Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 07/24/14
AREA FORECAST DISCUSSION
NWS TUCSON AZ
900 PM MST WED JUL 23 2014
.SYNOPSIS...ENOUGH MOISTURE IS BACK IN PLACE FOR A FEW SHOWERS AND
THUNDERSTORMS. HOTTER TEMPERATURES ARE POSSIBLE AGAIN THURSDAY.
THUNDERSTORMS ARE EXPECTED TO INCREASE FRIDAY INTO THE
WEEKEND...ESPECIALLY SATURDAY AFTERNOON AND SATURDAY NIGHT.
&&
.DISCUSSION...STILL A FEW SHOWERS WITH EMBEDDED THUNDERSTORMS AROUND
FIRING ON OUTFLOWS FROM EARLIER ACTIVITY. A GREAT POTENTIAL
CONVECTION DAY WASTED WITH LESS THAN FAVORABLE MID LEVEL TEMPERATURE
PROFILE. TRENDS POINT TOWARD LESS ON THURSDAY WITH MOISTURE AGAIN
TEMPORARILY A CONCERN AS UPSTREAM AREAS IN SOUTHERN NEW MEXICO DRY
OUT A LITTLE. 00Z KTWC SOUNDING CAME IN WITH A HEALTHY 1.6 INCHES
BUT LATEST BLENDED SATELLITE PRECIPITABLE WATER ESTIMATES JUST UNDER
AN INCH IN SOUTH CENTRAL NEW MEXICO AS LOWER LEVELS SHOW SOME DRYING
TRENDS.
UPWARD TREND STARTS AGAIN ON FRIDAY AS WE ADD A SOUTHERLY COMPONENT
TO THE FLOW...AND EVEN MORE ON SATURDAY WITH INVERTED TROUGH
INFLUENCE WRAPPING AROUND THE HIGH.
&&
.AVIATION...VALID THRU 25/03Z.
ISOLATED -SHRA/-TSRA THIS EVENING...WITH CLEARING TRENDS IN THE
EARLY MORNING HOURS. LESS CONVECTION AND CLOUD COVER IN GENERAL
EXPECTED THURSDAY. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...MOISTURE HAS RETURNED TO SOUTHEAST ARIZONA WITH
SCATTERED MAINLY AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS
ACROSS MOST OF SOUTHEAST ARIZONA. THERE WILL BE A BRIEF DOWNTURN IN
STORM COVERAGE THURSDAY BEFORE A MORE TYPICAL MONSOON PATTERN MOVES
IN BY THIS WEEKEND. EXPECT STRONG...GUSTY AND ERRATIC WINDS WITH THE
STRONGER THUNDERSTORMS. POTENTIALLY HOTTER TEMPERATURES THURSDAY
WITH STRONG HIGH PRESSURE NEARBY...BUT WITH THIS MAY BE MITIGATED
SOMEWHAT BY THE MOISTURE.
&&
.PREV DISCUSSION...STORMS ARE CURRENTLY FORMING ACROSS CENTRAL PIMA
COUNTY AND ACROSS THE RIM. STORM MOTION IS PITIFUL THOUGH...WITH
MAYBE 10 MPH OF WESTERLY MOTION WITH THE FASTER MOVING STORMS. GIVEN
THE DECENT PRECIP WATER VALUES...I AM CONCERNED FOR ISOLATED FLOOD
THREAT. LATEST HRRR SEEMS TO HAVE THE BEST HANDLE ON THE CONVECTION
THUS FAR AND HINTS AT CONVECTION FOCUSED MAINLY ACROSS THE CENTRAL
PORTION OF OUR AREA...OR NEAR THE I-10 CORRIDOR. COULD SEE SOME
MARGINALLY SEVERE STORMS TODAY. BUT THE TALL SKINNY CAPE
PROFILE...ALSO NOTED WITH THE .05 NORMALIZED CAPE VALUE...SUGGEST
LIMITED PARCEL ACCELERATION TODAY SO IT MAY BE DIFFICULT TO SUSTAIN
STRONG A LASTING UPDRAFTS.
I INCREASED TOMORROWS MIN TEMPERATURES IN THE VALLEYS BY A FEW
DEGREES BASED ON MIN TEMPS FROM THIS MORNING. THE NEAR RECORD WARM
LOWS ARE AGAIN POSSIBLE UNLESS CONVECTIVE OUTFLOWS PROVIDE LOCALIZED
COOLING. THE UPPER RIDGE AGAIN DROPS SOUTH TOMORROW AND THE MODELS
RESPOND BY DECREASING THE MID LEVEL MOISTURE. SO CONVECTIVE ACTIVITY
SHOULD BE DOWN...BUT THE TEMPS WILL BE UP AGAIN. MOISTURE SLOWLY
RETURNS FRIDAY AND AN INVERTED TROUGH SHOULD MOVE ACROSS THE AREA
SATURDAY. SO WE CURRENTLY FOCUS THE HIGHEST POPS OVER THE NEXT 7
DAYS ON SATURDAY THINKING THE ADDED LIFT FROM THE INVERTED TROUGH
WILL BE ENOUGH TO OVERCOME THE MARGINAL MOISTURE CONTENT. MOISTURE
CONTENT STARTS TO DISSIPATE SUNDAY BEFORE A MORE PRONOUNCED DRYING
TREND BEGINS MONDAY.
NEXT WEEK...THE LONG WAVE PATTERN SHOWS A HIGH AMPLITUDE RIDGE OVER
THE WEST WITH A DEEP TROUGH OVER THE EAST. THIS TYPE OF BLOCKING
PATTERN CAN GREATLY REDUCE THE PRECIP CHANCES AND PROMOTE WARMER
THAN NORMAL CONDITIONS. CERTAINLY CAN NOT RULE OUT SOME ISOLATED
STORMS NEXT WEEK...BUT I`M MORE CONCERNED FOR THE EXCESSIVE HEAT
POTENTIAL. CURRENT GUIDANCE IS SHOWING SIMILAR TEMPS AS WE
EXPERIENCED THIS WEEK...BUT 850-700MB THICKNESS VALUES SUGGEST WE
MAY BE A FEW DEGREES TOO COOL FOR MAX TEMPS NEXT WEEK.
JJB
&&
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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MEYER/CERNIGLIA
AREA FORECAST DISCUSSION
NWS TUCSON AZ
910 PM MST MON JUL 21 2014
.SYNOPSIS...EXPECT ISOLATED TO SCATTERED THUNDERSTORMS MOSTLY EAST
AND SOUTH OF TUCSON THROUGH THE MIDDLE OF THIS WEEK. MUCH HOTTER
TEMPERATURES WILL OCCUR TUESDAY THROUGH THURSDAY...WITH NEAR RECORD
HIGHS POSSIBLE. AN INCREASE IN THUNDERSTORM ACTIVITY SHOULD OCCUR
LATE IN THE WEEK AND INTO THE WEEKEND.
&&
.DISCUSSION...AFTER A VERY QUIET JULY DAY...04Z IR IMAGERY WAS
SHOWING SCT-BKN SKIES OVER MUCH OF COCHISE...GREENLEE...GRAHAM...AND
SANTA CRUZ COUNTIES THIS EVENING. THE COOLEST CLOUD TOPS WERE IN
EXTREME SERN COCHISE COUNTY IN THE VICINITY OF KDUG IN THE FORM OF
SOME REMNANT DEBRIS CLOUDS FROM EARLIER THUNDERSTORM ACTIVITY IN NRN
SONORA MEXICO. AREA TEMPS GENERALLY RANGED FROM THE UPPER 70S IN
SOME OF THE HIGHER ELEVATIONS TO THE MID 90S IN THE WESTERN
DESERTS OF PIMA COUNTY...WITH SFC DEWPOINTS MAINLY IN THE 30S AND
40S EXCEPT NEAR THE INTERNATIONAL BORDER WHERE A FEW SPOTS WERE A
BIT MORE MOIST. LATEST RUN OF THE HRRR WAS TRYING FOR SOME LIGHT
PRECIP OVER SERN COCHISE CNTY BETWEEN 05Z AND 09Z TONIGHT...LIKELY
HITTING ON THE THICKER CLOUD COVER AND HIGHER DEWPOINTS. THE TWO
LOCAL WRF MODELS REMAINED DRY FOR THAT PERIOD. AS SUCH...HAVE CHOSEN
TO LEAVE IN ONLY SINGLE DIGIT POPS FOR THAT AREA...AS WE ARE LIKELY
TOO STABLE FOR ANY PRECIP TO OCCUR. FOLLOWING LATEST SATELLITE
TRENDS...AREAS TO THE SOUTH AND EAST OF TUCSON WILL LIKELY SEE THE
GREATEST PERCENTAGE OF CLOUD COVER OVERNIGHT TONIGHT...WITH WRN
PORTIONS FILLING IN WITH SOME MID AND HIGH LVL CLOUDS AS WE CLOSE IN
ON DAYBREAK. THE REST OF THE FORECAST IS ON TRACK...SO NO FURTHER
UPDATES ARE NEEDED. FOR MORE INFORMATION...PLEASE SEE THE PREVIOUS
DISCUSSION BELOW.
&&
.AVIATION...VALID THRU 23/06Z.
ISOLATED -TSRA/-SHRA WILL OCCUR MOSTLY EAST AND SOUTH OF KTUS
TUESDAY AFTERNOON AND TUESDAY EVENING. BRIEF WIND GUSTS TO NEAR 35
KTS MAY OCCUR WITH THIS ACTIVITY. OTHERWISE...EXPECT MOSTLY CLEAR
SKIES WEST OF KTUS AND A FEW TO BROKEN CLOUDS MAINLY ABOVE 10K FT
AGL EAST TO SOUTH OF KTUS THROUGH TUESDAY EVENING. AVIATION
DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...THUNDERSTORM ACTIVITY WILL INCREASE ACROSS SOUTHEAST
ARIZONA STARTING TUESDAY...THEN SCATTERED MOSTLY AFTERNOON AND
EVENING THUNDERSTORMS WILL PREVAIL BY THIS WEEKEND. EXPECT STRONG...
GUSTY AND ERRATIC WINDS WITH THE STRONGER THUNDERSTORMS. HOTTER
TEMPERATURES WILL ALSO OCCUR TUESDAY THROUGH THURSDAY FOLLOWED BY A
COOLING TREND BY THE WEEKEND.
&&
.PREV DISCUSSION...TUESDAY SHOULD SEE A SLIGHT UPTICK IN
THUNDERSTORM CHANCES AS THE HIGH SHIFTS TO A POSITION OVER WESTERN
COLORADO AND PWATS ARE EXPECTED TO INCREASE TO AROUND 1.3 - 1.4
INCHES. BY WEDNESDAY THE HIGH WILL BE OVER EASTERN COLORADO AND
WESTERN KANSAS WITH THE RIDGE AXIS NOSING INTO THE DESERT
SOUTHWEST...RESULTING IN SIGNIFICANTLY WARMER TEMPERATURES. PWATS
WILL CONTINUE IN THE 1.2 - 1.6 INCH RANGE FROM TUCSON TOWARD
AJO...WITH LOWER VALUES ALONG THE NEW MEXICO BORDER. GIVEN
THAT...EXPECT AN EVEN BETTER CHANCE WEDNESDAY AFTERNOON FOR MOST
AREAS...EXCEPT FOR AREAS ALONG THE IMMEDIATE BORDER WITH NEW MEXICO.
BY THURSDAY ANOTHER DOWN SWING IN ACTIVITY IS EXPECTED AS THE HIGH
BECOMES CENTERED OVER EASTERN ARIZONA AND MUCH OF NEW MEXICO...AND
DRIER PWATS MOVE IN FROM THE EAST...WITH READINGS BELOW THE 1 INCH
MARK FROM TUCSON EASTWARD.
BY FRIDAY...BUT ESPECIALLY THIS WEEKEND...WE SHOULD SEE A FAIRLY
SIGNIFICANT INCREASE IN THUNDERSTORM ACTIVITY AS AN UPPER LEVEL
DISTURBANCE OVER NORTHERN MEXICO MOVES NORTHWEST ACROSS PARTS OF
SONORA...SOUTHERN ARIZONA AND NORTHERN BAJA...AND THE HIGH BECOMES
ORIENTED FROM SRN UTAH ACROSS NORTHEAST ARIZONA AND INTO NORTHERN
NEW MEXICO. THIS SETUP WILL GIVE ARIZONA A FAIRLY LONG EAST TO
SOUTHEASTERLY FETCH FOR ADDITIONAL MOISTURE TO SPILL INTO THE
REGION. THE HIGH TRANSITIONS OVER THE AZ/NM BORDER MONDAY FOR A
DECREASE IN ACTIVITY.
HIGH TEMPERATURES ABOVE NORMAL THROUGHOUT THE FORECAST PERIOD...BUT
THE WARMEST DAYS WILL OCCUR WEDNESDAY THROUGH FRIDAY...WHEN READINGS
WILL BE 8 TO 12 DEGS ABOVE NORMAL. OTHERWISE...EXPECT HIGHS TO BE 3
TO 6 DEGS ABOVE NORMAL. LOWS GENERALLY 4 TO 6 DEGS ABOVE NORMAL EACH
DAY...BUT THE WARMEST MORNINGS SHOULD OCCUR WEDNESDAY THROUGH
FRIDAY.
.TWC WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
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DISCUSSION...FRENCH
PREV DISCUSSION...MOLLERE
AVIATION/FIRE WEATHER...FRANCIS
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
200 PM PDT Tue Jul 22 2014
.Synopsis...
An upper wave moves over NorCal today with showers and potential
thunderstorms. Then expect a warming trend Wednesday into the
weekend.
&&
.Short Term Discussion (Today through Thursday)...
An upper level disturbance continues to lift northeastward through
Northern California this afternoon. This system is interacting
with the remaning monsoonal moisture aloft and has spread
sprinkles to light rain across portions of the Northern San
Joaquin and Sacramento valley so far today. A few stray lightning
strikes were detected near Auburn and Chico as well. Short term
guidance initially underestimated the instability/precipitation
generated from this event however the HRRR caught up to
observations by 18Z. Radar imagery has consistently shown
southwest to northeast oriented band of precipitation of light
precipitation stretching across Northern California this morning.
This line is forming along an air mass boundary formed by the
aforementioned upper level disturbance and should continue to push
north-northeastward this afternoon into evening. A secondary line
developed just south of the main band of precipitation.
Precipitation so far has been fairly light in this band, with most
stations recording a trace to around a tenth of an inch.
The upper disturbance moves out of the area overnight. Winds
become breezy through the Delta and over the mounatins tonight
into Wednesday as the pattern shifts. The atmosphere dries out by
midweek and leaves behind a more stable atmosphere under southwest
flow aloft. Temperatures warm to above average for Thursday and
Friday after skies clear and high pressure backbuilds from the
desert southwest. Triple digit temperatures are possible in the
latter half of the week.
.Extended Discussion (Saturday through Tuesday)
High pressure ridge building in from the Desert Southwest will
result in above normal temperatures through the weekend and into
early next week. Portions of the Central Valley will likely be
reaching 100+ temperatures during this timeframe. There may be
enough onshore flow through the Delta to keep Delta Breeze-
influenced areas just below the triple-digit threshold.
Medium-range models continue to suggest monsoonal moisture
advecting northward. At this stage, a slight chance of
thunderstorms will be possible south of Tahoe on Sunday, with
perhaps a more widespread chance over the Sierra on Monday.
Dang
&&
.Aviation...
Mainly VFR conditions expected the next 24 hours, with scattered
mid to high clouds over the area. Isolated SHRA with a slight
chance of TS will be possible generally north of KCIC through
about 04z.
Across the Valley, south to west winds 5 to 15 kt will continue
through Wednesday. Near the Delta, southwest winds 15 to 30 kt
will be possible through Wed.
Dang
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
426 AM PDT Tue Jul 22 2014
.Synopsis...
An upper wave moves over NorCal today with showers and potential
thunderstorms. Then expect a warming trend Wednesday into the
weekend.
&&
.Short Term Discussion (Today through Thursday)...
An upper level disturbance is lifting northward off the central CA
coast this morning. Yesterday, this wave didn`t appear to be too
unstable, and we only really had thunderstorm activity over the
northern mountains with the max heating of the afternoon.
However, looking at HRRR Composite Ref, NAM/GFS ModTT forecast
procedures, as well as actual isolated showers/thunderstorms west
of Monterey and Half Moon Bays, the instability is a bit more than
anticipated this morning. Therefore, we have added isolated
showers/thunderstorms this morning for the NW side of our forecast
area from Lake/Yolo through Shasta/western Plumas counties. Then we
kept the afternoon thunderstorm mention over just the northern
mountains to include some of the Sierra. These storms this morning
are moving at nearly 40 mph to the NNE. They are making it into
San Fran Bay Area as of 410 am and we expect showers to be over
Lake/Yolo county area around sunrise.
The short wave disturbance moves out of the area tonight and by
Wednesday, the atmosphere is more stable under the southwest flow
aloft with the main upper level trough just offshore of NW CA. Wind
will likely be breezy through the Delta and over the mountains
Wednesday with a shot at seeing some marine stratus advect into and
develop within the southern Sacramento Valley early in the
morning. So we will have to wait until Thursday to really see the
max temperatures climb and humidity lower. JClapp
.Extended Discussion (Friday through Tuesday)
Ridging building in from the Desert SW over NorCal through the
extended period resulting in warming temperatures. Some triple
digit heat is possible in portions of the Central Valley by Friday
becoming more widespread over the weekend. Models showing
relatively dry atmosphere into the first half of the weekend but
show some monsoonal moisture advecting northward. The GFS/EC have
southeast flow aloft with an embedded wave over southern/western
NV on Sunday/Monday with a hint of monsoon moisture creeping up
the Sierra. The timing of any moisture surge is debatable at this
time, but the main theme is the increasing potential for another
round of a subtropical surge and resultant thunderstorm
development, mainly over the mountains, late in the forecast
period. JClapp
&&
.Aviation...
General VFR conditions today with scattered mid clouds, though
isolated SHRA/TSRA possible over the Coastal and northern mtns, and
extending into western and northern portions of the Sacramento
Valley. Southerly Valley winds gusting to 20 kt north of I80, 18z-
06z. Delta Breeze gusting to 30 kt. EK
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
339 PM MDT TUE JUL 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 338 PM MDT TUE JUL 22 2014
TOWERING CUMULUS HAS BEEN CONFINED TO THE FRONT RANGE MOUNTAINS
AND FOOTHILLS...AND PARK COUNTY SO FAR...WITH ANY PRECIPITATION
JUST SOUTH OF THE FORECAST AREA TOWARD THE PIKES PEAK REGION.
STILL EXPECT ISOLATED SHOWERS/STORMS TO DEVELOP IN THE FRONT RANGE
MOUNTAINS AND FOOTHILLS LATE THIS AFTERNOON. IN THE LOWER
ELEVATIONS...THE CAP IS WEAKENING AS WE HAVE HAD FULL SUNSHINE
THROUGH THE DAY. LATEST ACARS SOUNDINGS SHOW IF WE REACH 95 NEAR
DENVER WE COULD BREAK THE CAP. AT THIS TIME...IT WOULD STILL BE
MORE LIKELY FOR THIS TO OCCUR ALONG THE ELEVATED TERRAIN OF THE
PALMER DIVIDE OR CHEYENNE RIDGE. THE LATEST HRRR AND RAP13 HINT
AT THIS...SO WILL CONTINUE THE LOW POPS IN/NEAR THOSE AREAS. ONLY
CHANGE TO WEATHER WAS TO ADD SOME LOW POPS OVER THE NORTHEAST
PLAINS LATE THIS EVENING AND OVERNIGHT AS LOW LEVEL JET AND
MOISTURE CONVERGENCE INCREASE. HOWEVER...THIS OCCURS UNDER A LARGE
DOMINATING RIDGE SO ONLY A SLIGHT CHANCE OF BREAKING THROUGH THE
CAP AT THIS POINT.
AREAS OF STRATUS MAY DEVELOP OVER THE EASTERN PLAINS AS WELL WITH
CONTINUED ADVECTION OF LOW LEVEL MOISTURE IN UPSLOPE
EAST/SOUTHEAST FLOW.
ON WEDNESDAY...LOW LEVEL FLOW TURNS FROM SOUTHEAST TO MORE
SOUTHERLY AS LEE TROUGH STRENGTHENS. LOOKS LIKE DENVER CONVERGENCE
ZONE WILL GET ERODED AS LEE TROUGH DEVELOPS AND STRONGER MIXING
OCCURS. AS A RESULT...BEST MOISTURE WILL LIKELY SHIFT NORTHWARD TO
NEAR THE WYOMING BORDER AREA BY AFTERNOON. CAPES THERE MAY REACH
1000-1500 J/KG WITH A STRONGER STORM POSSIBLE. ELSEWHERE...LOOKS
LIKE CONVECTION WILL BE HIGHER BASED WITH STRONG GUSTY OUTFLOW
WINDS AND BRIEF MODERATE RAIN. STORM COVERAGE WILL BE HIGHEST IN
MOUNTAINS WHERE A MID LEVEL MOISTURE PLUME IS EXPECTED TO ARRIVE
BY MID/LATE AFTERNOON.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 338 PM MDT TUE JUL 22 2014
SOME THUNDERSTORMS WILL CONTINUE WEDNESDAY EVENING...MAINLY ACROSS
THE MOUNTAINS. MAIN THREAT TO BE GUSTY OUTFLOW WINDS AS LOW LEVEL
MOISTURE WILL BE LIMITED. STORMS SHOULD END AROUND MIDNIGHT AS
AIRMASS STABILIZES. ON THURSDAY...UPPER RIDGE WILL BE OVER THE
AREA WITH THE CENTER OF HIGH OVER CENTRAL NEW MEXICO. RIDGE GETS
FLATTENED A BIT AS MID LEVEL SHORTWAVE MOVES ACROSS NORTHERN
COLORADO WITH FLOW ALOFT BECOMING A BIT MORE WESTERLY. THERE IS
SOME INCREASE IN MONSOON TYPE MOISTURE INTO COLORADO...MAINLY
ACROSS THE MOUNTAINS. THIS WILL PROVIDE FOR A CHANCE OF AFTERNOON
AND EVENING THUNDERSTORMS...WITH THE BEST CHANCE OVER THE
MOUNTAINS. STORMS TO PRODUCE GUSTY WINDS WITH BRIEF MODERATE RAIN.
FOR FRIDAY...UPPER RIDGE REMAINS OVER THE AREA WITH WESTERLY FLOW
ALOFT. MODELS INDICATE ANOTHER INFLUX OF MONSOONAL MOISTURE FLOW
INTO THE AREA...MAINLY ACROSS THE MOUNTAINS. DAYTIME HEATING TO
GENERATE SOME THUNDERSTORMS DURING THE AFTERNOON AND EVENING. A
WEAK SURFACE FRONT LOOKS TO MOVE ACROSS THE NORTHEAST PLAINS WITH
SOME SLIGHT LOW LEVEL COOLING. THIS MAY LIMIT THE THUNDERSTORM
CHANCES ACROSS THE PLAINS AND WILL KEEP THE BEST CHANCE FOR
THUNDERSTORMS OVER THE MOUNTAINS. HIGHS TO BE A FEW DEGREES COOLER
ACROSS NORTHEAST COLORADO...BUT SHOULD STILL BE IN THE LOWER AND
MIDDLE 90S. ON SATURDAY...MODELS SHOW THE UPPER RIDGE RETROGRADING
A BIT WITH THE FLOW ALOFT OVER COLORADO BECOMING WEST NORTHWEST.
MODELS SHOW SOME DECREASE IN THE MONSOON MOISTURE WITH MOST OF THE
MOISTURE BEING DISPLACED OVER SOUTHERN COLORADO. GFS STILL DRIER
THAT THE ECMWF...ESPECIALLY AT LOW LEVELS. WILL CONTINUE WITH A
SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS. THERE
APPEARS TO BE A MID LEVEL SHORTWAVE WHICH MOVES ACROSS ACROSS
NORTHEAST COLORADO DURING THE AFTERNOON...PUSHING ANOTHER WEAK
FRONT INTO THE AREA. LIFT WITH THIS WAVE MAY HELP INCREASE THE
THUNDERSTORM CHANCES. FOR NOW WILL KEEP THE BEST CHANCE OVER THE
HIGH COUNTRY. HIGHS TO BE IN THE LOW AND MID 90S ACROSS THE
PLAINS.
FOR THE LATER DAYS...SUNDAY THROUGH TUESDAY. FLOW ALOFT TO BECOME
NORTHWEST SUNDAY. BOTH ECMWF AND GFS SHOW A SURFACE HIGH MOVING
INTO NORTHEAST PLAINS WITH LOW LEVEL FLOW BECOME SOUTHEAST. THIS
WILL HELP BRING SOME LOW LEVEL MOISTURE INTO THE AREA. FOR NOW
WILL KEEP THE BEST CHANCE OF THUNDERSTORMS OVER THE MOUNTAINS.
COOLER AIRMASS WITH HIGHS IN THE MID 80S ACROSS THE PLAINS.
NORTHWEST FLOW ALOFT CONTINUES MONDAY AND TUESDAY WITH HIGHS
SLIGHTLY BELOW AVERAGE ACROSS NORTHEAST COLORADO. ENOUGH MOISTURE
FOR A SLIGHT CHANCE OF AFTERNOON AND EVENING THUNDERSTORMS EACH
DAY...MAINLY OVER THE MOUNTAINS.
&&
.AVIATION...(FOR THE TAFS THROUGH 00Z WEDNESDAY LATE AFTERNOON)
ISSUED AT 338 PM MDT TUE JUL 22 2014
VFR CONDITIONS ARE EXPECTED TO PERSIST. ONLY A SLIGHT 10 PERCENT
CHANCE OF A STORM PASSING MAINLY TO THE SOUTH OF THE FRONT RANGE
AIRPORTS WHICH COULD PRODUCE BRIEF GUSTY OUTFLOW WINDS TO 25-30
KTS. OTHERWISE EAST/SOUTHEAST WINDS WILL TURN MORE SOUTHERLY BY
05Z-08Z...AND THEN LIGHT/VARIABLE BY 10Z-14Z AS WEAK DENVER
CYCLONE DEVELOPS. SOME STRATUS BELOW 1000 FT AGL POSSIBLE BUT AT
THIS TIME THREAT WOULD BE WELL EAST AND NORTH OF KDEN AND KBJC.
ON WEDNESDAY...SOUTHERLY WINDS WILL DEVELOP AND INCREASE TO
12G20KTS BY 18Z-21Z. ONLY A SLIGHT 20 PERCENT CHANCE OF STORMS
AFTER 21Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM...D-L
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1132 PM MDT MON JUL 21 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 328 PM MDT MON JUL 21 2014
REMNANT MONSOON MOISTURE PLUME EXTENDS ACROSS CENTRAL AND SOUTHEAST
COLORADO WITH WEAK SHORTWAVE ACROSS SOUTHEAST CO EXPECTED TO LIFT TO
THE NORTHEAST THIS AFTERNOON WITHIN THE UPPER HIGH. SO FAR...CLOUDS
HAVE BEEN HOLDING DOWN THE HEATING...WHICH HAS KEPT TEMPERATURES
FROM HITTING 100 ALONG THE I-25 CORRIDOR AND ADJACENT PLAINS.
FARTHER EAST A BIT MORE SUN WILL LIKELY ALLOW TEMPERATURES TO HIT
LOWER 100S OUT TOWARDS LAA. INSTABILITY STILL LOOKS BEST THIS
AFTERNOON TO THE EAST OF A LINE FROM EADS TO LAS ANIMAS TO KIM. IF
DEW POINTS CAN STAY IN THE LOWER 50S...THEN 1500 J/KG (OR A LITTLE
BETTER) OF CAPE WILL REMAIN IN PLACE ACROSS THE FAR SOUTHEAST
PLAINS. WEAK FLOW WITHIN THE UPPER RIDGE WILL KEEP DEEP LAYER
SHEARS ON THE WEAK SIDE FOR MOST OF THE AREA...WHICH SHOULD LIMIT
STORM ORGANIZATION. BUT WITH DOWNDRAFT CAPES OF 1500+ J/KG...GUSTY
OUT FLOW WINDS TO AROUND 60 MPH...AND HAIL NEAR 1 INCH IN DIAMETER
WILL BE POSSIBLE WITH STORMS IN THIS AREA. ELSEWHERE...GUSTY WINDS
AND LIGHTNING LOOK TO BE THE MAIN THREAT. ATMOSPHERE DOES NOT LOOK
VERY CONDUCIVE FOR FLASH FLOODING ON AREA BURN SCARS TODAY...BUT FOR
THE WALDO IT DOESN`T TAKE MUCH TO CAUSE PROBLEMS...SO THIS AREA WILL
BE MONITORED CLOSELY. LATEST HRRR SUGGESTS WALDO WILL BE MISSED
TODAY.
FRONT DROPS THROUGH THE PLAINS EARLY TUESDAY MORNING AND MONSOON
PLUME APPEARS TO GET SHUNTED OFF TO THE SOUTH...THOUGH AT LEAST SOME
RESIDUAL MOISTURE WILL REMAIN IN PLACE. MOISTURE RETURN BEHIND THE
FRONT LOOKS MEAGER...SO OVERALL...IT LOOKS LIKE ANOTHER DAY OF
MAINLY ISOLATED THUNDERSTORMS. IF DEW POINTS CAN INCREASE INTO THE
LOWER TO MID 50S AS NAM12 SUGGESTS...WE COULD SEE ANOTHER STRONG TO
MARGINALLY SEVERE THUNDERSTORM DAY ACROSS THE FAR SOUTHEAST PLAINS
AGAIN. HAVING A HARD TIME BUYING THE 100+ TEMPERATURES ADVERTISED
BY GUIDANCE FOR PUB. SOME LOWER 100S OUT ON THE FAR SOUTHEAST
PLAINS LOOK REASONABLE...BUT KEPT TEMPERATURES A TAD LOWER FOR PUB
AS GUIDANCE HAS BEEN RUNNING TOO HOT LATELY AND EASTERLY WINDS DON`T
USUALLY BODE FOR SUCH WARM TEMPERATURES. AS FOR FLASH FLOOD THREAT
ON THE BURN SCARS...THIS STILL LOOKS RATHER LOW AT THIS POINT. -KT
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 328 PM MDT MON JUL 21 2014
TUESDAY NIGHT-WEDNESDAY NIGHT...A BROAD...HOT (600DM) UPPER HIGH
CONTINUES TO BUILD ACROSS THE STATE WITH THE MAIN MONSOONAL MOISTURE
PLUME BEING SHUNTED INTO THE DESERT SW THROUGH THE GREAT BASIN AND
WESTERN COLORADO...AS FLOW ALOFT BECOMES MORE SOUTH TO SOUTHEAST
ACROSS THE AREA. CONVECTION TO BE ON THE WANE TUESDAY EVENING WITH
GFS LIKELY OVERDONE IN ITS QPF FIELD...THOUGH HAVE KEPT SOME
ISOLATED POPS ACROSS THE SW AND CENTRAL MTS THROUGH THE OVERNIGHT
HOURS. A WEAK BACKDOOR COLD FRONT MOVES ACROSS EASTERN COLORADO
EARLY WEDNESDAY MORNING WITH BREEZY EAST TO SOUTHEAST LOW LEVEL
UPSLOPE STRENGTHENING THROUGH THE AFTERNOON ACROSS THE PLAINS. WITH
ENOUGH MOISTURE UNDERNEATH THE HIGH...ALONG WITH A POSSIBLE WEAK
DISTURBANCE MOVING THROUGH THE SOUTHERLY FLOW ALOFT ACROSS THE
EASTERN GREAT BASIN...SHOULD SEE SCATTERED AFTERNOON AND EVENING
STORMS OVER AND NEAR THE HIGHER TERRAIN...WITH THE BEST COVERAGE
ACROSS THE SW AND CENTRAL MTS. LOCALLY HEAVY RAINFALL REMAINS
POSSIBLE...ESPECIALLY ACROSS WESTERN COLORADO...WITH MODEL SOUNDINGS
INDICATING CAP TO HOLD ACROSS THE PLAINS THROUGH THE AFTERNOON
THOUGH HAVE KEPT SLIGHT POPS IN PLACE INTO THE EVENING HOURS. WITH
MORE CONVECTIVE CLOUD COVER AND DEVELOPING UPSLOPE FLOW...HIGH
TEMPERATURES TO BE A TAD COOLER ON WEDNESDAY ACROSS THE AREA DESPITE
THE UPPER RIDGING IN PLACE.
THURSDAY-FRIDAY...UPPER HIGH PROGGED TO SLOWLY RETROGRADE SOUTH AND
WEST INTO THE FOUR CORNERS REGION WITH SOME RESIDUAL MOISTURE
REMAINING WITHIN THE DEVELOPING WESTERLY FLOW ALOFT ACROSS THE
STATE. SHOULD CONTINUE TO SEE SCATTERED DIURNAL CONVECTION ACROSS
THE HIGH TERRAIN ON THURSDAY WITH A FEW STORMS MOVING ACROSS THE
PLAINS THROUGH THE EVENING HOURS...WITH ANOTHER WEAK BACKDOOR FRONT
MOVING ACROSS THE AREA. MUCH OF THE SAME EXPECTED ON FRIDAY...WITH
SLIGHTLY BETTER COVERAGE ACROSS THE EASTERN PLAINS WITH LOW LEVEL
UPSLOPE FLOW. TEMPERATURES TO BE AT OR ABOVE NORMAL THROUGH THE
PERIOD.
SATURDAY-MONDAY...UPPER HIGH CONTINUES TO BUILD NORTH AND WEST
ACROSS THE GREAT BASIN WITH BROAD NORTHWEST DEVELOPING ACROSS THE
STATE AS AN UPPER TROUGH CARVES OUT ACROSS THE CENTRAL CONUS.
THIS PATTERN LOOKS TO DRY OUT THE UPPER LEVELS OF THE ATMOSPHERE
WITH OCCASIONAL SHORT WAVES AND ASSOCIATED FRONTS MOVING ACROSS
THE NORTHERN AND CENTRAL HIGH PLAINS KEEPING AMPLE LOW LEVEL
MOISTURE IN PLACE ACROSS EASTERN COLORADO. WITH THAT SAID...SHOULD
CONTINUE TO SEE DAILY CHANCES OF SHOWERS AND THUNDERSTORMS...WITH
INCREASING CONCERNS FOR SEVERE WEATHER AND LOCALLY HEAVY RAINFALL
ACROSS EASTERN COLORADO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM MDT MON JUL 21 2014
VFR CONDITIONS ALL TERMINALS TONIGHT AND THROUGH 18Z TUE WITH
LIGHT WINDS. TUE AFTERNOON...TSRA WILL AGAIN DEVELOP OVER THE
MOUNTAINS AND SPREAD ACROSS THE LOWER ELEVATIONS LATE IN THE DAY.
INCLUDED A VCTS MENTION AT KALS FOR A FEW HRS LATE AFTERNOON INTO
THE EVENING...WITH GUSTY WINDS THE MAIN THREAT NEAR ANY STORMS.
FOR KCOS...WEAK SURFACE BOUNDARY WILL PUSH THROUGH THE AREA DURING
THE LATE AFTERNOON...POSSIBLY SERVING AS THE FOCUS FOR A FEW
STORMS AWAY FROM THE MOUNTAINS LATE...MAINLY 22Z-03Z PERIOD...SO
INCLUDED A VCTS MENTION HERE AS WELL. AGAIN...GUSTY WINDS THE
MAIN STORM THREAT. LEFT VCTS OUT OF KPUB ANS BEST LIFT MAY STAY
NORTH OF THE AIRPORT...THOUGH CONVECTION ALONG PLAINS SURFACE
BOUNDARY WILL NEED TO BE WATCHED AS OUTFLOW WINDS COULD HELP
DEVELOP AN ISOLATED TSRA FARTHER SOUTH AFTER 00Z.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...MW
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
428 PM EDT TUE JUL 22 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE AS A COLD FRONT
APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS FROM
WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE
ON FRIDAY. THE HIGH WILL WEAKEN ON SATURDAY...THEN LOW PRESSURE
PASSING TO THE SOUTHEAST WILL IMPACT THE AREA SUNDAY INTO MONDAY.
AN ASSOCIATED COLD FRONT WILL APPROACH LATE DAY MONDAY...AND MOVE
ACROSS MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SOME WEAK UPPER LEVEL ENERGY WILL SPILL OVER THE TOP OF THE RIDGE
ALONG THE NORTHEAST THIS EVENING. SOME WIDELY ISOLATED SHOWERS AND
POSSIBLE THUNDERSTORMS MAY DEVELOP EARLY IN THE EVENING HOURS...
MAINLY NORTH AND WEST OF NYC. WILL CAP POPS AT 20 PERCENT...AS NOT
EXPECTING MANY...IF ANY...STORMS. LATEST HRRR GUIDANCE CONTINUES
TO INDICATE SOME SHOWERS...MAINLY WEST OF THE HUDSON RIVER AND
INTO INTERIOR PORTIONS OF SW CT. ANY SHOWERS THAT DEVELOP WILL END
BETWEEN 9-10 PM.
WARM AND HUMID NIGHT ON TAP WITH LOWS IN THE 60S TO LOW 70S. THE
WARMEST TEMPS WILL OCCUR IN/AROUND NYC DUE TO THE URBAN HEAT
ISLAND EFFECT. SFC DEW POINTS WILL CLIMB THROUGH THE MID 60S AND
INTO THE UPPER 60S. CAN EXPECT PATCHY FOG TO DEVELOP AWAY FROM THE
CITY.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING WITH
ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
HOT AND INCREASINGLY HUMID AIR MASS REMAINS OVER THE AREA
WEDNESDAY. WITH HIGH PRES DEPARTING AND COLD FRONT APPROACHING
FROM THE WEST...SW FLOW INCREASES THROUGHOUT THE DAY...AND SFC
DEWPOINTS WILL RISE THROUGH THE 60S AND INTO THE LOWER 70S. MAX
TEMPS ON WEDNESDAY WILL TOP OFF IN THE LOWER 90S ACROSS NYC AND NE
NJ...AND WILL BE IN THE UPPER 80S TO NEAR 90 ELSEWHERE. TEMPS WILL
BE SIGHTLY COOLER NEAR THE COASTS. THE HEAT INDEX ON WEDNESDAY
WILL GENERALLY TOP OFF IN THE LOW TO MID 90S...EXPECT FOR NYC/NE
NJ...WHERE THE HEAT INDEX WILL BE IN THE MID TO UPPER 90S. SINCE
THE HEAT INDEX IN NYC WILL NOT REACH 95 FOR 2 CONSECUTIVE
DAYS...AND SINCE THE HEAT INDEX WILL REMAIN BELOW 100 ACROSS THE
CWA...WILL NOT ISSUE A HEAT ADVISORY.
AS COLD FRONT APPROACHES...SHOWERS AND THUNDERSTORMS WILL DEVELOP
NORTH AND WEST OF NYC IN THE AFTERNOON ALONG A PRE-FRONTAL TROUGH.
SHOWERS AND THUNDERSTORMS SPREAD EAST WEDNESDAY EVENING AND
WEDNESDAY NIGHT...AND THE BULK OF THE ACTIVITY SHOULD HOLD OFF
UNTIL WEDNESDAY NIGHT AS THE COLD FRONT PASSES THROUGH THE REGION.
WITH THE HEAT AND HUMIDITY...ML MUCAPE VALUES WILL RANGE FROM
1000-1500 J/KG DURING THE DAY...AND THEN WILL DROP TO AROUND 400
J/KG AT NIGHT WITH THE LOSS OF THE HEATING. 0-6 KM BULK SHEAR WILL
BE WEAK DURING THE DAY...AND THEN WILL RISE TO 25-35 KT AFTER 00Z
THURSDAY. CANNOT RULE OUT STRONG WINDS WITH ANY THUNDERSTORMS...
BUT PRIMARY THREAT WILL BE HEAVY RAIN DUE TO PWATS AROUND 2".
FLASH FLOODING OF LOW LYING AND POOR DRAINAGE AREAS IS POSSIBLE.
WILL NOT ISSUE A HAZARDOUS WEATHER OUTLOOK AS THE THREAT WILL NOT
BE WIDESPREAD.
SHOWERS AND THUNDERSTORMS TAPER OFF FROM WEST TO EAST WEDNESDAY
NIGHT AS THE COLD FRONT WORKS ITS WAY ACROSS THE REGION.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE SFC COLD FRONT SHOULD BE TO THE EAST THU MORNING...BUT WITH THE
H8 FRONT STILL YET TO MOVE ACROSS...A MID LEVEL TROUGH STILL WELL TO
THE WEST AND POTENTIAL FOR A WEAK SFC WAVE ALONG THE FRONT TO SLOW
ITS PROGRESS EVEN FURTHER...WILL HAVE LIKELY POP TO START ACROSS SE
CT AND ERN LONG ISLAND AND CHANCE ELSEWHERE...WITH CHANCES GRADUALLY
RAMPING DOWN DURING THE AFTERNOON AND EARLY EVENING. CONDS LOOK
MAINLY DRY FOR LATER THU NIGHT AND MORE SO INTO FRI AS HIGH PRESSURE
BUILDS FROM THE WEST.
THE HIGH SHOULD WEAKEN ON SAT AS FLOW ALOFT BECOMES MORE ZONAL.
AS LOW TO MID LEVEL MOISTURE RETURN COMMENCES...WITH PRECIP
EFFICIENCY INCREASING BACK TO OVER 1 INCH BY LATE DAY...AND AS MID
LEVEL SHORTWAVES APPROACH IN ZONAL FLOW...SHOULD START TO SEE
INCREASING CHANCES FOR SHOWERS/TSTMS BEGINNING LATE DAY SAT INTO
SAT NIGHT.
THE FLOW ALOFT SHOULD UNDERGO SIGNIFICANT AMPLIFICATION EARLY NEXT
WEEK AS AN UPPER RIDGE BUILDS IN THE WESTERN STATES AND A POTENT
SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA MERGES WITH AN UPPER
LOW OVER QUEBEC...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE
EASTERN STATES. THERE WILL BE GOOD CHANCES FOR SHOWERS/TSTMS...
ESPECIALLY SUNDAY NIGHT INTO MON MORNING AS AN ASSOCIATED WAVE OF
LOW PRESSURE PASSES JUST OFF TO THE SE...THEN LATE DAY MON INTO MON
NIGHT WITH THE APPROACH OF A COLD FRONT FROM THE WEST.
COULD SEE SOME LEFTOVER SHOWERS/TSTMS ON TUE MAINLY IN THE MORNING
AS THE COLD FRONT MOVES TO THE EAST...THEN DRIER AND SLIGHTLY COOLER
AIR ARRIVING THROUGH THE REST OF TUE INTO TUE NIGHT.
&&
.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH
OF THE TAF PERIOD.
SEA BREEZE HAVE MOVED ACROSS MOST TERMINALS. KEWR IS THE EXCEPTION
LATE THIS AFTERNOON. WINDS DIMINISH TONIGHT...WITH MOST SPOTS
BECOMING LIGHT AND VARIABLE. SPEEDS INCREASE ONCE AGAIN ON
WEDNESDAY.
THERE IS A CHANCE OF PATCHY FOG TONIGHT. HAVE INCLUDED SOME
TEMPOS FOR REDUCED VSBYS AFTER 08Z.
...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)
KJFK FCSTER COMMENTS: STRONG SOUTH SEA BREEZE LIGHTENS AFTER SUNSET.
KLGA FCSTER COMMENTS: GUSTS BECOME LESS FREQUENT AS WINDS LIGHTEN
AFTER SUNSET.
KEWR FCSTER COMMENTS: SEA BREEZE SHOULD REMAIN JUST TO THE EAST OF
THE AIRPORT. LOW CONFIDENCE IN SEABREEZE MOVING THROUGH RESULTING
IN A WIND SHIFT.
KTEB FCSTER COMMENTS: SOUTH WINDS LIGHTEN AS THEY TURN TO THE SOUTHWEST.
KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE
SEE TERMINAL FORECAST FOR DETAILS.
KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. PLEASE
SEE TERMINAL FORECAST FOR DETAILS.
.OUTLOOK FOR 18Z WED THROUGH SUN...
.WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE.
.WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN
SCT-NUMEROUS SHOWERS/TSTMS.
.THU NIGHT-SAT...VFR.
.SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE.
&&
.MARINE...
THE LOCAL ENHANCED SEA BREEZE IS RESULTING IN 15-20 KT WINDS
ACROSS NY HARBOR AND THE WESTERN OCEAN WATERS. NOT EXPECTING 25 KT
GUSTS...SO WILL NOT HOIST A BRIEF SMALL CRAFT ADVISORY.
OTHERWISE...SUB-SCA CONDS EXPECTED THROUGH TONIGHT. PATCHY FOG
WILL DEVELOP ON THE WATERS TONIGHT...REDUCING VSBY TO AS LOW AS 1
NM.
WINDS WILL INCREASE TO 15-20 KT ONCE AGAIN ON THE OCEAN WATERS
WEDNESDAY AFTERNOON AND TO 10-15 KT WITH 15-20 KT GUSTS ON THE
REST OF THE WATERS AHEAD OF AN APPROACHING COLD FRONT. CONVECTION
LIKELY WEDNESDAY NIGHT. SEAS WILL AVERAGE 2-4 FT ON THE OCEAN AND
AROUND 1 FT ELSEWHERE.
OUTSIDE OF TSTMS THU AND LATE DAY SAT HAVE HIGH CONFIDENCE IN
QUIET CONDS THU THROUGH SAT...THEN FCST UNCERTAINTY CREEPS IN
BEGINNING ON SUNDAY. HAVE FCST CONTINUED QUIET CONDS...BUT IF AN
APPROACHING WAVE OF LOW PRESSURE AND/OR FRONTAL SYSTEM ARE
STRONGER THAN FCST...HAZARDOUS OCEAN SEAS COULD DEVELOP IF
CORRESPONDING S-SW FLOW IS STRONGER THAN FCST.
&&
.HYDROLOGY...
THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE
WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON
WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY
STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL
COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE
AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN
THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT
IN THE HAZARDOUS WEATHER OUTLOOK.
LOW PRESSURE PASSING JUST OFF TO THE SE SUNDAY NIGHT INTO MON
MORNING...FOLLOWED BY A COLD FRONTAL PASSAGE LATER MON...HAVE SOME
POTENTIAL TO PRODUCE HEAVY RAIN...AS PRECIP EFFICIENCY INCREASES
TO OVER 1.5 INCHES. THIS WILL DEPEND FIRST ON THE LOW TRACK...THEN
ON POTENTIAL FOR TRAINING OF CELLS AHEAD OF THE COLD FRONT...AS
WELL AS OTHER MESOSCALE/THERMODYNAMIC FACTORS. GIVEN THESE
UNCERTAINTIES IT IS TOO EARLY TO OUTLOOK THIS IN THE HWO.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/MPS
NEAR TERM...MPS
SHORT TERM...MPS
LONG TERM...GOODMAN
AVIATION...BC/PW
MARINE...GOODMAN/MPS
HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
345 PM EDT TUE JUL 22 2014
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE AS A COLD FRONT
APPROACHES FROM THE WEST. THE FRONT WILL MOVE ACROSS FROM
WEDNESDAY NIGHT INTO THURSDAY...FOLLOWED BY BUILDING HIGH PRESSURE
ON FRIDAY. THE HIGH WILL WEAKEN ON SATURDAY...THEN LOW PRESSURE
PASSING TO THE SOUTHEAST WILL IMPACT THE AREA SUNDAY INTO MONDAY.
AN ASSOCIATED COLD FRONT WILL APPROACH LATE DAY MONDAY...AND MOVE
ACROSS MONDAY NIGHT INTO TUESDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
SOME WEAK UPPER LEVEL ENERGY WILL SPILL OVER THE TOP OF THE RIDGE
ALONG THE NORTHEAST THIS EVENING. SOME WIDELY ISOLATED SHOWERS AND
POSSIBLE THUNDERSTORMS MAY DEVELOP EARLY IN THE EVENING HOURS...
MAINLY NORTH AND WEST OF NYC. WILL CAP POPS AT 20 PERCENT...AS NOT
EXPECTING MANY...IF ANY...STORMS. LATEST HRRR GUIDANCE CONTINUES
TO INDICATE SOME SHOWERS...MAINLY WEST OF THE HUDSON RIVER AND
INTO INTERIOR PORTIONS OF SW CT. ANY SHOWERS THAT DEVELOP WILL END
BETWEEN 9-10 PM.
WARM AND HUMID NIGHT ON TAP WITH LOWS IN THE 60S TO LOW 70S. THE
WARMEST TEMPS WILL OCCUR IN/AROUND NYC DUE TO THE URBAN HEAT
ISLAND EFFECT. SFC DEW POINTS WILL CLIMB THROUGH THE MID 60S AND
INTO THE UPPER 60S. CAN EXPECT PATCHY FOG TO DEVELOP AWAY FROM THE
CITY.
THERE IS A MODERATE RISK OF RIP CURRENTS INTO THIS EVENING WITH
ENHANCED SEA BREEZE DEVELOPMENT AND LONG PERIOD SE SWELLS.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
HOT AND INCREASINGLY HUMID AIR MASS REMAINS OVER THE AREA
WEDNESDAY. WITH HIGH PRES DEPARTING AND COLD FRONT APPROACHING
FROM THE WEST...SW FLOW INCREASES THROUGHOUT THE DAY...AND SFC
DEWPOINTS WILL RISE THROUGH THE 60S AND INTO THE LOWER 70S. MAX
TEMPS ON WEDNESDAY WILL TOP OFF IN THE LOWER 90S ACROSS NYC AND NE
NJ...AND WILL BE IN THE UPPER 80S TO NEAR 90 ELSEWHERE. TEMPS WILL
BE SIGHTLY COOLER NEAR THE COASTS. THE HEAT INDEX ON WEDNESDAY
WILL GENERALLY TOP OFF IN THE LOW TO MID 90S...EXPECT FOR NYC/NE
NJ...WHERE THE HEAT INDEX WILL BE IN THE MID TO UPPER 90S. SINCE
THE HEAT INDEX IN NYC WILL NOT REACH 95 FOR 2 CONSECUTIVE
DAYS...AND SINCE THE HEAT INDEX WILL REMAIN BELOW 100 ACROSS THE
CWA...WILL NOT ISSUE A HEAT ADVISORY.
AS COLD FRONT APPROACHES...SHOWERS AND THUNDERSTORMS WILL DEVELOP
NORTH AND WEST OF NYC IN THE AFTERNOON ALONG A PRE-FRONTAL TROUGH.
SHOWERS AND THUNDERSTORMS SPREAD EAST WEDNESDAY EVENING AND
WEDNESDAY NIGHT...AND THE BULK OF THE ACTIVITY SHOULD HOLD OFF
UNTIL WEDNESDAY NIGHT AS THE COLD FRONT PASSES THROUGH THE REGION.
WITH THE HEAT AND HUMIDITY...ML MUCAPE VALUES WILL RANGE FROM
1000-1500 J/KG DURING THE DAY...AND THEN WILL DROP TO AROUND 400
J/KG AT NIGHT WITH THE LOSS OF THE HEATING. 0-6 KM BULK SHEAR WILL
BE WEAK DURING THE DAY...AND THEN WILL RISE TO 25-35 KT AFTER 00Z
THURSDAY. CANNOT RULE OUT STRONG WINDS WITH ANY THUNDERSTORMS...
BUT PRIMARY THREAT WILL BE HEAVY RAIN DUE TO PWATS AROUND 2".
FLASH FLOODING OF LOW LYING AND POOR DRAINAGE AREAS IS POSSIBLE.
WILL NOT ISSUE A HAZARDOUS WEATHER OUTLOOK AS THE THREAT WILL NOT
BE WIDESPREAD.
SHOWERS AND THUNDERSTORMS TAPER OFF FROM WEST TO EAST WEDNESDAY
NIGHT AS THE COLD FRONT WORKS ITS WAY ACROSS THE REGION.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
THE SFC COLD FRONT SHOULD BE TO THE EAST THU MORNING...BUT WITH THE
H8 FRONT STILL YET TO MOVE ACROSS...A MID LEVEL TROUGH STILL WELL TO
THE WEST AND POTENTIAL FOR A WEAK SFC WAVE ALONG THE FRONT TO SLOW
ITS PROGRESS EVEN FURTHER...WILL HAVE LIKELY POP TO START ACROSS SE
CT AND ERN LONG ISLAND AND CHANCE ELSEWHERE...WITH CHANCES GRADUALLY
RAMPING DOWN DURING THE AFTERNOON AND EARLY EVENING. CONDS LOOK
MAINLY DRY FOR LATER THU NIGHT AND MORE SO INTO FRI AS HIGH PRESSURE
BUILDS FROM THE WEST.
THE HIGH SHOULD WEAKEN ON SAT AS FLOW ALOFT BECOMES MORE ZONAL.
AS LOW TO MID LEVEL MOISTURE RETURN COMMENCES...WITH PRECIP
EFFICIENCY INCREASING BACK TO OVER 1 INCH BY LATE DAY...AND AS MID
LEVEL SHORTWAVES APPROACH IN ZONAL FLOW...SHOULD START TO SEE
INCREASING CHANCES FOR SHOWERS/TSTMS BEGINNING LATE DAY SAT INTO
SAT NIGHT.
THE FLOW ALOFT SHOULD UNDERGO SIGNIFICANT AMPLIFICATION EARLY NEXT
WEEK AS AN UPPER RIDGE BUILDS IN THE WESTERN STATES AND A POTENT
SHORTWAVE TROUGH DIVING OUT OF CENTRAL CANADA MERGES WITH AN UPPER
LOW OVER QUEBEC...CARVING OUT A DEEP LONGWAVE TROUGH OVER THE
EASTERN STATES. THERE WILL BE GOOD CHANCES FOR SHOWERS/TSTMS...
ESPECIALLY SUNDAY NIGHT INTO MON MORNING AS AN ASSOCIATED WAVE OF
LOW PRESSURE PASSES JUST OFF TO THE SE...THEN LATE DAY MON INTO MON
NIGHT WITH THE APPROACH OF A COLD FRONT FROM THE WEST.
COULD SEE SOME LEFTOVER SHOWERS/TSTMS ON TUE MAINLY IN THE MORNING
AS THE COLD FRONT MOVES TO THE EAST...THEN DRIER AND SLIGHTLY COOLER
AIR ARRIVING THROUGH THE REST OF TUE INTO TUE NIGHT.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH
OF THE TAF PERIOD.
SEA BREEZE HAVE DEVELOPED THIS AFTERNOON AT KJFK/LGA. THE SEA BREEZE
SHOULD REACH KEWR BY 21Z. THIS WILL RESULT IN WIND DIRECTION AROUND
170-180 TRUE BY LATE AFTERNOON. WINDS DIMINISH TONIGHT...WITH MOST
SPOTS BECOMING LIGHT AND VARIABLE. SPEEDS INCREASE ONCE AGAIN ON
WEDNESDAY.
THERE IS A CHANCE OF SOME PATCHY FOG TONIGHT. HAVE INCLUDED SOME
TEMPOS FOR REDUCE VSBYS AFTER 08Z.
...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)
KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
GUSTS MAY BE OCCASIONAL THIS AFTERNOON.
KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER
TO 220 TRUE.
KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY
CLOSER TO 220 TRUE.
KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
GUSTS MAY BE OCCASIONAL.
.OUTLOOK FOR 18Z WED THROUGH SUN...
.WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE.
.WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN
SCT-NUMEROUS SHOWERS/TSTMS.
.THU NIGHT-SAT...VFR.
.SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE.
&&
.MARINE...
THE LOCAL ENHANCED SEA BREEZE IS RESULTING IN 15-20 KT WINDS
ACROSS NY HARBOR AND THE WESTERN OCEAN WATERS. NOT EXPECTING 25 KT
GUSTS...SO WILL NOT HOIST A BRIEF SMALL CRAFT ADVISORY.
OTHERWISE...SUB-SCA CONDS EXPECTED THROUGH TONIGHT. PATCHY FOG
WILL DEVELOP ON THE WATERS TONIGHT...REDUCING VSBY TO AS LOW AS 1
NM.
WINDS WILL INCREASE TO 15-20 KT ONCE AGAIN ON THE OCEAN WATERS
WEDNESDAY AFTERNOON AND TO 10-15 KT WITH 15-20 KT GUSTS ON THE
REST OF THE WATERS AHEAD OF AN APPROACHING COLD FRONT. CONVECTION
LIKELY WEDNESDAY NIGHT. SEAS WILL AVERAGE 2-4 FT ON THE OCEAN AND
AROUND 1 FT ELSEWHERE.
OUTSIDE OF TSTMS THU AND LATE DAY SAT HAVE HIGH CONFIDENCE IN
QUIET CONDS THU THROUGH SAT...THEN FCST UNCERTAINTY CREEPS IN
BEGINNING ON SUNDAY. HAVE FCST CONTINUED QUIET CONDS...BUT IF AN
APPROACHING WAVE OF LOW PRESSURE AND/OR FRONTAL SYSTEM ARE
STRONGER THAN FCST...HAZARDOUS OCEAN SEAS COULD DEVELOP IF
CORRESPONDING S-SW FLOW IS STRONGER THAN FCST.
&&
.HYDROLOGY...
THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE
WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON
WEDNESDAY NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY
STRONGER CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL
COULD EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE
AREA...AND POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN
THE LATTER IS CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT
IN THE HAZARDOUS WEATHER OUTLOOK.
LOW PRESSURE PASSING JUST OFF TO THE SE SUNDAY NIGHT INTO MON
MORNING...FOLLOWED BY A COLD FRONTAL PASSAGE LATER MON...HAVE SOME
POTENTIAL TO PRODUCE HEAVY RAIN...AS PRECIP EFFICIENCY INCREASES
TO OVER 1.5 INCHES. THIS WILL DEPEND FIRST ON THE LOW TRACK...THEN
ON POTENTIAL FOR TRAINING OF CELLS AHEAD OF THE COLD FRONT...AS
WELL AS OTHER MESOSCALE/THERMODYNAMIC FACTORS. GIVEN THESE
UNCERTAINTIES IT IS TOO EARLY TO OUTLOOK THIS IN THE HWO.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GOODMAN/MPS
NEAR TERM...MPS
SHORT TERM...MPS
LONG TERM...GOODMAN
AVIATION...BC
MARINE...GOODMAN/MPS
HYDROLOGY...GOODMAN/MPS
AREA FORECAST DISCUSSION
NWS NEW YORK NY
135 PM EDT TUE JUL 22 2014
.SYNOPSIS...
AS A HIGH PRESSURE SYSTEM MOVES SLOWLY EAST OF THE AREA TODAY...A
COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY. THE COLD FRONT
CROSSES THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY
MORNING...FOLLOWED BY HIGH PRESSURE BUILDING TO THE SOUTH OF LONG
ISLAND INTO SATURDAY. A STORM SYSTEM THEN IMPACTS THE AREA INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL CUT AFTERNOON POPS DOWN FROM LOW CHANCE TO SLIGHT CHANCE AND
CAP POPS AT 20 PERCENT. LATEST HRRR INDICATING ONLY SPOTTY
SHOWERS...AND 12Z NAM DOES NOT HAVE MORE THAN ISOLATED COVERAGE AT
BEST.
SEA BREEZES CONTINUE TO WORK THEIR WAY NORTH THROUGH THE REGION.
WIND SPEEDS WILL BE 10 KT OR LESS. TEMPS ACROSS LONG ISLAND AND
COASTAL CT WILL EITHER HOLD STEADY OR ONLY SLOWLY WARM THROUGH THE
REST OF THE AFTERNOON.
OTHERWISE...SKIES WILL BE SUNNY WITH TEMPS A FEW DEGREES ABOVE
NORMAL...TOPPING OFF IN THE MID TO UPPER 80S...POSSIBLY AROUND 90
WEST OF THE HUDSON RIVER.
THERE IS A MODERATE RISK OF RIP CURRENTS...MAINLY THIS AFTERNOON
THROUGH EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG
PERIOD SE SWELLS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...SW WINDS WILL CONTINUE TRANSPORTING HIGHER DEW POINTS
ACROSS THE REGION MAKING IT FEEL UNCOMFORTABLE.
WEDNESDAY...SUMMER HEAT AND HUMIDITY RETURNS WITH DAY TIME HIGH
TEMPS REACHING AROUND 90 ACROSS NYC AND URBAN NORTHEAST NJ AND
WITH HEAT INDEX VALUES RISING INTO THE MID AND UPPER 90S. NO
EXTENDED HEAT WAVE IS FORECAST AS THE NEXT COLD FRONT APPROACHES.
A WARM MOIST UNSTABLE MARITIME TROPICAL AIR MASS WILL SET THE
STAGE FOR THE DEVELOPMENT OF MORE NUMEROUS SHOWERS AND TSTMS BY
WED AFTERNOON MAINLY WEST AND NORTH OF NYC. INCREASED POPS TO
LIKELY CATEGORY BY 6 PM.
PRIMARY POTENTIAL HAZARD IS HEAVY RAIN WHICH COULD CAUSE ISOLATED
FLASH FLOODING MAINLY OF LOW LYING POOR DRAINAGE AREAS. CAN NOT
RULE OUT THE POTENTIAL FOR A STRONG TO POSSIBLY SEVERE TSTM WITH
DAMAGING WINDS BEING THE PRIMARY THREAT.
BECAUSE MORE WIDESPREAD FLASH FLOODING OR SEVERE STORMS ARE NOT
FORECAST...A HAZARDOUS WEATHER OUTLOOK WILL NOT BE ISSUED AT THIS
TIME FOR THESE POTENTIAL HAZARDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HAVE THE POTENTIAL FOR SIGNIFICANT CONVECTION WEDNESDAY
NIGHT...WITH THE PASSAGE OF A SURFACE COLD FRONT THROUGH A RATHER
WARM AND HUMID AIR MASS. THERE ARE SOME INDICATIONS THAT CAPES OF
1000-1500 J/KG COULD PERSIST AT LEAST THROUGH WEDNESDAY
EVENING...AND SHOWALTER INDICES OF 0 TO -2 PERSIST THROUGH THE
NIGHT...ESPECIALLY OVER EASTERN PORTIONS. THIS COUPLED WITH THE
REGION AT THE MINIMUM INT HE RIGHT REAR QUADRANT OF A 80+ KT UPPER
LEVEL JET...AND POSSIBLY IN A COUPLED UPPER JET REGION - DEPENDING
ON THE EXACT LOCATION OF THE SUBTROPICAL JET. MODELS DUE VARY ON
THE LOCATION/STRENGTH OF THE LATTER. 0-6 KM BULK SHEAR IS FORECAST
TO INCREASE TO 25-35 KT DURING THE EVENING SO THERE COULD BE
SUFFICIENT SHEAR/CAPE FOR ISOLATED SUPER CELLS DURING THE EVENING
MAINLY ACROSS NYC/NE NJ/S CT/LOWER HUDSON VALLEY ZONES. AS SUCH
THERE IS THE POTENTIAL FOR STRONG TO POSSIBLY SEVERE STORMS
WEDNESDAY NIGHT...MAINLY PRIOR TO 6Z.
MODELS DO DIFFER ON AMOUNT/EXTENT OF PRECIPITATION ON THURSDAY DUE
TO DIFFERENCES IN TIMING OF 850 HPA COLD FRONT. NAM/SREF ARE THE
SLOWEST WITH THIS FEATURE. GIVEN THE PROPENSITY FOR COLD FRONTS TO
HANG UP CROSSING THE MOUNTAINS...SLOWER PROGRESSION OF THE 850 COLD
FRONT MAKES SOME SENSE...SO DID WEIGH POPS AND CONVECTIVE
PROBABILITIES MORE TOWARDS THIS LINE OF THINKING. HOWEVER...THERE
SHOULD NOT BE ENOUGH INSTABILITY FOR ANY STRONG OR SEVERE STORMS ON
THURSDAY. HAVE LINGERED SLIGHT CHANCE POPS INTO THURSDAY EVENING
ACROSS FAR SE ZONES...THIS MIGHT BE A TAD TOO LONG ULTIMATELY...BUT
WITH OVERALL TREND WITH FRONTAL TIMING A TAD SLOWER THAN PREVIOUS
FORECAST...CANNOT RULE OUT PRECIPITATION LASTING A TAD LONGER THAN
CURRENTLY EXPECTED.
SEE THE HYDROLOGY SECTION OF THE AFD FOR RAINFALL AMOUNTS AND
POTENTIAL IMPACTS FROM TONIGHT INTO THURSDAY.
FOR LOWS WEDNESDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES THEN ADDED A DEGREE TO WEIGH TOWARDS WARMER
SOLUTIONS - WITH VALUES FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 950-875 HPA PER
BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET GUIDANCE...THEN ADDED 2 DEGREES TO WEIGH TOWARDS WARMER
SOLUTIONS. EXPECT HIGHS TO BE AROUND A FEW DEGREES BELOW NORMAL. FOR
LOWS THURSDAY NIGHT USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE
WITH NAM 2-METER TEMPERATURES - WITH VALUES A FEW DEGREES BELOW
NORMAL.
THE REGIONS WEATHER FRIDAY-MONDAY WILL LARGELY BE DETERMINED BY THE
EXACT POSITION/STRENGTH OF A RATHER LARGE CUTOFF LOW OVER EASTERN
CANADA...AND WHEN SPOKES OF ENERGY ROTATING AROUND ITS BASE PASS
THROUGH THE REGION. FOR NOW...IT APPEARS THE REGION SHOULD BE
BETWEEN SPOKES FRIDAY AND FRIDAY NIGHT AND POSSIBLY INTO SATURDAY.
SO FOR NOW HAVE GONE WITH A DRY FORECAST FROM FRIDAY-SATURDAY NIGHT.
HOWEVER...THERE ARE SOME INDICATIONS THAT A SMALL SHORTWAVE COULD
PASS THE AREA ON SATURDAY...POSSIBLY TRIGGERING SOME -SHRA ON
SATURDAY. CONFIDENCE IN THIS IS TOO LOW TO REFLECT IN THE FORECAST
AT THIS TIME.
BASED ON MODEL CONSENSUS...AM MORE CONFIDENT IN A PERIOD OF
UNSETTLED WEATHER SUNDAY...SUNDAY NIGHT AND MONDAY. IT WILL NOT RAIN
THE ENTIRE TIME...IN FACT MOST AREAS WILL BE DRY FOR MORE TIME
DURING THIS TIME FRAME THAN IT WILL RAIN AT ANY GIVEN LOCATION.
GIVEN DIFFICULTY IN TIMING OF SHORTWAVE ROTATING AROUND A CUTOFF LOW
THIS FAR OUT...YET ALONE INHERENT UNCERTAINTY IN MODELS HANDLING OF
A CUTOFF LOW THIS FAR OUT...DO NOT WANT TO EVEN ATTEMPT ANY SORT OF
TIMING - SO HAVE CHANCE POPS SUNDAY-MONDAY.
FOR TEMPERATURES FRIDAY-MONDAY USED A BLEND OF MEX/EKD/ECE/ECM/WPC
GUIDANCE WITH HIGHS RUNNING BELOW NORMAL...AND LOWS STARTING OUT
BELOW NORMAL AND TRENDING TO NEAR NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE CONTINUES TO SLOWLY MOVE OFFSHORE. VFR THROUGH MUCH
OF THE TAF PERIOD.
SEA BREEZE EXPECTED TO DEVELOP THIS AFTERNOON. TIMING COULD BE
OFF +/- 1-2 HOURS FROM TAF. MEDIUM CONFIDENCE SEA BREEZE MAKES IT
TO KEWR/KTEB...RESULTING IN WIND DIR AROUND 170-180 TRUE BY LATE
AFTERNOON.
A SHRA POSSIBLE ACROSS INTERIOR THIS AFTERNOON INTO EARLY
EVENING. CONFIDENCE FAIRLY LOW THOUGH...SO ONLY VCSH AT KSWF.
...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)
KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER
TO 220 TRUE.
KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY
CLOSER TO 220 TRUE.
KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
.OUTLOOK FOR 18Z WED THROUGH SUN...
.WED AFTERNOON...PRIMARILY VFR. ISOLATED SHRA/TSTM LATE.
.WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN
SCT-NUMEROUS SHOWERS/TSTMS.
.THU NIGHT-SAT...VFR.
.SUN...CHANCE OF SHOWERS OR THUNDERSTORMS. SUB-VFR POSSIBLE.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS OF 25 KT AND 5 FT THROUGH WEDNESDAY MORNING. OCCASIONAL
GUSTS TO 25 KT ARE POSSIBLE ON MAINLY THE OCEAN WATERS WEDNESDAY
AFTERNOON.
SUSTAINED WINDS UP TO 15 KT ARE LIKELY WEDNESDAY NIGHT AHEAD OF A
COLD FRONT. FOR NOW APPEARS GUSTS AND SEAS SHOULD STAY BELOW SMALL
CRAFT THRESHOLDS. THE PRESSURE GRADIENT THEN RELAXES OVER THE REGION
THURSDAY AND REMAINS LIGHT INTO SATURDAY. AS A RESULT EXPECT WINDS
OF 10 KT OR LESS FROM THURSDAY THROUGH SATURDAY...WITH SEAS 4 FT OR
LESS ON THE COASTAL OCEAN WATERS AND 1 FT OR LESS ELSEWHERE.
&&
.HYDROLOGY...
MAINLY DRY THROUGH WEDNESDAY MORNING...THOUGH A BRIEF LOCALLY
HEAVY DOWNPOUR IS POSSIBLE IN ANY STRONGER CONVECTION THIS
AFTERNOON. THIS BEST CHANCE FOR THIS IS TO THE N/W OF NYC.
THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE
WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY
NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER
CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD
EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND
POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS
CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GC/MALOIT
NEAR TERM...GC/MALOIT/MPS
SHORT TERM...GC
LONG TERM...MALOIT
AVIATION...BC
MARINE...GC/MALOIT
HYDROLOGY...GC/MALOIT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1228 PM EDT TUE JUL 22 2014
.SYNOPSIS...
AS A HIGH PRESSURE SYSTEM MOVES SLOWLY EAST OF THE AREA TODAY...A
COLD FRONT WILL APPROACH FROM THE WEST ON WEDNESDAY. THE COLD FRONT
CROSSES THE AREA FROM WEDNESDAY NIGHT INTO THURSDAY
MORNING...FOLLOWED BY HIGH PRESSURE BUILDING TO THE SOUTH OF LONG
ISLAND INTO SATURDAY. A STORM SYSTEM THEN IMPACTS THE AREA INTO
EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WILL CUT AFTERNOON POPS DOWN FROM LOW CHANCE TO SLIGHT CHANCE AND
CAP POPS AT 20 PERCENT. LATEST HRRR INDICATING ONLY SPOTTY
SHOWERS...AND 12Z NAM DOES NOT HAVE MORE THAN ISOLATED COVERAGE AT
BEST.
SEA BREEZES CONTINUE TO WORK THEIR WAY NORTH THROUGH THE REGION.
WIND SPEEDS WILL BE 10 KT OR LESS. TEMPS ACROSS LONG ISLAND AND
COASTAL CT WILL EITHER HOLD STEADY OR ONLY SLOWLY WARM THROUGH THE
REST OF THE AFTERNOON.
OTHERWISE...SKIES WILL BE SUNNY WITH TEMPS A FEW DEGREES ABOVE
NORMAL...TOPPING OFF IN THE MID TO UPPER 80S...POSSIBLY AROUND 90
WEST OF THE HUDSON RIVER.
THERE IS A MODERATE RISK OF RIP CURRENTS...MAINLY THIS AFTERNOON
THROUGH EVENING WITH ENHANCED SEA BREEZE DEVELOPMENT AND LONG
PERIOD SE SWELLS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
TONIGHT...SW WINDS WILL CONTINUE TRANSPORTING HIGHER DEW POINTS
ACROSS THE REGION MAKING IT FEEL UNCOMFORTABLE.
WEDNESDAY...SUMMER HEAT AND HUMIDITY RETURNS WITH DAY TIME HIGH
TEMPS REACHING AROUND 90 ACROSS NYC AND URBAN NORTHEAST NJ AND
WITH HEAT INDEX VALUES RISING INTO THE MID AND UPPER 90S. NO
EXTENDED HEAT WAVE IS FORECAST AS THE NEXT COLD FRONT APPROACHES.
A WARM MOIST UNSTABLE MARITIME TROPICAL AIR MASS WILL SET THE
STAGE FOR THE DEVELOPMENT OF MORE NUMEROUS SHOWERS AND TSTMS BY
WED AFTERNOON MAINLY WEST AND NORTH OF NYC. INCREASED POPS TO
LIKELY CATEGORY BY 6 PM.
PRIMARY POTENTIAL HAZARD IS HEAVY RAIN WHICH COULD CAUSE ISOLATED
FLASH FLOODING MAINLY OF LOW LYING POOR DRAINAGE AREAS. CAN NOT
RULE OUT THE POTENTIAL FOR A STRONG TO POSSIBLY SEVERE TSTM WITH
DAMAGING WINDS BEING THE PRIMARY THREAT.
BECAUSE MORE WIDESPREAD FLASH FLOODING OR SEVERE STORMS ARE NOT
FORECAST...A HAZARDOUS WEATHER OUTLOOK WILL NOT BE ISSUED AT THIS
TIME FOR THESE POTENTIAL HAZARDS.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HAVE THE POTENTIAL FOR SIGNIFICANT CONVECTION WEDNESDAY
NIGHT...WITH THE PASSAGE OF A SURFACE COLD FRONT THROUGH A RATHER
WARM AND HUMID AIR MASS. THERE ARE SOME INDICATIONS THAT CAPES OF
1000-1500 J/KG COULD PERSIST AT LEAST THROUGH WEDNESDAY
EVENING...AND SHOWALTER INDICES OF 0 TO -2 PERSIST THROUGH THE
NIGHT...ESPECIALLY OVER EASTERN PORTIONS. THIS COUPLED WITH THE
REGION AT THE MINIMUM INT HE RIGHT REAR QUADRANT OF A 80+ KT UPPER
LEVEL JET...AND POSSIBLY IN A COUPLED UPPER JET REGION - DEPENDING
ON THE EXACT LOCATION OF THE SUBTROPICAL JET. MODELS DUE VARY ON
THE LOCATION/STRENGTH OF THE LATTER. 0-6 KM BULK SHEAR IS FORECAST
TO INCREASE TO 25-35 KT DURING THE EVENING SO THERE COULD BE
SUFFICIENT SHEAR/CAPE FOR ISOLATED SUPER CELLS DURING THE EVENING
MAINLY ACROSS NYC/NE NJ/S CT/LOWER HUDSON VALLEY ZONES. AS SUCH
THERE IS THE POTENTIAL FOR STRONG TO POSSIBLY SEVERE STORMS
WEDNESDAY NIGHT...MAINLY PRIOR TO 6Z.
MODELS DO DIFFER ON AMOUNT/EXTENT OF PRECIPITATION ON THURSDAY DUE
TO DIFFERENCES IN TIMING OF 850 HPA COLD FRONT. NAM/SREF ARE THE
SLOWEST WITH THIS FEATURE. GIVEN THE PROPENSITY FOR COLD FRONTS TO
HANG UP CROSSING THE MOUNTAINS...SLOWER PROGRESSION OF THE 850 COLD
FRONT MAKES SOME SENSE...SO DID WEIGH POPS AND CONVECTIVE
PROBABILITIES MORE TOWARDS THIS LINE OF THINKING. HOWEVER...THERE
SHOULD NOT BE ENOUGH INSTABILITY FOR ANY STRONG OR SEVERE STORMS ON
THURSDAY. HAVE LINGERED SLIGHT CHANCE POPS INTO THURSDAY EVENING
ACROSS FAR SE ZONES...THIS MIGHT BE A TAD TOO LONG ULTIMATELY...BUT
WITH OVERALL TREND WITH FRONTAL TIMING A TAD SLOWER THAN PREVIOUS
FORECAST...CANNOT RULE OUT PRECIPITATION LASTING A TAD LONGER THAN
CURRENTLY EXPECTED.
SEE THE HYDROLOGY SECTION OF THE AFD FOR RAINFALL AMOUNTS AND
POTENTIAL IMPACTS FROM TONIGHT INTO THURSDAY.
FOR LOWS WEDNESDAY NIGHT USED A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES THEN ADDED A DEGREE TO WEIGH TOWARDS WARMER
SOLUTIONS - WITH VALUES FORECAST TO BE A FEW DEGREES ABOVE NORMAL.
FOR HIGHS THURSDAY USED A BLEND OF MIXING DOWN FROM 950-875 HPA PER
BUFKIT SOUNDINGS...WITH NAM 2-METER TEMPERATURES AND A BLEND OF
MAV/MET GUIDANCE...THEN ADDED 2 DEGREES TO WEIGH TOWARDS WARMER
SOLUTIONS. EXPECT HIGHS TO BE AROUND A FEW DEGREES BELOW NORMAL. FOR
LOWS THURSDAY NIGHT USED A BLEND OF MEX/EKD/ECE/ECM/WPC GUIDANCE
WITH NAM 2-METER TEMPERATURES - WITH VALUES A FEW DEGREES BELOW
NORMAL.
THE REGIONS WEATHER FRIDAY-MONDAY WILL LARGELY BE DETERMINED BY THE
EXACT POSITION/STRENGTH OF A RATHER LARGE CUTOFF LOW OVER EASTERN
CANADA...AND WHEN SPOKES OF ENERGY ROTATING AROUND ITS BASE PASS
THROUGH THE REGION. FOR NOW...IT APPEARS THE REGION SHOULD BE
BETWEEN SPOKES FRIDAY AND FRIDAY NIGHT AND POSSIBLY INTO SATURDAY.
SO FOR NOW HAVE GONE WITH A DRY FORECAST FROM FRIDAY-SATURDAY NIGHT.
HOWEVER...THERE ARE SOME INDICATIONS THAT A SMALL SHORTWAVE COULD
PASS THE AREA ON SATURDAY...POSSIBLY TRIGGERING SOME -SHRA ON
SATURDAY. CONFIDENCE IN THIS IS TOO LOW TO REFLECT IN THE FORECAST
AT THIS TIME.
BASED ON MODEL CONSENSUS...AM MORE CONFIDENT IN A PERIOD OF
UNSETTLED WEATHER SUNDAY...SUNDAY NIGHT AND MONDAY. IT WILL NOT RAIN
THE ENTIRE TIME...IN FACT MOST AREAS WILL BE DRY FOR MORE TIME
DURING THIS TIME FRAME THAN IT WILL RAIN AT ANY GIVEN LOCATION.
GIVEN DIFFICULTY IN TIMING OF SHORTWAVE ROTATING AROUND A CUTOFF LOW
THIS FAR OUT...YET ALONE INHERENT UNCERTAINTY IN MODELS HANDLING OF
A CUTOFF LOW THIS FAR OUT...DO NOT WANT TO EVEN ATTEMPT ANY SORT OF
TIMING - SO HAVE CHANCE POPS SUNDAY-MONDAY.
FOR TEMPERATURES FRIDAY-MONDAY USED A BLEND OF MEX/EKD/ECE/ECM/WPC
GUIDANCE WITH HIGHS RUNNING BELOW NORMAL...AND LOWS STARTING OUT
BELOW NORMAL AND TRENDING TO NEAR NORMAL.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL SLOWLY MOVE OFFSHORE TODAY. VFR WITH LIGHT
W/SW FLOW THIS MORNING.
SEA BREEZE LATE THIS MORNING INTO AFTERNOON. TIMING COULD BE OFF +/-
1-2 HOURS FROM TAF. MEDIUM CONFIDENCE SEA BREEZE MAKES IT TO
KEWR/KTEB...RESULTING IN WIND DIR AROUND 170-180 TRUE BY LATE
AFTERNOON.
A SHRA POSSIBLE ACROSS INTERIOR LATE AFTERNOON INTO EARLY EVENING.
CONFIDENCE FAIRLY LOW THOUGH...SO ONLY VCSH AT KSWF.
...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)
KJFK FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
KLGA FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
GUSTS INDICATED IN TAF MAY BE MORE OCCASIONAL IN FREQUENCY.
KEWR FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER
TO 220 TRUE.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: MEDIUM CONFIDENCE IN SEA BREEZE REACHING
TERMINAL THIS AFTERNOON. IF IT DOES NOT...WIND DIR WILL STAY CLOSER
TO 220 TRUE.
KHPN FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 2 HOURS.
KISP FCSTER COMMENTS: TIMING OF SEA BREEZE MAY BE OFF +/- 1 HOUR.
.OUTLOOK FOR 12Z WED THROUGH SAT...
.WED...PRIMARILY VFR. BRIEF MVFR VSBY POSSIBLE EARLY WED...ESP
INTERIOR AND EASTERN TERMINALS. ISOLATED SHRA/TSTM NW OF THE NY
METRO LATE.
.WED NIGHT-THU...SLOW MOVING COLD FROPA. MVFR OR LOWER CONDS IN
SCT-NUMEROUS SHOWERS/TSTMS.
.THU NIGHT-SAT...VFR.
&&
.MARINE...
MADE MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
WINDS AND SEAS ARE FORECAST TO REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS OF 25 KT AND 5 FT THROUGH WEDNESDAY MORNING. OCCASIONAL
GUSTS TO 25 KT ARE POSSIBLE ON MAINLY THE OCEAN WATERS WEDNESDAY
AFTERNOON.
SUSTAINED WINDS UP TO 15 KT ARE LIKELY WEDNESDAY NIGHT AHEAD OF A
COLD FRONT. FOR NOW APPEARS GUSTS AND SEAS SHOULD STAY BELOW SMALL
CRAFT THRESHOLDS. THE PRESSURE GRADIENT THEN RELAXES OVER THE REGION
THURSDAY AND REMAINS LIGHT INTO SATURDAY. AS A RESULT EXPECT WINDS
OF 10 KT OR LESS FROM THURSDAY THROUGH SATURDAY...WITH SEAS 4 FT OR
LESS ON THE COASTAL OCEAN WATERS AND 1 FT OR LESS ELSEWHERE.
&&
.HYDROLOGY...
MAINLY DRY THROUGH WEDNESDAY MORNING...THOUGH A BRIEF LOCALLY
HEAVY DOWNPOUR IS POSSIBLE IN ANY STRONGER CONVECTION THIS
AFTERNOON. THIS BEST CHANCE FOR THIS IS TO THE N/W OF NYC.
THERE IS THE POTENTIAL FOR AROUND 1/2 INCH OF RAINFALL FROM LATE
WEDNESDAY THROUGH THURSDAY WITH LOCALLY HIGHER AMOUNTS POSSIBLE.
PRECIPITABLE WATERS ARE FORECAST TO BE AROUND 2 INCHES ON WEDNESDAY
NIGHT...SO LOCALLY HEAVY RAINFALL IS POSSIBLE IN ANY STRONGER
CONVECTION. AREAS EXPERIENCING LOCALLY HEAVY RAINFALL COULD
EXPERIENCE AT LEAST MINOR FLOODING OF URBAN/POOR DRAINAGE AREA...AND
POSSIBLY LOCALIZED FLASH FLOODING. THE CONFIDENCE IN THE LATTER IS
CURRENTLY LESS THAN 30 PERCENT SO WILL NOT HIGHLIGHT IN THE
HAZARDOUS WEATHER OUTLOOK.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GC/MALOIT
NEAR TERM...GC/MALOIT/MPS
SHORT TERM...GC
LONG TERM...MALOIT
AVIATION...BC/PICCA
MARINE...GC/MALOIT
HYDROLOGY...GC/MALOIT
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
950 AM EDT TUE JUL 22 2014
.DISCUSSION...
CURRENT-THIS AFTERNOON...
SHOWERS AND STORMS OVER THE GULF STREAM MOVING NORTH AND AWAY FROM
LAND. LATEST RUC SURFACE ANALYSIS AND 500MB PLOT SHOWS INVERTED
TROUGHING PATTERN OVER FLORIDA AND UNDER THE SOUTH TO SOUTHWEST FLOW
AHEAD OF THE UPPER LEVEL LOW OVER SOUTHERN ALABAMA.
VERY MOIST ATMOSPHERE WITH PRECIPITABLE WATER VALUES AROUND 2 INCHES
WILL CONTINUE TODAY. THE STRONGER MID LEVEL SUPPORT...VORTICITY...
IS NORTH OF CENTRAL FLORIDA THUS CONVECTION WILL BE BY SEA BREEZE
INITIATION AND BOUNDARIES INTERACTING WITH EACH OTHER IN THE
AFTERNOON AND LINGERING ON THROUGH THE EVENING.
WEAK STEERING FLOW WILL MEAN THAT STORMS WILL BE CAPABLE OF
PRODUCING HEAVY RAIN ALONG WITH GUSTY DOWN BURSTS WINDS AND CLOUD TO
GROUND LIGHTNING STRIKES. MID LEVEL TEMPERATURES OVER CENTRAL AND
NORTH FLORIDA PER THE 6AM AND 8AM SOUNDINGS WERE AROUND -6C WHILE TO
THE NORTH...TALLAHASSEE AND TO THE SOUTH...KEY WEST... THE 500MB
TEMPERATURES WERE COOLER AT -8.5C AND -7.1C RESPECTIVELY. YESTERDAY
PROVED THAT SMALL HAIL MAY NOT BE RULED OUT EVEN WITH 500MB
TEMPERATURES IN THE -6C TO -7C RANGE.
NO SIGNIFICANT CHANGES PLANNED FOR THE MORNING ZONE UPDATE.
PREVIOUS ZONES DISCUSSION
TODAY-TONIGHT...CUT OFF LOW ALOFT ACROSS THE WESTERN FLORIDA
PANHANDLE WILL RETROGRADE SLIGHTLY TO THE MISSISSIPPI DELTA
REGION. THIS WILL ALLOW ATLANTIC RIDGE TO NUDGE WESTWARD TOWARDS
THE FLORIDA PENINSULA. A DEEP LAYER OF SOUTHERLY FLOW WILL DEVELOP
AS A RESULT...WHICH SHOULD LIFT A VERY WEAK LOW LEVEL TROUGH OUT TO
THE NORTH OR GRADUALLY WASH IT OUT. THIS WEAK TROUGH HAS BEEN
FOCUSING MOISTURE CONVERGENCE ALONG THE COAST EARLY THIS MORNING
WITH SCATTERED SHOWERS OCCURRING. THIS MAY CONTINUE FROM THE CAPE
NORTH INTO LATE MORNING.
THE DEEP SOUTHERLY FLOW WILL KEEP HIGH MOISTURE IN PLACE. THE GFS
SHOWS PRECIPITABLE WATER 2 INCHES OR GREATER. THIS SHOULD LEAD TO
A LITTLE EARLIER THAN NORMAL CONVECTIVE INITIATION ALONG THE EAST
COAST SEA BREEZE...DURING THE LATE MORNING OR EARLY AFTERNOON. A
LIGHT SOUTHWEST STEERING FLOW IS FORECAST WHICH MIGHT KEEP THE SEA
BREEZE CONVECTION NEAR THE COAST WELL INTO THE AFTERNOON. EXPECT
THAT OUTFLOW BOUNDARIES WILL PUSH INLAND DURING THE MID TO LATE
AFTERNOON AND STRONGER BOUNDARY INTERACTIONS SHOULD OCCUR ACROSS
THE INTERIOR COUNTIES. THEREFORE EXPECT BOTH COAST AND INLAND TO
GET A RATHER HEALTHY COVERAGE OF SHOWERS AND STORMS. MOS POPS ARE
50-60 PERCENT BUT WILL GO WITH LIKELY RAIN CHANCES AREAWIDE.
A FEW SHOWERS/STORMS MAY LINGER A LITTLE PAST SUNSET SO WILL MATCH
THE 20-30 PERCENT MOS POPS FOR THIS EVENING.
WED-THU...MID-LEVEL TROUGH OVER THE NORTH GOMEX WILL RETROGRADE
SLOWLY TOWARD THE SOUTHERN LOUISIANA COAST...THEN EVENTUALLY WILL
WEAKEN AND BECOME STRETCHED OUT NORTHEAST-SOUTHWEST FROM THE MID
ATLC STATES THROUGH THE TEXAS EAST COAST. MID-LEVEL RIDGING OVER THE
BAHAMAS/FLORIDA PENINSULA WILL GRADUALLY WEAKEN AND BECOME
SUPPRESSED SOUTHEASTWARD BY THE END OF THE PERIOD. DEEP LAYER
MOISTURE VALUES IN THE NEIGHBORHOOD OF TWO INCHES WILL BE COMMON.
THE PRESSURE GRADIENT AT THE SURFACE REMAINS WEAK WITH LIGHT WINDS
AND DAILY INLAND MOVING SEA BREEZES ON EITHER SIDE OF THE PENINSULA.
TEMPERATURES AT 500 MB ARE FORECAST TO BE RELATIVELY WARM FROM -6C
TO -7C BUT PARAMETERS WILL STILL BE PRESENT TO CONTINUE SLIGHTLY
ABOVE SEASONAL POP CHANCES IN THE 40 TO 50 PERCENT RANGE EACH
AFTERNOON/EARLY EVENING. STEERING FLOW FOR STORMS WILL REMAIN LIGHT
AND ERRATIC. THE MAIN THREATS FROM STORMS CONTINUE TO BE LOCALLY
HEAVY RAINFALL...FREQUENT LIGHTNING AND GUSTY WINDS. AFTERNOON HIGHS
IN THE UPPER 80S TO AROUND 90 DEGREES AT THE COAST WITH LOW TO MID
90S INLAND. HEAT INDICES WILL RANGE FROM 98F-103F EACH AFTERNOON.
OVERNIGHT LOWS IN THE LOW TO MID 70S.
FRI-MON...MID-LEVEL TROUGHING WILL ENCOMPASS THE EASTERN CONUS
DURING THIS TIME AS A LARGE RIDGE AMPLIFIES OVER THE WESTERN CONUS.
DEEP LAYER SOUTHWEST TO WEST-SOUTHWEST FLOW WILL BE DOMINANT THROUGH
THE PERIOD. SUFFICIENT MOISTURE...THE DAILY SEA BREEZE REGIME AND
VARIOUS OTHER AFTERNOON BOUNDARY COLLISIONS SHOULD ALLOW FOR A 40 TO
50 PERCENT CHANCE POP THROUGH THIS PERIOD. THE WESTERLY STEERING
FLOW...WHILE REMAINING LIGHT...WILL STILL PUSH STORMS TOWARDS THE
EAST COAST LATER IN THE DAY AND EVENING. SOME OF THESE STORMS WILL
MOVE OFF THE EAST COAST PRESENTING ISSUES FOR MARINERS. AFTERNOON
HIGHS AND OVERNIGHT LOWS IN LINE WITH NEAR SEASONAL CONDITIONS
THROUGH THE PERIOD.
&&
.AVIATION...
BRIEF...TOO SHORT EVEN FOR TEMPO...LOW CEILINGS IN THE LIGHT
SOUTHERLY FLOW UNTIL THE SLIGHTLY STRONGER WINDS ABOVE THE SURFACE
WORK THEIR WAY DOWN WITH DAYTIME HEATING. LOCAL WRF_ARW3 MODEL RUN
SUGGESTING MID TO LATE AFTERNOON...19Z-22Z...STORMS OVER THE
INTERIOR AND LITTLE EARLY AT THE COAST.
PREVIOUS AVIATION DISCUSSION
SCATTERED SHOWERS WITH IFR WILL AFFECT THE COAST EARLY THIS
MORNING BUT OTHERWISE VFR WILL OCCUR UNTIL SHOWERS/STORMS GET
GOING DURING THE LATE MORNING OR EARLY AFTERNOON ALONG THE EAST
COAST SEA BREEZE. THIS ACTIVITY MAY TEND TO LINGER NEAR THE COAST
WELL INTO THE AFTERNOON. THE STRONGEST BOUNDARY INTERACTIONS ARE
EXPECTED ACROSS THE INTERIOR DURING THE LATE AFTERNOON TO EARLY
EVENING. IN ADDITION TO ABOUT AN HOUR OF IFR IN HEAVY RAIN...A FEW
STORMS WILL AGAIN PRODUCE FREQUENT LIGHTNING STRIKES.
&&
.MARINE...
CURRENT-THIS AFTERNOON...
THE TWO NOAA BUOYS AT 20 AND 120NM OFFSHORE WERE RECORDING EAST TO
SOUTHEAST WINDS AROUND 5 KNOTS AND AROUND 15 KNOTS AND LONG PERIOD 3
TO 4 FOOT SEAS RESPECTIVELY. THE TWO SCRIPPS BUOYS AT 4 AND 6NM OFF
THE COAST WERE RECORDING 2 FOOT LONG PERIOD SEAS. SEA BREEZE MAY
BACK THE NEARSHORE WINDS MORE TO THE EAST DURING THE AFTERNOON.
MORNING UPDATE HAS NO SIGNIFICANT CHANGES.
PREVIOUS MARINE DISCUSSION
TODAY-TONIGHT...A SOUTHEAST BREEZE EARLY THIS MORNING IS FORECAST
TO VEER TO SOUTHERLY THROUGH THE DAY AND INTO TONIGHT. SPEEDS
LOOK TO BE 10 KNOTS OR LESS BUT REACHING 10-15 KNOTS OFFSHORE
TONIGHT. HIGH MOISTURE WILL RESULT IN SCATTERED NORTHWARD MOVING
SHOWERS AND STORMS THROUGH THE PERIOD.
WED-SAT...THE FAIRLY WEAK SURFACE PRESSURE GRADIENT CONTINUES EACH
DAY WITH FORECAST SEA BREEZE FORMATION AND MARCH INLAND EACH
AFTERNOON. WINDS AOB 10 KTS DURING THE DAYLIGHT PERIOD...EXCEPT NEAR
10-12 KTS NEAR THE COAST EACH AFTERNOON FOLLOWING SEA BREEZE
FORMATION. NOCTURNAL WINDS WILL KICK UP FOR A PERIOD OF NEAR 15 KTS
EACH EVENING AWAY FROM THE COAST. WIND DIRECTION WILL VARY FROM SSE
TO SSW. SEAS AOB 3 FT. THE MAIN MARINE CONCERN WILL CONTINUE TO BE
STORMS NEAR THE COAST/NEAR SHORE WATERS EACH AFTERNOON/EVENING AS
OVERALL MOISTURE REMAINS ELEVATED. WINDS/SEAS LOCALLY HIGHER INVOF
STORMS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 89 75 91 75 / 60 20 40 30
MCO 92 75 93 75 / 60 20 50 30
MLB 90 76 90 76 / 60 20 40 30
VRB 89 75 89 75 / 60 30 40 20
LEE 92 76 94 77 / 60 20 50 30
SFB 93 77 94 77 / 60 20 50 30
ORL 92 77 94 77 / 60 20 50 30
FPR 88 74 88 75 / 60 30 40 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
IMPACT WX...BRAGAW
PUBLIC SERVICE...CARTWRIGHT
FORECASTS...WIMMER
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
216 AM EDT Tue Jul 22 2014
.Near Term [Through Tonight]...
The 11 pm EDT regional surface analysis showed a decaying, wavy,
quasi-stationary, front from SC, through central GA, extending
southwestward to a broad, 1015 mb low centered over southern MS.
There was an east-west trough along I-10 in the FL Panhandle.
Vapor imagery and upper air data showed a cutoff low centered over
southwest GA, with a well-defined dry slot wrapping around the
west and southwest flank of the low, over the FL Panhandle and
adjacent coastal waters.
The GFS and ECMWF forecast the upper low to translate slowly
westward, providing weak Q-G forcing across GA & AL today. It
also appears that there will be slightly more deep layer moisture
in this region as well. Although they differ somewhat in
magnitude, the consensus of MOS and the Convection Allowing Models
(ECAM) PoPs generally range from 40 to 60% across our forecast
area today. The most concentrated area of deep moist convection
will initially be across Apalachee Bay and the FL Big Bend/North
FL this morning. This activity will gradually move inland and
diminish later this morning, but scattered storms will develop
across GA and AL this afternoon in association with the forcing
from the upper low and any mesoscale boundary interactions that
occur. Given the very weak wind field aloft and lackluster
forecast SBCAPE values (1500 J/kg or less), we`re expecting a less
than 5% chance of severe storms (within 25 miles of a point)
today. We expect high temperatures to be a little warmer today
than in recent days- around 90.
.Short Term [Wednesday Through Thursday Night]...
A mid-upper level low will continue to retrograde westward along
the Gulf coast and eventually get sheared out near coastal
Louisiana or Texas by Thursday. For Wednesday, this will allow for
a ridge to build into the area with negative vorticity advection
in those same layers. Computer models are in good agreement in
showing suppressed convective activity on Wednesday despite PWATs
very close to seasonal normals (around 1.9"). While this may be
the case, we think that the approx 20% PoPs the models are
advertising for the afternoon hours are too low without any
substantial drying - either at the surface or aloft. By Thursday,
another trough begins to dig into the region from the northwest
and could provide some additional large scale forcing for storms.
Therefore, we indicated scattered thunderstorms both afternoons
with PoPs around 30-40% in most areas. Temperatures should be
warmer than in recent days, with highs in the mid 90s likely.
.Long Term [Friday Through Tuesday]...
The large scale pattern commences rather amplified with ridging
over west, troughing over east and ridge over extreme Wrn Atlc.
At surface, ridge from Wrn Atlc to over local region with cold
front draped over mid-south. During the rest of the period, Wrn
ridge shifts Ewd with downstream trough pivoting and deepening Ewd
over local region on Fri before lifting Newd and flattening Sat
into Sun. Front inches swd shunting Gulf ridge further Swd
allowing for a return to a more WLY flow and normal summer time
sea breeze dominated regime. Will go with generally 30-40% aftn/eve
POPs thru the period. Expect highs generally in the low to mid
90s, lows low to mid 70s.
&&
.Aviation...
[Through 06Z Wednesday] The latest HRRR runs and GFS MOS suggest
a good chance of low-end MVFR/IFR CIGS through mid morning at
every site but KTLH. Conditions will improve to VFR by late
morning, outside of scattered TSRA. Initially the TSRA will be
concentrated near KTLH, but will spread to KVLD, KABY, and KDHN by
afternoon. The probability of TSRA at each terminal is 40-50%
today, except 30% at KECP. Of course gusty winds and brief period
of poor VIS/CIGS are expected with the stronger storms, but we
were not yet confident enough to explicitly forecast these
conditions at any site on the 06 UTC TAF package.
&&
.Marine...
Winds and seas should be relatively calm during the period - winds
generally 10 knots or less and seas generally 2 feet or less.
&&
.Fire Weather...
Red flag conditions are not expected this week.
&&
.Hydrology...
The Shoal River at Mossy Head briefly approached flood stage early
yesterday morning, but the river levels are now falling. There
will likely be some heavy rain rates today, and the storm motion
will be unusually slow (around 5 kt). This would suggest at least
some potential for flooding. However, there appears to be one
negative factor that will keep the risk of flooding rather low-
the influx of dry air aloft from the south and west. This should
help dampen deep moist convection somewhat, preventing updrafts
from persisting over any one location for too long. We think the
probability of exceeding local flash flood guidance today is about
5% (within 25mi of a point), which is not high enough for a watch.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 90 72 95 73 95 / 50 30 50 20 50
Panama City 87 75 90 76 90 / 30 20 30 20 30
Dothan 89 72 93 73 93 / 40 20 40 20 40
Albany 90 72 94 73 94 / 40 40 30 20 30
Valdosta 90 70 96 72 96 / 40 40 40 20 40
Cross City 90 71 94 73 92 / 60 30 40 20 40
Apalachicola 87 74 88 76 88 / 50 20 30 20 30
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...LAMERS
LONG TERM...BLOCK
AVIATION...FOURNIER
MARINE...LAMERS
FIRE WEATHER...FOURNIER
HYDROLOGY...LAMERS
AREA FORECAST DISCUSSION
NWS POCATELLO ID
149 PM MDT TUE JUL 22 2014
.DISCUSSION...EAST IDAHO REMAINS UNDER INFLUENCE OF SOUTHWEST FLOW
TODAY AND TONIGHT. SHORTWAVE PUSHING NORTHEAST FROM CALIFORNIA
WORKING WITH DEEP LOW OFF BC CANADA COAST TO MAINTAIN MOIST FLOW
INTO WESTERN PORTIONS OF STATE INCLUDING CENTRAL MOUNTAINS.
ALREADY SEEING BROAD CUMULUS FIELD ACROSS CENTRAL MOUNTAINS ALONG
WITH CIRRUS SHIELD EXTENDING SOUTHWEST TOWARD CALIFORNIA FEATURE.
RADAR PICKING UP WEAK RETURNS OVER PAHSIMEROI AND LEMHI REGIONS
EARLY THIS AFTERNOON. NAM AND GFS CONTINUE TO PRODUCE SCATTERED
CONVECTIVE DEVELOPMENT WITHIN THIS ZONE THOUGH RECENT HRRR RUNS
LESS FAVORABLE FOR CONVECTION ACROSS THE REGION. MODELS MAINTAIN
RELATIVELY THIN BAND OF ACTIVITY OVERNIGHT JUST ALONG WESTERN EDGE
OF FORECAST AREA BOUNDARIES SO WILL KEEP LOWER POPS THROUGH THE
CENTRAL MTNS OVERNIGHT AND INTO WEDNESDAY MORNING. ELSEWHERE MUCH
DRIER FLOW IN PLACE WITH PWAT VALUES DROPPING SIGNIFICANTLY
OVERNIGHT THROUGH THE SNAKE PLAIN AND SOUTHERN/EASTERN HIGHLANDS.
STRENGTHENING SURFACE LOW EJECTS NORTH INTO SOUTHERN IDAHO
OVERNIGHT WITH GOOD SOUTHERLY FLOW ACROSS THE REGION HELPING TO
ENHANCE DRYING. FLOW TURNS SOUTHWEST DURING THE DAY WEDNESDAY AS
NORTHERN LOW CENTER REACHES PACNW COAST AND DRY PUNCH EXTENDS
ACROSS MOST OF EASTERN IDAHO. HAVE KEPT WEAK POPS ACROSS CENTRAL
MOUNTAINS BUT CONFIDENCE IS LOW FOR PRECIP CHANCES WITH DRY
UPSTREAM FLOW ON WV SAT IMAGERY. BREEZY CONDITIONS EXPECTED BUT
MARGINAL AT THIS TIME FOR EVEN LAKE WIND CONCERNS. UPPER LOW
EJECTS EAST ALONG CANADIAN BORDER THROUGH THURSDAY...PUSHING DRY
COLD FRONT THROUGH THE REGION EARLY IN THE DAY. COOLER BUT WINDIER
DAY ON THURSDAY WITH SOME CONCERNS FOR FIRE /SEE DISCUSSION
BELOW/. GUIDANCE SHOWING WIDE SPREAD IN WIND VALUES SO WILL LEAVE
CURRENT GRIDS JUST BELOW ADVISORY CONDITIONS AT THIS TIME.
FRIDAY THROUGH SUNDAY RIDGE REBOUNDS THROUGH THE INTERMOUNTAIN
WEST. WARMER TEMPS AND DRY CONDITIONS WILL CONTINUE. MODELS STILL
HINTING AT SOME HINT OF A RETURN TO MONSOONAL TYPE FLOW BY MONDAY.
GFS AND ECMWF DIFFER SLIGHTLY IN AMOUNT OF CONVECTION AND SPREAD
MONDAY INTO TUESDAY. BELIEVE ISOLATED POPS OVER HIGHER ELEVATIONS
WILL SUFFICE FOR NOW UNTIL CLEARER PICTURE DEVELOPS. DMH
&&
.AVIATION...VFR CONDITIONS EXPECTED THROUGH THE PERIOD AT ALL TAF
SITES. THUNDERSTORMS ARE EXPECTED ONCE AGAIN IN THE CENTRAL
MOUNTAINS BUT WILL LIKELY BE NORTH OF KSUN SO KEPT IN A MENTION OF
VCTS. OTHERWISE...WINDY CONDITIONS ARE EXPECTED TO SET UP WEDNESDAY
AFTERNOON AND ESPECIALLY THURSDAY AFTERNOON.
EP
&&
.FIRE WEATHER...LINGERING THUNDERSTORMS CAN BE EXPECTED TODAY IN THE
CENTRAL MOUNTAINS AS AN UPPER LOW BEGINS TO MOVE INLAND IN
WASHINGTON STATE. THE REST OF THE AREA WILL BE UNDER DRIER AIR
MOVING IN FROM THE SOUTH. A DRYING TREND IS EXPECTED TO BEGIN FOR
THE ENTIRE AREA WEDNESDAY AS THAT UPPER LOW MOVES ALONG THE CANADIAN
BORDER...AND LAST THROUGH AT LEAST SATURDAY. AS THE LOW MOVES PAST
THE AREA...A DRY COLD FRONT WILL PASS THROUGH SE ID LATE WEDNESDAY
NIGHT INTO THURSDAY MORNING WHICH WILL DECREASE RH VALUES AND INCREASE
WINDS SIGNIFICANTLY IN THE AFTERNOON. CURRENTLY HAVE A FIRE WEATHER
WATCH OUT FOR ALL CRITICAL ZONES FOR THURSDAY AFTERNOON FOR THE
POTENTIAL OF A RED FLAG DAY OCCURRING AS A RESULT OF LOW RH AND HIGH
WINDS.
EP
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING IDZ410-425.
FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING IDZ422-427.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
306 PM EDT TUE JUL 22 2014
.SYNOPSIS...
ISSUED AT 306 PM EDT TUE JUL 22 2014
HOT AND HUMID WEATHER WILL PERSIST LATE THIS AFTERNOON INTO EARLY
THIS EVENING IN ADVANCE OF A COLD FRONT. THIS COLD FRONT WILL
SWING THROUGH TONIGHT INTO WEDNESDAY MORNING WITH SHOWERS AND
THUNDERSTORMS POSSIBLE ALONG IT. COOLER AND DRIER AIR WILL FILTER
IN LATER WEDNESDAY THROUGH THE END OF THE WEEK...WITH STORM
CHANCES AND WARMER TEMPERATURES RETURNING THIS WEEKEND.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 306 PM EDT TUE JUL 22 2014
REGIONAL RADARS SHOWING ONGOING CONVECTION CONTINUES TO MOVE ACROSS
FAR NORTHERN GREAT LAKES/SOUTHERN CANADA WITH SURFACE LOW WHILE
EARLIER MCS DISSIPATING OVER THE MID MISSISSIPPI VALLEY WITH NEW
CELLS STARTING TO FORM OVER IOWA THIS AFTERNOON. WATER VAPOR IMAGERY
AND LATEST RUC ANALYSIS SHOWS SHORT WAVE TROF MOVING ACROSS LAKE
SUPERIOR WITH UPPER JET WELL TO THE NORTH OVER THE HUDSON BAY. THIS
DETACHMENT OF UPPER FORCING WILL BE PROBLEMATIC FOR CONVECTION
MAINTAINING ALONG THE COLD FRONT AS IT MOVES THROUGH OVERNIGHT. BEST
CHANCES APPEAR TO BE IN THE NW CWA AS DECENT MASS CONVERGENCE ALONG
COLD FRONT WILL COMBINE WITH MODEST ELEVATED INSTABILITY...CAPES
AROUND 1500J/KG...SO IF CONVECTION IN IOWA IS ABLE TO BECOME MORE
ORGANIZED IT MAY HAVE ENOUGH SUPPORT TO MAINTAIN CONVECTIVE
COMPLEX...HOWEVER FORMING RIGHT ALONG THICKNESS RIDGE WILL HAVE SOME
UNCERTAINTY IN ITS FORWARD PROPAGATION. FRONT EXPECTED TO PUSH
THROUGH MUCH OF THE CWA BY WEDNESDAY MORNING WITH JUST LINGERING
CHANCES IN THE FAR SE CWA...TRENDING TOWARD A DRY FORECAST FOR THE
ENTIRE AREA BY AFTERNOON. WARM AND MUGGY CONDITIONS EXPECTED TONIGHT
FOR THE SE HALF WITH LOWS AROUND 70 WHILE FRONTAL PASSAGE WILL ALLOW
TEMPS TO DROP INTO THE MID 60S NW. COOLER AND LESS HUMID FOR
WEDNESDAY WITH HIGHS 75-80.
&&
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 306 PM EDT TUE JUL 22 2014
COMFORTABLE/FAIR WX WILL PREVAIL WEDNESDAY NIGHT THROUGH FRIDAY
MORNING AS STABLE CANADIAN HIGH PRESSURE DROPS THROUGH. MID-UPPER
LEVEL FLOW WILL BRIEFLY TRANSITION TO A FLATTER/SEMI-ZONAL WNW
REGIME BY LATE FRIDAY INTO SATURDAY...WHILE IN THE LOW LEVELS WINDS
VEER MORE SOUTHERLY ALLOWING AN ACTIVE WARM FRONT TO WORK ENE INTO
THE REGION. LEAD/WEAK SHORTWAVE IN ADVANCE OF PRIMARY SHORTWAVE
TROUGH AND INCREASING MASS/MOISTURE CONVERGENCE ALONG THE DEVELOPING
FRONT SUPPORT INHERITED CHANCE POPS FOR SHOWERS/STORMS DURING THIS
TIME...MAINLY LATER FRIDAY NIGHT INTO SATURDAY.
RE-AMPLIFICATION OF EASTERN CONUS TROUGH REMAINS A CONSISTENT SIGNAL
IN MODEL GUIDANCE SUNDAY INTO EARLY NEXT WEEK. COLD FRONT ON LEADING
EDGE OF HEIGHT FALLS MAY SUPPORT ANOTHER ROUND OF CONVECTION LATER
SATURDAY NIGHT-SUNDAY DEPENDING ON TIMING. UNSEASONABLY COOL AND
MAINLY DRY WX LIKELY RETURNS EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 123 PM EDT TUE JUL 22 2014
DAYTIME MIXING HAS WINDS STARTING TO GUST THIS AFTERNOON...WITH
BETTER GRADIENT APPROACHING FROM THE NORTHWEST WILL CARRY A G22 AT
KSBN THIS AFTERNOON BUT NOT MENTION AT KFWA. COLD FRONT APPROACHING
THIS EVENING AND MOVING THROUGH OVERNIGHT WILL A SMALL CHANCE FOR
SH/TSRA INTO THE AREA...BETTER INSTABILITY TO ACCOMPANY FRONT IN NW
CWA SO WILL HAVE A TEMPO AT KSBN BUT LEAVE OUT ANY MENTION OF
THUNDER FOR NOW. AMPLE LOW LEVEL MOISTURE BEHIND FRONT COULD MAKE
FOR MVFR CIGS EARLY MORNING ON WEDNESDAY...STRONG GRADIENT AS WELL
WITH NW WINDS AROUND 15KTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY
MORNING FOR INZ003.
MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY
MORNING FOR MIZ077.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 4 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR LMZ043-046.
&&
$$
SYNOPSIS...STEINWEDEL
SHORT TERM...JAL
LONG TERM...STEINWEDEL
AVIATION...JAL
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 PM MDT TUE JUL 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1255 PM MDT TUE JUL 22 2014
18Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE CENTERED
OVER NEW MEXICO WITH RUC ANALYSIS INDICATING A 600 DM RIDGE IN
PLACE AT H5. AT THE SFC...OUTFLOW BOUNDARY HAS STALLED ACROSS THE
EXTREME SOUTHERN CWA...BETWEEN TRIBUNE AND LEOTI EXTENDING
NORTHEAST TOWARDS HILL CITY.
MAIN CONCERNS FOR THE SHORT TERM WILL BE TEMPS AND PRECIP CHANCES
THIS EVENING AND TOMORROW AFTERNOON.
LACK OF ANY MEANINGFUL CU FIELD AT 19Z LOWERS OVERALL CONFIDENCE
IN LATE AFTERNOON THUNDERSTORM FORECAST AND WHILE AN ISOLATED
STORM IS STILL POSSIBLE...HAVE DOUBTS THAT ANYTHING WILL FIRE
ALONG REMAINING OUTFLOW BOUNDARY. WITH H85-H7 WAA INCREASING
TONIGHT...IT WILL BE POSSIBLE FOR STORMS COMING OUT OF THE
NORTHWEST TO MAINTAIN THEMSELVES BUT WITH WEAK WINDS THROUGHOUT
THE COLUMN STORM MOTION WOULD BE SLOW. A FEW MODELS SUGGEST
ELEVATED CONVECTION DEVELOPING AFTER 06Z AND WHILE THE FORCING
WILL BE THERE...CONDENSATION PRESSURE DEFICITS AND PRESSURE
ADVECTION VALUES ON 310 AND 315K SURFACES WOULD SUGGEST SATURATION
UNLIKELY. IF STORMS/CLOUDS CANNOT DEVELOP...BACKED EASTERLY FLOW
WITH A 100MB POCKET OF LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST
PATCHY FOG PRIOR TO 15Z. GENERAL CONSENSUS OF MODELS SUGGESTS
TEMPERATURES AROUND 5 DEGREES COOLER ON WEDNESDAY THAN
TODAY...GIVEN EXPECTED SFC PATTERN THAT APPEARS REASONABLE.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 231 PM MDT TUE JUL 22 2014
A RIDGE OVER THE ROCKIES/PLAINS WILL SHIFT TO THE DESERT SOUTHWEST
BY FRIDAY. A SURFACE TROUGH WILL BE IN EASTERN COLORADO FROM
WEDNESDAY NIGHT UNTIL IT SHIFTS INTO SOUTHWEST KANSAS FRIDAY.
THE SURFACE TROUGH WILL FOCUS THUNDERSTORM DEVELOPMENT WEDNESDAY
EVENING. A SHORTWAVE MOVES INTO THE AREA WILL PROVIDE FORCING. CAPE
WILL RANGE FROM 1000 TO 2000J/KG AND SHEAR WILL BE 20KTS. FORECAST
SOUNDINGS INDICATE AN OVERALL LACK OF MID LEVEL MOISTURE SO WILL
CONTINUE SLIGHT CHANCE POPS.
FOR THURSDAY AFTERNOON AND EVENING, THE SURFACE TROUGH WILL BE
ORIENTED ACROSS NORTHWEST KANSAS BUT ONCE AGAIN FORECAST SOUNDINGS
SHOW HIGH BASED MOISTURE AROUND 600MB. CAPE RANGES FROM 200J/KG IN
EASTERN COLORADO TO 800J/KG IN THE EAST. DUE TO THESE MARGINAL
PARAMETERS WILL STAY WITH SLIGHT CHANCE POPS WITH COVERAGE OVER THE
ENTIRE FA AS THE TROUGH SHIFTS SOUTH DURING THE EVENING.
SURFACE CONVERGENCE AND HEATING WILL BE THE MAIN FORCING FRIDAY
AFTERNOON WITH THE TROUGH WELL TO THE SOUTH OF THE FA. STORMS SHOULD
INITIATE ON THE HIGHER TERRAIN IN EASTERN COLORADO WHERE LIFT WILL BE
MAXIMIZED. SLIGHT CHANCE POPS WILL CONTINUE FOR FRIDAY AFTERNOON.
MAX TEMPERATURES WILL REACH THE UPPER 90S THURSDAY AND FRIDAY. MIN
TEMPERATURES WILL COOL TO THE UPPER 60S WITH AROUND 70 IN THE EAST.
IN THE EXTENDED...(FRIDAY NIGHT THROUGH TUESDAY)...
THE RIDGE OVER THE SOUTHERN ROCKIES WITH SHIFT TO THE DESERT
SOUTHWEST BY SATURDAY AND CONTINUE THROUGH TUESDAY. THERE IS A
SLIGHT CHANCE OF THUNDERSTORMS FRIDAY/SATURDAY WITH STORMS
DEVELOPING DUE TO UPSLOPE WIND/SURFACE CONVERGENCE OVER THE HIGHER
TERRAIN IN EASTERN COLORADO. THESE STORMS WILL MOVE SLOWLY EAST
INTO NORTHWEST KANSAS. NUMEROUS WEAK DISTURBANCES IN NORTHWEST FLOW
WILL PROVIDE FORCING FOR AT LEAST A SLIGHT CHANCE/CHANCE OF
THUNDERSTORMS EACH DAY FROM SUNDAY THROUGH TUESDAY.
MIN TEMPERATURES WILL RANGE FROM 65 TO 70 FRIDAY AND SATURDAY NIGHTS
COOLING TO THE MID 60S SUNDAY AND MONDAY NIGHTS. MAX TEMPERATURES
WILL REACH THE MID 90S SATURDAY COOLING TO THE UPPER 80S FROM SUNDAY
THROUGH TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1137 AM MDT TUE JUL 22 2014
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND INTO THE
EVENING...BUT OVERALL PROBABILITIES TOO LOW AT THIS POINT IN TIME
TO INCLUDE IN TAFS. SMALL THREAT FOR FOG DEVELOPMENT AFTER 09Z
ACROSS NORTHERN HALF OF AREA. STILL A FAIR BIT OF DISCREPANCY WITH
RESPECT TO EXPECTED MOISTURE PROFILES...SO HAVE LIMITED IMPACT ON
AVIATION CATEGORIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ003-004-015-016-
029.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...FS
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS GOODLAND KS
107 PM MDT TUE JUL 22 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 1255 PM MDT TUE JUL 22 2014
18Z WATER VAPOR IMAGERY INDICATED LARGE UPPER LEVEL RIDGE CENTERED
OVER NEW MEXICO WITH RUC ANALYSIS INDICATING A 600 DM RIDGE IN
PLACE AT H5. AT THE SFC...OUTFLOW BOUNDARY HAS STALLED ACROSS THE
EXTREME SOUTHERN CWA...BETWEEN TRIBUNE AND LEOTI EXTENDING
NORTHEAST TOWARDS HILL CITY.
MAIN CONCERNS FOR THE SHORT TERM WILL BE TEMPS AND PRECIP CHANCES
THIS EVENING AND TOMORROW AFTERNOON.
LACK OF ANY MEANINGFUL CU FIELD AT 19Z LOWERS OVERALL CONFIDENCE
IN LATE AFTERNOON THUNDERSTORM FORECAST AND WHILE AN ISOLATED
STORM IS STILL POSSIBLE...HAVE DOUBTS THAT ANYTHING WILL FIRE
ALONG REMAINING OUTFLOW BOUNDARY. WITH H85-H7 WAA INCREASING
TONIGHT...IT WILL BE POSSIBLE FOR STORMS COMING OUT OF THE
NORTHWEST TO MAINTAIN THEMSELVES BUT WITH WEAK WINDS THROUGHOUT
THE COLUMN STORM MOTION WOULD BE SLOW. A FEW MODELS SUGGEST
ELEVATED CONVECTION DEVELOPING AFTER 06Z AND WHILE THE FORCING
WILL BE THERE...CONDENSATION PRESSURE DEFICITS AND PRESSURE
ADVECTION VALUES ON 310 AND 315K SURFACES WOULD SUGGEST SATURATION
UNLIKELY. IF STORMS/CLOUDS CANNOT DEVELOP...BACKED EASTERLY FLOW
WITH A 100MB POCKET OF LOW LEVEL MOISTURE WOULD SUPPORT AT LEAST
PATCHY FOG PRIOR TO 15Z. GENERAL CONSENSUS OF MODELS SUGGESTS
TEMPERATURES AROUND 5 DEGREES COOLER ON WEDNESDAY THAN
TODAY...GIVEN EXPECTED SFC PATTERN THAT APPEARS REASONABLE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 136 AM MDT TUE JUL 22 2014
FOR THE PERIODS WEDNESDAY THROUGH THURSDAY NIGHT...THE FORECAST AREA
WILL CONTINUE TO SEE MAINLY HOT AND DRY CONDITIONS WITH BROAD H5
RIDGE OVER THE CENTRAL PORTION OF THE COUNTRY. THERE WILL BE THE
CHANCE FOR LATE AFTERNOON/EARLY EVENING CONVECTION DURING THIS TIME
AS CWA WILL SEE FRONTAL BOUNDARY WEDNESDAY AND LEE-SIDE TROUGH
AFFECT THE REGION THURSDAY/THURSDAY NIGHT. GOING FOR MAINLY SLIGHT
CHANCE POPS FOR CONVECTION DURING THIS TIME. FRONT ON WEDNESDAY WILL
MAINLY AFFECT NORTHERN ZONES BASED ON LATEST GUIDANCE BEFORE FALLING
APART BY 00Z THURSDAY. WESTERN ZONES THURSDAY WILL SEE TRW CHANCES
FIRST BEFORE SYSTEM SHIFTS EAST GIVING EASTERN ZONES BETTER CHANCE
FOR PRECIPITATION. 925 MB TEMPS THRU PERIOD WILL RANGE IN THE +30 TO
+36C WHICH GIVE 90S TO THE AREA...BUT WILL BE CLOUD DEPENDENT FROM
EXPECTED PRECIPITATION.
THE LAST WEEKEND OF JULY WILL BE AN ACTIVE ONE WITH CHANCES FOR
THUNDERSTORMS AND COOLING TREND TOWARDS NEXT WEEK. ON THE SYNOPTIC
SCALE FLOW WILL BE NEAR-ZONAL AT MID AND UPPER LEVELS ACROSS THE
CENTRAL HIGH PLAINS. THE UPPER HIGH THAT IS OVER THE REGION TODAY
SLOWLY RETROGRADES SOUTHWESTWARD INTO THE FOUR CORNERS REGION. AT
THE SAME TIME A LONGWAVE TROUGH WILL BEGIN TO DIG INTO THE EASTERN
THIRD OF THE CONUS...RESULTING IN NORTHWESTERLY FLOW AS A RIDGE
DEVELOPS OVER THE NORTHERN GREAT BASIN REGION.
FRIDAY WILL PROBABLY BE THE LAST DAY IN THE FORECAST PERIOD WITH A
CHANCE OF SEEING TRIPLE DIGIT TEMPS. A WEAK COLD FRONT DROPS SOUTH
THROUGH THE REGION LATE FRIDAY WHICH IS NOT EXPECTED TO IMPACT TEMPS
MUCH INITIALLY...BUT THE BOUNDARY COULD SERVE AS A FOCUS FOR STORMS
MAINLY SOUTH OF INTERSTATE 70 LATE IN THE DAY AND INTO THE EVENING
AS A MID-LEVEL SHORTWAVE TROUGH MOVES ACROSS EASTERN COLORADO INTO
WESTERN KANSAS PROVIDING AMPLE UPWARD MOTION FOR BOTH ISOLATED
STORMS ALONG THE FRONT AND TERRAIN-BASED CONVECTION. SOUNDINGS
QUICKLY STABILIZE OVERNIGHT...SO ANY STORMS THAT CAN POP UP WILL NOT
LAST LONG.
SATURDAY WILL BE NOT AS HOT WITH A PRETTY GOOD CHANCE FOR
STORMS...WITH THE BEST CHANCE IN EASTERN COLORADO AND ADJACENT
COUNTIES IN WESTERN KANSAS AND SOUTHWEST NEBRASKA. MOST OF THE DAY
WILL BE DRY...BUT AS INSTABILITY INCREASES TO 1500-2000+ J/JG MUCAPE
/UNCAPPED/ WITH STEEP LOW LEVEL LAPSE RATES AND AROUND 40 KTS
EFFECTIVE SHEAR...STRONG TO SEVERE THUNDERSTORMS WILL BE A
POSSIBILITY. THE 00Z CYCLE GUIDANCE IS A BIT SLOWER ON THE LARGE
SCALE LIFT ARRIVAL COMPARED TO PAST RUNS...BUT IN THIS ENVIRONMENT
WE WILL NOT NEED MUCH TO GET STORMS GOING. THE COLD FRONT FROM LATE
FRIDAY IS EXPECTED TO BE SITTING IN AN EAST-WEST FASHION SOMEWHERE
ACROSS WESTERN KANSAS...AND IN THIS VICINITY WOULD BE THE BEST
CHANCE FOR INITIAL DEVELOPMENT. AS LONG AS STORMS DEVELOP THEY ARE
EXPECTED TO LAST INTO THE OVERNIGHT HOURS...WITH A 25-30KT LOW LEVEL
JET AND PLENTY OF ELEVATED CAPE TO KEEP THINGS GOING. STORM MOTIONS
TOWARDS THE SOUTHEAST AT 10 TO 15 KTS SHOULD BE ENOUGH TO PRECLUDE A
MAJOR FLASH FLOOD THREAT. HIGHS IN THE MID 90S.
SUNDAY EXPECT ANY ONGOING OVERNIGHT PRECIP TO END BY SUNRISE AS
COOLER...WITH ANOTHER ROUND OF MORE STRATIFORM RAIN WITH ISOLATED
THUNDER TO MOVE IN LATE IN THE DAY. GFS DETERMINISTIC IS A DRY
OUTLIER IN THIS SCENARIO...BUT GEFS MEMBERS AGREE WELL WITH
ECMWF/GEM FOR A SCATTERED SHOWERS/STORMS SCENARIO. INSTABILITY IS
NOT EXTREME...SO THIS WILL NOT BE AS INTENSE OF AN EVENT AS
SATURDAY/SATURDAY NIGHT...BUT COULD SEE CLOUDS KEEPING THINGS SOCKED
IN MUCH OF THE DAY WITH OFF AND ON SHOWERS. HIGHS RELATIVELY
COOLER...ESPECIALLY IF CLOUD COVER IS MORE THAN EXPECTED...IN THE
LOW 90S.
MONDAY WILL BE COOLER WITH THE CHANCE FOR SHOWERS/STORMS CONTINUING
DURING THE DAY. AS WITH SUNDAY THE GFS DETERMINISTIC IS VERY
DRY...BUT GIVEN CLIMO POPS ARE IN THE LOW 20S FELT POPS IN THE MID
20S WAS JUST FINE GIVEN THE INHERENT UNCERTAINTY FOR A DAY 7
FORECAST. TEMPS COOLER...AGAIN ESPECIALLY SO IF CLOUDS STICK AROUND
FOR MOST THE DAY...WITH HIGHS IN THE UPPER 80S TO NEAR 90.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1137 AM MDT TUE JUL 22 2014
THUNDERSTORMS WILL BE POSSIBLE LATE THIS AFTERNOON AND INTO THE
EVENING...BUT OVERALL PROBABILITIES TOO LOW AT THIS POINT IN TIME
TO INCLUDE IN TAFS. SMALL THREAT FOR FOG DEVELOPMENT AFTER 09Z
ACROSS NORTHERN HALF OF AREA. STILL A FAIR BIT OF DISCREPANCY WITH
RESPECT TO EXPECTED MOISTURE PROFILES...SO HAVE LIMITED IMPACT ON
AVIATION CATEGORIES.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR KSZ003-004-015-016-
029.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...JRM
LONG TERM...JJM
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
307 AM CDT Tue Jul 22 2014
...Updated long term section...
.SHORT TERM...(Today and tonight)
ISSUED AT 145 AM CDT TUE JUL 22 2014
Today temperatures will climb to around 100 degrees based the
mean mixing depth forecast by the NAM and GFS along with the
temperatures at 00z Wednesday in the 850mb to 700mb level. All
models, and even guidance, continues to indicated lower dew points
today compared to yesterday, however based on verification of dew
points from yesterday afternoon it appears that the models are too
low by 3-6 degrees. Taking this discrepancies into account and
given the expected highs will go ahead an issue a heat advisory
for portions of north central Kansas. will need to monitor the
Medicine lodge area given several hours of Heat index readings at
104 which is just below advisory criteria.
A weak cold front/surface boundary will stall out in northern
Kansas by early evening and a surface trough of low pressure will
extend south/southwest of this boundary into the panhandle of
Oklahoma. Both areas will be the main focusing mechanism for
evening convection as CAPE values by 00z climb to greater than
2000 j/kg. Better forcing currently appears to be along and north
of the cold front. Also appear the cap will be weaker in this
location as well. Will therefore focus main chances for evening
and overnight convection along and north of this weak cold front
while keeping convection more widely scattered further south.
0-6km shear is forecast to be around 30knots across northern
Kansas so strong to marginally severe thunderstorms can not be
ruled out. Strong gusty winds currently appears to be the main
hazard should any storm develop along the surface lee trough
extending south of this cold front early this evening based on
model soundings.
.LONG TERM...(Wednesday through Monday)
ISSUED AT 306 AM CDT TUE JUL 22 2014
A dry pattern is expected Wednesday through Friday as an upper level
ridge builds across the Southern and Central Rockies. Weak
shortwaves will move around the periphery of this ridge, but they
look to move well north of the area and not affect southwest Kansas.
In addition, warm mid level temperatures should also cap most
convection from initialing across the higher terrain in eastern
Colorado. Skies should be partly cloudy through this period. Towards
the surface, a trough of low pressure will be located across the
KS/CO border Wednesday through Friday morning allowing southerly
winds to be felt across western Kansas. As for temperatures, highs
Wednesday look to reach into the mid to upper 90s with around 100
degrees expected Thursday and Friday. Lows through sunrise Saturday
are expected to be in the lower 70s.
A slight cool down is expected this weekend as winds shift to more
of an easterly direction and storm chances increase. The upper level
ridge slides westward during this time frame as an upper level low
moves down through Central Canada and the Northern Plains Saturday
then into the Great Lakes region Sunday. This low then stalls across
eastern Canada and the Northeast United States for the first part of
next week. This feature will help push a cold front through the area
Saturday and be the focal point of where convection could initiate.
Upslope flow is then expected Sunday into Monday which will help
with increased low level moisture and continued chances of
thunderstorms. Highs this weekend into Monday look to be in the 90s
with close to 100 degrees across the KS/OK border on Saturday. Lows
will be in the low 70s Sunday morning decreasing to the mid to upper
60s by Tuesday morning.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1206 AM CDT TUE JUL 22 2014
Ongoing light precipitation will gradually taper off from
northwest to southeast early this morning with 05z surface
observations, 00z NAM BUFR soundings, and latest HRRR indicating
ceilings will be above the 6000ft AGL level with this
precipitation. Winds will be variable at 10knots or less around
the ongoing precipitation but after 09z become southwest. Wind
speeds will increase to near 15knots by late morning and persist
through the remainder of the day. VFR conditions are also expected
through the day on Tuesday. A weak cold front will approach the
Hays area by early evening allowing for the southerly winds to
shift to the east/northeast between 00z Tuesday and 03z Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 95 70 / 10 10 10 10
GCK 100 72 96 70 / 10 10 10 10
EHA 98 70 97 70 / 20 20 10 10
LBL 100 70 97 70 / 0 10 10 10
HYS 102 72 93 70 / 10 20 10 10
P28 101 74 97 72 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY from Noon today to 8 PM CDT this evening FOR
KSZ030-031-046-065-066-081-089-090.
&&
$$
SHORT TERM...Burgert
LONG TERM...Hovorka_42
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
148 AM CDT Tue Jul 22 2014
...Updated short term discussion...
.SHORT TERM...(Today and tonight)
ISSUED AT 145 AM CDT TUE JUL 22 2014
Today temperatures will climb to around 100 degrees based the
mean mixing depth forecast by the NAM and GFS along with the
temperatures at 00z Wednesday in the 850mb to 700mb level. All
models, and even guidance, continues to indicated lower dew points
today compared to yesterday, however based on verification of dew
points from yesterday afternoon it appears that the models are too
low by 3-6 degrees. Taking this discrepancies into account and
given the expected highs will go ahead an issue a heat advisory
for portions of north central Kansas. will need to monitor the
Medicine lodge area given several hours of Heat index readings at
104 which is just below advisory criteria.
A weak cold front/surface boundary will stall out in northern
Kansas by early evening and a surface trough of low pressure will
extend south/southwest of this boundary into the panhandle of
Oklahoma. Both areas will be the main focusing mechanism for
evening convection as CAPE values by 00z climb to greater than
2000 j/kg. Better forcing currently appears to be along and north
of the cold front. Also appear the cap will be weaker in this
location as well. Will therefore focus main chances for evening
and overnight convection along and north of this weak cold front
while keeping convection more widely scattered further south.
0-6km shear is forecast to be around 30knots across northern
Kansas so strong to marginally severe thunderstorms can not be
ruled out. Strong gusty winds currently appears to be the main
hazard should any storm develop along the surface lee trough
extending south of this cold front early this evening based on
model soundings.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 150 PM CDT MON JUL 21 2014
A shortwave trough riding over the top of the upper level ridge will
progress from the northern plains today into the Great Lakes by
Tuesday and then into the Middle Atlantic region by Wednesday.
This will help push a cold front into central Kansas by Tuesday
evening and northern Oklahoma by Wednesday morning. There is only
a slight chance of thunderstorms Tuesday evening along a weak
surface trough in far western Kansas and then along the cold front
Tuesday night. Aside from some wind and small hail from these high
based storms in the evening, high-end severe weather is not
expected.
It will be humid Wednesday behind the cold front, especially near
the Oklahoma state line, but with no upper level support or surface
convergence, thunderstorms are not expected. Temperatures should be
several degrees cooler, with highs from 93F near interstate 70 to
around 97F near the Oklahoma state line. By Thursday, a strong upper
level system will move into the northwestern United States, with
ridging extending from the Desert Southwest into western Kansas.
With renewed lee troughing, high temperatures ought to warm back
to the mid and high 90s, with possibly some readings near or over
100F. Little in the way of thunderstorm activity is expected. The
next cold front is expected to pass through western Kansas by
Saturday or Sunday as the upper level system over the northwestern
United States passes over the upper level ridge into the Great
Lakes, with the associated cold front moving through western
Kansas. There is some disagreement from model to model and model
run to model run with the strength of this cold front. Keep in
mind that if the front is stronger, then high temperatures could
drop lower than currently forecast. Regardless of the solution,
high temperatures ought to drop at least several degrees by Sunday.
There will be small chances for thunderstorms as the front passes.
A more significant cool down is possible by mid next week as an
even stronger upper level system moves over the ridge and
amplifies over the upper Midwest and Great Lakes regions.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1206 AM CDT TUE JUL 22 2014
Ongoing light precipitation will gradually taper off from
northwest to southeast early this morning with 05z surface
observations, 00z NAM BUFR soundings, and latest HRRR indicating
ceilings will be above the 6000ft AGL level with this
precipitation. Winds will be variable at 10knots or less around
the ongoing precipitation but after 09z become southwest. Wind
speeds will increase to near 15knots by late morning and persist
through the remainder of the day. VFR conditions are also expected
through the day on Tuesday. A weak cold front will approach the
Hays area by early evening allowing for the southerly winds to
shift to the east/northeast between 00z Tuesday and 03z Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 100 72 95 70 / 10 10 10 10
GCK 100 72 96 70 / 10 10 10 10
EHA 98 70 97 70 / 10 20 10 10
LBL 100 70 97 70 / 0 10 10 10
HYS 102 72 93 70 / 20 20 10 10
P28 101 74 97 72 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
HEAT ADVISORY from Noon today to 8 PM CDT this evening FOR
KSZ030-031-046-065-066-081-089-090.
&&
$$
SHORT TERM...Burgert
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1209 AM CDT Tue Jul 22 2014
...Updated synopsis and aviation...
.SYNOPSIS...
ISSUED AT 1206 AM CDT TUE JUL 22 2014
At 00z Tuesday a 500mb high was located over northeast New Mexico
with an upper level ridge axis extending northeast of this high
into Illinois. One upper level trough was evident at over
northwest Kansas with another, more subtle, upper wave appearing
over Nevada near the nose/left exit region of a 250mb jet.
Anticyclonic flow was present at the 700mb level with temperatures
of +15c at Dodge City and +16c at Amarillo and North Platte at 00z
Tuesday. A area of higher 850mb temperatures, +28c to +31c, were
located from northwest Colorado into eastern South Dakota. This
was also located just ahead of a cold front which extended from
eastern Wyoming to eastern North Dakota. 850mb temperature at
Dodge City at 00z Tuesday was +27c.
&&
.SHORT TERM...(This evening through Tuesday)
ISSUED AT 116 PM CDT MON JUL 21 2014
High pressure aloft will remain centered over southern Colorado and
northern New Mexico through the next 48 hours. This will ensure
very hot surface temperatures will continue, with most of
southwest Kansas rising into the triple digits today and Tuesday.
At the same time, a lee side surface trough will be advancing
into far western Kansas late this afternoon and evening. This
trough will be the focus axis for some convection, and that trough
could push some of those thunderstorms a bit farther east late
this evening. There could be a slight chance for thunderstorms
after midnight in our north and northeast zones, with the surface
trough moving through central Kansas. In any case, I will not put
very much QPF amounts with these storms. After the hot afternoon,
the overnight temperatures will be elevated, and generally in the
the lower to mid 70s tonight. Winds will be southwest early in
the 15-20 MPH range, and then become more southerly as that surface
trough advances farther east and reduce to the 10 to 12 MPH range.
On Tuesday, the upper high pressure system will still be in
control. However, at the surface, a weak cold front will drop south
from the northern plains and essentially drop into that surface
trough. This could trigger a few thunderstorms along and near the
front/trough, across our north and western zones late in the afternoon.
Maximum temperatures will likely occur prior to the front moving
south, and thus even the Hays area will likely see 101F readings.
Dew points will again be in the mid 50s in our west to the mid to
upper 60s in our east, which only gives a max heat index of 103F,
just shy of Heat Advisory criteria. This will need to be watched,
and updated if needed. Winds on Tuesday should be south at 10 to
12 mph, but shifting to the east in our far eastern counties, on
the other side of the trough.
.LONG TERM...(Tuesday night through Monday)
ISSUED AT 150 PM CDT MON JUL 21 2014
A shortwave trough riding over the top of the upper level ridge will
progress from the northern plains today into the Great Lakes by
Tuesday and then into the Middle Atlantic region by Wednesday.
This will help push a cold front into central Kansas by Tuesday
evening and northern Oklahoma by Wednesday morning. There is only
a slight chance of thunderstorms Tuesday evening along a weak
surface trough in far western Kansas and then along the cold front
Tuesday night. Aside from some wind and small hail from these high
based storms in the evening, high-end severe weather is not
expected.
It will be humid Wednesday behind the cold front, especially near
the Oklahoma state line, but with no upper level support or surface
convergence, thunderstorms are not expected. Temperatures should be
several degrees cooler, with highs from 93F near interstate 70 to
around 97F near the Oklahoma state line. By Thursday, a strong upper
level system will move into the northwestern United States, with
ridging extending from the Desert Southwest into western Kansas.
With renewed lee troughing, high temperatures ought to warm back
to the mid and high 90s, with possibly some readings near or over
100F. Little in the way of thunderstorm activity is expected. The
next cold front is expected to pass through western Kansas by
Saturday or Sunday as the upper level system over the northwestern
United States passes over the upper level ridge into the Great
Lakes, with the associated cold front moving through western
Kansas. There is some disagreement from model to model and model
run to model run with the strength of this cold front. Keep in
mind that if the front is stronger, then high temperatures could
drop lower than currently forecasted. Regardless of the solution,
high temperatures ought to drop at least several degrees by Sunday.
There will be small chances for thunderstorms as the front passes.
A more significant cooldown is possible by mid next week as an
even stronger upper level system moves over the ridge and
amplifies over the upper Midwest and Great Lakes regions.
&&
.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
ISSUED AT 1206 AM CDT TUE JUL 22 2014
Ongoing light precipitation will gradually taper off from
northwest to southeast early this morning with 05z surface
observations, 00z NAM BUFR soundings, and latest HRRR indicating
ceilings will be above the 6000ft AGL level with this
precipitation. Winds will be variable at 10knots or less around
the ongoing precipitation but after 09z become southwest. Wind
speeds will increase to near 15knots by late morning and persist
through the remainder of the day. VFR conditions are also expected
through the day on Tuesday. A weak cold front will approach the
Hays area by early evening allowing for the southerly winds to
shift to the east/northeast between 00z Tuesday and 03z Tuesday.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 72 95 70 98 / 10 10 10 10
GCK 72 96 70 99 / 10 10 10 10
EHA 70 97 70 101 / 20 10 10 10
LBL 70 97 70 101 / 10 10 10 10
HYS 72 93 69 94 / 20 10 10 10
P28 74 97 72 94 / 10 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burke
LONG TERM...Finch
AVIATION...Burgert
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
716 PM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE REGION TONIGHT AND EXITS
OFFSHORE THURSDAY MORNING. HIGH PRESSURE BUILDS IN FROM THE WEST
FRIDAY AND SATURDAY. WET WEATHER WILL ONCE AGAIN BE POSSIBLE LATE
IN THE WEEKEND AND EARLY NEXT WEEK AS THE NEXT UPPER TROUGH DIVES
IN.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
.UPDATE..
HAVE CANCELLED THE WATCH FOR GRAFTON...COOS...OXFORD...AND
SOMERSET COUNTIES AND ALLOWED FRANKLIN COUNTY TO STAY IN THE WATCH
TO ACCOUNT FOR THE SEVERE STORMS IN THE SOUTHERN PART OF THE
COUNTY. SOMEWHAT MORE ORGANIZED WESTERN PART OF THE SQUALL LINE
FROM GRAY SW HAS BEEN HAS MORE SEVERE ELEMENTS THAN THE EASTERN
HALF...EXHIBITING MORE UPDRAFT STRENGTH AND LIGHTNING. THESE
CELLS WILL CONTINUE UNTIL THEY MOVE OFFSHORE AND LIKELY PRODUCE 34
KT+ OVER THE WATERS. MORE DISORGANIZED SHOWERS AND ISOLATED STORMS
BEHIND OUTFLOW OVER THE MIDCOAST SHOULD JUST POSE ONLY A RAIN
THREAT. LIGHT TO MODERATE RAIN WILL CONTINUE OVERNIGHT OVER THE
ENTIRE AREA IN THIS ANAFRONTAL PATTERN BUT FLOODING SHOULD NOT BE
A CONCERN. PATCHY FOG DENSE WILL DEVELOP AREAWIDE AND ADDED THIS
TO THE FORECAST.
WILL CANCEL REMAINING COUNTIES FROM THE WATCH AS SEVERE/STRONG
STORMS MOVE ESE.
&&
PREVIOUS DISCUSSION...
SEVERE THUNDERSTORM WATCH CONTINUES FOR THE ENTIRE AREA THROUGH 10
PM. LINE OF STRONG STORMS ARE NOW MOVING SLOWLY SE THROUGH NH AND
MAINE. AREA OF OUTFLOW NOW MOVING AHEAD OF THE STORMS IN OXFORD
AND CARROLL COUNTIES MAY EVENTUALLY INTERACT WITH THE SEABREEZE IN
ANDROSCOGGIN/ CUMBERLAND COUNTIES. STRONGER/ SEVERE STORMS ARE
LOCATED IN VT AND MAY MOVE INTO NH IN THE NEXT HOUR OR TWO.
ADDITIONAL DEVELOPMENT ALONG A PRE FRONTAL TROUGH IS SUGGESTED BY
THE HRRR MODEL AHEAD OF THE CURRENT LINE OF STORMS. SO FAR THE LACK
OF MOISTURE AT 700MB IS LIKELY THE REASON FOR STORMS NOT REALIZING
THEIR FULL POTENTIAL TODAY...SOMETHING TO BE THANKFUL FOR. SHOULD
BE ABLE TO DROP THE NORTHERN COUNTIES FROM THE WATCH SHORTLY.
ADJUSTED POPS...MAX TEMPERATURE...DEW POINTS...AND WEATHER GRIDS
FOR THIS UPDATE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
LINGERING SHOWERS ACROSS S AND SE ZONES THROUGH MIDDAY THURS OR
SO...THEN SOME CLEARING TAKES PLACE. A FAIR NIGHT IS IN STORE FOR
THURS NIGHT AS HIGH PRESSURE BUILDS IN.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
A SLOW MOVING LOW PRESSURE SYSTEM WILL AFFECT THE AREA LATER IN
THE WEEKEND INTO EARLY NEXT WEEK WITH OCCASIONAL SHOWERS AND
POSSIBLY SOME THUNDERSTORMS.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/...IFR OR LOWER IN SHOWERS AND
THUNDERSTORMS THROUGH THIS EVENING...THEN IMPROVING CONDITIONS ARE
FORESEEN. MAINLY VFR THU NIGHT AND FRI.
LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...IFR CONDITIONS WITH
SCT SHRA/TSTMS LIKELY TO DEVELOP SATURDAY NGT AND SUNDAY.
&&
.MARINE...
SHORT TERM /THROUGH FRIDAY/...SCA FOR TONIGHT FOR THE OCEAN WATERS FOR
MARGINAL 25 KT GUSTS AND SEAS 4-6 FT. QUIETER WINDS AND SEAS THU
THROUGH FRI.
LONG TERM /FRIDAY THROUGH MONDAY/...WINDS AND SEAS BELOW SCA
LEVELS THRU SATURDAY MORNING THEN SOUTHERLY FLOW INCREASES
POSSIBLY PUSHING WINDS AND SEAS TO SCA LEVELS OVER THE OPEN WATERS
LATE SATURDAY THRU SUNDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT THURSDAY FOR ANZ150-152-
154.
&&
$$
UPDATE...HANES
AREA FORECAST DISCUSSION
NWS CARIBOU ME
327 AM EDT TUE JUL 22 2014
.SYNOPSIS...
HIGH PRESSURE WILL SETTLE SOUTHEAST OF THE REGION INTO TONIGHT. A
COLD FRONT WILL APPROACH FROM THE NORTHWEST ON WEDNESDAY AND CROSS
THE REGION FROM NORTHWEST TO SOUTHEAST LATER WEDNESDAY AFTERNOON
INTO WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
A WARM SUMMER DAY COMING UP!
SOME PATCHY VALLEY FOG POSSIBLE THIS MORNING AND ALONG THE
IMMEDIATE COAST AS SEEN ON THE LATEST GOES E SATELLITE IMAGERY.
MOST OF THE STRATUS AND FOG HANGING ALONG ROCKLAND AND OFFSHORE
ATTM. THE LATEST HRRR SHOWS THE STRATUS AND FOG TO CREEP INTO THE
COASTAL REGIONS THIS MORNING AND HANG ON INTO MID MORNING.
THE LATEST OBS AND SATELLITE SHOWED THAT THE HRRR IS TOO FAST.
THEREFORE BACKED OFF ON KEEPING THE STRATUS AND FOG BEYOND 12Z.
THIS WILL NEED TO BE MONITORED THIS MORNING.
OTHER THAN THAT, HIGH PRES WILL RIDGE ACROSS THE REGION TODAY
W/TEMPERATURES WARMING THROUGH THE COLUMN RIGHT UP THROUGH 500MBS.
THIS WILL TRANSLATE DOWN TO THE BLYR FOR A VERY WARM DAY W/A GOOD
DEAL OF SUNSHINE. TEMPERATURES ARE EXPECTED TO BE AT LEAST 3 TO 5
DEGREES WARMER THAN THEY WERE ON MONDAY. WE ARE TALKING MID TO
POSSIBLY UPPER 80S AWAY FROM THE COAST AS A SW BREEZE KICKS IN.
THE COASTAL AREAS WILL BE COOLER AS THE SSW BREEZE WILL KEEP
THINGS COOLER, BUT STILL ABLE TO HIT AROUND 80F. HUMIDITY WILL BE
ON THE INCREASE THIS AFTERNOON INTO TONIGHT. SKIES FOR THE MOST
PART WILL STAY CLEAR W/SOME STRATUS AND FOG FORMING AGAIN AND
PUSHING A BIT FURTHER INLAND INTO THE INTERIOR DOWNEAST. STAYED
CLOSE TO THE DAYCREW`S ASSESSMENT OF FOG DEVELOPMENT FOR THE
BANGOR AND COASTAL REGION. OVERNIGHT LOWS WILL BE VERY MILD
RUNNING IN THE MID TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
A VIGOROUS COLD FRONT WILL SWEEP ACROSS NORTHERN AND EASTERN MAINE
WEDNESDAY AFTERNOON. SBCAPE VALUES ARE FORECAST TO BE IN THE
1500-2000 J/KG RANGE WITH 90 DCM HEIGHT FALLS IN A 15 HOUR TIME
FRAME. EXPECT A QCLS IN THE MID AFTERNOON THROUGH EVENING WITH
DISCRETE CELLS POSSIBLE AHEAD OF THE LINE. WILL CONTINUE THE
ENHANCED SEVERE WEATHER WORDING IN THE FORECAST.
MUCH COOLER AND DRIER AIR USHERS INTO THE REGION ON THURSDAY BEHIND
THE COLD FRONT. TEMPERATURES WILL BE 10 TO 12 DEGREES COOLER ON
THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
A BROAD UPPER LEVEL TROUGH WILL BE OVER EASTERN CANADA AND THE
NORTHEAST U.S. BY THE END OF THE WEEK. A BRIEF ZONAL FLOW TO START
NEXT WEEK IS REPLACED BY STRONGLY SOUTHWEST FLOW BY MONDAY AS AN
UNSEASONABLY STRONG UPPER TROUGH SETS UP OVER THE GREAT LAKES.
THIS RESULTS IN AN UNSETTLED PATTERN.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: GENERALLY VFR W/THE THREAT FOR IFR FOR KBHB THIS
MORNING. THIS WILL BE MONITORED THROUGH THIS MORNING. THERE IS
POTENTIAL FOR MVFR/IFR FOR BOTH KBGR AND KBHB LATER TONIGHT AS A
SSW FLOW BRINGING LLVL MOISTURE NORTHWARD.
SHORT TERM: MVFR CIGS AND VSBYS ARE LIKELY WED AFTN AND EVE AT ALL
TAF SITES IN THUNDERSTORMS AS A COLD FRONT SWEEPS ACROSS MAINE. VFR
CONDITIONS RETURN FOR WED NGT AND THU.
&&
.MARINE...
NEAR TERM: NO HEADLINES. DECIDED TO MENTION A SOUTHERLY SWELL
TODAY INTO THIS EVENING AS IS EVIDENT ON THE OBS THIS MORNING.
WAVE HEIGHTS WILL BE AROUND 3 FT CREEPING TO 4 FT TONIGHT MAINLY
FOR THE OUTER WATERS. THE WAVE GUIDANCE INCLUDING THE SWAN
GUIDANCE HAS BEEN OVERDOING THE HEIGHTS BY A FOOT. BASED ON THIS,
DECIDED TO CUT BACK THE HEIGHTS BY A FOOT INTO TONIGHT. WINDS WILL
GRADUALLY PICK UP LATER TODAY INTO TONIGHT BUT STILL WELL BELOW 20
KT.
SHORT TERM: SCA MAY BE NEEDED WEDNESDAY AFTERNOON AND EVENING
WITH WAVE HEIGHTS 4-6 FEET AND WIND GUSTS AROUND 25 KNOTS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...OKULSKI
LONG TERM...OKULSKI
AVIATION...HEWITT/OKULSKI
MARINE...HEWITT/OKULSKI
AREA FORECAST DISCUSSION
NWS CARIBOU ME
102 AM EDT TUE JUL 22 2014
.SYNOPSIS...
HIGH PRESSURE SETTLES SOUTHEAST OF THE REGION OVERNIGHT. A COLD
FRONT WILL APPROACH FROM THE NORTH TUESDAY NIGHT...THEN CROSS THE
REGION NORTHWEST TO SOUTHEAST WEDNESDAY AFTERNOON THROUGH
WEDNESDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
1255 AM UPDATE...BROUGHT STRATUS THAT IS RESIDING OVER THE GULF OF
MAINE IN ALONG THE HANCOCK AND WASHINGTON COUNTY COAST. THE LATEST
RUN OF THE HRRR 3KM HAD THIS HANDLED OK BUT A BIT QUICK. THEREFORE,
BACKED THE TIMING BACK BY ABOUT 2 HRS. BROUGHT HR LY TEMPERATURES
IN LINE W/THE CURRENT READINGS.
PREVIOUS DISCUSSION...
LATEST SAT IMAGERY DOES SHOW THE DEEPEST CU OVR WRN PTNS OF THE FA
AS OF MID THIS AFTN...SO WE WILL LEAVE A MENTION OF ISOLD SHWRS
OVR THIS PTN OF THE FA INTO ERLY EVE...BUT SHWRS AND DEEP CU CLDS
SHOULD MSLY DISSIPATE AFT SUNSET...LEAVING MCLR SKIES ACROSS ALL OF
THE FA OVRNGT. WITH FCST LOWS XPCTD TO REACH OR EVEN FALL BLO
CURRENT OBSVD DWPTS OVR VLY LCTNS LATE TNGT/ERLY TUE MORN...WE
CANNOT RULE OUT PATCHY VLY FOG DURG THESE HRS..WHICH WE MENTIONED.
OTHERWISE...TUE LOOKS TO BE MSLY AND WARMER AS 500 MB HTS CONT TO
RISE WITH A BUILDING S/WV RIDGE OVR NEW ENG. WITH A WSW SFC WIND
THIS SHOULD RESULT IN ABOUT A 3 DEG C WRMG OF 925MB TEMPS AND A
CORRESPONDING 5 DEG F INCREASE IN HI TEMPS TUE AFTN OVR THIS AFTN.
LCTNS ALG THE IMMEDIATE COAST WILL BE A LITTLE COOLER TUE AFTN...
WITH WINDS BCMG MORE SRLY WITH A SHALLOW AND LMTD INLAND SEA BREEZE
BY MID TO LATE AFTN.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
THE MAIN CONCERN FOR THE SHORT TERM WILL BE THE SEVERE WEATHER
THREAT FOR WEDNESDAY IN ASSOCIATION WITH A COLD FRONT. AHEAD OF
THIS FRONT, A SW FLOW WILL RESULT IN A WARM AND MUGGY NIGHT FOR
TUESDAY NIGHT WITH LOWS NOT GETTING BELOW THE MID TO UPPER 60S
ACROSS MUCH OF THE FORECAST AREA. LOCALS RIGHT ALONG WITH COAST
AND ACROSS THE FAR NORTHWEST WILL BE JUST A BIT COOLER. ALSO
EXPECT SOME FOG DOWNEAST FOR TUESDAY NIGHT AS A RESULT OF THE
WARM, MUGGY AIRMASS BEING ADVECTED OVER THE COOLER WATER THEN
INTO THE COASTAL ZONES.
WEDNESDAY WILL BEGIN FAIR WITH HIGHS FOR MOST AREAS CLIMBING WELL
INTO THE 80S TO NEAR 90 BY EARLY AFTERNOON ALONG WITH HIGH
HUMIDITY. HOWEVER A COLD FRONT MOVING IN FROM THE NORTHWEST WILL
TRIGGER THUNDERSTORMS BEGINNING BY EARLY AFTERNOON ACROSS THE
CROWN OF MAINE WITH SHOWERS/THUNDERSTORMS PROGRESSING SOUTH AND
EAST THROUGH THE REMAINDER OF THE DAY AND REACHING THE COAST BY
EVENING. FORECAST CONFIDENCE IS GROWING THAT AT LEAST SOME OF
THESE STORMS ARE LIKELY TO BE STRONG TO SEVERE AS FORECAST
GUIDANCE DEPICTS SB CAPES IN THE 1000-2000+ J/KG RANGE WITH 0-6 KM
SHEAR VALUES OF 30-35 KNOTS...CLOSE TO THE THRESHOLD FOR SOME OF
THESE STORMS TO CONTAIN ROTATION. SOME LOW LEVEL DIRECTIONAL SHEAR
CAN ALSO BE NOTED IN THE FORECAST PROFILES AS WELL. FINALLY,
DEPENDING HOW QUICKLY THE UPPER LEVEL TROUGH IN ASSOCIATION WITH
THIS SYSTEM DEEPENS AND COLDER AIR ALOFT WRAPS IN, MID LEVEL LAPSE
RATES ALSO HAVE THE POTENTIAL TO BE FAIRLY STEEP. THUS, ORGANIZED
MULTICELL CONVECTION EXPECTED FOR WEDNESDAY AFTERNOON INTO THE
EARLY EVENING WITH STRONG AND POTENTIALLY DAMAGING WINDS THE
BIGGEST THREAT ALTHOUGH CAN`T RULE OUT LARGE HAIL IN ADDITION TO
HEAVY RAIN DUE TO HIGH CAPES AND PWATS. HOWEVER THE PROGRESSIVE
NATURE OF THE SYSTEM SHOULD HELP LIMIT ANY HYDRO ISSUES.
SHOWERS AND STORMS WILL DIMINISH ACROSS MOST OF THE AREA THROUGH THE
EVENING AS THE FRONT PUSHES SOUTH AND ALSO DUE TO THE LOSS OF
DAYTIME HEATING. HOWEVER DO EXPECT THE FRONT TO SLOW DOWN AS IT
REACHES THE COAST AND THIS COULD KEEP SHOWERS GOING A BIT LONGER
ALONG THE COAST. ANY LINGERING COASTAL SHOWERS DIMINISH THURSDAY
MORNING WITH OTHERWISE FAIR AND MUCH COOLER AND DRIER WEATHER
EXPECTED FOR THURSDAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
EXPECT A TREND TOWARD COOLER AND OVERALL MORE UNSETTLED CONDITIONS
IN THE LONG RANGE AS AN UPPER TROUGH SETS UP IN THE EAST. FAIR AND
COMFORTABLE CONDITIONS THURSDAY NIGHT WILL GIVE WAY TO THE CHANCE
FOR SOME SHOWERS DEVELOPING BY FRIDAY AFTERNOON IN THE NORTH AS AN
OCCLUDED FRONT MOVES SOUTH. ANY SHOWERS DIMINISH FRIDAY NIGHT WITH
MORE SCATTERED SHOWERS POTENTIALLY DEVELOPING BY SATURDAY
AFTERNOON DUE TO THE UPPER LEVEL TROUGH AND DAYTIME HEATING. ANY
SHOWERS AGAIN DIMINISH SATURDAY NIGHT WITH THE POTENTIAL FOR MORE
WIDESPREAD SHOWERS BY LATER SUNDAY INTO MONDAY AS GUIDANCE
INDICATES SURFACE LOW DEVELOPMENT IN THE VICINITY OF THE EASTERN
GREAT LAKES INTO THE NORTHEAST IN ASSOCIATION WITH THE PERSISTING
TROUGH ALOFT.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: VFR THROUGH TUE...EXCEPT PERHAPS A BRIEF PD OF MVFR OR
IFR VSBYS LATE TNGT IN PATCHY VLY FOG SPCLY KPQI...KHUL AND KBGR.
OFFSHORE STRATUS MAY PRODUCE A PERIOD OF IFR CEILINGS AT KBHB VERY
LATE TONIGHT INTO EARLY TUE MORNING.
SHORT TERM: MVFR/IFR WILL BE A CONCERN FOR THE SOUTHERN SITES
TUESDAY NIGHT DUE TO COASTAL FOG WITH THE NORTHERN SITES REMAINING
VFR.WEDNESDAY LOOKS TO BE AN ACTIVE DAY W/THE POTENTIAL FOR
STRONG TO SEVERE THUNDERSTORMS AND LLWS. MVFR AND BRIEF IFR
CONDITIONS LIKELY IN THE AFTERNOON INTO THE EVENING WITH THESE
SHOWER/STORMS. MVFR/IFR MAY LINGER INTO WEDNESDAY NIGHT FOR THE
SOUTHERN SITES WITH ALL SITES BECOMING VFR FOR THURSDAY AND
FRIDAY.
&&
.MARINE...
NEAR TERM: NO HDLNS XPCTD THRU THE NEAR TERM...WITH WVS SLOWLY
BUILDING TOWARD 4 FT OVR OUTERMOST WATERS WITH AN INCREASING SSW
WIND FETCH BY LATE TUE AFTN.
SHORT TERM:
EXPECT SOME FOG TUESDAY NIGHT INTO EARLY WEDNESDAY AS WARM, MOIST
AIR MOVES IN OVER THE COOLER WATER. OTHERWISE WINDS/SEAS WILL
INCREASE TUESDAY NIGHT INTO WEDNESDAY AHEAD OF A COLD FRONT WITH
SEAS HITTING 4-6 FT AND WINDS GUSTING TO AROUND 25 KNOTS. THESE
CONDITIONS DIMINISH LATER WEDNESDAY NIGHT INTO THURSDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...HEWITT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
155 PM EDT TUE JUL 22 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 AM EDT TUE JUL 22 2014
IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL
MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EDT TUE JUL 22 2014
NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN
FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS
AFTERNOON INTO THE EARLY OVERNIGHT HOURS.
QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS
EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER
FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER
OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR
AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD.
WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A
DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD
SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY
AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN
U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR
AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS
AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY
DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN
GREATLY CAPPED THROUGH MID AFTERNOON.
MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE
1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND
SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER
INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER
DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS
SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT
CONVECTION OVER THE AREA.
WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE
AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE
THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS
TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION
PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST
INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT
EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE
WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING
THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY
THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT
THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND
0-1KM HELICITY VALUES 150+ M2/S2.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT.
IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW
WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS
AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT
SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO
TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT
ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA.
HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR
FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT
AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR
FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED
SHOWERS AND STORMS.
ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY
EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY
WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS
HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST
AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL
TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE
FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR
CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY
AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE.
HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY
AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY
HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL
SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL
NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER
QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE
WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER
LOW/MARGINAL.
IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS
ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY
SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND
TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO
SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE
SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA
TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY
OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED
TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT.
A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD
AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS
PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES
BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 154 PM EDT TUE JUL 22 2014
VFR CONDITIONS IN PLACE AREA WIDE AT 18Z...WHICH WILL CONTINUE
THROUGH THE REMAINDER OF THE AFTERNOON. THE FOCUS IS ON THE
EXTENT OF THUNDERSTORM DEVELOPMENT THIS EVENING. ESSENTIALLY
EXPECTING SCATTERED THUNDERSTORMS TO DEVELOP AND SINK SOUTH THROUGH
THE TAF SITES BETWEEN 22Z AND 06Z. BEST CHANCE FOR STORMS WILL BE
AT KMKG...KGRR AND KAZO...WITH SLIGHTLY LESSER CHANCES INLAND. AT
THIS POINT NOT CONFIDENT ENOUGH TO GO PREVAILING STORMS AT ANY
GIVEN LOCATION SO USED VCTS WORDING THROUGH THE EVENING TIME
FRAME. SOME STORMS MAY CONTAIN STRONG GUSTY WINDS IN EXCESS OF 35
KNOTS.
OVERNIGHT...THE THREAT EXISTS FOR A MVFR CLOUD DECK TO SETTLE INTO
THE TAF SITES ON NORTHERLY WINDS BEHIND A COLD FRONT. AT THIS
POINT USED SCATTERED WORDING AT 1500FT TO CONVEY THE CHANCE OF
THIS DECK DEVELOPING. A CHANCE AT SOME MVFR FOG FOR A TIME
OVERNIGHT AS WELL WITH HIGH DEW POINT AIR IN PLACE. SKIES SHOULD
GRADUALLY CLEAR/SCATTER OUT ON WEDNESDAY AS DRIER AIR WORKS IN
FROM THE NORTH. SOME MODELS INDICATE A MVFR DECK HOLDING ON ACROSS
MUCH OF THE AREA THOUGH THROUGH WEDNESDAY MORNING.
&&
.MARINE...
ISSUED AT 1145 AM EDT TUE JUL 22 2014
BEACH HAZARDS EVENT UNDERWAY AND GOING DOWN AS EXPECTED THUS FAR.
THE LUDINGTON BUOY IS CURRENTLY SHOWING 4.6 FOOT WAVES AND THE
WEBCAM THERE IS SHOWING SOME PRETTY BIG WAVES AT TIMES SMACKING
THE SOUTH BREAKWALL. HOFFMASTER STATE PARK HAD 4 FOOTERS IN THEIR
MORNING BEACH OB. IN LOOKING AT THE GRAND HAVEN WEBCAM FEELING OK
WHERE WE HAVE THE BREAK IN THE SMALL CRAFT ADVISORY AND BEACH
HAZARDS STATEMENT...WHICH IS JUST NORTH OF GRAND HAVEN. THE NORTHERN
PORTIONS OF THE OTTAWA ZONE (GRAND HAVEN) WILL BE BORDERLINE THIS
AFTERNOON WITH WAVES HOVERING AROUND THE 2-4 FOOT RANGE.
HAVE OPTED TO JUMP INTO THE NORTH FLOW PORTION OF THE EVENT NOW AS
WELL. HAVE EXTENDED THE NORTHERN HALF OF THE MARINE PRODUCTS
SCA/BHS THROUGH TOMORROW EVENING. IN THE SOUTH HALF HAVE THEM
STARTING UP AT 06Z TONIGHT AND LASTING THROUGH WEDNESDAY NIGHT AS
THE FLOW COMES AROUND TO THE NORTH.
IN TERMS OF BEACH IMPACT TODAY/S EVENT IN THE NORTH HALF OF THE
MARINE AREA MAY BE THE HIGHER THREAT GIVEN THE WARM TEMPS...AND
THEREFORE A LARGER BEACH POPULATION. TOMORROW/S WAVES WILL BE
BIGGER BUT THE IMPACT MAY BE MITIGATED BY COOLER BEACH
TEMPERATURES...RESULTING IN LESS FOLKS ON THE BEACH AND IN THE
WATER.
&&
.HYDROLOGY...
ISSUED AT 334 PM EDT MON JUL 21 2014
WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND
WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS
OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER
THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL
WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION
ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS
HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME
LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY
MORNING FOR MIZ056-064-071.
BEACH HAZARDS STATEMENT THROUGH LATE WEDNESDAY NIGHT FOR MIZ037-
043-050.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR LMZ847>849.
SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR LMZ844>846.
&&
$$
UPDATE...NJJ
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...DUKE
HYDROLOGY...HOVING
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1145 AM EDT TUE JUL 22 2014
LATEST UPDATE...
MARINE
.SYNOPSIS...
ISSUED AT 325 AM EDT TUE JUL 22 2014
IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL
MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EDT TUE JUL 22 2014
NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN
FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS
AFTERNOON INTO THE EARLY OVERNIGHT HOURS.
QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS
EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER
FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER
OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR
AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD.
WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A
DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD
SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY
AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN
U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR
AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS
AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY
DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN
GREATLY CAPPED THROUGH MID AFTERNOON.
MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE
1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND
SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER
INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER
DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS
SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT
CONVECTION OVER THE AREA.
WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE
AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE
THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS
TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION
PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST
INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT
EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE
WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING
THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY
THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT
THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND
0-1KM HELICITY VALUES 150+ M2/S2.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT.
IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW
WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS
AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT
SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO
TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT
ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA.
HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR
FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT
AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR
FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED
SHOWERS AND STORMS.
ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY
EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY
WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS
HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST
AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL
TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE
FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR
CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY
AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE.
HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY
AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY
HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL
SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL
NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER
QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE
WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER
LOW/MARGINAL.
IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS
ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY
SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND
TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO
SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE
SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA
TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY
OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED
TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT.
A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD
AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS
PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES
BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 750 AM EDT TUE JUL 22 2014
THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING
SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST
LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG.
THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD
TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE
STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION
SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY.
A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT
MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS
NEAR 70 AHEAD OF THE APCHG COLD FRONT.
STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS
WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT
BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES...
ESPECIALLY AT MKG.
&&
.MARINE...
ISSUED AT 1145 AM EDT TUE JUL 22 2014
BEACH HAZARDS EVENT UNDERWAY AND GOING DOWN AS EXPECTED THUS FAR.
THE LUDINGTON BUOY IS CURRENTLY SHOWING 4.6 FOOT WAVES AND THE
WEBCAM THERE IS SHOWING SOME PRETTY BIG WAVES AT TIMES SMACKING
THE SOUTH BREAKWALL. HOFFMASTER STATE PARK HAD 4 FOOTERS IN THEIR
MORNING BEACH OB. IN LOOKING AT THE GRAND HAVEN WEBCAM FEELING OK
WHERE WE HAVE THE BREAK IN THE SMALL CRAFT ADVISORY AND BEACH
HAZARDS STATEMENT...WHICH IS JUST NORTH OF GRAND HAVEN. THE NORTHERN
PORTIONS OF THE OTTAWA ZONE (GRAND HAVEN) WILL BE BORDERLINE THIS
AFTERNOON WITH WAVES HOVERING AROUND THE 2-4 FOOT RANGE.
HAVE OPTED TO JUMP INTO THE NORTH FLOW PORTION OF THE EVENT NOW AS
WELL. HAVE EXTENDED THE NORTHERN HALF OF THE MARINE PRODUCTS
SCA/BHS THROUGH TOMORROW EVENING. IN THE SOUTH HALF HAVE THEM
STARTING UP AT 06Z TONIGHT AND LASTING THROUGH WEDNESDAY NIGHT AS
THE FLOW COMES AROUND TO THE NORTH.
IN TERMS OF BEACH IMPACT TODAY/S EVENT IN THE NORTH HALF OF THE
MARINE AREA MAY BE THE HIGHER THREAT GIVEN THE WARM TEMPS...AND
THEREFORE A LARGER BEACH POPULATION. TOMORROW/S WAVES WILL BE
BIGGER BUT THE IMPACT MAY BE MITIGATED BY COOLER BEACH
TEMPERATURES...RESULTING IN LESS FOLKS ON THE BEACH AND IN THE
WATER.
&&
.HYDROLOGY...
ISSUED AT 334 PM EDT MON JUL 21 2014
WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND
WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS
OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER
THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL
WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION
ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS
HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME
LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM LATE TONIGHT THROUGH THURSDAY
MORNING FOR MIZ056-064-071.
BEACH HAZARDS STATEMENT THROUGH LATE WEDNESDAY NIGHT FOR MIZ037-
043-050.
LM...SMALL CRAFT ADVISORY UNTIL 2 AM EDT THURSDAY FOR LMZ847>849.
SMALL CRAFT ADVISORY FROM 2 AM WEDNESDAY TO 8 AM EDT THURSDAY
FOR LMZ844>846.
&&
$$
UPDATE...NJJ
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...DUKE
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1115 AM EDT TUE JUL 22 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 325 AM EDT TUE JUL 22 2014
IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL
MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK.
&&
.UPDATE...
ISSUED AT 1115 AM EDT TUE JUL 22 2014
NO MAJOR CHANGES TO THE GOING FCST FOR TODAY AND TONIGHT. OUR MAIN
FOCUS IS ON CONVECTIVE POTENTIAL AND SEVERE THREAT FOR LATE THIS
AFTERNOON INTO THE EARLY OVERNIGHT HOURS.
QUIET WEATHER ACROSS THE ENTIRE CWFA THIS MORNING...AND THIS IS
EXPECTED TO CONTINUE INTO MID AFTERNOON. BAND OF CLOUDS LEFT OVER
FROM CONVECTION OUT WEST LAST NIGHT IS MOVING INTO THE NW CORNER
OF THE CWFA. THIS IS MAINLY MID LEVEL CLOUD COVER PER THE RADAR
AND SFC OBS. NOT MUCH INSTABILITY HAS DEVELOPED YET OVERHEAD.
WE CONTINUE TO EXPECT THAT THE NW CORNER OF THE CWFA WILL SEE A
DECENT CHC OF CONVECTION AFTER AROUND 21Z OR SO...AND THEN SPREAD
SOUTH AND EAST THROUGH THE AREA THEREAFTER. THE MAIN INSTABILITY
AXIS IS IMMEDIATELY AHEAD OF THE SFC FRONT LOCATED FROM THE WRN
U.P. TO NE IA AS OF 15Z THIS MORNING. THIS WILL SHIFT INTO OUR
AREA AS THE LLJ/MAIN MOISTURE TRANSPORT SLIDES IN LATER THIS
AFTERNOON AND THIS EVENING. WE WILL SEE SOME DIURNAL INSTABILITY
DEVELOP OVERHEAD BEFORE THAT TIME...HOWEVER IT WILL REMAIN
GREATLY CAPPED THROUGH MID AFTERNOON.
MODEL CONSENSUS SHOWS THAT THE WRN AREAS OF THE CWFA SHOULD SEE
1500-2000 J/KG OF ML AND MU CAPE NOSE INTO THE AREA BY 00Z AND
SHIFT SOUTH OF THE AREA BY 06Z VIA AN ELEVATED MIXED LAYER. THE BETTER
INSTABILITY IS DEFINITELY WEST OF THE AREA...AND THE BETTER
DYNAMICS REMAIN NORTH OF THE AREA. WE DO SEE A SHORT WAVE ACROSS
SD THAT APPROACHES THIS EVENING AND WILL LIKELY HELP TO SUPPORT
CONVECTION OVER THE AREA.
WE BELIEVE THAT THE SEVERE THREAT REMAINS POSSIBLE ACROSS THE
AREA...ESPECIALLY ACROSS THE WRN HALF OF THE CWFA SIMILAR TO THE
THINKING OF SPC PER THE SWODY1 OUTLOOK. DEEP LAYER SHEAR HAS
TRENDED MORE FAVORABLE DURING THE EXPECTED TIME OF CONVECTION
PEAKING AT AROUND 30-35 KNOTS...HIGHEST WEST WHERE THE BEST
INSTABILITY WILL BE OVER THE AREA. LOW LEVEL INVERSION HEIGHTS ARE NOT
EXPECTED TO BE ALL THAT HIGH...SO A WIND THREAT WILL BE POSSIBLE
WITH 40 KNOTS IN THE MID LEVELS AND A 30+ KNOT LLJ PRESENT DURING
THE TIME OF CONVECTION. LARGE HAIL WILL BE POSSIBLE WITH FAIRLY
THICK CAPE IN THE -10C TO -30C LAYER. WE ALSO AGREE WITH SPC ABOUT
THE POSSIBILITY OF A TORNADO WITH 0-1KM SHEAR OF 20-25 KNOTS AND
0-1KM HELICITY VALUES 150+ M2/S2.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT.
IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW
WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS
AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT
SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO
TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT
ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA.
HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR
FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT
AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR
FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED
SHOWERS AND STORMS.
ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY
EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY
WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS
HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST
AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL
TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE
FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR
CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY
AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE.
HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY
AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY
HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AREA. UPPER LEVEL
SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL
NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER
QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE
WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER
LOW/MARGINAL.
IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS
ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY
SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND
TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO
SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE
SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA
TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY
OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED
TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT.
A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD
AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS
PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES
BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 750 AM EDT TUE JUL 22 2014
THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING
SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST
LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG.
THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD
TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE
STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION
SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY.
A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT
MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS
NEAR 70 AHEAD OF THE APCHG COLD FRONT.
STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS
WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT
BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES...
ESPECIALLY AT MKG.
&&
.MARINE...
ISSUED AT 325 AM EDT TUE JUL 22 2014
A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN
EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH
3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH
OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL
OCCUR FROM MID MORNING THROUGH MID EVENING.
ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY
BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD
FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN.
&&
.HYDROLOGY...
ISSUED AT 334 PM EDT MON JUL 21 2014
WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND
WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS
OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER
THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL
WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION
ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS
HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME
LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ847>849.
&&
$$
UPDATE...NJJ
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
751 AM EDT TUE JUL 22 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 325 AM EDT TUE JUL 22 2014
IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL
MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT.
IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW
WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS
AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT
SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO
TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT
ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA.
HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR
FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT
AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR
FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED
SHOWERS AND STORMS.
ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY
EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY
WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS
HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST
AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL
TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE
FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR
CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY
AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE.
HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY
AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY
HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AERA. UPPER LEVEL
SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL
NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER
QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE
WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER
LOW/MARGINAL.
IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS
ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY
SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND
TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO
SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE
SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA
TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY
OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED
TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT.
A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD
AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS
PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES
BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 750 AM EDT TUE JUL 22 2014
THE PRIMARY AVIATION CONCERN FOR TODAY WILL BE THE INCREASING
SOUTHWEST SFC WINDS WHICH WILL BE GUSTING TO 20-25 KNOTS AT MOST
LOCATIONS BY NOON. STRONGEST GUSTS SHOULD BE AT MKG.
THE FOCUS THIS EVENING FOR THE TERMINALS WILL BE THE LINE OF SCTD
TSTMS WHICH MOVES SOUTHEAST THROUGH SRN LWR MI FROM 23Z-06Z. THE
STORMS WILL IMPACT MKG FIRST AND JXN LAST... BUT ANY ONE LOCATION
SHOULD ONLY SEE ABOUT A 2-4 HOUR WINDOW OF TSTMS IN THE VICINITY.
A BRIEF PERIOD OF IFR IS POSSIBLE WITH ANY TSTM OTHERWISE LIGHT
MVFR FOG/HAZE EXPECTED THIS EVENING DUE TO THE HIGH DEW POINTS
NEAR 70 AHEAD OF THE APCHG COLD FRONT.
STORMS WILL EXIT BY 06Z... BUT THE POTENTIAL FOR SOME MVFR CIGS
WILL DEVELOP AFTER 09Z. SFC WINDS WILL SHIFT TO THE NORTH TONIGHT
BEHIND THE COLD FRONT AND WILL PROBABLY REMAIN GUSTY AT TIMES...
ESPECIALLY AT MKG.
&&
.MARINE...
ISSUED AT 325 AM EDT TUE JUL 22 2014
A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN
EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH
3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH
OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL
OCCUR FROM MID MORNING THROUGH MID EVENING.
ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY
BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD
FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN.
&&
.HYDROLOGY...
ISSUED AT 334 PM EDT MON JUL 21 2014
WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND
WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS
OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER
THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL
WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION
ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS
HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME
LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR MIZ037-043-050.
LM...SMALL CRAFT ADVISORY UNTIL 11 PM EDT THIS EVENING FOR LMZ847>849.
&&
$$
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...HOVING
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
325 AM EDT TUE JUL 22 2014
LATEST UPDATE...
SYNOPSIS/SHORT TERM/LONG TERM/MARINE
.SYNOPSIS...
ISSUED AT 325 AM EDT TUE JUL 22 2014
IT WILL BE VERY WARM AND QUITE HUMID TODAY. A COLD FRONT WILL
BRING SCATTERED SHOWERS AND THUNDERSTORMS LATE THIS AFTERNOON
AND TONIGHT. A SIGNIFICANTLY COOLER AND DRIER AIR MASS WILL
MOVE IN BEHIND THAT FRONT FOR MID TO LATE WEEK.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
OUR PRIMARY SHORT TERM FCST CHALLENGE IS TO DETERMINE
CONVECTIVE/SEVERE WX POTENTIAL THIS AFTERNOON THROUGH TONIGHT.
IT WILL BE HOT AND HUMID TODAY WITH SOME SUN AND STRONG SSW FLOW
WAA HELPING TO BOOST MAX TEMPS INTO THE 85 TO 90 DEGREE RANGE THIS
AFTERNOON WITH DEW POINTS REACHING THE MID TO UPPER 60S. WE EXPECT
SEVERE CONVECTION OVER MN AND EXTREME NW WI EARLY THIS MORNING TO
TRACK ACROSS FAR NORTHERN WI AND THE U.P. THIS MORNING. HOWEVER THAT
ACTIVITY WILL STAY WELL TO THE NW OF OUR FCST AREA.
HOWEVER WE EXPECT A FEW SHOWERS AND TSTORMS TO DEVELOP OVER OUR
FAR NW FCST AREA BY LATE AFTN AS THE COLD FRONT MOVES INTO THAT
AREA. THE COLD FRONT WILL THEN MOVE QUICKLY ACROSS THE REST OF OUR
FCST AREA DURING THE MID TO LATE EVENING HOURS BRINGING SCATTERED
SHOWERS AND STORMS.
ISOLATED STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE MAINLY
EARLY TO MID EVENING COINCIDENT WITH PEAK OR NEAR PEAK INSTABILITY
WITH POTENTIAL FOR SB/ML CAPE VALUES TO BRIEFLY REACH UP TO AS
HIGH AS 2000 J/KG FOR A SMALL PORTION OF OUR SOUTHWESTERN FCST
AREA. SHORT RANGE GUIDANCE HAS ALSO TRENDED FASTER WITH FRONTAL
TIMING THE PAST 24 HRS WHICH IS ALSO POTENTIALLY MORE FAVORABLE
FOR A FEW STRONGER STORMS. THE MOST LIKELY TIME FRAME FOR
CONVECTION IS FROM AROUND 23Z THIS EVENING THROUGH 05Z WEDNESDAY
AS SUGGESTED BY 00Z 4KM NSSL WRF AND LATEST HRRR SIM Z GUIDANCE.
HOWEVER IT IS NOTED THAT 0-6 KM BULK SHEAR IS WEAK AND MAINLY ONLY
AROUND 20-25 KTS OFF LATEST SREF GUIDANCE... ALTHOUGH VERY BRIEFLY
HIGHER VALUES ARE NOTED OVER OUR FAR NW FCST AERA. UPPER LEVEL
SUPPORT FOR MORE ORGANIZED CONVECTIVE DEVELOPMENT PASSES BY WELL
NORTH OF OUR FCST AREA. INSTABILITY IS FCST TO DIMINISH RATHER
QUICKLY FROM MID TO LATE EVENING. SO THE OVERALL THREAT FOR SEVERE
WX LATE THIS AFTERNOON THROUGH THE LATE EVENING HOURS IS RATHER
LOW/MARGINAL.
IT WILL BE BREEZY AND MUCH COOLER/DRIER WEDNESDAY WITH MAX TEMPS
ONLY REACHING THE 70S. SKIES WILL CLEAR WEDNESDAY NIGHT AS HIGH
PRESSURE BUILDS IN FROM THE NW. HIGH PRESSURE WILL PRODUCE MOSTLY
SUNNY SKIES THURSDAY WITH MAX TEMPS IN THE MID TO UPPER 70S.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 325 AM EDT TUE JUL 22 2014
THE MAIN CHALLENGE WITH THE LONG TERM FORECAST IS THE SHOWER AND
TSTM POTENTIAL OVER THE COMING WEEKEND. GUIDANCE CONTINUES TO
SUGGEST THAT THE PRIMARY CORRIDOR OF HEAVIER MCS ACTIVITY WILL BE
SOUTHWEST/SOUTH OF MICHIGAN FRIDAY THROUGH SUNDAY... FROM ERN IOWA
TO INDIANA. HOWEVER WE MAY STILL BE IMPACTED BY THE NRN PERIPHERY
OF THESE CONVECTIVE COMPLEXES WITH PERIODS OF SHOWERS AND SCATTERED
TSTMS...AIDED BY WEAK SHORTWAVES IN THE FAST W/NW FLOW ALOFT.
A RATHER POTENT LOOKING SHORTWAVE IS PROGGED TO DROP DOWN FROM THE
NORTHWEST SUNDAY NIGHT AND MONDAY... AND THE GFS/ECMWF ARE IN GOOD
AGREEMENT ON THIS FEATURE. BEST POPS WILL EXIST DURING THIS
PERIOD... FOLLOWED BY HIGH CONFIDENCE BELOW NORMAL TEMPERATURES
BEHIND THIS SYSTEM FOR MOST OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1125 PM EDT MON JUL 21 2014
HAZE WILL BE ON THE INCREASE AS A HUMID AIRMASS SPREADS IN FROM
THE WEST TONGHT AND TUESDAY. WHILE THE UPSTREAM THUNDERSTORMS ARE
FORECASTED TO WEAKEN AS THE TRACK THROUGH WI TONIGHT...THE CHANCE
OF THEM MAKING IT TO MI IS NOT ZERO. THEY WILL HAVE TO BE
MONITORED OVERNIGHT. A BETTER RISK FOR STORMS AND IMPACTS EXISTS
GENERALLY AFTER 22Z ON TUESDAY. A COLD FRONT WILL BE NEARING FROM
THE NORTHWEST THEN.
&&
.MARINE...
ISSUED AT 325 AM EDT TUE JUL 22 2014
A SMALL CRAFT ADVISORY AND BEACH HAZARDS STATEMENT CONTINUES IN
EFFECT FROM GRAND HAVEN NORTHWARD TODAY. WAVE HEIGHTS SHOULD REACH
3 TO 5 FEET WITH HIGHEST WAVES WITHIN THAT RANGE ANTICIPATED NORTH
OF KMKG UP TOWARD THE POINTS. STRONGEST WINDS/HIGHEST WAVES WILL
OCCUR FROM MID MORNING THROUGH MID EVENING.
ANOTHER SMALL CRAFT AND BEACH HAZARDS STATEMENT WILL EVENTUALLY
BE NEEDED FOR WEDNESDAY FOR STRONG NORTHERLY FLOW BEHIND THE COLD
FRONT. THE HIGHEST WAVES WEDNESDAY WILL OCCUR SOUTH OF GRAND HAVEN.
&&
.HYDROLOGY...
ISSUED AT 334 PM EDT MON JUL 21 2014
WIDESPREAD SIGNIFICANT RAINFALL LOOKS UNLIKELY TUESDAY NIGHT AND
WEDNESDAY. GENERALLY WE ARE EXPECTING A QUARTER TO THREE QUARTERS
OF AN INCH OF RAINFALL WITH HIGHER AMOUNTS POSSIBLE IN HEAVIER
THUNDERSTORMS. NOT ALL LOCATIONS ARE EXPECTED TO RECEIVE RAINFALL
WITH THIS COLD FRONT. WITH A FAIRLY QUICK MOVING LINE OF CONVECTION
ALONG THE FRONT...FLOODING IS A GREATLY MITIGATED THREAT. RIVERS
HAVE BEEN FALLING STEADILY AND ASIDE FROM A TEMPORARY BUMP IN SOME
LEVELS ON WEDNESDAY THIS TREND SHOULD CONTINUE FOR THE REST OF THE
WEEK.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...BEACH HAZARDS STATEMENT FROM 10 AM EDT THIS MORNING THROUGH
THIS EVENING FOR MIZ037-043-050.
LM...SMALL CRAFT ADVISORY FROM 10 AM THIS MORNING TO 11 PM EDT THIS
EVENING FOR LMZ847>849.
&&
$$
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...MEADE
AVIATION...MJS
HYDROLOGY...HOVING
MARINE...LAURENS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
914 PM CDT WED JUL 23 2014
.UPDATE...KEPT CHANCES OF SHOWERS AND STORMS GOING FOR MUCH OF THE
REGION THROUGH MIDNIGHT. ADDED ISOLATED SHOWERS INTO THE EARLY
MORNING HOURS AND ALSO ADDED PATCHY FOG FOR MANY AREAS TOWARD
DAYBREAK. /BB/
&&
.DISCUSSION...BEEN AN INTERESTING LATE AFTERNOON AND EVENING WITH
CONVECTION WAITING TO RAMP UP IN COVERAGE AND INTENSITY ABNORMALLY
LATE IN THE DAY. OH YEA...WE ALSO CONFIRMED A RARE WATERSPOUT OVER
THE ROSS BARNETT RESERVOIR.
EDGE OF ARRIVING UPPER LEVEL IMPULSE HELPING BOOST ACTIVITY WAS
RESPONSIBLE FOR A LARGE AND INTENSE THUNDERSTORM COMPLEX PUSHING
THROUGH THE ARKLATEX...BUT AROUND HERE ISOLATED TO SCATTERED
ACTIVITY HAS NOT BEEN NEARLY AS FOCUSED ALTHOUGH SLOW TO DIMINISH
AFTER THE SETTING OF THE SUN. LATEST RUC ANALYSIS DEPICTS WEAK BUT
DEEP MOISTURE CONVERGENCE OVER THE NORTHWEST TWO-THIRDS OF THE CWA
OCCURRING PRESENTLY...AS H850 FLOW IMPINGES FROM THE NORTHWEST IN
ADVANCE OF A SURFACE BOUNDARY EXPECTED TO SLIDE IN FROM THE NORTH
TOMORROW. ALTHOUGH 00Z JAN SOUNDING REVEALED INSTABILITY NOT
TERRIBLY HIGH THE PRECIPITABLE WATER VALUES NEAR 2 INCHES CERTAINLY
ENOUGH TO FUEL HEAVY DOWNPOURS. ANTICIPATING THE DIURNAL WANE IN
INSTABILITY SHOULD BE ENOUGH TO BRING THUNDERSTORMS AND HEAVY
DOWNPOURS MOSTLY TO AN END BY MIDNIGHT ALTHOUGH A FEW SHOWERS COULD
PERSIST INTO THE EARLY MORNING. UNTIL MIDNIGHT THE SLOW MOVING AND
BACKBUILDING NATURE OF SOME STORMS WILL HAVE TO BE MONITORED CLOSELY
BECAUSE OF LOCALLY HEAVY RAIN POTENTIAL. TOWARD SUNRISE ENOUGH
CLEARING SHOULD OCCUR TO PRESENT A POTENTIAL FOR FOG DEVELOPMENT IN
AREAS THAT GOT OR WILL GET A DOWNPOUR. THIS FOG SHOULD NOT BE WORTH
ANY TYPE OF ADVISORY AND OF THE KIND THAT DEPARTS BEFORE 9 AM. /BB/
&&
.PREV DISCUSSION... /ISSUED 319 PM CDT WED JUL 23 2014/
SHORT TERM...TONIGHT THROUGH FRIDAY NIGHT.
NOT AS MUCH CONVECTION POPPED UP TODAY AS ANTICIPATED DESPITE PWS
BEING NEAR 2 INCHES AND ABOVE 2000 J/KG CAPE CALCULATED FROM THIS
MORNING`S SOUNDING. SCATTERED CU COVER THE CWA CURRENTLY WITH JUST A
FEW RADAR ECHOES ACROSS THE AREA. WHATEVER IS LEFT AROUND SUNSET
TONIGHT WILL DIE QUICKLY.
WATCHING THE TROUGH AXIS/FRONT MOVE SOUTH/SOUTHEAST THROUGH ARKANSAS
AND OKLAHOMA THIS AFTERNOON. CONVECTION ASSOCIATED WITH THIS SHOULD
ALSO DIE OFF AFTER SUNSET TONIGHT. THE TROUGH AXIS WILL PUSH
SOUTHEAST THROUGH OUR CWA ON THURSDAY. ENOUGH LIFT ASSOCIATED WITH
THE BOUNDARY SHOULD IGNITE MORE STORMS TOMORROW AFTERNOON. THE FRONT
WILL STALL IN SOUTH AND SOUTHEAST MISSISSIPPI TOMORROW EVENING. WE
ARE NOT EXPECTING ANY SEVERE WEATHER WITH THIS ACTIVITY. STRONG
GUSTY WINDS WILL BE THE MAIN CONCERN. FRIDAY WILL BE RELATIVELY
QUIET WITH ONLY POPS IN THE SOUTHEAST CWA. STUCK WITH MOS GUIDANCE
FOR TEMPS OVER THE NEXT COUPLE DAYS. HOWEVER...HIGH TEMPS WERE
LOWERED JUST A TAD SINCE THE AREA HAS BEEN REALLY STRUGGLING TO
REACH TEMPS IN THE 90S. MOS LOW TEMPS LOOK GOOD. PATCHY FOG WILL BE
POSSIBLE AGAIN TOMORROW MORNING AND WILL QUICKLY DISSIPATE AFTER
13Z. /10/
LONG TERM...FRIDAY THROUGH NEXT WEDNESDAY...NORTH TO NORTHWEST
FLOW ALOFT LOOKS TO REMAIN OVER THE FORECAST AREA THROUGH MOST OF
THE FORECAST PERIOD AS HIGH PRESSURE ALOFT CENTERED NEAR THE FOUR
CORNERS REGION REMAINS WEDGED INTO THE SOUTHERN PLAINS STATES...
WHILE LONGWAVE TROUGHING ENCOMPASSES MUCH OF THE EASTERN HALF OF THE
UNITED STATES. THIS`LL ALLOW FOR A COUPLE OF RAIN-FREE DAYS AT A
TIME...FOLLOWED BY A DAY OR TWO OF INCREASED RAIN CHANCES AS ANOTHER
UPPER LEVEL DISTURBANCE TRIES TO PUSH A FRONT SOUTH INTO AND THROUGH
THE FORECAST AREA.
SOME SLIGHTLY DRIER AIR WILL ADVECT INTO THE REGION FRIDAY IN THE
WAKE OF THE FRONT NOW RESIDING SOUTH OF THE CWA. SATURDAY INTO
SUNDAY...MOISTURE WILL BEGIN TO SUBTLY RETURN TO THE CWA AS ANOTHER
FRONT APPROACHES FROM THE NORTH...WITH RAIN CHANCES INCREASING
SUNDAY NIGHT INTO MONDAY AS THE FRONT PUSH INTO AND THROUGH THE
FORECAST AREA. THIS THEN LOOKS TO BE FOLLOWED BY A COUPLE OF DAYS
OF QUITE WEATHER...TUESDAY AND WEDNESDAY...IN THE WAKE OF THE FRONT
WITH SOME MORE SLIGHTLY DRIER AIR FILTERING INTO THE REGION AT THAT
TIME.
AS FAR AS TEMPERATURES ARE CONCERNED...FOR THE MOST PART I STUCK
CLOSE TO GUIDANCE WITH LOWS THROUGH MUCH OF THE PERIOD. HOWEVER...
I DID ADJUST HIGHS DOWN A BIT HERE AND THERE EACH DAY...PARTICULARLY
ON SATURDAY AND SUNDAY. BOTH DAYS...I LOWERED HIGHS A FEW DEGREES
ACROSS THE BOARD AS I FELT UPPER 90S WERE TOO HIGH. MUCH OF THIS
STEMS FROM JUST THE PATTERN IN GENERAL WE`RE CURRENTLY OBSERVING AND
THE AFFECTS OF RECENT HEAVY RAINFALL OVER THE AREA KEEPING A HIGHER
MOISTURE CONTENT IN THE SOIL AND VEGETATION OVER THE AREA. AS A
RESULT... HIGHS FOR BOTH SATURDAY AND SUNDAY ARE NOW FORECAST TO BE
IN THE LOW TO MIDDLE 90S. /19/
&&
.AVIATION...ISOLATED HEAVY DOWNPOURS WILL HAVE POTENTIAL TO BRING
VERY LOCALIZED IFR CONDITIONS THROUGH MIDNIGHT. OTHERWISE...EXPECT
LIGHT AND VARIABLE WINDS WITH POTENTIAL FOR PATCHY MVFR TO IFR
CONDITIONS BY DAYBREAK THURSDAY...ESPECIALLY IN AREAS WHERE RAIN
FELL HEAVY LATE TODAY (SUCH AS GWO). TOMORROW WINDS WILL STILL BE
LIGHT BUT PRIMARILY FROM THE NORTHWEST AND NORTH WITH ISOLATED TO
SCATTERED SHOWERS AND THUNDERSTORMS AGAIN DEVELOPING IN THE MIDDAY
TO AFTERNOON HOURS. CONDITIONS AFTER TOMORROW MORNING SHOULD BE
PRIMARILY VFR AWAY FROM SAID THUNDERSTORMS. /BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 89 70 92 70 / 30 27 27 16
MERIDIAN 90 68 91 69 / 28 25 31 20
VICKSBURG 89 68 92 68 / 26 34 19 14
HATTIESBURG 89 69 92 72 / 22 14 31 21
NATCHEZ 88 69 91 70 / 27 28 21 16
GREENVILLE 92 70 91 66 / 23 31 15 8
GREENWOOD 89 68 89 64 / 29 33 23 9
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
BB/10/19
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1038 AM CDT TUE JUL 22 2014
.DISCUSSION...COLD CORE LOW WILL CONTINUE TO RETROGRADE INTO THE
ARKLAMISS FROM THE EAST THROUGH THE COURSE OF THE DAY. DEEPER
MOISTURE FILTERING IN FROM THE EAST COMBINED WITH DAYTIME HEATING
LOOKS TO YIELD CAPE VALUES AROUND 2000 J/KG THIS AFTERNOON WHICH IS
ADEQUATE TO SUPPORT A DECENT COVERAGE OF CONVECTION THROUGH THE
AFTERNOON HOURS...PARTICULARLY OVER AREAS ALONG AND EAST OF THE
NATCHEZ TRACE PARKWAY WERE AN AXIS OF BETTER LOW LEVEL MOISTURE
CONVERGENCE LOOKS TO EXIST. PRECIPITABLE H2O VALUES CLIMBING BACK
UP TO THE 1.75-2.00 INCH RANGE WILL SUPPORT THE POTENTIAL FOR SOME
LOCALIZED HEAVY RAINFALL.
MODEST MID-LEVEL FLOW ON THE ORDER OF 30-35 KNOTS AND ADVERTISED 30
KNOTS 0-6KM BULK SHEAR COULD AID IN SOME HEALTHY CORES THIS AFTERNOON
THAT`LL BE CAPABLE OF PRODUCING SOME GUSTY WINDS. THE LASTEST BATCH
OF HIGH-RES MODELS SEEM TO BE PICKING UP ON THIS TREND AS THEIR
CONVECTIVE OUTPUT IS A BIT MORE ROBUST THAN PREVIOUS RUNS. THIS
ACTIVITY IS EXPECTED TO GRADUALLY SUBSIDE IN BOTH INTENSITY AND
COVERAGE AS DAYTIME HEATING IS LOST THIS EVENING.
THE ONLY NOTABLE CHANGES TO THE FORECAST FOR TODAY...ASIDE FROM THE
TYPICAL HOURLY TRENDS...IS TO INCREASE POPS IN AREAS MAINLY ALONG
AND EAST OF THE NATCHEZ TRACE PARKWAY. OTHERWISE...REMAINING
ELEMENTS OF THE CURRENT FORECAST LOOK GOOD FOR TODAY. /19/
&&
.AVIATION...CONVECTION WILL INCREASE FROM THE EAST THIS AFTERNOOON...
BUT NO MORE THAN VICINITY EXPECTED AT TAF SITES. SOME MVFR CEILINGS
WILL BE POSSIBLE BETWEEN GTR AND MEI EARLY THIS AFTERNOON...OTHERWISE
VFR CONDITIONS WILL PREVAIL INTO THE EVENING AS CONVECTION WINDS
DOWN. THEREAFTER...MVFR CEILINGS IN THE EAST AND MVFR VISIBILITIES
EVERYWHERE WILL BE THE RULE UNTIL AROUND 14Z. /26/
&&
.PREV DISCUSSION... /ISSUED 529 AM CDT TUE JUL 22 2014/
SHORT TERM...THE PRIMARY WEATHER FEATURE AFFECTING THE ARKLAMISS
WILL BE A CLOSED COLD CORE LOW MIGRATING WESTWARD FROM AL INTO MS.
THERE IS A WEAK SURFACE REFLECTION THAT WILL AID IN LOW LEVEL
MOISTURE CONVERGENCE OVER EASTERN MS LATER THIS MORNING AND
AFTERNOON AS DEEPER MOISTURE SURGES WESTWARD TOWARD THE INTERSTATE
55 CORRIDOR AND COMBINES WITH DAYTIME HEATING. HRRR GUIDANCE
INDICATES CAPE VALUES PEAKING IN THE 2000-3000 J/KG RANGE AND
PRECIPITABLE WATER APPROACHING TWO INCHES - AND THIS WILL SUPPORT
THUNDERSTORM INITIATION ALONG THE LL MOISTURE CONVERGENCE AXIS
STRETCHING NORTH OF THE LOW CENTER. HIGH-RES MODEL OUTPUT VARIES IN
COVERAGE BUT THERE MAY BE SUFFICIENT EASTERLY MID LEVEL FLOW TO
SUPPORT MULTI-CELL STORM CLUSTERS ALONG ANY BOUNDARIES WITH STORMS
CAPABLE OF PRODUCING SOME STRONG WIND GUSTS. THE MOVEMENT OF STORMS
IN THIS FLOW PATTERN WOULD INCREASE RAINFALL COVERAGE AND HAVE
RAISED POPS SOME FOR TODAY.
EXPECT CONVECTIVE ACTIVITY TO WANE AFTER SUNSET THIS EVENING. THE
CLOSED LOW WILL CONTINUE ITS WESTWARD MIGRATION OVERNIGHT AND BETTER
MOISTURE CONVERGENCE SHOULD SET UP FARTHER WEST WEDNESDAY...AND HAVE
SHIFTED POPS SLIGHTLY IN THAT DIRECTION - A LITTLE MORE THAN MOS
GUIDANCE SUGGESTS. THE THERMODYNAMIC AND WIND PROFILES SHOULD BE
SIMILAR WEDNESDAY AND A FEW STRONG STORMS WOULD BE A POSSIBILITY
ONCE AGAIN. IT LOOKS LIKE NORTHERN STREAM SHORTWAVE ENERGY
APPROACHING THE AREA LATE WEDNESDAY NIGHT IS A LITTLE SLOWER IN THE
MODEL GUIDANCE...AND THE GREATER INFLUENCE ON ARKLAMISS WEATHER MAY
HOLD OFF UNTIL THURSDAY. HAVE RAISED POPS ABOVE GUIDANCE TO MAINTAIN
SOME CONTINUITY...ESPECIALLY WITH THE POSSIBILITY OF CONVECTIVE COLD
POOLS THAT COULD HELP TO SEND SHOWER/TSTM ACTIVITY A LITTLE FARTHER
SOUTH THAN EXPECTED INTO NRN PORTIONS OF THE AREA. /EC/
LONG TERM...THURSDAY TO TUESDAY. SO FAR...NO BIG PATTERN CHANGE FOR
THE REGION. WITH THE LARGE AREA OF HIGH PRESSURE PLANTED OVER THE
ROCKIES...THE ARKLAMISS WILL CONTINUE TO GET FRONTS AND WEAK
DISTURBANCES EVERY FEW DAYS. THE MOS CONTINUES TO BOUNCE AROUND WITH
THE TEMPERATURES. PERHAPS LEANING MORE TOWARD CLIMATOLOGY FOR THIS
TIME OF YEAR...THE TEMPS IN THE EXTENDED ARE BACK INTO THE UPPER
90S/MID 70S EARLY NEXT WEEK WHICH WOULD SUGGEST POSSIBLE INCREASE IN
HEAT STRESS. HOWEVER...WITH THE CURRENT PATTERN TEMPERATURES ARE
LIKELY TO BE AT OR BELOW NORMAL THROUGH THE EXTENDED. STUCK WITH
GUIDANCE GENERALLY FOR POPS AND TEMPS.
BY THURSDAY...IT LOOKS LIKE THE LATEST STALLED FRONT WILL BE
REPLACED WITH AN APPROACHING COLD FRONT. THIS BOUNDARY IS LIKELY TO
STALL ALONG THE COAST OVER THE WEEKEND...BEFORE THE NEXT FRONT MOVES
INTO THE REGION AROUND MONDAY. EACH SYSTEM SEEMS TO BE LACKING MUCH
UPPER LEVEL SUPPORT AND THE MAIN SURFACE LOW WITH EACH SYSTEM IS
ALSO DISTANT. HOWEVER...THE MODELS ARE BRINGING IN PLENTY OF VERY
MOIST AND UNSTABLE AIR FROM THE GULF. THERE IS A CHANCE OF RAIN
ACROSS THE AREA NEARLY EVERY DAY. WITH THE BEST DYNAMICS ASSOCIATED
WITH THE SYSTEMS STAYING TO THE NORTH AND THE WESTERN RIDGE WAVERING
FURTHER EAST SOME DAYS...MUCH OF THE THUNDERSTORM ACTIVITY WILL MISS
THE WESTERN ZONES...BASICALLY AREAS EAST OF INTERSTATE 55 THROUGH
THE PERIOD. OF COURSE THERE COULD BE SOME ISOLATED TO SCATTERED
THUNDERSTORMS...BUT POPS RIGHT NOW ARE LOW. BETWEEN EACH FRONT WILL
BE A DAY OR TWO OF MOSTLY CLEAR SKIES AND MILD CONDITIONS. NOT
ANTICIPATING A PATTERN SHIFT THIS FORECAST PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 90 71 91 71 / 46 32 34 22
MERIDIAN 88 69 91 69 / 60 39 28 23
VICKSBURG 90 70 92 71 / 20 20 34 22
HATTIESBURG 90 70 92 71 / 60 25 26 21
NATCHEZ 89 70 90 71 / 21 15 38 20
GREENVILLE 92 72 93 73 / 16 12 24 27
GREENWOOD 91 71 91 72 / 25 21 29 27
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
19/26
AREA FORECAST DISCUSSION
NWS JACKSON MS
529 AM CDT TUE JUL 22 2014
.SHORT TERM...THE PRIMARY WEATHER FEATURE AFFECTING THE ARKLAMISS
WILL BE A CLOSED COLD CORE LOW MIGRATING WESTWARD FROM AL INTO MS.
THERE IS A WEAK SURFACE REFLECTION THAT WILL AID IN LOW LEVEL
MOISTURE CONVERGENCE OVER EASTERN MS LATER THIS MORNING AND
AFTERNOON AS DEEPER MOISTURE SURGES WESTWARD TOWARD THE INTERSTATE
55 CORRIDOR AND COMBINES WITH DAYTIME HEATING. HRRR GUIDANCE
INDICATES CAPE VALUES PEAKING IN THE 2000-3000 J/KG RANGE AND
PRECIPITABLE WATER APPROACHING TWO INCHES - AND THIS WILL SUPPORT
THUNDERSTORM INITIATION ALONG THE LL MOISTURE CONVERGENCE AXIS
STRETCHING NORTH OF THE LOW CENTER. HIGH-RES MODEL OUTPUT VARIES IN
COVERAGE BUT THERE MAY BE SUFFICIENT EASTERLY MID LEVEL FLOW TO
SUPPORT MULTI-CELL STORM CLUSTERS ALONG ANY BOUNDARIES WITH STORMS
CAPABLE OF PRODUCING SOME STRONG WIND GUSTS. THE MOVEMENT OF STORMS
IN THIS FLOW PATTERN WOULD INCREASE RAINFALL COVERAGE AND HAVE
RAISED POPS SOME FOR TODAY.
EXPECT CONVECTIVE ACTIVITY TO WANE AFTER SUNSET THIS EVENING. THE
CLOSED LOW WILL CONTINUE ITS WESTWARD MIGRATION OVERNIGHT AND BETTER
MOISTURE CONVERGENCE SHOULD SET UP FARTHER WEST WEDNESDAY...AND HAVE
SHIFTED POPS SLIGHTLY IN THAT DIRECTION - A LITTLE MORE THAN MOS
GUIDANCE SUGGESTS. THE THERMODYNAMIC AND WIND PROFILES SHOULD BE
SIMILAR WEDNESDAY AND A FEW STRONG STORMS WOULD BE A POSSIBILITY
ONCE AGAIN. IT LOOKS LIKE NORTHERN STREAM SHORTWAVE ENERGY
APPROACHING THE AREA LATE WEDNESDAY NIGHT IS A LITTLE SLOWER IN THE
MODEL GUIDANCE...AND THE GREATER INFLUENCE ON ARKLAMISS WEATHER MAY
HOLD OFF UNTIL THURSDAY. HAVE RAISED POPS ABOVE GUIDANCE TO MAINTAIN
SOME CONTINUITY...ESPECIALLY WITH THE POSSIBILITY OF CONVECTIVE COLD
POOLS THAT COULD HELP TO SEND SHOWER/TSTM ACTIVITY A LITTLE FARTHER
SOUTH THAN EXPECTED INTO NRN PORTIONS OF THE AREA. /EC/
.LONG TERM...THURSDAY TO TUESDAY. SO FAR...NO BIG PATTERN CHANGE FOR
THE REGION. WITH THE LARGE AREA OF HIGH PRESSURE PLANTED OVER THE
ROCKIES...THE ARKLAMISS WILL CONTINUE TO GET FRONTS AND WEAK
DISTURBANCES EVERY FEW DAYS. THE MOS CONTINUES TO BOUNCE AROUND WITH
THE TEMPERATURES. PERHAPS LEANING MORE TOWARD CLIMATOLOGY FOR THIS
TIME OF YEAR...THE TEMPS IN THE EXTENDED ARE BACK INTO THE UPPER
90S/MID 70S EARLY NEXT WEEK WHICH WOULD SUGGEST POSSIBLE INCREASE IN
HEAT STRESS. HOWEVER...WITH THE CURRENT PATTERN TEMPERATURES ARE
LIKELY TO BE AT OR BELOW NORMAL THROUGH THE EXTENDED. STUCK WITH
GUIDANCE GENERALLY FOR POPS AND TEMPS.
BY THURSDAY...IT LOOKS LIKE THE LATEST STALLED FRONT WILL BE
REPLACED WITH AN APPROACHING COLD FRONT. THIS BOUNDARY IS LIKELY TO
STALL ALONG THE COAST OVER THE WEEKEND...BEFORE THE NEXT FRONT MOVES
INTO THE REGION AROUND MONDAY. EACH SYSTEM SEEMS TO BE LACKING MUCH
UPPER LEVEL SUPPORT AND THE MAIN SURFACE LOW WITH EACH SYSTEM IS
ALSO DISTANT. HOWEVER...THE MODELS ARE BRINGING IN PLENTY OF VERY
MOIST AND UNSTABLE AIR FROM THE GULF. THERE IS A CHANCE OF RAIN
ACROSS THE AREA NEARLY EVERY DAY. WITH THE BEST DYNAMICS ASSOCIATED
WITH THE SYSTEMS STAYING TO THE NORTH AND THE WESTERN RIDGE WAVERING
FURTHER EAST SOME DAYS...MUCH OF THE THUNDERSTORM ACTIVITY WILL MISS
THE WESTERN ZONES...BASICALLY AREAS EAST OF INTERSTATE 55 THROUGH
THE PERIOD. OF COURSE THERE COULD BE SOME ISOLATED TO SCATTERED
THUNDERSTORMS...BUT POPS RIGHT NOW ARE LOW. BETWEEN EACH FRONT WILL
BE A DAY OR TWO OF MOSTLY CLEAR SKIES AND MILD CONDITIONS. NOT
ANTICIPATING A PATTERN SHIFT THIS FORECAST PERIOD.
&&
.AVIATION...PATCHY AREAS OF FOG WILL MIX OUT QUICKLY AFTER SUNRISE
THIS MORNING AND VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
TONIGHT. INCREASINGLY MOIST AND UNSTABLE AIR WILL SUPPORT BETTER
AFTERNOON SHRA/TSRA COVERAGE...ESPECIALLY ALONG AND EAST OF THE
GWO/JAN/MCB CORRIDOR. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 90 71 91 71 / 34 32 34 22
MERIDIAN 89 69 91 69 / 52 39 28 23
VICKSBURG 90 70 92 71 / 20 20 34 22
HATTIESBURG 90 70 92 71 / 41 25 26 21
NATCHEZ 89 70 90 71 / 21 15 38 20
GREENVILLE 92 72 93 73 / 15 12 24 27
GREENWOOD 91 71 91 72 / 25 21 29 27
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
EC/07/
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
346 PM CDT Tue Jul 22 2014
.SHORT TERM: (Through Late Tonight)
Issued at 330 PM CDT Tue Jul 22 2014
There is a considerable amount of uncertainty in the convective
evolution and coverage tonight. Dew points in the 70s, strong
heating and steep mid level lapse rates are currently contributing
to SBCAPE of 3500-6000 j/kg across the northwest 2/3rds of the CWA
with the highest values across central and north central MO. There
also is a significant cap in place due to warm mid level temperatures.
The big question is when and how much of the cap will be reduced
as the front moves southward out of Iowa and southeast Nebraska
into northern MO this evening. Model solutions including the
convection allowing models are quite varied on QPF and implied
coverage. Recent runs of the HRRR are quite stingy on coverage
with isolated storms at best. I don`t have a great feel for what
is going to occur, but the deterministic models suggest that height
falls/cooling aloft should be sufficient to weaken the cap and
allow for scattered development along front, mainly late this
evening and especially overnight. I have attempted to follow this
trend with the greatest coverage along/east of the MS river. The
severe threat is conditional on development early enough this
evening to realize the big CAPE, and the main threat would appear
to be damaging winds given the warm air aloft.
Glass
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 330 PM CDT Tue Jul 22 2014
The cold front should lie roughly from south central IL to near
St. Louis into southwest MO at 12z and exit the CWA by early
afternoon. There will continue to be a threat of scattered showers
and storms ahead of the advancing front. Temperatures should be
cooler tomorrow with the main thrust of cooling and drying in the
afternoon. Unseasonably deep upper troffing in the eastern U.S.
will keep a large surface high dominating the area Wednesday night
into Friday, with most of this period dominated by lower humidity
and below average temperatures.
Beginning late Thursday night and into Friday the threat of precipitation
will return in association with elevated showers/thundestorms due to
strong warm advection/moisture transport via a southwesterly LLJ ahead
of the slowly retreating warm front and in association with impulses
aloft dropping southeastward along the eastern periphery of the
upper high. A cold front will then drop through the area Saturday
afternoon-Sunday as a upper trof digs southeastward from the upper
MS valley and into the Great Lakes bringing another threat of
showers and thunderstorms. This upper wave will be part of large
scale amplification of the upper air pattern across NOAM and will
feature another deep trof over the eastern U.S. through the first
part of next week and send out July with another period of below
average temperatures.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Wednesday Afternoon)
Issued at 131 PM CDT Tue Jul 22 2014
Upper level high retreating some to the west will allow fairly
strong short wave to drop into into the eastern US bringing
northwest flow back to the region. Associated surface cold front
will move through late tonight and Wednesday morning. Forecast
issue is when, where and if thunderstorms develop. Cooling aloft
has to occur before the instability disappears. No model is
convincing enough toexclusively follow. Have blended and followed
previous forecast putting storm at UIN about 00z and gradually
moving south, into STL at 06z. Models and soundings suggest some
mvfr cielings wednesday am.
Specifics for KSTL: Nothing out there has convinced me to change the
previous forecast. CWSU concurs to keep the prevailing
thunderstorms from 06 - 08z...with a couple of hours of mvfr
ceilings Wednesday am.
JPK
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
333 PM CDT Tue Jul 22 2014
.DISCUSSION...
Issued at 333 PM CDT TUE JUL 22 2014
Mid to upper 90s prevailing across much of the region this afternoon
as the warmest airmass of the season continues to grip the area.
Latest 850-mb analysis from the SPC meso site showing the 28C temp
contour directly over the fcst region this afternoon. This combined
with steep low-level lapse rates and dewpoints largely in the lower
to middle 70s has resulted in a very hot and oppressive day across
the area. Current heat advisory for the entire fcst area needs no
adjustments and is set to expire at 7 PM this evening.
In addition to the heat...the other main concern remains focused on
possible severe convection later this evening as main cold front now
found over southwestern IA and eastern NE continues to slowly track
south with time. For what its worth...high-res convection allowing
models struggled mightily with this mornings convection across
our northeastern zones...and very little guidance from these models
appears to be in the offering for activity later this evening as
well. Not surprisingly...overall confidence for tonight/s fcst is
less than desired as some models show developing convection...while
others such as the HRRR continue to backtrack towards a drier and
drier fcst with each successive run. So here/s what we know so far...
Sfc boundary set to arrive towards the IA/MO state line around 00z
this evening. Out ahead of this feature...airmass remains capped with
a significant amount of inhibition thanks that 700-mb temps ranging
in the 12-14C range. Additionally...northerly 925-850-mb winds will
provide little if any low-level convergence into the arriving
frontal boundary as we continue into the evening hrs. Despite
this...quick look at latest water vapor imagery does show an inbound
shortwave trough now seen over south-central NE and north-central
KS. This feature combined with very modest frontal convergence may be
enough to get this going...however concerns for widespread severe
remain marginal as of this writing. Latest SPC day 1 outlook has
trimmed the SLGT risk mention further to the southeast...which is
more in line with where convection may develop as front continues to
drop south. That said...main severe threat with any activity that
forms will likely be strong wind gusts as nearly dry adiabatic lapse
rates will support favorable low-level and boundary layer mixing.
High wet-bulb zero heights (>16 kft) will likely negate the threat
for very large hail until later on when any lingering activity begins
to go elevated with due to loss of daytime heating. Overall concerns
for hail though remain the lowest of the two forms of severe outlined
above however. In general...severe threat this evening looks to be
isolated with the most likely areas to possibly see a rogue storm or
two residing in our northeastern zones where better potential exists
to break the cap thanks to slightly cooler temps aloft. If activity gets
going...severe threat should transition south of the I-70 corridor as
front continues to make progress through the area. As mentioned above
through...a widespread severe event does not look to be in the
offering this evening.
Region should largely reside in a post frontal airmass
tomorrow...with weak dry air advection allowing for cooler and less
humid conditions. In fact...fcst models suggest dewpoints anywhere
between 5-10 degrees cooler than today...which should be a welcomed
relief following today/s oppressive conditions. High temps should
round out in the middle to upper 80s.
Large scale pattern shift expected from Thursday into Friday as southern
Plains ridge retrograde west as northern stream energy traverses the
northern Rockies/Plains. As this occurs...upper flow will become
decidedly more northwesterly which will set the stage for unsettled
conditions heading into the upcoming weekend. Closer to the
surface...fcst models still paint a northward retreating warm front
by late week as return flow reestablishes itself across the Great
Plains in advance of leeside troughing along the Front Range. Several
upper shortwaves embedded in northwest flow will allow for continued
chances for showers and storms through at least Saturday...if not
Sunday. As is the case with convection this time of year...hard to
pin your hat on any one feature of interest as long range models to
include both the ECMWF and GFS normally suffer from convective
feedback issues to some degree. As a result...have maintained Chc
pops through the weekend before high pressure arrives by early next
week following the passage of a cold front on Sunday. Temps early
next week look to fall below normal with highs possibly only reaching
into the lower to middle 80s come Monday and Tuesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday Afternoon)
Issued at 1244 PM CDT TUE JUL 22 2014
Main concern heading into the fcst period remains focused on
convection as weak cold front sinks south across the area. Latest
model trends show the best potential east of all terminal sites but
given the amount of uncertainty with the fcst...VCTS mention was
maintained for all locations after 00z this evening. After 6z...any
convection that does form should be south with weak northeast flow
expected through the remainder of the overnight. Some potential for
developing VSBY restrictions at STJ after 09z as front fails to scour
out abundant low-level moisture.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...HEAT ADVISORY until 7 PM CDT this evening FOR KSZ025-057-060-
102>105.
MO...HEAT ADVISORY until 7 PM CDT this evening FOR MOZ001>008-011>017-
020>025-028>033-037>040-043>046-053-054.
&&
$$
DISCUSSION...32
AVIATION...32
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CDT Mon Jul 21 2014
.UPDATE:
Issued at 920 PM CDT Mon Jul 21 2014
The going forecast remains on track this evening, with only minor
changes to account for near-term trends. The HRRR has continued to
indicate some showers developing over northeastern MO and west
central IL around daybreak, but recent runs have gotten more
conservative. Therefore, have maintained the dry forecast given
low confidence.
JP
&&
.SHORT TERM: (Tonight through Tuesday)
Issued at 322 PM CDT Mon Jul 21 2014
The forecast is evolving pretty much as expected today and the
trends anticipated through tomorrow still look on track. Temperatures
tonight will be milder than last night with a gradual increase in
some mid/high clouds from the northwest late tonight. Still
wondering if we might see a few high based showers with this mid
level moisture and steep lapse rates near and just after dawn
across north central/northeast Missouri, but at this point my
confidence is not high enough to add pops and later shifts will
need to keep a close eye. Otherwise the hotest day of the week is
still on tap for Tuesday with a strong low-level thermal ridge
focused across the northern half of the CWA with H85 temps above
+22 degC, favoring widespread highs in the 90s. The northwest
1/3-1/2 of the CWA should have peak heat index values above 100
degrees. If the dew points top the mid 70s across northeast
Missouri, then some locations might see heat indices hit advisory
criteria of 105+. At this point my forecast is just below that
value. Warm mid level temperatures of +12 to +14 degC should
sufficiently cap surface based convection.
Glass
.LONG TERM: (Tuesday Night through Next Monday)
Issued at 322 PM CDT Mon Jul 21 2014
A short wave will dig across the upper-mid MS valley and into the
Great Lakes Tuesday night into Wednesday, and this will send a
formidable cold front across the region. The air mass ahead of the
front will be moist and unstable and height falls/cooling aloft
associated with the upper wave should be sufficient for scattered
thunderstorms/multicell clusters with the progressing front. The
front and precipitation threat should be south of the CWA by early
Wednesday evening. Deepening of the eastern trof and and an expansive
surface high in the wake of the cold front will bring another nice
couple of days with below average temperatures for Thursday/Friday.
However by late Friday and especially Friday night into Saturday
we will be looking at increasing precipitation chances again -
first in association with several northwest flow disturbances and
the retreating front, and then with another cold front passage.
Glass
&&
.AVIATION: (For the 06z TAFs through 06z Tuesday Night)
Issued at 1144 PM CDT Mon Jul 21 2014
VFR with sly to swly winds aob 10kts is expected thru Tues
afternoon. SUS may see some FG a couple of hours before sunrise
Tues morning, however, confidence in this event is decreasing due
to greater dewpoint spread and ssely flow. There is some
indication that TSRA may form during the pre-dawn hours Tues
morning across the srn half of IA. If these TSRA do form, believe
they will remain N of UIN, but this remains uncertain. A cdfnt is
expected to approach the region Tues evening. This fnt may bring
isod to sct TSRA along and just ahead of the fnt with winds
becoming nly behind the fnt. Due to less and somewhat uncertain
coverage of TSRA, have only added VCTS for now.
Specifics for KSTL: VFR and dry thru the TAF period with sly to
swly winds ahead of an approaching cdfnt. This fnt is expected to
push thru the terminal late Tues night. This fnt may be
accompanied by TSRA. However, there is too much uncertainty
regarding coverage and occurrence and have kept out of TAF for now.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1024 AM MDT TUE JUL 22 2014
.UPDATE...
THE MAIN UPDATE TO THE FORECAST THIS MORNING WAS TO SLOW DOWN THE
PROGRESSION OF THE SHORTWAVE ACROSS THE FORECAST AREA...TO HOLD
POPS IN ACROSS CENTRAL ZONES INTO THIS EVENING. THE BEST THREAT OF
SEVERE WEATHER REMAINS OVER FAR SOUTHEAST MONTANA...BASICALLY FROM
MILES CITY TO BROADUS AND EAST. LATEST HIGH RESOLUTION MODELS WANT
TO KEEP THE MAIN SEVERE THREAT SOUTH INTO NORTH EAST WYOMING AND
WESTERN SOUTH DAKOTA...BUT WANT TO CLIP OUR AREA WITH SOME STORMS.
FORECAST THINKING IS THAT THESE MODELS ARE DISPLACING THE
CONVECTION TOO FAR SOUTH THIS AFTERNOON...AND THAT THE GOING
FORECAST REMAINS ON TRACK. FOR LOCATIONS FARTHER WEST...MODELS
HAVE TRENDED SLOWER ON THE TIMING OF THE WEAK SHORTWAVE...AND THUS
GIVE A BETTER CHANCE FOR AN ISOLATED STRONG STORM SOMEWHERE AROUND BILLINGS
TO ROUNDUP AROUND 00Z TO 02Z AND TRACKING EASTWARD FROM THERE.
THUS HAVE KEPT AN ISOLATED POP FOR CENTRAL ZONES THROUGH
03Z...TRENDING DOWN THEREAFTER.
CHURCH
&&
.SHORT TERM...VALID FOR TDY AND WED...
WEAK SHORTWAVE ENERGY CONTINUES TO LIFT THRU A RELATIVELY MOIST
AND UNSTABLE WSW FLOW ALOFT...AND PER LATEST RAP H5 ANALYSIS OUR
HEIGHTS HAVE NOT YET BEGUN TO RISE. AT 2 AM THERE EXISTS A FEW
LIGHT SHOWERS IN OUR CWA BUT THERE IS MORE UPSTREAM FROM SOUTH
CENTRAL MT TO NORTHERN NV. HEIGHT RISES WILL COMMENCE LATER TODAY
BUT IN THE MEANTIME AREAS OF PV INTERACTING WITH PWATS ON THE
ORDER OF AN INCH SHOULD BE ENOUGH FOR ISOLD SHOWERS/TSTMS ACROSS
MUCH OF THE AREA TODAY...AND CANNOT DISCOUNT SOME AFTN DEVELOPMENT
AS MID LEVEL CAP WILL BE SLOW TO DEVELOP. FEEL THAT BY LATE AFTN
OR EARLY EVENING THE PV WILL HAVE LIFTED NORTH AND MOST SHOWER
ACTIVITY WILL END. TEMPS TODAY WILL BE CLOSE TO NORMAL WITH HIGHS
IN THE MID 80S TO LOWER 90S.
MOST IMPORTANT ISSUE TO ADDRESS TODAY EXISTS IN OUR EAST. SLOWER
ONSET OF HEIGHT RISES WILL RESULT IN A SLIGHT RISK OF SEVERE
STORMS FROM MILES CITY TO BROADUS EAST. ASCENT WILL COME IN THE
FORM OF WEAK SHORTWAVE ENERGY ALONG A MID LEVEL WARM FRONT...AND
A LOW LEVEL JET BY EVENING...WITH 1000+ J/KG OF CAPE AND 0-6KM
BULK SHEAR ON THE ORDER OF 50 KTS. HAIL AND TO A LESSER DEGREE
WIND WILL BE THE PRIMARY THREATS. LOW LEVEL SOUTHEASTERLY FLOW
WILL KEEP THE HIGH PWAT AIR IN PLACE...SO HEAVY RAIN IS ALSO A
POSSIBILITY. WILL HIGHLIGHT THE RISK FOR SEVERE WEATHER FOR THIS
AFTN AND EARLY EVENING IN OUR EAST IN THE HWO/GRAPHIC.
RIDGE WILL STRENGTHEN CONSIDERABLY TONIGHT AND WEDNESDAY WITH
HEIGHTS EXPECTED TO CLIMB INTO THE 590S...CORRESPONDING WITH 700MB
TEMPS TO NEAR +16C. THIS TONGUE OF VERY WARM MID LEVEL AIR AND
LACK OF SIGNIFICANT FORCING WILL LIMIT OUR CONVECTIVE POTENTIAL
CONSIDERABLY. INSTABILITY AND SHEAR PROFILES WILL BE IMPRESSIVE
CLOSE TO THE DAKOTAS BORDER ON WEDNESDAY WITH STRONG SELY SFC
FLOW DEVELOPING...SO IF A STORM IS ABLE TO DEVELOP IT WILL HAVE A
VERY FAVORABLE ENVIRONMENT TO WORK WITH. WILL KEEP WITH ISOLD
TSTMS MENTIONED IN OUR EAST. OUR CENTRAL AND WEST PARTS WILL BE
MUCH DRIER WITH DEEPER MIXING. HAVE REMOVED MENTION OF TSTMS FOR
MOST OF THIS AREA BUT KEPT ISOLD POPS IN OUR NW...CLOSER TO COOLER
MID LEVEL TEMPS AND SHORTWAVE ENERGY IN WESTERN MT. COULD SEE SOME
RIDGE RUNNER CONVECTION ACROSS NORTHERN MT WEDNESDAY NIGHT...BUT
FEEL THIS WILL STAY NORTH OF OUR CWA.
AS FOR TEMPERATURES...WEDNESDAY SHOULD BE THE WARMEST DAY YET OF
2014 FOR MOST OF OUR CWA. GIVEN THE 700MB TEMPS EXPECTED WE SHOULD
SEE SOME AREAS REACH THE 100 DEGREE MARK...PERHAPS BILLINGS. HAVE
RAISED TEMPS A FEW DEGREES BOTH WEDNESDAY AND WEDNESDAY NIGHT.
THE RECORD HIGH OF 101F MAY BE APPROACHED AT LIVINGSTON...
ESPECIALLY IF SW WINDS MIX OUT. RECORDS AT BILLINGS...MILES CITY
AND SHERIDAN APPEAR TOO HIGH TO BE REACHED ON WEDNESDAY.
OF COURSE...THE HOT WEATHER WILL CONTINUE TO WORK ON OUR DRYING
FUELS...SETTING THE STAGE FOR A POTENTIALLY CRITICAL FIRE WEATHER
DAY BY THURSDAY.
JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THURSDAY STILL SHAPING UP FOR A POSSIBLE CRITICAL FIRE WEATHER DAY
AS A DEEP TROUGH AND ASSOCIATED CLOSED LOW ALOFT CRASH THROUGH THE
HIGH PRESSURE RIDGE THAT WILL BE OVER THE AREA. MODELS CONSISTENCY
REMAINS VERY GOOD WITH CONFIDENCE CONTINUING TO INCREASE WITH THIS
SYSTEM. 850 MB TEMPERATURES ARE EXPECTED TO RANGE FROM +28C TO 30C
ACROSS THE FORECAST AREA. STRONG COMPRESSIONAL HEATING WILL TAKE
PLACE AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH DURING THE LATE
AFTERNOON HOURS. GFS SOUNDINGS CONTINUE TO INDICATE MIXING UP TO
NEAR 500 MB. THIS WILL CAUSE TEMPERATURES OVER THE CENTRAL AND
EASTERN ZONES TO CLIMB TO NEAR 100 DEGREES AT A FEW LOCATIONS.
GUSTY WINDS DEVELOPING WITH THE FRONTAL PASSAGE AND THIS COMBINED
WITH HUMIDITIES IN THE TEENS...WILL CREATE DANGEROUS FIRE WEATHER
CONDITIONS. ZONAL FLOW SETTING UP FRIDAY FOR DRY AND COOLER
WEATHER. DRY WEATHER AND NEAR TO SLIGHTLY ABOVE SEASONAL
TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS ANOTHER
RIDGE OF HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS. RICHMOND
&&
.AVIATION...
ISOLATED TO WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED OVER THE
AREA TODAY AND THIS EVENING...MAINLY BETWEEN 21 AND 03 UTC. SOME
RISK OF MVFR OR LOCAL/BRIEF IFR CONDITIONS EXISTS WITH ANY STORM
THAT DOES DEVELOP...AND THERE IS A THREAT OF SEVERE THUNDERSTORM
ACTIVITY WITH LARGE HAIL AND DAMAGING WINDS...MAINLY OVER SOUTH-
EASTERN MT. SCHULTZ
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 090 063/098 066/098 057/085 057/085 058/087 059/090
2/T 21/U 11/N 11/U 11/U 11/U 11/U
LVM 090 055/099 056/091 049/083 049/083 049/088 051/090
2/T 21/B 11/N 10/U 01/U 11/U 11/U
HDN 092 059/100 062/101 057/086 056/086 057/088 058/091
2/T 21/U 11/G 11/U 11/U 11/U 11/U
MLS 090 065/098 067/097 059/085 058/085 059/086 059/088
3/T 32/T 21/U 11/U 11/N 11/U 11/U
4BQ 090 061/098 064/100 058/085 058/085 058/085 058/088
3/T 32/T 21/U 11/U 11/U 11/U 11/U
BHK 086 060/091 062/096 057/083 053/083 054/083 054/084
4/T 32/T 22/T 21/U 11/N 11/U 11/U
SHR 090 057/098 059/098 053/084 053/084 053/085 054/087
2/T 21/U 11/U 11/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
234 AM MDT TUE JUL 22 2014
.SHORT TERM...VALID FOR TDY AND WED...
WEAK SHORTWAVE ENERGY CONTINUES TO LIFT THRU A RELATIVELY MOIST
AND UNSTABLE WSW FLOW ALOFT...AND PER LATEST RAP H5 ANALYSIS OUR
HEIGHTS HAVE NOT YET BEGUN TO RISE. AT 2 AM THERE EXISTS A FEW
LIGHT SHOWERS IN OUR CWA BUT THERE IS MORE UPSTREAM FROM SOUTH
CENTRAL MT TO NORTHERN NV. HEIGHT RISES WILL COMMENCE LATER TODAY
BUT IN THE MEANTIME AREAS OF PV INTERACTING WITH PWATS ON THE
ORDER OF AN INCH SHOULD BE ENOUGH FOR ISOLD SHOWERS/TSTMS ACROSS
MUCH OF THE AREA TODAY...AND CANNOT DISCOUNT SOME AFTN DEVELOPMENT
AS MID LEVEL CAP WILL BE SLOW TO DEVELOP. FEEL THAT BY LATE AFTN
OR EARLY EVENING THE PV WILL HAVE LIFTED NORTH AND MOST SHOWER
ACTIVITY WILL END. TEMPS TODAY WILL BE CLOSE TO NORMAL WITH HIGHS
IN THE MID 80S TO LOWER 90S.
MOST IMPORTANT ISSUE TO ADDRESS TODAY EXISTS IN OUR EAST. SLOWER
ONSET OF HEIGHT RISES WILL RESULT IN A SLIGHT RISK OF SEVERE
STORMS FROM MILES CITY TO BROADUS EAST. ASCENT WILL COME IN THE
FORM OF WEAK SHORTWAVE ENERGY ALONG A MID LEVEL WARM FRONT...AND
A LOW LEVEL JET BY EVENING...WITH 1000+ J/KG OF CAPE AND 0-6KM
BULK SHEAR ON THE ORDER OF 50 KTS. HAIL AND TO A LESSER DEGREE
WIND WILL BE THE PRIMARY THREATS. LOW LEVEL SOUTHEASTERLY FLOW
WILL KEEP THE HIGH PWAT AIR IN PLACE...SO HEAVY RAIN IS ALSO A
POSSIBILITY. WILL HIGHLIGHT THE RISK FOR SEVERE WEATHER FOR THIS
AFTN AND EARLY EVENING IN OUR EAST IN THE HWO/GRAPHIC.
RIDGE WILL STRENGTHEN TONIGHT AND WEDNESDAY WITH HEIGHTS EXPECTED
TO CLIMB INTO THE 590S...CORRESPONDING WITH 700MB TEMPS TO NEAR
+16C. THIS TONGUE OF VERY WARM MID LEVEL AIR AND LACK OF
SIGNIFICANT FORCING WILL LIMIT OUR CONVECTIVE POTENTIAL
CONSIDERABLY. INSTABILITY AND SHEAR PROFILES WILL BE IMPRESSIVE
CLOSE TO THE DAKOTAS BORDER ON WEDNESDAY WITH STRONG SELY SFC FLOW
DEVELOPING...SO IF A STORM IS ABLE TO DEVELOP IT WILL HAVE A VERY
FAVORABLE ENVIRONMENT TO WORK WITH. WILL KEEP WITH ISOLD TSTMS
MENTIONED IN OUR EAST. OUR CENTRAL AND WEST PARTS WILL BE MUCH
DRIER WITH DEEPER MIXING. HAVE REMOVED MENTION OF TSTMS FOR MOST
OF THIS AREA BUT KEPT ISOLD POPS IN OUR NW...CLOSER TO COOLER MID
LEVEL TEMPS AND SHORTWAVE ENERGY IN WESTERN MT. COULD SEE SOME
RIDGE RUNNER CONVECTION ACROSS NORTHERN MT WEDNESDAY NIGHT...BUT
FEEL THIS WILL STAY NORTH OF OUR CWA.
AS FOR TEMPERATURES...WEDNESDAY SHOULD BE THE WARMEST DAY YET OF
2014 FOR MOST OF OUR CWA. GIVEN THE 700MB TEMPS EXPECTED WE SHOULD
SEE SOME AREAS REACH THE 100 DEGREE MARK...PERHAPS BILLINGS. HAVE
RAISED TEMPS A FEW DEGREES BOTH WEDNESDAY AND WEDNESDAY NIGHT.
THE RECORD HIGH OF 101F MAY BE APPROACHED AT LIVINGSTON...
ESPECIALLY IF SW WINDS MIX OUT. RECORDS AT BILLINGS...MILES CITY
AND SHERIDAN APPEAR TOO HIGH TO BE REACHED ON WEDNESDAY.
OF COURSE...THE HOT WEATHER WILL CONTINUE TO WORK ON OUR DRYING
FUELS...SETTING THE STAGE FOR A POTENTIALLY CRITICAL FIRE WEATHER
DAY BY THURSDAY.
JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
THURSDAY STILL SHAPING UP FOR A POSSIBLE CRITICAL FIRE WEATHER DAY
AS A DEEP TROUGH AND ASSOCIATED CLOSED LOW ALOFT CRASH THROUGH THE
HIGH PRESSURE RIDGE THAT WILL BE OVER THE AREA. MODELS CONSISTENCY
REMAINS VERY GOOD WITH CONFIDENCE CONTINUING TO INCREASE WITH THIS
SYSTEM. 850 MB TEMPERATURES ARE EXPECTED TO RANGE FROM +28C TO 30C
ACROSS THE FORECAST AREA. STRONG COMPRESSIONAL HEATING WILL TAKE
PLACE AHEAD OF A COLD FRONT THAT WILL MOVE THROUGH DURING THE LATE
AFTERNOON HOURS. GFS SOUNDINGS CONTINUE TO INDICATE MIXING UP TO
NEAR 500 MB. THIS WILL CAUSE TEMPERATURES OVER THE CENTRAL AND
EASTERN ZONES TO CLIMB TO NEAR 100 DEGREES AT A FEW LOCATIONS.
GUSTY WINDS DEVELOPING WITH THE FRONTAL PASSAGE AND THIS COMBINED
WITH HUMIDITIES IN THE TEENS...WILL CREATE DANGEROUS FIRE WEATHER
CONDITIONS. ZONAL FLOW SETTING UP FRIDAY FOR DRY AND COOLER
WEATHER. DRY WEATHER AND NEAR TO SLIGHTLY ABOVE SEASONAL
TEMPERATURES WILL CONTINUE THROUGH EARLY NEXT WEEK AS ANOTHER
RIDGE OF HIGH PRESSURE BUILDS OVER THE NORTHERN PLAINS. RICHMOND
&&
.AVIATION...
ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP OVER THE AREA
TODAY. MVFR CONDITIONS CAN BE EXPECTED IN OR NEAR ANY STORMS.
THERE IS A THREAT OF SEVERE THUNDERSTORMS EAST OF A LINE FROM
MILES CITY TO BROADUS THIS AFTERNOON AND EVENING. LARGE HAIL
AND STRONG WINDS WILL BE THE PRIMARY THREAT WITH THESE STORMS.
RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 090 063/098 066/098 057/085 057/085 058/087 059/090
2/T 11/U 11/N 11/U 11/U 11/U 11/U
LVM 090 055/099 056/091 049/083 049/083 049/088 051/090
2/T 21/B 11/N 10/U 01/U 11/U 11/U
HDN 092 059/100 062/101 057/086 056/086 057/088 058/091
2/T 11/U 11/G 11/U 11/U 11/U 11/U
MLS 090 065/098 067/097 059/085 058/085 059/086 059/088
3/T 22/T 21/U 11/U 11/N 11/U 11/U
4BQ 090 061/098 064/100 058/085 058/085 058/085 058/088
3/T 22/T 21/U 11/U 11/U 11/U 11/U
BHK 086 060/091 062/096 057/083 053/083 054/083 054/084
4/T 32/T 22/T 21/U 11/N 11/U 11/U
SHR 090 057/098 059/098 053/084 053/084 053/085 054/087
2/T 11/U 11/U 11/U 11/U 11/U 11/U
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...NONE.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1241 PM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CDT TUE JUL 22 2014
IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24
HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY
LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE
CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED
STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME
STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS
AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH
BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE
STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE
COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW
ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY
NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT
CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A
FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE
TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON
WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD
CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST
1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY.
STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE
IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE
LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE
ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL
PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST
APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF
FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER
PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM
MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING
EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE
NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A
VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN
MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN
VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER
WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE
AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN
THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST
COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING
EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS
EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE
MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO
WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME
DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES
OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER
60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM
MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER
60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT
GRADIENT.
HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A
TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL
FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH
MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO
THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE
DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE
COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH
PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE
SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH
CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO
AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR
THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE
STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE
AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK
LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM
MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO
FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE
MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED
SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG
THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO
KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY
THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE
NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE
AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE
LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN
THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT
MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN
ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER
CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS
ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR
EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST
08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT
ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS
EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT
ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL
NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER
UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1
OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW
WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM
THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS
HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS
ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH
TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS
BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT
HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW
90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES.
WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW
DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER.
THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF
A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO
REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY
FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER-
THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT
MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA
TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT
LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE
95-102 RANGE.
FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES
WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH
IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL
REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER
LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH
PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY
ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA
AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM
THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST-
NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH
PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL
AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE
CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY
EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN
CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF
THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF).
MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM
WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF
CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER
MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING
SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB
AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET
CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE
CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE
LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST
SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN
ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY
RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST
INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS
AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 501 AM CDT TUE JUL 22 2014
TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH
THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD
OR SIGNIFICANT AT THIS POINT IN TIME.
FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS
WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES
ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU
THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS
IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE
LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN
ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM
BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY
LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES.
HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT
CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF
THE FRONTAL BOUNDARY IN OUR SOUTH.
TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE
UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING
EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE
END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND
HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING
MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING
THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD
FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST
DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH
THE BOUNDARY.
OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND
BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT
LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE
MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL
READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE
OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU.
THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR
CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR
SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1232 PM CDT TUE JUL 22 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS SHOULD BE
EAST TO NORTHEAST.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR NEZ064-074>077-
083>087.
KS...HEAT ADVISORY UNTIL 8 PM CDT THIS EVENING FOR KSZ005>007-017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
653 AM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CDT TUE JUL 22 2014
IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24
HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY
LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE
CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED
STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME
STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS
AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH
BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE
STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE
COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW
ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY
NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT
CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A
FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE
TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON
WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD
CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST
1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY.
STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE
IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE
LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE
ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL
PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST
APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF
FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER
PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM
MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING
EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE
NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A
VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN
MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN
VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER
WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE
AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN
THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST
COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING
EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS
EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE
MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO
WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME
DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES
OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER
60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM
MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER
60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT
GRADIENT.
HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A
TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL
FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH
MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO
THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE
DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE
COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH
PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE
SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH
CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO
AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR
THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE
STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE
AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK
LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM
MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO
FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE
MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED
SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG
THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO
KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY
THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE
NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE
AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE
LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN
THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT
MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN
ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER
CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS
ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR
EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST
08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT
ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS
EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT
ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL
NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER
UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1
OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW
WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM
THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS
HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS
ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH
TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS
BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT
HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW
90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES.
WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW
DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER.
THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF
A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO
REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY
FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER-
THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT
MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA
TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT
LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE
95-102 RANGE.
FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES
WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH
IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL
REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER
LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH
PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY
ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA
AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM
THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST-
NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH
PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL
AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE
CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY
EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN
CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF
THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF).
MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM
WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF
CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER
MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING
SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB
AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET
CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE
CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE
LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST
SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN
ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY
RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST
INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS
AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 501 AM CDT TUE JUL 22 2014
TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH
THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD
OR SIGNIFICANT AT THIS POINT IN TIME.
FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS
WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES
ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU
THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS
IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE
LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN
ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM
BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY
LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES.
HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT
CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF
THE FRONTAL BOUNDARY IN OUR SOUTH.
TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE
UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING
EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE
END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND
HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING
MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING
THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD
FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST
DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH
THE BOUNDARY.
OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND
BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT
LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE
MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL
READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE
OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU.
THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR
CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR
SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z WEDNESDAY)
ISSUED AT 653 AM CDT TUE JUL 22 2014
CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY PERSISTING
THROUGH THE PERIOD UNDER FAIRLY LIMITED COVERAGE OF MID-HIGH
CLOUDS. ALTHOUGH NOT ZERO...THE CHANCES OF ANY
SHOWERS/THUNDERSTORMS AFFECTING THE TERMINALS SEEMS TO BE NO
HIGHER THAN 10-20 PERCENT...AND THUS CANNOT EVEN JUSTIFY A
VICINITY THUNDERSTORM (VCTS) MENTION AT THIS TIME. IF ANY STORMS
WERE HAPPEN TO BECOME AN ISSUE...IT WOULD LIKELY BE LATE TONIGHT
DURING THE LATTER 6 HOURS OF THE PERIOD. SUSTAINED SURFACE BREEZES
ARE EXPECTED TO AVERAGE AT/UNDER 12KT THROUGH THE MAJORITY OF THE
PERIOD...ALTHOUGH SOME BRIEF PERIODS OF ENHANCED GUSTINESS UP TO
AROUND 20KT CANNOT BE RULED OUT MAINLY THIS MORNING. ALTHOUGH A
WEST-NORTHWEST WIND DIRECTION MAY HOLD ON FOR A FEW HOURS
INITIALLY THIS MORNING...A PASSING COLD FRONT SHOULD SOON RESULT
IN PREVAILING NORTHEAST BREEZES THAT ARE EXPECTED TO PERSIST
THROUGH THE REMAINDER OF THE PERIOD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR NEZ064-074>077-083>087.
KS...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR KSZ005>007-017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS HASTINGS NE
502 AM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM CDT TUE JUL 22 2014
IN SHORT...THERE ARE TWO MAIN CONCERNS THROUGH THE NEXT 24
HOURS...ONE BEING ANOTHER DAY OF AT LEAST MARGINALLY-ADVISORY
LEVEL HEAT INDEX VALUES ACROSS ROUGHLY THE SOUTHEAST 1/2 OF THE
CWA...AND THE OTHER BEING WHETHER OR NOT A FEW ISOLATED
STORM/POSSIBLY A BROKEN LINE OF STORMS CAN FLARE UP AND BECOME
STRONG TO SEVERE GENERALLY NEAR/SOUTH OF THE STATE LINE LATE THIS
AFTERNOON INTO THIS EVENING ALONG A SURFACE COLD FRONT. BOTH
BEFORE AND AFTER THIS MAIN TIME FRAME OF CONCERN FOR POSSIBLE
STRONG CONVECTION...AT LEAST ISOLATED CONVECTION CANNOT BE
COMPLETELY RULED OUT. STARTING WITH THIS MORNING...SUPPOSE A FEW
ROGUE SHOWERS/POSSIBLY A WEAK ELEVATED STORM SLIPPING INTO MAINLY
NORTHERN PORTIONS OF THE CWA IS NOT OUT OF THE QUESTION...BUT
CONFIDENCE IN THIS OCCURRING IS NOT HIGH ENOUGH TO INTRODUCE A
FORMAL MENTION INTO A PREVIOUSLY-DRY FORECAST. THEN LATE
TONIGHT...GENERALLY AFTER MIDNIGHT...CONFIDENCE IS VERY LOW ON
WHAT WILL TRANSPIRE...AS SOME MODELS SHOW POTENTIALLY WIDESPREAD
CONVECTION DEVELOPING OVER OR MOVING INTO PRIMARILY THE SOUTHWEST
1/2 OF THE CWA...WHILE OTHERS ARE BONE DRY.
STARTING WITH THE HERE AND NOW AS OF 09Z/4 AM...DRY CONDITIONS ARE
IN PLACE OVER THE CWA...WHILE AT LEAST A FEW COUNTIES OUTSIDE THE
LOCAL AREA A SMATTERING OF WEAK ELEVATED THUNDERSTORMS ARE
ROAMING PARTS OF WESTERN/NORTH CENTRAL NEB AND ALSO A SMALL
PORTION OF WEST CENTRAL IA. THE ACTIVITY TO THE NORTH AND WEST
APPEARS TO BE TIED MAINLY TO AN EAST-WEST ORIENTED ZONE OF
FRONTOGENESIS IN THE 850-700MB LAYER. IN THE BIGGER
PICTURE...WATER VAPOR SATELLITE IMAGERY ALONG WITH SHORT TERM
MODEL DATA HIGHLIGHT THE EXPANSIVE HIGH/ANTICYCLONE EXTENDING
EASTWARD INTO THE CENTRAL PLAINS FROM ITS CENTRAL CORE OVER THE
NM/CO BORDER AREA. IN THE STRONGER FLOW TO THE THE NORTH...A
VIGOROUS SHORTWAVE TROUGH WAS TRACKING EASTWARD ACROSS NORTHERN
MN. ESSENTIALLY...THE LOCAL AREA LIES ALONG THE INTERFACE BETWEEN
VERY WEAK MID/UPPER FLOW TO THE SOUTH AND SOMEWHAT STRONGER
WESTERLY FLOW JUST TO THE NORTH ALONG THE FRINGES OF THE RIDGE
AXIS. AT THE SURFACE...HIGH PRESSURE CENTERED OFF TO THE NORTH IN
THE WAKE OF THE NORTHERN MN SHORTWAVE TROUGH HAS PUSHED A MODEST
COLD FRONT SOUTHWARD INTO NEBRASKA OVERNIGHT...WITH ITS LEADING
EDGE ALREADY WORKING INTO NORTHERN PORTIONS OF THE CWA AS
EVIDENCED BY A SHIFT TO SOME NORTHERLY WIND COMPONENT...WHILE THE
MAJORITY OF THE CWA HAS OBSERVED SOME VARIATION OF SOUTHERLY TO
WESTERLY BREEZES IN THE 5-15 MPH RANGE OVERNIGHT. ALTHOUGH SOME
DRIER LOW- 60S DEWPOINTS HAVE ADVECTED INTO WESTERN ZONES
OVERNIGHT...MUCH OF THE EASTERN CWA CONTINUES HOLDING ONTO UPPER
60S-LOW 70S DEWPOINTS...MAKING FOR ANOTHER SEASONABLY WARM
MORNING. LOW TEMPS WILL LIKELY EXHIBIT A RANGE FROM UPPER
60S/NEAR-70 WEST TO UPPER 70S-NEAR 80 EAST GIVEN THIS DEWPOINT
GRADIENT.
HEADING INTO THE DAYTIME HOURS...THE BIG PICTURE ALOFT INVOLVES A
TRANSITION FROM MORE WESTERLY TO MORE NORTHERLY MID-UPPER LEVEL
FLOW...IN RESPONSE TO THE EXPANSIVE RIDGE EDGING SLIGHTLY NORTH
MORE OVER CO...AND THE NORTHEAST EDGE OF THIS RIDGE AXIS CLOSER TO
THE LOCAL AREA BEING FLATTENED SOMEWHAT IN THE WAKE OF THE
DEPARTING GREAT LAKES AREA TROUGH. MEANWHILE AT THE SURFACE...THE
COLD FRONT WILL CONTINUE SINKING SOUTHWARD ACROSS THE AREA AS HIGH
PRESSURE SHIFTS EASTWARD ACROSS THE DAKOTAS/MN AREA. ALTHOUGH THE
SOUTHWARD PUSH OF THIS FRONT SHOULD EASE WITH TIME...MOST OF SOUTH
CENTRAL NEBRASKA SHOULD OBSERVE PREVAILING NORTHEAST BREEZES UP TO
AROUND 10-15 MPH THROUGH MOST OF THE DAY...WHILE LOCATIONS NEAR
THE STALLING SOUTHERN EDGE OF THIS BOUNDARY NEAR AND SOUTH OF THE
STATE LINE WILL OBSERVE A LIGHT/VARIABLE TO LIGHT SOUTHERLY BREEZE
AS THE FRONT IS REINFORCED NEAR THE STATE LINE IN RESPONSE TO WEAK
LOW PRESSURE CENTERED NEAR THE CO/KS BORDER. ALTHOUGH VERY WARM
MID LEVEL TEMPS ON THE ORDER OF 13-15C AT 700MB SHOULD CONTINUE TO
FIRMLY CAP LOW-LEVEL BASED CONVECTION THROUGH AT LEAST THE
MAJORITY OF THE DAY...THERE ARE HINTS THAT A FEW ELEVATED
SPRINKLES OR EVEN WEAK STORMS COULD PERCOLATE ABOVE THE CAP ALONG
THE ELEVATED FRONTAL ZONE MAINLY THIS MORNING...AND WILL HAVE TO
KEEP AN EYE OUT IN CASE SOME LOW POPS MIGHT NEED ADDED TO MAINLY
THE NORTHERN CWA. OTHERWISE...THE MAIN FOCUS FOR POTENTIALLY MORE
NOTEWORTHY AND LOWER-BASED CONVECTION SHOULD HOLD OFF UNTIL LATE
AFTERNOON/EARLY EVENING NEARER THE SURFACE FRONT NEAR THE STATE
LINE. ALTHOUGH THIS DEVELOPMENT IS CERTAINLY NO GUARANTEE GIVEN
THE STRONG CAP...THE HOT/DEEPLY MIXED AIRMASS SOUTH OF THE FRONT
MAY BE ENOUGH TO TRIGGER AT LEAST ISOLATED CONVECTION IN AN
ENVIRONMENT CHARACTERIZED BY AROUND 2000-3000 J/KG MIXED LAYER
CAPE BUT ONLY AROUND 25KT AT MOST OF DEEP LAYER SHEAR. SOME MODELS
ARE MORE AGGRESSIVE WITH OTHERS IN THIS STORM DEVELOPMENT...AS FOR
EXAMPLE THE 00Z 4KM NSSL WRF STRONGLY SUGGESTS IT WHILE THE LATEST
08Z RAP KEEPS STORMS AT BY LOCALLY THROUGH AT LEAST 02Z/9PM. AT
ANY RATE...MAINTAINED THE SLIGHT POPS FOR LATE THIS AFTERNOON/THIS
EVENING TO COVER AT LEAST THE POSSIBILITY OF THIS DEVELOPMENT
ALONG THE EAST-WEST FRONTAL ZONE. DESPITE THE VERY CONDITIONAL
NATURE OF THIS STORM DEVELOPMENT...THE STORM PREDICTION CENTER
UPGRADED MUCH OF THE SOUTHERN CWA TO A SLIGHT RISK ON THE DAY 1
OUTLOOK...WITH THE MAIN THREATS LIKELY BEING STRONG OUTFLOW
WINDS/DOWNBURST ACTIVITY...AND LESS-SO LARGE HAIL GIVEN SUCH WARM
THERMAL PROFILES. SPEAKING OF THERMAL...TEMPERATURES AND DEWPOINTS
HAVE BEEN A BIT OF A CHALLENGE FOR TODAY...AS MUCH OF THIS DEPENDS
ON HOW FAST THE SLIGHTLY COOLER AIR CAN FILTER IN FROM THE NORTH
TODAY...AND WHETHER DEWPOINTS AGAIN SPIKE BACK UP BEHIND THIS
BOUNDARY AFTER FALLING OFF SOMEWHAT OVERNIGHT. TOOK A BEST STAB AT
HIGHS USING A BLEND OF VARIOUS MODELS...YIELDING A RANGE FROM LOW
90S FAR NORTH...MID 90S CENTRAL AND GENERALLY 100-102 IN KS ZONES.
WOULD NOT BE SURPRISED THOUGH TO SEE PARTS OF THE NORTH STAY A FEW
DEGREES COOLER AND PARTS OF THE SOUTH RISE A FEW DEGREES HIGHER.
THE NET RESULT FOR HEAT INDEX VALUES IS THAT AREAS MAINLY SOUTH OF
A YORK-MINDEN LINE (INCLUDING KS) APPEAR MOST FAVORED TO
REACH/SLIGHTLY EXCEED 105...AND THUS HAVE GONE WITH AN ADVISORY
FOR THESE LOCATIONS ALTHOUGH DO NOT EXPECT AS MUCH OF THE HIGHER-
THAN-EXPECTED COVERAGE OF 110+ HEAT INDEX READINGS THAT
MATERIALIZED YESTERDAY IN EASTERN ZONES. OUTSIDE THE ADVISORY AREA
TO THE NORTH AND WEST...IT WILL OBVIOUSLY STILL BE HOT...BUT
LOOKING FOR SUB-ADVISORY LEVEL HEAT INDEX VALUES MORE INTO THE
95-102 RANGE.
FOR THIS EVENING/TONIGHT...OBVIOUSLY HEAT INDEX/ADVISORY ISSUES
WILL QUICKLY ABATE...LEAVING THE ULTIMATE QUESTION AS TO HOW MUCH
IF ANY CONVECTION AND POSSIBLE STRONG-SEVERE STORM POTENTIAL
REMAINS THROUGH THE NIGHT. AS FOR THE BIG PICTURE OF THE MID-UPPER
LEVELS...FLOW WILL TURN EVEN MORE NORTHERLY AS THE STRONG HIGH
PRESSURE CENTER PARKS ITSELF FIRMLY OVER CENTRAL CO...WHICH ACTUALLY
ALLOWS MID LEVEL TEMPS TO COOL VERY SLIGHTLY OVER THE LOCAL AREA
AS A LOW-AMPLITUDE SHORTWAVE TROUGH BRUSHES BY ALONG A TRACK FROM
THE DAKOTAS INTO IA OVERNIGHT. AT THE SURFACE...GENERALLY EAST-
NORTHEAST BREEZES AROUND 10 MPH WILL PREVAIL OVERNIGHT AS HIGH
PRESSURE REMAINS CENTERED WELL OFF TO THE NORTHEAST OF THE LOCAL
AREA. AS MENTIONED ABOVE...THERE IS TREMENDOUS UNCERTAINTY IN THE
CONVECTIVE POTENTIAL OVERNIGHT. ONE SCENARIO IS THAT ONCE ANY
EVENING ACTIVITY DIES OUT OR MOVES OUT OF THE AREA IN THE SOUTHERN
CWA ALONG THE FRONTAL ZONE THAT NOTHING ELSE OCCURS THE REST OF
THE NIGHT (PER THE ECMWF AND ALSO THE NSSL 4KM-WRF).
MEANWHILE...OTHER MODELS SUCH AS THE NAM/GFS AND ALSO THE 4KM
WRF-NMM SIMULATED REFLECTIVITY SHOW POTENTIALLY A FAIR AMOUNT OF
CONVECTION AFFECTING MAINLY THE SOUTHWEST HALF OF THE CWA AFTER
MIDNIGHT...POSSIBLY AS A RESULT OF A STORM COMPLEX RIDING
SOUTHEASTWARD INTO THE AREA OUT OF THE BLACK HILLS/NORTHWEST NEB
AREA. GIVEN THE TREMENDOUS UNCERTAINTY HERE...OPTED NOT TO GET
CUTE WITH THE FORECAST AND JUST BLANKETED MUCH OF THE
CENTRAL/SOUTHERN CWA WITH A GENERIC SLIGHT 20 PERCENT POP FOR THE
LATER NIGHT HOURS. BESIDES CONVECTIVE POTENTIAL...SUPPOSE AT LEAST
SOME LIGHT FOG CANNOT BE RULED OUT LATE TONIGHT MAINLY IN WESTERN
ZONES...BUT CURRENT MODELS/GUIDANCE DO NOT SUPPORT VISIBILITY
RESTRICTIONS BAD ENOUGH/WIDESPREAD ENOUGH FOR A FORMAL FORECAST
INCLUSION AT THIS TIME. AS FOR LOW TEMPS...ONLY MADE MINOR TWEAKS
AIMING FOR A RANGE FROM MID 60S NORTH TO AROUND 70 SOUTH.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 501 AM CDT TUE JUL 22 2014
TEMPS WILL BE UP AND DOWN DURING THE EXTENDED PERIODS AND ALTHOUGH
THERE ARE HIT OR MISS CHCS FOR TSTMS...NOTHING IS LOOKING WIDESPREAD
OR SIGNIFICANT AT THIS POINT IN TIME.
FOLLOWING THE REALLY HOT TEMPERATURES MONDAY AND TUESDAY...READINGS
WILL TREND COOLER ON WEDNESDAY AS THE UPPER RIDGE AXIS RETROGRADES
ALONG THE HIGH PLAINS AND A TROUGH DEEPENS FM THE GREAT LAKES THRU
THE OHIO VALLEY REGION. THE HOT AIR RETREATS AND COOLER AIR BACKS
IN FROM THE EAST AND H85 TEMPS COOL SEVERAL DEGREES AND WE ARE
LOOKING FOR AFTERNOON HIGHS TO RANGE FROM THE MID 80S IN OUR EASTERN
ZONES TO AROUND 90F IN THE SW. A 1020MB SFC HIGH PRESSURE SYSTEM
BUILDS SOUTH FROM THE UPPER MIDWEST WHICH WILL RESULT IN EASTERLY
LLVL FLOW AND BRING THE COOLEST CONDITIONS TO OUR EASTERN ZONES.
HAVE KEPT THE FORECAST DRY BUT THERE IS AN OUTSIDE CHC FOR REMNANT
CONVECTION TO LINGER FOR A TIME WEDNESDAY MORNING IN THE VCNTY OF
THE FRONTAL BOUNDARY IN OUR SOUTH.
TEMPERATURES WILL BE ON THE INCREASE AGAIN THURSDAY FRIDAY AS THE
UPPER RIDGE AXIS BUILDS EAST AGAIN AHEAD OF AN UPPER LOW TRANSLATING
EAST FROM THE PACIFIC NORTHWEST. THE RIDGE AXIS DEAMPLIFIES BY THE
END OF THE WEEK BUT THE AIRMASS REMAINS QUITE WARM THRU FRIDAY AND
HIGH TEMPERATURES SHOULD AGAIN AVERAGE IN THE 90S. A PROGRESSING
MID LEVEL SHORTWAVE TROUGH AND WAA AHEAD OF THE SYSTEM WILL BRING
THE POTENTIAL FOR TSTMS THURSDAY AND THURSDAY NIGHT. THEN...A COLD
FRONT ASSOCIATED WITH THE NORTHERN CONUS SYSTEM PUSHES SOUTHEAST
DURING THE DAY ON FRIDAY BUT CHCS FOR STORMS LOOK NEGLIGIBLE WITH
THE BOUNDARY.
OVER THE WEEKEND AND EARLY NEXT WEEK THE UPPER RIDGE RETROGRADES AND
BUILDS OVER THE ROCKIES WHILE AN UPPER TROUGH DEEPENS FM THE GREAT
LAKES THROUGH THE OHIO VALLEY. COOLER AIR WILL RETURN IN THE MORE
MERIDIONAL FLOW AND TEMPERATURES WILL DROP BACK CLOSER TO SEASONAL
READINGS OR BELOW. CANNOT COMPLETELY RULE OUT PCPN CHCS IN THE
OUTER PERIODS AS TEMPERATURES COOL ALOFT AND BOUNDARIES MOVE THRU.
THIS BEING SAID NOTHING SAID THERE IS NO REAL CONCLUSIVE PERIOD FOR
CONVECTION EITHER AND HAVE ONLY CARRIED LOW POPS IN OUR SOUTH FOR
SUNDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z TUESDAY)
ISSUED AT 1252 AM CDT TUE JUL 22 2014
CONFIDENCE IS FAIRLY HIGH IN VFR CEILING/VISIBILITY PERSISTING
THROUGH THE PERIOD UNDER VARIABLE COVERAGE OF HIGH CLOUDS...AND
WITH THE CHANCE OF ANY SHOWERS/THUNDERSTORMS IN THE AREA LIKELY
AVERAGING ONLY AROUND 10 PERCENT (MAINLY FOR THE TUESDAY EVENING
HOURS)...CANNOT EVEN JUSTIFY A VICINITY THUNDERSTORM (VCTS)
MENTION AT THIS TIME. ALTHOUGH THERE COULD BE SOME MARGINAL LOW
LEVEL WIND SHEAR RIGHT AWAY DURING THE FIRST FEW HOURS THIS
MORNING...THE OVERALL BULK SHEAR DIFFERENCE WITHIN THE LOWEST 2000
FT APPEARS TO ONLY TOP OUT AROUND 25-30KT AT BEST...AND SLOWLY
DECREASING WITH TIME. AS A RESULT...HAVE REFRAINED FROM ANY FORMAL
LLWS MENTION IN THE TAFS. SUSTAINED SURFACE BREEZES ARE EXPECTED
TO AVERAGE AT/UNDER 12KT THROUGH THE MAJORITY OF THE PERIOD...WITH
THE MAIN FEATURE BEING A WIND SHIFT ASSOCIATED WITH A WEAK COLD
FRONT THAT WILL SWITCH DIRECTION FROM SOUTH-SOUTHWESTERLY EARLY
THIS MORNING TO PREVAILING NORTHEASTERLY FROM MID-LATE MORNING
ONWARD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR NEZ064-074>077-083>087.
KS...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS EVENING
FOR KSZ005>007-017>019.
&&
$$
SHORT TERM...PFANNKUCH
LONG TERM...FAY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
437 AM EDT TUE JUL 22 2014
.SYNOPSIS...
A FRONTAL BOUNDARY WILL LIFT NORTH ACROSS THE AREA AND DISSIPATE
TODAY. A STRONGER FRONT WILL APPROACH FROM THE WEST THURSDAY AND
MOVE INTO THE AREA FRIDAY...BECOMING STATIONARY SATURDAY...THEN
LIFTING BACK NORTH AS A WARM FRONT SUNDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM TUESDAY...EASTERN NC REMAINS BETWEEN UPPER RIDGING
OVER THE WESTERN ATLANTIC AND A CUT-OFF LOW OVER THE GULF STATES
WHICH CONTINUES TO BRING A MOISTURE RICH AIRMASS ACROSS THE AREA
TODAY...AS IS EVIDENT IN WV IMAGERY AND 00Z KMHX SOUNDING SHOWING
PWATS UP TO 2.25". AT THE SURFACE...A STATIONARY FRONT IS
POSITIONED JUST OFF THE COAST...WHICH WILL LIFT NORTH ACROSS THE
AREA TODAY AND DISSIPATE. CONVERGENCE ALONG THE BOUNDARY...ALONG
WITH LINGERING OUTFLOW BOUNDARIES...WILL PROVIDE THE FOCUS FOR
CONVECTIVE DEVELOPMENT THROUGH THE DAY. AS SUCH...EXPECT GREATEST
COVERAGE OF SHOWERS ALONG COASTAL AREAS THIS MORNING...THEN
TRANSITION INLAND AS THE BOUNDARY LIFTS NORTH. THE AIRMASS REMAINS
MODESTLY UNSTABLE WITH MUCAPES AROUND 1000-2000 J/KG AND 0-6KM
BULK SHEAR REMAINS WEAK...AROUND 15 KT OR LESS...SIMILAR TO
YESTERDAY WITH A VERY LOW THREAT FOR SEVERE STORMS. HOWEVER...
BUFKIT SOUNDINGS SHOW MBE VELOCITY WEAK THIS MORNING...LESS THAN
10 KT...SUGGESTING HEAVY PRECIP AND POSSIBLE TRAINING OF CELLS
RESULTING IN LOCALLY HEAVY RAINFALL WHICH COULD PRODUCE LOCALIZED
FLOODING OF POOR DRAINAGE OR LOW LYING AREAS. MBE VELOCITY
INCREASES TO 15-18 KT THIS AFTERNOON ALLOWING THE THREAT TO
DIMINISH SOMEWHAT. ABUNDANT CLOUDS AND PRECIP WILL HOLD TEMPS TO
THE LOW TO MID 80S AGAIN TODAY.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM TUESDAY...A SHORTWAVE TROUGH AND ATTENDANT COLD FRONT
MOVE ACROSS THE GREAT LAKES/MID WEST TONIGHT BRINGING SLIGHT
HEIGHT FALLS ALOFT...WHILE THE BERMUDA HIGH STRENGTHENS OFF THE
SOUTHEAST COAST ALLOWING WINDS BECOME S/SW. EXPECT
SHOWERS/THUNDERSTORMS TO DIMINISH FAIRLY QUICKLY INLAND THIS
EVENING WITH LOSS OF DAYTIME HEATING WITH ACTIVITY SHIFTING TO THE
COASTAL WATERS AS IS A TYPICAL NOCTURNAL TREND IN THIS PATTERN.
PATCHY/AREAS OF FOG OR STRATUS WILL BE POSSIBLE AGAIN TONIGHT.
LOWS EXPECTED IN THE LOW TO MID 70S.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
DEEP MSTR WILL CONTINUE TO STREAM OVER AREA BETWEEN UPR RIDGE AND
UPR LOW RETROGRADING ACROSS GULF COAST. SFC PATTERN WILL RETURN TO
MORE TYPICAL BERMUDA HIGH/INLAND TROF. SCT CONVECTIVE ACTIVITY PSBL
ANY TIME...THUS CONTINUED 20-40 POPS...WITH MORE COVERAGE EXPECTED
WED AFTN ACRS INLAND SECTIONS.
RIDGE BREAK DOWNS WED NIGHT AND THU WITH APPROACH OF SHORT WV TROF
AND SFC FRONT FROM THE NW. HIGHER POPS EXPECTED ON THE COAST WED
NIGHT WITH PSBL CONVECTION MOVING IN OFF WATER. KEPT 40-60 POPS FOR
THU AFTN WITH HIGHEST POPS INLAND ASSOC WITH THE SHT
WV...APPROACHING FRONT AND SEA BREEZE FRONT MOVING INLAND. GOOD CHC
POPS ALL AREAS THU NIGHT AND FRIDAY WITH FRONT AND SHT WV TROF
MOVING INTO AREA.
MODELS INDICATE SFC FRONT STALLS JUST S OF AREA SAT MORNING WITH
SCT CONVECTION PSBL ACRS SRN SECTIONS WITH SEA BREEZE INTERACTION.
FRONT LIFTS BACK N ON SUNDAY BUT KEPT LOW 20/30 POPS DURING THE
LATER PART OF THE EXTDD FCST WITH NEAR NORMAL TEMPS.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 2 AM TUESDAY...AREAS OF FOG AND STRATUS ACROSS RTES THIS
MORNING...MAINLY ALONG AND SOUTH OF HWY 70 BRINGING IFR/LIFR
CONDITIONS...AFFECTING MOST TAF SITES EXCEPT PGV. PGV MAY SEE
PERIODS OF SUB VFR CONDITIONS THIS MORNING BUT HRRR MODEL
SUGGESTING STRATUS WILL MAINLY BE CONFINED SOUTH OF HWY 70.
STRATUS WILL LIFT AROUND 12-13Z WITH SCATTERED TO NUMEROUS SHOWERS
AND TSTMS EXPECTED ACROSS RTES AGAIN TODAY WITH A MOIST AND
UNSTABLE AIRMASS IN PLACE AND A WEAK BOUNDARY LIFTING ACROSS THE
AREA. WEAK SHEAR SHOULD PREVENT THE SEVERITY OF STORMS BUT THEY
WILL HAVE THE POTENTIAL TO PRODUCE LOCALLY HEAVY RAINFALL. SHOWERS
DIMINISH THIS EVENING WITH LOSS DAYTIME HEATING AND AREAS OF FOG
OR STRATUS WILL BE POSSIBLE AGAIN TONIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 300 AM TUESDAY...SCATTERED MAINLY DIURNAL CONVECTION POSSIBLE
AT TAF SITES THROUGH PERIOD WITH BEST COVERAGE EXPECTED THU AFTN
THROUGH FRIDAY AS A COLD FRONT MOVES INTO THE AREA. LATE NIGHT/EARLY
AM FOG POSSIBLE ESPECIALLY IN AREAS THAT RECEIVED RAIN THE PREVIOUS
DAY.
&&
.MARINE...
SHORT TERM/THROUGH TONIGHT/
AS OF 4 AM TUESDAY...A FRONTAL BOUNDARY IS STALLED ACROSS THE
SOUTHERN/CENTRAL WATERS THIS MORNING AND IS EXPECTED TO LIFT NORTH
ACROSS THE AREA TODAY ALLOWING E/SE WINDS AROUND 15 KT OR LESS TO
GRADUALLY SHIFT TO SLY FROM SOUTH TO NORTH THROUGH THE DAY INTO
THE EARLY EVENING HOURS...THEN BECOME SWLY AROUND 10-15 KT OVERNIGHT
AS THE BERMUDA HIGH STRENGTHENS OFFSHORE. WAVEWATCH AND LOCAL
SWAN/NWPS IN GOOD AGREEMENT WITH SEAS CONTINUING AROUND 2-4 FT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/
AS OF 300 AM TUESDAY...SW WINDS 10 TO 15 KT AND SEAS 2-4 FT ON WED
THEN PRESSURE GRADIENT TIGHTENS UP AHEAD OF AN APPROACHING COLD
FRONT. PSBL SMALL CRAFT CONDS FOR SEAS THURSDAY INTO FRIDAY FOR
PORTIONS OF THE COASTAL WATERS SOUTH OF OREGON INLET AS SW WINDS
INCR TO 15-20 KT AND SEAS BUILD TO 4 TO 6 FT. WINDS SHIFT TO NLY AND
SEAS DIMINISH BEHIND A COLD FRONT FRI NIGHT INTO SAT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...JAC
AVIATION...JAC/SK
MARINE...JAC/SK
AREA FORECAST DISCUSSION
NWS BISMARCK ND
933 PM CDT WED JUL 23 2014
.UPDATE...
ISSUED AT 925 PM CDT WED JUL 23 2014
WHILE CONVECTION HAS REMAINED LOW IN COVERAGE THROUGH 230 UTC
ACROSS CENTRAL AND EASTERN MONTANA INTO SOUTHWEST
SASKATCHEWAN...IT HAS INCREASED IN INTENSITY OVER THE PAST HOUR.
SPC HAS JUST ISSUED A SEVERE THUNDERSTORM WATCH ACROSS NORTH
CENTRAL MONTANA. SEE SPC MCD 1452 FOR DETAILS REGARDING TRENDS
THROUGH 345 UTC AS STORMS PROPAGATE EAST. ALL MODEL GUIDANCE HAS
HAD A TOUGH TIME HANDLING THE CONVECTIVE SCENARIO THIS
EVENING...WITH STORMS NOW EXPECTED TO APPROACH THE NORTH DAKOTA
BORDER AROUND 07-09 UTC.
UPDATE ISSUED AT 539 PM CDT WED JUL 23 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. STILL MONITORING
FOR CONVECTIVE INITIATION ACROSS CENTRAL INTO EASTERN MONTANA OVER
THE NEXT ONE TO TWO HOURS. THE 20 UTC HRRR WOULD SUGGEST
MONTANA SURFACE BASED CONVECTION APPROACHING THE NORTH DAKOTA BORDER
BY 03-04 UTC...CONTINUING TO PROPAGATE INTO CENTRAL NORTH DAKOTA
BY 08-09 UTC SUSTAINED BY A 30-35 KT LOW LEVEL JET. THE BEST
CHANCE FOR LARGE HAIL AND DAMAGING WINDS ARE GENERALLY ALONG AND
WEST OF HIGHWAY 85 AS THE MONTANA CONVECTION PROPAGATES INTO
WESTERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
FORECAST ISSUES IN THE SHORT TERM ARE THUNDERSTORM CHANCES...AND
POSSIBILITY OF SEVERE STORMS.
CURRENTLY...SURFACE HIGH WAS OVER MANITOBA SOUTHWARD THROUGH THE RED
RIVER VALLEY...WITH LOW PRESSURE IN THE LEE OF THE ROCKIES.
SOUTHEASTERLY FLOW WAS KEEPING MOIST LOW LEVELS WITH DEWPOINTS IN
THE 60S OVER WESTERN AND CENTRAL NORTH DAKOTA. AT UPPER LEVELS...A
SHARP RIDGE WAS IN PLACE FROM SASKATCHEWAN TO THE WESTERN DAKOTAS
AND EASTERN MT/WY. BEST SHEAR AND MID LEVEL LAPSE RATES WERE OVER
THE FRONT RANGE THIS AFTERNOON...WITH MOST UNSTABLE CAPES OVER THE
FRONT RANGE INTO THE WESTERN DAKOTAS.
LATEST MODEL RUNS SUGGEST THUNDERSTORMS DEVELOPING OVER CENTRAL AND
EASTERN MONTANA THIS EVENING IN THE VICINITY OF A MID LEVEL
SHORTWAVE ENERGY IMPULSE FORECAST TO MOVE/DEVELOP INTO NORTHEASTERN
MONTANA DURING THE EVENING. ONCE CONVECTION BECOMES BETTER
ESTABLISHED...THE SCENARIO IS FOR STORMS TO MIGRATE EASTWARD INTO
WESTERN NORTH DAKOTA LATER THIS EVENING...THEN SPREAD INTO CENTRAL
NORTH DAKOTA AFTER MIDNIGHT. THE WESTERN THIRD OF NORTH DAKOTA HAS
THE BEST POTENTIAL FOR SEVERE STORMS LATE THIS EVENING INTO THE
EARLY MORNING HOURS.
ONGOING CONVECTION DAYBREAK THURSDAY OVER MUCH OF CENTRAL NORTH
DAKOTA EXPECTED TO CONTINUE MOVING EASTWARD. THEN...ATTENTION TURNS
TO THE WEST AS A SIGNIFICANT UPPER LOW EMERGES INTO THE FRONT RANGE
FROM THE ROCKIES WITH STRONG SOUTHWEST FLOW ALOFT INTO THE DAKOTAS.
AT THE SAME TIME...THE AFOREMENTIONED SURFACE LOW OVER THE FRONT
RANGE WILL HAVE MOVED/DEVELOPED EASTWARD INTO THE WESTERN DAKOTAS.
THESE INGREDIENTS WILL BE FAVORABLE FOR PLENTY OF SHEAR...CAPE
(ESPECIALLY WITH SURFACE DEWPOINTS IN THE 65 TO 70 DEGREE
RANGE)...AND UPPER LEVEL IMPULSES. GOOD CHANCE OF THUNDERSTORMS
THURSDAY AFTERNOON OVER THE WESTERN THIRD OF THE STATE. THIS WILL
CONTINUE INTO THE EVENING HOURS AS WELL...WITH SEVERE WEATHER
POSSIBLE OVER MUCH OF THE FORECAST AREA THURSDAY AFTERNOON/NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
THE MAIN FEATURES IN THE LONG TERM PERIOD CONTINUE TO BE AN UPPER
LOW OFF THE WA/OR COAST AND ITS INTERACTION WITH THE DOWNSTREAM
H500 RIDGE OVER THE NORTHERN PLAINS. AS THE UPPER LOW MOVES EAST
AND FLATTENS THE RIDGE...A COLD FRONT AT THE SURFACE WILL
POSITION ITSELF ACROSS EASTERN MONTANA BY THURSDAY AFTERNOON. THE
FRONT WILL THEN PUSH EAST ACROSS NORTH DAKOTA THURSDAY
EVENING AND OVERNIGHT INTO FRIDAY MORNING. THUNDERSTORMS...A FEW
POSSIBLY SEVERE WITH STRONG WINDS AND HAIL THE MAIN THREATS WILL
ACCOMPANY THE FRONT AS IT PROGRESSES EAST THROUGH THE STATE
THURSDAY AFTERNOON AND EVENING. ON FRIDAY COOLER BUT STILL
REASONABLY MILD TEMPERATURES IN THE UPPER 70S TO LOWER 80S SHOULD
BE THE RULE. ANY SHOWERS AND ISOLATED THUNDERSTORMS SHOULD BE
LIMITED TO THE EAST. ONE MORE DAY OF SHOWERS/SCATTERED
THUNDERSTORMS ON SATURDAY AS THE SLOW MOVING UPPER LOW TRACKS
SOUTH ACROSS MINNESOTA. WHILE THE STATE WILL GENERALLY BE ON THE
DRY SIDE OF THE UPPER LOW CANT RULE OUT SHOWERS AS COOL AIR ALOFT
SHOULD SUPPORT SOME INSTABILITY...ESPECIALLY NORTH. AS THE UPPER
LOW DRIFTS EAST AND A RIDGE POPS UP IN MONTANA SUNDAY THROUGH
TUESDAY...SHOULD BE DRY WITH GENERALLY PLEASANT TEMPERATURES AND
HUMIDITY FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 933 PM CDT WED JUL 23 2014
VFR CONDITIONS OUTSIDE OF THUNDERSTORMS ARE FORECAST FOR THE 00
UTC TAF CYCLE ACROSS WESTERN AND CENTRAL NORTH DAKOTA.
THUNDERSTORMS ARE FORECAST TO ENTER WESTERN NORTH DAKOTA AROUND
03-04 UTC...AND MOVE INTO CENTRAL NORTH DAKOTA BY 08-09 UTC. SEE
TAFS FOR TIMING AND THREAT DETAILS. ANOTHER ROUND OF THUNDERSTORMS
IS EXPECTED LATE THURSDAY AFTERNOON AND INTO THE EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1131 PM CDT MON JUL 21 2014
.UPDATE...
ISSUED AT 1123 PM CDT MON JUL 21 2014
HIGH WIND WARNING CRITERIA NON-THUNDERSTORM WINDS HAVE DEVELOPED
ON THE BACKSIDE OF A DEPARTING COMPACT INTENSE SURFACE LOW
PRESSURE CENTERED JUST SW OF FSE. AS THE LOW PROPAGATES EASTWARD
EXPECT THESE STRONGER WINDS TO SPREAD INTO PARTS OF NW MN EARLY
THIS AM. AS A RESULT HAVE ISSUED A HIGH WIND WARNING FOR THE NEXT
SEVERAL HOURS. OTHERWISE SEVERE THREAT HAS NEARLY EXITED THE
FORECAST AREA TO THE EAST. ADJUSTED POPS AND CONFINED SEVERE
MENTION TO OUR EASTERN FA BORDER AREA FOR THE NEXT HOUR OR SO.
UPDATE ISSUED AT 949 PM CDT MON JUL 21 2014
ADJUSTED POPS TO CURRENT RADAR IMAGERY AND TRIMMED EASTERN ND OUT
OF WATCH.
UPDATE ISSUED AT 640 PM CDT MON JUL 21 2014
ADJUSTED EARLY EVENING POPS HIGHLIGHTING MAIN CONVECTION OVER THE
FAR NW FA. MAIN THREAT WILL BE WIND AND HEAVY RAIN. EXPECT
CONVECTION TO GRADUALLY EXPAND AS MAIN COMPLEX MOVES IN FROM THE
WEST WITH HEAVY RAIN/DAMAGING WINDS MAIN THREAT. NO OTHER
CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 315 PM CDT MON JUL 21 2014
CONVECTION TIMING AND SEVERITY WILL BE THE MAIN FORECAST HEADACHE
FOR THE SHORT TERM.
STORMS HAVE DEVELOPED OVER WESTERN ND A FEW HOURS SOONER THAN
ORIGINALLY THOUGHT. A LITTLE BIT OF ACTIVITY HAS FIRED NORTH OF
THE BOUNDARY IN THE UPPER DEVILS LAKE BASIN...BUT CONVECTION IN
THAT AREA HAS BEEN SUB SEVERE SO FAR. THE STRONGEST ACTIVITY HAS
BEEN IN THE WESTERN PART OF THE STATE WITH THE MAIN
SHORTWAVE...BUT OUR NORTHWESTERN COUNTIES WILL BE UNDER THE GUN IN
THE NEXT FEW HOURS AS THE SHORTWAVE MOVES CLOSER AND THE
ATMOSPHERE CONTINUES TO DESTABILIZE WITH ML CAPE ABOVE 3000 J/KG.
WITH A SFC BOUNDARY HANGING AROUND IN THE AREA...THERE COULD BE
ENOUGH LOW LEVEL HELICITY TO GET STORMS TURNING IF THEY ARE
ISOLATED ENOUGH. THUS...TORNADO WATCH FOR OUR NORTHWEST EARLY ON
IN THIS EVENT.
LATER ON TONIGHT...THE THUNDERSTORMS ARE EXPECTED TO EVOLVE INTO A
COMPLEX MOVING ACROSS THE CWA. WITH PLENTY OF MOISTURE FEEDING
INTO THE COMPLEX AS DEW POINTS RISE INTO THE 70S...AND THE HIGHLY
UNSTABLE AIR MASS...STORMS SHOULD MAINTAIN THEMSELVES AS THEY MOVE
INTO THE RED RIVER VALLEY AND THEN INTO MN. BULK SHEAR VALUES ARE
AROUND 40 TO 50 KTS ALTHOUGH THE LOW LEVEL SHEAR IS NOT NEARLY AS
STRONG AS NEAR THE SFC BOUNDARY. MODEL SOLUTIONS CONTINUE TO POINT
TO A BOW ECHO TYPE PATTERN...AND THE HRRR HAS BEEN CONSISTENT ON
SHOWING HIGH WIND GUSTS ALONG WITH THE STORMS. SIGNS CONTINUE TO
POINT TO A MCS ARRIVING IN THE VALLEY THIS EVENING AND MOVING
EASTWARD INTO MN AFTER MIDNIGHT. DERECHO COMPOSITE ON THE SPC MESO
PAGE IS IN THE 6 TO 8 RANGE...SO WILL KEEP THE DAMAGING WIND TAGS
IN THE GRIDS FOR THIS EVENING.
THE OTHER THREAT WILL BE HEAVY RAINFALL. THE MODELS CONTINUE TO
CRANK OUT BULLSEYES OF OVER 2 INCHES IN A VERY SHORT TIME
PERIOD. WITH PWAT VALUES UP TO 1.5 INCHES AND 850MB MOISTURE
TRANSPORT CONTINUING TO PUSH MORE MOISTURE INTO OUR
COUNTIES...HEAVY RAINFALL CONTINUES TO SEEM REASONABLE. THE ISSUE
WILL BE WHERE IT FALL AND HOW LONG THE PRECIP WILL LAST. MANY OF
THE SHORT RANGE MODELS HAVE BEEN TRENDING FURTHER NORTH WITH THE
TRACK OF THE CONVECTION...WHICH WOULD TAKE IT ALONG THE NORTHERN
EDGE OF THE MOST WARM AND MOIST AIR. THE FLY IN THE OINTMENT WILL
BE THE MOVEMENT OF THE STORMS AS THE COMPLEX ACCELERATES ACROSS
THE CWA. SINCE THERE HAS BEEN FAIRLY DRY WEATHER THE PAST FEW
WEEKS OVER THE VALLEY...WILL HOLD OFF ON ANY FLOOD WATCHES FOR
NOW BUT HAVE TO KEEP AN EYE ON THE STORMS AS THEY APPROACH THE MN
LAKES COUNTRY LATER TONIGHT.
THERE COULD BE SOME LINGERING SHOWERS AND STORMS IN THE EASTERN
COUNTIES TOWARDS TOMORROW MORNING...BUT THERE SHOULD BE A DRYING
TREND AS A COLD FRONT MOVES IN AND HIGH PRESSURE ARRIVES. TUESDAY
WILL BE QUITE A BIT COOLER THAN TODAY...WITH HIGHS IN THE 70S TO
LOW 80S AND DEW POINTS BACK DOWN INTO THE 50S. SFC HIGH PRESSURE
WILL CONTINUE INTO TUESDAY NIGHT AND KEEP LOWS MUCH COOLER THAN
THEY HAVE BEEN THE PAST FEW NIGHTS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 315 PM CDT MON JUL 21 2014
WEDNESDAY TO MONDAY...MODELS IN FAIR AGREEMENT WITH THE EXTENDED
TIME FRAME. OVERALL TEMPS REGIME WILL BE NORMAL TO BELOW NORMAL
TEMPS WITH DRY WEATHER FEATURED MOST DAYS AS SFC HIGH PRESSURE
COMBINED WITH PREDOMINANTLY NW FLOW ALOFT PERSISTS. THE EXCEPTION IS
THURSDAY NIGHT INTO FRIDAY AND SUNDAY WITH CHC THUNDERSTORMS AS
RIDGING SHUNTS BACK TO THE WEST WITH POTENT SHORT WAVE RIDING OVER
THE TOP BRINGING INSTABILITY AND FORCING TO THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1123 PM CDT MON JUL 21 2014
STRONG NON-THUNDERSTORM WINDS WILL AFFECT THE GFK AREA FOR THE
NEXT HOUR OR SO MOVING INTO THE TVF AREA AFT MIDNIGHT. WILL NEED TO
MONITOR AS SOME OF THE HIGH RESOLUTION MODELS MOVE THESE WINDS
INTO BJI IN THE PRE DAWN HOURS. OTHERWISE WILL SEE SOME ISOLD MVFR
CIGS IN STRONGER SHOWERS FOR THE NEXT FEW HOURS. AFTER SUNRISE
MOST AREAS WILL BE VFR THROUGH THE REMAINDER OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...HIGH WIND WARNING UNTIL 4 AM CDT TUESDAY FOR NDZ027-030.
MN...HIGH WIND WARNING UNTIL 4 AM CDT TUESDAY FOR MNZ001-002-013>015-
022.
&&
$$
UPDATE...VOELKER
SHORT TERM...JR
LONG TERM...JK
AVIATION...VOELKER
AREA FORECAST DISCUSSION
NWS PORTLAND OR
202 PM PDT TUE JUL 22 2014
.SYNOPSIS...A LOW PRESSURE SYSTEM WILL BRING AN INCREASING THREAT
OF RAIN SHOWERS AND EVEN A FEW THUNDERSTORMS TO THE AREA TONIGHT AND
ESPECIALLY WEDNESDAY. AFTER A CLOUDY AND WET START TO
WEDNESDAY...EXPECT A MIX OF SUNSHINE AND SHOWERS IN THE AFTERNOON.
DRIER AND MORE SUMMER-LIKE TEMPERATURES ARE EXPECTED TO ARRIVE LATE
THURSDAY AND FRIDAY...BEFORE TEMPERATURES PUSH 90F LATE IN THE
WEEKEND.
&&
.SHORT TERM...THIS EVENING...A VORT MAX...APPARENT IN WATER VAPOR
SATELLITE IMAGERY...NEAR THE BAY AREA WILL LIFT NORTHEASTWARD THIS
AFTERNOON AND EVENING INTO SOUTH CENTRAL OREGON. VISIBLE SATELLITE
IMAGERY SHOWS FAIRLY EXTENSIVE CLOUD COVER OVER THE EASTERN HALF OF
THE FORECAST AREA WITH A FEW BREAKS CREEPING INTO THE CASCADES. A
DESTABILIZING LOWER ATMOSPHERE AND LIFT AHEAD OF THE AFOREMENTIONED
VORT MAX SHOULD ALLOW THUNDERSTORMS TO DEVELOP ACROSS SOUTH CENTRAL
OREGON THIS AFTERNOON. IN FACT...CONVECTION IS BEGINNING TO FIRE
EAST OF THE CENTRAL OREGON CASCADES NEAR BEND. WITH ADDITIONAL
HEATING THIS AFTERNOON...EXPECT SOME OF THIS CONVECTION TO BEGIN
DEVELOPING JUST TO THE WEST OF THE CREST...BUT THERE STILL REMAINS
UNCERTAINTY IN HOW MUCH...IF ANY...WILL DEVELOP. THE LATEST RAP
GUIDANCE SUGGESTS A FEW THUNDERSTORMS WILL BE POSSIBLE LATE THIS
AFTERNOON OVER THE LANE AND LINN COUNTY CASCADES...BUT IF THE
CURRENT MID LEVEL CLOUDS LINGER TOO MUCH LONGER THIS
AFTERNOON...SURFACE BASED CONVECTION WILL LIKELY STAY ENTIRELY EAST
OF OUR FORECAST AREA. THE LATEST HRRR SUPPORTS THE LATTER IDEA. IT
SHOULD BE NOTED THAT IF ANY STORMS DO BREAK THE CAP ON OUR SIDE OF
THE CREST...40-45 KT OF 0-6KM BULK SHEAR AND CAPE VALUES BETWEEN 500-
750 J/KG WILL AID STORM ORGANIZATION. FREQUENT LIGHTNING...AND
POSSIBLY MARGINALLY SEVERE HAIL AND DAMAGING WINDS WOULD BE THE
PRIMARY THREATS OF CONCERN IF STORMS WERE TO MATERIALIZE.
AGAIN...THE MOST LIKELY AREA TO EXPERIENCE SUCH STORMS IS PRIMARILY
NEAR THE CASCADE CREST...SOUTH OF MOUNT JEFFERSON.
FOR TONIGHT...THE LARGE SHORTWAVE TROUGH CURRENTLY NEAR 135W...DUE
WEST OF OREGON...WILL ELONGATE FURTHER TONIGHT...TURNING THE MID
LEVEL FLOW OVER NORTHWEST OREGON SLIGHTLY MORE SOUTHERLY. THE NAM
BRINGS A PIECE OF THE VORT MAX/PV ANOMALY NEAR 130W AND 35N ACROSS
THE AREA LATE TONIGHT. WITH NEGATIVE THETAE LAPSE RATES BETWEEN
700-500MB ADVECTING INTO THE REGION...AND REGION BEING IN THE RIGHT
ENTRANCE/LEFT EXIT REGION OF TWO UPPER LEVEL JETS...WE MAY SEE
SHOWERS AND EVEN A FEW ELEVATED THUNDERSTORMS SPREAD NORTHWARD ACROSS
WESTERN OREGON LATE TONIGHT. HOWEVER...CONFIDENCE IS LOW SO THE
THUNDER MENTION WAS LIMITED TO A SLIGHT CHANCE. THE LATEST HRRR
KEEPS THE BULK OF THE ACTIVITY RIGHT ALONG THE CASCADE CREST AND
POINTS EAST...BUT GIVEN THE PATTERN WILL KEEP THE MENTION IN THE
FORECAST.
THE PREVIOUSLY MENTIONED ELONGATING SHORTWAVE TROUGH NEAR 135W WILL
BEGIN TO PUSH EAST-NORTHEASTWARD ACROSS THE AREA WEDNESDAY. STRONG
MID LEVEL FRONTOGENESIS SHOULD LEAD TO A FAIRLY ORGANIZED NORTH-SOUTH
ORIENTED BAND OF RAIN MOVING EASTWARD INTO THE OREGON COAST WEDNESDAY
MORNING. SOME MODEST MID LEVEL INSTABILITY COUPLED WITH THE DYNAMICS
MAY LEAD TO A FEW LIGHTNING STRIKES ALONG THE FRONT...PARTICULARLY
OVER THE COASTAL WATERS AND NEAR THE COAST LATE TONIGHT INTO
WEDNESDAY MORNING.
THE BAND OF RAIN SHOULD PUSH EASTWARD ACROSS THE AREA WEDNESDAY
MORNING. SUBSIDENCE BEHIND THE MID LEVEL FRONT MAY LEAD TO A RATHER
ABRUPT END TO THE RAIN/CLOUDS EARLY TO MID WEDNESDAY AFTERNOON.
HOWEVER...ANY CLEARING WILL NOT LAST LONG...AS THE LOWER ATMOSPHERE
SHOULD DESTABILIZE QUICKLY...AND A SPRING-LIKE PATTERN OF SCATTERED
SHOWERS AND ISOLATED THUNDERSTORMS WILL LIKELY ENSUE LATE WEDNESDAY
AFTERNOON AND EARLY EVENING. THE GREATEST INSTABILITY WILL BE OVER
THE NORTHERN HALF OF THE FORECAST AREA SO THE MENTION OF THUNDER WAS
INCREASED TO CHANCE WORDING.
WITH A SURFACE LOW PRESSURE LINGERING JUST OFF THE SOUTHWEST
WASHINGTON COAST WEDNESDAY THERE MAY BE A TENDENCY FOR SURFACE WINDS
IN THE WILLAMETTE VALLEY AND ALONG THE LOWER COLUMBIA RIVER TO HAVE A
BIT MORE OF A S TO SSE COMPONENT THAN OTHERWISE EXPECTED. COMBINED
WITH WSW WINDS OF 25 KT AT 900MB AND 40KT AT 500MB...A RAPIDLY
STRENGTHENING UPDRAFT COULD ROTATE BRIEFLY. HOWEVER...CONFIDENCE IS
VERY LOW IN THIS ACTUALLY OCCURRING SOMEWHERE WITHIN THE CWA...BUT
IT WILL STILL BE WORTH MONITORING. THE MORE EXPECTED HAZARDS...
GUSTY WINDS AND SMALL HAIL WERE ADDED TO THE THUNDER WORDING IN THE
GRIDS.
ON THE FIRE FRONT...MOST LOCATIONS ACROSS THE FORECAST AREA SHOULD
SEE WETTING RAINS OF A QUARTER TO HALF INCH WITH A FEW LOCATIONS
LIKELY PUSHING AN INCH OF RAIN...PARTICULARLY ACROSS SOUTHWEST
WASHINGTON. IT SHOULD BE NOTED WETTING RAINS ARE LESS LIKELY TOWARDS
LANE COUNTY...BUT CERTAINLY APPEAR POSSIBLE WEDNESDAY.
EXPECT A DRYING TREND WEDNESDAY NIGHT INTO THURSDAY BEFORE MORE
SEASONABLE WEATHER RETURNS FRIDAY. /NEUMAN
.LONG TERM...HIGH PRESSURE WILL BUILD WESTWARD ACROSS THE CONUS
AMPLIFYING AN UPPER-LEVEL RIDGE THAT WILL SET UP OVER THE
NORTHWESTERN U.S. THIS WILL INCREASE TEMPERATURES BACK TO ABOVE
NORMAL OVER THE WEEKEND. THERE IS A POSSIBLE DISTURBANCE THAT COULD
MOVE THROUGH AS EARLY AS SUNDAY NIGHT...BUT MUCH UNCERTAINTY EXISTS
IN THE TIMING OF THIS SYSTEM AND LOCATION. -MCCOY
&&
.AVIATION...GENERALLY VFR THIS AFTERNOON WITH MOSTLY CLEAR SKIES N
OF A K6S2-KKLS LINE. S OF THIS LINE IS ALSO VFR BUT WITH SCT-BKN
CLOUD DECK GENERALLY ABOVE 6000 FT. THE EXCEPTIONS ARE A FEW LOCAL
MVFR POCKETS ASSOCIATED WITH SHOWERS...AND ALONG THE IMMEDIATE COAST
WHERE LIFR MARINE STRATUS HAS SURGED N FROM K6S2 TO JUST N OF KONP.
EXPECT TRENDS TO PERSIST UNTIL TONIGHT WHEN RAIN ASSOCIATED WITH
APPROACHING LOW PRESSURE SYSTEM MOVES INTO THE REGION STARTING
AROUND 10Z. EXPECT CIGS TO LOWER AFT 12Z...WITH MVFR CIGS AROUND
2000 FT POSSIBLE. LOCAL POCKETS OF IFR POSSIBLE IN HEAVIER
RAIN...AND ALONG THE COAST. HIGHER TERRAIN AND MOUNTAINS OBSCURED
TONIGHT THROUGH MID MORNING WED.
KPDX AND APPROACHES...EXPECT VFR TO CONTINUE THROUGH THIS EVENING
WITH SCATTERED CLOUDS AROUND 3000 FT AND AN OVERCAST DECK ABOVE 5000
FT. SOME LIGHT RAIN POSSIBLE...BUT EXPECT RAIN TO INCREASE AFT 12Z
WITH CIGS LOWERING TO LOW VFR TO HIGHER MVFR. CANNOT RULE OUT SOME
THUNDER DEVELOPMENT OVER ERN APPROACHES THIS EVENING...OR OVER MUCH
OF THE OPS AREA TOMORROW AFTERNOON...BUT NOT ENOUGH CONFIDENCE TO
INCLUDE IN TAF FOR NOW. CULLEN
&&
.MARINE...RELATIVELY QUIET CONDITIONS OVER THE WATERS CONTINUE
TONIGHT AS THE SURFACE GRADIENT REMAINS WEAK IN BETWEEN
SYSTEMS...KEEPING WINDS 15 KT OR LESS. SEAS REMAIN 3-4 FT TODAY WITH
A CONTINUED SMALL W-NW SWELL.
A LOW PRES SYSTEM WILL PASS THROUGH THE WATERS LATE TONIGHT INTO
WED. MODELS HAVE TRENDED TO INDICATE THE POTENTIAL FOR MARGINAL
SMALL CRAFT WINDS TOMORROW AFTERNOON...BOTH S WINDS ALONG THE
COASTAL INNER WATERS AND ALSO OVER MUCH OF THE WATERS AS THE SURFACE
LOW PUSHES ACROSS. CONFIDENCE REMAINS SOMEWHAT LOW AT THIS TIME
HOWEVER SO WILL LET NEXT SHIFT EVALUATE NEXT MODEL CYCLE BEFORE
POTENTIALLY RAISING THE SMALL CRAFT ADVISORY. LATER THIS WEEK...HIGH
PRES REDEVELOPS OVER NE PAC AS THERMAL LOW PRES BUILDS OVER N
CALIFORNIA. THIS WILL BRING A RETURN TO GUSTY N WINDS AND STEEP WIND
DRIVEN SEAS...PARTICULARLY IN THE LATE AFTERNOON AND EVENING
HOURS...FRI THROUGH THE WEEKEND. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WA...NONE.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
955 PM CDT WED JUL 23 2014
.UPDATE...
ISSUED AT 950 PM CDT WED JUL 23 2014
FORECAST FOR TONIGHT STILL LOOKS IN PRETTY GOOD SHAPE. THETAE
ADVECTION STILL PROGGED TO INCREASE TONIGHT...WITH THE COMBINATION OF
THIS INCREASING MOISTURE AND STEEPENING LAPSE RATES ALOFT RESULTING IN
INCREASING INSTABILITY. BASED ON SOUNDINGS...APPEARS LIKE CONVECTION
SHOULD BE BASED AROUND 700 MB. AS BY LATER TONIGHT...PARCELS FROM
THIS LAYER SHOULD BE UNCAPPED...AND REALIZE BETWEEN 1000 AND 1500
J/KG OF CAPE. THESE STORMS SHOULD BE BASED ABOVE THE BEST
SHEAR...HOWEVER RAP SOUNDINGS STILL SUGGEST THEY MAY BE ABLE TO TAP
INTO 30 TO 40 KTS OF EFFECTIVE SHEAR. THUS STILL SEEMS LIKE SMALL
HAIL WOULD BE A POSSIBILITY WITH ANY STORM...WITH A FEW OF THE
STRONGER ONES POSSIBLY PUSHING QUARTERS. LEANING TOWARDS THE
HRRR...RAP AND ECMWF FOR TIMING...BRINGING STORMS INTO THE WEST
AROUND 08Z TO 09Z...APPROACHING INTERSTATE 29 BY 12Z. DO THINK STORMS
WILL BE IN A WEAKINING STATE AS THEY APPROACH INTERSTATE 29 AND POINTS
EAST AS THE LOW LEVEL JET SLACKENS WITH DAYBREAK. THE 0Z NAM SEEMS
OFF AND AN OUTLIER SO WAS DISCOUNTED AT THIS TIME. NOT A SURE BET WE
SEE CONVECTION OVERNIGHT...AS THESE ELEVATED EVENTS ARE ALWAYS
TRICKY...SO WILL STAY BELOW LIKELY POPS...BUT AM DEFINITELY LEANING
TOWARDS US AT LEAST SEEING SCATTERED ACTIVITY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 317 PM CDT WED JUL 23 2014
MAIN FOCUS OF THE SHORT RANGE FORECAST WILL BE LATE TONIGHT AND
THURSDAY MORNING. DEALING WITH A LOT OF THETAE WARM AIR ADVECTION
MOVING INTO...THEN ACROSS OUR FORECAST AREA...FIRST HITTING OUR FAR
WESTERN ZONES OVERNIGHT TONIGHT...THEN EXITING OUR EAST THURSDAY
AFTERNOON. THE THETAE ADVECTION IS MAXIMIZED IN THE 800-750MB LAYER
AT THE TOP OF THE INVERSION. THE INVERSION IS STRONG IN THE LOW
LEVELS...THEREFORE IT IS LIKELY THAT THE STRONG DIRECTIONAL WIND
SHEAR IN THE LOWEST 1.5KM WILL NOT BE TAPPED...LEAVING ELEVATED
SHOWERS OR STORMS WHICH WILL BE TOUGH TO HIT SEVERE CRITERIA LATE
TONIGHT AND EARLY THURSDAY WEST OF I 29. AS FAR AS POPS...STILL DID
NOT HAVE ENOUGH EVIDENCE TO GO LIKELY POPS AT ANY PARTICULAR
LOCATION FROM 06Z TO 18Z THURSDAY. THE VARIOUS HIRES MODELS ARE
SURPRISINGLY DRY...POSSIBLY DUE TO THE AFOREMENTIONED REASON OF THE
PRECIP BEING ELEVATED. THEREFORE ONLY THE GLOBAL MODELS ARE BULLISH
IN DEVELOPING CONVECTION RIGHT TO THE WEST OF THE MID LEVEL RIDGE
AXIS...WHICH DOES NOT LEAD TO A LOT OF CONFIDENCE IS GOING LIKELY OR
CATEGORICAL POPS YET. WILL JUST HAVE TO MONITOR HOW THIS MORPHS
OUT. AS THE PRECIP TRIES TO MOVE EASTWARD BY MIDDAY THURSDAY...LESS
MID LEVEL MOISTURE LOOKS TO BE AVAILABLE IN OUR EASTERN ZONES BY
THURSDAY AFTERNOON WITH WEAKER THETAE ADVECTION.
TEMPERATURES STILL LOOK PLEASANT TONIGHT. HOWEVER 850MB TEMPERATURES
ARE VERY WARM WEST OF THE JAMES RIVER VALLEY ON THURSDAY BEHIND THE
THETAE ADVECTION. THEREFORE AS SKIES CLEAR IN THE EVENING...STILL
LOOKING AT LOWER 90S APPROACHING CENTRAL SD...WITH A DRAMATIC DROP
OFF IN TEMPERATURES HEADING EAST OF THE THERE. IN FACT EAST OF THE
JAMES...WE ARE STILL LOOKING AT READINGS ONLY A COUPLE OF DEGREES
EITHER SIDE OF 80 AS THE COOL HIGH PRESSURE SYSTEM OVER THE GREAT
LAKES STILL GREATLY INFLUENCES THE WEATHER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT WED JUL 23 2014
A RIDGE FLATTENING SHORT WAVE MAY BRING SOME REDEVELOPMENT OF
STORMS THURSDAY NIGHT...ISOLATED WEST AND SCATTERED EAST...MAINLY
FAR EAST WHERE MOST MOISTURE AND INSTABILITY WILL LINGER.
HOWEVER...THIS MOISTURE AND INSTABILITY WILL BE LIMITED AND MOST
OF THE ACTIVITY SHOULD END LATE. ISOLATED STORMS STILL SEEM
POSSIBLE FAR EAST FRIDAY WITH SOME WEAK UPPER AND THERMAL SUPPORT
ASSOCIATED WITH THE LINGERING MOISTURE. ANOTHER SUCH WEAK SYSTEM
MAY BRING A FEW SHOWERS OR STORMS TO THE MISSOURI RIVER AREA LATE
FRIDAY NIGHT AND SATURDAY WHILE MOST OF THE AREA STAYS DRY.
TEMPERATURES FRIDAY AND SATURDAY SHOULD BE MODESTLY WARM AND CLOSE
TO NORMAL WITH 80S HIGHS.
WHAT I DESCRIBED YESTERDAY AS A SECONDARY SHORT WAVE IS NOR A
COOLING CANADIAN UPPER LOW WHICH WILL DIG TOWARD THE WESTERN GREAT
LAKES SUNDAY AND BEGIN TO CARVE OUT A LARGE SCALE TROUGH OVER THE
CENTRAL AND EASTERN USA. A FEW WEAK SHOWERS/STORMS SEEM POSSIBLE
NORTH AND EAST OF FSD SUNDAY AND WILL MENTION WITH SLIGHT CHANCE
POPS. SUNDAY WILL OF COURSE BE COOLER WITH MAINLY 70S HIGHS...80
OR SO SOUTHWEST. A MOSTLY DRY AND SOMEWHAT LASTING COOL PATTERN
THEN SEEMS IN STORE FOR THE AREA...BUT WENT WITH THE EXTENDED
GUIDANCE SLIGHT CHANCE OF STORMS FOR WEDNESDAY AS THE EC DOES SHOW
A SHORT WAVE WITH THE RIGHT TIMING...GFS BEING A LITTLE FASTER.
HOWEVER NOBODY IS GOING TO GET VERY MUCH RAIN WITH THE MOISTURE
VERY LIMITED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 650 PM CDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECETD THROUGH THE TAF PERIOD. SCATTERED
THUNDERSTORMS ARE EXPECTED TO MOVE INTO SOUTH CENTRAL SD LATE TONIGHT
AND SLOWLY TRACK EASTWARD ACROSS THE AREA THROUGH THE DAY THURSDAY.
EXPECT ACTIVITY IN THE KHON AREA FROM 09Z TO 12Z AND INTO THE I29
CORRIDOR AFTER 13Z. AGAIN...COVERAGE WILL BE SCATTERED HOWEVER DID
LEAVE TEMPO MENTION AT ALL 3 TAF SITES. THE HIGH BASED STORMS WILL
LIKELY KEEP CONDITIONS PREDOMINATELY IN VFR...BUT STRONGER GUSTS AND
VERY BRIEF MVFR CONDITIONS WILL BE POSSIBLE IN THE STRONGER STORMS.
BREEZY SOUTH SOUTHEAST WINDS PICK UP AFTER 12Z AND PERIST THROUGH
THE END OF THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...MJ/
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
515 PM MDT WED JUL 23 2014
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 240 PM MDT WED JUL 23 2014
WATER VAPOR IMAGERY SHOWS STRONG UPPER RIDGING ACROSS MUCH OF THE
WRN TO CNTRL CONUS WITH THE MAIN AXIS FROM CO TO MT. AN UPPER LOW IS
SITTING JUST OFFSHORE THE PACIFIC NORTHWEST WITH SW FLOW OVER THE NW
CONUS...THEN TRANSITIONING TO NW FLOW OVER THE CWA. SURFACE ANALYSIS
SHOWS HIGH PRESSURE ACROSS THE UPPER MIDWEST...AND LOW PRESSURE OVER
MONTANA WITH RETURN FLOW OVER THE HIGH PLAINS. TEMPS HAVE STRUGGLED
TO REACH FORECAST HIGHS WITH TEMPS SO FAR IN THE 80S TO LOWER 90S.
STRONG CAP IN PLACE ACROSS MUCH OF THE CWA WILL KEEP DIURNALLY
TRIGGERED CONVECTION FROM DEVELOPING TODAY. THE CAP WAS EXPECTED TO
BE WEAKEST ACROSS NE WY WHERE TEMPS REACHING MID 90S WOULD BE ENOUGH
TO ERODE IT...BUT TEMPS HAVE BEEN SHORT OF THAT SO FAR. CONVECTION
HAS INITIATED OVER LARAMIE RANGE...AND THE LATEST HRRR RUN SHOWS
THIS CONVECTION MOVING N/NE INTO NE WY AND SW SD THIS EVENING. HAVE
PUT IN ISOLATED POPS THIS EVENING TO ACCOUNT FOR THIS...AND POSSIBLE
OTHER CONVECTION THAT MOVES IN FROM THE WEST. BUT OVERALL MOST AREAS
WILL STAY DRY TONIGHT. ANY STORMS THAT MAKE IT INTO THE AREA MAY BE
SEVERE...BUT OVERALL SEVERE THREAT TONIGHT IS VERY LOW.
UPPER RIDGE AXIS SLIDES EASTWARD THURSDAY...CROSSING THE NRN PLAINS.
UPPER LOW WILL CROSS THE NRN ROCKIES WITH THE SURFACE LOW PUSHING
ACROSS THE CWA. TEMPS ARE EXPECTED TO REACH THE 90S TO 100. A COLD
FRONT WILL SLIDE SE...CROSSING THE CWA THU AFTN/NIGHT. A STRONG CAP
IN PLACE AGAIN WILL HELP KEEP CONVECTION FROM DEVELOPING...BUT COULD
SEE ISOLATED STORMS DEVELOP AS THE FRONT PUSHES THROUGH...PERHAPS
ELEVATED STORMS. CANT RULE OUT A COUPLE STORMS BECOMING SEVERE...BUT
OVERALL THREAT LOOKS MINIMAL AGAIN.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 240 PM MDT WED JUL 23 2014
UPPER-LEVEL RIDGE OVER THE REGION BREAKS DOWN BY THE END OF THE WEEK
AS AN UPPER LOW SLIDES SOUTHEAST ACROSS SOUTH CENTRAL CANADA. A WEAK
SHORTWAVE IN ZONAL FLOW TO THE SOUTH COULD BRING ANOTHER CHANCE FOR
SHOWERS AND THUNDERSTORMS TO AT LEAST PORTIONS OF THE CWA FRIDAY
AFTERNOON AND NIGHT.
AS THE UPPER LOW SLIDES FURTHER EAST OF THE REGION...THE UPPER RIDGE
WILL REBUILD OVER THE WESTERN CONUS...BRINGING PREDOMINANTLY
NORTHWEST FLOW TO THE NORTHERN PLAINS. THIS WILL RESULT IN COOLER
TEMPERATURES FOR THE REST OF THE EXTENDED PERIOD...ALONG WITH MAINLY
DRY CONDITIONS FROM SATURDAY THROUGH MONDAY. WEAK SHORTWAVE
DISTURBANCES WILL BEGIN TO ROTATE AROUND THE RIDGE AND INTO THE
NORTHERN PLAINS AGAIN BY THE MIDDLE OF NEXT WEEK. WILL KEEP LOW
CHANCE POPS ACROSS PORTIONS OF THE AREA FROM MONDAY NIGHT THROUGH
WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 512 PM MDT WED JUL 23 2014
ISOLATED THUNDERSTORMS ARE POSSIBLE THROUGH THE NIGHT...WITH LCL
MVFR VSBY AND GUSTY WINDS. OTHERWISE VFR CONDITIONS EXPECTED
THROUGH THURSDAY MORNING. ADDITIONAL THUNDERSTORMS EXPECTED
THURSDAY AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
WY...NONE.
&&
$$
SHORT TERM...13
LONG TERM...26
AVIATION...7
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
1008 PM EDT WED JUL 23 2014
.DISCUSSION...
STORMS TO OUR WEST HAVE HAD A HARD TIME HOLDING TOGETHER AS THEY
SLOWLY MOVE EAST. HRRR SHOWS DECREASING INTENSITY AS WELL...WITH
GREATEST COVERAGE IN NORTHERN AREAS OVERNIGHT. SO POPS WILL BE
LOWERED A BIT WITH THE UPDATE. TOMORROW...THE COLD FRONT WILL BE
MOVING INTO THE AREA LATE IN THE DAY...ALTHOUGH THE BEST FORCING
WITH THE JET WILL BE TO OUR EAST. WHILE THE LOCAL WRF MODEL AND
HRRR SHOW SOME SHOWERS AROUND THROUGH THE DAY AHEAD OF THE
FRONT...COVERAGE APPEARS SCATTERED AT BEST...AND WILL LOWER POPS
DOWN TO A CHANCE. SILGHT ADJUSTMENTS TO HOURLY TEMPERATURES WILL BE
MADE BASED ON LATEST OBS.
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
DGS
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1225 PM CDT TUE JUL 22 2014
.UPDATE...
18Z TAF DISCUSSION.
&&
.AVIATION...
AS NOTED IN MORNING UPDATE...CONVECTION HAS STRUGGLED TO DEVELOP
TODAY ON THE PLATEAU LIKELY DUE TO SOME SUBSIDENCE NOTED ON WATER
VAPOR IMAGERY. NEVERTHELESS...WILL INCLUDE VCSH MENTION AT CSV FOR
POTENTIAL SHOWER DEVELOPMENT. OTHERWISE...VFR CONDITIONS ARE
EXPECTED THE REST OF TODAY WITH LIGHT SOUTH TO SOUTHEAST WINDS AT
ALL AIRPORTS. MVFR VIS DUE TO PATCHY FOG EXPECTED OVERNIGHT AT
CKV/CSV.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 930 AM CDT TUE JUL 22 2014/
UPDATE...
FORECAST LOOKS TO BE ON TRACK AND NO CHANGES WERE MADE.
TEMPERATURES ALREADY WARMING THROUGH THE 80S PER LATEST OBS WITH
DEWPOINTS IN THE UPPER 60S AND 70S...AND A HOT AND HUMID DAY IS
ON TAP WITH AFTERNOON HEAT INDICES TOPPING OUT WELL INTO THE 90S
UP TO NEAR 100 DEGREES. POPS MAY BE A TAD ON THE HIGH SIDE OVER
SOUTH AND EAST ZONES BASED ON LATEST HRRR RUNS BUT WILL LEAVE AS
IS FOR NOW.
SHAMBURGER
PREV DISCUSSION... /ISSUED 606 AM CDT TUE JUL 22 2014/
AVIATION UPDATE...FOR 12Z TAF PACKAGE...
SIMILAR TO YESTERDAY...BEST CHANCE FOR TSRA IMPACTS WILL BE AT
KCSV. INCLUDED VCTS AGAIN AS LOCATION OF STORM DEVELOPMENT IS
UNCLEAR. CLOUD COVER SHOULD PERSIST OVER THE EASTERN HALF OF THE
MID STATE BUT SHOULD STAY AT VFR THROUGHOUT THE PERIOD. ONLY
OBSTRUCTIONS WOULD BE LIGHT TO MODERATE FOG TOWARD THE MORNING
HOURS TOMORROW.
PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 22 2014/
DISCUSSION...
UPPER LOW CONTINUING TO SPIN ACROSS THE DEEP SOUTH NEAR THE FL
PANHANDLE THIS MORNING. PERSISTENT UPPER DIVERGENCE HAS HELPED TO
PROLONG THE NOCTURNAL SHOWER ACTIVITY TO THE EAST OF THE LOW. ACROSS
MIDDLE TN...BROKEN CLOUDINESS STILL PERSISTS ACROSS OUR SOUTHEASTERN
COUNTIES WITH PCLDY SKIES ELSEWHERE.
OVER THE NEXT FEW DAYS...UPPER TROUGHING TO EXPAND ACROSS THE GREAT
LAKES REGION WITH UPPER LEVEL HIGH EXPANSION ACROSS THE SOUTHWESTERN
U.S.. THE PATTERN OVER THE MID STATE WILL THEN MORPH INTO MORE OF A
ROBUST NORTHWESTERLY FLOW ALOFT. IN FACT...A COLD FRONT WILL SLIDE
ACROSS THE AREA WEDNESDAY NIGHT AND BRING A CHANCE OF SHOWERS AND
TSTMS. THE BOUNDARY LOOKS AS THOUGH IT WILL MAKE IT JUST SOUTH OF TN
BY THURSDAY.
SO FOR THE FCST...LOW CONVECTION CHANCES FOR TODAY AS THE WEAKENING
UPPER LOW CONTINUES TO EXERT SOME INFLUENCE ACROSS THE AREA. POPS
WILL INCREASE WED AFTERNOON AND NIGHT. FOR THE NEAR TERM
TEMPS...QUITE WARM TODAY AND AGAIN ON WEDNESDAY AS HEIGHTS
INCREASE...COMPLIMENTS OF THE STRENGTHENING UPPER RIDGE TO OUR WEST.
WE`LL COOL THINGS OFF BY THURSDAY BEHIND THE AFOREMENTIONED FRONTAL
PASSAGE.
IN THE EXT FCST...NORTHWESTERLY FLOW TO CONTINUE THROUGH THE
EXTENDED PERIOD. ANOTHER FRONTAL BOUNDARY WILL IMPACT THE AREA ON
SUNDAY WITH WHAT LOOKS LIKE A DESCENT SHOT OF RAIN. FRONTAL BOUNDARY
WILL PUSH SOUTH OF THE MID STATE ON MONDAY WITH A DEEPENING UPPER
TROUGH INDICATED ACROSS THE EASTERN U.S..
FOR THE EXT TEMPS...WARM AGAIN THIS WEEKEND IN ADVANCE OF THE NEXT
COLD FRONT. SLIGHTLY BELOW NORMAL TEMPS WILL RETURN BY EARLY NEXT
WEEK. DEWPOINTS ARE LOOKING VERY PLEASANT FOR LATE JULY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
930 AM CDT TUE JUL 22 2014
.UPDATE...
FORECAST LOOKS TO BE ON TRACK AND NO CHANGES WERE MADE.
TEMPERATURES ALREADY WARMING THROUGH THE 80S PER LATEST OBS WITH
DEWPOINTS IN THE UPPER 60S AND 70S...AND A HOT AND HUMID DAY IS
ON TAP WITH AFTERNOON HEAT INDICES TOPPING OUT WELL INTO THE 90S
UP TO NEAR 100 DEGREES. POPS MAY BE A TAD ON THE HIGH SIDE OVER
SOUTH AND EAST ZONES BASED ON LATEST HRRR RUNS BUT WILL LEAVE AS
IS FOR NOW.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 606 AM CDT TUE JUL 22 2014/
AVIATION UPDATE...FOR 12Z TAF PACKAGE...
SIMILAR TO YESTERDAY...BEST CHANCE FOR TSRA IMPACTS WILL BE AT
KCSV. INCLUDED VCTS AGAIN AS LOCATION OF STORM DEVELOPMENT IS
UNCLEAR. CLOUD COVER SHOULD PERSIST OVER THE EASTERN HALF OF THE
MID STATE BUT SHOULD STAY AT VFR THROUGHOUT THE PERIOD. ONLY
OBSTRUCTIONS WOULD BE LIGHT TO MODERATE FOG TOWARD THE MORNING
HOURS TOMORROW.
PREV DISCUSSION... /ISSUED 328 AM CDT TUE JUL 22 2014/
DISCUSSION...
UPPER LOW CONTINUING TO SPIN ACROSS THE DEEP SOUTH NEAR THE FL
PANHANDLE THIS MORNING. PERSISTENT UPPER DIVERGENCE HAS HELPED TO
PROLONG THE NOCTURNAL SHOWER ACTIVITY TO THE EAST OF THE LOW. ACROSS
MIDDLE TN...BROKEN CLOUDINESS STILL PERSISTS ACROSS OUR SOUTHEASTERN
COUNTIES WITH PCLDY SKIES ELSEWHERE.
OVER THE NEXT FEW DAYS...UPPER TROUGHING TO EXPAND ACROSS THE GREAT
LAKES REGION WITH UPPER LEVEL HIGH EXPANSION ACROSS THE SOUTHWESTERN
U.S.. THE PATTERN OVER THE MID STATE WILL THEN MORPH INTO MORE OF A
ROBUST NORTHWESTERLY FLOW ALOFT. IN FACT...A COLD FRONT WILL SLIDE
ACROSS THE AREA WEDNESDAY NIGHT AND BRING A CHANCE OF SHOWERS AND
TSTMS. THE BOUNDARY LOOKS AS THOUGH IT WILL MAKE IT JUST SOUTH OF TN
BY THURSDAY.
SO FOR THE FCST...LOW CONVECTION CHANCES FOR TODAY AS THE WEAKENING
UPPER LOW CONTINUES TO EXERT SOME INFLUENCE ACROSS THE AREA. POPS
WILL INCREASE WED AFTERNOON AND NIGHT. FOR THE NEAR TERM
TEMPS...QUITE WARM TODAY AND AGAIN ON WEDNESDAY AS HEIGHTS
INCREASE...COMPLIMENTS OF THE STRENGTHENING UPPER RIDGE TO OUR WEST.
WE`LL COOL THINGS OFF BY THURSDAY BEHIND THE AFOREMENTIONED FRONTAL
PASSAGE.
IN THE EXT FCST...NORTHWESTERLY FLOW TO CONTINUE THROUGH THE
EXTENDED PERIOD. ANOTHER FRONTAL BOUNDARY WILL IMPACT THE AREA ON
SUNDAY WITH WHAT LOOKS LIKE A DESCENT SHOT OF RAIN. FRONTAL BOUNDARY
WILL PUSH SOUTH OF THE MID STATE ON MONDAY WITH A DEEPENING UPPER
TROUGH INDICATED ACROSS THE EASTERN U.S..
FOR THE EXT TEMPS...WARM AGAIN THIS WEEKEND IN ADVANCE OF THE NEXT
COLD FRONT. SLIGHTLY BELOW NORMAL TEMPS WILL RETURN BY EARLY NEXT
WEEK. DEWPOINTS ARE LOOKING VERY PLEASANT FOR LATE JULY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
330 PM CDT TUE JUL 22 2014
.SHORT TERM...
(Tonight and Wednesday)
A strong subtropical ridge remains anchored over the southern
Rockies this afternoon with 500 mb heights approaching 600 dam at
the center of the anticyclone. Isolated thunderstorms have developed
over portions of West TX, basically between Lubbock and San Angelo,
moving southwest toward the Permian Basin. A few cells have
developed within the CWA from near Sweetwater to Sterling City.
Surface temperatures approaching 100 degrees have effectively
removed the cap, tapping into sufficient instability to support
thunderstorms. SPC mesoanalysis from the RAP indicates MLCAPE values
on the order of 1500 J/kg. With weak winds aloft, ordinary cells
will be the convective mode with a classic microburst profile in
place per point soundings. Isolated thunderstorms were carried
through 10 PM generally west of a line from Sweetwater to Mertzon.
Otherwise, we`ll see light winds overnight with temperatures falling
into the low to mid 70s by sunrise. Any thunderstorms lingering into
the evening hours should quickly dissipate by sunset. Temperatures
will again warm to near 100 degrees Wednesday afternoon with light
winds from a generally easterly direction.
Johnson
.LONG TERM...
(Wednesday Night through Tuesday)
An upper ridge centered over northern New Mexico and the northern
Panhandle and extending north into south-central Canada will
continue to minimize our precipitation chances while giving us above
normal temperatures through the coming weekend. A developing upper
trough over the eastern half of then nation will displace the upper
ridge to the west through the by the beginning of next week. As the
upper ridge moves west there will be some relief from the unseasonal
heat as afternoon highs drop from the upper 90s and triple digits
down to the mid and upper 90s beginning next Monday. Models are
indicating a frontal boundary moving as far south as the Red River
Valley on Monday may provide a focus for some convective activity.
At this time the best chances of rainfall would be north of the
forecast area with a slight chance of some activity moving south
into at least our northern CWA. The models are also showing a TUTT
low mowing west over deep south Texas which should keep any
associated rainfall south of our area. In any event, given the
inherent uncertainty in the models this far out, will keep the
forecast dry at this time.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 74 99 74 100 74 / 0 5 5 5 5
San Angelo 73 100 71 101 72 / 5 5 5 10 5
Junction 71 98 71 98 72 / 0 5 5 10 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
918 PM EDT WED JUL 23 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AND
CROSS THE MID ATLANTIC REGION THURSDAY. SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE. DRIER AIR
WILL MOVE INTO THE AREA BEHIND THE FRONT FRIDAY WITH A DAY OR TWO
OF DRY WEATHER...FRIDAY INTO SATURDAY. MOISTURE WILL QUICKLY RETURN
OVER THE WEEKEND WITH HEAT AND HUMIDITY HELPING TO TRIGGER MORE
THUNDERSTORM ACTIVITY. A STRONG FRONT IS EXPECTED TO CROSS THE
AREA LATE SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 918 PM EDT WEDNESDAY...
STORMS IN EASTERN KY/WV ASSOCIATED WITH AN APPROACHING SHORTWAVE
IN THE LOWER OHIO VALLEY PICKING UP INTENSITY THIS EVENING AS THIS
ACTIVITY MOVES INTO UNSTABLE AIR...EVEN WITH THE LOSS OF HEATING.
00Z RNK SOUNDING SHOWED CAPES GREATER THAN 2800 J/KG.
23Z HRRR RUN CONTINUES THE TREND OF STRENGTHENING THIS ACTIVITY
AS IT MOVES INTO SOUTHEAST WV AND THE MOUNTAINS OF VA THIS
EVENING. AS A RESULT...INCREASED POPS IN THIS AREA UNTIL VERY LATE
IN THE NIGHT. WOULD ALSO NOT BE SURPRISED TO SEE STORMS RE- FIRE
ALONG DEVELOPING LEE-SIDE TROF IN THE VA SOUTHSIDE AND NC PIEDMONT
VERY LATE TONIGHT. ALSO INCREASED POPS IN THIS AREA.
NEXT QUESTION WILL BE PRECIPITATION TOMORROW IN ASSOCIATION WITH
APPROACHING COLD FRONT AS UPPER TROUGH AMPLIFIES OVER THE GREAT
LAKES. FRONTAL BOUNDARY WILL MAKE ITS WAY TOWARD THE WESTERN CWA
BY THU MORNING...AND MODELS DEVELOP FAIRLY WIDESPREAD COVERAGE OF
PRECIP ACROSS THE WEST EARLY TOMORROW AND SPREADING EAST ACROSS
THE PIEDMONT AS THE DAY PROGRESSES. THUNDER MAY BE LIMITED BY
CLOUD COVER AND LACK OF INSTABILITY ESPECIALLY ACROSS THE WESTERN
HALF OF THE CWA BUT OVERALL CHANCES FOR CONVECTION WILL INCREASE
OVER THE PIEDMONT LATER IN THE DAY WITH POSSIBLY SOME HEATING AND
MORE INSTABILITY. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AS WELL
WITH STILL VERY HIGH PWATS AHEAD OF THE FRONT. CLOUD COVER AND
HIGH DEWPOINTS WILL KEEP LOWS TONIGHT WELL ABOVE NORMAL RANGING
FROM MID 60S TO LOWER 70S...WITH DIURNAL RANGE LIMITED TOMORROW AS
WELL. HIGHS SHOULD BE 5 TO 8F LOWER THAN TODAYS WARM VALUES.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 500 PM EDT WEDNESDAY...
SURFACE COLD FRONT IS EXPECTED TO SLIP SOUTHEAST OF OUR AREA
THURSDAY NIGHT BEFORE STALLING ALONG THE CAROLINA COAST FRIDAY.
MODELS MAINTAIN CONTINUITY WITH DRY HIGH PRESSURE BUILDING INTO
THE FORECAST AREA FROM THE NORTH. IN SPITE OF THE DRY
AIR...THICKNESSES DO NOT FALL THAT MUCH...SO DO NOT EXPECT MUCH IN
THE WAY OF A TEMPERATURE CHANGE. IF ANYTHING...INCREASED SUNSHINE
WILL HELP BOOST SURFACE TEMPERATURES TO AT LEAST OUR JULY NORMALS
FRIDAY...THEN BEGIN WARMING BACK UP SATURDAY AS SOUTHERLY FLOW
INCREASES BEHIND THE DEPARTING SURFACE HIGH.
FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT LATE IN THE WEEKEND. WILL HAVE TO
MONITOR THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL
SHOWERS AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...
STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.
DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.
ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.
&&
.AVIATION /01Z THURSDAY THROUGH MONDAY/...
AS OF 725 PM EDT WEDNESDAY...
WIDELY SCATTERED CONVECTION IS BEGINNING TO WEAKEN WITH THE LOSS
OF HEATING. FOR THE VERY SHORT TERM...THROUGH 01Z...STORMS MAY
MOVE OVER KDAN. OTHERWISE...VCTS WAS CARRIED FOR THE OTHER TAF
SITES. MEANWHILE...AN UPPER LEVEL SHORT WAVE MOVING ACROSS THE
LOWER OHIO VALLEY HAS TRIGGERED A CLUSTER OF STORMS ACROSS EASTERN
KENTUCKY THIS EVENING. THIS AREA OF SHOWERS AND STORMS WILL
GRADUALLY DIMINISH THIS EVENING...BUT NOT COMPLETELY DISSIPATE. AS
A RESULT...WIDELY SCATTERED STORMS MAY MOVE BACK INTO OUR AREA
LATE TONIGHT...BEFORE DIMINISHING DURING THE PRE-DAWN HOURS.
PATCHY FOG IS AGAIN POSSIBLE AT KLWB AND KBCB LATE TONIGHT WITH
ABUNDANT LOW LEVEL MOISTURE AND LIGHT WINDS. THE COVERAGE OF THE
FOG SHOULD BE WIDESPREAD DUE TO A BLANKET OF VFR CLOUDS.
STORMS WILL RE-DEVELOP EARLY TOMORROW AS A COLD FRONT MOVES
THROUGH THE AREA. THE COVERAGE OF THE CONVECTION IS NOT EXPECTED
TO BE WIDESPREAD ENOUGH TO INCLUDE IN THE TAF SITES...BUT DID ADD
A VCTS AT ALL TAF SITES. THREAT FOR PRECIPITATION SHOULD END EARLY
IN THE AFTERNOON IN THE WEST AS THE FRONT EXITS THE FORECAST AREA
BETWEEN 18Z THUR AND 00Z FRI...LEAVING VFR CONDITIONS.
EXTENDED AVIATION DISCUSSION...
AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. OVERALL EXPECT SUB VFR AT TIMES THURSDAY WITH SHRA/TSRA
AND MAYBE SOME FOG THU NIGHT...FOLLOWED BY VFR FRI- SAT OUTSIDE OF
ANY VALLEY FOG AT KLWB/KBCB EACH MORNING.
&&
.EQUIPMENT...
AS OF 715 PM EDT WEDNESDAY...
KFCX RADAR IS BACK UP AND IS OPERATING AT FULL STRENGTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/PH
NEAR TERM...PH
SHORT TERM...PM
LONG TERM...PM
AVIATION...PC/PH
EQUIPMENT...PM
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
355 PM CDT TUE JUL 22 2014
.TONIGHT...FORECAST CONFIDENCE - MEDIUM.
HEAT INDEX VALUES ENDED UP EXCEEDING 100 FROM MADISON AND WEST LATE
THIS AFTERNOON AFTER THE LOW CLOUDS CLEARED AWAY. MADISON REACHED A
HIGH OF 90 OR GREATER FOR THE FIRST TIME THIS YEAR.
SPC TRIMMED THE SLIGHT RISK A LITTLE FURTHER SOUTHEAST AGAIN WITH
THE 3 PM UPDATE. MESOSCALE MODELS CONTINUE TO KEEP THE AREA CAPPED
/NO CONVECTION/ UNTIL THE FRONT GETS INTO FAR SOUTHEAST WI OR EVEN
NORTHEAST IL LATE THIS AFTERNOON BETWEEN 22Z AND 00Z. SPC
MESOANALYSIS RAP IS SHOWING ERODING CIN ALONG THE FRONT IN CENTRAL
WI...SO I WILL CONTINUE THE SLIGHT CHANCE ALONG THE FRONT AS IT
MOVES SOUTHEAST THROUGH THE MKX FORECAST AREA. WE CANNOT RULE STORM
DEVELOPMENT GIVEN THE HIGH DEWPOINTS...SURFACE FRONT...VERY HIGH
CAPE OVER 4000 J/KG AND SIGNS OF SLIGHT UPSTREAM COOLING AT 700-
850MB.
THE INHIBITING FACTORS FOR CONVECTION ARE: THE CAP. THE WESTERLY
WINDS JUST AHEAD OF THE SURFACE AND 850MB FRONTS ARE LIMITING THE
LOW LEVEL CONVERGENCE. WE WILL HAVE TO SIT AND WAIT TO SEE IF THE
CAP BREAKS AS THE SURFACE FRONT REACHES SOUTHEAST WI. THERE IS
LIMITED BULK SHEAR OF 25 TO 30 KNOTS. ISOLATED SEVERE HAIL AND WINDS
WILL BE POSSIBLE. PRECIPITABLE WATER VALUES AROUND 2 WILL LEAD TO
VERY HEAVY RAIN WITH ANY THUNDERSTORMS. URBAN FLOODING WILL BE
POSSIBLE.
PRECIP CHANCES EXIT WITH FRONT LATE THIS EVENING WITH COOLER AND
DRIER AIR MOVING IN. TEMPERATURES DOWN INTO THE LOWER 60S AND DEW
POINTS IN THE MID TO UPPER 50S BY WEDNESDAY MORNING.
WEDNESDAY...FORECAST CONFIDENCE HIGH.
HIGH PRESSURE...DRIER AND AND COOLER TEMPERATURES WILL SETTLE INTO
THE REGION. LOOK FOR DIURNAL CUMULUS CLOUDS TO DEVELOP BY LATE
MORNING AND LINGER THROUGH EARLY AFTERNOON DUE TO STEEP LOW LEVEL
LAPSE RATES. STEADY NORTH WINDS WILL GRADUALLY DIMINISH DURING THE
AFTERNOON. WINDS WILL BE HIGHEST NEAR THE LAKE.
.WEDNESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - HIGH.
THE QUIET AND LESS HUMID WEATHER WILL CONTINUE THROUGH THURSDAY AS A
HIGH PRESSURE RIDGE AND DRIER DEWPOINTS HOLD SWAY ACROSS THE WESTERN
GTLAKES. EXPECT PATCHY FOG LATER WED NIGHT DUE TO LIGHT BOUNDARY
LAYER WINDS AND LINGERING DEWPOINTS IN THE LOW TO MID 50S. EXPECT
SOME LOCATIONS TO DIP DOWN INTO THE 40S LATE WED NIGHT.
THURSDAY NIGHT AND FRIDAY...FORECAST CONFIDENCE - LOW.
CONSIDERABLE DIFFERENCES BETWEEN SHORT TERM GUIDANCE IN HANDLING OF
LOW TO MID LEVEL FORCING DURING THIS PERIOD. GFS ONLY GUIDANCE IN
BRINGING CONVECTION ASSOCIATED WITH WARM FRONT SOUTHEAST ACROSS
SOUTHERN WI ON FRIDAY. MEANWHILE...CANADIAN MAINTAINS WMFNT
ORIENTATION FARTHER SOUTH ACROSS MO/SRN IL. LATEST ECMWF A BLEND
BETWEEN THE TWO WHICH CLIPS PORTIONS OF SW INTO SOUTH CENTRAL WI
WITH CONVECTION GENERATED BY MOISTURE AND WARM AIR ADVECTION RETURN.
WL LEAN TOWARD MORE SOUTHERN SOLUTION AND KEEP LOWER POPS IN THE
WEST AND SOUTH DURING THIS PERIOD AS LEANING TOWARD DRIER SOLUTION
WITH BETTER CHANCE FOR CONVECTION FARTHER WEST AND SOUTH. ECMWF AND
NAM SHOW STRONGER W-NW FLOW STEERING FLOW ACROSS SRN WI WHILE GFS
STRONGER SW. GFS REMAINS OUTLIER AT THIS POINT. TOO MANY
DESCREPANCIES SO CONFIDENCE REMAINS LOW.
.FRIDAY NIGHT THROUGH TUESDAY - FORECAST CONFIDENCE - LOW
TRENDING TOWARD MEDIUM.
LIKE NCEP WPC BLENDED...PREFER ENSEMBLE OF MEDIUM RANGE GUIDANCE FOR
THIS FORECAST PERIOD. MOST OF THE MEDIUM RANGE GUIDANCE IS SHOWING
SOMEWHAT BETTER AGREEMENT THAN 24 HOURS AGO...AND ARE CONVERGING ON
A SOMEWHAT SIMILAR SOLUTION.
WEAKENING MID-LEVEL RIDGE OVER NORTHERN PLAINS CONTINUES TO WEAKEN
AND FLATTEN EARLY THIS FORECAST PERIOD AS LOW PRESSURE MOVES ACROSS
SOUTHERN CANADA. GFS CONTINUES TO PHASE THIS SYSTEM WITH EASTERN
CANADA LONG WAVE TROUGH A BIT QUICKER THAN CANADIAN/ECMWF SOLUTIONS.
GFS BRINGS SHORT WAVE ACROSS WI SAT NIGHT INTO SUN...WHILE OTHER
SOLUTIONS ARE SLOWER...LATER SUNDAY INTO SUNDAY NIGHT. HENCE WL
NEED TO KEEP CHANCE POPS GOING OVER THE WEEKEND AS UPPER LEVEL
TROUGH MOVES THROUGH REGION.
BY MONDAY...NORTHWEST WINDS IN THE LOW TO MID LEVELS WILL HAVE
USHERED COOLER AND DRIER AIR INTO SRN WI...HOWEVER WEAK RIPPLES IN
FAST NORTHERLY FLOW MAY GENERATE -SHRA.
&&
.AVIATION/00Z TAFS/...
A COLD FRONT MOVING SOUTHEAST THROUGH SOUTHERN WI WILL BRING A
CHANCE OF SHOWERS AND THUNDERSTORMS ALONG IT LATE THIS AFTERNOON.
THE CHANCE WILL INCREASE AS THE FRONT GETS INTO FAR SOUTHEAST
WISCONSIN AROUND 6 PM...ESPECIALLY KENOSHA AND THEN SOUTHWARD INTO
NORTHEAST IL.
ANY THUNDERSTORMS WILL BRING MVFR CIGS/VSBYS IF THEY DEVELOP. EXPECT
VERY HEAVY RAIN. WINDS WILL BECOME NORTHWEST BEHIND THE FRONT...
THEN NORTH TO NORTHEAST OVERNIGHT. EXPECT A PERIOD OF BROKEN VFR
CUMULUS CLOUDS WED MIDDAY ON STEADY NORTHERLY WINDS.
&&
.MARINE...SMALL CRAFT ADVISORY IN EFFECT UNTIL 9 PM. WINDS AND WAVES
WILL RISE ON WEDNESDAY IN THE WAKE OF THE COLD FRONT. A SMALL CRAFT
ADVISORY WILL LIKELY BE NEEDED.
&&
BEACHES...MILWAUKEE...RACINE AND KENOSHA COUNTIES WILL BE IN A HIGH
RISK OF SWIMMING HAZARDS LATER TONIGHT AND WEDNESDAY. SHEBOYGAN AND
OZAUKEE COUNTY BEACHES WILL BE IN A MODERATE RISK OF SWIMMING
HAZARDS TONIGHT AND HIGH RISK WEDNESDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVY LMZ643>646 UNTIL 02Z/23.
&&
$$
TONIGHT/WEDNESDAY AND AVIATION/MARINE/BEACHES...MRC
WEDNESDAY NIGHT THROUGH TUESDAY...MBK
CONTINUES WITH THE MODEL. SEE THE PREVIOUS FORECAST DISCUSSION FOR
MORE DETAILS ABOUT THE AFTERNOON CONVECTION.
PREV DISCUSSION... /ISSUED 506 AM CDT TUE JUL 22 2014/
TODAY AND TONIGHT...FORECAST CONFIDENCE IS MEDIUM.
RADAR RETURNS OVER WEST CENTRAL AND SW WISCONSIN ON LEADING EDGE OF
850 MB WARM ADVECTION...IN REGION OF DECENT CONVERGENCE. HOWEVER NO
GROUND TRUTH AS PRECIP IS DEVELOPING ABOVE DRY...WARM LAYER BETWEEN
750MB AND 650 MB RESULTING IN VIRGA ONLY MAKING IT DOWN TO AROUND 5K
FT ABOVE THE GROUND.
THIS CAPPING INVERSION WILL BE PROBLEMATIC DURING THE DAY AS WARM
ADVECTION CONTINUES TO STRENGTHEN THE CAP AHEAD OF THE COLD FRONT.
CONSENSUS SFC-BASED CAPE INCREASES TO BETWEEN 2500 AND 3000 J/KG BUT
CIN REMAINS IN THE 150 TO 200 J/KG RANGE. NAM DOES SHOW AN ERODING
CAP TOWARDS THE 22Z-00Z TIME FRAME...BUT IT HAS DEW POINTS
APPROACHING 80F AND SB-CAPE APPROACHING 5000 J/KG. FOLLOWING LOWER
CONSENSUS TEMPS/DEW POINTS TRENDS TOWARD THE MORE CAPPED SOLUTION.
BULK SHEAR OF 25 TO 30 KTS ACCOMPANIES MEAGER 500 MB HEIGHT
FALLS/MID-LEVEL COOLING AS SRN EDGE OF SHORT WAVE TROUGH PASSES
THROUGH LEADS TO THE POTENTIAL FOR SOME ISOLATED/SCATTERED SEVERE
STORMS IF CAP IS BROKEN AS FRONT PASSES THROUGH. WILL LIMIT POPS TO
MID-HIGH CHANCE CATEGORY LATE THIS AFTERNOON AND EVENING.
FORECAST TEMPERATURES IN THE UPPER 80S TO LOW 90S WITH LOW-MID 70S
DEW POINTS KEEP APPARENT TEMPERATURES BELOW HEAT ADVISORY HEADLINES
EXCEPT FOR A SMALL PORTION OF THE WESTERN CWA AROUND LONE ROCK. NOT
CONFIDENT IN HIGHS REACHING THE FORECAST IF CLOUDS REMAIN THICKER
THAN EXPECTED AND TOO SMALL AN AREA FOR A HEADLINE. WILL CONTINUE
ISSUANCE OF SPS HIGHLIGHTING THE NEAR-ADVISORY WARMTH.
PRECIP CHANCES EXIT WITH FRONT LATE THIS EVENING WITH COOLER AND
DRIER AIR MOVING IN. TEMPERATURES DOWN INTO THE LOWER 60S AND DEW
POINTS IN THE MID TO UPPER 50S BY WEDNESDAY MORNING.
WEDNESDAY AND THURSDAY...FORECAST CONFIDENCE...HIGH
HIGH PRESSURE IS EXPECTED TO BRING DRY WEATHER AND AMPLE SUNSHINE
WEDNESDAY AND THURSDAY. IT SHOULD BE A COUPLE OF VERY PLEASANT
DAYS WITH HIGHS IN THE 70S MOST PLACES. THREW IN SOME LOW POPS
SOUTHWEST THURSDAY NIGHT...AS THE HIGH HEADS EAST AND WARM
ADVECTION MAY KICK OFF A FEW STORMS.
FRIDAY THROUGH MONDAY...FORECAST CONFIDENCE...MEDIUM
A SERIES OF SHORTWAVES ARE EXPECTED TO BRING SHOWER/STORM CHANCES
TO SOUTHERN WISCONSIN AT TIMES FRIDAY THROUGH THE WEEKEND. MODELS
STILL HAVE SOME DETAILS TO WORK OUT...SO LEFT CHANCE POPS THROUGH
THE WEEKEND. LOOKS LIKE TEMPS WILL BE NEAR NORMAL THROUGH SUNDAY.
IT LOOKS LIKE THERE WILL BE LESS AVAILABLE MOISTURE EARLY NEXT
WEEK...BUT STILL WENT WITH SOME LOW POPS MONDAY AS MODELS ARE
ADVERTISING A WEAK WAVE. TEMPS SHOULD BE A COUPLE DEGREES COOLER
AS WELL.
AVIATION/12Z TAFS/...
EXPECT VFR CONDITIONS THROUGH THE FORECAST. CURRENT BAND OF HIGH-
BASED PRECIPITATION ON RADAR OVER SOUTHERN WISCONSIN STRUGGLING
TO REACH THE GROUND...THOUGH A FEW SPOTS HAVE REPORTED VERY LIGHT
RAIN/SPRINKLES WITH ONLY TRACE AMOUNTS. BEST CHANCE FOR SHOWERS
AND STORMS WILL BE ALONG COLD FRONT...BUT WILL HAVE TO BREAK
THROUGH WARM MID-LEVEL CAP. WILL KEEP VICINITY THUNDERSTORMS IN
TAFS FOR LATE AFTERNOON/EVENING...WHICH WILL BRING MVFR CIGS/VSBYS
IF/WHEN THEY DEVELOP. GUSTY SOUTH TO SOUTHWEST WINDS AHEAD OF
FRONT WILL LOWER AND TURN NORTH TO NORTHEAST BEHIND FRONT TONIGHT.
MARINE...HAVE LEFT SMALL CRAFT ADVISORY HOURS FROM PREVIOUS
FORECAST. EXPECT SOUTH TO SOUTHWEST WIND GUSTS TO REACH CRITERIA
MID-MORNING AND CONTINUE INTO LATE THIS AFTERNOON BEFORE LOWERING
AS COLD FRONT/SURFACE TROUGH MOVES THROUGH. WAVES WILL BE SLOWER
TO LOWER...SO 9 PM END TIME IS LOOKING GOOD. WINDS AND WAVES WILL
RISE ON WEDNESDAY AS HIGH PRESSURE BUILDS IN
BEACHES...SOUTH TO SOUTHWEST WINDS WILL GUST TO BETWEEN 20 AND 25
KNOTS TODAY. WHILE SOUTHERN ZONES WILL ONLY SEE WAVES BUILD TO 1
TO 3 FEET AT MOST ALONG THE BEACHES...THE NORTHERN 2 ZONES MAY SEE
3 TO 5 FOOT WAVES...ESPECIALLY AT SOUTH-FACING BEACHES. THIS
PLACES SHEBOYGAN AND OZAUKEE COUNTY BEACHES IN A MODERATE RISK OF
SWIMMING HAZARDS.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 PM CDT THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...MRC
TODAY/TONIGHT AND AVIATION/MARINE...REM
WEDNESDAY THROUGH MONDAY...DDV
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1216 PM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND
NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS
SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF
THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS
MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN
THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE
22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE
CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST
NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT
SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN
PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING
ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET
SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES
CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS
TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM
EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE
COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN
CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS
MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT
AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS
ACTIVITY IS REACHING THE GROUND.
FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS
ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH
WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW
BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE
TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB
LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE
DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT
UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR
BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS
AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE
CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER
DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING
AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT
AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A
20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE
LATE AFTERNOON INTO THE EARLY EVENING.
LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS
AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S
TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD
BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S
AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE
ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A
HEAT ADVISORY TO HANDLE THIS.
THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER
CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE
REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM
MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE
WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS
FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND
ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM
HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE
UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF
CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE
FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME
GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE
DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND
GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES
FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE
LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER
NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN
CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER
CENTRAL WISCONSIN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1216 PM CDT TUE JUL 22 2014
DRIER AIR AND NORTHWEST WINDS WERE SPREADING SOUTHEAST ACROSS THE
AREA AT MID DAY...WITH WINDS BECOMING NORTHWEST IN THE 10KG G15-20KT
RANGE. DEW POINTS WERE DROPPING FROM THE LOW-MID 70S TO THE MID 60S.
HOWEVER A BAND OF 2K-3K FT STRATO-CU WAS LOCATED ACROSS NORTHWEST WI
TO SOUTHWEST MN...BEHIND THE COLD FRONT BRINGING IN THE DRIER AIR.
THIS BAND OF CLOUDS THINNING THE PAST COUPLE HOURS BUT STILL APPEARS
THERE WILL BE SOME BKN025 CIGS AT KRST THRU 20Z. WITH CONTINUED
THINNING APPEARS LOWER CLOUDS AT KLSE WILL REMAIN SCT AS THE BAND
MOVES ACROSS IN THE 19-21Z PERIOD.
GOOD VFR CONDITIONS AND DECREASING NORTHWEST TO NORTH WINDS THEN
EXPECTED FOR LATER THIS AFTERNOON THRU TONIGHT AND FOR WED AS DRIER
CANADIAN HIGH PRESSURE BUILDS INTO THE UPPER MIDWEST. LIGHT NORTH
WINDS TONIGHT SHOULD KEEP ANY RADIATIONAL VALLEY BR/FG IN THE 09-13Z
TIME-FRAME TO A MINIMUM AND LEFT THIS OUT OF THE KLSE TAF.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
WIZ054-055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ029-030.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
600 AM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND
NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS
SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF
THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS
MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN
THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE
22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE
CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST
NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT
SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN
PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING
ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET
SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES
CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS
TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM
EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE
COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN
CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS
MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT
AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS
ACTIVITY IS REACHING THE GROUND.
FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS
ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH
WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW
BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE
TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB
LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE
DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT
UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR
BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS
AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE
CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER
DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING
AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT
AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A
20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE
LATE AFTERNOON INTO THE EARLY EVENING.
LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS
AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S
TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD
BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S
AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE
ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A
HEAT ADVISORY TO HANDLE THIS.
THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER
CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE
REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM
MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE
WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS
FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND
ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM
HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE
UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF
CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE
FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME
GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE
DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND
GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES
FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE
LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER
NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN
CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER
CENTRAL WISCONSIN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 600 AM CDT TUE JUL 22 2014
IMMEDIATE CONCERNS FOR EARLY THIS MORNING IS THE POTENTIAL FOR A FEW
HOUR PERIOD OF MVFR CIGS/VSBYS. SATELLITE IMAGERY AND SFC OBS
INDICATING A DROP IN VSBYS IN A CLEAR SLOT AHEAD OF AN APPROACHING
COLD FRONT. SOME STRATUS ALSO STARTING TO DEVELOP-EXTEND INTO THIS
REGION. BOTH COULD IMPACT KRST/KLSE...WITH A HIGHER LIKELIHOOD AT
KRST. BUFKIT SOUNDINGS WOULD SUGGEST THAT ANY CIG THAT DID MOVE IN
WOULD QUICKLY MIX OUT BETWEEN 14-16Z. WILL ADD CIG MENTION INTO A
TEMPO GROUP FOR KRST FOR NOW...AND LEAVE OUT AT KLSE WERE CONFIDENCE
IS A BIT LESS. SOME FUZZ WILL LINGER AT KRST UNTIL MID MORNING. VFR
CONDITIONS SHOULD THEN BE THE RULE INTO TONIGHT.
FOR WED MORNING...SOME SUGGESTIONS IN THE NAM KLSE SOUNDING OF
VALLEY FOG POTENTIAL. DECOUPLING WILL RESULT IN A LIGHT WIND THIS
EVENING...BUT DIRECTION COULD BE NORTHWEST. IF SO...LOCALE RESEARCH
SUGGESTS DENSE FOG IS NOT LIKELY. ALSO...WINDS JUST OFF THE GROUND
ARE EXPECTED TO BE 10+ KTS. ALSO NOT FAVORABLE. SO...WILL LEAVE ANY
MENTION OUT OF THE FORECAST FOR NOW...BUT POTENTIAL SHOULD BE
MONITORED.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
WIZ054-055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ029-030.
&&
$$
SHORT TERM...04
LONG TERM....04
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
253 AM CDT TUE JUL 22 2014
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
ORGANIZED LINE OF CONVECTION WORKING EAST ACROSS MINNESOTA AND
NORTHERN WISCONSIN THIS MORNING. LOCAL AND REGIONAL RADARS
SHOWING SOME ECHOES DEVELOPING SOUTH OF THE LINE ON THE EDGE OF
THE MOISTURE TRANSPORT AXIS. LOOKING AT THE MESO SCALE MODELS THIS
MORNING...THE HRRR AND RAP ARE PRETTY MUCH USELESS AS THEY TURN
THE SYSTEM MORE NORTHEAST AND DISSIPATE IT WAY TOO QUICKLY. THE
22.00Z HI-RES ARW AND NMM LOOK MUCH MORE REASONABLE WITH THE
CONVECTIVE COMPLEX AND CONTINUE MOVING IT EAST TAKING IT JUST
NORTH OF THE FORECAST AREA. LOOKING AT THE 22.00Z NAM BUFKIT
SOUNDING FOR LADYSMITH...THIS MAKES SENSE AS THE CAP HOLDS IN
PLACE THROUGH THE REMAINDER OF THE NIGHT. AS FOR THE DEVELOPING
ECHOES OVER THE FORECAST AREA...THESE ARE JUST STARTING TO GET
SOME SPRINKLES TO THE GROUND. THE HI-RES NMM SHOWS THE ECHOES
CONTINUING THROUGH THE NIGHT UNTIL THE MOISTURE TRANSPORT STARTS
TO BEND MORE OFF TO THE EAST BUT DOES NOT REALLY SHOW THEM
EXPANDING AND KEEPS THEM SCATTERED. WITH THE MAIN CONVECTIVE
COMPLEX EXPECTED TO MOVE BY TO THE NORTH...HAVE LOWERED THE RAIN
CHANCES ACROSS THE NORTH DOWN TO ABOUT 40 PERCENT FOR THIS
MORNING. TO HANDLE THE LIGHT ECHOES...WILL SHOW ABOUT A 20 PERCENT
AS FAR SOUTH AS I90 UNLESS OBSERVATIONS START INDICATING THAT THIS
ACTIVITY IS REACHING THE GROUND.
FOR THE REMAINDER OF TODAY...THE MAIN SHORT WAVE TROUGH WILL PASS
ACROSS LAKE SUPERIOR INTO ONTARIO. A SECONDARY SHORT WAVE TROUGH
WILL DROP ACROSS THE REGION DURING THE AFTERNOON AS THE FLOW
BECOMES NORTHWEST ALOFT. IT APPEARS THAT THIS SECONDARY SHORT WAVE
TROUGH WILL ONLY PRODUCE SOME WEAK PV ADVECTION IN THE 500-300 MB
LAYER AS IT MOVES ACROSS. HOWEVER...THE FORCING FROM THIS WAVE
DOES NOT LOOK LIKE IT WILL BE ABLE TO INTERACT WITH THE FRONT
UNTIL IT HAS MOVED PAST THE AREA. THE NAM BUFKIT SOUNDING FOR
BLUE RIVER INDICATES THE CAP WILL HOLD IN PLACE UNTIL LATE THIS
AFTERNOON WHILE THE 22.00Z GFS HOLDS IT INTO THE EVENING. WITH THE
CAP REMAINING IN PLACE...ALL THE MODELS SUGGEST FURTHER
DEVELOPMENT ALONG THE FRONT DOES NOT TAKE PLACE UNTIL THIS EVENING
AND SOUTH OF THE FORECAST AREA. JUST IN CASE THE NAM IS CORRECT
AND THE CAP DISSIPATES A LITTLE SOONER...HAVE OPTED TO HOLD ONTO A
20 TO 30 PERCENT RAIN CHANCE ACROSS THE SOUTHEAST SECTIONS FOR THE
LATE AFTERNOON INTO THE EARLY EVENING.
LOOKS LIKE TEMPERATURES WILL HAVE A GOOD OPPORTUNITY TO WARM THIS
AFTERNOON AHEAD OF THE FRONT. HIGH TEMPERATURES IN THE UPPER 80S
TO LOWER 90S OVER THE SOUTHEAST HALF OF THE AREA ARE A PRETTY GOOD
BET. DEW POINTS ARE EXPECTED TO AGAIN GET INTO THE MIDDLE 70S
AHEAD OF THE FRONT...WHICH WILL PUSH THE HEAT INDEX IN THE
ADVISORY RANGE ACROSS THE SOUTHERN SECTIONS AND WILL BE ISSUING A
HEAT ADVISORY TO HANDLE THIS.
THE REST OF THE PERIOD LOOKS TO BE QUIET WITH COOLER AND DRIER
CONDITIONS AS A LARGE AREA OF HIGH PRESSURE MOVES ACROSS THE
REGION FROM CANADA TOWARD THE OHIO RIVER VALLEY.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 253 AM CDT TUE JUL 22 2014
SOME DIFFERENCES BETWEEN THE MODELS ON HOW FAST THE NEXT SYSTEM
MOVES INTO THE REGION. THE UPPER LEVEL RIDGE THAT BUILDS OVER THE
WESTERN PART OF THE COUNTRY OVER THE FIRST HALF OF THE WEEK...GETS
FLATTENED AS AN UPPER LEVEL LOW MOVES ONSHORE FROM THE PACIFIC AND
ACROSS SOUTHERN CANADA. THE DIFFERENCES IN THE MODELS COMES FROM
HOW FAST SHORT WAVE TROUGHS WILL CUT THROUGH THE FLOW BETWEEN THE
UPPER LEVEL LOW AND THE RIDGE. IT LOOKS LIKE THE 22.00Z ECMWF
CONTINUES TO BE FASTER THAN THE GFS AND 22.00Z GEM ON BRINGING THE
FIRST SHORT WAVE THROUGH. HOWEVER...ALL OF THEM SHOW THE SAME
GENERAL PATTERN WITH THE WAVE AND A SURFACE LOW TRACKING FROM THE
DAKOTAS SOUTHEAST TOWARD THE OHIO RIVER VALLEY. WITH THE GFS AND
GEM BEING A LITTLE SLOWER...WILL INDICATE THE HIGHEST RAIN CHANCES
FRIDAY INTO FRIDAY NIGHT. THE NEXT SHORT WAVE TROUGH AND SURFACE
LOW STILL LOOK TO COME THROUGH OVER THE WEEKEND AND TRACK FARTHER
NORTHEAST THAN THE FRIDAY SYSTEM. THIS SYSTEM WILL BRING SOME RAIN
CHANCES TO THE ENTIRE AREA FOR SUNDAY WITH THE BETTER CHANCES OVER
CENTRAL WISCONSIN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM CDT MON JUL 21 2014
THE MAIN FOCUS FOR THE TAF SITES IS WITH THE POTENTIAL FOR
CONVECTION TUESDAY MORNING ALONG WITH WHEN A COLD FRONT WILL MOVE
THROUGH. SHOWERS AND STORMS LOOK LIKE THEY WILL BE STAYING NORTH
OF THE TAF SITES...SO HAVE REMOVED THE THUNDER CHANCES FROM THE
TAFS. A BKN BAND OF 3-4KFT CUMULUS APPEARS TO BE SHIFTING OFF TO
THE EAST AND SHOULD BE OUT OF LSE OVER THE NEXT HOUR OR SO. HIGH
LEVEL CLOUD COVER WILL LINGER THROUGH TUESDAY MORNING BEFORE THE
COLD FRONT MOVES THROUGH AND SWINGS WINDS AROUND THE NORTHWEST.
WINDS WILL EVENTUALLY BECOME LIGHT IN THE EVENING HOURS ON TUESDAY
AS HIGH PRESSURE MOVES IN FROM THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
WIZ054-055-061.
MN...NONE.
IA...HEAT ADVISORY FROM NOON TODAY TO 7 PM CDT THIS EVENING FOR
IAZ029-030.
&&
$$
SHORT TERM...04
LONG TERM...04
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 PM CDT MON JUL 21 2014
.UPDATE...
ISSUED AT 918 PM CDT MON JUL 21 2014
THE MCS CURRENTLY DEVELOPING ACROSS EASTERN NORTH DAKOTA INTO
NORTHWEST MINNESOTA IS THE FORECAST CONCERN FOR THE LOCAL AREA.
LATEST GUIDANCE SUGGESTS THAT THE 700-800 MB CAP WILL REMAIN
STRONG ENOUGH TO KEEP THE COMPLEX FROM DROPPING TOO MUCH
SOUTHEAST. CORFIDI VECTORS AND MCS MOTION WOULD SUGGEST A PATH
MORE ACROSS NORTHERN MINNESOTA INTO NORTHERN WISCONSIN...WITH A
SLIGHT POSSIBILITY OF CLIPPING THE FAR NORTHERN CWA. THUS...THE
THREAT FOR A DAMAGING WIND EVENT FOR THE AREA CONTINUES TO DROP.
THERE ARE SUGGESTIONS THAT THERE WILL BE AN INCREASE IN 850-700
MB MOISTURE TRANSPORT OVERNIGHT...AND THAT THE CAP WILL WEAKEN
ENOUGH TO ALLOW SHOWERS/STORMS TO DEVELOP TOWARD 10-12Z...MAINLY
ACROSS WESTERN INTO CENTRAL WISCONSIN. THIS WOULD BE IN
CONJUNCTION WITH THE PASSING MCS TO THE NORTH. THE LATEST RUNS OF
THE RAP/HRRR SUGGEST THIS IDEA COULD OCCUR AS WELL...SO HAVE
ADJUSTED PRECIPITATION CHANCES TO MAINLY AFTER 08Z FOR WESTERN
INTO CENTRAL WISCONSIN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 331 PM CDT MON JUL 21 2014
MAIN FORECAST CONCERNS ARE SEVERE THUNDERSTORM POTENTIAL LATE
TONIGHT OVER NORTH CENTRAL WISCONSIN AND HEAT INDEX VALUES LATE
TUESDAY MORNING INTO TUESDAY AFTERNOON OVER PORTIONS OF NORTHEAST
IOWA INTO FAR SOUTHWEST WISCONSIN.
LATEST RADAR IMAGERY SHOWS THUNDERSTORMS DEVELOPING OVER PORTIONS OF
CENTRAL NORTH DAKOTA. THESE SHOULD BE THE BIRTH OF A THUNDERSTORM
COMPLEX THAT WILL RACE EAST TONIGHT ACROSS NORTHERN MINNESOTA INTO
PORTIONS OF NORTHERN WISCONSIN AND UPPER MICHIGAN. MOST OF THE
MESOSCALE MODEL GUIDANCE KEEPS THIS COMPLEX NORTH OF THE INTERSTATE
94 CORRIDOR. HOWEVER...THE NAM...WHICH IS A MAJOR OUTLIER AT THIS
TIME...SHOWS CONVECTION FIRING OVER WEST CENTRAL MINNESOTA LATE
THIS AFTERNOON INTO THIS EVENING THEN THIS CONVECTION RACES
SOUTHEAST INTO THE FORECAST AREA. LOOKING AT FORECAST SOUNDINGS
OVER MUCH OF THE FORECAST AREA THERE IS AN IMPRESSIVE ELEVATED
MIXED LAYER WHICH IS RESULTING IN A STRONG CAP IN PLACE. THE
CONVECTION WILL HAVE TO OVERCOME THIS CAP AND WITHOUT A STRONG LOW
LEVEL JET THIS WILL BE DIFFICULT TO DO. THE 17Z HRRR SHOWS A FEW
CELLS MAKING IN INTO WEST CENTRAL WISCONSIN AFTER MIDNIGHT SO WILL
HAVE TO SEE IF THIS PANS OUT. HAVE DECIDED TO REDUCE POPS ACROSS
MUCH OF THE FORECAST AREA TONIGHT WITH THE EXCEPTION OF CLARK AND
TAYLOR COUNTY WHERE THE MCS COULD IMPACT THESE AREAS WITH DAMAGING
WINDS THE MAY CONCERN.
A COLD FRONT THEN SAGS SOUTH ACROSS THE AREA ON TUESDAY. SOME OF
THE WARMEST AIR AT 925 MB MAKES IT INTO NORTHEAST IOWA INTO FAR
SOUTHWEST WISCONSIN WHERE 925 MB TEMPERATURES CLIMB TO AROUND 27
C. TEMPERATURES COULD CLIMB TO THE UPPER 80S TO AROUND 90 OVER
PORTIONS OF NORTHEAST IOWA AND FAR SOUTHWEST WISCONSIN. THESE
TEMPERATURES COMBINED WITH DEWPOINTS IN THE MID TO UPPER 70S WILL
PRODUCE HEAT INDEX VALUES AROUND 100. THIS HEAT LOOKS TO BE VERY
SHORT LIVED WITH THE COLD FRONT SWEEPING THROUGH LATE TOMORROW
AFTERNOON SO HAVE HAVE NOT ISSUED A HEAT ADVISORY AT THIS TIME.
SHOWERS AND STORMS WILL BE POSSIBLE ALONG THE FRONT TUESDAY
AFTERNOON INTO EARLY TUESDAY EVENING BUT AGAIN THE CAP WILL BE A
MAJOR LIMITING FACTOR. MOST OF THE FORECAST MODELS KEEP THE AREA
DRY. GIVEN THE AMOUNT OF SURFACE BASED CAPE THAT DEVELOPS AHEAD
OF THE FRONT OVER NORTHEAST IOWA AND FAR SOUTHWEST
WISCONSIN...COULD SEE A STORM OR TWO DEVELOP ALONG THE FRONT LATE
IN THE AFTERNOON SO WILL KEEP CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGH THE LATE AFTERNOON INTO THE EARLY EVENING.
VERY COMFORTABLE TEMPERATURES RETURN IN THE WAKE OF THE FRONT
TUESDAY NIGHT WITH TEMPERATURES FALLING INTO THE UPPER 50S TO
LOWER 60S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 331 PM CDT MON JUL 21 2014
HIGH PRESSURE BUILDS INTO THE REGION TUESDAY NIGHT AND REMAINS OVER
THE REGION THROUGH THURSDAY PROVIDING QUIET AND COMFORTABLE CONDITIONS.
PLAN ON HIGHS IN THE 70S WITH LOWS IN THE 50S TO AROUND 60. WITH
THE HIGH OVERHEAD WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR
SOME PATCHY VALLEY FOG DURING THE LATE NIGHT AND EARLY MORNING
HOURS THURSDAY MORNING...BUT CLOUD COVER COULD PREVENT THIS FROM
FORMING. CHANCES FOR SHOWERS AND THUNDERSTORMS RETURN THURSDAY
NIGHT INTO THE WEEKEND AS ACTIVE NORTHWEST FLOW SETS UP ACROSS THE
REGION. A TROUGH DIVES INTO THE UPPER MISSISSIPPI RIVER VALLEY ON
SUNDAY AND DEEPENS A LARGER SCALE TROUGH OVER THE ENTIRE GREAT
LAKES REGION EARLY NEXT WEEK. THIS WOULD SET THE STAGE FOR WELL
BELOW NORMAL TEMPERATURES OVER THE AREA GOING INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1146 PM CDT MON JUL 21 2014
THE MAIN FOCUS FOR THE TAF SITES IS WITH THE POTENTIAL FOR
CONVECTION TUESDAY MORNING ALONG WITH WHEN A COLD FRONT WILL MOVE
THROUGH. SHOWERS AND STORMS LOOK LIKE THEY WILL BE STAYING NORTH
OF THE TAF SITES...SO HAVE REMOVED THE THUNDER CHANCES FROM THE
TAFS. A BKN BAND OF 3-4KFT CUMULUS APPEARS TO BE SHIFTING OFF TO
THE EAST AND SHOULD BE OUT OF LSE OVER THE NEXT HOUR OR SO. HIGH
LEVEL CLOUD COVER WILL LINGER THROUGH TUESDAY MORNING BEFORE THE
COLD FRONT MOVES THROUGH AND SWINGS WINDS AROUND THE NORTHWEST.
WINDS WILL EVENTUALLY BECOME LIGHT IN THE EVENING HOURS ON TUESDAY
AS HIGH PRESSURE MOVES IN FROM THE WEST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE.......ZT
SHORT TERM...WETENKAMP
LONG TERM....WETENKAMP
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
359 PM MDT TUE JUL 22 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY NIGHT)
ISSUED AT 306 PM MDT TUE JUL 22 2014
FAR LESS COVERAGE OF CU COMPARED TO THE SAME TIME MONDAY WHICH
SURELY IS INDICATIVE OF THE WARMER TEMPS ALOFT. SFC MOISTURE HAS
INCREASED BEHIND LAST NIGHTS WEAK BOUNDARY...WITH THE 50F
ISODROSOTHERM BANKED UP TO THE FRONT RANGE. AM BEGINNING TO SEE SOME
WEAK CONVECTIVE DEVELOPMENT MAINLY IN THE VICINITY OF THE NRN
LARAMIE RANGE...AND SOME NR THE SNOWY AND SOUTHERN LARAMIE RANGE
TOO. MESOANALYSIS SHOWS A PRETTY HEALTHY CAPPING INVERSION REMAINS
IN PLACE...ESPECIALLY OVR THE ERN PLAINS. EXPECT THIS CAP CONTINUE
TO ERODE THRU THE AFTERNOON. THE STRONGER CAP WILL MEAN DEEP
CONVECTION WILL BE A BIT LATER IN DEVELOPING...WHICH ACCORDING TO
THE HRRR WILL BE BETWEEN 3-6 PM. LARAMIE COUNTY AND THE SOUTHERN END
OF GOSHEN/PLATTE COUNTIES LOOK TO SEE THE BEST CHANCE INITIALLY.
WILL SEE ADDL DEVELOPMENT OVR NORTHEAST WYOMING DIVE SOUTHEAST INTO
FAR EAST CENTRAL WYOMING AND THE NRN NEBRASKA PANHANDLE THIS
EVENING. IT IS THIS AREA WHERE SEVERE POTENTIAL WILL BE GREATEST
WITH SBCAPES OF AROUND 2000 J/KG ONCE THE CAP BREAKS. THIS
CONVECTION WILL DISSIPATE BY AROUND SUNSET.
ATTENTION THEN TURNS TO A BETTER CHANCE FOR SEVERE THUNDERSTORM
DEVELOPMENT WEDNESDAY AFTERNOON. THERMODYNAMIC PROFILES WILL BE MORE
CONDUCIVE FOR THUNDERSTORM DEVELOPMENT WEDNESDAY AS MID-LEVEL
HEIGHTS/TEMPS FALL WITH THE APPROACH OF SHORTWAVE ENERGY. THIS WILL
MEAN LESS OF A CAP AND A LIKELY EARLIER START TO CONVECTIVE
INITIATION...WHICH SHOULD OCCUR OVR THE SNOWY/SIERRA MADRE RANGES BY
MIDDAY. PROGD SBCAPES OVR THE ERN PLAINS CLIMB ABOVE 3000 J/KG
WEDNESDAY AFTERNOON AND WHEN COMBINED WITH DEEP LAYER SHEAR OF 25-30
KNOTS SHOULD BE SUFFICIENT FOR SOME CONVECTIVE ACTIVITY BECOMING
SEVERE. STORMS WILL SPREAD ONTO THE SOUTHEAST WYOMING PLAINS
WEDNESDAY AFTERNOON AND INTO THE WESTERN NEBRASKA PANHANDLE DURING
THE EVENING. AREAS OVR THE SOUTHERN PANHANDLE MAY BE INFLUENCED A
BIT TOO MUCH BY THE CAP...WHICH MAY LIMIT CONVECTIVE STRENGTH THERE.
CONVECTION AGAIN WILL WANE WITH LOSS OF INSOLATION.
FIRST SHORTWAVE PUSHES THRU THURSDAY MORNING WITH A TRAILING
SHORTWAVE POISED TO MOVE THRU THURSDAY AFTERNOON. INSTABILITY AXIS
WILL BE FLATTENED AND WEAKENED BY THE INITIAL SHORTWAVE. SO EXPECT A
LESS FAVORABLE ENVIRONMENT FOR SEVERE THUNDERSTORM POTENTIAL. EVEN
SO...WEAK INSTABILITY PARAMETERS WILL BE SUFFICIENT FOR AT LEAST
SOME ISOLATED CONVECTIVE POTENTIAL. THURSDAY WILL BE THE WARMEST DAY
OF THE PERIOD WITH HIGH TEMPERATURES THAT WILL AGAIN REACH 90S AT
MOST LOCATION AND LOW TRIPLE DIGITS OVER LOWER ELEVATIONS OF THE
WESTERN NEBRASKA PANHANDLE.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 306 PM MDT TUE JUL 22 2014
HIGH PRESSURE CONTINUES TO REMAIN DOMINANT OVER THE FOUR CORNERS
REGION BUT BEGINS TO ERODE TO THE SOUTH OVER THE WKND. FAIRLY POTENT
TROUGH OF LOW PRESSURE MOVES ACROSS THE SOUTHERN CANADIAN PROVINCES
AND BRINGS A SERIES OF ASSOCIATED COOL FRONTS ACROSS THE AREA (THE
STRONGEST FRONT WILL BE SAT EVENING). UPSLOPE FLOW LOOKS TO DEVELOP
BY FRI AFTN AS DEW POINTS APPROACH THE MID 50S OVER THE PANHANDLE.
COULD SEE SOME ISOLATED SHOWERS AND THUNDERSTORMS DURING THIS
TIMEFRAME BOTH FRI AND SAT SO HAVE KEPT SOME SLIGHT POPS IN THE
FCST. THE ECMWF IS MORE MOIST THAN THE GFS ATTM AND GENERATES A
BETTER COVERAGE OF STORMS EACH AFTN AND EVENING. TEMPS BEGIN TO COOL
TO MORE SEASONABLE LEVELS IN THE LOW TO MID 80S FOR SUNDAY...BUT THE
RIDGE BEGINS TO BUILD BACK INTO THE AREA AND TEMPS SHOULD WARM TO
THE MID 80S BY MONDAY FOR SOUTHEASTERN WY AND NEAR 90 FOR AREAS OF
THE PANHANDLE AS 700 MB TEMPS WARM TO NEAR 15C.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY MORNING)
ISSUED AT 1143 AM MDT TUE JUL 22 2014
VFR CONDITIONS THROUGH THE TAF PERIOD. WINDS WILL TURN TO THE
SOUTHEAST THIS AFTN BUT GUSTS SHOULD GENERALLY REMAIN BELOW 20
KTS. WHILE MUCH OF THE AREA WILL NOT SEE STORMS THIS AFTN AND
EVENING...ISOLATED TSTMS WILL BE POSSIBLE ACROSS THE NORTHERN
NEBRASKA PANHANDLE...MAINLY FROM 01-05Z. GUSTY WINDS AND BRIEF
HEAVY RAIN WILL BE THE MAIN THREATS FROM THESE STORMS.
&&
.FIRE WEATHER...
ISSUED AT 306 PM MDT TUE JUL 22 2014
WINDS HAVE HELD BELOW CRITICAL THRESHOLDS THUS FAR TODAY...DESPITE
RELATIVE HUMIDITIES THAT HAVE DROPPED BELOW 15 PERCENT. SOME
ISOLATED SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DEVELOP OVER
LARAMIE COUNTY LATE THIS AFTERNOON AND OVER EXTREME EAST CENTRAL
WYOMING AND THE NORTHERN NEBRASKA PANHANDLE THIS EVENING. WEDNESDAY
WILL PROVIDE A BETTER OPPORTUNITY FOR AFTERNOON AND EVENING
THUNDERSTORMS ACROSS THE DISTRICT...SOME OF WHICH COULD POTENTIALLY
BECOME SEVERE IN LOCATIONS EAST OF THE LARAMIE RANGE. DRIER AND
BREEZIER CONDITIONS WILL EXIST OVER WESTERN CARBON AND CONVERSE
COUNTIES ON WEDNESDAY. CONDITIONS WILL LIKELY BECOME NEAR CRITICAL
IN THESE AREAS WEDNESDAY. THURSDAY LOOKS POTENTIALLY MORE CRITICAL
OVER WESTERN CARBON AND CONVERSE COUNTIES AND WILL LIKELY NEED TO
ISSUE A HEADLINE IN TIME. AFTERNOON AND EVENING SHOWER AND
THUNDERSTORM CHANCES WILL CONTINUE THURSDAY AND FRIDAY MAINLY FOR
AREAS EAST OF THE LARAMIE RANGE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...NONE.
&&
$$
SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...FINCH
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1100 PM MDT WED JUL 23 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
BOUNDARY FROM EARLY MORNING CONVECTION ACROSS NORTHEAST COLORADO
HAS PUSHED BACK WESTWARD INTO KIOWA AND NORTHEAST BENT COUNTY AS
OF 1 PM...AND EXTENDS TO THE NORTHEAST TO NEAR KLIC...TO
KDEN...THEN BACK TO THE SOUTHWEST TOWARDS THE NORTHERN BORDER OF
TELLER COUNTY. WHILE WESTERN PORTIONS OF THIS BOUNDARY HAVE
STALLED AND IS BEGINNING TO SHIFT BACK NORTHWARD...EASTERN
PORTIONS OF THIS BOUNDARY CONTINUE TO BACKDOOR WESTWARD INTO THE
SOUTHEAST PLAINS WITH DEW POINTS IN THE 60S BEHIND IT. TO THE
SOUTH OF THIS BOUNDARY...SOUTHERLY WINDS ARE INCREASING...BUT DEW
POINTS HAVE BEEN MORE STUBBORN TO MIX OUT TODAY...AND REMAIN IN
THE 40S AND 50S. STILL THINK THERE IS SOME FURTHER MIXING OUT THAT
WILL OCCUR DURING THE AFTERNOON AND EVENING HOURS...BUT HRRR AND
RAP13 APPEAR TO BE DRYING OUT DEW POINTS TOO VIGOROUSLY...EVEN IN
THE LATEST RUNS. THIS ELEVATES CONCERNS FOR POTENTIAL FOR A SLOW
MOVING THUNDERSTORM TO DEVELOP OVER THE WALDO BURN SCAR SOMETIME
THIS AFTERNOON AND EVENING. ANOTHER AREA OF CONCERN WILL BE ACROSS
THE WEST FORK BURN SCAR....THOUGH LATEST OBS OUT THAT WAY SHOW DEW
POINTS HAVE ALREADY DROPPED INTO THE 30S AND CONVECTION DOES NOT
LOOK ALL THAT STRONG YET. THUS APPEARS MAIN AREA TO MONITOR WILL
BE ACROSS TELLER AND EL PASO COUNTIES THIS EVENING...AND THREAT
AREA MAY END UP BEING JUST TO THE NORTH OF TELLER COUNTY. WILL
ALSO HAVE TO WATCH THE BOUNDARY ACROSS THE FAR SOUTHEAST PLAINS
FOR THUNDERSTORM DEVELOPMENT. MIXED LAYER CAPES ALONG THIS
BOUNDARY ARE AROUND 4000 J/KG OFF THE SPC MESO ANALYSIS...HOWEVER
THERE IS ALSO A FAIR OF CIN BEHIND THE OUTFLOW BOUNDARY AS WELL.
NONE OF THE SHORT RANGE MODELS ARE DEVELOPING THUNDERSTORMS ALONG
THIS BOUNDARY BENEATH THE UPPER HIGH. DEEP LAYER SHEAR IS
WEAK...SO ANY SEVERE POTENTIAL WOULD BE MORE LIKELY TO BE FROM A
PULSE TYPE SEVERE WHICH COULD PERSIST IF A STORM CAN ANCHOR TO THE
BOUNDARY. BUT WITH THE LACK OF FORCING THIS SEEMS TO BE A LOW END
PROBABILITY OF OCCURRENCE. HOWEVER...IT DEFINITELY BEARS WATCHING.
THUNDERSTORMS SHOULD DIMINISH THIS EVENING WITH LOSS OF
HEATING...THOUGH WITH MONSOON PLUME OVER THE MOUNTAINS WILL MAINTAIN
SOME ISOLATED POPS THROUGH THE NIGHT AS IS TYPICAL THIS TIME OF
YEAR.
FOR THURSDAY...UPPER RIDGE FLATTENS WHICH PUTS THE MONSOON PLUME
ALOFT ACROSS MOST OF CO. MODELS SUGGEST A WEAK SHORTWAVE WILL MOVE
OVERTOP THE RIDGE WHICH WILL HELP TO FIRE OFF THUNDERSTORMS ACROSS
THE MOUNTAINS THEN SEND THEM TO THE EAST ACROSS THE ADJACENT PLAINS.
BOTH NAM AND GFS SUGGEST NORTHERN PORTION SO OF THE FORECAST AREA
MAY SEE A BETTER CHANCE FOR THUNDERSTORMS TOMORROW...AND THIS WILL
PUT WALDO UNDER A SLIGHTLY HIGHER THREAT THAN TODAY. AGAIN...DEEP
LAYER SHEARS ARE WEAK...SO THREAT FOR SEVERE WEATHER OVERALL LOOKS
LOW. STORM MOTIONS SHOULD BE A LITTLE FASTER AND TOWARDS THE
EAST...BUT PROBABLY NOT FAST ENOUGH TO MITIGATE THE POTENTIAL
LOCALIZED FLASH FLOODING ON THE BURN SCARS SHOULD THEY TAKE AN
UNLUCKY STRIKE. SO ANOTHER DAY OF MONITORING THE WALDO BURN SCAR
CLOSELY WILL BE IN STORE. STORM STRENGTH WILL DEPEND ON HOW MUCH
SURFACE DEW POINTS MIX OUT...AND WITH WESTERLY FLOW OVER THE
AREA...UPPER 30S TO LOWER 40 DEW POINTS LOOK LIKELY...WHICH SHOULD
KEEP CAPE VALUES GENERALLY BELOW 1000 J/KG. HAVE KEPT HIGHER POPS
ACROSS THE CENTRAL MOUNTAINS AND PIKES PEAK REGION FOR TOMORROW.
OTHERWISE...WESTERLY FLOW SHOULD HELP DRY OUT SURFACE DEW POINTS
ACROSS THE PLAINS...WHICH SHOULD LIMIT CAPE AND THUNDERSTORM
COVERAGE. THIS MAY ALSO BE SUFFICIENT TO BOOST TEMPS INTO THE LOWER
100S ACROSS THE LOWER ARKANSAS RIVER VALLEY. HOWEVER...AN INCREASE
IN CONVECTIVE CLOUD COVER MAY ALSO LIMIT HEATING SOME...ESPECIALLY
FOR THE I-25 CORRIDOR SO HAVE KEPT PUB BELOW THE CENTURY MARK FOR
NOW. LOCATIONS FARTHER EAST SHOULD HAVE AN EASIER TIME OF HITTING
AROUND 100. -KT
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 308 PM MDT WED JUL 23 2014
...MORE MONSOON NEXT WEEK...
THE EXTENDED FORECAST LOOKS PRETTY TYPICAL FOR LATE JULY...AS
AN UPPER RIDGE DOMINATES THE WEATHER THROUGH NEXT WEEK. BUT THERE
WILL BE TWO DISTINCT PATTERNS THAT WILL SHAPE OUR WEATHER.
THE FIRST HALF OF THE PERIOD WILL BE A CONTINUATION OF THE HOT AND
RELATIVELY DRY WEATHER WE HAVE BEEN EXPERIENCING THIS WEEK. A WEAK
FRONTAL SURGE WILL USHER IN A LITTLE MORE UPSLOPE THU NIGHT INTO
FRIDAY...AND THIS MAY HELP GENERATE A FEW MORE SHOWERS AND STORMS
OVER THE AREA FRIDAY AFTERNOON AND EVENING. WE WILL STILL BE UNDER
THE UPPER RIDGE AXIS...AND WITH TEMPS ALOFT STILL PRETTY
HIGH...EXPECT ANOTHER HOT DAY WITH TEMPS SOARING INTO THE HIGH 90S
OVER THE PLAINS. MAYBE EVEN A DEGREE OR TWO HOTTER ON SATURDAY
AS THE RIDGE EXPANDS A BIT TO THE NORTH.
THEN...A FRONTAL SURGE ASSOCIATED WITH A STRONG TROUGH DIGGING
OVER ERN CANADA WILL BRING A CHANGE TO OUR WEATHER BEGINNING
SUNDAY. IT LOOKS SOMEWHAT SIMILAR TO OUR LAST PERIOD OF WET
WEATHER...AS A STRONG UPSLOPE REGIME SETS UP OVER THE PLAINS AND
DEWPOINTS CLIMB FROM THE 40S AND LOWER 50S TO THE UPPER 50S AND
EVEN 60 DEGREE MARK BY EARLY NEXT WEEK. AT THIS TIME...IT LOOKS
LIKE SUNDAY AFTERNOON-EVE...WITH THE INITIAL SURGE...AND THEN
TUESDAY AFTERNOON AND EVE...WITH A SECONDARY PUSH OVER THE CENTRAL
PLAINS...WILL BE THE WETTEST DAYS. EVERY DAY WILL SEE THE
POTENTIAL FOR SOME LOCALLY HEAVY RAINFALL...BUT THOSE PERIODS ARE
PROBABLY THE HIGHEST THREAT FOR THE BURN SCARS AND POTENTIAL FLASH
FLOODING. COULD ALSO SEE SOME SVR STORMS ESPECIALLY ON TUESDAY OVR
THE PLAINS...AS NW FLOW ALOFT INCREASES A BIT AS THE RIDGE MOVE
WWD. TEMPS SHOULD SETTLE BACK INTO THE 70S AND 80S FROM SUNDAY
ONWARD THROUGH NEXT WEEK AS COOLER AND MOISTER AIR ARRIVES FROM
THE NORTH. ROSE
&&
.AVIATION...
ISSUED AT 1100 PM MDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECTED TO CONTINUE OVER THE KALS...KCOS AND
KPUB TAF SITES TONIGHT AS A STRONG UPPER RIDGE REMAINS CENTERED
OVER SOUTHERN COLORADO
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
412 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONTAL BOUNDARY WILL CONTINUE MOVING OFFSHORE
TODAY. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TONIGHT AND
ON FRIDAY. THE HIGH PRESSURE SYSTEM WILL MOVE EAST OF THE REGION ON
SATURDAY AND BE FOLLOWED BY THE PASSAGE OF A WARM FRONT FROM THE
SOUTH BY SATURDAY NIGHT AND BE LOCATED TO OUR NORTH ON SUNDAY.
ANOTHER COLD FRONTAL BOUNDARY THEN WILL SWEEP FROM WEST TO EAST
ACROSS THE REGION ON MONDAY. A HIGH PRESSURE SYSTEM WILL BUILD IN
BEHIND THE COLD FRONT FOR THE MIDDLE HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CDFNT WAS WORKING ITS WAY ACRS THE REGION AND SHOULD BEE OFFSHORE
LATER THIS MRNG. HIGH PRES WILL SLOWLY BUILD IN BEHIND THE FRONT.
HOWEVER, SOME GUID STILL INDICATES THAT THERE IS ENOUGH INSTABILITY
AND WITH THE FRONT LOCATED JUST TO OUR S, THERE COULD BE SOME
SHOWERS AND SCT TSTMS, MAINLY OVER SRN AREAS FROM LATER THIS MRNG
INTO ERLY EVE. BOTH THE NAM/WRF AND GFS INDICATE AT LEAST SOME
POTENTIAL FOR PRECIP WHILE THE ECMWF IS DRIER. FOR NOW, WILL CARRY
SOME LOW POPS.
THE HRRR ALSO HAS SOME PRECIP MOVG IN FROM THE S AND W THIS AM.
THERE IS SOME LIGHT STUFF OVER PA AND MD, BUT THE HRRR APPEARS A BIT
OVERDONE.
OVERALL GUID TEMPS LOOK REASONABLE AND WERE GENLY FOLLOWED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
HIGH PRES WILL BUILD EWD AND INTO THE AREA TONIGHT. ANY PRECIP WILL
END EARLY AND THE SKY WILL CLEAR. OVERALL, A QUIET NIGHT IS IN
STORE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY AND FRIDAY NIGHT: HIGH PRESSURE GLIDES EAST FROM THE OHIO
VALLEY INTO OUR REGION. VARIABLE WINDS, PLENTY OF SUNSHINE AND NOT
THAT HOT SINCE THIS AIRMASS WILL BE COMING FROM CANADA! LITTLE
SPREAD IN THE MODELS ON MOST IF NOT ALL WEATHER ELEMENTS. TRICKIEST
PART OF THIS PERIOD IS HOW MUCH RADIATIONAL COOLING CAN OCCUR IN
RURAL AREAS BEFORE THE FLOW TURNS MORE SOUTHERLY BY SATURDAY.
OPTED TO GO A TOUCH COOLER THAN MEX/MAV/MET IN A FEW SPOTS WITH
LOWS FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT: A WARM FRONT APPROACHES THE REGION FROM
THE SOUTH AND WITH A DEPARTING HIGH PRESSURE THE FLOW TURNS
SOUTHERLY. MODELED MOMENTUM TRANSFER SUGGESTS SOME GUSTS CLOSE TO 20
MPH ARE POSSIBLE IN THE AFTERNOON, WENT HIGHER THAN A STANDARD
125% FOR WIND GUSTS. MID-LEVEL AND SURFACE TEMPERATURES LOOK TO
RESPOND IN KIND AFTER THE WARM FRONTAL PASSAGE, 925 MB TEMPS NEAR 20-22C
SHOULD YIELD SURFACE TEMPERATURES JUST UNDER 90 FOR PHL AND IN THE
80`S ELSEWHERE ACROSS THE REGION. HUMIDITY IS ON THE RISE BUT THIS
WILL BE LIKE MORE TYPICAL JULY HEAT WITH HEAT INDEX VALUES WELL
UNDER ADVISORY LEVELS. THE WARM FRONT MAY PROVIDE ENOUGH LIFT FOR
SOME SCATTERED SHOWERS AND THUNDERSTORMS FOCUSED ACROSS THE
NORTHERN PART OF THE REGION. THE 21Z SREF AND THE LAST TWO ECMWF
RUNS HAVE THESE PINED DOWN WELL. INCREASING CIN COUPLED WITH 700
MB TEMPS NEAR 10C COULD ALLOW FOR THE FORMATION OF A WEAK CAP
ACROSS THE SOUTHERN PART OF THE REGION, BEING FURTHER AWAY LOWER
CHANCE POPS WERE WARRANTED WHEN COMPARED TO LOCATIONS FURTHER
NORTH.
SUNDAY AND SUNDAY NIGHT: CONTINUED WEST-SOUTHWEST FLOW IN THE WARM
SECTOR. THE LAST FEW GFS RUNS HAVE BEEN MORE AGGRESSIVE WITH
CONVECTION BY THE AFTERNOON AND EVENING HOURS. A COMMON THEME THIS
SUMMER. THINK THE GFS IS TO AGGRESSIVE WITH THIS. HOWEVER, STORM
CHANCES SHOULD INCREASE AS THE MAIN LOW PRESSURE SYSTEM AND COLD
FRONT APPROACH THE REGION. GOOD AGREEMENT AMONG THE GFS ENSEMBLES,
ECMWF ENSEMBLE MEAN AND THE OPERATIONAL MODELS THAT THE HIGHEST
CHANCE WILL BE SUNDAY NIGHT. MAINTAINED LOW END LIKELY POPS ACROSS THE
NORTH AND HIGH END CHANCE ACROSS THE SOUTH. FOR QPF STAYED CLOSE TO
THE SREF AND ECMWF SIMILAR TO SATURDAY. THOUGH DID RAISE IT SLIGHTLY
TO ACCOUNT FOR THE MORE AGGRESSIVE GFS. TEMPERATURES MAY BE RAIN
COOLED SUNDAY BUT DID NOT GO IN THAT DIRECTION ATTM. FAIR SHOT AT 90
FOR PHL WITH SLIGHTLY WARMER MODELED MID-LEVEL TEMPERATURES THAN
SATURDAY.
MONDAY AND MONDAY NIGHT: THE COLD FRONT MOVES THROUGH LIKELY MONDAY
AFTERNOON. HOWEVER THIS SHOULD BE TO LITTLE TO LATE IN TERMS OF
ANOTHER ROUND OF SHOWERS AND STORMS. THE MAIN CAPE AXIS IS LIKELY TO
OFFSHORE AT THIS TIME AND LITTLE IS LEFT FOR A TRIGGER BESIDES THE
ACTUAL FRONTAL BOUNDARY. HOWEVER MAINTAINED LOW CHANCE POPS SINCE THE
FRONT WILL STILL BE IN THE REGION. CLEARED CONDITIONS OUT MONDAY
NIGHT WITH A RETURN TO WESTERLY FLOW. ANOTHER GUSTY DAY AS ONCE
MODELED MOMENTUM TRANSFER SHOWS POTENTIAL FOR SOME GUSTS NEAR 20
MPH.
TUESDAY AND WEDNESDAY: ANOTHER CANADIAN AIRMASS COMES DOWN INTO THE
REGION AS THE SAME GENERAL PATTERN FROM THE WINTERTIME CONTINUES
WITH FEW BREAKS. COOL NORTHWESTERLY FLOW WILL BE IN PLACE AS MOST
LOCATIONS STRUGGLE TO 80 FOR A HIGH. EVEN WITH THIS ABNORMALLY COOL
AIRMASS THERE IS GOOD AGREEMENT AMONG THE MEX, WPC AND MODELED TWO
METER TEMPERATURES. TRENDED SLIGHTLY COOLER THAN WPC GIVEN THE
LATEST 00Z ECMWF WHICH IS ON THE COOLEST END OF THE MODEL GUIDANCE.
LAPSE RATES MAY STEEPEN UP TUESDAY AFTERNOON FOR THE FORMATION OF
SOME CUMULUS AND SPOTTY SHOWERS/THUNDER ON THE BACKSIDE OF THE TROUGH
ACROSS THE NORTH WITH THE AID OF ELEVATION. OTHERWISE BOTH DAYS
LOOK MOSTLY SUNNY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENLY VFR CONDS ARE EXPECTED TODAY. THERE COULD BE SOME LCL MVFR
THIS MRNG IN LOW CLOUDS OR FOG. ADDITIONALLY, THERE COULD BE SOME
SHRA OR ISOLD TSRA, MAINLY S LATER THIS MRNG THRU ERLY EVE WHICH CUD
BRIEFLY DECREASE CIGS/VSBYS. HOWEVER, ODDS ARE LOW ENOUGH TO NOT
MENTION IN THE INDIVIDUAL TAF SITES. WIND IS EXPECTED TO BE NW OR N
AROUND 10 KTS TODAY DECREASING TO LESS THAN 10 KTS TONIGHT.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT: VFR
SATURDAY THROUGH MONDAY: BRIEF MVFR AND IFR RESTRICTIONS IN
SCATTERED THUNDERSTORMS. HIGHEST CHANCE FOR RESTRICTIONS IS ON
SUNDAY AFTERNOON AND EVENING FOR RDG, ABE, TTN, AND POINTS NORTH.
&&
.MARINE...
WITH HIGH PRES BUILDING INTO THE REGION, NO MARINE HEADLINES ARE
ANTICIPATED THRU THE NR AND SHORT TERM PDS.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT: SEAS AND WINDS EXPECTED TO STAY UNDER
SCA CRITERIA. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SATURDAY
AFTERNOON.
SUNDAY AND MONDAY: SEAS INCREASE TO FOUR FEET ON SUNDAY AND PERHAPS
FIVE FEET BY MONDAY MORNING BEFORE FALLING BELOW FIVE FEET MONDAY
NIGHT. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SUNDAY AND MONDAY
AFTERNOONS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...GAINES
AVIATION...GAINES/NIERENBERG
MARINE...GAINES/NIERENBERG
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
405 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONTAL BOUNDARY WILL CONTINUE MOVING OFFSHORE
TODAY. HIGH PRESSURE WILL BUILD ACROSS THE OHIO VALLEY TONIGHT AND
ON FRIDAY. THE HIGH PRESSURE SYSTEM WILL MOVE EAST OF THE REGION ON
SATURDAY AND BE FOLLOWED BY THE PASSAGE OF A WARM FRONT FROM THE
SOUTH BY SATURDAY NIGHT AND BE LOCATED TO OUR NORTH ON SUNDAY.
ANOTHER COLD FRONTAL BOUNDARY THEN WILL SWEEP FROM WEST TO EAST
ACROSS THE REGION ON MONDAY. A HIGH PRESSURE SYSTEM WILL BUILD IN
BEHIND THE COLD FRONT FOR THE MIDDLE HALF OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A CDFNT WAS WORKING ITS WAY ACRS THE REGION AND SHOULD BEE OFFSHORE
LATER THIS MRNG. HIGH PRES WILL SLOWLY BUILD IN BEHIND THE FRONT.
HOWEVER, SOME GUID STILL INDICATES THAT THERE IS ENOUGH INSTABILITY
AND WITH THE FRONT LOCATED JUST TO OUR S, THERE COULD BE SOME
SHOWERS AND SCT TSTMS, MAINLY OVER SRN AREAS FROM LATER THIS MRNG
INTO ERLY EVE. BOTH THE NAM/WRF AND GFS INDICATE AT LEAST SOME
POTENTIAL FOR PRECIP WHILE THE ECMWF IS DRIER. FOR NOW, WILL CARRY
SOME LOW POPS.
THE HRRR ALSO HAS SOME PRECIP MOVG IN FROM THE S AND W THIS AM.
THERE IS SOME LIGHT STUFF OVER PA AND MD, BUT THE HRRR APPEARS A BIT
OVERDONE.
OVERALL GUID TEMPS LOOK REASONABLE AND WERE GENLY FOLLOWED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM FRIDAY/...
HIGH PRES WILL BUILD EWD AND INTO THE AREA TONIGHT. ANY PRECIP WILL
END EARLY AND THE SKY WILL CLEAR. OVERALL, A QUIET NIGHT IS IN
STORE.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FRIDAY AND FRIDAY NIGHT: HIGH PRESSURE GLIDES EAST FROM THE OHIO
VALLEY INTO OUR REGION. VARIABLE WINDS, PLENTY OF SUNSHINE AND NOT
THAT HOT SINCE THIS AIRMASS WILL BE COMING FROM CANADA! LITTLE
SPREAD IN THE MODELS ON MOST IF NOT ALL WEATHER ELEMENTS. TRICKIEST
PART OF THIS PERIOD IS HOW MUCH RADIATIONAL COOLING CAN OCCUR IN
RURAL AREAS BEFORE THE FLOW TURNS MORE SOUTHERLY BY SATURDAY.
OPTED TO GO A TOUCH COOLER THAN MEX/MAV/MET IN A FEW SPOTS WITH
LOWS FRIDAY NIGHT.
SATURDAY AND SATURDAY NIGHT: A WARM FRONT APPROACHES THE REGION FROM
THE SOUTH AND WITH A DEPARTING HIGH PRESSURE THE FLOW TURNS
SOUTHERLY. MODELED MOMENTUM TRANSFER SUGGESTS SOME GUSTS CLOSE TO 20
MPH ARE POSSIBLE IN THE AFTERNOON, WENT HIGHER THAN A STANDARD
125% FOR WIND GUSTS. MID-LEVEL AND SURFACE TEMPERATURES LOOK TO
RESPOND IN KIND, 925 MB TEMPS NEAR 20-22C SHOULD YIELD SURFACE
TEMPERATURES JUST UNDER 90 FOR PHL AND IN THE 80`S ELSEWHERE ACROSS
THE REGION. HUMIDITY IS ON THE RISE BUT THIS WILL BE LIKE MORE
TYPICAL JULY HEAT WITH HEAT INDEX VALUES WELL UNDER ADVISORY LEVELS.
THE WARM FRONT MAY PROVIDE ENOUGH LIFT FOR SOME SCATTERED SHOWERS
AND THUNDERSTORMS FOCUSED ACROSS THE NORTHERN PART OF THE REGION.
THE 21Z SREF AND THE LAST TWO ECMWF RUNS HAVE THESE PINED DOWN WELL.
INCREASING CIN COUPLED WITH 700 MB TEMPS NEAR 10C COULD ALLOW FOR
THE FORMATION OF A WEAK CAP ACROSS THE SOUTHERN PART OF THE REGION,
BEING FURTHER AWAY LOWER CHANCE POPS WERE WARRANTED WHEN COMPARED TO
LOCATIONS FURTHER NORTH.
SUNDAY AND SUNDAY NIGHT: CONTINUED WEST-SOUTHWEST FLOW IN THE WARM
SECTOR. THE LAST FEW GFS RUNS HAVE BEEN MORE AGGRESSIVE WITH
CONVECTION BY THE AFTERNOON AND EVENING HOURS. A COMMON THEME THIS
SUMMER. THINK THE GFS IS TO AGGRESSIVE WITH THIS. HOWEVER, STORM
CHANCES SHOULD INCREASE AS THE MAIN LOW PRESSURE SYSTEM AND COLD
FRONT APPROACH THE REGION. GOOD AGREEMENT AMONG THE GFS ENSEMBLES,
ECMWF ENSEMBLE MEAN AND THE OPERATIONAL MODELS THAT THE HIGHEST
CHANCE WILL BE SUNDAY NIGHT. MAINTAINED LOW END LIKELY POPS ACROSS THE
NORTH AND HIGH END CHANCE ACROSS THE SOUTH. FOR QPF STAYED CLOSE TO
THE SREF AND ECMWF SIMILAR TO SATURDAY. THOUGH DID RAISE IT SLIGHTLY
TO ACCOUNT FOR THE MORE AGGRESSIVE GFS. TEMPERATURES MAY BE RAIN
COOLED SUNDAY BUT DID NOT GO IN THAT DIRECTION ATTM. FAIR SHOT AT 90
FOR PHL WITH SLIGHTLY WARMER MODELED MID-LEVEL TEMPERATURES THAN
SATURDAY.
MONDAY AND MONDAY NIGHT: THE COLD FRONT MOVES THROUGH LIKELY MONDAY
AFTERNOON. HOWEVER THIS SHOULD BE TO LITTLE TO LATE IN TERMS OF
ANOTHER ROUND OF SHOWERS AND STORMS. THE MAIN CAPE AXIS IS LIKELY TO
OFFSHORE AT THIS TIME AND LITTLE IS LEFT FOR A TRIGGER BESIDES THE
ACTUAL FRONTAL BOUNDARY. HOWEVER MAINTAINED LOW CHANCE POPS SINCE THE
FRONT WILL STILL BE IN THE REGION. CLEARED CONDITIONS OUT MONDAY
NIGHT WITH A RETURN TO WESTERLY FLOW. ANOTHER GUSTY DAY AS ONCE
MODELED MOMENTUM TRANSFER SHOWS POTENTIAL FOR SOME GUSTS NEAR 20
MPH.
TUESDAY AND WEDNESDAY: ANOTHER CANADIAN AIRMASS COMES DOWN INTO THE
REGION AS THE SAME GENERAL PATTERN FROM THE WINTERTIME CONTINUES
WITH FEW BREAKS. COOL NORTHWESTERLY FLOW WILL BE IN PLACE AS MOST
LOCATIONS STRUGGLE TO 80 FOR A HIGH. EVEN WITH THIS ABNORMALLY COOL
AIRMASS THERE IS GOOD AGREEMENT AMONG THE MEX, WPC AND MODELED TWO
METER TEMPERATURES. TRENDED SLIGHTLY COOLER THAN WPC GIVEN THE
LATEST 00Z ECMWF WHICH IS ON THE COOLEST END OF THE MODEL GUIDANCE.
LAPSE RATES MAY STEEPEN UP TUESDAY AFTERNOON FOR THE FORMATION OF
SOME CUMULUS AND SPOTTY SHOWERS/THUNDER ON THE BACKSIDE OF THE TROUGH
ACROSS THE NORTH WITH THE AID OF ELEVATION. OTHERWISE BOTH DAYS
LOOK MOSTLY SUNNY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
GENLY VFR CONDS ARE EXPECTED TODAY. THERE COULD BE SOME LCL MVFR
THIS MRNG IN LOW CLOUDS OR FOG. ADDITIONALLY, THERE COULD BE SOME
SHRA OR ISOLD TSRA, MAINLY S LATER THIS MRNG THRU ERLY EVE WHICH CUD
BRIEFLY DECREASE CIGS/VSBYS. HOWEVER, ODDS ARE LOW ENOUGH TO NOT
MENTION IN THE INDIVIDUAL TAF SITES. WIND IS EXPECTED TO BE NW OR N
AROUND 10 KTS TODAY DECREASING TO LESS THAN 10 KTS TONIGHT.
OUTLOOK...
FRIDAY AND FRIDAY NIGHT: VFR
SATURDAY THROUGH MONDAY: BRIEF MVFR AND IFR RESTRICTIONS IN
SCATTERED THUNDERSTORMS. HIGHEST CHANCE FOR RESTRICTIONS IS ON
SUNDAY AFTERNOON AND EVENING FOR RDG, ABE, TTN, AND POINTS NORTH.
&&
.MARINE...
WITH HIGH PRES BUILDING INTO THE REGION, NO MARINE HEADLINES ARE
ANTICIPATED THRU THE NR AND SHORT TERM PDS.
OUTLOOK...
FRIDAY THROUGH SATURDAY NIGHT: SEAS AND WINDS EXPECTED TO STAY UNDER
SCA CRITERIA. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SATURDAY
AFTERNOON.
SUNDAY AND MONDAY: SEAS INCREASE TO FOUR FEET ON SUNDAY AND PERHAPS
FIVE FEET BY MONDAY MORNING BEFORE FALLING BELOW FIVE FEET MONDAY
NIGHT. A FEW WIND GUSTS AROUND 20 KNOTS POSSIBLE SUNDAY AND MONDAY
AFTERNOONS.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...GAINES
NEAR TERM...NIERENBERG
SHORT TERM...NIERENBERG
LONG TERM...GAINES
AVIATION...GAINES/NIERENBERG
MARINE...GAINES/NIERENBERG
AREA FORECAST DISCUSSION
NWS TOPEKA KS
349 AM CDT Thu Jul 24 2014
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 06Z TAFs through 06Z Thursday Night)
Issued at 1147 PM CDT WED JUL 23 2014
Expect VFR conditions. Any isolated thunderstorms during morning
hours will remain north of the terminals. Winds will become
southeast at 8 to 12 KTS with higher gusts after 14Z and continue
through the afternoon and evening.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Gargan
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
540 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE ODD THUNDERSTORM WILL CONTINUE TO DIMINISH
FOR THE BULK OF THE FORECAST AREA THROUGH THE NIGHT. HOWEVER...A
COUPLE OF CELLS WILL STILL BE POSSIBLE INTO DAWN...BUT PROBABLY KEEP
FROM HITTING ANY OF THE ACTUAL TAF SITES. FOR THE MOST PART...
CONDITIONS WILL BE MVFR AT ALL THE AIRPORTS TONIGHT WITH TIMES OF VFR
BUT ALSO LOW VIS/CIG INDUCED IFR WX...OR LOWER. HAVE KEPT THUNDER AND
EVEN VCTS OUT OF THE TAFS AS THE INSTABILITY WILL BE MINIMAL
THROUGH THE REST OF THE NIGHT INTO THURSDAY. HOWEVER...THE LATEST
HRRR AND NAM12 SUGGEST THAT A FEW SHOWERS WILL STILL BE POSSIBLE INTO
THE AFTERNOON AS THE FRONT MAKES ITS FINAL PUSH ACROSS THE AREA.
HAVE CONTINUED A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND
2K FEET. IN THE WAKE OF THE FRONT LATER THURSDAY EVENING...DRIER AIR
IS EXPECTED TO LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS
THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH
FAVORING THE NORTHERLY DIRECTION LATER THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
350 AM EDT THU JUL 24 2014
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 155 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE ODD THUNDERSTORM WILL CONTINUE TO DIMINISH
FOR THE BULK OF THE FORECAST AREA THROUGH THE NIGHT. HOWEVER...A
COUPLE OF CELLS WILL STILL BE POSSIBLE INTO DAWN...BUT PROBABLY KEEP
FROM HITTING ANY OF THE ACTUAL TAF SITES. FOR THE MOST PART...
CONDITIONS WILL BE MVFR AT ALL THE AIRPORTS TONIGHT WITH TIMES OF VFR
BUT ALSO LOW VIS/CIG INDUCED IFR WX...OR LOWER. HAVE KEPT THUNDER AND
EVEN VCTS OUT OF THE TAFS AS THE INSTABILITY WILL BE MINIMAL
THROUGH THE REST OF THE NIGHT INTO THURSDAY. HOWEVER...THE LATEST
HRRR AND NAM12 SUGGEST THAT A FEW SHOWERS WILL STILL BE POSSIBLE INTO
THE AFTERNOON AS THE FRONT MAKES ITS FINAL PUSH ACROSS THE AREA.
HAVE CONTINUED A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND
2K FEET. IN THE WAKE OF THE FRONT LATER THURSDAY EVENING...DRIER AIR
IS EXPECTED TO LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS
THROUGH THE PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH
FAVORING THE NORTHERLY DIRECTION LATER THURSDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
427 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
408 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATE TONIGHT AND THURSDAY...
THEN DISSIPATES ACROSS THE CAROLINAS FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE MOVES NORTH OF THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
402 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATE TONIGHT AND THURSDAY...
THEN DISSIPATES ACROSS THE CAROLINAS FRIDAY THROUGH SATURDAY AS
HIGH PRESSURE MOVES NORTH OF THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING FROM
NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
SUB-SCA CONDITIONS EXPECTED THROUGH THE NEXT FEW DAYS WITH SFC HI
PRES LOCATED WELL OFFSHORE AND A FAIRLY WEAK PRES GRADIENT OVR THE
MID ATLANTIC. AHEAD OF A PREFRNTAL TROF OVR THE PIEDMONT THIS
AFTN/EVENG...SLY WINDS OVR THE BAY WILL RISE TO 10-15 KT...JUST BLO
SCA THRESHOLDS. SEAS WILL BLD TO 3-4 FT FOR NRN CSTL WTRS. A COLD
FRNT CROSSES THE WTRS ON THU...WITH WINDS SHIFTING FM SW TO NW...AND
STAYING SUB-SCA BEHIND THE FRNT DUE TO VERY WEAK CAA. BENIGN MARINE
CONDITIONS CONTINUE INTO FRI AND SAT AS SFC HI PRES BLDS INTO THE
REGION. WINDS WILL STAY AOB 10 KT WITH 1-2 FT WAVES OVR THE BAY AND
2-3 FT OVR CSTL WTRS. NEXT COLD FRNT CROSSES THE WTRS LATE MON/MON
NGT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...MAS
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
354 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1141 PM CDT WED JUL 23 2014
FEW PROBLEMS EXPECTED IN THE NEAR TERM AS HIGH PRESSURE MAINTAINS
CONTROL OF THE WEATHER ACROSS THE UPPER MIDWEST THROUGH THE
MORNING HOURS. THE ONLY ISSUE MAY BE FOG DEVELOPMENT IN THE PRONE
AREAS ESPECIALLY TO THE EAST WHERE WINDS WILL BE LIGHTER TOWARD
DAYBREAK. OTHERWISE...SHOWERS WILL BE APPROACHING WESTERN
MINNESOTA IN THE MORNING AFTER A STRONG LLJ DEVELOPS OVERNIGHT
ACROSS THE DAKOTAS. STILL EXPECT THESE SHOWERS TO BE DIMINISHING
SO NOT CONFIDENT IN ACTUALLY SEEING RAIN AT A SPECIFIC LOCATION
SUCH AS RWF...SO REMOVED THE CHANCE THERE. THEN...A MORE ROBUST
CHANCE OF PRECIPITATION COMES LATE THURSDAY NIGHT WHICH IS
INDICATED AT MSP AND RWF. MSP MAINLY BECAUSE OF THE EXTRA 6 HOUR
WINDOW. LIGHT WINDS TONIGHT WILL CONTINUE TURNING EAST AND NEARLY
SOUTH THROUGH TOMORROW.
KMSP...MAIN FOCUS WILL BE THE THUNDERSTORMS EXPECTED IN THE
OVERNIGHT PERIOD THURSDAY INTO FRIDAY. OTHERWISE VFR CONDITIONS
EXPECTED WITH LITTLE CHANGES FROM THE PREVIOUS FORECAST.
/OUTLOOK FOR KMSP/
THU NIGHT...VFR. CHANCE MVFR CONDS W/ TSRA OVERNIGHT. WINDS SE AT
10KTS.
FRI...VFR. CHANCE TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS W AT 10KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...SPD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
338 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 335 AM THURSDAY...
THE MEDIUM RANGE WILL BE CHARACTERIZED BY THE DEVELOPMENT OF ANOTHER
UNSEASONABLY HIGH AMPLITUDE TROUGH ALOFT FROM SOUTHEASTERN CANADA
INTO THE EASTERN US...WITH AN ASSOCIATED NEGATIVE HEIGHT OF NEARLY 3
STANDARD DEVIATIONS BELOW AVERAGE FROM THE LOWER GREAT LAKES/OHIO
VALLEY TO THE CENTRAL APPALACHIANS. PRECIPITATION CHANCES DURING THE
PERIOD WILL BE HIGHEST SUN NIGHT-MON...AS THE TROUGH AMPLIFIES
SOUTHEASTWARD AND SPREADS THE ASSOCIATED MID LEVEL HEIGHT FALLS AND
UNDERLYING LO LEVEL FRONTAL ZONE ACROSS NC.
IN FACT...THE DAY SUNDAY SHOULD BE MAINLY DRY...AND HOT AS THE MID
LEVEL RIDGE OVER THE DESERT SW AND PLAINS BUILDS BRIEFLY EAST IN
ADVANCE OF THE AMPLIFYING TROUGH ALOFT. H85 TEMPERATURES ARE
FORECAST TO SURGE...ALBEIT BRIEFLY...INTO THE 22-24 DEGREE RANGE
OVER THE CAROLINAS...SUPPORTIVE OF HIGH TEMPERATURES SOLIDLY IN THE
MIDDLE 90S. UPSTREAM PRE-FRONTAL CONVECTION AND ASSOCIATED OUTFLOW
WILL THEN LIKELY DRIFT...IN A GRADUALLY WEAKENING STATE OWING TO
NOCTURNAL COOLING...INTO THE NORTHERN AND WESTERN PIEDMONT DURING
THE EVENING AND EARLY NIGHTTIME HOURS.
THE PATTERN ON THE SYNOPTIC SCALE...CHARACTERIZED BY THE APPROACHING
STRONG TROUGH AND DOWNSTREAM JET ENTRANCE DIVERGENCE ALOFT...AND LOW
LEVEL FRONTAL FORCING...FAVORS CONSIDERABLE THUNDERSTORM COVERAGE
MON...INCLUDING SOME SEVERE OWING TO UNSEASONABLY STRONG MID LEVEL
FLOW ON THE ORDER OF 40-50 KTS. HOWEVER...PREDICTABILITY ASSOCIATED
WITH MESOSCALE INFLUENCES (IE. OUTFLOW AND CLOUD COVER) FROM EARLIER
CONVECTION SUN NIGHT COMPLICATE THE FORECAST SO PROBABILITY OF
PRECIPITATION WILL BE KEPT IN THE HIGH CHANCE RANGE FOR NOW...WITH
THE EXPECTATION THAT THESE PROBABILITIES WILL BE INCREASED OVER AT
LEAST A PORTION OF THE FORECAST AREA (LIKELY THE SOUTHEAST HALF).
THE MIDDLE OF THE WEEK SHOULD BE DRY...AND COOLER...AS POST-FRONTAL
HIGH PRESSURE BUILDS INTO THE CENTRAL APPALACHIANS...AND
PRECIPITABLE WATER VALUES FALL BELOW AN INCH OVER CENTRAL NC. HIGHS
AND LOWS ONLY IN THE LOWER TO MIDDLE 80S AND LOWER TO MIDDLE
60S...RESPECTIVELY...TUE-WED.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
324 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FRI-FRI NIGHT TO BE UPDATED...
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MWS
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH WILL GREATLY CUT
DOWN ON OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA.
THE LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM / /...
AS OF 315 PM WEDNESDAY...
TO BE UPDATED.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 235 PM WEDNESDAY...
NWP GUIDANCE IS RELATIVELY CONSISTENT IN BRINGING THE SURFACE COLD
FRONT TO THE COASTAL PLAIN OF THE CAROLINAS BY 12 UTC FRIDAY AS THE
UPPER LEVEL TROUGH AXIS CROSSES THE APPALACHIANS. THE UPPER LEVEL
TROUGH AXIS MAKES LIMITED PROGRESS EAST ON FRIDAY AS THE NEXT
SHORTWAVE TROUGH OVER THE OH VALLEY EARLY FRIDAY SPLITS WITH ONE
PIECE OF ENERGY MOVING EAST INTO THE NORTHEAST AND THE OTHER DROPS
TOWARD THE SAVANNAH RIVER VALLEY. THE FRONT DRIFTS SOUTH AND BRIEFLY
STALLS BEFORE MOVING NORTH INTO THE MID ATLANTIC AS A WARM FRONT
SATURDAY. DEEP MOISTURE DECREASES ON FRIDAY COMPARED TO THURSDAY
WITH THE BULK OF THE MOISTURE CONFINED TO THE 925 TO 700 MB LAYER IN
A REGION OF RELATIVELY STEEP LAPSE RATES. THIS PATTERN SUGGESTS THE
BEST CONVECTIVE COVERAGE ON FRIDAY WILL BE ACROSS THE FAR SOUTHEAST
PIEDMONT AND ESPECIALLY THE COASTAL PLAIN AND EASTERN SANDHILLS
FRIDAY AFTERNOON AND EVENING. POPS IN THE SLIGHT CHANCE TO LOW
CHANCE RANGE SHOULD SUFFICE. HIGHS ON FRIDAY WILL RANGE IN THE MID
TO UPPER 80S. PARTLY CLOUDY SKIES ARE EXPECTED FRIDAY NIGHT WITH
LOWS IN THE MID 60S TO NEAR 70. SATURDAY WILL FEATURE PARTLY CLOUDY
SKIES WITH THE BULK OF THE CONVECTION SUPPRESSED TOWARD THE COAST.
THERE IS JUST A LIMITED THREAT OF PRECIPITATION IN CENTRAL NC WITH
THE BEST CHANCE OF STORMS ON SATURDAY ACROSS THE EASTERN COASTAL
PLAIN WITH ONLY SLIGHT CHANCE POPS WARRANTED. SATURDAY SHOULD
FEATURE THE FAIRER WEATHER OF THE WEEKEND WITH VERY LIMITED
PRECIPITATION COVERAGE AND NEAR SEASONABLE TEMPERATURES.
TEMPERATURES WILL MODERATE A BIT ON SATURDAY WITH HIGHS IN THE 87 TO
92 RANGE.
THE NEXT UPPER TROUGH APPROACHES FROM THE NORTHWEST ON SUNDAY WITH A
COLD FRONT DROPPING ACROSS THE OH VALLEY. A LEE TROUGH AHEAD OF THE
FRONT ACROSS THE PIEDMONT OF VA AND THE CAROLINAS IS EXPECTED TO
BECOME CONVECTIVELY ACTIVE DURING THE AFTERNOON AND EVENING WITH
SCATTERED CONVECTION. THE SOUTHERLY FLOW AHEAD OF THE UPPER
TROUGH... COMBINED WITH DEEP MIXING WILL RESULT IN HIGHS IN THE
LOWER 90S. THE UPPER TROUGH AXIS AND COLD FRONT WILL CROSS CENTRAL
NC ON MONDAY WITH GOOD CONVECTIVE COVERAGE ANTICIPATED. WILL
INCREASE POPS INTO THE HIGH CHANCE RANGE. WITH THE APPROACHING
TROUGH...THE LOW AND MID LEVEL FLOW INCREASES WITH BULK SHEAR VALUES
OF 30-40 KTS EXPECTED SUGGESTING SOME HIGH-BASED STORM ORGANIZATION
IS POSSIBLE. SLIGHTLY COOLER TEMPERATURES ARE EXPECTED ON MONDAY
WITH THE CLOUD COVER AND PRECIPITATION...HIGHS SHOULD RANGE IN THE
86 TO 91 RANGE WITH LOWS MONDAY MORNING IN THE 69 TO 74 RANGE.
THE LARGE AMPLITUDE UPPER LEVEL TROUGH SLOWLY MOVES EAST ON TUESDAY
WITH THE COLD FRONT PROGGED TO MOVE INTO THE COASTAL PLAIN MONDAY
NIGHT AND SLOWLY PUSH TOWARD THE COAST ON TUESDAY. COOL HIGH
PRESSURE BUILDS INTO THE REGION WITH ANY PRECIPITATION ON TUESDAY
LIKELY CONFINED TO THE COASTAL PLAIN AND POINTS EAST. MAINLY DRY
CONDITIONS ARE EXPECTED ON WEDNESDAY BUT IT IS WORTH NOTING THAT THE
GFS/ECMWF BOTH INDICATE THE STALLED FRONT NEAR THE COAST MAY TRY TO
WORK WEST. FOR NOW WILL INCLUDE A DRY FORECAST. THE MUCH COOLER AIR
MASS WITH LOW LEVEL THICKNESS VALUES FALLING INTO THE 1375-1390M
RANGE FOR TUESDAY AND WEDNESDAY MORNINGS. THIS WOULD SUPPORT LOWS IN
THE 60S AND PERHAPS UPPER 50S IN THE TRIAD OR NEAR THE VA BORDER ON
WEDNESDAY MORNING WITH HIGHS OF 79-86. -BLAES
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 130 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE THROUGH DAYBREAK AT ALL TAF
SITES. A LIGHT BUT STEADY SURFACE BREEZE FROM THE SW WILL KEEP THE
LOW LEVELS STIRRED AND INHIBIT MOST FOG DEVELOPMENT... BUT A SHORT
PREDAWN PERIOD (UNDER 2 HRS) OF MVFR FOG IS NOT OUT OF THE QUESTION.
CURRENTLY ANY CLOUD COVER OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS
BASED ABOVE 10 000 FT AGL MAINLY IN THE NW... AND WHILE CIGS WILL BE
DROPPING AHEAD OF THE COLD FRONT APPROACHING FROM THE NW... THEY
SHOULD STAY VFR THROUGH 13Z. SCATTERED TO NUMEROUS SHOWERS AND
STORMS ARE EXPECTED NEAR INT/GSO STARTING AROUND 13Z OR 14Z... AND
THESE COULD GENERATE MVFR CIGS/VSBYS AND ENHANCED WIND GUSTS. THESE
SHOWERS/STORMS ARE THEN EXPECTED TO AFFECT RDU AND RWI STARTING
AROUND 14Z OR 15Z... AND FAY STARTING AT 17Z OR 18Z. TOUGH CALL ON
WHEN THE STORM THREAT WILL EXIT TAF SITES... BUT VFR CONDITIONS
SHOULD RETURN SOON AFTER 22Z AT GSO... 00Z AT RDU/RWI... AND
PROBABLY NOT UNTIL AFTER 04Z AT FAY.
LOOKING BEYOND 06Z EARLY FRI MORNING... SURFACE WINDS WILL REMAIN
FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND QUICKLY FROM WSW TO NNE
AS THE FRONT PUSHES SOUTHEAST THROUGH NC. THE FRONT WILL LIKELY SLOW
DOWN ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT
FAY THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE
EXPECTED FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS
FRONT WILL SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A
SURFACE TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE
AND ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON
SUNDAY... POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE
SUNDAY INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...MLM
LONG TERM...BLAES
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
124 AM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 104 AM CDT THU JUL 24 2014
HAVE UPDATED TO REFINE POPS.
UPDATE ISSUED AT 925 PM CDT WED JUL 23 2014
WHILE CONVECTION HAS REMAINED LOW IN COVERAGE THROUGH 230 UTC
ACROSS CENTRAL AND EASTERN MONTANA INTO SOUTHWEST
SASKATCHEWAN...IT HAS INCREASED IN INTENSITY OVER THE PAST HOUR.
SPC HAS JUST ISSUED A SEVERE THUNDERSTORM WATCH ACROSS NORTH
CENTRAL MONTANA. SEE SPC MCD 1452 FOR DETAILS REGARDING TRENDS
THROUGH 345 UTC AS STORMS PROPAGATE EAST. ALL MODEL GUIDANCE HAS
HAD A TOUGH TIME HANDLING THE CONVECTIVE SCENARIO THIS
EVENING...WITH STORMS NOW EXPECTED TO APPROACH THE NORTH DAKOTA
BORDER AROUND 07-09 UTC.
UPDATE ISSUED AT 539 PM CDT WED JUL 23 2014
NO SIGNIFICANT CHANGES WITH THIS FORECAST UPDATE. STILL MONITORING
FOR CONVECTIVE INITIATION ACROSS CENTRAL INTO EASTERN MONTANA OVER
THE NEXT ONE TO TWO HOURS. THE 20 UTC HRRR WOULD SUGGEST
MONTANA SURFACE BASED CONVECTION APPROACHING THE NORTH DAKOTA BORDER
BY 03-04 UTC...CONTINUING TO PROPAGATE INTO CENTRAL NORTH DAKOTA
BY 08-09 UTC SUSTAINED BY A 30-35 KT LOW LEVEL JET. THE BEST
CHANCE FOR LARGE HAIL AND DAMAGING WINDS ARE GENERALLY ALONG AND
WEST OF HIGHWAY 85 AS THE MONTANA CONVECTION PROPAGATES INTO
WESTERN NORTH DAKOTA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
FORECAST ISSUES IN THE SHORT TERM ARE THUNDERSTORM CHANCES...AND
POSSIBILITY OF SEVERE STORMS.
CURRENTLY...SURFACE HIGH WAS OVER MANITOBA SOUTHWARD THROUGH THE RED
RIVER VALLEY...WITH LOW PRESSURE IN THE LEE OF THE ROCKIES.
SOUTHEASTERLY FLOW WAS KEEPING MOIST LOW LEVELS WITH DEWPOINTS IN
THE 60S OVER WESTERN AND CENTRAL NORTH DAKOTA. AT UPPER LEVELS...A
SHARP RIDGE WAS IN PLACE FROM SASKATCHEWAN TO THE WESTERN DAKOTAS
AND EASTERN MT/WY. BEST SHEAR AND MID LEVEL LAPSE RATES WERE OVER
THE FRONT RANGE THIS AFTERNOON...WITH MOST UNSTABLE CAPES OVER THE
FRONT RANGE INTO THE WESTERN DAKOTAS.
LATEST MODEL RUNS SUGGEST THUNDERSTORMS DEVELOPING OVER CENTRAL AND
EASTERN MONTANA THIS EVENING IN THE VICINITY OF A MID LEVEL
SHORTWAVE ENERGY IMPULSE FORECAST TO MOVE/DEVELOP INTO NORTHEASTERN
MONTANA DURING THE EVENING. ONCE CONVECTION BECOMES BETTER
ESTABLISHED...THE SCENARIO IS FOR STORMS TO MIGRATE EASTWARD INTO
WESTERN NORTH DAKOTA LATER THIS EVENING...THEN SPREAD INTO CENTRAL
NORTH DAKOTA AFTER MIDNIGHT. THE WESTERN THIRD OF NORTH DAKOTA HAS
THE BEST POTENTIAL FOR SEVERE STORMS LATE THIS EVENING INTO THE
EARLY MORNING HOURS.
ONGOING CONVECTION DAYBREAK THURSDAY OVER MUCH OF CENTRAL NORTH
DAKOTA EXPECTED TO CONTINUE MOVING EASTWARD. THEN...ATTENTION TURNS
TO THE WEST AS A SIGNIFICANT UPPER LOW EMERGES INTO THE FRONT RANGE
FROM THE ROCKIES WITH STRONG SOUTHWEST FLOW ALOFT INTO THE DAKOTAS.
AT THE SAME TIME...THE AFOREMENTIONED SURFACE LOW OVER THE FRONT
RANGE WILL HAVE MOVED/DEVELOPED EASTWARD INTO THE WESTERN DAKOTAS.
THESE INGREDIENTS WILL BE FAVORABLE FOR PLENTY OF SHEAR...CAPE
(ESPECIALLY WITH SURFACE DEWPOINTS IN THE 65 TO 70 DEGREE
RANGE)...AND UPPER LEVEL IMPULSES. GOOD CHANCE OF THUNDERSTORMS
THURSDAY AFTERNOON OVER THE WESTERN THIRD OF THE STATE. THIS WILL
CONTINUE INTO THE EVENING HOURS AS WELL...WITH SEVERE WEATHER
POSSIBLE OVER MUCH OF THE FORECAST AREA THURSDAY AFTERNOON/NIGHT.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 320 PM CDT WED JUL 23 2014
THE MAIN FEATURES IN THE LONG TERM PERIOD CONTINUE TO BE AN UPPER
LOW OFF THE WA/OR COAST AND ITS INTERACTION WITH THE DOWNSTREAM
H500 RIDGE OVER THE NORTHERN PLAINS. AS THE UPPER LOW MOVES EAST
AND FLATTENS THE RIDGE...A COLD FRONT AT THE SURFACE WILL
POSITION ITSELF ACROSS EASTERN MONTANA BY THURSDAY AFTERNOON. THE
FRONT WILL THEN PUSH EAST ACROSS NORTH DAKOTA THURSDAY
EVENING AND OVERNIGHT INTO FRIDAY MORNING. THUNDERSTORMS...A FEW
POSSIBLY SEVERE WITH STRONG WINDS AND HAIL THE MAIN THREATS WILL
ACCOMPANY THE FRONT AS IT PROGRESSES EAST THROUGH THE STATE
THURSDAY AFTERNOON AND EVENING. ON FRIDAY COOLER BUT STILL
REASONABLY MILD TEMPERATURES IN THE UPPER 70S TO LOWER 80S SHOULD
BE THE RULE. ANY SHOWERS AND ISOLATED THUNDERSTORMS SHOULD BE
LIMITED TO THE EAST. ONE MORE DAY OF SHOWERS/SCATTERED
THUNDERSTORMS ON SATURDAY AS THE SLOW MOVING UPPER LOW TRACKS
SOUTH ACROSS MINNESOTA. WHILE THE STATE WILL GENERALLY BE ON THE
DRY SIDE OF THE UPPER LOW CANT RULE OUT SHOWERS AS COOL AIR ALOFT
SHOULD SUPPORT SOME INSTABILITY...ESPECIALLY NORTH. AS THE UPPER
LOW DRIFTS EAST AND A RIDGE POPS UP IN MONTANA SUNDAY THROUGH
TUESDAY...SHOULD BE DRY WITH GENERALLY PLEASANT TEMPERATURES AND
HUMIDITY FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 104 AM CDT THU JUL 24 2014
VFR CONDITIONS OUTSIDE OF THUNDERSTORMS ARE FORECAST FOR THE 06UTC
TAF CYCLE ACROSS WESTERN AND CENTRAL NORTH DAKOTA. ISOLATED
THUNDERSTORMS IN NORTHEAST MONTANA WERE MOVING INTO NORTHWEST
NORTH DAKOTA AND WILL SPREAD EAST AND SOUTH THROUGH 12UTC. SEE
TAFS FOR TIMING AND THREAT DETAILS. ANOTHER ROUND OF STORMS IS
EXPECTED LATE THURSDAY AFTERNOON AND INTO THE EVENING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...JPM
SHORT TERM...JV
LONG TERM...NH
AVIATION...JPM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
523 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 520 AM...LATEST WATER VAPOR IMAGES INDICATED THAT THE MID
LEVEL TROF WAS LOCATED GENERALLY OVER THE TN/NC LINE...WITH A S/W
OVER THE PIEDMONT. KGSP AND TCLT RADAR INDICATED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH EACH FEATURE. I WILL UPDATE THE
FORECAST TO INCREASE POPS ALONG AND EAST OF THE OBSERVED CONVECTION.
OTHERWISE...THE CURRENT FORECAST APPEARS IN GREAT SHAPE.
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS THIS MORNING WILL REMAIN LESS FAVORABLE FOR FOG
AND CIG RESTRICTIONS THAN PREVIOUS MORNINGS. I WILL FORECAST VFR
CONDITIONS TO REMAIN THROUGH THE REST OF THIS MORNING...WITH VERY
LIGHT TO CALM WINDS. THE PRIMARY FORECAST CHALLENGE WILL BE THE
TIMING OF AFTERNOON TSRA. THE 4KM WRF INDICATES THAT CONVECTION WILL
DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A BAND.
STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE BAND TO
MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING ACROSS THE
CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE TSRA
POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z.
ELSEWHERE...TERMINALS EAST OF THE MTNS WILL REMAIN SIMILAR TO CLT.
KAVL WILL LIKELY SEE IFR OR LOWER CONDITIONS DURING THE PRE DAWN
HOURS...RETURNING TO VFR BY 13Z. KAVL SHOULD SEE WINDS FROM THE 330
TO 350 DEGREES THROUGH THE TAF PERIOD.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
09-15Z 15-21Z 21-03Z 03-09Z
KCLT HIGH 99% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL LOW 58% HIGH 100% HIGH 100% MED 64%
KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 97% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
347 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
AT KCLT...CONDITIONS THIS MORNING WILL REMAIN LESS FAVORABLE FOR FOG
AND CIG RESTRICTIONS THAN PREVIOUS MORNINGS. I WILL FORECAST VFR
CONDITIONS TO REMAIN THROUGH THE REST OF THIS MORNING...WITH VERY
LIGHT TO CALM WINDS. THE PRIMARY FORECAST CHALLENGE WILL BE THE
TIMING OF AFTERNOON TSRA. THE 4KM WRF INDICATES THAT CONVECTION WILL
DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A BAND.
STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE BAND TO
MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING ACROSS THE
CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE TSRA
POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z.
ELSEWHERE...TERMINALS EAST OF THE MTNS WILL REMAIN SIMILAR TO CLT.
KAVL WILL LIKELY SEE IFR OR LOWER CONDITIONS DURING THE PRE DAWN
HOURS...RETURNING TO VFR BY 13Z. KAVL SHOULD SEE WINDS FROM THE 330
TO 350 DEGREES THROUGH THE TAF PERIOD.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
07-13Z 13-19Z 19-01Z 01-07Z
KCLT HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 67% HIGH 88% HIGH 100% HIGH 80%
KHKY HIGH 100% HIGH 95% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
423 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1055 PM CDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECETD THROUGH THE TAF PERIOD. SCATTERED
THUNDERSTORMS ARE EXPECTED TO MOVE INTO SOUTH CENTRAL SD LATE TONIGHT
AND SLOWLY TRACK EASTWARD ACROSS THE AREA THROUGH THE DAY THURSDAY.
EXPECT ACTIVITY IN THE KHON AREA FROM 09Z TO 14Z AND INTO THE I29
CORRIDOR...INCLUDING FSD AND SUX AFTER 13Z. AGAIN...COVERAGE WILL BE
SCATTERED HOWEVER DID LEAVE TEMPO MENTION AT ALL 3 TAF SITES. THE
HIGH BASED STORMS WILL LIKELY KEEP CONDITIONS PREDOMINATELY IN
VFR...BUT STRONGER GUSTS AND VERY BRIEF MVFR CONDITIONS WILL BE
POSSIBLE IN THE STRONGER STORMS. BREEZY SOUTH SOUTHEAST WINDS PICK UP
AFTER 12Z AND PERIST THROUGH THE END OF THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1103 PM CDT WED JUL 23 2014
.UPDATE...
ISSUED AT 950 PM CDT WED JUL 23 2014
FORECAST FOR TONIGHT STILL LOOKS IN PRETTY GOOD SHAPE. THETAE
ADVECTION STILL PROGGED TO INCREASE TONIGHT...WITH THE COMBINATION OF
THIS INCREASING MOISTURE AND STEEPENING LAPSE RATES ALOFT RESULTING IN
INCREASING INSTABILITY. BASED ON SOUNDINGS...APPEARS LIKE CONVECTION
SHOULD BE BASED AROUND 700 MB. AS BY LATER TONIGHT...PARCELS FROM
THIS LAYER SHOULD BE UNCAPPED...AND REALIZE BETWEEN 1000 AND 1500
J/KG OF CAPE. THESE STORMS SHOULD BE BASED ABOVE THE BEST
SHEAR...HOWEVER RAP SOUNDINGS STILL SUGGEST THEY MAY BE ABLE TO TAP
INTO 30 TO 40 KTS OF EFFECTIVE SHEAR. THUS STILL SEEMS LIKE SMALL
HAIL WOULD BE A POSSIBILITY WITH ANY STORM...WITH A FEW OF THE
STRONGER ONES POSSIBLY PUSHING QUARTERS. LEANING TOWARDS THE
HRRR...RAP AND ECMWF FOR TIMING...BRINGING STORMS INTO THE WEST
AROUND 08Z TO 09Z...APPROACHING INTERSTATE 29 BY 12Z. DO THINK STORMS
WILL BE IN A WEAKINING STATE AS THEY APPROACH INTERSTATE 29 AND POINTS
EAST AS THE LOW LEVEL JET SLACKENS WITH DAYBREAK. THE 0Z NAM SEEMS
OFF AND AN OUTLIER SO WAS DISCOUNTED AT THIS TIME. NOT A SURE BET WE
SEE CONVECTION OVERNIGHT...AS THESE ELEVATED EVENTS ARE ALWAYS
TRICKY...SO WILL STAY BELOW LIKELY POPS...BUT AM DEFINITELY LEANING
TOWARDS US AT LEAST SEEING SCATTERED ACTIVITY.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 317 PM CDT WED JUL 23 2014
MAIN FOCUS OF THE SHORT RANGE FORECAST WILL BE LATE TONIGHT AND
THURSDAY MORNING. DEALING WITH A LOT OF THETAE WARM AIR ADVECTION
MOVING INTO...THEN ACROSS OUR FORECAST AREA...FIRST HITTING OUR FAR
WESTERN ZONES OVERNIGHT TONIGHT...THEN EXITING OUR EAST THURSDAY
AFTERNOON. THE THETAE ADVECTION IS MAXIMIZED IN THE 800-750MB LAYER
AT THE TOP OF THE INVERSION. THE INVERSION IS STRONG IN THE LOW
LEVELS...THEREFORE IT IS LIKELY THAT THE STRONG DIRECTIONAL WIND
SHEAR IN THE LOWEST 1.5KM WILL NOT BE TAPPED...LEAVING ELEVATED
SHOWERS OR STORMS WHICH WILL BE TOUGH TO HIT SEVERE CRITERIA LATE
TONIGHT AND EARLY THURSDAY WEST OF I 29. AS FAR AS POPS...STILL DID
NOT HAVE ENOUGH EVIDENCE TO GO LIKELY POPS AT ANY PARTICULAR
LOCATION FROM 06Z TO 18Z THURSDAY. THE VARIOUS HIRES MODELS ARE
SURPRISINGLY DRY...POSSIBLY DUE TO THE AFOREMENTIONED REASON OF THE
PRECIP BEING ELEVATED. THEREFORE ONLY THE GLOBAL MODELS ARE BULLISH
IN DEVELOPING CONVECTION RIGHT TO THE WEST OF THE MID LEVEL RIDGE
AXIS...WHICH DOES NOT LEAD TO A LOT OF CONFIDENCE IS GOING LIKELY OR
CATEGORICAL POPS YET. WILL JUST HAVE TO MONITOR HOW THIS MORPHS
OUT. AS THE PRECIP TRIES TO MOVE EASTWARD BY MIDDAY THURSDAY...LESS
MID LEVEL MOISTURE LOOKS TO BE AVAILABLE IN OUR EASTERN ZONES BY
THURSDAY AFTERNOON WITH WEAKER THETAE ADVECTION.
TEMPERATURES STILL LOOK PLEASANT TONIGHT. HOWEVER 850MB TEMPERATURES
ARE VERY WARM WEST OF THE JAMES RIVER VALLEY ON THURSDAY BEHIND THE
THETAE ADVECTION. THEREFORE AS SKIES CLEAR IN THE EVENING...STILL
LOOKING AT LOWER 90S APPROACHING CENTRAL SD...WITH A DRAMATIC DROP
OFF IN TEMPERATURES HEADING EAST OF THE THERE. IN FACT EAST OF THE
JAMES...WE ARE STILL LOOKING AT READINGS ONLY A COUPLE OF DEGREES
EITHER SIDE OF 80 AS THE COOL HIGH PRESSURE SYSTEM OVER THE GREAT
LAKES STILL GREATLY INFLUENCES THE WEATHER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 317 PM CDT WED JUL 23 2014
A RIDGE FLATTENING SHORT WAVE MAY BRING SOME REDEVELOPMENT OF
STORMS THURSDAY NIGHT...ISOLATED WEST AND SCATTERED EAST...MAINLY
FAR EAST WHERE MOST MOISTURE AND INSTABILITY WILL LINGER.
HOWEVER...THIS MOISTURE AND INSTABILITY WILL BE LIMITED AND MOST
OF THE ACTIVITY SHOULD END LATE. ISOLATED STORMS STILL SEEM
POSSIBLE FAR EAST FRIDAY WITH SOME WEAK UPPER AND THERMAL SUPPORT
ASSOCIATED WITH THE LINGERING MOISTURE. ANOTHER SUCH WEAK SYSTEM
MAY BRING A FEW SHOWERS OR STORMS TO THE MISSOURI RIVER AREA LATE
FRIDAY NIGHT AND SATURDAY WHILE MOST OF THE AREA STAYS DRY.
TEMPERATURES FRIDAY AND SATURDAY SHOULD BE MODESTLY WARM AND CLOSE
TO NORMAL WITH 80S HIGHS.
WHAT I DESCRIBED YESTERDAY AS A SECONDARY SHORT WAVE IS NOR A
COOLING CANADIAN UPPER LOW WHICH WILL DIG TOWARD THE WESTERN GREAT
LAKES SUNDAY AND BEGIN TO CARVE OUT A LARGE SCALE TROUGH OVER THE
CENTRAL AND EASTERN USA. A FEW WEAK SHOWERS/STORMS SEEM POSSIBLE
NORTH AND EAST OF FSD SUNDAY AND WILL MENTION WITH SLIGHT CHANCE
POPS. SUNDAY WILL OF COURSE BE COOLER WITH MAINLY 70S HIGHS...80
OR SO SOUTHWEST. A MOSTLY DRY AND SOMEWHAT LASTING COOL PATTERN
THEN SEEMS IN STORE FOR THE AREA...BUT WENT WITH THE EXTENDED
GUIDANCE SLIGHT CHANCE OF STORMS FOR WEDNESDAY AS THE EC DOES SHOW
A SHORT WAVE WITH THE RIGHT TIMING...GFS BEING A LITTLE FASTER.
HOWEVER NOBODY IS GOING TO GET VERY MUCH RAIN WITH THE MOISTURE
VERY LIMITED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1055 PM CDT WED JUL 23 2014
VFR CONDITIONS ARE EXPECETD THROUGH THE TAF PERIOD. SCATTERED
THUNDERSTORMS ARE EXPECTED TO MOVE INTO SOUTH CENTRAL SD LATE TONIGHT
AND SLOWLY TRACK EASTWARD ACROSS THE AREA THROUGH THE DAY THURSDAY.
EXPECT ACTIVITY IN THE KHON AREA FROM 09Z TO 14Z AND INTO THE I29
CORRIDOR...INCLUDING FSD AND SUX AFTER 13Z. AGAIN...COVERAGE WILL BE
SCATTERED HOWEVER DID LEAVE TEMPO MENTION AT ALL 3 TAF SITES. THE
HIGH BASED STORMS WILL LIKELY KEEP CONDITIONS PREDOMINATELY IN
VFR...BUT STRONGER GUSTS AND VERY BRIEF MVFR CONDITIONS WILL BE
POSSIBLE IN THE STRONGER STORMS. BREEZY SOUTH SOUTHEAST WINDS PICK UP
AFTER 12Z AND PERIST THROUGH THE END OF THE TAF PERIOD.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...CHENARD
SHORT TERM...MJ/
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
149 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH THE AREA FROM THE NORTHWEST TONIGHT AND
CROSS THE MID ATLANTIC REGION THURSDAY. SCATTERED TO NUMEROUS SHOWERS
AND THUNDERSTORMS WILL ACCOMPANY THE FRONTAL PASSAGE. DRIER AIR
WILL MOVE INTO THE AREA BEHIND THE FRONT FRIDAY WITH A DAY OR TWO
OF DRY WEATHER...FRIDAY INTO SATURDAY. MOISTURE WILL QUICKLY RETURN
OVER THE WEEKEND WITH HEAT AND HUMIDITY HELPING TO TRIGGER MORE
THUNDERSTORM ACTIVITY. A STRONG FRONT IS EXPECTED TO CROSS THE
AREA LATE SUNDAY INTO MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 918 PM EDT WEDNESDAY...
STORMS IN EASTERN KY/WV ASSOCIATED WITH AN APPROACHING SHORTWAVE
IN THE LOWER OHIO VALLEY PICKING UP INTENSITY THIS EVENING AS THIS
ACTIVITY MOVES INTO UNSTABLE AIR...EVEN WITH THE LOSS OF HEATING.
00Z RNK SOUNDING SHOWED CAPES GREATER THAN 2800 J/KG.
23Z HRRR RUN CONTINUES THE TREND OF STRENGTHENING THIS ACTIVITY
AS IT MOVES INTO SOUTHEAST WV AND THE MOUNTAINS OF VA THIS
EVENING. AS A RESULT...INCREASED POPS IN THIS AREA UNTIL VERY LATE
IN THE NIGHT. WOULD ALSO NOT BE SURPRISED TO SEE STORMS RE- FIRE
ALONG DEVELOPING LEE-SIDE TROF IN THE VA SOUTHSIDE AND NC PIEDMONT
VERY LATE TONIGHT. ALSO INCREASED POPS IN THIS AREA.
NEXT QUESTION WILL BE PRECIPITATION TOMORROW IN ASSOCIATION WITH
APPROACHING COLD FRONT AS UPPER TROUGH AMPLIFIES OVER THE GREAT
LAKES. FRONTAL BOUNDARY WILL MAKE ITS WAY TOWARD THE WESTERN CWA
BY THU MORNING...AND MODELS DEVELOP FAIRLY WIDESPREAD COVERAGE OF
PRECIP ACROSS THE WEST EARLY TOMORROW AND SPREADING EAST ACROSS
THE PIEDMONT AS THE DAY PROGRESSES. THUNDER MAY BE LIMITED BY
CLOUD COVER AND LACK OF INSTABILITY ESPECIALLY ACROSS THE WESTERN
HALF OF THE CWA BUT OVERALL CHANCES FOR CONVECTION WILL INCREASE
OVER THE PIEDMONT LATER IN THE DAY WITH POSSIBLY SOME HEATING AND
MORE INSTABILITY. LOCALLY HEAVY RAINFALL WILL BE POSSIBLE AS WELL
WITH STILL VERY HIGH PWATS AHEAD OF THE FRONT. CLOUD COVER AND
HIGH DEWPOINTS WILL KEEP LOWS TONIGHT WELL ABOVE NORMAL RANGING
FROM MID 60S TO LOWER 70S...WITH DIURNAL RANGE LIMITED TOMORROW AS
WELL. HIGHS SHOULD BE 5 TO 8F LOWER THAN TODAYS WARM VALUES.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
AS OF 500 PM EDT WEDNESDAY...
SURFACE COLD FRONT IS EXPECTED TO SLIP SOUTHEAST OF OUR AREA
THURSDAY NIGHT BEFORE STALLING ALONG THE CAROLINA COAST FRIDAY.
MODELS MAINTAIN CONTINUITY WITH DRY HIGH PRESSURE BUILDING INTO
THE FORECAST AREA FROM THE NORTH. IN SPITE OF THE DRY
AIR...THICKNESSES DO NOT FALL THAT MUCH...SO DO NOT EXPECT MUCH IN
THE WAY OF A TEMPERATURE CHANGE. IF ANYTHING...INCREASED SUNSHINE
WILL HELP BOOST SURFACE TEMPERATURES TO AT LEAST OUR JULY NORMALS
FRIDAY...THEN BEGIN WARMING BACK UP SATURDAY AS SOUTHERLY FLOW
INCREASES BEHIND THE DEPARTING SURFACE HIGH.
FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT LATE IN THE WEEKEND. WILL HAVE TO
MONITOR THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL
SHOWERS AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...
STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.
DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.
ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
AS OF 135 AM EDT THURSDAY...
AVIATION CONCERNS THIS MORNING WILL BE CONVECTION THAT IS MOVING
SLOWLY EAST NORTH OF ROA AND NW OF LYH...WITH MAINLY SHOWERS
FURTHER WEST. WILL HAVE VCSH IN THE TAFS FOR NOW THEN SHOULD BE A
BREAK AROUND DAWN-14Z. MODELS ARE DEVELOPING SHOWERS BY 09Z ACROSS
THE NC PIEDMONT AND PUSHING IT TO DAN. NOT SEEING THIS YET...BUT
CONFIDENCE IS MODERATE IN THIS HAPPENING PER DEEP MOISTURE
CONVERGENCE. AMENDMENTS AS NECESSARY WILL OCCUR IF STORMS LOOK TO
PUSH INTO THE TERMINALS.
ASIDE FROM CONVECTION WILL BE DEALING WITH PERIODS OF MVFR FOG DUE
TO HIGHER MOISTURE LEVELS IN PLACE. CLOUDINESS THOUGH SHOULD LIMIT
THE LOWER VSBYS.
STORMS WILL RE-DEVELOP LATE MORNING AS A COLD FRONT MOVES THROUGH
THE AREA. THE COVERAGE OF THE CONVECTION IS NOT EXPECTED TO BE
WIDESPREAD ENOUGH TO INCLUDE IN THE TAF SITES...BUT DID ADD A VCTS
AT ALL TAF SITES. THREAT FOR PRECIPITATION SHOULD END EARLY IN THE
AFTERNOON IN THE WEST AS THE FRONT EXITS THE FORECAST AREA BETWEEN
18Z THUR AND 00Z FRI...LEAVING VFR CONDITIONS.
EXTENDED AVIATION DISCUSSION...
AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. OVERALL EXPECT SUB VFR AT TIMES THURSDAY WITH SHRA/TSRA
AND MAYBE SOME FOG THU NIGHT...FOLLOWED BY VFR FRI- SAT OUTSIDE OF
ANY VALLEY FOG AT KLWB/KBCB EACH MORNING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PC/PH
NEAR TERM...PH
SHORT TERM...PM
LONG TERM...PM
AVIATION...WP
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
1132 AM EDT THU JUL 24 2014
.UPDATE...
HAVE GONE THROUGH AND REDUCED POPS THIS MORNING BUT HAVE PRETTY
MUCH LEFT AFTERNOON TRENDS ALONE WITH THE APPROACH OF THE COLD
FRONT EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS. HRRR HAS BEEN
PRETTY STEADFAST IN DEVELOPING CONVECTION ACROSS NORTH GEORGIA
AROUND 18Z THOUGH SOME OTHER HIRES MODELS DID START BACKING OFF ON
CONVECTION WITH OVERNIGHT RUNS. TEMPERATURES IN PRETTY GOOD SHAPE
BUT DEWPOINTS ARE RUNNING HIGHER THAN FORECAST SO HAVE MADE SOME
TWEAKS THERE. ALL IN ALL...NOT ENOUGH CHANGE TO WARRANT AN UPDATE
TO ZONE PRODUCTS.
TDP
&&
.PREV DISCUSSION... /ISSUED 732 AM EDT THU JUL 24 2014/
SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
A COLD FRONT CURRENTLY ACROSS NORTH TN IS PROGGD BY MODELS TO SAG
SOUTHWARD TODAY. ALTHOUGH THE NAM IS SLIGHTLY SLOWER THAN THE GFS...
A BLEND IN TIMING WOULD PUSH THE FRONT INTO NORTH GA BY LATE THIS
MORNING... THEN ACROSS THE ATLANTA METRO AROUND LATE AFTERNOON OR
EARLY EVENING. THE NAM STALLS THE FRONT NEAR OR JUST NORTH OF
ATLANTA THIS EVENING... BUT EXPECT THE DEVELOPING MID TO UPPER NW
FLOW ALOFT TO BE SUFFICIENT TO PUSH THE FRONT SOUTH OF ATLANTA
TONIGHT AS THE GFS INDICATES. EITHER WAY...THE GREATER CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE DURING DAYTIME HEATING TODAY AS
WEAK DISTURBANCES TRAVERSE THROUGH THE UPPER TROUGH AND HELP SPARK
CONVECTION ALONG AND AHEAD OF THE SLOW MOVING FRONT. WITH SOME
UNCERTAINTY OF THE FRONTS LOCATION TONIGHT... WILL SHOW A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR ATLANTA AND AREAS SOUTHWARD
THROUGH MIDNIGHT... THEN SHIFT THIS POTENTIAL MAINLY SOUTH OF
ATLANTA AFTER MIDNIGHT. EXPECT A SLIGHTLY DRIER/COOLER AIR MASS TO
FILTER INTO NORTH GA TONIGHT AND POSSIBLY HANG AROUND ON FRIDAY...
BUT MODELS ARE HINTING AT THE FRONT DRIFTING BACK INTO NORTH GA
FRIDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO AT LEAST A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR AREAS FROM ATLANTA SOUTHWARD
ON FRIDAY.
ALTHOUGH CANNOT RULE OUT AN ISOLATED STRONG OR SEVERE STORM THIS
AFTERNOON WITH MODERATE CAPE VALUES IN THE 2000-2500 J/KG RANGE...
EXPECT THIS THREAT TO BE MINIMAL AS WIND SHEAR AND FRONTAL FORCING
WILL BE WEAK. SPC IS SHOWING ONLY A GENERAL THUNDER OUTLOOK FOR THE
AREA THROUGH FRIDAY... AND THIS LOOKS REASONABLE EACH DAY.
WIDESPREAD RAINFALL AMOUNTS SHOULD AVERAGE AROUND ONE HALF INCH OR
LESS... WITH SOME ISOLATED SLIGHTLY HIGHER AMOUNTS POSSIBLE.
THEREFORE... FLOOD PROBLEMS ARE NOT EXPECTED AT THIS TIME.
AS FOR TEMPS...CLOUDS AND PRECIP SHOULD HELP HOLD HIGHS DOWN IN THE
LOWER TO MID 80S ACROSS MAINLY NORTH GA TODAY WHILE CENTRAL GA HEATS
UP INTO THE UPPER 80S TO LOWER 90S. EXPECTING SLIGHTLY COOLER LOWS
MOSTLY IN THE 60S FOR MUCH OF NORTH GA TONIGHT BEHIND THE FRONT. THE
COOLER TEMPS ARE SHORT-LIVED AS HIGHS CLIMB BACK INTO THE UPPER 80S
TO LOWER 90S FOR MOST AREAS ON FRIDAY. A MAV AND MET BLEND WITH SOME
TWEAKS LOOKED REASONABLE THROUGH THE SHORT TERM.
39
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
MODELS CONTINUE TO SHOW A FEW UPPER LEVEL DISTURBANCES TO
TRAVERSE THE REGION OVER THE WEEKEND. SURFACE HIGH SHOULD KEEP
POPS TO A MINIMUM SATURDAY...AND WITH FRONT APPROACHING THE AREA
SUNDAY...HIGH WILL LOSE CONTROL OF THE AREA AND ALLOW FOR
INCREASING RAIN CHANCES. EXTENDED PERIODS ARE STILL LARGELY
DOMINATED BY THIS STRONG COLD FRONT /ANOMALOUS FOR LATE JULY/ AND
MODELS AGREE WITH PUSHING IT THROUGH NORTH AND CENTRAL GEORGIA BY
LATE MONDAY. DEEP LONGWAVE TROUGH REMAINS POSITIONED OVER THE AREA
THROUGH MUCH OF NEXT WEEK...KEEPING LOWER DEW POINTS AND COOLER
TEMPERATURES IN PLACE IN THE WAKE OF THE COLD FRONT. SOME MOISTURE
DOES LOOK TO CREEP BACK NORTHWARD AS BOUNDARY REMAINS OVER SOUTH
GEORGIA...AND HAVE GENERALLY INCLUDED SLIGHT CHANCE POPS IN THE FAR
SOUTHERN PORTIONS OF THE CWA THROUGH WEDNESDAY. BEGINNING
TUESDAY...SHOULD SEE BELOW AVERAGE TEMPERATURES WITH HIGHS IN THE
UPPER 70S NORTH AND LOW 80S ELSEWHERE...AND LOWS IN THE 60S.
STRONG TO SEVERE STORMS MAY ACCOMPANY THE FRONT AS IT PUSHES
THROUGH THE AREA MONDAY WITH MODELS CONTINUING TO ADVERTISE A
COMBINATION OF DECENT SHEAR AND INSTABILITY. WITH SOME UNCERTAINTY
IN THE FORECAST MODELS REGARDING THE TIMING OF THIS SYSTEM...THE
SEVERE POTENTIAL WILL NEED TO CONTINUE TO BE MONITORED.
31
AVIATION...
12Z UPDATE...
AREA OBS AND SATELLITE SHOW FEW-SCT MID LEVEL CLOUDS SPREADING IN
FROM THE NORTH AHEAD OF A COLD FRONT SAGGING INTO FAR NORTH GA THIS
MORNING. EXPECT VFR CONDITIONS TO PREVAIL UNTIL MID MORNING WHEN
DAYTIME HEATING AND THE APPROACHING COLD FRONT COMBINE TO INCREASE
MID LEVEL CLOUDINESS OVER THE ATLANTA TAF SITES. AHEAD OF THE
FRONT... EXPECT NUMEROUS SHOWERS WITH SCATTERED THUNDERSTORMS TO
DEVELOP... WARRANTING VCSH BY 17Z AND TEMPO -TSRA FROM 18-22Z. THE
FRONT SHOULD PUSH SOUTH OF ATL BY 23-24Z WITH ASSOCIATED MID LEVEL
CIGS SCATTERING. LIGHT SW WINDS WILL INCREASE TO AROUND 8-10KTS WITH
A FEW GUSTS AFTER 14Z TODAY. EXPECT NW WINDS AROUND 5KTS OR LESS AND
VFR CONDITIONS TONIGHT...WITH SCT MID CLOUDS BY 15Z FRI.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON ALL ELEMENTS.
39
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 69 89 69 / 60 30 20 10
ATLANTA 87 70 88 72 / 60 30 20 5
BLAIRSVILLE 82 61 83 61 / 60 20 10 5
CARTERSVILLE 87 68 88 68 / 60 20 10 5
COLUMBUS 89 73 90 74 / 60 30 30 10
GAINESVILLE 86 69 87 69 / 60 30 10 5
MACON 90 71 92 72 / 50 30 30 10
ROME 86 68 88 67 / 60 20 10 5
PEACHTREE CITY 88 69 88 69 / 60 40 20 10
VIDALIA 92 73 92 74 / 30 30 40 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS GOODLAND KS
933 AM MDT THU JUL 24 2014
.UPDATE...
ISSUED AT 924 AM MDT THU JUL 24 2014
CURRENT NEAR TERM FORECAST CONCERNS FOCUS ON HOW WARM THINGS WILL
GET THIS AFTERNOON COMBINED WITH MAGNITUDE OF DEWPOINT FALLS AS
DRYLINE DEVELOPS THIS AFTERNOON.
LATEST RAP AND HRRR AND TO A LESSER DEGREE THE NAM ARE SUPPORTING
A WELL MIXED VERY WARM PATTERN ACROSS THE CWA PUSHING HIGHS ABOVE
105 IN SEVERAL LOCATIONS. NOT TOTALLY SOLD ON THIS AS MODELS ARE
AGGRESSIVELY MIXING THINGS FASTER THAN CURRENT OBSERVATIONS. GOES
SOUNDER DATA DOES INDICATE AN AREA OF LOW PW`S NOSING INTO THE
WESTERN CWA AS OF 14Z...WHICH WOULD SUPPORT A LAYER OF DRIER AIR
OFF OF THE SURFACE WHICH COULD POTENTIALLY DILUTE SFC TDS THIS
AFTERNOON. HAVE LOWERED BOTH THE TD AND RAISED TEMPS A FEW DEGREES
BASED ON LATEST DATA AND WILL CLOSELY MONITOR TRENDS TO SEE IF
MUCH WARMER TEMPS ARE NEEDED.
GIVEN DRY AIR AND INCREASING SOUTHWESTERLY WINDS...FIRE WX MAY
BECOME A LARGE CONCERN THIS AFTERNOON ESPECIALLY NEAR RECENTLY
HARVESTED OR READY FOR HARVEST WHEAT FIELDS. CURRENTLY WIDESPREAD
CRITICAL FUELS ARE IN QUESTION THOUGH SO NOT SURE A RFW IS VALID
AT THIS POINT IN THE GREEN UP CYCLE. FOR THE TIME BEING...PLAN ON
HIGHLIGHTING POTENTIALLY CRITICAL LOCAL FIRE DANGER IN SPS FOR NOW
UNTIL FUEL INFORMATION BECOMES MORE APPARENT.
UPDATE ISSUED AT 630 AM MDT THU JUL 24 2014
SMALL AREA OF LOW STRATUS AND MINOR FOG HAS DEVELOPED TO THE EAST
OF SURFACE TROUGH STRETCHING FROM GARDEN CITY TO RUSSEL SPRINGS.
THIS IS NOT A PARTICULARLY WIDE AREA AND THINK MORNING SUN SHOULD
HELP MIX OUT FOG AND LOWER CLOUDS FAIRLY QUICKLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 324 AM MDT THU JUL 24 2014
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION AND HOW HOT DOES
IT GET. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE EASTERN
PACIFIC INTO THE WESTERN ATLANTIC. STRONG RIDGE CENTERED TO OUR
SOUTHWEST IS STARTING TO BE PUSHED SOUTH BY A STRONG UPPER SYSTEM
THAT IS NOW MOVING INTO THE PACIFIC NORTHWEST. STALLED FRONTAL
BOUNDARY IS NEAR THE WESTERN END OF OUR AREA.
AT MID LEVELS...MODELS TENDED TO BE A LITTLE TOO FAR EAST...
ESPECIALLY WITH THE PACIFIC NORTHWEST SYSTEM. OVERALL THE ECMWF WAS
DOING A LITTLE BETTER THAN THE GFS AND UKMET. AT LOW LEVELS...THE
ECMWF AND SREF WERE DOING THE BEST. THE ECMWF WAS DOING A LITTLE
BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...SURFACE TROUGH AND SHORTWAVE TROUGH MOVE INTO THE
WESTERN PORTION OF THE FORECAST AREA LATER THIS AFTERNOON. THERE IS
A DEEP DRY LAYER SHOWN BY THE MODEL SOUNDINGS WITH 700 MB
TEMPERATURES GREATER THAN +15. WILL KEEP A SLIGHT CHANCE OF
PRECIPITATION BUT PULL THE SLIGHT CHANCE BACK FURTHER WEST TOWARD
THE LIFT. THIS ALSO MATCHES WITH GEFS PROBABILITIES. NEW GUIDANCE
SUPPORTED ONLY MAKING SLIGHT ADJUSTMENTS TO THE HIGH TEMPERATURES.
QUESTION THEN BECOMES HOW FAR EAST DOES IT GO DURING THE NIGHT.
INITIALLY MOST OF THE LIFT ALOFT GOES ACROSS THE NORTHWEST HALF
DURING THE EVENING. HOWEVER...THE SURFACE TROUGH AND REMAINDER OF THE
SHORTWAVE GOES ACROSS DURING THE NIGHT. SINCE LIFT DOES NOT LOOK THAT
STRONG RIGHT NOW AND THERE IS A DEEP DRY LAYER WILL CONTINUE WHAT THE
DAY SHIFT PUT IN WHICH IS THE SLIGHT CHANCE ACROSS THE NORTHWEST HALF
DURING THE EVENING. THIS ALSO MATCHES WITH THE PROBABILITY FORECAST
WHICH DOES KEEP MEASURABLE A LITTLE FURTHER WEST AS WELL.
FRIDAY/FRIDAY NIGHT...MODELS NOW APPEAR A LITTLE SLOWER WITH THE
COLD FRONT...BEING PUSHED BY NORTHERN SYSTEM. IN FACT MOST OF THEM
STALL THE FRONT OVER THE CENTRAL/SOUTHEAST PORTION BY LATE IN THE
AFTERNOON. THIS THEN LOOKS TO PULL BACK TO THE NORTH DURING THE
EVENING BEFORE COMING THROUGH IN THE LATER HALF OF THE NIGHT.
ALSO A WEAKER SHORTWAVE WILL MOVE ACROSS WHERE THE FRONT WILL BE IN
THE AFTERNOON. AFTER THAT A MUCH STRONGER SHORTWAVE MOVES IN FROM
THE WEST DURING THE NIGHT. COMPLICATE THAT WITH 700 MB TEMPERATURES
NEAR OR ABOVE PLUS 15 AND A DEEP DRY LAYER IN THE BOTTOM HALF OF
THE ATMOSPHERE. STORM MOTIONS WILL BE VERY SLOW AS WELL. SO COULD
POSSIBLY HAVE THUNDERSTORMS DEVELOP NEAR/JUST WEST OF THE BOUNDARY
AND/OR COME OFF THE HIGHER TERRAIN TO THE WEST DUE TO THE SHORTWAVE
AND SOME UPSLOPE FLOW. WILL PUT SOME SLIGHT CHANCE POPS WITH THE
FRONT IN THE AFTERNOON.
QUESTION ONCE AGAIN IS HOW FAR EAST DOES THE CONVECTION GO AND HOW
LONG IT GOES INTO THE NIGHT. MODEL QPF AND PROBABILITY FORECASTS
TEND TO FAVOR THE WESTERN PORTION OF THE AREA AND TO OUR NORTH. RIGHT
THE CURRENT FORECAST IN THE EVENING LOOKS REASONABLE AND ONLY MADE A
SLIGHT ADJUSTMENT. HOWEVER WITH THE BOUNDARY AND DECENT LIFT MOVING
THROUGH IN THE LATTER HALF OF THE NIGHT...WILL INSERT A SLIGHT CHANCE
IN THE SOUTHEAST HALF.
HIGH TEMPERATURES WILL BE INTERESTING DEPENDING ON THE SPEED AND
POSITION OF THE FRONT. SINCE MODELS ARE SLOWER WITH THE FRONT...
MODEL TEMPERATURES ARE WARMER THAN THEY WERE YESTERDAY...ESPECIALLY
IN THE SOUTHEAST PORTION OF THE AREA. SO ENDED UP RAISING MAXES...
ESPECIALLY IN THE SOUTHEAST HALF.
SATURDAY/SATURDAY NIGHT...AT THIS TIME IT LOOKS LIKE THE FRONT IS
THROUGH THE ENTIRE AREA...NOT BY MUCH...BY EARLY AFTERNOON. SO AIR
MASS WILL BE COOLER WITH SOME WEAK UPSLOPE OCCURRING. THIS FRONT
CONTINUES TO MOVE SOUTH AND EAST THROUGH THE NIGHT. WITH THE FRONT
THROUGH THE AREA BELIEVE INITIALLY THAT THE PRECIPITATION WILL BE
TIED TO IT WITH THE MAIN AREA SOUTH AND EAST OF THE FORECAST AREA.
IT WILL BE POSSIBLE THAT THE FAR WEST WILL SEE SOME STORMS WITH THE
NEXT SHORTWAVE TROUGH APPROACHING THE POST FRONTAL UPSLOPE AIR
MASS. SO REDUCED POPS TO JUST THAT AREA IN THE AFTERNOON.
SHORTWAVE TROUGH MOVING THROUGH DURING THE NIGHT. BUT MODELS
DISAGREE ON WHERE THE BEST LIFT AND HOW MUCH INSTABILITY WILL BE
PRESENT. OVERALL SETUP AND PROBABILITIES SUPPORT THE SOUTHWEST HALF
OF THE FORECAST AREA AT THIS TIME. SO LEFT THE CURRENT FORECAST
ALONE.
EVEN THOUGH MOST OF THE AREA IS BEHIND THE FRONT BY SHORTLY AFTER
18Z...MODELS DISAGREE ON HOW MUCH COOLER AIR TO BRING INTO THE
AREA. ONCE AGAIN THE FURTHER NORTH AND WEST YOU GO...THE LESS HOT IT
WILL BE. AGAIN THE SOUTHEAST WILL SEE THE HOTTEST TEMPERATURES.
MADE ONLY MINOR ADJUSTMENTS TO ONGOING FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM MDT THU JUL 24 2014
FOR THE EXTENDED PERIOD...REGION WILL SEE PATTERN SHIFT AS MODELS
BEGIN TO STRENGTHEN H5/H7 RIDGES OVER THE WESTERN PORTIONS OF THE
COUNTRY...COUNTERACTED WITH A DEEPENING TROUGH/UPPER LOW SETTING UP
OVER THE GREAT LAKES/NORTHEAST REGIONS. UPPER FLOW AS A RESULT WILL
BE NORTHWEST OVER THE AREA FOR THE ENTIRE EXTENDED TIME FRAME. AT
THE SURFACE...A SERIES OF WEAK WAVES WILL MOVE OFF THE EASTERN
PORTION OF THE ROCKIES FOR SUNDAY INTO MONDAY NIGHT...FOLLOWED BY A
STRONGER LEE-SIDE TROUGH THAT SETS UP ON TUESDAY...SETTLING SOUTH OF
REGION EARLY WEDNESDAY AND THEN CONVERTING TO INVERTED TROUGH AND
MEANDER OF THE REGION THROUGH WEDNESDAY. THE RESULT OF THE SYNOPTIC
SETUP WILL BRING CHANCE FOR TRW/RW ALMOST EVERY DAY WITH BEST
CHANCES BEING TUESDAY INTO WEDNESDAY AND THIS IS WHERE HIGHEST POPS
(30-40) ARE HIGHLIGHTED...BEFORE THINGS WIND DOWN WEDNESDAY NIGHT
INTO THURSDAY. AS A RESULT OF THE BROAD NW UPPER FLOW AND EXPECTED
CLOUD COVER...TEMPERATURES WILL BE GENERALLY A FEW DEGREES BELOW
NORMAL WITH HIGHS IN THE 80S TO LOW 90S IN SPOTS. OVERNIGHT LOWS WILL
RANGE IN THE LOW/MID 60S AND WILL BE HAMPERED AT TIMES IF ANY
RESIDUAL CLOUDS REMAIN FROM CONVECTION DURING THE AFTERNOON/EVENING
HOURS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 515 AM MDT THU JUL 24 2014
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. SOME THIN AND
SHALLOW MAY BE AROUND FOR A VERY SHORT PERIOD OF TIME AFTER 12Z.
ONCE ENOUGH HEATING TAKES PLACE THE SOUTHERLY WINDS WILL BE GUSTY
WITH KGLD HAVING THE STRONGEST WINDS. SOME ISOLATED THUNDERSTORMS
ARE POSSIBLE LATE THIS AFTERNOON INTO THIS EVENING. SINCE IT IS
LATE IN THE PERIOD...AND COVERAGE LOOKS VERY SPOTTY...WILL NOT
INCLUDE ANY MENTION IN THE TAFS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JN
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS TOPEKA KS
636 AM CDT Thu Jul 24 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 12Z TAFs through 12Z Friday Morning)
Issued at 636 AM CDT THU JUL 24 2014
For the 12z TAFs, VFR conditions are expected through the period.
Calm winds this morning will increase out of the southeast today and
persist at roughly 8-10kts through the afternoon and evening hours.
Expect the wind direction to begin shifting more to the south by
Friday morning as the next system approaches the region.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Hennecke
AREA FORECAST DISCUSSION
NWS JACKSON KY
1107 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
655 AM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1040 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
...SURVEY TEAM HEADED TOWARD THE VA EASTERN SHORE ATTM...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY
TEAM ARRIVES ON SITE.
WILL DO A QUICK UPDATE TO GRIDS / ZFP WITH MAIN THREAT OF CONVECTION
THIS AFTRN FROM VA RT 460 ON SOUTH INTO NC AS COLD FRONT SLOWLY
SAGS SOUTH. SHWRS WITH EMBEDDED TSTRMS ACROSS THE NORTH.
PVS DSCN:
LATEST GOES WV SAT IMAGERY CONTINUES TO SHOW SHEARING OUT UPPER
DISTURBANCE OVER THE CENTRAL APPALACHIANS THIS MORNING, WITH THE
ASSOCIATED SFC BOUNDARY STALLED JUST TO OUR NW...AND EXTENDING
FROM NORTHERN NJ BACK INTO SOUTH CENTRAL PA AND NORTHERN KY.
SEEING SHOWERS REDEVELOPING AS EXPECTED OVER NORTHWESTERN VA/NC,
WITH A FEW ISO SHRAS PUSHING ACROSS FAR WESTERN AKQ PIEDMONT
COUNTIES AT 08Z. UPPER TROUGH AMPLIFYING TO THE WEST WL NUDGE THE
STALLED SFC FRONT SOUTH ACROSS THE LOCAL AREA LATER THIS MORNING
INTO TONIGHT. LATEST HRRR AND THE 00Z/24 NMM BOTH SUGGEST SHRA
ACTIVITY WILL CONTINUE TO PUSH E-NE ACROSS NORTHWESTERN HALF OF
THE CWA NOW THROUGH MID MORNING, DROPPING SE LATE THIS MORNING
INTO THE AFTERNOON, WITH THE FRONT EVENTUALLY SLOWING NEAR THE
NC/VA BORDER TONIGHT.
REGARDING SVR POTENTIAL...OVERCAST CONDITIONS AND TIMING OF
SHOWERS AND STORMS THIS MORNING AHEAD OF THE FRONTAL PASSAGE WILL
INHIBIT INSTABILITY AND ANY SIGNIFICANT INSTABILITY FOR MUCH OF
THE AREA. EXCEPTION WILL BE OVER AND SOUTH US-58 CORRIDOR OVER FAR
SOUTHERN/SE VA INTO NE NC. DEEP LYR SHEAR WILL BE A BIT MORE
FAVORABLE OVER THIS AREA AND WITH SBCAPE IN THE 1500-2000 J/KG
RANGE ALONG AND SOUTH OF THE BORDER, BEST CHANCE FOR ORGANIZED
CONVECTION WILL BE WITH LLVL CONVERGENCE/UVV ALONG DIFFERENTIAL
HEATING BOUNDARY ACROSS THE SOUTHERN TIER OF THE AREA. SEVERE
THREAT WOULD BE SHORT LIVED, BUT A FEW WET MICROBURSTS ARE
POSSIBLE OVER THIS AREA. BIGGER THREAT WILL BE WITH TRAINING
STORMS AS THE SLOWING BOUNDARY SAGS INTO THE AREA THIS AFTN/THIS
EVENING...PW`S IN THE 1.75-2" RANGE SHOULD YIELD LOCALLY HEAVY
RAINFALL, WITH DEEP LYR SW FLOW ESSENTIALLY PARALLEL TO BEST
FORCING LEADING TO A CONCERN FOR TRAINING STORMS/RAINS.
TEMPS A BIT OF A CHALLENGE TODAY GIVEN CONSIDERABLE CLOUDINESS
THROUGH THE DAY NORTH WHAT WILL LIKELY BE DEVELOPING AFTN CONVECTION
ACROSS THE SOUTH. CUT BACK HIGHS ACROSS THE NORTH SLIGHTLY (MID
80S), WHILE KEEPING SE COUNTIES IN THE UPR 80S TO ~90 DEG.
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
544 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 519 AM CDT THU JUL 24 2014
7K FOOT CIGS HAVE THWARTED THE FOG OVER WI THIS MORNING...SO
STARTING OFF ALL TERMINALS VFR. 6Z HOPWRF MEMBERS PICKED UP ON
DEVELOPING LINE OF STORMS OVER CENTRAL SODAK QUITE WELL...AND
BELIEVE THEIR EVOLUTION FOR THESE STORMS THIS MORNING...WHICH IS
TO DIMINISH THEM BEFORE THEY REACH MN...AS MOISTURE TRANSPORT AND
INSTABILITY DO NOT REALLY START TO SHOW UP IN MN UNTIL THIS
EVENING. FOLLOWED THE IDEA OF THE NAM/ECMWF FOR SHRA/TSRA
POTENTIAL TONIGHT...WHICH WILL BE GREATEST FROM RWF TO MSP AND
POINTS SOUTH. ENOUGH MODEL SPREAD EXISTS THOUGH TO KEEP ANY TSRA
MENTION TO A PROB30 AT THIS POINT. OTHER THAN THE LOWER CONFIDENCE
IN THE PRECIP POTENTIAL...CONFIDENCE IS HIGH IN REST OF THE TAF
COMPONENTS.
KMSP...WITH THE 6Z NAM LOOKING MUCH LIKE ITS 00Z COUNTERPART AND
THE 00Z ECMWF...RETAINED PROB30 TSRA MENTION BETWEEN 7Z AND 11Z.
AT THIS POINT...CONFIDENCE IN PRECIP POTENTIAL/TIMING NOT HIGH
ENOUGH TO GO WITH ANYTHING HIGHER THAN THE PROB30. FRIDAY
MORNING...THE GFS/NAM ARE HINTING AT THE POTENTIAL FOR MVFR CIGS
SO BROUGHT IN A SCT020 TO HINT AT THAT THREAT FOR NOW. OUTSIDE OF
THAT...VFR CONDS WILL PREVAIL WITH SSE WINDS INCREASING THIS
MORNING AND REMAINING FAIRLY PERSISTENT AROUND 10 KTS THROUGH THE
NIGHT.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR CIGS. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1024 AM EDT THU JUL 24 2014
.SYNOPSIS...
HEAT INDEX VALUES SHOULD TOP 100 DEGREES THIS AFTERNOON. A COLD
FRONT WILL APPROACH FROM THE NORTHWEST TODAY...BRINGING AN
INCREASING RISK FOR STRONG THUNDERSTORMS LATE THIS AFTERNOON INTO
TONIGHT. THIS FRONT WILL STALL ACROSS THE AREA FRIDAY BEFORE
DISSIPATING ON SATURDAY. HIGH PRESSURE WILL BRING HOT AND HUMID
CONDITIONS SUNDAY AND MONDAY. A STRONG COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...BRINGING COOLER AND DRIER CONDITIONS FOR THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...CLEAR SKIES OVER THE AREA THIS MORNING
SHOULD TURN PARTLY CLOUDY OVER THE NEXT FEW HOURS. TEMPERATURES ARE
SOARING QUICKLY WITH MID TO UPPER 80S ALREADY OBSERVED. THE LATEST
FEW HRRR RUNS PLUS THE 00Z NSSL WRF ARE SHOWING A LATER CONVECTIVE
INITIATION TIME THAN OUR PREVIOUS FORECAST INDICATED...SO I HAVE
SHIFTED THE WINDOW OF HIGHEST FORECAST POPS INTO THE 4 PM TO 10 PM
RANGE. THIS ALSO IS WHEN WE COME UNDER THE BEST INFLUENCE OF THE
RIGHT-ENTRANCE REGION OF A HEALTHY 300 MB JET EXTENDING FROM THE
MID-ATLANTIC INTO THE CANADIAN MARITIMES. NO OTHER SIGNIFICANT
CHANGES ARE NEEDED...AND FORECAST TEMPERATURES/DEWPOINTS STILL
SUPPORT HEAT INDICES IN THE 100-104 RANGE THIS AFTERNOON. PREVIOUS
DISCUSSION FROM 600 AM FOLLOWS...
A QUICK MOVING MID-LEVEL SHORTWAVE MOVED ACROSS THE UPSTATE OF SOUTH
CAROLINA DURING THE LATE NIGHT AND WAS CURRENTLY MOVING NE ACROSS
CENTRAL NORTH CAROLINA. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED IN
RESPONSE TO THIS ADDED LIFT AND ARE EXPECTED TO PASS BY TO OUR NORTH
THROUGH 9 AM. A WEAKER SECONDARY IMPULSE WAS MOVING NE ACROSS THE
EASTERN CAROLINAS...BUT CONVECTION HAS NOT DEVELOPED IN RESPONSE TO
THIS FEATURE.
A COLD FRONT WILL DROP INTO THE LEE SIDE TROUGH POSITION TODAY
AND THE FRONT WILL THEN SLIDE ACROSS THE FORECAST AREA TONIGHT...
LIKELY LYING ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA AT DAYBREAK FRI. THE UPPER TROUGH WILL STILL BE UPSTREAM FRI
MORNING.
THE ATMOSPHERE WILL BE WARM AND MOIST THROUGH A DEEP LAYER WITH
PRECIPITABLE WATER VALUES INCREASING THROUGH THE AFTERNOON/EVE...
IN EXCESS OF 2 INCHES...AND ALONG THE COAST...ABOVE 2.25 INCHES.
TEMPERATURES ARE EXPECTED TO REACH THE LOWER TO MID 90S TODAY. THIS
WILL BRING MIXED LAYER CAPE VALUES IN THE NEIGHBORHOOD OF 2000-2500
J/KG. MID LEVEL LAPSE RATES AND SHEAR VALUES ARE UNIMPRESSIVE...BUT
MID-LEVEL WINDS WILL BE ON THE ORDER OF 40 KT. THE BIGGEST RISK WITH
THUNDERSTORMS TODAY AND TONIGHT WILL BE FREQUENT LIGHTNING AND HEAVY
RAIN...ALTHOUGH STORM MOTIONS ARE MUCH HIGHER THAN EARLIER IN THE
WEEK WHICH SHOULD LIMIT THE EXCESSIVE RAINFALL THREAT. HOWEVER...THE
DEEPEST CONVECTION WILL BE CAPABLE OF STRONG WIND GUSTS AND AN
ISOLATED WET MICROBURST WITH DAMAGING WINDS CAN NOT BE RULED OUT.
THUNDERSTORMS MAY DEVELOP ALONG THE COAST AS A RATHER SHARP
SEABREEZE BOUNDARY DEVELOPS LATER THIS MORNING/MIDDAY. ELSEWHERE...
AFTERNOON THUNDERSTORMS WILL POP AS THE CONVECTIVE TEMPS ARE
EXCEEDED. THE CONVECTION SHOULD TEND TO BECOME MORE ORGANIZED MID
AND LATE AFTERNOON AS IT MOVES TOWARD THE COAST. WE EXPECT
CONVECTION TO LAST WELL INTO THE NIGHT IF NOT THROUGH THE NIGHT AS A
MODEST SHORTWAVE ALOFT INTERACTS WITH THE SURFACE FRONT.
HEAT INDEX VALUES LATE MORNING AND THIS AFTERNOON WILL REACH 100
DEGREES IN MOST AREAS AND AS HIGH AS 104 DEGREES. OF COURSE...ONCE A
STRONG THUNDERSTORM MOVES OVERHEAD...THE HEAT WILL GET KNOCKED
DOWN...BUT NOT THE HUMIDITY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...COLD FRONT STALLED ACROSS THE AREA WILL
CONTINUE SHOWER AND THUNDERSTORM CHANCES ON FRIDAY...BUT AT THE SAME
TIME DRIER AIR WILL BEGIN TO ADVECT IN FROM THE WEST...DRYING OUT
THE MID AND UPR PORTIONS OF THE COLUMN. STILL...WITH THE FRONT IN
PLACE...TEMPS RISING TO AROUND 90...AND DEWPOINTS IN THE LOW
70S...THERE WILL BE PLENTY OF FUEL AROUND FOR CONVECTION BEFORE THE
DRIER AIR WORKS INTO THE CWA. THUS WILL CARRY CHC POP
FRIDAY...HIGHEST ACROSS THE EASTERN PORTIONS OF THE CWA. THE DIURNAL
TREND FOR CONVECTION MAY BE A BIT ATYPICAL AS THE DRY AIR INTRUDES
OVERHEAD...AND THE HIGHEST COVERAGE OF CONVECTION MAY BE LATE
MORNING/EARLY AFTN BEFORE TAPERING OFF INTO THE EVE. THIS FRONT WILL
WASH OUT FRIDAY NIGHT LEAVING MOSTLY CLEAR SKY CONDITIONS...BUT AS
LIGHT SW FLOW RE-DEVELOPS...MINS WILL FALL ONLY INTO THE MID 70S AT
THE COAST...AND TO AROUND 70 INLAND.
ANY AIRMASS CHANGE ASSOCIATED WITH THE PRIOR FRONT QUICKLY ERODES
SATURDAY...LEAVING A HOT DAY ACROSS THE CWA. FORTUNATELY...THE
COLUMN WILL BE DRIER...AND THUS HUMIDITY VALUES WILL BE MUCH
LOWER...KEEPING APPARENT TEMPS TO BELOW 100 EVEN AS HIGHS CLIMB TO
AROUND 90 AT THE COAST...MID 90S WELL INLAND. WILL CONTINUE WITH THE
INHERITED SCHC POP ON SATURDAY SIMPLY DUE TO THE HEAT...BUT ONLY
ISOLATED STORMS ARE POSSIBLE AS PWATS DROP TO LESS THAN 1.5 INCHES.
INCREASING SW RETURN FLOW SATURDAY NIGHT WILL PREVENT SIGNIFICANT
COOLING...AND THUS LOWS SAT NIGHT WILL BE WELL ABOVE NORMAL...UPR
70S AT THE BEACHES TO LOW 70S ONLY WELL INLAND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...A HOT START TO THE PERIOD...BUT IT WILL BE
SHORT LIVED AS...ONCE AGAIN...AN ANOMALOUSLY STRONG UPPER TROUGH
DIVES ACROSS THE EASTERN CONUS.
SUNDAY LOOKS TO BE THE HOTTEST DAY OF THE PERIOD AS SUBTLE MID-LEVEL
RIDGING AND STRONG SW RETURN FLOW AROUND A RIDGE OF HIGH PRESSURE
PUSH TEMPS INTO THE MID AND MAYBE UPR 90S...AND WE MAY EXPERIENCE
OUR FIRST HEAT ADVISORY OF 2014 (HEAT INDEX OF 105 OR GREATER).
ALTHOUGH HUMIDITY WILL INCREASE ON SUNDAY AS WELL...CONVECTIVE
COVERAGE MAY BE QUITE LIMITED DUE TO SOME MID-LEVEL DRY AIR
PERSISTING...AND A LID WITHIN A LOW-LEVEL THERMAL RIDGE. MONDAY WILL
BE SIMILAR...ALTHOUGH A DEGREE OR 2 COOLER AS CLOUD COVER INCREASES
AND MID-LEVEL HEIGHTS DECREASE AHEAD OF AN ADVANCING COLD FRONT.
INCREASING POP IS WARRANTED MONDAY AS WELL...WITH THE BEST CHANCE
OCCURRING MONDAY NIGHT AS THE COLD FRONT MOVES INTO THE AREA. LOWS
BOTH NIGHTS WILL BE ABOVE NORMAL IN MID AND UPR 70S.
BIG AIR MASS CHANGE OCCURS THEREAFTER AS -3 SD TROUGH DROPS INTO
THE MIDWEST...DRIVING A STRONG COLD FRONT INTO THE CWA AND OFFSHORE
DURING TUESDAY. THIS TROUGH WILL PRODUCE LOWERED HEIGHTS ALL THE WAY
INTO THE GULF OF MEXICO THROUGH THE MIDDLE OF NEXT WEEK...BUT
FORTUNATELY FOR THE AREA THE TROUGH AXIS REMAINS DISPLACED WEST OF
THE COASTAL CAROLINAS. WHILE DRIER AND COOLER AIR IS ANTICIPATED
TUE/WED...WITH TEMPS RUNNING SEVERAL DEGREES BELOW NORMAL...LOCALLY
WE WILL NOT BE AS COOL AS OUR NEIGHBORS WELL WEST. LOWER POP IS
EXPECTED THROUGH MID-WEEK...BUT INCREASING E/NE FLOW MAY ALLOW FOR
RESIDUAL RAIN CHANCES TO PERSIST ALONG THE COAST THROUGH THE END OF
THE PERIOD.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...POSSIBLE MVFR/IFR IN ANY HEAVY DOWNPOURS THIS AFTERNOON
AND EVENING AS CHANCES FOR SHRA/TSRA INCREASING THROUGHOUT THE
DAY...ALONG WITH PATCHY FOG POSSIBLE BEFORE DAYBREAK ON FRIDAY.
OTHERWISE EXPECT VFR.
WITH SOUTHWEST WINDS AOB 10 KTS...VFR PREVAILS THIS MORNING ACROSS
THE AREA...WITH THE EXCEPTION OF KLBT WHICH IS EXPERIENCING IFR DUE
TO LOW CIGS. WOULD NOT ENTIRELY RULE OUT A VERY BRIEF PERIOD OF IFR
AT KFLO AS WELL IN THE NEXT HOUR OR TWO AS LOW CIGS MOVE ABOUT THE
INLAND AREAS AS SEEN FROM LATEST 11.9-3.9 SATELLITE IMAGERY.
AFTER 14Z...EXPECT ALL SITES TO BE VFR WITH SOUTHWEST WINDS AOB 12
KTS AHEAD OF AN APPROACHING COLD FRONT AND GUSTS INCREASING TO
AROUND 20 KTS BEGINNING OVER THE NEXT FEW HOURS. CHANCES WILL
INCREASE FOR SHOWERS AND THUNDERSTORMS THROUGHOUT THE DAY WITH THE
COLD FRONT...AND THOUGH THUNDERSTORMS WILL TAPER OFF THIS
EVENING...ANTICIPATE SHOWERS TO PERSIST INTO THE EARLY OVERNIGHT
HOURS. BRIEF PERIODS OF MVFR/IFR ARE POSSIBLE IN ANY SHRA/TSRA
ESPECIALLY WITH HEAVIER DOWNPOURS AND LOWER CIGS. LATE OVERNIGHT
INTO THE EARLY MORNING HOURS...MVFR IS POSSIBLE DUE TO PATCHY FOG.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE THROUGH
FRIDAY...AS WELL AS SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...WEST-SOUTHWEST WINDS ARE ALREADY GUSTING TO
20 KNOTS AT THE OCEAN CREST PIER ON OAK ISLAND...WITH 12-15 KNOTS
PREVAILING ELSEWHERE. NO SIGNIFICANT CHANGES ARE NEEDED TO THE
PREVIOUS FORECAST...EXCEPT FOR LOWERING SEA HEIGHTS BY ABOUT 1 FOOT
INITIALLY BASED ON AVAILABLE BUOY DATA. PREVIOUS DISCUSSION FROM 600
AM FOLLOWS...
A TIGHTER PRESSURE GRADIENT WILL BE REALIZED TODAY INTO THIS EVENING
AS A RATHER IMPRESSIVE TROUGH FOR THIS TIME OF YEAR APPROACHES.
SOUTHWEST SUSTAINED WIND SPEEDS ARE EXPECTED TO REACH 20 KT WITH
GUSTS TO 25 KT. SEAS TODAY ARE EXPECTED TO REACH UP TO 4 TO 5
FT...WITH SOME 6 FT SEAS POSSIBLE ACROSS THE OUTERMOST WATERS LATE
DAY AND THIS EVE. AT THIS TIME...WILL ISSUE A SMALL CRAFT SHOULD
EXERCISE CAUTION HEADLINE. THE FRONTAL ZONE SHOULD BE NEARING THE
WATERS LATE TONIGHT AND EXPECT THE WIND DIRECTION OVERNIGHT WILL
VEER TO A MORE WESTERLY DIRECTION WITH WIND SPEEDS DECREASING TO 10
TO 15 KT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WESTERLY WINDS WILL BEGIN THE PERIOD AS A
COLD FRONT WAVERS JUST OFF THE COAST. THIS FRONT WILL LIFT SLOWLY
BACK TO THE NORTH DURING FRIDAY...WITH WINDS REMAINING
LIGHT...AROUND 10 KTS...BUT BACKING TO THE SW THROUGH SUNDAY
MORNING. THEREAFTER...WINDS WILL INCREASE THROUGH SATURDAY AS THE
PRESSURE GRADIENT TIGHTENS ABOUT AROUND HIGH PRESSURE RIDGING BACK
TOWARDS THE COAST...WITH SPEEDS RISING FROM THE SW TO AROUND 15 KTS.
SEAS WILL BE 3-4 FT EARLY FRIDAY...AND RISE AGAIN TO 3-4 FT LATE
SATURDAY. IN BETWEEN 1-3 FT SEAS WILL BE COMMON THANKS TO THE
EXTENDED PERIOD OF LIGHTER WINDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...HIGH PRESSURE OFFSHORE RIDGING TOWARDS THE
COAST...AND A STRONG COLD FRONT SLOWLY APPROACHING FROM THE
NW...WILL PINCH THE GRADIENT SUNDAY AND MONDAY. THIS DRIVES SW WINDS
UP TO 20 KTS OR MORE BOTH DAYS...AND PUSHES WIND-DRIVEN SEAS UP TO
4-6 FT. AN SCA MAY BE NEEDED FOR AN EXTENDED PORTION OF THIS PERIOD
AHEAD OF THE COLD FRONT WHICH IS PROGGED TO CROSS THE WATERS BY
TUESDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
630 AM EDT THU JUL 24 2014
.SYNOPSIS...A COLD FRONT WILL PUSH SOUTHEASTWARD THROUGH THE REGION
LATE TODAY THROUGH TONIGHT. THIS FRONT WILL STALL OUT NEAR THE SOUTH
CAROLINA BORDER ON FRIDAY... AS WEAK HIGH PRESSURE BUILDS IN FROM
THE NORTH. THIS FRONT WILL THEN WEAKEN AND HEAD BACK NORTH OF THE
AREA OVER THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 320 AM THURSDAY...
IT`S LOOKING LIKE THE BROAD BROKEN BAND OF PREFRONTAL SHOWERS AND
STORMS WILL MOVE INTO AND THROUGH THE CWA FAIRLY EARLY TODAY...
DURING THE MORNING THROUGH MID AFTERNOON... WHICH COULD CUT DOWN ON
OUR SEVERE THREAT OVER ALL BUT THE SE AND EXTREME ERN CWA. THE
LATEST SURFACE MAP SHOWS THE INCOMING SURFACE FRONT STRETCHING
ACROSS THE OH VALLEY... WITH A PREFRONTAL TROUGH EXTENDING THROUGH
CENTRAL VA AND THE NC FOOTHILLS. WE`RE ALREADY STARTING TO SEE A FEW
SHOWERS FORMING ESE OF THIS CONVECTION OVER THE EAST SLOPES... AND
THE HRRR SHOWS THIS MORE EASTERLY ACTIVITY EXPANDING AND BECOMING
THE DOMINANT PREFRONTAL CONVECTION THIS MORNING AS IT HEADS INTO THE
TRIAD REGION... EVENTUALLY SHIFTING EAST THROUGH THE PIEDMONT
THROUGH THE NOON HOUR. THE LARGER SCALE MODELS SUGGEST THIS AS
WELL... DEPICTING PRETTY GOOD COVERAGE OF PRECIP OVER NEARLY THE
ENTIRE CWA BY 18Z. GIVEN THIS TREND IN BOTH RADAR IMAGERY AND MODEL
OUTPUT... WILL FOLLOW THIS PATH AND BRING IN HIGH CHANCE TO LIKELY
POPS EARLIER THIS MORNING OVER THE WRN/NRN CWA... HIGHEST ACROSS THE
NRN HALF OF THE FORECAST AREA FROM LATE MORNING INTO EARLY
AFTERNOON. THE FOCUS OF THE GREATEST CONVECTION COVERAGE SHOULD THEN
SHIFT TO THE COASTAL PLAIN AND SANDHILLS FROM MID AFTERNOON TO EARLY
EVENING AS THE PREFRONTAL TROUGH PUSHES SOUTHEASTWARD THROUGH THE
CWA. BUT ADDITIONAL SCATTERED SHOWERS/STORMS ARE EXPECTED JUST AHEAD
OF AND WITH THE COLD FRONT ITSELF... WHICH IS EXPECTED TO REACH THE
SPINE OF THE APPALACHIANS BY 00Z THIS EVENING... PROPELLED BY
RELATIVELY COOL HIGH PRESSURE CENTERED NEAR CHICAGO. THE SOUTHEAST
MOVEMENT OF THIS FRONT IS APT TO BE SLOWED BY THREE FACTORS: THE
EXTRA EFFORT IT WILL TAKE THE DENSER HIGH PRESSURE AREA TO GET OVER
THE MOUNTAINS... A STEERING FLOW THAT WILL BE NEARLY PARALLEL TO THE
SURFACE FRONT... AND EXPECTATIONS OF SURFACE LOW PRESSURE
ENHANCEMENT OVER THE SOUTHERN FOOTHILLS TONIGHT. GIVEN THE POTENTIAL
FOR A DELAY IN THE ARRIVAL OF THE DRIER AND MORE STABLE COLUMN FROM
NW TO SE UNTIL THE OVERNIGHT HOURS... WILL HOLD CHANCE POPS THROUGH
THE MID-LATE EVENING AREAWIDE BEFORE TRENDING THEM DOWN AND OUT NW
TO SE LATE TONIGHT.
REGARDING THE RISK OF STRONG/SEVERE STORMS... AS NOTED ABOVE... THIS
RISK LOOK GREATLY LIMITED ACROSS THE NRN AND FAR WRN CWA DUE TO
CLOUD COVER AND EARLY PRECIP ARRIVAL. CHANCES ARE BETTER IN THE
SOUTHEAST AND EXTREME EAST... WHERE THE NAM DEPICTS MLCAPE NEAR 1500
J/KG LATE MORNING INTO EARLY AFTERNOON. WE`VE GOT IMPROVED DEEP
LAYER SHEAR TO 25-35 KTS AS WELL. BUT THE ENTIRE TIMING OF THIS
SYSTEM (WELL BEFORE MAX HEATING) AND EARLY CLOUD COVER SHOULD KEEP
INSTABILITY DOWN. BUT THE NRN/WRN CWA IS NOT OUT OF THE WOODS AS WE
MAY ACTUALLY HAVE A BIT MORE CONCERN LATE THIS AFTERNOON THROUGH
EARLY EVENING AHEAD OF THE FRONT... IF WE CAN GET PARTIAL CLEARING
BEHIND THIS MORNING ACTIVITY. THE GFS SHOWS INITIALLY SMALL MUCAPE
IN THE MORNING IN THE NW CWA REBOUNDING ABOVE 1000 J/KG LATE
TODAY... NOT A HUGE NUMBER OF COURSE BUT ENOUGH TO RETAIN AT LEAST
SOME CONCERN FOR A STRONG WIND-PRODUCING STORM OR TWO AREAWIDE.
WHILE CELL MOTIONS ARE EXPECTED TO BE GREATER THAN IN PREVIOUS
DAYS... WE MAY SEE TRAINING CELLS REPEATEDLY OVER THE SAME AREA...
AND A RISK OF LOCALLY HIGH RAIN TOTALS WILL PERSIST.
TEMPS SHOULD INITIALLY BE HELD DOWN BY CLOUDS AND PATCHY PRECIP THIS
MORNING... BUT ANY THIN SPOTS IN THE CLOUDS BETWEEN THIS PREFRONTAL
CONVECTION AND SHOWERS/STORMS IMMEDIATELY AHEAD OF THE FRONT WILL
PUSH TEMPS UP QUICKLY. SO STILL EXPECT HIGHS FROM 86 TO 92. LOWS
TONIGHT 66-72... STILL MUGGY ACROSS THE SE. -GIH
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 320 AM THURSDAY...
FOR FRI/FRI NIGHT: LITTLE CHANGED NEEDED TO EXISTING FORECAST. STILL
EXPECT THE FRONT TO HANG UP ACROSS THE SE CWA AND ALONG THE
CENTRAL/WRN NC/SC BORDER... AS THE 850 MB TROUGH HOLDS TO ITS NW
ACROSS FAR NRN NC. THIS WILL KEEP ENOUGH LOW LEVEL MOISTURE WHICH...
IN CONJUNCTION WITH LINGERING PW VALUES NEAR 1 INCH... NECESSITATES
A MENTION OF ISOLATED TO SCATTERED SHOWERS AND STORMS OVER THE FAR
SE CWA... FOCUSED ON THE TYPICAL AFTERNOON THROUGH EARLY EVENING
TIME FRAME. MUCH LOWER PW OVER THE REMAINDER OF THE CWA AND MODEST
RISE IN HEIGHTS AS THE MID LEVEL TROUGH WEAKENS AND STARTS TO PULL
AWAY WILL LEAD TO MAINLY DRY WEATHER ELSEWHERE... ALTHOUGH ONE LAST
SHOT OF DPVA THROUGH THE EXITING TROUGH BASE WILL DELAY THE MOST
SUBSTANTIAL NW-TO-SE CLEARING UNTIL LATE IN THE DAY. HIGHS 85-90...
WITH THICKNESSES SLIPPING TO 10-15 M BELOW NORMAL. LOWS 65-71. -GIH
SAT AND SAT NIGHT: THE REMNANT FRONT FROM EARLY IN THE PERIOD WILL
BECOME INCREASINGLY DIFFUSE AS IT RETREATS NORTH ACROSS THE MIDDLE
ATLANTIC STATES ON SAT...WITH A PRIMARY IMPACT FOR CENTRAL NC BEING
THE DEVELOPMENT OF A WARMING SOUTHERLY FLOW - HIGH TEMPERATURES
GENERALLY BETWEEN 89 AND 93 DEGREES. ALOFT...MODEL GUIDANCE IS IN
GOOD AGREEMENT REGARDING THE PROGRESSION OF A MID LEVEL TROUGH FROM
THE APPALACHIAN SPINE SAT MORNING TO THE COAST BY EVENING...BUT
ASSOCIATED FORECAST VERTICAL MOTION WITH THIS FEATURE IS WEAK...AND
NAM FORECAST BUFR SOUNDINGS ARE AN UNSTABLE AND UNCAPPED OUTLIER
RELATIVE TO THE GFS AND SREF ENSEMBLE MEAN. THE NAM QPF MAXIMUM FROM
SE VA THROUGH CENTRAL NC IS ALSO AN OUTLIER RELATIVE TO OTHER
GUIDANCE...WHICH OTHERWISE CONFINES ANY SHOWERS/STORMS TO THE SEA
BREEZE. WILL CONSEQUENTLY MAINTAIN JUST A SLIGHT CHANCE POP OVER THE
SOUTHERN AND CENTRAL COASTAL PLAIN...WHERE WEAK LIFT AHEAD OF THE
AFOREMENTIONED TROUGH ALOFT WILL BE DIURNALLY MAXIMIZED AND
COINCIDENT WITH LOW LEVEL FORCING INVOF THE SEA-BREEZE/SUBSEQUENT
OUTFLOW DURING THE MID-LATE AFTERNOON.
SHORTWAVE RIDGING WILL BRIEFLY FOLLOW FOR SAT NIGHT...WITH DRY
CONDITIONS AND LOWS MAINLY IN THE LOWER 70S.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 335 AM THURSDAY...
THE MEDIUM RANGE WILL BE CHARACTERIZED BY THE DEVELOPMENT OF ANOTHER
UNSEASONABLY HIGH AMPLITUDE TROUGH ALOFT FROM SOUTHEASTERN CANADA
INTO THE EASTERN US...WITH AN ASSOCIATED NEGATIVE HEIGHT OF NEARLY 3
STANDARD DEVIATIONS BELOW AVERAGE FROM THE LOWER GREAT LAKES/OHIO
VALLEY TO THE CENTRAL APPALACHIANS. PRECIPITATION CHANCES DURING THE
PERIOD WILL BE HIGHEST SUN NIGHT-MON...AS THE TROUGH AMPLIFIES
SOUTHEASTWARD AND SPREADS THE ASSOCIATED MID LEVEL HEIGHT FALLS AND
UNDERLYING LO LEVEL FRONTAL ZONE ACROSS NC.
IN FACT...THE DAY SUNDAY SHOULD BE MAINLY DRY...AND HOT AS THE MID
LEVEL RIDGE OVER THE DESERT SW AND PLAINS BUILDS BRIEFLY EAST IN
ADVANCE OF THE AMPLIFYING TROUGH ALOFT. H85 TEMPERATURES ARE
FORECAST TO SURGE...ALBEIT BRIEFLY...INTO THE 22-24 DEGREE RANGE
OVER THE CAROLINAS...SUPPORTIVE OF HIGH TEMPERATURES SOLIDLY IN THE
MIDDLE 90S. UPSTREAM PRE-FRONTAL CONVECTION AND ASSOCIATED OUTFLOW
WILL THEN LIKELY DRIFT...IN A GRADUALLY WEAKENING STATE OWING TO
NOCTURNAL COOLING...INTO THE NORTHERN AND WESTERN PIEDMONT DURING
THE EVENING AND EARLY NIGHTTIME HOURS.
THE PATTERN ON THE SYNOPTIC SCALE...CHARACTERIZED BY THE APPROACHING
STRONG TROUGH AND DOWNSTREAM JET ENTRANCE DIVERGENCE ALOFT...AND LOW
LEVEL FRONTAL FORCING...FAVORS CONSIDERABLE THUNDERSTORM COVERAGE
MON...INCLUDING SOME SEVERE OWING TO UNSEASONABLY STRONG MID LEVEL
FLOW ON THE ORDER OF 40-50 KTS. HOWEVER...PREDICTABILITY ASSOCIATED
WITH MESOSCALE INFLUENCES (IE. OUTFLOW AND CLOUD COVER) FROM EARLIER
CONVECTION SUN NIGHT COMPLICATE THE FORECAST SO PROBABILITY OF
PRECIPITATION WILL BE KEPT IN THE HIGH CHANCE RANGE FOR NOW...WITH
THE EXPECTATION THAT THESE PROBABILITIES WILL BE INCREASED OVER AT
LEAST A PORTION OF THE FORECAST AREA (LIKELY THE SOUTHEAST HALF).
THE MIDDLE OF THE WEEK SHOULD BE DRY...AND COOLER...AS POST-FRONTAL
HIGH PRESSURE BUILDS INTO THE CENTRAL APPALACHIANS...AND
PRECIPITABLE WATER VALUES FALL BELOW AN INCH OVER CENTRAL NC. HIGHS
AND LOWS ONLY IN THE LOWER TO MIDDLE 80S AND LOWER TO MIDDLE
60S...RESPECTIVELY...TUE-WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 630 AM THURSDAY...
VFR CONDITIONS ARE LIKELY TO DOMINATE TODAY AT ALL TAF SITES...
ALTHOUGH SCATTERED CLOUDS BASED AT 600-900 FT WILL PASS OVER OR NEAR
RDU/RWI/FAY THROUGH 14Z. CURRENTLY THE VAST MAJORITY OF CLOUD COVER
OVER CENTRAL NC IS LIMITED TO HIGH CLOUDS BASED ABOVE 10 000 FT
AGL... AND WHILE CIGS WILL BE DROPPING AHEAD OF THE COLD FRONT
APPROACHING FROM THE NW... THEY SHOULD STAY VFR. THE EXCEPTION WILL
BE IN/NEAR SCATTERED TO NUMEROUS SHOWERS AND STORMS THAT ARE
OCCURRING NEAR INT/GSO... WHERE CIGS/VSBYS MAY DROP TO MVFR... ALONG
WITH ENHANCED WIND GUSTS. THESE SHOWERS/STORMS ARE THEN EXPECTED TO
AFFECT RDU AND RWI STARTING AROUND 13Z OR 14Z... AND FAY STARTING AT
17Z OR 18Z. ADDITIONAL SCATTERED STORMS ARE POSSIBLE MAINLY AT
INT/GSO/RDU DURING THE MID-LATE AFTERNOON... BUT UNCERTAINTIES
REGARDING COVERAGE AND TIMING PRECLUDE MENTIONING THESE IN THE TAFS
AT THIS TIME. TOUGH CALL ON WHEN THE STORM THREAT WILL EXIT TAF
SITES... BUT VFR CONDITIONS SHOULD RETURN SOON AFTER 22Z AT GSO...
00Z AT RDU/RWI... AND PROBABLY NOT UNTIL AFTER 04Z AT FAY. SURFACE
WINDS WILL REMAIN FAIRLY LIGHT LATE TONIGHT BUT SHIFT AROUND TO
MAINLY NNE AS THE FRONT PUSHES SOUTHEAST THROUGH NC. AS THESE
SURFACE WINDS SHIFT AROUND TO LIGHT FROM THE NE OR LIGHT/VRBL LATE
TONIGHT... A SHORT PERIOD OF IFR CIGS/VSBYS IS POSSIBLE AT ALL SITES
FROM 09Z-12Z.
LOOKING BEYOND 12Z FRI MORNING... THE FRONT WILL LIKELY SLOW DOWN
ENOUGH OVER SE NC TO KEEP A CHANCE OF SUB-VFR SHOWERS/STORMS AT FAY
THROUGH FRI AFTERNOON... BUT OTHERWISE VFR CONDITIONS ARE EXPECTED
FRI-SAT AS HIGH PRESSURE NOSES IN FROM THE NORTH. THIS FRONT WILL
SHIFT BACK NORTH AND DISSIPATE OVER THE WEEKEND WITH A SURFACE
TROUGH REFORMING OVER CENTRAL NC. AN UPPER LEVEL DISTURBANCE AND
ACCOMPANYING COLD FRONT WILL MOVE IN FROM THE NORTHWEST ON SUNDAY...
POTENTIALLY BRINGING ANOTHER ROUND OF SHOWERS/STORMS LATE SUNDAY
INTO MONDAY. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS..HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...HARTFIELD/MWS
LONG TERM...MWS
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
636 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 520 AM...LATEST WATER VAPOR IMAGES INDICATED THAT THE MID
LEVEL TROF WAS LOCATED GENERALLY OVER THE TN/NC LINE...WITH A S/W
OVER THE PIEDMONT. KGSP AND TCLT RADAR INDICATED SHOWERS AND
THUNDERSTORMS ASSOCIATED WITH EACH FEATURE. I WILL UPDATE THE
FORECAST TO INCREASE POPS ALONG AND EAST OF THE OBSERVED CONVECTION.
OTHERWISE...THE CURRENT FORECAST APPEARS IN GREAT SHAPE.
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AT KCLT...THE PRIMARY FORECAST CHALLENGE WILL BE THE TIMING OF
AFTERNOON TSRA. THE 4KM WRF AND 6Z NAM12 INDICATES THAT CONVECTION
WILL DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A
BAND. STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE
BAND TO MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING
ACROSS THE CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE
TSRA POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z. ALTHOUGH FROPA
SHOULD OCCUR BETWEEN 18Z-0Z...LIGHT NORTH WINDS ARE NOT FORECAST TO
DEVELOP UNTIL THIS EVENING. THE COMBINATION OF LIGHT NORTH
WINDS...LINGERING MID LEVEL CLOUD COVER...AND 2-3 DEGREE DEWPOINT
DEPRESSIONS SHOULD FAVOR VFR CONDITIONS TONIGHT.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE CONVECTION EITHER OVER THE
TERMINAL OR VICINITY THROUGH 0Z. I WILL HIGHLIGHT THE CONVECTIVE
PERIOD WITH VCTS OR TEMPO GROUPS...GENERALLY BETWEEN 19Z-22Z. AHEAD
OF THE COLD FRONT FLOW WILL REMAIN FROM THE SOUTHWEST BETWEEN
5-10KTS. WINDS WILL VEER FROM THE NORTH THIS EVENING. KAVL COULD SEE
NNW WINDS DEVELOP THIS MORNING...REMAINING THROUGH THE REST OF THE
12Z PACKAGE. NAM CONDENSATION PRESSURE DEFICITS AND MOS INDICATES
THAT KAVL COULD SEE IFR CEILINGS DURING THE PRE DAWN HOURS FRI.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
10-16Z 16-22Z 22-04Z 04-10Z
KCLT HIGH 98% HIGH 100% HIGH 100% HIGH 100%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAVL MED 65% HIGH 100% HIGH 92% MED 66%
KHKY HIGH 97% HIGH 100% HIGH 100% HIGH 100%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% HIGH 100%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...NED
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
647 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU JUL 24 2014
AN AREA OF SCATTERED THUNDERSTORMS WILL PUSH OUT OF THE KHON AREA
BY 13Z-14Z...AND MOVE TO IMPACT THE KFSD AND KSUX TAF SITE LATER
ON IN THE MORNING BETWEEN 13Z-17Z. A HEAVIER CORE IN STORMS WILL
LIKELY TAKE VISIBILITY TO MVFR...OTHERWISE VFR CONDITIONS ARE
EXPECTED WITH THE HIGH BASED STORMS. A FEW STORMS MAY ALSO PRODUCE
SOME SMALL HAIL. SURFACE SOUTHEAST TO SOUTH WINDS WILL INCREASE
AND WILL RESULT IN SOME STRONGER WIND GUSTS ABOVE 25 KNOTS DURING
THE MIDDAY AND AFTERNOON HOURS. IF WINDS DECOUPLE MORE THAN
EXPECTED TONIGHT...THERE COULD BE SOME LOW LEVEL WIND SHEAR FOR
KFSD OR KSUX. ANOTHER ELEMENT TO WATCH IS THE HIGH MOISTURE
CONTENT OF THE AIR...WHICH MAY ALSO LEAD TO A POTENTIAL FOR A
BRIEF PERIOD OF MVFR VISIBILITIES AROUND KSUX OF KFSD LATE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
748 AM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL ENTER THE REGION TODAY AND SHIFT SOUTHEAST OF
THE AREA BY LATE TONIGHT. HIGH PRESSURE OVER THE MIDWEST WILL
BUILD ACROSS THE MID ATLANTIC THROUGH FRIDAY. OVER THE WEEKEND THE
PATTERN SETS UP FOR POTENTIAL UPPER DISTURBANCES MOVING INTO THE
REGION ON A NORTHWEST FLOW. A STRONG FRONT IS EXPECTED TO CROSS
THE AREA MONDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 730 AM EDT THURSDAY...
FORECAST UPDATED TO ACCOUNT MORE COVERAGE IN THE PIEDMONT WITH
LESS IN THE WEST. STILL LOOKS LIKE FRONT AND MORE CONVECTION WILL
FIRE UP AND MOVE INTO THE WEST LATER THIS MORNING. CLOUD COVER
SHOULD HAMPER SEVERITY OF THE STORMS OVER THE MTNS BUT THE
POTENTIAL EXISTS FURTHER EAST FOR BREAKS IN THE OVC TO OCCUR TO
ALLOW FOR MORE TSRA DEVELOPMENT.
PREVIOUS DISCUSSION AT 330 AM...
A COUPLE OF SHORTWAVE TO DEAL WITH THROUGH THIS AFTERNOON. FIRST IS
OVER THE CENTRAL APPALACHIANS WITH MAIN BATCH OF SHRA AND ISOLATED
TSRA OCCURRING ALONG AND AHEAD OF IT. DESPITE INCREASING CIN AND
LIMITED INSTABILITY...HIGH THETA-E AND UPPER SUPPORT KEEPING SOME
STORMS ACROSS NW NC PIEDMONT INTO SOUTHSIDE VA. 4Z HRRR HANDLED THIS
PRETTY WELL...AND FOLLOWED SOME OF THIS INTO THE MORNING.
FRONTAL BOUNDARY LIES FROM NORTH OF CRW WEST TO SOUTH OF CVG AND
SOUTH TOWARD BNA THIS MORNING. SFC LOW ALONG THE FRONT OVER THE TN
VALLEY IS EXPECTED TO PUSH NORTHEAST INTO THE PIEDMONT OF VA BY MID
AFTERNOON AND SENDING THE FRONT WELL EAST OF THE MOUNTAINS BY THEN.
STILL UPPER SHORTWAVE THAT IS ACROSS IL THIS MORNING IS GOING TO
MOVE INTO THE MTNS THIS AFTERNOON AND WILL KEEP THREAT OF
SHOWERS/STORMS AROUND. BEST LIFT AND INSTABILITY THOUGH LOOKS TO
MOVE EAST OF THE MTNS THIS AFTERNOON. SPC HAS 5 PERCENT FOR DAMAGING
WINDS ACROSS MOST OF THE AREA TODAY. SOLAR INSOLATION MAY BE LIMITED
AS CLOUD COVER PER SAT TRENDS AND MODEL RH FORECASTS SUGGEST BKN-
OVC.
THE HIGHS TODAY WILL BE IMPACTED BY BOTH CLOUDS/CONVECTION BUT STILL
WARM WITH READINGS RANGING FROM THE MID 70S WEST TO MID 80S EAST.
TONIGHT...THE MAIN AXIS OF LIFT AND MOISTURE SHIFTS EAST OF AREA
WITH SKIES STARTING TO CLEAR IN THE WEST. WILL KEEP HIGH CHANCE
EARLY IN THE EAST THEN DRY IT OUT BY MIDNIGHT/EARLY OVERNIGHT...WHEN
MAIN TROUGH AXIS AT 5H SHIFTS ACROSS. LESS HUMID AIR WILL PUSH INTO
THE MOUNTAINS AT LEAST THOUGH PROXIMITY OF FRONT THAT STALLS OVER
ERN NC/SC MAY INHIBIT THE LOWER DEWPOINTS REACHING THE SE CWA
UNTIL FRIDAY. LOWS ARE GOING TO RANGE FROM THE MID 50S ACROSS THE
HIGHER MTNS TO MID 60S SOUTHEAST.
FRIDAY WILL BE DRY AND LESS HUMID WITH HIGH PRESSURE NOSING IN FROM
THE MID ATLANTIC TURNING WINDS AROUND MORE TO THE NE-E. HIGHS
RANGING FROM THE UPPER 70S MTNS TO LOWER 80S ROANOKE TO MID 80S EAST
CAN BE EXPECTED.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SATURDAY NIGHT/...
AS OF 350 AM EDT THURSDAY...
FOR SATURDAY...MOISTURE WILL BEGIN TO RETURN TO THE FORECAST AREA
FROM THE SOUTH AND SOUTHWEST. CAN`T RULE OUT A LATE AFTERNOON
POPUP SHOWER OVER THE MOUNTAINS...BUT THINK MOST AREAS WILL REMAIN
DRY UNTIL THE ARRIVAL OF A FRONT MONDAY. WILL HAVE TO MONITOR
THIS UPSTREAM FRONT CLOSELY AS IT MAY CAST SOME PREFRONTAL SHOWERS
AND STORMS OUR WAY AS EARLY AS SATURDAY NIGHT.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 515 PM EDT WEDNESDAY...
STRONG COLD FRONT IS SLATED TO CROSS THE FORECAST AREA LATE SUNDAY
INTO MONDAY...ASSOCIATED WITH A VIGOROUS SHORT WAVE TROUGH THAT
WILL BE MOVING ACROSS THE GREAT LAKES AND OHIO VALLEY. THIS
PARTICULARLY STRONG DISTURBANCE...NOTED BY ALL THE
MODELS...PROMISES TO AMPLIFY THE EASTERN LONG WAVE TROUGH...A
PATTERN THAT WILL NET COOLER THAN NORMAL TEMPERATURES FOR SEVERAL
DAYS NEXT WEEK.
DURING THE TRANSITION SUNDAY INTO MONDAY...INCREASED INSTABILITY
AHEAD OF THE FRONT ALONG WITH STRONG DYNAMIC FORCING WILL RESULT
IN POTENTIAL FOR STRONG TO SEVERE STORMS. THE OPPORTUNITY WILL
EXIST FOR ORGANIZED DEEP CONVECTION WITH POTENTIAL FOR A MESOSCALE
CONVECTIVE SYSTEM (MCS) TO CROSS THE FORECAST AREA FROM THE WEST.
ATTM WILL MAINTAIN THE BEST CHANCE FOR SHOWERS/STORMS SUNDAY...WITH
THE THREAT LINGERING INTO MONDAY UNTIL THE SURFACE FRONT CAN
COMPLETELY CLEAR THE FORECAST AREA. GENERALLY FOLLOWED HPC
GUIDANCE THROUGH THE PERIOD TRENDING POPS DOWNWARD AFTER THE EARLY
WEEK FROPA.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 735 AM EDT THURSDAY...
MOISTURE IN THE LOW LVLS PLUS ADDED RAINFALL HAS ALLOWED FOR FOG
AT A FEW LOCATIONS THIS MORNING. HOWEVER EXPECT THIS TO BE SHORT
LIVED. SHOWERS ARE GOING TO BRING TEMP MVFR VSBYS TO DAN TO START
THE TERMINALS.
HIGH-RES MODELS FAVOR MORE CONVECTION MOVING OUT OF WV INTO VA
AREA BY MIDDAY...WITH BEST CHANCE IN THE ROA/LYH/DAN CORRIDOR.
THIS AFTERNOON. KEPT VCTS IN BUT HAVE ENOUGH CONFIDENCE IN THE
HIGH RES MODELS OVERALL TO ADD TEMPO THUNDER IN AT LYH/DAN LATER
THIS AFTERNOON. LOOK FOR CIGS TO BE MVFR IN THE MTNS EARLY BEFORE
BECOMING VFR BY MIDDAY/18Z.
CONVECTION WILL EXIT THE MOUNTAINS BY 21-22Z AND DAN/LYH BY 00Z.
TONIGHT WILL BE TRICKY AS DRY AIR MAY BE SLOW TO ARRIVE IN
EARNEST. DEPENDING ON HOW MUCH RAIN OCCURS AND WITH CLEARING THINK
FOG WILL BECOME AN ISSUE AT MOST SITES. THINK LWB/BCB WILL HAVE
DENSE FOG AT LEAST BEFORE THE DRY AIR ARRIVES.
EXTENDED AVIATION DISCUSSION...
AIRMASS WILL DRY OUT BEHIND THE FRONT GOING INTO FRIDAY-
SATURDAY. VFR FRI- SAT OUTSIDE OF ANY VALLEY FOG AT KLWB/KBCB
EACH MORNING. ANOTHER FRONT AND ASSOCIATED UPPER IMPULSES COULD
BRING A GOOD THREAT OF STORMS IN THE SUN-MON TIME FRAME. DURING
THIS TIME MAINLY VFR...EXCEPT IN TSRA AND FOR ANY LATE NIGHT FOG.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...WP
NEAR TERM...WP
SHORT TERM...PM/WP
LONG TERM...PM
AVIATION...WP
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
151 PM EDT THU JUL 24 2014
.PREV DISCUSSION... /ISSUED 1132 AM EDT THU JUL 24 2014/
UPDATE...
HAVE GONE THROUGH AND REDUCED POPS THIS MORNING BUT HAVE PRETTY
MUCH LEFT AFTERNOON TRENDS ALONE WITH THE APPROACH OF THE COLD
FRONT EXPECTED TO TRIGGER SHOWERS AND THUNDERSTORMS. HRRR HAS BEEN
PRETTY STEADFAST IN DEVELOPING CONVECTION ACROSS NORTH GEORGIA
AROUND 18Z THOUGH SOME OTHER HIRES MODELS DID START BACKING OFF ON
CONVECTION WITH OVERNIGHT RUNS. TEMPERATURES IN PRETTY GOOD SHAPE
BUT DEWPOINTS ARE RUNNING HIGHER THAN FORECAST SO HAVE MADE SOME
TWEAKS THERE. ALL IN ALL...NOT ENOUGH CHANGE TO WARRANT AN UPDATE
TO ZONE PRODUCTS.
TDP
PREV DISCUSSION... /ISSUED 732 AM EDT THU JUL 24 2014/
SHORT TERM /TODAY THROUGH FRIDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
A COLD FRONT CURRENTLY ACROSS NORTH TN IS PROGGD BY MODELS TO SAG
SOUTHWARD TODAY. ALTHOUGH THE NAM IS SLIGHTLY SLOWER THAN THE GFS...
A BLEND IN TIMING WOULD PUSH THE FRONT INTO NORTH GA BY LATE THIS
MORNING... THEN ACROSS THE ATLANTA METRO AROUND LATE AFTERNOON OR
EARLY EVENING. THE NAM STALLS THE FRONT NEAR OR JUST NORTH OF
ATLANTA THIS EVENING... BUT EXPECT THE DEVELOPING MID TO UPPER NW
FLOW ALOFT TO BE SUFFICIENT TO PUSH THE FRONT SOUTH OF ATLANTA
TONIGHT AS THE GFS INDICATES. EITHER WAY...THE GREATER CHANCES FOR
SHOWERS AND THUNDERSTORMS WILL BE DURING DAYTIME HEATING TODAY AS
WEAK DISTURBANCES TRAVERSE THROUGH THE UPPER TROUGH AND HELP SPARK
CONVECTION ALONG AND AHEAD OF THE SLOW MOVING FRONT. WITH SOME
UNCERTAINTY OF THE FRONTS LOCATION TONIGHT... WILL SHOW A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR ATLANTA AND AREAS SOUTHWARD
THROUGH MIDNIGHT... THEN SHIFT THIS POTENTIAL MAINLY SOUTH OF
ATLANTA AFTER MIDNIGHT. EXPECT A SLIGHTLY DRIER/COOLER AIR MASS TO
FILTER INTO NORTH GA TONIGHT AND POSSIBLY HANG AROUND ON FRIDAY...
BUT MODELS ARE HINTING AT THE FRONT DRIFTING BACK INTO NORTH GA
FRIDAY AFTERNOON. THIS WILL WARRANT HOLDING ONTO AT LEAST A SLIGHT
CHANCE OF SHOWERS AND THUNDERSTORMS FOR AREAS FROM ATLANTA SOUTHWARD
ON FRIDAY.
ALTHOUGH CANNOT RULE OUT AN ISOLATED STRONG OR SEVERE STORM THIS
AFTERNOON WITH MODERATE CAPE VALUES IN THE 2000-2500 J/KG RANGE...
EXPECT THIS THREAT TO BE MINIMAL AS WIND SHEAR AND FRONTAL FORCING
WILL BE WEAK. SPC IS SHOWING ONLY A GENERAL THUNDER OUTLOOK FOR THE
AREA THROUGH FRIDAY... AND THIS LOOKS REASONABLE EACH DAY.
WIDESPREAD RAINFALL AMOUNTS SHOULD AVERAGE AROUND ONE HALF INCH OR
LESS... WITH SOME ISOLATED SLIGHTLY HIGHER AMOUNTS POSSIBLE.
THEREFORE... FLOOD PROBLEMS ARE NOT EXPECTED AT THIS TIME.
AS FOR TEMPS...CLOUDS AND PRECIP SHOULD HELP HOLD HIGHS DOWN IN THE
LOWER TO MID 80S ACROSS MAINLY NORTH GA TODAY WHILE CENTRAL GA HEATS
UP INTO THE UPPER 80S TO LOWER 90S. EXPECTING SLIGHTLY COOLER LOWS
MOSTLY IN THE 60S FOR MUCH OF NORTH GA TONIGHT BEHIND THE FRONT. THE
COOLER TEMPS ARE SHORT-LIVED AS HIGHS CLIMB BACK INTO THE UPPER 80S
TO LOWER 90S FOR MOST AREAS ON FRIDAY. A MAV AND MET BLEND WITH SOME
TWEAKS LOOKED REASONABLE THROUGH THE SHORT TERM.
39
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
/ISSUED AT 456 AM EDT THU JUL 24 2014/
MODELS CONTINUE TO SHOW A FEW UPPER LEVEL DISTURBANCES TO
TRAVERSE THE REGION OVER THE WEEKEND. SURFACE HIGH SHOULD KEEP
POPS TO A MINIMUM SATURDAY...AND WITH FRONT APPROACHING THE AREA
SUNDAY...HIGH WILL LOSE CONTROL OF THE AREA AND ALLOW FOR
INCREASING RAIN CHANCES. EXTENDED PERIODS ARE STILL LARGELY
DOMINATED BY THIS STRONG COLD FRONT /ANOMALOUS FOR LATE JULY/ AND
MODELS AGREE WITH PUSHING IT THROUGH NORTH AND CENTRAL GEORGIA BY
LATE MONDAY. DEEP LONGWAVE TROUGH REMAINS POSITIONED OVER THE AREA
THROUGH MUCH OF NEXT WEEK...KEEPING LOWER DEW POINTS AND COOLER
TEMPERATURES IN PLACE IN THE WAKE OF THE COLD FRONT. SOME MOISTURE
DOES LOOK TO CREEP BACK NORTHWARD AS BOUNDARY REMAINS OVER SOUTH
GEORGIA...AND HAVE GENERALLY INCLUDED SLIGHT CHANCE POPS IN THE FAR
SOUTHERN PORTIONS OF THE CWA THROUGH WEDNESDAY. BEGINNING
TUESDAY...SHOULD SEE BELOW AVERAGE TEMPERATURES WITH HIGHS IN THE
UPPER 70S NORTH AND LOW 80S ELSEWHERE...AND LOWS IN THE 60S.
STRONG TO SEVERE STORMS MAY ACCOMPANY THE FRONT AS IT PUSHES
THROUGH THE AREA MONDAY WITH MODELS CONTINUING TO ADVERTISE A
COMBINATION OF DECENT SHEAR AND INSTABILITY. WITH SOME UNCERTAINTY
IN THE FORECAST MODELS REGARDING THE TIMING OF THIS SYSTEM...THE
SEVERE POTENTIAL WILL NEED TO CONTINUE TO BE MONITORED.
31
&&
.AVIATION...
18Z UPDATE...
SHRA AND TSRA INCREASING W/ A LINE OF CONVECTION ACROSS THE METRO
ATLANTA AREA. HAVE KEPT TEMPO GROUP TO COVER. OTHERWISE JUST VCSH
THROUGH ABOUT 02Z NORTH AND 04Z SOUTH WITH A DECREASE IN CLOUD
COVER THEREAFTER. SOME HINTS AT IFR CIGS AT CSG BUT THINK THAT
COVERAGE WOULD BE SCT AT BEST BUT WILL REEVALUATE. MVFR FOG
EXPECTED AT MOST SITES FRIDAY MORNING. WINDS GENERALLY W TO NW
THROUGH THE PERIOD WITH LOW-END GUSTS THIS AFTERNOON...NEARLY CALM
OVERNIGHT NIGHT.
//ATL CONFIDENCE...18Z UPDATE...
MEDIUM ON TIMING OF DIMINISHING CONVECTION.
HIGH ON ALL OTHER ELEMENTS.
TDP
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 90 69 89 69 / 60 30 10 5
ATLANTA 87 70 88 72 / 60 30 10 5
BLAIRSVILLE 82 61 83 61 / 60 20 10 5
CARTERSVILLE 87 68 88 68 / 60 20 5 5
COLUMBUS 89 73 90 74 / 60 30 30 5
GAINESVILLE 86 69 87 69 / 60 30 10 5
MACON 90 71 92 72 / 50 30 30 10
ROME 86 68 88 67 / 60 20 5 0
PEACHTREE CITY 88 69 88 69 / 60 40 20 5
VIDALIA 92 73 92 74 / 30 30 30 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1200 PM MDT THU JUL 24 2014
.UPDATE...
ISSUED AT 924 AM MDT THU JUL 24 2014
CURRENT NEAR TERM FORECAST CONCERNS FOCUS ON HOW WARM THINGS WILL
GET THIS AFTERNOON COMBINED WITH MAGNITUDE OF DEWPOINT FALLS AS
DRYLINE DEVELOPS THIS AFTERNOON.
LATEST RAP AND HRRR AND TO A LESSER DEGREE THE NAM ARE SUPPORTING
A WELL MIXED VERY WARM PATTERN ACROSS THE CWA PUSHING HIGHS ABOVE
105 IN SEVERAL LOCATIONS. NOT TOTALLY SOLD ON THIS AS MODELS ARE
AGGRESSIVELY MIXING THINGS FASTER THAN CURRENT OBSERVATIONS. GOES
SOUNDER DATA DOES INDICATE AN AREA OF LOW PW`S NOSING INTO THE
WESTERN CWA AS OF 14Z...WHICH WOULD SUPPORT A LAYER OF DRIER AIR
OFF OF THE SURFACE WHICH COULD POTENTIALLY DILUTE SFC TDS THIS
AFTERNOON. HAVE LOWERED BOTH THE TD AND RAISED TEMPS A FEW DEGREES
BASED ON LATEST DATA AND WILL CLOSELY MONITOR TRENDS TO SEE IF
MUCH WARMER TEMPS ARE NEEDED.
GIVEN DRY AIR AND INCREASING SOUTHWESTERLY WINDS...FIRE WX MAY
BECOME A LARGE CONCERN THIS AFTERNOON ESPECIALLY NEAR RECENTLY
HARVESTED OR READY FOR HARVEST WHEAT FIELDS. CURRENTLY WIDESPREAD
CRITICAL FUELS ARE IN QUESTION THOUGH SO NOT SURE A RFW IS VALID
AT THIS POINT IN THE GREEN UP CYCLE. FOR THE TIME BEING...PLAN ON
HIGHLIGHTING POTENTIALLY CRITICAL LOCAL FIRE DANGER IN SPS FOR NOW
UNTIL FUEL INFORMATION BECOMES MORE APPARENT.
UPDATE ISSUED AT 630 AM MDT THU JUL 24 2014
SMALL AREA OF LOW STRATUS AND MINOR FOG HAS DEVELOPED TO THE EAST
OF SURFACE TROUGH STRETCHING FROM GARDEN CITY TO RUSSEL SPRINGS.
THIS IS NOT A PARTICULARLY WIDE AREA AND THINK MORNING SUN SHOULD
HELP MIX OUT FOG AND LOWER CLOUDS FAIRLY QUICKLY.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY NIGHT)
ISSUED AT 324 AM MDT THU JUL 24 2014
FORECAST PROBLEMS WILL BE CHANCES OF PRECIPITATION AND HOW HOT DOES
IT GET. SATELLITE SHOWING AN AMPLIFIED PATTERN FROM THE EASTERN
PACIFIC INTO THE WESTERN ATLANTIC. STRONG RIDGE CENTERED TO OUR
SOUTHWEST IS STARTING TO BE PUSHED SOUTH BY A STRONG UPPER SYSTEM
THAT IS NOW MOVING INTO THE PACIFIC NORTHWEST. STALLED FRONTAL
BOUNDARY IS NEAR THE WESTERN END OF OUR AREA.
AT MID LEVELS...MODELS TENDED TO BE A LITTLE TOO FAR EAST...
ESPECIALLY WITH THE PACIFIC NORTHWEST SYSTEM. OVERALL THE ECMWF WAS
DOING A LITTLE BETTER THAN THE GFS AND UKMET. AT LOW LEVELS...THE
ECMWF AND SREF WERE DOING THE BEST. THE ECMWF WAS DOING A LITTLE
BETTER ON THE LOW LEVEL THERMAL FIELD.
TODAY/TONIGHT...SURFACE TROUGH AND SHORTWAVE TROUGH MOVE INTO THE
WESTERN PORTION OF THE FORECAST AREA LATER THIS AFTERNOON. THERE IS
A DEEP DRY LAYER SHOWN BY THE MODEL SOUNDINGS WITH 700 MB
TEMPERATURES GREATER THAN +15. WILL KEEP A SLIGHT CHANCE OF
PRECIPITATION BUT PULL THE SLIGHT CHANCE BACK FURTHER WEST TOWARD
THE LIFT. THIS ALSO MATCHES WITH GEFS PROBABILITIES. NEW GUIDANCE
SUPPORTED ONLY MAKING SLIGHT ADJUSTMENTS TO THE HIGH TEMPERATURES.
QUESTION THEN BECOMES HOW FAR EAST DOES IT GO DURING THE NIGHT.
INITIALLY MOST OF THE LIFT ALOFT GOES ACROSS THE NORTHWEST HALF
DURING THE EVENING. HOWEVER...THE SURFACE TROUGH AND REMAINDER OF THE
SHORTWAVE GOES ACROSS DURING THE NIGHT. SINCE LIFT DOES NOT LOOK THAT
STRONG RIGHT NOW AND THERE IS A DEEP DRY LAYER WILL CONTINUE WHAT THE
DAY SHIFT PUT IN WHICH IS THE SLIGHT CHANCE ACROSS THE NORTHWEST HALF
DURING THE EVENING. THIS ALSO MATCHES WITH THE PROBABILITY FORECAST
WHICH DOES KEEP MEASURABLE A LITTLE FURTHER WEST AS WELL.
FRIDAY/FRIDAY NIGHT...MODELS NOW APPEAR A LITTLE SLOWER WITH THE
COLD FRONT...BEING PUSHED BY NORTHERN SYSTEM. IN FACT MOST OF THEM
STALL THE FRONT OVER THE CENTRAL/SOUTHEAST PORTION BY LATE IN THE
AFTERNOON. THIS THEN LOOKS TO PULL BACK TO THE NORTH DURING THE
EVENING BEFORE COMING THROUGH IN THE LATER HALF OF THE NIGHT.
ALSO A WEAKER SHORTWAVE WILL MOVE ACROSS WHERE THE FRONT WILL BE IN
THE AFTERNOON. AFTER THAT A MUCH STRONGER SHORTWAVE MOVES IN FROM
THE WEST DURING THE NIGHT. COMPLICATE THAT WITH 700 MB TEMPERATURES
NEAR OR ABOVE PLUS 15 AND A DEEP DRY LAYER IN THE BOTTOM HALF OF
THE ATMOSPHERE. STORM MOTIONS WILL BE VERY SLOW AS WELL. SO COULD
POSSIBLY HAVE THUNDERSTORMS DEVELOP NEAR/JUST WEST OF THE BOUNDARY
AND/OR COME OFF THE HIGHER TERRAIN TO THE WEST DUE TO THE SHORTWAVE
AND SOME UPSLOPE FLOW. WILL PUT SOME SLIGHT CHANCE POPS WITH THE
FRONT IN THE AFTERNOON.
QUESTION ONCE AGAIN IS HOW FAR EAST DOES THE CONVECTION GO AND HOW
LONG IT GOES INTO THE NIGHT. MODEL QPF AND PROBABILITY FORECASTS
TEND TO FAVOR THE WESTERN PORTION OF THE AREA AND TO OUR NORTH. RIGHT
THE CURRENT FORECAST IN THE EVENING LOOKS REASONABLE AND ONLY MADE A
SLIGHT ADJUSTMENT. HOWEVER WITH THE BOUNDARY AND DECENT LIFT MOVING
THROUGH IN THE LATTER HALF OF THE NIGHT...WILL INSERT A SLIGHT CHANCE
IN THE SOUTHEAST HALF.
HIGH TEMPERATURES WILL BE INTERESTING DEPENDING ON THE SPEED AND
POSITION OF THE FRONT. SINCE MODELS ARE SLOWER WITH THE FRONT...
MODEL TEMPERATURES ARE WARMER THAN THEY WERE YESTERDAY...ESPECIALLY
IN THE SOUTHEAST PORTION OF THE AREA. SO ENDED UP RAISING MAXES...
ESPECIALLY IN THE SOUTHEAST HALF.
SATURDAY/SATURDAY NIGHT...AT THIS TIME IT LOOKS LIKE THE FRONT IS
THROUGH THE ENTIRE AREA...NOT BY MUCH...BY EARLY AFTERNOON. SO AIR
MASS WILL BE COOLER WITH SOME WEAK UPSLOPE OCCURRING. THIS FRONT
CONTINUES TO MOVE SOUTH AND EAST THROUGH THE NIGHT. WITH THE FRONT
THROUGH THE AREA BELIEVE INITIALLY THAT THE PRECIPITATION WILL BE
TIED TO IT WITH THE MAIN AREA SOUTH AND EAST OF THE FORECAST AREA.
IT WILL BE POSSIBLE THAT THE FAR WEST WILL SEE SOME STORMS WITH THE
NEXT SHORTWAVE TROUGH APPROACHING THE POST FRONTAL UPSLOPE AIR
MASS. SO REDUCED POPS TO JUST THAT AREA IN THE AFTERNOON.
SHORTWAVE TROUGH MOVING THROUGH DURING THE NIGHT. BUT MODELS
DISAGREE ON WHERE THE BEST LIFT AND HOW MUCH INSTABILITY WILL BE
PRESENT. OVERALL SETUP AND PROBABILITIES SUPPORT THE SOUTHWEST HALF
OF THE FORECAST AREA AT THIS TIME. SO LEFT THE CURRENT FORECAST
ALONE.
EVEN THOUGH MOST OF THE AREA IS BEHIND THE FRONT BY SHORTLY AFTER
18Z...MODELS DISAGREE ON HOW MUCH COOLER AIR TO BRING INTO THE
AREA. ONCE AGAIN THE FURTHER NORTH AND WEST YOU GO...THE LESS HOT IT
WILL BE. AGAIN THE SOUTHEAST WILL SEE THE HOTTEST TEMPERATURES.
MADE ONLY MINOR ADJUSTMENTS TO ONGOING FORECAST.
.LONG TERM...(SUNDAY THROUGH WEDNESDAY)
ISSUED AT 150 AM MDT THU JUL 24 2014
FOR THE EXTENDED PERIOD...REGION WILL SEE PATTERN SHIFT AS MODELS
BEGIN TO STRENGTHEN H5/H7 RIDGES OVER THE WESTERN PORTIONS OF THE
COUNTRY...COUNTERACTED WITH A DEEPENING TROUGH/UPPER LOW SETTING UP
OVER THE GREAT LAKES/NORTHEAST REGIONS. UPPER FLOW AS A RESULT WILL
BE NORTHWEST OVER THE AREA FOR THE ENTIRE EXTENDED TIME FRAME. AT
THE SURFACE...A SERIES OF WEAK WAVES WILL MOVE OFF THE EASTERN
PORTION OF THE ROCKIES FOR SUNDAY INTO MONDAY NIGHT...FOLLOWED BY A
STRONGER LEE-SIDE TROUGH THAT SETS UP ON TUESDAY...SETTLING SOUTH OF
REGION EARLY WEDNESDAY AND THEN CONVERTING TO INVERTED TROUGH AND
MEANDER OF THE REGION THROUGH WEDNESDAY. THE RESULT OF THE SYNOPTIC
SETUP WILL BRING CHANCE FOR TRW/RW ALMOST EVERY DAY WITH BEST
CHANCES BEING TUESDAY INTO WEDNESDAY AND THIS IS WHERE HIGHEST POPS
(30-40) ARE HIGHLIGHTED...BEFORE THINGS WIND DOWN WEDNESDAY NIGHT
INTO THURSDAY. AS A RESULT OF THE BROAD NW UPPER FLOW AND EXPECTED
CLOUD COVER...TEMPERATURES WILL BE GENERALLY A FEW DEGREES BELOW
NORMAL WITH HIGHS IN THE 80S TO LOW 90S IN SPOTS. OVERNIGHT LOWS WILL
RANGE IN THE LOW/MID 60S AND WILL BE HAMPERED AT TIMES IF ANY
RESIDUAL CLOUDS REMAIN FROM CONVECTION DURING THE AFTERNOON/EVENING
HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1158 AM MDT THU JUL 24 2014
VFR CONDITIONS EXPECTED FOR THE NEXT 24 HOURS WITH GUSTY SOUTHERLY
WINDS EXPECTED THROUGH SUNSET...WITH WINDS AT MCK INCREASING BY
20Z. COLD FRONT WILL SLIDE THROUGH AREA AFTER 13Z...BRINGING A
PERIOD OF GUSTY NORTHERLY WINDS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JRM
SHORT TERM...BULLER
LONG TERM...JN
AVIATION...JRM
AREA FORECAST DISCUSSION
NWS TOPEKA KS
1231 PM CDT Thu Jul 24 2014
...Update to aviation forecast discussion...
.SHORT TERM...(Today and Tonight)
Issued at 349 AM CDT THU JUL 24 2014
Water vapor imagery this morning showed the broad mid-level ridge
still anchored across the Rockies, resulting in northwesterly aloft
across the forecast area. A few weak embedded shortwaves were noted
along the northern edge of the ridge axis over South Dakota. While
these waves should progress southeastward along the ridge axis, most
models show any precipitation that develops from these waves to
remain north of the forecast area. It`s worth noting though that
recent early morning runs of the HRRR and RAP have started to show
precipitation from these shortwaves diving further south along the
Nebraska/Iowa border and skimming near far northeast Kansas by this
afternoon. However, due to the agreement of the synoptic models in
keeping precipitation north of the area and with the fairly poor
performance of these short-range models over the last few days, have
gone with a dry forecast for today but will continue to monitor
these shortwaves through the day.
Surface high pressure was situated over the region early this
morning, resulting in light winds, mostly clear skies, and cooler
conditions as temperatures dropped into the 60s. This surface high
gradually will shift eastward toward the Ohio River Valley, with
winds shifting to the southeast today and further to the south
overnight. These southeasterly winds today will keep temperatures
near or slightly below the seasonal normals as afternoon highs
should reach into the mid 80s east to low 90s west.
Water vapor imagery showed a mid-level trough and closed-off low
moving onshore in the Pacific Northwest, and models show this low
progressing eastward along the U.S./Canadian border over the next
few days. This advancing low will help to flatten the mid-level
ridge currently in place, resulting in the area of surface low
pressure currently over the northern Rockies being pushed southward
into the High Plains tonight. Model soundings show high clouds
building in over the region tonight, so this cloud cover combined
with southerly winds will result in better insolation and keep low
temperatures tonight a few degrees warmer in the upper 60s to mid
70s.
.LONG TERM...(Friday through Wednesday)
Issued at 349 AM CDT THU JUL 24 2014
Friday, the upper level ridge builds into northeast Kansas with the
edge of the westerlies over Missouri and Iowa. Thermal axis will
develop across the Central Plains ahead of a surface trough/front
that is expected to slowly move across Nebraska and into north
central Kansas by Friday evening. Dew point temperatures in the
middle 60s in north central Kansas and near 70 in northeast Kansas
will combine with afternoon temperatures from the upper 90s in far
eastern counties to around 105 toward central Kansas to produce
afternoon heat indices of 104 to 109 and will likely need a heat
advisory for the day on Friday.
The frontal boundary will slowly move south Saturday and Saturday
night settling in southern Kansas by Sunday morning as the upper
level ridge is suppressed westward as an upper level trough moves
across southern Canada and the Northern Plains. A unstable airmass
develops across northern Kansas Saturday with CAPE of 2500-5000 J/kg
and moderate shear. Soundings show inverted V cap eroding by late
afternoon and could see some isolated thunderstorms developing. If
they do develop then damaging wind gusts will be the main hazard.
Saturday will be a little cooler than Friday due to the presence of
mid and upper level clouds. However temperatures will range from
the lower 90s along the Nebraska border to around 101 near central
Kansas. Dew points in the upper 60s to around 70 will combine with
the temperatures to produce heat indices of 99 to 104.
Cooler temperatures and dry weather are expected on Sunday in the
wake of the front and this should continue into mid week with
northwest flow aloft and high pressure over much of the Central
Plains. The next chance of precipitation comes Tuesday night and
Wednesday with the western counties having the best chances. Both
the GFS and ECMWF indicate mid level waves moving through the
northwest flow.
&&
.AVIATION...(For the 18Z TAFs through 18Z Friday Afternoon)
Issued at 1223 PM CDT THU JUL 24 2014
VFR prevails for KTOP/KMHK/KFOE as southeasterly winds above 10
kts through the afternoon may only fall just below 10 kts
overnight as a deepening surface trough shifts eastward. Winds
veer to the south 08-10Z as winds increase between 10 and 13 kts
sustained. Higher speeds with gusts are possible near the end of
the period.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Hennecke
LONG TERM...53
AVIATION...Bowen
AREA FORECAST DISCUSSION
NWS JACKSON KY
143 PM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1235 PM EDT THU JUL 24 2014
SHOWERS HAVE FILLED IN OVER SOUTHEAST KENTUCKY A LITTLE MORE THAN
PREVIOUSLY FORECAST SO INCREASED POPS FOR A COUPLE HOURS BUT KEPT
WITH THE IDEA OF A DIMINISHING TREND IN THE SHOWER ACTIVITY FROM
WEST TO EAST THROUGH THE AFTERNOON AS THE RESPONSIBLE AREA OF LOW
PRESSURE PUSHES EAST. THIS TREND APPEARS LIKE IT WILL RESULT IN ALL
OF THE SHOWER ACTIVITY SHIFTING EAST OF OUR FORECAST AREA BY 00Z AND
REMOVED ALL MENTION OF PRECIP FOR TONIGHT.
NEXT BIG QUANDARY IS HOW MUCH CLOUD COVER WILL HANG IN PLACE TONIGHT
OR HOW MUCH FOG WILL DEVELOP SHOULD SKIES CLEAR. 12Z NAM INDICATES
THE POTENTIAL FOR CONSIDERABLE LOW CLOUDS TO HANG IN THROUGH THE
NIGHT WHILE OTHER MODELS SHOW THE LOW CLOUDS DISSIPATING. WITH LOW
LEVEL FLOW VEERING AROUND TO A NORTHEASTERLY DIRECTION THROUGH THE
NIGHT...WOULD TEND TO LEAN TOWARD THE NAM SOLUTION WITH MORE LOW
CLOUDS AND LESS FOG.
UPDATE ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM EDT THU JUL 24 2014
DIFFICULT AVIATION FORECAST WITH LOW CONFIDENCE IN DETAILS AT THIS
TIME. LOW CLOUDS CURRENTLY IN PLACE WILL SLOWLY LIFT AND ERODE
AROUND THE WESTERN AND NORTHERN EDGES THROUGH THE AFTERNOON AS LOW
PRESSURE TRACKS OUT OF FAR EAST KENTUCKY INTO THE VIRGINIAS. DRIER
AIR WILL WORK INTO THE REGION ON NORTHERLY WINDS AND RESIDUAL SHOWER
ACTIVITY OVER FAR SOUTHEAST KENTUCKY WILL END BY EVENING. LOW LEVEL
FLOW WILL VEER AROUND TO A NORTHEASTERLY DIRECTION WITH TIME
OVERNIGHT. THIS TYPICALLY RESULTS IN A TENDENCY FOR LOW CLOUDS TO
HANG IN TOUGH OVER EASTERN KENTUCKY...OR REDEVELOP IF THEY BREAK UP
FOR A TIME DURING THE EVENING. SO...WHILE FLIGHT CONDITIONS WILL
GRADUALLY IMPROVE THIS AFTERNOON AND EVENING...IT IS LIKELY THEY
WILL DETERIORATE AGAIN AFTER MIDNIGHT WITH A PROLONGED PERIOD OF
LIFR OR LOWER CONDITIONS LIKELY AROUND DAWN ON FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...ABE
AREA FORECAST DISCUSSION
NWS JACKSON KY
1235 PM EDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1235 PM EDT THU JUL 24 2014
SHOWERS HAVE FILLED IN OVER SOUTHEAST KENTUCKY A LITTLE MORE THAN
PREVIOUSLY FORECAST SO INCREASED POPS FOR A COUPLE HOURS BUT KEPT
WITH THE IDEA OF A DIMINISHING TREND IN THE SHOWER ACTIVITY FROM
WEST TO EAST THROUGH THE AFTERNOON AS THE RESPONSIBLE AREA OF LOW
PRESSURE PUSHES EAST. THIS TREND APPEARS LIKE IT WILL RESULT IN ALL
OF THE SHOWER ACTIVITY SHIFTING EAST OF OUR FORECAST AREA BY 00Z AND
REMOVED ALL MENTION OF PRECIP FOR TONIGHT.
NEXT BIG QUANDRY IS HOW MUCH CLOUD COVER WILL HANG IN PLACE TONIGHT
OR HOW MUCH FOG WILL DEVELOP SHOULD SKIES CLEAR. 12Z NAM INDICATES
THE POTENTIAL FOR CONSIDERABLE LOW CLOUDS TO HANG IN THROUGH THE
NIGHT WHILE OTHER MODELS SHOW THE LOW CLOUDS DISSIPATING. WITH LOW
LEVEL FLOW VEERING AROUND TO A NORTHEASTERLY DIRECTION THROUGH THE
NIGHT...WOULD TEND TO LEAN TOWARD THE NAM SOLUTION WITH MORE LOW
CLOUDS AND LESS FOG.
UPDATE ISSUED AT 1107 AM EDT THU JUL 24 2014
WEAK LOW PRESSURE IS TRACKING SLOWLY ACROSS SOUTHEAST KENTUCKY WITH
NORTHERLY WINDS STARTING TO PULL DRIER AIR INTO OUR NORTHERN
COUNTIES. SCATTERED SHOWERS CONTINUE TO PLAGUE AREAS SOUTH OF I-64
ALONG WITH AN OCCASIONAL ISOLATED THUNDERSTORM. THESE WILL GRADUALLY
PULL EAST AS THE LOW PRESSURE DEPARTS TO THE EAST DURING THE
AFTERNOON WITH DECREASING RAIN CHANCES EXPECTED FROM WEST TO EAST
THROUGH THE AFTERNOON. CLOUD COVER WILL LIKELY HANG IN TOUGH THROUGH
MOST OF THE DAY WITH CU DEVELOPING QUICKLY WHERE ANY BREAKS DEVELOP
DURING THE AFTERNOON.
UPDATE ISSUED AT 540 AM EDT THU JUL 24 2014
UPDATED THE FORECAST TO ADD AREAS OF DENSE FOG INTO THE GRIDS FOR
THIS MORNING GIVEN THE OBSERVATIONS AND WEB CAMS. THE LIGHT WINDS AND
MOIST BOUNDARY LAYER IS RESULTING IN NUMEROUS PLACES WITH VISIBILITY
BELOW A QUARTER OF A MILE. THE FOG SHOULD START TO BREAK UP BY 8 AM.
ALSO FINE TUNED THE T AND TD GRIDS PER THE LATEST OBS AND TRENDS. THE
GRIDS...AN SPS...UPDATED ZONES...AND HWO HAVE BEEN ISSUED.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 325 AM EDT THU JUL 24 2014
06Z SFC ANALYSIS SHOWS A WEAK AREA OF LOW PRESSURE OVER EAST KENTUCKY
ALONG A COLD FRONT THAT IS GRADUALLY SETTLING THROUGH THE CWA. THIS
BOUNDARY AND LOW IS RESPONSIBLE FOR THE SHOWERS AND STORMS WE SAW
EARLIER IN THE EVENING AND THE ONES THAT STILL LINGER OVER NORTH
CENTRAL KENTUCKY. NORTHWEST OF THIS FRONT...A COOL AND DRY AREA OF
HIGH PRESSURE IS IN PLACE OVER THE MIDWEST ON FINAL APPROACH TO EAST
KENTUCKY...SCHEDULED TO ARRIVE BY THURSDAY EVENING. MEANWHILE...
SCATTERED SHOWERS AND STORMS WILL REMAIN A THREAT THROUGH THE REST OF
THE MORNING AND INTO THE START OF THURSDAY. PATCHY FOG AND PLENTY OF
LOW CLOUDS ARE FOUND THROUGH EAST KENTUCKY AT THE MOMENT...AS WELL.
THIS ALL IS EXPECTED TO LINGER THROUGH SUNRISE AS TEMPERATURES AND
DEWPOINTS STAY ABOUT WHERE THEY ARE CURRENTLY...IN THE UPPER 60S AND
LOWER 70S. SIMILARLY...THE WINDS WILL REMAIN LIGHT AND VARIABLE WELL
INTO THE DAY THURSDAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM AS THEY
ALL SHIFT THE EASTERN TROUGH SLIGHTLY NORTHEAST IN RESPONSE TO A
FLATTENING OF THE STRONG WESTERN RIDGE. LEADING OFF THIS TRANSITION
ARE A COUPLE OF SHORTWAVES THAT WILL CROSS THE SOUTHERN OHIO VALLEY
AND KENTUCKY INTO THE AFTERNOON THURSDAY. RISING HEIGHTS WILL FOLLOW
LATER TONIGHT AND THROUGH THE DAY FRIDAY HELPING TO KEEP ANY ENERGY
PACKETS IN THE NORTHWEST FLOW FROM AMOUNTING TO MUCH OVER OUR AREA.
WITH THE MODEL AGREEMENT HAVE FAVORED THE HRRR AND NAM12 SOLUTIONS
FOR THE FORECAST TODAY AND THEN A GENERAL MODEL BLEND INTO FRIDAY. OF
NOTE...BOTH THE NAM12 AND THE ECMWF DO MAKE MORE OUT OF A BAND OF
PCPN THAT THEY FORECAST TO ACCOMPANY THE COLD FRONT AS IT EXITS LATER
TODAY...IN COMPARISON TO THAN THE GFS AND GEM.
SENSIBLE WEATHER WILL FEATURE SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS SLOWLY EXITING EAST KENTUCKY AS A SFC WAVE AND COLD
FRONT DEPARTS TO THE SOUTHEAST BY LATE AFTERNOON. COOLER AIR WITH
THIS BOUNDARY...LOW CLOUDS...AND THE PCPN WILL KEEP TEMPERATURES ONLY
IN THE 70S TODAY. HIGH PRESSURE THEN SETTLES INTO THE AREA TONIGHT
WITH DRIER AIR AND EVEN COOLER TEMPERATURES. THE MAIN QUESTION FOR
TONIGHT WILL BE HOW MUCH CLOUD COVER WILL REMAIN OVER EAST KENTUCKY
IN THE WAKE OF THE FRONT. THE TIME SECTIONS FROM THE NAM12 SUGGEST
THAT LOW CLOUDS WILL BE TOUGH TO CLEAR THROUGH DAWN SO HAVE GONE
CLOUDIER WITH THE GRIDS...WITH LIMITED RADIATIONAL COOLING AND FOG
ANTICIPATED FOR THIS REASON. THESE CLOUDS SHOULD START TO BREAK UP
MORE EFFECTIVELY ON FRIDAY ALLOWING FOR A WARMUP BACK INTO THE LOW
80S...ALONG WITH PLEASANT HUMIDITY LEVELS.
HAVE USED THE CONSSHORT AS A STARTING POINT FOR TEMPERATURES...
DEWPOINTS...AND WINDS THROUGH THE FIRST 24 HOURS AND THEN THE CONSALL
THEREAFTER. AS FOR POPS...HAVE ENDED UP ON THE HIGH SIDE OF THE MOS
NUMBERS...CLOSER TO THE MET...TODAY WITH LOW POPS TONIGHT AND
FRIDAY...IN LINE WITH THE GUIDANCE.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 350 AM EDT THU JUL 24 2014
THE EXTENDED PORTION OF THE FORECAST BEGINS ON FRIDAY NIGHT WITH A
CONTINUED AND PRONOUNCED RIDGE OVER THE WEST AND DEEPENING TROUGH
OVER THE EASTERN CONUS. BOTH THE GFS AND EURO HINT AT A POSSIBLE
WEAKENING MCS TRAVERSING OVER THE RIDGE AND THROUGH THE UPPER MS
RIVER VALLEY AND INTO THE OH VALLEY ON FRIDAY NIGHT. FOLLOWING THIS
WILL BE A STRONG SHORT WAVE MOVING SOUTHEAST FROM MN AND INTO THE OH
VALLEY BY SUNDAY AND SUNDAY NIGHT. AS THIS WAVE SWINGS THROUGH THE
BASE OF THE TROUGH...A 90 KNOT JET MAX WILL PUSH THROUGH DEEPENING
THE LONG WAVE TROUGH OVER THE EASTERN CONUS AND KEEPING THE QUITE
AMPLIFIED TROUGH IN PLACE THROUGH THE REST OF THE EXTENDED. IN
RESPONSE...THE WESTERN RIDGE INCREASES IN STRENGTH KEEPING A RARE
MERIDIONAL PATTERN IN PLACE FOR THIS TIME OF YEAR. WITH THE MODELS
SHOWING SOME AGREEMENT IN THIS TREND IT CAN BE SAFE TO SHOW A HIGH
LEVEL OF CONFIDENCE WITH THE ALL MODEL BLEND SOLUTION.
FOR SOME MORE DETAILS IN THE LOWER LEVELS...THE MODELS SEEM TO BE IN
AGREEMENT WITH THE DECAYING MCS MAKING IT INTO THE AREA FRIDAY
NIGHT. THIS SHOULD ERODE THE ADVERTISED CAP THROUGH FRIDAY NIGHT AND
ALLOW SOME ADDITIONAL DEVELOPMENT INTO THE DAY ON SATURDAY WITH
DECENT INSTABILITY AVAILABLE AND SOME UPPER LEVEL SUPPORT ARRIVING
AHEAD OF A POTENT SHORTWAVE. THE BEST CHANCE FOR SHOWER AND
THUNDERSTORM DEVELOPMENT WILL COME ON SUNDAY AND INTO MONDAY WITH A
STRONG COLD FRONT MOVING THROUGH. WENT WITH THE LIKELY POPS
INHERITED FROM THE ALL MODEL BLEND. AT AN EARLY LOOK TO THIS
SCENARIO...QUITE A BIT OF DYNAMICS ARE WITH THIS FEATURE WITH THE
STRONG JET STREAK MOVING THROUGH THE OH VALLEY AND AFTERNOON CAPE
VALUES REACHING 2500 J/KG...A SEVERE WEATHER THREAT IS CERTAINLY NOT
OUT OF THE QUESTION IF THE STRENGTH OF THE WAVE HOLDS TRUE THROUGH
THE DAYS LEADING UP TO THE EVENT. THIS WILL BE THE REAL FORECAST
CHALLENGE AS THE POTENTIAL IS THERE...BUT WILL HAVE TO SEE HOW THE
MODELS TREND UP TO THE EVENT. A COUPLE WEAK DISTURBANCES WILL FOLLOW
BEHIND THIS WAVE AND WILL PROVIDE A LOW CHANCE FOR PRECIP INTO
TUESDAY BEFORE HIGH PRESSURE SETTLES IN FOR THE REST OF THE
EXTENDED. THE AIR MASS MOVING IN BEHIND THIS FRONT IS QUITE COOL
WITH HIGH TEMPERATURES FOR MONDAY THROUGH WEDNESDAY IN THE MID
70S...AROUND 10 DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. MODEL
TRENDS WOULD SUGGEST THAT AN OVERALL COOLER PATTERN FOR THE LAST
WEEK OF JULY WILL BE THE CASE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 655 AM EDT THU JUL 24 2014
SCATTERED SHOWERS AND THE OCCASIONAL THUNDERSTORM WILL CONTINUE TO
SLOWLY DRIFT SOUTHEAST THROUGH THE MORNING. AREAS OF DENSE FOG ARE
AFFECTING MANY OF THE AIRPORTS THIS MORNING IN LIEU OF THE
CONVECTION. EXPECT VIS AND CIG CONDITIONS TO GRADUALLY IMPROVE
FOLLOWING SUNRISE. HAVE KEPT THUNDER AND EVEN VCTS OUT OF THE TAFS AS
THE INSTABILITY WILL BE FAIRLY LOW THROUGH THE DAY...THOUGH A STRAY
STORM CANNOT BE RULED OUT. THE LATEST HRRR AND NAM12 CONTINUE TO
INDICATE THAT THE CURRENT BAND OF CONVECTION ALONG THE FRONT WILL
HOLD TOGETHER AS IT MAKES ITS FINAL PUSH ACROSS THE AREA. HAVE
A VCSH FOR THIS IN ALL SITES WITH CIGS GENERALLY AROUND 2K FEET. IN
THE WAKE OF THE FRONT LATER THIS EVENING...DRIER AIR IS EXPECTED TO
LIFT THE CIGS AND REMOVE THE THREAT OF SHOWERS. WINDS THROUGH THE
PERIOD WILL BE MAINLY LIGHT AND VARIABLE...THOUGH FAVORING THE
NORTHERLY DIRECTION LATER TODAY AND INTO THE EVENING. PATCHY FOG WILL
BE A CONCERN LATER TONIGHT AS WELL...BUT GENERALLY ONLY IF WE MANAGE
TO CLEAR OUT. FOR NOW WILL LEAVE THIS OUT OF THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ABE
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
242 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE BEHIND DEPARTING S/W ALLOWING CLOUDS TO THIN AND ADDNTL
HEATING TO OCCUR. MEANWHILE...SECOND ROUND OF CONVECTION DEVELOPING
ACROSS THE MTS TO THE NW WITH HRRR SUGGESTS THESE SAG SE ACROSS FA
LATER THIS AFTRN AND EVE. TMPS IN THE L-M80S.
PVS DSCN:
SURVEY TEAM AT THE EASTERN SHORE THIS AFTRN...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY IS
COMPLETED.
PVS DSCN:
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /19Z THURSDAY THROUGH TUESDAY/...
STATIONARY BOUNDARY DRAPED ACROSS SE VA AND CONTINUING WESTWARD.
THIS BOUNDARY WILL BE THE FOCUS FOR REDEVELOPMENT OF SHOWERS AND
THUNDERSTORMS THIS AFTERNOON. COVERAGE OF PRECIP IS BEGINNING TO
INCREASE AND A BETTER PICTURE OF TIMING AND IMPACTS FROM PRECIP AT
THE TAF SITES WILL CONTINUE TO UNFOLD THIS AFTERNOON.
THE FRONTAL BOUNDARY SLOWLY PUSHES SE OVERNIGHT CONTINUING A
CHANCE FOR SHOWERS. CLEARING WILL TAKE PLACE ON FRIDAY WITH VFR
CONDITIONS EXPECTED THROUGH SATURDAY.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...DAP
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
121 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT PUSHES ACROSS THE REGION LATER TODAY...THEN
DISSIPATES ACROSS THE CAROLINAS LATE TONIGHT THROUGH FRIDAY.
MEANWHILE, HIGH PRESSURE BUILDS NORTH OF THE AREA FRIDAY AND
SATURDAY. ANOTHER...STRONGER COLD FRONT WILL APPROACH THE AREA BY
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SUBSIDENCE BEHIND DEPARTING S/W ALLOWING CLOUDS TO THIN AND ADDNTL
HEATING TO OCCUR. MEANWHILE...SECOND ROUND OF CONVECTION DEVELOPING
ACROSS THE MTS TO THE NW WITH HRRR SUGGESTS THESE SAG SE ACROSS FA
LATER THIS AFTRN AND EVE. TMPS IN THE L-M80S.
PVS DSCN:
...SURVEY TEAM AT THE EASTERN SHORE THIS AFTRN...
CLUSTER OF SUPERCELLS OUT AHEAD OF COLD FRONT CRNTLY MOVG OFFSHORE
WITH NUMEROUS SPECIAL MARINE WARNINGS IN EFFECT. STRONGEST STORM
FORMED OVER THE CHES BAY JUST AFTER 8 AM THEN INTENSIFIED AS IT
MOVED ONSHORE AT A CAMPGROUND IN NORTHAMPTON COUNTY ARND 830 AM.
SEVERAL REPORTS OF INJURIES WITH NUMEROUS REPORTS OF DAMAGE RECEIVED.
SEE LSRAKQ FOR LATEST DETAILS. UPDATE TO BE ISSUED ONCE SURVEY IS
COMPLETED.
PVS DSCN:
TONIGHT...
BOUNDARY LOOKS TO STALL ACROSS SERN VA/NRN NC TONIGHT INTO FRI
MORNING AS THE UPPER TROF LINGERS ACROSS THE CAROLINAS THROUGH FRI
AFTN. WHILE POPS ARE DROPPED ACROSS THE NORTH, LOW END CHC POPS
LINGER SOUTH OF THE NC BORDER. WEAK FLOW WILL BRING ONLY MODEST
INFLUX OF COOLER/DRIER AIRMASS ACROSS NORTHERN ZONES, WITH ANOTHER
MUGGY NIGHT FOR MOST. EARLY MORNING LOWS IN THE LOW TO MID 60S FAR
NORTHERN ZONES, 65 TO AROUND 70 SOUTH ELSEWHERE.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
UPPER TROUGH AXIS PUSHES ACROSS FRIDAY INTO FRIDAY AFTN, WITH THE
SFC FRONT CLEARING THE CWA BY MIDDAY (STALLING JUST TO THE SOUTH
FRIDAY NIGHT). DRY FRI EXCEPT KEPT A SLIGHT CHC POP IN ACROSS NE NC
ZONES FRIDAY MORNING. THICKNESS TOOLS YIELD HIGHS IN THE L-M80S,
WHICH IS REFLECTED WELL BY THE GOING FORECAST.
WEAK CAA ACROSS THE NORTH AS HIGH PRESSURE BUILDS INTO THE AREA FROM
THE NORTH FRI NIGHT AND EARLY SATURDAY. GFS CONTINUES TO BRING
ACROSS SOME ISOLATED THUNDER BACK IN SAT AFTN AS LLVL SW FLOW
DEVELOPS AND PUSHES STALLED FRONT BACK NORTH. HOWEVER, WITH BEST
FORCING PASSING REGION WELL TO THE NORTH, AND WITH STRONG MIDLEVEL
CAP (INVERSION) EVIDENT ON FORECAST CROSS SECTIONS, THINKING IS THAT
OUR REGION WILL REMAIN DRY SATURDAY AND SAT NIGHT. HIGHS SAT 85-90.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
LONG TERM PERIOD STARTS OFF SAT NGT INTO SUN WITH AN UPR-LEVEL TROF
DIGGING OVR THE ERN CONUS AND SFC HI PRES PUSHING OFFSHORE. A
COMPLEX AREA OF SFC LO PRES WILL DEVELOP ACROSS THE GREAT LAKES
REGION...WITH A PREFRNTAL LEE TROF LEADING TO A CHANCE OF SHRAS/TSTMS
OVR THE LOCAL AREA. WITH DEEP S/SW FLOW...TEMPS WILL BE ABOUT FIVE
DEGREES ABOVE NORMAL...HIGHS IN THE LO TO MID 90S. THE
AFOREMENTIONED SFC LO WILL PUSH E AND DRAG A COLD FRNT INTO THE MID
ATLANTIC REGION MON/MON NGT. INCLUDED A 40% CHANCE OF SHRAS/TSTMS
DURING THIS TIME PERIOD. HIGHS MON IN THE UPR 80S TO LWR 90S. ASIDE
FM A LO CHANCE OF RAIN NEAR THE CST...CONDITIONS WILL DRY OUT FOR
TUE AND WED...WITH HIGHS ONLY IN THE MID 80S.
&&
.AVIATION /17Z THURSDAY THROUGH MONDAY/...
ISOLATED TO SCATTERED THUNDERSTORMS WILL LINGER OVER THE MD/VA
LOWER EASTERN SHORE IN THE VICINITY OF A THERMAL TROUGH THROUGH AT
LEAST 24/1000Z. AFTER WHICH...INCREASING CLOUD COVER AHEAD OF A
COLD FRONT NEAR THE WV/VA BORDER WILL OVERSPREAD THE ENTIRE AREA.
PATCHY FOG IS POSSIBLE FROM KSBY TO KLKU WITH CONDITIONS IMPROVING
AS THE NEXT BATCH OF RAIN MOVES EWD THIS MORNING...JUST AHEAD OF
THE FRONT. THUNDERSTORM DEVELOPMENT WILL BECOME FOCUSED ALONG THE
COLD FRONT AS THE DAY PROGRESSES...WITH BEST CHANCES EXPECTED TO
OCCUR SOUTHEAST OF KRIC. STORMS ARE NOT ANTICIPATED TO BECOME
SEVERE...HOWEVER LOCALLY STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL SHOULD BE THE MAIN IMPACTS TODAY. CONDITIONS DRY OUT FROM
NORTHWEST TO SOUTHEAST LATE THIS EVENING AND OVERNIGHT AS THE
FRONT STALLS ALONG THE NC COAST AFTER MIDNIGHT INTO FRIDAY
MORNING. LINGERING SHOWERS WILL BE POSSIBLE ACROSS FAR SE VA/NE NC
ON FRIDAY UNTIL THE FRONT PUSHES FARTHER TO THE SOUTHEAST AND HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WNW. THE HIGH THEN SLIDES
OFF THE MID ATLANTIC COAST BY SATURDAY...BRINGING A RETURN TO
RAIN-FREE CONDITIONS DURING MOST OF THE WEEKEND. THE NEXT COLD
FRONT APPROACHES THE REGION ON SUNDAY. IT IS EXPECTED TO CROSS THE
REGION SUNDAY NIGHT AND THEN STALL NEAR THE MID ATLANTIC COAST
MON/TUE.
NOTE: OBSERVATIONS FROM KSBY ARE NOT READILY AVAILABLE DUE TO A
COMMUNICATIONS PROBLEM. RETURN TO SERVICE IS UNKNOWN AT THIS TIME.
HOWEVER...CURRENT INFORMATION MAY BE OBTAINED BY CALLING INTO THE
ASOS SITE DIRECTLY. AMD NOT SKED WILL BE APPENDED TO THE KSBY TAF
UNTIL FURTHER NOTICE.
&&
.MARINE...
AN APPROACHING COLD FRONT IS POSITIONED ALONG THE NEW ENGLAND
COAST TO SRN NJ AND THEN CUTS WWD ACROSS NRN VA AS OF 330 AM THIS
MORNING. THIS FRONT WILL SLOWLY CROSS THE WATERS TODAY AND
THUNDERSTORM CHANCES WILL INCREASE AS THE DAY PROGRESSES. MAIN
IMPACTS WILL BE LOCALIZED STRONG WIND GUSTS AND BRIEF HEAVY
RAINFALL. THE COLD FRONT STALLS ALONG THE NC COAST LATER THIS
EVENING INTO FRI MORNING...THEN PUSHES FARTHER TO THE SOUTHEAST
FOR THE REST OF THE WEEKEND. WSW TO WNW WINDS WILL PREVAIL THIS
MORNING...THEN BECOME NW-N THIS AFTN THROUGH FRI MORNING (AOB 15 KT).
WAVES GENERALLY 1-2 FT TODAY THROUGH FRIDAY...WHILE SEAS AVERAGE
1-3 FT DURING THE SAME TIME.
AN UPPER LEVEL TROUGH PUSHES ACROSS THE WATERS ON FRI AS SFC HIGH
PRESSURE BUILDS BACK INTO THE MID ATLANTIC REGION. WINDS N-NE AOB
10 KT FRI/FRI NIGHT. THE SFC HIGH THEN SLIDES OFF THE MID ATLANTIC
COAST BY SAT MORNING WITH WEAK CAA OCCURRING BEHIND ITS DEPARTURE.
THIS WILL MARK A RETURN TO ONSHORE E-SE WINDS AOB 15 KT THROUGH THE
REST OF THE WEEKEND. AN APPROACHING COLD FRONT ON SUNDAY WILL CAUSE
THE PRESSURE GRADIENT TO TIGHTEN AND A SLY SURGE IN WINDS IS
ANTICIPATED SAT NIGHT. THIS MAY PUSH SPEEDS INTO LOW-END SCA FOR
CHES BAY AND CURRITUCK SOUND (AOB 20 KT)...HOWEVER WAA PROCESSES MAY
PREVENT THIS FROM ACTUALLY HAPPENING. WILL MONITOR MODEL TRENDS OVER
THE NEXT FEW DAYS TO DETERMINE IF SCA HEADLINES ARE NECESSARY. THE
COLD FRONT IS EXPECTED TO CROSS THE WATERS LATE MON/MON NIGHT.
&&
.EQUIPMENT...
KDOX RADAR HAS RETURNED TO SERVICE BUT REMAINS UNSTABLE.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MAM
NEAR TERM...MPR/MAM
SHORT TERM...MAM
LONG TERM...MAS
AVIATION...BMD
MARINE...BMD
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1159 AM CDT THU JUL 24 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT THU JUL 24 2014
STOUT UPPER RIDGE REMAINS CENTERED OVER COLORADO THIS MORNING...WITH
ITS ASSOCIATED RIDGE AXIS EXTENDING UP THROUGH THE CENTRAL DAKOTAS.
THIS RIDGE HAS A VERY WARM EML ASSOCIATED WITH IT /SEE +17C H7 TEMP
ON THE UNR SOUNDING LAST NIGHT/ AS WE CONTINUE TO SEE SHORTWAVES AND
ASSOCIATED STORMS ROTATE AROUND THE PERIPHERY OF THE RIDGE...THE
MOST IMPRESSIVE OF WHICH THIS MORNING IS UP IN NORTH CENTRAL
MONTANA. BY TONIGHT THE RIDGE AXIS WILL SHIFT INTO MN...THOUGH WILL
BE GETTING FLATTENED OUT BY THE H5 LOW CURRENTLY OVER WASHINGTON
THAT WILL MOVE INTO THE CANADIAN PRAIRIES OVERNIGHT.
THIS MORNING...HIGH PRESSURE CENTERED OVER WRN LAKE SUPERIOR HAS A
COOL A DRY AIRMASS IN PLACE THAT WILL LIKELY DELAY THE ARRIVAL OF
PRECIP. HAVE CUT BACK CONSIDERABLY ON POPS THROUGH THE
AFTERNOON...WITH MOST GUIDANCE SHOWING THE DAY GOING BY DRY AS THE
LLJ AND THETA-E RIDGE LOOK TO REMAIN ACROSS THE DAKOTAS THROUGH THE
DAY. THE ONLY THING TO WATCH WILL BE THAT MONTANA WAVE THAT WILL BE
DIVING SE ACROSS NODAK THIS MORNING AS IT WORKS AROUND THE RIDGE.
NMM/ARW WRFS SHOW REMNANTS OF THIS ACTIVITY WORKING ACROSS WRN MN
THIS AFTERNOON...BUT CONSIDERING THE RAP DOES NOT SHOW THE ELEVATED
INSTABILITY MAKING MUCH PROGRESS ACROSS THE DAKOTAS TODAY...FAVORED
THE DRY FORECAST FOR TODAY HIGHLIGHTED BY THE DETERMINISTIC MODELS.
BASICALLY...LEFT SOME SLIGHT CHANCES THROUGH THE AFTERNOON SW OF THE
MN RIVER...CLOSER TO WHERE THE BETTER MOISTURE TRANSPORT INTO SE
SODAK WILL BE. OTHERWISE...FEW CHANGES WERE NEEDED FOR TODAY...WITH
SRLY WINDS BRINGING IN SLIGHTLY WARMER AIR RESULTING IN HIGHS A
COUPLE OF DEGREES WARMER THAN WHAT WE SAW WEDNESDAY.
TONIGHT LOOKS TO BRING OUR BEST CHANCE FOR PRECIP OVER THE NEXT
WEEK. SOME MODEL DISAGREEMENT STILL EXISTS...WITH A COUPLE OF CAMPS
EXISTING WITH THE NAM/GFS/ECMWF CONTINUING TO HIGHLIGHT THE
POTENTIAL FOR WIDESPREAD ELEVATED CONVECTION FROM SOUTH CENTRAL MN
INTO NE IA...WHILE THE GEM AND WRF BASED CAMS SHOW CONSIDERABLY LESS
ACTIVITY IN THE MPX AREA...WITH TWO AREAS OF CONVECTION DEVELOPING
OVERNIGHT DOWN ACROSS IA AND ACROSS CENTRAL/NRN MN. THE FIRST OF THE
SOLUTIONS MAINTAINS GOOD CONTINUITY WITH THE EXISTING FORECAST...SO
FAVORED THIS FORECAST TOWARD THAT CAMP AS THIS ALSO MATCHES UP WELL
WITH EXPECTED EVOLUTION OF THE LLJ AS IT STRENGTHENS UP INTO SW
MN AFTER 00Z AND VEERING INTO IA OVERNIGHT...WITH STORMS DEVELOPING
ON THE NOSE OF THE LLJ AND EDGE OF THE CAPPED EML. THOUGH NOT
EXPECTING WIDESPREAD SEVERE WEATHER...GIVEN STRENGTH OF ELEVATED
INSTABILITY MOVING IN...ALONG WITH EFFECTIVE BULK SHEAR AROUND 40
KTS...COULD CERTAINLY SEE A FEW STRONGER CELLS CAPABLE OF PRODUCING
LARGE HAIL...BUT FOR THE MOST PART...ACTIVITY SHOULD REMAIN SUB
SEVERE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 354 AM CDT THU JUL 24 2014
SCATTERED SHOWERS AND THUNDERSTORMS SHOULD BE IN PROGRESS ACROSS
EASTERN MN AND WESTERN WI FRIDAY MORNING IN AN AXIS OF LOW LEVEL
MOISTURE TRANSPORT...AN APPROACHING MID LEVEL SHORT WAVE AND
COUPLED UPPER LEVEL JET. THE NSSL...SPC AND ARW WRF/S DEPICT THE
SITUATION WELL WITH THE NMM WRF LAGGING A BIT TO THE NW. THE
SHOWERS AND THUNDERSTORMS WILL DIMINISH ACROSS WESTERN WI IN THE
AFTERNOON. MID LEVEL TEMPERATURES WILL BE RISING INTO THE 12-16
DEG C RANGE ACROSS CENTRAL AND SOUTHERN MN DURING THE DAY ON
FRIDAY AND THIS SHOULD AID IN CAPPING ANY FURTHER DEVELOPMENT
ALONG A WEAKENING COOL FRONT ACROSS WESTERN MN. DRY WEATHER IS
THEN EXPECTED OVER MUCH OF THE FA FRIDAY NIGHT AND SATURDAY.
A COMPACT VERTICALLY STACKED LOW PRESSURE SYSTEM REMAINS ON TRACK
TO DROP SOUTHEAST ACROSS THE UPPER MISSISSIPPI VALLEY SATURDAY
NIGHT AND SUNDAY. LAYER MOISTURE AND FORCING IS BEST TO THE NORTH
AND EAST OF THE TWIN CITIES WHERE HIGH CHANCE POPS FOR SHOWERS AND
ISOLATED THUNDERSTORMS CONTINUE. LOW CHANCE POPS ARE IN PLACE
FROM THE TWIN CITIES ON WEST AND SOUTH. AFTER HIGHS ON SATURDAY IN
THE LOWER TO MIDDLE 80S...HIGHS ON SUNDAY WILL DROP INTO THE LOWER
TO MIDDLE 70S.
THE TREND OF COOLER THAN NORMAL TEMPERATURES WILL PERSIST AT LEAST
INTO THE MIDDLE OF NEXT WEEK AS A DEEP UPPER LOW/TROUGH TAKES
SHAPE OVER EASTERN NORTH AMERICA WHILE MASSIVE RIDGING BUILDS IN
THE FAR WEST. HENCE...A NORTHWEST UPPER FLOW WILL PREVAIL ACROSS
THE FA FOR MUCH OF NEXT WEEK. IT LOOKS PRETTY DRY WITH NO POPS
MENTIONED SUNDAY NIGHT THROUGH TUESDAY NIGHT. SMALL CHANCE POPS
BEGIN TO CREEP BACK IN ON WEDNESDAY OVER THE WI CWA AS WELL AS THE
SOUTHWEST CORNER OF MN. HIGHS IN THE LOWER TO MIDDLE 70S ON MONDAY
WILL RISE INTO THE UPPER 70S TO AROUND 80 BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1143 AM CDT THU JUL 24 2014
RADAR TRENDS SUGGEST SCATTERED ACTIVITY TO MOVE INTO WESTERN MN
THIS AFTERNOON. BELIEVE IT WILL HOLD OFF AT KSTC AND EAST THROUGH
MOST OF THE EVENING WITH THE BEST CHANCE MOVING IN AFTER 06Z
ACROSS THE SOUTHEAST PORTION OF THE AREA. WILL BRING IN SOME
THUNDER TO KRWF THIS EVENING WITH PERHAPS A SHRA THIS AFTERNOON
BEFORE 23Z. WILL SPREAD THIS EAST OVERNIGHT...LEAVING ACTIVITY OUT
OF WEST CENTRAL WISCONSIN DOE TO UNCERTAINTY. CAPE BUILDS INTO
FRIDAY AND MAY SEE SOME THREAT OF WIDELY SCATTERED ACTIVITY ALONG
AND EAST OF THE FRONT INTO THE AFTERNOON. APPEARS FROPA WILL ONLY
MAKE IT INTO WESTERN MN DURING THE AFTERNOON...AND EXITING WC
WISCONSIN AFTER 06Z SAT. SOME THREAT OF MVFR CIGS
DEVELOPING LATE TONIGHT...ESPECIALLY IF A MORE WIDESPREAD MCS
DEVELOPS. STILL SOME UNCERTAINTY TO COVERAGE...SO WILL LEAVE VFR
INTO FRIDAY.
KMSP...
WILL CONTINUE TO MENTION PROB30 TSRA IN THE 08Z-12Z PERIOD...PER
MODEL DISCREPANCY IN OVERALL DEVELOPMENT/PLACEMENT DURING THE
NIGHT. TRENDS SHOULD FAVOR SOMETHING DEVELOPING FARTHER EAST AFTER
06Z FRI...LIKE WE HAVE IT AS LLJ AND INSTABILITY GRADIENT SHIFTS
EAST. SOME THREAT OF MVFR CIG INTO FRIDAY MORNING...BUT WILL LEAVE
VFR FOR NOW DUE TO LOW CONFIDENCE. STILL SOME THREAT OF TSRA INTO
FRIDAY AHEAD OF SLOW MOVING FRONT INTO THE AFTERNOON...BUT
BELIEVE IT WILL BE RATHER ISOLD IN NATURE AND WILL LEAVE THIS OUT
FOR NOW. SOUTHEAST TO SOUTH WINDS AHEAD OF FRONT BECOMING WEST
INTO FRIDAY EVENING.
/OUTLOOK FOR KMSP/
FRI...CHC MVFR CIGS/ISOLD TSRA. WINDS SSE AT 5-10KTS.
SAT...VFR. WINDS WSW AT 5-10KTS.
SUN...VFR. CHANCE SHRA/MVFR CIGS. WINDS NW AT 10-15 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS HASTINGS NE
338 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
FAIRLY QUIET DAY WITH MOSTLY SUNNY SKIES AS THE UPPER LEVEL RIDGE
AXIS CONTINUES TO MOVE OVERHEAD. 12Z SUBJECTIVE UPPER AIR ANALYSIS
IN ADDITION TO RAP ANALYSIS SHOWS A STOUT MID LEVEL WARM POCKET OVER
THE HIGH PLAINS REGION. THIS CONTINUES TO DRIFT EWD WHICH WOULD
TYPICALLY CAP OFF ANY POTENTIAL THUNDERSTORM DEVELOPMENT. THIS BEING
SAID...AN AREA OF CONVECTION HAS MANAGED TO DEVELOP OVER THE
NEBRASKA PANHANDLE AND PORTIONS OF NORTHEAST COLORADO IN ADVANCE OF
A WEAK VORT MAX. LATEST RUNS OF THE HRRR AND RAP INDICATE THIS
CONVECTION HOLDING ON AND SPREADING EAST THROUGHOUT THE LATER
EVENING HOURS. AS A RESULT...WILL HOLD ONTO SMALL POPS ACROSS THE
NORTHERN CWA.
ATTENTION THEN TURNS TO HEAT TOMORROW. HIGHS SHOULD REACH THE 100
DEGREE MARK ACROSS THE KANSAS COUNTIES WITH UPPER 90S SOUTH OF
INTERSTATE 80. COMBINED WITH SFC DEWPOINTS IN THE UPPER 60S...WE
SHOULD APPROACH HEAT INDICES IN THE 105+ RANGE. AS A RESULT...WILL
GO AHEAD AND ISSUE A HEAT ADVISORY FOR PORTIONS OF SOUTH CENTRAL
NEBRASKA AND ALL THE NORTH CENTRAL KANSAS COUNTIES.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 PM CDT THU JUL 24 2014
ANOTHER HOT DAY IS EXPECTED ON SATURDAY WITH POTENTIAL FOR HEAT
ADVISORY CRITERIA AGAIN. WILL LET LATER SHIFTS EVALUATE FOR
ADDITIONAL HEADLINES. A COLD FRONT WILL DROP OVER THE AREA SATURDAY
NIGHT WITH HIGH PRESSURE BUILDING ACROSS THE AREA SUNDAY INTO
MONDAY. MUCH COOLER AND DRIER AIRMASS WILL ALLOW TEMPS TO DROP INTO
THE LOW 80S FOR HIGHS AND LOW 60S FOR LOWS.
RETURN FLOW WILL SET UP EARLY NEXT WEEK WHILE A SERIES OF UPPER
LEVEL SHORTWAVES ARE FORECAST TO PASS THROUGH THE REGION IN
MID/UPPER LEVEL NORTHWESTERLY FLOW. MODEL CONSENSUS HAS PUT AT LEAST
A SLIGHT CHANCE OR CHANCE OF TSTMS FROM MONDAY NIGHT THROUGH
THURSDAY. ALTHOUGH WIDESPREAD CONTINUOUS PCPN IS NOT
ANTICIPATED...WILL LEAVE THESE CHANCES IN DUE TO UNCERTAINTY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1238 PM CDT THU JUL 24 2014
VFR CONDITIONS EXPECTED THRU THE FCST PD.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR NEZ063-064-
074>077-083>087.
KS...HEAT ADVISORY FROM NOON TO 7 PM CDT FRIDAY FOR KSZ005>007-
017>019.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DEE
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
240 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY AND PUSH
INTO THE AREA TONIGHT...THEN STALL ACROSS SOUTHERN AREAS FRIDAY
AND FINALLY DISSIPATE SATURDAY. ANOTHER COLD FRONT WILL APPROACH
THE AREA EARLY NEXT WEEK...PUSHING THROUGH THE AREA TUESDAY. HIGH
PRESSURE WILL BUILD INTO THE AREA WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 225 PM THURS...A FEW SEVERE THUNDERSTORM WARNINGS WERE
ISSUED EARLIER THIS AFTERNOON FOR THE COASTAL PLAIN COUNTIES BUT
THE LINK HAS SINCE SHIFTED SOUTH AND WEAKENED. THE LINE OF STORMS
CURRENTLY STRETCHES FROM THE CENTRAL OBX WEST TO SOUTH OF NEW BERN
WEST TO NEAR KENANSVILLE. FREQUENT LIGHTNING...GUSTY WINDS...AND
HEAVY RAIN CAN BE EXPECTED WITH THESE STORMS. THE ENVIRONMENT WAS
MORE CONDUCIVE FOR SEVERE STORMS EARLIER BUT LATEST SPC MESOANALYSES
INDICATE EFFECTIVE BULK SHEAR OF 30 KT OVER SOUTHERN PORTIONS AND
45 KT FARTHER INLAND WHERE THE ATMOSPHERE HAS ALREADY BEEN WORKED
OVER. MULTI MODEL SOUNDING ANALYSES INDICATE A MODERATELY
UNSTABLE AIRMASS THIS AFTERNOON WITH LIFTED INDICES -6 TO -8
C...SBCAPE VALUES 2000-2500 J/KG...AND ABUNDANT MOISTURE WITH
PWATS ABOVE 2 INCHES. BIGGEST THREAT REMAINS DAMAGING WIND GUSTS.
CANNOT COMPLETELY RULE OUT HAIL AS WELL THIS AFTERNOON BUT VERY
HIGH FREEZING LEVELS ON THE ORDER OF 14750-15250 FEET WOULD ARGUE
AGAINST MUCH WIDESPREAD HAIL THREAT.
BERMUDA HIGH PRESSURE CONTINUES TO RIDGE INTO THE SOUTHEAST WITH A
TROUGH OF LOW PRESSURE ACROSS THE PIEDMONT. AN UPPER TROUGH
AND ATTENDANT SFC COLD FRONT ARE PUSHING ACROSS THE MID ATLANTIC
AND CENTRAL APPALACHIANS. THE FRONT...PIEDMONT TROUGH AND
SEABREEZE HAVE ALL BEEN TRIGGERS FOR CONVECTION THIS AFTERNOON BUT
EXPECT SHOWERS/STORMS TO WANE FOR INLAND/NW ZONES THAT HAVE BEEN
WORKED OVER. 16Z HRRR SUGGESTS MORE SHOWERS/STORMS TO DEVELOP
ALONG THE FRONT AND IMPACT THE AREA FROM NW TO SE THIS EVENING
INTO THE OVERNIGHT HOURS AS THE FRONT MOVES SE THROUGH THE AREA.
HAVE TRENDED POPS SIMILAR TO THE HRRR. TEMPS OVERNIGHT WILL BE
MILD WITH LOWS IN THE LOW 70S INLAND TO MID 70S ALONG THE COAST
AND OBX. CANNOT RULE OUT PATCHY FOG INLAND FOR AREAS THAT OBSERVED
HEAVY RAIN THIS AFTERNOON.
&&
.SHORT TERM /FRIDAY/...
AS OF 235 PM THURS...THE FRONT WILL STALL ACROSS THE SOUTHERN COASTAL
WATERS FRI WITH A SURFACE RIDGE OVER THE MID-ATLANTIC STATES BUILDING
SOUTH OVER THE AREA DURING THE DAY. WINDS WILL SHIFT NE THEN E BY
LATE IN THE DAY. ONLY ISOLATED SHOWERS OR THUNDERSTORMS WILL BE
POSSIBLE TOMORROW BUT BEST FOCUS FOR STORMS AND UPPER SUPPORT
REMAIN OFF THE NC COAST AND SOUTH OF THE MHX CWA. LOW LEVEL THICKNESSES
FALL ROUGHLY 20 METERS FRI ALLOWING MAX TEMPS TO BUILD INTO THE
MID/UPPER 80S.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
AS OF 215 PM WED...FRI NIGHT THRU EARLY SUNDAY LOOKS MAINLY DRY AS
UPR TROF LIFTS OUT WITH ZONAL FLOW ALOFT. CONT ISOLD POPS FOR CSTL
WTRS FRI NIGHT AND INLAND SXNS SAT. MDLS AGREE NOW THAT SUN SHLD
REMAIN MAINLY DRY AS DEEPER MOISTURE REMAINS TO THE NW SO LOWERED
POPS TO SLIGHT INLAND. BEST CHC OF RAIN LOOKS TO BE MON AFTN AND
EVENING AS RATHER STRONG FRONT FOR LATE JULY PUSHES THRU THE
REGION...CONT CHC POPS. FRONT PUSHES OFFSHORE AND STALLS MID WEEK
WITH DRIER AIR OVER THE REGION AND MAINLY DRY WX EXPECTED. MOISTURE
BEGINS TO INCREASE THU SO INCREASED POPS TO CHC. HIGHS WILL BE IN THE
UPR 80S TO LOWER 90S INLAND SAT THEN 90 TO 95 SUN AND MON WITH GOOD
LOW LVL SW FLOW AHEAD OF THE APPROACHING COLD FRONT. FRONT WILL PUSH
OF THE CST TUE AND STALL OFFSHORE WED AND THU WITH HIGHS MAINLY IN
THE LOW TO MID 80S.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHORT TERM /TONIGHT THROUGH FRIDAY/...
AS OF 215 PM THURS...STRONG LINE OF CONVECTION ACROSS EASTERN NC WILL
AFFECT MAINLY TERMINALS EWN AND OAJ OVER THE NEXT FEW HOURS.
HOWEVER...THREAT OF CONVECTION WILL CONTINUE THROUGH EARLY EVENING
ALONG AND AHEAD OF COLD FRONT. THE FRONT WILL PUSH OFF THE SOUTH
COAST AFTER MIDNIGHT. FORECAST SOUNDINGS AND TIME SECTIONS INDICATE
BKN-OVC MID DECK WILL PERSIST OVERNIGHT SO AM NOT FORECASTING DENSE
FOG... WILL LEAVE IT AT MVFR. MID CLOUD WILL CONTINUE INTO FRIDAY
MORNING WITH A LIGHT NORTHEAST WIND. SHOWERS POSSIBLE OVERNIGHT INTO
FRIDAY BUT ONLY ISOLATED SO DID NOT PUT IN A MENTION IN THE FORECAST.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
AS OF 215 PM THURSDAY...MAINLY VFR CONDS EXPECTED FRI NIGHT THRU SUNDAY
WITH LIMITED PRECIP. HOWEVER...LIGHT WINDS AND AMPLE LOW LEVEL
MOISTURE FRI NIGHT AND SAT NIGHT COULD RESULT IN PATCHY FOG AND ST
WITH REDUCED CIGS/VSBYS. SHRA AND TSRA WILL INCREASE IN CVRG MON AND
MON EVENING ALONG AND AHEAD OF COLD FRONT WITH SOME BRIEF PDS OF
REDUCED FLIGHT CATEGORIES. THE FRONT SHLD PUSH E OF TAF SITES TUE
WITH VFR EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 240 PM THURS...LATEST SURFACE AND BUOY DATA INDICATE WSW/SW
WINDS 10-20 KT WITH SEAS 2-4 FT FOR THE SOUTHERN WATERS. WINDS FOR
THE CENTRAL AND NORTHERN WATERS HAVE BEEN ALTERED DUE TO A LINE OF
STRONG THUNDERSTORMS MOVING FROM NW TO SE THROUGH THE WATERS.
NORTH OF THIS LINE...WINDS HAVE SHIFTED NW AND HAVE GUSTED UPWARDS
OF 30 KNOTS AT TIMES. SEAS REMAIN 2-3 FT FOR THE NORTHERN WATERS.
A COLD FRONT WILL APPROACH FROM THE NW TONIGHT AND CROSS INTO THE
WATERS AFTER MIDNIGHT...AND EVENTUALLY OFF THE SOUTHERN COAST ON
FRI. WINDS WILL SHIFT N THEN NE BEHIND THE FRONT TONIGHT INTO FRI
AS HIGH PRESSURE OVER THE MID-ATLANTIC STATES BUILDS SOUTH INTO
THE REGION. SEAS WILL REMAIN 2-4 FT THROUGH THE SHORT TERM.
LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/
AS OF 210 PM THURS...STATIONARY FRONT S OF THE WATERS WASHES OUT
FRI NIGHT AND SAT WITH LIGHT AND VARIABLE WINDS EXPECTED FRI NIGHT
BECOMING SSW 10 TO 15 KTS LATER SAT. PRES GRAD TIGHTENS SUN AND
MON AS COLD FRONT APPROACHES WITH WINDS INCRG TO 15 TO 20 KTS SUN
AFTN AND 20 TO 25 KTS LATE SUNDAY NIGHT CONTG THRU MON EVENING. AS
FRONT PUSHES OFF THE CST LATER MON NIGHT AND TUE WINDS WILL BECOME
NW TO N BELOW 15 KT.
SEAS 2 TO 3 FEET FRI EVENING THRU MOST OF SAT. SEAS WILL BUILD TO 2
TO 4 FT SAT NIGHT AND REACH 4 TO 5 FT OUTER WTRS SUN AFTN. SEAS WILL
PEAK AT 5 TO 7 FT LATER SUN NIGHT THRU MON EVENING. AS WINDS SHIFT
TO NW AND N BEHIND FRONT SEAS WILL SUBSIDE TO 3 TO 5 FT LATE MON
NIGHT AND EARLY TUE...WITH 2 TO 4 FT BY TUE AFTN.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...DAG
LONG TERM...RF
AVIATION...RF/HSA
MARINE...RF/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1246 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TODAY...BRINGING AN
INCREASING RISK FOR STRONG THUNDERSTORMS LATE THIS AFTERNOON INTO
TONIGHT. THIS FRONT WILL STALL ACROSS THE AREA FRIDAY BEFORE
DISSIPATING ON SATURDAY. HIGH PRESSURE WILL BRING HOT AND HUMID
CONDITIONS SUNDAY AND MONDAY. A STRONG COLD FRONT WILL CROSS THE
AREA EARLY TUESDAY...BRINGING COOLER AND DRIER CONDITIONS FOR THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1015 AM THURSDAY...OUR CUMULUS FIELD CONTINUE TO GROW AND
VISIBLE SATELLITE SUGGESTS TOWERING CUMULUS AND CB`S ARE DEVELOPING
ACROSS THE NORTHERN PIEDMONT AND SANDHILLS REGION OF SOUTH CAROLINA.
THIS AND AREAS DOWNSTREAM ACROSS BENNETTSVILLE...LUMBERTON AND
ELIZABETHTOWN WILL PROBABLY BE THE FIRST TO EXPERIENCE SCATTERED
THUNDERSTORMS IN THE NEXT 60-90 MINUTES. VIRTUALLY ALL MODEL
GUIDANCE (BOTH SYNOPTIC-SCALE AND MESOSCALE) INDICATES IT WILL TAKE
UNTIL LATE AFTERNOON OR EARLY EVENING FOR STORMS TO SPREAD DOWN TO
THE COAST...SO I HAVE TRIMMED BACK POPS THROUGH 21Z/5 PM INTO THE
CHANCE (30-50% RANGE) WITH THE CONTINUED EXPECTATION OF MORE
SUBSTANTIAL COVERAGE AFTER 5 PM. PREVIOUS DISCUSSION FROM 1015 AM
FOLLOWS...
CLEAR SKIES OVER THE AREA THIS MORNING SHOULD TURN PARTLY CLOUDY
OVER THE NEXT FEW HOURS. TEMPERATURES ARE SOARING QUICKLY WITH MID
TO UPPER 80S ALREADY OBSERVED. THE LATEST FEW HRRR RUNS PLUS THE 00Z
NSSL WRF ARE SHOWING A LATER CONVECTIVE INITIATION TIME THAN OUR
PREVIOUS FORECAST INDICATED...SO I HAVE SHIFTED THE WINDOW OF
HIGHEST FORECAST POPS INTO THE 4 PM TO 10 PM RANGE. THIS ALSO IS
WHEN WE COME UNDER THE BEST INFLUENCE OF THE RIGHT-ENTRANCE REGION
OF A HEALTHY 300 MB JET EXTENDING FROM THE MID-ATLANTIC INTO THE
CANADIAN MARITIMES. NO OTHER SIGNIFICANT CHANGES ARE NEEDED...AND
FORECAST TEMPERATURES/DEWPOINTS STILL SUPPORT HEAT INDICES IN THE
100-104 RANGE THIS AFTERNOON. PREVIOUS DISCUSSION FROM 600 AM
FOLLOWS...
A QUICK MOVING MID-LEVEL SHORTWAVE MOVED ACROSS THE UPSTATE OF SOUTH
CAROLINA DURING THE LATE NIGHT AND WAS CURRENTLY MOVING NE ACROSS
CENTRAL NORTH CAROLINA. A FEW SHOWERS AND THUNDERSTORMS DEVELOPED IN
RESPONSE TO THIS ADDED LIFT AND ARE EXPECTED TO PASS BY TO OUR NORTH
THROUGH 9 AM. A WEAKER SECONDARY IMPULSE WAS MOVING NE ACROSS THE
EASTERN CAROLINAS...BUT CONVECTION HAS NOT DEVELOPED IN RESPONSE TO
THIS FEATURE.
A COLD FRONT WILL DROP INTO THE LEE SIDE TROUGH POSITION TODAY
AND THE FRONT WILL THEN SLIDE ACROSS THE FORECAST AREA TONIGHT...
LIKELY LYING ACROSS SOUTHERN AND EASTERN PORTIONS OF THE FORECAST
AREA AT DAYBREAK FRI. THE UPPER TROUGH WILL STILL BE UPSTREAM FRI
MORNING.
THE ATMOSPHERE WILL BE WARM AND MOIST THROUGH A DEEP LAYER WITH
PRECIPITABLE WATER VALUES INCREASING THROUGH THE AFTERNOON/EVE...
IN EXCESS OF 2 INCHES...AND ALONG THE COAST...ABOVE 2.25 INCHES.
TEMPERATURES ARE EXPECTED TO REACH THE LOWER TO MID 90S TODAY. THIS
WILL BRING MIXED LAYER CAPE VALUES IN THE NEIGHBORHOOD OF 2000-2500
J/KG. MID LEVEL LAPSE RATES AND SHEAR VALUES ARE UNIMPRESSIVE...BUT
MID-LEVEL WINDS WILL BE ON THE ORDER OF 40 KT. THE BIGGEST RISK WITH
THUNDERSTORMS TODAY AND TONIGHT WILL BE FREQUENT LIGHTNING AND HEAVY
RAIN...ALTHOUGH STORM MOTIONS ARE MUCH HIGHER THAN EARLIER IN THE
WEEK WHICH SHOULD LIMIT THE EXCESSIVE RAINFALL THREAT. HOWEVER...THE
DEEPEST CONVECTION WILL BE CAPABLE OF STRONG WIND GUSTS AND AN
ISOLATED WET MICROBURST WITH DAMAGING WINDS CAN NOT BE RULED OUT.
THUNDERSTORMS MAY DEVELOP ALONG THE COAST AS A RATHER SHARP
SEABREEZE BOUNDARY DEVELOPS LATER THIS MORNING/MIDDAY. ELSEWHERE...
AFTERNOON THUNDERSTORMS WILL POP AS THE CONVECTIVE TEMPS ARE
EXCEEDED. THE CONVECTION SHOULD TEND TO BECOME MORE ORGANIZED MID
AND LATE AFTERNOON AS IT MOVES TOWARD THE COAST. WE EXPECT
CONVECTION TO LAST WELL INTO THE NIGHT IF NOT THROUGH THE NIGHT AS A
MODEST SHORTWAVE ALOFT INTERACTS WITH THE SURFACE FRONT.
HEAT INDEX VALUES LATE MORNING AND THIS AFTERNOON WILL REACH 100
DEGREES IN MOST AREAS AND AS HIGH AS 104 DEGREES. OF COURSE...ONCE A
STRONG THUNDERSTORM MOVES OVERHEAD...THE HEAT WILL GET KNOCKED
DOWN...BUT NOT THE HUMIDITY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...COLD FRONT STALLED ACROSS THE AREA WILL
CONTINUE SHOWER AND THUNDERSTORM CHANCES ON FRIDAY...BUT AT THE SAME
TIME DRIER AIR WILL BEGIN TO ADVECT IN FROM THE WEST...DRYING OUT
THE MID AND UPR PORTIONS OF THE COLUMN. STILL...WITH THE FRONT IN
PLACE...TEMPS RISING TO AROUND 90...AND DEWPOINTS IN THE LOW
70S...THERE WILL BE PLENTY OF FUEL AROUND FOR CONVECTION BEFORE THE
DRIER AIR WORKS INTO THE CWA. THUS WILL CARRY CHC POP
FRIDAY...HIGHEST ACROSS THE EASTERN PORTIONS OF THE CWA. THE DIURNAL
TREND FOR CONVECTION MAY BE A BIT ATYPICAL AS THE DRY AIR INTRUDES
OVERHEAD...AND THE HIGHEST COVERAGE OF CONVECTION MAY BE LATE
MORNING/EARLY AFTN BEFORE TAPERING OFF INTO THE EVE. THIS FRONT WILL
WASH OUT FRIDAY NIGHT LEAVING MOSTLY CLEAR SKY CONDITIONS...BUT AS
LIGHT SW FLOW RE-DEVELOPS...MINS WILL FALL ONLY INTO THE MID 70S AT
THE COAST...AND TO AROUND 70 INLAND.
ANY AIRMASS CHANGE ASSOCIATED WITH THE PRIOR FRONT QUICKLY ERODES
SATURDAY...LEAVING A HOT DAY ACROSS THE CWA. FORTUNATELY...THE
COLUMN WILL BE DRIER...AND THUS HUMIDITY VALUES WILL BE MUCH
LOWER...KEEPING APPARENT TEMPS TO BELOW 100 EVEN AS HIGHS CLIMB TO
AROUND 90 AT THE COAST...MID 90S WELL INLAND. WILL CONTINUE WITH THE
INHERITED SCHC POP ON SATURDAY SIMPLY DUE TO THE HEAT...BUT ONLY
ISOLATED STORMS ARE POSSIBLE AS PWATS DROP TO LESS THAN 1.5 INCHES.
INCREASING SW RETURN FLOW SATURDAY NIGHT WILL PREVENT SIGNIFICANT
COOLING...AND THUS LOWS SAT NIGHT WILL BE WELL ABOVE NORMAL...UPR
70S AT THE BEACHES TO LOW 70S ONLY WELL INLAND.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...A HOT START TO THE PERIOD...BUT IT WILL BE
SHORT LIVED AS...ONCE AGAIN...AN ANOMALOUSLY STRONG UPPER TROUGH
DIVES ACROSS THE EASTERN CONUS.
SUNDAY LOOKS TO BE THE HOTTEST DAY OF THE PERIOD AS SUBTLE MID-LEVEL
RIDGING AND STRONG SW RETURN FLOW AROUND A RIDGE OF HIGH PRESSURE
PUSH TEMPS INTO THE MID AND MAYBE UPR 90S...AND WE MAY EXPERIENCE
OUR FIRST HEAT ADVISORY OF 2014 (HEAT INDEX OF 105 OR GREATER).
ALTHOUGH HUMIDITY WILL INCREASE ON SUNDAY AS WELL...CONVECTIVE
COVERAGE MAY BE QUITE LIMITED DUE TO SOME MID-LEVEL DRY AIR
PERSISTING...AND A LID WITHIN A LOW-LEVEL THERMAL RIDGE. MONDAY WILL
BE SIMILAR...ALTHOUGH A DEGREE OR 2 COOLER AS CLOUD COVER INCREASES
AND MID-LEVEL HEIGHTS DECREASE AHEAD OF AN ADVANCING COLD FRONT.
INCREASING POP IS WARRANTED MONDAY AS WELL...WITH THE BEST CHANCE
OCCURRING MONDAY NIGHT AS THE COLD FRONT MOVES INTO THE AREA. LOWS
BOTH NIGHTS WILL BE ABOVE NORMAL IN MID AND UPR 70S.
BIG AIR MASS CHANGE OCCURS THEREAFTER AS -3 SD TROUGH DROPS INTO
THE MIDWEST...DRIVING A STRONG COLD FRONT INTO THE CWA AND OFFSHORE
DURING TUESDAY. THIS TROUGH WILL PRODUCE LOWERED HEIGHTS ALL THE WAY
INTO THE GULF OF MEXICO THROUGH THE MIDDLE OF NEXT WEEK...BUT
FORTUNATELY FOR THE AREA THE TROUGH AXIS REMAINS DISPLACED WEST OF
THE COASTAL CAROLINAS. WHILE DRIER AND COOLER AIR IS ANTICIPATED
TUE/WED...WITH TEMPS RUNNING SEVERAL DEGREES BELOW NORMAL...LOCALLY
WE WILL NOT BE AS COOL AS OUR NEIGHBORS WELL WEST. LOWER POP IS
EXPECTED THROUGH MID-WEEK...BUT INCREASING E/NE FLOW MAY ALLOW FOR
RESIDUAL RAIN CHANCES TO PERSIST ALONG THE COAST THROUGH THE END OF
THE PERIOD.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...POSSIBLE MVFR/IFR IN ANY HEAVY DOWNPOURS THIS AFTERNOON
AND EVENING AS CHANCES FOR SHRA/TSRA INCREASING THROUGHOUT THE
DAY...ALONG WITH PATCHY FOG POSSIBLE BEFORE DAYBREAK ON FRIDAY.
OTHERWISE EXPECT VFR.
VFR PREVAILS THIS AFTERNOON WITH WEST-SOUTHWEST WINDS AOB 15 KTS AND
GUSTS ALREADY NEAR 20 KTS ALONG THE COAST. A CU FIELD HAS BEGUN TO
DEVELOP NICELY AS SEEN FROM LATEST SATELLITE IMAGERY AHEAD OF AN
APPROACHING COLD FRONT...AND EXPECT CLOUD COVER TO BE SCT/BKN
THROUGHOUT THE REST OF THE DAY AS CHANCES FOR SHRA/TSRA INCREASES.
THOUGH THUNDERSTORMS WILL TAPER OFF THIS EVENING...ANTICIPATE
SHOWERS TO PERSIST INTO THE EARLY OVERNIGHT HOURS. BRIEF PERIODS OF
MVFR/IFR ARE POSSIBLE IN ANY SHRA/TSRA ESPECIALLY WITH HEAVIER
DOWNPOURS AND LOWER CIGS. LATE OVERNIGHT INTO THE EARLY MORNING
HOURS...MVFR/IFR IS POSSIBLE DUE TO PATCHY FOG...ESPECIALLY INLAND.
INTO THE MORNING HOURS...LIGHT WINDS AND CONDITIONS WILL IMPROVE TO
VFR WITH A CHANCE OF SHRA/TSRA AGAIN ON FRIDAY.
EXTENDED OUTLOOK...SHOWERS/TSTMS/TEMPO MVFR POSSIBLE THROUGH
FRIDAY...AS WELL AS SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 100 PM THURSDAY...THE SEABREEZE CIRCULATION IS DEVELOPING...
AND WHEN ADDED TO THE BACKGROUND SOUTHWEST WIND WE ARE SEEING
WIDESPREAD GUSTS IN THE 16-19 KNOT RANGE BEING REPORTED. WIND SPEEDS
SHOULD ONLY INCREASE A BIT FURTHER LATER THIS AFTERNOON...BUT SEAS
NOW WILL HAVE TO PLAY "CATCH UP" TO ADJUST TO THESE HIGHER WIND
SPEEDS. LOOK FOR SEAS IN OPEN WATERS TO BUILD TO A SOLID 4 FEET IF
NOT 5 FEET AWAY FROM SHORE. PREVIOUS DISCUSSION FROM 1015 AM
FOLLOWS...
WEST-SOUTHWEST WINDS ARE ALREADY GUSTING TO 20 KNOTS AT THE OCEAN
CREST PIER ON OAK ISLAND...WITH 12-15 KNOTS PREVAILING ELSEWHERE. NO
SIGNIFICANT CHANGES ARE NEEDED TO THE PREVIOUS FORECAST...EXCEPT FOR
LOWERING SEA HEIGHTS BY ABOUT 1 FOOT INITIALLY BASED ON AVAILABLE
BUOY DATA. PREVIOUS DISCUSSION FROM 600 AM FOLLOWS...
A TIGHTER PRESSURE GRADIENT WILL BE REALIZED TODAY INTO THIS EVENING
AS A RATHER IMPRESSIVE TROUGH FOR THIS TIME OF YEAR APPROACHES.
SOUTHWEST SUSTAINED WIND SPEEDS ARE EXPECTED TO REACH 20 KT WITH
GUSTS TO 25 KT. SEAS TODAY ARE EXPECTED TO REACH UP TO 4 TO 5
FT...WITH SOME 6 FT SEAS POSSIBLE ACROSS THE OUTERMOST WATERS LATE
DAY AND THIS EVE. AT THIS TIME...WILL ISSUE A SMALL CRAFT SHOULD
EXERCISE CAUTION HEADLINE. THE FRONTAL ZONE SHOULD BE NEARING THE
WATERS LATE TONIGHT AND EXPECT THE WIND DIRECTION OVERNIGHT WILL
VEER TO A MORE WESTERLY DIRECTION WITH WIND SPEEDS DECREASING TO 10
TO 15 KT.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WESTERLY WINDS WILL BEGIN THE PERIOD AS A
COLD FRONT WAVERS JUST OFF THE COAST. THIS FRONT WILL LIFT SLOWLY
BACK TO THE NORTH DURING FRIDAY...WITH WINDS REMAINING
LIGHT...AROUND 10 KTS...BUT BACKING TO THE SW THROUGH SUNDAY
MORNING. THEREAFTER...WINDS WILL INCREASE THROUGH SATURDAY AS THE
PRESSURE GRADIENT TIGHTENS ABOUT AROUND HIGH PRESSURE RIDGING BACK
TOWARDS THE COAST...WITH SPEEDS RISING FROM THE SW TO AROUND 15 KTS.
SEAS WILL BE 3-4 FT EARLY FRIDAY...AND RISE AGAIN TO 3-4 FT LATE
SATURDAY. IN BETWEEN 1-3 FT SEAS WILL BE COMMON THANKS TO THE
EXTENDED PERIOD OF LIGHTER WINDS.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...HIGH PRESSURE OFFSHORE RIDGING TOWARDS THE
COAST...AND A STRONG COLD FRONT SLOWLY APPROACHING FROM THE
NW...WILL PINCH THE GRADIENT SUNDAY AND MONDAY. THIS DRIVES SW WINDS
UP TO 20 KTS OR MORE BOTH DAYS...AND PUSHES WIND-DRIVEN SEAS UP TO
4-6 FT. AN SCA MAY BE NEEDED FOR AN EXTENDED PORTION OF THIS PERIOD
AHEAD OF THE COLD FRONT WHICH IS PROGGED TO CROSS THE WATERS BY
TUESDAY MORNING.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...JDW
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
540 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 540 PM CDT THU JUL 24 2014
THE 20 UTC AND INCOMING 21 UTC HRRR ITERATIONS HAVE A GOOD HANDLE
ON THE CURRENT CONVECTION ACROSS EASTERN MONTANA...AND WILL LEAN
HEAVILY ON THEIR SOLUTIONS FOR THE REMAINDER OF THE EVENING AND
OVERNIGHT. DID COORDINATE WITH SPC AT 2230 UTC REGARDING A
POTENTIAL EXPANSION OF SEVERE THUNDERSTORM WATCH 439 INTO
SOUTHWEST NORTH DAKOTA AS ROBUST CONVECTION ACROSS SOUTHEAST
MONTANA CONTINUES TO PROPAGATE NORTHEAST. WILL HOLD OFF FOR
NOW AS ALL REPORTS HAVE BEEN SUB-SEVERE. HOWEVER...SHOULD
CONVECTION STRENGTHEN AS IT APPROACHES BAKER...A WATCH EXPANSION
MAY BE NEEDED.
UPDATE ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 540 PM CDT THU JUL 24 2014
STRONG TO SEVERE THUNDERSTORMS ALONG A FRONTAL BOUNDARY ACROSS
EASTERN MONTANA EARLY THIS EVENING WILL CONTINUE TO MOVE EAST INTO
WESTERN AND CENTRAL NORTH DAKOTA LATER THIS EVENING AND INTO THE
OVERNIGHT. VFR CONDITIONS ARE EXPECTED OUTSIDE OF THUNDERSTORMS.
SEE TAF FORECASTS FOR THUNDERSTORM TIMING AND DETAILS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
410 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 410 PM CDT THU JUL 24 2014
SEVERE THUNDERSTORM WATCH 439 HAS BEEN ISSUED FOR NORTHWEST NORTH
DAKOTA THROUGH 03 UTC. PER COORDINATION WITH SPC...SEVERE
CONVECTION ACROSS NORTHWEST NORTH DAKOTA WILL LIKELY HOLD OFF
UNTIL AROUND 00-01 UTC AS STORMS ACROSS NORTH CENTRAL AND NORTHEAST
MONTANA COINCIDENT WITH THE BEST UPPER LEVEL FORCING PROPAGATE
EAST INTO NORTH DAKOTA...CLOSE TO THE 19 UTC HRRR SOLUTION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
SURFACE LOW OVER CENTRAL ALBERTA WITH A TROUGH EXTENDING SOUTHWARD
INTO CENTRAL/EASTERN MONTANA TO THE WYOMING/SOUTH DAKOTA BORDER. AT
UPPER LEVELS...STRONG UPPER LOW OVER CENTRAL ALBERTA WITH SOUTHWEST
FLOW ALOFT AND EMBEDDED SHORTWAVE ENERGY IMPULSES FORECAST TO MOVE
THROUGH THE UPPER LEVEL FLOW. MOST OF THE UPPER LEVEL ENERGY APPEARS
TO BE FOCUSED MORE NORTH OF THE CANADIAN BORDER...BUT PLENTY OF CAPE
AND SHEAR IN PLACE SOUTHWARD ALONG AND AHEAD OF THE SURFACE TROUGH.
MID-LEVEL CAP WAS BUILDING AHEAD OF THE TROUGH...BUT ISOLATED
ELEVATED THUNDERSTORMS HAD DEVELOPED OVER WESTERN NORTH DAKOTA AND
WERE MOVING EAST AT 30-35 MPH...LIKELY ASSOCIATED WITH WEAK UPPER
LEVEL IMPULSES IN THE UPPER FLOW - BUT NOT SURFACE-BASED.
THE MAIN ACTION IS EXPECTED LATER THIS AFTERNOON/EARLY EVENING AS
THE SURFACE TROUGH MOVES INTO WESTERN NORTH DAKOTA...AND INTO
CENTRAL NORTH DAKOTA THROUGH THE EVENING. THIS WILL BE SUPPORTED BY
MORE VIGOROUS UPPER LEVEL IMPULSES. SEVERE STORMS POSSIBLE...BUT
BEST CAPE IS ALONG AND AHEAD OF THE TROUGH...AND THE BEST SHEAR IS
RIGHT ALONG AND BEHIND THE TROUGH.
EXPECTING BEST CHANCES OF THUNDERSTORMS IN THE WEST LATE AFTERNOON
AND EARLY EVENING...AND BEST CHANCES IN THE CENTRAL FROM MID/LATE
EVENING INTO THE EARLY MORNING HOURS.
FRIDAY LOOKS DRY AND BREEZY WEST WINDS WITH HIGHS MAINLY IN THE
UPPER 70S TO MID 80S.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 310 PM CDT THU JUL 24 2014
UPPER LEVEL LOW PROPAGATING EAST ACROSS SOUTH CENTRAL
CANADA...INTO FAR SOUTHEASTERN SASKATCHEWAN BY 12Z SAT...WILL
DRAG A SURFACE COLD FRONT THROUGH THE NORTHERN PLAINS SATURDAY
MORNING...THEN A SECONDARY COLD FRONT SATURDAY AFTERNOON/EVENING
AS THE LOW CONTINUES TOWARDS NORTHWESTERN MN. UPPER LEVEL FORCING
WITH THE LOW COUPLED WITH SFC CONVERGENCE ALONG THE FRONT WILL
BOTH COMBINE WITH LINGERING BOUNDARY LAYER MOISTURE TO RESULT IN
SCATTERED SHOWERS/THUNDERSTORMS ACROSS THE NORTH SAT
MORNING...WITH COVERAGE OF PRECIPITATION SPREADING SOUTHEAST
DURING THE DAY.
SLIGHT CHANCES FOR PRECIPITATION OVER MY FAR EASTERN COUNTIES SAT
NIGHT/SUNDAY WITH THE UPPER LEVEL JET ACROSS THE MIDWEST.
STRONG SURFACE HIGH PRESSURE BUILDS INTO THE REGION SUNDAY/SUNDAY
NIGHT AHEAD OF AN UPPER LEVEL RIDGE OVER THE WESTERN CONUS...THEN
REMAINS QUASI-STATIONARY THROUGH THE DAY TUESDAY GIVING THE
NORTHERN PLAINS REGION A DRY WEATHER SPELL. BOTH THE 12Z GFS/ECMWF
INDICATE RIDGE RIDER S/WVS MOVING THROUGH THE DAKOTAS TUESDAY
NIGHT THROUGH THURSDAY. WITH THE SFC HIGH MOVING SOUTHEAST...WILL
SEE SPOTTY SHOWER/THUNDERSTORM CHANCES BEGINNING MID-WEEK.
TEMPERATURES WILL BE ON THE COOL SIDE FOR THE END OF JULY SAT-
MON...IN THE 70S...THEN WARM INTO THE 80S TUE-THURS WITH THE
BUILDING RIDGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1256 PM CDT THU JUL 24 2014
MVFR CIGS LINGERING FROM KDIK TO KBIS AND KEPT THOSE CIGS IN THE
TAFS UNTIL AROUND 20Z-21Z. OTHERWISE...MAIN HAZARD TO AVIATION WILL
BE THUNDERSTORMS MAINLY IN THE LATTER PART OF THE TAF PERIOD.
MODERATE GUSTY SOUTHEAST WINDS THROUGH THE AFTERNOON AHEAD OF A LOW
PRESSURE TROUGH/FRONT THAT IS FORECAST TO ENTER FAR WESTERN NORTH
DAKOTA AROUND 22Z-00Z...THEN MOVE EAST TO KMOT/KBIS AROUND 06Z...AND
TO KJMS AROUND 09Z-12Z. THERMAL CAP AHEAD OF THE TROUGH...BUT ALONG
AND BEHIND IT THUNDERSTORM CHANCES INCREASE...ESPECIALLY ACROSS
NORTHERN ND AT KISN/KMOT. STRONG WINDS AND LARGE HAIL THE MAIN
THREAT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...NH
AVIATION...JV
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
142 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...SEE NO NEED TO CHANGE MUCH IN THE VERY NEAR TERM. SBCIN
OVER THE PIEDMONT IS GONE AND CAPES ARE AROUND 2500J AND WE ARE
BEGINNING TO SEE MORE CONVECTIVE DEVELOPMENT...SO SCT-NUMEROUS
SHOWERS/THUNDERSTORMS SHOULD OCCUR BEFORE 00Z. SFC-6KM BULK SHEAR
GENERALLY IN THE 25-30KT RANGE...SO A FEW SEVERE STORMS ARE IN THE
OFFING. ADJUSTED MOST FIELDS WITH LATEST CONSSHORT RUN.
AS OF 1020 AM...14Z SFC MAP INDICATES THAT THE COLD FRONT IS STILL
WEST OF THE NC MOUNTAINS FROM FAR SW VA THROUGH EASTERN TN. AS USUAL
THE FRONTAL PASSAGE WILL BECOME MUDDLED AS IT MOVES ACROSS THE
MOUNTAINS. LOOKS LIKE THE LEE TROUGH WILL BECOME A PLAYER THIS
AFTERNOON WITH ITS LOW LEVEL CONVERGENCE TRIGGERING STORMS. THE
ACTUAL FRONT MAY NOT MAKE IT THROUGH THE AREA UNTIL THIS EVENING. IN
ANY EVENT...CURRENT SPC MESO-ANAL SHOWS PLENTY OF CAPE POOLING
ACROSS THE PIEDMONT ALREADY LATE THIS MORNING WITH SBCAPE VALUES
ALREADY OVER 2000J. CURRENT SBCIN SHOULD DISSIPATE AS BOUNDARY LAYER
CONTINUES TO WARM. HENCE...SCT-NUMEROUS THUNDERSTORMS STILL LOOK
GOOD FOR THE AFTERNOON. SPC HAS UPGRADED OUR EASTERN AREAS TO A
SLIGHT RISK. CAN`T ARGUE WITH IN THAT THERE IS A DCAPE GRADIENT IN
THAT REGION AND 0-6KM SHEAR HAS INCREASED TO 20-30KTS. HENCE...A FEW
SEVERE STORMS ARE LIKELY. ADJUSTED MOST FIELDS BASED ON LATEST
CONSSHORT RUN AND TRENDS. THAT YIELDED MAX TEMPS A COUPLE DEGREES
LOWER AS CLOUD COVER SLOWING THE TEMP RISE.
PREVIOUS DISCUSSION:
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...A COLD FRONT APPROACHING ALONG WITH AN UPPER TROUGH SHOULD
TRIGGER NUMEROUS SHOWERS/THUNDERSTORMS NEAR AND/OR OVER THE AIRFIELD
THIS AFTERNOON. HENCE...HAVE A TEMPO FOR TSRA WITH RESTRICTIONS AND GUSTY
WINDS UNTIL 23Z. THINGS WILL CALM DOWN OVERNIGHT. HOWEVER...MOST
GUIDANCE SUGGESTS THAT MVFR CLOUDS WILL DEVELOP TOWARD SUNRISE WITH
SOME LIGHT FOG. THIS SHOULD DISSIPATE BY 14Z.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE THUNDERSTORMS WITH
RESTRICTIONS AND GUSTY WINDS THIS AFTERNOON AS A COLD FRONT MOVES
INTO THE AREA. THE STORMS WILL MOVE OUT OF THE AREA THIS EVENING.
THE OVERNIGHT WILL QUIET DOWN BUT SOME IFR FOG IS A GOOD BET AT KAVL
WHERE CROSS OVER OVER TEMP WILL BE MET.
OUTLOOK...FRI NIGHT THROUGH SUNDAY MORNING SHOULD BE QUIET AND
VFR...EXCEPT FOR THE MTN VALLEYS WHERE EARLY MORNING FOG MAY OCCUR.
THUNDERSTORMS WILL RETURN TO THE FORECAST FOR SUNDAY AFTERNOON
THROUGH MON AS ANOTHER COLD FRONT APPROACHES AND THEN MOVES THROUGH
THE AREA ON MON.
CONFIDENCE TABLE...
17-23Z 23-05Z 05-11Z 11-17Z
KCLT HIGH 100% HIGH 85% HIGH 84% MED 69%
KGSP HIGH 95% HIGH 93% HIGH 100% HIGH 100%
KAVL HIGH 85% HIGH 83% MED 64% HIGH 88%
KHKY HIGH 84% HIGH 93% HIGH 100% HIGH 100%
KGMU HIGH 95% HIGH 93% HIGH 100% HIGH 100%
KAND HIGH 100% HIGH 100% HIGH 100% MED 75%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...LG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1238 PM EDT THU JUL 24 2014
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST THIS MORNING AND
SHOULD MOVE ACROSS THE CAROLINAS AND NORTH GEORGIA THIS AFTERNOON
AND EVENING. HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT FOR FRIDAY
AND THE WEEKEND. ANOTHER FRONT IS EXPECTED TO PASS ON MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AT 1230 PM...SEE NO NEED TO CHANGE MUCH IN THE VERY NEAR TERM. SBCIN
OVER THE PIEDMONT IS GONE AND CAPES ARE AROUND 2500J SO WE ARE
BEGINNING TO SEE MORE CONVECTIVE DEVELOPMENT...SO SCT-NUMEROUS
SHOWERS/THUNDERSTORMS SHOULD OCCUR BEFORE 00Z. SFC-6KM BULK SHEAR
GENERALLY IN THE 25-30KT RANGE...SO A FEW SEVERE STROMS ARE IN THE
OFFING. ADJUSTED MOST FIELDS WITH LATEST CONSSHORT RUN.
AS OF 1020 AM...14Z SFC MAP INDICATES THAT THE COLD FRONT IS STILL
WEST OF THE NC MOUNTAINS FROM FAR SW VA THROUGH EASTERN TN. AS USUAL
THE FRONTAL PASSAGE WILL BECOME MUDDLED AS IT MOVES ACROSS THE
MOUNTAINS. LOOKS LIKE THE LEE TROUGH WILL BECOME A PLAYER THIS
AFTERNOON WITH ITS LOW LEVEL CONVERGENCE TRIGGERING STORMS. THE
ACTUAL FRONT MAY NOT MAKE IT THROUGH THE AREA UNTIL THIS EVENING. IN
ANY EVENT...CURRENT SPC MESO-ANAL SHOWS PLENTY OF CAPE POOLING
ACROSS THE PIEDMONT ALREADY LATE THIS MORNING WITH SBCAPE VALUES
ALREADY OVER 2000J. CURRENT SBCIN SHOULD DISSIPATE AS BOUNDARY LAYER
CONTINUES TO WARM. HENCE...SCT-NUMEROUS THUNDERSTORMS STILL LOOK
GOOD FOR THE AFTERNOON. SPC HAS UPGRADED OUR EASTERN AREAS TO A
SLIGHT RISK. CAN`T ARGUE WITH IN THAT THERE IS A DCAPE GRADIENT IN
THAT REGION AND 0-6KM SHEAR HAS INCREASED TO 20-30KTS. HENCE...A FEW
SEVERE STORMS ARE LIKELY. ADJUSTED MOST FIELDS BASED ON LATEST
CONSSHORT RUN AND TRENDS. THAT YIELDED MAX TEMPS A COUPLE DEGREES
LOWER AS CLOUD COVER SLOWING THE TEMP RISE.
PREVIOUS DISCUSSION:
AS OF 330 AM...RECENT REGIONAL RADAR INDICATED THAT THE CONVECTION
ACROSS EASTERN TN HAS DECREASED TO ISO SHOWERS...WITH A SECONDARY
PATCH OF SHOWERS ACROSS THE SOUTHERN I-77 CORRIDOR. W/V SHOWED THE
MID LEVEL TROF AXIS WAS LOCATED ACROSS EASTERN KY/TN...SWEEPING
EAST. AT 330 AM...W/V AND RAP INDICATED THAT SEVERAL S/W EXISTED EAST
OF THE TROF AXIS...WITH STRONGER S/W ACROSS THE WESTERN OHIO RIVER
VALLEY. I ANTICIPATE THAT WIDELY SCT TO SCT SHRA WILL DRIFT OR
DEVELOP ACROSS NC MTNS EARLY THIS MORNING. BY MID DAY...THE MID
LEVEL TROF IS EXPECTED TO RIPPLE OVER THE SOUTHERN APPALACHIAN
REGION. BY 17Z...FORECAST SOUNDINGS INDICATE THAT CAPES WILL RANGE
BETWEEN 1000-1500 J/KG ACROSS THE REGION. AS WEAK MID LEVEL FORCING
REACHES THE MTNS AND FOOTHILLS EARLY THIS AFTERNOON...CONVECTION
SHOULD DEVELOP ACROSS THE EAST FACING SLOPES AND FOOTHILLS. FORECAST
SOUNDINGS INDICATE THAT THE STEERING FLOW WILL PUSH CELLS NW TO SE
ACROSS THE WESTERN CAROLINAS AND NE GEORGIA. SHEAR MAY REMAIN WEAK
THROUGH THIS AFTERNOON...BUT POSSIBLY ENOUGH TO ORGANIZE CONVECTION
INTO A BAND. ONCE DEVELOPED...THE BAND SHOULD SLIDE
QUICKLY EAST...REACHING THE CLT AREA BY LATE AFTERNOON. THESE STORMS
MAY RESULT IN STRONG TO SEVERE TSRA WIND GUSTS ACROSS PORTIONS OF
THE OF THE FORECAST AREA. IN ADDITION...DCAPE ACROSS THE EASTERN
PIEDMONT MAY RANGE FROM 500-1000 J/KG. WE WILL HIGHLIGHT IN THE HWO
THE POTENTIAL FOR DAMAGING WIND GUSTS ASSOCIATED WITH THE FORECAST
THUNDERSTORM BAND. HIGH TEMPERATURES MAY RANGE FROM 80 WITHIN THE
MTN VALLEYS NEAR 90 EAST OF I-85.
THIS EVENING...CONVECTION WILL PROPAGATE EAST...EXITING THE CWA
EARLY THIS EVENING. OVERNIGHT...CONDITIONS WILL DRY WITH CLOUD COVER
DECREASING FROM WEST TO EAST. LOW TEMPERATURES MAY RANGE 2-3 DEGREES
COOLER THAN THIS MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...THE SHORT RANGE IS SHAPING UP TO BE
RELATIVELY QUIET. THE FRONT SHOULD BE DRIVEN FAR ENOUGH S TO NOT
AFFECT THE REGION ON FRIDAY. THE UPPER TROF OVER THE EAST SHOULD
PULL OUT OR FILL A BIT ON FRIDAY INTO SATURDAY WITH WEAK SURFACE
HIGH PRESSURE MOVING OVER THE REGION. THE MODELS CONTINUE TO
ALTERNATELY DEPICT ISOLATED/WIDELY SCATTERED SHOWER DEVELOPMENT
DURING HEATING ON FRIDAY AND SATURDAY...BUT THE SITUATION DOES NOT
APPEAR TO HAVE A WHOLE LOT GOING FOR IT AS MOISTURE SHOULD BE MUCH
LESS THAN THE LAST WEEK. A FEW SHORT WAVES WILL MOVE ACROSS THE
REGION BUT THE MODELS DO NOT RESPOND TO ANY GREAT DEGREE. AT THIS
POINT...WOULD PREFER TO REMAIN OPTIMISTIC FOR THE FIRST PART OF THE
WEEKEND AND HAVE KEPT THE FCST DRY. ANY BRIEF DROP IN TEMPS ON
FRIDAY WILL BE WIPED OUT FOR SATURDAY AS THE AIR MASS MODIFIES BACK
TO NORMAL. TOWARD THE END OF THE PERIOD...THERE IS SOME POTENTIAL
FOR AN MCS OR REMNANTS TO APPROACH FROM THE W OR NW...SO A SMALL POP
WAS INTRODUCED ON THE TN BORDER.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AS OF 330 AM THURSDAY...THE MEDIUM RANGE HAS PERHAPS A BIT MORE
UNCERTAINTY THROWN IN FOR SUNDAY AND MONDAY. THE RETURN MOISTURE
DOES NOT APPEAR TO BE AS GREAT ON SUNDAY AND ANY UPPER SUPPORT FOR
CONVECTION SHOULD MOVE PAST TO THE NORTH...TO THE POINT WHERE THE
GFS/ECMWF BOTH FAIL TO DEVELOP MUCH IN THE WAY OF PRECIP. AT THE
SAME TIME...THE MODELS CONTINUE TO SUGGEST SOME SORT OF MCS
ACTIVITY...BUT KEEP IT MOVING ACROSS THE OH VALLEY/CENTRAL
APPALACHIANS. THERE IS THE POTENTIAL FOR A BOUNDARY TO MOVE DOWN
FROM THAT ACTIVITY WHICH COULD TRIGGER SOME STORMS. WILL NOT MAKE
ANY CHANGES TO THE PRECIP PROBS FOR SUNDAY...BUT KEEP IN MIND THE
TREND IS FOR LESS ACTIVITY ON THAT DAY. THE MODELS CONTINUE TO
DEEPEN THE UPPER TROF OVER THE EAST AGAIN ON MONDAY WITH STRONGER
WAVES DRIVING ANOTHER SURFACE COLD FRONT SE ACROSS THE REGION...MOST
LIKELY ON MONDAY. IN SPITE OF THIS BOUNDARY BEING MORE SIGNIFICANT
IN TERMS OF AIR MASS CHANGE...THE MODEL RESPONSE IS UNDERWHELMING IN
TERMS OF PRECIP. AGAIN...WILL NOT MAKE ANY CHANGES...BUT A DOWNWARD
TREND MIGHT BE STARTED LATER TODAY. STILL LOOKS BELOW NORMAL FOR THE
MIDDLE OF NEXT WEEK AS A SURFACE HIGH OF CONTINENTAL ORIGIN DROPS
DOWN FROM CANADA/NRN PLAINS. HAVE NUDGED TEMPS/DEWPTS DOWN A BIT
MORE FOR TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...THE PRIMARY FORECAST CHALLENGE WILL BE THE TIMING OF
AFTERNOON TSRA. THE 4KM WRF AND 6Z NAM12 INDICATES THAT CONVECTION
WILL DEVELOP ACROSS THE NC FOOTHILLS BETWEEN 18Z-19Z...FORMING A
BAND. STEERING FLOW AND COLD POOL GENERATION SHOULD RESULT IN THE
BAND TO MOVE BRISKLY EAST DURING THE AFTERNOON...LIKELY PASSING
ACROSS THE CLT METRO AREA BETWEEN 20Z TO 22Z. I WILL HIGHLIGHT THE
TSRA POTENTIAL WITH A TEMPO GROUP FROM 21Z TO 24Z. ALTHOUGH FROPA
SHOULD OCCUR BETWEEN 18Z-0Z...LIGHT NORTH WINDS ARE NOT FORECAST TO
DEVELOP UNTIL THIS EVENING. THE COMBINATION OF LIGHT NORTH
WINDS...LINGERING MID LEVEL CLOUD COVER...AND 2-3 DEGREE DEWPOINT
DEPRESSIONS SHOULD FAVOR VFR CONDITIONS TONIGHT.
ELSEWHERE...ALL TERMINALS WILL LIKELY SEE CONVECTION EITHER OVER THE
TERMINAL OR VICINITY THROUGH 0Z. I WILL HIGHLIGHT THE CONVECTIVE
PERIOD WITH VCTS OR TEMPO GROUPS...GENERALLY BETWEEN 19Z-22Z. AHEAD
OF THE COLD FRONT FLOW WILL REMAIN FROM THE SOUTHWEST BETWEEN
5-10KTS. WINDS WILL VEER FROM THE NORTH THIS EVENING. KAVL COULD SEE
NNW WINDS DEVELOP THIS MORNING...REMAINING THROUGH THE REST OF THE
12Z PACKAGE. NAM CONDENSATION PRESSURE DEFICITS AND MOS INDICATES
THAT KAVL COULD SEE IFR CEILINGS DURING THE PRE DAWN HOURS FRI.
OUTLOOK...FRI AND SAT SHOULD BE QUIET AND VFR...EXCEPT FOR THE MTN
VALLEYS WHERE EARLY MORNING FOG MAY OCCUR. THUNDERSTORMS WILL RETURN
TO THE FORECAST FOR SUNDAY AFTERNOON THROUGH MON AS ANOTHER COLD
FRONT APPROACHES AND THEN MOVES THROUGH THE AREA ON MON.
CONFIDENCE TABLE...
16-22Z 22-04Z 04-10Z 10-16Z
KCLT HIGH 100% HIGH 100% HIGH 100% MED 72%
KGSP HIGH 100% HIGH 100% HIGH 100% HIGH 89%
KAVL HIGH 100% HIGH 96% MED 70% HIGH 83%
KHKY HIGH 100% HIGH 100% HIGH 88% MED 63%
KGMU HIGH 100% HIGH 100% HIGH 100% HIGH 89%
KAND HIGH 100% HIGH 100% HIGH 100% MED 72%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...PM
NEAR TERM...LG
SHORT TERM...PM
LONG TERM...PM
AVIATION...NED
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1228 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1121 AM CDT THU JUL 24 2014
HAVE TWEAKED POPS THIS MORNING AND RAISED THEM IN EAST CENTRAL SD...
SOUTHEASTWARD INTO PARTS OF SOUTHWEST MN AND NORTHWEST IA
ACCOUNTING FOR THE CURRENT CLUSTER OF ELEVATED STORMS MOVING
THROUGH. A FEW CELLS GET A BIT ANGRY ALOFT...BUT THEN CORES
COLLAPSE SO THUS ONLY ONE WARNING SO FAR. THE CELLS ARE ROOTED
NEAR 750MB SO THE WIND SHEAR IN MOST OF THE LOWEST 2KM IS NOT
BEING TAPPED. BUT THEY ARE HOLDING TOGETHER ALONG POSITIVE THETAE
ADVECTION AND WILL CERTAINLY IMPACT SOUTHWEST MN AND FAR NORTHWEST
IA THROUGH EARLY AFTERNOON. MORE UNCERTAIN IS WHAT THE CLUSTER IN
EASTERN ND AND EXTREME NORTHEAST SD WILL DO. HAD TO KEEP SOME
DECENT POPS GOING IN SOUTHWEST MN FOR THE MID AFTERNOON HOURS AND
MAY HAVE TO RAISE THEM IF THAT ACTIVITY HOLDS TOGETHER. HIGHS
STILL LOOK VERY WARM IN OUR FAR WEST...COOLING TO AROUND THE UPPER
70S TO NEAR 80 IN OUR EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1220 PM CDT THU JUL 24 2014
OVERALL...VFR WILL PREVAIL FOR MOST AREAS THROUGH THE TAF PERIOD
ENDING AT 18Z FRIDAY. BUT THUNDERSTORMS MOVING SOUTHEASTWARD
ACROSS AREAS EAST OF THE JAMES RIVER VALLEY WILL CERTAINLY NEED
WATCHED INTO LATE THIS AFTEROON AND EVENING...AS A STOUT LOW LEVEL
JET REMAINS JUXTAPOSED RIGHT IN THIS AREA. THIS WILL GIVE THE
POSSIBILITY OF CONTINUED SCATTERED REDEVELOPMENT. FOR NOW...THIS
IS VERY DIFFICULT TO TIME SO LEFT OUT OF THE THREE TAF SITES THE
MENTION OF TSRA. KFSD MAY BE THE MOST IMPACTED BY THIS SCENARIO SO
DO NOT BE SURPRISED IF YOU SEE AMENDMENTS INVOLVING CONVECTION.
BUT ALSO NEED TO KEEP A CLOSE EYE ON KSUX FOR REDEVELOPMENT BUT
MUCH OF THEIR ACTIVITY MAY STAY TO THE NORTH AND EAST. KHON MAY
ALSO SEE MOST OF THEIR ACTIVITY OFF TO THE EAST. SO MOST CONCERNED
ABOUT KFSD THROUGH THE EVENING. IN ANY STRONG STORMS...BRIEF HAIL
AND MVFR CONDITIONS ARE POSSIBLE. LATE TONIGHT AND FRIDAY
MORNING...IT IS EXPECTED THAT THE CONVECTION WILL STAY NORTH OF
OUR AREA. CONCERNING WINDS...EXPECT FREQUENT GUSTS FROM THE SOUTH
AND SOUTHEAST ALONG AND EAST OF THE JAMES RIVER VALLEY THIS
AFTERNOON OF AROUND 25 TO 30 KNOTS. FURTHERMORE...A STRONG LOW
LEVEL JET WILL EXIST FOR MUCH OF THE AREA TONIGHT...SOME OF WHICH WILL
TRANSLATE DOWN TO THE SURFACE. BUT FOR NOW LEFT THE MENTION OF NON
CONVECTIVE LOW LEVEL WIND SHEAR OUT OF THE TAFS BECAUSE SURFACE
SPEEDS MAY BE STRONG ENOUGH TO PRECLUDE THE MENTION OF IT.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1121 AM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 1121 AM CDT THU JUL 24 2014
HAVE TWEAKED POPS THIS MORNING AND RAISED THEM IN EAST CENTRAL SD...
SOUTHEASTWARD INTO PARTS OF SOUTHWEST MN AND NORTHWEST IA
ACCOUNTING FOR THE CURRENT CLUSTER OF ELEVATED STORMS MOVING
THROUGH. A FEW CELLS GET A BIT ANGRY ALOFT...BUT THEN CORES
COLLAPSE SO THUS ONLY ONE WARNING SO FAR. THE CELLS ARE ROOTED
NEAR 750MB SO THE WIND SHEAR IN MOST OF THE LOWEST 2KM IS NOT
BEING TAPPED. BUT THEY ARE HOLDING TOGETHER ALONG POSITIVE THETAE
ADVECTION AND WILL CERTAINLY IMPACT SOUTHWEST MN AND FAR NORTHWEST
IA THROUGH EARLY AFTERNOON. MORE UNCERTAIN IS WHAT THE CLUSTER IN
EASTERN ND AND EXTREME NORTHEAST SD WILL DO. HAD TO KEEP SOME
DECENT POPS GOING IN SOUTHWEST MN FOR THE MID AFTERNOON HOURS AND
MAY HAVE TO RAISE THEM IF THAT ACTIVITY HOLDS TOGETHER. HIGHS
STILL LOOK VERY WARM IN OUR FAR WEST...COOLING TO AROUND THE UPPER
70S TO NEAR 80 IN OUR EAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 420 AM CDT THU JUL 24 2014
FAIRLY SHARP RIDGE WITH AXIS JUST EAST OF THE ROCKIES EARLY THIS
MORNING. ON WATER VAPOR LOOP...CAN SEE SEVERAL WAVES ROTATING
THROUGH THE RIDGE...ALL RIDING ON THE EDGE OF A FAIRLY STRONG MID
LEVEL FRONTAL BOUNDARY. STRONGEST WAVE BACK OVER PAC NW...BUT ONE
NICE WAVE PUSHING FROM ERN MT INTO WRN ND. PATCHY CLOUDS IN THE
9-10 KFT RANGE HAVE DEVELOPED FROM SOUTH CENTRAL ND TOWARD
SOUTHEASTERN SD...AND INCREASING LOW LEVEL JET WINDS ON MRR
PROFILER. ALL RECENT RUNS OF HRRR AND WRF-ARW HAVE BEEN FAIRLY
INSISTENT ON DEVELOPMENT OF CONVECTION OVER THE NEXT COUPLE HOURS
FROM 09Z-11Z OUT FROM THE JAMES VALLEY WESTWARD...AND MOST SOLUTION
HAVE AT LEAST SOME DEVELOPMENT OCCURRING THIS MORNING. GIVEN A DECENT
MID LEVEL THETA E ADVECTION FOCUS...AND MID LEVEL FRONTOGENETIC
AXIS...SEEMS WOULD BE FAVORED FOR A FEW STORMS DEVELOPING THIS
MORNING. HOWEVER...WILL BE INCREASINGLY DIFFICULT FOR ACTIVITY TO
BUILD EASTWARD AS FORCING WITH WEAK MID LEVEL WAVES DROPS SOUTHEAST
MOST LIKELY LOCATION FOR CONVECTION LOOKS TO BE THE MID TO SOUTHERN
JAMES VALLEY THEN SOUTHEAST TOWARD KSUX AREA DURING THE MORNING
HOURS. BY AFTERNOON...CONTINUED BUILDING HEIGHTS AND WARMING TEMPS
ALOFT AS WAVE MOVES PAST WILL START TO WEAR ON CONVECTIVE THREAT
WITH COVERAGE EXPECTED TO DWINDLE AS BUILDS EAST.
WITH ELEVATED INSTABILITY PERHAPS AS HIGH AS 1000 J/KG AND 2-6KM
SHEAR OF 30-40 KNOTS...POTENTIAL IS THERE FOR SOME ORGANIZED STORM
DEVELOPMENT AND UPDRAFT HELICITY ON HRRR INDICATES SOME NEED FOR
CONCERN FOR MARGINALLY SEVERE HAIL WITH ANY STRONGER STORMS THROUGH
AT LEAST MID TO LATE MORNING.
A PRETTY SHARP GRADIENT WILL AGAIN TODAY BE PRESENT BETWEEN WARM AND
HUMID LESS MIXED CONDITIONS...WITH A HOT...DRY...AND MORE MIXED
AIRMASS... LIKELY TO REMAIN JUST WEST OF THE CWA. HAVE RAISED TEMPS
MANY AREAS BY A COUPLE DEGREES...WITH MAINLY 80S...BUT SOME UPPER
70S IN MORE PERSISTENT CLOUDS/POTENTIAL PRECIP AXIS. HAVE LOWER 90S
CRAWLING BACK INTO THE WEST...AND WITH RECENT DRY CONDITIONS AND
WINDS GUSTING 25 TO 35 MPH...WILL START TO BRING A BIT MORE CONCERN
TO FIRE BEHAVIOR...BUT STARTS WILL STILL BE VERY DIFFICULT WITH
DEWPOINTS IN THE MID TO UPPER 60S HOLDING BACK TO LOWER BRULE AREA.
NOT BUYING IN TO DEVELOPMENT OF COMPLEX OF STORMS TONIGHT ACROSS
SOUTHEAST SOUTH DAKOTA...WHICH WOULD ALMOST REQUIRE THAT DEVELOPMENT
TO STORMS OCCURS BACK TO THE WEST WHERE TERRAIN/CONVERGENCE WOULD
HAVE A BETTER CHANCE TO OVERCOME THE MASSIVE WARM LAYER ALOFT /+15
TO +16 C AT 700 HPA/ BY EVENING. RETAINED A LOW POPS DURING THE
EVENING IN THE EVENT OF OUTSIDE CHANCE DEVELOPMENT CAN EVOLVE TOWARD
MORE ELEVATED AS SPREADS EAST. A MUCH BETTER CHANCE THAT A MORE
ORGANIZED COMPLEX WILL TAKE SHAPE JUST NORTH AND EAST OF THE CWA...
WITHIN WARM ADVECTION ZONE AHEAD OF LOW PRESSURE PUSHING INTO THE
EASTERN DAKOTAS...WITH PERHAPS A SCATTERED TO LOW LIKELY CHANCE BY
LATER EVENING AND EARLY OVERNIGHT IN EASTERN PARTS OF SW MN/NW IA.
FAIRLY SOUTH SOUTHERLY GRADIENT AND VERY WARM AIRMASS WAS CONVINCING
ENOUGH TO RAISE OVERNIGHT LOWS A FEW DEGREES.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 420 AM CDT THU JUL 24 2014
EXPECT CONVECTIVE ACTIVITY TO PRETTY MUCH BE EAST OF OUR CWA AFTER
12Z FRIDAY. SHOULD THUS BE A PARTLY TO MOSTLY SUNNY SKY...WITH JUST
SOME CUMULUS POSSIBLE. WILL HAVE QUITE A BIT OF INSTABILITY...BUT A
STRONG INVERSION ALOFT WILL KEEP US CAPPED. MODEL THERMAL FIELDS
HAVE A DECENT SPREAD...BUT OVERALL HAVE SHOWN A WARMING TREND ON
RECENT RUNS. A BIT CONCERNED THAT THE STRONG INVERSION ALOFT AND
DECENT LOW LEVEL MOISTURE OF 60S AND 70S DEWPOINTS...WILL PREVENT US
FROM FULLY MIXING...ESPECIALLY ACROSS OUR EASTERN AREAS. SO DID GO
AHEAD AND WARM HIGHS A FEW DEGREES ACROSS THE BOARD INTO THE MID 80S
AND LOW 90S...BUT DID NOT GO TOO EXTREME YET. WILL HAVE TO MONITOR
THOUGH...AS FULL MIXING WOULD RESULT IN HIGHS A FEW DEGREES WARMER
THAN CURRENTLY FORECAST. THIS SEEMS MOST PROBABLE WEST OF INTERSTATE
29...AND THINKING WE MAY NEED TO WARM THAT AREA UP ON FUTURE
FORECASTS IF TRENDS CONTINUE.
CONVECTIVE ACTIVITY MAY BECOME MORE ACTIVE FRIDAY NIGHT INTO
SATURDAY MORNING. A STRONG MID AND UPPER JET WILL PUSH ACROSS THE
NORTHERN PLAINS...ACCOMPANIED BY PRETTY GOOD PV ADVECTION AS WELL.
THIS LARGE SCALE FORCING WILL INTERACT WITH A LOW LEVEL BOUNDARY AND
EASTERLY UPSLOPE FLOW ACROSS CENTRAL SOUTH DAKOTA. THUS THINKING IS
WE MAY SEE AN AREA OF ELEVATED CONVECTION FORM...WITH STORM MOTIONS
TAKING THIS ACTIVITY EAST SOUTHEAST INTO OUR CWA. ACTUALLY PRETTY
GOOD AGREEMENT BETWEEN THE ECMWF...NAM AND SREF ON THIS SOLUTION.
GFS IS A DRY OUTLIER...AND SEEMS TO REPRESENT A LESS LIKELY
SOLUTION. THUS DID GO AHEAD AND INCREASE POPS...MOVING INTO SOUTH
CENTRAL SOUTH DAKOTA AFTER MIDNIGHT...PUSHING TOWARDS THE INTERSTATE
29 CORRIDOR THROUGH THE MORNING. AMOUNT OF INSTABILITY AVAILABLE TO
THIS ELEVATED PARCEL REMAINS UNCERTAIN...BUT COULD END UP AROUND OR
JUST ABOVE 1000 J/KG. GIVEN THE STRONG JET...SPEED SHEAR SHOULD BE
PRETTY GOOD. THUS SHOULD STORMS FORM...AT LEAST SOME SEVERE HAIL
THREAT WOULD SEEM TO EXIST...POSSIBLY A WIND THREAT TOO WITH THE DRY
SUB CLOUD LAYER POSSIBLY HELPING ORGANIZE STORMS ALONG AN OUTFLOW.
THESE ELEVATED NOCTURNAL THUNDERSTORMS ARE TOUGH TO
FORECAST...THUS CONFIDENCE ON EVOLUTION REMAINS LOW...BUT
SOMETHING TO KEEP AN EYE ON.
EXPECT ANY CONVECTION WOULD EXIT THE AREA BY AFTERNOON...GIVING WAY
TO PARTLY TO MOSTLY SUNNY SKIES. TEMPERATURE FORECAST PROBABLY A BIT
LOWER CONFIDENCE THAN NORMAL DUE TO DIFFERENCES IN HOW MODELS HANDLE
MORNING CONVECTION AND DEBRIS CLOUDS. FOR NOW STAYED NEAR CONSENSUS
OF LOW TO MID 80S...BUT WOULD EXPECT ADJUSTMENTS UP OR DOWN A FEW
DEGREES MAY VERY WELL BE NEEDED AS WE GET CLOSER. A STRONG UPPER
WAVE WILL DIVE SOUTHEAST OUT OF CANADA INTO THE GREAT LAKES
REGION...PUSHING A COLD FRONT THROUGH OUR AREA BY SUNDAY. THIS WILL
RESULT IN A COOLER END TO THE WEEKEND. LOOKING AT MID 70S TO AROUND
80 ON SUNDAY...WITH BLUSTERY NORTHWESTERLY WINDS GUSTING AROUND 30
MPH.
THIS COOLER AND DRIER AIR IS EXPECTED TO CONTINUE INTO THE MIDDLE OF
NEXT WEEK AS THE PATTERN BECOMES MORE STAGNANT...WITH A DEEP TROUGH
OVER THE EASTERN USA AND RIDGE OVER THE WEST. APPEARS WE WILL STAY
ON THE COOLER SIDE OF THINGS...WITH THE RIDGING UNABLE TO BUILD FAR
ENOUGH EAST. THUS TEMPERATURES SHOULD STAY SEVERAL DEGREES BELOW
NORMAL THROUGH MID WEEK...WITH HIGHS IN THE 70S AND 80S AND LOWS IN
THE 50S AND 60S. NOT MUCH FORCING...BUT MOISTURE INCREASES
ENOUGH...THAT COMBINED WITH THE COOL TEMPERATURES ALOFT...WE MAY BE
ABLE TO GENERATE ENOUGH INSTABILITY FOR A FEW DIURNALLY DRIVEN SHOWERS
AND STORMS BY WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 646 AM CDT THU JUL 24 2014
AN AREA OF SCATTERED THUNDERSTORMS WILL PUSH OUT OF THE KHON AREA
BY 13Z-14Z...AND MOVE TO IMPACT THE KFSD AND KSUX TAF SITE LATER
ON IN THE MORNING BETWEEN 13Z-17Z. A HEAVIER CORE IN STORMS WILL
LIKELY TAKE VISIBILITY TO MVFR...OTHERWISE VFR CONDITIONS ARE
EXPECTED WITH THE HIGH BASED STORMS. A FEW STORMS MAY ALSO PRODUCE
SOME SMALL HAIL. SURFACE SOUTHEAST TO SOUTH WINDS WILL INCREASE
AND WILL RESULT IN SOME STRONGER WIND GUSTS ABOVE 25 KNOTS DURING
THE MIDDAY AND AFTERNOON HOURS. IF WINDS DECOUPLE MORE THAN
EXPECTED TONIGHT...THERE COULD BE SOME LOW LEVEL WIND SHEAR FOR
KFSD OR KSUX. ANOTHER ELEMENT TO WATCH IS THE HIGH MOISTURE
CONTENT OF THE AIR...WHICH MAY ALSO LEAD TO A POTENTIAL FOR A
BRIEF PERIOD OF MVFR VISIBILITIES AROUND KSUX OF KFSD LATE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
UPDATE...MJ
SHORT TERM...CHAPMAN
LONG TERM...CHENARD
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
122 PM CDT THU JUL 24 2014
.UPDATE...
JUST SENT A QUICK UPDATE TO LOWER POPS IN THE EAST FOR THE
AFTERNOON AND RE-CONFIGURE THE POP GRADIENT OVER THE HILL COUNTRY
BASED ON CURRENT RADAR/SATELLITE TRENDS AND RECENT ANALYSES OF
CONVECTIVE INSTABILITY.
&&
.PREV DISCUSSION... /ISSUED 1244 PM CDT THU JUL 24 2014/
UPDATE...18Z AVIATION BELOW.
AVIATION...A MID LEVEL DISTURBANCE IS CONTRIBUTING TO CHANCES FOR
SHRA AND TSTMS TODAY ACROSS SOUTH-CENTRAL TEXAS. COVERAGE HAS
DIMINISHED OVER THE PAST 2 HOURS ALONG AND EAST OF THE I-35
CORRIDOR...WITH NOW JUST A LONE TSTM NORTH OF AUS MOVING SW INTO
THE HILL COUNTRY. LATEST HI RESOLUTION RUNS OF HRRR AND TTECH SEEM
TO HAVE SLIGHTLY BETTER HANDLE ON TRENDS...ALTHOUGH NOT PERFECT...
AND SHOW ISOLD CONVECTION DEVELOPING MID AFTERNOON THROUGH SUNSET
ALONG AND SOUTH OF I-10...WITH BEST CHANCES TO MENTION VCSH IN
TAF AT DRT. SHRA/TSTMS SHOULD END AFTER SUNSET. OUTSIDE OF
PRECIP...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION THIS
AFTERNOON AND EVENING.
PREV DISCUSSION... /ISSUED 919 AM CDT THU JUL 24 2014/
UPDATE...
JUST SENT A MAJOR UPDATE TO THE FORECAST FOR THE REMAINDER OF THE
DAY THROUGH 02Z THIS EVENING. IN SHORT...THE MCS THAT DEVELOPED
OVER OKLAHOMA/ARKANSAS YESTERDAY HELD TOGETHER ENOUGH TO BRING
SHOWERS TO LOCATIONS ALONG AND NORTH OF INTERSTATE 10 THIS
MORNING. A SECOND AREA OF STRONGER STORMS HAS DEVELOPED IN THE
BRENHAM AREA. THIS LATTER AREA OF STORMS MATCHES WELL WITH THE
TTECH AND CSU WRF RUNS...AND TO A LESSER EXTENT WITH THE HRRR.
THUS...WE EXPECT THIS AREA TO GROW IN SIZE AND BEGIN MOVING NEARLY
DUE WEST ALONG WITH THE GENERAL MOTION OF THE REMNANT FROM A TUTT
LOW OVER LOUISIANA IN PREVIOUS DAYS. THE HIGHEST POPS AND BEST
CHANCES FOR RAIN ARE IN THE EXTREME EASTERN AREAS OF THE COASTAL
PLAINS...WITH CHANCES AND QPF DECREASING TO THE WEST. TEMPERATURES
WILL BE 3-5F COOLER THAN THE PREVIOUS FORECAST...DUE TO THE
EXTENSIVE CLOUDCOVER...WHICH WILL LAST THROUGH EARLY AFTERNOON
BEFORE SCATTERING OUT DUE TO MIXING AND INGESTING OF BOUNDARY
LAYER MOIST AIR IN TO DEVELOPING THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 647 AM CDT THU JUL 24 2014/
AVIATION...
/12Z TAFS/
TODAY`S FIRST ROUND OF SHOWERS ARE AFFECTING THE AUSTIN AREA
TERMINALS WITH VFR CONDITIONS PREVAILING AT ALL SITES. A SECOND ROUND
OF SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATER IN THE
AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTH CENTRAL
TEXAS. OPTED TO LEAVE OUT MENTIONING SHRA/TSRA FROM THE 12Z TAFS
PACKAGE AS ANTICIPATED SHOWERS OR STORMS WILL BE ISOLATED AND
DIFFICULT TO PINPOINT AT THIS TIME. WINDS WILL BE LIGHT AND
VARIABLE THROUGH ABOUT NOON TODAY AND BECOMING SOUTHEASTERLY AT 5
TO 10 KNOTS IN THE AFTERNOON. OTHERWISE...VFR CONDITIONS TO
DOMINATE THE AREA SITES FOR THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 352 AM CDT THU JUL 24 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
NORTHEASTERLY FLOW ALOFT IS WELL ENTRENCHED ACROSS SOUTH CENTRAL
TEXAS PER AREA 24/00Z RAOB DATA. THIS PATTERN USUALLY DOES NOT
BODE WELL FOR PRECIPITATION. HOWEVER...THE LATEST RADAR DATA DOES
SHOW SOME WEAK ECHOES DEVELOPING ACROSS PORTIONS OF CENTRAL TEXAS.
THIS ACTIVITY IS LIKELY ENHANCED BY A MID-LEVEL SHORTWAVE TROUGH
MOVING THROUGH THE CENTRAL PORTION OF THE STATE EARLY THIS
MORNING. IN ADDITION...A SURFACE TROUGH LOCATED ROUGHLY ALONG AN
AUSTIN TO ROCKSPRINGS LINE AS OF 06Z COULD AID IN THE DEVELOPMENT
OF CONVECTION TODAY. THE HI-RES RUC...3KM TEXAS TECH WRF AND SREF
ARE IN GOOD AGREEMENT IN SHOWING ADDITIONAL CONVECTION THIS
AFTERNOON ACROSS A GOOD PORTION OF SOUTH CENTRAL TEXAS. BASED ON
THE ABOVE...WE HAVE INCLUDED A 20% CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST AREAS TODAY. A DECREASE IN ACTIVITY IS
EXPECTED WITH THE LOSS OF DAYTIME HEATING AND WITH SUBSIDENCE
MOVING IN BEHIND THE MID-LEVEL SHORTWAVE TROUGH. ON FRIDAY... A
FEW SHOWERS AND STORMS REMAIN POSSIBLE ACROSS THE COASTAL
PLAINS... WITH THE REMAINDER OF THE REGION EXPECTED TO REMAIN DRY.
OTHERWISE...HOT AND HUMID CONDITIONS WILL PERSIST THROUGH FRIDAY
WITH HIGHS IN THE MID 90S TO NEAR 100 AND LOWS IN THE 70S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE FLOW ALOFT SLOWLY BEGINS TO CHANGE FROM NORTHEAST TO EAST THIS
WEEKEND AS THE DOMINANT SUBTROPICAL RIDGE AXIS EXPANDS ACROSS THE
REGION. WITH THIS PATTERN INTACT...WE EXPECT DRY WEATHER ALONG WITH
CONTINUED HOT AND HUMID CONDITIONS THROUGH THE WEEKEND. FOR THE
EARLY AND MIDDLE PORTION OF THE UPCOMING WORK WEEK...THE MEDIUM
RANGE MODELS CONTINUE TO REMAIN CONSISTENT WITH THE LARGE SCALE
FLOW PATTERN ACROSS THE CONUS. THE SUBTROPICAL RIDGE WILL
RETROGRADE INTO THE DESERT SOUTHWEST...WHILE A DEEP TROUGH
DEVELOPS OVER THE EASTERN HALF OF THE LOWER 48. THIS WILL BRING
NORTHWEST FLOW ALOFT TO SOUTH CENTRAL TEXAS BEGINNING TUESDAY AND
CONTINUING THROUGH NEXT WEEK. A COLD FRONT IS EXPECTED TO
GRADUALLY WORK SOUTHWARD INTO TEXAS NEXT WEEK...WITH THE TIMING OF
THIS FRONT LIKELY CONTROLLED BY THE AMOUNT OF CONVECTION THAT
DEVELOPS NEAR THE BOUNDARY. MOS GUIDANCE POPS ARE RATHER LOW...BUT
GIVEN THE PATTERN...WOULD NOT BE SURPRISED IF LATER DATA BEGAN TO
SHOW AN INCREASE IN PRECIPITATION CHANCES. FOR NOW...WE WILL KEEP
POPS LOW (20%) FOR TUESDAY AND WEDNESDAY...WITH LOCATIONS
GENERALLY NORTH OF I-10 REMAINING FAVORED FOR PRECIPITATION.
TEMPERATURES SHOULD ALSO BEGIN A SLOW DOWNWARD TREND NEXT
WEEK...BUT CURRENT DATA SUGGESTS THAT WILL NOT HAPPEN UNTIL
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 100 76 99 77 / 20 - - - -
AUSTIN BERGSTROM INTL AIRPORT 73 99 73 98 74 / 20 - - - -
NEW BRAUNFELS MUNI AIRPORT 73 99 73 99 75 / 20 - - - -
BURNET MUNI AIRPORT 74 97 74 97 74 / 30 - - 0 0
DEL RIO INTL AIRPORT 77 100 77 101 79 / 20 - - 0 -
GEORGETOWN MUNI AIRPORT 75 98 75 98 76 / 20 - - 0 0
HONDO MUNI AIRPORT 73 98 74 99 75 / 20 - - 0 -
SAN MARCOS MUNI AIRPORT 73 98 74 98 75 / 20 - - - -
LA GRANGE - FAYETTE REGIONAL 75 98 76 97 77 / 20 20 10 10 -
SAN ANTONIO INTL AIRPORT 76 98 76 98 77 / 20 - - - -
STINSON MUNI AIRPORT 75 98 75 99 76 / 20 10 - - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...26
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1244 PM CDT THU JUL 24 2014
.UPDATE...18Z AVIATION BELOW.
&&
.AVIATION...A MID LEVEL DISTURBANCE IS CONTRIBUTING TO CHANCES FOR
SHRA AND TSTMS TODAY ACROSS SOUTH-CENTRAL TEXAS. COVERAGE HAS
DIMINISHED OVER THE PAST 2 HOURS ALONG AND EAST OF THE I-35
CORRIDOR...WITH NOW JUST A LONE TSTM NORTH OF AUS MOVING SW INTO
THE HILL COUNTRY. LATEST HI RESOLUTION RUNS OF HRRR AND TTECH SEEM
TO HAVE SLIGHTLY BETTER HANDLE ON TRENDS...ALTHOUGH NOT PERFECT...
AND SHOW ISOLD CONVECTION DEVELOPING MID AFTERNOON THROUGH SUNSET
ALONG AND SOUTH OF I-10...WITH BEST CHANCES TO MENTION VCSH IN
TAF AT DRT. SHRA/TSTMS SHOULD END AFTER SUNSET. OUTSIDE OF
PRECIP...VFR CONDITIONS WILL PREVAIL ACROSS THE REGION THIS
AFTERNOON AND EVENING.
&&
.PREV DISCUSSION... /ISSUED 919 AM CDT THU JUL 24 2014/
UPDATE...
JUST SENT A MAJOR UPDATE TO THE FORECAST FOR THE REMAINDER OF THE
DAY THROUGH 02Z THIS EVENING. IN SHORT...THE MCS THAT DEVELOPED
OVER OKLAHOMA/ARKANSAS YESTERDAY HELD TOGETHER ENOUGH TO BRING
SHOWERS TO LOCATIONS ALONG AND NORTH OF INTERSTATE 10 THIS
MORNING. A SECOND AREA OF STRONGER STORMS HAS DEVELOPED IN THE
BRENHAM AREA. THIS LATTER AREA OF STORMS MATCHES WELL WITH THE
TTECH AND CSU WRF RUNS...AND TO A LESSER EXTENT WITH THE HRRR.
THUS...WE EXPECT THIS AREA TO GROW IN SIZE AND BEGIN MOVING NEARLY
DUE WEST ALONG WITH THE GENERAL MOTION OF THE REMNANT FROM A TUTT
LOW OVER LOUISIANA IN PREVIOUS DAYS. THE HIGHEST POPS AND BEST
CHANCES FOR RAIN ARE IN THE EXTREME EASTERN AREAS OF THE COASTAL
PLAINS...WITH CHANCES AND QPF DECREASING TO THE WEST. TEMPERATURES
WILL BE 3-5F COOLER THAN THE PREVIOUS FORECAST...DUE TO THE
EXTENSIVE CLOUDCOVER...WHICH WILL LAST THROUGH EARLY AFTERNOON
BEFORE SCATTERING OUT DUE TO MIXING AND INGESTING OF BOUNDARY
LAYER MOIST AIR IN TO DEVELOPING THUNDERSTORMS.
PREV DISCUSSION... /ISSUED 647 AM CDT THU JUL 24 2014/
AVIATION...
/12Z TAFS/
TODAY`S FIRST ROUND OF SHOWERS ARE AFFECTING THE AUSTIN AREA
TERMINALS WITH VFR CONDITIONS PREVAILING AT ALL SITES. A SECOND ROUND
OF SHOWERS AND THUNDERSTORMS ARE ANTICIPATED LATER IN THE
AFTERNOON AS AN UPPER LEVEL DISTURBANCE MOVES ACROSS SOUTH CENTRAL
TEXAS. OPTED TO LEAVE OUT MENTIONING SHRA/TSRA FROM THE 12Z TAFS
PACKAGE AS ANTICIPATED SHOWERS OR STORMS WILL BE ISOLATED AND
DIFFICULT TO PINPOINT AT THIS TIME. WINDS WILL BE LIGHT AND
VARIABLE THROUGH ABOUT NOON TODAY AND BECOMING SOUTHEASTERLY AT 5
TO 10 KNOTS IN THE AFTERNOON. OTHERWISE...VFR CONDITIONS TO
DOMINATE THE AREA SITES FOR THE FORECAST PERIOD.
PREV DISCUSSION... /ISSUED 352 AM CDT THU JUL 24 2014/
SHORT TERM (TODAY THROUGH FRIDAY)...
NORTHEASTERLY FLOW ALOFT IS WELL ENTRENCHED ACROSS SOUTH CENTRAL
TEXAS PER AREA 24/00Z RAOB DATA. THIS PATTERN USUALLY DOES NOT
BODE WELL FOR PRECIPITATION. HOWEVER...THE LATEST RADAR DATA DOES
SHOW SOME WEAK ECHOES DEVELOPING ACROSS PORTIONS OF CENTRAL TEXAS.
THIS ACTIVITY IS LIKELY ENHANCED BY A MID-LEVEL SHORTWAVE TROUGH
MOVING THROUGH THE CENTRAL PORTION OF THE STATE EARLY THIS
MORNING. IN ADDITION...A SURFACE TROUGH LOCATED ROUGHLY ALONG AN
AUSTIN TO ROCKSPRINGS LINE AS OF 06Z COULD AID IN THE DEVELOPMENT
OF CONVECTION TODAY. THE HI-RES RUC...3KM TEXAS TECH WRF AND SREF
ARE IN GOOD AGREEMENT IN SHOWING ADDITIONAL CONVECTION THIS
AFTERNOON ACROSS A GOOD PORTION OF SOUTH CENTRAL TEXAS. BASED ON
THE ABOVE...WE HAVE INCLUDED A 20% CHANCE FOR SHOWERS AND
THUNDERSTORMS ACROSS MOST AREAS TODAY. A DECREASE IN ACTIVITY IS
EXPECTED WITH THE LOSS OF DAYTIME HEATING AND WITH SUBSIDENCE
MOVING IN BEHIND THE MID-LEVEL SHORTWAVE TROUGH. ON FRIDAY... A
FEW SHOWERS AND STORMS REMAIN POSSIBLE ACROSS THE COASTAL
PLAINS... WITH THE REMAINDER OF THE REGION EXPECTED TO REMAIN DRY.
OTHERWISE...HOT AND HUMID CONDITIONS WILL PERSIST THROUGH FRIDAY
WITH HIGHS IN THE MID 90S TO NEAR 100 AND LOWS IN THE 70S.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE FLOW ALOFT SLOWLY BEGINS TO CHANGE FROM NORTHEAST TO EAST THIS
WEEKEND AS THE DOMINANT SUBTROPICAL RIDGE AXIS EXPANDS ACROSS THE
REGION. WITH THIS PATTERN INTACT...WE EXPECT DRY WEATHER ALONG WITH
CONTINUED HOT AND HUMID CONDITIONS THROUGH THE WEEKEND. FOR THE
EARLY AND MIDDLE PORTION OF THE UPCOMING WORK WEEK...THE MEDIUM
RANGE MODELS CONTINUE TO REMAIN CONSISTENT WITH THE LARGE SCALE
FLOW PATTERN ACROSS THE CONUS. THE SUBTROPICAL RIDGE WILL
RETROGRADE INTO THE DESERT SOUTHWEST...WHILE A DEEP TROUGH
DEVELOPS OVER THE EASTERN HALF OF THE LOWER 48. THIS WILL BRING
NORTHWEST FLOW ALOFT TO SOUTH CENTRAL TEXAS BEGINNING TUESDAY AND
CONTINUING THROUGH NEXT WEEK. A COLD FRONT IS EXPECTED TO
GRADUALLY WORK SOUTHWARD INTO TEXAS NEXT WEEK...WITH THE TIMING OF
THIS FRONT LIKELY CONTROLLED BY THE AMOUNT OF CONVECTION THAT
DEVELOPS NEAR THE BOUNDARY. MOS GUIDANCE POPS ARE RATHER LOW...BUT
GIVEN THE PATTERN...WOULD NOT BE SURPRISED IF LATER DATA BEGAN TO
SHOW AN INCREASE IN PRECIPITATION CHANCES. FOR NOW...WE WILL KEEP
POPS LOW (20%) FOR TUESDAY AND WEDNESDAY...WITH LOCATIONS
GENERALLY NORTH OF I-10 REMAINING FAVORED FOR PRECIPITATION.
TEMPERATURES SHOULD ALSO BEGIN A SLOW DOWNWARD TREND NEXT
WEEK...BUT CURRENT DATA SUGGESTS THAT WILL NOT HAPPEN UNTIL
WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 97 76 100 76 99 / 30 30 - - -
AUSTIN BERGSTROM INTL AIRPORT 96 73 99 73 98 / 30 30 - - -
NEW BRAUNFELS MUNI AIRPORT 96 73 99 73 99 / 40 40 - - -
BURNET MUNI AIRPORT 95 74 97 74 97 / 40 30 - - 0
DEL RIO INTL AIRPORT 98 77 100 77 101 / 20 20 - - 0
GEORGETOWN MUNI AIRPORT 95 75 98 75 98 / 30 30 - - 0
HONDO MUNI AIRPORT 95 73 98 74 99 / 30 30 - - 0
SAN MARCOS MUNI AIRPORT 95 73 98 74 98 / 40 40 - - -
LA GRANGE - FAYETTE REGIONAL 95 75 98 76 97 / 70 50 20 10 10
SAN ANTONIO INTL AIRPORT 95 76 98 76 98 / 30 30 - - -
STINSON MUNI AIRPORT 96 75 98 75 99 / 30 30 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...76
SYNOPTIC/GRIDS...26
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
550 PM CDT THU JUL 24 2014
.UPDATE...
ISSUED AT 550 PM CDT THU JUL 24 2014
HAVING SOME SERIOUS CONCERNS WITH THE PRECIPITATION CHANCES THIS
EVENING...AND POSSIBLY OVERNIGHT TOO.
CURRENTLY...WATER VAPOR LOOP AND RADAR IMAGERY SHOWED A COMPLEX
OF SHOWERS AND STORMS DROPPING SOUTH...NOW INTO NORTHWEST AND
NORTH CENTRAL IOWA. THE EASTWARD PROGRESSION OF THE PRECIPITATION
TOWARDS THE FORECAST AREA HAS COME TO A HALT DUE TO THE COMPLEX
MOTION...ALONG WITH PLENTIFUL DRY AIR OVER THE FORECAST AREA.
2030Z TAMDAR SOUNDING FROM MSP SHOWED 10C OR HIGHER DEWPOINT
DEPRESSIONS FROM 770-600MB AND A DEEP INVERTED-V AT 800MB.
SUBSIDENCE IN THE WAKE OF THIS COMPLEX SHOWING UP AS A SIGNIFICANT
AREA OF CLEARING OVER WEST-CENTRAL MN...DRYING IN THE SAME
LOCATION ON WATER VAPOR...AND SURFACE PRESSURE FALLS UP TO 2
MB/HR.
ITS TOUGH FINDING A MODEL WITH A GREAT HANDLE ON THIS CURRENT
COMPLEX. THE 24.21Z RAP...24.19Z HRRR AND 24.18Z GFS SEEM TO BE
THE BEST AND ALL THREE SUGGEST THAT THE EVENING MAY NOW END UP
DRY ACROSS THE FORECAST AREA. THIS SEEMS REASONABLE AS THE
SUBSIDENCE COMES INTO THE FORECAST AREA IN THE WAKE OF THE
COMPLEX. IN FACT...GIVEN THE CLEARING UPSTREAM...ITS POSSIBLE
THAT CLEARING COMES INTO THE AREA. NEXT CONCERN THEN TURNS TO THE
OVERNIGHT CONVECTION POSSIBILITIES. WITH SUBSIDENCE AND COLD POOL
IN PLACE OVER MN AND NORTH CENTRAL IOWA...WHEN THE LOW LEVEL JET
INCREASES TONIGHT...THE CONVECTION MAY END FIRING MORE ALONG THE
WESTERN MN/IOWA BORDER. THE AFOREMENTIONED MODELS ALONG WITH THE
24.12Z ECMWF AND EVEN TO SOME DEGREE THE 24.18Z NAM ALL SHOW THAT
IDEA. IF THE CONVECTION DEVELOPS AN MCV...THEN THE CONVECTION WILL
DROP SOUTHEAST AND STAY MOSTLY WEST OF THE FORECAST AREA. THIS IS
WHAT THE 24.18Z NAM AND 24.12Z HIRES-ARW SUGGESTED. HOWEVER...IF
NO MCV FORMS...A FRONTOGENETICAL BAND OF SHOWERS AND EMBEDDED
STORMS WOULD MOVE WEST TO EAST INTO THE FORECAST AREA AFTER
07Z...PERHAPS REACHING THE MS RIVER BY 12Z.
FOR NOW...HAVE TRENDED PRECIPITATION CHANCES DOWN SOME FOR THE
EVENING AND FURTHER DECREASES ARE POSSIBLE. HAVE NOT ADJUSTED THE
OVERNIGHT YET...BUT COULD SEE A NEED TO DECREASE PRECIPITATION
CHANCES ALONG/EAST OF THE MS RIVER. NEEDLESS TO SAY THE
PRECIPITATION CHANCES FOR TONIGHT IS A FLUID SITUATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC MODELS...AND
HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLEWATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU JUL 24 2014
THE MAIN FOCUS THROUGH TOMORROW AFTERNOON IS ON WHEN THE HIGHEST
CHANCES FOR RAIN SHOWERS AND THUNDERSTORMS WILL BE TONIGHT.
CONDITIONS WILL STAY DRY THROUGH THE AFTERNOON WITH CONVECTION
DEVELOPING THIS EVENING AND BECOMING MORE WIDESPREAD OVERNIGHT ON
INTO TOMORROW MORNING. RAIN SHOWERS AND THUNDERSTORMS LOOK LIKELY
OVER THIS PERIOD...SO HAVE TAKEN VISIBILITIES DOWN A BIT...BUT
DID NOT WANT TO ADD IN ANY TEMPO GROUPS FOR IFR YET SINCE THERE IS
A CHANCE THAT THE MAIN THUNDERSTORMS COULD BE TO THE SOUTHWEST OF
RST/LSE. THIS CONVECTION SHOULD TRACK TO THE EAST LATE FRIDAY
MORNING WITH WINDS PICKING UP OUT OF THE SOUTH IN ITS WAKE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...AJ
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
319 PM CDT THU JUL 24 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
MAIN FORECAST PROBLEM WAS THE STORMS/WEATHER MOVING IN OVERNIGHT
INTO FRIDAY MORNING.
A TALE OF TWO AIR MASSES ACROSS THE REGION THIS MORNING IN THE
OBSERVATIONAL DATA. 24.12Z RAOBS SHOWING STEEP 700-500MB LAPSE RATES
OVER THE WESTERN DAKOTAS /9C PER KM/ AND MID-LEVEL SATURATION
OCCURRING ON THE EASTERN EDGE OF THE DEEPER N-S MOIST PLUME IN
PLACE. PRECIPITABLE WATER /PWAT/ VALUES AT KBIS/KABR BOTH ARE BOTH
OVER 125 PERCENT THIS MORNING. KBIS AND KABR SOUNDINGS BOTH SHOW
SATURATION AROUND 700MB WITH 500-1000J/KG OF ELEVATED CAPE ABOVE
700MB. EAST OF THE MOIST PLUME...STABILITY REIGNS WITH 5-6C/KM
500-700MB LAPSE RATES AND BELOW NORMAL PWAT VALUES /65 PERCENT/ AT
KMPX. THIS GRADIENT AND MOISTURE TRANSPORT CONVERGENCE OVER THE
DAKOTAS/MN BORDER AT 16Z MATCHED WELL WITH THE MORNING STORMS AND
WEATHER IN THE DAKOTAS. THIS ALL ENHANCED BY A VERY VISIBLE
SHORTWAVE TROUGH SEWRD OF KBIS AND ANOTHER NORTH OF THE MT/ND/SRN
CANADA BORDER.
AS THE LARGE SCALE SHIFTS OVER NORTH AMERICA AND THE LONG WAVE
TROUGH OVER THE EAST WEAKENS...FLAT RIDGING BUILDS ACROSS THE
NORTHERN STATES /THROUGH SATURDAY/. THIS WILL PROMOTE WARMING AND
RICHER MOISTURE TO MOVE INTO THE REGION FOR A PERIOD...BEFORE
REAMPLIFICATION OF THE TROUGH OVER THE ERN CONUS OCCURS /SUNDAY/.
BEGINNING OVERNIGHT...THE DAKOTAS AIR MASS WILL ADVECT EASTWARD
AND INTO THE AREA. THIS AIRMASS IS CHARACTERIZED BY HIGHER
MOISTURE BUT ALSO VERY WARM TEMPERATURES ALOFT AS AN ELEVATED
MIXED LAYER MOVES IN. WHILE THIS HAS STEEP MID-LEVEL LAPSE
RATES...THE 700MB TEMPERATURES WARM FROM 8C TO 12-14C
FRIDAY...PROVIDING A STOUT CAPPING INVERSION TO SURFACE BASED
CONVECTION BY AFTERNOON. THIS TRANSLATES TO A 600 J/KG SBCIN. THIS
CAP BUILDING HAS VERY GOOD CONSENSUS AMOUNT THE DETERMINISTIC MODELS...AND
HAVE LOWERED RAIN CHANCES FRIDAY AFTERNOON ACCORDINGLY.
PRIOR TO THE ELEVATED MIXED LAYER BUILDING IN FRIDAY...LOW-LEVEL
WARM ADVECTION AND MOISTURE TRANSPORT INCREASES WITH HEIGHT FALLS
AND INCREASED SOUTHERLY FLOW OVERNIGHT. THIS EVENING THERE IS SOME
SIGNAL FOR MID-LEVEL MOISTURE TRANSPORT CONVERGENCE /700MB/ TO
MOVE IN FROM THE WEST DURING THE EVENING AND LAPSE RATES WOULD SAY
SOME MID-LEVEL TOWERING CU COULD DEVELOP SOME SHOWERS
/100-300J/KG MUCAPE/. HAVE BEEN MONITORING THE CONVECTION ENTERING
WESTERN MN AND WHILE MUCAPE VALUES HAVE INCREASED A FEW HUNDRED
FROM 15-18Z...MUCH OF MN IS STILL QUITE STABLE. HOWEVER...THE
NORTHERN SIDE SEEMS TO BE TIED TO THE 700 MB TRANSPORT CONVERGENCE
AND SHORTWAVE TROUGH APPROACHING FARGO. WOULD EXPECT ECHO TO
WEAKEN AS IT MOVES TOWARD I-35...ALTHOUGH THERE IS WEAK
FORCING...THE AIR MASS IS VERY DRY. WILL HAVE TO MONITOR...BUT
TIMING LOOKS TO FIT THE EVENING INCREASE OF PRECIPITATION CHANCES.
BY MIDNIGHT...AS THE RIDGE BUILDS EAST...MOISTURE TRANSPORT AND A 40-
50KT LOW-LEVEL JET AT 850 MB FEED THE EASTERN EDGE OF THE MOISTURE
PLUME UP THE . BY 09Z...A MESOSCALE CONVECTIVE SYSTEM IS EXPECTED
TO ENTER THE WESTERN FORECAST AREA ON VERY STRONG MOISTURE
TRANSPORT CONVERGENCE AT 850 MB /50KTS DECREASING TO 15 KTS...KDSM
TO KLSE/. THIS SIGNAL IS VERY CONSISTENT AMONG THE 24.12Z MODELS
AND LATEST RAP GUIDANCE. CORFIDI VECTORS SUGGEST SOUTHEAST
MOVEMENT TO THE STRONGER CONVECTIVE ELEMENTS...AND THIS COULD POSE
SOME PROBLEMS WITH THE COMPLEX MISSING TO THE SOUTHWEST. WITH THE
MOISTURE TRANSPORT CONVERGENCE INTO THE HEART OF THE FORECAST
AREA...WOULD THINK A MISS IS PROBABLY UNLIKELY. THIS WOULD FAVOR
THE AREAS SOUTHWEST OF I-94...ESPECIALLY INTO NORTHEAST IOWA AND
LITTLE CHANGE TO THE RAIN CHANCES WERE MADE.
PRECIPITABLE WATER VALUES INCREASE RAPIDLY OVERNIGHT WITH OVER
1.75 INCHES IN THE AREA BY MORNING AND WARM CLOUD DEPTHS OF 4 KM.
THUS HEAVY RAINFALL RATES WILL OCCUR IN THE SYSTEM...BUT MANY
AREAS CAN USE THE RAINS. SOME BRIEF CITY FLOODING IS POSSIBLE.
ISOLATED HAIL AND GUSTY WINDS HAVE BEEN ADDED TO AREAS WEST OF THE
MISS RIVER IN THE HAZ WEATHER OUTLOOK DUE TO THE MAGNITUDE OF
CONVERGENCE/FORCING AND ABOUT 1500 J/KG OF MUCAPE. SPC HAS ALSO
SHIFTED THEIR DAY 1 CONVECTIVE OUTLOOK TO NEAR OUR WESTERN
FORECAST AREA EDGE...WHICH IS APPROPRIATE. CAPPING SHOULD THEN
BUILD IN AND THE SYSTEM MOVES EAST/SOUTHEAST IN THE AFTERNOON.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 320 PM CDT THU JUL 24 2014
FRIDAY NIGHT POSES AN INTERESTING PROBLEM IN SRN WISCONSIN AS THE
CAP IS STILL FULLY IN PLACE WITH NO SURFACE BASED CONVECTION
ALLOWED PER ALL GUIDANCE /600 SBCIN AND 700MB TEMPS NEAR 14C/.
YET A HANDFUL OF DETERMINISTIC MODELS CONTINUE A SIGNAL OF QPF
ACROSS SRN WISCONSIN IN THE EVENING. HAVE KEPT A SMALL RAIN CHANCE
THERE AS IT WOULD BE SOME MID-LEVEL INSTABILITY THAT WOULD HAVE TO
BE TAPPED NORTH OF THE SURFACE LOW SHIFTING THROUGH ERN IA. THE
24.12Z NAM DOES HAVE SOME 900-800MB FRONOTGENESIS WORKING WITHIN
THE CAPPED AREA...AND POSSIBLY SOME ISENTROPIC LIFT GENERATES
STABLE SHOWERS. PREFER THE 24.12Z NAM WITH RAINFALL SOUTH OF THE
FORECAST AREA...BUT HAVE KEPT A SLIGHT CHANCE OF RAIN TO COVER
THIS SITUATION FRIDAY EVENING.
A DRYING TREND THEN IN NORTHWEST FLOW AFTER MIDNIGHT...THROUGH
SATURDAY PROVIDES A VERY NICE DRY DAY. THE HIGH PRECIPITABLEWATER
AIRMASS SHOULD PUSH SOUTH TO NEAR I-80 CORRIDOR.
STRONG QG CONVERGENCE FORCING MOVES IN SUNDAY WITH THE STRONG
TROUGH MOVING THROUGH MN/WI AS THE LONG WAVE AMPLIFIES AGAIN OVER
THE EASTERN CONUS. FORCING COMES IN LATER SATURDAY NIGHT AND IS
STRONGEST SUNDAY WITH SOME INSTABILITY. HAVE INCREASED RAIN
CHANCES FOR SUNDAY. RAIN CHANCES MAY NEED TO BE PULLED FURTHER
SOUTHWEST AS WELL DEPENDING ON THE WAVE TRACK. A CLOUDY BREEZY
SHOWERY DAY FOR MOST AREAS IT SEEMS.
MONDAY THROUGH THURSDAY HAVE BELOW NORMAL TEMPERATURES AND MOSTLY
DRY WEATHER UNDER THE INFLUENCE OF THE LONGWAVE TROUGH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1239 PM CDT THU JUL 24 2014
THE MAIN FOCUS THROUGH TOMORROW AFTERNOON IS ON WHEN THE HIGHEST
CHANCES FOR RAIN SHOWERS AND THUNDERSTORMS WILL BE TONIGHT.
CONDITIONS WILL STAY DRY THROUGH THE AFTERNOON WITH CONVECTION
DEVELOPING THIS EVENING AND BECOMING MORE WIDESPREAD OVERNIGHT ON
INTO TOMORROW MORNING. RAIN SHOWERS AND THUNDERSTORMS LOOK LIKELY
OVER THIS PERIOD...SO HAVE TAKEN VISIBILITIES DOWN A BIT...BUT
DID NOT WANT TO ADD IN ANY TEMPO GROUPS FOR IFR YET SINCE THERE IS
A CHANCE THAT THE MAIN THUNDERSTORMS COULD BE TO THE SOUTHWEST OF
RST/LSE. THIS CONVECTION SHOULD TRACK TO THE EAST LATE FRIDAY
MORNING WITH WINDS PICKING UP OUT OF THE SOUTH IN ITS WAKE.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...HALBACH