Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 08/04/13
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1000 PM MDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 959 PM MDT SAT AUG 3 2013
UPDATED FOR EXPIRATION OF SEVERE TSTM WATCH. ALSO TO REFLECT
CURRENT PCPN TRENDS. WILL LEAVE FLASH FLOOD WATCH IN PLACE FOR EL
PASO COUNTY BECAUSE SOME MODERATE TO HEAVY RAIN IS CONTINUING OVER
PORTIONS OF SOUTHERN/SOUTHEAST EL PASO COUNTY.
UPDATE ISSUED AT 900 PM MDT SAT AUG 3 2013
UPDATED TO CANCEL FLASH FLOOD WATCH FOR TELLER COUNTY/RAMPART
RANGE...TO CANCEL SEVERE TSTM WATCH FOR TELLER COUNTY/PIKES PEAK
AREA AS WELL. ALSO UPDATED TO REFLECT CURRENT PCPN TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...FLASH FLOODING THREAT FOR THE BURN SCARS AND SEVERE THUNDERSTORM
THREAT FOR THE SOUTHEAST PLAINS THROUGH THIS EVENING...
RICH LOW LEVEL MOISTURE IN PLACE ACROSS SOUTHEAST PLAINS AS OF EARLY
THIS AFTERNOON...WITH SFC DEW POINTS IN THE 60S. THIS IS BEING
ADVECTED IN BY LOW LEVEL EASTERLY FLOW. CLOUD COVER HAS HUNG IN
LONGER ACROSS THE PLAINS THIS AFTERNOON BUT IS ERODING ON WESTWARD
EDGE WHICH SHOULD ERODE CIN FROM WEST TO EAST AS THE AFTERNOON
PROGRESSES. MEANWHILE...MONSOON PLUME CONTINUES TO LAY ACROSS THE
REGION CAUGHT UP IN SOUTHWEST FLOW AROUND WEST SIDE OF SFC HIGH AND
SFC DEW POINT ACROSS THE MOUNTAINS ARE QUITE RESPECTABLE...IN THE
40S WITH SOME LOWER 30S ACROSS INTERIOR VALLEY OF LAKE/CHAFFEE
COUNTIES.
FOR THE REMAINDER OF THIS AFTERNOON AND EVENING...THUNDERSTORMS OVER
THE MOUNTAINS WILL SPREAD EASTWARD ACROSS THE ADJACENT PLAINS WITH
MODELS SUGGESTING ONE OR MORE THUNDERSTORM COMPLEXES TAKING SHAPE
AROUND 03Z BEFORE DROPPING TO THE SOUTHEAST INTO SOUTHWEST KS AND
TX/OK PANHANDLES TOWARDS MORNING. SPC MESO ANALYSIS AS OF 18Z
SHOWING 2000+ J/KG OF CAPE. 0-6KM SHEARS WILL BE RUNNING AROUND
30-35 KTS OF DEEP LAYER SHEAR. THUS...MULTICELL STORMS WILL PROBABLY
BE THE MAIN STORM THREAT...THOUGH COULD NOT RULE OUT AN ISOLATED
SUPERCELL ESPECIALLY WHERE LOW LEVEL EASTERLIES MAXIMIZE. THIS
WOULD MOST LIKELY OCCUR ACROSS NORTHERN SECTIONS OF THE FORECAST
AREA...PARTICULARLY KIOWA COUNTY.
OF POTENTIALLY EQUAL OR GREATER CONCERN WILL BE POTENTIAL FOR FLASH
FLOODING ON THE BURN SCARS...PARTICULARLY WALDO AND BLACK FOREST.
SOUTHEAST UPSLOPE FLOW COMBINED WITH HEATING...AND WEAK SHORTWAVE
ENERGY EMBEDDED IN MONSOON PLUME ALOFT SHOULD TRIGGER THUNDERSTORMS
OVER THE PIKES PEAK REGION THROUGH 2 PM...WITH A LINE OF
THUNDERSTORMS MOVING OFF TO THE EAST ACROSS THE WALDO AND BLACK
FOREST BURN SCARS BETWEEN 3 AND 6 PM. A MYRIAD OF SHORT RANGE HIGH
RES MODELS SHOW THIS...THOUGH WITH VARYING TIMING. OF COURSE...HAVE
SEEN THIS BEFORE IN THE MODELS AND HAD STORMS MIRACULOUSLY SPARE THE
BURN SCARS...BUT DEW POINTS SO HIGH (40S AND 50S) THREAT SHOULD BE
FAIRLY HIGH TODAY. FLASH FLOOD WATCH STILL LOOKS ON TRACK. THINK
THREAT SHOULD DIMINISH AFTER 8 PM...BUT HRRR OCCASIONALLY SHOWS
ANOTHER ROUND MOVING OFF AROUND 04Z SO WILL MAINTAIN THE MIDNIGHT
END TIME OF THE WATCH FOR NOW. FREQUENTLY THE HRRR OVERESTIMATES
THE INTENSITY OF ANY TRAILING ROUNDS OF CONVECTION.
THE WEST FORK BURN SCAR IS ALSO UNDER THE GUN TODAY FOR FLASH
FLOODING...THOUGH THREAT DOES NOT LOOK AS HIGH AS YESTERDAY. WITH
PRECIP WATERS RUNNING AROUND 150% OF NORMAL ACROSS THE WESTERN
PORTIONS OF CO...HEAVY RAIN WILL BE A THREAT WITH ANY THUNDERSTORMS
WHICH COULD CAUSE FLASH FLOODING SHOULD IT IMPACT THE WEST FORK BURN
SCAR. SO WILL BE MONITORING THIS REGION AS WELL.
OVERNIGHT...ACTIVITY SHOULD SHIFT EASTWARD AND EXIT THE AREA WITH
STRATUS SPREADING/DEVELOPING ACROSS SOUTHEAST COLORADO OVERNIGHT.
SUNDAY WILL BE HUMID AGAIN ACROSS THE SOUTHEAST PLAINS WITH DEW
POINTS IN THE 50S AND 60S IN THE MORNING AND MONSOON PLUME STILL
OVER THE REGION. MODELS SUGGEST LESS CONVECTION TOMORROW...AND EVEN
DRY SFC DEW POINTS ACROSS THE SOUTHEAST MTS A LITTLE IN THE
AFTERNOON STILL LOOKING AT CAPES AROUND 1500 J/KG ACROSS THE FAR
EAST PLAINS AND WITH MONSOON PLUME STILL OVERHEAD...AT LEAST THE
TYPICAL SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. BURN SCARS
WILL BE UNDER THE GUN AGAIN AS USUAL...BUT THREAT APPEARS A LITTLE
LOWER THAN TODAY...SO WILL NOT HOIST ANY WATCHES AT THIS TIME.
LATER SHIFTS CAN GET A LOOK AT THE LATEST RUNS AND REASSESS.
OTHERWISE...TEMPERATURES TOMORROW SHOULD SKEW SLIGHTLY WARMER THAN
THOSE OF TODAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...SEASONAL MONSOON WILL REMAIN IN PLACE THROUGH NEXT WEEK...
MOIST PATTERN WILL CONTINUE. SOUTHWEST MONSOON WILL CONTINUE TO
TAKE AIM AT SOUTHERN COLORADO THROUGH MOST OF NEXT WEEK.
ADDITIONALLY...A LARGE UPPER TROUGH OVER THE NORTHERN SOUTHERN
CANADA AND THE NORTHERN TIER OF THE US...WILL SEND SURFACE
BOUNDARIES SOUTH THROUGH THE CENTRAL PLAINS AT TIMES...BACKING
THE MOISTURE UP AGAINST THE MOUNTAINS. THIS PATTERN SHOULD KEEP
PLENTY OF LOW LEVEL MOISTURE IN PLACE ACROSS THE PLAINS AND EAST
SLOPES OF THE MOUNTAINS. ALSO...PERIODS OF ENHANCED UPSLOPE FLOW
BEHIND THE BOUNDARIES WILL HELP TO LIFT THE AIR AND SQUEEZE OUT THE
PRECIPITATION ON A MORE WIDESPREAD BASIS ACROSS THE AREA. SO...ALL
SEEMS IN PLACE FOR A RATHER WET PERIOD ACROSS SOUTHERN
COLORADO...WITH PERIODS OF HEAVY RAIN AND FLASH FLOODING POSSIBLE
EACH DAY OF NEXT WEEK. SPECIFICS OF THE FORECAST ARE DIFFICULT BUT
INDICATIONS ARE THAT WE COULD SEE CONVECTIVE COMPLEXES AFFECTING THE
PLAINS MONDAY AND TUESDAY NIGHTS...A MORE WIDESPREAD AREA OF
PRECIPITATION WEDNESDAY INTO THURSDAY...AND THEN MORE SCATTERED
PRECIPITATION AGAIN FRIDAY INTO SATURDAY. ALL OF THESE DETAILS
ARE SUBJECT TO CHANGE. STAY TUNED. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 249 PM MDT SAT AUG 3 2013
THUNDERSTORMS COULD AFFECT ALL THREE TAF SITES THROUGH THIS EVENING
WITH KCOS HAVING THE GREATEST RISK. WILL CARRY A TEMPO GROUP FROM
21Z TO 01Z TODAY FOR KCOS AND ADJUST AS NECESSARY BASED ON RADAR
TRENDS. KPUB AND KALS ALSO CARRY A THREAT FOR -TSRA BUT WILL
MAINTAIN VCTS FOR NOW UNTIL RADAR TRENDS BECOME MORE CLEAR. LOCAL
ERRATIC WIND GUSTS TO 40 KTS WILL BE POSSIBLE ALONG WITH MVFR
CIGS/VIS WITH TSRA. A SEVERE THUNDERSTORM RISK ALSO LIES ACROSS THE
SOUTHEAST PLAINS INCLUDING THE KCOS AND KPUB TAF SITES...BUT RISK AT
THIS POINT LOOKS TOO LOW TO MENTION GS OR GUSTS OVER 50 KTS IN THE
TAF. THIS TOO WILL BE MONITORED. KALS WILL SEE POTENTIAL FOR -TSRA
IN VCNTY AFTER 20Z. LOCALLY HEAVY RAIN WITH MVFR CIGS/VIS WITH
THUNDERSTORMS WILL BE A POSSIBILITY THERE AS WELL BUT WITH LESS OF A
SEVERE THUNDERSTORM POTENTIAL. EXPECT -TSRA THREAT TO DIMINISH AFTER 02Z
WITH KCOS AND KPUB SEEING MVFR TO IFR STRATUS MOVING IN AFTER 06Z.
THIS WILL PERSIST UNTIL 15-16Z...FOR KPUB...AND UNTIL AT LEAST 17Z
FOR KCOS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ084-085.
&&
$$
UPDATE...28
SHORT TERM...KT
LONG TERM...LW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
906 PM MDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 900 PM MDT SAT AUG 3 2013
UPDATED TO CANCEL FLASH FLOOD WATCH FOR TELLER COUNTY/RAMPART
RANGE...TO CANCEL SEVERE TSTM WATCH FOR TELLER COUNTY/PIKES PEAK
AREA AS WELL. ALSO UPDATED TO REFLECT CURRENT PCPN TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...FLASH FLOODING THREAT FOR THE BURN SCARS AND SEVERE THUNDERSTORM
THREAT FOR THE SOUTHEAST PLAINS THROUGH THIS EVENING...
RICH LOW LEVEL MOISTURE IN PLACE ACROSS SOUTHEAST PLAINS AS OF EARLY
THIS AFTERNOON...WITH SFC DEW POINTS IN THE 60S. THIS IS BEING
ADVECTED IN BY LOW LEVEL EASTERLY FLOW. CLOUD COVER HAS HUNG IN
LONGER ACROSS THE PLAINS THIS AFTERNOON BUT IS ERODING ON WESTWARD
EDGE WHICH SHOULD ERODE CIN FROM WEST TO EAST AS THE AFTERNOON
PROGRESSES. MEANWHILE...MONSOON PLUME CONTINUES TO LAY ACROSS THE
REGION CAUGHT UP IN SOUTHWEST FLOW AROUND WEST SIDE OF SFC HIGH AND
SFC DEW POINT ACROSS THE MOUNTAINS ARE QUITE RESPECTABLE...IN THE
40S WITH SOME LOWER 30S ACROSS INTERIOR VALLEY OF LAKE/CHAFFEE
COUNTIES.
FOR THE REMAINDER OF THIS AFTERNOON AND EVENING...THUNDERSTORMS OVER
THE MOUNTAINS WILL SPREAD EASTWARD ACROSS THE ADJACENT PLAINS WITH
MODELS SUGGESTING ONE OR MORE THUNDERSTORM COMPLEXES TAKING SHAPE
AROUND 03Z BEFORE DROPPING TO THE SOUTHEAST INTO SOUTHWEST KS AND
TX/OK PANHANDLES TOWARDS MORNING. SPC MESO ANALYSIS AS OF 18Z
SHOWING 2000+ J/KG OF CAPE. 0-6KM SHEARS WILL BE RUNNING AROUND
30-35 KTS OF DEEP LAYER SHEAR. THUS...MULTICELL STORMS WILL PROBABLY
BE THE MAIN STORM THREAT...THOUGH COULD NOT RULE OUT AN ISOLATED
SUPERCELL ESPECIALLY WHERE LOW LEVEL EASTERLIES MAXIMIZE. THIS
WOULD MOST LIKELY OCCUR ACROSS NORTHERN SECTIONS OF THE FORECAST
AREA...PARTICULARLY KIOWA COUNTY.
OF POTENTIALLY EQUAL OR GREATER CONCERN WILL BE POTENTIAL FOR FLASH
FLOODING ON THE BURN SCARS...PARTICULARLY WALDO AND BLACK FOREST.
SOUTHEAST UPSLOPE FLOW COMBINED WITH HEATING...AND WEAK SHORTWAVE
ENERGY EMBEDDED IN MONSOON PLUME ALOFT SHOULD TRIGGER THUNDERSTORMS
OVER THE PIKES PEAK REGION THROUGH 2 PM...WITH A LINE OF
THUNDERSTORMS MOVING OFF TO THE EAST ACROSS THE WALDO AND BLACK
FOREST BURN SCARS BETWEEN 3 AND 6 PM. A MYRIAD OF SHORT RANGE HIGH
RES MODELS SHOW THIS...THOUGH WITH VARYING TIMING. OF COURSE...HAVE
SEEN THIS BEFORE IN THE MODELS AND HAD STORMS MIRACULOUSLY SPARE THE
BURN SCARS...BUT DEW POINTS SO HIGH (40S AND 50S) THREAT SHOULD BE
FAIRLY HIGH TODAY. FLASH FLOOD WATCH STILL LOOKS ON TRACK. THINK
THREAT SHOULD DIMINISH AFTER 8 PM...BUT HRRR OCCASIONALLY SHOWS
ANOTHER ROUND MOVING OFF AROUND 04Z SO WILL MAINTAIN THE MIDNIGHT
END TIME OF THE WATCH FOR NOW. FREQUENTLY THE HRRR OVERESTIMATES
THE INTENSITY OF ANY TRAILING ROUNDS OF CONVECTION.
THE WEST FORK BURN SCAR IS ALSO UNDER THE GUN TODAY FOR FLASH
FLOODING...THOUGH THREAT DOES NOT LOOK AS HIGH AS YESTERDAY. WITH
PRECIP WATERS RUNNING AROUND 150% OF NORMAL ACROSS THE WESTERN
PORTIONS OF CO...HEAVY RAIN WILL BE A THREAT WITH ANY THUNDERSTORMS
WHICH COULD CAUSE FLASH FLOODING SHOULD IT IMPACT THE WEST FORK BURN
SCAR. SO WILL BE MONITORING THIS REGION AS WELL.
OVERNIGHT...ACTIVITY SHOULD SHIFT EASTWARD AND EXIT THE AREA WITH
STRATUS SPREADING/DEVELOPING ACROSS SOUTHEAST COLORADO OVERNIGHT.
SUNDAY WILL BE HUMID AGAIN ACROSS THE SOUTHEAST PLAINS WITH DEW
POINTS IN THE 50S AND 60S IN THE MORNING AND MONSOON PLUME STILL
OVER THE REGION. MODELS SUGGEST LESS CONVECTION TOMORROW...AND EVEN
DRY SFC DEW POINTS ACROSS THE SOUTHEAST MTS A LITTLE IN THE
AFTERNOON STILL LOOKING AT CAPES AROUND 1500 J/KG ACROSS THE FAR
EAST PLAINS AND WITH MONSOON PLUME STILL OVERHEAD...AT LEAST THE
TYPICAL SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. BURN SCARS
WILL BE UNDER THE GUN AGAIN AS USUAL...BUT THREAT APPEARS A LITTLE
LOWER THAN TODAY...SO WILL NOT HOIST ANY WATCHES AT THIS TIME.
LATER SHIFTS CAN GET A LOOK AT THE LATEST RUNS AND REASSESS.
OTHERWISE...TEMPERATURES TOMORROW SHOULD SKEW SLIGHTLY WARMER THAN
THOSE OF TODAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...SEASONAL MONSOON WILL REMAIN IN PLACE THROUGH NEXT WEEK...
MOIST PATTERN WILL CONTINUE. SOUTHWEST MONSOON WILL CONTINUE TO
TAKE AIM AT SOUTHERN COLORADO THROUGH MOST OF NEXT WEEK.
ADDITIONALLY...A LARGE UPPER TROUGH OVER THE NORTHERN SOUTHERN
CANADA AND THE NORTHERN TIER OF THE US...WILL SEND SURFACE
BOUNDARIES SOUTH THROUGH THE CENTRAL PLAINS AT TIMES...BACKING
THE MOISTURE UP AGAINST THE MOUNTAINS. THIS PATTERN SHOULD KEEP
PLENTY OF LOW LEVEL MOISTURE IN PLACE ACROSS THE PLAINS AND EAST
SLOPES OF THE MOUNTAINS. ALSO...PERIODS OF ENHANCED UPSLOPE FLOW
BEHIND THE BOUNDARIES WILL HELP TO LIFT THE AIR AND SQUEEZE OUT THE
PRECIPITATION ON A MORE WIDESPREAD BASIS ACROSS THE AREA. SO...ALL
SEEMS IN PLACE FOR A RATHER WET PERIOD ACROSS SOUTHERN
COLORADO...WITH PERIODS OF HEAVY RAIN AND FLASH FLOODING POSSIBLE
EACH DAY OF NEXT WEEK. SPECIFICS OF THE FORECAST ARE DIFFICULT BUT
INDICATIONS ARE THAT WE COULD SEE CONVECTIVE COMPLEXES AFFECTING THE
PLAINS MONDAY AND TUESDAY NIGHTS...A MORE WIDESPREAD AREA OF
PRECIPITATION WEDNESDAY INTO THURSDAY...AND THEN MORE SCATTERED
PRECIPITATION AGAIN FRIDAY INTO SATURDAY. ALL OF THESE DETAILS
ARE SUBJECT TO CHANGE. STAY TUNED. LW
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 249 PM MDT SAT AUG 3 2013
THUNDERSTORMS COULD AFFECT ALL THREE TAF SITES THROUGH THIS EVENING
WITH KCOS HAVING THE GREATEST RISK. WILL CARRY A TEMPO GROUP FROM
21Z TO 01Z TODAY FOR KCOS AND ADJUST AS NECESSARY BASED ON RADAR
TRENDS. KPUB AND KALS ALSO CARRY A THREAT FOR -TSRA BUT WILL
MAINTAIN VCTS FOR NOW UNTIL RADAR TRENDS BECOME MORE CLEAR. LOCAL
ERRATIC WIND GUSTS TO 40 KTS WILL BE POSSIBLE ALONG WITH MVFR
CIGS/VIS WITH TSRA. A SEVERE THUNDERSTORM RISK ALSO LIES ACROSS THE
SOUTHEAST PLAINS INCLUDING THE KCOS AND KPUB TAF SITES...BUT RISK AT
THIS POINT LOOKS TOO LOW TO MENTION GS OR GUSTS OVER 50 KTS IN THE
TAF. THIS TOO WILL BE MONITORED. KALS WILL SEE POTENTIAL FOR -TSRA
IN VCNTY AFTER 20Z. LOCALLY HEAVY RAIN WITH MVFR CIGS/VIS WITH
THUNDERSTORMS WILL BE A POSSIBILITY THERE AS WELL BUT WITH LESS OF A
SEVERE THUNDERSTORM POTENTIAL. EXPECT -TSRA THREAT TO DIMINISH AFTER 02Z
WITH KCOS AND KPUB SEEING MVFR TO IFR STRATUS MOVING IN AFTER 06Z.
THIS WILL PERSIST UNTIL 15-16Z...FOR KPUB...AND UNTIL AT LEAST 17Z
FOR KCOS. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ084-085.
&&
$$
UPDATE...28
SHORT TERM...KT
LONG TERM...LW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
316 PM MDT FRI AUG 2 2013
.SHORT TERM...AS EXPECTED...THE COLD FRONT OUT OF NE/SD HAS MOVED
INTO NORTHEASTERN COLORADO ALREADY...PUSHED QUICKER BY LAST NIGHT
AND THIS MORNINGS CONVECTION UP THERE. THIS IS ABOUT 12 HOURS
AHEAD OF WHAT THE GFS...ECMWF...NAM AND GEM MODELS HAD IT COMING
IN....THE HRRR AND THE RUC MODELS HAVE BEEN SHOWING AN EARLIER
ARRIVAL WITH EACH HOURLY RUN. HAVE ADJUSTED WIND AND WEATHER
GRIDS FOR AN EARLIER ARRIVAL.
A BUILDING UPPER RIDGE CONTINUES TO STRETCH FROM TEXAS NORTHWEST
INTO MONTANA TONIGHT INTO SATURDAY. HIGH SURFACE PRESSURE OVER THE
HIGH NORTHERN PLAINS WILL CONTINUE MOVING SOUTH AND PUSH THE COLD
FRONT FURTHER SOUTH DOWN THE EASTERN PLAINS OF COLORADO. FRONTAL
LIFT WILL CONTINUE PRODUCING ISOLATED SHOWERS AND THUNDERSTORMS
OVER THE PLAINS THROUGH TONIGHT WITH OROGRAPHIC LIFT KEEPING
ISOLATED STORMS GOING OVER THE HIGHER TERRAIN THROUGH THE
EVENING.
HIGHER MOISTURE WILL BE PUSHED IN FROM THE EAST THROUGH
SATURDAY...WITH PRECIPITABLE WATER CURRENTLY AROUND 0.7 INCHES AND
FORECASTED TO INCREASE TO NEAR 1.5 INCHES BY SATURDAY AFTERNOON.
THIS WILL HELP INCREASE CAPES UP TO NEAR 1500 J/KG OVER THE
PLAINS...THEN EASTERLY FLOW AT THE SURFACE TRANSITIONING TO
INCREASING SOUTHERLIES NEAR 700 MB THEN WESTERLIES NEAR 500 MB
WILL PROVIDE ENOUGH SHEAR FOR MAKING THE ENVIRONMENT ABLE TO
PRODUCE AND CARRY STRONGER STORMS. TEMPERATURES WILL BE COOLER AT
THE SURFACE OVER THE FOOTHILLS AND PLAINS TOMORROW WITH LOW 80S
EXPECTED. MOUNTAINS SHOULD STAY ABOVE THIS FRONTAL AIRMASS WITH
SIMILAR TEMPERATURES TO TODAY AND ISOLATED TO SCATTERED
CONVECTION. AREAS ALONG AND EAST OF THE CONTINENTAL DIVIDE WILL
SEE MORE WIDESPREAD SHOWERS AND STORMS WITH THE UPSLOPE FLOW.
RAINFALL AMOUNTS ARE EXPECTED TO BE GREATER WITH THE STRONG STORMS
WHERE A SINGLE STORM COULD PRODUCE HALF AN INCH OR MORE. THESE
STORMS WILL ALSO HAVE THE THREAT OF STRONG WINDS AND LARGE HAIL
UNDER TOMORROWS EXPECTED ENVIRONMENT. NAM MODEL IS AN OUTLIER
WITH THE FRONT AND SURFACE TROUGH MOVING BACK EAST INTO THE PLAINS
WHICH WOULD DRASTICALLY LOWER THE CHANCE OF PRECIPITATION ALONG
THE FOOTHILLS AND METRO AREAS. WITH THIS MODEL BEING THE ONLY ONE
SHOWING THIS PATTERN....WILL DISCOUNT FOR NOW...BUT NOT TOTALLY
DISREGARD THE POSSIBILITY.
.LONG TERM...MID LEVEL SHORTWAVE TO MOVE ACROSS FAR EASTERN PLAINS
SATURDAY EVENING. BEST CHANCE FOR STORMS DURING THE EVENING TO
BE ALONG AND AHEAD OF THE WAVE ACROSS FAR EASTERN PLAINS AND WILL
KEEP THE HIGHER POPS THERE. CAPE VALUES TO DECREASE DURING THE
EVENING TO LESS THAN 1000 J/KG...SO ANY THREAT FOR SEVERE STORMS
SHOULD HAVE ENDED. STILL POTENTIAL FOR STORMS TO PRODUCE BRIEF
HEAVY RAINFALL...ESPECIALLY FAR EASTERN PLAINS AND ALONG
FOOTHILLS. STORMS TO END OVERNIGHT WITH SOME CLEARING. BOUNDARY
LAYER WIND AND HUMIDITY PROGS SUGGEST SOME POTENTIAL FOR FOG OVER
THE FAR NORTHEAST CORNER TOWARDS MORNING. FOR NOW WILL HOLD OFF ON
ADDING ANY FOG. ON SUNDAY...FLOW ALOFT BECOMES A BIT MORE WESTERLY
WITH A SLIGHT DECREASE IN MOISTURE. PRECIPITABLE WATER VALUES
STILL FAIRLY HIGH ACROSS PLAINS WITH VALUES ABOVE AN INCH. STILL
BEST CHANCE FOR STORMS TO BE ACROSS MOUNTAINS AND FOOTHILLS AS
WELL AS ALONG THE PALMER DIVIDE DURING THE AFTERNOON AND EVENING
AS FORECAST SOUNDINGS SHOWING A MID LEVEL CAP OVER MUCH OF THE
PLAINS. THERE ARE SOME HINTS OF THE DEVELOPMENT OF A DENVER
CYCLONE WHICH COULD FOCUS ADDITIONAL STORM DEVELOPMENT EAST OF THE
URBAN CORRIDOR. TEMPERATURES TO BE A FEW DEGREES WARMER...CLOSER
TO NORMAL READINGS. FOR MONDAY...MODELS SHOW WESTERLY FLOW ALOFT
INCREASING WITH UPPER HIGH CENTERED OVER NORTHERN TEXAS. AIRMASS A
BIT DRIER...WITH PRECIPITABLE WATER VALUES AROUND NINE TENTHS OF
AN INCH ACROSS THE PLAINS AND SIX TENTHS OF AN INCH OVER THE
MOUNTAINS. STILL ENOUGH MOISTURE OF A SLIGHT CHANCE OF AFTERNOON
AND EVENING THUNDERSTORMS....MAINLY OVER THE MOUNTAINS. HIGHS TO
BE NEAR NORMAL. ON TUESDAY...CENTER OF UPPER HIGH SHIFTS INTO
EASTERN TEXAS WITH FLOW BECOMING SOUTHWEST. SOME INCREASE IN
SUBTROPICAL MOISTURE DURING THE AFTERNOON...MAINLY ACROSS
MOUNTAINS. BEST CHANCE FOR STORMS TO BE OVER THE HIGH COUNTRY.
HIGHS TO HOVER NEAR NORMAL.
FOR THE LATER DAYS...WEDNESDAY THROUGH FRIDAY: SOUTHWEST FLOW
ALOFT TO PREVAIL WITH UPPER HIGH SHIFTING INTO ARKANSAS BY FRIDAY.
SUBTROPICAL MOISTURE TO INCREASE WEDNESDAY AND THURSDAY WITH A
BETTER CHANCE FOR THUNDERSTORMS. IN ADDITION...MODELS SHOW A FRONT
MOVING ACROSS THE PLAINS WEDNESDAY...INCREASING THE UPSLOPE AND
LOW LEVEL MOISTURE. BY FRIDAY THERE IS SOME HINTS AT THE MOISTURE
DECREASING WITH A MORE STABLE AIRMASS WHICH SHOULD LEAD TO A LOWER
CHANCE FOR THUNDERSTORMS. TEMPERATURES TO COOL TO BELOW NORMAL BY
FRIDAY.
&&
.AVIATION...VFR CONDITIONS WILL PREVAIL TODAY WITH LIGHT WINDS.
A SLIGHT CHANCE AT SEEING A THUNDERSTORM LATE THIS AFTERNOON AND
EVENING WITH THE BEST CHANCE OVER THE HIGH TERRAIN AND NEAR THE WY
BORDER. GOOD POSSIBILITY OF OUTFLOW AT THE AREA AIRPORTS FROM
STORMS...REASON FOR VRB20G30KT. A COLD FRONT WILL BE MOVING SOUTH
ACROSS THE AREA TONIGHT WHICH WILL BRING IN HIGHER MOISTURE AND
UPSLOPE FLOW. MUCH MORE WIDESPREAD CONVECTION EXPECTED SATURDAY.
&&
.HYDROLOGY...AIRMASS IS DRIER AND MORE STABLE TODAY LEAVING
ISOLATED COVERAGE OF THUNDERSTORMS THIS AFTERNOON AND EVENING.
MODERATE TO A VERY BRIEF PERIOD OF HEAVY RAIN WILL BE POSSIBLE
FROM THE STORMS THAT DO DEVELOP...UP TO A THIRD OF AN INCH FROM A
STRONG STORM. MOISTURE WILL INCREASE BEHIND A FRONT TONIGHT AND
BRING A GOOD CHANCE FOR STORMS SATURDAY. THESE STORMS WILL BE
CAPABLE OF PRODUCING HEAVY RAIN...POSSIBLY UP TO AN INCH PER HOUR
OR LESS FROM A STRONG STORM.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KRIEDERMAN
LONG TERM....D-L
AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 PM MDT THU AUG 1 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
CURRENTLY...SHORTWAVE TROUGH AND UPPER VORT MAX ARE CURRENTLY
EJECTING EASTWARD ACROSS COLORADO...WHILE A SECONDARY WAVE MOVES
NORTHWARD OUT OF NEW MEXICO INTO SOUTHERN COLORADO. RADAR INDICATES
WIDESPREAD CONVECTION OVER THE MOUNTAIN AREAS AND SPREADING EAST
INTO THE I-25 CORRIDOR. TEMPERATURES HAVE BEEN WARM WITH UPPER 80S
TO LOWER 90S FOR THE PLAINS.
THROUGH TONIGHT...MODELS HAVING A HARD TIME WITH THIS UPPER LEVEL
DISTURBANCE AND THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION.
THE LATEST RAP AND HRRR SEEM TO HAVE A BETTER HANDLE WITH THE LATEST
RUNS WITH CONVECTION SPREADING EAST ACROSS THE PLAINS THROUGH THE
EVENING HOURS. DEW POINTS IN THE UPPER 50S AND PWAT VALUES
APPROACHING AN INCH HAVE LED TO LOCALLY HEAVY RAINFALL WITH THESE
THUNDERSTORMS. OF CONCERN ARE AREA BURN SCARS...WHICH COULD SEE
LOCALIZED FLASH FLOODING WITH ANY HEAVY CELLS THAT MOVE OVER THEM.
WHILE THE WEST FORK COMPLEX HAS ONLY SEEN LIGHT PRECIP SO FAR
TODAY...THE UPPER DISTURBANCE MOVING NORTH OUT OF NEW MEXICO SHOULD
PROVIDE ENHANCED LIFT AND CONTINUED THREAT FOR HEAVY RAINFALL
THROUGH THIS EVENING. NOT MUCH OF A SEVERE WEATHER THREAT ACROSS
THE PLAINS THIS EVENING. THERE COULD BE SOME DIME TO PENNY SIZE
HAIL WITH THE STRONGEST CELLS...ESPECIALLY SOUTH OF HIGHWAY 50
THROUGH ABOUT 9PM TONIGHT. EXPECT MOST ACTIVITY TO SHIFT EAST WITH
THE UPPER WAVE AFTER MIDNIGHT WITH SHOWER AND THUNDERSTORM ACTIVITY
COMING TO AN END THROUGH FRIDAY MORNING. THE EXCEPTION WILL BE THE
SAN JUAN RANGE WHERE THE EJECTING UPPER DISTURBANCE WILL LIKELY KEEP
THUNDERSTORMS GOING INTO FRIDAY MORNING.
FRIDAY...THE UPPER LEVEL DISTURBANCE OUT OF NEW MEXICO WILL TRACK
INTO SOUTHWEST KANSAS BY FRIDAY AFTERNOON WHILE A WEAK BOUNDARY
SHIFTS SOUTH INTO THE PLAINS. DRIER AIR AND SUBSIDENCE BEHIND THE
DEPARTING WAVE SHOULD LIMIT THUNDERSTORM ACTIVITY TO THE MOUNTAIN
AREAS...AND NEAR THE NEW MEXICO BORDER. THE MAIN THREATS WILL
CONTINUE TO BE LOCALIZED HEAVY RAINFALL AND LIGHTNING. GIVEN THE
DECREASE IN MOISTURE...THE FLASH FLOOD RISK WILL LIKELY BE MINIMAL
OVER THE WEST FORK COMPLEX...BUT ANY CELLS THAT DO MOVE OVER THE
BURN SCAR COULD PRODUCE A QUICK BURST OF RAINFALL. TEMPERATURES
WILL REMAIN WARM WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S ACROSS
THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
...SUMMER MONSOON WILL STICK AROUND FOR A WHILE...
ALL IN ALL...GOOD NEW IN THE WEATHER DEPARTMENT...THE SUMMER MONSOON
LOOKS ALIVE AND WELL THROUGH AT LEAST NEXT WEEK. THERE WILL BE
WETTER DAYS AND DRIER DAYS...BUT THE MONSOON PLUME WILL GENERALLY
REMAIN OVER COLORADO. NOT EVERYONE WILL GET RAIN EVERYDAY...SUMMER
CONVECTION IS PRETTY MUCH ALWAYS HIT OR MISS. BUT...OVER
TIME...MOST WILL GET THERE SHARE OF THE MONSOON...MAYBE ONLY 1 DAY
IN THE NEXT 7...MAYBE 2 DAYS...MAYBE EVEN 3 DAYS OR MORE. BUT...THE
SHOWERS WILL BE AROUND...AND THE HUMIDITIES WILL BE UP...ALL GOOD
FOR COLORADO. WELL...MAYBE NOT SO GOOD FOR THE BURN SCAR AREAS...OF
COURSE.
FRIDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
AREA...ESPECIALLY MOUNTAINS AND RIDGES.
SATURDAY CONTINUES TO LOOK LIKE A GOOD CHANCE OF SHOWERS OVER MOST
OF THE AREA...BUT ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS.
A SIGNIFICANT SURFACE BOUNDARY IS STILL POISED TO MOVE THROUGH THE
EASTERN PLAINS THIS DAY AND INTERACT WITH THE MONSOON PLUME...TO
PRODUCE MORE WIDESPREAD PRECIPITATION THAN TYPICAL. WITH THE
GREATER NUMBER OF SHOWERS AROUND...AND THE GREATER LIFTING PROVIDED
BY THE SURFACE BOUNDARY...THIS WILL INCREASE THE HEAVY RAIN
POTENTIAL AT ANY ONE LOCATION THIS DAY. SO...THE BURN SCAR FLASH
FLOOD THREAT WILL BE UP.
SUNDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR
CONVECTION...ESPECIALLY MOUNTAINS AND RIDGES AGAIN.
LATER MONDAY THROUGH THE REMAINDER OF THE WEEK CONTINUES TO LOOK
INTERESTING WITH THE CHANCES FOR AFTERNOON AND NIGHTLY SHOWERS AND
THUNDERSTORMS GOING UP THROUGH THE PERIOD. STARTING MONDAY
NIGHT...A SERIES OF SURFACE BOUNDARIES WILL START TO MOVE THROUGH
THE EASTERN HALF OF THE FORECAST AREA. THESE BOUNDARIES WILL BE
TIED TO A SLOWLY MOVING BROAD UPPER LEVEL TROUGH DROPPING SOUTHWARD
THROUGH THE NORTHERN PLAINS DURING THE PERIOD. THE JET STREAM ON
THE SOUTH SIDE OF THIS TROUGH WILL TEND TO SEND SURFACE BOUNDARIES
SOUTH THROUGH THE PLAINS ON A REGULAR BASIS...THUS...INCREASING THE
AMOUNT OF LOW LEVEL UPSLOPE FLOW OVER THE EAST. THE INCREASED
LIFTING OF THE AIR ASSOCIATED WITH THE UPSLOPE COMBINED WITH A
STRONG MONSOON PRESENCE WILL SET THE STAGE FOR REPEATED ROUNDS OF
SHOWERS...HEAVY AT TIMES...THROUGH THE PERIOD. IF CURRENT FORECASTS
VERIFY...THE BURN SCAR AREAS WILL LIKELY NEED TO BE ON HIGH ALERT
MOST OF NEXT WEEK. LW
&&
.AVIATION...ISSUED AT 1130 PM MDT THU AUG 1 2013
VFR CONDITIONS ARE ANTICIPATED OVER THE KCOS AND KPUB TAF SITES
THROUGH TONIGHT. FOR THE KALS TAF SITE...AREAS OF LOW CLOUDS AND
FOG WILL BE POSSIBLE...ESPECIALLY AFTER MIDNIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1127 PM MDT THU AUG 1 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
CURRENTLY...SHORTWAVE TROUGH AND UPPER VORT MAX ARE CURRENTLY
EJECTING EASTWARD ACROSS COLORADO...WHILE A SECONDARY WAVE MOVES
NORTHWARD OUT OF NEW MEXICO INTO SOUTHERN COLORADO. RADAR INDICATES
WIDESPREAD CONVECTION OVER THE MOUNTAIN AREAS AND SPREADING EAST
INTO THE I-25 CORRIDOR. TEMPERATURES HAVE BEEN WARM WITH UPPER 80S
TO LOWER 90S FOR THE PLAINS.
THROUGH TONIGHT...MODELS HAVING A HARD TIME WITH THIS UPPER LEVEL
DISTURBANCE AND THE AMOUNT OF CONVECTION FIRING ACROSS THE REGION.
THE LATEST RAP AND HRRR SEEM TO HAVE A BETTER HANDLE WITH THE LATEST
RUNS WITH CONVECTION SPREADING EAST ACROSS THE PLAINS THROUGH THE
EVENING HOURS. DEW POINTS IN THE UPPER 50S AND PWAT VALUES
APPROACHING AN INCH HAVE LED TO LOCALLY HEAVY RAINFALL WITH THESE
THUNDERSTORMS. OF CONCERN ARE AREA BURN SCARS...WHICH COULD SEE
LOCALIZED FLASH FLOODING WITH ANY HEAVY CELLS THAT MOVE OVER THEM.
WHILE THE WEST FORK COMPLEX HAS ONLY SEEN LIGHT PRECIP SO FAR
TODAY...THE UPPER DISTURBANCE MOVING NORTH OUT OF NEW MEXICO SHOULD
PROVIDE ENHANCED LIFT AND CONTINUED THREAT FOR HEAVY RAINFALL
THROUGH THIS EVENING. NOT MUCH OF A SEVERE WEATHER THREAT ACROSS
THE PLAINS THIS EVENING. THERE COULD BE SOME DIME TO PENNY SIZE
HAIL WITH THE STRONGEST CELLS...ESPECIALLY SOUTH OF HIGHWAY 50
THROUGH ABOUT 9PM TONIGHT. EXPECT MOST ACTIVITY TO SHIFT EAST WITH
THE UPPER WAVE AFTER MIDNIGHT WITH SHOWER AND THUNDERSTORM ACTIVITY
COMING TO AN END THROUGH FRIDAY MORNING. THE EXCEPTION WILL BE THE
SAN JUAN RANGE WHERE THE EJECTING UPPER DISTURBANCE WILL LIKELY KEEP
THUNDERSTORMS GOING INTO FRIDAY MORNING.
FRIDAY...THE UPPER LEVEL DISTURBANCE OUT OF NEW MEXICO WILL TRACK
INTO SOUTHWEST KANSAS BY FRIDAY AFTERNOON WHILE A WEAK BOUNDARY
SHIFTS SOUTH INTO THE PLAINS. DRIER AIR AND SUBSIDENCE BEHIND THE
DEPARTING WAVE SHOULD LIMIT THUNDERSTORM ACTIVITY TO THE MOUNTAIN
AREAS...AND NEAR THE NEW MEXICO BORDER. THE MAIN THREATS WILL
CONTINUE TO BE LOCALIZED HEAVY RAINFALL AND LIGHTNING. GIVEN THE
DECREASE IN MOISTURE...THE FLASH FLOOD RISK WILL LIKELY BE MINIMAL
OVER THE WEST FORK COMPLEX...BUT ANY CELLS THAT DO MOVE OVER THE
BURN SCAR COULD PRODUCE A QUICK BURST OF RAINFALL. TEMPERATURES
WILL REMAIN WARM WITH AFTERNOON HIGHS IN THE MID TO UPPER 90S ACROSS
THE LOWER ELEVATIONS. MOZLEY
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 342 PM MDT THU AUG 1 2013
...SUMMER MONSOON WILL STICK AROUND FOR A WHILE...
ALL IN ALL...GOOD NEW IN THE WEATHER DEPARTMENT...THE SUMMER MONSOON
LOOKS ALIVE AND WELL THROUGH AT LEAST NEXT WEEK. THERE WILL BE
WETTER DAYS AND DRIER DAYS...BUT THE MONSOON PLUME WILL GENERALLY
REMAIN OVER COLORADO. NOT EVERYONE WILL GET RAIN EVERYDAY...SUMMER
CONVECTION IS PRETTY MUCH ALWAYS HIT OR MISS. BUT...OVER
TIME...MOST WILL GET THERE SHARE OF THE MONSOON...MAYBE ONLY 1 DAY
IN THE NEXT 7...MAYBE 2 DAYS...MAYBE EVEN 3 DAYS OR MORE. BUT...THE
SHOWERS WILL BE AROUND...AND THE HUMIDITIES WILL BE UP...ALL GOOD
FOR COLORADO. WELL...MAYBE NOT SO GOOD FOR THE BURN SCAR AREAS...OF
COURSE.
FRIDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS ACROSS THE
AREA...ESPECIALLY MOUNTAINS AND RIDGES.
SATURDAY CONTINUES TO LOOK LIKE A GOOD CHANCE OF SHOWERS OVER MOST
OF THE AREA...BUT ESPECIALLY FOR THE EASTERN MOUNTAINS AND PLAINS.
A SIGNIFICANT SURFACE BOUNDARY IS STILL POISED TO MOVE THROUGH THE
EASTERN PLAINS THIS DAY AND INTERACT WITH THE MONSOON PLUME...TO
PRODUCE MORE WIDESPREAD PRECIPITATION THAN TYPICAL. WITH THE
GREATER NUMBER OF SHOWERS AROUND...AND THE GREATER LIFTING PROVIDED
BY THE SURFACE BOUNDARY...THIS WILL INCREASE THE HEAVY RAIN
POTENTIAL AT ANY ONE LOCATION THIS DAY. SO...THE BURN SCAR FLASH
FLOOD THREAT WILL BE UP.
SUNDAY LOOKS A BIT DRIER...BUT STILL MOIST ENOUGH FOR
CONVECTION...ESPECIALLY MOUNTAINS AND RIDGES AGAIN.
LATER MONDAY THROUGH THE REMAINDER OF THE WEEK CONTINUES TO LOOK
INTERESTING WITH THE CHANCES FOR AFTERNOON AND NIGHTLY SHOWERS AND
THUNDERSTORMS GOING UP THROUGH THE PERIOD. STARTING MONDAY
NIGHT...A SERIES OF SURFACE BOUNDARIES WILL START TO MOVE THROUGH
THE EASTERN HALF OF THE FORECAST AREA. THESE BOUNDARIES WILL BE
TIED TO A SLOWLY MOVING BROAD UPPER LEVEL TROUGH DROPPING SOUTHWARD
THROUGH THE NORTHERN PLAINS DURING THE PERIOD. THE JET STREAM ON
THE SOUTH SIDE OF THIS TROUGH WILL TEND TO SEND SURFACE BOUNDARIES
SOUTH THROUGH THE PLAINS ON A REGULAR BASIS...THUS...INCREASING THE
AMOUNT OF LOW LEVEL UPSLOPE FLOW OVER THE EAST. THE INCREASED
LIFTING OF THE AIR ASSOCIATED WITH THE UPSLOPE COMBINED WITH A
STRONG MONSOON PRESENCE WILL SET THE STAGE FOR REPEATED ROUNDS OF
SHOWERS...HEAVY AT TIMES...THROUGH THE PERIOD. IF CURRENT FORECASTS
VERIFY...THE BURN SCAR AREAS WILL LIKELY NEED TO BE ON HIGH ALERT
MOST OF NEXT WEEK. LW
&&
.AVIATION...ISSUED AT 1125 PM MDT THU AUG 1 2013
VFR CONDITIONS ARE ANTICIPATE OVER THE KALS...KCOS AND KPUB
TAF SITES THROUGH TONIGHT.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
353 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT MOVES THROUGH NEW ENGLAND SATURDAY MORNING BRINGING A
CHANCE OF SHOWERS/THUNDERSTORMS. MOSTLY DRY WEATHER EXPECTED
EARLY NEXT WEEK WITH POTENTIAL FOR SOME SPOTTY SHOWERS SUN. A MID
WEEK STORM MAY BRING MORE WIDESPREAD RAIN.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THROUGH 00Z...
PLENTY OF DIURNAL CUMULUS POPPED DURING THE AFTERNOON AND WILL
CONTINUE THROUGH EVENING. SCATTERED SHOWERS/TSTMS ARE POSSIBLE
FROM THESE CLOUDS AS SBCAPE VALUES /PER SPC MESOANALYSIS/ ARE
1000-1500 J/KG. ONE TSTM COMPLEX MOVING ACROSS CENTRAL NY
EXTRAPOLATES TO THE CT VALLEY AROUND 22Z. HRRR AGREES WITH THIS
TIMING. WE BRING CHANCE POPS INTO THE CT VALLEY 22Z-00Z WITH
SLIGHT CHANCE POPS FARTHER EAST.
TONIGHT...
THE REMAINS OF THE NY SHOWERS/TSTMS WILL MOVE ACROSS THE REGION
00Z TO 02Z AND THEN MOVE OFFSHORE. WE ARE EXPECTING A PERIOD OF
CLEARING FOR A FEW HOURS AFTER THAT. WITH LIGHT WINDS AND
DEWPOINTS IN THE 50S INLAND...WE EXPECT TEMPS WILL DROP BELOW 60
MOST PLACES AWAY FROM THE COAST.
COLD FRONT APPROACHING FROM THE WEST WILL SPREAD MORE CLOUDS IN
LATE AT NIGHT WITH SOME POTENTIAL FOR PCPN. WE HAVE SLIGHT CHANCE
POPS DEVELOPING WEST TO EAST AFTER 2 AM.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...COLD FRONT CROSSES NEW ENGLAND THE FIRST PART OF
SATURDAY. THE RIGHT ENTRANCE REGION OF A 110 KNOT UPPER JET IS IN
PLACE TO PROVIDE UPPER VENTING...BUT MOISTURE AND INSTABILITY ARE
LESS FAVORABLE. THE GFS DOES SHOW MID LEVEL LAPSE RATES 6-6.5C/KM
SATURDAY MORNING...BUT THIS MOVES OFFSHORE BY AFTERNOON. TIMING
OF THE FROPA IS ALSO IN A LESS FAVORABLE TIME OF THE DAY. WE WILL
FEATURE CHANCE POPS ALL AREAS DURING THE MORNING AND LINGERING
POPS IN RI AND SOUTHEAST MASS FOR PART OF THE AFTERNOON.
SATURDAY NIGHT...
THIS LOOKS LIKE A QUIET COOL NIGHT. A SHORTWAVE DIGS OVER THE
GREAT LAKES AND MOVES EAST TOWARD NEW ENGLAND. THIS MAY BRING
INCREASING CLOUDS TO US LATE AT NIGHT...BUT ANY SHOWERS LOOK LIKE
THEY SHOULD STAY TO OUR WEST DURING THE NIGHT. FAIR SKIES AND
DEWPOINTS IN THE 50S SHOULD ALLOW MIN TEMPS IN THAT RANGE EXCEPT
LOW 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SUNDAY
* NEXT CHANCE OF WIDESPREAD RAIN THU
MODELS ARE IN DECENT AGREEMENT THROUGH THE EARLY PART OF NEXT WEEK.
EVEN TOWARDS THE END OF NEXT WEEK THERE ARE ONLY A FEW MINOR
DISCREPANCIES AND MORE IN THE TIMING RATHER THAN THE OVERALL
PATTERN. SUNDAY THROUGH TUESDAY...HIGH PRESSURE BUILDS INTO THE
REGION AND THEN MOVES OFFSHORE BRINGING SEASONABLY COOL AND DRY
WEATHER TO SOUTHERN NEW ENGLAND. WEDNESDAY ALSO LOOKS TO BE MAINLY
DRY...THOUGH BOTH THE ECMWF AND THE GFS START TO BRING IN SOME RAIN
LATE WEDNESDAY EVENING. WIDESPREAD RAINFALL IS EXPECTED THURSDAY
AHEAD OF A COLD FRONT EXTENDING FROM LOW PRESSURE IN QUEBEC. THERE
ARE A FEW TIMING DISCREPANCIES HERE BETWEEN THE ECMWF AND GFS WITH
HOW QUICKLY THE COLD FRONT MOVES THROUGH WITH THE GFS A BIT QUICKER
WITH MOVING OUT THE PRECIP THAN THE ECMWF.
SUNDAY...HIGH PRESSURE STARTS BUILDING INTO THE REGION SUNDAY BUT
WITH A SHORTWAVE MOVING ACROSS SOUTHERN NEW ENGLAND...A FEW DIURNAL
SHOWERS ARE POSSIBLE SUNDAY AFTERNOON. HAVE SLIGHT CHANCE TO CHANCE
POPS ACROSS MUCH OF SOUTHERN NEW ENGLAND FOR THIS TIME PERIOD.
OTHERWISE...EXPECT THE BEGINNING OF A COOLING TREND WITH
TEMPERATURES RIGHT AT OR JUST BELOW NORMAL.
MONDAY AND TUESDAY...HIGH PRESSURE MOVES OVER SOUTHERN NEW ENGLAND
MONDAY AND THEN OFFSHORE TUESDAY BRINGING MOSTLY DRY WEATHER AND
BELOW NORMAL TEMPS FOR EARLY AUGUST.
WEDNESDAY THROUGH FRIDAY...A SHORTWAVE MOVES ACROSS SOUTHERN NEW
ENGLAND WEDNESDAY AS LOW PRESSURE STARTS TO MOVE INTO QUEBEC. A
COLD FRONT EXTENDING SOUTHWARD WILL MOVE ACROSS THE AREA THURSDAY
EVENING AND PUSH OFFSHORE OVERNIGHT. COULD SEE RAIN BEGIN WEDNESDAY
EVENING THEN CONTINUE THROUGH MUCH OF THURSDAY AHEAD OF THE FRONT.
THIS LOOKS LIKE IT WILL BE MORE OF A HEAVY RAIN THREAT WITH PWATS
SURGING TO ABOVE 2 INCHES AGAIN BUT THERE IS POTENTIAL FOR
THUNDERSTORMS WITH STEEP MID LEVEL LAPSE RATES AND DECENT
INSTABILITY AHEAD OF THE FRONT. THEN FRIDAY SHOULD BE ANOTHER
RELATIVELY QUIET DAY AS THE FRONT PUSHES OFFSHORE AND DRY...SLIGHTLY
COOLER WEATHER RETURNS.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN THE TREND TOWARD VFR...LOWER CONFIDENCE IN
EXACT TIMING OVER THE NEXT FEW HOURS.
TONIGHT...WEST WINDS AROUND 10 KNOTS AND A FEW GUSTS NEAR 20
KNOTS DIMINISHING THIS EVENING. AN AREA OF SHOWERS/TSTMS MOVES
ACROSS SOUTHERN NEW ENGLAND THIS EVENING...ENTERING THE CT VALLEY
AROUND 22Z AND LEAVING THE EAST MASS COAST AROUND 02Z. BEST CHANCE
OF SHOWERS WILL BE ALONG AND NORTH OF THE MASS TURNPIKE. GENERALLY
VFR WITH A BRIEF DIP TO MVFR CIGS/VSBYS POSSIBLE IN ANY
SHOWERS/TSTMS.
SATURDAY...A COLD FRONT MOVES THROUGH DURING THE MORNING WITH
ANOTHER CHANCE OF SHOWERS AND SCATTERED TSTMS WITH BRIEF MVFR
CIGS/VSBYS.
SATURDAY NIGHT...VFR.
KBOS TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 9 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
KBDL TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 6-7 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...MODERATE TO HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY
OF BRIEF MVFR/IFR CONDITIONS IN ISOLATED TO SCATTERED SHOWERS.
MONDAY THROUGH WEDNESDAY...HIGH CONFIDENCE. VFR. LOW PROBABILITY
OF MVFR/IFR CONDITIONS IN SCT SHRA/FG WEDNESDAY NIGHT.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS SHOULD REMAIN BELOW 25 KNOTS MOST OF THE TIME...BUT A FEW
GUSTS NEAR 25 KNOTS POSSIBLE AROUND NANTUCKET SOUND SATURDAY
AFTERNOON. SEAS WILL BUILD ON THE SOUTHERN OUTER COASTAL WATERS
TONIGHT AND SATURDAY WITH 5 FOOT VALUES EXPECTED. SEAS THEN
DIMINISH DURING SATURDAY NIGHT.
A SMALL CRAFT ADVISORY CONTINUES FOR THE SOUTHERN OUTER COASTAL
WATERS. IF LATER INFORMATION ON WINDS GOES STRONGER...THE SCA MAY
BE EXPANDED CLOSER TO SHORE.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
HIGH CONFIDENCE. MOSTLY QUIET BOATING WEATHER EXPECTED SUNDAY
THROUGH WEDNESDAY. SEAS START TO INCREASE TO AROUND 5 FEET ON THE
OUTER WATERS ON THURSDAY. MAINLY WESTERLY WINDS WILL REMAIN BELOW
25 KTS FOR THE MOST PART SHIFTING TO THE SOUTHWEST OR NORTHWEST AT
TIMES THROUGH THE PERIOD. WINDS SHIFT TO THE SOUTH WEDNESDAY AND
WEDNESDAY NIGHT.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 2 AM EDT SUNDAY
FOR ANZ254>256.
&&
$$
SYNOPSIS...WTB/RLG
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...RLG
AVIATION...WTB/RLG
MARINE...WTB/RLG
AREA FORECAST DISCUSSION
NWS TAUNTON MA
347 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT MOVES THROUGH NEW ENGLAND SATURDAY MORNING BRINGING A
CHANCE OF SHOWERS/THUNDESTORMS. ANOTHER FRONT MOVES THROUGH ON
SUNDAY. HIGH PRESSURE THEN BRINGS DRY WEATHER FOR THE FIRST HALF
OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
THROUGH 00Z...
PLENTY OF DIURNAL CUMULUS POPPED DURING THE AFTERNOON AND WILL
CONTINUE THROUGH EVENING. SCATTERD SHOWERS/TSTMS ARE POSSIBLE FROM
THESE CLOUDS AS SBCAPE VALUES /PER SPC MESOANALYSIS/ ARE
1000-1500 J/KG. ONE TSTM COMPLEX MOVING ACROSS CENTRAL NY
EXTRAPOLATES TO THE CT VALLEY AROUND 22Z. HRRR AGREES WITH THIS
TIMING. WE BRING CHANCE POPS INTO THE CT VALLEY 22Z-00Z WITH
SLIGHT CHANCE POPS FARTHER EAST.
TONIGHT...
THE REMAINS OF THE NY SHOWERS/TSTMS WILL MOVE ACROSS THE REGION
00Z TO 02Z AND THEN MOVE OFFSHORE. WE ARE EXPECTING A PERIOD OF
CLEARING FOR A FEW HOURS AFTER THAT. WITH LIGHT WINDS AND
DEWPOINTS IN THE 50S INLAND...WE EXPECT TEMPS WILL DROP BELOW 60
MOST PLACES AWAY FROM THE COAST.
COLD FRONT APPROACHING FROM THE WEST WILL SPREAD MORE CLOUDS IN
LATE AT NIGHT WITH SOME POTENTIAL FOR PCPN. WE HAVE SLIGHT CHANCE
POPS DEVELOPING WEST TO EAST AFTER 2 AM.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
SATURDAY...COLD FRONT CROSSES NEW ENGLAND THE FIRST PART OF
SATURDAY. THE RIGHT ENTRANCE REGION OF A 110 KNOT UPPER JET IS IN
PLACE TO PROVIDE UPPER VENTING...BUT MOISTURE AND INSTABILITY ARE
LESS FAVORABLE. THE GFS DOES SHOW MID LEVEL LAPSE RATES 6-6.5C/KM
SATURDAY MORNING...BUT THIS MOVES OFFSHORE BY AFTERNOON. TIMING
OF THE FROPA IS ALSO IN A LESS FAVORABLE TIME OF THE DAY. WE WILL
FEATURE CHANCE POPS ALL AREAS DURING THE MORNING AND LINGERING
POPS IN RI AND SOUTHEAST MASS FOR PART OF THE AFTERNOON.
SATURDAY NIGHT...
THIS LOOKS LIKE A QUIET COOL NIGHT. A SHORTWAVE DIGS OVER THE
GREAT LAKES AND MOVES EAST TOWARD NEW ENGLAND. THIS MAY BRING
INCREASING CLOUDS TO US LATE AT NIGHT...BUT ANY SHOWERS LOOK LIKE
THEY SHOULD STAY TO OUR WEST DURING THE NIGHT. FAIR SKIES AND
DEWPOINTS IN THE 50S SHOULD ALLOW MIN TEMPS IN THAT RANGE EXCEPT
LOW 60S ALONG THE COAST.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER
* FEW SHOWERS POSSIBLE SATURDAY...SUNDAY...AND TUESDAY
* NEXT CHANCE OF WIDESPREAD RAIN WED INTO THU
OVERVIEW AND MODEL PREFERENCES...
02/00Z MODEL GUIDANCE SUITE IS IN AT LEAST REASONABLE AGREEMENT
THROUGH THE LONG TERM SUCH THAT THE SYNOPTIC FEATURES ARE IN LINE.
THERE ARE SOME SMALLER SCALE DIFFERENCES WHICH WILL DEFINE THE WX
PARTICULARLY LATER IN THE WORK WEEK...BUT GIVEN THE FACT THAT GFS
AND ECMWF DETERMINISTIC RUNS ARE IN FAIR AGREEMENT...WILL BE USING
A BLEND OF THESE AS A BASELINE FOR THIS FORECAST UPDATE. THE SAT
NIGHT INTO SUN TIMEFRAME WILL BE UNDER THE INFLUENCE OF A STRONG
SHORTWAVE DIVING INTO THE ONTARIO/QUEBEC LONGWAVE TROF...WHICH
WILL THEN CULMINATE IN A CUTOFF MOVING INTO THE
MARITIMES...SEPARATING FROM THE HUDSON BAY CUTOFF. WITH THIS
DIGGING TROF AND SHORTWAVE...AND ITS ATTENDANT SFC COLD
FRONT...THERE WILL THE RENEWED CHANCE FOR SOME SCT PRECIP ON
SUN...PARTICULARLY THROUGH NRN NEW ENGLAND. WITH THIS INITIAL
CUTOFF SEPARATING FROM THE CUTOFF CENTERED ON HUDSON BAY...THIS
WILL ALLOW THE BROAD TROF TO GIVE WAY TO SOME ENHANCED RIDGING
FROM THE SRN CONUS...LENDING TOWARD A DRY HIGH PRES FOR MUCH OF
THE EARLY HALF OF THE WEEK.
A TRANSITION IS ON TAP FOR THE END OF THE WEEK AS VERY STRONG
RIDGING IN NW CANADA FOLDS OVER...FORCING THE HUDSON BAY CUTOFF TO
DIG S ITSELF LEADING TOWARD ANOTHER STRONG TROF FOR THE NORTHEAST.
GIVEN THE HIGHLY AMPLIFIED FLOW PATTERN DRIVING THIS SYSTEM...AND
TYPICAL MODEL BIASES IN THE EXTENDED...TIMING IS SOMEWHAT IN
QUESTION. HOWEVER...IT APPEARS THAT A DRY TO WET/UNSETTLED
TRANSITION IS LIKELY IN THE WED/THU PERIOD.
DETAILS...
SAT NIGHT AND SUN...
STRONG KICKER SHORTWAVE WILL BE SLIDING THROUGH THE LONGWAVE TROF
TO THE N WITH AN ATTENDANT COLD FRONT IN TOW. AM NOTING ENOUGH
LIFT FOR AT LEAST A FAIR AMOUNT OF CLOUD COVER WITH THIS FROPA.
HOWEVER...GENERALLY W-NW FLOW INITIALLY COLUMN MAY BE A BIT TOO
DRY FOR WIDESPREAD SHOWERS. BETTER FORCING N...SO WILL TAPER POPS
FOR SUN WITH CHANCE OVER NRN MA/SRN NH...TO SLIGHT CHANCE NEAR THE
S COAST. NOT OUT OF THE QUESTION MANY LOCATIONS REMAIN DRY WITH
THIS FINAL FRONT UNLESS BETTER DYNAMICS ARE FORECAST IN THE NEXT
48 HOURS. INSTABILITY IS MODEST...BUT APPARENT...SO WILL ALSO
INCLUDE AN ISOLATED THREAT FOR T-STORMS. TEMPS WILL BE NEAR TO
SLIGHTLY BELOW NORMAL THANKS TO COOL AIRMASS AND CLOUD COVER.
SUN NIGHT INTO TUE NIGHT...
MID LVL RIDGING GETS A CHANCE TO BUILD IN AS CUTOFF LOW SHIFTS
INTO THE MARITIMES. DRY HIGH PRES WILL SLIDE THROUGH THE REGION
FROM THE W. EXPECTING A MOSTLY DRY PERIOD. TEMPS WILL START ON THE
COOL SIDE OF NORMAL...MODERATING GRADUALLY THROUGH THE PERIOD.
HUMIDITY WILL ALSO START LOW AND INCREASE SLOWLY.
WED INTO FRI...
STRONGER WAVE OF LOW PRES ALOFT WILL SLIDE INTO SRN CANADA WITH
DEEPENING AND DIGGING TROF OVER THE NORTHEAST CONUS.
THEREFORE...EXPECT A TRANSITION TO WET AND UNSETTLED BEGINNING
WED. AT THIS TIME...THE LOW PRES ASSOCIATED WITH THIS FEATURE IS
PROGGED TO REMAIN IN QUEBEC AND ONTARIO...WITH STRONG WARM AND
COLD FRONT TO MOVE THROUGH NEW ENGLAND. IT DOES APPEAR THAT AT
LEAST SRN NEW ENGLAND WILL BREAK INTO THE WARM SECTOR SOMETIME THU
AHEAD OF THE INITIAL STRONG COLD FRONT...SO WILL BE ADDING A
THREAT FOR THUNDER.
GIVEN THE TROF WILL BE DIGGING/TRANSITIONING THROUGH THE WHOLE
THREE DAY PERIOD THE LOW PRES AND FRONT MAY BE SLOW TO MOVE
THROUGH...SO WILL BE KEEPING POPS AROUND UNTIL FRI. EVEN THOUGH
THERE WILL BE POPS THE ENTIRE THREE DAY PERIOD...SOME BREAKS ARE
POSSIBLE ESPECIALLY IF THE ACTIVITY IS MORE CONVECTIVE AS THE
RECENT MODELS SUGGEST.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE IN THE TREND TOWARD VFR...LOWER CONFIDENCE IN
EXACT TIMING OVER THE NEXT FEW HOURS.
TONIGHT...WEST WINDS AROUND 10 KNOTS AND A FEW GUSTS NEAR 20
KNOTS DIMINISHING THIS EVENING. AN AREA OF SHOWERS/TSTMS MOVES
ACROSS SOUTHERN NEW ENGLAND THIS EVENING...ENTERING THE CT VALLEY
AROUND 22Z AND LEAVING THE EAST MASS COAST AROUND 02Z. BEST CHANCE
OF SHOWERS WILL BE ALONG AND NORTH OF THE MASS TURNPIKE. GENERALLY
VFR WITH A BRIEF DIP TO MVFR CIGS/VSBYS POSSIBLE IN ANY
SHOWERS/TSTMS.
SATURDAY...A COLD FRONT MOVES THROUGH DURING THE MORNING WITH
ANOTHER CHANCE OF SHOWERS AND SCATTERED TSTMS WITH BRIEF MVFR
CIGS/VSBYS.
SATURDAY NIGHT...VFR.
KBOS TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 9 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
KBDL TERMINAL...HIGH CONFIDENCE. BRIEF MVFR CIGS/VSBYS POSSIBLE
AROUND 6-7 PM AS AN AREA OF SHOWERS/TSTMS...OR THEIR
REMNANTS...WILL MOVE THROUGH. ANOTHER CHANCE OF SHOWERS TOWARD
SUNRISE SATURDAY AS A COLD FRONT MOVES THROUGH.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
SUNDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF BRIEF
MVFR CONDITIONS IN ISOLATED TO SCATTERED SHOWERS.
MONDAY...HIGH CONFIDENCE.
VFR.
TUESDAY...HIGH CONFIDENCE.
MAINLY VFR.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
WINDS SHOULD REMAIN BELOW 25 KNOTS MOST OF THE TIME...BUT A FEW
GUSTS NEAR 25 KNOTS POSSIBLE AROUND NANTUCKET SOUND SATURDAY
AFTERNOON. SEAS WILL BUILD ON THE SOUTHERN OUTER COASTAL WATERS
TONIGHT AND SATURDAY WITH 5 FOOT VALUES EXPECTED. SEAS THEN
DIMINISH DURING SATURDAY NIGHT.
A SMALL CRAFT ADVISORY CONTINUES FOR THE SOUTHERN OUTER COASTAL
WATERS. IF LATER INFORMATION ON WINDS GOES STRONGER...THE SCA MAY
BE EXPANDED CLOSER TO SHORE.
OUTLOOK...SUNDAY THROUGH TUESDAY...
HIGH CONFIDENCE.
GENERALLY QUIET BOATING WEATHER THROUGH THE PERIOD. THE ONLY
CAVEATS WILL BE FOR SOME 5 FT SEAS POSSIBLE SAT NIGHT ON THE
SOUTHEAST OCEAN WATERS...AND THE CHANCE FOR 20-25 KT NW WINDS
NEAR THE SHORELINES ON MON.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 6 PM THIS EVENING
TO 2 AM EDT SUNDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...WTB/DOODY
NEAR TERM...WTB
SHORT TERM...WTB
LONG TERM...DOODY
AVIATION...WTB/DOODY
MARINE...WTB/DOODY
AREA FORECAST DISCUSSION
NWS NEW YORK NY
344 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY WITH WEAK SURFACE LOW PRESSURE PASSING
TO OUR SOUTH SATURDAY NIGHT. A COLD FRONTAL PASSAGE ON SUNDAY
WILL USHER IN SUNNY AND COOLER WEATHER FOR THE BEGINNING OF NEXT
WEEK. A WARMING TREND...ALONG WITH AN INCREASE IN HUMIDITY...WILL
FOLLOW FOR THE MIDDLE OF THE WEEK. THERE WILL BE A CHANCE FOR RAIN
LATE WEDNESDAY THROUGH THURSDAY AS THE PATTERN ATTEMPTS TO
TRANSITION AGAIN.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
3 PM UPDATE...CONVECTION OVER CENTRAL NY STATE FORM KBGM TO KSYR. LATEST
HRRR HAS A REASONABLE HANDLE ON THIS. AS THE SHORTWAVE PRESSES
EAST INTO NEW ENGLAND SOME ADDITIONAL DEVELOP SEEMS POSSIBLE TO THE
SOUTH WHICH SATELLITE SUPPORTS CURRENTLY HAPPENING OVER WESTERN
PA. THUS KEEPING POPS OUT OF THE FCST UNTIL THIS 22Z FOR NW
SECTIONS. WILL FOLLOW THE HRRR AS IT HAS CONTINUITY WITH THE 09Z
SREF PROBABILITIES FOR THIS EVENING. CARRYING A 20-30 POP WITH
HIGHEST POP ALONG NORTHERN SECTION. WILL STILL NOT CONVERT TO
COVERAGE YET AS NOT CONFIDENT THAT CONVECTION WILL ACTUALLY REACH
OUR FCST AREA. CONTINUED TO INCLUDE TSTMS BASED ON WEAK
INSTABILITY OF A FEW HUNDRED JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
3 PM UPDATE...GOING MORE OPTIMISTIC BASED ON 09Z SREF AND 12Z
DETERMINISTIC MODELS. HAVE LOWERED POPS TO NIL OR SLIGHT CHANCE
FOR THE NY METRO. WITH LOWER POPS COMES WARMER TEMPS. NAM MOS IS
3-4 F WARMER THAN GFS MOS. WITH RECENT LOCAL BIAS OF MOS AND HUMAN
TO BE TOO WARM...HAVE CHOSEN TO STAY CLOSE TO BIAS CORRECT GFS MOS
- WHICH IS CLOSE TO OPERATIONAL GFS MOS.
WEAK LOW PRESSURE FORMING ALONG THE FRONTAL BOUNDARY TO OUR SOUTH
SUGGEST THE CHANCE OF LIGHT RA FOR NJ TO LONG ISLAND. SREF AND
12Z DETERMINISTIC RUNS ARE CONSISTENT WITH THIS. AND HAVE BEEN
FROM PREVIOUS RUNS.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
H5 TROF AXIS PASSES AROUND 18Z SUN. THERE WILL BE THE CHC FOR AN
ISOLD SHRA OR TSTM...MAINLY ACROSS THE INTERIOR WITH LESS CIN. NAM12
PROGS SBCAPE GENERALLY AOB 800 J/KG. OTHERWISE...FAIR WX CU SHOULD
DEVELOP WITH STEEPENING MID LVL LAPSE RATES.
KEY TO TEMPS SUN NGT WILL BE WHETHER WINDS FULLY DECOUPLE. GUIDANCE
STILL SUGGESTS LOWS AROUND 50 ACROSS THE INTERIOR VALLEYS AND PINE
BARRENS.
SUNNY AND DRY ON MON. TEMPS BLW CLIMO.
DESPITE SOME WEAK MID LVL MOISTURE ADVECTION MON NGT...POTENTIAL FOR
TEMPS TO BE COOLER THAN SUN NGT WITH THE HIPRES CENTERED OVER THE
MID-ATLANTIC. TRENDED THE FCST COOLER.
HEIGHTS GRADUALLY INCREASE TUE AND WED...SO EXPECT WARMING TEMPS
THRU THE PERIOD. CHCS FOR RAIN APPEAR TO HOLD OFF TIL THE DAYTIME ON
WED...WHERE ENOUGH INSTABILITY MAY DEVELOP ACROSS THE WRN ZONES TO
ALLOW FOR CONVECTIVE INITIATION. POCKETS OF SHRA/TSTMS WILL BE
POSSIBLE THRU WED NGT WITH FOCUSED WAA ALOFT.
CWA MAY BE WEDGED BETWEEN THE SRN CONUS RIDGE AND CANADIAN H5 LOW
FOR THU AND BEYOND. THIS WILL MEAN THE CONVECTIVE ZONE COULD BE NEAR
OR OVER TO THE CWA. IT IS ALSO POSSIBLE THAT IF THIS ZONE OF
CONVECTION REMAINS JUST TO THE N...THE METRO WILL BE IN FOR A FEW
DAYS OF HOT AND HUMID WX. FOR NOW...THE OFFICIAL FCST IS CLOSER TO
THE RAINIER SOLN...AS THIS HAS BEEN THE MORE CONSISTENT PROG OVER
THE LAST FEW DAYS.
&&
.AVIATION /19Z FRIDAY THROUGH WEDNESDAY/...
WEAKENING HIGH PRESSURE GIVES WAY TO AN APPROACHING COLD FRONT BY
LATER ON SATURDAY. WITH EXCEPTION OF A POSSIBLE SHOWER OR
THUNDERSTORM...MAINLY THIS EVENING...PRIMARILY VFR CONDITIONS ARE
EXPECTED. THERE IS ANOTHER CHANCE OF SHOWERS AS WELL ON
SATURDAY...MAINLY TO THE WEST. SINCE CONFIDENCE IS LOW ON TIMING
AND LOCATION...SHOWERS OR THUNDERSTORMS HAVE BEEN LEFT OUT OF THE
TAFS AT THE MOMENT. ONLY EXCEPTION WOULD BE KSWF WITH VCSH...WHERE
SOME SHOWERS COULD PASS NEAR INTO EARLY THIS EVENING.
WINDS ARE OUT OF THE W-SW 10-15 KT GUSTING TO AROUND 20 KT. WINDS
LOWER TONIGHT AND PICK UP AGAIN ON SATURDAY AT AROUND THE SAME
DIRECTION AND SPEEDS AS THAT OF THE PREVIOUS DAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KJFK FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KLGA FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT TIMES
COULD BE 20-30 DEGREES OFF INTO EARLY THIS EVENING.
KTEB FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY.
END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS 15-20 KT POSSIBLE BEFORE
00Z.
KISP FCSTER COMMENTS: TIMING OF MORE SW WIND MAY BE OFF BY 1 HOUR.
GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY. END TIME OF GUSTS
COULD BE 1-2 HRS OFF.
.OUTLOOK FOR 18Z SAT THROUGH WED...
.REST OF SAT AFTN...MAINLY VFR. MVFR IS POSSIBLE IN SHOWERS.
.SAT NIGHT...CHANCE OF LIGHT RAIN MAINLY TOWARDS LONG ISLAND AND NYC
TERMINALS. MVFR POSSIBLE IN LIGHT RAIN.
.SUN-TUE...MAINLY VFR.
.WED...POSSIBLE SHOWERS AND THUNDERSTORMS WITH MVFR OR LOWER
POSSIBLE.
&&
.MARINE...
SEAS STILL EXPECTED TO REACH THE 5 FT CRITERIA ON THE EASTERN
OCEAN WATERS. THIS CONTINUES THROUGH SAT AND THERE`S POTENTIAL
FOR 25 KT GUSTS AS WELL LATE SATURDAY AFTERNOON. THUS THE SCA FOR
THE EASTERN WATERS IS EXTENDED INTO SATURDAY NIGHT.
OTHERWISE...WINDS REMAIN UP FOR EVENING LOCAL FISHING IN THE
MODERATE TO FRESH BREEZE RANGE THIS EVENING WITH MORE OF A FRESH
BREEZE LATE SATURDAY.
WINDS WILL BE BRISK ON SUN BUT EXPECTED TO REMAIN BLW SCA LVLS ATTM.
SPEEDS MAY INCREASE SUN NGT TO SCA LVLS BEHIND THE FRONT. THE NW
WINDS WILL DECREASE DURING THE DAY ON MON...WITH WINDS AND WAVES BLW
SCA LVLS TUE. 5 FT SEAS MAY DEVELOP ON THE OCEAN BY WED EVE WITH
INCREASING SLY FLOW.
&&
.HYDROLOGY...
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE LATE
NEXT WEEK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO MIDNIGHT EDT SATURDAY NIGHT FOR ANZ350.
&&
$$
SYNOPSIS...JMC/TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE
LONG TERM...JMC
AVIATION...JM
MARINE...JMC/TONGUE
HYDROLOGY...TONGUE
AREA FORECAST DISCUSSION
NWS NEW YORK NY
157 PM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY. CANADIAN HIGH PRESSURE FROM THE GREAT
LAKES ON SUNDAY BUILDS INTO THE REGION THROUGH TUESDAY. THE HIGH
MOVES OFFSHORE TUESDAY NIGHT AS A FRONTAL SYSTEM APPROACHES FROM
THE WEST. THE FRONTAL SYSTEM WILL AFFECT THE AREA WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1 PM UPDATE...CONVECTION HAS INITIATED OVER CENTRAL NY STATE WITH
MAIN AREA NOW APPROACHING KSYR. LATEST HRRR HAS GOOD HANDLE ON
THIS. THUS KEEPING POPS OUT OF THE FCST UNTIL AFTER 20Z FOR FAR NW
SECTION. WILL FOLLOW THE HRRR AS IT HAS CONTINUITY WITH THE 09Z
SREF PROBABILITIES FOR THIS EVENING. CARRYING A 20-30 POP WITH
HIGHEST POP ALONG NORTHERN SECTION. WILL NOT CONVERT TO COVERAGE
YET AS NOT CONFIDENT THAT CONVECTION WILL ACTUALLY REACH OUR FCST
AREA. CONTINUED TO INCLUDE TSTMS BASED ON WEAK INSTABILITY OF A
FEW HUNDRED JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /SATURDAY/...
1 PM UPDATE...GOING MORE OPTIMISTIC BASED ON 09Z SREF AND 12Z
DETERMINISTIC MODELS. HAVE LOWERED POPS TO NIL OR SLIGHT CHANCE
FOR THE NY METRO. WITH LOWER POPS COMES WARMER TEMPS. NAM MOS IS
3-4 F WARMER THAN GFS MOS. WITH RECENT LOCAL BIAS OF MOS AND
HUMAN TO BE TOO WARM...HAVE CHOSEN TO STAY CLOSE TO BIAS CORRECT
GFS MOS - WHICH IS CLOSE TO OPERATIONAL GFS MOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION SATURDAY NIGHT AS
A SHORTWAVE ROTATES THROUGH THE UPPER TROUGH ACROSS EASTERN CANADA
AND INTO THE NORTHEASTERN UNITED STATES. AN IMPULSE WILL ALSO BE
MOVING AROUND THE BASE OF THE TROUGH FROM THE MIDWEST SATURDAY
NIGHT. SO WILL HAVE CHANCE TO SLIGHT CHANCE POPS SATURDAY NIGHT.
THE UPPER TROUGH REMAINS INTO THE BEGINNING OF NEXT WEEK...AS FLOW
BECOME NEARLY ZONAL. WITH THE NEARLY STATIONARY UPPER TROUGH AND
THE NEXT SHORTWAVE SLOWER TO ROTATE INTO THE REGION AS THE UPPER
LOW CLOSES OFF HAVE DELAYED THE ONSET OF THE NEXT CHANCE OF
PRECIPITATION UNTIL LATE TUESDAY NIGHT...WITH CHANCE POPS DELAYED
UNTIL WEDNESDAY. THE NEW ECMWF 00Z/02 INDICATING THAT
PRECIPITATION MAY HOLD OFF UNTIL LATER WEDNESDAY. WITH A BLOCKING
PATTERN SETTING UP...THEN UPPER TROUGH WILL REMAIN THROUGH THE
UPCOMING WEEK AND THE ASSOCIATED SURFACE FRONTAL SYSTEM WILL BE
SLOW TO MOVE THROUGH. SO WILL HAVE CHANCES OF PRECIPITATION FOR
WEDNESDAY AND THURSDAY...AND CONTINUING INTO FRIDAY.
WITH A WEST TO NORTHWEST FLOW INTO TUESDAY AND THEN CLOUDS AND
PRECIPITATION WEDNESDAY AND THURSDAY WILL BE A RATHER COOL PERIOD.
SUNDAY AND MONDAY TEMPERATURES WERE A BLEND OF THE ECMWF AND MEX
GUIDANCE...AND THEN LEANED TOWARD THE WPC GUIDANCE...SUNDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
WEAKENING HIGH PRESSURE GIVES WAY TO AN APPROACHING COLD FRONT BY
LATER ON SATURDAY. WITH EXCEPTION OF A POSSIBLE SHOWER OR
THUNDERSTORM...MAINLY THIS EVENING...PRIMARILY VFR CONDITIONS ARE
EXPECTED. THERE IS ANOTHER CHANCE OF SHOWERS AS WELL ON SATURDAY.
SINCE CONFIDENCE IS LOW ON TIMING AND LOCATION...SHOWERS OR
THUNDERSTORMS HAVE BEEN LEFT OUT OF THE TAFS AT THE MOMENT.
WINDS ARE OUT OF THE W-SW TODAY 10-15 KT GUSTING TO AROUND 20 KT.
WINDS LOWER TONIGHT AND PICK UP AGAIN ON SATURDAY AT AROUND THE SAME
DIRECTION AND SPEEDS AS THAT OF THE PREVIOUS DAY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KJFK FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT
TIMES COULD BE 20-30 DEGREES TO THE LEFT OF FORECAST LATE THIS
AFTERNOON.
KLGA FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF. WIND DIRECTION AT
TIMES COULD BE 20-30 DEGREES TO THE LEFT OF FORECAST LATE THIS
AFTERNOON.
KTEB FCSTER COMMENTS: GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS
AFTERNOON. END TIME OF GUSTS COULD BE 1-2 HRS OFF.
KHPN FCSTER COMMENTS: OCCASIONAL GUSTS 15-20 KT POSSIBLE THIS
AFTERNOON.
KISP FCSTER COMMENTS: TIMING OF MORE SW WIND MAY BE OFF BY 1 HOUR.
GUSTS MAY BE MORE OCCASIONAL IN FREQUENCY THIS AFTERNOON. END TIME
OF GUSTS COULD BE 1-2 HRS OFF.
.OUTLOOK FOR 18Z SAT THROUGH WED...
.REST OF SAT AFTN...MAINLY VFR. MVFR IS POSSIBLE IN SHOWERS.
.SAT NIGHT...CHANCE OF LIGHT RAIN MAINLY TOWARDS LONG ISLAND AND NYC
TERMINALS. MVFR POSSIBLE IN LIGHT RAIN.
.SUN-TUE...MAINLY VFR.
.WED...POSSIBLE SHOWERS AND THUNDERSTORMS WITH MVFR OR LOWER
POSSIBLE.
&&
.MARINE...
WITH A WEAK SURFACE TROUGH DEVELOPING THIS AFTERNOON THE WIND
SHIFTS BACK TO SOUTHWEST AND SEAS OF 3 TO 4 FT ON THE OCEAN
WATERS.
A FEW GUSTS TO 20 KT ARE POSSIBLE THIS AFTERNOON...OTHERWISE...TRANQUIL
CONDS ON TAP FOR THE DAY. THIS EVENING...SEAS WILL BUILD TO 5 FT
ON THE EASTERN OCEAN WATERS...SO WILL ISSUE A SCA FOR HAZARDOUS
SEAS FOR TONIGHT. CONDS ON THE EASTERN OCEAN WATERS WILL SUBSIDE
BELOW SCA BY SATURDAY MORNING. SUB-ADVISORY CONDS ON TAP FOR
SATURDAY.
ISOLATED TSTMS ARE POSSIBLE THIS EVENING AS A WEAK SHORTWAVE
SLIDES THROUGH THE REGION. ANOTHER SHORTWAVE WILL BRING SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS SATURDAY AFTERNOON.
A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE FORECAST WATERS
SATURDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY
THROUGH TUESDAY AND MOVES EAST OF THE FORECAST WATERS TUESDAY
NIGHT AS A FRONTAL SYSTEM APPROACHES FROM THE WEST. SEAS AND WIND
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS SATURDAY
NIGHT THROUGH TUESDAY NIGHT.
&&
.HYDROLOGY...
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE
WEDNESDAY AND THURSDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO 6 AM EDT SATURDAY FOR ANZ350.
&&
$$
SYNOPSIS...MET/TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE
LONG TERM...MET
AVIATION...JM
MARINE...MET/TONGUE
HYDROLOGY...TONGUE
AREA FORECAST DISCUSSION...CORRECTION TO NEAR TERM
NWS NEW YORK NY
1045 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A SERIES OF WEAK UPPER AIR DISTURBANCES WILL PASS MAINLY NORTH OF
THE AREA THROUGH SATURDAY. CANADIAN HIGH PRESSURE FROM THE GREAT
LAKES ON SUNDAY BUILDS INTO THE REGION THROUGH TUESDAY. THE HIGH
MOVES OFFSHORE TUESDAY NIGHT AS A FRONTAL SYSTEM APPROACHES FROM
THE WEST. THE FRONTAL SYSTEM WILL AFFECT THE AREA WEDNESDAY AND
THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
10 AM UPDATE...MADE SOME MINOR CHANGES TO ACCOUNT FOR CURRENT TRENDS
IN SKY. BASICALLY EXPECTING SKC (SKY CLEAR) INTO THE MID AFTN UNTIL
SHORTWAVE APPROACHES NORTHERN ZONES LATE THIS AFTERNOON INTO EARLY
THIS EVENING. CONVERTED THE PCPN TO SLIGHT CHANCE FROM COVERAGE AS
NOT CONFIDENT THAT CONVECTION WILL FORM/REACH OUR FCST AREA. DID
INCLUDE TSTMS THOUGH BASED ON WEAK INSTABILITY OF A FEW HUNDRED
JOULES SEEN IN RUC FCST SOUNDINGS.
&&
.SHORT TERM /SATURDAY/...
10 AM UPDATE...LOTS OF UNCERTAINTY AS TO IF IT WILL RAIN OR NOT AT
ALL ON SATURDAY BASED ON THE LATEST NWP. IF IT DOES...THERE IS
ALSO UNCERTAIN IF IT`S IN THE MORNING (LIKE SEEN IN 12Z NAM AND
00Z ECMWF) OR AFTN (06Z GFS). THUS HAVE KEPT FORECAST AS IS FOR NOW.
WILL BE LOOKING AT THIS MORE FOR THE NEXT UPDATE.
OTHERWISE...HIGH PRES CONTINUES TO BUILD EAST ON SATURDAY. TEMPS WILL BE
SLIGHTLY COOLER WITH HIGHS IN THE UPPER 70S TO AROUND 80.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A WEAK COLD FRONT WILL MOVE SOUTH OF THE REGION SATURDAY NIGHT AS
A SHORTWAVE ROTATES THROUGH THE UPPER TROUGH ACROSS EASTERN CANADA
AND INTO THE NORTHEASTERN UNITED STATES. AN IMPULSE WILL ALSO BE
MOVING AROUND THE BASE OF THE TROUGH FROM THE MIDWEST SATURDAY
NIGHT. SO WILL HAVE CHANCE TO SLIGHT CHANCE POPS SATURDAY NIGHT.
THE UPPER TROUGH REMAINS INTO THE BEGINNING OF NEXT WEEK...AS FLOW
BECOME NEARLY ZONAL. WITH THE NEARLY STATIONARY UPPER TROUGH AND
THE NEXT SHORTWAVE SLOWER TO ROTATE INTO THE REGION AS THE UPPER
LOW CLOSES OFF HAVE DELAYED THE ONSET OF THE NEXT CHANCE OF
PRECIPITATION UNTIL LATE TUESDAY NIGHT...WITH CHANCE POPS DELAYED
UNTIL WEDNESDAY. THE NEW ECMWF 00Z/02 INDICATING THAT
PRECIPITATION MAY HOLD OFF UNTIL LATER WEDNESDAY. WITH A BLOCKING
PATTERN SETTING UP...THEN UPPER TROUGH WILL REMAIN THROUGH THE
UPCOMING WEEK AND THE ASSOCIATED SURFACE FRONTAL SYSTEM WILL BE
SLOW TO MOVE THROUGH. SO WILL HAVE CHANCES OF PRECIPITATION FOR
WEDNESDAY AND THURSDAY...AND CONTINUING INTO FRIDAY.
WITH A WEST TO NORTHWEST FLOW INTO TUESDAY AND THEN CLOUDS AND
PRECIPITATION WEDNESDAY AND THURSDAY WILL BE A RATHER COOL PERIOD.
SUNDAY AND MONDAY TEMPERATURES WERE A BLEND OF THE ECMWF AND MEX
GUIDANCE...AND THEN LEANED TOWARD THE WPC GUIDANCE...SUNDAY NIGHT
THROUGH THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS FOR TODAY WITH WEAK HIGH PRESSURE BUILDING IN THE
WAKE OF THE COLD FRONT.
MOD CONFIDENCE ON WINDS TODAY...SHIFTING TO A W FLOW EARLY AFTN AND
BECOMING SW BY LATE AFTN. WINDS INCREASING TO AROUND 10 KTS FOR
THE AFTN. PSBL GUSTS BETWEEN 15 AND 20 KTS MAINLY AT NYC AND LI
SITES AFTER 15Z.
FEW TO SCT MID TO HIGH LEVEL CLOUDS TODAY...WITH INCREASING
COVERAGE TONIGHT. LOW CHANCE OF SHRA/TSRA AT KSWF FOR LATE TODAY
INTO EVENING SO WILL NOT INCLUDE AT THIS TIME.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
KLGA FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE MAY BE 1-2 HRS LATER THAN IN TAF.
KTEB FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
KHPN FCSTER COMMENTS: WIND SHIFT TO LEFT OF 300 TRUE MAY BE 1-2
HRS LATER THAN IN TAF. OCNL GUSTS 15-20 KT PSBL THIS AFTN.
KISP FCSTER COMMENTS: MOD CONFIDENCE ON TIMING/STRENGTH OF GUSTS.
WIND SHIFT TO LEFT OF 300 TRUE COULD BE +/- 2 HOURS.
.OUTLOOK FOR 12Z SAT THROUGH TUE...
.SAT-SAT NIGHT...MAINLY VFR. SUB VFR IS POSSIBLE IN SCATTERED LATE
DAY AND EVENING SHOWERS/TSTMS.
.SUN-TUE...VFR.
&&
.MARINE...
WITH A WEAK SURFACE TROUGH DEVELOPING THIS AFTERNOON THE WIND
SHIFTS BACK TO SOUTHWEST AND SEAS OF 3 TO 4 FT ON THE OCEAN
WATERS.
A FEW GUSTS TO 20 KT ARE POSSIBLE THIS AFTERNOON...OTHERWISE...TRANQUIL
CONDS ON TAP FOR THE DAY. THIS EVENING...SEAS WILL BUILD TO 5 FT
ON THE EASTERN OCEAN WATERS...SO WILL ISSUE A SCA FOR HAZARDOUS
SEAS FOR TONIGHT. CONDS ON THE EASTERN OCEAN WATERS WILL SUBSIDE
BELOW SCA BY SATURDAY MORNING. SUB-ADVISORY CONDS ON TAP FOR
SATURDAY.
ISOLATED TSTMS ARE POSSIBLE THIS EVENING AS A WEAK SHORTWAVE
SLIDES THROUGH THE REGION. ANOTHER SHORTWAVE WILL BRING SCATTERED
SHOWERS WITH ISOLATED THUNDERSTORMS SATURDAY AFTERNOON.
A WEAK COLD FRONT WILL MOVE SOUTH ACROSS THE FORECAST WATERS
SATURDAY NIGHT. HIGH PRESSURE BUILDS IN FROM THE WEST SUNDAY
THROUGH TUESDAY AND MOVES EAST OF THE FORECAST WATERS TUESDAY
NIGHT AS A FRONTAL SYSTEM APPROACHES FROM THE WEST. SEAS AND WIND
ARE EXPECTED TO REMAIN BELOW SMALL CRAFT ADVISORY LEVELS SATURDAY
NIGHT THROUGH TUESDAY NIGHT.
&&
.HYDROLOGY...
SCATTERED SHOWERS WITH ISOLATED THUNDERSTORMS ARE POSSIBLE ONCE
AGAIN ON SATURDAY.
THE NEXT CHANCE FOR ORGANIZED WIDESPREAD RAINFALL WILL BE
WEDNESDAY AND THURSDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS
EVENING TO 6 AM EDT SATURDAY FOR ANZ350.
&&
$$
SYNOPSIS...MPS/MET
NEAR TERM...MPS/TONGUE
SHORT TERM...MPS/TONGUE
LONG TERM...MET
AVIATION...SEARS/JM
MARINE...MPS/MET
HYDROLOGY...MPS
AREA FORECAST DISCUSSION
NWS MIAMI FL
745 PM EDT SAT AUG 3 2013
.AVIATION...
ONLY LIGHT TO MODERATE SHRAS REMAIN ACROSS MAINLY THE LAKE
OKEECHOBEE REGION THIS EVENING. LATEST HRRR AND LOCAL SHORT RANGE
MODELS SHOW THIS ACTIVITY DIMINISHING IN COVERAGE OVER THE NEXT
FEW HOURS. THEREFORE DID NOT PREVAIL ANY PRECIPITATION AT ANY
SITE OVERNIGHT...ALTHOUGH COULD NOT RULE OUT AN ISOLATED BRIEF
SHRA AT ANY SITE THROUGH THE REMAINDER OF THIS EVENING.
OTHERWISE...WINDS ARE EXPECTED TO BE NEARLY CALM THROUGH THE NIGHT
AND MAINLY LIGHT OUT OF THE SOUTHWEST DURING THE DAY SUNDAY...WITH
A WEAK EAST COAST SEA BREEZE DEVELOPING BY EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 725 PM EDT SAT AUG 3 2013/
UPDATE...
THUNDERSTORM ACTIVITY HAS DIMINISHED ACROSS SOUTH FLORIDA,
HOWEVER, THERE STILL ARE SOME SHOWERS IN THE AREA ESPECIALLY
ACROSS THE NORTHERN AREAS. THESE SHOWERS WILL LINGER THROUGH THE
EVENING HOURS BEFORE DIMINISHING. A LIGHT SOUTHWESTERLY STEERING
FLOW WILL CONTINUE THROUGH THE REST OF THE WEEKEND. SCATTERED
SHOWERS AND THUNDERSTORMS WILL REDEVELOP TOMORROW AFTERNOON AND
EVENING ESPECIALLY ACROSS INTERIOR AND EAST COAST SECTIONS. A DEEP
LAYER RIDGE WILL BUILD BACK INTO THE REGION BY THE MIDDLE OF NEXT
WEEK. THIS WILL ALLOW FOR EASTERLY FLOW TO RETURN WHICH WILL FOCUS
THE SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS INTERIOR AND WEST
COAST SECTIONS.
PREV DISCUSSION... /ISSUED 210 PM EDT SAT AUG 3 2013/
SHORT TERM (TONIGHT-MONDAY NIGHT)...
GLOBAL MODELS INITIALIZED QUITE WELL THIS MORNING SHOWING THE WEAK
SURFACE CIRCULATION ASSOCIATED WITH T.D. DORIAN LOCATED OFF THE
NORTHEAST FLORIDA PENINSULA COAST AND A WEAK MID LEVEL TROUGH WHICH
WAS LOCATED JUST EAST OF MLB. A TROUGH BOUNDARY EXTENDS SOUTHWEST OF
THIS FEATURE ACROSS SOUTH FLORIDA AND ALL OF THIS HAD EARLIER HELPED
ENHANCE A LARGE CLUSTER OF CONVECTION ACROSS THE ATLANTIC WATERS
MOSTLY NORTH OF OUR AREA ALONG WITH DIURNAL CYCLE ACTIVITY ACROSS
THE MAINLAND. THE CONVECTION OVER THE WATERS HAS BEGUN TO DIMINISH
AT THIS POINT. THE MODELS ARE ALSO IN GOOD AGREEMENT THAT A DIGGING
MID LEVEL TROUGH INTO THE EASTERN U.S. WILL PUSH A COLD FRONT INTO
THE SOUTHEAST STATES THIS EVENING WHICH WILL PICK UP DORIAN AND LIFT
IT TO THE NORTHEAST BECOMING ABSORBED INTO THE MAIN TROUGH. AT THE
SAME TIME, THE WEAK TROUGH BOUNDARY ACROSS SOUTH FLORIDA WILL ALSO
LIFT TO THE NORTHEAST THIS EVENING SO THE CONVECTION THIS AFTERNOON
DEVELOPING MOSTLY DUE TO THE INFLUENCE OF THE TROUGH AND DIURNAL
HEATING WILL DIMINISH RAPIDLY AFTER SUNSET.
SOUTH FLORIDA WILL THEN ENTER A STAGNANT WEATHER PATTERN FOR THE
REMAINDER OF THIS PERIOD. THE LOW LEVEL RIDGE WILL REMAIN ACROSS THE
FLORIDA STRAITS AS A LARGE MID LEVEL TROUGH MOVES LITTLE ACROSS THE
EASTERN STATES AND A STRONG MID LEVEL RIDGE CENTERED OVER TEXAS WILL
BUILD EAST INTO THE EASTERN GULF OF MEXICO AND THE FLORIDA
PENINSULA. THIS WILL YIELD A WESTERLY STEERING FLOW WITH A
NORTHERLY FLOW IN THE UPPER LEVELS OF THE ATMOSPHERE WHILE
MAINTAINING PWAT OF AROUND TWO INCHES OR SLIGHTLY LESS AND VERY
LITTLE CHANGE TO THE 500MB TEMPERATURES WHICH WILL RUN AROUND -6
CELSIUS. THIS IS RIGHT AT THE NORMAL VALUES FOR EARLY AUGUST. SO
POPS WILL AVERAGE CLOSE TO AUGUST AVERAGES BUT WITH THE HIGHEST
CHANCES OF RAINFALL OVER THE INTERIOR AND EAST COAST METRO AREAS.
FORECAST SOUNDINGS SHOW THE PRIMARY THREAT WILL BE AFTERNOON
THUNDERSTORMS WITH THE CAPABILITY OF PRODUCING SOME ISOLATED STRONG
WIND GUSTS AND THE TYPICAL BRIEF HEAVY DOWNPOURS ALONG WITH FREQUENT
LIGHTNING STRIKES.
LONG TERM (TUESDAY-SATURDAY)...
TUESDAY WILL BE A TRANSITIONAL DAY AS IT APPEARS NOW WITH THE LARGE
SCALE TROUGH OVER THE EAST LIFTING TO THE EAST WHICH WILL ALLOW FOR
A DEEP LAYER RIDGE TO BUILD ACROSS NORTH FLORIDA. SO AS THIS BEGINS
TO OCCUR, THE CONVECTION WILL BE MOSTLY DRIVEN BY SEA BREEZE
BOUNDARIES ON TUESDAY. THEN, AS THE RIDGE BECOMES FIRMLY DEVELOPED
BY WEDNESDAY THROUGH THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND
THE HIGHEST CHANCES FOR RAIN WILL REVERT TO THE INTERIOR AND
SOUTHWEST COAST. OF COURSE, THERE IS ALWAYS GREATER UNCERTAINTY BY
DAYS 6 AND 7 SO WILL MAINTAIN A BROAD BRUSH CHANCE OF THUNDERSTORMS
FOR ALL AREAS AND WILL ADJUST AS THE FORECAST BECOMES MORE FINE
TUNED.
MARINE...
DUE TO A SOUTHWEST WIND, SEAS WILL BE TRANQUIL THROUGH EARLY NEXT
WEEK OUTSIDE OF STRONGER THUNDERSTORMS WHICH COULD MAKE FOR
HAZARDOUS LOCAL SEAS IN GUSTY WINDS. THE WIND WILL BECOME EAST AT
MOSTLY LESS THAN 15 KNOTS BY LATE TUESDAY THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 75 93 79 92 / 20 40 10 50
FORT LAUDERDALE 75 91 78 89 / 20 30 10 50
MIAMI 76 91 78 91 / 20 30 10 50
NAPLES 77 91 77 90 / 20 30 10 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...55/CWC
AVIATION/RADAR...10/CD
AREA FORECAST DISCUSSION...UPDATED AVIATION AND MARINE DISCUSSION
NWS MELBOURNE FL
1015 AM EDT FRI AUG 2 2013
.DISCUSSION...
CURRENT-THIS AFTERNOON...
PRIMARY CONCERN WILL BE THE TROUGH OF LOW PRESSURE BETWEEN THE
NORTHERN BAHAMA ISLANDS AND THE MARTIN AND SAINT LUCIE COUNTY COAST
AS IT INITIALLY MOVES SLOWLY NORTH NORTHWEST TODAY THEN NORTH
NORTHEAST AND AWAY FROM THE FLORIDA EAST COAST OVERNIGHT. RADAR WAS
DETECTING MOST OF THE SHOWERS AND ANY STORMS EAST OF THE TROUGH BUT
WRAP AROUND SHOWERS WILL PERIODICALLY IMPACT THE EAST CENTRAL
FLORIDA COAST THE REST OF TODAY. VISIBLE SATELLITE LOOP IS SHOWING
MOSTLY CLEAR SKIES OVER MOST OF EAST CENTRAL THAT IS AWAY FROM THE
COAST. WEAK PRESSURE GRADIENT AND FULL SUN WILL ALLOW FOR BOTH THE
EAST AND WEST COAST SEA BREEZES TO FORM AND PUSH INLAND THIS
AFTERNOON. LOCAL WRF AND RUC MODELS ARE TRYING TO SHOW LATE
AFTERNOON EAST AND WEST COAST SEA BREEZE COLLISIONS OVER LAKE COUNTY.
THE CURRENT 30 POP AT THE COAST INCREASING TO AROUND 50 OVER LAKE
COUNTY STILL LOOKS REASONABLE BASED ON SEA BREEZE COLLISIONS.
MOST SIGNIFICANT CHANGES TO THE AFTERNOON FORECAST WILL BE THE WINDS.
PREVIOUS DISCUSSION
TODAY...COMPLEX PATTERN EVOLVING ACROSS THE PENINSULA TODAY AS THE
NORTHERN STREAM UPPER LEVEL SHORTWAVE LIFTS OFF TO THE NORTHEAST.
ALSO BECOMING A PLAYER ARE THE RECENTLY REINVIGORATED REMNANTS OF
DORIAN NOW A STRONG TROUGH OR WEAK LOW NEAR ANDROS ISLAND IN THE
NORTHWESTERN BAHAMAS.
MODELS HAVE VARIOUS DEPICTIONS OF THE STRENGTH OF ANY LOW LEVEL
CIRCULATION ASSOCIATED WITH THIS FEATURE...BUT ALL KEEP THE STRONGER
WINDS/HEAVIEST RAIN ON ITS EASTERN FLANK. RIGHT NOW NHC HAS A 40
PERCENT CHANCE OF THIS AREA RE-DEVELOPING INTO A TROPICAL CYCLONE IN
THE NEXT 48 HOURS...WITH ITS PROXIMITY TO LAND...THE UPPER LEVEL
TROUGH JUST TO OUR NORTH AND...LACK OF ORGANIZATION WORKING AGAINST
IT. REGARDLESS OF DEVELOPMENT...THE STRONG TROUGH/WEAK LOW WILL MOVE
NORTHWEST TOWARDS THE SE FLORIDA COAST TODAY BEFORE SWINGING
NORTHWARDS TO PARALLEL THE EAST CENTRAL FLORIDA COAST TODAY AND
TONIGHT.
THE EXPECTED LOCATION OF THE LOW WILL PUT MOST OF EAST CENTRAL
FLORIDA WILL BE UNDER WHAT GENERALLY IS UNFAVORABLE NORTH-NORTHEAST
FLOW. HOWEVER...THE FLOW WILL REMAIN LIGHT ENOUGH FOR THE WEST COAST
SEA BREEZE TO DEVELOP AND MOVE INLAND LATE IN THE AFTERNOON. WATER
VAPOR SATELLITE SHOWS COMPARATIVELY DRIER AIR WRAPPING AROUND THE
NORTH AND WESTERN PERIPHERY OF THE CIRCULATION THIS MORNING...WHICH
WILL PIVOT INTO THE REGION THIS AFTERNOON...SHUNTING THE MOISTURE
ASSOCIATED WITH THE NORTHERN TROUGH FURTHER WEST. MODELS ARE ALL
UNANIMOUS IN KEEPING THE BEST MOISTURE/STRONGER WINDS ASSOCIATED
WITH THE REMNANTS ON THE EASTERN SIDE OF THE LOW AS IT LIFTS
NORTHWARDS. STILL...WITH WEAK TO NON EXISTENT STEERING FLOW HEAVY
RAIN WILL BE A CONCERN ESPECIALLY WITH THE LATE DAY COLLISION OF THE
SEA BREEZES. THE TREASURE COAST MAY ALSO BECOME A CONCERN FOR HEAVY
RAIN DEPENDING ON HOW FAR NORTHWEST THE MOISTURE PLUME ASSOCIATED
WITH THE LOW TRACKS BEFORE IT TURNS NORTHERLY.
THE EAST COAST SEA BREEZE WILL BE ENHANCED BY THE ONSHORE FLOW AND
QUICKLY MOVE INLAND...LIMITING RAIN CHANCES FOR MOST OF THE COAST.
THE EXCEPTION WILL BE ACROSS THE TREASURE COAST WHERE PROXIMITY TO
THE WEAK LOW WILL KEEP THE POSSIBILITY FOR ONSHORE MOVING SHOWERS
AND STORMS THROUGH THE DAY. THE BEST RAIN CHANCES WILL BE OVER THE
INTERIOR WEST OF THE ORLANDO METRO LATE THIS AFTERNOON AND EVENING.
MAV GUIDANCE SEEMS A LITTLE HIGH WITH AFTERNOON TEMPS GIVEN THE
EXPECTED ONSHORE FLOW SO HAVE KEPT THEM IN THE UPPER 80S ALONG THE
COAST AND LOW 90S INLAND.
TONIGHT...WEAK LOW LIFT FURTHER UP THE COAST AND OFF TO THE
NORTHEAST BRINGING FLOW AROUND TO THE WEST-SOUTHWEST BY THE EVENING
HOURS. THIS MAY KEEP A FEW SHOWERS AND STORMS ACROSS LAKE
COUNTY...THE KISSIMMEE RIVER...AND ALONG THE LAKE OKEECHOBEE COAST
THROUGH THE LATE EVENING HOURS.
SATURDAY...THE REMNANTS OF DORIAN SHOULD ROUND THE PERIPHERY OF THE
MID LVL RIDGE OVER THE ATLC AND BE ACROSS THE OFFSHORE WATERS EARLY
SATURDAY AND PULL FURTHER NE AWAY FROM THE AREA IN THE AFTERNOON.
LIGHT LOW LVL W/SW FLOW AND LIGHT WEST TO NW MID LYR FLOW SHOULD
ALLOW SCATTERED CONVECTION TO DEVELOP SATURDAY AFTERNOON WITH THE
DEVELOPING EAST COAST SEA BREEZE ACROSS THE COASTAL COUNTIES. FOR
NOW WILL DISCOUNT THE STRONGER NAM WIND FIELDS AND DEEPER MOISTURE
ON THE WEST SIDE OF DORIAN BUT STILL KEEP SHOWER/T-STORM CHANCES
AROUND 40 PCT.
SUNDAY...MID LVL RIDGE WILL EXTEND FROM THE NRN GULF COAST TO THE
WRN FLORIDA PENINSULA WITH SOME MID LVL DRYING LOWERING PWATS TO
AROUND 1.7 INCHES ACROSS CENTRAL SECTIONS OF THE FORECAST AREA. GFS
MOS POPS HAVE DROPPED BELOW 20 PCT BUT NAM MOS IS AROUND 40 PCT.
SOME MID TO LATE AFTERNOON SHOULD DEVELOP ON THE EASTERN SIDE OF THE
PENINSULA BUT COVERAGE SHOULD BE LOWER THAN SATURDAY. WILL LOWER
POPS TO 30 PCT FOR NOW AND KEEP AN EYE ON MOISTURE TRENDS WITH
UPCOMING MODELS. THE MAIN STORY FOR THE WEEKEND WILL BE THE HEAT IN
AREAS THAT DO NOT SEE ANY RELIEF FROM AFTERNOON STORMS. HIGHS SHOULD
HIT THE MID 90S ACROSS THE INTERIOR AND LOWER 90S ACROSS THE COASTAL
COUNTIES.
&&
.AVIATION...TEMPO MVFR CONDITIONS ALONG THE COAST AS SHOWERS AND LOW
STRATOCU MOVE NORTH TO SOUTH ALONG THE COAST THIS AFTERNOON.
TEMPO MVFR CONDITIONS INTERIOR SITES STARTING AROUND THE INTERSTATE
95 CORRIDOR EARLY AFTERNOON...16Z-18Z...THEN WORKING THEIR WAY WEST
ACROSS THE ORLANDO AREA...18Z-21Z...AND LAKE COUNTY MID TO LATE
AFTERNOON...21Z-01Z...BEFORE WINDING DOWN FOR THE NIGHT
PREVIOUS
ONSHORE FLOW AROUND THE PERIPHERY OF THE REMNANTS OF
DORIAN MOVING THROUGH THE BAHAMAS AND SE FLORIDA COAST TODAY WILL
QUICKLY PUSH THE EAST COAST SEA BREEZE INLAND WITH SCT SHRA/TSRA
POSSIBLE AT ALL TERMINALS 16Z-19Z...BEFORE SEA BREEZE SHIFTS WELL
INLAND. BEST COVERAGE WILL BE WEST OF KMCO...VCNTY KVVG-KLEE-KISM
AFTER 21Z.
&&
.MARINE...
CURRENT-THIS AFTERNOON...BUOY 009 WAS RECORDING NORTHEAST WINDS
AROUND 5 KNOTS WHILE THE REST OF THE BUOYS THAT HAD WIND RECORDING
INSTRUMENTS ON THEM WERE RECORDING WEST TO NORTHWEST WINDS AROUND 5
KNOTS. ALL THE WAVE HEIGHT RECORDING BUOYS WERE INDICATING 2 FOOT
SEAS WITH A WAVE PERIOD BETWEEN 8 AND 9 SECONDS.
EXPECT THAT THE NEARSHORE WINDS WILL SHIFT ONSHORE AND REMAIN AROUND
10 KNOTS THIS AFTERNOON AS THE EAST COAST SEA BREEZES FORMS AND
START WORKING THEIR WAY WEST.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...THE EXACT WIND FORECAST FOR TODAY WILL
DEPEND ON WHAT FORM THE REMNANTS OF DORIAN TAKE AS THEY MOVE THROUGH
THE BAHAMAS AND SE FLORIDA COAST TODAY AND TONIGHT. OVERALL THE
STRONGEST WINDS ARE EXPECTED TO REMAIN WELL OFFSHORE...WITH LIGHT
SOUTH-SOUTHEAST FLOW THIS MORNING BECOMING EAST-NORTHEAST AROUND
10KTS THIS AFTERNOON. WATERS SOUTH OF SEBASTIAN INLET WILL BECOME
MORE SOUTHERLY AS THE FEATURE LIFTS NORTH THIS EVENING...WITH
EVENTUALLY ALL THE WATERS BECOMING WEST-SOUTHWEST LATE TONIGHT. SEAS
2-3 FEET. COVERAGE OF SHOWERS AND STORMS WILL BE HIGHEST OVER THE
OFFSHORE WATERS AND NEARSHORE WATERS SOUTH OF SEBASTIAN INLET.
SATURDAY...DISTURBED WEATHER IS FORECAST ACROSS THE OFFSHORE WATERS
TO START THE DAY AS THE REMNANTS OF DORIAN MOVE NWD AROUND THE
RIDGE. HAVE TRENDED TOWARD WEAKER GFS WINDS WITH SEAS 2-3 FT NEAR
SHORE AND 3 FT OFFSHORE. SUNDAY...EXPECT WEST TO SOUTHWEST WINDS TO
10 KNOTS AND SEAS 2 FT NEAR THE COAST AND 3 FT OFFSHORE. SW WINDS
EARLY IN THE WEEK WILL BECOME SE BY WED/THU WITH MOST OF THE
CONVECTIVE ACTIVITY OVER THE MAINLAND IN THE AFTERNOON BY MID WEEK.
SEAS MAINLY 2-3 FT.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
FORECASTS...WIMMER
IMPACT WX...BRAGAW
AREA FORECAST DISCUSSION
NWS MIAMI FL
148 AM EDT FRI AUG 2 2013
.AVIATION...
VERY TRICKY TAF FORECAST FOR TODAY. A TROUGH OF LOW PRESSURE WAS
SLOWLY DEVELOPING OVER THE ATLANTIC IN BETWEEN THE BAHAMAS AND
SOUTH FLORIDA. THIS FEATURE IS FORECAST TO TRACK VERY NEAR THE
COAST OR POSSIBLY EVEN OVER THE REGION LATER TODAY...AND THIS HAS
MAJOR IMPLICATIONS ON THE WIND DIRECTION/SPEED AS WELL AS RAINFALL
FOR THE EAST COAST TAF SITES.
EXPECT LIGHT WINDS TO CONTINUE THROUGH THE EARLY MORNING HOURS
TODAY...AND A FEW SHOWERS MAY MOVE TOWARDS SHORE AND AFFECT THE
EAST COAST TAF SITES. A WEAK EAST COAST SEA BREEZE MAY DEVELOP BY
LATE MORNING/EARLY AFTERNOON WITH SHOWERS AND STORMS NEAR THE TAF
SITES. THE TROUGH OF LOW PRESSURE OFF THE COAST MAY ALSO TRACK
CLOSER TO THE REGION...AND HEAVY RAIN/THUNDERSTORMS COULD AFFECT
SOME OF THE EAST COAST TERMINALS IN THE AFTERNOON. THE HIGHEST
PROBABILITY MAY BE TOWARDS KPBI. FOR KAPF...SHOWERS AND STORMS MAY
REMAIN MAINLY INLAND OF THE TAF SITE THIS AFTERNOON...BUT KEPT
VCSH IN THE TAF. LIGHT WINDS ARE EXPECTED AGAIN TONIGHT ACROSS
THE REGION.
&&
.PREV DISCUSSION... /ISSUED 811 PM EDT THU AUG 1 2013/
UPDATE...
SHOWERS AND THUNDERSTORMS HAVE BECOME MOSTLY CONFINED TO THE WEST
COAST AND ADJACENT WATERS. THERE ARE SOME ISOLATED SHOWERS OVER
THE ATLANTIC WATERS AS WELL. THE HRRR CONTINUES TO SHOW ISOLATED
TO SCATTERED ACTIVITY THROUGH THE OVERNIGHT HOURS OVER THE
ATLANTIC WATERS. IT ALSO SHOWS THE SHOWERS, AND OR ANY
THUNDERSTORMS, WEAKENING AS THEY MOVE ONSHORE. POPS HAVE BEEN
ADJUSTED SOMEWHAT TO REFLECT THIS PATTERN.
AVIATION...
HIGHER THAN USUAL DEGREE OF UNCERTAINTY IN THE 0Z TAF
ISSUANCES...AS THE FORECAST WILL BE IMPACTED BY THE EVOLUTION OF
THE REMNANTS OF TROPICAL STORM DORIAN. THESE REMNANTS BECAME MORE
CONCENTRATED THIS AFTERNOON...THEN DIMINISHED THIS EVENING OVER
THE NORTHWEST BAHAMAS. GUIDANCE HAS THE SYSTEM CONTINUING
NORTHWEST OVERNIGHT...GRADUALLY TURNING NORTHWARD FRIDAY. THE NAM
TAKES CONVECTION ASSOCIATED WITH THE REMNANTS ONSHORE...WHEREAS
OTHER MODELS KEEP THE MOST ROBUST PRECIPITATION OVER ATLANTIC
WATERS...WITH ONLY SCATTERED ACTIVITY ON LAND. EVEN FOR
TONIGHT...SHOWERS IN THE WESTERN-MOST BAHAMAS ARE MOVING TOWARD
SOUTH FLORIDA...AND GUIDANCE OFFERS LITTLE CONSENSUS ON WHETHER
THEY WILL HOLD TOGETHER.
LATEST TAFS KEEP VCSH THROUGH THE OVERNIGHT AND INTO
TOMORROW...BUT DID NOT CALL FOR INCREASING ACTIVITY OR VCTS FOR
FRIDAY AFTERNOON...DUE TO THE AFOREMENTIONED CONFIDENCE ISSUES.
WINDS SHOULD GENERALLY BE SOUTH OF EAST...BUT IF DORIANS REMNANTS
ARE FAIRLY ORGANIZED...WINDS ARE LIKELY TO BACK TO THE NORTHEAST
ON FRIDAY. SPEEDS SHOULD BE LESS THAN 15 KTS REGARDLESS OF THEIR
DIRECTION...EXCEPT IN AN NEAR PRECIPITATION.
PREV DISCUSSION... /ISSUED 248 PM EDT THU AUG 1 2013/
.MAIN IMPACTS FROM BAHAMAS LOW PRESSURE SYSTEM EXPECTED TO REMAIN
MOSTLY OFFSHORE...
DISCUSSION...
LOW PRESSURE SYSTEM OVER THE BAHAMAS CONTAINING THE REMNANTS OF
DORIAN HAVE BECOME MORE CONCENTRATED TODAY AS IT MOVES NORTHWEST.
SOUTH FLORIDA APPEARS TO BE UNDER A REGION OF UPPER-LEVEL
SUBSIDENCE AND ASSOCIATED DRIER AIR WHICH IS LIMITING THE
DEVELOPMENT OF THE CONVECTION OVER THE PENINSULA SO FAR THIS
AFTERNOON. IN FACT, SATELLITE IMAGERY IS SHOWING SEVERAL ARC-
SHAPED CLOUD PATTERNS SPREADING WESTWARD OVER THE WATERS OFF THE SE
FLORIDA COAST FROM THE CLUSTER OF STORMS OVER THE BAHAMAS...A
USUAL SIGN OF SUBSIDENCE PREVENTING CONVECTION FROM GETTING
ORGANIZED OR VERY STRONG AS THESE SHOWERS APPROACH THE FLORIDA
COAST. FOR THE REST OF THE AFTERNOON INTO THE EARLY EVENING,
GREATEST COVERAGE OF SHOWERS/TSTMS WILL BE OVER THE INTERIOR IN
A TYPICAL EAST FLOW PATTERN
MODELS APPEAR TO HAVE A DECENT HANDLE ON THE LOW PRESSURE AREA AND
ARE REASONABLY CONSISTENT IN KEEPING THE BULK OF THE ASSOCIATED
WEATHER OFFSHORE TONIGHT AND FRIDAY. THE GFS IS THE ONLY MODEL
WHICH BRINGS THE LOW LEVEL CIRCULATION (850 MB) ONSHORE THE EAST
COAST LATE TONIGHT AND EARLY FRIDAY, WITH THE NAM AND ECMWF
KEEPING IT OFFSHORE OVER THE STRAITS. DUE TO THE UNCERTAINTY IN
THE LOCATION OF THE LOW LEVEL CIRCULATION AND HOW CLOSE IT MAY
COME TO THE EAST COAST, WILL INDICATE SCT TSTMS (30%) FOR EAST
COAST LATE TONIGHT DESPITE MODELS NOT BEING ENTHUSIASTIC ABOUT
PRECIPITATION COVERAGE. THE LOW IS EXPECTED TO MOVE NORTH NEAR OR
JUST OFF THE COAST FRIDAY ALONG THE WESTERN PERIPHERY OF THE
ATLANTIC SUBTROPICAL RIDGE. AS MENTIONED ABOVE, THIS WOULD KEEP
MOST OF THE ASSOCIATED SHOWERS/TSTMS/GUSTY WINDS OFFSHORE, BUT A
GENERAL INCREASE IN MOISTURE ACROSS SOUTH FLORIDA ALONG WITH THE
PRESENCE OF A LOW/MID LEVEL TROUGH WILL LEAD TO SCATTERED MAINLY
AFTERNOON TSTMS. VERY HEAVY RAINFALL AND MINOR FLOODING ARE THE
MAIN THREATS WITH THE STORMS ON FRIDAY DUE TO THE EXPECTED SLOW
STORM MOTION.
FOR THE WEEKEND...THE LOW PRESSURE IS FORECAST TO MOVE NORTH OF THE
AREA FRIDAY NIGHT, LEAVING BEHIND A BUILDING LOW/MID LEVEL RIDGE
OVER SOUTH FLORIDA. THE ORIENTATION OF THE RIDGE RIGHT OVER SOUTH
FLORIDA WILL LEAD TO LIGHT SW/W WINDS AND FOCUS SCATTERED AFTERNOON
TSTMS TO THE INTERIOR/LAKE OKEECHOBEE AND PALM BEACH COUNTY AREAS
ON SATURDAY, AND GENERALLY INTERIOR AND EAST ON SUNDAY. TEMPERATURES
WILL ALSO BE ON THE RISE, PARTICULARLY THE DAYTIME HIGHS INTERIOR
AND EAST. SUNDAY COULD SEE HIGHS IN THE LOW/MID 90S EVEN INTO
PARTS OF THE EAST COAST METRO WITH MAXIMUM HEAT INDEX VALUES
100-105F JUST ABOUT EVERYWHERE, WITH ISOLATED POCKETS OF 105-109F
POSSIBLE IN THE EVERGLADES.
THE WEEKEND PATTERN LOOKS TO REMAIN IN PLACE INTO EARLY NEXT WEEK,
WITH HOT TEMPERATURES AND AFTERNOON TSTMS FOCUSING INTERIOR AND
EAST. BY WEDNESDAY, MODELS SHOW SOME DIFFERENCES WITH THE GFS
SHOWING EASTERLY FLOW RETURNING AND THE ECMWF SHOWING A LINGERING
LOW/MID LEVEL LOW OVER THE EASTERN GULF OF MEXICO. THE ECMWF
SCENARIO IS WETTER/STORMIER THAN THE GFS FOR MIDDLE OF NEXT WEEK,
BUT STILL PLENTY OF TIME TO EVALUATE TRENDS.
AVIATION...
FOR THIS AFTERNOON...BANDS OF SHOWERS WILL CONTINUE TO MOVE WESTWARD
ACROSS THE ATLANTIC WATERS AND AFFECT THE EAST COAST TAF SITES FROM
TIME TO TIME BUT MAINLY VFR CONDITIONS ARE EXPECTED TO
PREVAIL...ALTHOUGH AN ISOLATED THUNDERSTORM CANNOT BE RULED OUT. FOR
TERMINAL KAPF...VCTS IS ASSIGNED BY 19Z WITH PERIODS OF SUB-VFR
CONDITIONS POSSIBLE AND VERY BRIEF PERIODS OF IFR CONDITIONS
POSSIBLE WITH THE OCCURRENCE OF SHOWERS AND THUNDERSTORMS ACROSS THE
WESTERN PENINSULA THIS AFTERNOON AND EARLY EVENING.
FOR TONIGHT INTO FRIDAY...THE COMBINATION OF THE REMNANTS OF DORIAN
AND AN UPPER LOW MOVING IN TANDEM WITH IT HAS CREATED A SURFACE
TROUGH AND AN AREA OF CLOUDINESS ACROSS THE CENTRAL AND NORTHWEST
BAHAMAS...WITH SHOWERS AND THUNDERSTORMS IN THESE AREAS. ALTHOUGH
THE LOW PRESSURE AND ASSOCIATED CONVECTION IS FORECAST TO REMAIN
TO THE EAST OF SOUTH FLORIDA THROUGH THE TAF PERIOD...BANDS OF
SHOWERS WILL CONTINUE TO AFFECT THE EAST COAST TAF SITES TONIGHT
INTO FRIDAY WITH ALL EAST COAST TERMINALS ASSIGNED VCSH THROUGH
THIS PERIOD.
MARINE...
MODERATE EASTERLY WINDS TODAY WILL DECREASE TONIGHT AND BECOME
S/SW AS THE LOW PRESSURE AREA MOVES NEAR THE LOCAL ATLANTIC
WATERS. UNLESS THE SYSTEM DEVELOP, WHICH IS A LOW POSSIBILITY AT
THIS TIME, WINDS WILL REMAIN LIGHT WITH THE PRIMARY CONCERN BEING
GUSTY WINDS IN AND NEAR THE SHOWERS/TSTMS OVER THE ATLANTIC. THE
LIGHT S/SW FLOW WILL CONTINUE THROUGH THE UPCOMING WEEKEND AND
LIKELY INTO EARLY NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 89 78 91 79 / 50 30 40 20
FORT LAUDERDALE 89 77 91 78 / 50 30 30 20
MIAMI 90 77 91 78 / 50 30 30 20
NAPLES 90 76 91 76 / 40 20 30 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...57/DG
AVIATION/RADAR...84/AK
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
253 PM CDT FRI AUG 2 2013
.DISCUSSION...
248 PM CDT
THIS AFTERNOON AND TONIGHT...
A SURFACE TROUGH IS DRAPED FROM NORTHERN LAKE MICHIGAN SOUTHWEST
ACROSS SOUTHERN WISCONSIN AND INTO NORTHWESTERN ILLINOIS. AGITATED
CU FIELD HAS DEVELOPED OUT AHEAD OF THE TROUGH FROM DOWNTOWN CHICAGO
WEST ACROSS FAR NORTHERN LA SALLE COUNTY AND SOUTHERN LEE COUNTY.
HAVE RECENTLY SEEN THE FIRST RETURNS ON RADAR DEVELOPING IN THIS
AREA WHICH LATEST SPC MESOANALYSIS SHOWS AS AN AXIS OF 1500 J/KG
UNCAPPED MLCAPE. DEEP LAYER SHEAR IS MARGINAL AT THE MOMENT WITH
ABOUT 30 KTS...BUT THIS NUMBER MAY INCREASE AS WE HEAD INTO THE LATE
AFTERNOON AND EARLY EVENING AS MID LEVEL DISTURBANCE CURRENTLY OVER
NORTH CENTRAL IOWA APPROACHES. THIS FEATURE WILL ALSO INCREASE THE
BROAD SCALE ASCENT OVER THE AREA AND SHOULD LEAD TO AN INCREASE IN
THUNDERSTORM COVERAGE AS WELL AS ORGANIZATION. THERE IS CERTAINLY AN
INCREASED CONCERN FOR SEVERE WEATHER WHICH WILL HAVE TO BE MONITORED
OVER THE NEXT SEVERAL HOURS...ESPECIALLY AS WE GET A LITTLE BETTER
MID LEVEL LAPSE RATES OVER THE AREA AND THE AFOREMENTIONED SHEAR.
THE FOCUS SHOULD SHIFT SOUTH THROUGH THE EVENING. THERE WILL
SOME TRAINING ALONG THE BOUNDARY AS IT SAGS SOUTH THIS EVENING
LEADING TO LOCALIZED HEAVY RAIN AMOUNTS...THOUGH LATEST GUIDANCE
HAS SHIFTED THE FOCUS OF THE LOW LEVEL JET FARTHER EAST OF US
OVERNIGHT...SO APPEARS FOR NOW THAT THE THREAT FOR HEAVY RAIN
OVERNIGHT WILL ALSO BE FARTHER EAST.
SATURDAY THROUGH MONDAY...
SURFACE HIGH WILL BUILD SOUTHEAST FROM THE CANADIAN PRAIRIES...OVER
LAKE MICHIGAN SUNDAY...THEN EAST TO THE MID APPALACHIAN RANGE MONDAY
AND SHOULD PROVIDE A RELATIVELY BENIGN PERIOD OF WEATHER. WE DO GET
A GLANCING BLOW OF COOLER H85 AIR WHICH BOTTOMS OUT 8-9C ON
SUNDAY OVER NORTHEAST PORTIONS OF THE CWA. CANNOT COMPLETELY RULE
OUT SOME DIURNALLY DRIVEN AFTERNOON SHOWERS...AND MODELS DO HINT
AT SEVERAL WEAK SHORTWAVE TROUGHS RIDING DOWN THE RIDGE....BUT
SEEMS MORE LIKELY THAT SUBSIDENCE ASSOCIATED WITH MODERATE MID
LEVEL HEIGHT RISES FROM THE H5 RIDGE BUILDING ACROSS THE AREA WILL
LIMIT CU GROWTH. NAM AND GFS SOUNDINGS BOTH INDICATE A SUBSIDENCE
INVERSION SETTING UP AROUND 750 MB THROUGH THE WEEKEND WHICH WILL
LIMIT THE DEPTH OF THE VERTICAL GROWTH AND SHOULD KEEP THE AREA
DRY.
THIS PERIOD WILL SEE TEMPERATURES WELL BELOW SEASONAL NORMS. AS
MENTIONED...H85 TEMPS BOTTOM OUT SUNDAY AND UPPER AIR CLIMATOLOGY
SHOWS THAT 75% OF THE TIME SURFACE TEMPS TOP OUT AT 76 OR COOLER
WITH H85 TEMPS LESS THAN AROUND 9C. THE ECMWF/GEM/GFS ALL SUPPORT
TEMPS IN THE 71-73 FOR CHICAGO AND 73-74 FOR ROCKFORD...THOUGH THE
NAM WITH ITS TYPICAL HIGH BIAS IS SEVERAL DEGREES WARMER. GIVEN THAT
EVEN MOS GUIDANCE IS CALLING FOR MID 70S...AND WE SHOULD CLOUD UP
SOME WITH COLD AIR CU GROWTH...FELT COMFORTABLE DROPPING TEMPS A
COUPLE MORE DEGREES SUNDAY...CLOSER TO THE BLEND OF RAW GUIDANCE.
TUESDAY AND WEDNESDAY...
WITH THE HIGH SHIFTING EAST OF THE AREA...AND LOW PRESSURE DEEPENING
ACROSS THE CENTRAL/NORTHERN PLAINS...RETURN FLOW INTO THE MID
MISSOURI AND MID MISSISSIPPI VALLEYS SHOULD ALLOW UPPER 60 TO LOW 70
DEWPOINTS TO OVERSPREAD THE AREA WITH MODERATE TO STRONG INSTABILITY
DEVELOPING. STRONG WESTERLIES ALOFT COULD SET THE STAGE FOR A SEVERE
WEATHER OUTBREAK SOMEWHERE NEARBY WITH CURRENT MODEL SOLUTIONS
SETTING THE STAGE JUST TO OUR WEST. WHILE IT`S DIFFICULT TO PIN DOWN
A SEVERE WEATHER THREAT THIS FAR OUT...MODELS ARE IN DECENT
AGREEMENT AND WILL HAVE TO WATCH TUESDAY AND WEDNESDAY CLOSELY.
TEMPERATURES SHOULD RETURN TO SEASONABLE...AND IF ANYTHING CURRENT
PROJECTIONS OF LOW 80S MAY BE A BIT TOO COOL. A COLD FRONT IS
PROJECTED TO PUSH OVER THE AREA WEDNESDAY NIGHT.
THURSDAY AND FRIDAY...
MODELS DIVERGE QUITE A BIT ON HOW FAR SOUTH TO PUSH THE FRONTAL
BOUNDARY. THE GFS PUSHES THE FRONT WAY SOUTH INTO THE SOUTHEASTERN
STATES BY FRIDAY WHILE THE ECMWF STALLS THE FRONT OUT INTO SOUTHERN
ILLINOIS WITH PRECIPITATION OVERRUNNING THE BOUNDARY INTO THE
SOUTHERN CWA. WHILE THE NORTH HALF OF THE CWA SHOULD BE DRY EITHER
WAY...SOUTH OF I-80 ITS LESS CERTAIN. GIVEN THAT THE GFS ENSEMBLE
MAINTAINS SOME QPF FARTHER NORTH THAN THE OPERATIONAL RUN...WILL
MAINTAIN SOME CHANCE FOR THUNDERSTORMS ACROSS THE SOUTHERN CWA LATE
IN THE WEEK.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* TIMING AND LOCATION OF NEW CONVECTION EXPECTED TO DEVELOP
EARLY- MID AFTERNOON.
* COLD FRONT PASSAGE THIS EVENING AND TONIGHT GRADUALLY VEERING
WINDS FROM WSW-WNW TO N-NNE BY DAYBREAK.
//DISCUSSION...UPDATED 18Z...
LATE NIGHT-EARLY MORNING CONVECTION HAD MOVED QUICKLY ESE AND
WEAKENED BY MID MORNING AS A SHORT WAVE MOVES INTO THE CENTRAL
GREAT LAKES.
LOSS OF SIGNIFICANT CLOUD COVER WITH DEPARTURE OF CONVECTION HAS
ALLOWED GOOD SURFACE HEATING. HEATING COMBINED WITH LOW LEVEL
MOISTURE ADVECTION INTO THE AREA /SURFACE DEW POINTS HAVE RISEN
FROM UPPER 50S TO UPPER 60S DURING THE MORNING/ IS LEADING TO
INCREASINGLY UNSTABLE CONDITIONS ACROSS THE AREA. A WEAK COLD
FRONT HAS BEEN GRADUALLY DROPPING SOUTHWARD ACROSS N CENTRAL IL
AND EXTREME SE WI DURING THE MORNING THOUGH WITH W WINDS AHEAD OF
IT AND FAIRLY LIGHT NW WINDS BEHIND THE CONVERGENCE AHEAD/ALONG
THE BOUNDARY IS MINIMAL.
WATER VAPOR SATELLITE LOOP SHOWING A SHORT WAVE/MCV OVER SD
MOVING THROUGH THE UPPER RIDGE OVER THE PLAINS. THIS FEATURE WILL
START TO TURN ESE AS IT MOVES PAST THE RIDGE AXIS TAKING IT
ACROSS IA THIS AFTERNOON AND THEN NW AND E CENTRAL IL THIS
EVENING.
HIGH RESOLUTION MODELS CONTINUE TO INDICATE MDW AND ORD BEING ON
THE NORTHERN EDGE OF WHERE THETA-E CONVERGENCE IS MAXIMIZED THIS
AFTERNOON AHEAD OF THE DISTURBANCE THOUGH WITH THE WEAK COLD
FRONT MOVING FURTHER SOUTHWARD INTO NE IL AND INTO AREA OF MAX
CAPE THIS AFTERNOON. RECENT VISIBLE SATELLITE SHOTS SHOWING
MODERATE CU DEVELOPING OVER NORTHERN IL INCLUDING AROUND THE ORD
AND MDW AREAS.
WITH CONTINUED DESTABILIZATION AND WEAK CONVERGENCE ALONG THE
COLD FRONT ANTICIPATE TS TO DEVELOP OVER THE CHI AREA BY MID
AFTERNOON... WITH THE MAIN AREA OF CONVECTION THEN SHIFTING A BIT
SOUTHWARD AS DEEP UPWARD ASSENT STARTS TO SPREAD ESE TO NW AND W
CENTRAL IL LATER IN THE AFTERNOON.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE TSRA DEVELOPING EARLY-MID AFTERNOON.
* MEDIUM CONFIDENCE IN LOCATION OF MAIN TS AREA THIS AFTERNOON.
* HIGH CONFIDENCE IN WINDS GRADUALLY VEERING THIS AFTERNOON
THROUGH OVERNIGHT.
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-00Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT-MONDAY...VFR LIKELY.
SATURDAY NIGHT-WEDNESDAY...LOW CHC OF TSRA.
THURSDAY...VFR LIKELY.
MTF
&&
.MARINE...
232 PM CDT
THUNDERSTORMS WILL PRIMARILY REMAIN OVER THE FAR SOUTHERN END OF THE
LAKE THIS AFTERNOON AND THE STRONGER STORMS MAY PRODUCE GALE FORCE
GUSTS. SOUTHWEST WINDS WILL BECOME NORTH TONIGHT BEHIND A COOL
FRONT...AND NORTH/NORTHWEST WINDS ARE EXPECTED ACROSS THE LAKE
THROUGH SUNDAY. HIGH PRESSURE MOVES OVER THE LAKE SATURDAY...AND
WINDS BECOME SOUTHEAST BY MONDAY MORNING. THE HIGH SHIFTS EAST OF
THE LAKE MONDAY AND ANOTHER LOW IS EXPECTED TO PASS NORTH OF THE
LAKE THROUGH ONTARIO MID NEXT WEEK. GUIDANCE STILL FEATURES
DIFFERENCES ON TIMING OF THE LOW...BUT TUESDAY NIGHT OR WEDNESDAY
LOOKS LIKE THE BEST TIME FRAME. GUIDANCE ALSO SUGGESTS ANOTHER LOW
MOVES IN FROM THE SOUTHWEST NEXT THURSDAY.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
249 PM CDT Fri Aug 2 2013
.DISCUSSION...
Issued 248 PM CDT Fri Aug 2 2013
Early afternoon surface map showing the cold front had crossed
much of Wisconsin, then extended westward across southern Iowa to
along the Kansas/Nebraska border. Precipitation so far has been
pretty sparse across the area, with just some high-based very
light showers tracking just south of the I-72 corridor.
Subsidence in the wake of morning convection in northern Illinois
actually allowed for a good deal of clearing across southeast Iowa
and northern Illinois, although diurnal cumulus has been filling
in rather quickly the last couple hours. The clearing helped to
get the air more unstable, with CAPE`s of around 2000 J/kg across
the northern third of the state with little cap, as evidenced by
scattered storms forming around 2 pm just ahead of the front from
Moline to Chicago.
The primary forecast concern in the short term is with the
convective chances over the next 18-24 hours. Rain chances in the
longer range are also a concern due to MCS potential through the
first half of next week.
SHORT TERM...Tonight through Sunday...
Morning model runs have significantly struggled with the
convective trends thus far, so confidence in this part of the
forecast is lower than normal. The most recent HRRR model appears
to be closest to reality, and shows that the broken line of
showers and storms to our north will be drifting across areas
along and north of I-74 into the evening. Scattered storms
currently in Missouri should track eastward as well, affecting
the remainder of the forecast area. Precipitable water values of
1.75 to 2 inches should help produce some heavy rain with the
stronger storms. Can`t rule out some gusty winds and hail as well,
but wind shear overall is rather weak in our area and anything
that does approach severe levels should be the pulse type.
Overnight, the NAM and GFS already have the precipitation on the
wane with a faster push to the cold front, while the ECMWF and
Canadian models linger the showers/storms most of the night with a
slower frontal passage. Have gone with the highest PoPs in the
evening, but kept healthy chances over most of the area overnight.
Not too many changes needed for Saturday, as the frontal boundary
should be through most of the area by midday. Have kept the
northwest CWA dry all day, and continued with all areas north of
I-72 dry by afternoon. All precipitation should be out of the area
by early evening, as high pressure builds southeast into the
Midwest, and cooler/less humid air can be expected the rest of the
weekend.
LONG TERM...Monday through Friday...
Upper level pattern looking fairly agreeable among the GFS and
ECMWF models, with initial northwest flow flattening as a strong
cutoff low sinks southward across Manitoba. GFS remains stronger
with the high keeping our area dry into Monday, while the ECMWF
keeps us on the periphery of the MCS track across Missouri. Have
limited any PoPs to the far southwest for Sunday night and even
then just kept them at 20 percent. Next shortwave on Tuesday
should help boot the high eastward, but convection along the Gulf
Coast will help rob some of the return moisture advection for a
time, so have held off on any decent rain chances until Tuesday
night. Getting into midweek, a surface boundary will become quasi-
stationary as it becomes parallel to the upper flow. The model
differences widen at this point, with the GFS pushing the boundary
through us by late Wednesday night and the ECMWF keeping it north
of the area until Thursday evening. The ultimate position and
associated convective chances will come down to timing of fast
moving shortwaves between the upper low and a sprawling upper high
over the southern U.S. For now have favored a bit of a more
southern push with a period of drier conditions Wednesday night
and Thursday with increasing PoPs again after that.
Geelhart
&&
.AVIATION...
ISSUED 1248 PM CDT Fri Aug 2 2013
Latest satellite imagery is beginning to show CU-field developing
along/ahead of an approaching cold front across Iowa into
north-central Illinois. Think scattered showers/storms will form
in this area over the next 2 to 3 hours...potentially impacting
the northern KILX terminals after 20z. Further south...convection
may not develop at the I-72 TAF sites until early evening...when
upper wave currently over the Dakotas begins to enhance lift
across the region. Since areal extent and timing of convection
remains in question...have opted to only include VCTS at the
terminals. With increasing lift and the front dropping slowly
southward toward the area...will maintain predominant showers in
the forecast through much of the evening into the first part of
the overnight hours. As boundary sags southward...southwesterly
winds this afternoon will eventually decrease and become
light/variable overnight. Main aviation concern later in the
forecast is whether or not MVFR ceilings will develop along/behind
boundary. Current satellite imagery does not support
this...however 12z NAM continues to suggest low ceilings. Will
therefore maintain a brief period of MVFR ceilings at around
2500ft after FROPA late tonight into early Saturday. After
that...clearing skies and light northeasterly winds are
anticipated Saturday morning.
BARNES
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
357 PM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 351 PM EDT FRI AUG 2 2013
A PAIR OF UPPER LEVEL DISTURBANCES WILL COMBINE WITH A COLD
FRONTAL BOUNDARY TO PRODUCE SHOWERS AND THUNDERSTORMS ACROSS MUCH
OF THE REGION TONIGHT INTO EARLY SATURDAY. THE BELOW NORMAL
TEMPERATURES WILL CONTINUE SUNDAY AND MONDAY BEHIND THIS FRONT
WITH MAINLY DRY CONDITIONS. A WARM FRONT WILL APPROACH THE AREA
TUESDAY BRINGING THE NEXT CHANCE OF SHOWERS AND THUNDERSTORMS.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 351 PM EDT FRI AUG 2 2013
PRIMARY SHORT TERM FORECAST CONCERN WILL BE ON CONVECTIVE POTENTIAL
TONIGHT INTO EARLY SATURDAY.
SHOWERS AND EMBEDDED THUNDERSTORMS HAVE SHIFTED EAST OF THE FORECAST
AREA THIS AFTERNOON AS ISENTROPIC UPGLIDE HAS WEAKENED THROUGH THE
DAY AND SHIFTED NORTH AND EAST OF LOCAL AREA. WATER VAPOR IMAGERY AT
18Z INDICATING A COUPLE OF SHORT WAVES OF INTEREST FOR TONIGHT/EARLY
SATURDAY. THE FIRST OF THESE SHORT WAVES CONTINUES TO DIG ACROSS THE
ARROWHEAD OF MINNESOTA ACROSS NORTHERN WISCONSIN. ANOTHER SMALLER
SCALE WAVE APPEARS TO BE KICKING OUT OF EASTERN NEBRASKA...WITH SOME
PRONOUNCED VEERING MID/UPPER LEVEL FLOW PER MERRIMAN PROFILER DATA
PAST HOUR BEHIND THIS SHORT WAVE. A 120 KNOT UPPER JET STREAK
DIGGING THROUGH BASE OF NORTHERN GREAT LAKES UPPER TROUGH WILL PLACE
LOCAL AREA INCREASINGLY IN MORE FAVORED RIGHT ENTRANCE REGION BY
LATE EVENING. VISIBLE SATELLITE IMAGERY TRENDS OVER PAST SEVERAL
HOURS HAVE BEEN TOWARD BUILDING CU ALONG PREFRONTAL TROUGH TYPE
FEATURE FROM THE QUAD CITIES INTO NORTHEAST ILLINOIS WHERE SFC DEW
POINTS HAVE POOLED INTO THE UPPER 60S TO AROUND 70. ABOVE MID/UPPER
LEVEL FORCING MECHANISMS SHOULD INTERACT WITH NARROW PREFRONTAL
TROUGH TYPE FEATURE TO INCREASE COVERAGE OF SCATTERED SHOWERS AND
THUNDERSTORMS LATE THIS AFTERNOON ACROSS NORTHEAST ILLINOIS...AND
EVENTUALLY INTO NORTHERN INDIANA/SOUTHERN LOWER MICHIGAN AS LARGER
SCALE FRONTAL RESPONSE SHIFTS INTO THE AREA. RAP INITIALIZATION DATA
DOES INDICATE THE RELATIVE STABLE BUBBLE ACROSS NORTHERN INDIANA
GIVING WAY TO AXIS OF 100 HPA MLCAPES ON THE ORDER OF 1000 J/KG LATE
THIS AFTERNOON.
BASED ON HOW CURRENT SCENARIO SEEMS TO BE UNFOLDING...HAVE NOT MADE
MANY CHANGES TO SCT POPS TRANSITIONING TO LIKELY POPS EARLY THIS
EVENING ESPECIALLY SOUTHERN HALF AS FRONTAL CIRCULATION BEGINS TO
MATURE. EXPECTING SCATTERED CONVECTION TO GENERALLY MERGE INTO
LARGER AREA OF RAIN AND EMBEDDED THUNDERSTORMS AS THIS OCCURS. SOME
DECENT RAINFALL AMOUNTS POSSIBLE ESPECIALLY SOUTHERN HALF GIVEN
MOISTURE POOLING ALONG THE FRONT AND INCREASING FRONTOGENETIC
RESPONSE LATER THIS EVENING. A FEW STRONGER CELLS ARE POSSIBLE LATE
AFTERNOON/EARLY EVENING THROUGH ABOUT 00Z ACROSS ESPECIALLY WESTERN
HALF GIVEN FAIRLY ROBUST DEEP LAYER SHEAR...BUT OVERALL SEVERE
THREAT SHOULD REMAIN ISOLATED DUE TO MARGINAL INSTABILITY PROFILES.
GENERALLY UTILIZED SREF IDEA FOR TIMING FRONTAL PROGRESSION INTO
SATURDAY MORNING WHICH LARGELY SUPPORTS GOING FORECAST SO NO
SIGNIFICANT CHANGES MADE TO SATURDAY POPS WITH BULK OF PRECIP
SHIFTING SOUTH OF THE AREA LATE MORNING.
&&
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 351 PM EDT FRI AUG 2 2013
BRIEF RETURN TO TRANQUIL WEATHER EXPECTED FOR EARLY NEXT WEEK.
SHORTWAVE RIDGING/SUBTLE MIDLEVEL HEIGHT RISES AND ANTICYCLONIC LOW
LEVEL FLOW WILL BRING DRY CONDITIONS BEGINNING SATURDAY NIGHT AS THE
COLD FRONT EXITS OUR AREA. LIGHT NORTHERLY WINDS/CAA AND DECREASING
CLOUDS SHOULD ALLOW FOR A COOL NIGHT WITH LOWS DROPPING INTO THE LOW
TO MID 50S PER CONSENSUS OF LATEST RAW AND STATISTICAL GUIDANCE.
STRONG NEGATIVE THETA-E ADVECTION WILL LEAD TO MOSTLY SUNNY SKIES ON
SUNDAY WITH JUST ENOUGH BOUNDARY LAYER MOISTURE SEEN IN FORECAST
SOUNDINGS TO SUPPORT A FEW DIURNAL CU. 850MB TEMPS ALSO DROP INTO
THE SINGLE DIGITS BUT AMPLE SUN SHOULD PUSH AFTERNOON TEMPS INTO THE
MID 70S FOR MOST LOCATIONS. SURFACE HIGH WILL DRIFT OVERHEAD BY
SUNDAY NIGHT WITH ANOTHER COOL NIGHT IN THE LOW 50S EXPECTED. A FEW
AREAS IN OUR NORTHEAST MAY EVEN TOUCH UPPER 40S IF MIDLEVEL CLOUDS
HOLD OFF LONG ENOUGH. SLIGHT MODERATION OF CANADIAN AIRMASS WILL
ALLOW TEMPS ON MONDAY TO CLIMB A DEGREE OR TWO HIGHER BUT STILL ONLY
MID TO UPPER 70S AT BEST.
BY THE MIDDLE OF NEXT WEEK A PIECE OF ENERGY IS EXPECTED TO BREAK
OFF THE POLAR VORTEX AND PHASE WITH THE PERSISTENT HUDSON BAY CLOSED
LOW...ESTABLISHING A DEEP PV ANOMALY THAT IS EXPECTED TO MEANDER
ACROSS SOUTHERN CANADA FOR MUCH OF NEXT WEEK. MEANWHILE...SEVERAL
WEAK SHORTWAVES EMANATING FROM THE NORTHWEST CONUS TROUGH WILL BE
SHEARED ACROSS THE GREAT LAKES IN FAST WNW FLOW ALOFT ON THE SOUTH
SIDE OF AFOREMENTIONED ANOMALY. RETURN FLOW ON THE BACKSIDE OF
DEPARTING SURFACE HIGH WILL ALSO BEGIN TO ADVECT A SLIGHTLY WARMER
AND MORE MOIST/UNSTABLE AIRMASS BACK INTO THE REGION DURING THIS
TIME. NEEDLESS TO SAY NUMERICAL GUIDANCE IS STRUGGLING WITH THE
EVOLUTION OF THIS PATTERN. LATEST 12Z GFS IS CONTINUING TO TREND
TOWARD THE MORE CONSISTENT ECMWF IN SHOWING THE BEST PRECIP
POTENTIAL HOLDING OFF UNTIL LATE TUESDAY AND INTO WEDNESDAY BUT
CONTINUES TO SHOW SIGNIFICANT DIFFERENCES BY LATE IN THE WEEK.
CERTAINLY COULD BE A FEW SCATTERED SHOWERS FROM WAA/ISENTROPIC
ASCENT ON TUESDAY BUT WILL HIGHLIGHT WEDNESDAY WITH THE HIGHEST POPS
AS THE MAIN SHORTWAVE/COLD FRONT PUSH THROUGH THE REGION. WILL LEAVE
THE END OF THE WEEK DRY FOR NOW UNTIL THE MODELS GET A BETTER HANDLE
ON EVOLUTION OF DEEP CANADIAN VORTEX. SLIGHTLY WARMER TEMPS EXPECTED
NEXT WEEK IN SOUTHWEST FLOW AHEAD OF FRONT BUT STILL HOVERING NEAR
TO EVEN SLIGHTLY BELOW NORMAL FOR EARLY AUGUST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 153 PM EDT FRI AUG 2 2013
ISENTROPIC FORCING WILL CONTINUE TO SHIFT EAST OF THE AREA AND
WEAKEN OVER THE NEXT FEW HOURS. THIS WILL RESULT IN LINGERING
SHOWERS AND ISOLATED THUNDERSTORMS ACROSS FAR NORTHEAST INDIANA TO
SHIFT EAST OF KFWA BY 19Z. VISIBLE SATELLITE IMAGERY DEPICTS SOME
ENHANCEMENT TO CU BACK ACROSS NORTHERN ILLINOIS ALONG WEAK
PREFRONTAL CONVERGENCE ZONE. LARGE SCALE FORCING WILL CONTINUE TO
INCREASE OVER THE NEXT SEVERAL HOURS AS UPPER LEVEL SHORT WAVE
ACROSS THE UPPER MIDWEST DROPS INTO THE GREAT LAKES REGION. WARM
SECTOR SHOULD BECOME INCREASINGLY MORE ACTIVE WITH SHOWERS AND
EMBEDDED THUNDERSTORMS BY THE 21Z-00Z TIMEFRAME. BASED ON
ORIENTATION OF PREFRONTAL CONVERGENCE ZONE...WOULD SUSPECT BEST
CHANCE OF SHRA/TSRA AT KFWA IN THE 00Z-05Z TIMEFRAME. CONFIDENCE IN
COVERAGE/DURATION OF ADDITIONAL SHOWERS AT KSBN SOMEWHAT LOW AND
HAVE CONFINED PRECIP MENTION TO TEMPO -SHRA IN THE 21Z TO 01Z
TIMEFRAME. WINDS TO BECOME LIGHT WEST/NORTHWEST BEHIND THE FRONT
TONIGHT WITH FOCUS FOR ADDITIONAL PRECIP LIKELY REMAINING SOUTH OF
KFWA ON SATURDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...AGD
AVIATION...MARSILI
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1137 PM CDT THU AUG 1 2013
.UPDATE...
ISSUED AT 947 PM CDT THU AUG 1 2013
AREA RADARS CONTINUE TO SHOW SCATTERED SHOWERS AND A FEW
THUNDERSTORMS OVER NE IA...INTO SW WI AND NW IL...MOVING SOUTHEAST
AND GENERALLY IN DISSIPATION MODE. A LARGE COMPLEX OF
THUNDERSTORMS IS CONCENTRATED OVER THE STATE OF NEB TONIGHT WHERE
00Z UPPER AIR ANALYSIS SHOWED FEED OF 14 PLUS C DEWPOINTS AT 850
MB INTERACTING WITH A SHORTWAVE IN THE NW FLOW ALOFT. THIS MCS IS
MOVING SOUTHEAST DOWN THE BACK SIDE OF THE UPPER RIDGE TOWARD KS
AND NW MO. LATEST HIGH RES MODELS CONTINUE TO SUGGEST THE
CONVECTION TO OUR N WILL HOLD TOGETHER AND MOVE THROUGH THE
FORECAST AREA OVERNIGHT...WHICH BASED ON THE PAST FEW
RUNS...APPEARS OVERLY AGGRESSIVE. WILL MORE LIKELY SEE THESE
SHOWERS AND THUNDERSTORMS MOVE INTO FAR EAST CENTRAL IA AND NW IL
AND CONTINUE DISSIPATE OVER THE NEXT COUPLE HOURS AS THE MUCAPE
VALUES CONTINUE TO WANE. BASED ON 00Z ANALYSIS AND A LOOK AT THE
NEW 00Z WRF...THERE APPEARS TO BE LITTLE SUPPORT FOR ADDITIONAL
THUNDERSTORMS OVER THE NEXT FEW HOURS...UNTIL THE SUPPORT OVER NEB
AND WEAK 850 MOISTURE CONVERGENCE REFOCUSES ON S CENTRAL IA AND
THEN SE IA TOWARD MORNING. NEITHER THIS MODEL...OR THE BULK OF
THE OPERATIONAL MODELS FROM THE PREVIOUS RUN HAD A GOOD HANDLE ON
THE PLACEMENT OF CONVECTION IN THE PLAINS THIS EVENING.
HAVE THUS MADE SIGNIFICANT REVISIONS TO THE FORECAST TO LOWER POPS
OVER ESPECIALLY THE NORTH FOR OVERNIGHT INTO FRIDAY MORNING.
&&
.SYNOPSIS...
ISSUED AT 326 PM CDT THU AUG 1 2013
12Z UA ANALYSIS HAS A WEAK 850MB COLD FRONT FROM LAKE HURON TO THE
MN/IA BORDER. A RESPECTABLE SHORTWAVE RAN FROM THE DAKOTAS INTO
WESTERN NEBRASKA WHILE A MOISTURE GRADIENT RAN FROM WESTERN MISSOURI
INTO NEBRASKA. SATELLITE/RADAR TRENDS THROUGH MID AFTERNOON SHOW
CONVECTION ASSOCIATED WITH THE DAKOTAS SHORT WAVE AND NEW CONVECTION
ON THE NORTH EDGE OF THE MOISTURE GRADIENT ACROSS NEBRASKA.
18Z SFC ANALYSIS HAS WEAK LOWS IN COLORADO AND SOUTHEAST WYOMING AND
ANOTHER IN WESTERN MINNESOTA. WEAK BOUNDARIES CONNECTED THE
MINNESOTA LOW TO THE LOW IN WYOMING WHILE SEVERAL WEAK TROFS WERE
ACROSS THE GREAT LAKES. A SFC MOISTURE BOUNDARY RAN FROM NEBRASKA
INTO NORTHWEST MISSOURI. DEW POINTS WERE IN THE 50S ACROSS THE GREAT
LAKES AND UPPER MIDWEST WITH 60S ACROSS MUCH OF THE PLAINS AND OHIO
VALLEY. DEW POINTS IN THE 70S WERE ACROSS THE SOUTHERN PLAINS AND
DEEP SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
DEEP MIXING THIS AFTERNOON HAS DROPPED THE DEW POINTS INTO THE LOW
TO MID 50S ACROSS WISCONSIN...NORTHERN ILLINOIS...AND NORTHEAST
IOWA. THE DEEP MIXING COMBINED WITH SUBSIDENCE HAS PREVENTED ANY
DIURNAL CLOUD DEVELOPMENT.
BASED ON SATELLITE AND RAP TRENDS USING THE MCS/LIFT TOOLS...THE
AGITATED CU DEVELOPMENT ALONG THE MN/IA BORDER SHOULD SLOWLY EVOLVE
INTO ISOLATED TO SCATTERED SHOWERS AND POSSIBLY A COUPLE OF
THUNDERSTORMS ACROSS THE NORTHERN CWFA DURING THE EVENING HOURS. THE
MORE SUBSTANTIAL STORM DEVELOPMENT ACROSS NEBRASKA MAY INDUCE SOME
ISOLATED SHOWERS OR A THUNDERSTORM ACROSS THE SOUTHERN HALF OF THE
CWFA BY MID TO LATE EVENING. STARTING AROUND MIDNIGHT THERE MAY BE A
LULL IN ACTIVITY FOR SEVERAL HOURS.
THE MCS TOOL IS REASONABLY CONSISTENT INDICATING A RESPECTABLE MCS
WILL DEVELOP THIS EVENING ACROSS EASTERN NEBRASKA/WESTERN IOWA AND
MOVE EAST SOUTHEAST OVERNIGHT ARRIVING IN THE SOUTHERN TWO THIRDS OF
THE CWFA PRIOR TO SUNRISE. CORFIDI VECTORS DO NOT SUGGEST ANY BACK
BUILDING BUT THE BACKWARD PROPAGATING VECTORS DO BECOME
PERPENDICULAR ACROSS THE SOUTHERN HALF OF THE CWFA SUGGESTING A WEAK
THREAT OF STORMS MOVING OVER THE SAME AREA.
THE DRIER AIR ACROSS THE AREA MAY RESULT IN SOME SMALL HAIL IN THE
STRONGER STORMS BEFORE THE ATMOSPHERE SATURATES LATE TONIGHT.
ON FRIDAY THE NOCTURNAL MCS WILL BE OVER THE CWFA DURING THE MORNING
HOURS AND WILL SLOWLY DECAY INTO MORE SHOWERS THAN THUNDERSTORMS BY
LATE MORNING. BOUNDARIES LEFT OVER FROM THIS MCS WILL THEN PROVIDE
THE FOCUS FOR NEW DEVELOPMENT DURING THE AFTERNOON. THE MCS TOOL
WHEN APPLIED TO SOME MODELS SUGGESTS THE POTENTIAL FOR ANOTHER MCS
AFFECTING THE AREA LATE FRIDAY AFTERNOON AND INTO FRIDAY NIGHT.
TEMPERATURES ON FRIDAY MAY REMAIN IN THE 60S FOR THE MORNING UNTIL
THE RAIN ENDS AND THEN CLIMBING INTO THE 70S DURING THE
AFTERNOON. ..08..
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 326 PM CDT THU AUG 1 2013
FORECAST FOCUS IS ON PERIODS FOR PRECIPITATION CHANCES AND BELOW
NORMAL TEMPERATURES THROUGH NEXT WEEK.
FRIDAY NIGHT AND SATURDAY...CHANCES FOR SHOWERS AND A FEW
THUNDERSTORMS CONTINUE FRIDAY EVENING AS UPPER SHORTWAVE ENERGY
WORKS ITS WAY ACROSS THE AREA. THE BETTER CHANCES LOOK TO BE ACROSS
THE SOUTHERN FORECAST SECTIONS...AND WILL DIMINISH SATURDAY MORNING
AS THE SHORTWAVE DEPARTS.
SUNDAY THROUGH THURSDAY...SEVERAL SHORTWAVES ARE FORECAST TO MOVE
THROUGH THE CONTINUED NORTHWEST FLOW AND BRING A COUPLE
OPPORTUNITIES FOR SHOWERS AND STORMS. AS CAN BE EXPECTED...FORECAST
MODELS ARE SHOWING QUITE A BIT OF VARIATION IN TIMING AND PLACEMENT
OF THESE SMALLER SCALE FEATURES. THEREFORE CONFIDENCE IN WHICH DAYS
HOLD THE BEST CHANCE FOR PRECIPITATION IS LOW. SEASONABLY COOL
TEMPERATURES WILL CONTINUE WITH HIGHS IN THE MIDDLE 70S TO LOWER 80S
RANGE...AND LOWS IN THE MIDDLE 50S TO LOWER 60S FOR MOST OF THE WEEK.
STOFLET
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1137 PM CDT THU AUG 1 2013
POTENTIAL FOR OVERNIGHT SHOWERS AND THUNDERSTORMS HAS GREATLY
DIMINISHED AND THIS IS REFLECTED IN THE LATEST FORECASTS. AN UPPER
LEVEL DISTURBANCE MOVING OUT OF THE PLAINS IS STILL EXPECTED TO
PRODUCE WIDESPREAD RAIN AND A FEW THUNDERSTORMS FRIDAY
MORNING...OVER ESPECIALLY SOUTHEAST IOWA INTO WEST CENTRAL
ILLINOIS. OVERNIGHT...POCKETS OF CLEARING SKIES MAY LEAD TO SOME
MVFR FOG WHICH IS INCLUDED AT CID AND DBQ. RAIN DEVELOPING FRIDAY
MORNING IS EXPECTED TO RESULT IN PERIODS OF VISIBILITIES IN A 5 TO
6 MILE RANGE. WILL CONTINUE TO FOCUS THE GREATEST POTENTIAL FOR
THUNDERSTORMS IN THE MID TO LATE AFTERNOON HOURS. RAIN AND
THUNDERSTORMS WILL END FROM NORTH TO SOUTH IN THE EVENING...
TRANSITIONING CONDITIONS TO PREVAILING VFR AT CID AND DBQ WHERE WEST
TO SOUTHWEST WINDS WILL BECOME LIGHT NORTHEAST.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...SHEETS
SYNOPSIS...08
SHORT TERM...08
LONG TERM...STOFLET
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1131 AM CDT FRI AUG 2 2013
.MESOSCALE DISCUSSION...
ISSUED AT 1133 AM CDT FRI AUG 2 2013
PERSISTENT MID-LEVEL WARM ADVECTION ZONE ACROSS SOUTH CENTRAL
KANSAS IN THE WAKE OF THE DEPARTING AND WEAKENING MESOSCALE
CONVECTION ACROSS SOUTHEAST KANSAS WILL BE FOCUS FOR RENEWED
SHOWERS AND STORMS INTO THE AFTERNOON. THE 12Z GFS AND TO A
LESSER EXTENT LATEST RUC SEEM TO HAVE DECENT HANDLE ON THIS
SCENARIO. THIS IN COMBO WITH MORE CLOUD COVER WILL HAMPER
MAX TEMPS AS WELL...SO HAVE UPDATED AND TWEAKED THEM DOWN
FOR AREAS GENERALLY EAST OF I-135. ADDITIONAL SURFACE BASED
CONVECTION MAY DEVELOP TOWARD PEAK HEATING FURTHER NORTH ACROSS
NORTH CENTRAL KANSAS AND TO OUR SOUTHWEST ALONG REMNANT MESO
OUTFLOW ACROSS SOUTHWEST KANSAS INTO NORTHWEST OKLAHOMA. THE
OVERALL CONFIDENCE ON AREAL COVERAGE AND PLACEMENT OF SAID
CONVECTION INTO THE EVENING IS RELATIVELY LOW...BASED ON HOW
THINGS EVOLVE DURING THE AFTERNOON. WHILE STRONG TO LOCALLY
SEVERE STORMS WILL BE POSSIBLE...THE MAIN RISK WILL CONTINUE
TO BE HEAVY RAINFALL AND THE FLOOD THREAT.
KED
&&
.SHORT TERM...(TODAY THROUGH SUNDAY MORNING)
ISSUED AT 329 AM CDT FRI AUG 2 2013
TODAY-TONIGHT: CURRENT CONVECTIVE COMPLEX OVER NE KS IS SLOWLY
PROPAGATING S-SE...AND EXPECT IT TO DROP SOUTH OVER SOUTHEAST KS
FOR THE MORNING HOURS. MOISTURE TRANSPORT LOOKS TO CONTINUE TO
POINT EAST INTO SE KS FOR THE MORNING HOURS..POSSIBLY LEADING TO
BACKBUILDING STORMS ACROSS THE FLINT HILLS AND SOUTHEAST KS FOR
THE MORNING HOURS. THIS COULD LEAD TO A MORNING FLASH FLOODING
THREAT FOR THIS AREA...SO HAVE DECIDED TO ISSUE A FLOOD WATCH FOR
THIS THREAT...WITH THE STORMS FINALLY WANING BY THE EARLY
AFTERNOON.
EXPECTING SOME KIND OF MESO INDUCED OUTFLOW BOUNDARY/DIFFERENTIAL
HEATING BAROCLINIC ZONE TO BE DRAPED OVER PORTIONS OF CEN KS TO
ALONG THE KS TURNPIKE FOR THE AFTERNOON/EVENING HOURS. THINK THE
ELEVATED MIXED LAYER WILL KEEP THINGS CAPPED OFF INITIALLY FOR
RENEWED CONVECTION ACROSS CEN KS...BUT CAP WEAKENS ENOUGH FOR STORMS
TO DEVELOP OVER CEN KS FOR THE EVENING HOURS. EXPECTING A VERY
UNSTABLE AIRMASS (SBCAPE 4500-4800 J/KG) TO BE LOCATED ALONG OR
JUST SOUTH OF THIS BOUNDARY...WITH INVERTED-V SOUNDINGS SUGGESTING A
DAMAGING WIND THREAT...WITH DEEP LAYER SHEAR EXPECTED TO BE AROUND
35-40 KTS. THINK THE STORMS WILL INITIALLY START OUT AS HP
SUPERCELLS SOMEWHERE ALONG INTERSTATE 70 OR POSSIBLY NEAR KRSL WHERE
A PSEUDO TRIPLE POINT WILL BE LOCATED AS THE SFC LOW PRESSURE AREA
IN SW KS INCHES FURTHER EAST INTO CEN KS.
850-700H MOISTURE TRANSPORT WILL FEED INTO THE INITIAL CONVECTION...
WITH THE STORMS CONGEALING INTO SOME FORM OF SOUTH-SE MOVING
MESOSCALE CONVECTIVE COMPLEX LATE THIS EVE OR TONIGHT. MOISTURE
TRANSPORT LOOKS TO SHIFT INTO SE KS BY SAT MORNING...WHICH COULD
LEAD TO SOME BACKBUILDING OF THE CONVECTION OVER SE KS INTO SAT
MORNING. WILL HAVE TO KEEP AN EYE ON THIS...GIVEN RECENT RAINFALL
AND POSSIBLE THREAT FOR FLOODING RAINFALL. STORMS WILL CERTAINLY BE
EFFICIENT RAINFALL PRODUCERS...GIVEN PRECIP WATER VALUES OF 150-200
PERCENT OF NORMAL. SO CERTAINLY COULD SEE ONE TO TWO INCH RAINFALL
AMOUNTS...ESPECIALLY OVER SE KS BY SAT MORNING. WITH THIS IN
MIND...HAVE DECIDED TO HEIGHTEN THE AWARENESS ONCE AGAIN BY
EXPANDING THIS MORNINGS FLOOD WATCH TO INCLUDE CEN KS AND SE KS
BEGINNING TNGT THROUGH SAT.
THE MORNING MCS WILL PLAY HAVOC WITH TEMPS FOR ERN SECTIONS
TODAY...WITH WIDESPREAD CLOUD COVER AND POSSIBLE MORNING SHOWERS.
THIS COULD LEAD TO COOLER TEMPS ACROSS SERN KS...WITH WARMER TEMPS
EXPECTED ACROSS CEN/S CEN KS SOUTH OF THE OUTFLOW BOUNDARY.
SAT-SUN MORNING: AS MENTIONED ABOVE...EXPECT SOME REMNANT MCS
ACTIVITY OVER SOUTHEAST KS FOR SAT MORNING. BUT FOCUS THAN SHIFTS
TO SAT AFTN/NIGHT...AS BOTH THE GFS AND NAM/WRF SHOW THE MAIN
SYNOPTIC COLD FRONT DROPPING SOUTH ACROSS THE FORECAST AREA FOR
SAT AFTERNOON. THIS WILL BE THE FOCUS FOR ANOTHER ROUND OF
SHOWERS/STORMS AND HEAVY RAINFALL ACROSS CEN AND SOUTH CEN KS FOR
SAT AFTN/NIGHT. LOTS OF CONCERN ABOUT FLOODING THREAT OVERNIGHT
SAT INTO EARLY SUN AS 850-700H MOISTURE TRANSPORT AND 850H FN-
CONVERGENCE WILL BE FOCUSED ACROSS SRN KS ALL NIGHT SAT NIGHT.
STORMS COULD TRAIN ALONG OR JUST NORTH OF THIS BOUNDARY ACROSS
MOST OF SOUTH CEN KS. SO WILL KEEP THE FLOOD WATCH GOING FOR MOST
OF THE AREA FOR SAT INTO SUN AS WELL. THIS PERIOD WILL HAVE TO BE
WATCHED...AS THIS EXTENDED FLOOD THREAT MAY LEAD TO SERIOUS
CONCERNS FOR LOCAL RIVERS/STREAMS ALREADY SWOLLEN BY RECENT RAINS.
KETCHAM
.LONG TERM...(SUNDAY AFTERNOON THROUGH THURSDAY)
ISSUED AT 329 AM CDT FRI AUG 2 2013
COULD SEE PORTIONS OF SRN KS DRY OUT SOME FOR THE REST OF THE DAY ON
SUN THRU TUE...AS WARM ADVECTION/MOISTURE TRANSPORT LOOKS TO SHIFT
BACK TO THE NORTH INTO NEB. NOT COMPLETELY SURE THAT AN MCS OR TWO
MIGHT DROP SOUTH INTO THE FORECAST AREA FOR MON OR TUE NIGHT...BUT
WITH UNCERTAINTY WILL NOT EXTEND THE FLOOD WATCH INTO THE BEGINNING
OF THE WEEK JUST YET. STAY TUNED.
KETCHAM
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 641 AM CDT FRI AUG 2 2013
NUMEROUS SHOWERS/THUNDERSTORMS WILL CONTINUE TO TRACK SOUTHEAST
ACROSS THE REGION THIS MORNING. WINDS WILL GRADUALLY VEER OUT FROM
THE NORTHEAST BACK AROUND TO THE SOUTHEAST FOR LATE THIS MORNING
AND AFTERNOON. MORE THUNDERSTORMS ARE EXPECTED TO REDEVELOP LATE
THIS AFTERNOON AND TONIGHT ACROSS THE EASTERN HALF OF KANSAS.
JAKUB
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 91 74 91 71 / 30 40 20 50
HUTCHINSON 91 71 89 70 / 20 40 30 60
NEWTON 88 72 89 70 / 30 40 30 60
ELDORADO 88 72 89 71 / 30 40 20 60
WINFIELD-KWLD 92 75 93 72 / 40 40 20 40
RUSSELL 96 71 88 69 / 20 30 30 60
GREAT BEND 95 70 89 69 / 20 20 30 60
SALINA 91 71 88 69 / 30 40 30 60
MCPHERSON 89 71 89 69 / 20 40 30 60
COFFEYVILLE 90 76 94 72 / 90 60 30 40
CHANUTE 87 74 89 71 / 40 70 30 50
IOLA 86 73 89 70 / 40 70 30 60
PARSONS-KPPF 88 75 91 71 / 60 60 30 50
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY AFTERNOON FOR KSZ052-053-069>072-
093>096-098>100.
FLOOD WATCH FROM 7 PM CDT THIS EVENING THROUGH SUNDAY AFTERNOON
FOR KSZ032-033-047>051-067-068-083-092.
&&
$$
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1132 PM CDT Thu Aug 1 2013
.UPDATE...
ISSUED AT 917 PM CDT THU AUG 1 2013
Convection continues to progress south southeast similar to what
the backward propagating Corfidi vectors would forecast...and
latest LAPS analysis shows the axis of low level moisture
convergence over northern KS. The HRRR has shown good consistency
with bringing the MCS into the area overnight...and with the RAP
and NAM continuing to show the advection of high theta-e air into
northeast KS with persistent isentropic upglide...hard to see what
would cause the MCS to fall apart before moving across the area. With
increasing confidence that the MCS will track across the
area...have increased pops and gone with categorical wording into
Friday morning.
UPDATE ISSUED AT 610 PM CDT THU AUG 1 2013
Convection across eastern NEB continues to propagate south
southeast as the backward propagating Corfidi vectors would
forecast. Think that as the low level jet veers to the southwest
and continues to advect moisture into northeast KS...that the
storms in NEB should hold together and move into the forecast
area. The HRRR appears to have a reasonable handle on this
convection and would expect it to move into northeastern KS
between 10 pm and midnight. RAP and NAM progs suggest that the
boundary layer will be stabilizing by then so there continues to
be some uncertainty in potential for severe storms. Steep mid
level lapse rates initially as the storms move south and deep
layer sheer around 40 kts would be supportive from some organized
storms. Although it still looks like some kind of MCS will
propagate across the area overnight tonight rather than discrete
storms making strong wind gusts more of a concern if the boundary
layer does not stabilize as forecast.
&&
.SHORT TERM...(THIS EVENING THROUGH Friday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Surface high pressure has slid off to the southeast this afternoon
with light southerly flow building into the area. The atmosphere
remains quite moist in the low levels with dewpoints in the middle
60s to lower 70s across the forecast area while temperatures have
risen into the upper 80s. These low level conditions have combined
with moderate lapse rates to produce a moderately unstable airmass
across central and eastern Kansas. Any cap appears to be quite weak
this afternoon but low level convergence and upper forcing are both
at a minimum, and most signs point to little to no convection
through the afternoon hours. However, a short wave trough moving
from South Dakota into Nebraska this afternoon has helped kick off a
few clusters of severe thunderstorms near the Nebraska border and
this activity is expected to move south and southeast this evening.
While the activity over Nebraska will initially be supercellular in
nature, expect it to eventually congeal cold pools and surge to the
south, likely with forward propagating segments and LEWP structures
and perhaps with embedded areas of mid level supercell rotation.
Instability will weaken a bit into the evening hours but should
still be sufficient when paired with large hodographs and strong
deep layer shear to pose a threat for severe weather as it moves
into eastern Kansas. The primary question at the current time is the
strength of the cap that will develop later in the evening. Most
model forecast soundings suggest that the cap does develop but if an
organized cold pool can lift parcels to 5 or 6 thousand feet, it
should be able to maintain surface based convection. Based on the
strength of the activity ongoing, would tend to believe that surface
based strong to severe convection could persist at least into
northern Kansas, and perhaps across the entire area as the MCS dives
south. The primary severe threat would seem to be damaging winds
although there is at least marginal potential for large hail
especially if some supercell characteristics can be maintained. The
tornado threat appears to be very very small. Will also have to
monitor potential for flooding in case the forward propagation of
the system stops and the low level jet kicks into existing
boundaries.
Expect remnant showers and convection to be ongoing Friday morning,
and any outflow boundaries will play a large role in thunderstorm
and severe weather potential for Friday afternoon. As of now, expect
a slightly better chance of outflow pushing all the way through the
forecast area, potentially keeping some of the area stable by
afternoon. However, if the sun comes out to quickly warm the post
outflow airmass, could see a fairly good severe weather setup by
afternoon. For now, there are too many uncertainties to get
specific, but the potential for storms certainly exists.
Barjenbruch
.LONG TERM...(Friday NIGHT THROUGH Thursday)
ISSUED AT 347 PM CDT THU AUG 1 2013
Friday night through Thursday...
Friday night as the LLJ increases moisture convergence develops
across NE KS which may be the focus for additional thunderstorm
development as the sfc front slowly progresses into the southern
portion of the CWA. The better chances for precip appear to be
across east central KS, although not confident if the lift will be
strong enough to get convection started. On Saturday during the day
the front continues to move south into OK as weak shortwave
disturbances slide eastward along the northern edge of the mid/upper
level high. This lift may cause an isolated shower or thunderstorm
across the southern CWA, but most areas will likely be dry. On
Saturday night a stronger shortwave is forecast to approach the area
from the central Rockies bringing the chances for rain therefore
pops increase during the overnight hours. The best chance for rain
will be Sunday as the deep layer moisture increases ahead of the
shortwave and warm air advection spreads eastward out of western KS.
High temperatures on Saturday will be in the mid to upper 80s and
slightly cooler on Sunday with cloud cover and rain chances.
Monday through Thursday...
The area remains under NW mid/upper level flow as the upper high
anchors over the southern Plains. Shortwaves embedded within the
flow are forecast to bring numerous rain chances to the area. Around
mid week a stronger mid/upper level low will dive southward into
southern Canada suppressing the ridge out west bringing more of a
zonal flow to the Central Plains. High temperatures will continue to
be below average with the chances of rain.
Sanders
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z Friday NIGHT)
ISSUED AT 1132 PM CDT THU AUG 1 2013
The convective system continues to move through south towards the
terminals...and has weakened suggesting the boundary layer has
stabilized somewhat. Think SHRA with embedded TS will persist
until the westward extend of the MCS dies or moves east. Models
show QPF hanging on well into Friday morning...but were also to
slow to bring the cold pool into KS. because of this will hedge to
precip ending sooner than models have. Conditions should be VFR
unless a heavier downpour moves through which could cause some
temporary MVFR VSBY and CIGS.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...WOLTERS
SHORT TERM...BARJENBRUCH
LONG TERM...SANDERS
AVIATION...WOLTERS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
203 PM CDT Fri Aug 2 2013
.SHORT TERM...(This Evening through Sunday night)
ISSUED AT 204 PM CDT FRI AUG 2 2013
A mid level wave was seen on satellite and via radar moving across
west Missouri. Convection has formed with this wave and was moving
east. Question is, how far east will it travel over the next
several hours, as it encounters drier air across the region. Will
gradually increase pops through the night. None of the models seem
to have a good handle on convective trends. The latest RAP model
is probably closest. Given low confidence in the latest solutions,
will not stray too far from persistence.
Even after a morning chance of convection, the probability for
more development will persist as a frontal boundary sags south
through the area late. Then, will decrease PoPs from north to
south Saturday night and focus them over the west and south into
Sunday and Sunday night.
Temperatures will be a combination of the latest MAV/MET MOS and
a blend of raw model output.
.LONG TERM...(Monday through Friday)
ISSUED AT 204 PM CDT FRI AUG 2 2013
For the beginning of the extended forecast period, namely Monday and
Tuesday, there has been a little less confidence on the eastward
extent of measurable PoP`s. During the last three days, attempted to
highlight the southwestern part of the WFO PAH county warning area,
namely southeast Missouri for rain chances. The low level surface
winds/moisture convergence appears pinned to southeast Missouri
through at least 12z (7am CDT) Tuesday. Although the SREF, GFS, and
ECMWF model precipitation parametrization schemes vary, the low
level frontal zones are similar during the aforementioned time
period. Given the lack if identifiable and consistent vorticity
advection above the frontal boundary, the decision was to limit the
precipitation chances close to the boundary, plus or minus 50 nm.
By late Tuesday night into Wednesday, the southern plains ridge
builds northward, shifting and sharpening the baroclinic zone and
frontal boundary further to the north. With this in mind, the higher
rain chances are shifted into southern Illinois, southwest Indiana,
and west Kentucky. This pattern remains intact through at least
Wednesday afternoon, when the upper ridge begins to flatten and
shift eastward across the lower Mississippi River valley. This
subtle pattern change, combined with a sharper meridional gradient
flow in the faster west to east flow, should lead to a much greater
tightening of the frontal boundary through the WFO PAH forecast area
next Thursday into Friday. Attempted to show a southward shift in
focus of higher PoP`s into toward the Arkansas and Tennessee borders
during this time period. It is also at this time that the highest
PoPs in the extended forecast period should be expected in the WFO
PAH forecast area.
Tuesday through next Friday will likely see max/min temperatures
approach or tie normals for this time of year, as the forecast area
is fully enveloped in the warm sector. With variable cloud cover,
heat index values should remain in check for most of next week. The
only exception may be next Wednesday afternoon, when heat index
values around 100 degrees may be possible along the southern border
counties of southeast Missouri.
&&
.AVIATION...
ISSUED AT 1158 AM CDT FRI AUG 2 2013
Will have ssw winds aob 10 kts rest of today with some cu and variable
high cloud cover. The high clouds will continue tonight. Late in the
night and through the morning hours Saturday, will carry prob30s for
light shra. Confidence in the coverage and evolution of convection
is quite variable in the model data. Confidence is very low. Thus the
conservative approach in the inclusion of any convection at all in
the TAFs.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...Noles
LONG TERM...Smith
AVIATION...Noles
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1141 PM CDT THU AUG 1 2013
.AVIATION...
VFR CONDITIONS EXPECTED NEXT 24-30 HOURS ALL TERMINALS. CONVECTION
EXPECTED TO BE MUCH LESS IN COVERAGE FRIDAY. 24/RR
&&
.SOUNDING DISCUSSION...
NO PROBLEMS WITH LAUNCH THIS EVENING. RATHER STEEP LAPSE RATE
SURFACE TO 850 MB...A MODEST ISOTHERMAL LAYER TO 810 MB THEN A
MOIST...POSSIBLY VIRGA MODIFIED LAPSE RATE TO 550 MB BEFORE
BECOMING PSEUDO TO TROPOPAUSE AT 145 MB. WINDS W-NW 5 KT SURFACE
TO 4500 FT...NNW-NNE 15-55 KT ABOVE...PEAK WIND 355/56KT AT
43.3KFT. P.W. 2.08 INCHES...HIGH CAPE OF 4319 J/KG AND STORM
MOTION 031/08KT. 24/RR
&&
.PREV DISCUSSION... /ISSUED 330 PM CDT THU AUG 1 2013/
SHORT TERM...
A SOMEWHAT ACTIVE AFTERNOON FOR PORTIONS OF THE FORECAST AREA
BRINGS HIGHER RAIN CHANCES. A COLD FRONT HAS BEEN SLOWLY TRACKING
RIGHT ACROSS MID MISSISSIPPI AND SHOULD BE APPROACHING LATER THIS
AFTERNOON. CONVECTION HAS BEGUN TO FIRE OFF AHEAD OF THE BOUNDARY
NORTH OF THE CWA. LOCAL WRF ALONG WITH HRRR IN FAIRLY GOOD AGREEMENT
DENOTING THAT CURRENT ACTIVITY WHICH IS TYPICAL OF THIS TIME OF
YEAR WILL INCREASE IN COVERAGE AS WELL AS INTENSITY AND MOVE ACROSS
THE CWA. PRECIP WATER VALUES ARE STILL QUITE HIGH AT OVER 2
INCHES...SO EXPECT VERY HEAVY RAIN WITH ANY STORMS THAT DO DEVELOP.
WIND SHEAR IS QUITE LIGHT AND WEST BULB TEMP WELL ABOVE 13K FEET
MEANS LITTLE THREAT OF HAIL OR TORNADOES. THUS THE MAIN THREAT WILL
BE GUSTY WINDS ON THE ORDER OF 35-45 MPH. SEVERE GUSTS NOT
IMPOSSIBLE BUT UNLIKELY. CONVECTION WILL LIKELY PERSIST THROUGH
SUNSET BUT NOT MUCH LONGER AFTER THAT. MAIN THREAT AREA APPEARS TO
BE EAST OF INTERSTATE 55 FROM MS ALL THE WAY TO SOUTH OF NEW
ORLEANS. HAVE BUMPED UP POPS SLIGHTLY FROM PREVIOUS FORECAST.
MEFFER
LONG TERM...
UPPER LEVEL TROUGH WILL LIFT NORTH AND RIDGE WILL BEGIN EXTENDING IN
OVER THE AREA FRIDAY THROUGH THE WEEKEND. WHILE A FEW STORMS MAY
DEVELOP...CONVECTION SHOULD BE QUITE LIMITED. EASTERN EDGE OF THE
UPPER LEVEL RIDGE WILL BEGIN WEAKENING LATE THIS WEEKEND THROUGH THE
MIDDLE OF NEXT WEEK. THIS WILL ALLOW FOR A FEW RAIN CHANCES TO
INCREASE ACROSS THE AREA. TEMPERATURES THROUGH THE ENTIRE PERIOD
WILL NOT CHANCE MUCH WITH HIGHS GENERALLY IN THE 90-95 DEGREE RANGE
WITH HEAT INDEX VALUES 100 TO 105. MID WEEK ONWARD THE RIDGE WILL
MOVE DIRECTLY OVER THE NORTHERN GULF COAST. ECMWF SUGGESTS A
SLIGHTLY STRONGER RIDGE WITH LOWER POPS AND HIGHER TEMPS WHILE GFS
IS MORE OF A WEAKER RIDGE WHICH WOULD ALLOW FOR MORE CONVECTION. SO
HAVE MADE LITTLE TO NO CHANGES TO THE EXTENDED FORECAST.
MEFFER
AVIATION...
GENERALLY VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH 00Z
SATURDAY AT THE TERMINAL LOCATIONS. THE POSSIBLE EXCEPTIONS WILL BE
ASSOCIATED WITH THE POTENTIAL FOR LIGHT FOG DEVELOPMENT TOWARD
DAYBREAK FRIDAY MORNING AT THE MORE FOG PRONE TAF SITES. THE
TERMINALS IN THE SOUTH HALF OF THE FORECAST AREA ARE THE ONES THAT
WILL HAVE THE BEST CHANCE OF SEEING ANY CONVECTION...NAMELY
KHUM...KNEW AND KMSY...BUT RAIN CHANCES WILL REMAIN SLIM.
18
MARINE...
A RIDGE OF HIGH PRESSURE WILL FLUCTUATE BETWEEN THE EASTERN AND
CENTRAL GULF THROUGHOUT THE FORECAST PERIOD. GENERALLY LIGHT SOUTH
TO WESTERLY AND AT TIMES VARIABLE WINDS AROUND 10 KNOTS OR LESS ARE
EXPECTED ALONG WITH WAVES HEIGHTS OF 2 FEET OR LESS.
MEFFER
DECISION SUPPORT...
DSS CODE...BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...NATURAL GAS WELL BLOWOUT SUPPORT.
SLURRY SUPPORT.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED
WATCH/WARNING/ADVISORY ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE TO HIGH RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 74 95 73 94 / 10 10 10 10
BTR 77 96 76 95 / 10 10 10 10
ASD 76 94 76 93 / 20 20 10 20
MSY 79 93 78 92 / 20 20 10 20
GPT 77 93 77 93 / 20 20 10 20
PQL 73 94 73 93 / 20 20 10 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...NONE.
MS...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CARIBOU ME
659 PM EDT FRI AUG 2 2013
.SYNOPSIS...
UNSETTLED CONDITIONS ARE EXPECTED THROUGH THE WEEKEND WHILE AN
UPPER TROUGH REMAINS ACROSS THE REGION. THE NEXT CHANCE OF DRY
WEATHER WILL BE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
700 PM UPDATE: ADJUSTED POPS/WX/SKY FOR LATEST RADAR AND SATELLITE
TRENDS...OTHERWISE FORECAST REMAINS ON TRACK.
AN OCCLUDED FRONT WILL CONTINUE TO PUSH ACROSS THE FORECAST AREA
LATE THIS AFTERNOON INTO THIS EVENING, ALONG WITH A LINE OF SHOWERS
AND THUNDERSTORMS. ONCE THIS ACTIVITY PUSHES INTO NEW BRUNSWICK,
EXPECT A MAINLY DRY NIGHT. SREF AND HRRR BOTH INDICATE FOG WILL
DEVELOP ACROSS DOWNEAST MAINE THIS EVENING AND REMAIN THROUGH THE
NIGHT. LOWS WILL GENERALLY BE IN THE MID AND UPPER 50S AREAWIDE.
FOR TOMORROW...A SHORTWAVE WILL TRAVERSE THROUGH THE FLOW ALOFT,
ALLOWING ANOTHER ROUND OF SHOWERS TO DEVELOP BY MID MORNING.
INSTABILITY, BOTH SURFACE-BASED AND ELEVATED, WILL BE FAIRLY
LIMITED, BUT WITH STEEPENING LAPSE RATES CAN`T COMPLETELY RULE OUT
AN ISOLATED THUNDERSTORM OR TWO. HIGHS WILL RANGE FROM AROUND 70
NORTH TO THE MID 70S SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SHOWERS WILL WIND DOWN SATURDAY NIGHT AS THE UPPER SHORTWAVE MOVES
ON TO THE EAST AND DAYTIME HEATING IS LOST. THEN ANOTHER, STRONGER
UPPER TROUGH WILL PASS OVER THE REGION ON SUNDAY, LEADING TO MORE
SHOWERS AND THUNDERSTORMS. HIGHS WILL BE VERY SIMILAR TO THOSE ON
SATURDAY; AROUND 70 NORTH AND MID TO LOWER 70S DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
ANOTHER UPPER LEVEL DISTURBANCE WILL BE MAKING ITS WAY THROUGH
MAINE. A SURFACE LOW WILL BE SET UP JUST TO THE EAST OF THE
REGION. AS THIS DISTURBANCE CONTINUES TO SLIDE EAST IT WILL KEEP
CHANCES OF SHOWERS FOR MUCH OF THE REGION. IT DOES LOOK LIKE MOST
GUIDANCE INDICATES THAT BEST CHANCES WILL BE ACROSS THE NORTH WITH
LESSER CHANCES TO THE SOUTH. RIGHT NOW NOT CONFIDENT IN ANY
THUNDERSTORM ACTIVITY ESPECIALLY SINCE MOST PORTIONS OF THE REGION
WILL STAY MOSTLY CLOUDY. THAT SAID WILL KEEP THUNDER OUT OF THE
FORECAST FOR NOW.
ANOTHER PIECE OF ENERGY WILL MOVE THOUGH THE LARGER UPPER LEVEL
LOW WITH SHOWERS TAPERING OFF MONDAY NIGHT. TUESDAY WILL HAVE A
BREAK AS SPOKE OF ENERGY MOVES EAST AND SLIGHT RIDGING ATTEMPTS TO
MOVE EAST. WHILE THERE IS STILL SOME DIVERGENCE IN THE TIMING OF
THE NEXT SYSTEM FOR MID WEEK. IT DOES LOOK LIKE THE GUIDANCE IS
MORE IN LINE WITH EACH OTHER THIS MORNING. RIGHT NOW THE 06Z GFS
IS BRINGING THE PRECIP INTO MOST OF THE REGION BY THURSDAY MORNING
WHILE THE 00Z ECMWF HOLDS BACK TIL THURSDAY AFTERNOON AND EVENING.
THE LATEST 12Z GFS IS SLOWER WITH EXITING THE PRECIP AND IS TRYING
TO COME IN TO CONSISTENCY WITH OTHER GUIDANCE. THE BOUNDARY DOES
LOOK TO EXIT THE REGION LATER ON FRIDAY BRINGING SOME IMPROVEMENT
TO THE REGION.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: KBHB WILL HOLD ON TO 200-400FT CIGS THROUGH THE NIGHT.
FOG IS ALSO EXPECTED. ELSEWHERE VFR-MVFR CONDITIONS EARLY THIS
EVENING WILL DETERIORATE TO GENERALLY IFR CONDITIONS DUE TO LOW
CLOUDS AT ALL TAF SITES BY LATE THIS EVENING AND OVERNIGHT.
SCATTERED SHOWERS AND THUNDERSTORMS WILL CONTINUE THIS EVENING,
ESPECIALLY AT KFVE, THE PRECIPITATION WILL WIND DOWN OVERNIGHT.
CEILINGS WILL LIFT TO VFR AFTER 14Z SATURDAY, BUT MORE SHOWERS AND
POSSIBLE THUNDERSTORMS WILL KEEP THE THREAT OF OCCASIONAL MVFR/IFR
CONDITIONS THROUGH SATURDAY.
SHORT TERM: MVFR WITH OCCASIONAL IFR WILL BE POSSIBLE RIGHT
THROUGH THE WEEKEND INTO EARLY NEXT WEEK AS AN UPPER TROUGH KEEPS
SHOWERS AND THUNDERSTORMS AROUND.
&&
.MARINE...
NEAR TERM: NO HEADLINES ARE ANTICIPATED THROUGH SATURDAY. THE
MAIN CONCERN WILL BE AREAS OF FOG, ESPECIALLY TONIGHT, WITH
VISIBILITY REDUCED TO BELOW 1SM.
SHORT TERM: NO HEADLINES WILL BE NEEDED THROUGH SUNDAY AS WINDS
AND WAVES WILL REMAIN BELOW ADVISORY CRITERIA.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...HASTINGS
LONG TERM...JORDAN
AVIATION...HASTINGS/HASTINGS
MARINE...HASTINGS/HASTINGS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
333 PM EDT FRI AUG 2 2013
.SYNOPSIS...
UNSETTLED CONDITIONS ARE EXPECTED THROUGH THE WEEKEND WHILE AN
UPPER TROUGH REMAINS ACROSS THE REGION. THE NEXT CHANCE OF DRY
WEATHER WILL BE EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AN OCCLUDED FRONT WILL CONTINUE TO PUSH ACROSS THE FORECAST AREA
LATE THIS AFTERNOON INTO THIS EVENING, ALONG WITH A LINE OF SHOWERS
AND THUNDERSTORMS. ONCE THIS ACTIVITY PUSHES INTO NEW BRUNSWICK,
EXPECT A MAINLY DRY NIGHT. SREF AND HRRR BOTH INDICATE FOG WILL
DEVELOP ACROSS DOWNEAST MAINE THIS EVENING AND REMAIN THROUGH THE
NIGHT. LOWS WILL GENERALLY BE IN THE MID AND UPPER 50S AREAWIDE.
FOR TOMORROW...A SHORTWAVE WILL TRAVERSE THROUGH THE FLOW ALOFT,
ALLOWING ANOTHER ROUND OF SHOWERS TO DEVELOP BY MID MORNING.
INSTABILITY, BOTH SURFACE-BASED AND ELEVATED, WILL BE FAIRLY
LIMITED, BUT WITH STEEPENING LAPSE RATES CAN`T COMPLETELY RULE OUT
AN ISOLATED THUNDERSTORM OR TWO. HIGHS WILL RANGE FROM AROUND 70
NORTH TO THE MID 70S SOUTH.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY/...
SHOWERS WILL WIND DOWN SATURDAY NIGHT AS THE UPPER SHORTWAVE MOVES
ON TO THE EAST AND DAYTIME HEATING IS LOST. THEN ANOTHER, STRONGER
UPPER TROUGH WILL PASS OVER THE REGION ON SUNDAY, LEADING TO MORE
SHOWERS AND THUNDERSTORMS. HIGHS WILL BE VERY SIMILAR TO THOSE ON
SATURDAY; AROUND 70 NORTH AND MID TO LOWER 70S DOWNEAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
ANOTHER UPPER LEVEL DISTURBANCE WILL BE MAKING ITS WAY THROUGH
MAINE. A SURFACE LOW WILL BE SET UP JUST TO THE EAST OF THE
REGION. AS THIS DISTURBANCE CONTINUES TO SLIDE EAST IT WILL KEEP
CHANCES OF SHOWERS FOR MUCH OF THE REGION. IT DOES LOOK LIKE MOST
GUIDANCE INDICATES THAT BEST CHANCES WILL BE ACROSS THE NORTH WITH
LESSER CHANCES TO THE SOUTH. RIGHT NOW NOT CONFIDENT IN ANY
THUNDERSTORM ACTIVITY ESPECIALLY SINCE MOST PORTIONS OF THE REGION
WILL STAY MOSTLY CLOUDY. THAT SAID WILL KEEP THUNDER OUT OF THE
FORECAST FOR NOW.
ANOTHER PIECE OF ENERGY WILL MOVE THOUGH THE LARGER UPPER LEVEL
LOW WITH SHOWERS TAPERING OFF MONDAY NIGHT. TUESDAY WILL HAVE A
BREAK AS SPOKE OF ENERGY MOVES EAST AND SLIGHT RIDGING ATTEMPTS TO
MOVE EAST. WHILE THERE IS STILL SOME DIVERGENCE IN THE TIMING OF
THE NEXT SYSTEM FOR MID WEEK. IT DOES LOOK LIKE THE GUIDANCE IS
MORE IN LINE WITH EACH OTHER THIS MORNING. RIGHT NOW THE 06Z GFS
IS BRINGING THE PRECIP INTO MOST OF THE REGION BY THURSDAY MORNING
WHILE THE 00Z ECMWF HOLDS BACK TIL THURSDAY AFTERNOON AND EVENING.
THE LATEST 12Z GFS IS SLOWER WITH EXITING THE PRECIP AND IS TRYING
TO COME IN TO CONSISTENCY WITH OTHER GUIDANCE. THE BOUNDARY DOES
LOOK TO EXIT THE REGION LATER ON FRIDAY BRINGING SOME IMPROVEMENT
TO THE REGION.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
NEAR TERM: IFR CONDITIONS DUE TO LOW CLOUDS WILL PREVAIL AT ALL
TAF SITES THIS EVENING AND OVERNIGHT, WITH CEILINGS OCCASIONALLY
LIFTING TO MVFR THIS EVENING. VLIFR POSSIBLE AT KBHB LATE TONIGHT
DUE TO FOG. SHOWERS AND THUNDERSTORMS ARE LIKELY THIS EVENING,
ESPECIALLY AT KBGR, THE PRECIPITATION WILL WIND DOWN OVERNIGHT.
CEILINGS WILL LIFT TO VFR AFTER 14Z SATURDAY, BUT MORE SHOWERS AND
POSSIBLE THUNDERSTORMS WILL KEEP THE THREAT OF OCCASIONAL MVFR/IFR
CONDITIONS THROUGH SATURDAY.
SHORT TERM: MVFR WITH OCCASIONAL IFR WILL BE POSSIBLE RIGHT
THROUGH THE WEEKEND INTO EARLY NEXT WEEK AS AN UPPER TROUGH KEEPS
SHOWERS AND THUNDERSTORMS AROUND.
&&
.MARINE...
NEAR TERM: NO HEADLINES ARE ANTICIPATED THROUGH SATURDAY. THE
MAIN CONCERN WILL BE AREAS OF FOG, ESPECIALLY TONIGHT, WITH
VISIBILITY REDUCED TO BELOW 1SM.
SHORT TERM: NO HEADLINES WILL BE NEEDED THROUGH SUNDAY AS WINDS
AND WAVES WILL REMAIN BELOW ADVISORY CRITERIA.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...HASTINGS
LONG TERM...JORDAN
AVIATION...HASTINGS/HASTINGS
MARINE...HASTINGS/HASTINGS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
936 PM EDT SAT AUG 3 2013
.SYNOPSIS...
A COLD FRONT ACROSS PENNSYLVANIA THIS EVENING WILL MOVE ACROSS
THE AREA OVERNIGHT. HIGH PRESSURE WILL RETURN SUNDAY AND REMAIN
OVER THE AREA THROUGH THE FIRST PART OF THE WEEK. A COLD FRONT
WILL APPROACH THE AREA LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
THE LAST OF THE SHOWERS AT 01Z WERE IN A BAND EXTENDING FROM THE
NORTHERN SHENANDOAH VALLEY...JUST SOUTH OF WINCHESTER...THROUGH
THE DC AREA AND EASTWARD TO ANNAPOLIS...ALL ASSOICATED WITH A WEAK
INSTABILITY LINE. NO LIGHTNING WAS OCCURING ACCORDING TO EITHER THE
NLDN AND DCLMA LIGHTNING NETWORKS WITH THIS BAND...ALTHOUGH IAD
DID REPORT AT LEAST ONE FLASH JUST BEFORE 0045Z. SO FAR...RAINFALL
AMOUNTS WITH THIS BAND HAVE BEEN ANYWHERE FROM ONE TO TWO TENTHS
OF AN INCH. THIS BAND OF SHOWERS SHOULD BE WELL SOUTH OF DC BY
MIDNIGHT...AND EXPECT SHOWER ACTIVITY TO DECREASE IN COVERAGE AND
INTENSITY AFTER MIDNIGHT ACROSS THE SOUTHERN HALF OF THE CWA.
THE SURFACE COLD FRONT WAS STILL BACK ACROSS CENTRAL PENNSYLVANIA
AND MAKING STEADY PROGRESS SOUTHWARD.THE HRRR 3KM EXPERIMENTAL
MESOSCALE MODEL HAD A DECENT HANDLE ON THE FRONT AS REPRESENTED BY
ITS FORECAST DEW POINT/WIND FIELD. UPPER 50S DEW POINTS WILL
GRADUALLY OVERSPREAD THE CWA AFTER 06Z FROM THE NORTH AND CONTINUE
SPREADING SOUTH OVERNIGHT...ALTHOUGH DEW PTS ACROSS THE SOUTHERN
THIRD TIER OF COUNTIES IN THE CWA WILL STILL BE IN LOWER 60S
AROUND SUNRISE SUNDAY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/...
VERY COMFORTABLE AND LOWER HUMIDITY AIR WILL FOLLOW THE FRONT AS
IT STREAMS IN ON SOMEWHAT BRISK NW WINDS. MOST MODELS ARE SHOWING
VERY DRY AIR SUNDAY AFTERNOON WITH DEWPOINTS IN THE LOWER 50S BY
EARLY AFTERNOON...AND WITH COLD ADVECTIONS MAX TEMPS ONLY NEAR 80.
PREVIOUS LONG TERM DISCUSSION FOLLOWS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE OVER THE CWA SUNDAY NIGHT MOVES OFF THE COAST
MONDAY/MONDAY NIGHT. RETURN FLOW WILL START TO BRING MOISTURE BACK
INTO THE AREA. BOTH NAM/GFS SHOW A SHORTWAVE IN MID-LEVEL
WESTERLY FLOW BRINGING THE CHANCE FOR SHOWERS LATE MONDAY NIGHT
INTO TUESDAY AND HAVE ADDED CHANCE POPS TO THE FORECAST.
MID-WEEK PERIOD MAY BE PERIODICALLY UNSETTLED AS THE REMNANTS OF
THE FRONTAL BOUNDARY RISE BACK TO THE NORTH. ATMOSPHERE SHOULD BE
BACK TO A MOIST/UNSTABLE ONE...SO CHANCE OF SHOWERS/THUNDERSTORMS
WILL BE IN THE FORECAST UNTIL THE NEXT FRONTAL PASSAGE. GFS SHOWS
THIS OCCURRING SOMETIME LATE IN THE WEEK AND ECMWF /00Z RUN/ IS
SIMILAR.
AFTER A BELOW NORMAL EARLY WEEK...TEMPERATURES ARE FORECAST TO
RETURN NEAR NORMAL DURING THE MID TO LATE WEEK PERIOD.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
IAD BRIEFLY HAD IFR CIGS AS THE HEAVIEST BATCH OF RAIN MOVED
THROUGH AFTER 00Z...BUT BAND OF SHOWERS HAS BEEN WEAKENING. EXPECT
VFR CONDTIONS OTHERWISE OVERNIGHT.
HIGH PRESSURE BUILDS IN BEHIND THE FRONT FOR SUNDAY...THEN MOVES
OFFSHORE EARLY NEXT WEEK. UPPER DISTURBANCE WILL BRING A CHANCE OF
SHOWERS AGAIN MONDAY NIGHT INTO TUESDAY.
&&
.MARINE...
WENT AHEAD AND RAISED A SMALL CRAFT ADVISORY FOR THE LOWER TWO MD
BAY ZONES ON SUNDAY...12Z-23Z AS MODELS SUGGEST PRESSURE GRADIENT
WILL BE SUFFICIENT TO SUPPORT MARGINAL SCA CRITERIA WIND GUSTS OF
18 KTS IN THE LOWER BAY. BEST TIME FOR PEAK WIND GUSTS IS FROM
ABOUT 13Z THROUGH 19Z. THE NORTHERN MD BAY COULD HAVE A FEW GUSTS
NEAR SMALL CRAFT LEVELS...BUT AT THIS POINT LEFT THEM OUT AS
CONFIDENCE WAS NOT HIGH THERE.
HIGH PRESSURE BUILDS IN LATER SUNDAY AND SUNDAY NIGHT BEFORE MOVING
OFF THE COAST FOR EARLY NEXT WEEK.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM TO 7 PM EDT SUNDAY FOR ANZ533-
534.
&&
$$
SYNOPSIS...SMZ
NEAR TERM...SMZ
SHORT TERM...SMZ
LONG TERM...BPP
AVIATION...SMZ
MARINE...SMZ
AREA FORECAST DISCUSSION
NWS GAYLORD MI
221 AM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 407 PM EDT THU AUG 1 2013
A SERIES OF WEAK DISTURBANCES WILL DRIFT INTO NORTHERN MICHIGAN
THROUGH FRIDAY...BRINGING LOW CHANCES OF SHOWERS AND POSSIBLY A
THUNDERSTORM. THE BEST CHANCE WILL BE IN NORTHEAST LOWER
MICHIGAN BUT MOST COMMUNITIES WILL SEE RATHER PLEASANT WEATHER.
HIGH PRESSURE WILL BUILD INTO THE WESTERN GREAT LAKES OVER THE
WEEKEND...RESULTING IN COOLER AND RAIN FREE WEATHER. THE NEXT
CHANCE FOR RAIN DOES NOT ARRIVE UNTIL NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 219 AM EDT FRI AUG 2 2013
SHOWERS ARE EXPANDING OUT AHEAD OF A SHORTWAVE IN THE ARROWHEAD OF
MN. LATEST HRRR/RUC BOTH SUPPORTING CONTINUED EXPANSION OF THE
SHOWERS AND EMBEDDED STORMS WITHIN COLD POL ALOFT AND STEEP MID
LEVEL LAPSE RATES. INCREASED CHANCES OF RAIN FOR THESE SHOWERS
ARRIVING TOWARD DAYBREAK IN EASTERN UPPER AND INTO THE REMAINDER
OF NRN MICHIGAN THIS MORNING.
UPDATE ISSUED AT 1012 PM EDT THU AUG 1 2013
A SOMEWHAT UNCERTAIN NIGHTTIME FORECAST. FIRST...A RENEGADE SHRA
IS STEADILY CROSSING LAKE MI...HEADING TOWARD THE COAST BETWEEN
FRANKFORT AND EMPIRE. IT ISN/T TERRIBLY HEALTHY LOOKING...BUT HAS
HELD TOGETHER BETTER THAN ANYTHING ELSE TO THIS POINT. VERY SHORT-
TERM GRIDS CONTINUE TO BE UPDATED TO ACCOUNT FOR A FEW SHRA LATE
THIS EVENING.
THE OVERNIGHT...IN THE BIG PICTURE...FEATURES LOWERING HEIGHTS AND
STEEPENING MID-LEVEL LAPSE RATES (TO 6.25-6.5C/KM 700-500MB). WV
IMAGERY SHOWS A SHORTWAVE MOVING ESE-WARD ACROSS NORTHERN MN...AS
MOST MODELS INDICATE. WAVE WILL REACH CENTRAL TO NORTHERN LOWER MI
TOWARD MORNING. CURRENTLY...MOST OF THE SHRA/TSRA ACTIVITY IS
ALONG THE NORTHERN FLANK OF THE WAVE...OVER FAR NORTHERN MN AND
ADJOINING PORTIONS OF CANADA. AT THE LOW LEVELS...WNW-ERLY FLOW WILL
PERSIST FROM 850MB ON DOWN...PERHAPS SOME VERY SHALLOW BACKING AT
950MB TOWARD 12Z. STILL...NOTHING RESEMBLING A CLASSIC LOW LEVEL JET.
SHORT-TERM HI-REZ MODELS ARE ALL OVER THE PLACE. THE NAM BRINGS
PRECIP INTO WESTERN SECTIONS BY DAWN...THE RUC DOES THE SAME TO
NORTHERN/EASTERN SECTIONS...THE WRF-NMM TO THE SOUTH...THE LOCAL
4KM WRF TO NOBODY.
GIVEN WHERE PRECIP IS NOW IN RELATION TO WHERE THE SHORTWAVE IS
PROGGED TO GO...FAVORS THE GOING FORECAST...WHICH HAS THE HIGHEST
POPS IN EASTERN UPPER INTO SOME SECTIONS OF FAR NE LOWER (RUC-
LIKE). THAT SAID...ALSO AGREE IN KEEPING AT LEAST A SLIGHT CHANCE
IN ALL AREAS AFTER 09Z.
MINOR CHANGES AT MOST TO CLOUD COVER AND MINS.
UPDATE ISSUED AT 703 PM EDT THU AUG 1 2013
DIURNAL CONVECTION OVER NORTHERN MI SEEMS TO HAVE JUST ABOUT RUN
ITS COURSE. INSTABILITY OVER FAR SE UPPER MI...AND IN THE SAGINAW
BAY REGION...HAS BEEN JUST ABOUT USED UP. SPC MESO PAGE INDICATING
LESS THAN 500J/KG ACROSS THE ENTIRE FORECAST AREA...WITH THE
HIGHEST POCKET IN NE LOWER S OF APN. INCOMING CONVECTIVE REMNANTS
HAVE MOVED INTO NW LOWER WITHOUT REGENERATION. SHOULD BE ABLE TO
GET AWAY WITH ISOLATED POPS FOR THE COUPLE OF HOURS OR SO...AND
NOTHING THEREAFTER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CENTERED OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WHILE A VERY PERSISTENT UPPER TROUGH
REMAINS OVER CENTRAL CANADA AND THE GREAT LAKES REGION. THIS PATTERN
WILL SWEEP A COUPLE BOUNDARIES OVER NRN MI...MAINLY FRIDAY. AN UPPER
LVL COLD POOL ASSOCIATED WITH THE 500MB TROUGH NEAR HUDSON BAY WILL
CONTINUE TO SINK INTO THE NORTHERN LAKES THROUGH FRIDAY...HELPING
KEEP TEMPS AT MID LEVELS AROUND 8C/9C WHILE 500MB TEMPS DROP TO
-18C. THIS VERTICAL TEMPERATURE PROFILE WILL STEEPEN MID LEVEL
LAPSE RATES TO NEARLY 6C/KM TONIGHT INTO FRIDAY EVENING. EXPECT
CONVECTION THIS AFTERNOON WILL DIMINISH THIS EVENING WITH LACK OF
SOLAR RADIATION AND PRESENCE OF ANY BOUNDARY...THOUGH BECOME MORE
WIDESPREAD FRIDAY AFTERNOON ONCE AGAIN IN ADVANCE OF APPROACHING
SURFACE AND UPPER LEVEL FEATURES. MODEL SOUNDINGS SHOWING THE BEST
CONVERGENCE ASSOCIATED WITH APPROACHING BOUNDARIES FRIDAY...TO
FINALLY EXIT EAST INTO LAKE HURON AFTER 18Z FRIDAY.
OVERALL WILL KEEP SMALL CHC`S OF SHOWERS AND THUNDERSTORMS ACROSS
THE CWA TONIGHT AND FRIDAY. WILL MENTION HIGH TEMPS FRIDAY SIMILAR
TO THURSDAY TEMP VALUES...IN THE LOWER 70S...AS UPPER TROUGH AND
850/500MB TEMPS REMAIN THE SAME.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
OVERVIEW: 4-WAVE LONGWAVE PATTERN IN PLACE ACROSS THE NORTHERN
HEMISPHERE TO START THIS FORECAST PERIOD...ONE LONG WAVE TROUGH AXIS
BISECTED THE MIDWEST (AROUND 90W) AND BOUNDED BY RIDGING ALONG EACH
COAST. THIS PATTERN IS FORECAST TO CHANGE VERY LITTLE THROUGH THE
EXTENDED FORECAST...ALTHOUGH WITH SLOW EASTWARD MIGRATION OF THE
LONGWAVE TROUGH INTO THE GREAT LAKES/NEW ENGLAND AND SHARP
RIDGING/VERY WARM TEMPS IN THE WEST. THIS KEEPS OVERALL COOL/BELOW
NORMAL TEMPS INTACT FOR THE REGION THROUGH NEXT WEEK.
WEATHER-WISE THROUGH SUNDAY...WE START OUT ON THE UNSETTLED SIDE OF
THINGS FOR THE END OF THE WORK WEEK AS A COUPLE SHORT WAVES DIP
THROUGH THE GREAT LAKES REGION. HOWEVER...DEVELOPING NW FLOW ALOFT
FRIDAY NIGHT AND HEADING INTO THE WEEKEND LEADS TO A LARGE EXPANSE
OF HIGH PRESSURE BUILDING ACROSS THE NRN PLAINS THROUGH THE GREAT
LAKES. THIS WILL SET THE STAGE FOR QUIET WEATHER FOR THIS UPCOMING
WEEKEND...ALBEIT CONTINUED COOL-ISH WITH DAYTIME TEMPS RUNNING
AROUND 10 DEGREES BELOW NORMAL.
MONDAY THROUGH THURSDAY...QUIET WEATHER TO START NEXT WORK WEEK WITH
HIGH PRESSURE/NORTHWEST FLOW ALOFT AND COOLER TEMPS STILL SETTLED
OVER THE REGION. THEN...TUESDAY THROUGH THURSDAY BECOMES A BIT MORE
NEBULOUS AS STRONGER SHORT WAVE AND ASSOCIATED CLOSED LOW DROP OUT
OF CENTRAL CANADA DOWN INTO THE MIDWEST/GREAT LAKES. MODEL
TIMING/RUN-TO-RUN DIFFERENCES REGARDING THE PATTERN EVOLUTION ADD TO
THE UNCERTAINTY AS THE ECMWF TURNS DOWNRIGHT COOL ONCE AGAIN BY LATE
NEXT WEEK WITH ANOTHER CLOSED LOW/POCKET OF COOL AIR DESCENDING OVER
THE GREAT LAKES (BY COMPARISON...GFS IS MORE PROGRESSIVE AND
WARMER). WILL HAVE CHANCY POPS AND BELOW NORMAL TEMPS THROUGH THE
TUESDAY-THURSDAY TIMEFRAME GIVEN THE PROXIMITY TO THE TIGHTER
BAROCLINIC ZONE... ALTHOUGH A FAIR AMOUNT OF UNCERTAINTY SURROUNDS
THIS TIMEFRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM EDT THU AUG 1 2013
MAINLY VFR...THOUGH PRECIP COULD PRODUCE BRIEF RESTRICTIONS VERY
LATE TONIGHT INTO FRIDAY. ALSO SOME EARLY AM FOG AT PLN.
LOW PRESSURE ON HUDSON BAY CONTINUES TO PUSH OCCASIONAL COLD
FRONTS ACROSS NORTHERN MI. THE NEXT WILL MOVE ACROSS THE AREA
FRIDAY AFTERNOON. SOME SHRA CONTINUE TO PERCOLATE OVER LAKE MI
AHEAD OF THIS SYSTEM. SOMEWHAT MORE WIDESPREAD SHRA WILL DEVELOP
ESE-WARD INTO EASTERN UPPER AND FAR NORTHERN LOWER...INCLUDING
PLN/APN. ANOTHER ROUND OF SHRA/PERHAPS TSRA WILL DEVELOP AHEAD OF
THE FRONT...MAINLY OVER N CENTRAL LOWER MI AND POINTS EAST
(AGAIN...APN/PLN HAVE THE BEST CHANCE OF BEING IMPACTED).
LIGHT WINDS TONIGHT...STARTING OUT FROM THE SW FRIDAY MORNING THEN
VEERING NW TO N IN THE AFTERNOON/EVENING (BECOMING NE OFF THE
LAKE AT APN).
&&
.MARINE...
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CURRENTLY OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WITH A COUPLE OF WEAK BOUNDARIES
SWEEPING OVER THE GREAT LAKES THROUGH FRIDAY. EXPECT WINDS AND
WAVES TO REMAIN BELOW SCA CRITERIA THRU THE PERIOD...WITH WESTERLY
WINDS TONIGHT TRENDING NORTHWEST BY FRIDAY. &&
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...SD
SYNOPSIS...NS
SHORT TERM...SR
LONG TERM...BA
AVIATION...JZ
MARINE...SR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
140 AM EDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 910 PM EDT THU AUG 1 2013
SHOWERS AND ISOLATED THUNDERSTORMS HAVE MOVED INTO WESTERN LAKE
SUPERIOR AHEAD OF THE UPPER SHORT WAVE OVER NW MN. THE SUSPICION IS
THAT MANY OF THESE ARE DIURNALLY DRIVEN AS THE INTENSITY OF THEM
OVER MN HAVE SEEMED TO DIMINISH OVER THE LAST HOUR OR TWO.
HOWEVER...THE COMBINATION OF THE UPPER DISTURBANCE MOVING OVER LAKE
SUPERIOR TONIGHT...AND MUCH OF THE AREA BEING UNDER THE LEFT EXIT
REGION OF THE UPPER JET WOULD SUGGEST AT SOME SCATTERED SHOWERS
MOVING ACROSS THE AREA OVERNIGHT...ESPECIALLY ACROSS LAKE SUPERIOR
AND THE KEWEENAW PENINSULA. AS SUCH...HAVE INTRODUCED SCATTERED
SHOWERS INTO THE FORECAST IN THOSE AREAS....AND ISOLATED SHOWERS
ACROSS THE REMAINDER OF THE AREA. THIS IS SIMILAR TO WHAT THE THE
LOCAL RAPID UPDATE WRF MODEL AND HRRR SUGGEST. WILL ALSO MAINTAIN A
SMALL CHANCE FOR THUNDER OVERNIGHT AS 850-500MB LAPSE RATES STEEPEN
TO NEARLY 7 C/KM AS THE UPPER WAVE MOVES OVERHEAD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
SMALL CHANCES OF SHOWERS WILL CONTINUE THROUGH FRIDAY AS THE REGION
REMAINS UNDER THE INFLUENCE OF MULTIPLE WEAK SHORTWAVES DIGGING
SOUTHEAST ON THE BACKSIDE OF A BROAD MID-LEVEL LOW OVER NORTHERN
ONTARIO.
TONIGHT...ONGOING SHOWERS ACROSS THE INTERIOR EAST HALF ON THE FIRST
SHORTWAVE WILL DIMINISH WITH THE LOSS OF DAYTIME HEATING THIS
EVENING. THE SECOND SHORTWAVE IN THE WEAK WAVE-TRAIN WILL PASS OVER
THE CWA OVERNIGHT...AND ONCE AGAIN BRING A SLIGHT CHANCE OF SHOWERS.
THIS WAVE IS CURRENTLY CROSSING LAKE WINNIPEG...AND IS EXPECTED TO
ARRIVE ACROSS THE WESTERN CWA AFTER MIDNIGHT. WATER VAPOR IMAGERY
GIVES THE SHORTWAVE A RATHER BENIGN LOOK AS CLOUD COVER HAS
DIMINISHED SIGNIFICANTLY OVER THE PAST DAY. IT APPEARS THAT THE WAVE
HAS BECOME SOMEWHAT SHEARED OUT OVER NORTHERN SASKATCHEWAN.
UPPER-LEVEL JET SUPPORT WILL BE MARGINAL...WITH UPPER MI SITUATED
BETWEEN THE LEFT-EXIT AND ENTRANCE REGIONS OF THE JET.
NONETHELESS...SHOWERS AND A FEW STORMS HAVE DEVELOPED OVER SOUTHWEST
ONTARIO THIS AFTERNOON AND HIGH-RES MODELS CONTINUE TO BRING SHOWERS
INTO THE WEST HALF IN THE EVENING. HAVE THEREFORE KEPT POPS IN THE
FORECAST...BUT LIMITED THEM TO LOW-END SLIGHT CHANCES FOLLOWING THE
WINDOW OF BEST FORCING FROM WEST TO EAST ACROSS THE CWA. HAVE ALSO
LEFT POPS HIGHER OVER THE EAST TOWARD 12Z FRIDAY AS THE INFLUENCE OF
THE INCOMING LAST SHORTWAVE...MENTIONED BELOW...PROVIDES SOME
ASSISTANCE TO THE DEPARTING WAVE.
FRIDAY...THE FINAL SHORTWAVE IS EXPECTED TO BE A BIT MORE POTENT
THAN THE PREVIOUS TWO...AND WILL BE TRACKING SOUTHEAST ACROSS THE
ARROWHEAD OF MN TO JUST WEST OF THUNDER BAY BY 12Z FRIDAY. MODEL
TRENDS HAVE BEEN FAIRLY CONSISTENT...THOUGH THE NAM HAS TRENDED
TOWARD A SLIGHT STRONGER TROUGH OVER THE PAST FEW RUNS. MOISTURE
AVAILABILITY WILL BE LOW...WITH LESS THAN 10 PERCENT RH THROUGH MUCH
OF THE LAYER ABOVE 700 MB ACROSS THE WEST HALF. THE BEST CHANCE OF
SEEING ANY PRECIP STILL LOOKS TO BE ACROSS THE INTERIOR EAST HALF IN
THE AFTERNOON AS HEATING AND LAKE BREEZE CONVERGENCE ASSIST WITH
LIFT FROM THE SHORTWAVE. MID-LEVEL MOISTURE WILL ALSO A BIT
HIGHER...THOUGH STILL RATHER DRY...ACROSS THE EAST HALF. SAW NO
REASON TO CHANGE THE GOING FORECAST OTHER THAN TO MAKE SOME TWEAKS
IN TIMING AND PLACEMENT IN THE MESOSCALE. THAT INCLUDED EXPANDING
POPS WESTWARD TO THE INTERIOR CENTRAL DURING PEAK HEATING GIVEN
TODAYS TRENDS OF A FEW LIGHT SHOWERS DEVELOPING ALBEIT POOR
MOISTURE. AS FOR THUNDER POTENTIAL...MLCAPE IS PROGGED TO BE A
MEAGER 500 J/KG WITH NORMALIZED CAPE LESS THAN 0.1. THIS WOULD GIVE
POTENTIAL FOR AT LEAST SOME ISOLATED LIGHTNING IN ANY OF THE
STRONGER SHOWERS.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 409 PM EDT THU AUG 1 2013
TROUGH OVER THE EASTERN HALF OF CANADA AND NE U.S./GREAT LAKES
REGION STAYS IN PLACE THROUGH MOST OF THE EXTENDED PERIOD OF THE
FCST DUE TO PERSISTENT REX BLOCK OVER NW CANADA AND THE PAC NW COAST
AND MEAN RDGG OVER THE NORTH ATLANTIC. AS A RESULT OF THIS PATTERN
...TEMPS SHOULD REMAIN AT OR BELOW NORMAL THROUGH THE PERIOD. A
SERIES OF NW FLOW SHORTWAVES ROTATING ON THE SRN/WRN PERIPHERY OF
THE ERN CANADIAN TROUGH WILL BRING PERIODIC SHRA TO WEST AND CENTRAL
UPPER MI MAINLY FOR EARLY TO MID NEXT WEEK.
SAT-SUN...THE WEEKEND LOOKS DRY WITH LOW-LEVEL FLOW BECOMING
INCREASINGLY ANTICYCLONIC AS SFC-H85 HIGH PRESSURE EXPANDS FROM
CENTRAL CANADA ACROSS MUCH OF THE GREAT LAKES REGION. 5H COLD POOL
SLIDES EAST...TAKING STEEPER MID-LVL LAPSE RATES WITH IT...SO NOT
EXPECTING ANY DIURNAL AFTERNOON SHRA. TEMPS SATURDAY WILL BE ON THE
COOLER SIDE OF NORMAL ESPECIALLY NEAR LK SUPERIOR WHERE 60S READINGS
ARE EXPECTED WITH ONSHORE NW WINDS. WARMEST TEMPS WILL BE FAR SOUTH
CENTRAL AWAY FROM THE COOLING INFLUENCE OF LAKE SUPERIOR...EXPECT
READINGS THERE IN THE LOWER TO MID 70S. TEMPS ON SUNDAY SHOULD REACH
THE 70S OVER MUCH OF THE AREA...EXCEPT LOCALLY COOLER 60S READINGS
NEAR THE GREAT LAKES SHORELINES.
MON-TUE...MODELS INDICATE RETURN SW FLOW OF HIGHER SFC DEW POINTS
INTO THE AREA FOR MONDAY INTO TUESDAY AS SFC RDG AXIS SLIDES TO THE
EAST. THE INCREASED MOISTURE ALONG WITH PERIODIC SHORTWAVES AND THE
APPROACH OF A FRONTAL BOUNDARY FM THE NW WILL WARRANT CARRYING SOME
LOW CHC POPS FOR SHRA/ISOLD TSRA MAINLY CENTRAL AND EAST WHERE
INSTABILITY WILL BE GREATEST AND LOW-LVL CONVERGENCE WILL BE AIDED
BY LAKE BREEZES.
WED-THU...THE 12Z ECMWF IS STILL THE SLOWEST MOVING THROUGH INITIAL
COLD FRONT AND HAS IT POSITIONED OVER THE SCNTRL AND ERN CWA AT 12Z
WED. THUS...WILL NEED TO MAINTAIN LOW CHC POPS FOR SHRA OVER THESE
AREAS ON WED. ECMWF CONTINUES TO MAINTAIN DEEPER CLOSED LOW OVER THE
UPPER GREAT LAKES ON THU AND THE 12Z RUN SHOWS A STRONG SHORTWAVE
MOVING THROUGH THE AREA THU AFTERNOON WHILE DEVELOPING AFTERNOON
SHRA OVER THE CENTRAL AND ERN FCST AREA. THE ECMWF IS THE ONLY ONE
OF THE 12Z MODELS TO SHOW THIS STRONG SHORTWAVE/CLOSED LOW ROTATING
THROUGH THE AREA. SO FOR NOW GIVEN MODEL UNCERTAINTY WILL ONLY HAVE
SLIGHT CHC POPS FOR SHRA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 139 AM EDT FRI AUG 2 2013
SCATTERED SHOWERS WITH EMBEDDED THUNDERSTORMS HAVE SPREAD INTO THE
WESTERN UPPER PENINSULA AHEAD OF A WEAK UPPER DISTURBANCE. THESE
SHOWERS SHOULD RAPIDLY MOVE EAST THROUGH THE AREA BY 12Z. AS ANY
SHOWER MOVES OVERHEAD...CONDITIONS MAY BRIEFLY DROP TO MVFR
ESPECIALLY AT IWD AND CMX...BUT OVERALL CONDITIONS SHOULD REMAIN VFR
OVERNIGHT. GENERALLY QUIET DAY ON FRIDAY WITH DRY AIR MOVING ACROSS
THE REGION. COULD SEE A SHOWER OR STORM ALONG THE LAKE BREEZE IN THE
EASTERN PART OF UPPER MICHIGAN FRI AFTN AS ANOTHER UPPER DISTURBANCE
PASSES BY...BUT THE EXPECTATION IS THAT THESE WILL STAY OUT OF THE
TERMINALS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 409 PM EDT THU AUG 1 2013
QUIET WEATHER WILL CONTINUE ACROSS LAKE SUPERIOR THROUGH THE
PERIOD...WITH WINDS REMAINING UNDER 20 KNOTS. A SERIES OF WEAK
TROUGHS WILL CROSS THE LAKE THROUGH FRIDAY AFTERNOON AND BRING SMALL
CHANCES OF SHOWERS. HIGH PRESSURE WILL THEN TAKE HOLD OF THE UPPER
GREAT LAKES FOR THE WEEKEND. ANOTHER TROUGH WILL TRACK SOUTHEAST
FROM NORTHERN ONTARIO INTO THE UPPER GREAT LAKES MONDAY NIGHT INTO
TUESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...MRD
SHORT TERM...KLUBER
LONG TERM...VOSS
AVIATION...MRD
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS GAYLORD MI
1202 AM EDT FRI AUG 2 2013
.SYNOPSIS...
ISSUED AT 407 PM EDT THU AUG 1 2013
A SERIES OF WEAK DISTURBANCES WILL DRIFT INTO NORTHERN MICHIGAN
THROUGH FRIDAY...BRINGING LOW CHANCES OF SHOWERS AND POSSIBLY A
THUNDERSTORM. THE BEST CHANCE WILL BE IN NORTHEAST LOWER
MICHIGAN BUT MOST COMMUNITIES WILL SEE RATHER PLEASANT WEATHER.
HIGH PRESSURE WILL BUILD INTO THE WESTERN GREAT LAKES OVER THE
WEEKEND...RESULTING IN COOLER AND RAIN FREE WEATHER. THE NEXT
CHANCE FOR RAIN DOES NOT ARRIVE UNTIL NEXT WORK WEEK.
&&
.UPDATE...
ISSUED AT 1012 PM EDT THU AUG 1 2013
A SOMEWHAT UNCERTAIN NIGHTTIME FORECAST. FIRST...A RENEGADE SHRA
IS STEADILY CROSSING LAKE MI...HEADING TOWARD THE COAST BETWEEN
FRANKFORT AND EMPIRE. IT ISN/T TERRIBLY HEALTHY LOOKING...BUT HAS
HELD TOGETHER BETTER THAN ANYTHING ELSE TO THIS POINT. VERY SHORT-
TERM GRIDS CONTINUE TO BE UPDATED TO ACCOUNT FOR A FEW SHRA LATE
THIS EVENING.
THE OVERNIGHT...IN THE BIG PICTURE...FEATURES LOWERING HEIGHTS AND
STEEPENING MID-LEVEL LAPSE RATES (TO 6.25-6.5C/KM 700-500MB). WV
IMAGERY SHOWS A SHORTWAVE MOVING ESE-WARD ACROSS NORTHERN MN...AS
MOST MODELS INDICATE. WAVE WILL REACH CENTRAL TO NORTHERN LOWER MI
TOWARD MORNING. CURRENTLY...MOST OF THE SHRA/TSRA ACTIVITY IS
ALONG THE NORTHERN FLANK OF THE WAVE...OVER FAR NORTHERN MN AND
ADJOINING PORTIONS OF CANADA. AT THE LOW LEVELS...WNW-ERLY FLOW WILL
PERSIST FROM 850MB ON DOWN...PERHAPS SOME VERY SHALLOW BACKING AT
950MB TOWARD 12Z. STILL...NOTHING RESEMBLING A CLASSIC LOW LEVEL JET.
SHORT-TERM HI-REZ MODELS ARE ALL OVER THE PLACE. THE NAM BRINGS
PRECIP INTO WESTERN SECTIONS BY DAWN...THE RUC DOES THE SAME TO
NORTHERN/EASTERN SECTIONS...THE WRF-NMM TO THE SOUTH...THE LOCAL
4KM WRF TO NOBODY.
GIVEN WHERE PRECIP IS NOW IN RELATION TO WHERE THE SHORTWAVE IS
PROGGED TO GO...FAVORS THE GOING FORECAST...WHICH HAS THE HIGHEST
POPS IN EASTERN UPPER INTO SOME SECTIONS OF FAR NE LOWER (RUC-
LIKE). THAT SAID...ALSO AGREE IN KEEPING AT LEAST A SLIGHT CHANCE
IN ALL AREAS AFTER 09Z.
MINOR CHANGES AT MOST TO CLOUD COVER AND MINS.
UPDATE ISSUED AT 703 PM EDT THU AUG 1 2013
DIURNAL CONVECTION OVER NORTHERN MI SEEMS TO HAVE JUST ABOUT RUN
ITS COURSE. INSTABILITY OVER FAR SE UPPER MI...AND IN THE SAGINAW
BAY REGION...HAS BEEN JUST ABOUT USED UP. SPC MESO PAGE INDICATING
LESS THAN 500J/KG ACROSS THE ENTIRE FORECAST AREA...WITH THE
HIGHEST POCKET IN NE LOWER S OF APN. INCOMING CONVECTIVE REMNANTS
HAVE MOVED INTO NW LOWER WITHOUT REGENERATION. SHOULD BE ABLE TO
GET AWAY WITH ISOLATED POPS FOR THE COUPLE OF HOURS OR SO...AND
NOTHING THEREAFTER.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CENTERED OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WHILE A VERY PERSISTENT UPPER TROUGH
REMAINS OVER CENTRAL CANADA AND THE GREAT LAKES REGION. THIS PATTERN
WILL SWEEP A COUPLE BOUNDARIES OVER NRN MI...MAINLY FRIDAY. AN UPPER
LVL COLD POOL ASSOCIATED WITH THE 500MB TROUGH NEAR HUDSON BAY WILL
CONTINUE TO SINK INTO THE NORTHERN LAKES THROUGH FRIDAY...HELPING
KEEP TEMPS AT MID LEVELS AROUND 8C/9C WHILE 500MB TEMPS DROP TO
-18C. THIS VERTICAL TEMPERATURE PROFILE WILL STEEPEN MID LEVEL
LAPSE RATES TO NEARLY 6C/KM TONIGHT INTO FRIDAY EVENING. EXPECT
CONVECTION THIS AFTERNOON WILL DIMINISH THIS EVENING WITH LACK OF
SOLAR RADIATION AND PRESENCE OF ANY BOUNDARY...THOUGH BECOME MORE
WIDESPREAD FRIDAY AFTERNOON ONCE AGAIN IN ADVANCE OF APPROACHING
SURFACE AND UPPER LEVEL FEATURES. MODEL SOUNDINGS SHOWING THE BEST
CONVERGENCE ASSOCIATED WITH APPROACHING BOUNDARIES FRIDAY...TO
FINALLY EXIT EAST INTO LAKE HURON AFTER 18Z FRIDAY.
OVERALL WILL KEEP SMALL CHC`S OF SHOWERS AND THUNDERSTORMS ACROSS
THE CWA TONIGHT AND FRIDAY. WILL MENTION HIGH TEMPS FRIDAY SIMILAR
TO THURSDAY TEMP VALUES...IN THE LOWER 70S...AS UPPER TROUGH AND
850/500MB TEMPS REMAIN THE SAME.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 407 PM EDT THU AUG 1 2013
OVERVIEW: 4-WAVE LONGWAVE PATTERN IN PLACE ACROSS THE NORTHERN
HEMISPHERE TO START THIS FORECAST PERIOD...ONE LONG WAVE TROUGH AXIS
BISECTED THE MIDWEST (AROUND 90W) AND BOUNDED BY RIDGING ALONG EACH
COAST. THIS PATTERN IS FORECAST TO CHANGE VERY LITTLE THROUGH THE
EXTENDED FORECAST...ALTHOUGH WITH SLOW EASTWARD MIGRATION OF THE
LONGWAVE TROUGH INTO THE GREAT LAKES/NEW ENGLAND AND SHARP
RIDGING/VERY WARM TEMPS IN THE WEST. THIS KEEPS OVERALL COOL/BELOW
NORMAL TEMPS INTACT FOR THE REGION THROUGH NEXT WEEK.
WEATHER-WISE THROUGH SUNDAY...WE START OUT ON THE UNSETTLED SIDE OF
THINGS FOR THE END OF THE WORK WEEK AS A COUPLE SHORT WAVES DIP
THROUGH THE GREAT LAKES REGION. HOWEVER...DEVELOPING NW FLOW ALOFT
FRIDAY NIGHT AND HEADING INTO THE WEEKEND LEADS TO A LARGE EXPANSE
OF HIGH PRESSURE BUILDING ACROSS THE NRN PLAINS THROUGH THE GREAT
LAKES. THIS WILL SET THE STAGE FOR QUIET WEATHER FOR THIS UPCOMING
WEEKEND...ALBEIT CONTINUED COOL-ISH WITH DAYTIME TEMPS RUNNING
AROUND 10 DEGREES BELOW NORMAL.
MONDAY THROUGH THURSDAY...QUIET WEATHER TO START NEXT WORK WEEK WITH
HIGH PRESSURE/NORTHWEST FLOW ALOFT AND COOLER TEMPS STILL SETTLED
OVER THE REGION. THEN...TUESDAY THROUGH THURSDAY BECOMES A BIT MORE
NEBULOUS AS STRONGER SHORT WAVE AND ASSOCIATED CLOSED LOW DROP OUT
OF CENTRAL CANADA DOWN INTO THE MIDWEST/GREAT LAKES. MODEL
TIMING/RUN-TO-RUN DIFFERENCES REGARDING THE PATTERN EVOLUTION ADD TO
THE UNCERTAINTY AS THE ECMWF TURNS DOWNRIGHT COOL ONCE AGAIN BY LATE
NEXT WEEK WITH ANOTHER CLOSED LOW/POCKET OF COOL AIR DESCENDING OVER
THE GREAT LAKES (BY COMPARISON...GFS IS MORE PROGRESSIVE AND
WARMER). WILL HAVE CHANCY POPS AND BELOW NORMAL TEMPS THROUGH THE
TUESDAY-THURSDAY TIMEFRAME GIVEN THE PROXIMITY TO THE TIGHTER
BAROCLINIC ZONE... ALTHOUGH A FAIR AMOUNT OF UNCERTAINTY SURROUNDS
THIS TIMEFRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1158 PM EDT THU AUG 1 2013
MAINLY VFR...THOUGH PRECIP COULD PRODUCE BRIEF RESTRICTIONS VERY
LATE TONIGHT INTO FRIDAY. ALSO SOME EARLY AM FOG AT PLN.
LOW PRESSURE ON HUDSON BAY CONTINUES TO PUSH OCCASIONAL COLD
FRONTS ACROSS NORTHERN MI. THE NEXT WILL MOVE ACROSS THE AREA
FRIDAY AFTERNOON. SOME SHRA CONTINUE TO PERCOLATE OVER LAKE MI
AHEAD OF THIS SYSTEM. SOMEWHAT MORE WIDESPREAD SHRA WILL DEVELOP
ESE-WARD INTO EASTERN UPPER AND FAR NORTHERN LOWER...INCLUDING
PLN/APN. ANOTHER ROUND OF SHRA/PERHAPS TSRA WILL DEVELOP AHEAD OF
THE FRONT...MAINLY OVER N CENTRAL LOWER MI AND POINTS EAST
(AGAIN...APN/PLN HAVE THE BEST CHANCE OF BEING IMPACTED).
LIGHT WINDS TONIGHT...STARTING OUT FROM THE SW FRIDAY MORNING THEN
VEERING NW TO N IN THE AFTERNOON/EVENING (BECOMING NE OFF THE
LAKE AT APN).
&&
.MARINE...
ISSUED AT 407 PM EDT THU AUG 1 2013
A STORM SYSTEM CURRENTLY OVER HUDSON BAY WILL REMAIN NEARLY
STATIONARY INTO THE WEEKEND...WITH A COUPLE OF WEAK BOUNDARIES
SWEEPING OVER THE GREAT LAKES THROUGH FRIDAY. EXPECT WINDS AND
WAVES TO REMAIN BELOW SCA CRITERIA THRU THE PERIOD...WITH WESTERLY
WINDS TONIGHT TRENDING NORTHWEST BY FRIDAY. &&
&&
.APX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LH...NONE.
LM...NONE.
LS...NONE.
&&
$$
UPDATE...JZ
SYNOPSIS...NS
SHORT TERM...SR
LONG TERM...BA
AVIATION...JZ
MARINE...SR
AREA FORECAST DISCUSSION
NWS JACKSON MS
1007 AM CDT FRI AUG 2 2013
.UPDATE...
SURFACE HIGH PRESSURE IS SITUATED OFF TO OUR NORTH IN THE MID
MISSISSIPPI VALLEY. ALTOGETHER...STILL EXPECTING A QUIET DAY. AN
ISOLATED STORM IN THE SOUTH TODAY CANNOT BE RULED OUT THOUGH. THERE
IS EVEN A CHANCE OF A MICROBURST IF ONE DOES FORM. SOME HIGH CIRRUS
COVERS MUCH OF THE CWA NOW. NO ADJUSTMENTS TO THE FORECAST WERE
NEEDED THIS MORNING. /10/
&&
.AVIATION...
EXPECT VFR CONDITIONS FOR THE REST OF THE DAY AND THROUGH THE
EVENING. AN ISOLATED SHOWER OR STORM IS POSSIBLE ALONG AND SOUTH OF
THE I-20 CORRIDOR TODAY...BUT CHANCES OF HITTING A TAF SITE ARE QUITE
LOW. LATE TONIGHT AND EARLY SATURDAY MORNING... POTENTIAL FOR AT
LEAST MVFR STRATUS OR MIST WILL EXIST PRIMARILY AT
JAN/HKS/MEI/NMM/PIB/HBG. EXPECT ANY FOG/STRATUS TO BURN OFF BY MID
MORNING SATURDAY WITH VFR CONDITIONS THEN ANTICIPATED FOR THE
AFTERNOON AND EVENING. /BB/EC/
&&
.PREV DISCUSSION... /ISSUED 415 AM CDT FRI AUG 2 2013/
SHORT TERM...TODAY THROUGH SATURDAY NIGHT...ANOTHER HOT DAY ON TAP
TODAY...ESPECIALLY IN THE SOUTHWEST HALF OF THE REGION WHERE THE
AIRMASS WILL BE MORE HUMID. BOUNDARY THAT PUSHED THROUGH YESTERDAY
TRIGGERING AFTERNOON SHOWERS AND STORMS IN SOUTH MS IS NOW RATHER
WASHED OUT NEAR THE COAST WITH CURRENT SURFACE REFLECTION OF LOWER
HUMIDITY AND TEMPS REALLY ONLY VERY EVIDENT FROM GREENVILLE SOUTH TO
MERIDIAN AND POINTS NORTHEAST. MOISTURE POOLED AT 5000 FEET ABOVE
GROUND DUE TO THE BOUNDARY IS NOW EVIDENT ALONG AND SOUTH OF I-20 AS
SCATTERED CLOUDS. PREVIOUS EXPECTATIONS WERE FOR VERY MINIMAL RAIN
CHANCES TODAY BUT NOW IT SEEMS AT LEAST VERY ISOLATED SHOWERS AND
STORMS WILL LIKELY TRIGGER IN MANY CENTRAL AND SOUTHERN ZONES THANKS
TO THE RESERVOIR OF POOLED MOISTURE. LATEST HRRR EXPLICIT OUTPUT
SUGGESTS AS MUCH. DO NOT THINK THIS ACTIVITY WILL ULTIMATELY WET
MANY PEOPLE OR CUT HEAT...BUT IT WAS WORTH MENTIONING IN FORECAST.
HIGHS WILL RANGE FROM 94 TO 97 WITH HOTTEST TEMPS IN CENTRAL AND
SOUTHERN ZONES WHERE PEAK HEAT INDICES MAY MEET OR EXCEED 105 FOR AN
HOUR OR TWO IN SOME SPOTS...ESPECIALLY WEST OF THE MS RIVER.
CONSIDERED A HEAT ADVISORY FOR THESE AREAS BUT EXPLICIT CRITERIA NOT
QUITE BEING MET.
TONIGHT...LARGE CURRENT SOUTHEAST PROPAGATING MCS IN EASTERN KANSAS
COULD HAVE A COUSIN CLOSER TO THE VICINITY OF MY NORTHWEST ZONES BY
THE WEE HOURS. CHANCES FOR ANY PRECIPITATION IN SUCH A SCENARIO
GETTING INTO THE REGION BEFORE DAWN ARE VERY LOW...BUT DEBRIS CLOUDS
BLOWING DOWNSTREAM COULD HOLD UP TEMPS SOMEWHAT. OTHERWISE...EXPECT
QUIET CONDITIONS WITH POTENTIAL FOR BUILDING SOUTHERLY FLOW TO
PRODUCE SOME LOW STRATUS IN SOUTHERN HALF OF ZONES BY DAWN SATURDAY.
SATURDAY AND SATURDAY NIGHT...ANY EARLY MORNING MCS ACTIVITY
REFERRED TO ABOVE SHOULD BE DECAYING AS IT TRIES TO ENTER INTO THE
REGION FROM THE NORTHWEST THROUGH THE FIRST HALF OF THE DAY.
WILDCARD OF A POTENTIAL MCV SPURRING SOME CONVECTION IN THE
NORTHEAST HALF OF ZONES WARRANTS SLIGHT CHANCE OF SHOWERS AND STORMS
MENTION...BUT ONLY THAT MUCH SINCE MANY OTHER FACTORS REMAIN RATHER
HOSTILE TO ANY MORE THAN ISOLATED COVERAGE. REGARDLESS OF WHETHER
THERE IS ACTUAL PRECIP HITTING THE GROUND ANYWHERE...CHANCES ARE
GOOD THERE WILL BE A FAIR AMOUNT OF HIGH TO MID LEVEL CLOUDS AROUND
TO REDUCE INSOLATION A BIT. THIS EXPLAINS MEX TEMPS A LITTLE COOLER
THAN TODAY IN MANY AREAS. HUMIDITY WILL BE INCREASING ACROSS THE
BOARD THOUGH AND PEAK HEAT INDEX WILL COME CLOSE OR EXCEED 100
DEGREES IN MOST LOCATIONS. BY SATURDAY NIGHT THE POTENTIAL FOR
JUXTAPOSITION OF CONVECTIVE BOUNDARIES...NON-TRIVIAL MOISTURE
CONVERGENCE...AND PASSING WEAK DISTURBANCES IN NORTHWEST FLOW
SUGGEST SOME CHANCE OF SOUTHERN FRINGE OF TN VALLEY AND MIDSOUTH
THUNDERSTORM ACTIVITY BRUSHING NORTHERN HALF OF ZONES. ONLY SLIGHT
CHANCE POPS FOR NOW. /BB/
LONG TERM...SUNDAY THROUGH NEXT FRIDAY...MODELS CONTINUE TO AGREE
WITH KEEPING THE MID/UPPER RIDGE WEDGED INTO THE FORECAST AREA FROM
THE WEST THROUGH AT LEAST THE MID-RANGE PORTION OF THE FORECAST...
BEFORE SHIFTING IT EAST AND NEARLY DIRECTLY OVER THE ARKLAMISS
DURING THE EXTENDED. THE BEST RAIN CHANCES CONTINUE TO LOOK TO BE
FAIRLY EARLY IN THE PERIOD...SPECIFICALLY SUNDAY...MONDAY...AND
TUESDAY AFTERNOONS...AND ON THE EASTERN PERIPHERY OF THIS RIDGE AS
NORTHERLY FLOW TRIES TO SETUP OVER REGION. THIS IN ADDITION TO
INCREASED LOW LEVEL MOISTURE AND A WEAK SURFACE BOUNDARY THAT`S
PROGGED TO DROP SOUTH INTO THE CWA SUNDAY...AND EVENTUALLY WASHOUT
ON TUESDAY. CHANCES FOR SHOWERS AND STORMS WILL LINGER THROUGH THE
REMAINDER OF THE FORECAST PERIOD...WEDNESDAY THROUGH FRIDAY...BUT
CHANCES WILL BE LOWER AND THE CENTER OF THE RIDGE IS AGAIN EXPECTED
TO SHIFT ALMOST DIRECTLY OVER THE FORECAST AREA.
I DIDN`T STRAY FAR FROM GFS GUIDANCE IN TERMS OF TEMPERATURES.
OVERALL...HIGHS EACH AFTERNOON WILL CLIMB INTO THE MIDDLE 90S WITH
PLENTY OF HUMIDITY PRESENT AS DEW POINTS GENERALLY SIT AROUND 70F.
THIS LOOKS TO YIELD A FEW PERIODS THROUGHOUT EACH DAY WHERE HEAT
INDICES COULD CLIMB BETWEEN 100-105F. THAT SAID...FORECAST HIGHS
COULD OBVIOUSLY BE LOWER IF CLOUD COVER AND/OR CONVECTION ARE MORE
PREVALENT...WHICH IN TURN WOULD HELP KEEP HEAT INDEX VALUES IN
CHECK. LOWS EACH NIGHT WILL REMAIN MILD AND ONLY FALL INTO THE
MIDDLE 70S. /19/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 97 73 95 76 / 11 9 16 16
MERIDIAN 95 71 95 74 / 3 9 17 16
VICKSBURG 96 73 95 73 / 11 8 13 13
HATTIESBURG 97 74 96 75 / 11 10 10 10
NATCHEZ 95 74 95 74 / 11 9 10 8
GREENVILLE 95 74 95 76 / 3 11 20 20
GREENWOOD 95 71 95 75 / 3 8 21 20
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON MS
415 AM CDT FRI AUG 2 2013
.SHORT TERM...TODAY THROUGH SATURDAY NIGHT...ANOTHER HOT DAY ON TAP
TODAY...ESPECIALLY IN THE SOUTHWEST HALF OF THE REGION WHERE THE
AIRMASS WILL BE MORE HUMID. BOUNDARY THAT PUSHED THROUGH YESTERDAY
TRIGGERING AFTERNOON SHOWERS AND STORMS IN SOUTH MS IS NOW RATHER
WASHED OUT NEAR THE COAST WITH CURRENT SURFACE REFLECTION OF LOWER
HUMIDITY AND TEMPS REALLY ONLY VERY EVIDENT FROM GREENVILLE SOUTH TO
MERIDIAN AND POINTS NORTHEAST. MOISTURE POOLED AT 5000 FEET ABOVE
GROUND DUE TO THE BOUNDARY IS NOW EVIDENT ALONG AND SOUTH OF I-20 AS
SCATTERED CLOUDS. PREVIOUS EXPECTATIONS WERE FOR VERY MINIMAL RAIN
CHANCES TODAY BUT NOW IT SEEMS AT LEAST VERY ISOLATED SHOWERS AND
STORMS WILL LIKELY TRIGGER IN MANY CENTRAL AND SOUTHERN ZONES THANKS
TO THE RESERVOIR OF POOLED MOISTURE. LATEST HRRR EXPLICIT OUTPUT
SUGGESTS AS MUCH. DO NOT THINK THIS ACTIVITY WILL ULTIMATELY WET
MANY PEOPLE OR CUT HEAT...BUT IT WAS WORTH MENTIONING IN FORECAST.
HIGHS WILL RANGE FROM 94 TO 97 WITH HOTTEST TEMPS IN CENTRAL AND
SOUTHERN ZONES WHERE PEAK HEAT INDICES MAY MEET OR EXCEED 105 FOR AN
HOUR OR TWO IN SOME SPOTS...ESPECIALLY WEST OF THE MS RIVER.
CONSIDERED A HEAT ADVISORY FOR THESE AREAS BUT EXPLICIT CRITERIA NOT
QUITE BEING MET.
TONIGHT...LARGE CURRENT SOUTHEAST PROPAGATING MCS IN EASTERN KANSAS
COULD HAVE A COUSIN CLOSER TO THE VICINITY OF MY NORTHWEST ZONES BY
THE WEE HOURS. CHANCES FOR ANY PRECIPITATION IN SUCH A SCENARIO
GETTING INTO THE REGION BEFORE DAWN ARE VERY LOW...BUT DEBRIS CLOUDS
BLOWING DOWNSTREAM COULD HOLD UP TEMPS SOMEWHAT. OTHERWISE...EXPECT
QUIET CONDITIONS WITH POTENTIAL FOR BUILDING SOUTHERLY FLOW TO
PRODUCE SOME LOW STRATUS IN SOUTHERN HALF OF ZONES BY DAWN SATURDAY.
SATURDAY AND SATURDAY NIGHT...ANY EARLY MORNING MCS ACTIVITY
REFERRED TO ABOVE SHOULD BE DECAYING AS IT TRIES TO ENTER INTO THE
REGION FROM THE NORTHWEST THROUGH THE FIRST HALF OF THE DAY.
WILDCARD OF A POTENTIAL MCV SPURRING SOME CONVECTION IN THE
NORTHEAST HALF OF ZONES WARRANTS SLIGHT CHANCE OF SHOWERS AND STORMS
MENTION...BUT ONLY THAT MUCH SINCE MANY OTHER FACTORS REMAIN RATHER
HOSTILE TO ANY MORE THAN ISOLATED COVERAGE. REGARDLESS OF WHETHER
THERE IS ACTUAL PRECIP HITTING THE GROUND ANYWHERE...CHANCES ARE
GOOD THERE WILL BE A FAIR AMOUNT OF HIGH TO MID LEVEL CLOUDS AROUND
TO REDUCE INSOLATION A BIT. THIS EXPLAINS MEX TEMPS A LITTLE COOLER
THAN TODAY IN MANY AREAS. HUMIDITY WILL BE INCREASING ACROSS THE
BOARD THOUGH AND PEAK HEAT INDEX WILL COME CLOSE OR EXCEED 100
DEGREES IN MOST LOCATIONS. BY SATURDAY NIGHT THE POTENTIAL FOR
JUXTAPOSITION OF CONVECTIVE BOUNDARIES...NON-TRIVIAL MOISTURE
CONVERGENCE...AND PASSING WEAK DISTURBANCES IN NORTHWEST FLOW
SUGGEST SOME CHANCE OF SOUTHERN FRINGE OF TN VALLEY AND MIDSOUTH
THUNDERSTORM ACTIVITY BRUSHING NORTHERN HALF OF ZONES. ONLY SLIGHT
CHANCE POPS FOR NOW. /BB/
.LONG TERM...SUNDAY THROUGH NEXT FRIDAY...MODELS CONTINUE TO AGREE
WITH KEEPING THE MID/UPPER RIDGE WEDGED INTO THE FORECAST AREA FROM
THE WEST THROUGH AT LEAST THE MID-RANGE PORTION OF THE FORECAST...
BEFORE SHIFTING IT EAST AND NEARLY DIRECTLY OVER THE ARKLAMISS
DURING THE EXTENDED. THE BEST RAIN CHANCES CONTINUE TO LOOK TO BE
FAIRLY EARLY IN THE PERIOD...SPECIFICALLY SUNDAY...MONDAY...AND
TUESDAY AFTERNOONS...AND ON THE EASTERN PERIPHERY OF THIS RIDGE AS
NORTHERLY FLOW TRIES TO SETUP OVER REGION. THIS IN ADDITION TO
INCREASED LOW LEVEL MOISTURE AND A WEAK SURFACE BOUNDARY THAT`S
PROGGED TO DROP SOUTH INTO THE CWA SUNDAY...AND EVENTUALLY WASHOUT
ON TUESDAY. CHANCES FOR SHOWERS AND STORMS WILL LINGER THROUGH THE
REMAINDER OF THE FORECAST PERIOD...WEDNESDAY THROUGH FRIDAY...BUT
CHANCES WILL BE LOWER AND THE CENTER OF THE RIDGE IS AGAIN EXPECTED
TO SHIFT ALMOST DIRECTLY OVER THE FORECAST AREA.
I DIDN`T STRAY FAR FROM GFS GUIDANCE IN TERMS OF TEMPERATURES.
OVERALL...HIGHS EACH AFTERNOON WILL CLIMB INTO THE MIDDLE 90S WITH
PLENTY OF HUMIDITY PRESENT AS DEW POINTS GENERALLY SIT AROUND 70F.
THIS LOOKS TO YIELD A FEW PERIODS THROUGHOUT EACH DAY WHERE HEAT
INDICES COULD CLIMB BETWEEN 100-105F. THAT SAID...FORECAST HIGHS
COULD OBVIOUSLY BE LOWER IF CLOUD COVER AND/OR CONVECTION ARE MORE
PREVALENT...WHICH IN TURN WOULD HELP KEEP HEAT INDEX VALUES IN
CHECK. LOWS EACH NIGHT WILL REMAIN MILD AND ONLY FALL INTO THE
MIDDLE 70S. /19/
&&
.AVIATION...POTENTIAL FOR MVFR MIST AND HAZE BEFORE 10 AM THIS
MORNING AT GLH/GWO/GTR/CBM/MEI/NMM...WHILE MVFR TO TEMPORARILY IFR
CEILINGS AND VIS POSSIBLE THROUGH THAT TIME AT PIB/HBG WHERE THE
GROUND IS DAMP FROM YESTERDAY`S RAINS. AFTER 10 AM EXPECT VFR
CONDITIONS THE REST OF THE DAY AND THROUGH THE EVENING WITH LIGHT
AND ERRATIC WINDS. AN ISOLATED SHOWER OR STORM IS POSSIBLE ALONG AND
SOUTH OF I-20 TODAY...BUT CHANCES OF HITTING TAF SITE ARE QUITE LOW.
LATE TONIGHT POTENTIAL FOR AT LEAST MVFR STRATUS OR MIST WILL EXIST
PRIMARILY AT JAN/HKS/MEI/NMM/PIB/HBG. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 97 73 95 76 / 11 9 16 16
MERIDIAN 95 71 95 74 / 3 9 17 16
VICKSBURG 96 73 95 73 / 11 8 13 13
HATTIESBURG 97 74 96 75 / 11 10 10 10
NATCHEZ 95 74 95 74 / 11 9 10 8
GREENVILLE 95 74 95 76 / 3 11 20 20
GREENWOOD 95 71 95 75 / 3 8 21 20
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/19
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
933 PM CDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 933 PM CDT SAT AUG 3 2013
GOING FORECAST STILL LOOKS ON TRACK. SLIGHTLY DRIER AIR CONTINUES
TO ADVECT INTO THE AREA WHICH HAS CAUSED DEWPOINTS TO LOWER THIS
EVENING. SKIES HAVE CLEARED OUT IN MANY LOCATIONS...THOUGH
CONVECTIVE DEBRIS CLOUDS ARE MOVING QUICKLY EASTWARD ACROSS
NORTHERN MO THAT WILL SPREAD ACROSS THE CWA THE NEXT FEW HOURS.
THESE FACTORS SHOULD LIMIT FOG DEVELOPMENT TONIGHT...THOUGH STILL
COULD SEE SOME FORMATION IN LOW LYING AREA. NEAREST THUNDERSTORMS
AT THIS HOUR ARE WELL WEST OF THE CWA IN CENTRAL AND WESTERN
PARTS OF OK/KS. LATEST RAP AND LOCAL WRF RUNS DO NOT BRING ANY LOW
LEVEL MOISTURE CONVERGENCE INTO CENTRAL MO UNTIL AT LEAST MID
MORNING SUNDAY...SO HAVE PUSHED BACK CHANCES OF SHOWERS AND
THUNDERSTORMS UNTIL AT LEAST 15Z.
BRITT
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 324 PM CDT SAT AUG 3 2013
RESIDUAL CLOUD COVER DUE TO THE MCS THAT MOVED SOUTHEASTWARD ACROSS
THE REGION EARLIER TODAY CONTINUES TO DIMINISH...AND WILL ALLOW FOR
PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVERNIGHT. REGARDING
PRECIPITATION CHANCES...HAVE GONE AHEAD AND REMOVED POPS OVERNIGHT
ACROSS SOUTHEASTERN AND CENTRAL MISSOURI. DESPITE ADDITIONAL
CONVECTION EXPECTED TO DEVELOP OVER EASTERN KANSAS AND GROW UPSCALE
INTO ANOTHER MCS...GIVEN THE SOUTHWARD PROGRESSION OF THE COLD FRONT
AND BUILDING HIGH PRESSURE...EXPECT THE PROPAGATION OF THE
CONVECTION TO HAVE A MORE SIGNIFICANT SOUTHERLY COMPONENT THAN SHOWN
BY THE MCS LAST NIGHT. RECENT MODEL OUTPUT FROM THE GFS...NAM...AND
ECMWF ECHO THIS IDEA WITH LITTLE IF ANY QPF ANYWHERE OVER THE CWA
PRIOR TO 12Z SUNDAY. THUS...A TRANQUIL EVENING IS EXPECTED ACROSS
THE AREA TONIGHT...WITH LOW TEMPERATURES RANGING FROM THE UPPER 50S
TO MID 60S...SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
JP
TRUETT
.LONG TERM...(SUNDAY THROUGH NEXT SATURDAY)
ISSUED AT 324 PM CDT SAT AUG 3 2013
AS WE HEAD INTO THE NEW WEEK...QUESTION BECOMES WHEN AND HOW HARD TO
HIT RETURN OF TSRA CHANCES ACROSS THE REGION. AS MENTIONED IN THE
SHORT TERM PORTION OF THE DISCUSSION STRONG INTRUSION OF SURFACE
HIGH TODAY AND TONIGHT...COUPLED WITH EFFECTS OF RAIN-COOLED AMS
FROM LAST NIGHTS MCS...HAS ALLOWED THE BEST INSTABILITY AND
BAROCLINICITY TO MAKE A SUBTLE BUT SIGNIFICANT SW SHIFT.
SO...WHILE THE E FRINGES OF OVERNIGHT CONVECTION MAY BE APPROACHING
OUR W COUNTIES ON SUNDAY MORNING...THE MORE STABLE AND DRIER AIR MAY
CAUSE THE PRECIP TO STRUGGLE TO MAKE TOO MUCH HEADWAY INTO OUR
CWA...ESPECIALLY SINCE LOW LEVEL FLOW MAINTAINS A FAIRLY
PRONOUNCED S COMPONENT THROUGHOUT THE DAY.
HOWEVER...ALL SYNOPTIC MODELS ARE FORECASTING THE LOW LEVEL JET TO
VEER AND BECOME FOCUSED ACROSS THE AREA SUNDAY NIGHT AS SURFACE
RIDGE RETREATS TO THE EAST. THIS WILL TRANSPORT INCREASINGLY MOIST
AND UNSTABLE AIR INTO THE REGION AND INDUCE ISENTROPIC ASCENT OVER
MOST OF NOT ALL OF THE CWA....LEADING TO A THREAT OF NOCTURNAL
CONVECTION FOR MOST OF THE AREA BY DAYBREAK MONDAY. ONCE THE
TSRA CHANCES RETURN SUNDAY NIGHT...IT WOULD APPEAR THAT A
THUNDERSTORM THREAT WILL REMAIN LOCKED OVER THE MID MISSISSIPPI
VALLEY THROUGH MIDWEEK AS DISTURBANCES IN THE NW MID LEVEL FLOW
WILL INTERACT WITH THE MOIST AND UNSTABLE AIRMASS THAT WILL BE
PARKED OVER THE CENTRAL CONUS.
PATTERN IS CERTAINLY ONE THAT COULD LEAD TO A SERIES OF
CONVECTIVE COMPLEXES TO PROPAGATE ACROSS THE AREA THROUGH TUESDAY.
AS IS TYPICAL MODELS ARE VARYING IN THE SPECIFICS OF
FORCING/THERMODYNAMICS AND EVOLUTION OF CONVECTION...BUT HAVE
BASED FORECAST TRENDS MORE ON EXPECTED SYNOPTIC PATTERN THAN ON
THE SPECIFICS OF ANY ONE MODEL. FOR NOW HAVE GONE WITH MIDDLE OF
THE ROAD CHANCE POPS...BUT FULLY EXPECT THAT THERE WILL BE LARGER
SWINGS IN POP NUMBERS AS THE DETAILS/TIMING OF EACH POTENTIAL MCS
BECOMES A BIT CLEARER IN THE NEAR TERM.
OBVIOUSLY...TEMPERATURE SPECIFICS WILL BE HIGHLY DEPENDENT ON TIMING AND
EXTENT OF CONVECTION...BUT FOR NOW HAVE MAINTAINED HIGHS IN THE
80S AND LOWS IN THE UPPER 60S TO LOWER 70S.
MEDIUM RANGE SOLUTIONS ARE NOW FORECASTING AN UPPER LOW TO DIP
INTO S CANADA AND CLIP THE UPPER GREAT LAKES DURING THE LATTER
HALF OF THE WEEK. LEAD SHORTWAVE AND ASSOCIATED COLD FRONT WILL
WORK ACROSS THE REGION WEDNESDAY AND INTO WEDNESDAY EVENING
CONTINUING A THREAT OF SHOWERS AND THUNDERSTORMS. HOWEVER...12Z GFS
AND ECMWF NOW SUGGESTING THAT PRIMARY BAROCLINIC ZONE WILL BE
SHIFTED INTO S MO AND N AR BY THE END OF THE WORK WEEK WITH COOLER
AND MORE STABLE DROPPING S INTO THE N AND MID MISSISSIPPI VALLEY.
BASED ON THIS PATTERN SHIFT HAVE LIMITED CHANCE POPS TO S SECTIONS
OF THE CWA ON THURSDAY AND FRIDAY.
TEMPERATURES DURING THE EXTENDED MAY NOT BE TOO MUCH DIFFERENT
THAN THOSE OF EARLY IN THE WEEK...BUT HUMIDITY LEVELS SHOULD BE LOWER.
TRUETT
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 631 PM CDT SAT AUG 3 2013
VFR FLIGHT CONDITIONS AND LIGHT NORTHEAST FLOW IS EXPECTED TO
PREVAIL FOR MOST OF THE NIGHT. THE FLOW WILL VEER MORE TO THE EAST
LATE TONIGHT...AND RIVER VALLEYS AND OTHER SHELTERED AREAS WILL
LIKELY DEVELOP SOME FOG. AREAS ALONG RIVERS MAY EVEN SEE IFR
CONDITIONS IN STEAM FOG...THO THINK VSBYS BETWEEN 3-5SM ARE MORE LIKELY.
ANY FOG THAT DOES FORM SHOULD DISSIPATE QUICKLY AFTER
SUNRISE...AND VFR CONDITIONS WILL CONTINUE ON SUNDAY.
SPECIFICS FOR KSTL...
EXPECT VFR FLIGHT CONDITIONS AND LIGHT NORTHEAST WIND TO PREVAIL
AT LAMBERT THROUGH TONIGHT. THE WIND WILL SHIFT TO A MORE EASTERLY
DIRECTION BEFORE SUNRISE SUNDAY MORNING. THERE WILL LIKELY BE SOME
RIVER VALLEY FOG IN THE VICINITY OF THE TERMINAL...BUT IT LOOKS
UNLIKELY TO IMPACT THE TERMINAL DIRECTLY. VFR CONDITIONS WILL
CONTINUE ON SUNDAY.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1259 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1150 AM CDT FRI AUG 2 2013
BELIEVE PERSISTENT 850MB WAA/ISENTROPIC ASCENT WILL CONTINUE
THREAT OF SHRA/TSRA ACROSS CENTRAL AND E MO THIS AFTERNOON...AND
ALLOW THE THREAT TO WORK EAST WITH TIME. ALTHOUGH THERE IS
TYPICALLY A LULL IN WAA-DRIVEN PRECIP IN THE WARM SEASON DURING
THE AFTERNOON BELIEVE THAT RAIN-COOLED AMS OVER CENTRAL
MO...COMBINED WITH INCREASING INSTABILITY UPSTREAM OVER E
KS...WILL ALLOW CONVECTION TO CONTINUE TO PERCOLATE THROUGHOUT THE
AFTERNOON HOURS. RUC AND NAM ARE ACTUALLY FORECASTING A
SIGNIFICANT UPSCALE GROWTH IN THE CONVECTION IN OUR AREA DURING
THE AFTERNOON...AND ALTHOUGH THE LOCATION MAY BE OFF CANT TOTALLY
DISAGREE WITH THIS GENERAL SCENARIO. GOING POP TRENDS...WHICH HAS
LIKELY POPS FROM MID MO INTO W CENTRAL IL...STILL LOOK REASONABLE
AND WILL CONTINUE WITH THEM...AND FINE TUNE AS EXACT TRENDS
BECOME A BIT MORE CLEAR.
TRUETT
&&
.SHORT TERM...(THROUGH SUNDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
MCS CURRENTLY OVER S NE AND N KS SHOULD CONTINUE TO PUSH SOUTHEAST
THROUGH THE EARLY MORNING HOURS WITH THE MAIN EFFECT OBSERVED
WITHIN OUR CWA THROUGH MIDDAY BEING BKN TO OVC DEBRIS CLOUDS. FAR
WESTERN SECTIONS OF THE CWFA MAY SEE A LIGHT SHOWER ON THE
EAST/NORTHEAST PERIPHERY OF THE STRATIFORM RAIN. ATTENTION THEN
TURNS TO THIS AFTERNOON AND EVENING AS SFC COLD FRONT SLOWLY
APPROACHES FROM THE NORTH/NORTHWEST. AFOREMENTIONED DEBRIS CLOUDS
MAY LIMIT INSTABILITY AND THUS SEVERE THREAT TODAY. HOWEVER...IF
MORE INSTABILITY IS REALIZED...THERE COULD BE A FEW STRONG TO
SEVERE STORMS GIVEN 30-40 KNOTS OF DEEP LAYER BULK SHEAR.
REGARDLESS...CHANCES OF SHOWERS AND STORMS DO LOOK TO INCREASE
FROM NORTHWEST TO SOUTHEAST AS A SHORTWAVE EMBEDDED WITHIN NW FLOW
ALOFT MOVES ACROSS THE MID MISSOURI VALLEY.
MODELS DEPICT LLJ BEING FOCUSING STRONG LL MOISTURE CONVERGENCE
AND INTERACTING WITH SFC BAROCLINIC ZONE OVER CENTRAL AND PORTIONS
OF SOUTHEAST MISSOURI OVERNIGHT FRIDAY. HAVE THEREFORE UPPED POPS
TO CATEGORICAL. ALSO COULD BE SOME LOCALLY HEAVY RAINFALL AS PWATS
ARE WELL ABOVE 2 INCHES IN SPOTS WITH A FAVORABLE CAPE PROFILE.
FOR THE WEEKEND...CLOSELY FOLLOWED THE GFS FOR SENSIBLE WEATHER AS
SFC FRONT SHOULD CONTINUE TO PROGRESS SOUTHWARD GIVEN NW MID/UPPER
LEVEL FLOW ALOFT AND FAIRLY STRONG PRESSURE RISES PROGGED BEHIND
THE FRONT. FOCUS FOR POPS THEN ALSO SHIFTS SOUTH INTO THE SOUTHERN
THIRD OF THE CWFA BY SATURDAY AFTERNOON WITH DRY/COLD ADVECTION
FURTHER TO THE NORTH. A MAJORITY OF THE AREA SHOULD STAY DRY
SATURDAY NIGHT AND INTO SUNDAY. EXCEPTION COULD BE PORTIONS OF
CENTRAL AND SOUTHEAST MISSOURI ONCE AGAIN WHERE 850 HPA FRONT IS
FORECAST TO NEVER QUITE MAKE IT THROUGH THE AREA. CHANCES OF
SHOWERS AND STORMS TO REMAIN THROUGH THE END OF THE WEEKEND IN
THIS REGION AS WARM MOIST AIR ALOFT RISES ABOVE THE SFC BAROCLINIC
ZONE TO THE SOUTH.
GOSSELIN
.LONG TERM...(MONDAY TO THURSDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
HAVE CHC POPS THROUGHOUT THE EXTENDED AS THE PERIOD WILL CONTINUE
TO BE DOMINATED BY NW FLOW ALOFT. TIMING INDIVIDUAL SHORTWAVES
AND ATTENDANT COLD FRONT IS VERY DIFFICULT SO DID NOT ADJUST POPS
TOO MUCH FOR THIS PERIOD FROM CR INIT. TEMPERATURES FOR THE PERIOD
SHOULD RUN SLIGHTLY BELOW NORMAL DURING THE DAY AND NEAR NORMAL AT
NIGHT DUE TO EXPECTED CLOUD COVER AND POPS. A STRONG NORTHERN
VORTEX LOOKS TO COME SOUTH TOWARD THE CONUS SOMETIME LATE NEXT
WEEK WHICH SHOULD YIELD DRIER AND UNSEASONABLY COOL WEATHER BEHIND
ITS PASSAGE.
GOSSELIN
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1243 PM CDT FRI AUG 2 2013
AS MENTIONED IN SHORT TERM UPDATE...ISENTROPIC ASCENT SHOULD
CONTINUE TO FUEL SHRA/TSRA OVER MUCH OF THE AREA THIS AFTERNOON.
GETTING THE IMPRESSION THAT UIN MAY BE ON THE N FRINGES OF THE
MAIN QPF AREA...WITH OTHER TAFS EXPERIENCING SOMEWHAT MORE IN THE
WAY OF PRECIP. OUTSIDE OF COU WHERE RADAR DATA MAKES CONVECTIVE
TRENDS A BIT MORE CLEAR FOR THE NEXT COUPLE OF HOURS...HAVE USED A
BROAD BRUSH APPROACH FOR ONSET OF FIRST PRECIP AND THEN OF
TS...AND WILL SIMPLY USE NOWCAST TECHNIQUES TO TWEEK THESE TRENDS.
FOR NOW THESE BROAD BRUSH TRENDS HOLD ONTO VFR...BUT OBVIOUSLY
WITH THE ASCENT OF THE MODERATLY UNSTABLE AIRMASS STRONGER STORMS
COULD CERTAINLY PRODUCE MUCH LOWER CIGS/VSBYS. ZONE OF WAA IS
FORECAST TO DEVELOP S THIS EVENING...AND BELIEVE MUCH OF THE
PRECIP WILL BE SOUTH OF ALL TAF LOCATIONS HEADING INTO THE PREDAWN
HOURS. MOS GUIDANCE AS WELL AS SREF AVIATION PROBABIILTIES HINT AT
DETERIORATING CONDITIONS N OF THE SWD PUSHING FRONTAL BOUNDARY
DURING THE PREDAWN HOURS...AND HAVE INTRODUCED THIS TREND.
SPECIFICS FOR KSTL...
VFR SHOWERS SHOULD THREATEN STL AREA EARLY THIS AFTERNOON...WITH
MORE ROBUST CONVECTION POSSIBLE BY MID AFTERNOON AS WAA PERSISTS
AND ELEVATED AMS CONTINUES TO DESTABILIZE OVER MSVLY. AS MENTIONED
ABOVE...FOR NOW HAVE USED A BROAD BRUSH APPROACH FOR TIMING...AND
WILL USE RADAR TRENDS TO FINE TUNE THIS TIMING.
TRUETT
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1151 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1150 AM CDT FRI AUG 2 2013
BELIEVE PERSISTENT 850MB WAA/ISENTROPIC ASCENT WILL CONTINUE
THREAT OF SHRA/TSRA ACROSS CENTRAL AND E MO THIS AFTERNOON...AND
ALLOW THE THREAT TO WORK EAST WITH TIME. ALTHOUGH THERE IS
TYPICALLY A LULL IN WAA-DRIVEN PRECIP IN THE WARM SEASON DURING
THE AFTERNOON BELIEVE THAT RAIN-COOLED AMS OVER CENTRAL
MO...COMBINED WITH INCREASING INSTABILITY UPSTREAM OVER E
KS...WILL ALLOW CONVECTION TO CONTINUE TO PERCOLATE THROUGHOUT THE
AFTERNOON HOURS. RUC AND NAM ARE ACTUALLY FORECASTING A
SIGNIFICANT UPSCALE GROWTH IN THE CONVECTION IN OUR AREA DURING
THE AFTERNOON...AND ALTHOUGH THE LOCATION MAY BE OFF CANT TOTALLY
DISAGREE WITH THIS GENERAL SCENARIO. GOING POP TRENDS...WHICH HAS
LIKELY POPS FROM MID MO INTO W CENTRAL IL...STILL LOOK REASONABLE
AND WILL CONTINUE WITH THEM...AND FINE TUNE AS EXACT TRENDS
BECOME A BIT MORE CLEAR.
TRUETT
&&
.SHORT TERM...(THROUGH SUNDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
MCS CURRENTLY OVER S NE AND N KS SHOULD CONTINUE TO PUSH SOUTHEAST
THROUGH THE EARLY MORNING HOURS WITH THE MAIN EFFECT OBSERVED
WITHIN OUR CWA THROUGH MIDDAY BEING BKN TO OVC DEBRIS CLOUDS. FAR
WESTERN SECTIONS OF THE CWFA MAY SEE A LIGHT SHOWER ON THE
EAST/NORTHEAST PERIPHERY OF THE STRATIFORM RAIN. ATTENTION THEN
TURNS TO THIS AFTERNOON AND EVENING AS SFC COLD FRONT SLOWLY
APPROACHES FROM THE NORTH/NORTHWEST. AFOREMENTIONED DEBRIS CLOUDS
MAY LIMIT INSTABILITY AND THUS SEVERE THREAT TODAY. HOWEVER...IF
MORE INSTABILITY IS REALIZED...THERE COULD BE A FEW STRONG TO
SEVERE STORMS GIVEN 30-40 KNOTS OF DEEP LAYER BULK SHEAR.
REGARDLESS...CHANCES OF SHOWERS AND STORMS DO LOOK TO INCREASE
FROM NORTHWEST TO SOUTHEAST AS A SHORTWAVE EMBEDDED WITHIN NW FLOW
ALOFT MOVES ACROSS THE MID MISSOURI VALLEY.
MODELS DEPICT LLJ BEING FOCUSING STRONG LL MOISTURE CONVERGENCE
AND INTERACTING WITH SFC BAROCLINIC ZONE OVER CENTRAL AND PORTIONS
OF SOUTHEAST MISSOURI OVERNIGHT FRIDAY. HAVE THEREFORE UPPED POPS
TO CATEGORICAL. ALSO COULD BE SOME LOCALLY HEAVY RAINFALL AS PWATS
ARE WELL ABOVE 2 INCHES IN SPOTS WITH A FAVORABLE CAPE PROFILE.
FOR THE WEEKEND...CLOSELY FOLLOWED THE GFS FOR SENSIBLE WEATHER AS
SFC FRONT SHOULD CONTINUE TO PROGRESS SOUTHWARD GIVEN NW MID/UPPER
LEVEL FLOW ALOFT AND FAIRLY STRONG PRESSURE RISES PROGGED BEHIND
THE FRONT. FOCUS FOR POPS THEN ALSO SHIFTS SOUTH INTO THE SOUTHERN
THIRD OF THE CWFA BY SATURDAY AFTERNOON WITH DRY/COLD ADVECTION
FURTHER TO THE NORTH. A MAJORITY OF THE AREA SHOULD STAY DRY
SATURDAY NIGHT AND INTO SUNDAY. EXCEPTION COULD BE PORTIONS OF
CENTRAL AND SOUTHEAST MISSOURI ONCE AGAIN WHERE 850 HPA FRONT IS
FORECAST TO NEVER QUITE MAKE IT THROUGH THE AREA. CHANCES OF
SHOWERS AND STORMS TO REMAIN THROUGH THE END OF THE WEEKEND IN
THIS REGION AS WARM MOIST AIR ALOFT RISES ABOVE THE SFC BAROCLINIC
ZONE TO THE SOUTH.
GOSSELIN
.LONG TERM...(MONDAY TO THURSDAY)
ISSUED AT 307 AM CDT FRI AUG 2 2013
HAVE CHC POPS THROUGHOUT THE EXTENDED AS THE PERIOD WILL CONTINUE
TO BE DOMINATED BY NW FLOW ALOFT. TIMING INDIVIDUAL SHORTWAVES
AND ATTENDANT COLD FRONT IS VERY DIFFICULT SO DID NOT ADJUST POPS
TOO MUCH FOR THIS PERIOD FROM CR INIT. TEMPERATURES FOR THE PERIOD
SHOULD RUN SLIGHTLY BELOW NORMAL DURING THE DAY AND NEAR NORMAL AT
NIGHT DUE TO EXPECTED CLOUD COVER AND POPS. A STRONG NORTHERN
VORTEX LOOKS TO COME SOUTH TOWARD THE CONUS SOMETIME LATE NEXT
WEEK WHICH SHOULD YIELD DRIER AND UNSEASONABLY COOL WEATHER BEHIND
ITS PASSAGE.
GOSSELIN
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 615 AM CDT FRI AUG 2 2013
A BIT OF A MESSY FORECAST. MODELS DID NOT HAVE THE MCS OVER
EASTERN KANSAS AND WESTERN MISSOURI VERY WELL FORECAST AT ALL.
THUS DO NOT HAVE A LOT OF CONFIDENCE ON THEIR SOLUTIONS FOR THE
NEXT 24 HOURS. TREND SEEMS TO BE SO DEVELOP ANOTHER MCS OVER
SOUTHWEST MO...AND PERHAPS ANOTHER TO THE NORTH FROM NORTHEAST MO
MOVING EAST INTO ILLINOIS. PLUS THERE WILL LIKELY BE SCATTERED
DEVELPMENT DUE TO OUTFLOW BOUNDARIES. SURFACE FRONT FORECAST TO
DROP INTO NORTHERN MO THIS EVENING. POSITION OF FRONT MAY CLARIFY
WHERE THE RAIN COMPLEX(ES) FORM. GIVEN THE LACK OF CLARITY WILL GO
WITH VICNINTY OR NOW...EXCEPT FOP UIN WHERE THE CHANCE FOR EVENING
TO LATE NIGHT DEVELOPMENT APPEARS TO BE A LITTLE BETTER.
SPECIFICS FOR KSTL...WILL GO WITH VICNINTY THUNDER FOR THIS
AFTERNOON AS OUTFLOWS MAY HELP TO TRIGGER SCATTERED ACTIVITY. NOT
AT ALL CERTAIN ABOUT OVERNIGHT DEVELOPMENT DUE TO THE MODELS
TRENDING TO GO NORTH AND SOUTHWEST OF STL WITH DEVELOPMENT. A LATE
NIGHT VICINITY SEEMS SUFFICIENT FOR NOW.
JPK
&&
.PRELIMINARY POINT TEMPS/POPS...
SAINT LOUIS 86 72 87 66 / 40 60 50 10
QUINCY 84 67 82 62 / 60 60 30 5
COLUMBIA 82 69 87 66 / 70 70 50 20
JEFFERSON CITY 83 71 88 67 / 70 80 50 30
SALEM 86 69 83 64 / 30 60 50 10
FARMINGTON 86 70 84 68 / 40 70 70 20
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1241 PM CDT FRI AUG 2 2013
.AVIATION...
18Z TAFS FOR KOFK...KOMA AND KLNK.
MAIN CONCERN IS POTENTIAL TSRA LATER THIS AFTN. STORM DEVELOPMENT
IS REVOLVING AROUND A SFC BNDRY ALONG THE NEB...SD BORDER WHICH IS
EXPECTED TO DRIFT SLOWLY SOUTH OVER THE NEXT SEVERAL HOURS. AREAL
COVERAGE IS SOMEWHAT IN QUESTION...BUT THINK AT LEAST REASONABLE
TO INCLUDE TEMPO GROUPS AT KOFK AND KOMA. LESS CONFIDENT ANY
CONVECTION WILL MOVE INTO KLNK...THUS LEFT DRY. OTHERWISE...VFR
THRU THE FCST PD.
DEE
PREV DISCUSSION... /ISSUED 310 AM CDT FRI AUG 2 2013/
DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
657 AM CDT FRI AUG 2 2013
.AVIATION...
12Z TAFS FOR KOFK...KOMA AND KLNK.
ANOTHER ROUND OF SHOWERS AND ISOLATED THUNDERSTORMS SPROUTED
OVERNIGHT IN SOUTH DAKOTA. THESE SHOWERS ARE SPREADING SOUTHEAST
WITH TIME. FOR NOW DID MENTION SHOWERS AT KOFK AND KOMA. COVERAGE
UNCERTAIN SO LEFT OUT THUNDER. ADDITIONAL SHOWERS AND
THUNDERSTORMS MAY DEVELOP AND AFFECT LINCOLN. CONDITIONS SHOULD
GENERALLY BE VFR...HOWEVER SOME PATCHY MVFR CIGS COULD DEVELOP AT
KOFK OR KOMA. AS TEMPERATURES WARM INTO THE 80S THIS AFTERNOON
SHOWERS AND THUNDERSTORMS SHOULD RE-DEVELOP ALTHOUGH DUE TO
COVERAGE AND TIMING UNCERTAINTIES HAVE NOT INCLUDED IN THE TAFS AT
THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 310 AM CDT FRI AUG 2 2013/
DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
ZAPOTOCNY
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
310 AM CDT FRI AUG 2 2013
.DISCUSSION...
A RELATIVELY UNSETTLED WEATHER PATTERN WILL CONTINUE OVER OUR PART
OF THE COUNTRY INTO NEXT WEEK AS WE REMAIN UNDER FAST WEST TO
NORTHWEST FLOW ALOFT BETWEEN LARGE/DEEP UPPER LOW IN CANADA AND
BROAD HIGH IN THE SOUTHERN STATES. SEVERAL IMPULSES WILL WORK
THROUGH THIS FLOW THROUGH NEXT WEEK...BRINGING OCCASIONAL
THUNDERSTORM CHANCES AS SURFACE FRONT WOBBLES NORTH/SOUTH
AHEAD/BEHIND EACH WAVE.
FOR TODAY...MOST THUNDERSTORM ACTIVITY ASSOCIATED WITH THURSDAY
AFTERNOON/EVENING CONVECTION HAS SHIFTED SOUTH OF OUR AREA. HOWEVER
STRENGTHENING LOW LEVEL JET IN CENTRAL NEBRASKA HAS FIRED ADDITIONAL
STORMS IN SOUTH CENTRAL SOUTH DAKOTA. THIS ACTIVITY WILL LIKELY
DRIFT/DEVELOP EAST AND SOUTHEAST INTO NORTHEAST NEBRASKA AS LOW
LEVEL JET BECOMES SOUTHWESTERLY WITH TIME THIS MORNING. MODELS WERE
NOT HANDLING THIS PRECIPITATION PARTICULARLY WELL...BUT A BLEND OF
RAP AND HRRR SOLUTIONS OFFERS SOME RELIABILITY. EXPECT RAIN WITH
EMBEDDED STORMS CURRENTLY IN SOUTH CENTRAL NEBRASKA TO SPREAD ACROSS
THE SOUTHWEST THIRD OF THE CWA THROUGH MID MORNING WITH A DECREASING
TREND INTO EARLY AFTERNOON. SEVERE STORMS ARE NOT ANTICIPATED AS
ATMOSPHERE WAS WORKED OVER FAIRLY WELL OVERNIGHT. ANOTHER ROUND OF
STORMS COULD THEN DEVELOP IN THE MID TO LATE AFTERNOON AS A
SHORTWAVE EJECTS FROM THE HIGH PLAINS OF WYOMING/MONTANA AND SLIDES
SOUTHEAST. STORMS WOULD MOST LIKELY FORM IN SOUTH CENTRAL SOUTH
DAKOTA OR NORTH CENTRAL NEBRASKA THEN SPREAD SOUTHEAST ACROSS THE
WESTERN CWA DURING THE LATE AFTERNOON AND EVENING. SURFACE DEW
POINTS ARE FORECAST TO APPROACH 70...HELPING TO GENERATE 3000 J/KG
OR GREATER SURFACE-BASED CAPE OVER PARTS OF THE CWA. EXACT AXIS OF
HIGHEST INSTABILITY WILL BE AFFECTED BY ONGOING ACTIVITY THIS
MORNING...BUT LOOKS LIKE IT WILL SET UP OVER THE SOUTHERN HALF OF
OUR AREA. FARTHER NORTH...FASTER MID LEVEL FLOW WILL YIELD 50KT OF
BULK SHEAR...SO ANY STORMS THAT WORK INTO NORTHEAST NEBRASKA WILL BE
POTENTIALLY SEVERE AS WELL.
CONVECTION SHOULD BE SETTLING SOUTH OF NEBRASKA AFTER MIDNIGHT AS
SHORTWAVE MOVES OFF TO THE EAST. MOST OF SATURDAY THEN LOOKS DRY
WITH FOCUS FOR STORMS IN THE HIGH PLAINS. THEN THE NEXT SHORTWAVE
SHOULD BE ROLLING INTO THE AREA SATURDAY NIGHT SETTING UP ANOTHER
ROUND OF STORMS AS LOW LEVEL JET ONCE AGAIN DRIVES CONVECTION IN
WARM ADVECTION REGIME. THIS CONVECTION WILL LIKELY LINGER INTO AT
LEAST SUNDAY MORNING BEFORE MOVING OFF TO THE SOUTHEAST.
MUCH OF THE SAME IS FORECAST FOR NEXT WEEK. MONDAY OFFERS THE BEST
CHANCE FOR A DRY FORECAST BEFORE A STRONGER SHORTWAVE PUSHES A FRONT
THROUGH OUR AREA TUESDAY...WHICH THEN LIFTS BACK NORTH ON WEDNESDAY.
WILL NOT CHANGE FORECAST MUCH FROM GOING NUMBERS TUESDAY THROUGH
THURSDAY AS TIMING SHORTWAVES THIS FAR OUT IS DIFFICULT. HOWEVER
PATTERN CERTAINLY FAVORS AT LEAST A CHANCE FOR STORMS EACH DAY.
DERGAN
&&
.AVIATION...06Z TAFS FOR KOFK...KOMA AND KLNK.
AREA OF THUNDERSTORMS HAD MOVED WELL SOUTH OF KOFK AND KOMA
WITH KLNK ON THE NORTHERN EDGE AT 06Z. EXPECT SOUTHEAST
TREND IN MOVEMENT TO CONTINUE WITH NO MENTION OF CONVECTION
IN THE TAFS. SOME POTENTIAL FOR LIGHT FOG AND POSSIBLE LIFR CIGS
FOR A TIME AROUND SUNRISE ESPECIALLY IF MORE SIGNIFICANT CLEARING
OCCURS WITH KOFK LOOKING TO HAVE THE BETTER CHANCE OF THIS
DEVELOPMENT. VFR CONDITIONS PREVAIL AFTER 17Z AS SOUTHEAST WINDS
INCREASE TO AROUND 10KTS.
FOBERT
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1229 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 300 PM CDT THU AUG 1 2013
MORNING MAP ANALYSIS INDICATES MID TO UPPER LEVEL RIDGING OVER THE
WESTERN CONUS...WITH A TROUGH OVER THE EAST. MID TO UPPER LEVEL JET
ENERGY EXTENDS FROM THE WEST-CENTRAL CONUS...NORTHEAST INTO THE
NORTHERN ROCKY MOUNTAIN RANGE...AND THEN SOUTHEAST ACROSS PORTIONS
OF THE PLAINS AND MISSISSIPPI VALLEY...AND FINALLY EAST/NORTHEAST
INTO THE EASTERN CONUS. NORTHWESTERLY MID TO UPPER LEVEL FLOW
PERSISTS OVER THE CENTRAL PLAINS AS A RESULT. A ~110KT UPPER LEVEL
JET STREAK IS ALSO NOTED EXTENDING FROM THE NORTHERN
PLAINS...SOUTHEAST INTO THE MID-MISSISSIPPI VALLEY. MID TO UPPER
LEVEL FLOW MAXES OUT AT AROUND 100KTS NEAR 200MB PER RAP ANALYSIS
AND 12Z SOUNDING DATA FROM KOAX. AT THE SURFACE A RIDGE OF HIGH
PRESSURE EXTENDS FROM THE MISSOURI RIVER VALLEY...SOUTH/SOUTHEAST
INTO PORTIONS OF THE MID-MISSISSIPPI VALLEY. LEE SIDE TROUGHING ALSO
EXTENDS FROM SOUTHEASTERN WYOMING INTO EASTERN COLORADO AND AS A
RESULT...SOUTHERLY LOW LEVEL FLOW IS INFILTRATING OUR CWA.
FOR THE REST OF THIS AFTERNOON AND EVENING...CONTINUED SOUTHERLY LOW
LEVEL FLOW...ENHANCED BY THE DEVELOPMENT OF A 25-30KT 850MB JET
STREAK...WILL PROMOTE INCREASING THERMAL ADVECTION ACROSS MUCH OF
OUR AREA. ISENTROPIC UPGLIDE AND
SATURATION...PRIMARILY ALONG THE 310-320K SURFACES...IS EXPECTED TO
PROMOTE PRECIPITATION PRODUCTION ACROSS THE AREA. INCREASED VALUES
OF LOW LEVEL MOISTURE SHOULD CONTINUE PROMOTING DECENT VALUES OF
POTENTIAL INSTABILITY...WITH THE NAM AND OPERATIONAL GFS BOTH
SUGGESTING MUCAPE VALUES NEAR 3000J/KG ACROSS MUCH OF THE AREA. IN
ADDITION TO THE POTENTIAL INSTABILITY...DEEP LAYER BULK SHEAR VALUES
ON THE ORDER OF 40-50KTS IS ALSO EXPECTED. GIVEN ALL THIS...SEVERE
WEATHER REMAINS POSSIBLE THIS AFTERNOON INTO THIS EVENING...WITH
LARGE HAIL AND STRONG THUNDERSTORM WIND GUSTS BEING THE PRIMARY
SEVERE WEATHER THREATS. IN ADDITION THE HAIL AND WIND THREAT
HOWEVER...FORECAST PROXIMITY SOUNDINGS FROM VARIOUS MODELS SUGGEST A
SIGNIFICANTLY VEERING LOW LEVEL WIND PROFILE THUS HELPING PROMOTE
SRH VALUES NEAR 200M^2/S^2 ACROSS PORTIONS OF OUR CWA. GIVEN
THIS...WILL ALSO CONTINUE THE TORNADO MENTION IN THE HWO.
GUIDANCE SUGGESTS THE AFOREMENTIONED THERMAL ADVECTION SHOULD HELP
MAINTAIN PRECIPITATION PRODUCTION ACROSS THE AREA TONIGHT...WITH
MUCH OF THIS ACTIVITY MOVING OFF TO EAST BY EARLY FRIDAY MORNING. IT
WOULD APPEAR AS THOUGH THE SEVERE WEATHER THREAT SHOULD DIMINISH
HEADING INTO THE OVERNIGHT HOURS. THAT BEING SAID...WITH A
PERSISTENT SOUTHERLY LOW LEVEL WIND FIELD...INCREASING SIGNIFICANTLY
ABOVE THE BOUNDARY LAYER PRIMARILY DUE TO A ~50KT LOW LEVEL
JET...MAY HELP PROMOTE NOCTURNAL MCS DEVELOPMENT. WILL CONTINUE THE
MENTION OF SEVERE WEATHER ACROSS THE AREA THROUGH THE OVERNIGHT
HOURS AS A RESULT...BUT THE DETAILS OF ANY POTENTIAL MCS DEVELOPMENT
WILL NOT LIKELY BECOME ANY MORE CLEAR UNTIL LATER TONIGHT.
THE PRIMARY AXIS OF THERMAL ADVECTION SHOULD DEPART THE AREA TO THE
EAST ON FRIDAY...THUS ALLOWING FOR DECREASING PRECIPITATION CHANCES.
THAT BEING SAID...MID LEVEL PERTURBATIONS MOVING OVER THE AREA WITHIN
THE MEAN FLOW SHOULD STILL PROMOTE ENOUGH OMEGA FOR FURTHER
PRECIPITATION PRODUCTION ACROSS PORTIONS OF OUR CWA STARTING FRIDAY
AFTERNOON. SHOULD THUNDERSTORM ACTIVITY BE REALIZED FRIDAY
AFTERNOON...THEN SEVERE WEATHER COULD ONCE AGAIN BE REALIZED AS
GUIDANCE SUGGESTS MUCAPE VALUES NEAR 3000J/KG WILL ACCOMPANY DEEP
LAYER BULK SHEAR VALUES OF 30-40KTS. GIVEN ALL THIS...WILL GO AHEAD
AND OUTLOOK SEVERE WEATHER FOR FRIDAY AS WELL.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 300 PM CDT THU AUG 1 2013
FORECAST CONCERNS MAINLY FOCUSED ON THUNDERSTORMS.
MODELS ARE IN GOOD AGREEMENT THAT THE NORTHWEST FLOW REGIME WILL
PERSIST THROUGH THE PERIOD. THUS...EXPECT A PERIOD OF UNSETTLED
WEATHER WITH NORMAL OR BELOW NORMAL TEMPERATURES.
AT THE SURFACE...A BROAD AREA OF LOW PRESSURE ON THE LEE SIDE OF
THE ROCKIES WILL ANCHOR A WEAK FRONTAL BOUNDARY THAT WILL
OSCILLATE FROM KS TO SD THROUGH THE PERIOD. THE LOCATION OF THIS
BOUNDARY WILL BE THE FOCUS OF AFTERNOON CONVECTIVE INITIATION. THEN
STORMS SHOULD DRIFT SOUTH AND EAST THROUGH THE EVENING HOURS AS AN
MCS. THERE WILL BE GOOD INSTABILITY AND MOISTURE AVAILABLE...SO
SEVERE STORMS CAN NOT BE RULED OUT.
ALOFT...THE NORTHWEST FLOW WILL ALLOW FREQUENT AND WEAK WAVES TO
MOVE OVER THE AREA. THIS WILL OFFER ENOUGH SUPPORT TO GET INITIATE
THE CONVECTION.
TOWARDS THE END OF THE PERIOD (THURSDAY) A STRONGER COOL FRONT IS
FORECAST TO MOVE SOUTH ACROSS THE AREA. IF THIS
OCCURS...TEMPERATURES WILL BE 10 TO 20 DEGREES BELOW NORMAL AND IT
WILL BE DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1228 CDT FRI AUG 2 2013
BRUNT OF THUNDERSTORMS HAVE SLID SOUTH OF THE TERMINAL BUT A FEW
WEAKER RETURNS TO THE NORTHWEST SO WILL INSERT VICINITY FOR A FEW
HOURS. JUST A SMALL CHANCE FOR REDEVELOPMENT FRI AFTERNOON AND
WILL LEAVE OUT MENTION FOR NOW. WINDS SHOULD SWING FROM SE TO NE
DURING THE FORECAST PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...BRYANT
LONG TERM...EDDY
AVIATION...EWALD
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1146 PM CDT THU AUG 1 2013
.AVIATION...
06Z TAFS FOR KOFK...KOMA AND KLNK.
AREA OF THUNDERSTORMS HAD MOVED WELL SOUTH OF KOFK AND KOMA
WITH KLNK ON THE NORTHERN EDGE AT 06Z. EXPECT SOUTHEAST
TREND IN MOVEMENT TO CONTINUE WITH NO MENTION OF CONVECTION
IN THE TAFS. SOME POTENTIAL FOR LIGHT FOG AND POSSIBLE LIFR CIGS
FOR A TIME AROUND SUNRISE ESPECIALLY IF MORE SIGNIFICANT CLEARING
OCCURS WITH KOFK LOOKING TO HAVE THE BETTER CHANCE OF THIS
DEVELOPMENT. VFR CONDITIONS PREVAIL AFTER 17Z AS SOUTHEAST WINDS
INCREASE TO AROUND 10KTS.
&&
.PREV DISCUSSION... /ISSUED 320 PM CDT THU AUG 1 2013/
DISCUSSION...
ACTIVE WEATHER EXPECTED THIS EVENING AS A MATURE MCS ACROSS
NORTHERN NEBRASKA SHOULD ROLL EAST SOUTHEAST. SEVERE WATCH
REMAINS IN EFFECT FOR NORTHEAST NEBRASKA AND NORTHWEST IOWA...AND
A TORNADO WATCH IN EFFECT FOR MUCH OF NORTH CENTRAL NEBRASKA. HOP
WRF AND RAP SEEM TO HAVE THE BEST HANDLE ON DEVELOPING CONVECTION...
THUS WILL HAVE HIGH POPS THIS EVENING WITH A SEVERE THREAT. HAVE
ISSUED A COUPLE OF SEVERE WARNINGS IN EXTREME NORTHEAST NEBRASKA...
BUT WE HAVEN`T BEEN ABLE TO GET ANY HAIL REPORTS BIGGER THAN
DIME TO NICKEL SIZE. EFFECTIVE SHEAR REMAINS QUITE HIGH AT 50 TO
60 KNOTS...BUT MID LEVEL LAPSE RATES ARE SLIGHTLY MARGINAL. WILL
ALSO CONTINUE TO MONITOR TRENDS AND ISSUE WARNINGS AS NECESSARY
FOR LARGE HAIL AND DAMAGING WINDS WITHIN THE STRONGEST CORES...AND
MAY HAVE TO EVENTUALLY EXTEND THE WATCH FURTHER EAST/SOUTHEAST
TOWARD THE I80 CORRIDOR IN TIME. THE BACK EDGE OF THE PRECIPITATION
WILL PROBABLY STILL BE IN THE AREA FRIDAY MORNING MOVING OUT OF
SOUTHEAST NEBRASKA AND SOUTHWEST IOWA. THE AFTERNOON MAY BE MOSTLY
DRY...ALTHOUGH THERE DOES APPEAR TO BE ANOTHER WEAK SURGE OF
MOISTURE MOVING SOUTH...WHICH COULD BRING A SLIGHT CHANCE OF
STORMS FRIDAY NIGHT.
BY SATURDAY...HIGH PRESSURE NOSING SOUTH OUT OF THE DAKOTAS SHOULD
KEEP SATURDAY DRY AND SLIGHTLY COOLER. THIS NORTHEASTERLY FLOW
BECOMES EAST SATURDAY NIGHT. AT THE SAME TIME...THERE IS ANOTHER
WAVE MOVING OUT OF THE ROCKIES...SO IT WILL BE A BATTLE OF HOW FAR
EAST THIS SYSTEM CAN GET BY DAYBREAK SUNDAY...VERSUS THE DRY
EASTERLY FLOW WITH HIGH PRESSURE ACROSS THE MID MISSISSIPPI RIVER
VALLEY. CHANCES SHOULD SPREAD ACROSS THE FORECAST AREA SUNDAY
THOUGH...BUT MAY STILL STRUGGLE TO MOVE INTO WESTERN IOWA. WAVE
COULD MOSTLY BE EAST SOUTHEAST OF THE AREA SO SHOULD BE MOSTLY DRY
SUNDAY NIGHT.
FOR THE EXTENDED FORECAST...THE REGION REMAINS IN PESKY NORTHWEST
FLOW. FORECAST CHALLENGES REMAIN TRYING TO TIME WEAK WAVES INTO
THE AREA...THUS OVERALL FORECAST CONFIDENCE REMAINS LOW. TOWARD
THE END OF THE PERIOD...ANOTHER FRONT SETTLING SOUTH COULD BRING
SOME COOLER TEMPS TO THE REGION BY THURSDAY...BUT COULD ALSO SHUNT
ANY PRECIP THREAT OUT OF THE AREA AS WELL.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
FOBERT
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
950 PM EDT SAT AUG 3 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL MOVE OVER NY AND PA TO START THE NEW WEEK.
CHILLY AIR FLOWING OVER THE WARM LAKES WILL PRODUCE A FEW
SPRINKLES OR SHOWERS OVER NORTHERN PORTIONS OF OUR REGION ON
SUNDAY. MILDER AIR AND A FEW SHOWERS ARE EXPECTED TUESDAY, AS
MOISTURE RETURNS FROM THE SOUTH.
&&
.NEAR TERM /THROUGH SUNDAY/...
945 PM UPDATE...
SHOWER ACTIVITY ALONG THE CENTRAL/NORTHERN PA FRONTAL REMNANTS IS
DIMINISHING, WHILE NEW ACTIVITY IS POPPING UP OVER NORTHERN NY
AHEAD OF APPROACHING SHORT WAVE.
MINOR CHANGES TO THE POP/TEMP GRIDS OVERNIGHT TO REFLECT OBSERVED
TRENDS. OTHERWISE, THINKING REMAINS THE SAME - APPROACHING SHORT
WAVE WILL DESTABILIZE LOWER ATMOSPHERE OVER NORTHERN NY. COOL AIR
FLOWING OVER RELATIVELY WARM LAKE WATERS WILL CAUSE LAKE EFFECT OR
ENHANCED SHOWERS AND SPRINKLES INTO SUNDAY.
PREV DISC...
RADAR WAS LARGELY FREE OF ECHOES EARLY THIS AFTERNOON EXCEPT FOR A
FEW VERY ISLD SHRA OCCASIONALLY POPPING UP HERE AND THERE BUT
BEING SHORT-LIVED. ACVTY SEEMS TO BE A TAD MORE PREVALENT IN NE
PA NR SFC FRNT WHICH EXTENDED FROM NRN CATSKILLS TO BTWN IPT AND
AVP IN NE PA IN OUR FORECAST AREA. WATER VAPOR IMAGERY SHOWS
SIGNIFICANT UPPER LEVEL WAVE MOVG ACRS NRN NEW ENGLAND AND SERN
CANADA. THIS WAVE WAS ENHANCING STRG UPR CONFLUENCE ACRS NEW
ENGLAND TO NOVA SCOTIA AND HENCE AN UPPER LEVEL JET STREAK WAS
POSITIONED IN THIS AREA. ENHANCED DVRG IN THE RR QUAD OF THE JET
WAS PROMOTING SOME LIFTING INTO NE PA AND ITS LOWER LEVEL AGEO
FORCING WAS ALSO PUSH THE FRNT SOUTHWARD. BEST SHOT OF A FEW SHRA
AND EVEN A LITTLE TSRA WILL BE MAINLY ACRS OUR FAR SE FORECAST
AREA IN THE POCONOS TO SRN CATSKILLS FOR THE REST OF THE
AFTERNOON DUE TO THIS DYNAMICAL FORCING. NORTH OF THE FRNT...THE
CUMULUS WAS BUILDING BUT NOT TO EXTENT THAT I EARLIER THHOUGHT.
THE ONLY EXCEPTION WAS OVER AREAS DIRECTLY DOWNWIND OF LAKE
ONTARIO WHERE LAKE MOISTURE WAS ENHANCING LL MOISTURE AND LEADING
TO DEEPER CUMULUS AND A LITTLE ISLD SHRA ACVTY AT TIMES. HENCE
HAVE SOME ISLD CHC OF SHRA WELL N OF THE FRNT ACRS CNTRL NY AND
NRN PA. THIS ACVTY WILL WANE SOON EXCEPT IN NC NY DOWNWIND OF LAKE
ONTARIO.
FOR TONIGHT...INITIALLY CUMULUS AND ISLD SHRA WILL FALL APART WITH
LOSS OF INSOLATION. CONTINUED LL NW FLOW AND CAA WILL CONT ACRS
THE RELATIVELY WARM WATERS OF LAKE ONTARIO. LAKE ONTARIO TEMPS
WERE RUNNING ARND 20-21C AS 850 MB TEMPS DROP TO ARND 7-8C OR SO BY
LATE TONIGHT. ADDTNLY ANOTHER SHRT WAVE WILL DROP SOUTHWARD
OVERNIGHT REACHING SOUTHEAST ONTARIO AND WESTERN QUEBEC BY 12Z.
LIFTING FROM THIS WAVE IN ASSCTN WITH LAKE MOISTURE WILL TRIGGER
SHRA AGAIN LATER TONIGHT IN NC NY...WITH NO PRECIPITATION EXPECTED
IN SC NY DOWN TO NE PA BEFORE 12Z.
THEN FOR SUNDAY...UPPER LEVEL WAVE PASSES TO THE EAST BUT IS
FOLLOWING BY AN EVEN CHILLIER SHOT OF AIR WITH 850 MB TEMPS
DROPPING TO ARND 6C WHICH IS ABT A 14-15C DIFFERENTIAL. THE FLOW
REMAINS ABT 310 OR SO WHICH WILL BRING LAKE MOISTURE DOWN INTO THE
HILLS OF NC NY AND DOWN TO SC NY AND FAR NE PA. WITH INSOLATION
AND COLD TEMPERATURES AT 850 MB I SEE ISLD TO SCT SHRA FROM NRN PA
TO SC NY AND SCT SHRA INTO NC NY DIRECTLY DOWNWIND OF LAKE
ONTARIO. THE ACVTY WILL WANE LATER IN THE DAY AS INSOLATION BREAKS
UP ANY ORGANIZED LAKE EFFECT RAINS. HAVE SLGHT CHC IN NE PA TO LO
CHC IN SC NY TO HIGH CHC IN NC NY FOR SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION SUNDAY NIGHT AND CROSS
THE REGION MONDAY AND MONDAY NIGHT WITH FAIR WEATHER. WITH LIGHT
WINDS I EXPECT PLENTY OF VALLEY FOG LATE SUNDAY NIGHT AND LATE
MONDAY NIGHT. FOR TUESDAY A WARM FRONT AND SOUTHERLY RETURN FLOW
WILL LIKELY SPREAD A FEW SHRA INTO NE PA AND C NY. THE
CMC...EURO...GFS AND NAM ALL INDICATE TO VARYING DEGREES THAT
THERE WILL BE ENUF MOISTURE ADVECTION FOR SOME PATCHY SHRA ACTVY.
I WENT SLGHT CHC FOR NOW FOR SHRA. OTHERWISE...FAIRLY QUIET ON
TUESDAY AND A LITTLE MILDER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RISING HGTS ON TUE WILL RESULT IN SOME INCRSG CLDS BUT SHWRS SHD
BE LIMITED DUE TO STUBBORN LL DRY AIR. YET ANOTHER DIGGING LOW
APCHS FOR WED AND THU AND PUSHES A SFC BNDRY THRU THE AREA. GOOD
GULF CONNECTIONS SHD LEAD TO GOOD CVRG OF SHWRS AND TRWS LATE WED
INTO THU AHD OF THE TROF. DRIER AND COOLER AIR RETURNS ON FRI BHD
THE FNT. ATTM IT LOOKS DRY BHD THE FNT BUT EVENTUALLY THE LWRG
HGTS WITH THE LRG UA LOW WILL RESULT IN MAINLY AFTN CONV.
TEMPS WILL CONT TO AVG WELL BLO SEASONAL NORMS THRU THE PD. MEX
GUID WAS RUNNING A BIT HIER THRU THE PD THAN HPC BUT SEEMED LIKE
THE COOLER EURO HAD A BETTER HANDLE ON THE UA LOW SO MORE CLOSELY
FLWD HPC GUID.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL TRACK ACROSS THE AREA LATE TONIGHT ACCOMPANIED BY
SCATTERED SHOWERS AND MVFR CONDITIONS. AREAS OF MVFR CONDITIONS
AND SCATTERED LIGHT SHOWERS WILL LINGER INTO SUNDAY AFTERNOON AT
SYR AND RME WHERE COOL AIR MOVING OVER LAKE ONTARIO WILL RESULT IN
SOME LAKE ENHANCED SHOWERS. FARTHER SOUTH ANY MVFR CONDITIONS WILL
IMPROVE TO GENERALLY VFR BY MID-AFTERNOON WITH BKN CIGS BETWEEN 3
AND 4 KFT.
WINDS WILL BE WNW AT LESS THAN 10 KTS TONIGHT THEN NORTHWEST AT 10
TO 20 KTS ON SUNDAY.
MON THRU WED...MAINLY VFR.
THU...MVFR IN SHRA AND TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJN/DJP
SHORT TERM...DJN
LONG TERM...DGM
AVIATION...DGM/MSE
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
813 PM EDT SAT AUG 3 2013
.SYNOPSIS...
ISOLATED SHOWERS WILL DIMINISH TONIGHT WITH FAIR BUT CHILLY
WEATHER EXPECTED. A COOL HIGH PRESSURE SYSTEM WILL BUILD INTO
GREAT LAKES AND OHIO VALLEY REGION SUNDAY WITH A FEW LAKE EFFECT
RAIN SHOWERS AFFECTING MAINLY CENTRAL NEW YORK. THIS HIGH PRESSURE
SYSTEM WILL BUILD FARTHER EAST AND COVER THE REGION FROM SUNDAY
NIGHT THROUGH MONDAY NIGHT WITH FAIR WEATHER DURING THE DAY AND
FAIRLY CHILLY TEMPERATURES BOTH SUNDAY NIGHT AND MONDAY NIGHT.
VALLEY FOG WILL BE PREVALENT BOTH NIGHTS. THE NEXT CHANCE FOR A
LITTLE RAIN WILL COME ON TUESDAY BUT IT WILL BE WIDELY SCATTERED.
MOST OF TUESDAY SHOULD BE FAIRLY DRY AND MILDER AS THE HIGH
PRESSURE SYSTEM MOVES OFFSHORE AND A SOUTHERLY RETURN FLOW
DEVELOPS.
&&
.NEAR TERM /THROUGH SUNDAY/...
RADAR WAS LARGELY FREE OF ECHOES EARLY THIS AFTERNOON EXCEPT FOR A
FEW VERY ISLD SHRA OCCASIONALLY POPPING UP HERE AND THERE BUT
BEING SHORT-LIVED. ACVTY SEEMS TO BE A TAD MORE PREVALENT IN NE
PA NR SFC FRNT WHICH EXTENDED FROM NRN CATSKILLS TO BTWN IPT AND
AVP IN NE PA IN OUR FORECAST AREA. WATER VAPOR IMAGERY SHOWS
SIGNIFICANT UPPER LEVEL WAVE MOVG ACRS NRN NEW ENGLAND AND SERN
CANADA. THIS WAVE WAS ENHANCING STRG UPR CONFLUENCE ACRS NEW
ENGLAND TO NOVA SCOTIA AND HENCE AN UPPER LEVEL JET STREAK WAS
POSITIONED IN THIS AREA. ENHANCED DVRG IN THE RR QUAD OF THE JET
WAS PROMOTING SOME LIFTING INTO NE PA AND ITS LOWER LEVEL AGEO
FORCING WAS ALSO PUSH THE FRNT SOUTHWARD. BEST SHOT OF A FEW SHRA
AND EVEN A LITTLE TSRA WILL BE MAINLY ACRS OUR FAR SE FORECAST
AREA IN THE POCONOS TO SRN CATSKILLS FOR THE REST OF THE
AFTERNOON DUE TO THIS DYNAMICAL FORCING. NORTH OF THE FRNT...THE
CUMULUS WAS BUILDING BUT NOT TO EXTENT THAT I EARLIER THHOUGHT.
THE ONLY EXCEPTION WAS OVER AREAS DIRECTLY DOWNWIND OF LAKE
ONTARIO WHERE LAKE MOISTURE WAS ENHANCING LL MOISTURE AND LEADING
TO DEEPER CUMULUS AND A LITTLE ISLD SHRA ACVTY AT TIMES. HENCE
HAVE SOME ISLD CHC OF SHRA WELL N OF THE FRNT ACRS CNTRL NY AND
NRN PA. THIS ACVTY WILL WANE SOON EXCEPT IN NC NY DOWNWIND OF LAKE
ONTARIO.
FOR TONIGHT...INITIALLY CUMULUS AND ISLD SHRA WILL FALL APART WITH
LOSS OF INSOLATION. CONTINUED LL NW FLOW AND CAA WILL CONT ACRS
THE RELATIVELY WARM WATERS OF LAKE ONTARIO. LAKE ONTARIO TEMPS
WERE RUNNING ARND 20-21C AS 850 MB TEMPS DROP TO ARND 7-8C OR SO BY
LATE TONIGHT. ADDTNLY ANOTHER SHRT WAVE WILL DROP SOUTHWARD
OVERNIGHT REACHING SOUTHEAST ONTARIO AND WESTERN QUEBEC BY 12Z.
LIFTING FROM THIS WAVE IN ASSCTN WITH LAKE MOISTURE WILL TRIGGER
SHRA AGAIN LATER TONIGHT IN NC NY...WITH NO PRECIPITATION EXPECTED
IN SC NY DOWN TO NE PA BEFORE 12Z.
THEN FOR SUNDAY...UPPER LEVEL WAVE PASSES TO THE EAST BUT IS
FOLLOWING BY AN EVEN CHILLIER SHOT OF AIR WITH 850 MB TEMPS
DROPPING TO ARND 6C WHICH IS ABT A 14-15C DIFFERENTIAL. THE FLOW
REMAINS ABT 310 OR SO WHICH WILL BRING LAKE MOISTURE DOWN INTO THE
HILLS OF NC NY AND DOWN TO SC NY AND FAR NE PA. WITH INSOLATION
AND COLD TEMPERATURES AT 850 MB I SEE ISLD TO SCT SHRA FROM NRN PA
TO SC NY AND SCT SHRA INTO NC NY DIRECTLY DOWNWIND OF LAKE
ONTARIO. THE ACVTY WILL WANE LATER IN THE DAY AS INSOLATION BREAKS
UP ANY ORGANIZED LAKE EFFECT RAINS. HAVE SLGHT CHC IN NE PA TO LO
CHC IN SC NY TO HIGH CHC IN NC NY FOR SUNDAY.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION SUNDAY NIGHT AND CROSS
THE REGION MONDAY AND MONDAY NIGHT WITH FAIR WEATHER. WITH LIGHT
WINDS I EXPECT PLENTY OF VALLEY FOG LATE SUNDAY NIGHT AND LATE
MONDAY NIGHT. FOR TUESDAY A WARM FRONT AND SOUTHERLY RETURN FLOW
WILL LIKELY SPREAD A FEW SHRA INTO NE PA AND C NY. THE
CMC...EURO...GFS AND NAM ALL INDICATE TO VARYING DEGREES THAT
THERE WILL BE ENUF MOISTURE ADVECTION FOR SOME PATCHY SHRA ACTVY.
I WENT SLGHT CHC FOR NOW FOR SHRA. OTHERWISE...FAIRLY QUIET ON
TUESDAY AND A LITTLE MILDER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RISING HGTS ON TUE WILL RESULT IN SOME INCRSG CLDS BUT SHWRS SHD
BE LIMITED DUE TO STUBBORN LL DRY AIR. YET ANOTHER DIGGING LOW
APCHS FOR WED AND THU AND PUSHES A SFC BNDRY THRU THE AREA. GOOD
GULF CONNECTIONS SHD LEAD TO GOOD CVRG OF SHWRS AND TRWS LATE WED
INTO THU AHD OF THE TROF. DRIER AND COOLER AIR RETURNS ON FRI BHD
THE FNT. ATTM IT LOOKS DRY BHD THE FNT BUT EVENTUALLY THE LWRG
HGTS WITH THE LRG UA LOW WILL RESULT IN MAINLY AFTN CONV.
TEMPS WILL CONT TO AVG WELL BLO SEASONAL NORMS THRU THE PD. MEX
GUID WAS RUNNING A BIT HIER THRU THE PD THAN HPC BUT SEEMED LIKE
THE COOLER EURO HAD A BETTER HANDLE ON THE UA LOW SO MORE CLOSELY
FLWD HPC GUID.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
A COLD FRONT WILL TRACK ACROSS THE AREA LATE TONIGHT ACCOMPANIED BY
SCATTERED SHOWERS AND MVFR CONDITIONS. AREAS OF MVFR CONDITIONS
AND SCATTERED LIGHT SHOWERS WILL LINGER INTO SUNDAY AFTERNOON AT
SYR AND RME WHERE COOL AIR MOVING OVER LAKE ONTARIO WILL RESULT IN
SOME LAKE ENHANCED SHOWERS. FARTHER SOUTH ANY MVFR CONDITIONS WILL
IMPROVE TO GENERALLY VFR BY MID-AFTERNOON WITH BKN CIGS BETWEEN 3
AND 4 KFT.
WINDS WILL BE WNW AT LESS THAN 10 KTS TONIGHT THEN NORTHWEST AT 10
TO 20 KTS ON SUNDAY.
MON THRU WED...MAINLY VFR.
THU...MVFR IN SHRA AND TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...DGM
AVIATION...DGM/MSE
AREA FORECAST DISCUSSION
NWS BUFFALO NY
403 PM EDT FRI AUG 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL REMAIN JUST NORTH OF THE REGION THROUGH THE
WEEKEND. A FEW SYSTEMS WILL SWING ALONG THE BOTTOM SIDE OF THE LOW
AND BRING SOME SHOWERS AND THUNDERSTORMS TO WESTERN NEW YORK...BUT
OVERALL THE WEEKEND WILL FEATURE MOSTLY DRY CONDITIONS WITH
TEMPERATURES SLIGHTLY BELOW AVERAGE.
&&
.NEAR TERM /THROUGH SATURDAY/...
THE UPPER LEVEL PATTERN FEATURES A LOW NEAR HUDSON BAY WITH A 140KT
JET OVER THE UPPER MI PENINSULA. THIS JET IS FORECAST TO PASS BY
JUST NORTH OF LAKE ONTARIO OVERNIGHT AND BRING A SHORTWAVE TROUGH
ACROSS THE REGION IN THE PROCESS. A WEAK SURFACE FRONTAL ZONE WILL
ACCOMPANY THE UPPER LEVEL FEATURES AND BRING A LIKELIHOOD OF SHOWERS
AND THUNDERSTORMS FOR MUCH OF WESTERN NY AND EVENTUALLY THE EASTERN
LAKE ONTARIO REGION TONIGHT.
MEANWHILE A THIN LAKE BREEZE CONVERGENT ZONE SOUTH OF LAKE ONTARIO
CONTINUES TO PRODUCE CONVECTION FROM NIAGARA COUNTY EAST TO METRO
ROC. EXPECT THIS TO EVOLVE INTO ITS OWN EASTWARD MOVING LINE LATER
TONIGHT...OR WEAKEN/MERGE WITH UPSTREAM CONVECTION. EITHER WAY...A
HIGH LIKELIHOOD OF SHOWERS AND THUNDERSTORMS LOOKS GOOD FOR THE
GENESEE VALLEY/FINGER LAKES REGION AT SOME POINT DURING THE
EVENING.
SUCCESSIVE RUNS OF THE HRRR AND LAST NIGHTS SSEO HAVE HANDLED
ONGOING AND UPSTREAM DAYTIME CONVECTION FAIRLY WELL AND WILL
GENERALLY USE THEM AS A GUIDE FOR THE TIMING AND PROBABILITY OF
PRECIPITATION TONIGHT TOGETHER WITH SREF DATA.
THE CURRENT CONVECTION OVER EAST CENTRAL MI SHOULD THEREFORE
CONTINUE TO EVOLVE AND MOVE SE INTO SOUTHERN ONTARIO AND THEN WEAKEN
SOME EARLY THIS EVENING BEFORE SOME REDEVELOPMENT FORMS OVERHEAD
/OVER FAR WESTERN NY/ OR JUST UPSTREAM LATER EVENING...PROBABLY
AROUND OR JUST AFTER SUNSET. THE RESULTING CONVECTION IS THEN
EXPECTED TO CONTINUE EASTWARD ACROSS WESTERN NY AND INTO THE
GENESEE VALLEY AND FINGER LAKES REGION BEFORE MIDNIGHT. EAST OF
LAKE ONTARIO...EXPECT DISORGANIZED CONVECTION FOR THE REMAINDER OF
THE AFTERNOON AND INTO THE EVENING...WITH A MORE CONSOLIDATED LINE
OF STORMS MOVING THROUGH TOWARD OR SHORTLY AFTER MIDNIGHT.
THEREFORE NEARLY ALL LOCATIONS HAVE A LIKELIHOOD OF MEASURABLE
RAIN...BUT ONLY FOR A FEW HOURS AT ANY LOCATION.
THE MAIN SURFACE FRONT SHOULD BE THROUGH THE REGION AFTER MIDNIGHT
WITH A DRY SECOND HALF OF THE NIGHT.
ON SATURDAY...A SHORTWAVE RIDGE WILL MOVE IN BEHIND THE WEAK COLD
FRONT AND SHOULD PROVIDE THE REGION WITH DRY WEATHER. DRIER AIR CAN
BE SEEN UPSTREAM OVER WI WITH STEADILY DROPPING DEWPOINTS.
FORECAST SOUNDINGS INDICATE AN INVERTED-V SOUNDING...INDICATING A
WELL MIXED YET DRY LOW AIRMASS...WITH A NEAR SATURATED LEVEL NEAR
850MB AND DRY AIR ABOVE ABOUT 600 OR 700MB. THUS AFTER A MOSTLY
CLEAR MORNING...EXPECT PLENTY OF AFTERNOON FLAT CUMULUS WITH A WEAK
CAP ABOVE ABOUT 700MB. THERE MAY BE AN ENHANCED LINE OF CUMULUS
ALONG THE LAKE ONTARIO CONVERGENT ZONE FROM ABOUT BUFFALO TO
ROCHESTER...BUT WILL NOT INCLUDE ANY PRECIPITATION AT THIS TIME WITH
THE MUCH DRIER AIRMASS IN PLACE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
SATURDAY NIGHT A SHORT WAVE TROUGH WILL BE DIGGING INTO THE BASE OF
THE PROLONGED UPPER LEVEL LOW THAT HAS REMAINED PARKED OVER AND TO
THE NORTH OF OUR AREA. THIS SHORTWAVE WILL BRING A REINFORCING SHOT
OF COOLER SUMMER-TIME AIR...ALONG WITH CHANCES FOR SHOWERS ALONG THE
SURFACE TROUGH. THIS TROUGH WILL DROP ACROSS THE NORTH COUNTRY
THROUGH THE NIGHT AND WILL CARRY CHANCE POPS HERE.
SUNDAY THIS SURFACE TROUGH WILL CONTINUE TO DROP SOUTHWARD WITH THE
BEST LIFT AND MOISTURE ALONG THE SHORTWAVE ACROSS THE FINGER LAKES
REGION. WILL CARRY HIGH CHANCE TO LOW LIKELY HERE...TRAILING TO
CHANCE POPS BACK ACROSS PORTIONS OF WESTERN NEW YORK. TOWARDS SW NEW
YORK STATE WHERE LIFT AND MOISTURE WILL BE MUCH LESS...THE REGION
WILL LIKELY REMAIN DRY. ALSO A FEW RUMBLES OF THUNDER ARE
POSSIBLE...MAINLY TO THE EAST WHERE LOW LEVEL LAPSE RATES WILL BE
STEEPEST UNDER THE COLD POOL ALOFT. WITH PARTLY TO MOSTLY CLOUDY
SKIES THROUGH THE AFTERNOON HOURS ALONG WITH 850 HPA TEMPERATURES OF
AROUND +5 TO +6C AFTERNOON TEMPERATURES WILL FEEL FALL-LIKE WITH
HIGHS ONLY IN THE 60S. THIS WILL BE ABOUT 10 DEGREES COOLER THAN
NORMAL.
SUNDAY NIGHT THIS SHORTWAVE AND MOISTURE WILL CARRY EASTWARD LEAVING
CLEARING SKIES AND LIGHT WINDS. HIGH PRESSURE WILL SETTLE TOWARDS
THE OHIO VALLEY...AND VALLEY FOG ACROSS THE SOUTHERN TIER IS LIKELY.
BY MONDAY MORNING TEMPERATURES AT 850 HPA WILL DROP TO AROUND +4
ACROSS THE NORTH COUNTRY AND +6C ACROSS THE SOUTHERN TIER. THIS WILL
LEAD TO COLD SUNDAY NIGHT LOWS WITH TEMPERATURES DROPPING BACK INTO
THE LOW 50S NEAR THE LAKES...AND LOW/MID 40S WELL INLAND ACROSS THE
SOUTHERN TIER AND NORTH COUNTRY. THESE READINGS WILL BE SOME 10
DEGREES BELOW NORMAL. HOWEVER THERE IS SOME UNCERTAINTY WITH THE
CLEARING SUNDAY NIGHT...AS THERE MAY BE SOME LAKE EFFECT
CLOUDINESS...AND LINGERING UPSLOPE LOW STRATUS WITH THE NORTHERLY
FLOW. IF THIS WERE TO OCCUR...LOWS OVERNIGHT WILL BE A FEW DEGREES
WARMER UNDER THESE CLOUDS.
MONDAY HIGH PRESSURE WILL REMAIN ACROSS THE EASTERN GREAT LAKES AND
OHIO VALLEY REGION. THIS WILL BRING FAIR WEATHER WITH PLENTY OF
SUNSHINE AND TEMPERATURES RECOVERING BACK TO NEAR SEASONAL LEVELS WITH
AFTERNOON HIGHS IN THE 70S. REMAINING DRY MONDAY NIGHT...AND
CONTINUED CHILLY WITH LOWS ABOUT 5-7 DEGREES BELOW THE NORM.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THROUGH THE LONG TERM PERIOD AN UPPER LEVEL LOW WILL REMAIN JUST TO
OUR NORTH OF EASTERN CANADA WITH SEVERAL SHORTWAVES ROTATING THROUGH
THE FEATURE. THIS LOW WILL BEGIN TO WEAKEN...IMPART DUE TO BOTH
TELECONNECTIONS OF THE PNA AND NAO BECOMING MORE NEUTRAL THROUGH THIS
TIME PERIOD. THIS WEAKENING OF THE LOW WILL ALLOW FOR SOME WARMER
AIR TO BUILD BACK NORTHWARD...THOUGH JUST SEASONABLE...AS OPPOSED TO
THE BELOW NORMAL TEMPERATURES SINCE THE LAST WEEK OF JULY.
FOR TUESDAY HIGH PRESSURE AT THE SURFACE WILL START THE DAY OVER THE
EASTERN GREAT LAKES REGION...AND SLIDE TOWARDS THE EAST COAST
THROUGH THE DAY. ALOFT A SHORTWAVE RIDGE WILL REMAIN OVER THE
EASTERN GREAT LAKES REGION AS A SHORTWAVE TROUGH SLIDES THROUGH THE
WESTERN GREAT LAKES. THIS SHOULD ALLOW FOR A DRY DAY TUESDAY WITH
CLOUDS THICKENING THROUGH THE DAY. TEMPERATURES AHEAD OF A COLD
FRONT...AND WITH THE SOUTHERLY WIND MAY CLIMB TO A FEW DEGREES ABOVE
NORMAL TUESDAY...WITH MANY AREAS INTO THE UPPER 70S...AND LOWER 80S.
TUESDAY NIGHT WILL LIKELY REMAIN DRY AS THE SHORTWAVE SLIDES TOWARDS
THE CENTRAL LAKES...BUT THE MORE LIKELY TIME PERIOD FOR SHOWERS WILL
BE WEDNESDAY TO FRIDAY TIMEFRAME. THE GFS IS STILL A LOT FASTER THAN
THE ECMWF...WITH THE NEW 12Z ECMWF NOW BRINGING THE COLD FRONT
ACROSS THE REGION ON FRIDAY NOW. WILL CONTINUE WITH A CHANCE POP
WEDNESDAY THROUGH FRIDAY TO ACCOUNT FOR THE UNCERTAINTY...THOUGH
LIKELY AT SOME POINT IN THAT TIME FRAME SHOWERS AND THUNDERSTORMS
WILL OCCUR.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
A LAKE BREEZE CONVERGENT ZONE HAS SET UP SOUTH OF LAKE
ONTARIO...WITH MOST OF THE CONVECTION CURRENTLY NORTH OF KBUF-KROC.
THIS LINE MAY MERGE OR EVOLVE LATER THIS EVENING WITH ANOTHER
SHORTWAVE TROUGH MOVING SOUTHEASTWARD INTO SOUTHERN ONTARIO THIS
EVENING. BEHIND THE SHORTWAVE...EXPECT IMPROVING CONDITIONS TOWARD
SUNRISE WITH VALLEY FOG A POSSIBILITY IN THE SOUTHERN TIER.
IN TERMS OF FLIGHT CONDITIONS...MOST TAF LOCATIONS SHOULD REMAIN VFR
THROUGH 18Z SATURDAY...ALTHOUGH ANY THUNDERSTORM MAY BRIEFLY LOWER
CONDITIONS TO MVFR. WINDS OVERALL SHOULD SLOWLY VEER FROM SW TO NW
DURING THE COURSE OF THE TAF CYCLE AND GENERALLY REMAIN UNDER 15KTS.
OUTLOOK...
SATURDAY NIGHT THROUGH SUNDAY...MAINLY VFR WITH A SMALL CHANCE OF
SHOWERS. MONDAY...VFR.
MONDAY NIGHT AND TUESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS.
WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS/THUNDERSTORMS.
&&
.MARINE...
A WEAK COLD FRONT WILL CROSS THE REGION TONIGHT WITH A LIKELIHOOD OF
SHOWERS AND THUNDERSTORMS. WINDS WILL CONTINUE TO BE OUT OF THE
SOUTHWEST WITH SMALL CRAFT ADVISORY CONDITIONS ALONG THE EASTERN
SIDES OF THE LAKES THROUGH TONIGHT. WINDS SHOULD SLOWLY VEER TO THE
WEST OR WNW ON SATURDAY WITH SLIGHTLY LOWER WIND SPEEDS.
ANOTHER SHOT OF COLD AIR ON SUNDAY WILL THEN BRING RENEWED CHANCES
FOR SCA ADVISORIES AS WINDS AND WAVES INCREASE ON BOTH
LAKES...ESPECIALLY LAKE ONTARIO. COOL AIR ALOFT WILL ALSO MAINTAIN
THE RISK OF WATERSPOUTS THROUGH THE WEEKEND...ESPECIALLY NEAR ANY
LAKE EFFECT CLOUD BANDS AND CONVERGENCE ZONES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EDT SATURDAY FOR
LOZ045.
&&
$$
SYNOPSIS...TJP/ZAFF
NEAR TERM...ZAFF
SHORT TERM...THOMAS
LONG TERM...THOMAS
AVIATION...ZAFF
MARINE...ZAFF
AREA FORECAST DISCUSSION
NWS BUFFALO NY
218 PM EDT FRI AUG 2 2013
.SYNOPSIS...
AN UPPER LEVEL LOW WILL REMAIN JUST NORTH OF THE REGION AND BRING
CHANCES FOR SHOWERS THROUGH THE WEEKEND...WITH BELOW AVERAGE
TEMPERATURES LASTING INTO AT LEAST EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
SHORTWAVE TROUGH MOVING EASTWARD ACROSS THE FINGER LAKES REGION THIS
AFTERNOON AND TAKING EARLIER CONVECTION WITH IT. STILL UNSTABLE
BEHIND THE SHORTWAVE WITH LAKE BREEZE CONVERGENCE STARTING TO SHOW
UP ALONG LAKE ONTARIO BREEZE. EXPECT RENEWED SHOWERS AND
THUNDERSTORMS ALONG THIS LINE LATER THIS AFTERNOON AND INTO THE
EARLY EVENING HOURS.
TONIGHT WILL HAVE TO DEAL WITH ANOTHER SHORTWAVE TROUGH WORKING ITS
WAY SOUTHEASTWARD THROUGH MI...AND INTO THE OH VALLEY. WESTERN NY
WILL BE ON THE NW SIDE OF THE ENERGY AND THUS THIS MAY GRAZE THE FAR
SOUTHWESTERN CORNER OF THE STATE. FOR NOW WILL FOLLOW THE SSEO AND
SUCCESSIVE RUNS OF THE HRRR WHICH BRING CONVECTION INTO MUCH OF
WESTERN NY BETWEEN ABOUT 03Z AND 06Z WITH THE PASSAGE OF A WEAK COLD
FRONT.
BEHIND THE COLD FRONT A WEAK SHORTWAVE RIDGE WILL END UP OVER
WESTERN NY FOR SATURDAY...WITH NO CONVECTION EXPECTED SAVE FOR A
SMALL BOUNDARY SOUTH OF LAKE ONTARIO. THIS TIME HOWEVER... THE
AIRMASS WILL BE DRIER COMPARED TO TODAY...WITH PRECIPITABLE WATER
DROPPING FROM OVER 1.5 INCHES THIS MORNING DOWN TO ABOUT 0.75 INCHES
BY SATURDAY. A WEAK CAP IS EXPECTED AS WELL WITH A THIN SATURATED
LAYER BETWEEN ABOUT 800 TO 600 MB.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH SUNDAY NIGHT/...
THE GENERAL PATTERN WILL CHANGE LITTLE...WITH AN UPPER LEVEL TROF
AXIS EXTENDING FROM HUDSON BAY TO NEW ENGLAND THROUGHOUT THE
PERIOD. ANOTHER SHORTWAVE WILL APPROACH SATURDAY EVENING...WITH
THIS LIKELY TO DEEPEN AND SLOW AS IT CROSSES LATE SATURDAY NIGHT
INTO SUNDAY. A CONSENSUS OF LATEST SREF/GFS/NAM/ECWMF GUIDANCE
DROPS 850 MB TEMPS TO ABOUT +5C...WHICH IS COOLER THAN PREVIOUS
MODEL CONSENSUS. THIS SHOULD GIVE SUNDAY QUITE A FALL-LIKE
FEEL...WITH COOL TEMPERATURES AND LOTS OF LAKE ENHANCED CLOUD
COVER. THE COMBINATION OF THE UPPER LEVEL SHORTWAVE AND LAKE
INDUCED CAPES OF 1000-1500 J/KG WILL RESULT IN SOME LAKE EFFECT
RAIN SHOWERS. EXPECT THESE TO BE CELLULAR IN NATURE RATHER THAN
ORGANIZED LAKE BANDS...BUT SHOULD BE FAIRLY WIDESPREAD LATE
MORNING AND EARLY AFTERNOON WITH THE PASSAGE OF THE SHORTWAVE.
COOL AIR ALOFT WILL BE FAVORABLE FOR GRAUPEL DEVELOPMENT...WHICH
WILL RESULT IN A LIMITED POTENTIAL FOR LIGHTNING...EVEN FROM LOW
TOPPED CELLS. HIGHS SHOULD BE IN THE UPPER 60S TO AROUND 70.
THE SHORTWAVE WILL GRADUALLY EXIT TO THE EAST SUNDAY NIGHT...WITH A
VERY SLOW CLEARING TREND EXPECTED AS COOL AIR ALOFT RESULTS IN LAKE
EFFECT CLOUDS. SURFACE HIGH PRESSURE IS FORECAST TO BUILD IN FROM
THE OHIO VALLEY LATE IN THE NIGHT...WITH DIMINISHING WINDS AND AT
LEAST A PARTIAL CLEARING LATE IN THE NIGHT. IT WILL BE QUITE
CHILLY...ESPECIALLY WHERE IT CLEARS OUT...WITH LOWS RANGING FROM THE
MID 40S TO THE MID 50S. BECAUSE OF THE VARIABLE CLOUD COVER...HAVE A
LOW FORECAST CONFIDENCE IN THE LOW TEMPERATURE FORECAST SUNDAY NIGHT.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
EARLY NEXT WEEK THE UPPER LEVEL TROUGH AXIS SHIFTS JUST A TAD TO THE
EAST...AND HIGH PRESSURE NEAR THE SURFACE SHOULD SLOWLY MOVE SE INTO
THE OH VALLEY AND THEN OFF THE MID ATLANTIC COAST. THIS SHOULD
ENSURE AT LEAST ONE DAY OF DRY WEATHER - MONDAY...AND PROBABLY
TUESDAY AS WELL. 00Z GUIDANCE IS IN A BIT BETTER AGREEMENT...WITH
THE GFS/ECMWF/GGEM ALL FORECASTING A FAIRLY SIGNIFICANT UPPER LEVEL
TROF PASSAGE MID-WEEK. TIMING DIFFERENCES STILL EXIST...WITH
FORECAST BLENDING THE FASTER GFS WITH THE SLOWER ECMWF...WITH THE
BEST CHANCE FOR SHOWERS/THUNDERSTORMS ON WEDNESDAY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A WEAK SHORTWAVE TROUGH IS MOVING ACROSS CENTRAL NY AND PRODUCING A
BROKEN LINE OF THUNDERSTORMS OVER THE FINGER LAKES REGION NEW INTO
OSWEGO COUNTY. LATER THIS AFTERNOON EXPECT A LAKE BREEZE CONVERGENT
ZONE TO SET UP SOUTH OF LAKE ONTARIO...WITH ADDITIONAL THUNDERSTORM
DEVELOPMENT ROUGHLY ALONG THE NYS THRUWAY WITH POSSIBLE IMPACTS TO
KBUF-KROC. THIS SHOULD DIMINISH WITH THE LOSS OF DAYTIME HEATING.
LATER THIS EVENING...PROBABLY JUST AFTER SUNSET...ANOTHER SHORTWAVE
TROUGH EVIDENT ON SATELLITE IMAGERY NEAR NORTHERN MI WILL MOVE
SE....AFFECTING PORTIONS OF WESTERN NY.
IN TERMS OF FLIGHT CONDITIONS...MOST TAF LOCATIONS SHOULD REMAIN VFR
THROUGH 18Z SATURDAY...ALTHOUGH ANY THUNDERSTORM MAY BRIEFLY LOWER
CONDITIONS TO MVFR. WINDS OVERALL SHOULD SLOWLY VEER FROM SW TO NW
DURING THE COURSE OF THE TAF CYCLE AND GENERALLY REMAIN UNDER 15KTS.
OUTLOOK...
SATURDAY NIGHT THROUGH SUNDAY...MAINLY VFR WITH A SMALL CHANCE OF
SHOWERS. MONDAY...VFR.
MONDAY NIGHT AND TUESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS.
WEDNESDAY...MVFR/VFR WITH A CHANCE OF SHOWERS/THUNDERSTORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE AGAIN TODAY...RESULTING IN MARGINAL
SMALL CRAFT ADVISORY CONDITIONS ACROSS THE EASTERN NEARSHORES OF
LAKES ERIE AND ONTARIO.
ANOTHER SHOT OF COLD AIR ON SUNDAY WILL THEN BRING RENEWED CHANCES
FOR SCA ADVISORIES AS WINDS AND WAVES INCREASE ON BOTH
LAKES...ESPECIALLY LAKE ONTARIO. COOL AIR ALOFT WILL ALSO MAINTAIN
THE RISK OF WATERSPOUTS THROUGH THE WEEKEND...ESPECIALLY NEAR ANY
LAKE EFFECT CLOUD BANDS AND CONVERGENCE ZONES.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR
LOZ045.
&&
$$
SYNOPSIS...TJP
NEAR TERM...AR/ZAFF
SHORT TERM...APFFEL
LONG TERM...APFFEL/ZAFF
AVIATION...ZAFF
MARINE...APFFEL/TJP
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1030 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT FRIDAY...FORECAST IN GOOD SHAPE AS WE HEAD INTO
THE LATE MORNING HOURS. DID ADJUST SKY COVER DOWNWARD THROUGH
EARLY TO MID AFTERNOON BASED OFF CURRENT OBSERVATIONAL DATA. ALSO
TWEAKED HOURLY TEMP DATA...WHICH PER 925 MB THERMAL PROGS AND AT
LEAST A DECENT AMOUNT OF INSOLATION TODAY SUGGEST MAX TEMPS MAY BE
A BIT HIGHER THAN EARLIER INDICATIONS. PRIOR DISCUSSION FOLLOWS.
HAVE A GREAT DAY.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...STILL DEALING WITH SOME LOWER CEILINGS AND
VISIBILITIES ACROSS THE AREA. LOOK FOR MVFR TO IFR CEILINGS AND
VISIBILITIES THROUGH 14Z BEFORE VFR CONDITIONS DEVELOP ALL AREAS.
EXPECTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING WITH MVFR CONDITIONS POSSIBLE WITH THE
PRECIPITATION...ESPECIALLY BETWEEN 18Z AND 02Z. AFTER 02Z THERE
WILL STILL BE MVFR CEILINGS LINGERING OVER THE AREA AND SCATTERED
SHOWERS WILL ALSO EXIST...HOWEVER VISIBILITIES SHOULD REMAIN IN
THE VFR CATEGORY. WINDS WILL GENERALLY BE FROM THE SOUTH AND
SOUTHWEST FROM MID-MORNING ON...BUT SPEEDS WILL GENERALLY BE UNDER
15 KNOTS.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1030 AM EDT FRIDAY...NOAA WEATHER RADIO WXM
44...BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE
OFF THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR WILL BE DOWN FOR A FEW HOURS THIS MORNING FOR TESTING.
THE RADAR SHOULD RETURN TO SERVICE BY THIS AFTERNOON.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...JMG/TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
727 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT FRIDAY...UPDATED FCST TO DECREASE POPS ACRS OUR
CWA THIS MORNING...AS CRNT RADAR SHOWS VERY LIMITED ACTIVITY.
WATER VAPOR SHOWS BEST DEEP LAYER RH HAS SHIFTED TO OUR
EAST...WHILE BEST PVS IS JUST NORTH OF OUR FA. BETTER DYNAMICS
LOCATED OVER THE NORTHERN GREAT LAKES WL IMPACT OUR REGION BY 18Z
THIS AFTN...WITH ADDITIONAL SHOWERS. HAVE CONTINUED TO MENTION CHC
POPS THIS AFTN WITH TEMPS WARMING INTO THE U60S MTNS TO NEAR 80F
WARMER VALLEY LOCATIONS.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
THROUGH 12Z SATURDAY...STILL DEALING WITH SOME LOWER CEILINGS AND
VISIBILITIES ACROSS THE AREA. LOOK FOR MVFR TO IFR CEILINGS AND
VISIBILITIES THROUGH 14Z BEFORE VFR CONDITIONS DEVELOP ALL AREAS.
EXPECTING SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS THIS
AFTERNOON AND EVENING WITH MVFR CONDITIONS POSSIBLE WITH THE
PRECIPITATION...ESPECIALLY BETWEEN 18Z AND 02Z. AFTER 02Z THERE
WILL STILL BE MVFR CEILINGS LINGERING OVER THE AREA AND SCATTERED
SHOWERS WILL ALSO EXIST...HOWEVER VISIBILITIES SHOULD REMAIN IN
THE VFR CATEGORY. WINDS WILL GENERALLY BE FROM THE SOUTH AND
SOUTHWEST FROM MID-MORNING ON...BUT SPEEDS WILL GENERALLY BE UNDER
15 KNOTS.
OUTLOOK 12Z SATURDAY THROUGH TUESDAY...
12Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
704 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 705 AM EDT FRIDAY...UPDATED FCST TO DECREASE POPS ACRS OUR
CWA THIS MORNING...AS CRNT RADAR SHOWS VERY LIMITED ACTIVITY.
WATER VAPOR SHOWS BEST DEEP LAYER RH HAS SHIFTED TO OUR
EAST...WHILE BEST PVS IS JUST NORTH OF OUR FA. BETTER DYNAMICS
LOCATED OVER THE NORTHERN GREAT LAKES WL IMPACT OUR REGION BY 18Z
THIS AFTN...WITH ADDITIONAL SHOWERS. HAVE CONTINUED TO MENTION CHC
POPS THIS AFTN WITH TEMPS WARMING INTO THE U60S MTNS TO NEAR 80F
WARMER VALLEY LOCATIONS.
FCST CHALLENGE TODAY WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/ISOLATED STORMS...FOLLOWED BY TEMPS. CRNT WATER VAPOR
SHOWS DIGGING MID/UPPER LVL TROF ACRS THE EASTERN GREAT LAKES WITH
RIBBON OF ENHANCED JET STREAM WINDS FROM THE OHIO VALLEY INTO
WESTERN NY. SATL LOOP SHOWED PLENTY OF POPCORN TYPE SHOWERS WITH
EMBEDDED LIGHTNING ACTIVITY UPSTREAM YESTERDAY AFTN ASSOCIATED
WITH 5H VORT ACRS THE NORTHERN LAKES. LARGE SCALE MODELS SHOW THIS
ELONGATED VORT LOBE IMPACTING OUR CENTRAL/NORTHERN CWA THIS
AFTN...WHILE RIBBON OF ENHANCED DEEP LAYER SHEAR ASSOCIATED WITH
MID/UPPER LVL JET MAX IS LOCATED ACRS THE MID ATLANTIC STATES.
HOWEVER...FEEL ENOUGH CLRING WL DEVELOP TO WARM SFC TEMPS INTO THE
M/U 70S...AND CREATE SFC BASED CAPE VALUES BTWN 1200 AND 1800
J/KG...ESPECIALLY AS COOLING ALOFT OCCURS. THIS INSTABILITY WL
PROMOTE STRONG ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER WITH
SOME SMALL HAIL POSSIBLE...GIVEN WBZ HGHTS BTWN 8000 AND 9000 FT
AND 500MB TEMPS BTWN -16C AND -18C. WL MENTION SMALL HAIL
POTENTIAL IN HWO. RAP 13 CONTS TO SHOW BEST PVA WITH S/W ENERGY
ARRIVING DURING MAX DAYTIME HEATING...WITH BEST 850 TO 500MB RH
ALONG THE INTERNATIONAL BORDER. FEEL THE LIMITED DEEP LAYER RH AND
PWS FALLING TO AROUND 1"...WL LIMIT AREAL COVERAGE OF
SHOWERS/STORMS THIS AFTN...WL MENTION CHC POPS WITH HIGHEST POPS
ACRS THE NORTHERN MTNS OF NY/VT. PROGGED 85H TEMPS BTWN
10-12C...WITH SOME MIXING/SUN WL SUPPORT HIGHS MID/UPPER 70S
CPV/SLV AND CT RIVER VALLEY WITH U60S TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...EXPECT SHARP CHANGES IN CONDITIONS ACROSS
THE AREA THROUGH 12Z DUE TO LOW CLOUDS AND FOG. MID AND HIGH LEVEL
CLOUDS ARE GRADUALLY SHIFTING EAST EARLY THIS MORNING AND WHEREVER
THERE HAS BEEN SOME CLEARING...LOW CLOUDS AND FOG HAVE DEVELOPED.
THUS THROUGH 12Z YOU CAN GENERALLY EXPECT VFR/MVFR CONDITIONS...BUT
PERIODS OF LIFR/VLIFR CONDITIONS. AFTER 12Z...VFR CONDITIONS
SHOULD DEVELOP ALL AREAS QUICKLY AS SOUTH TO SOUTHWEST WINDS
INCREASE AND PROVIDE ENOUGH MIXING TO GET RID OF THE LOW CLOUDS
AND FOG. AN UPPER LEVEL DISTURBANCE COMBINED WITH AN INCREASINGLY
UNSTABLE ATMOSPHERE SUGGESTS SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL DEVELOP OVER THE AREA AFTER 16Z AND CONTINUE
THROUGH THE REMAINDER OF THE PERIOD. EXPECT VFR/MVFR CONDITIONS
FROM 16Z THROUGH THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
408 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE WILL CONTINUE TO DEVELOP ACROSS OUR
REGION TODAY. THIS COLD AIR ALOFT...COMBINED WITH SOME SURFACE
HEATING WILL HELP IN THE DEVELOPMENT OF ADDITIONAL SCATTERED SHOWERS
AND THUNDERSTORMS THIS AFTERNOON...WITH SOME STORMS CONTAINING SMALL
HAIL. THE CHANCES FOR SHOWERS WILL CONTINUE ON SATURDAY WITH
TEMPERATURES DROPPING TO BELOW NORMAL VALUES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 410 AM EDT FRIDAY...FCST CHALLENGE TODAY WL BE AREAL
COVERAGE/INTENSITY OF SHOWERS/ISOLATED STORMS...FOLLOWED BY
TEMPS. CRNT WATER VAPOR SHOWS DIGGING MID/UPPER LVL TROF ACRS THE
EASTERN GREAT LAKES WITH RIBBON OF ENHANCED JET STREAM WINDS FROM
THE OHIO VALLEY INTO WESTERN NY. SATL LOOP SHOWED PLENTY OF
POPCORN TYPE SHOWERS WITH EMBEDDED LIGHTNING ACTIVITY UPSTREAM
YESTERDAY AFTN ASSOCIATED WITH 5H VORT ACRS THE NORTHERN LAKES.
LARGE SCALE MODELS SHOW THIS ELONGATED VORT LOBE IMPACTING OUR
CENTRAL/NORTHERN CWA THIS AFTN...WHILE RIBBON OF ENHANCED DEEP
LAYER SHEAR ASSOCIATED WITH MID/UPPER LVL JET MAX IS LOCATED ACRS
THE MID ATLANTIC STATES. HOWEVER...FEEL ENOUGH CLRING WL DEVELOP
TO WARM SFC TEMPS INTO THE M/U 70S...AND CREATE SFC BASED CAPE
VALUES BTWN 1200 AND 1800 J/KG...ESPECIALLY AS COOLING ALOFT
OCCURS. THIS INSTABILITY WL PROMOTE STRONG ENOUGH UPDRAFTS TO
SUPPORT MENTION OF THUNDER WITH SOME SMALL HAIL POSSIBLE...GIVEN
WBZ HGHTS BTWN 8000 AND 9000 FT AND 500MB TEMPS BTWN -16C AND
-18C. WL MENTION SMALL HAIL POTENTIAL IN HWO. RAP 13 CONTS TO SHOW
BEST PVA WITH S/W ENERGY ARRIVING DURING MAX DAYTIME
HEATING...WITH BEST 850 TO 500MB RH ALONG THE INTERNATIONAL
BORDER. FEEL THE LIMITED DEEP LAYER RH AND PWS FALLING TO AROUND
1"...WL LIMIT AREAL COVERAGE OF SHOWERS/STORMS THIS AFTN...WL
MENTION CHC POPS WITH HIGHEST POPS ACRS THE NORTHERN MTNS OF
NY/VT. PROGGED 85H TEMPS BTWN 10-12C...WITH SOME MIXING/SUN WL
SUPPORT HIGHS MID/UPPER 70S CPV/SLV AND CT RIVER VALLEY WITH U60S
TO L70S MTN/NEK.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AS OF 410 AM EDT FRIDAY...LITTLE CHANGE IN OVERALL FCSTER THINKING
WITH VERY GOOD AGREEMENT AMONG THE LARGE SCALE MODELS...WHICH
CONTS TO SUPPORT A DEEP MID/UPPER LVL TROF ACRS OUR CWA THRU THE
WEEKEND. THIS SYNOPTIC SCALE FEATURE WL RESULT IN BLW NORMAL TEMPS
AND CHCS FOR SHOWERS THRU SAT AFTN. FCST FOCUS WL BE TIMING
INDIVIDUAL S/W`S IN THE WEST TO NORTHWEST FLW ALOFT. POTENT 5H
VORT IS EXPECTED TO IMPACT OUR CWA BTWN 06Z AND 15Z FRIDAY
NIGHT/SATURDAY MORNING...WITH STRONG DYNAMICS AND SOME 850 TO
500MB RH PRESENT. GIVEN THE PROGGED LARGE SCALE ASCENT ASSOCIATED
WITH THIS FEATURE...WOULD NOT BE SURPRISED FOR A FEW ISOLATED
STORMS...ON FRIDAY NIGHT/SATURDAY MORNING. THIS ENERGY WL LIFT NE
OF OUR CWA BY 15Z SATURDAY...WITH MUCH DRIER AIR AND LARGE SCALE
SUBSIDENCE DEVELOPING. THINKING AREAL COVERAGE/INTENSITY OF
SHOWERS WL BE LIMITED ON SAT AFTN...DUE TO DRYING ALOFT AND PWS
FALLING BTWN 0.50 AND 0.75". WL MENTION SCHC VALLEYS TO CHC POPS
MTNS. SOUNDING PROFILES SHOW VERY MODEST CAPE/INSTABILITY WITH
VALUES BTWN 200-400 J/KG. FOR FRIDAY NIGHT TIME PERIOD...WL
MENTION HIGH CHC POPS WITH SOME LOW LIKELY POPS NORTHERN DACKS.
QPF WL RANGE BTWN 0.10 AND 0.25". PROGGED 85H TEMPS REMAIN BTWN
10-12C ON SAT...SUPPORTING SLIGHTLY BLW NORMAL TEMPS MAINLY 60S
MTNS TO 70S VALLEYS. ON SUNDAY...MID/UPPER LVL TROF SHARPENS ACRS
OUR FA...AS ANOTHER POTENT VORT AND SFC COLD FRNT IMPACT THE
REGION. GFS/NAM AND ECMWF SHOW BETTER MOISTURE PROFILES ACRS OUR
FA...ALONG WITH GREATER COVERAGE IN QPF. WL MENTION HIGH CHC POPS
ATTM...BUT AN INCREASE TO LIKELY POPS MAYBE NEEDED IF CRNT TRENDS
CONT. HIGHEST POPS AND QPF WL BE ACRS THE MTN AREAS...WITH
RAINFALL AMOUNTS BTWN 0.10 AND 0.25". SOUNDINGS SHOW LIMITED
INSTABILITY WITH CAPE VALUES ONLY BTWN 100 AND 300 J/KG...WL NOT
MENTION THUNDER ATTM. 85H TEMPS DROP SEVERAL DEGREES FROM SATURDAY
AND SUPPORT HIGHS U50S/L60S MTNS/NEK TO M60S TO L70S VALLEYS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 410 AM EDT FRIDAY...PRONOUNCED NORTHWEST FLOW ALOFT ON THE
BACKSIDE OF DEPARTING UPPER TROUGH WILL BRING COOLER AND DRIER
WEATHER TO THE AREA SUNDAY NIGHT INTO MONDAY. COLD AIR ADVECTION
ON MONDAY SUGGESTS HIGHS ONLY IN THE UPPER 60S TO THE MID
70S...WHICH WILL BE ABOUT 5 TO 10 DEGREES BELOW NORMAL FOR THIS
TIME OF YEAR. DRY WEATHER CONTINUES MONDAY NIGHT INTO TUESDAY AS
FLOW ALOFT REMAINS FROM THE NORTHWEST. TEMPERATURES BEGIN TO
SLOWLY MODERATE WITH HIGH TEMPERATURES 2 TO 4 DEGREES WARMER THAN
MONDAY. THE TREND TOWARD MORE NORMAL TEMPERATURES BEGINS ON
WEDNESDAY AS FLOW ALOFT BACKS TO THE WEST AND ALLOWS FOR WARM AIR
ADVECTION TO TAKE PLACE. HIGHS WILL BE IN THE 70S TO AROUND 80
BOTH WEDNESDAY AND THURSDAY. THE WESTERLY FLOW ALOFT WILL ALLOW
FOR A SERIES OF SHORTWAVE TROUGHS TO MOVE INTO THE REGION
WEDNESDAY AND THURSDAY. AS A RESULT...THE THREAT FOR SHOWERS WILL
RETURN AND WILL MENTION A CHANCE OF SHOWERS ON BOTH DAYS.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
THROUGH 06Z SATURDAY...EXPECT SHARP CHANGES IN CONDITIONS ACROSS
THE AREA THROUGH 12Z DUE TO LOW CLOUDS AND FOG. MID AND HIGH LEVEL
CLOUDS ARE GRADUALLY SHIFTING EAST EARLY THIS MORNING AND WHEREVER
THERE HAS BEEN SOME CLEARING...LOW CLOUDS AND FOG HAVE DEVELOPED.
THUS THROUGH 12Z YOU CAN GENERALLY EXPECT VFR/MVFR CONDITIONS...BUT
PERIODS OF LIFR/VLIFR CONDITIONS. AFTER 12Z...VFR CONDITIONS
SHOULD DEVELOP ALL AREAS QUICKLY AS SOUTH TO SOUTHWEST WINDS
INCREASE AND PROVIDE ENOUGH MIXING TO GET RID OF THE LOW CLOUDS
AND FOG. AN UPPER LEVEL DISTURBANCE COMBINED WITH AN INCREASINGLY
UNSTABLE ATMOSPHERE SUGGESTS SCATTERED SHOWERS AND A FEW
THUNDERSTORMS WILL DEVELOP OVER THE AREA AFTER 16Z AND CONTINUE
THROUGH THE REMAINDER OF THE PERIOD. EXPECT VFR/MVFR CONDITIONS
FROM 16Z THROUGH THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z SATURDAY THROUGH TUESDAY...
06Z SATURDAY THROUGH 06Z MONDAY...SERIES OF UPPER LEVEL
DISTURBANCES WILL BRING SHOWERS TO THE REGION AT TIMES ALONG WITH
WIDELY SCATTERED STORMS. CONDITIONS LOWERING AT TIMES TO MVFR.
06Z MONDAY THROUGH 00Z WEDNESDAY...VFR CONDITIONS WITHIN A RIDGE
OF SFC HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1100 PM EDT THURSDAY...NOAA WEATHER RADIO WXM 44...BROADCASTING
FROM THE TOP OF MOUNT ASCUTNEY VERMONT...WILL BE OFF THE AIR UNTIL
FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/RJS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1256 AM EDT FRI AUG 2 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT THEN STALL
AND DISSIPATE OVER THE AREA ON FRIDAY. HIGH PRESSURE OFFSHORE WILL
THEN DOMINATE INTO THE FIRST PART OF THE WEEKEND. ANOTHER COLD
FRONT WILL APPROACH FROM THE NORTHWEST SUNDAY AND MOVE SOUTH OF
THE AREA BY MONDAY AS HIGH PRESSURE BUILDS ACROSS THE AREA. THE
HIGH WILL DRIFT OFFSHORE TUESDAY AND WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM FRIDAY...CONVECTION ASSOCIATED WITH THE UPPER
TROUGH/SHORTWAVE MOVING THROUGH CENTRAL NC AND SURFACE OUTFLOW
BOUNDARIES HAS WEAKENED DURING THE LAST HOUR AS CINH INCREAES AND
DRIER MID LEVEL AIR MIXES IN ALOFT. THE WEAK ILL DEFINED COLD
FRONT IS STILL WELL TO THE WEST FROM JUST EAST OF THE NC MONTAINS
INTO CENTRAL VIRGINIA. WITH STILL SUFFICENT LOW LEVEL INSTABILITY
AND MOISTURE TO WORK WITH WILL FORECAST 30-40% POPS THROUGH 08Z
THEN INDICATE DIMINISHING CHANCES FOR PRECIPITATION AS LOW LEVEL
CONVERGENCE DECREASES WITH THE WEAK FRONT FPRECAST TO MOVE INTO NC
COASTAL PLAIN BY 12Z FRIDAY BEFORE DISSIPATING. CLEARING SKIES
AND WET GROUND MAY LEAD TO SOME PATCHY FOG LATE BUT WINDS MAY NOT
COMPLETLY DECOUPLE WHICH SHOULD KEEP WIDESPREAD DENSE FOG AT BAY.
LOW TEMPS WILL BE TYPICAL OF SUMMERTIME...MAINLY 70-75 COOLEST
INLAND.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM SATURDAY/...
WEATHER CONDITIONS MORE TYPICAL OF SUMMER RETURN FOR FRIDAY AS MID
LEVEL FLOW BECOMES MORE ZONAL. CUD SEE AN ISOLATED SHOWER OR
TSTORM ALONG THE SEABREEZE AND REMNANT WEAK SFC TROF OVER THE AREA
DURING THE AFTERNOON BUT MOST AREAS WILL BE DRY AND WARM. HIGHS
MAINLY IN THE UPPER 80S/NEAR 90 INLAND...MID 80S BEACHES.
&&
.LONG TERM /SATURDAY THROUGH FRIDAY/...
AS OF 3 PM THU...A BROAD UPPER TROF WILL REMAIN IN PLACE OVER THE
EASTERN US THROUGH THE MIDDLE OF NEXT WEEK FOLLOWED BY A RETURN TO
ZONAL FLOW. THIS UPPER TROF WILL ALLOW FOR AN UNSETTLED PATTERN TO
CONTINUE THROUGH MOST OF THE PERIOD. THE LONG TERM WILL START OUT
WITH THE REMNANTS OF A WEAK FRONT OVER THE MIDDLE OF THE STATE.
POPS WILL BE IN THE 20-30% RANGE WITH MOST OF THE ACTIVITY BEING
SEABREEZE-DRIVEN. ANY CONVECTION THAT DEVELOPS WILL DISSIPATE
QUICKLY SATURDAY EVENING. POPS RE-ENTER THE FORECAST AREA FROM THE
NORTH AFTER MIDNIGHT SATURDAY NIGHT AS A RATHER STRONG COLD FRONT
DROPS RAPIDLY SOUTH. THE FRONT WILL ENTER FROM THE NORTH SUNDAY
MORNING AND CONTINUE MOVING QUICKLY SOUTH DURING THE DAY. EXPECT
CONVECTION TO END IN THE FAR NORTH IN THE AFTERNOON AND THE
SOUTHERN COUNTIES BY LATE AFTERNOON. THE FRONT WILL HAVE A STRONG
PUSH BEHIND IT WITH GOOD LIFT AND CONVERGENCE ALONG AND AHEAD OF
THE BOUNDARY. A FEW STRONG STORMS COULD DEVELOP WITH STRONG GUSTY
WINDS THE MAIN THREAT. WINDEX VALUES FROM GFS/NAM/ECMWF FORECAST
SOUNDINGS AT 18Z SUNDAY ARE 45-50 KNOTS. A BRIEF PERIOD OF DRIER
AIR WILL SPREAD IN BEHIND THE FRONT SUNDAY NIGHT AND MONDAY WITH A
NORTH TO NORTHEAST WIND FLOW. THE POST FRONTAL HIGH WILL MOVE OFF
THE COAST ON TUESDAY WITH A SOUTHWEST FLOW RETURNING. THE FRONTAL
BOUNDARY WILL BE STATIONARY NOT FAR TO THE SOUTH THROUGH MOST OF
THE WEEK. THERE WILL BE A CHANCE OF SHOWERS/STORMS EACH
DAY...MAINLY THE SCATTERED AFTERNOON/EVENING VARIETY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /THROUGH 18Z FRIDAY/
AS OF 1255 AM FRIDAY...CHANCES FOR SCATTERED
SHOWERS/THUNDERSTORMS WILL BEGIN TO DIMINISH AFTER 08Z AS DRIER
AIR ALOFT AND WEAKENING CONVERGENCE OCCUR ACROSS THE AREA. MAIN
CONCERN IS POTENTIAL FOR IFR CONDITIONS IN FOG AND STRATUS DUE TO
WET SOILS AND RADIATIONAL COOLING. NOT SURE IF WINDS COMPLETELY
DECOUPLE SO THINKING STRATUS MAY BE MORE OF A CONCERN. ALTHOUGH
THERE ARE FAVORABLE HYDROLAPSES THE UPS FOG TOOL AND BUFKIT
SUPPORT LIGHT FOG AND STRATUS VS DENSE FOG. THEREFORE LEANING
TOWARD LIMITING TO MVFR CONDITIONS ALL TAF SITES EXPCEPT FOR KOAJ
WHERE WINDS MAY DECOUPLE LONGEST. ON FRIDAY EXPECTING MAINLY VFR
CONDITIONS AS CONDITIONS WILL BE LESS FAVORBALE FOR DEEP
CONVECTION AS A DRIER AIRMASS BRIEFLY MOVES OVER THE AREA.
LONG TERM /FRI NIGHT THROUGH TUE/ AS OF 3 PM
THU...SCATTERED CONVECTION POSSIBLE EACH DAY. SOUTHWEST WINDS
FRIDAY NIGHT THROUGH SUNDAY MORNING. A FRONT WILL DROP SOUTH
THROUGH THE AREA ON SUNDAY WITH WINDS SHIFTING QUICKLY FROM
SOUTHWEST TO NORTH. SCATTERED STRONG STORMS POSSIBLE ALONG AND
AHEAD OF THE FRONT WITH SURFACE WIND GUSTS AS HIGH AS 50 KNOTS.
NORTH TO NORTHEAST WIND AND DRY WEATHER FORECAST FOR SUNDAY NIGHT
INTO MONDAY. WINDS BECOME SOUTHWEST ONCE AGAIN ON TUESDAY WITH THE
CHANCE OF AFTERNOON & EVENING CONVECTION.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/
AS OF 1255 AM FRIDAY...NO CHANGES TO PREVIOUS FORECAST WITH
MARGINAL SMALL CRAFT ADVSIORY CONDITIONS OVER THE SOUTHERN AND
CENTRAL WATERS EXPECTED THROUGH EARLY FRIDAY. WINDS HAVE SHOWN AN
UPTICK OVER THE PAST COUPLE OF HOURS AND ARE BASICALLY 15 TO 20
KNOTS OVER MOST WATERS PER THE LATEST RAP WIND FORECAST. THE BUOY
30 MILES SOUTHEAST OF NEW RIVER INLET IS REPORTING 5-6 FOOT SEAS
AND WAVE MODELS HAVE BEEN CONSISTENT IN BUILDING 6+ FT SEAS IN
RESPONSE TO THE INCREASING S/SW WIND OVER CENTRAL AND SOUTHERN
WATERS. THE SMALL CRAFT ADVISORY REMAINS IN EFFECT UNTIL 6 AM
SOUTH OF OCRACOKE AND UNTIL 8 AM FROM OCRACOKE UP TO OREGON INLET.
WINDS GRADUALLY DIMINISHING AND BECOMING MORE WSW LATE TONIGHT AND
EARLY FRIDAY AS GRADIENT SLACKENS WITH SEAS LIKELY FALLING BLO 6
FT BY SUNRISE FRIDAY. SW WINDS WILL AGAIN INCREASE MODERATELY
FRIDAY AFTN IN RESPONSE TO INLAND THERMAL TROF BUT REMAINING BLO
15 KT. SEAS MAINLY 2-4 FT FRIDAY.
LONG TERM /FRI NIGHT THROUGH TUE/
AS OF 3 PM THU...SOUTHWEST FLOW WILL CONTINUE FRIDAY NIGHT INTO
SUNDAY MORNING. WINDS AND SEAS WILL REMAIN BELOW SMALL CRAFT.
WINDS NO HIGHER THAN 10-15 KNOTS AND SEAS NO HIGHER THAN 3-5
FEET. A COLD FRONT ENTERS THE REGION FROM THE NORTH AND THE
PRESSURE GRADIENT TIGHTENS SATURDAY NIGHT. WINDS WILL BE 10-15
KNOTS THROUGHOUT...EXCEPT FOR OREGON INLET TO OCRACOKE WITH 15-20
KNOTS. THE FRONT WILL DROP QUICKLY THROUGH THE MARINE AREA DURING
THE DAY SUNDAY WITH A QUICK VEERING TO NORTH AS IT PASSES. EXPECT
THIS WIND SHIFT TO OCCUR AROUND MIDDAY IN THE NORTHERN WATERS AND
LATE IN THE AFTERNOON IN THE SOUTHERN WATERS. SOME STRONG STORMS
COULD DEVELOP ALONG AND AHEAD OF THE FRONT ON SUNDAY WITH GUSTY
SURFACE WINDS UP TO 50 KNOTS. LIGHT NORTH TO NORTHEAST FLOW
FORECAST SUNDAY NIGHT INTO MONDAY WITH HIGH PRESSURE TO THE NORTH
AND A LOOSE PRESSURE GRADIENT. THE HIGH WILL MOVE OFF THE COAST
MONDAY NIGHT WITH A SOUTHERLY FLOW SETTING UP ONCE AGAIN. WINDS
AND SEAS WILL BE VERY LIGHT WITH SPEEDS 5-10 KNOTS AND SEAS 2-4
FEET.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 8 AM EDT THIS MORNING FOR AMZ152-
154.
SMALL CRAFT ADVISORY UNTIL 6 AM EDT EARLY THIS MORNING FOR
AMZ156-158.
&&
$$
SYNOPSIS...BTC
NEAR TERM...CTC/JME
SHORT TERM...BTC
LONG TERM...HSA
AVIATION...JME/HSA
MARINE...CTC/JME/HSA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
953 PM CDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 939 PM CDT SAT AUG 3 2013
LATE EVENING UPDATE FOR MINOR POP CHANGES OVERNIGHT. SEVERE
THUNDERSTORM WATCH CONTINUES UNTIL 2 AM MDT FOR SOUTHWEST
COUNTIES. LATEST TRENDS INDICATE MAIN SEVERE THREAT MAY BE
TRANSITIONING FROM LARGE HAIL TO DAMAGING WINDS AND STORMS
APPROACH THE MT/ND BORDER...NEAR BEACH AND SOUTH THROUGH
SLOPE/BOWMAN COUNTIES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD WILL BE
THUNDERSTORM CHANCES.
CURRENTLY...ALTHOUGH NOT REAL WARM...A MOIST UNSTABLE ATMOSPHERE
IS DEVELOPING ACROSS EASTERN MONTANA AND FAR WESTERN NORTH DAKOTA.
A SHORTWAVE INDICATED OVER NORTH CENTRAL MONTANA IN A PROGRESSIVE
BAND OF WESTERLIES HAS INITIATED CONVECTION WEST OF GLASGOW.
EXPECT CONVECTION TO CONTINUE TO INCREASE IN AN AREA OF STEEPENING
LAPSE RATES AND STRONG DEEP LAYER SHEAR. THE 18 UTC HRRR INDICATES
DISCRETE SUPERCELLS TRACKING ACROSS EASTERN MONTANA THIS AFTERNOON
AND EVENING...CLIPPING THE FAR SOUTHWEST LATE THIS EVENING. THE
12 UTC WRF AND HIRES-NMM/ARW ARE SIMILAR BUT MAYBE A BIT LATER AND
TRANSITION FROM DISCRETE CELLS INTO AN MCS THAT TRACKS ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE TONIGHT INTO SUNDAY MORNING.
WHATEVER EVENTUALLY PANS OUT...WILL DEFINITELY BUMP UP POPS
TONIGHT AND SUNDAY. HAVE INCLUDED A MENTION OF SEVERE ACROSS THE
SOUTHWEST THIS EVENING. AFTER MIDNIGHT...ALTHOUGH A SEVERE STORM
CANNOT BE RULED OUT...THINK WE WILL BE ON THE DOWNWARD TREND.
HIGH TEMPERATURES ON SUNDAY WILL DEPEND GREATLY ON THE ONGOING
CONVECTION THAT TRACKS ACROSS CENTRAL INTO EASTERN NORTH DAKOTA
DURING THE DAY. UTILIZED A BLEND WITH MORE WEIGHT TOWARD RAW MODEL
GUIDANCE WHICH USUALLY WORKS WELL IN A CHANGEABLE WEATHER PATTERN.
THIS RESULTS IN A NICE GRADIENT FROM UPPER 60S ACROSS THE NORTH
CENTRAL WHERE SHOWERS HANG ON INTO THE AFTERNOON...TO AROUND 80
OVER THE SOUTHWEST WHERE WE CLEAR OUT EARLY AND TEMPERATURES
REBOUND NICELY. THE WEST WILL ALSO BEGIN TO DESTABILIZE ONCE
AGAIN SUNDAY AFTERNOON...WITH A FAVORABLE SHEAR ENVIRONMENT
REMAINING OVER THE AREA. WILL NOT MENTION SEVERE WORDING AT THIS
TIME BUT WILL KEEP A CHANCE OF THUNDERSTORMS REMAINING ACROSS ALL
OF WESTERN NORTH DAKOTA SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
CHANCES FOR PRECIPITATION WILL DECREASE WEST TO EAST SUNDAY
EVENING INTO EARLY MONDAY MORNING AS A MID LEVEL SHORTWAVE TROUGH
AND AREA OF SURFACE LOW PRESSURE MOVE EAST INTO THE GREAT LAKES
REGION AND SURFACE HIGH PRESSURE BUILDS ACROSS WESTERN NORTH
DAKOTA.
WE REMAIN IN NORTHWEST FLOW ALOFT MONDAY WITH UPPER LEVEL RIDGING
ACROSS THE SOUTHERN PLAINS AND DEEP LOW PRESSURE OVER THE WESTERN
HUDSON BAY. WILL SEE INCREASING CHANCES OF SHOWERS/THUNDERSTORMS
LATER MONDAY WEST AND NORTH AND MONDAY NIGHT AREA WIDE AS THE
UPPER LOW DRIFTS SOUTHWARD ALLOWING FOR INCREASING CYCLONIC FLOW
ALOFT INTO THE NORTHERN PLAINS. MODELS ARE KEYING IN ON TWO
DISTINCT MID LEVEL IMPULSES ROTATING THROUGH THE FLOW ACROSS NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING. BEST CHANCES FOR
PRECIPITATION WILL BE ACROSS MY NORTH AND EAST WHERE BEST LOW
LEVEL FORCING IS CURRENTLY FORECAST.
BY TUESDAY AFTERNOON...THE UPPER LEVEL LOW IS FORECAST TO BE ABOUT
250-400 MILES NORTHEAST OF LAKE WINNIPEG MAINTAINING STRONG
CYCLONIC FLOW ALOFT...WHICH PERSISTS THROUGH WEDNESDAY. LINGERING
LOW LEVEL MOISTURE COUPLED WITH EMBEDDED ENERGY IN THE FLOW ALOFT
WILL MAINTAIN SOME CHANCE FOR DIURNALLY DRIVEN SHOWERS/ISOLATED
THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY. HOWEVER...LOW LEVEL
FORCING IS PROGGED WEAK SO WIDESPREAD PRECIPITATION IS NOT
EXPECTED. IN ADDITION...MUCH COOLER CANADIAN AIR WILL FILTER INTO
THE REGION TUESDAY/TUESDAY NIGHT AND WEDNESDAY (HIGHS IN THE
LOW/MID 70S AND LOWS TUESDAY NIGHT LOW 50S/UPPER 40S).
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO THURSDAY...THEN
INTO EASTERN CANADA BY SATURDAY. HIGH PRESSURE IS FORECAST TO
BUILD ACROSS THE DAKOTAS THURSDAY AND THURSDAY NIGHT...REMAINING
IN PLACE WELL INTO SATURDAY. THIS WILL LEAD TO MAINLY DRY
CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES OVER MOST OF
THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 623 PM CDT SAT AUG 3 2013
LOW CONFIDENCE IN NEAR TERM CONVECTIVE TRENDS. USED COMPROMISE OF
SHORT RANGE MODELS TO FRAME A TWO HOUR TEMPO WINDOW MOST FAVORED FOR
THUNDERSTORMS AT KISN/KMOT/KDIK TONIGHT...AND COVERED A BROADER
PERIOD WITH CB GROUPS. THUNDERSTORM CHANCES ARE LESS AT KBIS/KJMS
SO LEFT TSRA OUT OF TAFS FOR NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RK
SHORT TERM...TWH
LONG TERM...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
750 PM CDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 740 PM CDT SAT AUG 3 2013
UPDATE FOR SEVERE THUNDERSTORM WATCH...IN EFFECT FOR THE SOUTHWEST
UNTIL 2 AM MDT SUNDAY. STORMS ACROSS FAR NORTHEAST MONTANA HAVE
SHOWN A WEAKENING TREND...AND BEST INSTABILITY/SHEAR AXIS FAVORS
WEST CENTRAL/SOUTHWEST COUNTIES FOR SEVERE POTENTIAL DURING THE
LATE EVENING. VERY LARGE HAIL GREATER THAN GOLFBALL SIZE AND
ISOLATED DAMAGING WIND GUSTS WILL BE THE MAIN THREATS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD WILL BE
THUNDERSTORM CHANCES.
CURRENTLY...ALTHOUGH NOT REAL WARM...A MOIST UNSTABLE ATMOSPHERE
IS DEVELOPING ACROSS EASTERN MONTANA AND FAR WESTERN NORTH DAKOTA.
A SHORTWAVE INDICATED OVER NORTH CENTRAL MONTANA IN A PROGRESSIVE
BAND OF WESTERLIES HAS INITIATED CONVECTION WEST OF GLASGOW.
EXPECT CONVECTION TO CONTINUE TO INCREASE IN AN AREA OF STEEPENING
LAPSE RATES AND STRONG DEEP LAYER SHEAR. THE 18 UTC HRRR INDICATES
DISCRETE SUPERCELLS TRACKING ACROSS EASTERN MONTANA THIS AFTERNOON
AND EVENING...CLIPPING THE FAR SOUTHWEST LATE THIS EVENING. THE
12 UTC WRF AND HIRES-NMM/ARW ARE SIMILAR BUT MAYBE A BIT LATER AND
TRANSITION FROM DISCRETE CELLS INTO AN MCS THAT TRACKS ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE TONIGHT INTO SUNDAY MORNING.
WHATEVER EVENTUALLY PANS OUT...WILL DEFINITELY BUMP UP POPS
TONIGHT AND SUNDAY. HAVE INCLUDED A MENTION OF SEVERE ACROSS THE
SOUTHWEST THIS EVENING. AFTER MIDNIGHT...ALTHOUGH A SEVERE STORM
CANNOT BE RULED OUT...THINK WE WILL BE ON THE DOWNWARD TREND.
HIGH TEMPERATURES ON SUNDAY WILL DEPEND GREATLY ON THE ONGOING
CONVECTION THAT TRACKS ACROSS CENTRAL INTO EASTERN NORTH DAKOTA
DURING THE DAY. UTILIZED A BLEND WITH MORE WEIGHT TOWARD RAW MODEL
GUIDANCE WHICH USUALLY WORKS WELL IN A CHANGEABLE WEATHER PATTERN.
THIS RESULTS IN A NICE GRADIENT FROM UPPER 60S ACROSS THE NORTH
CENTRAL WHERE SHOWERS HANG ON INTO THE AFTERNOON...TO AROUND 80
OVER THE SOUTHWEST WHERE WE CLEAR OUT EARLY AND TEMPERATURES
REBOUND NICELY. THE WEST WILL ALSO BEGIN TO DESTABILIZE ONCE
AGAIN SUNDAY AFTERNOON...WITH A FAVORABLE SHEAR ENVIRONMENT
REMAINING OVER THE AREA. WILL NOT MENTION SEVERE WORDING AT THIS
TIME BUT WILL KEEP A CHANCE OF THUNDERSTORMS REMAINING ACROSS ALL
OF WESTERN NORTH DAKOTA SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
CHANCES FOR PRECIPITATION WILL DECREASE WEST TO EAST SUNDAY
EVENING INTO EARLY MONDAY MORNING AS A MID LEVEL SHORTWAVE TROUGH
AND AREA OF SURFACE LOW PRESSURE MOVE EAST INTO THE GREAT LAKES
REGION AND SURFACE HIGH PRESSURE BUILDS ACROSS WESTERN NORTH
DAKOTA.
WE REMAIN IN NORTHWEST FLOW ALOFT MONDAY WITH UPPER LEVEL RIDGING
ACROSS THE SOUTHERN PLAINS AND DEEP LOW PRESSURE OVER THE WESTERN
HUDSON BAY. WILL SEE INCREASING CHANCES OF SHOWERS/THUNDERSTORMS
LATER MONDAY WEST AND NORTH AND MONDAY NIGHT AREA WIDE AS THE
UPPER LOW DRIFTS SOUTHWARD ALLOWING FOR INCREASING CYCLONIC FLOW
ALOFT INTO THE NORTHERN PLAINS. MODELS ARE KEYING IN ON TWO
DISTINCT MID LEVEL IMPULSES ROTATING THROUGH THE FLOW ACROSS NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING. BEST CHANCES FOR
PRECIPITATION WILL BE ACROSS MY NORTH AND EAST WHERE BEST LOW
LEVEL FORCING IS CURRENTLY FORECAST.
BY TUESDAY AFTERNOON...THE UPPER LEVEL LOW IS FORECAST TO BE ABOUT
250-400 MILES NORTHEAST OF LAKE WINNIPEG MAINTAINING STRONG
CYCLONIC FLOW ALOFT...WHICH PERSISTS THROUGH WEDNESDAY. LINGERING
LOW LEVEL MOISTURE COUPLED WITH EMBEDDED ENERGY IN THE FLOW ALOFT
WILL MAINTAIN SOME CHANCE FOR DIURNALLY DRIVEN SHOWERS/ISOLATED
THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY. HOWEVER...LOW LEVEL
FORCING IS PROGGED WEAK SO WIDESPREAD PRECIPITATION IS NOT
EXPECTED. IN ADDITION...MUCH COOLER CANADIAN AIR WILL FILTER INTO
THE REGION TUESDAY/TUESDAY NIGHT AND WEDNESDAY (HIGHS IN THE
LOW/MID 70S AND LOWS TUESDAY NIGHT LOW 50S/UPPER 40S).
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO THURSDAY...THEN
INTO EASTERN CANADA BY SATURDAY. HIGH PRESSURE IS FORECAST TO
BUILD ACROSS THE DAKOTAS THURSDAY AND THURSDAY NIGHT...REMAINING
IN PLACE WELL INTO SATURDAY. THIS WILL LEAD TO MAINLY DRY
CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES OVER MOST OF
THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 623 PM CDT SAT AUG 3 2013
LOW CONFIDENCE IN NEAR TERM CONVECTIVE TRENDS. USED COMPROMISE OF
SHORT RANGE MODELS TO FRAME A TWO HOUR TEMPO WINDOW MOST FAVORED FOR
THUNDERSTORMS AT KISN/KMOT/KDIK TONIGHT...AND COVERED A BROADER
PERIOD WITH CB GROUPS. THUNDERSTORM CHANCES ARE LESS AT KBIS/KJMS
SO LEFT TSRA OUT OF TAFS FOR NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RK
SHORT TERM...TWH
LONG TERM...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
640 PM CDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 623 PM CDT SAT AUG 3 2013
ONLY MINOR CHANGES TO POP TRENDS TONIGHT. SHORT RANGE MODELS ARE
STILL SHOWING CONSIDERABLE DIFFERENCES IN HANDLING
EVENING/OVERNIGHT STORMS ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
LATEST THINKING IS THAT THE FAR WEST CENTRAL AND SOUTHWEST PARTS OF
THE STATE ARE MOST FAVORED FOR STRONG TO SEVERE STORMS THROUGH
LATE EVENING. CONVECTION IS EXPECTED TO SPREAD EAST
OVERNIGHT...PERHAPS WITH A CONTINUING SEVERE THREAT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD WILL BE
THUNDERSTORM CHANCES.
CURRENTLY...ALTHOUGH NOT REAL WARM...A MOIST UNSTABLE ATMOSPHERE
IS DEVELOPING ACROSS EASTERN MONTANA AND FAR WESTERN NORTH DAKOTA.
A SHORTWAVE INDICATED OVER NORTH CENTRAL MONTANA IN A PROGRESSIVE
BAND OF WESTERLIES HAS INITIATED CONVECTION WEST OF GLASGOW.
EXPECT CONVECTION TO CONTINUE TO INCREASE IN AN AREA OF STEEPENING
LAPSE RATES AND STRONG DEEP LAYER SHEAR. THE 18 UTC HRRR INDICATES
DISCRETE SUPERCELLS TRACKING ACROSS EASTERN MONTANA THIS AFTERNOON
AND EVENING...CLIPPING THE FAR SOUTHWEST LATE THIS EVENING. THE
12 UTC WRF AND HIRES-NMM/ARW ARE SIMILAR BUT MAYBE A BIT LATER AND
TRANSITION FROM DISCRETE CELLS INTO AN MCS THAT TRACKS ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE TONIGHT INTO SUNDAY MORNING.
WHATEVER EVENTUALLY PANS OUT...WILL DEFINITELY BUMP UP POPS
TONIGHT AND SUNDAY. HAVE INCLUDED A MENTION OF SEVERE ACROSS THE
SOUTHWEST THIS EVENING. AFTER MIDNIGHT...ALTHOUGH A SEVERE STORM
CANNOT BE RULED OUT...THINK WE WILL BE ON THE DOWNWARD TREND.
HIGH TEMPERATURES ON SUNDAY WILL DEPEND GREATLY ON THE ONGOING
CONVECTION THAT TRACKS ACROSS CENTRAL INTO EASTERN NORTH DAKOTA
DURING THE DAY. UTILIZED A BLEND WITH MORE WEIGHT TOWARD RAW MODEL
GUIDANCE WHICH USUALLY WORKS WELL IN A CHANGEABLE WEATHER PATTERN.
THIS RESULTS IN A NICE GRADIENT FROM UPPER 60S ACROSS THE NORTH
CENTRAL WHERE SHOWERS HANG ON INTO THE AFTERNOON...TO AROUND 80
OVER THE SOUTHWEST WHERE WE CLEAR OUT EARLY AND TEMPERATURES
REBOUND NICELY. THE WEST WILL ALSO BEGIN TO DESTABILIZE ONCE
AGAIN SUNDAY AFTERNOON...WITH A FAVORABLE SHEAR ENVIRONMENT
REMAINING OVER THE AREA. WILL NOT MENTION SEVERE WORDING AT THIS
TIME BUT WILL KEEP A CHANCE OF THUNDERSTORMS REMAINING ACROSS ALL
OF WESTERN NORTH DAKOTA SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
CHANCES FOR PRECIPITATION WILL DECREASE WEST TO EAST SUNDAY
EVENING INTO EARLY MONDAY MORNING AS A MID LEVEL SHORTWAVE TROUGH
AND AREA OF SURFACE LOW PRESSURE MOVE EAST INTO THE GREAT LAKES
REGION AND SURFACE HIGH PRESSURE BUILDS ACROSS WESTERN NORTH
DAKOTA.
WE REMAIN IN NORTHWEST FLOW ALOFT MONDAY WITH UPPER LEVEL RIDGING
ACROSS THE SOUTHERN PLAINS AND DEEP LOW PRESSURE OVER THE WESTERN
HUDSON BAY. WILL SEE INCREASING CHANCES OF SHOWERS/THUNDERSTORMS
LATER MONDAY WEST AND NORTH AND MONDAY NIGHT AREA WIDE AS THE
UPPER LOW DRIFTS SOUTHWARD ALLOWING FOR INCREASING CYCLONIC FLOW
ALOFT INTO THE NORTHERN PLAINS. MODELS ARE KEYING IN ON TWO
DISTINCT MID LEVEL IMPULSES ROTATING THROUGH THE FLOW ACROSS NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING. BEST CHANCES FOR
PRECIPITATION WILL BE ACROSS MY NORTH AND EAST WHERE BEST LOW
LEVEL FORCING IS CURRENTLY FORECAST.
BY TUESDAY AFTERNOON...THE UPPER LEVEL LOW IS FORECAST TO BE ABOUT
250-400 MILES NORTHEAST OF LAKE WINNIPEG MAINTAINING STRONG
CYCLONIC FLOW ALOFT...WHICH PERSISTS THROUGH WEDNESDAY. LINGERING
LOW LEVEL MOISTURE COUPLED WITH EMBEDDED ENERGY IN THE FLOW ALOFT
WILL MAINTAIN SOME CHANCE FOR DIURNALLY DRIVEN SHOWERS/ISOLATED
THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY. HOWEVER...LOW LEVEL
FORCING IS PROGGED WEAK SO WIDESPREAD PRECIPITATION IS NOT
EXPECTED. IN ADDITION...MUCH COOLER CANADIAN AIR WILL FILTER INTO
THE REGION TUESDAY/TUESDAY NIGHT AND WEDNESDAY (HIGHS IN THE
LOW/MID 70S AND LOWS TUESDAY NIGHT LOW 50S/UPPER 40S).
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO THURSDAY...THEN
INTO EASTERN CANADA BY SATURDAY. HIGH PRESSURE IS FORECAST TO
BUILD ACROSS THE DAKOTAS THURSDAY AND THURSDAY NIGHT...REMAINING
IN PLACE WELL INTO SATURDAY. THIS WILL LEAD TO MAINLY DRY
CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES OVER MOST OF
THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 623 PM CDT SAT AUG 3 2013
LOW CONFIDENCE IN NEAR TERM CONVECTIVE TRENDS. USED COMPROMISE OF
SHORT RANGE MODELS TO FRAME A TWO HOUR TEMPO WINDOW MOST FAVORED FOR
THUNDERSTORMS AT KISN/KMOT/KDIK TONIGHT...AND COVERED A BROADER
PERIOD WITH CB GROUPS. THUNDERSTORM CHANCES ARE LESS AT KBIS/KJMS
SO LEFT TSRA OUT OF TAFS FOR NOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RK
SHORT TERM...TWH
LONG TERM...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1247 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1247 PM CDT FRI AUG 2 2013
HIGH PRESSURE CONTINUES TO BUILD SOUTH OVER WESTERN AND CENTRAL
NORTH DAKOTA. LATEST RADAR AND SATELLITE IMAGERY SHOWS AN IMPULSE
OVER NORTH CENTRAL MONTANA WITH NUMEROUS SHOWERS PUSHING NORTHEAST
INTO FAR NORTHEAST MONTANA. ACTIVITY WEAKENS AS YOU MOVE INTO
WESTERN NORTH DAKOTA. STILL THINK WITH AFTERNOON INSTABILITY WE
WILL SEE SCATTERED SHOWERS AND PERHAPS A FEW THUNDERSTORMS BUT
CONTINUED THE TREND OF LESSENING OVERALL COVERAGE. CLOUDS
DISSIPATING BEHIND MORNING CONVECTION OVER THE SOUTHWEST HAS
ALLOWED TEMPERATURES TO RISE CLOSE TO FORECAST HIGHS SO BUMPED UP
TEMPERATURES JUST A BIT.
UPDATE ISSUED AT 1014 AM CDT FRI AUG 2 2013
HIGH PRESSURE WILL CONTINUE TO BUILD SOUTH FROM CANADA TODAY.
UPPER LEVEL IMPULSES ROTATING AROUND NORTHWEST U.S. UPPER LOW WILL
KEEP PRECIPITATION CHANCES OVER THE WEST TODAY...BUT WITH SURFACE
HIGH PRESSURE BUILDING SOUTH...PRECIPITATION WILL HAVE A HARD TIME
MAKING IT INTO CENTRAL NORTH DAKOTA...ESPECIALLY THE NORTH
CENTRAL. HAVE UPDATED POPS TO LIMIT PRECIPITATION CHANCES EAST OF
THE HIGHWAY 83 CORRIDOR. TEMPERATURES LOOK IN LINE BUT WILL TAKE A
CLOSER LOOK AROUND MIDDAY.
UPDATE ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTH CENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTH CENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1247 PM CDT FRI AUG 2 2013
AT 1 PM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER LEVEL
SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WILL KEEP A MENTION OF
THUNDER AT KDIK TODAY AND SHOWERS AT KISN. WILL NOT MENTION ANY
PRECIPITATION AT KMOT...KBIS AND KJMS. HIGH PRESSURE WILL BUILD
OVER THE AREA TONIGHT ENDING THE THREAT OF ANY SHOWERS IN THE WEST
AS WELL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1013 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1014 AM CDT FRI AUG 2 2013
HIGH PRESSURE WILL CONTINUE TO BUILD SOUTH FROM CANADA TODAY.
UPPER LEVEL IMPULSES ROTATING AROUND NORTHWEST U.S. UPPER LOW WILL
KEEP PRECIPITATION CHANCES OVER THE WEST TODAY...BUT WITH SURFACE
HIGH PRESSURE BUILDING SOUTH...PRECIPITATION WILL HAVE A HARD TIME
MAKING IT INTO CENTRAL NORTH DAKOTA...ESPECIALLY THE NORTH
CENTRAL. HAVE UPDATED POPS TO LIMIT PRECIPITATION CHANCES EAST OF
THE HIGHWAY 83 CORRIDOR. TEMPERATURES LOOK IN LINE BUT WILL TAKE A
CLOSER LOOK AROUND MIDDAY.
UPDATE ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1014 AM CDT FRI AUG 2 2013
AT 10 AM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER LEVEL
SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN NORTH DAKOTA. WILL KEEP A MENTION OF
THUNDER AT KDIK TODAY AND SHOWERS AT KISN. WILL NOT MENTION ANY
PRECIPITATION AT KMOT...KBIS AND KJMS. HIGH PRESSURE WILL BUILD
OVER THE AREA TONIGHT ENDING THE THREAT OF ANY SHOWERS IN THE WEST
AS WELL.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...TM
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
629 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 629 AM CDT FRI AUG 2 2013
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ADJUSTED
THE HOURLY SENSIBLE WEATHER GRIDS BASED ON CURRENT OBS/TRENDS.
OTHERWISE...THE CURRENT FORECAST IS ON TRACK. THE UPDATED GRIDDED
AND TEXT PRODUCTS HAVE BEEN SENT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 629 AM CDT FRI AUG 2 2013
AT 6 AM CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL/EASTERN NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER
LEVEL SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
EASTERN MONTANA AND WESTERN SOUTH DAKOTA. MORE SHOWERS AND
THUNDERSTORMS EXPECTED TO MOVE INTO SOUTHWESTERN NORTH DAKOTA AFT
12Z. THE THREAT TO KDIK LOOKS TO LINGER FOR MUCH OF THE DAY WITH
INSTABILITY REMAINING FOR MUCH OF THE DAYTIME HOURS AS UPPER LEVEL
IMPULSES SLOWLY MOVE EAST ACROSS THE STATE. THE FARTHER EAST THE
UPPER IMPULSES GO IN NORTH DAKOTA...THE MORE STABLE THE
ATMOSPHERE...THUS DID NOT INCLUDE ANY MENTION OF SHOWERS OR THUNDER
AT KMOT OR KJMS. DID BRING MENTION OF SHOWERS AT KISN AT 15Z AND AT
KBIS AT 18Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...JV
LONG TERM...TM
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
320 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 320 AM CDT FRI AUG 2 2013
MAIN CONCERNS IN THE SHORT TERM WILL BE EXTENT/PLACEMENT OF SHOWERS
AND THUNDERSTORMS...AS FORECAST MODELS DIFFER ON HOW PRECIPITATION
FIELD WILL PLAY OUT.
CURRENTLY...SURFACE HIGH PRESSURE WAS CENTERED OVER NORTHERN
SASKATCHEWAN WITH THE RIDGE AXIS EXTENDING SOUTHEASTWARD ACROSS
NORTH CENTRAL AND EASTERN NORTH DAKOTA. MEANWHILE LOW PRESSURE WAS
CENTERED OVER WYOMING. AT UPPER LEVELS...A LOW/TROUGH WAS OVER THE
ROCKIES NEAR IDAHO/WESTERN MONTANA WITH SHORTWAVE ENERGY MOVING
THROUGH THE SOUTHWEST FLOW ALOFT OVER CENTRAL/EASTERN MONTANA. A
CLUSTER OF THUNDERSTORMS OVER SOUTHEASTERN MONTANA MOVED INTO
NORTHWESTERN SOUTH DAKOTA AND SOUTHWESTERN NORTH DAKOTA...ASSOCIATED
WITH THE UPPER LEVEL ENERGY IMPULSES. AS THE CONVECTION MOVED
EASTWARD IT ENTERED A MORE STABLE ENVIRONMENT OVER NORTH
DAKOTA...WHERE EFFECTIVE BULK SHEAR WAS LOW AND MOST UNSTABLE CAPE
WAS MINIMAL. THOUGH SHOWERS WERE OCCURRING IN SOUTHWESTERN NORTH
DAKOTA - LIGHTNING ACTIVITY HAD DECREASED GREATLY.
THE SREF SEEMS TO HAVE BEST CAPTURED CURRENT EXTENT OF SHOWERS OVER
THE DAKOTAS. THIS MODEL DEPICTS PRECIPITATION AREA EXPANDING
NORTHWARD AND EASTWARD INTO NORTH DAKOTA...SPREADING AS FAR AS MINOT
AND JAMESTOWN. HOWEVER THIS MODEL IS BULLISH REGARDING THE STRENGTH
OF THE UPPER LEVEL SHORTWAVE IMPULSES OVERCOMING THE LIMITING
FACTORS OF THE UPPER LEVEL RIDGE AND LACK OF ROBUST LOW LEVEL
MOISTURE. THE NAM AND GFS KEEP THE AREA OF PRECIPITATION MORE
CONFINED TO THE SOUTHWEST AND FAR SOUTH CENTRAL...MAINLY SOUTH OF
WILLISTON AND BISMARCK. THE RUC DEPICTS PRECIPITATION REMAINING WEST
AND SOUTH OF THE STATE UNTIL THIS AFTERNOON.
THE UPPER LEVEL SHORTWAVE ENERGY IS MOVING TOWARDS NORTH DAKOTA IN
SOUTHWEST FLOW ALOFT...EMERGING FROM THE AFOREMENTIONED ROCKIES
LOW/TROUGH...AND MOVING INTO THE DOWNSTREAM UPPER RIDGE OVER THE
WESTERN DAKOTAS. A STRONG HUDSON BAY LOW IS EXPECTED TO REMAIN
FAIRLY STATIONARY...KEEPING THE UPPER RIDGE IN PLACE. ALSO A DRY
SURFACE HIGH OVER SOUTH CENTRAL CANADA AND EXTENDING INTO THE
EASTERN DAKOTAS AND MINNESOTA WILL KEEP SURFACE DEWPOINTS IN THE
LOWER 50S AND LIMITING THE AVAILABLE LOW LEVEL MOISTURE.
THUS WILL KEEP HIGHER CHANCES IN THE FAR SOUTHWEST TODAY AND LESSER
CHANCES NORTHEASTWARD. SOME AFTERNOON HEATING MAY INCREASE THE
OVERALL INSTABILITY ACROSS THE REGION...BUT NO SEVERE STORMS ARE
ANTICIPATED IN NORTH DAKOTA. WILL KEEP SOME CHANCES OF
SHOWERS/THUNDER FOR TONIGHT AS WELL...BUT THE UPPER LEVEL RIDGE
BUILDS DURING THE NIGHT AND LESSEN THE CHANCES FOR PRECIPITATION.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 AM CDT FRI AUG 2 2013
VERY WEAK MID-LEVEL RIDGING NUDGING INTO THE NORTHERN PLAINS IS
PROGGED TO KEEP MOST OF THE REGION DRY SATURDAY. AN APPROACHING
SHORTWAVE WARRANTS MAINTAINING SLIGHT CHANCE POPS IN THE EXTREME
WEST SATURDAY.
THE AFOREMENTIONED SHORTWAVE IS FORECAST TO PUSH ACROSS THE REGION
SATURDAY NIGHT INTO SUNDAY. MAINTAINED HIGH-END CHANCE POPS FOR THIS
PERIOD AS UPPER FORCING APPEARS SUFFICIENT FOR CONVECTIVE
DEVELOPMENT. BOTH THE 00Z GFS/ECWMF PROG INCREASING MUCAPE VALUES
OVER SOUTHWESTERN AND SOUTHCENTRAL NORTH DAKOTA SUNDAY AFTERNOON.
HOWEVER...THE GREATEST MUCAPE VALUES (SOUTHWEST/SOUTHCENTRAL) ARE
DISPLACED FROM THE BEST UPPER LEVEL FORCING (EAST). WILL THEREFORE
KEEP SEVERE MENTION OUT OF THE ZONES AND HWO FOR NOW...BUT WILL
CONTINUE TO MONITOR FUTURE RUNS.
THE PERSISTENT NORTHWESTERLY FLOW ALOFT WILL MAINTAIN SLIGHT CHANCES
FOR PRECIP DAILY THROUGH THE END OF THE PERIOD. THE 00Z GFS/ECMWF
CONTINUE TO DEPICT AN ANOMALOUSLY DEEP UPPER LEVEL LOW OVER HUDSON
BAY MONDAY DROPPING SOUTH ACROSS SOUTH CANADA AND POSSIBLY INTO THE
FAR NORTH CENTRAL CONUS NEXT WEDNESDAY THROUGH FRIDAY. IF THESE
SOLUTIONS VERIFY...THIS COULD RESULT IN SIGNIFICANTLY BELOW NORMAL
TEMPERATURES DURING THE LATTER HALF OF NEXT WEEK. THE RAW GFS/ECMWF
MODEL SOLUTIONS PAINT HIGHS IN THE MID 60S (HIGHS IN THE MID 80S ARE
NORMAL FOR EARLY AUGUST) BY THURSDAY AUGUST 8. FOR NOW WILL CONTINUE
TO GO WITH A CONSERVATIVE BLENDED APPROACH AND FORECAST HIGHS IN THE
MID 70S FOR DAY 7 DUE TO THE UNCERTAINTY WITH FORECASTING OUT THAT
FAR IN ADVANCE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1227 AM CDT FRI AUG 2 2013
AT MIDNIGHT CDT...SURFACE HIGH PRESSURE RIDGE AXIS EXTENDED OVER
CENTRAL/EASTERN NORTH DAKOTA WITH LOW PRESSURE IN WYOMING. AN UPPER
LEVEL SHORTWAVE WILL BE THE FOCUS OF SHOWERS AND THUNDERSTORMS OVER
SOUTHEASTERN MONTANA MOVING INTO SOUTHWESTERN NORTH DAKOTA AFT 06Z.
THE THREAT TO KDIK LOOKS TO BE AROUND 09Z WITH INSTABILITY REMAINING
FOR MUCH OF THE DAYTIME HOURS AS UPPER LEVEL IMPULSES SLOWLY MOVE
EAST ACROSS THE STATE. THE FARTHER EAST THE UPPER IMPULSES GO IN
NORTH DAKOTA...THE MORE STABLE THE ATMOSPHERE...THUS DID NOT INCLUDE
ANY MENTION OF SHOWERS OR THUNDER AT KMOT OR KJMS. DID BRING MENTION
OF SHOWERS AT KISN AT 12Z AND AT KBIS AT 14Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...JV
LONG TERM...TM
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
1031 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE PASSES TODAY. ANOTHER COLD FRONT MOVES SOUTHEAST AND
PASSES THROUGH SATURDAY NIGHT. HIGH PRESSURE BUILDS BACK ON SUNDAY
WITH DRIER AIR INTO MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
1030 AM UPDATE....
NO CHANGES TO FCST NEEDED THIS MORNING. COMPLEX UPSTREAM ACROSS N
IND SHOULD CONT TO WEAKEN AS IT DROPS SE THIS AFTN. KEPT SE OH POP
FREE FOR AFTN. THINK ANY SHRA WILL HOLD OFF UNTIL THIS EVE.
PREVIOUS DISCUSSION BELOW...
VORT MAX CURRENTLY MOVING THROUGH PA PROVIDING JUST AN ISOLATED
SHOWER RIGHT ALONG NORTHERN CWA BORDER. OTHERWISE...SURFACE HIGH
PRESSURE WILL BE IN CONTROL TODAY. DESPITE VERY LIMITED MID LEVEL
MOISTURE...EXPECT AT LEAST A FEW CUMULUS CLOUDS DRIFTING AROUND
TODAY...WITH CIRRUS DECK INCREASING FROM WEST TO EAST THIS
AFTERNOON IN ADVANCE OF THE NEXT SYSTEM...AN APPROACHING COLD
FRONT AND UPPER LEVEL SHORT WAVE. HAVE POPS ENTERING FROM NW AFTER
00Z TONIGHT...WITH COLD FRONT REMAINING NORTH THROUGH THE ENTIRE
NEAR TERM PERIOD. LATEST NAM/GFS/ECMWF KEEP MOST OF THE ACTIVITY
NORTH OF CWA THROUGH THIS NEAR TERM...SO KEEP CHANCE POPS LIMITED
TO NORTHERN TIER OF COUNTIES...WITH SLIGHT CHANCE A BIT FARTHER
SOUTH. 06Z RAP HINTS AT A CONVECTIVE COMPLEX DEVELOPING OVER NW
OHIO THIS AFTERNOON...AND STEERING FLOW WOULD BRING THIS INTO
NORTHERN WV AS WELL. ONLY MINIMAL CHANGES MADE TO TEMPS...WITH
HIGHS AND LOWS NEAR TO JUST BELOW NORMAL.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY/...
00Z GFS CONTINUES TO SHOW VERY LITTLE INSTABILITY ON SATURDAY AHEAD
OF THE FRONT. LEANING MORE TOWARD THE 00Z NAM...THAT SHOWS A BIT
MORE INSTABILITY BUT STILL HAS A WARM LAYER AROUND 12 TO 15 THSD
FT. YET...THE NAM SEEM TO UNDERDO THE CONVECTIVE PCPN.
OF COURSE...THE MOST INSTABILITY ON SATURDAY WILL REMAIN TO OUR
SOUTHWEST...TOWARD WESTERN KENTUCKY...WESTERN TENNESSEE...ARKANSAS
VICINITY.
THE PRECIPITABLE WATER DOES PEAK AROUND 1.6 TO 1.8 AHEAD OF THE
FRONT IN OUR VICINITY. STILL MAY HAVE TO WATCH SOME EAST TO WEST
TRAINING...BUT WITH 25 TO 30 KNOT STEERING FLOW...WILL NOT INSERT A
WATER HAZARD INTO THE HAZARDOUS WEATHER POTENTIAL AS OF NOW. WILL
EVALUATE AGAIN TODAY.
BASING FORECAST ON FRONT NEAR MGW TO PKB TO ILN AROUND 03Z
SUNDAY...THEN REACHING SOUTH OF EKN AND CRW BY 09Z AND NR BLF AND SW
VA BY 12Z SUNDAY.
YET...STILL TOUGH TO FIGURE HOW QUICKLY TO INCREASE POPS DURING THE
DAY ON SATURDAY FURTHER SOUTH...AWAY FRONT THE FRONT...IN THE
HTS-CRW-BKW REGION. THIS ALSO CAUSES CONFIDENCE TO DROP IN
PREDICTING MAXIMUM TEMPERATURES SATURDAY AFTERNOON.
AHEAD OF THE FRONT...WILL KEEP OUR MAX POP AROUND 60 PERCENT
DROPPING DOWN INTO CENTRAL WV 00Z TO 06Z SUNDAY...BUT WILL NOT
DROP THESE LIKELY POPS FURTHER SOUTH...INTO EXTREME SOUTHERN WEST
VIRGINIA DURING THE PREDAWN HOURS. EXCEPT FOR THE FRONT...NOT MUCH
SUPPORT THAT FAR SOUTH.
MEANWHILE...NORTH OF THE FRONT...WAS FASTER LOWERING POPS 06Z TO 12Z
SUNDAY.
THINKING LINGERING OVERCAST AND A FEW SHOWERS POSSIBLE SUNDAY
MORNING IN OUR SOUTH. OTHERWISE DRIER AIR ADVECTS SOUTH DURING THE
DAY.
COOLER SUNDAY NIGHT. FIGURING ON SOME LATE NIGHT FOG MAINLY EKN-CRW
ON SOUTH.
&&
.LONG TERM /MONDAY NIGHT THROUGH THURSDAY/...
BROAD TROUGHING OVER THE EASTERN HALF OF THE US FROM A LARGE UPPER
LOW IN CANADA WILL KEEP TEMPERATURES A BIT BELOW NORMAL WITH DRY
CONDITIONS ON MONDAY. MOISTURE WILL BEGIN INCREASING AGAIN THROUGH
THE DAY TUESDAY WITH ISOLATED SHOWERS OR THUNDERSTORMS POSSIBLE
MAINLY IN THE MOUNTAINS. PRECIPITATION CHANCES WILL INCREASE THROUGH
MID WEEK WITH SCATTERED SHOWERS OR THUNDERSTORMS MOVING THROUGH AT
TIMES BUT HEAVIER PRECIPITATION POTENTIAL WILL REMAIN WELL SOUTH OF
THE AREA.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FOG HAS BEEN BOUNCING AROUND SOME THIS MORNING...BUT ALL SITES
SHOULD RETURN TO VFR BY 13Z. SOME SCATTERED MID-LEVEL CUMULUS
AROUND DURING THE AFTERNOON TODAY. CIRRUS WILL ALSO BEGIN
STREAMING IN FROM THE WEST THIS AFTERNOON IN ADVANCE OF THE NEXT
SYSTEM. CALM WINDS EARLY THIS MORNING WILL GIVE WAY TO LIGHT
WESTERLY FLOW THIS AFTERNOON. TONIGHT...THICKENING CLOUDS AND SOME
REMAINING FLOW SHOULD KEEP MOST FOG AT BAY. BEST CHANCE WOULD BE
TYPICAL VALLEYS IN THE MOUNTAINS...WHERE CLOUDS WILL REMAIN
THINNER THE LONGEST. EVEN THERE DO NOT THINK DENSE FOG WILL FORM
AND KEPT AT MVFR. THINK ANY PRECIP IMPACTS WILL HOLD OFF UNTIL
DAYTIME SATURDAY.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z SATURDAY...
FORECAST CONFIDENCE: MEDIUM TO HIGH.
ALTERNATE SCENARIOS: DEVELOPMENT OF FOG TONIGHT MAY VARY.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 14 15 16 17 18 19 20 21 22 23 00 01
EDT 1HRLY 10 11 12 13 14 15 16 17 18 19 20 21
CRW CONSISTENCY L H H H H H H H H H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY H H H H H H H H H H H H
EKN CONSISTENCY L H H H H H H H H H H H
PKB CONSISTENCY L H H H H H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z SATURDAY...
IFR POSSIBLE IN SHOWERS AND THUNDERSTORMS SATURDAY AND SATURDAY
NIGHT.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/MZ
NEAR TERM...MZ/30
SHORT TERM...KTB
LONG TERM...JR
AVIATION...MZ
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
950 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO ADJUST THE CLOUD COVER AND ADD A CHANCE OF SHOWERS TO
NORTHWEST OHIO FOR THIS MORNING. THE SHOWERS OVER EXTREME
NORTHWEST OHIO SHOULD DISSIPATE WITH SO MUCH DRY AIR OVER THE
REGION. STILL A QUESTION HOW QUICKLY THE SHOWERS AND THUNDERSTORMS
WILL DEVELOP THIS AFTERNOON. MANY OF THE MODELS INCLUDING THE HRRR
ARE SLOW. ALSO SOME CONCERN IF THEY COULD BE STRONG TO POSSIBLY
SEVERE. SPC HAS THE AREA IN SEE TEXT AND THIS IS REASONABLE WITH
THE 0-1KM SHEAR INCREASING THIS EVENING. SOME QUESTION HOW HIGH
THE CAPE WILL BE WITH A FAIR AMOUNT OF CLOUDS AROUND. THE STORMS
SHOULD BE MOVING...HOWEVER...SOME MINOR FLOODING OR PONDING CAN
OCCUR. WILL MENTION A THREAT IN THE HAZARDOUS WEATHER OUTLOOK FOR
LATE THIS AFTERNOON AND EVENING.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
SHOWERS HAVE BEEN EXPANDING ON REGIONAL RADARS ACROSS SW MICHIGAN
AND NW INDIANA. THESE WILL APPROACH TOL/FDY LATER THIS MORNING
ALTHOUGH EXPECT A GENERAL WEAKENING TREND AS THEY TRY TO PUSH EAST
INTO THE RIDGE. DID NOT INCLUDE ANY THUNDER THIS MORNING BUT CAN
NOT ENTIRELY RULE IT OUT.
DEEPER MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE LATER THIS AFTERNOON INTO TONIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INCLUDED TEMPO/PROB GROUP FOR MOST
LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER
WIND GUSTS WITH CONDITIONS DROPPING TO MVFR/IFR IN THE HEAVIER SHOWERS
AT TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS
A 35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...KIELTYKA/TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
745 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...FORECAST ON TRACK. MADE ONLY MINOR UPDATES TO SKY GRIDS
BASED ON SATELLITE TRENDS.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHOWERS HAVE BEEN EXPANDING ON REGIONAL RADARS ACROSS SW MICHIGAN
AND NW INDIANA. THESE WILL APPROACH TOL/FDY LATER THIS MORNING
ALTHOUGH EXPECT A GENERL WEAKENING TREND AS THEY TRY TO PUSH EAST
INTO THE RIDGE. DID NOT INCLUDE ANY THUNDER THIS MORNING BUT CAN
NOT ENTIRELY RULE IT OUT.
DEEPER MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE LATER THIS AFTERNOON INTO TONIGHT AHEAD OF AN APPROACHING
COLD FRONT. HAVE INCLUDED TEMPO/PROB GROUP FOR MOST
LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER
WIND GUSTS WITH CONDITIONS DROPPING TO MVFR/IFR IN THE HEAVIER SHOWERS
AT TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS
A 35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
642 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...FORECAST ON TRACK. MADE ONLY MINOR UPDATES TO SKY GRIDS
BASED ON SATELLITE TRENDS.
ORIGINAL...HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE
VALLEY WILL WEAKEN TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE
CENTRAL GREAT LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND
SHOULD BE NEAR THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE
NAM. THE GFS AND SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER
ALL MODELS INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING
AND AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS
SHOWERS/TSTMS ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP
INTO WESTERN COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN
ON THE NAM ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING
CHANCES FOR THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE
MORNING AND INTO THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES ARE IN PLACE OVER THE REGION TONIGHT WITH SOME BR
DEVELOPING MAINLY NE OHIO BETWEEN 10-13Z. SOME SITES WILL SEE MVFR
AND POSSIBLY IFR VISIBILITIES FOR A FEW HOURS.
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE AHEAD OF
A FRONT LATE THIS AFTERNOON INTO TONIGHT. HAVE INCLUDED A PROB GROUP
FOR MOST LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER WIND
GUSTS WITH CONDITIONS DROPPING TO IFR IN THE HEAVIER SHOWERS AT
TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS A
35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
350 AM EDT FRI AUG 2 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE TENNESSEE AND LOWER OHIO VALLEY WILL MOVE
SOUTH TODAY AND ALLOW A TROUGH OF LOW PRESSURE TO DROP SOUTHEAST
ACROSS THE AREA TONIGHT AND EARLY SATURDAY. HIGH PRESSURE WILL
MOVE SOUTHEAST ACROSS THE AREA SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
HIGH PRESSURE OVER THE LOWER OHIO AND TENNESSEE VALLEY WILL WEAKEN
TODAY AND ALLOW A COLD FRONT TO DROP ACROSS THE CENTRAL GREAT
LAKES. A SURFACE WAVE WILL DEVELOP ON THE FRONT AND SHOULD BE NEAR
THE THUMB OF MICHIGAN BY EVENING ACCORDING TO THE NAM. THE GFS AND
SREF ARE A BIT WEAKER WITH THIS FEATURE HOWEVER ALL MODELS
INCREASE MOISTURE FROM THE WEST DURING THE LATE MORNING AND
AFTERNOON AHEAD OF THE SYSTEM. RADAR ALREADY SHOWS SHOWERS/TSTMS
ALREADY DEVELOPING INVOF ORD AND HRRR BRINGS PRECIP INTO WESTERN
COUNTIES BY MID/LATE MORNING. INCREASING CAPE SHOWN ON THE NAM
ACCOMPANYING THE MOISTURE SO WOULD EXPECT INCREASING CHANCES FOR
THUNDERSTORMS FROM THE WEST THROUGH THE MID/LATE MORNING AND INTO
THE AFTERNOON. HIGHS GENERALLY 76 TO 81.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
THIS EVENING AND OVERNIGHT MODELS SHOW A SHORT WAVE DROPPING
ACROSS THE CENTRAL GREAT LAKES AS THE COLD FRONT DROPS INTO THE
NRN COUNTIES. WITH INGREDIENTS IN PLACE...EXPECTING A DECENT CHANCE
OF PRECIP ACROSS THE AREA THROUGH THE NIGHT AND INTO SATURDAY
MORNING BEFORE TAPERING FROM THE NORTH DURING THE DAY SATURDAY AS
DRY AIR AND HIGH PRESSURE BUILD FROM THE NORTH. FOLLOWED SREF
TIMING WITH A COMPROMISE IN POPS LEAVING LIKELY FOR THE CATEGORY
THROUGH THE NIGHT. WILL BEGIN SATURDAY WITH CHANCE POPS NORTH AND
LIKELY SOUTH AS MODELS START THE DAY WITH DEEP MOISTURE STILL
ACROSS MUCH OF THE AREA AND THE FRONT ALSO STILL ACROSS THE CWA.
SATURDAY NIGHT MOISTURE WILL BE ALL BUT OUT OF THE AREA. WILL HAVE
A SLIGHT CHANCE POP EAST JUST TO COVER ANY LEFTOVER SHOWERS BUT
FOR THE MOST PART EXPECT DRY CONDITIONS. SUNDAY THROUGH MONDAY
EXPECT DRY CONDITIONS WITH HIGH PRESSURE ACROSS THE AREA. MONDAY
NIGHT DID BRING SLIGHT CHANCE POPS BACK TO THE WEST DURING THE
NIGHT AS THE SURFACE HIGH DRIFTS EAST AND THE GFS SHOWS INCREASING
MOISTURE IN A GENERAL OVERRUNNING PATTERN. STILL HOWEVER WOULD
EXPECT MOST WILL REMAIN DRY AS BEST OVERRUNNING/LIFT AND
INSTABILITY WILL REMAIN WELL WEST OF THE AREA. HIGHS GENERALLY
UNREMARKABLE FOR THIS TIME OF YEAR...MOSTLY REACHING 75 TO
80...COOLEST EAST AND WARMEST WEST.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
HEIGHTS WILL REBOUND SOME ON TUESDAY AS ONE UPPER LOW CURLS
NORTHEAST TOWARDS NOVA SCOTIA AND A SECONDARY ONE DEVELOPS OVER
MANITOBA. THE FLOW ALOFT ACTUALLY BECOMES NEARLY ZONAL ON THE
SOUTHERN PERIPHERY OF THE BROAD UPPER TROUGH EXTENDING ACROSS
CENTRAL AND EASTERN CANADA. TIMING CHANCES OF PRECIPITATION WILL BE
CHALLENGING IN THE EXTENDED AS MODELS STRUGGLE TO RESOLVE SHORTWAVES
MOVING THROUGH THE FLOW ALOFT. TUESDAY LOOKS LIKE A MOSTLY DRY DAY
AS HIGH PRESSURE EXITING TO THE EAST REMAINS IN CONTROL WITH A
FAIRLY DRY AIRMASS. ALTHOUGH MODELS HAVE SHOWN POOR RUN TO RUN
CONTINUITY IN THIS PATTERN...CHANCES FOR SHOWERS AND THUNDERSTORMS
INCREASE ON WEDNESDAY AS A WARM FRONT IS PULLED OVER THE REGION
AHEAD THE NEXT COLD FRONT THAT PUSHES SOUTH ACROSS THE AREA
THURSDAY. MODELS ARE STARTING TO HINT AT SOME FAIRLY STRONG WARM
ADVECTION AHEAD OF THE FRONT AND TEMPERATURES ON WEDNESDAY(POSSIBLY
LINGERING INTO THURSDAY) MAY NEED TO BE RAISED SEVERAL DEGREES INTO
THE MID 80S. HAVE TRENDED HIGHS UP BUT KEPT THE FORECAST ON THE COOL
SIDE OF MEX GUIDANCE GIVEN THE UNCERTAINTY IN PATTERN EVOLUTION AND
NORTHERN REACH OF THAT WARM FRONT.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
CLEAR SKIES ARE IN PLACE OVER THE REGION TONIGHT WITH SOME BR
DEVELOPING MAINLY NE OHIO BETWEEN 10-13Z. SOME SITES WILL SEE MVFR
AND POSSIBLY IFR VISIBILITIES FOR A FEW HOURS.
MOISTURE AND CHANCES FOR SHOWERS AND THUNDERSTORMS INCREASE AHEAD OF
A FRONT LATE THIS AFTERNOON INTO TONIGHT. HAVE INCLUDED A PROB GROUP
FOR MOST LOCATIONS...STARTING IN TOL/FDY AT 21Z AND CLE AT 00Z.
THUNDERSTORMS WILL CONTAIN LOCALLY HEAVY RAIN AND SOME STRONGER WIND
GUSTS WITH CONDITIONS DROPPING TO IFR IN THE HEAVIER SHOWERS AT
TIMES. WINDS WILL ALSO BE RATHER BREEZY DURING THE AFTERNOON AS A
35-40 KNOT LOW LEVEL JET DEVELOPS ALOFT. SURFACE WINDS MAY GUST
TO 25-30 KNOTS DURING THE LATE AFTERNOON...WITH THE STRONGEST
WINDS EXPECTED AT TOL/FDY/CLE.
.OUTLOOK...AREAS OF NON-VFR FRIDAY NIGHT INTO SATURDAY WITH
SHOWERS/STORMS.
&&
.MARINE...
SOUTHWEST WINDS WILL INCREASE FROM WEST TO EAST ACROSS THE LAKE
INTO THIS EVENING AHEAD OF THE NEXT FRONT THAT WILL PUSH SOUTH
ACROSS THE LAKE OVERNIGHT. WINDS WILL APPROACH 20 KNOTS ON THE EAST
HALF OF THE LAKE FOR A FEW HOURS WITH WAVES APPROACHING 4 FEET.
ALTHOUGH SOMEWHAT MARGINAL...A SMALL CRAFT ADVISORY WILL LIKELY BE
NEEDED FOR A PERIOD OF TIME ON THE EAST END OF THE LAKE TONIGHT.
WINDS WILL VEER AROUND TO THE NORTHWEST ON SATURDAY BEHIND THE FRONT
BUT WILL GENERALLY BE AROUND 10 KNOTS AS THE TROUGH LINGERS IN THE
VICINITY OF THE LAKE...INCREASING ON SUNDAY AS A SECONDARY COLD
FRONT PUSHES SOUTH. HIGH PRESSURE WILL THEN BUILD EAST ACROSS THE
GREAT LAKES FROM MONDAY INTO TUESDAY WITH IMPROVING MARINE
CONDITIONS.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS TULSA OK
848 PM CDT SAT AUG 3 2013
...UPDATE...
.DISCUSSION...
FORECAST IS LARGELY ON TRACK...WITH THE MAIN CHANGES BEING TO
SPEED UP THE INCREASE IN POPS TONIGHT AND EARLY TOMORROW BY ABOUT
3 HOURS IN ACCORDANCE WITH THE LATEST OBSERVATIONAL AND MESOSCALE
MODEL DATA. THE LATEST HRRR HAS A FAIRLY GOOD HANDLE ON THE
ONGOING STORMS ACROSS THE OKLAHOMA AND TEXAS PANHANDLES...AND INTO
NORTHWEST OKLAHOMA. THIS ACTIVITY SHOULD CONTINUE TO INCREASE
OVERNIGHT AND TRACK TO THE EAST AND SOUTHEAST ALONG THE
INSTABILITY AXIS NEAR AND JUST SOUTH OF THE OKLAHOMA/KANSAS
BORDER. ALTHOUGH SOME OF THE FLASH FLOOD WATCH AREA /NAMELY THE
ARKANSAS COUNTIES/ MAY NOT SEE HEAVY RAIN UNTIL AFTER 12Z...IT
APPEARS INCREASINGLY LIKELY THAT PARTS OF THE NORTHEAST OKLAHOMA
WATCH AREA WILL SEE RAINS BEFORE THEN. DUE TO THIS...THE WATCH
WILL NOW BEGIN AT 09Z. RAINFALL AMOUNTS STILL LOOK TO BE IN THE 1
TO 2 INCH RANGE ACROSS THE WATCH AREA...WITH LOCALLY HIGHER
AMOUNTS. RELATIVELY MINOR TWEAKS WERE MADE TO OTHER FORECAST
ELEMENTS.
&&
.PREV DISCUSSION... /ISSUED 625 PM CDT SAT AUG 3 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
ONGOING LIGHT CONVECTION ACROSS NE OK WILL LIKELY CONTINUE THROUGH
THE EVENING WITH LITTLE TO NO FLIGHT IMPACTS. A LARGE THUNDERSTORM
COMPLEX IS EXPECTED TO MOVE INTO NE OK LATE TONIGHT...AND CONTINUE
INTO NW AR AROUND SUNRISE WITH CORRESPONDING AVIATION IMPACTS
PERSISTING INTO THE AFTERNOON.
PREV DISCUSSION... /ISSUED 326 PM CDT SAT AUG 3 2013/
DISCUSSION...
OVERNIGHT/EARLY MORNING MCS PROVED TO BE AN EFFICIENT
RAINMAKER...WITH 3+ INCH RAINFALL AMOUNTS AND LOCALIZED FLOODING
REPORTED ACROSS NW AR. ONLY A FEW LINGERING SHOWERS NOTED ACROSS THE
FORECAST AREA AT THIS TIME...BUT EXPECT YET ANOTHER BOUT OF
SHOWERS/THUNDERSTORMS LATE TONIGHT AND INTO TOMORROW.
SHORT-RANGE GUIDANCE IS SIMILAR KEYING ON A SUBTLE MID-LEVEL
SHORTWAVE ACROSS THE CNTRL ROCKIES ROUNDING THE TOP OF THE RIDGE AND
MOVING INTO KS LATE TONIGHT. EXPECT DEVELOPMENT TO OCCUR IN
ASSOCIATION WITH THIS FEATURE LATER THIS AFTERNOON/EVENING ACROSS
PARTS OF WRN KS...WITH VEERING LOW-LEVEL JET AIDING AN EWD/SEWD
MOVEMENT INTO FAR NE OK/NW AR BY SUNDAY MORNING. WITH PRECIP WATER
VALUES REMAINING AT OR ABOVE 2 INCHES...EXPECT LOCALLY HEAVY RAINFALL
ACROSS SOME AREAS THAT HAVE ALREADY RECEIVED SEVERAL INCHES OF RAIN
OVER THE PAST 5-10 DAYS. WILL GO WITH A FLASH FLOOD WATCH FOR SUNDAY
FOR FAR NERN OK AND NW AR. WATCH MAY NEED TO BE EXTENDED INTO SUNDAY
NIGHT WITH FORECAST AREA REMAINING UNDER NWLY UPPER FLOW.
UPPER RIDGE EXPANDS SOME BY EARLY NEXT WEEK...WITH LOW-LEVEL FLOW
BECOMING MORE SWLY. THIS WILL BRING IN WARMER AIR AND SHOULD
SHUNT MOST OF THE CONVECTION TO OUR N...ALTHOUGH WILL KEEP SOME LOW
POPS GOING ALONG THE NRN FRINGES OF THE FORECAST AREA. WILL LIKELY
NEED HEAT HEADLINES FOR MONDAY AND TUESDAY...WITH AFTERNOON HEAT
INDICES LIKELY BREACHING 105F ACROSS A LARGE PART OF THE AREA.
A WEAK FRONTAL BOUNDARY IS EXPECTED TO DROP INTO THE REGION
WEDNESDAY NIGHT AND LIKELY STALL NEAR THE RED RIVER FOR THE END OF
THE WEEK. ECMWF RATHER BULLISH WITH POST-FRONTAL PRECIP AND COOLER
TEMPS THURSDAY/FRIDAY...AND HAVE GONE WITH A GENERAL GFS/ECWMF BLEND
FOR NOW.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM 4 AM SUNDAY TO 7 PM SUNDAY FOR OKZ056-
OKZ057-OKZ058-OKZ063.
AR...FLASH FLOOD WATCH FROM 4 AM SUNDAY TO 7 PM SUNDAY FOR ARZ001-
ARZ002-ARZ010-ARZ011.
&&
$$
SHORT TERM...22
AREA FORECAST DISCUSSION
NWS TULSA OK
649 AM CDT FRI AUG 2 2013
.DISCUSSION...
THE 12Z TAF DISCUSSION IS INCLUDED BELOW.
&&
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
VFR CONDITIONS WILL PREVAIL FOR THE MAJORITY OF THE TAF PERIOD.
BETTER TSRA CHANCES WILL BE ACROSS FAR NE OK AND NW AR WHERE
EITHER TEMPO OR VCTS MENTIONS ARE INCLUDED.
LACY
&&
.PREV DISCUSSION... /ISSUED 331 AM CDT FRI AUG 2 2013/
DISCUSSION...
THUNDERSTORM COMPLEX MOVING INTO SOUTHEAST KANSAS LOOKS TO
AFFECT PORTIONS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
THIS MORNING. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT
WITH BRINGING THIS COMPLEX THROUGH NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS BEFORE IT DISSIPATES. BEST CHANCES OF SHOWERS AND THUNDERSTORMS
THIS MORNING WILL BE ALONG AND NORTH OF HIGHWAY 412. ADDITIONAL SHOWERS
AND THUNDERSTORMS MAY DEVELOP LATER THIS AFTERNOON AND EVENING ALONG
ANY LEFTOVER OUTFLOW BOUNDARIES. WILL NOT ISSUE ANY HEAT HEADLINES TODAY
WITH ONLY A FEW LOCATIONS HITTING CRITERIA THIS AFTERNOON.
THUNDERSTORM COMPLEXES MOVING OUT OF KANSAS WILL AFFECT PORTIONS OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE NEXT FEW NIGHTS AS
THE AREA REMAINS ON THE EDGE OF THE NORTHWESTERLY FLOW ALOFT. THIS
CHANGES SOMEWHAT TOWARDS MID-WEEK AS THE MID-LEVEL HIGH BUILDS OVER
THE AREA. A FRONTAL BOUNDARY MAKES A RUN INTO THE AREA THURSDAY
INTO FRIDAY AS A MID-LEVEL SHORTWAVE SWEEPS ACROSS THE GREAT LAKES
KEEPING CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 97 78 97 75 / 20 20 20 20
FSM 96 76 98 75 / 10 30 20 20
MLC 98 77 99 75 / 10 20 20 20
BVO 94 76 95 72 / 40 30 20 30
FYV 91 75 92 72 / 20 40 20 20
BYV 88 73 91 72 / 40 50 30 20
MKO 95 75 97 73 / 10 30 20 20
MIO 90 75 93 73 / 50 40 20 30
F10 97 78 98 74 / 10 20 20 20
HHW 98 76 100 75 / 0 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...30
AREA FORECAST DISCUSSION
NWS TULSA OK
331 AM CDT FRI AUG 2 2013
.DISCUSSION...
THUNDERSTORM COMPLEX MOVING INTO SOUTHEAST KANSAS LOOKS TO
AFFECT PORTIONS OF NORTHEAST OKLAHOMA AND NORTHWEST ARKANSAS
THIS MORNING. THE LAST FEW RUNS OF THE HRRR HAVE BEEN CONSISTENT
WITH BRINGING THIS COMPLEX THROUGH NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS BEFORE IT DISSIPATES. BEST CHANCES OF SHOWERS AND THUNDERSTORMS
THIS MORNING WILL BE ALONG AND NORTH OF HIGHWAY 412. ADDITIONAL SHOWERS
AND THUNDERSTORMS MAY DEVELOP LATER THIS AFTERNOON AND EVENING ALONG
ANY LEFTOVER OUTFLOW BOUNDARIES. WILL NOT ISSUE ANY HEAT HEADLINES TODAY
WITH ONLY A FEW LOCATIONS HITTING CRITERIA THIS AFTERNOON.
THUNDERSTORM COMPLEXES MOVING OUT OF KANSAS WILL AFFECT PORTIONS OF
EASTERN OKLAHOMA AND NORTHWEST ARKANSAS FOR THE NEXT FEW NIGHTS AS
THE AREA REMAINS ON THE EDGE OF THE NORTHWESTERLY FLOW ALOFT. THIS
CHANGES SOMEWHAT TOWARDS MID-WEEK AS THE MID-LEVEL HIGH BUILDS OVER
THE AREA. A FRONTAL BOUNDARY MAKES A RUN INTO THE AREA THURSDAY
INTO FRIDAY AS A MID-LEVEL SHORTWAVE SWEEPS ACROSS THE GREAT LAKES
KEEPING CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 97 78 97 75 / 20 20 20 20
FSM 96 76 98 75 / 10 30 20 20
MLC 98 77 99 75 / 10 20 20 20
BVO 94 76 95 72 / 40 30 20 30
FYV 91 75 92 72 / 20 40 20 20
BYV 88 73 91 72 / 40 50 30 20
MKO 95 75 97 73 / 10 30 20 20
MIO 90 75 93 73 / 50 40 20 30
F10 97 78 98 74 / 10 20 20 20
HHW 98 76 100 75 / 0 10 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...30
LONG TERM....10
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
203 AM EDT FRI AUG 2 2013
.SYNOPSIS...
THE COLD FRONT HAS PUSHED THROUGH MOST OF THE AREA...BUT THE
UPPER TROUGH IS APPROACHING FROM THE WEST. IT SHOULD PASS
OVERHEAD TONIGHT...LEAVING GENERALLY ZONAL FLOW ALOFT FOR THE
NEXT FEW DAYS. A SECONDARY COLD FRONT WILL MOVE THROUGH THE REGION
ON SATURDAY AND BRING ANOTHER PERIOD OF SHOWERS TO THE AREA.
UNSEASONABLY COOL AND DRY WEATHER SHOULD THEN PREVAIL FROM SUNDAY
INTO MONDAY AS A CANADIAN HIGH PRESSURE SYSTEM MIGRATES SOUTHEAST
FROM THE NORTHERN PLAINS INTO THE MID-ATLANTIC STATES.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
WATER VAPOR IMAGERY AT 05Z SHOWS POTENT SHORTWAVE TROF LIFTING
THRU NE PA AND EXITING THE AREA. IN IT/S WAKE...MCLEAR SKIES AND
LIGHT WINDS ARE ALREADY RESULTING IN AREAS OF RADIATION FOG ACROSS
THE W MTNS AND ALSO ACROSS THE SUSQ VALLEY...WHERE GROUND IS WET
FROM YESTERDAY/S RAINFALL. LATEST HRRR SUPPORTS THIS IDEA OF THE
BIGGEST FOG CONCERN ACROSS THE W MTNS AND SUSQ VALLEY THRU ARND
12Z.
TEMPS ON TRACK TO BOTTOM OUT FROM ARND 50F OVR THE NW MTNS...TO
THE L/M60S ACROSS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
SFC HIGH AND ASSOCIATED AREA OF LOW PWATS CENTERED OVER THE
CENTRAL APPALACHIANS SHOULD PROVIDE FAIR AND COOL WX FOR MOST OF
CENTRAL PA TODAY. A FAST-MOVING SHORTWAVE...ENTERING THE W GRT
LKS AT 06Z...WILL SWEEP THRU CENTRAL PA DURING THE LATE AM AND
AFTN HOURS...AS IT ROUNDS BASE OF UPPER LVL TROF. LATEST MDL
GUIDANCE SUGGESTS THERE WILL BE JUST ENOUGH MOISTURE AHEAD OF THIS
FEATURE TO SQUEEZE OUT A FEW ISOLD SHOWERS ACROSS THE AREA. TIMING
WOULD BE LATE AM ACROSS THE W MTNS AND DURING THE AFTN ACROSS THE
EASTERN COUNTIES.
AS UPSTREAM SATL IMAGERY WOULD SUGGEST...EXPECT SUNSHINE TO
PREDOMINATE ACROSS MOST OF CENTRAL PA TODAY. POCKET OF COLD AIR
ALOFT TRACKING ACROSS UPSTATE NY MAY RESULT IN A MORE EVEN MIX OF
SUN AND CU ACROSS THE NORTH...WHILE MAINLY SUNNY SKIES PREVAIL
ELSEWHERE. GEFS MEAN 8H TEMPS ARND 13C ARE A BIT BELOW NORMAL FOR
EARLY AUGUST AND SHOULD TRANSLATE TO HIGH TEMPS FROM THE L70S OVR
THE HIGHEST TERRAIN OF THE ALLEGHENIES...TO THE L80S ACROSS THE
SUSQ VALLEY.
ADDITIONAL SHORTWAVE ENERGY AND ASSOC WEAK SFC LOW WILL APPROACH
FROM THE WEST FRIDAY NIGHT. WAA AHEAD OF THIS FEATURE WILL LIKELY
SPREAD CLOUDS AND SHOWERS INTO CENTRAL PA FRIDAY NIGHT. A BLEND OF
LATEST OPER AND ENSEMBLE MDL DATA SUGGESTS THE HIGHEST CHC OF RAIN
FRI NIGHT WILL BE NORTH OF THE I 80 CORRIDOR.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE MODELS SHOW A COMPLETE CHANGE AS THEY TAKE INTO ACCOUNT OF
MONSOONAL MOISTURE IN COORDINATION WITH THE WESTERLY FLOW. THOSE
INGREDIENTS SHOULD WORK IN CONJUNCTION WITH A SHORT WAVE
TRAVERSING THROUGH THE AREA WILL ALLOW FOR A GOOD CHC OF RAIN FOR
MUCH OF CENTRAL PA SATURDAY. INCREASING SPEED WIND SHEAR AHEAD OF
THIS SYSTEM COULD POTENTIALLY RESULT IN A SVR WX THREAT BY SAT
AFTN. MUCH UNCERTAINTY REMAINS WITH REGARD TO THE EXACT TRACK OF
SFC LOW AND AMT OF CLOUD COVER. THE STRONGEST REA OF MOISTURE IS
IN SOUTHERN PA WHICH COULD BECOME MODERATELY UNSTABLE IN SOME MDL
SCENARIOS...SO THIS AREA WILL HAVE TO BE WATCHED.
FAIRLY WIDE CONSENSUS AMONG MED RANGE GUIDANCE FOR ANOTHER STRETCH OF
COOL/DRY WX SUNDAY INTO EARLY NEXT WEEK...AS COLD FRONT PRESSES
SOUTH OF PA AND COOL...CANADIAN HIGH PRES BUILDS SE ACROSS THE AREA.
00Z GEFS 8H TEMPS REMAIN BLW NORMAL SUN-MON WHEN DAYTIME MAXES WILL
LIKELY BE 5-10F BLW NORMAL. EC ENSEMBLE MEAN SHOWS AXIS OF UPPER
TROUGH SHIFTING FROM THE NORTHEAST CONUS TO THE MIDWEST BY THE
MIDDLE OF NEXT WEEK...INDICATING SLIGHTLY WARMER...MORE HUMID AIR
MAY RETURN.
THE NEXT CHANCE FOR PRECIPITATION WILL BE FROM A ANOTHER TROUGH
WITH NORTHWESTERLY FLOW NEXT TUESDAY THROUGH WEDNESDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
STORMS NOW OUT OF THE AREA.
REAL STRONG STORMS STAYED JUST TO THE SOUTH OF OUR AREA.
ONE STORM HAD A HOOK ECHO...AN INTERESTING EVENING.
ANYWAY...MAIN CONCERN OVERNIGHT WILL BE THE POTENTIAL
FOR FOG FORMATION. DEWPOINT GRADIENT ACROSS THE AREA.
HARD TO SEE COLD FRONT MOVING MUCH FURTHER SE.
WAS CONCERN ABOUT THE FAR FAR NW AREAS LIKE BFD LATER
TONIGHT...AS MORE CONVECTION OVER OH WITH RATHER STRONG UPPER
LVL TROUGH WAS MOVING EASTWARD. HOWEVER...TIME OF DAY...AND
LACK OF SFC CONVERGENCE AND MOISTURE TO THE WEST AND NORTH...
HAS RESULTED IN STORMS FALLING APART.
MOST OF FRIDAY LOOKS OK...BUT AN ISOLATED SHOWER POSSIBLE
ACROSS N PA...GIVEN COLD AIR ALOFT.
MORE IN THE WAY OF WIDESPREAD SHOWERS AND THUNDERSTORMS
LIKELY LATE FRIDAY NIGHT INTO EARLY SUNDAY MORNING...AS
STRONG DYNAMICS COMBINE WITH WARM ADVECTION TO PRODUCE
ADVERSE WEATHER CONDITIONS. WIDESPREAD MVFR AND EVEN IFR
CONDITIONS POSSIBLE AT TIMES.
IMPROVING CONDITIONS FOR LATER SUNDAY...AS HIGH PRESSURE
BUILDS INTO THE AREA.
OUTLOOK...
SAT...MVFR/IFR WITH SHOWERS AND STORMS.
SUN...MVFR AND IFR EARLY WITH SHOWERS...THEN
IMPROVING CONDITIONS.
MON-TUE...VFR. NO SIG WX.
&&
.EQUIPMENT...
KCCX WIDEBAND COMMS HAS FAILED. VZ TECHS TROUBLESHOOTING.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/DEVOIR
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
339 PM CDT FRI AUG 2 2013
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 338 PM CDT FRI AUG 2 2013
MCV PRECIPITATION EXITING THE FAR SOUTHEASTERN CWA AT MID
AFTERNOON...AND MONITORING THE TRAILING EDGE OF NOW SLOWLY
DISSIPATING COMPLEX OF SHOWERS AND ISOLATED THUNDER ACROSS
SOUTHEASTERN SD. SUPPORT FOR LATTER PRECIP IS MID LEVEL LIFT FORCING
WITH WAVE MOVING THROUGH NORTHEAST AND TAILING TOWARD CENTRAL SD.
FEATURE KEEPS CLIPPING ALONG LATE AFTERNOON AND INDICATION ON WATER
VAPOR LOOP FOR SLIGHTLY RISING HEIGHTS IN WHAT HAS BEEN A GRADUALLY
STABILIZED OVERALL AIRMASS AS PRECIPITATION HAS WORKED THROUGH. MID
LEVEL BOUNDARY REMAINS INTO THE NIGHT RIGHT ACROSS THE AREA...BUT
CANNOT REALLY FIND ANY DISTINCT FEATURE TO THINK IT WILL ACTIVATE
BEHIND FEATURE THIS AFTERNOON FOR QUITE SOME TIME. THEREFORE...
HAVE CUT BACK POPS FAIRLY QUICKLY FROM WEST TO EAST THROUGH THE
REMAINDER OF THE AFTERNOON. WHILE HRRR HAS HAD A PRETTY GOOD IDEA TO
EVOLUTION OF PRECIP TODAY...ITS TIMING HAS LEFT QUITE A BIT TO BE
DESIRED...AND LIKELY CONTINUES TOO SLOW OVERALL. RETAINED ISOLATED
THUNDER MENTION MAINLY THROUGH THE MISSOURI CORRIDOR EASTWARD
THROUGH NORTHWEST IOWA...AS WILL STILL HAVE A BIT OF ELEVATED
INSTABILITY TO WORK THROUGH...AND WOULD BE PRUDENT TO KEEP AN EYE TO
THE SOUTHERN END OF THE LINE AS MAY YET PULSE UP IN STRENGTH A BIT
AND PRODUCE A LITTLE HAIL. MUCH OF THE REMAINDER OF THE NIGHT SHOULD
REMAIN QUIET...WITH PARTLY TO MOSTLY CLOUDY SKIES AFTER PERHAPS A
SHORT PERIOD OF POST CONVECTIVE CLEARING.
LATER TONIGHT INTO EARLY SATURDAY...ANOTHER WAVE MOVING THROUGH THE
ROCKIES WILL LIKELY INITIATE NOCTURNAL DEVELOPMENT THROUGH THE HIGH
PLAINS. PROPAGATION OF COMPLEX SHOULD KEEP MOSTLY CLEAR OF THE
AREA...BUT POTENTIAL FOR SOMETHING DEVELOPING INITIALLY NORTH OF THE
BLACK HILLS TO CLIP THE FAR SOUTHWEST. EASTERN LOCATIONS WILL BE
PROTECTED OF SORTS BY RIDGE OF HIGH PRESSURE AND SOMEWHAT DRIER
NORTHEAST TO EAST LOW LEVEL FLOW. SHOULD BE FAIRLY OPEN TO MIX
TOWARD 850-800 HPA ON SATURDAY WHICH WOULD YIELD AN ABUNDANCE OF MID
70S TO NEAR 80 ACROSS THE AREA.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 338 PM CDT FRI AUG 2 2013
FAIRLY ACTIVE WEATHER PATTERN CONTINUES FOR THE BULK OF NEXT WEEK
WITH SEVERAL WAVE DROPPING ACROSS THE NORTHERN PLAINS ALONG THE
NORTHWESTERLY UPPER LEVEL FLOW. OVERALL TEMPERATURE TRENDS REMAIN
BELOW NORMAL WITH ONLY MINOR WARMING TRENDS BACK INTO THE LOW AND
MID 80S...FOLLOWED BY COOLING INTO THE 70S BEHIND THE BOUNDARIES.
MID LEVEL BOUNDARY IS EXPECTED TO SET UP ACROSS WESTERN SOUTH DAKOTA
AND NEAR THE MISSOURI VALLEY SATURDAY EVENING. SOME SCATTERED TO
ISOLATED THUNDERSTORMS ARE EXPECTED TO FIRE TO THE WEST OF THE
FORECAST AREA BY AFTERNOON AND COULD DRIFT INTO OUR FAR WESTERN
COUNTIES IN THE EVENING AND OVERNIGHT. MODELS TRACK A MID LEVEL INTO
THE NORTHERN HIGH PLAINS ON SUNDAY AND THROUGH THE FORECAST AREA
SUNDAY NIGHT. WITH SOME WEAK INSTABILITY EXTENDING INTO SOUTH
CENTRAL SOUTH DAKOTA...SCATTERED CONVECTION WILL AGAIN INITIATE
ACROSS OUR WESTERN COUNTIES SUNDAY AFTERNOON AND TRACK ACROSS THE
REMAINDER OF THE FORECAST AREA OVERNIGHT.
MODELS A BIT MORE UNCERTAIN WITH THE TIMING OF WAVES IN THE
EXTENDED. THE GFS BRINGS ANOTHER DECENT SHORTWAVE THROUGH THE
FORECAST AREA MONDAY NIGHT...WHILE THE ECMWF AND GEM ARE MORE
SUBTLE. BETTER AGREEMENT IS SEEN TUESDAY NIGHT WITH A WAVE AND COLD
FRONT DROPPING THROUGH THE REGION. THIS SHOULD ALLOW A COOLER AND
DRIER PUSH TO BRING A BREAK TO THE ACTIVE WEATHER PATTERN WEDNESDAY
THROUGH FRIDAY. DID SCALE BACK ON THE SPOTTY PRECIPITATION CHANCES
GIVEN BY THE ALLBLEND IN THE EXTENDED WITH THE EXCEPTION OF SOUTH
CENTRAL SD WHICH COULD SEE SOME HIGH PLAINS CONVECTION DRIFT INTO
THE AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI AUG 2 2013
PERSISTENT PRECIPITATION ACROSS MUCH OF THE AREA AT MIDDAY WITH
FIRST CLUSTER OF SHOWERS IN FAR SOUTHEAST SOUTH DAKOTA AND
NORTHWEST IOWA...AND SECONDARY AREA SPREADING THROUGH CENTRAL SD.
FOR THE MOST PART...PRIMARILY VFR CONDITIONS CAN BE EXPECTED...
ALTHOUGH ANY HEAVIER SHOWERS OR ISOLATED THUNDERSTORMS MAY BRIEFLY
PUSH VISIBILITY TO MVFR. A FEW MVFR CEILINGS WILL ALSO LINGER
AROUND THE KSUX AREA THROUGH THE AFTERNOON. OVERALL...THUNDERSTORM
THREAT IS FAIRLY ISOLATED AND LIMITED TO THE SOUTHERN HALF OF THE
AREA...MAINLY SOUTH OF A CHAMBERLAIN TO SPENCER IA LINE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1248 PM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1057 AM CDT FRI AUG 2 2013
LOCATED NEAR PLATTE SD...MCV FROM OVERNIGHT CONVECTION HAS FLARED
UP QUITE AN AREA OF CONVECTION IN THE FSD CWA EARLY THIS
MORNING...AND EVEN ONE BRIEF PULSE TO A SEVERE HAILER IN THE FAR
SOUTHWEST. FOR THE CURRENT TIME... OTHER THAN SOME OF THE AREAS
ON THE SOUTHERN FLANK OF THE COMPLEX WHERE ELEVATED INSTABILITY
IS SOMEWHAT STRONGER...MOST OF THE AREA HAS DEGRADED TO A LARGE
STRATIFORM AREA WITH EMBEDDED CONVECTIVE ELEMENTS. TO SAY THE
SHORT RANGE MODELS HANDLED POORLY WOULD PERHAPS EVEN BE A
COMPLIMENT...OTHER THAN THE HRRR WHICH HAS HAD THE RIGHT
DEVELOPMENT/EVOLUTION TRENDS TO THE SOUTHEAST AREA... BUT DOES
NOT ADEQUATELY ACKNOWLEDGE THE MORE DYNAMICALLY FORCED AREA OF
SHOWERS/CONVECTION ACROSS THE NORTHWEST PORTIONS OF SD.
HAVE BOOSTED POPS CONSIDERABLY ACROSS THE SOUTHWEST 2/3 OF THE
AREA...AND MAY BE ALL BUT THE EXTREME NORTHEAST THAT EVENTUALLY
SEES A FEW SHOWERS...WITH THUNDER LIMITED TO WEST THROUGH SOUTH.
AS FAR AS SEVERE THREAT...APPEARS TO HAVE MOSTLY PASSED...
ALTHOUGH PERHAPS CANNOT IGNORE A MINIMAL THREAT FOR A MARGINAL
HAILER IN THE EXTREME SOUTH/SOUTHWEST DURING THE EARLY TO MID
AFTERNOON ALONG SOUTHERN PERIPHERY OF SECONDARY AREA OF CONVECTION
WHERE WILL HAVE PROXIMITY TO SLIGHTLY BETTER ELEVATED INSTABILITY.
PRECIP AND CLOUDS WILL HAVE A DEVASTATING IMPACT ON TEMPS TODAY...
AND IN ADDITION TO SLOWING THE DIURNAL TREND...SLASHED HIGHS BY
A SOLID 5-8F OVER MUCH OF THE AREA EXCEPT THE FAR EAST/NORTHEAST.
MAY HAVE TO DROP READINGS EVEN FURTHER...AND THIS WOULD BRING SOME
NEAR RECORD COLD HIGHS ONCE AGAIN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI AUG 2 2013
CONFIDENCE ON CONVECTIVE DEVELOPMENT/EVOLUTION IS EXTREMELY LOW FOR
TODAY WITH NOT A SINGLE MODEL HANDLING OVERNIGHT CONVECTION WELL.
CURRENT RADAR SHOWING CONVECTION DEVELOPING OVER WESTERN SOUTH
DAKOTA VERY EARLY THIS MORNING...THOUGH NOT SURE IF ANY OF THIS
ACTIVITY WILL MAKE IT INTO OUR WESTERN ZONES WITH STORM MOTION TO
THE SOUTHEAST AND A MORE STABLE/DRIER ATMOSPHERE OVER OUR AREA. A
STATIONARY BOUNDARY IS SITUATED SOMEWHERE ACROSS THE AREA...THOUGH
VERY HARD TO DEFINE WITH SURFACE OBS...WITH ASSORTED OUTFLOW
BOUNDARIES AROUND THE REGION. THE ASSUMPTION AT THIS POINT IS THAT
MOST CONVECTIVE DEVELOPMENT WILL BE FOCUSED IN THE VICINITY OF THIS
BOUNDARY TODAY...WHERE EVER IT MAY END UP. IT IS PROGGED TO BE
DRAPED ACROSS OUR FAR SOUTH THIS AFTERNOON...SO KEPT THE HIGHER POPS
OVER THAT AREA AND UP THROUGH THE MISSOURI RIVER VALLEY WHERE
PROGGED INSTABILITY WILL BE GREATER. MODELS DO INDICATE THE
ATMOSPHERE BECOMING MORE STABLE THROUGH THE DAY AS BETTER
INSTABILITY IS SHUNTED TO THE SOUTH...SO THINK THAT THE BETTER
CHANCE OF ANY SEVERE WEATHER MAY BE TO THE SOUTH OF OUR CWA. THAT
BEING SAID...THE BEST CHANCE OF SEVERE STORM DEVELOPMENT IF IT WERE
TO OCCUR WOULD BE IN THE AFTERNOON THROUGH OUR LOWER SOUTH
CENTRAL/MISSOURI RIVER ZONES WHERE LINGERING INSTABILITY/STRONG
DIRECTIONAL SHEAR MAY EXIST. MODELS CONTINUE TO COME IN COOLER THAN
PREVIOUS RUNS WITH REGARD TO HIGHS TODAY UNDER AN EASTERLY LOW LEVEL
FLOW...SO DROPPED HIGHS A COUPLE MORE DEGREES...RUNNING GENERALLY
MID AND UPPER 70S...TO AROUND 80 TROUGH OUR SOUTHERN MOST IOWA ZONES.
BY TONIGHT...EXPECT ANY LINGERING THUNDERSTORM ACTIVITY IN OUR SOUTH
TO DIMINISH AS DRIER AIR CONTINUES TO FILTER INTO THE REGION AND THE
STATIONARY BOUNDARY PULLS OUT OF OUR AREA. 925 MB TEMPERATURES COOL
SLIGHTLY OVERNIGHT UNDER A NORTHEASTERLY LOW LEVEL FLOW...WITH LOWS
DROPPING INTO THE MID 50S TO NEAR 60.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 2 2013
FSD FORECAST AREA WILL BE UNDER THE INFLUENCE OF COOL CANADIAN HIGH
PRESSURE AND EASTERLY LOW LEVEL FLOW...MAKING FOR A COOL EARLY
AUGUST WEEKEND WITH HIGH TEMPS ONLY IN THE 70S. RETURN FLOW SETS UP
ACROSS WESTERN SODAK FOR SATURDAY NIGHT IN RESPONSE TO PAC NW VORT
MAX TRAVERSING THE UPPER RIDGE. MODELS NOW MOSTLY IN AGREEMENT WITH
INSTABILITY AXIS REMAINING SOUTH AND WEST...WITH A 850MB BOUNDARY
SITTING JUST SOUTH OF MO RIVER. HAVE CONCENTRATED HIGHEST CHANCE POPS
ACROSS THE MO RIVER VALLEY AREA AND WEST OF THE JAMES RIVER
ACCORDINGLY...BUT OVERALL HAVE LOWERED POPS FOR SUNDAY/SUNDAY
NIGHT. MUCAPES REMAIN BELOW 1000 J/KG AS WELL FOR SUNDAY SO SEVERE
WEATHER THREAT IS VERY LOW. ASSOCIATED LOW LEVEL COLD FRONT PUSHES
THROUGH SUNDAY OVERNIGHT AND FOR THE FIRST PART OF MONDAY WITH
SOME SCT CONVECTION STILL POSSIBLE.
CONTINUED FAST NORTHWEST FLOW ALOFT BETWEEN CANADIAN CLOSED LOW AND
SOUTHERN CONUS RIDGE WILL CONTINUE TO MAKE CONVECTIVE FORECASTING
VERY CHALLENGING. MODELS PICKING UP ON MORE SIGNIFICANT SHORT
WAVE/FRONT FROM CANADIAN LOW THAT SWINGS THROUGH ON MONDAY NIGHT
THROUGH TUESDAY OR TUESDAY NIGHT PER THE GFS OR ECMWF. LOOKS LIKE
SOME DECENT RETURN FLOW WITH GFS ADVERTISING VERY HIGH MUCAPES FOR
TUESDAY AFTERNOON ACROSS MUCH OF THE FORECAST AREA. DEEP LAYER
SHEAR 50 KTS TUESDAY AFTERNOON MAKES ORGANIZED CONVECTION A
POSSIBILITY. HOWEVER...WITH TIMING AND PLACEMENT ISSUES IN THE
MODELS AS OF LATE...CONFIDENCE OF ANY SEVERE THREAT IS LOW. WILL
MONITOR FOR CONSISTENCY IN SUBSEQUENT MODEL RUNS.
OTHERWISE RETROGRADING UPPER CANADIAN LOW WILL BRING EVEN COOLER
TEMPS FOR THE LATTER HALF OF THE WEEK...ALTHOUGH THE LATEST ECMWF IS
NOT QUITE AS BULLISH WITH THE COLD AIR ADVECTION AS IT WAS
YESTERDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM CDT FRI AUG 2 2013
PERSISTENT PRECIPITATION ACROSS MUCH OF THE AREA AT MIDDAY WITH
FIRST CLUSTER OF SHOWERS IN FAR SOUTHEAST SOUTH DAKOTA AND
NORTHWEST IOWA...AND SECONDARY AREA SPREADING THROUGH CENTRAL SD.
FOR THE MOST PART...PRIMARILY VFR CONDITIONS CAN BE EXPECTED...
ALTHOUGH ANY HEAVIER SHOWERS OR ISOLATED THUNDERSTORMS MAY BRIEFLY
PUSH VISIBILITY TO MVFR. A FEW MVFR CEILINGS WILL ALSO LINGER
AROUND THE KSUX AREA THROUGH THE AFTERNOON. OVERALL...THUNDERSTORM
THREAT IS FAIRLY ISOLATED AND LIMITED TO THE SOUTHERN HALF OF THE
AREA...MAINLY SOUTH OF A CHAMBERLAIN TO SPENCER IA LINE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JM
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1058 AM CDT FRI AUG 2 2013
.UPDATE...
ISSUED AT 1057 AM CDT FRI AUG 2 2013
LOCATED NEAR PLATTE SD...MCV FROM OVERNIGHT CONVECTION HAS FLARED
UP QUITE AN AREA OF CONVECTION IN THE FSD CWA EARLY THIS
MORNING...AND EVEN ONE BRIEF PULSE TO A SEVERE HAILER IN THE FAR
SOUTHWEST. FOR THE CURRENT TIME... OTHER THAN SOME OF THE AREAS
ON THE SOUTHERN FLANK OF THE COMPLEX WHERE ELEVATED INSTABILITY
IS SOMEWHAT STRONGER...MOST OF THE AREA HAS DEGRADED TO A LARGE
STRATIFORM AREA WITH EMBEDDED CONVECTIVE ELEMENTS. TO SAY THE
SHORT RANGE MODELS HANDLED POORLY WOULD PERHAPS EVEN BE A
COMPLIMENT...OTHER THAN THE HRRR WHICH HAS HAD THE RIGHT
DEVELOPMENT/EVOLUTION TRENDS TO THE SOUTHEAST AREA... BUT DOES
NOT ADEQUATELY ACKNOWLEDGE THE MORE DYNAMICALLY FORCED AREA OF
SHOWERS/CONVECTION ACROSS THE NORTHWEST PORTIONS OF SD.
HAVE BOOSTED POPS CONSIDERABLY ACROSS THE SOUTHWEST 2/3 OF THE
AREA...AND MAY BE ALL BUT THE EXTREME NORTHEAST THAT EVENTUALLY
SEES A FEW SHOWERS...WITH THUNDER LIMITED TO WEST THROUGH SOUTH.
AS FAR AS SEVERE THREAT...APPEARS TO HAVE MOSTLY PASSED...
ALTHOUGH PERHAPS CANNOT IGNORE A MINIMAL THREAT FOR A MARGINAL
HAILER IN THE EXTREME SOUTH/SOUTHWEST DURING THE EARLY TO MID
AFTERNOON ALONG SOUTHERN PERIPHERY OF SECONDARY AREA OF CONVECTION
WHERE WILL HAVE PROXIMITY TO SLIGHTLY BETTER ELEVATED INSTABILITY.
PRECIP AND CLOUDS WILL HAVE A DEVASTATING IMPACT ON TEMPS TODAY...
AND IN ADDITION TO SLOWING THE DIURNAL TREND...SLASHED HIGHS BY
A SOLID 5-8F OVER MUCH OF THE AREA EXCEPT THE FAR EAST/NORTHEAST.
MAY HAVE TO DROP READINGS EVEN FURTHER...AND THIS WOULD BRING SOME
NEAR RECORD COLD HIGHS ONCE AGAIN.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 341 AM CDT FRI AUG 2 2013
CONFIDENCE ON CONVECTIVE DEVELOPMENT/EVOLUTION IS EXTREMELY LOW FOR
TODAY WITH NOT A SINGLE MODEL HANDLING OVERNIGHT CONVECTION WELL.
CURRENT RADAR SHOWING CONVECTION DEVELOPING OVER WESTERN SOUTH
DAKOTA VERY EARLY THIS MORNING...THOUGH NOT SURE IF ANY OF THIS
ACTIVITY WILL MAKE IT INTO OUR WESTERN ZONES WITH STORM MOTION TO
THE SOUTHEAST AND A MORE STABLE/DRIER ATMOSPHERE OVER OUR AREA. A
STATIONARY BOUNDARY IS SITUATED SOMEWHERE ACROSS THE AREA...THOUGH
VERY HARD TO DEFINE WITH SURFACE OBS...WITH ASSORTED OUTFLOW
BOUNDARIES AROUND THE REGION. THE ASSUMPTION AT THIS POINT IS THAT
MOST CONVECTIVE DEVELOPMENT WILL BE FOCUSED IN THE VICINITY OF THIS
BOUNDARY TODAY...WHERE EVER IT MAY END UP. IT IS PROGGED TO BE
DRAPED ACROSS OUR FAR SOUTH THIS AFTERNOON...SO KEPT THE HIGHER POPS
OVER THAT AREA AND UP THROUGH THE MISSOURI RIVER VALLEY WHERE
PROGGED INSTABILITY WILL BE GREATER. MODELS DO INDICATE THE
ATMOSPHERE BECOMING MORE STABLE THROUGH THE DAY AS BETTER
INSTABILITY IS SHUNTED TO THE SOUTH...SO THINK THAT THE BETTER
CHANCE OF ANY SEVERE WEATHER MAY BE TO THE SOUTH OF OUR CWA. THAT
BEING SAID...THE BEST CHANCE OF SEVERE STORM DEVELOPMENT IF IT WERE
TO OCCUR WOULD BE IN THE AFTERNOON THROUGH OUR LOWER SOUTH
CENTRAL/MISSOURI RIVER ZONES WHERE LINGERING INSTABILITY/STRONG
DIRECTIONAL SHEAR MAY EXIST. MODELS CONTINUE TO COME IN COOLER THAN
PREVIOUS RUNS WITH REGARD TO HIGHS TODAY UNDER AN EASTERLY LOW LEVEL
FLOW...SO DROPPED HIGHS A COUPLE MORE DEGREES...RUNNING GENERALLY
MID AND UPPER 70S...TO AROUND 80 TROUGH OUR SOUTHERN MOST IOWA ZONES.
BY TONIGHT...EXPECT ANY LINGERING THUNDERSTORM ACTIVITY IN OUR SOUTH
TO DIMINISH AS DRIER AIR CONTINUES TO FILTER INTO THE REGION AND THE
STATIONARY BOUNDARY PULLS OUT OF OUR AREA. 925 MB TEMPERATURES COOL
SLIGHTLY OVERNIGHT UNDER A NORTHEASTERLY LOW LEVEL FLOW...WITH LOWS
DROPPING INTO THE MID 50S TO NEAR 60.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 341 AM CDT FRI AUG 2 2013
FSD FORECAST AREA WILL BE UNDER THE INFLUENCE OF COOL CANADIAN HIGH
PRESSURE AND EASTERLY LOW LEVEL FLOW...MAKING FOR A COOL EARLY
AUGUST WEEKEND WITH HIGH TEMPS ONLY IN THE 70S. RETURN FLOW SETS UP
ACROSS WESTERN SODAK FOR SATURDAY NIGHT IN RESPONSE TO PAC NW VORT
MAX TRAVERSING THE UPPER RIDGE. MODELS NOW MOSTLY IN AGREEMENT WITH
INSTABILITY AXIS REMAINING SOUTH AND WEST...WITH A 850MB BOUNDARY
SITTING JUST SOUTH OF MO RIVER. HAVE CONCENTRATED HIGHEST CHANCE POPS
ACROSS THE MO RIVER VALLEY AREA AND WEST OF THE JAMES RIVER
ACCORDINGLY...BUT OVERALL HAVE LOWERED POPS FOR SUNDAY/SUNDAY
NIGHT. MUCAPES REMAIN BELOW 1000 J/KG AS WELL FOR SUNDAY SO SEVERE
WEATHER THREAT IS VERY LOW. ASSOCIATED LOW LEVEL COLD FRONT PUSHES
THROUGH SUNDAY OVERNIGHT AND FOR THE FIRST PART OF MONDAY WITH
SOME SCT CONVECTION STILL POSSIBLE.
CONTINUED FAST NORTHWEST FLOW ALOFT BETWEEN CANADIAN CLOSED LOW AND
SOUTHERN CONUS RIDGE WILL CONTINUE TO MAKE CONVECTIVE FORECASTING
VERY CHALLENGING. MODELS PICKING UP ON MORE SIGNIFICANT SHORT
WAVE/FRONT FROM CANADIAN LOW THAT SWINGS THROUGH ON MONDAY NIGHT
THROUGH TUESDAY OR TUESDAY NIGHT PER THE GFS OR ECMWF. LOOKS LIKE
SOME DECENT RETURN FLOW WITH GFS ADVERTISING VERY HIGH MUCAPES FOR
TUESDAY AFTERNOON ACROSS MUCH OF THE FORECAST AREA. DEEP LAYER
SHEAR 50 KTS TUESDAY AFTERNOON MAKES ORGANIZED CONVECTION A
POSSIBILITY. HOWEVER...WITH TIMING AND PLACEMENT ISSUES IN THE
MODELS AS OF LATE...CONFIDENCE OF ANY SEVERE THREAT IS LOW. WILL
MONITOR FOR CONSISTENCY IN SUBSEQUENT MODEL RUNS.
OTHERWISE RETROGRADING UPPER CANADIAN LOW WILL BRING EVEN COOLER
TEMPS FOR THE LATTER HALF OF THE WEEK...ALTHOUGH THE LATEST ECMWF IS
NOT QUITE AS BULLISH WITH THE COLD AIR ADVECTION AS IT WAS
YESTERDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 602 AM CDT FRI AUG 2 2013
SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE WEST
AND SOUTH TODAY...THOUGH CONFIDENCE IN TIMING AND EVOLUTION IS LOW
WITH MODELS HANDLING THE CONVECTION POORLY. CONVECTION MORE LIKELY
TO BRIEFLY AFFECT KHON AND KSUX THAN KFSD...AND ANY HEAVIER
THUNDERSTORM ACTIVITY COULD RESULT IN SHORT LIVED LOWERING OF
CONDITIONS. THERE WILL BE A POSSIBILITY OF MVFR CEILINGS AROUND
KSUX LATER TONIGHT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...JM
LONG TERM...
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SPOKANE WA
231 PM PDT Fri Aug 2 2013
.SYNOPSIS...
Unsettled weather will continue this evening with rain showers
and a few thunderstorms. Lingering showers will be common near
the Canadian border through Saturday. Summer weather will return
next week with a warm up back to normal and small chances of
mainly mountain thunderstorms each day.
&&
.DISCUSSION...
Rest of today and tonight: Clouds continue to thin across
the East Slopes, Okanogan Highlands, and western Columbia Basin.
This has resulted in an increasing risk for convective showers and
isolated thunderstorms. The main threats with these storms will be
heavy rainfall given the juicy air mass in place (precipitable
water values near to over 1.00") and nearly stationary movement.
Per the last few runs of the HRRR which did a superior job with
the placement of the current convection...this activity this
evening is expected to expand/shift west toward the East Slopes of
the Cascades and portions of Douglas and Grant Counties. This
mainly focuses over northern sections of Chelan and
central/western Okanogan Counties but will need to be closely
monitored for more development closer to the larger burn scars
outside Wenatchee. There is still a risk that a few of these cells
will impact some of the scars from the Byrd, First Creek, and Goat
Fires of 2012.
Meanwhile, the deformation band over the se continues to
shrink and HRRR suggest this will continue to dissipate this
evening. These features tend to linger longer then expected and
this was evident with each run of the HRRR this afternoon which
now lingers the band through 02z. Partial clearing south of this
band has resulted in developing showers from the Blue Mtns to the
L-C Valley to the Camas Prairie. Nothing real strong but a stray
thunderstorm will be possible before sunset.
The next feature of note will be a stronger wave that will wrap
around the northern periphery of the low. This wave was over NW MT
today and has since crossed into SE BC. Some guidance dives this
wave along with a cluster of heavier showers into the northern
mountains this evening into the overnight periods but others,
including the latest run of the HRRR now keep this feature just
along or north of the border. Given the high degree of
uncertainty...we have kept at least a chance of showers for most
locations through the overnight periods but confidence is not
exceptionally high locations like Spokane, CDA, and the Palouse
will experience much more precipitation once the current
deformation band dissipates. /sb
Saturday through Monday night...A closed low that brought the
moist and unsettled weather will pull away from the area into
northern Montana on Saturday. This will bring about the beginning
of a warming and drying trend into Monday. However a broad upper
level trough will remain over the area with a weak short wave
clipping the Canadian border Sunday into Monday. This combined
with abundant low level moisture should provide adequate
instability for diurnally driven showers and mainly isolated
thunderstorms primarily along the East Slopes of the Cascades, and
northern mountains. The NAM model has uncapped CAPE values of
300-700 J/KG each afternoon in these areas. Weak shear values will
support mainly pulse type thunderstorms that last only brief
periods of time. However light steering flow will also be slow
moving storms that could produce locally heavy rain. JW
Tuesday through Friday...A struggle between a ridge trying to
poke its way into the region, and upper level troughs on either side of
the ridge will be ongoing for much of next week. While the ridge
may help keep things on the warm side of normal (by about 3 to 6
degrees), an active large scale trough over the central US will
likely allow thunderstorms to develop each afternoon over the
higher terrain. Our confidence is not high that the precipitation
will make it much off the terrain, at least until a better
organized weather system gets closer to the region. The models are
hinting at one such feature moving over the Inland Northwest by
the end of the week. If this were to occur, temperatures would
likely cool by a few degrees and precipitation chances would be
higher over a larger area. ty
&&
.AVIATION...
18Z TAFS...An expansive upper-level low over the region will bring
widespread showers and isolated thunderstorms to much of the region.
MVFR/IFR Cigs/Vis will be found under a persistent band of light to
moderate rain stretching across the Central ID Panhandle and
portions of SE WA including the Spokane-CDA Area. Further
west...light scattered showers currently should transition to
showers and isolated thunderstorms btwn 20-03z with the potential
for heavy rain and localized vis/cig restrictions and KMWH/KEAT/KOMK
will carry the highest threat for any thunder. The exception is
near the Camas Prairie and Blue Mtns where partial clearing could
lead to isold -tsra vcnty of KLWS into the early evening. Activity
will wane overnight but a weak midlevel disturbance is likely to get
hung over Ern Wa and keep a cluster of light showers into the early
morning. Showers will once again form along the higher terrain near
17z on Sat. /sb
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 55 74 57 84 61 87 / 50 30 10 10 10 10
Coeur d`Alene 53 74 53 83 55 85 / 60 40 10 10 10 10
Pullman 50 74 49 83 50 87 / 50 20 10 10 10 10
Lewiston 56 82 59 92 62 94 / 40 10 10 10 10 10
Colville 52 78 52 87 52 87 / 90 40 20 20 10 10
Sandpoint 51 71 47 81 49 82 / 80 60 30 10 10 20
Kellogg 50 74 51 82 54 84 / 60 40 10 10 10 10
Moses Lake 59 81 58 89 61 92 / 60 10 10 10 0 10
Wenatchee 61 81 61 90 65 92 / 40 20 10 10 0 10
Omak 60 84 57 89 59 92 / 90 30 20 20 20 10
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
320 PM CDT FRI AUG 2 2013
.VERY SHORT TERM...TONIGHT AND SATURDAY.
SURFACE COOL FRONT/DRYLINE HAS SHIFTED SOUTH. RENEWED CONVECTIVE
DEVELOPMENT IN NRN IL INVOF BETTER LOW LEVEL FRONTAL CONVERGENCE.
MUCH DRIER AIR ADVECTING SE INTO SRN WI PER ISODROSOTHERM ANALYSIS.
500 MILLIBAR PROGS SHOW ELONGATED/SHEARED VORT ACROSS THE CWA DURING
THE NIGHT. MID/HIGH LEVEL CLOUDS ON THE INCREASE INTO THE EVENING
ASSOCIATED WITH RAIN MOVING ACROSS NRN IA. THE HRRR BRUSHES THE
SOUTH WITH THIS. THE 00Z ECMWF HINTS AT THIS AS WELL WITH OTHER
MODELS SHOWING DRY AFTER 00Z. CONSSHORT POPS SKIRT THE FAR SOUTH
WITH SMALL POPS EARLY THIS EVENING. SEEMS REASONABLE AND WILL BLEND
WITH THE SRN NEIGHBORS.
NORTHWEST UPPER FLOW PERSISTS. ALL MODELS BRING A 500 MILLIBAR
SHORTWAVE ACROSS. THE NAM HAS THE STRONGER LOOK TO THIS FEATURE
WHILE OTHER MODELS SHOW A CONTINUATION OF THE MORE SHEARED LOOK TO
THE VORT PATTERN. BUFKIT SOUNDINGS SHOW THAT THE AIRMASS WILL BE DRY
AND STABLE SO STICKING WITH THE ADVERTISED DRY FORECAST. SURFACE
HIGH BUILDS IN FROM CANADA AND RIDGES SOUTHEAST INTO WRN GREAT
LAKES. 925 TEMPS 17-19C TRANSLATE TO MID TO UPPER 70S WITH SOME
COOLER TEMPS EVOLVING AS WINDS TURN MORE NE NEAR LAKE MICHIGAN.
.SHORT TERM...SATURDAY NIGHT THROUGH MONDAY.
SHORT TERM GUIDANCE IN GOOD AGREEMENT ON HIGH PRESSURE AND DRY
COLUMN IN CONTROL OF OUR WEATHER THROUGH SUNDAY. DAYTIME
TEMPERATURES WILL REMAIN SLIGHTLY BELOW NORMAL FOR EARLY AUGUST AS
NORTHWEST LOW LEVEL FLOW PERSISTS. WARMER AIR BEGINS TO SLOWLY
RETURN SUNDAY NIGHT AND MONDAY. 12Z NAM MOST AGRESSIVE SHOWING MCS
SKIRTING SOUTHWEST WI SUNDAY NIGHT DESPITE RELATIVELY WEAKER LOW
LEVEL RETURN FLOW. 12Z NAM APPEARS TO BE OVERDOING AMOUNT OF UPPER
LEVEL DIVERGENCE ASSOCD WITH 3H JET. EVEN THOUGH OTHER GUIDANCE
INCLUDING GFS AND ECMWF FOCUSES FARTHER WEST...LOW TO MID LEVEL RH
DOES INCREASE OVERNIGHT WITH WEAK LAYER Q-VECTOR CONVERGENCE
SPREADING INTO SRN WI. NOT ENOUGH CONFIDENCE AT THIS POINT TO
TOTALLY REMOVE POPS FOR LATER SUN NIGHT. WL CONTINUE POPS FOR
MONDAY AS WELL AS WEAK MID-LEVEL TROUGH APPROACHES AND COLUMN
MOISTURE CONTINUES TO INCREASE.
.LONG TERM...MONDAY NIGHT THROUGH FRIDAY.
MEDIUM RANGE GUIDANCE IN FAIR AGREEMENT ON CARRYING SHORT WAVE
TROUGH AND WEAK COLD FRONT ACROSS WESTERN GREAT LAKES DURING THE
FIRST HALF OF NEXT WEEK. SOME TIMING DIFFERENCES WITH GEM AND GFS
SLIGHTLY FASTER THAN THE LATEST ECMWF. NEVER THE LESS...LEANING
TOWARD THREAT OF CONVECTION WITH SURGE OF WARM AIR ADVECTION MONDAY
NIGHT INTO EARLY TUESDAY WITH CHANCE RETURNING LATER TUESDAY AND
TUESDAY NIGHT ASSOCIATED WITH STRONGER LAYER FORCING WITH CDFNT AND
MID-LEVEL WAVE.
THEN SLOW MOVING UPPER LOW OVER SOUTH CENTRAL CANADA LINGERS TO THE
NORTH THROUGH THURSDAY NIGHT. DRIER...ZONAL FLOW TO THE SOUTH OF
THIS FEATURE SHOULD RESULT IN NEAR OR SLIGHTLY BELOW NORMAL TEMPS
THROUGH THE LATER PART OF THE EXTENDED PERIOD. CANADIAN UPPER LOW
CONTINUES TO WEAKEN LATE IN THE WEEK AND GETS NUDGED EAST FRIDAY AND
SATURDAY.
&&
.AVIATION /00Z TAFS/...
SURFACE COOL FRONT/DRY LINE SHIFTING SE OF THE AREA WITH DRIER AIR
BEING BROUGHT IN ON NW WINDS. MOST CU VFR THOUGH A FEW SITES MVFR.
EXPECT THIS TO DISSIPATE DIURNALLY. HRRR DOES SHOW THE NW IA COMPLEX
BRUSHING SW WI LATER THIS EVE BUT WILL LEAVE PRECIP MENTION OUT OF
TAF SITES. HIGH PRESSURE BUILDS IN TO DOMINATE FOR SATURDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
.CONFIDENCE...
TONIGHT AND SATURDAY...MEDIUM.
SATURDAY THROUGH SUNDAY...HIGH.
SUNDAY NIGHT AND MONDAY...LOW TO MEDIUM.
MONDAY NIGHT THROUGH WEDNESDAY...MEDIUM.
THURSDAY AND FRIDAY...MEDIUM TO HIGH.
$$
VERY SHORT TERM AND AVIATION/MARINE...PC
SHORT TERM/LONG TERM...MBK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1200 PM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI AUG 2 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER THE PACIFIC NORTHWEST AS WELL AS FROM
HUDSON BAY INTO THE GREAT LAKES...WITH RIDGING IN-BETWEEN ALONG THE
LEE OF THE ROCKIES. THE FORECAST AREA REMAINS IN NORTHWEST FLOW EAST
OF THE RIDGING. WITHIN THIS FLOW...SHORTWAVES OF NOTE WERE OVER LAKE
WINNIPEG...NORTHERN WI AND SOUTHEAST WI. THE SOUTHEAST WI SHORTWAVE
IN CONJUNCTION WITH A SURGE OF WARM ADVECTION SEEN ON 850MB VAD WIND
PROFILE DATA HELPED BRING A BAND OF SCATTERED SHOWERS AND STORMS
ACROSS THE FORECAST AREA LAST EVENING...A FEW WHICH WERE STRONG TO
SEVERE. TO THE NORTH...A COLD POOL ACCOMPANYING THE NORTHERN WI
SHORTWAVE AS WELL AS MOISTURE SEEN ON THE 00Z INL SOUNDING BROUGHT
SHOWERS AND A FEW STORMS THROUGH NORTHERN WI OVERNIGHT. WARM
ADVECTION WELL SOUTH OF THIS SHORTWAVE AND SOME LINGERING WEAK
INSTABILITY / MUCAPE LESS THAN 500 J/KG /HAS HELPED PRODUCED SHOWERS
AND SOME STORMS SOUTH OF I-90 IN THE FORECAST AREA. SO FAR
EVERYTHING IS QUIET WITH THE LAKE WINNIPEG SHORTWAVE. ON
SATELLITE...MOSTLY CLEAR SKIES ENCOMPASSED MUCH OF THE EASTERN
DAKOTAS INTO MN...THANKS TO DRYING SEEN ON THE 00Z MPX... BIS AND
ABR SOUNDINGS. THIS DRYING IS ALSO BEHIND A SURFACE COLD FRONT WHICH
CAN BE SEEN ON MPX RADAR DROPPING THROUGH MINNEAPOLIS AT THIS TIME.
850MB TEMPS BEHIND THE COLD FRONT ARE NOT MUCH COOLER THAN THOSE
AHEAD OF IT...THOUGH...WITH READINGS GENERALLY 13-15C PER 00Z
SOUNDING DATA.
SYNOPTIC OVERVIEW...
THE NORTHWEST FLOW PATTERN CONTINUES TO PERSIST THROUGH THE SHORT
TERM PERIOD. THE SHORTWAVES OVER NORTHERN WI AS WELL AS OVER LAKE
WINNIPEG ARE PROGGED TO STAY OFF TO OUR NORTH AND EAST.
MEANWHILE...NUMEROUS WEAK SHORTWAVES ARE SUGGESTED TO COME OUT OF
THE PACIFIC NORTHWEST TROUGH AND DROP THROUGH THE FORECAST AREA
TONIGHT.
DETAILS...
THE COLD FRONT LURKING JUST OFF TO THE NORTHWEST AT 08Z LOOKS TO
PUSH THROUGH THE FORECAST AREA DURING THE MORNING HOURS. ONCE IT
PASSES...THE CONCERN FOR PRECIPITATION ENDS AS THE DRIER AIR OVER
THE DAKOTAS AND MN FLOWS IN. DESPITE THE SHORTWAVES CROSSING THE
FORECAST AREA TONIGHT...WHICH APPEAR LIKELY TO BRING SOME MID/HIGH
CLOUDS THROUGH...SOUNDINGS DEPICT PLENTY OF DRY AIR BELOW 700MB TO
PREVENT ANY PRECIPITATION. 02.00Z GFS/NAM/ECMWF/REGIONAL CANADIAN
ARE ALL DRY...FURTHER INCREASING CONFIDENCE FOR A DRY FORECAST
TONIGHT. 850MB TEMPS IN THE 12-14C RANGE PLUS A MIX OF SUN THROUGH
PASSING MID/HIGH CLOUDS SHOULD ALLOW TEMPERATURES TO CLIMB WELL INTO
THE 70S. A FEW LOW 80S ARE POSSIBLE. IT APPEARS THE MID AND HIGH
CLOUDS SHOULD GRADUALLY CLEAR OUT TONIGHT AND WITH LIGHT WINDS AND
DRIER AIR...SOME OF THE TYPICAL COLD SPOTS COULD DROP INTO THE LOW
50S. OTHERWISE...MID/UPPER 50S APPEAR LIKELY. SOME VALLEY FOG MAY
OCCUR...PARTICULARLY IN THE SMALLER TRIBUTARIES TO THE MISSISSIPPI
RIVER. THERE MAY BE TOO MUCH EVENING CLOUD COVER...AFTERNOON
DEWPOINT MIXING/DRYING TODAY AND LATE DIMINISHING IN WIND TO ALLOW
FOG IN THE MISSISSIPPI RIVER CHANNEL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI AUG 2 2013
SYNOPTIC OVERVIEW...
02.00Z ECMWF/GFS/CANADIAN CONTINUE THE NORTHWEST FLOW PATTERN OVER
THE FORECAST AREA THROUGH THE WEEKEND AS TROUGHING REMAINS IN PLACE
OVER SOUTHEAST CANADA INTO THE GREAT LAKES. THERE ARE NOW TRENDS FOR
THE UPPER FLOW OVER THE NORTHERN TIER OF THE U.S. TO START TURNING
MORE ZONAL MONDAY AND TUESDAY...IN RESPONSE TO WHAT BASICALLY COULD
BE CONSIDERED A POLAR VORTEX DROPPING OUT OF HUDSON BAY INTO THE
LAKE WINNIPEG REGION. EVOLUTION AND TRACK OF THE POLAR VORTEX AFTER
TUESDAY IS A LITTLE MORE UNCERTAIN...WITH THE 02.00Z CANADIAN
CARVING OUT MUCH MORE OF A TROUGH ACROSS THE WESTERN GREAT LAKES
COMPARED TO THE 02.00Z ECMWF/GFS WHICH ARE FLATTER WITH THE FLOW.
DETAILS...
FOR THE WEEKEND...HIGH PRESSURE CURRENTLY CENTERED IN NORTHERN
SASKATCHEWAN LOOKS TO DROP SOUTHEAST INTO THE FORECAST AREA ON
SUNDAY...FOLLOWING THE NORTHWEST FLOW PATTERN ALOFT. DRY AIR
ACCOMPANYING THE SURFACE HIGH WILL BE ENOUGH TO KEEP THE WEEKEND
DRY. MAY SEE SOME DIURNAL CUMULUS GROWTH BUT OTHERWISE MOSTLY CLEAR
SKIES ARE LIKELY TO PREVAIL. 850MB TEMPS ARE PROGGED 10-12C ON
SATURDAY AND 8-11C ON SUNDAY...ABOUT 1-1.5 STANDARD DEVIATIONS ABOVE
NORMAL. STILL WITH THE SUN WE SHOULD BE ABLE TO HOLD HIGH TEMPS IN
THE 70S. SATURDAY NIGHT LIKELY TO BE COOL WITH HIGH PRESSURE AND DRY
AIR IN PLACE. LEANED TOWARDS THE COOLER END OF GUIDANCE WHICH ALLOWS
FOR 40S IN SOME OF THE TYPICAL COLD SPOTS OF WI. VALLEY FOG LIKELY
SATURDAY NIGHT IN THE TRIBUTARIES AND POSSIBLY THE MISSISSIPPI
CHANNEL TOO.
CONCERN FOR PRECIPITATION BEGINS TO INCREASE FOR MONDAY AND TUESDAY
WITH THE UPPER FLOW TURNING MORE ZONAL. 02.00Z ECMWF/GFS/CANADIAN
ALL SHOW THE SURFACE HIGH DRIFTING OFF TO THE EAST DURING THIS
PERIOD AS A COLD FRONT APPROACHES THE AREA FROM THE WEST. STILL
TIMING DIFFERENCES WITH THE FRONTAL PASSAGE...BUT CURRENT CONSENSUS
WOULD PUT IT COMING THROUGH SOMETIME LATE TUESDAY. 850MB MOISTURE
TRANSPORT STAYS WEST OF THE AREA SUNDAY NIGHT AND MONDAY...WHICH
SHOULD KEEP PRECIPITATION CHANCES OFF TO THE WEST. PERHAPS SOMETHING
COULD DROP INTO THE AREA ON MONDAY...PER 02.00Z GFS...BUT
CONFIDENCE IS LOW. BETTER SHOT FOR PRECIPITATION COMES MONDAY NIGHT
AS THE 850MB MOISTURE TRANSPORT AND HIGHER ELEVATED CAPE VALUES COME
INTO THE FORECAST AREA. PRECIPITATION CHANCES CONTINUE THROUGH
TUESDAY NIGHT WITH THE FRONTAL PASSAGE. THESE MAY NEED TO BE
INCREASED AS THE FRONTAL TIMING BECOMES MORE REFINED. WITH THE LOW
LEVEL WARM ADVECTION PATTERN IN PLACE MONDAY AND TUESDAY...850MB
TEMPS REBOUND TO 12-14C ON MONDAY AND PERHAPS AS HIGH AS 16-20C ON
TUESDAY. DEPENDING ON AMOUNT OF SUN ON TUESDAY...WE COULD SEE HIGH
TEMPS GO ABOVE NORMAL WITH READINGS IN THE MID TO UPPER 80S.
HOWEVER...GIVEN THE PRECIPITATION CONCERN...HAVE FOLLOWED THE
CONSENSUS HIGHS OF MID 70S ON MONDAY AND 75-80 ON TUESDAY.
FOR WEDNESDAY AND THURSDAY...ANOTHER SURGE OF DRIER AND COOLER AIR
APPEARS SLATED TO COME INTO THE AREA DURING THIS PERIOD...IN THE
WAKE OF TUESDAY/TUESDAY NIGHTS FRONTAL PASSAGE. STILL...WITH
CONCERNS ON FRONTAL TIMING AND BOTH THE 02.00Z ECMWF/CANADIAN
LINGERING SOME PRECIPITATION BACK EVEN BEHIND THE FRONT ON
WEDNESDAY...MAINTAINED 20-30 PERCENT CHANCES. ALSO KEPT SOME 20
PERCENT CHANCES NORTH OF I-90 ON THURSDAY WITH INDICATIONS OF COLDER
AIR ALOFT...BEING CLOSER TO THE TROUGHING UP TO THE NORTH. HIGHS ON
WEDNESDAY SHOULD STILL CLIMB INTO THE MID TO UPPER 70S GIVEN 12-14C
850MB TEMPS...BUT PERHAPS ONLY THE LOW TO MID 70S ON THURSDAY AS
SOME COOLER AIR FLOWS IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1200 PM CDT FRI AUG 2 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD. MID TO
HIGH LEVEL CLOUDS WILL OVERSPREAD THE AREA FROM THE WEST THIS
AFTERNOON THROUGH THIS EVENING...STREAMING OFF OF A SHOWER/STORM
COMPLEX TRACKING SOUTHEAST ACROSS WESTERN AND CENTRAL IOWA. PLAN
ON CEILINGS LOWERING TO AROUND 8KFT BY THIS EVENING. IF CLEARING
OCCURS AT KLSE SOME PATCHY FOG COULD DEVELOP ALONG THE MISSISSIPPI
RIVER VALLEY LATE TONIGHT AND PERSIST INTO EARLY SATURDAY MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1118 AM CDT FRI AUG 2 2013
.AVIATION/18Z TAFS/...SURFACE COOL FRONT/DRY LINE MOVING THROUGH
SE WI. WINDS SHIFT SW TO NW WITH THE PASSAGE OF THIS FEATURE.
STILL SOME MVFR CIGS ASSOCIATED WITH THIS. EXPECTING THIS TO MIX
OUT AND RISE TO VFR LEVELS AS THE AFTN WEARS ON. LITTLE CONCERN
FOR ADDITIONAL DEVELOPMENT BEHIND THE FRONT AS DRY PUSH PRETTY
PRONOUNCED PER 12Z KMPX SOUNDING AND SURFACE ISODROSOTHERM
ANALYSIS. HRRR DOES SHOW THE SD/NW IA COMPLEX BRUSHING SW WI LATER
THIS AFTN AND EARLY THIS EVE BUT WILL LEAVE PRECIP MENTION OUT OF
TAF SITES. HIGH PRESSURE BUILDS IN TO DOMINATE FOR SATURDAY.
PC
&&
.PREV DISCUSSION... /ISSUED 343 AM CDT FRI AUG 2 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE...MEDIUM
LOW TO MID LEVEL WARM ADVECTION/FRONTOGENESIS PATTERN AHEAD OF
APPROACHING SFC TROUGH WILL SHIFT EAST AND SOUTH THROUGH THE
MORNING...WITH TSTORMS FOLLOWING THE SAME TREND. ONLY SCT
SHOWERS/TSTORMS EXPECTED AFTER 12Z OVER THE FAR SRN CWA. CHANCE POPS
WILL CONTINUE IN THE FAR SRN CWA THROUGHOUT THE DAY AS THE SFC
TROUGH AND CAPE STALLS THERE AND OVER NRN IL...AND A WEAK COLD FRONT
THEN APPROACHES FROM THE NORTH IN THE AFTERNOON. BELIEVE MAJORITY OF
NEW DEVELOPMENT THIS AFTERNOON WILL LIKELY BE IN NRN IL WITH THE
THUNDER THREAT DIMINISHED BY EARLY EVENING OVER FAR SRN WI.
OTHERWISE...DO EXPECT SOME SUNSHINE TODAY AFTER MORNING CONVECTION
WITH 925 MB TEMPS AROUND 20-21C SUGGESTING HIGH TEMPS WILL BE IN THE
LOWER 80S. LGT NLY WINDS AND WEAK COLD ADVECTION THEN EXPECTED FOR
TNT.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
SURFACE HIGH PRESSURE WILL BUILD INTO THE AREA SATURDAY...MOVING
OVERHEAD ON SUNDAY. EXPECT A PLEASANT WEEKEND...WITH PARTLY CLOUDY
SKIES AND HIGH TEMPERATURES JUST A TAD BELOW AVERAGE VALUES FOR
EARLY AUGUST. LEFT A SMALL CHANCE FOR SHOWERS AND STORMS WEST FOR
LATER SUNDAY NIGHT AS A WEAK SHORTWAVE APPROACHES.
MONDAY THROUGH THURSDAY...FORECAST CONFIDENCE...MEDIUM
COULD SEE A FEW SHOWERS/STORMS MONDAY AS THE SHORTWAVE SLIDES
THROUGH. BETTER CHANCE FOR PRECIP TUESDAY INTO EARLY WEDNESDAY AS A
STRONGER WAVE AND COLD FRONT PUSH THROUGH THE AREA.
KEPT SOME POPS THROUGH THE DAY WEDNESDAY AS MODELS DIFFER SOMEWHAT
ON TIMING OF THE FRONT. DESPITE MODEL DIFFERENCES...LOOKS DRY BY
EVENING AS HIGH PRESSURE BEGINS TO BUILD INTO THE AREA. SHOULD BE
DRY THEN THURSDAY UNDER THE HIGH.
NO BIG CHANGE IN TEMPERATURES IS EXPECTED NEXT WEEK THROUGH
THURSDAY...WITH HIGHS REMAINING NEAR TO A COUPLE DEGREES BELOW
NORMAL.
AVIATION/12Z TAFS/...PREVAILING BROKEN CLOUD COVER FROM 5-7 KFT
THIS MORNING AS WARM ADVECTION AND SCATTERED THUNDERSTORMS MOVE
ACROSS SRN WI. CIGS AND VSBYS WILL BE REDUCED IN THE TSTORMS. LESS
COVERAGE IN TSTORMS IS EXPECTED AFTER 12Z THIS MORNING ALTHOUGH
CHANCES OF SHOWERS AND TSTORMS WILL CONTINUE OVER FAR SRN
WI...INCLUDING KENW FOR MUCH OF THE DAY AS THE SFC TROUGH STALLS
THERE. VFR CONDITIONS WILL CONTINUE TO PREVAIL THROUGH THE AFTERNOON
WITH CUMULUS CONGESTUS AROUND 5 KFT. NLY WINDS AND WEAK COLD
ADVECTION TO DRY LOW LEVEL ATMOSPHERE TNT WILL VFR CONDITIONS
CONTINUING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...GEHRING
SATURDAY THROUGH THURSDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
301 AM CDT FRI AUG 2 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 301 AM CDT FRI AUG 2 2013
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER TROUGHS OVER THE PACIFIC NORTHWEST AS WELL AS FROM
HUDSON BAY INTO THE GREAT LAKES...WITH RIDGING IN-BETWEEN ALONG THE
LEE OF THE ROCKIES. THE FORECAST AREA REMAINS IN NORTHWEST FLOW EAST
OF THE RIDGING. WITHIN THIS FLOW...SHORTWAVES OF NOTE WERE OVER LAKE
WINNIPEG...NORTHERN WI AND SOUTHEAST WI. THE SOUTHEAST WI SHORTWAVE
IN CONJUNCTION WITH A SURGE OF WARM ADVECTION SEEN ON 850MB VAD WIND
PROFILE DATA HELPED BRING A BAND OF SCATTERED SHOWERS AND STORMS
ACROSS THE FORECAST AREA LAST EVENING...A FEW WHICH WERE STRONG TO
SEVERE. TO THE NORTH...A COLD POOL ACCOMPANYING THE NORTHERN WI
SHORTWAVE AS WELL AS MOISTURE SEEN ON THE 00Z INL SOUNDING BROUGHT
SHOWERS AND A FEW STORMS THROUGH NORTHERN WI OVERNIGHT. WARM
ADVECTION WELL SOUTH OF THIS SHORTWAVE AND SOME LINGERING WEAK
INSTABILITY / MUCAPE LESS THAN 500 J/KG /HAS HELPED PRODUCED SHOWERS
AND SOME STORMS SOUTH OF I-90 IN THE FORECAST AREA. SO FAR
EVERYTHING IS QUIET WITH THE LAKE WINNIPEG SHORTWAVE. ON
SATELLITE...MOSTLY CLEAR SKIES ENCOMPASSED MUCH OF THE EASTERN
DAKOTAS INTO MN...THANKS TO DRYING SEEN ON THE 00Z MPX... BIS AND
ABR SOUNDINGS. THIS DRYING IS ALSO BEHIND A SURFACE COLD FRONT WHICH
CAN BE SEEN ON MPX RADAR DROPPING THROUGH MINNEAPOLIS AT THIS TIME.
850MB TEMPS BEHIND THE COLD FRONT ARE NOT MUCH COOLER THAN THOSE
AHEAD OF IT...THOUGH...WITH READINGS GENERALLY 13-15C PER 00Z
SOUNDING DATA.
SYNOPTIC OVERVIEW...
THE NORTHWEST FLOW PATTERN CONTINUES TO PERSIST THROUGH THE SHORT
TERM PERIOD. THE SHORTWAVES OVER NORTHERN WI AS WELL AS OVER LAKE
WINNIPEG ARE PROGGED TO STAY OFF TO OUR NORTH AND EAST.
MEANWHILE...NUMEROUS WEAK SHORTWAVES ARE SUGGESTED TO COME OUT OF
THE PACIFIC NORTHWEST TROUGH AND DROP THROUGH THE FORECAST AREA
TONIGHT.
DETAILS...
THE COLD FRONT LURKING JUST OFF TO THE NORTHWEST AT 08Z LOOKS TO
PUSH THROUGH THE FORECAST AREA DURING THE MORNING HOURS. ONCE IT
PASSES...THE CONCERN FOR PRECIPITATION ENDS AS THE DRIER AIR OVER
THE DAKOTAS AND MN FLOWS IN. DESPITE THE SHORTWAVES CROSSING THE
FORECAST AREA TONIGHT...WHICH APPEAR LIKELY TO BRING SOME MID/HIGH
CLOUDS THROUGH...SOUNDINGS DEPICT PLENTY OF DRY AIR BELOW 700MB TO
PREVENT ANY PRECIPITATION. 02.00Z GFS/NAM/ECMWF/REGIONAL CANADIAN
ARE ALL DRY...FURTHER INCREASING CONFIDENCE FOR A DRY FORECAST
TONIGHT. 850MB TEMPS IN THE 12-14C RANGE PLUS A MIX OF SUN THROUGH
PASSING MID/HIGH CLOUDS SHOULD ALLOW TEMPERATURES TO CLIMB WELL INTO
THE 70S. A FEW LOW 80S ARE POSSIBLE. IT APPEARS THE MID AND HIGH
CLOUDS SHOULD GRADUALLY CLEAR OUT TONIGHT AND WITH LIGHT WINDS AND
DRIER AIR...SOME OF THE TYPICAL COLD SPOTS COULD DROP INTO THE LOW
50S. OTHERWISE...MID/UPPER 50S APPEAR LIKELY. SOME VALLEY FOG MAY
OCCUR...PARTICULARLY IN THE SMALLER TRIBUTARIES TO THE MISSISSIPPI
RIVER. THERE MAY BE TOO MUCH EVENING CLOUD COVER...AFTERNOON
DEWPOINT MIXING/DRYING TODAY AND LATE DIMINISHING IN WIND TO ALLOW
FOG IN THE MISSISSIPPI RIVER CHANNEL.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 301 AM CDT FRI AUG 2 2013
SYNOPTIC OVERVIEW...
02.00Z ECMWF/GFS/CANADIAN CONTINUE THE NORTHWEST FLOW PATTERN OVER
THE FORECAST AREA THROUGH THE WEEKEND AS TROUGHING REMAINS IN PLACE
OVER SOUTHEAST CANADA INTO THE GREAT LAKES. THERE ARE NOW TRENDS FOR
THE UPPER FLOW OVER THE NORTHERN TIER OF THE U.S. TO START TURNING
MORE ZONAL MONDAY AND TUESDAY...IN RESPONSE TO WHAT BASICALLY COULD
BE CONSIDERED A POLAR VORTEX DROPPING OUT OF HUDSON BAY INTO THE
LAKE WINNIPEG REGION. EVOLUTION AND TRACK OF THE POLAR VORTEX AFTER
TUESDAY IS A LITTLE MORE UNCERTAIN...WITH THE 02.00Z CANADIAN
CARVING OUT MUCH MORE OF A TROUGH ACROSS THE WESTERN GREAT LAKES
COMPARED TO THE 02.00Z ECMWF/GFS WHICH ARE FLATTER WITH THE FLOW.
DETAILS...
FOR THE WEEKEND...HIGH PRESSURE CURRENTLY CENTERED IN NORTHERN
SASKATCHEWAN LOOKS TO DROP SOUTHEAST INTO THE FORECAST AREA ON
SUNDAY...FOLLOWING THE NORTHWEST FLOW PATTERN ALOFT. DRY AIR
ACCOMPANYING THE SURFACE HIGH WILL BE ENOUGH TO KEEP THE WEEKEND
DRY. MAY SEE SOME DIURNAL CUMULUS GROWTH BUT OTHERWISE MOSTLY CLEAR
SKIES ARE LIKELY TO PREVAIL. 850MB TEMPS ARE PROGGED 10-12C ON
SATURDAY AND 8-11C ON SUNDAY...ABOUT 1-1.5 STANDARD DEVIATIONS ABOVE
NORMAL. STILL WITH THE SUN WE SHOULD BE ABLE TO HOLD HIGH TEMPS IN
THE 70S. SATURDAY NIGHT LIKELY TO BE COOL WITH HIGH PRESSURE AND DRY
AIR IN PLACE. LEANED TOWARDS THE COOLER END OF GUIDANCE WHICH ALLOWS
FOR 40S IN SOME OF THE TYPICAL COLD SPOTS OF WI. VALLEY FOG LIKELY
SATURDAY NIGHT IN THE TRIBUTARIES AND POSSIBLY THE MISSISSIPPI
CHANNEL TOO.
CONCERN FOR PRECIPITATION BEGINS TO INCREASE FOR MONDAY AND TUESDAY
WITH THE UPPER FLOW TURNING MORE ZONAL. 02.00Z ECMWF/GFS/CANADIAN
ALL SHOW THE SURFACE HIGH DRIFTING OFF TO THE EAST DURING THIS
PERIOD AS A COLD FRONT APPROACHES THE AREA FROM THE WEST. STILL
TIMING DIFFERENCES WITH THE FRONTAL PASSAGE...BUT CURRENT CONSENSUS
WOULD PUT IT COMING THROUGH SOMETIME LATE TUESDAY. 850MB MOISTURE
TRANSPORT STAYS WEST OF THE AREA SUNDAY NIGHT AND MONDAY...WHICH
SHOULD KEEP PRECIPITATION CHANCES OFF TO THE WEST. PERHAPS SOMETHING
COULD DROP INTO THE AREA ON MONDAY...PER 02.00Z GFS...BUT
CONFIDENCE IS LOW. BETTER SHOT FOR PRECIPITATION COMES MONDAY NIGHT
AS THE 850MB MOISTURE TRANSPORT AND HIGHER ELEVATED CAPE VALUES COME
INTO THE FORECAST AREA. PRECIPITATION CHANCES CONTINUE THROUGH
TUESDAY NIGHT WITH THE FRONTAL PASSAGE. THESE MAY NEED TO BE
INCREASED AS THE FRONTAL TIMING BECOMES MORE REFINED. WITH THE LOW
LEVEL WARM ADVECTION PATTERN IN PLACE MONDAY AND TUESDAY...850MB
TEMPS REBOUND TO 12-14C ON MONDAY AND PERHAPS AS HIGH AS 16-20C ON
TUESDAY. DEPENDING ON AMOUNT OF SUN ON TUESDAY...WE COULD SEE HIGH
TEMPS GO ABOVE NORMAL WITH READINGS IN THE MID TO UPPER 80S.
HOWEVER...GIVEN THE PRECIPITATION CONCERN...HAVE FOLLOWED THE
CONSENSUS HIGHS OF MID 70S ON MONDAY AND 75-80 ON TUESDAY.
FOR WEDNESDAY AND THURSDAY...ANOTHER SURGE OF DRIER AND COOLER AIR
APPEARS SLATED TO COME INTO THE AREA DURING THIS PERIOD...IN THE
WAKE OF TUESDAY/TUESDAY NIGHTS FRONTAL PASSAGE. STILL...WITH
CONCERNS ON FRONTAL TIMING AND BOTH THE 02.00Z ECMWF/CANADIAN
LINGERING SOME PRECIPITATION BACK EVEN BEHIND THE FRONT ON
WEDNESDAY...MAINTAINED 20-30 PERCENT CHANCES. ALSO KEPT SOME 20
PERCENT CHANCES NORTH OF I-90 ON THURSDAY WITH INDICATIONS OF COLDER
AIR ALOFT...BEING CLOSER TO THE TROUGHING UP TO THE NORTH. HIGHS ON
WEDNESDAY SHOULD STILL CLIMB INTO THE MID TO UPPER 70S GIVEN 12-14C
850MB TEMPS...BUT PERHAPS ONLY THE LOW TO MID 70S ON THURSDAY AS
SOME COOLER AIR FLOWS IN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1147 PM CDT THU AUG 1 2013
VFR CONDITIONS EXPECTED THROUGH THE PERIOD. A FRONT WILL MOVE
THROUGH THE AIRFIELDS EARLY THIS MORNING AND CLEAR ANY SHOWER
ACTIVITY TO THE SOUTH. THERE IS A CHANCE FOR VALLEY FOG BOTH
SATURDAY AND SUNDAY MORNINGS AT KLSE. STAY TUNED FOR THOSE
DETAILS IN FUTURE FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
708 PM MDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 708 PM MDT SAT AUG 3 2013
THUNDERSTORMS HAVE WEAKENED AND SO HAVE CANCELLED THE TORNADO
WATCH FOR THE SOUTHEAST WYOMING PLAINS. STILL SOME SHOWERS AND
STORMS OVER SOUTHEAST WYOMING EARLY THIS EVENING. THE ACTIVITY
HAS BEEN DECREASING IN COVERAGE AND INTENSITY AS IT TRIES TO
MOVE FURTHER EAST. THE ATMOSPHERE OVER THE PANHANDLE SHOULD
CONTINUE TO BE STABLE TONIGHT. LOW CLOUDS AND AREAS OF FOG WILL
BE LIKELY OVER THE EAST PART OF THE CWA TONIGHT WITH SOME
LOCATIONS ALREADY WITH LOW CLOUDS. IN A RECENT UPDATE...LOWERED
POPS OVER THE PANHANDLE FOR EARLY TONIGHT AND INCREASED CLOUD
COVER OVER THE EAST PART OF THE CWA.
UPDATE ISSUED AT 344 PM MDT SAT AUG 3 2013
LONG TRACKED SEVERE THUNDERSTORM CONTINUES TO HOLD TOGETHER AND
MOVE NORTH INTO NORTHERN LARAMIE COUNTY. WENT AHEAD AND ADDED
PLATTE AND GOSHEN COUNTIES TO THE TORNADO WATCH AS THIS STORM
COULD PRODUCE SEVERE THUNDERSTORMS THERE. PLUS THE ENVIRONMENT IS
PROBABLY BETTER UP THERE FOR MORE WIDESPREAD THUNDERSTORM
DEVELOPMENT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 300 PM MDT SAT AUG 3 2013
FORECAST CHALLENGES DEAL WITH THUNDERSTORM TIMING AND LOCATION OF
SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH EVENING HOURS.
CURRENTLY...BOUNDARY LAYING ALONG THE LARAMIE RANGE EARLY THIS
AFTERNOON...SEPARATING FAIRLY DRY AIR TO THE WEST FROM REALLY
MOIST AIR TO THE EAST. DEWPOINTS IN LARAMIE IN THE MID 30S...HERE
AT CHEYENNE WE ARE SEEING UPPER 50S AND OUT BY SIDNEY...MID 60
DEWPOINTS. STRATUS HAS BEEN SLOW TO BREAK UP LATE THIS
MORNING/EARLY THIS AFTERNOON. STILL GETTING REPORTS OF STRATUS IN
THE PANHANDLE AND AS FAR WEST AS TORRINGTON. CHEYENNE HAS REMAINED
UNDER MOSTLY SUNNY SKIES AND CUMULUS HAS BEGUN TO BUILD OVER THE
SOUTHERN LARAMIE RANGE...EXTENDING SOUTH INTO THE MOUNTAINS OF
COLORADO. GETTING OBSERVED LIGHTNING STRIKES OVER CENTRAL
COLORADO...BUT SO FAR...THE CHEYENNE CWFA HAS REMAINED PRETTY MUCH
ECHO FREE. MONSOONAL MOISTURE CONTINUES TO MOVE INTO SOUTH CENTRAL
WYOMING ON WATER VAPOR IMAGERY...MAINLY OVER SOUTHERN CARBON AND
ALBANY COUNTIES THROUGH THE MORNING HOURS.
DO BELIEVE ITS ONLY A MATTER OF TIME FOR CONVECTION TO INITIATE
THIS AFTERNOON. LATEST SPC MESOANALIST PAGE SHOWING SURFACE BASED CAPE
VALUES INCREASING TO AROUND 3500 J/KG JUST SOUTH OF THE CWFA IN
COLORADO WITH AROUND 2500 TO 3000 J/KG JUST NUDGING INTO THE SOUTH
LARAMIE RANGE. STILL SEEING SOME CONVECTIVE INHIBITION EAST OF
CHEYENNE...SPREADING NORTH AND EAST. SPC MESOANALYST PAGE SHOWING
STILL AROUND 100-150 J/KG CONVECTIVE INHIBITION FOR THESE AREAS.
CURRENTLY THINKING AND THIS IS BACKED UP BY LATEST HRRR FORECASTS
IS THAT CONVECTION WILL INITIATE JUST WEST OF CHEYENNE...THEN
SLOWLY SPREAD EAST AND NORTH AS THE CAP ERODES.
MAIN THREATS WITH THUNDERSTORMS TODAY LOOKS TO BE LARGE HAIL AND
DAMAGING WINDS. BULK SHEAR ON THE ORDER OF 40 TO 45KTS. BUT LATER
THIS AFTERNOON...NAM SOUNDINGS ARE SHOWING HELICITY VALUES
INCREASING ABOVE 200 M2/S2 FOR CHEYENNE AND THE SOUTHERN
PANHANDLE...SO CAN NOT RULE OUT SOME TORNADIC SUPERCELLS LATE THIS
AFTERNOON AND EARLY EVENING. LCLS PRETTY LOW...WITH NAM FORECASTING
ANYWHERE FROM 2K TO 3K AGL. FINALLY...HEAVY RAIN IS A CONCERN WITH
PWATS CLIMBING TO OVER 1 INCH HERE AT CHEYENNE AND 1.4 INCHES OUT
BY SIDNEY. STORM MOTIONS ARE FAIRLY SLOW...GENERALLY OUT OF THE
WEST AT LESS THAN 10KTS...SO WE COULD BE LOOKING AT A FLASH FLOOD
THREAT AS WELL IN AREAS THAT SEE TRAINING STORMS. STORMS SHOULD
CONTINUE INTO THE MID TO LATE EVENING HOURS...SPREADING INTO THE
PANHANDLE BY 6 PM OR SO TONIGHT.
FOR SUNDAY...MODELS INDICATING A REPEAT OF TODAYS WEATHER WITH
POSSIBLY CONVECTION FURTHER EAST INTO THE PANHANDLE INITIALLY.
SEVERE THUNDERSTORMS LOOK MORE OUT OVER THE PANHANDLE SUNDAY VS
INITIATING HERE IN SOUTHEAST WYOMING.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM MDT SAT AUG 3 2013
MAIN FORECAST CONCERN THROUGH NEXT WEEK WILL BE A STRONG MID
SUMMER COLD FRONT PUSHING ACROSS THE GREAT PLAINS AND INTO THE
FORECAST AREA...AS THE DEEP 543DM UPPER LEVEL LOW SETTLES OVER
SOUTHERN CANADA NEAR THE GREAT LAKES REGION. THIS IS PRETTY
UNUSUAL FOR THIS TIME OF THE YEAR...ALTHOUGH THE ROCKY MOUNTAIN
REGION WILL NOT SEE THE MAJORITY OF THIS COOLER AIR. MODELS SHOW
THIS FRONT QUICKLY MOVING ACROSS THE AREA TUESDAY AND TUESDAY
EVENING WITH HIGH TEMPERATURES AROUND 10 TO 15 DEGREES COOLER ON
WEDNESDAY AND THURSDAY. WITH SUBTROPICAL MONSOON MOISTURE IN
PLACE...A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IS ANTICIPATED
ACROSS MOST OF THE FORECAST AREA. THE BEST CHANCE WILL REMAIN OVER
THE MOUNTAINS AND ALONG/EAST OF THE LARAMIE RANGE...PRIMARILY FROM
MID AFTERNOON THROUGH EARLY IN THE EVENING. SOME OF THESE SHOWERS
MAY CONTINUE INTO THE OVERNIGHT HOURS...ESPECIALLY WEDNESDAY AND
THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 00Z TAF ISSUANCE)
SHOWERS AND TSTORMS WILL CONTINUE OVER SOUTHEAST WYOMING. LOW
CONFIDENCE IN TSTORMS ACROSS WESTERN NEBRASKA DUE TO ONGOING FOG AND
LOW CIGS...SO TOOK VCTS OUT OF MOST WESTERN NEBRASKA TERMINALS OR
STARTED VCTS LATER THIS EVENING. STORMS THAT OCCUR NEAR THE WY/NE
BORDER ARE CAPABLE OF PRODUCING LARGE HAIL AS WELL. TSTORMS WILL
DISSIPATE LATE TONIGHT...BUT WITH MOIST SOUTHERLY FLOW REMAINING
OVER THE AREA EXPECT PATCHY FOG AND LOW CIGS BELOW 1K FEET AGL TO
CONTINUE ACROSS THE HIGH PLAINS INTO WESTERN NEBRASKA THROUGH
TONIGHT.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT SAT AUG 3 2013
LIGHT WINDS AND MONSOONAL MOISTURE SHOULD KEEP FIRE WEATHER ISSUES
AT BAY FOR TODAY AND SUNDAY. AREAS EAST OF THE LARAMIE RANGE
SHOULD SEE CONTINUED GOOD CHANCES AT WETTING RAINS...HIGH
HUMIDITIES AND EASTERLY UPSLOPING WINDS. AREAS WEST WILL SEE DRIER
CONDITIONS WITH AFTERNOON HUMIDITIES FALLING INTO MID TEENS.
FORTUNATELY...WINDS SHOULD STAY LIGHT OUT THAT WAY KEEPING FIRE
WEATHER CONCERNS MINIMAL. BY MONDAY...SURFACE HIGH PRESSURE MOVING
INTO NORTH CENTRAL COLORADO WILL RE-ESTABLISH WESTERLY WINDS WITH
DRIER AIR FILTERING IN TO AREAS EAST OF THE LARAMIE RANGE. WINDS
WILL REMAIN LIGHT THOUGH...WHICH WILL KEEP FIRE WEATHER MINIMIZED.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...WEILAND
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1129 PM MDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 959 PM MDT SAT AUG 3 2013
UPDATED FOR EXPIRATION OF SEVERE TSTM WATCH. ALSO TO REFLECT
CURRENT PCPN TRENDS. WILL LEAVE FLASH FLOOD WATCH IN PLACE FOR EL
PASO COUNTY BECAUSE SOME MODERATE TO HEAVY RAIN IS CONTINUING OVER
PORTIONS OF SOUTHERN/SOUTHEAST EL PASO COUNTY.
UPDATE ISSUED AT 900 PM MDT SAT AUG 3 2013
UPDATED TO CANCEL FLASH FLOOD WATCH FOR TELLER COUNTY/RAMPART
RANGE...TO CANCEL SEVERE TSTM WATCH FOR TELLER COUNTY/PIKES PEAK
AREA AS WELL. ALSO UPDATED TO REFLECT CURRENT PCPN TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...FLASH FLOODING THREAT FOR THE BURN SCARS AND SEVERE THUNDERSTORM
THREAT FOR THE SOUTHEAST PLAINS THROUGH THIS EVENING...
RICH LOW LEVEL MOISTURE IN PLACE ACROSS SOUTHEAST PLAINS AS OF EARLY
THIS AFTERNOON...WITH SFC DEW POINTS IN THE 60S. THIS IS BEING
ADVECTED IN BY LOW LEVEL EASTERLY FLOW. CLOUD COVER HAS HUNG IN
LONGER ACROSS THE PLAINS THIS AFTERNOON BUT IS ERODING ON WESTWARD
EDGE WHICH SHOULD ERODE CIN FROM WEST TO EAST AS THE AFTERNOON
PROGRESSES. MEANWHILE...MONSOON PLUME CONTINUES TO LAY ACROSS THE
REGION CAUGHT UP IN SOUTHWEST FLOW AROUND WEST SIDE OF SFC HIGH AND
SFC DEW POINT ACROSS THE MOUNTAINS ARE QUITE RESPECTABLE...IN THE
40S WITH SOME LOWER 30S ACROSS INTERIOR VALLEY OF LAKE/CHAFFEE
COUNTIES.
FOR THE REMAINDER OF THIS AFTERNOON AND EVENING...THUNDERSTORMS OVER
THE MOUNTAINS WILL SPREAD EASTWARD ACROSS THE ADJACENT PLAINS WITH
MODELS SUGGESTING ONE OR MORE THUNDERSTORM COMPLEXES TAKING SHAPE
AROUND 03Z BEFORE DROPPING TO THE SOUTHEAST INTO SOUTHWEST KS AND
TX/OK PANHANDLES TOWARDS MORNING. SPC MESO ANALYSIS AS OF 18Z
SHOWING 2000+ J/KG OF CAPE. 0-6KM SHEARS WILL BE RUNNING AROUND
30-35 KTS OF DEEP LAYER SHEAR. THUS...MULTICELL STORMS WILL PROBABLY
BE THE MAIN STORM THREAT...THOUGH COULD NOT RULE OUT AN ISOLATED
SUPERCELL ESPECIALLY WHERE LOW LEVEL EASTERLIES MAXIMIZE. THIS
WOULD MOST LIKELY OCCUR ACROSS NORTHERN SECTIONS OF THE FORECAST
AREA...PARTICULARLY KIOWA COUNTY.
OF POTENTIALLY EQUAL OR GREATER CONCERN WILL BE POTENTIAL FOR FLASH
FLOODING ON THE BURN SCARS...PARTICULARLY WALDO AND BLACK FOREST.
SOUTHEAST UPSLOPE FLOW COMBINED WITH HEATING...AND WEAK SHORTWAVE
ENERGY EMBEDDED IN MONSOON PLUME ALOFT SHOULD TRIGGER THUNDERSTORMS
OVER THE PIKES PEAK REGION THROUGH 2 PM...WITH A LINE OF
THUNDERSTORMS MOVING OFF TO THE EAST ACROSS THE WALDO AND BLACK
FOREST BURN SCARS BETWEEN 3 AND 6 PM. A MYRIAD OF SHORT RANGE HIGH
RES MODELS SHOW THIS...THOUGH WITH VARYING TIMING. OF COURSE...HAVE
SEEN THIS BEFORE IN THE MODELS AND HAD STORMS MIRACULOUSLY SPARE THE
BURN SCARS...BUT DEW POINTS SO HIGH (40S AND 50S) THREAT SHOULD BE
FAIRLY HIGH TODAY. FLASH FLOOD WATCH STILL LOOKS ON TRACK. THINK
THREAT SHOULD DIMINISH AFTER 8 PM...BUT HRRR OCCASIONALLY SHOWS
ANOTHER ROUND MOVING OFF AROUND 04Z SO WILL MAINTAIN THE MIDNIGHT
END TIME OF THE WATCH FOR NOW. FREQUENTLY THE HRRR OVERESTIMATES
THE INTENSITY OF ANY TRAILING ROUNDS OF CONVECTION.
THE WEST FORK BURN SCAR IS ALSO UNDER THE GUN TODAY FOR FLASH
FLOODING...THOUGH THREAT DOES NOT LOOK AS HIGH AS YESTERDAY. WITH
PRECIP WATERS RUNNING AROUND 150% OF NORMAL ACROSS THE WESTERN
PORTIONS OF CO...HEAVY RAIN WILL BE A THREAT WITH ANY THUNDERSTORMS
WHICH COULD CAUSE FLASH FLOODING SHOULD IT IMPACT THE WEST FORK BURN
SCAR. SO WILL BE MONITORING THIS REGION AS WELL.
OVERNIGHT...ACTIVITY SHOULD SHIFT EASTWARD AND EXIT THE AREA WITH
STRATUS SPREADING/DEVELOPING ACROSS SOUTHEAST COLORADO OVERNIGHT.
SUNDAY WILL BE HUMID AGAIN ACROSS THE SOUTHEAST PLAINS WITH DEW
POINTS IN THE 50S AND 60S IN THE MORNING AND MONSOON PLUME STILL
OVER THE REGION. MODELS SUGGEST LESS CONVECTION TOMORROW...AND EVEN
DRY SFC DEW POINTS ACROSS THE SOUTHEAST MTS A LITTLE IN THE
AFTERNOON STILL LOOKING AT CAPES AROUND 1500 J/KG ACROSS THE FAR
EAST PLAINS AND WITH MONSOON PLUME STILL OVERHEAD...AT LEAST THE
TYPICAL SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. BURN SCARS
WILL BE UNDER THE GUN AGAIN AS USUAL...BUT THREAT APPEARS A LITTLE
LOWER THAN TODAY...SO WILL NOT HOIST ANY WATCHES AT THIS TIME.
LATER SHIFTS CAN GET A LOOK AT THE LATEST RUNS AND REASSESS.
OTHERWISE...TEMPERATURES TOMORROW SHOULD SKEW SLIGHTLY WARMER THAN
THOSE OF TODAY.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 249 PM MDT SAT AUG 3 2013
...SEASONAL MONSOON WILL REMAIN IN PLACE THROUGH NEXT WEEK...
MOIST PATTERN WILL CONTINUE. SOUTHWEST MONSOON WILL CONTINUE TO
TAKE AIM AT SOUTHERN COLORADO THROUGH MOST OF NEXT WEEK.
ADDITIONALLY...A LARGE UPPER TROUGH OVER THE NORTHERN SOUTHERN
CANADA AND THE NORTHERN TIER OF THE US...WILL SEND SURFACE
BOUNDARIES SOUTH THROUGH THE CENTRAL PLAINS AT TIMES...BACKING
THE MOISTURE UP AGAINST THE MOUNTAINS. THIS PATTERN SHOULD KEEP
PLENTY OF LOW LEVEL MOISTURE IN PLACE ACROSS THE PLAINS AND EAST
SLOPES OF THE MOUNTAINS. ALSO...PERIODS OF ENHANCED UPSLOPE FLOW
BEHIND THE BOUNDARIES WILL HELP TO LIFT THE AIR AND SQUEEZE OUT THE
PRECIPITATION ON A MORE WIDESPREAD BASIS ACROSS THE AREA. SO...ALL
SEEMS IN PLACE FOR A RATHER WET PERIOD ACROSS SOUTHERN
COLORADO...WITH PERIODS OF HEAVY RAIN AND FLASH FLOODING POSSIBLE
EACH DAY OF NEXT WEEK. SPECIFICS OF THE FORECAST ARE DIFFICULT BUT
INDICATIONS ARE THAT WE COULD SEE CONVECTIVE COMPLEXES AFFECTING THE
PLAINS MONDAY AND TUESDAY NIGHTS...A MORE WIDESPREAD AREA OF
PRECIPITATION WEDNESDAY INTO THURSDAY...AND THEN MORE SCATTERED
PRECIPITATION AGAIN FRIDAY INTO SATURDAY. ALL OF THESE DETAILS
ARE SUBJECT TO CHANGE. STAY TUNED. LW
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1125 PM MDT SAT AUG 3 2013
WITH ALL THE RAIN THAT FELL IN THE KCOS AND KPUB AREAS
TONIGHT...EXPECTING STRATUS AND POSSIBLY SOME FOG...RESULTING IN
MVFR OR IFR CONDITIONS THAT SHOULD END BY MIDMORNING SUNDAY.
EXPECTING KALS TO HAVE VFR CONDITIONS TONIGHT. THUNDERSTORMS WILL
ONCE AGAIN DEVELOP OVER THE MOUNTAINS ON SUNDAY AND MOVE OVER THE
LOWER ELEVATIONS FOR THE AFTERNOON AND EVENING HOURS. THUS ALL
THREE TERMINAL SITES WILL HAVE THE CHANCE FOR TSTMS.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
FLASH FLOOD WATCH UNTIL MIDNIGHT MDT TONIGHT FOR COZ084-085.
&&
$$
UPDATE...28
SHORT TERM...KT
LONG TERM...LW
AVIATION...28
AREA FORECAST DISCUSSION
NWS MIAMI FL
138 AM EDT SUN AUG 4 2013
.AVIATION...CALM WINDS EARLY WILL BECOME W-SW AT AROUND 5 KT THIS
MORNING BEFORE A SEA BREEZE DEVELOPS ALONG THE ATLANTIC COAST WITH
SE WINDS 5-10 KT EXPECTED IN THE AFTERNOON. SCATTERED TSTORMS ARE
EXPECTED DURING THE AFTERNOON, SO CONTINUED WITH VCTS ALL
TERMINALS THEN. THE TSTORMS WILL BE MOST FOCUSED INTERIOR/EAST
COAST LATE IN THE AFTERNOON. BRIEF IFR AND GUSTY WINDS IS
POSSIBLE WITH ANY DIRECT TSTORM IMPACTS. /GREGORIA
&&
.PREV DISCUSSION... /ISSUED 745 PM EDT SAT AUG 3 2013/
AVIATION...
ONLY LIGHT TO MODERATE SHRAS REMAIN ACROSS MAINLY THE LAKE
OKEECHOBEE REGION THIS EVENING. LATEST HRRR AND LOCAL SHORT RANGE
MODELS SHOW THIS ACTIVITY DIMINISHING IN COVERAGE OVER THE NEXT
FEW HOURS. THEREFORE DID NOT PREVAIL ANY PRECIPITATION AT ANY
SITE OVERNIGHT...ALTHOUGH COULD NOT RULE OUT AN ISOLATED BRIEF
SHRA AT ANY SITE THROUGH THE REMAINDER OF THIS EVENING.
OTHERWISE...WINDS ARE EXPECTED TO BE NEARLY CALM THROUGH THE NIGHT
AND MAINLY LIGHT OUT OF THE SOUTHWEST DURING THE DAY SUNDAY...WITH
A WEAK EAST COAST SEA BREEZE DEVELOPING BY EARLY AFTERNOON.
PREV DISCUSSION... /ISSUED 725 PM EDT SAT AUG 3 2013/
UPDATE...
THUNDERSTORM ACTIVITY HAS DIMINISHED ACROSS SOUTH FLORIDA,
HOWEVER, THERE STILL ARE SOME SHOWERS IN THE AREA ESPECIALLY
ACROSS THE NORTHERN AREAS. THESE SHOWERS WILL LINGER THROUGH THE
EVENING HOURS BEFORE DIMINISHING. A LIGHT SOUTHWESTERLY STEERING
FLOW WILL CONTINUE THROUGH THE REST OF THE WEEKEND. SCATTERED
SHOWERS AND THUNDERSTORMS WILL REDEVELOP TOMORROW AFTERNOON AND
EVENING ESPECIALLY ACROSS INTERIOR AND EAST COAST SECTIONS. A DEEP
LAYER RIDGE WILL BUILD BACK INTO THE REGION BY THE MIDDLE OF NEXT
WEEK. THIS WILL ALLOW FOR EASTERLY FLOW TO RETURN WHICH WILL FOCUS
THE SHOWER AND THUNDERSTORM DEVELOPMENT ACROSS INTERIOR AND WEST
COAST SECTIONS.
PREV DISCUSSION... /ISSUED 210 PM EDT SAT AUG 3 2013/
SHORT TERM (TONIGHT-MONDAY NIGHT)...
GLOBAL MODELS INITIALIZED QUITE WELL THIS MORNING SHOWING THE WEAK
SURFACE CIRCULATION ASSOCIATED WITH T.D. DORIAN LOCATED OFF THE
NORTHEAST FLORIDA PENINSULA COAST AND A WEAK MID LEVEL TROUGH WHICH
WAS LOCATED JUST EAST OF MLB. A TROUGH BOUNDARY EXTENDS SOUTHWEST OF
THIS FEATURE ACROSS SOUTH FLORIDA AND ALL OF THIS HAD EARLIER HELPED
ENHANCE A LARGE CLUSTER OF CONVECTION ACROSS THE ATLANTIC WATERS
MOSTLY NORTH OF OUR AREA ALONG WITH DIURNAL CYCLE ACTIVITY ACROSS
THE MAINLAND. THE CONVECTION OVER THE WATERS HAS BEGUN TO DIMINISH
AT THIS POINT. THE MODELS ARE ALSO IN GOOD AGREEMENT THAT A DIGGING
MID LEVEL TROUGH INTO THE EASTERN U.S. WILL PUSH A COLD FRONT INTO
THE SOUTHEAST STATES THIS EVENING WHICH WILL PICK UP DORIAN AND LIFT
IT TO THE NORTHEAST BECOMING ABSORBED INTO THE MAIN TROUGH. AT THE
SAME TIME, THE WEAK TROUGH BOUNDARY ACROSS SOUTH FLORIDA WILL ALSO
LIFT TO THE NORTHEAST THIS EVENING SO THE CONVECTION THIS AFTERNOON
DEVELOPING MOSTLY DUE TO THE INFLUENCE OF THE TROUGH AND DIURNAL
HEATING WILL DIMINISH RAPIDLY AFTER SUNSET.
SOUTH FLORIDA WILL THEN ENTER A STAGNANT WEATHER PATTERN FOR THE
REMAINDER OF THIS PERIOD. THE LOW LEVEL RIDGE WILL REMAIN ACROSS THE
FLORIDA STRAITS AS A LARGE MID LEVEL TROUGH MOVES LITTLE ACROSS THE
EASTERN STATES AND A STRONG MID LEVEL RIDGE CENTERED OVER TEXAS WILL
BUILD EAST INTO THE EASTERN GULF OF MEXICO AND THE FLORIDA
PENINSULA. THIS WILL YIELD A WESTERLY STEERING FLOW WITH A
NORTHERLY FLOW IN THE UPPER LEVELS OF THE ATMOSPHERE WHILE
MAINTAINING PWAT OF AROUND TWO INCHES OR SLIGHTLY LESS AND VERY
LITTLE CHANGE TO THE 500MB TEMPERATURES WHICH WILL RUN AROUND -6
CELSIUS. THIS IS RIGHT AT THE NORMAL VALUES FOR EARLY AUGUST. SO
POPS WILL AVERAGE CLOSE TO AUGUST AVERAGES BUT WITH THE HIGHEST
CHANCES OF RAINFALL OVER THE INTERIOR AND EAST COAST METRO AREAS.
FORECAST SOUNDINGS SHOW THE PRIMARY THREAT WILL BE AFTERNOON
THUNDERSTORMS WITH THE CAPABILITY OF PRODUCING SOME ISOLATED STRONG
WIND GUSTS AND THE TYPICAL BRIEF HEAVY DOWNPOURS ALONG WITH FREQUENT
LIGHTNING STRIKES.
LONG TERM (TUESDAY-SATURDAY)...
TUESDAY WILL BE A TRANSITIONAL DAY AS IT APPEARS NOW WITH THE LARGE
SCALE TROUGH OVER THE EAST LIFTING TO THE EAST WHICH WILL ALLOW FOR
A DEEP LAYER RIDGE TO BUILD ACROSS NORTH FLORIDA. SO AS THIS BEGINS
TO OCCUR, THE CONVECTION WILL BE MOSTLY DRIVEN BY SEA BREEZE
BOUNDARIES ON TUESDAY. THEN, AS THE RIDGE BECOMES FIRMLY DEVELOPED
BY WEDNESDAY THROUGH THE REMAINDER OF THE WEEK AND INTO NEXT WEEKEND
THE HIGHEST CHANCES FOR RAIN WILL REVERT TO THE INTERIOR AND
SOUTHWEST COAST. OF COURSE, THERE IS ALWAYS GREATER UNCERTAINTY BY
DAYS 6 AND 7 SO WILL MAINTAIN A BROAD BRUSH CHANCE OF THUNDERSTORMS
FOR ALL AREAS AND WILL ADJUST AS THE FORECAST BECOMES MORE FINE
TUNED.
MARINE...
DUE TO A SOUTHWEST WIND, SEAS WILL BE TRANQUIL THROUGH EARLY NEXT
WEEK OUTSIDE OF STRONGER THUNDERSTORMS WHICH COULD MAKE FOR
HAZARDOUS LOCAL SEAS IN GUSTY WINDS. THE WIND WILL BECOME EAST AT
MOSTLY LESS THAN 15 KNOTS BY LATE TUESDAY THROUGH THE MIDDLE OF
NEXT WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 79 92 79 91 / 10 50 20 30
FORT LAUDERDALE 78 89 78 90 / 10 50 20 30
MIAMI 78 91 78 91 / 10 50 20 30
NAPLES 77 90 77 90 / 10 40 10 40
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
407 AM EDT SUN AUG 4 2013
.SYNOPSIS...
THE RETURN OF HIGH PRESSURE WILL BRING MAINLY DRY CONDITIONS FOR
TODAY. MOISTURE WILL INCREASE MONDAY...BRINGING ANOTHER CHANCE OF
SHOWERS AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THIS MORNING...A SHORT WAVE MOVE THROUGH OVERNIGHT BRINGING DRIER
AIR TO THE REGION. A WEAK COLD FRONT WAS IN THE PROCESS OF MOVING
THROUGH THE REGION THIS MORNING AND SHOULD MOVE TO THE SOUTH AND
EAST OF THE FORECAST AREA LATER THIS MORNING. OUR FORECAST REMAINS
DRY THIS MORNING WITH LOWS IN THE LOWER 70S.
TODAY...WEAK HIGH PRESSURE WILL BUILD IN WITH DRY WEATHER EXPECTED.
FORECAST SOUNDINGS INDICATE ATMOSPHERE NOT QUITE AS DRY AND CAPPED
AS IN RECENT DAYS. LFC FAIRLY HIGH. MODERATE INSTABILITIES PROJECTED.
IT APPEARS CONVECTION WILL BE FOCUSED MAINLY ALONG THE WEAKENING
FRONTAL BOUNDARY MAINLY TO THE SOUTH OF THE FORECAST AREA AND ALSO
IN THE COASTAL PLAIN. SOME MODEL DISCREPANCY ON LOCATION...BUT
GENERAL MODEL CONSENSUS FAVORS THE SOUTHERN FA AND COASTAL PLAIN
THIS AFTN/EVE. ANY TSRA THAT FORM COULD PRODUCE STG WND GUSTS DUE
TO DRY AIR ALOFT.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
SUNDAY NIGHT...THE FRONT WILL BE SETTLING OVER SOUTHERN GA AS THE
HIGH PRESSURE TRACKS NORTH OF THE FORECAST AREA. THIS WILL PUT THE
AREA UNDER NORTHEASTERLY FLOW. WINDS ALOFT WILL BE NORTHWESTERLY
ALLOWING FOR DOWNSLOPING AND DRYING. WILL CONTINUE POPS LESS THAN
10 PERCENT. OVERNIGHT LOWS IN THE UPPER 60S TO LOWER 70S.
MONDAY AND MONDAY NIGHT...HIGH PRESSURE WILL BEGIN SLIDING EAST OF
THE AREA WITH MOISTURE RETURNING AS FLOW TURNS SOUTHEASTERLY. MID
AND UPPER LEVEL FLOW WILL REMAIN NORTHWESTERLY WHICH WILL KEEP
DRIER AIR IN THE MID AND UPPER LEVELS THROUGH THE DAY LIMITING
CONVECTIVE POTENTIAL. BEST CHANCE OF CONVECTION WILL BE OVER THE
SOUTHERN MIDLANDS AND CSRA WHERE MOISTURE WILL BE A BIT MORE
PLENTIFUL. RAIN CHANCES WILL CONTINUE THROUGH MONDAY NIGHT AS AN
UPPER LEVEL SHORT WAVE MOVES INTO THE AREA. HIGH TEMPERATURES
MONDAY AFTERNOON WILL BE IN THE UPPER 80S TO LOWER 90S WITH LOWS
MONDAY NIGHT IN THE LOWER 70S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
UPPER LEVEL PATTERN WILL BE SLOW TO PROGRESS THROUGH THE LONG TERM
AS A BLOCKING PATTERN REMAINS STRETCHED FROM AK THROUGH THE CANADIAN
PROVINCES. THIS WILL KEEP AN UPPER LEVEL LOW NEAR HUDSON BAY WITH
THE CORRESPONDING TROUGH OVER THE EASTERN US. UPPER RIDGE TO THE
SOUTH AND WEST TRIES TO BUILD TOWARD THE REGION LATE IN THE PERIOD
FRIDAY AND SATURDAY BUT WILL MEET A LOT OF RESISTANCE FROM THE
EASTERN CONUS TROUGH WHICH REMAINS FAIRLY STRONG. THIS WILL KEEP
AN ACTIVE WEATHER PATTERN OVER THE AREA AS A FRONTAL BOUNDARY
STALLS OVER THE REGION WEDNESDAY THROUGH THE END OF THE LONG TERM.
THIS WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE
FORECAST WITH INCREASING CHANCES DURING THE LATTER HALF OF THE
LONG TERM. TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY
BELOW TO NEAR NORMAL FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR
NORMAL.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
LATEST LAPS SOUNDINGS INDICATE LOW LEVEL MOISTURE HAS BECOME
SHALLOW. SATL INDICATES UPPER LEVEL CLOUDINESS STREAMING ACROSS THE
REGION. NAM BUFKIT INDICATES BOUNDARY LAYER WINDS STAYING UP AROUND
20 KT AND VEERING TO WNW AS A WEAK SURFACE TROUGH COMES THROUGH.
THESE FACTORS...PLUS LACK OF CONVECTION AND RAIN COOLED AIR SATURDAY
ALSO LIMITS FOG THREAT. LATEST HRRR CONFINES ANY STRATUS/FOG
PROJECTIONS TO THE CSRA....WHILE LATEST RAP AND GFS LAMP MORE
OPTIMISTIC. FOR NOW...WILL RESTRICT ANY FOG MENTION TO FOG PRONE
AGS/OGB...KEEPING IT MVFR AT OGB...AND IFR AT AGS.
AFTER ANY LATE NIGHT/EARLY MORNING RESTRICTIONS...VFR EXPECTED.
SURFACE TROUGH WILL PUSH SOUTH TODAY. GFS FORECAST SOUNDINGS
INDICATE ATMOSPHERE NOT QUITE AS DRY AND CAPPED AS IN RECENT DAYS.
IT APPEARS AFTN/EVE CONVECTIVE ACTIVITY WILL BE CONFINED TO A
SURFACE TROUGH MAINLY NEAR THE COASTAL PLAIN...AND POSSIBLY OUR
SOUTHERN FA. CONVECTIVE CHANCES TOO LOW TO INCLUDE TS MENTION IN THE
TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN AFTERNOON
CONVECTION AS WELL AS LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
124 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A WEAK COLD FRONT WILL CROSS THE AREA OVERNIGHT. THE RETURN OF
HIGH PRESSURE WILL BRING MAINLY DRY CONDITIONS FOR SUNDAY.
MOISTURE WILL INCREASE MONDAY...BRINGING ANOTHER CHANCE OF SHOWERS
AND THUNDERSTORMS.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
HIGH CLOUDS BLANKETED THE AREA THIS EVENING. AN UPPER TROUGH WAS
MOVING OFF THE COAST PROVIDING NORTHWEST FLOW ALOFT FOR OUR AREA.
A COLD FRONT EXTENDING ACROSS THE CENTRAL APPALACHIANS INTO
WESTERN TN WILL MOVE INTO THE CAROLINAS LATE TONIGHT. NO
SIGNIFICANT SHORT WAVES ARE FORECAST TO AFFECT AREA. GUIDANCE
AGREE ON LITTLE...IF ANY...PRECIP AS THE FRONT WILL ARRIVE AT AN
UNFAVORABLE TIME FOR CONVECTION. OUR FORECAST REMAINS DRY
OVERNIGHT WITH LOWS IN THE LOWER 70S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH MONDAY NIGHT/...
SUNDAY AND SUNDAY NIGHT...WEAK FRONTAL BOUNDARY WILL HAVE CROSSED
THE AREA BY DAYBREAK WITH WEAK HIGH PRESSURE IN CONTROL OF THE AREA
THROUGH THE DAY. BY EVENING THE FRONT WILL BE SETTLING OVER SOUTHERN
GA AS THE HIGH PRESSURE TRACKS NORTH OF THE FORECAST AREA. THIS WILL
PUT THE AREA UNDER NORTHERLY FLOW SUNDAY WITH NORTHEASTERLY FLOW
SUNDAY NIGHT. WINDS ALOFT WILL BE NORTHWESTERLY ALLOWING FOR
DOWNSLOPING AND DRYING. AS SUCH HAVE REMOVED POPS FOR SUNDAY AND
SUNDAY NIGHT. AFTERNOON HIGH TEMPERATURES WILL BE IN THE LOWER TO
MIDDLE 90S WITH OVERNIGHT LOWS IN THE LOWER 70S.
MONDAY AND MONDAY NIGHT...HIGH PRESSURE WILL BEGIN SLIDING EAST OF
THE AREA WITH MOISTURE RETURNING AS FLOW TURNS SOUTHEASTERLY. MID
AND UPPER LEVEL FLOW WILL REMAIN NORTHWESTERLY WHICH WILL KEEP
DRIER AIR IN THE MID AND UPPER LEVELS THROUGH THE DAY LIMITING
CONVECTIVE POTENTIAL. BEST CHANCE OF CONVECTION WILL BE OVER THE
SOUTHERN MIDLANDS AND CSRA WHERE MOISTURE WILL BE A BIT MORE
PLENTIFUL. RAIN CHANCES WILL CONTINUE THROUGH MONDAY NIGHT AS AN
UPPER LEVEL SHORT WAVE MOVES INTO THE AREA. HIGH TEMPERATURES
MONDAY AFTERNOON WILL BE IN THE UPPER 80S TO LOWER 90S WITH LOWS
MONDAY NIGHT IN THE LOWER 70S.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
UPPER LEVEL PATTERN WILL BE SLOW TO PROGRESS THROUGH THE LONG TERM
AS A BLOCKING PATTERN REMAINS STRETCHED FROM AK THROUGH THE CANADIAN
PROVINCES. THIS WILL KEEP AN UPPER LEVEL LOW NEAR HUDSON BAY WITH
THE CORRESPONDING TROUGH OVER THE EASTERN US. THIS WILL KEEP AN
ACTIVE WEATHER PATTERN OVER THE AREA AS A FRONTAL BOUNDARY STALLS
OVER THE REGION WEDNESDAY THROUGH THE END OF THE LONG TERM. THIS
WILL KEEP CHANCES OF SHOWERS AND THUNDERSTORMS IN THE FORECAST
WITH INCREASING CHANCES DURING THE LATTER HALF OF THE LONG TERM.
TEMPERATURES THROUGH THE LONG TERM WILL BE SLIGHTLY BELOW TO NEAR
NORMAL FOR DAYTIME HIGHS WITH OVERNIGHT LOWS NEAR NORMAL.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
LATEST LAPS SOUNDINGS INDICATE LOW LEVEL MOISTURE HAS BECOME
SHALLOW. SATL INDICATES UPPER LEVEL CLOUDINESS STREAMING ACROSS THE
REGION. NAM BUFKIT INDICATES BOUNDARY LAYER WINDS STAYING UP AROUND
20 KT AND VEERING TO WNW AS A WEAK SURFACE TROUGH COMES THROUGH.
THESE FACTORS...PLUS LACK OF CONVECTION AND RAIN COOLED AIR SATURDAY
ALSO LIMITS FOG THREAT. LATEST HRRR CONFINES ANY STRATUS/FOG
PROJECTIONS TO THE CSRA....WHILE LATEST RAP AND GFS LAMP MORE
OPTIMISITIC. FOR NOW...WILL RESTRICT ANY FOG MENTION TO FOG PRONE
AGS/OGB...KEEPING IT MVFR AT OGB...AND IFR AT AGS.
AFTER ANY LATE NIGHT/EARLY MORNING RESTRICTIONS...VFR EXPECTED.
SURFACE TROUGH WILL PUSH SOUTH TODAY. GFS FORECAST SOUNDINGS
INDICATE ATMOSPHERE NOT QUITE AS DRY AND CAPPED AS IN RECENT DAYS.
IT APPEARS AFTN/EVE CONVECTIVE ACTIVITY WILL BE CONFINED TO A
SURFACE TROUGH MAINLY NEAR THE COASTAL PLAIN...AND POSSIBLY OUR
SOUTHERN FA. CONVECTIVE CHANCES TOO LOW TO INCLUDE TS MENTION IN THE
TAFS AT THIS TIME.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE IN AFTERNOON
CONVECTION AS WELL AS LATE NIGHT/EARLY MORNING FOG/STRATUS.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
520 AM EDT SUN AUG 4 2013
.SYNOPSIS...
AFTER A FEW MORNING SHOWERS...DRY AND COOL WEATHER CAN BE EXPECTED FOR THE
START OF THE NEW WEEK AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY
REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
NR DAWN UPDATE WAS ISSUED TO ADJUST FOR HOURLY TRENDS OF TEMP AND
PCPN PROBABILITY.
FEW SHOWERS THAT HAVE FORMED N OF I 80 ALNG A SFC TROF/WEAK
SECONDARY FRONT HAVE SAGGED SWD THIS MRNG TWD THE METRO AREA.
SLGT TO CHC POPS WERE THUS MAINTAINED PAST DAWN IN ACCORDANCE
WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /09Z SUNDAY THROUGH THURSDAY/...
IFR FOG IN THE SOUTH TO BEGIN THE FORECAST. ELSEWHERE GENERAL VFR
WITH MID-DECK AND AN ISO NON-RESTRICTIVE SHOWER.
VFR FORECAST FOR ALL PORTS SHORTLY AFTER DAWN WITH BKN-OVC CU
EXPECTED THROUGH THE REST OF THE DAY.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NO WIDESPREAD IFR
WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED BY TUESDAY
NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY NIGHT
THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
323 AM EDT SUN AUG 4 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE START OF THE NEW WEEK
AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
FEW SHOWERS HAVE FORMED ALNG/N OF I 80 AS CROSSING SHRTWV HAS
IGNITED A SFC TROF/WEAK SECONDARY FRONT MOVG OFF LAKE ERIE.
SLGT TO CHC POPS WERE THUS INTRODUCED FOR THE MRNG OVR AREAS N OF
PIT...IN ACCORDANCE WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
QUESTION OVERNIGHT...WHERE TO PLACE RESTRICTIONS WITH FOG AND HOW
LOW TO GO WITH RESTRICTIONS. USING A COMBINATION OF CURRENT
CONDITIONS... FORECAST SOUNDINGS AND BUFKIT DATA...HAVE DECIDED TO
INCLUDE THE FOG AT ALL PORTS EXCEPT PIT...AGC AND BVI. WITH THE
EXCEPTION OF ZZV AND HLG...WILL GO WITH MVFR RESTRICTIONS
TEMPORARILY LOWERING TO IFR. AT THE PREVIOUS 2 PORTS HAVE DECIDED
ON A TEMPO GROUP OF MVFR. CURRENTLY MGW HAS GONE LIFR...WHICH
FALLS IN LINE WITH SURROUNDING PORTS IN NORTHERN WV. WILL LEAVE
THEM AT LIFR FOR THE REST OF THE NIGHT.
CONTINUING TO RELY ON THE FORECAST SOUNDINGS...ALL PORTS SHOULD SEE
BKN-OVC CU DEVELOP LATER THIS MORNING AND REMAIN THROUGH THE
FORECAST PERIOD. THE CU WILL BE IN THE VFR CAT.
HAVE LOWERED WINDS A BIT FROM PREVIOUS FORECAST...AS THE DEVELOPMENT
OF CU SHOULD PREVENT THE STRONGER WINDS ALOFT FROM MIXING DOWN.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NO WIDESPREAD IFR WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED
BY TUESDAY NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY
NIGHT THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/22
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
126 AM EDT SUN AUG 4 2013
.SYNOPSIS...
DRY AND COOL WEATHER CAN BE EXPECTED FOR THE START OF THE NEW WEEK
AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
FEW SHOWERS HAVE FORMED TO THE N OF I 80 AS CROSSING SHRTWV HAS
IGNITED A SFC TROF/WEAK SECONDARY FRONT MOVG OFF LAKE ERIE.
SLGT/ISOLD POPS HAVE THUS BEEN INTRODUCED FOR THE MRNG OVR AREAS N
OF PIT...IN ACCORDANCE WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
QUESTION OVERNIGHT...WHERE TO PLACE RESTRICTIONS WITH FOG AND HOW
LOW TO GO WITH RESTRICTIONS. USING A COMBINATION OF CURRENT
CONDITIONS... FORECAST SOUNDINGS AND BUFKIT DATA...HAVE DECIDED TO
INCLUDE THE FOG AT ALL PORTS EXCEPT PIT...AGC AND BVI. WITH THE
EXCEPTION OF ZZV AND HLG...WILL GO WITH MVFR RESTRICTIONS
TEMPORARILY LOWERING TO IFR. AT THE PREVIOUS 2 PORTS HAVE DECIDED
ON A TEMPO GROUP OF MVFR. CURRENTLY MGW HAS GONE LIFR...WHICH
FALLS IN LINE WITH SURROUNDING PORTS IN NORTHERN WV. WILL LEAVE
THEM AT LIFR FOR THE REST OF THE NIGHT.
CONTINUING TO RELY ON THE FORECAST SOUNDINGS...ALL PORTS SHOULD SEE
BKN-OVC CU DEVELOP LATER THIS MORNING AND REMAIN THROUGH THE
FORECAST PERIOD. THE CU WILL BE IN THE VFR CAT.
HAVE LOWERED WINDS A BIT FROM PREVIOUS FORECAST...AS THE DEVELOPMENT
OF CU SHOULD PREVENT THE STRONGER WINDS ALOFT FROM MIXING DOWN.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/...
NO WIDESPREAD IFR WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED
BY TUESDAY NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY
NIGHT THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
457 AM EDT SUN AUG 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN AUG 4 2013
NW FLOW ALOFT REMAINS IN PLACE BUT HEIGHTS ARE FLATTER ACROSS LK
SUPERIOR REGION COMPARED TO YESTERDAY. WV LOOP SHOWS RIBBON OF
DRYING WITH ENHANCED MOISTURE STAYING MOSTLY NORTH AND EAST OF
UPPER MICHIGAN. FLOW BECOMES MORE ZONAL FM PACIFIC NORTHWEST
THROUGH NORTHERN PLAINS INTO SOUTHERN PORTIONS OF ALBERTA AND
SASKATCHEWAN. MORE FORMIDABLE SHORTWAVE IS LOCATED HERE AND THAT
WAVE ALONG WITH SFC TROUGH AND ASSOCIATED WARM/MOIST ADVECTION IS
HELPING TO GENERATE CLUSTERS OF SHRA/TSRA FM SOUTHERN SASKATCHEWAN
THROUGH WESTERN DAKOTAS. THE SHORTWAVE AND SFC TROUGH APPROACH UPPER
LAKES REGION LATE TONIGHT AND COULD BRING SOME SHOWERS TO THE AREA.
MORE ON THAT LATER ON.
CURRENTLY OVER UPPER MICHIGAN...1026MB HIGH PRESSURE RIDGE CENTERED
OVER CENTRAL MINNESOTA IS TRYING TO RIDGE ACROSS WESTERN CWA. TEMPS
ARE AS COLD AS LOWER 40S THERE BUT ARE STILL INTO THE 50S ALONG LK
SUPERIOR AND OVER EASTERN HALF OF CWA. COOL/MOIST AIR AND LIGHT
WINDS OVER WEST RESULTING IN SOME FOG AS SEEN IN VSBY LESS THAN 3SM
AT IWD AND EGV THROUGH THE NIGHT. OTHERWISE...SKIES ARE MAINLY CLEAR
THOUGH STRATOCU IS HANGING TOUGH IN THE EAST CLOSER TO H9-H8 THERMAL
TROUGH. UPSTREAM SOUNDING AT CYPL SHOWED WELL MIXED LOWER BLYR WITH
SHALLOW LAYER OF MOISTURE AROUND 800MB/6KFT AND SUBSIDENCE INVERSION
BETWEEN H8-H7. CONVECTIVE TEMPS PRETTY LOW OVR CWA TODAY...MID-UPR
60S...SO THINK THIS MOISTURE WILL TURN INTO FAIRLY DECENT CU DECK BY
EARLY AFTN. SKIES COULD TURN MOSTLY CLOUDY FOR A TIME WHERE LAKE
BREEZE CONVERGENCE IS STRONGEST OVR CNTRL UPR MICHIGAN. GIVEN MORE
UNFAVORABLE LARGE SCALE SETUP FOR PRECIP WITH NO REAL SHORTWAVES
MOVING ACROSS AND WITH THERMAL TROUGHING EXITING THROUGH AFTN ALONG
WITH NOT AS MUCH MOISTURE DEPTH AS YESTERDAY...WILL GO WITH DRY
FORECAST TODAY. PER MODELED RADAR REFLECTIVITY ONLY THE LOCAL
RUM-WRF MODEL INDICATES POSSIBLY SEEING A SHRA WHILE HRRR SHOWS
LITTLE IN WAY OF SHRA DEVELOPMENT.
ATTN TONIGHT IS ON THE SHORTWAVE OVER SOUTHERN SASKATCHEWAN. EXPECT
THIS WAVE TO PUSH ACROSS NORTH DAKOTA THIS EVENING AND INTO NORTHEAST
MINNESOTA LATE TONIGHT. ANOTHER WAVE AND UPPER JETLET CURRENTLY
LIFTING ACROSS WESTERN MONTANA SLIDES TO CENTRAL MINNESOTA LATER
TONIGHT. SFC-H85 TROUGH WORKS EAST INTO MINNESOTA BY LATE TONIGHT.
MAINLY H7 MOISTURE ADVECTION AND FRONTOGENESIS AHEAD OF THE WAVES
ALONG WITH H85 TEMPERATURE ADVECTION WILL BE MAIN SUPPORT FOR SHRA
TONIGHT. A LOT OF TSRA CURRENTLY OVER DAKOTAS BUT EDGE OF 1-6KM
MUCAPE STAYS WELL TO THE SOUTHWEST OF UPR MICHIGAN TO NOT INCLUDE
TSRA. GFS/NAM/ECMWF/GEM IN GENERAL AGREEMENT ABOUT TONIGHT...BUT
NAM AND ASSOCIATED HIGHER RESOLUTION MODELS THAT ARE INITIALIZED OFF
OF IT...ARE MORE AGGRESSIVE WITH SHRA DEVELOPMENT OVER UPR MICHIGAN
OVERNIGHT TONIGHT. DO THINK H85-H6 MOISTURE ADVECTION/LIFT AND WARM
AIR ADVECTION AT H85 IS ENOUGH TO INCLUDE SLIGHT CHANCES WORKING
FROM WEST TO CENTRAL CWA. BUMPED POPS UP LATE TO LOWER CHANCE TOWARD
OVER FAR SW...VCNTY OF IWD AND IRON RIVER...WITH CLOSER PROXIMITY TO
LARGER SCALE WAVES MOVING INTO THE UPPER LAKES REGION. H7-H5 MOISTURE
SHOULD INCREASE STEADILY FM WEST TO EAST TONIGHT...WHICH WILL AFFECT
MIN TEMPS. COLD SPOT WILL BE INTERIOR EAST CWA /MID 40S MIN TEMPS/
AS LONGER PERIOD OF CLEAR SKIES/MINIMUM OF PWAT RESULTS IN BETTER
RADIATIONAL COOLING. TEMPS OVER FAR WEST WILL ONLY FALL INTO THE MID
50S WITH MORE CLOUD COVER AND INCREASING RETURN FLOW AHEAD OF SFC
TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM EDT SUN AUG 4 2013
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT ON THE BIG PICTURE THRU
THIS WEEK. IN THE MEAN...A TROF IS EXPECTED TO REMAIN IN PLACE
GENERALLY FROM HUDSON BAY VCNTY TO THE GREAT LAKES...NEW ENGLAND AND
SE CANADA. MAIN FEATURE THAT WILL CONTROL THE WEATHER OVER THE UPPER
LAKES DURING THE LONG TERM IS THE ENERGY THAT HAS PEELED OFF THE
DEEP POLAR VORTEX OVER THE WRN ARCTIC AND IS NOW IN THE PROCESS OF
FORMING A MID LEVEL LOW OVER HUDSON BAY. FARTHER N...THE RIDGES OVER
WRN NAMERICA AND BTWN GREENLAND AND BAFFIN ISLAND WILL CONNECT
ACROSS NRN CANADA OVER THE NEXT DAY OR TWO...FORCING THE MID LEVEL
LOW TO MEANDER EVEN FARTHER S DURING THE WEEK. AT SOME POINT...IT
WILL PASS ACROSS THE UPPER GREAT LAKES/NRN ONTARIO LATE THIS WEEK.
END RESULT IS A CONTINUATION OF A GENERAL BELOW NORMAL TEMP REGIME
FOR UPPER MI OVER THE NEXT 7-10DAYS. WHILE SOME DAYS WILL SEE TEMPS
AROUND NORMAL...THE OVERALL PATTERN SUGGESTS THE POTENTIAL FOR SOME
CHILLY DAYS FOR EARLY AUG STANDARDS AS WELL. THIS IS ESPECIALLY TRUE
LATE WEEK WHEN THE MID LEVEL LOW PASSES AND BRINGS ITS ASSOCIATED
COLD AIR INTO THE AREA. AS FOR PCPN...THERE WILL BE INCREASING PCPN
CHANCES MON/TUE AND PROBABLY INTO WED MORNING AS SHORTWAVES EJECT
FROM A PACIFIC NW/SW CANADA TROF AND TRACK E ACROSS THE NRN CONUS
UNDERNEATH THE MID LEVEL LOW. UNSETTLED WEATHER MAY PUSH THRU THE
AREA AGAIN LATE WEEK DEPENDING ON TRACK OF THE MID LEVEL LOW ACROSS
THE UPPER LAKES AND/OR NRN ONTARIO AND DEPENDING ON WHETHER ANY
ADDITIONAL SHORTWAVES ROTATE AROUND THE LOW.
BEGINNING MON...ATTENTION WILL BE ON THE WELL-DEFINED SHORTWAVE
CURRENTLY OVER SRN SASKATCHEWAN. GIVEN THE PRONOUNCED NW FLOW THIS
MORNING OVER THE UPPER LAKES...IT WOULD SEEM THIS WAVE WON`T BE ABLE
TO MAKE A STRONG PUSH E TO UPPER MI. MODELS DO SHOW FLOW BACKING
WITH UPPER MI UNDER WNW FLOW MON...WHICH STILL SHOULD DIRECT THE
SHORTWAVE AND BULK OF FORCING ESE THRU WI AS DEPICTED BY DEEP LAYER
QVECTORS. THE AXIS OF INSTABILITY REMAINS WELL TO THE SW WITH EVEN
THE INSTABILITY GRADIENT TO THE SW OF HERE. THIS ALSO SUPPORTS THE
IDEA OF MAIN AREA OF PCPN PASSING BY TO THE S. THAT SAID...GIVEN THE
WELL-DEFINED LOOK OF THE SHORTWAVE...SOME PCPN WILL PROBABLY STILL
BRUSH UPPER MI MON AS INDICATED BY ALL MODEL GUIDANCE. IN THE END...
PREFER THE MORE LIMITED NORTHWARD PUSH OF PCPN SHOWN BY THE ECMWF
AND THE 4KM HIGH RES NAM NEST GIVEN ABOVE DISCUSSION. WITH
INSTABILITY AND INSTABILITY GRADIENT TO THE SW...THUNDER LOOKS
UNLIKELY AND WON`T BE MENTIONED. IF THERE IS ANY THUNDER...IT
SHOULD ONLY AFFECT AREAS TOWARD THE WI BORDER.
FCST FOR MON NIGHT IS FAIRLY UNCERTAIN. IT WOULD SEEM DRY WEATHER
SHOULD FOLLOW AS SHORTWAVE CONTINUES TO THE ESE. 850MB WAA AND 850MB
WINDS ARE WEAK (10-15KT)...CERTAINLY SUGGESTING MINIMAL POTENTIAL
FOR MORE ORGANIZED PCPN AREAS. HOWEVER...WITH CYCLONIC 850MB FLOW
AND HINTS OF ONE OR TWO SUBTLE TROFS IN THE WIND FIELD...WILL
MAINTAIN SCHC POPS FOR MUCH OF THE AREA THRU THE NIGHT.
ON TUE...UNUSUALLY DEEP MID LEVEL LOW FOR EARLY AUG WILL BE WOBBLING
S ROUGHLY ALONG THE NE MANITOBA/NRN ONTARIO BORDER. AS A RESULT...
FLOW WILL CONTINUE TO BACK ACROSS THE UPPER GREAT LAKES UNDER THE
EXPANDING CIRCULATION AROUND THE LOW. TO THE W...COMBINATION OF A
SHORTWAVE ROTATING AROUND THE MID LEVEL LOW AND A SHORTWAVE PICKED
UP FROM THE PACIFIC NW/SW CANADA WILL LEAD TO AN ORGANIZING COLD
FRONT MOVING ACROSS THE NRN PLAINS TUE. ORGANIZED PCPN ASSOCIATED
WITH FRONT SHOULD REMAIN W OF UPPER MI THRU TUE AFTN. ACROSS UPPER
MI...NAM/GFS SHOW MLCAPE INCREASING TO AROUND 500J/KG TUE. WITH
HINTS OF A SUBTLE SHORTWAVE PASSING ACROSS THE AREA...WILL INCLUDE
LOW CHC POPS FOR SHRA/TSRA.
AS WAS THE CASE YESTERDAY...MODELS STILL SUGGEST TUE NIGHT AS HAVING
THE BEST SHOT OF SHRA/TSRA AS COLD FRONT PASSES ACROSS UPPER MI TUE
NIGHT/WED MORNING. THERE ARE STILL SOME TIMING ISSUES TO SORT OUT AS
THE GFS/NAM HAVE FRONT OVER THE FAR ERN FCST AREA AT 12Z WED WHILE
THE ECMWF/GEM ARE ABOUT 6-9HRS SLOWER. THE TIMING UNCERTAINTY LEADS
TO LOWER CONFIDENCE IN PIN POINTING PERIOD OF HIGHER POPS. TAKING
INTO ACCOUNT GFS/ECMWF GUIDANCE OVER THE LAST DAY OR TWO...WILL
HEDGE FCST SLIGHTLY TOWARD THE SLOWER SOLUTION...WHICH RESULTS IN
HANGING ONTO HIGHER POPS OVER THE E INTO WED MORNING. IN THE WAKE OF
SHORTWAVE/COLD FRONT...DRY WEATHER WILL FOLLOW W TO E DURING THE DAY
WED.
PLENTY OF UNCERTAINTY REMAINS FOR THU/FRI/SAT REGARDING TIMING/TRACK
OF THE UNUSUALLY DEEP MID LEVEL LOW (500MB HEIGHTS MAY BE AROUND 2.5
STANDARD DEVIATIONS BELOW LONG TERM AVG). IF ANYTHING...THE LAST DAY
OR TWO OF GFS/ECMWF MODEL RUNS SUGGEST A TREND FOR A SLIGHTLY SLOWER
PROGRESSION OF THE MID LEVEL LOW ACROSS NRN ONTARIO DURING THE LAST
HALF OF THE WEEK. THIS SLOWER TREND RAISES THE PROSPECT FOR AT LEAST
ONE SHORTWAVE ROTATING AROUND THE LOW TO AFFECT UPPER MI. THE
PREDICTABILITY OF TIMING A WAVE ROTATING AROUND A MID LEVEL LOW 4 TO
6 DAYS OUT IN A MODEL RUN IS VERY LOW. FOR WHAT IT`S WORTH...LATEST
GUIDANCE SUGGESTS A SHORTWAVE MAY ROTATE THRU THE UPPER LAKES FRI...
PROVIDING THE POTENTIAL FOR SOME SHRA. TEMPS WILL TURN COOLER LATE
WEEK. IN FACT...THERE COULD BE AT LEAST 1 DAY OF WELL BELOW NORMAL
TEMPS WITH HIGHS POTENTIALLY ONLY IN THE MID 50S NEAR LAKE SUPERIOR
AND LOW/MID 60S INLAND.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 258 AM EDT SUN AUG 4 2013
VFR CONDITIONS TO PREVAIL THROUGH THE FORECAST. PATCHY GROUND FOG
DEVELOPED AND THEN DISSIPATED AT KIWD EARLIER THIS
EVENING...TEMPORARILY PRODUCING IFR VISIBILITIES...AND MAY REFORM
LATER OVERNIGHT AS TEMPS/DEWPOINTS CONVERGE. WILL INCLUDE IN FOG IN
KIWD FORECAST AS A TEMPO GROUP AS CONFIDENCE IS NOT HIGH FOR ANY FOG
TO PERSIST. HIGH PRESSURE CONTINUES TO BUILD INTO THE REGION
OVERNIGHT PRODUCING MOSTLY CLEAR SKIES AND LIGHT WINDS. AFTER
DAYBREAK...WINDS WILL PICK UP AGAIN SLIGHTLY BUT SPEEDS WILL REMAIN
BELOW 10 KTS. KSAW WILL ONCE AGAIN BE AFFECTED BY A LAKE BREEZE
DURING THE LATE MORNING HOURS. CLOUD COVER WILL BE ON THE INCREASE
LATE IN THE FORECAST AT KIWD WITH APPROACH OF THE NEXT SYSTEM BUT
ANY PRECIPITATION WILL HOLD OFF BEYOND THIS FORECAST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN AUG 4 2013
THROUGH THIS FCST PERIOD...WINDS SHOULD BE NO HIGHER THAN 20KT WITH
GENERALLY A WEAK PRESSURE GRADIENT DOMINATING THE UPPER GREAT LAKES.
HOWEVER...WILL NEED TO CONTINUE WATCHING THE MID WEEK PERIOD AS A
PASSING COLD FRONT COULD LEAD TO STRONGER PRE FRONTAL AND ESPECIALLY
POST FRONTAL WINDS IN THE LATE TUE/WED TIME FRAME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...RJT
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
333 AM CDT SUN AUG 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT SUN AUG 4 2013
SFC HIGH PRESSURE OVERHEAD TO START TODAY HAS US STARTING OUT WITH
ANOTHER SEASONABLY COOL EARLY AUGUST MORNING. A QUICK LOOK AT WATER
VAPOR SHOWS THE CULPRIT FOR WHAT EVENTUALLY WILL BECOME CATEGORICAL
POPS TONIGHT AND THAT IS A PRETTY POTENT SHORT WAVE SPINNING ACROSS
FAR SW ALBERTA. THIS WAVE GENERATED SOME FAIRLY ROBUST CONVECTION
ACROSS MONTANA LAST NIGHT...WHICH IS NOW ACROSS THE WRN DAKOTAS. A
CONVECTIVELY INDUCED SHORT WAVE IS ASSOCIATED WITH THE DAKOTAS
ACTIVITY. THE DAKOTAS SHORTWAVE IS PROGGED BY THE RAP TO MOVE INTO
NRN MN BY THIS AFTERNOON. HOWEVER...IT WILL NOT BE BRINGING THE
ELEVATED INSTABILITY AND MOISTURE TRANSPORT WITH IT...SO THIS WAVE
WILL DO NOTHING MORE THAN GIVE US A CLOUDIER DAY THAN WHAT WAS SEEN
YESTERDAY. THE ALBERTA WAVE WILL FOLLOW ON THE HEELS OF THE DAKOTAS
WAVE FOR TONIGHT AND WILL BE THE IMPETUS FOR WHAT WILL LIKELY BE AN
ELEVATED MCS ACROSS MUCH OF THE ERN HALF MPX AREA TONIGHT.
FOR TODAY...AS THE SFC HIGH WORKS INTO THE GREAT LAKES...WE WILL
START GETTING INTO WEAK WAA...WITH 925-850 TEMPS LOOKING TO BE A FEW
DEGREES WARMER THAN YESTERDAY...ESPECIALLY ACROSS MN. HOWEVER...MORE
CLOUD COVER IS EXPECTED TODAY THAN YESTERDAY...WHICH SHOULD OFFSET
THIS SLIGHT WARMING...WITH HIGHS TODAY VERY SIMILAR TO SATURDAY AS A
RESULT. STILL HAVE SOME CHANCE POPS REMAINING OUT IN WRN MN THIS
AFTERNOON AS H85 MOISTURE TRANSPORT AND ELEVATED INSTABILITY
BEGIN WORKING INTO MN. BEST SIGNAL FOR PRECIP FOR TODAY LOOKS TO BE
ACROSS NRN MN...WHERE THE GFS/NAM ARE SHOWING SOME DECENT FGEN
DEVELOPING IN THE H85-H5 LAYER...WHICH IS ALSO AT THE NOSE OF THE
H85 MOISTURE TRANSPORT. THIS SHOULD GENERATE AN AREA OF SHOWERS
ACROSS NW MN THAT MAY BLEED INTO WEST CENTRAL MN AFTER 18Z...BUT
STILL SEEING BETTER SIGNAL DOWN HERE FOR PRECIP TONIGHT.
AS FOR TONIGHT...THOUGH SHEERING OUT SOME...THE ALBERTA WAVE WILL BE
MOVING ACROSS NRN MN TONIGHT AND WILL STILL BE STRONG ENOUGH TO
INDUCE A NOCTURNAL STRENGTHENING OF THE LLJ ACROSS MN. NAM/ECMWF/GFS
ALL FAIRLY SIMILAR WITH THE NOSE OF AN ENHANCED AREA OF 925-850
MOISTURE TRANSPORT COMING UP TO ABOUT I-94 FROM 6Z AND BEYOND. AS A
RESULT...HELD OFF ON ANY LIKELY OR HIGHER POPS UNTIL AFTER 6Z...WITH
HEAVIEST AXIS OF PRECIP TONIGHT EXPECTED FROM STC DOWN TOWARD
RST/LSE AND OVER TOWARD EAU. NO SEVERE WEATHER IS EXPECTED WITH THIS
ACTIVITY...BUT PLENTY OF ELEVATED INSTABILITY WILL BE PRESENT TO
ENSURE THESE SHOWERS COME IN THE FORM OF THUNDERSTORMS. AS FOR
PRECIP AMOUNTS...THIS FEATURE LOOKS TO BE TRANSIENT ENOUGH TO KEEP
ACTIVITY MOVING ALONG...BUT WITH PWATS INCREASING TO NEAR 1.5
INCHES...COULD CERTAINLY SEEN AN AXIS OR TWO OF 1 TO 2 INCH RAINFALL
AMOUNTS IF SOME CELL TRAINING OCCURS...THOUGH FOR THE MOST PART
RAINFALL AMOUNTS WILL LIKELY BE A HALF TO ONE INCH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 317 AM CDT SUN AUG 4 2013
SOME RESIDUAL PCPN FROM TONIGHT/S ACTIVITY SHOULD STILL BE
LINGERING OVER THE EASTERN PORTION OF THE AREA MONDAY MORNING.
HOWEVER... THE 850MB FRONTOGENESIS AND MOISTURE TRANSPORT QUICKLY
SHIFTS EAST OF THE AREA ON MONDAY ALONG WITH THE 305-310K
ISENTROPIC LIFT. SO... EXPECT THE MORE WIDESPREAD PCPN TO SHIFT TO
OUR EAST MONDAY MORNING... LEAVING MAINLY DRY CONDITIONS FOR THE
REMAINDER OF THE DAY. HOWEVER... NEGATIVE 850-500MB DIFFERENTIAL
THETA-E VALUES REMAIN IN PLACE THROUGH THE DAY... INDICATING THE
RESIDUAL CONVECTIVE INSTABILITY THAT WILL BE OVER THE AREA. WITH
NO LARGE SCALE FORCING... DON/T EXPECT MUCH PCPN AFTER MONDAY
MORNING... BUT THE LINGERING INSTABILITY COULD LEAD TO A FEW
SHRA/TSRA MONDAY AFTERNOON INTO MONDAY EVENING... PARTICULARLY
OVER THE NORTHERN AND EASTERN PORTION OF THE AREA WHERE BETTER
LAPSE RATES ARE SUGGESTED. THE ARW AND NMM HIGH RESOLUTION WINDOW
RUNS BOTH MANAGE TO DEVELOP SOME SCATTERED SHRA/TSRA MONDAY
AFTERNOON GIVEN THIS SCENARIO... SO KEPT SOME LOW CHANCE POPS
GOING TO ACCOUNT FOR THE POSSIBILITY.
CHANCES FOR MORE WIDESPREAD PCPN WILL RETURN FROM WEST TO EAST ON
TUESDAY AS THE MAIN FRONTAL BOUNDARY WORKS INTO THE AREA WHILE A
STRONG 500MB TROUGH DROPS SOUTH FROM CENTRAL CANADA TOWARD THE
UPPER GREAT LAKES. THERE APPEARS TO BE LESS IN THE WAY OF POTENTIAL
FOR SEVERE WEATHER IN COMPARISON TO EARLIER GUIDANCE... WITH THE
BETTER INSTABILITY STAYING SOUTH OF THE AREA... AND THE FRONTAL
BOUNDARY LOOKING TO BE MORE DIFFUSE AND LATER IN ITS ARRIVAL.
HOWEVER... DEEP LAYER SHEAR IS STILL PROGGED BY THE NAM AND GFS TO
BE AOA 40 KT TUESDAY AFTERNOON INTO TUESDAY EVENING... WITH SOME
MLCAPE VALUES AOA 1000 J/KG CERTAINLY STILL POSSIBLE. LOW LEVEL
SHEAR IS MINIMAL WITH LOW LEVEL WINDS LOOKING TO BECOME
SOUTHWESTERLY AHEAD OF THE FRONT GIVEN ITS ORIENTATION AND LACK OF
ANY DECENT PRESSURE FALLS. WITH THE BEST DYNAMIC FORCING TO OUR
NORTH AND THE BEST THERMODYNAMIC FORCING TO OUR SOUTH... DON/T
EXPECT TO SEE ANYTHING TOO SIGNIFICANT ACROSS OUR AREA AT THIS
POINT. THERE APPEARS TO BE SUFFICIENT INSTABILITY... LOW LEVEL
CONVERGENCE... AND DIFFERENTIAL DIVERGENCE TO GET SOME SHRA/TSRA
GOING... AND GIVEN THE DECENT DEEP LAYER SHEAR IT/S POSSIBLE FOR A
FEW NEAR-SEVERE STORMS... BUT ANYTHING OF SIGNIFICANCE LOOKS TO BE
TO OUR SOUTH AT THIS POINT.
HIGH PRESSURE WILL BUILD ACROSS THE AREA TUESDAY NIGHT INTO
WEDNESDAY... WITH DRY AND COOLER CONDITIONS EXPECTED TO PERSIST
INTO THURSDAY. ANOTHER COLD FRONT WILL MOVE ACROSS THE AREA
SOMETIME FROM LATE THURSDAY INTO FRIDAY... BRINGING A CHANCE FOR
SHRA/TSRA... ALTHOUGH THERE DOESN/T LOOK TO BE MUCH OPPORTUNITY
FOR MOISTURE TRANSPORT AHEAD OF IT. THE TIMING OF THIS NEXT FRONT
IS A GOOD 18 HOURS DIFFERENT BETWEEN THE GFS AND ECMWF... WITH THE
GFS BEING QUICKER. PLAYED THE TIMING IN THE MIDDLE OF THE TWO
SOLUTIONS AT THIS POINT RATHER THAN BLANKETING AN OVERLY LONG
PERIOD WITH CHANCE POPS. ONCE THIS FRONT PUSHES THROUGH WE/LL SEE
HIGH PRESSURE BUILD IN ACROSS THE AREA FOR SATURDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 951 PM CDT SAT AUG 3 2013
VFR TAF...WITH MORE INTERESTING WEATHER BY THE END OF THE PERIOD.
BROUGHT SHOWERS INTO KAXN/KRWF/KSTC BY THE END OF THE TAF. THINK THERE
WILL BE GOOD COVERAGE OF SHOWERS WITH ISOLATED TO SCATTERED WEAK
THUNDERSTORMS DEVELOPING IN MN BETWEEN 02-06 Z TOMORROW NIGHT.
SLIGHTLY HIGHER CONFIDENCE IN OUR RAIN CHANCES FOR SUNDAY NIGHT
AND MONDAY MORNING. EAU CLAIRE COULD ONCE AGAIN SEE AN HOUR OF FOG
NEAR SUNRISE.
KMSP...
THREW IN A PROB30 FOR WEAK THUNDERSTORMS NEAR THE END OF THE TAF.
COVERAGE SHOULD BE SCATTERED...SO NOT HIGH CONFIDENCE IN THE
AIRPORT GETTING HIT AT THIS TIME. BETTER FOCUS MIGHT BE JUST A
COUNTY OR TWO SOUTH OF THE AIRPORT - SHOULD BE CLOSE THOUGH.
/OUTLOOK FOR KMSP/
MON...MVFR CONDS POSSIBLE IN THE MORNING WITH A CHANCE OF
SHRA/TSRA. WINDS S TO W LESS THAN 10 KT.
TUE...MVFR CONDS POSSIBLE WITH A CHANCE OF SHRA/TSRA. WINDS SW 5-10
KTS...SHIFTING TO NW OVERNIGHT.
WED...VFR. WINDS NNW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...
AVIATION...CLF
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1148 PM CDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 933 PM CDT SAT AUG 3 2013
GOING FORECAST STILL LOOKS ON TRACK. SLIGHTLY DRIER AIR CONTINUES
TO ADVECT INTO THE AREA WHICH HAS CAUSED DEWPOINTS TO LOWER THIS
EVENING. SKIES HAVE CLEARED OUT IN MANY LOCATIONS...THOUGH
CONVECTIVE DEBRIS CLOUDS ARE MOVING QUICKLY EASTWARD ACROSS
NORTHERN MO THAT WILL SPREAD ACROSS THE CWA THE NEXT FEW HOURS.
THESE FACTORS SHOULD LIMIT FOG DEVELOPMENT TONIGHT...THOUGH STILL
COULD SEE SOME FORMATION IN LOW LYING AREA. NEAREST THUNDERSTORMS
AT THIS HOUR ARE WELL WEST OF THE CWA IN CENTRAL AND WESTERN
PARTS OF OK/KS. LATEST RAP AND LOCAL WRF RUNS DO NOT BRING ANY LOW
LEVEL MOISTURE CONVERGENCE INTO CENTRAL MO UNTIL AT LEAST MID
MORNING SUNDAY...SO HAVE PUSHED BACK CHANCES OF SHOWERS AND
THUNDERSTORMS UNTIL AT LEAST 15Z.
BRITT
&&
.SHORT TERM...(THROUGH LATE TONIGHT)
ISSUED AT 324 PM CDT SAT AUG 3 2013
RESIDUAL CLOUD COVER DUE TO THE MCS THAT MOVED SOUTHEASTWARD ACROSS
THE REGION EARLIER TODAY CONTINUES TO DIMINISH...AND WILL ALLOW FOR
PARTLY CLOUDY TO MOSTLY CLEAR SKIES OVERNIGHT. REGARDING
PRECIPITATION CHANCES...HAVE GONE AHEAD AND REMOVED POPS OVERNIGHT
ACROSS SOUTHEASTERN AND CENTRAL MISSOURI. DESPITE ADDITIONAL
CONVECTION EXPECTED TO DEVELOP OVER EASTERN KANSAS AND GROW UPSCALE
INTO ANOTHER MCS...GIVEN THE SOUTHWARD PROGRESSION OF THE COLD FRONT
AND BUILDING HIGH PRESSURE...EXPECT THE PROPAGATION OF THE
CONVECTION TO HAVE A MORE SIGNIFICANT SOUTHERLY COMPONENT THAN SHOWN
BY THE MCS LAST NIGHT. RECENT MODEL OUTPUT FROM THE GFS...NAM...AND
ECMWF ECHO THIS IDEA WITH LITTLE IF ANY QPF ANYWHERE OVER THE CWA
PRIOR TO 12Z SUNDAY. THUS...A TRANQUIL EVENING IS EXPECTED ACROSS
THE AREA TONIGHT...WITH LOW TEMPERATURES RANGING FROM THE UPPER 50S
TO MID 60S...SLIGHTLY BELOW NORMAL FOR THIS TIME OF YEAR.
JP
TRUETT
.LONG TERM...(SUNDAY THROUGH NEXT SATURDAY)
ISSUED AT 324 PM CDT SAT AUG 3 2013
AS WE HEAD INTO THE NEW WEEK...QUESTION BECOMES WHEN AND HOW HARD TO
HIT RETURN OF TSRA CHANCES ACROSS THE REGION. AS MENTIONED IN THE
SHORT TERM PORTION OF THE DISCUSSION STRONG INTRUSION OF SURFACE
HIGH TODAY AND TONIGHT...COUPLED WITH EFFECTS OF RAIN-COOLED AMS
FROM LAST NIGHTS MCS...HAS ALLOWED THE BEST INSTABILITY AND
BAROCLINICITY TO MAKE A SUBTLE BUT SIGNIFICANT SW SHIFT.
SO...WHILE THE E FRINGES OF OVERNIGHT CONVECTION MAY BE APPROACHING
OUR W COUNTIES ON SUNDAY MORNING...THE MORE STABLE AND DRIER AIR MAY
CAUSE THE PRECIP TO STRUGGLE TO MAKE TOO MUCH HEADWAY INTO OUR
CWA...ESPECIALLY SINCE LOW LEVEL FLOW MAINTAINS A FAIRLY
PRONOUNCED S COMPONENT THROUGHOUT THE DAY.
HOWEVER...ALL SYNOPTIC MODELS ARE FORECASTING THE LOW LEVEL JET TO
VEER AND BECOME FOCUSED ACROSS THE AREA SUNDAY NIGHT AS SURFACE
RIDGE RETREATS TO THE EAST. THIS WILL TRANSPORT INCREASINGLY MOIST
AND UNSTABLE AIR INTO THE REGION AND INDUCE ISENTROPIC ASCENT OVER
MOST OF NOT ALL OF THE CWA....LEADING TO A THREAT OF NOCTURNAL
CONVECTION FOR MOST OF THE AREA BY DAYBREAK MONDAY. ONCE THE
TSRA CHANCES RETURN SUNDAY NIGHT...IT WOULD APPEAR THAT A
THUNDERSTORM THREAT WILL REMAIN LOCKED OVER THE MID MISSISSIPPI
VALLEY THROUGH MIDWEEK AS DISTURBANCES IN THE NW MID LEVEL FLOW
WILL INTERACT WITH THE MOIST AND UNSTABLE AIRMASS THAT WILL BE
PARKED OVER THE CENTRAL CONUS.
PATTERN IS CERTAINLY ONE THAT COULD LEAD TO A SERIES OF
CONVECTIVE COMPLEXES TO PROPAGATE ACROSS THE AREA THROUGH TUESDAY.
AS IS TYPICAL MODELS ARE VARYING IN THE SPECIFICS OF
FORCING/THERMODYNAMICS AND EVOLUTION OF CONVECTION...BUT HAVE
BASED FORECAST TRENDS MORE ON EXPECTED SYNOPTIC PATTERN THAN ON
THE SPECIFICS OF ANY ONE MODEL. FOR NOW HAVE GONE WITH MIDDLE OF
THE ROAD CHANCE POPS...BUT FULLY EXPECT THAT THERE WILL BE LARGER
SWINGS IN POP NUMBERS AS THE DETAILS/TIMING OF EACH POTENTIAL MCS
BECOMES A BIT CLEARER IN THE NEAR TERM.
OBVIOUSLY...TEMPERATURE SPECIFICS WILL BE HIGHLY DEPENDENT ON TIMING AND
EXTENT OF CONVECTION...BUT FOR NOW HAVE MAINTAINED HIGHS IN THE
80S AND LOWS IN THE UPPER 60S TO LOWER 70S.
MEDIUM RANGE SOLUTIONS ARE NOW FORECASTING AN UPPER LOW TO DIP
INTO S CANADA AND CLIP THE UPPER GREAT LAKES DURING THE LATTER
HALF OF THE WEEK. LEAD SHORTWAVE AND ASSOCIATED COLD FRONT WILL
WORK ACROSS THE REGION WEDNESDAY AND INTO WEDNESDAY EVENING
CONTINUING A THREAT OF SHOWERS AND THUNDERSTORMS. HOWEVER...12Z GFS
AND ECMWF NOW SUGGESTING THAT PRIMARY BAROCLINIC ZONE WILL BE
SHIFTED INTO S MO AND N AR BY THE END OF THE WORK WEEK WITH COOLER
AND MORE STABLE DROPPING S INTO THE N AND MID MISSISSIPPI VALLEY.
BASED ON THIS PATTERN SHIFT HAVE LIMITED CHANCE POPS TO S SECTIONS
OF THE CWA ON THURSDAY AND FRIDAY.
TEMPERATURES DURING THE EXTENDED MAY NOT BE TOO MUCH DIFFERENT
THAN THOSE OF EARLY IN THE WEEK...BUT HUMIDITY LEVELS SHOULD BE LOWER.
TRUETT
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1141 PM CDT SAT AUG 3 2013
EXPECT VFR FLIGHT CONDITIONS TO PREVAIL FOR THE REST OF THE
NIGHT...EXCEPT IN LOCALIZED AREAS IN RIVER VALLEYS. THINK
RELATIVELY THICK CIRRUS OVER THE AREA SHOULD KEEP FOG TO A
MINIMUM...THO MVFR AND EVEN SOME PATCHY IFR IS STILL POSSIBLE IN
THE RIVER VALLEYS. SOME SHORT RANGE GUIDANCE IS HINTING THAT AN
AREA OF SHOWERS AND THUNDERSTORMS MAY AFFECT PARTS OF CENTRAL
MISSOURI AFTER 12Z...BUT THERE SEEMS TO BE NO CONSENSUS YET ON THE
LOCATION OF THE PRECIPITATION...MOST MODELS ARE KEEPING IT FURTHER
TO THE SOUTHWEST. WILL ADD IN VCSH TO THE KCOU TAF SUNDAY
MORNING...BUT AM NOT VERY CONFIDENT IN THE PLACEMENT OF THE
PRECIPITATION. EXPECT THE REMAINDER OF THE AREA TOR REMAIN DRY
WITH VFR CONDITIONS SUNDAY INTO SUNDAY EVENING.
SPECIFICS FOR KSTL...
VFR FLIGHT CONDITIONS WILL CONTINUE TO PREVAIL AT LAMBERT. THERE
COULD BE SOME SHOWERS AND STORMS FIRING UP EARLY SUNDAY MORNING
OVER CENTRAL MISSOURI...BUT I EXPECT ANY STORMS THAT DO FORM TO
REMAIN WELL WEST OF THE TERMINAL.
CARNEY
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
417 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE CONTINUES ACROSS OUR REGION TODAY WITH
ADDITIONAL SHOWERS WITH EMBEDDED THUNDERSTORMS POSSIBLE.
TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS MAINLY
IN THE 60S TO NEAR 70. HIGH PRESSURE LOCATED OVER THE CENTRAL GREAT
LAKES WILL SHIFT INTO THE REGION ON MONDAY...WITH CLEARING SKIES AND
COOL TEMPERATURES. A WARMING TREND IS EXPECTED BY THE MIDDLE OF THIS
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 415 AM EDT SUNDAY...ONCE AGAIN FCST FOCUS WL BE AREAL
COVERAGE/INTENSITY OF SHOWERS/STORMS TODAY. WATER VAPOR SHOWS
DEEP MID/UPPER LVL TROF ACRS THE NE CONUS...WITH TWO ADDITIONAL
S/W`S EXPECTED TO IMPACT OUR CWA TODAY. FIRST S/W IS LOCATED OVER
JUST NORTH OF THE EASTERN GREAT LAKES...AND WL BE ACRS OUR WESTERN
ZNS BTWN 12-15Z TODAY...MEANWHILE STRONG ENERGY BTWN HUDSON BAY
AND NORTHERN GREAT LAKES WL APPROACH OUR CWA BY 18Z TODAY. THIS
PIECE OF ENERGY DIVING ALONG THE SOUTHERN PERIPHERY OF TROF WL
HELP DEVELOP A CLOSED 5H/7H CIRCULATION OVER SOUTHERN CANADA BY
00Z MONDAY. THIS CYCLONIC UPSLOPE FLW...ALONG WITH LLVL CAA...AND
LEFTOVER 1000 TO 700 MOISTURE WL HELP IN THE DEVELOPMENT OF
ADDITIONAL UPSLOPE SHOWERS THIS EVENING. FOR TODAY...WL CONT TO
MENTION LIKELY POPS WITH GREATEST CHCS ACRS THE NORTHERN/CENTRAL
ZNS...WHERE 850 TO 500MB RH IS THE DEEPEST. IN ADDITION...BEST PVA
ASSOCIATED WITH 5H VORT AND NOSE OF 25H JET IS ACRS THIS REGION.
LATEST RAP SOUNDINGS CONT TO SUPPORT SOME SFC HEATING RESULTING IN
CAPE VALUES BTWN 800 AND 1200 J/KG...AND LIS AROUND -2C...FROM
DEVELOPING COLD POOL ALOFT. THIS INSTABILITY SHOULD PROMOTE STRONG
ENOUGH UPDRAFTS TO SUPPORT MENTION OF THUNDER...ESPECIALLY MTNS
AND NORTHERN CWA. THE COMBINATION OF LOW WET BULB ZERO HEIGHTS
ASSOCIATED WITH COLD THERMAL PROFILES...SOME SMALL HAIL WL BE
POSSIBLE...IN ADDITION TO LOCALIZED WIND GUSTS TO 30 MPH. THE LACK
OF INSTABILITY WL KEEP STORMS BLW SVR LIMITS THIS AFTN AND LIMITED
DEEP MOISTURE WL LIMIT AREAL COVERAGE. WL MENTION CHCS IN
HWO...BUT NOT ZONES ATTM. CWMW SOUNDING SHOWS 1000 TO 850MB TEMPS
BTWN 1 AND 3C COOLER THAN 24HR AGO...SUPPORTING HIGHS ONLY IN THE
60S MTNS TO NEAR 70F VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 415 AM EDT SUNDAY...LARGE SCALE SYNOPTIC FORCING FROM
POTENT 5H VORT WL TRANSITION TO MESOSCALE UPSLOPE LIFT AS CYCLONIC
NW FLW CONTS ACRS OUR REGION TONIGHT. EXPECT AREAL COVERAGE/INTENSITY OF
PRECIP TO QUICKLY DISSIPATE BY 00Z THIS EVENING...WITH
PRECIP CONFINED ALONG THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/GREEN MTNS. UPSLOPE PROCEDURE SHOWS GOOD 1000 TO 700MB
RH...FAVORABLE SFC TO 700MB FLW OF 20 TO 30 KNOTS...AND ASSOCIATED
ENHANCED UVVS ACRS THE WESTERN SLOPES. WL MENTION LIKELY POPS THRU
03Z ACRS THE MTNS...WITH SCHC/CHC POPS ELSEWHERE...AFT 03Z DEEP
LAYER MOISTURE QUICKLY DECREASES AS SUBSIDENCE DEVELOPS. THIS WL
RESULT IN CLRING SKIES IN MOST LOCATIONS BY MORNING...EXCEPT
NORTHERN VT. LLVL CAA RESULTS IN PROGGED 85H TEMPS BTWN 2-4C BY
12Z MONDAY...WITH GOOD BL MIXING. THIS WL SUPPORT ADVECTION TYPE
COOLING WITH LOWS RANGING FROM THE U30S SLK TO NEAR 50F CPV. IF
WINDS DECOUPLE AT SLK...COULD SEE TEMPS DROP INTO THE MID 30S BY
12Z MONDAY.
MONDAY AND TUESDAY...SFC HIGH PRES BUILDING ACRS OUR CWA WL RESULT
IN DRY CONDITIONS AND BLW NORMAL TEMPS. THERMAL SOUNDINGS SUGGEST
MORE OF A FALL LIKE TEMP PROFILE ON MONDAY. PROGGED 85H TEMPS BTWN
4-6C...WITH MOSTLY SUNNY SKIES SUPPORT HIGHS 60S TO NEAR 70 MOST
LOCATIONS. A CHILLY NIGHT IS EXPECTED ON MONDAY NIGHT/TUES MORNING
WITH LOWS RANGING FROM M30S SLK/LAKE PLACID/NEK TO M/U 40S CPV...AND
MID 50S NEAR THE LAKE. TUESDAY...WEAK LLVL WAA DEVELOPS WITH MAINLY
CLR SKIES AND TEMPS IN THE 70S. INTERESTING TO SEE THE GOOD MIXING
ON MONDAY AFTN...AND HOW THE SFC DWPTS DROP INTO THE M/U 30S...VERY
DRY AIR IS PROGGED TO MIX DOWN....RESULTING IN LOW RH VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...LARGE UPPER TROUGH TAKES SHAPE OVER CENTRAL
CANADA AND THE UPPER MIDWEST TUESDAY NIGHT INTO WEDNESDAY
MORNING. THIS WILL HELP TO BACK THE UPPER FLOW TO THE WEST AND
SOUTHWEST ON WEDNESDAY. THIS WILL ALLOW 850/925 MILLIBAR
TEMPERATURES TO RISE AND LOOKING AT HIGH TEMPERATURES RIGHT AROUND
SEASONAL NORMALS WEDNESDAY. CLOUDS WILL ALSO BE ON THE INCREASE
AND THERE COULD BE SOME AFTERNOON THUNDERSTORMS...BUT IT APPEARS
BEST DYNAMIC SUPPORT/SURFACE COLD FRONT DO NOT MOVE INTO THE AREA
UNTIL WEDNESDAY NIGHT AND THURSDAY. GOING FORECAST HAS THIS IDEA
COVERED WELL AND HAVE CONTINUED THIS THINKING IN THE GRIDS.
FORCING/COLD FRONT MOVE EAST OF THE AREA THURSDAY NIGHT FOR A
DRYING TREND AND PRONOUNCED WESTERLY FLOW ALOFT DEVELOPS OVER THE
AREA ON FRIDAY. LOW LEVEL THERMAL PROFILE SHOWS WARMEST READINGS
OF THE WEEK MOVE INTO THE AREA ON FRIDAY. THIS WILL PRODUCE HIGH
TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS. AN UPPER LEVEL
DISTURBANCE WILL APPROACH THE AREA LATER ON SATURDAY... BUT BEST
FORCING LOOKS TO STAY UP IN CANADA...THUS GOING FORECAST OF A
SLIGHT CHANCE OF SHOWERS LOOKS GOOD.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
THROUGH 06Z MONDAY...VFR CONDITIONS ARE EXPECTED THROUGH
14Z...THEN AN UPPER LEVEL DISTURBANCE DROPS DOWN FROM CANADA AND ENHANCES
THE POTENTIAL FOR PRECIPITATION RIGHT THROUGH 02Z. THE SHOWERS WILL
GENERALLY BE LIGHT AND VISIBILITIES WILL REMAIN IN THE VFR CATEGORY.
HOWEVER...VISIBILITIES WILL LOWER INTO THE MVFR CATEGORY AFTER 14Z
AND REMAIN THERE FOR THE REMAINDER OF THE PERIOD. LIGHT WINDS EARLY
THIS MORNING WILL BECOME NORTHWEST AFTER 12Z AT SPEEDS AROUND 10
KNOTS THROUGH MUCH OF THE REMAINDER OF THE PERIOD.
OUTLOOK 06Z MONDAY THROUGH THURSDAY...
06Z MONDAY THROUGH 00Z THURSDAY...VFR UNDER SURFACE HIGH PRESSURE.
00Z THURSDAY THROUGH 00Z FRIDAY...VFR TRENDING TO MVFR/IFR IN
SHOWERS AND STORMS AS A WARM FRONT LIFTS ACROSS THE NORTHEAST.
&&
.EQUIPMENT...
AS OF 1225 PM EDT SATURDAY...NOAA WEATHER RADIO WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR HAS RETURNED TO SERVICE. HOWEVER...TECHNICIANS HAVE
DETERMINED THAT ADDITIONAL WORK IS NEEDED AT THE SITE. PARTS ARE
ON ORDER...WITH ADDITIONAL DOWNTIME EXPECTED AS EARLY AS NEXT
WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
148 AM EDT SUN AUG 4 2013
.SYNOPSIS...
COOL HIGH PRESSURE WILL MOVE OVER NY AND PA TO START THE NEW WEEK.
CHILLY AIR FLOWING OVER THE WARM LAKES WILL PRODUCE A FEW
SPRINKLES OR SHOWERS OVER NORTHERN PORTIONS OF OUR REGION ON
SUNDAY. MILDER AIR AND A FEW SHOWERS ARE EXPECTED TUESDAY, AS
MOISTURE RETURNS FROM THE SOUTH.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
SHOWER ACTIVITY ALONG THE CENTRAL/NORTHERN PA FRONTAL REMNANTS IS
DIMINISHING, WHILE NEW ACTIVITY IS POPPING UP OVER NORTHERN NY
AHEAD OF APPROACHING SHORT WAVE.
MINOR CHANGES TO THE POP/TEMP GRIDS OVERNIGHT TO REFLECT OBSERVED
TRENDS. OTHERWISE, THINKING REMAINS THE SAME - APPROACHING SHORT
WAVE WILL DESTABILIZE LOWER ATMOSPHERE OVER NORTHERN NY. COOL AIR
FLOWING OVER RELATIVELY WARM LAKE WATERS WILL CAUSE LAKE EFFECT OR
ENHANCED SHOWERS AND SPRINKLES INTO SUNDAY.
PREV DISC...
RADAR WAS LARGELY FREE OF ECHOES EARLY THIS AFTERNOON EXCEPT FOR A
FEW VERY ISLD SHRA OCCASIONALLY POPPING UP HERE AND THERE BUT
BEING SHORT-LIVED. ACVTY SEEMS TO BE A TAD MORE PREVALENT IN NE
PA NR SFC FRNT WHICH EXTENDED FROM NRN CATSKILLS TO BTWN IPT AND
AVP IN NE PA IN OUR FORECAST AREA. WATER VAPOR IMAGERY SHOWS
SIGNIFICANT UPPER LEVEL WAVE MOVG ACRS NRN NEW ENGLAND AND SERN
CANADA. THIS WAVE WAS ENHANCING STRG UPR CONFLUENCE ACRS NEW
ENGLAND TO NOVA SCOTIA AND HENCE AN UPPER LEVEL JET STREAK WAS
POSITIONED IN THIS AREA. ENHANCED DVRG IN THE RR QUAD OF THE JET
WAS PROMOTING SOME LIFTING INTO NE PA AND ITS LOWER LEVEL AGEO
FORCING WAS ALSO PUSH THE FRNT SOUTHWARD. BEST SHOT OF A FEW SHRA
AND EVEN A LITTLE TSRA WILL BE MAINLY ACRS OUR FAR SE FORECAST
AREA IN THE POCONOS TO SRN CATSKILLS FOR THE REST OF THE
AFTERNOON DUE TO THIS DYNAMICAL FORCING. NORTH OF THE FRNT...THE
CUMULUS WAS BUILDING BUT NOT TO EXTENT THAT I EARLIER THHOUGHT.
THE ONLY EXCEPTION WAS OVER AREAS DIRECTLY DOWNWIND OF LAKE
ONTARIO WHERE LAKE MOISTURE WAS ENHANCING LL MOISTURE AND LEADING
TO DEEPER CUMULUS AND A LITTLE ISLD SHRA ACVTY AT TIMES. HENCE
HAVE SOME ISLD CHC OF SHRA WELL N OF THE FRNT ACRS CNTRL NY AND
NRN PA. THIS ACVTY WILL WANE SOON EXCEPT IN NC NY DOWNWIND OF LAKE
ONTARIO.
FOR TONIGHT...INITIALLY CUMULUS AND ISLD SHRA WILL FALL APART WITH
LOSS OF INSOLATION. CONTINUED LL NW FLOW AND CAA WILL CONT ACRS
THE RELATIVELY WARM WATERS OF LAKE ONTARIO. LAKE ONTARIO TEMPS
WERE RUNNING ARND 20-21C AS 850 MB TEMPS DROP TO ARND 7-8C OR SO BY
LATE TONIGHT. ADDTNLY ANOTHER SHRT WAVE WILL DROP SOUTHWARD
OVERNIGHT REACHING SOUTHEAST ONTARIO AND WESTERN QUEBEC BY 12Z.
LIFTING FROM THIS WAVE IN ASSCTN WITH LAKE MOISTURE WILL TRIGGER
SHRA AGAIN LATER TONIGHT IN NC NY...WITH NO PRECIPITATION EXPECTED
IN SC NY DOWN TO NE PA BEFORE 12Z.
THEN FOR SUNDAY...UPPER LEVEL WAVE PASSES TO THE EAST BUT IS
FOLLOWING BY AN EVEN CHILLIER SHOT OF AIR WITH 850 MB TEMPS
DROPPING TO ARND 6C WHICH IS ABT A 14-15C DIFFERENTIAL. THE FLOW
REMAINS ABT 310 OR SO WHICH WILL BRING LAKE MOISTURE DOWN INTO THE
HILLS OF NC NY AND DOWN TO SC NY AND FAR NE PA. WITH INSOLATION
AND COLD TEMPERATURES AT 850 MB I SEE ISLD TO SCT SHRA FROM NRN PA
TO SC NY AND SCT SHRA INTO NC NY DIRECTLY DOWNWIND OF LAKE
ONTARIO. THE ACVTY WILL WANE LATER IN THE DAY AS INSOLATION BREAKS
UP ANY ORGANIZED LAKE EFFECT RAINS. HAVE SLGHT CHC IN NE PA TO LO
CHC IN SC NY TO HIGH CHC IN NC NY FOR SUNDAY.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION SUNDAY NIGHT AND CROSS
THE REGION MONDAY AND MONDAY NIGHT WITH FAIR WEATHER. WITH LIGHT
WINDS I EXPECT PLENTY OF VALLEY FOG LATE SUNDAY NIGHT AND LATE
MONDAY NIGHT. FOR TUESDAY A WARM FRONT AND SOUTHERLY RETURN FLOW
WILL LIKELY SPREAD A FEW SHRA INTO NE PA AND C NY. THE
CMC...EURO...GFS AND NAM ALL INDICATE TO VARYING DEGREES THAT
THERE WILL BE ENUF MOISTURE ADVECTION FOR SOME PATCHY SHRA ACTVY.
I WENT SLGHT CHC FOR NOW FOR SHRA. OTHERWISE...FAIRLY QUIET ON
TUESDAY AND A LITTLE MILDER.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
RISING HGTS ON TUE WILL RESULT IN SOME INCRSG CLDS BUT SHWRS SHD
BE LIMITED DUE TO STUBBORN LL DRY AIR. YET ANOTHER DIGGING LOW
APCHS FOR WED AND THU AND PUSHES A SFC BNDRY THRU THE AREA. GOOD
GULF CONNECTIONS SHD LEAD TO GOOD CVRG OF SHWRS AND TRWS LATE WED
INTO THU AHD OF THE TROF. DRIER AND COOLER AIR RETURNS ON FRI BHD
THE FNT. ATTM IT LOOKS DRY BHD THE FNT BUT EVENTUALLY THE LWRG
HGTS WITH THE LRG UA LOW WILL RESULT IN MAINLY AFTN CONV.
TEMPS WILL CONT TO AVG WELL BLO SEASONAL NORMS THRU THE PD. MEX
GUID WAS RUNNING A BIT HIER THRU THE PD THAN HPC BUT SEEMED LIKE
THE COOLER EURO HAD A BETTER HANDLE ON THE UA LOW SO MORE CLOSELY
FLWD HPC GUID.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
130 AM EDT UPDATE...
A COLD FRONT WILL MOVE ACROSS THE REGION LATE TONIGHT AND SCATTERED
SHOWERS WILL DEVELOP IN ITS WAKE. BEHIND THE COLD FRONT MVFR CIGS
AND GUSTY WINDS WILL DEVELOP AND ARE EXPECTED TO PREVAIL THROUGH
MID DAY SUNDAY FOR MUCH OF THE AREA. SHOWERS ARE EXPECTED TO
CONTINUE THROUGH THE AFTERNOON AS WELL. MVFR CIGS WILL START TO
LIFT TO VFR BY EARLY EVENING OVER NORTHEAST PENNSYLVANIA. VFR
CONDITIONS WILL MOVE WESTWARD AS THE EVENING HOURS PROGRESS. AFTER
SUNSET WINDS WILL BECOME LIGHT AND VARIABLE WITH SCATTERED TO FEW
CLOUDS.
MON THRU WED...MAINLY VFR.
THU...MVFR IN SHRA AND TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP
NEAR TERM...DJN/DJP
SHORT TERM...DJN
LONG TERM...DGM
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
152 AM CDT SUN AUG 4 2013
.UPDATE...
ISSUED AT 151 AM CDT SUN AUG 4 2013
UPDATED THE FORECAST TO REMOVE THE SEVERE THUNDERSTORM WATCH FOR
ALL OF SOUTHWESTERN NORTH DAKOTA. ALSO ADJUSTED THE HOURLY POPS TO
HONE IN ON THE AREA OF PRECIPITATION MOVING FROM WEST TO EAST
PRIMARILY SOUTH OF I-94. THE UPDATED GRIDDED AND TEXT PRODUCTS
HAVE BEEN SENT.
UPDATE ISSUED AT 1157 PM CDT SAT AUG 3 2013
UPDATE TO CLEAR GOLDEN VALLEY/BILLINGS FROM SEVERE THUNDERSTORM
WATCH. PER LATEST SWOMCD...MARGINAL SEVERE WEATHER THREAT MAY
PERSIST INTO THE EARLY MORNING AND WILL KEEP REMAINDER OF WATCH
GOING. MADE SOME ADDITIONAL CHANGES TO POPS PER LATEST RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD WILL BE
THUNDERSTORM CHANCES.
CURRENTLY...ALTHOUGH NOT REAL WARM...A MOIST UNSTABLE ATMOSPHERE
IS DEVELOPING ACROSS EASTERN MONTANA AND FAR WESTERN NORTH DAKOTA.
A SHORTWAVE INDICATED OVER NORTH CENTRAL MONTANA IN A PROGRESSIVE
BAND OF WESTERLIES HAS INITIATED CONVECTION WEST OF GLASGOW.
EXPECT CONVECTION TO CONTINUE TO INCREASE IN AN AREA OF STEEPENING
LAPSE RATES AND STRONG DEEP LAYER SHEAR. THE 18 UTC HRRR INDICATES
DISCRETE SUPERCELLS TRACKING ACROSS EASTERN MONTANA THIS AFTERNOON
AND EVENING...CLIPPING THE FAR SOUTHWEST LATE THIS EVENING. THE
12 UTC WRF AND HIRES-NMM/ARW ARE SIMILAR BUT MAYBE A BIT LATER AND
TRANSITION FROM DISCRETE CELLS INTO AN MCS THAT TRACKS ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE TONIGHT INTO SUNDAY MORNING.
WHATEVER EVENTUALLY PANS OUT...WILL DEFINITELY BUMP UP POPS
TONIGHT AND SUNDAY. HAVE INCLUDED A MENTION OF SEVERE ACROSS THE
SOUTHWEST THIS EVENING. AFTER MIDNIGHT...ALTHOUGH A SEVERE STORM
CANNOT BE RULED OUT...THINK WE WILL BE ON THE DOWNWARD TREND.
HIGH TEMPERATURES ON SUNDAY WILL DEPEND GREATLY ON THE ONGOING
CONVECTION THAT TRACKS ACROSS CENTRAL INTO EASTERN NORTH DAKOTA
DURING THE DAY. UTILIZED A BLEND WITH MORE WEIGHT TOWARD RAW MODEL
GUIDANCE WHICH USUALLY WORKS WELL IN A CHANGEABLE WEATHER PATTERN.
THIS RESULTS IN A NICE GRADIENT FROM UPPER 60S ACROSS THE NORTH
CENTRAL WHERE SHOWERS HANG ON INTO THE AFTERNOON...TO AROUND 80
OVER THE SOUTHWEST WHERE WE CLEAR OUT EARLY AND TEMPERATURES
REBOUND NICELY. THE WEST WILL ALSO BEGIN TO DESTABILIZE ONCE
AGAIN SUNDAY AFTERNOON...WITH A FAVORABLE SHEAR ENVIRONMENT
REMAINING OVER THE AREA. WILL NOT MENTION SEVERE WORDING AT THIS
TIME BUT WILL KEEP A CHANCE OF THUNDERSTORMS REMAINING ACROSS ALL
OF WESTERN NORTH DAKOTA SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
CHANCES FOR PRECIPITATION WILL DECREASE WEST TO EAST SUNDAY
EVENING INTO EARLY MONDAY MORNING AS A MID LEVEL SHORTWAVE TROUGH
AND AREA OF SURFACE LOW PRESSURE MOVE EAST INTO THE GREAT LAKES
REGION AND SURFACE HIGH PRESSURE BUILDS ACROSS WESTERN NORTH
DAKOTA.
WE REMAIN IN NORTHWEST FLOW ALOFT MONDAY WITH UPPER LEVEL RIDGING
ACROSS THE SOUTHERN PLAINS AND DEEP LOW PRESSURE OVER THE WESTERN
HUDSON BAY. WILL SEE INCREASING CHANCES OF SHOWERS/THUNDERSTORMS
LATER MONDAY WEST AND NORTH AND MONDAY NIGHT AREA WIDE AS THE
UPPER LOW DRIFTS SOUTHWARD ALLOWING FOR INCREASING CYCLONIC FLOW
ALOFT INTO THE NORTHERN PLAINS. MODELS ARE KEYING IN ON TWO
DISTINCT MID LEVEL IMPULSES ROTATING THROUGH THE FLOW ACROSS NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING. BEST CHANCES FOR
PRECIPITATION WILL BE ACROSS MY NORTH AND EAST WHERE BEST LOW
LEVEL FORCING IS CURRENTLY FORECAST.
BY TUESDAY AFTERNOON...THE UPPER LEVEL LOW IS FORECAST TO BE ABOUT
250-400 MILES NORTHEAST OF LAKE WINNIPEG MAINTAINING STRONG
CYCLONIC FLOW ALOFT...WHICH PERSISTS THROUGH WEDNESDAY. LINGERING
LOW LEVEL MOISTURE COUPLED WITH EMBEDDED ENERGY IN THE FLOW ALOFT
WILL MAINTAIN SOME CHANCE FOR DIURNALLY DRIVEN SHOWERS/ISOLATED
THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY. HOWEVER...LOW LEVEL
FORCING IS PROGGED WEAK SO WIDESPREAD PRECIPITATION IS NOT
EXPECTED. IN ADDITION...MUCH COOLER CANADIAN AIR WILL FILTER INTO
THE REGION TUESDAY/TUESDAY NIGHT AND WEDNESDAY (HIGHS IN THE
LOW/MID 70S AND LOWS TUESDAY NIGHT LOW 50S/UPPER 40S).
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO THURSDAY...THEN
INTO EASTERN CANADA BY SATURDAY. HIGH PRESSURE IS FORECAST TO
BUILD ACROSS THE DAKOTAS THURSDAY AND THURSDAY NIGHT...REMAINING
IN PLACE WELL INTO SATURDAY. THIS WILL LEAD TO MAINLY DRY
CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES OVER MOST OF
THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1157 PM CDT SAT AUG 3 2013
THUNDERSTORMS EXPECTED TO SPREAD EAST...IMPACTING KBIS AND KMOT
OVERNIGHT INTO SUNDAY MORNING...AND PERHAPS KJMS BY MIDDAY. BRIEF
MVFR VSBYS WILL BE POSSIBLE IN THE STRONGER STORMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...TWH
LONG TERM...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1205 AM CDT SUN AUG 4 2013
.UPDATE...
ISSUED AT 1157 PM CDT SAT AUG 3 2013
UPDATE TO CLEAR GOLDEN VALLEY/BILLINGS FROM SEVERE THUNDERSTORM
WATCH. PER LATEST SWOMCD...MARGINAL SEVERE WEATHER THREAT MAY
PERSIST INTO THE EARLY MORNING AND WILL KEEP REMAINDER OF WATCH
GOING. MADE SOME ADDITIONAL CHANGES TO POPS PER LATEST RADAR TRENDS.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD WILL BE
THUNDERSTORM CHANCES.
CURRENTLY...ALTHOUGH NOT REAL WARM...A MOIST UNSTABLE ATMOSPHERE
IS DEVELOPING ACROSS EASTERN MONTANA AND FAR WESTERN NORTH DAKOTA.
A SHORTWAVE INDICATED OVER NORTH CENTRAL MONTANA IN A PROGRESSIVE
BAND OF WESTERLIES HAS INITIATED CONVECTION WEST OF GLASGOW.
EXPECT CONVECTION TO CONTINUE TO INCREASE IN AN AREA OF STEEPENING
LAPSE RATES AND STRONG DEEP LAYER SHEAR. THE 18 UTC HRRR INDICATES
DISCRETE SUPERCELLS TRACKING ACROSS EASTERN MONTANA THIS AFTERNOON
AND EVENING...CLIPPING THE FAR SOUTHWEST LATE THIS EVENING. THE
12 UTC WRF AND HIRES-NMM/ARW ARE SIMILAR BUT MAYBE A BIT LATER AND
TRANSITION FROM DISCRETE CELLS INTO AN MCS THAT TRACKS ACROSS THE
SOUTHWEST AND FAR SOUTH CENTRAL LATE TONIGHT INTO SUNDAY MORNING.
WHATEVER EVENTUALLY PANS OUT...WILL DEFINITELY BUMP UP POPS
TONIGHT AND SUNDAY. HAVE INCLUDED A MENTION OF SEVERE ACROSS THE
SOUTHWEST THIS EVENING. AFTER MIDNIGHT...ALTHOUGH A SEVERE STORM
CANNOT BE RULED OUT...THINK WE WILL BE ON THE DOWNWARD TREND.
HIGH TEMPERATURES ON SUNDAY WILL DEPEND GREATLY ON THE ONGOING
CONVECTION THAT TRACKS ACROSS CENTRAL INTO EASTERN NORTH DAKOTA
DURING THE DAY. UTILIZED A BLEND WITH MORE WEIGHT TOWARD RAW MODEL
GUIDANCE WHICH USUALLY WORKS WELL IN A CHANGEABLE WEATHER PATTERN.
THIS RESULTS IN A NICE GRADIENT FROM UPPER 60S ACROSS THE NORTH
CENTRAL WHERE SHOWERS HANG ON INTO THE AFTERNOON...TO AROUND 80
OVER THE SOUTHWEST WHERE WE CLEAR OUT EARLY AND TEMPERATURES
REBOUND NICELY. THE WEST WILL ALSO BEGIN TO DESTABILIZE ONCE
AGAIN SUNDAY AFTERNOON...WITH A FAVORABLE SHEAR ENVIRONMENT
REMAINING OVER THE AREA. WILL NOT MENTION SEVERE WORDING AT THIS
TIME BUT WILL KEEP A CHANCE OF THUNDERSTORMS REMAINING ACROSS ALL
OF WESTERN NORTH DAKOTA SUNDAY AFTERNOON.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 321 PM CDT SAT AUG 3 2013
CHANCES FOR PRECIPITATION WILL DECREASE WEST TO EAST SUNDAY
EVENING INTO EARLY MONDAY MORNING AS A MID LEVEL SHORTWAVE TROUGH
AND AREA OF SURFACE LOW PRESSURE MOVE EAST INTO THE GREAT LAKES
REGION AND SURFACE HIGH PRESSURE BUILDS ACROSS WESTERN NORTH
DAKOTA.
WE REMAIN IN NORTHWEST FLOW ALOFT MONDAY WITH UPPER LEVEL RIDGING
ACROSS THE SOUTHERN PLAINS AND DEEP LOW PRESSURE OVER THE WESTERN
HUDSON BAY. WILL SEE INCREASING CHANCES OF SHOWERS/THUNDERSTORMS
LATER MONDAY WEST AND NORTH AND MONDAY NIGHT AREA WIDE AS THE
UPPER LOW DRIFTS SOUTHWARD ALLOWING FOR INCREASING CYCLONIC FLOW
ALOFT INTO THE NORTHERN PLAINS. MODELS ARE KEYING IN ON TWO
DISTINCT MID LEVEL IMPULSES ROTATING THROUGH THE FLOW ACROSS NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING. BEST CHANCES FOR
PRECIPITATION WILL BE ACROSS MY NORTH AND EAST WHERE BEST LOW
LEVEL FORCING IS CURRENTLY FORECAST.
BY TUESDAY AFTERNOON...THE UPPER LEVEL LOW IS FORECAST TO BE ABOUT
250-400 MILES NORTHEAST OF LAKE WINNIPEG MAINTAINING STRONG
CYCLONIC FLOW ALOFT...WHICH PERSISTS THROUGH WEDNESDAY. LINGERING
LOW LEVEL MOISTURE COUPLED WITH EMBEDDED ENERGY IN THE FLOW ALOFT
WILL MAINTAIN SOME CHANCE FOR DIURNALLY DRIVEN SHOWERS/ISOLATED
THUNDERSTORMS BOTH TUESDAY AND WEDNESDAY. HOWEVER...LOW LEVEL
FORCING IS PROGGED WEAK SO WIDESPREAD PRECIPITATION IS NOT
EXPECTED. IN ADDITION...MUCH COOLER CANADIAN AIR WILL FILTER INTO
THE REGION TUESDAY/TUESDAY NIGHT AND WEDNESDAY (HIGHS IN THE
LOW/MID 70S AND LOWS TUESDAY NIGHT LOW 50S/UPPER 40S).
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO THURSDAY...THEN
INTO EASTERN CANADA BY SATURDAY. HIGH PRESSURE IS FORECAST TO
BUILD ACROSS THE DAKOTAS THURSDAY AND THURSDAY NIGHT...REMAINING
IN PLACE WELL INTO SATURDAY. THIS WILL LEAD TO MAINLY DRY
CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES OVER MOST OF
THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1157 PM CDT SAT AUG 3 2013
THUNDERSTORMS EXPECTED TO SPREAD EAST...IMPACTING KBIS AND KMOT
OVERNIGHT INTO SUNDAY MORNING...AND PERHAPS KJMS BY MIDDAY. BRIEF
MVFR VSBYS WILL BE POSSIBLE IN THE STRONGER STORMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...RK
SHORT TERM...TWH
LONG TERM...NH
AVIATION...RK
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
356 AM EDT SUN AUG 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY FROM THE NORTHWEST.
THE HIGH WILL MOVE TO THE EAST COAST ON TUESDAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A COLD FRONT EXPECTED ACROSS
THE AREA ON THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
WEAK TROUGH AND WIND SHIFT...FORECAST ON THE HRRR AND VISIBLE ON
RADAR MANAGED TO EXPLOIT THE INSTABILITY OVER THE WARM LAKE TO
PRODUCE A FEW SHOWERS AND THUNDERSTORMS SHORTLY AFTER MIDNIGHT.
EXPECT THE SHOWERS TO DISSIPATE AS THEY DROP SOUTH ACROSS THE AREA
THROUGH THE NIGHT. WILL HAVE A SLIGHT CHANCE POP FOR THE NORTHEAST
FOR THE FIRST HALF OF THE DAY HOWEVER WITH SO MUCH DRY AIR IN THE
MID LEVELS MOVING IN NOT EXPECTING MUCH. LOW LEVEL MOISTURE STILL
IN PLACE HOWEVER SO AM THINKING WE WILL HAVE A GOOD CU FIELD TO
DEVELOP...POSSIBLY GOING BROKEN FOR A FEW HOURS BEFORE MIXING OUT
BACK TO SCATTERED. OUTSIDE CHANCE POPS WILL NEED TO BE RAISED AS
850MB TEMPS DROP TO +7C AND WITH THE LAKE AT +20C IT COULD BE
PROBLEMATIC IF AIRMASS HAS A BIT MORE MID LEVEL MOISTURE THAN
ANTICIPATED. AFTERNOON TEMPS INDICATIVE OF MID TO LATE SEPTEMBER.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND EARLY MONDAY.
EXPECTING MOSTLY CLEAR SKIES WITH WELL BELOW NORMAL TEMPS. MONDAY
AFTERNOON THE HIGH MOVES EAST AND THE NAM AND GFS SHOW SUFFICIENT
MOISTURE FOR AT LEAST THE THREAT OF A SHOWER IN THE WEST DURING
THE AFTERNOON. WILL HAVE LOW CHANCE POPS FOR THE WESTERN TIER OF
COUNTIES WITH A SLIGHT CHANCE EAST TO ROUGHLY A CLEVELAND TO
MANSFIELD LINE. MONDAY NIGHT WENT A BIT ABOVE POP GUIDANCE AND
BROUGHT CHANCE POPS EAST ACROSS THE REMAINDER OF THE AREA GIVEN
DEEP MOISTURE...OVERRUNNING FLOW AND JET ENERGY MOVING THROUGH THE
AREA. TUESDAY THROUGH WEDNESDAY LOW PRESSURE TO THE WEST WILL
SLOWLY MOVE EAST INCREASING MOISTURE AND INSTABILITY ACROSS THE
REGION. WILL BRING IN INCREASING CHANCE POPS FOR SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. TEMPS APPROACHING
NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
STILL UNCLEAR AT THIS POINT WHERE EXACTLY THE FRONT WILL STALL OUT
ON THURSDAY. A WEDGE OF DRY AIR ALOFT IS PULLED OVER THE AREA BUT
ENOUGH LOW LEVEL MOISTURE MAY REMAIN FOR SCATTERED
SHOWERS/THUNDERSTORMS TO DEVELOP FROM CENTRAL TO NORTHEAST OHIO IN
THE VICINITY OF THE BOUNDARY. CHANCES WILL BE LOWER BY FRIDAY
ALTHOUGH CAN NOT ENTIRELY RULE OUT SOMETHING POPPING UP AS MODELS
CONTINUE TO STRUGGLE WITH RESOLVING SHORTWAVE ENERGY MOVING AROUND
THE SOUTHERN PERIPHERY OF THE TROUGH. THE UPPER LOW WILL TRAVERSE
THE UPPER GREAT LAKES FRIDAY NIGHT INTO SATURDAY AND FINALLY PUSH A
STRONGER COLD FRONT SOUTH ACROSS THE AREA. TEMPERATURES WILL DROP
FROM NEAR 80 ON THURSDAY TO THE LOWER 70S ON SUNDAY.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED OVER LAKE
ERIE AND WILL MOVE THROUGH CLE BY 07Z. CONDITIONS WILL BRIEFLY DROP
TO MVFR AND POSSIBLY IFR FOR A FEW MINUTES IN MODERATE TO HEAVY
RAIN. ELSEWHERE CONDITIONS ARE EXPECTED TO REMAIN VFR BUT SCT-BKN
CLOUDS ARE EXPECTED AS COLD ADVECTION INCREASES BEHIND THE FRONT.
SATELLITE IMAGERY SHOWS ONE BAND OF CLOUDS OVER LAKE ERIE WITH
ANOTHER BAND OF CLOUDS ACROSS CENTRAL MICHIGAN PUSHING SOUTHEAST.
WINDS WILL REMAIN OUT OF THE NORTH THROUGH THE AFTERNOON BEFORE
BECOMING LIGHT AND VARIABLE AFTER 00Z.
.OUTLOOK...NON-VFR POSSIBLE IN SHOWERS/STORMS MONDAY NIGHT AND
AGAIN WEDNESDAY INTO THURSDAY.
&&
.MARINE...
WAVES WILL BUILD THIS MORNING AS NORTHERLY WINDS OF 10 TO 20 KNOTS
CONTINUE ON THE LAKE BEHIND A COLD FRONT. WAVES WILL REACH 2 TO 4
FEET EAST OF AVON AND WILL HAVE TO MONITOR CONDITIONS FOR THE NEED
FOR A SMALL CRAFT ADVISORY. THIS WILL ALSO PRESENT A MODERATE RISK
FOR RIP CURRENTS FOR AREAS EAST OF THE ISLANDS. HIGH PRESSURE OVER
THE UPPER MIDWEST WILL BUILD EAST ACROSS THE LAKE OVERNIGHT THROUGH
MONDAY BRINGING LIGHT WIND AND GOOD MARINE CONDITIONS. SOUTHERLY
WIND WILL INCREASE FROM TUESDAY INTO WEDNESDAY AHEAD OF THE
NEXT LOW PRESSURE SYSTEM.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS TULSA OK
1132 PM CDT SAT AUG 3 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
CONVECTION CONTINUES TO GRADUALLY EXPAND INTO NE OK...AND THIS
TREND IS EXPECTED TO CONTINUE THROUGH THE OVERNIGHT HOURS.
EVENTUALLY WIDESPREAD CONVECTION IS EXPECTED ACROSS NE OK / FAR NW
AR WITH ASSOCIATED AVIATION IMPACTS. FLIGHT CONDITION ARE LIKELY
TO IMPROVE AREA WIDE BY MID AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 848 PM CDT SAT AUG 3 2013/
..UPDATE...
DISCUSSION...
FORECAST IS LARGELY ON TRACK...WITH THE MAIN CHANGES BEING TO
SPEED UP THE INCREASE IN POPS TONIGHT AND EARLY TOMORROW BY ABOUT
3 HOURS IN ACCORDANCE WITH THE LATEST OBSERVATIONAL AND MESOSCALE
MODEL DATA. THE LATEST HRRR HAS A FAIRLY GOOD HANDLE ON THE
ONGOING STORMS ACROSS THE OKLAHOMA AND TEXAS PANHANDLES...AND INTO
NORTHWEST OKLAHOMA. THIS ACTIVITY SHOULD CONTINUE TO INCREASE
OVERNIGHT AND TRACK TO THE EAST AND SOUTHEAST ALONG THE
INSTABILITY AXIS NEAR AND JUST SOUTH OF THE OKLAHOMA/KANSAS
BORDER. ALTHOUGH SOME OF THE FLASH FLOOD WATCH AREA /NAMELY THE
ARKANSAS COUNTIES/ MAY NOT SEE HEAVY RAIN UNTIL AFTER 12Z...IT
APPEARS INCREASINGLY LIKELY THAT PARTS OF THE NORTHEAST OKLAHOMA
WATCH AREA WILL SEE RAINS BEFORE THEN. DUE TO THIS...THE WATCH
WILL NOW BEGIN AT 09Z. RAINFALL AMOUNTS STILL LOOK TO BE IN THE 1
TO 2 INCH RANGE ACROSS THE WATCH AREA...WITH LOCALLY HIGHER
AMOUNTS. RELATIVELY MINOR TWEAKS WERE MADE TO OTHER FORECAST
ELEMENTS.
PREV DISCUSSION... /ISSUED 625 PM CDT SAT AUG 3 2013/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
ONGOING LIGHT CONVECTION ACROSS NE OK WILL LIKELY CONTINUE THROUGH
THE EVENING WITH LITTLE TO NO FLIGHT IMPACTS. A LARGE THUNDERSTORM
COMPLEX IS EXPECTED TO MOVE INTO NE OK LATE TONIGHT...AND CONTINUE
INTO NW AR AROUND SUNRISE WITH CORRESPONDING AVIATION IMPACTS
PERSISTING INTO THE AFTERNOON.
PREV DISCUSSION... /ISSUED 326 PM CDT SAT AUG 3 2013/
DISCUSSION...
OVERNIGHT/EARLY MORNING MCS PROVED TO BE AN EFFICIENT
RAINMAKER...WITH 3+ INCH RAINFALL AMOUNTS AND LOCALIZED FLOODING
REPORTED ACROSS NW AR. ONLY A FEW LINGERING SHOWERS NOTED ACROSS THE
FORECAST AREA AT THIS TIME...BUT EXPECT YET ANOTHER BOUT OF
SHOWERS/THUNDERSTORMS LATE TONIGHT AND INTO TOMORROW.
SHORT-RANGE GUIDANCE IS SIMILAR KEYING ON A SUBTLE MID-LEVEL
SHORTWAVE ACROSS THE CNTRL ROCKIES ROUNDING THE TOP OF THE RIDGE AND
MOVING INTO KS LATE TONIGHT. EXPECT DEVELOPMENT TO OCCUR IN
ASSOCIATION WITH THIS FEATURE LATER THIS AFTERNOON/EVENING ACROSS
PARTS OF WRN KS...WITH VEERING LOW-LEVEL JET AIDING AN EWD/SEWD
MOVEMENT INTO FAR NE OK/NW AR BY SUNDAY MORNING. WITH PRECIP WATER
VALUES REMAINING AT OR ABOVE 2 INCHES...EXPECT LOCALLY HEAVY RAINFALL
ACROSS SOME AREAS THAT HAVE ALREADY RECEIVED SEVERAL INCHES OF RAIN
OVER THE PAST 5-10 DAYS. WILL GO WITH A FLASH FLOOD WATCH FOR SUNDAY
FOR FAR NERN OK AND NW AR. WATCH MAY NEED TO BE EXTENDED INTO SUNDAY
NIGHT WITH FORECAST AREA REMAINING UNDER NWLY UPPER FLOW.
UPPER RIDGE EXPANDS SOME BY EARLY NEXT WEEK...WITH LOW-LEVEL FLOW
BECOMING MORE SWLY. THIS WILL BRING IN WARMER AIR AND SHOULD
SHUNT MOST OF THE CONVECTION TO OUR N...ALTHOUGH WILL KEEP SOME LOW
POPS GOING ALONG THE NRN FRINGES OF THE FORECAST AREA. WILL LIKELY
NEED HEAT HEADLINES FOR MONDAY AND TUESDAY...WITH AFTERNOON HEAT
INDICES LIKELY BREACHING 105F ACROSS A LARGE PART OF THE AREA.
A WEAK FRONTAL BOUNDARY IS EXPECTED TO DROP INTO THE REGION
WEDNESDAY NIGHT AND LIKELY STALL NEAR THE RED RIVER FOR THE END OF
THE WEEK. ECMWF RATHER BULLISH WITH POST-FRONTAL PRECIP AND COOLER
TEMPS THURSDAY/FRIDAY...AND HAVE GONE WITH A GENERAL GFS/ECWMF BLEND
FOR NOW.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 74 92 76 98 / 60 80 30 10
FSM 76 92 73 97 / 20 50 40 30
MLC 75 97 76 99 / 20 20 20 10
BVO 74 87 74 97 / 80 80 40 10
FYV 71 87 73 92 / 40 70 50 40
BYV 69 85 71 91 / 40 80 50 40
MKO 74 91 74 98 / 30 50 30 20
MIO 72 85 73 94 / 70 80 50 30
F10 75 94 75 98 / 30 40 20 10
HHW 75 98 75 99 / 10 20 10 10
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH FROM 4 AM SUNDAY TO 7 PM SUNDAY FOR OKZ056-
OKZ057-OKZ058-OKZ063.
AR...FLASH FLOOD WATCH FROM 4 AM SUNDAY TO 7 PM SUNDAY FOR ARZ001-
ARZ002-ARZ010-ARZ011.
&&
$$
AVIATION...07
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
416 AM CDT SUN AUG 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN AUG 4 2013
MODELS STRUGGLING WITH ONGOING ACTIVITY ACROSS CENTRAL SOUTH DAKOTA
WHICH HAS DEVELOPED WITH AN INCREASING LOW LEVEL JET AND MID LEVEL
WAVE. DRY AIR TO THE EAST AND MINIMAL INSTABILITY IS EXPECTED TO
CAUSE A DOWNWARD TREND IN THIS CONVECTION AS IT ENTERS OUR CWA. OF
ALL THE GUIDANCE...SEEMS LIKE HRRR IS CLOSEST TO REALITY...WITH THE
0Z ECMWF ALSO NOT TOO BAD. BOTH OF THESE MODELS SUGGEST ACTIVITY
DOES INDEED WEAKEN AND DISSIPATE AS IT PUSHES EAST. HAVE HIGH CHANCE
TO LIKELY POPS THIS MORNING WEST OF THE JAMES RIVER...FROM ABOUT 10Z
TO 15Z. NOTHING SEVERE BUT WOULD EXPECT AT LEAST SOME LIGHTNING
ACTIVITY WITH THE STORMS. SHOWERS COULD MAKE IT AS FAR EAST AS
INTERSTATE 29 BY 13Z...BUT NOT REAL CONFIDENT IT WILL HOLD TOGETHER
EVEN THAT FAR...SO WILL ONLY GO SLIGHT CHANCE POPS. PLUS GIVEN THE
EXPECTED WEAKENING STATE...AND LACK OF INSTABILITY...PROBABLY WILL
NOT BE ANY LIGHTNING WITH ANYTHING THAT DOES MANAGE TO GET EAST OF
THE JAMES RIVER. TEND TO THINK WE SEE A LULL IN THE ACTIVITY DURING
THE AFTERNOON HOURS. BUT GIVEN WEAK FORCING...MID LEVEL MOISTURE
PRESENT...ONGOING ACTIVITY CONTINUING TO DEVELOP OVER NORTHWEST
SOUTH DAKOTA...AND THE GENERALLY LOW PREDICTABILITY OF THE
PATTERN...WILL KEEP A LOW CHANCE POPS IN THE WEST THROUGH THE
DAY...WITH SLIGHT CHANCES TO INTERSTATE 29. DAY SHIFT MAY END UP
BEING ABLE TO REMOVE THESE IF IT BECOMES MORE APPARENT DURING THE
MORNING THAT WE SEE A LULL IN THE ACTION. HIGHS TODAY ARE TRICKY AND
DEPENDENT ON REMNANT CLOUD COVER. THINK IT PROBABLY STAYS MOSTLY
CLOUDY FOR MUCH OF THE DAY. DID BUMP HIGHS UP SOME WITH SOME OF THE
NEWER GUIDANCE COMING IN A BIT WARMER...BUT GIVEN CLOUD COVER
CONCERNS DID NOT WANT TO GO TOO WARM...AND WENT WITH MAINLY MID AND
UPPER 70S. IF WE SOMEHOW ARE ABLE TO GET MORE SUN TODAY...HIGHS
WOULD END UP SEVERAL DEGREES WARMER. SO ANOTHER THING THE DAY SHIFT
WILL HAVE TO MONITOR.
UNFORTUNATELY...FORECAST CONFIDENCE DOES NOT INCREASE TONIGHT. THE
CORE OF THE UPPER LEVEL SUPPORT WILL DIVE SOUTHEAST ACROSS
MINNESOTA. SEEMS LIKE A GOOD BET THAT WE SEE ANOTHER ROUND OF
NOCTURNAL CONVECTION ACROSS THE NORTHERN PLAINS. BEST FORCING IS TO
THE NORTHEAST...WITH BEST INSTABILITY AS YOU GO SOUTHWEST. THINK
THE BEST THREAT WILL BE ACROSS SOUTHWEST MINNESOTA CLOSEST TO THE
BEST FORCING...BUT GIVEN INSTABILITY TO THE SOUTHWEST...AND SOME OF
THE HI RES MODELS SHOWING CONVECTION FIRING IN OUR WEST...WILL KEEP
CHANCE POPS ACROSS THE WHOLE CWA. CONFIDENCE IS TOO LOW IN PLACEMENT
AND TIMING TO WARRANT ANY LIKELY POPS AT THIS TIME. ELEVATED
INSTABILITY AROUND 1000 J/KG TONIGHT WOULD SUGGEST A PRETTY GOOD
LIGHTNING THREAT WITH ANYTHING THAT DOES FORM TONIGHT...HOWEVER
SEVERE THREAT SHOULD REMAIN PRETTY LOW...WITH THE ELEVATED NATURE
LIMITING WIND THREAT...AND CAPE PROBABLY TOO LOW FOR MUCH OF A HAIL
THREAT. LOWS WILL BE MILDER TONIGHT...GENERALLY LOW AND MID 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN AUG 4 2013
FOR MONDAY...A COLD FRONT DROPS ACROSS THE REGION EARLY IN THE
DAY...AND OTHER THAN A SLIGHT CHANCE OF POPS IN THE SOUTH AND EAST
EARLY THINK THAT THE REMAINDER OF THE DAY WILL BE DRY IN
SUBSIDENCE/DRYING BEHIND AN EXITING SHORTWAVE. ONLY WEAK COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH MORE SUN THAN TODAY
TEMPERATURES WILL WARM INTO THE UPPER 70S TO MID 80S ACROSS THE AREA
BY AFTERNOON. MOSTLY CLEAR SKIES WILL RULE FOR THE FIRST HALF OF
MONDAY NIGHT...BEFORE CLOUDS BEGIN TO INCREASE IN THE WEST THE
LATTER HALF OF THE NIGHT WITH MID LEVEL WARM AIR ADVECTION. CANNOT
RULE OUT THAT ISOLATED THUNDERSTORMS COULD MAKE IT INTO OUR FAR WEST
BY EARLY TUESDAY MORNING WITH THETA E ADVECTION ON A DEVELOPING LOW
LEVEL JET THROUGH WESTERN SOUTH DAKOTA. LOWS ON MONDAY NIGHT LOOKING
TO BE IN THE UPPER 50S TO LOWER 60S.
ANOTHER COLD FRONT ENCROACHES ON OUR AREA BY TUESDAY AFTERNOON...AND
MAY HAVE BETTER CHANCE OF THUNDERSTORMS ACROSS THE AREA WITH
INCREASING 850 MB THETA E ADVECTION AND INCREASING INSTABILITY OUT
AHEAD OF THE SYSTEM...WITH UPPER LEVEL SUPPORT AS A SHORTWAVE TRACKS
OVER THE AREA. THEIR DOES APPEAR TO BE ENOUGH CAPE AND SHEAR IN OUR
SOUTH AND WEST IN THE AFTERNOON THAT SEVERE STORMS WOULD BE
POSSIBLE. THERMAL PROFILES WARM JUST A BIT OUT AHEAD OF THE
FRONT...THOUGH HIGHS WILL BE DEPENDENT ON TIMING AND EVOLUTION OF
CONVECTION...BUT POTENTIALLY WILL REACH THE UPPER 70S TO MID 80S.
THE FRONTAL BOUNDARY WILL FINALLY PULL ACROSS THE AREA ON TUESDAY
EVENING WITH ANY CONVECTION ENDING FROM WEST TO EAST.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT
AGREEMENT ON THE DEVELOPMENT OF A CLOSED UPPER LEVEL LOW OVER
CENTRAL CANADA FOR MIDWEEK. THIS FEATURE WILL THEN SLOWLY MIGRATE TO
THE NORTHERN GREAT LAKES REGION BY THE END OF THE WEEK. THIS WILL
KEEP OUR AREA IN A NORTHWESTERLY UPPER LEVEL FLOW WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD. DOES NOT APPEAR TO BE ANY
OUTSTANDING CHANCES OF PRECIPITATION THROUGH THE EXTENDED...THOUGH
THE BEST CHANCE WOULD LOOK TO BE IN THE THURSDAY TO THURSDAY NIGHT
TIME FRAME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1055 PM CDT SAT AUG 3 2013
LOOKING FOR CONVECTION OVER THE WESTERN HIGH PLAINS THIS EVENING TO
SPREAD EAST ACROSS SD THROUGH THE DAY SUNDAY. MAIN QUESTION WILL BE
HOW MUCH CONTINUED ADVECTION OF DRY LOW LEVEL AIR FROM THE EAST TO
SOUTHEAST WILL HAMPER EASTWARD EXPANSION OF THE PRECIPITATION. WILL
KEEP A MENTION OF SHOWERS AT KHON FOR THE LATE MORNING THROUGH MID
AFTERNOON...BUT LATEST MODELS SEEM TO INDICATE BETTER CHANCE OF DRY
AIR WINNING OUT AT KFSD/KSUX WITH BETTER UPPER LEVEL SUPPORT FOR
PRECIPITATION SPLITTING AROUND THOSE LOCATIONS. WITH THIS LEVEL OF
UNCERTAINTY INTRODUCED BY EVENING MODEL RUNS...WILL KEEP KFSD/KSUX
FREE OF PRECIP WITH THIS ISSUANCE. INSTABILITY...EVEN ELEVATED...
PRETTY MEAGER FOR START OF PRECIPITATION AT KHON...SO WILL CONTINUE
WITH JUST SHOWER MENTION FOR NOW. INSTABILITY DOES RAMP UP LATER IN
THE AFTERNOON/EVENING...SO THUNDER POTENTIAL COULD INCREASE LATER IN
THE FORECAST PERIOD...BUT CONFIDENCE IN TIMING NOT HIGH ENOUGH TO
INCLUDE AT THIS TIME. PERIODS OF MVFR VISIBILITIES COULD ACCOMPANY
PRECIPITATION...BUT VFR CONDITIONS EXPECTED TO DOMINATE THROUGH THE
TAF PERIOD MOST AREAS.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...JM
AVIATION...JH
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
345 AM CDT SUN AUG 4 2013
.DISCUSSION...
A VERY WARM START TO THE MORNING AS MOST SITES ARE STILL IN THE
LOWER 80S. HEAT INDEX VALUES AT 3 AM RANGED FROM THE UPPER 80S TO
THE UPPER 90S (97 - KGLS). SURFACE HIGH PRESSURE WAS LOCATED OVER
THE CENTRAL GULF OF MEXICO WITH LOWER PRESSURE OVER SOUTHWEST
TEXAS. 850 MB TEMPS ARE A DEGREE COOLER THAN LAST NIGHT AND DEEPER
850 MB MOISTURE WAS OVER SOUTHWEST LOUISIANA. A 700 MB HIGH WAS
CENTERED OVER EASTERN OKLAHOMA AND DEEPER 700 MB MOISTURE WAS
AGAIN OVER SOUTHWEST LOUISIANA. 700 MB TEMPS HAD COOLED FURTHER AT
BOTH KLCH AND KSHV. A STRONG UPPER LEVEL HIGH REMAINS NEARLY
STATIONARY OVER WEST CENTRAL TEXAS. FCST SOUNDINGS FOR THIS AFTN
SHOW PW VALUES PEAKING NEAR 2.00 INCHES WITH K INDEX VALUES FROM
34 TO 38. THE HRRR... RAP AND 4 KM WRF ALL BRING SHRA/TSRA INTO SE
TX LATE THIS MORNING INTO THE AFTN. THE DEEPER MOISTURE TO THE
EAST WILL MOVE INTO SE TX LATER THIS MORNING. SHRA/TSRA ARE
EXPECTED TO DEVELOP THIS MORNING ONCE HEATING COMMENCES. STILL A
GREAT DEAL OF CONCERN THAT THE MAMMOTH UPPER RIDGE WILL IMPART
SUBSIDENCE AND THIS COULD LIMIT DEVELOPMENT. A FEW MORE CLOUDS AND
DEEPER MOISTURE WILL HINDER HEATING SO SHAVED A FEW DEGREES FROM
YESTERDAYS VALUES.
UPPER LEVEL RIDGING WILL REMAIN IN CONTROL FOR THE REST OF THE
WEEK. STILL SOME MOISTURE AROUND ON MONDAY BUT AS THE CENTER OF
THE UPPER RIDGE NUDGES CLOSER...FEEL SUBSIDENCE WILL END ANY
POTENTIAL FOR SHOWERS. 850 MB TEMPS SLOWLY WARM THROUGH THURSDAY
AND 850 MB WINDS VEER TO THE SOUTHWEST. TUE-THU CONTINUE TO LOOK
VERY WARM WITH 100 DEGREE HEAT RETURNING OR CONTINUING FOR MOST OF
THE AREA. HEAT INDEX VALUES LOOK TO GET NEAR ADVISORY CRITERIA
MID WEEK.
850 MB WINDS TURN TO THE SOUTHEAST ON FRIDAY AND THE UPPER RIDGE
RETREATS EVER SO SLIGHTLY. MOISTURE LEVELS WILL BEGIN TO DEEPEN SO
TRENDED MAX TEMPS SLIGHTLY COOLER FOR FRIDAY. A WEAK DISTURBANCE
MOVING INTO THE REGION FROM THE EAST WILL BRING THE AREA A SLIGHT
CHANCE OF RAIN ON SAT/SUN. THE RIDGE STILL LOOKS TOO STRONG AND
THE DISTURBANCE WILL PROBABLY BE SHUNTED SOUTH OF THE AREA. THAT
SAID...DEEPER MSTR WILL STILL FILTER INTO SE TX NEXT WEEKEND WITH
SLIGHTLY COOLER TEMPS AND A SLIGHT CHANCE OF RAIN. 43
&&
.MARINE...
ONSHORE WINDS EXPECTED TO CONTINUE WITH THE SURFACE RIDGE EXTENDING
ACROSS THE NORTHERN GULF OF MEXICO. THE THERMAL GRADIENT WILL HELP
TO GENERATE A DAILY CYCLE OF LIGHTER WINDS IN THE LATE MORNING TO
EARLY AFTERNOON AND MODERATE WINDS FROM THE LATE AFTERNOON THROUGH
THE EVENING. WITH A DEEPER LAYER OF MOISTURE AND A WEAK BOUNDARY
ABOVE THE SURFACE...DO EXPECT ISOLATED SHOWERS THIS MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 101 / 10 10 10 10 0
HOUSTON (IAH) 96 77 97 77 99 / 20 10 10 10 0
GALVESTON (GLS) 92 83 93 82 92 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1024 PM MDT SAT AUG 3 2013
.UPDATE...
ISSUED AT 708 PM MDT SAT AUG 3 2013
THUNDERSTORMS HAVE WEAKENED AND SO HAVE CANCELLED THE TORNADO
WATCH FOR THE SOUTHEAST WYOMING PLAINS. STILL SOME SHOWERS AND
STORMS OVER SOUTHEAST WYOMING EARLY THIS EVENING. THE ACTIVITY
HAS BEEN DECREASING IN COVERAGE AND INTENSITY AS IT TRIES TO
MOVE FURTHER EAST. THE ATMOSPHERE OVER THE PANHANDLE SHOULD
CONTINUE TO BE STABLE TONIGHT. LOW CLOUDS AND AREAS OF FOG WILL
BE LIKELY OVER THE EAST PART OF THE CWA TONIGHT WITH SOME
LOCATIONS ALREADY WITH LOW CLOUDS. IN A RECENT UPDATE...LOWERED
POPS OVER THE PANHANDLE FOR EARLY TONIGHT AND INCREASED CLOUD
COVER OVER THE EAST PART OF THE CWA.
UPDATE ISSUED AT 344 PM MDT SAT AUG 3 2013
LONG TRACKED SEVERE THUNDERSTORM CONTINUES TO HOLD TOGETHER AND
MOVE NORTH INTO NORTHERN LARAMIE COUNTY. WENT AHEAD AND ADDED
PLATTE AND GOSHEN COUNTIES TO THE TORNADO WATCH AS THIS STORM
COULD PRODUCE SEVERE THUNDERSTORMS THERE. PLUS THE ENVIRONMENT IS
PROBABLY BETTER UP THERE FOR MORE WIDESPREAD THUNDERSTORM
DEVELOPMENT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 300 PM MDT SAT AUG 3 2013
FORECAST CHALLENGES DEAL WITH THUNDERSTORM TIMING AND LOCATION OF
SEVERE THUNDERSTORMS THIS AFTERNOON THROUGH EVENING HOURS.
CURRENTLY...BOUNDARY LAYING ALONG THE LARAMIE RANGE EARLY THIS
AFTERNOON...SEPARATING FAIRLY DRY AIR TO THE WEST FROM REALLY
MOIST AIR TO THE EAST. DEWPOINTS IN LARAMIE IN THE MID 30S...HERE
AT CHEYENNE WE ARE SEEING UPPER 50S AND OUT BY SIDNEY...MID 60
DEWPOINTS. STRATUS HAS BEEN SLOW TO BREAK UP LATE THIS
MORNING/EARLY THIS AFTERNOON. STILL GETTING REPORTS OF STRATUS IN
THE PANHANDLE AND AS FAR WEST AS TORRINGTON. CHEYENNE HAS REMAINED
UNDER MOSTLY SUNNY SKIES AND CUMULUS HAS BEGUN TO BUILD OVER THE
SOUTHERN LARAMIE RANGE...EXTENDING SOUTH INTO THE MOUNTAINS OF
COLORADO. GETTING OBSERVED LIGHTNING STRIKES OVER CENTRAL
COLORADO...BUT SO FAR...THE CHEYENNE CWFA HAS REMAINED PRETTY MUCH
ECHO FREE. MONSOONAL MOISTURE CONTINUES TO MOVE INTO SOUTH CENTRAL
WYOMING ON WATER VAPOR IMAGERY...MAINLY OVER SOUTHERN CARBON AND
ALBANY COUNTIES THROUGH THE MORNING HOURS.
DO BELIEVE ITS ONLY A MATTER OF TIME FOR CONVECTION TO INITIATE
THIS AFTERNOON. LATEST SPC MESOANALIST PAGE SHOWING SURFACE BASED CAPE
VALUES INCREASING TO AROUND 3500 J/KG JUST SOUTH OF THE CWFA IN
COLORADO WITH AROUND 2500 TO 3000 J/KG JUST NUDGING INTO THE SOUTH
LARAMIE RANGE. STILL SEEING SOME CONVECTIVE INHIBITION EAST OF
CHEYENNE...SPREADING NORTH AND EAST. SPC MESOANALYST PAGE SHOWING
STILL AROUND 100-150 J/KG CONVECTIVE INHIBITION FOR THESE AREAS.
CURRENTLY THINKING AND THIS IS BACKED UP BY LATEST HRRR FORECASTS
IS THAT CONVECTION WILL INITIATE JUST WEST OF CHEYENNE...THEN
SLOWLY SPREAD EAST AND NORTH AS THE CAP ERODES.
MAIN THREATS WITH THUNDERSTORMS TODAY LOOKS TO BE LARGE HAIL AND
DAMAGING WINDS. BULK SHEAR ON THE ORDER OF 40 TO 45KTS. BUT LATER
THIS AFTERNOON...NAM SOUNDINGS ARE SHOWING HELICITY VALUES
INCREASING ABOVE 200 M2/S2 FOR CHEYENNE AND THE SOUTHERN
PANHANDLE...SO CAN NOT RULE OUT SOME TORNADIC SUPERCELLS LATE THIS
AFTERNOON AND EARLY EVENING. LCLS PRETTY LOW...WITH NAM FORECASTING
ANYWHERE FROM 2K TO 3K AGL. FINALLY...HEAVY RAIN IS A CONCERN WITH
PWATS CLIMBING TO OVER 1 INCH HERE AT CHEYENNE AND 1.4 INCHES OUT
BY SIDNEY. STORM MOTIONS ARE FAIRLY SLOW...GENERALLY OUT OF THE
WEST AT LESS THAN 10KTS...SO WE COULD BE LOOKING AT A FLASH FLOOD
THREAT AS WELL IN AREAS THAT SEE TRAINING STORMS. STORMS SHOULD
CONTINUE INTO THE MID TO LATE EVENING HOURS...SPREADING INTO THE
PANHANDLE BY 6 PM OR SO TONIGHT.
FOR SUNDAY...MODELS INDICATING A REPEAT OF TODAYS WEATHER WITH
POSSIBLY CONVECTION FURTHER EAST INTO THE PANHANDLE INITIALLY.
SEVERE THUNDERSTORMS LOOK MORE OUT OVER THE PANHANDLE SUNDAY VS
INITIATING HERE IN SOUTHEAST WYOMING.
.LONG TERM...(TUESDAY THROUGH SATURDAY)
ISSUED AT 320 PM MDT SAT AUG 3 2013
MAIN FORECAST CONCERN THROUGH NEXT WEEK WILL BE A STRONG MID
SUMMER COLD FRONT PUSHING ACROSS THE GREAT PLAINS AND INTO THE
FORECAST AREA...AS THE DEEP 543DM UPPER LEVEL LOW SETTLES OVER
SOUTHERN CANADA NEAR THE GREAT LAKES REGION. THIS IS PRETTY
UNUSUAL FOR THIS TIME OF THE YEAR...ALTHOUGH THE ROCKY MOUNTAIN
REGION WILL NOT SEE THE MAJORITY OF THIS COOLER AIR. MODELS SHOW
THIS FRONT QUICKLY MOVING ACROSS THE AREA TUESDAY AND TUESDAY
EVENING WITH HIGH TEMPERATURES AROUND 10 TO 15 DEGREES COOLER ON
WEDNESDAY AND THURSDAY. WITH SUBTROPICAL MONSOON MOISTURE IN
PLACE...A DAILY CHANCE OF SHOWERS AND THUNDERSTORMS IS ANTICIPATED
ACROSS MOST OF THE FORECAST AREA. THE BEST CHANCE WILL REMAIN OVER
THE MOUNTAINS AND ALONG/EAST OF THE LARAMIE RANGE...PRIMARILY FROM
MID AFTERNOON THROUGH EARLY IN THE EVENING. SOME OF THESE SHOWERS
MAY CONTINUE INTO THE OVERNIGHT HOURS...ESPECIALLY WEDNESDAY AND
THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY EVENING)
ISSUED AT 1024 PM MDT SAT AUG 3 2013
SHOWERS AND THUNDERSTORMS HAVE JUST ABOUT ENDED OVER THE CWA LATE
THIS EVENING. ACTIVITY WILL DEVELOP ONCE AGAIN EARLY SUNDAY
AFTERNOON AND CONTINUE THROUGH THE EVENING. THE STORMS WILL BE
MOST WIDESPREAD OVER THE WESTERN NEBRASKA PANHANDLE. IFR CEILINGS
AND MVFR VISIBILITIES IN FOG CAN BE EXPECTED INTO LATE MORNING
SUNDAY OVER THE WESTERN NEBRASKA PANHANDLE. THOSE CONDITIONS WILL
BE POSSIBLE OVER THE EASTERN PANHANDLE LATE SUNDAY NIGHT AND INTO
MID MORNING MONDAY.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MDT SAT AUG 3 2013
LIGHT WINDS AND MONSOONAL MOISTURE SHOULD KEEP FIRE WEATHER ISSUES
AT BAY FOR TODAY AND SUNDAY. AREAS EAST OF THE LARAMIE RANGE
SHOULD SEE CONTINUED GOOD CHANCES AT WETTING RAINS...HIGH
HUMIDITIES AND EASTERLY UPSLOPING WINDS. AREAS WEST WILL SEE DRIER
CONDITIONS WITH AFTERNOON HUMIDITIES FALLING INTO MID TEENS.
FORTUNATELY...WINDS SHOULD STAY LIGHT OUT THAT WAY KEEPING FIRE
WEATHER CONCERNS MINIMAL. BY MONDAY...SURFACE HIGH PRESSURE MOVING
INTO NORTH CENTRAL COLORADO WILL RE-ESTABLISH WESTERLY WINDS WITH
DRIER AIR FILTERING IN TO AREAS EAST OF THE LARAMIE RANGE. WINDS
WILL REMAIN LIGHT THOUGH...WHICH WILL KEEP FIRE WEATHER MINIMIZED.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
UPDATE...WEILAND
SHORT TERM...CLAYCOMB
LONG TERM...TJT
AVIATION...WEILAND
FIRE WEATHER...CLAYCOMB
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1020 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A FALL-LIKE AIRMASS HAS BEGUN TO OVERSPREAD THE REGION AND WILL
CONTINUE TO DO SO INTO THE EARLY PORTION OF THIS WEEK. CONDITIONS
WILL BE MORE TYPICAL OF SEPTEMBER THAN AUGUST. DRY WEATHER LIKELY
MONDAY THROUGH WEDNESDAY OF NEXT WEEK THEN BECOMING UNSETTLED
WEDNESDAY NIGHT INTO THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
EVALUATING THE HRRR AND OTHER NEAR-TERM MODEL GUIDANCE...
EXPECTING SHOWERS AND ISOLATED THUNDERSTORMS. ACTIVITY MAY BE
DELAYED TILL MID- TO LATE-AFTERNOON BY A DRY AIR INVERSION PER
THE 12Z ALBANY SOUNDING. CONSIDERING WEAK AND THIN INSTABILITY
PROFILES /ALLOWING DRY-AIR ENTRAINMENT INTO ANY UPDRAFT/ COUPLED
WITH A FAIRLY DRY SOUNDING /PWATS LESS THAN AN INCH/ AND AN
INVERTED-V PROFILE AT THE SURFACE...ANY STORMS COULD HAVE THE
POTENTIAL OF PRODUCING A BRIEF HEAVY DOWNPOUR ALONG WITH GUSTY
WINDS. WITH THE WIDELY SCATTERED NATURE OF THE ACTIVITY...HAVE
REMOVED HEAVY RAIN AND GUSTY WIND WORDING FROM THE FORECAST. LOW
CONFIDENCE ON HAIL POTENTIAL.
FEEL ACTIVITY WILL BE CENTERED ON THE REGION WITH BEST MID-LEVEL
LAPSE RATES AND LOW-LEVEL FORCING...PRESENTLY ALONG THE WEAK
TROUGH AXIS OVER UPSTATE NY INTO NORTHERN NEW ENGLAND. LOW-LEVEL
CONVERGENCE POPPING THROUGH A WEAKENING DRY-AIR INVERSION /SEE 12Z
BUFFALO SOUNDING/ AND BOUNDARY LAYER DESTABILIZATION ALREADY
YIELDING SOME SCATTERED ACTIVITY SOUTH AND EAST OF LAKE ONTARIO.
THIS IS COLLOCATED WITH A WEAK WAVE DISTURBANCE AND ENHANCED
ASCENT ALONG THE H5 FLOW /PRESENTLY ENTERING THE ADIRONDACKS/
WHILE SCATTERED SHOWERS MAY DEVELOP AROUND 1 TO 2 PM...AM
EXPECTING THE BULK OF THE ACTIVITY WITHIN THE BETTER REGION OF
LIFT TO PRESS INTO THE NORTHERN AND CENTRAL NEW ENGLAND AROUND 3
TO 4 PM MOVING EAST AND OFFSHORE INTO EVENING. GREATER THREATS OF
HEAVY DOWNPOURS AND GUSTY WINDS MAY REMAIN ALONG AND NORTH OF THE
MASSACHUSETTS TURNPIKE...LOWER CONFIDENCE SOUTH.
TEMPERATURES...DEWPOINTS...AND SKY GRIDS LOOK TO REMAIN ON TRACK.
FEEL THE RAP IS DOING WELL IN HANDLING CLOUD COVER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
SUNDAY...
*** A FALL-LIKE AIRMASS ARRIVES TONIGHT INTO MONDAY ***
NOTABLE COLD AIR ADVECTION TONIGHT...WITH 850 MB TEMPERATURE
REACHING +6C TO +8C BY 12Z MONDAY. LATEST MOS GUIDANCE STILL
FORECASTING TEMPERATURES ABOUT 4-5 DEGREES ABOVE THE RECORD MIN
TEMPERATURES FOR AUGUST 5. WE DO EXPECT WINDS TO DIMINISH BRIEFLY
THIS EVENING...WHICH COULD LEAD TO SEVERAL HOURS OF DECENT
RADIATIONAL COOLING. AT THIS POINT...WE STILL THINK THESE RECORDS
ARE LIKELY OUT OF REACH BUT IT WILL BE CLOSE.
HIGH PRESSURE REACHES THE MID ATLANTIC COAST MONDAY EVENING...
PROVIDING DRY WEATHER TO OUR REGION. BELOW NORMAL TEMPERATURES
CONTINUE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* MOSTLY DRY...SEASONABLE TO SEASONABLY COOL WEATHER THROUGH TUE
* NEXT CHANCE OF WIDESPREAD RAIN THU
OVERVIEW AND MODEL PREFERENCES...
04/00Z EXTENDED MODEL GUIDANCE SUITE CONTINUES TO SHOW REASONABLY
GOOD SYNOPTIC SCALE AGREEMENT DESPITE THE TRANSITION TO A MORE
MERIDIONAL PATTERN FOR THE LATTER HALF OF THE WEEK. AS USUAL THERE
ARE STILL SOME MORE SUBTLE SUB-SYNOPTIC SCALE ISSUES THAT WILL
NEED TO BE RESOLVED WHICH WILL DICTATE EXACT TIMING/NATURE OF
SENSIBLE WX DETAILS...BUT GIVEN THE BROAD AGREEMENT...PREFER TO
STICK TO A GFS/ECMWF DETERMINISTIC BLEND AS EVEN THEIR RESPECTIVE
ENSEMBLES ARE CLOSELY ON BOARD WITH THE PATTERN.
SRN CONUS RIDGE WHICH WILL FORCE A LONGWAVE TROF DEEPER INTO
CANADA EARLY IN THE WEEK LOSES ITS GRIP IN RESPONSE TO STRONG
CUTOFF WHICH WILL SLIDE S AND E INTO THE GREAT LAKES FROM HUDSON
BAY TOWARD THE LATTER HALF OF THE WEEK. THEREFORE...A DRY AND COOL
PERIOD WILL TRANSITION TO A MORE WET...UNSETTLED AND WARMER
PATTERN LATE IN THE WORK WEEK. HOWEVER...AS THE TROF SLIDES AGAIN
TO THE E...WE MAY SEE ANOTHER ROUND OF DRY WX BY THE COMING
WEEKEND.
DETAILS...
MON NIGHT INTO EARLY WED...
HIGH PRES WILL GRADUALLY CREST OVER THE REGION THROUGH THE
PERIOD. THIS WILL DELIVER DRY CONDITIONS TO SRN NEW ENGLAND. H85
TEMPS BEGIN AROUND +7C THEN INCREASE GRADUALLY TO ABOUT +10C BY
EARLY WED. SO A COOL START WITH HIGHS ONLY BREAKING INTO THE
70S...WITH NIGHTS IN THE 40S TO 50S. TRANSITIONING TO HIGHS NEARER
TO THE LOW 80S BY WED.
WED NIGHT INTO FRI...
CUTOFF LOW AND ASSOCIATED SFC LOW PRES WILL SLIDE INTO SRN CANADA
INITIALLY DRAGGING AN OCCLUDING WARM AND COLD FRONTAL SYSTEM INTO
THE NORTHEAST. INITIALLY IT APPEARS THAT THE SFC WARM FRONT WILL
SLIDE N OF THE REGION ALLOWING SRN NEW ENGLAND INTO THE WARM
SECTOR...HOWEVER...SOME GUIDANCE NOW HAS SECONDARY LOW PRES
DEVELOPMENT IN THE VICINITY OF A POSSIBLE TRIPLE POINT.
THEREFORE...EXPECT THAT RAIN WITH SOME EMBEDDED THUNDER WILL MOVE
IN AHEAD OF THIS FRONT WED NIGHT. WHETHER OR NOT THERE IS MORE
THUNDER ON THU WILL BE DEPENDENT ON THIS SECONDARY LOW PRES
DEVELOPMENT AND IF THE CLOUDS CAN BREAK ENOUGH FOR DIURNAL
DESTABILIZATION. WILL CONTINUE TO CARRY SOME ISOLD THUNDER BUT
THIS WILL HAVE TO BE WATCHED GIVEN THE MITIGATING FACTORS IN
PLACE. WILL HAVE TO WATCH FOR HEAVY RAIN IN EITHER CASE
HOWEVER...GIVEN VERY HIGH PWATS /AROUND 2.0 INCHES/ AND DECENT
DYNAMICS. GUIDANCE DOES HAVE THIS FRONT SLOWING TO A NEAR STALL S
OF NEW ENGLAND FOR FRI...SO MORE CLOUDS AND POSSIBLE WET WX
LINGERS UNTIL HIGH PRES CAN NOSE IN BY FRI EVENING.
THIS COMING WEEKEND...
WILL LEAN A BIT FURTHER AWAY FROM THE MOST RECENT GFS WITH THIS
UPDATE FOR THE WEEKEND...MAINLY DUE TO ITS RECENT INSISTENCE OF
MORE WET WX DESPITE HIGH PRES...NW FLOW AND COLD ADVECTION. WILL
LEAN MORE ON THE DRY ECMWF FOR ANOTHER PERIOD OF DRY WX WITH TEMPS
NEAR NORMAL FOR MID AUGUST.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
MODERATE CONFIDENCE TODAY
A DRY START...VFR DOMINATES MOST OF THE DAY. MAY BE BRIEF MVFR/IFR
DIP IN VSBYS AND CIGS IN SOME SCT -SHRA/TSRA THIS AFTERNOON. SEA
BREEZE AND INCOMING TROUGH MAY PROVIDE A FOCUS FOR THIS. LOW
CONFIDENCE ON EXACT TIMING OR HOW FAR INLAND SEA BREEZE GETS.
TONIGHT AND MONDAY...ANY LEFTOVER EARLY EVENING SHOWERS/TSTMS
ACROSS EASTERN MA WILL DISSIPATE AND/OR DRIFT OFFSHORE. VFR AND
DRY WEATHER THEN PREVAIL WITH AN INCREASING WNW WIND LATE EVENING.
HIGH CONFIDENCE.
KBOS TERMINAL...HIGH CONFIDENCE IN MAINLY VFR. LOWER CONFIDENCE ON
EXACT TIMING OR IF SEA BREEZE WILL EFFECT TERMINALS. AN AFTERNOON
SHOWER OR THUNDERSTORM MAY ALSO EFFECT THE TERMINAL THIS AFTERNOON.
HIGHEST PROBABILITY FOR SEABREEZE IS FOR 16-18Z START THEN WNW
WINDS SHOULD DOMINATE.
KBDL TERMINAL...MODERATE CONFIDENCE IN TAF...MAINLY DUE TO TIMING
AND COVERAGE OF AFTERNOON SHOWER OR THUNDERSTORM POTENTIAL.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
MONDAY NIGHT THROUGH EARLY WEDNESDAY...HIGH CONFIDENCE.
VFR.
WEDNESDAY NIGHT INTO THURSDAY...MODERATE TO HIGH CONFIDENCE.
MVFR/IFR CONDITIONS LIKELY IN SHRA/TSRA/FOG. IMPROVEMENT TO VFR
POSSIBLE AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
HIGH CONFIDENCE.
TODAY...VARIABLE WINDS AHEAD OF THE NEXT FRONT. SCT SHOWERS/TSTMS
NEAR SHORE DURING THIS AFTERNOON...THEN DIMINISHING WITH SUNSET.
TONIGHT...WINDS BECOME NW 15-20 KT WITH HIGHER GUSTS POSSIBLE.
GOOD VSBY.
MONDAY...NW WINDS SLOWLY DIMINISH AND SHIFT MORE WEST DURING THE
AFTERNOON. GOOD VSBY.
OUTLOOK...MONDAY NIGHT THROUGH THURSDAY...
HIGH CONFIDENCE INTO WED...LOWER CONFIDENCE LATE WED AND THU.
MOSTLY QUIET BOATING WEATHER EXPECTED MONDAY NIGHT THROUGH
WEDNESDAY. SEAS START TO INCREASE TO AROUND 5-6 FEET ON THE OUTER
WATERS THURSDAY. MAINLY SOUTHWESTERLY WINDS WILL REMAIN BELOW 25
KTS FOR THE MOST PART THROUGH WED. THE WINDS THEN SHIFT TO THE
SOUTH WEDNESDAY NIGHT AND THURSDAY. WINDS INCREASE...GUSTING TO
AROUND 25 KTS ON THURSDAY. FOG...SHOWERS...AND THUNDERSTORMS WILL
LIMIT VISIBILITIES BEGINNING WEDNESDAY NIGHT.
&&
.CLIMATE...
RECORD LOWS FOR MONDAY AUGUST 5TH...
BOS...54...1972
PVD...51...1972
BDL...47...1972
ORH...48...1929
RECORD LOWS FOR TUESDAY AUGUST 6TH...
BOS...52...1883
PVD...50...1934
BDL...47...1957
ORH...45...1942
&&
.EQUIPMENT...
THE KBOX RADAR HAS BEEN PLACED ON STANDBY PENDING WEATHER FOR
LATER TODAY. FAILURES ON THE AIR CIRCULATION SYSTEMS HAVE RESULTED
IN THE RADAR EQUIPMENT ROOM TO OVERHEAT THEREBY TRIGGERING A RADAR
SHUT DOWN. KEEPING THE EQUIPMENT COOL FOR NOW WILL ALLOW LATER USE
OF THE RADAR FOR TODAY WITH ANY WEATHER. THE RADAR IS EXPECTED TO
REMAIN ON STANDBY DURING ANY QUIET WEATHER FOR AN INDETERMINATE
AMOUNT OF TIME DUE TO THE AFOREMENTIONED FAILURES.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...BELK/DOODY
NEAR TERM...SIPPRELL
SHORT TERM...BELK
LONG TERM...DOODY
AVIATION...BELK/DOODY
MARINE...BELK/DOODY
CLIMATE...SIPPRELL
EQUIPMENT...SIPPRELL
AREA FORECAST DISCUSSION
NWS ALBANY NY
945 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT MOVES
ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS ARE
POSSIBLE...BUT MOST OF THE TIME IT SHOULD REMAIN DRY. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT...SHOWERS HAD DISSIPATED TO THE EAST OF LAKE
ONTARIO. HOWEVER...ANOTHER CLUSTER HAS DEVELOPED IN ONEIDA COUNTY.
CLOUDS WERE BEGINNING TO PERCOLATE AS THE MID LEVELS OF THE
ATMOSPHERE COOL...STEEPENING THE LOW LEVEL LAPSE AND INSTABILITY.
ALSO...H20 WATER VAPOR LOOP INDICATES A SERIES OF DISTURBANCES
HEADING WAY LATER TODAY.
FOR ALL THESE REASONS...WILL KEEP CHANCE SHOWER/THUNDER WITH THE
MENTION OF SMALL HAIL WITH THIS PACKAGE. HOURLY TEMPERATURES WERE
GENERALLY RUNNING 3 DEGREES OR HIGHER THAN THE PREVIOUSLY PROJECTED
HOURLY TEMPS SO WENT AHEAD RE-TOOLED. DID RAISE A FEW TEMPERATURES
2-3 DEGREES...MAINLY IN THE MID HUDSON VALLEY. OTHERWISE LEFT THEM
ALONE.
LOOK FOR HIGH TEMPERATURES 70 TO 75 VALLEY AREAS...UPPER 70S MID
HUDSON VALLEY BUT ONLY IN THE 60S ACROSS THE ELEVATED TERRAIN. A
BREEZE WILL PICK UP FROM THE NORTHWEST 10 TO 15 MPH...GUSTING TO 25
OR MORE IN MORE WIND PRONE AREAS. THE RUC13 SUGGESTS SBCAPES AROUND
1K J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...A CLEARING SKY THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
WHILE THERE WERE SOME BRIEF PERIODS OF IFR FOG AT KGFL/KPOU...THIS
SHOULD DISSIPATE BEFORE THE START OF THE TAF PERIOD. THIS WILL ALLOW
FOR VFR CONDITIONS AT ALL TAF SITES...WITH JUST FEW-SCT LOW AND MID
LEVEL CLOUDS...WITH SCT-BKN HIGH LEVEL CIRROSTRATUS AS WELL.
AS AN UPPER LEVEL DISTURBANCE MOVES NORTH OF THE REGION TODAY...SOME
SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE REGION...MAINLY
FROM THE CAPITAL REGION NORTHWARD AND DURING THE AFTN HOURS.
COVERAGE WILL ONLY BE ISOLD-SCT SO WE WILL HANDLE THIS WITH JUST A
VCSH FOR KALB/KPSF/KGFL. IF ANY LOCATION DOES SEE A SHOWER OR
THUNDERSTORM...A VERY BRIEF PERIOD OF MVFR CONDITIONS COULD
POTENTIALLY OCCUR...ALTHOUGH CONFIDENCE IN THIS OCCURRING AT ANY
SPECIFIC TIME IS TOO LOW TO INCLUDE IN THE TAF AT THIS POINT.
OTHERWISE...SCT-BKN CLOUDS OF 5-7 KFT WITH BE IN PLACE ALONG WITH
SOME MID LEVEL CLOUDS AS WELL AND CONTINUED VFR CONDITIONS. WESTERLY
WINDS WILL PICK UP TO AROUND 10 KTS...WITH A FEW HIGHER GUSTS AT
KALB/KPSF.
WINDS WILL DECREASE WITH THE LOSS OF HEATING BY EVENING...AND AS THE
DISTURBANCE MOVE AWAY...THE THREAT FOR SHOWERS/TSTMS WILL END AS
WELL. ANY BKN CLOUDS WILL BREAK UP...AND SKIES SHOULD GO CLEAR AT
ALL SITES BY MIDNIGHT. SOME BR MAY DEVELOP TOWARDS MIDNIGHT AT KGFL
AND POSSIBLY KPSF AS WELL. THE THREAT WILL BE EVEN HIGHER IF ANY
PRECIP FALLS AT ANY OF THESE TERMINALS DURING THE DAY TODAY. IFR FOG
MAY OCCUR AT KGFL JUST PRIOR TO SUNRISE MONDAY...AND WE WILL HAVE TO
MONITOR KPSF FOR THE POTENTIAL OF THIS AS WELL. WINDS TONIGHT WILL
BE CALM TO LIGHT AT ALL SITES.
OUTLOOK...
MONDAY THROUGH TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY THROUGH THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS/JPV
FIRE WEATHER...FRUGIS
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
805 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT
MOVES ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS ARE
EXPECTED...BUT MOST OF THE TIME IT SHOULD REMAIN DRY. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 AM EDT...A FEW SHOWERS HAVE EVOLVED DOWNWIND OF LAKE
ONTARIO EXTENDING INTO THE WESTERN MOHAWK VALLEY. H2O VAPOR LOOP
CLEARLY DEFINES THE LEADING EDGE OF THE APPROACHING SHORT WAVE
TROUGH APPROACHING THE NIAGARA FRONTIER AND EXPERIMENTAL
REFLECTIVITY FORECASTS SUGGEST WIDELY SCATTERED CONVECTION
DEVELOPING LATER THIS MORNING. NEW RUC13 SUGGESTS SBCAPES AROUND 1K
J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST. THE
MAIN CHANGE WAS TO END POPS/WX A LITTLE SOONER PER TIMING OF THE
UPSTREAM TROUGH AND RUC13 FORECASTS. REMAINDER OF THE FORECAST
REMAINS IN GOOD SHAPE...
REGIONAL RADAR MOSAIC IS RATHER QUIET AS OF 300 AM
EDT...ALTHOUGH...SOME HINTS OF MID LEVEL ECHOES INCREASING
DOWNWIND OF LAKE ONTARIO. THIS IS DUE TO THE COLD ADVECTION MOVING
ACROSS WATER TEMPERATURES INTO THE LOWER 70S AS THOSE DELTA T/S
ARE ON THE INCREASE. SURFACE ANALYSIS REVEALS THE COLD FRONT WAS
JUST NORTH OF LAKE ONTARIO WITH A FEW TROUGHS THAT MESOSCALE
MODELS SUGGEST WILL TRACK THROUGH THE REGION TODAY. SBCAPES ARE
EXPECTED TO BE AROUND 1000 J/KG WITH DROPPING WET BULB ZERO
HEIGHTS AND RATHER STEEP LOW-MID LEVEL LAPSE RATES TO CONTINUE THE
MENTION FOR ISOLATED-SCATTERED CONVECTION WITH SOME SMALL HAIL. IN
FACT...THE LATEST H2O VAPOR LOOP REVEALS THE LEADING EDGE OF THIS
COLDER AIR DIVING SOUTHWARD ACROSS THE UPPER GREAT LAKES SO WE
WILL CONTINUE WITH A SCT-BKN SKY FORECAST AND TEMPERATURES A GOOD
5 DEGREES COOLER THAN YESTERDAY. WEST-NORTHWEST WINDS WILL ALSO BE
ON THE INCREASE WITH A TIGHTENING PRESSURE GRADIENT AND MIXING
LAYER HEIGHTS CLIMBING WELL INTO THE H800 LAYER WHERE 20KTS
RESIDES. HIGHS TODAY GENERALLY IN THE MID 60S TO MID 70S.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...CLEARING SKIES THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
WHILE THERE WERE SOME BRIEF PERIODS OF IFR FOG AT KGFL/KPOU...THIS
SHOULD DISSIPATE BEFORE THE START OF THE TAF PERIOD. THIS WILL ALLOW
FOR VFR CONDITIONS AT ALL TAF SITES...WITH JUST FEW-SCT LOW AND MID
LEVEL CLOUDS...WITH SCT-BKN HIGH LEVEL CIRROSTRATUS AS WELL.
AS AN UPPER LEVEL DISTURBANCE MOVES NORTH OF THE REGION TODAY...SOME
SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE REGION...MAINLY
FROM THE CAPITAL REGION NORTHWARD AND DURING THE AFTN HOURS.
COVERAGE WILL ONLY BE ISOLD-SCT SO WE WILL HANDLE THIS WITH JUST A
VCSH FOR KALB/KPSF/KGFL. IF ANY LOCATION DOES SEE A SHOWER OR
THUNDERSTORM...A VERY BRIEF PERIOD OF MVFR CONDITIONS COULD
POTENTIALLY OCCUR...ALTHOUGH CONFIDENCE IN THIS OCCURRING AT ANY
SPECIFIC TIME IS TOO LOW TO INCLUDE IN THE TAF AT THIS POINT.
OTHERWISE...SCT-BKN CLOUDS OF 5-7 KFT WITH BE IN PLACE ALONG WITH
SOME MID LEVEL CLOUDS AS WELL AND CONTINUED VFR CONDITIONS. WESTERLY
WINDS WILL PICK UP TO AROUND 10 KTS...WITH A FEW HIGHER GUSTS AT
KALB/KPSF.
WINDS WILL DECREASE WITH THE LOSS OF HEATING BY EVENING...AND AS THE
DISTURBANCE MOVE AWAY...THE THREAT FOR SHOWERS/TSTMS WILL END AS
WELL. ANY BKN CLOUDS WILL BREAK UP...AND SKIES SHOULD GO CLEAR AT
ALL SITES BY MIDNIGHT. SOME BR MAY DEVELOP TOWARDS MIDNIGHT AT KGFL
AND POSSIBLY KPSF AS WELL. THE THREAT WILL BE EVEN HIGHER IF ANY
PRECIP FALLS AT ANY OF THESE TERMINALS DURING THE DAY TODAY. IFR FOG
MAY OCCUR AT KGFL JUST PRIOR TO SUNRISE MONDAY...AND WE WILL HAVE TO
MONITOR KPSF FOR THE POTENTIAL OF THIS AS WELL. WINDS TONIGHT WILL
BE CALM TO LIGHT AT ALL SITES.
OUTLOOK...
MONDAY THROUGH TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY THROUGH THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS/JPV
FIRE WEATHER...FRUGIS
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
620 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT
MOVES ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS ARE
EXPECTED...BUT MOST OF THE TIME IT SHOULD REMAIN DRY. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY
NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 615 AM EDT...A FEW SHOWERS HAVE EVOLVED DOWNWIND OF LAKE
ONTARIO EXTENDING INTO THE WESTERN MOHAWK VALLEY. H2O VAPOR LOOP
CLEARLY DEFINES THE LEADING EDGE OF THE APPROACHING SHORT WAVE
TROUGH APPROACHING THE NIAGARA FRONTIER AND EXPERIMENTAL
REFLECTIVITY FORECASTS SUGGEST WIDELY SCATTERED CONVECTION
DEVELOPING LATER THIS MORNING. NEW RUC13 SUGGESTS SBCAPES AROUND 1K
J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST. THE
MAIN CHANGE WAS TO END POPS/WX A LITTLE SOONER PER TIMING OF THE
UPSTREAM TROUGH AND RUC13 FORECASTS. REMAINDER OF THE FORECAST
REMAINS IN GOOD SHAPE...
REGIONAL RADAR MOSAIC IS RATHER QUIET AS OF 300 AM
EDT...ALTHOUGH...SOME HINTS OF MID LEVEL ECHOES INCREASING
DOWNWIND OF LAKE ONTARIO. THIS IS DUE TO THE COLD ADVECTION MOVING
ACROSS WATER TEMPERATURES INTO THE LOWER 70S AS THOSE DELTA T/S
ARE ON THE INCREASE. SURFACE ANALYSIS REVEALS THE COLD FRONT WAS
JUST NORTH OF LAKE ONTARIO WITH A FEW TROUGHS THAT MESOSCALE
MODELS SUGGEST WILL TRACK THROUGH THE REGION TODAY. SBCAPES ARE
EXPECTED TO BE AROUND 1000 J/KG WITH DROPPING WET BULB ZERO
HEIGHTS AND RATHER STEEP LOW-MID LEVEL LAPSE RATES TO CONTINUE THE
MENTION FOR ISOLATED-SCATTERED CONVECTION WITH SOME SMALL HAIL. IN
FACT...THE LATEST H2O VAPOR LOOP REVEALS THE LEADING EDGE OF THIS
COLDER AIR DIVING SOUTHWARD ACROSS THE UPPER GREAT LAKES SO WE
WILL CONTINUE WITH A SCT-BKN SKY FORECAST AND TEMPERATURES A GOOD
5 DEGREES COOLER THAN YESTERDAY. WEST-NORTHWEST WINDS WILL ALSO BE
ON THE INCREASE WITH A TIGHTENING PRESSURE GRADIENT AND MIXING
LAYER HEIGHTS CLIMBING WELL INTO THE H800 LAYER WHERE 20KTS
RESIDES. HIGHS TODAY GENERALLY IN THE MID 60S TO MID 70S.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...CLEARING SKIES THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
WHILE THERE WERE SOME BRIEF PERIODS OF IFR FOG AT KGFL/KPOU...THIS
SHOULD DISSIPATE BEFORE THE START OF THE TAF PERIOD. THIS WILL ALLOW
FOR VFR CONDITIONS AT ALL TAF SITES...WITH JUST FEW-SCT LOW AND MID
LEVEL CLOUDS...WITH SCT-BKN HIGH LEVEL CIRROSTRATUS AS WELL.
AS AN UPPER LEVEL DISTURBANCE MOVES NORTH OF THE REGION TODAY...SOME
SHOWERS AND THUNDERSTORMS WILL DEVELOP ACROSS THE REGION...MAINLY
FROM THE CAPITAL REGION NORTHWARD AND DURING THE AFTN HOURS.
COVERAGE WILL ONLY BE ISOLD-SCT SO WE WILL HANDLE THIS WITH JUST A
VCSH FOR KALB/KPSF/KGFL. IF ANY LOCATION DOES SEE A SHOWER OR
THUNDERSTORM...A VERY BRIEF PERIOD OF MVFR CONDITIONS COULD
POTENTIALLY OCCUR...ALTHOUGH CONFIDENCE IN THIS OCCURRING AT ANY
SPECIFIC TIME IS TOO LOW TO INCLUDE IN THE TAF AT THIS POINT.
OTHERWISE...SCT-BKN CLOUDS OF 5-7 KFT WITH BE IN PLACE ALONG WITH
SOME MID LEVEL CLOUDS AS WELL AND CONTINUED VFR CONDITIONS. WESTERLY
WINDS WILL PICK UP TO AROUND 10 KTS...WITH A FEW HIGHER GUSTS AT
KALB/KPSF.
WINDS WILL DECREASE WITH THE LOSS OF HEATING BY EVENING...AND AS THE
DISTURBANCE MOVE AWAY...THE THREAT FOR SHOWERS/TSTMS WILL END AS
WELL. ANY BKN CLOUDS WILL BREAK UP...AND SKIES SHOULD GO CLEAR AT
ALL SITES BY MIDNIGHT. SOME BR MAY DEVELOP TOWARDS MIDNIGHT AT KGFL
AND POSSIBLY KPSF AS WELL. THE THREAT WILL BE EVEN HIGHER IF ANY
PRECIP FALLS AT ANY OF THESE TERMINALS DURING THE DAY TODAY. IFR FOG
MAY OCCUR AT KGFL JUST PRIOR TO SUNRISE MONDAY...AND WE WILL HAVE TO
MONITOR KPSF FOR THE POTENTIAL OF THIS AS WELL. WINDS TONIGHT WILL
BE CALM TO LIGHT AT ALL SITES.
OUTLOOK...
MONDAY THROUGH TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY THROUGH THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS/JPV
FIRE WEATHER...BGM
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
920 AM CDT Sun Aug 4 2013
...UPDATE TO SYNOPSIS...
.SYNOPSIS...
ISSUED AT 912 AM CDT SUN AUG 4 2013
A weak upper level ridge of high pressure remains situated across
the western high plains and the south plains of west Texas. A
strong +110kt upper level jet is streaming southeast out of the
western Great Lakes Region into the upper Ohio River Valley. Near
the surface, a large area of high pressure is drifting slowly east
across the upper midwest. Ample low level moisture remains across
central and southwest Kansas with surface dewpoints mainly in the
mid to upper 60s(F).
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 321 AM CDT SUN AUG 4 2013
Precipitation chances will remain high through the early morning
hours in most areas across southwest Kansas, and at least moderate
into the late morning and afternoon. The latest NAM model forecast
fields indicate segments of a disjointed 400 mb level PV anomaly
still rotating eastward along the upper ridge apex, which will
likely continue to set off heavy rain showers through the day.
We`ve increased shower chances to near 50 percent into the early
afternoon. The severe threat has been negligible and that trend is
continued to be expected. The shower and thunderstorms will remain
very efficient heavy rain producers in this tropical deep moist
convective environment.
The latest Nam maximum temperature forecast is far more reasonable
as well with the highs this afternoon; a range of around 80 degrees
near Hays to near 90 degrees near the Oklahoma panhandle. although
the atmosphere should be weakly conditionally unstable again tonight
the lack of forcing mechanisms and latest model precipitation field
support a generally low probability of significant convection.
.LONG TERM...(Monday through Saturday)
ISSUED AT 321 AM CDT SUN AUG 4 2013
Upper level ridge axis will weaken early next week as a upper level
disturbance moves out of the south central Canada and starts to
cross the northern plains. the GFS and ECMWF both were in decent
agreement with this upper level system crossing the plains Tuesday
night and Wednesday and as it does a cold front will move south
across Kansas. Moisture convergence along this front along with
improving upper level dynamics ahead of the 500mb trough/right
entrance region of a 250mb jet supports the improving chances for
convection Tuesday night into early Wednesday. This boundary is
forecast to moving into Oklahoma on Thursday as an ridge of high
pressure at the surface builds into the central plains. Given the
warm air advection and isentropic lift north of this front on
Thursday will favor the latest CRExtendFcst_Init with chance/slight
chance for precipitation. As the ridge of high pressure late builds
into Kansas late week the chances may decrease, however given some
uncertainty on the location of where the front will be late week
along with any moisture upslope flow north of this front am
reluctant to remove all mention of precipitation just yet.
As for temperatures next week...the warming trend Monday and Tuesday
still looks on track given the 850mb temperature trend. Behind the
cold front highs only in the 80s still appears reasonable.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 613 AM CDT SUN AUG 4 2013
VFR conditions will develop as showers and thunderstorms taper
off from west to east. Bufr soundings and HRRR both suggest low
level status will be possible with these thunderstorms and given
the 10z surface observations will keep these cigs in the ifr
category as these showers and thunderstorms pass. Given the latest
radar trend it appears precipitation will continue in/near the Hays
area until around 15z so will also keep status present until then.
further southwest VFR conditions were already observed at Dodge
and Garden City. The prevailing wind direction outside the early
morning thunderstorms will be southeast at 10 to 15kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 67 100 69 / 70 20 20 20
GCK 86 67 100 69 / 40 20 20 20
EHA 91 67 100 70 / 40 20 20 20
LBL 94 70 102 70 / 40 20 20 20
HYS 83 68 93 69 / 60 20 30 30
P28 89 70 99 73 / 90 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JJOHNSON
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
615 AM CDT Sun Aug 4 2013
...UPDATED AVIATION DISCUSSION...
.SYNOPSIS...
ISSUED AT 321 AM CDT SUN AUG 4 2013
Very heavy rain producing thunderstorms were anchored along a 300k
level isentropic lift zone from near Scott City to near Pratt. The
heaviest rainfall fell along a narrow zone over central and eastern
Hodgeman county where dual pol radar estimates of as much as 5
inches fell. As of 2 am, the convection has become not as tied to
that narrow corridor and more scattered in nature. The mesoanalysis
indicated precipitable water across the area had increase to above
the 99th percentile at 2 inches at Dodge City.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 321 AM CDT SUN AUG 4 2013
Precipitation chances will remain high through the early morning
hours in most areas across southwest Kansas, and at least moderate
into the late morning and afternoon. The latest NAM model forecast
fields indicate segments of a disjointed 400 mb level PV anomaly
still rotating eastward along the upper ridge apex, which will
likely continue to set off heavy rain showers through the day.
We`ve increased shower chances to near 50 percent into the early
afternoon. The severe threat has been negligible and that trend is
continued to be expected. The shower and thunderstorms will remain
very efficient heavy rain producers in this tropical deep moist
convective environment.
The latest Nam maximum temperature forecast is far more reasonable
as well with the highs this afternoon; a range of around 80 degrees
near Hays to near 90 degrees near the Oklahoma panhandle. although
the atmosphere should be weakly conditionally unstable again tonight
the lack of forcing mechanisms and latest model precipitation field
support a generally low probability of significant convection.
.LONG TERM...(Monday through Saturday)
ISSUED AT 321 AM CDT SUN AUG 4 2013
Upper level ridge axis will weaken early next week as a upper level
disturbance moves out of the south central Canada and starts to
cross the northern plains. the GFS and ECMWF both were in decent
agreement with this upper level system crossing the plains Tuesday
night and Wednesday and as it does a cold front will move south
across Kansas. Moisture convergence along this front along with
improving upper level dynamics ahead of the 500mb trough/right
entrance region of a 250mb jet supports the improving chances for
convection Tuesday night into early Wednesday. This boundary is
forecast to moving into Oklahoma on Thursday as an ridge of high
pressure at the surface builds into the central plains. Given the
warm air advection and isentropic lift north of this front on
Thursday will favor the latest CRExtendFcst_Init with chance/slight
chance for precipitation. As the ridge of high pressure late builds
into Kansas late week the chances may decrease, however given some
uncertainty on the location of where the front will be late week
along with any moisture upslope flow north of this front am
reluctant to remove all mention of precipitation just yet.
As for temperatures next week...the warming trend Monday and Tuesday
still looks on track given the 850mb temperature trend. Behind the
cold front highs only in the 80s still appears reasonable.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 613 AM CDT SUN AUG 4 2013
VFR conditions will develop as showers and thunderstorms taper
off from west to east. Bufr soundings and HRRR both suggest low
level status will be possible with these thunderstorms and given
the 10z surface observations will keep these cigs in the ifr
category as these showers and thunderstorms pass. Given the latest
radar trend it appears precipitation will continue in/near the Hays
area until around 15z so will also keep status present until then.
further southwest VFR conditions were already observed at Dodge
and Garden City. The prevailing wind direction outside the early
morning thunderstorms will be southeast at 10 to 15kts.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 85 68 100 69 / 80 20 20 20
GCK 86 68 100 69 / 90 20 20 20
EHA 91 68 100 70 / 40 20 20 20
LBL 94 71 101 70 / 40 20 20 20
HYS 83 70 93 69 / 90 20 30 30
P28 89 71 99 73 / 80 20 20 20
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RUSSELL
SHORT TERM...RUSSELL
LONG TERM...BURGERT
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
903 AM EDT SUN AUG 4 2013
.SYNOPSIS...
AFTER A FEW MORNING SHOWERS...DRY AND COOL WEATHER CAN BE EXPECTED FOR THE
START OF THE NEW WEEK AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY
REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
DENSE FOG ADZY HAS BEEN ALLOWED TO EXPIRE AS SCHEDULED. PREV
DISCUSSION FOLLOWS...
7AM UPDATE. ADDED DENSE FOG TO WESTMORELAND FAYETTE GARRETT TUCKER
AND PRESTON COUNTIES. ADDED DENSE FOG ADVISORY TILL 9AM FOR THESE COUNTIES.
PREVIOUS DISCUSSION...
NR DAWN UPDATE WAS ISSUED TO ADJUST FOR HOURLY TRENDS OF
TEMP AND PCPN PROBABILITY.
FEW SHOWERS THAT HAVE FORMED N OF I 80 ALNG A SFC TROF/WEAK
SECONDARY FRONT HAVE SAGGED SWD THIS MRNG TWD THE METRO AREA.
SLGT TO CHC POPS WERE THUS MAINTAINED PAST DAWN IN ACCORDANCE
WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /13Z SUNDAY THROUGH THURSDAY/...
IFR FOG IN THE SOUTH TO BEGIN THE FORECAST. ELSEWHERE GENERAL VFR
WITH MID-DECK AND AN ISO NON-RESTRICTIVE SHOWER.
VFR FORECAST FOR ALL PORTS SHORTLY AFTER DAWN WITH BKN-OVC CU
EXPECTED THROUGH THE REST OF THE DAY.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NO WIDESPREAD IFR
WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED BY TUESDAY
NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY NIGHT
THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
UPDATE...KRAMAR
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
708 AM EDT SUN AUG 4 2013
.SYNOPSIS...
AFTER A FEW MORNING SHOWERS...DRY AND COOL WEATHER CAN BE EXPECTED FOR THE
START OF THE NEW WEEK AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY
REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
7AM UPDATE. ADDED DENSE FOG TO WESTMORELAND FAYETTE GARRETT TUCKER
AND PRESTON COUNTIES. ADDED DENSE FOG ADVISORY TILL 9AM FOR THESE COUNTIES.
PREVIOUS DISCUSSION...
NR DAWN UPDATE WAS ISSUED TO ADJUST FOR HOURLY TRENDS OF
TEMP AND PCPN PROBABILITY.
FEW SHOWERS THAT HAVE FORMED N OF I 80 ALNG A SFC TROF/WEAK
SECONDARY FRONT HAVE SAGGED SWD THIS MRNG TWD THE METRO AREA.
SLGT TO CHC POPS WERE THUS MAINTAINED PAST DAWN IN ACCORDANCE
WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /11Z SUNDAY THROUGH THURSDAY/...
IFR FOG IN THE SOUTH TO BEGIN THE FORECAST. ELSEWHERE GENERAL VFR
WITH MID-DECK AND AN ISO NON-RESTRICTIVE SHOWER.
VFR FORECAST FOR ALL PORTS SHORTLY AFTER DAWN WITH BKN-OVC CU
EXPECTED THROUGH THE REST OF THE DAY.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NO WIDESPREAD IFR
WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED BY TUESDAY
NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY NIGHT
THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR MDZ001.
OH...NONE.
PA...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR PAZ073>076.
WV...DENSE FOG ADVISORY UNTIL 9 AM EDT THIS MORNING FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
657 AM EDT SUN AUG 4 2013
.SYNOPSIS...
AFTER A FEW MORNING SHOWERS...DRY AND COOL WEATHER CAN BE EXPECTED FOR THE
START OF THE NEW WEEK AS HIGH PRESSURE SETTLES OVER THE UPPER OHIO VALLEY
REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
7AM UPDATE. ADDED DENSE FOG TO WESTMORELAND FAYETTE GARRETT TUCKER
AND PRESTON COUNTIES.
PREVIOUS DISCUSSION...
NR DAWN UPDATE WAS ISSUED TO ADJUST FOR HOURLY TRENDS OF
TEMP AND PCPN PROBABILITY.
FEW SHOWERS THAT HAVE FORMED N OF I 80 ALNG A SFC TROF/WEAK
SECONDARY FRONT HAVE SAGGED SWD THIS MRNG TWD THE METRO AREA.
SLGT TO CHC POPS WERE THUS MAINTAINED PAST DAWN IN ACCORDANCE
WITH LATEST RUC GUIDCANCE AND RADAR TRENDS.
OTHERWISE...SFC HIGH PRES UNDR NW FLOW ALOFT WL SETTLE OVR THE
GREAT LAKES AND UPR OH REGIONS TDA. CONVECTIVE THRESHOLDS ARE
EXPECTED TO BE EXCEEDED BY LATE MRNG...HENCE STRATOCU/CU DVLPMNT
SHOULD BE SUFFICIENTLY EXTENSIVE FOR AT LEAST A BROKEN CLOUD DECK.
THE PROGGED MIXING LAYER APPEARS SUFFICIENTLY SHALLOW TO PRECLUDE
SHOWER DVLPMNT THIS AFTN...SO A DRY FORECAST WL BE INITIALLY
RETAINED. DUE TO THE EXPANSE IN CLOUD COVER...TEMPS ARE FORECAST
ABOUT 10 DEGREES BELOW SEASONAL AVERAGES.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
SHRTWV IN THE NW FLOW THAT IS NAM AND GFS PROJECTED ACRS THE
GREAT LAKES LTR ON MONDAY...WL REINITIATE WARM ADVCTN WITH THE
ADVN TWD THE UPR OH VALLEY. A SLIGHT...LATE DAY SHWR CHC WAS
INCLUDED FOR ZONES FM PIT SWD...WHERE SOME WEAK ELEVATED
CONVECTION MAY DVLP TO THE N OF THE SLOWLY RTNG SFC BNDRY.
RAIN CHCS THEREAFTER WL GRADUALLY INCRS THROUGH THE SHORT TERM PD
AS WARM FRONT SURGES NWD UNDR A SERIES OF CROSSING DISTURBANCES.
THE WARM ADVCTN REGIME WL QUICKLY MODERATE SHORT TERM TEMPS CLOSE
TO THE SEASONAL AVERAGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
GFS AND ECMWF RMN IN GENL AGRMNT IN DVLPG A DEEP UPR LOW OVR
MANITOBA BY MIDWEEK...THEN PR0JECTING IT TWD/ACRS JAMES BAY BY THE
WEEKEND. EWD PROGRESS OF THE LOW WL SEND A CDFNT ACRS THE AREA...HENCE
THE POP INCRS FOR THU...ALTHOUGH A DEEP MSTR SURGE IS NOT ANTICIPATED
GIVEN THE ENTRENCHMENT OF A BROAD RIDGE OVR THE GULF COAST STATES.
POST FRONTAL TEMPS WERE FORECAST CONSERVATIVELY...JUST A FEW
DEGREES UNDR THE AVERAGES FOR NXT WEEKEND.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
IFR FOG IN THE SOUTH TO BEGIN THE FORECAST. ELSEWHERE GENERAL VFR
WITH MID-DECK AND AN ISO NON-RESTRICTIVE SHOWER.
VFR FORECAST FOR ALL PORTS SHORTLY AFTER DAWN WITH BKN-OVC CU
EXPECTED THROUGH THE REST OF THE DAY.
OUTLOOK.../SUNDAY NIGHT THROUGH THURSDAY/... NO WIDESPREAD IFR
WEATHER IS PREDICTED. PATTERN BECOMES UNSETTLED BY TUESDAY
NIGHT...WITH A CHANCE OF SHOWERS/THUNDERSTORMS TUESDAY NIGHT
THROUGH THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
716 AM EDT SUN AUG 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 454 AM EDT SUN AUG 4 2013
NW FLOW ALOFT REMAINS IN PLACE BUT HEIGHTS ARE FLATTER ACROSS LK
SUPERIOR REGION COMPARED TO YESTERDAY. WV LOOP SHOWS RIBBON OF
DRYING WITH ENHANCED MOISTURE STAYING MOSTLY NORTH AND EAST OF
UPPER MICHIGAN. FLOW BECOMES MORE ZONAL FM PACIFIC NORTHWEST
THROUGH NORTHERN PLAINS INTO SOUTHERN PORTIONS OF ALBERTA AND
SASKATCHEWAN. MORE FORMIDABLE SHORTWAVE IS LOCATED HERE AND THAT
WAVE ALONG WITH SFC TROUGH AND ASSOCIATED WARM/MOIST ADVECTION IS
HELPING TO GENERATE CLUSTERS OF SHRA/TSRA FM SOUTHERN SASKATCHEWAN
THROUGH WESTERN DAKOTAS. THE SHORTWAVE AND SFC TROUGH APPROACH UPPER
LAKES REGION LATE TONIGHT AND COULD BRING SOME SHOWERS TO THE AREA.
MORE ON THAT LATER ON.
CURRENTLY OVER UPPER MICHIGAN...1026MB HIGH PRESSURE RIDGE CENTERED
OVER CENTRAL MINNESOTA IS TRYING TO RIDGE ACROSS WESTERN CWA. TEMPS
ARE AS COLD AS LOWER 40S THERE BUT ARE STILL INTO THE 50S ALONG LK
SUPERIOR AND OVER EASTERN HALF OF CWA. COOL/MOIST AIR AND LIGHT
WINDS OVER WEST RESULTING IN SOME FOG AS SEEN IN VSBY LESS THAN 3SM
AT IWD AND EGV THROUGH THE NIGHT. OTHERWISE...SKIES ARE MAINLY CLEAR
THOUGH STRATOCU IS HANGING TOUGH IN THE EAST CLOSER TO H9-H8 THERMAL
TROUGH. UPSTREAM SOUNDING AT CYPL SHOWED WELL MIXED LOWER BLYR WITH
SHALLOW LAYER OF MOISTURE AROUND 800MB/6KFT AND SUBSIDENCE INVERSION
BETWEEN H8-H7. CONVECTIVE TEMPS PRETTY LOW OVR CWA TODAY...MID-UPR
60S...SO THINK THIS MOISTURE WILL TURN INTO FAIRLY DECENT CU DECK BY
EARLY AFTN. SKIES COULD TURN MOSTLY CLOUDY FOR A TIME WHERE LAKE
BREEZE CONVERGENCE IS STRONGEST OVR CNTRL UPR MICHIGAN. GIVEN MORE
UNFAVORABLE LARGE SCALE SETUP FOR PRECIP WITH NO REAL SHORTWAVES
MOVING ACROSS AND WITH THERMAL TROUGHING EXITING THROUGH AFTN ALONG
WITH NOT AS MUCH MOISTURE DEPTH AS YESTERDAY...WILL GO WITH DRY
FORECAST TODAY. PER MODELED RADAR REFLECTIVITY ONLY THE LOCAL
RUM-WRF MODEL INDICATES POSSIBLY SEEING A SHRA WHILE HRRR SHOWS
LITTLE IN WAY OF SHRA DEVELOPMENT.
ATTN TONIGHT IS ON THE SHORTWAVE OVER SOUTHERN SASKATCHEWAN. EXPECT
THIS WAVE TO PUSH ACROSS NORTH DAKOTA THIS EVENING AND INTO NORTHEAST
MINNESOTA LATE TONIGHT. ANOTHER WAVE AND UPPER JETLET CURRENTLY
LIFTING ACROSS WESTERN MONTANA SLIDES TO CENTRAL MINNESOTA LATER
TONIGHT. SFC-H85 TROUGH WORKS EAST INTO MINNESOTA BY LATE TONIGHT.
MAINLY H7 MOISTURE ADVECTION AND FRONTOGENESIS AHEAD OF THE WAVES
ALONG WITH H85 TEMPERATURE ADVECTION WILL BE MAIN SUPPORT FOR SHRA
TONIGHT. A LOT OF TSRA CURRENTLY OVER DAKOTAS BUT EDGE OF 1-6KM
MUCAPE STAYS WELL TO THE SOUTHWEST OF UPR MICHIGAN TO NOT INCLUDE
TSRA. GFS/NAM/ECMWF/GEM IN GENERAL AGREEMENT ABOUT TONIGHT...BUT
NAM AND ASSOCIATED HIGHER RESOLUTION MODELS THAT ARE INITIALIZED OFF
OF IT...ARE MORE AGGRESSIVE WITH SHRA DEVELOPMENT OVER UPR MICHIGAN
OVERNIGHT TONIGHT. DO THINK H85-H6 MOISTURE ADVECTION/LIFT AND WARM
AIR ADVECTION AT H85 IS ENOUGH TO INCLUDE SLIGHT CHANCES WORKING
FROM WEST TO CENTRAL CWA. BUMPED POPS UP LATE TO LOWER CHANCE TOWARD
OVER FAR SW...VCNTY OF IWD AND IRON RIVER...WITH CLOSER PROXIMITY TO
LARGER SCALE WAVES MOVING INTO THE UPPER LAKES REGION. H7-H5 MOISTURE
SHOULD INCREASE STEADILY FM WEST TO EAST TONIGHT...WHICH WILL AFFECT
MIN TEMPS. COLD SPOT WILL BE INTERIOR EAST CWA /MID 40S MIN TEMPS/
AS LONGER PERIOD OF CLEAR SKIES/MINIMUM OF PWAT RESULTS IN BETTER
RADIATIONAL COOLING. TEMPS OVER FAR WEST WILL ONLY FALL INTO THE MID
50S WITH MORE CLOUD COVER AND INCREASING RETURN FLOW AHEAD OF SFC
TROUGH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 454 AM EDT SUN AUG 4 2013
MEDIUM RANGE GUIDANCE IS IN GOOD AGREEMENT ON THE BIG PICTURE THRU
THIS WEEK. IN THE MEAN...A TROF IS EXPECTED TO REMAIN IN PLACE
GENERALLY FROM HUDSON BAY VCNTY TO THE GREAT LAKES...NEW ENGLAND AND
SE CANADA. MAIN FEATURE THAT WILL CONTROL THE WEATHER OVER THE UPPER
LAKES DURING THE LONG TERM IS THE ENERGY THAT HAS PEELED OFF THE
DEEP POLAR VORTEX OVER THE WRN ARCTIC AND IS NOW IN THE PROCESS OF
FORMING A MID LEVEL LOW OVER HUDSON BAY. FARTHER N...THE RIDGES OVER
WRN NAMERICA AND BTWN GREENLAND AND BAFFIN ISLAND WILL CONNECT
ACROSS NRN CANADA OVER THE NEXT DAY OR TWO...FORCING THE MID LEVEL
LOW TO MEANDER EVEN FARTHER S DURING THE WEEK. AT SOME POINT...IT
WILL PASS ACROSS THE UPPER GREAT LAKES/NRN ONTARIO LATE THIS WEEK.
END RESULT IS A CONTINUATION OF A GENERAL BELOW NORMAL TEMP REGIME
FOR UPPER MI OVER THE NEXT 7-10DAYS. WHILE SOME DAYS WILL SEE TEMPS
AROUND NORMAL...THE OVERALL PATTERN SUGGESTS THE POTENTIAL FOR SOME
CHILLY DAYS FOR EARLY AUG STANDARDS AS WELL. THIS IS ESPECIALLY TRUE
LATE WEEK WHEN THE MID LEVEL LOW PASSES AND BRINGS ITS ASSOCIATED
COLD AIR INTO THE AREA. AS FOR PCPN...THERE WILL BE INCREASING PCPN
CHANCES MON/TUE AND PROBABLY INTO WED MORNING AS SHORTWAVES EJECT
FROM A PACIFIC NW/SW CANADA TROF AND TRACK E ACROSS THE NRN CONUS
UNDERNEATH THE MID LEVEL LOW. UNSETTLED WEATHER MAY PUSH THRU THE
AREA AGAIN LATE WEEK DEPENDING ON TRACK OF THE MID LEVEL LOW ACROSS
THE UPPER LAKES AND/OR NRN ONTARIO AND DEPENDING ON WHETHER ANY
ADDITIONAL SHORTWAVES ROTATE AROUND THE LOW.
BEGINNING MON...ATTENTION WILL BE ON THE WELL-DEFINED SHORTWAVE
CURRENTLY OVER SRN SASKATCHEWAN. GIVEN THE PRONOUNCED NW FLOW THIS
MORNING OVER THE UPPER LAKES...IT WOULD SEEM THIS WAVE WON`T BE ABLE
TO MAKE A STRONG PUSH E TO UPPER MI. MODELS DO SHOW FLOW BACKING
WITH UPPER MI UNDER WNW FLOW MON...WHICH STILL SHOULD DIRECT THE
SHORTWAVE AND BULK OF FORCING ESE THRU WI AS DEPICTED BY DEEP LAYER
QVECTORS. THE AXIS OF INSTABILITY REMAINS WELL TO THE SW WITH EVEN
THE INSTABILITY GRADIENT TO THE SW OF HERE. THIS ALSO SUPPORTS THE
IDEA OF MAIN AREA OF PCPN PASSING BY TO THE S. THAT SAID...GIVEN THE
WELL-DEFINED LOOK OF THE SHORTWAVE...SOME PCPN WILL PROBABLY STILL
BRUSH UPPER MI MON AS INDICATED BY ALL MODEL GUIDANCE. IN THE END...
PREFER THE MORE LIMITED NORTHWARD PUSH OF PCPN SHOWN BY THE ECMWF
AND THE 4KM HIGH RES NAM NEST GIVEN ABOVE DISCUSSION. WITH
INSTABILITY AND INSTABILITY GRADIENT TO THE SW...THUNDER LOOKS
UNLIKELY AND WON`T BE MENTIONED. IF THERE IS ANY THUNDER...IT
SHOULD ONLY AFFECT AREAS TOWARD THE WI BORDER.
FCST FOR MON NIGHT IS FAIRLY UNCERTAIN. IT WOULD SEEM DRY WEATHER
SHOULD FOLLOW AS SHORTWAVE CONTINUES TO THE ESE. 850MB WAA AND 850MB
WINDS ARE WEAK (10-15KT)...CERTAINLY SUGGESTING MINIMAL POTENTIAL
FOR MORE ORGANIZED PCPN AREAS. HOWEVER...WITH CYCLONIC 850MB FLOW
AND HINTS OF ONE OR TWO SUBTLE TROFS IN THE WIND FIELD...WILL
MAINTAIN SCHC POPS FOR MUCH OF THE AREA THRU THE NIGHT.
ON TUE...UNUSUALLY DEEP MID LEVEL LOW FOR EARLY AUG WILL BE WOBBLING
S ROUGHLY ALONG THE NE MANITOBA/NRN ONTARIO BORDER. AS A RESULT...
FLOW WILL CONTINUE TO BACK ACROSS THE UPPER GREAT LAKES UNDER THE
EXPANDING CIRCULATION AROUND THE LOW. TO THE W...COMBINATION OF A
SHORTWAVE ROTATING AROUND THE MID LEVEL LOW AND A SHORTWAVE PICKED
UP FROM THE PACIFIC NW/SW CANADA WILL LEAD TO AN ORGANIZING COLD
FRONT MOVING ACROSS THE NRN PLAINS TUE. ORGANIZED PCPN ASSOCIATED
WITH FRONT SHOULD REMAIN W OF UPPER MI THRU TUE AFTN. ACROSS UPPER
MI...NAM/GFS SHOW MLCAPE INCREASING TO AROUND 500J/KG TUE. WITH
HINTS OF A SUBTLE SHORTWAVE PASSING ACROSS THE AREA...WILL INCLUDE
LOW CHC POPS FOR SHRA/TSRA.
AS WAS THE CASE YESTERDAY...MODELS STILL SUGGEST TUE NIGHT AS HAVING
THE BEST SHOT OF SHRA/TSRA AS COLD FRONT PASSES ACROSS UPPER MI TUE
NIGHT/WED MORNING. THERE ARE STILL SOME TIMING ISSUES TO SORT OUT AS
THE GFS/NAM HAVE FRONT OVER THE FAR ERN FCST AREA AT 12Z WED WHILE
THE ECMWF/GEM ARE ABOUT 6-9HRS SLOWER. THE TIMING UNCERTAINTY LEADS
TO LOWER CONFIDENCE IN PIN POINTING PERIOD OF HIGHER POPS. TAKING
INTO ACCOUNT GFS/ECMWF GUIDANCE OVER THE LAST DAY OR TWO...WILL
HEDGE FCST SLIGHTLY TOWARD THE SLOWER SOLUTION...WHICH RESULTS IN
HANGING ONTO HIGHER POPS OVER THE E INTO WED MORNING. IN THE WAKE OF
SHORTWAVE/COLD FRONT...DRY WEATHER WILL FOLLOW W TO E DURING THE DAY
WED.
PLENTY OF UNCERTAINTY REMAINS FOR THU/FRI/SAT REGARDING TIMING/TRACK
OF THE UNUSUALLY DEEP MID LEVEL LOW (500MB HEIGHTS MAY BE AROUND 2.5
STANDARD DEVIATIONS BELOW LONG TERM AVG). IF ANYTHING...THE LAST DAY
OR TWO OF GFS/ECMWF MODEL RUNS SUGGEST A TREND FOR A SLIGHTLY SLOWER
PROGRESSION OF THE MID LEVEL LOW ACROSS NRN ONTARIO DURING THE LAST
HALF OF THE WEEK. THIS SLOWER TREND RAISES THE PROSPECT FOR AT LEAST
ONE SHORTWAVE ROTATING AROUND THE LOW TO AFFECT UPPER MI. THE
PREDICTABILITY OF TIMING A WAVE ROTATING AROUND A MID LEVEL LOW 4 TO
6 DAYS OUT IN A MODEL RUN IS VERY LOW. FOR WHAT IT`S WORTH...LATEST
GUIDANCE SUGGESTS A SHORTWAVE MAY ROTATE THRU THE UPPER LAKES FRI...
PROVIDING THE POTENTIAL FOR SOME SHRA. TEMPS WILL TURN COOLER LATE
WEEK. IN FACT...THERE COULD BE AT LEAST 1 DAY OF WELL BELOW NORMAL
TEMPS WITH HIGHS POTENTIALLY ONLY IN THE MID 50S NEAR LAKE SUPERIOR
AND LOW/MID 60S INLAND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 711 AM EDT SUN AUG 4 2013
VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE FORECAST. HIGH
PRESSURE OVERHEAD TODAY RESULTS IN LIGHT WINDS...TAKING ON FAVORED
LAKE BREEZE DIRECTION BY THIS AFTN. MID CLOUDS INCREASE TONIGHT OUT
AHEAD OF APPROACHING DISTURBANCE AND SURFACE TROUGH. COULD BE ENOUGH
LOW-LEVEL MOISTURE ADVECTION TO FORM SOME SHOWERS LATE AT IWD SO
HAVE PUT IN A VCNTY SHRA. AT CMX AND SAW...ANY RAIN SHOULD HOLD OFF
TIL JUST BEYOND TAF PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 454 AM EDT SUN AUG 4 2013
THROUGH THIS FCST PERIOD...WINDS SHOULD BE NO HIGHER THAN 20KT WITH
GENERALLY A WEAK PRESSURE GRADIENT DOMINATING THE UPPER GREAT LAKES.
HOWEVER...WILL NEED TO CONTINUE WATCHING THE MID WEEK PERIOD AS A
PASSING COLD FRONT COULD LEAD TO STRONGER PRE FRONTAL AND ESPECIALLY
POST FRONTAL WINDS IN THE LATE TUE/WED TIME FRAME.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...ROLFSON
AVIATION...JLA
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
537 AM CDT SUN AUG 4 2013
.UPDATE...
AVIATION ADDED BELOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 317 AM CDT SUN AUG 4 2013
SFC HIGH PRESSURE OVERHEAD TO START TODAY HAS US STARTING OUT WITH
ANOTHER SEASONABLY COOL EARLY AUGUST MORNING. A QUICK LOOK AT WATER
VAPOR SHOWS THE CULPRIT FOR WHAT EVENTUALLY WILL BECOME CATEGORICAL
POPS TONIGHT AND THAT IS A PRETTY POTENT SHORT WAVE SPINNING ACROSS
FAR SW ALBERTA. THIS WAVE GENERATED SOME FAIRLY ROBUST CONVECTION
ACROSS MONTANA LAST NIGHT...WHICH IS NOW ACROSS THE WRN DAKOTAS. A
CONVECTIVELY INDUCED SHORT WAVE IS ASSOCIATED WITH THE DAKOTAS
ACTIVITY. THE DAKOTAS SHORTWAVE IS PROGGED BY THE RAP TO MOVE INTO
NRN MN BY THIS AFTERNOON. HOWEVER...IT WILL NOT BE BRINGING THE
ELEVATED INSTABILITY AND MOISTURE TRANSPORT WITH IT...SO THIS WAVE
WILL DO NOTHING MORE THAN GIVE US A CLOUDIER DAY THAN WHAT WAS SEEN
YESTERDAY. THE ALBERTA WAVE WILL FOLLOW ON THE HEELS OF THE DAKOTAS
WAVE FOR TONIGHT AND WILL BE THE IMPETUS FOR WHAT WILL LIKELY BE AN
ELEVATED MCS ACROSS MUCH OF THE ERN HALF MPX AREA TONIGHT.
FOR TODAY...AS THE SFC HIGH WORKS INTO THE GREAT LAKES...WE WILL
START GETTING INTO WEAK WAA...WITH 925-850 TEMPS LOOKING TO BE A FEW
DEGREES WARMER THAN YESTERDAY...ESPECIALLY ACROSS MN. HOWEVER...MORE
CLOUD COVER IS EXPECTED TODAY THAN YESTERDAY...WHICH SHOULD OFFSET
THIS SLIGHT WARMING...WITH HIGHS TODAY VERY SIMILAR TO SATURDAY AS A
RESULT. STILL HAVE SOME CHANCE POPS REMAINING OUT IN WRN MN THIS
AFTERNOON AS H85 MOISTURE TRANSPORT AND ELEVATED INSTABILITY
BEGIN WORKING INTO MN. BEST SIGNAL FOR PRECIP FOR TODAY LOOKS TO BE
ACROSS NRN MN...WHERE THE GFS/NAM ARE SHOWING SOME DECENT FGEN
DEVELOPING IN THE H85-H5 LAYER...WHICH IS ALSO AT THE NOSE OF THE
H85 MOISTURE TRANSPORT. THIS SHOULD GENERATE AN AREA OF SHOWERS
ACROSS NW MN THAT MAY BLEED INTO WEST CENTRAL MN AFTER 18Z...BUT
STILL SEEING BETTER SIGNAL DOWN HERE FOR PRECIP TONIGHT.
AS FOR TONIGHT...THOUGH SHEERING OUT SOME...THE ALBERTA WAVE WILL BE
MOVING ACROSS NRN MN TONIGHT AND WILL STILL BE STRONG ENOUGH TO
INDUCE A NOCTURNAL STRENGTHENING OF THE LLJ ACROSS MN. NAM/ECMWF/GFS
ALL FAIRLY SIMILAR WITH THE NOSE OF AN ENHANCED AREA OF 925-850
MOISTURE TRANSPORT COMING UP TO ABOUT I-94 FROM 6Z AND BEYOND. AS A
RESULT...HELD OFF ON ANY LIKELY OR HIGHER POPS UNTIL AFTER 6Z...WITH
HEAVIEST AXIS OF PRECIP TONIGHT EXPECTED FROM STC DOWN TOWARD
RST/LSE AND OVER TOWARD EAU. NO SEVERE WEATHER IS EXPECTED WITH THIS
ACTIVITY...BUT PLENTY OF ELEVATED INSTABILITY WILL BE PRESENT TO
ENSURE THESE SHOWERS COME IN THE FORM OF THUNDERSTORMS. AS FOR
PRECIP AMOUNTS...THIS FEATURE LOOKS TO BE TRANSIENT ENOUGH TO KEEP
ACTIVITY MOVING ALONG...BUT WITH PWATS INCREASING TO NEAR 1.5
INCHES...COULD CERTAINLY SEEN AN AXIS OR TWO OF 1 TO 2 INCH RAINFALL
AMOUNTS IF SOME CELL TRAINING OCCURS...THOUGH FOR THE MOST PART
RAINFALL AMOUNTS WILL LIKELY BE A HALF TO ONE INCH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 317 AM CDT SUN AUG 4 2013
SOME RESIDUAL PCPN FROM TONIGHT/S ACTIVITY SHOULD STILL BE
LINGERING OVER THE EASTERN PORTION OF THE AREA MONDAY MORNING.
HOWEVER... THE 850MB FRONTOGENESIS AND MOISTURE TRANSPORT QUICKLY
SHIFTS EAST OF THE AREA ON MONDAY ALONG WITH THE 305-310K
ISENTROPIC LIFT. SO... EXPECT THE MORE WIDESPREAD PCPN TO SHIFT TO
OUR EAST MONDAY MORNING... LEAVING MAINLY DRY CONDITIONS FOR THE
REMAINDER OF THE DAY. HOWEVER... NEGATIVE 850-500MB DIFFERENTIAL
THETA-E VALUES REMAIN IN PLACE THROUGH THE DAY... INDICATING THE
RESIDUAL CONVECTIVE INSTABILITY THAT WILL BE OVER THE AREA. WITH
NO LARGE SCALE FORCING... DON/T EXPECT MUCH PCPN AFTER MONDAY
MORNING... BUT THE LINGERING INSTABILITY COULD LEAD TO A FEW
SHRA/TSRA MONDAY AFTERNOON INTO MONDAY EVENING... PARTICULARLY
OVER THE NORTHERN AND EASTERN PORTION OF THE AREA WHERE BETTER
LAPSE RATES ARE SUGGESTED. THE ARW AND NMM HIGH RESOLUTION WINDOW
RUNS BOTH MANAGE TO DEVELOP SOME SCATTERED SHRA/TSRA MONDAY
AFTERNOON GIVEN THIS SCENARIO... SO KEPT SOME LOW CHANCE POPS
GOING TO ACCOUNT FOR THE POSSIBILITY.
CHANCES FOR MORE WIDESPREAD PCPN WILL RETURN FROM WEST TO EAST ON
TUESDAY AS THE MAIN FRONTAL BOUNDARY WORKS INTO THE AREA WHILE A
STRONG 500MB TROUGH DROPS SOUTH FROM CENTRAL CANADA TOWARD THE
UPPER GREAT LAKES. THERE APPEARS TO BE LESS IN THE WAY OF POTENTIAL
FOR SEVERE WEATHER IN COMPARISON TO EARLIER GUIDANCE... WITH THE
BETTER INSTABILITY STAYING SOUTH OF THE AREA... AND THE FRONTAL
BOUNDARY LOOKING TO BE MORE DIFFUSE AND LATER IN ITS ARRIVAL.
HOWEVER... DEEP LAYER SHEAR IS STILL PROGGED BY THE NAM AND GFS TO
BE AOA 40 KT TUESDAY AFTERNOON INTO TUESDAY EVENING... WITH SOME
MLCAPE VALUES AOA 1000 J/KG CERTAINLY STILL POSSIBLE. LOW LEVEL
SHEAR IS MINIMAL WITH LOW LEVEL WINDS LOOKING TO BECOME
SOUTHWESTERLY AHEAD OF THE FRONT GIVEN ITS ORIENTATION AND LACK OF
ANY DECENT PRESSURE FALLS. WITH THE BEST DYNAMIC FORCING TO OUR
NORTH AND THE BEST THERMODYNAMIC FORCING TO OUR SOUTH... DON/T
EXPECT TO SEE ANYTHING TOO SIGNIFICANT ACROSS OUR AREA AT THIS
POINT. THERE APPEARS TO BE SUFFICIENT INSTABILITY... LOW LEVEL
CONVERGENCE... AND DIFFERENTIAL DIVERGENCE TO GET SOME SHRA/TSRA
GOING... AND GIVEN THE DECENT DEEP LAYER SHEAR IT/S POSSIBLE FOR A
FEW NEAR-SEVERE STORMS... BUT ANYTHING OF SIGNIFICANCE LOOKS TO BE
TO OUR SOUTH AT THIS POINT.
HIGH PRESSURE WILL BUILD ACROSS THE AREA TUESDAY NIGHT INTO
WEDNESDAY... WITH DRY AND COOLER CONDITIONS EXPECTED TO PERSIST
INTO THURSDAY. ANOTHER COLD FRONT WILL MOVE ACROSS THE AREA
SOMETIME FROM LATE THURSDAY INTO FRIDAY... BRINGING A CHANCE FOR
SHRA/TSRA... ALTHOUGH THERE DOESN/T LOOK TO BE MUCH OPPORTUNITY
FOR MOISTURE TRANSPORT AHEAD OF IT. THE TIMING OF THIS NEXT FRONT
IS A GOOD 18 HOURS DIFFERENT BETWEEN THE GFS AND ECMWF... WITH THE
GFS BEING QUICKER. PLAYED THE TIMING IN THE MIDDLE OF THE TWO
SOLUTIONS AT THIS POINT RATHER THAN BLANKETING AN OVERLY LONG
PERIOD WITH CHANCE POPS. ONCE THIS FRONT PUSHES THROUGH WE/LL SEE
HIGH PRESSURE BUILD IN ACROSS THE AREA FOR SATURDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 520 AM CDT SUN AUG 4 2013
HIGH PRESSURE WILL SLIDE FROM MN THIS MORNING INTO THE GREAT
LAKES TONIGHT. RETURN FLOW WILL BECOME ESTABLISHED ACROSS MN
TODAY...AND BY TONIGHT...CONFIDENCE IS INCREASING IN A COMPLEX OF
TSRA DEVELOPING...ESPECIALLY AFTER 6Z EAST OF AXN/RWF. STILL
DISSAGREEMENT ON PLACEMENT OF THIS ACTIVITY...WITH NAM MAINLY
NORTH OF I-94...ECMWF SOUTH OF I-94 AND THE GFS ALONG I-94. STUCK
WITH THE MIDDLE ROAD FOR THESE TAFS. ONCE FOG BURNS OFF IN EAU
THIS MORNING...EXPECT ANOTHER PERIOD OF VFR CONDITIONS OUTSIDE OF
ANY PRECIP. MAIN CHANGE IN WEATHER COMPARED TO SATURDAY IS THERE
WILL BE MORE MID/UPPER LEVEL CLOUD COVER DURING THE DAY...AND
WINDS WILL BE TURNING OVER TO THE SOUTH.
KMSP...CONDITIONS LOOK GOOD UNTIL TONIGHT...WHEN THUNDERSTORMS ARE
EXPECTED TO DEVELOP ON THE NOSE OF A LLJ. COULD SEE ACIVITIY MOVE
IN PRIOR TO 6Z...BUT LLJ SUPPORT DOES NOT LOOK TO BECOME FAVORABLE
UNTIL AFTER 6Z...WITH THE 8-12Z WINDOW CURRENTLY LOOKING THE MOST
LIKELY ONE FOR SEEING THUNDER. FUTURE SHIFTS SHOULD BE ABLE TO
NARROW DOWN THE PRECIP WINDOW FROM 6 TO 2 OR 3 HOURS AS CONFIDENCE
IN TIMING INCREASES.
/OUTLOOK FOR KMSP/
MON...VFR. ISOL TSRA POSSIBLE IN AFTERNOON. WINDS BMNG NW AT LESS
THAN 10 KTS.
TUE...MVFR CONDS POSSIBLE WITH A CHANCE OF SHRA/TSRA. WINDS SW
5-10 KTS...SHIFTING TO NW OVERNIGHT.
WED...VFR. WINDS NNW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
941 AM CDT Sun Aug 4 2013
.UPDATE...
Issued at 940 AM CDT SUN AUG 4 2013
Lowered temperatures across the southwest 1/3 of the CWA based upon
extensive cloud cover and rain-cooled air. Precipitation shield
associated with KS MCS running into a brick wall of drier air that
covers northern and central MO, courtesy of easterly boundary layer
flow advecting in mid/upper 50 dewpoints, so leading edge of
convection can only creep eastward over the western CWA. Satellite
imagery shows cloud tops have markedly warmed over the past few hours
with a corresponding decrease in precipitation rates. However, cloud
tops have cooled considerably over southwest MO and thus convection
to the south of the CWA has blossomed. 12Z NAM is much more bullish
on rain over the western and central CWA for later this morning and
afternoon but given the current satellite and radar trends I have my
doubts this model is able to handle the MCS feature correctly. Prefer
to side with the latest HRRR output which appears to have a better
handle on precipitation.
&&
.SHORT TERM...(Today through Monday Afternoon)
Issued at 323 AM CDT SUN AUG 4 2013
Shortwave energy crossing the Central Plains today will bring an
increasing chance for rain to much of eastern Kansas and the western
half of Missouri today. Early this morning, a widespread area of
showers and thunderstorms continued to slowly cross central Kansas
as a shortwave visible in WV approached western Kansas. Regional VAD wind
profile data indicated that 850mb winds were finally veering this
morning in response to the shortwave. This directional turn suggests
a northward shift in the 850 baroclinic zone towards the area, with
increasing isentropic lift allowing for scattered showers to develop
across southern Nebraska and NE Kansas.
Today: Low level winds will continue to slowly veer this morning as
the shortwave tracks east southeast into central Kansas. Rain
chances will gradually increase through the morning hours as
low-level flow finally turns southwest by mid-late morning.
However, given the track of the shortwave and fairly pronounced
influences of high pressure centered over the Great Lakes, some
questions remain as to how far east rain will track today. Models
suggest highest precip chances will focus themselves during the late
morning through mid-aftn hours.
Tonight: Despite a departing shortwave, an increasing low level jet
should interact with considerable low-mid level moisture in the
region to allow for redevelopment of thunderstorms over west central
Missouri. The prevailing flow should take this activity into the
Ozarks by daybreak Monday.
Monday: The majority of Monday will likely be warm, humid but dry.
Low level thermal ridge axis stretched across the CWA will promote
rather warm temperatures approaching the 90s in some areas. A weak
surface trough and perhaps remnant outflow from overnight convection
will be a focal point for potential thunderstorm development late
Monday afternoon into Monday evening.
.LONG TERM...(Monday Evening through Saturday)
Issued at 323 AM CDT SUN AUG 4 2013
Most models agree on a weak wave tracking across the area Monday
night while a weak low-level jet noses into eastern KS. This could
support another wave of convection Monday evening particularly
across areas south of I-70. Better chances for thunderstorms still
appear in store Tuesday evening and overnight as a cold front moves
through. Better chances for widespread storms will be north of
Highway 36 where the front will arrive sooner and have better
instability to work with. Instability and shear profiles are
supportive of a large convective system with damaging winds coming
out of Nebraska and Iowa, which could survive after dark as far
south as the Missouri River.
Medium range models continue to show a rather extensive surface high
building in from the north Wednesday through Friday. This should act
to keep things mostly dry once lingering storms clear out from north
to south on Wednesday. Boundary should stall over the Ozarks on
Thursday, which could support additional storms across that region
through the end of the week. Better chances for rain through this
time should stay south of the forecast area.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday Morning)
Issued at 626 AM CDT SUN AUG 4 2013
MCS continues to roll across central Kansas this morning, with
scattered showers and thunderstorms beginning to develop on the
eastern edge of precipitation shield. This wave will slide south of the
KC terminals today, but should spread light rain across the KC
terminals in the upcoming few hours. Generally ceilings will remain
VFR, with brief reductions to visibility should heavier showers move
through the area.
As this wave slides into southwestern Missouri this afternoon, it
should also take MVFR ceilings along with it. Can`t rule out
afternoon redevelopment on the backside of this disturbance near the
KS/MO state line, but confidence in coverage and occurrence too low to indicate.
Overnight, a strengthening low level jet will induce scattered
showers once again towards midnight. Feel this area will be focused in
central Missouri, thus will not include in current TAF, but will need
to be monitored.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...Dux
LONG TERM...Hawblitzel
AVIATION...Dux
AREA FORECAST DISCUSSION...UPDATED
NWS GLASGOW MT
951 AM MDT SUN AUG 4 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TODAY THROUGH TUESDAY...
SENT A MINOR FORECAST UPDATE THIS MORNING. ALTHOUGH GENERAL
THUNDERSTORMS ARE EXPECTED FOR OUR ENTIRE CWA ON THE NATIONAL
LEVEL...MULTIPLE SMALLER SCALE AND HIGH RESOLUTION PRODUCTS
INDICATE THAT CENTRAL AND SOUTHERN PORTIONS OF OUR CWA WILL BE
QUIET TODAY. I ADJUSTED THE POPS AND WEATHER GRIDS BY CUTTING THEM
BACK TO SILENT...FOLLOWING THE MAJORITY OF MODEL CONSENSUS I COULD
FIND. MODEL FORCING FOR ASCENT SHOWS NEUTRAL BEING REPLACED BY
SUBSIDENCE LATER ON THIS AFTERNOON AND EVENING. THE HRRR MODEL
DOES SHOW SOME AFTERNOON SHOWERS AND THUNDERSTORMS BUT THEY DO NOT
REACH MUCH FURTHER SOUTH THAN NEAR FORT PECK LAKE AND THE MISSOURI
RIVER EASTWARD. BMICKELSON
PREVIOUS SHORT TERM DISCUSSION...SPLITTING UPPER TROF OVER THE
PACIFIC NORTHWEST WEST WILL BE THE MAIN WEATHER FEATURE FOR THE
NEXT 24 TO 36 HOURS. AT THAT POINT THE UPPER LOW OVER HUDSON BAY
DROPPING INTO CENTRAL CANADA WILL DOMINANT THE NORTHERN PLAINS.
LIGHT WINDS AND MOISTURE LINGERING OVER THE REGION FROM YESTERDAYS
STORMS ALLOWING SOME LOW CLOUDS AND FOG TO FORM THIS MORNING. WITH
ANOTHER SHORTWAVE MOVING INTO THE STATE TODAY...TO ENCOUNTER THE
MOISTURE UNSTABLE AIR MASS OVER EASTERN MONTANA...EXPECT A FEW
THUNDERSTORMS IN THE AFTERNOON.
A SLIGHTLY DRIER RIDGE DEVELOPS TONIGHT BEFORE BEING SUPPRESSED BY
SHORTWAVE SLIDING DOWN THE CANADIAN ROCKIES ON MONDAY. THIS WAVE
HELPS TO PULL THE HUDSON BAY LOW WESTWARD INTO MANITOBA BY
TUESDAY. CANADIAN SHORTWAVE PUSHES COLD FRONT THROUGH NORTHEAST
MONTANA LATE MONDAY WITH SHOWERS AND A FEW THUNDERSTORMS. ENOUGH
INSTABILITY LINGERS WITH THE COOLER AIR FOR ADDITIONAL SHOWERS ON
TUESDAY. EBERT
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
SYNOPTIC SET UP A CLOSED LOW EXISTS OVER THE THE ONTARIO/MANITOBA
BORDER WITH A COLD FRONT EXTENSION OVER THE UPPER MISSISSIPPI
VALLEY THE NORTHERN US PLAINS AND THE CENTRAL US HIGH PLAINS.
COLD AIR BEHIND THE FRONT WILL SMASH THE INTENSITY OF THE LARGE
HEAT DOME OVER THE FOUR CORNERS AND REDUCING IT TO A RIDGE OVER
THE INTER-MOUNTAIN WEST AND BRITISH COLUMBIA. A LARGE TROUGH IS
DEVELOPING OVER THE GULF OF ALASKA WITH A FAR WEAKER TROUGH OFF THE
COAST OF CALIFORNIA AND THE PACIFIC NORTHWEST.
TUESDAY NIGHT THROUGH FRIDAY... NORTHEAST MONTANA LIES IN A ZONAL
TO NORTHWEST FLOW PATTERN WITH WEAK SHORTWAVES COMING ACROSS ON A
REGULAR BASIS. TIMING OF THE WAVES IS DIFFICULT. HOWEVER... THE
TROUGH OVER ONTARIO AND MANITOBA WILL SEND A COLD FRONT DOWN
THROUGH THE AREA WEDNESDAY EVENING. TEMPERATURES ARE ANTICIPATED
TO COOL OFF BY ABOUT 10 DEGREES POST FRONT FOR HIGHS AND LOWS
WITH THE AFFECT LINGERING THROUGH FRIDAY EVENING. CHANCES FOR RAIN WILL
EXIST ALONG AND BEHIND THE FRONT.
SATURDAY ONWARD... THE LARGE TROUGH OVER ONTARIO WILL PUSH EAST
INTO QUEBEC ALLOWING THE LARGE RIDGE TO THE WEST TO GAIN
INCREASING DOMINION OVER THE NORTHEAST MONTANA WEATHER PATTERN.
EXPECTED TEMPERATURES TO CREEP UPWARDS TO NEAR NORMAL AGAIN WITH
CHANCES FOR RAIN DROPPING SLOWLY. GAH
&&
.AVIATION...
AREAS OF MVFR WITH SOME LOCALIZED IFR...THIS SHOULD ALL BECOME VFR
BY 18Z. 12Z SOUNDING AT KGGW SHOWS THE INVERSION THAT IS CREATING
THE LOW CEILINGS AND FOG TO BE AROUND 3200 AGL...WITH A BURN OFF
TEMPERATURE AROUND 72 WHICH SHOULD LINE UP WITH MID DAY. THEN JUST
SOME LIGHT CONVECTIVE ACTIVITY FOR THE AFTERNOON HOURS. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
1035 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE CONTINUES ACROSS OUR REGION TODAY WITH
ADDITIONAL SHOWERS WITH EMBEDDED THUNDERSTORMS POSSIBLE.
TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS MAINLY
IN THE 60S TO NEAR 70. HIGH PRESSURE LOCATED OVER THE CENTRAL GREAT
LAKES WILL SHIFT INTO THE REGION ON MONDAY...WITH CLEARING SKIES AND
COOL TEMPERATURES. A WARMING TREND IS EXPECTED BY THE MIDDLE OF THIS
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT SUNDAY...FORECAST APPEARS ON TRACK AND JUST SOME
MINOR EDITS NECESSARY. SCATTERED SHOWERS BEGINNING TO APPEAR AS
SHORT WAVE TROF SWINGS THROUGH. BEST CHANCE FOR SHOWERS WILL BE
NORTHERN VERMONT...THOUGH MOST AREAS WILL SEE SOME SCATTERED
ACTIVITY. BEST CHANCE FOR A T-STORM WILL BE CENTRAL/SOUTHERN
VERMONT TODAY WHERE SUNSHINE APPEARED THIS MORNING AND BEST
INSTABILITY EXISTS. INCREASED TEMPS SLIGHTLY ACROSS THE SOUTHERN
VERMONT TO ACCOUNT FOR ADDITIONAL SUNSHINE...OTHERWISE MINOR
CHANGES.
ONCE AGAIN FCST FOCUS WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/STORMS TODAY. WATER VAPOR SHOWS DEEP MID/UPPER LVL TROF
ACRS THE NE CONUS...WITH TWO ADDITIONAL S/W`S EXPECTED TO IMPACT
OUR CWA TODAY. FIRST S/W IS LOCATED OVER JUST NORTH OF THE EASTERN
GREAT LAKES...AND WL BE ACRS OUR WESTERN ZNS BTWN 12-15Z
TODAY...MEANWHILE STRONG ENERGY BTWN HUDSON BAY AND NORTHERN GREAT
LAKES WL APPROACH OUR CWA BY 18Z TODAY. THIS PIECE OF ENERGY
DIVING ALONG THE SOUTHERN PERIPHERY OF TROF WL HELP DEVELOP A
CLOSED 5H/7H CIRCULATION OVER SOUTHERN CANADA BY 00Z MONDAY. THIS
CYCLONIC UPSLOPE FLW...ALONG WITH LLVL CAA...AND LEFTOVER 1000 TO
700 MOISTURE WL HELP IN THE DEVELOPMENT OF ADDITIONAL UPSLOPE
SHOWERS THIS EVENING. FOR TODAY...WL CONT TO MENTION LIKELY POPS
WITH GREATEST CHCS ACRS THE NORTHERN/CENTRAL ZNS...WHERE 850 TO
500MB RH IS THE DEEPEST. IN ADDITION...BEST PVA ASSOCIATED WITH 5H
VORT AND NOSE OF 25H JET IS ACRS THIS REGION. LATEST RAP SOUNDINGS
CONT TO SUPPORT SOME SFC HEATING RESULTING IN CAPE VALUES BTWN 800
AND 1200 J/KG...AND LIS AROUND -2C...FROM DEVELOPING COLD POOL
ALOFT. THIS INSTABILITY SHOULD PROMOTE STRONG ENOUGH UPDRAFTS TO
SUPPORT MENTION OF THUNDER...ESPECIALLY MTNS AND NORTHERN CWA. THE
COMBINATION OF LOW WET BULB ZERO HEIGHTS ASSOCIATED WITH COLD
THERMAL PROFILES...SOME SMALL HAIL WL BE POSSIBLE...IN ADDITION TO
LOCALIZED WIND GUSTS TO 30 MPH. THE LACK OF INSTABILITY WL KEEP
STORMS BLW SVR LIMITS THIS AFTN AND LIMITED DEEP MOISTURE WL LIMIT
AREAL COVERAGE. WL MENTION CHCS IN HWO...BUT NOT ZONES ATTM. CWMW
SOUNDING SHOWS 1000 TO 850MB TEMPS BTWN 1 AND 3C COOLER THAN 24HR
AGO...SUPPORTING HIGHS ONLY IN THE 60S MTNS TO NEAR 70F VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 415 AM EDT SUNDAY...LARGE SCALE SYNOPTIC FORCING FROM
POTENT 5H VORT WL TRANSITION TO MESOSCALE UPSLOPE LIFT AS CYCLONIC
NW FLW CONTS ACRS OUR REGION TONIGHT. EXPECT AREAL COVERAGE/INTENSITY OF
PRECIP TO QUICKLY DISSIPATE BY 00Z THIS EVENING...WITH
PRECIP CONFINED ALONG THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/GREEN MTNS. UPSLOPE PROCEDURE SHOWS GOOD 1000 TO 700MB
RH...FAVORABLE SFC TO 700MB FLW OF 20 TO 30 KNOTS...AND ASSOCIATED
ENHANCED UVVS ACRS THE WESTERN SLOPES. WL MENTION LIKELY POPS THRU
03Z ACRS THE MTNS...WITH SCHC/CHC POPS ELSEWHERE...AFT 03Z DEEP
LAYER MOISTURE QUICKLY DECREASES AS SUBSIDENCE DEVELOPS. THIS WL
RESULT IN CLRING SKIES IN MOST LOCATIONS BY MORNING...EXCEPT
NORTHERN VT. LLVL CAA RESULTS IN PROGGED 85H TEMPS BTWN 2-4C BY
12Z MONDAY...WITH GOOD BL MIXING. THIS WL SUPPORT ADVECTION TYPE
COOLING WITH LOWS RANGING FROM THE U30S SLK TO NEAR 50F CPV. IF
WINDS DECOUPLE AT SLK...COULD SEE TEMPS DROP INTO THE MID 30S BY
12Z MONDAY.
MONDAY AND TUESDAY...SFC HIGH PRES BUILDING ACRS OUR CWA WL RESULT
IN DRY CONDITIONS AND BLW NORMAL TEMPS. THERMAL SOUNDINGS SUGGEST
MORE OF A FALL LIKE TEMP PROFILE ON MONDAY. PROGGED 85H TEMPS BTWN
4-6C...WITH MOSTLY SUNNY SKIES SUPPORT HIGHS 60S TO NEAR 70 MOST
LOCATIONS. A CHILLY NIGHT IS EXPECTED ON MONDAY NIGHT/TUES MORNING
WITH LOWS RANGING FROM M30S SLK/LAKE PLACID/NEK TO M/U 40S CPV...AND
MID 50S NEAR THE LAKE. TUESDAY...WEAK LLVL WAA DEVELOPS WITH MAINLY
CLR SKIES AND TEMPS IN THE 70S. INTERESTING TO SEE THE GOOD MIXING
ON MONDAY AFTN...AND HOW THE SFC DWPTS DROP INTO THE M/U 30S...VERY
DRY AIR IS PROGGED TO MIX DOWN....RESULTING IN LOW RH VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...LARGE UPPER TROUGH TAKES SHAPE OVER CENTRAL
CANADA AND THE UPPER MIDWEST TUESDAY NIGHT INTO WEDNESDAY
MORNING. THIS WILL HELP TO BACK THE UPPER FLOW TO THE WEST AND
SOUTHWEST ON WEDNESDAY. THIS WILL ALLOW 850/925 MILLIBAR
TEMPERATURES TO RISE AND LOOKING AT HIGH TEMPERATURES RIGHT AROUND
SEASONAL NORMALS WEDNESDAY. CLOUDS WILL ALSO BE ON THE INCREASE
AND THERE COULD BE SOME AFTERNOON THUNDERSTORMS...BUT IT APPEARS
BEST DYNAMIC SUPPORT/SURFACE COLD FRONT DO NOT MOVE INTO THE AREA
UNTIL WEDNESDAY NIGHT AND THURSDAY. GOING FORECAST HAS THIS IDEA
COVERED WELL AND HAVE CONTINUED THIS THINKING IN THE GRIDS.
FORCING/COLD FRONT MOVE EAST OF THE AREA THURSDAY NIGHT FOR A
DRYING TREND AND PRONOUNCED WESTERLY FLOW ALOFT DEVELOPS OVER THE
AREA ON FRIDAY. LOW LEVEL THERMAL PROFILE SHOWS WARMEST READINGS
OF THE WEEK MOVE INTO THE AREA ON FRIDAY. THIS WILL PRODUCE HIGH
TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS. AN UPPER LEVEL
DISTURBANCE WILL APPROACH THE AREA LATER ON SATURDAY... BUT BEST
FORCING LOOKS TO STAY UP IN CANADA...THUS GOING FORECAST OF A
SLIGHT CHANCE OF SHOWERS LOOKS GOOD.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...TRENDS THROUGH 15Z WILL TAKE CEILINGS FROM
THE VFR CATEGORY DOWN INTO THE MVFR CATEGORY AND CEILINGS WILL
REMAIN IN THE MVFR CATEGORY THROUGH THE REMAINDER OF THE PERIOD.
THE ONLY EXCEPTION TO THIS WILL BE KSLK WHICH WILL START IN THE
IFR CATEGORY AND INCREASE UP INTO THE MVFR CATEGORY. SCATTERED
SHOWERS WILL MOVE DOWN FROM SOUTHERN QUEBEC PROVINCE AND ACROSS
THE AREA BETWEEN 15Z AND 02Z. HOWEVER...VISIBILITIES WILL REMAIN
IN THE VFR CATEGORY. WINDS WILL INCREASE INTO THE 10 TO 15 KNOT
RANGE BY 14Z...BUT WILL TAPER OFF UNDER 10 KNOTS AFTER 00Z.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 00Z THURSDAY...VFR UNDER SURFACE HIGH PRESSURE.
00Z THURSDAY THROUGH 00Z FRIDAY...VFR TRENDING TO MVFR/IFR IN
SHOWERS AND STORMS AS A WARM FRONT LIFTS ACROSS THE NORTHEAST.
&&
.EQUIPMENT...
AS OF 1225 PM EDT SATURDAY...NOAA WEATHER RADIO WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR HAS RETURNED TO SERVICE. HOWEVER...TECHNICIANS HAVE
DETERMINED THAT ADDITIONAL WORK IS NEEDED AT THE SITE. PARTS ARE
ON ORDER...WITH ADDITIONAL DOWNTIME EXPECTED AS EARLY AS NEXT
WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER/NF
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
934 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER NORTHWEST FLOW WILL DEVELOP TODAY...ALONG WITH SCATTERED
LIGHT SHOWERS THROUGH EARLY AFTERNOON...MAINLY OVER CENTRAL NEW
YORK. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN TONIGHT THROUGH
MONDAY...WITH MAINLY CLEAR SKIES. VERY COOL TEMPERATURES
OVERNIGHT...WILL MODERATE BACK INTO THE 70S MONDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM...LAKE EFFECT CLDS ARE NOW WELL ENTRENCHED IN THE AREA THIS
MRNG. NAM TRIES TO DRY US OUT LTR IN THE AFTN WHILE THE HRRR KEEPS
THE CLDS AND SPRINKLES THRU THE DAY. LEAN TWRDS THE HRRR SOLN AS
IT/S NEVER SMART TO UNDERESTIMATE THE ABILITY OF UPSTATE NY TO
GENERATE CLDS IN A COOL NW FLOW. HAVE LWRD AFTN HI/S A BIT AND
INCRSD CLDS AND PCPN CHANCE.
415 AM UPDATE... WATER VAPOR IMAGERY SHOWS AN UPR LVL TROUGH IN
THE PROCESS OF DEEPENING ACRS THE UPR LKS RGN...SERN CANADA...AND
THE NERN CONUS THIS MRNG. AS THIS EVOLUTION CONTS TDY...A NWLY
FLOW REGIME AND LOW-LVL CAA WILL PREVAIL. THE LATEST MESO`S
ALREADY SHOW 850 MB TEMPS DOWN TO ABT 7C OVER LK ONT...WITH
READINGS PROGGED TO DROP TO 5-6C BY ARND 18Z. GIVEN LK ONT WATER
TEMPS OF 22-24C...ALG WITH THE PRESENCE OF LOW-LVL MOISTURE
TRAPPED UNDER A SUBSIDENCE INVERSION ALOFT...SCTD LK EFF -SHRA
WILL PREVAIL THROUGH MIDDAY-EARLY AFTN. A 290-300 VECTOR FAVORS A
CORRIDOR THROUGH ONONDAGA/SRN CAYUGA/NRN CORTLAND/ONEIDA/MADISON/CHENANGO/
OTSEGO/NRN DELAWARE CNTYS. THESE SHWRS SHOULD DIMINISH BY
18-21Z...AS THE COLUMN BEGINS TO DRY OUT BY THIS TIME.
FARTHER S AND W...ACRS THE TWIN TIERS...THE WYO/LACK VLYS...AND
THE POCONOS...PTLY TO MOSTLY SUNNY SKIES WILL PREVAIL.
AS ALLUDED TO ABV...MAX TEMPS WILL BE COOLER TDY (HIGHS RANGING
FROM THE UPR 60S-MID 70S).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
430 AM UPDATE... GENERALLY QUIET WX FORESEEN THIS PD...AS RIDGING
BOTH SFC AND ALOFT BUILD IN TNT-MON...GRADUALLY MOVING OFF THE
COAST ON TUE.
THE COMBO OF CLEARING SKIES AND A COOL AMS WILL LEAD TO MIN TEMPS
DOWN TO THE MID 40S IN NORMALLY CHILLIER VLYS LTR TNT/EARLY MON...WITH
PATCHY VLY FOG PSBL ACRS THE TWIN TIERS. AS THE AMS MODIFIES DURG
THE DAY MON...PLENTY OF SUNSHINE SHOULD HELP AFTN TEMPS RECOVER
INTO THE 70S (2-4 DEGS HIGHER THAN ON SUN MOST AREAS).
BY TUE...A RETURN SRLY FLOW DVLPS...LEADING TO WARM AND MOIST
ADVECTION. WE MAY SEE A FEW -SHRA DVLP...BUT MOST OF THESE WILL
LIKELY RESIDE ACRS OUR WRN/SRN ZNS...CLOSER TO PASSING S/WV
ENERGY...AND ALSO AN APPROACHING WARM FRNTL BNDRY. FOR NOW...WE`LL
SIMPLY CALL FOR ISOLD-SCTD SHWRS THESE AREAS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
630 AM EDT UPDATE...
FORECAST IS IN GOOD SHAPE. MINOR CHANGES WERE MADE.
PREVIOUS UPDATE...
RISING HGTS ON TUE WILL RESULT IN SOME INCRSG CLDS BUT
SHWRS SHD BE LIMITED DUE TO STUBBORN LL DRY AIR. YET ANOTHER
DIGGING LOW APCHS FOR WED AND THU AND PUSHES A SFC BNDRY THRU THE
AREA. GOOD GULF CONNECTIONS SHD LEAD TO GOOD CVRG OF SHWRS AND
TRWS LATE WED INTO THU AHD OF THE TROF. DRIER AND COOLER AIR
RETURNS ON FRI BHD THE FNT. ATTM IT LOOKS DRY BHD THE FNT BUT
EVENTUALLY THE LWRG HGTS WITH THE LRG UA LOW WILL RESULT IN MAINLY
AFTN CONV.
TEMPS WILL CONT TO AVG WELL BLO SEASONAL NORMS THRU THE PD. MEX
GUID WAS RUNNING A BIT HIER THRU THE PD THAN HPC BUT SEEMED LIKE
THE COOLER EURO HAD A BETTER HANDLE ON THE UA LOW SO MORE CLOSELY
FLWD HPC GUID.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
630 AM EDT UPDATE...
MVFR LAKE EFFECT CLOUDS HAVE DEVELOPED ACROSS MUCH OF THE REGION
THIS MORNING. CLOUDS ARE EXPECTED TO BECOME MORE DENSE AND
WIDESPREAD AS WEST/NORTHWESTERLY WINDS INCREASE THIS MORNING AND
COLDER AIR MOVES ACROSS THE FINGER LAKES. BY MID AFTERNOON CLOUDS
WILL LIFT TO VFR AND START TO SLOWLY DIMINISH. BY SUNDAY NIGHT THE
MAJORITY OF THE CLOUDS WILL DISSIPATE AND RADIATIONAL COOLING WILL
START TO OCCUR. AS RADIATIONAL COOLING TAKES PLACE FOG WILL
DEVELOP ACROSS CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. AS THE
NIGHT TRANSITIONS INTO MONDAY MORNING THE FOG WILL BECOME
DENSE...THUS PUT BR IN TAFS FOR KRME... KITH... KELM... AND KBGM
WHERE CONFIDENCE IS HIGHEST WHERE DEVELOPMENT WILL TAKE PLACE.
MON THRU WED...MAINLY VFR.
THU...MVFR IN SHRA AND TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...DGM/MLJ
LONG TERM...DGM
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
734 AM EDT SUN AUG 4 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE CONTINUES ACROSS OUR REGION TODAY WITH
ADDITIONAL SHOWERS WITH EMBEDDED THUNDERSTORMS POSSIBLE.
TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS MAINLY
IN THE 60S TO NEAR 70. HIGH PRESSURE LOCATED OVER THE CENTRAL GREAT
LAKES WILL SHIFT INTO THE REGION ON MONDAY...WITH CLEARING SKIES AND
COOL TEMPERATURES. A WARMING TREND IS EXPECTED BY THE MIDDLE OF THIS
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 706 AM EDT SUNDAY...MINOR UPDATE FOR CRNT OBS AND LATEST
RADAR/SATL TRENDS. OBS SHOW LIGHT RAIN ALREADY AT
MONTREAL...ASSOCIATED WITH NEXT S/W. EXPECT AREAL COVERAGE OF
PRECIP TO INCREASE ACRS OUR NORTHERN CWA BTWN 14-16Z. TEMPS WL
SLOWLY WARM INTO THE 60S TO NEAR 70F BY THIS AFTN.
ONCE AGAIN FCST FOCUS WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/STORMS TODAY. WATER VAPOR SHOWS DEEP MID/UPPER LVL TROF
ACRS THE NE CONUS...WITH TWO ADDITIONAL S/W`S EXPECTED TO IMPACT
OUR CWA TODAY. FIRST S/W IS LOCATED OVER JUST NORTH OF THE EASTERN
GREAT LAKES...AND WL BE ACRS OUR WESTERN ZNS BTWN 12-15Z
TODAY...MEANWHILE STRONG ENERGY BTWN HUDSON BAY AND NORTHERN GREAT
LAKES WL APPROACH OUR CWA BY 18Z TODAY. THIS PIECE OF ENERGY
DIVING ALONG THE SOUTHERN PERIPHERY OF TROF WL HELP DEVELOP A
CLOSED 5H/7H CIRCULATION OVER SOUTHERN CANADA BY 00Z MONDAY. THIS
CYCLONIC UPSLOPE FLW...ALONG WITH LLVL CAA...AND LEFTOVER 1000 TO
700 MOISTURE WL HELP IN THE DEVELOPMENT OF ADDITIONAL UPSLOPE
SHOWERS THIS EVENING. FOR TODAY...WL CONT TO MENTION LIKELY POPS
WITH GREATEST CHCS ACRS THE NORTHERN/CENTRAL ZNS...WHERE 850 TO
500MB RH IS THE DEEPEST. IN ADDITION...BEST PVA ASSOCIATED WITH 5H
VORT AND NOSE OF 25H JET IS ACRS THIS REGION. LATEST RAP SOUNDINGS
CONT TO SUPPORT SOME SFC HEATING RESULTING IN CAPE VALUES BTWN 800
AND 1200 J/KG...AND LIS AROUND -2C...FROM DEVELOPING COLD POOL
ALOFT. THIS INSTABILITY SHOULD PROMOTE STRONG ENOUGH UPDRAFTS TO
SUPPORT MENTION OF THUNDER...ESPECIALLY MTNS AND NORTHERN CWA. THE
COMBINATION OF LOW WET BULB ZERO HEIGHTS ASSOCIATED WITH COLD
THERMAL PROFILES...SOME SMALL HAIL WL BE POSSIBLE...IN ADDITION TO
LOCALIZED WIND GUSTS TO 30 MPH. THE LACK OF INSTABILITY WL KEEP
STORMS BLW SVR LIMITS THIS AFTN AND LIMITED DEEP MOISTURE WL LIMIT
AREAL COVERAGE. WL MENTION CHCS IN HWO...BUT NOT ZONES ATTM. CWMW
SOUNDING SHOWS 1000 TO 850MB TEMPS BTWN 1 AND 3C COOLER THAN 24HR
AGO...SUPPORTING HIGHS ONLY IN THE 60S MTNS TO NEAR 70F VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 415 AM EDT SUNDAY...LARGE SCALE SYNOPTIC FORCING FROM
POTENT 5H VORT WL TRANSITION TO MESOSCALE UPSLOPE LIFT AS CYCLONIC
NW FLW CONTS ACRS OUR REGION TONIGHT. EXPECT AREAL COVERAGE/INTENSITY OF
PRECIP TO QUICKLY DISSIPATE BY 00Z THIS EVENING...WITH
PRECIP CONFINED ALONG THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/GREEN MTNS. UPSLOPE PROCEDURE SHOWS GOOD 1000 TO 700MB
RH...FAVORABLE SFC TO 700MB FLW OF 20 TO 30 KNOTS...AND ASSOCIATED
ENHANCED UVVS ACRS THE WESTERN SLOPES. WL MENTION LIKELY POPS THRU
03Z ACRS THE MTNS...WITH SCHC/CHC POPS ELSEWHERE...AFT 03Z DEEP
LAYER MOISTURE QUICKLY DECREASES AS SUBSIDENCE DEVELOPS. THIS WL
RESULT IN CLRING SKIES IN MOST LOCATIONS BY MORNING...EXCEPT
NORTHERN VT. LLVL CAA RESULTS IN PROGGED 85H TEMPS BTWN 2-4C BY
12Z MONDAY...WITH GOOD BL MIXING. THIS WL SUPPORT ADVECTION TYPE
COOLING WITH LOWS RANGING FROM THE U30S SLK TO NEAR 50F CPV. IF
WINDS DECOUPLE AT SLK...COULD SEE TEMPS DROP INTO THE MID 30S BY
12Z MONDAY.
MONDAY AND TUESDAY...SFC HIGH PRES BUILDING ACRS OUR CWA WL RESULT
IN DRY CONDITIONS AND BLW NORMAL TEMPS. THERMAL SOUNDINGS SUGGEST
MORE OF A FALL LIKE TEMP PROFILE ON MONDAY. PROGGED 85H TEMPS BTWN
4-6C...WITH MOSTLY SUNNY SKIES SUPPORT HIGHS 60S TO NEAR 70 MOST
LOCATIONS. A CHILLY NIGHT IS EXPECTED ON MONDAY NIGHT/TUES MORNING
WITH LOWS RANGING FROM M30S SLK/LAKE PLACID/NEK TO M/U 40S CPV...AND
MID 50S NEAR THE LAKE. TUESDAY...WEAK LLVL WAA DEVELOPS WITH MAINLY
CLR SKIES AND TEMPS IN THE 70S. INTERESTING TO SEE THE GOOD MIXING
ON MONDAY AFTN...AND HOW THE SFC DWPTS DROP INTO THE M/U 30S...VERY
DRY AIR IS PROGGED TO MIX DOWN....RESULTING IN LOW RH VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...LARGE UPPER TROUGH TAKES SHAPE OVER CENTRAL
CANADA AND THE UPPER MIDWEST TUESDAY NIGHT INTO WEDNESDAY
MORNING. THIS WILL HELP TO BACK THE UPPER FLOW TO THE WEST AND
SOUTHWEST ON WEDNESDAY. THIS WILL ALLOW 850/925 MILLIBAR
TEMPERATURES TO RISE AND LOOKING AT HIGH TEMPERATURES RIGHT AROUND
SEASONAL NORMALS WEDNESDAY. CLOUDS WILL ALSO BE ON THE INCREASE
AND THERE COULD BE SOME AFTERNOON THUNDERSTORMS...BUT IT APPEARS
BEST DYNAMIC SUPPORT/SURFACE COLD FRONT DO NOT MOVE INTO THE AREA
UNTIL WEDNESDAY NIGHT AND THURSDAY. GOING FORECAST HAS THIS IDEA
COVERED WELL AND HAVE CONTINUED THIS THINKING IN THE GRIDS.
FORCING/COLD FRONT MOVE EAST OF THE AREA THURSDAY NIGHT FOR A
DRYING TREND AND PRONOUNCED WESTERLY FLOW ALOFT DEVELOPS OVER THE
AREA ON FRIDAY. LOW LEVEL THERMAL PROFILE SHOWS WARMEST READINGS
OF THE WEEK MOVE INTO THE AREA ON FRIDAY. THIS WILL PRODUCE HIGH
TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS. AN UPPER LEVEL
DISTURBANCE WILL APPROACH THE AREA LATER ON SATURDAY... BUT BEST
FORCING LOOKS TO STAY UP IN CANADA...THUS GOING FORECAST OF A
SLIGHT CHANCE OF SHOWERS LOOKS GOOD.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
THROUGH 12Z MONDAY...TRENDS THROUGH 15Z WILL TAKE CEILINGS FROM
THE VFR CATEGORY DOWN INTO THE MVFR CATEGORY AND CEILINGS WILL
REMAIN IN THE MVFR CATEGORY THROUGH THE REMAINDER OF THE PERIOD.
THE ONLY EXCEPTION TO THIS WILL BE KSLK WHICH WILL START IN THE
IFR CATEGORY AND INCREASE UP INTO THE MVFR CATEGORY. SCATTERED
SHOWERS WILL MOVE DOWN FROM SOUTHERN QUEBEC PROVINCE AND ACROSS
THE AREA BETWEEN 15Z AND 02Z. HOWEVER...VISIBILITIES WILL REMAIN
IN THE VFR CATEGORY. WINDS WILL INCREASE INTO THE 10 TO 15 KNOT
RANGE BY 14Z...BUT WILL TAPER OFF UNDER 10 KNOTS AFTER 00Z.
OUTLOOK 12Z MONDAY THROUGH THURSDAY...
12Z MONDAY THROUGH 00Z THURSDAY...VFR UNDER SURFACE HIGH PRESSURE.
00Z THURSDAY THROUGH 00Z FRIDAY...VFR TRENDING TO MVFR/IFR IN
SHOWERS AND STORMS AS A WARM FRONT LIFTS ACROSS THE NORTHEAST.
&&
.EQUIPMENT...
AS OF 1225 PM EDT SATURDAY...NOAA WEATHER RADIO WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR HAS RETURNED TO SERVICE. HOWEVER...TECHNICIANS HAVE
DETERMINED THAT ADDITIONAL WORK IS NEEDED AT THE SITE. PARTS ARE
ON ORDER...WITH ADDITIONAL DOWNTIME EXPECTED AS EARLY AS NEXT
WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...EVENSON/LAHIFF
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
940 AM EDT SUN AUG 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY FROM THE NORTHWEST.
THE HIGH WILL MOVE TO THE EAST COAST ON TUESDAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A COLD FRONT EXPECTED ACROSS
THE AREA ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
UPDATED TO ADD ISOLATED SHOWERS TO EXTREME NORTHEAST OHIO AND
NORTHWEST PA THROUGH EARLY AFTERNOON. NOTHING ON THE RADAR BUT
BASED ON THE SATELLITE AND ENOUGH MOISTURE AND A LAKE AND 850 MB
TEMPERATURE DIFFERENCE OF OVER 13C THE THREAT IS REAL. ELSEWHERE
SOME CUMULUS WILL DEVELOP BY EARLY AFTERNOON. NO SIGNIFICANT
ADJUSTMENTS TO THE HIGHS.
ORIGINAL...WEAK TROUGH AND WIND SHIFT...FORECAST ON THE HRRR AND
VISIBLE ON RADAR MANAGED TO EXPLOIT THE INSTABILITY OVER THE WARM
LAKE TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS SHORTLY AFTER
MIDNIGHT. EXPECT THE SHOWERS TO DISSIPATE AS THEY DROP SOUTH
ACROSS THE AREA THROUGH THE NIGHT. WILL HAVE A SLIGHT CHANCE POP
FOR THE NORTHEAST FOR THE FIRST HALF OF THE DAY HOWEVER WITH SO
MUCH DRY AIR IN THE MID LEVELS MOVING IN NOT EXPECTING MUCH. LOW
LEVEL MOISTURE STILL IN PLACE HOWEVER SO AM THINKING WE WILL HAVE
A GOOD CU FIELD TO DEVELOP...POSSIBLY GOING BROKEN FOR A FEW HOURS
BEFORE MIXING OUT BACK TO SCATTERED. OUTSIDE CHANCE POPS WILL NEED
TO BE RAISED AS 850MB TEMPS DROP TO +7C AND WITH THE LAKE AT +20C
IT COULD BE PROBLEMATIC IF AIRMASS HAS A BIT MORE MID LEVEL
MOISTURE THAN ANTICIPATED. AFTERNOON TEMPS INDICATIVE OF MID TO
LATE SEPTEMBER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND EARLY MONDAY.
EXPECTING MOSTLY CLEAR SKIES WITH WELL BELOW NORMAL TEMPS. MONDAY
AFTERNOON THE HIGH MOVES EAST AND THE NAM AND GFS SHOW SUFFICIENT
MOISTURE FOR AT LEAST THE THREAT OF A SHOWER IN THE WEST DURING
THE AFTERNOON. WILL HAVE LOW CHANCE POPS FOR THE WESTERN TIER OF
COUNTIES WITH A SLIGHT CHANCE EAST TO ROUGHLY A CLEVELAND TO
MANSFIELD LINE. MONDAY NIGHT WENT A BIT ABOVE POP GUIDANCE AND
BROUGHT CHANCE POPS EAST ACROSS THE REMAINDER OF THE AREA GIVEN
DEEP MOISTURE...OVERRUNNING FLOW AND JET ENERGY MOVING THROUGH THE
AREA. TUESDAY THROUGH WEDNESDAY LOW PRESSURE TO THE WEST WILL
SLOWLY MOVE EAST INCREASING MOISTURE AND INSTABILITY ACROSS THE
REGION. WILL BRING IN INCREASING CHANCE POPS FOR SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. TEMPS APPROACHING
NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
STILL UNCLEAR AT THIS POINT WHERE EXACTLY THE FRONT WILL STALL OUT
ON THURSDAY. A WEDGE OF DRY AIR ALOFT IS PULLED OVER THE AREA BUT
ENOUGH LOW LEVEL MOISTURE MAY REMAIN FOR SCATTERED
SHOWERS/THUNDERSTORMS TO DEVELOP FROM CENTRAL TO NORTHEAST OHIO IN
THE VICINITY OF THE BOUNDARY. CHANCES WILL BE LOWER BY FRIDAY
ALTHOUGH CAN NOT ENTIRELY RULE OUT SOMETHING POPPING UP AS MODELS
CONTINUE TO STRUGGLE WITH RESOLVING SHORTWAVE ENERGY MOVING AROUND
THE SOUTHERN PERIPHERY OF THE TROUGH. THE UPPER LOW WILL TRAVERSE
THE UPPER GREAT LAKES FRIDAY NIGHT INTO SATURDAY AND FINALLY PUSH A
STRONGER COLD FRONT SOUTH ACROSS THE AREA. TEMPERATURES WILL DROP
FROM NEAR 80 ON THURSDAY TO THE LOWER 70S ON SUNDAY.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL EXPAND EAST ACROSS THE
CENTRAL GREAT LAKES INTO MONDAY. SATELLITE IMAGERY SHOWS LAKE EFFECT
CLOUDS OFF OF EASTERN LAKE ERIE WITH BKN VFR STRATOCU TO START THE
PERIOD AT CLE/ERI/YNG. THESE CLOUDS WILL SCATTER OUT THROUGH EARLY
AFTERNOON AS WE MIX INTO DRIER AIR ALOFT. WINDS WILL REMAIN OUT OF
THE NORTH THROUGH THE AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE
AFTER 00Z.
.OUTLOOK...NON-VFR POSSIBLE IN SHOWERS/STORMS MONDAY NIGHT AND
AGAIN WEDNESDAY INTO THURSDAY.
&&
.MARINE...
WAVES WILL BUILD THIS MORNING AS NORTHERLY WINDS OF 10 TO 20 KNOTS
CONTINUE ON THE LAKE BEHIND A COLD FRONT. WAVES WILL REACH 2 TO 4
FEET EAST OF AVON AND WILL HAVE TO MONITOR CONDITIONS FOR THE NEED
FOR A SMALL CRAFT ADVISORY. THIS WILL ALSO PRESENT A MODERATE RISK
FOR RIP CURRENTS FOR AREAS EAST OF THE ISLANDS. HIGH PRESSURE OVER
THE UPPER MIDWEST WILL BUILD EAST ACROSS THE LAKE OVERNIGHT THROUGH
MONDAY BRINGING LIGHT WIND AND GOOD MARINE CONDITIONS. SOUTHERLY
WIND WILL INCREASE FROM TUESDAY INTO WEDNESDAY AHEAD OF THE
NEXT LOW PRESSURE SYSTEM.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...KIELTYKA/TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
744 AM EDT SUN AUG 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY FROM THE NORTHWEST.
THE HIGH WILL MOVE TO THE EAST COAST ON TUESDAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A COLD FRONT EXPECTED ACROSS
THE AREA ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...WILL ADD MENTION OF CLOUDS EARLY NORTHEAST. OTHERWISE NO
CHANGES.
ORIGINAL...WEAK TROUGH AND WIND SHIFT...FORECAST ON THE HRRR AND
VISIBLE ON RADAR MANAGED TO EXPLOIT THE INSTABILITY OVER THE WARM
LAKE TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS SHORTLY AFTER
MIDNIGHT. EXPECT THE SHOWERS TO DISSIPATE AS THEY DROP SOUTH
ACROSS THE AREA THROUGH THE NIGHT. WILL HAVE A SLIGHT CHANCE POP
FOR THE NORTHEAST FOR THE FIRST HALF OF THE DAY HOWEVER WITH SO
MUCH DRY AIR IN THE MID LEVELS MOVING IN NOT EXPECTING MUCH. LOW
LEVEL MOISTURE STILL IN PLACE HOWEVER SO AM THINKING WE WILL HAVE
A GOOD CU FIELD TO DEVELOP...POSSIBLY GOING BROKEN FOR A FEW HOURS
BEFORE MIXING OUT BACK TO SCATTERED. OUTSIDE CHANCE POPS WILL NEED
TO BE RAISED AS 850MB TEMPS DROP TO +7C AND WITH THE LAKE AT +20C
IT COULD BE PROBLEMATIC IF AIRMASS HAS A BIT MORE MID LEVEL
MOISTURE THAN ANTICIPATED. AFTERNOON TEMPS INDICATIVE OF MID TO
LATE SEPTEMBER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND EARLY MONDAY.
EXPECTING MOSTLY CLEAR SKIES WITH WELL BELOW NORMAL TEMPS. MONDAY
AFTERNOON THE HIGH MOVES EAST AND THE NAM AND GFS SHOW SUFFICIENT
MOISTURE FOR AT LEAST THE THREAT OF A SHOWER IN THE WEST DURING
THE AFTERNOON. WILL HAVE LOW CHANCE POPS FOR THE WESTERN TIER OF
COUNTIES WITH A SLIGHT CHANCE EAST TO ROUGHLY A CLEVELAND TO
MANSFIELD LINE. MONDAY NIGHT WENT A BIT ABOVE POP GUIDANCE AND
BROUGHT CHANCE POPS EAST ACROSS THE REMAINDER OF THE AREA GIVEN
DEEP MOISTURE...OVERRUNNING FLOW AND JET ENERGY MOVING THROUGH THE
AREA. TUESDAY THROUGH WEDNESDAY LOW PRESSURE TO THE WEST WILL
SLOWLY MOVE EAST INCREASING MOISTURE AND INSTABILITY ACROSS THE
REGION. WILL BRING IN INCREASING CHANCE POPS FOR SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. TEMPS APPROACHING
NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
STILL UNCLEAR AT THIS POINT WHERE EXACTLY THE FRONT WILL STALL OUT
ON THURSDAY. A WEDGE OF DRY AIR ALOFT IS PULLED OVER THE AREA BUT
ENOUGH LOW LEVEL MOISTURE MAY REMAIN FOR SCATTERED
SHOWERS/THUNDERSTORMS TO DEVELOP FROM CENTRAL TO NORTHEAST OHIO IN
THE VICINITY OF THE BOUNDARY. CHANCES WILL BE LOWER BY FRIDAY
ALTHOUGH CAN NOT ENTIRELY RULE OUT SOMETHING POPPING UP AS MODELS
CONTINUE TO STRUGGLE WITH RESOLVING SHORTWAVE ENERGY MOVING AROUND
THE SOUTHERN PERIPHERY OF THE TROUGH. THE UPPER LOW WILL TRAVERSE
THE UPPER GREAT LAKES FRIDAY NIGHT INTO SATURDAY AND FINALLY PUSH A
STRONGER COLD FRONT SOUTH ACROSS THE AREA. TEMPERATURES WILL DROP
FROM NEAR 80 ON THURSDAY TO THE LOWER 70S ON SUNDAY.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
HIGH PRESSURE OVER THE UPPER MIDWEST WILL EXPAND EAST ACROSS THE
CENTRAL GREAT LAKES INTO MONDAY. SATELLITE IMAGERY SHOWS LAKE EFFECT
CLOUDS OFF OF EASTERN LAKE ERIE WITH BKN VFR STRATOCU TO START THE
PERIOD AT CLE/ERI/YNG. THESE CLOUDS WILL SCATTER OUT THROUGH EARLY
AFTERNOON AS WE MIX INTO DRIER AIR ALOFT. WINDS WILL REMAIN OUT OF
THE NORTH THROUGH THE AFTERNOON BEFORE BECOMING LIGHT AND VARIABLE
AFTER 00Z.
.OUTLOOK...NON-VFR POSSIBLE IN SHOWERS/STORMS MONDAY NIGHT AND
AGAIN WEDNESDAY INTO THURSDAY.
&&
.MARINE...
WAVES WILL BUILD THIS MORNING AS NORTHERLY WINDS OF 10 TO 20 KNOTS
CONTINUE ON THE LAKE BEHIND A COLD FRONT. WAVES WILL REACH 2 TO 4
FEET EAST OF AVON AND WILL HAVE TO MONITOR CONDITIONS FOR THE NEED
FOR A SMALL CRAFT ADVISORY. THIS WILL ALSO PRESENT A MODERATE RISK
FOR RIP CURRENTS FOR AREAS EAST OF THE ISLANDS. HIGH PRESSURE OVER
THE UPPER MIDWEST WILL BUILD EAST ACROSS THE LAKE OVERNIGHT THROUGH
MONDAY BRINGING LIGHT WIND AND GOOD MARINE CONDITIONS. SOUTHERLY
WIND WILL INCREASE FROM TUESDAY INTO WEDNESDAY AHEAD OF THE
NEXT LOW PRESSURE SYSTEM.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
619 AM EDT SUN AUG 4 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD ACROSS THE AREA TODAY FROM THE NORTHWEST.
THE HIGH WILL MOVE TO THE EAST COAST ON TUESDAY. THIS WILL ALLOW
LOW PRESSURE TO MOVE INTO THE GREAT LAKES AND OHIO VALLEY REGION
WEDNESDAY AND WEDNESDAY NIGHT WITH A COLD FRONT EXPECTED ACROSS
THE AREA ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...WILL ADD MENTION OF CLOUDS EARLY NORTHEAST. OTHERWISE NO
CHANGES.
ORIGINAL...WEAK TROUGH AND WIND SHIFT...FORECAST ON THE HRRR AND
VISIBLE ON RADAR MANAGED TO EXPLOIT THE INSTABILITY OVER THE WARM
LAKE TO PRODUCE A FEW SHOWERS AND THUNDERSTORMS SHORTLY AFTER
MIDNIGHT. EXPECT THE SHOWERS TO DISSIPATE AS THEY DROP SOUTH
ACROSS THE AREA THROUGH THE NIGHT. WILL HAVE A SLIGHT CHANCE POP
FOR THE NORTHEAST FOR THE FIRST HALF OF THE DAY HOWEVER WITH SO
MUCH DRY AIR IN THE MID LEVELS MOVING IN NOT EXPECTING MUCH. LOW
LEVEL MOISTURE STILL IN PLACE HOWEVER SO AM THINKING WE WILL HAVE
A GOOD CU FIELD TO DEVELOP...POSSIBLY GOING BROKEN FOR A FEW HOURS
BEFORE MIXING OUT BACK TO SCATTERED. OUTSIDE CHANCE POPS WILL NEED
TO BE RAISED AS 850MB TEMPS DROP TO +7C AND WITH THE LAKE AT +20C
IT COULD BE PROBLEMATIC IF AIRMASS HAS A BIT MORE MID LEVEL
MOISTURE THAN ANTICIPATED. AFTERNOON TEMPS INDICATIVE OF MID TO
LATE SEPTEMBER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
HIGH PRESSURE WILL BE ACROSS THE AREA TONIGHT AND EARLY MONDAY.
EXPECTING MOSTLY CLEAR SKIES WITH WELL BELOW NORMAL TEMPS. MONDAY
AFTERNOON THE HIGH MOVES EAST AND THE NAM AND GFS SHOW SUFFICIENT
MOISTURE FOR AT LEAST THE THREAT OF A SHOWER IN THE WEST DURING
THE AFTERNOON. WILL HAVE LOW CHANCE POPS FOR THE WESTERN TIER OF
COUNTIES WITH A SLIGHT CHANCE EAST TO ROUGHLY A CLEVELAND TO
MANSFIELD LINE. MONDAY NIGHT WENT A BIT ABOVE POP GUIDANCE AND
BROUGHT CHANCE POPS EAST ACROSS THE REMAINDER OF THE AREA GIVEN
DEEP MOISTURE...OVERRUNNING FLOW AND JET ENERGY MOVING THROUGH THE
AREA. TUESDAY THROUGH WEDNESDAY LOW PRESSURE TO THE WEST WILL
SLOWLY MOVE EAST INCREASING MOISTURE AND INSTABILITY ACROSS THE
REGION. WILL BRING IN INCREASING CHANCE POPS FOR SCATTERED
SHOWERS AND THUNDERSTORMS THROUGH THE PERIOD. TEMPS APPROACHING
NORMAL.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
STILL UNCLEAR AT THIS POINT WHERE EXACTLY THE FRONT WILL STALL OUT
ON THURSDAY. A WEDGE OF DRY AIR ALOFT IS PULLED OVER THE AREA BUT
ENOUGH LOW LEVEL MOISTURE MAY REMAIN FOR SCATTERED
SHOWERS/THUNDERSTORMS TO DEVELOP FROM CENTRAL TO NORTHEAST OHIO IN
THE VICINITY OF THE BOUNDARY. CHANCES WILL BE LOWER BY FRIDAY
ALTHOUGH CAN NOT ENTIRELY RULE OUT SOMETHING POPPING UP AS MODELS
CONTINUE TO STRUGGLE WITH RESOLVING SHORTWAVE ENERGY MOVING AROUND
THE SOUTHERN PERIPHERY OF THE TROUGH. THE UPPER LOW WILL TRAVERSE
THE UPPER GREAT LAKES FRIDAY NIGHT INTO SATURDAY AND FINALLY PUSH A
STRONGER COLD FRONT SOUTH ACROSS THE AREA. TEMPERATURES WILL DROP
FROM NEAR 80 ON THURSDAY TO THE LOWER 70S ON SUNDAY.
&&
.AVIATION /10Z SUNDAY THROUGH THURSDAY/...
A BAND OF SHOWERS AND ISOLATED THUNDERSTORMS DEVELOPED OVER LAKE
ERIE AND WILL MOVE THROUGH CLE BY 07Z. CONDITIONS WILL BRIEFLY DROP
TO MVFR AND POSSIBLY IFR FOR A FEW MINUTES IN MODERATE TO HEAVY
RAIN. ELSEWHERE CONDITIONS ARE EXPECTED TO REMAIN VFR BUT SCT-BKN
CLOUDS ARE EXPECTED AS COLD ADVECTION INCREASES BEHIND THE FRONT.
SATELLITE IMAGERY SHOWS ONE BAND OF CLOUDS OVER LAKE ERIE WITH
ANOTHER BAND OF CLOUDS ACROSS CENTRAL MICHIGAN PUSHING SOUTHEAST.
WINDS WILL REMAIN OUT OF THE NORTH THROUGH THE AFTERNOON BEFORE
BECOMING LIGHT AND VARIABLE AFTER 00Z.
.OUTLOOK...NON-VFR POSSIBLE IN SHOWERS/STORMS MONDAY NIGHT AND
AGAIN WEDNESDAY INTO THURSDAY.
&&
.MARINE...
WAVES WILL BUILD THIS MORNING AS NORTHERLY WINDS OF 10 TO 20 KNOTS
CONTINUE ON THE LAKE BEHIND A COLD FRONT. WAVES WILL REACH 2 TO 4
FEET EAST OF AVON AND WILL HAVE TO MONITOR CONDITIONS FOR THE NEED
FOR A SMALL CRAFT ADVISORY. THIS WILL ALSO PRESENT A MODERATE RISK
FOR RIP CURRENTS FOR AREAS EAST OF THE ISLANDS. HIGH PRESSURE OVER
THE UPPER MIDWEST WILL BUILD EAST ACROSS THE LAKE OVERNIGHT THROUGH
MONDAY BRINGING LIGHT WIND AND GOOD MARINE CONDITIONS. SOUTHERLY
WIND WILL INCREASE FROM TUESDAY INTO WEDNESDAY AHEAD OF THE
NEXT LOW PRESSURE SYSTEM.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...KEC
AVIATION...KEC
MARINE...KEC
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1044 AM CDT SUN AUG 4 2013
.UPDATE...
ISSUED AT 1044 AM CDT SUN AUG 4 2013
FIRST WEAK WAVE NOW PULLING AWAY ACROSS SOUTHERN MINNESOTA...WITH
CONVECTIVE CLUSTER IN NORTHEAST NEBRASKA AND EXTREME SOUTHEAST
SOUTH DAKOTA. ANOTHER WEAK IMPULSE MOVING ACROSS SOUTH CENTRAL NORTH
DAKOTA AND FAR NORTHERN SOUTH DAKOTA INITIATING NEW CONVECTION
ALONG MID LEVEL BOUNDARY BACK TOWARD NORTH OF KPIR TO KD07. NORTHERN
AREA DEFINITELY LOOKS TO BE THE ONLY LARGER SCALE SUPPORT FOR LIFT
GOING INTO THE AFTERNOON...AND EXPECT SOUTHERN AREA TO START A
MORE NOTABLE WEAKENING TREND IN COVERAGE IN NEXT COUPLE OF HOURS
AS IT PROGRESSES TOWARD SIOUX CITY AND POINT SOUTH/EAST...AS
THERMODYNAMIC SUPPORT FOR DEVELOPMENT CERTAINLY DIMINISHES
EASTWARD...AND DEGREE OF ANY INSTABILITY REALLY ONLY SUPPORTS A
THUNDER THREAT THROUGH MIDDAY IN THE FAR WEST/SOUTH. LIKEWISE...
SHOULD SEE GRADUAL DEMISE OF CLUSTER OF SHOWERS THAT PASSED NEAR
KHON AS IT APPROACHES KFSD TOWARD NOON.
DESPITE CERTAINTY IN THE SHORT TERM BEING FAIRLY LOW...AND MODEL
PERFORMANCE IN WEAKLY FORCED PATTERN DISMAL...HAVE SOME CONFIDENCE
THAT MUCH OF THE AREA THIS AFTERNOON INTO EARLY EVENING SHOULD BE
FREE OF CONVECTION. WILL MAINTAIN AN ISOLATED TO SCATTERED MENTION
IN THE FAR NORTHERN TIER ALONG GLANCING INFLUENCE OF NORTHERN WAVE...
CARRYING WITH IT A GRADUAL SPREAD OF THUNDER MENTION EASTWARD.
TEMPERATURES LOOKED GENERALLY OK FOR THE DAYTIME MAX...BUT MADE AN
ATTEMPT TO ACCOUNT FOR EXPECTED PRECIP AREAS AND COOLER OUTFLOW
FOR THE SHORTER TERM TO DIURNAL TRENDS...AND DID TRIM A FEW AREAS
DOWN A COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN AUG 4 2013
MODELS STRUGGLING WITH ONGOING ACTIVITY ACROSS CENTRAL SOUTH DAKOTA
WHICH HAS DEVELOPED WITH AN INCREASING LOW LEVEL JET AND MID LEVEL
WAVE. DRY AIR TO THE EAST AND MINIMAL INSTABILITY IS EXPECTED TO
CAUSE A DOWNWARD TREND IN THIS CONVECTION AS IT ENTERS OUR CWA. OF
ALL THE GUIDANCE...SEEMS LIKE HRRR IS CLOSEST TO REALITY...WITH THE
0Z ECMWF ALSO NOT TOO BAD. BOTH OF THESE MODELS SUGGEST ACTIVITY
DOES INDEED WEAKEN AND DISSIPATE AS IT PUSHES EAST. HAVE HIGH CHANCE
TO LIKELY POPS THIS MORNING WEST OF THE JAMES RIVER...FROM ABOUT 10Z
TO 15Z. NOTHING SEVERE BUT WOULD EXPECT AT LEAST SOME LIGHTNING
ACTIVITY WITH THE STORMS. SHOWERS COULD MAKE IT AS FAR EAST AS
INTERSTATE 29 BY 13Z...BUT NOT REAL CONFIDENT IT WILL HOLD TOGETHER
EVEN THAT FAR...SO WILL ONLY GO SLIGHT CHANCE POPS. PLUS GIVEN THE
EXPECTED WEAKENING STATE...AND LACK OF INSTABILITY...PROBABLY WILL
NOT BE ANY LIGHTNING WITH ANYTHING THAT DOES MANAGE TO GET EAST OF
THE JAMES RIVER. TEND TO THINK WE SEE A LULL IN THE ACTIVITY DURING
THE AFTERNOON HOURS. BUT GIVEN WEAK FORCING...MID LEVEL MOISTURE
PRESENT...ONGOING ACTIVITY CONTINUING TO DEVELOP OVER NORTHWEST
SOUTH DAKOTA...AND THE GENERALLY LOW PREDICTABILITY OF THE
PATTERN...WILL KEEP A LOW CHANCE POPS IN THE WEST THROUGH THE
DAY...WITH SLIGHT CHANCES TO INTERSTATE 29. DAY SHIFT MAY END UP
BEING ABLE TO REMOVE THESE IF IT BECOMES MORE APPARENT DURING THE
MORNING THAT WE SEE A LULL IN THE ACTION. HIGHS TODAY ARE TRICKY AND
DEPENDENT ON REMNANT CLOUD COVER. THINK IT PROBABLY STAYS MOSTLY
CLOUDY FOR MUCH OF THE DAY. DID BUMP HIGHS UP SOME WITH SOME OF THE
NEWER GUIDANCE COMING IN A BIT WARMER...BUT GIVEN CLOUD COVER
CONCERNS DID NOT WANT TO GO TOO WARM...AND WENT WITH MAINLY MID AND
UPPER 70S. IF WE SOMEHOW ARE ABLE TO GET MORE SUN TODAY...HIGHS
WOULD END UP SEVERAL DEGREES WARMER. SO ANOTHER THING THE DAY SHIFT
WILL HAVE TO MONITOR.
UNFORTUNATELY...FORECAST CONFIDENCE DOES NOT INCREASE TONIGHT. THE
CORE OF THE UPPER LEVEL SUPPORT WILL DIVE SOUTHEAST ACROSS
MINNESOTA. SEEMS LIKE A GOOD BET THAT WE SEE ANOTHER ROUND OF
NOCTURNAL CONVECTION ACROSS THE NORTHERN PLAINS. BEST FORCING IS TO
THE NORTHEAST...WITH BEST INSTABILITY AS YOU GO SOUTHWEST. THINK
THE BEST THREAT WILL BE ACROSS SOUTHWEST MINNESOTA CLOSEST TO THE
BEST FORCING...BUT GIVEN INSTABILITY TO THE SOUTHWEST...AND SOME OF
THE HI RES MODELS SHOWING CONVECTION FIRING IN OUR WEST...WILL KEEP
CHANCE POPS ACROSS THE WHOLE CWA. CONFIDENCE IS TOO LOW IN PLACEMENT
AND TIMING TO WARRANT ANY LIKELY POPS AT THIS TIME. ELEVATED
INSTABILITY AROUND 1000 J/KG TONIGHT WOULD SUGGEST A PRETTY GOOD
LIGHTNING THREAT WITH ANYTHING THAT DOES FORM TONIGHT...HOWEVER
SEVERE THREAT SHOULD REMAIN PRETTY LOW...WITH THE ELEVATED NATURE
LIMITING WIND THREAT...AND CAPE PROBABLY TOO LOW FOR MUCH OF A HAIL
THREAT. LOWS WILL BE MILDER TONIGHT...GENERALLY LOW AND MID 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN AUG 4 2013
FOR MONDAY...A COLD FRONT DROPS ACROSS THE REGION EARLY IN THE
DAY...AND OTHER THAN A SLIGHT CHANCE OF POPS IN THE SOUTH AND EAST
EARLY THINK THAT THE REMAINDER OF THE DAY WILL BE DRY IN
SUBSIDENCE/DRYING BEHIND AN EXITING SHORTWAVE. ONLY WEAK COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH MORE SUN THAN TODAY
TEMPERATURES WILL WARM INTO THE UPPER 70S TO MID 80S ACROSS THE AREA
BY AFTERNOON. MOSTLY CLEAR SKIES WILL RULE FOR THE FIRST HALF OF
MONDAY NIGHT...BEFORE CLOUDS BEGIN TO INCREASE IN THE WEST THE
LATTER HALF OF THE NIGHT WITH MID LEVEL WARM AIR ADVECTION. CANNOT
RULE OUT THAT ISOLATED THUNDERSTORMS COULD MAKE IT INTO OUR FAR WEST
BY EARLY TUESDAY MORNING WITH THETA E ADVECTION ON A DEVELOPING LOW
LEVEL JET THROUGH WESTERN SOUTH DAKOTA. LOWS ON MONDAY NIGHT LOOKING
TO BE IN THE UPPER 50S TO LOWER 60S.
ANOTHER COLD FRONT ENCROACHES ON OUR AREA BY TUESDAY AFTERNOON...AND
MAY HAVE BETTER CHANCE OF THUNDERSTORMS ACROSS THE AREA WITH
INCREASING 850 MB THETA E ADVECTION AND INCREASING INSTABILITY OUT
AHEAD OF THE SYSTEM...WITH UPPER LEVEL SUPPORT AS A SHORTWAVE TRACKS
OVER THE AREA. THEIR DOES APPEAR TO BE ENOUGH CAPE AND SHEAR IN OUR
SOUTH AND WEST IN THE AFTERNOON THAT SEVERE STORMS WOULD BE
POSSIBLE. THERMAL PROFILES WARM JUST A BIT OUT AHEAD OF THE
FRONT...THOUGH HIGHS WILL BE DEPENDENT ON TIMING AND EVOLUTION OF
CONVECTION...BUT POTENTIALLY WILL REACH THE UPPER 70S TO MID 80S.
THE FRONTAL BOUNDARY WILL FINALLY PULL ACROSS THE AREA ON TUESDAY
EVENING WITH ANY CONVECTION ENDING FROM WEST TO EAST.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT
AGREEMENT ON THE DEVELOPMENT OF A CLOSED UPPER LEVEL LOW OVER
CENTRAL CANADA FOR MIDWEEK. THIS FEATURE WILL THEN SLOWLY MIGRATE TO
THE NORTHERN GREAT LAKES REGION BY THE END OF THE WEEK. THIS WILL
KEEP OUR AREA IN A NORTHWESTERLY UPPER LEVEL FLOW WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD. DOES NOT APPEAR TO BE ANY
OUTSTANDING CHANCES OF PRECIPITATION THROUGH THE EXTENDED...THOUGH
THE BEST CHANCE WOULD LOOK TO BE IN THE THURSDAY TO THURSDAY NIGHT
TIME FRAME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 644 AM CDT SUN AUG 4 2013
AREA OF SHOWERS AND EMBEDDED THUNDER MOVING EAST ACROSS THE CWA THIS
MORNING. THINK IT WILL CONTINUE TO WEAKEN AND DISSIPATE AS IT MOVES
INTO THE DRYER AND MORE STABLE AIR IN THE EAST. A FEW SHOWERS MAY
MAKE IT TO INTERSTATE 29 BETWEEN 8 AM AND 11 AM...BUT SHOULD
DISSIPATE AFTER THEN. NOT EXPECTING ANY LIGHTNING TO IMPACT THE TAF
SITES WITH THIS ACTIVITY. TONIGHT...WE MAY SEE ANOTHER ROUND OF
STORMS MOVE THROUGH FROM NORTHWEST TO SOUTHEAST. CONFIDENCE IN
COVERAGE AND TIMING IS CURRENTLY TOO LOW TO PUT A MENTION IN THE
TAFS. GUIDANCE IS SUGGESTING WE COULD SEE SOME MVFR STRATUS MOVE IN
AHEAD OF THE COLD FRONT TONIGHT. HOWEVER NOT COMPLETELY SOLD ON THAT
HAPPENING...SO WILL KEEP THE TAF VFR FOR THE TIME BEING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...CHENARD
LONG TERM...JM
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
649 AM CDT SUN AUG 4 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN AUG 4 2013
MODELS STRUGGLING WITH ONGOING ACTIVITY ACROSS CENTRAL SOUTH DAKOTA
WHICH HAS DEVELOPED WITH AN INCREASING LOW LEVEL JET AND MID LEVEL
WAVE. DRY AIR TO THE EAST AND MINIMAL INSTABILITY IS EXPECTED TO
CAUSE A DOWNWARD TREND IN THIS CONVECTION AS IT ENTERS OUR CWA. OF
ALL THE GUIDANCE...SEEMS LIKE HRRR IS CLOSEST TO REALITY...WITH THE
0Z ECMWF ALSO NOT TOO BAD. BOTH OF THESE MODELS SUGGEST ACTIVITY
DOES INDEED WEAKEN AND DISSIPATE AS IT PUSHES EAST. HAVE HIGH CHANCE
TO LIKELY POPS THIS MORNING WEST OF THE JAMES RIVER...FROM ABOUT 10Z
TO 15Z. NOTHING SEVERE BUT WOULD EXPECT AT LEAST SOME LIGHTNING
ACTIVITY WITH THE STORMS. SHOWERS COULD MAKE IT AS FAR EAST AS
INTERSTATE 29 BY 13Z...BUT NOT REAL CONFIDENT IT WILL HOLD TOGETHER
EVEN THAT FAR...SO WILL ONLY GO SLIGHT CHANCE POPS. PLUS GIVEN THE
EXPECTED WEAKENING STATE...AND LACK OF INSTABILITY...PROBABLY WILL
NOT BE ANY LIGHTNING WITH ANYTHING THAT DOES MANAGE TO GET EAST OF
THE JAMES RIVER. TEND TO THINK WE SEE A LULL IN THE ACTIVITY DURING
THE AFTERNOON HOURS. BUT GIVEN WEAK FORCING...MID LEVEL MOISTURE
PRESENT...ONGOING ACTIVITY CONTINUING TO DEVELOP OVER NORTHWEST
SOUTH DAKOTA...AND THE GENERALLY LOW PREDICTABILITY OF THE
PATTERN...WILL KEEP A LOW CHANCE POPS IN THE WEST THROUGH THE
DAY...WITH SLIGHT CHANCES TO INTERSTATE 29. DAY SHIFT MAY END UP
BEING ABLE TO REMOVE THESE IF IT BECOMES MORE APPARENT DURING THE
MORNING THAT WE SEE A LULL IN THE ACTION. HIGHS TODAY ARE TRICKY AND
DEPENDENT ON REMNANT CLOUD COVER. THINK IT PROBABLY STAYS MOSTLY
CLOUDY FOR MUCH OF THE DAY. DID BUMP HIGHS UP SOME WITH SOME OF THE
NEWER GUIDANCE COMING IN A BIT WARMER...BUT GIVEN CLOUD COVER
CONCERNS DID NOT WANT TO GO TOO WARM...AND WENT WITH MAINLY MID AND
UPPER 70S. IF WE SOMEHOW ARE ABLE TO GET MORE SUN TODAY...HIGHS
WOULD END UP SEVERAL DEGREES WARMER. SO ANOTHER THING THE DAY SHIFT
WILL HAVE TO MONITOR.
UNFORTUNATELY...FORECAST CONFIDENCE DOES NOT INCREASE TONIGHT. THE
CORE OF THE UPPER LEVEL SUPPORT WILL DIVE SOUTHEAST ACROSS
MINNESOTA. SEEMS LIKE A GOOD BET THAT WE SEE ANOTHER ROUND OF
NOCTURNAL CONVECTION ACROSS THE NORTHERN PLAINS. BEST FORCING IS TO
THE NORTHEAST...WITH BEST INSTABILITY AS YOU GO SOUTHWEST. THINK
THE BEST THREAT WILL BE ACROSS SOUTHWEST MINNESOTA CLOSEST TO THE
BEST FORCING...BUT GIVEN INSTABILITY TO THE SOUTHWEST...AND SOME OF
THE HI RES MODELS SHOWING CONVECTION FIRING IN OUR WEST...WILL KEEP
CHANCE POPS ACROSS THE WHOLE CWA. CONFIDENCE IS TOO LOW IN PLACEMENT
AND TIMING TO WARRANT ANY LIKELY POPS AT THIS TIME. ELEVATED
INSTABILITY AROUND 1000 J/KG TONIGHT WOULD SUGGEST A PRETTY GOOD
LIGHTNING THREAT WITH ANYTHING THAT DOES FORM TONIGHT...HOWEVER
SEVERE THREAT SHOULD REMAIN PRETTY LOW...WITH THE ELEVATED NATURE
LIMITING WIND THREAT...AND CAPE PROBABLY TOO LOW FOR MUCH OF A HAIL
THREAT. LOWS WILL BE MILDER TONIGHT...GENERALLY LOW AND MID 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN AUG 4 2013
FOR MONDAY...A COLD FRONT DROPS ACROSS THE REGION EARLY IN THE
DAY...AND OTHER THAN A SLIGHT CHANCE OF POPS IN THE SOUTH AND EAST
EARLY THINK THAT THE REMAINDER OF THE DAY WILL BE DRY IN
SUBSIDENCE/DRYING BEHIND AN EXITING SHORTWAVE. ONLY WEAK COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH MORE SUN THAN TODAY
TEMPERATURES WILL WARM INTO THE UPPER 70S TO MID 80S ACROSS THE AREA
BY AFTERNOON. MOSTLY CLEAR SKIES WILL RULE FOR THE FIRST HALF OF
MONDAY NIGHT...BEFORE CLOUDS BEGIN TO INCREASE IN THE WEST THE
LATTER HALF OF THE NIGHT WITH MID LEVEL WARM AIR ADVECTION. CANNOT
RULE OUT THAT ISOLATED THUNDERSTORMS COULD MAKE IT INTO OUR FAR WEST
BY EARLY TUESDAY MORNING WITH THETA E ADVECTION ON A DEVELOPING LOW
LEVEL JET THROUGH WESTERN SOUTH DAKOTA. LOWS ON MONDAY NIGHT LOOKING
TO BE IN THE UPPER 50S TO LOWER 60S.
ANOTHER COLD FRONT ENCROACHES ON OUR AREA BY TUESDAY AFTERNOON...AND
MAY HAVE BETTER CHANCE OF THUNDERSTORMS ACROSS THE AREA WITH
INCREASING 850 MB THETA E ADVECTION AND INCREASING INSTABILITY OUT
AHEAD OF THE SYSTEM...WITH UPPER LEVEL SUPPORT AS A SHORTWAVE TRACKS
OVER THE AREA. THEIR DOES APPEAR TO BE ENOUGH CAPE AND SHEAR IN OUR
SOUTH AND WEST IN THE AFTERNOON THAT SEVERE STORMS WOULD BE
POSSIBLE. THERMAL PROFILES WARM JUST A BIT OUT AHEAD OF THE
FRONT...THOUGH HIGHS WILL BE DEPENDENT ON TIMING AND EVOLUTION OF
CONVECTION...BUT POTENTIALLY WILL REACH THE UPPER 70S TO MID 80S.
THE FRONTAL BOUNDARY WILL FINALLY PULL ACROSS THE AREA ON TUESDAY
EVENING WITH ANY CONVECTION ENDING FROM WEST TO EAST.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT
AGREEMENT ON THE DEVELOPMENT OF A CLOSED UPPER LEVEL LOW OVER
CENTRAL CANADA FOR MIDWEEK. THIS FEATURE WILL THEN SLOWLY MIGRATE TO
THE NORTHERN GREAT LAKES REGION BY THE END OF THE WEEK. THIS WILL
KEEP OUR AREA IN A NORTHWESTERLY UPPER LEVEL FLOW WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD. DOES NOT APPEAR TO BE ANY
OUTSTANDING CHANCES OF PRECIPITATION THROUGH THE EXTENDED...THOUGH
THE BEST CHANCE WOULD LOOK TO BE IN THE THURSDAY TO THURSDAY NIGHT
TIME FRAME.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 644 AM CDT SUN AUG 4 2013
AREA OF SHOWERS AND EMBEDDED THUNDER MOVING EAST ACROSS THE CWA THIS
MORNING. THINK IT WILL CONTINUE TO WEAKEN AND DISSIPATE AS IT MOVES
INTO THE DRYER AND MORE STABLE AIR IN THE EAST. A FEW SHOWERS MAY
MAKE IT TO INTERSTATE 29 BETWEEN 8 AM AND 11 AM...BUT SHOULD
DISSIPATE AFTER THEN. NOT EXPECTING ANY LIGHTNING TO IMPACT THE TAF
SITES WITH THIS ACTIVITY. TONIGHT...WE MAY SEE ANOTHER ROUND OF
STORMS MOVE THROUGH FROM NORTHWEST TO SOUTHEAST. CONFIDENCE IN
COVERAGE AND TIMING IS CURRENTLY TOO LOW TO PUT A MENTION IN THE
TAFS. GUIDANCE IS SUGGESTING WE COULD SEE SOME MVFR STRATUS MOVE IN
AHEAD OF THE COLD FRONT TONIGHT. HOWEVER NOT COMPLETELY SOLD ON THAT
HAPPENING...SO WILL KEEP THE TAF VFR FOR THE TIME BEING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...JM
AVIATION...CHENARD
SEE THE 12Z AVIATION FORECAST DISCUSSION BELOW.
40
&&
.AVIATION...
DEEPER LAYER MOISTURE AS SEEN BY THE WATER VAPOR AND THE 00Z LCH
SOUNDING WILL HELP BRING SLIGHTLY BETTER CHANCES FOR SHOWERS
TODAY. COULD NOT RULE OUT THUNDER BUT WENT WITH VCSH FOR NOW FOR
THE BIG AIRPORTS TO THE COAST. OUTSIDE OF THE RAIN CHANCES...WINDS
ARE THE MAIN PROBLEM OF THE DAY. WENT MAINLY WITH PERSISTENCE IN
TRYING TO TIME THE SEABREEZE. A DECENT THERMAL GRADIENT WILL BE
THE MAIN DRIVER FOR THE SLIGHTLY HIGHER WIND SPEEDS FOR SOME
LOCATIONS THIS AFTERNOON AND EARLY EVENING. OTHERWISE...VFR WITH
A CHANCE OF A SCATTERED MVFR DECK BEFORE 15Z TODAY.
40
&&
.PREV DISCUSSION... /ISSUED 345 AM CDT SUN AUG 4 2013/
DISCUSSION...
A VERY WARM START TO THE MORNING AS MOST SITES ARE STILL IN THE
LOWER 80S. HEAT INDEX VALUES AT 3 AM RANGED FROM THE UPPER 80S TO
THE UPPER 90S (97 - KGLS). SURFACE HIGH PRESSURE WAS LOCATED OVER
THE CENTRAL GULF OF MEXICO WITH LOWER PRESSURE OVER SOUTHWEST
TEXAS. 850 MB TEMPS ARE A DEGREE COOLER THAN LAST NIGHT AND DEEPER
850 MB MOISTURE WAS OVER SOUTHWEST LOUISIANA. A 700 MB HIGH WAS
CENTERED OVER EASTERN OKLAHOMA AND DEEPER 700 MB MOISTURE WAS
AGAIN OVER SOUTHWEST LOUISIANA. 700 MB TEMPS HAD COOLED FURTHER AT
BOTH KLCH AND KSHV. A STRONG UPPER LEVEL HIGH REMAINS NEARLY
STATIONARY OVER WEST CENTRAL TEXAS. FCST SOUNDINGS FOR THIS AFTN
SHOW PW VALUES PEAKING NEAR 2.00 INCHES WITH K INDEX VALUES FROM
34 TO 38. THE HRRR... RAP AND 4 KM WRF ALL BRING SHRA/TSRA INTO SE
TX LATE THIS MORNING INTO THE AFTN. THE DEEPER MOISTURE TO THE
EAST WILL MOVE INTO SE TX LATER THIS MORNING. SHRA/TSRA ARE
EXPECTED TO DEVELOP THIS MORNING ONCE HEATING COMMENCES. STILL A
GREAT DEAL OF CONCERN THAT THE MAMMOTH UPPER RIDGE WILL IMPART
SUBSIDENCE AND THIS COULD LIMIT DEVELOPMENT. A FEW MORE CLOUDS AND
DEEPER MOISTURE WILL HINDER HEATING SO SHAVED A FEW DEGREES FROM
YESTERDAYS VALUES.
UPPER LEVEL RIDGING WILL REMAIN IN CONTROL FOR THE REST OF THE
WEEK. STILL SOME MOISTURE AROUND ON MONDAY BUT AS THE CENTER OF
THE UPPER RIDGE NUDGES CLOSER...FEEL SUBSIDENCE WILL END ANY
POTENTIAL FOR SHOWERS. 850 MB TEMPS SLOWLY WARM THROUGH THURSDAY
AND 850 MB WINDS VEER TO THE SOUTHWEST. TUE-THU CONTINUE TO LOOK
VERY WARM WITH 100 DEGREE HEAT RETURNING OR CONTINUING FOR MOST OF
THE AREA. HEAT INDEX VALUES LOOK TO GET NEAR ADVISORY CRITERIA
MID WEEK.
850 MB WINDS TURN TO THE SOUTHEAST ON FRIDAY AND THE UPPER RIDGE
RETREATS EVER SO SLIGHTLY. MOISTURE LEVELS WILL BEGIN TO DEEPEN SO
TRENDED MAX TEMPS SLIGHTLY COOLER FOR FRIDAY. A WEAK DISTURBANCE
MOVING INTO THE REGION FROM THE EAST WILL BRING THE AREA A SLIGHT
CHANCE OF RAIN ON SAT/SUN. THE RIDGE STILL LOOKS TOO STRONG AND
THE DISTURBANCE WILL PROBABLY BE SHUNTED SOUTH OF THE AREA. THAT
SAID...DEEPER MSTR WILL STILL FILTER INTO SE TX NEXT WEEKEND WITH
SLIGHTLY COOLER TEMPS AND A SLIGHT CHANCE OF RAIN. 43
MARINE...
ONSHORE WINDS EXPECTED TO CONTINUE WITH THE SURFACE RIDGE EXTENDING
ACROSS THE NORTHERN GULF OF MEXICO. THE THERMAL GRADIENT WILL HELP
TO GENERATE A DAILY CYCLE OF LIGHTER WINDS IN THE LATE MORNING TO
EARLY AFTERNOON AND MODERATE WINDS FROM THE LATE AFTERNOON THROUGH
THE EVENING. WITH A DEEPER LAYER OF MOISTURE AND A WEAK BOUNDARY
ABOVE THE SURFACE...DO EXPECT ISOLATED SHOWERS THIS MORNING.
40
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 99 76 100 76 101 / 10 10 10 10 0
HOUSTON (IAH) 96 77 97 77 99 / 20 10 10 10 0
GALVESTON (GLS) 92 83 93 82 92 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS ALBANY NY
320 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT MOVES
ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS WILL
OCCUR...BUT MOST OF THE TIME IT WILL BE RAIN FREE. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 115 PM...A BKN LINE OF SHOWERS/TSTMS EXTENDED FROM NRN NH TO
SOUTHERN VT AND THEN TO THE SOUTHEAST CATSKILLS. THIS LINE SHOWS UP
WELL ON STLT PICS AS WELL. HAVE RAISED POPS TO 50 PERCENT OVER THE
CENTRAL PART OF THE FORECAST AREA AND 40 PERCENT OVER THE SOUTHEAST.
OTHERWISE NO CHANGES MADE TO THE PREVIOUS GRIDDED FORECASTS.
.PREVIOUS DISCUSSION...
FOR ALL THESE REASONS...WILL KEEP CHANCE SHOWER/THUNDER WITH THE
MENTION OF SMALL HAIL WITH THIS PACKAGE. HOURLY TEMPERATURES WERE
GENERALLY RUNNING 3 DEGREES OR HIGHER THAN THE PREVIOUSLY PROJECTED
HOURLY TEMPS SO WENT AHEAD RE-TOOLED. DID RAISE A FEW TEMPERATURES
2-3 DEGREES...MAINLY IN THE MID HUDSON VALLEY. OTHERWISE LEFT THEM
ALONE.
LOOK FOR HIGH TEMPERATURES 70 TO 75 VALLEY AREAS...UPPER 70S MID
HUDSON VALLEY BUT ONLY IN THE 60S ACROSS THE ELEVATED TERRAIN. A
BREEZE WILL PICK UP FROM THE NORTHWEST 10 TO 15 MPH...GUSTING TO 25
OR MORE IN MORE WIND PRONE AREAS. THE RUC13 SUGGESTS SBCAPES AROUND
1K J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...A CLEARING SKY THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A DISCRETE SURFACE TROUGH AND UPPER LEVEL DISTURBANCE HAS TRIGGERED
SHOWERS AND THUNDERSTORMS ACROSS KGFL AND KALB ALREADY TODAY. THIS
BROKEN LINE HAS PUSHED SOUTH AND EAST OF THESE TAF SITES AND COULD
IMPACT KPSF/KPOU SOON. BEHIND THIS FEATURE STILL SOME WIDELY
SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM SO HAVE ASSIGNED VCSH
TO THE TAFS UNTIL 22Z-00Z (LATEST AT KPSF AND KPOU). THESE SHOWERS
AND STORMS COULD BRIEFLY LOWER CONDITIONS TO MVFR OR PERHAPS
IFR...BUT ONLY FOR A VERY BRIEF TIME.
A GUSTY NORTHWEST BREEZE 10-15 KTS WILL DIMINISH TOWARD DAYBREAK AS
WELL.
OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. SCT-BKN
CU BASES GENERALLY AROUND 5000 FEET WILL DISSIPATE TOWARD DARK. WE
ARE CONCERNED ABOUT IFR AT MAINLY KGFL OVERNIGHT BUT PROBABLY JUST
ENOUGH MIXING TO PREVENT IFR FOG AT THE OTHER SITES.
ANY FOG DISSIPATE BY DAYBREAK TOMORROW WITH A GREAT FLYING DAY ON
TAP. THE DAY WILL SEE FEW IF ANY SENSIBLE CLOUDS...UNRESTRICTED
VISIBILITY AND A NORTH TO NORTHWEST WIND 10KTS OR LESS.
OUTLOOK...
MONDAY NIGHT: LOW OPERATIONAL IMPACT. NO SIG WX.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WEDNESDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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/BGM
NEAR TERM...GJM/HWJIV/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
FIRE WEATHER...FRUGIS
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
152 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT MOVES
ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS WILL
OCCUR...BUT MOST OF THE TIME IT WILL BE RAIN FREE. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 115 PM...A BKN LINE OF SHOWERS/TSTMS EXTENDED FROM NRN NH TO
SOUTHERN VT AND THEN TO THE SOUTHEAST CATSKILLS. THIS LINE SHOWS UP
WELL ON STLT PICS AS WELL. HAVE RAISED POPS TO 50 PERCENT OVER THE
CENTRAL PART OF THE FORECAST AREA AND 40 PERCENT OVER THE SOUTHEAST.
OTHERWISE NO CHANGES MADE TO THE PREVIOUS GRIDDED FORECASTS.
.PREVIOUS DISCUSSION...
FOR ALL THESE REASONS...WILL KEEP CHANCE SHOWER/THUNDER WITH THE
MENTION OF SMALL HAIL WITH THIS PACKAGE. HOURLY TEMPERATURES WERE
GENERALLY RUNNING 3 DEGREES OR HIGHER THAN THE PREVIOUSLY PROJECTED
HOURLY TEMPS SO WENT AHEAD RE-TOOLED. DID RAISE A FEW TEMPERATURES
2-3 DEGREES...MAINLY IN THE MID HUDSON VALLEY. OTHERWISE LEFT THEM
ALONE.
LOOK FOR HIGH TEMPERATURES 70 TO 75 VALLEY AREAS...UPPER 70S MID
HUDSON VALLEY BUT ONLY IN THE 60S ACROSS THE ELEVATED TERRAIN. A
BREEZE WILL PICK UP FROM THE NORTHWEST 10 TO 15 MPH...GUSTING TO 25
OR MORE IN MORE WIND PRONE AREAS. THE RUC13 SUGGESTS SBCAPES AROUND
1K J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...A CLEARING SKY THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A DISCRETE SURFACE TROUGH AND UPPER LEVEL DISTURBANCE HAS TRIGGERED
SHOWERS AND THUNDERSTORMS ACROSS KGFL AND KALB ALREADY TODAY. THIS
BROKEN LINE HAS PUSHED SOUTH AND EAST OF THESE TAF SITES AND COULD
IMPACT KPSF/KPOU SOON. BEHIND THIS FEATURE STILL SOME WIDELY
SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM SO HAVE ASSIGNED VCSH
TO THE TAFS UNTIL 22Z-00Z (LATEST AT KPSF AND KPOU). THESE SHOWERS
AND STORMS COULD BRIEFLY LOWER CONDITIONS TO MVFR OR PERHAPS
IFR...BUT ONLY FOR A VERY BRIEF TIME.
A GUSTY NORTHWEST BREEZE 10-15 KTS WILL DIMINISH TOWARD DAYBREAK AS
WELL.
OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. SCT-BKN
CU BASES GENERALLY AROUND 5000 FEET WILL DISSIPATE TOWARD DARK. WE
ARE CONCERNED ABOUT IFR AT MAINLY KGFL OVERNIGHT BUT PROBABLY JUST
ENOUGH MIXING TO PREVENT IFR FOG AT THE OTHER SITES.
ANY FOG DISSIPATE BY DAYBREAK TOMORROW WITH A GREAT FLYING DAY ON
TAP. THE DAY WILL SEE FEW IF ANY SENSIBLE CLOUDS...UNRESTRICTED
VISIBILITY AND A NORTH TO NORTHWEST WIND 10KTS OR LESS.
OUTLOOK...
MONDAY THROUGH TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY THROUGH THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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/BGM
NEAR TERM...GJM/HWJIV/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
FIRE WEATHER...FRUGIS
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS ALBANY NY
142 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER AIR MASS WILL FILTER INTO THE REGION AS A COLD FRONT MOVES
ACROSS THE REGION TODAY. A FEW SHOWERS AND THUNDERSTORMS ARE
POSSIBLE...BUT MOST OF THE TIME IT SHOULD REMAIN DRY. BELOW NORMAL
TEMPERATURES FOR THIS TIME OF THE YEAR WILL CONTINUE INTO EARLY NEXT
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 945 AM EDT...SHOWERS HAD DISSIPATED TO THE EAST OF LAKE
ONTARIO. HOWEVER...ANOTHER CLUSTER HAS DEVELOPED IN ONEIDA COUNTY.
CLOUDS WERE BEGINNING TO PERCOLATE AS THE MID LEVELS OF THE
ATMOSPHERE COOL...STEEPENING THE LOW LEVEL LAPSE AND INSTABILITY.
ALSO...H20 WATER VAPOR LOOP INDICATES A SERIES OF DISTURBANCES
HEADING WAY LATER TODAY.
FOR ALL THESE REASONS...WILL KEEP CHANCE SHOWER/THUNDER WITH THE
MENTION OF SMALL HAIL WITH THIS PACKAGE. HOURLY TEMPERATURES WERE
GENERALLY RUNNING 3 DEGREES OR HIGHER THAN THE PREVIOUSLY PROJECTED
HOURLY TEMPS SO WENT AHEAD RE-TOOLED. DID RAISE A FEW TEMPERATURES
2-3 DEGREES...MAINLY IN THE MID HUDSON VALLEY. OTHERWISE LEFT THEM
ALONE.
LOOK FOR HIGH TEMPERATURES 70 TO 75 VALLEY AREAS...UPPER 70S MID
HUDSON VALLEY BUT ONLY IN THE 60S ACROSS THE ELEVATED TERRAIN. A
BREEZE WILL PICK UP FROM THE NORTHWEST 10 TO 15 MPH...GUSTING TO 25
OR MORE IN MORE WIND PRONE AREAS. THE RUC13 SUGGESTS SBCAPES AROUND
1K J/KG WITH WET BULB ZERO HEIGHTS FALLING TO NEAR 8K FEET BY EARLY
AFTERNOON SO THE MENTION OF SMALL HAIL REMAINS IN THE FORECAST.
WITH THE LOSS OF DAYTIME HEATING AND PASSAGE OF THE LAST IN THE
SERIES OF FROPA/S...A CLEARING SKY THIS EVENING. WINDS SHOULD
DECOUPLE AS WE WATCH TEMPERATURES FALL RATHER QUICKLY AS DEWPOINTS
DROP BACK INTO THE 40S. LOWS OVERNIGHT WILL MAINLY BE IN THE 40S
WITH AROUND 50 FOR THE IMMEDIATE CAPITAL REGION AND POINTS SOUTH
ALONG THE HUDSON RIVER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY/...
A LARGE CANADIAN HIGH PRESSURE SYSTEM WILL BUILD INTO THE REGION AND
CONTROL OUR WEATHER MONDAY THROUGH MONDAY NIGHT. A MAINLY CLEAR
SKY IS FORECAST BUT IT WILL BE COOL DURING
THIS PERIOD WITH LOWS GENERALLY IN THE 40S TO AROUND 50. HIGHS
IN THE UPPER 60S AND MID 70S...WITH A GRADUAL INCREASE EXPECTED
TUESDAY AFTERNOON.
WARM ADVECTION IS EXPECTED TO UNFOLD UPSTREAM OF THE CWFA WITH
VARIOUS MODELS VARYING ON THE TIMING OF THIS WITH THE LATEST
ECMWF/GGEM THE SLOWEST WITH THE ONSET OF THIS WAA. WE WILL PLACE A
SLIGHT CHANCE POPS FOR PORTIONS OF THE SCHOHARIE VALLEY...WESTERN
MOHAWK VALLEY AND ADIRONDACKS DURING THE AFTERNOON HOURS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL START TO SHIFT EAST OF THE AREA ON TUESDAY NIGHT.
THIS WILL ALLOW FOR A MOIST SOUTHERLY FLOW TO RETURN TO THE
REGION...WHICH WILL START TO INCREASE THE CLOUDS AND RETURN THE
THREAT FOR RAINFALL. STILL...MOST AREAS WILL HAVE ANOTHER COOL NIGHT
ON TUES NIGHT WITH MINS IN THE UPPER 40S TO UPPER 50S...AS THE
CLOUDS WON/T BE TOO THICK JUST YET AND ANY SHOWER ACTIVITY LOOKS
RATHER SCATTERED IN NATURE AND LIMITED TO JUST SOUTHWESTERN PARTS OF
THE AREA.
A WARM FRONT WILL MOVE ACROSS THE AREA FOR WEDNESDAY. THE BEST CHC
OF SEEING A SHOWER WILL BE FOR SOUTHERN AND WESTERN AREAS. MAX TEMPS
LOOK SIMILAR TO RECENT DAYS WITH 70S FOR MOST PLACES ALTHOUGH IT
WILL START TO FEEL A LITTLE MORE MUGGY THAN RECENT DAYS...WITH
DEWPOINTS STARTING TO CREEP UP IN THE 60S.
THE MODELS AREN/T IN EXACT AGREEMENT REGARDING THE TIMING OF A COLD
FRONT. AT SOME POINT BETWEEN WED NIGHT AND THURSDAY NIGHT...A COLD
FRONT LOOKS TO MOVE ACROSS THE REGION. A WAVE OF LOW PRESSURE MAY
DEVELOP ALONG THIS BOUNDARY...INCREASING THE THREAT FOR SHOWERS AND
THUNDERSTORMS. WITH PWAT VALUES RISING TO NEARLY TWO INCHES...HEAVY
RAINFALL MAY ACCOMPANY ANY OF THE SHOWERS OR THUNDERSTORMS.
DEPENDING ON THE AMOUNT OF INSTABILITY AND TIMING OF THE FRONT ON
THURSDAY...WE MAY HAVE TO WATCH FOR THE POTENTIAL FOR SOME STRONG
TSTMS ON THURSDAY AS WELL...ALTHOUGH THE MAIN THREAT LOOKS TO BE
HEAVY RAINFALL AT THIS POINT. MIN TEMPS ON WED NIGHT AND THURSDAY
NIGHT WILL BE MAINLY IN THE 60S...WITH 70S TO LOW 80S DURING THE DAY
ON THURSDAY.
BEHIND THE FRONT...THE THREAT FOR RAIN SHOULD DIMINISH. SOUTHEASTERN
PARTS OF THE AREA MAY CONTINUE TO SEE A THREAT FOR RAIN SHOWERS ON
FRIDAY DEPENDING ON HOW QUICKLY THE FRONT EXITS THE REGION AND IF IT
STALLS NEARBY. DEWPOINTS WILL DROP SOMEWHAT ON FRIDAY...ALTHOUGH
THE BEST PUSH OF DRY AIR MAY NOT ARRIVE UNTIL LATER IN THE WEEKEND.
MAX TEMPS ON FRIDAY WILL BE NEAR NORMAL...WITH VALLEY TEMPS IN THE
LOW 80S.
IT SHOULD BE DRY FOR FRIDAY NIGHT INTO SATURDAY FOR MOST
PLACES...ALTHOUGH AN UPPER LEVEL DISTURBANCE PASSING TO THE NORTH
MAY ALLOW FOR A SHOWER ACROSS THE ADIRONDACKS. TEMPS WILL CONTINUE
RUN CLOSE TO SEASONAL NORMALS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A DISCRETE SURFACE TROUGH AND UPPER LEVEL DISTURBANCE HAS TRIGGERED
SHOWERS AND THUNDERSTORMS ACROSS KGFL AND KALB ALREADY TODAY. THIS
BROKEN LINE HAS PUSHED SOUTH AND EAST OF THESE TAF SITES AND COULD
IMPACT KPSF/KPOU SOON. BEHIND THIS FEATURE STILL SOME WIDELY
SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM SO HAVE ASSIGNED VCSH
TO THE TAFS UNTIL 22Z-00Z (LATEST AT KPSF AND KPOU). THESE SHOWERS
AND STORMS COULD BRIEFLY LOWER CONDITIONS TO MVFR OR PERHAPS
IFR...BUT ONLY FOR A VERY BRIEF TIME.
A GUSTY NORTHWEST BREEZE 10-15 KTS WILL DIMINISH TOWARD DAYBREAK AS
WELL.
OTHERWISE VFR CONDITIONS WILL PREVAIL THROUGH THIS EVENING. SCT-BKN
CU BASES GENERALLY AROUND 5000 FEET WILL DISSIPATE TOWARD DARK. WE
ARE CONCERNED ABOUT IFR AT MAINLY KGFL OVERNIGHT BUT PROBABLY JUST
ENOUGH MIXING TO PREVENT IFR FOG AT THE OTHER SITES.
ANY FOG DISSIPATE BY DAYBREAK TOMORROW WITH A GREAT FLYING DAY ON
TAP. THE DAY WILL SEE FEW IF ANY SENSIBLE CLOUDS...UNRESTRICTED
VISIBILITY AND A NORTH TO NORTHWEST WIND 10KTS OR LESS.
OUTLOOK...
MONDAY THROUGH TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY THROUGH THURSDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...TSRA.
&&
.FIRE WEATHER...
ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS ARE POSSIBLE ON
TODAY AS THE LAST IN A SERIES OF UPPER LEVEL DISTURBANCES MOVES
ACROSS THE REGION.
RH VALUES WILL LOWER TO BETWEEN 45 AND 65 PERCENT ON SUNDAY...AND
RECOVER TO GREATER THAN 90 PERCENT OVERNIGHT.
WEST-NORTHWEST WINDS WILL INCREASE TO 10 TO 20 MPH WITH GUSTS OF
25 TO 30 MPH BY THIS AFTERNOON...AND BECOME LIGHT LATER TONIGHT AS
THE SURFACE RIDGE BUILDS INTO THE REGION.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE EXPECTED THROUGH THE PERIOD.
AS ISOLATED TO SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS WILL
OCCUR TODAY AS ANOTHER IN A SERIES OF UPPER LEVEL DISTURBANCES AND
FRONTAL BOUNDARIES CROSS THE REGION. BASIN AVERAGE QPF AMOUNTS FOR
THE REST OF THE WEEKEND WILL BE UNDER A QUARTER OF AN INCH...SO THE
RAINFALL WILL HAVE LITTLE IMPACT ON AREA STREAMS AND RIVERS. DRY
WEATHER IS EXPECTED MONDAY AND TUESDAY. NEXT CHANCE FOR RAINFALL
ARRIVES LATER WEDNESDAY.
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/BGM
NEAR TERM...HWJIV/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...HWJIV
FIRE WEATHER...FRUGIS
HYDROLOGY...BGM
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
406 PM CDT Sun Aug 4 2013
.SHORT TERM...(This Evening through Monday Night)
Issued at 406 PM CDT SUN AUG 4 2013
Tonight...12Z operational models, especially the NAM, had difficulty
evaluating the mesoscale features from last nights/todays MCS with
double MVC...mesoscale vorticity center...structure. As one would
expect the short range HRRR did a much better job with this system.
The trailing MVC now moving into southeastern KS is aiding
downstream scattered areas of rain from the southern CWA southward
across southern MO. The latest HRRR maintains this area of
precipitation through mid evening and then steadily diminishes it.
Will follow this trend for the evening hours. Thunder chances look
minimal owing to less than stellar instability due to the
rain-cooled airmass and extensive cloud shield.
Looking upstream within the monsoonal flow circulating around the
Southern Plains upper high yields little if any clues for the next
shortwave or disturbance aloft which could generate new convection.
However, believe convection for the overnight hours lies with the
increasing southwesterly low level jet that is expected to form from
the Southern Plains into KS. GFS and NAM output both signal
increasing moisture convergence and isentropic ascent will likely
generate another convective complex. Due to the subsidence left
behind from todays MCS and the models poor handling of this feature
have some question as to where this convection will form. For now
will place my bet on southeastern KS with the activity spreading
into and across mainly the southern CWA. In addition to the rain
tonight am expecting to see MVFR type fog form.
Monday-Monday night...Models show no discernible disturbances
embedded with the northwest flow which will affect the CWA during
the daylight hours. So, rain chances are most likely tied to the
morning hours and across the far southern counties where the combo
of isentropic lift and a weakening low level jet aid a departing
MCS. Have backed off on high temperatures by a handful of degrees as
warm front not likely to move into the CWA and amount of residual
cloud cover will impact surface heating.
The nocturnal low-level jet is expected to reform Monday night and
enhance the lift along/north of the surface front which is expected
to lift northward across central/eastern KS and west central MO
later in the evening. Have moderate confidence this will generate
some healthy convection and will increase PoPs after midnight for
the western counties.
.LONG TERM...(Tuesday through Sunday)
Issued at 406 PM CDT SUN AUG 4 2013
Slight northwest to almost zonal type flow regime will continue
across the central US as the Hudson Bay vortex across southern
Canada will deepen as it slowly progresses towards southern Ontario
and the northern Great Lakes region. A shortwave trough will rotate
along the periphery of this system and help to push a cold front
southeastward through the Central Plains. This front will near the
area by Tuesday night and will be the focus for convective
development Tuesday night into Wednesday morning. The expected MCS
will initially develop north of the CWA, along the front, during the
afternoon and gradually make its way into the CWA as the evening
progresses.
The remainder of the week will see spotty precipitation chances as
the Hudson Bay low gradually moves eastward and ridging remains
positioned across the Rockies. A few shortwave troughs may ride the
ridge and help to initiate convection across the region.
Temperatures will be slightly cooler behind this front as surface
high slides into the region, but will gradually warm into the mid
80s as we near the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1240 PM CDT SUN AUG 4 2013
Complicated and messy forecast. Rain continues to have a hard time
advancing east as drier air advects in from the east. Satellite and
radar trends indicate the area of rain is dissipating. Prefer
following the short range convective allowing HRRR model as it has a
better handle on the MCS generated precipitation that is moving
across eastern KS and western MO. MVFR/IFR cigs upstream are a
concern and think cigs will bounce around between these two
categories at KMCI and KMKC during the early afternoon.
Have little confidence on seeing much if any precipitation after
this afternoon as GFS/NAM having problems resolving the MCS moving
through with the NAM developing way too much precipitation this
evening, thus the dry forecast tonight. Due to the recent rain and
considerable low level moisture left behind plus the light winds
believe MVFR fog likely with IFR cigs. Some question as to how soon
cigs could drop to IFR so amendments can be expected tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
SHORT TERM...MJ
LONG TERM...PMM
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1250 PM CDT Sun Aug 4 2013
.UPDATE...
Issued at 940 AM CDT SUN AUG 4 2013
Lowered temperatures across the southwest 1/3 of the CWA based upon
extensive cloud cover and rain-cooled air. Precipitation shield
associated with KS MCS running into a brick wall of drier air that
covers northern and central MO, courtesy of easterly boundary layer
flow advecting in mid/upper 50 dewpoints, so leading edge of
convection can only creep eastward over the western CWA. Satellite
imagery shows cloud tops have markedly warmed over the past few hours
with a corresponding decrease in precipitation rates. However, cloud
tops have cooled considerably over southwest MO and thus convection
to the south of the CWA has blossomed. 12Z NAM is much more bullish
on rain over the western and central CWA for later this morning and
afternoon but given the current satellite and radar trends I have my
doubts this model is able to handle the MCS feature correctly. Prefer
to side with the latest HRRR output which appears to have a better
handle on precipitation.
&&
.SHORT TERM...(Today through Monday Afternoon)
Issued at 323 AM CDT SUN AUG 4 2013
Shortwave energy crossing the Central Plains today will bring an
increasing chance for rain to much of eastern Kansas and the western
half of Missouri today. Early this morning, a widespread area of
showers and thunderstorms continued to slowly cross central Kansas
as a shortwave visible in WV approached western Kansas. Regional VAD wind
profile data indicated that 850mb winds were finally veering this
morning in response to the shortwave. This directional turn suggests
a northward shift in the 850 baroclinic zone towards the area, with
increasing isentropic lift allowing for scattered showers to develop
across southern Nebraska and NE Kansas.
Today: Low level winds will continue to slowly veer this morning as
the shortwave tracks east southeast into central Kansas. Rain
chances will gradually increase through the morning hours as
low-level flow finally turns southwest by mid-late morning.
However, given the track of the shortwave and fairly pronounced
influences of high pressure centered over the Great Lakes, some
questions remain as to how far east rain will track today. Models
suggest highest precip chances will focus themselves during the late
morning through mid-aftn hours.
Tonight: Despite a departing shortwave, an increasing low level jet
should interact with considerable low-mid level moisture in the
region to allow for redevelopment of thunderstorms over west central
Missouri. The prevailing flow should take this activity into the
Ozarks by daybreak Monday.
Monday: The majority of Monday will likely be warm, humid but dry.
Low level thermal ridge axis stretched across the CWA will promote
rather warm temperatures approaching the 90s in some areas. A weak
surface trough and perhaps remnant outflow from overnight convection
will be a focal point for potential thunderstorm development late
Monday afternoon into Monday evening.
.LONG TERM...(Monday Evening through Saturday)
Issued at 323 AM CDT SUN AUG 4 2013
Most models agree on a weak wave tracking across the area Monday
night while a weak low-level jet noses into eastern KS. This could
support another wave of convection Monday evening particularly
across areas south of I-70. Better chances for thunderstorms still
appear in store Tuesday evening and overnight as a cold front moves
through. Better chances for widespread storms will be north of
Highway 36 where the front will arrive sooner and have better
instability to work with. Instability and shear profiles are
supportive of a large convective system with damaging winds coming
out of Nebraska and Iowa, which could survive after dark as far
south as the Missouri River.
Medium range models continue to show a rather extensive surface high
building in from the north Wednesday through Friday. This should act
to keep things mostly dry once lingering storms clear out from north
to south on Wednesday. Boundary should stall over the Ozarks on
Thursday, which could support additional storms across that region
through the end of the week. Better chances for rain through this
time should stay south of the forecast area.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
Issued at 1240 PM CDT SUN AUG 4 2013
Complicated and messy forecast. Rain continues to have a hard time
advancing east as drier air advects in from the east. Satellite and
radar trends indicate the area of rain is dissipating. Prefer
following the short range convective allowing HRRR model as it has a
better handle on the MCS generated precipitation that is moving
across eastern KS and western MO. MVFR/IFR cigs upstream are a
concern and think cigs will bounce around between these two
categories at KMCI and KMKC during the early afternoon.
Have little confidence on seeing much if any precipitation after
this afternoon as GFS/NAM having problems resolving the MCS moving
through with the NAM developing way too much precipitation this
evening, thus the dry forecast tonight. Due to the recent rain and
considerable low level moisture left behind plus the light winds
believe MVFR fog likely with IFR cigs. Some question as to how soon
cigs could drop to IFR so amendments can be expected tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...Dux
LONG TERM...Hawblitzel
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS GLASGOW MT
258 PM MDT SUN AUG 4 2013
.SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH TUESDAY...
AS THE REMNANTS OF THE SHEARED LOW PRESSURE SYSTEM FROM THE
PACIFIC NORTHWEST FIZZLES OUT ALONG THE MONTANA-SASKATCHEWAN
BORDER...VERY SMALL ISOLATED RAIN SHOWERS ARE GETTING A START
ACROSS A FEW PORTIONS OF NORTHEAST MONTANA. THE HRRR MODEL
CONTINUES TO IGNORE THE THIN BAND OF LIGHT RAIN SHOWERS FROM
JORDAN TO CIRCLE TODAY...BUT IS PERSISTENT IN SUPPORTING A LARGER
CLUSTER OF THUNDERSTORMS MOVING FROM NORTHERN PHILLIPS COUNTY
SOUTHEASTWARD THROUGH THE FORT PECK AREA LATER THIS AFTERNOON AND
EVENING. TRIED TO BETTER REPRESENT THESE TRENDS IN THE FORECAST
GRIDS AND PLAN TO ISSUE THE FORECAST WITH A PRE-FIRST PERIOD TO
REPRESENT THIS THINKING TO THE PUBLIC.
TONIGHT...UPPER LEVEL FLOW OVER MONTANA SHOWS A VERY SMALL SCALE
RIDGE INFLUENCE FROM THE SOUTH BETWEEN SYSTEMS BEFORE THE FLOW OVER
OUR REGION FALLS UNDER GREATER INFLUENCE FROM THE LARGE UPPER LOW
COMPLEX TOWARDS THE NORTHEAST...COURTESY OF THE RELATIVELY ARCTIC
INTRUSION FROM THE HUDSON BAY REGION. THE ATTENDANT COLD FRONT
WILL MOVE THROUGH OUR CWA SOMETIME TUESDAY AFTERNOON AND WILL
RESULT IN ABOUT A 10 DEGREE DROP IN DAYTIME TEMPERATURES THROUGH
MOST OF THE WORK WEEK.
AFTER A DRY MONDAY MORNING TOMORROW...THIS OTHER STEERING
INFLUENCE WILL INTRODUCE PERIODS OF SCATTERED SHOWERS AND
THUNDERSTORMS THROUGH PORTIONS OF THE CWA THROUGH THE REMAINDER OF
THE FORECAST PERIOD. FORCING FOR ASCENT WILL REMAIN NEUTRAL OR
MINIMAL AT BEST AND NO SIGNIFICANT WEATHER SYSTEMS ARE EXPECTED TO
IMPACT THE REGION. BMICKELSON
.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...
UPDATE...VERY LITTLE CHANGE IN THE EXTENDED FORECAST. GUIDANCE
KEEPS WITH THE PREVIOUS FORECAST. DID ADD VERY LOW POPS TO THE END
OF THE FORECAST WITH THE SPREAD OF THE GUIDANCE BEING ENOUGH TO
BRING A SLIM CHANCE OF PRECIPITATION. THE ONLY MAJOR CHANGE OTHER
THAN BRUSHING UP THE EDGES WITH CHANGES MADE AROUND THE REGION. PROTON
SYNOPTIC SET UP A CLOSED LOW EXISTS OVER THE THE ONTARIO/MANITOBA
BORDER WITH A COLD FRONT EXTENSION OVER THE UPPER MISSISSIPPI
VALLEY THE NORTHERN US PLAINS AND THE CENTRAL US HIGH PLAINS. COLD
AIR BEHIND THE FRONT WILL SMASH THE INTENSITY OF THE LARGE HEAT
DOME OVER THE FOUR CORNERS AND REDUCING IT TO A RIDGE OVER THE
INTER-MOUNTAIN WEST AND BRITISH COLUMBIA. A LARGE TROUGH IS
DEVELOPING OVER THE GULF OF ALASKA WITH A FAR WEAKER TROUGH OFF
THE COAST OF CALIFORNIA AND THE PACIFIC NORTHWEST.
TUESDAY NIGHT THROUGH FRIDAY... NORTHEAST MONTANA LIES IN A ZONAL
TO NORTHWEST FLOW PATTERN WITH WEAK SHORTWAVES COMING ACROSS ON A
REGULAR BASIS. TIMING OF THE WAVES IS DIFFICULT. HOWEVER... THE
TROUGH OVER ONTARIO AND MANITOBA WILL SEND A COLD FRONT DOWN
THROUGH THE AREA WEDNESDAY EVENING. TEMPERATURES ARE ANTICIPATED
TO COOL OFF BY ABOUT 10 DEGREES POST FRONT FOR HIGHS AND LOWS
WITH THE AFFECT LINGERING THROUGH FRIDAY EVENING. CHANCES FOR RAIN WILL
EXIST ALONG AND BEHIND THE FRONT.
SATURDAY ONWARD... THE LARGE TROUGH OVER ONTARIO WILL PUSH EAST
INTO QUEBEC ALLOWING THE LARGE RIDGE TO THE WEST TO GAIN
INCREASING DOMINION OVER THE NORTHEAST MONTANA WEATHER PATTERN.
EXPECTED TEMPERATURES TO CREEP UPWARDS TO NEAR NORMAL AGAIN WITH
CHANCES FOR RAIN DROPPING SLOWLY. GAH
&&
.AVIATION...
VFR FOR MOST LOCATION THROUGH THE PERIOD. MVFR REMAINS NEAR THE
YELLOWSTONE RIVER AND MISSOURI RIVE CONFLUENCE AREA EARLY THIS
AFTERNOON. THIS AREA OF MVFR SHOULD LIFT TO AN IFR CEILING AROUND
21Z THIS AFTERNOON. CONVECTIVE SHOWERS ARE DOTTED AROUND THE
REGION THIS AFTERNOON...THEREFORE A BRIEF SHOT OF MVFR WITH THESE
SHOWERS ARE POSSIBLE IF THEY HIT A TAF SITE...HOWEVER THE
PROBABILITY OF THIS IS TOO LOW TO PUT INTO THE FORECAST AT THIS
TIME. PROTON
&&
.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
WEATHER.GOV/GLASGOW
AREA FORECAST DISCUSSION
NWS BILLINGS MT
245 PM MDT SUN AUG 4 2013
.SHORT TERM...VALID FOR MON AND TUE...
WATER VAPOR IMAGERY SHOWS WEAK PV MAX MOVING THROUGH NE MT NOW.
THIS ENERGY IS STRUGGLING TO PRODUCE MUCH IN THE WAY OF CONVECTION
AS THE EASTERN MT AIRMASS IS A BIT DRIER AND CERTAINLY MORE CAPPED
THAN YESTERDAY WITH WEAK COLD ADVECTION UNDERWAY. A WEAK
THUNDERSTORM DID DEVELOP OVER THE SNOWY MTNS BUT THIS CELL HAS NOT
BEEN ABLE TO DETACH FROM THE HIGH TERRAIN SO FAR. ASCENT FROM
AFOREMENTIONED SHORTWAVE IS GREATEST IN FAR EASTERN MT THIS
AFTERNOON...WITH DESCENT EXPECTED BY EVENING...SO FORCING IS
MINIMAL. NOT EXPECTING TOO MUCH ACTIVITY INTO THIS EVENING BUT
FOCUS OF POTENTIAL STRONGER TSTMS MAY BE ALONG THE MT/WY BORDER
FROM SHERIDAN COUNTY EASTWARD...IN AN AREA OF HIGHER THETA-E AIR
AND A BIT MORE FAVORABLE LOW LEVEL WIND SHEAR NEAR STALLED SFC
BOUNDARY. HRRR RUNS HAVE BEEN CONSISTENT IN KEEPING DEVELOPMENT
MAINLY IN NE WY...WITH ONLY VERY WEAK CELLS FURTHER NORTH. WILL
KEEP POPS IN LINE WITH THIS THINKING...AND WILL CONTINUE TO
ADVERTISE THE POSSIBILITY OF A STRONGER STORM NEAR THE SE MT/WY
BORDER INTO THE EARLY EVENING. EVENING ACTIVITY SHOULD BE DONE BY
SUNSET AND THE REMAINDER OF THE NIGHT SHOULD BE DRY WITH A TREND
TOWARD RIDGING ALOFT.
HEIGHTS BEGIN TO FALL AGAIN BY TOMORROW AFTERNOON AS BRITISH
COLUMBIA SHORTWAVE DROPS INTO WESTERN MT. SFC HEATING WILL
DESTABILIZE THE AIRMASS ENOUGH TO ALLOW FOR SOME LATE AFTERNOON
AND EVENING SHOWER/TSTM ACTIVITY...WITH ENHANCEMENT BY EVENING
WITH A FRONTAL PASSAGE...THOUGH WITH A DRIER PREFRONTAL AIRMASS
AS WE MIX W-NW MID LEVEL WINDS. FOCUS OF POTENTIAL STRONGER STORMS
WILL AGAIN BE IN FAR SOUTHEAST MT WHERE MOISTURE/INSTABILITY WILL
BE GREATEST ALONG WEAK SFC TROF/AREA OF PRESSURE FALLS. HAVE
RAISED POPS TO SCATTERED ACROSS MUCH OF THE AREA BY MONDAY NIGHT
PER FORCING FROM THE BC SHORTWAVE.
EXPECT ISOLATED SHOWERS/TSTMS ON TUESDAY UNDER CYCLONIC NW FLOW
ALOFT...BUT WITH NOTHING STRONG OR SEVERE AS DEEP MOISTURE/
INSTABILITY AXIS WILL BE SHIFTED WELL INTO THE CENTRAL PLAINS.
TEMPERATURES ON MONDAY WILL JUMP UP WITH PREFRONTAL WARMING AND A
PERIOD OF DOWNSLOPE WINDS. SHOULD SEE TEMPS NEAR 90 DEGREES FOR
THE FIRST TIME IN AWHILE. TUESDAY WILL BE SEVERAL DEGREES COOLER
THOUGH...AND BACK BELOW NORMAL...IN A POST FRONTAL REGIME WITH
SOMEWHAT GUSTY NW WINDS.
JKL
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
NO SIGNIFICANT CHANGES WERE MADE TO THE EXTENDED PERIOD FOR THIS
FORECAST PACKAGE. MODELS CONTINUE TO BE CONSISTENT WITH A
POWERFUL UPPER LOW OVER THE HUDSON BAY AREA DIRECTING OUR OVERALL
WEATHER PATTERN. THIS KEEPS US IN QUASI CYCLONIC TO NORTHWEST FLOW
ALOFT WITH OCCASIONAL BACK DOOR COLD FRONTS SLIPPING INTO EASTERN
MONTANA. THE TIMING AND STRENGTH OF THESE FRONTS ARE IN QUESTION
AS THE GFS AND ECMWF OFFER SOMEWHAT DIFFERENT SOLUTIONS. MAIN
THEME THOUGH IS SAME...COOLER THAN NORMAL AND AT LEAST SOMEWHAT
UNSETTLED. BT
&&
.AVIATION...
EXPECT PARTLY CLEAR SKIES THIS EVENING WITH A SLIGHT CHANCE FOR A
SHOWER OR THUNDERSTORM...MAINLY OVER ROUTES FROM KSHR EASTWARD.
EXPECT MVFR CONDITIONS IN AND NEAR ANY THUNDERSTORM ACTIVITY.
OTHERWISE...VFR CONDITIONS WILL PREVAIL OVERNIGHT. BT
&&
.PRELIMINARY POINT TEMP/POPS...
MON TUE WED THU FRI SAT SUN
-----------------------------------------------------------
BIL 058/090 059/081 057/084 058/079 057/081 058/085 059/086
22/T 32/T 21/U 12/T 22/T 22/T 22/T
LVM 052/088 050/084 051/084 052/083 051/082 051/086 052/086
22/T 32/T 21/B 12/T 22/T 23/T 22/T
HDN 056/092 058/084 054/085 057/081 057/084 058/087 059/088
22/T 32/T 21/U 11/B 22/T 22/T 22/T
MLS 057/091 060/080 056/083 057/079 055/082 058/086 061/087
22/T 32/T 11/U 21/B 22/T 22/T 22/T
4BQ 056/090 058/081 052/083 054/081 053/081 056/085 058/087
32/T 32/T 11/U 11/B 22/T 22/T 22/T
BHK 053/087 058/076 049/077 052/075 051/077 053/079 056/080
22/T 32/T 11/U 21/U 12/T 21/B 22/T
SHR 055/091 055/083 052/084 053/082 053/083 055/087 056/088
32/T 32/T 21/U 22/T 22/T 22/T 22/T
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
345 PM CDT SUN AUG 4 2013
.SYNOPSIS...
LITTLE CHANGE TO THE OVERALL PATTERN IN THE LAST 24 HOURS. UPPER
LEVEL RIDGE REMAINS CENTERED OVER NW TX. SEVERAL SHORT WAVES RIDING
AROUND THE PERIPHERY OF THE RIDGE...WITH GOOD TAP TO TROPICAL
MOISTURE. AT THE SFC SOUTHEASTER FLOW CONTINUES TO PUMP MOISTURE
INTO THE REGION. DEW PTS HAVE CREPT UP INTO THE MID 60S...WITH LOWER
70S ACROSS MUCH OF KANSAS.
&&
.DISCUSSION...
TONIGHT...THE NEXT SHORT WAVE RIDING ACROSS THE CENTRAL ROCKIES
WILL BE THE FOCUS FOR CONVECTION ALONG THE FRONT RANGE. SOME
UNCERTAINTY TO THE SUSTAINABILITY FOR THE STORMS AS THEY MOVE OFF
THE HIGHER TERRAIN. THE HRRR SUGGESTS THE STORMS WILL MAKE IT INTO
WESTERN NEBRASKA...WHILE THE NAM/RUC FAVOR NORTHERN NEB...UTILIZED
THE BLACK HILLS FOR INITIATION. THE NOSE OF THE LL JET OVERNIGHT
FOCUSES NEAR THE NEB/S DAKOTA BORDER AND WILL FAVOR THE NORTHERN
ZONES WITH THE HIGHEST POPS. LOW LEVEL MOISTURE REMAINS EXCELLENT
AND GUIDANCE IN AGREEMENT WITH LOW CLOUDS TO CONTINUE/REDEVELOP
ACROSS THE AREA OVERNIGHT. COULD SEE SOME FOG ACROSS SW NEB AS DEW
POINTS ARE UP A FEW DEGREES FROM THE PAST COUPLE OF DAYS AND
EXPECT TO EASILY SEE 100 PERCENT RH AS TEMPS COOL INTO THE LOWER
TO MID 60S...HOWEVER THE LATEST MOS GUIDANCE HOLD VSBY IN THE 4 TO
6 MILE RANGE AND FORECAST FAVORS THE LOW STRATUS WITH POCKETS OF
FOG. NOT EXPECTING FOG TO BE WIDESPREAD ENOUGH AT THIS TIME TO
INCLUDE IN FORECAST...HOWEVER WILL MONITOR.
MONDAY...LINGERING THUNDERSHOWERS ACROSS NORTH CENTRAL NEBRASKA
SHOULD DECAY IN THE MORNING WHILE STRATUS ELSEWHERE WILL BE SLOW TO
ERODE. ANOTHER SHORT WAVE...A STRONGER SYSTEM...WILL ENTER THE
REGION FOR THE AFTERNOON. AS THE CLOUDS FINALLY BEGIN TO BREAK AND
TEMPS QUICKLY BUMP INTO THE 80S WITH A FEW LOWER 90S ACROSS THE
SW...GROWING INSTABILITY SHOULD BE ENOUGH FOR CONVECTION. SPC HAS
A SLGHT RISK IN PLACE FOR WESTERN NEBRASKA AND AGREE WITH 40 TO
50 KTS OF SHEAR WITH DEW PTS IN THE 60S. THUNDERSTORMS SHOULD
BREAK THE CAP IN THE AFTERNOON. PRECIPITABLE WATER AROUND 130 TO
150 PERCENT OF NORMAL SHOULD BE SUFFICIENT FOR LOCALLY HEAVY
RAINFALL.
MONDAY NIGHT THROUGH WEDNESDAY...DESPITE THE DEEP MOISTURE...THE
MODELS ARE BACKING OFF ON ANY SORT OF WIDESPREAD HP EVENT LATE
MONDAY. IT MAY BE THAT THE CAP IS VERY STRONG IN THE LATEST SOLNS
SHOWING A STRENGTHENING CAP OF 12C TO 14C AT 700 MB ACROSS WRN NEB
AND THE UPPER LEVEL FORCING IS WEAK MONDAY. MODEL BLENDED POPS ARE
AROUND 30 PERCENT AND QPF IS LESS THAN 1/10 OF AN INCH FOR MONDAY
NIGHT.
ON TUESDAY A COLD FRONT WILL DROP THROUGH THE FCST AREA PROVIDING
FOCUS FOR STORM DEVELOPMENT. THE 00Z WEDNESDAY MODEL CONSENSUS SHOWS
THE SFC LOW ACROSS SWRN KS WHICH IS A POST FRONTAL ENVIRONMENT FOR
POPS ACROSS THE FCST AREA. THE GEM...GFS AND ECM ARE KEYING ON
MOISTURE TRAPPED BEHIND THE COLD FRONT ACROSS ERN PTNS OF NCNTL NEB
WHERE THE CAP WILL BE WEAKEST. POPS ARE 40 PERCENT THERE IN THE AFTN
BUT FALL OFF TUESDAY EVENING AS A MCS DROPS SOUTH THRU CNTL AND ERN
NEB.
ALL MODELS SHOW A 12C-14C CAP ACROSS SWRN NEB TUESDAY WHICH IS LIKELY
LIMITING CONVECTION. THIS THERMAL RIDGE WILL DROP SOUTH LATE TUESDAY
AFTN WHICH COULD OPEN UP THE FCST AREA TO MORE WIDESPREAD CONVECTION
THAN INDICATED BY THE MODELS. THE FRONT WILL DROP SOUTH ON THE HEALS
OF A 300 MB JET IN COMBINATION WITH A DEEP UPPER LEVEL LOW DROPPING
THROUGH MANITOBA. THIS PRODUCES 45 TO 55 KT OF 0-6KM BULK SHEAR
TUESDAY AFTN WITH ML CAPE OVER 3000J/KG EAST OF HIGHWAY 83. THE
SHEAR AND CAPE VALUES ARE MUCH WEAKER MONDAY EVENING SO THE BEST
CHANCE FOR SEVERE WEATHER IS TUESDAY ALONG AND EAST OF HIGHWAY 83.
THE DEEP UPPER LEVEL CYCLONE DROPPING THRU MANITOBA WILL PUSH A
STRONG COLD FRONT THROUGH THE FCST AREA WEDNESDAY AND HIGH TEMPS
WILL STRUGGLE TO REACH 80F. HIGHS TUESDAY RISE INTO THE LOWER 90S
SOUTH WITH THE THERMAL RIDGE OVERHEAD. 80S ARE EXPECTED ELSEWHERE.
ANY CONVECTION THAT FIRES SHOULD BE MOSTLY SOUTH AND WEST OF THE
FCST AREA. THERE IS A GLITCH IN THE FORECAST THOUGH. THE 18Z NAM
IS LIFTING A SUBTROPICAL SHORT WAVE THROUGH SWRN NEB WEDNESDAY
AFTN. THE GEM...ECM AND GFS MOVE THIS WAVE THROUGH KS SOUTH OF THE
FCST AREA. FOR THE FCST USES THE CONSENSUS WHICH IS FOR ISOLATED
STORMS ACROSS THE SOUTH WEDNESDAY.
WEDNESDAY NIGHT THROUGH SUNDAY...A NEW DEVELOPMENT IN THE 12Z MODEL
RUNS IS THEY ARE NOT NEARLY AS STRONG WITH A REINFORCING COLD FRONT
THAT WAS FCST TO PULL VERY COOL AIR SOUTH OUT OF CANADA. THE GFS
ENSEMBLE HOLDS THE HIGH ACROSS MANITOBA AND SASKATCHEWAN WITH A
STATIONARY FRONT DRAPED ACROSS THE CNTL PLAINS. IN FACT THE FCST AREA
REMAINS UNDER SOUTH AND SOUTHEAST WINDS AT 850 MB. NOW THE ALLBLEND
TOTAL QPF FOR THIS PERIOD SHOWS AROUND 1 INCH ACROSS SCNTL NEB TO
LESS THAN 1/4 OF AN INCH ACROSS WRN/NRN NEB SUGGESTING A STATIONARY
FRONT WILL OPERATE ACROSS THE FCST AREA. POPS ARE STILL ISOLATED TO
SCATTERED AND TEMPS ARE A BIT WARMER...UPPER 70S TO LOWER 80S. IT
WOULD APPEAR THAT THE SOUTHERLY WINDS ARE BACKED AROUND THE MANITOBA
HIGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 111 PM CDT SUN AUG 4 2013
MVFR TO IFR CIGS WILL SEE MORE AND LARGER POCKETS OF VFR CIGS AS
CLOUDS ERODE WITH HEATING OF THE AFTERNOON. LAST TO LIFT IS ALONG
THE HIGHER TERRAIN ACROSS WESTERN NEBRASKA. WITH THE DECREASING
CLOUDS AND WARMING TEMPERATURES...AN ISOLATED THUNDERSTORM IS
POSSIBLE...MAINLY ACROSS WESTERN NEBRASKA...HOWEVER ACTIVITY MAY
REMAIN CLOSER TO THE FRONT RANGE.
TONIGHT A RETURN OF THE LOWER MVFR/IFR CIGS IS EXPECTED. LOCALLY
SOME REDUCED VSBY FROM FOG IS ALSO POSSIBLE. A SHORT WAVE WILL
BRING A SLIGHT CHANCE FOR SOME ISOLD TO SCT STORMS. MODELS VARY ON
LOCATION AND WITH THE MAJORITY IMPACTING NORTHERN NEBRASKA...THUS
HAVE INCLUDED VCTS IN THE KVTN TAF...AND WILL LOOK TO UPDATE AND
TIMING BECOMES MORE DEFINED.
BY TOMORROW MORNING THE LOWER CIGS WILL SLOWLY LIFT...WITH A FEW
LINGERING ISOLD STORMS POSSIBLE. PROBABILITY IS TO LOW TO INCLUDE
IN EITHER TAF AT THIS TIME. WINDS THROUGH THE PERIOD WILL
GENERALLY BE SOUTHEASTERLY TO SOUTHERLY.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...MASEK
LONG TERM...CDC
AVIATION....MASEK
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
216 PM MDT SUN AUG 4 2013
.DISCUSSION...
...INCREASED POTENTIAL FOR LOCALLY HEAVY RAINFALL THROUGH TONIGHT...
RADAR TRENDS INDICATING SCATTERED TO NUMEROUS STORMS ACROSS THE HIGH
TERRAIN OF CENTRAL NM. 19Z LAPS ANALYSIS SHOWS A SIGNIFICANT AMOUNT
OF MOIST INSTABILITY OVER THE AREA WITH 2000-3500J/KG CAPE AND LIFTED
INDICES BTWN -3 AND -6C FROM THE RGV INTO THE NE PLAINS. 700-500MB
STORM MOTION VECTORS ARE NORTH NEAR 5 KTS WHICH IS MUCH SLOWER THAN
YESTERDAY...SO THE HEAVY RAINFALL THREAT IS HIGHER AS WELL. PLACED
MENTION OF LCL HEAVY RAIN IN GRIDS BUT WILL NOT ISSUE A FLASH FLOOD
WATCH. OUTFLOW BOUNDARIES WILL ACTIVATE IN THIS REGIME TO PRODUCE
MORE STORMS FOR VALLEY AREAS LATER IN THE DAY AS SHOWN BY THE RUC
AND HRRR GUIDANCE. A LARGE PRECIP SHIELD IS LIKELY TO MOVE SLOWLY
NORTH OVER CENTRAL NM AS WELL TONIGHT. RAISED POPS CONSIDERABLY FOR
THIS REGION.
MONDAY WILL BE AN ACTIVE DAY AGAIN. THE GFS INDICATES PWAT VALUES
WILL TREND DOWN JUST SLIGHTLY AND THE MAIN AXIS OF INSTABILITY WILL
SHIFT A LITTLE EAST ONTO THE HIGH PLAINS. STORM MOTIONS WILL BE MORE
SOUTHWESTERLY AND SLOW AGAIN. THIS WILL BRING A LITTLE MORE COVERAGE
TO THE EASTERN PLAINS DURING THE EVENING. WESTERN NM WILL STILL SEE
VERY WEAK STORM MOTIONS WITH LCL HEAVY RAINFALL. TUESDAY IS EXPECTED
TO BE ACTIVE AS WELL. AN EASTERLY WAVE NOTED ON WATER VAPOR ALONG
THE WEST CENTRAL MEXICAN COAST WILL SHIFT NORTH AND IMPACT EASTERN
AZ/WESTERN NM. RAISED POPS FOR TUESDAY. STEERING FLOW WILL INCREASE
MORE BUT STILL REMAIN LIGHT ENOUGH FOR HEAVY RAINERS.
DRIER MORE STABLE AIR WILL WORK INTO WESTERN/CENTRAL NM BEHIND THE
UPPER WAVE. STORM COVERAGE WILL DIMINISH CONSIDERABLY FOR THE
WEST. THIS UPPER WAVE WILL BECOME CAUGHT UP IN NORTHWEST FLOW OVER
THE CENTRAL PLAINS STATES AND ENHANCE A SURFACE BACK DOOR FRONTAL
BOUNDARY OVER NORTHEAST NM. THE NAM IS BULLISH WITH THE STRENGTH
OF THIS SURFACE BOUNDARY AND THE COVERAGE OF STORMS. OVERALL THE
PATTERN THROUGH THE REMAINDER OF THE WEEK LOOKS TO LOCK IN A VERY
WELL DEFINED MONSOONAL CIRCULATION OVER CENTRAL/WESTERN NM.
GUYER
&&
.FIRE WEATHER...
UPPER HIGH ANCHORED OVER CENTRAL TEXAS WILL SLOWLY SHIFT TOWARD THE
EAST AND SOUTH THROUGH LATE TUESDAY...BECOMING ELONGATED NEAR THE TX
GULF COAST REGION BY WEDNESDAY MORNING. WELL ADVERTISED UPTICK IN
THUNDERSTORM COVERAGE FOR THIS AFTERNOON HAS PANNED OUT WELL WITH
STORM MOTIONS GENERALLY TOWARD THE NORTH-NORTHEAST AT 15 MPH OR
LESS. OUTFLOW BOUNDARY INTERACTIONS IN THE PRESENCE OF A MUCH MORE
UNSTABLE ENVIRONMENT SHOULD RESULT IN QUITE A BIT MORE THUNDERSTORM
ACTIVITY IN THE VALLEYS BY MID TO LATE AFTERNOON AND INTO THE EVENING
AS COMPARED TO SATURDAY...WITH THE POTENTIAL FOR HEAVY THUNDERSTORM
RAINS INCREASING AND EXPANDING ACROSS THE NORTHEAST. THE UPPER FLOW
REGIME WILL FAVOR LATE NIGHT OR NOCTURNAL SHOWERS FOR AREAS BETWEEN
THE CONTINENTAL DIVIDE AND CENTRAL MOUNTAIN CHAIN WITH THE CENTRAL
VALLEY CORRIDOR ESPECIALLY FAVORED.
WELL-ESTABLISHED MONSOON PLUME ALONG THE WESTERN PERIPHERY OF THE
RIDGE WILL CHANGE VERY LITTLE OVER THE NEXT 24-36 HOURS. LINGERING
CLOUD COVER MONDAY MORNING MAY LIMIT EARLY DAYTIME HEATING AND THUS
TOMORROW/S CROP OF THUNDERSTORMS MAY NOT BE QUITE AS WIDESPREAD AS
TODAY BUT THE PATTERN WILL REMAIN FAVORABLE FOR THE WESTERN
TWO-THIRDS OF THE AREA.
TUESDAY WILL MARK A TRANSITION TO A RELATIVELY FASTER SW TO NE
STEERING FLOW...AND POSSIBLY AN ENHANCED WINDOW OF MOISTURE/DYNAMIC
FORCING ASSOCIATED WITH AN EASTERLY WAVE THAT WILL SLOWLY APPROACH
THE REGION IN THE CLOCKWISE FLOW AROUND THE HIGH. WHILE MODELS SHOW
THIS FEATURE TRACKING NORTH-NORTHWEST WELL TO OUR SOUTHWEST...ITS
REMNANTS SHOULD EVENTUALLY WORK BACK TOWARD THE EAST AND THE FOUR
CORNERS. MEDIUM RANGE GUIDANCE SHOWING SOME NICE CONSISTENCY THUS
FAR AND WE WILL SEE IF THE TREND CONTINUES. OVERALL LOW CONFIDENCE IN
WHAT WILL BECOME OF THIS FEATURE...HOW FAR NORTH IT MAY TRACK BUT
THE MODELS ARE GENERALLY IN DECENT AGREEMENT SHOWING THE WAVE
TRANSLATING EASTWARD OVER SOUTHERN COLORADO AND NORTHERN NEW MEXICO
WED-WED PM. AT THE SAME TIME...A GOOD LOOKING BACKDOOR COLD FRONT
IS INDICATED TO SURGE SOUTHWARD SETTING UP A POTENTIALLY VERY ACTIVE
PATTERN FOR AREAS EAST OF THE CENTRAL MOUNTAIN CHAIN AND ESPECIALLY
THE NORTHEAST. EXTENT OF LOWER LEVEL DRYING ACROSS THE WEST REMAINS
A BIG QUESTION MARK...AS MODELS ARE QUITE AGGRESSIVE IN DRYING DEW
POINTS DURING THE WED/THU PERIOD.
KJ
&&
.AVIATION...
18Z TAF CYCLE
CONSIDERABLY MORE ACTIVE THUNDERSTORM CROP FOR WESTERN AND MUCH OF
NORTHERN NEW MEXICO TODAY...AS COMPARED TO 24-HOURS AGO. THIS
INCLUDES THE ABQ-SANTA FE CORRIDOR. STEERING FLOW GENERALLY S-SW
TO N-NE BUT WEAKER THAN YESTERDAY. AS A RESULT...ANY POTENTIAL
TSRA IMPACTS AT KSAF AND KABQ NOT EXPECTED UNTIL MID- AFTERNOON AT
THE EARLIEST. EARLIER IMPACTS AT KGUP AND KLVS AND HAVE INCLUDED
TEMPO GROUP THERE WHERE CONFIDENCE HIGHEST. FLOW REGIME FAVORABLE
FOR AREAS OF SHRA IN THE VICINITY OF KABQ LATE INTO EVENING IF NOT
PAST MIDNIGHT. ELSEWHERE...AIR MASS LEAST UNSTABLE OVER THE
SOUTHEAST PLAINS AND UNFAVORABLE STEERING FLOW WILL PRECLUDE TSRA
AT KROW. ISOLATED CONVECTION OVER EC/NE NM BUT NOT AS ROBUST AS
YESTERDAY. OUTSIDE OF SHOWERS AND THUNDERSTORMS THIS AFTERNOON/
TONIGHT...VFR CONDITIONS EXPECTED TO PREVAIL.
KJ
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 66 92 65 90 / 40 20 20 20
DULCE........................... 55 86 54 83 / 50 40 30 40
CUBA............................ 56 87 55 84 / 60 40 40 30
GALLUP.......................... 59 84 58 84 / 40 30 30 30
EL MORRO........................ 55 78 53 77 / 50 40 30 40
GRANTS.......................... 58 83 57 82 / 60 30 30 30
QUEMADO......................... 57 81 55 80 / 40 50 30 30
GLENWOOD........................ 61 87 60 85 / 30 30 30 20
CHAMA........................... 52 77 51 74 / 60 50 30 40
LOS ALAMOS...................... 61 82 59 80 / 60 40 30 40
PECOS........................... 59 80 58 77 / 60 40 30 40
CERRO/QUESTA.................... 56 79 55 77 / 60 40 30 40
RED RIVER....................... 49 71 48 69 / 60 50 30 50
ANGEL FIRE...................... 48 75 46 73 / 50 40 30 50
TAOS............................ 56 84 54 82 / 60 30 20 40
MORA............................ 55 79 54 77 / 50 40 30 40
ESPANOLA........................ 62 86 61 84 / 60 30 20 30
SANTA FE........................ 61 83 59 80 / 60 30 20 40
SANTA FE AIRPORT................ 62 87 61 83 / 60 30 20 30
ALBUQUERQUE FOOTHILLS........... 66 89 66 86 / 60 20 20 30
ALBUQUERQUE HEIGHTS............. 67 91 68 88 / 60 20 20 20
ALBUQUERQUE VALLEY.............. 65 92 65 90 / 60 20 20 20
ALBUQUERQUE WEST MESA........... 66 93 66 91 / 60 20 20 20
LOS LUNAS....................... 67 90 65 87 / 60 20 20 20
RIO RANCHO...................... 66 93 66 90 / 60 20 20 20
SOCORRO......................... 67 96 66 91 / 40 20 30 20
SANDIA PARK/CEDAR CREST......... 61 86 60 84 / 60 30 30 30
TIJERAS......................... 62 87 61 85 / 60 30 20 30
MORIARTY/ESTANCIA............... 59 87 58 84 / 60 40 30 30
CLINES CORNERS.................. 61 83 60 81 / 50 50 30 40
GRAN QUIVIRA.................... 61 87 60 83 / 40 30 30 40
CARRIZOZO....................... 65 91 64 86 / 30 30 30 30
RUIDOSO......................... 58 82 57 78 / 30 50 30 60
CAPULIN......................... 57 83 58 82 / 50 40 30 40
RATON........................... 59 88 59 87 / 50 30 30 40
SPRINGER........................ 60 88 59 87 / 40 30 30 30
LAS VEGAS....................... 59 83 58 82 / 50 40 30 40
CLAYTON......................... 67 91 67 92 / 30 30 30 30
ROY............................. 64 88 63 88 / 30 40 30 30
CONCHAS......................... 70 95 69 94 / 20 20 20 30
SANTA ROSA...................... 69 93 68 92 / 20 30 20 30
TUCUMCARI....................... 73 99 72 98 / 10 10 20 20
CLOVIS.......................... 69 95 68 95 / 5 5 10 10
PORTALES........................ 69 95 68 96 / 5 5 10 10
FORT SUMNER..................... 71 95 71 94 / 10 10 20 20
ROSWELL......................... 72 98 72 97 / 5 5 10 20
PICACHO......................... 64 90 66 89 / 20 20 20 30
ELK............................. 61 83 61 82 / 20 30 30 30
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1136 AM MDT SUN AUG 4 2013
.AVIATION...
18Z TAF CYCLE
CONSIDERABLY MORE ACTIVE THUNDERSTORM CROP FOR WESTERN AND MUCH OF
NORTHERN NEW MEXICO TODAY...AS COMPARED TO 24-HOURS AGO. THIS
INCLUDES THE ABQ-SANTA FE CORRIDOR. STEERING FLOW GENERALLY S-SW
TO N-NE BUT WEAKER THAN YESTERDAY. AS A RESULT...ANY POTENTIAL
TSRA IMPACTS AT KSAF AND KABQ NOT EXPECTED UNTIL MID- AFTERNOON AT
THE EARLIEST. EARLIER IMPACTS AT KGUP AND KLVS AND HAVE INCLUDED
TEMPO GROUP THERE WHERE CONFIDENCE HIGHEST. FLOW REGIME FAVORABLE
FOR AREAS OF SHRA IN THE VICINITY OF KABQ LATE INTO EVENING IF NOT
PAST MIDNIGHT. ELSEWHERE...AIR MASS LEAST UNSTABLE OVER THE
SOUTHEAST PLAINS AND UNFAVORABLE STEERING FLOW WILL PRECLUDE TSRA
AT KROW. ISOLATED CONVECTION OVER EC/NE NM BUT NOT AS ROBUST AS
YESTERDAY. OUTSIDE OF SHOWERS AND THUNDERSTORMS THIS
AFTERNOON/TONIGHT...VFR CONDITIONS EXPECTED TO PREVAIL. KJ
&&
.PREV DISCUSSION...1054 AM MDT SUN AUG 4 2013...
16Z LAPS ANALYSIS AND RADAR TRENDS SHOW A LOT MORE ACTIVITY SO FAR
THIS MORNING THAN SATURDAY. STORM MOTIONS WILL TRACK NORTH BTWN 5
AND 10 MPH SO ADDED LOCALLY HEAVY WORDING TO ZONES. A WELL DEFINED
AREA OF MID LEVEL CLOUDINESS AND INSTABILITY MOVING NORTH INTO THE
WESTERN HALF OF LINCOLN AND EASTERN SOCORRO COUNTIES IS SHOWN BY
THE RUC AND HRRR TO EXPAND STORM COVERAGE THIS AFTERNOON. INCREASED
POPS TO HIGH CHANCE/LIKELY FOR MUCH OF THE CENTRAL MOUNTAIN CHAIN
EASTWARD ALONG THE EAST SLOPES. ALSO RAISED CHANCES FOR ABQ METRO
AREA GIVEN CONVECTION ALREADY DEVELOPING TO OUR SOUTH.
GUYER
.PREV DISCUSSION...324 AM MDT SUN AUG 4 2013...
SUBSIDENCE INVERSION JUST ABOVE 700MB PROGGED TO GRADUALLY DISSIPATE
EARLY THIS MORNING AS OUTFLOWS FROM STORMS OVER NE NM CONTINUES TO
PUSH SOUTHWESTWARD THROUGH THE CANYONS OF THE CENTRAL MTNS...USHERING
IN SLIGHTLY COOLER MID LEVEL AIR. NAMBUFR DATA ALSO PROGGING A
MUCH BETTER INSTABILITY PROFILE FOR THIS AFTERNOON AS SURFACE
TEMPERATURES WARM TO A DEGREE OR TWO ABOVE SATURDAY HIGHS AND 500MB
TEMPS COOL BY ABOUT 1.5C. SCATTERED THUNDERSTORMS WILL DEVELOP OVER
THE WESTERN AND NORTHERN MOUNTAINS DURING THE LATE MORNING/EARLY
AFTERNOON...THEN MOVE TO THE NORTHEAST BTWN 10-20MPH OVER THE
CENTRAL AND WEST-CENTRAL PORTIONS OF THE STATE. STORMS WILL MOVE
EASTWARD BTWN 5-10 MPH OVER THE NORTH AS THE FLOW ALOFT CURLS
CLOCKWISE AROUND THE UPPER HIGH CENTER OVER WEST TX.
AS THE UPPER HIGH CENTER INCHES EASTWARD MONDAY...500MB TEMPERATURES
COOL ANOTHER DEGREE C OR SO...MAKING FOR A SLIGHTLY MORE UNSTABLE
AIRMASS. ELY WAVE IS FORECAST BY ALL NWP MODELS TO ROUND THE BASE
OF THE UPPER HIGH AND HEAD NORTHWARD INTO AZ TUESDAY FORENOON.
DEEP SUBTROPICAL MOISTURE GETS PULLED UP IN THE SLY FLOW AHEAD OF
THE WAVE OVER NM TUESDAY AFTERNOON. BOTH NAM AND GFS DEEPEN THE
WAVE OVER SE COLORADO TUESDAY NIGHT...CLOSING IT OFF NEAR THE FOUR
CORNERS WEDNESDAY. THIS FEATURE SHOULD ACT TO HELP GET SCATTERED
TO NUMEROUS STORMS TO FIRE OVER CENTRAL AND NORTHERN NM WEDNESDAY
AS COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW GRADUALLY INVADE
THE AREA FROM THE NORTHWEST.
UPPER LEVEL RIDGE PUMPS UP RAPIDLY OVER THE REGION THURSDAY...MAKING
FOR A DOWN DAY FOR CONVECTIVE ACTIVITY FORECAST AREA-WIDE. BOTH
GFS AND ECMWF BRING BACK THE MONSOONAL PLUME IN A HURRY THURSDAY
NIGHT AND CONTINUE IT THROUGH NEXT WEEKEND.
33
.FIRE WEATHER...
WETTING RAINS WILL FAVOR WESTERN PORTIONS OF THE FORECAST AREA TODAY
UNDER THE EASTERN-MOST EXTENT OF THE MONSOONAL MOISTURE PLUME. THE
SANGRE DE CRISTO MOUNTAINS...NORTHEAST HIGHLANDS AND NORTHEAST
PLAINS WILL LIKELY BENEFIT FROM WETTING RAINS AS WELL. TEMPERATURES
WILL GENERALLY BE NEAR NORMAL WEST AND ABOVE NORMAL EAST. VENT RATES
ARE FORECAST TO BE FAIR TO POOR CENTRAL AND WEST...BUT HIGHLY
DEPENDENT ON CLOUDS AND POTENTIAL RAIN-COOLING LIMITING SURFACE
HEATING.
MORE OF THE SAME ON MONDAY AS THE UPPER HIGH CENTER REMAINS TO THE
EAST OVER CENTRAL TEXAS. TUESDAY WILL BE A TRANSITION DAY AS
PRESSURE HEIGHTS DECREASE WITH AN EASTERLY WAVE MOVING AROUND THE
UPPER HIGH CIRCULATION OVER ARIZONA AND INTO THE FOUR CORNERS AREA.
THIS WILL HELP TO DESTABILIZE THE ATMOSPHERE AND SHOULD LEAD TO AN
UPTICK IN WETTING RAINS FOR MUCH OF THE AREA. A BACKDOOR FRONT WILL
GET INTO THE MIX TUESDAY NIGHT THROUGH WEDNESDAY ACROSS THE EASTERN
PLAINS AND COMBINE WITH THE EASTERLY WAVE TO BRING WETTING RAINS TO
MUCH OF THE EAST...ESPECIALLY NORTHEAST. TEMPERATURES WILL TREND
DOWN DURING THIS PERIOD ACROSS THE EAST AND HUMIDITIES WILL TREND
UP. A MORE TRADITIONAL MONSOON SYNOPTIC WEATHER PATTERN LOOKS TO
DEVELOP BY THE END OF THE WORK WEEK...WITH THE UPPER HIGH NEAR THE
ARKLATEX AND A WEST COAST TROUGH ALLOWING FOR DEEP SOUTHERLIES
ACROSS NEW MEXICO. NO END IN SIGHT TO DAILY ROUNDS OF WETTING
SHOWERS AND STORMS.
11
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1054 AM MDT SUN AUG 4 2013
.UPDATE...
16Z LAPS ANALYSIS AND RADAR TRENDS SHOW A LOT MORE ACTIVITY SO FAR
THIS MORNING THAN SATURDAY. STORM MOTIONS WILL TRACK NORTH BTWN 5
AND 10 MPH SO ADDED LOCALLY HEAVY WORDING TO ZONES. A WELL DEFINED
AREA OF MID LEVEL CLOUDINESS AND INSTABILITY MOVING NORTH INTO THE
WESTERN HALF OF LINCOLN AND EASTERN SOCORRO COUNTIES IS SHOWN BY
THE RUC AND HRRR TO EXPAND STORM COVERAGE THIS AFTERNOON. INCREASED
POPS TO HIGH CHANCE/LIKELY FOR MUCH OF THE CENTRAL MOUNTAIN CHAIN
EASTWARD ALONG THE EAST SLOPES. ALSO RAISED CHANCES FOR ABQ METRO
AREA GIVEN CONVECTION ALREADY DEVELOPING TO OUR SOUTH.
GUYER
&&
.PREV DISCUSSION...532 AM MDT SUN AUG 4 2013...
.AVIATION...
12Z TAF CYCLE
SHORT-LIVED MVFR CIGS MAY DEVELOP AT KLVS EARLY THIS MORNING...
OTHERWISE VFR CONDITIONS TO PREVAIL AT TERMINALS OUTSIDE OF
SCATTERED SHOWERS AND THUNDERSTORMS THIS AFTERNOON/EVENING.
MVFR...AND EVEN SHORT-LIVED IFR CONDITIONS LIKELY IN/NEAR STORMS
TODAY. TERMINALS MOST LIKELY TO BE IMPACTED BY TSRA TODAY INCLUDE
KGUP...KSAF AND KLVS.
11
.PREV DISCUSSION...324 AM MDT SUN AUG 4 2013...
SUBSIDENCE INVERSION JUST ABOVE 700MB PROGGED TO GRADUALLY DISSIPATE
EARLY THIS MORNING AS OUTFLOWS FROM STORMS OVER NE NM CONTINUES TO
PUSH SOUTHWESTWARD THROUGH THE CANYONS OF THE CENTRAL MTNS...USHERING
IN SLIGHTLY COOLER MID LEVEL AIR. NAMBUFR DATA ALSO PROGGING A
MUCH BETTER INSTABILITY PROFILE FOR THIS AFTERNOON AS SURFACE
TEMPERATURES WARM TO A DEGREE OR TWO ABOVE SATURDAY HIGHS AND 500MB
TEMPS COOL BY ABOUT 1.5C. SCATTERED THUNDERSTORMS WILL DEVELOP OVER
THE WESTERN AND NORTHERN MOUNTAINS DURING THE LATE MORNING/EARLY
AFTERNOON...THEN MOVE TO THE NORTHEAST BTWN 10-20MPH OVER THE
CENTRAL AND WEST-CENTRAL PORTIONS OF THE STATE. STORMS WILL MOVE
EASTWARD BTWN 5-10 MPH OVER THE NORTH AS THE FLOW ALOFT CURLS
CLOCKWISE AROUND THE UPPER HIGH CENTER OVER WEST TX.
AS THE UPPER HIGH CENTER INCHES EASTWARD MONDAY...500MB TEMPERATURES
COOL ANOTHER DEGREE C OR SO...MAKING FOR A SLIGHTLY MORE UNSTABLE
AIRMASS. ELY WAVE IS FORECAST BY ALL NWP MODELS TO ROUND THE BASE
OF THE UPPER HIGH AND HEAD NORTHWARD INTO AZ TUESDAY FORENOON.
DEEP SUBTROPICAL MOISTURE GETS PULLED UP IN THE SLY FLOW AHEAD OF
THE WAVE OVER NM TUESDAY AFTERNOON. BOTH NAM AND GFS DEEPEN THE
WAVE OVER SE COLORADO TUESDAY NIGHT...CLOSING IT OFF NEAR THE FOUR
CORNERS WEDNESDAY. THIS FEATURE SHOULD ACT TO HELP GET SCATTERED
TO NUMEROUS STORMS TO FIRE OVER CENTRAL AND NORTHERN NM WEDNESDAY
AS COLDER AIR ALOFT ASSOCIATED WITH THE UPPER LOW GRADUALLY INVADE
THE AREA FROM THE NORTHWEST.
UPPER LEVEL RIDGE PUMPS UP RAPIDLY OVER THE REGION THURSDAY...MAKING
FOR A DOWN DAY FOR CONVECTIVE ACTIVITY FORECAST AREA-WIDE. BOTH
GFS AND ECMWF BRING BACK THE MONSOONAL PLUME IN A HURRY THURSDAY
NIGHT AND CONTINUE IT THROUGH NEXT WEEKEND.
33
.FIRE WEATHER...
WETTING RAINS WILL FAVOR WESTERN PORTIONS OF THE FORECAST AREA TODAY
UNDER THE EASTERN-MOST EXTENT OF THE MONSOONAL MOISTURE PLUME. THE
SANGRE DE CRISTO MOUNTAINS...NORTHEAST HIGHLANDS AND NORTHEAST
PLAINS WILL LIKELY BENEFIT FROM WETTING RAINS AS WELL. TEMPERATURES
WILL GENERALLY BE NEAR NORMAL WEST AND ABOVE NORMAL EAST. VENT RATES
ARE FORECAST TO BE FAIR TO POOR CENTRAL AND WEST...BUT HIGHLY
DEPENDENT ON CLOUDS AND POTENTIAL RAIN-COOLING LIMITING SURFACE
HEATING.
MORE OF THE SAME ON MONDAY AS THE UPPER HIGH CENTER REMAINS TO THE
EAST OVER CENTRAL TEXAS. TUESDAY WILL BE A TRANSITION DAY AS
PRESSURE HEIGHTS DECREASE WITH AN EASTERLY WAVE MOVING AROUND THE
UPPER HIGH CIRCULATION OVER ARIZONA AND INTO THE FOUR CORNERS AREA.
THIS WILL HELP TO DESTABILIZE THE ATMOSPHERE AND SHOULD LEAD TO AN
UPTICK IN WETTING RAINS FOR MUCH OF THE AREA. A BACKDOOR FRONT WILL
GET INTO THE MIX TUESDAY NIGHT THROUGH WEDNESDAY ACROSS THE EASTERN
PLAINS AND COMBINE WITH THE EASTERLY WAVE TO BRING WETTING RAINS TO
MUCH OF THE EAST...ESPECIALLY NORTHEAST. TEMPERATURES WILL TREND
DOWN DURING THIS PERIOD ACROSS THE EAST AND HUMIDITIES WILL TREND
UP. A MORE TRADITIONAL MONSOON SYNOPTIC WEATHER PATTERN LOOKS TO
DEVELOP BY THE END OF THE WORK WEEK...WITH THE UPPER HIGH NEAR THE
ARKLATEX AND A WEST COAST TROUGH ALLOWING FOR DEEP SOUTHERLIES
ACROSS NEW MEXICO. NO END IN SIGHT TO DAILY ROUNDS OF WETTING
SHOWERS AND STORMS.
11
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
203 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER NORTHWEST FLOW WILL DEVELOP TODAY...ALONG WITH SCATTERED
LIGHT SHOWERS THROUGH EARLY AFTERNOON...MAINLY OVER CENTRAL NEW
YORK. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN TONIGHT THROUGH
MONDAY...WITH MAINLY CLEAR SKIES. VERY COOL TEMPERATURES
OVERNIGHT...WILL MODERATE BACK INTO THE 70S MONDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM...LAKE EFFECT CLDS ARE NOW WELL ENTRENCHED IN THE AREA THIS
MRNG. NAM TRIES TO DRY US OUT LTR IN THE AFTN WHILE THE HRRR KEEPS
THE CLDS AND SPRINKLES THRU THE DAY. LEAN TWRDS THE HRRR SOLN AS
IT/S NEVER SMART TO UNDERESTIMATE THE ABILITY OF UPSTATE NY TO
GENERATE CLDS IN A COOL NW FLOW. HAVE LWRD AFTN HI/S A BIT AND
INCRSD CLDS AND PCPN CHANCE.
415 AM UPDATE... WATER VAPOR IMAGERY SHOWS AN UPR LVL TROUGH IN
THE PROCESS OF DEEPENING ACRS THE UPR LKS RGN...SERN CANADA...AND
THE NERN CONUS THIS MRNG. AS THIS EVOLUTION CONTS TDY...A NWLY
FLOW REGIME AND LOW-LVL CAA WILL PREVAIL. THE LATEST MESO`S
ALREADY SHOW 850 MB TEMPS DOWN TO ABT 7C OVER LK ONT...WITH
READINGS PROGGED TO DROP TO 5-6C BY ARND 18Z. GIVEN LK ONT WATER
TEMPS OF 22-24C...ALG WITH THE PRESENCE OF LOW-LVL MOISTURE
TRAPPED UNDER A SUBSIDENCE INVERSION ALOFT...SCTD LK EFF -SHRA
WILL PREVAIL THROUGH MIDDAY-EARLY AFTN. A 290-300 VECTOR FAVORS A
CORRIDOR THROUGH ONONDAGA/SRN CAYUGA/NRN CORTLAND/ONEIDA/MADISON/CHENANGO/
OTSEGO/NRN DELAWARE CNTYS. THESE SHWRS SHOULD DIMINISH BY
18-21Z...AS THE COLUMN BEGINS TO DRY OUT BY THIS TIME.
FARTHER S AND W...ACRS THE TWIN TIERS...THE WYO/LACK VLYS...AND
THE POCONOS...PTLY TO MOSTLY SUNNY SKIES WILL PREVAIL.
AS ALLUDED TO ABV...MAX TEMPS WILL BE COOLER TDY (HIGHS RANGING
FROM THE UPR 60S-MID 70S).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
430 AM UPDATE... GENERALLY QUIET WX FORESEEN THIS PD...AS RIDGING
BOTH SFC AND ALOFT BUILD IN TNT-MON...GRADUALLY MOVING OFF THE
COAST ON TUE.
THE COMBO OF CLEARING SKIES AND A COOL AMS WILL LEAD TO MIN TEMPS
DOWN TO THE MID 40S IN NORMALLY CHILLIER VLYS LTR TNT/EARLY MON...WITH
PATCHY VLY FOG PSBL ACRS THE TWIN TIERS. AS THE AMS MODIFIES DURG
THE DAY MON...PLENTY OF SUNSHINE SHOULD HELP AFTN TEMPS RECOVER
INTO THE 70S (2-4 DEGS HIGHER THAN ON SUN MOST AREAS).
BY TUE...A RETURN SRLY FLOW DVLPS...LEADING TO WARM AND MOIST
ADVECTION. WE MAY SEE A FEW -SHRA DVLP...BUT MOST OF THESE WILL
LIKELY RESIDE ACRS OUR WRN/SRN ZNS...CLOSER TO PASSING S/WV
ENERGY...AND ALSO AN APPROACHING WARM FRNTL BNDRY. FOR NOW...WE`LL
SIMPLY CALL FOR ISOLD-SCTD SHWRS THESE AREAS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
GDNC COMING INTO BETTER AGREEMENT WITH MID TO LATE WEEK FROPA
ASSCD WITH S/WV ROTATING ARND A CLOSED LOW OVER CNTRL CANADA. SOME
QUESTION ON THE XTNT OF SRN STREAM INFLUENCES ON THIS SYSTEM.
OVERALL...XPCT CDFNT TO PASS MOST OF THE RGN ON THU...ALTHO SOME
LINGERING PCPN PSBL FAR SE ZONES ON FRI CLOSER TO THE RETREATING FNTL
BNDRY. OTRW...HIGH PRES BUILDS INTO THE AREA LATE WEEK INTO NXT
WEEKEND. 2NDRY CDFNT HINTED AT FOR NXT WEEKEND (SAT) BUT IT LOOKS
FAIRLY DRY AT THIS POINT. SO AFTER THURSDAY`S FROPA...GNRLY DRY WX
AND TEMPS AVERAGING NEAR OR A FEW DEG BLO NORMAL. WPC GUIDANCE
LOOKED GOOD AND UTILIZED WITH LTL MODIFICATION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
2 PM EDT UPDATE... GENERALLY VFR WITH AN AREA OF SCATTERED
SHOWERS WITH MVFR CIGS 020-030 AND VSBY GENERALLY 5SM IN -SHRA IS
MOVING ACROSS THE CATSKILLS..SOUTHERN TIER OF NY AND NORTHERN TIER
OF PA AT 18Z. THIS AREA WILL CONTINUE MOVING SOUTHEAST WITH
CLEARING BEHIND IT JUST LEAVING SOME SCATTER VFR STRATOCU 030-050
BASES WHICH WILL DISSIPATE FURTHER WITH SUNSET.
WINDS ARE FROM THE NW AT 10-15KT WITH SOME GUSTS 20KT. WINDS WILL
ALSO SETTLE DOWN NEAR SUNSET. STRONG RADIATIONAL COOLING TONIGHT
WILL LEAD TO LIGHT WINDS IN THE VALLEYS AND IFR FOG OVER THE
RIVERS AND LAKES FROM 09 TO 12Z. EXPECTING FOG TO BE SHALLOW AND
JUST LAST A FEW HOURS DUE TO BOUNDARY LAYER WINDS AND DRY AIR
MOVING DOWN FROM THE NORTHWEST.
MONDAY WILL BE VFR WITH FEW CLOUDS.
OUTLOOK...
MON NIGHT...VFR. LOCAL IFR VALLEY FOG.
TUE...GENERALLY VFR. CHC MVFR SHWRS.
TUE NIGHT - WED NIGHT...MVFR CIGS SHWRS/TSRA.
THU...MVFR IN SHRA AND TSRA IMPROVING TO VFR LATE.
FRI...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...DGM/MLJ
LONG TERM...
AVIATION...BMW
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
135 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A DEEP TROUGH OF LOW PRESSURE CONTINUES ACROSS OUR REGION TODAY WITH
ADDITIONAL SHOWERS WITH EMBEDDED THUNDERSTORMS POSSIBLE.
TEMPERATURES WILL BE 5 TO 10 DEGREES BELOW NORMAL WITH HIGHS MAINLY
IN THE 60S TO NEAR 70. HIGH PRESSURE LOCATED OVER THE CENTRAL GREAT
LAKES WILL SHIFT INTO THE REGION ON MONDAY...WITH CLEARING SKIES AND
COOL TEMPERATURES. A WARMING TREND IS EXPECTED BY THE MIDDLE OF THIS
UPCOMING WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1030 AM EDT SUNDAY...FORECAST APPEARS ON TRACK AND JUST SOME
MINOR EDITS NECESSARY. SCATTERED SHOWERS BEGINNING TO APPEAR AS
SHORT WAVE TROF SWINGS THROUGH. BEST CHANCE FOR SHOWERS WILL BE
NORTHERN VERMONT...THOUGH MOST AREAS WILL SEE SOME SCATTERED
ACTIVITY. BEST CHANCE FOR A T-STORM WILL BE CENTRAL/SOUTHERN
VERMONT TODAY WHERE SUNSHINE APPEARED THIS MORNING AND BEST
INSTABILITY EXISTS. INCREASED TEMPS SLIGHTLY ACROSS THE SOUTHERN
VERMONT TO ACCOUNT FOR ADDITIONAL SUNSHINE...OTHERWISE MINOR
CHANGES.
ONCE AGAIN FCST FOCUS WL BE AREAL COVERAGE/INTENSITY OF
SHOWERS/STORMS TODAY. WATER VAPOR SHOWS DEEP MID/UPPER LVL TROF
ACRS THE NE CONUS...WITH TWO ADDITIONAL S/W`S EXPECTED TO IMPACT
OUR CWA TODAY. FIRST S/W IS LOCATED OVER JUST NORTH OF THE EASTERN
GREAT LAKES...AND WL BE ACRS OUR WESTERN ZNS BTWN 12-15Z
TODAY...MEANWHILE STRONG ENERGY BTWN HUDSON BAY AND NORTHERN GREAT
LAKES WL APPROACH OUR CWA BY 18Z TODAY. THIS PIECE OF ENERGY
DIVING ALONG THE SOUTHERN PERIPHERY OF TROF WL HELP DEVELOP A
CLOSED 5H/7H CIRCULATION OVER SOUTHERN CANADA BY 00Z MONDAY. THIS
CYCLONIC UPSLOPE FLW...ALONG WITH LLVL CAA...AND LEFTOVER 1000 TO
700 MOISTURE WL HELP IN THE DEVELOPMENT OF ADDITIONAL UPSLOPE
SHOWERS THIS EVENING. FOR TODAY...WL CONT TO MENTION LIKELY POPS
WITH GREATEST CHCS ACRS THE NORTHERN/CENTRAL ZNS...WHERE 850 TO
500MB RH IS THE DEEPEST. IN ADDITION...BEST PVA ASSOCIATED WITH 5H
VORT AND NOSE OF 25H JET IS ACRS THIS REGION. LATEST RAP SOUNDINGS
CONT TO SUPPORT SOME SFC HEATING RESULTING IN CAPE VALUES BTWN 800
AND 1200 J/KG...AND LIS AROUND -2C...FROM DEVELOPING COLD POOL
ALOFT. THIS INSTABILITY SHOULD PROMOTE STRONG ENOUGH UPDRAFTS TO
SUPPORT MENTION OF THUNDER...ESPECIALLY MTNS AND NORTHERN CWA. THE
COMBINATION OF LOW WET BULB ZERO HEIGHTS ASSOCIATED WITH COLD
THERMAL PROFILES...SOME SMALL HAIL WL BE POSSIBLE...IN ADDITION TO
LOCALIZED WIND GUSTS TO 30 MPH. THE LACK OF INSTABILITY WL KEEP
STORMS BLW SVR LIMITS THIS AFTN AND LIMITED DEEP MOISTURE WL LIMIT
AREAL COVERAGE. WL MENTION CHCS IN HWO...BUT NOT ZONES ATTM. CWMW
SOUNDING SHOWS 1000 TO 850MB TEMPS BTWN 1 AND 3C COOLER THAN 24HR
AGO...SUPPORTING HIGHS ONLY IN THE 60S MTNS TO NEAR 70F VALLEYS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
AS OF 415 AM EDT SUNDAY...LARGE SCALE SYNOPTIC FORCING FROM
POTENT 5H VORT WL TRANSITION TO MESOSCALE UPSLOPE LIFT AS CYCLONIC
NW FLW CONTS ACRS OUR REGION TONIGHT. EXPECT AREAL COVERAGE/INTENSITY OF
PRECIP TO QUICKLY DISSIPATE BY 00Z THIS EVENING...WITH
PRECIP CONFINED ALONG THE UPSLOPE REGIONS OF THE NORTHERN DACKS AND
CENTRAL/GREEN MTNS. UPSLOPE PROCEDURE SHOWS GOOD 1000 TO 700MB
RH...FAVORABLE SFC TO 700MB FLW OF 20 TO 30 KNOTS...AND ASSOCIATED
ENHANCED UVVS ACRS THE WESTERN SLOPES. WL MENTION LIKELY POPS THRU
03Z ACRS THE MTNS...WITH SCHC/CHC POPS ELSEWHERE...AFT 03Z DEEP
LAYER MOISTURE QUICKLY DECREASES AS SUBSIDENCE DEVELOPS. THIS WL
RESULT IN CLRING SKIES IN MOST LOCATIONS BY MORNING...EXCEPT
NORTHERN VT. LLVL CAA RESULTS IN PROGGED 85H TEMPS BTWN 2-4C BY
12Z MONDAY...WITH GOOD BL MIXING. THIS WL SUPPORT ADVECTION TYPE
COOLING WITH LOWS RANGING FROM THE U30S SLK TO NEAR 50F CPV. IF
WINDS DECOUPLE AT SLK...COULD SEE TEMPS DROP INTO THE MID 30S BY
12Z MONDAY.
MONDAY AND TUESDAY...SFC HIGH PRES BUILDING ACRS OUR CWA WL RESULT
IN DRY CONDITIONS AND BLW NORMAL TEMPS. THERMAL SOUNDINGS SUGGEST
MORE OF A FALL LIKE TEMP PROFILE ON MONDAY. PROGGED 85H TEMPS BTWN
4-6C...WITH MOSTLY SUNNY SKIES SUPPORT HIGHS 60S TO NEAR 70 MOST
LOCATIONS. A CHILLY NIGHT IS EXPECTED ON MONDAY NIGHT/TUES MORNING
WITH LOWS RANGING FROM M30S SLK/LAKE PLACID/NEK TO M/U 40S CPV...AND
MID 50S NEAR THE LAKE. TUESDAY...WEAK LLVL WAA DEVELOPS WITH MAINLY
CLR SKIES AND TEMPS IN THE 70S. INTERESTING TO SEE THE GOOD MIXING
ON MONDAY AFTN...AND HOW THE SFC DWPTS DROP INTO THE M/U 30S...VERY
DRY AIR IS PROGGED TO MIX DOWN....RESULTING IN LOW RH VALUES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 415 AM EDT SUNDAY...LARGE UPPER TROUGH TAKES SHAPE OVER CENTRAL
CANADA AND THE UPPER MIDWEST TUESDAY NIGHT INTO WEDNESDAY
MORNING. THIS WILL HELP TO BACK THE UPPER FLOW TO THE WEST AND
SOUTHWEST ON WEDNESDAY. THIS WILL ALLOW 850/925 MILLIBAR
TEMPERATURES TO RISE AND LOOKING AT HIGH TEMPERATURES RIGHT AROUND
SEASONAL NORMALS WEDNESDAY. CLOUDS WILL ALSO BE ON THE INCREASE
AND THERE COULD BE SOME AFTERNOON THUNDERSTORMS...BUT IT APPEARS
BEST DYNAMIC SUPPORT/SURFACE COLD FRONT DO NOT MOVE INTO THE AREA
UNTIL WEDNESDAY NIGHT AND THURSDAY. GOING FORECAST HAS THIS IDEA
COVERED WELL AND HAVE CONTINUED THIS THINKING IN THE GRIDS.
FORCING/COLD FRONT MOVE EAST OF THE AREA THURSDAY NIGHT FOR A
DRYING TREND AND PRONOUNCED WESTERLY FLOW ALOFT DEVELOPS OVER THE
AREA ON FRIDAY. LOW LEVEL THERMAL PROFILE SHOWS WARMEST READINGS
OF THE WEEK MOVE INTO THE AREA ON FRIDAY. THIS WILL PRODUCE HIGH
TEMPERATURES AT OR SLIGHTLY ABOVE SEASONAL NORMALS. AN UPPER LEVEL
DISTURBANCE WILL APPROACH THE AREA LATER ON SATURDAY... BUT BEST
FORCING LOOKS TO STAY UP IN CANADA...THUS GOING FORECAST OF A
SLIGHT CHANCE OF SHOWERS LOOKS GOOD.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THROUGH 18Z MONDAY...SCT-BKN VFR CLOUDS WILL PERSIST THROUGH THE
REMAINDER OF THE DAYLIGHT HOURS AND INTO THE EARLY EVENING ALONG
WITH SCATTERED RAIN SHOWERS WITH POSSIBLY A FEW LIGHTNING STRIKES
AND SOME SMALL HAIL. SKIES TREND TOWARDS CLEAR AFTER 02Z AS HIGH
PRESSURE BUILDS INTO THE AREA...WITH GUSTY WEST/NORTHWEST WINDS
ABATING. CLEARING SKIES OVERNIGHT COULD LEAD TO SOME FOG DEVELOPMENT
AFTER 05Z...ESPECIALLY AT KSLK BUT BOUNDARY LAYER WINDS MAY STAY
STRONG ENOUGH TO INHIBIT IT. NOT OVERLY CONFIDENT AT THIS TIME SO
HAVE OFFERED SOME 3SM BR FOR NOW AND WILL ALLOW THE NEXT SHIFT TO
REASSESS. AFTER 12Z MONDAY...CLEAR SKIES WILL GIVE WAY TO FEW-SCT
FAIR WEATHER CLOUDS...WITH CONDITIONS REMAINING VFR ALONG WITH NW
WINDS OF 5-10 KNOTS.
OUTLOOK 18Z MONDAY THROUGH FRIDAY...
18Z MONDAY THROUGH 12Z WEDNESDAY...VFR UNDER SURFACE HIGH PRESSURE.
12Z WEDNESDAY THROUGH 00Z THURSDAY...MAINLY VFR WITH A CHANCE FOR
SOME ISOLATED/SCATTERED SHOWERS AS A WARM FRONT APPROACHES.
00Z THURSDAY THROUGH 00Z FRIDAY...VFR TRENDING TO MVFR/IFR IN
SHOWERS AND STORMS AS A WARM FRONT LIFTS ACROSS THE NORTHEAST.
00Z FRIDAY THROUGH 00Z SATURDAY...VFR UNDER SURFACE HIGH PRESSURE.
&&
.EQUIPMENT...
AS OF 1225 PM EDT SATURDAY...NOAA WEATHER RADIO WXM 44...
BROADCASTING FROM THE TOP OF MOUNT ASCUTNEY VERMONT...REMAINS OFF
THE AIR UNTIL FURTHER NOTICE DUE TO A DAMAGED ANTENNA.
KTYX RADAR HAS RETURNED TO SERVICE. HOWEVER...TECHNICIANS HAVE
DETERMINED THAT ADDITIONAL WORK IS NEEDED AT THE SITE. PARTS ARE
ON ORDER...WITH ADDITIONAL DOWNTIME EXPECTED AS EARLY AS NEXT
WEEK.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...NONE.
&&
$$
SYNOPSIS...TABER
NEAR TERM...TABER/NF
SHORT TERM...TABER
LONG TERM...EVENSON
AVIATION...LAHIFF
EQUIPMENT...WFO BTV
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
105 PM EDT SUN AUG 4 2013
.SYNOPSIS...
A COOLER NORTHWEST FLOW WILL DEVELOP TODAY...ALONG WITH SCATTERED
LIGHT SHOWERS THROUGH EARLY AFTERNOON...MAINLY OVER CENTRAL NEW
YORK. A HIGH PRESSURE SYSTEM WILL THEN BUILD IN TONIGHT THROUGH
MONDAY...WITH MAINLY CLEAR SKIES. VERY COOL TEMPERATURES
OVERNIGHT...WILL MODERATE BACK INTO THE 70S MONDAY AFTERNOON.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
930 AM...LAKE EFFECT CLDS ARE NOW WELL ENTRENCHED IN THE AREA THIS
MRNG. NAM TRIES TO DRY US OUT LTR IN THE AFTN WHILE THE HRRR KEEPS
THE CLDS AND SPRINKLES THRU THE DAY. LEAN TWRDS THE HRRR SOLN AS
IT/S NEVER SMART TO UNDERESTIMATE THE ABILITY OF UPSTATE NY TO
GENERATE CLDS IN A COOL NW FLOW. HAVE LWRD AFTN HI/S A BIT AND
INCRSD CLDS AND PCPN CHANCE.
415 AM UPDATE... WATER VAPOR IMAGERY SHOWS AN UPR LVL TROUGH IN
THE PROCESS OF DEEPENING ACRS THE UPR LKS RGN...SERN CANADA...AND
THE NERN CONUS THIS MRNG. AS THIS EVOLUTION CONTS TDY...A NWLY
FLOW REGIME AND LOW-LVL CAA WILL PREVAIL. THE LATEST MESO`S
ALREADY SHOW 850 MB TEMPS DOWN TO ABT 7C OVER LK ONT...WITH
READINGS PROGGED TO DROP TO 5-6C BY ARND 18Z. GIVEN LK ONT WATER
TEMPS OF 22-24C...ALG WITH THE PRESENCE OF LOW-LVL MOISTURE
TRAPPED UNDER A SUBSIDENCE INVERSION ALOFT...SCTD LK EFF -SHRA
WILL PREVAIL THROUGH MIDDAY-EARLY AFTN. A 290-300 VECTOR FAVORS A
CORRIDOR THROUGH ONONDAGA/SRN CAYUGA/NRN CORTLAND/ONEIDA/MADISON/CHENANGO/
OTSEGO/NRN DELAWARE CNTYS. THESE SHWRS SHOULD DIMINISH BY
18-21Z...AS THE COLUMN BEGINS TO DRY OUT BY THIS TIME.
FARTHER S AND W...ACRS THE TWIN TIERS...THE WYO/LACK VLYS...AND
THE POCONOS...PTLY TO MOSTLY SUNNY SKIES WILL PREVAIL.
AS ALLUDED TO ABV...MAX TEMPS WILL BE COOLER TDY (HIGHS RANGING
FROM THE UPR 60S-MID 70S).
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
430 AM UPDATE... GENERALLY QUIET WX FORESEEN THIS PD...AS RIDGING
BOTH SFC AND ALOFT BUILD IN TNT-MON...GRADUALLY MOVING OFF THE
COAST ON TUE.
THE COMBO OF CLEARING SKIES AND A COOL AMS WILL LEAD TO MIN TEMPS
DOWN TO THE MID 40S IN NORMALLY CHILLIER VLYS LTR TNT/EARLY MON...WITH
PATCHY VLY FOG PSBL ACRS THE TWIN TIERS. AS THE AMS MODIFIES DURG
THE DAY MON...PLENTY OF SUNSHINE SHOULD HELP AFTN TEMPS RECOVER
INTO THE 70S (2-4 DEGS HIGHER THAN ON SUN MOST AREAS).
BY TUE...A RETURN SRLY FLOW DVLPS...LEADING TO WARM AND MOIST
ADVECTION. WE MAY SEE A FEW -SHRA DVLP...BUT MOST OF THESE WILL
LIKELY RESIDE ACRS OUR WRN/SRN ZNS...CLOSER TO PASSING S/WV
ENERGY...AND ALSO AN APPROACHING WARM FRNTL BNDRY. FOR NOW...WE`LL
SIMPLY CALL FOR ISOLD-SCTD SHWRS THESE AREAS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
GDNC COMING INTO BETTER AGREEMENT WITH MID TO LATE WEEK FROPA
ASSCD WITH S/WV ROTATING ARND A CLOSED LOW OVER CNTRL CANADA. SOME
QUESTION ON THE XTNT OF SRN STREAM INFLUENCES ON THIS SYSTEM.
OVERALL...XPCT CDFNT TO PASS MOST OF THE RGN ON THU...ALTHO SOME
LINGERING PCPN PSBL FAR SE ZONES ON FRI CLOSER TO THE RETREATING FNTL
BNDRY. OTRW...HIGH PRES BUILDS INTO THE AREA LATE WEEK INTO NXT
WEEKEND. 2NDRY CDFNT HINTED AT FOR NXT WEEKEND (SAT) BUT IT LOOKS
FAIRLY DRY AT THIS POINT. SO AFTER THURSDAY`S FROPA...GNRLY DRY WX
AND TEMPS AVERAGING NEAR OR A FEW DEG BLO NORMAL. WPC GUIDANCE
LOOKED GOOD AND UTILIZED WITH LTL MODIFICATION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
630 AM EDT UPDATE...
MVFR LAKE EFFECT CLOUDS HAVE DEVELOPED ACROSS MUCH OF THE REGION
THIS MORNING. CLOUDS ARE EXPECTED TO BECOME MORE DENSE AND
WIDESPREAD AS WEST/NORTHWESTERLY WINDS INCREASE THIS MORNING AND
COLDER AIR MOVES ACROSS THE FINGER LAKES. BY MID AFTERNOON CLOUDS
WILL LIFT TO VFR AND START TO SLOWLY DIMINISH. BY SUNDAY NIGHT THE
MAJORITY OF THE CLOUDS WILL DISSIPATE AND RADIATIONAL COOLING WILL
START TO OCCUR. AS RADIATIONAL COOLING TAKES PLACE FOG WILL
DEVELOP ACROSS CENTRAL NEW YORK AND NORTHEAST PENNSYLVANIA. AS THE
NIGHT TRANSITIONS INTO MONDAY MORNING THE FOG WILL BECOME
DENSE...THUS PUT BR IN TAFS FOR KRME... KITH... KELM... AND KBGM
WHERE CONFIDENCE IS HIGHEST WHERE DEVELOPMENT WILL TAKE PLACE.
MON THRU WED...MAINLY VFR.
THU...MVFR IN SHRA AND TSRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ
NEAR TERM...MLJ
SHORT TERM...DGM/MLJ
LONG TERM...
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
330 PM CDT SUN AUG 4 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 330 PM CDT SUN AUG 4 2013
MAIN FORECAST PROBLEM IN THE SHORT TERM PERIOD IS THE CHANCE OF
SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON AND TONIGHT. MODELS
HAVE BEEN HAVING A HARD TIME FIGURING OUT WHAT WILL TRANSPIRE LATE
THIS AFTERNOON INTO THIS EVENING. MANY FAVORABLE FACTORS FOR
CONVECTION ARE IN PLACE. STRONG UPPER LEVEL JET IS PROVIDING GOOD
BULK SHEAR WITH INDIVIDUAL IMPULSES TRACKING ACROSS NORTHEAST
MONTANA AND SOUTHERN SASKATCHEWAN. DEWPOINT HAVE CLIMBED INTO THE
UPPER 50S TO LOWER 60S ACROSS THE AREA WITH AN INVERTED SURFACE
TROUGH TRACKING SLOWLY EAST ACROSS WESTERN NORTH DAKOTA PROVIDING
AN ADDITIONAL FOCUSING MECHANISM FOR CONVECTION. THE LIMITING
FACTOR HAS BEEN THE EXTENSIVE CLOUD COVER PROVIDING MEAGER LOW
LEVEL LAPSE RATES. 19Z KDIK LAPS SOUNDING STILL INDICATES AROUND
100 MB OF CIN TO BE OVERCOME. HOWEVER SKIES ARE BEGINNING TO CLEAR
IN EASTERN MONTANA INTO WESTERN NORTH DAKOTA WITH A GOOD 3 HOURS
OF HEATING BEFORE WE PASS OUR DIURNAL MAX AND CURRENTLY 1000-1500
J/KG OF CAPE AVAILABLE OVER FAR WESTERN NORTH DAKOTA. THE
DIRECTIONAL SHEAR PROFILE DOES BECOME LESS FAVORABLE WITH
SIGNIFICANT DRYING ALOFT TAKING PLACE BEHIND THE INVERTED TROUGH
WHICH CURRENTLY LAYS OVER WESTERN NORTH DAKOTA.
MESOSCALE MODELS HAVE BEEN ALL OVER THE PLACE WITH CONVECTION
ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ABOUT THE ONLY TREND THAT
CAN BE SEEN IS THAT SUCCESSIVE RUNS HAVE BECOME LESS AND LESS
OMINOUS FOR CONVECTION DEVELOPING OVER WESTERN OR CENTRAL NORTH
DAKOTA THIS AFTERNOON OR THIS EVENING. WITH THIS SAID...STILL
THINK THERE IS A WINDOW OF OPPORTUNITY FOR CONVECTION OVER CENTRAL
NORTH DAKOTA LATE THIS AFTERNOON THROUGH LATE EVENING. THE 18Z RAP
SHOWS CONVECTION TRYING TO DEVELOP OVER THE NORTH CENTRAL LATE
THIS AFTERNOON...SPREADING SOUTHWEST INTO SOUTHWEST NORTH DAKOTA
EARLY THIS EVENING. BUT THE STRONGEST CONVECTION REMAIN OVER THE
NORTH CENTRAL INTO EASTERN NORTH DAKOTA...CLOSEST TO THE MID LEVEL
SHORTWAVE TROUGH. THE 12Z WRF DID NOT HAVE A GOOD HANDLE ON
CONVECTION ACROSS THE NORTH...BUT DOES DEVELOP A LINE OF
CONVECTION ACROSS THE SOUTHWEST BETWEEN 21-22Z. EACH SUCCESSIVE
RUN OF THE HRRR CONTINUES DEPICT WEAKER CONVECTION DEVELOPING OVER
CENTRAL AND EASTERN NORTH DAKOTA THIS EVENING.
SETTLED ON A 20-30 POPS OVER THE CENTRAL INTO THE SOUTHWEST LATE
THIS AFTERNOON SPREADING INTO CENTRAL AND EASTERN NORTH DAKOTA
TONIGHT. WILL NOT MENTION SEVERE WORDING BUT A FEW STRONG TO
POSSIBLY SEVERE CELLS CAN NOT BE RULED OUT GIVEN THE STRONG SHEAR
AND INCREASING CAPE.
CONVECTION...IF IT DOES DEVELOP SHOULD MOVE OUT OF THE EASTERN CWA
AFTER MIDNIGHT. WE THEN GET A PERIOD OF UPPER LEVEL RIDGING MONDAY
AHEAD OF THE NEXT SHORTWAVE TROUGH...AND THE STRONG SHORTWAVE
ASSOCIATED WITH THE RETROGRADING UPPER LEVEL LOW OVER DROPPING
DOWN FROM THE HUDSON BAY.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 330 PM CDT SUN AUG 4 2013
THE NORTHERN PLAINS WILL BE UNDER NORTHWEST FLOW ALOFT MONDAY
NIGHT WITH UPPER LEVEL RIDGING ACROSS THE SOUTHERN PLAINS AND
DEEP LOW PRESSURE OVER THE WESTERN HUDSON BAY. WILL SEE
INCREASING CHANCES OF SHOWERS/THUNDERSTORMS MONDAY EVENING WEST
AND LATE MONDAY NIGHT THROUGH TUESDAY MORNING AREA WIDE AS A
POTENT EMBEDDED S/WV ROTATES THROUGH THE FLOW AND INTO NORTH
DAKOTA...IN ADDITION TO A SFC TROUGH/COLD FRONTAL BOUNDARY PUSHING
SOUTH ACROSS THE STATE INTO TUESDAY MORNING.
BY TUESDAY AFTERNOON...THE MAIN AREA OF SHOWERS/THUNDERSTORMS
ASSOCIATED WITH THE COLD FRONT WILL HAVE MOVED SOUTH AND EAST OF
CENTRAL NORTH DAKOTA. WILL NEED TO KEEP AN EYE ON THE SOUTHEAST
DURING THE AFTERNOON FOR A STRONGER STORM WHERE MODELS PROJECT
NEAR 1000 J/KG OF CAPE AND LITTLE IF ANY CIN. BY TUESDAY EVENING THE
UPPER LEVEL LOW IS FORECAST TO BE BETWEEN HUDSON BAY AND LAKE
WINNIPEG...MAINTAINING STRONG NORTHWEST FLOW ALOFT THROUGH
THURSDAY (POSSIBLY INTO FRIDAY) WITH THE UPPER LOW REMAINING
QUASI-STATIONARY. LINGERING LOW LEVEL MOISTURE COUPLED WITH
EMBEDDED ENERGY IN THE FLOW ALOFT WILL MAINTAIN SOME CHANCE FOR
DIURNALLY DRIVEN SHOWERS/ISOLATED THUNDERSTORMS BOTH WEDNESDAY AND
THURSDAY.
UPPER LOW PROPAGATES SLOWLY EAST TO OVER ONTARIO FRIDAY INTO
FRIDAY NIGHT...WITH A RIDGE BUILDING INTO THE MONTANA ROCKIES.
HIGH PRESSURE IS FORECAST TO BUILD ACROSS THE DAKOTAS THURSDAY
NIGHT...REMAINING IN PLACE WELL INTO THE WEEKEND. THIS WILL LEAD
TO MAINLY DRY CONDITIONS AND CONTINUED BELOW NORMAL TEMPERATURES
OVER MOST OF THE CWA THROUGH THE REMAINDER OF THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 330 PM CDT SUN AUG 4 2013
MAIN FEATURE FOR THE 18Z TAF PERIOD WAS MVFR CEILINGS MOST AREAS
THROUGH AROUND 21 UTC. THEN A PERIOD OF VCTS LATE AFTERNOON INTO
MID EVENING FOR KDIK...KBIS AND KMOT...AND AFTER 00Z AT KJMS. WITH
KISN CURRENTLY OVER THE INVERTED TROUGH...DID NOT ADD A MENTION OF
VCTS HERE. ALSO BROUGHT A PERIOD OF IFR CEILINGS INTO KJMS AROUND
10Z-16Z MONDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...TWH
LONG TERM...NH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1259 PM CDT SUN AUG 4 2013
.UPDATE...
ISSUED AT 1044 AM CDT SUN AUG 4 2013
FIRST WEAK WAVE NOW PULLING AWAY ACROSS SOUTHERN MINNESOTA...WITH
CONVECTIVE CLUSTER IN NORTHEAST NEBRASKA AND EXTREME SOUTHEAST
SOUTH DAKOTA. ANOTHER WEAK IMPULSE MOVING ACROSS SOUTH CENTRAL NORTH
DAKOTA AND FAR NORTHERN SOUTH DAKOTA INITIATING NEW CONVECTION
ALONG MID LEVEL BOUNDARY BACK TOWARD NORTH OF KPIR TO KD07. NORTHERN
AREA DEFINITELY LOOKS TO BE THE ONLY LARGER SCALE SUPPORT FOR LIFT
GOING INTO THE AFTERNOON...AND EXPECT SOUTHERN AREA TO START A
MORE NOTABLE WEAKENING TREND IN COVERAGE IN NEXT COUPLE OF HOURS
AS IT PROGRESSES TOWARD SIOUX CITY AND POINT SOUTH/EAST...AS
THERMODYNAMIC SUPPORT FOR DEVELOPMENT CERTAINLY DIMINISHES
EASTWARD...AND DEGREE OF ANY INSTABILITY REALLY ONLY SUPPORTS A
THUNDER THREAT THROUGH MIDDAY IN THE FAR WEST/SOUTH. LIKEWISE...
SHOULD SEE GRADUAL DEMISE OF CLUSTER OF SHOWERS THAT PASSED NEAR
KHON AS IT APPROACHES KFSD TOWARD NOON.
DESPITE CERTAINTY IN THE SHORT TERM BEING FAIRLY LOW...AND MODEL
PERFORMANCE IN WEAKLY FORCED PATTERN DISMAL...HAVE SOME CONFIDENCE
THAT MUCH OF THE AREA THIS AFTERNOON INTO EARLY EVENING SHOULD BE
FREE OF CONVECTION. WILL MAINTAIN AN ISOLATED TO SCATTERED MENTION
IN THE FAR NORTHERN TIER ALONG GLANCING INFLUENCE OF NORTHERN WAVE...
CARRYING WITH IT A GRADUAL SPREAD OF THUNDER MENTION EASTWARD.
TEMPERATURES LOOKED GENERALLY OK FOR THE DAYTIME MAX...BUT MADE AN
ATTEMPT TO ACCOUNT FOR EXPECTED PRECIP AREAS AND COOLER OUTFLOW
FOR THE SHORTER TERM TO DIURNAL TRENDS...AND DID TRIM A FEW AREAS
DOWN A COUPLE DEGREES.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 415 AM CDT SUN AUG 4 2013
MODELS STRUGGLING WITH ONGOING ACTIVITY ACROSS CENTRAL SOUTH DAKOTA
WHICH HAS DEVELOPED WITH AN INCREASING LOW LEVEL JET AND MID LEVEL
WAVE. DRY AIR TO THE EAST AND MINIMAL INSTABILITY IS EXPECTED TO
CAUSE A DOWNWARD TREND IN THIS CONVECTION AS IT ENTERS OUR CWA. OF
ALL THE GUIDANCE...SEEMS LIKE HRRR IS CLOSEST TO REALITY...WITH THE
0Z ECMWF ALSO NOT TOO BAD. BOTH OF THESE MODELS SUGGEST ACTIVITY
DOES INDEED WEAKEN AND DISSIPATE AS IT PUSHES EAST. HAVE HIGH CHANCE
TO LIKELY POPS THIS MORNING WEST OF THE JAMES RIVER...FROM ABOUT 10Z
TO 15Z. NOTHING SEVERE BUT WOULD EXPECT AT LEAST SOME LIGHTNING
ACTIVITY WITH THE STORMS. SHOWERS COULD MAKE IT AS FAR EAST AS
INTERSTATE 29 BY 13Z...BUT NOT REAL CONFIDENT IT WILL HOLD TOGETHER
EVEN THAT FAR...SO WILL ONLY GO SLIGHT CHANCE POPS. PLUS GIVEN THE
EXPECTED WEAKENING STATE...AND LACK OF INSTABILITY...PROBABLY WILL
NOT BE ANY LIGHTNING WITH ANYTHING THAT DOES MANAGE TO GET EAST OF
THE JAMES RIVER. TEND TO THINK WE SEE A LULL IN THE ACTIVITY DURING
THE AFTERNOON HOURS. BUT GIVEN WEAK FORCING...MID LEVEL MOISTURE
PRESENT...ONGOING ACTIVITY CONTINUING TO DEVELOP OVER NORTHWEST
SOUTH DAKOTA...AND THE GENERALLY LOW PREDICTABILITY OF THE
PATTERN...WILL KEEP A LOW CHANCE POPS IN THE WEST THROUGH THE
DAY...WITH SLIGHT CHANCES TO INTERSTATE 29. DAY SHIFT MAY END UP
BEING ABLE TO REMOVE THESE IF IT BECOMES MORE APPARENT DURING THE
MORNING THAT WE SEE A LULL IN THE ACTION. HIGHS TODAY ARE TRICKY AND
DEPENDENT ON REMNANT CLOUD COVER. THINK IT PROBABLY STAYS MOSTLY
CLOUDY FOR MUCH OF THE DAY. DID BUMP HIGHS UP SOME WITH SOME OF THE
NEWER GUIDANCE COMING IN A BIT WARMER...BUT GIVEN CLOUD COVER
CONCERNS DID NOT WANT TO GO TOO WARM...AND WENT WITH MAINLY MID AND
UPPER 70S. IF WE SOMEHOW ARE ABLE TO GET MORE SUN TODAY...HIGHS
WOULD END UP SEVERAL DEGREES WARMER. SO ANOTHER THING THE DAY SHIFT
WILL HAVE TO MONITOR.
UNFORTUNATELY...FORECAST CONFIDENCE DOES NOT INCREASE TONIGHT. THE
CORE OF THE UPPER LEVEL SUPPORT WILL DIVE SOUTHEAST ACROSS
MINNESOTA. SEEMS LIKE A GOOD BET THAT WE SEE ANOTHER ROUND OF
NOCTURNAL CONVECTION ACROSS THE NORTHERN PLAINS. BEST FORCING IS TO
THE NORTHEAST...WITH BEST INSTABILITY AS YOU GO SOUTHWEST. THINK
THE BEST THREAT WILL BE ACROSS SOUTHWEST MINNESOTA CLOSEST TO THE
BEST FORCING...BUT GIVEN INSTABILITY TO THE SOUTHWEST...AND SOME OF
THE HI RES MODELS SHOWING CONVECTION FIRING IN OUR WEST...WILL KEEP
CHANCE POPS ACROSS THE WHOLE CWA. CONFIDENCE IS TOO LOW IN PLACEMENT
AND TIMING TO WARRANT ANY LIKELY POPS AT THIS TIME. ELEVATED
INSTABILITY AROUND 1000 J/KG TONIGHT WOULD SUGGEST A PRETTY GOOD
LIGHTNING THREAT WITH ANYTHING THAT DOES FORM TONIGHT...HOWEVER
SEVERE THREAT SHOULD REMAIN PRETTY LOW...WITH THE ELEVATED NATURE
LIMITING WIND THREAT...AND CAPE PROBABLY TOO LOW FOR MUCH OF A HAIL
THREAT. LOWS WILL BE MILDER TONIGHT...GENERALLY LOW AND MID 60S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 415 AM CDT SUN AUG 4 2013
FOR MONDAY...A COLD FRONT DROPS ACROSS THE REGION EARLY IN THE
DAY...AND OTHER THAN A SLIGHT CHANCE OF POPS IN THE SOUTH AND EAST
EARLY THINK THAT THE REMAINDER OF THE DAY WILL BE DRY IN
SUBSIDENCE/DRYING BEHIND AN EXITING SHORTWAVE. ONLY WEAK COLD AIR
ADVECTION BEHIND THE FRONT...AND WITH MORE SUN THAN TODAY
TEMPERATURES WILL WARM INTO THE UPPER 70S TO MID 80S ACROSS THE AREA
BY AFTERNOON. MOSTLY CLEAR SKIES WILL RULE FOR THE FIRST HALF OF
MONDAY NIGHT...BEFORE CLOUDS BEGIN TO INCREASE IN THE WEST THE
LATTER HALF OF THE NIGHT WITH MID LEVEL WARM AIR ADVECTION. CANNOT
RULE OUT THAT ISOLATED THUNDERSTORMS COULD MAKE IT INTO OUR FAR WEST
BY EARLY TUESDAY MORNING WITH THETA E ADVECTION ON A DEVELOPING LOW
LEVEL JET THROUGH WESTERN SOUTH DAKOTA. LOWS ON MONDAY NIGHT LOOKING
TO BE IN THE UPPER 50S TO LOWER 60S.
ANOTHER COLD FRONT ENCROACHES ON OUR AREA BY TUESDAY AFTERNOON...AND
MAY HAVE BETTER CHANCE OF THUNDERSTORMS ACROSS THE AREA WITH
INCREASING 850 MB THETA E ADVECTION AND INCREASING INSTABILITY OUT
AHEAD OF THE SYSTEM...WITH UPPER LEVEL SUPPORT AS A SHORTWAVE TRACKS
OVER THE AREA. THEIR DOES APPEAR TO BE ENOUGH CAPE AND SHEAR IN OUR
SOUTH AND WEST IN THE AFTERNOON THAT SEVERE STORMS WOULD BE
POSSIBLE. THERMAL PROFILES WARM JUST A BIT OUT AHEAD OF THE
FRONT...THOUGH HIGHS WILL BE DEPENDENT ON TIMING AND EVOLUTION OF
CONVECTION...BUT POTENTIALLY WILL REACH THE UPPER 70S TO MID 80S.
THE FRONTAL BOUNDARY WILL FINALLY PULL ACROSS THE AREA ON TUESDAY
EVENING WITH ANY CONVECTION ENDING FROM WEST TO EAST.
IN THE EXTENDED...WEDNESDAY THROUGH SATURDAY...MODELS IN DECENT
AGREEMENT ON THE DEVELOPMENT OF A CLOSED UPPER LEVEL LOW OVER
CENTRAL CANADA FOR MIDWEEK. THIS FEATURE WILL THEN SLOWLY MIGRATE TO
THE NORTHERN GREAT LAKES REGION BY THE END OF THE WEEK. THIS WILL
KEEP OUR AREA IN A NORTHWESTERLY UPPER LEVEL FLOW WITH BELOW NORMAL
TEMPERATURES THROUGH THE PERIOD. DOES NOT APPEAR TO BE ANY
OUTSTANDING CHANCES OF PRECIPITATION THROUGH THE EXTENDED...THOUGH
THE BEST CHANCE WOULD LOOK TO BE IN THE THURSDAY TO THURSDAY NIGHT
TIME FRAME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1259 PM CDT SUN AUG 4 2013
FAR FROM A CLEAR PICTURE ON THE EVOLUTION OVER THE NEXT 12 TO 24
HOURS. WILL SEE AREA OF CONVECTION AROUND KSUX MOVE THROUGH WITH
ANY REDUCED VISIBILITY IN RAIN LIKELY REMAINING OUT OF MVFR BY
1830Z. IN ITS WAKE...MAY SEE SOME SOME SCATTERED TO BROKEN LOWER
BASED CUMULUS IN THE LOWER MISSOURI VALLEY THROUGH THE AFTERNOON.
ONLY SHOWERS/THUNDER AROUND THE AREA UNTIL AT LEAST THE EVENING
EXPECTED TO BE NEAR MID LEVEL BOUNDARY AROUND KHON...BUT JUST TOO
UNCERTAIN AND LOW OF COVERAGE TO MENTION IN THE KHON TAF AT THIS
POINT. STRONGER FORCING FOR CONVECTION LOOKS TO DEVELOP DURING THE
EVENING HOURS AND INTRODUCED A FEW HOURS AROUND THE MOST CERTAIN
TIMING FOR KFSD AND KHON...AND ANY STORMS WILL THIS TIME LIKELY
HAVE MVFR CONDITIONS. KEPT THE LATTER ACTIVITY CLEAR OF KSUX. WAKE
OF ANY OVERNIGHT CONVECTION IS LIKELY TO RESULT IN MVFR TO IFR
CEILINGS INTO THE MORNING.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHAPMAN
SHORT TERM...CHENARD
LONG TERM...JM
AVIATION...CHAPMAN