Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/06/14
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
910 AM MST MON AUG 4 2014
.SYNOPSIS...
A STRONG UPPER LOW WILL EXIT THE REGION BY TONIGHT...BUT LINGERING
MOISTURE WILL STILL PROVIDE CHANCES FOR LATE MORNING AND AFTERNOON
SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN EAST OF PHOENIX.
A SIGNIFICANT DRYING TREND WILL OVERSPREAD THE REGION BEGINNING
TONIGHT ESSENTIALLY CUTTING OFF ANY STORM CHANCES FOR TUESDAY
THROUGH THURSDAY. A GRADUAL RETURN OF STORM CHANCES FROM EAST TO
WEST IS THEN EXPECTED TO BEGIN BY THE END OF THE WEEK...LIKELY
CONTINUING INTO THE UPCOMING WEEKEND.
&&
.DISCUSSION...
A MUCH QUIETER SCENE ACROSS OUR CWA THIS MORNING WHEN COMPARED TO
ALL OF THE CONVECTIVE ACTIVITY WE SAW YESTERDAY...AS THE UPPER LOW
THAT TRIGGERED ALL THESE STORMS CONTINUES TO MOVE OFF WELL TO OUR
NORTH...AND IS NOW OVER CENTRAL NV. DEEP SOUTHWESTERLY FLOW BEHIND
THIS LOW CENTER HAS PULLED DRIER AIR INTO THE REGION...AND CLEARED
SKIES OVER MOST AREAS. THE ONLY AREAS THAT ARE NOW SEEING CLOUDS ON
THE LATEST SATELLITE IMAGERY ARE OVER GILA COUNTY AND POINTS EAST
AND ACROSS SW CA...WHERE A WEAK SHORTWAVE ROTATING AROUND THE
DEPARTING UPPER LOW CENTER IS PROVIDING SOME WEAK LIFT. ALTHOUGH THE
LATEST RUN OF THE HRRR HIGH-RES MODEL CONTINUES TO SHOW THE
DEVELOPMENT OF ISOLATED TO SCATTERED SHOWER/TS ACTIVITY OVER GILA
COUNTY AND SE CA FOR A BRIEF PERIOD THIS AFTERNOON...HAVE DECIDED TO
REDUCE POPS A BIT OVER BOTH LOCATIONS SINCE THE LATEST GFS FCST
SOUNDINGS CONTINUE TO SHOW CONTINUED DRYING/STABILIZATION THROUGH
THE COLUMN THROUGH THE REST OF TODAY. OTHER THAN THE AFOREMENTIONED
CHANGES AND SOME MINOR ADJUSTMENTS TO DEWPOINT AND HOURLY
TEMPERATURE TRENDS...CURRENT GRIDDED FCSTS ARE STILL LOOKING
GOOD...AND NO FURTHER UPDATES ARE PLANNED AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
THE UNSEASONABLY POTENT UPPER LOW THAT ALLOWED FOR WIDESPREAD STORM
ACTIVITY ON SUNDAY CONTINUES TO PROGRESS TO THE NORTH WITH THE LOW
CENTER NOW IN SOUTHERN NEVADA. SOUTHWESTERLY FLOW BEHIND THE LOW HAS
ALLOWED FOR SIGNIFICANT DRYING ALOFT ACROSS SOUTHWEST AND PORTIONS
OF SOUTH-CENTRAL ARIZONA. DEEPER MOISTURE REMAINS ACROSS EASTERN
ARIZONA EARLY THIS MORNING WITH A LINE OF SHOWERS AND THUNDERSTORMS
STILL ONGOING. RESIDUAL LOW LEVEL MOISTURE IN COMBINATION WITH THE
CLOSER PROXIMITY TO THE UPPER LOW CENTER MAY ALLOW FOR SOME
CONTINUED ISOLATED SHOWERS AND MAYBE A THUNDERSTORM ACROSS RIVERSIDE
COUNTY CALIFORNIA THROUGH EARLY AFTERNOON. EXPECTING BOUNDARY LAYER
MOISTURE TO BE SCOURED OUT FROM WEST TO EAST STARTING THIS
AFTERNOON...BUT SOME LINGERING MOISTURE SHOULD REMAIN ACROSS THE
HIGHER TERRAIN EAST OF PHOENIX. HAVE KEPT CHANCE POPS FOR THIS
AFTERNOON ACROSS SOUTHERN GILA COUNTY AS SUFFICIENT MOISTURE WILL
REMAIN IN PLACE.
FOR TUESDAY THROUGH THURSDAY SOUTHWESTERLY DRY FLOW WILL DOMINATE
WITH PRECIPITABLE WATER VALUES DROPPING TO BELOW AN INCH AND
POSSIBLY EVEN BELOW A HALF AN INCH ACROSS OUR WESTERN ZONES. THE
SYNOPTIC FLOW PATTERN ALLOWING FOR THE SOUTHWESTERLY FLOW WILL BE
THE RESULT OF THE NEARLY STATIONARY SUBTROPICAL HIGH CENTER OVER
NORTHERN MEXICO AND PERSISTENT BROAD TROUGHING ACROSS CALIFORNIA
INTO THE GREAT BASIN. MAY SEE AN ISOLATED SHOWER OR THUNDERSTORM
ACROSS FAR EASTERN GILA COUNTY DURING THE PERIOD...SO HAVE KEPT
AFTERNOON LOW END SLIGHT CHANCE POPS GOING. TEMPERATURES FOR THE
PERIOD WILL REMAIN NEAR SEASONAL NORMALS AS HEIGHTS BARELY BUDGE.
THE BROAD TROUGHING TO OUR NORTHWEST SHOULD KEEP TEMPERATURES FROM
RISING AT LEAST THROUGH THE END OF THE WEEK.
MODEL DIFFERENCES CAN BE SEEN STARTING FRIDAY INTO THE COMING WEEKEND
AS THE GFS BEGINS TO SHIFT LOW LEVEL WINDS TO MORE OF A
SOUTHEASTERLY DIRECTION WHEREAS THE EUROPEAN KEEPS DRY SOUTHWESTERLY
FLOW. DON/T HAVE MUCH FAITH IN THE DRY EUROPEAN SOLUTION AS EARLIER
MODEL RUNS SHOWED MOISTURE SEEPING INTO SOUTH-CENTRAL ARIZONA
STARTING FRIDAY ALONG WITH THE GFS. BELOW NORMAL CLIMO POPS ARE IN
THE FORECAST FOR FRIDAY AND SATURDAY...BUT SLIGHT CHANCES ARE
SOMEWHAT EXTENDED INTO THE LOWER DESERTS. WILL HAVE TO WAIT FOR
FURTHER MODEL RUNS TO GET A CLEARER SIGNAL ON WHEN MOISTURE WILL
RETURN. BOTH THE GFS AND THE EUROPEAN SHOW THE SUBTROPICAL HIGH
SHIFTING NORTHWARD INTO THE FOUR CORNERS REGION SOME TIME AROUND
SUNDAY INTO EARLY NEXT WEEK INCREASING HEIGHTS AND PROVIDING A MORE
FAVORABLE FLOW TO BRING IN AT LEAST SOME MOISTURE FROM MEXICO.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
NO AVIATION IMPACTS ANTICIPATED THROUGH MONDAY NIGHT AS THUNDERSTORM
ACTIVITY SHOULD REMAIN WELL NORTH AND EAST OF TERMINALS...AND ONLY
OCCASIONAL FEW-SCT CLOUDS AOA 9K FT. WITH NO OUTFLOW WINDS TO
CONTEND WITH...SPEEDS WILL BE GENERALLY AOB 8KT AND DIRECTIONAL
CHANGES POTENTIALLY LEADING TO PERIODS OF NEARLY CALM OR VARIABLE
SFC WINDS.
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA INCLUDING KIPL...AND
KBLH...
MOSTLY CLEAR SKIES THROUGH MONDAY NIGHT WITH NO AVIATION IMPACTS.
SFC WINDS WILL GENERALLY PREVAIL WITH A WLY OR SLY COMPONENT...AND A
FEW GUSTS ABOVE 15KT MAY BE POSSIBLE LATE AFTERNOON AND EARLY
EVENING WITH PERIODS OF VARIABLE LIGHT SFC WINDS LATE NIGHT THOUGH
MORNING HOURS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
PREDOMINANTLY DRY WEATHER DURING THE MIDDLE OF THE WEEK WILL ONLY
GIVE WAY TO SLIGHTLY INCREASED CHANCES OF RAIN BY THE WEEKEND. THE
DRY AIR IN PLACE WILL RESULT IN AFTERNOON MINIMUM HUMIDITY VALUES IN
THE TEENS AT LOWER ELEVATIONS AND 20 TO 30 PERCENT IN THE
MOUNTAINS...WITH SOME TREND FOR MORE MOIST CONDITIONS LATER IN THE
PERIOD. OVERNIGHT RECOVERY WILL BE GOOD TO EXCELLENT. WINDS SHOULD
NOT BE A LARGE PROBLEM...THOUGH LOCAL GUSTS ASSOCIATED WITH ANY
THUNDERSTORMS WILL BE POSSIBLE BY THE WEEKEND TIME FRAME.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/KUHLMAN
AVIATION....MO
FIRE WEATHER...MO
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
734 PM MDT TUE AUG 5 2014
.UPDATE...
ISSUED AT 701 PM MDT TUE AUG 5 2014
AM UPDATING ZONES FOR CONVECTIVE TRENDS...HIGHER CHANCES ON THE
EASTERN PLAINS...ISOLATED THUNDERSTORMS TO THE WEST. LIGHTNING
TRENDS SHOW A THIN LINE OF STORMS THAT EXTEND FROM PIKES PEAK TO
NEAR STEAMBOAT SPRINGS...THAT LINE IS STEADILY MARCHING TO THE
EAST AT 20 TO 25 MPH AND IT LOOKS LIKE THE LAST CONVECTION OF THE
EVENING...AS DRY AIR HAS INFILTRATED SOUTHWEST COLORADO AND CLOUDS
LOOK A LOT FLATTER OVER THE MOUNTAINS. STORMS IN EASTERN COLORADO
HAVE BEEN DROPPING SOME EXTREMELY HEAVY RAIN...BUT FOR THE MOST
PART HAVE STARTED TO MOVE...WE MAY STILL SEE SOME LOCAL FLOODING
PROBLEMS UNTIL THE STORMS GET OUT OF THE STATE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 328 PM MDT TUE AUG 5 2014
NUMEROUS SHOWERS AND THUNDERSTORMS OVER THE MOUNTAINS ARE PUSHING
NORTHEAST. SOME CELLS HAVE BEEN PRODUCING BETWEEN A THIRD TO A
HALF OF AN INCH OF RAIN IN ABOUT 15-30 MINUTES...WITH STRONGER
CELLS PRODUCING OVER THREE-QUARTERS OF AN INCH. A CURRENT PW
VALUES HOVERING ABOUT AN INCH RIGHT NOW AND ARE EXPECTED TO START
LOWERING AS DRIER AIR...EVIDENT ON WATER VAPOR SATELLITE...MOVES
IN FROM THE SOUTHWEST. DEWPOINTS IN THE UPPER 40S OVER THE
MOUNTAINS WILL BE PUSHING EAST WHERE DEWPOINTS OVER THE EASTERN
PLAINS ARE IN THE UPPER 50S TO LOWER 60S. MOVEMENT ON THESE STORMS
ARE AROUND 15 KTS...SO FLOOD THREAT AT THIS POINT IS THERE IN SOME
SPOTS...BUT OVERALL AREA WIDE IS LOW. TRAINING STORMS COULD
CREATE A PROBLEM. BIGGEST AREA OF CONCERN IS DOWN SOUTH ALONG THE
PALMER DIVIDE AREA AND SOUTHERN FOOTHILLS WITH ANOTHER THREAT UP
OVER LARIMER COUNTY AS CONVECTION IS FORMING A TRAINING LINE.
GUSTY OUTFLOW WINDS FROM THESE STORMS TONIGHT WILL ALSO BE ANOTHER
THREAT...ESPECIALLY AS THE DRIER AIR ALOFT MOVES IN. THERE IS
SLIGHTLY MORE INSTABILITY OUT EAST TOWARDS THE NEBRASKA
BORDER...WHERE STORMS OUT HERE MAY BE ABLE TO STRENGTHEN ENOUGH
FOR SMALL HAIL...OTHERWISE THE SEVERE STRENGTH STORM THREAT IS
LOW.
AS THE SHORTWAVE CONTINUES TO PUSH EAST...QG VERTICAL VELOCITY
WILL SWITCH FROM LIGHT UPWARD TO LIGHT DOWNWARD. THIS COMBINED
WITH THE LOSS OF DAYTIME HEATING WILL ALLOW CONVECTION TO DECREASE
THIS EVENING AND SHOULD BE DIMINISHED BEFORE MIDNIGHT. THERE ARE
HINTS FROM THE HIRES RAP MODEL THAT OUTFLOW FROM STORMS IN
CENTRAL NEBRASKA MAY PUSH BACK INTO COLORADO TONIGHT TO KEEP
CONVECTION GOING....AT THIS POINT DO NOT THINK THIS WILL HAPPEN
WITH CURRENT STRENGTH AND MOTION OF THE STORMS OUT THERE.
UPPER RIDGING WILL MOVE OVERHEAD TOMORROW WITH DRIER PW VALUES
EXPECTED. A WEAK COOL FRONT WILL SLIDE SOUTH IN THE EARLY
AFTERNOON TO KEEP MOST OF THE PLAINS STABLE FOR MUCH OF THE DAY.
WITH MORE SUNLIGHT EXPECTED TOMORROW HOWEVER WILL LEAD TO NEARLY
THE SAME OR SLIGHTLY WARMER TEMPERATURES COMPARED TO TODAY. LESS
CONVECTION IS EXPECTED OVER THE MOUNTAINS...BUT WILL STILL LIKELY
SEE ISOLATED TO SCATTERED ACTIVITY. ONCE THE FRONT PUSHES IN AND
SOME UPSLOPE FLOW ESTABLISHES ITSELF...THERE MAY BE ENOUGH PUSH
FOR SOME ISOLATED ACTIVITY ALONG THE NORTHERN FOOTHILLS AND
ADJACENT PLAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 328 PM MDT TUE AUG 5 2014
SOME THUNDERSTORMS POSSIBLE ACROSS THE AREA WEDNESDAY EVENING...
MAINLY OVER THE FAR NORTHEAST PLAINS AS TAIL END OF MID LEVEL
SHORTWAVE MOVES ACROSS NORTHEAST COLORADO. STORMS COULD PRODUCE
BRIEF HEAVY RAIN FAR EASTERN PLAINS. THE ACTIVITY SHOULD END
AROUND MIDNIGHT AS SUBSIDENCE BEHIND THE PASSING WAVE MOVES OVER
THE AREA. BOUNDARY LAYER WIND AND RH PROGS SUGGEST THE POTENTIAL
FOR LOW CLOUDS ACROSS MUCH OF THE PLAINS...MAINLY EAST OF A
GREELEY TO DENVER LINE OVERNIGHT. AT THIS TIME...THE THREAT FOR
ANY FOG APPEARS LOW AND WILL LEAVE OUT OF THE GRIDS. ON THURSDAY...
THE UPPER RIDGE OVER COLORADO IS EXPECTED TO FLATTEN A BIT AS A
SHORTWAVE MOVES ACROSS WYOMING. CENTER OF THE HIGH TO MOVE TOWARDS
THE TEXAS AND OKLAHOMA PANHANDLES. EASTERLY LOW LEVEL FLOW ACROSS
PLAINS TO PROVIDE UPSLOPE IN AND NEAR THE FOOTHILLS. IN ADDITION...
TAIL END OF THE WAVE LOOKS TO CLIP THE NORTHEAST CORNER. THUS...
SHOULD SEE SOME STORMS DEVELOP DURING THE AFTERNOON WHICH WILL
CONTINUE INTO THE EVENING. BEST CHANCE FOR STORMS TO BE NORTHEAST
OF GREELEY AND DENVER WHERE THE BETTER LOW LEVEL MOISTURE WILL BE
LOCATED. BRIEF HEAVY RAIN POSSIBLE WITH SOME OF THE STORMS OVER
THE FAR NORTHEAST CORNER. TEMPERATURES LOOK TO BE AROUND AVERAGE
MOST AREAS. LATEST MODELS SHOWING THE DEVELOPMENT OF SOME SORT OF
MCS OVER THE FAR EASTERN PLAINS LATE IN THE EVENING...PUSHING INTO
KANSAS OVERNIGHT. SOME LINGERING STORMS POSSIBLE OVER THE FAR
EASTERN PLAINS BEFORE THIS SYSTEM MOVES AWAY FROM THE AREA. FOR
FRIDAY...THERE MAY BE A PUSH OF LOW LEVEL MOISTURE BACK ACROSS
THE PLAINS EARLY IN THE MORNING WITH THE POTENTIAL FOR THE
DEVELOPMENT OF LOW CLOUDS AGAIN. OTHERWISE... MODELS INDICATE
ANOTHER WEAK MID LEVEL SHORTWAVE CLIPPING THE FAR NORTHEAST CORNER
DURING THE AFTERNOON WHICH COULD GENERATE ANOTHER ROUND OF
AFTERNOON AND EVENING THUNDERSTORMS. SOME STORMS POSSIBLE FURTHER
WEST... MAINLY ALONG THE FOOTHILLS WHERE LOW LEVEL SOUTHEAST FLOW
WILL BE IN PLACE. A FEW STORMS COULD LINGER AFTER MIDNIGHT ACROSS
THE FAR PLAINS. ON SATURDAY...MODELS SHOW ELONGATED UPPER HIGH
OVER COLORADO WITH THE CENTER OVER NORTHEAST TEXAS. APPEARS A
BATCH OF MONSOONAL MOISTURE LOOKS TO MOVE ACROSS THE AREA DURING
THE AFTERNOON AND EVENING. THIS MAY RESULT IN A BETTER CHANCE FOR
THUNDERSTORMS MOST LOCATIONS. TEMPERATURES BOTH FRIDAY AND
SATURDAY TO HOVER AROUND AVERAGE.
FOR THE LATER DAYS...SUNDAY THROUGH TUESDAY. UPPER LEVEL RIDGE TO
REMAIN OVER COLORADO THROUGH THE PERIOD. THERE APPEARS TO BE SOME
DECREASE IN THE MONSOONAL MOISTURE THOUGH ENOUGH FOR SOME CHANCE
OF AFTERNOON AND EVENING THUNDERSTORMS. BEST CHANCE TO BE ACROSS
THE MOUNTAINS. BY TUESDAY...BOTH ECMWF AND GFS SHOW THE UPPER
RIDGE FLATTENING AS A SHORTWAVE MOVES ACROSS WYOMING. FLOW ALOFT
TO BECOME MORE WESTERLY...WITH MOST OF THE MONSOONAL MOISTURE
BEING SHUNTED SOUTH OF THE AREA. WILL KEEP A SLIGHT CHANCE OF
STORMS GOING MOST LOCATIONS. TEMPERATURES LOOK TO NEAR OR SLIGHTLY
BELOW AVERAGE.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 730 PM PM MDT TUE AUG 5 2014
THE NEXT BATCH OF STORMS IS JUST CROSSING THE FOOTHILLS OF
JEFFERSON COUNTY AND MOVING EAST NORTHEAST. WE CANNOT RULE OUT
THUNDERSTORMS AT THE AIRPORTS...BUT CENTENNIAL WOULD BE THE MOST
LIKELY TO HAVE A THUNDERSTORM. AREA AIRPORTS SHOULD REMAIN VFR
THROUGH TOMORROW. ON WEDNESDAY THE METRO AREA MAY SEE AN ISOLATED
THUNDERSTORM...BUT FOR NOW WE HAVE NOT MENTIONED THUNDERSTORMS IN
THE AREA TAFS. THE BEST CHANCE OF STORMS WILL BE OVER THE HIGH
COUNTRY AND THE NORTHEAST CORNER.
&&
.HYDROLOGY...
ISSUED AT 730 PM MDT TUE AUG 5 2014
STORMS IN EASTERN COLORADO HAVE PRODUCED RAINFALL RATES UP TO 3
INCHES PER HOUR. THE STORMS ARE MOSTLY TRACKING TO THE EAST...BUT
A FEW STORMS HAVE MERGED...SLOWED DOWN...AND RAINED HEAVILY.
ANOTHER 3 HOURS THE STORMS WILL BE OUT OF COLORADO. THE STORM
COMING OUT OF THE FOOTHILLS IN JEFFERSON COUNTY MAY PRODUCE
A QUICK HALF AN INCH OF RAIN IN 30 MINUTES.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RTG
SHORT TERM...KRIEDERMAN
LONG TERM...D-L
AVIATION...KRIEDERMAN
HYDROLOGY...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
258 PM MDT MON AUG 4 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 213 PM MDT MON AUG 4 2014
.CURRENTLY...STORMS HAVE DEVELOPED OVER THE SOUTHWEST MOUNTAINS
AND EASTERN MOUNTAINS THIS AFTERNOON. STORMS HAVE BEEN PRODUCING
SOME LOCALLY HEAVY DOWNPOURS...WITH THE MAIN CONCERN BEING FOR
THE STORMS TO MOVE SLOWLY OVER THE AREA BURN SCARS. SATELLITE
SOUNDER DATA AND MODELS CONTINUE TO MOIST ATMOSPHERE WITH
PRECIPITABLE WATERS MOSTLY RANGING FROM 0.75 TO ONE INCH OVER THE
MOUNTAINS AND HIGH VALLEYS TO AROUND AN INCH ON THE PLAINS.
.TONIGHT...HRRR AND 4KM NAM MODELS CONTINUE TO SUGGEST THE FIRST
ROUND OF CONVECTION MOVING OFF OF THE MOUNTAINS IT THE LATER
AFTERNOON AND EARLY EVENING. MODELS AND BUFKIT SOUNDINGS CONTINUE
TO SHOW WEAK INSTABILITY ON THE PLAINS THIS EVENING...BECOMING
MORE CAPPED FURTHER EAST. CONVECTION SHOULD WEAKEN AS IT MOVES
EAST DURING THE EVENING...AND MAINTAINED THE SILENT POPS NEAR THE
KANSAS BORDER. HRRR SUGGESTS THE NEXT DISTURBANCE...AS SEEN IN
CONVECTION OVER NORTHWEST NEW MEXICO...WILL PASS MOVE NORTHEAST
ACROSS THE CWA DURING THE EVENING REACHING THE EASTERN MOUNTAINS AFTER
MIDNIGHT. SUSPECT ATMOSPHERE WILL BE STABLE BY MIDNIGHT...AND
ONLY MAINTAINED POPS OVER THE WESTERN MOUNTAINS AT 06Z.
.TUESDAY...PORTION OF SHORTWAVE SPINNING OVER NEVADA WILL CROSS
THE CWA DURING THE AFTERNOON. PRECIPITABLE WATER VALUES WILL
REMAIN AROUND AN INCH OVER THE MAINS AND 0.75 TO ONE INCH OVER
THE MOUNTAINS. WITH THE SHORTWAVE APPROACHING...STORMS WILL
DEVELOP AN HOUR TO TWO EARLIER THAN MONDAY. MAIN THREATS AGAIN
WILL BE LOCALLY HEAVY DOWNPOURS..ESPECIALLY ON AREA BURN SCARS.
WINDS ALOFT WILL INCREASE SO STORMS WILL BE MOVING SLIGHTLY
FASTER. BEHIND THE TROUGH...DRYING OCCURS IN THE MID AND UPPER
LEVELS BY LATER AFTERNOON. -PGW--
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 213 PM MDT MON AUG 4 2014
TUE NIGHT...
DISTURBANCE ALOFT SHOULD BE OVER EASTERN PLAINS WITH DRIER AIR
GRADUALLY MOVING INTO THE MTNS. BEST CHANCE OF PRECIP WILL BE OVER
THE FAR E PLAINS DURING THE EVENING...WITH ISOLD POPS (AT BEST) OVER
THE CONTDVD.
WED...
SHOULD BE A RATHER DRY DAY AS DRIER AIR IS FCST TO BE OVER THE MTNS
WITH THE DRIER ATMOSPHERE CREEPING INTO THE PLAINS. IN
ADDITION...RIDGING AT MIDLVLS WILL BE OCCURRING OVER THE REGION.
BELIEVE POPS THIS DAT WILL BE ISOLD AT BEST...AND WILL BE OVER THE
HIGHEST TRRN. MAX TEMPS THIS DAY WILL BE WARM WITH HIGHS IN THE 90S
MOST OF THE PLAINS.
THU...
THIS DAY WILL BE TRICKY. A COOL FRONT WILL MOVE ACROSS THE PLAINS
EARLY IN THE DAY. CONVECTION WILL FIRE ACROSS THE HIGH PLAINS...BUT
HOW FAR SOUTH WILL IT GET? GFS IS FARTHEST NORTH WITH BRUNT OF
ACTIVITY OVER FAR NE CO...WHILE NAM AND EC ARE A BIT FARTHER SOUTH
WITH THE ACTIVITY EXTENDING DOWN INTO EAST CENTRAL CO. FOR NOW HAVE
PAINTED ISOLD POPS OVER THE ENTIRE REGION DURING THE AFTERNOON AND
EVENING...BUT MAY NEED HIGHER POPS OVER THE FAR E PLAINS IN LATER
UPDATES. MAX TEMPS ON THE PLAINS SHOULD BE AROUND 90F THIS DAY.
MTNS SHOULD SEE ONLY ISOLD POPS.
FRI...
EC AND GFS IN DISAGREEMENT THIS DAY. BOTH BRING DOWN ANOTHER
BOUNDARY WITH UPSLOPE FLOW. GFS APPEARS MORE STABLE AND KEEPS WX
DRIER OVER OUR REGION WHILE EC A BIT MORE WETTER OVER THE FAR E
PLAINS. FOR NOW KEPT ONLY ISOLD POPS OVER E PLAINS WITH ISOLD PRECIP
OVER S MTN TOPS. REST OF MTNS DRY. MAX TEMPS ONCE AGAIN ABOUT 90F
MOST OF PLAINS.
WEEKEND...
SIMULATIONS SHOW A BIT BETTER CHANCE OF PRECIP ALL AREAS AS MONSOON
PLUME WILL LIKELY REDEVELOP OVER THE SW...WITH MOISTURE ADVECTING IN
FROM E AZ AND W NM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 213 PM MDT MON AUG 4 2014
THUNDERSTORMS WILL CONTINUE IN THE VICINITY OF THE TAF SITES
UNTIL EARLY EVENING. ANOTHER DISTURBANCE MOVING ACROSS THE REGION
COULD MAINTAIN SOME SHOWERS WELL INTO THE EVENING OVER THE
MOUNTAINS AND HIGH VALLEYS. ON TUESDAY...AN APPROACHING
DISTURBANCE WILL HELP DEVELOP CONVECTION AN HOUR OR TWO EARLIER
THAN ON MONDAY...WITH THE POTENTIAL FOR STORMS NEAR KALS BEFORE
18Z. STORMS WILL SPREAD INTO KPUB AND KCOS BY EARLY AFTERNOON.
LOCALLY HEAVY RAIN WILL BE MAIN THREATS WITH CONVECTION WITH
REDUCED CEILINGS AND VISIBILITIES POSSIBLE. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...PGW
LONG TERM...HODANISH
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1200 PM MDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1158 AM MDT MON AUG 4 2014
THUNDERSTORMS ARE STARTING TO DEVELOP OVER THE CONTINENTAL DIVIDE.
PLENTY OF MONSOON MOISTURE MOVING NORTHWARD AHEAD OF THE
DISTURBANCE IN ARIZONA AND UTAH. ALL SHORT RANGE MODELS SHOW THE
STORMS...WHICH ARE JUST DEVELOPING OVER THE CONTINENTAL DIVIDE
REGION...SHOULD MOVE EASTWARD IN THE AFTERNOON. MODELS CONTINUE TO
AGREE ON THE FIRST ROUND OF THUNDERSTORMS BEING OVER THE EASTERN
MOUNTAINS AND NEARBY PLAINS BY AROUND 2PM...AND CONTINUING TO
6PM. PLENTY OF MOISTURE REMAINS OVER THE REGION WITH MODELS
SUGGESTING PRECIPITABLE WATERS AROUND AN INCH OVER THE PLAINS AND
MUCH OF THE INTERSTATE 25 CORRIDOR. STORMS OVER WESTERN COLORADO
ARE MOVING AROUND 20 KNOTS. MAIN THREAT FOR FLASH FLOODING WILL BE
OVER THE AREA BURN SCARS...WHERE LOCALLY HEAVY DOWNPOURS COULD
RESULT IN FLASH FLOODING. LATEST MODELS AND BUFKIT SOUNDING
SUGGEST THE STORMS COULD MOVE EASTWARD OFF OF THE MOUNTAINS AND
ONTO THE EASTERN PLAINS DURING THE LATE AFTERNOON AND INTO THE
EVENING. EXTENDED THE EASTWARD EXTENT OF POPS THIS EVENING...BUT
HAVE ONLY SILENT POPS IN COUNTIES NEAR THE KANSAS BORDER.
A SECOND DISTURBANCE WILL MOVE ACROSS THE MOUNTAINS DURING THE
EVENING. THIS COULD KEEP SOME SHOWERS AND STORMS CONTINUING OVER
THE MOUNTAINS WELL INTO THE EVENING. WILL HAVE TO WATCH FOR
LOCALLY HEAVY DOWNPOURS WITH FLASH FLOODING OVER THE BURN SCARS
INT HE EVENING...BUT SUSPECT THREAT IS LESS THAN DURING THE
AFTERNOON BECAUSE OF THE INCREASED STABILITY FROM EARLIER STORMS.
ON TUESDAY...MAIN DISTURBANCE WILL PASS OVER THE CWA DURING THE
LATE MORNING AND INTO THE AFTERNOON. STORMS COULD BEGIN EARLIER
TOMORROW. STORMS COULD PRODUCE LOCALLY HEAVY DOWNPOURS...WHICH
WILL CAUSE FLASH FLOODING CONCERNS FOR AREA BURN SCARS. DRIER AIR
WILL MOVE INTO THE REGION FROM THE WEST...WHICH COULD END
CONVECTION EARLIER TOMORROW. --PGW--
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM MDT MON AUG 4 2014
AN UPR RIDGE WL REMAIN OVR THE AREA TODAY...BUT WL SHIFT A LITTLE
EASTWARD TONIGHT AS A SHORTWAVE TROF MOVES INTO UT AND WRN CO. THE
HRRR AND WRF SHOW PCPN MOVING OVR THE SAN JUAN AND LA GARITA MTN
AREAS THIS MORNING AND POSSIBLY INTO THE CENTRAL MTNS. RADAR LOOP
SHOWS ECHOES OVR WRN CO THIS MORNING...SO THAT SEEMS REASONABLE.
AROUND NOON...THE WRF AND HRRR DEVELOP SOME VERY ISOLD PCPN OVR SOME
OF THE ERN MTNS. THE MODELS THEN INCREASE PCPN COVERAGE OVR ALL THE
MTNS AREAS THRU THE AFTERNOON HOURS...WITH SOME PCPN ALSO SPREADING
OVR THE SAN LUIS VALLEY. IN THE LATE AFTERNOON...THEY SHOW SOME
ISOLD PCPN MAKING OVR PORTIONS OF THE I-25 CORRIDOR...MAINLY OVR EL
PASO COUNTY AND OVR HUERFANO AND WRN LAS ANIMAS COUNTIES. IN THE
EVENING HOURS THE NAM12 MOVES A LINE OVR PCPN EASTWARD ACRS THE SERN
PLAINS...WHILE THE WRF AND RAP MAINLY JUST KEEPS SOME ISOLD PCPN
WEST OF A LINE FROM CROWLEY...OTERO AND ERN LAS ANIMAS COUNTIES.
HAVE DECIDED TO NOT FOLLOW THE NAMS SOLUTION AND WL THEREFORE KEEP
THE FAR SERN PLAINS DRY. MUCH OF THE PCPN THEN DIES OFF BEFORE
MIDNIGHT...BUT THEN AS A SHORTWAVE TROF MOVES INTO WRN CO LATE
TONIGHT...INCREASED PCPN CHANCES ARE AGAIN EXPECTED OVR THE SWRN
MTNS. HIGH TEMPS TODAY SHOULD BE AROUND TO JUST SLIGHTLY BELOW
AVERAGE IN MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM MDT MON AUG 4 2014
TUESDAY-TUESDAY NIGHT...GENERALLY WEAK WESTERLY FLOW ALOFT PROGGED
ACROSS THE REGION TUESDAY WITH A MINOR EMBEDDED SHORT WAVE
TRANSLATING THROUGH THE FLOW. LATEST MODELS REMAIN CONSISTENT WITH
DRIER AIR EMBEDDED WITHIN THE WESTERLY FLOW ALOFT SLOWLY FILTERING
ACROSS THE AREA TUESDAY...WITH PWATS PROGGED BETWEEN 1/2 INCH ACROSS
WESTERN COLORADO TO AROUND 1 1/4 INCHES ACROSS THE FAR SE PLAINS.
DESPITE THE DRYING ALOFT...SHOULD SEE SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS THE HIGHER TERRAIN LATE TUESDAY
MORNING WITH INCREASED UVV ASSOCIATED WITH THE PASSING WAVE. STORMS
TO SPREAD EAST ACROSS THE ADJACENT PLAINS AND INTO THE FAR SE PLAINS
THROUGH THE AFTERNOON AND EVENING HOURS. LOCALLY HEAVY RAIN TO
REMAIN POSSIBLE...ALONG WITH POSSIBLE FLASH FLOODING IF THESE STORMS
MOVE OVER AREA BURN SCARS. TEMPERATURES AT OR SLIGHTLY COOLER THAN
SEASONAL AVERAGES CAN BE EXPECTED WITH THE EXPECTED CONVECTIVE CLOUD
COVER.
WEDNESDAY-THURSDAY NIGHT...WEAK TO MODERATE WEST TO SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE AREA WEDNESDAY AND THURSDAY AS ANOTHER
EMBEDDED SHORT WAVE TRANSLATES ACROSS THE GREAT BASIN AND INTO THE
NORTHERN ROCKIES. DRIER AIR ALOFT CONTINUES TO MOVE INTO THE STATE
WITH MODEL SOUNDINGS INDICATING DEW PTS MIXING OUT INTO THE UPPER
30S AND UPPER 40S ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS AND
REMAINING GENERALLY IN THE 50S ACROSS THE FAR SE PLAINS. THERE IS
ENOUGH MOISTURE REMAINING IN PLACE TO WORK WITH LATE SUMMER SUNSHINE
FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS BOTH DAYS...WITH THE BEST COVERAGE OVER AND NEAR THE
HIGHER TERRAIN. A WEAK COLD FRONT PROGGED TO BACK INTO EASTERN
COLORADO WEDNESDAY MORNING...LOOKS TO HAVE LITTLE AFFECT ON
TEMPERATURES WITH READINGS AROUND SEASONAL AVERAGES EXPECTED. LATEST
MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ELEVATED CONVECTION
ACROSS THE FAR SE PLAINS INTO WESTERN KANSAS THURSDAY EVENING AND
HAVE KEPT SLIGHT POPS IN TACT.
FRIDAY-SUNDAY...UPPER RIDGING BUILDS BACK ACROSS THE STATE WITH
MONSOONAL PLUME SLOWLY INCREASING ACROSS THE AREA. THIS...ALONG WITH
ANOTHER POSSIBLE WEAK COLD FRONT SLIDING ACROSS THE EASTERN
PLAINS...WILL ALLOW FOR INCREASING COVERAGE OF STORMS INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1158 AM MDT MON AUG 4 2014
CONVECTION WILL DEVELOP OVER THE MOUNTAINS DURING THE EARLY
AFTERNOON AND MOVE INTO THE INTERSTATE 25 CORRIDOR BY LATE IN THE
AFTERNOON. ADD VCTS TO REMAINING TAFS FOR THIS AFTERNOON AND EARLY
EVENING TO ACCOUNT FOR SCATTERED COVERAGE OF CONVECTION. A SECOND
DISTURBANCE WILL PASS OVER THE REGION DURING THE EVENING. GIVEN
ATMOSPHERE WILL BE MORE STABLE...ONLY ADDED SOME VCSH TO
TAFS...AS BELIEVE THREAT FOR THUNDERSTORMS WILL BE LOW. ON
TUESDAY...A DISTURBANCE WILL APPROACH THE REGION BY LATE
MORNING...WITH AN EARLIER START FOR DIURNAL CONVECTION. --PGW--
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...PGW
SHORT TERM...28
LONG TERM...MW
AVIATION...PGW
AREA FORECAST DISCUSSION
NWS PUEBLO CO
356 AM MDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM MDT MON AUG 4 2014
AN UPR RIDGE WL REMAIN OVR THE AREA TODAY...BUT WL SHIFT A LITTLE
EASTWARD TONIGHT AS A SHORTWAVE TROF MOVES INTO UT AND WRN CO. THE
HRRR AND WRF SHOW PCPN MOVING OVR THE SAN JUAN AND LA GARITA MTN
AREAS THIS MORNING AND POSSIBLY INTO THE CENTRAL MTNS. RADAR LOOP
SHOWS ECHOES OVR WRN CO THIS MORNING...SO THAT SEEMS REASONABLE.
AROUND NOON...THE WRF AND HRRR DEVELOP SOME VERY ISOLD PCPN OVR SOME
OF THE ERN MTNS. THE MODELS THEN INCREASE PCPN COVERAGE OVR ALL THE
MTNS AREAS THRU THE AFTERNOON HOURS...WITH SOME PCPN ALSO SPREADING
OVR THE SAN LUIS VALLEY. IN THE LATE AFTERNOON...THEY SHOW SOME
ISOLD PCPN MAKING OVR PORTIONS OF THE I-25 CORRIDOR...MAINLY OVR EL
PASO COUNTY AND OVR HUERFANO AND WRN LAS ANIMAS COUNTIES. IN THE
EVENING HOURS THE NAM12 MOVES A LINE OVR PCPN EASTWARD ACRS THE SERN
PLAINS...WHILE THE WRF AND RAP MAINLY JUST KEEPS SOME ISOLD PCPN
WEST OF A LINE FROM CROWLEY...OTERO AND ERN LAS ANIMAS COUNTIES.
HAVE DECIDED TO NOT FOLLOW THE NAMS SOLUTION AND WL THEREFORE KEEP
THE FAR SERN PLAINS DRY. MUCH OF THE PCPN THEN DIES OFF BEFORE
MIDNIGHT...BUT THEN AS A SHORTWAVE TROF MOVES INTO WRN CO LATE
TONIGHT...INCREASED PCPN CHANCES ARE AGAIN EXPECTED OVR THE SWRN
MTNS. HIGH TEMPS TODAY SHOULD BE AROUND TO JUST SLIGHTLY BELOW
AVERAGE IN MOST LOCATIONS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 356 AM MDT MON AUG 4 2014
TUESDAY-TUESDAY NIGHT...GENERALLY WEAK WESTERLY FLOW ALOFT PROGGED
ACROSS THE REGION TUESDAY WITH A MINOR EMBEDDED SHORT WAVE
TRANSLATING THROUGH THE FLOW. LATEST MODELS REMAIN CONSISTENT WITH
DRIER AIR EMBEDDED WITHIN THE WESTERLY FLOW ALOFT SLOWLY FILTERING
ACROSS THE AREA TUESDAY...WITH PWATS PROGGED BETWEEN 1/2 INCH ACROSS
WESTERN COLORADO TO AROUND 1 1/4 INCHES ACROSS THE FAR SE PLAINS.
DESPITE THE DRYING ALOFT...SHOULD SEE SCATTERED SHOWERS AND
THUNDERSTORMS DEVELOPING ACROSS THE HIGHER TERRAIN LATE TUESDAY
MORNING WITH INCREASED UVV ASSOCIATED WITH THE PASSING WAVE. STORMS
TO SPREAD EAST ACROSS THE ADJACENT PLAINS AND INTO THE FAR SE PLAINS
THROUGH THE AFTERNOON AND EVENING HOURS. LOCALLY HEAVY RAIN TO
REMAIN POSSIBLE...ALONG WITH POSSIBLE FLASH FLOODING IF THESE STORMS
MOVE OVER AREA BURN SCARS. TEMPERATURES AT OR SLIGHTLY COOLER THAN
SEASONAL AVERAGES CAN BE EXPECTED WITH THE EXPECTED CONVECTIVE CLOUD
COVER.
WEDNESDAY-THURSDAY NIGHT...WEAK TO MODERATE WEST TO SOUTHWEST FLOW
ALOFT CONTINUES ACROSS THE AREA WEDNESDAY AND THURSDAY AS ANOTHER
EMBEDDED SHORT WAVE TRANSLATES ACROSS THE GREAT BASIN AND INTO THE
NORTHERN ROCKIES. DRIER AIR ALOFT CONTINUES TO MOVE INTO THE STATE
WITH MODEL SOUNDINGS INDICATING DEW PTS MIXING OUT INTO THE UPPER
30S AND UPPER 40S ACROSS THE HIGHER TERRAIN AND ADJACENT PLAINS AND
REMAINING GENERALLY IN THE 50S ACROSS THE FAR SE PLAINS. THERE IS
ENOUGH MOISTURE REMAINING IN PLACE TO WORK WITH LATE SUMMER SUNSHINE
FOR ISOLATED TO SCATTERED AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS BOTH DAYS...WITH THE BEST COVERAGE OVER AND NEAR THE
HIGHER TERRAIN. A WEAK COLD FRONT PROGGED TO BACK INTO EASTERN
COLORADO WEDNESDAY MORNING...LOOKS TO HAVE LITTLE AFFECT ON
TEMPERATURES WITH READINGS AROUND SEASONAL AVERAGES EXPECTED. LATEST
MODELS CONTINUE TO INDICATE THE POTENTIAL FOR ELEVATED CONVECTION
ACROSS THE FAR SE PLAINS INTO WESTERN KANSAS THURSDAY EVENING AND
HAVE KEPT SLIGHT POPS IN TACT.
FRIDAY-SUNDAY...UPPER RIDGING BUILDS BACK ACROSS THE STATE WITH
MONSOONAL PLUME SLOWLY INCREASING ACROSS THE AREA. THIS...ALONG WITH
ANOTHER POSSIBLE WEAK COLD FRONT SLIDING ACROSS THE EASTERN
PLAINS...WILL ALLOW FOR INCREASING COVERAGE OF STORMS INTO NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 356 AM MDT MON AUG 4 2014
VFR CONDITIONS ARE EXPECTED AT KCOS...KPUB AND KALS TODAY AND
TONIGHT. KCOS AND KALS MAY SEE TSTMS IN THE VCNTY AFTER 20Z THROUGH
ABOUT 03Z. KPUB COULD ALSO SEE TSTMS IN THE VCNTY AFT 23Z...BUT
CONFIDENCE IN THIS OCCURRING IS LOW.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...28
LONG TERM...MW
AVIATION...28
AREA FORECAST DISCUSSION
NWS ALBANY NY
730 PM EDT TUE AUG 5 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION TONIGHT. A SECONDARY COLD FRONT
WILL CROSS THE REGION ON THURSDAY. HIGH PRESSURE WILL SETTLED IN
FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AS OF 500 PM EDT...WIDELY SCATTERED THUNDERSTORMS WERE ACROSS OUR
REGION...MOST NUMEROUS ACROSS WASHINGTON COUNTY WHERE EARLIER A
SEVERE THUNDERSTORM WARNING WAS ISSUED. THIS STORM PRODUCED WIND
DAMAGE NEAR HEWITT`S LANDING.
MEANWHILE...A CLUSTER OF SHOWERS AND THUNDERSTORMS OVER WESTERN AND
CENTRAL NEW YORK...ASSOCIATED WITH A COLD FRONT (ENHANCING SURFACE
CONVERGENCE) AND THE EXIT REGION OF THE UPPER LEVEL JET (ENHANCING
DIVERGENCE ALOFT) ...CONTINUE TO MOVE STEADILY EAST.
IT LOOKS AS IF THIS AREA OF RAIN MIGHT STAY JUST FROM THE CAPITAL
REGION SOUTHWARD. THE LATEST HRRR HAS TRENDED A LITTLE SLOWER AND
SOUTH WITH THE HEAVIEST RAINFALL...MAINLY JUST SOUTH OF THE CAPITAL
REGION THIS EVENING. WILL CONTINUE CHANCE POPS THROUGH ALL OF THE
EVENING...INCLUDING THUNDER.
GIVEN INSTABILITY AROUND 2000 J/KG...LAPSE RATES OVER 6.0 C/KM...AND
ALREADY HISTORY OF ONE DAMAGING WIND THUNDERSTORM AND SMALL
HAIL...WE WENT AHEAD AND ADDED QUALIFIER TO THE THUNDERSTORMS
THROUGH THIS EVENING..."MIGHT CONTAIN GUSTY WINDS AND SMALL HAIL."
SO THROUGH EVENING...EXPECT SCATTERED SHOWERS AND THUNDERSTORMS
(MEANING NOT EVERYONE WILL RECEIVE MEASURABLE RAINFALL...BUT SOME
AREAS GET A GOOD SOAKING RAIN AND THUNDERSTORM ACTIVITY). IT WILL
REMAIN QUITE WARM AND SOMEWHAT HUMID WITH TEMPERATURES IN THE MID TO
UPPER 80S...COOLING TO THE 70S LATER THIS EVENING...ESPECIALLY WHERE
RAINFALL COOLS THE COLUMN.
THE WIND WILL BE VARIABLE SHIFTING TO NORTHWESTERLY LATER TONIGHT
BEHIND THE FRONT GENERALLY 10 MPH OR LESS.
OVERNIGHT...THE FRONT WILL LIKELY STILL BE SOMEWHERE TO THE SOUTH OF
THE CAPITAL REGION. SHOWERS AND THUNDERSTORMS WILL DIMINISH ALL
TOGETHER AS UPPER LEVEL FORCING (THE JET EXIT REGION) LIFTS NORTH
AND INSTABILITY DISSIPATES.
THE SKY WILL PARTIALLY CLEAR. THIS MIGHT ALLOW FOR SOME FOG TO FORM.
HOWEVER...THERE MIGHT BE JUST ENOUGH OF A BREEZE TO PREVENT THIS.
FOR NOW...DECIDED NOT INCLUDE ANY FOG TONIGHT PENDING HOW MUCH
RAINFALLS AND MAKES THE GROUND WET.
OVERNIGHT LOWS WILL GENERALLY RANGED FROM THE MID 50S NORTHWEST AND
LOWER 60S CAPITAL REGION SOUTHWARD.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH FRIDAY NIGHT/...
SOMEWHAT DRIER AND COOLER AIR WILL FILTER INTO THE REGION ON
WEDNESDAY BEHIND THE COLD FRONT. HOWEVER...THE ACTUAL FRONT WILL
LIKELY STILL BE JUST TO THE SOUTH OF THE CAPITAL REGION. THERE COULD
BE A RENEWAL OF SHOWER AND THUNDERSTORM ACTIVITY MAINLY SOUTH OF THE
CAPITAL REGION AS SOON AS WE GET HEATING...MAINLY MIDDAY AND
AFTERNOON. WILL CONTINUE WITH SLIGHT CHANCES OF SHOWERS AND
THUNDERSTORMS ALBANY NORTH...LOW CHANCES SOUTH ON WEDNESDAY.
WITH LINGERING CLOUDS AND WEAK COOL AIR ADVECTION...WENT WITH THE
LOWER END OF GUIDANCE FOR HIGH TEMPERATURES. LOOK FOR HIGHS
WEDNESDAY GENERALLY IN THE MID TO UPPER 70S (MORE CLOUDS
SOUTH).
ANY AND ALL CONVECTION WILL DIMINISH WEDNESDAY NIGHT. WE WILL BE
LEFT WITH A MAINLY CLEAR SKY AND PERHAPS SOME PATCHY FOG. DID PUT
PATCHY FOG IN THE GRIDS TOMORROW NIGHT AS THE WIND LOOKS CALMER AND
LESS IN THE WAY OF CLOUDS. TEMPERATURES WILL DIP INTO 50S.
THURSDAY...IT LOOKS AS IF A SECONDARY COLD FRONT AND UPPER LEVEL
ENERGY WILL WORK THROUGH TO PRODUCE SOME MORE SCATTERED SHOWERS AND
POSSIBLY AFTERNOON THUNDERSTORMS. THE ACTIVITY LOOKS SCATTERED
ACROSS THE HIGHER ELEVATIONS AND ISOLATED CAPITAL REGION
SOUTHWARD.
THE DAY WILL START OUT MAINLY SUNNY...BUT CLOUDS AND THE WIDELY
SCATTERED SHOWERS WILL QUICKLY FOLLOW BY AFTERNOON. TEMPERATURES
WILL BE SIMILAR TO WEDNESDAY...MAYBE A POINT OR TWO LOWER.
IT SHOULD CLEAR OUT THURSDAY NIGHT AND BECOME RATHER COOL. OVERNIGHT
LOWS WILL DIP INTO THE LOWER TO MID 50S ALBANY SOUTHWARD...MID TO
UPPER 40S FURTHER NORTH.
FRIDAY LOOKS LIKE A WINNER WEATHER WISE AS HIGH PRESSURE FROM CANADA
BEGINS TO BUILD IN. IT SHOULD BE MOSTLY SUNNY (FEW-SCT FAIR WEATHER
CU) AND TEMPERATURES AROUND 80 IN THE VALLEYS...MID TO UPPER 70S
HIGHER TERRAIN.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
EXCEPT FOR POSSIBLY THE LAST DAY...THIS WILL BE A STRETCH OF DRY
WEATHER AND SEASONABLE TEMPERATURES. HIGH PRESSURE WILL RULE THE
ROOST THROUGHOUT. ON TUESDAY...A COLD FRONT FROM THE NORTHWEST MAY
MAKE IT CLOSE ENOUGH TO BRING SHOWERS AND THUNDERSTORMS TO THE
ADIRONDACKS. RELATIVE HUMIDITIES WILL INCREASE ONLY SLIGHTLY EACH
DAY.
HIGH TEMPERATURES EACH DAY WILL RANGE FROM THE LOWER AND MID 70S IN
THE HIGHEST ELEVATIONS...TO THE LOWER AND MID 80S IN THE VALLEYS.
LOW TEMPERATURES WILL GRADUALLY MODERATE SLIGHTLY...WITH LOWS FRIDAY
NIGHT FROM MOSTLY THE UPPER 40S IN THE HIGH MOUNTAIN PEAKS...TO THE
MID AND UPPER 50S IN THE VALLEYS. BY MONDAY NIGHT...LOWS WILL RANGE
FROM THE LOWER AND MID 50S IN THE MOUNTAINS...TO THE LOWER 60S IN
THE VALLEYS. FOR THIS PERIOD...NORMAL HIGHS IN ALBANY ARE IN THE
LOWER 80S...NORMAL LOWS...AROUND 60 DEGREES.
&&
.AVIATION /23Z TUESDAY THROUGH SUNDAY/...
THUNDERSTORMS HAVE IMPACT MAINLY KALB LATE IN THE AFTERNOON AND
EARLY EVENING. AS OF 2515Z...RADARS INDICATE MOST OF THE ACTIVITY
HAS WEAKENED AND MOVE EAST OF THAT AIRPORT. THUNDERSTORMS WERE IN
THE AREA OF KPSF BUT AGAIN HAVE WEAKENED. WE DID PLACE A TEMPO FOR
THUNDERSTORM REDUCING CONDITIONS TO MVFR CONDITIONS THROUGH 01Z.
THUNDERSTORMS COULD IMPACT KPOU BUT SINCE THEY HAVE WEAKENED SO MUCH
JUST WENT WITH A VCTS THROUGH 01Z. KGFL HAS MISSED MOST OF THE
ACTION AND LOOKS AS IF IT WILL DO SO.
FOG POTENTIAL IS THERE TONIGHT...ESPECIALLY AT THOSE AIRPORTS WHERE
RAIN HAD FALLEN. SO FAR...KALB LEADS THE PACK. AT THE SAME TIME
HOWEVER...HIGH CLOUDS AND WEAK COLD AIR ADVECTION COULD MITIGATE FOG
FORMATION A LITTLE. FOR NOW...AT KALB TRENDED UPWARD FROM VFR (MIFG)
TO 3SM BR AFTER 08Z TONIGHT. STILL KEPT IFR FOG IN THE TAF AT KGFL
AND CONTINUE IT AT KPSF SINCE IN ALL LIKELIHOOD THEY WILL GET WET
SHORTLY AFTER 00Z. AT KPOU...THE JURY IS STILL OUT...BUT SINCE
SHOWERS COULD WET THE GROUND THERE...WILL LEAVE THE MVFR BR IN AFTER
08Z.
ALL FOG SHOULD DISSIPATE BY 12Z...LEAVING US WITH A MAINLY VFR DAY
WEDNESDAY...ALTHOUGH WE COULD HAVE SCT-BKN CLOUDS AT 5000 FEET AGL
(4000 FEET AGL AT KPSF).
THERE MIGHT BE SOME SHOWERS OR THUNDERSTORMS AROUND DURING THE
AFTERNOON HOURS.FOR NOW DUE TO LOWER THAN 30 PERCENT PROBABILITY
THAT ANY STORM WOULD REDUCE CONDITIONS TO ANYTHING LOWER THAN
VFR...JUST USED VCSH AT ALL THE TAFS (EXCEPT KGFL) SINCE THE CHANCES
WERE EVEN LOWER AT KGFL.
LIGHT AND VARIABLE WIND WILL BECOME NORTH OR NORTHWEST 5-10KTS ON
WEDNESDAY.
OUTLOOK...
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...TSRA.
THURSDAY NIGHT THROUGH SUNDAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH EVENING...WITH ABOUT
HALF THE PLACES RECEIVING A QUARTER INCH OR MORE OF RAINFALL...BUT
AREAS NOT RECEIVING ANY.
THESE STORMS WILL BE ASSOCIATED WITH A SLOW MOVING COLD FRONT THAT
WILL STILL BE WORKING THROUGH AREAS SOUTH OF ALBANY ON
WEDNESDAY...THUS CONTINUING THE CHANCES FOR SHOWERS AND
THUNDERSTORMS.
COVERAGE ON WEDNESDAY WILL BE MORE LIMITED THAN TODAY.
A SECONDARY COLD FRONT COULD TRIGGER A FEW MORE SHOWERS AND
THUNDERSTORMS ON THURSDAY...MAINLY NORTH AND WEST OF THE CAPITAL
REGION.
AFTER THAT...IT LOOKS LIKE DRY WEATHER ON THE WEEKEND INTO EARLY
NEXT WEEK WITH A NORMAL RECOVERY EACH NIGHT AND RH VALUES GENERALLY
35-45 PERCENT EACH AFTERNOON.
&&
.HYDROLOGY...
SCATTERED SHOWERS AND THUNDERSTORMS WILL BE WORKING THROUGH THE
REGION THROUGH THE EVENING HOURS. SOME OF THE STORMS HAVE BEEN SLOW
MOVING...AND BACKBUILDING...CAPABLE OF PRODUCING RAINFALL IN EXCESS
OF AN INCH PER HOUR. LOCALIZED PONDING OF WATER IS POSSIBLE THIS
EVENING WITH THESE TYPE OF STORMS...BUT OVERALL...NO SIGNIFICANT
HYDRO PROBLEMS ARE ANTICIPATED.
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS COULD LINGER FROM THE
CAPITAL REGION SOUTHWARD TOMORROW BUT ANY EXCESS RAINFALL WILL
PROBABLY BE EVEN MORE LIMITED.
ANOTHER COLD FRONT COULD TRIGGER A FEW MORE SHOWERS AND
THUNDERSTORMS MAINLY NORTH ON THURSDAY...GENERALLY WITH AN AVERAGE
RAINFALL BASIN OF A QUARTER INCH OR LESS.
AFTER THAT...DRY WEATHER EXPECTED FRIDAY THROUGH EARLY NEXT WEEK.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...ELH
AVIATION...HWJIV
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
410 AM EDT MON AUG 4 2014
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A RAGGED LOOKING UPPER
LEVEL PATTERN OVER THE CONUS EARLY THIS MORNING. WESTERN RIDGE HAS
BEEN ERODED SOMEWHAT ON ITS WESTERN PERIPHERY DURING THE PAST 24
HOURS AS POTENT ENERGY/CLOSED LOW IMPULSE HAS MIGRATED NORTHWARD
FROM THE BAJA REGION INTO THE SOUTHWESTERN STATES. NORTHERN STREAM
FLOW STILL COMES AROUND THE TOP OF THIS RIDGE AND DIVES BACK
SOUTHWARD THROUGH THE UPPER MIDWEST INTO WHAT HAS BECOME A VERY
STUBBORN EASTERN CONUS UPPER TROUGH. THIS TROUGH EXTENDS DOWN TO THE
NORTHEASTERN GULF COAST BEFORE THE FLOW TURNS BACK NORTHWARD OVER
THE EASTERN SEABOARD. THE PATTERN CURRENTLY OVER OUR HEADS IS RATHER
MESSY AND COMPLEX. THE MAIN EASTERN TROUGH IS NOT DIRECTLY IMPACTING
OUR REGION...HOWEVER A WEAK IMPULSE THAT ARRIVED FROM THE EAST ON
SUNDAY IS NOW SPINNING OVER THE SOUTHERN HALF OF THE STATE...AND HAS
PROVIDED THE SUPPORT AND PERSISTENT LIFT FOR A WET OVERNIGHT OVER
THE SOUTHERN PORTION OF THE STATE. ONLY IN THE PAST HOUR OR TWO
HAVE WE FINALLY SEEN ALL THIS SHOWER ACTIVITY EXIT SOUTH OF OUR
ZONES.
THE MAIN EASTERN UPPER TROUGH WILL EVENTUALLY HELP REMOVE THIS
IMPULSE THROUGH MONDAY AND MONDAY NIGHT AS IT TENDS TO ABSORB THE
ENERGY AND EJECT IT OFF TO THE NORTHEAST. AT THE SAME TIME...THE
UPPER ENERGY ASSOCIATED WITH TROPICAL STORM BERTHA WILL BE LIFTING
NORTHWARD INTO THE WHOLE MIX. SO AS YOU CAN SEE...THE SYNOPTIC
PATTERN AND EVOLUTION OVER THE NEXT 24 HOURS IS KIND OF COMPLEX.
HOWEVER...LUCKY FOR US...THIS MERGER OF ENERGY WILL ALL BE TAKING
PLACE OFF TO THE EAST/NE OF JACKSONVILLE TONIGHT/TUESDAY AND
RAPIDLY HEADING FURTHER OUT TO SEA. THEREFORE...DO NOT ANTICIPATE
ANY ADVERSE IMPACTS FOR OUR FORECAST AREA. PHEW! CLOSE ONE.
AT THE SURFACE...A BROAD SURFACE REFLECTION LOW ASSOCIATED WITH THE
IMPULSE OVERHEAD IS LOCATED OVER THE SOUTHERN/CENTRAL FL PENINSULA.
THIS IS A VERY WEAK LOW WITH PRESSURES ONLY AROUND 1012MB.
&&
.SHORT TERM (TODAY THROUGH TUESDAY)...
ANOTHER DAY WITH AN ILL-DEFINED AND MESSY PATTERN ALOFT BEFORE A
MORE TYPICAL SUMMER PATTERN BEGINS TO RE-EMERGES FOR THE MIDDLE
PORTION OF THE WEEK.
WEAK IMPULSE ALOFT AND ITS ASSOCIATED SURFACE REFLECTION IS SHOWN BY
ALL AVAILABLE NWP GUIDANCE TO SLOWLY MIGRATE NORTHWARD UP THE
FLORIDA EAST COAST THROUGH THE DAY AND THEN BEGIN TO BE ABSORBED
INTO THE MAIN EASTERN CONUS TROUGH AND EJECTED TO THE NORTHEAST
TONIGHT. SIMILAR TO SUNDAY...THE MOIST ATMOSPHERE WITH BOTH UPPER
LEVEL SUPPORT AND BROAD SURFACE FOCUS FOR ASCENT WILL COMPLICATE THE
FORECAST AND MAKE MUCH SPATIAL AND TEMPORAL RESOLUTION IN THE
FORECAST CONVECTIVE PATTERN UNREALISTIC. HOWEVER...WILL DO MY BEST
TO TRY AND GIVE SOME USEFUL DECISION SUPPORT INFORMATION. IN CLOSEST
PROXIMITY TO THE BEST SYNOPTIC SUPPORT...THE SREF/NAM/ECMWF ALL PIN
THE MOST NUMEROUS SHOWER ACTIVITY BY LATE MORNING OVER THE SOUTHERN
HALF OF THE REGION. THIS MAKES SENSE WITH THE IMPULSE ALOFT AND THE
MOST PRONOUNCED SURFACE CONVERGENCE IN THIS REGION. WILL LIKELY TAKE
A FEW HOURS OF HEATING TO REALLY GET THINGS GOING...BUT THEREAFTER
SHOULD BE LOOKING AT SCT TO NMRS SOUTH OF TAMPA BAY. RAIN CHANCES
WILL DECREASE WITH FURTHER NORTHWARD TRAVEL THIS MORNING.
LATER IN THE DAY...THE SURFACE LOW SHOULD REACH THE NORTHERN FLORIDA
PENINSULA. A WEAK WESTERLY FLOW IN THE WAKE OF THIS LOW CENTER WILL
ACT AS...OR HELP THE INLAND PENETRATION OF A WEAK SEA-BREEZE. WITH
THIS IN MIND...WOULD EXPECT THE BEST RAIN CHANCES TO SHIFT INLAND TO
THE I-75 CORRIDOR AND EASTWARD BY THE SECOND HALF OF THE
AFTERNOON/EVENING. FROM COASTAL TAMPA BAY AREA NORTHWARD DURING THE
LATE DAY PERIOD IT IS POSSIBLE THAT WE WILL SEE A PERIOD WITH VERY
LOW RAIN CHANCES SHOULD THIS FLOW DEVELOP IN TIME. FURTHER SOUTH
DOWN TOWARD CHARLOTTE HARBOR...SOME RESIDUAL SURFACE CONVERGENCE
WILL KEEP SCT SHOWERS IN THE FORECAST THROUGH THE DAY.
A MORE DEFINED 1000-700MB WESTERLY FLOW PATTERN SHOULD BECOME
ESTABLISHED BY THE SECOND HALF OF TONIGHT. THIS PATTERN IS ALREADY
CLIMO FAVORED FOR EARLY MORNING SHOWERS DEVELOPMENT OVER THE
EASTERN GULF OF MEXICO THAT MIGRATE TO THE COAST. TOMORROW
MORNING...THE GFS/ECMWF BOTH SHOW A MORE NW FLOW NORTH OF TAMPA BAY
AND A SW FLOW TO THE SOUTH. THIS CONVERGENT PATTERN (SHOULD IT
OCCUR) SHOULD ENHANCE THE COVERAGE OF SHOWERS APPROACHING THE
COAST...ESPECIALLY TO THE SOUTH OF TAMPA BAY. IN ADDITION...GLOBAL
GUIDANCE AGREE IN A FAVORABLE RRQ JET STRUCTURE FOR DIVERGENT FLOW
ALOFT OVER THE REGION. NOT ANTICIPATING A TUESDAY MORNING
WASHOUT...HOWEVER THOSE WITH RAIN SENSITIVE PLANS ALONG AND INSIDE
THE I-75 CORRIDOR SHOULD AT LEAST PLAN TO DODGE A FEW PASSING
SHOWERS BEGINNING FAIRLY EARLY IN THE DAY.
BY AFTERNOON...DEVELOPING SEA-BREEZE CIRCULATIONS WILL DECREASE OR
LIKELY REVERSE THE CONVERGENT PATTERN OVER THE NEAR SHORE WATERS AND
THE SECOND HALF OF THE DAY SHOULD TRANSITION TO ONE TYPICAL FOR A
WESTERLY FLOW PATTERN. THIS MEANS BEST RAIN CHANCES INLAND FROM THE
I-75 CORRIDOR OVER TOWARD THE FL EAST COAST...AND LOW RAIN CHANCES
FOR THE BEACHES OF THE FLORIDA WEST COAST.
THIS MESSY PATTERN WILL THEN BE GONE FOR THE MIDDLE OF THE WEEK AS A
TYPICAL SUMMER/AUGUST PATTERN ALOFT AND AT THE SURFACE AGAIN BECOMES
ESTABLISHED ACROSS THE REGION. HAPPY MONDAY EVERYONE!
&&
.LONG TERM (WEDNESDAY THROUGH NEXT SUNDAY)...
UPPER LEVEL TROUGHING OVER THE EASTERN CONUS SHARPENS UP AND DEEPENS
INTO A LOW OVER/OFF THE CANADIAN MARITIMES FOR THE WEEKEND. AS THIS
OCCURS THE TROUGHING OVER THE SOUTHEAST U.S. LIFTS NORTH AND
NORTHEAST...ALLOWING AN ATLANTIC UPPER RIDGE INITIALLY ACROSS SOUTH
FL AND CUBA TO MOVE NORTH AND BUILD INTO THE GULF. AT THE SURFACE
THE NATIONAL HURRICANE CENTER HAS BERTHA WELL OFF THE NEW ENGLAND
COAST AT THE START OF THE PERIOD WHILE HIGH PRESSURE CENTERED IN
THE OPEN ATLANTIC RIDGES INTO THE GULF OF MEXICO...WITH AN AXIS
BETWEEN THE KEYS AND CUBA. THE AXIS LIFTS INTO SOUTH FL THU THEN
CENTRAL FL FRI...WHERE IT MEANDERS INTO THE WEEKEND AS A RATHER
BROAD RIDGE WITH A RELAXED GRADIENT.
THE CURRENT FORECAST PHILOSOPHY IS FOR ISOLATED TO SCATTERED...
30 TO 40 POPS...SHOWERS AND THUNDERSTORMS. THE 1000-700 MB FLOW WILL
BE LIGHT AND PREVAILING WESTERLY ALTHOUGH IT BEGINS TO BACK TO
SOUTH TO SOUTHEAST ACROSS THE SOUTH TOWARD THE END OF THE PERIOD.
THIS WILL KEEP THE ATMOSPHERE MOIST WITH PWAT VALUES IN THE 1.8 TO 2
INCH PLUS RANGE. LOW LEVEL WESTERLY FLOW ENHANCED BY SEA BREEZES IN
THE AFTERNOON WILL RESULT IN SOME MORNING SHOWERS/STORMS THAT
INCREASE INLAND DURING THE AFTERNOONS. OVERNIGHT LOWS START OFF NEAR
NORMAL BUT WARM SLIGHTLY THROUGH THE WEEK WHILE AFTERNOON HIGHS ARE
A DEGREE OR 2 ABOVE NORMAL.
&&
.AVIATION...
VFR CONDITIONS PREVAIL ACROSS THE REGION EARLY THIS MORNING. OUTSIDE
OF DEVELOPING DIURNAL STORMS...THESE VFR CONDITIONS ARE EXPECTED TO
CONTINUE. WINDS WILL REMAIN LIGHT THROUGH THE DAY SHIFTING TO THE
WEST DURING THE AFTERNOON/EARLY EVENING FOR THE NEAR COASTAL
TERMINALS.
&&
.MARINE...
A WEAK AREA OF LOW PRESSURE WILL MOVE SLOWLY NORTHWARD OVER THE
FLORIDA PENINSULA TODAY AND THEN EXIT TO THE OUR NORTHEAST TONIGHT
AND TUESDAY. VARIABLE WIND FLOW TODAY IN CLOSE PROXIMITY TO THIS LOW
CENTER WILL BECOME A MORE PREDOMINANT WEST FLOW ACROSS THE EASTERN
GULF OF MEXICO FOR THE MIDDLE OF THE WEEK. HIGH PRESSURE BECOMES
FIRMLY ESTABLISHED OVER THE REGION FOR THE SECOND HALF OF THE WEEK
RESULTING IN LIGHT FLOW HIGHLIGHTED BY DEVELOPING ONSHORE FLOW EACH
AFTERNOON NEAR THE COAST.
&&
.FIRE WEATHER...
A MOIST LOW LEVEL ENVIRONMENT WILL KEEP RELATIVE HUMIDITY LEVELS WELL
ABOVE CRITICAL LEVELS THROUGH THE MIDDLE OF THE WEEK. RAIN CHANCES
WILL REMAIN HIGH THROUGH TUESDAY...ESPECIALLY OVER SOUTHERN AND
INLAND PORTIONS OF THE FORECAST AREA. SHOWERS AND STORM COVERAGE
SHOULD RETURN TO MORE NORMAL LEVELS FOR EARLY AUGUST BY THE MIDDLE
PORTION OF THE WEEK.
FOG POTENTIAL...SOME SHALLOW GROUND FOG MAY FORM OVER INLAND
LOCATIONS DURING THE EARLY MORNING HOURS THE NEXT FEW DAYS
BUT NO SIGNIFICANT VISIBILITY RESTRICTIONS ARE EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 90 80 92 78 / 40 20 50 30
FMY 91 77 92 76 / 50 30 60 20
GIF 91 76 92 75 / 60 30 50 20
SRQ 91 79 90 77 / 40 30 50 30
BKV 92 74 92 72 / 40 20 50 30
SPG 91 81 91 79 / 40 30 50 30
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/AVIATION/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...RUDE
AREA FORECAST DISCUSSION
NWS MIAMI FL
154 AM EDT MON AUG 4 2014
.AVIATION...
LIGHT RAIN CONTINUES ACROSS MUCH OF THE REGION...WITH STORMS OVER
THE LOCAL WATERS. AN AREA OF LOW PRESSURE OVER THE REGION WILL
DRIFT NORTH THROUGH THE DAY...WHICH WILL IMPART A WEST SOUTHWEST
FLOW ACROSS THE REGION. THE NOCTURNAL CONVECTION WILL DISRUPT THE
DIURNAL CYCLE...AND STORMS MAY NOT REDEVELOP UNTIL LATE IN THE
DAY...IF AT ALL. HOWEVER...GUIDANCE CONTINUES TO INDICATE THE
SHOWERS AND STORMS WILL REDEVELOP ACROSS THE EAST COAST...SO KEPT
VCSH/VCTS FOR NOW.
&&
.PREV DISCUSSION... /ISSUED 731 PM EDT SUN AUG 3 2014/
AVIATION...
CONVECTION GOT A LATE START THIS AFTERNOON DUE TO RAIN-COOLED
AIRMASS ALONG EAST COAST DELAYING ACTIVITY SO PERSISTING UNTIL
AROUND 02Z THIS EVENING AND WILL LIKELY REDEVELOP AFT 14Z MONDAY.
SURFACE WIND WILL BECOME LIGHT SW EARLY THIS EVENING WITH THE
TROUGH MOVING NORTH OF THE REGION BY LATE MONDAY. THIS WILL
PREVENT AN EAST COAST SEA BREEZE WITH NUMEROUS TSRA EXPECTED WELL
INTO THE AFTERNOON.
KOB
PREV DISCUSSION... /ISSUED 252 PM EDT SUN AUG 3 2014/
NEAR TERM...(THIS AFTERNOON)
THE HEAVY LINE OF SHOWERS/TSTMS THAT MOVED ASHORE EARLY THIS
AFTERNOON HAS WEAKENED AND DISSIPATED...MAINLY DUE TO THE MORE
STABLE EAST COAST WHERE TEMPERATURES HAVE REMAINED STEADY IN THE
LOWER 80S FROM THE EXTENSIVE CLOUD COVERAGE ASSOCIATED WITH THE
OFFSHORE CONVECTION EARLIER. FARTHER INLAND...ADDITIONAL SHOWERS
HAVE BEGUN TO DEVELOP WHERE A BETTER SOURCE OF INSTABILITY EXISTS
(TEMPERATURES HAVE ALREADY REACHED THE UPPER 80S TO 90 DEG RANGE).
THE LATEST HRRR HAS PICKED UP ON THESE TRENDS AND HAS BACKED OFF
ON THE EARLIER SUGGESTED EAST COAST ACTIVITY LATER THIS
AFTERNOON/EARLY EVENING SHOWING MOSTLY STRATIFIED PRECIP FOR THE
SE FL COAST (OR LIGHT RAIN WITH EMBEDDED HEAVIER SHOWERS/TSTMS
ALONG THE EAST COAST) THROUGH THE AFTERNOON HOURS. HOWEVER...THE
LAKE REGION INCLUDING PALM BEACH COUNTY COULD OBSERVE SOME
HEAVIER AFTERNOON SHOWERS/TSTMS.
SHORT TERM...(TONIGHT-TUESDAY NIGHT)
THE LATEST SHORT-RANGE MODEL GUIDANCE REMAINS CONSISTENT FROM CYCLE
TO CYCLE AND INDICATES THE WET PATTERN PERSISTING INTO THE UPCOMING
WEEK AS A SURFACE TROUGH OF LOW PRESSURE AND UPPER TROUGH CONTINUE
TO INFLUENCE THE LOCAL WEATHER PATTERN. AN ASCAT PASS THIS
AFTERNOON SHOWED TS BERTHA CENTERED NEAR THE SOUTHEASTERN BAHAMA
ISLANDS. THE LATEST ADVISORY INDICATES BERTHA TURNING NORTHWARD
AND REMAINING JUST EAST OF THE BAHAMAS THROUGH MONDAY AS IT PASSES
(SHOULD NOT HAVE ANY DIRECT IMPACT ON THE LOCAL AREA). THE LATEST
GUIDANCE INDICATES THE SFC TROUGH OVERHEAD THAT IS IMPACTING THE
LOCAL WEATHER SLOWLY LIFTING NWD INTO MONDAY...WHICH WILL
TRANSLATE TO SW LOW-LEVEL FLOW WITH THE RIDGE AXIS ORIENTED E-W
SOUTH OF THE AREA OVER THE STRAITS. THIS LOW-LEVEL FLOW COMBINED
WITH THE AFOREMENTIONED DEEP LAYER MOISTURE (MODEL PWAT VALUES
RANGING FROM 2- 2.3" MONDAY-TUESDAY EVENING) COULD TRANSLATE TO A
POTENTIAL HEAVY RAINFALL/FLOODING CONCERN OVER PORTIONS OF THE
LOCAL AREA PERIODICALLY...ESPECIALLY WITH THE RECENT ACTIVITY AND
THE ALREADY SATURATED GROUNDS. THE LATEST RAINFALL ACCUMULATION
PROJECTION INDICATES 1.5 TO 2.5" WIDESPREAD AMOUNTS. MUCH HIGHER
LOCALIZED AMOUNTS WHERE ANY ACTIVITY BECOMES FOCUSED FOR A PERIOD
OF TIME WILL REMAIN POSSIBLE EACH DAY. THE SURFACE FLOW IS
PROJECTED TO REMAIN LIGHT ENOUGH FOR AN EAST COAST SEA BREEZE TO
DEVELOP EACH DAY...WHICH TYPICALLY RESULTS IN THE AFTERNOON
CONVECTION SETTING UP AND FAVORING THE EAST COAST.
HOWEVER...SIMILAR TO TODAY...STABILITY COULD PLAY A ROLE HERE AND
END UP REDUCING THE OVERALL HEAVY RAIN/FLOODING CONCERNS...IF THE
OVERCAST AND RELATIVELY COOL CONDITIONS ARE REALIZED THROUGH THE
AFTERNOON PERIODS AGAIN MONDAY AND TUESDAY.
LONG TERM (WEDNESDAY-WEEKEND)...
THE LATEST EXTENDED GUIDANCE CONTINUES TO SUGGEST A RETURN OF A MORE
TYPICAL SUMMER-LIKE PATTERN ACROSS THE REGION THROUGH THE SECOND
HALF OF THE WEEK AND INTO THE WEEKEND AS A DEEP LAYER RIDGE BUILDS
BACK OVERHEAD. AT THIS TIME...IT APPEARS WEDNESDAY COULD BE THE
TRANSITION DAY...WHICH WOULD MEAN ANOTHER WET AFTERNOON WITH A
SUFFICIENT AMOUNT OF DEEP LAYER MOISTURE AND LIGHT SW LOW-LEVEL FLOW
TO FOCUS THE AFTERNOON ACTIVITY TOWARD THE EAST COAST.
AVIATION...
MOST OF THE CONVECTION HAS DISSIPATED ACROSS THE NEAR
SHORE ATLANTIC WATERS THIS AFTERNOON AFTER ENCOUNTERING A MORE
STABLE AIR MASS. ONLY AREAS OF LIGHT TO MODERATE SHOWERS REMAIN
WHICH SHOULD BE COVERED WELL WITH VCSH. LATEST HRRR KEEPS SHOWERS
ACROSS THE EAST COAST THROUGH THE EARLY EVENING WITH CONTINUED
SOUTHEAST TO SOUTHERLY WINDS. ANY REMAINING CONVECTION SHOULD STAY
ACROSS THE INTERIOR POSSIBLY AFFECTING KAPF. LEFT VCTS MENTION
THERE UNTIL 01Z.
MARINE...
TROPICAL STORM BERTHA IS FORECAST TO REMAIN WELL EAST OF THE SOUTH
FLORIDA MARINE AREAS AS IT TURNS NORTH EAST OF THE BAHAMAS LATE
TONIGHT THROUGH MONDAY. WINDS ARE FORECAST TO REMAIN LIGHT AND SHIFT
TO THE SOUTHWEST THROUGH THE EARLY PORTION OF THE WEEK. SCATTERED
SHOWERS AND STORMS COULD LEAD TO GUSTY WINDS AND LOCALLY CHOPPIER
CONDITIONS EACH DAY ALONG WITH REDUCED VISIBILITIES.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 90 77 92 77 / 70 40 60 30
FORT LAUDERDALE 90 80 92 80 / 70 40 50 20
MIAMI 90 79 91 79 / 70 40 50 20
NAPLES 90 76 91 77 / 50 60 50 20
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...21/KM
LONG TERM....21/KM
AVIATION...84/AK
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
746 AM EDT MON AUG 4 2014
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE UP THE SOUTHEAST COAST ALONG A
STALLED FRONT THROUGH TUESDAY. A COLD FRONT WILL APPROACH FROM NORTH
LATE THIS WEEK AND STALL OVER OR NEAR THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AROUND DAWN..A WEAK AREA OF LOW PRES WAS OFF THE NE FLORIDA COAST
WITH A STALLED COASTAL TROUGH EXTENDING NE THROUGH OUR COASTAL
WATERS. DEEP MOISTURE AXIS ON LATEST RAP ANALYSIS HAS BEEN NUDGING
BACK TOWARD THE COAST OVERNIGHT WITH DEEPEST MOISTURE OFFSHORE.
WIDESPREAD STRATUS ACROSS THE REGION AWAY FROM THE IMMEDIATE COAST
WITH SOME 1-3 MILE VSBYS IN SPOTS.
FORECAST DETAILS ON THE SKETCHY SIDE TODAY ALONG AND E OF THE I-95
CORRIDOR WITH HIGHEST RAIN CHANCES COASTAL AREAS...ESPECIALLY ALONG
THE SE GEORGIA COAST THIS MORNING AND NORTH OF BEAUFORT AFTER MID
MORNING...PERHAPS INTO THE AFTERNOON HOURS. THE NAM AND MANY OF
ITS VARIANTS SUGGEST THE SURFACE WAVE WILL CLOSE OFF AND DRIFT
FURTHER NORTHWARD TODAY THAN EITHER THE GFS/ECMWF PORTRAY. THE MAIN
IMPLICATION OF THIS WOULD BE A POTENTIAL FOR MORE SIGNIFICANT AND
WIDESPREAD CONVECTIVE RAINS ACROSS THE CENTRAL SOUTH CAROLINA
COAST. GIVEN THE UNCERTAINTIES AND MOST RECENT RUNS OF NSSL WRF
AND RUC RAPID REFRESH MODELS WE WERE HESITANT ON PAINTING TOO MUCH
QPF WITH THE MAIN SYNOPTIC BOUNDARY REMAINING OFFSHORE. EVEN
SO...PWATS UP TO 2.25 INCHES SUGGEST CONVECTIVE RAINS COULD BE
LOCALLY HEAVY WITH TORRENTIAL DOWNPOURS POSSIBLE EAST OF I-95. WILL
HAVE TO WAIT AND SEE IF ANY SIGNIFICANT RAINS COINCIDE WITH A MID
AFTERNOON HIGH TIDE IN DOWNTOWN CHARLESTON...CONFIDENCE VERY LOW
ON ANY MESOSCALE DETAIL AT THIS POINT.
FAR INLAND AREAS WILL PROBABLY HAVE TO WAIT UNTIL THIS AFTERNOON
FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP AND SOME MODELS
ARE QUITE SLIM WITH COVERAGE. WARMEST TEMPS SOUTH AND INLAND
TODAY... PERHAPS A FEW LOWER 90S. CLOSER TO UPPER 80S ACROSS SOUTH
CAROLINA AND MID 80S IN PLACES SUCH AS NE CHARLESTON COUNTY.
DECREASING RAIN CHANCES TONIGHT AS A SHORT WAVE ACROSS THE TENNESSEE
VALLEY BEGINS TO NUDGE THE DEEP MOIST AXIS...LOW PRES WAVE...AND
TS BERTHA FURTHER OFFSHORE AWAY FROM THE FORECAST AREA. MAINTAINED
A FEW LINGERING SHOWERS ALONG NORTHERN COASTAL AREAS...OTHERWISE
SOME INLAND CLEARING LIKELY. LATER SHIFTS MAY NEED TO ADD SOME
PATCHY FOG PER SOME OF THE 00Z GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...MODELS CONTINUE TO INDICATE THAT A WEAK LOW PRESSURE
SYSTEM WILL SLOWLY SHIFT NORTHEAST AND AWAY FROM THE AREA THROUGHOUT
THE DAY...THUS SUGGESTING A DECREASING TREND IN SHOWER AND/OR
THUNDERSTORM COVERAGE OVER THE SOUTHEAST. EXPECT LIGHT NORTHERLY
FLOW TO BACK TO THE WEST BEHIND THE DEPARTING LOW...RESULTING IN
LESS CLOUD COVER INLAND AND WARMING TEMPS AS SFC HEATING OCCURS.
LATEST 1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE
UPPER 80S TO LOWER 90S...WARMEST INLAND. OVERNIGHT TEMPS SHOULD
RANGE BETWEEN THE LOW TO MID 70S AWAY FROM THE COAST.
WEDNESDAY AND THURSDAY...THE PATTERN APPEARS DRYER AS HIGH PRESSURE
EXTENDS OVER THE WESTERN ATLANTIC WHILE A PIEDMONT TROUGH BECOMES
ESTABLISHED INLAND. HOWEVER...A FEW SHOWERS AND/OR THUNDERSTORM CAN
NOT BE RULED OUT EACH AFTERNOON WITH ENHANCED CONVERGENCE ALONG THE
TROUGH INLAND OR SEABREEZE NEAR THE COAST. TEMPS WILL BE WARMER THAN
PREVIOUS DAYS AS A WEST/NORTHWEST DOWNSLOPE FLOW OCCURS ALOFT DURING
PEAK SFC HEATING EACH AFTERNOON UNDER PARTLY CLOUDY SKIES. LATEST
1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE LOW TO
MID 90S...WARMEST INLAND. OVERNIGHT LOWS SHOULD RANGE IN THE LOW TO
MID 70S AWAY FROM THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH EARLY THIS
WEEKEND...WITH INCREASING MOISTURE LEVELS CHARACTERIZED BY PWATS
AROUND 2.0 INCHES. CHANCES OF SHOWERS AND/OR THUNDERSTORMS SHOULD
RESULT ON FRIDAY...WITH SLIGHTLY INCREASING COVERAGE INTO THE WEEKEND
AS THE FRONT STALLS OVER OR NEAR THE AREA. DEEP MOISTURE AND
CONVECTIVE ACTIVITY ASSOCIATED WITH THE FRONT WILL LIKELY LEAD TO
MORE CLOUD COVER AND SLIGHTLY COOLER TEMPS OVER THE AREA THIS
WEEKEND INTO EARLY NEXT WEEK. IN GENERAL...OVERALL HIGH TEMPS SHOULD
RANGE IN THE LOWER 90S ON FRIDAY...BEFORE COOLING INTO THE UPPER 80S
TO AROUND 90 LATER THIS WEEKEND INTO EARLY NEXT WEEK. OVERNIGHT LOWS
SHOULD RANGE IN THE LOW TO MID 70S...COOLEST INLAND EARLY NEXT WEEK.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
KCHS...CIGS AT OR BELOW 400 FT AT 1130Z...PROBABLY A BIT SLOW TO
DISSIPATE OR LIFT GIVEN THE MOIST LAYER DEEPENING ACROSS THE AREA.
WE HAVE IFR CIGS PUNCTUATED BY SHOWER THREAT AFTER MID MORNING
AND CIGS SHOULD LIFT TO MVFR BY THIS AFTERNOON PER LATEST FORECAST
SOUNDINGS. CONFIDENCE ON SHOWER OR TSTM TIMING POOR TODAY GIVEN
SHIFTS IN LOW LEVEL MOISTURE CONVERGENCE FIELDS AND TRACK OF THE
LOW PRES TO THE SOUTH. MVFR OR LOWER CONDITIONS ARE POSSIBLE AGAIN
TONIGHT.
KSAV...LIFR CONDITIONS EARLY THIS MORNING WITH BUILD-DOWN STRATUS
IN PLACE AT THE TERMINAL. FORECAST SOUNDINGS SUGGEST LOW CIGS WILL
TEND TO DISSIPATE BY LATE MORNING WITH MVFR CIGS POSSIBLE THIS
AFTERNOON...ESPECIALLY IF SCATTERED CONVECTIVE RAINS DEVELOP. TONIGHT
THERE IS A CHANCE FOR MVFR/IFR CIGS ONCE AGAIN WITH PERHAPS SOME
LIGHT FOG.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS EARLY
TUESDAY AS LOW PRESSURE SHIFTS NORTHEAST OFF THE COAST. PREVAILING
VFR CONDITIONS SHOULD THEN OCCUR TUESDAY AFTERNOON THROUGH LATE
WEEK...BUT TEMPO FLIGHT RESTRICTIONS WILL REMAIN POSSIBLE EACH
AFTERNOON DUE TO SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
A WAVE OF LOW PRESSURE OFF THE FLORIDA COAST WILL LIFT NORTH ALONG
THE STALLED FRONT THROUGH TONIGHT. A TRICKY COASTAL WATERS FORECAST
TODAY WITH RESPECT TO GRADIENT ENHANCEMENTS AND TRACK OF THE
SURFACE WAVE. SEAS WERE ALREADY ELEVATED THIS MORNING AND
CONTINUED A SMALL CRAFT ADVISORY FOR OFFSHORE GEORGIA WATERS
THROUGH MID AFTERNOON AND IT MAY NEED A EXTENSION A LITTLE FURTHER
LATER TODAY. NEAR SHORE...MODELS DO NOT SHOW ANY SUBSTANTIAL
DEEPENING OF THE SURFACE WAVE AND EXPECT WINDS AVERAGING 15 KT
WITH THE PATTERN ONE OF CONVERGENCE INSTEAD OF JETTING. SEAS 3 TO
5 FT NEAR SHORE AND 4 TO 6 FT BEYOND 20 NM WITH MORE OF A GROUND
SWELL FROM BERTHA THAN LARGER LONG PERIOD SWELL. WINDS WILL BEGIN
TO BACK OFFSHORE OVER GEORGIA WATERS TONIGHT IN THE WAKE OF THE
LOW PASSING BY OFFSHORE.
TUESDAY THROUGH SATURDAY...SHOWERS AND THUNDERSTORMS COULD AFFECT
COASTAL WATERS INTO TUESDAY AS SFC LOW PRESSURE SHIFTS NORTHEAST AND
AWAY FROM THE AREA. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS THIS OCCURS...WITH NORTH/NORTHEAST WINDS
EVENTUALLY BECOMING OFFSHORE AS THE SFC LOW PULLS AWAY FROM THE
AREA. HOWEVER...SWELLS ASSOCIATED WITH TROPICAL CYCLONE BERTHA WILL
AFFECT THE WATERS...WITH SEAS POSSIBLY BUILDING TO 5-6 FT OVER OUTER
GEORGIA WATERS ON TUESDAY. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS MID TO LATE WEEK WHILE A TROUGH OF LOW PRESSURE DEVELOPS
INLAND. THIS SHOULD RESULT IN SOUTH/SOUTHEAST WINDS AT OR BELOW
15 KT OVER THE WATERS...HIGHEST WITH AFTERNOON SEABREEZE
CIRCULATIONS THAT DEVELOP NEAR THE COAST. SEAS SHOULD RANGE BETWEEN
1-3 FT. SHOWER AND/OR THUNDERSTORM COVERAGE WILL LIKELY INCREASE LATER
THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTH AND STALLS
OVER OR NEAR THE AREA.
RIP CURRENTS...BORDERLINE RISK FOR MODERATE TODAY WITH ONGOING
SEAS A BIT HIGHER THAN ANTICIPATED. GROUND SWELL FROM TS BERTHA
ENOUGH TO FORECAST A MODERATE RISK TODAY TO BE ON THE SAFE SIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ374.
&&
$$
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
434 AM EDT MON AUG 4 2014
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL MOVE UP THE SOUTHEAST COAST ALONG A
STALLED FRONT THROUGH TUESDAY. A COLD FRONT WILL APPROACH FROM NORTH
LATE THIS WEEK AND STALL OVER OR NEAR THE AREA THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
PRE-DAWN..A WEAK AREA OF LOW PRES WAS OFF THE NE FLORIDA COAST WITH
A STALLED COASTAL TROUGH EXTENDING NE THROUGH OUR COASTAL WATERS.
DEEP MOISTURE AXIS ON LATEST RAP ANALYSIS HAS BEEN NUDGING BACK TOWARD
THE COAST OVERNIGHT WITH DEEPEST MOISTURE OFFSHORE. ALONG AND WEST
OF I-95 SKIES HAD BEEN CLEAR TO PARTLY CLOUDY BUT EXPECT MORE IN
THE WAY OF LOW CLOUDS AND PATCHY FOG TO INCREASE TOWARD DAYBREAK.
STRONG LOW LEVEL SPEED/MOISTURE CONVERGENCE BEGINNING TO SHOW WITH
INCREASING SHOWERS AND TSTMS OVER THE WATERS. CONVECTIVE RAINS WILL
LIKELY BEGIN TO IMPACT SOME COASTAL AREAS OF SE GEORGIA AND SOUTH
CAROLINA BY DAYBREAK WITH BEST TRAJECTORIES INTO THE CHARLESTON
COUNTY COAST.
FORECAST DETAILS ON THE SKETCHY SIDE TODAY ALONG AND E OF THE I-95
CORRIDOR WITH HIGHEST RAIN CHANCES COASTAL AREAS...ESPECIALLY ALONG
THE SE GEORGIA COAST THIS MORNING AND NORTH OF BEAUFORT AFTER MID
MORNING...PERHAPS INTO THE AFTERNOON HOURS. THE NAM AND MANY OF
ITS VARIANTS SUGGEST THE SURFACE WAVE WILL CLOSE OFF AND DRIFT
FURTHER NORTHWARD TODAY THAN EITHER THE GFS/ECMWF PORTRAY. THE MAIN
IMPLICATION OF THIS WOULD BE A POTENTIAL FOR MORE SIGNIFICANT AND
WIDESPREAD CONVECTIVE RAINS ACROSS THE CENTRAL SOUTH CAROLINA
COAST. GIVEN THE UNCERTAINTIES AND MOST RECENT RUNS OF NSSL WRF
AND RUC RAPID REFRESH MODELS WE WERE HESITANT ON PAINTING TOO MUCH
QPF WITH THE MAIN SYNOPTIC BOUNDARY REMAINING OFFSHORE. EVEN
SO...PWATS UP TO 2.25 INCHES SUGGEST CONVECTIVE RAINS COULD BE
LOCALLY HEAVY WITH TORRENTIAL DOWNPOURS POSSIBLE EAST OF I-95. WILL
HAVE TO WAIT AND SEE IF ANY SIGNIFICANT RAINS COINCIDE WITH A MID
AFTERNOON HIGH TIDE IN DOWNTOWN CHARLESTON...CONFIDENCE VERY LOW
ON ANY MESOSCALE DETAIL AT THIS POINT.
FAR INLAND AREAS WILL PROBABLY HAVE TO WAIT UNTIL THIS AFTERNOON
FOR ISOLATED TO SCATTERED CONVECTION TO DEVELOP AND SOME MODELS
ARE QUITE SLIM WITH COVERAGE. WARMEST TEMPS SOUTH AND INLAND
TODAY... PERHAPS A FEW LOWER 90S. CLOSER TO UPPER 80S ACROSS SOUTH
CAROLINA AND MID 80S IN PLACES SUCH AS NE CHARLESTON COUNTY.
DECREASING RAIN CHANCES TONIGHT AS A SHORT WAVE ACROSS THE TENNESSEE
VALLEY BEGINS TO NUDGE THE DEEP MOIST AXIS...LOW PRES WAVE...AND
TS BERTHA FURTHER OFFSHORE AWAY FROM THE FORECAST AREA. MAINTAINED
A FEW LINGERING SHOWERS ALONG NORTHERN COASTAL AREAS...OTHERWISE
SOME INLAND CLEARING LIKELY. LATER SHIFTS MAY NEED TO ADD SOME
PATCHY FOG PER SOME OF THE 00Z GUIDANCE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
TUESDAY...MODELS CONTINUE TO INDICATE THAT A WEAK LOW PRESSURE
SYSTEM WILL SLOWLY SHIFT NORTHEAST AND AWAY FROM THE AREA THROUGHOUT
THE DAY...THUS SUGGESTING A DECREASING TREND IN SHOWER AND/OR
THUNDERSTORM COVERAGE OVER THE SOUTHEAST. EXPECT LIGHT NORTHERLY
FLOW TO BACK TO THE WEST BEHIND THE DEPARTING LOW...RESULTING IN
LESS CLOUD COVER INLAND AND WARMING TEMPS AS SFC HEATING OCCURS.
LATEST 1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE
UPPER 80S TO LOWER 90S...WARMEST INLAND. OVERNIGHT TEMPS SHOULD
RANGE BETWEEN THE LOW TO MID 70S AWAY FROM THE COAST.
WEDNESDAY AND THURSDAY...THE PATTERN APPEARS DRYER AS HIGH PRESSURE
EXTENDS OVER THE WESTERN ATLANTIC WHILE A PIEDMONT TROUGH BECOMES
ESTABLISHED INLAND. HOWEVER...A FEW SHOWERS AND/OR THUNDERSTORM CAN
NOT BE RULED OUT EACH AFTERNOON WITH ENHANCED CONVERGENCE ALONG THE
TROUGH INLAND OR SEABREEZE NEAR THE COAST. TEMPS WILL BE WARMER THAN
PREVIOUS DAYS AS A WEST/NORTHWEST DOWNSLOPE FLOW OCCURS ALOFT DURING
PEAK SFC HEATING EACH AFTERNOON UNDER PARTLY CLOUDY SKIES. LATEST
1000-850 THICKNESS VALUES SUPPORT OVERALL HIGH TEMPS IN THE LOW TO
MID 90S...WARMEST INLAND. OVERNIGHT LOWS SHOULD RANGE IN THE LOW TO
MID 70S AWAY FROM THE COAST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTH EARLY THIS
WEEKEND...WITH INCREASING MOISTURE LEVELS CHARACTERIZED BY PWATS
AROUND 2.0 INCHES. CHANCES OF SHOWERS AND/OR THUNDERSTORMS SHOULD
RESULT ON FRIDAY...WITH SLIGHTLY INCREASING COVERAGE INTO THE WEEKEND
AS THE FRONT STALLS OVER OR NEAR THE AREA. DEEP MOISTURE AND
CONVECTIVE ACTIVITY ASSOCIATED WITH THE FRONT WILL LIKELY LEAD TO
MORE CLOUD COVER AND SLIGHTLY COOLER TEMPS OVER THE AREA THIS
WEEKEND INTO EARLY NEXT WEEK. IN GENERAL...OVERALL HIGH TEMPS SHOULD
RANGE IN THE LOWER 90S ON FRIDAY...BEFORE COOLING INTO THE UPPER 80S
TO AROUND 90 LATER THIS WEEKEND INTO EARLY NEXT WEEK. OVERNIGHT LOWS
SHOULD RANGE IN THE LOW TO MID 70S...COOLEST INLAND EARLY NEXT WEEK.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
KCHS...VFR INITIALIZED THIS MORNING BUT MOISTURE CONVERGENCE WAS
INCREASING AT GOOD CLIP FROM THE ATLC. MVFR CIGS POSSIBLY LATER
NIGHT WITH A FEW SHOWERS BRUSHING BY. NEARING 12Z THERE SHOULD
BE INCREASED COVERAGE IN SHOWERS AND MORE IN THE LOW OF MVFR
CIGS WITH PATCHY IFR CIGS POSSIBLE. MODELS GENERALLY AGREE WITH WET
WEATHER TODAY AS LOW PRES DEVELOPS TO THE S AND RIDES ALONG THE
COASTAL FRONT. TWO CAMPS OF MODELS CURRENTLY WITH ONE CAMP SHOWING
SCATTERED CONVECTIVE RAINS TODAY AND THE OTHER WIDESPREAD SHOWERS
AND DEFINITE TSTMS WITH HEAVY RAINS. THE NAM MODEL INDICATES IFR
CIGS WITH VERY DEEP MOISTURE AND THIS SOLUTION CANNOT BE RULED OUT
BUT IT TOO PESSIMISTIC AT THIS TIME. CONVECTIVE RAINS SHOULD BE
ON THE DECREASE THIS EVENING WITH CHANCES OF MVFR CIGS LINGERING.
KSAV...WE START THE 06Z TAFS WITH VFR WEATHER...BUT SOME
NOCTURNAL SHRA/TSRA WILL FORM NEARBY OVERNIGHT IN RESPONSE TO THE
NEARBY QUASI-STATIONARY FRONT AND APPROACHING SURFACE LOW PRESSURE
WAVE. EVEN IF ANY WET WEATHER FAILS TO MATERIALIZE THERE IS STILL
GOOD CHANCES OF FLIGHT RESTRICTIONS DUE TO THE NOCTURNAL
INVERSION...THEN A CONTINUING CAP INTO MONDAY AFTERNOON. VFR
WEATHER LOOKS TO RETURN AGAIN LATE IN THE TAF CYCLE.
EXTENDED AVIATION OUTLOOK...LOW CHANCES OF MVFR CIGS/VSBYS EARLY
TUESDAY AS LOW PRESSURE SHIFTS NORTHEAST OFF THE COAST. PREVAILING
VFR CONDITIONS SHOULD THEN OCCUR TUESDAY AFTERNOON THROUGH LATE
WEEK...BUT TEMPO FLIGHT RESTRICTIONS WILL REMAIN POSSIBLE EACH
AFTERNOON DUE TO SHOWERS AND/OR THUNDERSTORMS.
&&
.MARINE...
A WAVE OF LOW PRESSURE OFF THE FLORIDA COAST WILL LIFT NORTH
ALONG THE STALLED FRONT THROUGH TONIGHT. A TRICKY COASTAL WATERS
FORECAST TODAY WITH RESPECT TO GRADIENT ENHANCEMENTS AND TRACK
OF THE SURFACE WAVE. SEAS WERE ALREADY ELEVATED THIS MORNING
AND CONTINUED A SMALL CRAFT ADVISORY FOR OFFSHORE GEORGIA WATERS
THROUGH MID AFTERNOON AND IT MAY NEED A EXTENSION A LITTLE FURTHER
LATER TODAY. NEAR SHORE...MODELS DO NOT SHOW ANY SUBSTANTIAL
DEEPENING OF THE SURFACE WAVE AND EXPECT WINDS AVERAGING 15 KT
WITH THE PATTERN ONE OF CONVERGENCE INSTEAD OF JETTING. SEAS
3 TO 5 FT NEAR SHORE AND 4 TO 6 FT BEYOND 20 NM WITH MORE OF
A GROUND SWELL FROM BERTHA THAN LARGER LONG PERIOD SWELL. WINDS
WILL BEGIN TO BACK OFFSHORE OVER GEORGIA WATERS TONIGHT IN
THE WAKE OF THE LOW PASSING BY OFFSHORE.
TUESDAY THROUGH SATURDAY...SHOWERS AND THUNDERSTORMS COULD AFFECT
COASTAL WATERS INTO TUESDAY AS SFC LOW PRESSURE SHIFTS NORTHEAST AND
AWAY FROM THE AREA. CONDITIONS SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS AS THIS OCCURS...WITH NORTH/NORTHEAST WINDS
EVENTUALLY BECOMING OFFSHORE AS THE SFC LOW PULLS AWAY FROM THE
AREA. HOWEVER...SWELLS ASSOCIATED WITH TROPICAL CYCLONE BERTHA WILL
AFFECT THE WATERS...WITH SEAS POSSIBLY BUILDING TO 5-6 FT OVER OUTER
GEORGIA WATERS ON TUESDAY. HIGH PRESSURE WILL THEN BUILD OVER THE
WATERS MID TO LATE WEEK WHILE A TROUGH OF LOW PRESSURE DEVELOPS
INLAND. THIS SHOULD RESULT IN SOUTH/SOUTHEAST WINDS AT OR BELOW
15 KT OVER THE WATERS...HIGHEST WITH AFTERNOON SEABREEZE
CIRCULATIONS THAT DEVELOP NEAR THE COAST. SEAS SHOULD RANGE BETWEEN
1-3 FT. SHOWER AND/OR THUNDERSTORM COVERAGE WILL LIKELY INCREASE LATER
THIS WEEKEND AS A COLD FRONT APPROACHES FROM THE NORTH AND STALLS
OVER OR NEAR THE AREA.
RIP CURRENTS...BORDERLINE RISK FOR MODERATE TODAY WITH ONGOING
SEAS A BIT HIGHER THAN ANTICIPATED. GROUND SWELL FROM TS BERTHA
ENOUGH TO FORECAST A MODERATE RISK TODAY TO BE ON THE SAFE SIDE.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EDT THIS AFTERNOON FOR AMZ374.
&&
$$
NEAR TERM...
SHORT TERM...DPB
LONG TERM...DPB
AVIATION...
MARINE...DPB
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
115 PM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING AND DURATION OF TSRA/SHRA IMPACTING THE TERMINALS THIS AFTERNOON.
* SECOND PERIOD OF SHRA/TSRA OVERNIGHT.
* W-SW WINDS BECOMING NE-E THIS AFTERNOON WITH COMBINED COLD
FRONT/LAKE BREEZE
ED F
//DISCUSSION...UPDATED 18Z...
WEAK COLD FRONT/LAKE BREEZE BOUNDARY APPEARING ON ORD TERMINAL
DOPPLER RADAR OVER THE PAST HOUR... ITS PROGRESSION/PENETRATION
INLAND HAS BEEN THE GREATEST OVER LAKE COUNTY IL... WITH BOUNDARY
STILL ONLY A COUPLE OF MILES INLAND ACROSS COOK AND LAKE INDIANA
COUNTIES. SEEING A FEW ISOLATED CELLS GO UP ALONG THE BOUNDARY AND
EXPECT THIS TREND TO CONTINUE INTO THE AFTERNOON. WITH IT THE
OVERALL PRESSURE GRADIENT REMAINS WEAK AND HENCE EXPECT WINDS TO
GENERALLY REMAIN NEAR TO BELOW 10 KT WITH THE EXCEPTION OF A
HIGHER GUST POSSIBLE FROM A THUNDERSTORM.
DO EXPECT COVERAGE OF SHRA/TSRA TO INCREASE SOMEWHAT DURING THE
EARLY TO MID AFTERNOON WITH WEAK LOW LEVEL CONVERGENCE ALONG THE
BOUNDARY. AIR MASS OVERALL ONLY MODESTLY UNSTABLE HOWEVER AND
UPPER LEVEL SUPPORT SUGGESTS BETTER COVERAGE OF RAIN/STORMS WILL
COME WITH A SECOND ROUND OF SHOWERS AND THUNDERSTORMS LATER THIS
EVENING INTO THE OVERNIGHT. WILL CONTINUE TO MONITOR THESE TRENDS
AND ADJUST CHALLENGING FORECAST ACCORDINGLY.
ED F
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* LOW TO MEDIUM IN TIMING OF INDIVIDUAL SHRA/TSRA AT TERMINAL
LOCATIONS THROUGH THE AFTERNOON.
* MEDIUM IN WIND SHIFT/SPEED DETAILS WITH LAKE BREEZE
BOUNDARY/WEAK COLD FRONT THIS AFTERNOON.
* LOW TO MEDIUM IN TIMING AND COVERAGE OF SECOND ROUND OF
SHRA/TSRA LATER THIS EVENING AND OVERNIGHT.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
1239 PM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 1040 AM CDT Mon Aug 4 2014
Will update the forecast to remove the morning fog over eastern IL,
otherwise just a few minor adjustments to sky cover and dewpoints today.
Weak 1021 mb high pressure over the Ohio river valley and ridging west
into the Ozarks of southern MO/northern AR will keep much of
eastern and southeast IL dry today. A short wave over central IA
to track se into NW and west central IL during the afternoon while
a frontal boundary over southern WI and near the MN/IA border
drops slowly southward into northern IL this evening. This will
develop isolated to scattered showers and thunderstorms during the
afternoon over areas mainly from I-55 nw with best chances nw of
the IL river. SPC has a 5% risk of damaging wind gusts and large
hail nw of I-55 late this afternoon and evening until sunset.
Highs in the mid 80s this afternoon looks on track. Somewhat muggy
dewpoints in the mid to upper 60s this morning to drop into the
upper 50s and lower 60s in southeast IL by mid afternoon and into
the low to mid 60s over the IL river valley. South winds less than
10 mph to prevail through the day.
07
&&
.AVIATION...
ISSUED 1240 PM CDT Mon Aug 4 2014
Isolated to scattered showers and thunderstorms will be possible
over central IL late this afternoon into mid evening especially
northern TAF sites of PIA and BMI. This due to a short wave over
IA moving se across central and northern IL into this evening with
and moving into upper level trof over OH/TN river valleys by Tue
morning. In addition, a frontal boundary drapped over southern WI
into northern IA will drop southward into northern IL later this
afternoon and to near PIA and BMI by Tue morning. Heating of more
unstable airmass over central IL to develop some convection later
this afternoon and into mid evening with best chances from I-74
north. Isolated convection to develop again Tue afternoon over
central IL after 18Z/1 pm. Winds stay less than 10 kts next 24
hours again. SSW winds of 5-9 kts this afternoon to diminish light
SSE after sunset. Light fog or haze possible between 06Z-14Z and
carried vsbys of 6 miles.
07
&&
.PREV DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1124 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* WIND SHIFT FROM WEST TO EAST-NORTHEAST THIS AFTERNOON WITH
COMBINATION OF COLD FRONT/LAKE BREEZE.
* SCATTERED SLOW MOVING SHRA/TSRA DEVELOPING EARLY TO MID AFTERNOON
AND CONTINUING INTO THIS EVENING/TONIGHT.
ED F
//DISCUSSION...UPDATED 12Z...
WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...THOUGH WAS HARD TO DISCERN IN SURFACE OBS WITH GENERALLY
WEAK PRESSURE GRADIENT AND LIGHT/VARIABLE WIND FIELD. VARIOUS
MODELS VARY SIGNIFICANTLY IN FINE SCALE DETAILS OF WIND FIELD
BEYOND THIS MORNING...BUT GENERAL EXPECTATION IS THAT FRONT WILL
CONTINUE TO DRIFT SLOWLY SOUTH ALONG THE LAKE AND COMBINE WITH
AFTERNOON LAKE BREEZE TO BRING A SHIFT TO NORTHEAST WINDS BY
EARLY/MID AFTERNOON. GRADIENT CONTINUES TO REMAIN WEAK WITH SPEEDS
GENERALLY LESS THAN 10 KT EXPECTED...THOUGH COULD BE AROUND 10 KT
WITH INITIAL FRONT/LAKE BREEZE PASSAGE. EAST-NORTHEAST WINDS THEN
CONTINUE THROUGH REMAINDER OF TAF PERIOD.
AS FOR SHRA/TSRA...ISOLATED CELLS OVER PARTS OF WI AND SOUTHERN
LAKE MICHIGAN EARLY THIS AM IN REGION OF WEAK ELEVATED ASCENT.
COVERAGE EXPECTED TO INCREASE EARLY THIS AFTERNOON ALONG FRONTAL
ZONE AS CONVERGENCE IN LOW LEVEL WIND FIELD INITIATES CONVECTION
IN WEAKLY UNSTABLE AIR MASS. GREATEST COVERAGE ANTICIPATED ACROSS
SOUTHERN WI/EASTERN IA AND NORTHWEST IL WHERE SOME LOW LEVEL
MOISTURE POOLING WITH YIELD MORE UNSTABLE CONDITIONS...THOUGH
CONVECTION ALLOWING MODEL GUIDANCE ALL TREND TOWARD SOME INCREASED
POTENTIAL ALONG THE FRONT AND COMBINED LAKE BREEZE BOUNDARY
INTO CHICAGO AREA AS WELL. SHRA/TSRA POTENTIAL LOOKS TO BE HIGHEST
LATER IN THE AFTERNOON INTO THIS EVENING. SCATTERED SHRA MAY
CONTINUE OVERNIGHT AS WELL...WITH SEVERAL MINOR UPPER LEVEL
DISTURBANCES PASSING ACROSS THE FORECAST AREA.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-LOW IN TIMING OF SHRA/TSRA DEVELOPMENT EARLY TO MID AFTERNOON.
* MEDIUM IN DETAILS OF WIND SHIFT/SPEED WITH COMBINED FRONT/LAKE
BREEZE THIS AFTERNOON.
* MEDIUM-LOW IN SPECIFIC LOCATIONS OF TSRA THIS AFTERNOON.
ED F
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.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:
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WWW.TWITTER.COM/NWSCHICAGO
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Area Forecast Discussion
National Weather Service Lincoln IL
1043 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 1040 AM CDT Mon Aug 4 2014
Will update the forecast to remove the morning fog over eastern IL,
otherwise just a few minor adjustments to sky cover and dewpoints today.
Weak 1021 mb high pressure over the Ohio river valley and ridging west
into the Ozarks of southern MO/northern AR will keep much of
eastern and southeast IL dry today. A short wave over central IA
to track se into NW and west central IL during the afternoon while
a frontal boundary over southern WI and near the MN/IA border
drops slowly southward into northern IL this evening. This will
develop isolated to scattered showers and thunderstorms during the
afternoon over areas mainly from I-55 nw with best chances nw of
the IL river. SPC has a 5% risk of damaging wind gusts and large
hail nw of I-55 late this afternoon and evening until sunset.
Highs in the mid 80s this afternoon looks on track. Somewhat muggy
dewpoints in the mid to upper 60s this morning to drop into the
upper 50s and lower 60s in southeast IL by mid afternoon and into
the low to mid 60s over the IL river valley. South winds less than
10 mph to prevail through the day.
07
&&
.AVIATION...
ISSUED 605 AM CDT Mon Aug 4 2014
Other than the threat for MVFR or local IFR vsbys in ground fog
over the next 60 to 90 minutes early this morning, VFR conditions
are expected this period. The main forecast challenge for later
today will be with the potential for TSRA, especially at KPIA
and KBMI as a weak cold front slips south into the lower Great
Lakes. Satellite data and surface observations indicate a band
of mid level clouds were tracking slowly east into west central
Illinois this morning. Bases of these clouds ranged from 5000 to
7000 feet with the overall movement mainly northeast. Forecast
soundings not showing much in the way of cumulus development excpt
across the far northern areas after 18z, but even there, it appears
to be mainly scattered at around 5000 feet. Will continue to include
a VCTS at PIA after 19z as this location will be closest to the
better instability. Not very confident after 00z with respect to
any of the convection that develops across the northwest to continue
across our area so will continue to hold off mentioning at any one
TAF site this evening. Surface winds will once again be a non-factor
with a southerly wind expected today at less than 10 kts, dropping
off to 5 kts or less aftr 00z.
Smith
&&
.PREV DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
918 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* WIND SHIFT FROM WEST TO EAST-NORTHEAST THIS AFTERNOON WITH
COMBINATION OF COLD FRONT/LAKE BREEZE.
* SCATTERED SLOW MOVING SHRA/TSRA DEVELOPING LATE MORNING INTO
EARLY AFTERNOON AND CONTINUING INTO THIS EVENING/TONIGHT.
RATZER
//DISCUSSION...UPDATED 12Z...
WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...THOUGH WAS HARD TO DISCERN IN SURFACE OBS WITH GENERALLY
WEAK PRESSURE GRADIENT AND LIGHT/VARIABLE WIND FIELD. VARIOUS
MODELS VARY SIGNIFICANTLY IN FINE SCALE DETAILS OF WIND FIELD
BEYOND THIS MORNING...BUT GENERAL EXPECTATION IS THAT FRONT WILL
CONTINUE TO DRIFT SLOWLY SOUTH ALONG THE LAKE AND COMBINE WITH
AFTERNOON LAKE BREEZE TO BRING A SHIFT TO NORTHEAST WINDS BY
EARLY/MID AFTERNOON. GRADIENT CONTINUES TO REMAIN WEAK WITH SPEEDS
GENERALLY LESS THAN 10 KT EXPECTED...THOUGH COULD BE AROUND 10 KT
WITH INITIAL FRONT/LAKE BREEZE PASSAGE. EAST-NORTHEAST WINDS THEN
CONTINUE THROUGH REMAINDER OF TAF PERIOD.
AS FOR SHRA/TSRA...ISOLATED CELLS OVER PARTS OF WI AND SOUTHERN
LAKE MICHIGAN EARLY THIS AM IN REGION OF WEAK ELEVATED ASCENT.
COVERAGE EXPECTED TO INCREASE EARLY THIS AFTERNOON ALONG FRONTAL
ZONE AS CONVERGENCE IN LOW LEVEL WIND FIELD INITIATES CONVECTION
IN WEAKLY UNSTABLE AIR MASS. GREATEST COVERAGE ANTICIPATED ACROSS
SOUTHERN WI/EASTERN IA AND NORTHWEST IL WHERE SOME LOW LEVEL
MOISTURE POOLING WITH YIELD MORE UNSTABLE CONDITIONS...THOUGH
CONVECTION ALLOWING MODEL GUIDANCE ALL TREND TOWARD SOME INCREASED
POTENTIAL ALONG THE FRONT AND COMBINED LAKE BREEZE BOUNDARY
INTO CHICAGO AREA AS WELL. SHRA/TSRA POTENTIAL LOOKS TO BE HIGHEST
LATER IN THE AFTERNOON INTO THIS EVENING. SCATTERED SHRA MAY
CONTINUE OVERNIGHT AS WELL...WITH SEVERAL MINOR UPPER LEVEL
DISTURBANCES PASSING ACROSS THE FORECAST AREA.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-LOW IN TIMING OF SHRA/TSRA DEVELOPMENT LATE MORNING INTO
EARLY AFTERNOON.
* MEDIUM IN DETAILS OF WIND SHIFT/SPEED WITH COMBINED FRONT/LAKE
BREEZE THIS AFTERNOON.
* MEDIUM-LOW IN SPECIFIC LOCATIONS OF TSRA THIS AFTERNOON.
RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z WEDNESDAY-12Z MONDAY...UPDATED 12Z...
TUESDAY NIGHT...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
RATZER
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENERALLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.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:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
606 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
&&
.AVIATION...
ISSUED 605 AM CDT Mon Aug 4 2014
Other than the threat for MVFR or local IFR vsbys in ground fog
over the next 60 to 90 minutes early this morning, VFR conditions
are expected this period. The main forecast challenge for later
today will be with the potential for TSRA, especially at KPIA
and KBMI as a weak cold front slips south into the lower Great
Lakes. Satellite data and surface observations indicate a band
of mid level clouds were tracking slowly east into west central
Illinois this morning. Bases of these clouds ranged from 5000 to
7000 feet with the overall movement mainly northeast. Forecast
soundings not showing much in the way of cumulus development excpt
across the far northern areas after 18z, but even there, it appears
to be mainly scattered at around 5000 feet. Will continue to include
a VCTS at PIA after 19z as this location will be closest to the
better instability. Not very confident after 00z with respect to
any of the convection that develops across the northwest to continue
across our area so will continue to hold off mentioning at any one
TAF site this evening. Surface winds will once again be a non-factor
with a southerly wind expected today at less than 10 kts, dropping
off to 5 kts or less aftr 00z.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
348 AM CDT MON AUG 4 2014
.DISCUSSION...
345 AM CDT
MAIN FORECAST CONCERNS/CHALLENGES ARE WITH PRECIP TRENDS THIS
MORNING THROUGH TONIGHT WITH SHOWER/THUNDERSTORM DEVELOPMENT
APPEARING LIKELY TODAY...AS WELL AS PRECIP CHANCES CONTINUING
THROUGH MID WEEK.
LATEST RADAR IMAGERY SHOWING CURRENT SHOWER/THUNDERSTORM ACTIVITY
REMAINING JUST NORTH OF THE CWA IN WISCONSIN AND NORTHEAST OVER
THE LAKE. NORTHWEST FLOW CONTINUING TO ALLOW MID LEVEL ENERGY TO
WORK ITS WAY SOUTHEAST THIS MORNING...WHILE SURFACE TROUGH AND
COLD FRONT MOVE SOUTH THROUGH SOUTHERN WISCONSIN. PREVIOUS
THOUGHTS OF BETTER WIDESPREAD CHANCES FOR SHOWERS AND
THUNDERSTORMS TODAY AND TONIGHT DO CONTINUE THIS MORNING...AND
HAVE REFLECTED THAT IN THE GRIDS BY MAKING SIGNIFICANT UPDATES TO
THE POPS THIS MORNING INTO THE AFTERNOON. SEVERAL PIECES OF
GUIDANCE THIS MORNING INDICATE THAT ISOLATED ACTIVITY EARLY THIS
MORNING WILL BEGIN INCREASING IN COVERAGE AS SOON AS MID/LATE
MORNING OVER THE ENTIRE CWA...AND HAVE TRENDED THAT WAY BRINGING
CHANCE POPS BY MID MORNING. COMPLEX SURFACE PATTERN APPEARING TO
BE LIKELY TODAY AS COLD FRONT TO THE NORTH SLOWLY PUSHES TO THE
SOUTH THIS MORNING...BUT IT DOES SEEM LIKELY THAT AS THIS FRONT
PUSHES THROUGH THE REGION IT WILL MOVE EASIER OVER THE LAKE. SHORT
TERM/HIGH RES GUIDANCE SHOWING THIS BOUNDARY PUSHING THROUGH
SOUTHERN LAKE MICHIGAN THIS MORNING AND THEN PUSHING INLAND BY
MID/LATE MORNING. THIS QUASI SYNOPTIC FRONT...LAKE BREEZE...WILL
THEN BE STRETCHED THROUGH NORTHERN ILLINOIS AND NORTHWEST INDIANA.
LIMITED CLOUD COVER WILL ALLOW GOOD INSOLATION WITH LOW LEVEL
LAPSE RATES ONCE AGAIN STEEPENING PRETTY QUICKLY THIS MORNING AND
WITH SUPPORT ALOFT OWING TO SEVERAL SHORT WAVE TROUGHS DROPPING
SOUTHEAST TOWARDS THE AREA...ISOLATED TO SCATTERED SHOWER AND
THUNDERSTORM DEVELOPMENT SHOULD OCCUR BY LATE MORNING. WHILE THIS
IS ONGOING...SURFACE LOW TO THE WEST WILL MOVE TOWARDS THE CWA
INTO THE AFTERNOON PROVIDING YET ANOTHER FOCUS FOR DEVELOPMENT. SO
HAVE INCREASED TO LIKELY POPS BY THE AFTERNOON FOR THE WESTERN HALF
OF THE CWA...AND HIGH CHANCE POPS FOR REMAINING AREAS. CONFIDENCE
IS NOT OVERLY GREAT WITH INTENSITY OF THE THUNDERSTORMS BUT WITH
SEVERAL FOCI FOR DEVELOPMENT AT THE SURFACE AND ALOFT...DECENT
MOISTURE AND INSTABILITY...COULD EASILY SEE AT LEAST SOME ISOLATED
STRONGER THUNDERSTORMS THAT COULD POSE A HAIL/WIND THREAT. WILL
INCREASE WORDING IN THE HWO TO MAKE MENTION OF THIS
POSSIBILITY...BUT WILL NEED TO CONTINUE TO MONITOR THE POTENTIAL
FOR AT LEAST AN ISOLATED SEVERE THREAT AS WELL. WOULD THINK THE
STORMS OVER THE WESTERN CWA TIED CLOSER TO BETTER TROUGH AND
INSTABILITY AXIS WOULD HAVE THE BETTER CHANCES FOR THIS STRONGER
DEVELOPMENT. NONETHELESS...WILL NOT EXCLUDE ANY AREAS FROM THIS
THREAT IN THE HWO PER PREVIOUSLY MENTIONED
FORCING/MOISTURE/INSTABILITY REASONING.
SURFACE TROUGH AND FRONT WILL SLIDE TO THE SOUTHEAST/EAST THIS
EVENING AND TONIGHT WITH PRECIP CHANCES REMAINING ACROSS THE CWA.
GUIDANCE DOES INDICATE THAT AS PRECIP SHIELD PUSHES THROUGH THE
CWA TONIGHT...INSTABILITY BECOMES MORE MEAGER. SO CONFIDENCE IS
STILL LOW DURING THIS TIME FRAME WITH INTENSITY BUT WITH FRONT
STILL LINGERING ACROSS THE CWA...THERE COULD STILL BE AN ISOLATED
STRONGER CHANCE. AS FRONT REMAINS IN PLACE...THERE WOULD BE A
BETTER POSSIBILITY FOR HEAVY RAIN AND LOCALIZED FLOODING THREAT
TONIGHT. HAVE ONLY CHANCE WORDING FOR TONIGHT MAINLY FOR LOWER
CONFIDENCE WITH OVERALL COVERAGE OF STORMS...BUT COULD SEE A TREND
TOWARDS INCREASING POPS FOR TONIGHT AS WELL. STILL LINGERING
FRONT/TROUGH OVER THE SOUTHERN CWA ON TUESDAY WILL PROVIDE CHANCES
FOR SHOWERS/THUNDERSTORMS ONCE AGAIN TUESDAY BEFORE A BRIEF DRY
PERIOD TUESDAY EVENING. GUIDANCE VARIES TUESDAY NIGHT INTO
WEDNESDAY WITH PLACEMENT AND TIMING OF NEXT POSSIBILITY FOR
SHOWERS AND THUNDERSTORMS...BUT AT THIS TIME IT DOES APPEAR
POSSIBLE OVER THE SOUTHERN THIRD OF THE CWA AS THE NEXT STRONGER
WAVE APPROACHES FROM THE NORTHWEST...ESPECIALLY DURING THE DAY
WEDNESDAY.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* WIND SHIFT TO EAST-NORTHEAST THIS AFTERNOON WITH COMBINATION OF
LAKE BREEZE/COLD FRONT.
* SCATTERED SHRA/TSRA FROM MID-DAY THROUGH THIS EVE.
RATZER
//DISCUSSION...UPDATED 06Z...
HIGH PRESSURE REMAINS ACROSS AREA EARLY THIS MORNING WITH WEAK
GRADIENT AND CONTINUED LIGHT/CALM WINDS. LIGHT WIND FIELD WILL
LIKELY AGAIN ALLOW LAKE BREEZE DEVELOPMENT BY AFTERNOON...WHICH
MAY COMBINE WITH A WEAK COLD FRONT MOVING SOUTH ACROSS WI/LAKE
MICHIGAN DURING THE DAY. TIMING OF WIND SHIFT TO EAST-NORTHEAST
BEHIND THIS BOUNDARY REMAINS QUESTIONABLE WITH VARYING MODEL
SOLUTIONS...BUT IT APPEARS WIND SHIFT SHOULD BE WORKING INTO FAR
NORTHEAST IL DURING EARLY AFTERNOON WITH WEAKENING WEST-SOUTHWEST
BOUNDARY FLOW ALLOWING IT TO PUSH ACROSS TERMINALS DURING THE
AFTERNOON. LIGHT EAST-NORTHEAST WINDS LIKELY TO PERSIST TONIGHT AS
FRONT SAGS SOUTH OF TERMINALS.
SHRA/TSRA...SEVERAL SMALL DISTURBANCES IN MID-LEVEL FLOW UPSTREAM
OF THE AREA EARLY THIS MORNING. COMBINED WITH WEAK DESTABILIZATION
NOTED IN FORECAST SOUNDINGS BY LATE MORNING/MIDDAY...SOME
POTENTIAL OF ISOLATED SHRA/TSRA WILL LIKELY EXIST PRIOR TO NOON.
GREATER THREAT WILL LIKELY BE TIED TO DIURNAL INSTABILITY PEAK
DURING THE AFTERNOON AND EARLY EVENING HOURS...AND LOW LEVEL
FORCING PROVIDED BY THE COLD FRONT/LAKE BREEZE BOUNDARIES. SOME
POTENTIAL MAY LINGER INTO TONIGHT AS MID-LEVEL TROUGH CONTINUES TO
DRIFT SOUTHEAST ACROSS AREA. OVERALL HAVE MOVED TIMING OF TSRA A
BIT SOONER THAN PREVIOUS FORECAST.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* LOW IN LAKE BREEZE AND COLD FRONTAL WIND SHIFT TIMING AND SPEED
BEHIND IT THIS AFTERNOON.
* MEDIUM IN SCATTERED SHRA/TSRA DEVELOPING AS EARLY AS MIDDAY AND
CONTINUING INOT THIS EVENING.
RATZER
//OUTLOOK FOR ORD/MDW FOR 12Z TUESDAY-12Z SUNDAY...UPDATED 00Z...
TUESDAY...SLIGHT CHANCE OF MORNING TSRA. EAST-NORTHWEST WINDS.
WEDNESDAY...SLIGHT CHANCE OF EVE TSRA. EAST-NORTHEAST WINDS.
THURSDAY...SLIGHT CHANCE OF TSRA. EAST-NORTHEAST WINDS.
FRIDAY-SATURDAY...VFR LIKELY. EAST WINDS.
MTF
&&
.MARINE...
221 AM CDT
A WEAK COLD FRONT WAS SAGGING SOUTH ACROSS LAKE MICHIGAN EARLY THIS
MORNING...AND WILL CONTINUE TO PUSH SOUTHWARD TODAY TO THE FAR SOUTH
END OF THE LAKE BY THIS EVENING. THE SURFACE PRESSURE GRADIENT
REMAINS FAIRLY WEAK ACROSS THE REGION...WITH WIND SPEEDS EXPECTED TO
REMAIN IN THE 10-15 KT RANGE BEHIND THE COLD FRONT TODAY. HIGH
PRESSURE WILL BUILD OVER THE NORTHERN LAKES TUESDAY...BRIEFLY
TIGHTENING THE GRADIENT A BIT OVER THE LAKE WITH WINDS AROUND 15 KT
AND PERHAPS A FEW GUSTS NEAR 20 KT FROM THE NORTH TUESDAY AFTERNOON
AND EVENING. THE HIGH WILL THEN DRIFT SLOWLY SOUTHEAST ACROSS THE
GREAT LAKES REGION DURING THE MID AND LATE WEEK PERIOD...WITH A
PROLONGED PERIOD OF LIGHT SYNOPTIC NORTHEAST-EAST-SOUTHEAST WINDS
AND DAILY LAKE BREEZES AS THE CENTER OF THE HIGH DRIFTS SOUTHEAST.
WAVES THROUGH THE PERIOD WILL GENEARLLY BE 2 FT OR LESS...WITH THE
EXCEPTION BEING TUESDAY/TUESDAY EVENING WHEN 3-4 FT WAVES ARE
EXPECTED ON THE SOUTHERN PART OF THE LAKES WITH THE STRONGER NORTH
WINDS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
253 AM CDT Mon Aug 4 2014
.DISCUSSION...
ISSUED 253 AM CDT Mon Aug 4 2014
SHORT TERM...Today through Wednesday
07z/2am surface map shows high pressure centered over West
Virginia, with low pressure over northern Kansas. Weak pressure
gradient between these two features has led to light/variable
winds and patchy fog across central Illinois early this morning.
Latest obs and HRRR guidance suggest fog may become most
widespread/persistent across the Wabash River Valley, so have
included patchy fog mention in the forecast for all locations
along/east of I-57 through 14z/9am. Next short-term issue will be
PoPs later today as cold front currently extending from southern
Wisconsin to South Dakota sags southward. Model solutions are
highly variable, with the NAM appearing to be too aggressive with
precip development and the ECMWF too scant. Prefer the 4km
WRF-NMM, which features very little in the way of precip through
midday, followed by scattered development across mainly the
western half of the KILX CWA this afternoon. With short-wave
trough evident on latest water vapor imagery over northwest Iowa
approaching from the northwest, this solution seems reasonable. As
a result, will carry chance PoPs along/northwest of a Danville to
Taylorville line this afternoon, with dry conditions expected
further southeast.
Cold front will settle into north-central Illinois tonight, as
Iowa upper wave passes through the area. With boundary in the
vicinity and adequate upper support present, think scattered
showers/thunder is a good bet across all but the far SE CWA. Areal
coverage of showers will gradually diminish on Tuesday as wave
exits the region, with mostly dry conditions expected across the
board by Tuesday night.
Best rain chances of the entire forecast period appear to be
setting up on Wednesday, as another upper wave tracks along the
stalled frontal boundary. Models are in relatively good agreement
that after a lull in the precip chances Tuesday afternoon/night,
showers/thunder will spread back into the area from the northwest
on Wednesday. Given forcing along boundary, good upper support,
and ample moisture as characterized by precipitable water values
of around 2 inches, have gone with high chance PoPs everywhere on
Wednesday into Wednesday night. Locally heavy rainfall will be
possible, particularly across west-central Illinois.
LONG TERM...Thursday through Sunday
Once the upper wave passes to the east, the frontal boundary will
get a push southward later in the week. Models have been struggling
with exactly how far south the front will drop, with poor
model-to-model as well as run-to-run consistency. Still feel the
trend will be for diminishing rain chances on Thursday and Friday
as front sinks into the Ohio River Valley. As a result, have
lowered PoPs to just slight chances along/north of I-74 Thursday,
then further south into the central zones by Friday. Further
south, have maintained chance PoPs across the southeast CWA on
both Thursday and Friday as a surface wave tracks along the front
and keeps rain chances alive there. After that, front will finally
drop far enough south to go with a dry forecast for next weekend.
Barnes
&&
.AVIATION...
ISSUED 1139 PM CDT Sun Aug 3 2014
Light fog is beginning to become more widespread in eastern
Illinois as far west as KDEC, which earlier briefly dipped to as
low as 1-1/2SM courtesy of the isolated showers from earlier.
Think that over the next 1-2 hours, MVFR visibilities should be
affecting all the TAF sites, with potential for some IFR
conditions again at KDEC. This should quickly lift Monday morning.
Focus beyond that is with an incoming cold front, which has the
potential for scattered storms by late afternoon near KPIA. Model
agreement has been mixed on how far east this boundary will make
it, and will hold off introduction at the other TAF sites for now,
although it would be most likely after 00Z if it did occur. Should
see scattered to broken clouds for most of the period after
sunrise, but likely to be at or above 7,000 feet based on forecast
soundings.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
624 PM CDT Tue Aug 5 2014
...Updated for Aviation...
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 309 PM CDT TUE AUG 5 2014
The primary focus will be convection this evening and how expansive
it will be this evening across western Kansas. Water vapor loop
early this afternoon showed a substantial mid level dry intrusion
into the southwestern CONUS which was pushing northeastward through
Colorado. RAP analysis revealed a fairly perturbed middle
troposphere from the primary vorticity anomaly across
central/northern California...eastward through Utah and into
Colorado. A 250mb jet streak continued to nose northeastward into
southern California through southern Utah. A lee trough convergence
axis was found across far southeastern Colorado into far
northwestern Kansas. This was on the western periphery of deep mid
level moisture plume. All the short-term high resolution models
suggest convection continuing to develop along the lee trough
convergence axis and also over terrain-favored regions of Colorado.
There is the suggestion that the most organized of lee trough
convection will stay just north of the DDC forecast area from far
west-central KS into northwestern KS. Both the 12Z WRF ARW and NMMB
show a cluster of pseudo-organized convection rolling east-southeast
reaching roughly a Leoti to Gove line by around 06Z. The best of the
lee trough convergence will be farther north, so it would make sense
that the high resolution models are keeping the most sustained
convection across northwestern Kansas. Other less organized
convection farther south may last through sunset, but not much after
that. We will keep Chance POPs confined to far west-central KS
(Kearny to Scott County). South winds tonight averaging 12 to 15
knots will keep the boundary layer mixed enough through the night
that temperatures will likely plateau during the 06-12Z time frame
in the lower 70s along/east of Highway 283. The trough axis will
shift east Wednesday with lighter winds much of the day across much
of southwest Kansas. Weak convergence along the trough may yield
late afternoon convection, but only loosely organized convection at
best can be expected with the deep frontogenetic forcing still north
of the southwest Kansas region through late afternoon Wednesday.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 246 PM CDT TUE AUG 5 2014
No significant changes were made to the extended period of the
forecast. Wednesday night, and through the overnight into Thursday
morning will present chances for convection along a weak boundary
and area of surface low pressure over western Kansas. The model
signals for this suggest the best chances for isolated to scattered
thunderstorms will be across central Kansas where instability and
CAPE will be greater. Any storms along this convergence zone should
end by Thursday morning across the south central Kansas counties
rendering Thursday dry for most of the day. Convection will again be
possible in the far west on Thursday evening and through the night
as it forms diurnally along the high terrain of eastern Colorado
with the aid of upslope surface flow and higher dew points around
60 degrees or more.
Beyond Friday, the region will remain in a fairly westerly zonal
pattern but also not a particularly strong surface gradient, leading
to relatively light winds. As the region will remain fairly rich
ion surface moisture and warm, any local areas of uncapped
convergence could set off afternoon convection lasting into the very
early evening through about Tuesday. However chances as far as areal
coverage are concerned should be fairly minimal.
&&
.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
ISSUED AT 616 PM CDT TUE AUG 5 2014
Some mid and high clouds will move east towards morning as an
upper trough moves east with VFR conditions expected. A few
thunderstorms are forecast by some models after midnight but
confidence is too low to put into the TAF. At the surface a weak
trough of low pressure will gradually move from the lee of the
Rockies and into far western Kansas by morning, then progress
toward the TAF sites during the mid to late morning and afternoon
with light south winds becoming light and variable.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 69 94 67 92 / 10 20 20 10
GCK 67 94 66 92 / 20 20 20 10
EHA 67 94 66 95 / 20 10 10 20
LBL 69 95 68 97 / 10 20 20 10
HYS 70 96 67 93 / 30 20 30 10
P28 71 94 70 95 / 10 20 30 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Russell
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
352 PM CDT Mon Aug 4 2014
...updated short term...
.SYNOPSIS...
ISSUED AT 349 PM CDT MON AUG 4 2014
Cirrus was slowly overspreading the western sections of Kansas from
the mean height ridge moving eastward from the Rockies into the High
Plains. A weak surface pressure/850 mb height gradient enveloped the
Central Plains. Relative low pressure over the eastern Colorado
resulted in a northward oriented pressure gradient gradient across
western Kansas resulting in generally south winds at most locations
with little downslope. Temperatures warmed to around 90 degrees
across in most locations as dew points mixed down to the upper 40s
from Scott City to Hugoton. Hays, which is closer to the warmer air
at 850 mb warmed into the upper 90s.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 349 PM CDT MON AUG 4 2014
The temperature trend and dew points to a lesser degree seemed to
have followed the consensus of the short term models blend fairly
well this afternoon. This trend will continue to be followed into
the rest of the forecast including Tuesday morning and into
Tuesday. The cirrus overhead may have a small impact on overnight
lows as the recent updates have bumped lows into the mid and upper
60s in most locations. The HRRR model continues to show isolated to
widely scattered convection across south central Kansas late this
afternoon likely based on reaching convective temperatures. Current
trends suggest this is overdone as was the case Sunday afternoon,
and PoPs will not be added at this time.
No major shift in airmass is taking place tonight and the same
general pattern of surface winds and diurnal warming is expected
heading into Tuesday afternoon. A breakdown in the ridge by a mid
level shortwave will create scattered convection across northeast
and east central Colorado by late in the afternoon. Low PoPs will be
included for about the western half of the area starting at about
about 23 UTC, following previous forecasts.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 341 PM CDT MON AUG 4 2014
The upper level ridge will flatten out and be shunted southward
during the next couple of days as a series of upper level
shortwaves move up and over the ridge. These features will bring a
chance of thunderstorms to the forecast area through this weekend.
The slight chance of thunderstorms will start out across far
western Kansas Tuesday night then across central Kansas Wednesday
night. Otherwise expect partly cloudy skies. Winds will generally be
from the south to south southwest Tuesday night through Thursday
with a surface trough located across eastern Colorado and far
western Kansas. A better chance of thunderstorms will be expected
this weekend as the upper level ridge slould retrogrades towards the
southwest United States. Winds will generally be from the southeast
during this time frame as a stationary front will be located at the
surface south of the area with a dome of high pressure to the north.
Highs through the extended period will generally be in the low to
mid 90s with lows in the upper 60s and lower 70s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 126 PM CDT MON AUG 4 2014
VFR conditions are expected through this TAF period. The only caveat
might be a few widely scattered weak high based CB`s mainly to the
east of the Dodge City and Hays terminals late in the afternoon
which would end with loss of surface heating as the Hi-Res Rapid
Refresh. Surface winds remain light through the period as well
before increasing to around 12-15 knots by around 15 UTC on Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 68 93 69 95 / 0 10 20 20
GCK 68 90 68 94 / 0 20 20 20
EHA 66 91 67 95 / 0 20 20 10
LBL 66 92 69 96 / 0 10 20 10
HYS 68 96 70 94 / 0 10 20 30
P28 68 93 71 94 / 0 10 20 30
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Hovorka_42
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1229 PM CDT Mon Aug 4 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 18Z TAFs through 18Z Tuesday Afternoon)
Issued at 1225 PM CDT MON AUG 4 2014
VFR conditions expected through the taf period. Winds overnight
will gradually veer to the east, and eventually the south by
tomorrow morning, but remain light though most of that time frame.
Isolated showers will dissipate after sunset.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...Sanders
AREA FORECAST DISCUSSION
NWS TOPEKA KS
639 AM CDT Mon Aug 4 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 12Z TAFs through 12Z Tuesday Morning)
Issued at 631 AM CDT MON AUG 4 2014
Isolated TSRA continues to develop and move southward near KFOE.
Mentioned VCTS with coverage being too low for prevailing TSRA.
Surface trough veers south winds today towards the west by late
afternoon and northeast near 00Z. Light and VRB winds are expected
thereafter. Isolated TSRA is possible at KTOP/KFOE during late
afternoon and early evening. Coverage is sparse and confidence in
development is too low for mentioning at this time.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS TOPEKA KS
345 AM CDT Mon Aug 4 2014
.SHORT TERM...(Today and Tonight)
Issued at 321 AM CDT MON AUG 4 2014
Weak mid level trough shifting southeast across northern MO this
morning with another shortwave trough noted over SD. A few isolated
showers have developed over far eastern KS this morning with weak
isentropic ascent in the presence of a 35 kt LLJ. While the HRRR is
overdone on coverage of showers, the ARW and NMM high-res guidance
is also picking up on a few isolated showers continuing through mid
morning. Will leave a slight chance mention through this time, but
confidence is low for measurable precipitation.
Showers over SD are progged to dissipate over NE while the upper
ridge to our west shifts east into the area today and tonight. At the
surface, the trough axis shifts southward, pushing a weak boundary
near the Interstate 70 corridor by afternoon. Strength of
convergence on the boundary varies by the model with the 06Z NAM
being the outlier and most progressive with mid 60 dewpoints creating
a more unstable and weakly capped boundary layer during peak
heating. All other short and mid term guidance points to weak
forcing on the boundary, subsidence aloft while mid-level ascent is
displaced further east. With some near sfc convergence along the
boundary, cannot completely rule out an isolated storm and will hold
onto slight chances for thunderstorms this afternoon through early
evening. Any storm that is able to develop may produce gusty winds.
850 mb thermal ridge axis spreads east during the day just above
20C, rising highs into the lower and middle 90s. Another upper
trough passes over Iowa and MO tonight, increasing scattered mid
level clouds and lows in the low 70s.
.LONG TERM...(Tuesday through Sunday)
Issued at 321 AM CDT MON AUG 4 2014
The long term period is rather unsettled with a consistent train
of weak disturbances (and a few more organized ones) crossing the
central plains through the coming week.
Tuesday looks to have the best chance of the coming week to be dry
as the local area should be in between weak disturbances and the
low levels should be somewhat dried out...limiting instability.
That said, it should also be the hottest day of the next week with
slight ridging overhead and likelihood of quite a bit of sunshine.
Expect highs from the lower 90s far northeast to the upper 90s in
north central KS.
By late Tuesday night, the short wave currently in the Las Vegas
area should move out across Nebraska along a stationary front just
north of the KS/NE border, and seems likely to support a broad
area of thunderstorm activity/MCS. The bulk of the storms Tuesday
night are likely to stay north of the forecast area but could get
a few storms to develop/move in after midnight. By Wednesday, the
front will move south into the area as a northern stream trough
dives into the Great Lakes and brings a cooler airmass south. The
frontal progression along with additional short waves moving
across the Plains from the southwest will provide a favorable
setup for one or more convective complexes to impact the forecast
area Wednesday afternoon through Thursday morning with additional
development on Thursday afternoon. Moderate instability and weak
shear through this period should mitigate the severe potential,
but locally heavy rainfall/flooding may become an issue depending
how these convective complexes evolve. Dry antecedent soil
conditions will mitigate the flood threat a bit, but still seems
possible if a backbuilding situation sets up.
Thunderstorm chances continue through the remainder of the
forecast period but confidence in the details of timing and
magnitude is not high. Expect days with moderate to strong
instability but wind shear looks to remain marginally adequate for
organized storms. Thunderstorm chances will also depend at least
somewhat on how far the front moves south of the area as a
drier airmass may try to push in from the northeast if the front
moves far enough south.
Temperatures will cool a bit after the Wednesday frontal passage
and highs should be a bit below normal in the mid to upper 80s for
the Thursday through Sunday time frame with lows in the middle to
upper 60s.
&&
.AVIATION...(For the 06Z TAFs through 06Z Monday Night)
Issued at 1149 PM CDT SUN AUG 3 2014
VFR conditions still anticipated. Chances for elevated convection
continue to wane but are not nil for at least the next few hours.
SW winds should pick up with mixing of the 25-30kt low level jet
per area radar winds. Winds weaken around 0Z as a low level trough
nears.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...Barjenbruch
AVIATION...65
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1200 AM CDT Mon Aug 4 2014
...Update to aviation...
.SHORT TERM...(This evening through Monday)
ISSUED AT 333 PM CDT SUN AUG 3 2014
This mornings convective allowing models allowed some room for
convection to develop once again just north of the I-70 corridor and
be driven southeast by the man flow, much like last evening. So far
this afternoon the area of enhanced cu development across northwest
Kansas has not shown signs of stronger shower or storm development
although the GLD 88D was indicating rain in the HCA. We will
continue to carry less than 20 PoPs trough the end of the afternoon
and early evening to see how this evolves, especially given the
increasingly robust HRRR model drives a few storms into Rush and
Stafford counties.
For the rest of the period including tonight into tomorrow, we
followed the NAM and Raw Model Blend which seemed to do the best job
collectively with temperatures and surface winds for yesterday.
little overall change in airmass will take place with the upper
ridge settling slightly farther east.
.LONG TERM...(Monday night through Sunday)
ISSUED AT 350 PM CDT SUN AUG 3 2014
Drier conditions will persist across western Kansas through early
Tuesday afternoon as an upper level ridge axis shifts eastward across
the Western High Plains. Medium range models then indicate the ridge
breaking down late Tuesday as a series of H5 vort maxima associated
with a shortwave eject out of the Rockies into the high plains of
western Nebraska and western Kansas. A developing lee side trough
will strengthen as the shortwave approaches while low/mid level
moisture continues to pool slowly across central and portions of
western Kansas. This will set the stage for possible thunderstorm
development across portions of southwest and central Kansas Tuesday
evening into Wednesday. Although low/mid level lapse rates will
steepen through the afternoon period Tuesday, NAM/GFS model
soundings show very little instability in regards to available CAPE
with values well under 100 J/KG. This will likely hinder storm
development through much of the afternoon with chances increasing
Tuesday evening as CAPE begins to rise. Although less than
favorable, a slightly strengthened flow aloft along with decent
directional shear may be enough to support stronger thunderstorms
with gusty winds the primary threat.
Precip chances will shift eastward across western into central
Kansas Wednesday as the surface trough migrates through.
Thunderstorms will be possible again into Thursday as H5 vort
maxima continue to move out of the Rockies into the Western High
Plains. However, better chances will be more to the north across
west central and central Kansas in association with the stronger
flow. Seasonal temperatures will continue through Thursday as a
south to southeasterly flow prevails through much of the period.
This will reinforce the warm air mass already in place across
western Kansas keeping highs up into the 90s(F) each day through
the end of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Monday night)
ISSUED AT 1200 AM CDT MON AUG 4 2014
VFR expected through TAF pd. Southerly winds will increase 12-18 kt
with gusts 20-25 kt by 18Z and through much of the afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 65 92 69 94 / 0 0 0 10
GCK 63 92 68 94 / 0 0 0 20
EHA 64 91 67 95 / 0 0 0 10
LBL 65 93 69 96 / 0 0 0 20
HYS 67 95 70 93 / 20 0 0 10
P28 66 93 69 94 / 0 0 0 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Russell
LONG TERM...JJohnson
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
506 AM EDT MON AUG 4 2014
LATEST UPDATE...
MESOSCALE DISCUSSION
.MESOSCALE DISCUSSION...
ISSUED AT 505 AM EDT MON AUG 4 2014
THERE IS A CLUSTER OF THUNDERSTORMS OVER SOUTHERN LAKE MICHIGAN
FROM WEST OF GLENN TO JUST NORTH OF BERRIEN COUNTY OFF SHORE. THE
STORMS HAVE MOVED INLAND TOO OVER EXTREME SOUTHWEST ALLEGAN AND
WESTERN VAN BUREN COUNTY. THESE STORMS ARE ASSOCIATED WITH A MESO-
LOW OVER SOUTHERN LAKE MICHIGAN. THE MIXED LAYER CAPE IS UNDER 250
J/KG AND THE MOST UNSTABLE CAPE NEAR 500 J/KG BUT NEARLY ALL OF
THAT IS ONLY OVER LAKE MICHIGAN. I WOULD EXPECT THE STORMS TO
CONTINUE TO DEVELOP OVER SOUTHEAST LAKE MICHIGAN UNTIL THE SUN
RISES ENOUGH TO MIX THE AIR. THIS IS SHOWN BY THE RAP MODEL WHICH
CONTINUES THE STORMS TILL AROUND 8-9 AM.
&&
.SYNOPSIS...
ISSUED AT 328 AM EDT MON AUG 4 2014
EXPECT SCATTERED THUNDERSTORMS TODAY INTO TONIGHT AS A WEAK
COLD FRONT MOVES SLOWLY SOUTH THROUGH THE AREA. TODAY WILL BE THE
LAST REALLY WARM DAY FOR WHILE. HIGH SHOULD REACH THE MID 80S IN
LAND AREAS. SOME LINGERING SHOWERS AND THUNDERSTORMS ARE POSSIBLE
TUESDAY THANKS TO AN UPPER LEVEL DISTURBANCE. BEYOND THAT COOLER
THAN NORMAL TEMPERATURES AND DRY WEATHER IS EXPECTED MOST OF THE
REST OF THE WEEK. A SLOW WARMING TREND STARTS FRIDAY AND CONTINUES
THROUGH SUNDAY.
&&
.SHORT TERM...(TODAY THROUGH WEDNESDAY)
ISSUED AT 328 AM EDT MON AUG 4 2014
THE PRIMARY ISSUE AS I SEE IT IS THE THREAT FOR THUNDERSTORMS
TODAY INTO TUESDAY MORNING. ANOTHER ISSUE IS JUST HOW WARM IT WILL
GET TODAY.
THERE IS A WEAK COLD FRONT SLOWLY MOVING SOUTH THROUGH THE STATE
OF MICHIGAN AS I WRITE THIS. THE PROBLEM THROUGH IS THERE IS NOT A
LOT OF PUSH BEHIND THE INITIAL COLD FRONT AND THE TEMPERATURE
GRADIENT BEHIND THE FRONT IS WEAK. MOSTLY DUE TO THE LACK OF ANY
SIGNIFICANT LOW LEVEL JET OR DECENT UPPER LEVEL JET. THAT DOES
CHANGE TONIGHT AS EXIT REGION OF A 85 KNOT JET CORE MOVES INTO THE
AREA. THAT THEN ALLOWS A BETTER PUSH OF THE COLD AIR SOUTH AND
CREATES A SORT OF SECONDARY FRONTAL BOUNDARY THAT TURNS SURFACE
WINDS TO THE NORTHEAST TONIGHT.
THERE IS AROUND 2000 J/KG OF MIXED LAYER CAPE INLAND OF US-131
THIS AFTERNOON SO EVEN WITH WEAK SURFACE CONVERGENCE I WOULD
EXPECT SOME THUNDERSTORMS. WITH A DECENT AMOUNT OF CAPE IN THE -10
TO -30 TEMP RANGE SOME STORMS COULD HAVE HAIL WITH THEM.
TONIGHT EXIT REGION DYNAMICS WILL AID CONVECTIVE DEVELOPMENT AND
THAT WILL CONTINUE INTO MIDDAY TUESDAY. BEYOND THAT HIGH PRESSURE
RULES AND IT WILL BE COOLER TOO.
.LONG TERM...(WEDNESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 328 AM EDT MON AUG 4 2014
THE MID RANGE MODELS ARE TENDING TOWARD A DRIER LONG TERM FORECAST
AND CONFIDENCE IS INCREASING. NO PRECIPITATION IN THE GRIDS... AS
RIDGING AND SURFACE HIGH PRESSURE TO COVER THE REGION.
TEMPERATURES WILL BE AROUND TO A LITTLE BELOW NORMAL FOR THE END OF
THE WORK WEEK AND SLOWLY WARM TO A LITTLE ABOVE NORMAL FOR THE
WEEKEND. NORMAL HIGHS ARE AROUND 80 DEGREES AND NORMAL LOWS ARE
AROUND 60 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1157 PM EDT SUN AUG 3 2014
LIGHT MVFR FOG/HAZE IS EXPECTED AGAIN OVERNIGHT AND EARLY
MONDAY... FROM ROUGHLY 09Z TO 14Z. VSBYS SHOULD BE MOSTLY 3-5
MILES BUT SOME IFR VSBYS UNDER 3 MILES CANNOT BE RULED OUT.
WIDELY SCATTERED SHOWERS AND TSTMS ARE EXPECTED MONDAY AFTERNOON
WITH THE EXCEPTION OF THE LK MI SHORELINE. WILL CARRY VCTS AFTER
18Z IN MOST OF THE TAFS ALTHOUGH LEFT THUNDER OUT OF THE TAF FOR
MKG DUE TO THE STABILIZING EFFECTS OF LK MI.
DIURNAL CONVECTION SHOULD WEAKEN MONDAY EVENING AFTER 01Z ALTHOUGH
SCATTERED SHOWERS MAY CONTINUE THROUGH MONDAY NIGHT AS SLOW MOVING
SFC FRONT SAGS SOUTH THROUGH SRN LWR MI.
&&
.MARINE...
ISSUED AT 328 AM EDT MON AUG 4 2014
THERE IS THE THREAT FOR THUNDERSTORMS TODAY INTO TUESDAY MORNING
BUT IT WOULD SEEM THE GREATEST CONCENTRATION OF THUNDERSTORMS
SHOULD BE WELL INLAND OF THE LAKE SHORE. STILL A FRONT IS A FRONT
SO THUNDERSTORMS ARE POSSIBLE EVEN SO TODAY INTO MID MORNING TUESDAY.
WINDS SHOULD BE FAIRLY LIGHT TODAY INTO TONIGHT AS THE FRONT
SLOWLY MOVES THROUGH THE AREA SO NO ISSUES WITH HIGH WINDS OR
WAVES. ON TUESDAY BEHIND THE COLD FRONT WINDS TO INCREASE A TOUCH
FROM THE NORTH BUT FOR THE MOST PART SHOULD STAY 1O KNOTS OR LESS
SO WE SHOULD STILL NOT HAVE ISSUES WITH LARGE WAVES OR SWIMMING
HAZARDS.
&&
.HYDROLOGY...
ISSUED AT 302 PM EDT SUN AUG 3 2014
NO HYDRO ISSUES EXPECTED OVER THE NEXT WEEK. THERE IS A POTENTIAL
FOR LOCALLY HEAVY RAIN IN THUNDERSTORMS MAINLY MIDDAY MONDAY THROUGH
EARLY TUESDAY MORNING. AFTER A COLD FRONT MOVES THROUGH EARLY
TUESDAY... DRY WEATHER IS EXPECTED THROUGH THE REST OF THE WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
MESOSCALE...WDM
SYNOPSIS...WDM
SHORT TERM...WDM
LONG TERM...63
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...WDM
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
303 PM CDT Mon Aug 4 2014
...An unsettled and wet weather pattern for the end of the
week...
.SHORT TERM...(This Evening through Tuesday)
Issued at 240 PM CDT MON AUG 4 2014
A nice cumulus field is developing with daytime heating and
instability this afternoon especially over southern Missouri.
There is a very subtle upper level shortwave moving through the
area this afternoon. The latest HRRR is indicating isolated to
scattered convection to develop by 22z near I-44 and move
southward into the early evening hours. Will still carry 20 to 30
percent pops for this general area into the evening hours.
Another upper level wave will move across the northern part of the
state by early tomorrow morning with some possible convection
making its way into central Missouri and the eastern Ozarks
tomorrow morning. Will carry a slight mention of pops for tomorrow
morning for this general area and a slightly better chance for
convection east of Highway 65 Tuesday afternoon.
.LONG TERM...(Tuesday Night through Monday)
Issued at 240 PM CDT MON AUG 4 2014
The upper level ridge of high pressure which has been in control
of our weather pattern will break down somewhat over us and allow
multiple shortwaves to ride down a west-northwest flow. A front
will meander into the region by Thursday and pretty much stall out
over the Missouri Ozarks or nearby through weekend.
There will be several rounds of convection and possible MCS
activity riding along that front through the area. The first chance
for widespread convection will be late Wednesday night into
Thursday morning with another rounds developing Thursday night
into Friday morning and possibly another round Friday night into
Saturday morning. Timing and exact placement is difficult to
pinpoint down at this time. The ECMWF is most bullish than the
GFS and GEM but all have the same idea.
Will mention a slight risk for heavy rainfall and some flash
flooding threat for the end of the week with widespread one to
three inches likely with isolated higher amounts over the eastern
Ozarks and central Missouri areas.
Temperatures by the end of the week will be dependent on where the
stalled front is positioned and on going convection and cloud
cover...but generally cooler temperatures in the lower 80s for the
eastern half of the CWA and upper 80s for southeast Kansas and far
southwest Missouri for the Thursday through Saturday time frame.
The front finally lifts back to the north or washes out by early
next week with temperatures moderating back to near normal and
slight pops lingering in the afternoon.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Pilots flying in and out of the southwest Missouri airports can
expect VFR conditions over the next 24 hours. However, we
recommend keeping an eye on radar trends this afternoon and
evening, as a few isolated thunderstorms could develop in some
places. Given the isolated nature of these storms, we did not
include a mention into the TAFS yet.
High pressure is directly over the region this afternoon, causing
winds to be light and variable. Surface winds will eventually
become more south or southeasterly tonight.
Safe Travels.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Griffin
LONG TERM...Griffin
AVIATION...Cramer
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1216 PM CDT Mon Aug 4 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 307 AM CDT Mon Aug 4 2014
Precip chances continue to be the primary forecast challenge in the
short range. Scattered thunderstorms are once again moving over
parts of northwest and west central Missouri this morning. RAP
shows an area of weak moisture convergence at 850mb which closely
conforms to the activity on radar at this time; so will go under the
assumption that this is what`s forcing the convection. The moisture
convergence continues basically over the same region through 12Z
before slowly weakening according to the RAP. Most operational
models tend to agree with the RAP and keep the vast majority of the
CWFA dry today. However, the NAM has other ideas and spreads this
moisture convergence eastward across much of Missouri into west
central Illinois by 00Z. This looks like it may be in response to
the subtle shortwave currently diving southeast along the South
Dakota/Nebraska/Iowa borders. NCEP and NSSL 4km WRFs both break out
convection over the area, which more closely supports the NAM
solution today. Further, the NAM and NCEP WRF handled yesterday`s
precip over central Missouri much better than the other models, so I
have more confidence in them than the rest of the suite. Have
therefore bumped up PoPs to mid-chance across much of central and
northeast Missouri into west central Illinois today, fading to low
chance/slight chance further to the southeast. Persistence highs
from 85-90 still look good for today.
Carney
.LONG TERM: (Tonight through Sunday)
Issued at 345 AM CDT Mon Aug 4 2014
The latest model data now advertises NW upper level flow persisting
over our region thru the next seven days--a bit of a departure from
what they were showing 2-3 days ago. The only real difference and
how to split the upcoming week is from amplified flow thru Tuesday,
from less amplified flow Wednesday into Saturday, before it becomes
amplified again with re-establishment of the western CONUS upper
ridge. Although with a couple of days of fairly steady model
output, confidence is increasing on the chances for some badly
needed rain for mid and late week, with additional chances today and
tomorrow simply as a bonus.
Decently moist air (1.5" or greater PWs) will already be in place
for most areas by early this evening and is anticipated to remain so
thru at least the end of the week with a period of 2" or greater PWs
late Wednesday into early Friday. It will be hard to find dry
periods in this forecast with a moisture regime such as this unless
we can also find an atmosphere nearly devoid of lift or convective
instability.
Leftover and what should be weakening convection is expected to once
again spillover for a short time early this evening before
retreating to northern MO and central IL where a frontal boundary
will be. But with anticipated propagation of TSRA from source
region to the south once again, like it is doing now, should see
chances for rain expand southward for most of the area late tonight,
all the while with the frontal boundary slowly pushing south.
Chances for TSRA on Tuesday will persist for areas near I-70 and
south where the weak frontal boundary will be before this is
expected to weaken/dissipate Tuesday night in favor of a stronger
wave of low pressure over the Plains and a likely MCS that will be
mainly to our north initially. Max temps on Tuesday should be in
the lo 90s for areas from I-70 and south with a hit of a few degrees
taken for areas further north with anticipated mild impact from the
front.
Models generally favor the lion`s share of the Tuesday night MCS to
miss us on Wednesday, with the best chances in central IL, but one
effect this should have is to once again shove the front further
south into our region Wednesday afternoon. Exactly when this
happens could have a BIG effect on our max temps Wednesday with hi
bust potential, but currently anticipating a delayed southward push
with decent warmup for the I-70 corridor and south--with readings
breaking 90 degrees. When the front does drop down, it should also
ignite TSRA later on Wednesday afternoon with some strong storms
possible.
The overall synoptic setup looks favorable for a more widespread
rain Wednesday night thru early Friday, with a surface front just to
the south of most of the area and a reasonably strong upper
shortwave TROF passing thru in a very moist environment. Expanded
on use of likely PoPs from previous shift with another round of
below normal temps looking much more likely as well.
Heading into next weekend, low confidence forecast returns again
with PoPs near or just a hair below climo with a not favorable
synoptic setup, but with persistent moist atmosphere, probably a
signal we are not seeing that will eventually result in a low PoP
forecast. Temps will make an attempt at returning towards
normal--which by now are now slowly declining as we have passed the
warmest climatological time of the year.
TES
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 1205 PM CDT Mon Aug 4 2014
High pressure remains over the region with a weak cold front
expected to sag south into northern MO Tuesday morning. This may
trigger some showers/thundertorms with the main activity being
further north over the upper Midwest. UIN looks to have the best
chance ovenigh with a prob30 possible after 06z. Otherwise nothing
strong to pinpoint so VCTS looks to be the main forecast tool.
Specifics for KSTL:
Can`t rule out a thunderstorms popping up this afternoon, but with
the 850MB high pretty much parked over the area, it does not look
favorable. Weak front sags into northern MO tonight. Will it make
it to STL? Always difficult to tell this time of year. If it does,
it ceratinly could increase chances of showers/thunderstorms, but
enough uncertainty remains to go no higher thatn VCTS. JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
308 AM CDT Mon Aug 4 2014
.SHORT TERM: (Through Late This Afternoon)
Issued at 307 AM CDT Mon Aug 4 2014
Precip chances continue to be the primary forecast challenge in the
short range. Scattered thunderstorms are once again moving over
parts of northwest and west central Missouri this morning. RAP
shows an area of weak moisture convergence at 850mb which closely
conforms to the activity on radar at this time; so will go under the
assumption that this is what`s forcing the convection. The moisture
convergence continues basically over the same region through 12Z
before slowly weakening according to the RAP. Most operational
models tend to agree with the RAP and keep the vast majority of the
CWFA dry today. However, the NAM has other ideas and spreads this
moisture convergence eastward across much of Missouri into west
central Illinois by 00Z. This looks like it may be in response to
the subtle shortwave currently diving southeast along the South
Dakota/Nebraska/Iowa borders. NCEP and NSSL 4km WRFs both break out
convection over the area, which more closely supports the NAM
solution today. Further, the NAM and NCEP WRF handled yesterday`s
precip over central Missouri much better than the other models, so I
have more confidence in them than the rest of the suite. Have
therefore bumped up PoPs to mid-chance across much of central and
northeast Missouri into west central Illinois today, fading to low
chance/slight chance further to the southeast. Persistence highs
from 85-90 still look good for today.
Carney
.LONG TERM: (Monday through Next Sunday)
Issued at 343 PM CDT Sun Aug 3 2014
(Monday - Tuesday)
Area of showers and storms from overnight convection is possible to linger
through the morning hours over northern and western portions of
the forecast area. If such an area exists early tomorrow
morning...it should slide south and east with the mid to upper-
level flow pattern. Isolated to scattered convection is possible
tomorrow afternoon as the ams destabilizes across the
area...especially across northern sections of the forecast area in
close proximity to warm frontal boundary/wind shift and area of
diffluence aloft. A few of these storms may be strong due to the
degree of instability forecast...however any kind of organized
strong storms looks unlikely due to very weak deep layer shear
(aob 25 knots).
Frontal boundary is expected to sag south a bit on Monday night and Tuesday
along with the continued chances of showers and thunderstorms. Lows Monday
night look to be near seasonal norms or slightly warmer than the previous
nights due to increased cloud cover and southerly flow across portions of
the area.
(Wednesday - Sunday)
Unfortunately...still plenty of uncertainty regarding PoPs and effects on
temperatures for the rest of the extended period. GFS/CMC are now much
further north with MCS progged for Wednesday compared to more consistent
ECMWF. Did not make too many changes Wednesday on compared to previous
forecast as GFS/CMC do look too far north and east with convection not only
on Wednesday but also through the work week looking at mid/upper level flow
pattern and NW-SE oriented baroclinic zone. Highest threat of rainfall still
looks to be somewhere in the Wednesday night through early Saturday time frame
but bountiful uncertainity/disagreement in track/timing on indiviudal
shortwaves precludes pin pointing any time period(s) with much higher PoPs
than previously forecast. Still does look like a wet and active pattern
for the mid/upper Mississippi Valley...just a matter of exactly where and
when.
Temperatures for the valid period look to be slightly below normal...mainly
due to daytime highs being cooler than normal because of clouds and rain
chances.
Gosselin
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1140 PM CDT Sun Aug 3 2014
Ongoing TSRA over nwrn MO shud move ewd very slowly tonight. These
storms shud remain N of COU based on latest guidance and trends.
However, uncertainty remains how far S the storms will develop.
The remnants of these storms shud provide a focus for
development in the UIN region Mon afternoon, but timing remains
uncertain. SUS is expected to see FG during the pre-dawn hrs once
again. Otherwise, SUS/CPS are expected to remain VFR and dry,
although can not rule out TSRA development during Mon afternoon in
the region. Winds are expected to remain sely to sswly aob 10 kts
thru the period.
Specifics for KSTL: VFR and dry thru the period with sely to sswly
winds aob 10 kts. TSRA may develop in the region Mon afternoon but
too much uncertainty exists attm.
Tilly
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 90 70 91 72 / 20 30 30 20
Quincy 86 65 86 67 / 40 40 20 30
Columbia 88 66 90 69 / 40 30 20 10
Jefferson City 89 67 90 69 / 30 30 20 10
Salem 86 65 89 67 / 10 20 30 20
Farmington 88 64 89 67 / 20 20 30 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1146 PM CDT Sun Aug 3 2014
.UPDATE:
Issued at 926 PM CDT Sun Aug 3 2014
Isolated thunderstorms have recently developed over western
Missouri in an area of 925-850mb moisture convergence. RAP shows
this area of forcing will spread eastward into central and
northeast Missouri after midnight. Going forecast handles this
trend well, so will keep chance of thunderstorms going in these
areas with slight chances all the way east to the St. Louis metro
area. Temperature and sky trends also match going forecast.
Britt
&&
.SHORT TERM: (Through Late Tonight)
Issued at 343 PM CDT Sun Aug 3 2014
The primary forecast issue for late this afternoon through the
overnight hours is convective trends. Ongoing isolated to scattered
SHRA/TSRA along an outflow boundary will probably keep percolating
late this afternoon in central MO, then diminish tonight with the
loss of daytime heating. Meanwhile, a vort max will dive south out
of the Dakotas, providing a source of lift for new development later
tonight. The 12z model runs did not seem to accurately capture the
strength of the vort max based on its presentation on today`s water
vapor imagery. The western edge of the aforementioned outflow
boundary was very pronounced on afternoon visible satellite imagery,
and initial thoughts are that scattered SHRA/TSRA could develop late
tonight in eastern KS or western/central MO due to lift over this
boundary occurring ahead of the approaching short wave from its weak
westerly LLJ. Limited moisture would tend to limit the coverage of
any precip which develops. Overnight lows should be similar to last
night in most locations, except a bit warmer due to increased
mid/high clouds after 06z which will interfere with radiational
cooling processes.
Kanofsky
.LONG TERM: (Monday through Next Sunday)
Issued at 343 PM CDT Sun Aug 3 2014
(Monday - Tuesday)
Area of showers and storms from overnight convection is possible to linger
through the morning hours over northern and western portions of
the forecast area. If such an area exists early tomorrow
morning...it should slide south and east with the mid to upper-
level flow pattern. Isolated to scattered convection is possible
tomorrow afternoon as the ams destabilizes across the
area...especially across northern sections of the forecast area in
close proximity to warm frontal boundary/wind shift and area of
diffluence aloft. A few of these storms may be strong due to the
degree of instability forecast...however any kind of organized
strong storms looks unlikely due to very weak deep layer shear
(aob 25 knots).
Frontal boundary is expected to sag south a bit on Monday night and Tuesday
along with the continued chances of showers and thunderstorms. Lows Monday
night look to be near seasonal norms or slightly warmer than the previous
nights due to increased cloud cover and southerly flow across portions of
the area.
(Wednesday - Sunday)
Unfortunately...still plenty of uncertainty regarding PoPs and effects on
temperatures for the rest of the extended period. GFS/CMC are now much
further north with MCS progged for Wednesday compared to more consistent
ECMWF. Did not make too many changes Wednesday on compared to previous
forecast as GFS/CMC do look too far north and east with convection not only
on Wednesday but also through the work week looking at mid/upper level flow
pattern and NW-SE oriented baroclinic zone. Highest threat of rainfall still
looks to be somewhere in the Wednesday night through early Saturday time frame
but bountiful uncertainity/disagreement in track/timing on indiviudal
shortwaves precludes pin pointing any time period(s) with much higher PoPs
than previously forecast. Still does look like a wet and active pattern
for the mid/upper Mississippi Valley...just a matter of exactly where and
when.
Temperatures for the valid period look to be slightly below normal...mainly
due to daytime highs being cooler than normal because of clouds and rain
chances.
Gosselin
&&
.AVIATION: (For the 06z TAFs through 06z Monday Night)
Issued at 1140 PM CDT Sun Aug 3 2014
Ongoing TSRA over nwrn MO shud move ewd very slowly tonight. These
storms shud remain N of COU based on latest guidance and trends.
However, uncertainty remains how far S the storms will develop.
The remnants of these storms shud provide a focus for
development in the UIN region Mon afternoon, but timing remains
uncertain. SUS is expected to see FG during the pre-dawn hrs once
again. Otherwise, SUS/CPS are expected to remain VFR and dry,
although can not rule out TSRA development during Mon afternoon in
the region. Winds are expected to remain sely to sswly aob 10 kts
thru the period.
Specifics for KSTL: VFR and dry thru the period with sely to sswly
winds aob 10 kts. TSRA may develop in the region Mon afternoon but
too much uncertainty exists attm.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
320 PM MDT MON AUG 4 2014
.SHORT TERM...VALID FOR TUE AND WED...
SCATTERED TO NUMEROUS SHOWERS AND STORMS ARE EXPECTED FROM TONIGHT
THROUGH TUE NIGHT WITH LOCALLY HEAVY RAINFALL A POSSIBILITY THANKS
TO ANOMALOUS ATMOSPHERIC MOISTURE CONTENT IN MONSOONAL FLOW. GIVEN
THE CONVECTIVE NATURE OF THIS SCENARIO...NOT EVERYONE IS LIKELY TO
RECEIVE HEAVY RAINFALL THOUGH.
AS OF MID AFTERNOON...SHOWERS AND STORMS ARE FILLING IN OVER SOUTH
CENTRAL MT AND NORTH CENTRAL WY AS FORCING WITH A LEAD AND DEFINED
SHORTWAVE IMPULSE HEADS NORTHWARD INTO THE REGION. MOST ALL OF THE
12 UTC GUIDANCE CONTINUED SHOWING MODERATE QG-FORCING SPREADING TO
THE NORTHEAST THROUGH TONIGHT...SO WE BELIEVE THE SHOWER AND STORM
ACTIVITY WILL FOLLOW SUIT. RECENT HRRR RUNS ARE ON BOARD WITH THIS
IDEA AND WE FOLLOWED ITS SOLUTION HEADING THROUGH THE EVENING WITH
LIKELY POPS SPREADING NORTHEASTWARD. THE SYNOPTIC-SCALE QG-FORCING
WITH THIS SHORTWAVE IMPULSE IS MAINLY RELEGATED TO SOUTHEASTERN MT
ON TUE...AND IT WILL BE DECREASING WITH TIME. HOWEVER...CONVECTION
SHOULD NONETHELESS BE DIURNALLY ENHANCED ACROSS THE ENTIRE AREA BY
AFTERNOON IN A MOIST AND WEAKLY UNSTABLE AIR MASS. THE 15 UTC SREF
SUPPORTS 300-800 J/KG OF SBCAPE...WEAK MID-LEVEL LAPSE RATES...AND
UNDER 25 KT OF 0-6-KM SHEAR...SUGGESTIVE OF SLOW-MOVING STORMS AND
LOCALLY HEAVY RAINFALL. MOST 12 UTC GUIDANCE...INCLUDING THE NCEP-
RUN CONVECTION-ALLOWING MODELS...SUGGEST THE MOST INTENSE ACTIVITY
OVER THE NEXT 48 HOURS MAY BE LATE TUE AFTERNOON INTO TUE NIGHT IN
SOUTHEASTERN MT. THAT IS REASONABLE AS THAT AREA MAY HAVE A BETTER
OPPORTUNITY TO DESTABILIZE WITH RELATIVELY GREATER CAPE SUPPORTIVE
OF MORE CONCENTRATED UPDRAFTS /DEPENDING ON THICKNESS OF CLOUDS/.
AS FOR THE HEAVY RAINFALL POTENTIAL...SPC SSEO OUTPUT REVEALS MEAN
RAINFALL TOTALS TONIGHT OF 0.20 TO 0.40 INCHES...AND THE 09 AND 15
UTC SREF RUNS SUGGESTED LESS THAN A 30 PERCENT PROBABILITY OF 0.50
INCHES OR MORE OF RAIN. DEEPER CONVECTION WILL YIELD LOCAL AMOUNTS
HIGHER THAN THAT...BUT THE STATISTICAL EVIDENCE POINTS AWAY FROM A
WIDESPREAD HEAVY RAIN EVENT. THE SREF DOES SUGGEST A HIGHER CHANCE
OF GREATER THAN A HALF INCH OF RAIN OVER SOUTHEASTERN IN THE BAKER
AND EKALAKA AREAS LATE TUE AFTERNOON INTO TUE NIGHT...MATCHING THE
SIGNALS SEEN IN THE 12 UTC DETERMINISTIC MODEL OUTPUT FOR A THREAT
OF MORE BONAFIDE HEAVY RAIN IN THAT PART OF SOUTHEASTERN MT.
BY WED...WEAK INSTABILITY WILL STILL EXIST AND IS SUFFICIENT FOR A
CHANCE OF SHOWERS AND STORMS...BUT GENERALLY-SPEAKING WE FEEL THAT
THE PROBABILITY WILL BE LOWER THAN TUE WITHOUT ANY DEFINED FORCING
ALOFT. HIGHS TUE WILL PROBABLY NOT REACH 80 F GIVEN THE CLOUDS AND
MOISTURE /AND WE DID LOWER HIGHS A BIT TOWARD THE 00 UTC CONSENSUS
OF RAW...2 M MODEL TEMPERATURE OUTPUT/...BUT THEY SHOULD WARM UP A
BIT AGAIN WED IF CLOUD COVER IS SOMEWHAT LESS THAT DAY. SCHULTZ
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
MODELS WERE IN PRETTY GOOD AGREEMENT THROUGH THE FORECAST PERIOD.
ENERGY GRADUALLY WORKS ACROSS THE FORECAST AREA THURSDAY AND
FRIDAY FOR WEAK LIFT AND SOME INSTABILITY. LINGERING MONSOON
MOISTURE WILL ALSO BE INVOLVED HERE SO NEED TO KEEP SOME MENTION
OF POPS. QUESTION FOR ME IS THE DRY AIR PRESENT ON WATER VAPOR
IMAGERY WORKING INTO SOUTHERN ARIZONA. HOW WILL THIS WORK TO DRY
OUT THE MONSOON PLUME WORKING INTO THE NORTHERN ROCKIES? THIS
COULD LIMIT THE CHANCE OF CONVECTION DESPITE THE TROUGH MOVING
THROUGH. ALL IN ALL...LOOKS LIKE THE DEEPEST MOISTURE WILL BE EAST
OF BILLINGS. DOES NOT LOOK OVERLY HOT THROUGH SATURDAY WITH
HEIGHTS STAYING BELOW 588DM. HEIGHTS BUILD LATE IN THE WEEKEND
INTO EARLY NEXT WEEK FOR WARMER WEATHER. TWH
&&
.AVIATION...
SHOWERS AND THUNDERSTORMS WILL SPREAD NORTHEAST TONIGHT. SOME OF
THE STORMS MAY CONTAIN HEAVY RAINFALL WITH LOCAL IFR CONDITIONS.
THE MOUNTAINS WILL BE MOSTLY OBSCURED. EXPECT ADDITIONAL SHOWERS
AND STORMS ON TUESDAY WITH MONSOONAL MOISTURE REMAINING IN PLACE
ACROSS SOUTHERN MT AND NORTH CENTRAL WY. SCHULTZ/TWH
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 063/079 059/084 060/087 061/088 061/090 062/090 062/090
75/T 42/T 22/T 22/T 21/U 11/B 11/B
LVM 054/078 052/083 053/084 053/086 053/087 054/090 053/089
75/T 43/T 33/T 32/T 22/T 22/T 22/T
HDN 064/081 059/086 058/088 059/089 059/091 060/091 061/092
76/T 52/T 22/T 22/T 21/U 11/B 11/B
MLS 067/080 062/082 060/087 063/090 063/091 063/092 064/092
67/T 62/T 22/T 22/T 21/U 11/B 11/U
4BQ 064/080 060/082 057/086 060/087 060/089 061/090 063/091
67/T 64/T 22/T 22/T 22/T 21/B 11/U
BHK 063/074 058/077 055/083 058/087 057/088 059/089 063/089
67/T 74/T 22/T 22/T 22/T 12/T 21/U
SHR 060/077 057/082 055/086 056/086 055/089 056/089 058/087
76/T 63/T 32/T 23/T 32/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1040 PM MDT Sun Aug 3 2014
UPDATED AVIATION SECTION
.DISCUSSION...
Update forthcoming. Thunderstorm activity continues to decrease.
Currently, the strongest storms are moving across eastern Fergus and
southern Blaine counties and should clear the area by midnight.
Additionally, showers are moving through southern Beaverhead County
at this time. Radar returns indicate isolated activity occurring
across southern Alberta and RUC analysis develops some qpf along the
International Boundary and the Hi-Line overnight. So have kept low
POPs there as well as along the Rocky Mountain Front and over
portions of southwest Montana. Monday looks to be another replay of
today. Overnight temperatures look good.
&&
.AVIATION...
UPDATED 0440Z.
Southwest flow aloft will continue to bring moisture to southwest
Montana. The airmass will become unstable again after 18z with
scattered showers and thunderstorms developing over the southwest
and then spreading north and east. Convective activity will continue
beyond 00z. VFR conditions prevail with MVFR conditions possible in
the vicinity of showers and/or thunderstorms along with erratic and
gusty winds.
&&
.PREV DISCUSSION...Issued 246 PM MDT Sun Aug 3 2014
Tonight through Tuesday...Short term forecast period continues to
be dominated by an upper level ridge over the western USA. As a
result, very little change is expected in the day to day forecast.
Very warm temperatures are expected each afternoon with winds
remaining generally light. Afternoon and evening thunderstorms are
expected each day...with isolated to scattered convection continuing
through the overnight and morning hours. Southwest Montana should
see the bulk of convection each day with numerous thunderstorms
expected Monday and Tuesday evening. Locally heavy rain, small
hail, gusty winds and occasional lightning strikes are expected to be
the main threats with any storms that develop. mpj
Tuesday Night through Sunday...A repeat of the current pattern
continues through the long term. Warm temperatures and isolated to
scattered thunderstorms will develop each afternoon, generally
starting up over terrain. With the showery nature of monsoonal
moisture, uncertainty remains with precipitation amounts and
coverage. Areas near higher terrain have the best chance of seeing
precipitation, namely the Continental Divide and Southwest
Montana. Latest model runs suggest a stronger push of moisture in
the Tue/Wed into Thu time frame. GFS brings in moisture over
Southwest Montana by Tue whereas the ECM holds it off until Wed.
There are also differences with placement as the ECM keeps
moisture a little more confined to the southwest. Did not jump on
either direction and went more in the middle of the two models.
Flow may become more westerly by the end of next week as high
pressure retreats southward a little bit. Not much in the way of
weather is expected though.
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 58 86 59 84 / 10 20 40 30
CTB 53 83 54 82 / 20 20 30 30
HLN 58 87 59 86 / 10 30 40 40
BZN 55 85 56 83 / 10 40 40 50
WEY 50 73 48 70 / 10 50 50 60
DLN 55 80 54 80 / 20 40 40 50
HVR 58 88 61 86 / 20 10 30 30
LWT 57 85 59 80 / 20 20 40 40
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
weather.gov/greatfalls
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AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1236 AM CDT MON AUG 4 2014
.SYNOPSIS...
ISSUED AT 345 PM CDT SUN AUG 3 2014
AT 19Z WATER VAPOR IMAGERY SHOWS THE CONTINUED WESTERN RIDGE/EASTERN
TROUGH PATTERN ONGOING. HOWEVER THERE IS A POTENT UPPER LEVEL LOW
MOVING INTO SOUTHERN CALIFORNIA ON THE WESTERN SIDE OF THE RIDGE.
ACROSS CANADA...COULD SEE A FEW NOTABLE SHORTWAVE TROUGHS...THE
FIRST OVER NORTHERN SASKATCHEWAN AND THE SECOND OVER SOUTHERN
BRITISH COLUMBIA. OTHER WEAK DISTURBANCES COULD ALSO BE SEEN
ROUNDING THE RIDGE AND MOVING THROUGH NORTHWEST FLOW INTO THE
CENTRAL PLAINS AND UPPER MISSISSIPPI RIVER VALLEY. LOCALLY...A WEAK
SURFACE BOUNDARY WAS SEEN FROM NORTHWEST NEBRASKA ARCING DOWN INTO
SOUTH CENTRAL NEBRASKA...ROUGHLY FROM KCDR TO KLBF TO KGRI.
TEMPERATURES HAD REACHED THE UPPER 80S AND LOW 90S MOST
PLACES...WHICH WERE AT OR NEAR FULL MIXING POTENTIAL. STARTING TO
SEE SOME CUMULUS POP UP ACROSS THE AREA...WHILE AREAL COVERAGE IS
LOW DUE TO A LACK OF MID LEVEL MOISTURE.
&&
.SHORT TERM...(TONIGHT THROUGH MONDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
ANY SHOWERS OR STORMS THAT DEVELOP ACROSS THE FORECAST AREA THIS
AFTERNOON DUE TO THE FAVORABLE LOW AND MID LEVEL CONDITIONS FOR GOOD
SB INSTABILITY WITH THE STEEP LOW AND MID LEVEL LAPSE RATES SHOULD
BE FAIRLY SHORT LIVED AND EXPECT ANY ACTIVITY TO END EARLY THIS
EVENING WITH THE LOSS OF DAYTIME HEATING AND STABILIZATION OF THE
BOUNDARY LAYER AS THERE WILL NOT BE SUPPORT ALOFT TO SUSTAIN ANY OF
THIS ACTIVITY.
ALTHOUGH IT IS DIFFICULT TO PICK OUT IN WATER VAPOR IMAGERY...MODELS
INDICATE A WEAK SHORTWAVE TROUGH OVER SOUTHERN MONTANA
CURRENTLY...WITH ANOTHER WEAK DISTURBANCE OVER WESTERN SOUTH DAKOTA.
THE SD SHORTWAVE MAY BRING ENOUGH LIFT TO BRING SOME SCATTERED
SHOWERS AND THUNDERSTORMS INTO NORTHWEST NEBRASKA THIS EVENING.
CONFIDENCE IS NOT HIGH IN THIS OCCURRING AS MOISTURE IS FAIRLY
LIMITED...BUT THE HRRR AND RAP HAVE BEEN CONSISTENTLY SIGNALING SOME
STRONGER CONVERGENCE AND LIFT IN THIS AREA SO WILL INCLUDE A SLIGHT
CHANCE IN THIS EVENING OVER THE NORTHWEST CORNER OF THE FORECAST
AREA. THEN OVERNIGHT...THE SHORTWAVE TROUGH OVER MONTANA WILL MAKE
ITS WAY INTO NORTH CENTRAL NEBRASKA. AS HAS BEEN OCCURRING FOR
SEVERAL DAYS...TEMPERATURES ARE COOL ENOUGH IN THE MID LEVELS TO
KEEP LAPSE RATES VERY STEEP AND EVEN SLIGHT LIFT FROM WEAK
SHORTWAVES SEEMS TO BE ENOUGH TO ALLOW STORMS TO DEVELOP
NOCTURNALLY. ALTHOUGH THERE IS QUESTION TO IF THERE WILL BE ENOUGH
MOISTURE TO WORK WITH...AND EXACTLY WHERE THE CHANCES WILL BE BEST
THE CURRENT THOUGHTS ARE THAT ACTIVITY WILL PASS ACROSS THE
NORTHEAST PART OF THE FORECAST AREA...ROUGHLY EAST OF A VALENTINE TO
TAYLOR LINE. THIS ENDS EARLY MONDAY MORNING.
THE UPPER LEVEL PATTERN DOES BEGIN TO SEE A SHIFT THROUGH THE DAY
MONDAY. THE UPPER LOW OVER CALIFORNIA WILL MOVE INTO THE RIDGE WHICH
WILL CAUSE THE RIDGE TO START SHIFTING EAST. MEANWHILE...THE
SHORTWAVE OVER SASKATCHEWAN WILL DIVE INTO THE GREAT LAKES REGION TO
PUSH A COLD FRONT THROUGH THE UPPER MISSISSIPPI RIVER VALLEY AND
APPROACH NORTHEAST NEBRASKA BY THE END OF THE DAY. ALSO...THE
BRITISH COLUMBIA SHORTWAVE WILL START SLOW EASTERLY MOVEMENT WHICH
WILL PLAY THE PART OF FLATTENING THE RIDGE. THIS MOVEMENT IN THE
UPPER LEVELS WILL LEAD TO LOW PRESSURE DEVELOPING OVER THE LEE SIDE
OF THE ROCKIES TONIGHT AND MONDAY...WITH WINDS IN TURN SWITCHING
AROUND TO THE SOUTH BY MONDAY MORNING. EXPECTING THE WINDS TO
INCREASE THROUGH THE DAY AS THE PRESSURE GRADIENT TIGHTENS. AS THE
RIDGE SHIFTS EAST...TEMPERATURES ALOFT WILL WARM ON MONDAY. CURRENT
700MB TEMPERATURES IN THE UPPER SINGLE DIGITS LOOK TO INCREASE TO
11-13C BY 00Z TUESDAY SO SHOULD HAVE THE POTENTIAL FOR A SLIGHTLY
WARMER DAY FOR MOST LOCATIONS FOR MONDAY WITH FORECAST HIGHS FROM
AROUND 90 TO THE MID 90S NORTHEAST TO SOUTHWEST.
MAINTAINED THE SLIGHT CHANCES FOR SHOWERS AND STORMS ACROSS THE
NORTH AND WEST MONDAY AFTERNOON. A SHORTWAVE MOVES TOWARDS NEBRASKA
IN THE AFTERNOON OUT OF WYOMING AND COLORADO...HOWEVER THE TIMING
LOOKS BETTER WITH THIS INTO THE EVENING. THE MODELS DO CONTINUE TO
DEVELOP PRECIPITATION OVER NORTHERN NEBRASKA IN THE AFTERNOON AS
MOISTURE POOLS ALONG A BOUNDARY IN THE VICINITY OF THE NE/SD BORDER.
DEWPOINTS RISE INTO THE UPPER 50S AND 60S AT THE SURFACE AND MID
LEVEL MOISTURE INCREASES...AND WITH LOW LEVEL LAPSE RATES STAYING
STEEP...PRECIPITATION CONTINUES TO LOOK POSSIBLE. INSTABILITY ISN/T
GREAT...WITH MU VALUES BEING UP TO 1000 J/KG...BUT DEEP LAYER SHEAR
WILL BE INCREASING SO COULD GET A FEW CELLS TO ORGANIZE IN THESE
AREAS TO GET A FEW STRONGER STORMS. WIDESPREAD SEVERE WEATHER IS NOT
ANTICIPATED.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 345 PM CDT SUN AUG 3 2014
A PATTERN SHIFT WILL LEAD TO A SURFACE LOW AND ASSOCIATED FRONTAL
SYSTEM MOVING SOUTHEAST MONDAY THROUGH WEDNESDAY NIGHT. A HIGHER
CHANCE FOR THUNDERSTORMS OCCURS TUESDAY NIGHT AS SEVERAL
DISTURBANCES MOVE EAST. THE PRECIPITABLE WATER RATIOS WILL BE
HIGHER WHERE HEAVY RAIN IS POSSIBLE WITH THUNDERSTORMS THAT MAY
FORM. AS THE FRONT MOVES EAST AND SOUTH THURSDAY THE TRAILING END
OF THE FRONT BACKS WEST AND NORTHWEST THROUGH THE WESTERN
PANHANDLE. IF THE FRONT STALLS ACROSS NORTHERN KANSAS AS SHOWN...A
PREVAILING EASTERLY SURFACE FLOW WOULD INCREASE THE MOISTURE
SUPPLY FOR INCREASED CLOUDS INTO THE EXTENDED PERIOD. A CHANCE OF
THUNDERSTORMS DAILY LINGERS AS THE STALLED BOUNDARY TO THE SOUTH
WOULD KEEP TEMPERATURES CLOSER TO NORMAL...OR BELOW NORMAL
...GOING FORWARD WITH DAYTIME HIGHS IN THE 80S OVER THE
SOUTHWEST...AND 70S IN THE NORTH AND NORTH CENTRAL. MODEL
CONSENSUS DIVERGES BEYOND WEDNESDAY NIGHT WITH A SUPERBLEND OF THE
SOLUTIONS USED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1235 AM CDT MON AUG 4 2014
THERE IS STILL A POSSIBILITY OF SHOWERS ALONG THE NEBRASKA-SOUTH
DAKOTA BORDER TONIGHT IN THE 07-12Z PERIOD. THE RAPID UPDATE
SHORT RANGE MODELS INDICATE THAT. IT IS POSSIBLE THAT CEILING
WILL BE LESS THAN 3000 FEET AGL WITH VISIBILITY LESS THAN
5SM...BUT ONLY ONE SIMULATION INDICATES THAT. THAT RESULTS IN
CONSIDERABLE UNCERTAINTY. OTHER SHORT RANGE PROJECTIONS HINT AT
CEILING BELOW 1000 FEET...BUT THERE IS NO CONSENSUS ON THE
LOCATION. FOR THE TIME BEING...THEN...WE WILL KEEP CEILING ABOVE
3000 FEET AGL AND VISIBILITY AT OR ABOVE 5SM IN THE TERMINAL
FORECAST FOR VTN.
WITH NO SIGNIFICANT CHANGE IN THE WEATHER PATTERN...ISOLATED
THUNDERSTORMS CAN BE EXPECTED AGAIN MONDAY EVENING. CURRENT
INDICATIONS ARE THAT THEY WILL BE ALONG THE NEBRASKA-SOUTH DAKOTA
STATE LINE JUST WEST OF VTN. HOWEVER...WITH MUCH UNCERTAINTY IN
THE LOCATION AND TIMING...THEY WILL NOT BE INCLUDED IN THE
TERMINAL FORECASTS FOR LBF AND VTN AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 345 PM CDT SUN AUG 3 2014
ON THE NORTH PLATTE RIVER...FROM LAKE MCCONAUGHY DOWNSTREAM TO
BRADY...IRRIGATION RELEASES CONTINUE TO SLOWLY CREEP UP THE FLOWS
WITH THE CURRENT STAGE AT THE NORTH PLATTE GAGE AT 5.4 FEET. THE
RIVER FORECAST FOR THE NORTH PLATTE GAGE...NEAR THE HIGHWAY 83
BRIDGE...IS FOR FLOWS TO REMAIN AROUND 5.5 FEET THROUGH THURSDAY.
THERE IS A CHANCE FOR THUNDERSTORMS DAILY WHERE SOME FLUCTUATIONS
ARE POSSIBLE.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...BROOKS
SHORT TERM...BROOKS
LONG TERM...KECK
AVIATION...MASEK
HYDROLOGY...KECK
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
522 PM MDT TUE AUG 5 2014
.AVIATION...
00Z TAF CYCLE
VFR TERMINALS WITH LIGHT WINDS TO PERSIST THROUGH THE TAF PERIOD.
CURRENT ROUND OF CONVECTION IS FORECAST TO DIMINISH RAPIDLY AFTER
SUNSET. KTCC MAY BE IMPACTED BETWEEN 01-03Z...BUT PROBABILITY TOO
LOW TO INCLUDE IN TAF.
11
&&
.PREV DISCUSSION...255 PM MDT TUE AUG 5 2014...
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL FAVOR EASTERN NEW MEXICO THROUGH
THE EVENING HOURS. A FEW STORMS MAY PRODUCE GUSTY WINDS AND HAIL.
ON WEDNESDAY...STORM COVERAGE WILL DECREASE SIGNIFICANTLY AS DRY
AIR CONTINUES TO MOVE INTO THE STATE. IF STORMS DEVELOP...THEY WILL
FAVOR THE SOUTHWEST AND SOUTH CENTRAL MOUNTAINS. MEANWHILE...
TEMPERATURES WILL CLIMB NEAR OR ABOVE SEASONAL NORMALS. MOISTURE
WILL SLOWLY START TO MOVE FROM SOUTH TO NORTH...BACK INTO THE LAND OF
ENCHANTMENT...THURSDAY THROUGH THE WEEKEND. STORM COVERAGE WILL
SLOWLY START TO INCREASE...AND THE POTENTIAL FOR HEAVY RAIN WILL
RETURN. HOWEVER...OVERALL COVERAGE IS EXPECTED TO BE LESS THAN
RECENT WEEKS.
&&
.DISCUSSION...
MUCH DRIER MID AND UPPER LEVEL AIR MOVING INTO NM PER WV SATELLITE
IMAGERY AND 12Z FGZ SOUNDING. AS SUCH...CONVECTION HAS REALLY
STRUGGLED TO START...OR MAINTAIN ITSELF WEST OF THE CENTRAL MTN
CHAIN. MID LEVEL MOISTURE GRADIENT LIKELY SETTING UP ALONG THE
CENTRAL MT CHAIN...AND THIS COMBINED WITH OROGRAPHIC LIFT HAS
PRODUCED A FEW SHOWERS AND TSTMS. WITH THE AID OF A WEAK 700 MB
TROUGH ACROSS NORTHERN NM...AND DRY AIR PUNCHING INTO MID
LEVELS...HAVE ALREADY SEEN ONE SEVERE STORM ACROSS THE NE...AND A
FEW MORE STRONG OR SEVERE STORMS ARE NOT OUT OF THE QUESTION.
QUARTER SIZE HAIL AND GUSTY WINDS WOULD BE THE MAIN THREATS. THE
GOOD NEWS IS THAT WITH STORM MOTIONS AVERAGING 10 TO 20 MPH...THE
THREAT FOR FLOODING HAS CONSIDERABLY DECREASED...THOUGH ALSO NOT OUT
OF THE QUESTION. LATEST AVAILABLE HRRR SUGGESTS THAT MUCH OF THE
CONVECTION TONIGHT WILL DIMINISH BY SUNSET.
DRY AIR CONTINUING TO FILTER IN COMBINED WITH THE UPPER LEVEL HIGH
BUILDING BACK TO THE NORTH WILL RESULT IN AN EVEN BIGGER DOWN TICK
IN STORM COVERAGE ON WEDNESDAY. PWATS LOOK TO CRATER TO AROUND 0.50
INCHES...SIMILAR TO WHAT WAS OBSERVED ON THE FGZ SOUNDING THIS AM.
TEMPERATURES WILL CLIMB SEVERAL DEGREES...WITH ALL AREAS SEEING NEAR
TO ABOVE NORMAL TEMPS FOR THE FIRST TIME IN A WHILE.
MODELS SUGGEST THE UPPER HIGH WILL INCH EASTWARD ON THURSDAY...AS
SOME DISTURBANCE...LIKELY FROM THE PREVIOUS DAYS CONVECTION OVER
MEXICO...WILL MOVE NORTHWARD INTO SOUTHERN NM. PWATS WILL CREEP UP
ON THURSDAY...BUT WILL REMAIN BELOW NORMAL FOR THIS TIME OF YEAR.
NONETHELESS... A FEW MORE STORMS WILL BE POSSIBLE AT LEAST ACROSS
THE SOUTHERN TIER OF THE CWA ON THURSDAY. ADDITIONALLY...THE NAM IS
SUGGESTING AREAS ALONG AND JUST EAST OF THE CENTRAL MT CHAIN WILL BE
A FAVORED AREA FOR STORM DEVELOPMENT. CONTINUED TO CARRY HIGHER POPS
HERE...BUT NOT OVERLY SOLD YET. NEAR AND BEHIND A BACK DOOR FRONT
WITH AMPLE LOW LEVEL MOISTURE BEHIND IT ACROSS THE FAR NE MAY BE A
BETTER BET FOR STORMS.
LOOKING FOR A BIT MORE MOISTURE ON FRIDAY AS THE UPPER HIGH SHIFTS
OVER OKLAHOMA...THOUGH MODELS ARE NOT VERY AMBITIOUS AT BRING THE
MOISTURE NORTHWARD DESPITE THE FAVORABLE PATTERN. THIS MAY CHANGE IN
THE COMING DAYS. THE WEEKEND DOES NOT LOOK TOO MUCH DIFFERENT FROM
FRIDAY...OTHER THAN THERE MAY BE A BIT MORE MOISTURE AND STORMS
AROUND. PWAT VALUES ARE PROGGED TO BE RIGHT AROUND NORMAL FOR
AUGUST. LOOKS LIKE EARLY NEXT WEEK THE UPPER HIGH WILL SHIFT BACK
OVER NM...DIVERTING THE MOISTURE PLUME WESTWARD OVER ARIZONA.
34
&&
.FIRE WEATHER...
NO MAJOR CHANGES TO THE GRIDDED FORECAST. DID LOWER DEWPOINT
VALUES THUS RH ACROSS MOST OF THE FORECAST AREA DURING THE NEXT
FEW DAYS. DESPITE THE DYNAMIC DRY SLOT/MID LEVEL DRY INTRUSION
PATTERN...VEGETATION WILL BE GOING OVERTIME IN TERMS OF
TRANSPIRATION AT NIGHT SO RAISED OVERNIGHT DEWPOINT VALUES SOME
ACROSS THE EAST. MOIST SOILS WILL ALSO KEEP DEWPOINT READINGS FROM
FALLING TOO FAR BELOW MODEL GUIDANCE. WENT WITH MORE OF A MODEL
BLEND. EITHER WAY...HUMIDITY VALUES FALL BELOW SEASONABLE LEVELS
WED/THUR PRETTY MUCH AREAWIDE. THEN MORE SEASONABLE READINGS
EXCEPT FOR THE FOUR CORNERS BY FRIDAY AND LASTING INTO THE
WEEKEND. LOOKING AT SOME SINGLE DIGIT RH READINGS FOR THE FOUR
CORNERS DURING THE UPCOMING FEW DAYS SO PAY MORE ATTENTION TO FIRE
STARTS UP THAT BECAUSE OF THE DRIER CONDITIONS.
AS FAR AS WETTING RAIN...OVERALL COVERAGE WILL DECREASE PRETTY
SIGNIFICANTLY COMPARED TO THE PAST WEEK. A FEW WETTING STORMS
FAVORING THE EASTERN THIRD TO HALF WILL OCCUR REST OF TODAY BUT
PRETTY ISOLATED. THE DRIER AIR ALOFT WILL KEEP CELLS PRETTY LIMITED
WEDNESDAY. A BAGGY TROUGH OR WEAKNESS TO THE WEST OF THE STATE
WILL EVENTUALLY DRAW SOME MOISTURE NORTHWARD FROM MEXICO AS THE
WEEK PROGRESSES. THIS LOOKS TO BE A SLOW TRANSITION IN TERMS OF
WETTING RAIN COVERAGE BUT THE TRANSITION WILL OCCUR BASED ON MODEL
COMPARISONS THE PAST DAY OR SO AND TAKING INTO ACCOUNT THE TIME OF
YEAR. THE UPPER RIDGE TODAY WILL HAVE SAGGED SOUTHWARD OVER
NORTHERN MEXICO BUT AS THE WEEK PROGRESSES LOOK FOR IT TO TRY TO
STRENGTHEN NORTHWARD AND EVENTUALLY GET SHUNTED EASTWARD DUE TO
THE WESTERN TROUGH. THE NECESSARY DRIVERS OR INGREDIENTS WOULD BE
IN PLACE TO DRAW MONSOONAL MOISTURE NORTHWARD FROM MEXICO. THE
MAIN QUESTION IS HOW QUICKLY.
TEMPERATURES DURING THIS PERIOD WOULD EVENTUALLY WARM SOME BUT
HIGHS WOULD GENERALLY BE NEAR TO SLIGHTLY BELOW NORMAL WEST AND
NEAR TO SLIGHTLY ABOVE NORMAL EAST. OVERALL WIND SPEEDS LOOK TO BE
ON THE LIGHTER SIDE DUE TO THE LACK OF ANY SURFACE OR UPPER LEVEL
DRIVERS. THE STRONGEST WIND FOR THE FORECAST AREA LOOKS TO BE
TODAY AND FAVOR THE EAST. ANY THUNDER CELLS THAT DO DEVELOP COULD
CONTAIN STRONG OUTFLOW WINDS DUE TO THE MID LEVEL/SFC DRYING.
LOOKING AT A RETURN TO SOME HAINES 5/6 VALUES DURING THE NEXT FEW
DAYS. HAINES 6 MOST LIKELY ACROSS THE FOUR CORNERS THURSDAY.
VENTILATION LOOKS TO BE PRETTY DECENT MOST AREAS THROUGH THE END
OF THE WEEK BUT LOWER SOME DURING THE WEEKEND.
GFS/ECMWF SHOWS SOME CONTINUED ATMOSPHERIC MOISTENING DURING THE
WEEKEND INTO EARLY NEXT WEEK AS THE MEAN HIGH PRESSURE CELL
PLACEMENT WOULD BE TO THE EAST OF THE STATE. STILL LOOKING AT A
BAGGY TROUGH TO THE WEST. THUS...THE MONSOONAL MOISTURE PLUME
SHOULD EVENTUALLY CONCENTRATE ITSELF OVER PORTIONS OF AZ/NM. HOW
MUCH AND EXACT PLACEMENT IS STILL A LITTLE TRICKY. ANOTHER FLY IN
THE OINTMENT WOULD BE AN EASTERLY WAVE COMING OFF THE GULF OF
MEXICO. IT IS MOST PROBABLE THAT THIS EASTERLY WAVE WOULD DRAG
DRIER MID LEVEL AIR OVER PORTIONS OF THE FORECAST AREA VERSUS
PROVIDING A MOISTENING TREND BUT HAVE TO WAIT AND SEE. A PRETTY
TYPICAL PERIOD FOR THE WET PHASE OF THE MONSOON SUMMER PERIOD SO
NOTHING REAL UNUSUAL UPCOMING.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1007 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED TODAY MAINLY ALONG THE COAST. BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...LATEST SFC OBS FROM ACROSS THE REGION
ILLUSTRATES AN IMPROVEMENT TO HORIZONTAL VSBY ABOVE 1 MILE. THIS
TREND WILL CONTINUE...ALBEIT SLOWLY...FOR THE REMAINDER OF THE
MORNING. THEREFORE...THE DENSE FOG ADVISORY IS NO LONGER NEEDED.
LOW STRATUS WILL TAKE A BIT LONGER TO AT LEAST IMPROVE ABOVE 1K
FEET. NEVERTHELESS...SKY CONDITIONS WILL REMAIN OVERCAST ACROSS
THE MAJORITY OF THE FA...WITH ANY TEMPORARY PEAKS OF THE SUN
OCCURRING WEST OF THE I-95 CORRIDOR.
STATUS QUO FOR THE FLOOD WATCH ACROSS THE FA...WHICH LIES
BASICALLY EAST OF THE I-95 CORRIDOR TO THE CAROLINA COASTS. ENOUGH
POTENTIAL FOR WIDESPREAD ONE HALF TO 1 INCH RAINFALL AMOUNTS WITH
POCKETS OF GREATER THAN 1 INCH AMOUNTS REMAINING POSSIBLE.
A STALLED FRONTAL BOUNDARY LIES PARALLEL TO THE CAROLINA
COASTLINES WITH AMPLE CONVECTION ALONG AND EAST OF THIS FRONT AND
STRATIFORM RAINS WEST OF THIS BOUNDARY. OCCASIONALLY...CONVECTION
WILL AT TIMES PUSH ONSHORE...WITH ADDITIONAL PCPN DEVELOPMENT
ACROSS THE INLAND PORTIONS OF THE FA AS THE DAY PROGRESSES.
PREVIOUS DISCUSSION..................................................
AS OF 645 AM MONDAY...THE 06Z NAM APPEARS TO BE CATCHING ONTO THE
TRENDS ESTABLISHED EARLIER BY THE GFS AND HRRR...AND IS LOWERING
ITS RAINFALL POTENTIAL ALONG AND WEST OF INTERSTATE 95 LATER
TODAY. BASED ON THIS AND RECENTLY OBSERVED RADAR TRENDS
OFFSHORE...I HAVE TRIMMED BACK BOTH RAINFALL PROBABILITY AND
AMOUNT FORECASTS AWAY FROM THE IMMEDIATE COAST TODAY. THIS HAS
GIVEN ME ENOUGH CONFIDENCE TO DROP THE FLOOD WATCH FOR THE REST OF
THE INTERIOR PEE DEE COUNTIES AND ROBESON COUNTY...LEAVING IT IN
EFFECT ONLY FOR THE COASTAL COUNTIES PLUS BLADEN AND COLUMBUS
COUNTIES. FOR BLADEN AND COLUMBUS THE WATCH IS UP MAINLY DUE TO
WATERLOGGED SOILS FROM OVER HALF A FOOT OF RAIN THAT FELL BETWEEN
ELIZABETHTOWN AND WHITEVILLE YESTERDAY.
ALSO...RECENT ASOS OBSERVATIONS REVEAL A GROWING AREA OF 1/4 MILE
VISIBILITIES ACROSS THE INTERSTATE 95 CORRIDOR. A DENSE FOG
ADVISORY HAS BEEN ISSUED HERE THROUGH 9 AM. PREVIOUS DISCUSSION
FROM 300 AM FOLLOWS...
THE RISK OF EXCESSIVE RAINFALL TODAY IS HIGHEST ALONG THE GRAND
STRAND BEACHES NORTHWARD INTO COASTAL SE NORTH CAROLINA. A STALLED
FRONT EXTENDING FROM THE FLORIDA EAST COAST NORTHWARD TO VERY NEAR
WILMINGTON SHOULD MOVE LITTLE THROUGH DAYBREAK. MODELS SHOW THE
BOUNDARY DRIFTING WESTWARD LATE THIS MORNING...BUT THEN RETREATING
BACK OFFSHORE THIS EVENING AS THE INCREASINGLY BROAD OUTER
CIRCULATION OF TROPICAL STORM BERTHA GRABS HOLD OF THE FRONT AND
JERKS IT EASTWARD. A DEEP STREAM OF TROPICAL MOISTURE ALONG THE
COAST IS NOT DIRECTLY ASSOCIATED WITH BERTHA BUT CONTAINS
PRECIPITABLE WATER VALUES IN EXCESS OF TWO INCHES.
WIND PROFILES FROM VIRTUALLY ANY MODEL SHOW A BELT OF FAIRLY STRONG
SOUTHEAST WINDS IN THE LOWEST FEW THOUSAND FEET OF THE ATMOSPHERE
AT THE COAST. AS THESE WINDS COLLIDE AND CONVERGE INTO WEAKER WIND
SPEEDS ON THE COOL SIDE OF THE FRONT...LIFT WILL BE GENERATED. THE
ATMOSPHERE IS CONDITIONALLY UNSTABLE AND WILL EASILY DEVELOP
CONVECTION GIVEN A NUDGE. MY FORECAST POPS ARE IN THE 80-100 PERCENT
RANGE ALONG THE COAST TODAY WITH AREAL RAINFALL FORECASTS 0.75 TO
1.25 INCHES. FARTHER INLAND RAIN CHANCES ARE LOWER...30 TO 60
PERCENT...DUE TO LESS CONVERGENCE ON THE INLAND SIDE OF THE BOUNDARY
AND DRIER AIR IN THE MID LEVELS AS YOU MOVE WESTWARD. HOWEVER WIND
PROFILES SHOW STORM MOTION WILL BE EXCEEDINGLY SLOW SO I CANNOT IN
GOOD CONSCIENCE REMOVE THE FLOOD WATCH ALONG THE I-95 CORRIDOR. FOR
DARLINGTON AND MARLBORO COUNTIES THE THREAT APPEARS SMALL ENOUGH TO
DROP THE WATCH WITH THIS MORNING`S FORECAST PACKAGE.
THERE IS CONSIDERABLE DISAGREEMENT BETWEEN THE 00Z GFS AND NAM
CONCERNING HOW FAR INLAND SIGNIFICANT RAINFALL DEVELOPS TODAY. THE
GFS IS PREFERRED...AND IT HAS THE SUPPORT OF THE ECMWF AND THE LAST
SEVERAL RUNS OF THE HRRR. THE SREF LOOKS MORE LIKE THE 00Z NAM...
UNSURPRISING SINCE THE SREF IS BASED LARGELY ON VARIOUS NAM MEMBERS.
HIGH TEMPS SHOULD AGAIN RUN WELL BELOW NORMALS FOR THIS DATE...
RANGING FROM AROUND 80 AT THE COAST TO 83-85 WELL INLAND...6-10
DEGREES BELOW NORMALS. LOWS TONIGHT SHOULD FALL TO NEAR 70 INLAND TO
THE LOWER 70S AT THE COAST...WITH ANOTHER ROUND OF LOW STRATUS
CLOUDS POSSIBLE IN THE VERY MOIST LOW-LEVEL AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...SMALL CHANCE FOR SOME LINGERING MOISTURE AND
RAIN CHANCES ON TUESDAY MAINLY ALONG THE COAST. SURFACE FLOW WILL
TURN OFFSHORE EARLY FOLLOWED BY LOW LEVEL FLOW SOON THEREAFTER. MID
LEVELS WSWRLY...NOT A NORMALLY MOISTURE-LADEN WIND DIRECTION. THESE
FACTORS SHOULD ALSO LEAD TO MORE SUNSHINE BREAKING OUT THAN THE AREA
HAS SEEN IN QUITE SOME TIME...AND THEREFORE WARMER
TEMPERATURES...PERHAPS EVEN CLIMO HIGHS. MID LEVEL TROUGH AXIS
SWINGS OFFSHORE TUESDAY NIGHT LEADING TO ZONAL AND DOWNSLOPING FLOW.
RAIN CHANCES WHILE NON-ZERO DUE TO A PIEDMONT TROUGH...WILL BE
NEGLIGIBLE. MOST AREAS SHOULD SEE A HIGH ON EITHER SIDE OF 90...A
FEW DEGREES ABOVE INLAND AND PERHAPS A FEW SHY ALONG THE COAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 PM MONDAY...PIEDMONT TROUGH GIVES WAY TO A MORE WEST-TO-EAST
TROUGHINESS AS COLD FRONT APPROACHES THURSDAY. ZONAL MID LEVEL FLOW
KEEPING COLUMN FAIRLY DRY AND MODELS NOT TOO EXITED ABOUT ANYTHING
OTHER THAN ISO SHWR/TSTM. COLD FRONT SLIDES THROUGH FRIDAY WITH
LITTLE LOW LEVEL MOISTURE FLUX AND CONTINUED MID LEVEL WESTERLY DRY
FLOW. GUIDANCE LOOKING A LITTLE WETTER WITH FROPA THOUGH AND SOME
LOW RAIN CHANCES APPEAR WARRANTED. THIS BOUNDARY MAY STALL ALONG THE
COAST FOR THE REMAINDER OF THE PERIOD WHILE WEDGING SETS UP OVER THE
PIEDMONT/COASTAL PLAIN. SATURDAY THROUGH MONDAY MAY THUS OFFER UP
PLENTY OF CLOUDS AND TEMPERED HIGHS AS WELL AS HIGHER THAN NORMAL
RAIN CHANCES.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...SYNOPTICALLY SIMILAR TO YESTERDAY...HOWEVER A BIT LESS
MOISTURE TO WORK WITH. CONVECTION IS MUCH LESS WIDESPREAD AND NOT
NEAR AS FAR INLAND AS YESTERDAY...NEVERTHELESS EXPECTED CONVECTION
TO BE ON THE INCREASE ALONG THE COAST...PEAKING OUT IN INTENSITY
AROUND 15Z WITH ISOLATED THUNDER. MOST OF THE NEAR TERM FORECASTING
BASED ON THE HRRR MODEL. INLAND...LOOKS LIKE LIFR CONDITIONS TO
CONTINUE THROUGH 14Z...WITH A SLOW IMPROVEMENT AFTER THAT BUT LIKELY
REMAINING IFR THROUGH MUCH OF THE FORECAST PERIOD...SINKING BACK
INTO LIFR TONIGHT.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM MONDAY...STALLED FRONTAL BOUNDARY LIES PARALLEL TO
THE ILM CWA COASTLINE...JUST OFFSHORE AND BEYOND 20 NM FROM THE
COAST. AS A RESULT...EXPECTING AN ONSHORE TRAJECTORY WITH THE WIND
FIELD...FROM NE THRU SE AROUND 10 KT. A E-SE GROUND SWELL WILL
BE THE PRIMARY DRIVER OF SIGNIFICANT SEAS ACROSS THE AREA WATERS.
COMBINED WITH LOCALLY PRODUCED WIND-WAVES...SIG. SEAS WILL HOVER
AROUND 4 FT.
PREVIOUS DISCUSSION.............................................
AS OF 645 AM MONDAY...THE FRONT HAS MOVED LITTLE SINCE 3
AM...CROSSING THE COASTLINE NEAR HOLDEN BEACH AND SEPARATING NORTH
WINDS ALONG THE SOUTH CAROLINA BEACHES FROM SOUTH WINDS OVER CAPE
FEAR. THIS BOUNDARY WILL BE THE FOCUS FOR NEW SHOWERS AND TSTMS
TODAY. THIS UPDATE MAINLY ADDRESSES NEAR-TERM WIND DIRECTIONS AND
COVERAGE OF SHOWERS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
A STALLED FRONT SITS JUST OFF THE SOUTH CAROLINA COAST...BUT RUNS
INLAND ACROSS COASTAL SE NORTH CAROLINA. THIS FRONT IS PRODUCING A
VARIETY OF WIND DIRECTIONS...PREVAILING SOUTHEASTERLY ALONG THE
COAST EAST OF OAK ISLAND...AND PREVAILING NORTH TO NORTHEASTERLY
ALONG THE GRAND STRAND. THE BOUNDARY IS EXPECTED TO PUSH INLAND
LATE THIS MORNING WITH EAST TO SOUTHEASTERLY WINDS DEVELOPING
THROUGHOUT THE AREA.
TROPICAL STORM BERTHA WILL NOT DIRECTLY AFFECT THE AREA...BUT WILL
MAKE ITS CLOSEST APPROACH TO THE COASTAL WATERS EARLY THIS EVENING.
BERTHA SHOULD REMAIN SEVERAL HUNDRED MILES OFFSHORE...SENDING SWELLS
INTO THE AREA BUT LITTLE ELSE. NONE OF TODAY`S RAIN OR WIND CAN BE
ATTRIBUTED TO THE STORM. AS BERTHA MOVES NORTH OF OUR LATITUDE
TONIGHT THE FRONT SHOULD BE PULLED BACK OFFSHORE...WITH WIND
DIRECTIONS TENDING TO BACK MORE NORTHEASTERLY WITH TIME.
SEAS AVERAGE 4-5 FEET CURRENTLY...AND MAY BUILD TO A SOLID 5 FEET
TONIGHT AS SWELL FROM BERTHA IMPACTS THE WATERS. SOME MODELS ARE
HINTING AT SOME 6-FOOTERS GETTING INTO THE WATER NEAR CAPE FEAR AND
EAST OF WINYAH BAY.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BERTHA SWELL TO BE RAMPING UP RIGHT AROUND THE
START OF THE PERIOD. BERTHA ACCELERATES BY LATE MONDAY INTO EARLY
TUESDAY WITH ITS CLOSEST APPROACH SOME 300+ MILES OFFSHORE. THE
SWELLS MAY BE SUFFICIENT TO BRING A FEW SMALL CRAFT ADVISORY-WORTHY
6 FT SEAS TO NORTHERN ZONES BUT THERE IS ANOTHER FEW MODEL CYCLES
AND NHC FORECASTS REMAINING TO CLEAR UP ANY UNCERTAINTY. ANOTHER
AREA OF LOW PRESSURE MOVING NE ALONG FRONTAL BOUNDARY LAGS BEHIND
BERTHA...BEING SHALLOWER AND THUS LESS ENTRENCHED IN THE DEEP LAYER
FLOW. THIS LOW WILL KEEP WINDS FAIRLY LIGHT AND GENERALLY
NE...SHIFTING TO NW TUESDAY NIGHT AS IT MOVES BY. ADDITIONAL VEERING
THEN SLATED FOR WEDNESDAY AS WIND SPEEDS DROP ABOUT A CATEGORY.
BACKSWELL DOES NOT APPEAR TO LINGER LONG ACCORDING TO GUIDANCE AS
SEAS QUICKLY SETTLE INTO THE 2 TO 3 FT RANGE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...INLAND PIEDMONT TROUGH TAKES ON A MORE WEST-EAST
ORIENTATION AS THURSDAY PROGRESSES AND GROWS NEARER TO THE COAST.
THIS IS IN RESPONSE TO APPROACH OF A COLD FRONT FROM THE NORTH AND
WEST. THERE MAY BE A SMALL DIRECTION VARIATION AS THIS OCCURS BUT
MAIN EFFECT WILL BE A DECREASE IN SPEED DUE TO THE SLIGHTLY
SLACKENED GRADIENT. COLD FRONT MOVES THROUGH EARLY FRIDAY TURNING
WINDS ONSHORE AND POSSIBLY ADDING 5 KT TO OVERALL SPEEDS. OVERALL
INCREASE IN WAVE HEIGHTS SHOULD BE MINOR BUT THE ONSHORE FLOW
DIRECTION MAY DECREASE THE NEARSHORE/OFFSHORE GRADIENT IN WAVE SIZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR SCZ053>056.
NC...FLOOD WATCH UNTIL 8 PM EDT THIS EVENING FOR NCZ096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...DCH/TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
657 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED TODAY MAINLY ALONG THE COAST. BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM MONDAY...THE 06Z NAM APPEARS TO BE CATCHING ONTO THE
TRENDS ESTABLISHED EARLIER BY THE GFS AND HRRR...AND IS LOWERING
ITS RAINFALL POTENTIAL ALONG AND WEST OF INTERSTATE 95 LATER
TODAY. BASED ON THIS AND RECENTLY OBSERVED RADAR TRENDS
OFFSHORE...I HAVE TRIMMED BACK BOTH RAINFALL PROBABILITY AND
AMOUNT FORECASTS AWAY FROM THE IMMEDIATE COAST TODAY. THIS HAS
GIVEN ME ENOUGH CONFIDENCE TO DROP THE FLOOD WATCH FOR THE REST OF
THE INTERIOR PEE DEE COUNTIES AND ROBESON COUNTY...LEAVING IT IN
EFFECT ONLY FOR THE COASTAL COUNTIES PLUS BLADEN AND COLUMBUS
COUNTIES. FOR BLADEN AND COLUMBUS THE WATCH IS UP MAINLY DUE TO
WATERLOGGED SOILS FROM OVER HALF A FOOT OF RAIN THAT FELL BETWEEN
ELIZABETHTOWN AND WHITEVILLE YESTERDAY.
ALSO...RECENT ASOS OBSERVATIONS REVEAL A GROWING AREA OF 1/4 MILE
VISIBILITIES ACROSS THE INTERSTATE 95 CORRIDOR. A DENSE FOG
ADVISORY HAS BEEN ISSUED HERE THROUGH 9 AM. PREVIOUS DISCUSSION
FROM 300 AM FOLLOWS...
THE RISK OF EXCESSIVE RAINFALL TODAY IS HIGHEST ALONG THE GRAND
STRAND BEACHES NORTHWARD INTO COASTAL SE NORTH CAROLINA. A STALLED
FRONT EXTENDING FROM THE FLORIDA EAST COAST NORTHWARD TO VERY NEAR
WILMINGTON SHOULD MOVE LITTLE THROUGH DAYBREAK. MODELS SHOW THE
BOUNDARY DRIFTING WESTWARD LATE THIS MORNING...BUT THEN RETREATING
BACK OFFSHORE THIS EVENING AS THE INCREASINGLY BROAD OUTER
CIRCULATION OF TROPICAL STORM BERTHA GRABS HOLD OF THE FRONT AND
JERKS IT EASTWARD. A DEEP STREAM OF TROPICAL MOISTURE ALONG THE
COAST IS NOT DIRECTLY ASSOCIATED WITH BERTHA BUT CONTAINS
PRECIPITABLE WATER VALUES IN EXCESS OF TWO INCHES.
WIND PROFILES FROM VIRTUALLY ANY MODEL SHOW A BELT OF FAIRLY STRONG
SOUTHEAST WINDS IN THE LOWEST FEW THOUSAND FEET OF THE ATMOSPHERE
AT THE COAST. AS THESE WINDS COLLIDE AND CONVERGE INTO WEAKER WIND
SPEEDS ON THE COOL SIDE OF THE FRONT...LIFT WILL BE GENERATED. THE
ATMOSPHERE IS CONDITIONALLY UNSTABLE AND WILL EASILY DEVELOP
CONVECTION GIVEN A NUDGE. MY FORECAST POPS ARE IN THE 80-100 PERCENT
RANGE ALONG THE COAST TODAY WITH AREAL RAINFALL FORECASTS 0.75 TO
1.25 INCHES. FARTHER INLAND RAIN CHANCES ARE LOWER...30 TO 60
PERCENT...DUE TO LESS CONVERGENCE ON THE INLAND SIDE OF THE BOUNDARY
AND DRIER AIR IN THE MID LEVELS AS YOU MOVE WESTWARD. HOWEVER WIND
PROFILES SHOW STORM MOTION WILL BE EXCEEDINGLY SLOW SO I CANNOT IN
GOOD CONSCIENCE REMOVE THE FLOOD WATCH ALONG THE I-95 CORRIDOR. FOR
DARLINGTON AND MARLBORO COUNTIES THE THREAT APPEARS SMALL ENOUGH TO
DROP THE WATCH WITH THIS MORNING`S FORECAST PACKAGE.
THERE IS CONSIDERABLE DISAGREEMENT BETWEEN THE 00Z GFS AND NAM
CONCERNING HOW FAR INLAND SIGNIFICANT RAINFALL DEVELOPS TODAY. THE
GFS IS PREFERRED...AND IT HAS THE SUPPORT OF THE ECMWF AND THE LAST
SEVERAL RUNS OF THE HRRR. THE SREF LOOKS MORE LIKE THE 00Z NAM...
UNSURPRISING SINCE THE SREF IS BASED LARGELY ON VARIOUS NAM MEMBERS.
HIGH TEMPS SHOULD AGAIN RUN WELL BELOW NORMALS FOR THIS DATE...
RANGING FROM AROUND 80 AT THE COAST TO 83-85 WELL INLAND...6-10
DEGREES BELOW NORMALS. LOWS TONIGHT SHOULD FALL TO NEAR 70 INLAND TO
THE LOWER 70S AT THE COAST...WITH ANOTHER ROUND OF LOW STRATUS
CLOUDS POSSIBLE IN THE VERY MOIST LOW-LEVEL AIRMASS.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...SMALL CHANCE FOR SOME LINGERING MOISTURE AND
RAIN CHANCES ON TUESDAY MAINLY ALONG THE COAST. SURFACE FLOW WILL
TURN OFFSHORE EARLY FOLLOWED BY LOW LEVEL FLOW SOON THEREAFTER. MID
LEVELS WSWRLY...NOT A NORMALLY MOISTURE-LADEN WIND DIRECTION. THESE
FACTORS SHOULD ALSO LEAD TO MORE SUNSHINE BREAKING OUT THAN THE AREA
HAS SEEN IN QUITE SOME TIME...AND THEREFORE WARMER
TEMPERATURES...PERHAPS EVEN CLIMO HIGHS. MID LEVEL TROUGH AXIS
SWINGS OFFSHORE TUESDAY NIGHT LEADING TO ZONAL AND DOWNSLOPING FLOW.
RAIN CHANCES WHILE NON-ZERO DUE TO A PIEDMONT TROUGH...WILL BE
NEGLIGIBLE. MOST AREAS SHOULD SEE A HIGH ON EITHER SIDE OF 90...A
FEW DEGREES ABOVE INLAND AND PERHAPS A FEW SHY ALONG THE COAST.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 3 PM MONDAY...PIEDMONT TROUGH GIVES WAY TO A MORE WEST-TO-EAST
TROUGHINESS AS COLD FRONT APPROACHES THURSDAY. ZONAL MID LEVEL FLOW
KEEPING COLUMN FAIRLY DRY AND MODELS NOT TOO EXITED ABOUT ANYTHING
OTHER THAN ISO SHWR/TSTM. COLD FRONT SLIDES THROUGH FRIDAY WITH
LITTLE LOW LEVEL MOISTURE FLUX AND CONTINUED MID LEVEL WESTERLY DRY
FLOW. GUIDANCE LOOKING A LITTLE WETTER WITH FROPA THOUGH AND SOME
LOW RAIN CHANCES APPEAR WARRANTED. THIS BOUNDARY MAY STALL ALONG THE
COAST FOR THE REMAINDER OF THE PERIOD WHILE WEDGING SETS UP OVER THE
PIEDMONT/COASTAL PLAIN. SATURDAY THROUGH MONDAY MAY THUS OFFER UP
PLENTY OF CLOUDS AND TEMPERED HIGHS AS WELL AS HIGHER THAN NORMAL
RAIN CHANCES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 12Z...SYNOPTICALLY SIMILAR TO YESTERDAY...HOWEVER A BIT LESS
MOISTURE TO WORK WITH. CONVECTION IS MUCH LESS WIDESPREAD AND NOT
NEAR AS FAR INLAND AS YESTERDAY...NEVERTHELESS EXPECTED CONVECTION
TO BE ON THE INCREASE ALONG THE COAST...PEAKING OUT IN INTENSITY
AROUND 15Z WITH ISOLATED THUNDER. MOST OF THE NEAR TERM FORECASTING
BASED ON THE HRRR MODEL. INLAND...LOOKS LIKE LIFR CONDITIONS TO
CONTINUE THROUGH 14Z...WITH A SLOW IMPROVEMENT AFTER THAT BUT LIKELY
REMAINING IFR THROUGH MUCH OF THE FORECAST PERIOD...SINKING BACK
INTO LIFR TONIGHT.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 645 AM MONDAY...THE FRONT HAS MOVED LITTLE SINCE 3
AM...CROSSING THE COASTLINE NEAR HOLDEN BEACH AND SEPARATING NORTH
WINDS ALONG THE SOUTH CAROLINA BEACHES FROM SOUTH WINDS OVER CAPE
FEAR. THIS BOUNDARY WILL BE THE FOCUS FOR NEW SHOWERS AND TSTMS
TODAY. THIS UPDATE MAINLY ADDRESSES NEAR-TERM WIND DIRECTIONS AND
COVERAGE OF SHOWERS. PREVIOUS DISCUSSION FROM 300 AM FOLLOWS...
A STALLED FRONT SITS JUST OFF THE SOUTH CAROLINA COAST...BUT RUNS
INLAND ACROSS COASTAL SE NORTH CAROLINA. THIS FRONT IS PRODUCING A
VARIETY OF WIND DIRECTIONS...PREVAILING SOUTHEASTERLY ALONG THE
COAST EAST OF OAK ISLAND...AND PREVAILING NORTH TO NORTHEASTERLY
ALONG THE GRAND STRAND. THE BOUNDARY IS EXPECTED TO PUSH INLAND
LATE THIS MORNING WITH EAST TO SOUTHEASTERLY WINDS DEVELOPING
THROUGHOUT THE AREA.
TROPICAL STORM BERTHA WILL NOT DIRECTLY AFFECT THE AREA...BUT WILL
MAKE ITS CLOSEST APPROACH TO THE COASTAL WATERS EARLY THIS EVENING.
BERTHA SHOULD REMAIN SEVERAL HUNDRED MILES OFFSHORE...SENDING SWELLS
INTO THE AREA BUT LITTLE ELSE. NONE OF TODAY`S RAIN OR WIND CAN BE
ATTRIBUTED TO THE STORM. AS BERTHA MOVES NORTH OF OUR LATITUDE
TONIGHT THE FRONT SHOULD BE PULLED BACK OFFSHORE...WITH WIND
DIRECTIONS TENDING TO BACK MORE NORTHEASTERLY WITH TIME.
SEAS AVERAGE 4-5 FEET CURRENTLY...AND MAY BUILD TO A SOLID 5 FEET
TONIGHT AS SWELL FROM BERTHA IMPACTS THE WATERS. SOME MODELS ARE
HINTING AT SOME 6-FOOTERS GETTING INTO THE WATER NEAR CAPE FEAR AND
EAST OF WINYAH BAY.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 3 AM MONDAY...BERTHA SWELL TO BE RAMPING UP RIGHT AROUND THE
START OF THE PERIOD. BERTHA ACCELERATES BY LATE MONDAY INTO EARLY
TUESDAY WITH ITS CLOSEST APPROACH SOME 300+ MILES OFFSHORE. THE
SWELLS MAY BE SUFFICIENT TO BRING A FEW SMALL CRAFT ADVISORY-WORTHY
6 FT SEAS TO NORTHERN ZONES BUT THERE IS ANOTHER FEW MODEL CYCLES
AND NHC FORECASTS REMAINING TO CLEAR UP ANY UNCERTAINTY. ANOTHER
AREA OF LOW PRESSURE MOVING NE ALONG FRONTAL BOUNDARY LAGS BEHIND
BERTHA...BEING SHALLOWER AND THUS LESS ENTRENCHED IN THE DEEP LAYER
FLOW. THIS LOW WILL KEEP WINDS FAIRLY LIGHT AND GENERALLY
NE...SHIFTING TO NW TUESDAY NIGHT AS IT MOVES BY. ADDITIONAL VEERING
THEN SLATED FOR WEDNESDAY AS WIND SPEEDS DROP ABOUT A CATEGORY.
BACKSWELL DOES NOT APPEAR TO LINGER LONG ACCORDING TO GUIDANCE AS
SEAS QUICKLY SETTLE INTO THE 2 TO 3 FT RANGE.
LONG TERM /THURSDAY THROUGH FRIDAY/...
AS OF 3 PM MONDAY...INLAND PIEDMONT TROUGH TAKES ON A MORE WEST-EAST
ORIENTATION AS THURSDAY PROGRESSES AND GROWS NEARER TO THE COAST.
THIS IS IN RESPONSE TO APPROACH OF A COLD FRONT FROM THE NORTH AND
WEST. THERE MAY BE A SMALL DIRECTION VARIATION AS THIS OCCURS BUT
MAIN EFFECT WILL BE A DECREASE IN SPEED DUE TO THE SLIGHTLY
SLACKENED GRADIENT. COLD FRONT MOVES THROUGH EARLY FRIDAY TURNING
WINDS ONSHORE AND POSSIBLY ADDING 5 KT TO OVERALL SPEEDS. OVERALL
INCREASE IN WAVE HEIGHTS SHOULD BE MINOR BUT THE ONSHORE FLOW
DIRECTION MAY DECREASE THE NEARSHORE/OFFSHORE GRADIENT IN WAVE SIZE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR SCZ017-023-
024-032-033.
FLOOD WATCH THROUGH THIS EVENING FOR SCZ053>056.
NC...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR NCZ087.
FLOOD WATCH THROUGH THIS EVENING FOR NCZ096-099-105>110.
MARINE...NONE.
&&
$$
SYNOPSIS...MBB
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
126 AM EDT MON AUG 4 2014
.SYNOPSIS...
A COASTAL FRONT AND ABUNDANCE OF TROPICAL MOISTURE WILL KEEP THE
WEATHER UNSETTLED THROUGH MONDAY. TROPICAL STORM BERTHA WILL REMAIN
MUCH TOO FAR OFFSHORE FOR ANY DIRECT IMPACTS THROUGH TUESDAY...
ALTHOUGH THE RIP CURRENT RISK WILL LIKELY INCREASE. MORE TYPICAL
SUMMER WEATHER RETURNS WEDNESDAY AND THURSDAY AS DRYING AND WARMING
TAKE PLACE. COOLER WEATHER IS THEN SLATED FOR THE LATE WEEK PERIOD
BEHIND A COLD FRONT.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 130 AM MONDAY...RADAR AND LATEST HRRR MODEL RUNS WERE THE
BASIS FOR THE UPDATE EARLY THIS MORNING. THE I-95 CORRIDOR SHOULD
REMAIN DRY THROUGH DAYBREAK WITH THE BEST PRECIPITATION FOCUSED DOWN
AT THE COAST...PARTICULARLY ACROSS THE CAPE FEAR/WILMINGTON AREA
WHERE AREAL AVERAGES OF 1/2 INCH OF RAIN IS EXPECTED BY DAYBREAK. A
WEAK LOW OBSERVED ON RADAR ANIMATIONS MADE LANDFALL NEAR HOLDEN
BEACH A LITTLE EARLIER WITH IMPACTS ON WIND DIRECTIONS NOTED. WINDS
ALONG THE SC COAST SHOULD VEER MORE EASTERLY/SOUTHEASTERLY WITH
TIME. PREVIOUS DISCUSSION FROM 1100 PM FOLLOWS...
RADAR ANIMATIONS SHOW AN INTERESTING BUT WEAK LOW-LEVEL CIRCULATION
CURLING ONSHORE INTO THE BRUNSWICK COAST LATE THIS EVENING. IN
LONG-LOOPS OF SATELLITE ONE CAN TRACE BACK THIS SMALL FEATURE TO THE
MORE OPEN SEA BEFORE IT TRAVELED UNDER CLOUDS CLOSER TO THE COAST
HERE.
THE LATEST SPC MESOANALYSIS PLOTS CONFIRM DIURNAL INSTABILITY IS
INCREASING OVER THE COASTAL WATERS AS IS LOW-LEVEL CONVERGENCE
NEAR THE COAST AS LAND WINDS DECOUPLE. OF NOTE IS A SHARPENING
INVERTED COASTAL TROUGH OFFSHORE...AS LOW PRESSURE AT THE SURFACE
OFF OF JACKSONVILLE FL DRIFTS NORTH. THIS FEATURE HAS DEEPENED A
BIT OVER THE LAST SEVERAL HOURS. AS A RESULT ONE CHANGE IN MIND IS
TO INCREASE SE WINDS ALONG OUR SC COAST OVERNIGHT...AND UPPING THE
POP VALUES IN THIS AREA AS CONVERGENCE AND THE PRESSURE GRADIENT
BOTH INCREASE. AM EXPECTING A NORTHWARD EXPANSION OF SHOWERS AND
TSTMS OFFSHORE TO ENCROACH AND IMPACT OUR COAST LATE TONIGHT AND
IF PERSISTENCE HAS A SAY...MUCH OF THE COAST WILL SEE RAIN AND
RUMBLES INTO DAYBREAK.
PWAT VALUES OF 2.1" OFFSHORE TO 2` ALONG THE COAST TO 1.6" OVER
OUR FAR INLAND LOCALS THIS EVENING. A BELT OF STRONGER MID-LVL
FLOW CAN BE SEEN IN VAPOR ANIMATIONS AHEAD OF THE UPPER TROUGH TO
OUR WEST. A FEW IMPULSES ARE ROUNDING THE BASE KEEPING THE WEATHER
UNSETTLED OVER PORTIONS OF AL/GA...AND THIS MAY BE A PLAYER FOR
OUR INLAND ZONES LATER AS WELL. A FLOOD WATCH REMAINS POSTED FOR
ALL OUR ZONES THROUGH MUCH OF MONDAY.
TEMPERATURES ACROSS INLAND LOCATIONS MAY LEVEL OFF FOR THE MOST
PART OVERNIGHT...PERHAPS BUMPING UP A DEGREE OR TWO ALONG THE
COAST LATE AS THE PRESSURE GRADIENT TIGHTENS...PARTICULARLY THE SC
COAST. GUSTS TO 20 MPH ALONG THE GEORGETOWN AND HORRY COAST SHOULD
NOT BE A SHOCK BY DAYBREAK. ANY TSTMS IN THE AREA WILL INCREASE THE
GUSTS FACTOR AS WELL.
&&
.SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...DEEP MOISTURE PLUME WILL REMAIN IN THE VICINITY
OF THE COAST THROUGH MONDAY. THUS VERY LITTLE CHANGE EXPECTED WITH
THE NORTHWARD STREAM OF TROPICAL MOISTURE GIVEN THE POSITIONING OF
THE MID LEVEL TROUGH AXIS WEST OF THE FORECAST AREA AND A
SUBTROPICAL RIDGE CENTERED OVER BERMUDA. IMPULSES WITHIN THE DEEPER
SOUTHERLY FLOW WILL PROVIDE THE SPARK FOR ADDITIONAL CONVECTION
DURING MONDAY...AND COUPLED WITH THE EXPECTATIONS FOR HEAVY RAIN
AGAIN DURING THE OVERNIGHT WE HAVE EXTENDED THE FLOOD WATCH THROUGH
8 PM EDT MONDAY.
THE PRECIPITABLE WATER WILL BE A LITTLE LOWER BY TUESDAY...BUT NO
SIGNIFICANT DROP OFF IN PRECIPITABLE WATER IS EXPECTED UNTIL TUESDAY
NIGHT AS DEEPER WESTERLY FLOW DEVELOPS THROUGH A LARGE PART OF THE
COLUMN. BY THIS TIME...BERTHA WILL HAVE TRACKED FAR OFF THE CAROLINA
COAST AND RACED FAR OFF TO THE NORTHEAST BY TUESDAY NIGHT. SWELLS
WILL INCREASE FROM BERTHA BY TUESDAY AND PERSIST INTO WEDNESDAY
LIKELY LEADING TO A PERIOD OF ENHANCED RIP CURRENT ACTIVITY.
CLOUD COVER DURING MONDAY SUPPORTS UNDER-CUTTING MAV MAX
TEMPERATURES BY A COUPLE CATEGORIES. EACH NIGHT MAV MINS LOOK
REASONABLE WITH READINGS AROUND 70 INLAND TO THE LOWER 70S AT THE
IMMEDIATE COAST. MAV HIGHS ON TUESDAY MAY ALSO BE OVERDONE DEPENDING
ON THE CLOUD COVER...AND FOR NOW ONLY CUT THE GUIDANCE BY A COUPLE
DEGREES.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 3 PM SUNDAY...FAIRLY QUIET CONDITIONS WILL KICKOFF THE LONG
TERM PERIOD AS WEAK SFC HIGH PRESSURE REIGNS OVER THE AREA WITH
PURELY ZONAL FLOW ALOFT. THE FOCUS WILL BE ON THE PROGRESSION OF A
EASTWARD PROPAGATING TROUGH AS IT TRANSITIONS AND STRENGTHENS FROM
THE GREAT LAKES REGION INTO THE NORTHEAST WEDNESDAY INTO THURSDAY.
RAIN/THUNDERSTORM CHANCES WILL BE FAIRLY LOW BOTH DAYS...ESPECIALLY
GIVEN THE LACK OF AVAILABLE MOISTURE THROUGH THE ATMOSPHERIC
COLUMN...THOUGH COULD NOT ENTIRELY RULE OUT AN ISOLATED POP-UP AS A
RESULT OF THE AFTERNOON SEA BREEZE OR PIEDMONT TROUGH. LATEST
GUIDANCE SEEMS TO BE IN PRETTY GOOD AGREEMENT WITH THE SOUTHEASTWARD
PROGRESSION OF A COLD FRONT...INITIATED FROM EASTWARD MOVING TROUGH
TO OUR NORTH. ANTICIPATE THIS FEATURE TO PUSH THROUGH THE FORECAST
GIVEN THE AFOREMENTIONED SOMEWHAT LACK OF MOISTURE...NOT
ANTICIPATING MUCH IN THE WAY OF PRE-FRONTAL DEVELOPMENT...BUT AS THE
FRONTAL BOUNDARY STALLS JUST OFFSHORE SOUTH OF OUR AREA ON FRIDAY
AND THEN LIFT NORTHWARD OVERNIGHT INTO SUNDAY WITH THE DEVELOPMENT
OF A COASTAL LOW...WILL SEE AN SLIGHT INCREASE OF ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND.
HIGH TEMPERATURES WEDNESDAY INTO THURSDAY WILL BE AROUND 90
DEGREES...DROPPING INTO THE UPPER 80S FRIDAY WITH THE PASSAGE OF THE
COLD FRONT...CONTINUING THROUGH THE END OF THE PERIOD. OVERNIGHT
LOWS WILL BE IN THE UPPER 60S/LOW 70S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 06Z...APPROACHING SHORT WAVE IMPULSES WILL PRODUCE WIDESPREAD
SHOWERS AT THE COASTAL TERMINALS THROUGH AT LEAST THIS
MORNING...PERHAPS INTO THE AFTERNOON AS WELL. ISOLATED THUNDER IS
POSSIBLE EARLY THIS MORNING. SHOWERS MAY SPREAD TO THE KLBT TERMINAL
AFTER DAYBREAK...WITH CONSIDERABLE MODEL UNCERTAINTY ON WHETHER KFLO
GETS PRECIP OF IT REMAINS JUST EAST. CONVECTION ASSOCIATED WITH A
COASTAL LOW WILL SPREAD NORTH AFFECTING KCRE/KMYR INITIALLY...THEN
SPREADING NORTH ALONG THE COAST. SOME LETUP IN PRECIPITATION IS
POSSIBLE IN MID AFTERNOON AT THE COASTAL TERMINALS.
IFR/LIFR SHOULD DEVELOP SHORTLY AT KFLO/KLBT. TEMPO IFR IN HEAVIER
SHOWERS AT THE COASTAL TERMINALS. MVFR/TEMPO IFR AFTER 15Z.
EXTENDED OUTLOOK...SHRA/TSRA/IFR/LIFR LIKELY THROUGH MON NIGHT WITH
CONDITIONS IMPROVING TO WIDELY SCATTERED SHOWERS/TEMPO MVFR TUES.
VFR WED. CHANCE OF SHRA/TSRA/TEMPO MVFR THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 130 AM MONDAY...WINDS HAVE A DISTINCT CYCLONIC SPIN AROUND A
WEAK LOW THAT MOVED ONSHORE IN CENTRAL BRUNSWICK COUNTY NEAR HOLDEN
BEACH IN THE PAST HOUR. CHANGES TO THE FORECAST HAVE ATTEMPTED TO
CAPTURE THE CURRENT WIND DIRECTIONS WITH RENEWED VEERING WITH TIME
ALONG THE SC COAST AS THE NORTHEASTERLY WINDS ASSOCIATED WITH THE
WEAK LOW FADE. SEAS RANGE FROM 3-4 FEET ON LATEST BUOY OBSERVATIONS.
PREVIOUS DISCUSSION FROM 1100 PM FOLLOWS...
GRADIENT IS STARTING TO TIGHTEN AND WILL HOIST A SCEC FOR THE SC
WATERS FOR THE LIKELIHOOD OF 20 KT WINDS AND 4-5 FT SEAS LATE
TONIGHT. SOUTHEAST WINDS WILL CONTINUE THROUGH THE PERIOD WITH A
SLIGHT INCREASE IN SPEEDS EXPECTED TONIGHT AHEAD OF WEAK LOW LIFTING
NORTH FROM THE BAHAMAS. SPEEDS SHOULD REMAIN WITHIN THE 10 TO 20 KT
RANGE THROUGH THE END OF THE PERIOD. SEAS WILL RUN 3 TO 5 FT. LOW
AMPLITUDE SWELL WAVES FROM BERTHA ARE ANTICIPATED SOMETIME MONDAY.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 PM SUNDAY...E-SE FLOW WILL PREVAIL MONDAY...THEN LIGHT
NORTHERLY FLOW TUESDAY MORNING PRIOR TO BACKING TO A LIGHT WESTERLY
DIRECTION. EVEN WITH LIGHT WIND SEAS WILL BE ON THE INCREASE MONDAY
NIGHT INTO TUESDAY AS SWELLS FROM BERTHA MOVE ACROSS THE WATERS. THE
SEAS MAY RESULT IN MARGINAL SMALL CRAFT CONDITIONS...BUT WILL CREATE
SOME HAZARDS AROUND INLET ENTRANCES DURING TIMES OF FALLING TIDE.
WINDS/SEAS ALSO LOCALLY HIGHER IN ANY SHOWERS/TSTMS THROUGH THE
PERIOD.
LONG TERM /WEDNESDAY THROUGH FRIDAY/...
AS OF 3 PM SUNDAY...WEAK HIGH PRESSURE ON WEDNESDAY WILL BE REPLACED
BY AN APPROACHING COLD FRONT THURSDAY NIGHT INTO FRIDAY FROM THE
NORTHWEST. WEST-SOUTHWESTERLY FLOW WILL PERSIST THROUGH THE
PERIOD...WITH SUSTAINED WINDS INCREASING UP TO 15 KTS WEDNESDAY
NIGHT INTO THURSDAY...DECREASING TO AROUND 10 KTS BY FRIDAY MORNING
BEFORE SHIFTING AND BECOMING 5 TO 10 KTS WITH THE FRONT. SEAS WILL
BE 2 TO 3 FT OVERALL...WITH 4 FTERS POSSIBLE ESPECIALLY IN THE OUTER
WATERS OVERNIGHT INTO THURSDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FLOOD WATCH THROUGH MONDAY EVENING FOR SCZ017-023-024-032-033-
039-053>056.
NC...FLOOD WATCH THROUGH MONDAY EVENING FOR NCZ087-096-099-105>110.
MARINE...NONE.
&&
$$
NEAR TERM...MJC/TRA
SHORT TERM...SRP
LONG TERM...SGL
AVIATION...MRR/TRA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1259 PM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1259 PM CDT MON AUG 4 2014
UPDATED THE FORECAST TO LOWER FORECAST HIGHS ACROSS SOUTH CENTRAL
NORTH DAKOTA THIS AFTERNOON. A COMPLEX OF SHOWERS WITH EMBEDDED
THUNDERSTORMS IS SLOWLY MOVING SOUTHEAST...AND SHOULD BE OUT OF
THE AREA BY LATE AFTERNOON.
OTHERWISE...THE REMAINING FORECAST ELEMENTS ARE IN GOOD SHAPE. THE
UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 944 AM CDT MON AUG 4 2014
ONGOING CONVECTION SOUTHWEST OF THE MISSOURI RIVER IS ASSOCIATED
WITH AN SUBTLE UPPER LEVEL SHORTWAVE MOVING ACROSS THE STATE THIS
MORNING. RADAR DETECTED A STORM THAT WAS CAPABLE OF PRODUCING
SEVERE HAIL OVER EASTERN GRANT COUNTY ABOUT AN HOUR AGO.
HOWEVER...NO SEVERE REPORTS WERE RECEIVED. THESE STORMS ARE NOW
MOVING INTO CORSON COUNTY SOUTH DAKOTA AS OF THE TIME OF THIS
WRITING.
THE LATEST HRRR MAINTAINS CONVECTION OVER MOST OF SOUTHWESTERN AND
SOUTH CENTRAL NORTH DAKOTA THROUGH THE LATE MORNING HOURS...WITH
DECREASING THUNDERSTORM CHANCES DEVELOPING FROM WEST TO EAST THIS
AFTERNOON AS SUBSIDENCE DEVELOPS ON THE BACK SIDE OF THE
SHORTWAVE. KEPT THIS TREND GOING IN THE CURRENT FORECAST AND
UPDATED TO INCREASE MORNING POPS. ALSO REMOVED MORNING FOG WORDING
FROM THE ZONES. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1259 PM CDT MON AUG 4 2014
VFR CONDITIONS ARE EXPECTED TO PERSIST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THROUGH THE TAF PERIOD. A COMPLEX OF SHOWERS WILL
CONTINUE TO PUSH SOUTH OF KBIS THIS AFTERNOON. OTHERWISE...THE
NEXT CHANCE OF CONVECTION IS EXPECTED TO DEVELOP OVER SOUTHWESTERN
NORTH DAKOTA (KDIK) AFTER SUNRISE TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...AYD
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
945 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 944 AM CDT MON AUG 4 2014
ONGOING CONVECTION SOUTHWEST OF THE MISSOURI RIVER IS ASSOCIATED
WITH AN SUBTLE UPPER LEVEL SHORTWAVE MOVING ACROSS THE STATE THIS
MORNING. RADAR DETECTED A STORM THAT WAS CAPABLE OF PRODUCING
SEVERE HAIL OVER EASTERN GRANT COUNTY ABOUT AN HOUR AGO.
HOWEVER...NO SEVERE REPORTS WERE RECEIVED. THESE STORMS ARE NOW
MOVING INTO CORSON COUNTY SOUTH DAKOTA AS OF THE TIME OF THIS
WRITING.
THE LATEST HRRR MAINTAINS CONVECTION OVER MOST OF SOUTHWESTERN AND
SOUTH CENTRAL NORTH DAKOTA THROUGH THE LATE MORNING HOURS...WITH
DECREASING THUNDERSTORM CHANCES DEVELOPING FROM WEST TO EAST THIS
AFTERNOON AS SUBSIDENCE DEVELOPS ON THE BACK SIDE OF THE
SHORTWAVE. KEPT THIS TREND GOING IN THE CURRENT FORECAST AND
UPDATED TO INCREASE MORNING POPS. ALSO REMOVED MORNING FOG WORDING
FROM THE ZONES. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM CDT MON AUG 4 2014
LIFR CONDITIONS IN STRATUS WILL CONTINUE AT KDIK THROUGH AT LEAST
15 UTC...SLOWING IMPROVING THEREAFTER. MVFR/IFR FOG WILL CONTINUE
AT KMOT THROUGH 14 UTC THIS MORNING. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL IMPACT KDIK AND KBIS THIS MORNING AND INTO THE
EARLY AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE AT KDIK AND
KBIS TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
702 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 701 AM CDT MON AUG 4 2014
THE 00 UTC WRF-NMM AND ARW...06 UTC NAM AND 10 UTC HRRR HAVE A
GOOD HANDLE ON THE ONGOING CONVECTION ACROSS SOUTHWEST AND SOUTH
CENTRAL NORTH DAKOTA...AND WILL FOLLOW THEIR SOLUTIONS FOR POPS
THE REMAINDER OF THE DAY. OVERALL...CONVECTIVE COVERAGE WILL BE
GREATEST THIS MORNING...BECOMING ISOLATED TO SCATTERED THROUGH THE
AFTERNOON AS UPPER LEVEL FORCING BECOMES MORE NEBULOUS. GIVEN
WEAK INSTABILITY...SEVERE WEATHER IS NOT EXPECTED.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CDT MON AUG 4 2014
THE MAIN FORECAST PROBLEM WILL BE THE CONVECTIVE POTENTIAL
THROUGH THE PERIOD.
CURRENTLY...SURFACE HIGH PRESSURE EXTENDED FROM WESTERN ONTARIO TO
EASTERN NORTH DAKOTA WHILE LOW PRESSURE CONTINUED TO DEEPEN OVER
WYOMING AND COLORADO. AT UPPER LEVELS...SHORTWAVES CONTINUE TO MOVE
THROUGH THE UPPER FLOW FROM SOUTHWESTERN CANADA ACROSS THE ROCKIES
AND INTO THE FRONT RANGE AND NORTHERN PLAINS STATES. ONE RELATIVELY
STRONG SHORTWAVE ENERGY VORT MAX WAS OVER EASTERN MONTANA...LIKELY
ASSOCIATED WITH A LINE OF THUNDERSTORMS BETWEEN GLASGOW AND
BILLINGS. THIS AREA OF CONVECTION HAS HELD TOGETHER AND CONTINUES TO
MOVE SOUTHEASTWARD. ANOTHER AREA OF CONVECTION BEGAN IN WESTERN
SOUTH DAKOTA LATE SUNDAY EVENING/EARLY MONDAY MORNING. A LOW LEVEL
JET FROM WESTERN AND CENTRAL SOUTH DAKOTA...TO SOUTH CENTRAL AND
WESTERN NORTH DAKOTA...TO EASTERN MONTANA IS LIKELY ASSOCIATED WITH
THE CONVECTION IN SOUTH DAKOTA. THERE WERE A COUPLE OF SMALL CELLS
THAT DEVELOPED OVER GOLDEN VALLEY AND SLOPE COUNTIES IN THE PAST
HOUR OR TWO.
THE COMBINATION OF THE APPROACHING UPPER LEVEL VORT MAX IMPULSE IN
EASTERN MONTANA...AND THE DEVELOPING LOW LEVEL JET OVER THE WESTERN
DAKOTAS AND EASTERN MONTANA...SHOULD AID IN DEVELOPMENT OF ELEVATED
SHOWERS AND THUNDERSTORMS BEFORE SUNRISE. THE MODELS INDICATE THE
UPPER LEVEL IMPULSE SPREADING SOUTHEAST ACROSS WESTERN AND CENTRAL
NORTH DAKOTA THIS MORNING...AND WEAKENING THIS AFTERNOON AS IT MOVES
SOUTHEAST TOWARDS EASTERN SOUTH DAKOTA. HAVE CHANCES OF
THUNDERSTORMS EARLY THIS MORNING WITH SCATTERED COVERAGE
EXPECTED...THEN BECOMING MORE ISOLATED IN NATURE BY AFTERNOON.
TONIGHT ANOTHER MORE VIGOROUS SET OF UPPER LEVEL IMPULSES EMANATING
FROM THE CENTRAL US ROCKIES IS FORECAST TO MOVE NORTHEASTWARD
ACROSS MONTANA AND WYOMING THIS AFTERNOON...REACHING SOUTHWESTERN
NORTH DAKOTA LATER THIS EVENING AND SPREADING TOWARDS CENTRAL NORTH
DAKOTA LATE MONDAY NIGHT. THE BEST CAPE/SHEAR COMBINATION TONIGHT IS
OVER MONTANA...WITH THE SURFACE HIGH FROM WESTERN ONTARIO NUDGING
FURTHER INTO EASTERN NORTH DAKOTA. THUS NOT EXPECTING SEVERE STORMS
TO REACH WESTERN NORTH DAKOTA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CDT MON AUG 4 2014
THUNDERSTORM AND RAINFALL POTENTIAL WEST AND SOUTH CENTRAL TUESDAY
AND WEDNESDAY WILL HIGHLIGHT THE EXTENDED.
A CONSENSUS OF THE 00 UTC GLOBAL AND HIGH RESOLUTION GUIDANCE
PROPAGATES THE UPPER LEVEL LOW ACROSS SOUTHWEST ALBERTA TODAY INTO
EASTERN MONTANA AND WESTERN NORTH DAKOTA LATE TUESDAY AND INTO
WEDNESDAY...WITH SURFACE HIGH PRESSURE ACROSS NORTHEAST NORTH
DAKOTA INTO THE UPPER MISSISSIPPI VALLEY. SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP TUESDAY AFTERNOON ACROSS
EASTERN MONTANA...PROPAGATING INTO WESTERN AND SOUTH CENTRAL NORTH
DAKOTA BY LATE AFTERNOON/EARLY EVENING. RE-DEVELOPMENT IS FORECAST
FOR THESE AREAS AGAIN WEDNESDAY ALONG THE WESTERN PERIPHERY OF THE
SURFACE HIGH. OVERALL INSTABILITY IS WEAK...WITH LITTLE CHANCE FOR
SEVERE STORMS...IN LINE WITH THE SPC DAY 2 AND 3 OUTLOOKS. LOCALLY
HEAVY RAINFALL IS A POSSIBILITY WITH PWATS NEAR 1.50 INCHES AND
SLOW STORM MOTIONS WITH WEAK LOW TO MID LEVEL FLOW.
THEREAFTER...FOR WEDNESDAY THROUGH THE WEEKEND...NEAR ZONAL FLOW IS
FORECAST...FAVORING NEAR NORMAL TEMPERATURES AND SPORADIC
THUNDERSTORM CHANCES WITH WEAK IMPULSES EMBEDDED IN THE SOUTHERN
PERIPHERY OF THE UPPER JET.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 701 AM CDT MON AUG 4 2014
LIFR CONDITIONS IN STRATUS WILL CONTINUE AT KDIK THROUGH AT LEAST
15 UTC...SLOWING IMPROVING THEREAFTER. MVFR/IFR FOG WILL CONTINUE
AT KMOT THROUGH 14 UTC THIS MORNING. SCATTERED TO NUMEROUS
THUNDERSTORMS WILL IMPACT KDIK AND KBIS THIS MORNING AND INTO THE
EARLY AFTERNOON. ADDITIONAL THUNDERSTORMS ARE POSSIBLE AT KDIK AND
KBIS TONIGHT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MEDFORD OR
259 PM PDT MON AUG 4 2014
.DISCUSSION...WATER VAPOR IMAGERY IS SHOWING A LARGE PLUME OF
MONSOONAL MOISTURE LIFTING NORTHWARD THROUGH NORTHERN CALIFORNIA
AND INTO OREGON THIS AFTERNOON. THIN CIRRUS AND WILDFIRE SMOKE HAS
BEEN INHIBITING SURFACE HEATING A BIT EARLY THIS AFTERNOON, BUT
RADAR IMAGERY IS NOW SHOWING SOME SHOWER/THUNDERSTORM DEVELOPMENT
IN LAKE AND MODOC COUNTIES. THIS ACTIVITY WILL CONTINUE TO ENHANCE
THIS AFTERNOON AND MOVE TO THE WEST SOUTHWEST THROUGH THIS
EVENING. INSTABILITY WILL ALSO CONTINUE TO INCREASE FROM SISKIYOU
COUNTY NORTHWARD UP ALONG THE CASCADES AND EXPECT THUNDERSTORMS TO
DEVELOP THERE TOO AS THE CAP ERODES. THERE IS STILL A SIGNIFICANT
THREAT FOR A LOT OF LIGHTNING WITH THESE STORMS AND AS A RESULT,
WE ARE MAINTAINING THE RED FLAG WARNING THROUGH THE FIRST PART OF
TONIGHT (2AM PDT). WITH THE UPPER LOW NEAR TAHOE, THE FLOW ALOFT IS
FAIRLY LIGHT OUT OF THE NORTHEAST, SO STORM MOTIONS WILL BE ON THE
SLOW SIDE. PRECIPITABLE WATER VALUES OVER A BROAD AREA ARE
1.00-1.25 INCHES, SO STORMS THAT DO DEVELOP WILL PRODUCE RAINFALL.
DUE TO SLOW STORM MOTIONS, SOME OF THE STRONGER STORMS WILL HAVE
THE CAPABILITY OF PRODUCING VERY HEAVY RAINFALL. THIS MAY PRESENT
A FLASH FLOOD THREAT...ESPECIALLY TO AREAS THAT HAVE PREVIOUSLY
BURNED. WITH THE SOUTHWESTWARD MOVEMENT, SOME STORMS THAT FORM
OVER THE CASCADES AND THE EAST SIDE THIS AFTERNOON MAY DRIFT OVER
THE ROGUE VALLEY THIS EVENING. LATEST HRRR GUIDANCE IS INDICATING
THAT MANY OF THE STORMS THAT GET GOING THIS AFTERNOON AND EVENING
WILL MORPH INTO AN AREA OF SHOWERS WITH EMBEDDED THUNDER LATE
TONIGHT INTO TUESDAY MORNING AS IT CONTINUES TO SAG SLOWLY
SOUTHWESTWARD. THIS SEEMS REASONABLE AS WE LOSE THE DAYTIME
INSTABILITY AND THE AXIS OF DEFORMATION STARTS TO SHIFT SOUTHWARD.
WE EXPECT THE BEST THUNDERSTORM PROBABILITIES TO SHIFT
SOUTHEASTWARD TUESDAY AFTERNOON AND EVENING AS THE UPPER LOW FILLS
AND THE DEFORMATION AXIS CONTINUES SOUTHEASTWARD...BUT STILL
EXPECT SOME DEVELOPMENT IN NORTHERN CALIFORNIA AND PORTIONS OF
SOUTHERN KLAMATH AND LAKE COUNTIES. WE HAVE DECIDED TO WAIT TO SEE
HOW MUCH LIGHTNING AND RAINFALL WE GET WITH TODAY`S STORMS AND
HAVE PUSHED BACK THE START TIME OF TUESDAY`S FIRE WEATHER WATCH TO
18Z. MUCH WILL DEPEND ON HOW MUCH RESIDUAL CLOUD COVER REMAINS IN
THE MORNING AND IF WE CAN GET SOME SUN TO DESTABILIZE THE
ATMOSPHERE FOR THE AFTERNOON. WEST TO NORTHWEST FLOW ALOFT WILL
BEGIN TO MOVE INTO NORTHWESTERN SECTIONS OF THE CWA TUESDAY, SO
WE`RE NOT EXPECTING ANY DEVELOPMENT WEST OF THE CASCADES.
BY WEDNESDAY, THERE IS STILL A SLIGHT CHANCE OF THUNDERSTORMS
ACROSS SOUTH AND EAST SECTIONS OF THE CWA, BUT THE REST OF THE
AREA WILL BE DRY AS NORTHWESTERLY FLOW ALOFT TAKES OVER. WE SHOULD
CATCH A BREAK THURSDAY WITH ACTIVITY STAYING MOSTLY SOUTH WITH
NEAREST ISOLATED ACTIVITY POPPING UP ALONG THE SIERRAS/LASSEN
AREA SOUTH OF THE CWA.
FRIDAY THROUGH THE WEEKEND...AN UPPER TROUGH WILL DEVELOP NEAR THE
NORTHWEST CALIFORNIA COAST AND THIS MAY DEVELOP INTO ANOTHER UPPER
LEVEL LOW. THIS WILL INCREASE THUNDERSTORM CHANCES AGAIN OVER THE
MOUNTAINS AND FROM THE CASCADES EASTWARD. SPILDE
&&
.AVIATION...FOR THE 04/18Z TAFS...SMOKE WILL CONTINUE TO AFFECT
VISIBILITY OVER PORTIONS OF SOUTHWEST OREGON AND NORTHERN
CALIFORNIA TODAY. HOWEVER, THE TERMINALS ARE NOT HAVING ANY
RESTRICTIONS. IFR CIGS IN STRATUS WILL IMPACT THE COAST (INCLUDING
KOTH) ALTHOUGH THE STRATUS WILL DISSIPATE TO NEAR THE BEACHES LATE
THIS AFTERNOON. SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO DEVELOP INLAND THIS AFTERNOON MAINLY NEAR AND EAST OF THE
CASCADES AND ACROSS NORTHERN CALIFORNIA. CIGS AND VIS WILL BE VFR
OUTSIDE STORMS, BUT STORMS MAY BRING HEAVY RAIN WITH POSSIBLE MVFR
OR EVEN IFR CIGS AND VIS THROUGH THE NIGHT.
&&
.MARINE...UPDATED 300 PM PDT 4 AUG 2014...
A THERMAL TROUGH PATTERN ALONG THE COAST WITH HIGH PRESSURE OFFSHORE
WILL MAINTAIN GUSTY NORTH WINDS AND ELEVATED SEAS THROUGH THE
WEEK...MAINLY ACROSS THE WATERS SOUTH OF CAPE BLANCO. VERY STEEP
SEAS WILL BE CONFINED TO AREAS BEYOND 10NM FROM SHORE AND SOUTH OF
GOLD BEACH. THE THERMAL TROUGH PATTERN WILL STRENGTHEN WEDNESDAY INTO
FRIDAY...SO INCREASING WINDS AND SEAS ARE EXPECTED. JBL
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR ORZ617-620>625.
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR ORZ621-623>625.
CA...RED FLAG WARNING UNTIL 2 AM PDT TUESDAY FOR CAZ280>282-284-285.
FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
FOR CAZ280>282-284-285.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR WINDS UNTIL 11 PM PDT
THURSDAY FOR PZZ356-376.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 11 PM PDT THURSDAY
FOR PZZ356-376.
HAZARDOUS SEAS WARNING UNTIL 11 PM PDT THIS EVENING FOR PZZ376.
$$
MAS/CC/JBL
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1052 PM EDT TUE AUG 5 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS EVENING. A
STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH
WEDNESDAY...FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT
WILL LAST INTO THIS COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
1048 PM UPDATE...
NOT A LOT OF CHANGE.
COULD TRACK THE GUST FRONT TO ALMOST MDT...JUST BEFORE 845 PM.
ANYWAY...MAIN ISSUE WILL BE LOW CLDS AND PATCHY FOG OVERNIGHT.
FEW MORE SHOWERS ACROSS THE SE UNTIL 1 AM.
DID CUT POPS BACK SOME...ACTIVITY OVER OH WILL LIKELY BE MORE
OF AN ISSUE FOR SW PA THAN NW PA LATE.
EARLIER DISCUSSION BELOW.
BEEN TRACKING A LONG DURATION...FAST MOVING GUST FRONT ACROSS
THE AREA. WIND GUST TO AROUND 40 MPH...AND A TEMP DROP OF 10 TO 15
DEGREES. NORMALLY SEE THESE EARLY IN THE SPRING. ANYWAY...ISSUED
SEVERAL SPS FOR THESE.
ADJUSTED POPS DOWN ACROSS THE NORTHWEST AND UP SOME ACROSS
THE EAST AND SE FOR A FEW HOURS.
MORE STORMS NORTH OF LAKE ERIE MAY MOVE IN LATE. POPS FOR
THAT TIME FRAME LOOK GOOD AT THIS POINT.
ADJUSTED CURRENT TEMPS SOME.
ADDED PATCHY FOG LATE.
MID AFTERNOON DISCUSSION.
DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER
NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT
MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE
INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE
NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALF
OFMY FCST AREA.
CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN
SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT
BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD
STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING
OVERALL ORGANIZATION.
SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS
ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL
MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE
SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER
LAKES LATER TONIGHT.
OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY
NEAR SEASONAL NORMS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN
PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A
RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS
UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH
SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT
FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD
FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK
FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A
SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING
INTO THE AREA.
RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN
THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
QUALITY/REFRESHING LOW PWAT AIRMASS BEING DIRECTED EQUATORWARD
VIA NLY FLOW BEHIND REINFORCING COLD FRONT WILL BRING AN END TO
SCT SHOWER/TSTM ACTIVITY ACROSS THE SRN TIER ZONES EARLY WED NGT.
LG SCALE FORCING ON SW FRINGE OF SLOWLY PROGRESSING MID-UPPER LVL
TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST STATES...ALONG
WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL LAPSE RATES
NEAR 6 C/KM ASSOCD WITH -15C AT 500MB AND ANOMALOUS H7 TEMPS MAY
INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON THU.
GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-UP
APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN.
OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY
AND 5-10KT NNW WIND.
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
IN THE WAKE OF SCATTERED SHOWERS AND THUNDERSTORMS THAT MOVED
ACROSS THE AIR SPACE THIS EVENING...MOST SITES HAVE RETURNED TO
VFR. THE NOTABLE EXCEPTION IS KBFD WHERE LIFR CIGS BEHIND THE
CONVECTION WILL LIKLEY CONTINUE MOST OF THE NIGHT. NORTHERLY WINDS
SHOULD BECOME LIGHT AND VARIABLE OVER THE NEXT COUPLE OF HOURS.
LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN
OVERNIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND
FOG...ESPECIALLY WHERE RAIN FELL TODAY.
A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS
ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY.
DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE
NORTH LATER IN THE DAY.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
945 PM EDT TUE AUG 5 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS EVENING. A
STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH
WEDNESDAY...FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT
WILL LAST INTO THIS COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
BEEN TRACKING A LONG DURATION...FAST MOVING GUST FRONT ACROSS
THE AREA. WIND GUST TO AROUND 40 MPH...AND A TEMP DROP OF
10 TO 15 DEGREES. NORMALLY SEE THESE EARLY IN THE SPRING.
ANYWAY...ISSUED SEVERAL SPS FOR THESE.
ADJUSTED POPS DOWN ACROSS THE NORTHWEST AND UP SOME ACROSS
THE EAST AND SE FOR A FEW HOURS.
MORE STORMS NORTH OF LAKE ERIE MAY MOVE IN LATE. POPS FOR
THAT TIME FRAME LOOK GOOD AT THIS POINT.
ADJUSTED CURRENT TEMPS SOME.
ADDED PATCHY FOG LATE.
EARLIER DISCUSSION BELOW.
DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER
NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT
MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE
INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE
NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALF
OFMY FCST AREA.
CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN
SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT
BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD
STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING
OVERALL ORGANIZATION.
SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS
ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL
MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE
SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER
LAKES LATER TONIGHT.
OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY
NEAR SEASONAL NORMS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN
PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A
RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS
UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH
SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT
FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD
FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK
FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A
SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING
INTO THE AREA.
RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN
THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
QUALITY/REFRESHING LOW PWAT AIRMASS BEING DIRECTED EQUATORWARD
VIA NLY FLOW BEHIND REINFORCING COLD FRONT WILL BRING AN END TO
SCT SHOWER/TSTM ACTIVITY ACROSS THE SRN TIER ZONES EARLY WED NGT.
LG SCALE FORCING ON SW FRINGE OF SLOWLY PROGRESSING MID-UPPER LVL
TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST STATES...ALONG
WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL LAPSE RATES
NEAR 6 C/KM ASSOCD WITH -15C AT 500MB AND ANOMALOUS H7 TEMPS MAY
INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON THU.
GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-UP
APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN.
OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY
AND 5-10KT NNW WIND.
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
IN THE WAKE OF SCATTERED SHOWERS AND THUNDERSTORMS THAT MOVED
ACROSS THE AIR SPACE THIS EVENING...MOST SITES HAVE RETURNED TO
VFR. THE NOTABLE EXCEPTION IS KBFD WHERE LIFR CIGS BEHIND THE
CONVECTION WILL LIKLEY CONTINUE MOST OF THE NIGHT. NORTHERLY WINDS
SHOULD BECOME LIGHT AND VARIABLE OVER THE NEXT COUPLE OF HOURS.
LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN
OVERNIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND
FOG...ESPECIALLY WHERE RAIN FELL TODAY.
A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS
ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY.
DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE
NORTH LATER IN THE DAY.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
749 PM EDT TUE AUG 5 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS AFTERNOON AND
EVENING. A STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH
WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT WILL
LAST INTO THIS UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
BEEN TRACKING A LONG DURATION...FAST MOVING GUST FRONT ACROSS
THE AREA. WIND GUST TO AROUND 40 MPH...AND A TEMP DROP OF
10 TO 15 DEGREES. NORMALLY SEE THESE EARLY IN THE SPRING.
ANYWAY...ISSUED SEVERAL SPS FOR THESE.
ADJUSTED POPS DOWN ACROSS THE NORTHWEST AND UP SOME ACROSS
THE EAST AND SE FOR A FEW HOURS.
MORE STORMS NORTH OF LAKE ERIE MAY MOVE IN LATE. POPS FOR
THAT TIME FRAME LOOK GOOD AT THIS POINT.
ADJUSTED CURRENT TEMPS SOME.
ADDED PATCHY FOG LATE.
EARLIER DISCUSSION BELOW.
DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER
NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT
MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE
INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE
NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALF
OFMY FCST AREA.
CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN
SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT
BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD
STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING
OVERALL ORGANIZATION.
SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS
ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL
MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE
SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER
LAKES LATER TONIGHT.
OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY
NEAR SEASONAL NORMS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN
PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A
RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS
UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH
SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT
FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD
FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK
FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A
SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING
INTO THE AREA.
RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN
THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
QUALITY/REFRESHING LOW PWAT AIRMASS BEING DIRECTED EQUATORWARD
VIA NLY FLOW BEHIND REINFORCING COLD FRONT WILL BRING AN END TO
SCT SHOWER/TSTM ACTIVITY ACROSS THE SRN TIER ZONES EARLY WED NGT.
LG SCALE FORCING ON SW FRINGE OF SLOWLY PROGRESSING MID-UPPER LVL
TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST STATES...ALONG
WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL LAPSE RATES
NEAR 6 C/KM ASSOCD WITH -15C AT 500MB AND ANOMALOUS H7 TEMPS MAY
INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON THU.
GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-UP
APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN.
OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY
AND 5-10KT NNW WIND.
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
ALL TERMINALS ARE VFR AND THIS WILL CONTINUE INTO THE EVENING.
EXCEPTIONS WILL BE WHERE DEVELOPING CONVECTION WANDERS INTO
TERMINAL AIRSPACE THROUGH LATE AFTERNOON. THE BEST CHANCE OF THIS
WILL BE OVER THE FAR NORTH IN AND AROUND BRADFORD...AND POSSIBLYINTO
WILLIAMSPORT AFTER 20Z.
SHOWERS AND THUNDERSTORMS WILL TEND TO FADE AS WE LOSE THE SUN.
LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN
TONIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND FOG.
A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS
ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY.
DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE
NORTH LATER IN THE DAY.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
745 PM EDT TUE AUG 5 2014
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH ACROSS THE STATE THIS AFTERNOON AND
EVENING. A STRONGER COLD FRONT WILL MOVE THROUGH THE COMMONWEALTH
WEDNESDAY FOLLOWED BY COOLER AND LESS HUMID CONDITIONS THAT WILL
LAST INTO THIS UPCOMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
BEEN TRACKING A LONG DURATION...FAST MOVING GUST FRONT ACROSS
THE AREA. WIND GUST TO AROUND 40 MPH...AND A TEMP DROP OF
10 TO 15 DEGREES. NORMALLY SEE THESE EARLY IN THE SPRING.
ANYWAY...ISSUED SEVERAL SPS FOR THESE.
ADJUSTED POPS DOWN ACROSS THE NORTHWEST AND UP SOME ACROSS
THE EAST AND SE FOR A FEW HOURS.
MORE STORMS NORTH OF LAKE ERIE MAY MOVE IN LATE. POPS FOR
THAT TIME FRAME LOOK GOOD AT THIS POINT.
ADJUSTED CURRENT TEMPS SOME.
ADDED PATCHY FOG LATE.
EARLIER DISCUSSION BELOW.
DEEP MOISTURE CONVERGENCE AND CAPES IN THE 1000-15000J RANGE OVER
NORTHERN PA IS RESULTING IN SHOWERS AND THUNDERSTORMS BREAKING OUT
MAINLY NORTH OF I-80. HRRR SEEMS A LITTLE SLOW IN CONVECTIVE
INITIATION...BUT SEEMS TO HAVE THE MODE CORRECT AND SUPPORTS THE
NEAR TERM IDEA OF KEEPING CONVECTION MAINLY OVER THE NORTHERN HALF
OFMY FCST AREA.
CROSS SECTIONS THROUGH THE STORMS SHOWS SOME ELEVATED CORES IN
SOME OF THE MORE ROBUST UPDRAFTS...MEANING SOME GUSTY WINDS CANNOT
BE RULED OUT IN A FEW STORMS. BUT THE OVERALL SEVERE THREAT SHOULD
STAY MINIMAL TODAY WITH MOST STORMS BEING PULSE TYPES AND LACKING
OVERALL ORGANIZATION.
SHOWER ACTIVITY IS EXPECTED TO FADE WITH THE LOSS OF THE SUN AS
ALL INDICATORS SHOW INSTABILITY DWINDLING QUICKLY. I KEPT A SMALL
MENTION OF PRECIP OVER NORTHERN AREAS EVEN AFTER MIDNIGHT AS THE
SECOND STRONGER COLD FRONT TAKES SHAPE AS IT DROPS INTO THE LOWER
LAKES LATER TONIGHT.
OVERNIGHT LOWS FROM THE MOD 50S TO MID 60S NW TO SE WILL BE VERY
NEAR SEASONAL NORMS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/...
WEDNESDAY...A VIGOROUS UPPER JET STREAK IS MADE TO DIVE INTO SWRN
PA DURING THE AFTERNOON. MODELS GENERATE STRONG SHEAR AND A
RESPECTABLE AMOUNT OF CAPE ON AND TO THE LEFT OF THE NOSE OF THIS
UPPER JET STREAK. INSTABILITY AS ALWAYS WILL DEPEND ON HOW MUCH
SUN WE CAN MANAGE...BUT ISOLATED SEVERE STORMS CANNOT BE RULED OUT
FROM MID MORNING INTO THE AFTERNOON HOURS AS THE SECONDARY COLD
FRONT SAGS SOUTH. RIGHT NOW WE ARE IN A GENERAL THUNDER OUTLOOK
FROM SPC...BUT WOULD NOT BE SURPRISED IF WE ARE ELEVATED TO A
SLIGHT RISK GIVEN YET ANOTHER ANOMALOUSLY STRONG SYSTEM MOVING
INTO THE AREA.
RIGHT NOW I HAVE TEMPS DIALED A NOTCH BELOW TODAY`S READINGS GIVEN
THE EXPECTATIONS OF MORE CLOUDS AND SHOWER ACTIVITY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/...
QUALITY/REFRESHING LOW PWAT AIRMASS BEING DIRECTED EQUATORWARD
VIA NLY FLOW BEHIND REINFORCING COLD FRONT WILL BRING AN END TO
SCT SHOWER/TSTM ACTIVITY ACROSS THE SRN TIER ZONES EARLY WED NGT.
LG SCALE FORCING ON SW FRINGE OF SLOWLY PROGRESSING MID-UPPER LVL
TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST STATES...ALONG
WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL LAPSE RATES
NEAR 6 C/KM ASSOCD WITH -15C AT 500MB AND ANOMALOUS H7 TEMPS MAY
INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON THU.
GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-UP
APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN.
OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY
AND 5-10KT NNW WIND.
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
ALL TERMINALS ARE VFR AND THIS WILL CONTINUE INTO THE EVENING.
EXCEPTIONS WILL BE WHERE DEVELOPING CONVECTION WANDERS INTO
TERMINAL AIRSPACE THROUGH LATE AFTERNOON. THE BEST CHANCE OF THIS
WILL BE OVER THE FAR NORTH IN AND AROUND BRADFORD...AND POSSIBLYINTO
WILLIAMSPORT AFTER 20Z.
SHOWERS AND THUNDERSTORMS WILL TEND TO FADE AS WE LOSE THE SUN.
LOCAL MVFR/IFR RESTRICTIONS WILL BECOME POSSIBLE ONCE AGAIN
TONIGHT WITH THE FORMATION OF AREAS OF LOW CLOUDS AND FOG.
A STRONGER COLD FRONT WILL BRING A BETTER CHANCE OF RESTRICTIONS
ASSOCIATED WITH WIDESPREAD SHOWERS AND THUNDERSTORMS WEDNESDAY.
DRIER AIR AND IMPROVING CONDITIONS WILL TEND TO WORK IN FROM THE
NORTH LATER IN THE DAY.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/MARTIN
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
122 PM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1053 AM CDT MON AUG 4 2014
HAVE UPDATED THE FORECAST TO BROADEN THE CHANCE OF THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. COMPLEX OF STORMS ACROSS
NORTH CENTRAL SOUTH DAKOTA DRIFTING SOUTH SOUTH EAST. WHILE THE
BETTER JET DYNAMICS ARE ACROSS THE EASTERN HALF OF THE FORECAST
AREA...STORMS CONTINUE TO BUILD INTO AN UNSTABLE ENVIRONMENT. WITH
ELEVATED CAPE OF 1-2K...UPDATED THE HWO TO ADD MENTION OF HAIL.
SHEAR PROFILES ARE FAR FROM IDEAL...BUT STRONGEST STORMS THIS
AFTERNOON MAY APPROACH THE LOW END OF SEVERE WITH HAIL BEING THE
MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 119 PM CDT MON AUG 4 2014
VFR CONDITIONS SHOULD PREVAIL THROUGH THE PERIOD. ISOLATED TO
SCATTERED SHOWERS AND STORMS ARE POSSIBLE THROUGH THIS AFTERNOON
INTO EARLY THIS EVENING. GIVEN SPORADIC COVERAGE AND OVERALL LACK
OF RESTRICTION TO VISIBILTY...DID NOT ADD MENTION INTO THE
FORECAST. MORE WIDESPREAD ACTIVITY SHOULD DEVELOP AFTER MIDNIGHT
WITH WARM AIR ADVIECTION. TIMING AT TAF SITES IS NOT CERTAIN...SO
FOR NOW...HAVE LEFT MENTION OUT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JH
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1058 AM CDT MON AUG 4 2014
.UPDATE...
ISSUED AT 1053 AM CDT MON AUG 4 2014
HAVE UPDATED THE FORECAST TO BROADEN THE CHANCE OF THUNDERSTORMS
THIS AFTERNOON INTO THE EVENING HOURS. COMPLEX OF STORMS ACROSS
NORTH CENTRAL SOUTH DAKOTA DRIFTING SOUTH SOUTH EAST. WHILE THE
BETTER JET DYNAMICS ARE ACROSS THE EASTERN HALF OF THE FORECAST
AREA...STORMS CONTINUE TO BUILD INTO AN UNSTABLE ENVIRONMENT. WITH
ELEVATED CAPE OF 1-2K...UPDATED THE HWO TO ADD MENTION OF HAIL.
SHEAR PROFILES ARE FAR FROM IDEAL...BUT STRONGEST STORMS THIS
AFTERNOON MAY APPROACH THE LOW END OF SEVERE WITH HAIL BEING THE
MAIN THREAT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 623 AM CDT MON AUG 4 2014
TAF PERIOD BEGINS WITH PATCHY MVFR VISIBILITY IN BR...WITH VERY
LOCALIZED IFR-LIFR VISIBILITY...BUT CONDITIONS EXPECTED TO IMPROVE
RAPIDLY WITH VFR CONDITIONS THEN EXPECTED TO PREVAIL. SHOWERS AND
THUNDERSTORMS WILL AGAIN BECOME ISOLATED TO SCATTERED THROUGHOUT THE
REGION BY MID TO LATE MORNING...WITH ACTIVITY WANING BY SUNSET. KHON
AND KFSD MORE LIKELY TO SEE A BRIEF THUNDER THREAT DURING THE LATE
MORNING THROUGH MID AFTERNOON...BUT DUE TO EXPECTED SPOTTY COVERAGE
OF TSRA...HAVE NOT INCLUDED MENTION IN TAFS AT THIS TIME. SCATTERED
TSRA EXPECTED TO SPREAD BACK INTO THE REGION FROM THE SOUTHWEST AFTER
04Z TONIGHT...POSSIBLY REACHING TAF LOCATIONS AFTER 08Z TUESDAY.
HOWEVER AGAIN WITH UNCERTAINTY IN TIMING/COVERAGE...OPTED TO LEAVE
MENTION OUT OF THIS TAF SET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...
SHORT TERM...JH
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
623 AM CDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 623 AM CDT MON AUG 4 2014
TAF PERIOD BEGINS WITH PATCHY MVFR VISIBILITY IN BR...WITH VERY
LOCALIZED IFR-LIFR VISIBILITY...BUT CONDITIONS EXPECTED TO IMPROVE
RAPIDLY WITH VFR CONDITIONS THEN EXPECTED TO PREVAIL. SHOWERS AND
THUNDERSTORMS WILL AGAIN BECOME ISOLATED TO SCATTERED THROUGHOUT THE
REGION BY MID TO LATE MORNING...WITH ACTIVITY WANING BY SUNSET. KHON
AND KFSD MORE LIKELY TO SEE A BRIEF THUNDER THREAT DURING THE LATE
MORNING THROUGH MID AFTERNOON...BUT DUE TO EXPECTED SPOTTY COVERAGE
OF TSRA...HAVE NOT INCLUDED MENTION IN TAFS AT THIS TIME. SCATTERED
TSRA EXPECTED TO SPREAD BACK INTO THE REGION FROM THE SOUTHWEST AFTER
04Z TONIGHT...POSSIBLY REACHING TAF LOCATIONS AFTER 08Z TUESDAY.
HOWEVER AGAIN WITH UNCERTAINTY IN TIMING/COVERAGE...OPTED TO LEAVE
MENTION OUT OF THIS TAF SET.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
404 AM CDT MON AUG 4 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 404 AM CDT MON AUG 4 2014
MOST ACTIVITY EARLY THIS MORNING WEST OF THE FORECAST AREA...AND
APPEARS TO BE FOCUSED ALONG ZONE OF LOW-MID LEVEL FRONTOGENESIS OVER
SOUTHWEST/SOUTH CENTRAL SD. STRONGER FRONTOGENESIS EDGES EASTWARD
INTO OUR FAR WESTERN FORECAST AREA THROUGH MID MORNING...WEAKENING
BY MIDDAY PER RECENT RAP MODEL RUNS. FOR NOW OPTED TO KEEP POPS WEST
OF THE JAMES IN THE ISOLATED-LOW SCATTERED RANGE GIVEN HIGH CLOUD
BASES GENERALLY 10KFT OR ABOVE. LATER MORNING INTO EARLY AFTERNOON
ANTICIPATE DEVELOPMENT FARTHER NORTHEAST IN ADVANCE OF A WEAK MID
LEVEL WAVE ROLLING OUT OF EASTERN MT/WESTERN ND. SOME UNCERTAINTY
REGARDING HOW FAR NORTHEAST THIS DEVELOPMENT MAY BE AS 04/06Z NAM
HOLDS ONTO STRONGER FRONTOGENESIS THROUGH THE MISSOURI VALLEY...SO
LATER SHIFTS MAY NEED TO ADJUST HIGHER POPS SOUTHWARD IF THIS PANS
OUT. FORECAST SOUNDINGS SHOW MEAGER MID LEVEL LAPSE RATES AND WEAK
DEEP LAYER SHEAR LESS THAN 30KT...SO SEVERE STORMS NOT EXPECTED AT
THIS TIME.
THIS ACTIVITY EXPECTED TO WANE THROUGH THE LATE AFTERNOON AND EARLY
EVENING AS THE WAVE PULLS AWAY FROM THE AREA...WITH FOCUS SHIFTING
TO STRONGER WARM ADVECTION PUSH INTO THE WESTERN/SOUTHERN FORECAST
AREA OVERNIGHT. INSTABILITY AND SHEAR ON THE WEAKER SIDE...SO AGAIN
NOT EXPECTING ANYTHING SEVERE WITH THE OVERNIGHT ACTIVITY.
WITH FAIR AMOUNT OF MID LEVEL CLOUD COVER/POTENTIAL FOR SCATTERED
SHOWERS/STORMS TODAY...TEMPERATURES SHOULD BE A FEW DEGREES COOLER
THAN YESTERDAY OVER OUR NORTHEAST...WHILE SOUTHWEST AREAS CLIMB A
BIT HIGHER AS SLIGHTLY WARMER LOW LEVEL AIR WORKS INTO THAT AREA.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 404 AM CDT MON AUG 4 2014
LOW PRESSURE OVER WESTERN NEBRASKA WILL CONTINUE TO DEEPEN ON
TUESDAY AS A WARM FRONT LIFTS CLOSE TO THE SOUTHERN PORTIONS OF OUR
CWA. WILL SEE CONTINUING THUNDERSTORM CHANCES DURING THE DAY IN
INCREASING THETA E ADVECTION OVER THE AREA WITH A DECENT LOW/MID
LEVEL BOUNDARY SETTING ACROSS THE REGION. ALL OF THIS CULMINATING ON
TUESDAY NIGHT AS UPPER LEVEL SUPPORT INCREASES AND A LOW LEVEL JET
EMANATING FROM THE GULF OF MEXICO STRENGTHENS THROUGH THE CENTRAL
PLAINS. MODELS STILL DIVERGING A BIT ON WHERE EXACTLY THE LOW/MID
LEVEL BOUNDARIES WILL SET UP OVER OUR AREA...WHICH WILL MAKE A
DIFFERENCE ON WHICH AREAS RECEIVE THE HEAVIEST RAINFALL...BUT THE
GENERAL CONSENSUS AT THIS POINT WOULD BE ALONG THE INTERSTATE 90
CORRIDOR AND SOUTHWARD. STILL LOOKING AT MODEL PRECIPITABLE WATER
VALUES RUNNING AROUND 2 INCHES ON TUESDAY NIGHT...GIVING SUPPORT TO
PROBABLE HEAVY RAIN OVER PORTIONS OF THE AREA WITH THESE STORMS.
WHILE RAINFALL CHANCES WILL CONTINUE INTO WEDNESDAY...THINK THERE
WILL BE A GENERAL DECREASE IN COVERAGE THROUGH THE DAY AS FRONTAL
DYNAMICS/UPPER LEVEL SUPPORT SHIFTS OFF TO THE EAST. WITH
CLOUDS/SHOWERS AND AN EASTERLY LOW LEVEL FLOW...TUESDAY AND
WEDNESDAY WILL SEE DAYTIME TEMPERATURES BELOW NORMAL FOR THIS TIME
OF YEAR WITH HIGHS IN THE MID TO UPPER 70S.
FOR THE END OF THE WEEK INTO NEXT WEEKEND...CONFIDENCE IS LOW WITH
MODEL DIFFERENCES ON ASSORTED SHORTWAVES EMBEDDED IN THE UPPER LEVEL
FLOW...PAINTING A CHANCE OF PRECIPITATION SOMEWHERE ACROSS THE AREA
EACH DAY THROUGH THE EXTENDED PERIOD. BECAUSE OF THESE
DIFFERENCES...THERE ARE ALSO THERMAL FIELD DISCREPANCIES...THOUGH
THE GENERAL CONSENSUS IS FOR TEMPERATURES TO REMAIN JUST BELOW
NORMAL...ALTHOUGH WARMING SUBTLY THROUGH THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1055 PM CDT SUN AUG 3 2014
GENERALLY VFR CONDITIONS WILL CONTINUE THROUGH 05/06Z. ISOLATED
-TSRA POSSIBLE MAINLY NORTHERN PART OF THE FORECAST AREA DURING
THE PERIOD. FOR NOW CHANCE AT ANY POINT IS TOO LOW TO INCLUDE IN
TAF FORECASTS. ALSO A POSSIBILITY IS LOWERING OF VISIBILITY TO
3-5SM IN PATCHY LIGHT FOG 09Z-14Z. FOR EXPECTED AREAS OF CLOUD
COVER AND SOME WEAK LOW LEVEL FLOW HAVE ALSO LEFT THIS OUT OF TAF
FORECASTS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JH
LONG TERM...JM
AVIATION...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
706 PM CDT TUE AUG 5 2014
.UPDATE...FOR 00Z AVIATION FORECAST
&&
.AVIATION...
SPRINKLES AND AN ISOLATED SHOWER OR TWO HAVE BEEN OCCURRING LAST
COUPLE OF HOURS IN MIDDLE TENNESSEE BUT NOTHING OF SIGNIFICANCE.
SHORT WAVE DROPPING SOUTHEAST DOWN THROUGH SOUTHEASTERN MISSOURI
AND SOUTHERN ILLINOIS HAS TRIGGERED SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WORKING DOWN THROUGH THAT AREA. GFS SHOWS A MOISTURE
PLUME ACROSS BOOTHEEL INTO WESTERN TENNESSEE THIS EVENING AHEAD OF
SHORT WAVE. CURRENTLY THE RUC AND H-TRIPLE-R DIMINISH THIS ACTIVITY
OVER ONCE IT GETS INTO FAR WESTERN KENTUCKY AROUND 01Z. AM EXPECTING
SOME LATE NIGHT MVFR FOG AT BOTH CLARKSVILLE AND CROSSVILLE WITH
MID LEVEL CLOUDINESS ACROSS THE AREA.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
BOYD
01
AREA FORECAST DISCUSSION...UPDATED
NWS LUBBOCK TX
937 PM CDT TUE AUG 5 2014
.UPDATE...
AT 920 PM...A SMALL T-STORM COMPLEX WAS MOVING SE OUT OF NE NM INTO
THE WRN TX PANHANDLE. THE LOW-LEVEL JET IS A LITTLE STRONGER THAN
PREVIOUS NIGHTS...BUT INSTABILITY AND MID-LVL FLOW IS NOT VERY
SUPPORTIVE FOR SUSTAINING THIS ACTIVITY AS FAR AS OUR CWA TONIGHT.
THE HRRR SUGGESTS THAT WE COULD SEE SOME DECAYING SHOWERS ARRIVE
IN NORTHERN PORTIONS OF PARMER...CASTRO AND SWISHER COUNTIES
AROUND 1 TO 2 AM. FOR NOW 10 PERCENT POPS IN THIS AREA SHOULD
SUFFICE AND WE/LL CONTINUE TO MONITOR THE STORMS. OTHERWISE...SOME
MINOR ADJUSTMENTS MADE TO WIND AND SKY COVER GRIDS.
&&
.PREV DISCUSSION... /ISSUED 639 PM CDT TUE AUG 5 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS FOR THE NEXT 24
HOURS. VARIABLE CLOUDINESS ABOVE APPROX. 7K FT IS EXPECTED ALONG
WITH SRLY SFC WINDS...WHICH WILL BECOME A BIT BREEZY AROUND DAYBREAK.
PREV DISCUSSION... /ISSUED 350 PM CDT TUE AUG 5 2014/
SHORT TERM...
HIGH PRESSURE REMAINS IN CONTROL OVER THE SOUTHERN STATES WITH SOME
MONSOONAL MOISTURE PRESENT ACROSS CENTRAL NEW MEXICO. WITH THE
LIGHT ANTI-CYCLONIC FLOW....STORMS SHOULD GENERALLY REMAIN WELL
WEST OF THE AREA THOUGH AN AREA OF WEAK CONVERGENCE HAS SET UP
ACROSS THE NORTHWESTERN ZONES. A FEW PINHEAD SHOWERS HAVE
ATTEMPTED TO GET GOING AND THERE REMAINS SOME LOW PROBABILITIES OF
AN HONEST THUNDERSTORM TO GET GOING...CONFIDENCE REMAINS LOW FOR
ANYTHING SIGNIFICANT TO GET GOING. TEMPERATURES TONIGHT WILL BE
FAIRLY TYPICAL OF THIS TIME OF YEAR WITH A HOTTER WEDNESDAY AS
SKIES BECOME A BIT LESS OBSCURED. THUS...WE WILL CALL FOR HIGHS UP
NEAR THE CENTURY MARK.
LONG TERM...
FAVORABLE CHANCES FOR CONVECTION WILL MOSTLY BE LIMITED TO NEW
MEXICO AND THE PANHANDLES. A COLD FRONT WILL ATTEMPT TO MAKE A RUN
AT THE AREA ON THURSDAY BUT STOPS SHORT BEFORE DISSIPATING. THE
CENTER OF THE UPPER RIDGE WILL BE CLOSE TO OVERHEAD BY FRIDAY WITH A
WEAK SHORT WAVE MOVING THROUGH CENTRAL NEW MEXICO. THIS SHORT WAVE
LOOKS TO BE TOO FAR AWAY TO HAVE ANY CONVECTION IMPACT ON WEST
TEXAS. CONVECTION WILL LIKELY BE LIMITED TO THE WEST AND NORTH OF
THE REGION THIS WEEKEND AS THE RIDGE SHIFTS A LITTLE MORE TO THE
SOUTH AND EAST. THE RIDGE WILL SHIFT BACK WEST NEXT WEEK ALLOWING
FOR STRONGER NORTHWEST FLOW AND POSSIBLY A FEW FRONTS TO ENCROACH BY
THE MIDDLE OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 96 64 96 65 / 10 0 10 10 10
TULIA 65 97 67 98 66 / 10 10 10 10 10
PLAINVIEW 66 97 66 96 66 / 0 0 10 10 10
LEVELLAND 66 98 67 97 66 / 0 0 0 10 10
LUBBOCK 70 99 70 98 69 / 0 0 0 10 10
DENVER CITY 65 97 66 97 66 / 0 0 0 10 0
BROWNFIELD 66 99 67 97 66 / 0 0 0 10 0
CHILDRESS 70 100 72 101 72 / 0 10 10 10 10
SPUR 68 101 70 100 69 / 0 0 0 10 0
ASPERMONT 72 101 73 100 72 / 0 10 0 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
932 PM CDT TUE AUG 5 2014
.UPDATE...
SEE EVENING UPDATE.
&&
.DISCUSSION...
HIGH PRESSURE WAS OVER THE EASTERN GULF AND A WEAK AREA OF LOW
PRESSURE WAS NOTED OVER SE COLORADO. A WEAK SURFACE TROUGH
EXTENDED FROM ABOUT KLFK TO KCOT. AT THE 850-700 LAYER...A RIBBON
OF SLIGHTLY DEEPER MOISTURE EXTENDS FROM NE TEXAS TO SOUTHERN
LOUISIANA WITH A WEAK S/WV NOTED FROM ABOUT SAN LUIS PASS TO
COLLEGE STATION. AT THE UPPER LEVELS...A WELL DEVELOPED UPPER
LEVEL HIGH WAS LOCATED OVER NE SONORA IN MEXICO. THE HIGH HAS
EXPANDED SINCE LAST EVENING AND NOW EXTENDS INTO EASTERN TEXAS.
GFS MASS FIELDS STILL SUPPORT RAIN CHANCE FOR WEDNESDAY WHILE
OTHER GLOBAL MODELS ARE TRENDING DRIER. PW VALUES ARE PROGGED TO
FALL TO BETWEEN 1.4 AND 1.6 INCHES FROM THIS AFTERNOONS VALUE OF
AROUND 1.80 INCHES. THE RAP AND 4KM NCEP WRF ARE TRENDING DRIER
AND SUPPORT THE NAM/ECMWF. STILL FEEL SHRA WILL BE POSSIBLE ON
WEDNESDAY BUT COVERAGE SHOULD BE CONSIDERABLY MORE ISOLATED THAN
TODAY.
SHRA/TSRA ARE WANING QUICKLY WITH THE LOSS OF HEATING AND NOT
EXPECTING MUCH IN THE WAY OF ADDITIONAL ACTIVITY OVERNIGHT. WILL
ISSUE NEW ZONES TO CLEAN UP EVENING WORDING...REMOVE POPS ETC...
43
&&
.CLIMATE...
SOME INTERESTING CLIMATE STATS TO BANTER ABOUT THIS EVENING.
COLLEGE STATION HAS RECORDED ONLY 11 DAYS WITH TEMPERATURES AT OR
ABOVE 95 DEGREES IN 2014. TYPICALLY...COLLEGE STATION HAS RECORDED
30 SUCH DAYS BY AUGUST 5TH (1981-2010). HOUSTON HAS ONLY RECORDED
9 DAYS WITH TEMPS AT OR ABOVE 95 DEGREES BUT TYPICALLY WOULD HAVE
TALLIED 26 SUCH DAYS BY THE 5TH.
SINCE THE SUMMER HAS BEEN COOL BY TEXAS STANDARDS...THOUGHT IT
MIGHT BE INTERESTING TO SEE HOW MANY DAYS HAVE BEEN BELOW NORMAL
SINCE JUNE 1ST. COLLEGE STATION HAS RECORDED 30 DAYS OF BELOW
NORMAL TEMPERATURES AND 10 DAYS OF NORMAL TEMPERATURES SINCE JUNE
1ST OR 40 OUT OF 66 DAYS WITH NORMAL OR BELOW NORMAL TEMPERATURES.
WHAT A DIFFERENCE FROM THE SUMMER OF 2011. HOUSTON RECORDED 29
DAYS BELOW NORMAL AND 14 DAYS AT NORMAL OR 43 OUT OF 66 DAYS AT OR
BELOW NORMAL.
ONE LAST TIDBIT...COLLEGE STATION AND HOUSTON HAVE YET TO RECORD A
RECORD HIGH TEMPERATURE SO FAR THIS YEAR. HOUSTON RECORDED IT`S
LAST HIGH TEMPERATURE RECORD ON NOVEMBER 17 2013 AND COLLEGE
STATION HAS NOT RECORDED A HIGH TEMPERATURE RECORD SINCE JULY 13
2013 - OVER A YEAR AGO. 43
&&
.PREV DISCUSSION... /ISSUED 619 PM CDT TUE AUG 5 2014/
DISCUSSION...
SEE THE 00Z AVIATION DISCUSSION BELOW.
40
AVIATION...
A NORTHEASTERLY AND SLIGHTLY DIFFLUENT FLOW ALOFT COMBINED WITH A
FAIRLY MOIST AIRMASS TO HELP GENERATE SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS ALONG THE SEABREEZE EARLIER THIS AFTERNOON.
THE NAM BUFR FORECAST SOUNDINGS MEASURED PW/S OF 1.8 TO NEARLY 2
INCHES OVER THE INLAND AREAS DURING THE LATE AFTERNOON PERIOD. THE
HIGH RESOLUTION ARW AND NMN WERE DOING A DECENT JOB WITH THE
COVERAGE. BOTH FORECAST THE ACTIVITY TO DISSIPATE SHORTLY AFTER
THE FORECAST ISSUANCE.
OTHERWISE...VFR IS EXPECTED THROUGH THE PERIOD FOR MOST SITES. THE
EXCEPTION WILL BE AT KUTS AND KCXO WHERE SOME RAINFALL THIS
AFTERNOON SHOULD LEAD TO AT LEAST MVFR VISIBILITIES DEVELOPING
BETWEEN 06Z AND 11Z. THERE MAY ALSO BE SOME PATCHY GROUND FOG
DEVELOPING THIS EVENING.
FOR TOMORROW AFTERNOON...THE MODELS DEVELOP THE UPPER LEVEL RIDGE
EASTWARD INTO SOUTHEAST TEXAS. HOWEVER...THE HIGHER RESOLUTION
MODELS ARE AGAIN FORECASTING AN ACTIVE SEABREEZE. THIS SHOULD
LEAD TO AT LEAST ISOLATED SHOWERS AT AND NEAR THE COAST AROUND OR
AFTER SUNRISE WITH ISOLATED THUNDERSTORMS POSSIBLE DURING THE
AFTERNOON.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 95 77 96 77 / 10 20 10 10 10
HOUSTON (IAH) 76 95 77 95 77 / 10 20 10 20 10
GALVESTON (GLS) 80 91 81 91 81 / 20 20 20 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1235 PM CDT MON AUG 4 2014
.AVIATION...
/|18Z TAFS/
VFR expected for the next 24 hours. Scattered CUmulus should
develop in the next few hours...with more dense cloud cover mainly
south of a SJT to BWD line. A few showers will be possible near
the JCT/SOA areas by late afternoon...but not enough confidence or
coverage to warrant mention of thunder in the TAFS. Light winds
and mostly clear skies expected overnight.
08
&&
.PREV DISCUSSION... /ISSUED 601 AM CDT MON AUG 4 2014/
AVIATION...
/12Z TAFS/
VFR conditions are expected to prevail today and tonight at
the TAF sites. Expect a cumulus field to develop across our
eastern and central counties late this morning and afternoon.
There is a slight chance of showers and thunderstorms across
the area generally southeast of a Sonora to Lake Brownwood
line this afternoon and evening. With the low anticipated
coverage however, not including a mention in the TAFs at
this time. Any lingering convection will dissipate by sunset,
with clear to partly cloudy skies expected overnight. Winds
will be from the east or east-northeast at 5-10 KT today, and
from the east-southeast at decreased speeds tonight.
PREV DISCUSSION... /ISSUED 333 AM CDT MON AUG 4 2014/
SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The combination
of surface heating, moisture increase and marginally sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 72 97 / 5 10 5 5 5
San Angelo 93 68 95 72 98 / 5 10 5 5 5
Junction 92 69 94 71 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
601 AM CDT MON AUG 4 2014
.AVIATION...
/12Z TAFS/
VFR conditions are expected to prevail today and tonight at
the TAF sites. Expect a cumulus field to develop across our
eastern and central counties late this morning and afternoon.
There is a slight chance of showers and thunderstorms across
the area generally southeast of a Sonora to Lake Brownwood
line this afternoon and evening. With the low anticipated
coverage however, not including a mention in the TAFs at
this time. Any lingering convection will dissipate by sunset,
with clear to partly cloudy skies expected overnight. Winds
will be from the east or east-northeast at 5-10 KT today, and
from the east-southeast at decreased speeds tonight.
&&
.PREV DISCUSSION... /ISSUED 333 AM CDT MON AUG 4 2014/
SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The combination
of surface heating, moisture increase and marginally sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 73 97 / 5 10 5 5 5
San Angelo 93 68 95 71 98 / 5 10 5 5 5
Junction 92 69 94 72 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
Aviation and Short Term: 19
Long Term: Johnson
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
333 AM CDT MON AUG 4 2014
.SHORT TERM...
(Today and Tonight)
A weak lower to mid-level disturbance along the Texas coast will
move to the southwest today, while the upper ridge remains in
place from northern Mexico and the Texas Big Bend region north
into the central Rockies.
As the disturbance moves southwest today, associated lower to
mid-level moisture will move west into our area. The ridge to our
west is not strong and more of a "dirty ridge." The combination
of surface heating, moisture increase and sufficient
destabilization could allow isolated or widely scattered showers
and thunderstorms to develop over our east-central and
southeastern counties, mainly during the afternoon. The 00Z GFS,
TTU WRF and HRRR models indicate this potential. Carrying a slight
chance PoP for the area southeast of a Sonora to Eden to Lake
Brownwood line. Have a lingering slight chance PoP this evening
until 9 PM for nearly the same area. This convection will be
diurnally driven and dissipate by sunset, with clear to partly
cloudy skies expected overnight.
The 850mb temperatures increase only slightly today, mainly across
the western part of our area. With this indication and an
anticipated increase in cloud cover, going with highs about the
same as yesterday across our eastern and central counties, and
around a degree warmer in our western counties. Lows tonight are
expected to be mostly in the upper 60s.
19
.LONG TERM...
(Tuesday through Sunday)
The subtropical ridge axis currently runs in a general north-south
orientation along the front range, but will flatten over the
next few days as the large trough over the Great Basin ejects
shortwave energy over the crest of the ridge. Despite unimpressive
500 mb heights of 591-594 dam, a strong thermal ridge will reside
in the 850-700 mb layer, pushing temperatures well into the 90s
areawide, potentially reaching triple digits later this week. Min
temps will increase as well, with mid 70s anticipated by Thursday
morning. The general pattern will be an afternoon cumulus field
with clearing skies during the evening and overnight hours. Rain
chances will remain minimal due to the presence of the ridge and
dearth of deep moisture. That said, if any precipitation does
occur Tuesday through Thursday, it would more than likely be on
Tuesday afternoon.
The ECMWF and GEM are bringing a cold front south on Friday,
stalling the boundary in the vicinity of the Red River. The GFS,
however, maintains southerly flow well into the central plains. If
this boundary does verify, we`ll likely have to consider at
least a mention of isolated showers and thunderstorms Friday and
Saturday afternoon, despite the ridge being overhead. That said,
the juxtaposition of the front and the ridge appears unlikely.
Otherwise, expect the hot and generally dry conditions to
continue.
As we move through the weekend, both the GFS and ECMWF and ECMWF
are hinting that a TUTT low will develop and move across the
western Gulf of Mexico into south TX. With the upper-level ridge
centered over the region, this TUTT is likely to remain well to
our south, generally to far away to have much of an effect. If the
ridge is a bit weaker, this feature could yield isolated
convection Sunday into Monday. However, at this time, confidence is
far too low to include a mention in the forecast.
Johnson
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 92 69 94 73 97 / 5 10 5 5 5
San Angelo 93 68 95 71 98 / 5 10 5 5 5
Junction 92 69 94 72 96 / 20 20 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
19/25
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1138 PM CDT SUN AUG 3 2014
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
&&
.AVIATION...
MODELS STILL HAVING TROUBLE WITH THE GENERAL PATTERN AND AVAILABLE
MOISTURE. THE RAP PERFORMED WELL LAST NIGHT AND IS A BIT
AGGRESSIVE WITH RAIN TONIGHT BUT OVERALL IS DOING OK. LEANED
TOWARD THE RAP THROUGH 12Z AND THE GFS THEREAFTER. FCST SOUNDINGS
KEEP MSTR LEVELS BETWEEN 1.5 AND 1.7 INCHES. WILL CARRY VCSH ALONG
THE COAST THROUGH 12Z AND MIGHT NEED A VCSH FOR INLAND SITES LATE
MON AFTN. WINDS WILL REMAIN LIGHT FOR MUCH OF THE TAF PERIOD WITH
A BRIEF UPTICK IN SE WINDS ALONG THE COAST ON MON AFTN. 43
&&
.PREV DISCUSSION... /ISSUED 948 PM CDT SUN AUG 3 2014/
UPDATE...
SEE DISCUSSION FOR EVENING UPDATE.
DISCUSSION...
SURFACE LOW PRESSURE DID NOT MOVE AS FAR TO THE WEST AS EXPECTED
TODAY WHICH HELPED TO KEEP ALMOST THE ENTIRE AREA DRY THIS
AFTERNOON. THE LOW PRESSURE IS EXPECTED TO WASH OUT TOMORROW OFF
THE COAST NEAR THE LA/TX BORDER. HIGH RES MODELS AGAIN SHOW
ANOTHER DAY WITH MODERATE COVERAGE THANKS TO THE SURFACE LOW. AM
SKEPTICAL ABOUT THIS SOLUTION THOUGH AS GLOBAL MODELS AREN`T AS
AGGRESSIVE WITH POPS. THE UPPER LEVELS ALSO REMAIN UNFAVORABLE. AT
250MB A BROAD TROUGH AXIS REMAINS TO OUR EAST PUTTING THE AREA IN
THE CONVERGENT REGION OF THE AXIS. THERE IS ALSO A WEAK JET
STREAK AT 250 WITH SOUTHEAST TEXAS IN THE RFQ OR CONVERGENT
REGION. WE WILL ALSO CONTINUE THE GRADUAL WARM UP TOMORROW WITH
HIGH TEMPERATURES IN THE LOW 90S. GIVEN 850 TEMPERATURES HAVE
RAISED HIGH TEMPS BY A DEGREE OR TWO ACROSS THE AREA. HAVE ALSO
DONE THE SAME TO THE LOW TEMPERATURES AS THE AIR MASS CONTINUES TO
MODERATE. NO OTHER CHANGES WERE MADE AT THIS TIME. 23
PREV DISCUSSION... /ISSUED 318 PM CDT SUN AUG 3 2014/
DISCUSSION...
FINALLY STARTING TO SEE SOME DEVELOPMENT OVER OUR NRN ZONES IN RE-
LATION TO THE LOW. AREAL COVERAGE OF THIS ACTIVITY SHOULD CONTINUE
TO INCREASE ACROSS THE REGION THROUGH THIS EVENING. THIS PESKY LOW
PROGGED TO STICK AROUND THROUGH TOMORROW...ALONG WITH THE SCT RAIN
CHANCES FOR SE TX. HOWEVER WILL BE INTERESTING TO SEE IF THAT MORE
ORGANIZED PCPN THAT HAS REMAINED WELL TO THE EAST OF THE CWA TODAY
WILL TRANSLATE AND AFFECT SE TX TOMORROW.
OTHERWISE NOT A LOT OF CHANGE WITH THE REST OF THE FORECAST AS THE
UPPER RIDGE TRIES TO BUILD BACK OVER THE AREA FROM THE WEST DURING
THE MIDDLE PART OF THE WEEK. WARMER (NEAR NORMAL) TEMPS SET TO RE-
TURN BY TUE/WEDS AS RAIN CHCS ALSO RETURN TO THE MORE USUAL MAINLY
DAYTIME HEATING DRIVEN VARIETY. OF NOTE IN THE EXTENDED MODELS...A
HINT OF A DEVELOPING SHEAR AXIS/WEAKNESS IN THE UPPER RIDGE ACROSS
THE REGION FOR THE LATTER PART OF THE WEEK. THIS COULD LEAD TO IN-
CREASED POPS IF IT DOES VERIFY. 41
MARINE...
A WEAK PRESSURE GRADIENT OVER THE WATERS WILL CORRESPOND TO LIGHT
WINDS...MAINLY 10 KNOTS OR LESS...TONIGHT AND MOST OF MONDAY. THE
GRADIENT WILL INCREASE SOMEWHAT TOWARD MID WEEK...AS HIGH PRESSURE
BUILDS OVER THE GULF...WITH SOUTHEAST TO SOUTHERLY FLOW GETTING INTO
THE 10 TO 15 KNOT RANGE. 46
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 73 92 73 94 74 / 20 30 10 20 10
HOUSTON (IAH) 74 91 74 94 75 / 20 30 10 20 10
GALVESTON (GLS) 80 90 79 90 80 / 20 30 10 20 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...23
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
159 PM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 140 PM EDT MONDAY...
FOG IS NOT AN ISSUE ANYMORE TODAY. HOWEVER...THE SAME MOISTURE
RESPONSIBLE FOR THE FOG...IS NOW BEING LIFTED THERMALLY DURING THE
HEATING OF THE DAY AND RESULTING IN CUMULUS CLOUDS ALIGNED
PARALLEL TO THE MOUNTAIN RIDGES. THE FORECAST STILL WILL REFLECT
THE POTENTIAL FOR SOME ISOLATED SHOWERS OR STORMS THIS AFTERNOON.
LATEST MESOSCALE MODELS OFFER PARTS OF SOUTHEAST WEST
VIRGINIA...THE NORTHERN MOUNTAINS OF NORTH CAROLINA INTO PARTS OF
THE MOUNTAIN EMPIRE REGION OF SOUTHWEST VIRGINIA...AND PARTS OF
SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA AS THE MOST LIKELY REGIONS FOR THIS ISOLATED CONVECTION
TO FIRE. THIS DIFFERS VERY LITTLE FROM OUR PREVIOUS FORECAST AND
SO ONLY MINOR TWEAKS IN THIS AREAL DEFINITION HAVE BEEN MADE.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
TO MATCH THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
AFTERNOON. BUMPED UP FORECAST HIGH TEMPERATURES FOR A FEW
LOCATIONS IN THE EAST BY A DEGREE OR TWO.
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 150 PM EDT MONDAY...
MAINLY LOW END VFR CUMULUS FIELD HAS DEVELOPED ACROSS THE REGION
THIS AFTERNOON. A FEW POCKETS STILL MAY BE IN THE MVFR RANGE...BUT
SHOULD NOT BE FOR MUCH LONGER AS SURFACE TEMPERATURES RISE...AND
THUS THE LEVEL OF FREE CONVECTION. ISOLATED SHOWERS OR STORMS ARE
POSSIBLE LATE THIS AFTERNOON ALONG AN EAST OF A LINE FROM KLWB-
KBLF....BETWEEN KTNB AND KHLX...AND ALONG AND NEAR A KDAN-KFVX
LINE. ANY DEVELOPMENT IS NOT EXPECTED TO LAST MUCH LONGER THAN
SUNSET.
OVERNIGHT...MOUNTAIN VALLEY AND RIVER VALLEY FOG IS EXPECTED TO
REDEVELOP COMPARABLE TO WHAT OCCURRED THIS MORNING. A MIX OF
IFR/MVFR IS EXPECTED AFTER ROUGHLY 06Z/2AM TUESDAY AND LAST
THROUGH ROUGHLY 13Z/9AM TUESDAY.
VFR CONDITIONS ARE EXPECTED THROUGH THE MORNING AFTER THE FOG
MIXES OUT...BUT SOME LOCATIONS MAY DEVELOP A BRIEF MVFR CIG WHILE
TEMPERATURES WARM...AND EVENTUALLY LOW END VFR IS EXPECTED.
EXTENDED AVIATION FORECAST....
MONDAY NIGHT THROUGH TUESDAY NIGHT...THE AREA WILL REMAIN WITH AN
UPPER TROUGH AXIS. ISOLATED...DAYTIME SHOWERS OR STORMS WILL BE
POSSIBLE ON MONDAY. BOTH NIGHTS...MOUNTAIN AND RIVER VALLEY FOG
WILL AGAIN BE POSSIBLE.
A COLD FRONT WILL APPROACH THE REGION ON WEDNESDAY. LOOK FOR
GREATER COVERAGE OF SHOWERS AND STORMS...ESPECIALLY IN THE WEST
AND NORTH. WEDNESDAY NIGHT...A GREATER PORTION OF THE AREA MAY
HAVE SUB-VFR CONDITIONS WHERE RAINS FALLS DURING THE DAY
WEDNESDAY.
THE FRONT WILL SETTLE SOUTH OF THE AREA THURSDAY INTO FRIDAY WITH
HIGH PRESSURE BUILDING IN BEHIND IT. THE BEST CHANCE OF ANY
ADDITIONAL PRECIPITATION WILL BE ACROSS THE SOUTHERN PORTION OF
THE REGION.
ON SATURDAY...A WAVE WILL MOVE EASTWARD ALONG THE FRONT AND BUCKLE
THE FRONT NORTH BACK INTO THE AREA...AND THUS BRING A RETURN TO A
GREATER COVERAGE OF SHOWERS AND STORMS TO THE AREA.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...DS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1245 PM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 140 PM EDT MONDAY...
FOG IS NOT AN ISSUE ANYMORE TODAY. HOWEVER...THE SAME MOISTURE
RESPONSIBLE FOR THE FOG...IS NOW BEING LIFTED THERMALLY DURING THE
HEATING OF THE DAY AND RESULTING IN CUMULUS CLOUDS ALIGNED
PARALLEL TO THE MOUNTAIN RIDGES. THE FORECAST STILL WILL REFLECT
THE POTENTIAL FOR SOME ISOLATED SHOWERS OR STORMS THIS AFTERNOON.
LATEST MESOSCALE MODELS OFFER PARTS OF SOUTHEAST WEST
VIRGINIA...THE NORTHERN MOUNTAINS OF NORTH CAROLINA INTO PARTS OF
THE MOUNTAIN EMPIRE REGION OF SOUTHWEST VIRGINIA...AND PARTS OF
SOUTHSIDE VIRGINIA AND NEIGHBORING PORTIONS OF NORTH CENTRAL NORTH
CAROLINA AS THE MOST LIKELY REGIONS FOR THIS ISOLATED CONVECTION
TO FIRE. THIS DIFFERS VERY LITTLE FROM OUR PREVIOUS FORECAST AND
SO ONLY MINOR TWEAKS IN THIS AREAL DEFINITION HAVE BEEN MADE.
HAVE ADJUSTED HOURLY TEMPERATURE...DEW POINT...SKY COVER AND WIND
TO MATCH THE LATEST OBSERVATIONS AND EXPECTED TRENDS THROUGH THE
AFTERNOON. BUMPED UP FORECAST HIGH TEMPERATURES FOR A FEW
LOCATIONS IN THE EAST BY A DEGREE OR TWO.
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
942 AM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM EDT MONDAY...
FOG WILL CONTINUE TO ERODE THIS MORNING. MORNING SOUNDINGS SHOWING
ONLY A NARROW REGION ON MOISTURE AT OR BELOW 850 MB. ABOVE
THAT...VERY DRY AIR WAS IN PLACE. EXPECT MIXING TO CONTINUE TO
TAKE PLACE THIS MORNING WITH ANY REMAINING FOG DISSIPATED BY 1100
AM. REMAINDER OF THE FORECAST STILL LOOKS ON TRACK BASED UPON THE
EARLIER DISCUSSION.
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
738 AM EDT MON AUG 4 2014
.SYNOPSIS...
HIGH PRESSURE WILL BE OVER THE REGION TODAY. A COLD FRONT IS
EXPECTED TO DROP SOUTH THROUGH THE MID ATLANTIC REGION BY
THURSDAY. LOW PRESSURE WILL MOVE ALONG THE FRONT...THROUGH THE
SOUTHEAST UNITED STATES THIS WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 445 AM EDT MONDAY...
ONLY A FEW SPRINKLES LEFT IN STOKES AND HENRY COUNTIES EARLY THIS
MORNING AS THE PRECIPITATION CONTINUED TO DISSIPATE. PATCHY FOG
HAD DEVELOPED ACROSS MUCH OF THE FORECAST AREA EARLY THIS MORNING
BUT THE MORE SIGNIFICANT REDUCTIONS IN VISIBILITY WERE IN THE
EXTREME EASTERN PART OF THE COUNTY WARNING AREA.
FORECAST SOUNDINGS SHOWED THE LOWEST 5000 FEET OF THE ATMOSPHERE
STILL MOIST WITH MUCH DRIER AIR THROUGH MID LEVELS. EXPECT FOG TO
MIX OUT SHORTLY AFTER SUNRISE IN THE MOUNTAINS. IT MAY TAKE A BIT
LONGER EAST OF THE BLUE RIDGE WHERE THERE IS A LAYER OF LOW CLOUDS
OVER THE PIEDMONT.
SURFACE THROUGH 850 MB WINDS BECOME EAST TODAY. THIS MAY GENERATE
ENOUGH CONVERGENCE ALONG THE BLUE RIDGE FOR ISOLATED SHOWERS AND
THUNDERSTORMS...ALTHOUGH AIR MASS IS NOT PARTICULARLY UNSTABLE AND
MOISTURE IS NOT DEEP. A SHORT WAVE CROSSING THROUGH THE TENNESSEE
VALLEY MAY ALSO TRIGGER ISOLATED SHOWERS AND THUNDERSTORMS.
HIGHER DEW POINTS AND LARGER PRECIPITABLE WATER VALUES ARE JUST
SOUTHEAST OF THE FORECAST AREA. LOCAL WRF AND LATEST RAP GUIDANCE
BULGE THIS DEEPER MOISTURE BACK INTO THE SOUTHEAST COUNTY WARNING
AREA THIS AFTERNOON. BUT WITH LITTLE FORCING...AREAL COVERAGE OF
PRECIPITATION IS EXPECTED TO BE LIMITED.
MOST LOCATIONS WILL HAVE ENOUGH SUNSHINE TODAY TO BRING
TEMPERATURES INTO THE 80S. STAYED CLOSE TO THE WARMER GUIDANCE FOR
MAXIMUM TEMPERATURES. TOOK A BLEND OF MET/MAV GUIDANCE FOR LOWS
TONIGHT.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 314 AM EDT MONDAY...
A BROAD UPPER LEVEL TROUGH WILL TAKE RESIDENCE OVER THE MISSISSIPPI
VALLEY TO THE EAST COAST TUESDAY. THIS TROUGH WILL BE RESPONSIBLE
FOR KICKING BERTHA FARTHER OUT INTO THE ATLANTIC. AS BERTHA TURNS
NORTHEAST ON TUESDAY...DRY STABLE AIR WILL KEEP MOST OF THE FORECAST
AREA DRY. A FEW SHOWERS MAY DEVELOP FROM THE SOUTHERN SHENANDOAH
VALLEY NORTHWARD...IF PASSING WEAK SHORT WAVES CAN TAP INTO ANY
AVAILABLE MOISTURE. IF SHOWERS WOULD DEVELOP...THEY SHOULD BE SHORT
LIVED AND FADE DURING THE EARLY EVENING. TEMPERATURES TUESDAY
AFTERNOON WILL BE IN THE 80S AREAWIDE WITH DEW POINTS IN THE U50S
WEST TO THE M60S ACROSS THE PIEDMONT.
ON WEDNESDAY...THE UPPER LEVEL TROUGH FLATTENS OVER THE SOUTH. THIS
TROUGH WILL BEGIN TO ALLOW DISTURBANCES TO TRACK FROM THE MID WEST
TO THE SOUTH-CENTRAL APPALACHIANS. MODELS HAVE BACK OFF ON SHOWER
ACTIVITY OVER THE AREA FOR WEDNESDAY. WITH A LEE TROUGH ALONG THE
COAST...MAINLY DIURNAL CONVECTION IS EXPECTED ACROSS THE MOUNTAINS
WEDNESDAY AFTERNOON. WITH DEEP NORTHWESTERLY FLOW...SHOWERS MAY NOT
MOVE EAST OF THE BLUE RIDGE UNTIL WEDNESDAY EVENING WHEN FLOW
WEAKENS. BULK OF THE CONVECTION WEDNESDAY WILL BE ALONG A COLD FRONT
WHICH MODELS ARE NOW KEEPING TO THE NORTH UNTIL THURSDAY.
TEMPERATURES WEDNESDAY WILL BE A FEW DEGREES WARMER THAN
TUESDAY...AS THE AREA WILL BE AHEAD OF A COLD FRONT.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM EDT MONDAY...
SATELLITE PICTURES AND SURFACE OBSERVATIONS SHOWED AREAS OF MVFR
TO IFR FOG IN THE NEW AND GREENBRIER RIVER VALLEYS AND SOME FOG
AND STRATUS IN THE PIEDMONT OF VIRGINIA AND NORTH CAROLINA. BUFKIT
SOUNDINGS INDICATED THE LAYER OF MOISTURE WAS SHALLOW. EXPECTING
THE FOG TO DISSIPATE BY MID MORNING. HIGH CONFIDENCE THAT
CONDITIONS WILL BE VFR BY 14Z/10AM.
MOSTLY LIGHT/VARIABLE THROUGH TONIGHT. THERE IS A LOW PROBABILITY
OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON...AS EAST LOW LEVEL
WINDS CREATE SOME CONVERGENCE NEAR THE BLUE RIDGE. THE CHANCE IS
TOO LOW TO INCLUDE IN ANY OF THE TAFS AT THIS TIME.
FOG IS EXPECTED TO DEVELOP AGAIN OVERNIGHT IN TYPICAL LOCATIONS.
MODERATE TO HIGH CONFIDENCE THAT VISIBILITY WILL LOWER TO AT LEAST
MVFR AT KLYH/KBCB AND KLWB AFTER MIDNIGHT.
EXTENDED AVIATION DISCUSSION...
A COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH SHOWER AND SOME THUNDERSTORMS IN ASSOCIATION WITH THE COLD
FRONT. LIKEWISE...MORE OVERNIGHT SUB- VFR CONDITIONS ARE LIKELY
WITH BOUNDARY LAYER MOISTURE TRAPPED UNDER THE NOCTURNAL
INVERSION. IF THERE IS LIMITED MOVEMENT OF THE FRONT BY
FRIDAY...EXPECT SIMILAR CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...RCS
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
200 AM EDT MON AUG 4 2014
.SYNOPSIS...
AN UPPER TROUGH RESIDES OVER THE REGION THROUGH TUESDAY...BUT THE
OVERALL FLOW TURNS MORE TO THE WEST. MEANWHILE...BERTHA STAYS WELL
OFFSHORE HEADING INTO THE WORKWEEK. A COLD FRONT IS EXPECTED TO
DROP TO THE MID ATLANTIC AND SOUTHERN APPALACHIANS BY THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT SUNDAY...
AN UPPER LOW PRESSURE WAS CENTERED OVER WESTERN PA...WITH ITS
ASSOCIATED TROUGH AXIS TRAILING SOUTH INTO THE CENTRAL APPALACHIANS.
A FRONTAL BOUNDARY WAS STALLED ALONG THE COASTS OF NC AND SC. THE
WEDGE OF HIGH PRESSURE ALONG THE LEE OF THE APPALACHIANS HAS
ERODED.
FOR THE OVERNIGHT...WILL HAVE TO MONITOR THE UPPER TROUGH AXIS FOR
POTENTIAL SHOWER DEVELOPMENT. AS OF 10PM THE TROF AXIS WAS
POSITIONED NR THE BLUE RIDGE...WITH A NARROW AXIS OF MOISTURE
CONVERGENCE PRESENT FROM THE DC AREA IN NORTHERN VA...TO NEAR
GREER SOUTH CAROLINA...PASSING THROUGH OUR CWA WAY OF A
LYH...MTV...MWK LINE. WITHIN THIS NARROW CORRIDOR...SHOWERS ARE
POSSIBLE. ATTM THE GREATEST COVERAGE WAS NORTH OF OUR CWA FROM
CHO-DCA. OTHER SHOWERS...MORE ISOLATED IN NATURE...WERE OCCURRING
FROM MOUNT AIRY NC...MWK...TO HICKORY...HKY. THE HRRR MODEL
MAINTAINS AREA OF LIFT VCNTY OF THE NW PIEDMONT OF NC THROUGH
ABOUT 06Z/2AM...SO LIKEWISE MAINTAINED THE HIGHEST POPS WITHIN
OUR CWA TO THIS CORRIDOR THROUGH MIDNIGHT.
AFTER MIDNIGHT...CONVECTION IS EXPECTED TO WANE. PATCHY FOG IS
THEN EXPECTED TO DEVELOP WITH A RETURN OF LOW LEVEL STRATUS
CLOUDS IN AND AROUND THE AREAS OF FOG. LOWS TONIGHT WILL RANGE
FROM THE MID TO UPPER 50S ACROSS THE MOUNTAINS WITH LOW TO MID 60S
ACROSS THE PIEDMONT.
ON MONDAY...MODELS DIFFER ON THE IMPACT SURFACE LOW PRESSURE THAT
FORMS ALONG THE STALLED FRONT ALONG THE COAST OF THE CAROLINAS
IMPACTS OUR WEATHER AS IT MOVES NORTHWARD ALONG THE FRONT. THE NAM
IS THE MOST AGGRESSIVE IN BRINGING A SUBSTANTIAL SLUG OF MOISTURE
INTO AT LEAST THE SOUTHEAST PART OF THE AREA BY TOMORROW AFTERNOON.
THIS IS A SUBSTANTIAL AMOUNT COMPARED TO GFS/ECWMF/CANADIAN
SOLUTIONS WHICH KEEP THE ACTIVITY MORE TO OUR EAST. THE NAM HAS BEEN
OVERDOING PRECIPITATION AMOUNTS AND HAS BEEN OFF ON THE BULLSEYE OF
PRECIPITATION CENTERS THAT PAST FEW DAYS...AND LIMITED CREDENCE WILL
BE GIVEN TO ITS LATEST SOLUTIONS. THE DRIER GFS/ECMWF/CANADIAN
SOLUTIONS WILL CONTINUE TO BE FAVORED IN OUR FORECAST. THIS DOES NOT
MEAN NO PRECIPITATION...BUT RATHER MORE OF ISOLATED DAYTIME
CONVECTION MAINLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE
WHERE LOW LEVEL TRAJECTORIES WILL ADD AN ELEMENT OF UPSLOPE. FOR
HIGH TEMPERATURES...FAVORING A SOLUTION THAT IS CLOSER TO THE MILDER
MOSGUIDE GRIDS AS COMPARED TO THE COOLER ADJMET. BELIEVE THE LATTER
IS BEING IMPACTED BY THE GREATER ABUNDANCE OF PRECIPITATION IT WANTS
TO GENERATE OVER THE REGION TOMORROW AFTERNOON...ESPECIALLY IN THE
SOUTHEAST PART OF THE AREA.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
KEEPING THIS FORECAST CLOSER TO THE 00Z ECMWF SOLUTION WITH THE 12Z
GFS NOT TOO FAR OUT OF TOLERANCE WITH THE ECMWF. STILL LOOKING AT
TROUGH SITUATED OVER THE EAST...BUT EXPECTING RISING HEIGHTS AT 5H
INTO WEDNESDAY WITH INCREASED WESTERLY FLOW ALOFT AHEAD OF THE NEXT
FRONT.
FOR SHOWERS AND STORMS...EXPECT ISOLATED/SCATTERED ACROSS THE
MOUNTAINS AND FOOTHILLS TUESDAY WITHIN SFC CONVERGENT FIELD...WHILE
DEPARTING BERTHA OUT WELL EAST OF HATTERAS SHIFTS NE AWAY FROM LAND.
DIURNAL CONVECTION MAINLY AGAIN WEDNESDAY ALTHOUGH MAY LESS WITH
DOWNSLOPE INCREASING ALOFT. WILL HAVE SLIGHT TO LOW CHANCE SHRA/TSRA
ALONG AND WEST OF THE BLUE RIDGE WEDNESDAY AFTERNOON.
HIGHS WILL START WORKING BACK TO AT OR ABOVE NORMAL EAST OF THE
MOUNTAINS TUE-WED WITH HIGHS IN THE UPPER 80S/LOWER 90S...WHILE THE
MOUNTAINS WILL STAY CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH
LOWER 80S...THOUGH SOME MID 80S IN THE VALLEYS OF THE I-81 CORRIDOR.
HIGH LEVEL CLOUD COVER AHEAD OF THE FRONT WEDNESDAY MAY ROLL IN
FASTER THAN LATE AFTERNOON AS DEPICTED OFF THE ECWMF...WHICH
COULD BRING HIGHS A LITTLE LOWER IN THE MOUNTAINS/FOOTHILLS...BUT
STILL VERY WARM.
LOWS WILL BE CLOSE TO NORMAL MON-TUE NIGHT WITH UPPER 50S/LOWER 60S
MOUNTAINS TO MID TO UPPER 60S EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 155 AM EDT MONDAY...
CLEAR SKIES AND LIGHT/CALM WINDS WILL LEAD TO FAVORABLE
RADIATIONAL COOLING TONIGHT. MVFR FOG HAD ALREADY DEVELOPED AT
KLWB/KBCB AND KLYH. MODERATE TO HIGH CONFIDENCE THAT VISIBILITY
WILL CONTINUE TO LOWER WITH LIFR CONDITIONS AT THESE LOCATIONS BY
09Z/5AM. A SHALLOW LAYER OF LOW LEVEL MOISTURE OVER CENTRAL AND
EASTERN VIRGINIA AND NORTH CAROLINA REMAINED EARLY THIS MORNING.
IFR STRATUS HAD FORMED AT KDAN. EXPECT STRATUS TO PERSIST AT KDAN
UNTIL AFTER MIXING BEGINS SHORTLY AFTER SUNRISE.
MOSTLY LIGHT/VARIABLE THROUGH THE TAF VALID PERIOD...ALTHOUGH
TENDENCY FOR NE WINDS EAST OF THE BLUE RIDGE IN RESPONSE TO
COASTAL TROUGH/FRONT AND NW WINDS WEST OF THE BLUE RIDGE IN
RESPONSE TO OHIO VALLEY HIGH PRESSURE.
EXTENDED AVIATION DISCUSSION...
ANOTHER BROAD UPPER TROUGH WILL BECOME POSITIONED ACROSS THE
EASTERN THIRD OF THE UNITED STATES BY EARLY NEXT WEEK. AN
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY. FOR AVIATION
CONCERNS...MONDAY INTO TUESDAY WILL HAVE LIMITED PRECIPITATION
CHANCES...ISOLATED AT BEST...BUT THE POTENTIAL FOR OVERNIGHT
PATCHY FOG AND LOW STRATUS IN THE MOUNTAIN AND RIVER VALLEYS.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH ONGOING SHOWER AND SOME THUNDERSTORM ACTIVITY IN ASSOCIATION
WITH THE COLD FRONT. LIKEWISE...A GREATER ABUNDANCE OF LINGERING
OVERNIGHT SUB-VFR CONDITIONS ARE LIKELY WITH BOUNDARY LAYER
MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION. IF THERE IS
LIMITED MOVEMENT OF THE FRONT BY FRIDAY...EXPECT SIMILAR
CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...DS/PM
SHORT TERM...WP
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
159 AM EDT MON AUG 4 2014
.SYNOPSIS...
AN UPPER TROUGH RESIDES OVER THE REGION THROUGH TUESDAY...BUT THE
OVERALL FLOW TURNS MORE TO THE WEST. MEANWHILE...BERTHA STAYS WELL
OFFSHORE HEADING INTO THE WORKWEEK. A COLD FRONT IS EXPECTED TO
DROP TO THE MID ATLANTIC AND SOUTHERN APPALACHIANS BY THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1030 PM EDT SUNDAY...
AN UPPER LOW PRESSURE WAS CENTERED OVER WESTERN PA...WITH ITS
ASSOCIATED TROUGH AXIS TRAILING SOUTH INTO THE CENTRAL APPALACHIANS.
A FRONTAL BOUNDARY WAS STALLED ALONG THE COASTS OF NC AND SC. THE
WEDGE OF HIGH PRESSURE ALONG THE LEE OF THE APPALACHIANS HAS
ERODED.
FOR THE OVERNIGHT...WILL HAVE TO MONITOR THE UPPER TROUGH AXIS FOR
POTENTIAL SHOWER DEVELOPMENT. AS OF 10PM THE TROF AXIS WAS
POSITIONED NR THE BLUE RIDGE...WITH A NARROW AXIS OF MOISTURE
CONVERGENCE PRESENT FROM THE DC AREA IN NORTHERN VA...TO NEAR
GREER SOUTH CAROLINA...PASSING THROUGH OUR CWA WAY OF A
LYH...MTV...MWK LINE. WITHIN THIS NARROW CORRIDOR...SHOWERS ARE
POSSIBLE. ATTM THE GREATEST COVERAGE WAS NORTH OF OUR CWA FROM
CHO-DCA. OTHER SHOWERS...MORE ISOLATED IN NATURE...WERE OCCURRING
FROM MOUNT AIRY NC...MWK...TO HICKORY...HKY. THE HRRR MODEL
MAINTAINS AREA OF LIFT VCNTY OF THE NW PIEDMONT OF NC THROUGH
ABOUT 06Z/2AM...SO LIKEWISE MAINTAINED THE HIGHEST POPS WITHIN
OUR CWA TO THIS CORRIDOR THROUGH MIDNIGHT.
AFTER MIDNIGHT...CONVECTION IS EXPECTED TO WANE. PATCHY FOG IS
THEN EXPECTED TO DEVELOP WITH A RETURN OF LOW LEVEL STRATUS
CLOUDS IN AND AROUND THE AREAS OF FOG. LOWS TONIGHT WILL RANGE
FROM THE MID TO UPPER 50S ACROSS THE MOUNTAINS WITH LOW TO MID 60S
ACROSS THE PIEDMONT.
ON MONDAY...MODELS DIFFER ON THE IMPACT SURFACE LOW PRESSURE THAT
FORMS ALONG THE STALLED FRONT ALONG THE COAST OF THE CAROLINAS
IMPACTS OUR WEATHER AS IT MOVES NORTHWARD ALONG THE FRONT. THE NAM
IS THE MOST AGGRESSIVE IN BRINGING A SUBSTANTIAL SLUG OF MOISTURE
INTO AT LEAST THE SOUTHEAST PART OF THE AREA BY TOMORROW AFTERNOON.
THIS IS A SUBSTANTIAL AMOUNT COMPARED TO GFS/ECWMF/CANADIAN
SOLUTIONS WHICH KEEP THE ACTIVITY MORE TO OUR EAST. THE NAM HAS BEEN
OVERDOING PRECIPITATION AMOUNTS AND HAS BEEN OFF ON THE BULLSEYE OF
PRECIPITATION CENTERS THAT PAST FEW DAYS...AND LIMITED CREDENCE WILL
BE GIVEN TO ITS LATEST SOLUTIONS. THE DRIER GFS/ECMWF/CANADIAN
SOLUTIONS WILL CONTINUE TO BE FAVORED IN OUR FORECAST. THIS DOES NOT
MEAN NO PRECIPITATION...BUT RATHER MORE OF ISOLATED DAYTIME
CONVECTION MAINLY ALONG AND EAST OF THE CREST OF THE BLUE RIDGE
WHERE LOW LEVEL TRAJECTORIES WILL ADD AN ELEMENT OF UPSLOPE. FOR
HIGH TEMPERATURES...FAVORING A SOLUTION THAT IS CLOSER TO THE MILDER
MOSGUIDE GRIDS AS COMPARED TO THE COOLER ADJMET. BELIEVE THE LATTER
IS BEING IMPACTED BY THE GREATER ABUNDANCE OF PRECIPITATION IT WANTS
TO GENERATE OVER THE REGION TOMORROW AFTERNOON...ESPECIALLY IN THE
SOUTHEAST PART OF THE AREA.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 230 PM EDT SUNDAY...
KEEPING THIS FORECAST CLOSER TO THE 00Z ECMWF SOLUTION WITH THE 12Z
GFS NOT TOO FAR OUT OF TOLERANCE WITH THE ECMWF. STILL LOOKING AT
TROUGH SITUATED OVER THE EAST...BUT EXPECTING RISING HEIGHTS AT 5H
INTO WEDNESDAY WITH INCREASED WESTERLY FLOW ALOFT AHEAD OF THE NEXT
FRONT.
FOR SHOWERS AND STORMS...EXPECT ISOLATED/SCATTERED ACROSS THE
MOUNTAINS AND FOOTHILLS TUESDAY WITHIN SFC CONVERGENT FIELD...WHILE
DEPARTING BERTHA OUT WELL EAST OF HATTERAS SHIFTS NE AWAY FROM LAND.
DIURNAL CONVECTION MAINLY AGAIN WEDNESDAY ALTHOUGH MAY LESS WITH
DOWNSLOPE INCREASING ALOFT. WILL HAVE SLIGHT TO LOW CHANCE SHRA/TSRA
ALONG AND WEST OF THE BLUE RIDGE WEDNESDAY AFTERNOON.
HIGHS WILL START WORKING BACK TO AT OR ABOVE NORMAL EAST OF THE
MOUNTAINS TUE-WED WITH HIGHS IN THE UPPER 80S/LOWER 90S...WHILE THE
MOUNTAINS WILL STAY CLOSER TO NORMAL FOR THIS TIME OF YEAR WITH
LOWER 80S...THOUGH SOME MID 80S IN THE VALLEYS OF THE I-81 CORRIDOR.
HIGH LEVEL CLOUD COVER AHEAD OF THE FRONT WEDNESDAY MAY ROLL IN
FASTER THAN LATE AFTERNOON AS DEPICTED OFF THE ECWMF...WHICH
COULD BRING HIGHS A LITTLE LOWER IN THE MOUNTAINS/FOOTHILLS...BUT
STILL VERY WARM.
LOWS WILL BE CLOSE TO NORMAL MON-TUE NIGHT WITH UPPER 50S/LOWER 60S
MOUNTAINS TO MID TO UPPER 60S EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EDT SUNDAY...
COLD FRONT CROSSES THE REGION ON THURSDAY AND SLOWLY SAGS SOUTH OF
THE CWA BY FRIDAY. UNCERTAINTY EXISTS ON LOCATION OF A DISTURBANCE
EXPECTED FRIDAY NIGHT INTO THE WEEKEND. THE GFS HAS BEEN
INCONSISTENT FROM RUN TO RUN...WITH THE 12Z RUN BRINGING THE
DISTURBANCE FURTHER TO THE NORTH. AGREE WITH WPC WHO HAS BEEN
TRENDING TOWARD THE ECMWF SOLUTION...WHICH WOULD AFFECT MORE OF OUR
SOUTHERN CWA WITH SHOWERS AND THUNDERSTORMS. AT THE MOMENT GOING
WITH CHANCE POPS ACROSS THE SOUTHERN HALF OF THE CWA AND SLIGHT
CHANCE ACROSS THE NORTHERN HALF.
SURFACE HIGH ACROSS THE CENTRAL GREAT LAKES WILL SHIFT TOWARDS NY
FOR THE WEEKEND WHILE A WEAK LOW PRESSURE SYSTEM FORMS OFF THE
VA/NC COAST. THIS WILL PLACE THE REGION ONCE AGAIN UNDER A
COOLER EASTERLY WEDGE FLOW. CLOUDY CONDITIONS AND ANY PRECIP
ASSOCIATED WITH THE APPROACHING DISTURBANCE WILL HOLD SURFACE HIGH
TEMPS LOWER THROUGH THE PERIOD. EXPECT TEMPS TO BE 5-10 DEGREES
BELOW NORMAL WITH SATURDAY BEING THE COOLEST DAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 750 PM EDT SUNDAY...
CLEAR SKIES AND LIGHT/CALM WINDS WILL LEAD TO FAVORABLE
RADIATIONAL COOLING TONIGHT. MVFR FOG HAD ALREADY DEVELOPED AT
KLWB/KBCB AND KLYH. MODERATE TO HIGH CONFIDENCE THAT VISIBILITY
WILL CONTINUE TO LOWER WITH LIFR CONDITIONS AT THESE LOCATIONS BY
09Z/5AM. A SHALLOW LAYER OF LOW LEVEL MOISTURE OVER CENTRAL AND
EASTERN VIRGINIA AND NORTH CAROLINA REMAINED EARLY THIS MORNING.
IFR STRATUS HAD FORMED AT KDAN. EXPECT STRATUS TO PERSIST AT KDAN
UNTIL AFTER MIXING BEGINS SHORTLY AFTER SUNRISE.
MOSTLY LIGHT/VARIABLE THROUGH THE TAF VALID PERIOD...ALTHOUGH
TENDENCY FOR NE WINDS EAST OF THE BLUE RIDGE IN RESPONSE TO
COASTAL TROUGH/FRONT AND NW WINDS WEST OF THE BLUE RIDGE IN
RESPONSE TO OHIO VALLEY HIGH PRESSURE.
EXTENDED AVIATION DISCUSSION...
ANOTHER BROAD UPPER TROUGH WILL BECOME POSITIONED ACROSS THE
EASTERN THIRD OF THE UNITED STATES BY EARLY NEXT WEEK. AN
ASSOCIATED COLD FRONT WILL SWEEP THROUGH THE REGION WEDNESDAY INTO
THURSDAY. QUESTIONS REMAIN AS TO HOW FAR SOUTH OF THE REGION...IF
AT ALL...THE FRONT MAKES IT BY FRIDAY. FOR AVIATION
CONCERNS...MONDAY INTO TUESDAY WILL HAVE LIMITED PRECIPITATION
CHANCES...ISOLATED AT BEST...BUT THE POTENTIAL FOR OVERNIGHT
PATCHY FOG AND LOW STRATUS IN THE MOUNTAIN AND RIVER VALLEYS.
WEDNESDAY INTO THURSDAY ARE MORE LIKELY TO HAVE SUB-VFR CONDITIONS
WITH ONGOING SHOWER AND SOME THUNDERSTORM ACTIVITY IN ASSOCIATION
WITH THE COLD FRONT. LIKEWISE...A GREATER ABUNDANCE OF LINGERING
OVERNIGHT SUB-VFR CONDITIONS ARE LIKELY WITH BOUNDARY LAYER
MOISTURE TRAPPED UNDER THE NOCTURNAL INVERSION. IF THERE IS
LIMITED MOVEMENT OF THE FRONT BY FRIDAY...EXPECT SIMILAR
CONDITIONS AS COMPARED TO THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...DS/PM
SHORT TERM...WP
LONG TERM...CF
AVIATION...AMS/RAB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
855 PM MDT TUE AUG 5 2014
.UPDATE...
ISSUED AT 855 PM MDT TUE AUG 5 2014
JUST UPDATED FORECAST TO EXTEND SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS INTO THE LATE EVENING HOURS FOR SOME AREAS...MAINLY
ACROSS THE NORTHERN ZONES WHERE PASSING SHORTWAVE ENERGY IN ZONE
OF LINGERING DEEPER MOISTURE IS LIKELY TO KEEP CONVECTION GOING
INTO THE LATE EVENING. GREATEST CONCENTRATION OF STORMS EXPECTED
TO BE ACROSS PORTIONS OF CONVERSE COUNTY THROUGH 11 PM WHERE
LOCALLY HEAVY RAINS WILL BE POSSIBLE IN SOME LOCATIONS WEST OF
BILL. OTHERWISE...EXPECT MOST OF THE THUNDERSTORM ACTIVITY TO
DIMINISH AFTER MIDNIGHT WITH UPSLOPE BOUNDARY LAYER FLOW ACROSS
THE NORTHERN PORTIONS OF THE NEBRASKA PANHANDLE EXPECTED TO RESULT
IN A ROUND OF LOW CLOUDS AND SOME FOG DURING THE EARLY TO MID
MORNING HOURS. REST OF FORECAST ON TRACK.
02/GARMON
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT)
ISSUED AT 230 PM MDT TUE AUG 5 2014
WATER VAPOR IMAGERY STILL SHOWING MONSOONAL MOISTURE OVER THE
STATE OF WYOMING THIS AFTERNOON...BUT A LARGE DRY SLOT CONTINUES
TO EDGE NORTHEAST FROM UTAH AND SOUTHWESTERN COLORADO. PLUME OF
DEEPEST MOISTURE IS NOW OFF TO OUR EAST IN CENTRAL NEBRASKA AND
SOUTH DAKOTA. AT THE SURFACE...THE FRONTAL BOUNDARY THAT MOVED
INTO THE AREA LAST NIGHT AND THIS MORNING IS LAYING UP AGAINST THE
LARAMIE RANGE AND IS THE FOCUS FOR SHOWERS AND THUNDERSTORM
DEVELOPMENT. MOSAIC RADAR SHOWS CONVECTION CONCENTRATED EAST OF
THE LARAMIE RANGE AND ACROSS THE SOUTHERN PANHANDLE SO FAR TODAY.
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ACROSS SOUTHWESTERN
WYOMING AND NORTHWESTERN COLORADO CONTINUE TO MOVE NORTHEAST. SOME
OF THIS ACTIVITY WILL MAKE ITS WAY INTO CARBON AND ALBANY COUNTIES
THIS AFTERNOON IF IT HOLDS TOGETHER.
MINOR WAVE SEEN ON WATER VAPOR IMAGERY WILL TRACK FROM SOUTHWEST
WYOMING THROUGH CENTRAL WYOMING AND THEN EAST IN SOUTH DAKOTA
THROUGH THE AFTERNOON. THIS SHOULD AID IN INCREASING PRECIP
COVERAGE. LATEST HRRR FORECAST SHOWS BANDS OF SHOWERS/TSTMS
DEVELOPING OVER THE LARAMIE RANGE...THEN MOVING EAST NORTHEAST
INTO THE PANHANDLE THIS AFTERNOON. COULD SEE A MARGINALLY SEVERE
THUNDERSTORM EVENT ACROSS THE NORTHERN PANHANDLE TODAY WITH
SBCAPES AROUND 1200-1400 J/KG AROUND ALLIANCE AND CHADRON. THEY
ARE STILL CAPPED PRETTY GOOD THOUGH SO FAR. NAM SOUNDINGS SHOWING
THIS CAP BREAKING AROUND 21Z OR SO AND HRRR SHOWING A PRETTY
STRONG CELL DEVELOPING SOUTH OF MONTROSE IN SIOUX COUNTY OUT IN
THE NORTHERN PANHANDLE BY LATE AFTERNOON.
WITH THE SHORTWAVE MOVING THROUGH THE AREA THIS EVENING...THE
FRONTAL SYSTEM BEGINS TO BE LIFTED NORTHEAST. SHOWERS AND
THUNDERSTORMS SHOULD DECREASE IN COVERAGE ACROSS EXTREME SOUTHEAST
WYOMING AND THE SOUTHERN PANHANDLE THIS EVENING.
SHOWERS AND THUNDERSTORMS RETURN WEDNESDAY AFTERNOON WITH THE
ECMWF AND NAM/WRF MODELS IN GOOD AGREEMENT. BEST AREA FOR
CONVECTION LOOKS TO BE EAST OF THE LARAMIE RANGE AND THE PANHANDLE
BY MID AFTERNOON PERSISTING INTO MID EVENING BEFORE TAPERING OFF
WITH LOSS OF DAYTIME HEATING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 1159 AM MDT TUE AUG 5 2014
THURSDAY...EVEN THOUGH RIDGING ALOFT WILL LIMIT AREAL THUNDERSTORM
COVERAGE...LOOKS LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR LATE DAY
ISOLATED TO SCATTERED THUNDERSTORMS...MOST NUMEROUS FROM SIDNEY TO
CHADRON WHERE UPWARD VERTICAL MOTION WILL BE MOST PRONOUNCED.
FRIDAY...INCREASE IN LOW AND MID LEVEL MOISTURE ALONG WITH A WELL
PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS WILL AID IN AT LEAST
SCATTERED AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25.
SATURDAY...AS THE ATMOSPHERE DRIES SOMEWHAT FROM FRIDAY...WE EXPECT
A CORRESPONDING DECREASE INT THE AREAL THUNDERSTORM COVERAGE. BEST
CHANCES FOR STORMS WILL BE ALONG WESTERN NEBRASKA WHERE A LOW LEVEL
CONVERGENCE AXIS IS PROGGED TO DEVELOP.
SUNDAY/TUESDAY...ISOLATED LATE DAY THUNDERSTORMS WILL OCCUR WITH
ADEQUATE LOW AND MID LEVEL MOISTURE AND WEAK LOW LEVEL UPSLOPE EAST
WINDS.
MONDAY...MINIMAL THUNDERSTORM CHANCES WITH RIDGING ALOFT AND LIMITED
LOW AND MID LEVEL MOISTURE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 600 PM MDT TUE AUG 5 2014
SCATTERED THUNDERSTORMS CURRENTLY MOVING EAST INTO THE NEBRASKA
PANHANDLE WILL CONTINUE TO BE IN VICINITY OF
CHADRON...SCOTTSBLUFF...ALLIANCE AND SIDNEY THROUGH 03Z BEFORE
DIMINISHING. LOOKING WEST...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE IN THE VICINITY OF RAWLINS...LARAMIE AND
CHEYENNE UNTIL 02Z BEFORE DIMINISHING. FOR THE OVERNIGHT PERIOD
INTO WEDNESDAY MORNING...LATEST HIGH RESOLUTION RAPID REFRESH
MODEL RUN STILL DEPICTING IFR CEILINGS FROM STRATUS WORKING
SOUTHEAST INTO THE CHADRON...ALLIANCE...AND SCOTTSBLUFF AREAS
AFTER MIDNIGHT IN NORTHEASTERLY UPSLOPE FLOW...AND WE HAVE KEPT IFR
CEILINGS PREVAILING IN THE FORECAST FOR MUCH OF OUR WESTERN
NEBRASKA PANHANDLE SITES BETWEEN 09Z AND 16Z. OTHERWISE...EXPECT
MORE SCATTERED THUNDERSTORMS DEVELOPING TOMORROW AFTERNOON AROUND
LARAMIE AND CHEYENNE...BUT COVERAGE ELSEWHERE BEFORE 00Z NOT
EXPECTED TO BE SIGNIFICANT ENOUGH TO WARRANT A MENTION IN THE
FORECAST FOR NOW. 02/GARMON
&&
.FIRE WEATHER...
ISSUED AT 230 PM MDT TUE AUG 5 2014
MONSOONAL MOISTURE FROM THE SOUTHWEST WILL CONTINUE TO BRING THE
AREA CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE WEEK.
AFTERNOON HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL THRESHOLDS
THROUGH SATURDAY...MAINLY FALLING TO THE LOW TO MID 20 PERCENT
RANGE. EXPECT FAIR OVERNIGHT RECOVERIES IN HUMIDITY WEST OF THE
LARAMIE RANGE WITH EXCELLENT RECOVERIES EAST. DECREASING COVERAGE
OF SHOWERS AND THUNDERSTORMS FROM TODAY ON FOR THE MOST PART AS
MONSOONAL MOISTURE GETS SHUNTED SOUTH AND EAST. WINDS TO REMAIN
LIGHT THROUGH THE WEEK AS WELL...KEEPING ELEVATED FIRE WEATHER
CONDITIONS IN CHECK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...GARMON
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...GARMON
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
600 PM MDT TUE AUG 5 2014
.UPDATE...FOR EARLY EVENING AVIATION PACKAGE. 02/GARMON
&&
.SHORT TERM...(THIS AFTERNOON THROUGH WEDNESDAY NIGHT)
ISSUED AT 230 PM MDT TUE AUG 5 2014
WATER VAPOR IMAGERY STILL SHOWING MONSOONAL MOISTURE OVER THE
STATE OF WYOMING THIS AFTERNOON...BUT A LARGE DRY SLOT CONTINUES
TO EDGE NORTHEAST FROM UTAH AND SOUTHWESTERN COLORADO. PLUME OF
DEEPEST MOISTURE IS NOW OFF TO OUR EAST IN CENTRAL NEBRASKA AND
SOUTH DAKOTA. AT THE SURFACE...THE FRONTAL BOUNDARY THAT MOVED
INTO THE AREA LAST NIGHT AND THIS MORNING IS LAYING UP AGAINST THE
LARAMIE RANGE AND IS THE FOCUS FOR SHOWERS AND THUNDERSTORM
DEVELOPMENT. MOSAIC RADAR SHOWS CONVECTION CONCENTRATED EAST OF
THE LARAMIE RANGE AND ACROSS THE SOUTHERN PANHANDLE SO FAR TODAY.
WIDELY SCATTERED SHOWERS AND THUNDERSTORMS ACROSS SOUTHWESTERN
WYOMING AND NORTHWESTERN COLORADO CONTINUE TO MOVE NORTHEAST. SOME
OF THIS ACTIVITY WILL MAKE ITS WAY INTO CARBON AND ALBANY COUNTIES
THIS AFTERNOON IF IT HOLDS TOGETHER.
MINOR WAVE SEEN ON WATER VAPOR IMAGERY WILL TRACK FROM SOUTHWEST
WYOMING THROUGH CENTRAL WYOMING AND THEN EAST IN SOUTH DAKOTA
THROUGH THE AFTERNOON. THIS SHOULD AID IN INCREASING PRECIP
COVERAGE. LATEST HRRR FORECAST SHOWS BANDS OF SHOWERS/TSTMS
DEVELOPING OVER THE LARAMIE RANGE...THEN MOVING EAST NORTHEAST
INTO THE PANHANDLE THIS AFTERNOON. COULD SEE A MARGINALLY SEVERE
THUNDERSTORM EVENT ACROSS THE NORTHERN PANHANDLE TODAY WITH
SBCAPES AROUND 1200-1400 J/KG AROUND ALLIANCE AND CHADRON. THEY
ARE STILL CAPPED PRETTY GOOD THOUGH SO FAR. NAM SOUNDINGS SHOWING
THIS CAP BREAKING AROUND 21Z OR SO AND HRRR SHOWING A PRETTY
STRONG CELL DEVELOPING SOUTH OF MONTROSE IN SIOUX COUNTY OUT IN
THE NORTHERN PANHANDLE BY LATE AFTERNOON.
WITH THE SHORTWAVE MOVING THROUGH THE AREA THIS EVENING...THE
FRONTAL SYSTEM BEGINS TO BE LIFTED NORTHEAST. SHOWERS AND
THUNDERSTORMS SHOULD DECREASE IN COVERAGE ACROSS EXTREME SOUTHEAST
WYOMING AND THE SOUTHERN PANHANDLE THIS EVENING.
SHOWERS AND THUNDERSTORMS RETURN WEDNESDAY AFTERNOON WITH THE
ECMWF AND NAM/WRF MODELS IN GOOD AGREEMENT. BEST AREA FOR
CONVECTION LOOKS TO BE EAST OF THE LARAMIE RANGE AND THE PANHANDLE
BY MID AFTERNOON PERSISTING INTO MID EVENING BEFORE TAPERING OFF
WITH LOSS OF DAYTIME HEATING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 1159 AM MDT TUE AUG 5 2014
THURSDAY...EVEN THOUGH RIDGING ALOFT WILL LIMIT AREAL THUNDERSTORM
COVERAGE...LOOKS LIKE ENOUGH LOW AND MID LEVEL MOISTURE FOR LATE DAY
ISOLATED TO SCATTERED THUNDERSTORMS...MOST NUMEROUS FROM SIDNEY TO
CHADRON WHERE UPWARD VERTICAL MOTION WILL BE MOST PRONOUNCED.
FRIDAY...INCREASE IN LOW AND MID LEVEL MOISTURE ALONG WITH A WELL
PRONOUNCED LOW AND MID LEVEL THETA-E RIDGE AXIS WILL AID IN AT LEAST
SCATTERED AFTERNOON THUNDERSTORMS EAST OF INTERSTATE 25.
SATURDAY...AS THE ATMOSPHERE DRIES SOMEWHAT FROM FRIDAY...WE EXPECT
A CORRESPONDING DECREASE INT THE AREAL THUNDERSTORM COVERAGE. BEST
CHANCES FOR STORMS WILL BE ALONG WESTERN NEBRASKA WHERE A LOW LEVEL
CONVERGENCE AXIS IS PROGGED TO DEVELOP.
SUNDAY/TUESDAY...ISOLATED LATE DAY THUNDERSTORMS WILL OCCUR WITH
ADEQUATE LOW AND MID LEVEL MOISTURE AND WEAK LOW LEVEL UPSLOPE EAST
WINDS.
MONDAY...MINIMAL THUNDERSTORM CHANCES WITH RIDGING ALOFT AND LIMITED
LOW AND MID LEVEL MOISTURE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 600 PM MDT TUE AUG 5 2014
SCATTERED THUNDERSTORMS CURRENTLY MOVING EAST INTO THE NEBRASKA
PANHANDLE WILL CONTINUE TO BE IN VICINITY OF
CHADRON...SCOTTSBLUFF...ALLIANCE AND SIDNEY THROUGH 03Z BEFORE
DIMINISHING. LOOKING WEST...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WILL BE IN THE VICINITY OF RAWLINS...LARAMIE AND
CHEYENNE UNTIL 02Z BEFORE DIMINISHING. FOR THE OVERNIGHT PERIOD
INTO WEDNESDAY MORNING...LATEST HIGH RESOLUTION RAPID REFRESH
MODEL RUN STILL DEPICTING IFR CEILINGS FROM STRATUS WORKING
SOUTHEAST INTO THE CHADRON...ALLIANCE...AND SCOTTSBLUFF AREAS
AFTER MIDNIGHT IN NORTHEASTERLY UPSLOPE FLOW...AND WE HAVE KEPT IFR
CEILINGS PREVAILING IN THE FORECAST FOR MUCH OF OUR WESTERN
NEBRASKA PANHANDLE SITES BETWEEN 09Z AND 16Z. OTHERWISE...EXPECT
MORE SCATTERED THUNDERSTORMS DEVELOPING TOMORROW AFTERNOON AROUND
LARAMIE AND CHEYENNE...BUT COVERAGE ELSEWHERE BEFORE 00Z NOT
EXPECTED TO BE SIGNIFICANT ENOUGH TO WARRANT A MENTION IN THE
FORECAST FOR NOW. 02/GARMON
&&
.FIRE WEATHER...
ISSUED AT 230 PM MDT TUE AUG 5 2014
MONSOONAL MOISTURE FROM THE SOUTHWEST WILL CONTINUE TO BRING THE
AREA CHANCES FOR SHOWERS AND THUNDERSTORMS THROUGH THE WEEK.
AFTERNOON HUMIDITIES EXPECTED TO REMAIN ABOVE CRITICAL THRESHOLDS
THROUGH SATURDAY...MAINLY FALLING TO THE LOW TO MID 20 PERCENT
RANGE. EXPECT FAIR OVERNIGHT RECOVERIES IN HUMIDITY WEST OF THE
LARAMIE RANGE WITH EXCELLENT RECOVERIES EAST. DECREASING COVERAGE
OF SHOWERS AND THUNDERSTORMS FROM TODAY ON FOR THE MOST PART AS
MONSOONAL MOISTURE GETS SHUNTED SOUTH AND EAST. WINDS TO REMAIN
LIGHT THROUGH THE WEEK AS WELL...KEEPING ELEVATED FIRE WEATHER
CONDITIONS IN CHECK.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...GARMON
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
238 PM MDT MON AUG 4 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY EVENING)
ISSUED AT 230 PM MDT MON AUG 4 2014
CURRENTLY...WATER VAPOR IMAGERY SHOWING MONSOONAL MOISTURE MOVING
INTO OUR WESTERN ZONES THIS AFTERNOON AS THE UPPER LOW THAT WAS
OVER SOUTHERN CALIFORNIA YESTERDAY MOVES INTO CENTRAL UTAH. 12Z
PWATS ON THE GJT SOUNDING OVER 1.2 INCHES. THIS MOISTURE IS HEADED
OUR WAY. MOSAIC RADAR SHOWING FAIRLY WIDESPREAD LIGHT RAIN OVER
CARBON COUNTY. A FEW THUNDERSTORMS DEVELOPING NEAR ARLINGTON AND
CENTENNIAL WITH A FEW LIGHTNING STRIKES OBSERVED. BEGINNING TO SEE
SOME CELLS DEVELOPING ON THE RADAR UP BY VEDAUWOO...SO SHOWERS
HERE AT CHEYENNE ARE NOT THAT FAR OFF.
FOR THIS AFTERNOON...LATEST HRRR FORECAST SHOWING CELLS DEVELOPING
OVER THE LARAMIE RANGE AND DRIFTING EAST. ITS SHOWING A FAIRLY
WIDESPREAD BAND OF SHOWERS AND THUNDERSTORMS MOVING SLOWLY EAST
INTO THE PANHANDLE AROUND THE 23Z TIME FRAME. STORMS ARE GOING TO
BE VERY SLOW MOVING...FROM THE SOUTHWEST AT UNDER 5KTS. THOSE
AREAS THAT DO EXPERIENCE THUNDERSTORMS THIS AFTERNOON AND THIS
EVENING COULD SEE CONSIDERABLE RAINFALL WITH THESE SLOW MOVING
STORMS.
UPPER SHORTWAVE MOVES BEST LIFT NORTH THIS EVENING...SO WE SHOULD
SEE A LULL IN CONVECTION AFTER 03Z OR SO UNTIL TUESDAY. DRIED OUT
THE SOUTHERN PANHANDLE AND SOUTHEAST WYOMING FROM LARAMIE TO
WHEATLAND TO TORRINGTON THIS EVENING.
NEXT PIECE OF ENERGY TO MOVE THROUGH THE AREA TUESDAY AFTERNOON
AND EVENING AS THE UPPER LOW OPENS UP AND TRACKS INTO WESTERN
WYOMING. NAM AND ECMWF SHOW GOOD QPF ACROSS MOST OF THE
CWFA...CONCENTRATED ACROSS THE SOUTHERN PANHANDLE AND LARAMIE
COUNTY TUESDAY AFTERNOON. STILL NOT MUCH IN THE STEERING FLOW...SO
STORMS WILL ONCE AGAIN BE SLOW MOVING AND PRODUCING MODERATE TO
HEAVY RAINFALL INTO TUESDAY EVENING.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 1222 PM MDT MON AUG 4 2014
WEDNESDAY...DESPITE A SHORTWAVE RIDGE ALOFT OVER OUR COUNTIES...WITH
A LOW LEVEL CONVERGENCE BOUNDARY INDICATED FROM DOUGLAS TO
CHEYENNE...ALONG WITH ADEQUATE LOW AND MID LEVEL MOISTURE AND DECENT
UPWARD VERTICAL MOTION FROM DOUGLAS TO CHEYENNE...HAVE BOOSTED
AFTERNOON AND EVENING POPS INTO THE 45 TO 70 PERCENT RANGE...WITH
LESSER POPS ELSEWHERE. WITH WEAK STEERING WINDS...WILL LIKELY SEE A
FEW HEAVY RAINERS AS WELL.
THURSDAY...NEXT SHORTWAVE TROUGH ALOFT MOVES INTO WESTERN WYOMING
AND UTAH...WHILE A LOW LEVEL CONVERGENCE AXIS SETS UP FROM NORTH
CENTRAL COLORADO NORTHWARD TO NEAR TORRINGTON TO NEAR CHADRON.
850/700 MB THETA-E RIDGE AXIS...WELL PRONOUNCED...WILL EXTEND NORTH
TO SOUTH IN THE AFTERNOON ACROSS FAR EASTERN WYOMING AND WESTERN
NEBRASKA...AND WITH PROGGED INSTABILITIES...CAPE AND DECENT
DIRECTIONAL SHEAR...EXPECT A FEW STRONG TO SEVERE THUNDERSTORMS EAST
OF A LUSK TO CHEYENNE LINE...AND HAVE ALSO BOOSTED POPS EAST OF THIS
LINE TO THE 50 TO 60 PERCENT RANGE WITH ALL CONVECTIVE AND MESOSCALE
PARAMETERS COMING TOGETHER.
FRIDAY...LESS LATE DAY COVERAGE OF SHOWERS AND THUNDERSTORMS
EXPECTED WITH DECREASE IN LOW AND MID LEVEL MOISTURE...THOUGH WILL
STILL SEE ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE
AFTERNOON AND EVENING WITH MOIST UPSLOPE MECHANICAL LIFT.
SATURDAY...SIMILAR SCENARIO TO FRIDAY...ALBEIT WITH SLIGHTLY LESS
COVERAGE OF SHOWERS AND THUNDERSTORMS DUE TO LESS LOW AND MID LEVEL
MOISTURE AVAILABILITY.
SUNDAY...RIDGING ALOFT STRENGTHENS OVER OUR COUNTIES...THUS EXPECT
SLIGHTLY LESS COVERAGE OF LATE DAY SHOWERS AND
THUNDERSTORMS...FOCUSED ALMOST EXCLUSIVELY OVER THE MOUNTAINS AND
HIGHER TERRAIN SUCH AS THE PINE RIDGE FROM NEAR LUSK TO NEAR CHADRON.
MONDAY...EVEN MORE PRONOUNCED RIDGING ALOFT...AND WITH THE BULK OF
THE MONSOONAL MOISTURE RESIDING OVER COLORADO...WILL ONLY FORECAST
ISOLATED LATE DAY THUNDERSTORMS OVER AND NEAR THE SNOWY...SIERRA
MADRE AND SOUTHERN LARAMIE RANGES...THOUGH WE WILL NEED TO WATCH FOR
POSSIBLE GREATER INTRUSION OF MID LEVEL MONSOONAL MOISTURE AS IS
TYPICAL FOR LATE JULY AND EARLY AUGUST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY MORNING)
ISSUED AT 1057 AM MDT MON AUG 4 2014
EXPECT CONVECTION TO CONTINUE EXPANDING THIS AFTERNOON...IMPACTING
OUR SOUTHEAST WYOMING AIRPORTS. INITIALLY BEGINNING OVER
KRWL...THEN EXPANDING EASTWARD TO KLAR AND KCYS. SHOWERS COULD BE
HEAVY AT TIMES...REDUCING VISIBILITIES DOWN TO 3 MILES AT TIMES.
THIS CONVECTION WILL THEN SPREAD OUT INTO THE NEBRASKA PANHANDLE
SHORTLY BEFORE AND A FEW HOURS AFTER 00Z. LATEST SREF GUIDANCE
SHOWING MVFR/IFR CEILINGS DEVELOPING IN THE NORTHERN NEBRASKA
PANHANDLE...IMPACTING KCDR AND POSSIBLY KAIA TUESDAY MORNING.
&&
.FIRE WEATHER...
ISSUED AT 230 PM MDT MON AUG 4 2014
MONSOONAL MOISTURE WILL STAY WITH US THROUGH MOST OF THE WEEK
GIVING MOST AREAS CHANCES FOR WETTING RAINS AND THUNDERSTORMS ON A
DAILY BASIS. WINDS TO REMAIN WEAK AND AFTERNOON HUMIDITIES FAIRLY
HIGH...MITIGATING ANY FIRE WEATHER CONCERNS. MIN HUMIDITIES
EXPECTED TO STAY IN THE MID 20 PERCENT RANGE THROUGH THE WEEK WITH
EXCELLENT OVERNIGHT RECOVERIES.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...CLAYCOMB
LONG TERM...RUBIN
AVIATION...CLAYCOMB
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1237 AM CDT Wed Aug 6 2014
...Updated aviation discussion...
.SHORT TERM...(This evening through Wednesday)
ISSUED AT 309 PM CDT TUE AUG 5 2014
The primary focus will be convection this evening and how expansive
it will be this evening across western Kansas. Water vapor loop
early this afternoon showed a substantial mid level dry intrusion
into the southwestern CONUS which was pushing northeastward through
Colorado. RAP analysis revealed a fairly perturbed middle
troposphere from the primary vorticity anomaly across
central/northern California...eastward through Utah and into
Colorado. A 250mb jet streak continued to nose northeastward into
southern California through southern Utah. A lee trough convergence
axis was found across far southeastern Colorado into far
northwestern Kansas. This was on the western periphery of deep mid
level moisture plume. All the short-term high resolution models
suggest convection continuing to develop along the lee trough
convergence axis and also over terrain-favored regions of Colorado.
There is the suggestion that the most organized of lee trough
convection will stay just north of the DDC forecast area from far
west-central KS into northwestern KS. Both the 12Z WRF ARW and NMMB
show a cluster of pseudo-organized convection rolling east-southeast
reaching roughly a Leoti to Gove line by around 06Z. The best of the
lee trough convergence will be farther north, so it would make sense
that the high resolution models are keeping the most sustained
convection across northwestern Kansas. Other less organized
convection farther south may last through sunset, but not much after
that. We will keep Chance POPs confined to far west-central KS
(Kearny to Scott County). South winds tonight averaging 12 to 15
knots will keep the boundary layer mixed enough through the night
that temperatures will likely plateau during the 06-12Z time frame
in the lower 70s along/east of Highway 283. The trough axis will
shift east Wednesday with lighter winds much of the day across much
of southwest Kansas. Weak convergence along the trough may yield
late afternoon convection, but only loosely organized convection at
best can be expected with the deep frontogenetic forcing still north
of the southwest Kansas region through late afternoon Wednesday.
.LONG TERM...(Wednesday night through Tuesday)
ISSUED AT 246 PM CDT TUE AUG 5 2014
No significant changes were made to the extended period of the
forecast. Wednesday night, and through the overnight into Thursday
morning will present chances for convection along a weak boundary
and area of surface low pressure over western Kansas. The model
signals for this suggest the best chances for isolated to scattered
thunderstorms will be across central Kansas where instability and
CAPE will be greater. Any storms along this convergence zone should
end by Thursday morning across the south central Kansas counties
rendering Thursday dry for most of the day. Convection will again be
possible in the far west on Thursday evening and through the night
as it forms diurnally along the high terrain of eastern Colorado
with the aid of upslope surface flow and higher dew points around
60 degrees or more.
Beyond Friday, the region will remain in a fairly westerly zonal
pattern but also not a particularly strong surface gradient, leading
to relatively light winds. As the region will remain fairly rich
ion surface moisture and warm, any local areas of uncapped
convergence could set off afternoon convection lasting into the very
early evening through about Tuesday. However chances as far as areal
coverage are concerned should be fairly minimal.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1237 AM CDT WED AUG 6 2014
Showers and weak thunderstorms will continue to propagate east across
western into central Kansas through sunrise. The main area of storms
over far west central Kansas has been showing a decreasing trend and
should continue to do so but some mid level forcing should keep at
least some storm redevelopment through sunrise. Will carry VCTS at
the Garden City, Dodge City and Hays through the late night hours.
Southerly winds at 10 to 15 knots will diminish and become southwest
to northwest during the day as a surface low pressure trough moves
east through the area.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 67 92 68 91 / 20 10 20 30
GCK 66 92 67 89 / 20 10 30 30
EHA 66 95 67 92 / 10 20 20 30
LBL 68 97 69 95 / 20 10 20 30
HYS 67 93 65 88 / 30 10 40 30
P28 70 95 71 94 / 30 10 10 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Russell
AVIATION...Gerard
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
339 AM EDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT WED AUG 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE GREAT LKS BTWN STUBBORN CLOSED LO OVER QUEBEC AND MEAN UPR RDG
EXTENDING FM SCENTRAL CANADA SWD THRU THE PLAINS. A SHRTWV EMBEDDED
IN THIS NNW FLOW IS DIGGING TOWARD WRN LK SUP AND SUPPORTING A
CLUSTER OF SHOWERS OVER THE WRN LK EARLY THIS MRNG. BUT CLD TOP
TEMPS ARE TENDING TO WARM/SHOWERS WEAKEN A BIT WITH NOCTURNAL
COOLING AND AS THE PCPN AREA MOVES INTO A MORE STABLE ENVIRONMENT
OVER UPR MI REPRESENTED BY THE 00Z GRB RAOB. BEHIND THIS CLD
CLUSTER...SKIES ARE MOCLR OVER NW ONTARIO UNDER AREA OF MID LVL DRY
AIR ASSOCIATED WITH DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE
DIGGING SHRTWV AND SFC HI PRES. ANOTHER SHRTWV IS PRESENT OVER SRN
SASKATCHEWAN MOVING E THRU THE MEAN UPR RDG.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH THE
HI PRES IN NW ONTARIO FCST TO DOMINATE IN THE WAKE OF SHRTWV THAT WL
BE CROSSING THE UPR LKS THIS MRNG.
TODAY...LINGERING SHOWERS OVER WRN UPR MI AND BAND OF CLDS
ASSOCIATED WITH DIGGING SHRTWV WL CROSS UPR MI EARLY THIS MRNG.
APRCH OF SHRTWV RDG/RISING HGTS/DNVA/MID LVL DRYING IN THE WAKE OF
THIS DISTURBANCE WL CAUSE CONDITIONS TO TURN MOSUNNY WITH ONLY SOME
DIURNAL CU AS SFC HI PRES BLDS OVER UPR MI. FCST H85 TEMPS AS HI AS
14C OVER WRN UPR MI WL ALLOW MAX TEMPS TO PEAK NEAR 80 AWAY FM LK
MODERATION...WHICH WL OCCUR PRIMARILY DOWNWIND OF LK SUP UNDER
SYNOPTIC N H925 FLOW IN THE WAKE OF DEPARTING SHRTWV THAT WL
ACCENTUATE THE INLAND PENETRATION OF LK BREEZES OFF THE BIG LK. THE
00Z REGIONAL CNDN MODEL DOES GENERATE SOME ISOLD SHOWERS ALONG LK
BREEZE BNDRYS...BUT WL MAINTAIN GOING DRY FCST GIVEN THE NEGATIVE
DYNAMICS/LARGER SCALE DRYING AND ABSENCE OF QPF FM OTHER GUIDANCE.
COOLING NEAR LK MI WL BE MORE LOCALIZED. MIN AFTN RH WL DROP AS LO
AS 30-35 PCT OVER THE INTERIOR W HALF WITH DAYTIME MIXING OF
INCOMING DRIER AIR THAT WL CAUSE SFC DEWPTS TO FALL OFF INTO THE UPR
40S THIS AFTN. WINDS SHOULD BE NO HIER THAN ABOUT 10 MPH AWAY FM LK
BREEZES...ALLEVIATING FIRE WX CONCERNS. THERE COULD BE GUSTIER WINDS
BEHIND THE LK BREEZE BNDRYS OFF LK SUP...BUT THE AIR WL BE MOISTER
THERE.
TNGT...SFC HI PRES IS FCST TO MOVE OVHD UNDER BLDG UPR RDG. IN THE
PRESENCE OF PWAT FALLING TOWARD 0.5 INCH /40-50 PCT OF NORMAL/...
MOCLR SKIES AND LGT WINDS...EXPECT A HEALTHY DIURNAL TEMP DROP INTO
THE 40S OVER THE INTERIOR. WL ADD PATCHY FOG OVER THE COOLER
INTERIOR LOCATIONS FOR THE OVERNGT TIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 AM EDT WED AUG 6 2014
THURSDAY THROUGH SATURDAY...BROAD SURFACE RIDGING ALONG WITH UPPER
LEVEL 500MB RIDGING WILL BE IN PLACE ACROSS MUCH OF THE UPPER GREAT
LAKES REGION THROUGH THIS TIME FRAME. DRY WEATHER WILL BE THE RULE
UNDER THE RIDGE AS MOISTURE ADVECTION WILL BE LIMITED WITH VERY LOW
DEEP LAYER 1000-500MB RH VALUES. THE SURFACE HIGH WILL REMAIN
DIRECTLY OVERHEAD THROUGH FRIDAY BEFORE SLOWLY SHIFTING TO THE EAST
DURING THE DAY SATURDAY. THIS WILL KEEP LIGHT WINDS IN THE FORECAST
WITH THE STRONGEST GUSTS ASSOCIATED WITH LAKE BREEZE DEVELOPMENT
DURING THE AFTERNOON HOURS. AS PREVIOUS SHIFT MENTIONED...MOST AREAS
OF THE CWA HAVE SEEN LITTLE TO NO PRECIPITATION OVER THE PAST COUPLE
WEEKS WHICH MEANS SOIL AND VEGETATION ARE BEGINNING TO GET FAIRLY
DRY. DECENT MIXING CONDITIONS ARE EXPECTED TO OCCUR EACH AFTERNOON
THROUGH THIS TIME PERIOD...WHICH WILL LEAD TO INCREASED FIRE
DANGER...FORTUNATELY...WINDS WILL BE GENERALLY LIGHT AS PREVIOUSLY
MENTIONED. HAVE CONTINUED THE TREND OF LOWERING AFTERNOON DEWPOINTS
AS SOME OF THE DRIER AIR ALOFT MIXES DOWN TO THE SURFACE WITH
AFTERNOON HEATING. TEMPERATURES WILL BE CONTINUE TO WARM THROUGH
THIS PERIOD WITH 850MB TEMPS WARMING FROM 12C THURSDAY AFTERNOON TO
AROUND 14C BY SATURDAY AFTERNOON AS THE HIGH TREKS SLOWLY EASTWARD.
SATURDAY NIGHT THROUGH THE REMAINING EXTENDED...THE NEXT UPPER LEVEL
TROUGH AND DEVELOPING SURFACE LOW ARE PROGGED TO BE NEAR THE
SASKATCHEWAN/MANITOBA BORDER SATURDAY NIGHT WITH A COLD FRONT
STRETCHING SOUTHWESTWARD ACROSS THE DAKOTAS AS SHOWN BY ANALYZING
850 THETA E ALONG WITH SURFACE WINDS. THIS WILL BE THE MAIN FOCUS
FOR SHOWER AND THUNDERSTORM ACTIVITY. THE LOW WILL SHIFT EASTWARD TO
NORTHERN QUEBEC BY MONDAY AFTERNOON AS THE FRONT DRAPES ACROSS THE
UPPER GREAT LAKES. AT THIS POINT HAVE KEPT CHANCE POPS IN THE
FORECAST PEGGED MAINLY TO THE FRONT...DID NOT INCREASE TO LIKELY
POPS DUE TO CONTINUED TIMING ISSUES. RIGHT NOW THE BEST CHANCE OF
SHOWER AND THUNDERSTORM ACTIVITY WOULD BE DURING THE LATE SUNDAY
NIGHT THROUGH MONDAY TIME FRAME...WHICH WILL ALSO BE AROUND THE SAME
TIME THAT THE UPPER LEVEL 500MB TROUGH AXIS SWINGS ACROSS THE AREA.
THE FRONT IS PROGGED TO BE EAST OF THE AREA BY
TUESDAY...HOWEVER...WITH UPPER LEVEL TROUGHING AND LINGERING
MOISTURE NEARBY...WOULD EXPECT SHOWERS TO LINGER THROUGH THE DAY
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 125 AM EDT WED AUG 6 2014
EXCEPT FOR SOME SHALLOW GROUND FOG THAT WILL BRING IFR VSBYS TO IWD
AT TIMES EARLY THIS MRNG...VFR CONDITIONS SHOULD PREDOMINATE AT THE
TAF SITES WITH HI PRES BLDG INTO THE UPR LKS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 AM EDT WED AUG 6 2014
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN INTO THE UPCOMING
WEEKEND...LEADING TO LIGHT WINDS BELOW 15 KTS THRU SAT AND NEAR CALM
WAVES. S WINDS MAY INCREASE UP TO 20 KTS ON SUN AS THE PRES GRADIENT
TIGHTENS OVER THE AREA BETWEEN THE HI PRES SHIFTING TO THE E AND AN
APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
359 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED AUG 6 2014
TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS IN THE MODELS HAS
VANISHED LEAVING FOR SOMEWHAT NEBULOUS DYNAMICAL FORCING TODAY
AND TONIGHT. THIS IS OCCURRING AS A RESULT OF HEIGHT RISES
ASSOCIATED WITH A DEPARTING UPPER LOW ACROSS THE CANADIAN
MARITIMES. THERE ARE ALSO INDICATIONS OF DRYING IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE ALSO. PRECIPITABLE WATER FALLS
BELOW 1.5 INCHES IN MANY AREAS.
WATER VAPOR SHOWS ANOTHER DISTURBANCE ACROSS NORTHWESTERN
COLORADO THIS MORNING AND A SECOND WEAKER DISTURBANCE ACROSS
NORTH CENTRAL COLORADO AND SOUTHEASTERN WYOMING. BOTH COULD SERVE
AS FORCING MECHANISMS FOR TSTM DEVELOPMENT. THE NAM AND OTHER
MODELS SHOW POCKETS OF K INDICES AROUND 40C THIS AFTN...MAINLY
ACROSS WESTERN NEBRASKA. THIS MOISTURE IS POOLING BEHIND THE SFC
LOW PRESSURE SYSTEM ACROSS CNTL NEB. GIVEN THE PROXIMITY OF THESE
DISTURBANCES IT WOULD APPEAR THE BETTER CHANCES OF RAIN WOULD
OCCUR FROM NOON THROUGH EARLY EVENING.
THUS THE MODELS SHOW DISORGANIZED AREAS OF SHOWERS AND
THUNDERSTORMS TODAY WHICH BECOME ISOLATED TONIGHT. THIS IS LIKELY
THE RESULT OF THE LACK OF FOCUS IN THE LOWER LEVELS OF THE
ATMOSPHERE. THE FORECAST CALLS OF ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY THIS AFTERNOON WHICH BECOMES
ISOLATED TONIGHT. MODEL BLENDED QPF AND POPS FEATURE THE BEST
CHANCES ACROSS THE NCNTL ZONES EAST OF VALENTINE INCLUDING CUSTER
COUNTY. THIS FORECAST USES 50 PERCENT OF THE
ECM...GFS...NAM...GEM AND SREF AND 50 PERCENT OF THE RAP MODEL
HAS PERFORMED FAIRLY WELL.
COOLER AIR WILL FILLS IN BEHIND THE SFC LOW AS IT MIGRATES SOUTH
AND EAST INTO KANSAS AND SOUTHEAST NEBRASKA. THIS SHOULD KEEP
HIGHS IN THE UPPER 70S TO UPPER 80S TODAY WITH HIGH HUMIDITY ONCE
AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED AUG 6 2014
LITTLE CHANGE FOR THURSDAY AS UPPER RIDGE LOCATES ACROSS THE
SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. RIDGE RIDERS TO CROSS
THE CENTRAL ROCKIES AND ONTO THE HIGH PLAINS. MODELS IN GOOD
AGREEMENT BRINGING A DISTURBANCE ACROSS THE AREA LATE THURSDAY.
MODELS DROP PWATS EARLY...HOWEVER AN INCREASE IS EXPECTED TO
GREATER THAN 2 SD BY LATE AFTERNOON. MODELS ARE CURRENTLY
FAVORING SW NEB AND WILL RETAIN HIGHEST POPS...LIKELY...THERE.
MODELS CONTINUE TO AGREE BRINGING ADDITIONAL WAVES ACROSS THE
AREA INTO THE WEEKEND. RAIN CHANCES WILL REMAIN
POSSIBLE...HOWEVER COVERAGE STILL IN QUESTION. TEMPS ARE A LITTLE
TRICKY AS THE RIDGE CONTINUES TO FLATTEN...AND CLOUD COVER WILL
BE KEY TO AFTERNOON PEAKS. GENERALLY EXPECT HIGHS AT OR BELOW
SEASONAL NORMS...WHICH IS IN THE MID AND UPPER 80S.
AS WE GO INTO NEXT WEEK MODELS DIVERGE. THE GFS BEGINS TO REBUILD
THE RIDGE IN THE WEST...WHILE THE ECMWF KEEPS THE RIDGE
FLATTENED. THE GFS WOULD FAVOR A WARMER FORECAST COMPARED TO THE
EC...HOWEVER AS THE RIDGE BUILDS...PER GFS SOLUTION...NORTHWEST
FLOW WOULD CONTINUE TO BRING DISTURBANCES ACROSS THE AREA. THUS
WILL KEEP THE BLENDED FORECAST AS WILL STILL HAVE AT LEAST
PERIODIC LOW CHANCES FOR RAIN. LESS CERTAINTY FOR TEMPS AND WILL
KEEP BLENDED GUIDANCE AND MONITOR TO SEE HOW MODELS CHANGE OVER
THE COMING DAYS TO MAKE ADJUSTMENTS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1227 AM CDT WED AUG 6 2014
ONE LARGE AREA OF SHOWERS AND THUNDERSTORMS IN NORTH CENTRAL AND
NORTHEAST NEBRASKA WILL AFFECT THE AREA INCLUDING VTN...ANW AND
ONL UNTIL 10Z OR 11Z. AFTER THE STORMS END...RESIDUAL MOISTURE ON
AN EAST TO SOUTHEAST WIND WILL RESULT IN WIDESPREAD STRATUS WITH
PATCHY MIST OR FOG. CEILINGS BELOW 1500 FEET AGL ARE LIKELY. A
CONSENSUS OF SHORT RANGE PROJECTIONS WOULD INDICATE WIDESPREAD
CEILINGS BELOW 1000 FEET AGL OVER MUCH OF NORTHERN NEBRASKA
INCLUDING ONL...ANW... VTN AND MHN.
ANOTHER AREA OF CONCERN IS SOUTHWEST NEBRASKA WHICH COULD BE
AFFECTED BY SHOWERS AND THUNDERSTORMS COMING OUT OF NORTHEAST
COLORADO. CURRENT TRENDS FROM RADAR INDICATE THAT THEY WILL STAY
SOUTH OF BBW...LBF AND OGA BUT WILL PROBABLY AFFECT IML.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
308 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 214 AM CDT WED AUG 6 2014
TIMING AND EXTENT OF NUMEROUS PRECIP EVENTS REMAINS THE MAIN
CONCERN AND PROBLEM DURING THE PERIOD.
SCATTERED CONVECTION EXTENDED FROM NORTH CENTRAL NEBRASKA INTO
SOUTH CENTRAL IOWA AT 07Z GENERALLY ALONG AXIS OF 850-700MB
MOISTURE ADVECTION AND NORTH OF WEAK SURFACE BOUNDARY OVER
SOUTHEAST NEBRASKA. SHORT RANGE RAP MAINTAINS THE PRIMARY AXIS
NEAR NORTHERN BORDER OF THE FORECAST AREA THROUGH THE MORNING WITH
SOME DRIFT TO THE NORTH THIS AFTERNOON AS UPPER WAVE TRACKS
SOUTHEAST ACROSS EASTERN NEBRASKA. CURRENT POPS BASED ON THIS IDEA
WITH LIKELY ACROSS NORTHERN AREAS AND CHANCE ELSEWHERE.
MODELS DROP WESTERN NEBRASKA SURFACE WAVE INTO WESTERN KANSAS BY
EVENING WITH ASSOCIATED BOUNDARY ALSO MOVING SOUTH AND EAST
TONIGHT. PRECIP LOOKS TO BECOME MORE NORTH SOUTH ORIENTED TONIGHT
ACROSS THE AREA IN LINE WITH LOW LEVEL TEMPERATURE AND MOISTURE
ADVECTION WITH A GENERAL DRIFT TO THE EAST. POPS DECREASE WEST TO
EAST LATE TONIGHT INTO THURSDAY AS THE UPPER WAVE AND BETTER
MOISTURE MOVE INTO THE MISSISSIPPI VALLEY.
ON THURSDAY NIGHT MODELS SUGGEST DEVELOPMENT OF CONVECTIVE SYSTEM
OVER THE HIGH PLAINS THURSDAY EVENING AS ANOTHER UPPER WAVE
APPROACHES THAT THEN MOVES EAST THURSDAY NIGHT AND FRIDAY. AT
THIS TIME IT APPEARS MOST OF THE PRECIP WILL REMAIN WEST OF THE
AREA TONIGHT WITH LOW POPS FOR WESTERN PARTS OF THE AREA LATE
TONIGHT INTO FRIDAY.
TEMPERATURE FORECAST A BLEND OF GUIDANCE THROUGH THE PERIOD.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 214 AM CDT WED AUG 6 2014
GENERAL PATTERN CONTINUES INTO THE FIRST PART OF THE EXTENDED
PERIOD WITH POPS FOR MUCH OF THE AREA FRIDAY NIGHT INTO SUNDAY
NIGHT. MODELS REBUILD THE UPPER RIDGE EARLY NEXT WEEK ALTHOUGH
EURO NOT AS QUICKLY AS THE GFS. SOME UNCERTAINTY DURING THIS TIME
REGARDING POPS AS EURO KEEPS UPPER WAVES ACROSS THE AREA. KEEP
FORECAST DRY FOR NOW INSTEAD OF CARRYING SLIGHT POPS.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1158 PM CDT TUE AUG 5 2014
REGIONAL OBS SHOWING CONDITIONS ARE RAPIDLY DETERIORATING ACROSS
ERN NEB IN RESPONSE TO TSRA ACTIVITY INCREASING IN AREAL
COVERAGE. ALL THIS IN PART TO A NEARLY STATIONARY FRONTAL BNDRY
CUTTING ACROSS ERN NEB INTO IA. EXPECT MVFR WITH OCCASIONAL
IFR/TSRA AT ALL TERMINALS THRU ABOUT 13Z THIS MORNING. ACTIVITY
THEN EXPECTED TO PUSH EAST OF TAF SITES. HOWEVER...LIKELY THAT
MVFR CIGS WILL HANG TIGHT AT ALL TERMINALS THRU THE REMAINDER OF
THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1207 AM CDT WED AUG 6 2014
.SHORT TERM...(TONIGHT THROUGH FRIDAY)
ISSUED AT 315 PM CDT TUE AUG 5 2014
MAIN FORECAST CHALLENGE WILL BE PCPN CHANCES/TIMING OVER THE NEXT
SEVERAL DAYS.
SURFACE LOW PRESSURE IS CURRENTLY LOCATED OVER SOUTHWEST
NEBRASKA/NORTHWEST KANSAS WITH A WARM FRONT EXTENDING EASTWARD FROM
THE LOW CENTER ACROSS SOUTHERN NEBRASKA. UPPER LEVEL RIDGE AXIS
CONTINUES TO FLATTEN AND MOVE OVERHEAD WITH SEVERAL EMBEDDED
SHORTWAVE TROUGHS MOVING THROUGH THE FLOW. SOME CONVECTION IS
ALREADY ONGOING ACROSS WESTERN/CENTRAL PORTIONS OF NEBRASKA THIS
AFTERNOON WITHIN STRONG UPSLOPE FLOW. THESE MAY CONTINUE TO SPREAD
EAST INTO OUR FAR NORTHWESTERN COUNTIES LATE THIS AFTERNOON/EARLY
THIS EVENING AS BOTH THE HRRR AND RAP HAVE BEEN INDICATING. BETTER
FORCING FOR ASCENT WILL ENTER INTO THE REGION LATER TONIGHT AS A
PIECE OF SHORTWAVE ENERGY TOPS THE FLATTENING RIDGE. THIS COMBINED
WITH STRONG ISENTROPIC UPGLIDE NEAR THE 315K SURFACE AND PW`S NEAR
2.00" SHOULD LAY OUT 1-2"+ RAINFALL AMOUNTS ACROSS PORTIONS OF
NORTHEAST NEBRASKA AND WEST CENTRAL IOWA. FORECASTED QPF VALUES
HAVE HAD FAIRLY GOOD AGREEMENT ON THE PLACEMENT OF THE BULLSEYE
AND SEE NO REASON TO STRAY.
SFC LOW MOVES SLIGHTLY EAST OVERNIGHT AND HUGS THE WESTERN KS/NE
BORDER BY MORNING. THERE SHOULD BE A LULL IN ACTIVITY EARLY
WEDNESDAY MORNING...BUT CHANCES WILL INCREASE AGAIN WITH DAYTIME
HEATING AND FORCING FROM ANOTHER WEAK APPROACHING SHORTWAVE TROUGH.
THE STALLED FRONTAL BOUNDARY WILL EXTEND EAST ACROSS SOUTHERN
NEBRASKA AND WILL BE THE FOCUS FOR STORMS LATER IN THE DAY OVER OUR
SOUTHEASTERN CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 315 PM CDT TUE AUG 5 2014
INTERMITTENT PCPN CHANCES CONTINUE INTO THE WEEKEND AS EMBEDDED
SHORTWAVES MOVE THROUGH THE WESTERLIES. THE UPPER RIDGE WILL BEGIN
TO AMPLIFY TO OUR WEST EARLY IN THE WEEK ALLOWING A RETURN TO
WARMER AND DRIER CONDITIONS.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1158 PM CDT TUE AUG 5 2014
REGIONAL OBS SHOWING CONDITIONS ARE RAPIDLY DETERIORATING ACROSS
ERN NEB IN RESPONSE TO TSRA ACTIVITY INCREASING IN AREAL
COVERAGE. ALL THIS IN PART TO A NEARLY STATIONARY FRONTAL BNDRY
CUTTING ACROSS ERN NEB INTO IA. EXPECT MVFR WITH OCCASIONAL
IFR/TSRA AT ALL TERMINALS THRU ABOUT 13Z THIS MORNING. ACTIVITY
THEN EXPECTED TO PUSH EAST OF TAF SITES. HOWEVER...LIKELY THAT
MVFR CIGS WILL HANG TIGHT AT ALL TERMINALS THRU THE REMAINDER OF
THE FCST PD.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1129 PM MDT TUE AUG 5 2014
.AVIATION...
06Z TAF CYCLE
VFR CONDITIONS FORECAST AT AREA TERMINALS WITH LIGHT WINDS THROUGH
THE NEXT 24HRS. MVFR CIGS ARE POSSIBLE AT KLVS EARLY WEDNESDAY
MORNING...BUT FORECAST CONFIDENCE TOO LOW TO INCLUDE IN TAF.
11
&&
.PREV DISCUSSION...255 PM MDT TUE AUG 5 2014...
.SYNOPSIS...
SHOWERS AND THUNDERSTORMS WILL FAVOR EASTERN NEW MEXICO THROUGH
THE EVENING HOURS. A FEW STORMS MAY PRODUCE GUSTY WINDS AND HAIL.
ON WEDNESDAY...STORM COVERAGE WILL DECREASE SIGNIFICANTLY AS DRY
AIR CONTINUES TO MOVE INTO THE STATE. IF STORMS DEVELOP...THEY WILL
FAVOR THE SOUTHWEST AND SOUTH CENTRAL MOUNTAINS. MEANWHILE...
TEMPERATURES WILL CLIMB NEAR OR ABOVE SEASONAL NORMALS. MOISTURE
WILL SLOWLY START TO MOVE FROM SOUTH TO NORTH...BACK INTO THE LAND OF
ENCHANTMENT...THURSDAY THROUGH THE WEEKEND. STORM COVERAGE WILL
SLOWLY START TO INCREASE...AND THE POTENTIAL FOR HEAVY RAIN WILL
RETURN. HOWEVER...OVERALL COVERAGE IS EXPECTED TO BE LESS THAN
RECENT WEEKS.
&&
.DISCUSSION...
MUCH DRIER MID AND UPPER LEVEL AIR MOVING INTO NM PER WV SATELLITE
IMAGERY AND 12Z FGZ SOUNDING. AS SUCH...CONVECTION HAS REALLY
STRUGGLED TO START...OR MAINTAIN ITSELF WEST OF THE CENTRAL MTN
CHAIN. MID LEVEL MOISTURE GRADIENT LIKELY SETTING UP ALONG THE
CENTRAL MT CHAIN...AND THIS COMBINED WITH OROGRAPHIC LIFT HAS
PRODUCED A FEW SHOWERS AND TSTMS. WITH THE AID OF A WEAK 700 MB
TROUGH ACROSS NORTHERN NM...AND DRY AIR PUNCHING INTO MID
LEVELS...HAVE ALREADY SEEN ONE SEVERE STORM ACROSS THE NE...AND A
FEW MORE STRONG OR SEVERE STORMS ARE NOT OUT OF THE QUESTION.
QUARTER SIZE HAIL AND GUSTY WINDS WOULD BE THE MAIN THREATS. THE
GOOD NEWS IS THAT WITH STORM MOTIONS AVERAGING 10 TO 20 MPH...THE
THREAT FOR FLOODING HAS CONSIDERABLY DECREASED...THOUGH ALSO NOT OUT
OF THE QUESTION. LATEST AVAILABLE HRRR SUGGESTS THAT MUCH OF THE
CONVECTION TONIGHT WILL DIMINISH BY SUNSET.
DRY AIR CONTINUING TO FILTER IN COMBINED WITH THE UPPER LEVEL HIGH
BUILDING BACK TO THE NORTH WILL RESULT IN AN EVEN BIGGER DOWN TICK
IN STORM COVERAGE ON WEDNESDAY. PWATS LOOK TO CRATER TO AROUND 0.50
INCHES...SIMILAR TO WHAT WAS OBSERVED ON THE FGZ SOUNDING THIS AM.
TEMPERATURES WILL CLIMB SEVERAL DEGREES...WITH ALL AREAS SEEING NEAR
TO ABOVE NORMAL TEMPS FOR THE FIRST TIME IN A WHILE.
MODELS SUGGEST THE UPPER HIGH WILL INCH EASTWARD ON THURSDAY...AS
SOME DISTURBANCE...LIKELY FROM THE PREVIOUS DAYS CONVECTION OVER
MEXICO...WILL MOVE NORTHWARD INTO SOUTHERN NM. PWATS WILL CREEP UP
ON THURSDAY...BUT WILL REMAIN BELOW NORMAL FOR THIS TIME OF YEAR.
NONETHELESS... A FEW MORE STORMS WILL BE POSSIBLE AT LEAST ACROSS
THE SOUTHERN TIER OF THE CWA ON THURSDAY. ADDITIONALLY...THE NAM IS
SUGGESTING AREAS ALONG AND JUST EAST OF THE CENTRAL MT CHAIN WILL BE
A FAVORED AREA FOR STORM DEVELOPMENT. CONTINUED TO CARRY HIGHER POPS
HERE...BUT NOT OVERLY SOLD YET. NEAR AND BEHIND A BACK DOOR FRONT
WITH AMPLE LOW LEVEL MOISTURE BEHIND IT ACROSS THE FAR NE MAY BE A
BETTER BET FOR STORMS.
LOOKING FOR A BIT MORE MOISTURE ON FRIDAY AS THE UPPER HIGH SHIFTS
OVER OKLAHOMA...THOUGH MODELS ARE NOT VERY AMBITIOUS AT BRING THE
MOISTURE NORTHWARD DESPITE THE FAVORABLE PATTERN. THIS MAY CHANGE IN
THE COMING DAYS. THE WEEKEND DOES NOT LOOK TOO MUCH DIFFERENT FROM
FRIDAY...OTHER THAN THERE MAY BE A BIT MORE MOISTURE AND STORMS
AROUND. PWAT VALUES ARE PROGGED TO BE RIGHT AROUND NORMAL FOR
AUGUST. LOOKS LIKE EARLY NEXT WEEK THE UPPER HIGH WILL SHIFT BACK
OVER NM...DIVERTING THE MOISTURE PLUME WESTWARD OVER ARIZONA.
34
&&
.FIRE WEATHER...
NO MAJOR CHANGES TO THE GRIDDED FORECAST. DID LOWER DEWPOINT
VALUES THUS RH ACROSS MOST OF THE FORECAST AREA DURING THE NEXT
FEW DAYS. DESPITE THE DYNAMIC DRY SLOT/MID LEVEL DRY INTRUSION
PATTERN...VEGETATION WILL BE GOING OVERTIME IN TERMS OF
TRANSPIRATION AT NIGHT SO RAISED OVERNIGHT DEWPOINT VALUES SOME
ACROSS THE EAST. MOIST SOILS WILL ALSO KEEP DEWPOINT READINGS FROM
FALLING TOO FAR BELOW MODEL GUIDANCE. WENT WITH MORE OF A MODEL
BLEND. EITHER WAY...HUMIDITY VALUES FALL BELOW SEASONABLE LEVELS
WED/THUR PRETTY MUCH AREAWIDE. THEN MORE SEASONABLE READINGS
EXCEPT FOR THE FOUR CORNERS BY FRIDAY AND LASTING INTO THE
WEEKEND. LOOKING AT SOME SINGLE DIGIT RH READINGS FOR THE FOUR
CORNERS DURING THE UPCOMING FEW DAYS SO PAY MORE ATTENTION TO FIRE
STARTS UP THAT BECAUSE OF THE DRIER CONDITIONS.
AS FAR AS WETTING RAIN...OVERALL COVERAGE WILL DECREASE PRETTY
SIGNIFICANTLY COMPARED TO THE PAST WEEK. A FEW WETTING STORMS
FAVORING THE EASTERN THIRD TO HALF WILL OCCUR REST OF TODAY BUT
PRETTY ISOLATED. THE DRIER AIR ALOFT WILL KEEP CELLS PRETTY LIMITED
WEDNESDAY. A BAGGY TROUGH OR WEAKNESS TO THE WEST OF THE STATE
WILL EVENTUALLY DRAW SOME MOISTURE NORTHWARD FROM MEXICO AS THE
WEEK PROGRESSES. THIS LOOKS TO BE A SLOW TRANSITION IN TERMS OF
WETTING RAIN COVERAGE BUT THE TRANSITION WILL OCCUR BASED ON MODEL
COMPARISONS THE PAST DAY OR SO AND TAKING INTO ACCOUNT THE TIME OF
YEAR. THE UPPER RIDGE TODAY WILL HAVE SAGGED SOUTHWARD OVER
NORTHERN MEXICO BUT AS THE WEEK PROGRESSES LOOK FOR IT TO TRY TO
STRENGTHEN NORTHWARD AND EVENTUALLY GET SHUNTED EASTWARD DUE TO
THE WESTERN TROUGH. THE NECESSARY DRIVERS OR INGREDIENTS WOULD BE
IN PLACE TO DRAW MONSOONAL MOISTURE NORTHWARD FROM MEXICO. THE
MAIN QUESTION IS HOW QUICKLY.
TEMPERATURES DURING THIS PERIOD WOULD EVENTUALLY WARM SOME BUT
HIGHS WOULD GENERALLY BE NEAR TO SLIGHTLY BELOW NORMAL WEST AND
NEAR TO SLIGHTLY ABOVE NORMAL EAST. OVERALL WIND SPEEDS LOOK TO BE
ON THE LIGHTER SIDE DUE TO THE LACK OF ANY SURFACE OR UPPER LEVEL
DRIVERS. THE STRONGEST WIND FOR THE FORECAST AREA LOOKS TO BE
TODAY AND FAVOR THE EAST. ANY THUNDER CELLS THAT DO DEVELOP COULD
CONTAIN STRONG OUTFLOW WINDS DUE TO THE MID LEVEL/SFC DRYING.
LOOKING AT A RETURN TO SOME HAINES 5/6 VALUES DURING THE NEXT FEW
DAYS. HAINES 6 MOST LIKELY ACROSS THE FOUR CORNERS THURSDAY.
VENTILATION LOOKS TO BE PRETTY DECENT MOST AREAS THROUGH THE END
OF THE WEEK BUT LOWER SOME DURING THE WEEKEND.
GFS/ECMWF SHOWS SOME CONTINUED ATMOSPHERIC MOISTENING DURING THE
WEEKEND INTO EARLY NEXT WEEK AS THE MEAN HIGH PRESSURE CELL
PLACEMENT WOULD BE TO THE EAST OF THE STATE. STILL LOOKING AT A
BAGGY TROUGH TO THE WEST. THUS...THE MONSOONAL MOISTURE PLUME
SHOULD EVENTUALLY CONCENTRATE ITSELF OVER PORTIONS OF AZ/NM. HOW
MUCH AND EXACT PLACEMENT IS STILL A LITTLE TRICKY. ANOTHER FLY IN
THE OINTMENT WOULD BE AN EASTERLY WAVE COMING OFF THE GULF OF
MEXICO. IT IS MOST PROBABLE THAT THIS EASTERLY WAVE WOULD DRAG
DRIER MID LEVEL AIR OVER PORTIONS OF THE FORECAST AREA VERSUS
PROVIDING A MOISTENING TREND BUT HAVE TO WAIT AND SEE. A PRETTY
TYPICAL PERIOD FOR THE WET PHASE OF THE MONSOON SUMMER PERIOD SO
NOTHING REAL UNUSUAL UPCOMING.
50
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
424 AM EDT WED AUG 6 2014
.SYNOPSIS...
A WEAK FRONT WILL MOVE SOUTHWARD ACROSS THE REGION TONIGHT INTO
THURSDAY AND THEN STALL JUST SOUTH OF THE AREA FRIDAY THROUGH THE
UPCOMING WEEKEND. A SERIES OF LOW PRESSURE CENTERS WILL MOVE EAST
ALONG THE FRONT... INCREASING THE CHANCES OF SHOWERS AND
THUNDERSTORMS WITH CONTINUED RAINFALL THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 420 AM EDT...THE LAST VESTIGES OF EARLY MORNING SHOWERS AND
ISOLD TSTMS UNDER A DEPARTING UPPER TROUGH AXIS WILL BE EAST OF OUR
NC PIEDMONT BY DAYBREAK. THIS WILL LEAVE THE REGION IN DEEPER LAYER
NW FLOW FOR THE REMAINDER OF THE NEAR TERM PERIOD. WEAK SFC HIGH
PRES WILL THEN GRADUALLY GIVE WAY TO A COLD FRONT APPROACHING THE
NORTH LATE IN THE DAY. MEANWHILE...LOW LEVEL WESTERLY FLOW SHOULD
PROVIDE SOME DEGREE OF UPSLOPE TRIGGERING ALONG THE WESTERN MTNS BY
18Z TO 21Z IN AND NEAR THE BEST INSTABILITY ACROSS EXTREME ERN TN.
THIS COVERAGE MAY THEN BE MAINTAINED OR POSSIBLY EXPAND EWD ALONG
THE APPROACHING FRONT ACROSS THE NRN TIER THROUGH EARLY THIS
EVENING. SFC BASED INSTABILITY LOOKS QUITE MODEST THIS AFTN AND
EVENING...SO WILL KEEP POPS IN THE LOWER PART OF THE SPECTRUM
INDICATED BY GUIDANCE. SEVERE WX IS NOT ANTICIPATED DESPITE THE
WARMER SFC TEMPS AND RICH DEW POINTS GIVEN THE MEAGER LAPSE RATES
AND LIMITED CAPE AND PERSISTENT CINH.
THE COLD FRONT WILL GRADUALLY SLIDE SWD ACROSS THE REGION
TONIGHT...ACCOMPANIED BY DRYING IN THE NRLY FLOW. EVENING POPS
SHOULD QUICKLY DISSIPATE THROUGH THE OVERNIGHT. THE SLOW FRONTAL
PROGRESS AND RELATIVELY WEAK ADVECTION WILL ALLOW MIN TEMPS TONIGHT
TO REACH VALUES SIMILAR TO RECENT WARM MORNINGS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...HIGH PRESSURE CONTINUES TO RIDGE INTO
THE AREA THU BRINGING IN MIX OF SOMEWHAT LOWER THETA/E AIR. THIS
WILL HELP OFFSET DOWNSLOPE WARMING A BIT AS THE FLOW BECOMES DEEPLY
NW/LY. MAX TEMPS SHOULD BE CLOSE TO NORMAL SRN ZONE AND A FEW
DEGREES BELOW NORMAL NORTH. HIGHER LEVEL CU WILL DEVELOP...BUT
LITTLE INSTABILITY WILL BE HAD FOR MUCH VERTICAL ENHANCEMENT
NON/MTNS. THE SW NC MTNS SHOULD SEE THE BEST CHANCE FOR DEEPER
CONVECTION LATE THU AS UPSLOPE FLOW COMBINES WITH A DIVING POCKET OF
S/W ENERGY. LOW END ELEVATED INSTABILITY WILL CONTINUE
OVERNIGHT...WHICH WILL LIKELY SUPPORT ISOL -SHRA/TSTMS THROUGH
DAYBREAK OVER THE SRN MTNS. A DEVELOPING WEDGE BNDRY WILL WORK INTO
THE AREA OVERNIGHT AND MOIST LLVL SE/LY FLOW SHOULD ACTIVATE AREAS
OF LIGHT PRECIP ACROSS THE WRN UPSTATE AND NE GA THROUGH MID
MORNING.
THE SFC HIGH CENTER POSITIONS ACROSS THE MID ATLANTIC DURING THE DAY
FRI AND THIS WILL MAINTAIN MOIST E/LY FLOW ACROSS THE WEDGE...ENUF
SO FOR HIGH END CHANCE -SHRA POPS ACROSS THE ENTIRE CWFA...FAVORING
HIGHER CHANCES OVER THE MTNS. THE GFS/NAM SOUNDINGS SHOW ENUF
INSTABILITY FOR EMBEDDED THUNDER DURING THE DAY...SO WILL MAINTAIN LOW
END OR ISOL THUNDER THROUGH THE AFTERNOON. THE WEDGE WILL BECOME
LOCKED IN FRI NIGHT AS CONTINUED H85 SW/LY FLOW CONTINUES TO SUPPORT
AN ELEV WARM FRONT. THUS...-SHRA POPS WILL REMAIN HIGH THROUGH THE
MORNING HRS. MAX TEMPS WILL RANGE FROM 6-8 DEGREES BELOW NORMAL
NORTH TO NEAR NORMAL SOUTH. MINS WILL LOCK IN RIGHT AROUND NORMAL OR
A BIT BELOW WITH WIDE COVERAGE PRECIP.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...A SPLIT FLOW PATTERN DEVELOPS OVER THE
WEEKEND...WITH A STRONG RIDGE CENTERED OVER THE ERN CANADA AND NW/LY
FLOW ACROSS THE MID ATL / SE REGION. THIS WILL CREATE A DOWNSTREAM
ULVL CONFLUENT ZONE WHICH IN TURN WILL MAINTAIN A PERSISTENT AND
REINFORCING SFC HIGH OFF THE MID ATL COAST AND A WEDGE RIDGING
PATTERN INTO THE CWFA THROUGH SUN....PERHAPS REMAINING INTO MON.
THE MODELS ARE COMING INTO BETTER AGREEMENT WITH THIS SCENARIO AS
THE GFS AND ECMWF HAVE A SIMILAR LLVL SYNOPTIC PATTERN...HOWEVER THE
LATEST CMC IS STILL HOLDING ONTO THE IDEA OF WEAK RIDGE WITH MORE
UNSTABLE S/LY FLOW. MORE CONFIDENCE IS HAD IN THE GFS/ECMWF SOLNS
AND TRENDS...WHICH AGREE WELL WITH WPC/S DEPICTION OF THE SFC BNDRY
REMAINING SOUTH BECOMING WAVY SUN/MON GENERATING PLENTY OF MOIST
FLOW OVER THE WEDGE.
PWATS BECOME RATHER HIGH SAT INTO SUN...WITH A BLENDED SOUNDING
VALUE OF ABOUT 1.75 INCHES. THERE WILL BE SOME ELEV INSTABILITY WITH
POCKETS OF ULVL ENERGY TRANSITING...BUT WILL GENERALLY EXPECT
STRATIFORM PRECIP WITH RAINFALL AMOUNTS INCREASING GRADUALLY TO
AROUND 2.5 INCHES ERN ZONES WITHIN THE BEST LLVL LIFT SAT THROUGH
SUN. THE MODELS HAVE BEEN PERSISTENT THE PAST FEW RUNS WITH BRINGING
IN A DEFINED H5 S/W SUN NIGHT PRODUCING A SFC REFLECTION STRONG ENUF
TO DISRUPT THE WEDGE PATTERN...THUS DRYING THINGS OUT AS THE SFC
CONVERGENT ZONE IS SHUNTED EAST. THIS IS GIVEN SOME WEIGHT IN THE
FCST WITH POPS DROPPING TO LOW END CHANCE MON...HOWEVER POPS WILL
RETURN TO HIGH END CHANCES TUE AS A PREFRONTAL TROF IS PROGGED TO
MOVE INTO THE AREA. MAX TEMPS THROUGH THE PERIOD WILL REMAIN BELOW
NORMAL BY 8-10 DEGREES F SAT INTO MON...THEN WITH RETURNING S/LY
FLOW TUE MAXES SHOULD REBOUND ABOUT 5-8 DEGREES WARMER.
&&
.AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...EARLY MORNING SHOWERS AND ISOLD TSTMS HAVE MOVED EAST OF
THE AIRFIELD ALONG WITH THE DRIVING UPPER TROUGH AXIS. RAP PROFILES
STILL SHOW SOME WORRISOME MOISTURE NEAR THE SFC...AND WITH THE
RECENT SHOWERS THAT MOVED THROUGH WILL ADVERTISE TEMPO MVFR VSBY IN
LIGHT FOG. HOWEVER...WILL STAY THE COURSE OF THE GUIDANCE AND THE
PREVIOUS FORECAST IN KEEPING THE AIRFIELD FREE OF LOW CLOUDS GIVEN
THE ABSENCE OF ANY STRATUS NEARBY. EXPECT MAINLY LIGHT NRLY FLOW
EARLY...BECOMING MORE WESTERLY THROUGH THE DAY...AND THEN TURNING NW
TO NRLY AGAIN TONIGHT WITH THE APPROACHING FRONT. ANY AFTN MTN
CONVECTION SHOULD STRUGGLE TO REACH THE PIEDMONT THIS EVENING WITH
SUCH LIMITED CAPE IN MODEL PROFILES.
ELSEWHERE...LIFR CONDITIONS HAVE ALREADY SET UP AT KAVL...BUT THIS
WILL REMAIN VARIABLE GIVEN THE MID AND HIGH CLOUDS ARRIVING IN NW
FLOW ALOFT. AT LEAST TEMPO LIFR CONDITIONS ARE EXPECTED THROUGH 12Z.
CONDITIONS SHOULD BE FREE OF RESTRICTIONS THIS MORNING AT THE
FOOTHILL TAF SITES EXCEPT FOR BRIEF MVFR FOG AT KHKY ONCE THE MID
CLOUDS DISSIPATE. EXPECT LIGHT NW FLOW TODAY TO BECOME MORE WESTERLY
AT THE FOOTHILL SITES THIS AFTN BEFORE RETURNING TO NW TONIGHT AS A
COLD FRONT APPROACHES. WILL MENTION LATE DAY VCSH AT KAVL AND KHKY
CLOSER TO THE MTN TRIGGERING AND APPROACHING FRONT.
OUTLOOK...MOSTLY DRY CONDITIONS SHOULD CONTINUE IN THE HIGH PRES
BEHIND THE FROPA ON THU BEFORE MOISTURE RETURNS FROM THE LOW PRES TO
THE WEST ON FRI. A PERSISTENT MOIST CAD PATTERN WILL SET UP FRI
THROUGH THE WEEKEND TO GENERATE WIDESPREAD RESTRICTIONS WITH LOW
CLOUDS AND RAIN. THESE CONDITIONS MAY BE VERY SLOW TO CLEAR INTO
EARLY NEXT WEEK.
CONFIDENCE TABLE...
08-14Z 14-20Z 20-02Z 02-08Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 67% HIGH 100% HIGH 100% HIGH 90%
KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% 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...HG
NEAR TERM...HG
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...HG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
243 AM EDT WED AUG 6 2014
.SYNOPSIS...
A WEAK FRONT WILL MOVE SOUTHWARD ACROSS THE REGION TONIGHT INTO
THURSDAY AND THEN STALL JUST SOUTH OF THE AREA FRIDAY THROUGH THE
UPCOMING WEEKEND. A SERIES OF LOW PRESSURE CENTERS WILL MOVE EAST
ALONG THE FRONT... INCREASING THE CHANCES OF SHOWERS AND
THUNDERSTORMS WITH CONTINUED RAINFALL THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 215 AM EDT...AN UPPER TROUGH AXIS PULLING EAST OF THE FORECAST
AREA EARLY THIS MORNING WILL LEAVE THE REGION IN DEEP LAYER NW FLOW
FOR THE REMAINDER OF THE PERIOD. A FEW EARLY MORNING SHOWERS...WITH
AN ISOLD THUNDERSTORM...WILL BE POSSIBLE AROUND THE CHARLOTTE METRO
AREA UNTIL THE TROUGH CLEARS THE REGION BY DAYBREAK. WEAK SFC HIGH
PRES WILL THEN GRADUALLY GIVE WAY TO A COLD FRONT APPROACHING THE
NORTH LATE IN THE DAY. MEANWHILE...LOW LEVEL WESTERLY FLOW SHOULD
PROVIDE SOME DEGREE OF UPSLOPE TRIGGERING ALONG THE WESTERN MTNS BY
18Z TO 21Z IN AND NEAR THE BEST INSTABILITY ACROSS EXTREME ERN TN.
THIS COVERAGE MAY THEN BE MAINTAINED OR POSSIBLY EXPAND EWD ALONG
THE APPROACHING FRONT ACROSS THE NRN TIER THROUGH EARLY THIS
EVENING. SFC BASED INSTABILITY LOOKS QUITE MODEST THIS AFTN AND
EVENING...SO WILL KEEP POPS IN THE LOWER PART OF THE SPECTRUM
INDICATED BY GUIDANCE. SEVERE WX IS NOT ANTICIPATED DESPITE THE
WARMER SFC TEMPS AND RICH DEW POINTS GIVEN THE MEAGER LAPSE RATES
AND LIMITED CAPE AND PERSISTENT CINH.
THE COLD FRONT WILL GRADUALLY SLIDE SWD ACROSS THE REGION
TONIGHT...ACCOMPANIED BY DRYING IN THE NRLY FLOW. EVENING POPS
SHOULD QUICKLY DISSIPATE THROUGH THE OVERNIGHT. THE SLOW FRONTAL
PROGRESS AND RELATIVELY WEAK ADVECTION WILL ALLOW MIN TEMPS TONIGHT
TO REACH VALUES SIMILAR TO RECENT WARM MORNINGS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 200 AM EDT WEDNESDAY...HIGH PRESSURE CONTINUES TO RIDGE INTO
THE AREA THU BRING IN MIX OF SOMEWHAT LOWER THETA/E AIR. THIS WILL
HELP OFFSET DOWNSLOPE WARMING A BIT AS FLOW BECOMES DEEPLY NW/LY.
MAX TEMPS SHOULD BE CLOSE TO NORMAL SRN ZONE AND A FEW DEGREES BELOW
NORMAL NORTH. HIGHER LEVEL CU WILL DEVELOP...BUT LITTLE INSTABILITY
WILL BE HAD FOR MUCH VERTICAL ENHANCEMENT NON/MTNS. THE SW NC MTNS
SHOULD SEE THE BEST CHANCE FOR DEEPER CONVECTION LATE AS UPSLOPE
FLOW COMBINES WITH A DIVING POCKET OF S/W ENERGY. LOW END ELEVATED
INSTABILITY WILL CONTINUE OVERNIGHT...WHICH WILL LIKELY SUPPORT ISOL
-SHRA/TSTMS THROUGH DAYBREAK OVER THE SRN MTNS. A DEVELOPING WEDGE
BNDRY WILL WORK INTO THE AREA OVERNIGHT AND MOIST LLVL SE/LY FLOW
SHOULD ACTIVATE AREAS OF LIGHT PRECIP ACROSS THE WRN UPSTATE AND NE
GA THROUGH MID MORNING.
THE SFC HIGH CENTER POSITIONS ACROSS THE MID ATLANTIC DURING THE DAY
FRI AND THIS WILL MAINTAIN MOIST E/LY FLOW ACROSS THE WEDGE...ENUF
SO FOR HIGH END CHANCE -SHRA POPS ACROSS THE ENTIRE CWFA...FAVORING
HIGHER CHANCES OVER THE MTNS. THE GFS/NAM SOUNDINGS SHOW ENUF
INSTABILITY FOR EMBEDDED THUNDER DURING THE DAY...SO WILL MAINTAIN LOW
END OR ISOL THUNDER THROUGH THE AFTERNOON. THE WEDGE WILL BECOME
LOCKED IN FRI NIGHT AS CONTINUED H85 SW/LY FLOW CONTINUES TO SUPPORT
AN ELEV WARM FRONT. THUS...-SHRA POPS WILL REMAIN HIGH THROUGH THE
MORNING HRS. MAX TEMPS WILL RANGE FROM 6-8 DEGREES BELOW NORMAL
NORTH TO NEAR NORMAL SOUTH. MINS WILL LOCK IN RIGHT AROUND NORMAL OR
A BIT BELOW WITH WIDE COVERAGE PRECIP.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 235 AM WEDNESDAY...A SPLIT FLOW PATTERN DEVELOPS OVER THE
WEEKEND...WITH A STRONG RIDGE CENTERED OVER THE ERN CANADA AND NW/LY
FLOW ACROSS THE MID ATL / SE REGION. THIS WILL CREATE A DOWNSTREAM
ULVL CONFLUENT ZONE WHICH IN TURN WILL MAINTAIN A PERSISTENT AND
REINFORCING SFC HIGH OFF THE MID ATL COAST AND A WEDGE RIDGING
PATTERN INTO THE CWFA THROUGH SUN....PERHAPS REMAINING INTO MON.
THE MODELS ARE COMING INTO BETTER AGREEMENT WITH THIS SCENARIO AS
THE GFS AND ECMWF HAVE A SIMILAR LLVL SYNOPTIC PATTERN...HOWEVER THE
LATEST CMC IS STILL HOLDING ONTO THE IDEA OF WEAK RIDGE WITH MORE
UNSTABLE S/LY FLOW. MORE CONFIDENCE IS HAD IN THE GFS/ECMWF SOLNS
AND TRENDS...WHICH AGREE WELL WITH WPC/S DEPICTION OF THE SFC BNDRY
REMAINING SOUTH BECOMING WAVY SUN/MON GENERATING PLENTY OF MOIST
FLOW OVER THE WEDGE.
PWATS BECOME RATHER HIGH SAT INTO SUN...WITH A BLENDED SOUNDING
VALUE OF ABOUT 1.75 INCHES. THERE WILL BE SOME ELEV INSTABILITY WITH
POCKETS OF ULVL ENERGY TRANSITING...BUT WILL GENERALLY EXPECT
STRATIFORM PRECIP WITH RAINFALL AMOUNTS INCREASING GRADUALLY TO
AROUND 2.5 INCHES ERN ZONES WITHIN THE BEST LLVL LIFT SAT THROUGH
SUN. THE MODELS HAVE BEEN PERSISTENT THE PAST FEW RUNS WITH BRINGING
IN A DEFINED H5 S/W SUN NIGHT PRODUCING A SFC REFLECTION STRONG ENUF
TO DISRUPT THE WEDGE PATTERN...THUS DRYING THINGS OUT AS THE SFC
CONVERGENT ZONE IS SHUNTED EAST. THIS IS GIVEN SOME WEIGHT IN THE
FCST WITH POPS DROPPING TO LOW END CHANCE MON...HOWEVER POPS WILL
RETURN TO HIGH END CHANCES TUE AS A PREFRONTAL TROF IS PROGGED TO
MOVE INTO THE AREA. MAX TEMPS THROUGH THE PERIOD WILL REMAIN BELOW
NORMAL BY 8-10 DEGREES F SAT INTO MON...THEN WITH RETURNING S/LY
FLOW TUE MAXES SHOULD REBOUND ABOUT 5-8 DEGREES WARMER.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
AT KCLT...A FEW SHOWERS WILL CONTINUE IN THE VICINITY EARLY THIS
MORNING UNTIL AN UPPER TROUGH AXIS CLEARS THE REGION TO THE EAST.
TOWERS ARE JUST HIGH ENOUGH TO SUPPORT SOME LIGHTNING...SO A BRIEF
TEMPO FOR TSRA WILL BE INCLUDED THROUGH 07Z. RAP PROFILES HAVE SOME
WORRISOME NEAR SFC MOISTURE AGAIN THIS MORNING...BUT WILL STAY THE
COURSE OF THE GUIDANCE AND THE PREVIOUS FORECAST IN KEEPING THE
AIRFIELD FREE OF RESTRICTIONS...ESPECIALLY WITH SOME MID LEVEL
DEBRIS CLOUDS AROUND EARLY. EXPECT MAINLY LIGHT NRLY FLOW
EARLY...BECOMING MORE WESTERLY THROUGH THE DAY...AND THEN TURNING NW
TO NRLY AGAIN TONIGHT WITH THE APPROACHING FRONT. ANY AFTN MTN
CONVECTION SHOULD STRUGGLE TO REACH THE PIEDMONT THIS EVENING WITH
SUCH LIMITED CAPE IN MODEL PROFILES.
ELSEWHERE...LIFR CONDITIONS HAVE ALREADY SET UP AT KAVL AT ISSUANCE
TIME...BUT THEY COULD BE VARIABLE ONCE AGAIN GIVEN THE MID AND HIGH
CLOUDS ARRIVING IN NW FLOW ALOFT. AT LEAST TEMPO LIFR CONDITIONS ARE
EXPECTED THROUGH 12Z. CONDITIONS SHOULD BE FREE OF RESTRICTIONS THIS
MORNING AT THE FOOTHILL TAF SITES EXCEPT FOR BRIEF MVFR AT KHKY ONCE
THE MID CLOUDS DISSIPATE. EXPECT LIGHT NW FLOW TODAY TO BECOME MORE
WESTERLY AT THE FOOTHILL SITES THIS AFTN BEFORE RETURNING TO NW
TONIGHT AS A COLD FRONT APPROACHES. WILL MENTION LATE DAY VCSH AT
KAVL AND KHKY CLOSER TO THE MTN TRIGGERING AND APPROACHING FRONT.
OUTLOOK...MOSTLY DRY CONDITIONS SHOULD CONTINUE IN THE HIGH PRES
BEHIND THE FROPA ON THU BEFORE MOISTURE RETURNS FROM THE LOW PRES TO
THE WEST ON FRI. A PERSISTENT MOIST CAD PATTERN WILL SET UP FRI
THROUGH THE WEEKEND TO GENERATE WIDESPREAD RESTRICTIONS WITH LOW
CLOUDS AND RAIN. THESE CONDITIONS MAY BE VERY SLOW TO CLEAR INTO
EARLY NEXT WEEK.
CONFIDENCE TABLE...
06-12Z 12-18Z 18-24Z 00-06Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 71% HIGH 92% HIGH 100% HIGH 100%
KHKY HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% 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...HG
NEAR TERM...HG
SHORT TERM...SBK
LONG TERM...SBK
AVIATION...HG
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
348 AM CDT WED AUG 6 2014
.DISCUSSION...
HAVING A BIT OF A CONUNDRUM IN REGARDS TO STORMS. ATMOSPHERE WILL
BE POTENTIALLY UNSTABLE IN THE AFTERNOON...BUT THERE REALLY IS NO
GREAT FORCING. TODAY...4KM WRF IS GOING FOR BROKE WITH A LINE OF
STORMS ACROSS OKLAHOMA STRETCHING SOUTH INTO NORTHWEST NORTH
TX...BUT IT IS WAY MORE AGGRESSIVE THAN OTHER MODELS. WRF ARW
DEVELOPS ISOLATED CONVECTION IN THE METROPLEX...BUT AGAIN NOT
SUPPORTED BY OTHER MODELS. FORECAST SOUNDINGS SHOW MOISTURE IS
MORE SHALLOW TODAY THAN YESTERDAY. THE RAP FORECASTS AN UNSTABLE
ATMOSPHERE WITH 450 J/KG CAPE...BUT DOES NOT DEVELOP STORMS.
FOR THURSDAY...A SHORT WAVE MOVES ACROSS THE CENTRAL PLAINS...BUT
THE NAM DEVELOPS SOME CONVECTION IN WESTERN ZONES AND DRIVES IT
SOUTH DURING THE AFTERNOON. THE TTU WRF PLACES A SMALL CONNECTIVE
CLUSTER IN YOUNG/STEPHENS COUNTIES...BUT AGAIN ACTIVITY IS NOT
SUPPORTED BY OTHER MODELS.
I HAVE OPTED TO KEEP ISOLATED STORMS IN THE SOUTHEAST AND ADDED
ISOLATED STORMS IN THE NORTHWEST TODAY. WILL NOT ADD ANY PRECIP
THROUGH THE REST OF THE FORECAST BUT MAY HAVE TO BUMP SOME AREAS
UP TO LOW CHANCES TONIGHT IF THURSDAY LOOKS ANY WETTER.
TEMPERATURES ARE GOING TO CLIMB SLOWLY AS THE RIDGE BUILDS
IN...AND HAVE NUMEROUS AREAS WITH TRIPLE DIGITS BY SUNDAY. 84
&&
.AVIATION...
/ISSUED 1205 AM CDT WED AUG 6 2014/
/06Z TAFS/
VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH THE PERIOD. SOME
LIGHT FOG WILL BE POSSIBLE AGAIN BETWEEN 10-14Z BUT THE HIGH
CLOUDS OVER THE REGION MAY PREVENT GOOD RADIATIONAL COOLING
TONIGHT AND SLIGHTLY HIGHER WIND SPEEDS MAY ALSO PREVENT FOG FROM
DEVELOPING. HOWEVER...WILL TEMPO FOR 6SM BR AT KDFW AND KDAL
WHERE IT RAINED THIS EVENING AND LOW LEVEL MOISTURE IS HIGHER THAN
SURROUNDING SITES. OTHERWISE...SOUTH TO SOUTHEAST WINDS WILL
PREVAIL THROUGH THE PERIOD AT SPEEDS LESS THAN 12 KTS. ISOLATED
SHOWERS AND STORMS ARE POSSIBLE AGAIN WEDNESDAY AFTERNOON BUT THE
CHANCE IS TOO SMALL TO MENTION IN THE TAFS.
82/JLD
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 78 98 78 99 / 10 10 10 10 10
WACO, TX 97 76 98 75 98 / 10 10 10 10 5
PARIS, TX 92 73 94 74 95 / 10 10 10 10 10
DENTON, TX 95 76 95 77 97 / 10 10 10 10 10
MCKINNEY, TX 95 75 96 76 97 / 10 10 10 10 10
DALLAS, TX 97 78 98 78 99 / 10 10 10 10 10
TERRELL, TX 97 75 97 75 98 / 10 10 10 10 10
CORSICANA, TX 96 74 95 75 97 / 10 10 10 10 10
TEMPLE, TX 95 74 96 74 97 / 10 10 10 10 5
MINERAL WELLS, TX 98 75 99 75 98 / 10 10 10 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1147 PM CDT TUE AUG 5 2014
.AVIATION...
VFR CONDITIONS SHOULD PREVAIL FOR THE NEXT 24 HOURS. SOUTHERLY
SURFACE WINDS MAY BECOME A BIT GUSTY AROUND SUNRISE AS MIXING TAPS
INTO THE LOW-LEVEL JET. HIGH-BASED CUMULUS FIELD EXPECTED TO
DEVELOP BY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 937 PM CDT TUE AUG 5 2014/
UPDATE...
AT 920 PM...A SMALL T-STORM COMPLEX WAS MOVING SE OUT OF NE NM INTO
THE WRN TX PANHANDLE. THE LOW-LEVEL JET IS A LITTLE STRONGER THAN
PREVIOUS NIGHTS...BUT INSTABILITY AND MID-LVL FLOW IS NOT VERY
SUPPORTIVE FOR SUSTAINING THIS ACTIVITY AS FAR AS OUR CWA TONIGHT.
THE HRRR SUGGESTS THAT WE COULD SEE SOME DECAYING SHOWERS ARRIVE
IN NORTHERN PORTIONS OF PARMER...CASTRO AND SWISHER COUNTIES
AROUND 1 TO 2 AM. FOR NOW 10 PERCENT POPS IN THIS AREA SHOULD
SUFFICE AND WE/LL CONTINUE TO MONITOR THE STORMS. OTHERWISE...SOME
MINOR ADJUSTMENTS MADE TO WIND AND SKY COVER GRIDS.
PREV DISCUSSION... /ISSUED 639 PM CDT TUE AUG 5 2014/
AVIATION...
VFR CONDITIONS ARE EXPECTED AT BOTH TERMINALS FOR THE NEXT 24
HOURS. VARIABLE CLOUDINESS ABOVE APPROX. 7K FT IS EXPECTED ALONG
WITH SRLY SFC WINDS...WHICH WILL BECOME A BIT BREEZY AROUND DAYBREAK.
PREV DISCUSSION... /ISSUED 350 PM CDT TUE AUG 5 2014/
SHORT TERM...
HIGH PRESSURE REMAINS IN CONTROL OVER THE SOUTHERN STATES WITH SOME
MONSOONAL MOISTURE PRESENT ACROSS CENTRAL NEW MEXICO. WITH THE
LIGHT ANTI-CYCLONIC FLOW....STORMS SHOULD GENERALLY REMAIN WELL
WEST OF THE AREA THOUGH AN AREA OF WEAK CONVERGENCE HAS SET UP
ACROSS THE NORTHWESTERN ZONES. A FEW PINHEAD SHOWERS HAVE
ATTEMPTED TO GET GOING AND THERE REMAINS SOME LOW PROBABILITIES OF
AN HONEST THUNDERSTORM TO GET GOING...CONFIDENCE REMAINS LOW FOR
ANYTHING SIGNIFICANT TO GET GOING. TEMPERATURES TONIGHT WILL BE
FAIRLY TYPICAL OF THIS TIME OF YEAR WITH A HOTTER WEDNESDAY AS
SKIES BECOME A BIT LESS OBSCURED. THUS...WE WILL CALL FOR HIGHS UP
NEAR THE CENTURY MARK.
LONG TERM...
FAVORABLE CHANCES FOR CONVECTION WILL MOSTLY BE LIMITED TO NEW
MEXICO AND THE PANHANDLES. A COLD FRONT WILL ATTEMPT TO MAKE A RUN
AT THE AREA ON THURSDAY BUT STOPS SHORT BEFORE DISSIPATING. THE
CENTER OF THE UPPER RIDGE WILL BE CLOSE TO OVERHEAD BY FRIDAY WITH A
WEAK SHORT WAVE MOVING THROUGH CENTRAL NEW MEXICO. THIS SHORT WAVE
LOOKS TO BE TOO FAR AWAY TO HAVE ANY CONVECTION IMPACT ON WEST
TEXAS. CONVECTION WILL LIKELY BE LIMITED TO THE WEST AND NORTH OF
THE REGION THIS WEEKEND AS THE RIDGE SHIFTS A LITTLE MORE TO THE
SOUTH AND EAST. THE RIDGE WILL SHIFT BACK WEST NEXT WEEK ALLOWING
FOR STRONGER NORTHWEST FLOW AND POSSIBLY A FEW FRONTS TO ENCROACH BY
THE MIDDLE OF NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
FRIONA 63 96 64 96 65 / 10 0 10 10 10
TULIA 65 97 67 98 66 / 10 10 10 10 10
PLAINVIEW 66 97 66 96 66 / 0 0 10 10 10
LEVELLAND 66 98 67 97 66 / 0 0 0 10 10
LUBBOCK 70 99 70 98 69 / 0 0 0 10 10
DENVER CITY 65 97 66 97 66 / 0 0 0 10 0
BROWNFIELD 66 99 67 97 66 / 0 0 0 10 0
CHILDRESS 70 100 72 101 72 / 0 10 10 10 10
SPUR 68 101 70 100 69 / 0 0 0 10 0
ASPERMONT 72 101 73 100 72 / 0 10 0 10 0
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1137 PM CDT TUE AUG 5 2014
.DISCUSSION...
SEE 06Z AVIATION DISCUSSION.
40
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED AT MOST OF THE SITES. THE EXCEPTION
WILL IS OVER KCXO AND KUTS WHERE MVFR CONDITIONS ARE POSSIBLE
THROUGH ABOUT 13Z. THE SEABREEZE IS ALSO EXPECTED TO BECOME
ACTIVE. AN UPPER LEVEL TROUGH NEAR THE COAST WILL AID IN THE
DEVELOPMENT OF ISOLATED SHOWERS AROUND 12Z. AS THE SEABREEZE WORKS
ITS WAY INLAND...ISOLATED SHOWERS AND THUNDERSTORMS ARE POSSIBLE
THROUGH THE AFTERNOON OVER THE INLAND SITES.
40
&&
.PREV DISCUSSION... /ISSUED 932 PM CDT TUE AUG 5 2014/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
HIGH PRESSURE WAS OVER THE EASTERN GULF AND A WEAK AREA OF LOW
PRESSURE WAS NOTED OVER SE COLORADO. A WEAK SURFACE TROUGH
EXTENDED FROM ABOUT KLFK TO KCOT. AT THE 850-700 LAYER...A RIBBON
OF SLIGHTLY DEEPER MOISTURE EXTENDS FROM NE TEXAS TO SOUTHERN
LOUISIANA WITH A WEAK S/WV NOTED FROM ABOUT SAN LUIS PASS TO
COLLEGE STATION. AT THE UPPER LEVELS...A WELL DEVELOPED UPPER
LEVEL HIGH WAS LOCATED OVER NE SONORA IN MEXICO. THE HIGH HAS
EXPANDED SINCE LAST EVENING AND NOW EXTENDS INTO EASTERN TEXAS.
GFS MASS FIELDS STILL SUPPORT RAIN CHANCE FOR WEDNESDAY WHILE
OTHER GLOBAL MODELS ARE TRENDING DRIER. PW VALUES ARE PROGGED TO
FALL TO BETWEEN 1.4 AND 1.6 INCHES FROM THIS AFTERNOONS VALUE OF
AROUND 1.80 INCHES. THE RAP AND 4KM NCEP WRF ARE TRENDING DRIER
AND SUPPORT THE NAM/ECMWF. STILL FEEL SHRA WILL BE POSSIBLE ON
WEDNESDAY BUT COVERAGE SHOULD BE CONSIDERABLY MORE ISOLATED THAN
TODAY.
SHRA/TSRA ARE WANING QUICKLY WITH THE LOSS OF HEATING AND NOT
EXPECTING MUCH IN THE WAY OF ADDITIONAL ACTIVITY OVERNIGHT. WILL
ISSUE NEW ZONES TO CLEAN UP EVENING WORDING...REMOVE POPS ETC...
43
CLIMATE...
SOME INTERESTING CLIMATE STATS TO BANTER ABOUT THIS EVENING.
COLLEGE STATION HAS RECORDED ONLY 11 DAYS WITH TEMPERATURES AT OR
ABOVE 95 DEGREES IN 2014. TYPICALLY...COLLEGE STATION HAS RECORDED
30 SUCH DAYS BY AUGUST 5TH (1981-2010). HOUSTON HAS ONLY RECORDED
9 DAYS WITH TEMPS AT OR ABOVE 95 DEGREES BUT TYPICALLY WOULD HAVE
TALLIED 26 SUCH DAYS BY THE 5TH.
SINCE THE SUMMER HAS BEEN COOL BY TEXAS STANDARDS...THOUGHT IT
MIGHT BE INTERESTING TO SEE HOW MANY DAYS HAVE BEEN BELOW NORMAL
SINCE JUNE 1ST. COLLEGE STATION HAS RECORDED 30 DAYS OF BELOW
NORMAL TEMPERATURES AND 10 DAYS OF NORMAL TEMPERATURES SINCE JUNE
1ST OR 40 OUT OF 66 DAYS WITH NORMAL OR BELOW NORMAL TEMPERATURES.
WHAT A DIFFERENCE FROM THE SUMMER OF 2011. HOUSTON RECORDED 29
DAYS BELOW NORMAL AND 14 DAYS AT NORMAL OR 43 OUT OF 66 DAYS AT OR
BELOW NORMAL.
ONE LAST TIDBIT...COLLEGE STATION AND HOUSTON HAVE YET TO RECORD A
RECORD HIGH TEMPERATURE SO FAR THIS YEAR. HOUSTON RECORDED IT`S
LAST HIGH TEMPERATURE RECORD ON NOVEMBER 17 2013 AND COLLEGE
STATION HAS NOT RECORDED A HIGH TEMPERATURE RECORD SINCE JULY 13
2013 - OVER A YEAR AGO. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 95 77 96 77 / 10 20 10 10 10
HOUSTON (IAH) 76 95 77 95 77 / 10 20 10 20 10
GALVESTON (GLS) 80 91 81 91 81 / 20 20 20 20 10
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
330 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING THE AREA UNDER A
GENERAL TROUGH ALOFT WITH RIDGING OVER THE CENTRAL AND NORTHERN
PLAINS. GOOD PLUME OF SUBTROPICAL MOISTURE SURGING NORTHWARD ACROSS
THE PLAINS WITH A WEAK SHORTWAVE TROUGH AND MID-LEVEL FRONTOGENESIS
FUELING A BAND OF SHOWERS/THUNDERSTORMS ACROSS EASTERN ND/NEB...INTO
WESTERN AND CENTRAL IA. CLOSER IN...THE ARX FORECAST AREA WAS MOSTLY
CLEAR EAST OF THE MISSISSIPPI WITH WEAK TO CALM SURFACE WIND. THIS
WAS ALLOWING SOME FOG TO SET UP ACROSS PORTIONS OF CENTRAL WI AND IN
THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. TEMPERATURES EARLY THIS
MORNING RANGED FROM THE MIDDLE 50S TO THE LOWER 60S.
FOR TODAY...SURFACE HIGH PRESSURE WILL HOLD OVER THE GREAT LAKES
REGION AS A MID-LEVEL SHORTWAVE TROUGH BUDGES EASTWARD FROM THE
CENTRAL PLAINS INTO WESTERN IA. MODELS IN PRETTY GOOD AGREEMENT
SHOWING ASSOCIATED SHOWERS/ISOLATED THUNDER JUST NIPPING PARTS OF
NORTHEAST IA BY NOON. DURING THE AFTERNOON DRIER AIR OUTFLOW FROM
THE GREAT LAKES HIGH LOOKS TO HALT ANY FARTHER NORTHEAST PUSH OF
THIS SHOWER/ISOLATED THUNDER ACTIVITY. IN FACT...APPEARS SOME OF
THIS RAIN MAY RETREAT FARTHER SOUTHWEST AN MAYBE ENTIRELY OUT OF OUR
AREA. OTHERWISE...PLAN ON PARTLY SUNNY SKIES EAST OF THE MISSISSIPPI
RIVER WITH CLOUD COVER DOMINATING WEST OF THE RIVER. HIGHS TODAY
EXPECTED TO TOP OFF IN THE 70S.
FOR TONIGHT INTO THURSDAY...MODELS COMING IN CLOSER AGREEMENT WITH
FAIRLY VIGOROUS MID-LEVEL TROUGH DROPPING THROUGH THE DAKOTAS INTO
THE MID/UPPER MISSISSIPPI RIVER VALLEY REGION. NAM STILL SHOWING
STRONG 850-500MB FRONTOGENESIS WITH THIS WAVE MOVING ALONG AND SOUTH
OF I-90 MAINLY DURING THE DAY THURSDAY. THE GFS IS SLIGHTLY FASTER
WITH THE WAVE COMPARED TO THE NAM/ECMWF/GEM AND HAS WEAKER
FRONTOGENESIS FOCUSED MORE ACROSS IA/IL. SINCE GFS SEEMS TO BE THE
ODD MODEL OUT...RAISED POPS TO HONOR MORE THE GFS/ECMWF/GEM MORE
NORTHERN SOLUTIONS. BTW...NOT MUCH CAPE INVOLVED WITH THIS WAVE...SO
TAPERED THUNDER TO ISOLATED MENTION GIVEN FORCING SIGNAL.
WILL HAVE TO CONTINUE WATCHING THE EVOLUTION/RAIN POTENTIAL OF THIS
SYSTEM AS IT IS ALWAYS A BIT TRICKY GIVEN DRY LOWER LEVEL OUTFLOW
FROM GREAT LAKES HIGH PRESSURE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
FOR THURSDAY NIGHT INTO FRIDAY...NAM/ECMWF/GEM SHOW SOME LINGERING
DEFORMATION SHOWERS AND ISOLATED THUNDER FOCUSED MAINLY ALONG AND
SOUTH OF I-90. CARRIED LOWER-END POPS TO COVER THIS.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOK DRY AS MIDDLE LEVEL RIDGE
DRIFTS OVERHEAD.
SHOWER/THUNDERSTORM CHANCES RETURN TO THE AREA SUNDAY LASTING
THROUGH TUESDAY AS A COLD FRONT MOVES THROUGH AND COOLER CYCLONIC
FLOW ALOFT LINGERS.
TEMPERATURES FRIDAY THROUGH THE PERIOD LOOK RIGHT AROUND NORMAL
LEVELS WITH DAYTIME READINGS IN THE UPPER 70S TO THE LOWER 80S AND
IN THE UPPER 50S/LOWER 60S AT NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1100 PM CDT TUE AUG 5 2014
CONCERN CONTINUES TO FOCUS ON THE FOG POTENTIAL...ESPECIALLY IN THE
MISSISSIPPI RIVER VALLEY. T/TD SPREAD AT 03Z FOR KLSE WAS 4 DEGREES
WITH LIGHT/CALM SFC WINDS AND A LIGHT VERTICAL WIND LAYER PER BUFKIT
SOUNDINGS - UPWARDS OF 4K FT. ALL VERY FAVORABLE FOR 1/4SM FOG AT
KLSE. THE ONE HOLD BACK IS THE PERSIST FEED OF VARIABLE UPPER LEVEL
CLOUDINESS FROM CONVECTION TO THE WEST/SOUTHWEST. IF THIS WOULD
THICKEN AND BECOME MORE WIDESPREAD TOWARD 12Z...IT COULD SERVE AS
ENOUGH OF AN INHIBITOR TO DETER A DROP BELOW 1-2SM. IF ITS MORE
SKC/SKC THOUGH...CONFIDENCE LEANS TOWARD AN HOUR...MAYBE TWO OF
1/4SM. LEANING TOWARD ADDING 1/4SM TEMPO IN THE 12-14Z TIME FRAME
FOR NOW. FOR KRST...THE CLOUDS COULD ALSO PUT A DAMPER ON THE MVFR
VSBY POTENTIAL...BUT WITH HOLD WITH A FEW HOURS FOR NOW.
AFTER THIS MORNING FOG POTENTIAL...ANTICIPATE SOME HIGH CLOUDS AND
VFR CONDITIONS INTO WEDNESDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
725 AM EDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT WED AUG 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE GREAT LKS BTWN STUBBORN CLOSED LO OVER QUEBEC AND MEAN UPR RDG
EXTENDING FM SCENTRAL CANADA SWD THRU THE PLAINS. A SHRTWV EMBEDDED
IN THIS NNW FLOW IS DIGGING TOWARD WRN LK SUP AND SUPPORTING A
CLUSTER OF SHOWERS OVER THE WRN LK EARLY THIS MRNG. BUT CLD TOP
TEMPS ARE TENDING TO WARM/SHOWERS WEAKEN A BIT WITH NOCTURNAL
COOLING AND AS THE PCPN AREA MOVES INTO A MORE STABLE ENVIRONMENT
OVER UPR MI REPRESENTED BY THE 00Z GRB RAOB. BEHIND THIS CLD
CLUSTER...SKIES ARE MOCLR OVER NW ONTARIO UNDER AREA OF MID LVL DRY
AIR ASSOCIATED WITH DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE
DIGGING SHRTWV AND SFC HI PRES. ANOTHER SHRTWV IS PRESENT OVER SRN
SASKATCHEWAN MOVING E THRU THE MEAN UPR RDG.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH THE
HI PRES IN NW ONTARIO FCST TO DOMINATE IN THE WAKE OF SHRTWV THAT WL
BE CROSSING THE UPR LKS THIS MRNG.
TODAY...LINGERING SHOWERS OVER WRN UPR MI AND BAND OF CLDS
ASSOCIATED WITH DIGGING SHRTWV WL CROSS UPR MI EARLY THIS MRNG.
APRCH OF SHRTWV RDG/RISING HGTS/DNVA/MID LVL DRYING IN THE WAKE OF
THIS DISTURBANCE WL CAUSE CONDITIONS TO TURN MOSUNNY WITH ONLY SOME
DIURNAL CU AS SFC HI PRES BLDS OVER UPR MI. FCST H85 TEMPS AS HI AS
14C OVER WRN UPR MI WL ALLOW MAX TEMPS TO PEAK NEAR 80 AWAY FM LK
MODERATION...WHICH WL OCCUR PRIMARILY DOWNWIND OF LK SUP UNDER
SYNOPTIC N H925 FLOW IN THE WAKE OF DEPARTING SHRTWV THAT WL
ACCENTUATE THE INLAND PENETRATION OF LK BREEZES OFF THE BIG LK. THE
00Z REGIONAL CNDN MODEL DOES GENERATE SOME ISOLD SHOWERS ALONG LK
BREEZE BNDRYS...BUT WL MAINTAIN GOING DRY FCST GIVEN THE NEGATIVE
DYNAMICS/LARGER SCALE DRYING AND ABSENCE OF QPF FM OTHER GUIDANCE.
COOLING NEAR LK MI WL BE MORE LOCALIZED. MIN AFTN RH WL DROP AS LO
AS 30-35 PCT OVER THE INTERIOR W HALF WITH DAYTIME MIXING OF
INCOMING DRIER AIR THAT WL CAUSE SFC DEWPTS TO FALL OFF INTO THE UPR
40S THIS AFTN. WINDS SHOULD BE NO HIER THAN ABOUT 10 MPH AWAY FM LK
BREEZES...ALLEVIATING FIRE WX CONCERNS. THERE COULD BE GUSTIER WINDS
BEHIND THE LK BREEZE BNDRYS OFF LK SUP...BUT THE AIR WL BE MOISTER
THERE.
TNGT...SFC HI PRES IS FCST TO MOVE OVHD UNDER BLDG UPR RDG. IN THE
PRESENCE OF PWAT FALLING TOWARD 0.5 INCH /40-50 PCT OF NORMAL/...
MOCLR SKIES AND LGT WINDS...EXPECT A HEALTHY DIURNAL TEMP DROP INTO
THE 40S OVER THE INTERIOR. WL ADD PATCHY FOG OVER THE COOLER
INTERIOR LOCATIONS FOR THE OVERNGT TIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 AM EDT WED AUG 6 2014
THURSDAY THROUGH SATURDAY...BROAD SURFACE RIDGING ALONG WITH UPPER
LEVEL 500MB RIDGING WILL BE IN PLACE ACROSS MUCH OF THE UPPER GREAT
LAKES REGION THROUGH THIS TIME FRAME. DRY WEATHER WILL BE THE RULE
UNDER THE RIDGE AS MOISTURE ADVECTION WILL BE LIMITED WITH VERY LOW
DEEP LAYER 1000-500MB RH VALUES. THE SURFACE HIGH WILL REMAIN
DIRECTLY OVERHEAD THROUGH FRIDAY BEFORE SLOWLY SHIFTING TO THE EAST
DURING THE DAY SATURDAY. THIS WILL KEEP LIGHT WINDS IN THE FORECAST
WITH THE STRONGEST GUSTS ASSOCIATED WITH LAKE BREEZE DEVELOPMENT
DURING THE AFTERNOON HOURS. AS PREVIOUS SHIFT MENTIONED...MOST AREAS
OF THE CWA HAVE SEEN LITTLE TO NO PRECIPITATION OVER THE PAST COUPLE
WEEKS WHICH MEANS SOIL AND VEGETATION ARE BEGINNING TO GET FAIRLY
DRY. DECENT MIXING CONDITIONS ARE EXPECTED TO OCCUR EACH AFTERNOON
THROUGH THIS TIME PERIOD...WHICH WILL LEAD TO INCREASED FIRE
DANGER...FORTUNATELY...WINDS WILL BE GENERALLY LIGHT AS PREVIOUSLY
MENTIONED. HAVE CONTINUED THE TREND OF LOWERING AFTERNOON DEWPOINTS
AS SOME OF THE DRIER AIR ALOFT MIXES DOWN TO THE SURFACE WITH
AFTERNOON HEATING. TEMPERATURES WILL BE CONTINUE TO WARM THROUGH
THIS PERIOD WITH 850MB TEMPS WARMING FROM 12C THURSDAY AFTERNOON TO
AROUND 14C BY SATURDAY AFTERNOON AS THE HIGH TREKS SLOWLY EASTWARD.
SATURDAY NIGHT THROUGH THE REMAINING EXTENDED...THE NEXT UPPER LEVEL
TROUGH AND DEVELOPING SURFACE LOW ARE PROGGED TO BE NEAR THE
SASKATCHEWAN/MANITOBA BORDER SATURDAY NIGHT WITH A COLD FRONT
STRETCHING SOUTHWESTWARD ACROSS THE DAKOTAS AS SHOWN BY ANALYZING
850 THETA E ALONG WITH SURFACE WINDS. THIS WILL BE THE MAIN FOCUS
FOR SHOWER AND THUNDERSTORM ACTIVITY. THE LOW WILL SHIFT EASTWARD TO
NORTHERN QUEBEC BY MONDAY AFTERNOON AS THE FRONT DRAPES ACROSS THE
UPPER GREAT LAKES. AT THIS POINT HAVE KEPT CHANCE POPS IN THE
FORECAST PEGGED MAINLY TO THE FRONT...DID NOT INCREASE TO LIKELY
POPS DUE TO CONTINUED TIMING ISSUES. RIGHT NOW THE BEST CHANCE OF
SHOWER AND THUNDERSTORM ACTIVITY WOULD BE DURING THE LATE SUNDAY
NIGHT THROUGH MONDAY TIME FRAME...WHICH WILL ALSO BE AROUND THE SAME
TIME THAT THE UPPER LEVEL 500MB TROUGH AXIS SWINGS ACROSS THE AREA.
THE FRONT IS PROGGED TO BE EAST OF THE AREA BY
TUESDAY...HOWEVER...WITH UPPER LEVEL TROUGHING AND LINGERING
MOISTURE NEARBY...WOULD EXPECT SHOWERS TO LINGER THROUGH THE DAY
TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 724 AM EDT WED AUG 6 2014
LINGERING FOG AT IWD WL BURN OFF QUICKLY SOON AFTER 12Z WITH DAYTIME
HEATING/MIXING. OTRW...EXPECT VFR CONDITIONS THRU THIS EVNG AT ALL 3
TAF SITES AS DRY HI PRES BUILDS INTO THE UPR LKS. SOME RADIATION FOG
MAY FORM LATE TNGT AT MAINLY IWD AND SAW WITH LGT WINDS UNDER MOCLR
SKIES. NOT OUT OF THE QUESTION THERE COULD BE PERIODS OF IFR VSBYS AT
THESE LOCATIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 AM EDT WED AUG 6 2014
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN INTO THE UPCOMING
WEEKEND...LEADING TO LIGHT WINDS BELOW 15 KTS THRU SAT AND NEAR CALM
WAVES. S WINDS MAY INCREASE UP TO 20 KTS ON SUN AS THE PRES GRADIENT
TIGHTENS OVER THE AREA BETWEEN THE HI PRES SHIFTING TO THE E AND AN
APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1005 AM CDT WED AUG 6 2014
.UPDATE...
ISSUED AT 1005 AM CDT WED AUG 6 2014
A FEW MINOR UPDATES TO THE SHORT TERM FORECAST...MAINLY TO ACCOUNT
FOR SLIGHTLY COOLER TEMPERATURES ACROSS OUR NORTH AND GREATER
COVERAGE OF OVC SKIES. THE UPDATES WERE TRENDED TOWARD THE LATEST
RAP AND HRRR GUIDANCE WHICH CONTINUES TO INDICATE THE PRESENCE OF
DEEP MOISTURE OVER MUCH OF THE FORECAST AREA. THE GOING FORECAST
WILL KEEP OVC SKIES ACROSS OUR NORTHERN AND CENTRAL ZONES THROUGH
MUCH OF THE DAY...SOMEWHAT MITIGATING THE EFFECTS SOLAR INSOLATION
ON THE LOWER TROPOSPHERE/EARTH SFC. OTHERWISE PRECIPITATION
FORECAST REMAINS SOMEWHAT NEBULOUS GOING INTO THE AFTERNOON
HOURS...MODELS ARE SUGGESTING QUASI- ZONAL FLOW ALOFT WILL
DIRECT ANOTHER WEAK DISTURBANCE ACROSS THE REGION...WHICH MAY SERVE AS A
FORCING MECHANISM FOR ADDITIONAL STORM DEVELOPMENT. IF STORMS ARE
REALIZED ONCE AGAIN THIS AFTERNOON...PWATS ACROSS NORTH CENTRAL
NEBRASKA AND MUCH OF THE SANDHILLS ARE DRYING SLIGHTLY...BUT STILL
ARE EXPECTED TO REMAIN TWO SD ABOVE THE MEAN...AND GIVEN
IMPRESSIVE WARM CLOUD DEPTHS OF GREATER THAN 11-12K FEET...HEAVY
RAINFALL IS POSSIBLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED AUG 6 2014
TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS IN THE MODELS HAS
VANISHED LEAVING FOR SOMEWHAT NEBULOUS DYNAMICAL FORCING TODAY
AND TONIGHT. THIS IS OCCURRING AS A RESULT OF HEIGHT RISES
ASSOCIATED WITH A DEPARTING UPPER LOW ACROSS THE CANADIAN
MARITIMES. THERE ARE ALSO INDICATIONS OF DRYING IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE ALSO. PRECIPITABLE WATER FALLS
BELOW 1.5 INCHES IN MANY AREAS.
WATER VAPOR SHOWS ANOTHER DISTURBANCE ACROSS NORTHWESTERN
COLORADO THIS MORNING AND A SECOND WEAKER DISTURBANCE ACROSS
NORTH CENTRAL COLORADO AND SOUTHEASTERN WYOMING. BOTH COULD SERVE
AS FORCING MECHANISMS FOR TSTM DEVELOPMENT. THE NAM AND OTHER
MODELS SHOW POCKETS OF K INDICES AROUND 40C THIS AFTN...MAINLY
ACROSS WESTERN NEBRASKA. THIS MOISTURE IS POOLING BEHIND THE SFC
LOW PRESSURE SYSTEM ACROSS CNTL NEB. GIVEN THE PROXIMITY OF THESE
DISTURBANCES IT WOULD APPEAR THE BETTER CHANCES OF RAIN WOULD
OCCUR FROM NOON THROUGH EARLY EVENING.
THUS THE MODELS SHOW DISORGANIZED AREAS OF SHOWERS AND
THUNDERSTORMS TODAY WHICH BECOME ISOLATED TONIGHT. THIS IS LIKELY
THE RESULT OF THE LACK OF FOCUS IN THE LOWER LEVELS OF THE
ATMOSPHERE. THE FORECAST CALLS OF ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY THIS AFTERNOON WHICH BECOMES
ISOLATED TONIGHT. MODEL BLENDED QPF AND POPS FEATURE THE BEST
CHANCES ACROSS THE NCNTL ZONES EAST OF VALENTINE INCLUDING CUSTER
COUNTY. THIS FORECAST USES 50 PERCENT OF THE
ECM...GFS...NAM...GEM AND SREF AND 50 PERCENT OF THE RAP MODEL
HAS PERFORMED FAIRLY WELL.
COOLER AIR WILL FILLS IN BEHIND THE SFC LOW AS IT MIGRATES SOUTH
AND EAST INTO KANSAS AND SOUTHEAST NEBRASKA. THIS SHOULD KEEP
HIGHS IN THE UPPER 70S TO UPPER 80S TODAY WITH HIGH HUMIDITY ONCE
AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED AUG 6 2014
LITTLE CHANGE FOR THURSDAY AS UPPER RIDGE LOCATES ACROSS THE
SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. RIDGE RIDERS TO CROSS
THE CENTRAL ROCKIES AND ONTO THE HIGH PLAINS. MODELS IN GOOD
AGREEMENT BRINGING A DISTURBANCE ACROSS THE AREA LATE THURSDAY.
MODELS DROP PWATS EARLY...HOWEVER AN INCREASE IS EXPECTED TO
GREATER THAN 2 SD BY LATE AFTERNOON. MODELS ARE CURRENTLY
FAVORING SW NEB AND WILL RETAIN HIGHEST POPS...LIKELY...THERE.
MODELS CONTINUE TO AGREE BRINGING ADDITIONAL WAVES ACROSS THE
AREA INTO THE WEEKEND. RAIN CHANCES WILL REMAIN
POSSIBLE...HOWEVER COVERAGE STILL IN QUESTION. TEMPS ARE A LITTLE
TRICKY AS THE RIDGE CONTINUES TO FLATTEN...AND CLOUD COVER WILL
BE KEY TO AFTERNOON PEAKS. GENERALLY EXPECT HIGHS AT OR BELOW
SEASONAL NORMS...WHICH IS IN THE MID AND UPPER 80S.
AS WE GO INTO NEXT WEEK MODELS DIVERGE. THE GFS BEGINS TO REBUILD
THE RIDGE IN THE WEST...WHILE THE ECMWF KEEPS THE RIDGE
FLATTENED. THE GFS WOULD FAVOR A WARMER FORECAST COMPARED TO THE
EC...HOWEVER AS THE RIDGE BUILDS...PER GFS SOLUTION...NORTHWEST
FLOW WOULD CONTINUE TO BRING DISTURBANCES ACROSS THE AREA. THUS
WILL KEEP THE BLENDED FORECAST AS WILL STILL HAVE AT LEAST
PERIODIC LOW CHANCES FOR RAIN. LESS CERTAINTY FOR TEMPS AND WILL
KEEP BLENDED GUIDANCE AND MONITOR TO SEE HOW MODELS CHANGE OVER
THE COMING DAYS TO MAKE ADJUSTMENTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 913 AM CDT WED AUG 6 2014
KVTN TERMINAL FORECAST UPDATED AS SHORT RANGE MODELS AND THE
SOUNDING PROFILE SHOWED A 3000 FT LAYER OF DEEP MOISTURE IN PLACE.
THE CURRENT LIFR CEILINGS SHOULD LIFT THROUGH 16Z THEN CONTINUE TO
LIFT THROUGH MVFR TO VFR CEILINGS NEAR 5000 FT AROUND 21Z. THE
SEMI STATIONARY FRONT ACROSS SOUTHERN NEBRASKA THIS MORNING IS
FORECAST TO MOVE SOUTH TONIGHT WHERE THE PREVAILING FLOW WILL KEEP
LOW CEILINGS AND AREAS OF FOG IN THE FORECAST. A REPEAT TONIGHT
FOR THE KVTN TERMINAL WITH THE LOW STRATUS (MVFR/IFR CONDITIONS) SHOULD
EXTEND FURTHER SOUTHWEST TO INCLUDE THE KLBF TERMINAL THURSDAY
MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JACOBS
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...KECK
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
937 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED AUG 6 2014
TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS IN THE MODELS HAS
VANISHED LEAVING FOR SOMEWHAT NEBULOUS DYNAMICAL FORCING TODAY
AND TONIGHT. THIS IS OCCURRING AS A RESULT OF HEIGHT RISES
ASSOCIATED WITH A DEPARTING UPPER LOW ACROSS THE CANADIAN
MARITIMES. THERE ARE ALSO INDICATIONS OF DRYING IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE ALSO. PRECIPITABLE WATER FALLS
BELOW 1.5 INCHES IN MANY AREAS.
WATER VAPOR SHOWS ANOTHER DISTURBANCE ACROSS NORTHWESTERN
COLORADO THIS MORNING AND A SECOND WEAKER DISTURBANCE ACROSS
NORTH CENTRAL COLORADO AND SOUTHEASTERN WYOMING. BOTH COULD SERVE
AS FORCING MECHANISMS FOR TSTM DEVELOPMENT. THE NAM AND OTHER
MODELS SHOW POCKETS OF K INDICES AROUND 40C THIS AFTN...MAINLY
ACROSS WESTERN NEBRASKA. THIS MOISTURE IS POOLING BEHIND THE SFC
LOW PRESSURE SYSTEM ACROSS CNTL NEB. GIVEN THE PROXIMITY OF THESE
DISTURBANCES IT WOULD APPEAR THE BETTER CHANCES OF RAIN WOULD
OCCUR FROM NOON THROUGH EARLY EVENING.
THUS THE MODELS SHOW DISORGANIZED AREAS OF SHOWERS AND
THUNDERSTORMS TODAY WHICH BECOME ISOLATED TONIGHT. THIS IS LIKELY
THE RESULT OF THE LACK OF FOCUS IN THE LOWER LEVELS OF THE
ATMOSPHERE. THE FORECAST CALLS OF ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY THIS AFTERNOON WHICH BECOMES
ISOLATED TONIGHT. MODEL BLENDED QPF AND POPS FEATURE THE BEST
CHANCES ACROSS THE NCNTL ZONES EAST OF VALENTINE INCLUDING CUSTER
COUNTY. THIS FORECAST USES 50 PERCENT OF THE
ECM...GFS...NAM...GEM AND SREF AND 50 PERCENT OF THE RAP MODEL
HAS PERFORMED FAIRLY WELL.
COOLER AIR WILL FILLS IN BEHIND THE SFC LOW AS IT MIGRATES SOUTH
AND EAST INTO KANSAS AND SOUTHEAST NEBRASKA. THIS SHOULD KEEP
HIGHS IN THE UPPER 70S TO UPPER 80S TODAY WITH HIGH HUMIDITY ONCE
AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED AUG 6 2014
LITTLE CHANGE FOR THURSDAY AS UPPER RIDGE LOCATES ACROSS THE
SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. RIDGE RIDERS TO CROSS
THE CENTRAL ROCKIES AND ONTO THE HIGH PLAINS. MODELS IN GOOD
AGREEMENT BRINGING A DISTURBANCE ACROSS THE AREA LATE THURSDAY.
MODELS DROP PWATS EARLY...HOWEVER AN INCREASE IS EXPECTED TO
GREATER THAN 2 SD BY LATE AFTERNOON. MODELS ARE CURRENTLY
FAVORING SW NEB AND WILL RETAIN HIGHEST POPS...LIKELY...THERE.
MODELS CONTINUE TO AGREE BRINGING ADDITIONAL WAVES ACROSS THE
AREA INTO THE WEEKEND. RAIN CHANCES WILL REMAIN
POSSIBLE...HOWEVER COVERAGE STILL IN QUESTION. TEMPS ARE A LITTLE
TRICKY AS THE RIDGE CONTINUES TO FLATTEN...AND CLOUD COVER WILL
BE KEY TO AFTERNOON PEAKS. GENERALLY EXPECT HIGHS AT OR BELOW
SEASONAL NORMS...WHICH IS IN THE MID AND UPPER 80S.
AS WE GO INTO NEXT WEEK MODELS DIVERGE. THE GFS BEGINS TO REBUILD
THE RIDGE IN THE WEST...WHILE THE ECMWF KEEPS THE RIDGE
FLATTENED. THE GFS WOULD FAVOR A WARMER FORECAST COMPARED TO THE
EC...HOWEVER AS THE RIDGE BUILDS...PER GFS SOLUTION...NORTHWEST
FLOW WOULD CONTINUE TO BRING DISTURBANCES ACROSS THE AREA. THUS
WILL KEEP THE BLENDED FORECAST AS WILL STILL HAVE AT LEAST
PERIODIC LOW CHANCES FOR RAIN. LESS CERTAINTY FOR TEMPS AND WILL
KEEP BLENDED GUIDANCE AND MONITOR TO SEE HOW MODELS CHANGE OVER
THE COMING DAYS TO MAKE ADJUSTMENTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 913 AM CDT WED AUG 6 2014
KVTN TERMINAL FORECAST UPDATED AS SHORT RANGE MODELS AND THE
SOUNDING PROFILE SHOWED A 3000 FT LAYER OF DEEP MOISTURE IN PLACE.
THE CURRENT LIFR CEILINGS SHOULD LIFT THROUGH 16Z THEN CONTINUE TO
LIFT THROUGH MVFR TO VFR CEILINGS NEAR 5000 FT AROUND 21Z. THE
SEMI STATIONARY FRONT ACROSS SOUTHERN NEBRASKA THIS MORNING IS
FORECAST TO MOVE SOUTH TONIGHT WHERE THE PREVAILING FLOW WILL KEEP
LOW CEILINGS AND AREAS OF FOG IN THE FORECAST. A REPEAT TONIGHT
FOR THE KVTN TERMINAL WITH THE LOW STRATUS (MVFR/IFR CONDITIONS) SHOULD
EXTEND FURTHER SOUTHWEST TO INCLUDE THE KLBF TERMINAL THURSDAY
MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...KECK
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
620 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED AUG 6 2014
TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS IN THE MODELS HAS
VANISHED LEAVING FOR SOMEWHAT NEBULOUS DYNAMICAL FORCING TODAY
AND TONIGHT. THIS IS OCCURRING AS A RESULT OF HEIGHT RISES
ASSOCIATED WITH A DEPARTING UPPER LOW ACROSS THE CANADIAN
MARITIMES. THERE ARE ALSO INDICATIONS OF DRYING IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE ALSO. PRECIPITABLE WATER FALLS
BELOW 1.5 INCHES IN MANY AREAS.
WATER VAPOR SHOWS ANOTHER DISTURBANCE ACROSS NORTHWESTERN
COLORADO THIS MORNING AND A SECOND WEAKER DISTURBANCE ACROSS
NORTH CENTRAL COLORADO AND SOUTHEASTERN WYOMING. BOTH COULD SERVE
AS FORCING MECHANISMS FOR TSTM DEVELOPMENT. THE NAM AND OTHER
MODELS SHOW POCKETS OF K INDICES AROUND 40C THIS AFTN...MAINLY
ACROSS WESTERN NEBRASKA. THIS MOISTURE IS POOLING BEHIND THE SFC
LOW PRESSURE SYSTEM ACROSS CNTL NEB. GIVEN THE PROXIMITY OF THESE
DISTURBANCES IT WOULD APPEAR THE BETTER CHANCES OF RAIN WOULD
OCCUR FROM NOON THROUGH EARLY EVENING.
THUS THE MODELS SHOW DISORGANIZED AREAS OF SHOWERS AND
THUNDERSTORMS TODAY WHICH BECOME ISOLATED TONIGHT. THIS IS LIKELY
THE RESULT OF THE LACK OF FOCUS IN THE LOWER LEVELS OF THE
ATMOSPHERE. THE FORECAST CALLS OF ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY THIS AFTERNOON WHICH BECOMES
ISOLATED TONIGHT. MODEL BLENDED QPF AND POPS FEATURE THE BEST
CHANCES ACROSS THE NCNTL ZONES EAST OF VALENTINE INCLUDING CUSTER
COUNTY. THIS FORECAST USES 50 PERCENT OF THE
ECM...GFS...NAM...GEM AND SREF AND 50 PERCENT OF THE RAP MODEL
HAS PERFORMED FAIRLY WELL.
COOLER AIR WILL FILLS IN BEHIND THE SFC LOW AS IT MIGRATES SOUTH
AND EAST INTO KANSAS AND SOUTHEAST NEBRASKA. THIS SHOULD KEEP
HIGHS IN THE UPPER 70S TO UPPER 80S TODAY WITH HIGH HUMIDITY ONCE
AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED AUG 6 2014
LITTLE CHANGE FOR THURSDAY AS UPPER RIDGE LOCATES ACROSS THE
SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. RIDGE RIDERS TO CROSS
THE CENTRAL ROCKIES AND ONTO THE HIGH PLAINS. MODELS IN GOOD
AGREEMENT BRINGING A DISTURBANCE ACROSS THE AREA LATE THURSDAY.
MODELS DROP PWATS EARLY...HOWEVER AN INCREASE IS EXPECTED TO
GREATER THAN 2 SD BY LATE AFTERNOON. MODELS ARE CURRENTLY
FAVORING SW NEB AND WILL RETAIN HIGHEST POPS...LIKELY...THERE.
MODELS CONTINUE TO AGREE BRINGING ADDITIONAL WAVES ACROSS THE
AREA INTO THE WEEKEND. RAIN CHANCES WILL REMAIN
POSSIBLE...HOWEVER COVERAGE STILL IN QUESTION. TEMPS ARE A LITTLE
TRICKY AS THE RIDGE CONTINUES TO FLATTEN...AND CLOUD COVER WILL
BE KEY TO AFTERNOON PEAKS. GENERALLY EXPECT HIGHS AT OR BELOW
SEASONAL NORMS...WHICH IS IN THE MID AND UPPER 80S.
AS WE GO INTO NEXT WEEK MODELS DIVERGE. THE GFS BEGINS TO REBUILD
THE RIDGE IN THE WEST...WHILE THE ECMWF KEEPS THE RIDGE
FLATTENED. THE GFS WOULD FAVOR A WARMER FORECAST COMPARED TO THE
EC...HOWEVER AS THE RIDGE BUILDS...PER GFS SOLUTION...NORTHWEST
FLOW WOULD CONTINUE TO BRING DISTURBANCES ACROSS THE AREA. THUS
WILL KEEP THE BLENDED FORECAST AS WILL STILL HAVE AT LEAST
PERIODIC LOW CHANCES FOR RAIN. LESS CERTAINTY FOR TEMPS AND WILL
KEEP BLENDED GUIDANCE AND MONITOR TO SEE HOW MODELS CHANGE OVER
THE COMING DAYS TO MAKE ADJUSTMENTS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 616 AM CDT WED AUG 6 2014
SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO CONTINUE TODAY
WITH COVERAGE BECOMING ISOLATED AROUND 06Z TONIGHT. THE LIFR/IFR
CIGS ACROSS NCNTL NEB THIS MORNING ARE EXPECTED TO LIFT TO VFR
AND/OR SCATTER OUT 15Z-18Z THIS MORNING. THE LOW CIGS RETURN
03Z-06Z TONIGHT ACROSS NWRN/NCNTL NEB AND PERHAPS DEVELOP AS FAR
SOUTH AS I-80 BY 10Z THURSDAY MORNING.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
615 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 214 AM CDT WED AUG 6 2014
TIMING AND EXTENT OF NUMEROUS PRECIP EVENTS REMAINS THE MAIN
CONCERN AND PROBLEM DURING THE PERIOD.
SCATTERED CONVECTION EXTENDED FROM NORTH CENTRAL NEBRASKA INTO
SOUTH CENTRAL IOWA AT 07Z GENERALLY ALONG AXIS OF 850-700MB
MOISTURE ADVECTION AND NORTH OF WEAK SURFACE BOUNDARY OVER
SOUTHEAST NEBRASKA. SHORT RANGE RAP MAINTAINS THE PRIMARY AXIS
NEAR NORTHERN BORDER OF THE FORECAST AREA THROUGH THE MORNING WITH
SOME DRIFT TO THE NORTH THIS AFTERNOON AS UPPER WAVE TRACKS
SOUTHEAST ACROSS EASTERN NEBRASKA. CURRENT POPS BASED ON THIS IDEA
WITH LIKELY ACROSS NORTHERN AREAS AND CHANCE ELSEWHERE.
MODELS DROP WESTERN NEBRASKA SURFACE WAVE INTO WESTERN KANSAS BY
EVENING WITH ASSOCIATED BOUNDARY ALSO MOVING SOUTH AND EAST
TONIGHT. PRECIP LOOKS TO BECOME MORE NORTH SOUTH ORIENTED TONIGHT
ACROSS THE AREA IN LINE WITH LOW LEVEL TEMPERATURE AND MOISTURE
ADVECTION WITH A GENERAL DRIFT TO THE EAST. POPS DECREASE WEST TO
EAST LATE TONIGHT INTO THURSDAY AS THE UPPER WAVE AND BETTER
MOISTURE MOVE INTO THE MISSISSIPPI VALLEY.
ON THURSDAY NIGHT MODELS SUGGEST DEVELOPMENT OF CONVECTIVE SYSTEM
OVER THE HIGH PLAINS THURSDAY EVENING AS ANOTHER UPPER WAVE
APPROACHES THAT THEN MOVES EAST THURSDAY NIGHT AND FRIDAY. AT
THIS TIME IT APPEARS MOST OF THE PRECIP WILL REMAIN WEST OF THE
AREA TONIGHT WITH LOW POPS FOR WESTERN PARTS OF THE AREA LATE
TONIGHT INTO FRIDAY.
TEMPERATURE FORECAST A BLEND OF GUIDANCE THROUGH THE PERIOD.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 214 AM CDT WED AUG 6 2014
GENERAL PATTERN CONTINUES INTO THE FIRST PART OF THE EXTENDED
PERIOD WITH POPS FOR MUCH OF THE AREA FRIDAY NIGHT INTO SUNDAY
NIGHT. MODELS REBUILD THE UPPER RIDGE EARLY NEXT WEEK ALTHOUGH
EURO NOT AS QUICKLY AS THE GFS. SOME UNCERTAINTY DURING THIS TIME
REGARDING POPS AS EURO KEEPS UPPER WAVES ACROSS THE AREA. KEEP
FORECAST DRY FOR NOW INSTEAD OF CARRYING SLIGHT POPS.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 615 AM CDT WED AUG 6 2014
RATHER COMPLEX FORECAST OVER THE NEXT 24 HOURS WITH SEVERAL ROUNDS
OF SHOWERS AND THUNDERSTORMS POSSIBLE...ALONG WITH IFR/MVFR
CONDITIONS AT KOFK/KOMA. STRONGER STORMS COULD OCCUR LATER IN THE
MORNING/AFTERNOON/EVENING AS INSTABILITY INCREASES. WINDS
INITIALLY SOUTHEASTERLY...GENERALLY LESS THAN 12 KNOTS EXCEPT NEAR
STORMS...BUT BACK WITH TIME AND EVENTUALLY BECOME NORTHEAST AND
EVEN NORTH TONIGHT AS SURFACE LOW PRESSURE MOVES THROUGH SOUTHEAST
NEBRASKA. IFR CONDITIONS LIKELY DEVELOP LATE IN THE PERIOD BY
05-07Z...AND COULD EVEN BECOME LIFR AT KOFK BY 07Z AND BEYOND.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...FOBERT
LONG TERM...FOBERT
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS TULSA OK
835 AM CDT WED AUG 6 2014
.DISCUSSION...
A BAND OF HIGH BASED SHOWERS WAS OBSERVED ON RADAR ACROSS CENTRAL
OK THIS MORNING. LOOKING AT THE 12Z OUN SOUNDING...THE 500MB-300MB
LEVEL HAS MOISTENED UP QUITE A BIT COMPARED TO THE 00Z
SOUNDING...BUT LAPSE RATES ARE BASICALLY MOIST ADIABATIC IN THIS
LAYER AND THUS NO LIGHTNING HAS BEEN OBSERVED. THE HRRR AND LOCAL
WRF DATA ALL SUGGEST GRADUAL WEAKENING OF THIS BAND AS IT HEADS
EAST THRU THE DAY...WHICH MAKES SENSE GIVEN THE NORMAL DIURNAL
TREND FOR HIGH BASED ACTIVITY. HOWEVER THERE IS AT LEAST A SLIGHT
CHANCE OF THIS MAKING IT INTO OUR FORECAST AREA MAINLY WEST OF
HIGHWAY 75 LATE THIS MORNING INTO THE AFTERNOON BEFORE IT DOES
SO...THUS THE FORECAST HAS BEEN TWEAKED. THE LATEST DATA IS ALSO
NOT TOO EXCITED ABOUT AFTERNOON SURFACE BASED STORM
CHANCES...SUGGESTING THE BETTER CHANCES WILL BE NORTH UP IN
KANSAS WHERE A FOCUSING BOUNDARY LIES...IN THIS CASE AN EAST-WEST
ORIENTED SURFACE TROUGH. THE ECMWF DOES HAVE SOME DVLPMT NEAR THE
KS BORDER HOWEVER. THE GOING LOW POPS NEAR THE KS BORDER WILL BE
LEFT ALONE GIVEN THE UNCERTAINTY. UPDATED TEXT PRODUCTS HAVE BEEN
SENT.
LACY
&&
.PREV DISCUSSION... /ISSUED 651 AM CDT WED AUG 6 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR THROUGH 00Z. AFTER 00Z THUNDERSTORMS NEAR KS/OK
BORDER WILL SLIDE/DEVELOP SOUTHEAST INTO NORTHEAST OK
AND NORTHWEST AR. TAF SITES KBVO KTUL KRVS KXNA KFYV WITH
PROB30 RISK TSRA DURING EVENING / LATE NIGHT HOURS.
PREV DISCUSSION... /ISSUED 329 AM CDT WED AUG 6 2014/
DISCUSSION...
UNSETTLED WEATHER FOR THE NEXT SEVERAL DAYS. APPEARS AN H5 SHORT
WAVE WILL MOVE THROUGH THE RIDGE OVER THE ROCKIES AND SWING
THROUGH OK/KS/AR TODAY AND TONIGHT. THIS WILL TRY TO DRAG A
WEAK FRONT INTO SOUTHEAST KS. THE FRONT AND UPPER SUPPORT WILL
PROVIDE A CHANCE OF THUNDERSTORMS ACROSS MAINLY THE NORTHERN
PORTION OF THE FORECAST AREA. OCCASIONAL H5 SHORT WAVES AND
WESTERLY TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE THROUGH THE
FORECAST CYCLE AND PROVIDE SOME CHANCES OF THUNDERSTORMS ALMOST
EACH DAY AND NIGHT.
BEST CHANCE OF RAIN APPEARS TO BE LATE TONIGHT INTO THURSDAY
MORNING...AND MAINLY OVER FAR NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS. APPEARS CONVECTION LIKELY TO DEVELOP OVER EASTERN KS NEAR
THE NEARLY STATIONARY FRONT. THIS PRECIPITATION SHOULD MOVE TO THE
SOUTHEAST AND PROVIDE A REASONABLY GOOD CHANCE FOR
RAIN...ESPECIALLY IN NORTHWEST ARKANSAS.
GENERALLY WARM AND HUMID CONDITIONS EXPECTED THROUGH THE NEXT 7
DAYS. SOME MODERATION IN TEMPS MAY BE POSSIBLE ABOUT TUESDAY AS
NORTHWEST FLOW COULD PUSH ANOTHER FRONT INTO THE AREA...BUT MODEL
BLENDS KEEP TEMPERATURES WARM FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 94 76 95 75 / 10 30 30 20
FSM 94 73 93 73 / 10 10 30 20
MLC 93 74 94 74 / 10 10 20 10
BVO 94 71 94 69 / 20 40 30 20
FYV 91 71 90 69 / 10 20 40 20
BYV 92 71 90 71 / 10 20 40 30
MKO 94 73 94 72 / 10 20 20 20
MIO 93 73 91 71 / 20 50 40 30
F10 93 72 93 72 / 10 20 20 10
HHW 92 72 93 73 / 10 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1047 AM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WILL SETTLE THROUGH THE AREA TODAY. COOLER AND LESS
HUMID CONDITIONS WILL OVERSPREAD THE STATE TONIGHT...AND LAST INTO
THIS COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
THE SURFACE BOUNDARY IS PRETTY DIFFUSE BUT SEEMS TO BE JUST SOUTH
OF STATE COLLEGE SEPARATING DEWPOINTS IN THE LOWER TO MID 60S
FROM READINGS IN THE MID-UPPER 50S. SCATTERED SHOWERS CONTINUE TO
WORK ACROSS THE SOUTHERN HALF OF THE FCST AREA WITHIN THE WEAK
CONVERGENCE ZONE. THE HRRR SHOWS THESE SHOWERS CONTINUING OFF TO
THE ESE...BASICALLY CLEARING THE SOUTHERN ZONES BY EARLY AFTERNOON.
THE BIGGEST CHALLENGE FOR THE REMAINDER OF THE DAY WILL BE HOW
MUCH CONVECTION MANAGES TO REFIRE BACK OVER THE REMAINDER OF THE
FORECAST AREA AS A NEW SHORTWAVE CURRENTLY DIVING THROUGH
WISCONSIN MOVES INTO THE REGION. MODELS SHOW A STRONG JET
ENTRANCE REGION NOSING INTO OHIO...WITH PA IN THE FAVORABLE LEFT
EXIT REGION INTO THE AFTERNOON HOURS. MESO ANAL SHOWS CAPES
REBOUNDING OVER OHIO INTO WESTERN PA SO WE HAVE FAVORABLE LARGE
SCALE FORCING AND SOME DEVELOPING INSTABILITY. HOWEVER DRIER AIR
IS MOVING IN AS EVIDENCED BY PWATS WHICH ARE DECREASING...SO IT
WILL BE A RACE BETWEEN WHAT MOISTURE IS LEFT AS A FAIRLY STRONG
SHORTWAVE MOVES INTO THE AREA LATER TODAY.
ISOLATED TO SCT SHOWER/TSTM ACTIVITY WILL END BETWEEN 19-22Z
ACROSS THE NORTH...AND IN THE EARLY EVENING HOURS OVER MUCH OF
THE SRN TIER ZONES.
HIGH TEMPS THIS AFTERNOON WILL BE IN THE LOWER TO MID 70S ACROSS
THE NRN MTNS...AND UPPER 70S TO LOWER 80S FURTHER TO SOUTHEAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
A REFRESHING...LOW PWAT AIRMASS WILL PUSH SOUTHEAST INTO THE STATE
LATER TONIGHT AND THURSDAY.
WEAK GRADIENT LATER TONIGHT AND MOIST GROUND FROM WEDNESDAY/S
RAIN WILL LEAD TO AREAS OF FOG /WHICH WILL LIKELY BE LOCALLY
DENSE/.
LG SCALE FORCING ON THE SOUTHWEST FRINGE OF A SLOWLY PROGRESSING
MID-UPPER LVL TROUGH MOVG EWD ACRS INTERIOR NEW ENGLAND/NORTHEAST
STATES...ALONG WITH ACCOMPANYING PLUME OF RELATIVELY STEEP MID-LVL
LAPSE RATES NEAR 6 C/KM ASSOC WITH -15C AT 500MB AND ANOMALOUS H7
TEMPS MAY INITIATE A FEW INSTABILITY SHOWERS OVER NRN-NERN SXNS ON
THU. GRIDDED SKY COVER MAY NEED TO BE ADJUSTED UPWARD AS THE SET-
UP APPEARS FAVORABLE FOR AT LEAST A BKN CU FIELD TO DVLP BY AFTN.
OTHERWISE..EXPECT A RATHER PLEASANT DAY WITH COMFORTABLE HUMIDITY
AND 5-10KT NNW WIND.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /14Z WEDNESDAY THROUGH SUNDAY/...
AREAS OF MVFR WILL CONTINUE TO LIFT WITH DAYTIME HEATING LEAVING
ALL TERMINALS VFR BY THE LATE MORNING-MID DAY TIMEFRAME.
ADDITIONAL CONVECTIVE ACTIVITY IS EXPECTED TO DEVELOP THIS
AFTERNOON WITH THE APPROACH OF A POTENT UPPER AIR DISTURBANCE.
AIRPORTS WILL REMAIN VFR EXCEPT IF HIT BY THE SCATTERED SHOWERS
AND THUNDERSTORMS WHICH WILL CAUSE BRIEF REDUCTIONS.
AS EVENING APPROACHES..SHOWERS AND STORMS WILL BEGIN TO FADE.
OTHER THAN SOME PATCHY FOG OVERNIGHT...EXPECT VFR CONDITIONS AS
DRIER BEGINS TO MOVE INTO THE REGION.
TOMORROW WILL BEGIN A SEVERAL DAY PERIOD OF NON-EVENTFUL WEATHER
AND PRIMARILY VFR CONDITIONS.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LA CORTE/LAMBERT
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
658 AM CDT WED AUG 6 2014
.AVIATION...
CONCERNS...ISOLATED AFTERNOON/EARLY EVENING STORMS POSSIBLE AT THE
METROPLEX TAF SITES.
ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY
EVENING ACROSS NORTH TEXAS AS A WEAK UPPER LEVEL DISTURBANCE
MOVES ACROSS OKLAHOMA. OTHERWISE...THE UPPER LEVEL RIDGE WILL
CONTINUE TO DOMINATE THE WEATHER ACROSS NORTH AND CENTRAL TEXAS.
ALTHOUGH THUNDERSTORM CHANCES AT THE INDIVIDUAL TAF SITES ARE TOO
LOW TO MENTION IN THE TAFS...BE AWARE THAT THE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE WIND GUSTS OVER 35 KNOTS AND CLOUD TO GROUND
LIGHTNING. SOUTH WINDS AT 10 KNOTS OR LESS WILL PREVAIL.
58
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT WED AUG 6 2014/
HAVING A BIT OF A CONUNDRUM IN REGARDS TO STORMS. ATMOSPHERE WILL
BE POTENTIALLY UNSTABLE IN THE AFTERNOON...BUT THERE REALLY IS NO
GREAT FORCING. TODAY...4KM WRF IS GOING FOR BROKE WITH A LINE OF
STORMS ACROSS OKLAHOMA STRETCHING SOUTH INTO NORTHWEST NORTH
TX...BUT IT IS WAY MORE AGGRESSIVE THAN OTHER MODELS. WRF ARW
DEVELOPS ISOLATED CONVECTION IN THE METROPLEX...BUT AGAIN NOT
SUPPORTED BY OTHER MODELS. FORECAST SOUNDINGS SHOW MOISTURE IS
MORE SHALLOW TODAY THAN YESTERDAY. THE RAP FORECASTS AN UNSTABLE
ATMOSPHERE WITH 450 J/KG CAPE...BUT DOES NOT DEVELOP STORMS.
FOR THURSDAY...A SHORT WAVE MOVES ACROSS THE CENTRAL PLAINS...BUT
THE NAM DEVELOPS SOME CONVECTION IN WESTERN ZONES AND DRIVES IT
SOUTH DURING THE AFTERNOON. THE TTU WRF PLACES A SMALL CONNECTIVE
CLUSTER IN YOUNG/STEPHENS COUNTIES...BUT AGAIN ACTIVITY IS NOT
SUPPORTED BY OTHER MODELS.
I HAVE OPTED TO KEEP ISOLATED STORMS IN THE SOUTHEAST AND ADDED
ISOLATED STORMS IN THE NORTHWEST TODAY. WILL NOT ADD ANY PRECIP
THROUGH THE REST OF THE FORECAST BUT MAY HAVE TO BUMP SOME AREAS
UP TO LOW CHANCES TONIGHT IF THURSDAY LOOKS ANY WETTER.
TEMPERATURES ARE GOING TO CLIMB SLOWLY AS THE RIDGE BUILDS
IN...AND HAVE NUMEROUS AREAS WITH TRIPLE DIGITS BY SUNDAY. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 78 98 78 99 / 10 10 10 10 10
WACO, TX 97 76 98 75 98 / 10 10 10 10 5
PARIS, TX 92 73 94 74 95 / 10 10 10 10 10
DENTON, TX 95 76 95 77 97 / 10 10 10 10 10
MCKINNEY, TX 95 75 96 76 97 / 10 10 10 10 10
DALLAS, TX 97 78 98 78 99 / 10 10 10 10 10
TERRELL, TX 97 75 97 75 98 / 10 10 10 10 10
CORSICANA, TX 96 74 95 75 97 / 10 10 10 10 10
TEMPLE, TX 95 74 96 74 97 / 10 10 10 10 5
MINERAL WELLS, TX 98 75 99 75 98 / 10 10 10 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
58/84
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
612 AM CDT WED AUG 6 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING THE AREA UNDER A
GENERAL TROUGH ALOFT WITH RIDGING OVER THE CENTRAL AND NORTHERN
PLAINS. GOOD PLUME OF SUBTROPICAL MOISTURE SURGING NORTHWARD ACROSS
THE PLAINS WITH A WEAK SHORTWAVE TROUGH AND MID-LEVEL FRONTOGENESIS
FUELING A BAND OF SHOWERS/THUNDERSTORMS ACROSS EASTERN ND/NEB...INTO
WESTERN AND CENTRAL IA. CLOSER IN...THE ARX FORECAST AREA WAS MOSTLY
CLEAR EAST OF THE MISSISSIPPI WITH WEAK TO CALM SURFACE WIND. THIS
WAS ALLOWING SOME FOG TO SET UP ACROSS PORTIONS OF CENTRAL WI AND IN
THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. TEMPERATURES EARLY THIS
MORNING RANGED FROM THE MIDDLE 50S TO THE LOWER 60S.
FOR TODAY...SURFACE HIGH PRESSURE WILL HOLD OVER THE GREAT LAKES
REGION AS A MID-LEVEL SHORTWAVE TROUGH BUDGES EASTWARD FROM THE
CENTRAL PLAINS INTO WESTERN IA. MODELS IN PRETTY GOOD AGREEMENT
SHOWING ASSOCIATED SHOWERS/ISOLATED THUNDER JUST NIPPING PARTS OF
NORTHEAST IA BY NOON. DURING THE AFTERNOON DRIER AIR OUTFLOW FROM
THE GREAT LAKES HIGH LOOKS TO HALT ANY FARTHER NORTHEAST PUSH OF
THIS SHOWER/ISOLATED THUNDER ACTIVITY. IN FACT...APPEARS SOME OF
THIS RAIN MAY RETREAT FARTHER SOUTHWEST AN MAYBE ENTIRELY OUT OF OUR
AREA. OTHERWISE...PLAN ON PARTLY SUNNY SKIES EAST OF THE MISSISSIPPI
RIVER WITH CLOUD COVER DOMINATING WEST OF THE RIVER. HIGHS TODAY
EXPECTED TO TOP OFF IN THE 70S.
FOR TONIGHT INTO THURSDAY...MODELS COMING IN CLOSER AGREEMENT WITH
FAIRLY VIGOROUS MID-LEVEL TROUGH DROPPING THROUGH THE DAKOTAS INTO
THE MID/UPPER MISSISSIPPI RIVER VALLEY REGION. NAM STILL SHOWING
STRONG 850-500MB FRONTOGENESIS WITH THIS WAVE MOVING ALONG AND SOUTH
OF I-90 MAINLY DURING THE DAY THURSDAY. THE GFS IS SLIGHTLY FASTER
WITH THE WAVE COMPARED TO THE NAM/ECMWF/GEM AND HAS WEAKER
FRONTOGENESIS FOCUSED MORE ACROSS IA/IL. SINCE GFS SEEMS TO BE THE
ODD MODEL OUT...RAISED POPS TO HONOR MORE THE GFS/ECMWF/GEM MORE
NORTHERN SOLUTIONS. BTW...NOT MUCH CAPE INVOLVED WITH THIS WAVE...SO
TAPERED THUNDER TO ISOLATED MENTION GIVEN FORCING SIGNAL.
WILL HAVE TO CONTINUE WATCHING THE EVOLUTION/RAIN POTENTIAL OF THIS
SYSTEM AS IT IS ALWAYS A BIT TRICKY GIVEN DRY LOWER LEVEL OUTFLOW
FROM GREAT LAKES HIGH PRESSURE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
FOR THURSDAY NIGHT INTO FRIDAY...NAM/ECMWF/GEM SHOW SOME LINGERING
DEFORMATION SHOWERS AND ISOLATED THUNDER FOCUSED MAINLY ALONG AND
SOUTH OF I-90. CARRIED LOWER-END POPS TO COVER THIS.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOK DRY AS MIDDLE LEVEL RIDGE
DRIFTS OVERHEAD.
SHOWER/THUNDERSTORM CHANCES RETURN TO THE AREA SUNDAY LASTING
THROUGH TUESDAY AS A COLD FRONT MOVES THROUGH AND COOLER CYCLONIC
FLOW ALOFT LINGERS.
TEMPERATURES FRIDAY THROUGH THE PERIOD LOOK RIGHT AROUND NORMAL
LEVELS WITH DAYTIME READINGS IN THE UPPER 70S TO THE LOWER 80S AND
IN THE UPPER 50S/LOWER 60S AT NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 612 AM CDT WED AUG 6 2014
VALLEY FOG WAS ABLE TO FORM BEFORE THE LAYER OF HIGH LEVEL CLOUDS
MOVED OVER THE AREA. DESPITE THE HIGH CLOUDS...THE FOG HAS
REMAINED AND EXPECT IT WILL BE MID MORNING BEFORE THIS SHOWS ITS
NORMAL DIURNAL DISSIPATION. ONCE THE FOG IS GONE...EXPECT THE
SURFACE HIGH OVER THE GREAT LAKES TO PROVIDE A DRY EAST FLOW THAT
WILL KEEP THE RAIN WELL WEST OF THE TAF SITES WITH JUST SOME HIGH
VFR CEILINGS. THE 06.00Z NAM WAS SUGGESTING A BAND OF MID LEVEL
FRONTOGENESIS WOULD APPROACH FROM THE SOUTHWEST OVERNIGHT BUT THE
06.06Z NAM NOW SUGGESTS THIS WILL REMAIN OVER IOWA WITH LITTLE
THREAT FOR ANY RAIN. THERE COULD STILL BE A MID LEVEL VFR CEILING
DEVELOP FROM THIS FRONTOGENESIS AND WILL SHOW THIS AT KRST WHICH
SHOULD BE CLOSER TO THE FORCING THAN KLSE. BELIEVE THERE WILL BE
ENOUGH HIGH LEVEL CLOUDS THROUGH THE NIGHT TO PRECLUDE THE
FORMATION OF ANY VALLEY FOG TONIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...04
AREA FORECAST DISCUSSION
NWS TUCSON AZ
230 PM MST WED AUG 6 2014
.SYNOPSIS...DRIER AIR WILL LIMIT THUNDERSTORMS TO MAINLY NEAR THE
NEW MEXICO BORDER THROUGH THURSDAY. COVERAGE OF THUNDERSTORMS WILL
THEN GRADUALLY INCREASE FRIDAY THROUGH SUNDAY AS DEEPER MOISTURE
RETURNS TO THE AREA. THEREAFTER...SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL PREVAIL INTO THE MIDDLE OF NEXT WEEK.
&&
.DISCUSSION...UPPER LEVEL RIDGE WAS IN PLACE OVER THE CENTRAL CONUS
WITH A WEAK SHORTWAVE TROF OVER THE GREAT BASIN AND CNTRL CA. AREA
SFC TEMPS ACROSS SE AZ CLIMBING INTO THE 90S ACROSS MOST VALLEY
LOCATIONS THIS AFTERNOON WITH SOME LOCATIONS LIKELY REACHING THE
TRIPLE DIGITS LATER ON. VISIBLE SATELLITE IMAGERY WAS SHOWING SOME
POPCORN CU OVER MAINLY THE HIGHER ELEVATIONS...AND A FEW TALLER
BUILDUPS OVER THE CHIRICAHUA MTNS IN ERN COCHISE CNTY WITH A FEW
WEAK RETURNS SHOWING UP ON RADAR IN ASSOCIATION WITH THESE BUILDUPS.
SFC DEWPOINTS SLIGHTLY HIGHER IN WRN LOCALES TODAY...INCLUDING +6
DEGS F AT KTUS AND +7 DEGS F AT KOLS AS OPPOSED TO 24 HRS AGO. 12Z
KTWC RAOB THIS MORNING INDICATED TOTAL PRECIP WATER WAS LESS THAN 1
INCH WHICH IS HELPING TO INHIBIT THUNDERSTORM DEVELOPMENT TODAY.
HI-RES MODELS INCLUDING THE HRRR AND TWO LOCAL WRF MODELS LIMITING
ANY SHWR ACTIVITY TO AREAS OF AZ ADJACENT TO THE NM AND
INTERNATIONAL BORDERS THIS AFTERNOON. THE CURRENT EXPECTATION IS FOR
ANY SHWRS/STMS THAT DEVELOP TO BE SHORT-LIVED WITH LIGHT PRECIP AMTS
AND ENDING AROUND OR SHORTLY AFTER 00Z THIS EVE. THAT SAID...VISIBLE
SATELLITE IMAGERY WAS SHOWING NUMEROUS BUILDUPS NEAR THE SONORA/
CHIHUAHUA BORDER THIS AFTERNOON WITH LIGHTNING STRIKES NOT TOO FAR
FROM THE US BORDER. IF OUTFLOWS FROM THESE STORMS DO ADVANCE NWD
INTO SE AZ TONIGHT...EXTREME SERN PORTIONS MAY SEE INCREASED CLOUD
COVER WITH PERHAPS SOME LIGHT SHWR ACTIVITY.
HEADING INTO THIS WEEKEND...HIGH PRESSURE RIDGE AXIS WILL EXTEND
FROM THE TX PANDHANDLE SWWD THRU BAJA CALIFORNIA WITH THE GREAT
BASIN TROF WEAKENING AND LIFTING OFF TO THE EAST. FOR A SHORT
TIME...WEAK ZONAL FLOW WILL SET UP OVER THE MAJORITY OF THE CONUS.
LATE IN THE WKEND ANOTHER TROF WILL DROP SWD ALONG THE PAC COASTLINE
AS HIGH PRESSURE RETURNS TO A MORE FAVORABLE LOCATION FOR DEEPER
MOISTURE ADVECTION AND SUBSEQUENT SHWR/TSTORM ACTIVITY ACROSS SE AZ.
DIFFERENCES STILL EXIST BETWEEN EACH OF THE MODELS ON THE DAY THAT
MORE WIDESPREAD SHOWERS/TSTORMS WILL RETURN TO THE AREA. WITHOUT
GOING INTO ALL THAT DETAIL...THE OFFICIAL FORECAST WILL SHOW A
GRADUAL DAILY INCREASE IN SHWRS/TSTMS FRI-SUN. THUS...SCATTERED
MAINLY AFTERNOON/EVENING SHWRS/TSTMS MAY RETURN AS EARLY AS
SAT...THOUGH ALMOST CERTAINLY BY SUN. DEEPER SELY FLOW WILL RETURN
EARLY NEXT WEEK...WHICH IS EXPECTED TO YIELD THE DAILY CYCLE OF
SCATTERED MAINLY AFTERNOON/EVENING SHWRS/TSTMS.
A VERY GRADUAL AND WEAK DAILY COOLING TREND WILL OCCUR THUR-SAT
FOLLOWED BY NO SIGNIFICANT CHANGE IN DAYTIME TEMPS SUN-WED.
&&
.AVIATION...VALID THRU 07/23Z.
ISOLATED -TSRA/-SHRA NEAR THE NEW MEXICO BORDER...ESPECIALLY ACROSS
THE CHIRICAHUA MOUNTAINS NE OF KDUG THRU THE EARLY EVENING HOURS
TONIGHT AND AGAIN AFT 07/21Z. CLOUDS THRU 07/06Z AND AFT 07/19Z...
SKC-FEW CLOUDS AT 10-13K FT AGL WEST OF KTUS...WITH KTUS VICINITY
EWD FEW-SCT CUMULUS CLOUDS AT 8-12K FT AGL...AND SCT-BKN CLOUDS
ABOVE 20K FT AGL MAINLY SE OF KTUS. MOSTLY CLEAR SKIES EXPECTED
BETWEEN 07/06Z AND 07/19Z. SURFACE WIND MAINLY LESS THAN 10 KTS...
ALTHOUGH A FEW GUSTS TO AROUND 20 KTS MAY OCCUR THRU THE EARLY
EVENING HOURS TONIGHT...AND AGAIN THURSDAY AFTERNOON. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS ARE EXPECTED THROUGH THURSDAY EXCEPT
FOR ISOLATED AFTERNOON/EARLY EVENING THUNDERSTORMS MAINLY NEAR THE
NEW MEXICO BORDER. ISOLATED TO SCATTERED AFTERNOON AND EVENING
SHOWERS AND THUNDERSTORMS WILL RETURN ON FRIDAY...WITH THE COVERAGE
OF THE THUNDERSTORMS INCREASING THIS WEEKEND. AFTERNOON WINDS WILL
GENERALLY BE LESS THAN 15 MPH...EXPECT FOR STRONG AND GUSTY WINDS
NEAR ANY THUNDERSTORMS.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
DISCUSSION...FRENCH
AVIATION/FIRE WEATHER...ZELL
AREA FORECAST DISCUSSION
NWS TUCSON AZ
935 AM MST WED AUG 6 2014
.SYNOPSIS...DRIER AIR WILL LIMIT THUNDERSTORMS TO MAINLY NEAR THE
NEW MEXICO BORDER THROUGH THURSDAY. THE COVERAGE OF THUNDERSTORMS
WILL THEN INCREASE FRIDAY THROUGH SUNDAY AS DEEPER MOISTURE RETURNS
TO THE AREA. THEREAFTER...SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS WILL PREVAIL INTO THE MIDDLE OF NEXT WEEK. A VERY
GRADUAL COOLING TREND WILL OCCUR BY THIS WEEKEND.
&&
.DISCUSSION...CLEAR SKIES PREVAIL ACROSS SE AZ AT THIS TIME EXCEPT
FOR A FEW CIRRIFORM CLOUDS ACROSS SERN SECTIONS. DEWPOINTS AT LOWER
ELEVATIONS VALID 16Z RANGED FROM THE 50S-LOWER 60S F. THESE TEMPS
FROM KTUS WWD WERE ABOUT 5 DEGS F HIGHER VERSUS 24 HOURS AGO...BUT
WERE NEARLY 5-10 DEGS F LOWER ACROSS ERN SECTIONS VERSUS THIS TIME
TUE. 06/12Z KTWC SOUNDING TOTAL PRECIP WATER WAS 0.94 INCH...OR JUST
BELOW THE 25TH PERCENTILE OF PRECIP WATER VALUES FOR THIS TIME OF
YEAR. THE 24 HR TEMP CHANGE PLOT YIELDED MINIMAL CHANGE IN THE
SURFACE-500 MB LAYER...BUT EXHIBITED WARMING OF ABOUT 2-5 DEGS C IN
THE 500-300 MB LAYER. 06/12Z UPPER AIR PLOTS DEPICTED RIDGE AXIS
EXTENDING FROM CENTRAL BAJA CALIFORNIA EWD ACROSS SOUTH TEXAS...AND
A WEAK TROUGH WAS OVER THE GREAT BASIN AND CENTRAL CALIFORNIA. LIGHT
GENERALLY SWLY FLOW PREVAILED OVER SE AZ.
06/12Z UNIV OF AZ WRF-NAM AND 06/14Z RUC HRRR WERE SIMILAR WITH
DEPICTING A PRECIP ECHOES TO INITIALLY DEVELOP ACROSS THE CHIRICAHUA
MOUNTAINS AROUND 18Z-19Z TODAY. PRECIP ECHOES WERE THEN PROGGED TO
REMAIN MAINLY NEAR THE SERN AZ/SWRN NEW MEXICO BORDER THIS AFTERNOON
INTO THIS EVENING. A FEW ECHOES WERE ALSO PROGGED TO BE AS FAR WEST
AS THE HUACHUCA MOUNTAINS SW OF SIERRA VISTA THIS AFTERNOON/EVENING.
06/12Z NAM CONTINUED TO DEPICT PRECIP ECHOES MOSTLY ACROSS THE WHITE
MOUNTAINS LATE TONIGHT/EARLY THUR MORNING.
THESE SOLUTIONS ARE ESSENTIALLY SIMILAR TO THE INHERITED OFFICIAL
FORECAST FORECAST EXCEPT FOR THE POSSIBILITY OF PRECIP LATE TONIGHT.
WILL AWAIT RECEIPT OF THE 06/12Z GFS/ECMWF PRIOR TO MAKING ANY
CHANGES TO THE SHORT-TERM PORTION OF THE FORECAST.
HIGH PRESSURE IS PROGGED TO BE CENTERED OVER WEST TEXAS THUR AS THE
WEAK UPPER TROUGH CONTINUES OVER THE GREAT BASIN REGION. ASSUMING NO
OUTFLOWS FROM CONVECTIVE COMPLEXES OVER SONORA TONIGHT...THEN
FORECAST CONFIDENCE FOR THUR REMAINS HIGH. HOWEVER...AM SOMEWHAT
CONCERNED THAT POPS FOR THUR AND THUR NIGHT MAY BE UNDERDONE IF
OUTFLOWS ADVANCE NWD INTO SE AZ TONIGHT. AT ANY RATE...EXPECT
ISOLATED SHOWERS/TSTMS MAINLY SE OF A HANNAGAN MEADOW-SAFFORD-SIERRA
VISTA LINE THUR AFTERNOON/EVENING.
PRECIP CHANCES WILL INCREASE STARTING FRI AND WILL CONTINUE TO
INCREASE THIS WEEKEND AS DEEPER MOISTURE RETURNS TO THE AREA. THERE
CONTINUED TO BE DIFFERENCES AMONGST THE VARIOUS NWP MODELS REGARDING
WHICH DAY WILL BE FAVORED FOR A MORE SIGNIFICANT INCREASE OF SHOWERS/
TSTMS. IN ESSENCE...THE 06/12Z NAM FAVORED FRI AS A POTENTIAL
SIGNIFICANT INCREASE IN COVERAGE OF SHOWERS/TSTMS. MEANWHILE...THE
06/00Z ECMWF FAVORED SAT FOR HIGHER COVERAGE OF SHOWERS/TSTMS...AND
THE 06/00Z GFS DELAYED THE ONSET OF MORE SUBSTANTIAL CONVECTIVE
ACTIVITY UNTIL SUN.
THE OFFICIAL FORECAST DEPICTS A GRADUAL DAILY INCREASE IN SHOWERS/
TSTMS FRI-SUN. THUS...SCATTERED MAINLY AFTERNOON/EVENING SHOWERS/
TSTMS MAY RETURN AS EARLY AS SAT...THOUGH ALMOST CERTAINLY BY SUN. A
FAIRLY DEEP GENERALLY SELY FLOW REGIME IS THEN PROGGED TO OCCUR
MON-TUE IN RESPONSE TO HIGH PRESSURE ALOFT CENTERED OVER NRN NEW
MEXICO. THIS PATTERN IS EXPECTED TO YIELD THE DAILY CYCLE OF
SCATTERED MAINLY AFTERNOON/EVENING SHOWERS/TSTMS. ENOUGH MOISTURE
APPEARS TO EXIST TO SUPPORT AT LEAST A SLIGHT CHANCE OF SHOWERS/
TSTMS DURING THE OVERNIGHT/EARLY MORNING HOURS MON-TUE.
HIGH TEMPS TODAY WILL BE NEARLY IDENTICAL TO TEMPS ACHIEVED TUE
AFTERNOON. A VERY GRADUAL DAILY COOLING TREND WILL THEN OCCUR
THUR-SAT FOLLOWED BY NO SIGNIFICANT CHANGE IN DAYTIME TEMPS SUN-TUE.
&&
.AVIATION...VALID THRU 7/18Z.
EXPECT ISOLATED -TSRA/-SHRA NEAR THE NEW MEXICO BORDER...AND
ESPECIALLY ACROSS THE CHIRICAHUA MOUNTAINS NE OF KDUG THIS AFTERNOON
AND THIS EVENING. OTHERWISE...CLEAR SKIES WILL PREVAIL WEST OF KTUS
THRU THURSDAY MORNING. KTUS VICINITY EWD WILL HAVE A FEW TO
SCATTERED CUMULUS CLOUDS AT 8-12K FT AGL THIS AFTERNOON AND EARLY
THIS EVENING...WITH SCATTERED TO BROKEN CLOUDS ABOVE 20K FT AGL
MAINLY SE OF KTUS AT OTHER TIMES. SURFACE WINDS WILL BE MAINLY LESS
THAN 10 KTS ALTHOUGH A FEW GUSTS TO AROUND 20 KTS MAY OCCUR THIS
AFTERNOON. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...DRY CONDITIONS WILL OCCUR THROUGH THURSDAY EXCEPT
FOR ISOLATED AFTERNOON THUNDERSTORMS MOSTLY NEAR THE NEW MEXICO
BORDER. EXPECT ISOLATED TO SCATTERED MAINLY AFTERNOON AND EVENING
THUNDERSTORMS TO RETURN ON FRIDAY WITH COVERAGE OF THUNDERSTORMS TO
INCREASE THIS WEEKEND. THEREAFTER...SCATTERED MAINLY AFTERNOON AND
EVENING THUNDERSTORMS WILL PREVAIL EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
318 PM MDT WED AUG 6 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 317 PM MDT WED AUG 6 2014
CURRENTLY...
WEAK BOUNDARY WAS MOVING SOUTH ACROSS THE EASTERN PLAINS. THIS
BOUNDARY WAS INITIATING SOME CONVECTION OVER KIOWA COUNTY AT 2 PM.
GENERALLY N OF HIGHWAY 50 WINDS WERE FROM A WEAK NORTHERLY COMPONENT
WHILE WINDS WERE GENERALLY LIGHT AND VARIABLE SOUTH OF 50.
OVER THE MTNS...ESPECIALLY INTERIOR MTNS...IT HAS DRIED OUT QUITE A
BIT WITH DWPTS IN THE 30S...WITH A FEW 20S AT HIGHER ELEVATIONS. IT
ALSO APPEARS TO BE DRIER ALOFT AS CLOUDS ARE NOTICEABLY MUCH LESS
ONCE YOU GET SOUTH OF US-50.
REST OF TODAY INTO TONIGHT...
MAIN CONCERN IN THE IMMEDIATE SHORT TERM WILL BE THE WALDO BURN
SCAR. HRRR SHOWING BEST CHANCE OF PRECIP THIS AFTERNOON MAINLY OVER
C MTNS...GREATER PIKES PEAK REGION AND KIOWA COUNTY. HAVE ALREADY
INCREASED POPS THIS AREA IN EARLIER UPDATES. ALTHOUGH FLASH FLOODING
NOT LIKELY OVER BURN SCARS...ONE HEAVY SHOWER IN THE WRONG PLACE CAN
EASILY CAUSE PROBLEMS.
FOR LATER TONIGHT...LOW LVL MOISTURE WILL LIKELY
INCREASE...ESPECIALLY OVER THE FAR E PLAINS AS 60 DWPTS CURRENTLY IN
SW NEB ARE SHUNTED SOUTHWARD BEHIND THE FRONT. WE WILL LIKELY SEE
SOME LOW CLOUDS TOMORROW MORNING...ESPECIALLY OVER THE FAR SE PLAINS
IN THE GREATER KIOWA COUNTY REGION. NAM GUIDANCE HAS SOME PRECIP
LATE TONIGHT THIS REGION BUT IT IS LIKELY A BIT OVERDONE.
WITH DRIER AIR OVER THE MTNS...WILL LIKELY SEE ANOTHER COOL NIGHT
OVER THE HIGHER TRRN...ESPECIALLY ALONG THE CONTDVD AND HIGH
VALLEYS.
TOMORROW...
EXPECT MORE CONVECTION OVER THE AREA TOMORROW AND HAVE POPS DRAWN UP
EVERYWHERE OVER THE CWA BY TOMORROW AFTERNOON. PWAT VALUES INCREASE
TO OVER AN INCH OVER THE PLAINS AND AREA WILL LIKELY BE FEELING THE
LEADING EDGE OF A WELL DEFINED TROUGH OVER E UTAH. CONVECTION SHOULD
INITIATE AROUND ITS NORMAL TIME OVER THE MTNS (NOONISH) AND THEN
INCREASE AND MOVE EAST OVER THE PLAINS. BEST CHANCE OF POPS WILL BE
OVER C MTNS...PIKES PEAK AREA AND FAR E PLAINS...ESPECIALLY BY LATE
AFTERNOON. FLOODING THREAT ON THE BURN SCARS WILL BE HIGHER TOMORROW
THAN TODAY. STORMS MAY BE A BIT MORE ORGANIZED TOMORROW DUE TO A BIT
BETTER DEEP SHEAR AND HIGHER CAPE VALUES. AN ISOLD SVR STORM CANT BE
RULED OUT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 317 PM MDT WED AUG 6 2014
.THURSDAY EVENING AND FRIDAY...MAIN CHALLENGE WILL BE THE MOVEMENT
OF THE MCS WHICH DEVELOPS OVER NORTHEAST COLORADO...AND THE
AMOUNT OF MOISTURE AND INSTABILITY FROM THE OUTFLOW. OVER NORTHEAST
COLORADO MOST MODELS DEVELOP CONVECTION THURSDAY AFTERNOON AND
EVENING...WHICH MOVES TO THE EAST OR EAST SOUTHEAST DURING THE
EVENING. BELIEVE MOST OF THE CONVECTION WILL STAY TO THE NORTH OF
THE CWA...BUT THERE IS THREAT FOR SOME OF THE CONVECTION TO
DEVELOP OVER THE PALMER DIVIDE REGION AND MOVE TO THE SOUTHEAST
DURING THURSDAY EVENING. POPS GRIDS KEEP SCATTERED POPS OVER THESE
REGIONS FOR THURSDAY EVENING AND INTO THE OVERNIGHT. ON
FRIDAY...EXPECT OUTFLOW FROM THE MCS TO INCREASE LOW LEVEL
MOISTURE OVER THE EASTERN PLAINS AND INTERSTATE 25 CORRIDOR. CANNOT
GET VERY SPECIFIC ABOUT AMOUNT OF MOISTURE AND INSTABILITY IN THE
OUTFLOW FROM MCS...BUT HUNCH IS OUTFLOW WILL BE STRONGER THAN MOST
MODELS SUGGEST. IF THIS IS THE CASE...LOW LEVELS COULD BECOME MORE
UNSTABLE DUE TO INCREASED MOISTURE. HOWEVER...IF THE LOW LEVELS
ARE TOO CLOUDY OR COOL...ATMOSPHERE MAY BE STABLE ON THE PLAINS.
DECIDED TO GO WITH SCATTERED POPS MAINLY ALONG PALMER DIVIDE AND
PORTIONS OF THE EASTERN PLAINS ON FRIDAY. NAM12 HAS A POTENT AND
COMPACT SHORTWAVE MOVING OVER EASTERN COLORADO FRIDAY...AND CAPES
OVER PORTIONS OF THE SOUTHEAST PLAINS ARE OVER 2000 J/KG. THINK
THIS MAY BE OVERDONE...BUT HIGHLIGHTS POTENTIAL FOR STRONGER
CONVECTION FRIDAY. FURTHER WEST...MONSOON PLUME IS MOSTLY
SUPPRESSED TO THE SOUTH...WITH ISOLATED TO SCATTERED POPS OVER THE
MOUNTAINS.
.SATURDAY AND SUNDAY...UPPER TROUGH REMAINS NEAR THE WEST COAST
WITH THE AXIS OF THE 500 MB RIDGE OVER COLORADO. SOUTH TO
SOUTHWEST FLOW ALOFT WILL START BRINGING MORE MIDDLE AND UPPER
LEVEL MOISTURE INTO THE REGION. POPS INCREASE OVER THE MOUNTAINS
ESPECIALLY ON SUNDAY. WEAK UPSLOPE FLOW COULD CONTINUE WITH LOW
LEVEL MOISTURE REMAINING OVER THE PLAINS.
.MONDAY THROUGH WEDNESDAY...GFS AND EC SUGGEST THE BEGINNING OF A
PATTERN CHANGE WHICH WILL RESULT IN THE UPPER RIDGE RETROGRADING
AND NORTHWEST FLOW DEVELOPING OVER THE REGION. MORE SUBTLE
FEATURES WILL AFFECT THE DAY TO DAY WEATHER. CURRENT INDICATIONS
ARE A DECREASE IN MID LEVEL MOISTURE BY MID WEEK FOR A DECREASED
CHANCE OF DIURNAL CONVECTION OVER THE MOUNTAINS. ABUNDANT LOWER
LEVEL MOISTURE ON THE PLAINS WILL GRADUALLY MOVE EAST OF THE
STATE. LIKELY STILL ENOUGH MOISTURE FOR DIURNAL CONVECTION...BUT
PATTERN CHANGES SUGGESTS LOWER COVERAGE WITH LESS INTENSITY.
--PGW--
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 317 PM MDT WED AUG 6 2014
ISOLD TSRA WILL BE POSSIBLE LATE THIS AFTERNOON AND EARLY EVENING
OVER KCOS...WITH A BETTER CHANCE OF TSRA TOMORROW AFTERNOON.
OTHERWISE...VFR EXPECTED.
FOR KPUB AND KALS...VFR NEXT 24. THERE WILL BE A SLIGHT CHANCE OF
TSRA OVER THESE TWO SITES TOMORROW AFTERNOON.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...HODANISH
LONG TERM...PGW
AVIATION...HODANISH
AREA FORECAST DISCUSSION
NWS DES MOINES IA
329 PM CDT WED AUG 6 2014
.SHORT TERM /TONIGHT/...
ISSUED AT 328 PM CDT WED AUG 6 2014
ANOTHER ROUND OF HEAVY RAINFALL IS POSSIBLE FOR THE CWA
TONIGHT...MAINLY SOUTHERN PORTIONS. TWO SHORTWAVES...PRESENTLY
MOVING THROUGH SE SOUTH DAKOTA AND NORTH CENTRAL KS...WILL HELP
PROVIDE THE LARGE-SCALE FORCING FOR OVERNIGHT PCPN. LLJ IS EXPECTED
TO DEVELOP AGAIN TONIGHT AND POINT INTO IA...PROVIDING AMPLE
MOISTURE. PWATS ARE PROGGED TO BE INVOF THE 2.0 IN RANGE...WHICH
AGAIN WILL BE AROUND +2 SD VS CLIMO. WARM CLOUD DEPTHS WILL APPROACH
THE 12 KFT RANGE. MODEL FCST SOUNDINGS DO TEND TO MOISTEN THE COLUMN
ACROSS SOUTHERN IA THIS EVENING...MORE SO THAN LAST NIGHT...WHICH
WOULD TEND TO SUPPORT THE HEAVY RAIN THREAT TONIGHT.
MODEL SOLUTIONS DO VARY ON THE AMOUNT OF FORCING AND RESULTING
RAINFALL. THE NAM IS THE WETTEST AND BRINGS A RIBBON OF FORCING
ALONG WITH STRONG THETA-E ADVECTION INTO SOUTH CENTRAL AND SOUTHWEST
IA. THE GFS ON THE OTHER HAND IS NOT AS INTENSE THAT FAR NORTH. HAVE
TENDED TO SPLIT THE DIFFERENCE...AND EXPECT THE HEAVIEST RAINFALL
TONIGHT TO REMAIN SOUTH OF IA HWY 92.
WILL GO WITH A FLASH FLOOD WATCH FOR SOME OF THE SOUTH CENTRAL AND
SOUTHWEST IA COUNTIES ALONG AND SOUTH OF 92...GIVEN LAST NIGHT/S
HEAVY RAINFALL AND RELATIVELY LOWER FLASH FLOOD GUIDANCE VALUES.
ALTHOUGH AM NOT OVERLY CONCERNED ABOUT FLASH FLOOD POTENTIAL
THERE...CONFIDENCE IS AROUND THE 40 TO 50 PERCENT THRESHOLD WHICH
WOULD BE THE LOW-END FLASH FLOOD WATCH CRITERIA.
SEVERE WEATHER POTENTIAL THIS EVENING AND OVERNIGHT IS MINIMAL BUT
CANNOT BE ENTIRELY RULED OUT. ALTHOUGH CAPE VALUES HAVE INCREASED
THIS AFTN IN SW IA...WITH VALUES APPROACHING THE 1000 TO 1500 J/KG
RANGE. DEEP-LAYER SHEAR IS MINIMAL HOWEVER...WHICH WOULD TEND TO
PRECLUDE ORGANIZED TSTM DEVELOPMENT. ATTM ANTICIPATE THE GREATEST
THREAT WOULD BE HEAVY RAINFALL FROM ANY STORMS THAT DO DEVELOP.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 328 PM CDT WED AUG 6 2014
MAIN CHALLENGES THIS PERIOD WILL BE MAINLY IN THE SHORTER TERM WITH
EVOLUTION OF SYSTEM NEXT 24 HOURS. CURRENTLY SFC SHORT WAVE SOUTH OF
THE AREA WITH BOUNDARY OVER NORTHERN MO AND WEAK TROUGH EXTENDING
ACROSS NORTH CENTRAL IOWA WITH WELL DEFINED DEFORMATION AXIS AND
THETAE AXIS ALOFT ACROSS THE REGION. ISENTROPIC UPGLIDE CONTINUES TO
FEED THIS AREA WHERE PERSISTENT LIGHT RAIN IS FALLING. MODELS HAVENT
QUITE REACHED A CONSENSUS ON THE EVENTUAL DEPARTURE OF THE SYSTEM
FOR THURSDAY/THURSDAY NIGHT. THIS IS IN PART DUE TO THE PERSISTENT
RIDGE AXIS WHICH EXTENDS FROM SOUTHERN CANADA TO THE SOUTHEAST US.
THE GENERAL TREND HAS BEEN FOR A SLOWER TRANSITION OUT OF THE AREA
THURSDAY INTO THURSDAY NIGHT. THURSDAY MORNING MOST OF THE FORCING
WILL REMAIN STRONGEST ACROSS THE SOUTHEAST WITH CONTINUED UPGLIDE
WRAPPING AROUND THE SYSTEM BACK INTO CENTRAL AND NORTHERN IOWA
DURING THE DAY. THOUGH THE H850 MOISTURE CHANNEL WILL GRADUALLY
SHIFT TO THE EAST WITH TIME...LIGHT TO MODERATE RAIN SHOULD CONTINUE
THROUGH MUCH OF THE DAY THURSDAY THEN SLOWLY TAPER OFF DURING THE
EVENING HOURS. BOTH THE EURO/GFS/NAM HIT THE EAST/SOUTHEAST WITH
QUITE A BIT OF QPF FOCUSED BETWEEN 12-18Z USING A SLIGHTLY FARTHER
NORTH TRACK OF THE H850 LOW. WPC CONTINUES TO PREFER A MORE SOUTHERN
SOLUTION MORE IN LINE WITH MESO HRRR AND NMM MODELS. CURRENTLY THE
SYSTEM IS TRACKING FAIRLY WELL WITH ALL MODELS BUT WITH EXPECTED
MESO CONVECTION TO DEVELOP OVER NORTHERN MO THIS EVENING...TRACK
EXPECTED TO END UP BEING FARTHER SOUTH THAN SYNOPTIC MODELS INDICATE
AND CLOSER TO THE HRRR/NMM. FOR NOW WILL TREND TOWARD THAT SOLUTION
...IN LINE WITH WPC AS WELL BUT WILL NEED TO WATCH DURING THE
EVENING SHIFT FOR ANY POTENTIAL ADJUSTMENTS FARTHER NORTH. ANY
DEVIATION NORTH WOULD RESULT IN RAINFALL TOTALS BEING HIGHER IN THE
FORECAST AREA THURSDAY. EVENTUALLY THE SYSTEM BECOMES SHEARED OUT
AND WEAKENS...AND HANGS ON INTO FRIDAY WITH LINGERING SHOWERS OR ISO
THUNDER OVER THE SOUTH. ALREADY INTO THE WEEKEND NOW SOME
UNCERTAINTY REGARDING THE NEXT UPSTREAM WAVE APPROACHING FROM THE
WEST FOR SATURDAY AND SUNDAY. GREAT LAKES HIGH NOW BEING MODELED TO
STRENGTHEN OVER THE REGION AND IS NOW TRENDING TO KEEP AREA DRIER
THAN PREVIOUSLY FORECAST. HAVE REDUCED POP CHANCES FOR BOTH DAYS...
BUT HAVE NOT CUT OUT YET DUE TO CONFIDENCE CONCERNS AND CONSENSUS
WITH NEIGHBORING OFFICES AT THIS POINT. IF TRENDS CONTINUE WITH
TONIGHTS MODEL PACKAGES...THEN FURTHER REDUCTION IN RAIN CHANCES
WILL BE WARRANTED. TEMPERATURES WILL REMAIN COOL THURSDAY WITH
EXTENSIVE CLOUD COVER AND SHOWERS. BY FRIDAY SOME MODERATION IS
EXPECTED WHICH SHOULD CONTINUE INTO THE WEEKEND. NORTHEAST FLOW WILL
DEVELOP BY THURSDAY AFTERNOON AND CONTINUE THROUGH FRIDAY WITH SOME
RISK FOR PATCHY FOG OVERNIGHT AS CLOUDS AND HIGH MOISTURE REMAINS IN
THE BOUNDARY LAYER. LOOKING AHEAD TO NEXT WEEK....LESSENING CHANCES
FOR RAIN WILL CONTINUE THROUGH THE PERIOD AS A RIDGE OF HIGH
PRESSURE REMAINS IN THE AREA. SOME HINT AT RETURN MOISTURE BY NEXT
WEDNESDAY AS A TROUGH DEVELOPS OVER THE HIGH PLAINS AND MOVES INTO
THE CENTRAL PLAINS.
&&
.AVIATION...06/12Z
ISSUED AT 1214 PM CDT WED AUG 6 2014
SFC LOW PRESSURE WILL PUSH EASTWARD INVOF SRN IA/NRN MO DURING THE
FCST PD BRINGING WIDESPREAD SHRA/TSRA. WITHIN SHRA/TSRA FLIGHT RULES
WILL BE REDUCED TO MVFR OR LOWER...WITH IFR OR LOWER CONDITIONS
POSSIBLE OVERNIGHT AFTER 03/06Z. MOST OF THE SHRA/TSRA WILL PULL OUT
OF THE REGION ON THU MORNING BUT WILL LEAVE MVFR CONDS FOR MUCH OF
THE MORNING.
&&
.HYDROLOGY...
ISSUED AT 328 PM CDT WED AUG 6 2014
THREAT OF HEAVY RAINS WILL PERSIST THROUGH TODAY THURSDAY
WITH AMPLE MOISTURE IN PLACE BEING TRANSPORTED INTO THE STATE.
URBAN AREAS WOULD BE MOST LIKELY TO EXPERIENCE ANY FLOODING
ISSUES AS MOST RURAL LOCATIONS HAVE DRY ANTECEDENT CONDITIONS.
MINIMAL RISES ARE ANTICIPATED ON AREA RIVERS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH FROM 8 PM CDT THIS EVENING THROUGH THURSDAY
MORNING FOR ADAIR-CLARKE-DECATUR-LUCAS-MADISON-RINGGOLD-UNION-
WAYNE.
&&
$$
SHORT TERM...ZOGG
LONG TERM...REV
AVIATION...ZOGG
HYDROLOGY...ZOGG
AREA FORECAST DISCUSSION
NWS JACKSON KY
125 PM EDT WED AUG 6 2014
.UPDATE...
ISSUED AT 1231 PM EDT WED AUG 6 2014
HAVE MADE ADJUSTMENTS TO HOURLY NDFD FORECAST BASED ON LATEST
OBSERVATIONAL TRENDS. THE HRRR CONTINUES TO POINT TOWARDS ISOLATED
TO SCATTERED CONVECTION THIS AFTERNOON...AND WILL CONTINUE TO CARRY
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
FORECAST. COVERAGE LOOKS TO BE LIMITED HOWEVER.
UPDATE ISSUED AT 957 AM EDT WED AUG 6 2014
FORECAST CONTINUES TO LOOK ON TRACK...BUT WILL MAKE SOME MINOR CHANGES TO
THE PRECIPITATION FORECAST. ISOLATED VERY LIGHT SHOWERS OR POSSIBLY
JUST SPRINKLES ARE OVER THE FAR SOUTHEAST PART OF THE FORECAST AREA
AT 1350Z. MORE SIGNIFICANT SHOWERS ARE OVER CENTRAL WV. BASED ON 12Z
SOUNDINGS AND CURRENT RADAR TRENDS WILL DROP ANY RAIN CHANCE FOR THE
NEXT FEW HOURS OVER THE CENTRAL AND NORTHWEST PART OF THE AREA...AND
REMOVE ALL THUNDER CHANCES UNTIL 18Z. OTHERWISE WILL KEEP THE SAME
RAIN PROBABILITIES FOR THIS AFTERNOON WITH ISOLATED TO SCATTERED
THUNDERSTORM COVERAGE EXPECTED DURING THE AFTERNOON.
UPDATE ISSUED AT 743 AM EDT WED AUG 6 2014
FORECAST SEEMS TO BE WELL ON TRACK SO FAR THIS MORNING...WITH A FEW
ISOLATED SHOWERS DEVELOPING AND PUSHING THROUGH THE CWA. LOADED IN
THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE CURRENT CONDITIONS WERE REFLECTED IN THE NEAR TERM FORECAST
OTHERWISE NO SIGNIFICANT UPDATES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 324 AM EDT WED AUG 6 2014
UNDER NORTHWEST FLOW ALOFT...A COLD FRONT WILL DROP SOUTHWARD
THROUGH EAST KENTUCKY TODAY AND STALL OUT TO OUR SOUTH TONIGHT AND
THURSDAY. DESPITE THE PRESENCE OF THE FRONT...NOT TOO ENTHUSED ABOUT
SHOWER AND THUNDERSTORM DEVELOPMENT AS FORECAST SOUNDINGS SHOW A MID
LEVEL CAP IN PLACE THROUGH MOST OF THE DAY. A PEEK AT MOS GUIDANCE
DOES NOT INCREASE ENTHUSIASM FOR RAIN EITHER. I WOULD BE INCLINED TO
REDUCE RAIN CHANCES TODAY WERE IT NOT FOR A FEW SHOWERS SHOWING UP
ON RADAR OVER CENTRAL KENTUCKY AND TO THE NORTH WITH THE FRONT.
SO...INSTEAD WILL HOLD WITH 20-30 POPS DURING THE DAY AND TAPER
THESE OFF DURING THE EVENING HOURS. THE MODEL CONSENSUS NOW IS FOR A
DRY PERIOD FROM LATE WEDNESDAY NIGHT THROUGH THE DAY ON THURSDAY
BEFORE THE FRONT WAFFLES BACK NORTH DURING THE LONG TERM PERIOD AND
WILL REMOVE ANY MENTION OF RAIN AFTER MIDNIGHT TONIGHT. NOT MUCH
CHANGE ANTICIPATED WITH TEMPS THE NEXT 36 HOURS WITH HIGHS ONLY
DROPPING A COUPLE DEGREES BEHIND THE FRONT FOR THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 324 AM EDT WED AUG 6 2014
FINALLY...MORE ZONAL FLOW WILL TAKE HOLD OF THE REGION DURING THE
MID TERM AS A STRONG UPPER LEVEL LOW OVER EASTERN CANADA PUSHES
TOWARDS THE NORTHERN ATLANTIC. WITHOUT MUCH UPPER LEVEL FORCING...A
SURFACE FRONT WILL BECOME NEARLY STATIONARY JUST SOUTH OF KY...AND
WILL REMAIN SO THROUGH MUCH OF THE FORECAST PERIOD. WHILE KY WILL
FIND ITSELF ON THE COOLER SIDE OF THE FRONT AND UNDER THE INFLUENCE
OF SURFACE HIGH PRESSURE...WE WILL NOT BE IMMUNE TO PRECIP CHANCES.
EXPECT THE FRONTAL LOCATION TO OSCILLATE NORTHWARD AND SOUTHWARD
SLIGHTLY. THIS WILL BRING CHANCES OF SHOWERS AND THUNDERSTORMS TO
THE EASTERN KY REGION THROUGH THE WEEKEND...WITH BEST CHANCES DURING
THE AFTERNOON AND EVENING HOURS WHEN DIURNAL INFLUENCES EXPAND THE
RANGE OF THE FRONTAL PRECIP.
FRIDAY AND SATURDAY ARE STILL SHOWING THE BEST POTENTIAL FOR
WIDESPREAD PRECIP COVERAGE. AND WITH HIGH 6 HOUR PWAT VALUES /LATEST
NAM AND GFS ARE POINTING AT OVER 2 INCHES IN SOME LOCATIONS/...AS
WELL AS GENERALLY WEAK STORM MOTION /LESS THAN 10 KNOTS/...STILL
EXPECTING HEAVY RAINS AND LOCALIZED FLASH FLOODING TO BE THE MAIN
CONCERN. ADDED MODERATE RAINFALL WORDING BACK INTO WEATHER GRIDS FOR
THIS TIME PERIOD.
LONG RANGE MODELS ARE POINTING AT THE LONG WAVE PATTERN BECOMING
MORE AMPLIFIED LATE IN THE EXTENDED. THIS WILL INTRODUCE MORE
SHORTWAVES TO THE OHIO RIVER VALLEY REGION. GIVEN THE MODEL VARIANCE
THIS FAR IN THE FORECAST...WILL STICK CLOSE TO THE ALLBLEND FOR
POPS. EXPECT THE FIRST WAVE TO MOVE THROUGH THE REGION DURING THE
DAY MONDAY...WITH LINGERING PRECIP CHANCES MONDAY NIGHT AND THROUGH
THE DAY TUESDAY. IF THE SHORTWAVE CONTINUES ITS TRACK EASTWARD...IT
SHOULD PULL THE STATIONARY FRONT TO OUR SOUTH WITH IT AS WELL. THIS
WILL BRING OUR FIRST CHANCE FOR DRY WEATHER BY LATE IN THE DAY
WEDNESDAY. HOWEVER...CONFIDENCE IN THE EXACT TIMING OF THIS IS VERY
LOW GIVEN THE LARGE MODEL VARIABILITY THIS FAR OUT IN THE FORECAST.
TEMPERATURES HAVE CHANGED VERY LITTLE OVER THE PAST FEW PACKAGE
UPDATES. THE RETURN OF ZONAL FLOW WILL WORK TO MODERATE TEMPERATURES
TO MORE SEASONABLE VALUES WITH LITTLE DAY TO DAY FLUCTUATION.
HOWEVER...THE AMOUNT OF CLOUD COVER EXPECTED EACH DAY WILL HINDER
TEMPS FROM REACHING THEIR MAXIMUM POTENTIAL IN THE AFTERNOON...AND
WILL ALSO PREVENT MAXIMUM RADIATIONAL COOLING OVERNIGHT. LOW TO MID
80S ARE EXPECTED FOR HIGHS THROUGH THE EXTENDED PERIOD...WHILE
OVERNIGHT LOWS WILL BE A PLEASANT MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 125 PM EDT WED AUG 6 2014
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED THIS
AFTERNOON AS A WEAK COLD FRONT DROPS SOUTH ACROSS THE AREA. WILL
CONTINUE TO MENTION VCTS IN THE TAFS FOR THE REMAINDER OF THE
AFTERNOON...BUT ORGANIZED STORMS ARE NOT EXPECTED. SOME FOG IS
FORECAST TO FORM LATE TONIGHT...MAINLY RESULTING IN MVFR
VISIBILITIES. ONCE ANY FOG LIFTS THURSDAY MORNING VFR CONDITIONS WILL
PREVAIL FOR THE REMAINDER OF THE DAY. WINDS WILL REMAIN LIGHT THROUGH
THE FORECAST PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...ABE
LONG TERM...JMW
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS JACKSON KY
1232 PM EDT WED AUG 6 2014
.UPDATE...
ISSUED AT 1231 PM EDT WED AUG 6 2014
HAVE MADE ADJUSTMENTS TO HOURLY NDFD FORECAST BASED ON LATEST
OBSERVATIONAL TRENDS. THE HRRR CONTINUES TO POINT TOWARDS ISOLATED
TO SCATTERED CONVECTION THIS AFTERNOON...AND WILL CONTINUE TO CARRY
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS IN THE AFTERNOON
FORECAST. COVERAGE LOOKS TO BE LIMITED HOWEVER.
UPDATE ISSUED AT 957 AM EDT WED AUG 6 2014
FORECAST CONTINUES TO LOOK ON TRACK...BUT WILL MAKE SOME MINOR CHANGES TO
THE PRECIPITATION FORECAST. ISOLATED VERY LIGHT SHOWERS OR POSSIBLY
JUST SPRINKLES ARE OVER THE FAR SOUTHEAST PART OF THE FORECAST AREA
AT 1350Z. MORE SIGNIFICANT SHOWERS ARE OVER CENTRAL WV. BASED ON 12Z
SOUNDINGS AND CURRENT RADAR TRENDS WILL DROP ANY RAIN CHANCE FOR THE
NEXT FEW HOURS OVER THE CENTRAL AND NORTHWEST PART OF THE AREA...AND
REMOVE ALL THUNDER CHANCES UNTIL 18Z. OTHERWISE WILL KEEP THE SAME
RAIN PROBABILITIES FOR THIS AFTERNOON WITH ISOLATED TO SCATTERED
THUNDERSTORM COVERAGE EXPECTED DURING THE AFTERNOON.
UPDATE ISSUED AT 743 AM EDT WED AUG 6 2014
FORECAST SEEMS TO BE WELL ON TRACK SO FAR THIS MORNING...WITH A FEW
ISOLATED SHOWERS DEVELOPING AND PUSHING THROUGH THE CWA. LOADED IN
THE LATEST OBSERVATIONAL DATA FOR TEMPS...DEW POINTS...AND WINDS...TO
MAKE SURE CURRENT CONDITIONS WERE REFLECTED IN THE NEAR TERM FORECAST
OTHERWISE NO SIGNIFICANT UPDATES NEEDED AT THIS TIME.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 324 AM EDT WED AUG 6 2014
UNDER NORTHWEST FLOW ALOFT...A COLD FRONT WILL DROP SOUTHWARD
THROUGH EAST KENTUCKY TODAY AND STALL OUT TO OUR SOUTH TONIGHT AND
THURSDAY. DESPITE THE PRESENCE OF THE FRONT...NOT TOO ENTHUSED ABOUT
SHOWER AND THUNDERSTORM DEVELOPMENT AS FORECAST SOUNDINGS SHOW A MID
LEVEL CAP IN PLACE THROUGH MOST OF THE DAY. A PEEK AT MOS GUIDANCE
DOES NOT INCREASE ENTHUSIASM FOR RAIN EITHER. I WOULD BE INCLINED TO
REDUCE RAIN CHANCES TODAY WERE IT NOT FOR A FEW SHOWERS SHOWING UP
ON RADAR OVER CENTRAL KENTUCKY AND TO THE NORTH WITH THE FRONT.
SO...INSTEAD WILL HOLD WITH 20-30 POPS DURING THE DAY AND TAPER
THESE OFF DURING THE EVENING HOURS. THE MODEL CONSENSUS NOW IS FOR A
DRY PERIOD FROM LATE WEDNESDAY NIGHT THROUGH THE DAY ON THURSDAY
BEFORE THE FRONT WAFFLES BACK NORTH DURING THE LONG TERM PERIOD AND
WILL REMOVE ANY MENTION OF RAIN AFTER MIDNIGHT TONIGHT. NOT MUCH
CHANGE ANTICIPATED WITH TEMPS THE NEXT 36 HOURS WITH HIGHS ONLY
DROPPING A COUPLE DEGREES BEHIND THE FRONT FOR THURSDAY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 324 AM EDT WED AUG 6 2014
FINALLY...MORE ZONAL FLOW WILL TAKE HOLD OF THE REGION DURING THE
MID TERM AS A STRONG UPPER LEVEL LOW OVER EASTERN CANADA PUSHES
TOWARDS THE NORTHERN ATLANTIC. WITHOUT MUCH UPPER LEVEL FORCING...A
SURFACE FRONT WILL BECOME NEARLY STATIONARY JUST SOUTH OF KY...AND
WILL REMAIN SO THROUGH MUCH OF THE FORECAST PERIOD. WHILE KY WILL
FIND ITSELF ON THE COOLER SIDE OF THE FRONT AND UNDER THE INFLUENCE
OF SURFACE HIGH PRESSURE...WE WILL NOT BE IMMUNE TO PRECIP CHANCES.
EXPECT THE FRONTAL LOCATION TO OSCILLATE NORTHWARD AND SOUTHWARD
SLIGHTLY. THIS WILL BRING CHANCES OF SHOWERS AND THUNDERSTORMS TO
THE EASTERN KY REGION THROUGH THE WEEKEND...WITH BEST CHANCES DURING
THE AFTERNOON AND EVENING HOURS WHEN DIURNAL INFLUENCES EXPAND THE
RANGE OF THE FRONTAL PRECIP.
FRIDAY AND SATURDAY ARE STILL SHOWING THE BEST POTENTIAL FOR
WIDESPREAD PRECIP COVERAGE. AND WITH HIGH 6 HOUR PWAT VALUES /LATEST
NAM AND GFS ARE POINTING AT OVER 2 INCHES IN SOME LOCATIONS/...AS
WELL AS GENERALLY WEAK STORM MOTION /LESS THAN 10 KNOTS/...STILL
EXPECTING HEAVY RAINS AND LOCALIZED FLASH FLOODING TO BE THE MAIN
CONCERN. ADDED MODERATE RAINFALL WORDING BACK INTO WEATHER GRIDS FOR
THIS TIME PERIOD.
LONG RANGE MODELS ARE POINTING AT THE LONG WAVE PATTERN BECOMING
MORE AMPLIFIED LATE IN THE EXTENDED. THIS WILL INTRODUCE MORE
SHORTWAVES TO THE OHIO RIVER VALLEY REGION. GIVEN THE MODEL VARIANCE
THIS FAR IN THE FORECAST...WILL STICK CLOSE TO THE ALLBLEND FOR
POPS. EXPECT THE FIRST WAVE TO MOVE THROUGH THE REGION DURING THE
DAY MONDAY...WITH LINGERING PRECIP CHANCES MONDAY NIGHT AND THROUGH
THE DAY TUESDAY. IF THE SHORTWAVE CONTINUES ITS TRACK EASTWARD...IT
SHOULD PULL THE STATIONARY FRONT TO OUR SOUTH WITH IT AS WELL. THIS
WILL BRING OUR FIRST CHANCE FOR DRY WEATHER BY LATE IN THE DAY
WEDNESDAY. HOWEVER...CONFIDENCE IN THE EXACT TIMING OF THIS IS VERY
LOW GIVEN THE LARGE MODEL VARIABILITY THIS FAR OUT IN THE FORECAST.
TEMPERATURES HAVE CHANGED VERY LITTLE OVER THE PAST FEW PACKAGE
UPDATES. THE RETURN OF ZONAL FLOW WILL WORK TO MODERATE TEMPERATURES
TO MORE SEASONABLE VALUES WITH LITTLE DAY TO DAY FLUCTUATION.
HOWEVER...THE AMOUNT OF CLOUD COVER EXPECTED EACH DAY WILL HINDER
TEMPS FROM REACHING THEIR MAXIMUM POTENTIAL IN THE AFTERNOON...AND
WILL ALSO PREVENT MAXIMUM RADIATIONAL COOLING OVERNIGHT. LOW TO MID
80S ARE EXPECTED FOR HIGHS THROUGH THE EXTENDED PERIOD...WHILE
OVERNIGHT LOWS WILL BE A PLEASANT MID TO UPPER 60S.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 650 AM EDT WED AUG 6 2014
A COLD FRONT WILL DROP SOUTHWARD THROUGH OUR AREA DURING THE DAY
TODAY WITH SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING AS IT DOES
SO. WILL INCLUDE A MENTION OF VCTS IN THE TAFS THROUGH 23Z BEFORE
THE FRONT DROPS TO OUR SOUTH AND DRIER AIR FILTERS INTO THE AREA.
FOG AND/OR LOW CLOUDS MAY BECOME A PROBLEM AGAIN TONIGHT AS LOW
LEVEL FLOW BECOMES NORTHEASTERLY BEHIND THE FRONTAL PASSAGE. LATER
SHIFTS WILL HAVE TO REASSESS THAT POTENTIAL.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SBH
SHORT TERM...ABE
LONG TERM...JMW
AVIATION...ABE
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1130 AM CDT WED AUG 6 2014
.UPDATE...
JUST A FEW TWEAKS TO AFTERNOON POP/WX FROM EARLIER ISSUANCE.
&&
.DISCUSSION...
THE CU FIELD IS BLOOMING ACROSS MUCH OF OUR AREA AT THIS TIME.
HOURLY READINGS ARE VERY CLOSE TO THIS TIME YESTERDAY WITH HIGHS
PRETTY MUCH RIGHT AT PERSISTENCE AGAIN TODAY WITH 00Z NAM A TAD
WARMER...BUT 12Z NUMBERS CLOSER TO FORECAST VALUES. SO NO CHANGES
THERE...BUT WE HAVE BEEFED UP THE CLOUDS A BIT WITH MANY SITES
MORE THAN EVEN SCATTERED AND PUSHING BROKEN AT LEAST RIGHT NOW. OF
COURSE AS TOWERS GO UP...AIR SINKS ALL AROUND AND PARTLY CLOUDY
WILL REMAIN QUITE SUFFICIENT FOR WORDING. NEW HRRR MODEL INDICATES
SOME QPF IN THE I-30 CORRIDOR AND IN FACT THE WATER VAPOR SHOWS A
BIT A OF PUSH ACROSS OK RIGHT NOW. SO WE HAVE ADDED SOME POPS TO
INCLUDE MUCH OF OUR CWA FOR THE AFTERNOON HOURS. NEW PRODUCTS ARE
ON THE WAY.
&&
.PREV DISCUSSION... /ISSUED 940 AM CDT WED AUG 6 2014/
AVIATION...
VFR FLIGHT CONDITIONS WILL CONTINUE THROUGH MUCH OF THE 12Z TAF
PERIOD FOR GENERALLY ALL TERMINALS IN THE ARKLATEX. AN ISOLATED
THUNDERSTORM COULD PROVIDE TEMPO INTERRUPTIONS...BUT CHANCES OF
TSRA ACTIVITY REMAINS LOW. MVFR FOG WILL BE POSSIBLE EARLY
THURSDAY MORNING AT VARIOUS SITES BETWEEN 09Z AND 13Z.
PREV DISCUSSION... /ISSUED 332 AM CDT WED AUG 6 2014/
DISCUSSION...
WV IMAGERY THIS MORNING CONTINUES TO SHOW THE UPPER RIDGE OVER THE
DESERT SW...AND A RESIDUAL UPPER TROF OVER THE ERN U.S. THIS
PATTERN IS EXPECTED TO CONTINUE THROUGH THE ENTIRE FCST PD...
BRINGING OUR FIRST PROLONGED DOSE OF SUMMER WEATHER OF THE SEASON.
THE UPSIDE TO THIS IS THAT THE ARKLATEX IS UNDER WEAK NW FLOW
ALOFT...JUST CLOSE ENOUGH THAT DISTURBANCES MOVING AROUND THE NERN
PERIPHERY OF THE RIDGE CAN ENHANCE DIURNAL CONVECTION. WE WILL SEE
A FEW OF THESE BEGINNING THURSDAY AND CONTINUING THROUGH SATURDAY...
BEFORE THE UPPER RIDGE BECOMES CENTERED OVHD MOVING INTO THE NEW
WEEK. DESPITE THE PRESENCE OF THE UPPER RIDGE...WE SHOULD CONTINUE
TO KEEP CHANCES FOR ISOLD/SCT CONVECTION FOR EARLY NEXT WORK WEEK.
THE RIDGE IS FCST TO DRIFT BACK TO THE W BY MIDWEEK AS THE EAST
COAST UPPER TROF AMPLIFIES.
TEMPERATURES ARE EXPECTED TO CONTINUE TO RUN JUST SLIGHTLY BELOW
NORMAL THROUGH THE REMAINDER OF THE WORK WEEK. HOWEVER...THEY ARE
FCST TO CREEP INTO THE MID AND UPPER 90S BY THE WEEKEND...AS THE
RIDGE REINFORCES ITSELF OVHD. IT APPEARS THAT SUMMER IS FINALLY
HERE TO STAY. /12/
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 94 75 93 75 94 / 20 10 20 20 20
MLU 94 74 93 73 94 / 20 10 20 20 20
DEQ 91 71 92 71 93 / 20 10 20 20 20
TXK 92 73 94 73 94 / 20 10 20 20 20
ELD 93 72 93 72 93 / 20 10 20 20 20
TYR 93 75 92 75 93 / 20 10 20 20 20
GGG 94 75 94 74 94 / 20 10 20 20 20
LFK 95 75 95 74 95 / 30 10 20 20 20
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
LA...NONE.
OK...NONE.
TX...NONE.
&&
$$
24
AREA FORECAST DISCUSSION
NWS CARIBOU ME
601 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WILL CONTINUE TO MOVE OFFSHORE OVERNIGHT. AN UPPER
LEVEL TROUGH OF LOW PRESSURE FROM NORTHERN QUEBEC WILL CROSS THE
REGION LATER THURSDAY INTO THURSDAY EVENING. STRONG HIGH PRESSURE
BOTH AT THE SURFACE AND HIGH ALOFT WILL GRADUALLY BUILD TOWARD THE
REGION FROM CENTRAL CANADA LATER FRIDAY THROUGH THE WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
530 PM UPDATE...EXTENDED THE MENTION OF TSTMS INTO THE EARLY
EVENING FOR THE COASTAL AREAS. 21Z MESO ANALYSIS SHOWED SB CAPES
OF 1500 JOULES ACROSS HANCOCK AND WASHINGTON COUNTIES. COLD FRONT
MAKING ITS WAY TO THE COASTAL WATERS AND A NICE CONVERGENCE ZONE
SETTING UP AIDING THE HEAVY ACTIVITY. RADAR ESTIMATES OF UP TO ONE
PER HOUR W/THE TSTMS. LAPS SOUNDINGS SUPPORT POTENTIAL FOR SOME
SMALL HAIL AS WELL AS WEAK STORM MOTION LEADING TO SLOW MOVING
STORMS. ACTIVITY IS EXPECTED TO WEAKEN AFTER 00Z AS DEPICTED BY
THE LATEST HRRR 3KM RUN WHICH IS HANDLING THE CURRENT SITUATION
QUITE WELL. FOG WILL BE A CONCERN INLAND AND HAS HUNG ON OVER THE
WATERS.
PREVIOUS DISCUSSION....NUMEROUS SHWRS AND ISOLD TO SCT TSTMS
HAVE RE-DEVELOPED MID TO LATE AFTN ACROSS DOWNEAST AND SE PTNS OF
THE FA AS PER THE HRRR REF MODEL OUTPUT. THIS SAME MODEL SHOWS
MOST AND EVENTUALLY ALL OF THIS ACTIVITY EITHER DISSIPATING OR
MOVING E OF THE FA DURING THE EVE HRS.
OTHERWISE...DRIER LLVL AIR WILL SLOWLY MOVE SWRD INTO E CNTRL PTNS
OF THE FA OVRNGT. REMAINING LLVL MOISTURE FROM CURRENT RNFL COULD
RESULT IN PATCHY FOG OVR SRN PTNS OF THE FA LATE TNGT...DESPITE
A LGT NNW SFC-BL GRAD FLOW. OVRNGT LOWS WILL DEFINITELY BE COOLER
TNGT THAN THE LAST FEW.
THU WILL START OUT FAIR...BUT A S/WV TROF MOVG SSE OUT OF NW QB
WILL BRING A POCKET OF MID LVL COLD AIR MSLY TO WRN AND SRN PTNS
OF THE FA BY THU AFTN. SUBSEQUENTLY...WE XPCT THE BEST POTENTIAL
OF SHWRS AND ISOLD TO SCT TSTMS TO THESE PTNS OF THE FA...WITH
LESSER POTENTIAL OVR THE N AND E. WE MENTION SMALL HAIL AND BRIEF
HEAVY RN ENHANCED WORDING WITH THE MENTION OF TSTMS OVR OUR FAR
SWRN ZONES WITH LIKELY POPS THU AFTN. HI TEMPS THU WILL BE
SLIGHTLY COOLER THAN TDY...SPCLY OVR WRN PTNS OF THE FA.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
A LARGE UPPER LEVEL TROUGH WILL LINGER OVER NEW ENGLAND THROUGH
THE FIRST HAVE OF THE SHORT TERM FCST PERIOD...BRINGING UNSETTLED
CONDITIONS TO OUR FCST AREA THURSDAY NIGHT THROUGH FRIDAY EVENING.
ANY PRECIP THAT DOES DEVELOP SHOULD BE MAINLY DIURNALLY
DRIVEN...WITH SHOWERS/STORMS DEVELOPING DURING THE DAY AND
DISSIPATING OVERNIGHT. THE TROUGH WILL DEPART OFF TO THE EAST
FRIDAY NIGHT AND ESPECIALLY ON SATURDAY...RESULTING IN MAINLY DRY
CONDITIONS UNDER PARTLY TO MOSTLY SUNNY SKIES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AN UPPER LEVEL RIDGE WILL BUILD OVER THE NORTHEAST DURING THE
EXTENDED FCST PERIOD...RESULTING IN MAINLY DRY CONDITIONS AND
SEASONABLY WARM TEMPERATURES. THE GFS DOES SHOW POSSIBLE DAYTIME
CONVECTION. HOWEVER NOT CONFIDENT TO ADD IT TO FORECAST ATTM. A
COLD FRONT WILL BRING A ROUND OF SHOWERS AND STORMS TO NEW ENGLAND
TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
NEAR TERM: MSLY VFR...WITH MVFR OR IFR VSBYS POSSIBLE LATE TNGT
OVR DOWNEAST SITES IN PATCHY FOG LATE TNGT OR IN ANY HEAVIER
SHWRS AT ANY TAF SITE THU AFTN.
SHORT TERM: VFR CONDITIONS SHOULD PREVAIL THURSDAY NIGHT THROUGH
SATURDAY. HOWEVER IF ANY SHOWERS AND STORMS DO DEVELOP...MVFR/IFR
CONDITIONS MAY ACCOMPANY THIS ACTIVITY.
&&
.MARINE...
NEAR TERM: SOME SWELL FROM POST TROP STM BERTHA WILL CROSS INTO
OUR WATERS FROM THE S AND SE TNGT THRU THU...BUT FOR NOW...WE DO
NOT XPCT LONG PD SWELL NOT REACH SUSTAINED 5 FT OR MORE...BUT
CANNOT RULE OUT A BRIEF PD OR TWO OF 5 TO 6 FT SWELLS OVR THE
OUTER BUOYS. DUE TO THE LONG PD NATURE OF THE SWELL...WE KEPT
CLOSE TO WW3 WV GUIDANCE FOR THE NEAR TERM THIS UPDATE. OTHERWISE...
WE KEEP THE MARINE FOG INTO THE OVRNGT...WITH VSBYS IMPROVING OVR
MOST OF THE WATERS BY DAYLIGHT THU.
SHORT TERM: WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS THURSDAY NIGHT INTO THIS WEEKEND.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT/VJN
SHORT TERM...RB
LONG TERM...RB
AVIATION...HEWITT/VJN/RB
MARINE...HEWITT/VJN/RB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
258 PM EDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT WED AUG 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE GREAT LKS BTWN STUBBORN CLOSED LO OVER QUEBEC AND MEAN UPR RDG
EXTENDING FM SCENTRAL CANADA SWD THRU THE PLAINS. A SHRTWV EMBEDDED
IN THIS NNW FLOW IS DIGGING TOWARD WRN LK SUP AND SUPPORTING A
CLUSTER OF SHOWERS OVER THE WRN LK EARLY THIS MRNG. BUT CLD TOP
TEMPS ARE TENDING TO WARM/SHOWERS WEAKEN A BIT WITH NOCTURNAL
COOLING AND AS THE PCPN AREA MOVES INTO A MORE STABLE ENVIRONMENT
OVER UPR MI REPRESENTED BY THE 00Z GRB RAOB. BEHIND THIS CLD
CLUSTER...SKIES ARE MOCLR OVER NW ONTARIO UNDER AREA OF MID LVL DRY
AIR ASSOCIATED WITH DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE
DIGGING SHRTWV AND SFC HI PRES. ANOTHER SHRTWV IS PRESENT OVER SRN
SASKATCHEWAN MOVING E THRU THE MEAN UPR RDG.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH THE
HI PRES IN NW ONTARIO FCST TO DOMINATE IN THE WAKE OF SHRTWV THAT WL
BE CROSSING THE UPR LKS THIS MRNG.
TODAY...LINGERING SHOWERS OVER WRN UPR MI AND BAND OF CLDS
ASSOCIATED WITH DIGGING SHRTWV WL CROSS UPR MI EARLY THIS MRNG.
APRCH OF SHRTWV RDG/RISING HGTS/DNVA/MID LVL DRYING IN THE WAKE OF
THIS DISTURBANCE WL CAUSE CONDITIONS TO TURN MOSUNNY WITH ONLY SOME
DIURNAL CU AS SFC HI PRES BLDS OVER UPR MI. FCST H85 TEMPS AS HI AS
14C OVER WRN UPR MI WL ALLOW MAX TEMPS TO PEAK NEAR 80 AWAY FM LK
MODERATION...WHICH WL OCCUR PRIMARILY DOWNWIND OF LK SUP UNDER
SYNOPTIC N H925 FLOW IN THE WAKE OF DEPARTING SHRTWV THAT WL
ACCENTUATE THE INLAND PENETRATION OF LK BREEZES OFF THE BIG LK. THE
00Z REGIONAL CNDN MODEL DOES GENERATE SOME ISOLD SHOWERS ALONG LK
BREEZE BNDRYS...BUT WL MAINTAIN GOING DRY FCST GIVEN THE NEGATIVE
DYNAMICS/LARGER SCALE DRYING AND ABSENCE OF QPF FM OTHER GUIDANCE.
COOLING NEAR LK MI WL BE MORE LOCALIZED. MIN AFTN RH WL DROP AS LO
AS 30-35 PCT OVER THE INTERIOR W HALF WITH DAYTIME MIXING OF
INCOMING DRIER AIR THAT WL CAUSE SFC DEWPTS TO FALL OFF INTO THE UPR
40S THIS AFTN. WINDS SHOULD BE NO HIER THAN ABOUT 10 MPH AWAY FM LK
BREEZES...ALLEVIATING FIRE WX CONCERNS. THERE COULD BE GUSTIER WINDS
BEHIND THE LK BREEZE BNDRYS OFF LK SUP...BUT THE AIR WL BE MOISTER
THERE.
TNGT...SFC HI PRES IS FCST TO MOVE OVHD UNDER BLDG UPR RDG. IN THE
PRESENCE OF PWAT FALLING TOWARD 0.5 INCH /40-50 PCT OF NORMAL/...
MOCLR SKIES AND LGT WINDS...EXPECT A HEALTHY DIURNAL TEMP DROP INTO
THE 40S OVER THE INTERIOR. WL ADD PATCHY FOG OVER THE COOLER
INTERIOR LOCATIONS FOR THE OVERNGT TIME.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 258 PM EDT WED AUG 6 2014
UPPER AIR PATTERN CONSISTS OF A RIDGE OVER THE UPPER GREAT LAKES 00Z
FRI WITH A TROUGH OVER THE NORTHERN PLAINS AND THE CENTRAL ROCKIES.
THE SHORTWAVE TROUGH MOVES INTO THE UPPER GREAT LAKES 12Z FRI WHICH
REMAINS OVER THE AREA ON FRI. SFC HIGH PRESSURE REMAINS IN CONTROL
OF THE WEATHER THROUGH SAT...SO QUIET WEATHER WILL CONTINUE THROUGH
THIS FORECAST PERIOD. PERSISTENCE WILL ALSO BE THE WAY TO GO WITH
VERY LITTLE CHANGES TAKING PLACE AND MADE VERY FEW CHANGES TO THE
GOING FORECAST FOR TEMPERATURES.
IN THE EXTENDED...GFS AND ECMWF SHOW A 500 MB RIDGE ACROSS THE
SOUTHERN U.S. WITH A BROAD TROUGH OVER THE NORTHERN PLAINS 12Z SUN.
THIS TROUGH MOVES INTO THE UPPER GREAT LAKES 12Z MON WITH A COLD
FRONT MOVING THROUGH THE AREA. THIS FRONT DROPS SOUTH OF THE AREA
12Z TUE AS RIDGING BUILDS INTO THE ROCKIES AND THEN MOVES INTO THE
PLAINS 12Z WED. THE UPPER GREAT LAKES REMAIN ON THE PERIPHERY OF THE
RIDGE. TEMPERATURES LOOK TO BE NEAR NORMAL THROUGH THE FORECAST
PERIOD AND LOOKS RELATIVELY DRY WITH VERY LITTLE MOISTURE TO WORK
WITH. SLIGHT CHANCE POPS FOR SUN NIGHT ACROSS THE WEST LOOKS
GOOD...AND THEN LOW CHANCE TO SLIGHT CHANCE POPS FOR MON THROUGH TUE
AS THE FRONT PASSES THROUGH LOOKS GOOD. DOES NOT LOOK LIKE REAL
GREAT CHANCES FOR A WIDESPREAD RAIN THIS FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 212 PM EDT WED AUG 6 2014
VFR CONDITIONS AND WINDS LESS THAN 10KTS WILL DOMINATE MUCH OF THE
PERIOD. THE MAIN CONCERN HOWEVER WILL BE THE DEVELOPMENT OF FOG
OVERNIGHT AT IWD AND SAW...GENERALLY INLAND FROM THE KEWEENAW
PENINSULA. CONFIDENCE REMAINS MODERATE TO LOW AT THIS TIME...SO WILL
KEEP 3-5MI VIS AT A MINIMUM 08-12Z THURSDAY. ANY FOG THAT DOES
DEVELOP SHOULD MIX OUT BY OR SHORTLY AFTER 12Z THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 AM EDT WED AUG 6 2014
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN INTO THE UPCOMING
WEEKEND...LEADING TO LIGHT WINDS BELOW 15 KTS THRU SAT AND NEAR CALM
WAVES. S WINDS MAY INCREASE UP TO 20 KTS ON SUN AS THE PRES GRADIENT
TIGHTENS OVER THE AREA BETWEEN THE HI PRES SHIFTING TO THE E AND AN
APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...07
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
213 PM EDT WED AUG 6 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM EDT WED AUG 6 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW NNW FLOW ALF OVER
THE GREAT LKS BTWN STUBBORN CLOSED LO OVER QUEBEC AND MEAN UPR RDG
EXTENDING FM SCENTRAL CANADA SWD THRU THE PLAINS. A SHRTWV EMBEDDED
IN THIS NNW FLOW IS DIGGING TOWARD WRN LK SUP AND SUPPORTING A
CLUSTER OF SHOWERS OVER THE WRN LK EARLY THIS MRNG. BUT CLD TOP
TEMPS ARE TENDING TO WARM/SHOWERS WEAKEN A BIT WITH NOCTURNAL
COOLING AND AS THE PCPN AREA MOVES INTO A MORE STABLE ENVIRONMENT
OVER UPR MI REPRESENTED BY THE 00Z GRB RAOB. BEHIND THIS CLD
CLUSTER...SKIES ARE MOCLR OVER NW ONTARIO UNDER AREA OF MID LVL DRY
AIR ASSOCIATED WITH DNVA/DEEP LYR QVECTOR DVGC IN THE WAKE OF THE
DIGGING SHRTWV AND SFC HI PRES. ANOTHER SHRTWV IS PRESENT OVER SRN
SASKATCHEWAN MOVING E THRU THE MEAN UPR RDG.
MAIN FCST CONCERNS IN THE SHORT TERM ARE FOCUSED ON TEMPS WITH THE
HI PRES IN NW ONTARIO FCST TO DOMINATE IN THE WAKE OF SHRTWV THAT WL
BE CROSSING THE UPR LKS THIS MRNG.
TODAY...LINGERING SHOWERS OVER WRN UPR MI AND BAND OF CLDS
ASSOCIATED WITH DIGGING SHRTWV WL CROSS UPR MI EARLY THIS MRNG.
APRCH OF SHRTWV RDG/RISING HGTS/DNVA/MID LVL DRYING IN THE WAKE OF
THIS DISTURBANCE WL CAUSE CONDITIONS TO TURN MOSUNNY WITH ONLY SOME
DIURNAL CU AS SFC HI PRES BLDS OVER UPR MI. FCST H85 TEMPS AS HI AS
14C OVER WRN UPR MI WL ALLOW MAX TEMPS TO PEAK NEAR 80 AWAY FM LK
MODERATION...WHICH WL OCCUR PRIMARILY DOWNWIND OF LK SUP UNDER
SYNOPTIC N H925 FLOW IN THE WAKE OF DEPARTING SHRTWV THAT WL
ACCENTUATE THE INLAND PENETRATION OF LK BREEZES OFF THE BIG LK. THE
00Z REGIONAL CNDN MODEL DOES GENERATE SOME ISOLD SHOWERS ALONG LK
BREEZE BNDRYS...BUT WL MAINTAIN GOING DRY FCST GIVEN THE NEGATIVE
DYNAMICS/LARGER SCALE DRYING AND ABSENCE OF QPF FM OTHER GUIDANCE.
COOLING NEAR LK MI WL BE MORE LOCALIZED. MIN AFTN RH WL DROP AS LO
AS 30-35 PCT OVER THE INTERIOR W HALF WITH DAYTIME MIXING OF
INCOMING DRIER AIR THAT WL CAUSE SFC DEWPTS TO FALL OFF INTO THE UPR
40S THIS AFTN. WINDS SHOULD BE NO HIER THAN ABOUT 10 MPH AWAY FM LK
BREEZES...ALLEVIATING FIRE WX CONCERNS. THERE COULD BE GUSTIER WINDS
BEHIND THE LK BREEZE BNDRYS OFF LK SUP...BUT THE AIR WL BE MOISTER
THERE.
TNGT...SFC HI PRES IS FCST TO MOVE OVHD UNDER BLDG UPR RDG. IN THE
PRESENCE OF PWAT FALLING TOWARD 0.5 INCH /40-50 PCT OF NORMAL/...
MOCLR SKIES AND LGT WINDS...EXPECT A HEALTHY DIURNAL TEMP DROP INTO
THE 40S OVER THE INTERIOR. WL ADD PATCHY FOG OVER THE COOLER
INTERIOR LOCATIONS FOR THE OVERNGT TIME.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 339 AM EDT WED AUG 6 2014
THURSDAY THROUGH SATURDAY...BROAD SURFACE RIDGING ALONG WITH UPPER
LEVEL 500MB RIDGING WILL BE IN PLACE ACROSS MUCH OF THE UPPER GREAT
LAKES REGION THROUGH THIS TIME FRAME. DRY WEATHER WILL BE THE RULE
UNDER THE RIDGE AS MOISTURE ADVECTION WILL BE LIMITED WITH VERY LOW
DEEP LAYER 1000-500MB RH VALUES. THE SURFACE HIGH WILL REMAIN
DIRECTLY OVERHEAD THROUGH FRIDAY BEFORE SLOWLY SHIFTING TO THE EAST
DURING THE DAY SATURDAY. THIS WILL KEEP LIGHT WINDS IN THE FORECAST
WITH THE STRONGEST GUSTS ASSOCIATED WITH LAKE BREEZE DEVELOPMENT
DURING THE AFTERNOON HOURS. AS PREVIOUS SHIFT MENTIONED...MOST AREAS
OF THE CWA HAVE SEEN LITTLE TO NO PRECIPITATION OVER THE PAST COUPLE
WEEKS WHICH MEANS SOIL AND VEGETATION ARE BEGINNING TO GET FAIRLY
DRY. DECENT MIXING CONDITIONS ARE EXPECTED TO OCCUR EACH AFTERNOON
THROUGH THIS TIME PERIOD...WHICH WILL LEAD TO INCREASED FIRE
DANGER...FORTUNATELY...WINDS WILL BE GENERALLY LIGHT AS PREVIOUSLY
MENTIONED. HAVE CONTINUED THE TREND OF LOWERING AFTERNOON DEWPOINTS
AS SOME OF THE DRIER AIR ALOFT MIXES DOWN TO THE SURFACE WITH
AFTERNOON HEATING. TEMPERATURES WILL BE CONTINUE TO WARM THROUGH
THIS PERIOD WITH 850MB TEMPS WARMING FROM 12C THURSDAY AFTERNOON TO
AROUND 14C BY SATURDAY AFTERNOON AS THE HIGH TREKS SLOWLY EASTWARD.
SATURDAY NIGHT THROUGH THE REMAINING EXTENDED...THE NEXT UPPER LEVEL
TROUGH AND DEVELOPING SURFACE LOW ARE PROGGED TO BE NEAR THE
SASKATCHEWAN/MANITOBA BORDER SATURDAY NIGHT WITH A COLD FRONT
STRETCHING SOUTHWESTWARD ACROSS THE DAKOTAS AS SHOWN BY ANALYZING
850 THETA E ALONG WITH SURFACE WINDS. THIS WILL BE THE MAIN FOCUS
FOR SHOWER AND THUNDERSTORM ACTIVITY. THE LOW WILL SHIFT EASTWARD TO
NORTHERN QUEBEC BY MONDAY AFTERNOON AS THE FRONT DRAPES ACROSS THE
UPPER GREAT LAKES. AT THIS POINT HAVE KEPT CHANCE POPS IN THE
FORECAST PEGGED MAINLY TO THE FRONT...DID NOT INCREASE TO LIKELY
POPS DUE TO CONTINUED TIMING ISSUES. RIGHT NOW THE BEST CHANCE OF
SHOWER AND THUNDERSTORM ACTIVITY WOULD BE DURING THE LATE SUNDAY
NIGHT THROUGH MONDAY TIME FRAME...WHICH WILL ALSO BE AROUND THE SAME
TIME THAT THE UPPER LEVEL 500MB TROUGH AXIS SWINGS ACROSS THE AREA.
THE FRONT IS PROGGED TO BE EAST OF THE AREA BY
TUESDAY...HOWEVER...WITH UPPER LEVEL TROUGHING AND LINGERING
MOISTURE NEARBY...WOULD EXPECT SHOWERS TO LINGER THROUGH THE DAY
TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 212 PM EDT WED AUG 6 2014
VFR CONDITIONS AND WINDS LESS THAN 10KTS WILL DOMINATE MUCH OF THE
PERIOD. THE MAIN CONCERN HOWEVER WILL BE THE DEVELOPMENT OF FOG
OVERNIGHT AT IWD AND SAW...GENERALLY INLAND FROM THE KEWEENAW
PENINSULA. CONFIDENCE REMAINS MODERATE TO LOW AT THIS TIME...SO WILL
KEEP 3-5MI VIS AT A MINIMUM 08-12Z THURSDAY. ANY FOG THAT DOES
DEVELOP SHOULD MIX OUT BY OR SHORTLY AFTER 12Z THURSDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 339 AM EDT WED AUG 6 2014
HIGH PRESSURE WILL DOMINATE THE WEATHER PATTERN INTO THE UPCOMING
WEEKEND...LEADING TO LIGHT WINDS BELOW 15 KTS THRU SAT AND NEAR CALM
WAVES. S WINDS MAY INCREASE UP TO 20 KTS ON SUN AS THE PRES GRADIENT
TIGHTENS OVER THE AREA BETWEEN THE HI PRES SHIFTING TO THE E AND AN
APPROACHING COLD FRONT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...KEC
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1221 PM CDT WED AUG 6 2014
.UPDATE...
ISSUED AT 1005 AM CDT WED AUG 6 2014
A FEW MINOR UPDATES TO THE SHORT TERM FORECAST...MAINLY TO ACCOUNT
FOR SLIGHTLY COOLER TEMPERATURES ACROSS OUR NORTH AND GREATER
COVERAGE OF OVC SKIES. THE UPDATES WERE TRENDED TOWARD THE LATEST
RAP AND HRRR GUIDANCE WHICH CONTINUES TO INDICATE THE PRESENCE OF
DEEP MOISTURE OVER MUCH OF THE FORECAST AREA. THE GOING FORECAST
WILL KEEP OVC SKIES ACROSS OUR NORTHERN AND CENTRAL ZONES THROUGH
MUCH OF THE DAY...SOMEWHAT MITIGATING THE EFFECTS SOLAR INSOLATION
ON THE LOWER TROPOSPHERE/EARTH SFC. OTHERWISE PRECIPITATION
FORECAST REMAINS SOMEWHAT NEBULOUS GOING INTO THE AFTERNOON
HOURS...MODELS ARE SUGGESTING QUASI- ZONAL FLOW ALOFT WILL
DIRECT ANOTHER WEAK DISTURBANCE ACROSS THE REGION...WHICH MAY SERVE AS A
FORCING MECHANISM FOR ADDITIONAL STORM DEVELOPMENT. IF STORMS ARE
REALIZED ONCE AGAIN THIS AFTERNOON...PWATS ACROSS NORTH CENTRAL
NEBRASKA AND MUCH OF THE SANDHILLS ARE DRYING SLIGHTLY...BUT STILL
ARE EXPECTED TO REMAIN TWO SD ABOVE THE MEAN...AND GIVEN
IMPRESSIVE WARM CLOUD DEPTHS OF GREATER THAN 11-12K FEET...HEAVY
RAINFALL IS POSSIBLE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 358 AM CDT WED AUG 6 2014
TODAY AND TONIGHT...MIDLEVEL FRONTOGENESIS IN THE MODELS HAS
VANISHED LEAVING FOR SOMEWHAT NEBULOUS DYNAMICAL FORCING TODAY
AND TONIGHT. THIS IS OCCURRING AS A RESULT OF HEIGHT RISES
ASSOCIATED WITH A DEPARTING UPPER LOW ACROSS THE CANADIAN
MARITIMES. THERE ARE ALSO INDICATIONS OF DRYING IN THE MID AND
UPPER LEVELS OF THE ATMOSPHERE ALSO. PRECIPITABLE WATER FALLS
BELOW 1.5 INCHES IN MANY AREAS.
WATER VAPOR SHOWS ANOTHER DISTURBANCE ACROSS NORTHWESTERN
COLORADO THIS MORNING AND A SECOND WEAKER DISTURBANCE ACROSS
NORTH CENTRAL COLORADO AND SOUTHEASTERN WYOMING. BOTH COULD SERVE
AS FORCING MECHANISMS FOR TSTM DEVELOPMENT. THE NAM AND OTHER
MODELS SHOW POCKETS OF K INDICES AROUND 40C THIS AFTN...MAINLY
ACROSS WESTERN NEBRASKA. THIS MOISTURE IS POOLING BEHIND THE SFC
LOW PRESSURE SYSTEM ACROSS CNTL NEB. GIVEN THE PROXIMITY OF THESE
DISTURBANCES IT WOULD APPEAR THE BETTER CHANCES OF RAIN WOULD
OCCUR FROM NOON THROUGH EARLY EVENING.
THUS THE MODELS SHOW DISORGANIZED AREAS OF SHOWERS AND
THUNDERSTORMS TODAY WHICH BECOME ISOLATED TONIGHT. THIS IS LIKELY
THE RESULT OF THE LACK OF FOCUS IN THE LOWER LEVELS OF THE
ATMOSPHERE. THE FORECAST CALLS OF ISOLATED TO SCATTERED SHOWER
AND THUNDERSTORM ACTIVITY...MAINLY THIS AFTERNOON WHICH BECOMES
ISOLATED TONIGHT. MODEL BLENDED QPF AND POPS FEATURE THE BEST
CHANCES ACROSS THE NCNTL ZONES EAST OF VALENTINE INCLUDING CUSTER
COUNTY. THIS FORECAST USES 50 PERCENT OF THE
ECM...GFS...NAM...GEM AND SREF AND 50 PERCENT OF THE RAP MODEL
HAS PERFORMED FAIRLY WELL.
COOLER AIR WILL FILLS IN BEHIND THE SFC LOW AS IT MIGRATES SOUTH
AND EAST INTO KANSAS AND SOUTHEAST NEBRASKA. THIS SHOULD KEEP
HIGHS IN THE UPPER 70S TO UPPER 80S TODAY WITH HIGH HUMIDITY ONCE
AGAIN.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 358 AM CDT WED AUG 6 2014
LITTLE CHANGE FOR THURSDAY AS UPPER RIDGE LOCATES ACROSS THE
SOUTHERN ROCKIES INTO THE SOUTHERN PLAINS. RIDGE RIDERS TO CROSS
THE CENTRAL ROCKIES AND ONTO THE HIGH PLAINS. MODELS IN GOOD
AGREEMENT BRINGING A DISTURBANCE ACROSS THE AREA LATE THURSDAY.
MODELS DROP PWATS EARLY...HOWEVER AN INCREASE IS EXPECTED TO
GREATER THAN 2 SD BY LATE AFTERNOON. MODELS ARE CURRENTLY
FAVORING SW NEB AND WILL RETAIN HIGHEST POPS...LIKELY...THERE.
MODELS CONTINUE TO AGREE BRINGING ADDITIONAL WAVES ACROSS THE
AREA INTO THE WEEKEND. RAIN CHANCES WILL REMAIN
POSSIBLE...HOWEVER COVERAGE STILL IN QUESTION. TEMPS ARE A LITTLE
TRICKY AS THE RIDGE CONTINUES TO FLATTEN...AND CLOUD COVER WILL
BE KEY TO AFTERNOON PEAKS. GENERALLY EXPECT HIGHS AT OR BELOW
SEASONAL NORMS...WHICH IS IN THE MID AND UPPER 80S.
AS WE GO INTO NEXT WEEK MODELS DIVERGE. THE GFS BEGINS TO REBUILD
THE RIDGE IN THE WEST...WHILE THE ECMWF KEEPS THE RIDGE
FLATTENED. THE GFS WOULD FAVOR A WARMER FORECAST COMPARED TO THE
EC...HOWEVER AS THE RIDGE BUILDS...PER GFS SOLUTION...NORTHWEST
FLOW WOULD CONTINUE TO BRING DISTURBANCES ACROSS THE AREA. THUS
WILL KEEP THE BLENDED FORECAST AS WILL STILL HAVE AT LEAST
PERIODIC LOW CHANCES FOR RAIN. LESS CERTAINTY FOR TEMPS AND WILL
KEEP BLENDED GUIDANCE AND MONITOR TO SEE HOW MODELS CHANGE OVER
THE COMING DAYS TO MAKE ADJUSTMENTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1230 PM CDT WED AUG 6 2014
DEGREE OF CLOUD DEVELOPMENT/EROSION A CHALLENGE THIS AFTERNOON.
SHORT TERM MODELS POINT TO BOUNDARY LAYER MOISTURE DECREASING THIS
AFTERNOON...ATHOUGH THE SATELLITE LOOP DOESN/T PROVIDE MUCH
CONFIDENCE AT THIS TIME AS STRATUS DECK HAS SPREAD SOUTH TO NEAR
INTERSTATE 80 TO INCLUDE THE KLBF TERMINAL. GOING FORWARD THE
STRATUS LAYER MAY LIFT A FEW MORE HUNDRED FEET AT THE KVTN
TERMINAL FOR MVFR CONDITIONS INTO THE EVENING THEN DROPPING TO
IFR/MVFR CONDITIONS OVERNIGHT THROUGH 15Z THURSDAY. THE STRATUS
(MVFR CONDITIONS) MAY INPACT THE KLBF TERMINAL THE NEXT COUPLE OF
HOURS...THEN LIFT UNTIL THIS EVENING. BEYOND THE STRATUS WILL
DEVELOP FURTHER SOUTH OVERNIGHT WITH MVFR CONDITIONS TO EXTEND
ACROSS THE KLBF TERMINAL AS WELL.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...JACOBS
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...KECK
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
335 PM EDT WED AUG 6 2014
.SYNOPSIS...
A SERIES OF UPPER DISTURBANCES WILL MOVE ACROSS THE NORTH
COUNTRY THROUGH THURSDAY. THE FIRST WILL BE MOVING ACROSS THE
REGION LATE TONIGHT PRODUCING CLOUDS AND CHANCES FOR A FEW SHOWERS
ACROSS NORTHERN NEW YORK TONIGHT. A STRONGER UPPER DISTURBANCE
WILL MOVE ACROSS THE NORTH COUNTRY THURSDAY. A GREATER COVERAGE
OF SHOWERS AND A FEW THUNDERSTORMS IS EXPECTED THURSDAY
AFTERNOON...SOME OF WHICH COULD PRODUCE SMALL HAIL. A LARGE
REGION OF HIGH THEN BUILDS ACROSS THE NORTH COUNTRY FRIDAY INTO
THE WEEKEND WITH A STRETCH OF DRY...PLEASANT WEATHER. HIGH
TEMPERATURES WILL BE IN THE 70S THURSDAY AND FRIDAY...CLIMBING
BACK INTO THE LOW TO MID 80S ON SATURDAY AND SUNDAY.
&&
.NEAR TERM /UNTIL 7 AM THURSDAY MORNING/...
AS OF 335 PM EDT WEDNESDAY...A GENERALLY PLEASANT AFTN ACROSS THE
NORTH COUNTRY WITH MOSTLY SUNNY TO PARTLY CLOUDY
SKIES...COMFORTABLE DEWPOINTS FALLING INTO THE 50S AND A NORTHERLY
BREEZE IN PLACE. HOWEVER...A BROAD LONGWAVE TROUGH IS ESTABLISHING
ITSELF ACROSS MUCH OF NORTHEASTERN NOAM...AND THE FIRST OF A
SERIES OF WEAK VORT MAXIMA WILL APPROACH THE NORTH COUNTRY BY
LATER TONIGHT. THIS INITIAL SHORTWAVE TROUGH/ASSOCIATED VORT MAX
IS NOW PRODUCING A SHIELD OF ENHANCED CLOUDINESS OVER THE OTTAWA
VALLEY...THOSE CLOUDS MOST APPARENT IN 12Z BTV-4/15Z RAP AS A
RIBBON OF 850-700MB RH. SOME MODEST PROGGED VERTICAL MOTION IN
THAT LAYER AS WELL. SO EXPECT AN INCREASE IN CLOUDS WITH CHANCES
FOR LIGHT SHOWERS - WITH THE BEST CHANCE OF SHOWERS AFTER MIDNIGHT
AND PRIMARILY CONFINED TO NORTHERN NEW YORK. LITTLE IN THE WAY OF
QPF WITH THE SHOWERS...A FEW HUNDRETHS OF AN INCH. SKIES WILL TEND
TO BE CLEAREST ACROSS EASTERN VT/CT RIVER VALLEY WHICH WILL ALLOW
FOR RIVER VALLEY FOG TO DEVELOP ACROSS THIS GENERAL AREA
OVERNIGHT.
TEMPS WILL LIKELY DROP OFF QUICKLY EARLY THIS EVENING UNDER DRY
CONDITIONS...BUT COOLING WILL TEND TO LEVEL OFF A BIT ACROSS THE
NORTHERN HALF OF THE CWA. I OPTED TO TREND TEMPS CLOSER TO WARMER
SIDE OF AVAILABLE GUIDANCE GIVEN EXPECTED CLOUDINESS...GENERALLY IN
THE 40S TO MID/UPPER 50S IN THE VALLEYS. LOWS GENERALLY COOLEST IN
THE `DACKS AND ACROSS EASTERN VERMONT.
&&
.SHORT TERM /7 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
AS OF 335 PM EDT WEDNESDAY...MORE UNSETTLED CONDITIONS ARE THEN
EXPECTED FOR THURSDAY. A STRONGER VORT MAX COMBINED WITH COOL
TEMPS ALOFT WILL FURTHER ENHANCE CLOUDINESS AND PRODUCE SHOWERS
AND A FEW THUNDERSTORMS. INSTABILITY AS PROGGED BY 12Z NAM
GENERALLY BETWEEN 500 TO UNDER 1000 J/KG...KEPT DOWN BY DRY
DEWPOINTS IN THE 50S. SFC HEATING WILL ALSO TEND TO LOWER AS THE
DAY GOES ON AS WELL AS HEATING SHOULD READILY PRODUCE CUMULUS
CLOUDS GIVEN THE COOL TEMPS ALOFT. THEREFORE FEEL THREAT FOR
THUNDER WOULD BE MORE OF A SLIGHT CHANCE...BUT ANY ENHANCED
UPDRAFTS COULD PRODUCE GRAUPEL OR SMALL SUB-SEVERE HAIL GIVEN
PRESENCE OF LOW WET BULB ZERO HEIGHTS /7-9 KFT/. HI-RES
REFLECTIVITY GUIDANCE SHOWS CELLULAR ACTIVITY...WHICH MAKES SENSE
AS THERE ISN`T MUCH FORCING TO SUPPORT OTHER CONVECTIVE MODES.
DEEP LAYER SHEAR ALSO IS LOW. NO ENHANCED WORDING ADDED TO THE
GRIDS AT THIS TIME BUT WILL MENTION IN THE HWO POTENTIAL FOR A FEW
NON-SEVERE T-STORMS CAPABLE OF SUB-SEVERE HAIL. POPS TREND UPWARD
THROUGH THE AFTN TO HIGH CHANCE/LIKELY WHEN BEST SYNOPTIC LIFT
ASSOCIATED WITH THE SHORTWAVE AND DIURNAL HEATING OVERLAP...BEFORE
LOWERING BY EVENING. QPF AMOUNTS ARE GENERALLY UNDER .25" THROUGH
THE DAYLIGHT HOURS THURSDAY. COOLER HIGHS FOR THURSDAY WITH MOSTLY
CLOUDY SKIES AND 850 TEMPS OF +7 TO +9C...IN THE UPPER 60S TO MID
70S...COOLEST IN EASTERN VT AND MILDER ACROSS THE ST. LAWRENCE
VALLEY. CLEARING SKIES AND LIGHT SFC TO BL WINDS THURSDAY NIGHT
WILL ALLOW FOR OVERNIGHT RIVER VALLEY FOG IN THE FAVORED VALLEYS.
ASIDE FROM SLIGHT CHANCES FOR A FEW DIURNAL SHOWERS ACROSS THE
NORTHEAST KINGDOM AREA...EXPECT FRIDAY TO BE A MOSTLY CLEAR TO
PARTLY CLOUDY DAY WITH AFTN FAIR WX CUMULUS CLOUDS. 850 TEMPS WARM
UP TO AROUND +10 TO +11C...WHICH SHOULD YIELD HIGHS IN THE 70S TO
A FEW SPOT 80 DEGREE READINGS. ANOTHER GOOD RADIATIONAL COOLING
NIGHT ANTICIPATED FRIDAY NIGHT WITH OVERNIGHT RIVER VALLEY FOG
ONCE AGAIN DEVELOPING IN THE FAVORED VALLEYS...WITH LOWS RANGING
IN THE MID 40S TO MID/UPPER 50S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 314 PM EDT WEDNESDAY...PRETTY QUIET WEATHER IS EXPECTED
THROUGH THE LONG TERM PERIOD AS EXITING LOW PRESSURE OVER THE
CANADIAN MARITIMES FRIDAY NIGHT IS REPLACED BY UPPER LEVEL
RIDGING AND SURFACE HIGH PRESSURE SATURDAY WHICH WILL BRING DRY
WEATHER FOR THE WEEKEND AND THROUGH MONDAY NIGHT. TEMPS WILL RUN
PRETTY CLOSE TO CLIMO UNDER FULL SUNSHINE DURING THE DAY AND
CLEAR SKIES AT NIGHT WITH EXPECTED HIGHS RANGING FROM THE MID 70S
TO MID 80S...AND LOWS IN THE LOWER 50S TO LOWER 60S.
CHANCES FOR PRECIPITATION INCREASE TUESDAY AS AN UPPER LEVEL
TROUGH DIGS SOUTHWARD FROM CENTRAL CANADA INTO NEW ENGLAND
DRAGGING A WEAK COLD FRONT THROUGH THE FORECAST AREA. GFS AND
ECMWF ARE IN BETTER AGREEMENT TODAY ON TIMING WHICH WILL PLAY A
LARGE ROLE IN THE POTENTIAL FOR THUNDERSTORM DEVELOPMENT. CURRENT
PROGS ARE POINTING TOWARDS AN EVENING AND OVERNIGHT FROPA...BUT
THIS FAR OUT IT`S TOO DIFFICULT TO PINPOINT. WILL CONTINUE TO
HIGHLIGHT CHANCE POPS.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
THROUGH 18Z THURSDAY...VFR CONDITIONS EXPECTED THROUGH THE NEXT 24
HOURS. SCATTERED TO BROKEN LOW/MID LEVEL CLOUDS ACROSS THE
ADIRONDACKS AND VERMONT WILL DISSIPATE LATE THIS AFTERNOON INTO
THE EVENING HOURS BEFORE ANOTHER ROUND MID LEVEL CLOUDS SPREADS
OVER THE REGION OVERNIGHT. COULD SEE A FEW SHOWERS ASSOCIATED
WITH THIS CLOUD COVER MOVING IN ACROSS NORTHERN NEW YORK
OVERNIGHT...BUT OVERALL BETTER CHANCES FOR SHOWERS AND STORMS
COMES LATER THURSDAY AFTERNOON FROM KSLK EASTWARD.
OUTLOOK 18Z THURSDAY THROUGH MONDAY...
18Z THU - 12Z FRI...PREDOMINANTLY VFR WITH SCATTERED SHOWERS AND
ISOLATED THUNDERSTORMS THURSDAY AFTERNOON AND EVENING BRIEFLY
LOWERING CONDITIONS TO MVFR AND IFR. POTENTIAL FOR IFR/LIFR
FOG/BR DEVELOPMENT THURSDAY NIGHT AS WELL...ESPECIALLY AT KSLK AND
KMPV.
12Z FRI - 00Z TUE...VFR UNDER HIGH PRESSURE. EARLY MORNING IFR FOG/BR
POSSIBLE EACH NIGHT...ESPECIALLY AT KSLK AND KMPV.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...LOCONTO
NEAR TERM...LOCONTO
SHORT TERM...LOCONTO
LONG TERM...LAHIFF
AVIATION...LAHIFF
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
113 PM EDT WED AUG 6 2014
.SYNOPSIS...
A TROUGH OF LOW PRESSURE WILL GIVE WAY TO A COLD FRONT EARLY
THURSDAY MORNING. THIS FRONT WILL STALL JUST SOUTH OF THE AREA ON
FRIDAY. THIS FRONT WILL SLOWLY SHIFT NORTHWARD OVER THE AREA
THIS WEEKEND INTO EARLY NEXT WEEK WHICH WILL BRING AN INCREASED
CHANCE OF THUNDERSTORMS EACH DAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 113 PM WEDNESDAY...A WIDESPREAD CUMULUS FIELD HAS DEVELOPED
IN THE PAST SEVERAL HOURS AND THE KEYS ON THE AREA OF THE DEEPER
MOISTURE WHICH IS GENERALLY NORTH OF A FLORENCE TO MYRTLE BEACH
LINE. A FEW SHOWERS ARE DEVELOPING JUST NORTH OF BLADEN COUNTY.
THIS FITS WELL WITH THE 13 UTC RUN OF THE HRRR REFLECTIVITY FIELD
WHICH INDICATES ISOLATED CONVECTION WILL FORM IN THAT AREA AND RUN
ALONG AN AXIS FROM BLADEN COUNTY THROUGH DARLINGTON COUNTY UNTIL 23
UTC. ALSO...ISOLATED THUNDERSTORMS ARE EXPECTED TP DEVELOP ALONG THE
SEA BREEZE MAINLY FROM MYRTLE BEACH NORTHWARD.
OVERNIGHT A COLD FRONT WILL SHIFT FROM THE NORTHWEST AND WILL MOVE
INTO THE NORTHWEST PORTION OF THE COUNTY WARNING AREA AROUND
SUNRISE. LOW TEMPERATURES ARE EXPECTED TO REMAIN IN THE LOWER 70S
EXCEPT FOR MID 70S AT THE IMMEDIATE COAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PIEDMONT TROUGH GETS PUSHES TO THE COAST
EARLY THURSDAY BY INCREASINGLY DEEP LAYER NWRLY FLOW AROUND DEEP
UPPER FEATURE NORTH OF MAINE. AS THE DAY WEARS ON IT IS DRAWN BACK
SLIGHTLY INLAND AS A PASSING UPPER SHORTWAVE YIELDS GENTLE PRESSURE
FALLS OVER LAND. ISOLATED CONVECTION THUS SEEMS POSSIBLE...AND GIVEN
THE POSITION OF THE BOUNDARY AND THE EXPECTED STORM MOTION THE POPS
WILL BE GRADED FROM WEST TO EAST. BY LATE EVENING A COLD FRONT
ENTERS NORTHWESTERN ZONES...BUT THERE IS STILL SOME NVA GOING ON IN
THE MID LEVELS FROM THE EXITING AFTERNOON SHORTWAVE...POPS MAY TREND
DOWNWARD FOR A BIT BUT WILL HOLD ON TO CHANCE WORDING FEATURED IN
PREV FORECAST. BY 06Z FRIDAY THE FRONT IS ALREADY SOUTH OF THE AREA
AND WE SHOULD STAY DRY. RAIN CHANCES THEN RETURN OVER SOUTHERN ZONES
FRIDAY MORNING AS THE FRONT BEGINS TO WASH BACK NORTHWARD AND THEN
THERE IS A SHIFT TO THE FAR WESTERN ZONES AS A WEAK VORT CENTER
INTERACTS WITH WHAT MAY BE SOME ELEVATED INSTABILITY. AS SOME VERY
LIGHT SOUTHERLY FLOW DEVELOPS ATOP THE SURFACE WEDGE FRIDAY NIGHT
SOME ELEVATED CONVECTION MAY PERSIST...AGAIN FAVORING WESTERN
ZONES.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY...DEPENDING ON MODEL OF CHOICE THE WEEKEND IS
NOW SHAPING UP TO BE ANYWHERE FROM QUITE UNSETTLED TO JUST ABOUT A
COMPLETE WASHOUT. FRONTAL BOUNDARY STALLED JUST SOUTH OF THE AREA
SATURDAY THROUGH SUNDAY WITH FLAT RIPPLES OF SURFACE AND LOW
PRESSURE MOVING ALONG IT TO PRODUCE LITTLE BURSTS OF ISENTROPIC
UPGLIDE. NOT TO SAY THAT RAIN WILL EVER BE OVERLY HEAVY BUT THERE IS
LITTLE TO NO TIME OVER THE WEEKEND THAT RAIN DOES NOT APPEAR TO
WARRANT BEING SOLIDLY IN THE FORECAST. DAYTIME HIGHS OBVIOUSLY HELD
BELOW CLIMO WHILE NIGHTTIME LOWS NEAR OR SLIGHTLY ABOVE SEASONAL
NORMS WITH ALL OF THE CLOUDINESS. MODELS DIVERGE EARLY NEXT WEEK
WITH SOME SHOWING CONTINUED WEDGING (SEEMINGLY PROBABLE) WHILE
OTHERS SHOW LOW PRESSURE DEVELOPING LOW PRESSURE UP AND DOWN THE
COAST MAKING FOR WIDESPREAD SHOWER/TSTM COVERAGE WHILE THE BOUNDARY
BECOMES POORLY DEFINED. LUCKILY THE END RESULT MAY BE THE SAME
LOCALLY WITH A CONTINUATION OF INHIBITED AFTERNOON HIGHS ALONG WITH
HIGHER THAN NORMAL RAIN CHANCES.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
A WEAK PIEDMONT TROUGH IS EXPECTED THIS AFTERNOON. ISOLATED
CONVECTION IS EXPECTED ALONG THE SEA BREEZE BOUNDARY AND NORTHEAST
OF A KFLO TO KEYF LINE . A DIRECT HIT AT THE COAST TERMINALS IS
RATHER UNLIKELY...WITH JUST A VCSH MENTION. WESTERLY WINDS INLAND
WITH SOUTHERLY WINDS EXPECTED EAST OF THE RESULTANT. LIGHT WINDS
TONIGHT WITH MVFR FOG A COUPLE OF HOURS BEFORE SUNRISE.
THURSDAY...PREDOMINATELY VFR WITH MAINLY A LIGHT NORTHWEST WIND.
EXTENDED OUTLOOK...ISOLATED SHOWERS/TSTMS POSSIBLE THURSDAY AND
FRIDAY. INCREASING CHANCES FOR SHOWERS/MVFR THIS WEEKEND THROUGH
MONDAY AS A STALLED FRONT LINGERS OVER THE CAROLINAS.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 113 PM WEDNESDAY...THE SEA BREEZE IS DEVELOPING NEARSHORE
AND THE WEST WINDS ARE SHIFTING FROM THE WEST TO THE SOUTH-
SOUTHEAST AT 5 TO 10 KNOTS. AT 1610 UTC...THE MASONBORO INLET
BUOY...41110...WAS DETECTING A 2.6 FOOT SWELL WITH A 8.3 SECOND
PERIOD FROM THE WAKE OF THE FORMER TROPICAL STORM BERTHA. MODELS
ARE SHOWING THIS SWELL CONTINUING THROUGH OUT THIS AFTERNOON AND
SLOWLY WEAKENING BY THIS EVENING.
A WEAK FRONT FROM THE NORTH WILL APPROACH THE AREA BY SUNRISE AND
THIS WILL TRANSLATE INTO SOUTHWEST WINDS ACROSS THE WATER
OVERNIGHT AS THE SEABREEZE CIRUCLATION DISSIPATES AFTER SUNSET.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/... AS OF 3 AM
WEDNESDAY...THURSDAY WILL BRING A SOUTHWESTERLY FLOW AHEAD OF
PIEDMONT TROUGH AND APPROACHING COLD FRONT. THE TROUGH WILL BE
QUITE CLOSE TO THE COAST...MORE SO THAN NORMAL...KEEPING THE WINDS
VERY LIGHT. WITH NO LINGERING BERTHA SWELLS SEAS SHOULD BE CAPPED
AT 2 TO 3 FT. WIND SWINGS AROUND TO NE AND AS A COLD FRONT PUSHES
THROUGH LATE THURSDAY NIGHT. AS USUAL WITH FRONTS THIS TIME OF
YEAR THERE WILL BE NO BIG SURGE OF HIGHER WIND OR PRESSURE. SO
OTHER THAN A SLIGHT SHORTENING OF THE DOMINANT PERIOD FROM THE
WIND SHIFT THERE WILL NOT BE AN APPRECIABLE CHANGE IN SEAS
FOLLOWING FROPA.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY...FRONTAL BOUNDARY TO LINGER AND MEANDER JUST
SOUTH OF THE REGION OVER THE WEEKEND. THIS WILL KEEP THE WIND OUT OF
THE EAST FOR THE MOST PART. WIND SPEED UNCERTAINTY BY ABOUT A
CATEGORY OR SO MUCH MUCH OF THE PERIOD HINGING ON THE STRENGTH OF
THE HIGH THAT WILL SIT NORTH OF THE BOUNDARY AS WELL AS SOME FLAT
WAVES OF LOW PRESSURE THAT MAY RIPPLE ALONG ITS LENGTH. OVERALL
THOUGH NOT EXPECTING ANY ADVISORIES OR EVEN CAUTIONARY HEADLINES.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HAWKINS
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS TULSA OK
1249 PM CDT WED AUG 6 2014
.DISCUSSION...
THE 18Z AVIATION DISCUSSION IS INCLUDED BELOW...
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
THE MAIN FORECAST CONCERN WILL BE TSRA CHANCES THIS PERIOD. IT
APPEARS BASED ON WHERE THE SFC BOUNDARY AND UPPER WAVE IS LOCATED
THAT THE BEST CHANCE OF CONVECTION WILL BE NORTH OF THE KS
BORDER...WHERE A CLUSTER OF STORMS IS EXPECTED TO FORM AND MOVE
EAST. HOWEVER...THERE IS ENUF UNCERTAINTY IN HOW FAR SOUTH THIS
WILL BE LOCATED TO INCLUDE VCTS AND PROB30 MENTIONS IN THE NE OK
AND NW AR TAFS DURING THE OVERNIGHT AND INTO THURSDAY MORNING.
LACY
&&
.PREV DISCUSSION... /ISSUED 835 AM CDT WED AUG 6 2014/
DISCUSSION...
A BAND OF HIGH BASED SHOWERS WAS OBSERVED ON RADAR ACROSS CENTRAL
OK THIS MORNING. LOOKING AT THE 12Z OUN SOUNDING...THE 500MB-300MB
LEVEL HAS MOISTENED UP QUITE A BIT COMPARED TO THE 00Z
SOUNDING...BUT LAPSE RATES ARE BASICALLY MOIST ADIABATIC IN THIS
LAYER AND THUS NO LIGHTNING HAS BEEN OBSERVED. THE HRRR AND LOCAL
WRF DATA ALL SUGGEST GRADUAL WEAKENING OF THIS BAND AS IT HEADS
EAST THRU THE DAY...WHICH MAKES SENSE GIVEN THE NORMAL DIURNAL
TREND FOR HIGH BASED ACTIVITY. HOWEVER THERE IS AT LEAST A SLIGHT
CHANCE OF THIS MAKING IT INTO OUR FORECAST AREA MAINLY WEST OF
HIGHWAY 75 LATE THIS MORNING INTO THE AFTERNOON BEFORE IT DOES
SO...THUS THE FORECAST HAS BEEN TWEAKED. THE LATEST DATA IS ALSO
NOT TOO EXCITED ABOUT AFTERNOON SURFACE BASED STORM
CHANCES...SUGGESTING THE BETTER CHANCES WILL BE NORTH UP IN
KANSAS WHERE A FOCUSING BOUNDARY LIES...IN THIS CASE AN EAST-WEST
ORIENTED SURFACE TROUGH. THE ECMWF DOES HAVE SOME DVLPMT NEAR THE
KS BORDER HOWEVER. THE GOING LOW POPS NEAR THE KS BORDER WILL BE
LEFT ALONE GIVEN THE UNCERTAINTY. UPDATED TEXT PRODUCTS HAVE BEEN
SENT.
LACY
PREV DISCUSSION... /ISSUED 651 AM CDT WED AUG 6 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR THROUGH 00Z. AFTER 00Z THUNDERSTORMS NEAR KS/OK
BORDER WILL SLIDE/DEVELOP SOUTHEAST INTO NORTHEAST OK
AND NORTHWEST AR. TAF SITES KBVO KTUL KRVS KXNA KFYV WITH
PROB30 RISK TSRA DURING EVENING / LATE NIGHT HOURS.
PREV DISCUSSION... /ISSUED 329 AM CDT WED AUG 6 2014/
DISCUSSION...
UNSETTLED WEATHER FOR THE NEXT SEVERAL DAYS. APPEARS AN H5 SHORT
WAVE WILL MOVE THROUGH THE RIDGE OVER THE ROCKIES AND SWING
THROUGH OK/KS/AR TODAY AND TONIGHT. THIS WILL TRY TO DRAG A
WEAK FRONT INTO SOUTHEAST KS. THE FRONT AND UPPER SUPPORT WILL
PROVIDE A CHANCE OF THUNDERSTORMS ACROSS MAINLY THE NORTHERN
PORTION OF THE FORECAST AREA. OCCASIONAL H5 SHORT WAVES AND
WESTERLY TO NORTHWESTERLY FLOW ALOFT WILL CONTINUE THROUGH THE
FORECAST CYCLE AND PROVIDE SOME CHANCES OF THUNDERSTORMS ALMOST
EACH DAY AND NIGHT.
BEST CHANCE OF RAIN APPEARS TO BE LATE TONIGHT INTO THURSDAY
MORNING...AND MAINLY OVER FAR NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS. APPEARS CONVECTION LIKELY TO DEVELOP OVER EASTERN KS NEAR
THE NEARLY STATIONARY FRONT. THIS PRECIPITATION SHOULD MOVE TO THE
SOUTHEAST AND PROVIDE A REASONABLY GOOD CHANCE FOR
RAIN...ESPECIALLY IN NORTHWEST ARKANSAS.
GENERALLY WARM AND HUMID CONDITIONS EXPECTED THROUGH THE NEXT 7
DAYS. SOME MODERATION IN TEMPS MAY BE POSSIBLE ABOUT TUESDAY AS
NORTHWEST FLOW COULD PUSH ANOTHER FRONT INTO THE AREA...BUT MODEL
BLENDS KEEP TEMPERATURES WARM FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 75 95 75 95 / 40 20 10 20
FSM 74 94 73 96 / 30 30 10 20
MLC 75 95 75 98 / 30 20 10 20
BVO 72 96 71 95 / 50 20 10 20
FYV 72 90 71 92 / 40 40 20 30
BYV 71 88 71 90 / 40 50 20 30
MKO 74 94 73 96 / 40 30 10 20
MIO 74 93 72 93 / 60 30 20 20
F10 74 95 74 95 / 30 20 10 20
HHW 74 94 73 98 / 10 20 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
616 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WILL SETTLE THROUGH THE AREA TODAY. COOLER AND LESS
HUMID CONDITIONS WILL OVERSPREAD THE STATE TONIGHT...AND LAST INTO
THIS COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATED PACKAGE AT 6 PM...TO TAKE OUT SHOWERS AND STORMS
EXCEPT FOR AREAS ACROSS THE NE PART OF CENTRAL PA.
STILL LOOKING OVER DATA ETC...WILL DO MORE UPDATES AS
NEEDED.
EARLIER DISCUSSION BELOW.
RUC SHOWS CAPES IN THE 500-1500J RANGE...ALONG WITH THE APPROACH
OF A POTENT JET STREAK...WE ARE SEEING RADAR GETTING MORE ACTIVE
AS CONVECTION BEGINS TO POP IN THE INCREASINGLY UNSTABLE AIRMASS.
LATEST HRRR SHOWS POPCORN RANDOM SHOWERS AND STORMS THROUGH MID
AFTERNOON...WITH ACTIVITY BEGINNING TO FADE RAPIDLY AFTER ABOUT
21Z. SHOULD LEAD TO A FINE MID SUMMER EVENING IN MOST LOCATIONS
AS DRIER AIR WORKS IN FROM THE NORTH.
THE OVERNIGHT WILL BE COOL AND DRY...RANGING FROM THE MID 40S OVER
THE NORTH TO THE MID 50S OVER THE SOUTH. THIS WILL BE ABOUT 5-10
DEG BELOW NORMAL.
A WEAK GRADIENT LATER TONIGHT WILL LEAD TO AT LEAST SOME PATCHY
FOG LATER AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
HIGH PRESSURE BUILDING OUT OF THE GR LAKES WILL BRING THE FIRST
OF SEVERAL FINE MID SUMMER DAYS TO THE AREA THURSDAY. THE ECMWF/GFS
HINT AT A WEAK SPOKE OF VORTICITY SWINGING DOWN AROUND THE NERN
UPPER TROUGH BRINGING SOME LIGHT SHOWERS TO FAR NERN AREAS DURING
THE AFTERNOON. THE GEFS DOESN`T SUPPORT THIS AND WITH UPPER
HEIGHTS CONTINUING TO BE FORECAST TO RISE...I DECIDED TO DOWNPLAY
THE ALREADY SMALL POPS. I WOUDN`T RULE OUT A STRAY SHOWER OR
SPRINKLE...BUT I OPTED FOR THE MORE OPTIMISTIC WORDING FOR THE
FORECAST...LEAVING OUT THE MENTION OF PRECIP.
HIGHS WILL BE VERY PLEASANT IN THE 70S TO LOWER 80S...STILL A TAD
BELOW NORMAL FOR EARLY AUGUST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
FOLLOWING BRIEF DEAMPLIFICATION BEHIND THE SEASONABLY STRONG UPPER
LEVEL TROUGH EXITING THE NEW ENGLAND STATES AND THE CANADIAN
MARITIMES...THE MEDIUM RANGE FCST WILL FEATURE A RETURN OF THE
FAMILIAR WRN RIDGE/ERN NOAM TROUGH PATTERN THAT HAS PREVAILED FOR
MOST OF THE SUMMER.
AMPLIFICATION OF SERN CANADA SHORTWAVE TROUGH INTO THE ERN U.S.
LATE-PERIOD SHOULD SUPPORT A SEWD PUSH OF A COLD FRONT INITIALLY
OVER THE NRN PLAINS...EVENTUALLY HELPING TO DISPLACE A QSTRNY
FRONT EXTENDING FROM THE PLAINS THROUGH THE S-CENTRAL APPLCHNS
AND INTO THE SOUTHEAST. THE 06/12Z OPERATIONAL MODELS AND
ENSEMBLES CONTINUE TO SHOW VARIABILITY IN THE PLACEMENT OF MAIN
PCPN AXIS ASSOCD WITH ONE OR MORE WAVES MOVG ALONG THE WAVY
BOUNDARY. A CONSENSUS BLEND STILL FAVORS AREAS TO THE SOUTH OF
CENTRAL PA /VA INTO THE CAROLINAS/ WHERE THE BEST MSTR/PWS WILL
RESIDE - ALTHOUGH WILL CONTINUE LOW POPS IN THE FAR SWRN/SCNTRL
ZONES THIS WEEKEND AS THIS AREA WILL BE VULNERABLE ON THE NRN EDGE
OF MSTR GRADIENT/DEVELOPING SELY LLVL UPSLOPE FLOW.
NORTH TO EAST LLVL FLOW TO THE S OF NEW ENGLAND HP SHOULD FAVOR
NEAR TO BELOW NORMAL HIGHS AND PERHAPS COOL NIGHTTIME LOWS
/ASSUMING CLR SKIES AND ABNORMALLY DRY AIR/. PESKY LOW CLOUDS IN
DEVELOPING ESE FLOW MAY ALSO ACT TO TEMPER DAYTIME TEMPS WHILE
POTENTIALLY KEEPING THINGS WARMER AT NIGHT. OVERALL NOT EXPECTING
ANY MAJOR WARMING TRENDS.
SPREAD BTWN OP GFS/ECMWF REALLY INCREASES INTO THE MIDDLE OF NEXT
WEEK...WITH THE GFS MUCH MORE AGGRESSIVE IN RETURNING THE
AFOREMENTIONED FRONTAL ZONE NWD WHILE THE ECMWF KEEPS IT
SUPPRESSED. WPC SEEMS TO FAVOR ECMWF SOLN WHICH BRINGS A COLD
FRONT THRU THE AREA ON WED FOLLOWED BY MODEST COOL DOWN IN ITS
WAKE BY LATER NEXT WEEK.
CONFIDENCE IS BELOW AVG GIVEN THE COMPLEX PATTERN AND LARGE MODEL
SPREAD/DETAIL UNCERTAINTY.
&&
.AVIATION /22Z WEDNESDAY THROUGH MONDAY/...
ALTOONA IS THE LONE HOLDOUT WITH A 2600` CEILING AS OF 2PM...BUT
THIS TOO SHOULD RISE AND MIX OUT BEFORE TOO LONG. OTHER THAN A HIT
AND MISS SHOWER OR THUNDERSTORM BRINGING BRIEFLY REDUCED
CONDITIONS INTO THE EARLY EVENING...CONDITIONS WILL REMAIN VFR
INTO THE OVERNIGHT.
AS EVENING APPROACHES..SHOWERS AND STORMS WILL BEGIN TO FADE.
OTHER THAN SOME PATCHY FOG OVERNIGHT...EXPECT VFR CONDITIONS AS
DRIER BEGINS TO MOVE INTO THE REGION.
TOMORROW WILL BEGIN A SEVERAL DAY PERIOD OF NON-EVENTFUL WEATHER
AND PRIMARILY VFR CONDITIONS.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN-MON...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
356 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WILL SETTLE THROUGH THE AREA TODAY. COOLER AND LESS
HUMID CONDITIONS WILL OVERSPREAD THE STATE TONIGHT...AND LAST INTO
THIS COMING WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
2 PM UPDATE...
RUC SHOWS CAPES IN THE 500-1500J RANGE...ALONG WITH THE APPROACH
OF A POTENT JET STREAK...WE ARE SEEING RADAR GETTING MORE ACTIVE
AS CONVECTION BEGINS TO POP IN THE INCREASINGLY UNSTABLE AIRMASS.
LATEST HRRR SHOWS POPCORN RANDOM SHOWERS AND STORMS THROUGH MID
AFTERNOON...WITH ACTIVITY BEGINNING TO FADE RAPIDLY AFTER ABOUT
21Z. SHOULD LEAD TO A FINE MID SUMMER EVENING IN MOST LOCATIONS
AS DRIER AIR WORKS IN FROM THE NORTH.
THE OVERNIGHT WILL BE COOL AND DRY...RANGING FROM THE MID 40S OVER
THE NORTH TO THE MID 50S OVER THE SOUTH. THIS WILL BE ABOUT 5-10
DEG BELOW NORMAL.
A WEAK GRADIENT LATER TONIGHT WILL LEAD TO AT LEAST SOME PATCHY
FOG LATER AFTER MIDNIGHT.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
HIGH PRESSURE BUILDING OUT OF THE GR LAKES WILL BRING THE FIRST
OF SEVERAL FINE MID SUMMER DAYS TO THE AREA THURSDAY. THE ECMWF/GFS
HINT AT A WEAK SPOKE OF VORTICITY SWINGING DOWN AROUND THE NERN
UPPER TROUGH BRINGING SOME LIGHT SHOWERS TO FAR NERN AREAS DURING
THE AFTERNOON. THE GEFS DOESN`T SUPPORT THIS AND WITH UPPER
HEIGHTS CONTINUING TO BE FORECAST TO RISE...I DECIDED TO DOWNPLAY
THE ALREADY SMALL POPS. I WOUDN`T RULE OUT A STRAY SHOWER OR
SPRINKLE...BUT I OPTED FOR THE MORE OPTIMISTIC WORDING FOR THE
FORECAST...LEAVING OUT THE MENTION OF PRECIP.
HIGHS WILL BE VERY PLEASANT IN THE 70S TO LOWER 80S...STILL A TAD
BELOW NORMAL FOR EARLY AUGUST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
FOLLOWING BRIEF DEAMPLIFICATION BEHIND THE SEASONABLY STRONG UPPER
LEVEL TROUGH EXITING THE NEW ENGLAND STATES AND THE CANADIAN
MARITIMES...THE MEDIUM RANGE FCST WILL FEATURE A RETURN OF THE
FAMILIAR WRN RIDGE/ERN NOAM TROUGH PATTERN THAT HAS PREVAILED FOR
MOST OF THE SUMMER.
AMPLIFICATION OF SERN CANADA SHORTWAVE TROUGH INTO THE ERN U.S.
LATE-PERIOD SHOULD SUPPORT A SEWD PUSH OF A COLD FRONT INITIALLY
OVER THE NRN PLAINS...EVENTUALLY HELPING TO DISPLACE A QSTRNY
FRONT EXTENDING FROM THE PLAINS THROUGH THE S-CENTRAL APPLCHNS
AND INTO THE SOUTHEAST. THE 06/12Z OPERATIONAL MODELS AND
ENSEMBLES CONTINUE TO SHOW VARIABILITY IN THE PLACEMENT OF MAIN
PCPN AXIS ASSOCD WITH ONE OR MORE WAVES MOVG ALONG THE WAVY
BOUNDARY. A CONSENSUS BLEND STILL FAVORS AREAS TO THE SOUTH OF
CENTRAL PA /VA INTO THE CAROLINAS/ WHERE THE BEST MSTR/PWS WILL
RESIDE - ALTHOUGH WILL CONTINUE LOW POPS IN THE FAR SWRN/SCNTRL
ZONES THIS WEEKEND AS THIS AREA WILL BE VULNERABLE ON THE NRN EDGE
OF MSTR GRADIENT/DEVELOPING SELY LLVL UPSLOPE FLOW.
NORTH TO EAST LLVL FLOW TO THE S OF NEW ENGLAND HP SHOULD FAVOR
NEAR TO BELOW NORMAL HIGHS AND PERHAPS COOL NIGHTTIME LOWS
/ASSUMING CLR SKIES AND ABNORMALLY DRY AIR/. PESKY LOW CLOUDS IN
DEVELOPING ESE FLOW MAY ALSO ACT TO TEMPER DAYTIME TEMPS WHILE
POTENTIALLY KEEPING THINGS WARMER AT NIGHT. OVERALL NOT EXPECTING
ANY MAJOR WARMING TRENDS.
SPREAD BTWN OP GFS/ECMWF REALLY INCREASES INTO THE MIDDLE OF NEXT
WEEK...WITH THE GFS MUCH MORE AGGRESSIVE IN RETURNING THE
AFOREMENTIONED FRONTAL ZONE NWD WHILE THE ECMWF KEEPS IT
SUPPRESSED. WPC SEEMS TO FAVOR ECMWF SOLN WHICH BRINGS A COLD
FRONT THRU THE AREA ON WED FOLLOWED BY MODEST COOL DOWN IN ITS
WAKE BY LATER NEXT WEEK.
CONFIDENCE IS BELOW AVG GIVEN THE COMPLEX PATTERN AND LARGE MODEL
SPREAD/DETAIL UNCERTAINTY.
&&
.AVIATION /19Z WEDNESDAY THROUGH MONDAY/...
ALTOONA IS THE LONE HOLDOUT WITH A 2600` CEILING AS OF 2PM...BUT
THIS TOO SHOULD RISE AND MIX OUT BEFORE TOO LONG. OTHER THAN A HIT
AND MISS SHOWER OR THUNDERSTORM BRINGING BRIEFLY REDUCED
CONDITIONS INTO THE EARLY EVENING...CONDITIONS WILL REMAIN VFR
INTO THE OVERNIGHT.
AS EVENING APPROACHES..SHOWERS AND STORMS WILL BEGIN TO FADE.
OTHER THAN SOME PATCHY FOG OVERNIGHT...EXPECT VFR CONDITIONS AS
DRIER BEGINS TO MOVE INTO THE REGION.
TOMORROW WILL BEGIN A SEVERAL DAY PERIOD OF NON-EVENTFUL WEATHER
AND PRIMARILY VFR CONDITIONS.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN-MON...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
231 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WILL SETTLE THROUGH THE AREA TODAY. COOLER AND LESS
HUMID CONDITIONS WILL OVERSPREAD THE STATE TONIGHT...AND LAST INTO
THIS COMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
2 PM UPDATE...
RUC SHOWS CAPES IN THE 500-1500J RANGE...ALONG WITH THE APPROACH
OF A POTENT JET STREAK...WE ARE SEEING RADAR GETTING MORE ACTIVE
AS CONVECTION BEGINS TO POP IN THE INCREASINGLY UNSTABLE AIRMASS.
LATEST HRRR SHOWS POPCORN RANDOM SHOWERS AND STORMS THROUGH MID
AFTERNOON...WITH ACTIVITY BEGINNING TO FADE RAPIDLY AFTER ABOUT
21Z. SHOULD LEAD TO A FINE MID SUMMER EVENING IN MOST LOCATIONS
AS DRIER AIR WORKS IN FROM THE NORTH.
THE OVERNIGHT WILL BE COOL AND DRY...RANGING FROM THE MID 40S OVER
THE NORTH TO THE MID 50S OVER THE SOUTH. THIS WILL BE ABOUT 5-10
DEG BELOW NORMAL.
A WEAK GRADIENT LATER TONIGHT WILL LEAD TO AT LEAST SOME PATCHY
FOG LATER AFTER MIDNIGHT.
&&
.SHORT TERM /THURSDAY/...
HIGH PRESSURE BUILDING OUT OF THE GR LAKES WILL BRING THE FIRST
OF SEVERAL FINE MID SUMMER DAYS TO THE AREA THURSDAY. THE ECMWF/GFS
HINT AT A WEAK SPOKE OF VORTICITY SWINGING DOWN AROUND THE NERN
UPPER TROUGH BRINGING SOME LIGHT SHOWERS TO FAR NERN AREAS DURING
THE AFTERNOON. THE GEFS DOESN`T SUPPORT THIS AND WITH UPPER
HEIGHTS CONTINUING TO BE FORECAST TO RISE...I DECIDED TO DOWNPLAY
THE ALREADY SMALL POPS. I WOUDN`T RULE OUT A STRAY SHOWER OR
SPRINKLE...BUT I OPTED FOR THE MORE OPTIMISTIC WORDING FOR THE
FORECAST...LEAVING OUT THE MENTION OF PRECIP.
HIGHS WILL BE VERY PLEASANT IN THE 70S TO LOWER 80S...STILL A TAD
BELOW NORMAL FOR EARLY AUGUST.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
SHORTWAVE RIDGING AND 500MB HEIGHT RISES SHOULD GRADUALLY REPLACE
THE DEPARTING UPPER TROUGH/CYC FLOW ALOFT OVER THE REGION FRI-
SUN. AT THE SFC...HIGH PRESSURE MIGRATING S/SEWD FROM THE UPPER
GRT LKS/SERN CANADA SHOULD PROVIDE A STRING OF DRY WX WITH
PLEASANT DAYS AND RELATIVELY COOL NGTS. 05/12Z MODELS ARE IN
DECENT AGREEMENT IN KEEPING THE MAIN AXIS OF PCPN SOUTH OF PA
ALONG A NW/SE ORIENTED FRONTAL ZONE/INVERTED TROUGH AXIS LOCATED
FROM THE MID MO/LWR OH VLYS INTO THE SRN/CNTRL APPLCHNS AND SRN
MID-ATLC/SE STATES. THE PCPN PATTERN SHOULD BECOME MORE UNSETTLED
INTO THE MIDDLE OF NEXT WEEK WITH INCR MSTR/SLY WINDS CONSISTENT
WITH RETURN FLOW ON BACKSIDE OF DEPARTING HP...WITH A FRONTAL
SYSTEM APPROACHING THE AREA FROM THE NW. CONSENSUS BLEND OF THE
LATEST OPERATIONAL AND ENSEMBLE GUIDANCE FAVORS NEAR TO SLIGHTLY
BELOW NORMAL TEMPS DURING THE PERIOD.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
ALTOONA IS THE LONE HOLDOUT WITH A 2600` CEILING AS OF 2PM...BUT
THIS TOO SHOULD RISE AND MIX OUT BEFORE TOO LONG. OTHER THAN A HIT
AND MISS SHOWER OR THUNDERSTORM BRINGING BRIEFLY REDUCED
CONDITIONS INTO THE EARLY EVENING...CONDITIONS WILL REMAIN VFR
INTO THE OVERNIGHT.
AS EVENING APPROACHES..SHOWERS AND STORMS WILL BEGIN TO FADE.
OTHER THAN SOME PATCHY FOG OVERNIGHT...EXPECT VFR CONDITIONS AS
DRIER BEGINS TO MOVE INTO THE REGION.
TOMORROW WILL BEGIN A SEVERAL DAY PERIOD OF NON-EVENTFUL WEATHER
AND PRIMARILY VFR CONDITIONS.
OUTLOOK...
THU-SAT...MAINLY VFR. PATCHY FOG/LOW CLOUDS POSSIBLE EARLY.
SUN-MON...MAINLY VFR BUT WITH ISOLATED SHOWERS AND THUNDERSTORMS.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...LAMBERT/STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS FORT WORTH TX
1237 PM CDT WED AUG 6 2014
.AVIATION...
FOR THE 18Z TAFS...VFR CONDITIONS AND SOUTH WINDS ARE EXPECTED
THROUGH THE VALID FORECAST PERIOD.
THE ONLY AVIATION WEATHER CONCERN IS ISOLATED THUNDERSTORM CHANCES
ONCE AGAIN DURING THE PEAK HEATING HOURS OF THE DAY TODAY...MUCH
LIKE WHAT TRANSPIRED YESTERDAY.
A 17Z AMDAR RAOB SHOWED THAT CONDITIONS ACROSS THE METROPLEX WERE
SLIGHTLY CAPPED. HOWEVER...IF AIR CAN WARM UP INTO THE UPPER 90S
WITHOUT LOW-LEVEL MOISTURE MIXING OUT...WE WILL ONCE AGAIN BECOME
CONVECTIVELY UNSTABLE LATE THIS AFTERNOON AROUND THE METROPLEX.
JUST LIKE YESTERDAY...DID NOT PLACE SHOWERS OR STORMS IN THE TAF
AT THIS TIME BECAUSE THE CHANCES OF ANY ISOLATED STORM IMPACTING
ONE OF THE TAFS SITES IS FAIRLY SMALL. WILL HAVE TO MONITOR RADAR
AND SATELLITE TRENDS THIS AFTERNOON AND AMEND TO INCLUDE VICINITY
SHOWERS OR THUNDER IN THE TAFS IF IT LOOKS LIKE SOMETHING IS GOING
TO DEVELOP NEAR AREA TAF SITES.
ALTHOUGH THE AMDAR RAOB IS SIMILAR TO YESTERDAYS IN
APPEARANCE...VISIBLE SATELLITE IMAGERY SHOWS MUCH LESS COVERAGE OF
SURFACE BASED CUMULUS CLOUDS AROUND NORTH TEXAS AT THIS TIME
COMPARED TO YESTERDAY. THE LACK OF CUMULUS CLOUDS WILL NOT PREVENT
AN ISOLATED STORM FROM DEVELOPING LATER ON...BUT THIS MAY BE
INDICATIVE OF MOISTURE MIXING OUT MORE TODAY THAN IT DID YESTERDAY
DURING THE PEAK HEATING HOURS OF THE DAY. IF MOISTURE IS IN THE
PROCESS OF MIXING OUT...THEN WE WILL END UP MORE CAPPED LATE THIS
AFTERNOON RESULTING IN NO STORMS NEAR AREA AIRPORTS.
CAVANAUGH
&&
.UPDATE...
THE MIDDAY UPDATE WILL CLEAN UP/DIMINISH SKY COVERAGE ACROSS THE
CWA AND MAKE SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDS. 75
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT WED AUG 6 2014/
HAVING A BIT OF A CONUNDRUM IN REGARDS TO STORMS. ATMOSPHERE WILL
BE POTENTIALLY UNSTABLE IN THE AFTERNOON...BUT THERE REALLY IS NO
GREAT FORCING. TODAY...4KM WRF IS GOING FOR BROKE WITH A LINE OF
STORMS ACROSS OKLAHOMA STRETCHING SOUTH INTO NORTHWEST NORTH
TX...BUT IT IS WAY MORE AGGRESSIVE THAN OTHER MODELS. WRF ARW
DEVELOPS ISOLATED CONVECTION IN THE METROPLEX...BUT AGAIN NOT
SUPPORTED BY OTHER MODELS. FORECAST SOUNDINGS SHOW MOISTURE IS
MORE SHALLOW TODAY THAN YESTERDAY. THE RAP FORECASTS AN UNSTABLE
ATMOSPHERE WITH 450 J/KG CAPE...BUT DOES NOT DEVELOP STORMS.
FOR THURSDAY...A SHORT WAVE MOVES ACROSS THE CENTRAL PLAINS...BUT
THE NAM DEVELOPS SOME CONVECTION IN WESTERN ZONES AND DRIVES IT
SOUTH DURING THE AFTERNOON. THE TTU WRF PLACES A SMALL CONVECTIVE
CLUSTER IN YOUNG/STEPHENS COUNTIES...BUT AGAIN ACTIVITY IS NOT
SUPPORTED BY OTHER MODELS.
I HAVE OPTED TO KEEP ISOLATED STORMS IN THE SOUTHEAST AND ADDED
ISOLATED STORMS IN THE NORTHWEST TODAY. WILL NOT ADD ANY PRECIP
THROUGH THE REST OF THE FORECAST BUT MAY HAVE TO BUMP SOME AREAS
UP TO LOW CHANCES TONIGHT IF THURSDAY LOOKS ANY WETTER.
TEMPERATURES ARE GOING TO CLIMB SLOWLY AS THE RIDGE BUILDS
IN...AND HAVE NUMEROUS AREAS WITH TRIPLE DIGITS BY SUNDAY. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 78 97 78 99 / 10 10 10 10 10
WACO, TX 97 76 98 75 98 / 10 10 10 10 5
PARIS, TX 92 73 94 74 94 / 10 10 20 10 10
DENTON, TX 95 76 96 77 97 / 10 10 10 10 10
MCKINNEY, TX 95 75 95 76 97 / 10 10 10 10 10
DALLAS, TX 97 78 97 78 99 / 10 10 10 10 10
TERRELL, TX 97 75 96 75 98 / 10 10 10 10 10
CORSICANA, TX 96 74 95 75 97 / 10 10 10 10 10
TEMPLE, TX 95 74 96 74 97 / 10 10 10 10 5
MINERAL WELLS, TX 98 74 99 74 98 / 10 10 10 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
1122 AM CDT WED AUG 6 2014
.DISCUSSION...ONLY CHANGE OF SIGNIFICANCE TO TODAY/S FORECAST WAS
TO EXPAND MENTION OF PRECIP INLAND THROUGH MID AFTERNOON AS RAP
AND HRRR ARE HINTING AT ISOLATED PRECIP. NOT OVERLY
CONFIDENT IN THIS...HOWEVER...GIVEN LLVL WIND AND THERMAL
PROFILES /THUS WILL ONLY GO WITH 10 POPS/. ALSO EDITED CLOUD
COVER BASED OFF CURRENT TRENDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 97 77 97 77 96 / 10 10 10 10 20
VICTORIA 98 77 97 76 96 / 10 10 10 10 20
LAREDO 102 78 103 82 103 / 10 10 10 10 10
ALICE 100 76 99 76 99 / 10 10 10 10 20
ROCKPORT 91 80 94 81 93 / 10 10 10 10 20
COTULLA 102 76 102 76 101 / 10 10 10 10 10
KINGSVILLE 99 77 98 76 98 / 10 10 10 10 20
NAVY CORPUS 91 80 92 81 92 / 10 10 10 10 20
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
UPDATE...HART/79
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
1118 AM CDT WED AUG 6 2014
.UPDATE...
THE MIDDAY UPDATE WILL CLEAN UP/DIMINISH SKY COVERAGE ACROSS THE
CWA AND MAKE SOME MINOR ADJUSTMENTS TO THE HOURLY GRIDS. 75
&&
.AVIATION...
/ISSUED 658 AM CDT WED AUG 6 2014/
CONCERNS...ISOLATED AFTERNOON/EARLY EVENING STORMS POSSIBLE AT THE
METROPLEX TAF SITES.
ISOLATED THUNDERSTORMS ARE POSSIBLE THIS AFTERNOON AND EARLY
EVENING ACROSS NORTH TEXAS AS A WEAK UPPER LEVEL DISTURBANCE
MOVES ACROSS OKLAHOMA. OTHERWISE...THE UPPER LEVEL RIDGE WILL
CONTINUE TO DOMINATE THE WEATHER ACROSS NORTH AND CENTRAL TEXAS.
ALTHOUGH THUNDERSTORM CHANCES AT THE INDIVIDUAL TAF SITES ARE TOO
LOW TO MENTION IN THE TAFS...BE AWARE THAT THE STORMS WILL HAVE THE
POTENTIAL TO PRODUCE WIND GUSTS OVER 35 KNOTS AND CLOUD TO GROUND
LIGHTNING. SOUTH WINDS AT 10 KNOTS OR LESS WILL PREVAIL. 58
&&
.PREV DISCUSSION... /ISSUED 348 AM CDT WED AUG 6 2014/
HAVING A BIT OF A CONUNDRUM IN REGARDS TO STORMS. ATMOSPHERE WILL
BE POTENTIALLY UNSTABLE IN THE AFTERNOON...BUT THERE REALLY IS NO
GREAT FORCING. TODAY...4KM WRF IS GOING FOR BROKE WITH A LINE OF
STORMS ACROSS OKLAHOMA STRETCHING SOUTH INTO NORTHWEST NORTH
TX...BUT IT IS WAY MORE AGGRESSIVE THAN OTHER MODELS. WRF ARW
DEVELOPS ISOLATED CONVECTION IN THE METROPLEX...BUT AGAIN NOT
SUPPORTED BY OTHER MODELS. FORECAST SOUNDINGS SHOW MOISTURE IS
MORE SHALLOW TODAY THAN YESTERDAY. THE RAP FORECASTS AN UNSTABLE
ATMOSPHERE WITH 450 J/KG CAPE...BUT DOES NOT DEVELOP STORMS.
FOR THURSDAY...A SHORT WAVE MOVES ACROSS THE CENTRAL PLAINS...BUT
THE NAM DEVELOPS SOME CONVECTION IN WESTERN ZONES AND DRIVES IT
SOUTH DURING THE AFTERNOON. THE TTU WRF PLACES A SMALL CONNECTIVE
CLUSTER IN YOUNG/STEPHENS COUNTIES...BUT AGAIN ACTIVITY IS NOT
SUPPORTED BY OTHER MODELS.
I HAVE OPTED TO KEEP ISOLATED STORMS IN THE SOUTHEAST AND ADDED
ISOLATED STORMS IN THE NORTHWEST TODAY. WILL NOT ADD ANY PRECIP
THROUGH THE REST OF THE FORECAST BUT MAY HAVE TO BUMP SOME AREAS
UP TO LOW CHANCES TONIGHT IF THURSDAY LOOKS ANY WETTER.
TEMPERATURES ARE GOING TO CLIMB SLOWLY AS THE RIDGE BUILDS
IN...AND HAVE NUMEROUS AREAS WITH TRIPLE DIGITS BY SUNDAY. 84
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 98 78 97 78 99 / 10 10 10 10 10
WACO, TX 97 76 98 75 98 / 10 10 10 10 5
PARIS, TX 92 73 94 74 94 / 10 10 20 10 10
DENTON, TX 95 76 96 77 97 / 10 10 10 10 10
MCKINNEY, TX 95 75 95 76 97 / 10 10 10 10 10
DALLAS, TX 97 78 97 78 99 / 10 10 10 10 10
TERRELL, TX 97 75 96 75 98 / 10 10 10 10 10
CORSICANA, TX 96 74 95 75 97 / 10 10 10 10 10
TEMPLE, TX 95 74 96 74 97 / 10 10 10 10 5
MINERAL WELLS, TX 98 74 99 74 98 / 10 10 10 5 10
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
416 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WAS APPROAHCING OUR REGION FROM EASTERN KENTUCKY.
THIS FRONT WILL MOVE SOUTH THROUGH THE REGION TONIGHT...REACHING
THE GULF STATES BY LATE THURSDAY. A SERIES OF LOW PRESSURE SYSTEMS
WILL MOVE ALONG THE BOUNDARY FRIDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 315 PM EDT WEDNESDAY...
A COLD FRONT WAS MAKING ITS WAY INTO THE WESTERN PART OF THE
FORECAST AREA. THE FRONT IS EXPECTED TO CROSS THE AREA TONIGHT AND
BE SOUTH OF THE REGION BY THURSDAY MORNING. ISOLATED TO SCATTERED
SHOWERS AND STORMS ARE EXPECTED THE REMAINDER OF THIS AFTERNOON INTO
THE EVENING HOURS ALONG IN ADVANCE OF THE FRONT. HRRR AND RNK WRK-
ARW MODELS HAVE BEEN DOING DO A GOOD JOB THE PAST FEW DAYS WITH
TIMING AND LOCATION OF LATE AFTERNOON AND EARLY EVENING ACTIVITY.
WILL CONTINUE PLACE STRONG WEIGHT ON THEIR SOLUTIONS FOR WHERE THE
FOCUS OF THE BEST COVERAGE WILL BE. THAT REGION WILL PRIMARILY BE
AREAS NEAR AND NORTHWEST TO NORTHEAST OF LYNCHBURG AND ALSO ACROSS
THE NORTHERN MOUNTAINS OF NC AND PARTS OF THE MOUNTAIN EMPIRE AND
NEW RIVER VALLEY REGION OF SOUTHWEST VIRGINIA. PRECIPITATION IS
EXPECTED TO COMPLETELY DISSIPATE BETWEEN MIDNIGHT AND 200 AM
TONIGHT. THE NOTABLY DRIER AIR BEHIND THE FRONT IS NOT EXPECT TO
ARRIVE UNTIL THURSDAY AFTERNOON. THIS WILL ALLOW FOR ONE MORE NIGHT
OF SOME PATCHY MOUNTAIN AND RIVER VALLEY FOG...ESPECIALLY IN AREAS
THAT RECEIVE PRECIPITATION THIS AFTERNOON AND EVENING. HIGH LEVEL
CLOUDS ARE EXPECTED OVERNIGHT FOR MUCH OF THE REGION. LOWER...MORE
NUMEROUS CLOUDS ARE POSSIBLE NEAR A BLUEFIELD TO LEWISBURG WV LINE
WHERE AN UPSLOPE FLOW WITHIN A SHALLOW MOIST LAYER WILL HELP RE-
ESTABLISH LOW LEVEL CLOUDS AT AND BELOW THE INVERSION LEVEL.
ON THURSDAY...HIGH PRESSURE WILL BUILD INTO OH/PA WITH THE SOUTHERN
EXTENT OF ITS AXIS NOSING INTO THE FORECAST AREA. WITH IT WILL COME
DRIER AND COOLER WEATHER. WHILE NOT FORECAST...WE MAY HAVE TO WATCH
FOR SOME LATE DAY ISOLATED SHOWERS IN THE FAR SOUTHERN PART OF THE
AREA WHERE DAYTIME HEATING WILL BE MAXIMIZED COINCIDENT TO WHERE THE
BEST REMAINING LOW LEVEL MOISTURE WILL BE LOCATED. AT THIS
TIME...CONFIDENCE IS TOO LOW TO INCLUDE THE ISOLATED SHOWERS IN THE
FORECAST. HIGH TEMPERATURES WILL RANGE FROM AROUND 80 TO THE LOWER
80S ACROSS THE MOUNTAINS WITH LOW TO MID 80S ACROSS THE PIEDMONT.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 400 PM EDT WEDNESDAY...
THE FORECAST GOING INTO THE WEEKEND SHOULD LOOK FAMILIAR TO WHAT
WAS EXPERIENCED THE END OF LAST WEEK WITH TRANSITION BACK TO MUCH
COOLER THAN NORMAL TEMPERATURES.
THE UPPER LEVEL PATTERN REMAINS PRETTY MUCH UNCHANGED...FAVORING A
RIDGE OF HIGH PRESSURE OVER THE PLAINS AND ROCKIES...AND
TROUGHINESS OVER THE EASTERN CONUS...THE DEGREE OF AMPLIFICATION
THE ONLY THING THAT HAS BEEN CHANGING WITH TIME. TO START THE DAY
FRIDAY...THE UPPER LEVEL TROUGH WILL SLIDE OFF THE EAST COAST WITH
SURFACE HIGH PRESSURE WEDGING DOWN THE EAST SIDE OF THE
APPALACHIANS. THIS WILL SET STAGE FOR A MULTIDAY PERIOD OF
EASTERLY WINDS OFF THE ATLANTIC OCEAN...A PATTERN THAT GENERALLY
FEATURES COOL TEMPERATURES AND ABUNDANT LOW LEVEL CLOUD COVER FOR
MUCH OF OUR FORECAST AREA.
TO GO ALONG WITH THE COOL CLOUD COVER THERE WILL BE SHOWERS.
A SURFACE FRONT WILL BE NEARLY STATIONARY...JUST SOUTH OF OUR
FORECAST AREA...EXTENDING FROM SOUTH CAROLINAS WESTWARD INTO THE
MID MS VALLEY. THIS FRONT WILL BECOME THE FOCUS FOR SHOWERS AND
THUNDERSTORMS...THE STRONGEST STORMS PRIMARILY SOUTH AND WEST OF
OUR FORECAST AREA. WEDGE OF STABLE AIR ON THE EAST SIDE OF THE
MTNS WILL PROHIBIT MUCH IN THE WAY OF STORMINESS HERE...HOWEVER
COMBINATION OF ISENTROPIC LIFT...AND THE EASTERLY UPSLOPE WIND
FLOW WILL PROVIDE LIFT FOR PERIODIC SHOWERS ACROSS OUR FCST AREA
BEGINNING FRIDAY AND CONTINUING THROUGH THE WEEKEND. IN
GENERAL...QPF IS EXPECTED TO BE LESS THAN AN INCH...WITH THE
EXCEPTION OF AREAS WEST OF I77 WHERE MORE SUN AND INSTABILITY WILL
EXIST...AND FARTHER SOUTH INTO NORTH CAROLINA CLOSER TO INFLUENCE
OF THE SURFACE FRONT.
BOTH THE GFS AND ECMWF DEVELOP CONVECTION ALONG AND NORTH OF THE
FRONTAL BOUNDARY FROM THE LOWER MISSOURI VALLEY EAST TOWARD THE
OHIO VALLEY LATE THURSDAY NIGHT...THEN RIDE THE CONVECTION
SOUTHEAST INTO THE MOUNTAINS BY MIDDAY FRIDAY. RAIN SPREADS EAST
FRIDAY AFTERNOON INTO FRIDAY NIGHT. THESE SAME MODELS ARE ALSO
ADVERTISING HIGH CHC THREAT FOR PRECIP RIGHT ON THROUGH THE
WEEKEND.
WITH ABUNDANT CLOUD COVER...PRECIPITATION...AND AN EASTERLY WIND...
WENT WELL BELOW CLIMO. HIGHS THIS WEEKEND WILL LIKELY BE 8 TO 15
DEGREES BELOW NORMAL. FOR SATURDAY WE WILL BE LUCKY TO TOUCH 70.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 410 PM EDT WEDNESDAY...
COOL PATTERN LOOKS LIKE IT WILL LINGER THROUGH MONDAY BEFORE
WARMING BACK UP THE MIDDLE OF NEXT WEEK.
OVERALL THIS PERIOD WILL BE CHARACTERIZED BY THE SAME NEARLY
STATIONARY...WAVY FRONT POSITIONED JUST SOUTH OF THE FORECAST
AREA. SFC HIGH WILL BE OVER THE MID ATLANTIC/NORTHEAST WEDGING
SW...BUT THIS AIRMASS IS EXPECTED TO MODIFY WITH TIME...RESULTING
IN A UPWARD TEMPERATURE TREND TUESDAY AND WEDNESDAY.
MAINTAINED DAILY THREAT FOR SHOWERS THROUGH THE PERIOD. INTRODUCED
THUNDER BACK IN THE FORECAST FOR MID WEEK...THE RETURN OF SOME
SUN PROVIDING INSTABILITY TO FEED DEEPER CONVECTION.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
AS OF 130 PM EDT WEDNESDAY...
LOW PRESSURE WAS LOCATED OVER SOUTHERN OHIO. THIS LOW WAS SITUATED
ALONG A COLD FRONT THAT EXTENDED SOUTHWEST OF THE LOW THROUGH
EASTERN KENTUCKY...AND EAST OF THE LOW THROUGH NORTHERN VIRGINIA.
THIS AFTERNOON AND EVENING THE LOW WILL PROGRESS EASTWARD WHILE
ITS TRAILING KY COLD FRONT MOVES INTO AND THROUGH THE AREA. WE
EXPECT SHOWERS AND STORMS TO DEVELOP TO HAVE ISOLATED TO SCATTERED
COVERAGE ACROSS THE MOUNTAINS WITH ISOLATED COVERAGE EAST OF THE
CREST OF THE BLUE RIDGE. THROUGH THE EARLY EVENING...MOST OF THE
ACTIVITY WILL WANE AND GRADUALLY DRIFT EASTWARD WITH BOTH THE
PREVAILING LOW LEVEL FLOW AND PROGRESSION OF THE FRONT. OTHER
THAN FOR SOME BRIEF PERIODS UNDER SOME OF THE HEAVIER CELLS...VFR
CONDITIONS ARE EXPECTED.
DRIER AIR WILL START ENTERING THE REGION LATER TONIGHT IN THE
WAKE OF THE FRONT AND WITH THE ARRIVAL OF SURFACE HIGH PRESSURE.
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE NIGHT SAVE MOUNTAIN
AND RIVER VALLEY PATCHY FOG. ENOUGH RESIDUAL LOW LEVEL MOISTURE
MAY GET TRAPPED UNDER THE INVERSION AND LIFTED UPSLOPE IN THE WEST
FOR A BRIEF PERIOD OF MVFR CIGS BETWEEN KBLF-KLWB. ANY SUB-VFR
CONDITIONS WILL QUICKLY IMPROVE TO VFR AROUND 12-13Z/8-9AM
THURSDAY.
EXTENDED AVIATION DISCUSSION...
LENGTHY PERIOD OF SUB-VFR CONDITIONS POSSIBLE FRIDAY INTO SATURDAY
AS THE FRONT BUCKLES NORTH AGAIN WITH THE APPROACH AND PASSAGE OF
AN AREA OF LOW PRESSURE. GOOD POTENTIAL FOR PLENTY OF RAIN...LOW
CLOUDS AND REDUCED VISIBILITIES.
SUNDAY INTO MONDAY...COLD AIR DAMMING WEDGE IN PLACE ACROSS THE
EAST WITH POTENTIAL FOR CONTINUATION OF SUB-VFR CATEGORY
CONDITIONS. MODELS VARY ON THE EXTENT ANOTHER UPPER LOW WILL
SPREAD ADDITIONAL PRECIPITATION INTO AT LEAST THE WESTERN PARTS OF
THE AREA BY MONDAY...POSSIBLY CONVECTIVE OUTSIDE THE INFLUENCE OF
THE WEDGE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...DS
SHORT TERM...PM
LONG TERM...PM
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
144 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT WAS APPROAHCING OUR REGION FROM EASTERN KENTUCKY.
THIS FRONT WILL MOVE SOUTH THROUGH THE REGION TONIGHT...REACHING
THE GULF STATES BY LATE THURSDAY. A SERIES OF LOW PRESSURE SYSTEMS
WILL MOVE ALONG THE BOUNDARY FRIDAY THROUGH MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 150 PM EDT WEDNESDAY...
A SURFACE COLD FRONT IS STILL WEST OF THE REGION...BUT APPROACHING
THROUGH EASTERN KENTUCKY. AN AREA OF LOW PRESSURE WAS ALONG THE
FRONT ACROSS SOUTHERN OHIO...AND THEN THE FRONT EXTENDED EASTWARD
INTO NORTHERN VIRGINIA. A SMALL CLUSTER OF SHOWERS HAS BEEN
RIDGING ALONG THE BOUNDARY IN VIRGINIA...WITH MOST OF THE ACTIVITY
NORTH OF THE FORECAST REGION. HRRR AND RNK WRF-ARW GUIDANCE HAS
BEEN VERY WELL THE PAST FEW DAYS IN NARROWING DOWN THE PREFERRED
AREAS OF CONVECTION DURING THE AFTERNOON AND EVENING HOURS. WILL
PLACE A GOOD BIT OF WEIGHT FOR ITS PRECIPITATION SOLUTIONS INTO
THE EVENING. AS EXPECTED...THE FOCUS WILL BE ALONG AND JUST EAST
OF THE APPROACHING FRONT IN KY...AND ALSO ACROSS OUR NORTHERN
FRINGES NEAREST THE ONGOING SCATTERED ACTIVITY. HAVE ALSO
ADJUSTED TEMPERATURES THROUGH THE AFTERNOON. HAVE INCREASED HIGH
TEMPERATURES BY TWO OR THREE DEGREES FOR MOST AREAS.
AS OF 945 AM EDT WEDNESDAY...
NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. ONLY ISOLATED
SHOWERS NOTED ON RADAR AT THIS TIME...MOST JUST OUTSIDE THE
NORTHERN END OF THE FORECAST AREA. STILL ANTICIPATE ISOLATED TO
SCATTERED SHOWER DEVELOPMENT STARTING PRIMARILY IN THE EARLY
AFTERNOON. CANNOT RULE OUT A FEW BEFORE THAT TIME...BUT MOST WILL
FORM STARTING AROUND 200 PM AND ONWARD. ISOLATED THUNDERSTORMS
WILL BE POSSIBLE AS WELL.
AS OF 400 AM EDT WEDNESDAY...
ISOLATED SHOWERS DISSIPATED AS THEY MOVED SOUTHEAST OUR OF THE
FORECAST AREA BY 2AM THIS MORNING. MID AND HIGH CLOUDS WILL BE
MOVING INTO THE MOUNTAINS BY 8AM FROM THE OHIO VALLEY.
THE 500 MB TROF DEEPENS AND MOVES EAST TODAY AND TONIGHT. BY 12Z
THURSDAY THE TROF AXIS WILL BE JUST EAST OF THE FORECAST AREA. AT
THE SURFACE A COLD FRONT EXTENDED FROM DELAWARE TO MISSOURI. THIS
FRONT WILL MOVE SOUTH TODAY AND WILL CROSS THROUGH THE FORECAST
AREA TONIGHT. THERE IS DRIER AIR WELL NORTH OF THE BOUNDARY.
MODELS HAVE THIS DRYING PUSHING INTO THE FORECAST AREA AFTER
MIDNIGHT.
AHEAD OF THE FRONT THERE IS WEAK CONVERGENCE. BEST INSTABILITY
WILL BE THIS AFTERNOON AND EVENING...WITH CONVECTIVE AVAILABLE
POTENTIAL ENERGY AROUND 1000 J/KG. THE MORE SURFACE AND LOW LEVEL
WINDS BACK TO THE SOUTHWEST...THE BETTER THE CONVERGENCE WILL BE.
IF WINDS STAY WEST TO NORTHWEST...THE BULK OF THE PRECIPITATION
WILL BE LIMITED TO SOUTHEAST WEST VIRGINIA AND THE TYPICAL WESTERN
UPSLOPE AREAS.
THE REGION DOES GET INTO BETTER UPPER DIFFLUENCE TONIGHT...ALONG
WITH SOME DECENT Q-VECTOR FORCING. SO HAVE SLIGHTLY INCREASED THE
PROBABILITY OF PRECIPITATION DURING THE EVENING IN THE NORTHERN
AD WESTERN COUNTY WARNING AREA.
MAXIMUM TEMPERATURES WILL BE SIMILAR TO TUESDAY. STAYED CLOSE TO
GUIDANCE FOR BOTH HIGHS TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM EDT WEDNESDAY...
FRONTAL BOUNDARY SHOULD PUSH TO SOUTH BY THURSDAY MORNING...WITH
UPPER TROUGH LIFTING OUT TO THE NORTHEAST. HIGH PRESSURE OVER THE
OHIO VALLEY WILL BUILD SOUTHEAST INTO OUR REGION. NAM...GFS AND
ECMWF ARE SHOWING DRIER AIR ADVECTING INTO OUR REGION THURSDAY. HIGH
TEMPERATURES THURSDAY AFTERNOON WILL BE SEASONAL WITH READINGS FROM
THE MID 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT.
KEPT ISOLATED POPS IN THE SOUTHWEST THURSDAY NIGHT AS SUGGESTED BY
GFS WITH THE SHORTWAVE TRAVELING EAST ACROSS THE AREA. LEANED
TOWARDS THE MILD ADJMAV FOR LOWS THURSDAY NIGHT ESPECIALLY ALONG THE
SOUTHERN BLUE RIDGE. IN GENERAL...LOWS WILL VARY FROM THE MID 50S IN
THE NORTHWEST MOUNTAINS TO THE MID 60S IN THE SOUTHERN PORTIONS OF
FORECAST AREA.
BOTH THE GFS AND ECMWF DEVELOP CONVECTION ALONG AND NORTH OF THE
FRONTAL BOUNDARY FROM THE LOWER MISSOURI VALLEY EAST TOWARD THE OHIO
VALLEY LATE THURSDAY NIGHT...THEN RIDE THE CONVECTION SOUTHEAST INTO
THE MOUNTAINS BY MIDDAY FRIDAY. RAIN SPREADS EAST FRIDAY AFTERNOON
INTO FRIDAY NIGHT. WITH CLOUD COVER AND PRECIPITATION...PLAYED HIGH
TEMPERATURES CLOSER TO THE ADJMAV WITH VALUES FROM LOWER 70S IN THE
WEST TO THE MID 80S IN THE EAST. LOW TEMPERATURES FRIDAY NIGHT WILL
GENERALLY BE FROM AROUND 60 DEGREES TO THE MID 60S.
1021MB SFC HIGH PRESSURE OFF THE MID ATL COAST AND A WEDGE RIDGING
PATTERN WILL CONTINUE THE UNSETTLED WEATHER SATURDAY. A FRONTAL
BOUNDARY WITH WAVES OF LOW PRESSURE WILL REMAIN JUST TO OUR SOUTH
INTO THE WEEKEND. INCREASED POPS FOR SATURDAY AND SATURDAY NIGHT.
LOWERED HIGH TEMPERATURES SATURDAY WITH CONVECTION AND CLOUD
COVER...HIGHS WILL STRUGGLE INTO THE UPPER 60S IN THE MOUNTAINS TO
THE LOWER 70S IN THE PIEDMONT. WENT WITH HPCGUIDE MILDER LOW
TEMPERATURES FOR SATURDAY NIGHT IN TO SUNDAY MORNING...MAINLY IN THE
UPPER 50S AND LOWER 60S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 320 AM EDT WEDNESDAY...
OVERALL THIS PERIOD CHARACTERIZED BY WAVY FRONT SOUTH OF US ALONG
WITH SEVERAL EMBEDDED SHORTWAVES AND SFC LOWS RIDING ALONG IT. SFC
HIGH WILL BE OVER THE MID ATLANTIC/NORTHEAST WEDGING SW...AND WITH
CLOUD COVER...TEMPS SUNDAY WILL BE COOLER THAN NORMAL DURING THE DAY
AND CLOSER TO NORMAL AT NIGHT. STILL OVERALL LOOKS LIKE OFF AND ON
CHANCES OF SHOWERS AND SOME STORMS GIVEN THAT THE FRONT WILL BE
SOUTH OF US WITH LIMITED INSTABILITY. KEPT POPS GENERALLY HIGHER IN
THE DAYTIME AND OVER THE SRN CWA. HIGHS SUN WILL BE IN THE 70S MOST
LOCATIONS.
BY EARLY NEXT WEEK...THE MAIN SFC LOW SHIFTS OFF THE SC COAST WHILE
THE SFC HIGH BUILD SE OFF THE MID ATLANTIC COAST...WITH RAIN CHANCES
DECREASING...BUT GIVEN STILL RUN TO RUN INCONSISTENCY WILL BE
KEEPING AT LEAST CHANCE POPS IN FOR BOTH MON-TUE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 130 PM EDT WEDNESDAY...
LOW PRESSURE WAS LOCATED OVER SOUTHERN OHIO. THIS LOW WAS SITUATED
ALONG A COLD FRONT THAT EXTENDED SOUTHWEST OF THE LOW THROUGH
EASTERN KENTUCKY...AND EAST OF THE LOW THROUGH NORTHERN VIRGINIA.
THIS AFTERNOON AND EVENING THE LOW WILL PROGRESS EASTWARD WHILE
ITS TRAILING KY COLD FRONT MOVES INTO AND THROUGH THE AREA. WE
EXPECT SHOWERS AND STORMS TO DEVELOP TO HAVE ISOLATED TO SCATTERED
COVERAGE ACROSS THE MOUNTAINS WITH ISOLATED COVERAGE EAST OF THE
CREST OF THE BLUE RIDGE. THROUGH THE EARLY EVENING...MOST OF THE
ACTIVITY WILL WANE AND GRADUALLY DRIFT EASTWARD WITH BOTH THE
PREVAILING LOW LEVEL FLOW AND PROGRESSION OF THE FRONT. OTHER
THAN FOR SOME BRIEF PERIODS UNDER SOME OF THE HEAVIER CELLS...VFR
CONDITIONS ARE EXPECTED.
DRIER AIR WILL START ENTERING THE REGION LATER TONIGHT IN THE
WAKE OF THE FRONT AND WITH THE ARRIVAL OF SURFACE HIGH PRESSURE.
MAINLY VFR CONDITIONS ARE EXPECTED THROUGH THE NIGHT SAVE MOUNTAIN
AND RIVER VALLEY PATCHY FOG. ENOUGH RESIDUAL LOW LEVEL MOISTURE
MAY GET TRAPPED UNDER THE INVERSION AND LIFTED UPSLOPE IN THE WEST
FOR A BRIEF PERIOD OF MVFR CIGS BETWEEN KBLF-KLWB. ANY SUB-VFR
CONDITIONS WILL QUICKLY IMPROVE TO VFR AROUND 12-13Z/8-9AM
THURSDAY.
EXTENDED AVIATION DISCUSSION...
LENGTHY PERIOD OF SUB-VFR CONDITIONS POSSIBLE FRIDAY INTO SATURDAY
AS THE FRONT BUCKLES NORTH AGAIN WITH THE APPROACH AND PASSAGE OF
AN AREA OF LOW PRESSURE. GOOD POTENTIAL FOR PLENTY OF RAIN...LOW
CLOUDS AND REDUCED VISIBILITIES.
SUNDAY INTO MONDAY...COLD AIR DAMMING WEDGE IN PLACE ACROSS THE
EAST WITH POTENTIAL FOR CONTINUATION OF SUB-VFR CATEGORY
CONDITIONS. MODELS VARY ON THE EXTENT ANOTHER UPPER LOW WILL
SPREAD ADDITIONAL PRECIPITATION INTO AT LEAST THE WESTERN PARTS OF
THE AREA BY MONDAY...POSSIBLY CONVECTIVE OUTSIDE THE INFLUENCE OF
THE WEDGE.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/DS
NEAR TERM...AMS/DS
SHORT TERM...KK
LONG TERM...WP
AVIATION...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
102 PM EDT WED AUG 6 2014
.SYNOPSIS...
A COLD FRONT EXTENDED FROM MAINE TO DELAWARE TO NEW JERSEY THIS
MORNING. THIS FRONT WILL MOVE SOUTH THROUGH THE REGION
TONIGHT...REACHING THE GULF STATES BY LATE THURSDAY. A SERIES OF LOW
PRESSURE SYSTEMS WILL MOVE ALONG THE BOUNDARY FRIDAY THROUGH
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 150 PM EDT WEDNESDAY...
A SURFACE COLD FRONT IS STILL WEST OF THE REGION...BUT APPROACHING
THROUGH EASTERN KENTUCKY. AN AREA OF LOW PRESSURE WAS ALONG THE
FRONT ACROSS SOUTHERN OHIO...AND THEN THE FRONT EXTENDED EASTWARD
INTO NORTHERN VIRGINIA. A SMALL CLUSTER OF SHOWERS HAS BEEN
RIDGING ALONG THE BOUNDARY IN VIRGINIA...WITH MOST OF THE ACTIVITY
NORTH OF THE FORECAST REGION. HRRR AND RNK WRF-ARW GUIDANCE HAS
BEEN VERY WELL THE PAST FEW DAYS IN NARROWING DOWN THE PREFERRED
AREAS OF CONVECTION DURING THE AFTERNOON AND EVENING HOURS. WILL
PLACE A GOOD BIT OF WEIGHT FOR ITS PRECIPITATION SOLUTIONS INTO
THE EVENING. AS EXPECTED...THE FOCUS WILL BE ALONG AND JUST EAST
OF THE APPROACHING FRONT IN KY...AND ALSO ACROSS OUR NORTHERN
FRINGES NEAREST THE ONGOING SCATTERED ACTIVITY. HAVE ALSO
ADJUSTED TEMPERATURES THROUGH THE AFTERNOON. HAVE INCREASED HIGH
TEMPERATURES BY TWO OR THREE DEGREES FOR MOST AREAS.
AS OF 945 AM EDT WEDNESDAY...
NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. ONLY ISOLATED
SHOWERS NOTED ON RADAR AT THIS TIME...MOST JUST OUTSIDE THE
NORTHERN END OF THE FORECAST AREA. STILL ANTICIPATE ISOLATED TO
SCATTERED SHOWER DEVELOPMENT STARTING PRIMARILY IN THE EARLY
AFTERNOON. CANNOT RULE OUT A FEW BEFORE THAT TIME...BUT MOST WILL
FORM STARTING AROUND 200 PM AND ONWARD. ISOLATED THUNDERSTORMS
WILL BE POSSIBLE AS WELL.
AS OF 400 AM EDT WEDNESDAY...
ISOLATED SHOWERS DISSIPATED AS THEY MOVED SOUTHEAST OUR OF THE
FORECAST AREA BY 2AM THIS MORNING. MID AND HIGH CLOUDS WILL BE
MOVING INTO THE MOUNTAINS BY 8AM FROM THE OHIO VALLEY.
THE 500 MB TROF DEEPENS AND MOVES EAST TODAY AND TONIGHT. BY 12Z
THURSDAY THE TROF AXIS WILL BE JUST EAST OF THE FORECAST AREA. AT
THE SURFACE A COLD FRONT EXTENDED FROM DELAWARE TO MISSOURI. THIS
FRONT WILL MOVE SOUTH TODAY AND WILL CROSS THROUGH THE FORECAST
AREA TONIGHT. THERE IS DRIER AIR WELL NORTH OF THE BOUNDARY.
MODELS HAVE THIS DRYING PUSHING INTO THE FORECAST AREA AFTER
MIDNIGHT.
AHEAD OF THE FRONT THERE IS WEAK CONVERGENCE. BEST INSTABILITY
WILL BE THIS AFTERNOON AND EVENING...WITH CONVECTIVE AVAILABLE
POTENTIAL ENERGY AROUND 1000 J/KG. THE MORE SURFACE AND LOW LEVEL
WINDS BACK TO THE SOUTHWEST...THE BETTER THE CONVERGENCE WILL BE.
IF WINDS STAY WEST TO NORTHWEST...THE BULK OF THE PRECIPITATION
WILL BE LIMITED TO SOUTHEAST WEST VIRGINIA AND THE TYPICAL WESTERN
UPSLOPE AREAS.
THE REGION DOES GET INTO BETTER UPPER DIFFLUENCE TONIGHT...ALONG
WITH SOME DECENT Q-VECTOR FORCING. SO HAVE SLIGHTLY INCREASED THE
PROBABILITY OF PRECIPITATION DURING THE EVENING IN THE NORTHERN
AD WESTERN COUNTY WARNING AREA.
MAXIMUM TEMPERATURES WILL BE SIMILAR TO TUESDAY. STAYED CLOSE TO
GUIDANCE FOR BOTH HIGHS TODAY AND LOWS TONIGHT.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM EDT WEDNESDAY...
FRONTAL BOUNDARY SHOULD PUSH TO SOUTH BY THURSDAY MORNING...WITH
UPPER TROUGH LIFTING OUT TO THE NORTHEAST. HIGH PRESSURE OVER THE
OHIO VALLEY WILL BUILD SOUTHEAST INTO OUR REGION. NAM...GFS AND
ECMWF ARE SHOWING DRIER AIR ADVECTING INTO OUR REGION THURSDAY. HIGH
TEMPERATURES THURSDAY AFTERNOON WILL BE SEASONAL WITH READINGS FROM
THE MID 70S IN THE MOUNTAINS TO THE MID 80S IN THE PIEDMONT.
KEPT ISOLATED POPS IN THE SOUTHWEST THURSDAY NIGHT AS SUGGESTED BY
GFS WITH THE SHORTWAVE TRAVELING EAST ACROSS THE AREA. LEANED
TOWARDS THE MILD ADJMAV FOR LOWS THURSDAY NIGHT ESPECIALLY ALONG THE
SOUTHERN BLUE RIDGE. IN GENERAL...LOWS WILL VARY FROM THE MID 50S IN
THE NORTHWEST MOUNTAINS TO THE MID 60S IN THE SOUTHERN PORTIONS OF
FORECAST AREA.
BOTH THE GFS AND ECMWF DEVELOP CONVECTION ALONG AND NORTH OF THE
FRONTAL BOUNDARY FROM THE LOWER MISSOURI VALLEY EAST TOWARD THE OHIO
VALLEY LATE THURSDAY NIGHT...THEN RIDE THE CONVECTION SOUTHEAST INTO
THE MOUNTAINS BY MIDDAY FRIDAY. RAIN SPREADS EAST FRIDAY AFTERNOON
INTO FRIDAY NIGHT. WITH CLOUD COVER AND PRECIPITATION...PLAYED HIGH
TEMPERATURES CLOSER TO THE ADJMAV WITH VALUES FROM LOWER 70S IN THE
WEST TO THE MID 80S IN THE EAST. LOW TEMPERATURES FRIDAY NIGHT WILL
GENERALLY BE FROM AROUND 60 DEGREES TO THE MID 60S.
1021MB SFC HIGH PRESSURE OFF THE MID ATL COAST AND A WEDGE RIDGING
PATTERN WILL CONTINUE THE UNSETTLED WEATHER SATURDAY. A FRONTAL
BOUNDARY WITH WAVES OF LOW PRESSURE WILL REMAIN JUST TO OUR SOUTH
INTO THE WEEKEND. INCREASED POPS FOR SATURDAY AND SATURDAY NIGHT.
LOWERED HIGH TEMPERATURES SATURDAY WITH CONVECTION AND CLOUD
COVER...HIGHS WILL STRUGGLE INTO THE UPPER 60S IN THE MOUNTAINS TO
THE LOWER 70S IN THE PIEDMONT. WENT WITH HPCGUIDE MILDER LOW
TEMPERATURES FOR SATURDAY NIGHT IN TO SUNDAY MORNING...MAINLY IN THE
UPPER 50S AND LOWER 60S.
&&
.LONG TERM /SUNDAY THROUGH TUESDAY/...
AS OF 320 AM EDT WEDNESDAY...
OVERALL THIS PERIOD CHARACTERIZED BY WAVY FRONT SOUTH OF US ALONG
WITH SEVERAL EMBEDDED SHORTWAVES AND SFC LOWS RIDING ALONG IT. SFC
HIGH WILL BE OVER THE MID ATLANTIC/NORTHEAST WEDGING SW...AND WITH
CLOUD COVER...TEMPS SUNDAY WILL BE COOLER THAN NORMAL DURING THE DAY
AND CLOSER TO NORMAL AT NIGHT. STILL OVERALL LOOKS LIKE OFF AND ON
CHANCES OF SHOWERS AND SOME STORMS GIVEN THAT THE FRONT WILL BE
SOUTH OF US WITH LIMITED INSTABILITY. KEPT POPS GENERALLY HIGHER IN
THE DAYTIME AND OVER THE SRN CWA. HIGHS SUN WILL BE IN THE 70S MOST
LOCATIONS.
BY EARLY NEXT WEEK...THE MAIN SFC LOW SHIFTS OFF THE SC COAST WHILE
THE SFC HIGH BUILD SE OFF THE MID ATLANTIC COAST...WITH RAIN CHANCES
DECREASING...BUT GIVEN STILL RUN TO RUN INCONSISTENCY WILL BE
KEEPING AT LEAST CHANCE POPS IN FOR BOTH MON-TUE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 730 AM EDT WEDNESDAY...
PATCHY IFR TO MVFR FOG WILL DISSIPATE THIS MORNING BY 14Z/10AM.
THEN CEILINGS AND VISIBILITIES WILL BE VFR FOR THE REST OF THE
DAY.
A SHORT WAVE COMING OUT OF THE TENNESSEE VALLEY EARLY THIS MORNING
WILL BRING SOME MID AND HIGH CLOUD TO THE MOUNTAINS.
SHOWER AND THUNDERSTORMS WILL AGAIN IN MOUNTAINS THIS AFTERNOON...WITH
THE APPROACH OF A COLD FRONT...BUT COVERAGE STILL NOT GREAT ENOUGH
TO INCLUDE IN THE TAFS. WINDS WILL BE STRONGER... BUT NOT LIKELY
EXCEEDING 12 KNOTS SUSTAINED.
EXTENDED AVIATION DISCUSSION...
THE COLD FRONT WILL CROSS THE REGION ON THURSDAY...WITH LIMITED
PRECIPITATION ASSOCIATED WITH IT. HIGH PRESSURE WILL WORK ITS WAY
INTO THE AREA BY THURSDAY AFTERNOON.
A WAVE ON THE COLD FRONT WILL HELP LIFT IT BACK NORTH THROUGH THE
REGION FRIDAY INTO SATURDAY AS A WARM FRONT. IT WILL BE THIS
PERIOD IN THE FORECAST WITH THE BEST CHANCES OF SUB-VFR CONDITIONS
ACROSS A GENEROUS PART OF THE FORECAST AREA. DEPENDING UPON HOW
QUICKLY THE WAVE EXITS THE REGION...THESE CONDITIONS COULD LINGER
INTO SUNDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/DS
SHORT TERM...KK
LONG TERM...WP
AVIATION...AMS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 PM CDT WED AUG 6 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 245 PM CDT WED AUG 6 2014
NON-DISCREET FLOW WILL KEEP THINGS RELATIVELY QUIET WELL INTO THE
LONG TERM SO MAIN FOCUS IS ANY RAIN CHANCES ALONG MAINLY WESTERN AND
SOUTHERN TIERS THROUGH REMAINDER OF WEEK.
AREA REMAINS SOMEWHAT SANDWICHED BETWEEN STRONGER NORTHWEST FLOW TO
THE EAST...WEAK SHORT WAVE TROUGHS ACROSS CENTRAL PLAINS AND
EMBEDDED IN WESTERLIES ACROSS SOUTHERN CANADA. WITH SLOW EVOLVEMENT
IN ANY PATTERN CHANGES...HIGH PRESSURE OVER ONTARIO AND WESTERN
GREAT LAKES WILL KEEP FRONTAL BOUNDARY...WHERE PRECIPITATION IS
FOCUSED...SOUTH OF AREA. DRIER AIR KEEPING RAIN JUST SOUTHWEST OF
AREA WITH COOLER TEMPERATURES WHERE CLOUDS ARE THICKEST AND SEASONAL
CONDITIONS FURTHER NORTH/EAST.
NOT MUCH CHANGE IS EXPECTED TONIGHT AND THURSDAY. SUBTLE DIFFERENCES
IN SHORT TERM MODELS BUT SHORT WAVE ENERGY WILL KEEP THINGS MOST
ACTIVE ALONG FRONTAL BOUNDARY. GIVEN PERSISTENCE...HAVE LOWERED
OVERALL RAIN THREAT ALONG SOUTHWEST SERVICE AREA BORDER IN ALIGNMENT
WITH SURROUNDING FORECAST OFFICES AND CONTINUED CUT BACK IN
TEMPERATURES WHERE CLOUD COVER WILL BE MOST IN PLACE.
GIVEN WEAK FLOW AND MOISTURE REBOUND EXPECTED THIS EVENING...COULD
SEE MORE PATCHY FOG TONIGHT...BETWEEN THICKER CLOUD COVER AND DRIER
AIR TO THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 245 PM CDT WED AUG 6 2014
SIMILAR SETUP THURSDAY NIGHT AND FRIDAY WITH RAIN THREAT PRIMARILY
TO THE SOUTHWEST/SOUTH OF SERVICE AREA. LARGER QUESTIONS ABOUND WITH
MEDIUM RANGE GUIDANCE OCCASIONALLY TRYING TO DEVELOP A WEAK CLOSED
UPPER LOW AS WAVE EJECTS OUT OF WESTERN STATES TOWARDS THE WEEKEND.
ECMWF HAS BEEN THE STEADY MODEL KEEPING A BROAD RIDGE WITH HIGH
PRESSURE LOCKED OVER GREAT LAKES UNTIL POSSIBLY LATE SUNDAY WHEN
WESTERLIES ACROSS CANADA TRY TO SWEEP A COLD FRONT IN. EVEN AS THAT
HAPPENS EARLY NEXT WEEK...LOTS OF UNCERTAINTIES ON HOW ACTIVE FRONT
WILL BE WITH SUCH WEAK CONVERGENCE ALONG IT. BOTTOM LINE IS RAIN
THREATS REMAIN LOW THROUGH TUESDAY OF NEXT WEEK AND MANY AREAS COULD
REMAIN COMPLETELY DRY THROUGH THAT POINT.
GUIDANCE IN FAIR AGREEMENT THAT FLOW BECOMES MORE ACTIVE BY MID PART
OF NEXT WEEK THOUGH WITH ZONAL OR SLIGHTLY SOUTHWEST FLOW COULD LEAD
TO WARM AIR/MOISTURE RETURN AND STORMS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 600 PM CDT WED AUG 6 2014
FORECAST CONCERNS CONTINUE TO FOCUS ON A FOG THREAT...SPECIFICALLY
IN THE RIVER VALLEYS...WITH A GREATER IMPACT AT KLSE AS A RESULT.
CURRENTLY...CONVECTION CONTINUES TO SPARK A REGION OF FRONTOGENETIC
FORCING ACROSS IA. THIS ACTIVITY WILL STAY SOUTH OF THE TAF
SITES...BUT SOME HIGH CLOUDS FROM THE CONVECTION WILL FILTER ACROSS
THE AREA. HOW THICK AND FAR DOWN IN THE ATMOSPHERE POTENTIAL CIGS
WILL/COULD GET WILL BE A LIMITING FACTOR FOR FOG. THE THICKER-LOWER
THE CLOUDS...THE LESS THE THREAT OF SIGNIFICANT REDUCTIONS IN VSBYS.
WINDS ARE GENERALLY LIGHT FROM THE EAST...WITH BUFKIT SOUNDINGS
POINTING TO THIS LIGHT WIND LAYER EXTENDING UPWARDS OF 4K FT THROUGH
AT LEAST 06Z. SOME STRONGER WINDS SUGGESTED TO DEVELOP JUST OFF THE
SFC BEFORE 12Z AT KLSE PER THE RAP AND NAM...WITH THE RAP BRINGING
THEM IN MORE QUICKLY. NORMALLY THIS IS A DETERRENT...BUT IF STRONG
ENOUGH INVERSION ALREADY IN PLACE...SUB 1SM VSBYS WOULD STILL BE
FAVORED. OVERCOMING THE T/TD SPREAD WILL BE MORE OF A CHALLENGE THAN
YESTERDAY...WITH DAYTIME MIXING RESULTING IN HIGH TEMPS AND LOWER
TDS. THE KLSE SPREAD AT 23Z WAS 24 F.
MVFR VSBYS STILL LOOK REASONABLE FOR KRST. WILL KEEP THE MVFR TRENDS
AT KLSE FOR NOW...BUT ADD SOME BCFG TO HINT AT THICKER FOG NEARBY.
IF TRENDS WILL BE MONITORED CLOSELY...AND IF T/TD SPREAD CRASHES
QUICKLY THIS EVENING...THE 1/4SM THREAT WOULD INCREASE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...SHEA
LONG TERM....SHEA
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1247 PM CDT WED AUG 6 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
WATER VAPOR IMAGERY AND RAP 500MB ANALYSIS SHOWING THE AREA UNDER A
GENERAL TROUGH ALOFT WITH RIDGING OVER THE CENTRAL AND NORTHERN
PLAINS. GOOD PLUME OF SUBTROPICAL MOISTURE SURGING NORTHWARD ACROSS
THE PLAINS WITH A WEAK SHORTWAVE TROUGH AND MID-LEVEL FRONTOGENESIS
FUELING A BAND OF SHOWERS/THUNDERSTORMS ACROSS EASTERN ND/NEB...INTO
WESTERN AND CENTRAL IA. CLOSER IN...THE ARX FORECAST AREA WAS MOSTLY
CLEAR EAST OF THE MISSISSIPPI WITH WEAK TO CALM SURFACE WIND. THIS
WAS ALLOWING SOME FOG TO SET UP ACROSS PORTIONS OF CENTRAL WI AND IN
THE MISSISSIPPI/WISCONSIN RIVER VALLEYS. TEMPERATURES EARLY THIS
MORNING RANGED FROM THE MIDDLE 50S TO THE LOWER 60S.
FOR TODAY...SURFACE HIGH PRESSURE WILL HOLD OVER THE GREAT LAKES
REGION AS A MID-LEVEL SHORTWAVE TROUGH BUDGES EASTWARD FROM THE
CENTRAL PLAINS INTO WESTERN IA. MODELS IN PRETTY GOOD AGREEMENT
SHOWING ASSOCIATED SHOWERS/ISOLATED THUNDER JUST NIPPING PARTS OF
NORTHEAST IA BY NOON. DURING THE AFTERNOON DRIER AIR OUTFLOW FROM
THE GREAT LAKES HIGH LOOKS TO HALT ANY FARTHER NORTHEAST PUSH OF
THIS SHOWER/ISOLATED THUNDER ACTIVITY. IN FACT...APPEARS SOME OF
THIS RAIN MAY RETREAT FARTHER SOUTHWEST AN MAYBE ENTIRELY OUT OF OUR
AREA. OTHERWISE...PLAN ON PARTLY SUNNY SKIES EAST OF THE MISSISSIPPI
RIVER WITH CLOUD COVER DOMINATING WEST OF THE RIVER. HIGHS TODAY
EXPECTED TO TOP OFF IN THE 70S.
FOR TONIGHT INTO THURSDAY...MODELS COMING IN CLOSER AGREEMENT WITH
FAIRLY VIGOROUS MID-LEVEL TROUGH DROPPING THROUGH THE DAKOTAS INTO
THE MID/UPPER MISSISSIPPI RIVER VALLEY REGION. NAM STILL SHOWING
STRONG 850-500MB FRONTOGENESIS WITH THIS WAVE MOVING ALONG AND SOUTH
OF I-90 MAINLY DURING THE DAY THURSDAY. THE GFS IS SLIGHTLY FASTER
WITH THE WAVE COMPARED TO THE NAM/ECMWF/GEM AND HAS WEAKER
FRONTOGENESIS FOCUSED MORE ACROSS IA/IL. SINCE GFS SEEMS TO BE THE
ODD MODEL OUT...RAISED POPS TO HONOR MORE THE GFS/ECMWF/GEM MORE
NORTHERN SOLUTIONS. BTW...NOT MUCH CAPE INVOLVED WITH THIS WAVE...SO
TAPERED THUNDER TO ISOLATED MENTION GIVEN FORCING SIGNAL.
WILL HAVE TO CONTINUE WATCHING THE EVOLUTION/RAIN POTENTIAL OF THIS
SYSTEM AS IT IS ALWAYS A BIT TRICKY GIVEN DRY LOWER LEVEL OUTFLOW
FROM GREAT LAKES HIGH PRESSURE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 330 AM CDT WED AUG 6 2014
FOR THURSDAY NIGHT INTO FRIDAY...NAM/ECMWF/GEM SHOW SOME LINGERING
DEFORMATION SHOWERS AND ISOLATED THUNDER FOCUSED MAINLY ALONG AND
SOUTH OF I-90. CARRIED LOWER-END POPS TO COVER THIS.
FRIDAY NIGHT THROUGH SATURDAY NIGHT LOOK DRY AS MIDDLE LEVEL RIDGE
DRIFTS OVERHEAD.
SHOWER/THUNDERSTORM CHANCES RETURN TO THE AREA SUNDAY LASTING
THROUGH TUESDAY AS A COLD FRONT MOVES THROUGH AND COOLER CYCLONIC
FLOW ALOFT LINGERS.
TEMPERATURES FRIDAY THROUGH THE PERIOD LOOK RIGHT AROUND NORMAL
LEVELS WITH DAYTIME READINGS IN THE UPPER 70S TO THE LOWER 80S AND
IN THE UPPER 50S/LOWER 60S AT NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1247 PM CDT WED AUG 6 2014
A FRONTAL BOUNDARY STALLED ACROSS IOWA WILL BE THE FOCUS FOR
SHOWERS AND ISOLATED THUNDERSTORMS. THIS ACTIVITY WILL REMAIN TO
THE SOUTH OF THE TAF SITES THROUGH THE FORECAST PERIOD. VALLEY FOG
COULD DEVELOP AT KLSE TONIGHT...DEPENDING ON IF A CLOUD DECK AT 5
KFT MOVES OVER THE MISSISSIPPI RIVER VALLEY LATE TONIGHT. IF THIS
CLOUD DECK DEVELOPS VALLEY FOG WOULD BE UNLIKELY. HAVE STARTED
TRENDING THE KLSE TAF TOWARD VALLEY FOG WITH THIS CLOUD DECK
LOOKING SUSPECT IN THE NAM FORECAST SOUNDINGS. WILL HAVE TO KEEP
A VERY CLOSE EYE ON CLOUD COVER TONIGHT. BR IS EXPECTED AT KRST
LATE TONIGHT WITH VISIBILITIES POSSIBLY DROPPING TO AROUND 5SM.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION...WETENKAMP