROCKIES THROUGH THE END OF THE WORK WEEK. THIS WILL
RESULT IN TYPICAL WYOMING WEATHER FOR MID AUGUST...AS HIGH PRESSURE
CENTERED OVER TX/OK WILL YIELD A PERSISTENT FEED OF MONSOON MOISTURE
STREAMING NORTHWARD INTO THE CWA. CONVECTIVE CHANCES WILL EXIST EACH
AFTERNOON/EVENING...AND MOST AREAS WILL SEE VERY LITTLE VARIATION IN
HIGHS FROM DAY TO DAY. IN THE NEAR TERM...DECIDED TO REMOVE MENTION
OF FOG EARLY THIS AM AS NAM/GFS BUFKIT SOUNDINGS SUGGEST ONLY MODEST
LLVL SATURATION AND THE HRRR KEEPS VISIBILITY HIGH. SCATTERED STORMS
SHOULD DEVELOP ALONG/WEST OF THE LARAMIE RANGE THIS AFTERNOON...AND
BECOME MORE WIDESPREAD AFTER 00Z AS A PRONOUNCED MID LEVEL VORT MAX
TRACKS ACROSS CENTRAL WYO. WOULD EXPECT THIS TIME PERIOD TO BE MORE
ACTIVE THAN THE REST OF THE PERIOD GIVEN COOLER MID LEVEL TEMPS AND
GENERALLY BETTER DYNAMICS. NO SEVERE WEATHER EXPECTED WITH LESS THAN
15 KTS OF H5 FLOW...BUT SLOW MOVING STORMS COULD YIELD SOME CONCERNS
FOR FLASH FLOODING WITH GFS PWATS OVER ONE INCH. THERMAL ENVIRONMENT
WILL BECOME WARMER AND MORE CAPPED LATER IN THE WEEK...SO EXPECT THE
BEST CHANCES FOR CONVECTION TO BE OVER HIGHER TERRAIN ON THU/FRI. H7
TEMPS AVERAGING AROUND +14 TO +16 C FROM ALL MODELS SUGGESTS A WARM
FORECAST PERIOD WITH HIGHS AROUND 90 F OVER MUCH OF THE PLAINS.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL
HIGH...CENTERED NEAR THE FOUR CORNERS REGION...SLOWLY RETROGRADING
AND WEAKENING A BIT BY SUNDAY...AS ENERGY FROM THE NORTHERN
PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES. UNTIL
THEN...EXPECT THE PERSISTENT WEATHER PATTERN TO CONTINUE INTO THE
WEEKEND WITH SOUTHWEST FLOW ALOFT AND DAYTIME CONVECTION DUE TO
THE ADVECTION OF MONSOON MOISTURE FROM THE SOUTHWEST UNITED
STATES. HIGH TEMPERATURES WILL BE ABOVE NORMAL SATURDAY WITH
READINGS IN THE 80S TO MID 90S ACROSS MOST OF THE AREA. PORTIONS
OF WESTERN NEBRASKA AND FAR EASTERN WYOMING MAY REACH THE UPPER
90S ON FRIDAY AS 700MB TEMPERATURES PEAK BETWEEN 15C TO 18C. WITH
PW/S OVER ONE INCH ACROSS THE HIGH PLAINS...THERE WILL BE PLENTY
OF MOISTURE FOR SHOWERS AND TSTORMS TO DEVELOP. HOWEVER...STILL NOT
CONFIDENT ON THE COVERAGE ON SATURDAY DUE TO THE STRENGTH OF THE
UPPER LEVEL HIGH WHICH WILL RESULT IN SUBSTANTIAL MIDLEVEL
SUBSIDENCE...AND MAY SUPPRESS SCATTERED CONVECTION.
HOWEVER...SOME OF THESE TSTORMS MAY CONTAIN VERY HEAVY RAINFALL
WITH ISOLATED FLASH FLOODING POSSIBLE. SEVERE TSTORMS APPEAR
UNLIKELY AT THIS TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
MODELS ARE TRENDING TOWARDS BETTER AGREEMENT AND ARE MORE
CONSISTENT WITH THE OVERALL PATTERN NEXT WEEK. THE GFS HAS TRENDED
TOWARDS THE ECMWF SOLUTION...SHOWING A SERIES OF STRONG COLD
FRONTS FOR THIS TIME OF THE YEAR MOVING ACROSS THE REGION. MODELS
SHOW A STRONG PACIFIC TROUGH MOVING INTO WYOMING ON TUESDAY WITH A
STRONG COLD FRONT MOVING ACROSS THE AREA. IF THE ECMWF SOLUTION
VERIFIES...TEMPERATURES MAY BE AUTUMN-LIKE BY NEXT WEDNESDAY.
COOLER AIR MAY SPREAD INTO THE HIGH PLAINS AS EARLY AS MONDAY WITH
ALL MODELS SHOWING A SHALLOW BACK-DOOR COLD FRONT MOVING SOUTHWEST
ACROSS THE HIGH PLAINS. LOWERED HIGH TEMPERATURES INTO THE 80S
ALONG AND EAST OF THE I25 CORRIDOR. THE MAIN COLD FRONT IS
FORECAST TO PUSH ACROSS THE AREA SOMETIME ON WEDNESDAY...WITH
TEMPERATURES POTENTIALLY LOWERING BELOW NORMAL. MODELS ARE
RELATIVELY DRY WITH THIS FRONTAL PASSAGE...BUT GIVEN THE DYNAMICS
AND RELATIVELY HIGH PW/S ACROSS THE PLAINS...BELIEVE THERE WILL BE
SOME SHOWER/TSTORM ACTIVITY AHEAD AND BEHIND THE FRONT. KEPT POP
AROUND 20 PERCENT FOR NOW...BUT LOWERED TEMPERATURES INTO THE 70S
ACROSS MOST OF SOUTHEAST WYOMING AND NORTHERN NEBRASKA.
KEEP IN MIND THESE FORECAST TEMPERATURES ARE STILL 10 TO 15
DEGREES WARMER THAN WHAT THE ECMWF INDICATES TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH WEDNESDAY NIGHT)
ISSUED AT 217 AM MDT WED AUG 12 2015
LOW CONFIDENCE IN FOG DEVELOPMENT OVER THE SOUTHERN NEBRASKA
PANHANDLE THIS MORNING SINCE WINDS HAVE STARTED TO SHIFT INTO THE
SOUTH AND SOUTHWEST...WITH DEWPOINTS HOVERING AROUND 5 TO 10
DEGREES BELOW THE AIR TEMPERATURE. INCREASED VIS AND REMOVED
OVERCAST CONDITIONS OVER A FEW TERMINALS...BUT CAN NOT RULE OUT
SOME LOW CIGS AND LIGHT MIST NEAR KSNY AND KBFF BETWEEN 10Z TO
15Z THIS MORNING. OTHERWISE ANOTHER ROUND OF SHOWERS AND TSTORMS
ARE EXPECTED OVER SOUTHEAST WYOMING THIS AFTERNOON...AND GRADUALLY
OVER WESTERN NEBRASKA BY THIS EVENING. BRIEF IFR VIS ARE POSSIBLE
IN THE HEAVIER SHOWERS.
&&
.FIRE WEATHER...
ISSUED AT 217 AM MDT WED AUG 12 2015
NO MAJOR FIRE WEATHER CONCERNS THROUGH FRIDAY WITH WIND GUSTS LIKELY
TO REMAIN BELOW 25 MPH AND AFTN HUMIDITIES ABOVE 20-25 PCT. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS SHOULD OCCUR EACH DAY GIVEN A
TYPICAL MONSOON PATTERN IN PLACE. BEST CHANCE FOR WETTING RAINS WILL
BE LATE THIS AFTERNOON AND OVERNIGHT. AS USUAL...EXPECT GUSTY AND/OR
ERRATIC WINDS NEAR THUNDERSTORMS IN ADDITION TO FREQUENT CLOUD-TO-
GROUND LIGHTNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
625 AM EDT WED AUG 12 2015
.SYNOPSIS...
HIGH PRESSURE CENTERED IN THE MIDWEST TODAY WILL EXTEND EASTWARD
AND INTO THE DELMARVA REGION THURSDAY. A FRONTAL SYSTEM WILL BE
NEAR THE SOUTHEAST COAST. ASSOCIATED FRONTAL MOISTURE WILL REMAIN
MAINLY EAST OF THE FORECAST AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
THE FRONT WILL BE STALLED NEAR THE EAST PART OF THE FORECAST AREA
TODAY. HEATING AND CONVERGENCE ASSOCIATED WITH THIS FEATURE MAY
SUPPORT THUNDERSTORMS BUT THE CHANCE APPEARS LOW. THE MODELS
INDICATE JUST WEAK CONVERGENCE. THE WATER VAPOR IMAGERY SHOWS DRY
AIR HAS OVERSPREAD THE AREA. THE GFS AND NAM FORECAST SOUNDINGS
INDICATE MID-LEVEL CAPPING. THE HRRR AND SPC WRF DISPLAYED
JUST ISOLATED SHOWERS OR THUNDERSTORMS. ANY THUNDERSTORMS SHOULD
DISSIPATE THIS EVENING WITH THE LOSS OF HEATING. THE TEMPERATURE
GUIDANCE WAS CLOSE TODAY AND TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
HIGH PRESSURE RIDGING EASTWARD TOWARD THE DELMARVA REGION WILL
CONTINUE TO DIRECT DRY AIR INTO THE FORECAST AREA. WE KEPT THE
FORECAST DRY. THE TEMPERATURE GUIDANCE WAS CONSISTENT.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE MEDIUM-RANGE GUIDANCE CONTINUES TO SHOW AN UPPER TROUGH
ACROSS THE EASTERN PART OF THE NATION. THE REMNANTS OF THE
FRONTAL SYSTEM WILL LINGER NEAR THE FORECAST AREA PLUS A MOISTURE
INCREASE SHOULD OCCUR WITH TIME ASSOCIATED WITH AN ONSHORE FLOW.
THE GFS AND ECMWF MOS HAVE POPS 10 TO 20 PERCENT EARLY INCREASING
TO 30 TO 50 PERCENT LATE IN THE PERIOD. THE MOS HAS TEMPERATURES
NEAR CLIMATOLOGY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE THROUGH THE AREA THIS MORNING. PRECIPITATION
HAS ENDED. SOME MVFR CIGS AT AGS...AND LIFR CIGS AT OGB EARLY THIS
MORNING...CONTINUING UNTIL AROUND 14Z...GENERALLY VFR ELSEWHERE. AS
DRIER AIR MOVES IN BEHIND THE FRONT...EXPECT VFR CONDITIONS ACROSS
THE AREA BY 15Z...WHICH WILL PERSIST THROUGH THE END OF THE TAF
PERIOD. WINDS SHIFTING TO THE NORTHEAST BEHIND THE FRONT.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT RESTRICTIONS TO
AVIATION ARE EXPECTED AT THIS TIME.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1002 AM EDT WED AUG 12 2015
.UPDATE...
ISSUED AT 952 AM EDT WED AUG 12 2015
HIGH PRESSURE TO THE WEST IS MOVING SOUTH FROM THE UPPER GREAT
LAKES, TO THE LOWER OHIO VALLEY. THIS HAS BEEN MIXING OUT AND
PUSHING WHAT STRATOCU WE HAVE HAD LEFT OVER, FROM THE OVERNIGHT.
UPSTREAM, THE RETURN FLOW ON THE NORTH SIDE OF THE HIGH IS
BEGINNING TO PRODUCE RAIN SHOWERS AND SOME THUNDERSTORMS NEAR
THUNDER BAY, ONTARIO THIS MORNING. HOWEVER, AS IT MOVED OUT OVER
LAKE SUPERIOR, IT HAS DIED, AND LOOKS LIKE THE CLOUD COVER IS
BEGINNING TO MIX OUT HAS IT MOVES TO THE SSE. SO THE AFTERNOON, IT
LOOKS LIKE WE SHOULD REMAIN DRY, BUT WILL EXPECT THAT THE RAIN
WILL GET GOING BETTER BY EVENING AS THE RETURN FLOW AND A 500 MB
SHORTWAVE TROUGH MOVE INTO THE UPPER GREAT LAKES OVERNIGHT. THIS
WILL HELP TO KICK OFF SOME THUNDER ACTIVITY.
&&
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL...A CHANCE OF THUNDERSTORMS TONIGHT.
HIGH PRESSURE EXTENDS FROM EASTERN KS TO NW WI. JUST IN ADVANCE OF
THE HIGH...PATCHY STRATOCU REMAINS FRUSTRATINGLY STUBBORN OVER A
PORTION OF NORTHERN MI...THOUGH THE LOW CLOUDS ARE SLOWLY ERODING
WITH TIME. THE HIGH WILL DRIFT SE TOWARD THE OHIO VALLEY THRU
TONIGHT. SHOWERS ARE OCCURRING IN THE WARM/MOIST ADVECTION ZONE ON
THE NORTH FLANK OF THE HIGH...JUST NORTH OF MN. WE WILL ENTER THAT
REGION VERY LATE TODAY INTO TONIGHT...WITH A WARM FRONT ADVANCING
INTO NORTHERN MI LATE TONIGHT. MOST OF TODAY WILL BE QUIET...BUT
CHANCES FOR PRECIP WILL BE INCREASING AS WE MOVE INTO TONIGHT.
TODAY...ONGOING CLOUD COVER WILL ERODE THIS MORNING...THANKS TO
HEATING/MIXING...AND THE ARRIVAL OF A NARROW AXIS OF SOMEWHAT DRIER
AIR NOW OVER WI AND CENTRAL UPPER MI. THAT WILL BE FOLLOWED BY
THE ARRIVAL OF SOME BUBBLY ALTOCU...THE WARM-ADVECTION CLOUD COVER
NOW NORTH OF MN. THE NAM IS CONSIDERABLY FURTHER EAST WITH THE
WARM FRONT LATE TODAY...REACHING A CMX-GRB LINE. THIS RESULTS IN
THE NAM ALLOWING CONVECTION TO REACH NW LOWER MI LATE IN THE
AFTERNOON. GIVEN THE NNW FLOW ALOFT...UPSTREAM RADAR/CLOUD
TRENDS...AND THE BULK OF THE OTHER SHORT-TERM GUIDANCE...THIS
LOOKS TOO FAST. SOMETHING CLOSER TO THE RAP IS PREFERRED...KEEPING
THE WARM FRONT IN CENTRAL WI AND -SHRA IN EASTERN WI/WESTERN UPPER
MI. SOME ACCAS WILL EXPAND IN NW LOWER MI LATE IN THE DAY...BUT
WILL KEEP THE FORECAST DRY THRU 8 PM.
HIGHS WILL BE IN THE 70S.
TONIGHT...WARM FRONT WILL MOVE EAST TOWARD A MUNISING-HTL LINE BY
DAWN. AN AREA OF SHRA EAST OF THE FRONT...STARTING THE EVENING OVER
NE WI/NORTHERN LAKE MI/CENTRAL UPPER WILL MOVE SE...ASSOCIATED WITH
A WEAK BUT FAST-MOVING SHORTWAVE DIVING ACROSS MI. THIS WILL POSE A
RISK FOR PRECIP ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA...
MAINLY DURING THE EVENING (WILL MAINTAIN A RISK OF PRECIP OVERNIGHT
SOUTH OF M-72). NAM LOVES IT/S LOW LEVEL MOISTURE AND GOES
BONKERS WITH MUCAPE. BUT EVEN A MORE REALISTIC MOISTURE PORTRAYAL
GIVES US HIGH THREE-FIGURES OF CAPE...SO WILL ADD THUNDER. WILL
STILL JUST KEEP POPS IN THE CHANCE CATEGORY. A BIT OF SHORTWAVE
RIDGING ARRIVES OVERNIGHT FROM THE NW...PROVIDING A LULL. ANOTHER
BATCH OF PRECIP MAY TRY TO GET GOING BACK BEHIND THAT RIDGE OVER
WESTERN LAKE SUPERIOR AND ENVIRONS. ANY SUCH ACTIVITY LOOKS
UNLIKELY TO REACH THIS FORECAST AREA BY MORNING.
MIN TEMPS WILL BE MILD...ESPECIALLY IN NW LOWER...WHERE A WARMER/
STICKIER AIRMASS WORKS IN BEHIND THE WARM FRONT. LOWS WILL BE
IN THE MID 50S TO MID 60S.
&&
.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL: STILL MONITORING THUNDERSTORM AND
LOCALLY HEAVY RAIN POTENTIAL TO END THE WORK WEEK.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: ONE RATHER MERIDIONAL FLOW
REGIME ACROSS THE CONUS...CONSISTING OF WESTERN/HIGH PLAINS RIDGE
AND EASTERN TROUGH...EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THIS WORK WEEK. NORTHERN MICHIGAN WILL REMAIN SQUARELY UNDER THE
INFLUENCE OF THE LATTER...WITH REINFORCING WAVES AND THEIR ATTENDANT
FRONTAL FEATURES BRINGING SOME SHOWER AND THUNDERSTORM THREAT
THURSDAY INTO FRIDAY. EXCELLENT INTER/INTRA MODEL AGREEMENT FOR A
RATHER SUBSTANTIAL PATTERN SHIFT HEADING INTO THE WEEKEND AND THE
START OF NEXT WEEK...WITH NORTHERN EXTENT OF UPSTREAM RIDGING
FOLDING OVER AND ACROSS THE NORTHERN LAKES...EVENTUALLY SETTING UP A
MUCH MORE ZONAL FLAVOR TO THE FLOW PATTERN ACROSS THE NORTHERN CONUS.
PRIMARY FORECAST CONCERNS/CHALLENGES: EVOLUTION OF SHOWER AND
THUNDERSTORM CHANCES THURSDAY THROUGH FRIDAY.
DETAILS: A CHALLENGING FORECAST SETTING UP FOR THURSDAY AS SOUTHWARD
RETREAT OF WHAT WAS ONCE OVERHEAD SURFACE HIGH PRESSURE
CONTINUES...ALLOWING A WEAK WARM FRONT TO SWEEP ACROSS THE AREA.
FRONT ITSELF DOES NOT LOOK ALL THAT ACTIVE...WITH LITTLE DEEP LAYER
SUPPORT. INCREASINGLY WARM/HUMID AIRMASS AND PASSING OF SUBTLE MID
LEVEL WAVE MAY ALLOW A FEW AFTERNOON SHOWERS AND STORMS TO
FIRE...ALTHOUGH STILL BELIEVE BETTER ACTIVITY WILL WAIT UNTIL THE
OVERNIGHT HOURS WHEN SOUTHEAST DROPPING CANADIAN COLD FRONT BEGINS
TO ENTER THE PICTURE. WHILE OVERNIGHT TIMING SHOULD HELP TO PREVENT
MUCH OF A SEVERE WEATHER THREAT...0-6KM BULK SHEAR OF UP TO 30 KNOTS
DOES SUPPORT AT LEAST SOME STORM ORGANIZATION.
COLD FRONT EXPECTED TO ONLY MAKE SLOW PROGRESS SOUTH ACROSS THE AREA
FRIDAY AS PARENT LOW PRESSURE IS WELL REMOVED TO THE NORTH. PER THE
USUAL...DAYTIME HEATING WILL ONLY FURTHER HINDER THE FRONTAL
ADVANCEMENT...ALTHOUGH SUSPECT SPEED TO BE AT LEAST PARTIALLY
DICTATED BY ANY SHOWER AND STORM PRODUCED OUTFLOWS. STILL LIKE THE
IDEA OF KEEPING THE BETTER CHANCES FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS SOUTH OF THE BRIDGE...PARTICULARLY SOUTH OF M-32. WHILE
NOT EXTREME...PRECIPITABLE WATERS AROUND AN INCH AND A HALF AND
POSSIBILITY FOR AT LEAST A COUPLE ROUNDS OF STORMS DEFINITELY
SUPPORTS SOME LOCALLY HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL IN OUR LATEST HAZARDOUS WEATHER PRODUCTS.
&&
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 306 AM EDT WED AUG 12 2015
AS MENTIONED EARLIER...SOME RATHER SIGNIFICANT CHANGES TO THE
LONG WAVE PATTERN SET TO TAKE SHAPE TO START THE WEEKEND. STRONG
ENERGY PUNCHING INTO THE CANADA WEST COAST AND EASTWARD PUNT OF
CURRENT WEST COAST CUTOFF LOW HELP SET THESE CHANGES IN
MOTION...WORKING IN TANDEM TO FORCE NORTHERN EXTENT OF SUBTROPICAL
RIDGE TO FOLD OVER INTO THE NORTHERN LAKES. PATTERN SET TO BECOME
TEMPORARILY MORE ZONAL INTO THE START OF NEXT WEEK AS NORTHERN
EXTENT OF RIDGING IS SHUNTED OFF THE EAST COAST. THE WEEKEND
CONTINUES TO LOOK DRY AND RATHER WARM...WITH TEMPERATURES AT LEAST
SEVERAL DEGREES ABOVE NORMAL. NOT OUT OF THE REALM OF POSSIBILITY
A FEW OF THE TRADITIONAL WARMER LOCALES MAKE A RUN AT 90 DEGREES
BY SUNDAY. NEXT STRETCH OF ACTIVE WEATHER (AT LEAST POTENTIALLY)
ARRIVES SUNDAY NIGHT THROUGH TUESDAY AS WARM/MOIST AIRMASS IS
WORKED OVER BY APPROACHING WAVES AND HINTS OF A SLOW MOVING COLD
FRONT. OF COURSE...PLENTY OF TIME FOR THIS TO ALL CHANGE...SO
INHERITED CHANCY POPS MORE THAN FINE FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 642 AM EDT WED AUG 12 2015
VFR.
LEFTOVER STRATOCU OVER FAR NORTHERN LOWER CONTINUES TO
SHRIVEL...AND IS PRESENTLY A VFR DECK REGARDLESS. A WARM FRONT
WILL ADVANCE EAST INTO WI TODAY...AND LOWER MI TONIGHT.
SHRA/PERHAPS TSRA AHEAD OF THIS FRONT WILL EXPAND INTO NW LOWER
MI WEDNESDAY EVENING...POTENTIALLY IMPACTING TVC/MBL. GENERALLY
EXPECT CIGS/VSBYS TO REMAIN VFR.
A BIT OF A NW BREEZE TODAY...NOT AS GUSTY AS TUESDAY.
&&
.MARINE...
ISSUED AT 306 AM EDT WED AUG 12 2015
NW WINDS WILL CONTINUE TODAY...THOUGH WEAKER/LESS GUSTY THAN
TUESDAY. A WARM FRONT WILL MOVE EAST INTO NORTHERN MI
TONIGHT...PERHAPS BRINGING SHOWERS/STORMS TO NORTHERN LAKE MI.
SOUTHWEST WINDS WILL SEEN ON THURSDAY BEHIND THE WARM
FRONT...THOUGH AGAIN THESE WILL NOT BE PARTICULARLY STRONG. SMALL
CRAFT ADVISORIES ARE NOT EXPECTED TO BE NEEDED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JSL
NEAR TERM...JAZ
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JAZ
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
642 AM EDT WED AUG 12 2015
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL...A CHANCE OF THUNDERSTORMS TONIGHT.
HIGH PRESSURE EXTENDS FROM EASTERN KS TO NW WI. JUST IN ADVANCE OF
THE HIGH...PATCHY STRATOCU REMAINS FRUSTRATINGLY STUBBORN OVER A
PORTION OF NORTHERN MI...THOUGH THE LOW CLOUDS ARE SLOWLY ERODING
WITH TIME. THE HIGH WILL DRIFT SE TOWARD THE OHIO VALLEY THRU
TONIGHT. SHOWERS ARE OCCURRING IN THE WARM/MOIST ADVECTION ZONE ON
THE NORTH FLANK OF THE HIGH...JUST NORTH OF MN. WE WILL ENTER THAT
REGION VERY LATE TODAY INTO TONIGHT...WITH A WARM FRONT ADVANCING
INTO NORTHERN MI LATE TONIGHT. MOST OF TODAY WILL BE QUIET...BUT
CHANCES FOR PRECIP WILL BE INCREASING AS WE MOVE INTO TONIGHT.
TODAY...ONGOING CLOUD COVER WILL ERODE THIS MORNING...THANKS TO
HEATING/MIXING...AND THE ARRIVAL OF A NARROW AXIS OF SOMEWHAT DRIER
AIR NOW OVER WI AND CENTRAL UPPER MI. THAT WILL BE FOLLOWED BY
THE ARRIVAL OF SOME BUBBLY ALTOCU...THE WARM-ADVECTION CLOUD COVER
NOW NORTH OF MN. THE NAM IS CONSIDERABLY FURTHER EAST WITH THE
WARM FRONT LATE TODAY...REACHING A CMX-GRB LINE. THIS RESULTS IN
THE NAM ALLOWING CONVECTION TO REACH NW LOWER MI LATE IN THE
AFTERNOON. GIVEN THE NNW FLOW ALOFT...UPSTREAM RADAR/CLOUD
TRENDS...AND THE BULK OF THE OTHER SHORT-TERM GUIDANCE...THIS
LOOKS TOO FAST. SOMETHING CLOSER TO THE RAP IS PREFERRED...KEEPING
THE WARM FRONT IN CENTRAL WI AND -SHRA IN EASTERN WI/WESTERN UPPER
MI. SOME ACCAS WILL EXPAND IN NW LOWER MI LATE IN THE DAY...BUT
WILL KEEP THE FORECAST DRY THRU 8 PM.
HIGHS WILL BE IN THE 70S.
TONIGHT...WARM FRONT WILL MOVE EAST TOWARD A MUNISING-HTL LINE BY
DAWN. AN AREA OF SHRA EAST OF THE FRONT...STARTING THE EVENING OVER
NE WI/NORTHERN LAKE MI/CENTRAL UPPER WILL MOVE SE...ASSOCIATED WITH
A WEAK BUT FAST-MOVING SHORTWAVE DIVING ACROSS MI. THIS WILL POSE A
RISK FOR PRECIP ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA...
MAINLY DURING THE EVENING (WILL MAINTAIN A RISK OF PRECIP OVERNIGHT
SOUTH OF M-72). NAM LOVES IT/S LOW LEVEL MOISTURE AND GOES
BONKERS WITH MUCAPE. BUT EVEN A MORE REALISTIC MOISTURE PORTRAYAL
GIVES US HIGH THREE-FIGURES OF CAPE...SO WILL ADD THUNDER. WILL
STILL JUST KEEP POPS IN THE CHANCE CATEGORY. A BIT OF SHORTWAVE
RIDGING ARRIVES OVERNIGHT FROM THE NW...PROVIDING A LULL. ANOTHER
BATCH OF PRECIP MAY TRY TO GET GOING BACK BEHIND THAT RIDGE OVER
WESTERN LAKE SUPERIOR AND ENVIRONS. ANY SUCH ACTIVITY LOOKS
UNLIKELY TO REACH THIS FORECAST AREA BY MORNING.
MIN TEMPS WILL BE MILD...ESPECIALLY IN NW LOWER...WHERE A WARMER/
STICKIER AIRMASS WORKS IN BEHIND THE WARM FRONT. LOWS WILL BE
IN THE MID 50S TO MID 60S.
&&
.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL: STILL MONITORING THUNDERSTORM AND
LOCALLY HEAVY RAIN POTENTIAL TO END THE WORK WEEK.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: ONE RATHER MERIDIONAL FLOW
REGIME ACROSS THE CONUS...CONSISTING OF WESTERN/HIGH PLAINS RIDGE
AND EASTERN TROUGH...EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THIS WORK WEEK. NORTHERN MICHIGAN WILL REMAIN SQUARELY UNDER THE
INFLUENCE OF THE LATTER...WITH REINFORCING WAVES AND THEIR ATTENDANT
FRONTAL FEATURES BRINGING SOME SHOWER AND THUNDERSTORM THREAT
THURSDAY INTO FRIDAY. EXCELLENT INTER/INTRA MODEL AGREEMENT FOR A
RATHER SUBSTANTIAL PATTERN SHIFT HEADING INTO THE WEEKEND AND THE
START OF NEXT WEEK...WITH NORTHERN EXTENT OF UPSTREAM RIDGING
FOLDING OVER AND ACROSS THE NORTHERN LAKES...EVENTUALLY SETTING UP A
MUCH MORE ZONAL FLAVOR TO THE FLOW PATTERN ACROSS THE NORTHERN CONUS.
PRIMARY FORECAST CONCERNS/CHALLENGES: EVOLUTION OF SHOWER AND
THUNDERSTORM CHANCES THURSDAY THROUGH FRIDAY.
DETAILS: A CHALLENGING FORECAST SETTING UP FOR THURSDAY AS SOUTHWARD
RETREAT OF WHAT WAS ONCE OVERHEAD SURFACE HIGH PRESSURE
CONTINUES...ALLOWING A WEAK WARM FRONT TO SWEEP ACROSS THE AREA.
FRONT ITSELF DOES NOT LOOK ALL THAT ACTIVE...WITH LITTLE DEEP LAYER
SUPPORT. INCREASINGLY WARM/HUMID AIRMASS AND PASSING OF SUBTLE MID
LEVEL WAVE MAY ALLOW A FEW AFTERNOON SHOWERS AND STORMS TO
FIRE...ALTHOUGH STILL BELIEVE BETTER ACTIVITY WILL WAIT UNTIL THE
OVERNIGHT HOURS WHEN SOUTHEAST DROPPING CANADIAN COLD FRONT BEGINS
TO ENTER THE PICTURE. WHILE OVERNIGHT TIMING SHOULD HELP TO PREVENT
MUCH OF A SEVERE WEATHER THREAT...0-6KM BULK SHEAR OF UP TO 30 KNOTS
DOES SUPPORT AT LEAST SOME STORM ORGANIZATION.
COLD FRONT EXPECTED TO ONLY MAKE SLOW PROGRESS SOUTH ACROSS THE AREA
FRIDAY AS PARENT LOW PRESSURE IS WELL REMOVED TO THE NORTH. PER THE
USUAL...DAYTIME HEATING WILL ONLY FURTHER HINDER THE FRONTAL
ADVANCEMENT...ALTHOUGH SUSPECT SPEED TO BE AT LEAST PARTIALLY
DICTATED BY ANY SHOWER AND STORM PRODUCED OUTFLOWS. STILL LIKE THE
IDEA OF KEEPING THE BETTER CHANCES FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS SOUTH OF THE BRIDGE...PARTICULARLY SOUTH OF M-32. WHILE
NOT EXTREME...PRECIPITABLE WATERS AROUND AN INCH AND A HALF AND
POSSIBILITY FOR AT LEAST A COUPLE ROUNDS OF STORMS DEFINITELY
SUPPORTS SOME LOCALLY HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL IN OUR LATEST HAZARDOUS WEATHER PRODUCTS.
&&
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 306 AM EDT WED AUG 12 2015
AS MENTIONED EARLIER...SOME RATHER SIGNIFICANT CHANGES TO THE
LONG WAVE PATTERN SET TO TAKE SHAPE TO START THE WEEKEND. STRONG
ENERGY PUNCHING INTO THE CANADA WEST COAST AND EASTWARD PUNT OF
CURRENT WEST COAST CUTOFF LOW HELP SET THESE CHANGES IN
MOTION...WORKING IN TANDEM TO FORCE NORTHERN EXTENT OF SUBTROPICAL
RIDGE TO FOLD OVER INTO THE NORTHERN LAKES. PATTERN SET TO BECOME
TEMPORARILY MORE ZONAL INTO THE START OF NEXT WEEK AS NORTHERN
EXTENT OF RIDGING IS SHUNTED OFF THE EAST COAST. THE WEEKEND
CONTINUES TO LOOK DRY AND RATHER WARM...WITH TEMPERATURES AT LEAST
SEVERAL DEGREES ABOVE NORMAL. NOT OUT OF THE REALM OF POSSIBILITY
A FEW OF THE TRADITIONAL WARMER LOCALES MAKE A RUN AT 90 DEGREES
BY SUNDAY. NEXT STRETCH OF ACTIVE WEATHER (AT LEAST POTENTIALLY)
ARRIVES SUNDAY NIGHT THROUGH TUESDAY AS WARM/MOIST AIRMASS IS
WORKED OVER BY APPROACHING WAVES AND HINTS OF A SLOW MOVING COLD
FRONT. OF COURSE...PLENTY OF TIME FOR THIS TO ALL CHANGE...SO
INHERITED CHANCY POPS MORE THAN FINE FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 642 AM EDT WED AUG 12 2015
VFR.
LEFTOVER STRATOCU OVER FAR NORTHERN LOWER CONTINUES TO
SHRIVEL...AND IS PRESENTLY A VFR DECK REGARDLESS. A WARM FRONT
WILL ADVANCE EAST INTO WI TODAY...AND LOWER MI TONIGHT.
SHRA/PERHAPS TSRA AHEAD OF THIS FRONT WILL EXPAND INTO NW LOWER
MI WEDNESDAY EVENING...POTENTIALLY IMPACTING TVC/MBL. GENERALLY
EXPECT CIGS/VSBYS TO REMAIN VFR.
A BIT OF A NW BREEZE TODAY...NOT AS GUSTY AS TUESDAY.
&&
.MARINE...
ISSUED AT 306 AM EDT WED AUG 12 2015
NW WINDS WILL CONTINUE TODAY...THOUGH WEAKER/LESS GUSTY THAN
TUESDAY. A WARM FRONT WILL MOVE EAST INTO NORTHERN MI
TONIGHT...PERHAPS BRINGING SHOWERS/STORMS TO NORTHERN LAKE MI.
SOUTHWEST WINDS WILL SEEN ON THURSDAY BEHIND THE WARM
FRONT...THOUGH AGAIN THESE WILL NOT BE PARTICULARLY STRONG. SMALL
CRAFT ADVISORIES ARE NOT EXPECTED TO BE NEEDED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
NEAR TERM...JAZ
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JAZ
MARINE...JAZ
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
901 AM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 901 AM CDT WED AUG 12 2015
UPDATED THE FORECAST TO INCREASE THE HIGH TEMPERATURES AND WIND
SPEEDS AND GUSTS FOR TODAY. THE FOCUS FOR INCREASING THE
TEMPERATURES WAS FOR NEAR THE TWIN PORTS. THINK THE SUNNY
SKIES AND WARM AND GUSTY SW WINDS TODAY WILL BE A GOOD RECIPE FOR
WARMING TODAY...SO WANTED TO LEAN ON THE WARMER
GFSMOS/SREFBC/RAP13BC MODEL GUIDANCE. DOWNSLOPE WARMING SHOULD
ALSO ALLOW TEMPERATURES NEAR THE TWIN PORTS SHORELINE...INCLUDING
PARK POINT...TO WARM UP INTO THE UPPER 80S. INCREASED THE PARK
POINT FORECAST FROM THE EARLIER FORECAST OF ABOUT 81 TO NOW 87.
THE RAP13/NAM12 MODEL SOUNDINGS SUGGEST THERE COULD BE GUSTS TO
AROUND 20 MPH OVER MUCH OF THE FORECAST AREA BY LATER THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
SUMMER HEAT RETURNS WITH SOME OF THE WARMEST WEATHER OF THE SUMMER
SO FAR TODAY AND TOMORROW. MORNING SHOWERS AND MAYBE A THUNDERSTORM
ACROSS THE TIP OF THE MINNESOTA ARROWHEAD THIS MORNING...BUT
OTHERWISE MOSTLY SUNNY THIS AFTERNOON WITH A BREEZY SOUTHWEST WIND.
TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST
ACROSS THE AREA WITH THE POSSIBILITY FOR A FEW STORMS TO BECOME
STRONG TO SEVERE. THURSDAY WILL BE THE HOTTEST DAY OF THE FORECAST
WITH HIGHS IN THE UPPER 80S TO LOW 90S AND THE POSSIBILITY FOR
ISOLATED STORMS.
ON THE SYNOPTIC SCALE A FAIRLY TYPICAL SUMMER PATTERN WITH AN UPPER
LEVEL RIDGE AXIS ALONG THE HIGH PLAINS AND A RESULTING NORTHWEST
FLOW ALOFT LOCALLY. THIS MORNING AN ELEVATED WARM FRONT IS MOVING
ACROSS FAR NORTHEAST MINNESOTA AND IT MOVES SOUTHEAST ACROSS SW
ONTARIO AND ACROSS WESTERN LAKE SUPERIOR...RESULTING IN SOME
ISOLATED SHOWERS AND STORMS. THE BROAD AREA OF HIGH PRESSURE OVER
THE AREA YESTERDAY HAS MOVED SOUTH INTO THE MID-MISSISSIPPI TO OHIO
VALLEY...WHICH WILL RESULT IN SOUTHWEST FLOW AT LOW LEVELS AND
CAUSE 850MB TEMPS TO SURGE 4-8 DEG CELSIUS TODAY. THIS WILL ALSO
INCREASE LOW LEVEL MOISTURE RESULTING IN DEW POINTS HEADING INTO THE
LOW TO MID 60S BY TONIGHT. THIS WILL ALL BE AHEAD OF A WEAK
FRONT/TROUGH THAT IS EXPECT TO BE THE FOCUS FOR STORM INITIATION
ACROSS SOUTHERN MANITOBA AND FAR NORTHEAST NORTH DAKOTA LATE TODAY
WITH STORMS MOVING INTO NORTHERN MINNESOTA TONIGHT. WHILE ONLY A
SUBTLY MID-LEVEL SHORTWAVE EXISTS AT 500MB...A 80-100 KT 300MB JET
STREAK ALOFT WILL PROVIDE RESULT IN DIVERGENCE ALOFT ACROSS
NORTHEAST MINNESOTA TONIGHT AND THUS PROVIDE SOME LARGE-SCALE
LIFT...NOT TO MENTION THE FASTER WINDS ALOFT WILL RESULT IN BETTER
DEEP LAYER SHEAR FOR STORMS TO SUSTAIN INTO THE NIGHT. ON THURSDAY
ANOTHER ELEVATED TROUGH/FRONT WILL MOVE THROUGH FROM THE
NORTHWEST...BUT CAP WILL LIKELY LIMIT COVERAGE OF STORMS.
EARLY THIS MORNING...PATCHY FOG WITH SHOWERS ACROSS THE TIP OF THE
ARROWHEAD. RAP SEEMED TO HAVE A GOOD HANDLE ON THE FOG DEVELOPMENT
WITH THE LOWEST VISIBILITIES DEVELOPING ACROSS NORTHEAST
WISCONSIN...WITH FOG EXPECTED TO BURN OFF JUST AFTER SUNRISE. USED
JUST SHOWERS WORDING IN THE FORECAST FOR THE ARROWHEAD GIVEN LACK OF
INSTABILITY EARLY THIS MORNING...BUT ADD IN ISOLATED THUNDER TOWARDS
MID-MORNING. OTHERWISE CLEAR SKIES AND TEMPS FALLING TO THE MID 50S
OR COOLER IN A FEW SPOTS.
THIS AFTERNOON...HOT AND SUNNY. BREEZY...SOUTHWEST WINDS GUSTING TO
20-25 MPH AT TIMES DUE TO DEEP MIXING. HIGHS IN THE LOW 80S OVER
NORTHWEST WISCONSIN AND THE ARROWHEAD...INTO THE MID TO UPPER 80S
ELSEWHERE INCLUDING THE TWIN PORTS. INCREASING CLOUDS ALONG THE
INTERNATIONAL BORDER LATE IN THE DAY.
TONIGHT...ISOLATED TO SCATTERED SHOWERS AND STORMS MOVING FROM
NORTHWEST TO SOUTHEAST ACROSS NORTHEAST MINNESOTA INTO NORTHWEST
WISCONSIN. WITH MUCAPE VALUES 1500-2000 J/KG AND DEEP LAYER SHEAR
AROUND 40-50KTS STRONG TO SEVERE STORMS ARE LIKELY IF STORMS DO
DEVELOP. THESE STORMS ARE EXPECTED TO BE ELEVATED....BUT IT SHOULD
BE NOTED 0-3KM HELICITY OF 300-400 M2/S2 ACROSS NORTH-CENTRAL
MINNESOTA AROUND 00-04 UTC THIS EVENING WHICH WOULD RESULT IN
ROTATING STORMS...BUT THE HIGH LCL HEIGHTS SHOULD PRECLUDE A
TORNADIC RISK. STILL...SOMETHING TO MONITOR. OTHERWISE THE NORMAL
HAIL/WIND/HEAVY RAINFALL THREATS WITH STORMS EXPECTED TO MOVE ACROSS
NORTHEAST MINNESOTA THROUGH MIDNIGHT AND ROLL INTO NORTHWEST
WISCONSIN IN THE EARLY MORNING HOURS. AGREE WITH INITIAL DAY ONE SPC
OUTLOOK WITH A MARGINAL RISK FOR MUCH OF THE NORTHLAND...BUT THIS
MAY NEED TO BE REEVALUATED FOR AN UPGRADE THIS AFTERNOON DEPENDING ON
HOW CONDITIONS EVOLVE.
THURSDAY...SOME UNCERTAINTY AS TO PRECIPITATION BUT NOT WHEN IT
COMES TO THE HEAT AND HUMIDITY...IT IS GOING TO BE A HOT ONE OUT
THERE. MOST GUIDANCE DEPICTING ANOTHER TROUGH/FRONT MOVING THROUGH
IN THE AFTERNOON...BUT BASED ON MODEL SOUNDINGS THINK CAP MIGHT BE
STRONG ENOUGH TO PREVENT WIDESPREAD STORMS. IF STORMS DO
DEVELOP...EXPECT RAPID DEVELOPMENT DUE TO MUCAPE IN EXCESS OF 2000
J/KG AND WITH 0-6KM SHEAR IN THE 25 TO 35 KT RANGE COULD SEE STORMS
SUSTAIN FOR A FEW HOURS. HIGHS IN THE MID 80S ACROSS NORTHWEST
WISCONSIN...IN THE UPPER 80S TO LOW 90S ACROSS NORTHEAST MINNESOTA
EXCEPT FOR THE TIP OF THE ARROWHEAD.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
A COLD FRONT WILL CONTINUE SOUTH THROUGH THE NORTHLAND THURSDAY
NIGHT WITH HIGH PRESSURE BUILDING IN DURING THE DAY FRIDAY. WE
LINGER CHANCES FOR SHOWERS/STORMS THURSDAY NIGHT OVER THE EASTERN
TWO THIRDS OF THE CWA THEN WENT DRY FOR MOST AREAS ON FRIDAY UNDER
THE HIGH. HIGHS FRIDAY WILL BE IN THE MIDDLE 80S.
THE HIGH WILL MOVE OFF TO THE EAST SATURDAY WITH ANOTHER COLD FRONT
OVER THE NORTHERN PLAINS PROGRESSING EAST. IT SHOULD BE VERY WARM
AND DRY SATURDAY WITH HIGHS IN THE 80S.
THE FRONT WILL CONTINUE EAST SATURDAY NIGHT INTO SUNDAY. THERE ARE
SOME TIMING DIFFERENCES BETWEEN THE GFS/ECMWF...WITH THE GFS FASTER.
THERE WILL BE A CHANCE FOR SHOWERS/STORMS SATURDAY NIGHT/SUNDAY WITH
THIS FRONT. AT THIS POINT...THE INSTABILITY IS NOT REAL IMPRESSIVE.
HOWEVER...THERE WILL BE A GOOD SOUTH/SOUTHWEST FLOW AHEAD OF THE
FRONT AS SEEN WITH 850MB WINDS 40-50KT AND GOOD LOW LEVEL
CONVERGENCE WITH THE FRONT. SOME STRONG STORMS WILL BE POSSIBLE.
THE MODELS DIVERGE MONDAY INTO MID WEEK WITH SOME FAIRLY LARGE
DIFFERENCES. AT THIS POINT WE HAVE LOW POPS THROUGH THAT PERIOD.
HIGHS MONDAY/TUESDAY WILL BE COOLER WITH HIGHS IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 635 AM CDT WED AUG 12 2015
MOST AREAS WERE UNDER VFR CONDITIONS EARLY THIS
MORNING...ALTHOUGH THERE HAS BEEN SOME PATCHY FOG. AN AREA OF WAA
HAS CAUSED SHOWERS AND A FEW THUNDERSTORMS TO MOVE THROUGH THE
ARROWHEAD...BUT THOSE WILL BE SHIFTING EAST EARLY TODAY.
ANOTHER AREA OF SHOWERS/STORMS WERE MOVING THROUGH MANITOBA AND
WILL TURN SOUTHEAST AS THEY CREST THE UPPER RIDGE. TIMING THIS
ACTIVITY IS A CHALLENGE AND WE RELIED ON AN ENSEMBLE APPROACH
INCLUDING USING THE CAMS. WE INTRODUCE VCSH TO KINL AROUND 22Z AND
HAVE A MENTION OF THUNDERSTORMS THERE INTO THE EVENING. THE CHANCE
FOR SHOWERS/STORMS WILL PROGRESS SOUTHEAST TONIGHT DUE TO A TROUGH
OF LOW PRESSURE AND CONTINUED WAA. INSTABILITY WILL BE INCREASING
AS WELL...SO SOME STRONG TO POSSIBLY SEVERE STORMS MAY OCCUR.
TIMING OF THE SHOWERS/STORMS WILL LIKELY NEED TO BE ADJUSTED AS
WE PROGRESS THROUGH THE DAY.
THE GRADIENT WILL TIGHTEN TODAY AND WITH GOOD MIXING...WE SHOULD
SEE GUSTY SOUTHERLY WINDS DEVELOP BY LATE MORNING/EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 87 65 90 65 / 10 30 20 30
INL 89 61 88 59 / 40 50 20 10
BRD 86 66 90 65 / 10 20 10 10
HYR 84 63 86 63 / 0 40 30 20
ASX 86 64 88 62 / 10 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...GROCHOCINSKI
SHORT TERM...JJM
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
641 AM CDT WED AUG 12 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
SUMMER HEAT RETURNS WITH SOME OF THE WARMEST WEATHER OF THE SUMMER
SO FAR TODAY AND TOMORROW. MORNING SHOWERS AND MAYBE A THUNDERSTORM
ACROSS THE TIP OF THE MINNESOTA ARROWHEAD THIS MORNING...BUT
OTHERWISE MOSTLY SUNNY THIS AFTERNOON WITH A BREEZY SOUTHWEST WIND.
TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST
ACROSS THE AREA WITH THE POSSIBILITY FOR A FEW STORMS TO BECOME
STRONG TO SEVERE. THURSDAY WILL BE THE HOTTEST DAY OF THE FORECAST
WITH HIGHS IN THE UPPER 80S TO LOW 90S AND THE POSSIBILITY FOR
ISOLATED STORMS.
ON THE SYNOPTIC SCALE A FAIRLY TYPICAL SUMMER PATTERN WITH AN UPPER
LEVEL RIDGE AXIS ALONG THE HIGH PLAINS AND A RESULTING NORTHWEST
FLOW ALOFT LOCALLY. THIS MORNING AN ELEVATED WARM FRONT IS MOVING
ACROSS FAR NORTHEAST MINNESOTA AND IT MOVES SOUTHEAST ACROSS SW
ONTARIO AND ACROSS WESTERN LAKE SUPERIOR...RESULTING IN SOME
ISOLATED SHOWERS AND STORMS. THE BROAD AREA OF HIGH PRESSURE OVER
THE AREA YESTERDAY HAS MOVED SOUTH INTO THE MID-MISSISSIPPI TO OHIO
VALLEY...WHICH WILL RESULT IN SOUTHWEST FLOW AT LOW LEVELS AND
CAUSE 850MB TEMPS TO SURGE 4-8 DEG CELSIUS TODAY. THIS WILL ALSO
INCREASE LOW LEVEL MOISTURE RESULTING IN DEW POINTS HEADING INTO THE
LOW TO MID 60S BY TONIGHT. THIS WILL ALL BE AHEAD OF A WEAK
FRONT/TROUGH THAT IS EXPECT TO BE THE FOCUS FOR STORM INITIATION
ACROSS SOUTHERN MANITOBA AND FAR NORTHEAST NORTH DAKOTA LATE TODAY
WITH STORMS MOVING INTO NORTHERN MINNESOTA TONIGHT. WHILE ONLY A
SUBTLY MID-LEVEL SHORTWAVE EXISTS AT 500MB...A 80-100 KT 300MB JET
STREAK ALOFT WILL PROVIDE RESULT IN DIVERGENCE ALOFT ACROSS
NORTHEAST MINNESOTA TONIGHT AND THUS PROVIDE SOME LARGE-SCALE
LIFT...NOT TO MENTION THE FASTER WINDS ALOFT WILL RESULT IN BETTER
DEEP LAYER SHEAR FOR STORMS TO SUSTAIN INTO THE NIGHT. ON THURSDAY
ANOTHER ELEVATED TROUGH/FRONT WILL MOVE THROUGH FROM THE
NORTHWEST...BUT CAP WILL LIKELY LIMIT COVERAGE OF STORMS.
EARLY THIS MORNING...PATCHY FOG WITH SHOWERS ACROSS THE TIP OF THE
ARROWHEAD. RAP SEEMED TO HAVE A GOOD HANDLE ON THE FOG DEVELOPMENT
WITH THE LOWEST VISIBILITIES DEVELOPING ACROSS NORTHEAST
WISCONSIN...WITH FOG EXPECTED TO BURN OFF JUST AFTER SUNRISE. USED
JUST SHOWERS WORDING IN THE FORECAST FOR THE ARROWHEAD GIVEN LACK OF
INSTABILITY EARLY THIS MORNING...BUT ADD IN ISOLATED THUNDER TOWARDS
MID-MORNING. OTHERWISE CLEAR SKIES AND TEMPS FALLING TO THE MID 50S
OR COOLER IN A FEW SPOTS.
THIS AFTERNOON...HOT AND SUNNY. BREEZY...SOUTHWEST WINDS GUSTING TO
20-25 MPH AT TIMES DUE TO DEEP MIXING. HIGHS IN THE LOW 80S OVER
NORTHWEST WISCONSIN AND THE ARROWHEAD...INTO THE MID TO UPPER 80S
ELSEWHERE INCLUDING THE TWIN PORTS. INCREASING CLOUDS ALONG THE
INTERNATIONAL BORDER LATE IN THE DAY.
TONIGHT...ISOLATED TO SCATTERED SHOWERS AND STORMS MOVING FROM
NORTHWEST TO SOUTHEAST ACROSS NORTHEAST MINNESOTA INTO NORTHWEST
WISCONSIN. WITH MUCAPE VALUES 1500-2000 J/KG AND DEEP LAYER SHEAR
AROUND 40-50KTS STRONG TO SEVERE STORMS ARE LIKELY IF STORMS DO
DEVELOP. THESE STORMS ARE EXPECTED TO BE ELEVATED....BUT IT SHOULD
BE NOTED 0-3KM HELICITY OF 300-400 M2/S2 ACROSS NORTH-CENTRAL
MINNESOTA AROUND 00-04 UTC THIS EVENING WHICH WOULD RESULT IN
ROTATING STORMS...BUT THE HIGH LCL HEIGHTS SHOULD PRECLUDE A
TORNADIC RISK. STILL...SOMETHING TO MONITOR. OTHERWISE THE NORMAL
HAIL/WIND/HEAVY RAINFALL THREATS WITH STORMS EXPECTED TO MOVE ACROSS
NORTHEAST MINNESOTA THROUGH MIDNIGHT AND ROLL INTO NORTHWEST
WISCONSIN IN THE EARLY MORNING HOURS. AGREE WITH INITIAL DAY ONE SPC
OUTLOOK WITH A MARGINAL RISK FOR MUCH OF THE NORTHLAND...BUT THIS
MAY NEED TO BE REEVALUATED FOR AN UPGRADE THIS AFTERNOON DEPENDING ON
HOW CONDITIONS EVOLVE.
THURSDAY...SOME UNCERTAINTY AS TO PRECIPITATION BUT NOT WHEN IT
COMES TO THE HEAT AND HUMIDITY...IT IS GOING TO BE A HOT ONE OUT
THERE. MOST GUIDANCE DEPICTING ANOTHER TROUGH/FRONT MOVING THROUGH
IN THE AFTERNOON...BUT BASED ON MODEL SOUNDINGS THINK CAP MIGHT BE
STRONG ENOUGH TO PREVENT WIDESPREAD STORMS. IF STORMS DO
DEVELOP...EXPECT RAPID DEVELOPMENT DUE TO MUCAPE IN EXCESS OF 2000
J/KG AND WITH 0-6KM SHEAR IN THE 25 TO 35 KT RANGE COULD SEE STORMS
SUSTAIN FOR A FEW HOURS. HIGHS IN THE MID 80S ACROSS NORTHWEST
WISCONSIN...IN THE UPPER 80S TO LOW 90S ACROSS NORTHEAST MINNESOTA
EXCEPT FOR THE TIP OF THE ARROWHEAD.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
A COLD FRONT WILL CONTINUE SOUTH THROUGH THE NORTHLAND THURSDAY
NIGHT WITH HIGH PRESSURE BUILDING IN DURING THE DAY FRIDAY. WE
LINGER CHANCES FOR SHOWERS/STORMS THURSDAY NIGHT OVER THE EASTERN
TWO THIRDS OF THE CWA THEN WENT DRY FOR MOST AREAS ON FRIDAY UNDER
THE HIGH. HIGHS FRIDAY WILL BE IN THE MIDDLE 80S.
THE HIGH WILL MOVE OFF TO THE EAST SATURDAY WITH ANOTHER COLD FRONT
OVER THE NORTHERN PLAINS PROGRESSING EAST. IT SHOULD BE VERY WARM
AND DRY SATURDAY WITH HIGHS IN THE 80S.
THE FRONT WILL CONTINUE EAST SATURDAY NIGHT INTO SUNDAY. THERE ARE
SOME TIMING DIFFERENCES BETWEEN THE GFS/ECMWF...WITH THE GFS FASTER.
THERE WILL BE A CHANCE FOR SHOWERS/STORMS SATURDAY NIGHT/SUNDAY WITH
THIS FRONT. AT THIS POINT...THE INSTABILITY IS NOT REAL IMPRESSIVE.
HOWEVER...THERE WILL BE A GOOD SOUTH/SOUTHWEST FLOW AHEAD OF THE
FRONT AS SEEN WITH 850MB WINDS 40-50KT AND GOOD LOW LEVEL
CONVERGENCE WITH THE FRONT. SOME STRONG STORMS WILL BE POSSIBLE.
THE MODELS DIVERGE MONDAY INTO MID WEEK WITH SOME FAIRLY LARGE
DIFFERENCES. AT THIS POINT WE HAVE LOW POPS THROUGH THAT PERIOD.
HIGHS MONDAY/TUESDAY WILL BE COOLER WITH HIGHS IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 635 AM CDT WED AUG 12 2015
MOST AREAS WERE UNDER VFR CONDITIONS EARLY THIS
MORNING...ALTHOUGH THERE HAS BEEN SOME PATCHY FOG. AN AREA OF WAA
HAS CAUSED SHOWERS AND A FEW THUNDERSTORMS TO MOVE THROUGH THE
ARROWHEAD...BUT THOSE WILL BE SHIFTING EAST EARLY TODAY.
ANOTHER AREA OF SHOWERS/STORMS WERE MOVING THROUGH MANITOBA AND
WILL TURN SOUTHEAST AS THEY CREST THE UPPER RIDGE. TIMING THIS
ACTIVITY IS A CHALLENGE AND WE RELIED ON AN ENSEMBLE APPROACH
INCLUDING USING THE CAMS. WE INTRODUCE VCSH TO KINL AROUND 22Z AND
HAVE A MENTION OF THUNDERSTORMS THERE INTO THE EVENING. THE CHANCE
FOR SHOWERS/STORMS WILL PROGRESS SOUTHEAST TONIGHT DUE TO A TROUGH
OF LOW PRESSURE AND CONTINUED WAA. INSTABILITY WILL BE INCREASING
AS WELL...SO SOME STRONG TO POSSIBLY SEVERE STORMS MAY OCCUR.
TIMING OF THE SHOWERS/STORMS WILL LIKELY NEED TO BE ADJUSTED AS
WE PROGRESS THROUGH THE DAY.
THE GRADIENT WILL TIGHTEN TODAY AND WITH GOOD MIXING...WE SHOULD
SEE GUSTY SOUTHERLY WINDS DEVELOP BY LATE MORNING/EARLY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 85 65 90 65 / 10 30 20 30
INL 88 61 88 59 / 40 50 20 10
BRD 86 66 90 65 / 10 20 10 10
HYR 82 63 86 63 / 0 40 30 20
ASX 84 64 88 62 / 10 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
SHORT TERM...JJM
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1016 AM EDT WED AUG 12 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A FEW SHOWERS
MAY DEVELOP LATER TODAY. HIGH PRESSURE WILL BUILD IN THURSDAY AND
FRIDAY WITH SEASONABLE TEMPERATURES. THE WEEKEND INTO EARLY NEXT
WEEK LOOKS TYPICAL WITH WARM TEMPERATURES AND A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY... WATER VAPOR IMAGERY MOST EFFECTIVELY AND
EFFICIENTLY TELLS THE STORM TODAY. DRY AIR NOW COVERING THE ENTIRE
REGION...DRIER IN FACT THAT SEEN IN A WHILE. THE SURFACE REMAINS
RATHER MOIST HOWEVER WITH DEWPOINTS STILL WITHIN A FEW DEGREES OF 70
AND HIGHEST ALONG THE COAST. THE FRONT TO OUR WEST IS A BIT HARD TO
PICK OUT AND THERE IS FAIR AGREEMENT BETWEEN RUC AND HRRR THAT
PRECIP IS ISOLATED AND GENERALLY ALONG THE IMMEDIATE COAST WHERE NOT
ONLY IS THERE THE MOST MOISTURE BUT ALSO THE SEA BREEZE WILL PROVIDE
THE ONLY REAL FORCING OF THE DAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 315 AM WEDNESDAY...THE MID LEVEL TROUGH WILL BE IN PLACE
THROUGH THE PERIOD ALTHOUGH IT WILL WEAKEN SOMEWHAT BY SATURDAY
MORNING. AT THE SURFACE HIGH PRESSURE WILL BE POSITIONED ALONG THE
APPALACHIANS AND BASICALLY REMAIN IN PLACE THROUGH SATURDAY AS
WELL. AN INVERTED TROUGH WILL DEVELOP OFFSHORE AS THE HIGH
WEAKENS. WILL KEEP POPS MINIMAL AS THESE FEATURE`S ALWAYS SEEM A
LITTLE OVERDONE BY GUIDANCE. TEMPERATURES WILL BE VERY PLEASANT
ALTHOUGH A LITTLE WARMER...ESPECIALLY FRIDAY THAN PREVIOUS
GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...A WEAKLY FORCED MID LEVEL PATTERN WILL EXIST
ACROSS THE SOUTHERN HALF OF THE U.S THROUGH THE PERIOD. IN
FACT...AN ELONGATED WEAK TROUGH WILL MEANDER ACROSS THE NORTHERN
GULF OF MEXICO. FOR THE EASTERN CAROLINAS...WEAK HIGH PRESSURE
WILL BE THE MAIN FEATURE. NO REAL FORCING MECHANISMS FOR ANY
ORGANIZED RAINFALL WITH THE SEA BREEZE BEING THE MAIN CATALYST.
EVEN THE PIEDMONT TROUGH APPEARS MUTED. THERE IS A HINT OF A WEAK
SHORTWAVE THAT MOVES ACROSS TUESDAY THAT MAY ENHANCE RAIN CHANCES
AND THIS IS WHERE THE HIGHEST POPS IN THE FORECAST RESIDE.
TEMPERATURES SHOULD BE SPOT ON CLIMATOLOGY.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...WINDS ARE NW IN THE LOW LEVELS PER LATEST KLTX VAD WIND
PROFILE. DESPITE SOME PATCHY LOW STRATUS AND SUB VFR VSBYS IN THE
AREA AT THE CURRENT TIME THIS WILL DISSIPATE RAPIDLY OVER THE
NEXT HOUR OR TWO. THUS THERE IS MODERATE TO HIGH CONFIDENCE VFR
WILL CONTINUE AT ALL TERMINALS THROUGH THIS MORNING. WINDS WILL BE
NW-N GRADUALLY VEERING TO THE NE.
THIS AFTERNOON WINDS WILL BECOME SE AT THE COASTAL TERMINALS.
SHOWERS SHOULD DEVELOP JUST INLAND OF THE COASTAL TERMINALS ALONG A
SEA BREEZE BOUNDARY PINNED NEAR THE COAST. WITH DRIER AIR ALOFT AND
ONLY WEAK LOW LEVEL FORCING SHOWERS SHOULD REMAIN ISOLATED. THE
GREATEST COVERAGE HOWEVER SHOULD BE SOUTH OF KMYR WHERE THE SEA
BREEZE BOUNDARY WILL INTERACT WITH A SURFACE TROUGH. ANY
THUNDERSTORMS SHOULD REMAIN WELL S OF KMYR/KFLO.
EXTENDED OUTLOOK...ISOLATED SHRA/TSRA POSSIBLE THURSDAY AND FRIDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY...POORLY DEFINED COLD FRONT STILL
APPROACHING FROM THE NORTHWEST AND STILL SLATED TO STALL VERY NEAR
THE COASTLINE. THIS WILL KEEP WIND AND SEAS MINIMAL WITH SOME
VARIABILITY/UNCERTAINTY IN THE WIND DIRECTION FORECAST ESPECIALLY
AS IT MAY BE PRONE TO MESOSCALE/SEABREEZE FLUCTUATIONS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 315 AM WEDNESDAY...A RELATIVELY WEAK NORTHEASTERLY TO EASTERLY
FLOW WILL BE IN PLACE THROUGH THE PERIOD. THIS AS HIGH PRESSURE
REMAINS TO THE NORTHEAST NEAR THE APPALACHIANS. SPEEDS MAY PICK UP
SLIGHTLY TO JUST OVER TEN KNOTS OR SO FRIDAY AS A TROUGH OFFSHORE
INCREASES THE GRADIENT SLIGHTLY. SEAS WILL BE 1-3 FEET.
LONG TERM /SATURDAY THROUGH SATURDAY/...
AS OF 315 AM WEDNESDAY...CONDITIONS WILL CHANGE VERY LITTLE FOR THE
MARINE COMMUNITY FOR THE WEEKEND. THE PRESSURE PATTERN WILL BE WEAK
THUS THE WIND FORECAST DOESN`T HAVE ANYTHING MUCH OVER TEN KNOTS.
THE SYNOPTIC FLOW WILL SHIFT TO SOUTHEAST LATER SATURDAY AND
CONTINUE SUNDAY. SEAS WILL GENEROUSLY BE 1-3 FEET AND MOSTLY 1-2
FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MRR
MARINE...REK/SHK
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EDT WED AUG 12 2015
.SYNOPSIS...A COLD FRONT MOVES THROUGH CENTRAL NORTH CAROLINA DURING
THE EARLY MORNING HOURS...WEAKENING AS IT MOVES TOWARD THE COAST AND
SOUTH CAROLINA DURING THE DAY. HIGH PRESSURE SLOWLY BUILDS INTO THE
REGION FROM THE NORTHWEST THROUGH THE END OF THE WORK WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 305 AM WEDNESDAY...
THE LATEST SURFACE ANALYSIS SHOWS THE SURFACE COLD FRONT MOVING OVER
THE NORTHWEST PIEDMONT...WITH THE DEW POINT AT KINT AND KTDF HAVING
DROPPED INTO THE MID 60S. ALTHOUGH VERY DRY MID-LEVEL AIR WAS NOTED
ON WATER VAPOR IMAGERY MOVING INTO CENTRAL NORTH CAROLINA AS A
MODERATE MID-LEVEL SHORTWAVE MOVED FROM THE LOWER GREAT LAKES TOWARD
THE VIRGINIAS...ENOUGH MID-LEVEL MOISTURE AND MINIMAL SURFACE
INSTABILITY...AROUND 100J/KG ON THE SPC MESOANALYSIS...WAS AHEAD OF
THE FRONT TO PROVIDE FOR ISOLATED SHOWERS. THESE SHOWERS...MOVING
FROM WAKE INTO JOHNSTON COUNTY...WILL RESULT IN CONTINUED MENTION OF
AN ISOLATED SHOWER INTO THE EARLY MORNING UNTIL THE FRONT SHOULD
MOVE THROUGH.
FOR THE AFTERNOON...THE MODERATE MID-LEVEL SHORTWAVE SHOULD PASS
NORTH OF CENTRAL NORTH CAROLINA. 700MB AIR IS DRY UPSTREAM ON 00Z
UPPER-AIR ANALYSES...AND GFS BUFR SOUNDINGS ARE CAPPED TO DEEP
CONVECTION. THE NAM IS CERTAINLY MORE UNSTABLE AND SLOWER WITH THE
PROGRESS OF THE FRONT...BUT IT ALSO DIGS THE SHORTWAVE A LITTLE
FARTHER SOUTH AND ITS CURRENT TRAJECTORY ON WATER VAPOR SEEMS TO
SUPPORT THE GFS. CONVECTIVE-ALLOWING MODELS AND THE RAP ARE DRY
AFTER EARLY THIS MORNING...SAVE FAR SOUTHERN SAMPSON COUNTY CLOSER
TO THE FRONT WITH HEATING AND WHERE LOW-LEVEL SHOULD DRY LAST. IN
THE GRIDDED FORECASTS WILL NOTE A SLIGHT CHANCE OF A SHOWER SOUTH OF
CLINTON AND GOLDSBORO...OTHERWISE EXPECTING THE AFTERNOON TO BE DRY
WITH HIGH-BASED CU DEVELOPING. MIXING SHOULD PROVIDE FOR A FEW WIND
GUSTS FROM THE NORTH IN THE TEENS MPH BY MID-MORNING OR SO BEFORE
925MB WINDS DIMINISH. HIGH TEMPERATURES WILL BE FORECAST CLOSE TO
THOSE IMPLIED BY THE 1000-850MB THICKNESSES AND THE SLIGHTLY COOLER
MAV MOS GUIDANCE...MID 80S TO AROUND 90.
TONIGHT...GFS BUFR SOUNDINGS WOULD SUGGEST SOME OF THE SHALLOW...
HIGH-BASED CU COULD EXPAND SOME IN THE VERY LATE AFTERNOON AND
EVENING BEFORE DIMINISHING OVERNIGHT. WINDS WILL BE LIGHT AND MAINLY
NORTHEAST. THE NAM EMPHASIZES THE POTENTIAL FOR FOG...BUT THE GFS
OVERALL IS MUCH LESS OPTIMISTIC FOR THAT AND SREF PROBABILITIES FAIL
TO REGISTER. POSSIBLY SOME GROUND FOG IN ISOLATED PATCHES LATE
TONIGHT. OVERNIGHT LOWS IN THE LOWER TO MID 60S.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 305 AM WEDNESDAY...
GFS BUFR SOUNDINGS ARE AGAIN STABLE TO DEEP CONVECTION. ITS 850MB
THETA-E VALUES DO INCREASE...WITH A RELATIVE MAXIMUM IN K INDICES
AND 850MB UVV ON THE GFS MAINLY OVER THE SOUTHERN COASTAL PLAIN AND
SANDHILLS THURSDAY AFTERNOON. THE GFS FORECASTS A WEAK INVERTED
SURFACE TROUGH OVER CENTRAL NORTH CAROLINA THURSDAY AFTERNOON...
WHILE THE NAM IS MUCH SHARPER WITH THE TROUGH AS ITS FORECAST OF
HIGH PRESSURE IS SLOWER TO BUILD SOUTH. WINDS ALOFT ARE WEAK...AND 0-
3KM SHEAR IS WEAK AS WELL WITH LIGHT 925MB WINDS. CONVECTIVE-
ALLOWING MODELS REMAIN DRY...AND WITH LIMITED LOW-LEVEL FORCING
EXPECTED...LIMITED UPPER-LEVEL SUPPORT...AND POOR INSTABILITY
ESPECIALLY ON THE GFS WITH A CAPPED SET OF BUFR SOUNDINGS AND LOW-
LEVEL MLCAPE BARELY TO 100J/KG...WILL MAINTAIN A DRY FORECAST. IF
ANY SHOWER WOULD FORM IT SHOULD BE VERY ISOLATED. GIVEN THE HIGHER
850MB THETA-E VALUES EXPECT MORE CU OVER CENTRAL NORTH CAROLINA
OVERALL...SHADING HIGHS ABOUT A DEGREE BELOW THOSE OF TODAY UNDER
BASICALLY PERSISTENCE FOR 1000-850MB THICKNESSES. OVERNIGHT LOWS
THURSDAY NIGHT GENERALLY IN THE MID 60S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...
FAIR SEASONABLE WEATHER IS EXPECTED FOR THE LATE-WEEK AND WEEKEND
PERIOD WITH HIGH PRESSURE CENTERED TO OUR NORTH EXTENDING ACROSS OUR
AREA...AND THE MAJOR SYNOP SCALE WEATHER PLAYERS REMAINING EITHER
WELL TO OUR NORTH OR TO OUR SOUTH...WITH THE NEAREST NOTABLE FEATURE
BEING THE REMNANT SFC BOUNDARY LOCATED JUST OFF THE EAST COAST.
MOISTURE POOLING INVOF OF THIS BOUNDARY MAY MOVE BACK TOWARD THE
COAST OVER THE WEEKEND...SO IT`S POSSIBLE THAT AN ISOLD SEA BREEZE
SHOWER COULD AFFECT OUR FAR SE ZONE (SOUTHERN SAMPSON CO) SAT AND
SUN AFTERNOON...BUT RIGHT NOW THE RISK IS TOO SMALL TO INCLUDE IN
THE FORECAST. WITH LOW LEVEL THICKNESSES GRADUALLY RECOVERING
THROUGH THE WEEK...HIGHS FRI THRU SUN WILL APPROACH 90 IN MANY
SPOTS...AND LOWS IN THE MID-UPR 60S...SO NORMAL TO SLIGHTLY ABOVE
NORMAL TEMPS DURING THIS TIME.
EARLY NEXT WEEK...THE UPPER RIDGE OVER THE WESTERN ALTANTIC WILL
MOVE WWD TOWARD THE GOMEX...WHILE A SHORT WAVE IN THE WESTERLIES
AMPLIFIES OVER THE TN VALLEY AS IT APPROACHES THE CAROLINAS. AS THE
RIDGE MOVES TOWARD THE GOMEX...NORTHWARD MOISTURE TRANSPORT WILL
MARKEDLY INCREASE AROUND THE PERIPHERY OF THE RIDGE...AND THAT WILL
HELP SET THE STAGE FOR SCATTERED SHOWERS/TSTMS ACROSS OUR AREA ON
TUESDAY AS THE SHORT WAVE APPROACHES FROM THE WEST. SO FOR NOW...
WILL KEEP POPS LOW ON MONDAY...ALBEIT WITH INCREASING CLOUDS...THEN
RAIN CHANCES RETURN MONDAY NIGHT AND TUESDAY AS THE SHORT WAVE
APPROACHES. TEMPS WILL CONTINUE TO RUN ABOVE NORMAL ON MONDAY BUT
COOLING SEVERAL DEGREES ON TUESDAY DUE TO CLOUDS AND RAIN.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 645 AM WEDNESDAY...
VFR CONDITIONS SHOULD PREVAIL OVER CENTRAL NORTH CAROLINA THROUGH
THE 12Z VALID TAF PERIOD...OUTSIDE OF PATCHY MOSTLY MVFR LIGHT FOG
THIS MORNING. SATELLITE IMAGERY SHOWED A SMALL PATCH OF LOW CLOUDS
JUST NORTHWEST OF KIXA...WITH A LARGER PATCH OF LOW CLOUDS IN
VICINITY OF KRWI. THESE SHOULD DIMINISH WITH MIXING THIS MORNING.
WINDS VEER TO NORTHERLY BEHIND THE FRONT WITH A FEW GUSTS IN THE
TEENS KNOTS WITH MIXING...BEFORE WINDS DIMINISH BY EARLY AFTERNOON.
SURFACE WINDS SHOULD BACK SLIGHTLY MORE NORTHWEST THIS AFTERNOON
THEN VEER BACK TO LIGHT NORTHEAST THIS EVENING AS HIGH PRESSURE
SLOWLY BUILDS IN.
BEYOND THE 12Z VALID TAF PERIOD...NAM MET MOS GUIDANCE FAVORS SOME
AREAS OF FOG DURING THE EARLY MORNING HOURS OF BOTH THURSDAY AND
FRIDAY. HOWEVER...THE GFS GUIDANCE IS MUCH LESS FOCUSED ON FOG
EXCEPT AT KRWI THURSDAY MORNING...AND SREF PROBABILITIES FOR LOW
VISIBILITIES DO NOT REGISTER BOTH EARLY THURSDAY AND EARLY FRIDAY
MORNINGS. GIVEN SOME VERY LOW-LEVEL MOISTURE AND AREAS OF COOLER LOW
TEMPERATURES...PATCHY GROUND FOG SEEMS A POSSIBILITY...BUT
CONFIDENCE IN THAT AT SPECIFIC TAF SITES IS LOW. PLAN TO INDICATE A
PERIOD OF LOW MVFR FOG AT KRWI LATE TONIGHT WHERE CONFIDENCE IS A
LITTLE HIGHER COMPARED TO OTHER TERMINALS IN CENTRAL NORTH
CAROLINA...OTHERWISE...VFR CONDITIONS ARE EXPECTED OVERALL THROUGH
SUNDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DJF
NEAR TERM...DJF
SHORT TERM...DJF
LONG TERM...RAH
AVIATION...DJF
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1011 AM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 1011 AM CDT WED AUG 12 2015
WILL CONTINUE TO BE MONITORING THE SEVERE STORM POTENTIAL FOR THIS
AFTERNOON. AREA OF STORMS ACROSS SOUTHERN MANITOBA (LOCATED WITHIN
LEFT EXIT REGION OF AN UPPER JET STREAK) LIKELY WILL REMAIN ON
EDGE OF THE MID-LEVEL CAPPING AND/OR WEAKEN THIS MORNING. WILL OF
COURSE MONITOR AND ADJUST THE FORECAST IF NEEDED. MODEL SOUNDINGS
CONTINUE TO INDICATE CONVECTIVE TEMPS IN THE UPPER 90S...SO
CAPPING LIKELY AN ISSUE TODAY. MOST CAM GUIDANCE (SUCH AS THE
OPERATIONAL HRRR AND RAP) INDICATING SFC TEMPS THIS AFTERNOON ABOVE
100F WITH WIDESPREAD CONVECTION BY 21Z. THIS HAS BEEN A BIG FLAW
OF THESE SYSTEMS...AND WILL FOLLOW THE GUIDANCE THAT INDICATES SFC
TEMPS IN THE MID-90S (SUCH AS THE EXPERIMENTAL HRRR). LOW LEVEL
CONVERGENCE SHOULD BE STRONG ENOUGH TO INITIATE AT LEAST A FEW
STORMS CLOSER TO 00Z (ESPECIALLY NW MN...BUT COULD EXTEND INTO SE
ND DEPENDING ON LOCAL DEW POINTS). ANY STORM HAS THE POTENTIAL TO
BE SEVERE GIVEN THE EXPECTED BACKGROUND ENVIRONMENT. MORE OR LESS
AN INVERTED-V TYPE SOUNDING SO DAMAGING WIND GUSTS (AND SOME
LARGER HAIL) LIKELY THE MAIN THREAT. SPC DID UPGRADE TO A SLIGHT
RISK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 336 AM CDT WED AUG 12 2015
HOT TEMPS AND LATE AFTERNOON/EVENING THUNDERSTORM CHANCES
HIGHLIGHT THE SHORT TERM CONCERNS.
WHILE THE UPPER RIDGE WILL REMAIN CENTERED OVER THE ROCKIES
TODAY...WARMER 850 MB TEMPS WILL SPREAD INTO THE AREA...WITH AN
INCREASE OF ABOUT 3C OVER YESTERDAY. WITH INCREASINGLY BREEZY SW
WINDS AHEAD OF A SFC TROUGH/WEAK COLD FRONT...TEMPS SHOULD EASILY
CLIMB SEVERAL DEGREES HIGHER THAN YESTERDAY INTO THE UPPER 80S TO
MID 90S. RECORD HIGHS TODAY AT KFAR/KGFK ARE 101/98F
RESPECTIVELY...AND 96F AT NWS FGF. HEAT INDICES MAY REACH THE
UPPER 90S IN SOME SPOTS FOR A TIME THIS AFTERNOON.
THE AFOREMENTIONED SFC TROUGH WILL SHIFT INTO THE N RRV/DEVILS
LAKE BASIN BY LATE AFTERNOON. UPPER SUPPORT WILL BE LIMITED WITH
THE UPPER SHORTWAVE TROUGH PASSING EAST OF THE AREA...BUT
CONVERGENCE ALONG THE BOUNDARY MAY BE SUFFICIENT FOR
ISOLATED/WIDELY SCATTERED STORMS LATE TODAY INTO THE EVENING AS
CIN ERODES NEAR THE BOUNDARY. SPC HAS MAINTAINED A MARGINAL RISK
FOR SVR OVER FAR NE ND AND NW MN. GIVEN EXPECTED DEW POINTS WELL
INTO THE 60S AND STEEP LAPSE RATES...MLCAPE ABOVE 2500 OR 3000
J/KG IS EXPECTED WITH ~40 KTS OF DEEP SHEAR. THE VERY WARM...DEEP
WELL MIXED BOUNDARY LAYER SUGGESTS POTENTIAL FOR SEVERE WIND GUSTS
WITH HAIL POSSIBLE AS WELL (GIVEN THE INSTABILITY AND POTENTIAL
FOR SUPERCELLS). KEPT MAINLY SLIGHT/CHANCE POPS DUE TO THE
EXPECTED COVERAGE. STORMS SHOULD PROGRESS SOUTH AND EAST AND
LIKELY EXIT THE AREA BY LATE EVENING.
A WEAK SFC FLOW REGIME IS EXPECTED THURSDAY WITH SOME MODEL
DISCREPANCIES AS TO THE PLACEMENT OF A DIFFUSE BOUNDARY. IN
ADDITION...MODELS INDICATE AN UPPER WAVE ROTATING AROUND THE UPPER
RIDGE INTO THE N PLAINS. WITH LOW CONFIDENCE IN ANY CONVECTIVE
CHANCES...LARGELY MAINTAINED IDEA FROM PREVIOUS FORECAST WITH SOME
LOW POPS IN THE FAR SOUTH/WEST. THERMAL PROFILES REALLY DON/T
CHANGE MUCH...SO EXPECT ANOTHER VERY WARM DAY. HOWEVER...WILL HAVE
TO WATCH OUT FOR CLOUD COVER...WHICH COULD LIMIT TEMPS A BIT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 AM CDT WED AUG 12 2015
SFC HIGH PRESSURE WILL WORK INTO THE AREA THURSDAY
NIGHT/FRIDAY. ANOTHER HOT DAY IS IN STORE WITH HIGHS NEAR OR ABOVE
90 IN MOST AREAS. FRIDAY NIGHT WILL BE MILD AS WINDS BECOME
SOUTHERLY AHEAD OF LOW PRESSURE DEVELOPING TO THE WEST.
SATURDAY THROUGH TUESDAY...THE PATTERN BEGINS TO SHIFT AT THE START
OF THE PERIOD AS ALL MODELS ARE IN PRETTY GOOD AGREEMENT ON THE
RIDGE STARTING TO BREAK DOWN THANKS TO A SIGNIFICANT SHORTWAVE
MOVING INTO SOUTHERN CANADA...ALTHOUGH THERE ARE DIFFERENCES IN
TIMING. THE GFS IS FASTER THAN THE INTERNATIONAL MODELS...BUT STILL
HAS SOUTHERN WINDS FOR MUCH OF THE DAY ON SATURDAY AHEAD OF THE SFC
TROUGH AXIS AND COLD FRONT. WILL CONTINUE TO KEEP SATURDAY
HOT...WITH PRECIP MOSTLY IN THE WEST AND THEN ACROSS THE ENTIRE CWA
SATURDAY NIGHT AS THE COLD FRONT MOVES THROUGH. SUNDAY AND INTO THE
EARLY PART OF NEXT WEEK SHOULD SEE TEMPS BELOW SEASONAL AVERAGES AS
THE COOL AIR MASS SETTLES IN BEHIND THE FRONT. THE GFS BRINGS A WEAK
SHORTWAVE JUST SOUTH OF THE CWA MONDAY AND CLIPS THE AREA NEAR THE
SD BORDER WITH PRECIP. NOT OUT OF THE QUESTION...SO WILL KEEP THE
LOW POPS THAT THE BLENDED SOLUTION GIVES US BUT THINK THE MAIN
PRECIP CHANCES WILL BE MORE TOWARDS MID WEEK AS THE NEXT STRONG
TROUGH MOVES OUT INTO THE PLAINS. FLOW WILL BE MORE
SOUTHWESTERLY...AND THIS TIME THE ECMWF IS A BIT FASTER ON BRINGING
THE SHORTWAVE INTO THE WESTERN PLAINS BY TUESDAY AFTERNOON. THE GFS
IS SLOWER AND DRIER SO WILL KEEP THE CHANCE POPS GOING FOR NOW.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 653 AM CDT WED AUG 12 2015
VFR CONDITIONS EXPECTED THROUGH MOST OF THE PERIOD. SW WINDS WILL
INCREASE...POSSIBLY GUSTING OVER 20 KTS BY LATE MORNING AHEAD OF A
SFC TROUGH...WHICH WILL MOVE THROUGH KDVL THIS AFTERNOON WITH
WINDS BECOMING WEST TO NORTHWEST. WINDS WILL DIMINISH THIS
EVENING...BECOMING LIGHT OVERNIGHT. ISOLATED TO WIDELY SCATTERED
STORMS MAY DEVELOP LATE THIS AFTERNOON INTO THE EVENING. WHILE A
STORM CANNOT BE RULED OUT AT ANY SITE...THE HIGHEST CHANCES APPEAR
TO BE AT KBJI AND KTVF. INCLUDED VCTS AT KGFK/KTVF/KBJI FOR
NOW...AS COVERAGE AND TIMING IS SOMEWHAT UNCERTAIN.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...JAM
LONG TERM...JAM/JR
AVIATION...JAM
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
613 AM CDT WED AUG 12 2015
.AVIATION...12/12Z TAF ISSUANCE...
LOW/MID LEVEL BKN/OVC DECK OF ACCAS WILL CONTINUE TO BUILD OVER
NWRN OK INTO PORTIONS OF CENTRAL AND WESTERN OK THROUGH THE
MORNING. PRIMARY AVIATION CONCERN WILL BE INCREASING THUNDERSTORM
ACTIVITY OVER NWRN OK THROUGH THE MORNING... IMPACTING KWWR/KGAG.
FELT TEMPOS WERE MOST APPROPRIATE GIVEN LOW CONFIDENCE IN
TIMING/COVERAGE. ELSEWHERE... VFR CONDITIONS ARE EXPECTED TO
PREVAIL... WITH SCT TO BKN MID-LEVEL CLOUDS PERSISTING THROUGH
MUCH OF THE PERIOD AND LIGHT TO MODERATE EASTERLY WINDS.
JTK
&&
.PREV DISCUSSION... /ISSUED 258 AM CDT WED AUG 12 2015/
DISCUSSION...
THIS MORNING... SCATTERED SHOWERS CONTINUE TO EVOLVE ACROSS SERN KS
INTO FAR NWRN OK. THIS ACTIVITY IS BEING DRIVEN ALONG A MID-LEVEL
BAROCLINC ZONE OF MOISTURE AND ASCENT WITH THE H700 HIGH CENTERED
OVER THE LLANO ESTACADO IN W CENTRAL TX NEAR LUBBOCK PER SPC
MESOANALYSIS. GOOD REPRESENTATION OF CORRIDOR OF MOISTURE AND ASCENT
CAN BE VISUALIZED ON THE 310 AND 315K ISENTROPIC SURFACES. LATEST
RUNS OF THE HRRR THIS MORNING APPEAR TO BE A TAD BULLISH THROUGH
SUNRISE... DEVELOPING A FAIRLY WIDE AREA OF PRECIP ACROSS SWRN KS
INTO THE NERN PANHANDLES AND NWRN OK. HOWEVER... THE 12/00Z RUN OF
ARW/NMM WRFS ARE ALSO A TAD AGGRESSIVE WITH CONVECTION. SHORT RANGE
SOLUTIONS FROM THE NAM/GFS/ECMWF SUGGEST A SLIGHT UPTICK IN THE LLJ
THROUGH 12Z. IF THIS OCCURS... WE COULD SEE SOME INCREASED
CONVECTIVE DEVELOPMENT THROUGH SUNRISE... MAYBE NOT ON THE ORDER OF
THE HRRR/WRF... BUT MORE THAN WHATS BEEN OCCURRING THROUGH 08Z (3
AM). EITHER WAY... EXPECT AT LEAST SCATTERED DEVELOPMENT TO PERSIST
THROUGH THE MORNING AND LINGER THROUGH THE AFTN ACROSS W/NW OK.
THIS AFTERNOON... BESIDES LINGERING SHOWER/THUNDERSTORM CHANCES...
INCREASING CLOUD COVER THIS AM ACROSS W/NW OK WILL HAVE AN IMPACT ON
AFTN TEMPS. HIGHS THIS AFTN WILL STRUGGLE TO CLIMB INTO THE UPPER
80S... LIKELY SETTLING IN THE MID 80S ACROSS NWRN OK. ELSEWHERE...
EXPECT UPPER 80S TO MID 90S FROM CENTRAL OK INTO NRN TX.
TONIGHT... CONTINUE TO KEEP A SLIGHT CHANCE FOR SCATTERED SHOWERS
AND THUNDER GOING FOR W/NW OK THROUGH THU AM. WITH THE H500 RIDGE
GOING NOWHERE FAST... MID-LEVEL MOISTURE WILL HOLD AND ASCENT WILL
BE SIMILAR TO THIS MORNING... KEEPING A LOW CHANCE FOR ISOLATED TO
SCATTERED CHCS.
FOR THE REMAINDER OF THE WEEK... SEASONABLE TEMPS WILL HOLD THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. THERE ALSO REMAINS A SLIGHT
CHANCE OF SCATTERED SHOWERS AND THUNDERSTORMS FRI ACROSS PORTIONS OF
WRN OK/WRN N TX AS A WEAK H500 SHORTWAVE TRAVERSES THE HIGH. CHCS
WILL LINGER INTO EARLY SAT. OTHER THAN THAT... EXPECT A DRY AND
PLEASANT SUMMER WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 88 66 90 68 / 10 10 0 10
HOBART OK 91 69 94 71 / 10 10 10 0
WICHITA FALLS TX 93 71 95 72 / 10 10 0 0
GAGE OK 86 66 91 70 / 40 20 0 0
PONCA CITY OK 89 65 90 69 / 10 0 0 0
DURANT OK 95 70 94 67 / 0 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
99/99/01
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
637 AM MDT WED AUG 12 2015
.UPDATE...
ISSUED AT 627 AM MDT WED AUG 12 2015
RECENT 11-3.9 MICROMETER SATELLITE IMAGERY AND SURFACE OBS ARE NOW
SHOWING PATCHY FOG OVER PORTIONS OF SOUTHEAST WYO AND THE WESTERN
NEB PANHANDLE. DESPITE AN INCREASE IN MIDLEVEL CLOUD COVER...LIGHT
WINDS AND EXCELLENT BOUNDARY LAYER MOISTURE WITH DEW POINTS IN THE
50S TO AROUND 60 F ARE LIKELY CONTRIBUTING TO THIS. GIVEN SEVERAL
OBS INDICATING TEMP-DEWPOINT SPREADS LESS THAN 2 DEG F...ISSUED A
QUICK GRID UPDATE TO INCLUDE PATCHY FOG ALONG/EAST OF THE LARAMIE
RANGE THROUGH 15Z THIS AM. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
PERSISTENCE. THAT IS THE NAME OF THE GAME THROUGH MOST OF THE SHORT
TERM PERIOD AS HIGH-AMPLITUDE UPPER LEVEL RIDGING REMAINS ANCHORED
OVER THE CENTRAL ROCKIES THROUGH THE END OF THE WORK WEEK. THIS WILL
RESULT IN TYPICAL WYOMING WEATHER FOR MID AUGUST...AS HIGH PRESSURE
CENTERED OVER TX/OK WILL YIELD A PERSISTENT FEED OF MONSOON MOISTURE
STREAMING NORTHWARD INTO THE CWA. CONVECTIVE CHANCES WILL EXIST EACH
AFTERNOON/EVENING...AND MOST AREAS WILL SEE VERY LITTLE VARIATION IN
HIGHS FROM DAY TO DAY. IN THE NEAR TERM...DECIDED TO REMOVE MENTION
OF FOG EARLY THIS AM AS NAM/GFS BUFKIT SOUNDINGS SUGGEST ONLY MODEST
LLVL SATURATION AND THE HRRR KEEPS VISIBILITY HIGH. SCATTERED STORMS
SHOULD DEVELOP ALONG/WEST OF THE LARAMIE RANGE THIS AFTERNOON...AND
BECOME MORE WIDESPREAD AFTER 00Z AS A PRONOUNCED MID LEVEL VORT MAX
TRACKS ACROSS CENTRAL WYO. WOULD EXPECT THIS TIME PERIOD TO BE MORE
ACTIVE THAN THE REST OF THE PERIOD GIVEN COOLER MID LEVEL TEMPS AND
GENERALLY BETTER DYNAMICS. NO SEVERE WEATHER EXPECTED WITH LESS THAN
15 KTS OF H5 FLOW...BUT SLOW MOVING STORMS COULD YIELD SOME CONCERNS
FOR FLASH FLOODING WITH GFS PWATS OVER ONE INCH. THERMAL ENVIRONMENT
WILL BECOME WARMER AND MORE CAPPED LATER IN THE WEEK...SO EXPECT THE
BEST CHANCES FOR CONVECTION TO BE OVER HIGHER TERRAIN ON THU/FRI. H7
TEMPS AVERAGING AROUND +14 TO +16 C FROM ALL MODELS SUGGESTS A WARM
FORECAST PERIOD WITH HIGHS AROUND 90 F OVER MUCH OF THE PLAINS.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL
HIGH...CENTERED NEAR THE FOUR CORNERS REGION...SLOWLY RETROGRADING
AND WEAKENING A BIT BY SUNDAY...AS ENERGY FROM THE NORTHERN
PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES. UNTIL
THEN...EXPECT THE PERSISTENT WEATHER PATTERN TO CONTINUE INTO THE
WEEKEND WITH SOUTHWEST FLOW ALOFT AND DAYTIME CONVECTION DUE TO
THE ADVECTION OF MONSOON MOISTURE FROM THE SOUTHWEST UNITED
STATES. HIGH TEMPERATURES WILL BE ABOVE NORMAL SATURDAY WITH
READINGS IN THE 80S TO MID 90S ACROSS MOST OF THE AREA. PORTIONS
OF WESTERN NEBRASKA AND FAR EASTERN WYOMING MAY REACH THE UPPER
90S ON FRIDAY AS 700MB TEMPERATURES PEAK BETWEEN 15C TO 18C. WITH
PW/S OVER ONE INCH ACROSS THE HIGH PLAINS...THERE WILL BE PLENTY
OF MOISTURE FOR SHOWERS AND TSTORMS TO DEVELOP. HOWEVER...STILL NOT
CONFIDENT ON THE COVERAGE ON SATURDAY DUE TO THE STRENGTH OF THE
UPPER LEVEL HIGH WHICH WILL RESULT IN SUBSTANTIAL MIDLEVEL
SUBSIDENCE...AND MAY SUPPRESS SCATTERED CONVECTION.
HOWEVER...SOME OF THESE TSTORMS MAY CONTAIN VERY HEAVY RAINFALL
WITH ISOLATED FLASH FLOODING POSSIBLE. SEVERE TSTORMS APPEAR
UNLIKELY AT THIS TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
MODELS ARE TRENDING TOWARDS BETTER AGREEMENT AND ARE MORE
CONSISTENT WITH THE OVERALL PATTERN NEXT WEEK. THE GFS HAS TRENDED
TOWARDS THE ECMWF SOLUTION...SHOWING A SERIES OF STRONG COLD
FRONTS FOR THIS TIME OF THE YEAR MOVING ACROSS THE REGION. MODELS
SHOW A STRONG PACIFIC TROUGH MOVING INTO WYOMING ON TUESDAY WITH A
STRONG COLD FRONT MOVING ACROSS THE AREA. IF THE ECMWF SOLUTION
VERIFIES...TEMPERATURES MAY BE AUTUMN-LIKE BY NEXT WEDNESDAY.
COOLER AIR MAY SPREAD INTO THE HIGH PLAINS AS EARLY AS MONDAY WITH
ALL MODELS SHOWING A SHALLOW BACK-DOOR COLD FRONT MOVING SOUTHWEST
ACROSS THE HIGH PLAINS. LOWERED HIGH TEMPERATURES INTO THE 80S
ALONG AND EAST OF THE I25 CORRIDOR. THE MAIN COLD FRONT IS
FORECAST TO PUSH ACROSS THE AREA SOMETIME ON WEDNESDAY...WITH
TEMPERATURES POTENTIALLY LOWERING BELOW NORMAL. MODELS ARE
RELATIVELY DRY WITH THIS FRONTAL PASSAGE...BUT GIVEN THE DYNAMICS
AND RELATIVELY HIGH PW/S ACROSS THE PLAINS...BELIEVE THERE WILL BE
SOME SHOWER/TSTORM ACTIVITY AHEAD AND BEHIND THE FRONT. KEPT POP
AROUND 20 PERCENT FOR NOW...BUT LOWERED TEMPERATURES INTO THE 70S
ACROSS MOST OF SOUTHEAST WYOMING AND NORTHERN NEBRASKA.
KEEP IN MIND THESE FORECAST TEMPERATURES ARE STILL 10 TO 15
DEGREES WARMER THAN WHAT THE ECMWF INDICATES TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH WEDNESDAY NIGHT)
ISSUED AT 217 AM MDT WED AUG 12 2015
LOW CONFIDENCE IN FOG DEVELOPMENT OVER THE SOUTHERN NEBRASKA
PANHANDLE THIS MORNING SINCE WINDS HAVE STARTED TO SHIFT INTO THE
SOUTH AND SOUTHWEST...WITH DEWPOINTS HOVERING AROUND 5 TO 10
DEGREES BELOW THE AIR TEMPERATURE. INCREASED VIS AND REMOVED
OVERCAST CONDITIONS OVER A FEW TERMINALS...BUT CAN NOT RULE OUT
SOME LOW CIGS AND LIGHT MIST NEAR KSNY AND KBFF BETWEEN 10Z TO
15Z THIS MORNING. OTHERWISE ANOTHER ROUND OF SHOWERS AND TSTORMS
ARE EXPECTED OVER SOUTHEAST WYOMING THIS AFTERNOON...AND GRADUALLY
OVER WESTERN NEBRASKA BY THIS EVENING. BRIEF IFR VIS ARE POSSIBLE
IN THE HEAVIER SHOWERS.
&&
.FIRE WEATHER...
ISSUED AT 217 AM MDT WED AUG 12 2015
NO MAJOR FIRE WEATHER CONCERNS THROUGH FRIDAY WITH WIND GUSTS LIKELY
TO REMAIN BELOW 25 MPH AND AFTN HUMIDITIES ABOVE 20-25 PCT. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS SHOULD OCCUR EACH DAY GIVEN A
TYPICAL MONSOON PATTERN IN PLACE. BEST CHANCE FOR WETTING RAINS WILL
BE LATE THIS AFTERNOON AND OVERNIGHT. AS USUAL...EXPECT GUSTY AND/OR
ERRATIC WINDS NEAR THUNDERSTORMS IN ADDITION TO FREQUENT CLOUD-TO-
GROUND LIGHTNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
334 PM MDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 334 PM MDT WED AUG 12 2015
CURRENTLY...
LINE OF Q NOTED OVER THE FAR SE PLAINS. SPC ANALYSIS INDICATES 3000
J/KG MIXED CAPE OVER THIS REGION. IN ADDITION...SPC NON SUPERCELL
TORNADO INDICES ARE INCREASING OVER THIS SAME AREA.
ELSEWHERE...ISOLD CONVECTION WAS NOTED OVER THE MTNS.
THIS AFTERNOON...
MAIN SHORT TERM CONCERN IS BOUNDARY OUT EAST. GIVEN THE
CAPE...INCREASING VALUES ON THE NON SUPERCELL SPC PAGE AND HRRR
SHOWING CONVECTION INITIATING OVER THE REGION...CANT RULE OUT A WEAK
ROPE TORNADO DEVELOPING BETWEEN NOW AND LATE AFTERNOON OVER E
KIOWA...PROWERS AND POSSIBLY BACA COUNTIES. OTHER CONVECTION WILL
CONTINUE TO DEVELOP OVER THE HIGHER TRRN AND POSSIBLY THE LOWER
ELEVATIONS OF EL PASO COUNTY. CANT RULE OUT AN ISOLD STORM
DEVELOPING OVER THE REST OF THE PLAINS.
TONIGHT...
WITH LIMITED FORCING OVER THE REGION...CONVECTION THAT DOES INITIATE
SHOULD DECREASE AFTER SUNSET THIS EVENING. LATEST HRRR GUIDANCE
LOOKS A LITTLE HEAVY HANDED REGARDING CONVECTION INTENSITY AND
DURATION FOR THIS EVENING. I CANT RULE OUT AN ISOLD STORM LINGERING
INTO THE EVENING HOURS...BUT OVERALL NOT MUCH CONVECTION ANTICIPATED
TONIGHT.
LOW TEMPS TONIGHT SHOULD BE IN THE M/U60S PLAINS WITH 40S AND 50S
MTNS/VALLEYS.
TOMORROW...
WEAK BOUNDARY WILL COME DOWN THE PLAINS TOMORROW AND MONSOON MSTR
WILL LINGER OVER THE EASTERN PLAINS. ALTHOUGH THE BRUNT OF THE
DEEPER MSTR WILL BE OVER THE CONTDVD AND WESTWARD...ENOUGH FORCING
WILL BE OVER THE PLAINS AND MTNS FOR ISOLD TO SCT ACTIVITY DURING
THE LATER AFTERNOON TIME PD. NAM APPEARS TO BE THE MOST HEAVY
HANDED OF ALL THE GUIDANCE AND APPEARS OVERDONE...BUT GIVEN THE
SOMEWHAT FAVORABLE LLVL FORCING...WE MAY SEE AN UPTICK IN
CONVECTION OVER THE PLAINS LATE TOMORROW AFTERNOON.
EXPECT MAX TEMPS TOMORROW TO BE IN THE L/M90S WITH 80S IN THE COS
REGION...AND 70S AND 80S IN THE THE MTNS. HODANISH
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 334 PM MDT WED AUG 12 2015
THURSDAY NIGHT THROUGH SATURDAY...A LARGE UPPER HIGH CONTINUES TO BE
CENTERED OVER THE REGION THROUGH FRIDAY KEEPING WINDS ALOFT
LIGHT...BEFORE FLATTENING OUT AND EDGING TO THE SOUTH BEGINNING
SATURDAY. MOISTURE TRAPPED UNDER THE HIGH WILL FEED DIURNAL AFTN AND
EVE MT SHOWERS AND STORMS...AND STORMS THAT DO DEVELOP WILL BE SLOW-
MOVING AND MOVEMENT WILL BE DIFFICULT TO ANTICIPATE. LOOK FOR MAX
TEMPS TO REMAIN STEADY THROUGH THE PERIOD WITH AFTN HIGHS IN THE 80S
FOR THE HIGH VALLEYS...AND 80S TO MID 90S FOR THE E PLAINS.
SUNDAY AND MONDAY...THE UPPER HIGH GETS PUSHED TO THE SOUTH AS A
SHORTWAVE CROSSES THE NORTHERN ROCKIES LATE SAT THROUGH MON...WITH
THE HIGH CENTER SETTLING OVER AZ. THE SHORTWAVE PUSHES A COLD FRONT
DOWN INTO E CO ON SUN...WITH MODELS SAYING THE FRONTAL PASSAGE OVER
THE PALMER DVD SOMETIME IN THE LATE MORNING. AFTER A WARM DAY
SUN...THE FRONT MAY HELP TO COOL TEMPS A FEW DEGREES ON MON...WITH
HIGHS IN THE 80S TO NEAR 90 FOR THE PLAINS...AND AROUND 80 FOR THE
HIGH VALLEYS. AS FOR PCPN...THERE LOOKS TO BE A SLIGHT INCREASE IN
POPS SUN...BUT MORE SO SUN EVE AND DEFINITELY INTO MON. THE BEST
WINDOW FOR WIDESPREAD PCPN COVERAGE COMES MON AFTN AND EVE ACROSS
ALL OF THE MTS AND E PLAINS.
TUESDAY AND WEDNESDAY...THE EXTENDED PERIOD GETS INTERESTING AS
MODELS AGREE ON DROPPING A STRONG UPPER LOW DOWN ACROSS THE PAC NW
ON MON...BUT THEN THE SOLUTIONS DIVERGE. THE EC WANTS TO CONTINUE
DROPPING THE LOW INTO THE GREAT BASIN TUE AND WED...WHILE THE GFS
SWEEPS THE LOW DUE EAST ACROSS ID AND MT. FOR NOW WENT WITH ISOLATED
TO SCATTERED MT CONVECTION TUE AFTN AND EVE...THEN COOLER AND DRIER
FOR WED. MOORE
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 334 PM MDT WED AUG 12 2015
OVERALL EXPECT VFR CONDITIONS NEXT 24H AT ALL 3 TAF
SITES...KPUB...KALS AND KCOS. CANT RULE OUT AN ISOLD TSRA THIS
AFTERNOON ESPECIALLY OVER THE KCOS REGION...AND A SLIGHTLY BETTER
CHANE OF CONVECTION TOMORROW AFTERNOON OVER KCOS AND KPUB. WINDS
WILL BE LIGHT...EXCEPT IN AND NEAR -TSRA.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...MOORE
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
539 PM CDT WED AUG 12 2015
...Updated for Aviation...
.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 250 PM CDT WED AUG 12 2015
Temperatures for later this afternoon were necessarily trimmed again
by the HRRR due to widespread cloudiness, rain and cooled air near
the moist upslope convergence zone region between roughly highway 183
and 83. Although the areal coverage has been dramatically reduced
this afternoon, isolated showers could occur easily still occur
through tonight. The convective allowing models as a whole are far
less supportive of additional shower and thunderstorms development
heading into Thursday, perhaps partially owing to less of a
convergence zone with as surface winds turn southerly. With a lack
of widespread precipitation and/or cloudiness, the opportunity for
much warmer raw model forecast temperatures reaching into the 90s
is likely, which will be the case over the next several days.
.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 250 PM CDT WED AUG 12 2015
The best chances for precipitation will be a very slight chance for
most of the area, with a best chance in west central Kansas around
Sunday night, when models forecast shortwave energy across the
northern high plains. It is possible the entire area remains dry
during this time. A better opportunity arrives by mid week ,and
could last several days as a baroclinic zone impacts the region
with a breakdown of the upper ridge.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z Thursday EVENING)
ISSUED AT 534 PM CDT WED AUG 12 2015
Light upslope winds will continue tonight, then become more
southerly by mid morning with VFR conditions expected into
Thursday. Some models hint at some convection after 05Z however
confidence is too low to put into forecast attm.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 89 67 91 / 10 10 10 10
GCK 64 90 66 91 / 10 0 10 10
EHA 65 92 66 91 / 0 0 10 10
LBL 66 92 67 92 / 10 0 10 10
HYS 65 90 67 92 / 10 10 20 10
P28 66 90 69 91 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
251 PM CDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH Thursday)
ISSUED AT 250 PM CDT WED AUG 12 2015
Temperatures for later this afternoon were necessarily trimmed again
by the HRRR due to widespread cloudiness, rain and cooled air near
the moist upslope convergence zone region between roughly highway 183
and 83. Although the areal coverage has been dramatically reduced
this afternoon, isolated showers could occur easily still occur
through tonight. The convective allowing models as a whole are far
less supportive of additional shower and thunderstorms development
heading into Thursday, perhaps partially owing to less of a
convergence zone with as surface winds turn southerly. With a lack
of widespread precipitation and/or cloudiness, the opportunity for
much warmer raw model forecast temperatures reaching into the 90s
is likely, which will be the case over the next several days.
.LONG TERM...(Thursday NIGHT THROUGH Wednesday)
ISSUED AT 250 PM CDT WED AUG 12 2015
The best chances for precipitation will be a very slight chance for
most of the area, with a best chance in west central Kansas around
Sunday night, when models forecast shortwave energy across the
northern high plains. It is possible the entire area remains dry
during this time. A better opportunity arrives by mid week ,and
could last several days as a baroclinic zone impacts the region
with a breakdown of the upper ridge.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z Thursday AFTERNOON)
ISSUED AT 144 PM CDT WED AUG 12 2015
Surface low pressure over Missouri was leading to southeasterly
surface winds across the area. Decaying convection has left a few
scattered showers remaining near the DDC terminal, however the
activity will continue on the downtrend. For the remainder of the
TAF period, the ceilings are forecast to increase in height with
winds decoupling around sunset.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 91 67 92 / 20 10 10 10
GCK 64 91 66 92 / 10 10 10 10
EHA 65 93 66 92 / 10 10 10 10
LBL 66 92 67 92 / 10 10 10 10
HYS 65 91 67 93 / 20 10 20 20
P28 66 90 69 92 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...Russell
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GAYLORD MI
200 PM EDT WED AUG 12 2015
.UPDATE...
ISSUED AT 131 PM EDT WED AUG 12 2015
DIURNAL CU OS OVER THE FORECAST AREA. TEMPERATURES ARE PRETTY MUCH
FOLLOWING THE EXPECTED CURVE FOR THE DAY. MID CLOUDS ARE HAVING A
HARD TIME GETTING INTO THE FORECAST AREA WITH THE DRY AIR ALOFT AS
EVIDENCED BY THE CLOUDS IN W UPPER AND C UPPER. MAIN CONCERN FOR
TONIGHT WILL BE THE VORT MAX THAT IS IN SE MANITOBA, SO NO CHANGES
IN THE CURRENT FORECAST.
UPDATE ISSUED AT 952 AM EDT WED AUG 12 2015
HIGH PRESSURE TO THE WEST IS MOVING SOUTH FROM THE UPPER GREAT
LAKES, TO THE LOWER OHIO VALLEY. THIS HAS BEEN MIXING OUT AND
PUSHING WHAT STRATOCU WE HAVE HAD LEFT OVER, FROM THE OVERNIGHT.
UPSTREAM, THE RETURN FLOW ON THE NORTH SIDE OF THE HIGH IS
BEGINNING TO PRODUCE RAIN SHOWERS AND SOME THUNDERSTORMS NEAR
THUNDER BAY, ONTARIO THIS MORNING. HOWEVER, AS IT MOVED OUT OVER
LAKE SUPERIOR, IT HAS DIED, AND LOOKS LIKE THE CLOUD COVER IS
BEGINNING TO MIX OUT HAS IT MOVES TO THE SSE. SO THE AFTERNOON, IT
LOOKS LIKE WE SHOULD REMAIN DRY, BUT WILL EXPECT THAT THE RAIN
WILL GET GOING BETTER BY EVENING AS THE RETURN FLOW AND A 500 MB
SHORTWAVE TROUGH MOVE INTO THE UPPER GREAT LAKES OVERNIGHT. THIS
WILL HELP TO KICK OFF SOME THUNDER ACTIVITY.
&&
.NEAR TERM...(TODAY THROUGH TONIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL...A CHANCE OF THUNDERSTORMS TONIGHT.
HIGH PRESSURE EXTENDS FROM EASTERN KS TO NW WI. JUST IN ADVANCE OF
THE HIGH...PATCHY STRATOCU REMAINS FRUSTRATINGLY STUBBORN OVER A
PORTION OF NORTHERN MI...THOUGH THE LOW CLOUDS ARE SLOWLY ERODING
WITH TIME. THE HIGH WILL DRIFT SE TOWARD THE OHIO VALLEY THRU
TONIGHT. SHOWERS ARE OCCURRING IN THE WARM/MOIST ADVECTION ZONE ON
THE NORTH FLANK OF THE HIGH...JUST NORTH OF MN. WE WILL ENTER THAT
REGION VERY LATE TODAY INTO TONIGHT...WITH A WARM FRONT ADVANCING
INTO NORTHERN MI LATE TONIGHT. MOST OF TODAY WILL BE QUIET...BUT
CHANCES FOR PRECIP WILL BE INCREASING AS WE MOVE INTO TONIGHT.
TODAY...ONGOING CLOUD COVER WILL ERODE THIS MORNING...THANKS TO
HEATING/MIXING...AND THE ARRIVAL OF A NARROW AXIS OF SOMEWHAT DRIER
AIR NOW OVER WI AND CENTRAL UPPER MI. THAT WILL BE FOLLOWED BY
THE ARRIVAL OF SOME BUBBLY ALTOCU...THE WARM-ADVECTION CLOUD COVER
NOW NORTH OF MN. THE NAM IS CONSIDERABLY FURTHER EAST WITH THE
WARM FRONT LATE TODAY...REACHING A CMX-GRB LINE. THIS RESULTS IN
THE NAM ALLOWING CONVECTION TO REACH NW LOWER MI LATE IN THE
AFTERNOON. GIVEN THE NNW FLOW ALOFT...UPSTREAM RADAR/CLOUD
TRENDS...AND THE BULK OF THE OTHER SHORT-TERM GUIDANCE...THIS
LOOKS TOO FAST. SOMETHING CLOSER TO THE RAP IS PREFERRED...KEEPING
THE WARM FRONT IN CENTRAL WI AND -SHRA IN EASTERN WI/WESTERN UPPER
MI. SOME ACCAS WILL EXPAND IN NW LOWER MI LATE IN THE DAY...BUT
WILL KEEP THE FORECAST DRY THRU 8 PM.
HIGHS WILL BE IN THE 70S.
TONIGHT...WARM FRONT WILL MOVE EAST TOWARD A MUNISING-HTL LINE BY
DAWN. AN AREA OF SHRA EAST OF THE FRONT...STARTING THE EVENING OVER
NE WI/NORTHERN LAKE MI/CENTRAL UPPER WILL MOVE SE...ASSOCIATED WITH
A WEAK BUT FAST-MOVING SHORTWAVE DIVING ACROSS MI. THIS WILL POSE A
RISK FOR PRECIP ACROSS ROUGHLY THE SW HALF OF THE FORECAST AREA...
MAINLY DURING THE EVENING (WILL MAINTAIN A RISK OF PRECIP OVERNIGHT
SOUTH OF M-72). NAM LOVES IT/S LOW LEVEL MOISTURE AND GOES
BONKERS WITH MUCAPE. BUT EVEN A MORE REALISTIC MOISTURE PORTRAYAL
GIVES US HIGH THREE-FIGURES OF CAPE...SO WILL ADD THUNDER. WILL
STILL JUST KEEP POPS IN THE CHANCE CATEGORY. A BIT OF SHORTWAVE
RIDGING ARRIVES OVERNIGHT FROM THE NW...PROVIDING A LULL. ANOTHER
BATCH OF PRECIP MAY TRY TO GET GOING BACK BEHIND THAT RIDGE OVER
WESTERN LAKE SUPERIOR AND ENVIRONS. ANY SUCH ACTIVITY LOOKS
UNLIKELY TO REACH THIS FORECAST AREA BY MORNING.
MIN TEMPS WILL BE MILD...ESPECIALLY IN NW LOWER...WHERE A WARMER/
STICKIER AIRMASS WORKS IN BEHIND THE WARM FRONT. LOWS WILL BE
IN THE MID 50S TO MID 60S.
&&
.SHORT TERM...(THURSDAY THROUGH FRIDAY NIGHT)
ISSUED AT 306 AM EDT WED AUG 12 2015
HIGH IMPACT WEATHER POTENTIAL: STILL MONITORING THUNDERSTORM AND
LOCALLY HEAVY RAIN POTENTIAL TO END THE WORK WEEK.
PATTERN SYNOPSIS/ANTICIPATED EVOLUTION: ONE RATHER MERIDIONAL FLOW
REGIME ACROSS THE CONUS...CONSISTING OF WESTERN/HIGH PLAINS RIDGE
AND EASTERN TROUGH...EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THIS WORK WEEK. NORTHERN MICHIGAN WILL REMAIN SQUARELY UNDER THE
INFLUENCE OF THE LATTER...WITH REINFORCING WAVES AND THEIR ATTENDANT
FRONTAL FEATURES BRINGING SOME SHOWER AND THUNDERSTORM THREAT
THURSDAY INTO FRIDAY. EXCELLENT INTER/INTRA MODEL AGREEMENT FOR A
RATHER SUBSTANTIAL PATTERN SHIFT HEADING INTO THE WEEKEND AND THE
START OF NEXT WEEK...WITH NORTHERN EXTENT OF UPSTREAM RIDGING
FOLDING OVER AND ACROSS THE NORTHERN LAKES...EVENTUALLY SETTING UP A
MUCH MORE ZONAL FLAVOR TO THE FLOW PATTERN ACROSS THE NORTHERN CONUS.
PRIMARY FORECAST CONCERNS/CHALLENGES: EVOLUTION OF SHOWER AND
THUNDERSTORM CHANCES THURSDAY THROUGH FRIDAY.
DETAILS: A CHALLENGING FORECAST SETTING UP FOR THURSDAY AS SOUTHWARD
RETREAT OF WHAT WAS ONCE OVERHEAD SURFACE HIGH PRESSURE
CONTINUES...ALLOWING A WEAK WARM FRONT TO SWEEP ACROSS THE AREA.
FRONT ITSELF DOES NOT LOOK ALL THAT ACTIVE...WITH LITTLE DEEP LAYER
SUPPORT. INCREASINGLY WARM/HUMID AIRMASS AND PASSING OF SUBTLE MID
LEVEL WAVE MAY ALLOW A FEW AFTERNOON SHOWERS AND STORMS TO
FIRE...ALTHOUGH STILL BELIEVE BETTER ACTIVITY WILL WAIT UNTIL THE
OVERNIGHT HOURS WHEN SOUTHEAST DROPPING CANADIAN COLD FRONT BEGINS
TO ENTER THE PICTURE. WHILE OVERNIGHT TIMING SHOULD HELP TO PREVENT
MUCH OF A SEVERE WEATHER THREAT...0-6KM BULK SHEAR OF UP TO 30 KNOTS
DOES SUPPORT AT LEAST SOME STORM ORGANIZATION.
COLD FRONT EXPECTED TO ONLY MAKE SLOW PROGRESS SOUTH ACROSS THE AREA
FRIDAY AS PARENT LOW PRESSURE IS WELL REMOVED TO THE NORTH. PER THE
USUAL...DAYTIME HEATING WILL ONLY FURTHER HINDER THE FRONTAL
ADVANCEMENT...ALTHOUGH SUSPECT SPEED TO BE AT LEAST PARTIALLY
DICTATED BY ANY SHOWER AND STORM PRODUCED OUTFLOWS. STILL LIKE THE
IDEA OF KEEPING THE BETTER CHANCES FOR ADDITIONAL SHOWERS AND
THUNDERSTORMS SOUTH OF THE BRIDGE...PARTICULARLY SOUTH OF M-32. WHILE
NOT EXTREME...PRECIPITABLE WATERS AROUND AN INCH AND A HALF AND
POSSIBILITY FOR AT LEAST A COUPLE ROUNDS OF STORMS DEFINITELY
SUPPORTS SOME LOCALLY HEAVY RAIN. WILL CONTINUE TO HIGHLIGHT THIS
POTENTIAL IN OUR LATEST HAZARDOUS WEATHER PRODUCTS.
&&
.LONG TERM...(SATURDAY THROUGH TUESDAY)
ISSUED AT 306 AM EDT WED AUG 12 2015
AS MENTIONED EARLIER...SOME RATHER SIGNIFICANT CHANGES TO THE
LONG WAVE PATTERN SET TO TAKE SHAPE TO START THE WEEKEND. STRONG
ENERGY PUNCHING INTO THE CANADA WEST COAST AND EASTWARD PUNT OF
CURRENT WEST COAST CUTOFF LOW HELP SET THESE CHANGES IN
MOTION...WORKING IN TANDEM TO FORCE NORTHERN EXTENT OF SUBTROPICAL
RIDGE TO FOLD OVER INTO THE NORTHERN LAKES. PATTERN SET TO BECOME
TEMPORARILY MORE ZONAL INTO THE START OF NEXT WEEK AS NORTHERN
EXTENT OF RIDGING IS SHUNTED OFF THE EAST COAST. THE WEEKEND
CONTINUES TO LOOK DRY AND RATHER WARM...WITH TEMPERATURES AT LEAST
SEVERAL DEGREES ABOVE NORMAL. NOT OUT OF THE REALM OF POSSIBILITY
A FEW OF THE TRADITIONAL WARMER LOCALES MAKE A RUN AT 90 DEGREES
BY SUNDAY. NEXT STRETCH OF ACTIVE WEATHER (AT LEAST POTENTIALLY)
ARRIVES SUNDAY NIGHT THROUGH TUESDAY AS WARM/MOIST AIRMASS IS
WORKED OVER BY APPROACHING WAVES AND HINTS OF A SLOW MOVING COLD
FRONT. OF COURSE...PLENTY OF TIME FOR THIS TO ALL CHANGE...SO
INHERITED CHANCY POPS MORE THAN FINE FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 131 PM EDT WED AUG 12 2015
DIURNAL CU HAS FORMED AROUND N MICHIGAN AND WITH THE DRIER AIR
OVER THE REGION THAN YESTERDAY, WE MAINLY HAVE VFR CIGS IF THERE
ARE ANY CIGS AT ALL. THE MAIN WEATHER TO WATCH FOR IS THE
THUNDERSTORMS COMING OUT OF SE MANITOBA THAT WILL ARRIVE
OVERNIGHT, INTO UPPER MICHIGAN AROUND 12Z. THE INITIAL IDEA WILL
BE FOR THE THUNDERSTORMS TO MOVE INTO THE TIP OF THE MIT AND INTO
NE LOWER DURING THE MORNING. WILL PROBABLY HAVE TO AMEND FOR THIS
PRIOR TO THE NEXT TAF ISSUANCE.
&&
.MARINE...
ISSUED AT 306 AM EDT WED AUG 12 2015
NW WINDS WILL CONTINUE TODAY...THOUGH WEAKER/LESS GUSTY THAN
TUESDAY. A WARM FRONT WILL MOVE EAST INTO NORTHERN MI
TONIGHT...PERHAPS BRINGING SHOWERS/STORMS TO NORTHERN LAKE MI.
SOUTHWEST WINDS WILL SEEN ON THURSDAY BEHIND THE WARM
FRONT...THOUGH AGAIN THESE WILL NOT BE PARTICULARLY STRONG. SMALL
CRAFT ADVISORIES ARE NOT EXPECTED TO BE NEEDED.
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JSL
NEAR TERM...JAZ
SHORT TERM...MSB
LONG TERM...MSB
AVIATION...JSL
MARINE...JAZ
AREA FORECAST DISCUSSION
NWS DULUTH MN
1253 PM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 1243 PM CDT WED AUG 12 2015
UPDATED AVIATION SECTION BELOW.
UPDATE ISSUED AT 901 AM CDT WED AUG 12 2015
UPDATED THE FORECAST TO INCREASE THE HIGH TEMPERATURES AND WIND
SPEEDS AND GUSTS FOR TODAY. THE FOCUS FOR INCREASING THE
TEMPERATURES WAS FOR NEAR THE TWIN PORTS. THINK THE SUNNY
SKIES AND WARM AND GUSTY SW WINDS TODAY WILL BE A GOOD RECIPE FOR
WARMING TODAY...SO WANTED TO LEAN ON THE WARMER
GFSMOS/SREFBC/RAP13BC MODEL GUIDANCE. DOWNSLOPE WARMING SHOULD
ALSO ALLOW TEMPERATURES NEAR THE TWIN PORTS SHORELINE...INCLUDING
PARK POINT...TO WARM UP INTO THE UPPER 80S. INCREASED THE PARK
POINT FORECAST FROM THE EARLIER FORECAST OF ABOUT 81 TO NOW 87.
THE RAP13/NAM12 MODEL SOUNDINGS SUGGEST THERE COULD BE GUSTS TO
AROUND 20 MPH OVER MUCH OF THE FORECAST AREA BY LATER THIS
AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
SUMMER HEAT RETURNS WITH SOME OF THE WARMEST WEATHER OF THE SUMMER
SO FAR TODAY AND TOMORROW. MORNING SHOWERS AND MAYBE A THUNDERSTORM
ACROSS THE TIP OF THE MINNESOTA ARROWHEAD THIS MORNING...BUT
OTHERWISE MOSTLY SUNNY THIS AFTERNOON WITH A BREEZY SOUTHWEST WIND.
TONIGHT ISOLATED TO SCATTERED THUNDERSTORMS WILL MOVE SOUTHEAST
ACROSS THE AREA WITH THE POSSIBILITY FOR A FEW STORMS TO BECOME
STRONG TO SEVERE. THURSDAY WILL BE THE HOTTEST DAY OF THE FORECAST
WITH HIGHS IN THE UPPER 80S TO LOW 90S AND THE POSSIBILITY FOR
ISOLATED STORMS.
ON THE SYNOPTIC SCALE A FAIRLY TYPICAL SUMMER PATTERN WITH AN UPPER
LEVEL RIDGE AXIS ALONG THE HIGH PLAINS AND A RESULTING NORTHWEST
FLOW ALOFT LOCALLY. THIS MORNING AN ELEVATED WARM FRONT IS MOVING
ACROSS FAR NORTHEAST MINNESOTA AND IT MOVES SOUTHEAST ACROSS SW
ONTARIO AND ACROSS WESTERN LAKE SUPERIOR...RESULTING IN SOME
ISOLATED SHOWERS AND STORMS. THE BROAD AREA OF HIGH PRESSURE OVER
THE AREA YESTERDAY HAS MOVED SOUTH INTO THE MID-MISSISSIPPI TO OHIO
VALLEY...WHICH WILL RESULT IN SOUTHWEST FLOW AT LOW LEVELS AND
CAUSE 850MB TEMPS TO SURGE 4-8 DEG CELSIUS TODAY. THIS WILL ALSO
INCREASE LOW LEVEL MOISTURE RESULTING IN DEW POINTS HEADING INTO THE
LOW TO MID 60S BY TONIGHT. THIS WILL ALL BE AHEAD OF A WEAK
FRONT/TROUGH THAT IS EXPECT TO BE THE FOCUS FOR STORM INITIATION
ACROSS SOUTHERN MANITOBA AND FAR NORTHEAST NORTH DAKOTA LATE TODAY
WITH STORMS MOVING INTO NORTHERN MINNESOTA TONIGHT. WHILE ONLY A
SUBTLY MID-LEVEL SHORTWAVE EXISTS AT 500MB...A 80-100 KT 300MB JET
STREAK ALOFT WILL PROVIDE RESULT IN DIVERGENCE ALOFT ACROSS
NORTHEAST MINNESOTA TONIGHT AND THUS PROVIDE SOME LARGE-SCALE
LIFT...NOT TO MENTION THE FASTER WINDS ALOFT WILL RESULT IN BETTER
DEEP LAYER SHEAR FOR STORMS TO SUSTAIN INTO THE NIGHT. ON THURSDAY
ANOTHER ELEVATED TROUGH/FRONT WILL MOVE THROUGH FROM THE
NORTHWEST...BUT CAP WILL LIKELY LIMIT COVERAGE OF STORMS.
EARLY THIS MORNING...PATCHY FOG WITH SHOWERS ACROSS THE TIP OF THE
ARROWHEAD. RAP SEEMED TO HAVE A GOOD HANDLE ON THE FOG DEVELOPMENT
WITH THE LOWEST VISIBILITIES DEVELOPING ACROSS NORTHEAST
WISCONSIN...WITH FOG EXPECTED TO BURN OFF JUST AFTER SUNRISE. USED
JUST SHOWERS WORDING IN THE FORECAST FOR THE ARROWHEAD GIVEN LACK OF
INSTABILITY EARLY THIS MORNING...BUT ADD IN ISOLATED THUNDER TOWARDS
MID-MORNING. OTHERWISE CLEAR SKIES AND TEMPS FALLING TO THE MID 50S
OR COOLER IN A FEW SPOTS.
THIS AFTERNOON...HOT AND SUNNY. BREEZY...SOUTHWEST WINDS GUSTING TO
20-25 MPH AT TIMES DUE TO DEEP MIXING. HIGHS IN THE LOW 80S OVER
NORTHWEST WISCONSIN AND THE ARROWHEAD...INTO THE MID TO UPPER 80S
ELSEWHERE INCLUDING THE TWIN PORTS. INCREASING CLOUDS ALONG THE
INTERNATIONAL BORDER LATE IN THE DAY.
TONIGHT...ISOLATED TO SCATTERED SHOWERS AND STORMS MOVING FROM
NORTHWEST TO SOUTHEAST ACROSS NORTHEAST MINNESOTA INTO NORTHWEST
WISCONSIN. WITH MUCAPE VALUES 1500-2000 J/KG AND DEEP LAYER SHEAR
AROUND 40-50KTS STRONG TO SEVERE STORMS ARE LIKELY IF STORMS DO
DEVELOP. THESE STORMS ARE EXPECTED TO BE ELEVATED....BUT IT SHOULD
BE NOTED 0-3KM HELICITY OF 300-400 M2/S2 ACROSS NORTH-CENTRAL
MINNESOTA AROUND 00-04 UTC THIS EVENING WHICH WOULD RESULT IN
ROTATING STORMS...BUT THE HIGH LCL HEIGHTS SHOULD PRECLUDE A
TORNADIC RISK. STILL...SOMETHING TO MONITOR. OTHERWISE THE NORMAL
HAIL/WIND/HEAVY RAINFALL THREATS WITH STORMS EXPECTED TO MOVE ACROSS
NORTHEAST MINNESOTA THROUGH MIDNIGHT AND ROLL INTO NORTHWEST
WISCONSIN IN THE EARLY MORNING HOURS. AGREE WITH INITIAL DAY ONE SPC
OUTLOOK WITH A MARGINAL RISK FOR MUCH OF THE NORTHLAND...BUT THIS
MAY NEED TO BE REEVALUATED FOR AN UPGRADE THIS AFTERNOON DEPENDING ON
HOW CONDITIONS EVOLVE.
THURSDAY...SOME UNCERTAINTY AS TO PRECIPITATION BUT NOT WHEN IT
COMES TO THE HEAT AND HUMIDITY...IT IS GOING TO BE A HOT ONE OUT
THERE. MOST GUIDANCE DEPICTING ANOTHER TROUGH/FRONT MOVING THROUGH
IN THE AFTERNOON...BUT BASED ON MODEL SOUNDINGS THINK CAP MIGHT BE
STRONG ENOUGH TO PREVENT WIDESPREAD STORMS. IF STORMS DO
DEVELOP...EXPECT RAPID DEVELOPMENT DUE TO MUCAPE IN EXCESS OF 2000
J/KG AND WITH 0-6KM SHEAR IN THE 25 TO 35 KT RANGE COULD SEE STORMS
SUSTAIN FOR A FEW HOURS. HIGHS IN THE MID 80S ACROSS NORTHWEST
WISCONSIN...IN THE UPPER 80S TO LOW 90S ACROSS NORTHEAST MINNESOTA
EXCEPT FOR THE TIP OF THE ARROWHEAD.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 AM CDT WED AUG 12 2015
A COLD FRONT WILL CONTINUE SOUTH THROUGH THE NORTHLAND THURSDAY
NIGHT WITH HIGH PRESSURE BUILDING IN DURING THE DAY FRIDAY. WE
LINGER CHANCES FOR SHOWERS/STORMS THURSDAY NIGHT OVER THE EASTERN
TWO THIRDS OF THE CWA THEN WENT DRY FOR MOST AREAS ON FRIDAY UNDER
THE HIGH. HIGHS FRIDAY WILL BE IN THE MIDDLE 80S.
THE HIGH WILL MOVE OFF TO THE EAST SATURDAY WITH ANOTHER COLD FRONT
OVER THE NORTHERN PLAINS PROGRESSING EAST. IT SHOULD BE VERY WARM
AND DRY SATURDAY WITH HIGHS IN THE 80S.
THE FRONT WILL CONTINUE EAST SATURDAY NIGHT INTO SUNDAY. THERE ARE
SOME TIMING DIFFERENCES BETWEEN THE GFS/ECMWF...WITH THE GFS FASTER.
THERE WILL BE A CHANCE FOR SHOWERS/STORMS SATURDAY NIGHT/SUNDAY WITH
THIS FRONT. AT THIS POINT...THE INSTABILITY IS NOT REAL IMPRESSIVE.
HOWEVER...THERE WILL BE A GOOD SOUTH/SOUTHWEST FLOW AHEAD OF THE
FRONT AS SEEN WITH 850MB WINDS 40-50KT AND GOOD LOW LEVEL
CONVERGENCE WITH THE FRONT. SOME STRONG STORMS WILL BE POSSIBLE.
THE MODELS DIVERGE MONDAY INTO MID WEEK WITH SOME FAIRLY LARGE
DIFFERENCES. AT THIS POINT WE HAVE LOW POPS THROUGH THAT PERIOD.
HIGHS MONDAY/TUESDAY WILL BE COOLER WITH HIGHS IN THE LOWER TO
MID 70S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1243 PM CDT WED AUG 12 2015
CONVECTIVE TRENDS THE MAIN CONCERN FOR THIS TAF CYCLE...WITH
OTHERWISE VFR CONDITIONS EXPECTED. AS OF 1730Z...AN AREA OF
THUNDERSTORMS OVER SOUTHEAST MANITOBA IS MOVING SOUTHEAST TOWARDS
THE TERMINALS. THESE STORMS ARE MOVING INTO A LESS UNSTABLE
AIRMASS...AND THEY MAY DECAY. IF THIS HAPPENS WE WILL HAVE TO WAIT
FOR MORE CONVECTION TO DEVELOP OVER SOUTHERN MANITOBA IN THE NEXT
SEVERAL HOURS BEFORE IT CAN MOVE SOUTHEAST TO AFFECT THE
TERMINALS. HOWEVER...IF THE STORMS MAINTAIN...WE COULD HAVE
CONVECTION INTO KINL AS EARLY AS 21Z. HAVE HAD TO DO SOME HEDGING
IN THE TERMINALS UNTIL TRENDS BECOME BETTER DEFINED...AND
ANTICIPATE UPDATES IN THE NEXT 2-4 HOURS. OTHERWISE SOUTH-
SOUTHWEST WINDS GENERALLY AROUND 10 KTS TO CONTINUE UNTIL A WEAK
TROUGH AXIS PASSES AND WINDS TURN TO THE NORTHWEST AT LESS THAN 10
KTS BY 15Z THURSDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 87 65 90 65 / 0 30 20 30
INL 89 61 88 59 / 30 50 20 10
BRD 86 66 90 65 / 10 20 10 10
HYR 84 63 86 63 / 0 30 30 20
ASX 86 64 88 62 / 10 40 20 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...NONE.
&&
$$
UPDATE...LE
SHORT TERM...JJM
LONG TERM...MELDE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
924 AM PDT WED AUG 12 2015
.UPDATE...
SHOWERS CONTINUE TO DISSAPATE OVER MOHAVE COUNTY THIS MORNING.
OTHERWISE...MID AND HIGH LEVEL CLOUDS CONTINUE TO STREAM NORTHWARD
ACROSS THE AREA WITH ENOUGH BREAKS TO PREVENT NOTABLE INHIBITION OF
DAYTIME HEATING. MOISTURE IS IN PLACE AT LOWER AND MID LEVELS AND
INCREASING INSTABILITY WITH DAYTIME HEATING...THUNDERSTORMS ARE
EXPECTED FROM FAR EASTERN SAN BERNARDINO COUNTY TO MOHAVE
COUNTY...AND AS FAR NORTH AS LINCOLN COUNTY TODAY. MORNING PWAT
VALUES ON THE VEF RAOB WERE OBSERVED AT 1.43 INCHES...WITH THE
CURRENT MESO-ANALYSIS SUPPORTING 1.25-1.5 VALUES ACROSS TODAYS AREA
OF CONCERN. SB CAPE VALUES ARE FORECAST TO INCREASE OER THE NEXT FEW
HOURS...RANGING FROM 1000-1500 J/KG BY 19Z. THE LACK OF UPPER LEVEL
FORCING TODAY MEANS THAT THUNDERSTORMS WILL INITIATE OVER AREAS OF
HIGHER TERRAIN INITIALLY BEFORE MOVING OFF TO THE NORTH-NORTHEAST AS
850-300MB STEERING FLOW IS OUT OF THE SOUTH-SOUTHWEST AT 10-15 KTS.
EXPECT OUTFLOW BOUNDARIES TO BECOME A FOCAL POINT FOR ADDITIONAL
THUNDERSTORM DEVELOPMENT LATER THIS AFTERNOON. THE LATEST RUNS OF
LOCAL HI-RES MODELS...AS WELL AS THE HRRR SUPPORT THIS
ANALYSIS...WITH INITIATION PROGGED FOR 19Z.
&&
.PREV DISCUSSION... /ISSUED 243 AM PDT WED AUG 12 2015/
.SYNOPSIS...THE PRIMARY AREAS FOR THUNDERSTORM ACTIVITY TODAY WILL
BE IN MOHAVE...FAR EASTERN SAN BERNARDINO...CLARK...AND LINCOLN
COUNTIES. A FEW STORMS MAY REACH AS FAR WEST AS NYE AND THE CENTRAL
PORTIONS OF SAN BERNARDINO COUNTY AS WELL. LINGERING MOISTURE COULD
LEAD TO A FEW STORMS BOTH THURSDAY AND FRIDAY ALTHOUGH CONDITIONS
SHOULD BECOME WARMER AND DRIER. A HOT WEEKEND IS EXPECTED WITH
HIGH TEMPERATURES 5 OR MORE DEGREES ABOVE NORMAL.
&&
.SHORT TERM...TODAY THROUGH FRIDAY.
SATELLITE SHOWS EXTENSIVE MID AND HIGH CLOUD COVER OVER THE EASTERN
HALF OF THE AREA THIS MORNING WITH RADAR SHOWING LIGHT SHOWER
ACTIVITY IN PORTIONS OF MOHAVE AND NE CLARK COUNTIES. ONLY LIGHT
RAINFALL AMOUNTS HAVE BEEN MEASURED SO FAR THIS MORNING (UNDER
.10 INCHES). THE PRIME AREA OF CONCERN FOR SHOWER/THUNDERSTORM
ACTIVITY TODAY WILL BE MOHAVE, LINCOLN, CLARK AND FAR EASTERN SAN
BERNARDINO COUNTIES WHERE MODELS FORECAST THE BEST MOISTURE AND
INSTABILITY. HOWEVER, A FEW STORMS MAY FORM A BIT FURTHER WEST ALONG
THE MOISTURE BOUNDARY IN EASTERN NYE AND CENTRAL SAN BERNARDINO
COUNTIES AS WELL. WITH THE OVERNIGHT FOCUSING MECHANISM LIFTING INTO
UTAH THIS MORNING AND NO DISCERNIBLE FEATURE TO AIDE IN LIFT DURING
THE DAY OTHER THAN DAYTIME HEATING, WILL FOREGO ISSUING A FLASH
FLOOD WATCH SINCE FLASH FLOODING COULD BE MORE LOCALIZED.
HIGH PRESSURE EAST OF THE AREA COUPLED WITH LOW PRESSURE ALONG THE
COAST WILL CONTINUE TO CHANNEL MOISTURE INTO THE REGION TONIGHT AND
INTO THURSDAY FOR CONTINUED CHANCES OF SHOWERS AND STORMS. THE LOW
IS FORECAST TO FINALLY LIFT INTO THE PACIFIC NORTHWEST FRIDAY,
ALLOWING HIGH PRESSURE TO BUILD FURTHER WEST. HOWEVER, THE UPPER
LEVEL FLOW REMAINS FAVORABLE AND THE DOOR REMAINS OPEN FOR MOISTURE
IMPORT VIA ANY CURRENTLY UN-RESOLVED DISTURBANCE SUCH AS AN MSV OR
INVERTED TROUGH TO OUR SOUTHEAST. WE ARE CURRENTLY ONLY CALLING FOR
A SLIGHT CHANCE OF THUNDERSTORMS FRIDAY ALTHOUGH THIS MAY NEED TO BE
ADJUSTED IF MOISTURE OVER THE AREA DOES NOT FLUSH OUT AND THE AREA
REMAINS MOIST AND WEAKLY UNSTABLE.
TEMPERATURES SHOULD BE SEVERAL DEGREES BELOW NORMAL TODAY BUT THEN
WARM TO NEAR OR SLIGHTLY ABOVE NORMAL THURSDAY. FRIDAY BEGINS THE
BIG WARMUP INTO THE WEEKEND ALTHOUGH LINGERING MOISTURE MAY HOLD
HIGH TEMPERATURES BELOW CURRENT FORECASTED HIGHS.
.LONG TERM...SATURDAY THROUGH TUESDAY.
AS HAS BEEN MENTIONED BY PREVIOUS SHIFTS...THE BIGGEST CONCERN
OVER THE WEEKEND WILL BE HEAT. THE MODEL GUIDANCE SPREAD IS
SHRINKING...WITH THE GFS MOS SHOWING 108/108 FOR KLAS SATURDAY AND
SUNDAY WHILE THE ECMWF MOS SHOWS 110/112. OFFICIAL FORECAST IS IN
BETWEEN AT 109/109...WHICH IS RIGHT UP AGAINST THE EXCESSIVE HEAT
WARNING CRITERION OF 110. AFTER SOME DISCUSSION...DECIDED TO DEFER
THE POSSIBILITY OF AN EXCESSIVE HEAT WATCH TO THE DAY CREW. THERE
IS REASONABLE MODEL AGREEMENT THAT THE BIG HOT RIDGE WILL
MOVE/REFORM TO THE SOUTHWEST...TURNING THE MID LEVEL FLOW TO
WESTERLY OR NORTHWESTERLY BY MONDAY...WHICH WILL SERVE TO SCOUR
OUT ANY LINGERING MOISTURE AND KNOCK HIGH TEMPS DOWN A COUPLE OF
DEGREES. SO IF THE MODEL TRENDS ARE CORRECT IT WILL NOT BE A
PROLONGED HEAT EVENT. BUT ANY SUCH EVENT WHICH PEAKS ON THE
WEEKEND ALWAYS CAUSES CONCERN. STAY TUNED. &&
.AVIATION...FOR MCCARRAN...NORTH WINDS UP TO 8KTS ARE EXPECTED TO
BECOME LIGHT AND VARIABLE AFTER 13Z THEN FAVOR A SOUTHEAST DIRECTION
THIS AFTERNOON. THUNDERSTORM CHANCES ARE BETTER TODAY IN AND AROUND
THE LAS VEGAS VALLEY SO THERE COULD BE MORE IMPACTS AT THE TERMINAL
THROUGH THE DAY IN THE FORM OF ERRATIC...GUSTY WINDS AND BRIEFLY
LOWERED CIGS. OTHERWISE, CLOUD COVER SHOULD BE MAINLY A0A 10K FEET.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...SCT-BKN CLOUD COVER AND A CHANCE OF THUNDERSTORMS TODAY
ACROSS THE CENTRAL AND EASTERN REGIONS OF THE AREA. STORMS COULD
BRING BRIEF HEAVY RAIN AND GUSTY WINDS TO AIRPORT TERMINALS IN CLARK
COUNTY AND ALONG THE COLORADO RIVER VALLEY. MOUNTAIN OBSCURATIONS
ARE POSSIBLE WITH ANY THUNDERSTORMS THAT DEVELOP.
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
$$
UPDATE...PULLIN
SHORT TERM/AVIATION...SALMEN
LONG TERM...MORGAN
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
301 PM EDT WED AUG 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN THROUGH FRIDAY. A COASTAL TROUGH
OF LOW PRESSURE WILL DRIFT TOWARDS THE AREA OVER THE WEEKEND.
HIGH PRESSURE WILL LINGER OVERHEAD EARLY NEXT WEEK WITH THE
POTENTIAL FOR AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...VERY FEW SHOWERS HAVE TRIED TO MATERIALIZE
TODAY. A FEW HOURS AGO THIS OCCURRED IN FAR EASTERN BRUNSWICK
COUNTY AND NOW THEY ARE TRYING TO PERCOLATE NEAR SOUTHPORT. THE
END RESULT APPEARS TO BE THE SAME BOTH TIMES...NON- MEASURABLE
SPRINKLES THAT THEN SUCCUMB TO THE IMPRESSIVELY DRY AIR THAT
CONTINUES TO SEEP INTO THE AREA. DESPITE THIS I HAVE LEFT THE
20-ISH POPS ALONG THE COAST SINCE THE HIGHER REFRESH MODELS LIKE
THE HRRR AND RAP CONTINUE TO LIKE THE IDEA OF SEA BREEZE
PRECIPITATION ESPECIALLY OVER SOUTH CAROLINA AND THE CU FIELDS
SEEM TO INCREASE IN VIGOR ESPECIALLY ALONG THE SEA BREEZE FRONT. A
FACET OF THE FORECAST THAT IS OF SLIGHTLY ELEVATED INTEREST
TONIGHT IS CLOUD COVER SINCE THE PERSEID METEOR SHOWER PEAKS.
VIEWING FOR THE METEORS WILL NOT BE TERRIBLE BY ANY MEANS BUT A
PARTLY CLOUDY SKY FOR MOST IF NOT ALL OF THE OVERNIGHT MEANS THEY
SIMPLY WON`T BE IDEAL. THIS MAY HOLD TRUE MORE EARLIER RATHER THAN
LATER DEPENDING ON HOW QUICKLY THE CLOUDS DISSIPATE. AT LEAST THE
MOON WILL BE COOPERATIVE...ITS PHASE WILL BE A MERE SLIVER THAT
WON`T EVEN RISE TIL AFTER 4 AM. SLIGHTLY LOWER DEWPOINTS INLAND
COULD MEAN CLEARER SKIES OVER FAR INLAND ZONES.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THURSDAY WILL BEGIN WITH A MID-LEVEL
TROUGH AXIS ALIGNED ACROSS THE CENTRAL CAROLINAS AND THE SWATH OF
DEEPEST MOISTURE OFFSHORE. THE CENTER OF A WEAK SURFACE HIGH WILL
SHIFT EASTWARD ACROSS THE MID-ATLANTIC STATES ALLOWING WINDS TO
VEER FROM NORTH-NORTHEAST TO EAST BY THURSDAY AFTERNOON. MODEL
TIME-HEIGHT CROSS SECTIONS DO SHOW ENOUGH MOISTURE LINGERING BELOW
700 MB TO SUPPORT AN ISOLATED SHOWER OR THUNDERSTORM
THURSDAY...HOWEVER SURFACE-BASED INSTABILITY WILL BE MINIMAL.
THINK THE CHANCE IS TOO SMALL TO WARRANT INCLUSION AT THIS TIME.
INSTABILITY WILL BE A LITTLE MORE FAVORABLE FOR CONVECTION ON
FRIDAY AFTERNOON GENERALLY SOUTH AND EAST OF A FLORENCE TO BURGAW
LINE SO WILL MAINTAIN THE SLIGHT CHANCE POP THERE. THE MID-LEVEL
TROUGH WILL WEAKEN LATE IN THE PERIOD. THIS WILL ALLOW THE DEEPER
MOISTURE AND INVERTED TROUGH OFFSHORE TO SHIFT BACK TOWARDS THE
COAST FRIDAY NIGHT AND WARRANTS THE INCLUSION OF LOW POPS ACROSS
THE COASTAL COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 3 PM WEDNESDAY...H5 PATTERN INDICATES A WEAK TROUGH ACROSS
THE SE THROUGH THE WEEKEND WITH A STATIONARY BOUNDARY OFF THE SE
COAST. THIS BOUNDARY WILL HAVE A FEW WEAK WAVES OF LOW PRESSURE
FORM AND MOVE ALONG THIS BOUNDARY OFF THE COAST THIS WEEKEND.
GFS/ECMWF KEEP A CHANCE OF POPS ACROSS THE CWA AT TIMES SO WILL
INTRODUCE CHANCE POPS FOR THE WEEKEND. WITH SOME MID LEVEL FORCING
AND THE INTERACTION WITH THE AFTERNOON SEA BREEZE SOME ISOLATED TO
SCATTERED CONVECTION IS POSSIBLE BOTH DAYS. AS THE NEXT WEEK
BEGINS WITH THE DEVELOPMENT OF A TROUGH ACROSS THE SE WHICH BRINGS
A RETURN FLOW OF MOISTURE INTO THE REGION ALONG WITH AN INCREASED
CHANCE OF POPS FOR MONDAY AND TUESDAY AFTERNOONS WITH A GREATER
LIKELIHOOD OR POPS ON WEDNESDAY WITH AN AREA OF LOW PRESSURE
DEVELOPING ACROSS THE GULF COAST STATES AND MOVING TOWARDS THE
CAROLINAS. WILL INTRODUCE A BETTER CHANCE OF POPS FOR WED.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...EXCEPT FOR A SLIGHT CHANCE OF MVFR CIGS NEAR THE COASTAL
TERMINALS OVER THE NEXT SEVERAL HOURS ALONG A DEVELOPING SEA BREEZE
THERE IS HIGH CONFIDENCE VFR WILL CONTINUE AT ALL TERMINALS THROUGH
THIS EVENING. WINDS WILL BE NE...EXCEPT BECOMING SE AT THE COASTAL
TERMINALS AS THE SEA BREEZE SHIFTS INLAND. SHOWERS WILL CONTINUE
TO BE POSSIBLE JUST INLAND OF THE COASTAL TERMINALS ALONG THE
BOUNDARY...BUT WITH DRIER AIR ALOFT AND ONLY WEAK LOW LEVEL
FORCING THESE SHOULD REMAIN ISOLATED AT BEST. THE GREATEST
COVERAGE SHOULD BE WELL SOUTH OF KMYR.
OVERNIGHT WITH LIGHT WINDS AND SCATTERED SKIES THERE IS A CHANCE OF
PATCHY FOG DEVELOPMENT. AFTER SUNRISE VFR EXPECTED WITH NE-E WINDS
BECOMING E-ESE BY LATE IN THE TAF PERIOD.
EXTENDED OUTLOOK...ISOLATED SHRA/TSRA POSSIBLE THURSDAY AND FRIDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 3 PM WEDNESDAY...VERY LIGHT SOUTH-SOUTHWESTERLY WINDS AHEAD
OF A WEAKENING COLD FRONT FOR MOST OF THE OVERNIGHT. LATE IN THE
PERIOD WHILST SPEEDS REMAIN SIMILARLY LIGHT THERE COULD BE A BACKING
OF THE FLOW AS THE BOUNDARY SINKS FURTHER SOUTH AND A WEAK PUSH OF
HIGH PRESSURE COMES IN FROM OUR NORTH. SEAS ALREADY JUST 2-2.5
FT...LIKELY SETTLING SLIGHTLY BELOW THE LATTER VALUE THROUGH THE
PERIOD.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 PM WEDNESDAY...THE CENTER OF SURFACE HIGH PRESSURE WILL
BUILD ACROSS THE MID-ATLANTIC STATES ON THURSDAY AND PUSH OFF THE
DELMARVA PENINSULA ON FRIDAY. A WEAK SURFACE TROUGH OFF THE GA
COAST THURSDAY IS EXPECTED TO SLOWLY DRIFT TOWARDS THE AREA
THROUGH THE PERIOD. THE RESULT WILL BE NORTHEAST WINDS BECOMING
EASTERLY THURSDAY AFTERNOON...BUT BACKING TO THE NORTHEAST AGAIN
THURSDAY NIGHT. SHOWER AND THUNDERSTORM ACTIVITY IS EXPECTED TO
REMAIN WELL OFFSHORE THURSDAY...BUT MAY DRIFT WESTWARD INTO THE
COASTAL WATERS LATE FRIDAY WITH THE APPROACH OF THE SURFACE
TROUGH.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 PM WEDNESDAY...CONDITIONS WILL CHANGE VERY LITTLE FOR THE
MARINE COMMUNITY FOR THE WEEKEND. WINDS WILL PRIMARILY BE OUT OF
THE NE WITH A SHIFT TO THE ESE BY THE END OF THE WEEKEND AND BECOME
MORE S TO SW DURING THE BEGINNING OF NEXT WEEK. EXPECT 10 KTS OR
LESS THROUGHOUT THE PERIOD WITH SEAS RUNNING 1-3 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...CRM
NEAR TERM...MBB
SHORT TERM...CRM
LONG TERM...MAC
AVIATION...MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
122 PM EDT WED AUG 12 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. A FEW SHOWERS
MAY DEVELOP LATER TODAY. HIGH PRESSURE WILL BUILD IN THURSDAY AND
FRIDAY WITH SEASONABLE TEMPERATURES. THE WEEKEND INTO EARLY NEXT
WEEK LOOKS TYPICAL WITH WARM TEMPERATURES AND A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY... WATER VAPOR IMAGERY MOST EFFECTIVELY AND
EFFICIENTLY TELLS THE STORM TODAY. DRY AIR NOW COVERING THE ENTIRE
REGION...DRIER IN FACT THAT SEEN IN A WHILE. THE SURFACE REMAINS
RATHER MOIST HOWEVER WITH DEWPOINTS STILL WITHIN A FEW DEGREES OF 70
AND HIGHEST ALONG THE COAST. THE FRONT TO OUR WEST IS A BIT HARD TO
PICK OUT AND THERE IS FAIR AGREEMENT BETWEEN RUC AND HRRR THAT
PRECIP IS ISOLATED AND GENERALLY ALONG THE IMMEDIATE COAST WHERE NOT
ONLY IS THERE THE MOST MOISTURE BUT ALSO THE SEA BREEZE WILL PROVIDE
THE ONLY REAL FORCING OF THE DAY.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 315 AM WEDNESDAY...THE MID LEVEL TROUGH WILL BE IN PLACE
THROUGH THE PERIOD ALTHOUGH IT WILL WEAKEN SOMEWHAT BY SATURDAY
MORNING. AT THE SURFACE HIGH PRESSURE WILL BE POSITIONED ALONG THE
APPALACHIANS AND BASICALLY REMAIN IN PLACE THROUGH SATURDAY AS
WELL. AN INVERTED TROUGH WILL DEVELOP OFFSHORE AS THE HIGH
WEAKENS. WILL KEEP POPS MINIMAL AS THESE FEATURE`S ALWAYS SEEM A
LITTLE OVERDONE BY GUIDANCE. TEMPERATURES WILL BE VERY PLEASANT
ALTHOUGH A LITTLE WARMER...ESPECIALLY FRIDAY THAN PREVIOUS
GUIDANCE.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 315 AM WEDNESDAY...A WEAKLY FORCED MID LEVEL PATTERN WILL EXIST
ACROSS THE SOUTHERN HALF OF THE U.S THROUGH THE PERIOD. IN
FACT...AN ELONGATED WEAK TROUGH WILL MEANDER ACROSS THE NORTHERN
GULF OF MEXICO. FOR THE EASTERN CAROLINAS...WEAK HIGH PRESSURE
WILL BE THE MAIN FEATURE. NO REAL FORCING MECHANISMS FOR ANY
ORGANIZED RAINFALL WITH THE SEA BREEZE BEING THE MAIN CATALYST.
EVEN THE PIEDMONT TROUGH APPEARS MUTED. THERE IS A HINT OF A WEAK
SHORTWAVE THAT MOVES ACROSS TUESDAY THAT MAY ENHANCE RAIN CHANCES
AND THIS IS WHERE THE HIGHEST POPS IN THE FORECAST RESIDE.
TEMPERATURES SHOULD BE SPOT ON CLIMATOLOGY.
&&
.AVIATION /18Z WEDNESDAY THROUGH SUNDAY/...
AS OF 18Z...EXCEPT FOR A SLIGHT CHANCE OF MVFR CIGS NEAR THE COASTAL
TERMINALS OVER THE NEXT SEVERAL HOURS ALONG A DEVELOPING SEA BREEZE
...THERE IS HIGH CONFIDENCE VFR WILL CONTINUE AT ALL TERMINALS
THROUGH THIS EVENING. WINDS WILL BE NE...EXCEPT BECOMING SE AT THE
COASTAL TERMINALS AS THE SEA BREEZE SHIFTS INLAND. SHOWERS WILL
CONTINUE TO BE POSSIBLE JUST INLAND OF THE COASTAL TERMINALS ALONG
THE BOUNDARY...BUT WITH DRIER AIR ALOFT AND ONLY WEAK LOW LEVEL
FORCING THESE SHOULD REMAIN ISOLATED AT BEST. THE GREATEST COVERAGE
SHOULD BE WELL SOUTH OF KMYR.
OVERNIGHT WITH LIGHT WINDS AND SCATTERED SKIES THERE IS A CHANCE OF
PATCHY FOG DEVELOPMENT. AFTER SUNRISE VFR EXPECTED WITH NE-E WINDS
BECOMING E-ESE BY LATE IN THE TAF PERIOD.
EXTENDED OUTLOOK...ISOLATED SHRA/TSRA POSSIBLE THURSDAY AND FRIDAY.
OTHERWISE EXPECT VFR.
&&
.MARINE... NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM WEDNESDAY...POORLY DEFINED COLD FRONT STILL
APPROACHING FROM THE NORTHWEST AND STILL SLATED TO STALL VERY NEAR
THE COASTLINE. THIS WILL KEEP WIND AND SEAS MINIMAL WITH SOME
VARIABILITY/UNCERTAINTY IN THE WIND DIRECTION FORECAST ESPECIALLY
AS IT MAY BE PRONE TO MESOSCALE/SEABREEZE FLUCTUATIONS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 315 AM WEDNESDAY...A RELATIVELY WEAK NORTHEASTERLY TO EASTERLY
FLOW WILL BE IN PLACE THROUGH THE PERIOD. THIS AS HIGH PRESSURE
REMAINS TO THE NORTHEAST NEAR THE APPALACHIANS. SPEEDS MAY PICK UP
SLIGHTLY TO JUST OVER TEN KNOTS OR SO FRIDAY AS A TROUGH OFFSHORE
INCREASES THE GRADIENT SLIGHTLY. SEAS WILL BE 1-3 FEET.
LONG TERM /SATURDAY THROUGH SATURDAY/...
AS OF 315 AM WEDNESDAY...CONDITIONS WILL CHANGE VERY LITTLE FOR THE
MARINE COMMUNITY FOR THE WEEKEND. THE PRESSURE PATTERN WILL BE WEAK
THUS THE WIND FORECAST DOESN`T HAVE ANYTHING MUCH OVER TEN KNOTS.
THE SYNOPTIC FLOW WILL SHIFT TO SOUTHEAST LATER SATURDAY AND
CONTINUE SUNDAY. SEAS WILL GENEROUSLY BE 1-3 FEET AND MOSTLY 1-2
FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...MBB
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MRR
MARINE...REK/SHK
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1251 PM CDT WED AUG 12 2015
.UPDATE...
ISSUED AT 1251 PM CDT WED AUG 12 2015
CANADIAN ELEVATED T-STORMS STILL ONGOING...BUT WEAKENING. MLCAPE
INCREASING...BUT CAP REMAINS STRONG. THE EXPERIMENTAL HRRR LIKELY
INDICATES THE MOST LIKELY SCENARIO FOR SEVERE POTENTIAL THIS
AFTERNOON AND EVENING...DISSIPATING THE CURRENT CANADIAN
ACTIVITY...THEN RE-DEVELOPING STORMS CLOSER TO 00Z. THE
EXPERIMENTAL HRRR HAS BEEN CONSISTENT INDICATING STRONG STORMS
ACROSS NW MN THIS EVENING (AND STRONG WIND GUSTS). EXPANDED THE T+
MENTION TO COVER MUCH OF THE SPC SLIGHT RISK AREA. 12Z NSSL-WRF
ALSO AGREES WITH THIS SOLUTION.
HEAT INDEX VALUES ACROSS MUCH OF EASTERN NORTH DAKOTA WILL BE
AROUND 100F FOR A FEW HOURS THIS AFTERNOON (ET LEADING TO DEW
POINTS UPPER 60S/LOW 70S). DURATION OF 100+F HEAT INDEX VALUES
NOT ENOUGH FOR A HEAT ADVISORY...BUT MAY ISSUE SOME SORT OF LESSER
STATEMENT.
UPDATE ISSUED AT 1011 AM CDT WED AUG 12 2015
WILL CONTINUE TO BE MONITORING THE SEVERE STORM POTENTIAL FOR THIS
AFTERNOON. AREA OF STORMS ACROSS SOUTHERN MANITOBA (LOCATED WITHIN
LEFT EXIT REGION OF AN UPPER JET STREAK) LIKELY WILL REMAIN ON
EDGE OF THE MID-LEVEL CAPPING AND/OR WEAKEN THIS MORNING. WILL OF
COURSE MONITOR AND ADJUST THE FORECAST IF NEEDED. MODEL SOUNDINGS
CONTINUE TO INDICATE CONVECTIVE TEMPS IN THE UPPER 90S...SO
CAPPING LIKELY AN ISSUE TODAY. MOST CAM GUIDANCE (SUCH AS THE
OPERATIONAL HRRR AND RAP) INDICATING SFC TEMPS THIS AFTERNOON ABOVE
100F WITH WIDESPREAD CONVECTION BY 21Z. THIS HAS BEEN A BIG FLAW
OF THESE SYSTEMS...AND WILL FOLLOW THE GUIDANCE THAT INDICATES SFC
TEMPS IN THE MID-90S (SUCH AS THE EXPERIMENTAL HRRR). LOW LEVEL
CONVERGENCE SHOULD BE STRONG ENOUGH TO INITIATE AT LEAST A FEW
STORMS CLOSER TO 00Z (ESPECIALLY NW MN...BUT COULD EXTEND INTO SE
ND DEPENDING ON LOCAL DEW POINTS). ANY STORM HAS THE POTENTIAL TO
BE SEVERE GIVEN THE EXPECTED BACKGROUND ENVIRONMENT. MORE OR LESS
AN INVERTED-V TYPE SOUNDING SO DAMAGING WIND GUSTS (AND SOME
LARGER HAIL) LIKELY THE MAIN THREAT. SPC DID UPGRADE TO A SLIGHT
RISK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 336 AM CDT WED AUG 12 2015
HOT TEMPS AND LATE AFTERNOON/EVENING THUNDERSTORM CHANCES
HIGHLIGHT THE SHORT TERM CONCERNS.
WHILE THE UPPER RIDGE WILL REMAIN CENTERED OVER THE ROCKIES
TODAY...WARMER 850 MB TEMPS WILL SPREAD INTO THE AREA...WITH AN
INCREASE OF ABOUT 3C OVER YESTERDAY. WITH INCREASINGLY BREEZY SW
WINDS AHEAD OF A SFC TROUGH/WEAK COLD FRONT...TEMPS SHOULD EASILY
CLIMB SEVERAL DEGREES HIGHER THAN YESTERDAY INTO THE UPPER 80S TO
MID 90S. RECORD HIGHS TODAY AT KFAR/KGFK ARE 101/98F
RESPECTIVELY...AND 96F AT NWS FGF. HEAT INDICES MAY REACH THE
UPPER 90S IN SOME SPOTS FOR A TIME THIS AFTERNOON.
THE AFOREMENTIONED SFC TROUGH WILL SHIFT INTO THE N RRV/DEVILS
LAKE BASIN BY LATE AFTERNOON. UPPER SUPPORT WILL BE LIMITED WITH
THE UPPER SHORTWAVE TROUGH PASSING EAST OF THE AREA...BUT
CONVERGENCE ALONG THE BOUNDARY MAY BE SUFFICIENT FOR
ISOLATED/WIDELY SCATTERED STORMS LATE TODAY INTO THE EVENING AS
CIN ERODES NEAR THE BOUNDARY. SPC HAS MAINTAINED A MARGINAL RISK
FOR SVR OVER FAR NE ND AND NW MN. GIVEN EXPECTED DEW POINTS WELL
INTO THE 60S AND STEEP LAPSE RATES...MLCAPE ABOVE 2500 OR 3000
J/KG IS EXPECTED WITH ~40 KTS OF DEEP SHEAR. THE VERY WARM...DEEP
WELL MIXED BOUNDARY LAYER SUGGESTS POTENTIAL FOR SEVERE WIND GUSTS
WITH HAIL POSSIBLE AS WELL (GIVEN THE INSTABILITY AND POTENTIAL
FOR SUPERCELLS). KEPT MAINLY SLIGHT/CHANCE POPS DUE TO THE
EXPECTED COVERAGE. STORMS SHOULD PROGRESS SOUTH AND EAST AND
LIKELY EXIT THE AREA BY LATE EVENING.
A WEAK SFC FLOW REGIME IS EXPECTED THURSDAY WITH SOME MODEL
DISCREPANCIES AS TO THE PLACEMENT OF A DIFFUSE BOUNDARY. IN
ADDITION...MODELS INDICATE AN UPPER WAVE ROTATING AROUND THE UPPER
RIDGE INTO THE N PLAINS. WITH LOW CONFIDENCE IN ANY CONVECTIVE
CHANCES...LARGELY MAINTAINED IDEA FROM PREVIOUS FORECAST WITH SOME
LOW POPS IN THE FAR SOUTH/WEST. THERMAL PROFILES REALLY DON/T
CHANGE MUCH...SO EXPECT ANOTHER VERY WARM DAY. HOWEVER...WILL HAVE
TO WATCH OUT FOR CLOUD COVER...WHICH COULD LIMIT TEMPS A BIT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 336 AM CDT WED AUG 12 2015
SFC HIGH PRESSURE WILL WORK INTO THE AREA THURSDAY
NIGHT/FRIDAY. ANOTHER HOT DAY IS IN STORE WITH HIGHS NEAR OR ABOVE
90 IN MOST AREAS. FRIDAY NIGHT WILL BE MILD AS WINDS BECOME
SOUTHERLY AHEAD OF LOW PRESSURE DEVELOPING TO THE WEST.
SATURDAY THROUGH TUESDAY...THE PATTERN BEGINS TO SHIFT AT THE START
OF THE PERIOD AS ALL MODELS ARE IN PRETTY GOOD AGREEMENT ON THE
RIDGE STARTING TO BREAK DOWN THANKS TO A SIGNIFICANT SHORTWAVE
MOVING INTO SOUTHERN CANADA...ALTHOUGH THERE ARE DIFFERENCES IN
TIMING. THE GFS IS FASTER THAN THE INTERNATIONAL MODELS...BUT STILL
HAS SOUTHERN WINDS FOR MUCH OF THE DAY ON SATURDAY AHEAD OF THE SFC
TROUGH AXIS AND COLD FRONT. WILL CONTINUE TO KEEP SATURDAY
HOT...WITH PRECIP MOSTLY IN THE WEST AND THEN ACROSS THE ENTIRE CWA
SATURDAY NIGHT AS THE COLD FRONT MOVES THROUGH. SUNDAY AND INTO THE
EARLY PART OF NEXT WEEK SHOULD SEE TEMPS BELOW SEASONAL AVERAGES AS
THE COOL AIR MASS SETTLES IN BEHIND THE FRONT. THE GFS BRINGS A WEAK
SHORTWAVE JUST SOUTH OF THE CWA MONDAY AND CLIPS THE AREA NEAR THE
SD BORDER WITH PRECIP. NOT OUT OF THE QUESTION...SO WILL KEEP THE
LOW POPS THAT THE BLENDED SOLUTION GIVES US BUT THINK THE MAIN
PRECIP CHANCES WILL BE MORE TOWARDS MID WEEK AS THE NEXT STRONG
TROUGH MOVES OUT INTO THE PLAINS. FLOW WILL BE MORE
SOUTHWESTERLY...AND THIS TIME THE ECMWF IS A BIT FASTER ON BRINGING
THE SHORTWAVE INTO THE WESTERN PLAINS BY TUESDAY AFTERNOON. THE GFS
IS SLOWER AND DRIER SO WILL KEEP THE CHANCE POPS GOING FOR NOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1251 PM CDT WED AUG 12 2015
VFR CONDS THIS AFTERNOON WITH SOUTHEASTERLY WINDS TURNING
SOUTHERLY THIS EVENING AND VARIABLE BY TOMORROW MORNING AS HIGH
PRESSURE MOVES INTO WRN ND. ISOLD TSTMS POSSIBLE IN W CNTRL AND NW
MN...HOWEVER NOT ENOUGH CONFIDENCE AT SPECIFIC SITES TO ADD
TS...WILL KEEP MENTION OF CB ONLY IN TAFS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...NONE.
MN...NONE.
&&
$$
UPDATE...TG
SHORT TERM...JAM
LONG TERM...JAM/JR
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS NORMAN OK
1234 PM CDT WED AUG 12 2015
.DISCUSSION...
THE 18Z AVIATION DISCUSSION FOLLOWS....
&&
.AVIATION...
PERSISTENT SHRA WITH ISOLATED TSRA CONTINUE ACROSS W OK. THESE
SHRA/TSRA MAY AFFECT KGAG/KWWR/KCSM/KHBR/KLAW THIS
AFTERNOON...POSSIBLY EVEN KSPS...BEFORE FINALLY DISSIPATING LATE
IN THE AFTERNOON. IN GENERAL...BRIEF REDUCTIONS TO VISIBILITY AND
LOWER CEILINGS WILL OCCUR IN THE HEAVIER SHRA/TSRA...OTHERWISE
EXPECT MAINLY VFR CONDITIONS IN -RA. THERE IS A CHANCE THAT THERE
WILL BE -SHRA AGAIN EARLY TOMORROW...BUT THERE APPEARS TO BE MUCH
WEAKER FORCING. MOST LIKELY...WE WILL SEE MID-LEVEL CLOUDS WITH
LITTLE OR NO RA. WINDS WILL VEER GRADUALLY WITH TIME
TONIGHT/TOMORROW...BUT SPEEDS WILL GENERALLY REMAIN BELOW 10 KT.
&&
.PREV DISCUSSION... /ISSUED 1114 AM CDT WED AUG 12 2015/
UPDATE...
SHOWERS/ISOLATED STORMS CONTINUE TO MOVE ACROSS WESTERN PARTS OF
THE FA THIS MORNING. MODELS SHOW THIS ACTIVITY DIMINISHING AT
LEAST SOME THIS AFTN WITH SOME MODELS SHOWING THE RAIN ENDING. THE
RAIN HAS MOVED FURTHER SE THAN THE PREVIOUS FORECAST SO MADE SOME
ADJUSTMENTS TO POP/WX TO ACCOUNT FOR THE CURRENT RADAR TRENDS AND
WILL CONT WITH SOME LOW POPS ACROSS WESTERN PORTIONS OF THE FA
DURING THE AFTN HOURS.
TEMPERATURE FORECAST IS A BIT TRICKY TODAY DUE TO THE RAIN AND THE
CLOUDS. LOWERED TEMPS A FEW DEGREES IN THE NW WHERE RAIN AND
CLOUDS HAVE HAMPERED A WARM UP ALREADY AND SHOULD CONT TO DO SO
FOR AT LEAST A COUPLE MORE HOURS. IF CLOUDS/RAIN HOLD ON LONGER
THAN CURRENT THINKING THEN MAY NOT HAVE LOWERED HIGH TEMPS ENOUGH
BUT ANY BREAKS IN THE CLOUDS COULD MAKE TEMPS RISE RAPIDLY THIS
AFTN. ALL UPDATES OUT SOON.
MAXWELL
PREV DISCUSSION... /ISSUED 613 AM CDT WED AUG 12 2015/
AVIATION...12/12Z TAF ISSUANCE...
LOW/MID LEVEL BKN/OVC DECK OF ACCAS WILL CONTINUE TO BUILD OVER
NWRN OK INTO PORTIONS OF CENTRAL AND WESTERN OK THROUGH THE
MORNING. PRIMARY AVIATION CONCERN WILL BE INCREASING THUNDERSTORM
ACTIVITY OVER NWRN OK THROUGH THE MORNING... IMPACTING KWWR/KGAG.
FELT TEMPOS WERE MOST APPROPRIATE GIVEN LOW CONFIDENCE IN
TIMING/COVERAGE. ELSEWHERE... VFR CONDITIONS ARE EXPECTED TO
PREVAIL... WITH SCT TO BKN MID-LEVEL CLOUDS PERSISTING THROUGH
MUCH OF THE PERIOD AND LIGHT TO MODERATE EASTERLY WINDS.
JTK
PREV DISCUSSION... /ISSUED 258 AM CDT WED AUG 12 2015/
DISCUSSION...
THIS MORNING... SCATTERED SHOWERS CONTINUE TO EVOLVE ACROSS SERN KS
INTO FAR NWRN OK. THIS ACTIVITY IS BEING DRIVEN ALONG A MID-LEVEL
BAROCLINC ZONE OF MOISTURE AND ASCENT WITH THE H700 HIGH CENTERED
OVER THE LLANO ESTACADO IN W CENTRAL TX NEAR LUBBOCK PER SPC
MESOANALYSIS. GOOD REPRESENTATION OF CORRIDOR OF MOISTURE AND ASCENT
CAN BE VISUALIZED ON THE 310 AND 315K ISENTROPIC SURFACES. LATEST
RUNS OF THE HRRR THIS MORNING APPEAR TO BE A TAD BULLISH THROUGH
SUNRISE... DEVELOPING A FAIRLY WIDE AREA OF PRECIP ACROSS SWRN KS
INTO THE NERN PANHANDLES AND NWRN OK. HOWEVER... THE 12/00Z RUN OF
ARW/NMM WRFS ARE ALSO A TAD AGGRESSIVE WITH CONVECTION. SHORT RANGE
SOLUTIONS FROM THE NAM/GFS/ECMWF SUGGEST A SLIGHT UPTICK IN THE LLJ
THROUGH 12Z. IF THIS OCCURS... WE COULD SEE SOME INCREASED
CONVECTIVE DEVELOPMENT THROUGH SUNRISE... MAYBE NOT ON THE ORDER OF
THE HRRR/WRF... BUT MORE THAN WHATS BEEN OCCURRING THROUGH 08Z (3
AM). EITHER WAY... EXPECT AT LEAST SCATTERED DEVELOPMENT TO PERSIST
THROUGH THE MORNING AND LINGER THROUGH THE AFTN ACROSS W/NW OK.
THIS AFTERNOON... BESIDES LINGERING SHOWER/THUNDERSTORM CHANCES...
INCREASING CLOUD COVER THIS AM ACROSS W/NW OK WILL HAVE AN IMPACT ON
AFTN TEMPS. HIGHS THIS AFTN WILL STRUGGLE TO CLIMB INTO THE UPPER
80S... LIKELY SETTLING IN THE MID 80S ACROSS NWRN OK. ELSEWHERE...
EXPECT UPPER 80S TO MID 90S FROM CENTRAL OK INTO NRN TX.
TONIGHT... CONTINUE TO KEEP A SLIGHT CHANCE FOR SCATTERED SHOWERS
AND THUNDER GOING FOR W/NW OK THROUGH THU AM. WITH THE H500 RIDGE
GOING NOWHERE FAST... MID-LEVEL MOISTURE WILL HOLD AND ASCENT WILL
BE SIMILAR TO THIS MORNING... KEEPING A LOW CHANCE FOR ISOLATED TO
SCATTERED CHCS.
FOR THE REMAINDER OF THE WEEK... SEASONABLE TEMPS WILL HOLD THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. THERE ALSO REMAINS A SLIGHT
CHANCE OF SCATTERED SHOWERS AND THUNDERSTORMS FRI ACROSS PORTIONS OF
WRN OK/WRN N TX AS A WEAK H500 SHORTWAVE TRAVERSES THE HIGH. CHCS
WILL LINGER INTO EARLY SAT. OTHER THAN THAT... EXPECT A DRY AND
PLEASANT SUMMER WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 86 66 90 68 / 10 10 0 10
HOBART OK 88 69 94 71 / 40 10 10 0
WICHITA FALLS TX 93 71 95 72 / 10 10 0 0
GAGE OK 82 66 91 70 / 90 20 0 0
PONCA CITY OK 87 65 90 69 / 0 0 0 0
DURANT OK 92 70 94 67 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/23/23
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
1114 AM CDT WED AUG 12 2015
.UPDATE...
SHOWERS/ISOLATED STORMS CONTINUE TO MOVE ACROSS WESTERN PARTS OF
THE FA THIS MORNING. MODELS SHOW THIS ACTIVITY DIMINISHING AT
LEAST SOME THIS AFTN WITH SOME MODELS SHOWING THE RAIN ENDING. THE
RAIN HAS MOVED FURTHER SE THAN THE PREVIOUS FORECAST SO MADE SOME
ADJUSTMENTS TO POP/WX TO ACCOUNT FOR THE CURRENT RADAR TRENDS AND
WILL CONT WITH SOME LOW POPS ACROSS WESTERN PORTIONS OF THE FA
DURING THE AFTN HOURS.
TEMPERATURE FORECAST IS A BIT TRICKY TODAY DUE TO THE RAIN AND THE
CLOUDS. LOWERED TEMPS A FEW DEGREES IN THE NW WHERE RAIN AND
CLOUDS HAVE HAMPERED A WARM UP ALREADY AND SHOULD CONT TO DO SO
FOR AT LEAST A COUPLE MORE HOURS. IF CLOUDS/RAIN HOLD ON LONGER
THAN CURRENT THINKING THEN MAY NOT HAVE LOWERED HIGH TEMPS ENOUGH
BUT ANY BREAKS IN THE CLOUDS COULD MAKE TEMPS RISE RAPIDLY THIS
AFTN. ALL UPDATES OUT SOON.
MAXWELL
&&
.PREV DISCUSSION... /ISSUED 613 AM CDT WED AUG 12 2015/
AVIATION...12/12Z TAF ISSUANCE...
LOW/MID LEVEL BKN/OVC DECK OF ACCAS WILL CONTINUE TO BUILD OVER
NWRN OK INTO PORTIONS OF CENTRAL AND WESTERN OK THROUGH THE
MORNING. PRIMARY AVIATION CONCERN WILL BE INCREASING THUNDERSTORM
ACTIVITY OVER NWRN OK THROUGH THE MORNING... IMPACTING KWWR/KGAG.
FELT TEMPOS WERE MOST APPROPRIATE GIVEN LOW CONFIDENCE IN
TIMING/COVERAGE. ELSEWHERE... VFR CONDITIONS ARE EXPECTED TO
PREVAIL... WITH SCT TO BKN MID-LEVEL CLOUDS PERSISTING THROUGH
MUCH OF THE PERIOD AND LIGHT TO MODERATE EASTERLY WINDS.
JTK
PREV DISCUSSION... /ISSUED 258 AM CDT WED AUG 12 2015/
DISCUSSION...
THIS MORNING... SCATTERED SHOWERS CONTINUE TO EVOLVE ACROSS SERN KS
INTO FAR NWRN OK. THIS ACTIVITY IS BEING DRIVEN ALONG A MID-LEVEL
BAROCLINC ZONE OF MOISTURE AND ASCENT WITH THE H700 HIGH CENTERED
OVER THE LLANO ESTACADO IN W CENTRAL TX NEAR LUBBOCK PER SPC
MESOANALYSIS. GOOD REPRESENTATION OF CORRIDOR OF MOISTURE AND ASCENT
CAN BE VISUALIZED ON THE 310 AND 315K ISENTROPIC SURFACES. LATEST
RUNS OF THE HRRR THIS MORNING APPEAR TO BE A TAD BULLISH THROUGH
SUNRISE... DEVELOPING A FAIRLY WIDE AREA OF PRECIP ACROSS SWRN KS
INTO THE NERN PANHANDLES AND NWRN OK. HOWEVER... THE 12/00Z RUN OF
ARW/NMM WRFS ARE ALSO A TAD AGGRESSIVE WITH CONVECTION. SHORT RANGE
SOLUTIONS FROM THE NAM/GFS/ECMWF SUGGEST A SLIGHT UPTICK IN THE LLJ
THROUGH 12Z. IF THIS OCCURS... WE COULD SEE SOME INCREASED
CONVECTIVE DEVELOPMENT THROUGH SUNRISE... MAYBE NOT ON THE ORDER OF
THE HRRR/WRF... BUT MORE THAN WHATS BEEN OCCURRING THROUGH 08Z (3
AM). EITHER WAY... EXPECT AT LEAST SCATTERED DEVELOPMENT TO PERSIST
THROUGH THE MORNING AND LINGER THROUGH THE AFTN ACROSS W/NW OK.
THIS AFTERNOON... BESIDES LINGERING SHOWER/THUNDERSTORM CHANCES...
INCREASING CLOUD COVER THIS AM ACROSS W/NW OK WILL HAVE AN IMPACT ON
AFTN TEMPS. HIGHS THIS AFTN WILL STRUGGLE TO CLIMB INTO THE UPPER
80S... LIKELY SETTLING IN THE MID 80S ACROSS NWRN OK. ELSEWHERE...
EXPECT UPPER 80S TO MID 90S FROM CENTRAL OK INTO NRN TX.
TONIGHT... CONTINUE TO KEEP A SLIGHT CHANCE FOR SCATTERED SHOWERS
AND THUNDER GOING FOR W/NW OK THROUGH THU AM. WITH THE H500 RIDGE
GOING NOWHERE FAST... MID-LEVEL MOISTURE WILL HOLD AND ASCENT WILL
BE SIMILAR TO THIS MORNING... KEEPING A LOW CHANCE FOR ISOLATED TO
SCATTERED CHCS.
FOR THE REMAINDER OF THE WEEK... SEASONABLE TEMPS WILL HOLD THROUGH
THE WEEKEND AND INTO EARLY NEXT WEEK. THERE ALSO REMAINS A SLIGHT
CHANCE OF SCATTERED SHOWERS AND THUNDERSTORMS FRI ACROSS PORTIONS OF
WRN OK/WRN N TX AS A WEAK H500 SHORTWAVE TRAVERSES THE HIGH. CHCS
WILL LINGER INTO EARLY SAT. OTHER THAN THAT... EXPECT A DRY AND
PLEASANT SUMMER WEEKEND.
JTK
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 86 66 90 68 / 10 10 0 10
HOBART OK 88 69 94 71 / 40 10 10 0
WICHITA FALLS TX 93 71 95 72 / 10 10 0 0
GAGE OK 82 66 91 70 / 90 20 0 0
PONCA CITY OK 87 65 90 69 / 0 0 0 0
DURANT OK 92 70 94 67 / 10 0 0 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
25/23
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
413 PM EDT WED AUG 12 2015
.SYNOPSIS...
AN UPPER TROF WILL KEEP PLEASANT CONDITIONS ACROSS PENNSYLVANIA
INTO FRIDAY. TEMPERATURES WILL REBOUND LATER THIS WEEK WITH HIGH
PRESSURE BUILDING EAST FROM THE MID MISSISSIPPI VALLEY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATED GRIDS AND FORECASTS WITH LATEST DATA AND OBSERVATIONS.
RADAR SHOWS TWO LINES OF SHOWERS OVER THE REGION ONE IN THE
NORTHEAST WHICH IS WEAKER AND ONE WHICH IS MORE ORGANIZED WHICH
JUST PAST THROUGH WILLIAMSPORT. TRIED TO SHOW HIGHER CHANCES IN
AREAS WHERE THESE LINES WILL MOVE THROUGH.
DEEP 500 TROUGH AND MID-LEVEL INSTABILITY HAVE CREATED INSTABILITY
SHOWERS. REALLY HARD TO PIN POINT WHERE IT MIGHT RAIN SO SLIGHT
CHANCE IS BEST OPTION THIS AFTERNOON. THE HRRR DOES SHOW SOME
ORGANIZATION WITH THE SHOWERS NEAR WELLSBORO AND THE BETTER BROKEN
LINE FROM MILESBURG TO SUNBURY INTO BLOOMSBURG AND STILL WATER.
TRIED TO DEPICT CHANCE OF SHOWERS WITH THIS FEATURE.
MOST OF THIS ACTIVITY WILL SUBSIDE RAPIDLY AS SUN ANGLE LOWERS.
MOSTLY CLEAR COOL LATER THIS EVENING AND TONIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
QUIET WX FOR THE SHORT TERM AS THE LONG WAVE RIDGE AND SFC HIGH
MOVE EASTWARD ON THURSDAY. UPPER FLOW FROM THE W/NW. SFC BUBBLE
WILL STRETCH FROM THE MID-ATLANTIC COAST INTO THE CENTRAL PLAINS.
NO WAY FOR MOISTURE FROM THE GULF OR ATLANTIC TO REACH US. FAIR
WEATHER WILL RESULT...WITH CU ONLY OVER THE HIGHER ELEVATIONS. ANY
MORNING VALLEY FOG SHOULD BURN OFF BY 9 AM.
A SURFACE HIGH WILL MOVE SOUTHWEST OF THE AREA ON THURSDAY...
BRINGING CLEARER CONDITIONS. HOWEVER...PERSISTENT UPPER LEVEL
NORTHWEST FLOW WILL HELP BRING ANOTHER DAY OF BELOW NORMAL
TEMPERATURES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
THE SFC HIGH PRESSURE WILL BREAK DOWN AS A SHALLOW TROUGH WILL
DEEPEN AND ALLOW A COLD FRONT TO TRAVERSE THE REGION FRIDAY
AFTERNOON INTO SATURDAY. THE MOISTURE WILL BE FOCUSED ALONG THE
NEW YORK BORDER AND NORTH. THOUGH AS THE TROUGH CONTINUES TO TILT
POSITIVE AND DEEPENS...THERE WILL BE A GREATER CHANCE FOR SHOWERS
AND THUNDERSTORMS ALONG THE CENTRAL MTNS AND THROUGH THE NORTHERN
HALF OF PA. TEMPERATURES WILL BEGIN TO REBOUND UNDER THIS MORE
WESTERLY FLOW OUT AHEAD OF THE FRONT WHICH WILL AID IN ANY
CONVECTION. THE FRONT SHOULD STALL ON SATURDAY...WHICH COULD ALLOW
FOR DAYTIME SUMMER CONVECTION BEFORE THE COLD FRONT PUSHES EAST OF
PENNSYLVANIA ON SUNDAY AND DRY CONDITIONS WILL RETURN FOR THE
BEGINNING OF NEXT WEEK. GIVEN THE PATTERN HAVE ADJUSTED POPS
UPWARD AND SHIFTED THE TIMING ACCORDINGLY. HAVE ADJUSTED
TEMPERATURES UPWARD AS WELL. THE ACTIVE WEATHER PATTERN WILL
CONTINUE THROUGH THE MIDDLE OF NEXT WEEK AS SUCCESSIVE TROUGHS
WILL MOVE THROUGH THE REGION WITH THE NEXT BEST CHANCE TUESDAY
INTO WEDNESDAY.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
VFR CONDITIONS WIDESPREAD...BUT SMALL BRIEF SHOWERS WILL BE
AFFECTING THE CENTRAL TERMINALS FOR THE FIRST FEW HRS OF THE FCST.
IPT MOST AT RISK. NW FLOW SHOULD HELP TO DRY THINGS UP AS THEY
DROP INTO THE LWR SUSQ. THEN CLEARING TAKES PLACE AFTER THE UPPER
TROUGH PUSHES THROUGH. SKY WILL BE MAINLY CLEAR - PROBABLY BEFORE
BEFORE 00Z AT MOST LOCATIONS. ENOUGH INSTABILITY FOR THE NEXT 3-5
HRS TO GENERATE AN ISOLD TSRA AS WELL...MAINLY OVER THE EAST -
AHEAD OF THE TROUGH. HOWEVER...POSSIBILITY IS LOW ENOUGH THAT WILL
NOT MENTION IN TAFS.
HIGH PRESSURE MOVES IN FROM THE OHIO VALLEY. CLEAR SKIES WILL
ALLOW TEMPS TO FALL TO LOWER THAN THE CROSS-OVER VALUES AND FOG
SHOULD FILL IN THE VALLEYS OF THE NORTH AND PERHAPS CENTRAL
MOUNTAINS. WILL PLAY UP IFR FOR BFD AND IPT BUT ONLY TAKE OTHERS
INTO MVFR AT WORST. THE FOG SHOULD DISSIPATE QUICKLY DUE TO FULL
SUN AND DRY LOW LEVELS. THEN...VFR UNDER HIGH PRESSURE. JUST A
EXTREMELY MINIMAL CHC FOR A SHRA IN THE AFTN OVER THE MTNS...BUT
NOT ENOUGH TO MENTION.
OUTLOOK...
FRI...AM VALLEY FOG POSSIBLE. OTHERWISE...NO SIG WX.
FRI NIGHT-SAT...MAINLY VFR...SCATTERED SHOWERS. POSSIBLE
THUNDER.
SUN...NO SIG WX.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...GRUMM
SHORT TERM...DANGELO
LONG TERM...CERU/HAGNER
AVIATION...DANGELO
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
339 PM CDT WED AUG 12 2015
.SHORT TERM...
MID-LEVEL MOISTURE EVIDENT ON WATER VAPOR STREAMING WESTWARD
ACROSS TRANS-PECOS AND BIG BEND THIS AFTERNOON HAS EXPANDED ITS
NORTHERN PERIPHERY INTO THE SOUTH PLAINS. MID-LEVEL MOISTURE
COUPLED WITH WEAK UPSLOPE HAS RESULTED IN CU FIELD SIMILAR TO
YESTERDAY AFTERNOON BUT WITH SOMEWHAT LESS COVERAGE AND FOR NOW
LESS VERTICAL EXTENT.
STEEP LOW LEVEL LAPSE RATES OF -10/KM OR MORE ARE RUNNING INTO
ALMOST AS IMPRESSIVE CAPPING INVERSIONS ACROSS OUR AREA THAT SHOULD
KEEP ANY SHOWERS OR TSTORMS FROM INITIATING. SHORT TERM GUIDANCE
HAS CONTINUED TO STRUGGLE WITH VERTICAL WIND PROFILES AS HIGH
PRESSURE SLOWLY MIGRATES OUT OF WEST TEXAS TOWARD THE FOUR
CORNERS. STREAMLINE SURFACE CONVERGENCE EXTENDING SOUTHWARD DOWN
THE I27 CORRIDOR AND ITS SUBSEQUENT CI CONSISTENTLY ADVERTISED BY
THE HRRR ALL MORNING HAS NOT MATERIALIZED...WHILE THE RAP HAS
STRUGGLED WITH SIMILAR ISSUES. HAVE BEEN WATCHING THE TX/NM BORDER
NEAR THE SW TEXAS PANHANDLE CLOSELY OVER THE LAST COUPLE OF HOURS
GIVEN PERSISTENT SHOWERS AND TSTORMS THE LAST COUPLE OF WEEKS BUT
HAVE DECIDED TO KEEP OUT ANY MENTIONABLE POPS ATTM. ADJUSTED
TEMPS UP A COUPLE OF DEGREES ACROSS OUR SE COUNTIES IN THE ROLLING
PLAINS GIVEN CURRENT TRENDS...OTHERWISE GUIDANCE FOR TEMPS
TODAY...TONIGHT AND TOMORROW SEEM GOOD.
CLOUDS SHOULD CLEAR AFTER SUNSET PROVIDING GOOD VIEWING OF
TONIGHT/S PERSEID METEOR SHOWER PEAKING AFTER MIDNIGHT. HAVE NO
MENTIONABLE POPS IN PLACE OVERNIGHT INTO TOMORROW BUT THERE IS A
NONZERO CHANCE OF LIGHT SHOWERS BRUSHING OUR EASTERN ZONES OFF THE
CAPROCK IF OVERNIGHT CONVECTION SIMILAR TO WHAT WE SAW LAST NIGHT
IS ABLE TO WORK ITS WAY FAR ENOUGH SOUTH OUT OF THE NORTHERN TEXAS
PANHANDLE AND WESTERN OKLAHOMA.
.LONG TERM...
THE UA RIDGE IS STILL PROJECTED TO DRIFT WRD TO ACROSS THE FOUR-
CORNERS BY THIS WEEKEND...AND WILL BE PARKED THERE FOR THE MAJORITY
OF THE EXTENDED PERIOD. A FEW MODEL SOLUTIONS CONTINUE TO HINT AT
CHANCES FOR PRECIP MORE SO OFF THE CAPROCK ON FRIDAY...APPEARING TO
BE COURTESY OF A BIT OF MID-UPPER LEVEL MOISTENING AND WEAK
ISENTROPIC UPGLIDE. ALTHOUGH 1000-2000 J/KG OF SFC-BASED CAPE WILL
BE AVAILABLE...A WEAK CAP IS NOTICEABLE PER MODEL SOUNDINGS
AROUND 700 MB...THEREBY INSINUATING THE POTENTIAL FOR SHOWERY/WEAK
THUNDERSTORM ACTIVITY. BY THE WEEKEND INTO EARLY NEXT WEEK
HOWEVER...FOCUS FOR PRECIP WILL SWITCH TO LOCALES ON THE
CAPROCK...NEAREST TO A SFC TROUGH. ALTHOUGH...FLOW ALOFT WILL BE
FROM A NORTHERLY TO NORTHEASTERLY FLOW WHICH IS NOT VERY CONDUCIVE
FOR STORMS ACROSS THE HIGHER TERRAIN OF NM AND CO TO MAKE IT TO
THE SOUTH PLAINS. IT WILL BE HIGHLY DEPENDENT ON THE LOCATION OF
THE AFOREMENTIONED SFC TROUGH...WHETHER IT WILL BE CONFINED TO NM
/AS SUGGESTED BY MODEL SOLUTIONS/ OR CLOSER TO THE TX/NM BORDER.
NONETHELESS...SLIGHT CHANCE POPS PER THE SUPER-BLENDED SOLUTION
APPEARS REASONABLE ATTM. BY MID-WEEK...AN UA SHORTWAVE POISED TO
MOVE FROM THE NW PACIFIC TO THE CENTRAL/NORTHERN PLAINS WILL
RESULT IN THE DE-AMPLIFICATION OF THE UA RIDGE TO OUR WEST AND
HEIGHT FALLS ACROSS THE SOUTHERN PLAINS AS A COLD FRONT
POTENTIALLY APPROACHES THE CWA. WE WILL SEE IF THIS CHANGE IN THE
SYNOPTIC PATTERN DOES INDEED COME INTO FRUITION...AS THAT COLD
FRONT COULD BE OUR NEXT SHOT AT PRECIP.
GIVEN THE UA RIDGE WILL BE NOT BE DIRECTLY OVERHEAD...TEMPS WILL
WARM TO SEASONAL NORMS THROUGHOUT THE EXTENDED PERIOD /LOWER 90S ON
THE CAPROCK TO MIDDLE TO UPPER 90S OFF THE CAPROCK/.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 65 95 67 95 / 0 0 0 20
TULIA 66 95 67 93 / 0 0 0 20
PLAINVIEW 67 95 68 93 / 0 0 10 20
LEVELLAND 68 96 69 97 / 0 0 0 10
LUBBOCK 69 96 71 97 / 0 0 10 20
DENVER CITY 69 96 69 98 / 0 0 0 10
BROWNFIELD 69 96 69 99 / 0 0 0 10
CHILDRESS 70 97 72 98 / 10 0 10 20
SPUR 70 97 71 98 / 10 10 10 20
ASPERMONT 72 99 73 99 / 10 10 10 20
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55/29
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
308 PM CDT WED AUG 12 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
MAIN FORECAST CONCERNS ARE SMALL PRECIPITATION CHANCES TONIGHT INTO
THURSDAY.
LATEST WATER VAPOR SATELLITE IMAGERY SHOWING UPPER LEVEL RIDGE
AMPLIFYING OVER THE ROCKY MOUNTAINS AND UPPER LEVEL TROUGH OVER
EASTERN UNITED STATES. SHORTWAVE TROUGHS ROTATING AROUND THE UPPER
LEVEL RIDGE INTO THE NORTHERN PLAINS AND SOUTHERN CANADA...AS
EVIDENT PER WATER VAPOR SATELLITE IMAGERY. LATEST 19Z SURFACE
ANALYSIS INDICATES HIGH PRESSURE OVER IOWA INTO THE SOUTHERN PLAINS
STATES. THIS IS PROVIDING MOSTLY SUNNY SKIES ACROSS THE FORECAST
AREA PER VISIBLE SATELLITE IMAGERY.
THE 12.12Z GFS/NAM/ECMWF ARE IN GOOD AGREEMENT BUILDING SURFACE
RIDGE SOUTH OF THE FORECAST AREA INTO THE OHIO RIVER VALLEY TONIGHT
THURSDAY. FIRST IMPULSE OVER-TOPPING THE UPPER LEVEL RIDGE OVER
SOUTHERN MANITOBA WILL PUSH SOUTHEAST INTO CENTRAL WISCONSIN BY 18Z
THURSDAY. LATEST HI-RESOLUTION ARW/NMM/12.17Z HRRR SUGGEST
CONVECTION IN ASSOCIATION WITH IMPULSE WILL WEAKEN AS IT
APPROACHES THE NORTHERN SECTIONS OF THE FORECAST AREA...THIS IS
EVIDENT...WITH THE 12.12Z GFS/NAM INDICATE WEAKENING ELEVATED
INSTABILITY ALONG AND AHEAD OF THE IMPULSE. HAVE CONTINUED THE
TREND OF SMALL PRECIPITATION CHANCES AFTER 09Z THURSDAY AND INTO
THE DAYTIME HOURS THURSDAY...AS THE 12.12Z MODELS SUGGEST WEAK
MOISTURE CONVERGENCE ALONG LINGERING SURFACE FRONT WITH IMPULSE
COULD PRODUCE AN ISOLATED SHOWER OR THUNDERSTORM.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM CDT WED AUG 12 2015
FOCUS TURNS TO THE NEXT SHORTWAVE TROUGH OVER-TOPPING THE UPPER
LEVEL RIDGE THURSDAY EVENING INTO FRIDAY. THE LATEST 12.12Z
GFS/NAM/ECMWF ARE WEAKER WITH 925-850MB MOISTURE CONVERGENCE/LIFT
WITH THIS IMPULSE. WITH THE WEAK LOW LEVEL CONVERGENCE AND
INSTABILITY AXIS ALONG THE SURFACE FRONT/OVER THE FORECAST
AREA...POSSIBILITY OF A SMALL CHANCE OF SHOWERS/THUNDERSTORMS
EXIST THURSDAY NIGHT INTO FRIDAY ACROSS MUCH OF THE FORECAST AREA.
UPPER LEVEL RIDGE AXIS BUILDS INTO THE UPPER GREAT LAKES REGION
FRIDAY AFTERNOON INTO SATURDAY. THE 12.12Z GFS/NAM/ECMWF INDICATE
925MB TEMPERATURES RISING TO PLUS 25 TO PLUS 27 DEGREES CELSIUS
ACROSS THE FORECAST AREA BY 00Z SUNDAY. THE COMBINATION OF
SUBSIDENCE AND 925MB TEMPERATURES...HIGH TEMPERATURES WILL BE IN THE
MIDDLE 80S TO AROUND 90...WITH SOME LOCATIONS POSSIBLY RISING INTO
THE LOWER 90S.
MAIN FORECAST CONCERNS ARE PRECIPITATION CHANCES THROUGH THE PERIOD.
THE 12.12Z GFS/ECMWF/GEM ARE IN GOOD AGREEMENT IN FLATTENING UPPER
LEVEL RIDGE AND DEVELOP WEST TO EAST ZONAL FLOW ACROSS THE NORTHERN
TIER STATES. SIGNIFICANT DIFFERENCES OCCUR BETWEEN THE MODELS ON
TIMING/PLACEMENT OF THE TWO SHORTWAVE TROUGHS/SURFACE FEATURES INTO
THE UPPER GREAT LAKES REGION THROUGH THE PERIOD. FIRST IMPULSE
FLATTENS UPPER LEVEL RIDGE AND PUSHES INTO THE GREAT LAKES REGION
SUNDAY INTO MONDAY. MAIN ENERGY WITH SHORTWAVE TROUGH REMAINS
NORTH OF THE FORECAST AREA. LOW LEVEL MOISTURE CONVERGENCE WITH
SURFACE COLD FRONT WILL PROVIDE A CHANCE OF PRECIPITATION ACROSS
MUCH OF THE FORECAST MAINLY SUNDAY NIGHT INTO MONDAY MORNING. NEXT
FEATURE TO IMPACT THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
DIFFERENCES OCCUR BETWEEN THE 12.12Z GFS/ECMWF ON
STRENGTH/TIMING/PLACEMENT WITH THIS FEATURE. THE MODELS SUGGEST
DECENT MOISTURE CONVERGENCE/TRANSPORT AND LIFT WITH THE SHORTWAVE
TROUGH/SURFACE FEATURE. BASED ON TIMING/PLACEMENT DIFFERENCES WITH
THE MODELS...WILL CONTINUE THE TREND OF A CHANCE OF PRECIPITATION
ACROSS THE FORECAST AREA TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1210 PM CDT WED AUG 12 2015
VFR CONDITIONS EXPECTED AT BOTH AIRFIELDS THROUGH THE PERIOD.
PRIMARY CONCERN IS FOR POTENTIAL FOR BROKEN MID-LEVEL CEILINGS
LATE TONIGHT INTO THURSDAY MORNING AS WEAK SYSTEM MOVES THROUGH.
SMALL CHANCE FOR ISOLATED -SHRA...BUT TOO ISOLATED TO INCLUDE IN
TAFS AT THIS TIME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...MW
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
THE LATEST RAP ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM TEXAS TO THE GULF OF MEXICO. MID-LEVEL
WARM ADVECTION IS GENERATING A BAND OF CLOUDS OVER THE UPPER
PENINSULA AND NORTHEAST WISCONSIN WHERE A COUPLE LIGHT SHOWERS HAVE
DEVELOPED OVER THE PAST HOUR. WILL KEEP AN ISOLATED MENTION OVER NE
WI THROUGH EARLY THIS EVENING AS A RESULT. LOOKING UPSTREAM...A
SHORTWAVE TROUGH IS TRIGGERING SHOWERS AND STORMS OVER SOUTHERN
MANITOBA. AS THIS SHORTWAVE MOVES SOUTHEAST INTO THE REGION
TONIGHT...THUNDERSTORM TRENDS ARE THE MAIN FORECAST CONCERN IN THE
SHORT TERM.
TONIGHT...MID-LEVEL WARM ADVECTION WILL EXIT NORTHEAST WISCONSIN
THIS EVENING...WHICH SHOULD ENSURE DECREASING CLOUDS FOR THAT PART
OF THE STATE. OTHER LOCATIONS WILL SEE MOSTLY CLEAR CONDITIONS TO
START OUT THE EVENING...THEN WILL SEE INCREASING CLOUDS FROM THE
NORTHWEST. THESE CLOUDS WILL BE AHEAD OF A SHORTWAVE TROUGH SLIDING
SOUTHEAST OVER SOUTHEAST MANITOBA. THE SHORTWAVE ITSELF WILL NOT
ARRIVE UNTIL LATE IN THE NIGHT OVER N-C WISCONSIN. WILL HAVE A
DECENT AMOUNT OF ELEVATED INSTABILITY AND MOISTURE TRANSPORT AHEAD
OF THE WAVE...SO WILL RAISE THUNDERSTORM CHANCES. LOWS MAINLY IN
THE 60S.
THURSDAY...THE SHORTWAVE WILL MOVE ACROSS NORTHERN WISCONSIN DURING
THE MORNING HOURS...GIVING MOST LOCATION AT LEAST A SLIGHT CHANCE OF
THUNDERSTORMS. HIGHEST CHANCES WILL BE ACROSS THE NORTH. THEN
CONFIDENCE WANES IN THE WAKE OF THE SHORTWAVE. SHOULD SEE SOME
SUBSIDENCE BEHIND THE WAVE...BUT GUIDANCE SHOWS A SURFACE
TROUGH/WIND SHIFT MOVING INTO THE FORECAST AREA DURING THE
AFTERNOON. MOISTURE POOLING ALONG THE BOUNDARY WILL LEAD TO ML
CAPES APPROACHING 2000 J/KG DURING PEAK HEATING IN THE AFTERNOON.
LARGE-SCALE SUPPORT IS NOTICEABLY ABSENT...BUT IF THAT SORT OF
DESTABILIZATION OCCURS...IT WOULD NOT TAKE MUCH CONVERGENCE TO SET
OFF STORMS. 0-6KM WIND SHEARS ARE AROUND 25 KTS...SO THINK STORMS
WILL BE RATHER PULSY IN NATURE. STILL COULD SEE A FEW STRONG STORMS
DEVELOP THAT COULD CREATE STRONG GUSTY WINDS AND MARGINALLY SEVERE
HAIL. BEST TIMING WOULD BE AFTER 3 PM. WARMER AND MORE HUMID WITH
HIGHS IN THE MID TO UPPER 80S.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 229 PM CDT WED AUG 12 2015
UPR RDG AXIS OVER THE CNTRL/SRN PLAINS IS FCST TO EXTEND NEWD INTO
THE WRN GREAT LAKES BY THE END OF THE WEEK BEFORE RETROGRADING AND
WEAKENING TOWARD THE SW CONUS NEXT WEEK. THIS PATTERN SHIFT WL
ALLOW FOR THE MAIN BAND OF WESTERLIES TO RUN ALONG THE NRN TIER OF
STATES AND ALLOW FOR A COUPLE OF SYSTEMS TO MOVE ACROSS WI. AFTER
THE INITIAL NW FLOW PCPN CHCS END FRI...THE PASSAGE OF A CDFNT
LATE SUNDAY INTO MON WL BRING THE NEXT CHC OF PCPN TO NE WI. A
STRONGER SYSTEM CONSISTING OF ANOTHER CDFNT AND STRONGER SHORTWAVE
TROF REACHES THE REGION TOWARD THE MIDDLE OF NEXT WEEK WITH A
HIGHER CHC OF SHWRS/TSTMS. TEMPS ARE EXPECTED TO BE ABOVE NORMAL
THRU SUNDAY...COOL A BIT BELOW NORMAL EARLY NEXT WEEK AND THEN
BEGIN TO WARM THEREAFTER.
INITIAL PRE-FRONTAL TROF TO STILL BE IN THE PROCESS OF EXITING
E-CNTRL WI THU EVENING...THUS A CHC POP IS NECESSARY FOR THIS
LOCATION. MEANWHILE...THE PRIMARY CDFNT IS FCST TO DROP SE TOWARD
NRN WI LATER THU NGT AND INTRODUCE ANOTHER CHC OF SHWRS AND TSTMS.
IN ADDITION TO THE SFC BOUNDARIES...MODELS INDICATE A MODEST
SHORTAVE TROF MOVING SE THRU THE WRN GREAT LAKES ACCOMPANIED BY
EMBEDDED SHORTWAVE ENERGY. POPS IN BOTH LOCATIONS TO BE HELD IN
THE CHC CATEGORY FOR NOW. TEMPS TO REMAIN ON THE MILD SIDE WITH
MINS IN THE LWR 60S NORTH...MID TO UPR 60S SOUTH.
THE CDFNT IS PROGGED TO CONT MOVING SE INTO WI ON FRI...ALTHO THE
MODELS DISAGREE WITH HOW FAST THE FNT WL ACTUALLY MOVE. THE NAM IS
SLOWER...BUT WITH THE NW FLOW ALOFT STILL OVERHEAD...BELIEVE A
FASTER FRONTAL MOVEMENT MAKES MORE SENSE. PCPN COVERAGE IS ANOTHER
PROBLEM AS THE ATMOSPHERE WL BECOME UNSTABLE WITH CAPES AROUND
1500 J/KG AND LI`S DOWN TO AROUND -4. DESPITE THE INSTABILITY...
MOISTURE AVAILABILITY AND FRONTAL BOUNDARY NEARBY...MODELS CONT TO
SHOW A LIMITED PCPN COVERAGE PRIMARILY DUE TO UPR HEIGHTS BUILDING
TOWARD WI AND PROVIDING A CAP TO INHIBIT TSTM GROWTH. SINCE NE WI
TO SIT ON THE EDGE OF THIS BUILDING CAP...PREFER TO KEEP CHC POPS
IN THE FCST. FRI WL BE A VERY WARM AND HUMID DAY WITH MAX TEMPS
RANGING FROM THE MID 80S NORTH AND ALONG LAKE MI...TO THE UPR 80S
TO LWR 90S ELSEWHERE.
DEPENDING ON THE EXACT TIMING OF THE CDFNT...CANNOT COMPLETELY
RULE OUT A LINGERING SHWR OR STORM OVER SRN SECTIONS OF THE FCST
AREA FRI EVENING. OTHERWISE...THE UPR RDG WL CONT TO BUILD INTO WI
FRI NGT...ALONG WITH A WEAK SFC HI OVER THE GREAT LAKES. SKIES
SHOULD BECOME MOSTLY CLEAR AND WITH LIGHT WINDS EXPECTED...WE
COULD SEE SOME PATCHY FOG DEVELOP OVRNGT. MIN TEMPS TO RANGE FROM
THE MID TO UPR 50S NORTH...LWR TO MID 60S SOUTH. THE UPR RDG WL
EXTEND FROM THE FOUR CORNERS REGION NEWD TO THE GREAT LAKES ON SAT
AND BRING ANOTHER VERY WARM/MUGGY DAY TO NE WI. THERE SHOULD BE A
SUFFICIENT CAP IN PLACE TO PREVENT ANY TSTMS FROM DEVELOPING
DESPITE THE INCREASED INSTABILITY. LOOK FOR MAX TEMPS TO AGAIN
RANGE FROM THE LWR TO MID 80S NORTH AND NEAR LAKE MI...UPR 80S TO
LWR 90S CNTRL/E-CTNRL WI.
THIS UPR RDG WL BEGIN TO LOSE ITS INFLUENCE OVER THE GREAT LAKES
DURING THE LATTER HALF OF THE WEEKEND AS A LEAD SHORTWAVE TROF
PUSHES EWD ALONG THE U.S.-CANADIAN BORDER. WHILE SAT NGT WL REMAIN
DRY/MILD/MUGGY...THE SHORTWAVE TROF IS FCST TO MOVE INTO THE UPR
MS VALLEY ON SUNDAY...PRECEDED BY A CDFNT THAT COULD REACH NW WI
AS EARLY AS LATE SUNDAY AFTERNOON. WHILE MOST OF NE WI TO STAY DRY
THRU THE DAYLIGHT HOURS...WL NEED TO MENTION A CHC OF SHWRS/TSTMS
FOR N-CNTRL WI...MAINLY DURING THE AFTERNOON. SUNDAY ALSO LOOKS TO
BE YET ANOTHER VERY WARM/HUMID DAY WITH MAX TEMPS IN THE LWR TO
MID 80S NORTH/LAKESHORE...85-90 DEG RANGE ELSEWHERE.
THIS CDFNT DOES NOT APPEAR TO BE A FAST-MOVER...MAINLY DUE TO THE
REMNANTS OF THE UPR RDG TO OUR SOUTH. LATEST TIMING HAS THE FNT
REACHING CNTRL WI BY 12Z MON AND CLEARING E-CNTRL WI AROUND 18Z
MON. ANOTHER CONCERN WL BE A TRAILING SHORTWAVE TROF/EMBEDDED
SHORTWAVE PUSHING INTO THE WRN GREAT LAKES REGION MON AFTERNOON.
THERE WL BE A GOOD CHC FOR SHWRS/TSTMS TO ACCOMPANY THE FROPA
SUNDAY NGT THRU MON MORNING WITH THE POSSIBILITY OF SOME SHWRS
LINGERING OVER E-CNTRL WI INTO MON AFTERNOON. MAX TEMPS TO BE MUCH
COOLER ON MON WITH READINGS IN THE LWR 70S N-CNTRL...MID TO UPR
70S E-CNTRL WI.
A MODEST HI PRES IS FCST TO BUILD INTO THE REGION ON TUE...THEREBY
BRINGING PARTLY CLOUDY SKIES TO THE FCST AREA. PLENTY OF ISSUES
THEN HEADED INTO WED AS THE SFC HI DEPARTS...WAA DEVELOPS AND A
RATHER SHARP SHORTWAVE TROF ENTERS THE CNTRL CONUS. MODELS ARE ALL
OVER THE PLACE AS FAR AS TIMING OF PCPN CHCS INTO NE WI RANGING
FROM TUE NGT TO WED NGT. HAVE FOLLOWED THE CONSENSUS SOLUTION FOR
NOW WHICH BRINGS PCPN CHCS TO THE ENTIRE REGION FOR THE TIME
BEING. TEMPS FOR TUE AND WED SHOULD BE AT OR SLIGHTLY BELOW
NORMAL.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1152 AM CDT WED AUG 12 2015
VFR CONDITIONS TO PREVAIL THROUGH MOST IF NOT ALL OF
THE TAF PERIOD. SCATTERED MID CLOUDS OVER NORTHERN WISCONSIN MAY
PRODUCE A SHOWER THIS AFTERNOON...BUT COVERAGE IS EXPECTED TO BE TOO
SPARSE TO INCLUDE IN ANY TAF SITES. A PERIOD OF MOSTLY CLEAR SKIES
WILL FOLLOW THIS EVENING BEFORE CLOUDS INCREASE AGAIN. A SHORTWAVE
OVER SOUTHERN MANITOBA WILL BE MOVING ACROSS THE REGION OVERNIGHT
INTO THURSDAY MORNING. CLOUDS WILL MAINLY BE MID-LEVEL...BUT
SCATTERED SHOWERS AND STORMS WILL BE POSSIBLE WITH THE
SHORTWAVE...SO CIGS/VSBYS MAY BRIEFLY FALL IN ANY RAIN. ADDITIONAL
STORMS COULD FIRE THURSDAY AFTERNOON...MAINLY OVER CENTRAL AND
NORTHEAST WI.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......KALLAS
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1230 PM MDT WED AUG 12 2015
.UPDATE...
ISSUED AT 627 AM MDT WED AUG 12 2015
RECENT 11-3.9 MICROMETER SATELLITE IMAGERY AND SURFACE OBS ARE NOW
SHOWING PATCHY FOG OVER PORTIONS OF SOUTHEAST WYO AND THE WESTERN
NEB PANHANDLE. DESPITE AN INCREASE IN MIDLEVEL CLOUD COVER...LIGHT
WINDS AND EXCELLENT BOUNDARY LAYER MOISTURE WITH DEW POINTS IN THE
50S TO AROUND 60 F ARE LIKELY CONTRIBUTING TO THIS. GIVEN SEVERAL
OBS INDICATING TEMP-DEWPOINT SPREADS LESS THAN 2 DEG F...ISSUED A
QUICK GRID UPDATE TO INCLUDE PATCHY FOG ALONG/EAST OF THE LARAMIE
RANGE THROUGH 15Z THIS AM. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
PERSISTENCE. THAT IS THE NAME OF THE GAME THROUGH MOST OF THE SHORT
TERM PERIOD AS HIGH-AMPLITUDE UPPER LEVEL RIDGING REMAINS ANCHORED
OVER THE CENTRAL ROCKIES THROUGH THE END OF THE WORK WEEK. THIS WILL
RESULT IN TYPICAL WYOMING WEATHER FOR MID AUGUST...AS HIGH PRESSURE
CENTERED OVER TX/OK WILL YIELD A PERSISTENT FEED OF MONSOON MOISTURE
STREAMING NORTHWARD INTO THE CWA. CONVECTIVE CHANCES WILL EXIST EACH
AFTERNOON/EVENING...AND MOST AREAS WILL SEE VERY LITTLE VARIATION IN
HIGHS FROM DAY TO DAY. IN THE NEAR TERM...DECIDED TO REMOVE MENTION
OF FOG EARLY THIS AM AS NAM/GFS BUFKIT SOUNDINGS SUGGEST ONLY MODEST
LLVL SATURATION AND THE HRRR KEEPS VISIBILITY HIGH. SCATTERED STORMS
SHOULD DEVELOP ALONG/WEST OF THE LARAMIE RANGE THIS AFTERNOON...AND
BECOME MORE WIDESPREAD AFTER 00Z AS A PRONOUNCED MID LEVEL VORT MAX
TRACKS ACROSS CENTRAL WYO. WOULD EXPECT THIS TIME PERIOD TO BE MORE
ACTIVE THAN THE REST OF THE PERIOD GIVEN COOLER MID LEVEL TEMPS AND
GENERALLY BETTER DYNAMICS. NO SEVERE WEATHER EXPECTED WITH LESS THAN
15 KTS OF H5 FLOW...BUT SLOW MOVING STORMS COULD YIELD SOME CONCERNS
FOR FLASH FLOODING WITH GFS PWATS OVER ONE INCH. THERMAL ENVIRONMENT
WILL BECOME WARMER AND MORE CAPPED LATER IN THE WEEK...SO EXPECT THE
BEST CHANCES FOR CONVECTION TO BE OVER HIGHER TERRAIN ON THU/FRI. H7
TEMPS AVERAGING AROUND +14 TO +16 C FROM ALL MODELS SUGGESTS A WARM
FORECAST PERIOD WITH HIGHS AROUND 90 F OVER MUCH OF THE PLAINS.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 217 AM MDT WED AUG 12 2015
ALL MEDIUM TO LONG RANGE MODELS SHOW THE UPPER LEVEL
HIGH...CENTERED NEAR THE FOUR CORNERS REGION...SLOWLY RETROGRADING
AND WEAKENING A BIT BY SUNDAY...AS ENERGY FROM THE NORTHERN
PACIFIC DIVES SOUTHEAST INTO THE NORTHWEST UNITED STATES. UNTIL
THEN...EXPECT THE PERSISTENT WEATHER PATTERN TO CONTINUE INTO THE
WEEKEND WITH SOUTHWEST FLOW ALOFT AND DAYTIME CONVECTION DUE TO
THE ADVECTION OF MONSOON MOISTURE FROM THE SOUTHWEST UNITED
STATES. HIGH TEMPERATURES WILL BE ABOVE NORMAL SATURDAY WITH
READINGS IN THE 80S TO MID 90S ACROSS MOST OF THE AREA. PORTIONS
OF WESTERN NEBRASKA AND FAR EASTERN WYOMING MAY REACH THE UPPER
90S ON FRIDAY AS 700MB TEMPERATURES PEAK BETWEEN 15C TO 18C. WITH
PW/S OVER ONE INCH ACROSS THE HIGH PLAINS...THERE WILL BE PLENTY
OF MOISTURE FOR SHOWERS AND TSTORMS TO DEVELOP. HOWEVER...STILL NOT
CONFIDENT ON THE COVERAGE ON SATURDAY DUE TO THE STRENGTH OF THE
UPPER LEVEL HIGH WHICH WILL RESULT IN SUBSTANTIAL MIDLEVEL
SUBSIDENCE...AND MAY SUPPRESS SCATTERED CONVECTION.
HOWEVER...SOME OF THESE TSTORMS MAY CONTAIN VERY HEAVY RAINFALL
WITH ISOLATED FLASH FLOODING POSSIBLE. SEVERE TSTORMS APPEAR
UNLIKELY AT THIS TIME DUE TO THE LACK OF SHEAR ACROSS THE AREA.
MODELS ARE TRENDING TOWARDS BETTER AGREEMENT AND ARE MORE
CONSISTENT WITH THE OVERALL PATTERN NEXT WEEK. THE GFS HAS TRENDED
TOWARDS THE ECMWF SOLUTION...SHOWING A SERIES OF STRONG COLD
FRONTS FOR THIS TIME OF THE YEAR MOVING ACROSS THE REGION. MODELS
SHOW A STRONG PACIFIC TROUGH MOVING INTO WYOMING ON TUESDAY WITH A
STRONG COLD FRONT MOVING ACROSS THE AREA. IF THE ECMWF SOLUTION
VERIFIES...TEMPERATURES MAY BE AUTUMN-LIKE BY NEXT WEDNESDAY.
COOLER AIR MAY SPREAD INTO THE HIGH PLAINS AS EARLY AS MONDAY WITH
ALL MODELS SHOWING A SHALLOW BACK-DOOR COLD FRONT MOVING SOUTHWEST
ACROSS THE HIGH PLAINS. LOWERED HIGH TEMPERATURES INTO THE 80S
ALONG AND EAST OF THE I25 CORRIDOR. THE MAIN COLD FRONT IS
FORECAST TO PUSH ACROSS THE AREA SOMETIME ON WEDNESDAY...WITH
TEMPERATURES POTENTIALLY LOWERING BELOW NORMAL. MODELS ARE
RELATIVELY DRY WITH THIS FRONTAL PASSAGE...BUT GIVEN THE DYNAMICS
AND RELATIVELY HIGH PW/S ACROSS THE PLAINS...BELIEVE THERE WILL BE
SOME SHOWER/TSTORM ACTIVITY AHEAD AND BEHIND THE FRONT. KEPT POP
AROUND 20 PERCENT FOR NOW...BUT LOWERED TEMPERATURES INTO THE 70S
ACROSS MOST OF SOUTHEAST WYOMING AND NORTHERN NEBRASKA.
KEEP IN MIND THESE FORECAST TEMPERATURES ARE STILL 10 TO 15
DEGREES WARMER THAN WHAT THE ECMWF INDICATES TUESDAY NIGHT AND
WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1217 PM MDT WED AUG 12 2015
MAIN AVIATION FOCUS TODAY CENTERS ON THUNERSTORM POTENTIAL THIS
AFTERNOON THROUGH EARLY EVENING AS MONSOONAL MOISTURE COMBINES
WITH A PASSING WEATHER DISTURBANCE. CONVECTIVE CLOUDS WILL
CONTINUE BLOSSOMING ACROSS THE REGION AS THE AFTERNOON PROGRESSES.
FOR NOW HAVE INCLUDED VCTS AT ALL SOUTHEAST WYOMING TERMINALS
ALONG WITH KBFF AND WILL NEED TO KEEP CLOSE WATCH ON RADAR TRENDS
FOR ANY POTENTIAL AMENDMENTS THIS AFTERNOON. STORM MOVEMENT WILL
BE RELATIVELY SLOW SO HEAVY RAIN WOULD BE THE MAIN CONCERN. THIS
ACTIVITY WILL DISSIPATE WITH SUNSET WITH SOME CLEARING ANTICIPATED
AFTER MIDNIGHT. FOG MAY BE A POTENTIAL AGAIN ACROSS THE WRN
NEBRASKA PANHANDLE AIRFIELDS LATER TONIGHT...BUT AM NOT CONFIDENT
TO ADD IT IN JUST YET.
&&
.FIRE WEATHER...
ISSUED AT 217 AM MDT WED AUG 12 2015
NO MAJOR FIRE WEATHER CONCERNS THROUGH FRIDAY WITH WIND GUSTS LIKELY
TO REMAIN BELOW 25 MPH AND AFTN HUMIDITIES ABOVE 20-25 PCT. ISOLATED
TO SCATTERED SHOWERS AND THUNDERSTORMS SHOULD OCCUR EACH DAY GIVEN A
TYPICAL MONSOON PATTERN IN PLACE. BEST CHANCE FOR WETTING RAINS WILL
BE LATE THIS AFTERNOON AND OVERNIGHT. AS USUAL...EXPECT GUSTY AND/OR
ERRATIC WINDS NEAR THUNDERSTORMS IN ADDITION TO FREQUENT CLOUD-TO-
GROUND LIGHTNING.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...CLH
SHORT TERM...CLH
LONG TERM...TJT
AVIATION...CAH
FIRE WEATHER...CLH