Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/29/14
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
1019 PM PDT Wed Mar 26 2014
.Synopsis...
Significant mountain snow and gusty winds are likely tonight. Wet
and cooler weather will continue through the weekend.
&&
.Discussion...
Active afternoon and evening with confirmed tornadoes over Glenn
county(Artios) and just west of Roseville. Activity has really
diminished over the past hour with the loss of daytime heating and
transitioned over the mountains. Snow continues above 5000 feet
with several inches of overnight accumulation likely. Valley
locations will have a lull in the showers overnight before
activity picks up tomorrow morning with disturbance dropping
southeast over the area.
.Previous Discussion... Next wave of precip is spreading into the
Sierra as the next batch of short-wave energy rotates inland.
Forecast soundings indicate showers and potential for some
thunderstorms today in the valley. Buoyancy or CAPE is only around
100 J/kg at most from the NAM and RUC. But the HRRR was showing
between 100-200 J/kg. The CAPE layer is relatively shallow. But,
that is normal for here. The interesting thing to note is the
shear values. The 0-1 km shear is anywhere from 12 to 20 m/s while
the 0-6 km shear is from 35 to 55 m/s, with the strongest areas
between Sacramento and Red Bluff. The significance of these shear
profiles are that they are very favorable for rotating updrafts if
individual cells are able to develop. Similar to yesterday, it
will be a waiting game today to see if enough clearing develops
behind the main area of showers that will move across the area
during the morning.
The back of edge of the wave/clouds are near the coast.
Orographic flow may keep clouds are coastal range, but shadowed
areas in the valley may see enough clearing later. We already see
evidence of some thinning clouds in the western valley.
We are not making any major changes to the snow amounts and the
Winter Storm Warning. The next wet system is forecast to drop
southward through the region Saturday. JClapp
&&
.Extended Discussion (Sunday through Wednesday)
Pacific moisture tap and associated surface precip band will shift
southward across the forecast area late Saturday into early
Sunday. Models are in decent agreement with the timing, so
confidence is high in widespread rain/snow Saturday night. This
will be another winter-like system with snow levels as low as
4000ft, so passes will see accumulating snow once again. Heavier
rains are expected compared to the current mid-week system, with a
half inch to an inch of rain possible in the Valley and a foot or
more in the mountains.
Models show weak ridging over the state on Sunday but WAA and
weak lift could promote some continued light overrunning
precipitation mainly north of the Sacramento area. Daytime highs
will range from a little below normal to the north where cloud
cover will be more extensive to a little above normal to the
south.
The next in a series of Pacific storm systems is forecast to move
into NorCal by Monday afternoon, bringing another good chance of
precipitation to the entire CWA. Relatively low snow levels are
expected with this system (which has the potential to be even
colder than the last). The upper low is forecast to push inland on
Tuesday bringing a turn to showery conditions with continued
cooler than normal daytime temperatures. -DVC
&&
.Aviation...
VFR/MVFR conditions in the valley with Isold to Sct showers.
IFR/LIFR ceilings and visibilities with snow down to 4000 feet in
the Sierra.
&&
.STO Watches/Warnings/Advisories...
winter storm warning until 11 am pdt thursday above 5000 feet in
the west slope northern sierra nevada...western plumas
county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1031 AM MDT THU MAR 27 2014
.UPDATE...
&&
.SHORT TERM...SHOWERS ACROSS THE NORTHEAST COLORADO PLAINS HAVE
SHIFTED EAST OF THE AREA AS UPPER TROUGH MOVED INTO KANSAS. THERE
MAY STILL BE A FEW LINGERING RAIN AND/OR SNOW SHOWERS OVER THE FAR
EASTERN PLAINS. OTHERWISE...MOUNTAIN OROGRAPHICS CONTINUE AS WEAK
SUBSIDENCE AND A BIT OF DRYING SPREADS INTO THE AREA. STILL SOME
LIGHT SNOW ONGOING ACROSS THE HIGH COUNTRY...BEGINNING TO SHOW
SOME DECREASE. WINDS A BIT GUSTY ACROSS THE HIGHER RIDGES AND
ALONG PORTIONS OF THE FOOTHILLS. NEXT DISTURBANCE CURRENTLY OVER
NORTHERN UTAH WILL BE MOVING ACROSS COLORADO DURING THE AFTERNOON
AND EVENING. THERE MAY BE A SLIGHT DECREASE IN THE MOUNTAIN SNOW
EARLY THIS AFTERNOON BEFORE INCREASING AGAIN WITH INCREASING MID
LEVEL ASCENT AND CONTINUED OROGRAPHICS. IN ADDITION...LAPSE RATES
EXPECTED TO BE AROUND 8 C/KM. THERE IS CURRENTLY SOME LIGHTNING IN
NORTHERN UTAH...SO THIS NEXT DISTURBANCE IS A BIT UNSTABLE. AT
THIS TIME...WILL HOLD OFF ON ANY WINTER WEATHER HILITES AS THE
BEST LIFT AND INSTABILITY LOOKS TO MOVE QUICKLY ACROSS THE AREA.
ADDITIONAL MOUNTAIN ACCUMULATIONS STILL LOOK TO BE IN TO 2 TO 4
INCH RANGE...PERHAPS A BIT MORE WITH HEAVIER SHOWERS. ACROSS
PLAINS...DESPITE WINDS SHIFTING TO THE NORTHWEST THIS AFTERNOON
THERE APPEARS TO BE SUFFICIENT LIFT AND INSTABILITY TO WARRANT A
SLIGHT CHANCE OF SHOWERS LATE IN THE DAY ALONG THE URBAN CORRIDOR.
LATEST RAP INDICATING THIS POTENTIAL WITH SOME LIGHT QPF JUST EAST
OF DENVER. FOR NOW WILL KEEP THINGS DRY. SLIGHT CHANCE OF SHOWERS
THIS EVENING WHEN THE DISTURBANCE MOVES OVERHEAD. THERE MAY BE A
BRIEF MIX OF RAIN AND SNOW MOST LOCATIONS. WON`T CHANGE THE
EVENING GRIDS AT THIS TIME.
.AVIATION...SHOWERS HAVE MOVED EAST OF THE AREA WITH CEILINGS
IMPROVING TO VFR. WINDS SLOW TO SHIFT TO THE NORTHWEST. LATEST RAP
AND HRRR INDICATING NORTHWEST WINDS BY 18Z. HAVE DELAYED THE
NORTHWEST WINDS. SOME SHOWERS POSSIBLE THIS AFTERNOON AS NEXT
DISTURBANCE APPROACHES. APPEARS THESE SHOWERS SHOULD REMAIN EAST
OF THE AREA DUE TO DOWNSLOPE WINDS PREVAILING. SLIGHT CHANCE OF
SHOWERS THIS EVENING...COULD BE BRIEFLY MIXED WITH SNOW. WILL
MAINTAIN THE VCSH FOR NOW AND INCLUDE A TEMPO CEILING OF 6000 FEET
AGL FROM 00Z TO 03Z. LATEST MODELS INDICATING WINDS BECOMING MORE
NORTHEAST AFTER 03Z THIS EVENING WITH DRAINAGE DEVELOPING BY
MIDNIGHT WITH CLEARING SKIES. WILL TREND THE WINDS MORE NORTHERLY
THIS EVENING.
&&
.PREV DISCUSSION... /ISSUED 501 AM MDT THU MAR 27 2014/
SHORT TERM...UPPER TROUGH AXIS NOW SWINGING ACROSS THE NORTHERN AND
CENTRAL MOUNTAINS AT THIS HOUR AS EVIDENT ON SATELLITE IMAGERY AND
RAP UPPER AIR WIND FIELDS. HAVE NOTICED AN INCREASE IN SNOWFALL
INTENSITY UP ALONG THE CONTINENTAL DIVIDE ESPLY UP AROUND THE
EISENHOWER TUNNEL IN THE PAST HOUR. CDOT CAMS REVEAL PRETTY WINTRY
DRIVING CONDITIONS UP AT THE TUNNEL WITH VSBYS NEAR ZERO AT TIMES IN
SNOW AND BLOWING SNOW. OTHERWISE THE HIGH MOUNTAIN PARKS AS WELL AS
EAST FACING MTN SLOPES HAVE ESCAPED MUCH OF THIS PRECIPITATION
OVERNIGHT. AS THE UPPER TROUGH CONTINUES TO PASS BY...A COLD FRONT
CONTINUES TO SLIP SOUTH ACROSS SOUTHERN PORTIONS OF THE FORECAST
AREA...INCLUDING THROUGH THE DENVER METRO AREA. IN THE WAKE OF THIS
FRONTAL BNDRY...THE AREA OF LIGHT RAIN SHOWERS THAT FORMED ACROSS
LARIMER AND WELD COUNTIES HAS MOVED SOUTHWARD AND WAS NOW SKIRTING
EASTERN PORTIONS OF THE DENVER METRO AREA. QG VERTICAL VELOCITY
FIELDS INDICATE WEAK ASCENT IN THE VICINITY OF THESE SHOWERS AND
ONLY THROUGH 12Z. AFTER THAT TIME VERTICAL VELOCITIES FLIP WITH WEAK
TO MODERATE DOWNWARD MOTION SPREADING OVER MOST OF NORTHEAST
COLORADO BY MID TO LATE MORNING. IN THE HIGH COUNTRY...SYNOPTIC
SCALE LIFT HAS PLAYED ONLY A SMALL ROLE IN SNOW PRODUCTION
OVERNIGHT. OROGRAPHIC FORCING WAS PROBABLY THE MAIN PLAYER WHICH
WOULD EXPLAIN THE BULK OF THE OVERNIGHT SNOWFALL ON WEST FACING
SLOPES. WINTER WEATHER ADVISORY FOR THE HIGH COUNTRY WILL BE
ALLOWED TO EXPIRE AT 12Z THIS MORNING.
FOR THE REST OF TODAY...SHOULD SEE A RESSURGENCE IN SNOWFALL IN THE
HIGH COUNTRY EARLY THIS MORNING WITH THE ARRIVAL OF ANOTHER BATCH OF
PACIFIC MOISTURE AND THE ONSET OF COLD AIR ADVECTION. ITS POSSIBLE
THAT UPPER WEST FACING SLOPES COULD SEE ANOTHER FEW INCHES OF SNOW
BEFORE SNOWFALL WINDS DOWN DURING THE LATE MORNING AND EARLY
AFTERNOON HOURS. THE HIGH VALLEYS MAY ALSO SEE AN UPTICK IN SHOWER
ACTIVITY IN THE NEXT FEW HOURS. ON THE PLAINS...TREND WILL BE
TOWARDS DRYING AS BNDRY LAYER WINDS TURN NORTHWESTERLY WHICH IS A
DRYING WIND IN THESE PARTS...AND WITH THE ARRIVAL OF SUBSIDENCE
ALOFT. DRYING WILL START ALONG THE FRONT RANGE AND SPREAD EAST
THROUGH THE DAY. PRECIPITATION ON THE PLAINS EARLY THIS MORNING IS
PRINCIPALLY RAIN WITH SFC TEMPERATURES IN THE UPPER 30S/LOWER 40S
AND DEWPOINT IN THE MID-TO-UPPER 30S. ARRIVAL OF COOLER AIR AROUND
DAY BREAK COULD CHANGE SOME OF THIS RAIN OVER TO A RAIN/SNOW
MIX...BUT DO NOT EXPECT TO SEE ANY SNOW ACCUMULATION IN AREAS BELOW
5500 FEET. WITH THE POST-FRONTAL AIRMASS ON THE PLAINS...SHOULD SEE
COOLER TEMPERATURES TODAY...SOME 10-15 DEG F LOWER THAN THOSE
OBSERVED YESTERDAY. MOS GUIDANCE INDICATES HIGHS IN THE LOWER TO MID
50S AT LOWER ELEVATIONS. HOWEVER THE GFS MODEL GUIDANCE IS CURIOUSLY
INDICATING HIGHS IN THE LOW TO MID 60S...EVEN THOUGH GFS SOUNDINGS
SUPPORT READINGS IN THE 50S. WILL STICK WITH THE COOLER GUIDANCE.
TONIGHT...AN ELONGATED AREA OF WEAK QG ASCENT AND INSTABILITY
ASSOCIATED WITH ANOTHER SHORTWAVE TROUGH CAUGHT UP IN MODERATE ZONAL
FLOW ALOFT IS FORECAST TO PASS OVER THE FORECAST AREA LATE THIS
AFTERNOON AND EVENING. AS IT PASSES SHOULD SEE A RESSURGENCE IN
SNOWFALL IN THE HIGH COUNTRY...BUT NOT TO THE LEVEL OF SNOW
INTENSITY IN THE HIGH COUNTRY AT THE PRESENT TIME. WILL HANG ONTO
LIKELY POPS IN THE HIGH COUNTRY WITH ANOTHER 1-4 INCHES BY LATE
TONIGHT AND MAINLY ON WEST FACING EXPOSURES. DO NOT SEE THE NEED FOR
AN ADVISORY AT THIS TIME AS TEMPERATURES WILL BE RELATIVELY MILD
EVEN AT HIGHER ELEVATIONS. EAST OF THE MTNS...COULD SEE A FEW
EVENING SHOWERS OF LITTLE CONSEQUENCE. OTHERWISE DRYING AND CLEARING
AFTER MIDNIGHT.
LONG TERM...A DRIER NORTHWEST FLOW ALOFT WILL MOVE OVER COLORADO
ON FRIDAY AS MORE SUBSIDENT AIRMASS FILTERS IN. SNOW SHOWERS WILL
DIMINISH BY FRIDAY AFTERNOON AS MOISTURE BECOMES MORE SHALLOW IN
THE MOUNTAINS. DRY CONDITIONS WILL RETURN STATEWIDE ON FRIDAY
NIGHT. BROAD UPPER LEVEL HIGH PRESSURE WILL BE OVER COLORADO ON
SATURDAY AS FLOW ALOFT SHIFTS MORE WESTERLY. DRY AND WARMER ON
SATURDAY BUT INCREASING GUSTY WINDS IN THE MOUNTAINS. CROSS
SECTIONS INDICATE GUSTS UP AROUND 40 MPH OVER THE HIGH MOUNTAIN
PASSES. WINDS INCREASE EVEN FURTHER ON SUNDAY AS A WEAK WAVE MOVES
THROUGH THE FLOW SUNDAY AFTERNOON AND NIGHT. COULD SEE SOME GUSTS
OVER 50 MPH OVER MOUNTAINS AND EAST SLOPES. THERE IS SOME
MOISTURE WITH THIS DISTURBANCE FOR SCATTERED SHOWERS IN THE
MOUNTAINS BUT DOESN`T LOOK ALL THAT DEEP FOR ANY HIGHER COVERAGE.
AS THE TROF MOVES ACROSS THE PLAINS SUNDAY NIGHT...COULD BE A FEW
SHOWERS ESPECIALLY OVER THE NORTHERN BORDER AREAS OF WYOMING AND
NEBRASKA.
ANOTHER STRONGER TROF BEGINS TO DEVELOP OVER THE GREAT BASIN ON
LATE MONDAY AND TUESDAY HOWEVER LONG RANGE MODELS ARE NOT IN
AGREEMENT ON THE PROGRESSION ACROSS COLORADO. THIS WILL LEAD TO A
CHANCE OF SHOWERS CONTINUING IN THE MOUNTAINS WITH A SLIGHT CHANCE
OF SHOWERS OVER THE PLAINS.
AVIATION...MVFR CEILINGS AT DENVER AREA TERMINALS THROUGH 14Z
THIS MORNING. LOW CIGS WILL BE ACCOMPANIED BY LIGHT RAINFALL AT
TIMES. RAIN COULD BRIEFLY CHANGE OVER TO A MIX OF RAIN AND SNOW
BEFORE 14Z WITH NO ACCUMULATION EXPECTED. BY MID TO LATE MORNING
SHOULD SEE VFR CONDITIONS WITH PARTIAL CLEARING. LATE THIS
AFTERNOON OR EARLY THIS EVENING COULD SEE A FEW LIGHT RAIN
SHOWERS DRIFT ACROSS THE METRO AREA WITH MOST EXITING THE AREA BY
MID- EVENING. ANTICIPATE GUSTY AND ERRATIC WINDS AROUND SHOWERS
THIS MORNING. OTHERWISE NORTH-NORTHWEST WINDS OF 10-15KTS THIS
MORNING SHOULD BECOME WESTERLY BY THIS AFTERNOON...THEN BACK TO
NORTHWEST THIS EVENING.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....ENTREKIN
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
905 PM EDT FRI MAR 28 2014
.DISCUSSION...CONVECTIVE COMPLEX HAS WEAKENED OVER THE NORTHEAST
GULF OF MEXICO WITH LARGER RAIN SHIELD MAINLY IMPACTING NORTH
FLORIDA THIS EVENING. FOCUS FOR PRECIPITATION WILL NOW BE WITH
LINE OF SHOWERS AND ISOLATED STORMS APPROACHING THE WEST FLORIDA
COAST. LATEST WRF AND HRRR MODEL GUIDANCE HAVE THIS ACTIVITY NOT
REACHING THE AREA UNTIL AFTER MIDNIGHT...INITIALLY MOVING THROUGH
AREAS NORTH OF ORLANDO AND THE CAPE AND THEN SPREADING SOUTHWARD
THROUGH LATE TONIGHT. WILL KEEP RAIN CHANCES RANGING FROM 40-50
PERCENT ACROSS OKEECHOBEE COUNTY AND THE SOUTHERN TREASURE COAST
WITH 60-70 POPS NORTH. HOWEVER HAVE UPDATED WEATHER GRIDS FOR THE
EXPECTED LATER TIMING. THERE WILL REMAIN AN ISOLATED THREAT FOR
STORMS TO PRODUCE STRONG WIND GUSTS WITH THIS BAND...MAINLY FROM
ORLANDO AREA NORTHWARD BUT ACTIVITY LOOKS TO WEAKEN AS THE NIGHT
PROGRESSES AND DYNAMIC SUPPORT DIMINISHES. CLOUDY SKIES AND LOW
LEVEL SOUTHERLY FLOW WILL KEEP TEMPS MILD OVERNIGHT WITH LOWS IN
THE MID-UPPER 60S...EXCEPT AROUND 70 DEGREES ALONG PORTIONS OF THE
COAST SOUTH OF THE CAPE.
&&
.AVIATION...VFR CONDS MAINLY EXPECTED. IT LOOKS LIKE MAJORITY OF
PRECIPITATION WILL HOLD OFF UNTIL MIDNIGHT AS LINE OF SHOWERS AND
ISOLATED STORMS OVER THE EASTERN GULF EVENTUALLY MOVE INTO THE
REGION. HAVE MAINTAINED TEMPO GROUPS FOR SHOWERS AND MVFR CONDS IN
THE TAFS AS TIMING STILL SEEMS REASONABLE. THIS ACTIVITY SHOULD
WEAKEN LATE TONIGHT INTO EARLY MORNING SATURDAY AND THEN SHOULD
SEE ANOTHER WAVE OF SHOWERS/STORMS INTO SATURDAY AHEAD OF
APPROACHING FRONT.
&&
.MARINE...BOTH SWAN AND WNAWAVE GUIDANCE UNDER DOING SEAS
CURRENTLY WITH LATEST WAVE HEIGHTS AT BUOY 41009 STILL UP TO
AROUND 7 FEET. HOWEVER THESE SEAS ARE STILL EXPECTED TO GRADUALLY
SUBSIDE INTO LATE EVENING AND OVERNIGHT SO WILL MAINTAIN SMALL
CRAFT EXERCISE CAUTION HEADLINES OVER THE WATERS. SOUTH TO
SOUTHEAST WINDS AROUND 10 TO 15 KNOTS WILL INCREASE UP TO 15 TO 20
KNOTS OFFSHORE LATER TONIGHT. A FEW STORMS MAY STILL PUSH
OFFSHORE...MAINLY NORTH OF SEBASTIAN INLET LATER TONIGHT AS LINE
OF CONVECTION MOVES INTO THE REGION.
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
WEITLICH/WIMMER
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
208 PM EDT THU MAR 27 2014
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT THU MAR 27 2014
A COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA DURING THE EARLY
MORNING HOURS ON FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE
OHIO VALLEY AROUND FRIDAY NIGHT INTO SATURDAY. ANOTHER FRONTAL
SYSTEM MAY AFFECT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1003 AM EDT THU MAR 27 2014
WITH THE MORNING UPDATE HAVE TRIED TO TREND HOURLY POPS TO BETTER
MATCH OUTPUT OF HRRR AND RAP AS WELL AS LATEST RADAR TRENDS. THIS
DROPPED POPS TO LOW CHANCE CATEGORY FOR THE SOUTHERN COUNTIES
WITHIN THE NEXT COUPLE OF HOURS BUT KEPT CATEGORICAL GOING ACROSS
THE NORTH UNTIL 18Z OR SO BEFORE DROPPING BACK TO CHANCE
EVERYWHERE BY AROUND 21Z. KEPT CHANCE OF THUNDER FOR THE
AFTERNOON BASED ON LOW LEVEL JET FORCING AND SOME ELEVATED
INSTABILITY ADVECTING IN. ALSO ADDED A SLIGHT CHANCE FOR VERY
LIGHT SNOW FOR THE NEXT COUPLE OF HOURS ACROSS THE NORTHEAST BASED
ON OBSERVATIONS AND DUAL POL DATA...BUT SHOULD BE NOTED THAT ANY
WINTRY MIX WILL BE VERY BRIEF AND NO ACCUMULATION OF ANY KIND IS
EXPECTED.
PREVIOUS DISCUSSION FOLLOWS...
OTHERWISE...PRECIPITATION POTENTIAL SHOULD TAIL OFF THIS AFTERNOON
AS THE UPPER DISTURBANCE LIFTS OFF TO THE NORTHEAST. STEEP MID LEVEL
LAPSE RATES BLEED INTO THE AREA LATER THIS AFTERNOON...ALTHOUGH
THERE DOESN/T SEEM TO BE MUCH OF A FOCUS FOR PRECIPITATION LATER
THIS AFTERNOON. WILL KEEP CHANCE POPS FOR SHOWERS/THUNDERSTORMS
GOING THIS AFTERNOON.
STRONG LOW LEVEL JET AROUND 65 KTS EXPECTED TO MOVE INTO THE AREA
LATER TODAY. DON/T THINK THERE IS MUCH OF A THREAT FOR THESE WINDS
TO MIX DOWN TO THE SURFACE DUE TO THE CLOUD COVER AND POOR LOW
LEVEL LAPSE RATES...BUT DO THINK POTENTIAL EXISTS FOR SOME WIND
GUSTS AROUND 35 MPH THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 313 AM EDT THU MAR 27 2014
COLD FRONT IS EXPECTED TO MOVE INTO THE AREA BY THE EARLY MORNING
HOURS ON FRIDAY. WILL GO WITH HIGH POPS FOR SHOWERS/THUNDERSTORMS
TONIGHT GIVEN THE EXPECTED LIFT ALONG A 65-70 KT LOW LEVEL JET
AHEAD OF FRONT AND STEEP MID LEVEL LAPSE RATES. MAY SEE SOME
HIGHER WINDS MIX DOWN TO THE SURFACE IN THE VICINITY OF ANY
SHOWERS...BUT LOW LEVEL LAPSE RATES REMAIN POOR...SO DON/T THINK
THE WINDS WILL GET TOO OUT OF HAND.
WILL PROBABLY SEE A LULL IN THE PRECIPITATION THREAT ON FRIDAY AS
FRONT STALLS OUT SOUTH OF THE OHIO RIVER. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE THROUGH THE AREA BY SATURDAY...WHICH SHOULD HELP TO
INDUCE A SURFACE ALONG THE STALLED OUT FRONT. WILL BRING POPS
BACK INTO THE AREA FRIDAY NIGHT AND SATURDAY. MOST OF THE
PRECIPITATION WITH THIS SYSTEM EXPECTED TO BE IN THE FORM OF
RAIN...HOWEVER THERE IS A POTENTIAL FOR SOME WET SNOW OVER THE
NORTHERN ZONES SATURDAY MORNING.
UNDER CONTINUED STRONG WARM ADVECTION TONIGHT...EXPECTING
TEMPERATURES TO RISE OR HOLD GENERALLY IN THE LOWER TO MIDDLE 50S
UNTIL FRONTAL PASSAGE EARLY SATURDAY MORNING. BASED ON LOW LEVEL
THICKNESS PROGS...THE GFS MOS LOWS FRIDAY NIGHT LOOK TOO COOL...SO
WILL RAISE THEM ABOUT A CATEGORY IN THAT PERIOD. OTHER PERIODS DON/T
LOOK TOO BAD.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 158 PM EDT THU MAR 27 2014
PROGRESSIVE SPRING PATTERN LOOKS TO CONTINUE THROUGH MUCH OF NEXT
WEEK...BRINGING NEAR NORMAL TEMPERATURES ALONG WITH SEVERAL
CHANCES FOR SPRING RAINS.
ECMWF AND GFS SHOW SURFACE RIDGE IN PLACE ACROSS THE AREA ON
MONDAY. A QUICK MOVING LOW PRESSURE SYSTEM IS EXPECTED TO PUSH
THROUGH THE GREAT LAKES ON MONDAY NIGHT AND TUESDAY...DRAGGING A
COLD FRONT ACROSS INDIANA. AT THE MOMENT DECENT SOUTHERLY FLOW
AHEAD OF THE THAT SYSTEM SHOULD RESULT IN SOME MOISTURE AVAILABLE.
HIGH PRESSURE BUILDS ACROSS THE AREA FOR WEDNESDAY IN THE WAKE OF
THAT QUICK MOVING COLD FRONT. BY THURSDAY AS WARM FRONT APPROACHES
FROM THE SOUTHWEST...GOOD MOISTURE AND LOWER LEVEL CONVERGENCE
BECOMES AVAILABLE. THUS CHANCES FOR SHRA AND ISOLATED TSRA WILL RETURN.
&&
.AVIATION /DISCUSSION FOR 271800Z TAFS/...
ISSUED AT 1234 PM EDT THU MAR 27 2014
VFR CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR DURING THIS TAF
PERIOD.
NAM SUGGESTS STRONG LLJ TO PUSH ACROSS INDIANA THIS EVENING AHEAD
OF AN AREA OF LOW PRESSURE AND COLD FRONT POISED TO PUSH ACROSS
INDIANA OVERNIGHT. GOOD MOISTURE LOOKS TO REMAIN IN PLACE ACROSS
THE AREA TODAY AS FORECAST SOUNDINGS AND TIME HEIGHT SECTIONS SHOW
GOOD SATURATION AMID GOOD LIFT. WITH CCL/S NEAR 2K-2.5K FEET WILL
TREND TOWARD MVFR CEILINGS TONIGHT IN THE WAKE OF THE FRONTAL
PASSAGE.
TIME HEIGHT SECTIONS SHOW SUBSIDENCE ARRIVING ON NW WINDS ON THE
BACKSIDE OF THE SYSTEM BY 12Z FRI. THUS WILL EXPECT AN IMPROVEMENT
TOWARD VFR CEILINGS BY 18Z FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....PUMA
AVIATION...JP
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AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1251 PM EDT THU MAR 27 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT THU MAR 27 2014
A COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA DURING THE EARLY
MORNING HOURS ON FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE
OHIO VALLEY AROUND FRIDAY NIGHT INTO SATURDAY. ANOTHER FRONTAL
SYSTEM MAY AFFECT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1003 AM EDT THU MAR 27 2014
WITH THE MORNING UPDATE HAVE TRIED TO TREND HOURLY POPS TO BETTER
MATCH OUTPUT OF HRRR AND RAP AS WELL AS LATEST RADAR TRENDS. THIS
DROPPED POPS TO LOW CHANCE CATEGORY FOR THE SOUTHERN COUNTIES
WITHIN THE NEXT COUPLE OF HOURS BUT KEPT CATEGORICAL GOING ACROSS
THE NORTH UNTIL 18Z OR SO BEFORE DROPPING BACK TO CHANCE
EVERYWHERE BY AROUND 21Z. KEPT CHANCE OF THUNDER FOR THE
AFTERNOON BASED ON LOW LEVEL JET FORCING AND SOME ELEVATED
INSTABILITY ADVECTING IN. ALSO ADDED A SLIGHT CHANCE FOR VERY
LIGHT SNOW FOR THE NEXT COUPLE OF HOURS ACROSS THE NORTHEAST BASED
ON OBSERVATIONS AND DUAL POL DATA...BUT SHOULD BE NOTED THAT ANY
WINTRY MIX WILL BE VERY BRIEF AND NO ACCUMULATION OF ANY KIND IS
EXPECTED.
PREVIOUS DISCUSSION FOLLOWS...
OTHERWISE...PRECIPITATION POTENTIAL SHOULD TAIL OFF THIS AFTERNOON
AS THE UPPER DISTURBANCE LIFTS OFF TO THE NORTHEAST. STEEP MID LEVEL
LAPSE RATES BLEED INTO THE AREA LATER THIS AFTERNOON...ALTHOUGH
THERE DOESN/T SEEM TO BE MUCH OF A FOCUS FOR PRECIPITATION LATER
THIS AFTERNOON. WILL KEEP CHANCE POPS FOR SHOWERS/THUNDERSTORMS
GOING THIS AFTERNOON.
STRONG LOW LEVEL JET AROUND 65 KTS EXPECTED TO MOVE INTO THE AREA
LATER TODAY. DON/T THINK THERE IS MUCH OF A THREAT FOR THESE WINDS
TO MIX DOWN TO THE SURFACE DUE TO THE CLOUD COVER AND POOR LOW
LEVEL LAPSE RATES...BUT DO THINK POTENTIAL EXISTS FOR SOME WIND
GUSTS AROUND 35 MPH THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 313 AM EDT THU MAR 27 2014
COLD FRONT IS EXPECTED TO MOVE INTO THE AREA BY THE EARLY MORNING
HOURS ON FRIDAY. WILL GO WITH HIGH POPS FOR SHOWERS/THUNDERSTORMS
TONIGHT GIVEN THE EXPECTED LIFT ALONG A 65-70 KT LOW LEVEL JET
AHEAD OF FRONT AND STEEP MID LEVEL LAPSE RATES. MAY SEE SOME
HIGHER WINDS MIX DOWN TO THE SURFACE IN THE VICINITY OF ANY
SHOWERS...BUT LOW LEVEL LAPSE RATES REMAIN POOR...SO DON/T THINK
THE WINDS WILL GET TOO OUT OF HAND.
WILL PROBABLY SEE A LULL IN THE PRECIPITATION THREAT ON FRIDAY AS
FRONT STALLS OUT SOUTH OF THE OHIO RIVER. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE THROUGH THE AREA BY SATURDAY...WHICH SHOULD HELP TO
INDUCE A SURFACE ALONG THE STALLED OUT FRONT. WILL BRING POPS
BACK INTO THE AREA FRIDAY NIGHT AND SATURDAY. MOST OF THE
PRECIPITATION WITH THIS SYSTEM EXPECTED TO BE IN THE FORM OF
RAIN...HOWEVER THERE IS A POTENTIAL FOR SOME WET SNOW OVER THE
NORTHERN ZONES SATURDAY MORNING.
UNDER CONTINUED STRONG WARM ADVECTION TONIGHT...EXPECTING
TEMPERATURES TO RISE OR HOLD GENERALLY IN THE LOWER TO MIDDLE 50S
UNTIL FRONTAL PASSAGE EARLY SATURDAY MORNING. BASED ON LOW LEVEL
THICKNESS PROGS...THE GFS MOS LOWS FRIDAY NIGHT LOOK TOO COOL...SO
WILL RAISE THEM ABOUT A CATEGORY IN THAT PERIOD. OTHER PERIODS DON/T
LOOK TOO BAD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 335 AM EDT THU MAR 27 2014
A PROGRESSIVE AND SOMEWHAT ZONAL UPPER LEVEL PATTERN WILL BE THE
RULE THROUGH THE LONG TERM. THIS WILL RESULT IN RAIN CHANCES EVERY
COUPLE OF DAYS AS A COUPLE OF FAST MOVING SYSTEMS MOVE ACROSS OUR
REGION.
WEAK HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST SUNDAY FOLLOWED BY
AN AREA OF LOW PRESSURE LATE MONDAY AND MONDAY NIGHT...THEN FOLLOWED
BY A RIDGE OF HIGH PRESSURE TUESDAY AND YET ANOTHER APPROACHING AREA
OF LOW PRESSURE TOWARDS THE END OF DAY 7. AS A RESULT THE BEST
CHANCES OF RAIN WILL BE LATE MONDAY...EARLY MONDAY NIGHT AND AGAIN
LATE WEDNESDAY.
TEMPERATURES WILL BE RATHER MILD THROUGH THE PERIOD AS UPPER FLOW
REMAINS ZONAL. OVERALL A MOS BLEND ON TEMPERATURES SEEM REASONABLE.
ONLY MINOR TWEAKS WERE MADE.
&&
.AVIATION /DISCUSSION FOR 271800Z TAFS/...
ISSUED AT 1234 PM EDT THU MAR 27 2014
VFR CONDITIONS ARE EXPECTED TO DETERIORATE TO MVFR DURING THIS TAF
PERIOD.
NAM SUGGESTS STRONG LLJ TO PUSH ACROSS INDIANA THIS EVENING AHEAD
OF AN AREA OF LOW PRESSURE AND COLD FRONT POISED TO PUSH ACROSS
INDIANA OVERNIGHT. GOOD MOISTURE LOOKS TO REMAIN IN PLACE ACROSS
THE AREA TODAY AS FORECAST SOUNDINGS AND TIME HEIGHT SECTIONS SHOW
GOOD SATURATION AMID GOOD LIFT. WITH CCL/S NEAR 2K-2.5K FEET WILL
TREND TOWARD MVFR CEILINGS TONIGHT IN THE WAKE OF THE FRONTAL
PASSAGE.
TIME HEIGHT SECTIONS SHOW SUBSIDENCE ARRIVING ON NW WINDS ON THE
BACKSIDE OF THE SYSTEM BY 12Z FRI. THUS WILL EXPECT AN IMPROVEMENT
TOWARD VFR CEILINGS BY 18Z FRIDAY.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1022 AM EDT THU MAR 27 2014
.UPDATE...
AVIATION SECTIONS UPDATED.
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT THU MAR 27 2014
A COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA DURING THE EARLY
MORNING HOURS ON FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE
OHIO VALLEY AROUND FRIDAY NIGHT INTO SATURDAY. ANOTHER FRONTAL
SYSTEM MAY AFFECT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1003 AM EDT THU MAR 27 2014
WITH THE MORNING UPDATE HAVE TRIED TO TREND HOURLY POPS TO BETTER
MATCH OUTPUT OF HRRR AND RAP AS WELL AS LATEST RADAR TRENDS. THIS
DROPPED POPS TO LOW CHANCE CATEGORY FOR THE SOUTHERN COUNTIES
WITHIN THE NEXT COUPLE OF HOURS BUT KEPT CATEGORICAL GOING ACROSS
THE NORTH UNTIL 18Z OR SO BEFORE DROPPING BACK TO CHANCE
EVERYWHERE BY AROUND 21Z. KEPT CHANCE OF THUNDER FOR THE
AFTERNOON BASED ON LOW LEVEL JET FORCING AND SOME ELEVATED
INSTABILITY ADVECTING IN. ALSO ADDED A SLIGHT CHANCE FOR VERY
LIGHT SNOW FOR THE NEXT COUPLE OF HOURS ACROSS THE NORTHEAST BASED
ON OBSERVATIONS AND DUAL POL DATA...BUT SHOULD BE NOTED THAT ANY
WINTRY MIX WILL BE VERY BRIEF AND NO ACCUMULATION OF ANY KIND IS
EXPECTED.
PREVIOUS DISCUSSION FOLLOWS...
OTHERWISE...PRECIPITATION POTENTIAL SHOULD TAIL OFF THIS AFTERNOON
AS THE UPPER DISTURBANCE LIFTS OFF TO THE NORTHEAST. STEEP MID LEVEL
LAPSE RATES BLEED INTO THE AREA LATER THIS AFTERNOON...ALTHOUGH
THERE DOESN/T SEEM TO BE MUCH OF A FOCUS FOR PRECIPITATION LATER
THIS AFTERNOON. WILL KEEP CHANCE POPS FOR SHOWERS/THUNDERSTORMS
GOING THIS AFTERNOON.
STRONG LOW LEVEL JET AROUND 65 KTS EXPECTED TO MOVE INTO THE AREA
LATER TODAY. DON/T THINK THERE IS MUCH OF A THREAT FOR THESE WINDS
TO MIX DOWN TO THE SURFACE DUE TO THE CLOUD COVER AND POOR LOW
LEVEL LAPSE RATES...BUT DO THINK POTENTIAL EXISTS FOR SOME WIND
GUSTS AROUND 35 MPH THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 313 AM EDT THU MAR 27 2014
COLD FRONT IS EXPECTED TO MOVE INTO THE AREA BY THE EARLY MORNING
HOURS ON FRIDAY. WILL GO WITH HIGH POPS FOR SHOWERS/THUNDERSTORMS
TONIGHT GIVEN THE EXPECTED LIFT ALONG A 65-70 KT LOW LEVEL JET
AHEAD OF FRONT AND STEEP MID LEVEL LAPSE RATES. MAY SEE SOME
HIGHER WINDS MIX DOWN TO THE SURFACE IN THE VICINITY OF ANY
SHOWERS...BUT LOW LEVEL LAPSE RATES REMAIN POOR...SO DON/T THINK
THE WINDS WILL GET TOO OUT OF HAND.
WILL PROBABLY SEE A LULL IN THE PRECIPITATION THREAT ON FRIDAY AS
FRONT STALLS OUT SOUTH OF THE OHIO RIVER. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE THROUGH THE AREA BY SATURDAY...WHICH SHOULD HELP TO
INDUCE A SURFACE ALONG THE STALLED OUT FRONT. WILL BRING POPS
BACK INTO THE AREA FRIDAY NIGHT AND SATURDAY. MOST OF THE
PRECIPITATION WITH THIS SYSTEM EXPECTED TO BE IN THE FORM OF
RAIN...HOWEVER THERE IS A POTENTIAL FOR SOME WET SNOW OVER THE
NORTHERN ZONES SATURDAY MORNING.
UNDER CONTINUED STRONG WARM ADVECTION TONIGHT...EXPECTING
TEMPERATURES TO RISE OR HOLD GENERALLY IN THE LOWER TO MIDDLE 50S
UNTIL FRONTAL PASSAGE EARLY SATURDAY MORNING. BASED ON LOW LEVEL
THICKNESS PROGS...THE GFS MOS LOWS FRIDAY NIGHT LOOK TOO COOL...SO
WILL RAISE THEM ABOUT A CATEGORY IN THAT PERIOD. OTHER PERIODS DON/T
LOOK TOO BAD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 335 AM EDT THU MAR 27 2014
A PROGRESSIVE AND SOMEWHAT ZONAL UPPER LEVEL PATTERN WILL BE THE
RULE THROUGH THE LONG TERM. THIS WILL RESULT IN RAIN CHANCES EVERY
COUPLE OF DAYS AS A COUPLE OF FAST MOVING SYSTEMS MOVE ACROSS OUR
REGION.
WEAK HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST SUNDAY FOLLOWED BY
AN AREA OF LOW PRESSURE LATE MONDAY AND MONDAY NIGHT...THEN FOLLOWED
BY A RIDGE OF HIGH PRESSURE TUESDAY AND YET ANOTHER APPROACHING AREA
OF LOW PRESSURE TOWARDS THE END OF DAY 7. AS A RESULT THE BEST
CHANCES OF RAIN WILL BE LATE MONDAY...EARLY MONDAY NIGHT AND AGAIN
LATE WEDNESDAY.
TEMPERATURES WILL BE RATHER MILD THROUGH THE PERIOD AS UPPER FLOW
REMAINS ZONAL. OVERALL A MOS BLEND ON TEMPERATURES SEEM REASONABLE.
ONLY MINOR TWEAKS WERE MADE.
&&
.AVIATION /DISCUSSION FOR THE 271500Z/...
VFR CONDITIONS ARE EXPECTED TO CONTINUE THE NEXT SEVERAL HOURS.
RADAR SHOWS SCT LIGHT RAIN SHOWERS ACROSS CENTRAL INDIANA SLOWLY
PUSHING ACROSS THE STATE. HAVE LOWERED WIND GUSTS IN THE NEAR TERM
AS SOME OF THE GUSTIER WINDS SHOULD NOT ARRIVE IN THE AREA UNTIL
THIS AFTERNOON WITH THE ARRIVAL OF THE STRONGER LOWER LEVEL JET.
/DISCUSSION FOR 271200Z TAF ISSUANCE/...
ISSUED AT 700 AM EDT THU MAR 27 2014
MAINLY VFR TODAY WITH FLIGHT CONDITIONS LOWERING TO MVFR OR IFR
CEILINGS LATER TONIGHT.
NUMEROUS LIGHT SHOWERS WILL SPREAD NORTHEAST ACROSS CENTRAL INDIANA
THIS MORNING...HOWEVER LOWER ARE STARTING OUT PRETTY DRY WHICH
SHOULD KEEP CEILINGS MAINLY ABOVE 3 THOUSAND FEET. MODELS INDICATE
A BREAK IN SHOWERS FROM MIDDAY TO VERY EARLY EVENING...FOLLOWED BY
NUMEROUS SHOWERS TONIGHT AS COLD FRONT MOVES THROUGH. WITH THE
ARRIVAL OF THE COLD FRONT CEILINGS WILL LIKELY DROP TO 1 TO 2
THOUSAND FEET NEAR AND BEHIND COLD FRONT.
A FEW THUNDERSHOWERS POSSIBLE LATE THIS AFTERNOON AND EARLY TONIGHT.
HOWEVER AIRMASS IS ONLY SLIGHTLY UNSTABLE AND THUNDERSTORM CHANCES
ARE LOW ENOUGH TO KEEP MENTION OUT OF TAFS FOR NOW.
THERE WILL BE A STRONG SOUTHERLY PRESSURE GRADIENT AS LOW PRESSURE
OVER THE CENTRAL PLAINS TRACKS TOWARDS THE GREAT LAKES. WINDS THIS
MORNING WILL BE SOUTH INCREASING TO 15 TO 20 KNOTS AND THEN SOUTH 20
TO 25 KNOTS THIS AFTERNOON AND EARLY TONIGHT. WINDS WILL GRADUALLY
DECREASE LATER TONIGHT AND ESPECIALLY AFTER COLD FRONT MOVES THROUGH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...JH/JP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1009 AM EDT THU MAR 27 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 313 AM EDT THU MAR 27 2014
A COLD FRONT IS EXPECTED TO PASS ACROSS THE AREA DURING THE EARLY
MORNING HOURS ON FRIDAY. A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE
OHIO VALLEY AROUND FRIDAY NIGHT INTO SATURDAY. ANOTHER FRONTAL
SYSTEM MAY AFFECT THE AREA EARLY NEXT WEEK.
&&
.NEAR TERM /REST OF TODAY/...
ISSUED AT 1003 AM EDT THU MAR 27 2014
WITH THE MORNING UPDATE HAVE TRIED TO TREND HOURLY POPS TO BETTER
MATCH OUTPUT OF HRRR AND RAP AS WELL AS LATEST RADAR TRENDS. THIS
DROPPED POPS TO LOW CHANCE CATEGORY FOR THE SOUTHERN COUNTIES
WITHIN THE NEXT COUPLE OF HOURS BUT KEPT CATEGORICAL GOING ACROSS
THE NORTH UNTIL 18Z OR SO BEFORE DROPPING BACK TO CHANCE
EVERYWHERE BY AROUND 21Z. KEPT CHANCE OF THUNDER FOR THE
AFTERNOON BASED ON LOW LEVEL JET FORCING AND SOME ELEVATED
INSTABILITY ADVECTING IN. ALSO ADDED A SLIGHT CHANCE FOR VERY
LIGHT SNOW FOR THE NEXT COUPLE OF HOURS ACROSS THE NORTHEAST BASED
ON OBSERVATIONS AND DUAL POL DATA...BUT SHOULD BE NOTED THAT ANY
WINTRY MIX WILL BE VERY BRIEF AND NO ACCUMULATION OF ANY KIND IS
EXPECTED.
PREVIOUS DISCUSSION FOLLOWS...
OTHERWISE...PRECIPITATION POTENTIAL SHOULD TAIL OFF THIS AFTERNOON
AS THE UPPER DISTURBANCE LIFTS OFF TO THE NORTHEAST. STEEP MID LEVEL
LAPSE RATES BLEED INTO THE AREA LATER THIS AFTERNOON...ALTHOUGH
THERE DOESN/T SEEM TO BE MUCH OF A FOCUS FOR PRECIPITATION LATER
THIS AFTERNOON. WILL KEEP CHANCE POPS FOR SHOWERS/THUNDERSTORMS
GOING THIS AFTERNOON.
STRONG LOW LEVEL JET AROUND 65 KTS EXPECTED TO MOVE INTO THE AREA
LATER TODAY. DON/T THINK THERE IS MUCH OF A THREAT FOR THESE WINDS
TO MIX DOWN TO THE SURFACE DUE TO THE CLOUD COVER AND POOR LOW
LEVEL LAPSE RATES...BUT DO THINK POTENTIAL EXISTS FOR SOME WIND
GUSTS AROUND 35 MPH THIS AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
ISSUED AT 313 AM EDT THU MAR 27 2014
COLD FRONT IS EXPECTED TO MOVE INTO THE AREA BY THE EARLY MORNING
HOURS ON FRIDAY. WILL GO WITH HIGH POPS FOR SHOWERS/THUNDERSTORMS
TONIGHT GIVEN THE EXPECTED LIFT ALONG A 65-70 KT LOW LEVEL JET
AHEAD OF FRONT AND STEEP MID LEVEL LAPSE RATES. MAY SEE SOME
HIGHER WINDS MIX DOWN TO THE SURFACE IN THE VICINITY OF ANY
SHOWERS...BUT LOW LEVEL LAPSE RATES REMAIN POOR...SO DON/T THINK
THE WINDS WILL GET TOO OUT OF HAND.
WILL PROBABLY SEE A LULL IN THE PRECIPITATION THREAT ON FRIDAY AS
FRONT STALLS OUT SOUTH OF THE OHIO RIVER. ANOTHER UPPER TROUGH IS
EXPECTED TO MOVE THROUGH THE AREA BY SATURDAY...WHICH SHOULD HELP TO
INDUCE A SURFACE ALONG THE STALLED OUT FRONT. WILL BRING POPS
BACK INTO THE AREA FRIDAY NIGHT AND SATURDAY. MOST OF THE
PRECIPITATION WITH THIS SYSTEM EXPECTED TO BE IN THE FORM OF
RAIN...HOWEVER THERE IS A POTENTIAL FOR SOME WET SNOW OVER THE
NORTHERN ZONES SATURDAY MORNING.
UNDER CONTINUED STRONG WARM ADVECTION TONIGHT...EXPECTING
TEMPERATURES TO RISE OR HOLD GENERALLY IN THE LOWER TO MIDDLE 50S
UNTIL FRONTAL PASSAGE EARLY SATURDAY MORNING. BASED ON LOW LEVEL
THICKNESS PROGS...THE GFS MOS LOWS FRIDAY NIGHT LOOK TOO COOL...SO
WILL RAISE THEM ABOUT A CATEGORY IN THAT PERIOD. OTHER PERIODS DON/T
LOOK TOO BAD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 335 AM EDT THU MAR 27 2014
A PROGRESSIVE AND SOMEWHAT ZONAL UPPER LEVEL PATTERN WILL BE THE
RULE THROUGH THE LONG TERM. THIS WILL RESULT IN RAIN CHANCES EVERY
COUPLE OF DAYS AS A COUPLE OF FAST MOVING SYSTEMS MOVE ACROSS OUR
REGION.
WEAK HIGH PRESSURE WILL MOVE ACROSS THE MIDWEST SUNDAY FOLLOWED BY
AN AREA OF LOW PRESSURE LATE MONDAY AND MONDAY NIGHT...THEN FOLLOWED
BY A RIDGE OF HIGH PRESSURE TUESDAY AND YET ANOTHER APPROACHING AREA
OF LOW PRESSURE TOWARDS THE END OF DAY 7. AS A RESULT THE BEST
CHANCES OF RAIN WILL BE LATE MONDAY...EARLY MONDAY NIGHT AND AGAIN
LATE WEDNESDAY.
TEMPERATURES WILL BE RATHER MILD THROUGH THE PERIOD AS UPPER FLOW
REMAINS ZONAL. OVERALL A MOS BLEND ON TEMPERATURES SEEM REASONABLE.
ONLY MINOR TWEAKS WERE MADE.
&&
.AVIATION /DISCUSSION FOR 271200Z TAF ISSUANCE/...
ISSUED AT 700 AM EDT THU MAR 27 2014
MAINLY VFR TODAY WITH FLIGHT CONDITIONS LOWERING TO MVFR OR IFR
CEILINGS LATER TONIGHT.
NUMEROUS LIGHT SHOWERS WILL SPREAD NORTHEAST ACROSS CENTRAL INDIANA
THIS MORNING...HOWEVER LOWER ARE STARTING OUT PRETTY DRY WHICH
SHOULD KEEP CEILINGS MAINLY ABOVE 3 THOUSAND FEET. MODELS INDICATE
A BREAK IN SHOWERS FROM MIDDAY TO VERY EARLY EVENING...FOLLOWED BY
NUMEROUS SHOWERS TONIGHT AS COLD FRONT MOVES THROUGH. WITH THE
ARRIVAL OF THE COLD FRONT CEILINGS WILL LIKELY DROP TO 1 TO 2
THOUSAND FEET NEAR AND BEHIND COLD FRONT.
A FEW THUNDERSHOWERS POSSIBLE LATE THIS AFTERNOON AND EARLY TONIGHT.
HOWEVER AIRMASS IS ONLY SLIGHTLY UNSTABLE AND THUNDERSTORM CHANCES
ARE LOW ENOUGH TO KEEP MENTION OUT OF TAFS FOR NOW.
THERE WILL BE A STRONG SOUTHERLY PRESSURE GRADIENT AS LOW PRESSURE
OVER THE CENTRAL PLAINS TRACKS TOWARDS THE GREAT LAKES. WINDS THIS
MORNING WILL BE SOUTH INCREASING TO 15 TO 20 KNOTS AND THEN SOUTH 20
TO 25 KNOTS THIS AFTERNOON AND EARLY TONIGHT. WINDS WILL GRADUALLY
DECREASE LATER TONIGHT AND ESPECIALLY AFTER COLD FRONT MOVES THROUGH.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/CP
SHORT TERM...JAS
LONG TERM....JH
AVIATION...MK/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
100 AM EDT THU MAR 27 2014
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 355 PM EDT WED MAR 26 2014
A FAIRLY PROGRESSIVE PATTERN WILL BE IN PLACE ACROSS MUCH OF THE
COUNTRY...WITH LOW PRESSURE SYSTEMS MOVING THROUGH THE REGION
EVERY COUPLE OF DAYS THROUGH THE PERIOD. THUNDERSTORMS WILL BE
POSSIBLE THURSDAY AFTERNOON AND OVERNIGHT...AND WIND GUSTS TO 40 MPH
CAN BE EXPECTED THURSDAY.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 929 PM EDT WED MAR 26 2014
FOR THE UPDATE...PUSHED BACK CHANCES FOR RAIN MOVING IN BY A
COUPLE MORE HOURS UNTIL 10Z IN THE WEST BASED ON CURRENT TRENDS
FROM THE RAP AND HRRR. ALSO THINK IT MAY TAKE A BIT LONGER FOR
COLUMN TO SATURATE WITH EXTREMELY DRY AIR IN PLACE AT THE SURFACE
AS EVIDENCED IN DEW POINTS STILL IN THE TEENS AND FORECAST
SOUNDINGS SHOWING DRY AIR ALOFT AS WELL. DROPPED LOW TEMPERATURES
A COUPLE DEGREES IN THE LOW SPOTS AS SOME ARE ALREADY HITTING
THEIR FORECAST LOWS...BUT ONLY DROPPED BY A BIT AS WARM ADVECTION
SHOULD REALLY START AMPING UP AND EXPECT TEMPERATURES TO AT LEAST
REMAIN STEADY IF NOT RISE A BIT STARTING WITHIN THE NEXT HOUR OR
TWO. SOUNDINGS STILL INDICATE POTENTIAL FOR A BRIEF PERIOD OF
MIXED PRECIP FROM EVAPORATIONAL COOLING AT PRECIP ONSET...BUT
CONTINUE TO THINK THIS WOULD BE BRIEF ENOUGH TO LEAVE OUT AT THIS
TIME. PREVIOUS DISCUSSION FOLLOWS...
GUIDANCE IS FAIRLY CONSISTENT IN KEEPING DRY CONDITIONS ACROSS THE
AREA THIS EVENING AND INTO THE EARLY PART OF THE OVERNIGHT. BEGAN
LOW POPS IN THE FAR WEST AFTER ABOUT 08Z...KEEPING CENTRAL AND
EASTERN FORECAST AREA DRY THROUGH 12Z. MID AND HIGH CLOUD WILL BE
INCREASING AHEAD OF THE LEAD UPPER LEVEL WAVE AS IT APPROACHES
FROM THE SOUTHWEST.
TEMPS OVERNIGHT WILL LIKELY MAKE THE UPPER 20S TO LOW 30S...AND
CONSENSUS HANDLED THIS WELL. WOULD NOT BE SURPRISED TO SEE A VERY
BRIEF PERIOD OF MIXED PRECIP ON THE LEADING EDGE OF THE RAIN OWING
TO WETBULB EFFECTS...BUT THIS IS LOW PROBABILITY ENOUGH TO BE LEFT
TO NOWCASTING AND UPDATES AS NEEDED.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 355 PM EDT WED MAR 26 2014
LIKELY OR HIGHER POPS JUSTIFIED ACROSS MUCH OF THE AREA AGAIN
TOMORROW AND TOMORROW NIGHT...AND SREF PROBABILITIES IN
COMBINATION WITH CORE OF THE 850 JET AND LOW LEVEL WARM ADVECTION
SUGGEST THUNDER POTENTIAL EXISTS TOMORROW AFTERNOON AND OVERNIGHT.
MARGINAL SEVERE RISK COMES RIGHT UP TO OUR WESTERN BORDER IN DAY
2...AND THIS IS REASONABLE BASED PURELY ON DYNAMIC STRENGTH ALONE.
ANOTHER LOW WILL SKIRT WELL TO OUR SOUTH FRIDAY NIGHT INTO
SATURDAY. LOW LEVEL THERMAL PROGS SUGGEST POSSIBLE MIXING WITH
SOME SNOW ACROSS OUR NORTH FRIDAY NIGHT. SOME MODELS WANT TO
CONTINUE THIS SATURDAY BUT THIS APPEARS UNLIKELY WITH HIGHS
EXPECTED AROUND 40...ALTHOUGH A BRIEF TIME IN THE MORNING HOURS
WOULD NOT BE ENTIRELY OUT OF THE QUESTION. ANY SIGNIFICANT
ACCUMULATION IS UNLIKELY AT THIS POINT.
CONSENSUS NUMBERS APPEARED REASONABLE FOR TEMPS AND FEW CHANGES
WERE REQUIRED.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ISSUED AT 235 PM EDT WED MAR 26 2014
PROGRESSIVE UPPER LEVEL PATTERN SETTING UP THROUGH THE EXTENDED WITH
THE POTENTIAL FOR RAINFALL TO IMPACT CENTRAL INDIANA EVERY COUPLE
DAYS.
LOW PRESSURE THAT WILL BRING THE PRECIPITATION ON SATURDAY WILL BE
MOVING AWAY SATURDAY NIGHT AS A HIGH PRESSURE RIDGE EXPANDS INTO THE
REGION. THE COMBINATION OF THE SURFACE HIGH WITH A REESTABLISHMENT
OF UPPER RIDGING WILL BRING PLEASANT MILD CONDITIONS FOR SUNDAY. A
FAST MOVING UPPER LEVEL WAVE WITH AN ASSOCIATED SURFACE LOW AND COLD
FRONT WILL QUICKLY MOVE ACROSS THE GREAT LAKES MONDAY/MONDAY
NIGHT...BRINGING SCATTERED RAIN SHOWERS TO CENTRAL INDIANA. TEMPS
AHEAD OF THE FRONT ON MONDAY LIKELY TO WARM INTO THE 60S. APRIL IS
SET TO START COOL AND DRY WITH HIGHS MAINLY IN THE UPPER 40S/LOWER
50S AS CANADIAN HIGH PRESSURE BUILDS BACK INTO THE REGION ON
TUESDAY. CHANCES FOR RAIN WILL INCREASE ONCE AGAIN FOR WEDNESDAY
AS LOW PRESSURE EJECTS OUT INTO THE CENTRAL PLAINS WITH A WARM
FRONT EXTENDING EAST INTO THE OHIO VALLEY.
&&
.AVIATION /DISCUSSION FOR 270600Z TAF ISSUANCE/...
ISSUED AT 100 AM EDT THU MAR 27 2014
CONFIDENCE IS GOOD THAT VFR CONDITIONS SHOULD PREVAIL UNTIL AFTER
00Z FRIDAY WHEN CONDITIONS SHOULD DETERIORATE TO MVFR OR POSSIBLY
LOWER WHEN A COLD FRONT APPROACHES AND MODEL TIME SECTIONS SHOW
MARKED INCREASE IN LOW LEVEL MOISTURE. WOULD ALSO NOT RULE OUT BRIEF
MVFR AFTER 16Z TODAY WITH ANY THUNDERSTORM. HOWEVER...WITH
CAPE...EVEN ELEVATED...WEST OF THE AREA UNTIL AFTER 00Z...WILL LEAVE
THUNDERSTORMS OUT WITH ONLY SHOWERS.
WITH THE LOWER LEVELS EXTREMELY DRY...IT WILL TAKE QUITE AWHILE FOR
ANY RAIN TO REACH THE SURFACE WITH ISENTROPIC ANALYSIS AND RAPID
REFRESH REFLECTIVITY PROGS SUGGESTING SHOULD NOT SEE WIDESPREAD RAIN
UNTIL AFTER 09Z AT HUF AND FURTHER EAST NOT UNTIL 11Z OR LATER AT
IND.
SOUTH WINDS SHOULD INCREASE TO NEAR 20 KNOTS WITH GUSTS TO NEAR 30
KNOTS AS THE RAIN MOVES IN. WOULD NOT RULE OUT WIND SHEAR AT LAF FOR
A BRIEF TIME PRIOR TO THE GUSTS AS A 40 KNOT LOW LEVEL JET SETS UP
THERE...BUT WITH DIRECTIONAL SHEAR LESS THAN 60 DEGREES...WILL LEAVE
IT OUT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/CP
SHORT TERM...NIELD
LONG TERM....RYAN
AVIATION...MK/JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1155 PM CDT WED MAR 26 2014
.UPDATE...
ISSUED AT 955 PM CDT WED MAR 26 2014
HIGHER SUSTAINED WINDS AND GUSTS ARE HOLDING ON LONGER THAN
EXPECTED OVER WRN IA. SUSTAINED SPEEDS ARE STILL 25 TO 40 MPH WITH
GUSTS ROUTINELY OVER 40 MPH. STILL DO NOT FEEL THIS WILL LAST MUCH
LONGER WITH MIXED LAYER DEPTH LOWERING AND RAP SUGGESTING SLP
GRADIENT WILL WEAKEN FURTHER AS WELL. OPTED TO ISSUE SPS INSTEAD
OF ADVISORY...HOPEFULLY DUE TO WHAT WILL BE A LIMITED DURATION.
&&
.SHORT TERM /TONIGHT/...
ISSUED AT 355 PM CDT WED MAR 26 2014
WINDS HAVE INCREASED AS EXPECTED TODAY...OR EVEN A LITTLE MORE
SO...AND THE WIND ADVISORY WAS EXPANDED EARLIER THIS AFTERNOON TO
COVER ABOUT THE NORTHWEST HALF OF THE FORECAST AREA AND RUN THROUGH
8 PM THIS EVENING. WINDS WILL SLOWLY DIMINISH AFTER SUNSET...BUT
REMAIN BREEZY OVERNIGHT WITH A TIGHT PRESSURE GRADIENT IN PLACE. WE
HAVE RECEIVED REPORTS OF BLOWING DUST ACROSS THE NORTHWEST AND OF A
FIRE PRODUCING A SMOKE PLUME SOUTH OF DES MOINES...SO CERTAINLY THE
WINDS ARE PRODUCING IMPACTS ACROSS MUCH OF THE AREA.
MEANWHILE...A PRECIPITATION EVENT REMAINS FORECAST TONIGHT AND IS
EVIDENT UPSTREAM IN THE FORM OF TWO 500 MB WAVES. THE FIRST IS IN
THE SOUTHERN STREAM...AND IS READILY APPARENT AS A LARGE CLOUD FIELD
DEVELOPING ACROSS OK/KS/MO AND MOVING QUICKLY NORTHEAST. HI RES
MODELS ARE TRACKING THIS FEATURE ACROSS OUR SOUTHEAST COUNTIES
AROUND MIDNIGHT WITH SOME LIGHT PRECIP. A LARGER NORTHERN STREAM
WAVE IS FURTHER WEST OVER THE ROCKIES THIS AFTERNOON AND WILL EMERGE
OVER THE HIGH PLAINS BY THURSDAY MORNING. A LARGE ZONE OF LOW LEVEL
WARM AIR AND MOISTURE ADVECTION...ENHANCED BY THE LEADING SOUTHERN
WAVE...WILL SPREAD ACROSS IOWA AFTER SUNSET TONIGHT RESULTING IN
RAPID SATURATION OF THE LOWER LEVELS AS ILLUSTRATED UNANIMOUSLY BY
FORECAST SOUNDINGS. THIS WILL RESULT IN RAPIDLY DEVELOPING LOW
CLOUDS...LIGHT RAIN...AND FOG ALTHOUGH VISIBILITY WILL NOT DROP
TERRIBLY LOW DUE TO THE WIND SPEEDS. MOST FORECAST MODELS ALSO
INDICATE ELEVATED INSTABILITY OVERNIGHT SO ISOLATED THUNDERSTORMS
ARE EXPECTED AND INCLUDED IN THE FORECAST...HOWEVER SEVERE WEATHER
IS NOT ANTICIPATED. RAINFALL AMOUNTS WILL GENERALLY BE LIGHT AND OF
LITTLE IMPACT BUT IT WILL MAKE FOR A DAMP AND HAZY NIGHT ACROSS THE
AREA...ESPECIALLY AFTER MIDNIGHT.
.LONG TERM /THURSDAY THROUGH WEDNESDAY/...
ISSUED AT 355 PM CDT WED MAR 26 2014
A INTENSE EARLY SPRING LOW LEVEL JET WILL BE FOCUSED INTO IOWA
EARLY THURSDAY WITH MUCAPES OF 200-600 J/KG. GOOD STEEP MID LEVEL
LAPSE RATES BETWEEN 700-300 MB WILL BE IN PLACE DURING THIS TIME
AND SHOULD AID IN WIDESPREAD PRECIPITATION WITH EMBEDDED
THUNDERSTORMS EARLY. WITH LOW MELTING LEVELS AND THE STEEP LAPSE
RATES...A FEW STORMS PRODUCING HAIL MAY OCCUR. THE INSTABILITY
WILL LINGER INTO THE AFTERNOON THOUGH INCREASING MOISTURE AND
SATURATION WILL CAUSE LAPSE RATES TO DIMINISH INTO THE AFTERNOON
FOR CENTRAL AND NORTHERN IOWA. GIVEN THE SFC LOW TRACK INTO SOUTH
CENTRAL IOWA...THERE IS THE POTENTIAL FOR SFC BASED CONVECTION TO
BE REALIZED AS THE MID LEVEL WARM LAYER DIMINISHES. STILL
SATURATION THROUGH THE PROFILES WOULD RESULT IN LONG AND SKINNY
CAPES WHICH WOULD LIMIT THE HAIL THREAT THROUGH A 60 MPH WIND
GUSTS IS POSSIBLE. THE COLDER AIR WILL MOVE INTO NORTHERN IOWA
DURING THE AFTERNOON AS THE SFC LOW PRESSURE SHIFTS INTO
SOUTHEAST IOWA. A CHANGE OVER FROM RAIN TO SNOW WILL OCCUR BUT AS
MENTIONED YESTERDAY...DRIER AIR WILL BE ARRIVING SOON AFTER ANY
TRANSITION. MAY SEE AN INCH OR SO IN SOME LOCATIONS WITH THE
POTENTIAL FOR MORE QUITE LIMITED.
THE PRECIPITATION WILL SHIFT TO THE EAST DURING THURSDAY EVENING.
FRIDAY IS EXPECTED TO BE PRIMARILY DRY WITH HIGHS IN THE 30S AND
40S. ANOTHER SHORT WAVE WILL MOVE ACROSS BY FRIDAY EVENING. THE
LOW LEVELS WILL REMAIN DRY DURING THIS PERIOD AND WILL LIMIT
THE PRECIPITATION POTENTIAL. HAVE CONTINUED ONLY LOW POPS FRIDAY
EVENING OVER THE FAR SOUTHEAST WHERE SATURATION IS BETTER. POPS
MAY NEED TO BE INCREASED ELSEWHERE IF BETTER SATURATION IS
IDENTIFIED ELSEWHERE. A RIDGE OF HIGH PRESSURE WILL PASS THROUGH
ON SATURDAY WITH WARM ADVECTION DEVELOPING BY THE AFTERNOON. THE
THERMAL RIDGE IS STILL ON TARGET TO BE OVERHEAD ON SUNDAY. HAVE
INCREASED HIGH TEMPERATURES EVEN FURTHER WITH GOOD MIXING
DEVELOPING. SHOULD HAVE A FEW SITES REACH 70. HAVE CONTINUED
TRENDS FOR MONDAY WITH A MORE OPEN WAVE SOLUTION WITH THE PRIMARY
SNOW POTENTIAL NORTH INTO MINNESOTA. DID NOT INCLUDE THUNDERSTORMS
WITH THIS SYSTEM...BUT POTENTIAL IS THERE IS THE BOUNDARY MOVES
THROUGH AT PEAK HEATING. THE TRANSITION TO A MORE PROGRESSIVE
ZONAL FLOW NEXT WEEK WITH NUMEROUS STRONG SYSTEM PASSING THROUGH.
DEVELOPING SOUTHWEST FLOW BY WEDNESDAY WOULD SUPPORT THUNDERSTORMS
AND EVEN SEVERE WEATHER. CURRENT MODEL GUIDANCE IS KEEPING THE
WARM FRONT JUST TO THE SOUTH OF THE STATE. WILL BE INTERESTING TO
SEE WHAT IMPACT THE FROZEN GREAT LAKES WILL HAVE ON THE POTENTIAL
FOR WARM FRONTS LIFTING NORTH. THIS EVENT WOULD SUPPORT NORTHEAST
FLOW OFF THE LAKES AND POINTING TOWARD IOWA AND LIMIT THE
NORTHWARD EXTENT OF THE BOUNDARY.
&&
.AVIATION...27/06Z
ISSUED AT 1155 PM CDT WED MAR 26 2014
MVFR CIGS CONTINUE TO ADVANCE NEWD THROUGH TAF SITES...CURRENTLY
AFFECTING KFOD AND KDSM...AND KMCW/KALO/KOTM VERY SHORTLY. THIS
WILL ALSO BE COINCIDENT WITH A PERIOD OF DRIZZLE AND CIGS
CONTINUING TO LOWER TO IFR. MORE CONVECTIVE SHOWERS MAY DEVELOP
THU MORNING...BUT CONFIDENCE IN INCLUDING THUNDER IS NOT GREAT
ENOUGH TO MENTION AT THIS POINT. SURFACE LOW IS EXPECTED TO TRACK
RIGHT THROUGH CENTRAL IA WITH PRECIP LIKELY SWITCHING BRIEFLY TO
SNOW AT KFOD/KMCW/KALO BEFORE ENDING. AT LEAST MVFR STRATUS IS
EXPECTED TO LINGER AT ALL SITES THROUGH VALID PERIOD...EVEN BEHIND
PRECIP.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...LEE
LONG TERM...DONAVON
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1212 AM CDT Thu Mar 27 2014
...Update to aviation...
.SYNOPSIS...
ISSUED AT 1010 PM CDT WED MAR 26 2014
The 27.00Z 250 hPa map showed a 75-100 kt jet from KOAK to KABQ with
a speed max of 100 kt near KFGZ. Another jet of 120 kt was located across
the NE United States. Lastly, a subtropical jet was located across
Mexico, the Gulf Basin, and east to Florida with magnitudes of 80-100
kt. At 500 hPa, the atmosphere was quite perturbed with a low pressure
center just offshore of Washington, a negatively tilted trof across
the Great Basin into the Desert SW. Finally, a very impressive 512 dm
cyclone was located just south of the Canadian Maritimes. At 700 hPa,
downslope WSW flow was noted across KDDC with temp H7 temp at 2C. There
was some moisture advection at 850 hPa and below for KDDC with at 0.56"
pwat now. At the sfc, a warm front was analyzed across far southwest
Kansas. Dewpoints in the lower 40sF managed to advect in association
with a lee trof/lower pressures across eastern Colorado. On a synoptically
interesting note, this synoptician found it very impressive that a 1007
hPa low deepened into a 955 hPa low across the western Atlantic basin...Explosive
cyclogenesis or "bombogenesis". Talk about a very attractive looking
(wrt satellite appearance and dynamics) synoptic wave.
&&
.SHORT TERM...(This evening through Thursday)
ISSUED AT 348 PM CDT WED MAR 26 2014
Main challenge in the forecast tonight will be advisory level wind
speeds and precipitation chances. Today`s wave of precipitation that
grazed southwest Kansas (affecting south-central Kansas) was moving
out late this afternoon, however quick on its heels was another
potent upper tropospheric jet streak. This was already leading to
enhancement in mid and upper level cloud across Colorado. A few
showers and and isolated lightning strike or two will form across
the dry low level airmass of southeastern/east-central Colorado. A
few of these convective elements will move east into far southwest
Kansas this evening, however the real-estate of very limited
convective instability is quite narrow, so it will be extremely
difficult for any of these surface-based showers/isolated
thunderstorm to thrive much past sunset. In fact, the latest runs of
the 3km HRRR model suggest a dissipation of any surface based
activity not long after 00Z.
Surface winds are expected to back around or shortly after 00Z to
the south-southeast ahead of the dryline, and this will allow low
level moisture to pull back west, and widespread low clouds should
form. Light fog may also develop along and east of Highway 283,
however we will keep fog out of the grids for now, as the duration
of low clouds will be limited as winds begin to veer with the low
moving east around or shortly after 06Z.
On Thursday, we will be looking at another fairly windy day behind
the cold front passage, however the gradient behind the low will not
be as intense as we saw ahead of the low today, despite some deeper
mixing to help boost the surface winds. The forecast of 20 to 25
knots sustained in the late morning to early afternoon look pretty
good, however, these winds may need to be increased a bit
approaching yet another wind advisory issuance, perhaps. The
midnight shift will have to look at this closer (especially farther
north toward the I-70 corridor). The airmass behind the front will
have substantial downslope modification, so we will actually see
warmer temperatures tomorrow than what we saw today east of highway
283 (given all the clouds and light rain in this area today). Late
in the afternoon, there is the potential for some virga showers
developing across far west-central KS near the Colorado border as
convective temperature is reached given very chilly mid-level
temperatures (500mb temps of down to -25C and 700mb temps of around
-5C).
.LONG TERM...(Thursday night through Wednesday)
ISSUED AT 115 PM CDT WED MAR 26 2014
The extended period will be characterized by a progressive upper
level westerly flow over central North America. Low amplitude
shortwave troughs will periodically move east over the United States
through the period. The first shortwave during this period will move
out over the central High Plains late Thursday night into Friday
morning. The models have been consistent in keeping the bulk of any
precipitation with this wave confined to northern Kansas where the
better mid level moisture will be. Will keep the chance pops along
I-70 intact early Friday morning but have trimmed back pops a little
bit on the southern edge in southwest Kansas.
Later in the period, another shortwave will move out over the
central High Plains around Sunday night with a Pacific cold front
pushing across western Kansas during the afternoon or evening hours.
A few showers and thunderstorms could develop toward central Kansas
depending on whether enough return flow moisture can make it back
into Kansas. A potentially better chance for thunderstorms could
occur across western Kansas as the GFS and ECMWF are showing better
low level moisture return into the central High Plains ahead of this
system.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1212 PM CDT THU MAR 27 2014
Overnight MVFR/IFR cigs expected for KDDC. IFR/MVFR at KHYS. Generally
VFR at KGCK. The lowest of cigs should improve by morning. This is in
association with moisture advection/low stratus. Fropa AM with southerly
winds veering southwesterly and eventually northwesterly as the density
gradient traverses across the terminals. Magnitudes are on the higher
side (15-30 kt) as the gradient wind will remain up due to the eastward
progression of a sfc low pressure perturbation.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 43 62 34 59 / 10 10 20 20
GCK 41 62 35 61 / 20 10 20 20
EHA 43 67 37 61 / 20 10 10 0
LBL 43 67 36 62 / 20 10 10 10
HYS 42 58 33 57 / 20 30 20 20
P28 44 67 35 61 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Sugden
SHORT TERM...Umscheid
LONG TERM...Gerard
AVIATION...Sugden
AREA FORECAST DISCUSSION
NWS JACKSON KY
740 PM EDT FRI MAR 28 2014
.UPDATE...
ISSUED AT 740 PM EDT FRI MAR 28 2014
LATEST HRRR AND RAP BOTH BACKING OFF ON PRECIPITATION CHANCES THROUGH
THE OVERNIGHT HOURS. THE EXCEPTION IS IN A NARROW CORRIDOR ALONG THE
STALLED OUT FRONTAL BOUNDARY DRAPED FROM JUST SOUTH OF
HUNTINGTON...AND NEARLY ALONG THE I-64 CORRIDOR. THESE SHOWERS HAVE
DEVELOPED AMIDST A CONVERGENCE ZONE...AND SOME INSTABILITY. THIS
ACTIVITY SHOULD WANE AS WE HEAD INTO THE LATE EVENING HOURS...LEAVING
THE AREA DRY THROUGH MUCH OF THE OVERNIGHT PERIOD. SOME RAIN MAY
CREEP INTO THE I-75 CORRIDOR TOWARDS DAWN AHEAD OF THE MAIN LOBE OF
ENERGY EXPECTED TO CROSS THE AREA SATURDAY MORNING. UNTIL THIS
HAPPENS...IT LOOKS LIKE A DRIER FORECAST IS ON TAP TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 400 PM EDT FRI MAR 28 2014
A COLD FRONT HAS SLOWED ITS SOUTH AND EAST PROGRESS AS AN AREA OF LOW
PRESSURE IS BEGINNING TO TAKE SHAPE OVER TX IN RESPONSE TO THE NEXT
SHORTWAVE MOVING ACROSS THE PLAINS. THIS SHORTWAVE TROUGH WILL
GRADUALLY WORK EAST TO MS RIVER VALLEY AND ENTER THE LOWER OH VALLEY
TONIGHT AND THEN INTO THE EASTERN CONUS THROUGH THE END OF THE PERIOD.
THE SOUTHERN END OF THE TROUGH IS FORECAST TO CLOSE OFF AND MOVE
ACROSS THE AREA LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT. THE SFC
LOW IS EXPECTED TO TRACK TO THE CUMBERLAND PLATEAU IN TN BY DAWN ON
SATURDAY. THE 12Z GFS IS GENERALLY THE STRONGEST WITH THE SFC LOW AT
THAT POINT. THE SFC LOW SHOULD MOVE ACROSS THE SOUTHEAST PART OF THE
AREA ON SATURDAY MORNING AND DEEPEN TO ABOUT 995 MB PER THE 12Z ECMWF
AND 12Z GFS AS THE UPPER LOW DEVELOPS AND REACH THE DELMARVA BY THE
END OF THE PERIOD.
DESPITE THE MID LEVEL HEIGHT RISES CAPPING OFF CONVECTION THIS AFTERNOON
FROM BRIEF SHORTWAVE RIDGING...THERE IS ENOUGH LOW LEVEL INSTABILITY
FOR EXTENSIVE CU AND STRATOCU AND SOME SHOWERS. THESE FEW SHOWERS
HAVE RECENTLY DEVELOP NEAR THE STALLING BOUNDARY AS MODEL GUIDANCE
HAD SUGGESTED. SOME ISOLATED SHOWERS WILL REMAIN POSSIBLE THIS
EVENING...BEFORE MOISTURE AND LIFT INCREASE AHEAD OF THE UPPER LEVEL
TROUGH AND SFC WAVE TO TRACK NORTHEAST INTO THE TN VALLEY AND THEN
INTO THE REGION BY EARLY ON SATURDAY. THE 12Z ECMWF AND GFS GUIDANCE
SUGGEST VERY LITTLE IF ANY MEASURABLE PRECIPITATION TONIGHT WITH SOME
DOWNSLOPE FLOW ACROSS MUCH OF THE AREA. HOWEVER... THE NAM AND 9Z AND
15Z SREF WERE IN THE LIKELY TO CAT RANGE IN MOST AREAS ACROSS THE
REGION. PERSISTENCE AND ISC COLLABORATION LED TO CATEGORICAL POPS
LATE IN ALL BUT THE BIG SANDY REGION. QPF TONIGHT WILL BE LIGHTER AND
MUCH MORE SIGNIFICANT WELL WEST OF THE REGION AND WEST OF THE
ANTICIPATED SFC LOW TRACK.
AS THE SFC LOW TRACKS INTO WV THROUGH EARLY SAT AFTERNOON SOME COLDER
AIR WILL BEGIN TO BE WRAPPED SOUTHEAST TOWARD THE REGION. A BAND OF
SHOWERS OR RAIN WILL SHIFT EAST INTO EASTERN KY BY THE DAY ON
SATURDAY. THIS SHOULD LEAD TO THE MOST WIDESPREAD PRECIP ACROSS THE
REGION ON SATURDAY MORNING...WITH SOME DRY SLOTTING IN THE AFTERNOON
TO EARLY EVENING...ESPECIALLY IN THE SOUTH AND SOUTHEAST. ELEVATED
INSTABILITY DOES LINGER INTO SAT AM...SO AN ISOLATED RUMBLE OR TWO OF
THUNDER CANNOT BE RULED OUT. TEMPERATURES WILL BE WARMEST IN THE AM
AS THE SFC LOW MOVES ACROSS THE REGION AND THEN TEMPS WILL BEGIN TO
DROP OFF DURING SAT AFTERNOON. TEMPS SHOULD REACH THE UPPER 30S TO
LOW 40S ACROSS THE NORTH AND HIGHEST TERRAIN BY LATE AFTERNOON.
AS THE SOUTHERN PORTION OF THE SHORTWAVE TROUGH CLOSES OFF INTO A
CLOSED UPPER LEVEL LOW AND MOVES EAST INTO THE CENTRAL AND SOUTHERN
APPALACHIANS... FURTHER COLD AIR ADVECTION AND INSTABILITY AS WELL AS
UPSLOPE FLOW WILL LEAD TO ANOTHER ROUND OF SHOWERS MOVING ACROSS THE
AREA FROM SAT EVENING INTO WELL INTO SAT NIGHT. THE NON NAM GUIDANCE
SUGGESTS SOME DECENT QPF...WHILE THE THERMAL PROFILE GRADUALLY MOVES
TOWARD ONE SUPPORTIVE OF SNOW SHOWERS...FIRST ACROSS THE FAR NW AND
HIGHEST TERRAIN NEAR THE VA LINE AND THEN INTO THE LOWER
ELEVATIONS...POSSIBLY BEFORE THE SHOWER CHANCES END. THE COLLING
WOULD COME FROM A COMBINATION OF COLD ADVECTION...COOLING FROM LIFT
AND SOME WETBULBING. WITH THE UPPER LOW TRACKING ACROSS THE AREA AT
NIGHT...AND ANY SNOW GENERALLY FALLING AT NIGHT AS WELL SOME
ACCUMULATION WILL BE POSSIBLE. MOST LOCATIONS WILL NOT GET MORE THAN
A DUSTING... IF THAT FROM THIS. HOWEVER...LIGHT ACCUMULATIONS WILL BE
POSSIBLE...PARTICULARLY RIDGES AT 2000 FEET AND ABOVE. AMOUNTS AT
THESE HIGHEST ELEVATIONS COULD EXCEED 1 INCH WITH THE TOP OF BLACK
MTN OR PINE MTN AND PERHAPS THE FLATWOODS AREA OF PIKE COUNTY GETTING
AS MUCH AS 2 TO 3 INCHES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 PM EDT FRI MAR 28 2014
THE EXTENDED FORECAST PERIOD BEGINS WITH THE MODELS IN VERY GOOD
AGREEMENT. ON SUNDAY THE WILL BE AN UPPER LOW OVER SOUTH CENTRAL
VIRGINIA. AT THE SURFACE...THE WRAP AROUND MOISTURE SHOULD SHOULD BE
MOVING OUT OF THE AREA AND THE THE PRECIPITATION SHOULD BE ENDING.
THE UPPER LOW WILL CONTINUE MOVING TO THE NORTHEAST AND THE NEXT
SYSTEM WILL START MOVING TOWARD THE AREA. AS THE SYSTEM APPROACHES
ON TUESDAY NIGHT...AN UPPER LOW WILL START DIGGING IN OVER THE WEST
COAST. THIS WILL TEND THE KEEP THE FRONT FAIR STATIONARY NEAR
EASTERN KENTUCKY. AT THIS TIME THE FRONT WILL BE FAIRLY WEAK AND
IT WILL RESULT MOSTLY IN CLOUDS. THERE IS QUITE A BIT OF UNCERTAINTY
AS TO EXACTLY WHERE THE FRONT WILL STALL OUT. AS THE UPPER TROUGH
OUT WEST CONTINUES TOWARD THE AREA...THE FRONT WILL DEFINITELY BE TO
THE NORTH OF THE AREA AND IT WILL KEEP EASTERN KENTUCKY IN THE WARM
SECTOR. THE FRONT WILL BE MOVING VERY SLOWLY INTO AND THROUGH THE
AREA AS WAVE DEVELOP ON THE FRONT OVER THE SOUTH CENTRAL PLAINS AND
KEEP THE FRONT TO THE WEST OF THE AREA. THIS WILL KEEP WARM UNSTABLE
AIR OVER EASTERN KENTUCKY AND WILL ALLOW SOME ISOLATED THUNDERSTORMS
TO ACCOMPANY THE RAIN. THE FRONT IS EXPECTED TO MOVE ACROSS THE AREA
ON THURSDAY NIGHT. BY THE END OF THE PERIOD...THERE MODELS ARE
DIFFERING...SO THE TIMING OF THIS FRONT COULD CHANGE 6-18 HOURS BY
THE TIME IT GETS HERE. THIS WILL KEEP THE HIGH TEMPERATURES NEAR 70
THROUGH THE EXTENDED PERIOD. ADJUSTED THE MODEL BLEND TOWARD THE NEW
ECMWF.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 740 PM EDT FRI MAR 28 2014
WHILE SOME SHALLOW LOW CLOUDS WILL BE POSSIBLE OVERNIGHT...
DOWNSLOPING SOUTHEAST WINDS WILL LIKELY KEEP THESE CLOUDS AT VFR
LEVELS. THE EXCEPTION COULD BE IN SOUTH CENTRAL KENTUCKY...WHERE LESS
INFLUENCE ON DOWNSLOPING FLOW MAY ALLOW FOR A PERIOD OF MVFR CIGS
OVERNIGHT. THIS WOULD MAINLY IMPACT KSME AND PERHAPS KLOZ. RAIN LOOKS
LIKE IT SHOULD NOT AFFECT TAF SITES UNTIL AFTER DAYBREAK SATURDAY
MORNING. AS THE RAIN COMES IN SATURDAY MORNING...CEILINGS WILL LOWER
TO MVFR BEFORE REACHING IFR BY MIDDAY AS THE LOW LEVELS SATURATE. THE
RAIN SHOWERS WILL CONTINUE THROUGH SATURDAY EVENING.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JP
LONG TERM...JJ
AVIATION...KAS
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
929 PM CDT Fri Mar 28 2014
.UPDATE:
Issued at 925 PM CDT Fri Mar 28 2014
Based on latest radar and high res model trends...rainfall tonight
should primarily remain to the east of a KVIH-KIJX line, with the
back/nw edge of the rain possibly setting up over STL metro. Back
edge of the rain over southwest MO has really accelerated east
over the last few hours, which may be due to increase in speed of
the shortwave or perhaps the intense convection further south
altering northward surge of moisture. In any case, regional radar
trends would certainly suggest precip also shutting down sooner
than earlier model guidance suggested. Am working on adjustment of
PoPs to reflect above thinking, and hope to have update out shortly.
Truett
&&
.SHORT TERM: (Through Sunday)
Issued at 255 AM CDT Fri Mar 28 2014
SC deck has been slow to lift north across forecast area today. So
northern portions of forecast area remain mostly cloudy. In the
meantime, next weather system is approaching from the southwest with
mid and high clouds streaming into region. Showers and thunderstorms
associated with system have begun to move into far southwestern
Missouri. System to lift northeast tonight towards Ohio valley, so
best chances of precipitation will be over southern and east central
MO as well as southern IL. Looks like instability to weaken south of
forecast area, so no thunderstorms expected at this time. Lows
tonight will be in the low 30s to low 40s.
Byrd
.LONG TERM: (Saturday through Next Friday)
Issued at 327 PM CDT Fri Mar 28 2014
System to exit region by early Saturday morning with clouds clearing
out as surface ridge builds in. Highs will be in the low 50s far
east to the upper 50s over central and southern MO. Lows Saturday
night will be in the 30s.
On Sunday surface ridge moves off to the east allowing southerly
winds to return to the region and bring in much warmer temperatures.
Highs on Sunday will be in the mid 60s to low 70s.
Next weather system to approach region Sunday night, but models are
a bit slower so backed off on precipitation. Rain to move in on
Monday with highs in the mid 60s to near 70.
Beyond that extended is active with several rounds of precipitation
beginning Tuesday night. Daytime highs in the 50s and 60s through
the rest of the forecast period.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 634 PM CDT Fri Mar 28 2014
Rain continues to work its way northeast from s MO, and in the
near term main question is how far north this rain will reach.
Surface obs over parts of sw MO and the Ozarks seem to be
suggesting that the low level dry air is retarding at least some
of the mid level echo from reaching the ground, with the latest
RAP and HRRR guidance suggesting the northern edge of the rain
shield near the STL metro. Cigs with this precip are expected to
remain VFR due to aforementioned dry low level air. Next, and
perhaps a bigger concern for some aviation purposes, deals with
trends of stratus deck from IA and ne MO into the n half of IL,
which has become stuck beneath weak surface ridging. S edge of
this deck did manage to erode to the north this afternoon, but
movement has become masked by higher clouds streaming into the
region from the southern system. Surface obs seem to suggest that
lower cloud movmement has at least slowed, and as surface low
moves into the TN valley the resultant increase of low level
northerly flow in our area should allow the stratus...with MVFR
cigs...to advect back southward. Under this scenario, MVFR cigs
are expected to persist into Saturday morning in UIN, and return
to COU and STL metro areas late this evening and overnight. Do
expect eventual clearing of this low cloud deck later Saturday
morning as high pressure and drier ams works southeast in the wake
of the TN valley system.
Specifics for KSTL: Northern fringes of rain shield should clip
area in the 03-07z time frame with no vsby restriction and cigs
remaining aoa 5kft. Rain should then move out, with increasing
northerly low level flow allowing stratus deck/MVFR cigs (2-3kft)
over ne MO and c IL to drop back into the area during the predawn
hours, and linger into Saturday morning. Forecast soundings
suggest that these clouds should thin out by early afternoon.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
659 PM CDT Fri Mar 28 2014
.SHORT TERM: (Through Sunday)
Issued at 255 AM CDT Fri Mar 28 2014
SC deck has been slow to lift north across forecast area today. So
northern portions of forecast area remain mostly cloudy. In the
meantime, next weather system is approaching from the southwest with
mid and high clouds streaming into region. Showers and thunderstorms
associated with system have begun to move into far southwestern
Missouri. System to lift northeast tonight towards Ohio valley, so
best chances of precipitation will be over southern and east central
MO as well as southern IL. Looks like instability to weaken south of
forecast area, so no thunderstorms expected at this time. Lows
tonight will be in the low 30s to low 40s.
Byrd
.LONG TERM: (Saturday through Next Friday)
Issued at 327 PM CDT Fri Mar 28 2014
System to exit region by early Saturday morning with clouds clearing
out as surface ridge builds in. Highs will be in the low 50s far
east to the upper 50s over central and southern MO. Lows Saturday
night will be in the 30s.
On Sunday surface ridge moves off to the east allowing southerly
winds to return to the region and bring in much warmer temperatures.
Highs on Sunday will be in the mid 60s to low 70s.
Next weather system to approach region Sunday night, but models are
a bit slower so backed off on precipitation. Rain to move in on
Monday with highs in the mid 60s to near 70.
Beyond that extended is active with several rounds of precipitation
beginning Tuesday night. Daytime highs in the 50s and 60s through
the rest of the forecast period.
Byrd
&&
.AVIATION: (For the 00z TAFs through 00z Saturday Evening)
Issued at 634 PM CDT Fri Mar 28 2014
Rain continues to work its way northeast from s MO, and in the
near term main question is how far north this rain will reach.
Surface obs over parts of sw MO and the Ozarks seem to be
suggesting that the low level dry air is retarding at least some
of the mid level echo from reaching the ground, with the latest
RAP and HRRR guidance suggesting the northern edge of the rain
shield near the STL metro. Cigs with this precip are expected to
remain VFR due to aforementioned dry low level air. Next, and
perhaps a bigger concern for some aviation purposes, deals with
trends of stratus deck from IA and ne MO into the n half of IL,
which has become stuck beneath weak surface ridging. S edge of
this deck did manage to erode to the north this afternoon, but
movement has become masked by higher clouds streaming into the
region from the southern system. Surface obs seem to suggest that
lower cloud movmement has at least slowed, and as surface low
moves into the TN valley the resultant increase of low level
northerly flow in our area should allow the stratus...with MVFR
cigs...to advect back southward. Under this scenario, MVFR cigs
are expected to persist into Saturday morning in UIN, and return
to COU and STL metro areas late this evening and overnight. Do
expect eventual clearing of this low cloud deck later Saturday
morning as high pressure and drier ams works southeast in the wake
of the TN valley system.
Specifics for KSTL: Northern fringes of rain shield should clip
area in the 03-07z time frame with no vsby restriction and cigs
remaining aoa 5kft. Rain should then move out, with increasing
northerly low level flow allowing stratus deck/MVFR cigs (2-3kft)
over ne MO and c IL to drop back into the area during the predawn
hours, and linger into Saturday morning. Forecast soundings
suggest that these clouds should thin out by early afternoon.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
108 PM CDT Thu Mar 27 2014
.UPDATE...
Issued at 101 PM CDT THU MAR 27 2014
After the showers and thunderstorms exit the area late Thursday
evening, a cold front will sweep through the area, bringing brisk NW
winds. Expect a general down tick in temperatures for Friday, as the
cooler air pushes into the forecast area. Friday could see a slight
chance for some rain, as a short wave trough glides over the area,
but due to poor moisture quality expect very little if any
precipitation from this system. Southerly winds pick up in response
to another developing surface low over the High Plains, allowing for
warmer/moister air to move into E Kansas and W Missouri. Along with
the warmer southerly flow mid level ridging will move over the area,
bringing a chance for a rather dramatic warm up for the weekend,
especially for Sunday, when temperatures will likely reach the 70+
degree mark across most of Missouri. Beyond the weekend, into next
week the pattern looks to change a bit, as several chances for
convective showers will be present. The long range pattern looks to
change to more of a troughing in the west pattern which could push
several impulses into the forecast are next week. The first chance
for rain looks possible on Monday as a strong shortwave trough moves
through, then perhaps again on Wednesday as another trough moves
through. As of now, it looks plausible that a decent fetch of
moisture will be present from the Gulf of Mexico, allowing for any
potential system to have good fuel. More details in upcoming
forecasts.
&&
.MESOSCALE DISCUSSION...
Issued at 1130 AM CDT THU MAR 27 2014
While a first glance would suggest the severe risk is marginal there
are enough parameters in place or coming together to support a
slight risk of severe thunderstorms this afternoon over most of the
CWA. While much of the region is under this slight risk threat the
best parameters are coming together southeast of a Paola to
Carrollton to Moberly line.
Latest short-range convective allowing models, HRRR and RAP,
continue to show convection initiating over eastern KS along a
pseudo dry-line around 19z. At the same time a cold front will sweep
in from the northwest and gradually overtake the dryline during the
afternoon hours. Initial individual storms are expected to quickly
form short-line segments which will evolve into a relatively narrow
but larger squall-line as the entire line of storms tracks eastward
through the CWA. However, very strong mid-level steering winds will
allow individual storms to zip northeast between 40-50 mph.
While short-range models show a nearly uni-directional vertical wind
profile there is sufficient turning between the very strong
southerly boundary layer winds gusting over 30kt and the extremely
strong southwesterly h8 winds of 50-70kt to support rotating
thunderstorms. MLCAPE values are expected to range from 500 J/kg
over northern MO to a more modest 1500 J/kg over the far southern
counties as mid 50 surface dewpoints and the h8 moist axis work into
this region.
Inspection of forecast NAM Bufr soundings reveal a low freezing
level averaging around 9K ft agl along with a strong cap in place.
Current thinking is once the cap is broken, and it will, storms with
50dBz echoes of at least 20-22K ft agl will support the potential
for large hail. Storm tops could reach 35K ft agl.
The expected squall-line is expected to exit the far eastern
counties by around 7 pm and thus end the risk of severe weather.
Summing up: individual storms initiate over far eastern KS around
19z. Individual storms form short-line segments quickly and into a
larger squall-line as the storms move through the CWA and exit the
far eastern counties by 7 pm. Individual storms will race northeast
between 40-50 mph while the line shifts east. The primary threats,
in order of risk, are damaging winds up to 70 mph, marginally
severe hail around an inch with a very low risk of isolated
tornadoes. All but far northwest MO is under a slight risk for
severe weather with the best threat of severe thunderstorms
southeast of a Paola, KS to Carrollton to Moberly line. This
includes the southeastern portion of the greater Kansas City area as
well as cities such as Butler, Warrensburg, Sedalia and Boonville.
&&
.DISCUSSION...
Issued at 308 AM CDT THU MAR 27 2014
The main concern for the short-term forecast deals with potential
severe convection this afternoon as a quick-moving upper-level
shortwave trough tracks through the area.
An intense low-level jet is streaming over the area, noted by 50 to
70 kts in the 500 to 1000 meter range, on area 88D VWP plots. A
tight pressure gradient also remains across the area and it`s
expected that as the surface low approaches, the pressure gradient
may tighten enough to get stronger sustained winds around 30 mph in
our southern zones. Even if this doesn`t happen though, as the
boundary layer begins to mix into the extremely strong winds aloft,
very strong wind gusts are expected to occur, likely approaching or
exceeding 45 mph. At the moment, this looks confined to our southern
counties, generally south of Highway 50. This area will see the
tightest pressure gradient and the best potential for deeper
mixing, so a wind advisory will be posted in this area
Strong isentropic ascent will be ongoing throughout the day and
we`ll likely see rounds of showers and storms before the main storms
associated with an advancing surface low and front develop during
the afternoon. There is a concern that stratus will persist through
the day, inhibiting full insolation and thus limiting the amount of
potential instability. But with the upper-level PV anomaly moving
over and introducing dry air aloft, some erosion in the clouds is
possible ahead of the front, especially over southern and
southwestern portions of the forecast area. This may lead to a
narrow corridor of greater instability just ahead of the front for
any storms to ingest. So CAPE values around 1000 J/kg are likely in
this more favorable prefrontal zone. Shear is ample, around 50 to
60kts of 0-6km bulk shear is expected. Shear looks to be not quite
parallel to the initiating front so storms may initially be more
discrete. The strong shear also supports rotating storms so at least
initially there will be a hail threat with the stronger storms.
Surface winds are veered significantly, really limiting helicity
values. So as the previous forecaster mentioned, the threat of
tornadoes looks low and at this point confidence remains high in
downplaying that hazard. However, the front should quickly move
eastward and overtake any discrete cells leading to a quick
transition to linear segments with the main hazard becoming damaging
winds. The entire front and associated storms should exit our
forecast area to the east by 23Z- 01Z.
Cooler temperatures are expected on Friday with light winds and
limited mixing. This should lead to cooler than normal highs for the
day with most areas in the upper 40s to middle 50s. As has been
anticipated for several days, the weekend is expected to be
fantastic with seasonal temperatures on Saturday and above normal
temperatures on Sunday. The surface ridge axis may be bisecting the
area on Saturday afternoon which would limit mixing and potential
high temperatures. But highs in the upper 50s and lower 60s still
look reasonable. For Sunday, stronger southerly flow is expected
which help temperatures climb into the 70s.
Models track another surface low and frontal boundary across the
heart of the country on Monday. The GFS and the ECMWF are further
north, taking the low through either northern Iowa or southern
Minnesota and move the front through earlier. The GEM is farther
south and slower and this difference results in the GEM having much
warmer temperatures just ahead of the front. For this time frame,
tended to favor the GFS and the ECMWF so temperatures in the 60s
look more reasonable at this point. The other aspect of this
frontal passage is the potential for another round of precipitation.
Instability looks rather weak so have just mention to just showers.
Models then develop a more robust system with access to more ample
moisture. There is actually good agreement between the GFS and the
ECMWF draping a warm front across the forecast area and developing
scattered to widespread showers and thunderstorms along it. The
likely POPs from the forecast initialization seem reasonable at this
point there should be a good chance for additional much needed
precipitation late Tuesday night and through the day Wednesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1230 PM CDT THU MAR 27 2014
MVFR clouds will great the terminals this afternoon in the environment
ahead of a cold front that will sweep through later today.
Thunderstorms are expected to go up in the vicinity of the terminals
as the front moves through during the early to mid-afternoon hours,
but confidence is a bit low for any particular storms effecting the
terminals. Winds ahead of and behind the front will be rather gusty
into the evening hours, but should subside late tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 3 PM CDT this afternoon FOR KSZ057-060.
MO...WIND ADVISORY until 3 PM CDT this afternoon FOR MOZ043>045-053-
054.
&&
$$
UPDATE...Leighton
DISCUSSION...CDB
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1230 PM CDT Thu Mar 27 2014
.MESOSCALE DISCUSSION...
Issued at 1130 AM CDT THU MAR 27 2014
While a first glance would suggest the severe risk is marginal there
are enough parameters in place or coming together to support a
slight risk of severe thunderstorms this afternoon over most of the
CWA. While much of the region is under this slight risk threat the
best parameters are coming together southeast of a Paola to
Carrollton to Moberly line.
Latest short-range convective allowing models, HRRR and RAP,
continue to show convection initiating over eastern KS along a
pseudo dry-line around 19z. At the same time a cold front will sweep
in from the northwest and gradually overtake the dryline during the
afternoon hours. Initial individual storms are expected to quickly
form short-line segments which will evolve into a relatively narrow
but larger squall-line as the entire line of storms tracks eastward
through the CWA. However, very strong mid-level steering winds will
allow individual storms to zip northeast between 40-50 mph.
While short-range models show a nearly uni-directional vertical wind
profile there is sufficient turning between the very strong
southerly boundary layer winds gusting over 30kt and the extremely
strong southwesterly h8 winds of 50-70kt to support rotating
thunderstorms. MLCAPE values are expected to range from 500 J/kg
over northern MO to a more modest 1500 J/kg over the far southern
counties as mid 50 surface dewpoints and the h8 moist axis work into
this region.
Inspection of forecast NAM Bufr soundings reveal a low freezing
level averaging around 9K ft agl along with a strong cap in place.
Current thinking is once the cap is broken, and it will, storms with
50dBz echoes of at least 20-22K ft agl will support the potential
for large hail. Storm tops could reach 35K ft agl.
The expected squall-line is expected to exit the far eastern
counties by around 7 pm and thus end the risk of severe weather.
Summing up: individual storms initiate over far eastern KS around
19z. Individual storms form short-line segments quickly and into a
larger squall-line as the storms move through the CWA and exit the
far eastern counties by 7 pm. Individual storms will race northeast
between 40-50 mph while the line shifts east. The primary threats,
in order of risk, are damaging winds up to 70 mph, marginally
severe hail around an inch with a very low risk of isolated
tornadoes. All but far northwest MO is under a slight risk for
severe weather with the best threat of severe thunderstorms
southeast of a Paola, KS to Carrollton to Moberly line. This
includes the southeastern portion of the greater Kansas City area as
well as cities such as Butler, Warrensburg, Sedalia and Boonville.
&&
.DISCUSSION...
Issued at 308 AM CDT THU MAR 27 2014
The main concern for the short-term forecast deals with potential
severe convection this afternoon as a quick-moving upper-level
shortwave trough tracks through the area.
An intense low-level jet is streaming over the area, noted by 50 to
70 kts in the 500 to 1000 meter range, on area 88D VWP plots. A
tight pressure gradient also remains across the area and it`s
expected that as the surface low approaches, the pressure gradient
may tighten enough to get stronger sustained winds around 30 mph in
our southern zones. Even if this doesn`t happen though, as the
boundary layer begins to mix into the extremely strong winds aloft,
very strong wind gusts are expected to occur, likely approaching or
exceeding 45 mph. At the moment, this looks confined to our southern
counties, generally south of Highway 50. This area will see the
tightest pressure gradient and the best potential for deeper
mixing, so a wind advisory will be posted in this area
Strong isentropic ascent will be ongoing throughout the day and
we`ll likely see rounds of showers and storms before the main storms
associated with an advancing surface low and front develop during
the afternoon. There is a concern that stratus will persist through
the day, inhibiting full insolation and thus limiting the amount of
potential instability. But with the upper-level PV anomaly moving
over and introducing dry air aloft, some erosion in the clouds is
possible ahead of the front, especially over southern and
southwestern portions of the forecast area. This may lead to a
narrow corridor of greater instability just ahead of the front for
any storms to ingest. So CAPE values around 1000 J/kg are likely in
this more favorable prefrontal zone. Shear is ample, around 50 to
60kts of 0-6km bulk shear is expected. Shear looks to be not quite
parallel to the initiating front so storms may initially be more
discrete. The strong shear also supports rotating storms so at least
initially there will be a hail threat with the stronger storms.
Surface winds are veered significantly, really limiting helicity
values. So as the previous forecaster mentioned, the threat of
tornadoes looks low and at this point confidence remains high in
downplaying that hazard. However, the front should quickly move
eastward and overtake any discrete cells leading to a quick
transition to linear segments with the main hazard becoming damaging
winds. The entire front and associated storms should exit our
forecast area to the east by 23Z- 01Z.
Cooler temperatures are expected on Friday with light winds and
limited mixing. This should lead to cooler than normal highs for the
day with most areas in the upper 40s to middle 50s. As has been
anticipated for several days, the weekend is expected to be
fantastic with seasonal temperatures on Saturday and above normal
temperatures on Sunday. The surface ridge axis may be bisecting the
area on Saturday afternoon which would limit mixing and potential
high temperatures. But highs in the upper 50s and lower 60s still
look reasonable. For Sunday, stronger southerly flow is expected
which help temperatures climb into the 70s.
Models track another surface low and frontal boundary across the
heart of the country on Monday. The GFS and the ECMWF are further
north, taking the low through either northern Iowa or southern
Minnesota and move the front through earlier. The GEM is farther
south and slower and this difference results in the GEM having much
warmer temperatures just ahead of the front. For this time frame,
tended to favor the GFS and the ECMWF so temperatures in the 60s
look more reasonable at this point. The other aspect of this
frontal passage is the potential for another round of precipitation.
Instability looks rather weak so have just mention to just showers.
Models then develop a more robust system with access to more ample
moisture. There is actually good agreement between the GFS and the
ECMWF draping a warm front across the forecast area and developing
scattered to widespread showers and thunderstorms along it. The
likely POPs from the forecast initialization seem reasonable at this
point there should be a good chance for additional much needed
precipitation late Tuesday night and through the day Wednesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1230 PM CDT THU MAR 27 2014
MVFR clouds will great the terminals this afternoon in the environment
ahead of a cold front that will sweep through later today.
Thunderstorms are expected to go up in the vicinity of the terminals
as the front moves through during the early to mid-afternoon hours,
but confidence is a bit low for any particular storms effecting the
terminals. Winds ahead of and behind the front will be rather gusty
into the evening hours, but should subside late tonight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 3 PM CDT this afternoon FOR KSZ057-060.
MO...WIND ADVISORY until 3 PM CDT this afternoon FOR MOZ043>045-053-
054.
&&
$$
DISCUSSION...CDB
AVIATION...Cutter
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1210 PM CDT Thu Mar 27 2014
...Risk for Strong to Severe Storms this Afternoon and Evening...
.MESOSCALE DISCUSSION...
Issued at 1151 AM CDT THU MAR 27 2014
Conditions will slowly destabilize this afternoon. A dry line is
currently developing near the I-35 corridor across south central
Kansas into north central Oklahoma. A cold front was moving
southeastward across north central Kansas. Strong southerly winds
are slowly moistening the low atmosphere with dewpoints already in
the lower to middle 50s across southeast Kansas. This plume of
moisture will continue to advance northeastward. The clearing line
or breaks in the clouds was currently just west of the CWA in
southeast Kansas near Chanute to Parsons southward. This clearing
line will continue to slowly move eastward.
Temperatures will slowly warm into the upper 60s to near 70 where
sun breaks through especially west of Highway 65. HRRR and RUC
show initiation of convection to occur just on our door step
across the Highway 69 corridor by 19z to 20z. The high res models
support discreet cells.
Environmental conditions include 60 knot plus bulk shear...70
knots plus low level jet. A mid level jet streak punch through
southeast Kansas into West Central Missouri noted on visible
satellite imagery. MUCAPE values approaching 1000 to 1500 J/KG.
Helicity values between 500 to 700 m2/s2.
The main threat will be strong damaging wind gusts up to 70 mph.
Large hail up to the size of half dollars will be possible. And
initially discreet supercells may develop late this afternoon for
areas west of Highway 65 with a low risk of a tornado or two
before the threat diminishes by sunset and storms become more linear
and line segments from Highway 65 eastward late this evening.
Will have a special balloon release going up by 19z and will have
another meso update with the latest weather balloon information.
&&
.SHORT TERM...(Today and Tonight)
Issued at 204 AM CDT THU MAR 27 2014
The main concern is for severe thunderstorm chances this afternoon
and this evening.
A quick moving shortwave that brought some brief/light precip to
the area has moved rapidly off to the east. In it`s wake a strong
eml/cap has begun to move advect into the area. In the near term
this will effectively limit precip chances through the morning.
Can`t rule out some light precip here and there.
An upstream shortwave now moving into the central High Plains
will shift ene into eastern Neb and KS by 18z...taking on a
slightly negative tilt as it continues ene into the Midwest
tonight. Lift from the is shortwave will weaken and then break the
cap from nw to se during the mid/late afternoon beginning shortly
before 21z. Convection should start to develop or intensify during
this time along a subtle dry line close to the east central
KS/west central MO border. A synoptic sfc cold front will be right
on it`s heels, and likely catch up to the dry line in fairly short
order by late afternoon. Sfc heating near 70 deg F in some places
along with low-mid 50s dew points in a narrow corridor along/ahead
of the dry line (and later the cold front) will yield uncapped sfc
based CAPE on the order of 500-800 J/kg (03z run of the SREF...GFS
modified soundings similar). Despite the modest instability, strong
vertical shear should compensate for the lack of instability, so
expect some supercell structures to be possible initially as storm
updrafts become robust during the mid/late afternoon. After the
cold front catches the dry line, expect storm mode to transition
to more of a line with some embedded bows. Hail with rotating
updrafts (despite the modest instability), damaging winds, and a
low end tornado risk with discrete convection early in the
convective development will continue to be mentioned in the HWO.
Expect the severe storm risk to gradually decrease in the evening
with the loss of heating. Most of the convection will move east of
the region by 06Z.
.LONG TERM...(Friday through Wednesday)
Issued at 204 AM CDT THU MAR 27 2014
Friday: Another shortwave will move into the central Plains on
Friday and develop a sfc wave along the temporarily stalled front.
Rain and some thunderstorm chances will exists again late Friday
into Friday evening as the system quickly passes. Will have have
some fairly high pops over south central MO...tapering them back
to near nil or very low values over the nw cwfa.
Saturday: High pressure and a nice day. 50s and 60s for highs.
Sunday-Monday: Sfc high pressure shifts east with gusty south winds
developing over out western counties during the afternoon.
Guidance has been consistent in moving a Pacific based shortwave
into central Rockies late in the day with developing sfc low
pressure over the High Plains. This system intensifies Sunday
night into Monday as it begins to draw some cold air south from
Canada. Limited moisture ahead of the trailing cold front will
will keep rain amounts fairly low with the frontal passage late
Sunday night into Monday.
Tuesday-Wednesday: A more active pattern may be setting up by
midweek as a substantial upper trough moves into the western U.S
and a lead shortwave supports a decent sfc low moving through or
nearby the region. Consensus guidance has fairly high pops for
Tuesday night into Wednesday.
&&
.AVIATION...(For the 18Z TAFS through 18Z Friday Afternoon)
Issued at 1151 AM CDT THU MAR 27 2014
Pilots can expect very windy conditions through this evening as a cold
front moves into the region. Frequent gusts over 30 kts can be
expected. MVFR ceilings will prevail with some breaks in the
clouds later in the afternoon. Showers and thunderstorms will
develop along and just ahead of the front as it moves across the
area from mid afternoon into early this evening. Some of these
storms could be severe. Winds will shift to the west and northwest
behind the front this evening with VFR conditions returning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WIND ADVISORY until 5 PM CDT this afternoon FOR MOZ055-056-
066>069-077>081-088>095-101>103.
KS...WIND ADVISORY until 5 PM CDT this afternoon FOR KSZ073-097-101.
&&
$$
MESOSCALE...Griffin
SHORT TERM...DSA
LONG TERM...DSA
AVIATION...Foster
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1131 AM CDT Thu Mar 27 2014
.MESOSCALE DISCUSSION...
Issued at 1130 AM CDT THU MAR 27 2014
While a first glance would suggest the severe risk is marginal there
are enough parameters in place or coming together to support a
slight risk of severe thunderstorms this afternoon over most of the
CWA. While much of the region is under this slight risk threat the
best parameters are coming together southeast of a Paola to
Carrollton to Moberly line.
Latest short-range convective allowing models, HRRR and RAP,
continue to show convection initiating over eastern KS along a
pseudo dry-line around 19z. At the same time a cold front will sweep
in from the northwest and gradually overtake the dryline during the
afternoon hours. Initial individual storms are expected to quickly
form short-line segments which will evolve into a relatively narrow
but larger squall-line as the entire line of storms tracks eastward
through the CWA. However, very strong mid-level steering winds will
allow individual storms to zip northeast between 40-50 mph.
While short-range models show a nearly uni-directional vertical wind
profile there is sufficient turning between the very strong
southerly boundary layer winds gusting over 30kt and the extremely
strong southwesterly h8 winds of 50-70kt to support rotating
thunderstorms. MLCAPE values are expected to range from 500 J/kg
over northern MO to a more modest 1500 J/kg over the far southern
counties as mid 50 surface dewpoints and the h8 moist axis work into
this region.
Inspection of forecast NAM Bufr soundings reveal a low freezing
level averaging around 9K ft agl along with a strong cap in place.
Current thinking is once the cap is broken, and it will, storms with
50dBz echoes of at least 20-22K ft agl will support the potential
for large hail. Storm tops could reach 35K ft agl.
The expected squall-line is expected to exit the far eastern
counties by around 7 pm and thus end the risk of severe weather.
Summing up: individual storms initiate over far eastern KS around
19z. Individual storms form short-line segments quickly and into a
larger squall-line as the storms move through the CWA and exit the
far eastern counties by 7 pm. Individual storms will race northeast
between 40-50 mph while the line shifts east. The primary threats,
in order of risk, are damaging winds up to 70 mph, marginally
severe hail around an inch with a very low risk of isolated
tornadoes. All but far northwest MO is under a slight risk for
severe weather with the best threat of severe thunderstorms
southeast of a Paola, KS to Carrollton to Moberly line. This
includes the southeastern portion of the greater Kansas City area as
well as cities such as Butler, Warrensburg, Sedalia and Boonville.
&&
.DISCUSSION...
Issued at 308 AM CDT THU MAR 27 2014
The main concern for the short-term forecast deals with potential
severe convection this afternoon as a quick-moving upper-level
shortwave trough tracks through the area.
An intense low-level jet is streaming over the area, noted by 50 to
70 kts in the 500 to 1000 meter range, on area 88D VWP plots. A
tight pressure gradient also remains across the area and it`s
expected that as the surface low approaches, the pressure gradient
may tighten enough to get stronger sustained winds around 30 mph in
our southern zones. Even if this doesn`t happen though, as the
boundary layer begins to mix into the extremely strong winds aloft,
very strong wind gusts are expected to occur, likely approaching or
exceeding 45 mph. At the moment, this looks confined to our southern
counties, generally south of Highway 50. This area will see the
tightest pressure gradient and the best potential for deeper
mixing, so a wind advisory will be posted in this area
Strong isentropic ascent will be ongoing throughout the day and
we`ll likely see rounds of showers and storms before the main storms
associated with an advancing surface low and front develop during
the afternoon. There is a concern that stratus will persist through
the day, inhibiting full insolation and thus limiting the amount of
potential instability. But with the upper-level PV anomaly moving
over and introducing dry air aloft, some erosion in the clouds is
possible ahead of the front, especially over southern and
southwestern portions of the forecast area. This may lead to a
narrow corridor of greater instability just ahead of the front for
any storms to ingest. So CAPE values around 1000 J/kg are likely in
this more favorable prefrontal zone. Shear is ample, around 50 to
60kts of 0-6km bulk shear is expected. Shear looks to be not quite
parallel to the initiating front so storms may initially be more
discrete. The strong shear also supports rotating storms so at least
initially there will be a hail threat with the stronger storms.
Surface winds are veered significantly, really limiting helicity
values. So as the previous forecaster mentioned, the threat of
tornadoes looks low and at this point confidence remains high in
downplaying that hazard. However, the front should quickly move
eastward and overtake any discrete cells leading to a quick
transition to linear segments with the main hazard becoming damaging
winds. The entire front and associated storms should exit our
forecast area to the east by 23Z- 01Z.
Cooler temperatures are expected on Friday with light winds and
limited mixing. This should lead to cooler than normal highs for the
day with most areas in the upper 40s to middle 50s. As has been
anticipated for several days, the weekend is expected to be
fantastic with seasonal temperatures on Saturday and above normal
temperatures on Sunday. The surface ridge axis may be bisecting the
area on Saturday afternoon which would limit mixing and potential
high temperatures. But highs in the upper 50s and lower 60s still
look reasonable. For Sunday, stronger southerly flow is expected
which help temperatures climb into the 70s.
Models track another surface low and frontal boundary across the
heart of the country on Monday. The GFS and the ECMWF are further
north, taking the low through either northern Iowa or southern
Minnesota and move the front through earlier. The GEM is farther
south and slower and this difference results in the GEM having much
warmer temperatures just ahead of the front. For this time frame,
tended to favor the GFS and the ECMWF so temperatures in the 60s
look more reasonable at this point. The other aspect of this
frontal passage is the potential for another round of precipitation.
Instability looks rather weak so have just mention to just showers.
Models then develop a more robust system with access to more ample
moisture. There is actually good agreement between the GFS and the
ECMWF draping a warm front across the forecast area and developing
scattered to widespread showers and thunderstorms along it. The
likely POPs from the forecast initialization seem reasonable at this
point there should be a good chance for additional much needed
precipitation late Tuesday night and through the day Wednesday.
&&
.AVIATION...(For the 12Z TAFS through 12Z Friday Morning)
Issued at 616 AM CDT THU MAR 27 2014
MVFR conditions are expected to persist across the area this morning
before lifting this afternoon. A very strong low level jet is flowing
over the area and the boundary layer has tried to decouple resulting
in lighter winds. With winds just above the surface flowing at 50 to
60 kts, have added mention of LLWS for a few hours this morning.
Surface winds should really start to increase just after sunrise as
the boundary layer begins to mix. This will result in winds gusting
around 40 mph through the morning and early afternoon. Scattered
showers are possible this morning but a front will approach from the
northwest this afternoon with scattered thunderstorms developing
ahead of it. This should affect the terminals during the early
afternoon hours. Winds will veer to the northwest in the wake of the
front and then will diminish late this evening and overnight.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WIND ADVISORY until 3 PM CDT this afternoon FOR KSZ057-060.
MO...WIND ADVISORY until 3 PM CDT this afternoon FOR MOZ043>045-053-
054.
&&
$$
MESOSCALE...MJ
DISCUSSION...CDB
AVIATION...CDB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1154 PM CDT Wed Mar 26 2014
.UPDATE:
Issued at 855 PM CDT Wed Mar 26 2014
Forecast looks to be in pretty good shape this evening. A broad
area of rain extends from near Springfield Missouri north to St.
Joseph and northeast into central and northeast Missouri. Expect
this area of showers to overspread our area through the evening
hours. Not sure how much rain there will be across the eastern
Ozarks along and south of I-44 after midnight, so will continue to
monitor for the next few hours and update as needed. Remainder of
the area should see widespread rain showers through the overnight
hours.
Made some changes to winds for Thursday. Winds in the going
forecast from 400 PM looked too light by 5 to 10 kts in both
sustained wind and gusts. The new wind forecast is just below
advisory criteria for much of the area. Will brief the midnight
shift on this and allow them to make the final call after all the
new 00Z guidance comes in.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 354 PM CDT Wed Mar 26 2014
Still expect that the leading edge of the showers currently over
northeast Oklahoma and southeast Kansas to continue to progress
northeastward into central Missouri early this evening, and then
move into northeast and east central Missouri by mid-late evening.
This goes along well with the latest runs of the RAP and our
localWRF which shows these showers being generated by 925-850mb
moisture convergence ahead of mid-level shortwave trough currently
western Oklahoma. These models show that this shortwave will
lift northeastward this evening and get sheared out as it lifts
through the CWA around 06Z, though low level moisture convergence
will be set up over the area through 12Z warranting high chance or
likely pops through the night.
The increase in clouds and the gradient winds staying up tonight
should keep temperatures from falling like they have the past few
nights. They may drop initially as the rain begins, but
temperatures are expected to remain above freezing with this event
because of the strong warm air advection. Went on the cooler side
of MOS for lows tonight given how low the dewpoints currently are.
Britt
.LONG TERM: (Thursday through Next Wednesday)
Issued at 354 PM CDT Wed Mar 26 2014
Ongoing showers and a few thunderstorms at daybreak on Thursday
should continue to lift northeast away from forecast area.
Otherwise, will see a break in activity til main frontal boundary
approaches region late Thursday afternoon over central MO. A few
storms may be severe late Thursday afternoon and evening with strong
low-mid level shear as a 500 mb wind max moves through the area.
The amount of instability is still in question and may be a limiting
factor for the amount and intensity of severe weather. As for high
temperatures, should be in the upper 50s to upper 60s since frontal
passage will be a bit slower than previously forecast.
Activity to taper off after midnight Thursday night as system exits
region. Not a lot of CAA behind this system, so lows will be in the
low 30s to mid 40s.
On Friday should see more precipitation develop as another shortwave
slides southeast through region on northwest flow and wave develops
along tail end of front that just moved through. So some overrunning
pcpn will develop south of forecast area and lift northeast into
forecast area by Friday evening, though best chances will be along
and south of I-70. As for precipitation type, it should be mostly in
the form of rain as colder air is slower to filter in. Could see
some rain mixed with snow after 06z Saturday for northern portions
of forecast area. Precipitation to exit region by daybreak Saturday.
Highs on Friday will be a bit cooler, in the low 50s to low 60s.
Lows Friday night will be in the low 30s far north to around 40 far
south.
On Saturday weak ridging builds in and skies clear out. Highs will
only be in the 50s.
Beyond that ridge moves off to the east on Sunday allowing warmer
weather to return. Highs on Sunday will be in the 60s. Then next in
a series of weather systems to approach the area late Sunday night
through Monday. Most of area has silent slight chance pops with low
chance pops along and east of Mississippi River on Monday. Highs on
Monday will be in the upper 50s to mid 60s. Then dry weather returns
to region Monday night through Tuesday before next system moves in.
This system is a bit stronger with better low level moisture. Rain
to begin moving in Tuesday night and persist through Wednesday.
Highs will be in the low 50s to low 60s Tuesday and Wednesday.
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Thursday Night)
Issued at 1150 PM CDT Wed Mar 26 2014
Broad area of showers associated with lead shortwave now covers
much of the CWA. Expect this activity to taper off west of the
Mississippi River in the 06-09z time frame as shortwave continues
to push northeast. However, also anticipate some redevelopment of
showers in the wake of the shortwave energy as fairly robust WAA
is forecast to persist over the region. Still not seeing any
extremely low ceilings over SW MO, W AR, or E OK, so have
maintained cigs in the 3-6 kft range. Also, no change from earlier
thinking regarding low level wind shear potential, and it remains
in the forecast until mixing commences Thursday morning.
A quick peek at the 00z data supports earlier thinking that there
may be a fairly pronounced dry period on Thursday as a sizeable
cap is forecast to develop once the early morning elevated showers
exit the area. Don`t have a good feel yet for exact location of
storm initition on Thursday afternoon, but like the scenario of discrete
cells over western MO morphing into a line of convection as storms
work into eastern Missouri during the evening, and have attempted
to reflect this type of coverage in the way tsra is handled...with
vcnty at COU, and tempo at UIN and STL metro sites. Will leave the
more specific details of this potentially strong/severe convection
to later shifts.
Specifics for KSTL: Showers with VFR vsbys and cigs of 4-6kft
expected into the predawn hours, with low level wind shear
potential late tonight and into early Thursday due to strong low
level jet of almost 50kts. Wind shear potential will diminish by
mid morning with increase of diurnal heating/increased mixing,
with a corresponding jump in surface winds as gusts of 30-35 kts
are expected. As mentioned in primary aviation discussion, timing
of tomorrow afternoon/evening convection still not totally clear,
but model consensus seems to suggest a line of convection will be
rolling through the area in the evening hours, with at least MVFR
cigs/vsbys. Given the intense wind fields strong winds will be a
real possibility with this line of convection, but will leave this
fine tuning to later shifts as exact trends become a bit more clear.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
132 PM CDT THU MAR 27 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
MID/UPPER LEVEL SHORTWAVE TROUGH CONTINUES TO MOVE NORTHEAST ACROSS
NORTHEAST COLORADO AND INTO WESTERN NEBRASKA. AHEAD OF IT...A SFC
COLD FRONT EXTENDS FROM LOW PRESSURE OVER NORTHEAST COLORADO TO
ANOTHER AREA OF LOW PRESSURE OVER EASTERN SOUTH DAKOTA. THIS
BOUNDARY WILL CONTINUE TO SLOWLY SLIDE SOUTHEAST THIS MORNING
ENTERING OUR FAR NORTHWEST COUNTIES BY 12Z. THE LATEST FEW RUNS OF
THE HRRR MODEL SEEM TO HAVE A PRETTY GOOD HANDLE ON THE CURRENT
SITUATION AND HAVE FOLLOWED THE NEAR TERM FORECAST FAIRLY CLOSE TO
THIS. THIS DOES BRING THE SYSTEM THROUGH A BIT SLOWER THAN SOME OF
THE LARGER SCALE MODELS...AS WELL AS THE LATEST RAP...SO HAVE
ADJUSTED THE FORECAST ACCORDINGLY. LOW CLOUDS...FOG AND AREAS OF
DRIZZLE HAVE MOVED OVER THE FORECAST AREA EARLY THIS MORNING AHEAD
OF THE BOUNDARY. A FEW LEAD PIECES OF ENERGY MAY HELP PRODUCE AND
SPREAD SOME AREAS OF LIGHT MEASURABLE PCPN NORTHEAST THIS MORNING
SO SCATTERED SHOWERS CANNOT BE RULED OUT. UNTIL THE BETTER
FORCING MOVES INTO THE AREA ASSOCIATED WITH THE FRONTAL CIRCULATION
AND/OR THE UPPER SHORTWAVE TROUGH...EXPECT THE FOG/DRIZZLE
CONDITIONS TO CONTINUE THROUGH MID MORNING.
BEHIND THE BOUNDARY IN OUR FAR NORTH...ANY FALLING PCPN SHOULD MIX
WITH AND EVENTUALLY CHANGE OVER TO SNOW ESPECIALLY TOWARD 18Z. WE
COULD SEE AN INCH OR TWO OF ACCUMULATION ALONG THE SOUTH DAKOTA
BORDER WITH JUST A TRACE EXPECTED TO THE SOUTH. DUE TO THE SLOWER
TIMING OF THE PCPN...IT APPEARS AS THOUGH THE COLD AIR WILL HAVE
ENOUGH TIME TO SETTLE SOUTH AND PRODUCE AN INCH OR TWO.
PCPN SHOULD MOVE EAST AND OUT OF THE AREA BY LATER THIS AFTERNOON.
GUSTY NORTHWEST WINDS AND COLD AIR ADVECTION WILL LEAD TO A
BLUSTERY DAY BEHIND THE FRONT. SFC HIGH PRESSURE WILL BUILD IN
OVERNIGHT AS WEAK UPPER LEVEL RIDGING MOVES OVERHEAD. HAVE LOWERED
TEMPERATURES INTO THE UPPER TEENS IN THE NORTH WITH CLEARING SKIES
AND A BIT OF SNOW COVER.
ANOTHER SHORTWAVE TROUGH WILL MOVE INTO THE REGION ON FRIDAY. THIS
WILL BRING A SMALL CHANCE OF A RAIN/SNOW MIX TO PORTIONS OF THE
WESTERN AND NORTHERN CWA DURING THE DAYTIME HOURS.
UPPER/MID LEVEL RIDGING BUILDS OVER THE NATIONS MID SECTION ON
SATURDAY ALLOWING STRONG WARM AIR ADVECTION OVER THE AREA. SOUTHERLY
WINDS SHOULD PUSH HIGHS ON SATURDAY INTO THE 60S AND INTO THE 70S ON
SUNDAY. AS HAS BEEN THE CASE IN THE RECENT PAST...FIRE WEATHER
ISSUES WILL BE THE MAIN CONCERN OVER THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
UPPER/MID LEVEL FLOW BECOMES SOUTHWESTERLY ON SUNDAY AS AN
APPROACHING WESTERN TROUGH DIGS ACROSS THE WESTERN CONUS. THE
ASSOCIATE LEE SIDE SFC LOW IS FORECAST TO DRIFT EAST ACROSS NEBRASKA
SUNDAY NIGHT. MUCH OF THE FORECAST AREA LOOKS TO GET DRY SLOTTED
WITH LITTLE CHANCE OF ACCUMULATING PRECIPITATION. THE AREA THAT MAY
HAVE THE BEST CHANCE WILL BE ACROSS OUR EXTREME NORTH AS THE UPPER
SHORTWAVE MOVES ACROSS NORTHEAST NEBRASKA AND INTO NORTHERN IOWA ON
MONDAY. MUCH COLDER AIR SINKS SOUTH ALONG WITH FAIRLY STRONG
NORTHWEST WINDS WHICH COULD PRODUCE A QUITE BLUSTERY DAY WITH
FALLING DAYTIME TEMPERATURES MONDAY. SFC HIGH PRESSURE BUILDS IN
OVERNIGHT MONDAY INTO TUESDAY...WHICH WILL DROP LOWS INTO THE 2OS.
A POTENT SYSTEM WILL AFFECT THE REGION BEGINNING AS EARLY AS TUESDAY
AS RETURN FLOW SETS UP AROUND THE DEPARTING HIGH PRESSURE. A
LARGE/BROAD UPPER TROUGH IS FORECAST TO DIG ACROSS THE WESTERN THIRD
OF THE CONUS WITH LEAD SHORTWAVE ENERGY EJECTING OUT AHEAD OF IT.
THIS DYNAMIC MIDWEEK SYSTEM LOOKS TO BRING A GOOD AMOUNT OF MOISTURE
SOMEWHERE INTO THE CENTRAL PLAINS...WITH THE DETAILS IN TIMING
AND POSITIONING YET TO BE RESOLVED.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 125 PM CDT THU MAR 27 2014
PERIOD STARTS OFF RATHER MESSY WITH IFR CIGS AND MVFR VSBYS
EXPECTED THROUGH ABOUT 00Z. CONDITIONS IMPROVE AFTER THAT AS
SURFACE SYSTEM LIFTS TOWARD THE GREAT LAKES REGION AND PRECIP
ENDS. HIGH PRESSURE THEN BUILDS INTO THE REGION WITH A PERIOD
OF VFR CONDITIONS EXPECTED BEFORE A RETURN OF MVFR CIGS AFTER
12Z AS ANOTHER SURFACE WAVE TRACKS INTO THE REGION.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS HASTINGS NE
102 PM CDT THU MAR 27 2014
.UPDATE...
ISSUED AT 1247 PM CDT THU MAR 27 2014
ISSUED AN UPDATE EARLIER TO ACCOUNT FOR DETERIORATING CONDITIONS
IN THE NORTHERN CWA AS A SNOW SQUALL PASSES THROUGH. THERE WAS
SOME FREEZING RAIN PRECEDING THE SNOW UP NEAR ORD...AND PERHAPS
SOME SLEET IN GREELEY AND HOWARD COUNTIES. SOME SLEET WAS REPORTED
IN GRAND ISLAND EARLIER. THE HRRR SEEMS TO BE GRABBING ON TO THIS
THE BEST AND INDICATES THINGS WILL REALLY WIND DOWN BY 2 PM OR SO.
ISSUED A VERY SHORT TERM WINTER WEATHER ADVISORY FOR FOUR OF OUR
NORTHERN COUNTIES WITH LOW VISIBILITY WITH SNOW AND BLOWING
SNOW...AND ALSO THE PRECEDING FREEZING RAIN BEING REPORTED. SNOW
AMOUNTS SHOULD NOT AMOUNT TO MUCH MORE THAN AN INCH FOR MOST
AREAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT THU MAR 27 2014
...A COMPLICATED SCENARIO TODAY WITH MULTIPLE FINE-TUNING
ADJUSTMENTS PROBABLY REQUIRED AS THE SITUATION DEVELOPS...
ALOFT: THE FLOW HAS TRANSITIONED TO QUASI-ZONAL. TWO LOW-
AMPLITUDE SHORTWAVE TROFS WILL AFFECT THE FCST AREA THRU TONIGHT.
THE FIRST IS MOVING THRU RIGHT NOW WITH A 90 KT JET STREAK. THE
SECOND IS CURRENTLY OVER THE PACIFIC NW. THIS TROF WILL CROSS THE
NRN ROCKIES AND APPROACH THE PLAINS BY DAYBREAK TOMORROW. IN
BETWEEN A SHORTWAVE RIDGE MOVES THRU TONIGHT.
SURFACE: A COLD FRONT WAS OVER THE SANDHILLS EXTENDING DOWN TO A
991 MB LOW JUST SW OF HOLDREGE. THE FRONT WILL SAG ACROSS THE
FCST AREA TODAY AS THIS LOW HEADS NE...CROSSING IA TODAY AND
MOVING INTO THE GREAT LAKES TONIGHT. CANADIAN HIGH PRES WILL NOSE
INTO THE REGION LATE TODAY AND TONIGHT AS THE LOW DEPARTS.
NOW: A NW-SE BAND OF SHWRS WITH OCCASIONAL EMBEDDED THUNDER HAS
DEVELOPED AS EXPECTED AND IT WILL EXIT INTO ERN NEB BEFORE
SUNRISE...LEAVING AREAS OF DRIZZLE AND PATCHY FOG. VISIBILITY AT A
COUPLE LOCATIONS HAVE BRIEFLY DROPPED TO 1/2 SM AND EXPECT
VISIBILITIES TO DECAY FURTHER AS WINDS HAVE DROPPED OFF
SUBSTANTIALLY JUST AHEAD OF THE FRONT.
PRECIP AMOUNTS OVERNIGHT HAVE BEEN MINIMAL.
THE LOW IS ATTEMPTING TO CLOSE OFF A MID-LVL CIRCULATION AND A
COMMAHEAD FEATURE. THIS EVOLUTION IS ON-GOING PER SATELLITE/
RADAR. THE DEFORMATION BAND HAS FORMED W OF THE 00Z MODELS. SO IN
THE LAST HOUR...SOME SUBSTANTIAL CHANGES NEEDED TO BE MADE BEFORE
SENDING THE FCST. HAD TO DEVIATE FROM MOST OF THE 00Z MODELS...
DELAYING ITS APPROACH INTO S-CNTRL NEB. THE 06Z HI-RES RAP HAS A
MUCH BETTER HANDLE ON THE RADAR DEPICTION AND IT WAS FOLLOWED.
POPS WERE CHANGED CLOSER TO THE 03Z SREF WITH SOME INPUT FROM THE
06Z NAM.
SEVERAL SCENARIOS COULD PLAY OUT TODAY. THE 06Z NAM SUGGESTS THE
SRN END OF THE DEFORMATION ZONE PRECIP COULD FALL APART AND/OR
HEAD MORE NE THAN E...MEANING THAT AREAS S OF I-80 MAY NOT SEE
MUCH. THE OTHER POSSIBILITY IS 1-2" OF SNOW ON GRASSY AREAS N OF
I-80. THAT IS ON THE TABLE...BUT THE NARROW NATURE OF THE BAND
SHOULD LIMIT ACCUM...AND IT WOULD HAVE TO COME DOWN HEAVY GIVEN
THE RELATIVELY WARM GROUND. NDOR ROAD TEMPS ARE IN THE 40S. SO AM
NOT EXPECTING ANY PROBLEMS ON THE ROADS IF THIS OCCURS.
THE DELAY ALSO WILL AFFECT TEMPS AND ALLOW FOR INSOLATION TO
COUNTER THE COLD AIR ADVECTION. THIS MAKES P-TYPE QUESTIONABLE.
USED THE 03Z SREF PROBABILITIES FOR SUB-FRZG 850 MB TEMPS AND
1000-850 MB THICKNESSES TO AID IN FORECASTING THE TRANSITION TO
SNOW.
THIS IS NOT AN EASY FCST AND THE SITUATION IS EVOLVING AS THE LOW
ORGANIZES IN THE LEFT EXIT REGION OF THE UPPER JET. MULTIPLE
ADJUSTMENTS TO THE FCST WILL PROBABLY BE NECESSARY THRU NOON AS
THE SITUATION BECOMES MORE CLEAR.
WIND: A SURGE OF COLD AIR ADVECTION /CAA/ AND RAPID PRES RISES
WILL RESULT IN ANOTHER DAY OF STRONG WINDS. WINDS WILL BE MOST
INTENSE IMMEDIATELY BEHIND THE FRONT AND SOME LOCATIONS COULD
FLIRT WITH ADVISORY CRITERIA /SUSTAINED 30-39 MPH OR G45 MPH/.
HOWEVER... CURRENTLY BELIEVE THE BRIEF DURATION OF THE STRONGEST
SUSTAINED WINDS/ GUSTS DOES NOT WARRANT ISSUANCE OF AN ADVISORY.
ANY LOW-END ADVISORY WINDS COULD BE HANDLED WITH A SPECIAL WX
STATEMENT BY THE DAY SHIFT.
FCST WINDS ARE AN EVEN BLEND OF THE 12Z AND 00Z HI-RES GEM.
HIGHS TODAY ARE BASED ON THE 05Z RAP WITH THE 06Z NAM 2M TEMPS
USED FOR THE HOURLIES. THE COLUMN WILL TURN COLDER...AND THE
PRECIP BAND WILL PROBABLY RESULT IN A TEMPORARY DROP IN TEMPS.
OVERALL EXPECT DRIZZLE AND FOG TO END BY LATE MORNING. CLOUDY
SKIES REMAIN...BUT DECREASING CLOUDS WILL OCCUR OVER N-CNTRL KS.
THEN WE WATCH FOR THE PRECIP BAND TO MOVE ACROSS MOST OF S-CNTRL
NEB. GRADUAL CLEARING IS EXPECTED FROM W-E THIS AFTERNOON. AREAS E
OF HWY 281 MAY NOT CLEAR OUT UNTIL EARLY EVENING.
TONIGHT: CLEARING BUT AS QUICKLY AS CLOUDS CLEAR THEY WILL
INCREASE FROM THE W. PATCHY R/S WILL BEGIN TO MOVE IN AFTER
MIDNIGHT. POPS WILL PROBABLY NEED TO BE RAISED ON THE DAY SHIFT.
THE GREATEST CHANCE WILL BE W OF HWY 281. PRECIP AMOUNTS WILL BE
LIGHT IN THE PREDAWN HOURS. 03Z SREF PROBABILITIES FOR .01" IS
ONLY 50%.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT THU MAR 27 2014
A FAIRLY PROGRESSIVE AND MAINLY ZONAL FLOW PATTERN WILL PERSIST
ACROSS THE CENTRAL PLAIN THROUGH MUCH OF THE EXTENDED PERIODS...
WITH BRIEF RIDGING OVER THE UPCOMING WEEKEND EXPECTED TO RESULT IN
SOME OF THE NICEST WEATHER SO FAR THIS SPRING.
STARTING OFF FRIDAY...EXPECT A MID LEVEL DISTURBANCE CROSSING THE
ROCKIES TO EMERGE INTO THE PLAINS...BRINGING THE CHANCE FOR SOME
LIGHT RAIN OR SNOW TO MUCH OF THE LOCAL AREA DURING THE DAYTIME
HOURS ON FRIDAY. WITH MODEL SOUNDINGS INDICATING THAT ANY
PRECIPITATION THAT DOES DEVELOP WILL LIKELY BE SNOW ACROSS SOUTH
CENTRAL NEBRASKA BEFORE NOON FRIDAY...WENT AHEAD AND CHANGED THE
PRECIP TYPE FOR THE MORNING HOURS NORTH OF HIGHWAY 6 TO LIGHT
SNOW...WITH LITTLE TO NO OVERALL SNOWFALL ACCUMULATION EXPECTED.
THAT SAID...WITH THE COOLER AIRMASS IN PLACE...EXPECT TEMPERATURES
TO STRUGGLE TO CLIMB INTO THE MID 40S ACROSS OUR NORTH...AND INTO
THE MID 50S ACROSS NORTH CENTRAL KANSAS BY LATE AFTERNOON...WHICH
IS ABOUT 10 DEGREES BELOW NORMAL FOR LATE MARCH.
BEHIND FRIDAYS DISTURBANCE...EXPECT AN UPPER LEVEL RIDGE ACROSS
THE INTERMOUNTAIN WEST TO TRANSITION EASTWARD...RESULTING IN
INCREASING HEIGHTS ALOFT AND WARMER TEMPERATURES FOR THE UPCOMING
WEEKEND. WHILE WINDS WILL INCREASE OUT OF THE SOUTH BOTH
DAYS...WINDS WILL GENERALLY REMAIN IN THE 10 TO 20 MPH RANGE OVER
THE UPCOMING WEEKEND...WHICH IS NOT TOO BAD COMPARED TO THE STRONG
WINDS OF LATE. OTHERWISE...THE UPPER LEVEL RIDGE THAT WILL BE
RESPONSIBLE FOR THE GENERALLY NICE WEEKEND WEATHER WILL BE QUICK
TO TRANSITION EASTWARD BY SUNDAY NIGHT AS YET ANOTHER UPPER LEVEL
DISTURBANCE CROSSES THE ROCKIES IN THE PROGRESSIVE FLOW...BRINGING
A SMALL CHANCE FOR SOME LIGHT RAINFALL MAINLY ACROSS OUR NORTH
SUNDAY NIGHT THROUGH MONDAY. THIS DISTURBANCE WILL ALSO HELP USHER
IN A WEAK COLD FRONT ACROSS THE REGION...WHICH IS EXPECTED TO DROP
TEMPERATURES BACK TO NEAR SEASONAL NORMS FOR THE REMAINDER OF THE
EXTENDED PERIODS.
THE ONLY OTHER SIGNIFICANT CHANGE TO THE EXTENDED FORECAST THIS
MORNING WAS TO INTRODUCE THE CHANCE FOR SOME ISOLATED
THUNDERSTORMS TUESDAY NIGHT THROUGH EARLY WEDNESDAY MORNING AS
SOME WEAK INSTABILITY WORKS ITS WAY NORTH ACROSS THE LOCAL AREA.
AT THIS TIME...KEPT THE MENTION OF THUNDER SOUTH OF HIGHWAY 6 AND
DO NO ANTICIPATE ANY SEVERE WEATHER AS INSTABILITY REMAINS FAIRLY
WEAK...ON THE ORDER OF ONLY A COUPLE HUNDRED JOULES NEAR THE NE/KS
STATE LINES. WHILE THERE IS SOME DISAGREEMENT AMONGST THE
MODELS...COULD SEE SOME BENEFICIAL RAINFALL WITH THIS
DISTURBANCE...BUT KEPT POPS BELOW 60 PERCENT FOR THE TIME BEING
DUE TO UNCERTAINTY IN LOCATION AND TIMING OF POTENTIAL RAINFALL.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1247 PM CDT THU MAR 27 2014
WIND WILL BE THE BIGGEST ISSUE TODAY BEHIND A STRONG COLD FRONT.
SOME SNOW AND BLOWING SNOW IS EXPECTED FOR THE NEXT FEW
HOURS...BUT SHOULD WIND DOWN AS THE FRONT CONTINUES TO MOVE
FARTHER TO THE EAST. JUST TO THE NORTH...A SNOW SQUALL IS MOVING
TO THE EAST...BUT THE TERMINAL SHOULD BE JUST FAR ENOUGH SOUTH TO
AVOID THE LIFR VISIBILITY THAT IS BEING EXPERIENCED JUST TO THE
NORTH IN GREELEY...VALLEY...HOWARD...AND SHERMAN COUNTIES. WIND
WILL DRAMATICALLY DIMINISH AFTER 01Z WITH CEILINGS CONTINUING TO
GET HIGHER...WITH VFR CONDITIONS EXPECTED FOR MUCH OF TONIGHT.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CDT THIS AFTERNOON FOR NEZ039-
040-046-047.
KS...NONE.
&&
$$
UPDATE...HEINLEIN
SHORT TERM...HALBLAUB
LONG TERM...SAR
AVIATION...HEINLEIN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
615 AM CDT THU MAR 27 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
MID/UPPER LEVEL SHORTWAVE TROUGH CONTINUES TO MOVE NORTHEAST ACROSS
NORTHEAST COLORADO AND INTO WESTERN NEBRASKA. AHEAD OF IT...A SFC
COLD FRONT EXTENDS FROM LOW PRESSURE OVER NORTHEAST COLORADO TO
ANOTHER AREA OF LOW PRESSURE OVER EASTERN SOUTH DAKOTA. THIS
BOUNDARY WILL CONTINUE TO SLOWLY SLIDE SOUTHEAST THIS MORNING
ENTERING OUR FAR NORTHWEST COUNTIES BY 12Z. THE LATEST FEW RUNS OF
THE HRRR MODEL SEEM TO HAVE A PRETTY GOOD HANDLE ON THE CURRENT
SITUATION AND HAVE FOLLOWED THE NEAR TERM FORECAST FAIRLY CLOSE TO
THIS. THIS DOES BRING THE SYSTEM THROUGH A BIT SLOWER THAN SOME OF
THE LARGER SCALE MODELS...AS WELL AS THE LATEST RAP...SO HAVE
ADJUSTED THE FORECAST ACCORDINGLY. LOW CLOUDS...FOG AND AREAS OF
DRIZZLE HAVE MOVED OVER THE FORECAST AREA EARLY THIS MORNING AHEAD
OF THE BOUNDARY. A FEW LEAD PIECES OF ENERGY MAY HELP PRODUCE AND
SPREAD SOME AREAS OF LIGHT MEASURABLE PCPN NORTHEAST THIS MORNING
SO SCATTERED SHOWERS CANNOT BE RULED OUT. UNTIL THE BETTER
FORCING MOVES INTO THE AREA ASSOCIATED WITH THE FRONTAL CIRCULATION
AND/OR THE UPPER SHORTWAVE TROUGH...EXPECT THE FOG/DRIZZLE
CONDITIONS TO CONTINUE THROUGH MID MORNING.
BEHIND THE BOUNDARY IN OUR FAR NORTH...ANY FALLING PCPN SHOULD MIX
WITH AND EVENTUALLY CHANGE OVER TO SNOW ESPECIALLY TOWARD 18Z. WE
COULD SEE AN INCH OR TWO OF ACCUMULATION ALONG THE SOUTH DAKOTA
BORDER WITH JUST A TRACE EXPECTED TO THE SOUTH. DUE TO THE SLOWER
TIMING OF THE PCPN...IT APPEARS AS THOUGH THE COLD AIR WILL HAVE
ENOUGH TIME TO SETTLE SOUTH AND PRODUCE AN INCH OR TWO.
PCPN SHOULD MOVE EAST AND OUT OF THE AREA BY LATER THIS AFTERNOON.
GUSTY NORTHWEST WINDS AND COLD AIR ADVECTION WILL LEAD TO A
BLUSTERY DAY BEHIND THE FRONT. SFC HIGH PRESSURE WILL BUILD IN
OVERNIGHT AS WEAK UPPER LEVEL RIDGING MOVES OVERHEAD. HAVE LOWERED
TEMPERATURES INTO THE UPPER TEENS IN THE NORTH WITH CLEARING SKIES
AND A BIT OF SNOW COVER.
ANOTHER SHORTWAVE TROUGH WILL MOVE INTO THE REGION ON FRIDAY. THIS
WILL BRING A SMALL CHANCE OF A RAIN/SNOW MIX TO PORTIONS OF THE
WESTERN AND NORTHERN CWA DURING THE DAYTIME HOURS.
UPPER/MID LEVEL RIDGING BUILDS OVER THE NATIONS MID SECTION ON
SATURDAY ALLOWING STRONG WARM AIR ADVECTION OVER THE AREA. SOUTHERLY
WINDS SHOULD PUSH HIGHS ON SATURDAY INTO THE 60S AND INTO THE 70S ON
SUNDAY. AS HAS BEEN THE CASE IN THE RECENT PAST...FIRE WEATHER
ISSUES WILL BE THE MAIN CONCERN OVER THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
UPPER/MID LEVEL FLOW BECOMES SOUTHWESTERLY ON SUNDAY AS AN
APPROACHING WESTERN TROUGH DIGS ACROSS THE WESTERN CONUS. THE
ASSOCIATE LEE SIDE SFC LOW IS FORECAST TO DRIFT EAST ACROSS NEBRASKA
SUNDAY NIGHT. MUCH OF THE FORECAST AREA LOOKS TO GET DRY SLOTTED
WITH LITTLE CHANCE OF ACCUMULATING PRECIPITATION. THE AREA THAT MAY
HAVE THE BEST CHANCE WILL BE ACROSS OUR EXTREME NORTH AS THE UPPER
SHORTWAVE MOVES ACROSS NORTHEAST NEBRASKA AND INTO NORTHERN IOWA ON
MONDAY. MUCH COLDER AIR SINKS SOUTH ALONG WITH FAIRLY STRONG
NORTHWEST WINDS WHICH COULD PRODUCE A QUITE BLUSTERY DAY WITH
FALLING DAYTIME TEMPERATURES MONDAY. SFC HIGH PRESSURE BUILDS IN
OVERNIGHT MONDAY INTO TUESDAY...WHICH WILL DROP LOWS INTO THE 2OS.
A POTENT SYSTEM WILL AFFECT THE REGION BEGINNING AS EARLY AS TUESDAY
AS RETURN FLOW SETS UP AROUND THE DEPARTING HIGH PRESSURE. A
LARGE/BROAD UPPER TROUGH IS FORECAST TO DIG ACROSS THE WESTERN THIRD
OF THE CONUS WITH LEAD SHORTWAVE ENERGY EJECTING OUT AHEAD OF IT.
THIS DYNAMIC MIDWEEK SYSTEM LOOKS TO BRING A GOOD AMOUNT OF MOISTURE
SOMEWHERE INTO THE CENTRAL PLAINS...WITH THE DETAILS IN TIMING
AND POSITIONING YET TO BE RESOLVED.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 615 AM CDT THU MAR 27 2014
IFR CONDITIONS WILL CONTINUE MUCH OF THE MORNING WITH FOG AND LGT
PCPN. AREA OF -TSRA TRACKED MAINLY BETWEEN KOMA AND KOFK AND THAT
MAY BE ALL OF THE THUNDER WE SEE TODAY. WINDS WILL SHIFT TO THE
NORTH OR NORTHWEST AS SURFACE LOW CONTINUE TO TRACK TOWARD WESTERN
IOWA AND WILL BECOME GUSTY. EXPECT CLOUDS AND WINDS TO DECREASE
THIS EVENING WITH A TREND TOWARD VFR AFTER 00Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS HASTINGS NE
413 AM CDT THU MAR 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 348 AM CDT THU MAR 27 2014
...A COMPLICATED SCENARIO TODAY WITH MULTIPLE FINE-TUNING
ADJUSTMENTS PROBABLY REQUIRED AS THE SITUATION DEVELOPS...
ALOFT: THE FLOW HAS TRANSITIONED TO QUASI-ZONAL. TWO LOW-
AMPLITUDE SHORTWAVE TROFS WILL AFFECT THE FCST AREA THRU TONIGHT.
THE FIRST IS MOVING THRU RIGHT NOW WITH A 90 KT JET STREAK. THE
SECOND IS CURRENTLY OVER THE PACIFIC NW. THIS TROF WILL CROSS THE
NRN ROCKIES AND APPROACH THE PLAINS BY DAYBREAK TOMORROW. IN
BETWEEN A SHORTWAVE RIDGE MOVES THRU TONIGHT.
SURFACE: A COLD FRONT WAS OVER THE SANDHILLS EXTENDING DOWN TO A
991 MB LOW JUST SW OF HOLDREGE. THE FRONT WILL SAG ACROSS THE
FCST AREA TODAY AS THIS LOW HEADS NE...CROSSING IA TODAY AND
MOVING INTO THE GREAT LAKES TONIGHT. CANADIAN HIGH PRES WILL NOSE
INTO THE REGION LATE TODAY AND TONIGHT AS THE LOW DEPARTS.
NOW: A NW-SE BAND OF SHWRS WITH OCCASIONAL EMBEDDED THUNDER HAS
DEVELOPED AS EXPECTED AND IT WILL EXIT INTO ERN NEB BEFORE
SUNRISE...LEAVING AREAS OF DRIZZLE AND PATCHY FOG. VISIBILITY AT A
COUPLE LOCATIONS HAVE BRIEFLY DROPPED TO 1/2 SM AND EXPECT
VISIBILITIES TO DECAY FURTHER AS WINDS HAVE DROPPED OFF
SUBSTANTIALLY JUST AHEAD OF THE FRONT.
PRECIP AMOUNTS OVERNIGHT HAVE BEEN MINIMAL.
THE LOW IS ATTEMPTING TO CLOSE OFF A MID-LVL CIRCULATION AND A
COMMAHEAD FEATURE. THIS EVOLUTION IS ON-GOING PER SATELLITE/
RADAR. THE DEFORMATION BAND HAS FORMED W OF THE 00Z MODELS. SO IN
THE LAST HOUR...SOME SUBSTANTIAL CHANGES NEEDED TO BE MADE BEFORE
SENDING THE FCST. HAD TO DEVIATE FROM MOST OF THE 00Z MODELS...
DELAYING ITS APPROACH INTO S-CNTRL NEB. THE 06Z HI-RES RAP HAS A
MUCH BETTER HANDLE ON THE RADAR DEPICTION AND IT WAS FOLLOWED.
POPS WERE CHANGED CLOSER TO THE 03Z SREF WITH SOME INPUT FROM THE
06Z NAM.
SEVERAL SCENARIOS COULD PLAY OUT TODAY. THE 06Z NAM SUGGESTS THE
SRN END OF THE DEFORMATION ZONE PRECIP COULD FALL APART AND/OR
HEAD MORE NE THAN E...MEANING THAT AREAS S OF I-80 MAY NOT SEE
MUCH. THE OTHER POSSIBILITY IS 1-2" OF SNOW ON GRASSY AREAS N OF
I-80. THAT IS ON THE TABLE...BUT THE NARROW NATURE OF THE BAND
SHOULD LIMIT ACCUM...AND IT WOULD HAVE TO COME DOWN HEAVY GIVEN
THE RELATIVELY WARM GROUND. NDOR ROAD TEMPS ARE IN THE 40S. SO AM
NOT EXPECTING ANY PROBLEMS ON THE ROADS IF THIS OCCURS.
THE DELAY ALSO WILL AFFECT TEMPS AND ALLOW FOR INSOLATION TO
COUNTER THE COLD AIR ADVECTION. THIS MAKES P-TYPE QUESTIONABLE.
USED THE 03Z SREF PROBABILITIES FOR SUB-FRZG 850 MB TEMPS AND
1000-850 MB THICKNESSES TO AID IN FORECASTING THE TRANSITION TO
SNOW.
THIS IS NOT AN EASY FCST AND THE SITUATION IS EVOLVING AS THE LOW
ORGANIZES IN THE LEFT EXIT REGION OF THE UPPER JET. MULTIPLE
ADJUSTMENTS TO THE FCST WILL PROBABLY BE NECESSARY THRU NOON AS
THE SITUATION BECOMES MORE CLEAR.
WIND: A SURGE OF COLD AIR ADVECTION /CAA/ AND RAPID PRES RISES
WILL RESULT IN ANOTHER DAY OF STRONG WINDS. WINDS WILL BE MOST
INTENSE IMMEDIATELY BEHIND THE FRONT AND SOME LOCATIONS COULD
FLIRT WITH ADVISORY CRITERIA /SUSTAINED 30-39 MPH OR G45 MPH/.
HOWEVER... CURRENTLY BELIEVE THE BRIEF DURATION OF THE STRONGEST
SUSTAINED WINDS/ GUSTS DOES NOT WARRANT ISSUANCE OF AN ADVISORY.
ANY LOW-END ADVISORY WINDS COULD BE HANDLED WITH A SPECIAL WX
STATEMENT BY THE DAY SHIFT.
FCST WINDS ARE AN EVEN BLEND OF THE 12Z AND 00Z HI-RES GEM.
HIGHS TODAY ARE BASED ON THE 05Z RAP WITH THE 06Z NAM 2M TEMPS
USED FOR THE HOURLIES. THE COLUMN WILL TURN COLDER...AND THE
PRECIP BAND WILL PROBABLY RESULT IN A TEMPORARY DROP IN TEMPS.
OVERALL EXPECT DRIZZLE AND FOG TO END BY LATE MORNING. CLOUDY
SKIES REMAIN...BUT DECREASING CLOUDS WILL OCCUR OVER N-CNTRL KS.
THEN WE WATCH FOR THE PRECIP BAND TO MOVE ACROSS MOST OF S-CNTRL
NEB. GRADUAL CLEARING IS EXPECTED FROM W-E THIS AFTERNOON. AREAS E
OF HWY 281 MAY NOT CLEAR OUT UNTIL EARLY EVENING.
TONIGHT: CLEARING BUT AS QUICKLY AS CLOUDS CLEAR THEY WILL
INCREASE FROM THE W. PATCHY R/S WILL BEGIN TO MOVE IN AFTER
MIDNIGHT. POPS WILL PROBABLY NEED TO BE RAISED ON THE DAY SHIFT.
THE GREATEST CHANCE WILL BE W OF HWY 281. PRECIP AMOUNTS WILL BE
LIGHT IN THE PREDAWN HOURS. 03Z SREF PROBABILITIES FOR .01" IS
ONLY 50%.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 348 AM CDT THU MAR 27 2014
A FAIRLY PROGRESSIVE AND MAINLY ZONAL FLOW PATTERN WILL PERSIST
ACROSS THE CENTRAL PLAIN THROUGH MUCH OF THE EXTENDED PERIODS...
WITH BRIEF RIDGING OVER THE UPCOMING WEEKEND EXPECTED TO RESULT IN
SOME OF THE NICEST WEATHER SO FAR THIS SPRING.
STARTING OFF FRIDAY...EXPECT A MID LEVEL DISTURBANCE CROSSING THE
ROCKIES TO EMERGE INTO THE PLAINS...BRINGING THE CHANCE FOR SOME
LIGHT RAIN OR SNOW TO MUCH OF THE LOCAL AREA DURING THE DAYTIME
HOURS ON FRIDAY. WITH MODEL SOUNDINGS INDICATING THAT ANY
PRECIPITATION THAT DOES DEVELOP WILL LIKELY BE SNOW ACROSS SOUTH
CENTRAL NEBRASKA BEFORE NOON FRIDAY...WENT AHEAD AND CHANGED THE
PRECIP TYPE FOR THE MORNING HOURS NORTH OF HIGHWAY 6 TO LIGHT
SNOW...WITH LITTLE TO NO OVERALL SNOWFALL ACCUMULATION EXPECTED.
THAT SAID...WITH THE COOLER AIRMASS IN PLACE...EXPECT TEMPERATURES
TO STRUGGLE TO CLIMB INTO THE MID 40S ACROSS OUR NORTH...AND INTO
THE MID 50S ACROSS NORTH CENTRAL KANSAS BY LATE AFTERNOON...WHICH
IS ABOUT 10 DEGREES BELOW NORMAL FOR LATE MARCH.
BEHIND FRIDAYS DISTURBANCE...EXPECT AN UPPER LEVEL RIDGE ACROSS
THE INTERMOUNTAIN WEST TO TRANSITION EASTWARD...RESULTING IN
INCREASING HEIGHTS ALOFT AND WARMER TEMPERATURES FOR THE UPCOMING
WEEKEND. WHILE WINDS WILL INCREASE OUT OF THE SOUTH BOTH
DAYS...WINDS WILL GENERALLY REMAIN IN THE 10 TO 20 MPH RANGE OVER
THE UPCOMING WEEKEND...WHICH IS NOT TOO BAD COMPARED TO THE STRONG
WINDS OF LATE. OTHERWISE...THE UPPER LEVEL RIDGE THAT WILL BE
RESPONSIBLE FOR THE GENERALLY NICE WEEKEND WEATHER WILL BE QUICK
TO TRANSITION EASTWARD BY SUNDAY NIGHT AS YET ANOTHER UPPER LEVEL
DISTURBANCE CROSSES THE ROCKIES IN THE PROGRESSIVE FLOW...BRINGING
A SMALL CHANCE FOR SOME LIGHT RAINFALL MAINLY ACROSS OUR NORTH
SUNDAY NIGHT THROUGH MONDAY. THIS DISTURBANCE WILL ALSO HELP USHER
IN A WEAK COLD FRONT ACROSS THE REGION...WHICH IS EXPECTED TO DROP
TEMPERATURES BACK TO NEAR SEASONAL NORMS FOR THE REMAINDER OF THE
EXTENDED PERIODS.
THE ONLY OTHER SIGNIFICANT CHANGE TO THE EXTENDED FORECAST THIS
MORNING WAS TO INTRODUCE THE CHANCE FOR SOME ISOLATED
THUNDERSTORMS TUESDAY NIGHT THROUGH EARLY WEDNESDAY MORNING AS
SOME WEAK INSTABILITY WORKS ITS WAY NORTH ACROSS THE LOCAL AREA.
AT THIS TIME...KEPT THE MENTION OF THUNDER SOUTH OF HIGHWAY 6 AND
DO NO ANTICIPATE ANY SEVERE WEATHER AS INSTABILITY REMAINS FAIRLY
WEAK...ON THE ORDER OF ONLY A COUPLE HUNDRED JOULES NEAR THE NE/KS
STATE LINES. WHILE THERE IS SOME DISAGREEMENT AMONGST THE
MODELS...COULD SEE SOME BENEFICIAL RAINFALL WITH THIS
DISTURBANCE...BUT KEPT POPS BELOW 60 PERCENT FOR THE TIME BEING
DUE TO UNCERTAINTY IN LOCATION AND TIMING OF POTENTIAL RAINFALL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 27 2014
REST OF THE NIGHT: LIFR CIGS MAY DECAY FURTHER TO VFLIR AS THE
COLD FRONT APPROACHES AND WINDS WEAKEN. VSBY WILL ALSO DEGRADE. S
WINDS GUSTING TO NEAR 30 KTS WILL SUBSIDE BY 08Z AND THEN SHIFT TO
SE AND EVENTUALLY NE. CAN/T COMPLETELY RULE OUT A BRIEF SHWR OR
TWO. CONFIDENCE: MEDIUM
THU: LIFR CIGS AND IFR VSBYS SHOULD REMAIN UNTIL COLD FRONTAL
PASSAGE 14-15Z. A BAND OF RA/SN SHOULD MOVE THRU 15Z-19Z. WINDS
WILL BECOME NNW BEHIND THE FRONT...POSSIBLY GUSTING UP TO 39 KTS.
ONCE THE PRECIP BAND MOVES THRU CONDITIONS SHOULD IMPROVE TO MVFR.
CONFIDENCE: LOW
THU EVE THRU 06Z: BECOMING VFR WITH NW WIND LESS THAN 10 KTS.
CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...HALBLAUB
LONG TERM...SAR
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
405 AM CDT THU MAR 27 2014
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
MID/UPPER LEVEL SHORTWAVE TROUGH CONTINUES TO MOVE NORTHEAST ACROSS
NORTHEAST COLORADO AND INTO WESTERN NEBRASKA. AHEAD OF IT...A SFC
COLD FRONT EXTENDS FROM LOW PRESSURE OVER NORTHEAST COLORADO TO
ANOTHER AREA OF LOW PRESSURE OVER EASTERN SOUTH DAKOTA. THIS
BOUNDARY WILL CONTINUE TO SLOWLY SLIDE SOUTHEAST THIS MORNING
ENTERING OUR FAR NORTHWEST COUNTIES BY 12Z. THE LATEST FEW RUNS OF
THE HRRR MODEL SEEM TO HAVE A PRETTY GOOD HANDLE ON THE CURRENT
SITUATION AND HAVE FOLLOWED THE NEAR TERM FORECAST FAIRLY CLOSE TO
THIS. THIS DOES BRING THE SYSTEM THROUGH A BIT SLOWER THAN SOME OF
THE LARGER SCALE MODELS...AS WELL AS THE LATEST RAP...SO HAVE
ADJUSTED THE FORECAST ACCORDINGLY. LOW CLOUDS...FOG AND AREAS OF
DRIZZLE HAVE MOVED OVER THE FORECAST AREA EARLY THIS MORNING AHEAD
OF THE BOUNDARY. A FEW LEAD PIECES OF ENERGY MAY HELP PRODUCE AND
SPREAD SOME AREAS OF LIGHT MEASURABLE PCPN NORTHEAST THIS MORNING
SO SCATTERED SHOWERS CANNOT BE RULED OUT. UNTIL THE BETTER
FORCING MOVES INTO THE AREA ASSOCIATED WITH THE FRONTAL
CIRCULATION AND/OR THE UPPER SHORTWAVE TROUGH...EXPECT THE
FOG/DRIZZLE CONDITIONS TO CONTINUE THROUGH MID MORNING.
BEHIND THE BOUNDARY IN OUR FAR NORTH...ANY FALLING PCPN SHOULD MIX
WITH AND EVENTUALLY CHANGE OVER TO SNOW ESPECIALLY TOWARD 18Z. WE
COULD SEE AN INCH OR TWO OF ACCUMULATION ALONG THE SOUTH DAKOTA
BORDER WITH JUST A TRACE EXPECTED TO THE SOUTH. DUE TO THE SLOWER
TIMING OF THE PCPN...IT APPEARS AS THOUGH THE COLD AIR WILL HAVE
ENOUGH TIME TO SETTLE SOUTH AND PRODUCE AN INCH OR TWO.
PCPN SHOULD MOVE EAST AND OUT OF THE AREA BY LATER THIS AFTERNOON.
GUSTY NORTHWEST WINDS AND COLD AIR ADVECTION WILL LEAD TO A
BLUSTERY DAY BEHIND THE FRONT. SFC HIGH PRESSURE WILL BUILD IN
OVERNIGHT AS WEAK UPPER LEVEL RIDGING MOVES OVERHEAD. HAVE LOWERED
TEMPERATURES INTO THE UPPER TEENS IN THE NORTH WITH CLEARING SKIES
AND A BIT OF SNOW COVER.
ANOTHER SHORTWAVE TROUGH WILL MOVE INTO THE REGION ON FRIDAY. THIS
WILL BRING A SMALL CHANCE OF A RAIN/SNOW MIX TO PORTIONS OF THE
WESTERN AND NORTHERN CWA DURING THE DAYTIME HOURS.
UPPER/MID LEVEL RIDGING BUILDS OVER THE NATIONS MID SECTION ON
SATURDAY ALLOWING STRONG WARM AIR ADVECTION OVER THE AREA. SOUTHERLY
WINDS SHOULD PUSH HIGHS ON SATURDAY INTO THE 60S AND INTO THE 70S ON
SUNDAY. AS HAS BEEN THE CASE IN THE RECENT PAST...FIRE WEATHER
ISSUES WILL BE THE MAIN CONCERN OVER THE WEEKEND.
.LONG TERM...(SUNDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 AM CDT THU MAR 27 2014
UPPER/MID LEVEL FLOW BECOMES SOUTHWESTERLY ON SUNDAY AS AN
APPROACHING WESTERN TROUGH DIGS ACROSS THE WESTERN CONUS. THE
ASSOCIATE LEE SIDE SFC LOW IS FORECAST TO DRIFT EAST ACROSS NEBRASKA
SUNDAY NIGHT. MUCH OF THE FORECAST AREA LOOKS TO GET DRY SLOTTED
WITH LITTLE CHANCE OF ACCUMULATING PRECIPITATION. THE AREA THAT MAY
HAVE THE BEST CHANCE WILL BE ACROSS OUR EXTREME NORTH AS THE UPPER
SHORTWAVE MOVES ACROSS NORTHEAST NEBRASKA AND INTO NORTHERN IOWA ON
MONDAY. MUCH COLDER AIR SINKS SOUTH ALONG WITH FAIRLY STRONG
NORTHWEST WINDS WHICH COULD PRODUCE A QUITE BLUSTERY DAY WITH
FALLING DAYTIME TEMPERATURES MONDAY. SFC HIGH PRESSURE BUILDS IN
OVERNIGHT MONDAY INTO TUESDAY...WHICH WILL DROP LOWS INTO THE 2OS.
A POTENT SYSTEM WILL AFFECT THE REGION BEGINNING AS EARLY AS TUESDAY
AS RETURN FLOW SETS UP AROUND THE DEPARTING HIGH PRESSURE. A
LARGE/BROAD UPPER TROUGH IS FORECAST TO DIG ACROSS THE WESTERN THIRD
OF THE CONUS WITH LEAD SHORTWAVE ENERGY EJECTING OUT AHEAD OF IT.
THIS DYNAMIC MIDWEEK SYSTEM LOOKS TO BRING A GOOD AMOUNT OF MOISTURE
SOMEWHERE INTO THE CENTRAL PLAINS...WITH THE DETAILS IN TIMING
AND POSITIONING YET TO BE RESOLVED.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1147 PM CDT WED MAR 26 2014
IFR CONDITIONS ARE EXPECTED THROUGH THURSDAY AFTERNOON AS CIGS
LOWER TO BELOW FL010 BEFORE 12Z. AREAS OF DRIZZLE AND FOG SHOULD
KEEP VSBYS BETWEEN 3 AND 5SM AT ALL TAF SITES UNTIL A COLD FRONT
MOVES THROUGH BETWEEN 14Z AND 18Z. GUSTY SOUTH WINDS AHEAD OF THE
FRONT WILL AVERAGE 20 TO 30KT...WITH NORTHWEST WINDS OF 20 TO 35KT
BEHIND THE FRONT. AREAS OF RAIN ARE EXPECTED WITH THE FRONT...AND
A RAIN AND SNOW MIX COULD DROP VSBYS TO 2SM AT KOFK. A GRADUAL
CLEARING TREND IS EXPECTED AFTER 22Z AT ALL TAF SITES ALONG WITH
SLOWLY DECREASING WINDS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...KERN
LONG TERM...KERN
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1230 AM CDT THU MAR 27 2014
.UPDATE...
ISSUED AT 1230 AM CDT THU MAR 27 2014
WE ARE STARTING TO SEE THE FIRST LIGHTNING STRIKES OVER WRN DAWSON
COUNTY AT 05Z. SHWR ACTIVITY IS MODESTLY INCREASING. THERE IS A
BROKEN AXIS OF SHWRS FROM LEXINGTON NEB TO SALINA KS. THE HI-RES
RAP FCST REFLECTIVITY INDICATES THIS AREA OF SHWRS COULD FILL IN
AS IT HEADS NE. LIFT WILL INCREASE OVER THE FCST AREA THRU
DAYBREAK AS A 90 KT JET STREAK EJECTS INTO KS.
AS FAR AS THE FCST...POPS HAVE BEEN RECONFIGURED BLENDING WITH
CURRENT AND RAP TRENDS. FCST HOURLY TEMPS WERE RUNNING A LITTLE
TOO WARM FROM LXN-ODX AND DEWPOINTS WERE RUNNING TOO LOW. SO
CONSENSUS OF SHORT-TERM GUIDANCE WAS LOADED THRU DAWN.
UPDATE ISSUED AT 808 PM CDT WED MAR 26 2014
THE LOSS OF DIABATIC HEATING AND A RESULTANT DECREASE IN BOUNDARY
LAYER DEPTH AND MIXING ARE RESULTING IN A WEAKENING LOWER
TROPOSPHERIC WIND FIELD...A TREND WHICH IS EXPECTED TO CONTINUE
THROUGH THE REST OF TONIGHT. AS OF 01Z MOST ALL SITES ACROSS THE
CWA ARE REPORTING A WIND MAGNITUDE...BOTH SUSTAINED AND
GUST...BELOW WIND ADVISORY CRITERIA. AS A RESULT...THE WIND
ADVISORY IS NO LONGER IN EFFECT FOR THE AREA.
ALSO WENT AHEAD AND UPDATED HOURLY TEMPERATURE...DEW POINT...WIND
AND SKY GRIDS TO BETTER REFLECT CURRENT CONDITIONS.
FINALLY...DECREASING NEAR-SURFACE DEW POINT DEPRESSIONS AND STRONG
LOWER TROPOSPHERIC TURBULENT MIXING ARE HELPING PROMOTE LIGHT
DRIZZLE ACROSS PORTIONS OF THE CWA...GENERALLY SOUTH OF I-80 AND
EAST OF HIGHWAY 281. RADAR DATA FROM KUEX...AS WELL AS OBSERVATION
HERE AT THE OFFICE...SUPPORT THIS. AS A RESULT...WENT AHEAD AND
INSERTED PATCHY LIGHT DRIZZLE IN THE GRIDS FOR SOUTHEASTERN
PORTIONS OF THE CWA THROUGH 06Z.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 356 PM CDT WED MAR 26 2014
THE BIGGEST CHALLENGE WILL BE DETERMINING CHANCES OF PRECIPITATION.
UPDATED THE FORECAST THIS AFTERNOON AS A TIGHT PRESSURE GRADIENT HAS
KICKED UP WIND A LITTLE FARTHER WEST AND I HAD TO ADD A FEW COUNTIES
INTO THE WIND ADVISORY. THANKFULLY...OUR RELATIVE HUMIDITY REMAINS
HIGH ENOUGH TO NOT HAVE TO INCLUDE FIRE WEATHER HEADLINES...BUT WE
ARE GETTING CLOSE IN OUR FAR WEST AND NORTH.
FLOW REMAINS PROGRESSIVE AS A SHORTWAVE TROUGH APPROACHES. KEPT
THUNDER OUT UNTIL MID-EVENING...AND IT WILL PROBABLY ONLY OCCUR IN
THE WEST AT FIRST AS A COLD FRONT APPROACHES. WE COULD GET SOME WARM
AIR ADVECTION SHOWERS DEVELOP IN OUR SOUTHEAST THIS EVENING WITH
EVIDENCE OF MORE MOISTURE ON SATELLITE AS CLOUDS HAVE ALREADY GOTTEN
INTO THE SOUTHEASTERN CWA.
I TONED DOWN THE MENTION OF THUNDER TONIGHT AS MUCAPES DO NOT LOOK
IMPRESSIVE...AND NEITHER DO QPF AMOUNTS. OUR BEST HOPE FOR
PRECIPITATION WILL BE EARLY THURSDAY MORNING NEAR AND JUST BEHIND THE
FRONT THAT IS CURRENTLY APPROACHING FROM THE WEST...AND MORE IN OUR
NORTHERN CWA WHERE BETTER FORCING WILL OCCUR. I TEND TO LIKE CONSRAW
TEMPERATURES...WHICH LEADS ME TO A SIMILAR FORECAST FOR
PRECIPITATION TYPE FROM THE PREVIOUS FORECAST. PERHAPS SOME SNOW
MIXED WITH RAIN IN OUR NORTHWEST...BUT TEMPERATURES SHOULD REMAIN
TOO WARM TO ALLOW MUCH ACCUMULATION OF SNOW. KEPT CLOSER TO
ENSEMBLE CHANCES OF PRECIPITATION...BUT TONED DOWN A BIT AS MODELS
ARE NOT AS CONSISTENT AS I PREFER.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 356 PM CDT WED MAR 26 2014
MAIN FORECAST CONCERNS WILL BE CHANCES FOR PRECIPITATION THURSDAY
NIGHT INTO FRIDAY AND SUNDAY NIGHT AND TEMPERATURES THROUGH THE
PERIOD.
AN UPPER LEVEL WAVE WILL MOVE THROUGH THE FORECAST AREA THURSDAY
NIGHT INTO FRIDAY MORNING. THIS WILL BRING A CHANCE FOR
PRECIPITATION TO THE AREA. EXPECT LOW TEMPERATURES TO BE IN THE MID
20S TO AROUND 30 DEGREES FOR THURSDAY NIGHT...THERE WILL BE A CHANCE
FOR RAIN OR SNOW AS THE PRECIPITATION MOVES THROUGH THE AREA. BY
FRIDAY AFTERNOON THE UPPER LEVEL WAVE MOVES OUT OF THE AREA. COOLER
TEMPERATURES CONTINUE TO LINGER IN THE AREA FOR FRIDAY AND FRIDAY
NIGHT AS A SURFACE HIGH SETTLES INTO THE AREA.
BY SATURDAY MORNING THE SURFACE HIGH MOVES TO THE EAST...WINDS TURN
TO THE SOUTH AND INCREASE AND WARM ADVECTION SPREADS INTO THE AREA.
TEMPERATURES WARM INTO THE UPPER 60S TO LOWER 70S. THE WARM
WILL CONTINUE ON SUNDAY WITH EVEN WARMER TEMPERATURES
EXPECTED.
ANOTHER UPPER LEVEL WAVE WILL MOVE INTO THE AREA LATE SUNDAY NIGHT
INTO MONDAY WITH A COLD FRONT MOVING THROUGH. THERE IS ANOTHER
CHANCE FOR SOME PRECIPITATION. THIS SYSTEM IS WARMER SO THE
PRECIPITATION SHOULD BE RAIN SHOWERS. BEHIND THIS COLD FRONT
TEMPERATURES WILL BE COOLER AGAIN FOR MONDAY THROUGH WEDNESDAY BUT
WILL BE AROUND NORMAL FOR THIS TIME OF YEAR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1230 AM CDT THU MAR 27 2014
REST OF THE NIGHT: LIFR CIGS MAY DECAY FURTHER TO VFLIR AS THE
COLD FRONT APPROACHES AND WINDS WEAKEN. VSBY WILL ALSO DEGRADE. S
WINDS GUSTING TO NEAR 30 KTS WILL SUBSIDE BY 08Z AND THEN SHIFT TO
SE AND EVENTUALLY NE. CAN/T COMPLETELY RULE OUT A BRIEF SHWR OR
TWO. CONFIDENCE: MEDIUM
THU: LIFR CIGS AND IFR VSBYS SHOULD REMAIN UNTIL COLD FRONTAL
PASSAGE 14-15Z. A BAND OF RA/SN SHOULD MOVE THRU 15Z-19Z. WINDS
WILL BECOME NNW BEHIND THE FRONT...POSSIBLY GUSTING UP TO 39 KTS.
ONCE THE PRECIP BAND MOVES THRU CONDITIONS SHOULD IMPROVE TO MVFR.
CONFIDENCE: LOW
THU EVE THRU 06Z: BECOMING VFR WITH NW WIND LESS THAN 10 KTS.
CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HEINLEIN
LONG TERM...JCB
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1141 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1115 PM FRIDAY...UPDATE CONTINUES TO BE CONCERNED WITH
MASSAGING THE OVERNIGHT HOURLY POPS. LATEST MOSAIC 88D RADAR
TRENDS WILL BE MESHED WITH THE LATEST SREF MODEL PROBABILITY FOR
OVERNIGHT MEASURABLE PCPN. THIS EVOLVED INTO MODIFYING THE HRLY
POPS UP TO SEVERAL HRS AFTER DAYBREAK SAT. A COUPLE FAINT MID
LEVEL VORTS OR S/W TROFS ALOFT TO PUSH ACROSS THE FA OVERNIGHT
LENDING TO MODEST UVVS ACROSS THE FA ESPECIALLY DURING THE
PRE-DAWN SAT HRS. LATEST HRRR MODEL GUIDANCE INDICATES A MORE
WIDESPREAD PCPN SHIELD TO ENCOMPASS THE ILM CWA DURING THIS LATE
EVENING THRU THE PRE-DAWN SAT HRS. HAVE ALSO INCREASED OVERNITE
QPF BASED ON CURRENT OBSERVED ACTIVITY AND LATEST VARIOUS MODEL
QPF OUTPUT. OVERNIGHT TEMPS MAINLY WILL HOLD STEADY OR EVEN
SLIGHTLY INCREASE AS THE FA BECOMES BETTER ENTRENCHED IN THE WARM
SECTOR AHEAD OF THE MAIN UPPER S/W TROF AND ASSOCIATED SFC LOW.
PREVIOUS DISCUSSION.....................................
AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST
DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S. THE
CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO
SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT
DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD...
AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER
GENERALLY LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS
ACROSS THE EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS
AS WELL AS SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY
FLOW ACROSS THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA
COAST.
THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS
WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS
LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO
MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN
INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER
POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T
BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS
APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES
AFTER MIDNIGHT.
IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE
MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER
TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS...
PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS
EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE
GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF
NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO
GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS
WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN
WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS
TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM
AND 12Z CANADIAN OVERNIGHT.
WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD
ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS
BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS
MUCH CLOSER TO MY IDEAS THAN THE GFS MOS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER
AROUND THE COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST.
TIMING AND INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS
REMAIN THE MAIN ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR
THE LATEST UPDATES TO THE SHORT TERM.
INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE
ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME
NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY
GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY
AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF
MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR
LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR
COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO
HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP.
LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS
QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY
BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP
MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY
NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE
WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE
ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN
MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL
WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE
WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY
EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A
SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER
LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A
STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS
THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY.
&&
.AVIATION /04Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MVFR/IFR EXPECTED THROUGH THE OVERNIGHT HOURS...WITH
BRIEF INTERMITTENT PERIODS OF VFR POSSIBLE...AS VARYING LOW CIGS AND
AREAS OF RAIN MOVE THROUGH THE AREA. MIX OF VFR/MVFR/IFR CONTINUES
ON SATURDAY AS LOW TO MID CLOUDS...SHOWERS...AND ISOLATED TO
SCATTERED THUNDERSTORMS MOVE THROUGH.
LATEST RADAR IMAGERY DEPICTS ISOLATED TO SCATTERED SHOWERS MOVING
ACROSS THE AREA FROM THE SOUTHWEST. CONFIDENCE IS LOWERED THROUGH
THE OVERNIGHT HOURS REGARDING MVFR VS IFR CONDITIONS...BUT HAVE
OPTED TO GO WITH PREVAILING MVFR WITH PERIODS OF IFR AS VARYING
LOWERED CIGS MOVE ACROSS THE AREA. REDUCED VISIBILITIES ARE ALSO
EXPECTED DUE TO AREAS OF FOG AND SCATTERED SHOWERS. COULD NOT RULE
OUT PERIODS OF IMPROVED CONDITIONS TO VFR...THOUGH GIVEN UNCERTAINTY
OF WHEN THIS WOULD OCCUR HAVE NOT PUT IN FORECAST. AFTER DAYBREAK...
EXPECT VFR/MVFR WITH IFR POSSIBLE THROUGH THE MORNING HOURS.
WIDESPREAD RAINFALL THROUGHOUT THE DAY AND ISOLATED THUNDERSTORMS
IS EXPECTED WITH STRONGER STORMS POSSIBLE IN THE AFTERNOON/EVENING
HOURS. SOUTHERLY WINDS WILL PREVAIL WITH SUSTAINED WINDS AOB 12
KTS AND PERIODIC GUSTS POSSIBLE...ESPECIALLY IN STRONGER
STORMS...AROUND 20 KTS OR SLIGHTLY HIGHER.
EXTENDED OUTLOOK...BECOMING VFR SATURDAY OVERNIGHT INTO SUNDAY
WITH A SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE
NORTHERN PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1115 PM FRIDAY...THIS UPDATE REMAINS MORE CONCERNED WITH
THE INCREASED POTENTIAL FOR SEA FOG...AND THE ASSOCIATED POTENTIAL
VISIBILITY DROPPING BELOW 1 NM. THIS A RESULT OF 60+ SFC DEW
POINTS PUSHING ACROSS SHELF WATER SSTS IN THE LOW TO MID 50S.
HAVE CONTINUED THE OVERALL ONSHORE WIND REGIME FROM THE PREVIOUS
FORECAST...WITH THE PROGGED SFC PRESSURE PATTERN AND GRADIENT
KEEPING WINDS FROM THE SSE-S AT 10 TO 15 KT WIND SPEEDS. WAA
WINDS TOUGH TO MIX DOWN TO THE OCEAN SURFACE EXHIBITING 50 DEGREE
SSTS. HOWEVER...THE SFC PG IS EXPECTED TO FURTHER TIGHTEN BUT NOT
UNTIL THE MAIN SFC LOW AND COLD FRONT PUSH CLOSER TO THE FA DURING
DAYLIGHT SATURDAY. SIGNIFICANT SEAS HAVE STABILIZED LATE THIS
EVENING BUT SHOULD BEGIN TO TREND SLIGHTLY HIGHER BY OR JUST AFTER
DAYBREAK SATURDAY. BUILDING WIND DRIVEN WAVES JUST OFFSHORE...
HAVING BEEN CREATED BY THE HIER SE-S WINDS JUST OFFSHORE OVER THE
MUCH WARMER SSTS...WILL PUSH INTO THE LOCAL WATERS AND MESH WITH
THE LOCAL WAVES. SCA REMAINS BONAFIDE FOR THE REMAINDER OF
TONIGHT...WITH SIGNIFICANT SEAS THE PRIMARY REASON.
PREVIOUS DISCUSSION.....................................
AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE
CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN
APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL
HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF
THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS
10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS
OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE
COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS
WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE
WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY...
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE
WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF
15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE
CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600
AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO
20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS
WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN
THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW
DECREASE TO AROUND 15 KNOTS.
SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL
GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY
NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO
EXPIRE SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT
OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH
PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE
LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY
NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND
VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE
POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM
THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-
252-254-256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
947 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 815 PM FRIDAY...UPDATE WILL MAINLY BE CONCERNED WITH
MASSAGING THE OVERNIGHT POPS. LATEST MOSAIC 88D RADAR TRENDS
WILL BE MESHED WITH THE LATEST SREF MODEL PROBABILITY FOR
OVERNIGHT MEASURABLE PCPN. THIS EVOLVED INTO MODIFIED HRLY POPS
UP TO SEVERAL HRS AFTER DAYBREAK SAT. A COUPLE FAINT MID LEVEL
VORTS OR S/W TROFS TO PUSH ACROSS THE FA OVERNIGHT LENDING TO
MODEST UVVS ACROSS THE FA ESPECIALLY DURING THE PRE-DAWN SAT HRS.
LATEST HRRR MODEL GUIDANCE INDICATES A MORE WIDESPREAD PCPN SHIELD
TO ENCOMPASS HE ILM CWA DURING THE PRE-DAWN SAT HRS. HAVE ALSO
INCREASED OVERNITE QPF BASED ON CURRENT ACTIVITY AND LATEST
VARIOUS MODEL OUTPUT. OVERNIGHT TEMPS MAINLY WILL HOLD STEADY OR
EVEN SLIGHTLY INCREASE AS THE FA BECOMES BETTER ENTRENCHED IN THE
WARM SECTOR AHEAD OF THE MAIN UPPER S/W TROF AND ASSOCIATED SFC
LOW.
PREVIOUS DISCUSSION.................................................
AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST
DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S. THE
CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO
SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT
DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD...
AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER
GENERALLY LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS
ACROSS THE EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS
AS WELL AS SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY
FLOW ACROSS THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA
COAST.
THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS
WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS
LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO
MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN
INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER
POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T
BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS
APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES
AFTER MIDNIGHT.
IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE
MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER
TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS...
PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS
EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE
GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF
NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO
GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS
WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN
WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS
TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM
AND 12Z CANADIAN OVERNIGHT.
WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD
ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS
BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS
MUCH CLOSER TO MY IDEAS THAN THE GFS MOS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER
AROUND THE COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST.
TIMING AND INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS
REMAIN THE MAIN ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR
THE LATEST UPDATES TO THE SHORT TERM.
INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE
ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME
NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY
GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY
AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF
MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR
LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR
COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO
HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP.
LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS
QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY
BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP
MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY
NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE
WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE
ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN
MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL
WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE
WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY
EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A
SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER
LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A
STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS
THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MVFR/IFR EXPECTED THROUGH THE OVERNIGHT HOURS...WITH
BRIEF INTERMITTENT PERIODS OF VFR POSSIBLE...AS VARYING LOW CIGS AND
AREAS OF RAIN MOVE THROUGH THE AREA. MIX OF VFR/MVFR/IFR CONTINUES
ON SATURDAY AS LOW TO MID CLOUDS...SHOWERS...AND ISOLATED TO
SCATTERED THUNDERSTORMS MOVE THROUGH.
LATEST RADAR IMAGERY DEPICTS ISOLATED TO SCATTERED SHOWERS MOVING
ACROSS THE AREA FROM THE SOUTHWEST. CONFIDENCE IS LOWERED THROUGH
THE OVERNIGHT HOURS REGARDING MVFR VS IFR CONDITIONS...BUT HAVE
OPTED TO GO WITH PREVAILING MVFR WITH PERIODS OF IFR AS VARYING
LOWERED CIGS MOVE ACROSS THE AREA. REDUCED VISIBILITIES ARE ALSO
EXPECTED DUE TO AREAS OF FOG AND SCATTERED SHOWERS. COULD NOT RULE
OUT PERIODS OF IMPROVED CONDITIONS TO VFR...THOUGH GIVEN UNCERTAINTY
OF WHEN THIS WOULD OCCUR HAVE NOT PUT IN FORECAST. AFTER
DAYBREAK...EXPECT VFR/MVFR WITH IFR POSSIBLE THROUGH THE MORNING HOURS.
WIDESPREAD RAINFALL THROUGHOUT THE DAY AND ISOLATED THUNDERSTORMS IS
EXPECTED WITH STRONGER STORMS POSSIBLE IN THE AFTERNOON/EVENING
HOURS. SOUTHERLY WINDS WILL PREVAIL WITH SUSTAINED WINDS AOB 12 KTS
AND PERIODIC GUSTS POSSIBLE...ESPECIALLY IN STRONGER STORMS...AROUND
20 KTS OR SLIGHTLY HIGHER.
EXTENDED OUTLOOK...BECOMING VFR SATURDAY OVERNIGHT INTO SUNDAY
WITH A SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE
NORTHERN PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 830 PM FRIDAY...THE UPDATE WILL BE MORE CONCERNED WITH THE
INCREASED POTENTIAL FOR SEA FOG...AND THE ASSOCIATED POTENTIAL
VISIBILITY DROPPING BELOW 1 NM. THIS A RESULT OF 60+ SFC DEW
POINTS PUSHING ACROSS SHELF WATER SSTS IN THE LOW TO MID 50S.
HAVE MAINTAINED THE OVERALL WIND REGIME FROM THE PREVIOUS
FORECAST...KEEPING IT FROM THE SSE-S AT 10 TO 15 KT WIND SPEEDS.
WAA WINDS TOUGH TO MIX DOWN TO THE OCEAN SURFACE EXHIBITING 50
DEGREE SSTS. HOWEVER...THE SFC PG IS EXPECTED TO FURTHER TIGHTEN
BUT NOT UNTIL THE MAIN SFC LOW AND COLD FRONT PUSH CLOSER TO THE
FA DURING DAYLIGHT SATURDAY. SIGNIFICANT SEAS HAVE BEEN TRENDED
SLIGHTLY LOWER BUT REMAINING WITHIN SCA CRITERIA. BUILDING WIND
DRIVEN WAVES JUST OFFSHORE HAVING BEEN CREATED BY THE HIER SE-S
WINDS JUST OFFSHORE OVER THE MUCH WARMER SSTS...WILL PUSH ACROSS
THE LOCAL WATERS AND MESH WITH THE LOCAL WAVES.
PREVIOUS DISCUSSION.................................................
AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE
CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN
APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL
HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF
THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS
10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS
OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE
COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS
WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE
WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY...
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE
WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF
15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE
CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600
AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO
20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS
WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN
THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW
DECREASE TO AROUND 15 KNOTS.
SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL
GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY
NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO
EXPIRE SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT
OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH
PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE
LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY
NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND
VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE
POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM
THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
752 PM EDT FRI MAR 28 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL LATER NEXT WEEK. A COLD
FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST
DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S. THE
CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO
SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT
DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD...
AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER
GENERALLY LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS
ACROSS THE EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS
AS WELL AS SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY
FLOW ACROSS THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA
COAST.
THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS
WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS
LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO
MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN
INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER
POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T
BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS
APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES
AFTER MIDNIGHT.
IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE
MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER
TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS...
PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS
EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE
GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF
NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO
GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS
WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN
WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS
TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM
AND 12Z CANADIAN OVERNIGHT.
WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD
ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS
BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS
MUCH CLOSER TO MY IDEAS THAN THE GFS MOS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER
AROUND THE COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST.
TIMING AND INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS
REMAIN THE MAIN ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR
THE LATEST UPDATES TO THE SHORT TERM.
INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE
ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME
NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY
GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY
AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF
MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR
LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR
COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO
HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP.
LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS
QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY
BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP
MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY
NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE
WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE
ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN
MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL
WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE
WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY
EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A
SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER
LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A
STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS
THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 00Z...MVFR/IFR EXPECTED THROUGH THE OVERNIGHT HOURS...WITH
BRIEF INTERMITTENT PERIODS OF VFR POSSIBLE...AS VARYING LOW CIGS AND
AREAS OF RAIN MOVE THROUGH THE AREA. MIX OF VFR/MVFR/IFR CONTINUES
ON SATURDAY AS LOW TO MID CLOUDS...SHOWERS...AND ISOLATED TO
SCATTERED THUNDERSTORMS MOVE THROUGH.
LATEST RADAR IMAGERY DEPICTS ISOLATED TO SCATTERED SHOWERS MOVING
ACROSS THE AREA FROM THE SOUTHWEST. CONFIDENCE IS LOWERED THROUGH
THE OVERNIGHT HOURS REGARDING MVFR VS IFR CONDITIONS...BUT HAVE
OPTED TO GO WITH PREVAILING MVFR WITH PERIODS OF IFR AS VARYING
LOWERED CIGS MOVE ACROSS THE AREA. REDUCED VISIBILITIES ARE ALSO
EXPECTED DUE TO AREAS OF FOG AND SCATTERED SHOWERS. COULD NOT RULE
OUT PERIODS OF IMPROVED CONDITIONS TO VFR...THOUGH GIVEN UNCERTAINTY
OF WHEN THIS WOULD OCCUR HAVE NOT PUT IN FORECAST. AFTER
DAYBREAK...EXPECT VFR/MVFR WITH IFR POSSIBLE THROUGH THE MORNING HOURS.
WIDESPREAD RAINFALL THROUGHOUT THE DAY AND ISOLATED THUNDERSTORMS IS
EXPECTED WITH STRONGER STORMS POSSIBLE IN THE AFTERNOON/EVENING
HOURS. SOUTHERLY WINDS WILL PREVAIL WITH SUSTAINED WINDS AOB 12 KTS
AND PERIODIC GUSTS POSSIBLE...ESPECIALLY IN STRONGER STORMS...AROUND
20 KTS OR SLIGHTLY HIGHER.
EXTENDED OUTLOOK...BECOMING VFR SATURDAY OVERNIGHT INTO SUNDAY
WITH A SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE
NORTHERN PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE
CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN
APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL
HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF
THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS
10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS
OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE
COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS
WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE
WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY...
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE
WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF
15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE
CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600
AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO
20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS
WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN
THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW
DECREASE TO AROUND 15 KNOTS.
SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL
GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY
NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO
EXPIRE SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT
OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH
PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE
LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY
NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND
VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE
POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM
THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...SGL
AREA FORECAST DISCUSSION
NWS BISMARCK ND
107 AM CDT THU MAR 27 2014
.UPDATE...
ISSUED AT 107 AM CDT THU MAR 27 2014
UPDATES MINOR WITH THIS FORECAST ISSUANCE. CLOUDS PERSIST WITH
LITTLE IF ANY SNOW AT THE MOMENT. WINDS STILL EXPECTED TO INCREASE
SOUTH CENTRAL AND SOUTHEAST AS LOW PRESSURE OVER THE CENTRAL
PLAINS DEEPENS. WILL SEE INCREASING CHANCES FOR LIGHT SNOW FAR
SOUTHEAST AS WE APPROACH DAYBREAK.
UPDATE ISSUED AT 954 PM CDT WED MAR 26 2014
NO MAJOR UPDATES WERE REQUIRED TO THE ONGOING FORECAST. ONLY MADE
MINOR ADJUSTMENTS TO THE SENSIBLE WEATHER GRIDS BASED ON CURRENT
OBS/TRENDS. THE UPDATED PRODUCTS HAVE BEEN SENT.
UPDATE ISSUED AT 718 PM CDT WED MAR 26 2014
REGIONAL RADARS DEPICT A BAND OF PRECIPITATION EXTENDING FROM GLEN
ULLIN TO UNDERWOOD TO HARVEY. HOWEVER...NONE OF THE SURFACE
OBSERVATIONS ARE REPORTING PRECIPITATION. THE 00Z KBIS SOUNDING
SHOWS A SHALLOW MOIST LAYER AROUND 850MB...AND A DRY LAYER FROM
850MB TO THE SURFACE. GIVEN THE DRY BOUNDARY LAYER CONDITIONS...DO
NOT THINK MUCH (IF ANY) PRECIPITATION WILL REACH THE GROUND.
FURTHERMORE...SATELLITE DATA SHOWS CLEARING OVER EASTERN
MONTANA/WESTERN NORTH DAKOTA INDICATIVE OF DRYER AIR MOVING IN.
GIVEN THESE PARAMETERS...UPDATED THE FORECAST TO LOWER POPS
SUBSTANTIALLY THIS EVENING.
LOW PRESSURE IS STILL FORECAST TO DEEPEN OVER EASTERN SOUTH DAKOTA
TONIGHT. LIGHT SNOW COULD AFFECT THE SOUTHERN JAMES RIVER BASIN
AFTER MIDNIGHT AS A RESULT. FOR NOW LEFT CHANCE POPS IN FOR THE
SOUTHEASTERN CWA AFTER MIDNIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 338 PM CDT WED MAR 26 2014
ALTHOUGH LOW LEVEL MOISTURE IS MORE LIMITED THAN EARLIER
THOUGHT...VISIBLE SATELLITE LOOPS SHOW CONVECTIVE LOOKING MID
LEVEL CLOUDS. RAP MID LEVEL LAPSE RATES ARE CLOSE TO ADIABATIC
AND BUFKIT SOUNDINGS SHOW 12K-15K FEET AGL SATURATION IN THE
DENDRITIC GROWTH ZONE. SO SHOULD SEE SOME FLAKE SHOWING UP AT THE
SURFACE EVENTUALLY. DID REDUCE THE CHANCE OF SNOW CONSIDERABLY
ACROSS THE WEST. LEFT THE BEST CHANCE AT LIKELY NORTH CENTRAL THIS
EVENING. THE BETTER CHANCE OF PRECIPITATION WILL TRANSITION TO
THE AREA SOUTH AND EAST OF THE JAMES RIVER VALLEY ON THURSDAY.
ON THURSDAY...A SURFACE HIGH WILL PUSH SOUTH INTO CENTRAL NORTH
DAKOTA. THE JAMES RIVER VALLEY WILL SEE INCREASED WINDS OF 20 TO
30 MPH THURSDAY AFTERNOON...BUT BELOW WIND ADVISORY CRITERIA.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 338 PM CDT WED MAR 26 2014
THE MAIN FORECAST HIGHLIGHTS IN THE LONG TERM PERIOD ARE A SERIES
OF STORMS SYSTEMS THAT WILL IMPACT THE NORTHERN PLAINS IN A MORE
ACTIVE...LESS AMPLIFIED PATTERN.
ON THURSDAY NIGHT AND FRIDAY...A COOL SURFACE HIGH OVER SOUTHERN
CANADA AND THE DAKOTAS WILL SLIDE SOUTHEAST AS A WEAK UPPER LEVEL
SHORTWAVE MOVES SOUTHEAST FROM MONTANA TO THE CENTRAL PLAINS. THIS
WILL INDUCE LOW PRESSURE OVER EASTERN MONTANA/WY/WESTERN DAKOTAS
THURSDAY NIGHT WHICH WILL ALSO MOVE/DEVELOP SOUTHEAST ON FRIDAY.
LIGHT RAIN/SNOW IS POSSIBLE ACROSS THE WESTERN HALF OF THE STATE
THURSDAY NIGHT...AND OVER ALL OF WESTERN AND CENTRAL NORTH DAKOTA ON
FRIDAY. CONTINUED COOL THIS PERIOD WITH LOWS THURSDAY NIGHT FROM
ZERO TO 20 ABOVE...AND HIGHS FRIDAY FROM THE 20S TO NEAR 40.
FRIDAY NIGHT AND SATURDAY...A WARM-UP BEGINS WITH A LOW PRESSURE
SYSTEM EXPECTED TO DEVELOP OVER THE ROCKIES OF SOUTHERN
ALBERTA/MONTANA. THIS WILL INDUCE SOUTHERLY WINDS ACROSS THE REGION.
AFTER LOWS FRIDAY NIGHT IN THE TEENS NORTH CENTRAL TO 20S
ELSEWHERE...EXPECT A NICE WARM-UP SATURDAY WITH HIGHS REACHING THE
40S IN THE TURTLE MOUNTAINS TO THE UPPER 50S SOUTH AND WEST OF THE
MISSOURI RIVER.
SATURDAY NIGHT THROUGH SUNDAY NIGHT...THE LOW PRESSURE SYSTEM THAT
WILL BRING THE SATURDAY WARM-UP WILL DEEPEN AND BEGIN TO
MOVE/DEVELOP OVER WYOMING/SOUTH DAKOTA AS A SIGNIFICANT LONGWAVE
TROUGH MOVES EAST ACROSS THE ROCKIES. THIS SYSTEM WILL INTENSIFY AS
IT CONTINUES EASTWARD INTO IOWA/MINNESOTA BY DAYBREAK MONDAY. THIS
SYSTEM WILL BRING A LARGE AREA OF RAIN AND SNOW TO THE CENTRAL AND
NORTHERN PLAINS. EXPECT CHANCES OF RAIN SATURDAY NIGHT...CHANGING TO
SNOW SUNDAY MORNING...THEN BACK TO RAIN ACROSS THE SOUTH SUNDAY
AFTERNOON...BEFORE BACK TO ALL SNOW SUNDAY NIGHT. THIS SCENARIO
WOULD RESULT IN A COUPLE OF INCHES OF SNOW IN THE NORTH
CENTRAL...WITH MORE RAIN THAN SNOW SOUTH. LOWS SATURDAY NIGHT SHOULD
BE IN THE 20S TO LOWER 30S...WITH HIGHS SUNDAY RANGING FROM 30 NORTH
TO THE 40S SOUTH.
THE NEXT SYSTEM TO AFFECT THE AREA DEVELOPS IN THE ROCKIES NEAR
COLORADO MONDAY NIGHT/TUESDAY AND EMERGES INTO THE PLAINS
TUESDAY/TUESDAY NIGHT AND DEVELOPING IN THE MISSISSIPPI AND OHIO
VALLEYS WEDNESDAY NIGHT. THIS SYSTEM HAS THE POTENTIAL FOR RAIN AND
SNOW ACROSS THE NORTHERN PLAINS...BUT MUCH UNCERTAINTY REMAINS WITH
THE EVOLUTION OF THIS SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 107 AM CDT THU MAR 27 2014
VFR TO MARGINAL MVFR CIGS ARE EXPECTED OVER WEST AND CENTRAL
NORTH DAKOTA THROUGH 15Z THIS MORNING. AREA OF MVFR CIGS ACROSS
THE AREA RIGHT NOW...AND COULD BECOME MORE WIDESPREAD WITH TIME
OVER THE NEXT FEW HOURS. FURTHERMORE...WINDS WILL INCREASE
TONIGHT THROUGH THURSDAY OVER KBIS-KJMS AS LOW PRESSURE DEEPENS
ACROSS THE CENTRAL PLAINS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...WAA
LONG TERM...JV
AVIATION...NH
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
151 PM EDT THU MAR 27 2014
.SYNOPSIS...
SOUTH WINDS WILL INCREASE TODAY AHEAD OF LOW PRESSURE TRACKING TO
THE GREAT LAKES FROM THE MIDWEST. A COLD FRONT WILL CROSS THE OHIO
VALLEY EARLY FRIDAY. LOW PRESSURE WILL CROSS THE TENNESSEE VALLEY
AND OVERSPREAD RAIN TO THE SOUTHERN OHIO VALLEY REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED SHOWERS ARE PERSISTING ACROSS THE AREA THIS MORNING. THE
LAST FEW RUNS OF THE HRRR SEEM TO HAVE THE BEST HANDLE ON THE
CURRENT SITUATION AND IT IS LINGERING THE SHOWERS ACROSS THE AREA
ON INTO THIS AFTERNOON. HAVE THEREFORE UPDATED TO HANG ON TO
CHANCE POPS ACROSS THE ENTIRE AREA A LITTLE LONGER INTO EARLY
THIS AFTERNOON. THIS WILL LIKELY HELP KEEP THE RH AND/OR FUEL
MOISTURE UP A BIT MORE THAN PREVIOUSLY THOUGHT. WILL GO AHEAD AND
LEAVE THE RED FLAG WARNING UP FOR NOW SINCE WE MAY STILL GET
CLOSE TO RH/FUEL MOISTURE CRITERIA AND IT WILL STILL GET PRETTY
WINDY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
LOW PRESSURE WILL TRACK FROM THE MIDWEST TO THE GREAT LAKES AND A
LOW LEVEL JET OF 60-70KT WILL PROVIDE AN EFFECTIVE MOISTURE
TRANSPORT TO THE OHIO VALLEY. SHOWERS WILL GET WRUNG OUT AS THE
UPPER LEVEL TROUGH APPROACHES THIS EVENING AND OVERNIGHT. ENOUGH
SLANT WISE CONVECTION WILL PERMIT SOME THUNDER TO OCCUR WITH THIS
ROUND OF SHOWERS. MILD AIR WILL BE PULLED INTO THE REGION UNTIL
THE FRONT PASSES FRIDAY AND COLDER AIR GETS PULLED IN FRIDAY
NIGHT.
HIGH PRESSURE WILL BUILD IN THE GREAT LAKES FRIDAY NIGHT AND
SATURDAY. THIS WILL HELP PROVIDE SOME CONVERGENCE OVER THE LOWER
OHIO VALLEY AS THE NEXT LOW GETS PULLED NORTHEAST AND CLIPS THE
SOUTHEASTERN CWA. THE STRONG UPPER LEVEL TROUGH MEETING THE
SURFACE LOW WILL QUICKLY CROSS LATE SATURDAY AND RAPIDLY TURN OFF
ANY PRECIPITATION. ENOUGH COLD AIR MAY BE PRESENT ON THE
NORTHWEST SIDE OF THIS SYSTEM THAT RAIN COULD MIX WITH
SNOW...PARTICULARLY SATURDAY EVENING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
HIGH PRESSURE AND DRY CONDITIONS CAN BE EXPECTED FOR SUNDAY INTO
SUNDAY NIGHT. SOUTHERLY WINDS PICK UP ON MONDAY ALLOWING FOR
TEMPERATURES TO INCREASE INTO THE 60S ACROSS THE FA. AN UPPER
LEVEL DISTURBANCE WILL BEGIN TO WORK INTO THE AREA MONDAY
AFTERNOON INTO MONDAY NIGHT BEFORE EXITING THE AREA TUESDAY
MORNING. COOLER AIR WILL THEN BE BROUGHT BACK INTO THE AREA FOR
TUESDAY WITH HIGH TEMPERATURES IN THE 40S AND 50S. ANOTHER SYSTEM
WILL BEGIN TO APPROACH THE AREA FOR WEDNESDAY BRINGING A CHANCE
FOR SHOWERS TO THE REGION.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SHOWER ACTIVITY IS PUSHING EAST NORTH EAST ACROSS THE AREA THIS
AFTERNOON ASSOCIATED WITH A WARM FRONT LIFTING NORTH THROUGH THE
REGION. THE STEADIEST PCPN IS ALONG AND NORTH OF INTERSTATE 70 SO
THINK IT WILL GENERALLY REMAIN NORTH OF THE TAF SITES THROUGH THE
REST OF THE AFTERNOON. SOME SPOTTY SHOWERS WILL STILL BE POSSIBLY
TO THE SOUTH OF THERE THOUGH SO WILL ALLOW FOR A VCSH INTO THIS
EVENING FOR ALL OF THE TAF SITES. DEEPER MOISTURE WILL MOVE IN
FROM THE WEST TONIGHT AHEAD OF AN APPROACHING COLD FRONT. AS IT
DOES...EXPECT RAIN TO BECOME MORE WIDESPREAD FROM WEST TO EAST
LATER THIS EVENING AND THROUGH THE OVERNIGHT HOURS. AS WE WILL
STILL BE IN THE WARM SECTOR...WILL NOT TAKE CIGS AS LOW AS
SUGGESTED BY THE 12Z NAM...AND GENERALLY JUST HAVE MVFR
RESTRICTIONS. WITH A TIGHTENING PRESSURE GRADIENT...WINDS WILL
REMAIN GUSTY AHEAD OF THE FRONT...WITH GUSTS IN THE 20 TO 30 KNOT
RANGE POSSIBLE THROUGH TONIGHT. THE COLD FRONT WILL PUSH EAST
ACROSS THE AREA ON FRIDAY WITH WINDS BECOMING WESTERLY AND PCPN TAPERING
OFF THROUGH THE LATE MORNING HOURS.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR OHZ064-065-
073-074-079>082-088.
KY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR KYZ097>100.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...NOVAK
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1016 AM EDT THU MAR 27 2014
.SYNOPSIS...
SOUTH WINDS WILL INCREASE TODAY AHEAD OF LOW PRESSURE TRACKING TO
THE GREAT LAKES FROM THE MIDWEST. A COLD FRONT WILL CROSS THE OHIO
VALLEY EARLY FRIDAY. LOW PRESSURE WILL CROSS THE TENNESSEE VALLEY
AND OVERSPREAD RAIN TO THE SOUTHERN OHIO VALLEY REGION SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SCATTERED SHOWERS ARE PERSISTING ACROSS THE AREA THIS MORNING. THE
LAST FEW RUNS OF THE HRRR SEEM TO HAVE THE BEST HANDLE ON THE
CURRENT SITUATION AND IT IS LINGERING THE SHOWERS ACROSS THE AREA
ON INTO THIS AFTERNOON. HAVE THEREFORE UPDATED TO HANG ON TO
CHANCE POPS ACROSS THE ENTIRE AREA A LITTLE LONGER INTO EARLY
THIS AFTERNOON. THIS WILL LIKELY HELP KEEP THE RH AND/OR FUEL
MOISTURE UP A BIT MORE THAN PREVIOUSLY THOUGHT. WILL GO AHEAD AND
LEAVE THE RED FLAG WARNING UP FOR NOW SINCE WE MAY STILL GET
CLOSE TO RH/FUEL MOISTURE CRITERIA AND IT WILL STILL GET PRETTY
WINDY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY NIGHT/...
LOW PRESSURE WILL TRACK FROM THE MIDWEST TO THE GREAT LAKES AND A
LOW LEVEL JET OF 60-70KT WILL PROVIDE AN EFFECTIVE MOISTURE
TRANSPORT TO THE OHIO VALLEY. SHOWERS WILL GET WRUNG OUT AS THE
UPPER LEVEL TROUGH APPROACHES THIS EVENING AND OVERNIGHT. ENOUGH
SLANT WISE CONVECTION WILL PERMIT SOME THUNDER TO OCCUR WITH THIS
ROUND OF SHOWERS. MILD AIR WILL BE PULLED INTO THE REGION UNTIL
THE FRONT PASSES FRIDAY AND COLDER AIR GETS PULLED IN FRIDAY
NIGHT.
HIGH PRESSURE WILL BUILD IN THE GREAT LAKES FRIDAY NIGHT AND
SATURDAY. THIS WILL HELP PROVIDE SOME CONVERGENCE OVER THE LOWER
OHIO VALLEY AS THE NEXT LOW GETS PULLED NORTHEAST AND CLIPS THE
SOUTHEASTERN CWA. THE STRONG UPPER LEVEL TROUGH MEETING THE
SURFACE LOW WILL QUICKLY CROSS LATE SATURDAY AND RAPIDLY TURN OFF
ANY PRECIPITATION. ENOUGH COLD AIR MAY BE PRESENT ON THE
NORTHWEST SIDE OF THIS SYSTEM THAT RAIN COULD MIX WITH
SNOW...PARTICULARLY SATURDAY EVENING.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
HIGH PRESSURE AND DRY CONDITIONS CAN BE EXPECTED FOR SUNDAY INTO
SUNDAY NIGHT. SOUTHERLY WINDS PICK UP ON MONDAY ALLOWING FOR
TEMPERATURES TO INCREASE INTO THE 60S ACROSS THE FA. AN UPPER
LEVEL DISTURBANCE WILL BEGIN TO WORK INTO THE AREA MONDAY
AFTERNOON INTO MONDAY NIGHT BEFORE EXITING THE AREA TUESDAY
MORNING. COOLER AIR WILL THEN BE BROUGHT BACK INTO THE AREA FOR
TUESDAY WITH HIGH TEMPERATURES IN THE 40S AND 50S. ANOTHER SYSTEM
WILL BEGIN TO APPROACH THE AREA FOR WEDNESDAY BRINGING A CHANCE
FOR SHOWERS TO THE REGION.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHRA HAS DEVELOPED OVER INDIANA ALONG A DEVELOPING WRMFNT. THE WRN
TAFS COULD BE AFFECTED BY THIS PCPN FOR THE FIRST PART OF THE PERIOD...BUT
KEPT THE CIGS AND VSBYS VFR.
WINDS WILL INCREASE DURING THE MORNING AS THE SFC PRESSURE
GRADIENT TIGHTENS AHEAD OF A SFC LOW IN THE COUNTRYS MID SECTION.
GUSTS COULD BE AS HIGH AS 30 KT DURING THE AFTERNOON. HELD OFF ON
PUTTING PREVAILING SHRA IN THE TAFS UNTIL AFTER 00Z. LINE OF SHOWERS
IS THEN EXPECTED TO MOVE INTO THE TAFS. THERE IS SOME WEAK
ELEVATED INSTABILITY TONIGHT...BUT WILL LEAVE MENTION OF TS OUT
FOR NOW. VSBYS SHOULD DROP INTO MVFR RANGE WITH THE SHOWERS.
BEHIND THE INITIAL AND PROBABLY STRONGEST SHOWERS...CIGS ARE FCST
TO LOWER INTO THE MVFR CATEGORY.
IN THE EXTENDED PORTION OF THE CVG TAF...FROPA WILL OCCURS AROUND
12 FRIDAY. THIS SHOULD BRING AN END TO THE PCPN...BUT CIGS WILL
REMAIN MVFR.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY FRIDAY AND AGAIN
SATURDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR OHZ064-065-
073-074-079>082-088.
KY...RED FLAG WARNING UNTIL 7 PM EDT THIS EVENING FOR KYZ097>100.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...NOVAK
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS TULSA OK
1155 AM CDT THU MAR 27 2014
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
MVFR CIGS WILL GRADUALLY LIFT FROM W TO E THIS AFTN...AS DRIER AIR
MOVES INTO THE TAF SITES. GUSTY S TO SW WINDS WILL CONTINUE
THROUGH THE AFTN WITH THE GUST SPEED DROPPING OFF THROUGH LATE
AFTN. TSRA POTENTIAL GREATEST AFTER 00Z AT THE AR TERMINALS...BUT
CONFIDENCE AT ANY ONE TERMINAL NOT GREAT ENOUGH TO GO ANY HIGHER
THAN A VCTS. IF IT BECOMES MORE CERTAIN THAT A LINE OF TSRA ALONG
THE COLD FRONT WILL AFFECT ANY OF THE TERMINALS...AMENDMENTS WILL
BE ISSUED. WINDS WILL BECOME NORTHERLY BEHIND THE FRONT OVERNIGHT.
MVFR CIGS WILL AGAIN BE POSSIBLE AT THE AR TERMINALS...NEAR THE
STALLED BOUNDARY.
&&
.PREV DISCUSSION... /ISSUED 1028 AM CDT THU MAR 27 2014/
..UPDATE...
DISCUSSION...
NOT MUCH HAS CHANGED IN THE THINKING REGARDING SEVERE POTENTIAL OR
THE FIRE WEATHER POTENTIAL FOR THIS AFTERNOON/EVENING. SEVERE
WEATHER THREAT CONTINUES TO LOOK HIGHLY CONDITIONAL...WITH
THUNDERSTORM COVERAGE NOT LIKELY TO BE VERY GREAT ACROSS FAR
EASTERN OKLAHOMA OR NORTHWEST/WEST CENTRAL ARKANSAS. SUFFICIENT
INSTABILITY AND CERTAINLY WIND SHEAR WILL EXIST FOR LARGE
HAIL/DAMAGING WINDS AND EVEN ISOLATED TORNADOES...WITH THE
GREATEST POTENTIAL WITH ANY ISOLATED STORMS THAT ARE ABLE TO
DEVELOP ALONG THE DRYLINE. INITIATION WOULD LIKELY BE IN THE 21 TO
00Z TIME FRAME...AND LIKELY CLOSER TO 00Z. DATA FROM THE LOCAL
WRF AND THE HRRR CURRENTLY KEYING ON PARTS OF NORTHWEST ARKANSAS
FOR THE GREATEST SEVERE POTENTIAL SO WILL BE WATCHING THIS AREA
CLOSELY. IF THIS SHOWS TO BE CONSISTENT...SEVERE PROBABILITIES
WILL BE ADJUSTED ACCORDINGLY LATER TODAY.
REGARDING FIRE WEATHER POTENTIAL...IT STILL APPEARS THAT PARTS OF
NORTHEAST OKLAHOMA...GENERALLY WEST OF HIGHWAY 75...WILL APPROACH
RED FLAG CRITERIA ONCE THE DRYLINE PASSES...BUT THE EXPECTATION IS
THAT WINDS WILL DROP OFF ENOUGH TO NOT WARRANT A WARNING. IT IS
ALSO CERTAINLY POSSIBLE THAT PARTS OF THE ONGOING WIND ADVISORY
WILL BE DROPPED EARLIER THAN 00Z IN A WEST TO EAST FASHION.
PREV DISCUSSION... /ISSUED 629 AM CDT THU MAR 27 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
GUSTY SOUTH SFC WINDS WILL PREVAIL FOR MUCH OF THE DAY ALONG WITH
MVFR CIGS. A SURFACE DRY LINE WILL MOVE THROUGH THE ERN OK TAF
SITES THIS AFTERNOON...RESULTING IN A WIND SHIFT TO THE WEST
SOUTHWEST. THUNDERSTORM INITIATION EXPECTED ACROSS FAR ERN OK
LATER IN THE AFTERNOON. SCATTERED COVERAGE WOULD IMPACT THE AR TAF
SITES WITH VFR CIGS AND VSBYS FROM LATE AFTERNOON INTO THE
EVENING...AND WARRANTS A PROB30 GROUP AT THIS TIME. A COLD FRONT
WILL CATCH UP WITH THE DRY LINE THIS EVENING...RESULTING IN A
SHIFT TO THE NORTH ALONG WITH A MORE RELAXED GRADIENT.
PREV DISCUSSION... /ISSUED 422 AM CDT THU MAR 27 2014/
DISCUSSION...
A WINDY AND WARM DAY IS ON TAP TODAY AND A WIND ADVISORY WILL BE
POSTED FOR NORTHEAST OKLAHOMA AND THE NORTHWEST CORNER OF ARKANSAS
FROM NOW UNTIL 6 PM. PARTS OF THE ADVISORY AREA WILL LIKELY SEE
GUSTS DROP BELOW 40 MILES AN HOUR PRIOR TO THAT TIME AS THE
GRADIENT RELAXES SOME THIS AFTERNOON BUT NORTHWEST ARKANSAS MAY
SEE GUSTS NEAR 40 UNTIL 5-6 PM.
A FEW ELEVATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS
MORNING INTO EARLY AFTERNOON...ESPECIALLY IN THE EASTERN PART OF
THE FORECAST AREA. BY LATE AFTERNOON AND ESPECIALLY EARLY
EVENING...SURFACE BASED THUNDERSTORM DEVELOPMENT WILL BECOME
INCREASINGLY LIKELY ALONG THE DRYLINE AND THE COLD FRONT WHICH
WILL BE OVERTAKING THE DRYLINE THIS EVENING. A FEW OF THESE STORMS
MAY BE SEVERE WITH FAR EASTERN OKLAHOMA AND NORTHWEST ARKANSAS
MOST LIKELY TO BE IMPACTED.
AN ELEVATED FIRE DANGER WILL ALSO EXIST TODAY...BUT CONDITIONS
WILL LIKELY STAY BELOW RED FLAG CRITERIA. A FIRE DANGER STATEMENT
WILL BE ISSUED TO COVER THIS THREAT.
THE COLD FRONT WILL STALL FROM CENTRAL ARKANSAS INTO SOUTHEAST
OKLAHOMA AND AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE
WEST...SHOWER AND THUNDERSTORM DEVELOPMENT WILL OCCUR AGAIN
FRIDAY. NORTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA WILL BE MOST
IMPACTED...BUT THE ECMWF IS FURTHER WEST WITH CONVECTION AND SO
POPS ARE WARRANTED IN ALL AREAS.
THE WEEKEND WILL FEATURE DRY WEATHER WITH A WARMING TREND.
INCREASING SOUTHERLY WINDS WILL RESULT IN AN ELEVATED FIRE DANGER
AGAIN BY SUNDAY. THE NEXT COLD FRONT IS DUE TO MOVE ACROSS THE
AREA LATE MONDAY AND MONDAY NIGHT AND WILL LIKELY COME THROUGH
DRY. THIS FRONT WILL STALL NEAR THE RED RIVER BEFORE LIFTING BACK
NORTH AS A WARM FRONT LATE TUESDAY AND TUESDAY NIGHT.
ANOTHER COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY INTO
EARLY THURSDAY. LOW LEVEL MOISTURE WILL HAVE INCREASED ENOUGH BY
THAT TIME TO WARRANT A CHANCE OF SHOWERS AND THUNDERSTORMS WITH
THIS FRONT.
STAYED CLOSE TO GUIDANE TEMPERATURES FOR THE NEXT COUPLE DAYS
EXCEPT WENT A BIT COOLER THAN GUIDANCE IN SOME PLACES FOR HIGHS
FRIDAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 7 PM THURSDAY FOR OKZ054-OKZ055-OKZ056-
OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-OKZ064-
OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071.
AR...WIND ADVISORY UNTIL 7 PM THURSDAY FOR ARZ001-ARZ002-ARZ010-
ARZ011.
&&
$$
AVIATION...22
AREA FORECAST DISCUSSION
NWS TULSA OK
1028 AM CDT THU MAR 27 2014
...UPDATE...
.DISCUSSION...
NOT MUCH HAS CHANGED IN THE THINKING REGARDING SEVERE POTENTIAL OR
THE FIRE WEATHER POTENTIAL FOR THIS AFTERNOON/EVENING. SEVERE
WEATHER THREAT CONTINUES TO LOOK HIGHLY CONDITIONAL...WITH
THUNDERSTORM COVERAGE NOT LIKELY TO BE VERY GREAT ACROSS FAR
EASTERN OKLAHOMA OR NORTHWEST/WEST CENTRAL ARKANSAS. SUFFICIENT
INSTABILITY AND CERTAINLY WIND SHEAR WILL EXIST FOR LARGE
HAIL/DAMAGING WINDS AND EVEN ISOLATED TORNADOES...WITH THE
GREATEST POTENTIAL WITH ANY ISOLATED STORMS THAT ARE ABLE TO
DEVELOP ALONG THE DRYLINE. INITIATION WOULD LIKELY BE IN THE 21 TO
00Z TIME FRAME...AND LIKELY CLOSER TO 00Z. DATA FROM THE LOCAL
WRF AND THE HRRR CURRENTLY KEYING ON PARTS OF NORTHWEST ARKANSAS
FOR THE GREATEST SEVERE POTENTIAL SO WILL BE WATCHING THIS AREA
CLOSELY. IF THIS SHOWS TO BE CONSISTENT...SEVERE PROBABILITIES
WILL BE ADJUSTED ACCORDINGLY LATER TODAY.
REGARDING FIRE WEATHER POTENTIAL...IT STILL APPEARS THAT PARTS OF
NORTHEAST OKLAHOMA...GENERALLY WEST OF HIGHWAY 75...WILL APPROACH
RED FLAG CRITERIA ONCE THE DRYLINE PASSES...BUT THE EXPECTATION IS
THAT WINDS WILL DROP OFF ENOUGH TO NOT WARRANT A WARNING. IT IS
ALSO CERTAINLY POSSIBLE THAT PARTS OF THE ONGOING WIND ADVISORY
WILL BE DROPPED EARLIER THAN 00Z IN A WEST TO EAST FASHION.
&&
.PREV DISCUSSION... /ISSUED 629 AM CDT THU MAR 27 2014/
AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
GUSTY SOUTH SFC WINDS WILL PREVAIL FOR MUCH OF THE DAY ALONG WITH
MVFR CIGS. A SURFACE DRY LINE WILL MOVE THROUGH THE ERN OK TAF
SITES THIS AFTERNOON...RESULTING IN A WIND SHIFT TO THE WEST
SOUTHWEST. THUNDERSTORM INITIATION EXPECTED ACROSS FAR ERN OK
LATER IN THE AFTERNOON. SCATTERED COVERAGE WOULD IMPACT THE AR TAF
SITES WITH VFR CIGS AND VSBYS FROM LATE AFTERNOON INTO THE
EVENING...AND WARRANTS A PROB30 GROUP AT THIS TIME. A COLD FRONT
WILL CATCH UP WITH THE DRY LINE THIS EVENING...RESULTING IN A
SHIFT TO THE NORTH ALONG WITH A MORE RELAXED GRADIENT.
PREV DISCUSSION... /ISSUED 422 AM CDT THU MAR 27 2014/
DISCUSSION...
A WINDY AND WARM DAY IS ON TAP TODAY AND A WIND ADVISORY WILL BE
POSTED FOR NORTHEAST OKLAHOMA AND THE NORTHWEST CORNER OF ARKANSAS
FROM NOW UNTIL 6 PM. PARTS OF THE ADVISORY AREA WILL LIKELY SEE
GUSTS DROP BELOW 40 MILES AN HOUR PRIOR TO THAT TIME AS THE
GRADIENT RELAXES SOME THIS AFTERNOON BUT NORTHWEST ARKANSAS MAY
SEE GUSTS NEAR 40 UNTIL 5-6 PM.
A FEW ELEVATED SHOWERS AND THUNDERSTORMS WILL BE POSSIBLE THIS
MORNING INTO EARLY AFTERNOON...ESPECIALLY IN THE EASTERN PART OF
THE FORECAST AREA. BY LATE AFTERNOON AND ESPECIALLY EARLY
EVENING...SURFACE BASED THUNDERSTORM DEVELOPMENT WILL BECOME
INCREASINGLY LIKELY ALONG THE DRYLINE AND THE COLD FRONT WHICH
WILL BE OVERTAKING THE DRYLINE THIS EVENING. A FEW OF THESE STORMS
MAY BE SEVERE WITH FAR EASTERN OKLAHOMA AND NORTHWEST ARKANSAS
MOST LIKELY TO BE IMPACTED.
AN ELEVATED FIRE DANGER WILL ALSO EXIST TODAY...BUT CONDITIONS
WILL LIKELY STAY BELOW RED FLAG CRITERIA. A FIRE DANGER STATEMENT
WILL BE ISSUED TO COVER THIS THREAT.
THE COLD FRONT WILL STALL FROM CENTRAL ARKANSAS INTO SOUTHEAST
OKLAHOMA AND AS AN UPPER LEVEL DISTURBANCE APPROACHES FROM THE
WEST...SHOWER AND THUNDERSTORM DEVELOPMENT WILL OCCUR AGAIN
FRIDAY. NORTHWEST ARKANSAS AND SOUTHEAST OKLAHOMA WILL BE MOST
IMPACTED...BUT THE ECMWF IS FURTHER WEST WITH CONVECTION AND SO
POPS ARE WARRANTED IN ALL AREAS.
THE WEEKEND WILL FEATURE DRY WEATHER WITH A WARMING TREND.
INCREASING SOUTHERLY WINDS WILL RESULT IN AN ELEVATED FIRE DANGER
AGAIN BY SUNDAY. THE NEXT COLD FRONT IS DUE TO MOVE ACROSS THE
AREA LATE MONDAY AND MONDAY NIGHT AND WILL LIKELY COME THROUGH
DRY. THIS FRONT WILL STALL NEAR THE RED RIVER BEFORE LIFTING BACK
NORTH AS A WARM FRONT LATE TUESDAY AND TUESDAY NIGHT.
ANOTHER COLD FRONT WILL MOVE ACROSS THE AREA LATE WEDNESDAY INTO
EARLY THURSDAY. LOW LEVEL MOISTURE WILL HAVE INCREASED ENOUGH BY
THAT TIME TO WARRANT A CHANCE OF SHOWERS AND THUNDERSTORMS WITH
THIS FRONT.
STAYED CLOSE TO GUIDANE TEMPERATURES FOR THE NEXT COUPLE DAYS
EXCEPT WENT A BIT COOLER THAN GUIDANCE IN SOME PLACES FOR HIGHS
FRIDAY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 7 PM THURSDAY FOR OKZ054-OKZ055-OKZ056-
OKZ057-OKZ058-OKZ059-OKZ060-OKZ061-OKZ062-OKZ063-OKZ064-
OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-OKZ070-OKZ071.
AR...WIND ADVISORY UNTIL 7 PM THURSDAY FOR ARZ001-ARZ002-ARZ010-
ARZ011.
&&
$$
SHORT TERM...22
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
905 AM CDT THU MAR 27 2014
.UPDATE...REST OF TODAY
GETTING A PERIOD OF FREEZING RAIN THIS MORNING DURING THE
TRANSITION FROM RAIN TO SNOW. REPORTS OF LIGHT ICE ACCUMS ON
ROADWAYS IN DAY COUNTY AND WEB CAMS ACROSS THE EAST REVEAL
FREEZING RAIN AS WELL. HAVE INSERTED FREEZING RAIN IN GRIDS AND
HAVE UPDATED AND EXPANDED WINTER WX ADVISORY TO INCLUDE MENTION OF
ICE ACCUMS. RAP BUFKIT SOUNDINGS INDICATE THIS FREEZING RAIN WILL
NOT LAST MUCH LONGER AT ALL AS COLUMN QUICKLY COOLS WITH STRONG
COLD AIR ADVECTION MOVING IN. SHOULD BE SWITCHING TO SNOW SHORTLY
AFTER 15Z FOR MOST LOCATIONS. ADJUSTED POPS TO BETTER FIT RADAR
RETURNS. STILL EXPECTING A BAND OF MODERATE SNOW ACCUMS ACROSS THE
SOUTHEAST COUNTIES WITH 3 TO 6 INCHES POSSIBLE BY THE END OF THE
DAY. UPDATES HAVE BEEN SENT.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TODAY THROUGH SATURDAY
CURRENT SURFACE ANALYSIS SHOWS TWO LOW PRESSURE CENTERS...ONE OVER
THE SOUTHERN NEBRASKA/NORTHWEST KANSAS BORDER...AND THE OTHER
CENTERED AROUND THE HURON AREA. AN INVERTED TROUGH EXTENDS THROUGH
NORTHEAST SOUTH DAKOTA AND INTO MINNESOTA. COMBINED WITH UPPER
LEVEL FORCING...PRECIPITATION HAS STARTED TO DEVELOP ACROSS
NORTHERN NEBRASKA AND SOUTHERN SOUTH DAKOTA THIS MORNING. KPIR HAS
REPORTED LIGHT RAIN FOR THE LAST HOUR. MODELS HAVE COME TOGETHER
INDICATING MODERATE TO STRONG 700 MB FRONTOGENESIS EXTENDING FROM
SOUTH CENTRAL SOUTH DAKOTA TO NORTHEAST SOUTH DAKOTA...AND IS
COUPLED WITH Q-VECTOR CONVERGENCE ACROSS THE EASTERN HALF THE CWA
THIS MORNING AND AFTERNOON. ALONG WITH STEEP LAPSE RATES...A
NARROW BAND OF SNOW IS EXPECTED TO DEVELOP ACROSS THE FAR EASTERN
CWA. STILL A LOT OF VARIABILITY IN THE FORECAST...AND THUS STILL
NOT OVERLY HIGH CONFIDENCE AT THIS TIME. FIRST MODELS SEEMS TO
HAVE SLOWED THE SYSTEM DOWN...SO ADJUSTED THE ADVISORY TIME BACK
JUST A FEW HOURS THIS MORNING. SECOND IS HOW QUICKLY RAIN WILL
TURN OVER TO SNOW...AND THIS WILL GREATLY INFLUENCE SNOW TOTALS.
THE CURRENT FORECAST HAS THIS TRANSITION OCCURRING BY MID TO LATE
MORNING ACROSS THE EASTERN CWA. SREF PLUMES SHOW A RANGE OF 0.5
INCHES OF SNOWFALL TO 12 INCHES OF SNOWFALL AT KATY. WHILE LOCALLY
HIGHER AMOUNTS ARE EXPECTED UNDER THE HEAVIEST BAND OF
SNOW...BASICALLY KEPT THE ADVISORY AREA IN THE 2 TO 6 INCH RANGE.
WINDS ARE ALSO A BIT OF A CONCERN THIS AFTERNOON. WEAK COLD AIR
ADVECTION WILL TAKE PLACE ON THE BACK SIDE OF THE LOW...AND MODELS
ARE BORDERING ON WIND ADVISORY CRITERIA...MAINLY IN THE HIGHER
ELEVATIONS OF THE PRAIRIE COTEAU. DECIDED TO FOCUS ON THE ADVISORY
AND DID NOT ISSUE ANY WIND HEADLINES...BUT SOMETHING TO MONITOR.
THIS SYSTEM EXITS THE REGION AND A HIGH PRESSURE RIDGE MOVES OVER
OUR CWA. ANOTHER COMPACT WAVE OF ENERGY MOVES ACROSS THE AREA
FRIDAY...BUT SOUNDINGS LOOK PRETTY DRY AT THIS POINT. BEST CHANCES
FOR LIGHT SNOWFALL WITH THIS SYSTEM LOOK TO REMAIN ACROSS THE
WESTERN DAKOTAS WHERE THE THERMAL GRADIENT WILL BE SET UP.
RETURN FLOW SETS UP AHEAD OF ANOTHER LOW PRESSURE SYSTEM SATURDAY.
THESE SOUTHERLY WINDS WILL TRANSPORT WARMER AIR INTO THE
REGION...AND HIGHS WILL REBOUND BACK TO ABOVE NORMAL
VALUES...ESPECIALLY ACROSS THE SOUTHWEST CWA.
.LONG TERM...SATURDAY NIGHT THROUGH WEDNESDAY
THE LONG TERM PERIOD STARTS OFF WITH LOW PRESSURE APPROACHING THE
AREA FROM THE WEST. THE COLD FRONT ASSOCIATED WITH THIS SYSTEM
LOOKS TO DROP ACROSS THE AREA SOMETIME SUNDAY EVENING...WITH THE
POSSIBILITY OF SOME RAIN OVER THE AREA DURING THE DAY...THEN
SWITCHING OVER TO SNOW SUNDAY NIGHT AS COLDER AIR MOVES IN BEHIND
THE FRONT. THE MODELS ARE IN DECENT AGREEMENT WITH THIS
SYSTEM...WITH JUST SOME DIFFERENCES IN THE STRENGTH. BOTH THE GFS
AND ECMWF CURRENTLY INDICATE SIGNIFICANT SNOW ACCUMULATIONS LATE
SUNDAY NIGHT INTO THE DAY MONDAY...WITH THE POTENTIAL FOR PRETTY
STRONG WINDS AIDING IN CREATING POTENTIAL BLIZZARD CONDITIONS.
OBVIOUSLY...THIS IS SUBJECT TO CHANGE WITH FUTURE MODEL RUNS.
THIS SYSTEM PUSHES EAST OF THE AREA MONDAY NIGHT WITH HIGH
PRESSURE DROPPING OVER THE REGION...KEEPING TEMPERATURES WELL
BELOW NORMAL.
ANOTHER SYSTEM LOOKS TO AFFECT THE AREA TUESDAY NIGHT INTO
WEDNESDAY...BUT THERE IS MUCH MORE DISAGREEMENT IN THE TRACK AND
TIMING OF THIS SYSTEM. THEREFORE...WILL STICK FAIRLY CLOSE TO
ALLBLEND POPS FOR NOW. TEMPERATURES DO LOOK TO BE COOL ENOUGH FOR
PRECIPITATION WITH THIS SYSTEM TO BE SNOW.
TEMPERATURES WILL BE ABOVE NORMAL ON SUNDAY AS WAA REMAINS IN
PLACE AHEAD OF THE APPROACHING LOW. 50S TO LOWER 60S WILL BE
COMMON FOR HIGHS. THE COLDER AIR THEN MOVES IN...WITH HIGHS MAINLY
IN THE LOWER TO MID 30S MONDAY THROUGH WEDNESDAY.
&&
.AVIATION...
12Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
A STORM SYSTEM WILL SPREAD PRECIPITATION OVER THE EASTERN PORTION
OF THE CWA TODAY. VFR/MVFR CIGS WILL BE COMMON DURING THE
DAY...WITH VFR CIGS EXPECTED OVERNIGHT. THE LOWEST VISIBILITY DUE
TO SNOW WILL OCCUR ACROSS THE SOUTHEASTERN CWA...POSSIBLY
INCLUDING KATY LATE THIS MORNING AND THIS AFTERNOON. THE
PRECIPITATION WILL COME TO AN END DURING THE EARLY EVENING HOURS.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 6 PM CDT THIS EVENING FOR CLARK-
CODINGTON-DAY-DEUEL-GRANT-HAMLIN-ROBERTS.
MN...WINTER WEATHER ADVISORY UNTIL 6 PM CDT THIS EVENING FOR BIG
STONE-TRAVERSE.
&&
$$
UPDATE...TMT
SHORT TERM...SERR
LONG TERM...PARKIN
AVIATION...PARKIN
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS NASHVILLE TN
1132 PM CDT WED MAR 26 2014
.UPDATE...FOR 06Z AVIATION DISCUSSION.
&&
.AVIATION...06Z AVIATION DISCUSSION.
VFR CONDITIONS THRU 28/06Z. EXPECT PROGRESSION TO OVC AC 27/09Z W-
27/12Z E WITH SCT/BKN CU/TCU 27/15Z W-27/24Z. SOME INDICATION OF
ENOUGH MOISTURE/INSTABILITY FOR VCSH CKV 27/20Z-28/00Z...BUT BEST
MOISTURE/INSTABILITY SHOULD BE AROUND OR AFTER 28/02Z CKV/BNA WITH
SHWRS/POSSIBLE TSTMS CKV...BECOMING PREVALENT. STRONG SFC PRESSURE
GRADIENT FROM 27/09Z-28/06Z. 20-30KT GUSTS FROM 27/09Z W-28/00Z E
PER PRESSURE GRADIENT STRENGTHENING...35KTS AFTERWARDS THRU 28/06Z.
INCREASING STRONG LOWER LEVEL JET DYNAMICS EXPECTED...LLWS 27/20Z
W-28/00Z E THRU 28/06Z WITH GUSTS TO 60KT POSSIBLE.
&&
.PREV DISCUSSION.../ISSUED 1005 PM CDT WED MAR 26 2014/
UPDATE...
TEMPERATURES ACROSS THE AREA THIS EVENING ARE GENERALLY IN THE MID
30S TO LOWER 40S. SCT TO BKN MID/HIGH CLOUD COVER NOW IN PLACE AND
SHOULD CONTINUE TO INCREASE...ESPECIALLY TOWARD SUNRISE. MODELS IN
AGREEMENT WITH STRONG WAA AT THE 850 MB LEVEL AND WE ALSO SEE SOME
LIGHT PRECIP RETURN FROM BOTH THE HRRR AND THE GFS. HOWEVER...CURRENT
SFC ANALYSIS AND THE EXPECTED TIME HEIGHT RH FIELDS AT
12Z...SUGGEST THAT THE AIRMASS IN PLACE WILL BE MUCH TOO DRY TO
SUPPORT ANY PRECIP REACHING THE SFC. THEREFORE...WILL KEEP GRIDS
AS IS.
06Z TO 12Z TEMP PROGRESSIONS DO TREND SLIGHTLY UPWARD THROUGH THAT
TIME-FRAME. THUS...CURRENT TEMPS ARE NOT EXPECTED TO DROP THAT MUCH
FURTHER TONIGHT BEFORE LEVELING OFF.
NO UPDATE FOR NOW AS CURRENT FCST APPEARS TO BE ON TRACK.
PREV DISCUSSION... /ISSUED 658 PM CDT WED MAR 26 2014/
UPDATE...FOR 00Z AVIATION DISCUSSION.
AVIATION...00Z AVIATION DISCUSSION.
VFR CONDITIONS EXPECTED THRU 27/24Z. EXPECT PROGRESSION TO OVC AC
27/09Z W-27/12Z E WITH SCT/BKN CU/TCU POSSIBLE 27/15Z W-27/24Z.
SOME INDICATION OF ENOUGH MOISTURE/ATM INSTABILITY FOR VCSH CKV
27/20Z-27/24Z. STRONG SFC PRESSURE GRADIENT EXPECTED TO DEVELOP FROM
AROUND 27/09Z-27/24Z. GUSTS TO 35KTS POSSIBLE GENERALLY AFTER 27/18Z...
PROGRESSION GUST FORECAST 25KTS/30KTS FROM 27/09Z-27/18Z. WITH STRONG
LOWER LEVEL JET DYNAMICS EXPECTED ALSO...LLWS CKV/BNA AROUND 27/20Z
WITH GUSTS TO 60KT POSSIBLE.
PREV DISCUSSION.../ISSUED 437 PM CDT WED MAR 26 2014/
UPDATE...
SAT IMAGERY SHOWING THE EXTENSIVE CLOUD COVER IS STILL WEST OF THE
MS RIVER. WILL GO AHEAD AND MODIFY THE SKY GRIDS AND DELAY THE
ONSET OF MOSTLY CLOUDY SKIES UNTIL LATER TONIGHT. WILL THEN RERUN
GRIDS AND SEND PRODUCTS.
PREV DISCUSSION.../ISSUED 240 PM CDT WED MAR 26 2014/
DISCUSSION...
NOTHING BUT BLUE SKIES ACROSS THE AREA THIS AFTERNOON AS NEXT
SYSTEM CRANKS UP IN THE SOUTHERN PLAINS AS MOISTURE IS ALREADY
RETURNING ON BACKSIDE OF SURFACE RIDGE THAT STRETCHES FROM OHIO
DOWN THROUGH THE TENNESSEE VALLEY INTO THE NORTHERN GULF OF
MEXICO. SOUTHERN BRANCH OF THE POLAR JET IS ALSO RACING ACROSS
NORTHERN MEXICO AND ALONG GULF REGION SPILLING MOISTURE OUT INTO
THE SOUTHERN PLAINS. UPPER TROUGH MOVING THROUGH THE ROCKIES HAS
DEVELOPED A LEE SIDE LOW OUT IN THE CENTRAL AND SOUTHERN PLAINS.
SURFACE PRESSURE GRADIENT WILL BEGIN TO TIGHTEN UP TONIGHT AND AS
SYSTEM SHIFTS EASTWARD ON THURSDAY I EXPECT WE WILL HAVE WINDY
CONDITIONS ACROSS THE MID STATE DURING THE DAY AND INTO THURSDAY
NIGHT. I`VE ISSUED A WIND ADVISORY FOR ALL OF MIDDLE TENNESSEE
FOR THIS PERIOD. TEMPS WILL WARM INTO THE LOWER 60S MOST AREAS ON
THURSDAY AND I THINK SHOWERS WILL HOLD OFF FOR THE MOST PART UNTIL
THURSDAY NIGHT. COULD SEE SOME SCATTERED SHOWERS ALONG THE
TENNESSEE RIVER DURING THE AFTERNOON. SHOWERS AND THUNDERSTORMS
LOOK LIKELY THURSDAY NIGHT WITH SHOWERS AND A FEW THUNDERSTORMS ON
FRIDAY BEHIND THE FRONT. A WAVE DEVELOPS ON THE FRONT DURING THE
DAY FRIDAY AND RIDES UP THE FRONT BRINGING SHOWERS AND THUNDERSTORMS
FRIDAY NIGHT WITH THE POTENTIAL FOR A SEVERE THREAT MAINLY ACROSS
SOUTH HALF WHERE THE MOST UNSTABLE CAPES AND NEGATIVE LI`S OCCUR.
DAMAGING WINDS APPEAR TO BE THE MAIN THREAT AT THIS TIME. SURFACE
FRONT PULLS EAST ON SATURDAY WITH LINGERING SHOWERS AND COOLER
TEMPS. PACIFIC AIR MASS MOVES IN SUNDAY THROUGH MID WEEK SO TEMPS
WILL BE AT OR SOMEWHAT ABOVE CLIMATOLOGY FOR THIS TIME OF THE
YEAR. NEXT SIGNIFICANT RAIN MAKER WILL MOVE IN WEDNESDAY NIGHT AND
THURSDAY.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THURSDAY TO 4 AM CDT FRIDAY FOR
TNZ005>011-023>034-056>066-075-077>080-093>095.
&&
$$
31
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
903 PM CDT FRI MAR 28 2014
.UPDATE...
HAVE REMOVED SEVERE THUNDERSTORM WATCHES FROM MOST SOUTHEAST TEXAS
COUNTIES. LINE HAS WEAKENED SIGNIFICANTLY OVER THE LAST HOUR AND
THUNDERSTORMS SHOULD END OR MOVE EAST OF THE REGION WITHIN THE
NEXT HOUR OR SO. MUCH DRIER AIR FILTERING INTO THE REGION IN THE
WAKE OF THIS SYSTEM HAS LED TO RAPIDLY IMPROVING CONDITIONS INLAND
WITH CLEAR SKIES ACROSS THE NORTHERN HALF OF THE REGION. SEA FOG
ALONG THE COAST WILL END LATER TONIGHT AS THE FRONTAL BOUNDARY
MOVES OFFSHORE. 38
&&
.PREV DISCUSSION... /ISSUED 721 PM CDT FRI MAR 28 2014/
DISCUSSION...
PLEASE SEE 00Z AVN DISCUSSION
AVIATION...
A LINE OF STRONG THUNDERSTORMS IS RAPIDLY MOVING IN TO THE HOUSTON
METRO AREA AND WILL BE AFFECTING IAH...HOU...AND SGR BETWEEN 00-02Z.
THESE STORMS SHOULD BE CLEAR OF THE METRO AREA BY BY 03Z.
A COLD FRONT WILL MOVE OVER NORTHERN PORTIONS OF THE CWA BY LATE
EVENING AND PROGRESSIVELY MAKE ITS WAY TO THE COAST BEFORE
SUNRISE. AVIATION CONDITIONS WILL RAPIDLY IMPROVE BEHIND THE
FRONT. 44
PREV DISCUSSION... /ISSUED 521 PM CDT FRI MAR 28 2014/
UPDATE...
QUICK UPDATE TO ADD MENTION OF SEVERE THUNDERSTORM WATCH 39 WHICH
WILL INCLUDE THE HOUSTON METRO AREA THIS EVENING. 38
PREV DISCUSSION... /ISSUED 328 PM CDT FRI MAR 28 2014/
DISCUSSION...
AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A
WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD
LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND.
CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE
REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP
BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE
TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP.
CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD
HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE
RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION
MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE
MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND
AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE
POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH.
DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT
TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL
PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL
COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT
TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER
TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL
FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL
DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF
SUNSHINE.
CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF
THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS
PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL
SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND
CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT
WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES
WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW
SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH
THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY.
43
MARINE...
DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE
DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE
SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT
THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY
THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL
MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY
MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL
NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO
SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15
KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15-
20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM
WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY
SUNDAY NIGHT. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0
HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0
GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CDT SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM 7 AM CDT SATURDAY
THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...38
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
721 PM CDT FRI MAR 28 2014
.DISCUSSION...
PLEASE SEE 00Z AVN DICUSSION
&&
.AVIATION...
A LINE OF STRONG THUNDERSTORMS IS RAPIDLY MOVING IN TO THE HOUSTON
METRO AREA AND WILL BE AFFECTING IAH...HOU...AND SGR BETWEEN 00-02Z.
THESE STORMS SHOULD BE CLEAR OF THE METRO AREA BY BY 03Z.
A COLD FRONT WILL MORVE NORTHERN PORTION NORTHERNS OF THE CWA BY
LATE EVENING AND PROGRESSIVELY MAKE ITS WAY TO THE COAST BEFORE
SUNRISE. AVIATION CONDITIONS WILL RAPIDLY IMPROVE BEHIND THE
FRONT. 44
&&
.PREV DISCUSSION... /ISSUED 521 PM CDT FRI MAR 28 2014/
UPDATE...
QUICK UPDATE TO ADD MENTION OF SEVERE THUNDERSTORM WATCH 39 WHICH
WILL INCLUDE THE HOUSTON METRO AREA THIS EVENING. 38
PREV DISCUSSION... /ISSUED 328 PM CDT FRI MAR 28 2014/
DISCUSSION...
AT 2 PM...A WEAK SURFACE LOW WAS LOCATED OVER CENTRAL TEXAS WITH A
WARM FRONT TO THE NORTHEAST...A DRY LINE EXTENDING SOUTH TOWARD
LAREDO AND A COLD FRONT EXTENDING WEST TOWARD THE BIG BEND.
CONVECTION HAS FIRED IN CENTRAL TEXAS THIS AFTERNOON BUT COVERAGE
REMAINS LIMITED. A SOUNDING FROM TEXAS A&M SHOWS A DECENT CAP
BETWEEN 900-800 MB AND CONSIDERABLE DRY AIR AT 800 MB. LOOKS LIKE
TEMPS WILL NEED TO WARM TO AROUND 86 DEGREES TO BREAK THE CAP.
CONVECTION OVER CENTRAL TEXAS WILL CONTINUE TO PUSH EAST AND COULD
HOLD TOGETHER AND MOVE ACROSS THE NORTHERN THIRD OF SE TX. THE
RAP...TEXAS TECH WRF AND HRRR ALL ARE SUPPORTIVE OF CONVECTION
MOVING ACROSS THE NORTH PART OF SE TX THIS EVENING BUT ALL THREE
MODELS HAVE BEEN TOO AGGRESSIVE WITH RAIN CHANCES YESTERDAY AND
AGAIN TODAY. WILL GO WITH LIKELY POPS OVER THE NORTH AND CHANCE
POPS CENTRAL. WILL MENTION SOME STORMS SEVERE OVER THE NORTH.
DENSE SEA FOG CONTINUES ALONG THE COAST. WEB CAMS AND SFC OBS CONT
TO SHOW DENSE SEA FOG IMPINGING ON THE COAST AND OFFSHORE. WILL
PROBABLY NEED A DENSE FOG ADVISORY TONIGHT FOR THE COASTAL
COUNTIES THROUGH 06Z. THE RAP AND GFS ARE FASTER WITH A COLD FRONT
TONIGHT AND IT APPEARS THAT THE FRONT WILL CLEAR THE COAST CLOSER
TO 06Z THAN 12Z SAT. ONCE WINDS GO OFFSHORE...DRIER AIR WILL
FILTER IN AND THE FOG WILL BEGIN TO DISSIPATE. HIGH PRESSURE WILL
DOMINATE SATURDAY AND SUNDAY WITH SEASONAL TEMPS AND PLENTY OF
SUNSHINE.
CLOUDS WILL RETURN LATE SUNDAY NIGHT AND PERSIST THROUGH MUCH OF
THE WEEK AHEAD AS HIGH PRESSURE DRIFTS EAST AND ONSHORE WINDS
PREVAIL. FCST SOUNDINGS SHOW SATURATION BENEATH A CAP SO FEEL
SOME STREAMER SHOWERS WILL BE POSSIBLE STARTING TUESDAY AND
CONTINUING THROUGH FRIDAY. TEMPERATURES WILL ALSO BE MILDER NEXT
WEEK WITH HIGHS NEAR 80 AND LOWS IN THE MID 60S. SOME DIFFERENCES
WITH REGARD TO TIMING OF DISTURBANCES EMBEDDED IN THE UPPER FLOW
SO WILL KEEP RAIN CHANCES ON THE LOW SIDE FOR NOW. GFS/ECMWF WITH
THE TIMING OF THE NEXT COLD FRONT EITHER NEXT FRIDAY OR SATURDAY.
43
MARINE...
DENSE SEA FOG TO BE THE MAIN ISSUE TONIGHT AS THE NEARSHORE DENSE
DECK CREEPS BACK ONTO THE COAST IN THE COMING HOURS. ANOTHER DENSE
SEA FOG ADVISORY LIKELY IN THE HOURS LEADING UP TO THE COLD FRONT
THAT IS TIMED TO REACH THE SHORELINE AROUND MIDNIGHT...OR SHORTLY
THEREAFTER. THIS FRONTAL PASSAGE WILL SCOUR OUT THE LOWER LEVEL
MOISTURE AND RESIDENT FOG AND CLEAR SKIES THROUGH EARLY SATURDAY
MORNING. LIGHT RAIN OR DRIZZLE WILL ACCOMPANY THIS FOG. POST-FRONTAL
NORTHERLIES OVER THE FAR OFFSHORE WATERS WILL LIKELY INCREASE TO
SCEC CRITERIA FOR A SHORT WHILE SATURDAY MORNING...GENERALLY 15
KNOTS OR LESS OVER THE BAYS AND NEARSHORE WATERS WITH OCCASIONAL 15-
20KT GUSTS OVER A SLIGHT CHOP. AS HIGH PRESSURE MOVES ACROSS FROM
WEST-TO-EAST...LIGHT EASTERLIES WILL SLOWLY VEER SOUTHEASTERLY BY
SUNDAY NIGHT. 31
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 52 78 49 76 53 / 60 10 10 10 0
HOUSTON (IAH) 58 79 52 77 55 / 40 10 10 10 0
GALVESTON (GLS) 64 74 59 73 60 / 20 10 10 10 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 4 AM CDT SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM SATURDAY MORNING
THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES: WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60
NM...WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT
20 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...38
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
357 PM CDT THU MAR 27 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
AT 3 PM...A 992 MB SURFACE LOW WAS CENTERED OF THE SOUTHWEST
CORNER OF IOWA. THE LATEST MSAS SHOWS 3 HOUR HEIGHT FALLS OF 3
MILLIBARS ACROSS EASTERN IOWA...SOUTHERN WISCONSIN...AND NORTHERN
ILLINOIS. AS RESULT...EXPECT THE LOW TO CONTINUE TO TRACK
NORTHEAST ACROSS IOWA LATE THIS AFTERNOON AND EARLY EARLY EVENING.
MODERATE TO STRONG 850 MB MOISTURE TRANSPORT MOVES INTO NORTHEAST
IOWA...AND SOUTHWEST AND CENTRAL WISCONSIN BETWEEN 27.21Z AND
28.03Z. DUE TO THIS...INCREASED THE PRECIPITATION TOTALS INTO THE
0.35 TO 0.75 INCH RANGE.
IN ADDITION TO THIS...THE MOST UNSTABLE CAPES CLIMB UP TO
300 J/KG ACROSS PARTS OF NORTHEAST IOWA...SOUTHEAST
MINNESOTA...AND SOUTHWEST AND CENTRAL WISCONSIN. THERE HAS ALREADY
BEEN A FEW ISOLATED REPORTS OF LIGHTNING ALONG AND SOUTH OF
INTERSTATE 90 THIS AFTERNOON. WITH THE CAPES A BIT FURTHER NORTH
AND WEST...EXPANDED THE CHANCE OF THUNDERSTORMS MORE INTO
NORTHEAST IOWA...SOUTHEAST MINNESOTA...AND AS FAR AS NORTH OF
INTERSTATE 90 CORRIDOR THROUGH 28.03Z. WITH THE 0-3 KM AND 0-6 KM
SHEAR LESS THAN 30 KNOTS...NOT EXPECTING ANYTHING SEVERE.
MEANWHILE ACROSS SOUTHEAST MINNESOTA AND NORTH CENTRAL
WISCONSIN...COLD AIR ADVECTION DEVELOPS ACROSS SOUTHEAST
MINNESOTA AND NORTH CENTRAL WISCONSIN. THE NAM IS THE STRONGEST
AND FASTEST WITH THIS COLD AIR ADVECTION. AS A RESULT...IT
PRODUCES MUCH MORE SNOW ACROSS SOUTHEAST MINNESOTA /UP TO 2.5
INCHES IN COBB/ TONIGHT. HOWEVER THE 18Z AMDAR SOUNDINGS SHOW THAT
IT IS A BIT TOO COLD AND MUCH CLOSER TO THE RAP AND GFS. AS A
RESULT...TRENDED THE SWITCH OVER FROM RAIN TO SNOW A BIT LATER
THAN PREVIOUSLY FORECAST. IT LOOKS LIKE THIS WILL OCCUR...NORTH
OF INTERSTATE 94 BETWEEN 27.21Z AND 28.00Z...WEST OF MISSISSIPPI
RIVER BETWEEN 28.00Z AND 28.03Z...AND ACROSS THE REMAINDER OF THE
AREA BETWEEN 28.04Z AND 28.08Z. SOUTHEAST MINNESOTA WILL SEE UP TO
AN INCH...AND AROUND 3 INCHES NORTH OF WISCONSIN 29 IN NORTH
CENTRAL WISCONSIN. ELSEWHERE VERY LITTLE...IF ANY...SNOW IS
EXPECTED.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 355 PM CDT THU MAR 27 2014
ON SUNDAY...A TIGHT PRESSURE GRADIENT DEVELOPS ALONG AND SOUTH OF
THE INTERSTATE 90 CORRIDOR AHEAD OF A DEEPENING LOW OVER THE
NORTHERN PLAINS. THIS TIGHT PRESSURE GRADIENT WILL ALLOW THE
SUSTAINED SOUTH WINDS TO CLIMB INTO THE 15 TO 25 KNOT RANGE AND
THE WINDS WILL GUST UP TO 35 MPH. AT THE SAME...THE 850 MB
TEMPERATURES WILL CLIMB INTO THE 10 TO 14C RANGE ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA. BUFKIT SOUNDING SHOW THAT WE
WILL NOT QUITE MIX UP TO THIS LEVEL...BUT WE WILL MIX UP INTO THE
900 TO 875 MB LAYER...AND THIS WILL ALLOW TEMPERATURES TO CLIMB
INTO THE LOW AND MID 50S NORTH OF INTERSTATE 94...AND AROUND 60
ACROSS THE REMAINDER OF THE AREA.
FROM SUNDAY NIGHT INTO MONDAY NIGHT...THE MODELS CONTINUE TO SHOW
THAT A NEGATIVELY TILTED SHORT WAVE TROUGH WILL MOVE THROUGH THE
FORECAST AREA. TEMPERATURES ALOFT ARE WARM ENOUGH THAT MUCH OF THE
PRECIPITATION WILL FALL MAINLY IN THE FORM OF RAIN. WHILE THE
0-6 KM SHEAR ARE GREATER THAN 35 KNOTS...THERE IS VERY LITTLE
CAPE ACROSS THE REGION...SO THERE IS NOT ANY THREAT FOR ANY SEVERE
WEATHER.
BEYOND THIS TIME PERIOD...THE 27.00Z MODELS HAVE DIFFERING
OPINIONS ON HOW FAR NORTH A LOW WILL TRACK THROUGH NORTHERN AND
MID MISSISSIPPI RIVER VALLEY. THE ECMWF IS MUCH FURTHER NORTH THAN
THE GFS. WITH SUCH DIVERSE SOLUTIONS...JUST STAYED WITH THE MODEL
CONSENSUS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1251 PM CDT THU MAR 27 2014
WIDESPREAD IFR/LIFR CLOUD AND VSBY CONDITIONS CURRENTLY ENGULFING
THE UPPER MISSISSIPPI RIVER AS A STRONG LOW PRESSURE SYSTEM WAS
LIFTING OUT OF THE CENTRAL PLAINS. AREAS OF DRIZZLE AND SCATTERED
SHOWER ACTIVITY WAS ALSO LIFTING NORTHEAST ACROSS THE REGION
AHEAD OF THE APPROACHING STORM SYSTEM. LOOK FOR THE LOW PRESSURE
SYSTEM TO CONTINUE LIFTING NORTHEAST INTO SOUTHERN WI THIS
EVENING... SWITCHING THE WINDS TO THE NORTH AND ALLOWING COLDER
AIR TO FILTER IN THIS EVENING. THIS WILL LIKELY CAUSE A
TRANSITION FROM RAIN TO SNOW AT KRST BY 01Z...LASTING THROUGH
AROUND MIDNIGHT....THEN SHUTTING OFF. 1/2 TO 1 INCH OF
ACCUMULATION IS POSSIBLE. KLSE LOOKS WARM ENOUGH TO MAINTAIN RAIN
BEFORE SHUTTING OFF AROUND 06Z. OTHERWISE...LOOK FOR BRISK
NORTH/NORTHWEST WINDS DEVELOPING THIS EVENING...LASTING THROUGH
EARLY FRIDAY MORNING WITH LOW CLOUDS EXPECTED TO SCATTER OUT IN
THE 10-11Z TIME FRAME.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
340 AM CDT THU MAR 27 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CDT THU MAR 27 2014
MAIN FORECAST CONCERNS THIS PACKAGE...PRECIP TYPES/AMOUNTS/CHANCES
TODAY/TONIGHT.
DATA ANALYSIS AT 06Z HAD ONE AREA OF LOW PRESSURE OVER EASTERN SD
AND ANOTHER NEAR THE NEB/CO/KS BORDER...WITH THE STRONGER PRESSURE
FALLS AHEAD OF THESE FEATURES FROM LK SUPERIOR TO NORTHEAST KS. WV
IMAGERY SHOWED SOUTHERN STREAM SHORTWAVE ENERGY LIFTING NORTHEAST
ACROSS NORTHERN MO WITH A BROAD AREA OF -RA/RA LIFTING NORTHEAST
WITH IT. FURTHER NORTH...WARM ADVECTION/ISENTROPIC LIFT -SN/PL
LIMITED TO EAST CENTRAL WI. CLOUDS CONTINUING TO THICKEN OVER THE
AREA AS GULF OF MEX MOISTURE ARRIVES. THE CLOUDS PLUS THE GRADIENT
SOUTH WINDS KEEPING EARLY MORNING TEMPS NEAR/ABOVE NORMAL FOR A
CHANGE.
NO PROBLEMS NOTED WITH 27.00Z MODEL INITIALIZATIONS. GFS A BIT HIGH
WITH SFC DEW POINTS IN THE PLUME OF MOISTURE COMING NORTH THRU THE
PLAINS BUT DOES NOT LOOK TO IMPACT ITS SOLUTION TODAY/TONIGHT.
SOLUTIONS CONTINUE TO OFFER A TIGHTENING CONSENSUS ON THE STRONGER
SFC LOW THRU MID LEVEL TROUGH TO MOVE INTO/ACROSS THE AREA TODAY/
TONIGHT...WITH TREND FAVORING STRONGER OF EARLIER RUNS ON THE MID
LEVEL TROUGH. CHECK OF OBS VS. MODEL DATA AT 06Z SHOWED ALL TO BE
QUITE GOOD WITH THE SD AND NEB/CO/KS LOWS. PER WV IMAGERY...ECMWF
LOOKED BEST WITH THE MO/SOUTHERN IA SHORTWAVE ENERGY WITH A MODEL
COMPROMISE LOOKING GOOD WITH THE WESTERN CONUS/EASTERN PAC SHORTWAVE
DETAILS. MODEL CONSENSUS WITH A DECENT HANDLE ON THE 00-06Z PRECIP
ACROSS THE CENTRAL/ WESTERN CONUS. NO ONE MODEL FAVORITE AND SIDED
WITH THE RATHER TIGHT MODEL/ENSEMBLE CONSENSUS. SHORT-TERM FCST
CONFIDENCE IS GOOD THIS CYCLE.
IN THE SHORT TERM...APPEARS SHORTWAVE ENERGY AND BROAD AREA OF -RA/
RA WITH IT WILL GRAZE THE SOUTHEAST END OF THE FCST AREA BEFORE
SUNRISE THIS MORNING THEN BE EAST OF THE AREA AFTER 12Z. WEAKER 925-
850MB WARM ADVECTION CONTINUES THIS MORNING WITH TEMPS AT THESE
LEVELS ABOVE 0C OVER ALL BUT THE FAR NORTH END OF THE FCST AREA.
THIS ALONG WITH THE SFC/BOUNDARY LAYER TEMPS IN THE MID 30S-LOWER
40S TO KEEP BULK OF PRECIP THRU THE MID-DAY HOURS AS LIQUID. LIFT
SIGNAL WEAKER THIS MORNING...WITH MOISTURE/SATURATION GENERALLY
BELOW 700MB AND CLOUD TOP TEMPS AROUND -5C. LOWERED SOME OF THE
PRECIP CHANCES EARLY THIS MORNING AND ADDED MENTION OF -DZ AS CLOUD
DECKS CONTINUE TO THICKEN/LOWER AHEAD OF APPROACHING SFC-850MB LOW.
STRONGER/DEEPEST OF THE LIFT/UPWARD MOTION MOVES EAST ACROSS THE
AREA THIS AFTERNOON/EARLY THIS EVENING WITH THE SFC-MID LEVEL TROUGH
AXIS. WITH THE WARM BOUNDARY LAYER...GENERALLY RAIN EXPECTED BUT IT
WILL BE CLOSE FOR -RA/-SN ACROSS TAYLOR CO. WI. PRECIP CHANCES
NEAR/AT 100 PERCENT LOOK GOOD THIS AFTERNOON. LEFT A SMALL -TSRA
CHANCE ACROSS THE FAR SOUTHEAST END OF THE FCST AREA...NEAR/SOUTH OF
THE EXPECTED SFC LOW TRACK. WITH PASSAGE OF THE 925-850MB LOW THIS
AFTERNOON...LOW LEVEL COLD ADVECTION BEHIND IT THE COLUMN COOLS
ENOUGH TO SUPPORT SNOW OVER THE NORTHWEST END OF THE FCST AREA LATE
THIS AFTERNOON INTO THIS EVENING. SNOW POTENTIAL LATE THIS
AFTERNOON/EARLY THIS EVENING WILL DEPEND ON THE DEPTH OF MOISTURE
AND IF CLOUD TOPS ARE COLD ENOUGH TO CONTAIN ICE CRYSTALS. MODEL
CONSENSUS INDICATES THERE WILL BE A SHORT 1 TO 2 HR PERIOD WHERE THE
BACK EDGE OF THE LIFT AND DEEPER MOISTURE OVERLAP WITH THE COLUMN
COLD ENOUGH FOR SNOW. ADDED A BIT MORE SNOW TO THE FCST GRIDS FOR
THE NORTHWEST HALF OF THE FCST AREA INTO THIS EVENING. MOISTURE/
LIFT EXIT RATHER QUICKLY TONIGHT...WITH PRECIP CHANCES TAPERING OFF
AND OUT OF THE AREA BY LATE TONIGHT/FRI MORNING. PRECIP CHANCES
TONIGHT ALREADY WELL TRENDED IN THE FCST GRIDS. USED THE MODEL/
ENSEMBLE CONSENSUS FOR HIGHS/LOWS TODAY/TONIGHT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 340 AM CDT THU MAR 27 2014
MAIN FORECAST CONCERNS FOR FRI THROUGH SAT NIGHT...CLOUD AND
TEMPERATURE TRENDS.
27.00Z MODELS IN REASONABLE AGREEMENT FOR THE FRI-SAT NIGHT PERIOD
WITH THE BIGGER PICTURE SHOWING GRADUALLY RISING HGTS ACROSS THE
NORTH-CENTRAL CONUS...AHEAD OF STRONGER TROUGHING MOVING INTO THE
WESTERN CONUS. SOME DETAIL DIFFERENCES WITH A SHORTWAVE TO PASS
GENERALLY SOUTH OF THE AREA FRI NIGHT...BUT IMPROVING CONSENSUS THAT
THE BULK OF THIS ENERGY WILL PASS ACROSS THE MID MS VALLEY WITH THE
SFC WAVE/LOW WELL SOUTH IN THE TN/KY AREA. FCST CONFIDENCE IS GOOD
FOR FRI THU SAT...FOR WHAT IS TRENDING TO BE A DRY/QUIET PERIOD.
WEAK SHORTWAVE RIDGING BUILDS ACROSS THE UPPER MIDWEST FRI AS THE
NEXT RIDGE OF CAN HIGH PRESSURE BUILDS IN. BIGGEST QUESTION FRI IS
CLOUDS. MODEL CONSENSUS INDICATES PLENTY OF 925MB MOISTURE TO REMAIN
OVER THE REGION ON FRI. WILL REMAIN OPTIMISTIC FOR AT LEAST PARTLY
CLOUDY SKIES FRI WITH RATHER DEEP ANTICYCLONIC FLOW SPREADING INTO
MN/IA/WI. LOW LEVEL COLD ADVECTION SENDS TEMPERATURES BACK BELOW
NORMAL FOR FRI/FRI NIGHT. 925MB TEMPS IN THE 0C TO -6C RANGE AT 00Z
SAT AND -3C TO -8C RANGE AT 12Z SAT. SHORTWAVE TROUGH PASSING ACROSS
THE MID MS VALLEY SPREADS SOME MID/HIGH LEVEL MOISTURE ACROSS THE
AREA FRI NIGHT. MOST OF THE FORCING/LIFT GOES INTO TRYING TO
SATURATE THE COLUMN OVER THE DRIER/COLDER CAN HIGH. BY THE TIME ANY
DEEPER SATURATION OCCURS THE LIFT HAS PUSHED EAST OF THE AREA.
CONTINUED THE MOSTLY CLOUDY TREND FOR FRI NIGHT BUT LEFT FCST DRY.
RIDGE BUILDING/RISING HGTS BEGIN IN EARNEST SAT AND CONTINUE SAT
NIGHT. MDT/STRONG 925-700MB WARM ADVECTION SPREADS ACROSS THE AREA
SAT/SAT NIGHT WITH 925MB TEMPS IN THE 0C TO +6C RANGE BY 12Z SUN...
WITH THE LOW LEVEL WARM ADVECTION CONTINUING. SOURCE REGION OF THE
SFC-700MB AIRMASS SAT/SAT NIGHT IS THE CENTRAL/SOUTHERN PLAINS WITH
THE FCST REMAINING DRY UNDER PARTLY CLOUDY/MOSTLY SUNNY SKIES. AFTER
A COLDER DAY FRI...TEMPS BACK TO NEAR NORMAL FOR SAT. USED A BLEND
OF THE GUIDANCE HIGHS/LOWS FOR FRI THRU SAT NIGHT.
FOR SUNDAY THROUGH WEDNESDAY.../DAYS 4 TO 7/...
FORECAST CONCERNS THIS PERIOD...MUCH ABOVE NORMAL HIGHS SUN...NEXT
SYSTEMS TIMED TO IMPACT THE AREA MON AND WED.
27.00Z MEDIUM RANGE MODELS IN RATHER GOOD AGREEMENT SUN/MON WITH THE
SFC THRU MID LEVEL RIDGE TO MOVE EAST OF THE AREA SUN AND THE NEXT
TROUGH TO MOVE INTO THE MID/UPPER MS VALLEY MON. REASONABLE
CONSENSUS CONTINUES TUE/WED FOR A PROGRESSIVE PATTERN ACROSS THE
CONUS. SHORTWAVE RIDGING BUILDS IN FOR TUE THEN THE NEXT TROUGH
MOVES INTO THE CENTRAL CONUS FOR WED. SOME TIMING DIFFERENCES BY WED
WHICH IS NOT SURPRISING GIVEN THE ACTIVE/PROGRESSIVE FLOW PATTERN.
FCST CONFIDENCE REMAINS GOOD THRU SUN...THEN IS AVERAGE FOR MON-WED.
CONTINUING LOW LEVEL WARM ADVECTION ON SUN SENDS 925MB TEMPS INTO
THE +9C TO +14C RANGE BY 00Z MON. BULK OF THE MOISTURE THRU SUN
LOOKS TO REMAIN HIGHER LEVEL. WITH SOME SUNSHINE...SOUTH GRADIENT
WINDS FOR MIXING AND SOUNDINGS SHOWING MIXING TO AROUND 900MB...
HIGHS IN THE MID 50S TO LOWER 60S ACROSS THE INCREASINGLY LIMITED
SNOW-COVERED SOUTHERN 1/2 TO 2/3 OF THE FCST AREA REASONABLE FOR
SUNDAY. MOISTURE/LIFT START TO INCREASE SUN NIGHT AS THE TROUGH/LOW
APPROACH. 20-40 PERCENT RAIN CHANCES SUN NIGHT REASONABLE. SFC-850MB
LOW MOVE ACROSS THE AREA MON. MON STARTS OUT RATHER WARM ON THE EAST
SIDE OF THIS LOW...WITH STRONG LOWER LEVEL COLD ADVECTION LOOKING TO
SEND TEMPERATURES DOWNWARD DURING THE AFTERNOON HOURS. GIVEN THE
MODEL CONSISTENCY...RAIN CHANCES IN THE 50-60 PERCENT RANGE LOOKING
GOOD FOR MON. TEMPS BACK BELOW NORMAL FOR MON NIGHT THRU TUE NIGHT
AS THE NEXT COOLER CAN HIGH BUILDS SOUTH INTO THE UPPER MIDWEST.
TEMPS REMAIN ON THE COOL SIDE WED AS THE NEXT TROUGH/LOW MOVE INTO
THE MID/UPPER MS VALLEY. TREND FOR THIS ONE IS FOR THE FCST AREA TO
REMAIN ON THE NORTH SIDE OF THE SFC-850MB CIRCULATION. POTENTIAL
EXITS FOR SOME ACCUMULATING SNOW ACROSS PORTIONS OF THE FCST AREA
TUE NIGHT INTO WED...BUT ANY DETAILS OF THIS FAR FROM CERTAIN AT
THIS TIME. MODEL/ENSEMBLE CONSENSUS OF HIGHS/LOWS FOR SUN-WED APPEAR
WELL TRENDED FOR NOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CDT WED MAR 26 2014
THE WINDS ALOFT HAVE INCREASED THIS EVENING WITH SEVERAL AREA RADARS
INDICATING WINDS OF 40 TO 45 KNOTS AT 925 MB. THE 27.00Z NAM AND
27.02Z RAP MAY STILL BE A LITTLE STRONG WITH THE WINDS ALOFT...BUT
CONTINUE TO INDICATE THE LOW LEVEL WIND SHEAR WILL CONTINUE THROUGH
THE NIGHT BEFORE ENDING EARLY THURSDAY MORNING. THE MVFR CLOUDS HAVE
BEEN SLOWER TO MOVE IN THAN EXPECTED BUT THEY ARE MAKING STEADY
PROGRESS ACROSS IOWA AND EXPECT TO SEE THEM ARRIVE DURING THE
OVERNIGHT HOURS. THE 27.01Z HRRR AGREES WITH THE NAM TAKING THE RAIN
COMING OUT OF MISSOURI OFF INTO EASTERN IOWA AND ILLINOIS AND
STAYING SOUTH OF BOTH TAF SITES. THE HRRR THEN SUGGESTS A PERIOD OF
LITTLE TO NO PRECIPITATION COULD OCCUR THROUGH THE MIDDLE OF
THURSDAY MORNING. THE NAM HAS BEEN HINTING AT THIS FOR A FEW MODEL
RUNS NOW AS WELL...SO HAVE JUST SHOWN SOME NON-VISIBILITY REDUCING
DRIZZLE THURSDAY MORNING AS THE CEILINGS CONTINUE TO COME DOWN BUT
REMAINING MVFR. IT APPEARS THE FORCING WILL BECOME STRONG ENOUGH
AHEAD OF THE NEXT WAVE FOR RAIN TO START DEVELOPING LATE THURSDAY
MORNING AND CONTINUING INTO THE AFTERNOON WITH IFR CONDITIONS
DEVELOPING. THE COLD FRONT SHOULD COME THROUGH LATE IN THE AFTERNOON
OR EARLY EVENING SWITCHING THE WINDS AROUND TO THE NORTHWEST WITH
THE PRECIPITATION MIXING WITH OR GOING OVER TO SNOW BEFORE ENDING AT
KRST BY LATE EVENING.
&&
.HYDROLOGY...
ISSUED AT 340 AM CDT THU MAR 27 2014
RAINFALL AMOUNTS OF AROUND A HALF INCH ARE EXPECTED THRU TODAY AND
TONIGHT. ANALYSIS OF THE HYDROLOGICAL SETUP SUGGESTS AREA STREAMS
AND RIVERS SHOULD BE ABLE TO HANDLE THESE RAIN AMOUNTS. HOWEVER
WILL HAVE TO WATCH FOR POTENTIAL PROBLEMS WITH SOILS STILL FROZEN.
SOME ICE STILL REMAINS ON THE RIVERS ACROSS THE NORTHERN PARTS OF
THE FCST AREA...ALONG WITH MORE SNOW COVER. WITH THE FROZEN
SOILS...PONDING OF WATER IN LOW LAYING AREAS IS LIKELY TO OCCUR.
WITH HIGHS IN THE 50S TO AROUND 60 ON SUNDAY AND IN THE 50S AGAIN ON
MONDAY...MELTING OF THE REMAINING SNOW COVER WILL ACCELERATE ALONG
WITH RUNOFF FROM THE SNOWMELT. SOME RISES ON AREA RIVERS AND STREAMS
CAN BE EXPECTED FROM THIS RUNOFF DURING THE EARLY/MID PARTS OF NEXT
WEEK. STAY TUNED TO THE LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...RRS
LONG TERM....RRS
AVIATION.....04
HYDROLOGY....RRS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1143 PM CDT WED MAR 26 2014
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 351 PM CDT WED MAR 26 2014
AT 3 PM...A 990 MB SURFACE LOW WAS DEVELOPING NEAR RAPID CITY
SOUTH DAKOTA. A WARM FRONT FROM GRAND FORKS NORTH DAKOTA TO
OELWEIN IOWA. TEMPERATURES SOUTH AND WEST OF THIS FRONT WERE IN
THE 40S AND 50S...AND IN THE 20S AND 30S NORTH AND EAST OF THIS
FRONT.
FOR EARLY THIS EVENING...BUFKIT SOUNDINGS SUGGEST THAT THE WINDS
ACROSS SOUTHEAST MINNESOTA AND NORTHEAST IOWA WILL GUST INTO THE
30 TO 40 MPH RANGE.
FOR TONIGHT...STRONG WARM AIR ADVECTION CONTINUES ACROSS THE
FORECAST AREA. IN ADDITION TO THIS...THERE IS MODERATE TO STRONG
850 MB MOISTURE CONVERGENCE AND 285 TO 295K ISENTROPIC UPGLIDE
AFTER 27.03Z TONIGHT FOR THE ENTIRE AREA. EXPECT THAT THE INITIAL
PRECIPITATION WILL DEVELOP ALONG AND NORTH OF INTERSTATE 94
ASSOCIATED WITH SOME STRONG 900 TO 800 MB FRONTOGENESIS...AND THEN
SPREAD ACROSS THE REMAINDER OF THE AREA BETWEEN 27.06Z AND 27.12Z
AS THE MOISTURE TRANSPORT INCREASES ACROSS THE AREA. SOUNDINGS
SUGGEST SOUTH OF INTERSTATE 94 THAT THE PRECIPITATION WILL BE
PRIMARILY BE RAIN. HOWEVER THE DRY AIR MAY CAUSE ENOUGH
EVAPORATIVE COOLING FOR A BRIEF PERIOD OF SLEET. MEANWHILE NORTH
OF INTERSTATE 94...THE PRECIPITATION WILL START OUT AS A WINTRY
MIX OF RAIN...SLEET...AND SNOW. LITTLE SNOW OR ICE ACCUMULATIONS
ARE EXPECTED.
FOR THURSDAY...THE SURFACE LOW WILL TRACK NORTHEAST ACROSS IOWA.
WITH THIS TRACK...THE WARM AIR WILL BE BROUGHT NORTHWARD INTO THE
AREA. SOUNDINGS SUGGEST THAT ALL OF THE WINTRY MIX WILL CHANGE
OVER TO RAIN. IN THE WARM SECTOR OF THIS SYSTEM /ACROSS PARTS OF
NORTHEAST IOWA AND SOUTHWEST WISCONSIN/...MOST UNSTABLE CAPES
CLIMB UP TO 300 J/KG LATE IN THE AFTERNOON AND EARLY EVENING. DUE
TO THIS...INTRODUCED A CHANCE OF THUNDERSTORMS. THE MOS GUIDANCE
COOLED TEMPERATURES A BIT...SO LOWERED THE HIGH TEMPERATURES BY A
COUPLE OF DEGREES.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 351 PM CDT WED MAR 26 2014
ON THURSDAY EVENING...STRONG COLD AIR ADVECTION QUICKLY DEVELOPS
IN THE WAKE OF THE SURFACE LOW. AS THIS OCCURS...THE RAIN WILL
QUICKLY TRANSITION OVER TO SNOW. SINCE THE PRECIPITATION WILL BE
STARTING TO MOVE OUT AT THE SAME TIME...SNOW ACCUMULATIONS WILL BE
ON THE LIGHT SIDES. UP TO 1.5 INCHES LOOKS POSSIBLE NORTH OF
WISCONSIN 29 IN NORTH CENTRAL WISCONSIN...AND A HALF OR LESS
ACROSS THE REMAINDER OF THE AREA.
SUNDAY...CONTINUES TO LOOK LIKE THE WARMEST DAY DURING THIS TIME
PERIOD. 850 MB TEMPERATURES CLIMB INTO THE 8 TO 12C RANGE DURING
THE AFTERNOON. MIXING THESE TEMPERATURES DOWN RESULTS IN HIGH
TEMPERATURES AROUND 50 NORTH OF INTERSTATE 94...AND FROM THE MID
50S TO AROUND 60 ACROSS THE REMAINDER OF THE AREA.
FROM SUNDAY NIGHT INTO TUESDAY...AND WEDNESDAY...TWO STRENGTHENING
LOW PRESSURE SYSTEMS WILL MOVE THROUGH THE REGION. DUE TO A DELAY
IN THE 12Z ECMWF HIGH RESOLUTION...THE ABILITY TO COMPARE THE GFS
TO OTHER MODELS WAS MUCH MORE LIMITED THAN USUAL. IN
ADDITION...THE GFS HAS FLUCTUATING ITS TRACK OVER THE PAST COUPLE
OF DAYS. DUE TO THIS...JUST STAYED WITH THE MODEL CONSENSUS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1143 PM CDT WED MAR 26 2014
THE WINDS ALOFT HAVE INCREASED THIS EVENING WITH SEVERAL AREA
RADARS INDICATING WINDS OF 40 TO 45 KNOTS AT 925 MB. THE 27.00Z
NAM AND 27.02Z RAP MAY STILL BE A LITTLE STRONG WITH THE WINDS
ALOFT...BUT CONTINUE TO INDICATE THE LOW LEVEL WIND SHEAR WILL
CONTINUE THROUGH THE NIGHT BEFORE ENDING EARLY THURSDAY MORNING.
THE MVFR CLOUDS HAVE BEEN SLOWER TO MOVE IN THAN EXPECTED BUT
THEY ARE MAKING STEADY PROGRESS ACROSS IOWA AND EXPECT TO SEE THEM
ARRIVE DURING THE OVERNIGHT HOURS. THE 27.01Z HRRR AGREES WITH THE
NAM TAKING THE RAIN COMING OUT OF MISSOURI OFF INTO EASTERN IOWA
AND ILLINOIS AND STAYING SOUTH OF BOTH TAF SITES. THE HRRR THEN
SUGGESTS A PERIOD OF LITTLE TO NO PRECIPITATION COULD OCCUR
THROUGH THE MIDDLE OF THURSDAY MORNING. THE NAM HAS BEEN HINTING
AT THIS FOR A FEW MODEL RUNS NOW AS WELL...SO HAVE JUST SHOWN SOME
NON-VISIBILITY REDUCING DRIZZLE THURSDAY MORNING AS THE CEILINGS
CONTINUE TO COME DOWN BUT REMAINING MVFR. IT APPEARS THE FORCING
WILL BECOME STRONG ENOUGH AHEAD OF THE NEXT WAVE FOR RAIN TO START
DEVELOPING LATE THURSDAY MORNING AND CONTINUING INTO THE AFTERNOON
WITH IFR CONDITIONS DEVELOPING. THE COLD FRONT SHOULD COME THROUGH
LATE IN THE AFTERNOON OR EARLY EVENING SWITCHING THE WINDS AROUND
TO THE NORTHWEST WITH THE PRECIPITATION MIXING WITH OR GOING OVER
TO SNOW BEFORE ENDING AT KRST BY LATE EVENING.
&&
.HYDROLOGY...
ISSUED AT 351 PM CDT WED MAR 26 2014
FROM THURSDAY INTO THURSDAY NIGHT...RAINFALL AMOUNTS OF AROUND A
HALF INCH IS EXPECTED. ANALYSIS OF HYDROLOGICAL SETUP SUGGESTS
AREA STREAMS AND RIVERS COULD HANDLE THESE RAIN AMOUNTS. HOWEVER
WILL HAVE TO WATCH FOR POTENTIAL PROBLEMS WITH ICE UPSTREAM OF
LAKE ARBUTUS ON THE BLACK RIVER. IN ADDITION WITH FROZEN GROUND...
THERE MAY BE SOME PONDING OF WATER ON SOME ROAD WAYS.
WITH HIGHS IN THE 50S TO NEAR 60 ON SUNDAY...WILL HAVE TO BE
WATCHED FOR ACCELERATED SNOW MELT AND RUNOFF. SOME RISES ON AREA
RIVERS AND STREAMS COULD BE EXPECTED FROM THIS RUNOFF EARLY NEXT
WEEK. STAY TUNED TO THE LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...04
HYDROLOGY...BOYNE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
339 AM EDT SAT MAR 29 2014
.SHORT TERM /TODAY THROUGH SUNDAY/...
500MB ANALYSIS SHOWS A POTENT SHORTWAVE ACROSS CENTRAL MS EARLY THIS
MORNING. THIS FEATURE IS ASSOCIATED WITH AN MCS MOVING INTO WESTERN
AL. THE CONVECTIVE ACTIVITY HAS DEVELOPED PRETTY FAR AHEAD OF THE
COLD FRONT WHICH IS CURRENTLY STILL ACROSS THE ARKLATEX ALONG WITH
THE DEVELOPING WAVE OF LOW PRESSURE.
THE SHORTWAVE WILL CONTINUE EAST TODAY AND MOVE ACROSS GA DURING THE
FIRST PART OF THE DAY. THE ASSOCIATED COLD POOL WILL STEEPEN MID
LEVEL LAPSE RATES SIGNIFICANTLY.
THE HRRR SEEMS TO HAVE A DECENT HANDLE ON THE CONVECTIVE ACTIVITY TO
THE WEST AND HAVE FOLLOWED FAIRLY CLOSELY FOR POPS. THE MAIN ISSUE
WILL BE THE POTENTIAL FOR SEVERE. STILL THINK THE BEST POTENTIAL FOR
SEVERE WILL BE THE EXTREME SOUTHEAST PORTION OF THE CWFA.
HOWEVER...ANOTHER THING TO CONSIDER WILL BE THE MOVEMENT OF THE
ACTIVITY ACROSS EASTERN MS/WESTERN AL. IF THE MCS CONTINUES TO SHIFT
TO THE SE...THIS COULD HELP LIMIT THE DEVELOPMENT OF WIDESPREAD
CONVECTION ACROSS THE CWFA.
NEWEST RUNS OF THE HRRR DO TAKE THE STRONGEST ACTIVITY ACROSS
SOUTHERN GA AND THE FLORIDA PANHANDLE DURING THE MORNING HOURS. THIS
WOULD MEAN THAT A FEW STRONG/ISOLATED SEVERE STORMS...ARE POSSIBLE
ACROSS THE EXTREME SOUTHERN PART OF THE CWFA. IN ADDITION...BEHIND
THE INITIAL MCS BUT STILL AHEAD OF THE COLD FRONT...THE HRRR HAS
SCATTERED THUNDERSTORMS BREAKING OUT ACROSS THE SE...SO THE
POTENTIAL FOR STRONG STORMS/ISOLD SEVERE MAY LAST INTO THE MID TO
LATE AFTERNOON HOURS...WHEN THERE IS MORE POTENTIAL FOR BREAKS IN
THE CLOUDS AND FOR SURFACE DESTABILIZATION TO OCCUR. LUCKILY...SHEAR
VALUES ARE RATHER WEAK...WITH THE BEST VALUES ALONG THE LAGGING COLD
FRONT THIS EVENING. IF SEVERE THUNDERSTORMS ARE ABLE TO
DEVELOP...DAMAGING WIND GUSTS AND LARGE HAIL WOULD BE THE PRIMARY
THREATS.
THE HRRR DOES CLEAR OUT THE POPS A BIT FASTER THAN PREVIOUSLY
FORECAST. HAVE TRIED TO ACCOUNT FOR THIS IN TIMING. TEMPS IN THE NE
WILL DIP DOWN INTO THE MIDDLE 30S TONIGHT...BUT LUCKILY...THE
FORECAST SHOULD BE DRY. TOO MARGINAL TO ISSUE A FREEZE WATCH...AND
THE WINDS MAY STAY UP OVERNIGHT JUST ENOUGH TO LIMIT FROST
DEVELOPMENT.
NLISTEMAA
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE DOMINATES FOR THE BEGINNING OF THE EXTENDED. A WEAK
FRONT APPROACHES THE AREA ON TUESDAY BUT THE PRECIPITATION
ASSOCIATED WITH IT SHOULD DIMINISH BEFORE REACHING THE STATE.
SYSTEM OF INTEREST IN THE EXTENDED THOUGH IS NEAR THE END. BOTH
THE ECMWF AND THE GFS LIFT A SFC LOW OUT OF THE MIDWEST AND INTO
THE OHIO VALLEY/GREAT LAKES REGION ON FRIDAY AND PUSHES SHOWERS AND
THUNDERSTORMS ACROSS THE CWA AHEAD OF A COLD FRONT THATS PROGGED
TO MOVE THROUGH FRIDAY NIGHT. STILL SOME DIFFERENCES BETWEEN THE
TWO MODELS IN TERMS OF FEATURE LOCATIONS...BUT OVERALL BOTH
SUGGEST A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE
WEEK. WILL HAVE TO CAREFULLY MONITOR FRIDAY FOR SEVERE WEATHER
POTENTIAL AS THE GFS INDICATES UP TO 2000 J/KG OF MUCAPE ON
FRIDAY WITH 30-40KTS OF LOW LEVEL SHEAR.
11
&&
.AVIATION...
06Z UPDATE...
COLD FRONT WILL MOVE THROUGH THE REGION TODAY. CURRENTLY...LIGHT
SHOWERS AND SPRINKLES SHOWING UP ON THE REGIONAL RADAR WHILE THE
STRONG THUNDERSTORMS ARE BACK OVER EASTERN MS. HRRR PROGS THE
THUNDERSTORMS TO BEGIN APPROACHING THE AL/GA BORDER AROUND 10Z AND
PROGRESSING EASTWARD THROUGH THE MORNING. WINDS ARE EXPECTED.
WINDS WILL TURN MORE WESTERLY BEHIND THE LINE OF STORMS...AND THEN
BACK TO THE NW LATER THIS EVENING BEHIND THE COLD FRONT. WINDS
BEHIND THE LINE WILL BE GUSTY.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 39 66 37 / 100 20 0 0
ATLANTA 65 39 64 42 / 100 10 0 0
BLAIRSVILLE 59 33 57 32 / 100 30 0 0
CARTERSVILLE 62 37 64 34 / 90 10 0 0
COLUMBUS 69 42 68 42 / 100 10 0 0
GAINESVILLE 63 38 64 40 / 100 20 0 0
MACON 70 42 67 37 / 100 10 0 0
ROME 62 37 65 34 / 80 10 0 0
PEACHTREE CITY 66 38 65 34 / 100 10 0 0
VIDALIA 72 45 69 41 / 80 30 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA
LONG TERM....11
AVIATION...NLISTEMAA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
309 AM EDT SAT MAR 29 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A COLD FRONT. THE FRONT WILL MOVE
THROUGH THE FORECAST AREA THIS EVENING. HIGH PRESSURE AND DRY
CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ISENTROPIC LIFT WILL SUPPORT NUMEROUS SHOWERS EARLY THIS MORNING.
THE MESOSCALE CONVECTIVE COMPLEX APPROACHING THE FORECAST AREA
FROM THE WEST SHOULD REACH THE AREA LATE THIS MORNING. RADAR
TRENDS AND THE LATEST HRRR INDICATE THE STRONGER CONVECTION WILL
REMAIN SOUTH OF THE AREA. STRONGER CONVERGENCE AHEAD OF THE COLD
FRONT SHOULD BEGIN TO ENTER THE FORECAST AREA FROM THE WEST AROUND
THE MIDDLE OF THE AFTERNOON. SHEAR WILL BE HIGH WITH H85 WINDS OF
30 TO 40 KNOTS SUPPORTING POSSIBLE SEVERE THUNDERSTORMS. THE
THREAT APPEARS LIMITED BECAUSE IT IS QUESTIONABLE HOW MUCH MOISTURE
AND INSTABILITY RECOVERY WILL OCCUR IN THE WAKE OF THE LARGE COMPLEX
THIS MORNING. THE THREAT OF THUNDERSTORMS WILL CONTINUE INTO THE
EVENING WITH THE COLD FRONT IN THE AREA AND COOLING ALOFT
ASSOCIATED WITH THE UPPER-LEVEL TROUGH. DRYING SHOULD OCCUR LATER
IN THE EVENING BEHIND THE COLD FRONT. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY THROUGH SUNDAY
NIGHT. IT WILL BE BREEZY SUNDAY AND A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED. THE GFS AND NAM MOS SUPPORT WINDS OF 15 TO 25
KNOTS. WINDS SHOULD DIMINISH SUNDAY NIGHT AS THE HIGH GETS CLOSER
TO THE AREA AND THE PRESSURE GRADIENT WEAKENS. STRONG NET
RADIATIONAL COOLING CONDITIONS SHOULD DEVELOP LATE. USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. EXPECT LOWS IN
THE MID AND UPPER 30S SUNDAY NIGHT WITH SCATTERED FROST. A FROST
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. WARMER TEMPERATURES SHOULD
OCCUR AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO
MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER
70S TO AROUND 80.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS ACROSS THE MIDLANDS SLOWLY MOVING EAST AS AN UPPER LEVEL
DISTURBANCE CROSSES THE AREA. WILL ABUNDANT LOW-LEVEL
MOISTURE...EXPECT IFR/POSSIBLE LIFR CIGS PERSISTING THROUGHOUT THE
EARLY MORNING HOURS. COULD SEE SCATTERED SHOWERS OR PATCHY DRIZZLE
CONTINUING DURING THE EARLY MORNING HOURS. MVFR CONDITIONS EXPECTED
TO RETURN AROUND 16Z SATURDAY AS SOUTHERLY WINDS INCREASE AHEAD OF
THE APPROACHING COLD FRONT. THERE SHOULD BE AN AREA SHOWERS/TSTMS TO
CROSS THE TAF SITES DURING THE AFTERNOON AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL CROSS THE TAF SITES AROUND THE END OF THE TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS AREA EXPECTED IN THE
WAKE OF THE FRONT SATURDAY NIGHT INTO SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
150 AM EDT SAT MAR 29 2014
.PREV DISCUSSION... /ISSUED 1022 PM EDT FRI MAR 28 2014/
UPDATE...HAS BEEN QUITE AN INTERESTING NIGHT AS INITIAL THOUGHTS
WERE THAT GULF COAST CONVECTION HAD SAVED US ONCE AGAIN AND WE
WOULD ONLY SEE A LIGHT RAIN SHIELD MOVE IN WITH LITTLE FANFARE.
AND FOR ALL OUTWARD APPEARANCES THAT IS WHAT HAPPENED...THAT IS
UNTIL A WAKE LOW FORMED OVER ALABAMA AND PROGRESSED EAST ALLOWING
FOR 4MB PRESSURE FALLS IN THE 2 HOUR PLOT. ALTHOUGH NOT WIDESPREAD
BY ANY MEANS...THIS RESULTED IN ISOLATED POCKETS OF WIND GUSTS IN
EXCESS OF 40 MPH AND LINED UP VERY WELL WITH 4MB BULLSEYE AS IT
TRACKED ACROSS THE FORECAST AREA. DAMAGE REPORTS FROM HOUSTON
COUNTY INCLUDED TREES DOWN INCLUDING SOME IN HOMES. IN LATEST
RADAR PICS...YOU CAN NOW SEE THE MESOVORTICE IN THE REFLECTIVITY
PATTERN AS IT EXITS THE FORECAST AREA.
FOR THE REMAINDER OF THE FORECAST...CONVECTION OVER NORTHERN
ARKANSAS WHICH RACED OUT AHEAD HAS BEEN IN THE MORE STABLE SECTOR
AND ELEVATED IN NATURE. REGIONAL CAPE ANALYSIS SHOWS ALL SURFACE
BASED CAPE TO BE SOUTH ACROSS MISSISSIPPI AND ALABAMA WITH NON
NOTED TO THE EAST AT THIS TIME INCLUDING GEORGIA. EXPECT A SIMILAR
SCENARIO TO TODAY WITH SOUTHERN ACTIVITY TAKING OVER AND DIVING SE
AS IT LOOKS FOR THE MORE ENRICHED AIR ALONG THE GULF COAST. NORTHERN
ACTIVITY WHICH WILL AFFECT US WILL STILL BE CAPABLE OF PRODUCING
THUNDERSTORMS AND ISOLATED STRONG GUSTS BUT GREATEST POTENTIAL FOR
SEVERE WILL REMAIN SOUTH OF THE AREA. SHERB PLOT CONFIRMS THIS
TAKING THE 1 UNIT VALUES SOUTH OF THE AREA BUT PLENTY OF HIGH END 9
VALUES TO KEEP AN EYE ON OUR ZONES ALONG AND SOUTH OF A COLUMBUS
TO MACON LINE. CLEANED UP POPS AND ADJUSTED TIMING A BIT IN GRIDS.
OTHERWISE NO OTHER CHANGES PLANNED.
DEESE
PREV DISCUSSION... /ISSUED 736 PM EDT FRI MAR 28 2014/
PREV DISCUSSION... /ISSUED 343 PM EDT FRI MAR 28 2014/
SHORT TERM /TONIGHT THROUGH SATURDAY NIGHT/...
MODELS HAVE HAD A POOR HANDLE ON THE CURRENT SITUATION...AND OVERALL
FORECAST CONFIDENCE IS MEDIUM. LARGE AREA OF RAINFALL ACROSS THE
AREA TODAY HAS BEEN FURTHER SOUTH THAN PREVIOUS MODELS AND FORECAST
HAD INDICATED. LARGE COMPLEX OVER THE NORTHERN GULF HAS CUT OFF THE
MOISTURE INFLUX INTO THE AREA AND PREVENTED THE CWA FROM SEEING ANY
SIGNIFICANT CONVECTION. AS OF THIS AFTERNOON...RAINFALL AMOUNTS
ACROSS THE AREA WERE HIGHEST ALONG THE AL/GA LINE...WITH 1.5
INCHES...AND DIMINISHED EASTWARD WITH ONLY 0.25 INCHES IN THE
EASTERN PORTIONS OF THE STATE.
MODELS ARE SUGGESTING A BREAK IN THE PRECIP THIS EVENING INTO THE
OVERNIGHT HOURS BEFORE THE NEXT WAVE OF PRECIPITATION ASSOCIATED
WITH THE FRONT AS IT PUSHES THROUGH THE AREA. LATEST MODEL RUNS DO
NOT DEPICT MUCH IN THE WAY OF ORGANIZED CONVECTION EARLY MORNING AND
THROUGH THE DAY SATURDAY...WITH A SIMILAR SITUATION AS TODAY WITH A
COMPLEX OVER THE NORTHERN GULF RESTRICTING THE CWAS CHANCE OF
THUNDERSTORMS. THAT BEING SAID...A FEW MODELS /LARGELY THE GFS/ IS
CONTINUING TO SHOW CAPE VALUES IN THE 1200-1400 J/KG ACROSS THE FAR
SOUTHERN AND EASTERN PORTIONS OF THE CWA SATURDAY LATE MORNING
THROUGH THE AFTERNOON. OTHER MODELS HAVE 200-500 J/KG. ALTHOUGH THE
INITIAL THINKING WAS THAT THIS PORTION OF THE CWA WOULD HAVE MORE
OPPORTUNITY FOR HEATING SATURDAY WITH LESS CLOUD COVER...MODELS HAVE
INCREASED MOISTURE TO THAT AREA...AND DO NOT ANTICIPATE MUCH
INSOLATION. OVERALL THE BEST SHEAR DOES NOT COINCIDE WITH THE BEST
MODELED INSTABILITY...ASSOCIATED MORE WITH THE FRONT ITSELF. AS A
RESULT...HAVE CAPPED MENTION OF THUNDER TO CHANCE FOR SATURDAY. THE
POTENTIAL FOR STRONG STORMS STILL EXISTS...AND THOUGH THE RISK OF
SEVERE STORMS HAS DIMINISHED SOMEWHAT IN THE MODELS...ISOLATED
SEVERE STORMS MAY STILL BE POSSIBLE IN THE SE PORTION OF THE CWA.
THE MAIN CONCERN WOULD BE DAMAGING WINDS.
ADDITIONAL WIDESPREAD RAINFALL AMOUNTS OF 1.0 INCHES WITH LOCALLY
HIGHER AMOUNTS CAN BE EXPECTED THROUGH SATURDAY AFTERNOON. AT THIS
TIME THE AREA HAS BEEN ABLE TO HANDLE THE RAINFALL WELL...AND DO NOT
ANTICIPATE WIDESPREAD FLOODING CONCERNS.
THE RAIN EXITS THE STATE LATE SATURDAY AFTERNOON WITH CLEARING
QUICKLY BEHIND IT. WITH GRADIENT WINDS INCREASING SATURDAY
AFTERNOON...THERE IS A POSSIBILITY OF MEETING WIND ADVISORY CRITERIA
IN THE HIGHER ELEVATIONS OF NORTH GEORGIA. WILL ALLOW THE NEXT
SHIFTS TO REEVALUATE THE NEED FOR A WIND ADVISORY AND WILL HOLD OFF
FOR NOW.
31
LONG TERM /SUNDAY THROUGH FRIDAY/...
MADE SOME ADJUSTMENTS TO LOWER POPS AND THUNDERSTORM POTENTIAL
THURSDAY THEN INCREASE POTENTIAL FOR FRIDAY BASED ON LATEST MODEL
SOLUTIONS. WILL HAVE TO WATCH TRENDS WITH POSSIBLE STRONG FRONT MOVING
THROUGH AREA FRIDAY /GIVEN 12Z RUN OF GFS/ AND ANY POTENTIAL FOR
STRONGER STORM DEVELOPMENT ASSOCIATED WITH IT. MUCH COULD HAPPEN
THIS LATE IN THE FORECAST. ALSO...ANY POTENTIAL FOR LIGHT SNOW
SATURDAY NIGHT LOOKS TO BE OUTSIDE OF THE CWA. OTHERWISE FORECAST
LOOKS TO BE ON TRACK AND PREVIOUS DISCUSSION FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 341 AM EDT FRI MAR 28 2014/
LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
FOR THE MOST PART...SYSTEM THAT BRINGS RAIN TO THE AREA IN THE
SHORT TERM SHOULD HAVE EXITED THE AREA BY THE BEGINNING OF THE
LONG TERM. THE EXCEPTION TO THIS IS ACROSS FAR NORTHEAST GEORGIA
AND THE FAR SOUTHEAST PART OF THE CWA WHERE SOME RAIN COULD LINGER
THROUGH SATURDAY NIGHT. AT THIS POINT...IT APPEARS THE
PRECIPITATION SHOULD END ACROSS THE NE GA MOUNTAINS BEFORE THE
COOLER TEMPERATURES MOVE IN. AFTER THIS HIGH PRESSURE WILL
DOMINATE THROUGH ABOUT MID WEEK. BOTH THE GFS AND THE ECMWF
SUGGEST THE NEXT SYSTEM MOVING THROUGH IN THE LATER HALF OF THE
WEEK. INSTABILITY VALUES SUPPORT THE MENTION OF THUNDER IN THE
FORECAST THURSDAY INTO FRIDAY.
11
&&
.AVIATION...
06Z UPDATE...
COLD FRONT WILL MOVE THROUGH THE REGION TODAY. CURRENTLY...LIGHT
SHOWERS AND SPRINKLES SHOWING UP ON THE REGIONAL RADAR WHILE THE
STRONG THUNDERSTORMS ARE BACK OVER EASTERN MS. HRRR PROGS THE
THUNDERSTORMS TO BEGIN APPROACHING THE AL/GA BORDER AROUND 10Z AND
PROGRESSING EASTWARD THROUGH THE MORNING. WINDS ARE EXPECTED.
WINDS WILL TURN MORE WESTERLY BEHIND THE LINE OF STORMS...AND THEN
BACK TO THE NW LATER THIS EVENING BEHIND THE COLD FRONT. WINDS
BEHIND THE LINE WILL BE GUSTY.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 42 69 38 / 70 20 0 0
ATLANTA 69 42 65 42 / 90 10 0 0
BLAIRSVILLE 65 37 62 34 / 70 30 0 0
CARTERSVILLE 69 41 65 36 / 80 10 0 0
COLUMBUS 73 47 70 42 / 100 10 0 0
GAINESVILLE 68 41 64 40 / 80 20 0 0
MACON 74 44 71 38 / 100 10 0 0
ROME 68 42 66 35 / 80 10 0 0
PEACHTREE CITY 71 41 67 35 / 100 10 0 0
VIDALIA 75 48 71 43 / 90 30 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 AM CDT SAT MAR 29 2014
.DISCUSSION...
302 AM CDT
TODAY...
THIS MORNING...RIDGE OF HIGH PRESSURE EXTENDS FROM LAKE SUPERIOR
INTO THE MID MISSOURI VALLEY WHILE LOW PRESSURE LIES OVER
MISSISSIPPI/ALABAMA. THIS LOW WILL LIFT NORTH INTO THE UPPER OHIO
VALLEY TODAY RESULTING IN NORTHEASTERLY WINDS OFF OF LAKE MICHIGAN
THROUGH THE DAY. SOME PRECIP MAY BRUSH THE FAR SOUTHEASTERN COUNTIES
THIS MORNING...MAINLY IN THE FORM OF SNOW...THOUGH ANY ACCUMULATION
WILL LIKELY BE CONFINED TO GRASSY AREAS AND ONLY A DUSTING IS
EXPECTED. SPLIT CHANNEL IR IMAGERY SHOWS STRATUS STILL SPANS MUCH OF
THE UPPER MIDWEST...AS FAR WEST AS CENTRAL IOWA AND NORTHWEST INTO
CENTRAL WISCONSIN. EXPECT CLOUD COVER TO LINGER THROUGH AT LEAST
MIDDAY...THEN ANTICYCLONIC FLOW WITH THE RIDGE AXIS SHOULD START TO
BUILD IN FROM THE NORTHWEST THIS AFTERNOON AND EVENING WITH SKIES
CLEARING. TEMPERATURES TODAY ARE EXPECTED TO WARM INTO THE LOW TO
MID 40S...THOUGH WILL STAY IN THE 30S NEAR THE LAKE WITH THE
OFFSHORE FLOW THROUGH THE DAY.
SUNDAY AND MONDAY...
COMPACT UPPER WAVE WILL MOVE ONSHORE OVER SOCAL EARLY SUNDAY...THEN
TRANSLATE EAST ACROSS THE CENTRAL PLAINS BY MONDAY. SURFACE LOW WILL
DEEPEN IN RESPONSE OVER THE CENTRAL PLAINS THROUGH THE PERIOD WITH
STRONG WARM ADVECTION INTO THE REGION HELPING TO AMPLIFY THE
MID/UPPER LEVEL RIDGING. H85 TEMPS WILL WARM TO AROUND 10C BY SUNDAY
EVENING...AND 12C TO 13C BY MONDAY. CLIMO FROM NARR DATASET SHOWS
MEDIAN TEMPS IN THE LOW 70S WHEN H85 TEMPS EXCEED AROUND 9C FOR THE
LATTER HALF OF MARCH. WHILE THESE WARMER TEMPERATURES ALOFT WILL
ARRIVE LATER IN THE DAY SUNDAY...THEY SHOULD BE DIRECTLY OVERHEAD ON
MONDAY WHICH IS EXPECTED TO BE THE WARMEST DAY IN SOME TIME. BACKED
OFF SLIGHTLY ON TEMPS FOR SUNDAY...AND WHILE I THINK AREAS
ESPECIALLY IN THE WESTERN CWA STILL HAVE A GOOD CHANCE OF 60...IT
MAY STRUGGLE TO REACH 60 IN CHICAGO AND EASTERN PORTIONS OF THE CWA
DUE TO THE SLOWER ARRIVAL. THE MAIN CONCERNS FOR TEMPS MONDAY REVOLVE
AROUND CONVECTIVE CHANCES AND CLOUD COVER WHICH WILL INHIBIT HOW
WARM WE GET. H5 VORT TAKES ON A NEGATIVE TILT MONDAY AS IT LIFTS
ACROSS THE MID-MISSOURI VALLEY AND LEFT EXIT REGION OF UPPER JET
OVER THE AREA WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. LATEST
THINKING ON TIMING OF THE LOW STILL HAS THE BETTER FORCING WELL TO
THE WEST DURING PEAK HEATING WHEN SOME VERY MODEST SURFACE BASED
INSTABILITY EXISTS. WITH THUNDERSTORMS DEVELOPING TO THE
WEST...COULD SEE CIRRUS STREAMING OVERHEAD DURING THE DAY MONDAY
WHICH WILL IMPACT TEMPS. WITH A PRETTY DYNAMIC SYSTEM...MAY BE ABLE
TO OVERCOME THE LACK OF FAVORABLE THERMODYNAMICS FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP...PARTICULARLY IN THE LATER
AFTERNOON AND EVENING. REFINED POPS TO REFLECT THESE TIMING DETAILS
BUT MAINTAINED 20 TO 30 PERCENT DUE TO COVERAGE CONCERNS. AS FAR AS
TEMPS...REMAIN ON THE WARM SIDE OF THE SOLUTION ENVELOPE BUT WILL
HOLD OFF ON GOING ABOVE GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND
UNCERTAINTY IN PRECIP. WINDS WILL BECOME PROGRESSIVELY BREEZY
THROUGH THIS PERIOD...WITH GUSTS TO AROUND 20 MPH POSSIBLE ON SUNDAY
AND EVEN BREEZIER CONDITIONS ON MONDAY. 50KT WINDS ARE NOTED AROUND
900MB MONDAY...AND WITH DEEP MIXING POSSIBLE...THE AREA MAY SEE
30MPH+ GUSTS AT THE SURFACE DURING THE AFTERNOON.
TUESDAY THROUGH FRIDAY...
AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THE UPCOMING WORK WEEK AS A SERIES OF WAVES PROGRESS ACROSS THE
REGION. STILL CONSIDERABLE TIMING/TRACK DIFFERENCES THOUGH GUIDANCE
DOES SEEM TO BE FAVORING A MORE SOUTHERLY/COOLER PATTERN...
ESPECIALLY THE GFS WITH GOOD SUPPORT FROM THE GEFS. THE EMCWF
MAINTAINS A WARMER SOLUTION...WITH BAROCLINIC ZONE VERY NEAR
RESULTING IN A DECENT TEMPS SPREAD NORTH TO SOUTH ACROSS THE CWA.
CONTINUE TO RUN WITH A MODEL CONSENSUS BLEND FOR TEMPS NEXT WEEK
GIVEN THE HIGH DEGREE OF UNCERTAINTY...WHICH RESULTS IN WELL BELOW
NORMAL TEMPS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* A PERIOD OF LIGHT SNOW IS POSSIBLE OVERNIGHT AND TOWARD MORNING.
THIS WOULD MOST LIKELY BE WEST OF THE ORD/MDW AREA.
* EAST WINDS BECOMING NORTHEAST WITH MVFR CEILINGS PERSISTING
INTO MID TO LATE MORNING.
LENNING
//DISCUSSION...UPDATED 06Z...
RADAR RETURNS ARE SHOWING AN ELEVATED BAND OF SNOW ACROSS EASTERN
IOWA AND NW ILLINOIS. 06Z HOURLY SURFACE OBSERVATIONS HAVE YET TO
SHOW ANYTHING REACHING THE GROUND...AND THE FORECAST MODELS THAT
DEPICT THIS FEATURE KEEP IT LIMITED TO THE RFD AREA RATHER THAN
MOVING IT EAST. THAT LEAVES MVFR CIGS AND EASTERLY WINDS THROUGH
THE PREDAWN HOURS. WINDS GRADUALLY TURN MORE NORTHERLY TOWARD
MORNING BUT PROBABLY WILL NOT GO AROUND TO WEST OF NORTH. INSTEAD
THEY AGAIN GO MORE EASTERLY TOWARD EVENING AS A RIDGE OF HIGH
PRESSURE MOVES INTO THE AREA. WITH THIS HIGH SHOULD COME
SCATTERING CEILINGS AT SOME POINT TOWARD LATE MORNING OR EARLY
AFTERNOON.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE FOR ALL ELEMENTS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
SUNDAY...VFR.
MONDAY...CHANCE OF TSRA. GUSTY SOUTH WINDS.
TUESDAY...SLGT CHC OF RAIN DURING THE NIGHT.
WEDNESDAY...RAIN AND MVFR LIKELY.
THURSDAY...SLGT CHC OF RAIN AND SNOW.
MTF
&&
.MARINE...
117 PM CDT
FAIRLY TYPICAL ACTIVE SPRING WEATHER PATTERN EXPECTED THROUGH NEXT
WEEK. HIGH PRESSURE SHOULD MOVE ACROSS THE LAKES THIS WEEKEND BUT A
SYSTEM PASSING TO OUR SOUTH THROUGH THE TENNESSEE VALLEY SHOULD
RESULT IN A BIT OF A NORTH WIND OVER SOUTHERN PORTIONS OF THE LAKE.
ANOTHER LOW WILL PASS WELL TO OUR NORTH ON SUNDAY RESULTING IN A
WIND SHIFT TO THE SOUTH FOLLOWED BY YET ANOTHER...MUCH STRONGER LOW
OVER THE PLAINS WHICH SHOULD RESULT IN STRONG SOUTHERLY WINDS
MONDAY. STABILITY ISSUES LOOK TO COME INTO PLAY AS 60F TEMPS RUN
INTO THE MARINE BOUNDARY LAYER AND RESULT IN VERY SHALLOW MIXING.
GRADIENT LOOKS TO BE STRONG ENOUGH TO RESULT IN STRONG
WINDS...THOUGH THE LIMITED MIXING COULD POTENTIALLY MAKE IT HARD TO
REACH GALES EXCEPT PERHAPS IN THE OFFSHORE FLOW ALONG THE NEARSHORE.
IZZI
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
228 AM CDT Sat Mar 29 2014
.DISCUSSION...
ISSUED 227 AM CDT Sat Mar 29 2014
Surface low tracking across northern Mississippi early this
morning, while an upper trough moves through Iowa and western
Missouri. Area of showers streaming northward ahead of the upper
trough has made it up to around Taylorville and Sullivan as of 2
am, although the leading edge has had to fight some dry air to
make it that far.
A rather active weather pattern is on tap for next week, with
precipitation timing the primary forecast concern.
SHORT TERM...Today through Monday:
Will maintain some precipitation chances across the far eastern
CWA for the first few hours after sunrise, until the trough moves
into Illinois. Forecast soundings off the RAP model suggest some
rain/snow mix north of I-70 until the ice crystals are lost by mid
morning, with rain to the south. Otherwise, will see a decrease in
clouds from west to east this afternoon, as ridge axis moves
southeast out of the northern Plains.
Decent warm air advection sets up early Sunday as the high drifts
east of the state. With abundant sunshine, have sided more toward
the MAV MOS highs in the lower to mid 60s, with temperatures in
the mid to upper 60s on Monday. Monday looks to be fairly windy
ahead of the next storm system, with Bufkit data suggesting wind
gusts of 30-40 mph. Main surface low expected to track northeast
into southern Minnesota by late afternoon, with the trailing cold
front sweeping through the forecast area during the evening. Lower
levels of the forecast soundings are rather dry though except for
a brief window late afternoon and early evening, so will maintain
PoP`s only in the 30 percent range.
LONG TERM...Tuesday through Friday:
Upper troughing begins to dig across California Tuesday night as a
closed low moves southeast toward Los Angeles. As the week
progresses, the question becomes how deep this remains and how
fast the remaining closed low is ejected northeast. GFS and ECMWF
maintain a rather wide range as a storm system develops over the
Plains. The GFS remains much further south, with more of an
inverted trough extending over southeast Illinois by Thursday
morning. The ECMWF loiters a warm front just north of I-72 most of
Wednesday and Thursday, before the parent low arrives Thursday
evening. Both solutions would favor widespread showers, although
the warmer ECMWF would suggest thunder being more widespread. Have
not changed too much from the previous forecast, which favored the
ECMWF and warmer temperatures.
Geelhart
&&
.AVIATION...
ISSUED 1150 PM CDT Fri Mar 28 2014
Surface wave over southeast Arkansas, a reflection of a southern
stream mid-level wave, is moving northeast along stationary front.
In addition, an inverted trough near the Mississippi River is
associated with a northern stream wave. Moisture streaming ahead
of the southern system is beginning to be pulled northward ahead
of the inverted trough. precipitation will likely begin to develop
in the eastern terminals over next few hours.
CIGs have been low MVFR through Friday and have been relatively
uniform across much of the region. These CIGs will likely remain
in the 015-025 range until the inverted trough moves through Saturday
morning. Abundant boundary layer moisture trapped beneath the inversion
should make any CIG slow to rise and thin though should scatter
out by early evening Saturday as ridge builds in from the west and
drier air advects into the TAF sites.
Northerly winds should increase early Saturday as low/trough pulls
off to the east and gradient increases ahead of plains ridge.
Ridge moves across terminals Saturday evening enabling winds to
quickly diminish around sunset.
Barker
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
437 AM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 840 PM EDT FRI MAR 28 2014
LIGHT SNOW WILL BEGIN ACROSS THE AREA THIS MORNING HOURS. THE SNOW
MAY BE MIXED WITH RAIN AT TIMES. TOTAL SNOWFALL ACCUMULATIONS UP
TO AN INCH ARE EXPECTED SOUTHEAST OF US HIGHWAY 24. ONLY A TRACE
OF SNOW EXPECTED ELSEWHERE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 128 AM EDT SAT MAR 29 2014
SUBSTANTIAL POST FNTL INVERSION BENEATH INCREASING MID LVL MSTR
ADVTN INADV OF AMPLIFYING SW DISTURBANCE OVR WRN IA WILL LOCK IN
MVFR STRATOCU CIGS THROUGH SAT MORNING. VSBY RESTRICTIONS LIKELY AT
KFWA AS BURGEONING MID LVL CIRC DVLPS TWD 12Z BUT XPCD TO RAPIDLY
BREAKDOWN TWD 18Z. STG SUBSIDENT DRYING WIL FOLLOW IN WAKE OF EWD
EJECTING SYS LT THIS AFTN W/VFR CONDS DVLPG INTO ERLY EVENING.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...SKIPPER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
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AREA FORECAST DISCUSSION...CORRECTED TYPO
NWS QUAD CITIES IA IL
425 AM CDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 240 AM CDT SAT MAR 29 2014
AN UPPER LEVEL SHORTWAVE WITH SEVERAL EMBEDDED COMPACT VORT MAXIMA
WAS EVIDENT ON SATELLITE WV IMAGES MOVING THROUGH CENTRAL IA AND
WESTERN MO AT 07Z. AREA RADARS INDICATED A FEW WEAK ECHOES IN THE
LIFT AHEAD OF THIS FEATURE FROM SW WI ALONG THE MS RIVER TO W
CENTRAL IL. AREA OBSERVATIONS HAVE YET TO INDICATE ANY PRECIPITATION
REACHING THE GROUND FROM THESE WEAK RETURNS. AN INVERTED TROUGH AT
THE SURFACE...REACHING FROM THE CENTRAL IL INTO EAST CENTRAL
IA...WAS PROVIDING ENOUGH LOW LEVEL CONVERGENCE TO KEEP THE
WIDESPREAD STRATUS THAT NEVER LEFT THE AREA YESTERDAY IN PLACE. THE
00Z KDVN SOUNDING SHOWED AN ASSOCIATED SHALLOW LAYER OF MOISTURE
TRAPPED JUST BELOW AN INVERSION AND WEDGE OF DRY AIR ABOVE 900 MB.
UPSTREAM...A LARGE UPPER LOW WAS OFF THE BC COAST WITH A DOWNSTREAM
RIDGE AXIS MOVING THROUGH THE NORTHERN ROCKIES. AHEAD OF THIS UPPER
RIDGE...HIGH PRESSURE AT THE SURFACE REACHED FROM NEB INTO NORTHERN
MN. UNDER THIS RIDGE...SKIES WERE MAINLY CLEAR AND THE MUCH DRIER
AIRMASS FEATURED DEWPOINTS IN THE TEENS AND 20S...CONTRASTING TO THE
UPPER 20S TO LOWER 30S CURRENTLY OVER THE FORECAST AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT SAT MAR 29 2014
MAIN CHALLENGE CENTERS ON HOW FAST CLOUDS WILL CLEAR TODAY AND THE
IMPACT ON TEMPERATURES IN THE SHORT TERM. THE ADVANCING UPSTREAM
UPPER RIDGE AND DEEPENING AND PHASING OF THE DOWNSTREAM TROUGH OVER
THE OHIO VALLEY TODAY WILL RESULT IN A DEVELOPING MORE FAVORABLE
SUBSIDENCE REGIME THAN YESTERDAY. HOWEVER...THIS APPEARS TO BE A
SLOW PROCESS...AND MAY NOT RESULT IN ANY SIGNIFICANT CLEARING UNTIL
AFTERNOON.
AT THE SURFACE...A DEEPENING LOW PRESSURE SYSTEM RIDING NORTHEAST
THROUGH KY AND TN WILL IS SHOWN KEEPING AT LEAST A WEAK CYCLONIC
CURVATURE IN THE SURFACE PRESSURE FIELD EXTENDING NORTHEAST INTO
EASTERN IA UNTIL MIDDAY. THE ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AND TRAPPED MOISTURE BELOW THE LINGERING INVERSION ALOFT...WILL KEEP
THE STRATUS HOLDING IN PLACE OVER MOST THE FORECAST AREA THIS
MORNING. THE BACK EDGE OF THE CLOUDS...CURRENTLY SLOWLY ADVANCING
E-SE ACROSS N CENTRAL AND FAR WESTERN IA WILL LIKELY COME TO A HALT
OVER CENTRAL IA INTO EASTERN IA THIS MORNING. FORECAST MODELS
CONTINUE TO STRUGGLE WITH THIS...AND AT THIS TIME ONLY THE RAP 900
MB RH FIELD SEEMS TO HAVE A GOOD HANDLE ON THIS TREND. WILL THUS KEEP
MOSTLY CLOUDY SKIES GOING THROUGH THE MORNING...THEN TRANSITION TO
MOSTLY SUNNY BY AFTERNOON AS THE SURFACE AND UPPER LEVEL RIDGE MOVE
OVERHEAD BRINGING SUBSIDENCE AND DRIER AIR. ACCOUNTING FOR THIS
DELAYED WARMING...AND WEAK MIXING UNDER THE RIDGE...HAVE HELD HIGH
TEMPERATURES AT THE LOWER END OF GUIDANCE...FROM THE MID 40S NORTH
TO LOWER 50S SOUTH.
TONIGHT...SKIES WILL START OUT CLEAR WITH ADVANCING HIGH CLOUDS
FOLLOWING PASSAGE OF THE UPPER RIDGE AXIS TOWARD MORNING. AT THE SURFACE...
INITIALLY LIGHT WINDS WILL TURN SOUTHERLY AND INCREASE TO AT LEAST 5
TO 10 KTS TOWARD MORNING AS A TROUGH MOVES INTO THE PLAINS. THIS
WOULD SUPPORT AN INITIAL COOL-DOWN AFTER SUNSET...THEN STEADY TO
POSSIBLY EVEN RISING TEMPERATURES TOWARD SUNRISE. WITH MOST MODELS
OVERALL TRENDING TOO MOIST IN THE LOWER LEVELS...HAVE GONE CLOSER TO
THE BETTER INITIALIZING ECMWF WITH ITS LOWER DEWPOINTS IN THE 20S
BEFORE THE RETURN FLOW SETS UP. THIS POINTS TOWARD LOWER MINS THAN
MOS...AND HAVE GONE WITH LOWS FROM THE MID 20S EAST TO LOWER 30S IN
THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 AM CDT SAT MAR 29 2014
MILD WITH A FAST MOVING DISTURBANCE MONDAY...THEN FAVORABLE SETUP
FOR SIGNIFICANT TO HEAVY PRECIPITATION MID TO LATE NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION AVERAGE WITH STILL QUESTIONS
ON PHASING OF PACIFIC ENERGY ARRIVING NEXT FEW DAYS. AGAIN POOR BL
ISSUES THAT ARE OFF BY 3-5 DEGREES FOR BOTH T AND T/D THAT MOS OR
OTHER ALGORITHMS ARE HAVING PROBLEMS HANDLING. TREND IS FOR A DEEPER
TROUGH INTO THE PACIFIC SW BY TUESDAY WHICH IS A GOOD REGIME FOR
MODERATE TO HEAVY PRECIPITATION...MOSTLY RAIN WITH STALLED FRONT
TO OUR SOUTH FOR PROLONGED UPGLIDE. VARIANCES CONTINUE WITH HI-RES ECMWF
BY FAR THE FURTHEST NORTH. RUN TO RUN TRENDS AND VARIANCES SUPPORTS
A MIX OF THE UKMET/GFS /GEM-NH AND TO DISREGARD THE HI-RES ECMWF.
TRENDS ARE FOR NORTH PORTIONS TO SEE AT LEAST A FEW PERIODS OF A
MIX OF RAIN AND WET SNOW WHICH WILL TAKE ANOTHER 24 HOURS TO BETTER
ASCERTAIN. THIS 2 TO 3 DAY EVENT WEDNESDAY INTO FRIDAY WILL BE THE
HEAVIEST PRECIPITATION EVENT...WIDESPREAD 1 TO 2 PLUS INCH AMOUNTS
SINCE LAST FALL. CONDITIONS OF THIS TYPE CONTINUE TO SUGGEST WILL
HELP REPLENISH THE MODESTLY DRY SOILS AND PREPARE THE GROUND FOR
SPRING.
SUNDAY...EXPECT MODERATE BL MIXING AND MODERATE SOUTHERLY WINDS OF UP
TO 15 TO 25+ PH IN THE AFTERNOON. TRENDS STILL SUPPORT HIGHS IN LOWER
TO MIDDLE 60S WITH AFTERNOON RH VALUES FALLING BELOW 50 PERCENT TO
LOCALLY NEAR 40 PERCENT. THIS INDICATES GFDI VALUES INTO VERY HIGH
CATEGORY FOR SEVERAL HOURS IN THE AFTERNOON...MAINLY WEST OF THE
MISSISSIPPI RIVER DUE TO LITTLE TO NO GREENING OF VEGETATION. THIS
WILL REMAIN IN THE HWO PRODUCT. SUNDAY NIGHT...SOUTH WINDS OF 10 TO
20 MPH TO MAKE FOR THE MILDEST NIGHT IN MANY MONTHS DESPITE FAIR SKIES
WITH LOWS IN THE MID TO UPPER 40S....TO AROUND 50F SOUTH.
MONDAY...NEXT VIGOROUS AND FAST MOVING STORM SYSTEM SIMILAR TO YESTERDAY/S.
IS SLIGHTLY SLOWER...KEEPING MID CHANCE POPS WITH SHOWERS AND ISOLATED
MAINLY PM STORMS. WINDS WILL BE STRONGER ALLOWING FOR LOWER PM DEWPOINTS.
MID LEVEL SHOWERS AND ISOLATED STORMS WITH BASES AOA 6K AGL. LOW FREEZING
LEVEL STILL SUGGESTS NON-SEVERE STORMS WITH SOME PEA HAIL POSSIBLE AS
ANY STORMS WOULD FIRE OVER CWA IN MID/LATE PM HOURS. RAISED HIGHS BY
2-3 DEGREES INTO THE MID/UPPER 60S. WINDS MID DAY SHOULD BECOME QUITE
WINDY APPROACHING WIND ADVISORY CRITERIA OF 20 TO 30 MPH WITH GUSTS
TO AROUND 40 MPH. RH VALUES SHOULD FALL TO AROUND 50 PERCENT THAT MAY
SUPPORT NEAR VERY HIGH CONDITIONS FOR FIRE WEATHER BUT SHOWERS/STORMS
SHOULD AMELIORATE A BIT ALONG WITH HIGHER RH VALUES. MONDAY NIGHT...SLIGHTLY
DELAYED TIMING OF COOL FRONTAL PASSAGE INTO MID/LATE EVENING AND GUSTY
NW WINDS TO LIMIT COOLING BY MORNING. THIS SUGGESTS MINS NEAR GUIDANCE
BLEND...OR UPPER 20S FAR NW TO MIDDLE 30S FAR SE SECTIONS.
TUESDAY...LITTLE CHANGE TO CURRENT FORECAST. COOLER AND MOSTLY FAIR
SKIES WITH HIGHS MOSTLY OF 45 TO 50 DEGREES AND LIGHT NE WINDS AHEAD
OF NEXT...LARGE...SLOW MOVING AND QUITE STRONG UPPER DISTURBANCE AND
DEEP TROUGH MOVING EAST FROM CALIFORNIA. TUESDAY NIGHT...INCREASING
CLOUDS STILL SUGGEST LOWS TO OCCUR NEAR OR BEFORE MIDNIGHT....THEN
RISING TOWARD MORNING WITH CLOUDS RAIN AND INCREASING EAST WINDS.
LOCATIONS NORTH OF I-80 MAY SEE WITH EVAPORATIVE COOLING A MIX OF
SNOW BY MORNING...OR JUST A WET SNOW. THIS REMAINS A POOR CONFIDENCE
ON MIXED PRECIPITATION NORTH SECTIONS. THIS QUESTION SHOULD BE
RESOLVED NEXT 12-24 HOURS. LOCAL TOOLS DO SUPPORT SOME ACCUMULATIONS
MAY OCCUR ON EXPOSED SURFACES ATTM BUT AREA TEMPERATURES AT OR
SLIGHTLY ABOVE FREEZING TO LIMIT IMPACTS ON ROADWAYS.
WEDNESDAY THROUGH FRIDAY...PROLONGED PERIODS OF CLOUDY...COLD AND EPISODES
OF RAIN OR MOSTLY RAIN WITH A RISK OF A MIX NORTH SECTIONS OR EVEN
A WET SNOW BY FRIDAY AS SYSTEM MOVES EAST. HIGHS MOSTLY IN THE 40S
WITH LOWS IN THE 30S. REVIEW OF LOCAL FORECAST AREA TOOLS INDICATE
1 TO LOCALLY NEAR 2 INCHES OF RAIN OR MOSTLY RAIN OVER THIS PERIOD
REMAINS ON TRACK. THIS SYSTEM IS SLOWING DOWN WHICH MAY ALLOW FOR
EVEN MORE MOISTURE AND MAY RESULT IN EVEN SLIGHTLY HEAVIER AMOUNTS
OF RAIN AND EVEN A WET SNOW AS OPEN GULF MOISTURE HAS MORE TIME TO
POOL AHEAD OF THE FRONT. THIS SYSTEM BEARS CLOSE WATCHING DUE TO
ITS STRENGTH...CURRENT TRACK TO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 240 AM CDT SAT MAR 29 2014
STRATUS BASED AROUND 2000 TO 2500 FT AGL WILL CONTINUE TO LINGER OVER
ALL OF EASTERN IOWA AND NORTHWEST ILLINOIS THROUGH THE MORNING HOURS.
SOME CLEARING IS EXPECTED...BUT MAY TAKE UNTIL 18Z OR EVEN 20Z TO
GO SCATTERED OVER LOCATIONS SOUTH OF DBQ ALONG THE MISSISSIPPI RIVER.
MLI AND BRL ARE THUS KEPT IN MVFR CONDITIONS THIS MORNING. WINDS
WILL OTHERWISE BE VERY LIGHT AND VARIABLE AS HIGH PRESSURE PASSES
THROUGH THE AREA. VFR CONDITIONS ARE THEN LIKELY FROM LATE AFTERNOON
THROUGH THE OVERNIGHT AT ALL SITES WITH LIGHT WINDS BECOMING SOUTHERLY
TOWARD SUNRISE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
324 AM CDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 240 AM CDT SAT MAR 29 2014
AN UPPER LEVEL SHORTWAVE WITH SEVERAL EMBEDDED COMPACT VORT MAXIMA
WAS EVIDENT ON SATELLITE WV IMAGES MOVING THROUGH CENTRAL IA AND
WESTERN MO AT 07Z. AREA RADARS INDICATED A FEW WEAK ECHOES IN THE
LIFT AHEAD OF THIS FEATURE FROM SW WI ALONG THE MS RIVER TO W
CENTRAL IL. AREA OBSERVATIONS HAVE YET TO INDICATE ANY PRECIPITATION
REACHING THE GROUND FROM THESE WEAK RETURNS. AN INVERTED TROUGH AT
THE SURFACE...REACHING FROM THE CENTRAL IL INTO EAST CENTRAL
IA...WAS PROVIDING ENOUGH LOW LEVEL CONVERGENCE TO KEEP THE
WIDESPREAD STRATUS THAT NEVER LEFT THE AREA YESTERDAY IN PLACE. THE
00Z KDVN SOUNDING SHOWED AN ASSOCIATED SHALLOW LAYER OF MOISTURE
TRAPPED JUST BELOW AN INVERSION AND WEDGE OF DRY AIR ABOVE 900 MB.
UPSTREAM...A LARGE UPPER LOW WAS OFF THE BC COAST WITH A DOWNSTREAM
RIDGE AXIS MOVING THROUGH THE NORTHERN ROCKIES. AHEAD OF THIS UPPER
RIDGE...HIGH PRESSURE AT THE SURFACE REACHED FROM NEB INTO NORTHERN
MN. UNDER THIS RIDGE...SKIES WERE MAINLY CLEAR AND THE MUCH DRIER
AIRMASS FEATURED DEWPOINTS IN THE TEENS AND 20S...CONTRASTING TO THE
UPPER 20S TO LOWER 30S CURRENTLY OVER THE FORECAST AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 240 AM CDT SAT MAR 29 2014
MAIN CHALLENGE CENTERS ON HOW FAST CLOUDS WILL CLEAR TODAY AND THE
IMPACT ON TEMPERATURES IN THE SHORT TERM. THE ADVANCING UPSTREAM
UPPER RIDGE AND DEEPENING AND PHASING OF THE DOWNSTREAM TROUGH OVER
THE OHIO VALLEY TODAY WILL RESULT IN A DEVELOPING MORE FAVORABLE
SUBSIDENCE REGIME THAN YESTERDAY. HOWEVER...THIS APPEARS TO BE A
SLOW PROCESS...AND MAY NOT RESULT IN ANY SIGNIFICANT CLEARING UNTIL
AFTERNOON.
AT THE SURFACE...A DEEPENING LOW PRESSURE SYSTEM RIDING NORTHEAST
THROUGH KY AND TN WILL IS SHOWN KEEPING AT LEAST A WEAK CYCLONIC
CURVATURE IN THE SURFACE PRESSURE FIELD EXTENDING NORTHEAST INTO
EASTERN IA UNTIL MIDDAY. THE ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AND TRAPPED MOISTURE BELOW THE LINGERING INVERSION ALOFT...WILL KEEP
THE STRATUS HOLDING IN PLACE OVER MOST THE FORECAST AREA THIS
MORNING. THE BACK EDGE OF THE CLOUDS...CURRENTLY SLOWLY ADVANCING
E-SE ACROSS N CENTRAL AND FAR WESTERN IA WILL LIKELY COME TO A HALT
OVER CENTRAL IA INTO EASTERN IA THIS MORNING. FORECAST MODELS
CONTINUE TO STRUGGLE WITH THIS...AND AT THIS TIME ONLY THE RAP 900
MB RH FIELD SEEMS TO HAVE A GOOD HANDLE ON THIS TREND. WILL THUS KEEP
MOSTLY CLOUDY SKIES GOING THROUGH THE MORNING...THEN TRANSITION TO
MOSTLY SUNNY BY AFTERNOON AS THE SURFACE AND UPPER LEVEL RIDGE MOVE
OVERHEAD BRINGING SUBSIDENCE AND DRIER AIR. ACCOUNTING FOR THIS
DELAYED WARMING...AND WEAK MIXING UNDER THE RIDGE...HAVE HELD HIGH
TEMPERATURES AT THE LOWER END OF GUIDANCE...FROM THE MID 40S NORTH
TO LOWER 50S SOUTH.
TONIGHT...SKIES WILL START OUT CLEAR WITH ADVANCING HIGH CLOUDS
FOLLOWING PASSAGE OF THE UPPER RIDGE AXIS TOWARD MORNING. AT THE SURFACE...
INITIALLY LIGHT WINDS WILL TURN SOUTHERLY AND INCREASE TO AT LEAST 5
TO 10 KTS TOWARD MORNING AS A TROUGH MOVES INTO THE PLAINS. THIS
WOULD SUPPORT AN INITIAL COOL-DOWN AFTER SUNSET...THEN STEADY TO
POSSIBLY EVEN RISING TEMPERATURES TOWARD SUNRISE. WITH MOST MODELS
OVERALL TRENDING TOO MOIST IN THE LOWER LEVELS...HAVE GONE CLOSER TO
THE BETTER INITIALIZING ECMWF WITH ITS LOWER DEWPOINTS IN THE 20S
BEFORE THE RETURN FLOW SETS UP. THIS POINTS TOWARD LOWER MINS THAN
MOS...AND HAVE GONE WITH LOWS FROM THE MID 20S EAST TO LOWER 30S IN
THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 240 AM CDT SAT MAR 29 2014
MILD WITH A FAST MOVING DISTURBANCE MONDAY...THEN FAVORABLE SETUP
FOR SIGNIFICANT TO HEAVY PRECIPITATION MID TO LATE NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION AVERAGE WITH STILL QUESTIONS
ON PHASING OF PACIFIC ENERGY ARRIVING NEXT FEW DAYS. AGAIN POOR BL
ISSUES THAT ARE OFF BY 3-5 DEGREES FOR BOTH T AND T/D THAT MOS OR
OTHER ALGORITHMS ARE HAVING PROBLEMS HANDLING. TREND IS FOR A DEEPER
TROUGH INTO THE PACIFIC SW BY TUESDAY WHICH IS A GOOD REGIME FOR
MODERATE TO HEAVY PRECIPITATION...MOSTLY RAIN WITH STALLED FRONT
TO OUR SOUTH FOR PROLONGED UPGLIDE. VARIANCES CONTINUE WITH HI-RES ECMWF
BY FAR THE FURTHEST NORTH. RUN TO RUN TRENDS AND VARIANCES SUPPORTS
A MIX OF THE UKMET/GFS /GEM-NH AND TO DISREGARD THE HI-RES ECMWF.
TRENDS ARE FOR NORTH PORTIONS TO SEE AT LEAST A FEW PERIODS OF A
MIX OF RAIN AND WET SNOW WHICH WILL TAKE ANOTHER 24 HOURS TO BETTER
ASCERTAIN. THIS 2 TO 3 DAY EVENT WEDNESDAY INTO FRIDAY WILL BE THE
HEAVIEST PRECIPITATION EVENT...WIDESPREAD 1 TO 2 PLUS INCH AMOUNTS
SINCE LAST FALL. CONDITIONS OF THIS TYPE CONTINUE TO SUGGEST WILL
HELP REPLENISH THE MODESTLY DRY SOILS AND PREPARE THE GROUND FOR
SPRING.
SUNDAY...EXPECT MODERATE BL MIXING AND MODERATE SOUTHERLY WINDS OF UP
TO 15 TO 25+ PH IN THE AFTERNOON. TRENDS STILL SUPPORT HIGHS IN LOWER
TO MIDDLE 60S WITH AFTERNOON RH VALUES FALLING BELOW 50 PERCENT TO
LOCALLY NEAR 40 PERCENT. THIS INDICATES GFDI VALUES INTO VERY HIGH
CATEGORY FOR SEVERAL HOURS IN THE AFTERNOON...MAINLY WEST OF THE
MISSISSIPPI RIVER DUE TO LITTLE TO NO GREENING OF VEGETATION. THIS
WILL REMAIN IN THE HWO PRODUCT. SUNDAY NIGHT...SOUTH WINDS OF 10 TO
20 MPH TO MAKE FOR THE MILDEST NIGHT IN MANY MONTHS DESPITE FAIR SKIES
WITH LOWS IN THE MID TO UPPER 40S....TO AROUND 50F SOUTH.
MONDAY...NEXT VIGOROUS AND FAST MOVING STORM SYSTEM SIMILAR TO YESTERDAY/S.
IS SLIGHTLY SLOWER...KEEPING MID CHANCE POPS WITH SHOWERS AND ISOLATED
MAINLY PM STORMS. WINDS WILL BE STRONGER ALLOWING FOR LOWER PM DEWPOINTS.
MID LEVEL SHOWERS AND ISOLATED STORMS WITH BASES AOA 6K AGL. LOW FREEZING
LEVEL STILL SUGGESTS NON-SEVERE STORMS WITH SOME PEA HAIL POSSIBLE AS
ANY STORMS WOULD FIRE OVER CWA IN MID/LATE PM HOURS. RAISED HIGHS BY
2-3 DEGREES INTO THE MID/UPPER 60S. WINDS MID DAY SHOULD BECOME QUITE
WINDY APPROACHING WIND ADVISORY CRITERIA OF 20 TO 30 MPH WITH GUSTS
TO AROUND 40 MPH. RH VALUES SHOULD FALL TO AROUND 50 PERCENT THAT MAY
SUPPORT NEAR VERY HIGH CONDITIONS FOR FIRE WEATHER BUT SHOWERS/STORMS
SHOULD AMELIORATE A BIT ALONG WITH HIGHER RH VALUES. MONDAY NIGHT...SLIGHTLY
DELAYED TIMING OF COOL FRONTAL PASSAGE INTO MID/LATE EVENING AND GUSTY
NW WINDS TO LIMIT COOLING BY MORNING. THIS SUGGESTS MINS NEAR GUIDANCE
BLEND...OR UPPER 20S FAR NW TO MIDDLE 30S FAR SE SECTIONS.
TUESDAY...LITTLE CHANGE TO CURRENT FORECAST. COOLER AND MOSTLY FAIR
SKIES WITH HIGHS MOSTLY OF 45 TO 50 DEGREES AND LIGHT NE WINDS AHEAD
OF NEXT...LARGE...SLOW MOVING AND QUITE STRONG UPPER DISTURBANCE AND
DEEP TROUGH MOVING EAST FROM CALIFORNIA. TUESDAY NIGHT...INCREASING
CLOUDS STILL SUGGEST LOWS TO OCCUR NEAR OR BEFORE MIDNIGHT....THEN
RISING TOWARD MORNING WITH CLOUDS RAIN AND INCREASING EAST WINDS.
LOCATIONS NORTH OF I-80 MAY SEE WITH EVAPORATIVE COOLING A MIX OF
SNOW BY MORNING...OR JUST A WET SNOW. THIS REMAINS A POOR CONFIDENCE
ON MIXED PRECIPITATION NORTH SECTIONS. THIS QUESTION SHOULD BE
RESOLVED NEXT 12-24 HOURS. LOCAL TOOLS DO SUPPORT SOME ACCUMULATIONS
MAY OCCUR ON EXPOSED SURFACES ATTM BUT AREA TEMPERATURES AT OR
SLIGHTLY ABOVE FREEZING TO LIMIT IMPACTS ON ROADWAYS.
WEDNESDAY THROUGH FRIDAY...PROLONGED PERIODS OF CLOUDY...COLD AND EPISODES
OF RAIN OR MOSTLY RAIN WITH Q RISK OF A MIX NORTH SECTIONS OR EVEN
A WET SNOW BY FRIDAY AS SYSTEM MOVES EAST. HIGHS MOSTLY IN THE 40S
WITH LOWS IN THE 30S. REVIEW OF LOCAL FORECAST AREA TOOLS INDICATE
1 TO LOCALLY NEAR 2 INCHES OF RAIN OR MOSTLY RAIN OVER THIS PERIOD
REMAINS ON TRACK. THIS SYSTEM IS SLOWING DOWN WHICH MAY ALLOW FOR
EVEN MORE MOISTURE AND MAY RESULT IN EVEN SLIGHTLY HEAVIER AMOUNTS
OF RAIN AND EVEN A WET SNOW AS OPEN GULF MOISTURE HAS MORE TIME TO
POOL AHEAD OF THE FRONT. THIS SYSTEM BEARS CLOSE WATCHING DUE TO
ITS STRENGTH...CURRENT TRACK TO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 240 AM CDT SAT MAR 29 2014
STRATUS BASED AROUND 2000 TO 2500 FT AGL WILL CONTINUE TO LINGER OVER
ALL OF EASTERN IOWA AND NORTHWEST ILLINOIS THROUGH THE MORNING HOURS.
SOME CLEARING IS EXPECTED...BUT MAY TAKE UNTIL 18Z OR EVEN 20Z TO
GO SCATTERED OVER LOCATIONS SOUTH OF DBQ ALONG THE MISSISSIPPI RIVER.
MLI AND BRL ARE THUS KEPT IN MVFR CONDITIONS THIS MORNING. WINDS
WILL OTHERWISE BE VERY LIGHT AND VARIABLE AS HIGH PRESSURE PASSES
THROUGH THE AREA. VFR CONDITIONS ARE THEN LIKELY FROM LATE AFTERNOON
THROUGH THE OVERNIGHT AT ALL SITES WITH LIGHT WINDS BECOMING SOUTHERLY
TOWARD SUNRISE.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
205 AM EDT SAT MAR 29 2014
.UPDATE...
ISSUED AT 150 AM EDT SAT MAR 29 2014
UPDATED THE GRIDS TO FINE TUNE THE POP CHANCES THROUGH DAWN. ALSO
ADJUSTED THE T AND TD GRIDS PER THE LATEST OBS...TRENDS...AND NEAR
TERM MODEL DATA. THESE TWEAKS HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
UPDATE ISSUED AT 740 PM EDT FRI MAR 28 2014
LATEST HRRR AND RAP BOTH BACKING OFF ON PRECIPITATION CHANCES THROUGH
THE OVERNIGHT HOURS. THE EXCEPTION IS IN A NARROW CORRIDOR ALONG THE
STALLED OUT FRONTAL BOUNDARY DRAPED FROM JUST SOUTH OF
HUNTINGTON...AND NEARLY ALONG THE I-64 CORRIDOR. THESE SHOWERS HAVE
DEVELOPED AMIDST A CONVERGENCE ZONE...AND SOME INSTABILITY. THIS
ACTIVITY SHOULD WANE AS WE HEAD INTO THE LATE EVENING HOURS...LEAVING
THE AREA DRY THROUGH MUCH OF THE OVERNIGHT PERIOD. SOME RAIN MAY
CREEP INTO THE I-75 CORRIDOR TOWARDS DAWN AHEAD OF THE MAIN LOBE OF
ENERGY EXPECTED TO CROSS THE AREA SATURDAY MORNING. UNTIL THIS
HAPPENS...IT LOOKS LIKE A DRIER FORECAST IS ON TAP TONIGHT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 400 PM EDT FRI MAR 28 2014
A COLD FRONT HAS SLOWED ITS SOUTH AND EAST PROGRESS AS AN AREA OF LOW
PRESSURE IS BEGINNING TO TAKE SHAPE OVER TX IN RESPONSE TO THE NEXT
SHORTWAVE MOVING ACROSS THE PLAINS. THIS SHORTWAVE TROUGH WILL
GRADUALLY WORK EAST TO MS RIVER VALLEY AND ENTER THE LOWER OH VALLEY
TONIGHT AND THEN INTO THE EASTERN CONUS THROUGH THE END OF THE PERIOD.
THE SOUTHERN END OF THE TROUGH IS FORECAST TO CLOSE OFF AND MOVE
ACROSS THE AREA LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT. THE SFC
LOW IS EXPECTED TO TRACK TO THE CUMBERLAND PLATEAU IN TN BY DAWN ON
SATURDAY. THE 12Z GFS IS GENERALLY THE STRONGEST WITH THE SFC LOW AT
THAT POINT. THE SFC LOW SHOULD MOVE ACROSS THE SOUTHEAST PART OF THE
AREA ON SATURDAY MORNING AND DEEPEN TO ABOUT 995 MB PER THE 12Z ECMWF
AND 12Z GFS AS THE UPPER LOW DEVELOPS AND REACH THE DELMARVA BY THE
END OF THE PERIOD.
DESPITE THE MID LEVEL HEIGHT RISES CAPPING OFF CONVECTION THIS AFTERNOON
FROM BRIEF SHORTWAVE RIDGING...THERE IS ENOUGH LOW LEVEL INSTABILITY
FOR EXTENSIVE CU AND STRATOCU AND SOME SHOWERS. THESE FEW SHOWERS
HAVE RECENTLY DEVELOP NEAR THE STALLING BOUNDARY AS MODEL GUIDANCE
HAD SUGGESTED. SOME ISOLATED SHOWERS WILL REMAIN POSSIBLE THIS
EVENING...BEFORE MOISTURE AND LIFT INCREASE AHEAD OF THE UPPER LEVEL
TROUGH AND SFC WAVE TO TRACK NORTHEAST INTO THE TN VALLEY AND THEN
INTO THE REGION BY EARLY ON SATURDAY. THE 12Z ECMWF AND GFS GUIDANCE
SUGGEST VERY LITTLE IF ANY MEASURABLE PRECIPITATION TONIGHT WITH SOME
DOWNSLOPE FLOW ACROSS MUCH OF THE AREA. HOWEVER... THE NAM AND 9Z AND
15Z SREF WERE IN THE LIKELY TO CAT RANGE IN MOST AREAS ACROSS THE
REGION. PERSISTENCE AND ISC COLLABORATION LED TO CATEGORICAL POPS
LATE IN ALL BUT THE BIG SANDY REGION. QPF TONIGHT WILL BE LIGHTER AND
MUCH MORE SIGNIFICANT WELL WEST OF THE REGION AND WEST OF THE
ANTICIPATED SFC LOW TRACK.
AS THE SFC LOW TRACKS INTO WV THROUGH EARLY SAT AFTERNOON SOME COLDER
AIR WILL BEGIN TO BE WRAPPED SOUTHEAST TOWARD THE REGION. A BAND OF
SHOWERS OR RAIN WILL SHIFT EAST INTO EASTERN KY BY THE DAY ON
SATURDAY. THIS SHOULD LEAD TO THE MOST WIDESPREAD PRECIP ACROSS THE
REGION ON SATURDAY MORNING...WITH SOME DRY SLOTTING IN THE AFTERNOON
TO EARLY EVENING...ESPECIALLY IN THE SOUTH AND SOUTHEAST. ELEVATED
INSTABILITY DOES LINGER INTO SAT AM...SO AN ISOLATED RUMBLE OR TWO OF
THUNDER CANNOT BE RULED OUT. TEMPERATURES WILL BE WARMEST IN THE AM
AS THE SFC LOW MOVES ACROSS THE REGION AND THEN TEMPS WILL BEGIN TO
DROP OFF DURING SAT AFTERNOON. TEMPS SHOULD REACH THE UPPER 30S TO
LOW 40S ACROSS THE NORTH AND HIGHEST TERRAIN BY LATE AFTERNOON.
AS THE SOUTHERN PORTION OF THE SHORTWAVE TROUGH CLOSES OFF INTO A
CLOSED UPPER LEVEL LOW AND MOVES EAST INTO THE CENTRAL AND SOUTHERN
APPALACHIANS... FURTHER COLD AIR ADVECTION AND INSTABILITY AS WELL AS
UPSLOPE FLOW WILL LEAD TO ANOTHER ROUND OF SHOWERS MOVING ACROSS THE
AREA FROM SAT EVENING INTO WELL INTO SAT NIGHT. THE NON NAM GUIDANCE
SUGGESTS SOME DECENT QPF...WHILE THE THERMAL PROFILE GRADUALLY MOVES
TOWARD ONE SUPPORTIVE OF SNOW SHOWERS...FIRST ACROSS THE FAR NW AND
HIGHEST TERRAIN NEAR THE VA LINE AND THEN INTO THE LOWER
ELEVATIONS...POSSIBLY BEFORE THE SHOWER CHANCES END. THE COLLING
WOULD COME FROM A COMBINATION OF COLD ADVECTION...COOLING FROM LIFT
AND SOME WETBULBING. WITH THE UPPER LOW TRACKING ACROSS THE AREA AT
NIGHT...AND ANY SNOW GENERALLY FALLING AT NIGHT AS WELL SOME
ACCUMULATION WILL BE POSSIBLE. MOST LOCATIONS WILL NOT GET MORE THAN
A DUSTING... IF THAT FROM THIS. HOWEVER...LIGHT ACCUMULATIONS WILL BE
POSSIBLE...PARTICULARLY RIDGES AT 2000 FEET AND ABOVE. AMOUNTS AT
THESE HIGHEST ELEVATIONS COULD EXCEED 1 INCH WITH THE TOP OF BLACK
MTN OR PINE MTN AND PERHAPS THE FLATWOODS AREA OF PIKE COUNTY GETTING
AS MUCH AS 2 TO 3 INCHES.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 323 PM EDT FRI MAR 28 2014
THE EXTENDED FORECAST PERIOD BEGINS WITH THE MODELS IN VERY GOOD
AGREEMENT. ON SUNDAY THE WILL BE AN UPPER LOW OVER SOUTH CENTRAL
VIRGINIA. AT THE SURFACE...THE WRAP AROUND MOISTURE SHOULD SHOULD BE
MOVING OUT OF THE AREA AND THE THE PRECIPITATION SHOULD BE ENDING.
THE UPPER LOW WILL CONTINUE MOVING TO THE NORTHEAST AND THE NEXT
SYSTEM WILL START MOVING TOWARD THE AREA. AS THE SYSTEM APPROACHES
ON TUESDAY NIGHT...AN UPPER LOW WILL START DIGGING IN OVER THE WEST
COAST. THIS WILL TEND THE KEEP THE FRONT FAIR STATIONARY NEAR
EASTERN KENTUCKY. AT THIS TIME THE FRONT WILL BE FAIRLY WEAK AND
IT WILL RESULT MOSTLY IN CLOUDS. THERE IS QUITE A BIT OF UNCERTAINTY
AS TO EXACTLY WHERE THE FRONT WILL STALL OUT. AS THE UPPER TROUGH
OUT WEST CONTINUES TOWARD THE AREA...THE FRONT WILL DEFINITELY BE TO
THE NORTH OF THE AREA AND IT WILL KEEP EASTERN KENTUCKY IN THE WARM
SECTOR. THE FRONT WILL BE MOVING VERY SLOWLY INTO AND THROUGH THE
AREA AS WAVE DEVELOP ON THE FRONT OVER THE SOUTH CENTRAL PLAINS AND
KEEP THE FRONT TO THE WEST OF THE AREA. THIS WILL KEEP WARM UNSTABLE
AIR OVER EASTERN KENTUCKY AND WILL ALLOW SOME ISOLATED THUNDERSTORMS
TO ACCOMPANY THE RAIN. THE FRONT IS EXPECTED TO MOVE ACROSS THE AREA
ON THURSDAY NIGHT. BY THE END OF THE PERIOD...THERE MODELS ARE
DIFFERING...SO THE TIMING OF THIS FRONT COULD CHANGE 6-18 HOURS BY
THE TIME IT GETS HERE. THIS WILL KEEP THE HIGH TEMPERATURES NEAR 70
THROUGH THE EXTENDED PERIOD. ADJUSTED THE MODEL BLEND TOWARD THE NEW
ECMWF.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 205 AM EDT SAT MAR 29 2014
DOWNSLOPING SOUTHEAST WINDS WILL LIKELY KEEP ANY LOWER CLOUDS AT BAY
AND ALLOW VFR CONDITIONS TO CONTINUE THROUGH THE REMAINDER OF THE
NIGHT. THE EXCEPTION COULD BE IN SOUTH CENTRAL KENTUCKY...WHERE LESS
INFLUENCE ON DOWNSLOPING FLOW MAY MEAN A PERIOD OF MVFR CIGS TOWARD
DAWN. THIS WOULD MAINLY IMPACT KSME AND PERHAPS KLOZ IN ADVANCE OF
THE SHOWERS OF THE NEXT SYSTEM. RAIN LOOKS LIKE IT SHOULD NOT AFFECT
TAF SITES UNTIL AFTER DAWN. AS THE RAIN COMES IN LATER IN THE
MORNING...CEILINGS WILL LOWER TO MVFR BEFORE LIKELY REACHING IFR BY
MIDDAY WHEN THE LOW LEVELS SATURATE. THE RAIN SHOWERS WILL CONTINUE
THROUGH SATURDAY EVENING WITH SOME SNOW MIXING IN AFTER DARK AT MOST
SITES. WINDS WILL BE RATHER LIGHT THROUGH THE BULK OF THE PERIOD. THE
VARIABLE DIRECTION BECOME SOUTH AFTER SUNRISE AND THEN THE WINDS
SWITCH TO THE WEST AROUND MIDDAY BEFORE BECOMING NORTHWEST AND
PICKING UP TO NEAR 10 KTS FOR THE REMAINDER OF THE PERIOD AS A
DEEPENING AREA OF LOW PRESSURE MOVES PAST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JP
LONG TERM...JJ
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
354 AM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAR 29 2014
A WARM DRY SURGE IS READY TO GO TODAY. THE SOURCE REGION FOR THIS
WARM AIR IS THE SOUTH CENTRAL ROCKIES AND THE RAP MODEL SHOWS
SOUTHWEST WINDS DRAWING THIS AIR THROUGH THE FCST AREA...GENERALLY
ALONG AND WEST OF HIGHWAY 83.
NEARLY FULL SUN IS EXPECTED AS THE NEAREST CIRRUS IS OVER THE TETONS
AND BIG HORNS. THE GFS HOWEVER SHOWS CIRRUS DEVELOPING THIS AFTN OFF
THE LARAMIE RANGE AND THIS IS SUPPORTED BY THE ECM WHICH GENERALLY
HAS GOOD SKILL WITH HIGH CLOUDS. STILL...THE SUPER ENSEMBLE
TEMPERATURE FORECAST PRODUCES HIGHS IN THE UPPER 60S TO NEAR 70
WHICH WERE MARKED UP TO LOWER 70S IN MANY AREAS GIVEN THE VERY DEEP
MIXING SHOWN BY THE RAP MODEL.
SOUTHWEST WINDS INCREASE TO 15 TO 25 MPH AND A BLEND OF THE
NAM...RAP AND GFS WIND GUST PRODUCTS PRODUCED WIND GUSTS TO 35 MPH.
FOR TONIGHT...THE THERMAL RIDGE FORECAST TO MOVE OFF THE ROCKIES
TODAY CONTINUES TO BUILD ACROSS THE FORECAST AREA. LOWS SHOULD ONLY
FALL TO THE MID 30S TO LOWER 40S WITH DECOUPLING POSSIBLE OVER
SOUTHWEST NEB FOR LOCALLY COOLER LOWS GIVEN THE VERY DRY
ENVIRONMENTAL CONDITIONS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAR 29 2014
UPPER LEVEL RIDGE TO BREAK DOWN ON SUNDAY AS AN UPPER TROUGH
ADVANCES NORTHEAST FROM THE GREAT BASIN TOWARD THE CENTRAL PLAINS.
WITH THE APPROACH OF THE UPPER TROUGH...CYCLOGENESIS WILL COMMENCE
OFF THE LEE OF THE ROCKIES WITH SUBSEQUENT DEEPENING OF THE
SURFACE LOW THROUGH THE DAY. THE LOW SHOULD REMAIN FOCUSED ALONG
OR NEAR THE CHEYENNE RIDGE SUNDAY...WHICH AS IT DEEPENS WILL ALLOW
FOR BACKED SURFACE WINDS TO THE SOUTHEAST. DESPITE HIGH
TEMPERATURES WELL INTO THE 70S ACROSS THE CENTRAL SANDHILLS AND
POINTS SOUTH /MAYBE A FEW 80S AS WELL/...THIS BACKED SURFACE FLOW
WILL ALLOW FOR A GREATER MOISTURE TRAJECTORY OFF THE GULF...RATHER
THAN THE DIRECT DOWNSLOPE FLOW FROM SOUTH CENTRAL COLORADO. TD/S
ARE ANTICIPATED TO RISE SOME...BUT STEEP LOW-MID LEVEL LAPSE RATES
WILL CONTINUE TO MIX DRY ALOFT TO THE SURFACE...EFFECTIVELY
KEEPING MINIMUM RELATIVE HUMIDITIES NEAR CRITICAL THRESHOLDS.
ATTM...SOUTHWEST NEBRASKA AND THE CENTRAL SANDHILLS ARE EXPECTED
TO SEE RH IN THE 15 PERCENT RANGE BY EARLY AFTERNOON...BUT SHOULD
INCREASE SLIGHTLY TOWARD EVENING. EXTENDING FROM THE LOW WILL BE
AN INVERTED SURFACE TROUGH...WHICH WOULD PRODUCE A WEAKNESS IN THE
WIND FIELD. AVAILABLE MODEL GUIDANCE DOES NOT SUPPORT RFW WIND
CRITERIA ATTM ACROSS THE CENTRAL SANDHILLS. HOWEVER STRONG MIXING
DUE TO VERY STEEP LOW-MID LEVEL LAPSE RATES WOULD ALLOW FOR
DOWNWARD MOMENTUM TRANSFER. GUSTS IN EXCESS OF 25 MPH ARE
INDICATED BY BUFR SOUNDINGS WHERE THE RH MINIMUM EXISTS /SOUTHWEST
NEBRASKA. AN ADDITIONAL RED FLAG WARNING IS ANTICIPATED FOR
SUNDAY. FOR THIS WILL ISSUE A FIRE WEATHER WATCH WHERE CONFIDENCE
IS HIGH /FIRE ZONES 210 AND 219/ ON SEEING RFW CRITERIA. STEEP
LAPSE RATES ASSOCIATED WITH AN EASTWARD ADVECTING EML WILL
OVERSPREAD MUCH OF THE CENTRAL HIGH PLAINS LATE AFTERNOON/EARLY
EVENING RESULTING IN WEAK INSTABILITY ALOFT. HIGH BASED CONVECTION
IS POSSIBLE...IF STORMS FIRE...SURFACE TD/T SPREADS OF 40 DEGREES
OR WOULD SUGGEST THE POTENTIAL FOR STRONG TSTM OUTFLOW WITH LITTLE
RAINFALL. NOT ANTICIPATING A LAL OF 6...BUT TROUBLESOME
NONETHELESS. ADDITIONAL CONVECTION IS POSSIBLE INTO THE EVENING
HOURS AS THE TROUGH AND ASSOCIATE COLD FRONT CROSS THE CENTRAL
PLAINS...BUT ONCE AGAIN MOISTURE INITIALLY IS LACKING...SO WETTING
RAINS WILL BE ISOLATED AT BEST. BEYOND SUNDAY EVENING THE FORECAST
GETS TRICKY...ESPECIALLY WHEN CONSIDERING THE POTENTIAL IMPACTS OF
THE IMPENDING LATE WINTER STORM. ATTM...THERE/S SUFFICIENT
AGREEMENT IN THE MODELS TO SUGGEST RAIN CHANGING OVER TO SNOW
EARLY ON MONDAY ACROSS OUR NORTHERN ZONES AS THE MAIN TROUGH DRAGS
MODIFIED ARCTIC AIR SOUTH INTO THE CWA. IN TERMS OF
IMPACTS...TEMPERATURES AT LEAST INITIALLY WILL REMAIN IN THE LOWER
30S...AND GIVEN THE WARM WEEKEND...SNOW MAY STRUGGLE TO ACCUMULATE
ON PAVED SURFACES...ESPECIALLY TRUE IF THE BRUNT OF THE SNOW
OCCURS AFTER SUNRISE. BUT...WINDS ON THE BACKSIDE OF THE EJECTING
SFC LOW WILL BE EXTREMELY GUSTY...WITH THE POTENTIAL OF 35 MPH
GUSTS /OR HIGHER/ ACROSS NORTH CENTRAL NEBRASKA ON MONDAY.
VISIBILITY WILL BE SIGNIFICANTLY REDUCED WHEN SNOW IS FALLING.
WINTER HEADLINES ARE POSSIBLE ON MONDAY ACROSS NORTHERN
NEBRASKA...WITH THE GREATEST IMPACTS FOCUSED ALONG AND NORTH OF
THE HIGHWAY 20 CORRIDOR. WILL INCREASE POPS IN THIS AREA INTO THE
LOW LIKELY RANGE WITH THIS FORECAST ISSUANCE. BEYOND MONDAY...THE
PATTERN REMAINS ACTIVE THROUGHOUT THE ENTIRE NEXT WORK WEEK AS
QUASI-ZONAL FLOW SLOWLY TRANSITIONS TO SOUTHWESTERLY WITH THE
APPROACH OF THE NEXT LONGWAVE WESTERN CONUS TROUGH. THIS PATTERN
FAVORS SEASONAL...TO SLIGHTLY BELOW AVERAGE TEMPERATURES THROUGH
AT LEAST NEXT THURSDAY. IN ADDITION...AS THE NEXT UPPER TROUGH
DIGS ACROSS THE GREAT BASIN MID-WEEK...A COLD FRONT WILL REMAIN
FIXED SOUTH OF THE CWA...WHICH WILL GENERALLY PROVIDE FOR UPSLOPE
FLOW AND CONSIDERABLE CLOUDINESS EACH DAY. PRECIPITATION WILL
REMAIN IN THE FORECAST AS WELL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1244 AM CDT SAT MAR 29 2014
LOW CEILINGS IN NORTH CENTRAL NEBRASKA WILL CLEAR OUT AFTER 07Z.
THEN...IN CENTRAL AND SOUTHWEST NEBRASKA...PATCHY FOG CAN BE
EXPECTED. THE EVENING LBF SOUNDING WAS SHOWING UNIFORM MOISTURE IN
THE LAYER JUST ABOVE THE SURFACE AND...WITH TEMPERATURES FALLING TO
THE UPPER TEENS OR AROUND 20...THE PROBABILITY OF FOG INCREASES IN
THE PLATTE RIVER VALLEY. FOR THE LBF AREA...OPEN WATER ON THE NEARBY
WETLANDS WILL PROBABLY FAVOR PATCHY FOG THAT COULD GIVE VISIBILITY
OF 1/2SM OR LOWER. HOWEVER...OUR CONFIDENCE IS NOT HIGH THAT IT WILL
BE THAT LOW...SO WE WILL KEEP THE PREVAILING AT 3SM BCFG WITH
TEMPORARY CONDITIONS TO 1SM. NO LOW OR MIDDLE CLOUDS ARE
EXPECTED...SO THE FOG/MIST WILL LIFT OUT FAIRLY QUICKLY AFTER
SUNRISE.
&&
.FIRE WEATHER...
ISSUED AT 354 AM CDT SAT MAR 29 2014
THE RAP AND HRRR MODELS SHOW DEWPOINTS FALLING INTO THE TEENS TODAY.
THE MODEL CONSENSUS SHOWS SOUTHWEST WINDS INCREASING TO 15 TO 25 MPH
THIS AFTERNOON. A BLEND OF THE NAM...RAP AND GFS WIND GUST PRODUCTS
PRODUCED GUSTS TO 35 MPH THIS AFTERNOON ALSO.
THE SOURCE REGION FOR THIS DRY AIR IS THE SCNTL ROCKIES WHERE DEW
POINTS ARE CURRENTLY IN THE SINGLE DIGITS. THE MODELS PRODUCE
SOUTHWEST WINDS OFF THE ROCKIES TODAY WHICH WILL CARRY THIS DRY AIR
INTO THE FCST AREA WHILE TEMPERATURES RISE INTO THE LOWER 70S FOR RH
VALUES FALLING INTO THE SINGLE DIGITS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM
CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-209-210-219.
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR NEZ210-219.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
330 AM EDT SAT MAR 29 2014
.SYNOPSIS...A STRONG STORM SYSTEM WILL TRACK EASTWARD THROUGH THE
REGION TODAY THROUGH SUNDAY. HIGH PRESSURE WILL BUILD INTO THE AREA
SUNDAY NIGHT THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY/...
AS OF 300 AM SATURDAY...
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME
THREAT... AND WITH EXTENT/SEVERITY LIKELY LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE.
FOR SUNDAY: EXPECT MOSTLY CLOUDY SKIES TO HOLD PARTICULARLY OVER THE
NRN CWA AS THE LOW ALOFT SHIFTS OVER THE REGION. THE DEEPENING
SURFACE LOW JUST TO OUR NE WILL GENERATE A TIGHT MSLP GRADIENT
ACROSS NC... AND EXPECT WINDS TO BE SUSTAINED FROM THE WNW OR NW AT
15-20 MPH (HIGHEST IN THE WEST WHERE SUBSIDENCE WILL BE STRONGEST
WITHIN 100-120 M HEIGHT RISES... AND LOWER NE WHERE MIXING HEIGHTS
WILL BE LOWER)... WITH GUSTS OF 20-30 MPH... BELOW WIND ADVISORY
CRITERIA BUT THIS RISK WILL STILL NEED TO BE WATCHED. THE LOW LEVELS
DO DRY OUT WITH DOWNSLOPE FLOW BUT THIS RELATIVELY DRY LAYER WILL BE
SHALLOW... AND WE MAY STILL SEE SOME ISOLATED PATCHY LIGHT RAIN OVER
THE NRN CWA IN THE MORNING INTO EARLY AFTERNOON. WITH PLENTIFUL
CLOUDINESS... BRISK NW WINDS... COLD AIR ADVECTION... AND LOW LEVEL
THICKNESSES EXPECTED TO BE AROUND 30 M BELOW NORMAL... EXPECT CHILLY
HIGHS FROM THE UPPER 50S TO LOWER 60S... A SLIGHT DOWNWARD BUMP FROM
EARLIER FORECAST HIGHS. -GIH
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...
AS THE UPPER LOW OVER THE DELMARVA LATE SUNDAY DEPARTS OFF TO THE
NORTHEAST...CLOUD COVER ASSOCIATED WITH ITS COMMA HEAD WRAP AROUND
MOISTURE WILL DIMINISH BY MIDNIGHT. CLEARING SKIES AND SLOWLY
WEAKENING WINDS WILL ALLOW TEMPS TO DIP INTO THE 30S. BASED ON SOME
GUIDANCE...ITS POSSIBLE THAT SOME AREAS OVER THE WESTERN PIEDMONT
WILL APPROACH FREEZING BY MONDAY MORNING. RIGHT NOW IT APPEARS A
LIGHT WIND AND DRYING WILL PREVENT WIDESPREAD FROST.
THE SHOT OF COLDER AIR LOOKS TO BE VERY BRIEF AS A SHORTWAVE RIDGE
AND SURFACE HIGH PRESSURE BUILD OVER THE REGION...AND BEGIN AN
EVOLUTION INTO A PERSISTENT RIDGE OVER THE SOUTHEAST US. WITH A
LIGHT NORTHWEST WIND AND NEUTRAL THERMAL ADVECTION...LOW LEVEL
THICKNESSES AROUND 1320M MONDAY MORNING SUPPORT MET MOS GUIDANCE
MORE SO THAN THE MAV MOS...UPPER 60S NORTHEAST TO AROUND 70
SOUTHWEST. LOWS MONDAY NIGHT 39-44.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...
A RIDGE WILL DEVELOP OVER THE SOUTHEAST BY TUESDAY IS IS FORECAST TO
PERSIST THROUGH MUCH OF THE WEEK. THE PRIMARY STORM TRACK WILL BE
THROUGH THE MIDWEST AND GREAT LAKES REGION...WITH A WEAK FRONT
EXPECTED TO MOVE INTO THE MID-ATLANTIC STATES LATE TUESDAY AND THEN
WASH OUT WITHOUT HAVING MUCH...IF ANY IMPACT ON CENTRAL NC. MEDIUM
RANGE MODELS SHOW THE RIDGE HOLDING STRONG UNTIL LATE IN THE
WEEK...WHEN THE RIDGE FINALLY BREAKS DOWN AND A FRONTAL ZONE PUSHES
EAST INTO CENTRAL NC FRIDAY/FRIDAY NIGHT.
THIS PATTERN SUPPORTS A MUCH WARMER PERIOD FOR CENTRAL NC...WITH
THICKNESSES AS MUCH AS 20-30M ABOVE NORMAL AND HIGHS IN THE 70S OR
EVEN 80 IN THE SOUTHEAST BY WED/THURS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 100 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
00Z TONIGHT... AND POTENTIALLY THROUGH THE END OF THE TAF VALID
PERIOD AT 06Z. A DEEP MOIST FLOW FROM THE SOUTH AND SW... AHEAD OF A
STRENGTHENING STORM SYSTEM NOW MOVING THROUGH MS AND WRN TN... WILL
BRING IFR/LIFR CONDITIONS AND PERIODS OF MOSTLY LIGHT RAIN THROUGH
DAYBREAK. WE SHOULD SEE A BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN
THROUGH MUCH OF THE MORNING HOURS... MOST LIKELY FROM 11Z TO 16Z...
BUT CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME. THEN STARTING SOON AFTER 16Z... A LINE OF SHOWERS AND
THUNDERSTORMS IS EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC
THROUGH THE AFTERNOON HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
22Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH THIS EVENING. WINDS WILL SHIFT TO BE FROM THE NW WITH THE
COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT INT/GSO AND BETWEEN 04Z
AND 06Z AT RDU.
LOOKING BEYOND 06Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NCZ007>009-
021>025-038>040-073-074-083.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
325 AM EDT SAT MAR 29 2014
.SYNOPSIS...A STRONG STORM SYSTEM WILL TRACK EASTWARD THROUGH THE
REGION TODAY THROUGH SUNDAY. HIGH PRESSURE WILL BUILD INTO THE AREA
SUNDAY NIGHT THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY/...
AS OF 300 AM SATURDAY...
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME
THREAT... AND WITH EXTENT/SEVERITY LIKELY LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE.
FOR SUNDAY: EXPECT MOSTLY CLOUDY SKIES TO HOLD PARTICULARLY OVER THE
NRN CWA AS THE LOW ALOFT SHIFTS OVER THE REGION. THE DEEPENING
SURFACE LOW JUST TO OUR NE WILL GENERATE A TIGHT MSLP GRADIENT
ACROSS NC... AND EXPECT WINDS TO BE SUSTAINED FROM THE WNW OR NW AT
15-20 MPH (HIGHEST IN THE WEST WHERE SUBSIDENCE WILL BE STRONGEST
WITHIN 100-120 M HEIGHT RISES... AND LOWER NE WHERE MIXING HEIGHTS
WILL BE LOWER)... WITH GUSTS OF 20-30 MPH... BELOW WIND ADVISORY
CRITERIA BUT THIS RISK WILL STILL NEED TO BE WATCHED. THE LOW LEVELS
DO DRY OUT WITH DOWNSLOPE FLOW BUT THIS RELATIVELY DRY LAYER WILL BE
SHALLOW... AND WE MAY STILL SEE SOME ISOLATED PATCHY LIGHT RAIN OVER
THE NRN CWA IN THE MORNING INTO EARLY AFTERNOON. WITH PLENTIFUL
CLOUDINESS... BRISK NW WINDS... COLD AIR ADVECTION... AND LOW LEVEL
THICKNESSES EXPECTED TO BE AROUND 30 M BELOW NORMAL... EXPECT CHILLY
HIGHS FROM THE UPPER 50S TO LOWER 60S... A SLIGHT DOWNWARD BUMP FROM
EARLIER FORECAST HIGHS. -GIH
&&
.SHORT TERM / /...
AS OF 330 PM FRIDAY...
TO BE UPDATED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...
SUNDAY NIGHT AND MONDAY WILL BRING CLEAR/SUNNY/MILD WEATHER AS HIGH
PRESSURE (OF PACIFIC ORIGIN) MOVES OVERHEAD. LOWS 35-42. HIGHS 67-
72.
TUESDAY THROUGH THURSDAY NIGHT... MID AND UPPER LEVEL RIDGING WILL
LEAD TO A MUCH WARMER PERIOD FOR CONSECUTIVE DAYS. THE MAIN STORM
TRACK FROM THE PLAINS TO THE GREAT LAKES INTO SE CANADA WILL BE FAR
ENOUGH AWAY TO KEEP ANY POP OUT OF THE FORECAST. THE TEMPERATURES
SHOULD WARM WELL INTO THE 70S (WITH LOWER 80S POSSIBLE IN THE
SANDHILLS MID-WEEK) WITH THE LOW LEVEL SW FLOW. LOWS WARM FROM 40-45
TUE... INTO THE LOWER TO MID 50S THU.
THE NEXT SIGNIFICANT WEATHER MAKER SHOULD HOLD OFF UNTIL THURSDAY
NIGHT AND/OR FRIDAY ASSOCIATED WITH STORM TRACK FROM THE SOUTHERN
PLAINS TO THE OHIO VALLEY... AND A TRAILING COLD FRONT THE SHOULD
EDGE TO NEAR THE APPALACHIANS BY 12Z/FRIDAY... AND PUSH EAST ACROSS
THE REGION FRIDAY. WE WILL PLACE A LOW END CHANCE POP IN THE
FORECAST THU NIGHT AND FRIDAY WITH INCREASING CLOUDINESS. LOWS 55-
62. HIGHS FRIDAY GENERALLY 70-75 DEPENDING ON TIMING OF THE FRONT
AND ASSOCIATED SHOWER CHANCES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 100 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
00Z TONIGHT... AND POTENTIALLY THROUGH THE END OF THE TAF VALID
PERIOD AT 06Z. A DEEP MOIST FLOW FROM THE SOUTH AND SW... AHEAD OF A
STRENGTHENING STORM SYSTEM NOW MOVING THROUGH MS AND WRN TN... WILL
BRING IFR/LIFR CONDITIONS AND PERIODS OF MOSTLY LIGHT RAIN THROUGH
DAYBREAK. WE SHOULD SEE A BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN
THROUGH MUCH OF THE MORNING HOURS... MOST LIKELY FROM 11Z TO 16Z...
BUT CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME. THEN STARTING SOON AFTER 16Z... A LINE OF SHOWERS AND
THUNDERSTORMS IS EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC
THROUGH THE AFTERNOON HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
22Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH THIS EVENING. WINDS WILL SHIFT TO BE FROM THE NW WITH THE
COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT INT/GSO AND BETWEEN 04Z
AND 06Z AT RDU.
LOOKING BEYOND 06Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NCZ007>009-
021>025-038>040-073-074-083.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
305 AM EDT SAT MAR 29 2014
.SYNOPSIS...A STRONG STORM SYSTEM WILL TRACK EASTWARD THROUGH THE
REGION TODAY THROUGH SUNDAY. HIGH PRESSURE WILL BUILD INTO THE AREA
SUNDAY NIGHT THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY/...
AS OF 300 AM SATURDAY...
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME
THREAT... AND WITH EXTENT/SEVERITY LIKELY LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE. -GIH
FROM 300 PM FRIDAY:
THE FORECAST TRACK OF THE MID/UPPER SUNDAY WAS STILL VARIABLE WITHIN
THE MODEL OUTPUT. THE CONSENSUS IS FOR A TRACK EASTWARD FROM THE
CENTRAL APPALACHIANS ALONG OR NEAR THE NC/VA BORDER REGION DURING
SUNDAY MORNING... THEN SHIFTING OFFSHORE SUNDAY AFTERNOON. WITH THIS
TRACK... AND WITH THE SURFACE COLD FRONT EXPECTED TO BE OFFSHORE
AROUND 12Z/SUNDAY... CENTRAL NC IS EXPECTED TO BE IN THE DRY SLOT
BEGINNING AROUND DAYBREAK. THERE MAY STILL BE A RESIDUAL SHOWER
CHANCE... MAINLY ALONG AND EAST OF I-95 EARLY IN THE MORNING.
OTHERWISE... UNLESS THE MID LEVEL CIRCULATION COMES FARTHER SOUTH...
THERE SHOULD BE LITTLE IN THE WAY OF RAIN CHANCES. BY AFTERNOON...
NVA AND DOWNSLOPE SINKING IN THE MEAN WNW FLOW IN THE REAR OF THE
STORM WILL LEAD TO CLEARING/WINDY/MILD CONDITIONS. HIGHS SUNDAY
SHOULD TOP OUT IN THE LOWER 60S NW TO NEAR 70 IN THE SE. NW WINDS AT
15-25 MPH WITH GUSTS TO 30 MPH APPEAR LIKELY. -PWB
&&
.SHORT TERM / /...
AS OF 330 PM FRIDAY...
TO BE UPDATED.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 145 PM FRIDAY...
SUNDAY NIGHT AND MONDAY WILL BRING CLEAR/SUNNY/MILD WEATHER AS HIGH
PRESSURE (OF PACIFIC ORIGIN) MOVES OVERHEAD. LOWS 35-42. HIGHS 67-
72.
TUESDAY THROUGH THURSDAY NIGHT... MID AND UPPER LEVEL RIDGING WILL
LEAD TO A MUCH WARMER PERIOD FOR CONSECUTIVE DAYS. THE MAIN STORM
TRACK FROM THE PLAINS TO THE GREAT LAKES INTO SE CANADA WILL BE FAR
ENOUGH AWAY TO KEEP ANY POP OUT OF THE FORECAST. THE TEMPERATURES
SHOULD WARM WELL INTO THE 70S (WITH LOWER 80S POSSIBLE IN THE
SANDHILLS MID-WEEK) WITH THE LOW LEVEL SW FLOW. LOWS WARM FROM 40-45
TUE... INTO THE LOWER TO MID 50S THU.
THE NEXT SIGNIFICANT WEATHER MAKER SHOULD HOLD OFF UNTIL THURSDAY
NIGHT AND/OR FRIDAY ASSOCIATED WITH STORM TRACK FROM THE SOUTHERN
PLAINS TO THE OHIO VALLEY... AND A TRAILING COLD FRONT THE SHOULD
EDGE TO NEAR THE APPALACHIANS BY 12Z/FRIDAY... AND PUSH EAST ACROSS
THE REGION FRIDAY. WE WILL PLACE A LOW END CHANCE POP IN THE
FORECAST THU NIGHT AND FRIDAY WITH INCREASING CLOUDINESS. LOWS 55-
62. HIGHS FRIDAY GENERALLY 70-75 DEPENDING ON TIMING OF THE FRONT
AND ASSOCIATED SHOWER CHANCES.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 100 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
00Z TONIGHT... AND POTENTIALLY THROUGH THE END OF THE TAF VALID
PERIOD AT 06Z. A DEEP MOIST FLOW FROM THE SOUTH AND SW... AHEAD OF A
STRENGTHENING STORM SYSTEM NOW MOVING THROUGH MS AND WRN TN... WILL
BRING IFR/LIFR CONDITIONS AND PERIODS OF MOSTLY LIGHT RAIN THROUGH
DAYBREAK. WE SHOULD SEE A BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN
THROUGH MUCH OF THE MORNING HOURS... MOST LIKELY FROM 11Z TO 16Z...
BUT CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME. THEN STARTING SOON AFTER 16Z... A LINE OF SHOWERS AND
THUNDERSTORMS IS EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC
THROUGH THE AFTERNOON HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
22Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH THIS EVENING. WINDS WILL SHIFT TO BE FROM THE NW WITH THE
COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT INT/GSO AND BETWEEN 04Z
AND 06Z AT RDU.
LOOKING BEYOND 06Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD/PWB
SHORT TERM...
LONG TERM...BADGETT
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
145 AM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT EXTENDING FROM THE GREAT LAKES INTO TEXAS WILL MOVE
INTO CAROLINAS EARLY SUNDAY MORNING. UNTIL THEN...RELATIVELY WARM
AND HUMID AIR WILL STREAM NORTHWARD...ACCOMPANIED BY PERIODS OF
SHOWERS AND THUNDERSTORMS. HIGH PRESSURE WILL FOLLOW THE COLD
FRONT...BRINGING COOLER TEMPERATURES SUNDAY AND MONDAY. THE CENTER
OF THE HIGH WILL MOVE OVERHEAD MONDAY NIGHT INTO TUESDAY.
TEMPERATURES SHOULD CLIMB WELL ABOVE NORMAL FOR MUCH OF NEXT WEEK. A
COLD FRONT MAY REACH THE AREA NEXT FRIDAY...BRINGING A RISK FOR
SHOWERS.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
AS OF 1115 PM FRIDAY...UPDATE CONTINUES TO BE CONCERNED WITH
MASSAGING THE OVERNIGHT HOURLY POPS. LATEST MOSAIC 88D RADAR
TRENDS WILL BE MESHED WITH THE LATEST SREF MODEL PROBABILITY FOR
OVERNIGHT MEASURABLE PCPN. THIS EVOLVED INTO MODIFYING THE HRLY
POPS UP TO SEVERAL HRS AFTER DAYBREAK SAT. A COUPLE FAINT MID
LEVEL VORTS OR S/W TROFS ALOFT TO PUSH ACROSS THE FA OVERNIGHT
LENDING TO MODEST UVVS ACROSS THE FA ESPECIALLY DURING THE
PRE-DAWN SAT HRS. LATEST HRRR MODEL GUIDANCE INDICATES A MORE
WIDESPREAD PCPN SHIELD TO ENCOMPASS THE ILM CWA DURING THIS LATE
EVENING THRU THE PRE-DAWN SAT HRS. HAVE ALSO INCREASED OVERNITE
QPF BASED ON CURRENT OBSERVED ACTIVITY AND LATEST VARIOUS MODEL
QPF OUTPUT. OVERNIGHT TEMPS MAINLY WILL HOLD STEADY OR EVEN
SLIGHTLY INCREASE AS THE FA BECOMES BETTER ENTRENCHED IN THE WARM
SECTOR AHEAD OF THE MAIN UPPER S/W TROF AND ASSOCIATED SFC LOW.
PREVIOUS DISCUSSION.....................................
AS OF 300 PM FRIDAY...A LARGE MCS ALONG THE EASTERN GULF COAST
DOMINATES THE WEATHER PATTERN ACROSS THE SOUTHEASTERN U.S. THE
CONVECTIVE ELEMENTS OF THIS FEATURE ARE LARGELY LIMITED TO
SOUTHERN GEORGIA AND POINTS SOUTH...WITH AN EXPANSIVE BUT
DETERIORATING AREA OF LIGHT RAIN EXTENDING INTO NORTH GEORGIA AND
WESTERN SOUTH CAROLINA. THIS ACTIVITY SHOULD MOVE EASTWARD...
AFFECTING THE SC PEE DEE REGION EARLY THIS EVENING. OTHER
GENERALLY LIGHT SHOWERS DEVELOPING IN A WEAKLY UNSTABLE AIRMASS
ACROSS THE EASTERN CAROLINAS MAY CONTINUE INTO THE EVENING HOURS
AS WELL AS SMALL ELEVATED INSTABILITY IS MAINTAINED BY A SOUTHERLY
FLOW ACROSS THE GULF STREAM OFF THE GEORGIA AND SOUTH CAROLINA
COAST.
THE UPPER LEVEL DISTURBANCE THAT HELPED KICK OFF THE GULF COAST MCS
WILL TURN NORTHEASTWARD TONIGHT...APPROACHING THE EASTERN CAROLINAS
LATE. WHILE A RENEWED BLOWUP OF CONVECTION IS NOT ANTICIPATED DUE TO
MEAGER INSTABILITY...A DIFLUENT UPPER LEVEL PATTERN AND AN
INCREASING NEGATIVE TILT TO THE TROUGH SHOULD ENHANCE RAIN/SHOWER
POTENTIAL OVERNIGHT ALL THE WAY DOWN TO THE COAST. WHILE I CAN`T
BRING MYSELF TO PUT 100 POPS IN THE FORECAST...80-90 PERCENT SEEMS
APPROPRIATE. PRECIPITABLE WATER VALUES SHOULD GROW TO 1.5 INCHES
AFTER MIDNIGHT.
IN TERMS OF MODEL SOLUTIONS...IT IS INTERESTING TO SEE HOW THE
MODELS HAVE HANDLED (OR MISHANDLED) TWO ASPECTS OF THE WEATHER
TODAY. ONE IS THE RELATIVELY LIGHT WINDS OVER THE COASTAL WATERS...
PARTICULARLY WHEN CONTRASTED TO THE RATHER BREEZY CONDITIONS
EXPERIENCED INLAND TODAY. MOST SYNOPTIC GUIDANCE (PARTICULARLY THE
GFS) HAS BEEN TOO STRONG WITH MARINE WIND SPEEDS ALL DAY. ALSO OF
NOTE IS THE PERSISTENT AREA OF LIGHT SHOWERS THAT MOVED INTO
GEORGETOWN THIS MORNING AND NOW COVERS BRUNSWICK COUNTY ACROSS
WHITEVILLE INTO LUMBERTON AND ELIZABETHTOWN. THIS ACTIVITY HAS BEEN
WELL-FORECAST BY THE HRRR AND NAM BUT NOT THE GFS. PREFERRED MODELS
TONIGHT INCLUDE THE HRRR IN THE VERY NEAR-TERM...THEN THE 12Z NAM
AND 12Z CANADIAN OVERNIGHT.
WITH SOUTHERLY WINDS AND CLOUDS CONTINUING OVERNIGHT LOWS SHOULD
ONLY FALL TO 59-60 INLAND WITH 57-58 NEAR THE BEACHES DUE TO WINDS
BLOWING IN OFF THE COLDER NEARSHORE WATERS. THE NAM MOS GUIDANCE IS
MUCH CLOSER TO MY IDEAS THAN THE GFS MOS.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...THE MAIN CHALLENGE CONTINUES TO CENTER
AROUND THE COMPLEX STORM SYSTEM MOVING ACROSS THE SOUTHEAST.
TIMING AND INTENSITY OF RAINFALL AND ASSOCIATED THUNDERSTORMS
REMAIN THE MAIN ISSUES. I HAVE LEANED HEAVILY TOWARD THE GFS FOR
THE LATEST UPDATES TO THE SHORT TERM.
INITIALLY WE COULD HAVE A LARGE SWATH OF RAIN COMING OFF THE
ATLANTIC. AFTER THIS...THERE SHOULD BE A LULL IF YOU WILL WITH SOME
NVA IN THE WAKE OF THIS INITIAL FEATURE. THE MAIN SHORTWAVE FINALLY
GETS ORGANIZED AND MOVES OFF TO THE EAST/NORTHEAST SATURDAY
AFTERNOON WITH YET ANOTHER DEEP MOISTURE FEED FROM THE GULF OF
MEXICO WITH THE ASSOCIATED COLD FRONT. I HAVE INCREASED POPS FOR
LATE AFTERNOON ACROSS WESTERN AREAS AND THE EVENING HOURS FOR
COASTAL SITES. SEVERE PARAMETERS REMAIN MARGINAL AND CONTINUE TO
HINGE ON THE AMOUNT OF INSTABILITY THE IS ABLE TO DEVELOP.
LARGE DIFFERENCES IN TEMPERATURE GUIDANCE WITH THE NAM/MET NUMBERS
QUITE A BIT LOWER FOR DAYTIME HIGHS SATURDAY. I WOULD EXPECT ANY
BREAKS AND THERE SHOULD BE AT LEAST A FEW WILL ALLOW HIGHS TO JUMP
MORE TOWARD THE GFS/MAV NUMBERS. GUIDANCE TRENDS CLOSER SATURDAY
NIGHT AND SUNDAY.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
AS OF 300 PM FRIDAY...THE LONG TERM APPEARS TO OFFER RAIN-FREE
WEATHER. AS FAR AS TEMPERATURES GO DAYTIME HIGHS WILL AVERAGE
ABOUT A CATEGORY ABOVE CLIMO WHILST NIGHTTIME LOWS SHOULD BE EVEN
MILDER. HIGH PRESSURE SLIDES INTO FLORIDA ON MONDAY KEEPING LOCAL
WINDS RATHER LIGHT. MEANWHILE UPPER RIDGING BUILDS IN FROM THE
WEST. TUESDAY THROUGH WEDNESDAY WILL SHIFT THE HIGH SLIGHTLY
EASTWARD WHILE THE UPPER LEVEL WAVE FLATTENS. END RESULT WILL BE A
SLIGHT BOLSTERING OF THE WARM ADVECTION INTO THE REGION. UPPER
LEVEL AMPLITUDE WILL THEN INCREASE AGAIN THURSDAY INTO FRIDAY AS A
STORM SYSTEM MOVES OUT OF THE ROCKIES AND DEVELOPS INTO THE PLAINS
THURSDAY...MOVING INTO OHIO VALLEY COME FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 06Z...EXPECT MVFR/IFR THROUGH THE OVERNIGHT HOURS...WITH BRIEF
INTERMITTENT PERIODS OF VFR POSSIBLE...AS VARYING LOW CIGS AND RAIN
AND AREAS OF HEAVIER SHOWERS MOVE THROUGH THE AREA. MIX OF MVFR/IFR
CONTINUES ON SATURDAY AS LOW TO MID CLOUDS...SHOWERS...AND ISOLATED
TO SCATTERED THUNDERSTORMS MOVE THROUGH...GRADUALLY IMPROVING TO VFR
TOWARDS THE END OF THE PERIOD.
LATEST RADAR IMAGERY CONTINUES TO HIGHLIGHT WIDESPREAD RAIN WITH
SCATTERED HEAVIER SHOWERS. CONFIDENCE IS HIGH THROUGH THE OVERNIGHT
HOURS REGARDING MVFR AND IFR CONDITIONS...BUT HAVE KEPT PREVAILING
MVFR WITH PERIODS OF IFR AS VARYING LOWERED CIGS MOVE ACROSS THE
AREA. ALSO EXPECT REDUCED VISIBILITIES DUE TO AREAS OF FOG AND
SHOWERS. AFTER DAYBREAK...EXPECT MVFR WITH IFR POSSIBLE THROUGH THE
MORNING HOURS...ALONG WITH WIDESPREAD RAINFALL AND ISOLATED
THUNDERSTORMS. STRONGER STORMS ARE POSSIBLE IN THE AFTERNOON/EVENING
HOURS. SOUTHERLY WINDS WILL PREVAIL WITH SUSTAINED WINDS AOB 12 KTS
AND PERIODIC GUSTS POSSIBLE THROUGHOUT THE DAY...ESPECIALLY IN
STRONGER STORMS...AROUND 20 KTS OR SLIGHTLY HIGHER. TOWARDS THE END
OF THE PERIOD...COULD SEE SOME IMPROVEMENT TO VFR WITH CONVECTION
GRADUALLY TAPERING OFF.
EXTENDED OUTLOOK...BECOMING VFR OVERNIGHT SATURDAY INTO SUNDAY.
SLIGHT CHANCE FOR SHOWERS AND MVFR CEILINGS OVER THE NORTHERN
PORTION OF THE CWA. OTHERWISE VFR THROUGH WEDNESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1115 PM FRIDAY...THIS UPDATE REMAINS MORE CONCERNED WITH
THE INCREASED POTENTIAL FOR SEA FOG...AND THE ASSOCIATED POTENTIAL
VISIBILITY DROPPING BELOW 1 NM. THIS A RESULT OF 60+ SFC DEW
POINTS PUSHING ACROSS SHELF WATER SSTS IN THE LOW TO MID 50S.
HAVE CONTINUED THE OVERALL ONSHORE WIND REGIME FROM THE PREVIOUS
FORECAST...WITH THE PROGGED SFC PRESSURE PATTERN AND GRADIENT
KEEPING WINDS FROM THE SSE-S AT 10 TO 15 KT WIND SPEEDS. WAA
WINDS TOUGH TO MIX DOWN TO THE OCEAN SURFACE EXHIBITING 50 DEGREE
SSTS. HOWEVER...THE SFC PG IS EXPECTED TO FURTHER TIGHTEN BUT NOT
UNTIL THE MAIN SFC LOW AND COLD FRONT PUSH CLOSER TO THE FA DURING
DAYLIGHT SATURDAY. SIGNIFICANT SEAS HAVE STABILIZED LATE THIS
EVENING BUT SHOULD BEGIN TO TREND SLIGHTLY HIGHER BY OR JUST AFTER
DAYBREAK SATURDAY. BUILDING WIND DRIVEN WAVES JUST OFFSHORE...
HAVING BEEN CREATED BY THE HIER SE-S WINDS JUST OFFSHORE OVER THE
MUCH WARMER SSTS...WILL PUSH INTO THE LOCAL WATERS AND MESH WITH
THE LOCAL WAVES. SCA REMAINS BONAFIDE FOR THE REMAINDER OF
TONIGHT...WITH SIGNIFICANT SEAS THE PRIMARY REASON.
PREVIOUS DISCUSSION.....................................
AS OF 300 PM FRIDAY...SOUTH WINDS SHOULD CONTINUE OVERNIGHT AS THE
CAROLINAS ARE IN BETWEEN HIGH PRESSURE WELL OFFSHORE AND AN
APPROACHING COLD FRONT OVER THE MISSISSIPPI VALLEY. THE GFS MODEL
HAS BEEN TOO STRONG WITH WIND SPEEDS ALL DAY...BUT A COMBINATION OF
THE 12Z NAM AND CANADIAN MODELS SEEMS LIKE A GOOD FIT. SOUTH WINDS
10-15 KNOTS WILL RAISE A SHORT-PERIOD WIND WAVE...BUT STRONGER WINDS
OFFSHORE WILL CREATE LARGER WAVES THAT WILL PUSH WESTWARD INTO THE
COASTAL WATERS AS WELL. THE COMBINATION SHOULD CREATE 4-6 FOOT SEAS
WITH A 6 SECOND DOMINANT PERIOD...AND A SMALL CRAFT ADVISORY WILL
REMAIN IN EFFECT FOR THIS. WAVES OF SHOWERS ARE EXPECTED ACROSS THE
WATERS...WITH HEAVIER ACTIVITY POSSIBLE OVERNIGHT. PM FRIDAY...
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM FRIDAY...FAIRLY BRISK CONDITIONS WILL PREVAIL OVER THE
WATERS THROUGH THE PERIOD. FOR SATURDAY...A SOUTHERLY FLOW OF
15-20 KNOTS WILL BE IN PLACE AS LOW PRESSURE AND A COLD FRONT EDGE
CLOSER FROM THE WEST. THIS FRONT CROSSES THE WATERS BETWEEN 0600
AND 1200 UTC SUNDAY. WINDS WILL TURN FROM THE WEST AND INCREASE TO
20-25 KNOTS. WITH COLD AIR ADVECTION DEVELOPING SUNDAY...THE WINDS
WILL REMAIN ELEVATED BUT HOPEFULLY NOT THE LEVEL WE SAW EARLIER IN
THE WEEK TO GALE CRITERIA. BY MONDAY MORNING THERE IS A SLOW
DECREASE TO AROUND 15 KNOTS.
SIGNIFICANT SEAS WILL HOVER AROUND SMALL CRAFT CRITERIA AND I WILL
GO AHEAD AND EXTEND THE ADVISORY TO COVER SATURDAY AND SATURDAY
NIGHT. THE CHANGE IN FETCH SHOULD EVENTUALLY ALLOW THE ADVISORY TO
EXPIRE SUNDAY.
LONG TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 300 PM FRIDAY...MONDAY STARTS WITH A MODERATE NW FLOW A RESULT
OF BOTH DEEPENING STORM MOVING UP THE MIDATLANTIC COAST AND HIGH
PRESSURE BUILDING IN FROM THE WEST. AS BOTH PROGRESS EASTWARD THE
LOCAL GRADIENT SHOULD REALLY EASE AS THE DAY WEARS ON AND BY MONDAY
NIGHT THERE MAY BE A LIGHT ENOUGH GRADIENT FOR A TRUE LIGHT AND
VARIABLE WIND. TUESDAY INTO WEDNESDAY THE HIGH TAKES A MORE OFFSHORE
POSITION GENERATING A LIGHT S TO SW FLOW LOCALLY. SEAS BUILD FROM
THEIR MINIMAL MONDAY NIGHT VALUES TO ABOUT 2 TO 3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EDT SUNDAY FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...DCH/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...SGL/RJD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
335 AM CDT SAT MAR 29 2014
.DISCUSSION...
SFC LOW WL MOVE FROM EASTERN MS ACRS E TN TDY. INVERTED TROF OVER
THE MID STATE WILL ALSO SHIFT EAST AND ALLOW COLDER AIR TO FILTER
IN. THE MAIN CHALLENGES IN THE NEAR TERM INVOLVE PCPN CVRG AND HOW
MUCH TEMPS WL RECOVER AS PCPN PULLS OUT LATER. FOR NOW LEANED PCPN
FCST TWRD THE LATEST HRRR WHICH HAS HAD A PRETTY GOOD HANDLE ON
THINGS THUS FAR. XPCT TO SEE RAIN INCRS IN CVRG QUICKLY OVER THE
NEXT FEW HOURS AND GRADUALLY EVOLVE INTO A BIT OF A COMMA HEAD
BEFORE PULLING OUT LATER THIS AFTN. RAIN WILL LIKELY NOT REACH THE
PLATEAU UNTIL MID MORNING AND WILL BE ENDING ALONG THE TN RIVER BY
MIDDAY. AS FAR AS TEMPS GO...HIGHS ARND NASHVILLE AND POINTS EAST
WILL LIKELY BE RIGHT ARND 8 AM JUST AHEAD OF THE BNDRY WITH A
PRETTY SHARP DROP THRU THE MORNING. WILL SEE SOME TEMPERATURE RECOVERY
AGAIN IN THE AFTN AS RAIN CVRG DECREASES.
SOME RAIN MAY LINGER IN THE FAR EAST ERLY THIS EVE OTHW XPCT A
QUICK CLEARING AS SYS PULLS AWAY. MAV TEMPERATURES LOOK RSNBL
GIVEN THE CLEARING SKIES AND A PRETTY COOL START. WX THEN LOOKS
NICE AND SPRINGLIKE INTO MID-WEEK AS RIDGING DOMINATES. STILL WL
HV TO WATCH WEAK FRONT ON TUE FOR SOME CLDS AND A LITTLE LIGHT
PCPN BUT DOESN`T LOOK LIKE MUCH RIGHT NOW. HPC TEMPS WERE FOLLOWED
PRETTY CLOSE.
THE FAR EXTENDED STILL LOOKS ACTIVE BUT AS IS TYPICAL THE ALL
IMPORTANT DETAILS ARE MURKY. GENERAL PATTERN SUGGESTS WARM AND
HUMID CONDITIONS WITH ROUNDS OF SHOWERS AND STORMS AS SFC LOWS
MOVE TO OUR WEST.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 57 34 61 38 / 90 0 0 0
CLARKSVILLE 54 31 59 38 / 90 0 0 05
CROSSVILLE 56 35 54 33 / 90 20 0 05
COLUMBIA 59 35 63 38 / 90 0 0 05
LAWRENCEBURG 60 35 63 36 / 90 0 0 05
WAVERLY 57 33 61 39 / 90 0 0 05
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
JOHNSTONE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
328 AM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT MAR 29 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY DEEP TROUGH OFF THE PACIFIC NORTHWEST...RIDGING
PUSHING EASTWARD ACROSS THE ROCKIES...AND TROUGHING FROM MINNESOTA
SOUTH INTO ARKANSAS. THE NORTHERN PORTION OF THIS TROUGH HAS BEEN
UNEVENTFUL FOR THE FORECAST AREA...BRINGING ONLY SOME MID/HIGH
CLOUDS. DRY AIR SITUATED BETWEEN 900-700MB ON THE 00Z GRB...MPX AND
DVN SOUNDINGS KEPT ANY POTENTIAL PRECIPITATION FROM THESE CLOUDS
FROM REACHING THE GROUND. HOWEVER...AT AND BELOW 900MB...
OBSERVATIONS ARE SHOWING SOME LOW STRATUS DEVELOPING ACROSS
SOUTHERN WI. THIS STRATUS IS A RESULT OF EASTERLY FLOW OF MOISTURE
FROM LAKE MICHIGAN COMBINING WITH NOCTURNAL COOLING AND AN INVERTED
SURFACE TROUGH IN THE AREA. TO THE NORTHWEST...CLEARING ASSOCIATED
WITH SURFACE HIGH PRESSURE WAS PRESENT ACROSS MUCH OF MINNESOTA.
AIRMASS OVER THE UPPER MIDWEST STILL RELATIVELY COOL WITH 00Z RAOBS
SHOWING 925MB TEMPS OF -3 TO -5C FROM THE FORECAST AREA TO BIS.
HOWEVER...LBF AND UNR ON THE BACK SIDE OF THE SURFACE HIGH WERE MUCH
WARMER AT +11 AND +15C RESPECTIVELY.
A PROGRESSIVE UPPER FLOW PATTERN IS PROGGED THROUGH THE SHORT TERM
PERIOD AS A VIGOROUS SHORTWAVE AT THE BOTTOM OF THE EAST PACIFIC
TROUGH...NEAR 35 NORTH / 140 WEST...MOVES INTO CALIFORNIA. FOR
COMPARISON...THE FORECAST AREA GOES FROM UNDER A SHORTWAVE TROUGH
AXIS AT 12Z SATURDAY TO A RIDGE AXIS AT 12Z SUNDAY. 3 MAIN
IMPACTS FROM THIS SWITCH:
1. SUBSIDENCE AND DRYING ASSOCIATED WITH BUILDING UPPER RIDGING WILL
HELP CLEAR OUT ANY LOW CLOUDS BY 18Z...LEADING TO A SUNNY AFTERNOON
WITH JUST SOME SCATTERED CIRRUS TONIGHT.
2. AFTER MOSTLY A LIGHT WIND FLOW TODAY AS SURFACE RIDGE MOVES
THROUGH...SOUTHERLY WINDS INCREASE GREATLY TONIGHT...ESPECIALLY FROM
925-850MB. BY 12Z SUNDAY...THEY ARE RUNNING BETWEEN 40-50 KT.
3. 925-850MB TEMPS FOLLOW THE INCREASE IN WINDS. FOR EXAMPLE...
925MB TEMPS AFTER STARTING OFF BETWEEN -2 TO -5C AT 12Z THIS MORNING
CLIMB TO 0 TO +3C AT 00Z SUNDAY...THEN TO 2 TO +5C AT 12Z SUNDAY.
SUNSHINE SHOULD EASILY BOOST HIGHS INTO THE 40S TODAY AT MOST
LOCATIONS...WITH A FEW VALLEY AREAS APPROACHING 50. TEMPERATURES
SHOULD BOTTOM OUT THIS EVENING BEFORE THE LOW LEVEL JET INCREASES
AND CAUSES THEM TO STABILIZE. READINGS SHOULD RISE LATE TONIGHT AS
THE WARMER AIR FLOWS IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT MAR 29 2014
MANY WEATHER CONCERNS TO HIGHLIGHT DURING THE LONG TERM PERIOD AS
THE FORECAST AREA LOOKS TO RESIDE MUCH OF THE TIME IN SOUTHWEST FLOW
ALOFT.
1. ABOVE NORMAL TEMPERATURES SUNDAY THROUGH MONDAY. THE VIGOROUS
SHORTWAVE COMING INTO CALIFORNIA TONIGHT REMAINS ON TRACK TO LIFT
INTO EASTERN SOUTH DAKOTA OR SOUTHWEST MN BY 00Z TUESDAY...PUSHING
WARM...DOWNSLOPED AIR OFF THE ROCKIES INTO THE FORECAST AREA AHEAD
OF IT. 925MB TEMPS ARE PROGGED TO CLIMB TO 9-13C BY 00Z
MONDAY...COOLEST OVER TAYLOR/CLARK COUNTIES. THESE READINGS COMBINED
WITH SUN THROUGH SCT-BKN CIRRUS AND BREEZY SOUTHERLY WINDS SHOULD
PUSH TEMPERATURES INTO THE 60S ALONG/SOUTHWEST OF I-94...WITH 50S TO
THE NORTH. A SOUTHERLY BREEZE PERSISTS INTO SUNDAY NIGHT AND
MONDAY. THIS WIND SHOULD ONLY ALLOW TEMPERATURES TO FALL INTO THE
40S SUNDAY NIGHT...WITH MAYBE SOME 30S IN THE TYPICAL COLD SPOTS.
THEN ON MONDAY...WITH MODEL CONSENSUS KEEPING THE FORECAST AREA IN
THE WARM SECTOR HIGHLIGHTED BY 925MB TEMPS OF 9-13C...SHOULD SEE
ANOTHER DAY OF HIGHS MOSTLY IN THE MID 50S TO MID 60S. THIS OCCURS
DESPITE SOME WARM ADVECTION PRECIPITATION MOVING THROUGH.
2. PRECIPITATION AND THUNDERSTORM POTENTIAL MONDAY INTO MONDAY
NIGHT. THE SIGNAL STILL EXISTS FOR A WARM CONVEYOR BELT OF
SHOWERS TO MOVE ACROSS THE FORECAST AREA...ESPECIALLY DURING THE
LATE MORNING AND AFTERNOON HOURS...AS ISENTROPIC LIFT ON 300K
SURFACES AND ABOVE INCREASES. THE BEST MOISTURE EXISTS NORTH OF I-
90...THUS HIGHEST CHANCES OF 50-70 ARE SITUATED THERE. THE POTENTIAL
STILL EXISTS FOR A BAND OF SHOWERS AND SOME EMBEDDED THUNDERSTORMS
TO FORM ALONG THE COLD FRONT CROSSING LATE IN THE AFTERNOON AND
EVENING. HOWEVER...A COUPLE OF CONCERNS FOR THIS BAND INCLUDE MODELS
MAY BE OVERDOING THE MOISTURE RETURN AND NOT MIXING DEWPOINTS OUT
ENOUGH...AND THE TIME OF DAY IS BEING PUSHED TO OUTSIDE OF PEAK
HEATING. SHOULD STORMS FIRE...THERE REMAINS AMPLE SHEAR TO ALLOW FOR
SEVERE WEATHER. LASTLY...CONFIDENCE HAS INCREASED THAT THE
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE ASSOCIATED SURFACE LOW
WILL TRACK NORTHWEST OF THE FORECAST AREA ON MONDAY...AND CLIP THE
NORTHWEST HALF OF THE FORECAST AREA MONDAY NIGHT BEFORE LIFTING OFF
TO THE NORTHEAST. COLDER AIR RUSHING IN SHOULD ALLOW FOR A
CHANGEOVER TO SNOW...WITH A BRIEF PERIOD OF SLEET POSSIBLE DURING
THIS CHANGEOVER AS COLD AIR UNDERCUTS WARMER AIR ALOFT. LITTLE SNOW
ACCUMULATION IS EXPECTED...THOUGH. THERE IS ALSO POTENTIAL TO LOSE
ICE IN THE CLOUDS DUE TO A DRY SLOT...BUT THE LOSS OF ICE OCCURS
EITHER WHERE TEMPERATURES ARE ABOVE FREEZING TO RESULT IN RAIN OR
WHERE NO PRECIPITATION WILL OCCUR.
3. WINDS MONDAY AFTERNOON AND NIGHT. ECMWF/GFS PROG 925MB WINDS OF
30-40 KT SOUTH OF I-90 DURING THE AFTERNOON. IF MORE SUN OCCURS THAN
EXPECTED...THESE COULD EASILY MIX DOWN TO THE SURFACE AND SEE
BOTH SUSTAINED WINDS AND GUSTS APPROACH ADVISORY. INCREASED WINDS
AND GUSTS AS A RESULT. ALSO...AS THE LOW PASSES TO OUR
NORTHEAST...A TIGHT PRESSURE GRADIENT WITH 925MB WINDS OF 30-40 KT
FROM THE SOUTHWEST TO WEST USHERS IN COLD AIR. WITH SOME ISALLOBARIC
AID...COULD SEE GUSTS HERE TOO APPROACH ADVISORY FOR A BRIEF TIME.
4. WINTRY MIX POTENTIAL LATE TUESDAY NIGHT THROUGH FRIDAY. MODELS
ARE AT ODDS ON HOW TO HANDLE THE EJECTION OF TROUGHING OUT OF THE
SOUTHWESTERN U.S. ON TUESDAY TOWARDS THE REGION LATER IN THE WEEK.
THERE WILL NO DOUBT BE A COLDER DOME OF HIGH PRESSURE INFLUENCING
THE AREA...LIKELY SITUATED FROM NORTHERN MN INTO UPPER MI. IN
ADDITION...AS THE TROUGH EJECTS...ISENTROPIC LIFT OF WARMER...GULF
OF MEXICO MOISTURE WILL SPREAD PRECIPITATION NORTH TOWARDS THE
FORECAST AREA. THIS SETS UP CONCERN FOR THE WINTRY MIX. FOR NOW HAVE
FOLLOWED A MODEL CONSENSUS WITH PRECIPITATION CHANCES...WHICH SEEMS
MOST LIKELY TO OCCUR WEDNESDAY SOUTH OF I-90. ALSO KEPT TYPES AS
RAIN/SNOW BASED ON HOURLY TEMPERATURES...BUT THERE IS DEFINITELY
POTENTIAL FOR SLEET AND FREEZING RAIN/DRIZZLE AT TIMES. 29.00Z ECMWF
EVEN PRODUCES AT LEAST ADVISORY WORTHY SNOWFALL OVER THE NORTHWEST
HALF OF THE AREA THURSDAY AND THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1137 PM CDT FRI MAR 28 2014
MID-LEVEL TROUGH CONTINUES TO MOVE EAST ACROSS THE AREA WITH THE
BACK EDGE OF VFR/MID CLOUDS APPROACHING SOUTHEAST MN. STILL
THINKING MID CLOUD WILL SCATTER OUT AT KRST BY 06Z AND AT KLSE BY
08Z. FOCUS THEN TURNS TO MVFR STRATUS ACROSS SOUTHERN WI THAT WILL
BE ADVECTING WESTWARD TOWARD THE KLSE TAF SITE AROUND THE SAME
TIME THE MID CLOUDS SCATTERS. THIS IS IN RESPONSE TO AN EASTERLY
FLOW OFF LAKE MICHIGAN AND AN INVERTED SURFACE TROUGH SETTING UP
JUST EAST OF THE MISSISSIPPI RIVER. RAP/NAM MODELS CONTINUE TO
STOP THIS STRATUS JUST SHY OF THE KLSE TAF SITE...KEEP IT ACROSS
SOUTHEAST LA CROSSE COUNTY/WESTERN MONROE COUNTY. WILL CONTINUE TO
HONOR THIS SIGNAL AND CARRY A SCT025 SKY CONDITION AT KLSE AFTER
08Z. WILL CONTINUE TO MONITOR THIS MVFR CLOUD CLOSELY. EXPECTING
STRATUS TO ERODE TO THE SOUTHEAST SATURDAY MORNING WITH HIGHS
PRESSURE RIDGE BUILDING IN. SKC/VFR CONDITIONS THEN EXPECTED THROUGH
THE REST OF THE DAY WITH LIGHT/VARIABLE WINDS...TURNING LIGHT
SOUTHEAST THROUGH THE AFTERNOON HOURS. PLAN ON SOME SCATTERED
CIRRUS TO MOVE INTO THE AREA SATURDAY EVENING AHEAD OF A WARM
FRONT MOVING THROUGH THE NORTHERN PLAINS/NORTHERN MN WITH WINDS
PICKING UP OUT OF THE SOUTHEAST THROUGH THE NIGHT.
&&
.HYDROLOGY...
ISSUED AT 328 AM CDT SAT MAR 29 2014
MAIN FOCUS FOR RIVER ISSUES FROM THE RECENT RAIN IS ON THE KICKAPOO
RIVER. SOME LOCATIONS ALONG IT ARE EITHER IN OR EXPECTED TO REACH
FLOOD STAGE AS RUNOFF CONTINUES TO WORK ITS WAY DOWNSTREAM.
FROM SUNDAY INTO MONDAY NIGHT...THE RAPID WARM UP WILL CAUSE THE
SNOW PACK NORTH OF INTERSTATE 94 TO MELT RAPIDLY. IN
ADDITION WITH FROZEN GROUND...ANY RAINFALL ON MONDAY AND
MONDAY NIGHT WILL QUICKLY RUNOFF INTO AREA RIVERS AND STREAMS. THIS
WILL RESULT IN RISES ALONG THE BLACK...BUFFALO...AND TREMPEALEAU
RIVERS IN WESTERN WISCONSIN. SOME FLOODING IS ALSO A POSSIBILITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
346 AM PDT Sat Mar 29 2014
.Synopsis...
Rain and mountain snow over Interior Northern California today
with a threat of afternoon thunderstorms...decreasing Sunday. A
colder and wetter storm impacts the area Monday and Tuesday with
another system possible towards the end of the week.
&&
.Discussion...
Pacific front will work its way through Interior NorCal this
morning with steady precip turning showery behind the baroclinic
zone. Periods of moderate to heavy snow and gusty wind expected
in the Western Plumas and Northern Sierra Nevada today as the
storm tracks through. Snow levels this morning running around 6000
to 6500 feet but will lower to around 5000 to 5500 feet later
today behind the front. Both the HRRR and local WRF showing an
area of 500+ J/kg CAPE developing over the Northern Sac Valley
later this morning with increasing instability spreading
southward in the Central Valley and east towards the foothills
this afternoon. Shear profiles do support potential for rotating
updrafts although they are not as favorable as with the system
that moved through Wednesday. Highs today expected only in the
lower 60s for the Central Valley with generally 40s to 50s for the
mountains and foothills.
Upper trough and associated cold pool aloft moves through tonight
for continued shower threat then weak ridging Sunday. This will be
short lived as the next colder deeper system approaches NorCal.
Some model differences exist with timing but in general precip looks
to begin over the Coastal and Western Shasta mountains Monday
morning...spreading south and east over the entire CWA by the
afternoon. Snow levels could drop to near the upper foothills
with this system as it moves through Mon/Tue. Also, potential for
more thunderstorms, with small hail, looks to be a good bet on
Tue. Well below normal temps early next week with highs only in
the 50s for the Central Valley with 30s to 40s in the
mountains/foothills on Tuesday.
.Extended Discussion (Wednesday through Saturday)
Short-wave ridging forecast to move over NorCal Wednesday behind
departing cold upper low moving into the desert SW. This will
result in decreasing POPS for the region mid-week along with
milder temperatures. Forecast uncertainty increases the second
half of next week as models show little consistency in handling of
the next trough forecast to potentially affect the region later
Thu-Sat, so will continue to mention chance category POPS for now.
&&
.Aviation...
Pacific frontal sys moves swd thru NorCal today. For the valley...
VFR conds expected next 24 hrs exc areas of MVFR cigs and sly sfc
wind gusts 20-30 kts ahead of frontal passage thru abt 20Z. Sct
-shra with isold TSRA behind front for this aftn and evening. Over
nrn Siernev...wdsprd IFR conds RA/SN cont thru 12Z Sun. Sn lvls
055-065 this morning...lowering to 040-045 aft 00Z Sun.
&&
.STO Watches/Warnings/Advisories...
Winter Storm Warning until 5 am pdt Sunday above 5500 feet in the
West Slope Northern Sierra Nevada...Western Plumas county/Lassen
Park.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
923 AM EDT SAT MAR 29 2014
.UPDATE...
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST BASED ON CURRENT
TRENDS AND CURRENT OBSERVATIONS. HEAVY CLOUD FROM THUNDERSTORM
DEBRIS FIELD CURRENTLY COVERS MOST OF SOUTH FLORIDA THIS MORNING.
THE THUNDERSTORM COMPIEX IS LOCATED IN THE SOUTHEAST GULF OF
MEXICO ABOUT 150 MILES WEST OF NAPLES AND WAS MOVING VERY LITTLE.
THE MAIN TROUGH IS CURRENTLY DEEPENING OVER THE SOUTHERN GULF
STATES WHICH IS GENERATING A LINE OF THUNDERSTORMS OVER THE
NORTHEAST GULF OF MEXICO. MOST OF THIS ACTIVITY THROUGH THIS
AFTERNOON WILL BE AFFECTING CENTRAL FLORIDA. THE 12Z MFL SOUNDING
DOES SHOW SOME LOW LEVEL INSTABILITY BUT MID LEVEL LAPSE RATES
REMAIN WEAK. THE KEY ASPECT FOR SOUTH FLORIDA WEATHER THROUGH THE
REMAINDER OF THE DAY IS HOW MUCH CLEARING AND WARMING WILL TAKE
PLACE THIS AFTERNOON. THERE ARE NO SIGNS OF CLOUDS THINNING AT
THIS TIME AND THEREFORE LOWERED THE MAXIMUM TEMPERATURES ACROSS
THE INTERIOR. IT APPEARS AT THIS TIME THAT THE MAIN THREAT WILL BE
THIS EVENING AND OVERNIGHT AS THE MAIN BAND FROM THE NORTHEAST
GULF ARRIVES IN SOUTH FLORIDA AND THIS IS WHAT THE HRRR IS SHOWING
WITH NOT MUCH HAPPENING THROUGH AT LEAST 16Z AND SO FOLLOWED THIS
GUIDANCE.
KOB
&&
.PREV DISCUSSION... /ISSUED 653 AM EDT SAT MAR 29 2014/
AVIATION...
A COLD FRONT OVER THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE SOUTH TOWARDS SOUTH FLORIDA TODAY. THIS WILL ALLOW FOR THE
WINDS OVER SOUTH FLORIDA TAF SITES TO SWING FROM A SOUTHEAST
DIRECTION THIS MORNING TO A SOUTHWEST DIRECTION BY LATE THIS
AFTERNOON INTO THIS EVENING. THE WIND SPEEDS WILL BE AROUND 10
KNOTS THIS MORNING INCREASING TO 10 TO 15 KNOTS BY THIS
AFTERNOON...BEFORE DECREASING AGAIN TO AROUND 10 KNOTS THIS
EVENING.
THERE WILL BE A THREAT OF SHOWERS THIS MORNING OVER THE TAF SITES
BEFORE A THUNDERSTORM THREAT THIS AFTERNOON MAINLY AFTER 18Z.
THE VIS AND CEILINGS OVER SOUTH FLORIDA TAF SITES WILL REMAIN IN
THE VFR CONDITIONS AT THIS TIME DUE TO THE UNKNOWN TIMING OF THE
SHOWERS AND THUNDERSTORMS. BUT WHEN THEY DO DEVELOP AND PUSH
THROUGH THE TAF SITES...THEY COULD FALL INTO THE IFR CONDITIONS.
PREV DISCUSSION... /ISSUED 403 AM EDT SAT MAR 29 2014/
DISCUSSION...
MAIN FOCUS REMAINS OVER THE NEXT 24 TO 30 HOURS WITH SHOWER AND
THUNDERSTORM CHANCES ASSOCIATED WITH THE PASSAGE OF A COLD FRONT.
LATEST MICRON SATELLITE IMAGERY SHOWS A LINE OF THUNDERSTORMS ACROSS
THE NORTHERN GULF OF MEXICO AHEAD OF A COLD FRONT. THESE STORMS ARE
PUSHING TO THE EAST AND WILL AFFECT THE FLORIDA PANHANDLE THROUGH
THE MORNING. AN AREA OF LOW PRESSURE WILL DEEPEN AS IT SLIDES TO
THE NORTHEAST AND INTO THE APPALACHIANS. THIS WILL ALLOW THE COLD
FRONT TO PUSH FURTHER SOUTH AND THROUGH THE AREA BY LATE TONIGHT
AND INTO EARLY SUNDAY MORNING. SHOWERS AND THUNDERSTORMS WILL
BEGIN TO PUSH INTO SOUTH FLORIDA LATER TODAY AS THE FRONT
APPROACHES. BETTER DYNAMICS ARE STILL EXPECTED TO BE WELL NORTH OF
THE AREA AND THE BEST FORCING ALONG THE FRONT LOOKS TO ARRIVE WELL
AFTER DARK. HOWEVER...THE AIRMASS SHOULD STILL BE RATHER BUOYANT
WITH MODEL SOUNDINGS DEPICTING SBCAPE VALUES AROUND 2000 J/KG.
THEREFORE BELIEVE A FEW THUNDERSTORMS COULD PRODUCE GUSTY WINDS
AND BRIEF HEAVY DOWNPOURS WITH THE GREATEST COVERAGE OF SHOWERS
AND THUNDERSTORMS BEING OVERNIGHT.
THE FRONT SHOULD EXIT THE AREA COMPLETELY BY MIDDAY SUNDAY ALLOWING
A MUCH DRIER AIRMASS TO FILTER INTO THE AREA. STRONG PERSISTENT HIGH
PRESSURE WILL THEN DOMINATE THE WEATHER ACROSS THE FLORIDA PENINSULA
THROUGH VIRTUALLY ALL OF NEXT WEEK WITH NEAR NORMAL TEMPERATURES.
AVIATION...
A LOW PRESSURE SYSTEM OVER LOUISIANA WILL MOVE TO THE NORTHEAST
THROUGH THE TAF PERIOD. THIS WILL INITIALLY JUST KEEP WINDS OUT OF
THE SOUTHEAST WITH MID AND UPPER LEVEL CLOUDS. BY MID MORNING, CIGS
WILL LOWER, BUT SHOULD STILL BE GENERALLY MVFR, IF NOT VFR. THERE
WILL ALSO BE RAIN SHOWERS MOVING INTO SOUTH FLORIDA BY LATE MORNING.
IT IS ALSO POSSIBLE THAT A FEW THUNDERSTORMS WILL DEVELOP FROM MID
DAY ON, BUT THERE IS CURRENTLY TOO MUCH UNCERTAINTY TO PLACE THEM IN
THE TAFS AT THIS TIME. WINDS WILL PICKUP JUST AFTER SUNRISE, OUT OF
THE SOUTH-SOUTHEAST BETWEEN 10 AND 15 KTS. THEY WILL TURN MID DAY TO
THE SOUTHWEST AT AROUND 15 KTS. A COLD FRONT WILL THEN MOVE ACROSS
SOUTH FLORIDA SOMETIME IN THE OVERNIGHT HOURS. AHEAD OF THE FRONT,
IN THE EVENING HOURS, THE WINDS WILL BE MORE WEST SOUTHWEST AT 5 TO
10 KTS.
MARINE...
NORTHEASTERLY SWELL WILL CONTINUE TO DIMINISH THROUGH THE DAY AS
WINDS BECOME MORE SOUTHERLY. A COLD FRONT WILL CROSS THROUGH THE
AREA WATERS OVERNIGHT TONIGHT AND INTO SUNDAY MORNING TURNING
WINDS AROUND TO THE NORTH AND INCREASING TO AROUND 15 TO 20 MPH
WITH A BRIEF CORRESPONDING INCREASE IN SEAS ON SUNDAY BEFORE
DIMINISHING BY MONDAY AS WINDS DECREASE SLIGHTLY.
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
605 AM EDT Sat Mar 29 2014
.Near Term [Through Today]...
The 09 UTC regional surface analysis continued to be largely
dominated by mesoscale features. The wake low analyzed in South GA
earlier tonight has weakened, and a new meso high (induced by a cold
pool from the MCS to our west) has developed in the western FL
Panhandle. The strong, well-organized MCS at the beginning of our
shift has weakened and now appears rather sloppy on satellite &
radar imagery. The storms that moved into our western zones have
been mostly elevated, and this will likely continue until later this
morning when (if) there is some heating. The HRRR has been handling
the simulated reflectivity well so far and we have followed it
closely for this forecast update. Most of our local WRFs appears to
be too slow, so we have sped up the timing of the rain from our
earlier forecast. This means that most of the rain will end from
west to east this afternoon. Because of this faster solution, the
severe threat may be diminishing a bit, as the most of the storms
may be east of our forecast area by the time the boundary layer
destabilizes significantly. Still, we can`t rule out an isolated
severe storm given the strong winds and relatively steep lapse rates
aloft. Damaging wind gusts and hail are the main threats, but we
can`t completely rule out an brief tornado.
.Short Term [Tonight Through Monday]...
Deep layer ridging and a very dry airmass will build into the
region in the wake of the exiting upper trough and surface cold
front. Max temps will be near to above seasonal levels while min
temps will be cooler, especially Sunday night with nearly ideal
radiational cooling conditions setting up. Max temps will be in
the lower to mid 70s Sunday and upper 70s to near 80 on Monday.
Lows will be in the in the lower to mid 40s tonight and around 40
Sunday night.
.Long Term [Monday Night Through Saturday]...
Upper level ridging will stay in place over the southeastern
CONUS through Wednesday. Wednesday night, another shortwave trough
over the four corners region will amplify the upper level pattern,
developing a surface low over the southern Plains and an
associated cold front. As this system pushes eastward Thursday and
Friday, chances for showers and thunderstorms increase from west
to east across our forecast area.
&&
.Aviation...
[Through 12Z Sunday] Numerous SHRA and TSRA will be moving east
through the region today, mainly this morning. Gusty winds and poor
brief period of poor visibility are expected at all terminals. The
rain will end from west to east later this morning. Skies will be
clearing later this afternoon as the winds shift and become NW to
N.
&&
.Marine...
Winds and seas will increase from from west to east to advisory
levels from this evening to Sunday morning in the wake of an
exiting strong cold front. Conditions will improve by Sunday
afternoon with light winds and low seas for Monday through the
middle of next week.
&&
.Fire Weather...
Wet conditions are expected today. RH values may fall to locally
critical levels Sunday afternoon. However, at this time we don`t
think that ERC/fuel moisture values and/or wind speeds will be
sufficient for Red Flag warnings.
&&
.Hydrology...
Widespread rainfall amounts of 2 to 4 inches were received over
Southeast Alabama and the Florida Panhandle...with 1 to 2 inches
elsewhere. An additional 0.50 TO 1 inch rainfall amounts are
expected across these areas today as a cold front pushes through.
Many area rivers remain in action stage and could possibly reach
minor flood stage. However, the latest forecast from the RFC keep
everything below flood stage.
For the latest river stages and forecasts, please visit:
water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 80 46 74 38 79 / 80 10 0 0 0
Panama City 75 47 72 47 75 / 80 0 0 0 0
Dothan 76 43 71 41 78 / 80 0 0 0 0
Albany 76 43 72 40 79 / 80 0 0 0 0
Valdosta 77 44 72 40 78 / 80 10 0 0 0
Cross City 79 47 74 40 78 / 70 10 0 0 0
Apalachicola 74 48 70 44 73 / 70 0 0 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...High Rip Current Risk through this evening for Coastal Bay-
Coastal Franklin-Coastal Gulf-South Walton.
GA...None.
AL...None.
GM...Small Craft Advisory from 11 PM this evening to 10 AM EDT
Sunday for Apalachee Bay-Coastal waters from Suwannee River
to Keaton Beach FL out 20 NM.
Small Craft Advisory from 6 PM this evening to 10 AM EDT Sunday
for Coastal waters From Ochlockonee River to Apalachicola
FL out to 20 NM-Coastal waters from Apalachicola to Destin
FL out 20 NM-Waters from Suwannee River to Apalachicola FL
from 20 to 60 NM-Waters from Apalachicola to Destin FL from
20 to 60 NM.
&&
$$
NEAR TERM...FOURNIER
SHORT TERM...BARRY
LONG TERM...MOORE
AVIATION...FOURNIER
MARINE...BARRY
FIRE WEATHER...FOURNIER
HYDROLOGY...BARRY/BOLDEN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1103 AM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA THIS EVENING...THEN DRY HIGH
PRESSURE WILL BUILD INTO THE REGION THROUGH THURSDAY. A COLD FRONT
WILL MOVE THROUGH NEXT FRIDAY OR FRIDAY NIGHT BEFORE HIGH PRESSURE
REBUILDS NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATE THIS MORNING...THE FORECAST AREA IS NOW LARGELY PRECIPITATION
FREE AS THE HEAVY OVERNIGHT RAINFALL HAS ENDED AND PUSHED OFF TO
THE EAST. THERE IS AN AREA OF WEAKENING RETURNS ATTEMPTING TO MOVE
IN FROM THE WEST...BUT THIS HAS BEEN ON A DISTINCT DOWNWARD TREND
OVER THE PAST FEW HOURS AND SHOULD AMOUNT TO VERY LITTLE ACROSS
SOUTHEAST GEORGIA. THE MAIN STORY FOR TODAY REVOLVES AROUND THE
COLD FRONT TO THE WEST AND ITS EVENTUAL IMPACT ON THE FORECAST
AREA LATER THIS AFTERNOON. BASED ON MORNING SURFACE ANALYSIS AND
CURRENT REGIONAL OBSERVATIONS...THE FRONT HAS PUSHED THROUGH
BIRMINGHAM AND WILL CONTINUE TO PROGRESS QUICKLY EASTWARD. THE
FRONT IS POSITIONED WITHIN THE UPPER LEVEL SYSTEM WHERE A DISTINCT
MID/UPPER LEVEL DRY SLOT IS RAPIDLY IMPINGING IN FROM THE WEST.
THE DRIER AIR ALOFT...ACCORDING TO WATER VAPOR IMAGERY...IS NOW
BEGINNING TO MOVE INTO GEORGIA AND WILL REACH OUR AREA BY THE
AFTERNOON. THERE CONTINUES TO BE CONSIDERABLE CLOUD COVER ACROSS
MOST OF THE REGION...THOUGH VISIBLE SATELLITE SHOWS AN AREA OF
CLEARING AHEAD OF THE FRONT THAT IS NOW ENTERING CENTRAL GEORGIA.
IN ADDITION TO THE UNCERTAIN CLOUD COVER FORECAST TODAY...ANOTHER
COMPLICATING FACTOR IS THE AREA OF CONSOLIDATING CONVECTION OVER
NORTH FLORIDA AND THE NORTHEASTERN GULF OF MEXICO. BACK TO OUR
WEST...RADAR IMAGERY IS PRIMARILY CLEAN SO IT APPEARS IT WILL
REQUIRE SOME SURFACE HEATING AND SURFACE INSTABILITY DEVELOPMENT
FOR SHOWERS AND THUNDERSTORMS TO START THERE. ONE OF THE MAIN
QUESTIONS IS TO WHAT DEGREE DOES THE CONVECTION TO THE SOUTH
INTERRUPT NORTHWARD MOISTURE TRANSPORT AND IMPACT
COVERAGE/INTENSITY OF DEVELOPMENT ACROSS THE FORECAST AREA THIS AFTERNOON.
HI-RES MODELS SEEM TO BE CAPTURING THE CURRENT PICTURE THE BEST.
THE RAP KEEP THE HEAVIEST PRECIPITATION WELL TO OUR SOUTH WITH
ONLY VERY MINIMAL DEVELOPMENT ALONG THE FRONT IN THE MID TO LATE
AFTERNOON HOURS. LOOKING AT SOME RAP SOUNDINGS SHOWS THAT THERE IS
A CAP IN PLACE THIS AFTERNOON ACROSS MUCH OF THE AREA.
HOWEVER...THIS SHOULD EASILY BE OVERCOME IF WE ARE ABLE TO GET
SOME SUN AND WARM UP. LOW LEVEL THICKNESS VALUES WOULD SUPPORT
TEMPS IN THE LOW 80S...SO ANY BREAKS IN THE CLOUD COVER WOULD
LIKELY RESULT IN RAPID TEMPERATURE RISES. THE MAX TEMP FORECAST
HAS BEEN ADJUSTED A BIT...BUT I STILL THINK WE WILL SEE MID/UPPER
70S IN MOST AREAS. TEMPS GETTING INTO THE LOW 70S WILL LIKELY
YIELD CAPE VALUES SOMEWHERE IN THE NEIGHBORHOOD OF 1000-1200 J/KG
THIS AFTERNOON. SO I THINK WE WILL SEE SCATTERED
THUNDERSTORMS...BUT THE OVERALL MODEL REPRESENTATION WOULD SUPPORT
ONLY MODEST UPDRAFTS. DEEP LAYER SHEAR CERTAINLY INCREASES WITH
0-6 KM VALUE INTO THE 50 KT RANGE SO THE AMBIENT ENVIRONMENT WOULD
SUPPORT A SEVERE THUNDERSTORM OR TWO. BUT... IT APPEARS LESS
LIKELY THAT THE SEVERE THREAT WILL BECOME VERY WIDESPREAD GIVEN
THE CLOUD COVER AND POTENTIAL FOR INSTABILITY TO BE LACKING.
OVERNIGHT...THE CLOSED UPPER LOW WILL MOVE ACROSS THE SOUTHERN
MID-ATLANTIC REGION...WITH THE SURFACE LOW LIFTING NORTHEAST TO
THE MID-ATLANTIC COAST AND ITS TRAILING COLD FRONT PUSHING WELL
OFF THE SOUTHEAST COAST. SIGNIFICANT DRYING WILL OCCUR...WITH
STRONG COLD AIR ADVECTION IN WAKE OF THE FRONT CAUSING BREEZY
CONDITIONS TO DEVELOP AND TEMPERATURES TO DROP OFF LATE TO LOWS IN
THE MID TO UPPER 40S WITH SOME LOWER 50S NEAR THE IMMEDIATE COAST.
LAKE WINDS...A LAKE WIND ADVISORY HAS BEEN ISSUED FOR LAKE
MOULTRIE BEGINNING AFTER MIDNIGHT AS STRONG COLD AIR ADVECTION
DEVELOPS IN WAKE OF A DEPARTING COLD FRONT.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
DRY HIGH PRESSURE WILL SURGE INTO THE AREA ON SUNDAY AS THE UPPER
LEVEL RIDGE TAKES HOLD. ALTHOUGH WEAK COLD ADVECTION IS FORECAST...
STRONG 35-40 KT DOWNSLOPE FLOW CENTERED AROUND 850 MB WILL PRODUCE
CONSIDERABLE ADIABATIC HEATING. HIGH TEMPERATURES WILL CLIMB INTO
THE LOWER 70S IN SOUTHEAST GA WITH UPPER 60S ELSEWHERE. MODEL
SOUNDINGS INDICATE A NEARLY 6000 FT MIXED LAYER DURING THE DAYTIME
HOURS. WITH GEOSTROPHIC WINDS PROGGED AT 35-40 KT THIS WILL YIELD
WINDY CONDITIONS WITH SUSTAINED WINDS OF 15-20 KT AND SOME GUSTS
APPROACHING 30 KT. WINDS WILL CALM DOWN SUNDAY EVENING.
AS THE SURFACE HIGH BUILDS IN SUNDAY NIGHT...CLEAR SKIES AND
DIMINISHING WINDS SUPPORT FAIRLY GOOD RADIATIONAL COOLING OVERNIGHT.
MONDAY MORNING LOWS COULD DROP INTO THE UPPER 30S FAR INLAND WITH
LOWER 40S MOST EVERYWHERE ELSE.
MONDAY THROUGH TUESDAY A STRONG DEEP LAYERED RIDGE WILL BUILD OVER
THE SOUTHEAST UNITED STATES...PROVIDING INCREASING LOW-LEVEL
THICKNESSES AND AMPLE SUNSHINE. HIGH TEMPS WILL WARM INTO THE
MID/UPPER 70S ON MONDAY AND LIKELY INTO THE LOWER 80S ON TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
DEEP LAYERED RIDGING WILL PERSIST TUESDAY NIGHT THROUGH THURSDAY
NIGHT WITH ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS. A
PROGRESSIVE UPPER LOW WILL MOVE THROUGH THE OHIO VALLEY LATE IN THE
WEEK...PUSHING A COLD FRONT THROUGH THE AREA FRIDAY OR FRIDAY NIGHT.
THIS MAY BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA BEFORE
DRY HIGH PRESSURE REBUILDS NEXT WEEKEND.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
KCHS...CEILINGS WILL CONTINUE ALTERNATE BETWEEN IFR AND MVFR FOR
ANOTHER FEW HOURS AND THE FORECAST HAS BEEN AMENDED ACCORDINGLY.
THEN...CEILINGS SHOULD LIFT TO PREVAILING MVFR LEVELS...WITH
FURTHER IMPROVEMENT TO VFR LEVELS AFTER 19Z. SHOWERS AND PERHAPS A
FEW THUNDERSTORMS ARE EXPECTED TO IMPACT THE TERMINAL AHEAD OF AN
APPROACHING COLD FRONT IN THE 22-02Z TIME FRAME...TEMPORARILY
REDUCING CEILINGS AND/OR VISIBILITIES. BREEZY SOUTHWEST TO WEST
WINDS ARE EXPECTED BEGINNING THIS AFTERNOON AND CONTINUING THROUGH
THE END OF THE FORECAST PERIOD...WITH GUSTS UPWARDS OF AROUND 20
KT.
KSAV...CEILINGS WILL CONTINUE TO ALTERNATE BETWEEN IFR AND MVFR
FOR ANOTHER FEW HOURS...BEFORE LIFTING TO VFR LEVELS AFTER 16Z.
SHOWERS AND PERHAPS A FEW THUNDERSTORMS ARE EXPECTED TO IMPACT THE
TERMINAL AHEAD OF AN APPROACHING COLD FRONT IN THE 21-01Z TIME
FRAME...TEMPORARILY REDUCING CEILINGS AND/OR VISIBILITIES. BREEZY
SOUTHWEST TO WEST WINDS ARE EXPECTED BEGINNING THIS AFTERNOON AND
CONTINUING THROUGH THE END OF THE FORECAST PERIOD...WITH GUSTS
UPWARDS OF 20-25 KT.
EXTENDED AVIATION OUTLOOK...VFR CONDITIONS EXPECTED. WINDY
CONDITIONS AT BOTH TERMINALS ON SUNDAY.
&&
.MARINE...
TODAY AND TONIGHT...A SOUTH TO SOUTHWEST FLOW WILL STRENGTHEN
THROUGH THIS EVENING AHEAD OF AN APPROACHING COLD FRONT. WINDS
WILL THEN VEER WEST-NORTHWEST LATE THIS EVENING AND OVERNIGHT AS
THE FRONT SHIFTS OFFSHORE...WITH STRONG COLD AIR ADVECTION
DEVELOPING IN WAKE OF THE FRONT. SMALL CRAFT ADVISORIES ARE
ALREADY IN EFFECT FOR THE NEAR SHORE SC WATERS AND THE OUTER GA
WATERS FOR SEAS OF 6 FT OR GREATER DUE TO PERSISTENT SOUTHEAST
SWELL...BUT ALL WATERS INCLUDING CHARLESTON HARBOR WILL BE UNDER A
SMALL CRAFT ADVISORY LATER TONIGHT DUE TO ELEVATED WINDS AND/OR
SEAS. THERE IS EVEN A LOW PROBABILITY OF WINDS BRIEFLY GUSTING TO
GALE FORCE IN THE OUTER GA WATERS LATE TONIGHT.
CONDITIONS WILL REMAIN FAVORABLE FOR SEA FOG UNTIL THE COLD FRONT
CROSSES THE WATERS WITH MUCH DRIER AIR THIS EVENING. THE FORECAST
INDICATES PATCHY FOG...BUT MORE WIDESPREAD FOG COULD PROMPT DENSE
FOG MARINE ADVISORIES.
SUNDAY THROUGH WEDNESDAY...ELEVATED WINDS/SEAS WILL PERSIST THROUGH
SUNDAY...THEN TAPER OFF THROUGH SUNDAY NIGHT AS THE SURFACE HIGH
BUILDS OVER THE WATERS. SMALL CRAFT ADVISORIES ARE IN EFFECT FOR ALL
MARINE ZONES ON SUNDAY BEFORE DROPPING OFF BY MIDNIGHT. FAIRLY QUIET
CONDITIONS THEN EXPECTED THROUGH WEDNESDAY NIGHT BEFORE A SOUTHERLY
JET INCREASES WINDS AND SEAS THURSDAY INTO FRIDAY AHEAD OF A COLD
FRONT. MARINE FLAGS WILL BE POSSIBLE AGAIN THURSDAY/FRIDAY.
&&
.FIRE WEATHER...
ON SUNDAY...AS THE UPPER RIDGE BEGINS TO BUILD INTO THE AREA...
DOWNSLOPE SUBSIDENCE WILL STRETCH THE MIXED LAYER TO ABOUT 6000 FT.
THIS WILL ALLOW DEWPOINTS TO MIX DOWN INTO THE 30S DURING THE DAY
WHILE ALSO TAPPING INTO FAIRLY STRONG WINDS ALOFT. CURRENT MINIMUM
RH FORECAST SHOWS MID/UPPER 20S ON SUNDAY WITH NW WINDS OF 15 TO 20
MPH WITH SOME GUSTS AS HIGH AS 30 MPH. THE FUELS WILL PROBABLY BE
TOO WET FROM ONGOING RAIN TO MAKE FOR A SIGNIFICANT FIRE DANGER
THOUGH CONDITIONS WILL NEED TO BE MONITORED.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT
SUNDAY NIGHT FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR AMZ352.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR
AMZ350-374.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM EDT SUNDAY
FOR AMZ354.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO MIDNIGHT EDT
SUNDAY NIGHT FOR AMZ330.
&&
$$
SYNOPSIS...
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...JAQ/JRL
MARINE...JAQ/JRL
FIRE WEATHER...
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
940 AM EDT SAT MAR 29 2014
.UPDATE...
LATEST MODEL GUIDANCE IS SUGGESTING THE DIMINISHING PRECIP OVER THE
CWA WILL CONTINUE WITH THE MORE WIDESPREAD AREA OF SHOWERS REMAINING
ACROSS EXTREME NORTH GEORGIA AND SCATTERED SHOWERS DEVELOPING
ELSEWHERE. THE PRECIP WILL END FROM THE WEST THIS AFTERNOON AS DRIER
AIR SPREADS INTO THE CWA. THERE REMAINS A SLIGHT RISK OF
THUNDERSTORMS OVER THE SOUTHEASTERN PART OF THE CWA. HAVE THEREFORE
ADJUSTED POPS FOR THE REST OF TODAY. NO OTHER CHANGES PLANNED.
17
&&
.PREV DISCUSSION... /ISSUED 339 AM EDT SAT MAR 29 2014/
SHORT TERM /TODAY THROUGH SUNDAY/...
500MB ANALYSIS SHOWS A POTENT SHORTWAVE ACROSS CENTRAL MS EARLY THIS
MORNING. THIS FEATURE IS ASSOCIATED WITH AN MCS MOVING INTO WESTERN
AL. THE CONVECTIVE ACTIVITY HAS DEVELOPED PRETTY FAR AHEAD OF THE
COLD FRONT WHICH IS CURRENTLY STILL ACROSS THE ARKLATEX ALONG WITH
THE DEVELOPING WAVE OF LOW PRESSURE.
THE SHORTWAVE WILL CONTINUE EAST TODAY AND MOVE ACROSS GA DURING THE
FIRST PART OF THE DAY. THE ASSOCIATED COLD POOL WILL STEEPEN MID
LEVEL LAPSE RATES SIGNIFICANTLY.
THE HRRR SEEMS TO HAVE A DECENT HANDLE ON THE CONVECTIVE ACTIVITY TO
THE WEST AND HAVE FOLLOWED FAIRLY CLOSELY FOR POPS. THE MAIN ISSUE
WILL BE THE POTENTIAL FOR SEVERE. STILL THINK THE BEST POTENTIAL FOR
SEVERE WILL BE THE EXTREME SOUTHEAST PORTION OF THE CWFA.
HOWEVER...ANOTHER THING TO CONSIDER WILL BE THE MOVEMENT OF THE
ACTIVITY ACROSS EASTERN MS/WESTERN AL. IF THE MCS CONTINUES TO SHIFT
TO THE SE...THIS COULD HELP LIMIT THE DEVELOPMENT OF WIDESPREAD
CONVECTION ACROSS THE CWFA.
NEWEST RUNS OF THE HRRR DO TAKE THE STRONGEST ACTIVITY ACROSS
SOUTHERN GA AND THE FLORIDA PANHANDLE DURING THE MORNING HOURS. THIS
WOULD MEAN THAT A FEW STRONG/ISOLATED SEVERE STORMS...ARE POSSIBLE
ACROSS THE EXTREME SOUTHERN PART OF THE CWFA. IN ADDITION...BEHIND
THE INITIAL MCS BUT STILL AHEAD OF THE COLD FRONT...THE HRRR HAS
SCATTERED THUNDERSTORMS BREAKING OUT ACROSS THE SE...SO THE
POTENTIAL FOR STRONG STORMS/ISOLD SEVERE MAY LAST INTO THE MID TO
LATE AFTERNOON HOURS...WHEN THERE IS MORE POTENTIAL FOR BREAKS IN
THE CLOUDS AND FOR SURFACE DESTABILIZATION TO OCCUR. LUCKILY...SHEAR
VALUES ARE RATHER WEAK...WITH THE BEST VALUES ALONG THE LAGGING COLD
FRONT THIS EVENING. IF SEVERE THUNDERSTORMS ARE ABLE TO
DEVELOP...DAMAGING WIND GUSTS AND LARGE HAIL WOULD BE THE PRIMARY
THREATS.
THE HRRR DOES CLEAR OUT THE POPS A BIT FASTER THAN PREVIOUSLY
FORECAST. HAVE TRIED TO ACCOUNT FOR THIS IN TIMING. TEMPS IN THE NE
WILL DIP DOWN INTO THE MIDDLE 30S TONIGHT...BUT LUCKILY...THE
FORECAST SHOULD BE DRY. TOO MARGINAL TO ISSUE A FREEZE WATCH...AND
THE WINDS MAY STAY UP OVERNIGHT JUST ENOUGH TO LIMIT FROST
DEVELOPMENT.
NLISTEMAA
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE DOMINATES FOR THE BEGINNING OF THE EXTENDED. A WEAK
FRONT APPROACHES THE AREA ON TUESDAY BUT THE PRECIPITATION
ASSOCIATED WITH IT SHOULD DIMINISH BEFORE REACHING THE STATE.
SYSTEM OF INTEREST IN THE EXTENDED THOUGH IS NEAR THE END. BOTH
THE ECMWF AND THE GFS LIFT A SFC LOW OUT OF THE MIDWEST AND INTO
THE OHIO VALLEY/GREAT LAKES REGION ON FRIDAY AND PUSHES SHOWERS AND
THUNDERSTORMS ACROSS THE CWA AHEAD OF A COLD FRONT THATS PROGGED
TO MOVE THROUGH FRIDAY NIGHT. STILL SOME DIFFERENCES BETWEEN THE
TWO MODELS IN TERMS OF FEATURE LOCATIONS...BUT OVERALL BOTH
SUGGEST A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE
WEEK. WILL HAVE TO CAREFULLY MONITOR FRIDAY FOR SEVERE WEATHER
POTENTIAL AS THE GFS INDICATES UP TO 2000 J/KG OF MUCAPE ON
FRIDAY WITH 30-40KTS OF LOW LEVEL SHEAR.
11
&&
.AVIATION...
12Z UPDATE...
LOW PRESSURE AND COLD FRONT CURRENTLY ACROSS CETRAL MS EARLY THIS
MORNING. THE FRONT AND LOW CENTER WILL MOVE EAST THROUGH THE
DAY...AND FINALLY EAST OF THE REGION EARLY THIS EVENING. MCS THAT
DEVELOPED AHEAD OF THE BOUNDARY HAS WEAKENED CONSIDERABLY OVER THE
LAST FEW HOURS...WITH THE LIGHTNING DYING OFF. AM STILL A LITTLE
CONCERNED WITH RE-DEVELOPMENT OF SHOWERS BETWEEN THE EXITING MCS
AND THE APPROACHING COLD FRONT. WINDS SHOULD GO W BY MID
MORNING...AND EVENTUALLY NW THIS EVENING.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 39 66 37 / 100 20 0 0
ATLANTA 65 39 64 42 / 100 10 0 0
BLAIRSVILLE 59 33 57 32 / 100 30 0 0
CARTERSVILLE 62 37 64 34 / 90 10 0 0
COLUMBUS 69 42 68 42 / 100 10 0 0
GAINESVILLE 63 38 64 40 / 100 20 0 0
MACON 70 42 67 37 / 100 10 0 0
ROME 62 37 65 34 / 80 10 0 0
PEACHTREE CITY 66 38 65 34 / 100 10 0 0
VIDALIA 72 45 69 41 / 80 30 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
737 AM EDT SAT MAR 29 2014
.PREV DISCUSSION... /ISSUED 339 AM EDT SAT MAR 29 2014/
SHORT TERM /TODAY THROUGH SUNDAY/...
500MB ANALYSIS SHOWS A POTENT SHORTWAVE ACROSS CENTRAL MS EARLY THIS
MORNING. THIS FEATURE IS ASSOCIATED WITH AN MCS MOVING INTO WESTERN
AL. THE CONVECTIVE ACTIVITY HAS DEVELOPED PRETTY FAR AHEAD OF THE
COLD FRONT WHICH IS CURRENTLY STILL ACROSS THE ARKLATEX ALONG WITH
THE DEVELOPING WAVE OF LOW PRESSURE.
THE SHORTWAVE WILL CONTINUE EAST TODAY AND MOVE ACROSS GA DURING THE
FIRST PART OF THE DAY. THE ASSOCIATED COLD POOL WILL STEEPEN MID
LEVEL LAPSE RATES SIGNIFICANTLY.
THE HRRR SEEMS TO HAVE A DECENT HANDLE ON THE CONVECTIVE ACTIVITY TO
THE WEST AND HAVE FOLLOWED FAIRLY CLOSELY FOR POPS. THE MAIN ISSUE
WILL BE THE POTENTIAL FOR SEVERE. STILL THINK THE BEST POTENTIAL FOR
SEVERE WILL BE THE EXTREME SOUTHEAST PORTION OF THE CWFA.
HOWEVER...ANOTHER THING TO CONSIDER WILL BE THE MOVEMENT OF THE
ACTIVITY ACROSS EASTERN MS/WESTERN AL. IF THE MCS CONTINUES TO SHIFT
TO THE SE...THIS COULD HELP LIMIT THE DEVELOPMENT OF WIDESPREAD
CONVECTION ACROSS THE CWFA.
NEWEST RUNS OF THE HRRR DO TAKE THE STRONGEST ACTIVITY ACROSS
SOUTHERN GA AND THE FLORIDA PANHANDLE DURING THE MORNING HOURS. THIS
WOULD MEAN THAT A FEW STRONG/ISOLATED SEVERE STORMS...ARE POSSIBLE
ACROSS THE EXTREME SOUTHERN PART OF THE CWFA. IN ADDITION...BEHIND
THE INITIAL MCS BUT STILL AHEAD OF THE COLD FRONT...THE HRRR HAS
SCATTERED THUNDERSTORMS BREAKING OUT ACROSS THE SE...SO THE
POTENTIAL FOR STRONG STORMS/ISOLD SEVERE MAY LAST INTO THE MID TO
LATE AFTERNOON HOURS...WHEN THERE IS MORE POTENTIAL FOR BREAKS IN
THE CLOUDS AND FOR SURFACE DESTABILIZATION TO OCCUR. LUCKILY...SHEAR
VALUES ARE RATHER WEAK...WITH THE BEST VALUES ALONG THE LAGGING COLD
FRONT THIS EVENING. IF SEVERE THUNDERSTORMS ARE ABLE TO
DEVELOP...DAMAGING WIND GUSTS AND LARGE HAIL WOULD BE THE PRIMARY
THREATS.
THE HRRR DOES CLEAR OUT THE POPS A BIT FASTER THAN PREVIOUSLY
FORECAST. HAVE TRIED TO ACCOUNT FOR THIS IN TIMING. TEMPS IN THE NE
WILL DIP DOWN INTO THE MIDDLE 30S TONIGHT...BUT LUCKILY...THE
FORECAST SHOULD BE DRY. TOO MARGINAL TO ISSUE A FREEZE WATCH...AND
THE WINDS MAY STAY UP OVERNIGHT JUST ENOUGH TO LIMIT FROST
DEVELOPMENT.
NLISTEMAA
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE DOMINATES FOR THE BEGINNING OF THE EXTENDED. A WEAK
FRONT APPROACHES THE AREA ON TUESDAY BUT THE PRECIPITATION
ASSOCIATED WITH IT SHOULD DIMINISH BEFORE REACHING THE STATE.
SYSTEM OF INTEREST IN THE EXTENDED THOUGH IS NEAR THE END. BOTH
THE ECMWF AND THE GFS LIFT A SFC LOW OUT OF THE MIDWEST AND INTO
THE OHIO VALLEY/GREAT LAKES REGION ON FRIDAY AND PUSHES SHOWERS AND
THUNDERSTORMS ACROSS THE CWA AHEAD OF A COLD FRONT THATS PROGGED
TO MOVE THROUGH FRIDAY NIGHT. STILL SOME DIFFERENCES BETWEEN THE
TWO MODELS IN TERMS OF FEATURE LOCATIONS...BUT OVERALL BOTH
SUGGEST A GOOD CHANCE OF SHOWERS AND THUNDERSTORMS LATE IN THE
WEEK. WILL HAVE TO CAREFULLY MONITOR FRIDAY FOR SEVERE WEATHER
POTENTIAL AS THE GFS INDICATES UP TO 2000 J/KG OF MUCAPE ON
FRIDAY WITH 30-40KTS OF LOW LEVEL SHEAR.
11
&&
.AVIATION...
12Z UPDATE...
LOW PRESSURE AND COLD FRONT CURRENTLY ACROSS CETRAL MS EARLY THIS
MORNING. THE FRONT AND LOW CENTER WILL MOVE EAST THROUGH THE
DAY...AND FINALLY EAST OF THE REGION EARLY THIS EVENING. MCS THAT
DEVELOPED AHEAD OF THE BOUNDARY HAS WEAKENED CONSIDERABLY OVER THE
LAST FEW HOURS...WITH THE LIGHTNING DYING OFF. AM STILL A LITTLE
CONCERNED WITH RE-DEVELOPMENT OF SHOWERS BETWEEN THE EXITING MCS
AND THE APPROACHING COLD FRONT. WINDS SHOULD GO W BY MID
MORNING...AND EVENTUALLY NW THIS EVENING.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ALL ELEMENTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 66 39 66 37 / 100 20 0 0
ATLANTA 65 39 64 42 / 100 10 0 0
BLAIRSVILLE 59 33 57 32 / 100 30 0 0
CARTERSVILLE 62 37 64 34 / 90 10 0 0
COLUMBUS 69 42 68 42 / 100 10 0 0
GAINESVILLE 63 38 64 40 / 100 20 0 0
MACON 70 42 67 37 / 100 10 0 0
ROME 62 37 65 34 / 80 10 0 0
PEACHTREE CITY 66 38 65 34 / 100 10 0 0
VIDALIA 72 45 69 41 / 80 30 0 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
637 AM EDT SAT MAR 29 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A COLD FRONT. THE FRONT WILL MOVE
THROUGH THE FORECAST AREA THIS EVENING. HIGH PRESSURE AND DRY
CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ISENTROPIC LIFT WILL SUPPORT NUMEROUS SHOWERS EARLY THIS MORNING.
THE MESOSCALE CONVECTIVE COMPLEX APPROACHING THE FORECAST AREA
FROM THE WEST SHOULD REACH THE AREA LATE THIS MORNING. RADAR
TRENDS AND THE LATEST HRRR INDICATE THE STRONGER CONVECTION WILL
REMAIN SOUTH OF THE AREA. STRONGER CONVERGENCE AHEAD OF THE COLD
FRONT SHOULD BEGIN TO ENTER THE FORECAST AREA FROM THE WEST AROUND
THE MIDDLE OF THE AFTERNOON. SHEAR WILL BE HIGH WITH H85 WINDS OF
30 TO 40 KNOTS SUPPORTING POSSIBLE SEVERE THUNDERSTORMS. THE
THREAT APPEARS LIMITED BECAUSE IT IS QUESTIONABLE HOW MUCH MOISTURE
AND INSTABILITY RECOVERY WILL OCCUR IN THE WAKE OF THE LARGE COMPLEX
THIS MORNING. THE THREAT OF THUNDERSTORMS WILL CONTINUE INTO THE
EVENING WITH THE COLD FRONT IN THE AREA AND COOLING ALOFT
ASSOCIATED WITH THE UPPER-LEVEL TROUGH. DRYING SHOULD OCCUR LATER
IN THE EVENING BEHIND THE COLD FRONT. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY THROUGH SUNDAY
NIGHT. IT WILL BE BREEZY SUNDAY AND A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED. THE GFS AND NAM MOS SUPPORT WINDS OF 15 TO 25
KNOTS. WINDS SHOULD DIMINISH SUNDAY NIGHT AS THE HIGH GETS CLOSER
TO THE AREA AND THE PRESSURE GRADIENT WEAKENS. STRONG NET
RADIATIONAL COOLING CONDITIONS SHOULD DEVELOP LATE. USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. EXPECT LOWS IN
THE MID AND UPPER 30S SUNDAY NIGHT WITH SCATTERED FROST. A FROST
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. WARMER TEMPERATURES SHOULD
OCCUR AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO
MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER
70S TO AROUND 80.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS ACROSS THE MIDLANDS AND CSRA ARE DIMINISHING FROM THE WEST
THIS MORNING. ABUNDANT LOW-LEVEL MOISTURE THIS MORNING HAS
CONTRIBUTED TO IFR/LIFR CIGS WITH SOME IFR VSBYS. MVFR CONDITIONS
EXPECTED TO RETURN AROUND 16Z AS SOUTHERLY WINDS INCREASE AHEAD OF
THE APPROACHING COLD FRONT. THERE SHOULD BE AN AREA SHOWERS/FEW
TSTMS TO CROSS THE TAF SITES DURING THE AFTERNOON AHEAD OF THE
COLD FRONT. THE COLD FRONT WILL CROSS THE TAF SITES BY EARLY
EVENING. VFR CONDITIONS ACROSS THE AREA BY THE END OF THE TAF
PERIOD.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS OVER THE AREA POSSIBLE
IN THE WAKE OF THE FRONT SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
625 AM EDT SAT MAR 29 2014
.SYNOPSIS...
MOISTURE WILL BE HIGH AHEAD OF A COLD FRONT. THE FRONT WILL MOVE
THROUGH THE FORECAST AREA THIS EVENING. HIGH PRESSURE AND DRY
CONDITIONS WILL PREVAIL SUNDAY AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
ISENTROPIC LIFT WILL SUPPORT NUMEROUS SHOWERS EARLY THIS MORNING.
THE MESOSCALE CONVECTIVE COMPLEX APPROACHING THE FORECAST AREA
FROM THE WEST SHOULD REACH THE AREA LATE THIS MORNING. RADAR
TRENDS AND THE LATEST HRRR INDICATE THE STRONGER CONVECTION WILL
REMAIN SOUTH OF THE AREA. STRONGER CONVERGENCE AHEAD OF THE COLD
FRONT SHOULD BEGIN TO ENTER THE FORECAST AREA FROM THE WEST AROUND
THE MIDDLE OF THE AFTERNOON. SHEAR WILL BE HIGH WITH H85 WINDS OF
30 TO 40 KNOTS SUPPORTING POSSIBLE SEVERE THUNDERSTORMS. THE
THREAT APPEARS LIMITED BECAUSE IT IS QUESTIONABLE HOW MUCH MOISTURE
AND INSTABILITY RECOVERY WILL OCCUR IN THE WAKE OF THE LARGE COMPLEX
THIS MORNING. THE THREAT OF THUNDERSTORMS WILL CONTINUE INTO THE
EVENING WITH THE COLD FRONT IN THE AREA AND COOLING ALOFT
ASSOCIATED WITH THE UPPER-LEVEL TROUGH. DRYING SHOULD OCCUR LATER
IN THE EVENING BEHIND THE COLD FRONT. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
HIGH PRESSURE WILL BUILD OVER THE AREA SUNDAY THROUGH SUNDAY
NIGHT. IT WILL BE BREEZY SUNDAY AND A LAKE WIND ADVISORY WILL
LIKELY BE NEEDED. THE GFS AND NAM MOS SUPPORT WINDS OF 15 TO 25
KNOTS. WINDS SHOULD DIMINISH SUNDAY NIGHT AS THE HIGH GETS CLOSER
TO THE AREA AND THE PRESSURE GRADIENT WEAKENS. STRONG NET
RADIATIONAL COOLING CONDITIONS SHOULD DEVELOP LATE. USED THE
GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST. EXPECT LOWS IN
THE MID AND UPPER 30S SUNDAY NIGHT WITH SCATTERED FROST. A FROST
ADVISORY MAY BE NEEDED.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
THE GFS AND ECMWF INDICATE DRY HIGH PRESSURE SHOULD DOMINATE
DURING MUCH OF THE PERIOD. MOISTURE SHOULD BE ON THE INCREASE LATE
IN THE PERIOD AHEAD OF A COLD FRONT. WARMER TEMPERATURES SHOULD
OCCUR AS THE HIGH SHIFTS EASTWARD AND THE AIR MASS CONTINUES TO
MODIFY. THE GFS...ECMWF... AND EKD MOS SUPPORT HIGHS IN THE UPPER
70S TO AROUND 80.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
SHOWERS ACROSS THE MIDLANDS AND CSRA ARE DIMINISHING FROM THE WEST
THIS MORNING. ABUNDANT LOW-LEVEL MOISTURE THIS MORNING HAS
CONTRIBUTED TO IFR/LIFR CIGS. MVFR CONDITIONS EXPECTED TO RETURN
AROUND 16Z AS SOUTHERLY WINDS INCREASE AHEAD OF THE APPROACHING COLD
FRONT. THERE SHOULD BE AN AREA SHOWERS/FEW TSTMS TO CROSS THE TAF
SITES DURING THE AFTERNOON AHEAD OF THE COLD FRONT. THE COLD FRONT
WILL CROSS THE TAF SITES BY EARLY EVENING. VFR CONDITIONS ACROSS THE
AREA BY THE END OF THE TAF PERIOD.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS OVER THE AREA POSSIBLE
IN THE WAKE OF THE FRONT SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1103 AM CDT SAT MAR 29 2014
.DISCUSSION...
302 AM CDT
TODAY...
THIS MORNING...RIDGE OF HIGH PRESSURE EXTENDS FROM LAKE SUPERIOR
INTO THE MID MISSOURI VALLEY WHILE LOW PRESSURE LIES OVER
MISSISSIPPI/ALABAMA. THIS LOW WILL LIFT NORTH INTO THE UPPER OHIO
VALLEY TODAY RESULTING IN NORTHEASTERLY WINDS OFF OF LAKE MICHIGAN
THROUGH THE DAY. SOME PRECIP MAY BRUSH THE FAR SOUTHEASTERN COUNTIES
THIS MORNING...MAINLY IN THE FORM OF SNOW...THOUGH ANY ACCUMULATION
WILL LIKELY BE CONFINED TO GRASSY AREAS AND ONLY A DUSTING IS
EXPECTED. SPLIT CHANNEL IR IMAGERY SHOWS STRATUS STILL SPANS MUCH OF
THE UPPER MIDWEST...AS FAR WEST AS CENTRAL IOWA AND NORTHWEST INTO
CENTRAL WISCONSIN. EXPECT CLOUD COVER TO LINGER THROUGH AT LEAST
MIDDAY...THEN ANTICYCLONIC FLOW WITH THE RIDGE AXIS SHOULD START TO
BUILD IN FROM THE NORTHWEST THIS AFTERNOON AND EVENING WITH SKIES
CLEARING. TEMPERATURES TODAY ARE EXPECTED TO WARM INTO THE LOW TO
MID 40S...THOUGH WILL STAY IN THE 30S NEAR THE LAKE WITH THE
OFFSHORE FLOW THROUGH THE DAY.
SUNDAY AND MONDAY...
COMPACT UPPER WAVE WILL MOVE ONSHORE OVER SOCAL EARLY SUNDAY...THEN
TRANSLATE EAST ACROSS THE CENTRAL PLAINS BY MONDAY. SURFACE LOW WILL
DEEPEN IN RESPONSE OVER THE CENTRAL PLAINS THROUGH THE PERIOD WITH
STRONG WARM ADVECTION INTO THE REGION HELPING TO AMPLIFY THE
MID/UPPER LEVEL RIDGING. H85 TEMPS WILL WARM TO AROUND 10C BY SUNDAY
EVENING...AND 12C TO 13C BY MONDAY. CLIMO FROM NARR DATASET SHOWS
MEDIAN TEMPS IN THE LOW 70S WHEN H85 TEMPS EXCEED AROUND 9C FOR THE
LATTER HALF OF MARCH. WHILE THESE WARMER TEMPERATURES ALOFT WILL
ARRIVE LATER IN THE DAY SUNDAY...THEY SHOULD BE DIRECTLY OVERHEAD ON
MONDAY WHICH IS EXPECTED TO BE THE WARMEST DAY IN SOME TIME. BACKED
OFF SLIGHTLY ON TEMPS FOR SUNDAY...AND WHILE I THINK AREAS
ESPECIALLY IN THE WESTERN CWA STILL HAVE A GOOD CHANCE OF 60...IT
MAY STRUGGLE TO REACH 60 IN CHICAGO AND EASTERN PORTIONS OF THE CWA
DUE TO THE SLOWER ARRIVAL. THE MAIN CONCERNS FOR TEMPS MONDAY REVOLVE
AROUND CONVECTIVE CHANCES AND CLOUD COVER WHICH WILL INHIBIT HOW
WARM WE GET. H5 VORT TAKES ON A NEGATIVE TILT MONDAY AS IT LIFTS
ACROSS THE MID-MISSOURI VALLEY AND LEFT EXIT REGION OF UPPER JET
OVER THE AREA WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. LATEST
THINKING ON TIMING OF THE LOW STILL HAS THE BETTER FORCING WELL TO
THE WEST DURING PEAK HEATING WHEN SOME VERY MODEST SURFACE BASED
INSTABILITY EXISTS. WITH THUNDERSTORMS DEVELOPING TO THE
WEST...COULD SEE CIRRUS STREAMING OVERHEAD DURING THE DAY MONDAY
WHICH WILL IMPACT TEMPS. WITH A PRETTY DYNAMIC SYSTEM...MAY BE ABLE
TO OVERCOME THE LACK OF FAVORABLE THERMODYNAMICS FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP...PARTICULARLY IN THE LATER
AFTERNOON AND EVENING. REFINED POPS TO REFLECT THESE TIMING DETAILS
BUT MAINTAINED 20 TO 30 PERCENT DUE TO COVERAGE CONCERNS. AS FAR AS
TEMPS...REMAIN ON THE WARM SIDE OF THE SOLUTION ENVELOPE BUT WILL
HOLD OFF ON GOING ABOVE GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND
UNCERTAINTY IN PRECIP. WINDS WILL BECOME PROGRESSIVELY BREEZY
THROUGH THIS PERIOD...WITH GUSTS TO AROUND 20 MPH POSSIBLE ON SUNDAY
AND EVEN BREEZIER CONDITIONS ON MONDAY. 50KT WINDS ARE NOTED AROUND
900MB MONDAY...AND WITH DEEP MIXING POSSIBLE...THE AREA MAY SEE
30MPH+ GUSTS AT THE SURFACE DURING THE AFTERNOON.
TUESDAY THROUGH FRIDAY...
AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THE UPCOMING WORK WEEK AS A SERIES OF WAVES PROGRESS ACROSS THE
REGION. STILL CONSIDERABLE TIMING/TRACK DIFFERENCES THOUGH GUIDANCE
DOES SEEM TO BE FAVORING A MORE SOUTHERLY/COOLER PATTERN...
ESPECIALLY THE GFS WITH GOOD SUPPORT FROM THE GEFS. THE EMCWF
MAINTAINS A WARMER SOLUTION...WITH BAROCLINIC ZONE VERY NEAR
RESULTING IN A DECENT TEMPS SPREAD NORTH TO SOUTH ACROSS THE CWA.
CONTINUE TO RUN WITH A MODEL CONSENSUS BLEND FOR TEMPS NEXT WEEK
GIVEN THE HIGH DEGREE OF UNCERTAINTY...WHICH RESULTS IN WELL BELOW
NORMAL TEMPS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* VARIABLE MVFR CIGS SCATTERING MID/LATE AFTERNOON.
* NORTHEAST WINDS CONTINUING THROUGH THE EVENING.
MDB
//DISCUSSION...UPDATED 12Z...
CIGS ARE STARTING TO BECOME MORE VARIABLE WITH SOME LIFTING OF
BASES OCCURRING AS WELL. CLEARING IS STARTING TO MARCH SOUTHWARD
DOWN THE LAKE AS WELL AND THIS LOOKS TO ARRIVE MID TO LATE
AFTERNOON AT ORD/MDW/DPA/GYY. RFD LOOKS TO IMPROVE TO VFR IN THE
NEXT HOUR OR SO.
MDB
FROM 12Z...
HIGH PRESSURE MOVING TOWARD THE AREA WILL SUPPORT GRADUALLY
CLEARING SKIES. WINDS REMAIN NORTH TO NORTHEAST FOR MOST OF THE
DAY AHEAD OF THE RIDGE...THEN TURN EAST TOMORROW BEHIND IT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN TIMING OF SCATTERING CIGS.
* HIGH CONFIDENCE IN WIND FORECAST.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF TSRA. GUSTY SOUTH WINDS.
TUESDAY...SLGT CHC OF RAIN DURING THE NIGHT.
WEDNESDAY...RAIN AND MVFR LIKELY.
THURSDAY AND FRIDAY...SLGT CHC OF RAIN AND SNOW.
LENNING
&&
.MARINE...
310 AM CDT
WINDS GENERALLY WILL REMAIN NORTHERLY OR NORTHEASTERLY TODAY AHEAD
OF AN APPROACHING HIGH PRESSURE RIDGE...THEN WILL VEER EAST AFTER
THE RIDGE PASSES EARLY SUNDAY. THE EAST OR SOUTHEAST FLOW THEN
PERSISTS THROUGH THE WEEKEND INTO EARLY NEXT WEEK. STRONG LOW
PRESSURE MOVES THROUGH THE NORTHERN PART OF THE LAKE MONDAY
NIGHT...LIKELY SUPPORTING A PERIOD OF GALES ON THE SOUTHERN HALF.
THE WARM SOUTHERLY FLOW AHEAD OF THE LOW MONDAY AFTERNOON WILL BE
VERY STRONG BUT MAY BE LESS EFFECTIVE AT CREATING GALES THAN THE
WEAKER BUT COLDER WINDS BEHIND THE LOW ON MONDAY NIGHT AND
TUESDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
1024 AM CDT Sat Mar 29 2014
.DISCUSSION...
ISSUED 1024 AM CDT Sat Mar 29 2014
Showers associated with low pressure in the eastern Tennessee
Valley has now shifted east into Indiana and have updated forecast
to reflect dry conditions across the entire CWA for the remainder
of the day. Plenty of stratus continues to plague the region again
today and main forecast issue is the potential for afternoon
clearing and associated affect on high temps. A sliver of clearing
is approaching the northern CWA but already starting to fill in
with SC and a larger batch of stratus over NE IL is quickly
advecting in behind this on NNE low level flow. Think clouds will
hang tough as long as low level flow remains out of N/NNE which
should last well into afternoon. As the low pulls further east
winds will eventually come around to N/NNW advecting in drier air
from NW IL and eastern IA, and subsidence off surface ridge to our
west should help break up cloud deck. With this in mind have
increased cloud cover through mid afternoon, lowered highs a
degree or two, and slowed diurnal temp rise.
25
&&
.AVIATION...
ISSUED 640 AM CDT Sat Mar 29 2014
MVFR cigs will continue at all TAF sites until sometime after 18z.
Vis is lower at some sites, so have a TEMPO group for PIA/DEC/CMI
and a TEMPO group for SPI with cigs below 1kft for a couple hours
this morning. Clouds will hopefully scatter out this afternoon as
models show some drier air advecting into the region; PIA and SPI
first, followed by CMI last. Skies will eventually become clear,
but not until the early evening time frame, right around sunset.
Clear skies will then continue til tomorrow mroning. Winds will be
northerly through the day, and then become light and variable
tonight. Wind speeds this morning will be around 10kts, but then
as the clouds scatter out, some mixing will occur and think that
all sites could see gusts to around 20kts. Light winds expected
tonight.
Auten
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT Sat Mar 29 2014
Surface low tracking across northern Mississippi early this
morning, while an upper trough moves through Iowa and western
Missouri. Area of showers streaming northward ahead of the upper
trough has made it up to around Taylorville and Sullivan as of 2
am, although the leading edge has had to fight some dry air to
make it that far.
A rather active weather pattern is on tap for next week, with
precipitation timing the primary forecast concern.
SHORT TERM...Today through Monday:
Will maintain some precipitation chances across the far eastern
CWA for the first few hours after sunrise, until the trough moves
into Illinois. Forecast soundings off the RAP model suggest some
rain/snow mix north of I-70 until the ice crystals are lost by mid
morning, with rain to the south. Otherwise, will see a decrease in
clouds from west to east this afternoon, as ridge axis moves
southeast out of the northern Plains.
Decent warm air advection sets up early Sunday as the high drifts
east of the state. With abundant sunshine, have sided more toward
the MAV MOS highs in the lower to mid 60s, with temperatures in
the mid to upper 60s on Monday. Monday looks to be fairly windy
ahead of the next storm system, with Bufkit data suggesting wind
gusts of 30-40 mph. Main surface low expected to track northeast
into southern Minnesota by late afternoon, with the trailing cold
front sweeping through the forecast area during the evening. Lower
levels of the forecast soundings are rather dry though except for
a brief window late afternoon and early evening, so will maintain
PoP`s only in the 30 percent range.
LONG TERM...Tuesday through Friday:
Upper troughing begins to dig across California Tuesday night as a
closed low moves southeast toward Los Angeles. As the week
progresses, the question becomes how deep this remains and how
fast the remaining closed low is ejected northeast. GFS and ECMWF
maintain a rather wide range as a storm system develops over the
Plains. The GFS remains much further south, with more of an
inverted trough extending over southeast Illinois by Thursday
morning. The ECMWF loiters a warm front just north of I-72 most of
Wednesday and Thursday, before the parent low arrives Thursday
evening. Both solutions would favor widespread showers, although
the warmer ECMWF would suggest thunder being more widespread. Have
not changed too much from the previous forecast, which favored the
ECMWF and warmer temperatures.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
657 AM CDT SAT MAR 29 2014
.DISCUSSION...
302 AM CDT
TODAY...
THIS MORNING...RIDGE OF HIGH PRESSURE EXTENDS FROM LAKE SUPERIOR
INTO THE MID MISSOURI VALLEY WHILE LOW PRESSURE LIES OVER
MISSISSIPPI/ALABAMA. THIS LOW WILL LIFT NORTH INTO THE UPPER OHIO
VALLEY TODAY RESULTING IN NORTHEASTERLY WINDS OFF OF LAKE MICHIGAN
THROUGH THE DAY. SOME PRECIP MAY BRUSH THE FAR SOUTHEASTERN COUNTIES
THIS MORNING...MAINLY IN THE FORM OF SNOW...THOUGH ANY ACCUMULATION
WILL LIKELY BE CONFINED TO GRASSY AREAS AND ONLY A DUSTING IS
EXPECTED. SPLIT CHANNEL IR IMAGERY SHOWS STRATUS STILL SPANS MUCH OF
THE UPPER MIDWEST...AS FAR WEST AS CENTRAL IOWA AND NORTHWEST INTO
CENTRAL WISCONSIN. EXPECT CLOUD COVER TO LINGER THROUGH AT LEAST
MIDDAY...THEN ANTICYCLONIC FLOW WITH THE RIDGE AXIS SHOULD START TO
BUILD IN FROM THE NORTHWEST THIS AFTERNOON AND EVENING WITH SKIES
CLEARING. TEMPERATURES TODAY ARE EXPECTED TO WARM INTO THE LOW TO
MID 40S...THOUGH WILL STAY IN THE 30S NEAR THE LAKE WITH THE
OFFSHORE FLOW THROUGH THE DAY.
SUNDAY AND MONDAY...
COMPACT UPPER WAVE WILL MOVE ONSHORE OVER SOCAL EARLY SUNDAY...THEN
TRANSLATE EAST ACROSS THE CENTRAL PLAINS BY MONDAY. SURFACE LOW WILL
DEEPEN IN RESPONSE OVER THE CENTRAL PLAINS THROUGH THE PERIOD WITH
STRONG WARM ADVECTION INTO THE REGION HELPING TO AMPLIFY THE
MID/UPPER LEVEL RIDGING. H85 TEMPS WILL WARM TO AROUND 10C BY SUNDAY
EVENING...AND 12C TO 13C BY MONDAY. CLIMO FROM NARR DATASET SHOWS
MEDIAN TEMPS IN THE LOW 70S WHEN H85 TEMPS EXCEED AROUND 9C FOR THE
LATTER HALF OF MARCH. WHILE THESE WARMER TEMPERATURES ALOFT WILL
ARRIVE LATER IN THE DAY SUNDAY...THEY SHOULD BE DIRECTLY OVERHEAD ON
MONDAY WHICH IS EXPECTED TO BE THE WARMEST DAY IN SOME TIME. BACKED
OFF SLIGHTLY ON TEMPS FOR SUNDAY...AND WHILE I THINK AREAS
ESPECIALLY IN THE WESTERN CWA STILL HAVE A GOOD CHANCE OF 60...IT
MAY STRUGGLE TO REACH 60 IN CHICAGO AND EASTERN PORTIONS OF THE CWA
DUE TO THE SLOWER ARRIVAL. THE MAIN CONCERNS FOR TEMPS MONDAY REVOLVE
AROUND CONVECTIVE CHANCES AND CLOUD COVER WHICH WILL INHIBIT HOW
WARM WE GET. H5 VORT TAKES ON A NEGATIVE TILT MONDAY AS IT LIFTS
ACROSS THE MID-MISSOURI VALLEY AND LEFT EXIT REGION OF UPPER JET
OVER THE AREA WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. LATEST
THINKING ON TIMING OF THE LOW STILL HAS THE BETTER FORCING WELL TO
THE WEST DURING PEAK HEATING WHEN SOME VERY MODEST SURFACE BASED
INSTABILITY EXISTS. WITH THUNDERSTORMS DEVELOPING TO THE
WEST...COULD SEE CIRRUS STREAMING OVERHEAD DURING THE DAY MONDAY
WHICH WILL IMPACT TEMPS. WITH A PRETTY DYNAMIC SYSTEM...MAY BE ABLE
TO OVERCOME THE LACK OF FAVORABLE THERMODYNAMICS FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP...PARTICULARLY IN THE LATER
AFTERNOON AND EVENING. REFINED POPS TO REFLECT THESE TIMING DETAILS
BUT MAINTAINED 20 TO 30 PERCENT DUE TO COVERAGE CONCERNS. AS FAR AS
TEMPS...REMAIN ON THE WARM SIDE OF THE SOLUTION ENVELOPE BUT WILL
HOLD OFF ON GOING ABOVE GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND
UNCERTAINTY IN PRECIP. WINDS WILL BECOME PROGRESSIVELY BREEZY
THROUGH THIS PERIOD...WITH GUSTS TO AROUND 20 MPH POSSIBLE ON SUNDAY
AND EVEN BREEZIER CONDITIONS ON MONDAY. 50KT WINDS ARE NOTED AROUND
900MB MONDAY...AND WITH DEEP MIXING POSSIBLE...THE AREA MAY SEE
30MPH+ GUSTS AT THE SURFACE DURING THE AFTERNOON.
TUESDAY THROUGH FRIDAY...
AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THE UPCOMING WORK WEEK AS A SERIES OF WAVES PROGRESS ACROSS THE
REGION. STILL CONSIDERABLE TIMING/TRACK DIFFERENCES THOUGH GUIDANCE
DOES SEEM TO BE FAVORING A MORE SOUTHERLY/COOLER PATTERN...
ESPECIALLY THE GFS WITH GOOD SUPPORT FROM THE GEFS. THE EMCWF
MAINTAINS A WARMER SOLUTION...WITH BAROCLINIC ZONE VERY NEAR
RESULTING IN A DECENT TEMPS SPREAD NORTH TO SOUTH ACROSS THE CWA.
CONTINUE TO RUN WITH A MODEL CONSENSUS BLEND FOR TEMPS NEXT WEEK
GIVEN THE HIGH DEGREE OF UNCERTAINTY...WHICH RESULTS IN WELL BELOW
NORMAL TEMPS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* NORTHEAST WINDS FOR MOST OF THE DAY.
* MVFR CEILINGS THIS MORNING BUT SCATTERING TO VFR THIS AFTERNOON.
LENNING
//DISCUSSION...UPDATED 12Z...
HIGH PRESSURE MOVING TOWARD THE AREA WILL SUPPORT GRADUALLY
CLEARING SKIES. WINDS REMAIN NORTH TO NORTHEAST FOR MOST OF THE
DAY AHEAD OF THE RIDGE...THEN TURN EAST TOMORROW BEHIND IT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM CONFIDENCE IN TIMING OF VFR CEILINGS.
* HIGH FOR OTHER ELEMENTS
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF TSRA. GUSTY SOUTH WINDS.
TUESDAY...SLGT CHC OF RAIN DURING THE NIGHT.
WEDNESDAY...RAIN AND MVFR LIKELY.
THURSDAY AND FRIDAY...SLGT CHC OF RAIN AND SNOW.
LENNING
&&
.MARINE...
310 AM CDT
WINDS GENERALLY WILL REMAIN NORTHERLY OR NORTHEASTERLY TODAY AHEAD
OF AN APPROACHING HIGH PRESSURE RIDGE...THEN WILL VEER EAST AFTER
THE RIDGE PASSES EARLY SUNDAY. THE EAST OR SOUTHEAST FLOW THEN
PERSISTS THROUGH THE WEEKEND INTO EARLY NEXT WEEK. STRONG LOW
PRESSURE MOVES THROUGH THE NORTHERN PART OF THE LAKE MONDAY
NIGHT...LIKELY SUPPORTING A PERIOD OF GALES ON THE SOUTHERN HALF.
THE WARM SOUTHERLY FLOW AHEAD OF THE LOW MONDAY AFTERNOON WILL BE
VERY STRONG BUT MAY BE LESS EFFECTIVE AT CREATING GALES THAN THE
WEAKER BUT COLDER WINDS BEHIND THE LOW ON MONDAY NIGHT AND
TUESDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
640 AM CDT Sat Mar 29 2014
.DISCUSSION...
ISSUED 227 AM CDT Sat Mar 29 2014
Surface low tracking across northern Mississippi early this
morning, while an upper trough moves through Iowa and western
Missouri. Area of showers streaming northward ahead of the upper
trough has made it up to around Taylorville and Sullivan as of 2
am, although the leading edge has had to fight some dry air to
make it that far.
A rather active weather pattern is on tap for next week, with
precipitation timing the primary forecast concern.
SHORT TERM...Today through Monday:
Will maintain some precipitation chances across the far eastern
CWA for the first few hours after sunrise, until the trough moves
into Illinois. Forecast soundings off the RAP model suggest some
rain/snow mix north of I-70 until the ice crystals are lost by mid
morning, with rain to the south. Otherwise, will see a decrease in
clouds from west to east this afternoon, as ridge axis moves
southeast out of the northern Plains.
Decent warm air advection sets up early Sunday as the high drifts
east of the state. With abundant sunshine, have sided more toward
the MAV MOS highs in the lower to mid 60s, with temperatures in
the mid to upper 60s on Monday. Monday looks to be fairly windy
ahead of the next storm system, with Bufkit data suggesting wind
gusts of 30-40 mph. Main surface low expected to track northeast
into southern Minnesota by late afternoon, with the trailing cold
front sweeping through the forecast area during the evening. Lower
levels of the forecast soundings are rather dry though except for
a brief window late afternoon and early evening, so will maintain
PoP`s only in the 30 percent range.
LONG TERM...Tuesday through Friday:
Upper troughing begins to dig across California Tuesday night as a
closed low moves southeast toward Los Angeles. As the week
progresses, the question becomes how deep this remains and how
fast the remaining closed low is ejected northeast. GFS and ECMWF
maintain a rather wide range as a storm system develops over the
Plains. The GFS remains much further south, with more of an
inverted trough extending over southeast Illinois by Thursday
morning. The ECMWF loiters a warm front just north of I-72 most of
Wednesday and Thursday, before the parent low arrives Thursday
evening. Both solutions would favor widespread showers, although
the warmer ECMWF would suggest thunder being more widespread. Have
not changed too much from the previous forecast, which favored the
ECMWF and warmer temperatures.
Geelhart
&&
.AVIATION...
ISSUED 640 AM CDT Sat Mar 29 2014
MVFR cigs will continue at all TAF sites until sometime after 18z.
Vis is lower at some sites, so have a TEMPO group for PIA/DEC/CMI
and a TEMPO group for SPI with cigs below 1kft for a couple hours
this morning. Clouds will hopefully scatter out this afternoon as
models show some drier air advecting into the region; PIA and SPI
first, followed by CMI last. Skies will eventually become clear,
but not until the early evening time frame, right around sunset.
Clear skies will then continue til tomorrow mroning. Winds will be
northerly through the day, and then become light and variable
tonight. Wind speeds this morning will be around 10kts, but then
as the clouds scatter out, some mixing will occur and think that
all sites could see gusts to around 20kts. Light winds expected
tonight.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1035 AM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 1022 AM EDT SAT MAR 29 2014
A LOW PRESSURE SYSTEM WILL BE PASSING THROUGH THE SOUTHEASTERN
UNITED STATES TODAY AND THE CENTER WILL MOVE TO THE WASHINGTON
D.C. AREA BY TOMORROW MORNING. THIS SYSTEM WILL PASS SOME
PRECIPITATION THROUGH THE REGION TODAY IN THE FORM OF RAIN IN THE
FAR SOUTH...MIX OF RAIN AND SNOW IN THE CENTRAL AREAS...AND MAINLY
SNOW IN THE NORTH. AREAS IN THE CENTRAL TO NORTHERN PART OF THE
REGION COULD SEE THE PRECIPITATION START OUT AS RAIN THEN SWITCH
TO A MIX BEFORE FINALLY ALL SNOW. SNOWFALL AMOUNTS ARE EXPECTED TO
BE SMALL. HIGH TEMPERATURES TODAY WILL RANGE FROM THE UPPER 30S IN
THE SOUTHEASTERN HALF OF THE REGION TO THE LOWER 40S IN THE
NORTHWESTERN HALF. TONIGHT WILL BE DRY ACROSS THE REGION WITH
CLEARING SKIES AND TEMPERATURES DROPPING IN TO THE 20S.
&&
.UPDATE...
ISSUED AT 926 AM EDT SAT MAR 29 2014
ZONES/GRIDS UPDATED TO EXPAND PRECIP AS FAR NW AS SOUTH BEND AND
ADJUST TRENDS IN SE AREAS.
IMPRESSIVE LIFT UNDERWAY ACROSS PORTIONS OF THE AREA WITH NARROW
BAND OF HIGHER RETURNS SHOWING UP...RESULTING IN MAINLY SNOW AT
THE SFC. BAND INITIALLY STARTED FROM ROUGHLY GRISSOM ARB TO WARSAW
AND HAS BEEN SHIFTING SLOWLY EAST WITH TIME. EASTWARD EXTENT OF
THE BAND AND NORTHERN EXTENT OF PRECIP SHIELD MOVING IN FROM
CENTRAL INDIANA WAS BEING HAMPERED BY JUST ENOUGH SUBSIDENCE AND
THE DRY NE FLOW. RUC DID AN AWESOME JOB OF CAPTURING THIS
SETUP...WHICH MAKES THE FORECAST INTO THE AFTERNOON THAT MUCH MORE
TROUBLESOME. 11Z RUC TAKES THE CURRENT BAND AND SLOWLY DISSIPATES
IT AS IT PROGRESSES EAST AND THE MAIN AREA ACROSS CENTRAL INDIANA
JUST GRAZING LIMA. HRRR MATCHES CLOSER TO WHAT WAS PREVIOUSLY
GRIDDED INTO THIS AFTERNOON. WHILE DRY AIR CURRENTLY IN PLACE
COULD GIVE SOME CREDENCE TO THIS...RADAR TRENDS SUGGEST THIS AREA
WILL SLOWLY FILL IN WITH ALL PRECIP FOCUSING IN SE AREAS INTO THIS
AFTERNOON. HAVE TRIED TO CAPTURE CURRENT AND EXPECTED TRENDS AS
BEST AS POSSIBLE...WITH STRUGGLE BETWEEN RAIN AND SNOW LIKELY TO
OCCUR MUCH OF THE DAY. ANY SNOW THAT DOES FALL SHOULD NOT CAUSE
ANY IMPACTS AS SFC TEMPS SHOULD REMAIN NEAR OR JUST ABOVE
FREEZING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM EDT SAT MAR 29 2014
NARROWING PCPN SHIELD OVR SE IL/SW IN ASSOCD W/APCH OF AMPLIFYING SW
ROLLING SEWD OUT SRN IA LOOKS TO BE MAKING A BEELINE FOR KFWA
TERMINAL BY DAYBREAK AND LINES UP EXCEEDINGLY WELL W/06Z LOCAL WRF.
THUS WILL STAND PAT W/PRIOR 06Z ISSUANCE. BRIEF PD OF IFR CONDS PSBL
TIMED W/CRUX OF SHRT DURATION MESOBAND BTWN 13-16Z ALTHOUGH PRECIP
INTENSITY STILL APPEARS TO BE OF INSUFFICIENT INTENSITY TO PROVIDE
AN ACCUMULATION ON HARD GROUND SFCS. OTRWS GENERAL MVFR CIG
RESTRICTIONS TO PERSIST UNDERNEATH FNTL INVERSION ALOFT INTO MID
AFTN BFR DEEP SUBSIDENT DRYING DVLPS IN WAKE OF DEPARTING MID LVL
TROUGH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
939 AM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 630 AM EDT SAT MAR 29 2014
LIGHT SNOW WILL BEGIN ACROSS PARTS THE AREA TOWARD SUNRISE AND
CONTINUE THROUGH THIS MORNING. THE SNOW MAY BE MIXED WITH RAIN AT
TIMES. TOTAL SNOWFALL ACCUMULATIONS UP TO AN INCH ARE EXPECTED
SOUTHEAST OF US HIGHWAY 24.
&&
.UPDATE...
ISSUED AT 926 AM EDT SAT MAR 29 2014
ZONES/GRIDS UPDATED TO EXPAND PRECIP AS FAR NW AS SOUTH BEND AND
ADJUST TRENDS IN SE AREAS.
IMPRESSIVE LIFT UNDERWAY ACROSS PORTIONS OF THE AREA WITH NARROW
BAND OF HIGHER RETURNS SHOWING UP...RESULTING IN MAINLY SNOW AT
THE SFC. BAND INITIALLY STARTED FROM ROUGHLY GRISSOM ARB TO WARSAW
AND HAS BEEN SHIFTING SLOWLY EAST WITH TIME. EASTWARD EXTENT OF
THE BAND AND NORTHERN EXTENT OF PRECIP SHIELD MOVING IN FROM
CENTRAL INDIANA WAS BEING HAMPERED BY JUST ENOUGH SUBSIDENCE AND
THE DRY NE FLOW. RUC DID AN AWESOME JOB OF CAPTURING THIS
SETUP...WHICH MAKES THE FORECAST INTO THE AFTERNOON THAT MUCH MORE
TROUBLESOME. 11Z RUC TAKES THE CURRENT BAND AND SLOWLY DISSIPATES
IT AS IT PROGRESSES EAST AND THE MAIN AREA ACROSS CENTRAL INDIANA
JUST GRAZING LIMA. HRRR MATCHES CLOSER TO WHAT WAS PREVIOUSLY
GRIDDED INTO THIS AFTERNOON. WHILE DRY AIR CURRENTLY IN PLACE
COULD GIVE SOME CREDENCE TO THIS...RADAR TRENDS SUGGEST THIS AREA
WILL SLOWLY FILL IN WITH ALL PRECIP FOCUSING IN SE AREAS INTO THIS
AFTERNOON. HAVE TRIED TO CAPTURE CURRENT AND EXPECTED TRENDS AS
BEST AS POSSIBLE...WITH STRUGGLE BETWEEN RAIN AND SNOW LIKELY TO
OCCUR MUCH OF THE DAY. ANY SNOW THAT DOES FALL SHOULD NOT CAUSE
ANY IMPACTS AS SFC TEMPS SHOULD REMAIN NEAR OR JUST ABOVE
FREEZING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM EDT SAT MAR 29 2014
NARROWING PCPN SHIELD OVR SE IL/SW IN ASSOCD W/APCH OF AMPLIFYING SW
ROLLING SEWD OUT SRN IA LOOKS TO BE MAKING A BEELINE FOR KFWA
TERMINAL BY DAYBREAK AND LINES UP EXCEEDINGLY WELL W/06Z LOCAL WRF.
THUS WILL STAND PAT W/PRIOR 06Z ISSUANCE. BRIEF PD OF IFR CONDS PSBL
TIMED W/CRUX OF SHRT DURATION MESOBAND BTWN 13-16Z ALTHOUGH PRECIP
INTENSITY STILL APPEARS TO BE OF INSUFFICIENT INTENSITY TO PROVIDE
AN ACCUMULATION ON HARD GROUND SFCS. OTRWS GENERAL MVFR CIG
RESTRICTIONS TO PERSIST UNDERNEATH FNTL INVERSION ALOFT INTO MID
AFTN BFR DEEP SUBSIDENT DRYING DVLPS IN WAKE OF DEPARTING MID LVL
TROUGH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...SKIPPER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
630 AM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 630 AM EDT SAT MAR 29 2014
LIGHT SNOW WILL BEGIN ACROSS PARTS THE AREA TOWARD SUNRISE AND
CONTINUE THROUGH THIS MORNING. THE SNOW MAY BE MIXED WITH RAIN AT
TIMES. TOTAL SNOWFALL ACCUMULATIONS UP TO AN INCH ARE EXPECTED
SOUTHEAST OF US HIGHWAY 24.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM EDT SAT MAR 29 2014
NARROWING PCPN SHIELD OVR SE IL/SW IN ASSOCD W/APCH OF AMPLIFYING SW
ROLLING SEWD OUT SRN IA LOOKS TO BE MAKING A BEELINE FOR KFWA
TERMINAL BY DAYBREAK AND LINES UP EXCEEDINGLY WELL W/06Z LOCAL WRF.
THUS WILL STAND PAT W/PRIOR 06Z ISSUANCE. BRIEF PD OF IFR CONDS PSBL
TIMED W/CRUX OF SHRT DURATION MESOBAND BTWN 13-16Z ALTHOUGH PRECIP
INTENSITY STILL APPEARS TO BE OF INSUFFICIENT INTENSITY TO PROVIDE
AN ACCUMULATION ON HARD GROUND SFCS. OTRWS GENERAL MVFR CIG
RESTRICTIONS TO PERSIST UNDERNEATH FNTL INVERSION ALOFT INTO MID
AFTN BFR DEEP SUBSIDENT DRYING DVLPS IN WAKE OF DEPARTING MID LVL
TROUGH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...SKIPPER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
645 AM CDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT SAT MAR 29 2014
AN UPPER LEVEL SHORTWAVE WITH SEVERAL EMBEDDED COMPACT VORT MAXIMA
WAS EVIDENT ON SATELLITE WV IMAGES MOVING THROUGH CENTRAL IA AND
WESTERN MO AT 07Z. AREA RADARS INDICATED A FEW WEAK ECHOES IN THE
LIFT AHEAD OF THIS FEATURE FROM SW WI ALONG THE MS RIVER TO W
CENTRAL IL. AREA OBSERVATIONS HAVE YET TO INDICATE ANY PRECIPITATION
REACHING THE GROUND FROM THESE WEAK RETURNS. AN INVERTED TROUGH AT
THE SURFACE...REACHING FROM THE CENTRAL IL INTO EAST CENTRAL
IA...WAS PROVIDING ENOUGH LOW LEVEL CONVERGENCE TO KEEP THE
WIDESPREAD STRATUS THAT NEVER LEFT THE AREA YESTERDAY IN PLACE. THE
00Z KDVN SOUNDING SHOWED AN ASSOCIATED SHALLOW LAYER OF MOISTURE
TRAPPED JUST BELOW AN INVERSION AND WEDGE OF DRY AIR ABOVE 900 MB.
UPSTREAM...A LARGE UPPER LOW WAS OFF THE BC COAST WITH A DOWNSTREAM
RIDGE AXIS MOVING THROUGH THE NORTHERN ROCKIES. AHEAD OF THIS UPPER
RIDGE...HIGH PRESSURE AT THE SURFACE REACHED FROM NEB INTO NORTHERN
MN. UNDER THIS RIDGE...SKIES WERE MAINLY CLEAR AND THE MUCH DRIER
AIRMASS FEATURED DEWPOINTS IN THE TEENS AND 20S...CONTRASTING TO THE
UPPER 20S TO LOWER 30S CURRENTLY OVER THE FORECAST AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT MAR 29 2014
MAIN CHALLENGE CENTERS ON HOW FAST CLOUDS WILL CLEAR TODAY AND THE
IMPACT ON TEMPERATURES IN THE SHORT TERM. THE ADVANCING UPSTREAM
UPPER RIDGE AND DEEPENING AND PHASING OF THE DOWNSTREAM TROUGH OVER
THE OHIO VALLEY TODAY WILL RESULT IN A DEVELOPING MORE FAVORABLE
SUBSIDENCE REGIME THAN YESTERDAY. HOWEVER...THIS APPEARS TO BE A
SLOW PROCESS...AND MAY NOT RESULT IN ANY SIGNIFICANT CLEARING UNTIL
AFTERNOON.
AT THE SURFACE...A DEEPENING LOW PRESSURE SYSTEM RIDING NORTHEAST
THROUGH KY AND TN WILL IS SHOWN KEEPING AT LEAST A WEAK CYCLONIC
CURVATURE IN THE SURFACE PRESSURE FIELD EXTENDING NORTHEAST INTO
EASTERN IA UNTIL MIDDAY. THE ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AND TRAPPED MOISTURE BELOW THE LINGERING INVERSION ALOFT...WILL KEEP
THE STRATUS HOLDING IN PLACE OVER MOST THE FORECAST AREA THIS
MORNING. THE BACK EDGE OF THE CLOUDS...CURRENTLY SLOWLY ADVANCING
E-SE ACROSS N CENTRAL AND FAR WESTERN IA WILL LIKELY COME TO A HALT
OVER CENTRAL IA INTO EASTERN IA THIS MORNING. FORECAST MODELS
CONTINUE TO STRUGGLE WITH THIS...AND AT THIS TIME ONLY THE RAP 900
MB RH FIELD SEEMS TO HAVE A GOOD HANDLE ON THIS TREND. WILL THUS KEEP
MOSTLY CLOUDY SKIES GOING THROUGH THE MORNING...THEN TRANSITION TO
MOSTLY SUNNY BY AFTERNOON AS THE SURFACE AND UPPER LEVEL RIDGE MOVE
OVERHEAD BRINGING SUBSIDENCE AND DRIER AIR. ACCOUNTING FOR THIS
DELAYED WARMING...AND WEAK MIXING UNDER THE RIDGE...HAVE HELD HIGH
TEMPERATURES AT THE LOWER END OF GUIDANCE...FROM THE MID 40S NORTH
TO LOWER 50S SOUTH.
TONIGHT...SKIES WILL START OUT CLEAR WITH ADVANCING HIGH CLOUDS
FOLLOWING PASSAGE OF THE UPPER RIDGE AXIS TOWARD MORNING. AT THE SURFACE...
INITIALLY LIGHT WINDS WILL TURN SOUTHERLY AND INCREASE TO AT LEAST 5
TO 10 KTS TOWARD MORNING AS A TROUGH MOVES INTO THE PLAINS. THIS
WOULD SUPPORT AN INITIAL COOL-DOWN AFTER SUNSET...THEN STEADY TO
POSSIBLY EVEN RISING TEMPERATURES TOWARD SUNRISE. WITH MOST MODELS
OVERALL TRENDING TOO MOIST IN THE LOWER LEVELS...HAVE GONE CLOSER TO
THE BETTER INITIALIZING ECMWF WITH ITS LOWER DEWPOINTS IN THE 20S
BEFORE THE RETURN FLOW SETS UP. THIS POINTS TOWARD LOWER MINS THAN
MOS...AND HAVE GONE WITH LOWS FROM THE MID 20S EAST TO LOWER 30S IN
THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT MAR 29 2014
MILD WITH A FAST MOVING DISTURBANCE MONDAY...THEN FAVORABLE SETUP
FOR SIGNIFICANT TO HEAVY PRECIPITATION MID TO LATE NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION AVERAGE WITH STILL QUESTIONS
ON PHASING OF PACIFIC ENERGY ARRIVING NEXT FEW DAYS. AGAIN POOR BL
ISSUES THAT ARE OFF BY 3-5 DEGREES FOR BOTH T AND T/D THAT MOS OR
OTHER ALGORITHMS ARE HAVING PROBLEMS HANDLING. TREND IS FOR A DEEPER
TROUGH INTO THE PACIFIC SW BY TUESDAY WHICH IS A GOOD REGIME FOR
MODERATE TO HEAVY PRECIPITATION...MOSTLY RAIN WITH STALLED FRONT
TO OUR SOUTH FOR PROLONGED UPGLIDE. VARIANCES CONTINUE WITH HI-RES ECMWF
BY FAR THE FURTHEST NORTH. RUN TO RUN TRENDS AND VARIANCES SUPPORTS
A MIX OF THE UKMET/GFS /GEM-NH AND TO DISREGARD THE HI-RES ECMWF.
TRENDS ARE FOR NORTH PORTIONS TO SEE AT LEAST A FEW PERIODS OF A
MIX OF RAIN AND WET SNOW WHICH WILL TAKE ANOTHER 24 HOURS TO BETTER
ASCERTAIN. THIS 2 TO 3 DAY EVENT WEDNESDAY INTO FRIDAY WILL BE THE
HEAVIEST PRECIPITATION EVENT...WIDESPREAD 1 TO 2 PLUS INCH AMOUNTS
SINCE LAST FALL. CONDITIONS OF THIS TYPE CONTINUE TO SUGGEST WILL
HELP REPLENISH THE MODESTLY DRY SOILS AND PREPARE THE GROUND FOR
SPRING.
SUNDAY...EXPECT MODERATE BL MIXING AND MODERATE SOUTHERLY WINDS OF UP
TO 15 TO 25+ PH IN THE AFTERNOON. TRENDS STILL SUPPORT HIGHS IN LOWER
TO MIDDLE 60S WITH AFTERNOON RH VALUES FALLING BELOW 50 PERCENT TO
LOCALLY NEAR 40 PERCENT. THIS INDICATES GFDI VALUES INTO VERY HIGH
CATEGORY FOR SEVERAL HOURS IN THE AFTERNOON...MAINLY WEST OF THE
MISSISSIPPI RIVER DUE TO LITTLE TO NO GREENING OF VEGETATION. THIS
WILL REMAIN IN THE HWO PRODUCT. SUNDAY NIGHT...SOUTH WINDS OF 10 TO
20 MPH TO MAKE FOR THE MILDEST NIGHT IN MANY MONTHS DESPITE FAIR SKIES
WITH LOWS IN THE MID TO UPPER 40S....TO AROUND 50F SOUTH.
MONDAY...NEXT VIGOROUS AND FAST MOVING STORM SYSTEM SIMILAR TO YESTERDAY/S.
IS SLIGHTLY SLOWER...KEEPING MID CHANCE POPS WITH SHOWERS AND ISOLATED
MAINLY PM STORMS. WINDS WILL BE STRONGER ALLOWING FOR LOWER PM DEWPOINTS.
MID LEVEL SHOWERS AND ISOLATED STORMS WITH BASES AOA 6K AGL. LOW FREEZING
LEVEL STILL SUGGESTS NON-SEVERE STORMS WITH SOME PEA HAIL POSSIBLE AS
ANY STORMS WOULD FIRE OVER CWA IN MID/LATE PM HOURS. RAISED HIGHS BY
2-3 DEGREES INTO THE MID/UPPER 60S. WINDS MID DAY SHOULD BECOME QUITE
WINDY APPROACHING WIND ADVISORY CRITERIA OF 20 TO 30 MPH WITH GUSTS
TO AROUND 40 MPH. RH VALUES SHOULD FALL TO AROUND 50 PERCENT THAT MAY
SUPPORT NEAR VERY HIGH CONDITIONS FOR FIRE WEATHER BUT SHOWERS/STORMS
SHOULD AMELIORATE A BIT ALONG WITH HIGHER RH VALUES. MONDAY NIGHT...SLIGHTLY
DELAYED TIMING OF COOL FRONTAL PASSAGE INTO MID/LATE EVENING AND GUSTY
NW WINDS TO LIMIT COOLING BY MORNING. THIS SUGGESTS MINS NEAR GUIDANCE
BLEND...OR UPPER 20S FAR NW TO MIDDLE 30S FAR SE SECTIONS.
TUESDAY...LITTLE CHANGE TO CURRENT FORECAST. COOLER AND MOSTLY FAIR
SKIES WITH HIGHS MOSTLY OF 45 TO 50 DEGREES AND LIGHT NE WINDS AHEAD
OF NEXT...LARGE...SLOW MOVING AND QUITE STRONG UPPER DISTURBANCE AND
DEEP TROUGH MOVING EAST FROM CALIFORNIA. TUESDAY NIGHT...INCREASING
CLOUDS STILL SUGGEST LOWS TO OCCUR NEAR OR BEFORE MIDNIGHT....THEN
RISING TOWARD MORNING WITH CLOUDS RAIN AND INCREASING EAST WINDS.
LOCATIONS NORTH OF I-80 MAY SEE WITH EVAPORATIVE COOLING A MIX OF
SNOW BY MORNING...OR JUST A WET SNOW. THIS REMAINS A POOR CONFIDENCE
ON MIXED PRECIPITATION NORTH SECTIONS. THIS QUESTION SHOULD BE
RESOLVED NEXT 12-24 HOURS. LOCAL TOOLS DO SUPPORT SOME ACCUMULATIONS
MAY OCCUR ON EXPOSED SURFACES ATTM BUT AREA TEMPERATURES AT OR
SLIGHTLY ABOVE FREEZING TO LIMIT IMPACTS ON ROADWAYS.
WEDNESDAY THROUGH FRIDAY...PROLONGED PERIODS OF CLOUDY...COLD AND EPISODES
OF RAIN OR MOSTLY RAIN WITH A RISK OF A MIX NORTH SECTIONS OR EVEN
A WET SNOW BY FRIDAY AS SYSTEM MOVES EAST. HIGHS MOSTLY IN THE 40S
WITH LOWS IN THE 30S. REVIEW OF LOCAL FORECAST AREA TOOLS INDICATE
1 TO LOCALLY NEAR 2 INCHES OF RAIN OR MOSTLY RAIN OVER THIS PERIOD
REMAINS ON TRACK. THIS SYSTEM IS SLOWING DOWN WHICH MAY ALLOW FOR
EVEN MORE MOISTURE AND MAY RESULT IN EVEN SLIGHTLY HEAVIER AMOUNTS
OF RAIN AND EVEN A WET SNOW AS OPEN GULF MOISTURE HAS MORE TIME TO
POOL AHEAD OF THE FRONT. THIS SYSTEM BEARS CLOSE WATCHING DUE TO
ITS STRENGTH...CURRENT TRACK TO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 645 AM CDT SAT MAR 29 2014
LOW CLOUDS COVERING EASTERN IOWA AND NORTHWEST ILLINOIS EARLY THIS
MORNING WILL GRADUALLY DISSIPATE AND PUSH EASTWARD TODAY AS HIGH
PRESSURE MOVES INTO THE REGION. THERE REMAINS CONSIDERABLE
UNCERTAINTY IN THE TIMING OF THIS CLEARING. TEMPO GROUPS WERE
UTILIZED IN THE TAFS TO DEMONSTRATE THIS UNCERTAIN LATE MORNING
TRANSITION FROM MVFR TO VFR CONDITIONS AT DBQ...MLI AND BRL. HIGH
PRESSURE WILL THEN PROVIDE LIGHT WINDS AND VFR CONDITIONS
OVERNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...NICHOLS
AVIATION...SHEETS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
634 AM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAR 29 2014
A WARM DRY SURGE IS READY TO GO TODAY. THE SOURCE REGION FOR THIS
WARM AIR IS THE SOUTH CENTRAL ROCKIES AND THE RAP MODEL SHOWS
SOUTHWEST WINDS DRAWING THIS AIR THROUGH THE FCST AREA...GENERALLY
ALONG AND WEST OF HIGHWAY 83.
NEARLY FULL SUN IS EXPECTED AS THE NEAREST CIRRUS IS OVER THE TETONS
AND BIG HORNS. THE GFS HOWEVER SHOWS CIRRUS DEVELOPING THIS AFTN OFF
THE LARAMIE RANGE AND THIS IS SUPPORTED BY THE ECM WHICH GENERALLY
HAS GOOD SKILL WITH HIGH CLOUDS. STILL...THE SUPER ENSEMBLE
TEMPERATURE FORECAST PRODUCES HIGHS IN THE UPPER 60S TO NEAR 70
WHICH WERE MARKED UP TO LOWER 70S IN MANY AREAS GIVEN THE VERY DEEP
MIXING SHOWN BY THE RAP MODEL.
SOUTHWEST WINDS INCREASE TO 15 TO 25 MPH AND A BLEND OF THE
NAM...RAP AND GFS WIND GUST PRODUCTS PRODUCED WIND GUSTS TO 35 MPH.
FOR TONIGHT...THE THERMAL RIDGE FORECAST TO MOVE OFF THE ROCKIES
TODAY CONTINUES TO BUILD ACROSS THE FORECAST AREA. LOWS SHOULD ONLY
FALL TO THE MID 30S TO LOWER 40S WITH DECOUPLING POSSIBLE OVER
SOUTHWEST NEB FOR LOCALLY COOLER LOWS GIVEN THE VERY DRY
ENVIRONMENTAL CONDITIONS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAR 29 2014
UPPER LEVEL RIDGE TO BREAK DOWN ON SUNDAY AS AN UPPER TROUGH
ADVANCES NORTHEAST FROM THE GREAT BASIN TOWARD THE CENTRAL PLAINS.
WITH THE APPROACH OF THE UPPER TROUGH...CYCLOGENESIS WILL COMMENCE
OFF THE LEE OF THE ROCKIES WITH SUBSEQUENT DEEPENING OF THE
SURFACE LOW THROUGH THE DAY. THE LOW SHOULD REMAIN FOCUSED ALONG
OR NEAR THE CHEYENNE RIDGE SUNDAY...WHICH AS IT DEEPENS WILL ALLOW
FOR BACKED SURFACE WINDS TO THE SOUTHEAST. DESPITE HIGH
TEMPERATURES WELL INTO THE 70S ACROSS THE CENTRAL SANDHILLS AND
POINTS SOUTH /MAYBE A FEW 80S AS WELL/...THIS BACKED SURFACE FLOW
WILL ALLOW FOR A GREATER MOISTURE TRAJECTORY OFF THE GULF...RATHER
THAN THE DIRECT DOWNSLOPE FLOW FROM SOUTH CENTRAL COLORADO. TD/S
ARE ANTICIPATED TO RISE SOME...BUT STEEP LOW-MID LEVEL LAPSE RATES
WILL CONTINUE TO MIX DRY ALOFT TO THE SURFACE...EFFECTIVELY
KEEPING MINIMUM RELATIVE HUMIDITIES NEAR CRITICAL THRESHOLDS.
ATTM...SOUTHWEST NEBRASKA AND THE CENTRAL SANDHILLS ARE EXPECTED
TO SEE RH IN THE 15 PERCENT RANGE BY EARLY AFTERNOON...BUT SHOULD
INCREASE SLIGHTLY TOWARD EVENING. EXTENDING FROM THE LOW WILL BE
AN INVERTED SURFACE TROUGH...WHICH WOULD PRODUCE A WEAKNESS IN THE
WIND FIELD. AVAILABLE MODEL GUIDANCE DOES NOT SUPPORT RFW WIND
CRITERIA ATTM ACROSS THE CENTRAL SANDHILLS. HOWEVER STRONG MIXING
DUE TO VERY STEEP LOW-MID LEVEL LAPSE RATES WOULD ALLOW FOR
DOWNWARD MOMENTUM TRANSFER. GUSTS IN EXCESS OF 25 MPH ARE
INDICATED BY BUFR SOUNDINGS WHERE THE RH MINIMUM EXISTS /SOUTHWEST
NEBRASKA. AN ADDITIONAL RED FLAG WARNING IS ANTICIPATED FOR
SUNDAY. FOR THIS WILL ISSUE A FIRE WEATHER WATCH WHERE CONFIDENCE
IS HIGH /FIRE ZONES 210 AND 219/ ON SEEING RFW CRITERIA. STEEP
LAPSE RATES ASSOCIATED WITH AN EASTWARD ADVECTING EML WILL
OVERSPREAD MUCH OF THE CENTRAL HIGH PLAINS LATE AFTERNOON/EARLY
EVENING RESULTING IN WEAK INSTABILITY ALOFT. HIGH BASED CONVECTION
IS POSSIBLE...IF STORMS FIRE...SURFACE TD/T SPREADS OF 40 DEGREES
OR WOULD SUGGEST THE POTENTIAL FOR STRONG TSTM OUTFLOW WITH LITTLE
RAINFALL. NOT ANTICIPATING A LAL OF 6...BUT TROUBLESOME
NONETHELESS. ADDITIONAL CONVECTION IS POSSIBLE INTO THE EVENING
HOURS AS THE TROUGH AND ASSOCIATE COLD FRONT CROSS THE CENTRAL
PLAINS...BUT ONCE AGAIN MOISTURE INITIALLY IS LACKING...SO WETTING
RAINS WILL BE ISOLATED AT BEST. BEYOND SUNDAY EVENING THE FORECAST
GETS TRICKY...ESPECIALLY WHEN CONSIDERING THE POTENTIAL IMPACTS OF
THE IMPENDING LATE WINTER STORM. ATTM...THERE/S SUFFICIENT
AGREEMENT IN THE MODELS TO SUGGEST RAIN CHANGING OVER TO SNOW
EARLY ON MONDAY ACROSS OUR NORTHERN ZONES AS THE MAIN TROUGH DRAGS
MODIFIED ARCTIC AIR SOUTH INTO THE CWA. IN TERMS OF
IMPACTS...TEMPERATURES AT LEAST INITIALLY WILL REMAIN IN THE LOWER
30S...AND GIVEN THE WARM WEEKEND...SNOW MAY STRUGGLE TO ACCUMULATE
ON PAVED SURFACES...ESPECIALLY TRUE IF THE BRUNT OF THE SNOW
OCCURS AFTER SUNRISE. BUT...WINDS ON THE BACKSIDE OF THE EJECTING
SFC LOW WILL BE EXTREMELY GUSTY...WITH THE POTENTIAL OF 35 MPH
GUSTS /OR HIGHER/ ACROSS NORTH CENTRAL NEBRASKA ON MONDAY.
VISIBILITY WILL BE SIGNIFICANTLY REDUCED WHEN SNOW IS FALLING.
WINTER HEADLINES ARE POSSIBLE ON MONDAY ACROSS NORTHERN
NEBRASKA...WITH THE GREATEST IMPACTS FOCUSED ALONG AND NORTH OF
THE HIGHWAY 20 CORRIDOR. WILL INCREASE POPS IN THIS AREA INTO THE
LOW LIKELY RANGE WITH THIS FORECAST ISSUANCE. BEYOND MONDAY...THE
PATTERN REMAINS ACTIVE THROUGHOUT THE ENTIRE NEXT WORK WEEK AS
QUASI-ZONAL FLOW SLOWLY TRANSITIONS TO SOUTHWESTERLY WITH THE
APPROACH OF THE NEXT LONGWAVE WESTERN CONUS TROUGH. THIS PATTERN
FAVORS SEASONAL...TO SLIGHTLY BELOW AVERAGE TEMPERATURES THROUGH
AT LEAST NEXT THURSDAY. IN ADDITION...AS THE NEXT UPPER TROUGH
DIGS ACROSS THE GREAT BASIN MID-WEEK...A COLD FRONT WILL REMAIN
FIXED SOUTH OF THE CWA...WHICH WILL GENERALLY PROVIDE FOR UPSLOPE
FLOW AND CONSIDERABLE CLOUDINESS EACH DAY. PRECIPITATION WILL
REMAIN IN THE FORECAST AS WELL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 634 AM CDT SAT MAR 29 2014
PATCHY/AREAS OF FOG AND IFR/LIFR ACROSS NCNTL NEB WILL DISPERSE BY
15Z. VFR IS EXPECTED ALL AREAS THEREAFTER THROUGH 12Z SUNDAY.
SCATTERED HIGH CLOUDS WILL SPREAD EAST OFF THE CNTL ROCKIES AHEAD
OF A DISTURBANCE MOVES THROUGH THE WRN U.S.
&&
.FIRE WEATHER...
ISSUED AT 354 AM CDT SAT MAR 29 2014
THE RAP AND HRRR MODELS SHOW DEWPOINTS FALLING INTO THE TEENS TODAY.
THE MODEL CONSENSUS SHOWS SOUTHWEST WINDS INCREASING TO 15 TO 25 MPH
THIS AFTERNOON. A BLEND OF THE NAM...RAP AND GFS WIND GUST PRODUCTS
PRODUCED GUSTS TO 35 MPH THIS AFTERNOON ALSO.
THE SOURCE REGION FOR THIS DRY AIR IS THE SCNTL ROCKIES WHERE DEW
POINTS ARE CURRENTLY IN THE SINGLE DIGITS. THE MODELS PRODUCE
SOUTHWEST WINDS OFF THE ROCKIES TODAY WHICH WILL CARRY THIS DRY AIR
INTO THE FCST AREA WHILE TEMPERATURES RISE INTO THE LOWER 70S FOR RH
VALUES FALLING INTO THE SINGLE DIGITS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING FROM 1 PM CDT /NOON MDT/ THIS AFTERNOON TO 9 PM
CDT /8 PM MDT/ THIS EVENING FOR NEZ204-206-209-210-219.
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR NEZ210-219.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...CDC
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS RALEIGH NC
927 AM EDT SAT MAR 29 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL TRACK EAST ACROSS THE REGION THROUGH
SUNDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CAROLINAS
FROM THE WEST LATE SUNDAY THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 930 AM SATURDAY...
DUE TO IMPROVED VISIBILITIES...HAVE CANCELLED THE DENSE FOG
ADVISORY IN MOST AREAS EXCEPT FOR THE NORTHERN PIEDMONT /I-85
CORRIDOR FROM CHAPEL HILL TO HENDERSON/ WHERE PATCHY DENSE FOG
WILL PERSIST THROUGH ~10 AM. -VINCENT
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME THREAT
LATE TODAY. EXTENT/SEVERITY WILL LIKELY BE LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS UNTIL AFTER
THE PEAK INSTABILITY.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE.
FOR SUNDAY: EXPECT MOSTLY CLOUDY SKIES TO HOLD PARTICULARLY OVER THE
NRN CWA AS THE LOW ALOFT SHIFTS OVER THE REGION. THE DEEPENING
SURFACE LOW JUST TO OUR NE WILL GENERATE A TIGHT MSLP GRADIENT
ACROSS NC... AND EXPECT WINDS TO BE SUSTAINED FROM THE WNW OR NW AT
15-20 MPH (HIGHEST IN THE WEST WHERE SUBSIDENCE WILL BE STRONGEST
WITHIN 100-120 M HEIGHT RISES... AND LOWER NE WHERE MIXING HEIGHTS
WILL BE LOWER)... WITH GUSTS OF 20-30 MPH... BELOW WIND ADVISORY
CRITERIA BUT THIS RISK WILL STILL NEED TO BE WATCHED. THE LOW LEVELS
DO DRY OUT WITH DOWNSLOPE FLOW BUT THIS RELATIVELY DRY LAYER WILL BE
SHALLOW... AND WE MAY STILL SEE SOME ISOLATED PATCHY LIGHT RAIN OVER
THE NRN CWA IN THE MORNING INTO EARLY AFTERNOON. WITH PLENTIFUL
CLOUDINESS... BRISK NW WINDS... COLD AIR ADVECTION... AND LOW LEVEL
THICKNESSES EXPECTED TO BE AROUND 30 M BELOW NORMAL... EXPECT CHILLY
HIGHS FROM THE UPPER 50S TO LOWER 60S... A SLIGHT DOWNWARD BUMP FROM
EARLIER FORECAST HIGHS. -GIH
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...
AS THE UPPER LOW OVER THE DELMARVA LATE SUNDAY DEPARTS OFF TO THE
NORTHEAST...CLOUD COVER ASSOCIATED WITH ITS COMMA HEAD WRAP AROUND
MOISTURE WILL DIMINISH BY MIDNIGHT. CLEARING SKIES AND SLOWLY
WEAKENING WINDS WILL ALLOW TEMPS TO DIP INTO THE 30S. BASED ON SOME
GUIDANCE...ITS POSSIBLE THAT SOME AREAS OVER THE WESTERN PIEDMONT
WILL APPROACH FREEZING BY MONDAY MORNING. RIGHT NOW IT APPEARS A
LIGHT WIND AND DRYING WILL PREVENT WIDESPREAD FROST.
THE SHOT OF COLDER AIR LOOKS TO BE VERY BRIEF AS A SHORTWAVE RIDGE
AND SURFACE HIGH PRESSURE BUILD OVER THE REGION...AND BEGIN AN
EVOLUTION INTO A PERSISTENT RIDGE OVER THE SOUTHEAST US. WITH A
LIGHT NORTHWEST WIND AND NEUTRAL THERMAL ADVECTION...LOW LEVEL
THICKNESSES AROUND 1320M MONDAY MORNING SUPPORT MET MOS GUIDANCE
MORE SO THAN THE MAV MOS...UPPER 60S NORTHEAST TO AROUND 70
SOUTHWEST. LOWS MONDAY NIGHT 39-44.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...
A RIDGE WILL DEVELOP OVER THE SOUTHEAST BY TUESDAY IS IS FORECAST TO
PERSIST THROUGH MUCH OF THE WEEK. THE PRIMARY STORM TRACK WILL BE
THROUGH THE MIDWEST AND GREAT LAKES REGION...WITH A WEAK FRONT
EXPECTED TO MOVE INTO THE MID-ATLANTIC STATES LATE TUESDAY AND THEN
WASH OUT WITHOUT HAVING MUCH...IF ANY IMPACT ON CENTRAL NC. MEDIUM
RANGE MODELS SHOW THE RIDGE HOLDING STRONG UNTIL LATE IN THE
WEEK...WHEN THE RIDGE FINALLY BREAKS DOWN AND A FRONTAL ZONE PUSHES
EAST INTO CENTRAL NC FRIDAY/FRIDAY NIGHT.
THIS PATTERN SUPPORTS A MUCH WARMER PERIOD FOR CENTRAL NC...WITH
THICKNESSES AS MUCH AS 20-30M ABOVE NORMAL AND HIGHS IN THE 70S OR
EVEN 80 IN THE SOUTHEAST BY WED/THURS.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
06Z TONIGHT. SOME IMPROVEMENT FROM IFR TO MVFR IS EXPECTED AT
INT/GSO TOWARD THE END OF THE TAF VALID PERIOD AT 12Z. A DEEP MOIST
FLOW FROM THE SOUTH AND SW... AHEAD OF A STRENGTHENING STORM SYSTEM
NOW MOVING THROUGH MS AND WRN TN... WILL BRING IFR/LIFR CONDITIONS
AND PERIODS OF MOSTLY LIGHT RAIN THROUGH DAYBREAK. WE SHOULD SEE A
BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN THROUGH THE LATE MORNING
THROUGH EARLY AFTERNOON HOURS... MOST LIKELY FROM 14Z TO 19Z... BUT
CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME... WITH IFR/LIFR CONDITIONS MOST LIKELY AT INT/GSO. THEN
STARTING SOON AFTER 19Z... A LINE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC THROUGH THE LATE
AFTERNOON/EARLY EVENING HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
02Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH LATE EVENING AND INTO EARLY OVERNIGHT. WINDS WILL SHIFT TO
BE FROM THE NW WITH THE COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT
INT/GSO... BETWEEN 04Z AND 06Z AT RDU.... AND BETWEEN 07Z AND 09Z AT
RWI/FAY.
LOOKING BEYOND 12Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NCZ007>009-
024-025.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT/HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS RALEIGH NC
730 AM EDT SAT MAR 29 2014
.SYNOPSIS...A STRONG STORM SYSTEM WILL TRACK EASTWARD THROUGH THE
REGION TODAY THROUGH SUNDAY. HIGH PRESSURE WILL BUILD INTO THE AREA
SUNDAY NIGHT THROUGH TUESDAY.
&&
.NEAR TERM /TODAY THROUGH SUNDAY/...
AS OF 300 AM SATURDAY...
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME THREAT
LATE TODAY. EXTENT/SEVERITY WILL LIKELY BE LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS UNTIL AFTER
THE PEAK INSTABILITY.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE.
FOR SUNDAY: EXPECT MOSTLY CLOUDY SKIES TO HOLD PARTICULARLY OVER THE
NRN CWA AS THE LOW ALOFT SHIFTS OVER THE REGION. THE DEEPENING
SURFACE LOW JUST TO OUR NE WILL GENERATE A TIGHT MSLP GRADIENT
ACROSS NC... AND EXPECT WINDS TO BE SUSTAINED FROM THE WNW OR NW AT
15-20 MPH (HIGHEST IN THE WEST WHERE SUBSIDENCE WILL BE STRONGEST
WITHIN 100-120 M HEIGHT RISES... AND LOWER NE WHERE MIXING HEIGHTS
WILL BE LOWER)... WITH GUSTS OF 20-30 MPH... BELOW WIND ADVISORY
CRITERIA BUT THIS RISK WILL STILL NEED TO BE WATCHED. THE LOW LEVELS
DO DRY OUT WITH DOWNSLOPE FLOW BUT THIS RELATIVELY DRY LAYER WILL BE
SHALLOW... AND WE MAY STILL SEE SOME ISOLATED PATCHY LIGHT RAIN OVER
THE NRN CWA IN THE MORNING INTO EARLY AFTERNOON. WITH PLENTIFUL
CLOUDINESS... BRISK NW WINDS... COLD AIR ADVECTION... AND LOW LEVEL
THICKNESSES EXPECTED TO BE AROUND 30 M BELOW NORMAL... EXPECT CHILLY
HIGHS FROM THE UPPER 50S TO LOWER 60S... A SLIGHT DOWNWARD BUMP FROM
EARLIER FORECAST HIGHS. -GIH
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 330 AM SATURDAY...
AS THE UPPER LOW OVER THE DELMARVA LATE SUNDAY DEPARTS OFF TO THE
NORTHEAST...CLOUD COVER ASSOCIATED WITH ITS COMMA HEAD WRAP AROUND
MOISTURE WILL DIMINISH BY MIDNIGHT. CLEARING SKIES AND SLOWLY
WEAKENING WINDS WILL ALLOW TEMPS TO DIP INTO THE 30S. BASED ON SOME
GUIDANCE...ITS POSSIBLE THAT SOME AREAS OVER THE WESTERN PIEDMONT
WILL APPROACH FREEZING BY MONDAY MORNING. RIGHT NOW IT APPEARS A
LIGHT WIND AND DRYING WILL PREVENT WIDESPREAD FROST.
THE SHOT OF COLDER AIR LOOKS TO BE VERY BRIEF AS A SHORTWAVE RIDGE
AND SURFACE HIGH PRESSURE BUILD OVER THE REGION...AND BEGIN AN
EVOLUTION INTO A PERSISTENT RIDGE OVER THE SOUTHEAST US. WITH A
LIGHT NORTHWEST WIND AND NEUTRAL THERMAL ADVECTION...LOW LEVEL
THICKNESSES AROUND 1320M MONDAY MORNING SUPPORT MET MOS GUIDANCE
MORE SO THAN THE MAV MOS...UPPER 60S NORTHEAST TO AROUND 70
SOUTHWEST. LOWS MONDAY NIGHT 39-44.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 330 AM SATURDAY...
A RIDGE WILL DEVELOP OVER THE SOUTHEAST BY TUESDAY IS IS FORECAST TO
PERSIST THROUGH MUCH OF THE WEEK. THE PRIMARY STORM TRACK WILL BE
THROUGH THE MIDWEST AND GREAT LAKES REGION...WITH A WEAK FRONT
EXPECTED TO MOVE INTO THE MID-ATLANTIC STATES LATE TUESDAY AND THEN
WASH OUT WITHOUT HAVING MUCH...IF ANY IMPACT ON CENTRAL NC. MEDIUM
RANGE MODELS SHOW THE RIDGE HOLDING STRONG UNTIL LATE IN THE
WEEK...WHEN THE RIDGE FINALLY BREAKS DOWN AND A FRONTAL ZONE PUSHES
EAST INTO CENTRAL NC FRIDAY/FRIDAY NIGHT.
THIS PATTERN SUPPORTS A MUCH WARMER PERIOD FOR CENTRAL NC...WITH
THICKNESSES AS MUCH AS 20-30M ABOVE NORMAL AND HIGHS IN THE 70S OR
EVEN 80 IN THE SOUTHEAST BY WED/THURS.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
06Z TONIGHT. SOME IMPROVEMENT FROM IFR TO MVFR IS EXPECTED AT
INT/GSO TOWARD THE END OF THE TAF VALID PERIOD AT 12Z. A DEEP MOIST
FLOW FROM THE SOUTH AND SW... AHEAD OF A STRENGTHENING STORM SYSTEM
NOW MOVING THROUGH MS AND WRN TN... WILL BRING IFR/LIFR CONDITIONS
AND PERIODS OF MOSTLY LIGHT RAIN THROUGH DAYBREAK. WE SHOULD SEE A
BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN THROUGH THE LATE MORNING
THROUGH EARLY AFTERNOON HOURS... MOST LIKELY FROM 14Z TO 19Z... BUT
CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME... WITH IFR/LIFR CONDITIONS MOST LIKELY AT INT/GSO. THEN
STARTING SOON AFTER 19Z... A LINE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC THROUGH THE LATE
AFTERNOON/EARLY EVENING HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
02Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH LATE EVENING AND INTO EARLY OVERNIGHT. WINDS WILL SHIFT TO
BE FROM THE NW WITH THE COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT
INT/GSO... BETWEEN 04Z AND 06Z AT RDU.... AND BETWEEN 07Z AND 09Z AT
RWI/FAY.
LOOKING BEYOND 12Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM EDT THIS MORNING FOR NCZ007>009-
021>025-038>040-073-074-083.
&&
$$
SYNOPSIS...HARTFIELD
NEAR TERM...HARTFIELD
SHORT TERM...SMITH
LONG TERM...SMITH
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
943 AM EDT SAT MAR 29 2014
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL FORM OVER KENTUCKY AND TENNESSEE
AND MOVE TO THE DELMARVA REGION BY TONIGHT. THE ASSOCIATED UPPER
LEVEL TROUGH WILL GET DEEPER...SLOWING DOWN THE SYSTEM
SIGNIFICANTLY. MILDER TEMPERATURES BUT CONTINUED UNSETTLED
CONDITIONS ARE EXPECTED FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE NW EDGE OF A LARGE SHIELD OF STEADY LIGHT TO MODERATE RAIN
CONTINUES TO DRIFT NORTH AND IS ENTERING FAR SERN YORK COUNTY AND
SERN LANCASTER COUNTY AT 13Z. THIS WILL BE A LONG-DURATION PRECIP
EVENT FOR MOST OF THE CWA...LASTING BETWEEN 36-48 HOURS.
THE BULK OF THE PRECIP WILL FALL AS RAIN OF VARYING
INTENSITY...BUT LATER SECTIONS OF THIS DISCUSSION WILL COVER THE
WINTRY ASPECTS OF THIS SLOW-MOVING WEATHER SYSTEM /EXPECTED TO
IMPACT THE HIGHER TERRAIN OF THE NORTH AND WEST AS WE PROGRESS
LATER INTO THE WEEKEND.
FOR THE NEAR TERM...POCKETS OF SUNSHINE THROUGH THIN CIRRUS JUST
NORTH OF THE I-80 CORRIDOR /AND SANDWICHED BETWEEN LOWER
STRATUS/STRATOCU AND NS CLOUDS TO THE SOUTH AND NORTH/ WILL VANISH
DURING THE MIDDAY HOURS AS THICKER...LAYERED CLOUDS SPREAD IN FROM
THE SOUTH.
12Z 13KM RAP AND 09Z SREF INDICATE THAT MUCH OF CENTRAL AND NRN
PENN WILL STAY DRY UNDER MAINLY A MID CLOUD DECK THROUGH 18-20Z
BEFORE THE RAIN ENCROACHES FROM THE SW AND SE.
PRACTICALLY ALL LOCATIONS IN THE CWA SHOULD SEE RAIN BY 23Z
TODAY...WITH THE HIGHEST TOTALS /BETWEEN 0.25-0.50 OF AN INCH/
OCCURRING ACROSS THE LAURELS...AND FAR SERN COUNTIES.
TEMPS REMAIN IN THE 30S FOR A LARGE PORTION OF THE AREA LATE THIS
MORNING /AFTER EXTENDED PERIODS OF CLEAR TO PARTLY CLOUDY SKIES
OVERNIGHT/... BUT ARE IN THE 40S TO NEAR 50F ACROSS THE LOWER SUSQ
VALLEY WHERE CLOUD COVER ADVANCED INTO THAT REGION MUCH EARLIER.
AS THE CLOUDS THICKEN AND RAIN GRADUALLY OVERSPREADS THE
AREA THIS AFTERNOON...TEMPS WILL SLOW THEIR CLIMB AND LEVEL
OFF. HIGHS WILL VARY FROM THE U30S IN THE NW...TO AROUND 50F IN
THE SE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
THE STORM DEEPENS RAPIDLY AS IT MOVES OVER THE MID-ATLANTIC
STATES. THE UPPER LEVEL TROUGH CUTS OFF AND THE WIND PULLS IN LOTS
OF MOISTURE...MAINLY FROM THE SOUTH/GOMEX. BUT THE SYSTEM ALMOST
STALLS OVERHEAD. THIS WILL CREATE HEAVY RAIN FOR MUCH OF THE
AREA...BUT MAINLY OVER THE EAST WHERE FLOOD WATCH IS ALREADY IN
EFFECT. SEE HYDRO SECTION FOR MORE ON WATER ISSUES.
THE OTHER TROUBLE WITH THE PRECIP IS THAT THE TEMPS DO DROP IN THE
EVENING AND ESPECIALLY OVERNIGHT. THUS...THE NORTHWESTERN
COUNTIES AND HIGHER ELEVATION IN THE CENTRAL MTNS WILL LIKELY SEE
THE RAIN TURN TO SNOW AS THE NIGHT CONTINUES. SOME INDICATIONS OF
FREEZING RAIN...WITH TEMPS COOLING BELOW FREEZING BEFORE THE
ENTIRE COLUMN COOLS. THUS...HAVE MENTIONED CHC ZR IN THE GRIDS
FOR THE SECOND HALF OF THE NIGHT ALONG WITH THE TURN OVER TO SNOW
- WHICH IS MORE LIKELY TO OCCUR. TEMPS DO NOT SEEM TO EVER GET AOB
FZG IN THE RIDGE AND VALLEY REGION SO...WILL JUST GO WITH A
GRADUAL CHANGE/MIX HERE. QPF IN THE NORTHWEST AFTER THE CHANGE TO
SNOW IS A VERY DIFFICULT PART OF THE FCST. IN GENERAL...THE
EXPECTATION IS THAT THE HEAVY PRECIP WILL BE TO THE EAST BY THE
MIDDLE OF THE NIGHT...AND SNOW ACCUMS SHOULD BE AN INCH OR TWO IN
THE FAR NWRN COS...BUT IF IT TURNS MORE-QUICKLY...3-4 INCHES IS
POSSIBLE. BUT...WILL KEEP THE FCST CONSERVATIVE AT THIS POINT.
THE DAYTIME ON SUNDAY SHOULD HELP TEMPS RISE SLIGHTLY...BUT THE
UPPER LOW/TROUGH AXIS WILL BE RIGHT OVERHEAD. CLOUDS WILL BE THICK
EVEN WHERE THE PRECIP GETS LIGHTER/SPOTTY. IT WONT FEEL TOO NICE
WITH TEMPS IN THE 30S NW AND L-M40S ELSEWHERE. THE WIND WILL GET
CRANKING WITH THE DEEPENING SFC LOW VERY CLOSE BY. HAVE NUDGED
POPS UP FOR SUNDAY AND EARLY SUNDAY NIGHT TO ALLOW FOR THE FURTHER
SLOW-DOWN IN THE CONSENSUS OF MDL DATA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
LATEST MODEL SOLUTIONS CONTINUE TO SLOW DOWN THE PROGRESSION OF THIS
WEEKEND/S STORM...RESULTING IN LINGERING SHOWERS OVER THE EAST FOR
SUNDAY. TEMPERATURES WILL BE COLD ENOUGH SATURDAY NIGHT AND INTO
THE MORNING HOURS ON SUNDAY FOR THE PRECIPITATION TO FALL AS A
LIGHT DUSTING OF SNOW OVER THE NORTH AND HIGHER ELEVATIONS.
AT THIS POINT...MONDAY WILL BE ONE OF THE BEST DAYS OF THE
EXTENDED FORECAST WITH HIGH PRESSURE...FAIR SKIES...AND SEASONABLE
TEMPERATURES. A LOW PRESSURE SYSTEM WILL SLIDE NORTH OF THE STATE
TUESDAY NIGHT...BRINGING MORE CLOUDS TO THE REGION. LIGHT SHOWERS
CANNOT BE RULED OUT ACROSS THE NORTH AS A WEAK COLD FRONT MOVES
THROUGH. SUNSHINE WILL MAKE A BRIEF RETURN FOR WEDNESDAY BEFORE
ANOTHER STORM SYSTEM ORGANIZES OVER THE MIDWEST...AND MOVE EAST
FOR THE END OF THE WEEK. THERE IS STILL A GOOD BIT OF MODEL
SPREAD...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AS THE
ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL
MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND
BRINGING MORE RAIN.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
MAIN AVIATION CONCERN EARLY THIS MORNING WILL BE LOW CIGS ACROSS
THE N MTNS...THE RESULT OF RESIDUAL LOW LVL MOISTURE TRAPPED
BENEATH INVERSION AND FORCED TO ASCEND THE HIGH TERRAIN OF
NORTHERN PA. KBFD CONTINUES TO REPORT A CIG OF JUST 200FT AT
13Z...AND THIS SHOULD PERSIST FOR AT LEAST THE NEXT HOUR OR
SO...YIELDING TO AN IFR TO MVFR DECK OF STRATO CU THIS AFTERNOON.
ELSEWHERE...MVFR STRATO CU WERE NOTED ACRS THE LOWER SUSQ VALLEY
/INCLUDING KMDT......KCXY...KTHV AND KLNS/ WITH VFR BKN-OVC ALTOCU
ELSEWHERE. LITTLE CHANGE IN THESE CONDITIONS ARE EXPECTED THROUGH
THIS AFTERNOON.
DEVELOPING LOW PRESSURE OVR THE SE STATES WILL LIFT UP THE
APPALACHIAN MTNS LATER TODAY...HELPING TO SPREAD RAIN AND LOWERING
CIGS NORTHWARD ACROSS PENNSYLVANIA. EXPECT WIDESPREAD IFR/LIFR
CONDS IN RAIN/LOW CIGS LATE THIS AFTN AND EVENING...AS THE STORM
SYSTEM APPROACHES PA. COLDER AIR WRAPPING INTO THIS SYSTEM COULD
CHANGE RAIN TO MIXED PRECIP AT KBFD LATE THIS EVENING...WHILE
UNSTABLE AIR WORKING INTO SE PA COULD POTENTIALLY SPAWN A FEW TSRA
ARND KMDT AND KLNS THIS EVENING.
OUTLOOK...
SUN...WINDY. RAIN/LOW CIGS POSS...ESP EAST.
MON-WED...NO SIG WX EXPECTED.
&&
.HYDROLOGY...
FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA FOR LATER
TODAY THROUGH SUNDAY NIGHT. THE UPPER LOW IS EXPECTED TO CLOSE
OFF AND POSSIBLY STALL ALONG MID ATLC COAST. THIS WILL PRODUCE
MDT TO HEAVY RAINS OVER MUCH OF THE AREA DURING THIS PD.
THE HIGHER AMOUNTS STILL LOOK TO BE IN THE EAST...ESPECIALLY IF
A WIDELY PROGGED DEFORMATION-TYPE AREA OF PRECIP FORMS ON SUNDAY.
LOCALIZED STORM TOTAL AMOUNTS OF 1-2 INCHES SEEM REASONABLE. BUT
IF IT CONTINUES TO LOOK LIKE THE PRECIP WILL RE-INVIGORATE ON
SUNDAY...THE WATCH MAY NEED TO BE EXTENDED. GEFS/SREF GUIDANCE
SHOWS PWAT ANOMALIES GREATER THAN 2 STANDARD DEVIATES OVER EASTERN
PA SAT AFTN AND EVENING PROVIDING SUFFICIENT MOISTURE FOR HIGH
RAINFALL RATES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR PAZ028-036-037-041-042-
046-049>053-056>059-063>066.
&&
$$
SYNOPSIS...LAMBERT/DANGELO
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...COLBERT
AVIATION...LAMBERT/FITZGERALD
HYDROLOGY...LAMBERT/DANGELO
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
600 AM CDT SAT MAR 29 2014
.UPDATE...
12Z TAF DISCUSSION.
&&
.AVIATION...
-SHRA WILL CONTINUE SPREADING ACROSS AREA AIRPORTS THIS MORNING
BEFORE EXITING CKV/BNA BY EARLY AFTERNOON AND CSV BY EVENING.
LITTLE LIGHTNING HAS BEEN NOTED AND WILL LEAVE OUT MENTION OF TS.
MVFR/IFR CIGS TO BECOME VFR LATE IN THE TAF PERIOD AT
CKV/BNA...BUT THESE CIGS MAY LINGER AT CSV. LIGHT
SOUTHEAST/NORTHEAST WINDS WILL BECOME NORTHWEST AND GUSTY BY
AFTERNOON AS COLD FRONT MOVES ACROSS.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 335 AM CDT SAT MAR 29 2014/
DISCUSSION...
SFC LOW WL MOVE FROM EASTERN MS ACRS E TN TDY. INVERTED TROF OVER
THE MID STATE WILL ALSO SHIFT EAST AND ALLOW COLDER AIR TO FILTER
IN. THE MAIN CHALLENGES IN THE NEAR TERM INVOLVE PCPN CVRG AND HOW
MUCH TEMPS WL RECOVER AS PCPN PULLS OUT LATER. FOR NOW LEANED PCPN
FCST TWRD THE LATEST HRRR WHICH HAS HAD A PRETTY GOOD HANDLE ON
THINGS THUS FAR. XPCT TO SEE RAIN INCRS IN CVRG QUICKLY OVER THE
NEXT FEW HOURS AND GRADUALLY EVOLVE INTO A BIT OF A COMMA HEAD
BEFORE PULLING OUT LATER THIS AFTN. RAIN WILL LIKELY NOT REACH THE
PLATEAU UNTIL MID MORNING AND WILL BE ENDING ALONG THE TN RIVER BY
MIDDAY. AS FAR AS TEMPS GO...HIGHS ARND NASHVILLE AND POINTS EAST
WILL LIKELY BE RIGHT ARND 8 AM JUST AHEAD OF THE BNDRY WITH A
PRETTY SHARP DROP THRU THE MORNING. WILL SEE SOME TEMPERATURE RECOVERY
AGAIN IN THE AFTN AS RAIN CVRG DECREASES.
SOME RAIN MAY LINGER IN THE FAR EAST ERLY THIS EVE OTHW XPCT A
QUICK CLEARING AS SYS PULLS AWAY. MAV TEMPERATURES LOOK RSNBL
GIVEN THE CLEARING SKIES AND A PRETTY COOL START. WX THEN LOOKS
NICE AND SPRINGLIKE INTO MID-WEEK AS RIDGING DOMINATES. STILL WL
HV TO WATCH WEAK FRONT ON TUE FOR SOME CLDS AND A LITTLE LIGHT
PCPN BUT DOESN`T LOOK LIKE MUCH RIGHT NOW. HPC TEMPS WERE FOLLOWED
PRETTY CLOSE.
THE FAR EXTENDED STILL LOOKS ACTIVE BUT AS IS TYPICAL THE ALL
IMPORTANT DETAILS ARE MURKY. GENERAL PATTERN SUGGESTS WARM AND
HUMID CONDITIONS WITH ROUNDS OF SHOWERS AND STORMS AS SFC LOWS
MOVE TO OUR WEST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
55
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
709 AM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT MAR 29 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY DEEP TROUGH OFF THE PACIFIC NORTHWEST...RIDGING
PUSHING EASTWARD ACROSS THE ROCKIES...AND TROUGHING FROM MINNESOTA
SOUTH INTO ARKANSAS. THE NORTHERN PORTION OF THIS TROUGH HAS BEEN
UNEVENTFUL FOR THE FORECAST AREA...BRINGING ONLY SOME MID/HIGH
CLOUDS. DRY AIR SITUATED BETWEEN 900-700MB ON THE 00Z GRB...MPX AND
DVN SOUNDINGS KEPT ANY POTENTIAL PRECIPITATION FROM THESE CLOUDS
FROM REACHING THE GROUND. HOWEVER...AT AND BELOW 900MB...
OBSERVATIONS ARE SHOWING SOME LOW STRATUS DEVELOPING ACROSS
SOUTHERN WI. THIS STRATUS IS A RESULT OF EASTERLY FLOW OF MOISTURE
FROM LAKE MICHIGAN COMBINING WITH NOCTURNAL COOLING AND AN INVERTED
SURFACE TROUGH IN THE AREA. TO THE NORTHWEST...CLEARING ASSOCIATED
WITH SURFACE HIGH PRESSURE WAS PRESENT ACROSS MUCH OF MINNESOTA.
AIRMASS OVER THE UPPER MIDWEST STILL RELATIVELY COOL WITH 00Z RAOBS
SHOWING 925MB TEMPS OF -3 TO -5C FROM THE FORECAST AREA TO BIS.
HOWEVER...LBF AND UNR ON THE BACK SIDE OF THE SURFACE HIGH WERE MUCH
WARMER AT +11 AND +15C RESPECTIVELY.
A PROGRESSIVE UPPER FLOW PATTERN IS PROGGED THROUGH THE SHORT TERM
PERIOD AS A VIGOROUS SHORTWAVE AT THE BOTTOM OF THE EAST PACIFIC
TROUGH...NEAR 35 NORTH / 140 WEST...MOVES INTO CALIFORNIA. FOR
COMPARISON...THE FORECAST AREA GOES FROM UNDER A SHORTWAVE TROUGH
AXIS AT 12Z SATURDAY TO A RIDGE AXIS AT 12Z SUNDAY. 3 MAIN
IMPACTS FROM THIS SWITCH:
1. SUBSIDENCE AND DRYING ASSOCIATED WITH BUILDING UPPER RIDGING WILL
HELP CLEAR OUT ANY LOW CLOUDS BY 18Z...LEADING TO A SUNNY AFTERNOON
WITH JUST SOME SCATTERED CIRRUS TONIGHT.
2. AFTER MOSTLY A LIGHT WIND FLOW TODAY AS SURFACE RIDGE MOVES
THROUGH...SOUTHERLY WINDS INCREASE GREATLY TONIGHT...ESPECIALLY FROM
925-850MB. BY 12Z SUNDAY...THEY ARE RUNNING BETWEEN 40-50 KT.
3. 925-850MB TEMPS FOLLOW THE INCREASE IN WINDS. FOR EXAMPLE...
925MB TEMPS AFTER STARTING OFF BETWEEN -2 TO -5C AT 12Z THIS MORNING
CLIMB TO 0 TO +3C AT 00Z SUNDAY...THEN TO 2 TO +5C AT 12Z SUNDAY.
SUNSHINE SHOULD EASILY BOOST HIGHS INTO THE 40S TODAY AT MOST
LOCATIONS...WITH A FEW VALLEY AREAS APPROACHING 50. TEMPERATURES
SHOULD BOTTOM OUT THIS EVENING BEFORE THE LOW LEVEL JET INCREASES
AND CAUSES THEM TO STABILIZE. READINGS SHOULD RISE LATE TONIGHT AS
THE WARMER AIR FLOWS IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT MAR 29 2014
MANY WEATHER CONCERNS TO HIGHLIGHT DURING THE LONG TERM PERIOD AS
THE FORECAST AREA LOOKS TO RESIDE MUCH OF THE TIME IN SOUTHWEST FLOW
ALOFT.
1. ABOVE NORMAL TEMPERATURES SUNDAY THROUGH MONDAY. THE VIGOROUS
SHORTWAVE COMING INTO CALIFORNIA TONIGHT REMAINS ON TRACK TO LIFT
INTO EASTERN SOUTH DAKOTA OR SOUTHWEST MN BY 00Z TUESDAY...PUSHING
WARM...DOWNSLOPED AIR OFF THE ROCKIES INTO THE FORECAST AREA AHEAD
OF IT. 925MB TEMPS ARE PROGGED TO CLIMB TO 9-13C BY 00Z
MONDAY...COOLEST OVER TAYLOR/CLARK COUNTIES. THESE READINGS COMBINED
WITH SUN THROUGH SCT-BKN CIRRUS AND BREEZY SOUTHERLY WINDS SHOULD
PUSH TEMPERATURES INTO THE 60S ALONG/SOUTHWEST OF I-94...WITH 50S TO
THE NORTH. A SOUTHERLY BREEZE PERSISTS INTO SUNDAY NIGHT AND
MONDAY. THIS WIND SHOULD ONLY ALLOW TEMPERATURES TO FALL INTO THE
40S SUNDAY NIGHT...WITH MAYBE SOME 30S IN THE TYPICAL COLD SPOTS.
THEN ON MONDAY...WITH MODEL CONSENSUS KEEPING THE FORECAST AREA IN
THE WARM SECTOR HIGHLIGHTED BY 925MB TEMPS OF 9-13C...SHOULD SEE
ANOTHER DAY OF HIGHS MOSTLY IN THE MID 50S TO MID 60S. THIS OCCURS
DESPITE SOME WARM ADVECTION PRECIPITATION MOVING THROUGH.
2. PRECIPITATION AND THUNDERSTORM POTENTIAL MONDAY INTO MONDAY
NIGHT. THE SIGNAL STILL EXISTS FOR A WARM CONVEYOR BELT OF
SHOWERS TO MOVE ACROSS THE FORECAST AREA...ESPECIALLY DURING THE
LATE MORNING AND AFTERNOON HOURS...AS ISENTROPIC LIFT ON 300K
SURFACES AND ABOVE INCREASES. THE BEST MOISTURE EXISTS NORTH OF I-
90...THUS HIGHEST CHANCES OF 50-70 ARE SITUATED THERE. THE POTENTIAL
STILL EXISTS FOR A BAND OF SHOWERS AND SOME EMBEDDED THUNDERSTORMS
TO FORM ALONG THE COLD FRONT CROSSING LATE IN THE AFTERNOON AND
EVENING. HOWEVER...A COUPLE OF CONCERNS FOR THIS BAND INCLUDE MODELS
MAY BE OVERDOING THE MOISTURE RETURN AND NOT MIXING DEWPOINTS OUT
ENOUGH...AND THE TIME OF DAY IS BEING PUSHED TO OUTSIDE OF PEAK
HEATING. SHOULD STORMS FIRE...THERE REMAINS AMPLE SHEAR TO ALLOW FOR
SEVERE WEATHER. LASTLY...CONFIDENCE HAS INCREASED THAT THE
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE ASSOCIATED SURFACE LOW
WILL TRACK NORTHWEST OF THE FORECAST AREA ON MONDAY...AND CLIP THE
NORTHWEST HALF OF THE FORECAST AREA MONDAY NIGHT BEFORE LIFTING OFF
TO THE NORTHEAST. COLDER AIR RUSHING IN SHOULD ALLOW FOR A
CHANGEOVER TO SNOW...WITH A BRIEF PERIOD OF SLEET POSSIBLE DURING
THIS CHANGEOVER AS COLD AIR UNDERCUTS WARMER AIR ALOFT. LITTLE SNOW
ACCUMULATION IS EXPECTED...THOUGH. THERE IS ALSO POTENTIAL TO LOSE
ICE IN THE CLOUDS DUE TO A DRY SLOT...BUT THE LOSS OF ICE OCCURS
EITHER WHERE TEMPERATURES ARE ABOVE FREEZING TO RESULT IN RAIN OR
WHERE NO PRECIPITATION WILL OCCUR.
3. WINDS MONDAY AFTERNOON AND NIGHT. ECMWF/GFS PROG 925MB WINDS OF
30-40 KT SOUTH OF I-90 DURING THE AFTERNOON. IF MORE SUN OCCURS THAN
EXPECTED...THESE COULD EASILY MIX DOWN TO THE SURFACE AND SEE
BOTH SUSTAINED WINDS AND GUSTS APPROACH ADVISORY. INCREASED WINDS
AND GUSTS AS A RESULT. ALSO...AS THE LOW PASSES TO OUR
NORTHEAST...A TIGHT PRESSURE GRADIENT WITH 925MB WINDS OF 30-40 KT
FROM THE SOUTHWEST TO WEST USHERS IN COLD AIR. WITH SOME ISALLOBARIC
AID...COULD SEE GUSTS HERE TOO APPROACH ADVISORY FOR A BRIEF TIME.
4. WINTRY MIX POTENTIAL LATE TUESDAY NIGHT THROUGH FRIDAY. MODELS
ARE AT ODDS ON HOW TO HANDLE THE EJECTION OF TROUGHING OUT OF THE
SOUTHWESTERN U.S. ON TUESDAY TOWARDS THE REGION LATER IN THE WEEK.
THERE WILL NO DOUBT BE A COLDER DOME OF HIGH PRESSURE INFLUENCING
THE AREA...LIKELY SITUATED FROM NORTHERN MN INTO UPPER MI. IN
ADDITION...AS THE TROUGH EJECTS...ISENTROPIC LIFT OF WARMER...GULF
OF MEXICO MOISTURE WILL SPREAD PRECIPITATION NORTH TOWARDS THE
FORECAST AREA. THIS SETS UP CONCERN FOR THE WINTRY MIX. FOR NOW HAVE
FOLLOWED A MODEL CONSENSUS WITH PRECIPITATION CHANCES...WHICH SEEMS
MOST LIKELY TO OCCUR WEDNESDAY SOUTH OF I-90. ALSO KEPT TYPES AS
RAIN/SNOW BASED ON HOURLY TEMPERATURES...BUT THERE IS DEFINITELY
POTENTIAL FOR SLEET AND FREEZING RAIN/DRIZZLE AT TIMES. 29.00Z ECMWF
EVEN PRODUCES AT LEAST ADVISORY WORTHY SNOWFALL OVER THE NORTHWEST
HALF OF THE AREA THURSDAY AND THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 709 AM CDT SAT MAR 29 2014
VFR CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY AS HIGH
PRESSURE BUILDS IN FROM THE NORTHERN PLAINS. A STRONG LOW PRESSURE
SYSTEM WILL DEVELOP OVER THE CENTRAL PLAINS TONIGHT CREATING A
TIGHT PRESSURE GRADIENT OVER THE UPPER MISSISSIPPI RIVER VALLEY.
SOUTH WINDS WILL INCREASE TO AROUND 17 KTS AT KRST AND INTO THE
10 TO 12 KT RANGE AT LSE. ALSO...WINDS INCREASE TO 45 TO 50 KTS IN
THE 1500 TO 2000 FT LAYER LEADING TO LOW LEVEL WIND SHEAR
CONCERNS MAINLY AFTER 10Z. HAVE INCLUDED LOW LEVEL WIND SHEAR IN
THE KRST TAF STARTING AT 09Z. CONFIDENCE NOT AS HIGH AT KLSE ON
THE WINDS ABOVE THE SURFACE BEING STRONG ENOUGH LLWS PRIOR TO 12Z
SO HAVE NOT INCLUDED IT IN THE TAF AT THIS TIME.
&&
.HYDROLOGY...
ISSUED AT 328 AM CDT SAT MAR 29 2014
MAIN FOCUS FOR RIVER ISSUES FROM THE RECENT RAIN IS ON THE KICKAPOO
RIVER. SOME LOCATIONS ALONG IT ARE EITHER IN OR EXPECTED TO REACH
FLOOD STAGE AS RUNOFF CONTINUES TO WORK ITS WAY DOWNSTREAM.
FROM SUNDAY INTO MONDAY NIGHT...THE RAPID WARM UP WILL CAUSE THE
SNOW PACK NORTH OF INTERSTATE 94 TO MELT RAPIDLY. IN
ADDITION WITH FROZEN GROUND...ANY RAINFALL ON MONDAY AND
MONDAY NIGHT WILL QUICKLY RUNOFF INTO AREA RIVERS AND STREAMS. THIS
WILL RESULT IN RISES ALONG THE BLACK...BUFFALO...AND TREMPEALEAU
RIVERS IN WESTERN WISCONSIN. SOME FLOODING IS ALSO A POSSIBILITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
914 AM MDT SAT MAR 29 2014
.UPDATE...
ISSUED AT 901 AM MDT SAT MAR 29 2014
WILL HAVE TO KEEP A CLOSE EYE ON WIND SPEEDS IN THE ARLINGTON AREA
TODAY. WINDS HAVE GUSTED AS HIGH AS 57 MPH AT THE ARLINGTON WY DOT
SITE WITH OTHER SITES GUSTING 50 TO 55 MPH. MODELS DO SHOWING
WINDS ALOFT INCREASING SLIGHTLY THIS AFTERNOON BUT NOT AS STRONG
OF SUBSIDENCE. AT THIS TIME WILL HOLD OFF ON ANY HEADLINES AS
WINDS SHOULD BE MARGINAL FOR A HIGH WIND WARNING AND RELATIVELY
LOCALIZED.
UPDATED THE SKY GRIDS AS THE STANDING WAVE CLOUDS IS IN PLACE
ALONG AND EAST OF THE LARAMIE RANGE. MODELS INDICATE THE WAVE
COULD WILL THIN OUT THIS AFTERNOON. SHOULD NOT SEE A BIG IMPACT ON
TEMPERATURES TODAY BUT IT WILL BE A SLOWER RISE IN TEMPERATURES
AND COULD END UP A FEW DEGREES BELOW THE CURRENT FORECAST WHERE
THE WAVE CLOUD HANGS ON THE LONGEST. OTHERWISE FORECAST IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
MAIN WEATHER STORIES THROUGH THIS EVENING WILL BE THE WARM
TEMPERATURES AND ASSOCIATED FIRE WEATHER CONCERNS AND THE WINDY
CONDITIONS ALONG AND WEST OF THE LARAMIE RANGE. HIGHS THIS AFTN ARE
STILL EXPECTED TO CLIMB INTO THE 60S AND LOWER 70S ACROSS THE
PLAINS. MAIN CHANGE TO THE FCST GRIDS FOR THIS AFTN WAS TO DECREASE
DEWPOINTS...ESPECIALLY STRETCHING FROM LARAMIE COUNTY INTO THE
SOUTHERN PANHANDLE. DEEP SOUTHWESTERLY FLOW IN THE LOW-TO-MIDLEVELS
WILL COMBINE WITH EXCELLENT SOLAR INSULATION TO PRODUCE DEEP LLVL
MIXING THIS AFTN AND IT IS THESE CONDITIONS THAT MOS OFTEN GROSSLY
UNDERESTIMATES AFTN DEWPOINTS. WENT WITH A BLEND OF THE DRIER MAV
AND RUC GUIDANCE AND THIS RESULTS IN MIN RH VALUES IN THE 10-15
PERCENT RANGE OVER THE PANHANDLE. EXCELLENT MIXING WILL TAP INTO
25-30 KTS AT THE TOP OF THE MIXED LAYER. THUS...DECIDED TO ISSUE A
RFW FOR THE ENTIRE PANHANDLE.
THE NEXT ITEM OF CONCERN IS WINDS TO THE WEST OF THE LARAMIE RANGE.
THE GFS SHOWS 700MB WINDS OF 40-45 KTS FROM 18-00Z AND THE 700MB
CAG-CPR GRADIENT IS AROUND 45 METERS. CONTEMPLATED PUTTING THE
ARLINGTON AREA IN A HIGH WIND WARNING FOR THE AFTN...HOWEVER WOULD
LIKE TO SEE THE LLVL GRADIENT AND WINDS ALOFT A BIT STRONGER. WILL
LIKELY SEE GUSTS AROUND 45 KTS IN THE ARLINGTON AREA WITH THE
FAVORABLE GAP WINDS. OUTSIDE OF ARLINGTON...COULD SEE GUSTS TO 40
KTS DURING PEAK MIXING. THE LLVL GRADIENT COMES DOWN BY THIS
EVENING AND FLOW ALOFT BECOMES MORE SOUTHWESTERLY...SO WILL SEE
WINDS DECREASE.
ANOTHER WARM DAY ON SUNDAY AHEAD OF A SHORTWAVE. KEPT A SLIGHT
CHANCE OF AFTN TSTMS IN THE FCST AS BOTH THE GFS AND NAM INDICATE
LIFTED INDICES OF 0C TO -1C. MODELS CONTINUE TO INDICATE THAT THE
UPPER LEVEL SYSTEM WILL MOVE DIRECTLY OVERHEAD ON SUNDAY NIGHT WITH
A FROPA AFTER 06Z MON. BEST UPPER LEVEL DIVERGENCE AND LARGE SCALE
LIFT IS LARGELY OFF TO THE NORTHEAST OF THE CWA...HOWEVER MAY HAVE
TO WATCH THE NORTHEAST ZONES FOR ADVISORY AMOUNTS. THIS AREA WILL
BE CLOSEST TO THE WESTERN EDGE OF A DEVELOPING TROWAL/FRONTOGENESIS
FEATURE OVER SOUTH DAKOTA. JUST SOMETHING TO WATCH IN FUTURE MODEL
RUNS.
.LONG TERM...(EARLY TUESDAY MORNING THROUGH FRIDAY)
ISSUED AT 445 AM MDT SAT MAR 29 2014
MAIN FORECAST CONCERN NEXT WEEK WILL BE A SLOW MOVING UPPER LEVEL
LOW MOVING ACROSS THE GREAT BASIN REGION AND INTO THE ROCKY
MOUNTAINS BY WEDNESDAY. ALTHOUGH MODELS ARE IN POOR AGREEMENT WITH
THIS SYSTEM AND HAVE BEEN OVER THE LAST 48 HOURS...THERE IS STILL
CONCERN OVER A POTENTIAL SIGNIFICANT STORM OVER PORTIONS OF THE
HIGH PLAINS.
FOR TUESDAY...ALL MODELS NOW SHOW THE COLD FRONT FROM SUNDAYS
SYSTEM ALONG THE CONTINENTAL DIVIDE...RETREATING EASTWARD AS A
WARM FRONT. WARM AIR ADVECTION ALOFT AND COOL UPSLOPE FLOW WILL
COMBINE TO PRODUCE OVERRUNNING PRECIPITATION IN THE FORM OF SNOW
ACROSS THE FORECAST AREA. INCREASED POP BETWEEN 30 TO 50 PERCENT
ACROSS MOST OF THE FORECAST AREA WITH THE EXCEPTION OF EXTREME
EASTERN ZONES ACROSS THE SOUTHERN NEBRASKA PANHANDLE. 1 TO 2
INCHES OF SNOW LOOKS POSSIBLE WITH THIS INITIAL OVERRUNNING EVENT
TUESDAY...ESPECIALLY NORTH OF I80. AS THE WARM FRONT LIFTS
NORTHEAST DURING THE DAY...THE SNOW WILL QUICKLY MELT AND/OR
CHANGE TO RAIN AS TEMPERATURES INCREASE INTO THE 50S.
ATTENTION THEN SHIFTS WESTWARD TUESDAY NIGHT AS THE MAIN UPPER
LEVEL LOW MOVES ACROSS THE GREAT BASIN. MODELS ARE STRUGGLING WITH
THE PLACEMENT...MOVEMENT...AND POTENTIAL EVOLUTION OF A STRONG
WINTER STORM. ALL MODELS INDICATE A BRIEF BREAK EARLY WEDNESDAY
BEFORE THE UPPER LEVEL LOW MOVES INTO THE ROCKY MOUNTAIN REGION
AND ATTEMPTS TO BECOME BETTER ORGANIZED. THE ECMWF SHOWS A RATHER
DISORGANIZED STORM SYSTEM...WITH THE MAIN LOW EJECTING NORTHEAST
AND THEN DRIFTING EASTWARD INTO THE DAKOTAS...WHILE THE SOUTHERN
ENERGY PUSHES INTO THE GREAT PLAINS AND THEN INITIATES STRONG
CYCLOGENESIS IN KANSAS/MISSOURI LATE WEDNESDAY NIGHT. THE ECMWF
INDICATES SPLIT FLOW ACROSS SOUTHEAST WYOMING WITH LIGHT SNOW
ACCUMULATIONS NEAR I80 DUE TO THE SOUTHERN WAVE...AND LIGHT SNOW
ACROSS CENTRAL WYOMING DUE TO THE MAIN LOW WITH LITTLE IN BETWEEN.
THE GEM IS THE MOST AGGRESSIVE...SHOWING A COLORADO LOW SLOWLY
EJECTING NORTHEAST FROM THE FOUR CORNERS REGION. THIS SCENARIO
RESULTS IN WIDESPREAD MODERATE TO HEAVY SNOWFALL ACROSS THE
FORECAST AREA BEGINNING WEDNESDAY EVENING AND LASTING THROUGH
THURSDAY. THE 00Z GFS WAS CONSIDERABLY FURTHER SOUTH...WITH THE
I80 CORRIDOR GETTING CLIPPED BY LIGHT SNOWFALL. HOWEVER...THE 06Z
GFS IS FURTHER NORTH CLOSER TO THE GEM. MOST OF THE ENSEMBLE
FORECASTS WERE IN BETWEEN THE GEM AND GFS LAST NIGHT...SO KEPT POP
BETWEEN 25 TO 40 PERCENT OVER THE LOWER ELEVATIONS WITH POP NEAR
70 PERCENT IN THE MOUNTAINS THROUGH THURSDAY EVENING. WILL
CONTINUE TO CLOSELY MONITOR THIS SYSTEM THROUGH THIS WEEKEND AND
EARLY NEXT WEEK FOR CHANGES...BUT A SIGNIFICANT STORM SYSTEM
APPEARS POSSIBLE NEXT WEEK. LOWERED TEMPERATURES BELOW NORMAL
WEDNESDAY THROUGH FRIDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
ACROSS THE AREA ON FRIDAY...WITH DRIER CONDITIONS EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH LATE TONIGHT)
ISSUED AT 345 AM MDT SAT MAR 29 2014
VFR CONDITIONS EXPECTED TODAY AND TONIGHT WITH MOSTLY CLEAR SKIES.
WINDY CONDITIONS WILL RETURN TO SOUTHEAST WYOMING AFTER 15Z TODAY
WITH GUSTS UP TO 45 KNOTS POSSIBLE ALONG AND WEST OF THE LARAMIE
RANGE. IT WILL BE BREEZY ACROSS WESTERN NEBRASKA WITH GUSTS UP TO
30 KNOTS AT TIMES THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MDT SAT MAR 29 2014
A WARM AND DRY AIRMASS WILL BE IN PLACE OVER THE REGION THROUGH
THE WEEKEND. HIGHS WILL BE 10-15 DEGREES ABOVE NORMAL. MINIMUM
HUMIDITY VALUES WILL FALL INTO THE 10-15 PERCENT RANGE OVER THE
NEBRASKA PANHANDLE THIS AFTERNOON AND WILL COMBINE WITH GUSTY
SOUTHWEST WINDS TO PRODUCE CRITICAL FIRE WEATHER CONDITIONS. A RED
FLAG WARNING IS IN EFFECT THIS AFTERNOON FOR THE PANHANDLE SINCE
FUELS ARE CONDUCIVE TO FIRE GROWTH IN THAT REGION. WHILE HUMIDITY
VALUES WILL BE SIMILAR ON SUNDAY AFTERNOON...WIND SPEEDS SHOULD BE
LESS SO ONLY AN ELEVATED FIRE WEATHER THREAT IS EXPECTED. COOLER
TEMPERATURES WILL OCCUR ON MONDAY BEHIND A COLD FRONT THAT WILL
PASS OVER THE REGION ON SUNDAY NIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR NEZ311>313.
&&
$$
UPDATE...SML
SHORT TERM...FINCH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
445 AM MDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
MAIN WEATHER STORIES THROUGH THIS EVENING WILL BE THE WARM
TEMPERATURES AND ASSOCIATED FIRE WEATHER CONCERNS AND THE WINDY
CONDITIONS ALONG AND WEST OF THE LARAMIE RANGE. HIGHS THIS AFTN ARE
STILL EXPECTED TO CLIMB INTO THE 60S AND LOWER 70S ACROSS THE
PLAINS. MAIN CHANGE TO THE FCST GRIDS FOR THIS AFTN WAS TO DECREASE
DEWPOINTS...ESPECIALLY STRETCHING FROM LARAMIE COUNTY INTO THE
SOUTHERN PANHANDLE. DEEP SOUTHWESTERLY FLOW IN THE LOW-TO-MIDLEVELS
WILL COMBINE WITH EXCELLENT SOLAR INSULATION TO PRODUCE DEEP LLVL
MIXING THIS AFTN AND IT IS THESE CONDITIONS THAT MOS OFTEN GROSSLY
UNDERESTIMATES AFTN DEWPOINTS. WENT WITH A BLEND OF THE DRIER MAV
AND RUC GUIDANCE AND THIS RESULTS IN MIN RH VALUES IN THE 10-15
PERCENT RANGE OVER THE PANHANDLE. EXCELLENT MIXING WILL TAP INTO
25-30 KTS AT THE TOP OF THE MIXED LAYER. THUS...DECIDED TO ISSUE A
RFW FOR THE ENTIRE PANHANDLE.
THE NEXT ITEM OF CONCERN IS WINDS TO THE WEST OF THE LARAMIE RANGE.
THE GFS SHOWS 700MB WINDS OF 40-45 KTS FROM 18-00Z AND THE 700MB
CAG-CPR GRADIENT IS AROUND 45 METERS. CONTEMPLATED PUTTING THE
ARLINGTON AREA IN A HIGH WIND WARNING FOR THE AFTN...HOWEVER WOULD
LIKE TO SEE THE LLVL GRADIENT AND WINDS ALOFT A BIT STRONGER. WILL
LIKELY SEE GUSTS AROUND 45 KTS IN THE ARLINGTON AREA WITH THE
FAVORABLE GAP WINDS. OUTSIDE OF ARLINGTON...COULD SEE GUSTS TO 40
KTS DURING PEAK MIXING. THE LLVL GRADIENT COMES DOWN BY THIS
EVENING AND FLOW ALOFT BECOMES MORE SOUTHWESTERLY...SO WILL SEE
WINDS DECREASE.
ANOTHER WARM DAY ON SUNDAY AHEAD OF A SHORTWAVE. KEPT A SLIGHT
CHANCE OF AFTN TSTMS IN THE FCST AS BOTH THE GFS AND NAM INDICATE
LIFTED INDICES OF 0C TO -1C. MODELS CONTINUE TO INDICATE THAT THE
UPPER LEVEL SYSTEM WILL MOVE DIRECTLY OVERHEAD ON SUNDAY NIGHT WITH
A FROPA AFTER 06Z MON. BEST UPPER LEVEL DIVERGENCE AND LARGE SCALE
LIFT IS LARGELY OFF TO THE NORTHEAST OF THE CWA...HOWEVER MAY HAVE
TO WATCH THE NORTHEAST ZONES FOR ADVISORY AMOUNTS. THIS AREA WILL
BE CLOSEST TO THE WESTERN EDGE OF A DEVELOPING TROWAL/FRONTOGENESIS
FEATURE OVER SOUTH DAKOTA. JUST SOMETHING TO WATCH IN FUTURE MODEL
RUNS.
.LONG TERM...(EARLY TUESDAY MORNING THROUGH FRIDAY)
ISSUED AT 445 AM MDT SAT MAR 29 2014
MAIN FORECAST CONCERN NEXT WEEK WILL BE A SLOW MOVING UPPER LEVEL
LOW MOVING ACROSS THE GREAT BASIN REGION AND INTO THE ROCKY
MOUNTAINS BY WEDNESDAY. ALTHOUGH MODELS ARE IN POOR AGREEMENT WITH
THIS SYSTEM AND HAVE BEEN OVER THE LAST 48 HOURS...THERE IS STILL
CONCERN OVER A POTENTIAL SIGNIFICANT STORM OVER PORTIONS OF THE
HIGH PLAINS.
FOR TUESDAY...ALL MODELS NOW SHOW THE COLD FRONT FROM SUNDAYS
SYSTEM ALONG THE CONTINENTAL DIVIDE...RETREATING EASTWARD AS A
WARM FRONT. WARM AIR ADVECTION ALOFT AND COOL UPSLOPE FLOW WILL
COMBINE TO PRODUCE OVERRUNNING PRECIPITATION IN THE FORM OF SNOW
ACROSS THE FORECAST AREA. INCREASED POP BETWEEN 30 TO 50 PERCENT
ACROSS MOST OF THE FORECAST AREA WITH THE EXCEPTION OF EXTREME
EASTERN ZONES ACROSS THE SOUTHERN NEBRASKA PANHANDLE. 1 TO 2
INCHES OF SNOW LOOKS POSSIBLE WITH THIS INITIAL OVERRUNNING EVENT
TUESDAY...ESPECIALLY NORTH OF I80. AS THE WARM FRONT LIFTS
NORTHEAST DURING THE DAY...THE SNOW WILL QUICKLY MELT AND/OR
CHANGE TO RAIN AS TEMPERATURES INCREASE INTO THE 50S.
ATTENTION THEN SHIFTS WESTWARD TUESDAY NIGHT AS THE MAIN UPPER
LEVEL LOW MOVES ACROSS THE GREAT BASIN. MODELS ARE STRUGGLING WITH
THE PLACEMENT...MOVEMENT...AND POTENTIAL EVOLUTION OF A STRONG
WINTER STORM. ALL MODELS INDICATE A BRIEF BREAK EARLY WEDNESDAY
BEFORE THE UPPER LEVEL LOW MOVES INTO THE ROCKY MOUNTAIN REGION
AND ATTEMPTS TO BECOME BETTER ORGANIZED. THE ECMWF SHOWS A RATHER
DISORGANIZED STORM SYSTEM...WITH THE MAIN LOW EJECTING NORTHEAST
AND THEN DRIFTING EASTWARD INTO THE DAKOTAS...WHILE THE SOUTHERN
ENERGY PUSHES INTO THE GREAT PLAINS AND THEN INITIATES STRONG
CYCLOGENESIS IN KANSAS/MISSOURI LATE WEDNESDAY NIGHT. THE ECMWF
INDICATES SPLIT FLOW ACROSS SOUTHEAST WYOMING WITH LIGHT SNOW
ACCUMULATIONS NEAR I80 DUE TO THE SOUTHERN WAVE...AND LIGHT SNOW
ACROSS CENTRAL WYOMING DUE TO THE MAIN LOW WITH LITTLE IN BETWEEN.
THE GEM IS THE MOST AGGRESSIVE...SHOWING A COLORADO LOW SLOWLY
EJECTING NORTHEAST FROM THE FOUR CORNERS REGION. THIS SCENARIO
RESULTS IN WIDESPREAD MODERATE TO HEAVY SNOWFALL ACROSS THE
FORECAST AREA BEGINNING WEDNESDAY EVENING AND LASTING THROUGH
THURSDAY. THE 00Z GFS WAS CONSIDERABLY FURTHER SOUTH...WITH THE
I80 CORRIDOR GETTING CLIPPED BY LIGHT SNOWFALL. HOWEVER...THE 06Z
GFS IS FURTHER NORTH CLOSER TO THE GEM. MOST OF THE ENSEMBLE
FORECASTS WERE IN BETWEEN THE GEM AND GFS LAST NIGHT...SO KEPT POP
BETWEEN 25 TO 40 PERCENT OVER THE LOWER ELEVATIONS WITH POP NEAR
70 PERCENT IN THE MOUNTAINS THROUGH THURSDAY EVENING. WILL
CONTINUE TO CLOSELY MONITOR THIS SYSTEM THROUGH THIS WEEKEND AND
EARLY NEXT WEEK FOR CHANGES...BUT A SIGNIFICANT STORM SYSTEM
APPEARS POSSIBLE NEXT WEEK. LOWERED TEMPERATURES BELOW NORMAL
WEDNESDAY THROUGH FRIDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
ACROSS THE AREA ON FRIDAY...WITH DRIER CONDITIONS EXPECTED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH LATE TONIGHT)
ISSUED AT 345 AM MDT SAT MAR 29 2014
VFR CONDITIONS EXPECTED TODAY AND TONIGHT WITH MOSTLY CLEAR SKIES.
WINDY CONDITIONS WILL RETURN TO SOUTHEAST WYOMING AFTER 15Z TODAY
WITH GUSTS UP TO 45 KNOTS POSSIBLE ALONG AND WEST OF THE LARAMIE
RANGE. IT WILL BE BREEZY ACROSS WESTERN NEBRASKA WITH GUSTS UP TO
30 KNOTS AT TIMES THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MDT SAT MAR 29 2014
A WARM AND DRY AIRMASS WILL BE IN PLACE OVER THE REGION THROUGH
THE WEEKEND. HIGHS WILL BE 10-15 DEGREES ABOVE NORMAL. MINIMUM
HUMIDITY VALUES WILL FALL INTO THE 10-15 PERCENT RANGE OVER THE
NEBRASKA PANHANDLE THIS AFTERNOON AND WILL COMBINE WITH GUSTY
SOUTHWEST WINDS TO PRODUCE CRITICAL FIRE WEATHER CONDITIONS. A RED
FLAG WARNING IS IN EFFECT THIS AFTERNOON FOR THE PANHANDLE SINCE
FUELS ARE CONDUCIVE TO FIRE GROWTH IN THAT REGION. WHILE HUMIDITY
VALUES WILL BE SIMILAR ON SUNDAY AFTERNOON...WIND SPEEDS SHOULD BE
LESS SO ONLY AN ELEVATED FIRE WEATHER THREAT IS EXPECTED. COOLER
TEMPERATURES WILL OCCUR ON MONDAY BEHIND A COLD FRONT THAT WILL
PASS OVER THE REGION ON SUNDAY NIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...NONE.
NE...RED FLAG WARNING FROM 11 AM THIS MORNING TO 7 PM MDT THIS
EVENING FOR NEZ311>313.
&&
$$
SHORT TERM...FINCH
LONG TERM...TJT
AVIATION...TJT
FIRE WEATHER...FINCH
AREA FORECAST DISCUSSION
NWS RENO NV
308 PM PDT SAT MAR 29 2014
.SYNOPSIS...
RAIN AND SNOW WILL CONTINUE THROUGH TONIGHT AS A LATE SEASON
WINTER STORM MOVES ACROSS THE SIERRA. A COLDER STORM SYSTEM WILL
IMPACT THE REGION MONDAY AND TUESDAY WITH LIGHT SNOW POSSIBLE IN
LOWER ELEVATIONS. BELOW NORMAL TEMPERATURES ARE EXPECTED THROUGH
MUCH OF THE UPCOMING WEEK, WITH ANOTHER CHANCE OF RAIN AND SNOW
SHOWERS THURSDAY AND FRIDAY.
&&
.SHORT TERM...
PRECIPITATION CONTINUES TO INTENSIFY NEAR AND WEST OF THE SIERRA
CREST AS MAIN TROUGH APPROACHES THE CALIFORNIA COAST. UPPER LEVEL
JET WILL ALSO MOVE ONSHORE AND ENHANCE THE MOISTURE BAND. SNOW
LEVELS EAST OF THE SIERRA CREST NEAR TAHOE HAVE REMAINED NEAR
6500-7000 FEET BUT SHOULD DROP TO LAKE LEVEL BEFORE 5 PM. SNOWFALL
RATES OF 1-2 INCHES PER HOUR ARE LIKELY TO PERSIST A PERIOD OF 6-8
HOURS, AND TRAVEL IMPACTS WILL INCREASE THIS EVENING AS SNOW
BEGINS ACCUMULATING ON PAVED SURFACES. THEREFORE THE WARNING WILL
REMAIN IN PLACE. FARTHER NORTH INTO LASSEN COUNTY, ALTHOUGH SOME
SNOW HAS ALREADY ACCUMULATED ABOVE 5500 FEET, THE HEAVIER SNOW IS
ALSO EXPECTED TO END SOONER, SO THE ADVISORY SHOULD BE SUFFICIENT.
LOCALIZED SNOW SHOWER BANDS MAY CONTINUE LATER TONIGHT, DEPENDING
ON HOW MUCH CONVECTIVE ACTIVITY DEVELOPS IN NORTH CENTRAL CA
DURING THE NEXT FEW HOURS.
FOR MONO COUNTY, SNOW WILL INCREASE THIS EVENING, SPREADING
SOUTHWARD ALONG THE SIERRA AND PROBABLY REACHING THE MAMMOTH
LAKES VICINITY BY 8 PM. BEFORE THE SNOW ARRIVES, WINDY CONDITIONS
WILL CONTINUE, SO THE ADVISORY WILL BE EXTENDED FOR A FEW MORE
HOURS. SINCE ALL OF THE SNOW WILL FALL IN A COMPRESSED TIME
PERIOD AND THE BAND WILL BEGIN TO WEAKEN LATE TONIGHT, SNOW TOTALS
NEAR THE CREST MAY TOP OUT CLOSER TO 16 INCHES INSTEAD OF THE
ORIGINAL 20 INCH PROJECTION. HOWEVER, IMPACTS WILL STILL BE
SUFFICIENT TO KEEP THE WARNING IN PLACE TONIGHT.
FOR WESTERN NV, THE RAIN SHADOW HAS PERSISTED SO FAR THIS
AFTERNOON. HOWEVER, THE LAST FEW RUNS OF THE HRRR MODEL HAVE
INDICATED RAPID SPILLOVER INTO THE RENO-CARSON VICINITY BETWEEN 4
AND 5 PM, WITH UP TO 6 HOURS OF NEARLY STEADY RAIN THROUGH THIS
EVENING. IF THIS OCCURS, RAINFALL COULD STILL ADD UP TO BETWEEN
0.25 AND 0.50 INCH, WITH LOCALLY HIGHER AMOUNTS IN FOOTHILL
LOCATIONS. FOR AREAS SOUTH OF HIGHWAY 50, THE MAJORITY OF THE RAIN
WILL FALL DURING THE LATE EVENING AND OVERNIGHT HOURS. THE PRECIP
COULD END AS SNOW BELOW 5000 FEET, BUT LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED IN VALLEYS. ABOVE 5000 FEET, A COUPLE
INCHES MAY ACCUMULATE, BUT SOME LOCALLY HIGHER AMOUNTS MAY FALL IN
DOUGLAS COUNTY AS THE COLD AIR ARRIVES IN CONJUNCTION WITH THE
ONGOING HEAVIER PRECIP BAND. THIS OCCURRED WITH ONE OF THE STORMS
EARLIER THIS SEASON SO THIS WOULD NEED TO BE MONITORED LATER
TONIGHT.
ALL GUIDANCE IS IN AGREEMENT FOR A RAPID DISSIPATION OF THE RAIN
AND SNOW BY EARLY SUNDAY MORNING. FOR SUNDAY, A FEW SHOWERS MAY
LINGER NEAR THE SIERRA AND IN WEST CENTRAL NV EAST OF HIGHWAY 95,
OTHERWISE MOSTLY CLOUDY AND DRY CONDITIONS WILL PREVAIL WITH
MODERATE WEST WINDS GUSTING TO 20-30 MPH IN THE AFTERNOON. MJD
A COLDER LOW PRESSURE WILL DROP ALONG THE WEST COAST EARLY NEXT
WEEK, BRINGING ADDITIONAL PRECIPITATION TO THE SIERRA AND WESTERN
NEVADA. THIS LOW WILL BRING VERY COLD AIR DOWN FROM THE GULF OF
ALASKA WITH 700MB NEAR -10C. SNOW LEVELS WILL FALL TO MOST VALLEY
FLOORS BY MONDAY NIGHT AND INTO TUESDAY MORNING.
THAT BEING SAID, THE LATEST MODEL RUNS OF THE GFS AND ECMWF HAVE
BACKED OFF ON PRECIPITATION AMOUNTS IN WESTERN NEVADA, LEADING TO
CONTINUED UNCERTAINTY AND LOW FORECASTER CONFIDENCE. THIS IS MAINLY
BECAUSE THE LOW IS TRYING TO SPLIT OFF TO THE SOUTH AND DRIVE THE
JET AND DYNAMICS WELL INTO SOUTHERN CA.
THE HIGHEST CHANCES FOR SNOW WILL REMAIN IN THE SIERRA LATE MONDAY
AS THE FIRST SHORTWAVE MOVES THROUGH NORTHERN CA. THE 500MB
SHORTWAVE LOOKS TO BECOME NEGATIVELY TILTED, WHICH IS IS NOT
NECESSARILY GOOD FOR SPILLOVER. BUT, WE SHOULD BE UNSTABLE ENOUGH
FOR SOME LIGHT SPILLOVER IF THE JET REMAINS SOUTH OF MONO COUNTY.
BY TUESDAY, LOW PRESSURE REMAINS OVER THE REGION WITH CONVECTIVE
SHOWERS DEVELOPING UNDER THE COLD POOL. INSTABILITY LOOKS FAIRLY
STRONG DUE TO THE INCREASED SOLAR HEATING. WE WILL NEED TO KEEP A
CLOSE EYE, BECAUSE A SURFACE LOW DEVELOPING OVER SOUTHERN NEVADA MAY
CREATE SOME LOW-LEVEL FORCING THAT COULD INCREASE PRECIPITATION
RATES IN THE EASTERN SIERRA AND WESTERN NEVADA. HOON
.LONG TERM...WEDNESDAY THROUGH SATURDAY...
FORECAST REMAINS UNCERTAIN FOR THE SYSTEM AT THE END OF NEXT WEEK.
DETERMINISTIC SOLUTIONS HAVE LARGELY DIVERGED WITH THE GFS
PRESENTING A SPLIT SYSTEM WILL VERY LITTLE PRECIPITATION; THE EC
SHOWS A MORE CONSOLIDATED FRONT WITH LOW PRESSURE IN CENTRAL OREGON
AND DECENT PRECIP ALONG THE SIERRA. THEREFORE, VERY FEW ADJUSTMENTS
TO THE EXISTING FORECAST FAVORING A BLENDED APPROACH WITH 30-40%
CHANCE OF PRECIP ALONG THE SIERRA FROM THURSDAY INTO SATURDAY.
TEMPERATURES CONTINUE TO LOOK AROUND TO SLIGHTLY COOLER THAN
SEASONAL AVERAGES WITH MODEST COLD AIR ALOFT AT 700MB AND AMPLE
CLOUD COVER. HOPEFULLY SOLUTIONS WILL BEGIN TO CONVERGE OVER THE
NEXT DAY OR SO TO ALLOW FOR HIGHER DETAILS. BOYD
&&
.AVIATION...
A CHANGEOVER TO SNOW IS EXPECTED BY 00Z AROUND THE TAHOE BASIN,
WITH ABOUT 6-8 HOURS OF CIGS/VSBY BELOW LANDING MINIMUMS AT
KTVL/KTRK THIS EVENING AND INTO THE LATE NIGHT. FOR KMMH, THE
WORST CONDITIONS ARE LIKELY FROM 03Z-12Z FROM THIS SAME SNOW BAND.
CONDITIONS WILL IMPROVE SUNDAY MORNING ALTHOUGH SOME MVFR CIGS
COULD LINGER THROUGH MUCH OF THE DAY AS RESIDUAL MOISTURE REMAINS
IN PLACE.
FOR WESTERN NV INCLUDING KRNO-KCXP, RAIN WILL INCREASE AROUND 00Z,
PRODUCING MVFR CIGS/VSBY AT TIMES FOR 4-6 HOURS THIS EVENING. THIS
PRECIP MAY BRIEFLY END AS SNOW, BUT LITTLE OR NO SNOW ACCUMULATION
IS EXPECTED ON RUNWAYS. VFR CONDITIONS ARE EXPECTED SUNDAY
ALTHOUGH SOME MOUNTAIN OBSCURATIONS WILL REMAIN POSSIBLE DUE TO
RESIDUAL CLOUD COVER. MJD
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY NVZ002.
LAKE WIND ADVISORY UNTIL 8 PM PDT THIS EVENING FOR PYRAMID LAKE
IN NVZ004.
CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT SUNDAY ABOVE 5500 FEET
FOR CAZ071.
WIND ADVISORY UNTIL 8 PM PDT THIS EVENING CAZ073.
WINTER STORM WARNING FROM 8 PM THIS EVENING TO 5 AM PDT SUNDAY
CAZ073.
WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
1112 AM PDT SAT MAR 29 2014
.UPDATE...
WE EXTENDED THE WIND ADVISORY FOR THE RENO ZONE THRU 3 PM. GUSTS
TO 50 MPH WERE RECENTLY REPORTED AT THE RENO AIRPORT AND PORTIONS
OF WASHOE VALLEY. SOME BLOWING DUST WAS STILL OBSERVED OUTSIDE THE
WINDOW NEAR THE EAST END OF THE CITY. LATEST HRRR GUIDANCE SHOWS A
FEW MORE HOURS OF SHADOWING BEFORE RAIN SPILLS OVER INTO RENO-
CARSON CITY, SO LOCALLY STRONG GUSTS SHOULD CONTINUE UNTIL THEN.
REMAINDER OF FORECAST STILL ON TRACK WITH NO OTHER CHANGES TO
HEADLINES. SNOW LEVELS AROUND 6500 FEET WEST OF TAHOE SHOULD DROP
TO LAKE LEVEL BY MID AFTERNOON. MJD
&&
.PREVIOUS DISCUSSION... /ISSUED 327 AM PDT SAT MAR 29 2014/
SYNOPSIS...
A LATE SEASON WINTER STORM WILL BRING HEAVY SNOW IN THE SIERRA AND
RAIN FOR LOWER ELEVATIONS THROUGH TONIGHT. A COLDER STORM SYSTEM WILL
IMPACT THE REGION NEXT MONDAY AND TUESDAY WITH LIGHT SNOW POSSIBLE
IN LOWER ELEVATIONS. BELOW NORMAL TEMPERATURES ARE EXPECTED
THROUGH MUCH OF THE UPCOMING WEEK, WITH LIGHT RAIN AND SNOW
SHOWERS POSSIBLE AGAIN LATE NEXT WEEK.
SHORT TERM...
PRECIPITATION CONTINUES ITS SLOW PROGRESSION ACROSS NORTHERN
CALIFORNIA MAINLY NORTH OF I-80. AREA WEBCAMS SHOWING SNOW BEGINNING
TO MIX WITH RAIN AT BOGARD IN WESTERN LASSEN COUNTY WITH SURFACE
TEMPERATURES A FEW DEGREES ABOVE FREEZING. THIS PRECIP WILL CONTINUE
TO WORK ITS WAY SOUTH ACROSS THE SIERRA TODAY WITH PERIODS OF
HEAVY SNOWFALL EXPECTED THIS AFTERNOON ACROSS THE SIERRA IN THE
TAHOE BASIN AND THIS EVENING IN MONO COUNTY.
GUSTY WINDS HAVE DEVELOPED AHEAD OF THE PRECIPITATION WITH SOME OF THE
WIND PRONE AREAS ALREADY GUSTING INTO THE 60-70 MPH RANGE. OUTSIDE
OF THE WIND PRONE REGIONS WIND GUSTS HAVE BEEN GENERALLY IN THE
20-30 MPH RANGE. 700MB FLOW WILL PEAK THIS MORNING WITH THE
SURFACE GRADIENT INCREASING AS THE SURFACE LOW DEEPENS. AS SUCH,
WILL ISSUE A WIND ADVISORY COVERING AREAS IN THE LEE OF THE SIERRA
WHICH WILL INCLUDE THE RENO/CARSON/GARDNERVILLE REGION ALONG WITH
MONO COUNTY. WIND GUSTS OF 50 MPH ARE POSSIBLE ACROSS VALLEY AREAS
WITH WIND PRONE AREAS CONTINUING IN THE 60-70 MPH RANGE. HAZARDOUS
BOATING CONDITIONS ARE ALSO EXPECTED ACROSS AREAS LAKES. WINDS
WILL DIMINISH THIS AFTERNOON WITH THE ARRIVAL OF THE PRECIPITATION
AND FRONT.
HEAVY SNOWFALL WILL IMPACT AREAS ABOVE 7000 FEET THIS MORNING BEFORE
SNOW LEVELS STEADILY DROP THROUGH THE DAY AS COLDER AIR ALOFT
FILTERS INTO THE REGION. THIS SYSTEM WILL FEATURE DYNAMIC SUPPORT
VIA A COUPLED JET AND FRONTOGENETICAL FORCING WHICH WILL PROVIDE
PERIODS OF HEAVY SNOWFALL ABOVE 7000 FEET ALLOWING FOR SNOWFALL
RATES HEAVY ENOUGH TO ACCUMULATE ON ROADWAYS RESULTING IN TRAVEL
IMPACTS ACROSS PASSES. SNOW LEVELS LOOK TO FALL TO LAKE LEVEL
DURING THE AFTERNOON SOMEWHERE BETWEEN 3-6PM. PERIODS OF
CHANGEOVER TO SNOW ARE POSSIBLE EARLIER WITHIN HEAVIER BANDS OF
PRECIP. ALL TOLD SNOWFALL TOTALS THROUGH SUNDAY MORNING COULD SEE
UPWARDS OF 2 FEET ACROSS THE CREST WITH GENERALLY ABOUT 6-12"
POSSIBLE BELOW 7000 FEET, HIGHEST ALONG THE WESTERN SIDE OF THE
BASIN. SPILLOVER IS LIKELY INTO WESTERN NEVADA LATE SATURDAY
AFTERNOON INTO EARLY EVENING WITH THE PRESENCE OF DYNAMIC FORCING.
A QUARTER TO A THIRD OF AN INCH OF RAINFALL IS POSSIBLE WITH THE
FRONT WITH SNOWFALL POSSIBLE IN THE FOOTHILLS AS SNOW LEVELS
QUICKLY FALL TO NEAR 5000 FEET WITH THE FRONT. TIMING ACROSS MONO
COUNTY FOR THE HEAVIEST PRECIPITATION STILL LOOKS TO BE THIS
EVENING AND TONIGHT AS THE COUPLED JET SYSTEM TRACKS SOUTH.
SNOWFALL ACCUMULATIONS OF 1.5-2 FEET STILL POSSIBLE ACROSS THE
CREST IN MONO COUNTY WITH HIGHER AMOUNTS ACROSS THE NORTHERN HALF
OF THE COUNTY.
SHOWERS TAPER OFF SUNDAY MORNING WITH A BREAK BETWEEN SYSTEMS
THROUGH EARLY MONDAY AS A COLDER SYSTEM IS POISED TO PROVIDE
ANOTHER ROUND OF SNOWFALL TO THE SIERRA WITH SNOW LEVELS LOW
ENOUGH TO EVEN PROVIDE SNOW TO THE VALLEY AREAS ACROSS WESTERN
NEVADA BY MONDAY NIGHT. THOUGH THE BEST JET DYNAMICS LOOK TO
REMAIN SOUTH OF THE REGION, THE COLDER AIRMASS SHOULD PROVIDE FOR
HIGHER RATIO SNOWFALLS WITH AN ADDITIONAL FOOT OF SNOWFALL
POSSIBLE ACROSS THE SIERRA AND LIGHT ACCUMULATIONS POSSIBLE DOWN
AT THE VALLEY FLOORS IN WESTERN NEVADA. FUENTES
LONG TERM...TUESDAY THROUGH FRIDAY...
MADE FEW CHANGES TO THE LONG TERM FORECAST, BUT UNCERTAINTY IS A BIT
HIGHER THIS MORNING THAN 24 HOURS AGO. MODELS ARE STRUGGLING A BIT
MORE WITH THE SPLITTING OF THE UPPER LOW TUESDAY AS IT COMES IN AS
WELL AS THE NEXT SYSTEM FOR LATE IN THE WEEK.
THE UPPER LOW IS NOW FORECAST BY THE MODELS TO DROP WEST OF THE AREA
WITH MORE OF A SPLIT ON TUESDAY. DESPITE THIS OCCURRING, THERE WILL
STILL BE PLENTY OF COLD AIR ALOFT FOR SOME SHOWERS TUESDAY ALL
ACROSS THE SIERRA AND WESTERN NEVADA. THERE COULD ALSO BE A
THUNDERSTORM OR TWO, BUT WILL LEAVE THAT OUT FOR NOW AS IT STILL
LOOKS MARGINAL.
SLOW DRYING TUESDAY NIGHT AS THE LOW PULLS AWAY. WEDNESDAY LOOKS
MOSTLY DRY RIGHT NOW, BUT THE EC AND A COUPLE GFS ENSEMBLE MEMBERS
SHOW ENOUGH COLD AIR AND MOISTURE ALOFT REMAIN FOR A COUPLE SHOWERS.
WILL HAVE TO KEEP AN EYE ON THAT. FOR THE NEXT SYSTEM LATE IN THE
WEEK, THE MODELS SHOW WIDELY VARYING SOLUTIONS. THE EC BRINGS IN
ANOTHER UPPER LOW SLOWLY WHILE THE GFS KEEPS AN OPEN WAVE WITH THE
JET STREAM REMAINING NORTH INTO OREGON. HAVE NOT CHANGED ANYTHING
YET AS IT STILL LOOKS TO BE SOMEWHAT WET AND SLIGHT CHC TO CHC POPS
LOOK GOOD FOR NOW.
WITH THE UPPER LOW AND SYSTEMS MOVING THROUGH, EXPECT TEMPS TO
REMAIN A BIT BELOW AVERAGE FOR THE WEEK WITH TUESDAY BEING THE
COLDEST DAY. OVERNIGHT LOWS WILL BE CLOSER TO NORMAL DUE TO THE
MOISTURE AND CLOUD COVER. WALLMANN
AVIATION...
BAND OF MODERATE/HEAVY RAIN AND SNOW IS NOW MOVING INTO THE SIERRA
NORTH OF LAKE TAHOE. THIS BAND WILL SLOWLY SHIFT SOUTH DURING THE
DAY AND PUSH THROUGH MONO COUNTY BY THIS TIME TOMORROW.
FOR THE SIERRA TERMINALS: EXPECT MOSTLY RAIN THROUGH MID-AFTERNOON
WITH SNOW LEVELS NEAR 7000 FEET AT KTRK/KTVL. CIGS/VIS TO REMAIN
MVFR TO OCNL IFR THRU 22Z AND THERE COULD BE SOME ICING ISSUES
ALOFT. TRANSITION TO SNOW BETWEEN 22-00Z WITH 70% CONFIDENCE WITH
HEAVY SNOW THEREAFTER THROUGH 06Z BLO KTRK/KTVL MINIMUMS. RUNWAY
ACCUM AROUND 6 INCHES. IMPROVING CONDS THEREAFTER.
FOR KMMH, SOME GUSTY WINDS TO 40 KTS THROUGH 22Z WITH SIGNIFICANT
TURBULENCE BEFORE -RA BEGINS AFTER 00Z. CHANGES TO SNOW 03-06Z WITH
IFR CONDS AND 2-4 INCHES RUNWAY ACCUMULATION WITH CONFIDENCE 60-70%.
KRNO/KCXP: GUSTY WINDS TO 35 KTS THIS MORNING WITH MTN WAVE
TURBULENCE AND LIMITED LLWS THROUGH 18Z. AS BAND SHIFTS SOUTH, MORE
FAVORABLE FOR SPILLOVER SO EXPECT WINDS TO DIMINISH TO LESS THAN 20
KTS. WITH MVFR CIGS/VIS IN RA 20-03Z AND 70% CONFIDENCE. -RA WILL
CHANGE TO -SN AS IT ENDS AROUND 03Z, BUT NO RUNWAY ACCUMULATION.
EXPECT VFR CONDS THEREAFTER WITH AN OCCASIONAL STRAY -SHSN
OVERNIGHT. WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY NVZ002.
WIND ADVISORY UNTIL 3 PM PDT THIS AFTERNOON NVZ003.
LAKE WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON FOR PYRAMID
LAKE IN NVZ004.
CA...WINTER WEATHER ADVISORY UNTIL 5 AM PDT SUNDAY ABOVE 5500 FEET
FOR CAZ071.
WIND ADVISORY UNTIL 5 PM PDT THIS AFTERNOON CAZ073.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM PDT SUNDAY
CAZ073.
WINTER STORM WARNING UNTIL 5 AM PDT SUNDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS ALBANY NY
416 PM EDT SAT MAR 29 2014
.SYNOPSIS...
AN EARLY SPRING STORM WILL BRING MODERATE TO HEAVY PRECIPITATION
ACROSS THE REGION FOR THE REMAINDER OF THIS WEEKEND. TEMPERATURES
WILL BECOME QUITE DIVERSE WITH THE COOLER VALUES EXPECTED ACROSS
THE HIGHER TERRAIN. IN FACT...THESE COOLER TEMPERATURES WILL RESULT A
WINTRY MIXTURE OF PRECIPITATION TO EVOLVE WITH SOME ACCUMULATIONS
ANTICIPATED.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 330 PM EDT...A FEW BREAKS OF SUNSHINE RESULTED IN HIGHER
THAN EXPECTED TEMPERATURES THIS AFTERNOON WITH MOST VALLEY
LOCATIONS AROUND 50F AND EVEN INTO THE TERRAIN OF THE BERKS AND
SOUTHERN GREENS WHERE LOWER 50S HAVE BEEN OBSERVED. REGIONAL
RADAR MOSAIC REVEALS THE LEADING EDGE OF THE RAIN SHIELD WAS
APPROACHING THE MASS PIKE WITH SOLID AREA OF RAIN ALONG THE I84
CORRIDOR AND ALL OF LITCHFIELD COUNTY. THIS AREA OF RAIN WILL
EXPAND AND INCREASE FROM SOUTH TO NORTH THROUGH THIS EVENING PER
THE LATEST HRRR REFLECTIVITY FORECASTS. WITH RATHER MILD
TEMPERATURES...MOST OF THE INITIAL ONSET OF PRECIP SHOULD BE IN
THE FORM OF RAIN ACROSS THE ADIRONDACKS.
THE LOW LEVEL AGEOSTROPHIC FLOW FROM THE NORTH INCREASES
OVERNIGHT. LOOKING UPSTREAM THE TEMPS WERE INTO THE MID 30S WITH
DEWPOINTS INTO THE MID 20S. SO NOT THAT COLD OF AN AIRMASS BUT WET
BULB PROCESS COULD SEE A MIXTURE OF RAIN/SLEET/FREEZING RAIN AS WE
WILL HOLD ONTO THE WINTER WEATHER ADVISORIES AT THIS TIME. CHANCES
FOR WINTRY TYPE PRECIPITATION APPEARS TO BE DIMINISHING ACROSS THE
GLENS FALLS REGION AS ADDITIONAL SHIFTS IN THE HEADLINES ARE
POSSIBLE IF THE TRENDS CONTINUE TO WARM.
AS FOR RAINFALL...IMPRESSIVE ISENTROPIC LIFT...H850-700 FGEN
FIELDS INCREASING...PWAT ANOMOLIES REMAIN 1-3 STANDARD DEVIATIONS
ABOVE NORMAL AND INCREASING LOW LEVEL SOUTHEAST JET ALL POINT
TOWARD MODERATE TO HEAVY RAIN. PER CSTAR RESEARCH...THE SYNOPTIC
PATTERN RESEMBLES THAT OF A HP NEUTRAL CUT OFF UPPER LOW WHICH IS
HIGHLY SUSCEPTIBLE FOR FLOODING ACROSS OUR SERVICE AREA. WE WILL
RETAIN THE FLOOD WATCH AS THE COMBINATION OF RUN OFF /NEARLY
FROZEN GROUND DESPITE THE FIRST COUPLE OF INCHES LIKELY DEFROSTED
AT THIS TIME/ AND POTENTIAL FROM ICE JAMS WILL BE ON THE INCREASE.
SEE THE HYDROLOGY DISCUSSION BELOW FOR FURTHER DETAILS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
SUNDAY...THE SURFACE LOW OVER THE CENTRAL APPALACHIANS WILL
BECOME NEARLY VERTICALLY STACKED OVER THE DELMARVA REGION SUNDAY
MORNING. MID LEVEL DRY SLOT IS EXPECTED TO RACE NORTHWARD WHICH
WILL LIKELY DIMINISH THE INTENSITY OF THE PRECIPITATION ACROSS THE
REGION FROM SOUTH TO NORTH. POCKETS OF DRIZZLE/LIGHT RAIN AND SOME
LIGHT WINTRY MIX ACROSS THE DACKS ARE EXPECTED. GLOBAL MODEL
TRENDS ARE FAVORING A NORTHEAST TO SOUTHWEST ORIENTED BAND OF
ENHANCED PRECIP TO DEVELOP SOMEWHERE OVER THE WESTERN
DACKS...WESTERN MOHAWK VALLEY AND CATSKILLS THROUGH THE AFTERNOON
AS THIS LOW SLOWLY MOVES OFF THE MID ATLANTIC COAST. ADDITIONAL
PRECIPITATION WILL DEVELOP WITH PARTIAL THICKNESS SCHEME FROM THE
GFS/ECMWF POINTING TOWARD A MIXTURE ACROSS THE HIGHER TERRAIN WEST
OF THE HUDSON RIVER.
SUNDAY NIGHT...CONSENSUS IS NOW FAVORING A RATHER IMPRESSIVE
DEFORMATION AXIS OF PRECIP TO EVOLVE AND IMPACT THE CENTRAL PART
OF OUR REGION FROM SOUTHERN VT...CAPITAL DISTRICT...EASTERN MOHAWK
VALLEY AND CATSKILL REGION. EQUALLY AS CHALLENGING WILL BE THE
THERMAL PROFILES AS CROSS SECTIONS SUGGEST THE BOUNDARY LAYER WILL
COOL OFF TO ALLOW FOR THE PRECIP TO MIX WITH SLEET AND/OR FREEZING
RAIN FOR MOST OF THE REGION. THIS EVENT PERIOD WILL NEED TO
MONITORED VERY CLOSELY WITH ADDITIONAL WINTER WEATHER HEADLINES
POSSIBLE.
MONDAY...GLOBAL MODEL CONSENSUS IS NOW FAVORING THE DEFORMATION
AXIS TO SLIDE EAST OF THE HUDSON IN THE MORNING AND CLEARING OUR
WESTERN NEW ENGLAND COUNTIES BY MID AFTERNOON. THERMAL PROFILES
POINT TOWARD A WINTRY MIXTURE / SNOW IN THE MORNING...THEN WITH
WARMING BOUNDARY LAYER TEMPERATURES WE WILL GRADUALLY MIX WITH
SOME RAIN BEFORE ENDING. AS NORTHERLY WINDS DOWN THE HUDSON
INCREASE AND MIXING LAYER HEIGHTS CLIMBING TO AROUND H900...MID
20-MID 30 KTS OF WIND COULD MIX DOWN.
AS FOR MOS GUIDANCE...WE WILL FAVOR CLOSER VALUES TO THE
MAV/ECMWF.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
RIDGING ALOFT WILL BUILD INTO THE REGION FOR MONDAY NIGHT AND
CONTINUE THROUGH THE MID WEEK PERIOD. THIS WILL ALLOW FOR
TEMPERATURES TO RETURN TO NEAR SEASONABLE LEVELS...WITH MAINLY DRY
CONDITIONS. MIN TEMPS ON MON NIGHT WILL BE IN THE 20S TO LOW 30S.
MAX TEMPS ON TUESDAY WILL BE IN THE 50S /SOME UPPER 40S OVER THE
HIGH TERRAIN/ WITH PLENTY OF SUNSHINE.
THERE IS SOME UNCERTAINTY IN WHETHER A SYSTEM MOVING ACROSS THE
UPPER GREAT LAKES CAN BRING SOME PRECIP TO THE REGION FOR TUESDAY
NIGHT INTO WEDNESDAY. WHILE THE 12Z ECMWF SHOWS THE UPPER LEVEL
RIDGE HOLDING IN AND KEEPING IT DRY...THE 12Z GFS IMPLIES THAT THE
SYSTEM CAN BREAK DOWN THE RIDGE ENOUGH TO BRING A COLD FRONT THROUGH
THE AREA...WITH SOME LIGHT RAIN AND SNOW SHOWERS /MAINLY FOR THE
HIGH TERRAIN/. FOR NOW...WILL GO WITH A SLIGHT TO LOW CHC POPS FOR
RAIN/SNOW SHOWERS...AND ONLY ALLOW FOR SNOW SHOWERS ACROSS THE HIGH
TERRAIN AND AT NIGHT. MIN TEMPS ON TUESDAY NIGHT WILL BE IN THE
30S...AND MAX TEMPS ON WEDNESDAY WILL REACH THE MID 40S TO MID 50S.
DRY WEATHER LOOKS TO RETURN FOR WED NIGHT INTO EARLY THURSDAY.
HOWEVER...THIS LOOKS BRIEF...AS A SERIES OF SYSTEMS MOVING ACROSS
THE OHIO VALLEY WILL APPROACH THE REGION FOR THE LATE WEEK PERIOD.
SOME PRECIP MAY OCCUR ON THURSDAY NIGHT...AND THEN AGAIN LATER ON
FRIDAY AND INTO SATURDAY. NORTHERN OR HIGH TERRAIN AREAS MAY SEE
SOME SNOW AT THE ONSET OF THE PRECIP...OTHERWISE P-TYPE WILL BE
RAIN...AS TEMPS LOOKS SEASONABLE FOR THIS TIME OF YEAR...ALONG WITH
PLENTY OF CLOUDS. MIN TEMPS FOR THURS/FRI NIGHTS WILL BE IN THE 30S
AND MAX TEMPS WILL BE IN THE 40S AND 50S FOR FRI AND SAT.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
A SLOW MOVING STORM SYSTEM OVER THE MID ATLANTIC REGION WILL
SLOWLY MOVE UP THE NORTHEAST COAST OVER THE REMAINDER OF THE
WEEKEND. FLYING CONDITIONS ARE CURRENTLY VFR FOR THE VALLEY
SITES...WITH HIGH END MVFR AT KPSF DUE TO LINGERING LOW LEVEL
MOISTURE KEEPS LOWER CIGS IN PLACE.
RAIN IS CURRENTLY JUST ABOUT TO REACH KPOU...AND WILL CONTINUE TO
SLOWLY ADVANCE NORTHWARD THROUGH THE AFTN AND EVENING HOURS.
SHORTLY AFTER THE RAIN BEGINS...FLYING CONDITIONS FOR BOTH
VSBYS/CIGS WILL LOWER TO MVFR. BY THE EVENING HOURS...THE RAIN
WILL PICK UP IN INTENSITY...WHICH WILL LOWER CIGS/VSBYS TO IFR
LEVELS FOR MUCH OF THE OVERNIGHT HOURS.
THE RAIN WILL START TO DECREASE IN INTENSITY/COVERAGE TOWARDS
DAYBREAK...ALLOWING VSBYS TO RETURN TO 4-6 SM...WITH JUST SOME
AREAS OF LIGHT RAIN CONTINUING INTO THE DAY ON SUNDAY. CIGS MAY
CONTINUE TO REMAIN IFR FOR A BIT INTO EARLY IN THE DAY ON SUNDAY /ESP
AT KPSF/...BUT LOOK TO IMPROVE BACK TO MVFR SOMETIME DURING THE
MORNING HOURS.
WINDS WILL BECOME N-NE AND INCREASE TO AROUND 10-15 KTS FOR ALL
SITES. THERE MAY BE A FEW HIGHER GUSTS OVERNIGHT AT KALB...AS AIR
IS FUNNELED DOWN THE HUDSON VALLEY. N-NW WINDS AROUND 10 KTS LOOK
TO CONTINUE RIGHT INTO THE DAY ON SUNDAY.
OUTLOOK...
SUN NIGHT: HIGH OPERATIONAL IMPACT. BREEZY. LIKELY RA...FZRA...SLEET.
MON:
MODERATE OPERATIONAL IMPACT. BREEZY. CHANCE OF RA...FZRA.
MON NIGHT-TUE: NO OPERATIONAL IMPACT. NO SIG WX.
TUE NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.
WED: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
NO FIRE WEATHER PROBLEMS ARE EXPECTED THE NEXT SEVERAL DAYS. WET WEATHER
IS LIKELY FOR THE ENTIRE WEEKEND INTO MONDAY DUE TO THE COASTAL
SYSTEM. SOME WINTRY PRECIPITATION WILL ALSO OCCUR NORTH OF THE
CAPITAL REGION TONIGHT INTO SUNDAY. THE WINTRY PRECIPITATION COULD
IMPACT MOST OF THE REGION SUNDAY NIGHT INTO MONDAY AS COLDER AIR
FILTERS BACK INTO THE AREA.
&&
.HYDROLOGY...
A FLOOD WATCH REMAINS IN EFFECT OUTSIDE OF THE ADIRONDACK REGION
STARTING AT 8 PM TONIGHT UNTIL MONDAY MORNING. THE POTENTIAL
EXISTS FOR MINOR FLOODING FROM MODERATE TO HEAVY RAINFALL COMBINED
WITH SNOWMELT. IN ADDITION...ICE BREAK UP AND ICE JAM FLOODING IS ALSO
POSSIBLE.
A SIGNIFICANT STORM SYSTEM WILL MOVE FROM THE MID ATLANTIC COAST
TOWARDS LONG ISLAND TONIGHT INTO SUNDAY. THIS SYSTEM HAS THE
POTENTIAL TO BRING MODERATE TO HEAVY AMOUNTS OF PRECIPITATION TO
THE REGION...ESPECIALLY FOR AREAS FROM THE CAPITAL REGION SOUTH
AND EAST...WITH A GENERAL CONSENSUS FROM THE GUIDANCE SHOWING ONE
TO THREE INCHES OF RAINFALL ACROSS THE REGION. WHILE MUCH OF THIS
WILL BE IN THE FORM OF RAINFALL...THERE IS THE POTENTIAL FOR THE
PRECIP TO CHANGE TO A WINTRY MIX OR SNOWFALL BEFORE ENDING ACROSS
THE REGION.
CURRENT NERFC RIVER FORECASTS SHOW RISING LEVELS TO NEAR OR ABOVE
FLOOD STAGE. THERE IS THE POTENTIAL FOR SIGNIFICANT
RISES...ESPECIALLY ACROSS THE HOUSATONIC...HOOSIC...RONDOUT CREEK
WILLIAMS RIVER AND METTAWEE BASINS. ALTHOUGH QPF AMOUNTS ARE NOW
FORECAST TO RANGE BETWEEN 1 AND 2 WITH AMOUNTS UP TO 3 INCHES
SOUTH OF THE CAPITAL REGION...THE CHALLENGE IS ICE BREAKING UP ON
LARGER MAIN STEM RIVERS AS WELL...WHICH COULD POTENTIALLY CAUSE
ICE JAMS IN SOME LOCATIONS. WITH THE BULK OF THE RAINFALL EXPECTED
TO OCCUR TONIGHT INTO SUNDAY MORNING IN A RELATIVELY SHORT PERIOD
OF TIME...SOME MINOR URBAN...LOW LYING...AND SMALL STREAM FLOODING
COULD POTENTIALLY OCCUR AS WELL. THE MOST LIKELY AREAS TO SEE
ISSUES WOULD BE FROM THE MOHAWK BASIN SOUTH AND EAST.
DRIER WEATHER LOOKS TO RETURN FOR MONDAY NIGHT THROUGH WEDNESDAY
OF NEXT WEEK...ALLOWING RIVERS AND STREAMS TO SLOWLY RECEDE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.CLIMATE...
HOW COLD HAS MARCH 2014 BEEN? THROUGH THE 28TH THE AVERAGE
MONTHLY TEMPERATURE HAS BEEN 26.4 DEGREES WHICH IS 8.1 DEGREES
BELOW NORMAL. ONLY 5 DAYS THIS MONTH AS THE AVERAGE DAILY
TEMPERATURE BEEN ABOVE NORMAL.
TOP 10 COLDEST MARCHES - ALBANY NY - RECORDS DATE BACK TO 1820.
1) 23.6 DEGREES 1885
2) 24.6 DEGREES 1863
3) 24.7 DEGREES 1875
4) 25.3 DEGREES 1843
5) 26.0 DEGREES 1888
6) 26.1 DEGREES 1916
7) 26.2 DEGREES 1869
8) 26.5 DEGREES 1960
9) 26.8 DEGREES 1940
10) 27.0 DEGREES 1836
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR CTZ001-013.
NY...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR NYZ038>041-043-047>054-058>061-063>066-082>084.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO NOON EDT
SUNDAY FOR NYZ032-033-042.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EDT
SUNDAY FOR NYZ043-083.
MA...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR MAZ001-025.
VT...FLOOD WATCH FROM 8 PM EDT THIS EVENING THROUGH MONDAY MORNING
FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...BGM/WASULA
HYDROLOGY...BGM/WASULA
CLIMATE...NWS STAFF
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION...UPDATED
NWS MIAMI FL
134 PM EDT SAT MAR 29 2014
.AVIATION...
A LINE OF THUNDERSTORMS OVER CENTRAL FLORIDA WILL CONTINUE TO
MOVE SOUTHEAST AND INTO SOUTH FLORIDA LATE THIS AFTERNOON INTO
THIS EVENING. THE TIMING OF THE SHOWERS AND THUNDERSTORMS SHOULD
AFFECT KPBI AND KAPF TAF SITES BETWEEN 23Z AND 01Z...KFXE AND KFLL
BETWEEN 00Z AND 02Z...AND REST OF THE TAF SITES BETWEEN 01Z AND
O3Z. SO HAVE DELAY THE VCTS UNTIL THE ABOVE TIMES FOR THE MENTION
TAF SITES. THERE COULD ALSO BE SOME SHOWERS AHEAD AND BEHIND THE
PASSAGE OF THE LINE OF STORMS. SO HAVE PUT IN VCSH 2 HOURS AHEAD
AND BEHIND THE PASSAGE OF THE LINE OF STORMS.
THE WINDS WILL BE SOUTHERLY AT 15 KNOTS WITH GUSTS UP TO 25 KNOTS
OVER THE TAF SITES THIS AFTERNOON AHEAD OF THE LINE OF STORMS.
THE WINDS WILL THEN SWING TO A MORE WESTERLY DIRECTION BEHIND THE
PASSAGE OF THE STORMS WITH SPEEDS DOWN TO AROUND 5 TO 10 KNOTS.
THE WINDS WILL THEN BECOME NORTHWEST AROUND 10 KNOTS ON SUNDAY
WITH THE PASSAGE OF THE COLD FRONT.
THE VIS WILL REMAIN IN THE VFR CONDITIONS OVER ALL OF THE TAF
SITES WITH CEILINGS IN THE MVFR TO VFR CONDITIONS. THE CEILING AND
VIS COULD FALL INTO THE IFR CONDITIONS WITH THE PASSAGE OF THE
LINE OF STORMS...BUT WILL MAKE ADMIN TO THE TAF SITES ONCE THE
LINE OF STORMS GET CLOSER TO THE TAF SITES.
&&
.AVIATION...54/BNB
.PREV DISCUSSION... /ISSUED 923 AM EDT SAT MAR 29 2014/
UPDATE...
MADE SOME MINOR ADJUSTMENTS TO THE FORECAST BASED ON CURRENT
TRENDS AND CURRENT OBSERVATIONS. HEAVY CLOUD FROM THUNDERSTORM
DEBRIS FIELD CURRENTLY COVERS MOST OF SOUTH FLORIDA THIS MORNING.
THE THUNDERSTORM COMPIEX IS LOCATED IN THE SOUTHEAST GULF OF
MEXICO ABOUT 150 MILES WEST OF NAPLES AND WAS MOVING VERY LITTLE.
THE MAIN TROUGH IS CURRENTLY DEEPENING OVER THE SOUTHERN GULF
STATES WHICH IS GENERATING A LINE OF THUNDERSTORMS OVER THE
NORTHEAST GULF OF MEXICO. MOST OF THIS ACTIVITY THROUGH THIS
AFTERNOON WILL BE AFFECTING CENTRAL FLORIDA. THE 12Z MFL SOUNDING
DOES SHOW SOME LOW LEVEL INSTABILITY BUT MID LEVEL LAPSE RATES
REMAIN WEAK. THE KEY ASPECT FOR SOUTH FLORIDA WEATHER THROUGH THE
REMAINDER OF THE DAY IS HOW MUCH CLEARING AND WARMING WILL TAKE
PLACE THIS AFTERNOON. THERE ARE NO SIGNS OF CLOUDS THINNING AT
THIS TIME AND THEREFORE LOWERED THE MAXIMUM TEMPERATURES ACROSS
THE INTERIOR. IT APPEARS AT THIS TIME THAT THE MAIN THREAT WILL BE
THIS EVENING AND OVERNIGHT AS THE MAIN BAND FROM THE NORTHEAST
GULF ARRIVES IN SOUTH FLORIDA AND THIS IS WHAT THE HRRR IS SHOWING
WITH NOT MUCH HAPPENING THROUGH AT LEAST 16Z AND SO FOLLOWED THIS
GUIDANCE.
&&
KOB
PREV DISCUSSION... /ISSUED 653 AM EDT SAT MAR 29 2014/
AVIATION...
A COLD FRONT OVER THE SOUTHEAST UNITED STATES WILL CONTINUE TO
MOVE SOUTH TOWARDS SOUTH FLORIDA TODAY. THIS WILL ALLOW FOR THE
WINDS OVER SOUTH FLORIDA TAF SITES TO SWING FROM A SOUTHEAST
DIRECTION THIS MORNING TO A SOUTHWEST DIRECTION BY LATE THIS
AFTERNOON INTO THIS EVENING. THE WIND SPEEDS WILL BE AROUND 10
KNOTS THIS MORNING INCREASING TO 10 TO 15 KNOTS BY THIS
AFTERNOON...BEFORE DECREASING AGAIN TO AROUND 10 KNOTS THIS
EVENING.
THERE WILL BE A THREAT OF SHOWERS THIS MORNING OVER THE TAF SITES
BEFORE A THUNDERSTORM THREAT THIS AFTERNOON MAINLY AFTER 18Z.
THE VIS AND CEILINGS OVER SOUTH FLORIDA TAF SITES WILL REMAIN IN
THE VFR CONDITIONS AT THIS TIME DUE TO THE UNKNOWN TIMING OF THE
SHOWERS AND THUNDERSTORMS. BUT WHEN THEY DO DEVELOP AND PUSH
THROUGH THE TAF SITES...THEY COULD FALL INTO THE IFR CONDITIONS.
&&
PREV DISCUSSION... /ISSUED 403 AM EDT SAT MAR 29 2014/
DISCUSSION...
MAIN FOCUS REMAINS OVER THE NEXT 24 TO 30 HOURS WITH SHOWER AND
THUNDERSTORM CHANCES ASSOCIATED WITH THE PASSAGE OF A COLD FRONT.
LATEST MICRON SATELLITE IMAGERY SHOWS A LINE OF THUNDERSTORMS ACROSS
THE NORTHERN GULF OF MEXICO AHEAD OF A COLD FRONT. THESE STORMS ARE
PUSHING TO THE EAST AND WILL AFFECT THE FLORIDA PANHANDLE THROUGH
THE MORNING. AN AREA OF LOW PRESSURE WILL DEEPEN AS IT SLIDES TO
THE NORTHEAST AND INTO THE APPALACHIANS. THIS WILL ALLOW THE COLD
FRONT TO PUSH FURTHER SOUTH AND THROUGH THE AREA BY LATE TONIGHT
AND INTO EARLY SUNDAY MORNING. SHOWERS AND THUNDERSTORMS WILL
BEGIN TO PUSH INTO SOUTH FLORIDA LATER TODAY AS THE FRONT
APPROACHES. BETTER DYNAMICS ARE STILL EXPECTED TO BE WELL NORTH OF
THE AREA AND THE BEST FORCING ALONG THE FRONT LOOKS TO ARRIVE WELL
AFTER DARK. HOWEVER...THE AIRMASS SHOULD STILL BE RATHER BUOYANT
WITH MODEL SOUNDINGS DEPICTING SBCAPE VALUES AROUND 2000 J/KG.
THEREFORE BELIEVE A FEW THUNDERSTORMS COULD PRODUCE GUSTY WINDS
AND BRIEF HEAVY DOWNPOURS WITH THE GREATEST COVERAGE OF SHOWERS
AND THUNDERSTORMS BEING OVERNIGHT.
THE FRONT SHOULD EXIT THE AREA COMPLETELY BY MIDDAY SUNDAY ALLOWING
A MUCH DRIER AIRMASS TO FILTER INTO THE AREA. STRONG PERSISTENT HIGH
PRESSURE WILL THEN DOMINATE THE WEATHER ACROSS THE FLORIDA PENINSULA
THROUGH VIRTUALLY ALL OF NEXT WEEK WITH NEAR NORMAL TEMPERATURES.
AVIATION...
A LOW PRESSURE SYSTEM OVER LOUISIANA WILL MOVE TO THE NORTHEAST
THROUGH THE TAF PERIOD. THIS WILL INITIALLY JUST KEEP WINDS OUT OF
THE SOUTHEAST WITH MID AND UPPER LEVEL CLOUDS. BY MID MORNING, CIGS
WILL LOWER, BUT SHOULD STILL BE GENERALLY MVFR, IF NOT VFR. THERE
WILL ALSO BE RAIN SHOWERS MOVING INTO SOUTH FLORIDA BY LATE MORNING.
IT IS ALSO POSSIBLE THAT A FEW THUNDERSTORMS WILL DEVELOP FROM MID
DAY ON, BUT THERE IS CURRENTLY TOO MUCH UNCERTAINTY TO PLACE THEM IN
THE TAFS AT THIS TIME. WINDS WILL PICKUP JUST AFTER SUNRISE, OUT OF
THE SOUTH-SOUTHEAST BETWEEN 10 AND 15 KTS. THEY WILL TURN MID DAY TO
THE SOUTHWEST AT AROUND 15 KTS. A COLD FRONT WILL THEN MOVE ACROSS
SOUTH FLORIDA SOMETIME IN THE OVERNIGHT HOURS. AHEAD OF THE FRONT,
IN THE EVENING HOURS, THE WINDS WILL BE MORE WEST SOUTHWEST AT 5 TO
10 KTS.
MARINE...
NORTHEASTERLY SWELL WILL CONTINUE TO DIMINISH THROUGH THE DAY AS
WINDS BECOME MORE SOUTHERLY. A COLD FRONT WILL CROSS THROUGH THE
AREA WATERS OVERNIGHT TONIGHT AND INTO SUNDAY MORNING TURNING
WINDS AROUND TO THE NORTH AND INCREASING TO AROUND 15 TO 20 MPH
WITH A BRIEF CORRESPONDING INCREASE IN SEAS ON SUNDAY BEFORE
DIMINISHING BY MONDAY AS WINDS DECREASE SLIGHTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 69 79 57 / 50 50 10 0
FORT LAUDERDALE 82 72 81 65 / 40 50 10 0
MIAMI 83 72 81 63 / 40 50 10 0
NAPLES 82 70 79 55 / 40 50 10 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...54/BNB
LONG TERM....30/KOB
AVIATION...54/BNB
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
646 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. DRY HIGH PRESSURE
WILL PREVAIL THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH NEXT
FRIDAY OR SATURDAY...FOLLOWED BY HIGH PRESSURE.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WELL PRONOUNCED PRE-FRONTAL TROUGH IS MOVING STEADILY EAST-
NORTHEAST THROUGH THE FORECAST AREA LATE THIS AFTERNOON AND WAS
ROUGHLY ALIGNED FROM KOGB-KNBC-FPGK1 AT 29/21Z. THE BEST CHANCES FOR
SHOWERS/TSTMS WILL BE FOUND AHEAD OF THIS FEATURE...BUT WITH RAP
SOUNDINGS SHOWING THE ATMOSPHERE BECOMING INCREASINGLY CAPPED AS
DRY SLOT ROTATES THROUGH AHEAD OF THE UPPER TROUGH...THE PROSPECTS
FOR DEEP/MOIST CONVECTION IS QUICKLY ENDING. HAVE UPDATED POPS TO
REDUCE THEM DOWN TO SLIGHT CHANCE ALONG AND AHEAD OF THE TROUGH
THROUGH SUNSET. SOME LIGHT SHOWER ACTIVITY MOVING THROUGH CENTRAL
GEORGIA ASSOCIATED WITH THE COLD FRONT ITSELF IS EXPECTED TO
DISSIPATE AS IT APPROACHES THE WESTERN PORTIONS OF THE FORECAST
AREA PER LATEST RUNS OF THE RAP AND H3R. ALTHOUGH A SPRINKLE OR
TWO COULD OCCUR...THE PROSPECTS FOR MEASURABLE PRECIPITATION THERE
HAS LIKELY ENDED. THE RISK FOR SEVERE TSTMS HAS ALSO ENDED AND THE
HAZARDOUS WEATHER OUTLOOK HAS BEEN UPDATED TO REFLECT THIS.
SEA FOG CONTINUES TO AFFECT THE SOUTH CAROLINA NEARSHORE WATERS
LATE THIS AFTERNOON. SOME OF THIS WILL IMPACT AREAS EAST OF
HIGHWAY 17 IN SOUTH CAROLINA FOR ANOTHER FEW HOURS BEFORE WINDS
VEER WESTERLY WITH THE PASSAGE OF THE PRE- FRONTAL TROUGH.
LAKE WINDS...WINDS WILL TURN MORE WESTERLY AND INCREASE SHARPLY OVER
LAKE MOULTRIE LATE TONIGHT. GUSTS TO 30 KT WILL BE POSSIBLE ALONG
AND IMMEDIATELY BEHIND THE FRONT AND WILL CONTINUE GUSTING INTO THE
25-30 KT RANGE THROUGH SUNRISE. A LAKE WIND ADVISORY IS IN PLACE AND
WILL BE MAINTAINED AS SUCH.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
DRY HIGH PRESSURE WILL SURGE INTO THE AREA SUNDAY AS THE UPPER LEVEL
RIDGE TAKES HOLD. 29/12Z GUIDANCE DEPICTS SOME WRAP-AROUND MOISTURE
IN THE 4-8 KFT AGL LAYER SWINGING THROUGH NORTHERN COUNTIES...
PERHAPS SUPPORTING SOME CLOUDS THERE. ELSEWHERE...FULL SUNSHINE
SHOULD PREVAIL. ALTHOUGH WEAK COLD ADVECTION IS FORECAST...STRONG
DOWNSLOPE FLOW AS STRONG AS 35-45 KT IN THE 925-850 MB LAYER WILL
PRODUCE CONSIDERABLE ADIABATIC HEATING. HIGH TEMPERATURES WILL CLIMB
INTO THE LOWER 70S IN SOUTHEAST GA WITH UPPER 60S ELSEWHERE. MODEL
SOUNDINGS INDICATE A 6-7 KFT MIXED LAYER DURING THE DAYTIME
HOURS...WHICH WILL SUPPORT SURFACE GUSTS 30-35 MPH. WINDS WILL
DIMINISH SUBSTANTIALLY AFTER SUNSET SUNDAY EVENING.
THE SURFACE HIGH WILL GRADUALLY BUILD EAST AND NW WINDS WILL
CONTINUE TO DIMINISH SUNDAY NIGHT...ALTHOUGH 29/12Z GUIDANCE
SUGGESTS THAT NW WINDS WILL PERSIST ESPECIALLY ACROSS SC COUNTIES
WELL INTO THE NIGHT. NEVERTHELESS...UNDER CLEAR SKIES TEMPERATURES
BY DAYBREAK MONDAY COULD DROP INTO THE UPPER 30S FAR INLAND WITH
LOWER TO MID 40S ELSEWHERE.
MONDAY THROUGH TUESDAY...A STRONG DEEP LAYERED RIDGE WILL BUILD OVER
THE SOUTHEAST UNITED STATES...PROVIDING INCREASING LOW-LEVEL
THICKNESSES AND AMPLE SUNSHINE. HIGH TEMPS WILL WARM INTO THE
MID/UPPER 70S MONDAY AND INTO THE LOWER 80S AT MANY LOCATIONS
TUESDAY. UNDER CLEAR SKIES/WITH LIGHT WINDS...RADIATIONAL COOLING
WILL SUPPORT LOWS IN THE MID TO UPPER 40S AT MOST LOCATIONS AWAY
FROM THE BEACHES. A FEW OF THE COOLER INLAND LOCATIONS COULD FALL TO
AROUND 40.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
DEEP LAYERED RIDGING WILL PERSIST TUESDAY NIGHT THROUGH THURSDAY
NIGHT WITH ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS. A
PROGRESSIVE UPPER LOW WILL MOVE THROUGH THE OHIO VALLEY LATE IN THE
WEEK...PUSHING A COLD FRONT THROUGH THE AREA FRIDAY OR FRIDAY NIGHT.
THIS MAY BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA BEFORE
DRY HIGH PRESSURE REBUILDS NEXT WEEKEND.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR. THE RISK FOR SHOWERS/TSTMS IMPACTING THE TERMINALS IS
DIMINISHING. WINDS WILL TURN MORE WESTERLY AND BECOME GUSTY AS
SKIES BEGIN TO CLEAR OUT WITH THE ARRIVAL OF DRIER AIR. LOW END
20-23 KT GUSTS WILL BE FREQUENT OVERNIGHT. THIS WILL INCREASE INTO
THE 27-30 KT RANGE FROM MID SUNDAY MORNING ONWARD AS WINDS BECOME
MORE NORTHWESTERLY.
EXTENDED AVIATION OUTLOOK...NORTHWEST WINDS WILL GUST 25-30 KNOTS
AT BOTH TERMINALS SUNDAY.
&&
.MARINE...
CANCELLED THE MARINE DENSE FOG ADVISORY FOR THE BEAUFORT COUNTY WATERS.
CONDITIONS HAVE IMPROVED THERE AS WINDS TURN SOUTHWEST AHEAD OF AN
APPROACHING COLD FRONT.
THIS AFTERNOON AND TONIGHT...THE BIGGEST IMMEDIATE CONCERN FOR THE
LOCAL WATERS IS THE ONGOING DENSE FOG EVENT ACROSS THE NEARSHORE
ZONES. COASTAL WEB CAMS SHOW THAT VISIBILITIES ARE STILL QUITE
POOR SO THE DENSE FOG ADVISORY CONTINUES INTO THE EVENING. THE FOG
WILL DISSIPATE ONCE WINDS BEGIN TO TURN MORE WESTERLY...WHICH WILL
CERTAINLY OCCUR WITH THE ARRIVAL OF THE COLD FRONT. THEN FOCUS
TURNS TO THE WESTERLY SURGE THAT WILL TAKE PLACE BEHIND THE STRONG
COLD FRONT. BASED ON INCOMING MODEL DATA...I HAVE OPTED TO
INCREASE EXPECTED WINDS TO BE 25-30 KT ACROSS THE NEARSHORE WATERS
LATE TONIGHT. FURTHERMORE...THE SMALL CRAFT ADVISORY HAS BEEN
UPGRADED TO A GALE WARNING FOR THE OUTER GEORGIA WATERS WITH
EXPECTED WINDS OF 30-35 KT. THE HARBOR WILL SEE SUSTAINED WINDS IN
THE 20-25 KT RANGE WITH GUSTS TO 30 KT AS WELL. WITH THE ARRIVAL
OF THE FRONT AND IMMEDIATELY BEHIND IT...THERE MAY BE AN ISOLATED
GUST TO GALE FORCE IN THE HARBOR AND THE NEARSHORE WATERS...BUT
THIS IS NOT EXPECTED TO BE FOR A DURATION LONG ENOUGH TO WARRANT A
GALE WARNING. SEAS WILL REMAIN ELEVATED THROUGH TONIGHT WITH THE
INCREASE IN LOW LEVEL FLOW...AND BECOME INCREASINGLY WIND DRIVEN
IN NATURE.
SUNDAY INTO SUNDAY NIGHT...ELEVATED WINDS/SEAS WILL PERSIST. GALE
FORCE GUSTS WILL CONTINUE ACROSS AMZ374...FOLLOWED BY SMALL CRAFT
ADVISORY WINDS/SEAS SUNDAY NIGHT...AND SMALL CRAFT ADVISORY
CONDITIONS WILL CONTINUE ELSEWHERE SUNDAY THROUGH SUNDAY EVENING...
AND ELEVATED WINDS/SEAS WILL PERSIST INTO EARLY MONDAY.
AS HIGH PRESSURE BUILDS OVER THE WATERS...A WEAKENING PRESSURE
PATTERN WILL TRANSLATE TO MUCH MORE TRANQUIL CONDITIONS MONDAY
AFTERNOON THROUGH MIDWEEK. A SEA BREEZE CIRCULATION WILL DEVELOP
EACH AFTERNOON.
AHEAD OF THE NEXT APPROACHING COLD FRONT...INCREASING SOUTHERLY
WINDS AND BUILDING SEAS ARE EXPECTED AND THE PROBABILITY FOR
MARINE FLAGS WILL INCREASE THURSDAY/FRIDAY.
&&
.FIRE WEATHER...
SUNDAY...NORTHWEST/DOWNSLOPE WINDS WILL GUST TO 30-35 MPH AS MINIMUM
RELATIVE HUMIDITY AVERAGES 20 TO 30 PERCENT. PER COLLABORATION WITH
FIRE WEATHER PARTNERS...NO FIRE WEATHER WATCHES/RED FLAG WARNINGS
ARE NEEDED DUE TO ELEVATED FUEL MOISTURE PRODUCED BY RECENT
RAINFALL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR AMZ352-354.
DENSE FOG ADVISORY UNTIL 10 PM EDT THIS EVENING FOR AMZ350.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR
AMZ330-350.
GALE WARNING UNTIL 6 PM EDT SUNDAY FOR AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
543 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE AREA TONIGHT. DRY HIGH PRESSURE
WILL PREVAIL THROUGH THURSDAY. A COLD FRONT WILL MOVE THROUGH NEXT
FRIDAY OR SATURDAY...FOLLOWED BY HIGH PRESSURE.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
A WELL PRONOUNCED PRE-FRONTAL TROUGH IS MOVING STEADILY EAST-
NORTHEAST THROUGH THE FORECAST AREA LATE THIS AFTERNOON AND WAS
ROUGHLY ALIGNED FROM KOGB-KNBC-FPGK1 AT 29/21Z. THE BEST CHANCES FOR
SHOWERS/TSTMS WILL BE FOUND AHEAD OF THIS FEATURE...BUT WITH RAP
SOUNDINGS SHOWING THE ATMOSPHERE BECOMING INCREASINGLY CAPPED AS
DRY SLOT ROTATES THROUGH AHEAD OF THE UPPER TROUGH...THE PROSPECTS
FOR DEEP/MOIST CONVECTION IS QUICKLY ENDING. HAVE UPDATED POPS TO
REDUCE THEM DOWN TO SLIGHT CHANCE ALONG AND AHEAD OF THE TROUGH
THROUGH SUNSET. SOME LIGHT SHOWER ACTIVITY MOVING THROUGH CENTRAL
GEORGIA ASSOCIATED WITH THE COLD FRONT ITSELF IS EXPECTED TO
DISSIPATE AS IT APPROACHES THE WESTERN PORTIONS OF THE FORECAST
AREA PER LATEST RUNS OF THE RAP AND H3R. ALTHOUGH A SPRINKLE OR
TWO COULD OCCUR...THE PROSPECTS FOR MEASURABLE PRECIPITATION THERE
HAS LIKELY ENDED. THE RISK FOR SEVERE TSTMS HAS ALSO ENDED AND THE
HAZARDOUS WEATHER OUTLOOK HAS BEEN UPDATED TO REFLECT THIS.
SEA FOG CONTINUES TO AFFECT THE SOUTH CAROLINA NEARSHORE WATERS
LATE THIS AFTERNOON. SOME OF THIS WILL IMPACT AREAS EAST OF
HIGHWAY 17 IN SOUTH CAROLINA FOR ANOTHER FEW HOURS BEFORE WINDS
VEER WESTERLY WITH THE PASSAGE OF THE PRE- FRONTAL TROUGH.
LAKE WINDS...WINDS WILL TURN MORE WESTERLY AND INCREASE SHARPLY OVER
LAKE MOULTRIE LATE TONIGHT. GUSTS TO 30 KT WILL BE POSSIBLE ALONG
AND IMMEDIATELY BEHIND THE FRONT AND WILL CONTINUE GUSTING INTO THE
25-30 KT RANGE THROUGH SUNRISE. A LAKE WIND ADVISORY IS IN PLACE AND
WILL BE MAINTAINED AS SUCH.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
DRY HIGH PRESSURE WILL SURGE INTO THE AREA SUNDAY AS THE UPPER LEVEL
RIDGE TAKES HOLD. 29/12Z GUIDANCE DEPICTS SOME WRAP-AROUND MOISTURE
IN THE 4-8 KFT AGL LAYER SWINGING THROUGH NORTHERN COUNTIES...
PERHAPS SUPPORTING SOME CLOUDS THERE. ELSEWHERE...FULL SUNSHINE
SHOULD PREVAIL. ALTHOUGH WEAK COLD ADVECTION IS FORECAST...STRONG
DOWNSLOPE FLOW AS STRONG AS 35-45 KT IN THE 925-850 MB LAYER WILL
PRODUCE CONSIDERABLE ADIABATIC HEATING. HIGH TEMPERATURES WILL CLIMB
INTO THE LOWER 70S IN SOUTHEAST GA WITH UPPER 60S ELSEWHERE. MODEL
SOUNDINGS INDICATE A 6-7 KFT MIXED LAYER DURING THE DAYTIME
HOURS...WHICH WILL SUPPORT SURFACE GUSTS 30-35 MPH. WINDS WILL
DIMINISH SUBSTANTIALLY AFTER SUNSET SUNDAY EVENING.
THE SURFACE HIGH WILL GRADUALLY BUILD EAST AND NW WINDS WILL
CONTINUE TO DIMINISH SUNDAY NIGHT...ALTHOUGH 29/12Z GUIDANCE
SUGGESTS THAT NW WINDS WILL PERSIST ESPECIALLY ACROSS SC COUNTIES
WELL INTO THE NIGHT. NEVERTHELESS...UNDER CLEAR SKIES TEMPERATURES
BY DAYBREAK MONDAY COULD DROP INTO THE UPPER 30S FAR INLAND WITH
LOWER TO MID 40S ELSEWHERE.
MONDAY THROUGH TUESDAY...A STRONG DEEP LAYERED RIDGE WILL BUILD OVER
THE SOUTHEAST UNITED STATES...PROVIDING INCREASING LOW-LEVEL
THICKNESSES AND AMPLE SUNSHINE. HIGH TEMPS WILL WARM INTO THE
MID/UPPER 70S MONDAY AND INTO THE LOWER 80S AT MANY LOCATIONS
TUESDAY. UNDER CLEAR SKIES/WITH LIGHT WINDS...RADIATIONAL COOLING
WILL SUPPORT LOWS IN THE MID TO UPPER 40S AT MOST LOCATIONS AWAY
FROM THE BEACHES. A FEW OF THE COOLER INLAND LOCATIONS COULD FALL TO
AROUND 40.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
DEEP LAYERED RIDGING WILL PERSIST TUESDAY NIGHT THROUGH THURSDAY
NIGHT WITH ABOVE NORMAL TEMPERATURES AND DRY CONDITIONS. A
PROGRESSIVE UPPER LOW WILL MOVE THROUGH THE OHIO VALLEY LATE IN THE
WEEK...PUSHING A COLD FRONT THROUGH THE AREA FRIDAY OR FRIDAY NIGHT.
THIS MAY BRING A FEW SHOWERS AND THUNDERSTORMS TO THE AREA BEFORE
DRY HIGH PRESSURE REBUILDS NEXT WEEKEND.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
VFR. THE RISK FOR SHOWERS/TSTMS IMPACTING THE TERMINALS IS
DIMINISHING. WINDS WILL TURN MORE WESTERLY AND BECOME GUSTY AS
SKIES BEGIN TO CLEAR OUT WITH THE ARRIVAL OF DRIER AIR. LOW END
20-23 KT GUSTS WILL BE FREQUENT OVERNIGHT. THIS WILL INCREASE INTO
THE 27-30 KT RANGE FROM MID SUNDAY MORNING ONWARD AS WINDS BECOME
MORE NORTHWESTERLY.
EXTENDED AVIATION OUTLOOK...NORTHWEST WINDS WILL GUST 25-30 KNOTS
AT BOTH TERMINALS SUNDAY.
&&
.MARINE...
CANCELLED THE MARINE DENSE FOG ADVISORY FOR THE GEORGIA NEARSHORE
WATERS. CONDITIONS HAVE IMPROVED THERE AS WINDS TURN SOUTHWEST
AHEAD OF AN APPROACHING COLD FRONT.
THIS AFTERNOON AND TONIGHT...THE BIGGEST IMMEDIATE CONCERN FOR THE
LOCAL WATERS IS THE ONGOING DENSE FOG EVENT ACROSS THE NEARSHORE
ZONES. COASTAL WEB CAMS SHOW THAT VISIBILITIES ARE STILL QUITE
POOR SO THE DENSE FOG ADVISORY CONTINUES INTO THE EVENING. THE FOG
WILL DISSIPATE ONCE WINDS BEGIN TO TURN MORE WESTERLY...WHICH WILL
CERTAINLY OCCUR WITH THE ARRIVAL OF THE COLD FRONT. THEN FOCUS
TURNS TO THE WESTERLY SURGE THAT WILL TAKE PLACE BEHIND THE STRONG
COLD FRONT. BASED ON INCOMING MODEL DATA...I HAVE OPTED TO
INCREASE EXPECTED WINDS TO BE 25-30 KT ACROSS THE NEARSHORE WATERS
LATE TONIGHT. FURTHERMORE...THE SMALL CRAFT ADVISORY HAS BEEN
UPGRADED TO A GALE WARNING FOR THE OUTER GEORGIA WATERS WITH
EXPECTED WINDS OF 30-35 KT. THE HARBOR WILL SEE SUSTAINED WINDS IN
THE 20-25 KT RANGE WITH GUSTS TO 30 KT AS WELL. WITH THE ARRIVAL
OF THE FRONT AND IMMEDIATELY BEHIND IT...THERE MAY BE AN ISOLATED
GUST TO GALE FORCE IN THE HARBOR AND THE NEARSHORE WATERS...BUT
THIS IS NOT EXPECTED TO BE FOR A DURATION LONG ENOUGH TO WARRANT A
GALE WARNING. SEAS WILL REMAIN ELEVATED THROUGH TONIGHT WITH THE
INCREASE IN LOW LEVEL FLOW...AND BECOME INCREASINGLY WIND DRIVEN
IN NATURE.
SUNDAY INTO SUNDAY NIGHT...ELEVATED WINDS/SEAS WILL PERSIST. GALE
FORCE GUSTS WILL CONTINUE ACROSS AMZ374...FOLLOWED BY SMALL CRAFT
ADVISORY WINDS/SEAS SUNDAY NIGHT...AND SMALL CRAFT ADVISORY
CONDITIONS WILL CONTINUE ELSEWHERE SUNDAY THROUGH SUNDAY EVENING...
AND ELEVATED WINDS/SEAS WILL PERSIST INTO EARLY MONDAY.
AS HIGH PRESSURE BUILDS OVER THE WATERS...A WEAKENING PRESSURE
PATTERN WILL TRANSLATE TO MUCH MORE TRANQUIL CONDITIONS MONDAY
AFTERNOON THROUGH MIDWEEK. A SEA BREEZE CIRCULATION WILL DEVELOP
EACH AFTERNOON.
AHEAD OF THE NEXT APPROACHING COLD FRONT...INCREASING SOUTHERLY
WINDS AND BUILDING SEAS ARE EXPECTED AND THE PROBABILITY FOR
MARINE FLAGS WILL INCREASE THURSDAY/FRIDAY.
&&
.FIRE WEATHER...
SUNDAY...NORTHWEST/DOWNSLOPE WINDS WILL GUST TO 30-35 MPH AS MINIMUM
RELATIVE HUMIDITY AVERAGES 20 TO 30 PERCENT. PER COLLABORATION WITH
FIRE WEATHER PARTNERS...NO FIRE WEATHER WATCHES/RED FLAG WARNINGS
ARE NEEDED DUE TO ELEVATED FUEL MOISTURE PRODUCED BY RECENT
RAINFALL.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR SCZ045.
MARINE...DENSE FOG ADVISORY UNTIL 10 PM EDT THIS EVENING FOR AMZ350-352.
SMALL CRAFT ADVISORY UNTIL 6 PM EDT SUNDAY FOR AMZ352-354.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EDT SUNDAY NIGHT FOR
AMZ330-350.
GALE WARNING UNTIL 6 PM EDT SUNDAY FOR AMZ374.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
252 PM CDT SAT MAR 29 2014
.DISCUSSION...
302 AM CDT
TODAY...
THIS MORNING...RIDGE OF HIGH PRESSURE EXTENDS FROM LAKE SUPERIOR
INTO THE MID MISSOURI VALLEY WHILE LOW PRESSURE LIES OVER
MISSISSIPPI/ALABAMA. THIS LOW WILL LIFT NORTH INTO THE UPPER OHIO
VALLEY TODAY RESULTING IN NORTHEASTERLY WINDS OFF OF LAKE MICHIGAN
THROUGH THE DAY. SOME PRECIP MAY BRUSH THE FAR SOUTHEASTERN COUNTIES
THIS MORNING...MAINLY IN THE FORM OF SNOW...THOUGH ANY ACCUMULATION
WILL LIKELY BE CONFINED TO GRASSY AREAS AND ONLY A DUSTING IS
EXPECTED. SPLIT CHANNEL IR IMAGERY SHOWS STRATUS STILL SPANS MUCH OF
THE UPPER MIDWEST...AS FAR WEST AS CENTRAL IOWA AND NORTHWEST INTO
CENTRAL WISCONSIN. EXPECT CLOUD COVER TO LINGER THROUGH AT LEAST
MIDDAY...THEN ANTICYCLONIC FLOW WITH THE RIDGE AXIS SHOULD START TO
BUILD IN FROM THE NORTHWEST THIS AFTERNOON AND EVENING WITH SKIES
CLEARING. TEMPERATURES TODAY ARE EXPECTED TO WARM INTO THE LOW TO
MID 40S...THOUGH WILL STAY IN THE 30S NEAR THE LAKE WITH THE
OFFSHORE FLOW THROUGH THE DAY.
SUNDAY AND MONDAY...
COMPACT UPPER WAVE WILL MOVE ONSHORE OVER SOCAL EARLY SUNDAY...THEN
TRANSLATE EAST ACROSS THE CENTRAL PLAINS BY MONDAY. SURFACE LOW WILL
DEEPEN IN RESPONSE OVER THE CENTRAL PLAINS THROUGH THE PERIOD WITH
STRONG WARM ADVECTION INTO THE REGION HELPING TO AMPLIFY THE
MID/UPPER LEVEL RIDGING. H85 TEMPS WILL WARM TO AROUND 10C BY SUNDAY
EVENING...AND 12C TO 13C BY MONDAY. CLIMO FROM NARR DATASET SHOWS
MEDIAN TEMPS IN THE LOW 70S WHEN H85 TEMPS EXCEED AROUND 9C FOR THE
LATTER HALF OF MARCH. WHILE THESE WARMER TEMPERATURES ALOFT WILL
ARRIVE LATER IN THE DAY SUNDAY...THEY SHOULD BE DIRECTLY OVERHEAD ON
MONDAY WHICH IS EXPECTED TO BE THE WARMEST DAY IN SOME TIME. BACKED
OFF SLIGHTLY ON TEMPS FOR SUNDAY...AND WHILE I THINK AREAS
ESPECIALLY IN THE WESTERN CWA STILL HAVE A GOOD CHANCE OF 60...IT
MAY STRUGGLE TO REACH 60 IN CHICAGO AND EASTERN PORTIONS OF THE CWA
DUE TO THE SLOWER ARRIVAL. THE MAIN CONCERNS FOR TEMPS MONDAY REVOLVE
AROUND CONVECTIVE CHANCES AND CLOUD COVER WHICH WILL INHIBIT HOW
WARM WE GET. H5 VORT TAKES ON A NEGATIVE TILT MONDAY AS IT LIFTS
ACROSS THE MID-MISSOURI VALLEY AND LEFT EXIT REGION OF UPPER JET
OVER THE AREA WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. LATEST
THINKING ON TIMING OF THE LOW STILL HAS THE BETTER FORCING WELL TO
THE WEST DURING PEAK HEATING WHEN SOME VERY MODEST SURFACE BASED
INSTABILITY EXISTS. WITH THUNDERSTORMS DEVELOPING TO THE
WEST...COULD SEE CIRRUS STREAMING OVERHEAD DURING THE DAY MONDAY
WHICH WILL IMPACT TEMPS. WITH A PRETTY DYNAMIC SYSTEM...MAY BE ABLE
TO OVERCOME THE LACK OF FAVORABLE THERMODYNAMICS FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP...PARTICULARLY IN THE LATER
AFTERNOON AND EVENING. REFINED POPS TO REFLECT THESE TIMING DETAILS
BUT MAINTAINED 20 TO 30 PERCENT DUE TO COVERAGE CONCERNS. AS FAR AS
TEMPS...REMAIN ON THE WARM SIDE OF THE SOLUTION ENVELOPE BUT WILL
HOLD OFF ON GOING ABOVE GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND
UNCERTAINTY IN PRECIP. WINDS WILL BECOME PROGRESSIVELY BREEZY
THROUGH THIS PERIOD...WITH GUSTS TO AROUND 20 MPH POSSIBLE ON SUNDAY
AND EVEN BREEZIER CONDITIONS ON MONDAY. 50KT WINDS ARE NOTED AROUND
900MB MONDAY...AND WITH DEEP MIXING POSSIBLE...THE AREA MAY SEE
30MPH+ GUSTS AT THE SURFACE DURING THE AFTERNOON.
TUESDAY THROUGH FRIDAY...
AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THE UPCOMING WORK WEEK AS A SERIES OF WAVES PROGRESS ACROSS THE
REGION. STILL CONSIDERABLE TIMING/TRACK DIFFERENCES THOUGH GUIDANCE
DOES SEEM TO BE FAVORING A MORE SOUTHERLY/COOLER PATTERN...
ESPECIALLY THE GFS WITH GOOD SUPPORT FROM THE GEFS. THE EMCWF
MAINTAINS A WARMER SOLUTION...WITH BAROCLINIC ZONE VERY NEAR
RESULTING IN A DECENT TEMPS SPREAD NORTH TO SOUTH ACROSS THE CWA.
CONTINUE TO RUN WITH A MODEL CONSENSUS BLEND FOR TEMPS NEXT WEEK
GIVEN THE HIGH DEGREE OF UNCERTAINTY...WHICH RESULTS IN WELL BELOW
NORMAL TEMPS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS SCATTERING/CLEARING TOWARD 21Z.
* NORTHEAST WINDS THROUGH THE EVENING.
MDB
//DISCUSSION...UPDATED 18Z...
MVFR STRATUS CONTINUES TO PUSH SOUTHWARD ACROSS THE CHICAGO AREA
TERMINALS WITH A CORRIDOR OF IFR CIGS AND MIST/DRIZZLE DOWN NEAR
GYY. THE IFR SHOULD IMPROVE AT GYY IN THE NEXT HOUR OR SO WHILE
ORD/MDW/DPA SEE STEADILY IMPROVING CLOUD BASES THEN SCATTERING OF
COVERAGE THROUGH EARLY AFTERNOON. OTHERWISE NORTHEASTERLY WINDS
WILL CONTINUE THROUGH THE EVENING WITH SPEEDS DIMINISHING INTO THE
OVERNIGHT HOURS. LIGHT AND VARIABLE WINDS FAVORING AN EAST THEN
SOUTHEAST DIRECTION ARE EXPECTED SUNDAY MORNING WITH STEADIER
SOUTH WINDS SPREADING IN FROM WEST TO EAST AS HIGH PRESSURE
CROSSES THE AREA. WITH THE HIGH OVERHEAD OVERNIGHT MAY SEE SOME
PATCHY FOG AT DPA...AND POSSIBLY RFD FOR A FEW HOURS THROUGH
DAYBREAK. WILL NOT INDICATE ANY RESTRICTIONS IN THESE TAFS FOR NOW
AS THE SETUP LOOKS A BIT MARGINAL.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN MVFR CIGS SCATTERING/CLEARING...MEDIUM
CONFIDENCE IN TIMING.
* HIGH CONFIDENCE IN WIND FORECAST.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF TSRA. GUSTY SOUTH WINDS.
TUESDAY...SLGT CHC OF RAIN DURING THE NIGHT.
WEDNESDAY...RAIN AND MVFR LIKELY.
THURSDAY AND FRIDAY...SLGT CHC OF RAIN AND SNOW.
LENNING
&&
.MARINE...
251 PM CDT
NORTH-NORTHEASTERLY ONSHORE FLOW ACROSS NORTHEASTERN ILLINOIS AND
NORTHWESTERN INDIANA CONTINUES UP AROUND 20S OUT AHEAD OF AN AREA OF
HIGH PRESSURE. THIS FLOW IS BIT STRONGER THAN PREVIOUSLY
THOUGH...AND AS A CONSEQUENCE OF THIS...I HAVE ISSUED A SMALL CRAFT
ADVISORY THROUGH THIS EVENING...MAINLY FOR THE EXPECTATION THAT
WAVES ARE AT OR JUST ABOVE THE 4 FOOT MARK. THESE WINDS WILL ABATE
THIS EVENING...THEN GRADUALLY BECOME EAST-SOUTHEASTERLY OVERNIGHT
TONIGHT AS THE SURFACE RIDGE SHIFTS OVER THE LAKE.
LOW PRESSURE WILL BE IN THE PROCESS OF DEVELOPING ACROSS THE CENTRAL
HIGH PLAINS ON SUNDAY...AND THIS WILL RESULT IN A CONTINUAL
SOUTH-SOUTHEASTERLY FLOW PATTERN ACROSS THE LAKE FOR THE NEXT COUPLE
OF DAYS. THE LOW IS EXPECTED TO TRACK EAST-NORTHEASTERLY TO THE
UPPER MISSISSIPPI VALLEY BY LATE MONDAY EVENING...THEN SHIFT ACROSS
THE UPPER GREAT LAKES BY TUESDAY EVENING. OVERALL...THIS WILL RESULT
IN INCREASING SOUTHERLY WINDS MONDAY AND INTO MONDAY
EVENING...LIKELY TO AROUND 30 KT. OVERALL...IT APPEARS THAT WARMER
AIR MOVING OVER THE LAKE WILL RESULT IN A STABLE MARINE
LAYER...WHICH WOULD RESULT IN LOWER CHANCES FOR GALES.
HOWEVER...SOME STRONGER WINDS NEARLY GALE FORCE ARE POSSIBLE WITH
THIS SYSTEM...ESPECIALLY MONDAY NIGHT AS THE LOW AND COLD FRONT
APPROACH THE LAKE. WESTERLY FLOW WILL SET UP TUESDAY IN THE WAKE OF
THIS SYSTEM.
ANOTHER STORM SYSTEM LOOKS TO TAKE AIM ON THE LOWER GREAT LAKES
LATER IN THE PERIOD...AROUND THURSDAY. THIS COULD RESULT IN A PERIOD
OF SOME ENHANCED NORTHEASTERLY WINDS INTO THE END OF THE UP COMING
WEEK.
KJB
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 10 PM SATURDAY.
&&
$$
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[top]
Area Forecast Discussion
National Weather Service Lincoln IL
228 PM CDT Sat Mar 29 2014
.DISCUSSION...
ISSUED 228 PM CDT Sat Mar 29 2014
The progressive weather pattern will provide active weather next
week as several storm systems affect Illinois. The latter half of
this weekend looks pleasant with plenty of sunshine pushing temps
above normal. However, by Monday afternoon the first system will
bring chances of rain, and the onset of a return to cooler
conditions. Heavier rains in the Wed to Thur time frame could
accumulate between 1-2" in some locations. Localized flooding may
develop.
SHORT TERM...Tonight through Sunday night.
Low clouds have been keeping high temps generally below forecast
highs this afternoon. A narrow break in the cloud cover allowed
Peoria to spike up about 10 degrees in a couple hours, and create
a large temperature gradient over short distances in our forecast
area. The RAP and HRRR layer RH indicate that some clearing should
continue west of I-57 between 23z and 03z. Lows tonight will be
dependent on cloud cover. Areas east of I-57 may remain cloudy
until just after midnight as NE surface winds continue to drag low-
level moisture from the Great Lakes into eastern IL. Even a few
hours of clearing later tonight should allow eastern areas to cool
off to near guidance lows, especially with surface dewpoints
dipping into the upper 20s in many locations.
Sunday will see mid level temps climb 5 to 7C during the day as an
upper level ridge axis advances into eastern IL by 00z/7pm Monday.
Near full sunshine should combine with increasing south winds to
push highs about 10 to 15 deg above normal (60s), which will be a
welcome taste of Spring. An tightening pressure gradient ahead of
the next system will keep south winds up in the 10 to 20 mph range
even Sunday night. So despite clear skies Sunday night, south
winds will keep a mixed boundary layer and allow lows to be in the
upper 40s west and around 40 east.
LONG TERM...Monday through Saturday.
Increasing clouds on Monday will not prohibit highs from climbing
well into the 60s for one more day, as south-southeast winds
increase into the 25 to 35 mph range. By Monday afternoon, a
parent low pressure system will advance from eastern Nebraska to
southeastern Minn, as a cold front reaches the western border of
IL by 00z/7pm Monday. Pre-frontal storms will have a high amount
of wind shear and storm relative helicity available, along with
steep lapse rates, but a limited amount of moisture. Forecast
soundings show the best instability may be at or above 750 mb, so
any thunderstorms will be elevated to begin. Due the strong jet
dynamics and wind shear with this system, some of the storms could
begin rotating and produce hail and strong winds Monday afternoon
and evening ahead of the cold front.
Showers and storms should end from west to east by midnight in the
post-frontal subsidence and dry air intrusion. Clouds will likely
clear out behind the line of precip, so lows in the NW could dip
below freezing, while southeast areas remain in the low 40s.
The brief pocket of cold air is forecast to brush across N IL late
Mon night and Tues morning, which will keep highs about 10-15 deg
colder than Monday. High temps will range from around 50 near
Galesburg to around 60 by Lawrenceville.
Return flow behind the cooler high pressure will bring increasing
moisture Tuesday night, with a few showers possible before sunrise
on Wednesday. Thunderstorm chances will increase along and south
of a warm front that is expected to develop directly across
central IL from west to east. Storm chances will be higher in the
warm sector roughly south of a line from Rushville to Champaign.
Instability may have a better chance of being based closer to the
surface as dewpoints climb into the 50s Wed night south of the
warm front, which will be close to overnight low temps.
Precipitable water values are expected to climb over an inch Wed
night through Thursday as low pressure tracks northeast along the
warm front. Locally heavy rain may occur in any thunderstorms,
with training of storms over the same area also boosting rainfall
amounts. Localized flooding could develop in low areas, as
rainfall amounts possibly reach between 1 and 2 inches by Thursday
afternoon.
A wide range of temps will occur across C IL from north to south
from Tues night through Thursday as the warm front lingers across
the middle of the area. The temp spreads could be 20 to 25 degrees
from north to south for highs and lows.
There is a spread of solutions for how the surface and upper level
systems progress from after Thursday. The GFS lingers the upper
trough farther west Thurs night, then brings a secondary surface
low and another round of rain showers across IL on Friday. The
ECMWF is more progressive and drys out the air column after the
low on Thursday. So low chance and slight chance PoPs were
included Thurs night and Friday to account for a slower
progression.
There is some agreement that another push of cold air will keep
temps below normal for Friday and Saturday, with Saturday looking
dry at this time.
Shimon
&&
.AVIATION...
ISSUED 1234 PM CDT Sat Mar 29 2014
MVFR stratus/SC will continue to affect terminals this afternoon.
A thin clear slot separates a lower MVFR cloud mass likely
augmented by Lake Michigan moisture, which has recently edged into
BMI/CMI. Brief reductions to IFR cigs/vsbys likely especially
towards CMI for the next few hours. Low level wind trajectories
favor this region to sink more south than southwest this afternoon,
staying east of PIA/SPI and possibly near DEC. Drier air
associated with a surface ridge over IA will help scour out the
cloud cover as it approaches the area late afternoon/early
evening. 10-15 kt north winds will subside this evening, then go
light/variable through sunrise as the ridge moves overhead. Return
flow brings southeast winds near/under 10 kts by late morning
along with scattered high clouds.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1256 PM CDT SAT MAR 29 2014
.DISCUSSION...
302 AM CDT
TODAY...
THIS MORNING...RIDGE OF HIGH PRESSURE EXTENDS FROM LAKE SUPERIOR
INTO THE MID MISSOURI VALLEY WHILE LOW PRESSURE LIES OVER
MISSISSIPPI/ALABAMA. THIS LOW WILL LIFT NORTH INTO THE UPPER OHIO
VALLEY TODAY RESULTING IN NORTHEASTERLY WINDS OFF OF LAKE MICHIGAN
THROUGH THE DAY. SOME PRECIP MAY BRUSH THE FAR SOUTHEASTERN COUNTIES
THIS MORNING...MAINLY IN THE FORM OF SNOW...THOUGH ANY ACCUMULATION
WILL LIKELY BE CONFINED TO GRASSY AREAS AND ONLY A DUSTING IS
EXPECTED. SPLIT CHANNEL IR IMAGERY SHOWS STRATUS STILL SPANS MUCH OF
THE UPPER MIDWEST...AS FAR WEST AS CENTRAL IOWA AND NORTHWEST INTO
CENTRAL WISCONSIN. EXPECT CLOUD COVER TO LINGER THROUGH AT LEAST
MIDDAY...THEN ANTICYCLONIC FLOW WITH THE RIDGE AXIS SHOULD START TO
BUILD IN FROM THE NORTHWEST THIS AFTERNOON AND EVENING WITH SKIES
CLEARING. TEMPERATURES TODAY ARE EXPECTED TO WARM INTO THE LOW TO
MID 40S...THOUGH WILL STAY IN THE 30S NEAR THE LAKE WITH THE
OFFSHORE FLOW THROUGH THE DAY.
SUNDAY AND MONDAY...
COMPACT UPPER WAVE WILL MOVE ONSHORE OVER SOCAL EARLY SUNDAY...THEN
TRANSLATE EAST ACROSS THE CENTRAL PLAINS BY MONDAY. SURFACE LOW WILL
DEEPEN IN RESPONSE OVER THE CENTRAL PLAINS THROUGH THE PERIOD WITH
STRONG WARM ADVECTION INTO THE REGION HELPING TO AMPLIFY THE
MID/UPPER LEVEL RIDGING. H85 TEMPS WILL WARM TO AROUND 10C BY SUNDAY
EVENING...AND 12C TO 13C BY MONDAY. CLIMO FROM NARR DATASET SHOWS
MEDIAN TEMPS IN THE LOW 70S WHEN H85 TEMPS EXCEED AROUND 9C FOR THE
LATTER HALF OF MARCH. WHILE THESE WARMER TEMPERATURES ALOFT WILL
ARRIVE LATER IN THE DAY SUNDAY...THEY SHOULD BE DIRECTLY OVERHEAD ON
MONDAY WHICH IS EXPECTED TO BE THE WARMEST DAY IN SOME TIME. BACKED
OFF SLIGHTLY ON TEMPS FOR SUNDAY...AND WHILE I THINK AREAS
ESPECIALLY IN THE WESTERN CWA STILL HAVE A GOOD CHANCE OF 60...IT
MAY STRUGGLE TO REACH 60 IN CHICAGO AND EASTERN PORTIONS OF THE CWA
DUE TO THE SLOWER ARRIVAL. THE MAIN CONCERNS FOR TEMPS MONDAY REVOLVE
AROUND CONVECTIVE CHANCES AND CLOUD COVER WHICH WILL INHIBIT HOW
WARM WE GET. H5 VORT TAKES ON A NEGATIVE TILT MONDAY AS IT LIFTS
ACROSS THE MID-MISSOURI VALLEY AND LEFT EXIT REGION OF UPPER JET
OVER THE AREA WILL PROVIDE ADDITIONAL BROAD SCALE ASCENT. LATEST
THINKING ON TIMING OF THE LOW STILL HAS THE BETTER FORCING WELL TO
THE WEST DURING PEAK HEATING WHEN SOME VERY MODEST SURFACE BASED
INSTABILITY EXISTS. WITH THUNDERSTORMS DEVELOPING TO THE
WEST...COULD SEE CIRRUS STREAMING OVERHEAD DURING THE DAY MONDAY
WHICH WILL IMPACT TEMPS. WITH A PRETTY DYNAMIC SYSTEM...MAY BE ABLE
TO OVERCOME THE LACK OF FAVORABLE THERMODYNAMICS FOR SOME SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP...PARTICULARLY IN THE LATER
AFTERNOON AND EVENING. REFINED POPS TO REFLECT THESE TIMING DETAILS
BUT MAINTAINED 20 TO 30 PERCENT DUE TO COVERAGE CONCERNS. AS FAR AS
TEMPS...REMAIN ON THE WARM SIDE OF THE SOLUTION ENVELOPE BUT WILL
HOLD OFF ON GOING ABOVE GUIDANCE GIVEN THE EXPECTED CLOUD COVER AND
UNCERTAINTY IN PRECIP. WINDS WILL BECOME PROGRESSIVELY BREEZY
THROUGH THIS PERIOD...WITH GUSTS TO AROUND 20 MPH POSSIBLE ON SUNDAY
AND EVEN BREEZIER CONDITIONS ON MONDAY. 50KT WINDS ARE NOTED AROUND
900MB MONDAY...AND WITH DEEP MIXING POSSIBLE...THE AREA MAY SEE
30MPH+ GUSTS AT THE SURFACE DURING THE AFTERNOON.
TUESDAY THROUGH FRIDAY...
AN ACTIVE PATTERN IS EXPECTED TO CONTINUE THROUGH THE REMAINDER OF
THE UPCOMING WORK WEEK AS A SERIES OF WAVES PROGRESS ACROSS THE
REGION. STILL CONSIDERABLE TIMING/TRACK DIFFERENCES THOUGH GUIDANCE
DOES SEEM TO BE FAVORING A MORE SOUTHERLY/COOLER PATTERN...
ESPECIALLY THE GFS WITH GOOD SUPPORT FROM THE GEFS. THE EMCWF
MAINTAINS A WARMER SOLUTION...WITH BAROCLINIC ZONE VERY NEAR
RESULTING IN A DECENT TEMPS SPREAD NORTH TO SOUTH ACROSS THE CWA.
CONTINUE TO RUN WITH A MODEL CONSENSUS BLEND FOR TEMPS NEXT WEEK
GIVEN THE HIGH DEGREE OF UNCERTAINTY...WHICH RESULTS IN WELL BELOW
NORMAL TEMPS.
DEUBELBEISS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* MVFR CIGS SCATTERING/CLEARING TOWARD 21Z.
* NORTHEAST WINDS THROUGH THE EVENING.
MDB
//DISCUSSION...UPDATED 18Z...
MVFR STRATUS CONTINUES TO PUSH SOUTHWARD ACROSS THE CHICAGO AREA
TERMINALS WITH A CORRIDOR OF IFR CIGS AND MIST/DRIZZLE DOWN NEAR
GYY. THE IFR SHOULD IMPROVE AT GYY IN THE NEXT HOUR OR SO WHILE
ORD/MDW/DPA SEE STEADILY IMPROVING CLOUD BASES THEN SCATTERING OF
COVERAGE THROUGH EARLY AFTERNOON. OTHERWISE NORTHEASTERLY WINDS
WILL CONTINUE THROUGH THE EVENING WITH SPEEDS DIMINISHING INTO THE
OVERNIGHT HOURS. LIGHT AND VARIABLE WINDS FAVORING AN EAST THEN
SOUTHEAST DIRECTION ARE EXPECTED SUNDAY MORNING WITH STEADIER
SOUTH WINDS SPREADING IN FROM WEST TO EAST AS HIGH PRESSURE
CROSSES THE AREA. WITH THE HIGH OVERHEAD OVERNIGHT MAY SEE SOME
PATCHY FOG AT DPA...AND POSSIBLY RFD FOR A FEW HOURS THROUGH
DAYBREAK. WILL NOT INDICATE ANY RESTRICTIONS IN THESE TAFS FOR NOW
AS THE SETUP LOOKS A BIT MARGINAL.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN MVFR CIGS SCATTERING/CLEARING...MEDIUM
CONFIDENCE IN TIMING.
* HIGH CONFIDENCE IN WIND FORECAST.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...VFR.
MONDAY...CHANCE OF TSRA. GUSTY SOUTH WINDS.
TUESDAY...SLGT CHC OF RAIN DURING THE NIGHT.
WEDNESDAY...RAIN AND MVFR LIKELY.
THURSDAY AND FRIDAY...SLGT CHC OF RAIN AND SNOW.
LENNING
&&
.MARINE...
310 AM CDT
WINDS GENERALLY WILL REMAIN NORTHERLY OR NORTHEASTERLY TODAY AHEAD
OF AN APPROACHING HIGH PRESSURE RIDGE...THEN WILL VEER EAST AFTER
THE RIDGE PASSES EARLY SUNDAY. THE EAST OR SOUTHEAST FLOW THEN
PERSISTS THROUGH THE WEEKEND INTO EARLY NEXT WEEK. STRONG LOW
PRESSURE MOVES THROUGH THE NORTHERN PART OF THE LAKE MONDAY
NIGHT...LIKELY SUPPORTING A PERIOD OF GALES ON THE SOUTHERN HALF.
THE WARM SOUTHERLY FLOW AHEAD OF THE LOW MONDAY AFTERNOON WILL BE
VERY STRONG BUT MAY BE LESS EFFECTIVE AT CREATING GALES THAN THE
WEAKER BUT COLDER WINDS BEHIND THE LOW ON MONDAY NIGHT AND
TUESDAY.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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Area Forecast Discussion
National Weather Service Lincoln IL
1234 PM CDT Sat Mar 29 2014
.DISCUSSION...
ISSUED 1024 AM CDT Sat Mar 29 2014
Showers associated with low pressure in the eastern Tennessee
Valley has now shifted east into Indiana and have updated forecast
to reflect dry conditions across the entire CWA for the remainder
of the day. Plenty of stratus continues to plague the region again
today and main forecast issue is the potential for afternoon
clearing and associated affect on high temps. A sliver of clearing
is approaching the northern CWA but already starting to fill in
with SC and a larger batch of stratus over NE IL is quickly
advecting in behind this on NNE low level flow. Think clouds will
hang tough as long as low level flow remains out of N/NNE which
should last well into afternoon. As the low pulls further east
winds will eventually come around to N/NNW advecting in drier air
from NW IL and eastern IA, and subsidence off surface ridge to our
west should help break up cloud deck. With this in mind have
increased cloud cover through mid afternoon, lowered highs a
degree or two, and slowed diurnal temp rise.
&&
.AVIATION...
ISSUED 1234 PM CDT Sat Mar 29 2014
MVFR stratus/SC will continue to affect terminals this afternoon.
A thin clear slot separates a lower MVFR cloud mass likely
augmented by Lake Michigan moisture, which has recently edged into
BMI/CMI. Brief reductions to IFR cigs/vsbys likely especially
towards CMI for the next few hours. Low level wind trajectories
favor this region to sink more south than southwest this afternoon,
staying east of PIA/SPI and possibly near DEC. Drier air
associated with a surface ridge over IA will help scour out the
cloud cover as it approaches the area late afternoon/early
evening. 10-15 kt north winds will subside this evening, then go
light/variable through sunrise as the ridge moves overhead. Return
flow brings southeast winds near/under 10 kts by late morning
along with scattered high clouds.
25
&&
.PREV DISCUSSION...
ISSUED 227 AM CDT Sat Mar 29 2014
Surface low tracking across northern Mississippi early this
morning, while an upper trough moves through Iowa and western
Missouri. Area of showers streaming northward ahead of the upper
trough has made it up to around Taylorville and Sullivan as of 2
am, although the leading edge has had to fight some dry air to
make it that far.
A rather active weather pattern is on tap for next week, with
precipitation timing the primary forecast concern.
SHORT TERM...Today through Monday:
Will maintain some precipitation chances across the far eastern
CWA for the first few hours after sunrise, until the trough moves
into Illinois. Forecast soundings off the RAP model suggest some
rain/snow mix north of I-70 until the ice crystals are lost by mid
morning, with rain to the south. Otherwise, will see a decrease in
clouds from west to east this afternoon, as ridge axis moves
southeast out of the northern Plains.
Decent warm air advection sets up early Sunday as the high drifts
east of the state. With abundant sunshine, have sided more toward
the MAV MOS highs in the lower to mid 60s, with temperatures in
the mid to upper 60s on Monday. Monday looks to be fairly windy
ahead of the next storm system, with Bufkit data suggesting wind
gusts of 30-40 mph. Main surface low expected to track northeast
into southern Minnesota by late afternoon, with the trailing cold
front sweeping through the forecast area during the evening. Lower
levels of the forecast soundings are rather dry though except for
a brief window late afternoon and early evening, so will maintain
PoP`s only in the 30 percent range.
LONG TERM...Tuesday through Friday:
Upper troughing begins to dig across California Tuesday night as a
closed low moves southeast toward Los Angeles. As the week
progresses, the question becomes how deep this remains and how
fast the remaining closed low is ejected northeast. GFS and ECMWF
maintain a rather wide range as a storm system develops over the
Plains. The GFS remains much further south, with more of an
inverted trough extending over southeast Illinois by Thursday
morning. The ECMWF loiters a warm front just north of I-72 most of
Wednesday and Thursday, before the parent low arrives Thursday
evening. Both solutions would favor widespread showers, although
the warmer ECMWF would suggest thunder being more widespread. Have
not changed too much from the previous forecast, which favored the
ECMWF and warmer temperatures.
Geelhart
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
404 PM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 0404 PM EDT SAT MAR 29 2014
PRECIPITATION HAS NOW EXITED THE FORECAST AREA WITH CLOUDY AND COOL
CONDITIONS REMAINING THROUGH THE AFTERNOON. OVERNIGHT LOWS WILL BE
COLD IN THE LOW TO MID 20S BEFORE TEMPERATURES WARM UP NICELY ON
SUNDAY INTO THE LOW TO MID 50S. EVEN WARMER CONDITIONS ARE
ANTICIPATED ON MONDAY AS HIGH TEMPEARTURES RISE INTO THE MID 60S
UNDER PARTLY CLOUDY SKIES.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 328 PM EDT SAT MAR 29 2014
NO SIG ISSUES TO WORRY ABOUT FOR THE SHORT TERM AS RAIN/SNOW THAT
HAS FELL ACROSS MUCH OF THE SOUTHERN GREAT LAKES TODAY WAS NEARLY
OUT OF THE FORECAST AREA. FOCUS WILL SHIFT TO CLEARING TONIGHT AND
HOW WARM WE GET ON SUNDAY.
BY IN LARGE THE HEAVIER SNOWBANDS HAVE DIMINISHED WITH REMAINING
RAIN/SNOW ACROSS PORTIONS OF HENRY/PUTNAM AND ALLEN COUNTIES IN
OHIO. SFC LOW WAS OVER NE TENNESSEE AT 18Z AND SLOWLY DEEPENING
WITH AN INCREASING PRESSURE GRADIENT AROUND IT. THIS WILL KEEP
SOMEWHAT BREEZY CONDITIONS MAINLY EAST INTO THIS EVENING BEFORE THE
LOW SHIFTS EAST. LOW CLOUDS HAVE BEEN SLOW TO ERODE IN THE WEST AND
NORTH WITH NAM AND RUC VARYING ON HANDLING OF CLEARING. RUC 925/850
MB RH PLOT HAVE HANDLED THINGS WELL AND LINGER LOW CLOUDS INTO LATE
EVENING WITH NAM MUCH QUICKER ERODING MSTR. WITH VIS SAT SHOWING
HINTS AT SOME THIN SPOTS STARTING TO APPEAR SO HAVE TRIED TO BLEND
THE 2 MODELS WHICH STILL BRINGS GENERALLY CLEAR SKIES BY LATE
EVENING. LOWS WILL DROP INTO THE 20S DESPITE COLDEST AIR WITH THE
SYSTEM ALREADY EAST OF THE REGION AND WAA UNDERWAY LATER TONIGHT.
SOME OF THIS WAA WILL BE REALIZED ON SUNDAY AS LOTS OF SUNSHINE
ALLOWS FOR MIXING THROUGH AT LEAST 900 MB AND MAYBE A BIT HIGHER
YIELDS HIGHS IN THE 50S. WOULDN`T BE ENTIRELY SURPRISED TO SEE SOME
UPR 50S TO NEAR 60 IN FAR W/SW AREAS.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 PM EDT SAT MAR 29 2014
VERY FEW CHANGES TO OVERALL IDEA IN LONG TERM PERIOD. AN ACTIVE
PATTERN WILL CONTINUE THROUGH THE PERIOD WITH NUMEROUS SHORT WAVES
AND A QUASI STATIONARY BOUNDARY IN THE REGION. THIS SHOULD LEAD TO
RATHER WET PERIOD WITH TEMPERATURES A LITTLE CLOSER TO NORMAL FOR
EARLY APRIL.
RIDGE WILL BE OVER THE AREA SUNDAY NIGHT PROVIDING CLEAR SKIES AND
LIGHT WINDS. LOWS EXPECTED IN THE LOWER 30S EAST UNDER RIDGE AXIS TO
UPPER 30S WEST WHERE WARM AIR ADVECTION ON BACK SIDE OF RIDGE WILL
BE INCREASING. THIS WARMING SHOULD TRANSLATE TO A LARGE DIURNAL
SWING ON MONDAY AS STRONG MIXING DEVELOPS AND WARM AIR ALOFT IS
ALLOWED TO MIX TO SURFACE. SHOULD BECOME BREEZY AS WELL TO HELP
BOOST TEMPERATURES. INCREASING HIGH CLOUDS IN AFTERNOON MAY TEMPER
WARM UP BY A FEW DEGREES DEPENDING ON HOW THICK CLOUD CANOPY IS AND
TIMING OF IT. STILL EXPECT 60S ALL AREAS WITH RUN AT MID TO UPPER
60S ACROSS THE AREA IF SKIES REMAIN MOSTLY SUNNY THROUGH AFTERNOON
PEAK HEATING.
NEXT OF MANY SHORT WAVES MOVES THROUGH THE LAKES REGION MONDAY NIGHT
WITH A TRAILING COLD FRONT THROUGH THE CWA EARLY TUESDAY MORNING.
ENOUGH MOISTURE AND WEAK LIFT TO WARRANT LOW CHANCE POPS BUT
STRONGEST FORCING TO THE NORTH CLOSER TO MAIN LOW. WARMEST TEMPS OF
THE DAY LIKELY IN MORNING BEFORE FROPA BUT DRYING PROFILES TUE
AFTERNOON SUGGEST SUN COULD ALLOW FOR SOME REBOUND SIMILAR TO WHAT
SOME LOCATIONS EXPERIENCED FRIDAY.
DETAILS REMAIN UNCERTAIN FOR REMAINDER OF LONG TERM WITH
AFOREMENTIONED COLD FRONT BECOMING STATIONARY NEAR OR JUST SOUTH OF
CWA. SEVERAL SHORT WAVES ARE EXPECTED WEDNESDAY INTO FRIDAY WITH
ASSOCIATED SURFACE WAVES RIPPLING ALONG FRONTAL BOUNDARY. SEVERAL
CHANCES FOR RAINFALL DURING THE PERIOD WITH UNCERTAINTY IN TIMING.
THUS A CONTINUATION OF BROAD HIGH CHANCE POP CONTINUES WITH FURTHER
INCREASE LIKELY AS TIME NEARS. WITH INCREASING PWATS AND THETA E
AIR...MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS STILL PLAUSIBLE.
TEMPS DURING THIS PERIOD LIKELY NEAR NORMAL SOUTH AND SLIGHTLY BELOW
NORMAL NORTH BUT IF FRONT WAVERS NORTH OR SOUTH...SIGNIFICANT
CHANGES IN TEMPERATURE FORECASTS WOULD BE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 138 PM EDT SAT MAR 29 2014
WITH PRECIP ISSUES NOW OUT OF THE WAY AT BOTH SITES FOCUS WILL BE
ON TIMING OF DEPARTURE OF LOW CLOUDS AND RETURN OF VFR CONDITIONS.
WESTERN EDGE OF THE RAIN/SNOW SHIELD CLEARED KFWA OVER THE PAST 20
MINUTES WITH LITTLE MORE THAN SOME DRIZZLE/VRY LGT RAIN LEFT IN
ITS WAKE. VSBYS WILL REMAIN MVFR DUE TO FOG...BUT CIGS WILL REMAIN
THE BIGGER ISSUE SITTING AROUND 1000 TO 1500 FT. A LOW RISE IN
CIGS IS EXPECTED...FIRST AT KSBN WHERE CIGS WILL COME UP TO 2500
TO 3000 FT LATER THIS AFTERNOON. SLOWER PROGRESS OF LOW CLOUDS
EXPECTED AT KFWA GIVEN PROXIMITY OF SFC LOW TO THE SE. HOWEVER
THEY WILL CATCH UP WITH TIME. RECENT RUC DATA HAD A GOOD HANDLE ON
CLOUD COVER AND FOLLOWED CLOSELY THROUGH TONIGHT. ONCE THE CLOUDS
DEPART VFR CONDITIONS WILL PREVAIL INTO TOMORROW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
331 PM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 1022 AM EDT SAT MAR 29 2014
A LOW PRESSURE SYSTEM WILL BE PASSING THROUGH THE SOUTHEASTERN
UNITED STATES TODAY AND THE CENTER WILL MOVE TO THE WASHINGTON
D.C. AREA BY TOMORROW MORNING. THIS SYSTEM WILL PASS SOME
PRECIPITATION THROUGH THE REGION TODAY IN THE FORM OF RAIN IN THE
FAR SOUTH...MIX OF RAIN AND SNOW IN THE CENTRAL AREAS...AND MAINLY
SNOW IN THE NORTH. AREAS IN THE CENTRAL TO NORTHERN PART OF THE
REGION COULD SEE THE PRECIPITATION START OUT AS RAIN THEN SWITCH
TO A MIX BEFORE FINALLY ALL SNOW. SNOWFALL AMOUNTS ARE EXPECTED TO
BE SMALL. HIGH TEMPERATURES TODAY WILL RANGE FROM THE UPPER 30S IN
THE SOUTHEASTERN HALF OF THE REGION TO THE LOWER 40S IN THE
NORTHWESTERN HALF. TONIGHT WILL BE DRY ACROSS THE REGION WITH
CLEARING SKIES AND TEMPERATURES DROPPING IN TO THE 20S.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 328 PM EDT SAT MAR 29 2014
NO SIG ISSUES TO WORRY ABOUT FOR THE SHORT TERM AS RAIN/SNOW THAT
HAS FELL ACROSS MUCH OF THE SOUTHERN GREAT LAKES TODAY WAS NEARLY
OUT OF THE FORECAST AREA. FOCUS WILL SHIFT TO CLEARING TONIGHT AND
HOW WARM WE GET ON SUNDAY.
BY IN LARGE THE HEAVIER SNOWBANDS HAVE DIMINISHED WITH REMAINING
RAIN/SNOW ACROSS PORTIONS OF HENRY/PUTNAM AND ALLEN COUNTIES IN
OHIO. SFC LOW WAS OVER NE TENNESSEE AT 18Z AND SLOWLY DEEPENING
WITH AN INCREASING PRESSURE GRADIENT AROUND IT. THIS WILL KEEP
SOMEWHAT BREEZY CONDITIONS MAINLY EAST INTO THIS EVENING BEFORE THE
LOW SHIFTS EAST. LOW CLOUDS HAVE BEEN SLOW TO ERODE IN THE WEST AND
NORTH WITH NAM AND RUC VARYING ON HANDLING OF CLEARING. RUC 925/850
MB RH PLOT HAVE HANDLED THINGS WELL AND LINGER LOW CLOUDS INTO LATE
EVENING WITH NAM MUCH QUICKER ERODING MSTR. WITH VIS SAT SHOWING
HINTS AT SOME THIN SPOTS STARTING TO APPEAR SO HAVE TRIED TO BLEND
THE 2 MODELS WHICH STILL BRINGS GENERALLY CLEAR SKIES BY LATE
EVENING. LOWS WILL DROP INTO THE 20S DESPITE COLDEST AIR WITH THE
SYSTEM ALREADY EAST OF THE REGION AND WAA UNDERWAY LATER TONIGHT.
SOME OF THIS WAA WILL BE REALIZED ON SUNDAY AS LOTS OF SUNSHINE
ALLOWS FOR MIXING THROUGH AT LEAST 900 MB AND MAYBE A BIT HIGHER
YIELDS HIGHS IN THE 50S. WOULDN`T BE ENTIRELY SURPRISED TO SEE SOME
UPR 50S TO NEAR 60 IN FAR W/SW AREAS.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 328 PM EDT SAT MAR 29 2014
VERY FEW CHANGES TO OVERALL IDEA IN LONG TERM PERIOD. AN ACTIVE
PATTERN WILL CONTINUE THROUGH THE PERIOD WITH NUMEROUS SHORT WAVES
AND A QUASI STATIONARY BOUNDARY IN THE REGION. THIS SHOULD LEAD TO
RATHER WET PERIOD WITH TEMPERATURES A LITTLE CLOSER TO NORMAL FOR
EARLY APRIL.
RIDGE WILL BE OVER THE AREA SUNDAY NIGHT PROVIDING CLEAR SKIES AND
LIGHT WINDS. LOWS EXPECTED IN THE LOWER 30S EAST UNDER RIDGE AXIS TO
UPPER 30S WEST WHERE WARM AIR ADVECTION ON BACK SIDE OF RIDGE WILL
BE INCREASING. THIS WARMING SHOULD TRANSLATE TO A LARGE DIURNAL
SWING ON MONDAY AS STRONG MIXING DEVELOPS AND WARM AIR ALOFT IS
ALLOWED TO MIX TO SURFACE. SHOULD BECOME BREEZY AS WELL TO HELP
BOOST TEMPERATURES. INCREASING HIGH CLOUDS IN AFTERNOON MAY TEMPER
WARM UP BY A FEW DEGREES DEPENDING ON HOW THICK CLOUD CANOPY IS AND
TIMING OF IT. STILL EXPECT 60S ALL AREAS WITH RUN AT MID TO UPPER
60S ACROSS THE AREA IF SKIES REMAIN MOSTLY SUNNY THROUGH AFTERNOON
PEAK HEATING.
NEXT OF MANY SHORT WAVES MOVES THROUGH THE LAKES REGION MONDAY NIGHT
WITH A TRAILING COLD FRONT THROUGH THE CWA EARLY TUESDAY MORNING.
ENOUGH MOISTURE AND WEAK LIFT TO WARRANT LOW CHANCE POPS BUT
STRONGEST FORCING TO THE NORTH CLOSER TO MAIN LOW. WARMEST TEMPS OF
THE DAY LIKELY IN MORNING BEFORE FROPA BUT DRYING PROFILES TUE
AFTERNOON SUGGEST SUN COULD ALLOW FOR SOME REBOUND SIMILAR TO WHAT
SOME LOCATIONS EXPERIENCED FRIDAY.
DETAILS REMAIN UNCERTAIN FOR REMAINDER OF LONG TERM WITH
AFOREMENTIONED COLD FRONT BECOMING STATIONARY NEAR OR JUST SOUTH OF
CWA. SEVERAL SHORT WAVES ARE EXPECTED WEDNESDAY INTO FRIDAY WITH
ASSOCIATED SURFACE WAVES RIPPLING ALONG FRONTAL BOUNDARY. SEVERAL
CHANCES FOR RAINFALL DURING THE PERIOD WITH UNCERTAINTY IN TIMING.
THUS A CONTINUATION OF BROAD HIGH CHANCE POP CONTINUES WITH FURTHER
INCREASE LIKELY AS TIME NEARS. WITH INCREASING PWATS AND THETA E
AIR...MODERATE TO LOCALLY HEAVY RAINFALL AMOUNTS STILL PLAUSIBLE.
TEMPS DURING THIS PERIOD LIKELY NEAR NORMAL SOUTH AND SLIGHTLY BELOW
NORMAL NORTH BUT IF FRONT WAVERS NORTH OR SOUTH...SIGNIFICANT
CHANGES IN TEMPERATURE FORECASTS WOULD BE EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 138 PM EDT SAT MAR 29 2014
WITH PRECIP ISSUES NOW OUT OF THE WAY AT BOTH SITES FOCUS WILL BE
ON TIMING OF DEPARTURE OF LOW CLOUDS AND RETURN OF VFR CONDITIONS.
WESTERN EDGE OF THE RAIN/SNOW SHIELD CLEARED KFWA OVER THE PAST 20
MINUTES WITH LITTLE MORE THAN SOME DRIZZLE/VRY LGT RAIN LEFT IN
ITS WAKE. VSBYS WILL REMAIN MVFR DUE TO FOG...BUT CIGS WILL REMAIN
THE BIGGER ISSUE SITTING AROUND 1000 TO 1500 FT. A LOW RISE IN
CIGS IS EXPECTED...FIRST AT KSBN WHERE CIGS WILL COME UP TO 2500
TO 3000 FT LATER THIS AFTERNOON. SLOWER PROGRESS OF LOW CLOUDS
EXPECTED AT KFWA GIVEN PROXIMITY OF SFC LOW TO THE SE. HOWEVER
THEY WILL CATCH UP WITH TIME. RECENT RUC DATA HAD A GOOD HANDLE ON
CLOUD COVER AND FOLLOWED CLOSELY THROUGH TONIGHT. ONCE THE CLOUDS
DEPART VFR CONDITIONS WILL PREVAIL INTO TOMORROW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
SYNOPSIS...LOTHAMER
SHORT TERM...FISHER
LONG TERM...LASHLEY
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
147 PM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 1022 AM EDT SAT MAR 29 2014
A LOW PRESSURE SYSTEM WILL BE PASSING THROUGH THE SOUTHEASTERN
UNITED STATES TODAY AND THE CENTER WILL MOVE TO THE WASHINGTON
D.C. AREA BY TOMORROW MORNING. THIS SYSTEM WILL PASS SOME
PRECIPITATION THROUGH THE REGION TODAY IN THE FORM OF RAIN IN THE
FAR SOUTH...MIX OF RAIN AND SNOW IN THE CENTRAL AREAS...AND MAINLY
SNOW IN THE NORTH. AREAS IN THE CENTRAL TO NORTHERN PART OF THE
REGION COULD SEE THE PRECIPITATION START OUT AS RAIN THEN SWITCH
TO A MIX BEFORE FINALLY ALL SNOW. SNOWFALL AMOUNTS ARE EXPECTED TO
BE SMALL. HIGH TEMPERATURES TODAY WILL RANGE FROM THE UPPER 30S IN
THE SOUTHEASTERN HALF OF THE REGION TO THE LOWER 40S IN THE
NORTHWESTERN HALF. TONIGHT WILL BE DRY ACROSS THE REGION WITH
CLEARING SKIES AND TEMPERATURES DROPPING IN TO THE 20S.
&&
.UPDATE...
ISSUED AT 138 PM EDT SAT MAR 29 2014
BULK OF SNOW/RAIN HAS SHIFTED EAST OF THE FORECAST AREA. BAND OF
HEAVIER PRECIP HAS FINALLY LOST ITS PUNCH BUT RADAR TRENDS SUGGEST
ANOTHER ONE TRYING TO TAKE SHAPE IN DEFORMATION ZONE FROM TOLEDO
TO CELINA OHIO. SPORADIC REPORTS HAVE COME IN WITH SPOTS THAT
RESIDE UNDER THESE BANDS SEEING A QUICK INCH OF SNOW IN AN HOUR ON
GRASSY SURFACES....INCLUDING FT WAYNE AIRPORT AND VAN WERT. WILL
HAVE TO WATCH PUTNAM/ALLEN COUNTY OHIO AREA WHERE INTENSITIES SEEM
TO BE RAMPING UP QUICKLY. RADAR/MODELS TRENDS SUGGEST THIS SHOULD
SHIFT EAST OVER THE NEXT COUPLE OF HOURS.
WILL ADJUST GRIDS TO REFLECT PRECIP TRENDS. ALSO TEMPS STILL LOOK
GOOD WITH STEADY OR EVEN SLOWLY RISING TRENDS NOTED ONCE THE
PRECIP ENDS. CLOUDS WILL BE SLOW TO DEPART BUT WILL SLOWLY ERODE
FROM NW TO SE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 138 PM EDT SAT MAR 29 2014
WITH PRECIP ISSUES NOW OUT OF THE WAY AT BOTH SITES FOCUS WILL BE
ON TIMING OF DEPARTURE OF LOW CLOUDS AND RETURN OF VFR CONDITIONS.
WESTERN EDGE OF THE RAIN/SNOW SHIELD CLEARED KFWA OVER THE PAST 20
MINUTES WITH LITTLE MORE THAN SOME DRIZZLE/VRY LGT RAIN LEFT IN
ITS WAKE. VSBYS WILL REMAIN MVFR DUE TO FOG...BUT CIGS WILL REMAIN
THE BIGGER ISSUE SITTING AROUND 1000 TO 1500 FT. A LOW RISE IN
CIGS IS EXPECTED...FIRST AT KSBN WHERE CIGS WILL COME UP TO 2500
TO 3000 FT LATER THIS AFTERNOON. SLOWER PROGRESS OF LOW CLOUDS
EXPECTED AT KFWA GIVEN PROXIMITY OF SFC LOW TO THE SE. HOWEVER
THEY WILL CATCH UP WITH TIME. RECENT RUC DATA HAD A GOOD HANDLE ON
CLOUD COVER AND FOLLOWED CLOSELY THROUGH TONIGHT. ONCE THE CLOUDS
DEPART VFR CONDITIONS WILL PREVAIL INTO TOMORROW.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1207 PM EDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 1022 AM EDT SAT MAR 29 2014
A LOW PRESSURE SYSTEM WILL BE PASSING THROUGH THE SOUTHEASTERN
UNITED STATES TODAY AND THE CENTER WILL MOVE TO THE WASHINGTON
D.C. AREA BY TOMORROW MORNING. THIS SYSTEM WILL PASS SOME
PRECIPITATION THROUGH THE REGION TODAY IN THE FORM OF RAIN IN THE
FAR SOUTH...MIX OF RAIN AND SNOW IN THE CENTRAL AREAS...AND MAINLY
SNOW IN THE NORTH. AREAS IN THE CENTRAL TO NORTHERN PART OF THE
REGION COULD SEE THE PRECIPITATION START OUT AS RAIN THEN SWITCH
TO A MIX BEFORE FINALLY ALL SNOW. SNOWFALL AMOUNTS ARE EXPECTED TO
BE SMALL. HIGH TEMPERATURES TODAY WILL RANGE FROM THE UPPER 30S IN
THE SOUTHEASTERN HALF OF THE REGION TO THE LOWER 40S IN THE
NORTHWESTERN HALF. TONIGHT WILL BE DRY ACROSS THE REGION WITH
CLEARING SKIES AND TEMPERATURES DROPPING IN TO THE 20S.
&&
.UPDATE...
ISSUED AT 1159 AM EDT SAT MAR 29 2014
PRECIP SHIELD FROM THE SOUTH AND MESO BANDING THAT HAS BEEN A PAIN
THIS MORNING IN SOME SPOTS...WERE FINALLY COMING TOGETHER AND
SHOULD PERSIST INTO THE AFTERNOON IN E/SE PORTIONS. LOCATIONS
WHERE THE HEAVIEST BAND HAS SET UP HAVE SEEN VSBYS OF 1/4 TO 1/2
MILE AND UPWARDS OF AN INCH OR SO OF SNOW ON GRASSY AREAS. HAVE
DECIDED TO GO WITH RAIN AND SNOW MIX INTO THIS AFTERNOON AS
VARIABLE INTENSITY OF PRECIP WITH MAINLY SNOW IN THE MORE INTENSE
BANDS AND A MIX OF RAIN/SNOW AT ONSET AND DURING LIGHTER PERIODS.
WHILE ZONES AND GRIDS WILL COME BACK WITH SOME AREAS SEEING 1 TO 2
INCHES...THIS WILL BE SOMEWHAT DECEIVING SINCE ROADS SHOULD
REMAIN WET AND THESE HIGHER AMOUNTS WILL ONLY OCCUR IN THE HEAVIER
SNOW BANDS. THE MAIN BAND OF INTEREST AS OF WRITING THIS WAS
LOCATED FROM NW JAY COUNTY THROUGH DECATUR TO NEAR PAULDING OHIO
WHERE VSBYS ARE LIKELY LOW AT TIMES.
AS FOR NW AREAS...ANY PRECIP WILL QUICKLY WIND DOWN OVER THE NEXT
COUPLE HOURS. AREA OF CLEARING WAS TRYING TO WORK SOUTH ACROSS WI
AND NW MI WITH SKIES STILL HOPEFULLY CLEARING OUT SOME TO ALLOW
FOR TEMPS HEADING TOWARDS 40. WILL LEAVE TEMP FORECAST ALONE FOR
NOW.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 433 AM EDT SAT MAR 29 2014
ATTN THIS PD FOCUSED ON IMPRESSIVE SW DISTURBANCE OVR WRN IA EARLY
THIS MORNING AND ITS SEWD AMPLIFICATION TWD THE MID ATL COAST BY SUN
AFTN.
00Z GUIDANCE SPECTRUM IN VRY GOOD AGREEMENT W/HANDLING/EVOLUTION OF
THIS SYS THROUGH THE PD. HWVR SUBSTANTIAL LWR MS VALLEY CONVN AND
ASSOCD/MCV OVR WRN MS WILL CERTAINLY SQUASH BTR NWD MSTR RTN WELL
S/E OF CWA CONFINES TDA AND ILLUSTRATED QUITE WELL BY DWINDLING
SUCCESSIVE RUC SOLUTIONS. WHILE MID LVL CIRC INVOF DEEPENING SYS
ALOFT IS IMPRESSIVE...SUBSTANTIAL LL DRY ENTRAINMENT ALG SRN
PERIPHERY OF SE CANADA POLAR RIDGE XPCD. THIS WILL OBVIOUSLY BE
DETRIMENTAL TO NW/NRN EXTENT OF PRECIP SHIELD AND BORNE OUT IN TIME
HGT CROSS SECTIONS/POINT SNDGS WHICH SUGGEST MORE OF A VIRGA BOMB
AND POTENTIAL BUST ALTOGETHER. THUS IN LIGHT OF SHRINKING IMPLIED
HIGHRES CONSENSUS PRECIP RATES POTENTIAL SNOWFALL IMPACTS OVR
SRN/SERN CWA LOOK MINIMAL. WILL IN THE LEAST TRUNCATE NWRN EXTENT OF
MENTIONABLE POPS FURTHER AND ADJUST FOR PREFERRED TIMING.
OTRWS PER PROGRESSIVE NATURE OF FLW PATTN ALOFT AND UPSTREAM
EXTRAPOLATED SYS MOVEMENT WILL DROP PRIOR POP MENTION OVR FAR EAST
THIS EVENING.
&&
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 433 AM EDT SAT MAR 29 2014
THERE ARE SURE SIGNS THIS UPCOMING WEEK OF A MILDER PATTERN...A
PATTERN THAT HAS SEEMINGLY EVADED THE AREA FOR THE PAST 4 MONTHS.
UPPER LEVEL RIDGING SHOULD INCREASE OVER THE REGION MONDAY IN ADVANCE
OF A SHORTWAVE MOVING NORTHEAST. GIVEN GFS AND ECMWF 850 MB FCST
TEMPS OF A SOLID 10C AND LITTLE REMAINING SNOW COVER...HIGHS SHOULD
BE ABLE TO TOP 60 DEGREES OVER NEARLY ALL AREAS. THESE MILD
TEMPERATURES ARE WELL SUPPORTED BY THE 00Z GFS MEX. AFTER
MONDAY...ADDITIONAL SHORTWAVES WILL ENSUE...ACCOMPANIED BY WET
WEATHER. FAVORED THE ECMWF DURING THE REST OF THE WEEK. THE ECMWF
HAS BEEN CONSISTENT WITH THE MASS FIELDS NEXT WEEK. IN ADDITION...
INCURSIONS OF GULF MOISTURE INTO THE AREA BY THE MIDDLE OF THE WEEK
WILL BRING THE POTENTIAL FOR RAIN WEDNESDAY THROUGH FRIDAY. CONCERN
FOR FLOODING GIVEN SATURATED GROUNDS...LIMITED VEGETATION AND
ADDITIONAL RAIN. A GROUND CORE SOIL SAMPLE HERE AT THE OFFICE LAST
NIGHT YIELDED NO FROZEN GROUND DOWN TO 14 INCHES WITH SATURATED
SOILS. WILL HOLD OFF WITH A HYDRO OUTLOOK FOR NOW...BUT A FRONT
SHOULD UNDULATE OVER THE AREA AS SHORT WAVES PASS. AFTER MONDAY...
KEPT TEMPERATURES NEAR NORMAL...BUT HIGHS COULD STILL TOP 60 DEGREES
AFTER MONDAY AS REFLECTED BY THE ECMWF IF THE FRONT MOVES BACK
NORTH.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 630 AM EDT SAT MAR 29 2014
NARROWING PCPN SHIELD OVR SE IL/SW IN ASSOCD W/APCH OF AMPLIFYING SW
ROLLING SEWD OUT SRN IA LOOKS TO BE MAKING A BEELINE FOR KFWA
TERMINAL BY DAYBREAK AND LINES UP EXCEEDINGLY WELL W/06Z LOCAL WRF.
THUS WILL STAND PAT W/PRIOR 06Z ISSUANCE. BRIEF PD OF IFR CONDS PSBL
TIMED W/CRUX OF SHRT DURATION MESOBAND BTWN 13-16Z ALTHOUGH PRECIP
INTENSITY STILL APPEARS TO BE OF INSUFFICIENT INTENSITY TO PROVIDE
AN ACCUMULATION ON HARD GROUND SFCS. OTRWS GENERAL MVFR CIG
RESTRICTIONS TO PERSIST UNDERNEATH FNTL INVERSION ALOFT INTO MID
AFTN BFR DEEP SUBSIDENT DRYING DVLPS IN WAKE OF DEPARTING MID LVL
TROUGH.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&
$$
UPDATE...FISHER
SYNOPSIS...LOTHAMER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1252 PM CDT SAT MAR 29 2014
.SYNOPSIS...
ISSUED AT 324 AM CDT SAT MAR 29 2014
AN UPPER LEVEL SHORTWAVE WITH SEVERAL EMBEDDED COMPACT VORT MAXIMA
WAS EVIDENT ON SATELLITE WV IMAGES MOVING THROUGH CENTRAL IA AND
WESTERN MO AT 07Z. AREA RADARS INDICATED A FEW WEAK ECHOES IN THE
LIFT AHEAD OF THIS FEATURE FROM SW WI ALONG THE MS RIVER TO W
CENTRAL IL. AREA OBSERVATIONS HAVE YET TO INDICATE ANY PRECIPITATION
REACHING THE GROUND FROM THESE WEAK RETURNS. AN INVERTED TROUGH AT
THE SURFACE...REACHING FROM THE CENTRAL IL INTO EAST CENTRAL
IA...WAS PROVIDING ENOUGH LOW LEVEL CONVERGENCE TO KEEP THE
WIDESPREAD STRATUS THAT NEVER LEFT THE AREA YESTERDAY IN PLACE. THE
00Z KDVN SOUNDING SHOWED AN ASSOCIATED SHALLOW LAYER OF MOISTURE
TRAPPED JUST BELOW AN INVERSION AND WEDGE OF DRY AIR ABOVE 900 MB.
UPSTREAM...A LARGE UPPER LOW WAS OFF THE BC COAST WITH A DOWNSTREAM
RIDGE AXIS MOVING THROUGH THE NORTHERN ROCKIES. AHEAD OF THIS UPPER
RIDGE...HIGH PRESSURE AT THE SURFACE REACHED FROM NEB INTO NORTHERN
MN. UNDER THIS RIDGE...SKIES WERE MAINLY CLEAR AND THE MUCH DRIER
AIRMASS FEATURED DEWPOINTS IN THE TEENS AND 20S...CONTRASTING TO THE
UPPER 20S TO LOWER 30S CURRENTLY OVER THE FORECAST AREA.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 324 AM CDT SAT MAR 29 2014
MAIN CHALLENGE CENTERS ON HOW FAST CLOUDS WILL CLEAR TODAY AND THE
IMPACT ON TEMPERATURES IN THE SHORT TERM. THE ADVANCING UPSTREAM
UPPER RIDGE AND DEEPENING AND PHASING OF THE DOWNSTREAM TROUGH OVER
THE OHIO VALLEY TODAY WILL RESULT IN A DEVELOPING MORE FAVORABLE
SUBSIDENCE REGIME THAN YESTERDAY. HOWEVER...THIS APPEARS TO BE A
SLOW PROCESS...AND MAY NOT RESULT IN ANY SIGNIFICANT CLEARING UNTIL
AFTERNOON.
AT THE SURFACE...A DEEPENING LOW PRESSURE SYSTEM RIDING NORTHEAST
THROUGH KY AND TN WILL IS SHOWN KEEPING AT LEAST A WEAK CYCLONIC
CURVATURE IN THE SURFACE PRESSURE FIELD EXTENDING NORTHEAST INTO
EASTERN IA UNTIL MIDDAY. THE ASSOCIATED WEAK LOW LEVEL CONVERGENCE
AND TRAPPED MOISTURE BELOW THE LINGERING INVERSION ALOFT...WILL KEEP
THE STRATUS HOLDING IN PLACE OVER MOST THE FORECAST AREA THIS
MORNING. THE BACK EDGE OF THE CLOUDS...CURRENTLY SLOWLY ADVANCING
E-SE ACROSS N CENTRAL AND FAR WESTERN IA WILL LIKELY COME TO A HALT
OVER CENTRAL IA INTO EASTERN IA THIS MORNING. FORECAST MODELS
CONTINUE TO STRUGGLE WITH THIS...AND AT THIS TIME ONLY THE RAP 900
MB RH FIELD SEEMS TO HAVE A GOOD HANDLE ON THIS TREND. WILL THUS KEEP
MOSTLY CLOUDY SKIES GOING THROUGH THE MORNING...THEN TRANSITION TO
MOSTLY SUNNY BY AFTERNOON AS THE SURFACE AND UPPER LEVEL RIDGE MOVE
OVERHEAD BRINGING SUBSIDENCE AND DRIER AIR. ACCOUNTING FOR THIS
DELAYED WARMING...AND WEAK MIXING UNDER THE RIDGE...HAVE HELD HIGH
TEMPERATURES AT THE LOWER END OF GUIDANCE...FROM THE MID 40S NORTH
TO LOWER 50S SOUTH.
TONIGHT...SKIES WILL START OUT CLEAR WITH ADVANCING HIGH CLOUDS
FOLLOWING PASSAGE OF THE UPPER RIDGE AXIS TOWARD MORNING. AT THE SURFACE...
INITIALLY LIGHT WINDS WILL TURN SOUTHERLY AND INCREASE TO AT LEAST 5
TO 10 KTS TOWARD MORNING AS A TROUGH MOVES INTO THE PLAINS. THIS
WOULD SUPPORT AN INITIAL COOL-DOWN AFTER SUNSET...THEN STEADY TO
POSSIBLY EVEN RISING TEMPERATURES TOWARD SUNRISE. WITH MOST MODELS
OVERALL TRENDING TOO MOIST IN THE LOWER LEVELS...HAVE GONE CLOSER TO
THE BETTER INITIALIZING ECMWF WITH ITS LOWER DEWPOINTS IN THE 20S
BEFORE THE RETURN FLOW SETS UP. THIS POINTS TOWARD LOWER MINS THAN
MOS...AND HAVE GONE WITH LOWS FROM THE MID 20S EAST TO LOWER 30S IN
THE FAR SOUTHWEST.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 324 AM CDT SAT MAR 29 2014
MILD WITH A FAST MOVING DISTURBANCE MONDAY...THEN FAVORABLE SETUP
FOR SIGNIFICANT TO HEAVY PRECIPITATION MID TO LATE NEXT WEEK.
OVERVIEW...INITIALIZATION AND VERIFICATION AVERAGE WITH STILL QUESTIONS
ON PHASING OF PACIFIC ENERGY ARRIVING NEXT FEW DAYS. AGAIN POOR BL
ISSUES THAT ARE OFF BY 3-5 DEGREES FOR BOTH T AND T/D THAT MOS OR
OTHER ALGORITHMS ARE HAVING PROBLEMS HANDLING. TREND IS FOR A DEEPER
TROUGH INTO THE PACIFIC SW BY TUESDAY WHICH IS A GOOD REGIME FOR
MODERATE TO HEAVY PRECIPITATION...MOSTLY RAIN WITH STALLED FRONT
TO OUR SOUTH FOR PROLONGED UPGLIDE. VARIANCES CONTINUE WITH HI-RES ECMWF
BY FAR THE FURTHEST NORTH. RUN TO RUN TRENDS AND VARIANCES SUPPORTS
A MIX OF THE UKMET/GFS /GEM-NH AND TO DISREGARD THE HI-RES ECMWF.
TRENDS ARE FOR NORTH PORTIONS TO SEE AT LEAST A FEW PERIODS OF A
MIX OF RAIN AND WET SNOW WHICH WILL TAKE ANOTHER 24 HOURS TO BETTER
ASCERTAIN. THIS 2 TO 3 DAY EVENT WEDNESDAY INTO FRIDAY WILL BE THE
HEAVIEST PRECIPITATION EVENT...WIDESPREAD 1 TO 2 PLUS INCH AMOUNTS
SINCE LAST FALL. CONDITIONS OF THIS TYPE CONTINUE TO SUGGEST WILL
HELP REPLENISH THE MODESTLY DRY SOILS AND PREPARE THE GROUND FOR
SPRING.
SUNDAY...EXPECT MODERATE BL MIXING AND MODERATE SOUTHERLY WINDS OF UP
TO 15 TO 25+ PH IN THE AFTERNOON. TRENDS STILL SUPPORT HIGHS IN LOWER
TO MIDDLE 60S WITH AFTERNOON RH VALUES FALLING BELOW 50 PERCENT TO
LOCALLY NEAR 40 PERCENT. THIS INDICATES GFDI VALUES INTO VERY HIGH
CATEGORY FOR SEVERAL HOURS IN THE AFTERNOON...MAINLY WEST OF THE
MISSISSIPPI RIVER DUE TO LITTLE TO NO GREENING OF VEGETATION. THIS
WILL REMAIN IN THE HWO PRODUCT. SUNDAY NIGHT...SOUTH WINDS OF 10 TO
20 MPH TO MAKE FOR THE MILDEST NIGHT IN MANY MONTHS DESPITE FAIR SKIES
WITH LOWS IN THE MID TO UPPER 40S....TO AROUND 50F SOUTH.
MONDAY...NEXT VIGOROUS AND FAST MOVING STORM SYSTEM SIMILAR TO YESTERDAY/S.
IS SLIGHTLY SLOWER...KEEPING MID CHANCE POPS WITH SHOWERS AND ISOLATED
MAINLY PM STORMS. WINDS WILL BE STRONGER ALLOWING FOR LOWER PM DEWPOINTS.
MID LEVEL SHOWERS AND ISOLATED STORMS WITH BASES AOA 6K AGL. LOW FREEZING
LEVEL STILL SUGGESTS NON-SEVERE STORMS WITH SOME PEA HAIL POSSIBLE AS
ANY STORMS WOULD FIRE OVER CWA IN MID/LATE PM HOURS. RAISED HIGHS BY
2-3 DEGREES INTO THE MID/UPPER 60S. WINDS MID DAY SHOULD BECOME QUITE
WINDY APPROACHING WIND ADVISORY CRITERIA OF 20 TO 30 MPH WITH GUSTS
TO AROUND 40 MPH. RH VALUES SHOULD FALL TO AROUND 50 PERCENT THAT MAY
SUPPORT NEAR VERY HIGH CONDITIONS FOR FIRE WEATHER BUT SHOWERS/STORMS
SHOULD AMELIORATE A BIT ALONG WITH HIGHER RH VALUES. MONDAY NIGHT...SLIGHTLY
DELAYED TIMING OF COOL FRONTAL PASSAGE INTO MID/LATE EVENING AND GUSTY
NW WINDS TO LIMIT COOLING BY MORNING. THIS SUGGESTS MINS NEAR GUIDANCE
BLEND...OR UPPER 20S FAR NW TO MIDDLE 30S FAR SE SECTIONS.
TUESDAY...LITTLE CHANGE TO CURRENT FORECAST. COOLER AND MOSTLY FAIR
SKIES WITH HIGHS MOSTLY OF 45 TO 50 DEGREES AND LIGHT NE WINDS AHEAD
OF NEXT...LARGE...SLOW MOVING AND QUITE STRONG UPPER DISTURBANCE AND
DEEP TROUGH MOVING EAST FROM CALIFORNIA. TUESDAY NIGHT...INCREASING
CLOUDS STILL SUGGEST LOWS TO OCCUR NEAR OR BEFORE MIDNIGHT....THEN
RISING TOWARD MORNING WITH CLOUDS RAIN AND INCREASING EAST WINDS.
LOCATIONS NORTH OF I-80 MAY SEE WITH EVAPORATIVE COOLING A MIX OF
SNOW BY MORNING...OR JUST A WET SNOW. THIS REMAINS A POOR CONFIDENCE
ON MIXED PRECIPITATION NORTH SECTIONS. THIS QUESTION SHOULD BE
RESOLVED NEXT 12-24 HOURS. LOCAL TOOLS DO SUPPORT SOME ACCUMULATIONS
MAY OCCUR ON EXPOSED SURFACES ATTM BUT AREA TEMPERATURES AT OR
SLIGHTLY ABOVE FREEZING TO LIMIT IMPACTS ON ROADWAYS.
WEDNESDAY THROUGH FRIDAY...PROLONGED PERIODS OF CLOUDY...COLD AND EPISODES
OF RAIN OR MOSTLY RAIN WITH A RISK OF A MIX NORTH SECTIONS OR EVEN
A WET SNOW BY FRIDAY AS SYSTEM MOVES EAST. HIGHS MOSTLY IN THE 40S
WITH LOWS IN THE 30S. REVIEW OF LOCAL FORECAST AREA TOOLS INDICATE
1 TO LOCALLY NEAR 2 INCHES OF RAIN OR MOSTLY RAIN OVER THIS PERIOD
REMAINS ON TRACK. THIS SYSTEM IS SLOWING DOWN WHICH MAY ALLOW FOR
EVEN MORE MOISTURE AND MAY RESULT IN EVEN SLIGHTLY HEAVIER AMOUNTS
OF RAIN AND EVEN A WET SNOW AS OPEN GULF MOISTURE HAS MORE TIME TO
POOL AHEAD OF THE FRONT. THIS SYSTEM BEARS CLOSE WATCHING DUE TO
ITS STRENGTH...CURRENT TRACK TO THE FORECAST AREA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT MAR 29 2014
HIGH PRESSURE OVER WESTERN IOWA WILL MOVE EAST AND SHOULD BE OVER
EASTERN IL BY SUNDAY MORNING. LOW PRESSURE WILL DEVELOP OVER THE
CENTRAL HIGH PLAINS TONIGHT. AN AREA STRATUS WITH BASES IN THE 2
TO 3KFT RANGE WAS OVER SOUTHEAST IOWA AND ADJOINING AREAS OF
MISSOURI AND ILLINOIS. THE STRATUS WAS MOVING SOUTH AND SHOULD
MOVE OUT OF THE AREA EARLY THIS AFTERNOON. A NARROW BAND OF CU
WITH BASES MAINLY ABOVE 3KFT WAS ALSO LOCATED OVER EASTERN IOWA
FROM WEST OF KDBQ SOUTH THROUGH KFFL AND WAS SUPPORTED BY WEAK LOW
LEVEL CONVERGENCE. AS THE HIGH PRESSURE BUILDS IN AND WITH LOSS OF
HEATING LATE THIS AFTERNOON THE CU SHOULD DISSIPATE. FOR THE
OVERNIGHT HOURS VFR CONDITIONS WITH LIGHT WINDS VEERING TO THE
SOUTHEAST ARE EXPECTED. MID-MORNING SUNDAY GUSTY SOUTH WINDS ARE
EXPECTED TO DEVELOP OVER EASTERN IOWA.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...SHEETS
SHORT TERM...SHEETS
LONG TERM...NICHOLS
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS CARIBOU ME
513 PM EDT SAT MAR 29 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK SLOWLY SOUTH OF THE AREA TONIGHT THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AT THE START OF THE PERIOD THE MAJOR MODELS ARE SHOWING THE NEXT
SYSTEM TO AFFECT OUR AREA CENTERED OVER THE CNTRL PORTIONS OF THE
NC/VA BORDER...WITH A WARM FRONT EXTENDING NORTH TO THE SW COAST
OF MAINE. THE MODEL INDICATE THAT THE LOW IS STILL DYNAMIC AT THIS
POINT...BUT SHOWING THAT THE UPPER LEVEL LOW IS STARTING TO BECOME
VERTICALLY STACKED WITH THE SURFACE LOW...THE BEGINNING PROCESS OF
BECOME COLD CORE. BY MRNG THE LOW MOVES NE TO THE NJ
COAST...PRECIP SPREADS ACROSS ERN MAINE INTO NRN MAINE. PCPN WILL
BE SNOW...WITH SLEET AND FREEZING RAIN MIXED IN ACROSS THE
INTERIOR DOWNEAST AND EAST CNTRL MAINE. AT THIS TIME ALL MODELS
SHOWING A CLOSED LOW AT 500MB AND THE SFC LOW NEARLY VERTICALLY
STACKED. BY THE END OF THE PERIOD...THE BULK OF THE PCPN MOVES
EAST INTO NEW BRUNSWICK...THE LOW DRIFTS NORTH ALONG THE NJ COAST
TO JUST SOUTH OF LONG ISLAND. THE UPPER LOW AND SFC LOW WILL BE
VERTICALLY STACKED. THE GFS...GEM...AND ECMWF SHOW A NEW LOW IN
THE ERN GULF OF MAINE THAT WILL BECOME THE NEW PRIMARY LOW FOR
THIS SYSTEM AS IT TRACKS TOWARD NEW BRUNSWICK.
LOADED THE HRRR MIN TEMP FOR THE OVRNGT...GEM MAX TEMP FOR
TOMORROW. INTERPOLATED FROM MIN TO MAX FOR HRLY TEMPS. USED A
BLEND OF NAM/GFS/GEM/ECMWF FOR HRLY DP/SKY/WND/POP. ADDED 15
PERCENT TO WINDS FOR GUSTS OVER LAND...25 PERCENT OVER WATERS.
LOADED NAWAVE 4 FOR SEAS IN THE COASTAL WATERS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
A VERTICALLY STACKED SURFACE/UPPER LOW WILL BEGIN TO MOVE SLOWLY
NORTHEAST SUNDAY NIGHT. A NEARLY STATIONARY FRONTAL BOUNDARY WILL
EXTEND NORTHEAST FROM THE SURFACE LOW. ISENTROPIC LIFT AND
OVERRUNNING IN THE VICINITY OF THE FRONT WILL SUPPORT PRECIPITATION
ACROSS THE FORECAST AREA SUNDAY NIGHT. HOWEVER...THE PROXIMITY OF
THE FRONT TO THE COAST REMAINS UNCERTAIN. HAVE BASED THE FORECAST
ON A SLOWER MOVEMENT OF THE SURFACE LOW AND THE FRONT REMAINING
CLOSER TO THE COAST WHICH WILL KEEP MORE EXTENSIVE PRECIPITATION
ACROSS THE FORECAST AREA. HIGH PRESSURE NORTH OF MAINE WILL
CONTINUE TO PROVIDE LOW LEVEL COLD AIR ACROSS THE FORECAST AREA
SUNDAY NIGHT INTO MONDAY. HOWEVER...WARMER AIR ALOFT WILL KEEP A
WINTRY MIX ACROSS MUCH OF THE FORECAST AREA SUNDAY NIGHT. A WINTRY
MIX WILL PERSIST ACROSS NORTHERN AND CENTRAL PORTIONS OF THE
FORECAST AREA SUNDAY NIGHT...WITH RAIN TRANSITIONING TO A WINTRY
MIX ACROSS DOWNEAST AREAS. WINTER STORM WARNINGS WILL REMAIN IN
EFFECT ACROSS NORTHERN AREAS SUNDAY NIGHT...WITH WINTER WEATHER
ADVISORIES ACROSS CENTRAL AREAS AND INTERIOR DOWNEAST PORTIONS OF
THE FORECAST AREA. HAVE HELD WITH THE SLOWER MOVEMENT OF THE
SYSTEM MONDAY...WHICH WILL KEEP LIGHT PRECIPITATION ACROSS THE
FORECAST AREA. ACROSS NORTHERN AREAS EXPECT EXPECT A LIGHT WINTRY
MIX...WITH A WINTRY MIX TRANSITIONING TO RAIN ACROSS CENTRAL AND
DOWNEAST AREAS. THE SURFACE/UPPER LOW WILL MOVE EAST MONDAY NIGHT
WHILE HIGH PRESSURE SLOWLY BUILDS SOUTH WITH DECREASING RAIN/SNOW
SHOWER CHANCES ACROSS THE FORECAST AREA. A SLIGHT CHANCE OF
SHOWERS COULD PERSIST DOWNEAST TUESDAY WITH THE EXITING LOW WHILE
HIGH PRESSURE BUILDS ACROSS NORTHERN MAINE. TEMPERATURES WILL BE
AT SLIGHTLY BELOW NORMAL LEVELS MONDAY/TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
LOW PRESSURE WILL BE MOVING AWAY TUESDAY NIGHT AS A RIDGE OF HIGH
PRESSURE BUILDS IN FROM THE WEST. THIS WILL BRING DRY AND RELATIVELY
MILD WEATHER TUESDAY NIGHT INTO WEDNESDAY. A WEAK TROUGH MAY MOVE
THROUGH ON THURSDAY BRINGING SOME CLOUDS AND PERHAPS LIGHT SHOWERS.
OTHERWISE, THE DAY SHOULD REMAIN MOSTLY CLOUDY. HIGH PRESSURE SHOULD
THEN BUILD IN BRINGING DRIER AND SEASONABLY MILD CONDITIONS ON
FRIDAY. GOING INTO THE WEEKEND, LOTS OF UNCERTAINTY REGARDING
WHETHER OR NOT A BLOCKING RIDGE OVER EASTERN CANADA CAN MAINTAIN THE
DRY WEATHER. THE GFS KEEPS CONDITIONS DRY WHILE THE ECMWF BRINGS A
TROUGH OF LOW PRESSURE THROUGH WITH A CHANCE FOR SOME RAIN OR SNOW
SHOWERS. IN THE FORECAST WILL HAVE LOW CHANCE FOR RAIN OR SNOW
SHOWERS NEXT WEEKEND. CURRENTLY DOES NOT LOOK LIKE ANY MAJOR STORMS
ARE EXPECTED THROUGH NEXT WEEKEND, AND TEMPERATURES WILL BE NEAR
NORMAL WHICH WILL BE CONSIDERABLY MILDER THAN THE VERY COLD
CONDITIONS WE HAVE HAD IN MARCH.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
NEAR TERM: DETERIORATING CONDITIONS SOUTH TO NORTH AS THE LOW
MOVES INTO THE AREA. MVFR CONDITIONS BHB...ALL OTHER SITES VFR TO
START THE PERIOD THIS EVENING. BY 9PM IFR CONDITIONS BHB IN
RAIN...BGR RAIN BCMG MXD. IFR CONDITIONS MOVE INTO
HUL...PQI...CAR...FVE AFT 3AM...PCPN SNOW BCMG MXD AT HUL TOMORROW
AFTN. IFR CONDITION WILL REMAIN ACROSS THE AREA THROUGH THE END OF
THE PERIOD. PCPN TYPE SN FOR FVE...SN MAY MIX WITH PL BRIEFLY IN
AFTN IN PQI AND CAR.
SHORT TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION
SUNDAY NIGHT INTO EARLY MONDAY...WITH MVFR/IFR CONDITIONS LATER
MONDAY. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE
REGION MONDAY NIGHT. OCCASIONAL MVFR CONDITIONS COULD PERSIST
ACROSS DOWNEAST AREAS EARLY TUESDAY. OTHERWISE...VFR CONDITIONS
ARE EXPECTED ACROSS THE REGION TUESDAY. VFR CONDITIONS ARE EXPECTED
ACROSS THE REGION WEDNESDAY. VFR CONDITIONS ARE EXPECTED ACROSS
NORTHERN AREAS THURSDAY...WITH OCCASIONAL MVFR CONDITIONS POSSIBLE
DOWNEAST.
&&
.MARINE...
NEAR TERM: THE LOW WILL TRANSIT SLOWLY SOUTH OF OF THE GULF OF
MAINE. TODAYS TRACK IS FARTHER SOUTH THAN WAS PREVIOUS FORECASTED.
WINDS STILL CALL FOR MARGINAL GALE FORCE WINDS FOR TOMORROW. WILL
CONTINUE THE GALE WATCH.
SHORT TERM: MARGINAL GALE CONDITIONS ARE POSSIBLE SUNDAY NIGHT
INTO EARLY MONDAY NIGHT WHICH COULD REQUIRE GALE WARNINGS.
VISIBILITIES WILL BE REDUCED IN RAIN SUNDAY NIGHT INTO EARLY
MONDAY NIGHT...WITH LINGERING RAIN/SNOW SHOWERS POSSIBLE LATER
MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
A FLOOD WATCH CONTINUES FOR DOWNEAST MAINE SUNDAY THROUGH MONDAY
AFTERNOON. THE PRECIPITATION ASSOCIATED WITH THE UPCOMING STORM
WILL LIKELY FALL MAINLY AS RAIN OR FREEZING RAIN IN THESE AREAS,
ESPECIALLY ALONG THE COAST. TOTAL LIQUID PRECIPITATION AMOUNTS OF
UP TO 3 INCHES ARE EXPECTED. IN ADDITION TO THIS RAIN...TEMPERATURES
WILL REMAIN NEAR OR ABOVE FREEZING THROUGH SUNDAY ADDING SNOWMELT
TO THE EQUATION. THE SNOWPACK IN THESE AREAS IS HIGHLY VARIABLE,
RANGING FROM AROUND 6 INCHES ALONG THE COAST TO 2 FEET OR MORE IN
THE INTERIOR. THERE IS 2 TO 4 INCHES OF WATER CONTAINED IN THE
PACK ALONG THE COAST WITH 6 TO 8 INCHES FURTHER INLAND. WHILE THE
DEEPER SNOW WILL BE ABLE TO ABSORB SOME OF THE RAIN...MUCH OF IT
WILL BECOME RUNOFF IN ADDITION TO THE SNOWMELT. THIS MEANS
DOWNEAST AREAS COULD POTENTIALLY SEE 4 INCHES OR MORE OF TOTAL
RUNOFF. RIVERS WILL LIKELY RISE SUBSTANTIALLY AND POTENTIALLY
CAUSE RIVER ICE TO BREAK UP...ESPECIALLY IN THOSE PLACES WHERE
THE ICE COMPLETELY FLUSHED OUT IN JANUARY (MEANING THE ICE THERE
NOW IS RELATIVELY WEAK). FOR THOSE RIVER STRETCHES THAT ARE ICE
FREE...ICE COVER UPSTREAM MAY BREAK UP AND COLLECT DOWNSTREAM. IN
ADDITION TO THE POTENTIAL FOR ICE JAMS, THIS AMOUNT OF RAINFALL
AND RUNOFF WILL LIKELY LEAD TO PONDING OF WATER ON ROADWAYS AND
MINOR FLOODING OF LOW-LYING POOR DRAINAGE AREAS. IN ADDITION,
TIDAL LOCATIONS SUCH AS BANGOR WILL HAVE TO BE WATCHED CLOSELY
AROUND THE TIME OF HIGH TIDE. THE CURRENT OFFICIAL NATIONAL
WEATHER SERVICE FORECAST FOR THE PENOBSCOT RIVER AT BANGOR BRINGS
THE GAUGE WITHIN 1 FOOT OF FLOOD STAGE WITH HIGH TIDE SUNDAY
MORNING. PERSONS WITH INTERESTS ALONG WATERWAYS OR IN FLOOD-PRONE
LOCATIONS ACROSS HANCOCK...WASHINGTON AND SOUTHERN PENOBSCOT
COUNTIES SHOULD STAY TUNED FOR ADDITIONAL INFORMATION ON THIS
SYSTEM.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING FROM 6 AM SUNDAY TO 8 AM EDT MONDAY FOR
MEZ001-002.
WINTER STORM WARNING FROM 2 AM SUNDAY TO 8 AM EDT MONDAY FOR
MEZ003>006-010.
WINTER WEATHER ADVISORY FROM 2 AM SUNDAY TO 8 AM EDT MONDAY
FOR MEZ011-015>017-031-032.
FLOOD WATCH FROM SUNDAY MORNING THROUGH MONDAY AFTERNOON FOR
MEZ015>017-029-030.
MARINE...GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
ANZ050>052.
&&
$$
NEAR TERM...NORTON
SHORT TERM...NORCROSS
LONG TERM...BLOOMER
AVIATION...NORTON/NORCROSS
MARINE...NORTON/NORCROSS
HYDROLOGY...NORTON
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
554 PM CDT Sat Mar 29 2014
.SHORT TERM: (Through Late Tonight)
Issued at 320 PM CDT Sat Mar 29 2014
Pesky stratus seems to be both clearing and eroding at a snails
pace this afternoon and has a done number on the temperatures.
Present indications based on satellite trends and the RAP which
has handled the low clouds best, is that areas generally along and
east of the MS River will see clouds into early evening with
clearing from mid-late evening. Otherwise the expansive NE-SW high
pressure system currently extending from WI into TX will slide
east across the region tonight with the axis centered thru SE MO
and southern IL at 12z. The slow clearing trend of the clouds
along with light winds overnight across the SE third of the CWA
has prompted me to add a mention of fog overnight.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 320 PM CDT Sat Mar 29 2014
It finally looks like the warm-up will commence on Sunday. Heights
aloft that begin rising tonight in the wake of the departing upper
trof, will continue to rise on Sunday while the surface high
retreats and low level southerly flow and warm advection get
underway. There should be no low clouds to deal with a just some
thin high clouds filtering across the region. The current forecast
leveraging the warmer temperatures looks right on the mark and no
changes were made. The warmer temps combined with low afternoon
RH values and increasing southerly winds support an elevated fire
danger threat across central and east central MO, which will be
highlighted in the HWO.
Continued southerly low level flow on Sunday night will lead to
"milder" min temperatures and a slow return in low level moisture.
The aforementioned expansive surface high and its southern extent
will initially have a profounded effect on trajectories and delay
quality moisture return. However mid level moisture won`t be an
issue and this along with the eastern edge of steeper mid level
lapse rates spreads into central MO just before daybreak on
Monday. These ingredients along with the leading edge of forcing
aloft associated with an upstream trof, suggests potential for
some high-based scattered showers/thunderstorms and hence have
added some slight chance pops.
The week ahead looks especially active. The migratory upper trof
partly responsible for the slight chance pops late Sunday night
will move across the region Monday afternoon and early evening
spreading height falls and cooling aloft along with a plume of
steep mid level lapse rates. This combined with a gradual increase
in low level moisture and forcing should be sufficient for
scattered elevated showers/thunderstorms within the warm sector, moving
through central and northeast MO during the morning gradually
dwindling in coverage during the afternoon as they move east. By
the time the cold front moves through the area Monday night,
forcing aloft appears to have outrun the front and boundary layer
moisture and hence instability are quite weak. I suspect anything
that might be able to develop with be quite spotty and just have a
slight chance pop.
The most active period will be late Tuesday night into Thursday.
The front that moves through Monday night will move back north
and waver across the region. The warm sector air mass south of
this boundary will become quite unstable thanks to continued
northward return of quality Gulf moisture and the presence of
steep mid level lapse rates, and with a strong low level jet
evolving there will be good elevated instability and forcing north
this boundary. The models differ quite a bit on the position of
the next formidable migratory upper trof and the position of
attendant surface low(s) and this boundary. While all the guidance
supports a stormy period, the more northern position which has
been consistently advertised by the ECMWF would lead to a much
more volatile set-up.
Glass
&&
.AVIATION: (For the 00z TAFs through 00z Sunday Evening)
Issued at 546 PM CDT Sat Mar 29 2014
Specifics for KCOU: Although light fog is possible tonight across
the region, KCOU experienced sufficient daytime mixing to limit
the overnight fog potential. Winds start to increase by 12z due to
the tightening pressure gradient between a surface high to the
southeast and a developing low to the northwest.
Specifics for KSTL, KSUS, KCPS, KUIN: Stratus was slow to clear
today and nearly clear skies with light winds are expected
overnight. The combination of limited daytime mixing and good
radiational cooling conditions will probably lead to light fog
formation, especially near and east of the Mississippi River.
Winds start to increase by 12z due to the tightening pressure
gradient between a surface high to the southeast and a developing
low to the northwest.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
324 PM CDT Sat Mar 29 2014
.SHORT TERM: (Through Late Tonight)
Issued at 320 PM CDT Sat Mar 29 2014
Pesky stratus seems to be both clearing and eroding at a snails
pace this afternoon and has a done number on the temperatures.
Present indications based on satellite trends and the RAP which
has handled the low clouds best, is that areas generally along and
east of the MS River will see clouds into early evening with
clearing from mid-late evening. Otherwise the expansive NE-SW high
pressure system currently extending from WI into TX will slide
east across the region tonight with the axis centered thru SE MO
and southern IL at 12z. The slow clearing trend of the clouds
along with light winds overnight across the SE third of the CWA
has prompted me to add a mention of fog overnight.
Glass
.LONG TERM: (Sunday through Next Saturday)
Issued at 320 PM CDT Sat Mar 29 2014
It finally looks like the warm-up will commence on Sunday. Heights
aloft that begin rising tonight in the wake of the departing upper
trof, will continue to rise on Sunday while the surface high
retreats and low level southerly flow and warm advection get
underway. There should be no low clouds to deal with a just some
thin high clouds filtering across the region. The current forecast
leveraging the warmer temperatures looks right on the mark and no
changes were made. The warmer temps combined with low afternoon
RH values and increasing southerly winds support an elevated fire
danger threat across central and east central MO, which will be
highlighted in the HWO.
Continued southerly low level flow on Sunday night will lead to
"milder" min temperatures and a slow return in low level moisture.
The aforementioned expansive surface high and its southern extent
will initially have a profounded effect on trajectories and delay
quality moisture return. However mid level moisture won`t be an
issue and this along with the eastern edge of steeper mid level
lapse rates spreads into central MO just before daybreak on
Monday. These ingredients along with the leading edge of forcing
aloft associated with an upstream trof, suggests potential for
some high-based scattered showers/thunderstorms and hence have
added some slight chance pops.
The week ahead looks especially active. The migratory upper trof
partly responsible for the slight chance pops late Sunday night
will move across the region Monday afternoon and early evening
spreading height falls and cooling aloft along with a plume of
steep mid level lapse rates. This combined with a gradual increase
in low level moisture and forcing should be sufficient for
scattered elevated showers/thunderstorms within the warm sector, moving
through central and northeast MO during the morning gradually
dwindling in coverage during the afternoon as they move east. By
the time the cold front moves through the area Monday night,
forcing aloft appears to have outrun the front and boundary layer
moisture and hence instability are quite weak. I suspect anything
that might be able to develop with be quite spotty and just have a
slight chance pop.
The most active period will be late Tuesday night into Thursday.
The front that moves through Monday night will move back north
and waver across the region. The warm sector air mass south of
this boundary will become quite unstable thanks to continued
northward return of quality Gulf moisture and the presence of
steep mid level lapse rates, and with a strong low level jet
evolving there will be good elevated instability and forcing north
this boundary. The models differ quite a bit on the position of
the next formidable migratory upper trof and the position of
attendant surface low(s) and this boundary. While all the guidance
supports a stormy period, the more northern position which has
been consistently advertised by the ECMWF would lead to a much
more volatile set-up.
Glass
&&
.AVIATION: (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 201 PM CDT Sat Mar 29 2014
MVFR cigs slow to clear out of taf sites, so backed off on
scattering clouds out especially for KUIN and STL metro area tafs.
Otherwise, winds to remain from the north this afternoon, then
become light and variable tonight as clouds scatter out. Some
concern about light fog tonight, but confidence is low at this
time. By Sunday morning, surface ridge to move off to the east
allowing winds to pickup from the south around 10kts.
Specifics for KSTL:
MVFR cigs slow to clear out of taf sites, so backed off on
scattering clouds out til after 21z. Otherwise, winds to remain from
the north this afternoon, then become light and variable by 09z.
Some concern about light fog tonight, but confidence is low at
this time so left mention out for now. By 14z Sunday morning,
surface ridge to move off to the east allowing winds to pickup
from the south around 10kts.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1232 PM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CDT SAT MAR 29 2014
A WARM DRY SURGE IS READY TO GO TODAY. THE SOURCE REGION FOR THIS
WARM AIR IS THE SOUTH CENTRAL ROCKIES AND THE RAP MODEL SHOWS
SOUTHWEST WINDS DRAWING THIS AIR THROUGH THE FCST AREA...GENERALLY
ALONG AND WEST OF HIGHWAY 83.
NEARLY FULL SUN IS EXPECTED AS THE NEAREST CIRRUS IS OVER THE TETONS
AND BIG HORNS. THE GFS HOWEVER SHOWS CIRRUS DEVELOPING THIS AFTN OFF
THE LARAMIE RANGE AND THIS IS SUPPORTED BY THE ECM WHICH GENERALLY
HAS GOOD SKILL WITH HIGH CLOUDS. STILL...THE SUPER ENSEMBLE
TEMPERATURE FORECAST PRODUCES HIGHS IN THE UPPER 60S TO NEAR 70
WHICH WERE MARKED UP TO LOWER 70S IN MANY AREAS GIVEN THE VERY DEEP
MIXING SHOWN BY THE RAP MODEL.
SOUTHWEST WINDS INCREASE TO 15 TO 25 MPH AND A BLEND OF THE
NAM...RAP AND GFS WIND GUST PRODUCTS PRODUCED WIND GUSTS TO 35 MPH.
FOR TONIGHT...THE THERMAL RIDGE FORECAST TO MOVE OFF THE ROCKIES
TODAY CONTINUES TO BUILD ACROSS THE FORECAST AREA. LOWS SHOULD ONLY
FALL TO THE MID 30S TO LOWER 40S WITH DECOUPLING POSSIBLE OVER
SOUTHWEST NEB FOR LOCALLY COOLER LOWS GIVEN THE VERY DRY
ENVIRONMENTAL CONDITIONS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 354 AM CDT SAT MAR 29 2014
UPPER LEVEL RIDGE TO BREAK DOWN ON SUNDAY AS AN UPPER TROUGH
ADVANCES NORTHEAST FROM THE GREAT BASIN TOWARD THE CENTRAL PLAINS.
WITH THE APPROACH OF THE UPPER TROUGH...CYCLOGENESIS WILL COMMENCE
OFF THE LEE OF THE ROCKIES WITH SUBSEQUENT DEEPENING OF THE
SURFACE LOW THROUGH THE DAY. THE LOW SHOULD REMAIN FOCUSED ALONG
OR NEAR THE CHEYENNE RIDGE SUNDAY...WHICH AS IT DEEPENS WILL ALLOW
FOR BACKED SURFACE WINDS TO THE SOUTHEAST. DESPITE HIGH
TEMPERATURES WELL INTO THE 70S ACROSS THE CENTRAL SANDHILLS AND
POINTS SOUTH /MAYBE A FEW 80S AS WELL/...THIS BACKED SURFACE FLOW
WILL ALLOW FOR A GREATER MOISTURE TRAJECTORY OFF THE GULF...RATHER
THAN THE DIRECT DOWNSLOPE FLOW FROM SOUTH CENTRAL COLORADO. TD/S
ARE ANTICIPATED TO RISE SOME...BUT STEEP LOW-MID LEVEL LAPSE RATES
WILL CONTINUE TO MIX DRY ALOFT TO THE SURFACE...EFFECTIVELY
KEEPING MINIMUM RELATIVE HUMIDITIES NEAR CRITICAL THRESHOLDS.
ATTM...SOUTHWEST NEBRASKA AND THE CENTRAL SANDHILLS ARE EXPECTED
TO SEE RH IN THE 15 PERCENT RANGE BY EARLY AFTERNOON...BUT SHOULD
INCREASE SLIGHTLY TOWARD EVENING. EXTENDING FROM THE LOW WILL BE
AN INVERTED SURFACE TROUGH...WHICH WOULD PRODUCE A WEAKNESS IN THE
WIND FIELD. AVAILABLE MODEL GUIDANCE DOES NOT SUPPORT RFW WIND
CRITERIA ATTM ACROSS THE CENTRAL SANDHILLS. HOWEVER STRONG MIXING
DUE TO VERY STEEP LOW-MID LEVEL LAPSE RATES WOULD ALLOW FOR
DOWNWARD MOMENTUM TRANSFER. GUSTS IN EXCESS OF 25 MPH ARE
INDICATED BY BUFR SOUNDINGS WHERE THE RH MINIMUM EXISTS /SOUTHWEST
NEBRASKA. AN ADDITIONAL RED FLAG WARNING IS ANTICIPATED FOR
SUNDAY. FOR THIS WILL ISSUE A FIRE WEATHER WATCH WHERE CONFIDENCE
IS HIGH /FIRE ZONES 210 AND 219/ ON SEEING RFW CRITERIA. STEEP
LAPSE RATES ASSOCIATED WITH AN EASTWARD ADVECTING EML WILL
OVERSPREAD MUCH OF THE CENTRAL HIGH PLAINS LATE AFTERNOON/EARLY
EVENING RESULTING IN WEAK INSTABILITY ALOFT. HIGH BASED CONVECTION
IS POSSIBLE...IF STORMS FIRE...SURFACE TD/T SPREADS OF 40 DEGREES
OR WOULD SUGGEST THE POTENTIAL FOR STRONG TSTM OUTFLOW WITH LITTLE
RAINFALL. NOT ANTICIPATING A LAL OF 6...BUT TROUBLESOME
NONETHELESS. ADDITIONAL CONVECTION IS POSSIBLE INTO THE EVENING
HOURS AS THE TROUGH AND ASSOCIATE COLD FRONT CROSS THE CENTRAL
PLAINS...BUT ONCE AGAIN MOISTURE INITIALLY IS LACKING...SO WETTING
RAINS WILL BE ISOLATED AT BEST. BEYOND SUNDAY EVENING THE FORECAST
GETS TRICKY...ESPECIALLY WHEN CONSIDERING THE POTENTIAL IMPACTS OF
THE IMPENDING LATE WINTER STORM. ATTM...THERE/S SUFFICIENT
AGREEMENT IN THE MODELS TO SUGGEST RAIN CHANGING OVER TO SNOW
EARLY ON MONDAY ACROSS OUR NORTHERN ZONES AS THE MAIN TROUGH DRAGS
MODIFIED ARCTIC AIR SOUTH INTO THE CWA. IN TERMS OF
IMPACTS...TEMPERATURES AT LEAST INITIALLY WILL REMAIN IN THE LOWER
30S...AND GIVEN THE WARM WEEKEND...SNOW MAY STRUGGLE TO ACCUMULATE
ON PAVED SURFACES...ESPECIALLY TRUE IF THE BRUNT OF THE SNOW
OCCURS AFTER SUNRISE. BUT...WINDS ON THE BACKSIDE OF THE EJECTING
SFC LOW WILL BE EXTREMELY GUSTY...WITH THE POTENTIAL OF 35 MPH
GUSTS /OR HIGHER/ ACROSS NORTH CENTRAL NEBRASKA ON MONDAY.
VISIBILITY WILL BE SIGNIFICANTLY REDUCED WHEN SNOW IS FALLING.
WINTER HEADLINES ARE POSSIBLE ON MONDAY ACROSS NORTHERN
NEBRASKA...WITH THE GREATEST IMPACTS FOCUSED ALONG AND NORTH OF
THE HIGHWAY 20 CORRIDOR. WILL INCREASE POPS IN THIS AREA INTO THE
LOW LIKELY RANGE WITH THIS FORECAST ISSUANCE. BEYOND MONDAY...THE
PATTERN REMAINS ACTIVE THROUGHOUT THE ENTIRE NEXT WORK WEEK AS
QUASI-ZONAL FLOW SLOWLY TRANSITIONS TO SOUTHWESTERLY WITH THE
APPROACH OF THE NEXT LONGWAVE WESTERN CONUS TROUGH. THIS PATTERN
FAVORS SEASONAL...TO SLIGHTLY BELOW AVERAGE TEMPERATURES THROUGH
AT LEAST NEXT THURSDAY. IN ADDITION...AS THE NEXT UPPER TROUGH
DIGS ACROSS THE GREAT BASIN MID-WEEK...A COLD FRONT WILL REMAIN
FIXED SOUTH OF THE CWA...WHICH WILL GENERALLY PROVIDE FOR UPSLOPE
FLOW AND CONSIDERABLE CLOUDINESS EACH DAY. PRECIPITATION WILL
REMAIN IN THE FORECAST AS WELL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1232 PM CDT SAT MAR 29 2014
VFR CONDITIONS WILL CONTINUE ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA THROUGH THE TAF PERIOD. ONE CONCERN HOWEVER IS THE WIND.
SOUTHWEST WINDS WILL GUST TO AROUND 25 KTS FOR THE REMAINDER OF THIS
AFTERNOON AND INTO THE EVENING BEFORE BECOMING LIGHT AND VARIABLE
TONIGHT. SUNDAY MORNING...A WARM FRONT WILL LIFT NORTH ACROSS
SOUTHWEST NEBRASKA...BUT NOT QUITE MAKE IT TO KVTN BY 30/18Z. CLOUDS
WILL THICKEN AND LOWER TOWARD SUNDAY AFTERNOON FOR BOTH
TERMINALS...BUT VFR WILL BE MAINTAINED.
&&
.FIRE WEATHER...
ISSUED AT 354 AM CDT SAT MAR 29 2014
THE RAP AND HRRR MODELS SHOW DEWPOINTS FALLING INTO THE TEENS TODAY.
THE MODEL CONSENSUS SHOWS SOUTHWEST WINDS INCREASING TO 15 TO 25 MPH
THIS AFTERNOON. A BLEND OF THE NAM...RAP AND GFS WIND GUST PRODUCTS
PRODUCED GUSTS TO 35 MPH THIS AFTERNOON ALSO.
THE SOURCE REGION FOR THIS DRY AIR IS THE SCNTL ROCKIES WHERE DEW
POINTS ARE CURRENTLY IN THE SINGLE DIGITS. THE MODELS PRODUCE
SOUTHWEST WINDS OFF THE ROCKIES TODAY WHICH WILL CARRY THIS DRY AIR
INTO THE FCST AREA WHILE TEMPERATURES RISE INTO THE LOWER 70S FOR RH
VALUES FALLING INTO THE SINGLE DIGITS.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
RED FLAG WARNING UNTIL 9 PM CDT /8 PM MDT/ THIS EVENING FOR
NEZ204-206-209-210-219.
FIRE WEATHER WATCH FROM SUNDAY AFTERNOON THROUGH SUNDAY EVENING
FOR NEZ210-219.
&&
$$
SHORT TERM...CDC
LONG TERM...JACOBS
AVIATION...DS
FIRE WEATHER...CDC
AREA FORECAST DISCUSSION
NWS ELKO NV
343 PM PDT SAT MAR 29 2014
.SYNOPSIS...A RAPIDLY DEVELOPING AREA OF LOW PRESSURE AND
ASSOCIATED COLD FRONT WILL BRING VALLEY RAIN AND SNOW TO THE
REGION TONIGHT THROUGH SUNDAY. A SMALL BREAK BETWEEN SYSTEMS
SUNDAY NIGHT BEFORE ANOTHER PACIFIC STORM SYSTEM IMPACTS THE
REGION MONDAY AFTERNOON THROUGH TUESDAY...BRINGING ANOTHER ROUND
OF VALLEY RAIN AND SNOW.
&&
.SHORT TERM...SATURDAY NIGHT THROUGH TUESDAY. CURRENT RUC ANALYSIS
INDICATES A RAPIDLY DEEPENING AREA OF LOW PRESSURE FROM EUREKA TO
ELY. THIS LOW PRESSURE IS PROGGED TO MOSTLY STAY STATIONARY AND
DEEPEN THROUGH THE NIGHT AS THE TEMPERATURE GRADIENT TIGHTENS. IN
ADDITION A DEEP PLUME OF PACIFIC MOISTURE IS STREAMING ACROSS
NORTHERN NEVADA...WITH RAIN ALREADY BREAKING OUT ACROSS HUMBOLDT
COUNTY. MODELS ARE ALL IN GOOD AGREEMENT BRINGING A WIDESPREAD
AREA OF .25 TO .50" OF PRECIPITATION OVER THE REGION OVER THE NEXT
24 HOURS...WITH HIGHER AMOUNTS ACROSS THE MOUNTAINS. THE FORECAST
CHALLENGE REMAINS WHEN WILL RAIN CHANGEOVER TO SNOW TONIGHT AND AT
WHAT ELEVATION WILL THE SNOW ACCUMULATE AT. IT LOOKS LIKE THE
VALLEYS OF HUMBOLDT COUNTY WILL REMAIN MOSTLY RAIN...WITH A MIX OF
RAIN AND SNOW TOWARDS THE END OF THE EVENT...BUT NO
ACCUMULATIONS. ACROSS ELKO COUNTY AND CENTRAL NEVADA THE CHANCE
FOR ACCUMULATING SNOW IS MUCH HIGHER...DUE TO HIGHER ELEVATIONS
AND THE BULK OF THE PRECIPITATION FALLING AFTER MIDNIGHT. LOOKS
LIKE RAIN WILL CHANGE OVER TO SNOW THIS EVENING ABOVE 5500FT
ACROSS NORTHERN ELKO COUNTY...WITH RAIN CHANGING OVER TO SNOW FROM
AUSTIN TO SPRING CREEK SOMETIME AFTER MIDNIGHT AS 1000-500MB
THICKNESS VALUES FALL BELOW 549DAM. 700MB FGEN FORCING PEAKS FROM
AUSTIN TO ELKO AROUND 9Z...BEFORE SLIDING INTO EASTERN ELKO AND
WHITE PINE COUNTIES BY SUNDAY MORNING. EXPECTING A MODERATE SNOW-
BAND TO DEVELOP ALONG THIS FGEN FORCING AS IT IS VERTICALLY
STACKED WITH A BROAD AREA OF 500-300MB UPPER LEVEL LIFT DUE TO A
DUAL-CORE JET STREAK CIRCULATION. THIS WILL LEAD TO VERY DEEP LIFT
AND A VERY FAVORABLE DENTRITIC GROWTH REGION...THUS EXPECTING HIGH
END ADVISORY SNOWFALL AMOUNTS ABOVE 6K WHERE IT WILL BE COLD
ENOUGH FOR 12 TO 1 SNOW RATIOS. BELOW 5500 FEET SURFACE TEMPS WILL
LEAD TO LOW RATIOS...THUS LOWER SNOWFALL AMOUNTS...BUT A SLUSHY
INCH COULD EVEN FALL IN ELKO. THE HIGHEST AMOUNTS OF SNOW IN
POPULATED AREAS ARE EXPECTED AT AUSTIN...EUREKA...SPRING
CREEK...AND ELY.
SUNDAY NIGHT THROUGH TUESDAY. SNOW TAPERS OFF DURING THE DAY ON
SUNDAY...BEFORE THE NEXT PACIFIC STORM REACHES THE AREA BY MONDAY
AFTERNOON. MODELS HAVE BEEN STRUGGLING WITH THIS SYSTEM...DUE TO
THE EVOLUTION OF TWO SEPARATE 500MB CIRCULATIONS. CONFIDENCE IS
STILL LOW IN HOW THIS SYSTEM WILL MATERIALIZE OVER THE REGION...BUT
WET SNOW IS PROBABLE MONDAY NIGHT INTO TUESDAY MORNING AS A
SURFACE LOW DEVELOPS OVER NORTHERN NEVADA AND 500MB HEIGHTS DROP
TO 546 DAM. THE BEST CHANCE FOR HEADLINE LEVEL SNOWFALL LOOKS TO
BE ACROSS NORTHERN NEVADA AT THIS TIME.
.LONG TERM...TUESDAY NIGHT THROUGH NEXT SATURDAY.
EMPHASIS ON SHORT TERM AND IMPACTS TO AVIATION, SO FEW CHANGES WERE
MADE TO THE LONG TERM GRIDS. LARGE COLD TROUGH LINGERS OVER THE
GREAT BASIN TUESDAY NIGHT AND WEDNESDAY, FOR UNSEASONABLY COLD
WEATHER FOR EARLY APRIL AND SCATTERED SNOW SHOWERS. ADDITIONAL SNOW
AMOUNTS DURING THIS TIME FRAME WILL BE LIGHT, WITH THE LARGEST
IMPACT BEING THE COLD. WITH 700 MB TEMPS NEAR -10C, AFTERNOON
TEMPERATURES WILL STRUGGLE INTO THE 40S WEDNESDAY, AND NW WINDS WILL
MAKE IT FEEL EVEN COLDER.
TEMPERATURES WILL MODERATE THURSDAY UNDER WEAK RIDGING, AHEAD OF THE
NEXT PACIFIC TROUGH. 12Z ECMWF BRINGS THIS PACIFIC TROUGH INLAND
INTO NEVADA IN A WEAKENED STATE ON FRIDAY, WITH SOME RAIN AND SNOW
SHOWERS. 12Z GFS MUCH FASTER AND MUCH WEAKER WITH THIS WAVE, IN FACT
MEDIUM RANGE SOLUTIONS OF GFS/ECMWF/GEM ARE IN MUCH DISAGREEMENT
STARTING ABOUT THURSDAY. SHOWED A GRADUAL WARMING TREND IN THE MAX
TEMP GRIDS FRIDAY AND SATURDAY, BUT CONFIDENCE IS LOW. BT
&&
.AVIATION...FOR THE 00Z TAFS...COMPLICATED TAF PACKAGE, WITH SNOW
AND WIND IMPACTING AVIATION OPERATIONS THROUGH THE NEXT 24 HOURS.
MODEL GUIDANCE AGREES THAT INCLEMENT WEATHER WILL OCCUR AT THE TAF
SITES, BUT DIFFER A BIT ON TIMING /WITH THE 12Z GFS A BIT SLOWER/ SO
WILL HOLD OFF ON TEMPO GROUPS UNTIL THE EVENT STARTS TO UNFOLD THIS
AFTERNOON/EVENING.
EXPECT DEGRADED CONDITIONS IN -RA TO BEGIN AT KWMC AROUND 00Z, AND
AT KEKO AROUND 03Z. EXPECTING -RA TO CHANGE TO -SN AT BOTH KWMC/KEKO
APPROXIMATELY 06Z TONIGHT, WITH VIS/CIG MOST LIKELY FALLING TO
IFR/CAT A LANDING MINIMUMS AT KEKO 06-15Z SUN. STRONG COLD FRONT WILL
REACH KWMC BY 09Z, AND KEKO BY 12Z, WITH STRONG NW WINDS GUSTING
30-35 KTS AND LIMITED VIS IN -SHSN. SINCE MOST OF THE SNOW IS
FALLING AT NIGHT AT KEKO, SOME ACCUMULATIONS ON KEKO RUNWAYS ARE
POSSIBLE 06-15Z SUN.
FURTHER SOUTH...CYCLOGENESIS EXPECTED NEAR KELY AFTER 00Z, WITH
STRONG SW/S WINDS GUSTING 30-40 KTS AT TIMES, AT LEAST THROUGH 06Z.
INCLUDED VCTS AT KELY THIS EVENING WITH INSTABILITY PRESENT. STRONG
COLD FRONT PASSAGE APPROXIMATELY 12-15Z SUN, WITH AGAIN STRONG NW
WINDS OF 20-35 KTS. ACCUMULATING SNOW MOST LIKELY AT KELY 12-18Z
SUN, WITH IMPACTS POSSIBLE ON KELY RUNWAYS.
AT KTPH...STRONG SW WINDS THIS AFTERNOON AT 20-30 KTS. COLD FRONT
ARRIVES AT KTPH AROUND 12Z SUN, WITH VERY STRONG NW WINDS FOLLOWING
ITS PASSAGE AT THE KTPH TERMINAL, GUSTING TO 40-45 KTS. LIMITED VIS
IN BRIEF -RASN MOST LIKELY AT KTPH 12-18Z SUN, BUT IMPACTS WILL BE
MUCH LESS HERE COMPARED TO THE OTHER TERMINALS. BT
&&
.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM PDT SUNDAY ABOVE 5500 FEET
FOR NORTHERN ELKO COUNTY...NORTHERN LANDER COUNTY AND NORTHERN
EUREKA COUNTY...SOUTHWESTERN ELKO COUNTY.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 5 PM PDT
SUNDAY ABOVE 6000 FEET FOR SOUTH CENTRAL ELKO COUNTY...SOUTHERN
LANDER COUNTY AND SOUTHERN EUREKA COUNTY...WHITE PINE COUNTY.
WIND ADVISORY UNTIL 8 PM PDT THIS EVENING FOR NORTHEASTERN NYE
COUNTY...WHITE PINE COUNTY.
WINTER STORM WARNING UNTIL 5 PM PDT SUNDAY FOR RUBY
MOUNTAINS/EAST HUMBOLDT RANGE.
WIND ADVISORY FROM 5 AM TO 5 PM PDT SUNDAY FOR NORTHWESTERN NYE
COUNTY.
&&
$$
95/99/99
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
659 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A MOISTURE LADEN STORM SYSTEM WILL IMPACT OUR REGION TONIGHT INTO
SUNDAY. THIS SYSTEM WILL PRODUCE A MIXTURE OF RAIN...SLEET AND
SNOW...WITH SOME ICE ACCUMULATION ACROSS PORTIONS OF EASTERN
VERMONT. HEAVY RAINFALL ACROSS SOUTHERN VERMONT...COMBINED WITH
MELTING SNOW WILL PRODUCE INCREASED HYDRO CONCERNS OVER THE
WEEKEND.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 648 PM EDT SATURDAY...SOME MINOR CHANGES WITH THIS
UPDATE...MAINLY TO SLOW START TIME OF PRECIPITATION BY A COUPLE OF
HOURS. PRECIPITATION HAS MADE IT AS FAR NORTH AS NORTH ADAMS IN
MASS. SHOULD SEE IT MOVE INTO PARTS OF SOUTHERN VERMONT OVER THE
NEXT 1-2 HOURS...CENTRAL VERMONT AROUND 9 PM...BURLINGTON AREA
AROUND 10 PM...AND ACROSS THE ENTIRE NORTH COUNTRY BY AROUND 11
PM. HEAVIEST PRECIP STILL APPEARS IT WILL FALL BETWEEN 06Z AND
12Z. VERTICAL TEMPERATURE PROFILES REMAIN VERY TRICKY WITH NEARLY
ISOTHERMAL PROFILE FROM THE SURFACE TO 825-MB CENTERED AROUND 0C.
DYNAMIC/EVAPORATIONAL COOLING SHOULD HELP TO COOL THE COLUMN AT
LEAST IN HEAVIER PRECIPITATION IN THE ADVISORY AREA AND ESPECIALLY
NORTHERN NEW YORK. ONE CAVEAT TO NOTE...LATEST RAP SOLUTIONS ARE
CONSIDERABLY WARMER AND WOULD FAVOR MORE RAIN OVER SNOW/SLEET FOR
MUCH OF VERMONT...BUT WILL KEEP FORECAST AS IS FOR NOW.
PREVIOUS DISCUSSION FROM 402 PM SATURDAY...
WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR MIXED PRECIPITATION
ACROSS ALL OF THE NORTH COUNTRY EXCEPT WESTERN RUTLAND COUNTY.
FLOOD WATCH REMAINS IN EFFECT FOR RUTLAND...WINDSOR...ORANGE...AND
WESTERN ADDISON COUNTIES FOR THE POTENTIAL OF MINOR RIVER FLOODING
FROM THE COMBINATION OF SNOW MELT...EXPECTED RAINFALL...AND
ASSOCIATED RIVER RISES AND ICE JAM THREAT.
THERE HAVE BEEN SOME INTERVALS OF SUNSHINE ACROSS SOUTHERN HALF OF
VERMONT THIS AFTERNOON...WHILE WHILE LOW CLOUDS HANGING ON ACROSS
MUCH OF THE NORTH. MEANWHILE...CLOUDS IN ADVANCE OF OUR NEXT LOW
PRESSURE SYSTEM ARE SPREADING INTO SOUTHERN AREAS...WITH
PRECIPITATION NOT FAR BEHIND. TEMPS ACROSS THE REGION IN THE UPPER
30S NORTH TO 40S SOUTH AND IN EASTERN VERMONT. LOWER DEWPOINTS TO
THE NORTH ACROSS QUEBEC...AND SOME OF THIS AIR WILL ADVECT SOUTH
INTO FORECAST AREA TONIGHT WITH LOW LEVEL NORTHERLY FLOW.
COMPLICATED TEMPERATURE PROFILE WILL RESULT IN A VARIETY OF
PRECIPITATION TYPES TONIGHT INTO SUNDAY...WITH PROBLEMS ENHANCED
BY FACT THAT THERE IS PLENTY OF MOISTURE AVAILABLE...SO SOME
GENEROUS QPF AMOUNTS ANTICIPATED FOR MUCH OF THE NORTH COUNTRY.
A COMPLEX STORM SYSTEM DEVELOPING OVER THE LOWER OHIO VALLEY WILL
TRACK EAST TO THE DELMARVA REGION TONIGHT...THEN NORTHEAST TO A
POSITION OFF CAPE COD BY MONDAY. THIS MOISTURE LADEN SYSTEM WILL
BRING A SIGNIFICANT AMOUNT OF PRECIPITATION TO THE NORTH COUNTRY
TONIGHT INTO SUNDAY...WITH QPF AMOUNTS GENERALLY FROM 0.75 INCHES
TO 1.5 INCHES. SOME LOCALLY HIGHER AMOUNTS POSSIBLE SOUTHERN
VERMONT...AND LOWER AMOUNTS OVER SAINT LAWRENCE VALLEY. THERE WILL
ALSO BE A VARIETY OF PRECIPITATION TYPES TO DEAL WITH...AS
FORECAST SOUNDINGS CONTINUE TO SHOW A COMPLEX THERMAL PROFILE WITH
SURFACE TEMPS NEAR OR A BIT BELOW FREEZING AND A WARM LAYER ABOVE
FREEZING MOVING IN ALOFT. OVERALL...LATEST GUIDANCE SUGGESTS
LITTLE CHANGE FROM PREVIOUS MODEL RUN. BREAKING IT DOWN BY
AREAS...
ACROSS NORTHERN NEW YORK...PRECIP WILL BEGIN AS MAINLY SNOW THIS
EVENING...THEN MIX WITH SLEET OVERNIGHT THROUGH MID-DAY SUNDAY.
SNOW AND SLEET ACCUMULATIONS OF 3-7" WITH A FEW HIGHER AMOUNTS
POSSIBLE NORTHERN ADIRONDACKS.
FOR THE CHAMPLAIN VALLEY AND THE NORTHERN WESTERN SLOPES OF THE
GREENS...PRECIP BEGINS AS SNOW OR MIX THIS EVENING...THEN MOSTLY
SNOW/SLEET MIX OVERNIGHT BEFORE CHANGING TO RAIN BY MID-DAY
SUNDAY. SNOW AND SLEET ACCUMULATIONS OF 3-5" ARE EXPECTED.
ACROSS CENTRAL AND EASTERN VERMONT...PRECIP BEGINS AS
SNOW/SLEET/RAIN THIS EVENING...THEN MOSTLY SLEET AND FREEZING
DURING THE OVERNIGHT HOURS BEFORE CHANGING TO RAIN BY MID-DAY
SUNDAY. SNOW AND SLEET ACCUMULATIONS OF 2-5" ARE EXPECTED...ALONG
WITH A TENTH TO QUARTER INCH OF ICE ESPECIALLY ACROSS ELEVATIONS
FROM 1-2KFT.
FINALLY...ACROSS RUTLAND AND WINDSOR COUNTIES...PRECIP WILL REMAIN
MOSTLY RAIN WITH SOME MIX OF SLEET AND FREEZING RAIN ACROSS THE
HIGHER ELEVATIONS. THIS AREA WILL SEE THE MOST RAIN DURING THE
EVENT PRESENTING SOME HYDRO CONCERNS DUE TO ICE BREAKUP. SEE OUR
HYDRO SECTION BELOW FOR MORE INFO ON THAT.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 402 PM EDT SATURDAY...FOR SUNDAY NIGHT INTO MONDAY...WE WILL
HAVE TO WATCH FOR THE POSSIBILITY OF ANOTHER ROUND OF MIXED
PRECIPITATION. THIS DUE TO SHORTWAVE ROTATING AROUND THE SLOWLY
DEPARTING UPPER LOW. MODELS HAVE TRENDED FURTHER WEST WITH THE
UPPER LOW AND SHORTWAVE...SO CONFIDENCE INCREASING THAT WE WILL AT
LEAST SEE SOME LIGHT SLEET AND OR RAIN/FREEZING RAIN/DRIZZLE
SUNDAY NIGHT INTO MONDAY. GREATEST CHANCES WILL BE OVER EASTERN
ZONES DUE PROXIMITY WITH UPPER LOW. TEMPS MARGINAL FOR SNOW/RAIN
OR MIXED PRECIPITATION ONCE AGAIN. LOOK FOR LOWS SUNDAY NIGHT IN
THE MID 20S TO LOWER 30S AND HIGHS MONDAY NEAR 40. SLOW
IMPROVEMENT MONDAY NIGHT AS THE UPPER LOW EXITS TO THE EAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 325 PM EDT SATURDAY...DRY START TO THE PERIOD TUESDAY
BEFORE UPPER LVL TROUGH...ASSOCIATED WITH CLOSED SFC
LOW...TRAVELS FROM THE NRN GREAT LAKES NEWD NEAR JAMES BAY BY MID
WEDNESDAY. THIS LOW WILL HAVE A WEAK FRONTAL BOUNDARY DRAPED
SOUTH...WHICH WILL BRING LOW CHC OF SHOWERS TO THE NORTH COUNTRY
TUESDAY NGT INTO WEDNESDAY...AS THIS BOUNDARY WILL HAVE LIMITED
MOISTURE AND MAIN UPPER LVL ENERGY WILL BE FAR NORTH OF THE FA.
FOR ANY PRECIP THAT DOES OCCUR...TUESDAY NGT WILL SEE SOME
SNOW...BUT WARMING TEMPS ON WEDNESDAY WILL TRANSITION SN INTO RA
BEFORE TAPERING OFF.
ANOTHER SYSTEM APPROACHING FROM CENTRAL USA WILL BRING WARM FRONT
TO THE NE LATE THURSDAY INTO FRIDAY. GFS AND ECMWF DIFFER WITH
ECMWF PERSISTING WITH RIDGE. THIS WOULD KEEP THREAT OF PRECIP TO
OUR SOUTH THRU LATE FRIDAY. MUCH UNCERTAINTY FOR THE LATTER HALF
OF THE WEEK GOING INTO THE WKND.
TEMPS THROUGHOUT THE PERIOD WILL BE NEAR NORMAL WITH MAX TEMPS IN
THE 40S IN THE VALLEYS AND 30S IN THE MTNS. MIN TEMPS WILL BE IN
THE U20S-L30S IN THE VALLEYS AND UPPER TEENS TO L20S IN THE MTNS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
THROUGH 18Z SUNDAY...AS LOW PRESSURE APPROACHES FROM SW...WARM
FRONT WILL BRING MIXED PRECIP TO THE NORTH COUNTRY FROM S TO N
TONIGHT. WITH ONSET OF PRECIP...MVFR/IFR CONDITIONS EXPECTED
THROUGH SUNDAY MORNING. LLVL NORTHERLY FLOW WITH WARMING
SOUTHERLY FLOW ALOFT WILL LEAD TO VRB/CHANGING P-TYPE THROUGHOUT
THE NIGHT AND INTO SUNDAY. HEAVIEST PRECIP EXPECTED
OVERNIGHT...GENERALLY AFTER 06Z THROUGH 12Z. ANOTHER CONCERN WILL
BE GUSTY WINDS AS PRESSURE GRADIENT INCREASES OVERNGT.
KRUT EXPECTING MOSTLY RAIN EVENT...AS WARM AIR IS ABLE TO FILTER
IN THROUGHOUT THE COLUMN OF AIR. MVFR CONDITIONS EXPECTED WITH
NE-E FLOW ALLOWING FOR DOWNSLOPING/SLGTLY DRIER AIR IN LLVL.
WINDS WILL BCM GUSTY AROUND 20KTS AFTER 06Z.
KMPV WILL SEE MIX OF SNOW AND SLEET AROUND 00Z...WITH SOME
WARMING ALOFT OVRNGT ALLOWING FZRA TO MIX IN AFTER 06Z. FURTHER
WARMING INTO SUNDAY MORNING WILL LIKELY SEE MIX OF SLEET AND
FZRA. IFR CONDITIONS...ESP CIGS...SETTLE IN WITH PRECIP ONSET
THROUGH THE TAF PERIOD.
THE CPV WILL HAVE SLTLY WARMER TEMPS ALOFT ON THE ERN
SIDE...RESULTING IN -SNPL CHANGING TO FZRASNPL AT KBTV OVRNGT.
MIX CONTINUES WITH SOME LLVL WARMING PSBL AT KBTV WITH SNPLRA
SUNDAY MORNING. KPBG WILL BE COLDER WITH GENERALLY SN AND PL
EXPECTED. OVERNGT IFR CONDITIONS EXPECTED AT BOTH
SITES...IMPROVING TO MVFR SUNDAY MID-LATE MORNING.
KSLK/KMSS EXPECT MOSTLY SNOW...WITH SOME PL MIXING IN AT KSLK.
IFR CONDITIONS EXPECTED TO START BTWN 01Z AND 04Z AS COLDER AIR
KEEPS ONSET OF PRECIP AS SN...REDUCING VSBYS QUICKLY. LATE
MORNING/EARLY AFTN IMPROVEMENT TO MVFR WILL BE SLOW.
OUTLOOK 18Z SUNDAY THROUGH THURSDAY...
18Z SUNDAY THROUGH 00Z MONDAY...WIDESPREAD MVFR/IFR IN MIXED PCPN
AND/OR RAIN...TAPERING OFF IN COVERAGE AND INTENSITY FROM WEST TO
EAST AFTER 18Z. CONFIDENCE LOW ON EASTWARD PROGRESSION OF PCPN AS
SEVERAL MODELS KEEP MIXED PCPN OVER EASTERN TERMINALS WELL INTO
MONDAY.
00Z MONDAY TO 18Z MONDAY...TRENDING SLOWLY TO VFR FROM WEST TO
EAST AS LIGHT RAIN/SNOW TAPERS OFF. BEST SHOT AT CONTINUED LIGHT
PCPN AND MVFR/IFR AT ERN TERMINALS OF KMPV/KRUT. AGAIN...HIGHEST
CONFIDENCE OF BETTER FLIGHT CONDS AT NRN NY TERMINALS WITH
CONTINUED UNCERTAINTY FURTHER EAST.
18Z MONDAY THROUGH 00Z WEDNESDAY...VFR WITH HIGH PRESSURE.
00Z WEDNESDAY THROUGH 00Z THURSDAY...VFR ALTHOUGH SOME BRIEF
PERIODS OF MVFR POSSIBLE IN SCATTERED RAIN/SNOW SHOWERS AS COLD
FRONT CROSSES REGION.
00Z THURSDAY ONWARD...VFR W/MVFR PSBL LATE THURSDAY AS WARM FRONT
APPROACHES FROM SW...BRINGING PRECIP SOUTH TO NORTH.
&&
.HYDROLOGY...
AS OF 325 PM EDT SATURDAY...PRECIPITATION WILL BEGIN TO EDGE INTO
SOUTHERN VERMONT LATE THIS AFTN...PROGRESSING NORTHWARD
THROUGHOUT THE EVENING. THIS PRECIPITATION IS EXPECTED TO
CONTINUE THROUGH SUNDAY NIGHT...RESULTING IN OUR SOUTHERN
WATERSHEDS RECEIVING THE MOST RAINFALL ON THE ORDER OF 1-2
INCHES. AREAS FURTHER NORTH AND WEST WILL SEE MORE OF A MIXED
PRECIPITATION EVENT...WITH LESSER RAINFALL AMOUNTS.
WITH SOUTHERN WATERSHEDS RECEIVING MOSTLY RAIN...EXPECT SNOWPACK
TO ABSORB SOME OF THIS RAINFALL AS TEMPERATURES WILL GENERALLY BE
IN THE MID TO UPPER 30S THROUGHOUT THE EVENT...LEADING TO LIMITED
MELTING OF SNOWPACK. ONLY A FEW HUNDREDTHS OF AN INCH OF SNOW
WATER MELT PER HOUR EXPECTED ON TOP OF RAINFALL WILL RESULT IN
MODEST TO LOCALLY SHARP RISES IN EXCESS OF 4-5 FEET SUNDAY
MORNING/AFTERNOON. ENSEMBLE FORECASTS INDICATE NO RIVER FLOODING
EXPECTED....BUT WATER LEVEL RISES MAY BE MORE THAN SUFFICIENT TO
PRODUCE ICE MOVEMENT AND/OR BREAKUP ACROSS SCATTERED WATERSHEDS.
WILL KEEP FLOOD WATCH IN EFFECT FOR CENTRAL AND SOUTHERN VERMONT.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...WINTER WEATHER ADVISORY UNTIL 2 PM EDT SUNDAY FOR VTZ001>010-
012-016>019.
FLOOD WATCH THROUGH MONDAY MORNING FOR VTZ009>012-019.
NY...WINTER WEATHER ADVISORY UNTIL 2 PM EDT SUNDAY FOR NYZ026>031-
034-035-087.
&&
$$
SYNOPSIS...RJS
NEAR TERM...RJS/MUCCILLI
SHORT TERM...RJS
LONG TERM...KGM
AVIATION...KGM
HYDROLOGY...KGM
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
641 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER
JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE
REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA
TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE
WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 640 PM SATURDAY...MAIN QUESTION TONIGHT IS HOW TO BEST
HANDLE RAIN POTENTIAL. MAIN BAND OF PRECIPITATION HAS MOVED
OFFSHORE WITH ONLY SCATTERED SHOWERS NOW OCCURRING OVER THE
EASTERN NC. INITIAL THOUGHT WAS TO DECREASE POPS TO CHANCE AND
CALL FOR SCATTERED SHOWERS AT LEAST THROUGH THE EVENING HOURS.
EYING AREA OF SHOWERS/POSSIBLE THUNDERSTORMS OVER SOUTH CAROLINA
WHICH DEVELOPED IN REGION OF CLEARING EARLIER TODAY. THINK THIS
ACTIVITY WILL DECREASE IN COVERAGE/INTENSITY WITH LOSS OF HEATING
BY THE TIME IT WOULD ARRIVE OVER THE COASTAL PLAIN. THIS IS
DEPICTED IN THE LATEST RUN OF THE HRRR MODEL. LATE TONIGHT DRY
SLOTTING SHOULD END ANY CHANCE OF PRECIPITATION UNTIL LATER SUNDAY
WHEN THE UPPER LEVEL LOW MOVES THROUGH. USED A BLEND OF THE
ECMWF/MET MOS FOR LOWS WITH READINGS IN THE UPPER 40S/LOWER 50S
EXPECTED.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH 6 PM SUNDAY/...
AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION
DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO
OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP
LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF
SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES
WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER
NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID
50S WITH GUSTY W/WNW WINDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SAT...THE LONG TERM PORTION OF THE FORECAST CAN BE
SUMMARIZED AS DRYING OUT AND WARMING UP. MADE ONLY MINOR TWEAKS
TO THE POPS ENDING THE RAIN SUNDAY NIGHT. SURFACE/UPPER LOW AND
ASSOCIATED MOISTURE MOVE OFF TO THE NORTHEAST WITH RIDGING SURFACE
AND ALOFT BUILDING IN FROM THE WEST. RIDGING BEGINS TO BREAK DOWN
LATE IN THE WEEK AS AN UPPER LOW AND SURFACE COLD FRONT APPROACH
FROM THE WEST. THE COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT AND
CARRIED A LOW CHANCE POP FOR SHOWERS AND STORMS. DRYING OUT
SATURDAY WITH THE FRONT OFF THE COAST AND A SURFACE HIGH BUILDING
TO THE NORTHWEST. NORTHWEST FLOW ON MONDAY WILL DIMINISH AND
SLOWLY TRANSITION TO A WEST TO SOUTHWEST FLOW BY TUESDAY NIGHT AND
CONTINUE INTO FRIDAY. HIGHS THIS WEEK WILL CLIMB WELL INTO THE
70S ACROSS MOST INLAND AREAS BEGINNING TUESDAY AS WINDS BECOME
SOUTHERLY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /TONIGHT AND SUNDAY/...
AS OF 640 PM SATURDAY...SOME IFR CEILINGS ARE STILL BEING
REPORTED AT THE TAF SITES BUT THINK THE TREND IS FOR IMPROVEMENT
AS THE THREAT FOR WIDESPREAD PRECIPITATION IS OVER AND SOME DRYING
IS EXPECTED TO MOVE INTO THE AREA LATER THIS EVENING. BASED ON
UPSTREAM OBSERVATIONS AND TRENDS IN THE 12Z/18Z NAM FORECAST
SOUNDINGS WILL FORECAST CONDITIONS IMPROVING TO MVFR AND
CONTINUING FOR MUCH OF TONIGHT THEN A BRIEF PERIOD OF VFR
CONDITIONS AROUND 09Z DURING THE PEAK OF DRYING. AN UPPER LOW IS
FORECAST TO MOVE ACROSS NC SUNDAY. ASSOCIATED MOISTURE WILL LEAD
TO A RETURN TO MVFR CEILINGS 12-14Z WHICH WILL THEN PERSIST FOR
MUCH OF THE DAY. THERE COULD ALSO INTERMITTENT LIGHT RAIN OR
DRIZZLE AT TIMES. GUSTY SOUTHERLY WINDS TONIGHT WILL BECOME
WESTERLY ON SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SAT...IFR/MVFR CONDITIONS SUNDAY NIGHT WILL BECOME VFR
ON MONDAY AS MOISTURE EXITS TO THE NORTHEAST AND A SURFACE/UPPER
RIDGE BUILDS IN FROM THE WEST. NORTHWEST WINDS SUNDAY NIGHT AND
MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT AND CONTINUE
THROUGH THURSDAY. MODEL SOUNDINGS INDICATE LATE NIGHT/EARLY
MORNING STRATUS/FOG POSSIBLE EACH MORNING WITH VERY LIGHT WINDS
AND BOUNDARY LAYER MOISTURE.
&&
.MARINE...
SHORT TERM /TONIGHT AND SUNDAY/...
AS OF 640 PM SATURDAY...NO CHANGES TO PREVIOUS FORECAST THINKING
OTHER THAN TO EXTEND THE ADVISORIES FOR THE SOUNDS THROUGH EARLY
MONDAY. GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND HAVE ADDED THE
ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT WILL REMAIN IN
EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT 20 TO 25 KNOTS
FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE OREGON INLET TO
OCRACOKE LEG WHERE DIAMOND BUOY IS REPORTING GUSTS TO 35 KNOTS
AND DUCK IS INDICATING GUSTS TO 30 KNOTS. THESE WINDS SHOULD
SETTLE DOWN AFTER MIDNIGHT AS WINDS VEER TO MORE SW LATE. PER
LATEST NWPS WAVE MODEL...SEAS OF 9 TO 13 FEET WILL PREVAIL OVER THE
NORTHERN AND CENTRAL WATERS WITH GENERALLY 7 TO 10 FEET OVER
SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE WESTERLY FLOW
EXPECTED DURING THE DAY ON SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SAT...AN OVERALL IMPROVING TREND SEEN IN MARINE
CONDITIONS THROUGH THE LONG TERM. SURFACE/UPPER LOW WILL MOVE OFF
TO THE NORTHEAST SUNDAY NIGHT WITH SURFACE/UPPER RIDGE QUICKLY
BUILDING IN AND LINGERING FOR MOST OF THE WEEK. SMALL CRAFT
CONDITIONS WILL END FROM SOUTH TO NORTH MONDAY AND MONDAY NIGHT.
NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY WILL BECOME WEST TO
SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 AM EDT MONDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC/JME
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...JME/HSA/LEP
MARINE...CTC/JME/HSA
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
320 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE LATE TONIGHT. A SURFACE TROUGH WILL LINGER
JUST WEST OF THE AREA INTO MONDAY. WEAK HIGH PRESSURE BUILDS OVER THE
REGION MONDAY NIGHT AND TUESDAY. THE HIGH WILL MOVE SOUTH OF THE AREA
TUESDAY NIGHT AND WEDNESDAY. ANOTHER COLD WILL APPROACH THE AREA BY LATE
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM SATURDAY...BAND OF LIGHT TO MODERATE SHOWERS ACROSS
THE CENTRAL AND EASTERN PORTIONS OF THE CWA CURRENTLY. HRRR AND
RAP SHOWING DRY SLOTTING AND HAVE DROPPED POPS BACK TO HIGH CHANCE
OVER THE FAR WESTERN COUNTIES FOR THIS EVENING. LIKELY POPS WILL
CONTINUE OVER EASTERN AREAS THROUGH THE EVENING BEFORE DROPPING
EVERYWHERE LATE TONIGHT. INSTABILITY TODAY HAS BEEN LIMITED BY
SHOWERS AND CLOUDS AND HAVE KEPT JUST A SLIGHT CHANCE OF THUNDER
THRU THE EVENING AS SOME BREAKS HAVE DEVELOPED IN THE CLOUDS
FURTHER WEST OVER SOUTH CAROLINA AND SOUTHERN NORTH CAROLINA...BUT
WITH IT GETTING LATE IN THE DAY...AGAIN THINK THUNDER WILL BE
LIMITED. THINK COLD AIR ADVECTION WILL KICK IN LATE TONIGHT AND
FORECAST LOWS IN THE UPPER 40S AND LOWER 50S.
&&
.SHORT TERM /SUNDAY/...
AS OF 315 PM SATURDAY...WILL HAVE A BIT OF A LULL IN PRECIPITATION
DURING THE MORNING HOURS ON SUNDAY...BUT AS UPPER LOW CROSSES TO
OUR NORTH NEAR THE NORTH CAROLINA/VIRGINIA BORDER...THE STEEP
LAPSE RATES AND MODEST MOISTURE WILL LEAD TO A HIGH CHANCE OF
SHOWERS SUNDAY AFTERNOON. WITH GOOD COLD AIR ADVECTION...TEMPERATURES
WILL ONLY RECOVER ABOUT 5 TO 7 DEGREES AND WILL FOLLOW THE COOLER
NAM MOS GUIDANCE SUNDAY SHOWING HIGH TEMPERATURES IN THE LOW/MID
50S WITH GUSTY W/WNW WINDS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
AS OF 3 PM SAT...THE LONG TERM PORTION OF THE FORECAST CAN BE
SUMMARIZED AS DRYING OUT AND WARMING UP. MADE ONLY MINOR TWEAKS
TO THE POPS ENDING THE RAIN SUNDAY NIGHT. SURFACE/UPPER LOW AND
ASSOCIATED MOISTURE MOVE OFF TO THE NORTHEAST WITH RIDGING SURFACE
AND ALOFT BUILDING IN FROM THE WEST. RIDGING BEGINS TO BREAK DOWN
LATE IN THE WEEK AS AN UPPER LOW AND SURFACE COLD FRONT APPROACH
FROM THE WEST. THE COLD FRONT WILL MOVE THROUGH FRIDAY NIGHT AND
CARRIED A LOW CHANCE POP FOR SHOWERS AND STORMS. DRYING OUT
SATURDAY WITH THE FRONT OFF THE COAST AND A SURFACE HIGH BUILDING
TO THE NORTHWEST. NORTHWEST FLOW ON MONDAY WILL DIMINISH AND
SLOWLY TRANSITION TO A WEST TO SOUTHWEST FLOW BY TUESDAY NIGHT AND
CONTINUE INTO FRIDAY. HIGHS THIS WEEK WILL CLIMB WELL INTO THE
70S ACROSS MOST INLAND AREAS BEGINNING TUESDAY AS WINDS BECOME
SOUTHERLY.
&&
.AVIATION /19Z SATURDAY THROUGH THURSDAY/...
SHORT TERM /TONIGHT AND SUNDAY/...
AS OF 115 PM SATURDAY...UNPLEASANT FLYING CONDITIONS WILL BE
EXPERIENCED...ESPECIALLY DURING THE FIRST HALF OF THE TAF PERIOD.
A POTENT LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK FROM THE
WEST...BRINGING MODERATE TO HEAVY SHOWERS ACROSS THE SITES THIS
AFTERNOON. BY LATE THIS AFTERNOON/EVENING...ACTIVITY SHOULD
DIMINISH AS A DRY SLOT/DRIER AIR WORKS INTO THE REGION. WINDS WILL
STILL BE GUSTY FROM THE SW THROUGH THE AFTERNOON. CIGS WILL BE
EXTREMELY TRICKY WITH A MIX BAG IN TERMS OF CRITERIA CURRENTLY
BEING OBSERVED ACROSS THE CAROLINAS. GIVEN THIS...FEEL THE MOST
PREDOMINANT AREA OF IFR/LIFR WILL BE ACROSS THE WESTERN TAF SITES
WHILE THE COASTAL SITES MAY SEE MORE IN THE WAY OF MVFR/IFR CIGS.
FEELING IS THAT LOW CIGS BEING OBSERVED ACROSS THE SOUTH AND WEST
WILL ADVECT INLAND THIS AFTERNOON. HOWEVER...DRIER AIR WILL MOVE
IN...PERHAPS LIMITING THE DURATION OF LOW CEILINGS. CONDITIONS
SHOULD DRAMATICALLY IMPROVE THROUGH THE EARLY MORNING HOURS AS THE
MID LEVEL LOW PROPAGATES NORTH OF THE ARE AND WINDS SHIFT TO THE
NW. ANTICIPATE CEILING TO RISE AND NW WINDS TO REMAIN GUSTY
THROUGHOUT TOMORROW.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SAT...IFR/MVFR CONDITIONS SUNDAY NIGHT WILL BECOME VFR
ON MONDAY AS MOISTURE EXITS TO THE NORTHEAST AND A SURFACE/UPPER
RIDGE BUILDS IN FROM THE WEST. NORTHWEST WINDS SUNDAY NIGHT AND
MONDAY WILL BECOME WEST TO SOUTHWEST TUESDAY NIGHT AND CONTINUE
THROUGH THURSDAY. MODEL SOUNDINGS INDICATE LATE NIGHT/EARLY
MORNING STRATUS/FOG POSSIBLE EACH MORNING WITH VERY LIGHT WINDS
AND BOUNDARY LAYER MOISTURE.
&&
.MARINE...
SHORT TERM /TONIGHT AND SUNDAY/...
AS OF 320 PM SATURDAY...GUSTY SE/S WINDS WILL CONTINUE TONIGHT AND
HAVE ADDED THE ALBEMARLE SOUND TO THE SMALL CRAFT ADVISORY THAT
WILL REMAIN IN EFFECT UNTIL 5 AM SUNDAY. WILL INITIALIZE WINDS AT
20 TO 25 KNOTS FOR ALL WATERS...EXCEPT 25 TO 30 KNOTS OVER THE
OREGON INLET TO OCRACOKE LEG WHERE DIAMOND BUOY IS REPORTING 29
KNOTS WITH GUSTS TO 33 KNOTS AND DUCK IS UP TO 32 KNOTS WITH GUSTS
TO 38 KNOTS. THESE WINDS SHOULD SETTLE DOWN AFTER MIDNIGHT AS
WINDS VEER TO MORE SW LATE. PER LATEST WAVEWATCH...SEAS OF 7 TO 10
FEET WILL PREVAIL OVER THE NORTHERN WATERS WITH GENERALLY 5 TO 8
FEET OVER SOUTHERN PORTIONS...WITH A SLIGHT DROP IN THE MORE
WESTERLY FLOW DURING THE DAY ON SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 3 PM SAT...AN OVERALL IMPROVING TREND SEEN IN MARINE
CONDITIONS THROUGH THE LONG TERM. SURFACE/UPPER LOW WILL MOVE OFF
TO THE NORTHEAST SUNDAY NIGHT WITH SURFACE/UPPER RIDGE QUICKLY
BUILDING IN AND LINGERING FOR MOST OF THE WEEK. SMALL CRAFT
CONDITIONS WILL END FROM SOUTH TO NORTH MONDAY AND MONDAY NIGHT.
NORTHWEST FLOW SUNDAY NIGHT INTO MONDAY WILL BECOME WEST TO
SOUTHWEST TUESDAY NIGHT THROUGH THURSDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EDT SUNDAY FOR AMZ130-135.
SMALL CRAFT ADVISORY UNTIL 2 AM EDT TUESDAY FOR AMZ152-154.
SMALL CRAFT ADVISORY UNTIL 5 PM EDT MONDAY FOR AMZ156-158.
SMALL CRAFT ADVISORY UNTIL 8 PM EDT MONDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...HSA
AVIATION...HSA/LEP
MARINE...CTC/HSA
AREA FORECAST DISCUSSION
NWS RALEIGH NC
245 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A POTENT STORM SYSTEM WILL TRACK EAST ACROSS THE REGION THROUGH
SUNDAY AFTERNOON. HIGH PRESSURE WILL BUILD INTO THE CAROLINAS
FROM THE WEST LATE SUNDAY THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 930 AM SATURDAY...
DUE TO IMPROVED VISIBILITIES...HAVE CANCELLED THE DENSE FOG
ADVISORY IN MOST AREAS EXCEPT FOR THE NORTHERN PIEDMONT /I-85
CORRIDOR FROM CHAPEL HILL TO HENDERSON/ WHERE PATCHY DENSE FOG
WILL PERSIST THROUGH ~10 AM. -VINCENT
FOR TODAY/TONIGHT: LATEST OBSERVATIONAL DATA AND SHORT-TERM MODEL
GUIDANCE GENERALLY SUPPORT OUR EARLIER THINKING... THAT WE`LL SEE A
BORDERLINE STRONG/SEVERE EVENT WITH DAMAGING WIND AS A PRIME THREAT
LATE TODAY. EXTENT/SEVERITY WILL LIKELY BE LIMITED BY MARGINAL
INSTABILITY AND A DELAY IN THE MORE VIGOROUS DYNAMICS UNTIL AFTER
THE PEAK INSTABILITY.
CURRENTLY... WIDESPREAD RAIN PERSISTS OVER MUCH OF CENTRAL/ERN NC...
DRIVEN BY DEEP MOIST UPGLIDE AND LOW LEVEL MASS CONVERGENCE
ASSOCIATED WITH A WEAK WAVE PASSING NORTHEAST THROUGH THE AREA... IN
THE WARM SECTOR AHEAD OF THE DEEPENING UPPER LOW DIGGING TOWARD THE
MID MISS VALLEY. LATEST MODEL RUNS SUGGEST THAT THIS MOIST UPGLIDE
WILL PERSIST FOR SEVERAL MORE HOURS BEFORE THE FOCUS SHIFTS TO OUR
NORTHEAST... BRINGING A RELATIVE LULL IN COVERAGE (MORE PATCHY THAN
THE CURRENT WIDESPREAD COVERAGE) FOR MOST AREAS BY MID MORNING AS
OVERALL ASCENT WEAKENS BRIEFLY. THIS SCENARIO IS SUPPORTED BY THE
MOST RECENT HRRR RUNS. WILL INDICATE PRECIP CHANCES SLIPPING BACK TO
LIKELY WITH A PERIOD OF LOWER QPF FROM SOON AFTER SUNRISE THROUGH
MUCH OF THE MORNING... BUT EXPECT THICK LOW-BASED CLOUDS TO PERSIST
AREAWIDE. THE LATEST SURFACE ANALYSIS SHOWS SLIGHTLY MORE STABLE AIR
OVER THE NW CWA (AND EXTENDING BACK TO THE EASTERN SLOPES OF WRN NC)
WHERE THE RAIN IS EXITING... AND THESE AREAS WILL BE SUSCEPTIBLE TO
DENSE FOG THROUGH DAYBREAK GIVEN THE LIGHT/CALM WINDS... DAMP
GROUND... AND PROXIMITY TO HIGHER TERRAIN TO HELP BLOCK THIS GROWING
STABLE POOL. WILL ISSUE A DENSE FOG ADVISORY THIS MORNING FOR THE
NW CWA... WHERE 1/4 MI VSBYS ARE QUICKLY BECOMING PERVASIVE.
ATTENTION THEN TURNS TO THE MATURE MCS NOW TRACKING THROUGH MS INTO
WRN AL (WITH IMPRESSIVE SATELLITE AND RADAR SIGNATURES). ACCORDING
TO EXTRAPOLATION AND RECENT RAP/HRRR RUNS... THE MCV EMANATING FROM
THIS MCS IS ON PACE TO TRACK NORTHEASTWARD... PASSING THROUGH
CENTRAL/ERN NC BETWEEN 18Z AND 23Z TODAY. A FEW FACTORS ARE APPARENT
WHICH SHOULD ENHANCE INSTABILITY OVER CENTRAL NC THIS AFTERNOON...
INCLUDING SIMPLY THE EXISTENCE OF THE MCV AND ITS SIGNAL ON HIGH-RES
MODEL OUTPUT... AN AREA OF RELATIVE DRYING ALOFT (NOTED AT 700 MB ON
THE NAM/GFS) TO POTENTIALLY ELEVATE INSTABILITY... WARM NEAR-SURFACE
AIR WITH HIGH DEW POINTS (UPPER 50S-LOWER 60S)... AND A ROUGHLY 40
KT SOUTHWESTERLY LOW LEVEL JET EXPECTED TO SWEEP NORTHEAST ACROSS
THE ERN HALF OF NC 18Z-00Z TODAY. MODELS STILL INDICATE FAIRLY
SKINNY MUCAPE UP TO 500-1000 J/KG MAINLY OVER THE SE CWA FROM 18Z-
03Z (PEAKING 21Z-00Z) WITH LONG STRAIGHT HODOGRAPHS... SUGGESTING A
MAINLY WIND THREAT GIVEN SOME DRYING ALOFT. INITIALLY THOUGH -- AND
ESPECIALLY IN THE TRIAD -- THESE HODOGRAPHS ARE CURVED ENOUGH TO
BRING ABOUT A CONCERN FOR AN ISOLATED TORNADO IF WE CAN GET ENOUGH
INSTABILITY DURING THE EARLY AFTERNOON... WITH THE PRIMARY THREAT
ALONG THE EDGE OF THE WEAK STABLE POOL. BUT IF THIS PRECEDING RAIN
PERSISTS LONG ENOUGH INTO THE DAY... IT COULD LIMIT THIS
INSTABILITY. ANOTHER MITIGATING FACTOR IS THE APPARENT SLIGHT
TEMPORAL DISCONNECT BETWEEN THESE FAVORABLE SIGNALS AND THE BEST
DYNAMIC FORCING FOR ASCENT... WHICH IS EXPECTED TO ARRIVE THIS
EVENING/TONIGHT IN THE FORM OF STRONG DPVA AND 150-200 M HEIGHT
FALLS... AS WELL AS A 500 MB JET STREAK OF 60+ KTS WHICH STRENGTHENS
ON THE SOUTH SIDE OF THE LOW AND NOSES INTO CENTRAL/ERN NC 00Z-06Z.
FINALLY... THE LATEST HRRR RUNS SUGGEST THAT THE COLD POOL NOW
TRACKING THROUGH AL MAY TRACK MOSTLY ACROSS GA/SC... AND THAT
CONVECTIVE DEVELOPMENT OVER NC MAY BE SUBDUED. IN SUMMARY... WHILE
THE THREAT OF SEVERE WINDS (AND POSSIBLY AN ISOLATED WEAK TORNADO OR
SMALL HAIL REPORT OR TWO) REMAINS OVER OUR SOUTHEAST... A WIDESPREAD
SEVERE WEATHER EVENT IS NOT ANTICIPATED.
WE MAY SEE ANOTHER NARROW BAND OF MOSTLY SHOWERS THIS EVENING AS THE
ACTUAL COLD FRONT SWEEPS EASTWARD... FOLLOWED BY A SW TO NE END TO
POPS OVERNIGHT. STILL EXPECT A CYCLOGENESIS PATTERN CLOSE TO A
MILLER-B... WITH THE PRIMARY SURFACE LOW DISSIPATING OVER FAR SW VA
AS SECONDARY LOW PRESSURE FORMS ALONG A WEAK TRIPLE POINT OVER THE
SW NC FOOTHILLS AND THEN TRACKS NE OVER WRN AND NORTH CENTRAL NC
INTO SE VA TONIGHT. THE RAPID STRENGTHENING OF THE UPPER LOW AS IT
TRACKS OVERHEAD WILL LEAD TO RAPID DEEPENING OF THE SURFACE LOW AND
THUS AN INCREASE IN WINDS BEHIND THE COLD FRONT LATE TONIGHT.
DESPITE THE LOW LEVEL STABILIZATION... FORECAST SOUNDINGS SUGGEST
PLENTY OF LINGERING MOISTURE IN THE 925-700 MB LAYER FOR LINGERING
MOSTLY CLOUDY SKIES ESPECIALLY IN THE NORTHERN CWA OVERNIGHT.
FOLLOWING HIGH-RES SHORT TERM GUIDANCE... EXPECT HIGHS TODAY FROM
MID 60S NW TO MID 70S SE... NO BETTER THAN A 10-15 DEG F DIURNAL
RANGE. LOWS TONIGHT 41 NW TO 48 SE.
&&
.SHORT TERM /SUNDAY AND SUNDAY NIGHT/...
AS OF 300 PM SATURDAY...
THE UPPER LOW WILL ASSUME A NEGATIVE TILT AS IT PIVOTS SLOWLY
NORTHEASTWARD ACROSS NC AND VIRGINIA DURING THE DAY ON
SUNDAY...MOVING OFF THE DELMARVA COAST SUNDAY EVENING/NIGHT.
SOUNDINGS SHOW STRONG COOLING/MOISTENING ALOFT AS THE COLD CORE LOW
MOVES THROUGH THE AREA...WITH TEMPERATURES STRUGGLING TOO WARM
DURING THE DAY WITH OVERCAST LOW CLOUDS AND RENEWED PRECIP WITHIN A
WRAP AROUND PRECIP BAND. HAVE LOWERED FORECAST HIGHS QUITE A
BIT...ESPECIALLY ACROSS THE NORTH WHERE HIGHER POPS/QPF IS EXPECTED.
HIGHS RANGING FROM NEAR 50 NE TO MID/UPPER 50S ACROSS THE
SOUTH/SOUTHWEST...AND EVEN THAT COULD BE TOO WARM IF SOME OF THE
WETTER SOLUTIONS VERIFY. DEEPENING SURFACE EXITING THE TIDEWATER
COAST SHOULD RESULT IN BREEZY CONDITIONS WITH SUSTAINED NWLY WINDS
15-20KTS...GUSTING TO 30KTS...REMAINING BELOW ADVISORY CRITERIA.
PRECIP WILL TAPER OFF AND MOISTURE WILL CLEAR OUT FROM SW TO NE
DURING THE EVENING AS THE UPPER LOW SHIFTS OFFSHORE. LOWS IN THE
LOWER TO MID 30S NW TO MID/UPPER 30S SE WITH A STEADY 7-10KT BREEZE
PREVENTING WIDESPREAD FROST.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
AS OF 300 PM SATURDAY...
TEMPERATURES WILL QUICKLY MODIFY MONDAY WITH STRONG SYNOPTIC SCALE
SUBSIDENCE AS S/W RIDGING DEVELOPS ACROSS THE SOUTHEAST AND REMAINS
OVER THE AREA THROUGH LATE IN THE WORK WEEK. THIS WILL KEEP THE
PRIMARY STORM TRACK WELL NORTH OF THE AREA...THROUGH THE MIDWEST AND
GREAT LAKES REGION. THIS WILL SUPPORT DRY CONDITIONS THROUGH
THURSDAY. AFTER SEASONABLE HIGHS OF UPPER 60S/LOWER 70S ON MONDAY...
EXPECT ABOVE NORMAL TEMPERATURES OF 75-80 WED/THURS.
NEXT WEATHER SYSTEM COULD IMPACT THE AREA LATE FRIDAY AND INTO
SATURDAY WITH CURRENT MODEL PROJECTION SHOWING A WEAKENING BAND OF
CONVECTION ACROSS THE SOUTHEAST...AS IT BECOMES WELL REMOVED FROM
THE ATTENDANT S/W TROUGH LIFTING NEWD THROUGH THE GREAT LAKES.
IMPACTS/SEVERE THREAT APPEAR MINIMAL AT THIS TIME.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
AS OF 730 AM SATURDAY...
POOR AVIATION CONDITIONS ARE EXPECTED TO PERSIST THROUGH AT LEAST
06Z TONIGHT. SOME IMPROVEMENT FROM IFR TO MVFR IS EXPECTED AT
INT/GSO TOWARD THE END OF THE TAF VALID PERIOD AT 12Z. A DEEP MOIST
FLOW FROM THE SOUTH AND SW... AHEAD OF A STRENGTHENING STORM SYSTEM
NOW MOVING THROUGH MS AND WRN TN... WILL BRING IFR/LIFR CONDITIONS
AND PERIODS OF MOSTLY LIGHT RAIN THROUGH DAYBREAK. WE SHOULD SEE A
BRIEF BREAK OR LULL IN THE WIDESPREAD RAIN THROUGH THE LATE MORNING
THROUGH EARLY AFTERNOON HOURS... MOST LIKELY FROM 14Z TO 19Z... BUT
CIGS ARE LIKELY TO REMAIN IFR WITH MVFR TO IFR VSBYS DURING THIS
TIME... WITH IFR/LIFR CONDITIONS MOST LIKELY AT INT/GSO. THEN
STARTING SOON AFTER 19Z... A LINE OF SHOWERS AND THUNDERSTORMS IS
EXPECTED TO SWEEP EAST-NORTHEAST THROUGH CENTRAL NC THROUGH THE LATE
AFTERNOON/EARLY EVENING HOURS... BRINGING THE POTENTIAL FOR LOCALLY
STRONG WIND GUSTS OVER 30 MPH... AND PERHAPS A FEW SEVERE STORMS.
THESE STORMS ARE EXPECTED TO EXIT THE AREA TO OUR NORTHEAST AFTER
02Z... HOWEVER THE PASSAGE OF A COLD FRONT WITH AN UPPER LEVEL LOW
CLOSE ON ITS HEELS WILL BRING A CONTINUED THREAT OF MVFR-IFR CIGS
THROUGH LATE EVENING AND INTO EARLY OVERNIGHT. WINDS WILL SHIFT TO
BE FROM THE NW WITH THE COLD FRONT PASSAGE... BETWEEN 02Z AND 04Z AT
INT/GSO... BETWEEN 04Z AND 06Z AT RDU.... AND BETWEEN 07Z AND 09Z AT
RWI/FAY.
LOOKING BEYOND 12Z TONIGHT... MVFR CIGS ARE EXPECTED TO DOMINATE
THROUGH 18Z SUN. WINDS WILL BE BRISK AND GUSTY FROM THE NW
THROUGHOUT SUNDAY... BRINGING A CROSSWIND THREAT MAINLY AT GSO/RDU.
BETWEEN 18Z SUN AND 00Z MON... SLOW WEST-TO-EAST CLEARING IS
EXPECTED AS THE UPPER LEVEL LOW MOVES SLOWLY THROUGH THE AREA...
WITH AT TREND TO VFR AT INT/GSO/RDU LIKELY BY 00Z... AND AT RWI/FAY
BETWEEN 00Z AND 06Z EARLY MON MORNING. VFR CONDITIONS ARE LIKELY
FROM LATE SUN NIGHT THROUGH WED AS HIGH PRESSURE BUILDS INTO THE
AREA FROM THE WEST. -GIH
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT/HARTFIELD
SHORT TERM...CBL
LONG TERM...CBL
AVIATION...HARTFIELD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
115 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A WAVE OF LOW PRESSURE WILL FORM OVER KENTUCKY AND TENNESSEE
AND MOVE TO THE DELMARVA REGION BY TONIGHT. THE ASSOCIATED UPPER
LEVEL TROUGH WILL GET DEEPER...SLOWING DOWN THE SYSTEM
SIGNIFICANTLY. MILDER TEMPERATURES BUT CONTINUED UNSETTLED
CONDITIONS ARE EXPECTED FOR NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
WINTER WEATHER ADVISORY RECENTLY ISSUED FOR WARREN...MCKEAN AND
POTTER COUNTIES 8 PM THIS EVENING TO NOON SUNDAY.
WORDED FCST AND GRIDDED FIELDS TRACKING PRETTY MUCH AS EXPECTED.
THE NW EDGE OF A LARGE SHIELD OF STEADY LIGHT TO MODERATE RAIN
CONTINUES TO DRIFT NORTHWARD ACROSS THE LOWER SUSQ VALLEY...WHILE
AREAS OF LIGHT RAIN/SHOWERS BLOSSOM/ADVECT NWD INTO SCENT PENN AND
THE LAURELS.
THIS WILL BE A LONG-DURATION PRECIP EVENT FOR MOST OF THE
CWA...LASTING BETWEEN 36-48 HOURS.
THE BULK OF THE PRECIP WILL FALL AS RAIN OF VARYING
INTENSITY...BUT LATER SECTIONS OF THIS DISCUSSION WILL COVER THE
WINTRY ASPECTS OF THIS SLOW-MOVING WEATHER SYSTEM /EXPECTED TO
IMPACT THE HIGHER TERRAIN OF THE NORTH AND WEST AS WE HEAD INTO
TONIGHT AND SUNDAY/.
FOR THE NEAR TERM...POCKETS OF EARLIER SUNSHINE NEAR AND JUST TO
THE NORTH OF I-80 HAVE VANISHED WITH THICK...LAYERED CLOUDS AND
AREAS OF RAIN SPREADING IN FROM THE SOUTH.
12Z 13KM RAP AND 09Z SREF INDICATE THAT MUCH OF CENTRAL AND NRN
PENN WILL STAY DRY UNDER MAINLY A MID CLOUD DECK THROUGH 18-20Z
BEFORE THE RAIN ENCROACHES FROM THE SW AND SE.
PRACTICALLY ALL LOCATIONS IN THE CWA SHOULD SEE RAIN BY 23Z
TODAY...WITH THE HIGHEST TOTALS /BETWEEN 0.25-0.50 OF AN INCH/
OCCURRING ACROSS THE LAURELS...AND FAR SERN COUNTIES.
16Z TEMPS RANGE FROM NEAR 40F ACROSS THE NW MTNS...TO THE MID AND
UPPER 40S ELSEWHERE...AND WILL HOLD FAIRLY STEADY FOR THE REST OF
THE AFTERNOON /BUT SHOULD BEGIN TO SLOWLY SLIDE THROUGH THE 30S
ACROSS THE NW MTNS AFTER 20Z/.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM SUNDAY/...
THE STORM DEEPENS RAPIDLY AS IT MOVES OVER THE MID-ATLANTIC
STATES. THE UPPER LEVEL TROUGH CUTS OFF AND THE WIND PULLS IN LOTS
OF MOISTURE...MAINLY FROM THE SOUTH/GOMEX. BUT THE SYSTEM ALMOST
STALLS OVERHEAD. THIS WILL CREATE HEAVY RAIN FOR MUCH OF THE
AREA...BUT MAINLY OVER THE EAST WHERE FLOOD WATCH IS ALREADY IN
EFFECT. SEE HYDRO SECTION FOR MORE ON WATER ISSUES.
THE OTHER TROUBLE WITH THE PRECIP IS THAT THE TEMPS SLOWLY DROP
IN THE EVENING /AND ESPECIALLY OVERNIGHT/ ACROSS THE NRN AND WRN
MTNS. THUS...THE NORTHWESTERN COUNTIES AND HIGHER ELEVATION IN
THE CENTRAL MTNS WILL LIKELY SEE THE RAIN TURN TO A FEW-0SEVERAL
HOUR PERIOD OF FZRA...A SHORTER PERIOD OF SLEET...THEN EVENTUALLY
ACCUMULATING WET SNOW LATE TONIGHT AND SUNDAY MORNING WITH 2-4
INCHES LIKELY.
THE INITIAL FREEZING RAIN /FROM WARREN COUNTY EAST TO POTTER
COUNTY/...COULD ACCUMULATE UP TO ONE-QUARTER OF AN INCH IN SOME
AREAS AS NEAR SFC TEMPS COOL BELOW FREEZING...PRIOR TO THE ZERO C
ISOTHERM ARRIVING IN THE 925-850 MB LAYER/.
TEMPS DO NOT SEEM TO EVER GET AOB FZG IN THE RIDGE AND VALLEY
REGION SO...WILL JUST GO WITH A GRADUAL CHANGE/MIX HERE. QPF IN
THE NORTHWEST AFTER THE CHANGE TO SNOW IS A VERY DIFFICULT PART OF
THE FCST. IN GENERAL...THE EXPECTATION IS THAT THE HEAVY PRECIP
WILL BE TO THE EAST BY LATE TONIGHT...AND THAT SHOULD LIMIT THE
UPPER END OF THE SNOW ACCUMS TO 3 OR 4 INCHES /WHICH AGREES WELL
WITH A BLEND OF THE 09Z SREF AND 12Z NAM 24-HOUR SNOW ACCUMS/.
BIG FOCUS AND COORDINATION OVER THE NEXT FEW HOURS WILL CONCERN
THE POTENTIAL FOR SEVERAL /OR MORE/ INCHES OF HEAVY WET SNOW
ACROSS THE LAURELS. IT APPEARS AT THIS TIME WE/RE LEANING TWD WINTER
WEATHER ADVISORY TYPE AMTS FOR LATE TONIGHT THROUGH EARLY SUNDAY
AFTERNOON.
THE DAYTIME /AND LATE MARCH SUN ANGLE/ ON SUNDAY SHOULD HELP
TEMPS RISE SLIGHTLY...BUT THE UPPER LOW/TROUGH AXIS WILL BE RIGHT
OVERHEAD. CLOUDS WILL BE THICK EVEN WHERE THE PRECIP GETS
LIGHTER/SPOTTY. IT WONT FEEL TOO NICE WITH TEMPS IN THE 30S NW AND
L-M40S ELSEWHERE. THE WIND WILL GET CRANKING WITH THE DEEPENING
SFC LOW VERY CLOSE BY. HAVE NUDGED POPS UP FOR SUNDAY AND EARLY
SUNDAY NIGHT TO ALLOW FOR THE FURTHER SLOW-DOWN IN THE CONSENSUS
OF MDL DATA.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
LATEST MODEL SOLUTIONS CONTINUE TO SLOW DOWN THE PROGRESSION OF THIS
WEEKEND/S STORM...RESULTING IN LINGERING SHOWERS OVER THE EAST FOR
SUNDAY. TEMPERATURES WILL BE COLD ENOUGH SATURDAY NIGHT AND INTO
THE MORNING HOURS ON SUNDAY FOR THE PRECIPITATION TO FALL AS A
LIGHT DUSTING OF SNOW OVER THE NORTH AND HIGHER ELEVATIONS.
AT THIS POINT...MONDAY WILL BE ONE OF THE BEST DAYS OF THE
EXTENDED FORECAST WITH HIGH PRESSURE...FAIR SKIES...AND SEASONABLE
TEMPERATURES. A LOW PRESSURE SYSTEM WILL SLIDE NORTH OF THE STATE
TUESDAY NIGHT...BRINGING MORE CLOUDS TO THE REGION. LIGHT SHOWERS
CANNOT BE RULED OUT ACROSS THE NORTH AS A WEAK COLD FRONT MOVES
THROUGH. SUNSHINE WILL MAKE A BRIEF RETURN FOR WEDNESDAY BEFORE
ANOTHER STORM SYSTEM ORGANIZES OVER THE MIDWEST...AND MOVE EAST
FOR THE END OF THE WEEK. THERE IS STILL A GOOD BIT OF MODEL
SPREAD...BUT RAIN SHOWERS ARE POSSIBLE AS EARLY AS THURSDAY AS THE
ASSOCIATED WARM FRONT NOSES INTO PENNSYLVANIA. THE COLD FRONT WILL
MOVE THROUGH THE AREA DURING THE FIRST PART OF THE WEEKEND
BRINGING MORE RAIN.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
MVFR TO VFR STRATO CU AND AREAS OF ALTO CU ACROSS THE NRN HALF OF
PENN WILL GRADUALLY LOWER LATER TODAY AND TONIGHT...TO MAINLY IFR
WITH POCKETS OF LIFR AS RAIN OVERSPREADS THE AREA FROM THE
SOUTH...AND CHANGES FROM FZRA TO SLEET...THEN SNOW INVOF KBFD AND
POINTS WEST AFTER 00Z SUNDAY.
IFR ACROSS THE SOUTH EARLY THIS AFTERNOON WILL STAY INTACT THROUGH
SUNDAY MORNING...WITH PERIODS OF LIFR LIKELY IN FOG /AND
EVENTUALLY MIXED PRECIP CHANGING TO SNOW ACROSS THE LAURELS/.
DEVELOPING LOW PRESSURE OVR THE SE STATES WILL LIFT UP THE
APPALACHIAN MTNS LATER TODAY...HELPING TO SPREAD RAIN AND LOWERING
CIGS NORTHWARD ACROSS PENNSYLVANIA.
UNSTABLE AIR WORKING INTO SE PA WILL BRING A LOW PROBABILITY FOR A
A FEW TSRA ARND KMDT AND KLNS THIS EVENING.
OUTLOOK...
SUN...WINDY. RAIN/LOW CIGS POSS...ESP EAST.
MON-WED...NO SIG WX EXPECTED.
&&
.HYDROLOGY...
FLOOD WATCH CONTINUES FOR ABOUT EASTERN THIRD OF CWA FOR LATER
TODAY THROUGH SUNDAY EVENING. THE UPPER LOW IS EXPECTED TO CLOSE
OFF AND POSSIBLY STALL ALONG MID ATLC COAST. THIS WILL PRODUCE MDT
TO HEAVY RAINS OVER MUCH OF THE AREA DURING THIS PD. THE HIGHER
AMOUNTS STILL LOOK TO BE IN THE EAST...ESPECIALLY IF A WIDELY
PROGGED DEFORMATION-TYPE AREA OF PRECIP FORMS ON SUNDAY. LOCALIZED
STORM TOTAL AMOUNTS OF 1-2 INCHES SEEM REASONABLE. BUT IF IT
CONTINUES TO LOOK LIKE THE PRECIP WILL RE-INVIGORATE ON
SUNDAY...THE WATCH MAY NEED TO BE EXTENDED. GEFS/SREF GUIDANCE
SHOWS PWAT ANOMALIES GREATER THAN 2 STANDARD DEVIATES OVER EASTERN
PA SAT AFTN AND EVENING PROVIDING SUFFICIENT MOISTURE FOR HIGH
RAINFALL RATES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH SUNDAY EVENING FOR PAZ028-036-037-041-042-
046-049>053-056>059-063>066.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO NOON EDT
SUNDAY FOR PAZ004>006.
&&
$$
SYNOPSIS...LAMBERT/DANGELO
NEAR TERM...LAMBERT
SHORT TERM...DANGELO
LONG TERM...COLBERT
AVIATION...LAMBERT
HYDROLOGY...LAMBERT
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
104 PM CDT SAT MAR 29 2014
.UPDATE...FOR 18Z TAFS.
&&
.AVIATION...
SFC LOW/COLD FRONT NOW WELL EAST OF THE MID-STATE BUT PLENTY
OF LL MOISTURE/SHOWERS REMAIN BEHIND. HEAVIER RAIN OVER FOR
CKV/BNA BUT STILL MAY AFFECT CSV THROUGH 21Z OR SO. MOISTURE
EXTENDS WELL UPSTREAM AND THAT IS LIKELY TO KEEP AT LEAST MVFR
CIGS ACROSS THE AREA WELL INTO THE EVENING AND POSSIBLY INTO THE
OVERNIGHT CSV. WINDS GUSTING 20-25KTS EXPECTED TO KEEP VSBYS
FAVORABLE BUT FOG MAY REDEVELOP OVERNIGHT AS WIND WEAKENS.
&&
.PREV DISCUSSION... /ISSUED 1112 AM CDT SAT MAR 29 2014/
UPDATE...
SFC LOW CURRENTLY CENTERED ACROSS EAST TN/NORTH GA...WITH
TRAILING UPPER TROUGH NEAR THE MS RIVER. WIDESPREAD RAIN
CONTINUES ACROSS THE MID-STATE BUT THE BACK EDGE IS NOT FAR
WEST OF THE TN RIVER. NORTHWEST WINDS BEHIND PULLING DOWN
MUCH COOLER AIR WITH TEMPS UPSTREAM LARGELY MID 40S. DO
EXPECT RAIN TO PULL EAST THIS AFTERNOON BUT DO NOT EXPECT
MUCH RECOVERY IN TEMPS...ESPECIALLY WITH A LOW CLOUD DECK
LIKELY MOST OF THE DAY. WILL LOWER TEMPS AND REALIGN AFTERNOON
WX SLIGHTLY.
PREV DISCUSSION... /ISSUED 600 AM CDT SAT MAR 29 2014/
UPDATE...
12Z TAF DISCUSSION.
AVIATION...
-SHRA WILL CONTINUE SPREADING ACROSS AREA AIRPORTS THIS MORNING
BEFORE EXITING CKV/BNA BY EARLY AFTERNOON AND CSV BY EVENING.
LITTLE LIGHTNING HAS BEEN NOTED AND WILL LEAVE OUT MENTION OF TS.
MVFR/IFR CIGS TO BECOME VFR LATE IN THE TAF PERIOD AT
CKV/BNA...BUT THESE CIGS MAY LINGER AT CSV. LIGHT
SOUTHEAST/NORTHEAST WINDS WILL BECOME NORTHWEST AND GUSTY BY
AFTERNOON AS COLD FRONT MOVES ACROSS.
SHAMBURGER
PREV DISCUSSION... /ISSUED 335 AM CDT SAT MAR 29 2014/
DISCUSSION...
SFC LOW WL MOVE FROM EASTERN MS ACRS E TN TDY. INVERTED TROF OVER
THE MID STATE WILL ALSO SHIFT EAST AND ALLOW COLDER AIR TO FILTER
IN. THE MAIN CHALLENGES IN THE NEAR TERM INVOLVE PCPN CVRG AND HOW
MUCH TEMPS WL RECOVER AS PCPN PULLS OUT LATER. FOR NOW LEANED PCPN
FCST TWRD THE LATEST HRRR WHICH HAS HAD A PRETTY GOOD HANDLE ON
THINGS THUS FAR. XPCT TO SEE RAIN INCRS IN CVRG QUICKLY OVER THE
NEXT FEW HOURS AND GRADUALLY EVOLVE INTO A BIT OF A COMMA HEAD
BEFORE PULLING OUT LATER THIS AFTN. RAIN WILL LIKELY NOT REACH THE
PLATEAU UNTIL MID MORNING AND WILL BE ENDING ALONG THE TN RIVER BY
MIDDAY. AS FAR AS TEMPS GO...HIGHS ARND NASHVILLE AND POINTS EAST
WILL LIKELY BE RIGHT ARND 8 AM JUST AHEAD OF THE BNDRY WITH A
PRETTY SHARP DROP THRU THE MORNING. WILL SEE SOME TEMPERATURE RECOVERY
AGAIN IN THE AFTN AS RAIN CVRG DECREASES.
SOME RAIN MAY LINGER IN THE FAR EAST ERLY THIS EVE OTHW XPCT A
QUICK CLEARING AS SYS PULLS AWAY. MAV TEMPERATURES LOOK RSNBL
GIVEN THE CLEARING SKIES AND A PRETTY COOL START. WX THEN LOOKS
NICE AND SPRINGLIKE INTO MID-WEEK AS RIDGING DOMINATES. STILL WL
HV TO WATCH WEAK FRONT ON TUE FOR SOME CLDS AND A LITTLE LIGHT
PCPN BUT DOESN`T LOOK LIKE MUCH RIGHT NOW. HPC TEMPS WERE FOLLOWED
PRETTY CLOSE.
THE FAR EXTENDED STILL LOOKS ACTIVE BUT AS IS TYPICAL THE ALL
IMPORTANT DETAILS ARE MURKY. GENERAL PATTERN SUGGESTS WARM AND
HUMID CONDITIONS WITH ROUNDS OF SHOWERS AND STORMS AS SFC LOWS
MOVE TO OUR WEST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1112 AM CDT SAT MAR 29 2014
.UPDATE...
SFC LOW CURRENTLY CENTERED ACROSS EAST TN/NORTH GA...WITH
TRAILING UPPER TROUGH NEAR THE MS RIVER. WIDESPREAD RAIN
CONTINUES ACROSS THE MID-STATE BUT THE BACK EDGE IS NOT FAR
WEST OF THE TN RIVER. NORTHWEST WINDS BEHIND PULLING DOWN
MUCH COOLER AIR WITH TEMPS UPSTREAM LARGELY MID 40S. DO
EXPECT RAIN TO PULL EAST THIS AFTERNOON BUT DO NOT EXPECT
MUCH RECOVERY IN TEMPS...ESPECIALLY WITH A LOW CLOUD DECK
LIKELY MOST OF THE DAY. WILL LOWER TEMPS AND REALIGN AFTERNOON
WX SLIGHTLY.
&&
.PREV DISCUSSION... /ISSUED 600 AM CDT SAT MAR 29 2014/
UPDATE...
12Z TAF DISCUSSION.
AVIATION...
-SHRA WILL CONTINUE SPREADING ACROSS AREA AIRPORTS THIS MORNING
BEFORE EXITING CKV/BNA BY EARLY AFTERNOON AND CSV BY EVENING.
LITTLE LIGHTNING HAS BEEN NOTED AND WILL LEAVE OUT MENTION OF TS.
MVFR/IFR CIGS TO BECOME VFR LATE IN THE TAF PERIOD AT
CKV/BNA...BUT THESE CIGS MAY LINGER AT CSV. LIGHT
SOUTHEAST/NORTHEAST WINDS WILL BECOME NORTHWEST AND GUSTY BY
AFTERNOON AS COLD FRONT MOVES ACROSS.
SHAMBURGER
PREV DISCUSSION... /ISSUED 335 AM CDT SAT MAR 29 2014/
DISCUSSION...
SFC LOW WL MOVE FROM EASTERN MS ACRS E TN TDY. INVERTED TROF OVER
THE MID STATE WILL ALSO SHIFT EAST AND ALLOW COLDER AIR TO FILTER
IN. THE MAIN CHALLENGES IN THE NEAR TERM INVOLVE PCPN CVRG AND HOW
MUCH TEMPS WL RECOVER AS PCPN PULLS OUT LATER. FOR NOW LEANED PCPN
FCST TWRD THE LATEST HRRR WHICH HAS HAD A PRETTY GOOD HANDLE ON
THINGS THUS FAR. XPCT TO SEE RAIN INCRS IN CVRG QUICKLY OVER THE
NEXT FEW HOURS AND GRADUALLY EVOLVE INTO A BIT OF A COMMA HEAD
BEFORE PULLING OUT LATER THIS AFTN. RAIN WILL LIKELY NOT REACH THE
PLATEAU UNTIL MID MORNING AND WILL BE ENDING ALONG THE TN RIVER BY
MIDDAY. AS FAR AS TEMPS GO...HIGHS ARND NASHVILLE AND POINTS EAST
WILL LIKELY BE RIGHT ARND 8 AM JUST AHEAD OF THE BNDRY WITH A
PRETTY SHARP DROP THRU THE MORNING. WILL SEE SOME TEMPERATURE RECOVERY
AGAIN IN THE AFTN AS RAIN CVRG DECREASES.
SOME RAIN MAY LINGER IN THE FAR EAST ERLY THIS EVE OTHW XPCT A
QUICK CLEARING AS SYS PULLS AWAY. MAV TEMPERATURES LOOK RSNBL
GIVEN THE CLEARING SKIES AND A PRETTY COOL START. WX THEN LOOKS
NICE AND SPRINGLIKE INTO MID-WEEK AS RIDGING DOMINATES. STILL WL
HV TO WATCH WEAK FRONT ON TUE FOR SOME CLDS AND A LITTLE LIGHT
PCPN BUT DOESN`T LOOK LIKE MUCH RIGHT NOW. HPC TEMPS WERE FOLLOWED
PRETTY CLOSE.
THE FAR EXTENDED STILL LOOKS ACTIVE BUT AS IS TYPICAL THE ALL
IMPORTANT DETAILS ARE MURKY. GENERAL PATTERN SUGGESTS WARM AND
HUMID CONDITIONS WITH ROUNDS OF SHOWERS AND STORMS AS SFC LOWS
MOVE TO OUR WEST.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
07
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
425 PM EDT SAT MAR 29 2014
.SYNOPSIS...
A LOW PRESSURE PASSING WEST OF THE REGION THIS AFTERNOON WILL DRAG
A COLD FRONT ACROSS THE MID ATLANTIC DURING THE EVENING. THE
SUPPORTING UPPER LEVEL LOW WILL PASS ACROSS THE CENTRAL
APPALACHIANS OVERNIGHT...RESULTING IN UPSLOPE SNOW SHOWERS AND
VERY STRONG WINDS LATE TONIGHT THROUGH SUNDAY EVENING. HIGH
PRESSURE WILL RETURN TO THE AREA SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
AS OF 400 PM EDT SATURDAY...
EXPECT A VERY ACTIVE AND CHALLENGING WEATHER FORECAST FOR THE
NEXT 24 HOURS.
CURRENTLY KEEPING AN EYE ON A SURFACE LOW PRESSURE SYSTEM PASSING
NORTHEAST ACROSS EXTREME WESTERN VIRGINIA THIS AFTERNOON. DEEP
ATLANTIC MOISTURE FLOWING INTO OUR REGION HAS MAINTAINED SHOWERY
AND FOGGY CONDITIONS ACROSS MOST OF THE AREA THROUGH THE DAY...AND
EXPECT THESE CONDITIONS TO PERSIST THROUGH THE EVENING UNTIL THE
COLD FRONT ARRIVES.
THE COLD FRONT IS EXPECTED TO ENTER OUR WESTERN COUNTIES BY AROUND
6 PM...TRIGGERING A BROKEN LINE OF SHOWERS AS IT PASSES. THE FRONT
WILL THEN SHIFT EAST...EXITING OUR AREA TO THE EAST RIGHT AROUND
MIDNIGHT. THE FOGGY SHOWERY CONDITIONS HAVE DONE A GOOD JOB OF
LIMITING INSTABILITY THIS AFTERNOON...SUCH THAT THE THREAT OF ANY
STRONG THUNDERSTORM DEVELOPMENT APPEARS STRICTLY LIMITED THIS
AFTERNOON. BEST CHANCES FOR THUNDERSTORM ACTIVITY REMAIN ACROSS
PORTIONS OF THE NORTH CAROLINA PIEDMONT AND SOUTHSIDE VIRGINIA
THIS EVENING...POSSIBLY RESULTING IN PERIODS OF HEAVY RAIN AND
ISOLATED GUSTY WINDS.
AS THE FRONT EXITS THE AREA...WE TURN OUR ATTENTION TO THE PASSAGE
OF THE SUPPORTING UPPER LEVEL LOW PRESSURE SYSTEM THAT WILL PASS
ACROSS THE SOUTHERN HALF OF OUR AREA AFTER MIDNIGHT. THE FIRST
CONCERN WILL BE THE UPSLOPE SNOW SHOWERS THAT WILL DEVELOP ACROSS
THE MOUNTAINS. MODELS CONTINUE TO INDICATE A STRONG DEFORMATION
ZONE DEVELOPING ACROSS CENTRAL WEST VIRGINIA OVERNIGHT WHICH WILL
ENHANCE THE SNOW SHOWERS ACROSS OUR WESTERN RIDGES. BELIEVE WE
WILL SEE A FEW HOURS OF HEAVY SNOW BETWEEN MIDNIGHT AND SUNRISE
SUCH THAT WE CAN EXPECT 4 TO 6 INCHES ABOVE 2500 FEET IN
GREENBRIER...SUMMERS AND MERCER COUNTIES IN SOUTHEAST WEST
VIRGINIA...AND 1 TO 4 INCHES ELSEWHERE ACROSS MOST OF OUR
REMAINING MOUNTAIN COUNTIES UP TO THE BLUE RIDGE. SNOW SHOWERS
WILL DIMINISH BY LATE SUNDAY MORNING AS THE UPPER LOW SHIFTS AWAY
FROM OUR AREA.
THE OTHER CONCERN WILL BE STRONG WINDS BEGINNING TONIGHT. A QUICK
SURGE IN WINDS RIGHT BEHIND THE FRONT WILL CAUSE SPEEDS TO
RAPIDLY INCREASE FROM SOUTHWEST TO NORTHEAST...AND REACH
ADVISORY/WARNING CRITERIA OVER PARTS OF THE MOUNTAINS DURING THE
EARLY MORNING HOURS AS THE PROGGED 85H JET TOPS 50 KTS AND MUCH
COLDER AIR RUSHES IN. FORECAST INVERSION REMAINS RELATIVELY HIGH
BUT GIVEN LATE NIGHT TIMING WOULD FAVOR GOING ON THE STRONG SIDE
OF GUIDANCE DESPITE SOME OFFSET IN MIXING VIA CLOUDS INTO EARLY
SUNDAY MORNING. MIXING ALONG/EAST OF THE BLUE RIDGE BECOMES
DEEPEST SUNDAY MORNING INTO SUNDAY AFTERNOON WHEN A VERY
IMPRESSIVE JET COUPLET ALOFT SLIDES ACROSS AND SUBSIDENCE MAXES
OVERHEAD. GRADIENT LOOKS QUITE TIGHT AND IF CLOUDS CLEAR QUICKER
THEN SPEEDS MAY BE STRONGER...ESPECIALLY EAST OF THE BLUE RIDGE
SUNDAY AFTERNOON AS PERHAPS GRAVITY WAVES SLIDE OFF THE MOUNTAINS.
SINCE THE CORE OF THE STRONGER WINDS LIKELY TO IMPACT AREAS FROM
THE ROANOKE VALLEY INTO THE NORTHWEST NORTH CAROLINA MOUNTAINS
WHERE DAMAGING WINDS MORE LIKELY...HAVE UPGRADED PARTS OF THE
GOING ADVISORY TO A HIGH WIND WARNING AND INCLUDED THE VA
HIGHLANDS FOR MAINLY HIGHER ELEVATION SPEEDS. INCLUDED AN ADVISORY
ELSW OVER THE EARLIER WATCH AREA AS WELL AS ADDING HENRY...MERCER
AND MONROE COUNTIES FOR NOW GIVEN POTENTIAL TREE DAMAGE PER WET
SOILS.
CONDITIONS WILL IMPROVE DURING LATE AFTERNOON AND EVENING AS THE
UPPER SYSTEM PUSHES AWAY FROM THE AREA...WITH WIND SPEEDS
DIMINISHING AND SNOW SHOWERS COMING TO AN END.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
AS OF 215 PM EDT SATURDAY...
DEEP LOW PRESSURE WILL BE SLOWLY EXITING OFFSHORE SUNDAY NIGHT
ALLOWING DRIER HIGH PRESSURE TO BUILD IN FROM THE WEST. HOWEVER WITH
THIS LOW BASICALLY CUTOFF...THE GRADIENT BETWEEN THE TWO WILL BE
SLOW TO WEAKEN WITH STRONG WINDS LIKELY TO CONTINUE INTO SUNDAY
EVENING PROVIDING FOR ONLY A GRADUAL DIMINISHING TREND BY EARLY
MONDAY. THINK RESIDUAL DEEPER MOISTURE SHOULD BE EAST OF THE AREA BY
SUNDAY NIGHT SO GOING WITH CLEARING SKIES WITHOUT POP AND CLOSER TO
THE SLIGHTLY WARMER MET MOS TEMPS PER MIXING/WARMING ALOFT.
SHORTWAVE RIDGING BUILDS IN FOR MONDAY WITH ANOTHER DRAMATIC
TURNAROUND IN TEMPS UNDER SUNSHINE AS 85H VALUES GO FROM BELOW 0C
SUNDAY EVENING TO AS WARM AS +11C BY LATE MONDAY. THIS ALONG WITH
VERY DRY AIR IN PLACE SHOULD SEND HIGHS ZOOMING BACK INTO THE 60S
WEST AND AROUND 70 EAST UNDER DIMINISHING WINDS.
RIDGING REMAINS IN PLACE MONDAY EVENING INTO TUESDAY WITH LARGE
VALLEY/ELEVATION TEMP RANGE MONDAY NIGHT...THEN EVEN MILDER TUESDAY
WITH MORE OF A WEST TO SW TRAJECTORY IN PLACE. CLOUDS MAY INCREASE
FROM THE WEST LATER TUESDAY AHEAD OF THE NEXT FRONT BUT WITH ANY
DEEPER MOISTURE REMAINING WEST OF THE REGION. THIS SHOULD PUSH HIGHS
WELL INTO THE 70S EAST AND CLOSE TO 70 WEST OUTSIDE OF THE HIGHER
ELEVATIONS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 1145 AM EDT SATURDAY...
BROAD UPPER RIDGING TO REMAIN IN PLACE UNTIL NEAR THE END OF THE
PERIOD WITH SURFACE HIGH PRESSURE OFF THE SE COAST AND MEAN
TROUGHING ACROSS THE CENTRAL AND SW STATES. WILL SEE A WEAK SURFACE
FRONT PUSH SOUTH OF THE REGION WEDNESDAY AS A WAVE PASSES WELL TO
THE NORTH AND HEIGHTS DIP A BIT. HOWEVER THIS BOUNDARY INITIALLY DRY
WITH ONLY WEAK HIGH PRESSURE TO THE NW WHICH SHOULD DO LITTLE TO
DETER VERY WARM TEMPS FOR MIDWEEK. FRONT LOOKS TO LIFT BACK NORTH
THROUGH THE REGION THURSDAY AS STRONGER LOW PRESSURE PIVOTS TOWARD
THE UPPER MIDWEST. BAND OF DEEPER MOISTURE/LIFT MAY TEND TO SPILL
DOWN THE BAROCLINIC ZONE FROM THE WEST SO BUMPED UP POPS STARTING
THURSDAY MORNING...CONTINUING INTO THURSDAY EVENING WITH MOISTURE
AROUND AND WEAK IMPULSES SLIDING BY. STRONGER COLD FRONT WITH THE
WAVE TO THE WEST WILL APPROACH FRIDAY AND SHOULD PASS ACROSS THE
AREA FRIDAY NIGHT INTO EARLY SATURDAY PER THE FASTER EC. EXPECT PRE-
FRONTAL BAND OF SHRA TO AFFECT MUCH OF THE REGION BY FRIDAY
AFTERNOON WITH SOME ISOLATED TSRA POSSIBLE SOUTH AND SW SO RUNNING
WITH CHANCE TO LOW LIKELY POPS INTO FRIDAY EVENING. BOUNDARY LOOKS
TO GET FAR ENOUGH SE TO ALLOW DRYING ON SATURDAY WITH ONLY SOME
EARLY CLOUDS/-SHRA MAINLY NW AND CLEARING ELSW PENDING LATER RUNS.
GOOD SOUTH TO SW FLOW SHOULD FINALLY BRING TEMPS UP TO SPRING LEVELS
AND ALLOW THEM TO STAY THERE WITH HIGHS MOSTLY 70S EXCEPT COOLING TO
60S SATURDAY BEHIND THE FRONT. LOWS WELL ABOVE FREEZING AND PERHAPS
STAYING ABOVE 50 OUT EAST DURING MIDWEEK.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
AS OF 130 PM EDT SATURDAY...
MOST TAF SITES ARE IN THE SOUP AHEAD OF LOW APPROACHING FROM THE
SOUTHWEST. AS LOW TRACKS THROUGH THE AREA IT WILL SWING A STRONG
COLD FRONT THROUGH...WHICH WILL SWEEP OUT THE FOG BUT BE FOLLOWED
BY UPSLOPE SNOW SHOWERS OVERNIGHT...AND VERY STRONG WINDS LATE
TONIGHT INTO SUNDAY.
ONE BIG CHALLENGE IS WHAT HAPPENS TO CIGS/VSBYS AHEAD OF THE
APPROACHING FRONT. WILL BASE THE EARLY CIGS/VSBYS ON TRENDS SHOWN
IN HRRR AND LOCAL WRF MODEL RUN. WITH THIS IN MIND...EXPECT
CIGS/VSBYS TO IMPROVE AHEAD OF CFROPA. BELIEVE THE HEAVIEST PCPN
CAN BE EXPECTED JUST AHEAD AND ALONG THE FRONT AS IT PASSES. WILL
TIME CFROPA AT KBLF/KLWB 23Z...KBKB 00Z...KROA 01Z...AND KLYH/KDAN
02Z. ANY EMBEDDED CONVECTION ALONG THE FRONT MAY CREATE SOME
SIGNIFICANT LOCAL GUSTS BUT WILL NOT INDICATE THIS IN THE TAFS
SINCE IT WILL BE NEARLY IMPOSSIBLE TO DO SO WITH ANY DEGREE OF
ACCURACY.
COLD AIR WILL BEGIN TO SURGE IN BEHIND THE FRONT AND EXPECT A
TYPICAL NW FLOW SCENARIO WITH KBLF/KLWB SEEING BETTER CHANCES FOR
-SHSN...KBCB ON THE EDGE...AND NOTHING FOR THE PIEDMONT DOWNSLOPE
AREAS WORTH MENTIONING IN THE TAFS. THE BUILDING WINDS MAY
TRANSLATE -SHSN A BIT FURTHER WEST BUT THE OVERALL FLAVOR WILL
REMAIN THE SAME. EXPECT HIGHEST WIND GUSTS TO OCCUR AFTER DAYBREAK
SUNDAY AS INSOLATION COMBINES WITH CAA TO MAXIMIZE MIXING.
LOOKING DOWN THE ROAD...DRY WEATHER AND VFR CONDITIONS ARE
EXPECTED MONDAY THROUGH TUESDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...HIGH WIND WARNING FROM 10 PM THIS EVENING TO 10 PM EDT SUNDAY
FOR VAZ009-012>020-022-032-033.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT
SUNDAY FOR VAZ007-009>012-015-018>020.
WIND ADVISORY FROM 10 PM THIS EVENING TO 10 PM EDT SUNDAY FOR
VAZ007-010-011-023-024-034-035-043.
NC...HIGH WIND WARNING FROM 10 PM THIS EVENING TO 10 PM EDT SUNDAY
FOR NCZ001-002-018.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT
SUNDAY FOR NCZ001-018.
WIND ADVISORY FROM 10 PM THIS EVENING TO 10 PM EDT SUNDAY FOR
NCZ003-019.
WV...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EDT
SUNDAY FOR WVZ042>045.
WIND ADVISORY FROM 10 PM THIS EVENING TO 10 PM EDT SUNDAY FOR
WVZ042-044.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 4 PM EDT SUNDAY
FOR WVZ042-043-045.
&&
$$
SYNOPSIS...NF
NEAR TERM...JH/NF
SHORT TERM...JH
LONG TERM...JH
AVIATION...MBS
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
553 PM CDT SAT MAR 29 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 248 PM CDT SAT MAR 29 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM QUEBEC TO THE WESTERN GREAT LAKES TO THE
STATE OF TEXAS. EARLIER RIBBON OF STRATO-CU OVER PARTS OF CENTRAL
AND NORTHEAST WISCONSIN DISSIPATED AROUND MIDDAY LEAVING MOSTLY
SUNNY CONDITIONS ACROSS THE NORTHERN HALF OF THE STATE. LOOKING
UPSTREAM...THE JET IS PUSHING MID AND HIGH CLOUDS TO THE EAST ACROSS
THE PLAINS. BUT OTHERWISE QUIET CONDITIONS EXIST UNTIL NORTHWEST
MONTANA IN THE VICINITY OF SHORTWAVE ENERGY. WITH THAT SHORTWAVE
EXPECTED TO PASS NORTH OF THE REGION...THE MAIN FORECAST CONCERNS
INCLUDE CLOUDS AND TEMPS IN THE SHORT TERM.
TONIGHT...SURFACE HIGH PRESSURE WILL SHIFT FROM THE WESTERN TO THE
CENTRAL GREAT LAKES WHILE THE MID-LEVEL RIDGE AXIS WORKS ACROSS THE
STATE. SHORTWAVE ENERGY MOVING ACROSS SOUTHERN CANADA WILL SEND MID
AND HIGH CLOUDS ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. BUT
SOME OF THESE CLOUDS WILL LIKELY GRAZE NORTHERN WISCONSIN.
OTHERWISE...MOSTLY CLEAR TO CLEAR CONDITIONS WILL PREVAIL.
DEVELOPING SOUTHEAST WINDS WILL LIKELY TEMP KEEPS FROM PLUMMETING
OVER THE DEEP SNOW PACK OF N-C WISCONSIN. TEMPS MAINLY IN THE
20...EXCEPT FOR A FEW TEENS OVER FAR NE WISCONSIN.
SUNDAY...RETURN FLOW WILL BE RAMPING UP THROUGH THE DAY AS LOW
PRESSURE EMERGES INTO THE CENTRAL PLAINS. AT THE SAME TIME...A COLD
FRONT WILL BE SAGGING SOUTHEAST ACROSS MINNESOTA AND INTO FAR NW
WISCONSIN BY LATE IN THE AFTERNOON. SOUTH TO SOUTHEAST WINDS WILL
BE ADVECTING WARMER AIR IN THE LOW LEVELS WHICH WILL LEAD TO A
WARMER DAY ACROSS THE REGION. THE EXCEPTION WILL BE ALONG THE LAKE
AND BAY SHORE WHERE ONSHORE FLOW WILL PUSH IN A COLD MARINE LAYER.
SO WILL GO WITH HIGHS IN THE UPPER 50S IN THE WARM SPOTS...TO THE
UPPER 30S ALONG LAKE MICHIGAN. SHOULD SEE MORE IN THE WAY OF MID
AND HIGH CLOUDS WHICH WILL PROVIDE FILTERED SUNSHINE AT TIMES...BUT
DO NOT THINK THEY WILL HAVE MUCH IMPACT ON TEMPS.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 248 PM CDT SAT MAR 29 2014
THE MODELS ARE NOW IN FAIRLY GOOD AGREEMENT THAT THE SYSTEM MOVING
OUT OF THE CENTRAL PLAINS WILL TRACK TO THE WEST OF OUR FORECAST
AREA...RESULTING IN MOSTLY RAIN AND A CHANCE OF THUNDERSTORMS. THE
RAIN SHOULD ARRIVE FROM WEST TO EAST MONDAY AFTERNOON AND CONTINUE
MONDAY NIGHT. COLDER AIR AND SNOW SHOWERS ARE LIKELY TUESDAY. THE
MAIN CONCERN FROM THE RAIN AND WARMER TEMPERATURES IS MELTING SNOW
AND RIVER ICE WITH THE POSSIBILITY OF LOCAL FLOODING. HIGH
PRESSURE BUILDS IN TUESDAY NIGHT AND WEDNESDAY BEFORE ANOTHER
SYSTEM APPROACHES FROM THE SOUTHERN PLAINS. THE GFS IS MUCH FASTER
AND FLATTER WITH THE SURFACE SYSTEM AND WE WOULD BE IN THE
NORTHERN FRINGE OF IT AND RECEIVE SOME SNOW WHILE THE ECMWF IS
SLOWER AND STRONGER AND WE WOULD HAVE PRECIPITATION TYPE ISSUES
DUE TO A MORE NORTHERLY TRACK. THEN A LITTLE COLDER AND DRY
WEATHER EXPECTED FRIDAY AND SATURDAY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 520 PM CDT SAT MAR 29 2014
CLEAR SKIES HAVE PREVAILED OVER NORTHEAST WISCONSIN THIS EVENING.
THE QUIET VFR CONDITIONS WILL PREVAIL THROUGH THE TONIGHT. MID-
LEVEL CLOUDS WILL BE ON THE INCREASE SUNDAY MORNING AND THEN STICK
AROUND FOR THE REST OF THE DAY...HOWEVER VFR CONDITIONS ARE
EXPECTED. AFTER LIGHT WINDS TONIGHT...EXPECT SOUTHEAST WINDS TO
INCREASE SUNDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 248 PM CDT SAT MAR 29 2014
WARMER TEMPERATURES...MELTING SNOW AND RAIN WILL PRODUCE AN
INCREASE IN THE CHANCES OF LOCAL FLOODING EARLY NEXT WEEK. THE SNOW
IS VERY DEEP IN THE NORTH AND SHOULD BE ABLE TO ABSORB THE
RAINFALL WITHOUT FULLY MELTING BUT PLACES WITH JUST A FEW INCHES
LEFT MAY HAVE MOST OF IT MELT AND RUN OFF THE FROZEN GROUND INTO
RIVERS AND STREAMS. THERE IS ALSO A CHANCE OF ICE JAMS AS RIVER
ICE BREAKS UP. WE HAVE A HYDROLOGICAL OUTLOOK IN EFFECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......WOLF
HYDROLOGY......RDM
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 248 PM CDT SAT MAR 29 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW HIGH
PRESSURE STRETCHING FROM QUEBEC TO THE WESTERN GREAT LAKES TO THE
STATE OF TEXAS. EARLIER RIBBON OF STRATO-CU OVER PARTS OF CENTRAL
AND NORTHEAST WISCONSIN DISSIPATED AROUND MIDDAY LEAVING MOSTLY
SUNNY CONDITIONS ACROSS THE NORTHERN HALF OF THE STATE. LOOKING
UPSTREAM...THE JET IS PUSHING MID AND HIGH CLOUDS TO THE EAST ACROSS
THE PLAINS. BUT OTHERWISE QUIET CONDITIONS EXIST UNTIL NORTHWEST
MONTANA IN THE VICINITY OF SHORTWAVE ENERGY. WITH THAT SHORTWAVE
EXPECTED TO PASS NORTH OF THE REGION...THE MAIN FORECAST CONCERNS
INCLUDE CLOUDS AND TEMPS IN THE SHORT TERM.
TONIGHT...SURFACE HIGH PRESSURE WILL SHIFT FROM THE WESTERN TO THE
CENTRAL GREAT LAKES WHILE THE MID-LEVEL RIDGE AXIS WORKS ACROSS THE
STATE. SHORTWAVE ENERGY MOVING ACROSS SOUTHERN CANADA WILL SEND MID
AND HIGH CLOUDS ACROSS NORTHERN MINNESOTA AND LAKE SUPERIOR. BUT
SOME OF THESE CLOUDS WILL LIKELY GRAZE NORTHERN WISCONSIN.
OTHERWISE...MOSTLY CLEAR TO CLEAR CONDITIONS WILL PREVAIL.
DEVELOPING SOUTHEAST WINDS WILL LIKELY TEMP KEEPS FROM PLUMMETING
OVER THE DEEP SNOW PACK OF N-C WISCONSIN. TEMPS MAINLY IN THE
20...EXCEPT FOR A FEW TEENS OVER FAR NE WISCONSIN.
SUNDAY...RETURN FLOW WILL BE RAMPING UP THROUGH THE DAY AS LOW
PRESSURE EMERGES INTO THE CENTRAL PLAINS. AT THE SAME TIME...A COLD
FRONT WILL BE SAGGING SOUTHEAST ACROSS MINNESOTA AND INTO FAR NW
WISCONSIN BY LATE IN THE AFTERNOON. SOUTH TO SOUTHEAST WINDS WILL
BE ADVECTING WARMER AIR IN THE LOW LEVELS WHICH WILL LEAD TO A
WARMER DAY ACROSS THE REGION. THE EXCEPTION WILL BE ALONG THE LAKE
AND BAY SHORE WHERE ONSHORE FLOW WILL PUSH IN A COLD MARINE LAYER.
SO WILL GO WITH HIGHS IN THE UPPER 50S IN THE WARM SPOTS...TO THE
UPPER 30S ALONG LAKE MICHIGAN. SHOULD SEE MORE IN THE WAY OF MID
AND HIGH CLOUDS WHICH WILL PROVIDE FILTERED SUNSHINE AT TIMES...BUT
DO NOT THINK THEY WILL HAVE MUCH IMPACT ON TEMPS.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 248 PM CDT SAT MAR 29 2014
THE MODELS ARE NOW IN FAIRLY GOOD AGREEMENT THAT THE SYSTEM MOVING
OUT OF THE CENTRAL PLAINS WILL TRACK TO THE WEST OF OUR FORECAST
AREA...RESULTING IN MOSTLY RAIN AND A CHANCE OF THUNDERSTORMS. THE
RAIN SHOULD ARRIVE FROM WEST TO EAST MONDAY AFTERNOON AND CONTINUE
MONDAY NIGHT. COLDER AIR AND SNOW SHOWERS ARE LIKELY TUESDAY. THE
MAIN CONCERN FROM THE RAIN AND WARMER TEMPERATURES IS MELTING SNOW
AND RIVER ICE WITH THE POSSIBILITY OF LOCAL FLOODING. HIGH
PRESSURE BUILDS IN TUESDAY NIGHT AND WEDNESDAY BEFORE ANOTHER
SYSTEM APPROACHES FROM THE SOUTHERN PLAINS. THE GFS IS MUCH FASTER
AND FLATTER WITH THE SURFACE SYSTEM AND WE WOULD BE IN THE
NORTHERN FRINGE OF IT AND RECEIVE SOME SNOW WHILE THE ECMWF IS
SLOWER AND STRONGER AND WE WOULD HAVE PRECIPITATION TYPE ISSUES
DUE TO A MORE NORTHERLY TRACK. THEN A LITTLE COLDER AND DRY
WEATHER EXPECTED FRIDAY AND SATURDAY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1229 PM CDT SAT MAR 29 2014
SCT TO BKN MVFR CIGS ACROSS NORTH-CENTRAL AND NORTHEAST
WISCONSIN HAVE TURNED VFR LATE THIS MORNING AND HAVE NEARLY
DISSIPATED. THEREFORE...EXPECT FEW CLOUD COVERAGE AT TAF ISSUANCE
WHICH SHOULD BECOME SKC LATER IN THE AFTERNOON. QUIET CONDITIONS
WILL PREVAIL TONIGHT WITH LIGHT WINDS. THEN MID-LEVEL CLOUDS WILL
BE ON THE INCREASE SUNDAY MORNING WHILE SOUTHEAST WINDS WILL
INCREASE AT THE SAME TIME.
&&
.HYDROLOGY...
ISSUED AT 248 PM CDT SAT MAR 29 2014
WARMER TEMPERATURES...MELTING SNOW AND RAIN WILL PRODUCE AN
INCREASE IN THE CHANCES OF LOCAL FLOODING EARLY NEXT WEEK. THE SNOW
IS VERY DEEP IN THE NORTH AND SHOULD BE ABLE TO ABSORB THE
RAINFALL WITHOUT FULLY MELTING BUT PLACES WITH JUST A FEW INCHES
LEFT MAY HAVE MOST OF IT MELT AND RUN OFF THE FROZEN GROUND INTO
RIVERS AND STREAMS. THERE IS ALSO A CHANCE OF ICE JAMS AS RIVER
ICE BREAKS UP. WE HAVE A HYDROLOGICAL OUTLOOK IN EFFECT.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....MPC
LONG TERM......RDM
AVIATION.......MPC
HYDROLOGY......RDM
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1242 PM CDT SAT MAR 29 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CDT SAT MAR 29 2014
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A VERY DEEP TROUGH OFF THE PACIFIC NORTHWEST...RIDGING
PUSHING EASTWARD ACROSS THE ROCKIES...AND TROUGHING FROM MINNESOTA
SOUTH INTO ARKANSAS. THE NORTHERN PORTION OF THIS TROUGH HAS BEEN
UNEVENTFUL FOR THE FORECAST AREA...BRINGING ONLY SOME MID/HIGH
CLOUDS. DRY AIR SITUATED BETWEEN 900-700MB ON THE 00Z GRB...MPX AND
DVN SOUNDINGS KEPT ANY POTENTIAL PRECIPITATION FROM THESE CLOUDS
FROM REACHING THE GROUND. HOWEVER...AT AND BELOW 900MB...
OBSERVATIONS ARE SHOWING SOME LOW STRATUS DEVELOPING ACROSS
SOUTHERN WI. THIS STRATUS IS A RESULT OF EASTERLY FLOW OF MOISTURE
FROM LAKE MICHIGAN COMBINING WITH NOCTURNAL COOLING AND AN INVERTED
SURFACE TROUGH IN THE AREA. TO THE NORTHWEST...CLEARING ASSOCIATED
WITH SURFACE HIGH PRESSURE WAS PRESENT ACROSS MUCH OF MINNESOTA.
AIRMASS OVER THE UPPER MIDWEST STILL RELATIVELY COOL WITH 00Z RAOBS
SHOWING 925MB TEMPS OF -3 TO -5C FROM THE FORECAST AREA TO BIS.
HOWEVER...LBF AND UNR ON THE BACK SIDE OF THE SURFACE HIGH WERE MUCH
WARMER AT +11 AND +15C RESPECTIVELY.
A PROGRESSIVE UPPER FLOW PATTERN IS PROGGED THROUGH THE SHORT TERM
PERIOD AS A VIGOROUS SHORTWAVE AT THE BOTTOM OF THE EAST PACIFIC
TROUGH...NEAR 35 NORTH / 140 WEST...MOVES INTO CALIFORNIA. FOR
COMPARISON...THE FORECAST AREA GOES FROM UNDER A SHORTWAVE TROUGH
AXIS AT 12Z SATURDAY TO A RIDGE AXIS AT 12Z SUNDAY. 3 MAIN
IMPACTS FROM THIS SWITCH:
1. SUBSIDENCE AND DRYING ASSOCIATED WITH BUILDING UPPER RIDGING WILL
HELP CLEAR OUT ANY LOW CLOUDS BY 18Z...LEADING TO A SUNNY AFTERNOON
WITH JUST SOME SCATTERED CIRRUS TONIGHT.
2. AFTER MOSTLY A LIGHT WIND FLOW TODAY AS SURFACE RIDGE MOVES
THROUGH...SOUTHERLY WINDS INCREASE GREATLY TONIGHT...ESPECIALLY FROM
925-850MB. BY 12Z SUNDAY...THEY ARE RUNNING BETWEEN 40-50 KT.
3. 925-850MB TEMPS FOLLOW THE INCREASE IN WINDS. FOR EXAMPLE...
925MB TEMPS AFTER STARTING OFF BETWEEN -2 TO -5C AT 12Z THIS MORNING
CLIMB TO 0 TO +3C AT 00Z SUNDAY...THEN TO 2 TO +5C AT 12Z SUNDAY.
SUNSHINE SHOULD EASILY BOOST HIGHS INTO THE 40S TODAY AT MOST
LOCATIONS...WITH A FEW VALLEY AREAS APPROACHING 50. TEMPERATURES
SHOULD BOTTOM OUT THIS EVENING BEFORE THE LOW LEVEL JET INCREASES
AND CAUSES THEM TO STABILIZE. READINGS SHOULD RISE LATE TONIGHT AS
THE WARMER AIR FLOWS IN.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 328 AM CDT SAT MAR 29 2014
MANY WEATHER CONCERNS TO HIGHLIGHT DURING THE LONG TERM PERIOD AS
THE FORECAST AREA LOOKS TO RESIDE MUCH OF THE TIME IN SOUTHWEST FLOW
ALOFT.
1. ABOVE NORMAL TEMPERATURES SUNDAY THROUGH MONDAY. THE VIGOROUS
SHORTWAVE COMING INTO CALIFORNIA TONIGHT REMAINS ON TRACK TO LIFT
INTO EASTERN SOUTH DAKOTA OR SOUTHWEST MN BY 00Z TUESDAY...PUSHING
WARM...DOWNSLOPED AIR OFF THE ROCKIES INTO THE FORECAST AREA AHEAD
OF IT. 925MB TEMPS ARE PROGGED TO CLIMB TO 9-13C BY 00Z
MONDAY...COOLEST OVER TAYLOR/CLARK COUNTIES. THESE READINGS COMBINED
WITH SUN THROUGH SCT-BKN CIRRUS AND BREEZY SOUTHERLY WINDS SHOULD
PUSH TEMPERATURES INTO THE 60S ALONG/SOUTHWEST OF I-94...WITH 50S TO
THE NORTH. A SOUTHERLY BREEZE PERSISTS INTO SUNDAY NIGHT AND
MONDAY. THIS WIND SHOULD ONLY ALLOW TEMPERATURES TO FALL INTO THE
40S SUNDAY NIGHT...WITH MAYBE SOME 30S IN THE TYPICAL COLD SPOTS.
THEN ON MONDAY...WITH MODEL CONSENSUS KEEPING THE FORECAST AREA IN
THE WARM SECTOR HIGHLIGHTED BY 925MB TEMPS OF 9-13C...SHOULD SEE
ANOTHER DAY OF HIGHS MOSTLY IN THE MID 50S TO MID 60S. THIS OCCURS
DESPITE SOME WARM ADVECTION PRECIPITATION MOVING THROUGH.
2. PRECIPITATION AND THUNDERSTORM POTENTIAL MONDAY INTO MONDAY
NIGHT. THE SIGNAL STILL EXISTS FOR A WARM CONVEYOR BELT OF
SHOWERS TO MOVE ACROSS THE FORECAST AREA...ESPECIALLY DURING THE
LATE MORNING AND AFTERNOON HOURS...AS ISENTROPIC LIFT ON 300K
SURFACES AND ABOVE INCREASES. THE BEST MOISTURE EXISTS NORTH OF I-
90...THUS HIGHEST CHANCES OF 50-70 ARE SITUATED THERE. THE POTENTIAL
STILL EXISTS FOR A BAND OF SHOWERS AND SOME EMBEDDED THUNDERSTORMS
TO FORM ALONG THE COLD FRONT CROSSING LATE IN THE AFTERNOON AND
EVENING. HOWEVER...A COUPLE OF CONCERNS FOR THIS BAND INCLUDE MODELS
MAY BE OVERDOING THE MOISTURE RETURN AND NOT MIXING DEWPOINTS OUT
ENOUGH...AND THE TIME OF DAY IS BEING PUSHED TO OUTSIDE OF PEAK
HEATING. SHOULD STORMS FIRE...THERE REMAINS AMPLE SHEAR TO ALLOW FOR
SEVERE WEATHER. LASTLY...CONFIDENCE HAS INCREASED THAT THE
DEFORMATION BAND ON THE NORTHWEST SIDE OF THE ASSOCIATED SURFACE LOW
WILL TRACK NORTHWEST OF THE FORECAST AREA ON MONDAY...AND CLIP THE
NORTHWEST HALF OF THE FORECAST AREA MONDAY NIGHT BEFORE LIFTING OFF
TO THE NORTHEAST. COLDER AIR RUSHING IN SHOULD ALLOW FOR A
CHANGEOVER TO SNOW...WITH A BRIEF PERIOD OF SLEET POSSIBLE DURING
THIS CHANGEOVER AS COLD AIR UNDERCUTS WARMER AIR ALOFT. LITTLE SNOW
ACCUMULATION IS EXPECTED...THOUGH. THERE IS ALSO POTENTIAL TO LOSE
ICE IN THE CLOUDS DUE TO A DRY SLOT...BUT THE LOSS OF ICE OCCURS
EITHER WHERE TEMPERATURES ARE ABOVE FREEZING TO RESULT IN RAIN OR
WHERE NO PRECIPITATION WILL OCCUR.
3. WINDS MONDAY AFTERNOON AND NIGHT. ECMWF/GFS PROG 925MB WINDS OF
30-40 KT SOUTH OF I-90 DURING THE AFTERNOON. IF MORE SUN OCCURS THAN
EXPECTED...THESE COULD EASILY MIX DOWN TO THE SURFACE AND SEE
BOTH SUSTAINED WINDS AND GUSTS APPROACH ADVISORY. INCREASED WINDS
AND GUSTS AS A RESULT. ALSO...AS THE LOW PASSES TO OUR
NORTHEAST...A TIGHT PRESSURE GRADIENT WITH 925MB WINDS OF 30-40 KT
FROM THE SOUTHWEST TO WEST USHERS IN COLD AIR. WITH SOME ISALLOBARIC
AID...COULD SEE GUSTS HERE TOO APPROACH ADVISORY FOR A BRIEF TIME.
4. WINTRY MIX POTENTIAL LATE TUESDAY NIGHT THROUGH FRIDAY. MODELS
ARE AT ODDS ON HOW TO HANDLE THE EJECTION OF TROUGHING OUT OF THE
SOUTHWESTERN U.S. ON TUESDAY TOWARDS THE REGION LATER IN THE WEEK.
THERE WILL NO DOUBT BE A COLDER DOME OF HIGH PRESSURE INFLUENCING
THE AREA...LIKELY SITUATED FROM NORTHERN MN INTO UPPER MI. IN
ADDITION...AS THE TROUGH EJECTS...ISENTROPIC LIFT OF WARMER...GULF
OF MEXICO MOISTURE WILL SPREAD PRECIPITATION NORTH TOWARDS THE
FORECAST AREA. THIS SETS UP CONCERN FOR THE WINTRY MIX. FOR NOW HAVE
FOLLOWED A MODEL CONSENSUS WITH PRECIPITATION CHANCES...WHICH SEEMS
MOST LIKELY TO OCCUR WEDNESDAY SOUTH OF I-90. ALSO KEPT TYPES AS
RAIN/SNOW BASED ON HOURLY TEMPERATURES...BUT THERE IS DEFINITELY
POTENTIAL FOR SLEET AND FREEZING RAIN/DRIZZLE AT TIMES. 29.00Z ECMWF
EVEN PRODUCES AT LEAST ADVISORY WORTHY SNOWFALL OVER THE NORTHWEST
HALF OF THE AREA THURSDAY AND THURSDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1240 PM CDT SAT MAR 29 2014
VFR CONDITONS EXPECTED BUT LOW-LEVEL WINDS WILL BE ON THE INCREASE
OVERNIGHT. WITH A STRONG INVERSION IN PLACE OVER THE TAF
SITES...WINDS WILL INCREASE IN THE LOWEST 2KFT RAPIDLY. HAVE
INCLUDED LLWS FOR KRST FOR A PERIOD SUNDAY MORNING.
&&
.HYDROLOGY...
ISSUED AT 328 AM CDT SAT MAR 29 2014
MAIN FOCUS FOR RIVER ISSUES FROM THE RECENT RAIN IS ON THE KICKAPOO
RIVER. SOME LOCATIONS ALONG IT ARE EITHER IN OR EXPECTED TO REACH
FLOOD STAGE AS RUNOFF CONTINUES TO WORK ITS WAY DOWNSTREAM.
FROM SUNDAY INTO MONDAY NIGHT...THE RAPID WARM UP WILL CAUSE THE
SNOW PACK NORTH OF INTERSTATE 94 TO MELT RAPIDLY. IN
ADDITION WITH FROZEN GROUND...ANY RAINFALL ON MONDAY AND
MONDAY NIGHT WILL QUICKLY RUNOFF INTO AREA RIVERS AND STREAMS. THIS
WILL RESULT IN RISES ALONG THE BLACK...BUFFALO...AND TREMPEALEAU
RIVERS IN WESTERN WISCONSIN. SOME FLOODING IS ALSO A POSSIBILITY.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BAUMGARDT
HYDROLOGY...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1131 AM MDT SAT MAR 29 2014
.UPDATE...
ISSUED AT 901 AM MDT SAT MAR 29 2014
WILL HAVE TO KEEP A CLOSE EYE ON WIND SPEEDS IN THE ARLINGTON AREA
TODAY. WINDS HAVE GUSTED AS HIGH AS 57 MPH AT THE ARLINGTON WY DOT
SITE WITH OTHER SITES GUSTING 50 TO 55 MPH. MODELS DO SHOWING
WINDS ALOFT INCREASING SLIGHTLY THIS AFTERNOON BUT NOT AS STRONG
OF SUBSIDENCE. AT THIS TIME WILL HOLD OFF ON ANY HEADLINES AS
WINDS SHOULD BE MARGINAL FOR A HIGH WIND WARNING AND RELATIVELY
LOCALIZED.
UPDATED THE SKY GRIDS AS THE STANDING WAVE CLOUDS IS IN PLACE
ALONG AND EAST OF THE LARAMIE RANGE. MODELS INDICATE THE WAVE
COULD WILL THIN OUT THIS AFTERNOON. SHOULD NOT SEE A BIG IMPACT ON
TEMPERATURES TODAY BUT IT WILL BE A SLOWER RISE IN TEMPERATURES
AND COULD END UP A FEW DEGREES BELOW THE CURRENT FORECAST WHERE
THE WAVE CLOUD HANGS ON THE LONGEST. OTHERWISE FORECAST IN GOOD
SHAPE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
MAIN WEATHER STORIES THROUGH THIS EVENING WILL BE THE WARM
TEMPERATURES AND ASSOCIATED FIRE WEATHER CONCERNS AND THE WINDY
CONDITIONS ALONG AND WEST OF THE LARAMIE RANGE. HIGHS THIS AFTN ARE
STILL EXPECTED TO CLIMB INTO THE 60S AND LOWER 70S ACROSS THE
PLAINS. MAIN CHANGE TO THE FCST GRIDS FOR THIS AFTN WAS TO DECREASE
DEW POINTS...ESPECIALLY STRETCHING FROM LARAMIE COUNTY INTO THE
SOUTHERN PANHANDLE. DEEP SOUTHWESTERLY FLOW IN THE LOW-TO-MID LEVELS
WILL COMBINE WITH EXCELLENT SOLAR INSULATION TO PRODUCE DEEP LLVL
MIXING THIS AFTN AND IT IS THESE CONDITIONS THAT MOS OFTEN GROSSLY
UNDERESTIMATES AFTN DEW POINTS. WENT WITH A BLEND OF THE DRIER MAV
AND RUC GUIDANCE AND THIS RESULTS IN MIN RH VALUES IN THE 10-15
PERCENT RANGE OVER THE PANHANDLE. EXCELLENT MIXING WILL TAP INTO
25-30 KT AT THE TOP OF THE MIXED LAYER. THUS...DECIDED TO ISSUE A
RFW FOR THE ENTIRE PANHANDLE.
THE NEXT ITEM OF CONCERN IS WINDS TO THE WEST OF THE LARAMIE RANGE.
THE GFS SHOWS 700MB WINDS OF 40-45 KT FROM 18-00Z AND THE 700MB
CAG-CPR GRADIENT IS AROUND 45 METERS. CONTEMPLATED PUTTING THE
ARLINGTON AREA IN A HIGH WIND WARNING FOR THE AFTN...HOWEVER WOULD
LIKE TO SEE THE LLVL GRADIENT AND WINDS ALOFT A BIT STRONGER. WILL
LIKELY SEE GUSTS AROUND 45 KT IN THE ARLINGTON AREA WITH THE
FAVORABLE GAP WINDS. OUTSIDE OF ARLINGTON...COULD SEE GUSTS TO 40
KT DURING PEAK MIXING. THE LLVL GRADIENT COMES DOWN BY THIS
EVENING AND FLOW ALOFT BECOMES MORE SOUTHWESTERLY...SO WILL SEE
WINDS DECREASE.
ANOTHER WARM DAY ON SUNDAY AHEAD OF A SHORTWAVE. KEPT A SLIGHT
CHANCE OF AFTN TSTMS IN THE FCST AS BOTH THE GFS AND NAM INDICATE
LIFTED INDICES OF 0C TO -1C. MODELS CONTINUE TO INDICATE THAT THE
UPPER LEVEL SYSTEM WILL MOVE DIRECTLY OVERHEAD ON SUNDAY NIGHT WITH
A FROPA AFTER 06Z MON. BEST UPPER LEVEL DIVERGENCE AND LARGE SCALE
LIFT IS LARGELY OFF TO THE NORTHEAST OF THE CWA...HOWEVER MAY HAVE
TO WATCH THE NORTHEAST ZONES FOR ADVISORY AMOUNTS. THIS AREA WILL
BE CLOSEST TO THE WESTERN EDGE OF A DEVELOPING TROWAL/FRONTOGENESIS
FEATURE OVER SOUTH DAKOTA. JUST SOMETHING TO WATCH IN FUTURE MODEL
RUNS.
.LONG TERM...(EARLY TUESDAY MORNING THROUGH FRIDAY)
ISSUED AT 445 AM MDT SAT MAR 29 2014
MAIN FORECAST CONCERN NEXT WEEK WILL BE A SLOW MOVING UPPER LEVEL
LOW MOVING ACROSS THE GREAT BASIN REGION AND INTO THE ROCKY
MOUNTAINS BY WEDNESDAY. ALTHOUGH MODELS ARE IN POOR AGREEMENT WITH
THIS SYSTEM AND HAVE BEEN OVER THE LAST 48 HOURS...THERE IS STILL
CONCERN OVER A POTENTIAL SIGNIFICANT STORM OVER PORTIONS OF THE
HIGH PLAINS.
FOR TUESDAY...ALL MODELS NOW SHOW THE COLD FRONT FROM SUNDAYS
SYSTEM ALONG THE CONTINENTAL DIVIDE...RETREATING EASTWARD AS A
WARM FRONT. WARM AIR ADVECTION ALOFT AND COOL UPSLOPE FLOW WILL
COMBINE TO PRODUCE OVERRUNNING PRECIPITATION IN THE FORM OF SNOW
ACROSS THE FORECAST AREA. INCREASED POP BETWEEN 30 TO 50 PERCENT
ACROSS MOST OF THE FORECAST AREA WITH THE EXCEPTION OF EXTREME
EASTERN ZONES ACROSS THE SOUTHERN NEBRASKA PANHANDLE. 1 TO 2
INCHES OF SNOW LOOKS POSSIBLE WITH THIS INITIAL OVERRUNNING EVENT
TUESDAY...ESPECIALLY NORTH OF I80. AS THE WARM FRONT LIFTS
NORTHEAST DURING THE DAY...THE SNOW WILL QUICKLY MELT AND/OR
CHANGE TO RAIN AS TEMPERATURES INCREASE INTO THE 50S.
ATTENTION THEN SHIFTS WESTWARD TUESDAY NIGHT AS THE MAIN UPPER
LEVEL LOW MOVES ACROSS THE GREAT BASIN. MODELS ARE STRUGGLING WITH
THE PLACEMENT...MOVEMENT...AND POTENTIAL EVOLUTION OF A STRONG
WINTER STORM. ALL MODELS INDICATE A BRIEF BREAK EARLY WEDNESDAY
BEFORE THE UPPER LEVEL LOW MOVES INTO THE ROCKY MOUNTAIN REGION
AND ATTEMPTS TO BECOME BETTER ORGANIZED. THE ECMWF SHOWS A RATHER
DISORGANIZED STORM SYSTEM...WITH THE MAIN LOW EJECTING NORTHEAST
AND THEN DRIFTING EASTWARD INTO THE DAKOTAS...WHILE THE SOUTHERN
ENERGY PUSHES INTO THE GREAT PLAINS AND THEN INITIATES STRONG
CYCLOGENESIS IN KANSAS/MISSOURI LATE WEDNESDAY NIGHT. THE ECMWF
INDICATES SPLIT FLOW ACROSS SOUTHEAST WYOMING WITH LIGHT SNOW
ACCUMULATIONS NEAR I80 DUE TO THE SOUTHERN WAVE...AND LIGHT SNOW
ACROSS CENTRAL WYOMING DUE TO THE MAIN LOW WITH LITTLE IN BETWEEN.
THE GEM IS THE MOST AGGRESSIVE...SHOWING A COLORADO LOW SLOWLY
EJECTING NORTHEAST FROM THE FOUR CORNERS REGION. THIS SCENARIO
RESULTS IN WIDESPREAD MODERATE TO HEAVY SNOWFALL ACROSS THE
FORECAST AREA BEGINNING WEDNESDAY EVENING AND LASTING THROUGH
THURSDAY. THE 00Z GFS WAS CONSIDERABLY FURTHER SOUTH...WITH THE
I80 CORRIDOR GETTING CLIPPED BY LIGHT SNOWFALL. HOWEVER...THE 06Z
GFS IS FURTHER NORTH CLOSER TO THE GEM. MOST OF THE ENSEMBLE
FORECASTS WERE IN BETWEEN THE GEM AND GFS LAST NIGHT...SO KEPT POP
BETWEEN 25 TO 40 PERCENT OVER THE LOWER ELEVATIONS WITH POP NEAR
70 PERCENT IN THE MOUNTAINS THROUGH THURSDAY EVENING. WILL
CONTINUE TO CLOSELY MONITOR THIS SYSTEM THROUGH THIS WEEKEND AND
EARLY NEXT WEEK FOR CHANGES...BUT A SIGNIFICANT STORM SYSTEM
APPEARS POSSIBLE NEXT WEEK. LOWERED TEMPERATURES BELOW NORMAL
WEDNESDAY THROUGH FRIDAY. A WEAK RIDGE OF HIGH PRESSURE WILL BUILD
ACROSS THE AREA ON FRIDAY...WITH DRIER CONDITIONS EXPECTED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1130 AM MDT SAT MAR 29 2014
CONSIDERABLE MAINLY HIGH LEVEL CLOUDINESS WILL PRODUCE VFR CEILINGS
THROUGH TONIGHT. GUSTY SOUTHWESTERLY SURFACE WINDS WILL PREVAIL THIS
AFTERNOON AND EVENING...WITH THE STRONGER GUSTS /30-40 KT/ EXPECTED
OVER SOUTHEAST AND SOUTH CENTRAL WYOMING.
&&
.FIRE WEATHER...
ISSUED AT 414 AM MDT SAT MAR 29 2014
A WARM AND DRY AIRMASS WILL BE IN PLACE OVER THE REGION THROUGH
THE WEEKEND. HIGHS WILL BE 10-15 DEGREES ABOVE NORMAL. MINIMUM
HUMIDITY VALUES WILL FALL INTO THE 10-15 PERCENT RANGE OVER THE
NEBRASKA PANHANDLE THIS AFTERNOON AND WILL COMBINE WITH GUSTY
SOUTHWEST WINDS TO PRODUCE CRITICAL FIRE WEATHER CONDITIONS. A RED
FLAG WARNING IS IN EFFECT THIS AFTERNOON FOR THE PANHANDLE SINCE
FUELS ARE CONDUCIVE TO FIRE GROWTH IN THAT REGION. WHILE HUMIDITY
VALUES WILL BE SIMILAR ON SUNDAY AFTERNOON...WIND SPEEDS SHOULD BE
LESS SO ONLY AN ELEVATED FIRE WEATHER THREAT IS EXPECTED. COOLER
TEMPERATURES WILL OCCUR ON MONDAY BEHIND A COLD FRONT THAT WILL
PASS OVER THE REGION ON SUNDAY NIGHT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WARNING UNTIL 10 PM MDT THIS EVENING FOR WYZ110.
NE...RED FLAG WARNING UNTIL 7 PM MDT THIS EVENING FOR NEZ311>313.
&&
$$
UPDATE...SML
SHORT TERM...FINCH
LONG TERM...TJT
AVIATION...JAMSKI
FIRE WEATHER...FINCH