Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 03/27/14
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
933 AM PDT Tue Mar 25 2014
.Synopsis...
Wet and cooler weather will arrive today and continue through the
weekend. Significant mountain snow and gusty winds are likely with
possible thunderstorms in the Valley.
&&
.Discussion...
Initial rain band tracking southeast through the northern Sac
valley this morning and will reach the central and southern valley
around noon. This band will break apart somewhat and become more
showery as it transitions east during the afternoon. A few
thunderstorms will be possible this afternoon with the best
instability over the southern sac and nrn San Joaquin valley
between 3-7pm. Small hail will be the main threat with storms.
Current snow levels are around 6500 feet and will fall to 5500
feet by sunset. Short term forecast is on track and no morning
update will be needed.
.Previous Discussion...
Major pattern change begins for interior NorCal today as the
persistent ridge along the west coast gives way to a trough over
the eastern Pacific extending southward from a deep upper low over
the NE Pacific off the coast of BC. A series of weather systems
emanating from this low are forecast to affect the region for at
least the next week or so.
The first in the series of weather systems is presently nearing
the northern CA coast. Radar shows the frontal band just off the
NW coast of CA early this morning, and it will move eastward
across the region today. Precip is expected to begin in the
Redding area this morning, in the Sacramento region this afternoon
and spread east into the northern Sierra by late today or this
evening.
This first system will only bring modest precip totals for the
area. It may also bring a chance of thunderstorms across the
valley later today if the frontal band moves through quick enough
allowing for some clearing late in the day. The latest HRRR times
the back edge of the frontal band through the valley by mid-
afternoon, so this is something to watch this afternoon. Models
continue to show the best instability and surface convergence
across the southern half of the Sacramento Valley southward into
the northern SJ Valley. Snow levels will start initially high
with this system, but rapidly drop below 6000 ft by evening.
Another wave of precip and colder air arrives on Wednesday and
continues into Thursday. With westerly to southwesterly flow
aloft, favorable orographics are expected over the Sierra but may
limit precipitation along the downslope parts of the Sacramento
Valley. Through these two events, potentially up to an inch of
rain will be possible over parts of the Valley. Snow levels will
drop down to around 4000 ft with 4 to 8 inches possible above that
level. Over a foot of snow is expected above 5500 ft with 2 feet
along the northern Sierra crest. Strong winds will also be
possible over mountain ridges.
Convective parameters still look decent for thunderstorms on
Wednesday, with perhaps a bit more upper support when compared to
today. Convection may be a bit more widespread on Wednesday, but
this will once again depend on how much surface clearing is able
to develop during the period of peak heating (afternoon). Wind
shear profiles look very favorable for rotating updrafts on
Wednesday with long looping hodographs indicative of strongly
veering winds with height. An isolated tornado or two may be
possible depending on whether discrete cells are able to develop.
Showery weather continues Thursday, mainly over the mountains, as
cyclonic NWLY flow remains over NorCal. Deeper moisture with
another system begins to affect the region later Friday and Friday
night.
&&
.Extended Discussion (Saturday through Tuesday)
Extended models in good agreement in bringing next Pacific frontal
system on to the north coast by 12z Saturday. Precipitable water
proggs showing a sub tropical moisture feed of around an inch TPW
so this should be a moderately wet system. Snow levels will start
out fairly high at about 6000 feet but then drop on Sunday as the
colder air behind the cold front filters into the area. By this
time however...most of the precipitation will have ended. Breezy
to windy conditions will accompany this system as well with
moderately tight pressure gradients both surface and aloft
predicted. Showers on Sunday with a brief break Sunday night will
be followed but yet another frontal passage on Monday as models
keep upper level troughing over the eastern Pacific. At this
time...this system does not look as wet as the one moving through
over the weekend but it should be a colder system with snow levels
dropping to between 3000 and 4000 feet by Tuesday morning. Showery
and cool conditions expected to continue through the day Tuesday
with daytime highs expected to remain a few to several degrees
below normal.
&&
.Aviation...
Pacific frontal system pushing on to the north coast this morning
will bring lowering ceilings after 18z today north and west of
about kcic and across most areas of NORCAL by this evening.
Ceilings transitioning from VFR this morning to MVFR over the
valley and foothills this afternoon and evening with rain and a
slight chance of thunderstorms. Coastal mountains becoming IFR
after 18z with IFR conditions over the Sierra Cascade range after
00z for low ceilings and rain and snow. Snow level around 5000
feet. Low ceilings continuing through 12z.
&&
.STO Watches/Warnings/Advisories...
winter storm warning from 3 pm this afternoon to 11 am pdt
thursday above 5500 feet in the west slope northern sierra
nevada...western plumas county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS SACRAMENTO CA
426 AM PDT Tue Mar 25 2014
.Synopsis...
Wet and cooler weather will arrive today and continue through the
weekend. Significant mountain snow and gusty winds are likely with
possible thunderstorms in the Valley.
&&
.Discussion...
Major pattern change begins for interior NorCal today as the
persistent ridge along the west coast gives way to a trough over
the eastern Pacific extending southward from a deep upper low over
the NE Pacific off the coast of BC. A series of weather systems
emanating from this low are forecast to affect the region for at
least the next week or so.
The first in the series of weather systems is presently nearing
the northern CA coast. Radar shows the frontal band just off the
NW coast of CA early this morning, and it will move eastward
across the region today. Precip is expected to begin in the
Redding area this morning, in the Sacramento region this afternoon
and spread east into the northern Sierra by late today or this
evening.
This first system will only bring modest precip totals for the
area. It may also bring a chance of thunderstorms across the
valley later today if the frontal band moves through quick enough
allowing for some clearing late in the day. The latest HRRR times
the back edge of the frontal band through the valley by mid-
afternoon, so this is something to watch this afternoon. Models
continue to show the best instability and surface convergence
across the southern half of the Sacramento Valley southward into
the northern SJ Valley. Snow levels will start initially high
with this system, but rapidly drop below 6000 ft by evening.
Another wave of precip and colder air arrives on Wednesday and
continues into Thursday. With westerly to southwesterly flow
aloft, favorable orographics are expected over the Sierra but may
limit precipitation along the downslope parts of the Sacramento
Valley. Through these two events, potentially up to an inch of
rain will be possible over parts of the Valley. Snow levels will
drop down to around 4000 ft with 4 to 8 inches possible above that
level. Over a foot of snow is expected above 5500 ft with 2 feet
along the northern Sierra crest. Strong winds will also be
possible over mountain ridges.
Convective parameters still look decent for thunderstorms on
Wednesday, with perhaps a bit more upper support when compared to
today. Convection may be a bit more widespread on Wednesday, but
this will once again depend on how much surface clearing is able
to develop during the period of peak heating (afternoon). Wind
shear profiles look very favorable for rotating updrafts on
Wednesday with long looping hodographs indicative of strongly
veering winds with height. An isolated tornado or two may be
possible depending on whether discrete cells are able to develop.
Showery weather continues Thursday, mainly over the mountains, as
cyclonic NWLY flow remains over NorCal. Deeper moisture with
another system begins to affect the region later Friday and Friday
night.
&&
.Extended Discussion (Saturday through Tuesday)...
Extended models in good agreement in bringing next Pacific frontal
system on to the north coast by 12z Saturday. Precipitable water
proggs showing a sub tropical moisture feed of around an inch TPW
so this should be a moderately wet system. Snow levels will start
out fairly high at about 6000 feet but then drop on Sunday as the
colder air behind the cold front filters into the area. By this
time however...most of the precipitation will have ended. Breezy
to windy conditions will accompany this system as well with
moderately tight pressure gradients both surface and aloft
predicted. Showers on Sunday with a brief break Sunday night will
be followed but yet another frontal passage on Monday as models
keep upper level troughing over the eastern Pacific. At this
time...this system does not look as wet as the one moving through
over the weekend but it should be a colder system with snow levels
dropping to between 3000 and 4000 feet by Tuesday morning. Showery
and cool conditions expected to continue through the day Tuesday
with daytime highs expected to remain a few to several degrees
below normal.
&&
.Aviation...
Pacific frontal system pushing on to the north coast this morning
will bring lowering ceilings after 18z today north and west of
about kcic and across most areas of NORCAL by this evening.
Ceilings transitioning from VFR this morning to MVFR over the
valley and foothills this afternoon and evening with rain and a
slight chance of thunderstorms. Coastal mountains becoming IFR
after 18z with IFR conditions over the Sierra Cascade range after
00z for low ceilings and rain and snow. Snow level around 5000
feet. Low ceilings continuing through 12z.
&&
.STO Watches/Warnings/Advisories...
Winter storm warning from 3 pm this afternoon to 11 am pdt thursday
above 5500 feet in the west slope northern sierra nevada...western
plumas county/lassen park.
&&
$$
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1019 AM MDT TUE MAR 25 2014
.UPDATE...
&&
.SHORT TERM...WEB CAMS AND SATELLITE INDICATING LOW CLOUDS
CONTINUE TO DISSIPATE...STILL A BIT ALONG THE FOOTHILLS AND ACROSS
NORTHEAST LARIMER INTO NORTHERN WELD COUNTIES. DRIER AIRMASS ALONG
WITH DAYTIME HEATING WILL HELP DISSIPATE THE LOW CLOUDS. RIDGE
WILL BE OVER THE REGION TODAY BEFORE SHIFTING EAST TONIGHT WITH
MILD TEMPERATURES AND LIGHT WINDS. FORECAST SOUNDINGS INDICATE
HIGHS TO WARM INTO THE 50S...WITH LOWER 60S IN THE DENVER AREA.
OVERALL CURRENT FORECASTS LOOK ON TRACK. WILL MAKE MINOR
ADJUSTMENTS TO TEMPERATURE GRIDS BASED ON CURRENT AND EXPECTED
CONDITIONS.
.AVIATION...CURRENT TAF TRENDS LOOK ON TRACK WITH VFR CONDITIONS
PREVAILING. WITH WEAK DENVER CYCLONE CURRENTLY OVER THE DENVER
AREA...LIGHT SOUTHERLY WINDS EXPECTED TO TREND TOWARD THE
SOUTHEAST BY 18Z. LATEST RAP SHOWS THE WINDS BECOMING EAST
NORTHEAST BETWEEN 18Z AND 20Z. CURRENT TAFS SHOW THIS
TREND...SEEMS REASONABLE AT THIS TIME. DRAINAGE TO DEVELOP DURING
THE EVENING...WITH SOUTHWEST WINDS PREVAILING WEDNESDAY. SOME
GUSTS TO 20 KTS POSSIBLE AFTER 18Z WEDNESDAY.
&&
.PREV DISCUSSION... /ISSUED 734 AM MDT TUE MAR 25 2014/
UPDATE...STRATUS DECK HAS LIFTED TO THE NORTHERN BORDER AREA AS
LOW LEVEL FLOW HAS TURNED MORE SOUTHERLY. STILL A FEW CLOUDS STUCK
ALONG THE FOOTHILLS...BUT THESE TOO WILL BE ERODING IN THE NEXT
COUPLE HOURS. ANY PATCHY FOG THREAT WILL BE ALL BUT GONE IN THE
NEXT HOUR AS WELL AS DAYTIME HEATING BEGINS.
AVIATION...LOW CLOUDS HAVE CLEARED THE FRONT RANGE AIRPORTS...BUT
A FEW PATCHES STILL LINGERED NEAR KBJC. VFR CONDITIONS AND LIGHT
WINDS WILL PREVAIL.
PREV DISCUSSION... /ISSUED 345 AM MDT TUE MAR 25 2014/
SHORT TERM...TODAY AND TONIGHT...AN UPPER LEVEL RIDGE WILL MOVE
ACROSS THE STATE TODAY. LOW CLOUDS WILL PREVAIL THIS MORNING...AND
MAY SEE PATCHY FOG OVER SOME OF THE HIGHER AREAS...MAINLY IN THE
NORTHERN FOOTHILLS AND NEAR THE WYOMING BORDER. ONCE THE LOW CLOUDS
BURN OFF...IT WILL BE A MILD DAY WITH HIGHS IN THE MID TO UPPER 50S
ACROSS NORTHEAST COLORADO. WINDS WILL BE LIGHT AND SKIES WILL BE
MOSTLY SUNNY AS A SURFACE HIGHS SLIDES SOUTH JUST TO THE EAST OF
COLORADO.
THE RIDGE WILL SHIFT EAST OF COLORADO TONIGHT LEAVING A SOUTHWEST
FLOW BEHIND IT. AIRMASS WILL REMAIN DRY. A LEE SIDE TROUGH WILL FORM
OVER EASTERN COLORADO LATE TONIGHT. THIS MAY CAUSE WINDS IN THE
MOUNTAINS AND FOOTHILLS TO INCREASE TOWARDS WEDNESDAY MORNING. THIS
SURFACE TROUGH WILL MAKE FOR A BREEZY WEDNESDAY.
LONG TERM...A SERIES OF SHORTWAVE TROUGHS AND RIDGES TRAVELING IN
A GENTLY UNDULATING ZONAL FLOW ACROSS THE CONTINENTAL U.S. WILL
PROVIDE DAILY VARIATIONS IN TEMPERATURE...SKY COVER AND WINDS
THROUGH NEXT WEEKEND. AN UPPER RIDGE PASSING OVERHEAD TODAY WILL
BE REPLACED BY A SHORTWAVE TROUGH LATE ON WEDNESDAY. MODELS AND A
MAJORITY OF THE GFS ENSEMBLE MEMBERS SHOW THE LEADING EDGE OF THIS
NEXT SHORTWAVE TROUGH MERGING WITH A CLOSED LOW MOVING UP FROM THE
NORTHERN BAJA PENINSULA. THIS LOW OPENS UP AS IT RACES ACROSS
NORTHERN NEW MEXICO AHEAD OF THE MAIN TROUGH OVER THE WEST COAST
EARLY ON WEDNESDAY. WITH THE BULK OF ITS ENERGY AND MOISTURE
PASSING SOUTH OF COLORADO...SEE LITTLE MORE THAN AN INCREASE IN
MID-LEVEL CLOUDS AND WARM AND GUSTY SOUTHWEST WINDS FOR MUCH OF
THE CWFA ON WEDNESDAY. ITS POSSIBLE THAT AREAS ALONG THE FRONT
RANGE AND OVER THE PALMER DIVIDE COULD SEE TEMPERATURES AND RHS
APPROACHING CRITICAL FIRE WEATHER THRESHOLDS WEDNESDAY AFTERNOON.
FOR NOW NO HIGHLIGHTS. MODELS SHOW MOISTURE CONTINUING TO STREAM
INTO THE AREA ON STRENGTHENING SOUTHWEST FLOW WEDNESDAY EVENING
AHEAD OF THE MAIN UPPER TROUGH OVER THE GREAT BASIN. MODELS SHOW
AREAS OF LIGHT QPF DEVELOPING IN THE HIGH COUNTRY DURING THE
EVENING. FCST LAPSE RATES ARE SUCH THAT MOST OF THIS PRECIP WILL
BE SHOWERY IN NATURE WITH THE SNOW LEVEL STARTING OUT AROUND 10
THSND FEET MSL AND LOWERING TO NEAR 6500 FT MSL BY MORNING WITH
THE THERMAL TROUGH PASSING BY. EAST OF THE MTNS...SHOULD SEE SKIES
FILL WITH CLOUDS DURING THE EVENING HOURS AS PER MODEL CROSS
SECTIONS...AND POSSIBLY LOWERING TO JUST OFF THE DECK DURING THE
PRE-DAWN HOURS WITH SCATTERED RAIN/SNOW SHOWERS. MODELS INDICATE
MOST OF THE PRECIP ON THE PLAINS OCCURRING ACROSS NORTHERN AND
EASTERN SECTIONS WITH THE PASSAGE OF A COLD FRONT AFTER MIDNIGHT.
PRECIP AMOUNTS ON THE LOW SIDE BOTH MTNS AND PLAINS...ALTHOUGH
HIGHER WEST FACING SLOPES COULD PICK UP A COUPLE INCHES OF SNOW BY
THURSDAY MORNING. THE NORTHEAST CORNER OF THE STATE MAY ALSO SEE A
QUICK INCH OR SO OF SNOW OVERNIGHT.
THURSDAY THROUGH FRIDAY MORNING...MODELS PORTRAY A PERIOD OF COOLER
AND UNSETTLED WEATHER AS A PAIR OF WEAK MID-LEVEL PERTURBATIONS
SWING ACROSS THE REGION. DIFFICULT TO PIN DOWN ANY SPECIFIC
PERIOD OF PRECIP BASED ON CURRENT MODEL GUIDANCE. ALTHOUGH ODDS
FAVOR PRECIP ON WINDWARD MTN SLOPES WITH COLD AIR ADVECTION WITH
NORTHWEST FLOW. PLAINS ALSO HAVE A SLIGHT CHANCE OF PRECIP DURING
THIS PERIOD...MOST IF NOT ALL OF IT AS RAIN SHOWERS...AND MOST OF
THAT PROBABLY EAST OF THE I-25 URBAN CORRIDOR DUE TO THE DRYING
EFFECTS OF DOWNSLOPE FLOW OFF THE FRONT RANGE. TEMPERATURES BOTH
DAYS NEAR TO SLIGHTLY BELOW AVERAGE. A DRIER AND WARMER WEST-
NORTHWEST FLOW RETURNS TO THE FCST AREA LATE ON FRIDAY.
LOOKING AHEAD TO THE WEEKEND...SATURDAY LOOKS EVEN WARMER AND DRIER
AS MEDIUM RANGE MODELS SHOW AN UPPER RIDGE BUILDING ACROSS THE
STATE. PORTIONS OF NORTHEAST COLORADO COULD SEE 70S FOR HIGHS ON
SATURDAY. BY SUNDAY...WEATHER PICTURE NOT AS CLEAR CUT. MODELS FOR
THE MOST PART SHOW A WEAK SHORTWAVE IN ZONAL FLOW ALOFT MIGRATING
OVER THE AREA DURING THE DAY. MODELS DIFFER AS TO ITS STRENGTH AND
ITS POTENTIAL TO PRODUCE CLOUDS/PRECIP. GFS AND ECMWF HINT AT A FEW
SHOWERS DURING THE AFTERNOON...AND MAINLY OVER THE HIGHER
ELEVATIONS. OTHERWISE SUNDAY LOOKS DRY WITH DAYTIME TEMPERATURES
NEAR AVERAGE IN THE HIGH COUNTRY AND SEVERAL DEGS ABOVE AVERAGE ON
THE PLAINS...ESPLY IN AREAS EXPOSED TO DOWNSLOPE FLOW OFF THE
FOOTHILLS. MONDAY CONTINUES DRY BUT SLIGHTLY COOLER WITH AN UPPER
RIDGE BUILDING TO OUR WEST.
AVIATION...LOW CLOUDS ARE EXPECTED TO PREVAIL THROUGH MID TO
LATE MORNING. CEILINGS SHOULD RANGE FROM 1500 TO 3000 FEET. THERE
IS A CHANCE FOR FOG WITH VISIBILITY BELOW A QUARTER MILE BETWEEN
11 AND 15Z...MAINLY AT KDEN. A WEAK DENVER CYCLONE HAS FORMED AND
IS KNOWN TO BRING IN FOG WITH ITS NORTHWESTERLY WINDS AROUND 12Z
AT KDEN. ONCE THE LOW CLOUDS BURN OFF...MOSTLY CLEAR SKIES WILL
PREVAIL THROUGH TONIGHT. LIGHT WINDS THIS MORNING WILL TURN
SOUTHEAST TODAY AND BECOME SOUTHWEST AFTER 00Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....COOPER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
849 AM EDT TUE MAR 25 2014
.UPDATE...MADE SOME ADJUSTMENTS TO HOURLY CLOUD COVER FORECAST
BASED ON SATELLITE TRENDS SHOWING PARTIAL CLEARING IN OUR WRN
COUNTIES...WITH CLEAR SKIES SPREADING INTO WRN FL PNDL AND SW GA.
WITH SUBSIDENCE MOVING IN...SHOULD SEE CLOUDINESS DECREASE FROM
W TO E OVER OUR FORECAST AREA DURING THE LATE MORNING/EARLY
AFTERNOON HOURS...AS INDICATED IN LATEST HRRR GUIDANCE. CURRENT
HIGH TEMP FORECAST LOOKS GOOD BASED ON AFTERNOON SUNSHINE.
ANTICIPATING BREEZY CONDITIONS ESP IN THE AFTERNOON...LAMP GUID
SUGGESTING GUSTS INTO 26-30KT RANGE...SO LAKE WIND ADVISORY LOOKS
OKAY.
&&
.AVIATION...SATELLITE TRENDS CONFIRM CURRENT TAF FORECAST OF
IMPROVING CONDITIONS THRU EARLY AFTERNOON.
&&
.MARINE...NO CHANGES IN NEXT CWF ISSUANCE WITH INCREASING WINDS/SEAS
EXPECTED. CURRENT HEADLINES LOOK FINE...WITH FREQUENT WIND GUSTS TO
GALE FORCE EXPECTED THIS EVENING ACROSS OFFSHORE COMPONENT.
RIP CURRENTS: MODERATE RISK TODAY WITH LONG-PERIOD NE SWELL AND
ELEVATED SURF. LOW TO MODERATE RISK WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 31 59 37 / 10 0 0 0
SSI 64 37 56 44 / 20 0 0 10
JAX 71 35 58 40 / 10 0 0 10
SGJ 70 41 57 48 / 10 0 0 10
GNV 73 34 61 39 / 10 0 0 10
OCF 76 36 62 40 / 10 0 0 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-FLAGLER-
GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-SUWANNEE-
UNION.
GA...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
APPLING-ATKINSON-BACON-BRANTLEY-COFFEE-JEFF DAVIS-PIERCE-
WAYNE.
LAKE WIND ADVISORY FROM NOON TODAY TO 8 PM EDT THIS EVENING FOR
APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COASTAL
CAMDEN-COASTAL GLYNN-COFFEE-ECHOLS-INLAND CAMDEN-INLAND
GLYNN-JEFF DAVIS-PIERCE-WARE-WAYNE.
AM...SMALL CRAFT ADVISORY UNTIL 7 PM EDT THIS EVENING FOR ALTAMAHA
SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
GALE WARNING FROM 7 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
ALTAMAHA SOUND GA TO FERNANDINA BEACH FL 20 NM TO 60 NM
OFFSHORE-FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM
OFFSHORE-ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM
OFFSHORE.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EDT
WEDNESDAY FOR ALTAMAHA SOUND GA TO FERNANDINA BEACH FL OUT
20 NM-FERNANDINA BEACH TO ST AUGUSTINE FL OUT 20 NM-ST
AUGUSTINE TO FLAGLER BEACH FL OUT 20 NM.
&&
$$
WOLF/HESS
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
430 AM EDT Tue Mar 25 2014
.Near Term [Through Today]...
Latest MSAS and RAP analysis at 07z indicated that a surface low was
beginning to take shape just east of the Florida peninsula. A
surface trough extending from near AAF north-northeast to W NC was
maintaining light surface winds and higher dew points across our area
early this morning. Meanwhile, drier and cooler air was beginning to
make a more substantial push into the rest of AL and MS as the
surface pressure gradient begins to increase between the developing
low and a high building into the Plains. This drier air should begin
arriving into our area over the next 6 hours, and will help scour
out clouds from west to east. This process is likely already
beginning per 11-3.9 micron satellite loops.
Therefore, we expect a mostly sunny day. As the surface cyclone
begins to rapidly deepen off the coastal Carolinas and the surface
ridge axis moves closer to the Mississippi River, the pressure
gradient should increase markedly - with NW winds likely to reach
15-25 mph during the afternoon hours. Along with gusts up to 30-35
mph, this falls short of our Wind Advisory criteria. Basically, we
are expecting a breezy day, but no headlines are currently
anticipated. CAA in the boundary layer will continue through the
day, and thus that layer should be slightly cooler in the mid-late
afternoon. As a result, we placed the warmest temperatures closer
to midday, with highs overall in the 60s, and a small area of low
70s in the eastern Florida Big Bend and immediate Valdosta area.
.Short Term [Tonight Through Thursday]...
The system developing off the FL coast is destined to bomb in
rather spectacular fashion as it races northeastward well off the
Eastern Seaboard. In the wake of the low, strong high pressure
will build southeast to the Tennessee Valley by Wednesday morning.
This airmass is of modified arctic origin and will bring
unseasonably cold temperatures to the Gulf Coast. The high
position is not ideal for efficient radiational cooling, but we
should see enough cold advection to bring temps down to around
freezing by dawn Wednesday across our northern zones. The coldest
areas in Coffee County may see the required 2-hr durations for a
warning, but most areas are expected to only just touch freezing.
Because of the marginal nature of this event, we plan to leave the
freeze watch in place after coordination with WFO JAX and let the
day shift make the final call after they get a look at one more
suite of guidance. People that have sensitive plants and are
concerned about freezing temps should not wait for the warning to
begin taking protective actions. A few spots could even see some
frost, which would be another concern, but the current thinking is
that will see just enough wind to prevent frost formation in most
areas, and particularly in wooded and urban areas, which are also
less likely to see freezing temps. Daytime highs on Wednesday will
only reach the upper 50s in AL and GA and lower 60s in FL. This is
below normal even for January and some 13-15 degrees below seasonal
levels.
The surface high will build east and move off the NC coast by
Thursday afternoon. This will swing low level winds around to
onshore which will allow temps to moderate. Min temps will mainly be
in the upper 30s inland Wednesday night. We cannot rule out some
patchy frost over the Suwannee Valley early Thursday morning where
some mid 30s will be possible. After that, afternoon temps will
recover nicely to the upper 60s and lower 70s. We will also maintain
a slight chance for showers on Thursday for the southern zones.
.Long Term [Thursday Night Through Tuesday]...
We`ll transition out of an unseasonably cool and dry pattern into
a wet pattern with more seasonable temperatures through the
extended range forecast. A frontal system will enter the Tri-State
region on Friday, and not completely clear out until sometime on
Sunday when conditions will begin to dry out once again.
&&
.Aviation...
[Through 06Z Wednesday] Any lingering MVFR or low-end VFR CIGS this
morning should quickly dissipate by 12-15z. Thereafter, we expect
clear skies and VFR conditions. Winds should be out of the northwest
at about 310-330 degrees today, and will be gusty especially from
15-23z. Maximum gusts could reach into the 25-30 knot range, which
could cause some crosswind concerns on SW-NE or W-E runways. Winds
should begin to diminish after 23z.
&&
.Marine...
Deepening low pressure off the Southeast U.S. coast will combine
with strong high pressure building into the Mississippi and
Tennessee Valleys to produce a strengthening pressure gradient
across the Northeast Gulf of Mexico today. Winds will increase to
small craft advisory levels and remain elevated through the night.
Conditions will briefly subside below headline criteria Wednesday
afternoon before increasing to cautionary or marginal advisory
levels Wednesday night into Friday. This time the winds will be
onshore ahead of our next frontal system which will reach or cross
the waters on Saturday.
&&
.Fire Weather...
Dry air should begin arriving today, and in particular this
afternoon. Although forecast models are a little inconsistent in how
low to drop dew points, the most likely scenario creates widespread
minimum RH of around 23-25%. RH values that low put red flag
criteria in play in all of our zones today. Details follow.
* For Alabama: we should see a combination of RH below 25% and winds
of 20 mph. Therefore, a Red Flag Warning will be issued for today.
* For Georgia: it appears likely that we will see RH reach 25% in
combination with winds of at least 15 mph. The questionable part
of the criteria for today will be 10-hr fuel moisture. Yesterday,
these levels dropped to around 7% in the mid-late afternoon near
the northern part of our forecast area at Americus, and were
slightly higher (8%) at Camilla. Based on dry, windy, and sunny
weather today and a forecast for 6% fuel moisture at Americus
from the GA Forestry Commission - we expect that northern parts
of our area may reach red flag criteria. However, the values are
likely to be higher at Camilla and Adel. Therefore the RFW area
that has been issued for SW GA was placed further north and
coordinated with WFO FFC.
* For Florida: forecast ERC values are not sufficiently high to
warrant a Red Flag Warning for any combination of criteria.
By tomorrow, winds will diminish, which makes it unlikely that red
flag conditions will occur Wednesday in our GA or FL zones. However,
long durations of low RH may occur in SE Alabama so a Fire Weather
Watch was posted for those areas.
&&
.Hydrology...
Most rivers across the region have crested and are slowly receding
with only a few points still above flood stage. The Ochlockonee at
Havana and Aucilla at Lamont will fall below flood stage later
today. The Withlacoochee near Quitman doesn`t have far to go either.
The Lower Withlacoochee and Suwannee Rivers continue to rise and
will likely continue to do so through the weekend. However, the
chance of flooding is low.
For the latest river stages and forecasts, please visit:
water.weather.gov/ahps2/index.php?wfo=tae
&&
.Preliminary Point Temps/PoPs...
Tallahassee 69 34 62 39 71 / 10 0 0 0 20
Panama City 67 39 60 47 68 / 10 0 0 10 20
Dothan 63 32 60 41 70 / 0 0 0 0 10
Albany 64 31 59 39 70 / 0 0 0 0 10
Valdosta 71 32 61 38 73 / 10 0 0 0 10
Cross City 72 34 62 36 72 / 10 0 0 0 20
Apalachicola 69 38 60 46 67 / 10 0 0 0 20
&&
.TAE Watches/Warnings/Advisories...
FL...Freeze Watch from late tonight through Wednesday morning for
Holmes-Inland Walton.
GA...Freeze Watch from late tonight through Wednesday morning for
Baker-Ben Hill-Berrien-Calhoun-Clay-Colquitt-Cook-Dougherty-
Early-Irwin-Lee-Miller-Mitchell-Quitman-Randolph-Terrell-
Tift-Turner-Worth.
Red Flag Warning from 2 PM this afternoon to 8 PM EDT this
evening for Ben Hill-Calhoun-Clay-Dougherty-Early-Lee-
Quitman-Randolph-Terrell-Turner-Worth.
AL...Freeze Watch from late tonight through Wednesday morning for
Coffee-Dale-Geneva-Henry-Houston.
Red Flag Warning from 1 PM this afternoon to 7 PM CDT this
evening for Coffee-Dale-Geneva-Henry-Houston.
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for Coffee-Dale-Geneva-Henry-Houston.
GM...Small Craft Advisory from 11 AM this morning to 11 AM EDT
Wednesday for Apalachee Bay-Coastal waters From Ochlockonee
River to Apalachicola FL out to 20 NM-Coastal waters from
Suwannee River to Keaton Beach FL out 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...LAMERS
SHORT TERM...WOOL
LONG TERM...HARRIGAN
AVIATION...LAMERS
MARINE...WOOL
FIRE WEATHER...LAMERS
HYDROLOGY...WOOL
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1027 PM EDT WED MAR 26 2014
.SYNOPSIS...
HIGH PRESSURE WILL HOLD ACROSS THE REGION OVERNIGHT. A SOUTHERLY
FLOW WILL DEVELOP THURSDAY AS THE HIGH SHIFTS OFF THE COAST
ALLOWING TEMPERATURES TO MODERATE. INCREASING CHANCES OF RAIN WILL
RETURN TO THE AREA FOR THURSDAY NIGHT THROUGH SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
SURFACE HIGH PRESSURE CENTERED ALONG THE EAST COAST IS PROVIDING
NEARLY IDEAL RADIATIONAL COOLING CONDITIONS THIS EVENING UNDER
CLEAR SKIES AND CALM WINDS. TEMPERATURES DROPPED VERY QUICKLY
AFTER SUNSET AS THE BOUNDARY LAYER SEALED OFF AND A STRONG
INVERSION HAS SET UP WITH PARTS OF THE NORTHERN MIDLANDS ALREADY
IN THE LOWER 30S.
LITTLE CHANGE TO PREVIOUS FORECAST WITH FREEZE WARNING CONTINUING
LATE TONIGHT INTO EARLY THURSDAY MORNING. DID LOWER TEMPERATURES A
COUPLE OF DEGREES IN THE FAR NORTHERN MIDLANDS WHERE TEMPERATURES
WERE ALREADY APPROACHING FORECAST LOWS. SATELLITE IMAGERY SHOWING
SOME HIGH CLOUDS APPROACHING FROM THE WEST LATE TONIGHT BUT DO NOT
THINK IT WILL ARRIVE IN TIME TO HAVE MUCH EFFECT ON OVERNIGHT
LOWS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
THURSDAY AND THURSDAY NIGHT...HIGH PRESSURE WILL BE ALONG THE ATLANTIC
COAST THURSDAY MORNING AND PUSH INTO THE ATLANTIC BASIN THURSDAY
AFTERNOON AS LOW PRESSURE DEEPENS AND TRACKS INTO THE WESTERN
GREAT LAKES REGION. THIS WILL BRING SOUTHERLY FLOW BACK TO THE
REGION WITH CLOUDS SLOWLY INCREASING. WEAK COLD FRONT WILL MOVE
THROUGH THE GULF STATES THURSDAY NIGHT AND APPROACH THE UPSTATE BY
DAYBREAK FRIDAY. HAVE KEPT THE SLIGHT CHANCE OF SHOWERS FOR
THURSDAY NIGHT ACROSS THE WESTERN MIDLANDS AND CSRA...AND EXPANDED
SLIGHTLY EASTWARD INTO THE CENTRAL MIDLANDS. DAYTIME TEMPERATURES
THURSDAY WILL BE IN THE MIDDLE TO UPPER 60S WITH OVERNIGHT LOWS IN
THE MIDDLE 40S TO AROUND 50.
FRIDAY AND FRIDAY NIGHT...COLD FRONT WILL MOVE TOWARD THE FORECAST
AREA ON FRIDAY...BUT WEAKEN BEFORE IT REACHES THE CWA. SURFACE WINDS
WILL REMAIN FROM THE SOUTHEAST/SOUTHWEST THROUGH THE PERIOD.
ISENTROPIC LIFT WILL BE ON THE INCREASE BY THURSDAY NIGHT INTO
FRIDAY ESPECIALLY LATE THU NIGHT. WITH MID/UPPER FLOW FROM THE SW
AND INCREASING ISENTROPIC LIFT...HAVE KEPT LIKELY POPS FOR
FRIDAY/FRIDAY EVENING. WITH SHOWERS ALONG WITH AN ISOLATED
THUNDERSTORM. CONFIDENCE IN RAINFALL AMOUNTS REMAINS LOW.
CURRENTLY EXPECT MOST LOCATIONS TO RECEIVE ONE QUARTER INCH OF
RAINFALL OR LESS FOR FRIDAY AND FRIDAY NIGHT. TEMPERATURES FRIDAY
WILL BE IN THE UPPER 60S TO MIDDLE 70S WITH LOWS FRIDAY NIGHT
GENERALLY IN THE MIDDLE 50S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
MODELS ARE IN PRETTY GOOD AGREEMENT THROUGH THE LONG TERM WITH
SOME POSITION AND INTENSITY DIFFERENCES NOTED. ON SATURDAY LOW
PRESSURE WILL DEVELOP OVER THE TN VALLEY ALONG THE REMAINS OF THE
FRONTAL BOUNDARY. THE LOW WILL TRACK NORTHEASTWARD THROUGH THE DAY
SATURDAY AND BRING A COLD FRONT ACROSS THE AREA SATURDAY AFTERNOON.
THE NEXT BEST CHANCE FOR SHOWERS/THUNDERSTORMS WILL BE
AHEAD/ALONG THE FRONT ON SATURDAY. DEWPOINTS WILL BE INCREASING
ALONG WITH PW VALUES AND THE AIRMASS WILL BECOME WEAKLY UNSTABLE
WITH AFTERNOON HEATING. DRIER AIR WILL BEGIN ENTERING THE REGION
SATURDAY NIGHT INTO SUNDAY AS HIGH PRESSURE BUILDS BACK INTO THE
REGION. HIGH PRESSURE WILL DOMINATE THE REGION THROUGH MONDAY WITH
MODELS DIFFERING FOR MONDAY NIGHT ONWARD. EACH OF THE MODELS BRING
ANOTHER LOW PRESSURE SYSTEM INTO THE EASTERN US WITH THE GFS BEING
MORE VIGOROUS THAN THE ECMWF. WITH THE MODEL DIFFERENCES KEEPING
CONFIDENCE LOW HAVE MADE ONLY COSMETIC CHANGES TO THE FORECAST FOR
MONDAY NIGHT AND TUESDAY. TEMPERATURES THROUGH THE LONG TERM WILL
GENERALLY BE NEAR NORMAL.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE 24 HOUR TAF FORECAST
PERIOD.
HIGH PRESSURE OVER THE REGION TONIGHT WILL MOVE OFFSHORE THURSDAY.
NEAR CALM WINDS EXPECTED OVERNIGHT WITH HIGH CLOUDS MOVING INTO THE
REGION BY SUNRISE. RAP AND NAM BUFKIT INDICATING THE DEVELOPMENT OF
A LOW LEVEL JET AFTER 06Z...WHICH COULD LEAD TO A PERIOD OF LLWS
THROUGH 15Z. GIVEN LOW CONFIDENCE...WILL NOT INCLUDE LLWS IN TAFS AT
THIS TIME. NO FOG IS EXPECTED OVERNIGHT GIVEN LOW LEVEL DRY AIR.
BOUNDARY LAYER MIXING WILL COMMENCE BY 15Z WITH WINDS BECOMING
SOUTHEAST 5 TO 10 KNOTS.
EXTENDED AVIATION OUTLOOK...AN ONSHORE FLOW AHEAD OF A FRONTAL
SYSTEM COULD BRING WIDESPREAD IFR OR MVFR CONDITIONS LATE THURSDAY
NIGHT. RESTRICTIONS ASSOCIATED WITH THE FRONT...INCLUDING SHOWERS
AND THUNDERSTORMS...WILL LIKELY OCCUR FRIDAY AND SATURDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR SCZ015-016-
018-020>022-025>031-035>038-041.
GA...FREEZE WARNING FROM 2 AM TO 9 AM EDT THURSDAY FOR GAZ040-
063>065-077.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
222 PM MDT TUE MAR 25 2014
.SHORT TERM...YESTERDAY THE GFS CONSOLIDATED THE SPLITTING TROUGH AS IT MOVED
THROUGH SOUTHEAST IDAHO ON WEDNESDAY WHILE THE OTHER MODELS
MAINTAINED THE STRETCHING/SPLITTING SCENARIO. TODAY THE GFS IS BACK
TO STRETCHING THE TROUGH WITH MORE ENERGY CROSSING SOUTH OF THE
STATE. NICE TO HAVE SOME CONSISTENCY. HANDLING OF COLD AIR ADVECTION
HAS ALSO BEEN DIFFICULT. THE 12Z NAM12 RUN LOWERED SNOW LEVELS FOR
WEDNESDAY MORNING TO A LITTLE BELOW 5000 FEET ELEVATION. AT THE SAME
TIME SURFACE TEMPERATURES SHOULD BE ABOVE FREEZING...THEREFORE DID A
LITTLE COMPROMISE ON SNOW LEVELS. COLD FRONT SHOULD COME THROUGH 6-9
AM MDT WEDNESDAY. PLANNING ON ENOUGH RAIN WITH THE FRONT TO WET THE
DIRT BEFORE WINDS COME UP. CONFIDENCE IN THUNDERSTORMS IS NOT HIGH
BUT LAPSE RATES ARE PRETTY STEEP...MAY EVEN GET SOME ICE OR SNOW
PELLETS WITH CONVECTIVE SHOWERS. ALSO REJECTED THE NAM MOS WINDS OF
30 KTS AT POCATELLO...BLAMING IT PARTLY ON THE HANDLING OF COLD
AIR...PREFERENCE GFS MOS KEEPING WINDS 15 TO 25 MPH RANGE IN THE
LOWER SNAKE PLAIN AND EAST MAGIC VALLEY. FOR THURSDAY...SURFACE
PRESSURE GRADIENT...COLD AIR ADVECTION AND UPPER LEVEL WINDS ALL
SUPPORT STRONGER WINDS OF 25 TO 35 MPH WITH GUSTS INTO THE 40S. FOR
SNOW AMOUNTS BETWEEN MIDNIGHT TONIGHT THROUGH MIDNIGHT WEDNESDAY
NIGHT...FAVOR 1 TO 3 INCHES ABOVE 5500 FEET...MAYBE LOCAL 4 INCHES
ON WEST FACING SLOPES NEAR SUN VALLEY AND MACKS INN. MIDNIGHT
WEDNESDAY NIGHT TO FRIDAY MORNING...DEEPER MOISTURE SURGES ACROSS
THIS AREA WITH ACCUMULATION UP TO 6 INCHES HIGHER ELEVATIONS OF THE
CENTRAL MOUNTAINS AND PERHAPS THE NORTHERN WASATCH RANGE...AND
MOUNTAIN TOP WINDS APPROACH 30 TO 40 MPH. THERE IS A GOOD CHANCE A
WINTER WEATHER ADVISORY WILL BE NEEDED FOR THE MOUNTAINS AND AT
LEAST A WIND ADVISORY IN THE SNAKE PLAIN. CONTRARY TO YESTERDAYS GFS
MODEL...THIS FRIDAY SHOULD HAVE A BREAK IN PRECIPITATION WHILE A
SHORT WAVE RIDGE MOVES THROUGH BEFORE THE NEXT STORM SYSTEM.
RS
.LONG TERM...FRI NIGHT THROUGH NEXT TUE NIGHT. HUGE DIFFERENCES HAVE
DEVELOPED BETWEEN THE GFS AND ECMWF. THE 25/12Z GFS APPEARS TO
HAVE...PERHAPS...DEVELOPED A CONVECTIVE FEEDBACK THAT HAS SENT THE
QPF PRODUCTION TO GOING CRAZY. AS MUCH AS 1.22 INCHES PRODUCED IN 12
HOURS IN THE CENTRAL IDAHO MOUNTAINS WHILE THE ECMWF HAS LESS THAN
1/2 OF THAT AMOUNT. HAVENT MADE MUCH CHANGE DURING THE TIME PERIOD.
MAINLY CORRECTED FOR BORDER ISSUES AND TRIED TO SPLIT THE DIFFERENCE
FOR THE FIRST FOUR PERIODS WHEN IT COMES TO POP AND SKY. TIMING HAS
ALSO SLIPPED OUT OF AGREEMENT FOR MOST TIME PERIODS. VERY LOW
CONFIDENCE FORECAST ALL AROUND. MESSICK
&&
.AVIATION...LARGE DIFFERENCES SURFACED BETWEEN NAM AND GFS. THE GFS
HAS STAYED DRY FOR TONIGHT...WHILE THE NAM HAS BECOME MUCH WETTER.
THIS HAS LED TO THE NAM PREDICTING MARGINAL VFR CIGS AND RAIN FOR
WED EARLY MORNING. DID NOT HAVE THE HRRR GUIDANCE FOR WINDS AND THE
NAM HAS SOME STRONGLY CHANGING DIRECTIONS AND SPEEDS EVERY THREE
HOURS. SOMEWHAT LOW CONFIDENCE IN THIS FORECAST...BUT HAVE LEFT THE
CIGS ABOVE THE MARGINAL VFR THRESHOLD. HRRR HAS JUST SINCE RESTARTED
AND MAY BE OF USE IN SUBSEQUENT FORECASTS WHEN IT HAS FULLY COME IN.
THE MAIN FORECAST PROBLEM IS JUST BEYOND THE 26/18Z END TIME OF THE
CURRENT TAFS WHEN NAM GOES FOR 30KT SUSTAINED WIND V. 16KT SUSTAINED
WIND OF THE GFS. CURRENTLY BELIEVE THAT THE GFS HAS BEEN MORE
CONSISTENT AND RELIABLE...THUS BELIEVE THE DRIER AND CALMER SCENARIO
FOR NOW. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
221 PM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON.
* POSSIBLE GUSTY SOUTH/SOUTHEAST WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK UPPER TROUGH IS PASSING SOUTHEAST OF THE AREA EARLY THIS
AFTERNOON. SCATTERED FLURRIES AND A FEW SNOW SHOWERS WILL END AND
BKN 4KFT CIGS WILL GRADUALLY SCATTER OUT THROUGH THE AFTERNOON
WITH SKC EXPECTED TONIGHT.
WINDS WILL REMAIN STRONG/GUSTY FROM THE NORTHWEST WITH GUSTS INTO
THE MID 20KT RANGE. SPEEDS/GUSTS WILL QUICKLY DIMINISH WITH SUNSET
AND THEN BECOME LIGHT AND VARIABLE OVERNIGHT INTO WEDNESDAY
MORNING AS A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA. WINDS
WILL TURN BACK SOUTHERLY WEDNESDAY MORNING AND INCREASE IN SPEEDS
DURING THE AFTERNOON...POSSIBLY BECOMING MORE SOUTH/SOUTHEAST
LATER WEDNESDAY AFTERNOON OVER THE CHICAGO AREA TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
219 PM CDT
AN ACTIVE EARLY SPRING WEATHER PATTERN WILL BE SEEN OVER THE GREAT
LAKES THROUGH THIS NEXT WEEK. FIRST IS THE ONGOING WIND EVENT. THE
GUSTY NORTHWEST WIND WILL EASE THIS EVE HOWEVER WAVES WILL BE SLOW
TO SUBSIDE ALONG THE ILLINOIS AND ESPECIALLY INDIANA NEARSHORE.
HIGH PRESSURE WILL BRIEFLY PREVAIL EARLY WEDNESDAY BEFORE A
STRENGTHENING SOUTHERLY WIND ENSUES. THIS WILL BE IN ADVANCE OF A
MARKEDLY DEEP LOW PRESSURE ACROSS THE UPPER TO CENTRAL
PLAINS...WHICH LOOKS TO MOVE OVER OR NEAR LAKE MICHIGAN ON
THURSDAY NIGHT. BECAUSE OF THE MAGNITUDE OF THE LOW...THE
SUSTAINED WINDS LOOK TO BE 20-30 KT OVER THE LAKE BUT DUE TO THE
STRENGTH OF THE INVERSION...THE GUST-TO-SUSTAINED RATIO LOOKS TO
BE LOW. THIS MAY END UP NEEDING A GALE HEADLINE FOR WEDNESDAY
NIGHT INTO THURSDAY...BUT CONFIDENCE ON THAT WAS TOO LOW AT THIS
TIME. BEHIND THIS SYSTEM ON FRIDAY THERE WILL BE A WINDOW FOR
GUSTY NORTHWEST WINDS...HOWEVER AT THIS TIME THIS PERIOD IS
FAVORED TO REMAIN BELOW GALE FORCE. ANOTHER SYSTEM IS ALREADY
INDICATED TO PASS OVER THE GREAT LAKES REGION EARLY NEXT WEEK AS
THE PROGRESSIVE PATTERN PERSISTS.
HAVE GONE AHEAD AND INCLUDED WAVES FOR ALL OPEN WATER ZONES IN THE
GLF AS ICE CONTINUES TO DIMINISH PER VISIBLE SATELLITE TRENDS.
CERTAINLY STILL SOME LOCKED ICE OUT THERE...ESPECIALLY IN THE
NORTHWEST-MOST ZONES. GIVEN THE UPCOMING TURBULENT PATTERN
CONTINUING...AM NOT EXPECTING THE ICE TO HAVE MUCH CHANCE TO GROW.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1226 PM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON.
* POSSIBLE GUSTY SOUTH/SOUTHEAST WINDS WEDNESDAY AFTERNOON. CMS
//DISCUSSION...UPDATED 18Z...
A WEAK UPPER TROUGH IS PASSING SOUTHEAST OF THE AREA EARLY THIS
AFTERNOON. SCATTERED FLURRIES AND A FEW SNOW SHOWERS WILL END AND
BKN 4KFT CIGS WILL GRADUALLY SCATTER OUT THROUGH THE AFTERNOON
WITH SKC EXPECTED TONIGHT.
WINDS WILL REMAIN STRONG/GUSTY FROM THE NORTHWEST WITH GUSTS INTO
THE MID 20KT RANGE. SPEEDS/GUSTS WILL QUICKLY DIMINISH WITH SUNSET
AND THEN BECOME LIGHT AND VARIABLE OVERNIGHT INTO WEDNESDAY
MORNING AS A RIDGE OF HIGH PRESSURE PASSES OVER THE AREA. WINDS
WILL TURN BACK SOUTHERLY WEDNESDAY MORNING AND INCREASE IN SPEEDS
DURING THE AFTERNOON...POSSIBLY BECOMING MORE SOUTH/SOUTHEAST
LATER WEDNESDAY AFTERNOON OVER THE CHICAGO AREA TERMINALS. CMS
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
1106 AM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
//PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CHANCE OF FLURRIES/LIGHT SNOW SHOWERS THROUGH EARLY AFTERNOON.
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM FOR FLURRIES/LIGHT SNOW SHOWERS THROUGH EARLY AFTERNOON.
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THIS EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1034 AM CDT TUE MAR 25 2014
.DISCUSSION...
1035 AM CDT
THERE WERE MAINLY JUST SOME TWEAKS TO HOURLY CONDITIONS FOR THE
FORECAST THE REST OF TODAY...OTHERWISE ALL IS IN GOOD SHAPE.
THE 12Z RAOBS INDICATED 850-500MB READINGS THAT WERE ABOUT AS
COLD AS THEY CAN REACH IN THIS REGION DURING LATE MARCH. THE
850-925MB COLD AIR ADVECTION IS AT IS MAX OVER THE CWA LATE THIS
MORNING...WITH -18C KNOCKING ON THE DOOR PER THE RAP ANALYSIS.
THIS AIDED BY A SHEARED SHORT WAVE LOOK TO KEEP SCATTERED LIGHT
SNOW SHOWERS/FLURRIES GOING INTO EARLY AFTERNOON. REMARKABLY DRY
LOW-LEVEL AIR LOOKS TO SPREAD IN BY MID-AFTERNOON WITH UPSTREAM
DEW POINT OBSERVATIONS IN THE LOWER TO MID SINGLE DIGITS. THE
SURFACE PRESSURE GRADIENT REMAINS TIGHT AND SOUNDINGS SUPPORT
GUSTS THROUGH THE AFTERNOON...WITH A RELAXING GRADIENT MOVING
QUICKLY IN THIS EVENING AS HIGH PRESSURE BUILDS IN FROM THE PLAINS.
MTF
&&
.PREV DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* CHANCE OF FLURRIES/LIGHT SNOW SHOWERS THIS MORNING.
* STRONG/GUSTY NORTHWEST WINDS THROUGH LATE AFTERNOON. CMS
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM FOR FLURRIES/LIGHT SNOW SHOWERS THIS MORNING.
* HIGH FOR WIND SPEEDS/GUSTS/DIRECTIONS THROUGH THIS EVENING. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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
NWS CHICAGO/ROMEOVILLE IL
655 AM CDT TUE MAR 25 2014
.DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* LOW CHANCE OF FLURRIES OR LIGHT SNOW SHOWERS DURING MID-LATE AM.
* NORTHWEST WINDS GUSTING TO 25 KT FROM MID MORNING THROUGH LATE
AFTERNOON.
RC
//DISCUSSION...UPDATED 12Z...
TODAY WILL BE A WINDY AND VFR DAY IN BETWEEN LOW PRESSURE MOVING
EAST AND EXPANSIVE ARCTIC HIGH PRESSURE SPREADING SOUTHEAST FROM
THE NORTHERN PLAINS. NORTHWEST WINDS WILL GUST TO THE MID-HIGH
20S KTS FROM 14 OR 15Z THROUGH MID TO LATE AFTERNOON. THE ONLY
MINOR CONCERN IS WITH AN UPPER DISTURBANCE CURRENTLY PRODUCING
ISOLATED/SCT SHSN OVER NORTHEAST IA AND SOUTHWEST WI. THIS
DISTURBANCE WILL MOVE SOUTHEAST AND LIGHT SNOW SHOWERS OR FLURRIES
COULD MOVE OVER THE AREA FROM MID TO LATE MORNING. HAVE LEFT THE
TAFS DRY...BUT WILL NEED TO MONITOR TRENDS OVER THE NEXT FEW
HOURS. BEST FORCING WILL BE MAINLY WEST/SW OF THE TAF SITES...SO
IT APPEARS RFD WOULD HAVE A BETTER BUT STILL LOW CHANCE AT
ANYTHING MORE THAN FLURRIES. FORECAST SOUNDINGS INDICATE THAT
DIURNALLY DRIVEN SCT TO BKN VFR CLOUDS WILL BE AROUND 4-5KFT AGL.
AS HIGH PRESSURE MOVES OVERHEAD TONIGHT...SKIES WILL CLEAR AND
WINDS QUICKLY DIMINISH...WITH LIGHT/VRB TO CALM OVERNIGHT INTO
EARLY WEDS. LIGHT SOUTHERLY WINDS WILL DEVELOP WEDNESDAY MORNING
AS THE HIGH PRESSURE SLIDES EAST.
RC
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH THAT THERE WILL BE NO SIGNIFICANT IMPACTS FROM PSBL
-SHSN NEARBY MID-LATE AM.
* HIGH IN WIND/GUST TRENDS AND REMAINING FORECAST ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...CHANCE OF RA AND MVFR. MAY START AS RA/SN MIX.
THURSDAY...PERIODS OF SHRA AND SUB VFR LIKELY. GUSTY SOUTH WINDS.
FRIDAY...VFR PROBABLE. WIND SHIFT TO NORTHEAST LATE DAY. SLIGHT
CHANCE -SN FRIDAY NIGHT.
SATURDAY...VFR LIKELY. NORTHEAST TO EAST WINDS.
SUNDAY...VFR. GUSTY SOUTH-SOUTHWEST WINDS. SLIGHT CHANCE SHRA SUN.
NIGHT.
MONDAY...CHANCE SHRA AND SUB VFR. GUSTY SOUTHWEST WINDS.
RC
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES. WILL NEED A SMALL
CRAFT ADVISORY FOR THE NEARSHORE WATERS AND DID MENTION POTENTIAL
FOR A FEW GALE FORCE GUSTS AFTER MIDNIGHT WEDNESDAY NIGHT.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. GALES ARE POSSIBLE FOR THE NEARSHORE PART OF THURSDAY DUE
TO PROXIMITY TO BETTER MIXED LAND AREA. AFTER THE LOW CROSSES THE
LAKE THURSDAY NIGHT...THE TRAILING COLD FRONT WILL SWEEP ACROSS
THE LAKE...WITH WINDS SHIFTING NORTHWEST TO 25 TO 30 KT INTO
FRIDAY BEFORE BACKING NORTHERLY AND GRADUALLY DIMINISHING IN THE
AFTERNOON. ANOTHER LOW WILL TRACK ACROSS THE OHIO VALLEY EARLY
SATURDAY AND IF IT GETS CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON
SOUTH HALF COULD BE STRONGER THAN INDICATED. WINDS WILL TURN
SOUTHERLY AND INCREASE ON SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE
OF ANOTHER STRONG LOW PRESSURE AREA THAT WILL MOVE ACROSS THE
REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
&&
$$
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
635 AM CDT Tue Mar 25 2014
.DISCUSSION...
ISSUED 253 AM CDT Tue Mar 25 2014
SHORT TERM...Today through Thursday
07z/2am radar imagery shows two bands of snow across central
Illinois...one along the I-55 corridor and one further west in the
Illinois River Valley. Based on radar timing tools and 05z HRRR,
snow will be east of I-57 by 12z, then will quickly exit into
Indiana by mid-morning. Will therefore hold on to low chance POPs
across the far E/SE KILX CWA through 15z, followed by dry
conditions across the board through the balance of the day. Sky
cover forecast will be a bit tricky today, as clearing immediately
behind the snow bands may be muddled by SCT-BKN clouds currently
upstream over Minnesota/northern Iowa. HRRR hints that this cloud
cover will filter southward into the area, resulting in a partly
sunny day. Main story will be the breezy and unseasonably cold
conditions. With temperatures hovering in the 30s and strong
northwesterly winds gusting to between 20 and 30mph, wind-chill
values will remain in the teens.
Clouds will clear out toward sunset as high pressure builds in
from the west. Thanks to clear skies and decreasing winds beneath
the ridge axis, a very cold night is in store with lows dipping
into the teens. High will quickly shift off to the east on
Wednesday allowing a warming trend to begin. Despite full
sunshine, will undercut numeric guidance by a couple of degrees
due to southeasterly component of return flow on back side of
departing high. Resulting high temperatures will remain in the
lower to middle 40s.
Models continue to markedly increase WAA Wednesday night, with all
solutions bringing rain showers into the area overnight. Think
this looks reasonable given strengthening low-level southerly flow
and moistening forecast soundings. In addition, precip coverage
will be enhanced by a lead short-wave ejecting northeastward out
of the Southern Plains. Have therefore bumped POPs to likely after
midnight. Thursday appears to be a windy and wet day, with
numeric guidance suggesting southerly winds gusting to around 30
mph. This will push highs well into the 50s. Increasing elevated
instability could lead to a few rumbles of thunder as well,
particularly as initial short-wave passes through the area. Main
convective event still looks likely for Thursday evening as cold
front pushes into central Illinois. Will continue with likely POPs
for showers and thunderstorms at that time.
LONG TERM...Friday through Monday
00z Mar 25 models are now in good agreement with timing of
departing front late Thursday night, resulting in a cooler and
drier day on Friday. Given model consensus, have removed shower
chances on Friday except across the far E during the morning.
Despite FROPA, a new fly-in-the-ointment has developed for the end
of the week. Both the GFS and ECMWF now develop a secondary
surface low along the trailing end of the front Friday night.
ECMWF had previously shown this feature on a few prior runs, but
never with any consistency. GFS on the other hand had always
advertised a clean FROPA with no secondary wave. GEM also shows
this wave, so given consensus among the three models, confidence
is growing that light precip may return to part of the area Friday
night. At this point, will focus low chance POPs across only the
southern CWA along/south of I-70 in closer proximity to the low
with dry conditions further north across the remainder of the
area. After that, upper heights rise considerably as ridge builds
across the central CONUS. As a result, temperatures will rise back
above normal, with readings climbing well into the 60s for Sunday
and Monday.
Barnes
&&
.AVIATION...
ISSUED 635 AM CDT Tue Mar 25 2014
Gusty northwest winds are expected across the central Illinois
terminals today in the wake of the overnight cold front. Gusts as
high as 25-30 kts are likely at times. Winds will die off this
evening and trend variable as high pressure builds into the area.
Expect VFR conditions to prevail through the 12Z TAF valid time.
Isolated streaks of clouds and even some flurries extend upstream
into the Upper Midwest. However, these features should remain isolated
and have not included them in the terminals at this time.
Bak
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
357 AM CDT TUE MAR 25 2014
.DISCUSSION...
NARROW BUT INTENSE BAND OF SNOW ALONG COLD FRONT WILL CONTINUE TO
MOVE ACROSS THE SOUTHEAST HALF OF THE CWA OVER THE NEXT FEW HOURS.
GENERALLY QUICK DROP TO 1/4SM VIS WITH 0.5-1.0 INCH ACCUMULATIONS IN
20 MINUTES WITHIN THE HEAVIER SNOW SHOWERS. EXTRAPOLATION OF RADAR
LOOP INDICATES BAND SHOULD EXIT ALL BUT PERHAPS THE EXTREME
SOUTHEAST PART OF THE FORECAST AREA BY SUNRISE...WITH A FEW LIGHTER
SNOW SHOWERS ALSO ACROSS FAR NORTHEAST IL BENEATH PATH OF MID-LEVEL
VORT DURING THAT TIME. RELATIVELY DRY ARCTIC AIR SPREADING IN FROM
THE NORTHWEST WILL ALLOW SOME SCATTERING OF CLOUD COVER AND AN END
TO ACCUMULATING SNOW SHOWERS BY SUNRISE...THOUGH ONE MORE SHORT WAVE
DROPPING SOUTHEAST ACROSS MINNESOTA AT 08Z MAY BE ENOUGH TO PRODUCE
SOME ENHANCED STRATOCU AND A FEW FLURRIES ACROSS THE REGION DURING
THE MID/LATE MORNING HOURS. IN THE WAKE OF THE PASSAGE OF THIS
MID-LEVEL VORT AXIS AROUND MIDDAY...RISING HEIGHTS AND SUBSIDENCE
SHOULD RESULT IN AN END TO FLURRIES AND THINNING/EROSION OF THE
STRATOCU DECK ALLOWING PARTLY CLOUDY/MOSTLY SUNNY SKIES THIS
AFTERNOON. BLUSTERY NORTHWEST WINDS WILL KEEP TEMPS WELL BELOW
NORMAL ONCE AGAIN...WITH UPPER 20S/LOW 30S EXPECTED FOR AFTERNOON
HIGHS PER BIAS CORRECTED MOS BLEND. BROAD UPPER RIDGE BUILDS ACROSS
THE REGION TONIGHT IN THE WAKE OF OUR DEPARTING EASTERN CONUS UPPER
TROUGH WITH SURFACE HIGH PRESSURE RIDGE BUILDING INTO THE REGION
OVERNIGHT. THIS MORNINGS LIGHT SNOWFALL WILL BE GONE BY
TONIGHT...THOUGH LIGHT WINDS AND CLEAR SKIES WILL ALLOW FOR COOLING
INTO THE TEENS IN MOST AREAS BY WEDNESDAY MORNING.
SURFACE HIGH PRESSURE MOVES QUICKLY EAST OF THE FORECAST AREA
WEDNESDAY AS SURFACE PRESSURE FALLS DEVELOP ACROSS THE PLAINS AND
MISSISSIPPI VALLEY IN RESPONSE TO SURFACE LOW DEVELOPING OVER THE
DAKOTAS IN ADVANCE OF AN UPPER TROUGH OVER THE WESTERN CONUS AND
UPPER JET MAX SPREADING ACROSS THE CENTRAL AND SOUTHERN ROCKIES.
THIS RESULTS IN FAIRLY QUICK WARM ADVECTION AND MOISTURE TRANSPORT
INTO THE REGION ESPECIALLY ABOVE THE BOUNDARY LAYER AS 40-50 KT
SOUTH-SOUTHWESTERLY LOW LEVEL JET DEVELOPS BY LATE AFTERNOON.
INCREASING MID-LEVEL CLOUD COVER WILL LIKELY OFFSET SOME OF THE
WARMING AS WILL A SLIGHT SOUTHEAST COMPONENT TO THE BOUNDARY LAYER
WIND. EVEN SO...FAVOR WARMER MAV GUIDANCE OF WEDNESDAY AFTERNOON MAX
TEMPS IN THE UPPER 30S/LOWER 40S. EXCEPTION WILL BE ALONG THE
IMMEDIATE NORTH SHORE AREA...WHERE THAT SLIGHT SOUTHEAST WIND
COMPONENT MAY HOLD TEMPS IN THE MID 30S RIGHT ALONG THE LAKE. DEEPER
MOISTURE CONTINUES TO SPREAD INTO THE REGION WEDNESDAY NIGHT...AS
SURFACE LOW MOVES INTO THE UPPER MISSISSIPPI VALLEY AND A SHORT WAVE
TROUGH PROPAGATES FROM THE SOUTH CENTRAL PLAINS INTO THE WESTERN
GREAT LAKES. FORECAST SOUNDINGS DEPICT DEEP SATURATION OCCURRING
MAINLY AFTER MIDNIGHT...WITH SUFFICIENT FORCING APPROACHING SHORT
WAVE AND ISENTROPIC ASCENT/JET DIVERGENCE TO GO WITH LIKELY POPS.
THERMAL PROFILES BECOME NEARLY ISOTHERMAL NEAR 0C IN THE LOWER
LEVELS INITIALLY BEFORE WARM ADVECTION OVERWHELMS THE
COLUMN...SUGGESTING THE POTENTIAL FOR S BRIEF MIX OF RAIN/SNOW WITH
THE ONSET OF PRECIP...BUT QUICKLY TURNING TO RAIN AS 50-60 KT LOW
LEVEL JET CONTINUES TO PUMP IN WARM/MOIST AIR. TIGHT SFC PRESSURE
GRADIENT WILL MAINTAIN BREEZY SOUTH WINDS OVERNIGHT AS WELL...WHICH
WILL LIKELY KEEP TEMPS ABOVE FREEZING OVERNIGHT AND PROBABLY RISING
BEFORE SUNRISE. INITIAL SHORT WAVE LIFTS ACROSS THE AREA THURSDAY
MORNING...WITH AN AREA OF MODESTLY STEEP MID-LEVEL LAPSE RATES NOTED
ACROSS CENTRAL IL AND SOUTHERN CWA. HAVE INDICATED ISOLATED THUNDER
FAR SOUTH DURING THE MORNING PERIOD WITH THESE BETTER ELEVATED LAPSE
RATES BEFORE SOME MID-LEVEL DRYING OCCURS BEHIND THE INITIAL SHORT
WAVE. SHOWER CHANCES REMAIN RELATIVELY HIGH THROUGH THE DAY THURSDAY
IN MOIST WARM SECTOR...WITH GFS PRECIPITABLE WATER NEAR 0.9
INCHES...AND APPROACH OF SECOND SHORT WAVE/MAIN TROUGH AXIS LATER IN
THE DAY ALONG WITH APPROACH OF SURFACE COLD FRONT THURSDAY EVENING.
ECMWF REMAINS A LITTLE SLOWER WITH THE PASSAGE OF THE LOW/COLD FRONT
THURSDAY NIGHT...SO HAVE MAINTAINED POPS INTO THE NIGHT WITH A LOW
CHANCE LINGERING IN THE FAR EAST INTO EARLY FRIDAY. MILD/MOIST AIR
MASS SHOULD PUSH TEMPS UP AROUND 50 THURSDAY DESPITE CLOUDS/PRECIP.
COOLER AIR WORKS IN FRIDAY WITH WEAK HIGH PRESSURE RIDGE BEHIND
DEPARTING SYSTEM...WITH WINDS LIKELY TURNING NORTHEAST OFF THE LAKE
FRIDAY AFTERNOON KEEPING LAKESIDE LOCATIONS CHILLY AROUND 40 DEG.
GUIDANCE IN GOOD AGREEMENT IN BRINGING ANOTHER PROGRESSIVE AMPLIFIED
SHORT WAVE ACROSS THE AREA FRIDAY NIGHT/SATURDAY...WITH AN AREA OF
SURFACE LOW PRESSURE PASSING SOUTH OF THE CWA. MOST OF THE PRECIP
REMAINS SOUTH/SOUTHEAST OF THE FORECAST AREA WITH THIS FEATURE...
THOUGH HAVE INCLUDED LOW CHANCE POPS MAINLY FRIDAY NIGHT. PRECIP
TYPE COULD BE A QUESTION ESPECIALLY SOUTH WHERE IT COULD BE A
RAIN/SNOW MIX PER THICKNESS PROGS AND THERMAL PROFILES. NORTHEAST
WINDS AROUND THE NORTHERN PERIPHERY OF THE PASSING LOW WILL CONTINUE
TO HOLD TEMPS BELOW NORMAL...ESPECIALLY NEAR LAKE MICHIGAN. MODELS
CONTINUE TO DEVELOP ANOTHER DEEP LOW ACROSS THE NORTHERN PLAINS
SUNDAY/MONDAY...WITH STRONG SOUTH FLOW DEVELOPING AND OFFERING THE
PROSPECT OF WARMER WEATHER BY THE END OF THE FORECAST PERIOD.
BLENDED GUIDANCE INDICATES 55-60+ DEGREES SUNDAY AND MONDAY...THOUGH
WITH BREEZY CONDITIONS AND AN INCREASING POTENTIAL FOR RAIN MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* BRIEF BURST OF MODERATE TO POTENTIALLY VERY HEAVY SNOW AND WNW
GUSTS APPROACHING 30 KT. ARRIVING AT ORD 0630Z AND MDW 0700Z.
* GUSTY NORTHWEST WINDS RESUME THIS MORNING AND CONTINUE THROUGH
AFTERNOON.
RC
//DISCUSSION...UPDATED 06Z...
HAVE MOVED UP THE TIMING IN TAFS OF NARROW AND INTENSE LINE OF SN
ON LEADING EDGE OF SHARP COLD FRONT. IT IS SET TO ARRIVE AT DPA
SHORTLY AFTER 6Z...AROUND 630Z AT ORD...7Z AT MDW AND 730Z AT GYY.
WHEN LINE MOVED THROUGH RFD...THERE WAS ABOUT A 5-10 MINUTE PERIOD
OF 1/4 SM +SN ACCOMPANIED BY WNW GUSTS CLOSE TO 30 KT. WITH LINE
REMAINING WELL ORGANIZED WOULD EXPECT SIMILAR CONDITIONS AT THE
EASTERN TERMINALS. CONDITIONS WILL IMPROVE RAPIDLY 20-30 MIN AFTER
SNOW ONSET...THOUGH WILL NEED TO WATCH FOR A FEW SCT SHSN BEHIND
THE FRONT. WINDS WILL DIMINISH FOR A TIME OVERNIGHT BUT THEN RAMP
UP OUT OF THE NORTHWEST BY OR A FEW HOURS AFTER DAYBREAK.
EXPECTING GUSTS IN THE 25 TO 30 KT RANGE. FORECAST SOUNDINGS
SUPPORT BKN VFR CIG AROUND 4KFT THOUGH THERE COULD BE PERIODS OF
JUST SCT CLOUDS. SKIES WILL CLEAR AND WINDS WILL QUICKLY DIMINISH
AS HIGH PRESSURE MOVES OVERHEAD TUESDAY EVENING.
RC
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH IN BRIEF PERIOD OF MODERATE TO VERY HEAVY SNOW AND STRONG
WEST NORTHWEST WINDS.
* MEDIUM-HIGH IN CIG TRENDS TODAY.
* HIGH IN REMAINING ELEMENTS.
RC
//OUTLOOK FOR ORD/MDW FOR 12Z WEDNESDAY-12Z MONDAY...UPDATED 00Z...
WEDNESDAY...VFR.
THURSDAY...OCNL RA. IFR POSSIBLE.
FRIDAY...MVFR POSSIBLE EARLY...LIKELY TRENDING VFR.
SATURDAY AND SUNDAY...VFR.
IZZI
&&
.MARINE...
354 AM CDT
A FEW ACTIVE PERIODS COMING UP ON THE LAKE THROUGH THE END OF THE
WORK WEEK. NORTHWEST WINDS GUSTING TO 30 KT THROUGH LATE AFTERNOON
ON THE SOUTH HALF TODAY AND SMALL CRAFT CRITERIA WINDS...WITH WAVES
SUBSIDING DURING THE EVENING.
HIGH PRESSURE MOVING OVER THE LAKE TONIGHT THROUGH EARLY WEDNESDAY
WILL RESULT IN A BRIEF QUIET PERIOD. AS THE HIGH PRESSURE SLIDES
EAST ON WEDNESDAY...STRONG LOW PRESSURE WILL TAKE SHAPE ACROSS THE
CENTRAL PLAINS AND MOVE EAST. THIS WILL RESULT IN RAPIDLY INCREASING
SOUTHERLY WINDS LATE DAY WEDNESDAY THROUGH WEDNESDAY NIGHT. THE AIR
MASS WILL BE WARMING BUT STILL LOOKS TO BE MARGINALLY UNSTABLE
ENOUGH FOR A PERIOD OF GALES ON THE SOUTHERN AND CENTRAL PORTION OF
THE LAKE. HAVE NOT ISSUED A WATCH DUE TO LIMITED DURATION AND LOWER
CONFIDENCE IN PREVAILING OCCURRENCE OF GALES.
STRONG SOUTH-SOUTHWEST WINDS WILL CONTINUE THROUGH THURSDAY EVENING
AS THE LOW DRAWS NEARER. STABLE CONDITIONS WILL LIMIT
MIXING...THOUGH WINDS JUST ABOVE THE BOUNDARY LAYER COULD APPROACH
40 KT. SOME GUIDANCE CONTINUES TO KEEP MIXING ONGOING PART OF
THURSDAY ON THE NORTH HALF OF THE LAKE. HAVE OPTED TO CAP SPEEDS
BELOW GALES ON THURSDAY ACROSS THE LAKE DUE TO UNCERTAINTY WITH
MIXING. AFTER THE LOW CROSSES THE LAKE THURSDAY NIGHT...THE
TRAILING COLD FRONT WILL SWEEP ACROSS THE LAKE...WITH WINDS
SHIFTING NORTHWEST TO 25 TO 30 KT INTO FRIDAY BEFORE BACKING
NORTHERLY AND GRADUALLY DIMINISHING IN THE AFTERNOON. ANOTHER LOW
WILL TRACK ACROSS THE OHIO VALLEY EARLY SATURDAY AND IF IT GETS
CLOSE ENOUGH TO LAKE...NORTHEAST WINDS ON SOUTH HALF COULD BE
STRONGER THAN INDICATED. WINDS WILL TURN SOUTHERLY AND INCREASE ON
SUNDAY THROUGH SUNDAY NIGHT IN ADVANCE OF ANOTHER STRONG LOW
PRESSURE AREA THAT WILL MOVE ACROSS THE REGION ON MONDAY.
RC
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 PM TUESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 AM WEDNESDAY.
&&
$$
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
253 AM CDT Tue Mar 25 2014
.DISCUSSION...
ISSUED 253 AM CDT Tue Mar 25 2014
SHORT TERM...Today through Thursday
07z/2am radar imagery shows two bands of snow across central
Illinois...one along the I-55 corridor and one further west in the
Illinois River Valley. Based on radar timing tools and 05z HRRR,
snow will be east of I-57 by 12z, then will quickly exit into
Indiana by mid-morning. Will therefore hold on to low chance POPs
across the far E/SE KILX CWA through 15z, followed by dry
conditions across the board through the balance of the day. Sky
cover forecast will be a bit tricky today, as clearing immediately
behind the snow bands may be muddled by SCT-BKN clouds currently
upstream over Minnesota/northern Iowa. HRRR hints that this cloud
cover will filter southward into the area, resulting in a partly
sunny day. Main story will be the breezy and unseasonably cold
conditions. With temperatures hovering in the 30s and strong
northwesterly winds gusting to between 20 and 30mph, wind-chill
values will remain in the teens.
Clouds will clear out toward sunset as high pressure builds in
from the west. Thanks to clear skies and decreasing winds beneath
the ridge axis, a very cold night is in store with lows dipping
into the teens. High will quickly shift off to the east on
Wednesday allowing a warming trend to begin. Despite full
sunshine, will undercut numeric guidance by a couple of degrees
due to southeasterly component of return flow on back side of
departing high. Resulting high temperatures will remain in the
lower to middle 40s.
Models continue to markedly increase WAA Wednesday night, with all
solutions bringing rain showers into the area overnight. Think
this looks reasonable given strengthening low-level southerly flow
and moistening forecast soundings. In addition, precip coverage
will be enhanced by a lead short-wave ejecting northeastward out
of the Southern Plains. Have therefore bumped POPs to likely after
midnight. Thursday appears to be a windy and wet day, with
numeric guidance suggesting southerly winds gusting to around 30
mph. This will push highs well into the 50s. Increasing elevated
instability could lead to a few rumbles of thunder as well,
particularly as initial short-wave passes through the area. Main
convective event still looks likely for Thursday evening as cold
front pushes into central Illinois. Will continue with likely POPs
for showers and thunderstorms at that time.
LONG TERM...Friday through Monday
00z Mar 25 models are now in good agreement with timing of
departing front late Thursday night, resulting in a cooler and
drier day on Friday. Given model consensus, have removed shower
chances on Friday except across the far E during the morning.
Despite FROPA, a new fly-in-the-ointment has developed for the end
of the week. Both the GFS and ECMWF now develop a secondary
surface low along the trailing end of the front Friday night.
ECMWF had previously shown this feature on a few prior runs, but
never with any consistency. GFS on the other hand had always
advertised a clean FROPA with no secondary wave. GEM also shows
this wave, so given consensus among the three models, confidence
is growing that light precip may return to part of the area Friday
night. At this point, will focus low chance POPs across only the
southern CWA along/south of I-70 in closer proximity to the low
with dry conditions further north across the remainder of the
area. After that, upper heights rise considerably as ridge builds
across the central CONUS. As a result, temperatures will rise back
above normal, with readings climbing well into the 60s for Sunday
and Monday.
Barnes
&&
.AVIATION...
ISSUED 1154 PM CDT Mon Mar 24 2014
An initial band of light snow will reach PIA by 05z/midnight, then
progress eastward to CMI by 09z. A secondary band of snow about 1
to 2 hours behind the first band will produce snowfall rates of 1
inch per hour as it moves across the northern portions of C IL. The
dry air near the ground will limit snowfall amounts a bit. Most
areas will likely see up to a half inch on grassy areas with some
melting on the warmer road surfaces. The TAF sites will see MVFR
clouds and VIS at the onset of snow with potential for some IFR
vis and ceilings between the first and second band of snow. Tempos
were used to cover the potential for LIFR vis in heavier snows for
1/2sm sn for an hour or so at each site between 07z and 12z from
west to east. Snow should diminish quickly Tues morning as the
trough departs to the east and subsident motions become dominant.
A layer of VFR clouds are expected to redevelop before noon even
after snow comes to an end and linger into early evening before
clearing.
Winds will generally remain less than 10kt the rest of tonight,
with a variable wind direction until the W-NW winds increase later
tonight. By mid-morning on Tuesday, NW wind speeds will climb to
around 15G30kt as cold air advection intensifies. Those wind
speeds will likely linger until later afternoon before diminishing
to less than 10kt Tues evening.
Shimon
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1020 PM EDT WED MAR 26 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 270300Z IND TAF UPDATE/...
ISSUED AT 1020 PM EDT WED MAR 26 2014
NO CHANGES NEEDED TO THE TAF.
PREVIOUS DISCUSSION FOLLOWS...
GOOD CONFIDENCE IN VFR CONDITIONS EXPECTED UNTIL AFTER 00Z FRIDAY
WHEN MOISTURE INCREASES IN THE LOWER LEVELS PER MODEL TIME SECTIONS.
WOULD NOT RULE OUT THUNDERSTORMS THURSDAY AFTERNOON WITH BRIEF
MVFR...BUT MODELS KEEP EVEN WEAK ELEVATED INSTABILITY WEST OF THE
TAF SITES THROUGH 00Z FRIDAY.
WITH EXTREMELY DRY AIR IN PLACE...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 12Z AT IND.
WINDS SHOULD STAY UP NICELY TONIGHT NEAR 10 KNOTS FROM THE SOUTH AND
THEN INCREASE TO AROUND 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 MOVES IN THERE...BUT
WITH DIRECTION SHEAR 45 KNOTS OR LESS...WILL LEAVE IT OUT FOR NOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/CP
SHORT TERM...NIELD
LONG TERM....RYAN
AVIATION...MK
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
936 PM EDT WED MAR 26 2014
.UPDATE...
THE NEAR TERM 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 270000Z TAF ISSUANCE/...
ISSUED AT 615 PM EDT WED MAR 26 2014
GOOD CONFIDENCE IN VFR CONDITIONS EXPECTED UNTIL AFTER 00Z FRIDAY
WHEN MOISTURE INCREASES IN THE LOWER LEVELS PER MODEL TIME SECTIONS.
WOULD NOT RULE OUT THUNDERSTORMS THURSDAY AFTERNOON WITH BRIEF
MVFR...BUT MODELS KEEP EVEN WEAK ELEVATED INSTABILITY WEST OF THE
TAF SITES THROUGH 00Z FRIDAY.
WITH EXTREMELY DRY AIR IN PLACE...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 12Z AT IND.
WINDS SHOULD STAY UP NICELY TONIGHT NEAR 10 KNOTS FROM THE SOUTH AND
THEN INCREASE TO AROUND 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 MOVES IN THERE...BUT
WITH DIRECTION SHEAR 45 KNOTS OR LESS...WILL LEAVE IT OUT FOR NOW.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...NIELD
NEAR TERM...NIELD/CP
SHORT TERM...NIELD
LONG TERM....RYAN
AVIATION...MK
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AREA FORECAST DISCUSSION
NWS DES MOINES IA
957 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
WITHTHIS 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...27/00Z
ISSUED AT 648 PM CDT WED MAR 26 2014
VFR CONDITIONS ARE CURRENTLY IN PLACE ACROSS TAF SITES BUT CIGS
ARE EXPECTED TO LOWER WITH INCREASING PRECIP CHANCES AND CATEGORY
DEGRADATION INTO THE NIGHT...GOING MVFR TO IFR BY THU MORNING.
CURRENT KS/MO SHOWERS WILL LIKELY PRIMARILY AFFECT KOTM...BUT
ADDITIONAL SCT DEVELOPMENT IS ANTICIPATED OVERNIGHT INTO OTHER
SITES. DO NOT EXPECT CONTINUOUS PRECIP THROUGH THU...BUT LIKELY
MORE OFTEN THAN NOT SO HAVE INCLUDED IN THE FORECAST BODY FOR
AN EXTENDED PERIOD. POTENTIAL FOR THUNDER IS CERTAINLY THERE AS
WELL...BUT WILL HOLD OFF ON THAT MENTION UNTIL LOCATION AND TIMING
TRENDS BECOME BETTER DEFINED. WINDS WILL FLIP TO THE NW LATE IN
THE PERIOD AND MAY SWITCH KFOD PRECIP TYPE TO A MIX OR ALL SNOW
LATE. THESE TRENDS WILL EVENTUALLY AFFECT ALL SITES...BUT MAINLY
BEYOND THE VALID PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SMALL
SHORT TERM...LEE
LONG TERM...DONAVON
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1010 PM CDT Wed Mar 26 2014
...Update to synopsis...
.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 00Z TAFS through 00Z Thursday evening)
ISSUED AT 602 PM CDT WED MAR 26 2014
MVFR/IFR cigs will linger in the vicinity of KHYS, KDDC, and
possibly KGCK through late this evening as low level stratus
continues to slowly move northeast across central and eastern
portions of southwest Kansas. A few isolated thunderstorms may be
possible across extreme southwest Kansas through late this evening
possibly affecting KGCK. Otherwise, VFR conditions will return
west to east through early Thursday morning. As for winds, a
strong surface low across extreme northeastern Colorado and
northwest Kansas will shift slowly eastward tonight. As a result,
southerly winds of 25 to 35kt early this evening will gradually
become southwesterly overnight while decreasing below 25kt. Winds
will then become northwesterly 20 to 30kt mid to late morning
Thursday as a cold front pushes through western Kansas.
&&
.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...JJohnson
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
605 PM CDT Wed Mar 26 2014
...UPDATE TO AVIATION...
.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 00Z TAFS through 00Z Thursday evening)
ISSUED AT 602 PM CDT WED MAR 26 2014
MVFR/IFR cigs will linger in the vicinity of KHYS, KDDC, and
possibly KGCK through late this evening as low level stratus
continues to slowly move northeast across central and eastern
portions of southwest Kansas. A few isolated thunderstorms may be
possible across extreme southwest Kansas through late this evening
possibly affecting KGCK. Otherwise, VFR conditions will return
west to east through early Thursday morning. As for winds, a
strong surface low across extreme northeastern Colorado and
northwest Kansas will shift slowly eastward tonight. As a result,
southerly winds of 25 to 35kt early this evening will gradually
become southwesterly overnight while decreasing below 25kt. Winds
will then become northwesterly 20 to 30kt mid to late morning
Thursday as a cold front pushes through western Kansas.
&&
.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 46 67 35 61 / 20 10 10 10
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY until Midnight CDT tonight FOR KSZ030-031-044>046-
063>066-076>081-086>090.
&&
$$
SHORT TERM...Umscheid
LONG TERM...Gerard
AVIATION...JJohnson
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1106 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1106 AM MDT TUE MAR 25 2014
VFR CONDITIONS ARE EXPECTED FOR THE NEXT 24 HOURS. SOUTH WINDS
BEGIN TO STRENGTHEN THIS AFTERNOON AS A SURFACE LOW DEEPENS TO
THE WEST. DRY AIR SHOULD KEEP THE SKIES CLEAR OTHER THAN SOME
CIRRUS AND POSSIBLE DAYTIME CUMULUS THIS AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...RRH
AREA FORECAST DISCUSSION
NWS GOODLAND KS
541 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 538 AM MDT TUE MAR 25 2014
FOR KGLD...MVFR CEILINGS WILL BE IN PLACE THROUGH MID MORNING.
AFTER VFR CONDITIONS ARE EXPECTED THROUGH THE REST OF THE PERIOD.
SOUTHERLY WINDS WILL BE GUSTY IN THE AFTERNOON. AFTER CALMING DOWN
BRIEFLY AFTER DARK...THOSE SOUTH WINDS/LOW LEVEL JET WILL INCREASE
AGAIN BY LATE IN THE NIGHT WITH GUSTS EXPECTED. FOR KMCK...VFR
CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL BE VARIABLE
AND SHIFTING THROUGH THIS ENTIRE PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
416 AM MDT TUE MAR 25 2014
.SHORT TERM...(TODAY THROUGH THURSDAY NIGHT)
ISSUED AT 416 AM MDT TUE MAR 25 2014
FORECAST CONCERN WILL BE THE FORECAST FROM WEDNESDAY INTO THURSDAY
NIGHT. SATELLITE SHOWING AN AMPLIFIED AND BLOCKY PATTERN FROM THE
EASTERN PACIFIC INTO NORTH AMERICA. ANOTHER COLD FRONT IS PUSHING IN
FROM THE NORTH AT THIS TIME.
AT JET LEVEL...OVERLAND THE MODELS WERE FINE. HOWEVER THE JET THAT
WILL BE AFFECTING THE AREA BEGINNING TOMORROW IS WELL OUT OVER THE
OCEAN AND IS VERY HARD TO GET A HANDLE ON. SATELLITE OBSERVATIONS
FROM OUT THERE WOULD INDICATE THE MODELS HAVE A PROPER HANDLE ON IT
AT THIS TIME WITH MAYBE THE UKMET DOING THE BEST. AT MID LEVELS...
SATELLITE WOULD INDICATE THE NAM WAS DOING A LITTLE BETTER WITH THE
COMPLICATED UPPER LOW APPROACHING THE PACIFIC NORTHWEST AND
SOUTHWEST CANADA. OTHER FEATURE OF INTEREST IS THE UPPER LOW NEAR
THE BAJA. HERE AND WOULD ALSO SAY OVERALL THAT THE CANADIAN WAS DOING
A LITTLE BETTER THAN GFS AND UKMET. THE NAM AND RUC WERE DOING A
LITTLE BETTER THAN THE ECMWF ON THE SURFACE WIND/PRESSURE FIELD.
NAM/GFS WERE DOING A LITTLE BETTER THAN THE ECMWF/CANADIAN ON THE LOW
LEVEL THERMAL FIELD.
TODAY/TONIGHT...UPPER JET MOVES RAPIDLY EAST OF THE AREA DURING THE
DAY. CURRENTLY HAVE SOME WEAK RETURNS WITH A FEW STATIONS REPORTING
FLURRIES. RADAR TRENDS AND LATEST SMALL GUIDANCE SUPPORT THIS
ACTIVITY BEING DONE BY 12Z AND WILL NOT INCLUDE IN THE MORNING
FORECAST. THICK CLOUD COVER HAS OVERSPREAD THE AREA. THIS HAS CAUSE
THE TEMPERATURES TO WARM CONSIDERABLY ABOVE THE DEWPOINTS. FORECAST
SOUNDINGS AND SMALL SCALE GUIDANCE INDICATE THAT NO FOG IS GOING TO
DEVELOP SO WILL REMOVE THAT FROM THE MORNING GRIDS.
PRESSURE GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT HAVING
BREEZY TO PROBABLY WINDY CONDITIONS...ESPECIALLY IN THE WESTERN
PORTION THIS AFTERNOON. HOW FAST IT CLEARS OUT WILL DETERMINE THE
MAXES. BELIEVE SKIES WILL CLEAR FAIRLY QUICKLY. NEWEST GUIDANCE
WOULD SUPPORT GOING WARMER. RECENTLY GUIDANCE HAS SHOWN A COOL BIAS
AS WELL. FOR TONIGHT...TIGHT GRADIENT AND SOUTHERLY WINDS/WARM
ADVECTION TONIGHT WOULD SUPPORT MILD CONDITIONS OVER MOST OF THE
AREA...ESPECIALLY IN THE EASTERN PORTION. I STILL MAY BE TOO COOL.
WEDNESDAY/WEDNESDAY NIGHT...BELIEVE MOST OF THE MODEL OUTPUT HAS
DRYLINE/SURFACE TROUGH TOO FAR EAST CONSIDERING THE FLOW ALOFT. IN
THIS INSTANCE LIKE THE ECMWF AND ITS WIND DIRECTION AND DEWPOINTS
COMBINED WITH THE SPEEDS THE NAM IS SHOWING. THE 00Z ECMWF IS MUCH
FURTHER WEST THAN ANY OTHER GUIDANCE. 06Z NAM CAME IN AND PULLED
THE DRY LINE/SURFACE TROUGH BACK FURTHER WEST. ALSO NEW NAM
DEWPOINTS MATCH VERY CLOSE WHAT THE ECMWF WAS INDICATING. PRESSURE
GRADIENT AND 3 HOUR PRESSURE FALLS WOULD SUPPORT WINDY CONDITIONS IN
AT LEAST THE EASTERN THIRD TO HALF OF THE AREA THROUGH THE DAY.
SO IN REGARDS TO FIRE WEATHER. THE DRIEST AIR WILL BE WEST OF THE
COLORADO BORDER. ALSO THAT LOOKS TO BE WHERE THE WEAKEST WINDS WILL
BE AS WELL. STRONGEST WINDS ARE FURTHER SOUTH AND EAST. CONSIDERING
AT THIS TIME RELATIVE HUMIDITIES WILL REMAIN ABOVE 20 PERCENT FOR
MOST OF THE AFTERNOON AND THE WINDS WILL NOT BE THERE...WILL NOT BE
ISSUING A WATCH. THE DAY SHIFT WILL NEED TO TAKE ANOTHER LOOK.
BY LATE TOMORROW THE MODELS HAVE THE LEFT FRONT QUADRANT TO THE
SOUTHWEST OF THE AREA. DRY LINE/SURFACE TROUGH WILL BE NEAR TO A
LITTLE WEST OF THE COLORADO BORDER. EVEN THOUGH LOW LEVEL MOISTURE
RETURN IS STILL MODEST...ONLY INTO THE LOWER TO MIDDLE 40S AT BEST...
THE MODELS ARE IN MORE AGREEMENT IN REGARDS TO THE INSTABILITY THAT
WILL BE IN PLACE. CONSIDERING THAT THE SHORTWAVE TROUGH WILL NOT
ARRIVE UNTIL LATER IN THE AFTERNOON AND THE SURFACE CONVERGENCE IS
FURTHER WEST...DELAYED THE ONSET OF THE THUNDERSTORMS AND PULLED
THEM FURTHER WEST. THE CAVEAT TO ALL THIS IS THE PASSAGE OF A
SHORTWAVE TROUGH EARLIER IN THE DAY. THAT MAY MESS THINGS UP FOR
THIS ENTIRE PERIOD.
DURING THE NIGHT A RATHER STRONG LEFT FRONT QUADRANT LOOKS TO BE
AFFECTING THE SOUTHERN HALF OF THE AREA. STRONG 700 MB SHORTWAVE
TROUGH AND ASSOCIATED PV ANOMALY START MOVING IN LATER IN THE
EVENING INTO THE OVERNIGHT HOURS. THE LIFT AND MOISTURE FROM THE
NEWER MODEL RUN SUPPORTED WHAT THE DAY SHIFT HAD IN THERE AND LEFT
IT ALONE. WHAT ENDS UP HAPPENING IS GETTING PRECIPITATION AHEAD OF
THE FEATURE WITH WRAP AROUND OCCURRING LATER IN THE NIGHT. LOOKS
LIKE MOST OF THE PRECIPITATION WILL REMAIN RAIN WITH SOME MIXTURE
POSSIBLE IN THE WEST LATE IN THE NIGHT.
BREEZY TO WINDY CONDITIONS DEVELOP BEHIND THE FRONT AND DEPARTING
SYSTEM.
THURSDAY/THURSDAY NIGHT...MAIN JET IS TO THE EAST OF THE AREA.
BREEZY TO WINDY CONDITIONS WILL CONTINUE THROUGH THE MORNING.
MODELS SHOW A HUGE SPREAD IN THE LOW LEVEL THERMAL FIELD DURING THIS
ENTIRE PERIOD. DOES NOT LIKE THERE WILL BE A CHANCE TO WARM UP A
LOT. SO WENT MORE TOWARD THE COOLER BUT NOT COLDEST SOLUTIONS. AGAIN
LOOKS LIKE A MIXTURE POSSIBLE EARLY IN THE DAY WITH MAYBE A COMPLETE
SWITCH BACK TO RAIN. THIS ROUND OF PRECIPITATION LOOKS DONE BY 18Z.
ALL THIS PRETTY MATCHES WHAT THE DAY SHIFT END THERE AND MADE LITTLE
TO NO CHANGES.
MODELS LOOK TO BRING ANOTHER SHORTWAVE TROUGH AND ANOTHER BATCH OF
PRECIPITATION IN DURING THE NIGHT. THETA-E LAPSE RATES NEAR ZERO
WILL BE IN PLACE AS STRONG MESOSCALE FORCING PLUS A STRONG PV
ANOMALY MOVE THROUGH BEGINNING LATE IN THE EVENING INTO THE
OVERNIGHT HOURS. SO ADJUSTED THE GRIDS IN REGARDS TO THIS TIMING.
A COMPLETE CHANGEOVER TO SNOW DOES NOT HAPPEN UNTIL LATE IN THE FAR
WEST. HOWEVER...BY THE TIME IT GETS COLD ENOUGH THERE MAY BE MUCH
MOISTURE AND LIFT. REMAINDER OF THE AREA WILL SEE A RAIN OR
RAIN/SNOW MIX.
.LONG TERM...(FRIDAY THROUGH MONDAY)
ISSUED AT 416 AM MDT TUE MAR 25 2014
THE EXTENDED WILL BE CHARACTERIZED BY A SERIES OF SHORTWAVE TROUGHS
MOVING THROUGH THE CWA AND A RIDGE THAT WILL MOVE INTO THE CENTRAL
PLAINS THIS WEEKEND. THE FIRST THING TO NOTE IS THE PRECIPITATION ON
FRIDAY MORNING. FRONTOGENESIS WEAKENS AND THE AREAS OF STRONGEST
LIFT PUSH EAST FAIRLY QUICKLY AROUND 12Z ACCORDING TO THE NAM AND
GFS. THEREFORE...DECIDED TO HAVE SILENT POPS IN THE EASTERN HALF OF
THE CWA ON FRIDAY MORNING TO ACCOUNT FOR ANY REMAINING PRECIPITATION
THAT MAY LINGER SINCE CONFIDENCE IS NOT HIGH ENOUGH TO ASSIGN A
HIGHER VALUE AT THIS TIME.
THE REMAINDER OF THE EXTENDED WILL REMAIN DRY AS THE UPPER LEVEL
RIDGE MOVES INTO THE PLAINS ON SATURDAY. THE RIDGE BEING IN PLACE
WILL ALLOW TEMPERATURES TO WARM UP QUITE NICELY OVER THE WEEKEND
WITH HIGHS ON SATURDAY IN THE UPPER 60S TO LOW 70S AND HIGHS ON
SUNDAY IN MID TO UPPER 70S APPROACHING 80 DEGREES. WHILE GETTING
INTO THE DETAILS IN THE EXTENDED IS OFTEN DIFFICULT DUE TO MODEL
SPREAD AND OTHER VARIABLES...IT LOOKS LIKE SOUTHWEST SURFACE WINDS
COULD BE HIGH ENOUGH AND RH VALUES COULD BE LOW ENOUGH ON SUNDAY
AFTERNOON FOR ELEVATED FIRE WEATHER. HOWEVER...THIS IS STILL FAR
ENOUGH OUT THAT THIS COULD CHANGE.
SOME MODELS SHOW THE STRONGEST SHORTWAVE TROUGH AFFECTING THE CWA ON
SUNDAY NIGHT. THIS SHORTWAVE TROUGH WILL MOVE THROUGH THE NORTHERN
PLAINS AND DROP A COLD FRONT THROUGH THE CWA SUNDAY NIGHT. BEHIND
THE FRONT...NORTH WINDS WILL INCREASE AND COULD BECOME QUITE GUSTY.
HOWEVER...AS PREVIOUSLY MENTIONED...THESE KINDS OF DETAILS ARE HARD
TO PIN DOWN THIS FAR OUT. DEPENDING ON HOW THIS
DEVELOPS...PRECIPITATION COULD ALSO CHANGE. DECIDED TO GO AHEAD AND
KEEP THE REST OF THE EXTENDED DRY FOR NOW BECAUSE OF MODEL
DISCREPANCIES. THEREFORE...THE THINGS TO TAKE AWAY FROM THE EXTENDED
ARE THAT IT WILL BE DRY AFTER FRIDAY MORNING AND WARM OVER THE
WEEKEND WITH A SLIGHT COOL DOWN ON MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1048 PM MDT MON MAR 24 2014
VFR CONDITIONS FORECAST AT KGLD/KMCK THROUGH THE TAF PERIOD.
A BROKEN TO OVERCAST DECK OF MID CLOUDS WITH BASES FL060-100 WILL
PERSIST OVERNIGHT AT KMCK CONTINUING THRU 15Z TUESDAY. KGLD WILL
BE ON THE WESTERN FRINGE OF THIS DECK WITH BEST CIG POTENTIAL 08Z-
13Z. THIS CLOUD DECK WILL SLIDE OFF TO THE EAST TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL MOVE FROM MONTANA INTO SOUTHERN
NEBRASKA BY 15Z TUESDAY. SURFACE WINDS WILL BE LIGHT- VARIABLE
OVERNIGHT...GRADUALLY BECOMING S-SE TUESDAY MORNING WITH SPEEDS
INCREASING TO 12-15 KTS BY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...BULLER
LONG TERM...ALW
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1051 PM MDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 230 PM MDT MON MAR 24 2014
AS OF 2 P.M. MDT...VISIBLE SATELLITE IMAGERY INDICATED A DENSELY
POPULATED CUMULUS FIELD ACROSS THE TRI STATE AREA...WITH PARTLY TO
MOSTLY CLOUDY SKIES. NO SIGNIFICANT RADAR RETURNS WERE OBSERVED AS
DRY CONDITIONS WERE PRESENT ACROSS THE REGION.
UPPER LEVEL LONG WAVE TROUGH MOVES EASTWARD OUT OF THE CENTRAL
PLAINS AS STRONGER AREA OF THE JET MOVES DOWN THE HIGH PLAINS THIS
EVENING AND OVERNIGHT. HIGHER VORTICITY POCKET WILL HELP CREATE LIFT
TO GENERATE INCREASED CLOUD COVER FOR AREAS EAST OF HIGHWAY 83
TONIGHT. UPPER LEVEL TROUGH WILL MOVE INTO THE TRI STATE AREA FROM
THE WEST TO BRING CLEARING SKIES TO AREAS WEST OF HIGHWAY 83
OVERNIGHT.
LOW TEMPERATURES TONIGHT WILL STAY A BIT WARMER FOR AREAS EAST OF
HIGHWAY 83 WITH THE INCREASED CLOUD COVER...BUT TEMPERATURES WILL
REACH THE UPPER TEENS WITH THE AREAS OF CLEARING CLOUD COVER.
TEMPERATURES WILL DROP TO NEAR THE DEW POINTS WITH RELATIVE
HUMIDITIES AT THE SURFACE APPROACHING ONE HUNDRED PERCENT...WHICH
COULD CREATE SOME AREAS OF PATCHY FOG IN EASTERN COLORADO AND AREAS
WEST OF KANSAS HIGHWAY 27. RAP MODEL SOUNDINGS SHOW TEMPERATURES
WARMING IN THE MID MORNING...WHICH WILL BRING RAPID CLOUD CLEARING
WITH INCREASED SUBSIDENCE FROM THE SURFACE HIGH PRESSURE THAT MOVES
INTO THE HIGH PLAINS. AS SURFACE HIGH MOVES EASTWARD
TOMORROW...SOUTHERLY FLOW AND INCREASED WARM AIR ADVECTION WILL
ALLOW HIGH TEMPERATURES TO REACH THE LOW TO MID 50S. THE WARMEST
TEMPERATURES WILL BE ALONG THE KANSAS AND COLORADO STATE BOUNDARY AS
WARM FRONT WITH ASSOCIATED CYCLOGENESIS WILL BRING THE HIGHEST
TEMPERATURES. PROBABILITY FOR PRECIPITATION IS NEXT TO NONE TONIGHT
AND TOMORROW.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 251 PM MDT MON MAR 24 2014
TUESDAY NIGHT-THURSDAY...SHORT WAVE RIDGING EXPECTED TO BE DOMINANT
FORCING MECHANISM ACROSS THE FORECAST AREA DURING THE START OF THE
PERIOD...ALTHOUGH MORE ACTIVE WEATHER WILL DEVELOP ACROSS THE AREA
AS A SERIES OF PROGRESSIVE SHORT WAVE TROUGHS BEGINS TO INFLUENCE
THE AREA ON WEDNESDAY. INITIAL WEATHER CONCERNS WILL CENTER AROUND
POSITION OF WEAK DRY LINE EXPECTED TO BISECT THE AREA ON WEDNESDAY
AFTERNOON. TEMPERATURES WILL CLIMB INTO THE LOWER 70S TO THE WEST OF
IT...WITH AFTERNOON HUMIDITIES FALLING TO THE 15 PERCENT. THE
COMBINATION OF WARM TEMPS...DRY FUELS AND WESTERLY WINDS OF 15 TO 25
MPH WILL BRING THE POTENTIAL FOR CRITICAL FIRE WEATHER CONDITIONS.
WILL NEED TO WATCH FOR POTENTIAL WATCH OR WARNING AS THIS TIME
NEARS...BUT CURRENTLY IS A BIT TOO FAR OUT IN TIME TO WARRANT A
WATCH AT THIS POINT. TO THE EAST OF THE DRY LINE...STRONG SOUTHERLY
WINDS WILL NEAR ADVISORY LEVELS AS A NARROW AREA OF INSTABILITY
DEVELOPS ALONG IT. WILL LIKELY SEE A WEAK STORM OR TWO DEVELOP IN
THIS AREA...BUT WITH LIMITED INSTABILITY DO NOT EXPECT STRONG OR
WIDESPREAD STORMS ATTM. SHORT WAVE TROUGH...AS PER 1.5 PVU PRESSURE
ANOMALY...WILL BEGIN TO MOVE ACROSS THE AREA WEDNESDAY EVENING
BRINGING A PERIOD OF FORCED ASCENT...MAINLY TO THE NORTHERN CWA.
MODELS REALLY DIVERGE ON HOW THIS SYSTEM EVOLVES...RANGING FROM ONE
STRONG PERIOD OF FORCING TO SEVERAL INDIVIDUAL WAVES LINGERING
THROUGH THURSDAY. WITH LARGE DIFFERENCES BETWEEN OPERATIONAL MODELS
AND ENSEMBLE DATA FURTHER RAISING UNCERTAINTY...AM GOING TO KEEP
GENERAL FORECAST INTACT AND LIMIT POPS TO THE 30 TO 50 PERCENT RANGE.
IN THE EXTENDED (THURSDAY NIGHT-MONDAY)...WARMER AND DRIER WEATHER
WILL DEVELOP ACROSS THE AREA AS BROAD RIDGING BUILDS OVER THE AREA.
EXPECT TEMPERATURES TO WARM INTO THE UPPER 70S BY SUNDAY. ALTHOUGH
STANDARD DEVIATIONS OF THE ENSEMBLES REMAIN QUITE HIGH DURING THE
PERIOD...OVERALL MODEL AGREEMENT ON THE OVERALL PATTERN LEADS ME TO
LEAN TOWARDS WARMER SOLUTIONS. OVERALL QUIET WEATHER IS EXPECTED
ALTHOUGH FIRE DANGER WILL INCREASE AS THE TEMPS RISE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1048 PM MDT MON MAR 24 2014
VFR CONDITIONS FORECAST AT KGLD/KMCK THROUGH THE TAF PERIOD.
A BROKEN TO OVERCAST DECK OF MID CLOUDS WITH BASES FL060-100 WILL
PERSIST OVERNIGHT AT KMCK CONTINUING THRU 15Z TUESDAY. KGLD WILL
BE ON THE WESTERN FRINGE OF THIS DECK WITH BEST CIG POTENTIAL 08Z-
13Z. THIS CLOUD DECK WILL SLIDE OFF TO THE EAST TUESDAY MORNING.
SURFACE HIGH PRESSURE WILL MOVE FROM MONTANA INTO SOUTHERN
NEBRASKA BY 15Z TUESDAY. SURFACE WINDS WILL BE LIGHT- VARIABLE
OVERNIGHT...GRADUALLY BECOMING S-SE TUESDAY MORNING WITH SPEEDS
INCREASING TO 12-15 KTS BY AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...MK
LONG TERM...JRM
AVIATION...DLF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
927 PM CDT Wed Mar 26 2014
.UPDATE...
Issued at 927 PM CDT WED MAR 26 2014
The first of two primary shortwaves are dampening the western
limb of the departing ridge axis over the WFO PAH forecast area
this evening. A fairly efficient zone of isentropic lift in the 290 to
300 Kelvin layer is saturating parcels sufficiently to produce a
focused (northwest to southeast) oriented band of showers. As this
rain moves into a moist adiabatic lapse rate below the cloud
layer, the combination of precipitation loading and dry air
entrainment may yield a downward transport of wind to the surface.
These winds combined with an increasing pressure gradient
associated with deepening low pressure center in northwest Kansas
associated with the second shortwave will lead to some periodic
wind gusts between 25 and 35 mph this evening.
The GEM (Canadian) appears to be handling the initial MCV over
Kansas City and the associated baroclinic zone arcing across Missouri.
Main adjustments to the first period forecast package was to, 1) enhance
and overlay the current forecast PoP/Weather with the higher
resolution 3km HRRR guidance to focus on the trend of higher PoPs
in Missouri late this evening, shifting tot the Interstate 64
corridor in Illinois and Indiana late tonight, 2) make alterations
for the temperature and dewpoints toward the HRRR/LAMP guidance to
reflect higher wet bulbing with the approaching precipitation
shield, and 3) address winds overnight to reflect mixing behind
the precipitation.
UPDATE Issued at 448 PM CDT WED MAR 26 2014
Updated Aviation Section for 00Z TAF Issuance.
&&
.SHORT TERM...(Tonight through Friday night)
Issued at 305 PM CDT WED MAR 26 2014
A low pressure system will slide from the central Plains into the
Upper Mississippi valley tonight. Clouds will increase tonight across
the PAH forecast area as the associated warm front lifts northeast
across the area. Included slight to low chance pops across all but
our southeast counties by late tonight for showers. Pops will
decrease a bit Thursday morning with the warm front well north of
the area, then shower and thunderstorm chances will increase
Thursday afternoon into Thursday night across the entire region as
the associated cold front moves across the middle Mississippi and
lower Ohio valleys. Went with likely pops across all of our
counties Friday evening, then chance west to likely east after 06z
Friday. GFS, NAM, ECMWF and GEM all show the cold front hanging up
just southeast of the PAH forecast area by 12z Friday, and Friday
morning should be fairly dry except for maybe a few lingering
showers in the east.
By Friday afternoon and especially Friday night, precipitation
chances will quickly increase from southwest to northeast with
models showing an area of low pressure riding up the cold front.
All but the NAM take the low just southeast of the PAH forecast
area, while the NAM takes the low across west Kentucky. This leads
to the best instability being across west Kentucky into southeast
Missouri and extreme southern Illinois. Removed thunderstorm
chances for north and west portions of our counties. Models are
overall in good agreement showing a bit more substantial QPF with
this second round of showers and storms, in the half to three
quarter inch range.
.LONG TERM...(Saturday through Wednesday)
Issued at 305 PM CDT WED MAR 26 2014
On Sat, there may be some lingering rain showers mainly in the ern
half of the PAH forecast area very early in the day due to the
departing storm system. This feature will be quickly replaced by a
ridge aloft and dry/cool high pressure at the sfc. The air mass will
be of Pacific origin as opposed to Canadian. North winds Sat will
keep temps about 10 degrees below normal, but should rebound well
into the 60s by Sunday afternoon. Southerly flow developing ahead of
the next cold front will help generate even more warming Monday,
with many locations into the upper 60s. Shrtwv and sfc frontal
system appears moisture starved as they pass through Monday
night/Tue, due to a dry low level fetch out of the Gulf region.
Minimal QPF is forecast with showers, and a minor cool down behind
the system.
&&
.AVIATION...
Issued at 448 PM CDT WED MAR 26 2014
Mid clouds will spread across the TAF sites this evening, gradually
lowering to low VFR by tmrw morning. South winds will increase to
around 10 kts with higher gusts by 06z, and 15 to 25 kts with
gusts around 30 kts after 12z. Isolated showers are possible
between 06z and 12z, mainly at KCGI and KEVV, but chances are too
low to include in TAFs. No vsby restrictions expected.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...Smith
AREA FORECAST DISCUSSION
NWS PADUCAH KY
1147 PM CDT Mon Mar 24 2014
.UPDATE...
Issued at 919 PM CDT MON MAR 24 2014
Followed the HRRR and RUC13 and 18Z NAM, along with observational
trends for general PoP trends through Tuesday morning. A narrow
east-west oriented band of light snow extending from Farmington
Missouri to Evansville Indiana will gradually dry up from west to
east late this evening, as it drifts slowly southward.
Temperatures will drop close to freezing once this snow sets in,
so some minor accumulations will be possible in this area late
this evening. Other light precipitation may dive southeast through
western portions of southeast Missouri and possibly into the
Purchase Area of west Kentucky through the late evening. This
should mainly be rain, and temperatures will likely hold in the
middle 30s.
There should be a break for a few hours after midnight, before
another impulse rotates through the area with a band of light snow
or snow showers. More minor accumulations will be possible over
southern Illinois generally north of Highway 13, southwest
Indiana and northwest Kentucky. This will likely straddle sunrise
and may be ongoing during the morning commute over the Evansville
Tri State. Will have to monitor for slick conditions in the
morning...but confidence is low to think about an Advisory at this
time. All totalled, grassy accumulations will generally be a half
inch or less, with the greatest amounts over southwest Indiana.
The RUC has a real good handle on surface temperatures, as they
drop to near freezing once the precipitation develops in a given
area. Used it as a guide for trends through the night, but
ultimately, low temperatures were not impacted much by morning.
&&
.SHORT TERM...(Tonight through Wednesday)
Issued at 247 PM CDT MON MAR 24 2014
Main challenge this package is the threat for rain/snow mainly
tonight over the northern half.
Water vapor and radar indicate a weak system in the flow currently
over Kansas. All models continue to weaken the system as it moves
closer to us. We are very dry in the low levels so it may take a
while for the precipitation to reach the ground. It should
saturate over the north central areas by early evening. May be a
mix of rain/snow initially, but the column will be cold enough to
generate some snow for a few hours overnight.
Ground is warm and it does not look like we will exceed 1 inch per
hour rates, so feel that any accumulations will be confined to grassy
surfaces. Total QPF is less than a tenth of an inch and snowfall
is expected to be less than 1/2 inch.
This system will exit the area tomorrow morning, maybe with a few
lingering flurries in the northeast in the morning. After that,
high pressure will move into the area and we will remain dry
through Wednesday.
Will strongly word fire weather forecast for tomorrow as winds
will be strong and afternoon RH values will range from 30-40
percent.
Tuesday night will be coldest night of the week with lows in the
teens near I-64 and mid 20s in the south.
.LONG TERM...(Thursday through Monday)
Issued at 247 PM CDT MON MAR 24 2014
The med range models/ensembles seem in decent agreement with the
over synoptic pattern through Friday. Thereafter...12Z GFS diverges
from the operational ECMWF/GEM runs with respect to sfc low/precip
generation over the OH Valley. The GFS seems like an outlier here,
so will not give it too much weight at this time.
As far as the sensible weather is concerned, though shower chcs will
begin to slowly increase late Wed night in prefrontal warming
environment, the highest chc for showers and even some elevated
thunderstorms will come with the frontal passage Thu night. Some
locations may end up with a half inch or more. Decided to go with
a mainly rain free forecast once the front exits the area Friday
as high pressure presses southeast into the Midwest. Again, will
discount the 12Z GFS for now in the Fri/Fri night time frame. Will
also stick closer to the cooler EC MOS numbers Friday. Confidence
increases once again as we move into the weekend. There seems to
be very good model agreement that a dry and warming pattern should
get underway in the last few days of the extended period.
&&
.AVIATION...
Issued at 1146 PM CDT MON MAR 24 2014
Had to speed up the onset of snow across the TAF sites this
evening. With the exception of KPAH, kept all TAF`s in VFR ceiling
category, before clearing late Tuesday afternoon and evening.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...DRS
SHORT TERM...PS
LONG TERM...GM
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
430 PM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 423 PM EDT TUE MAR 25 2014
A LOW PRESSURE SYSTEM MOVING THROUGH THE GREAT LAKES REGION WILL
CONTROL THE FIRST PART OF THE LONG TERM FORECAST. THIS LOW...WHICH
WILL BE AROUND 989MB IN WESTERN NEBRASKA AT 00Z THURSDAY...WILL
SLIDE AN ELONGATED TROUGH NORTHEAST THROUGH NORTHWEST MINNESOTA AT
THE SAME TIME. THIS TROUGH WILL BE ASSOCIATED WITH THE FIRST WAVE
OF PRECIPITATION ASSOCIATED WITH THE SYSTEM. AS THIS TROUGH SLIDES
EAST ON WEDNESDAY NIGHT AND OVER FAR WESTERN LAKE SUPERIOR BY 12Z
THURSDAY...BROAD WARM AIR ADVECTION ON THE 850-600MB LEVELS AND
ISENTROPIC ASCENT ON THE THE 275-295K SFCS WILL SLIDE
EAST-NORTHEAST THROUGH THE CWA. WOULD EXPECT THE SNOW TO SLIDE INTO
THE NORTHERN HALF OF THE CWA DURING THE EVENING HOURS AND THEN GET
ADDITIONAL DEVELOPMENT OVER THE EAST DURING THE OVERNIGHT HOURS AS
THE WAA BECOMES MAXIMIZED/FOCUSED THERE. QPF IN THESE WAA EVENTS IS
ALWAYS TRICKY AND THE MODELS HAVE BEEN STRUGGLING ON THE EXACT
AMOUNTS/LOCATIONS...SO HAVE FOCUSED ON WHERE THE FORCING IS
MAXIMIZED WITH THE HIGHEST POPS/QPF. IN ADDITION FOR THE
EAST...THERE MAY BE ENOUGH LINGERING COLD AIR WITH THE SOUTHERLY
WINDS OFF THE PATCH OF OPEN WATER OVER NORTHWEST LAKE MICHIGAN TO
LEAD TO A LITTLE BIT OF ENHANCEMENT. OVERALL...HAVE SNOWFALL
AMOUNTS OF 0.5-2.5 INCHES FOR THE WEDNESDAY NIGHT PERIOD...WITH THE
LOWEST VALUES ALONG THE WI BORDER AND THE HIGHEST OVER THE KEWEENAW
AND LUCE COUNTIES. ONE ITEM OF NOTE IS THE MODELS ARE SHOWING THE
DEEP MOISTURE CUTTING OUT FROM THE SOUTH DURING THE OVERNIGHT HOURS.
THIS WOULD LEAD TO A TRANSITION TO A FREEZING RAIN/DRIZZLE SITUATION
UNTIL THE LOW LEVEL TEMPERATURES CAN WARM ON THURSDAY MORNING.
HEADING INTO THURSDAY...THE SURFACE TROUGH WILL SHIFT EAST ACROSS
THE CWA WHILE THE SURFACE LOW IS MOVING NORTHEAST INTO
SOUTHERN WISCONSIN BY THURSDAY EVENING. 12Z GFS REMAINS THE FASTEST
SOLUTION AND MOVING THE LOW NORTHEAST THROUGH NORTHWEST LOWER
MICHIGAN THURSDAY EVENING...WHILE THE NAM IS WAY TO THE NW. THE 12Z
GEM/ECMWF MEANWHILE ARE MUCH SLOWER AND TRACK THE LOW THROUGH THE
NORTHERN/CENTRAL OF LOWER MICHIGAN RESPECTIVELY LATE THURSDAY
NIGHT. WITH THE EXTREMELY WELL CLUSTERED 00Z ECMWF ENSEMBLE MEMBERS
ON THE LOW TRACK...HAVE A HARD TIME GOING MUCH AWAY FROM THAT IDEA
ALTHOUGH THE 12Z ECMWF WAS FARTHER SOUTHEAST. THUS...LIKE YESTERDAY
WILL FOLLOW THE SLOWER IDEA FOR TIMING AND THEN A BLEND OF THE
ECMWF/GFS/GEM FOR THE LOW TRACK.
AS FOR HOW THE PRECIPITATION WILL EVOLVE...EXPECT THERE TO BE SOME
WAA PRECIPITATION CONTINING INTO THE MORNING HOURS OVER THE EASTERN
CWA...BUT MODELS DO HINT AT THE DEEPER MOISTURE BEGINNING TO CUT
OUT OVER THE REST OF WESTERN/CENTRAL CWA AND WOULD EXPECT A
TRANSITION AWAY FROM SNOW AND TOWARDS A MIX OR RAIN/DRIZZLE. THAT
SIMILAR IDEA OF LIQUID PRECIP FOR THE MORNING SEEMS REASONABLE WITH
THE LACK OF DEEP MOISTURE AND MUCH OF THE CLOUD LAYER BELOW THE
FAVORED ICE CRYSTAL TEMPERATURES. SINCE THIS IDEA HAS BEEN SHOWN
OVER THE LAST DAY...TRANSITIONED THAT AREA TO MORE RAIN/DRIZZLE THAN
SNOW FOR THURSDAY MORNING. SURFACE TEMPERATURES WILL BE NEAR OR
SLIGHTLY BELOW FREEZING AT INITIALLY THURSDAY MORNING...SO THERE
COULD BE A FEW HOUR PERIOD OF FREEZING DRIZZLE...BUT WITH SOME
SNOW LIKELY OCCURRING EARLIER THE IMPACTS SHOULD BE LIMITED. FARTHER
WEST...WOULD EXPECT THERE TO BE A STRONG BAND OF PRECIPITATION
(MAINLY SNOW) ALONG THE WEST SIDE OF THE SURFACE TROUGH. THIS BAND
WILL BE OVER WESTERN LAKE SUPERIOR LATE WEDNESDAY NIGHT AND THEN
SHIFT EAST AND ONSHORE OVER THE FAR WEST ON THURSDAY MORNING. THIS
EASTWARD SHIFT WILL CONTINUE THROUGH THE AFTERNOON/EVENING HOURS
ACROSS THE REST OF THE CWA AND WOULD EXPECT SOME INTENSIFICATION OF
THE BAND DUE TO THE SHORTWAVE TROUGH EXPECTED TO PULL NORTHEAST WITH
THE SURFACE LOW AND INTO THE GREAT LAKES REGION. OUR CWA WILL BE ON
THE NORTHERN EDGE OF THAT WAVE...BUT THERE SHOULD STILL BE SOME
INFLUENCE. THEN AS THE LOW PULLS OUT OF LOWER MICHIGAN LATE THURSDAY
NIGHT AND FRIDAY MORNING...THE PRECIPITATION WILL FOLLOW SUIT AND
SHOULD BE MAINLY OUT OF THE CWA BY 12Z FRIDAY. THERE COULD BE SOME
LIGHT UPSLOPE SNOW UNDER THE NW WINDS ON FRIDAY OVER THE NW/NC U.P.
BUT WITH LITTLE HELP FROM LAKE ENHANCEMENT (MARGINAL 850MB TEMPS
AROUND -10C)...LITTLE OPEN WATER...AND DRY AIR MOVING IN FROM THE
APPROACHING HIGH WILL QUICKLY DIMINISH POPS FRIDAY MORNING.
NOW FOR PCPN AMOUNTS/TYPE. QPF AMOUNTS FOR THURSDAY INTO THURSDAY
NIGHT WILL LIKELY BE AROUND 0.33-0.66 (HEAVIEST EAST)...BUT THERE
COULD BE SOME LOCALIZED HIGHER AMOUNTS IN ANY BANDED LOCATIONS ALONG
THE SURFACE TROUGH. WITH DIFFERING IDEAS FROM THE MODELS ON HOW TO
HANDLE THE LOW-MID LEVEL WARMING...HAVE BEEN STRUGGLING WITH HOW
MUCH RAIN TO PUT IN THE FORECAST. GEM CONTINUES TO SHOW THE WARMEST
THERMAL PROFILE AND WOULD PUT RAIN OVER MUCH OF THE CWA. ECMWF/GFS
IN DECENT AGREEMENT THROUGH MUCH OF THURSDAY BEFORE THE FASTER GFS
QUICKLY PULLS COLD AIR INTO THE CWA. THE ECMWF SOLUTION WOULD KEEP
THE PRECIPITATION ASSOCIATED WITH THE FGEN/TROUGH AS MAINLY SNOW
AND THAT SEEMS REASONABLE WITH THE EXPECTED INTENSITY AS THAT
STRONGER BAND MOVES THROUGH. BEFORE THE TROUGH ARRIVES AND THE
EXPECTED LOSS OF DEEP MOISTURE...WILL HOLD ONTO SOME RAIN OVER
THE CENTRAL AND SHIFT IT EAST THROUGH THE DAY. OVER THE SOUTH
CENTRAL (MENOMINEE COUNTY)...THINK THEY WOULD HAVE BEST OPPORTUNITY
TO SEE AT LEAST HALF OF THE THURSDAY AFTERNOON PRECIP AS RAIN UNTIL
THE COLD AIR SURGES IN THURSDAY EVENING. THE P-TYPE MAKES THE
SNOWFALL FORECAST TRICKY...BUT THE GOING FORECAST HAS 1-4 INCHES
OVER MOST OF THE AREA AND SOME HIGHER AMOUNTS WHERE THE PRECIP WILL
BE ALL SNOW (KEWEENAW PENINSULA AND LUCE COUNTY). WILL CONTINUE TO
MENTION IN THE HWO...ALTHOUGH ADJUST THE WORDING TO HIGHLIGHT THE
FREEZING RAIN POTENTIAL LATE WEDNESDAY NIGHT INTO THURSDAY MORNING.
ALL IN ALL...IT APPEARS THAT IT WILL MAINLY BE AN ADVISORY TYPE
EVENT.
AS FOR THE REST OF THE FORECAST PERIOD...THE HIGH PRESSURE RIDGE
WILL LEAD TO CLEARING SKIES ON FRIDAY AFTERNOON/EVENING AND A QUIET
PERIOD OF WEATHER HEADING INTO SATURDAY. A TRANSITION TO MORE ZONAL
FLOW ON SATURDAY COULD SET THE STAGE FOR A BRIEF PERIOD OF PRECIP
ASSOCIATED WITH A SHORTWAVE MOVING EAST ALONG THE US/CANADIAN
BORDER ON SATURDAY NIGHT. BEST OPPORTUNITY WOULD BE OVER THE
NORTHERN HALF OF LAKE SUPERIOR AND WILL ONLY HAVE SLIGHT CHANCES
OVER THE NORTHERN PART OF THE CWA. WARM SOUTHWESTERLY FLOW AHEAD OF
A COLD FRONT THAT WILL MOVE THROUGH ON SUNDAY NIGHT WILL LEAD TO
NORMAL TO ABOVE NORMAL HIGHS ON SUNDAY. ECMWF/GEM CONTINUE TO
HANDLE HIGHS WELL THIS DAY (MID-UPPER 40S OVER THE WEST HALF OF
UPPER MICHIGAN)...WHILE THE GFS IS HEAVILY BIASED BY ITS SNOW COVER
KEEPING TEMPS DOWN. WILL CONTINUE TO FOCUS ON GEM/ECMWF TEMPS FOR
HIGHS.
AS THE COLD FRONT MOVES THROUGH ON SUNDAY NIGHT...SHOULD SEE SOME
PRECIPITATION ASSOCIATED WITH IT. THERMAL PROFILE WOULD SUPPORT
RAIN TRANSITIONING TO SNOW FROM WEST TO EAST THROUGH THE NIGHT AND
INTO MONDAY MORNING. MODELS DIFFER MORE ON THE EVOLUTION OF THE
UPPER TROUGH AND ASSOCIATED SURFACE LOW HEADING INTO MONDAY...WITH
THE 12Z ECMWF DIGGING IT MUCH FARTHER SOUTH (MID MISSISSIPPI
VALLEY) WHILE THE 12Z GFS HAS IT IN THE GREAT LAKES REGION. WILL
FOLLOW A GENERAL BLEND OF THE TWO FOR NOW. BEHIND THE WAVE...HIGH
PRESSURE WILL START TO MOVE IN ON TUESDAY AND TEMPERATURES WILL FALL
BACK TO BELOW NORMAL VALUES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS ANOTHER HIGH
PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING
IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE
THROUGH THE GREAT LAKES REGION LATE THURSDAY NIGHT AND FRIDAY.
AHEAD OF THE LOW...SRLY WINDS WILL INCREASE TO 20 TO 25 KNOTS.
THEN...EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF THE LOW
THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON INTO
SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
412 PM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL TROUGH FROM
SRN HUDSON BAY THROUGH THE CNTRL GREAT LAKES INTO THE SE CONUS AND A
RIDGE OVER THE ROCKIES RESULTING IN NW FLOW THROUGH THE NRN GREAT
LAKES. AT THE SFC...ACYC WNW WINDS PREVAILED THROUGH UPPER MICHIGAN
AHEAD OF A RIDGE BUILDING INTO THE UPPER MS VALLEY. IN THE COLD
AIRMASS WITH 850 MB TEMPS TO AROUND -23C...DIURNAL CLOUD AND
FLURRIES HAD DEVELOPED OVER MUCH OF THE REGION. HOWEVER...LITTLE OR
NO ACCUMULATION HAS OCCURRED SINCE EARLY AFTERNOON.
TONIGHT...WITH THE LOSS OF DAYTIME HEATING...EXPECT THE LIGHT SNOW
SHOWERS OR FLURRIES TO DIMINISH AND THE CLOUDS TO ALSO GRADUALLY
DISSIPATE. AS THE HIGH PRES RIDGE BUILDS INTO THE AREA AND WINDS
BECOME LIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS WILL DEVELOP.
WITH PWAT VALUES AOB 0.10 INCH...EXPECT TEMPS WILL DROP OFF TO
VALUES WELL BELOW GUIDANCE...ESPECIALLY AT THE TYPICAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR.
WEDNESDAY...WAA WILL DEVELOP AS THE PATTERN DEAMPLIFIES. DESPITE
SOME INCREASE IN MID/HIGH CLOUDS...THE COMBINATION OF SRLY FLOW AND
LIMITED SUNSHINE SHOULD BOOST TEMPS BACK INTO THE MID 20 TO AROUND
30. DURING THE AFTERNOON 285K-290K ISENTRROPIC LIFT MAY BE STRONG
ENOUGH TO PRODUCE SOME LIGHT SNOW. HOWEVER...WITH THE DRY LOWER
LEVELS...ONLY SLIGHT CHANCE POPS WERE MENTIONED LATE OVER THE WEST.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 PM EDT TUE MAR 25 2014
WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS ANOTHER HIGH
PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING
IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE
THROUGH THE GREAT LAKES REGION LATE THURSDAY NIGHT AND FRIDAY.
AHEAD OF THE LOW...SRLY WINDS WILL INCREASE TO 20 TO 25 KNOTS.
THEN...EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF THE LOW
THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON INTO
SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
154 PM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 153 PM EDT TUE MAR 25 2014
MAINLY DIURNAL SCT LIGHT SNOW SHOWERS AND FLURRIES WILL CONTINUE
THIS AFTERNOON AND DIMINISH BY EVENING. CIGS SHOULD REMAIN NEAR THE
MVFR THRESHOLD BUT GIVE WAY TO CLEARING THIS EVENING AS HIGH PRES
BUILDS INTO THE REGION AND WINDS BACK TO THE WSW. IMPROVEMENT MAY
BE SLOWER AT KCMX WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED
THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
118 PM EDT TUE MAR 25 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 322 AM EDT TUE MAR 25 2014
A NARROW BAND OF SNOW SHOWERS WILL CONTINUE TO PUSH THROUGH THE AREA
THROUGH THE EARLY HOURS THIS MORNING. THIS BAND OF SNOW SHOWERS IS
AT THE LEADING EDGE OF A REINFORCING SHOT OF ARCTIC AIR COMING IN
FROM THE NORTHWEST. SNOW SHOWERS WILL REMAIN LIKELY INTO THIS
AFTERNOON BEFORE THEY START TO DIMINISH AND MIGRATE CLOSER TO LAKE
MICHIGAN TONIGHT.
ANOTHER COLD DAY IS EXPECTED ON WEDNESDAY BEFORE A TREND OF MILDER
WEATHER CAN BE EXPECTED INTO LATER THIS WEEK. ANOTHER BATCH OF SNOW
WILL MOVE IN WEDNESDAY NIGHT BEFORE CHANGING TO RAIN ON THURSDAY AS
THE WARMER AIR MOVES IN. THIS RAIN COMBINED WITH SNOW MELT IS
EXPECTED TO INCREASE RIVER LEVELS ACROSS THE AREA. ANOTHER BATCH OF
COOLER AIR WILL COME IN FOR THE FRI AND SAT BEFORE MUCH WARMER
TEMPERATURES WILL BE POSSIBLE.
&&
.UPDATE...
ISSUED AT 1120 AM EDT TUE MAR 25 2014
STEEP LOW LEVEL LAPSE RATES... ENHANCED BY SMALL CLEAR SLOT BEHIND
THE DEPARTING COLD FRONT AND INCOMING H8 AIR AROUND -17C... WILL AID
IN THE DEVELOPMENT OF SOME FAIRLY INTENSE SNOW SHOWERS TODAY.
LAPS AND RAP FCST SOUNDINGS SHOW RELATIVELY DEEP MIXED LAYER UP TO
9000 FT AND EVEN SFC BASED CAPES OF 100-200 J/KG. THERE IS ANOTHER
PV ANOMALY SWINGING THROUGH THIS AFTERNOON TO AID IN LIFT. RADAR
LATE THIS MORNING HAS A VERY SPRINGLIKE LOOK WITH SMALL BUT
INTENSE OPEN CELLULAR CONVECTION.
HAVE UPDATED THE FCST TO REMOVE THE LIGHT INTENSITY QUALIFIER FOR
THE NUMEROUS SNOW SHOWERS THIS AFTERNOON AND TO FRESHEN WORDING AS
THE EARLIER SYNOPTIC EVENT HAS ENDED. ANY ADDITIONAL ACCUMULATIONS
THIS AFTERNOON WILL BE RELATIVELY MINOR SINCE THE HEAVIER SNOW
RATES WILL BE QUITE BRIEF IN DURATION... WITH SOME MELTING LIKELY
IN BETWEEN SNOW SHOW SHOWERS IN PEEKS OF LATE MARCH SUN.
ISSUED A SPECIAL WEATHER STATEMENT EARLIER TALKING ABOUT THE
HAZARD/IMPACT RELATED TO DRIVING INTO THESE POTENTIALLY SUDDENLY
BLINDING SNOW SQUALLS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
THE FIRST ORDER OF BUSINESS IN THE SHORT TERM PORTION OF THIS FCST
PACKAGE IS DEALING WITH THE ONGOING BAND OF SNOW MOVING THROUGH THIS
MORNING. WE WILL THEN HAVE TO IDENTIFY TRENDS WITH REGARDS TO LAKE
EFFECT THROUGH WED...BEFORE TURNING OUR ATTENTION TO THE NEXT SYSTEM
FOR WED NIGHT AND THU.
WE ARE SEEING THE NICE...YET SHORT BURST OF SNOW MOVING THROUGH THE
CWFA EARLY THIS MORNING ALMOST AS EXPECTED. THE ONE THING THAT IS A
LITTLE DIFFERENT THAN EXPECTED IS THE EAST/WEST BAND OF SNOW THAT IS
IN PLACE JUST NORTH OF THE CWFA ALONG M-55. THIS IS JUST A LITTLE
FURTHER NORTH THAN EXPECTED...WHICH SHOULD HELP CUT BACK ON SNOW
ACCUMS A LITTLE ACROSS THE NORTH.
OTHERWISE...THE BAND OF SNOW MOVING THROUGH SRN LOWER MICHIGAN IS
PROGRESSING TO THE EAST NICELY THIS MORNING. IT IS QUICK ENOUGH THAT
ACCUMULATIONS WILL BE LIMITED TO AN INCH OR SO...ALTHOUGH IT WILL
HAPPEN IN A SHORT PERIOD OF TIME. WE CONTINUE TO EXPECT THIS WILL
EXIT THE CWFA TO THE SE AROUND 12Z PER THE LATEST EXTRAPOLATION OF
THE BACK OF THE LINE. THE SHORT DURATION AND THE CORE OF THE SNOW
FALLING BEFORE THE MORNING COMMUTE CONTINUES TO JUSTIFY HOLDING OFF
ON AN ADVISORY AT THIS TIME.
WE EXPECT TO SEE A SHORT BREAK OF THE SNOW SHOWERS IN THE WAKE OF
THE LINE WITH THE COLD FRONT THIS MORNING. WE DO EXPECT SCATTERED TO
NUMEROUS SNOW SHOWERS TO DEVELOP BY MID-LATE MORNING WITH THE
ARRIVAL OF THE SUPPORTING UPPER TROUGH EXPECTED TO MOVE THROUGH
EARLY THIS AFTERNOON. THE TROUGH...COMBINED WITH DIURNAL
INSTABILITY...AND SOME CONTRIBUTION OF HEAT/MOISTURE FROM LAKE
MICHIGAN WILL JUSTIFY THE RELATIVELY HIGHER CHCS OF SNOW SHOWERS.
THE STRONG LATE MARCH SUN WILL LIMIT ANY ACCUMS...ALTHOUGH A QUICK
COVERING OF THE GROUND COULD OCCUR DUE TO THE CONVECTIVE NATURE OF
THE SNOW SHOWERS EXPECTED.
SNOW SHOWERS WILL START DIMINISHING DURING THE SECOND HALF OF THE
AFTERNOON AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA. WE
EXPECT THEM TO DIMINISH AT INLAND LOCATIONS...AND FOR THEM TO
MIGRATE CLOSER TO THE LAKE. THEY SHOULD GRADUALLY DIMINISH
ALTOGETHER BY WED MORNING AS HIGH PRESSURE MOVES DIRECTLY OVERHEAD.
WE DO EXPECT SKIES TO GO AT LEAST PARTLY CLOUDY IF NOT CLEAR
OVERNIGHT. THIS WILL ALLOW FOR A COLD NIGHT...ESPECIALLY INLAND.
THIS SHOULD CONTINUE INTO WED AS THE FLOW ALOFT BECOMES
ANTI-CYCLONIC.
WE WILL SEE PCPN CHCS INCREASE ONCE AGAIN DURING THE NIGHT TIME
HOURS ON WED NIGHT....ESPECIALLY ACROSS THE NW PORTION OF THE CWFA.
RETURN FLOW WILL SET UP ON THE BACKSIDE OF THE HIGH AT THE SFC...AND
GRADUALLY A DEEP SW FLOW ALOFT WILL SET UP OVER THE AREA BY THU
MORNING AS THE UPPER RIDGE AXIS SHIFTS EAST. SOME DECENT MOISTURE
TRANSPORT WILL TAKE PLACE...ALLOWING PCPN TO DEVELOP. THE PCPN WOULD
START OUT AS MAINLY SNOW. A WARM NOSE ALOFT TRIES TO PUSH IN
OVERNIGHT WHICH WOULD SUPPORT A LOW CHC OF SOME FREEZING RAIN. WE
WET BULB DOWN PRETTY WELL...AND P-TYPE BECOMES A MAINLY RAIN OR SNOW
SCENARIO BY THU MORNING WITH NEARLY AN ISOTHERMAL PROFILE DEVELOPING
BY 12Z THU. IT WILL CONTINUE TO WARM THU MORNING...AND ALL PCPN
SHOULD TURN TO RAIN BY 18Z THU. A BETTER THREAT OF PCPN/RAIN WILL
COME THU AFTERNOON /AND BEYOND/ AS THE NOSE OF THE LLJ/MOISTURE
TRANSPORT MOVES UP INTO THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
BETTER CONFIDENCE ON SOME RAIN FOR THURSDAY NIGHT. MODELS CONTINUE
TO SHOW LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN THURSDAY
NIGHT. THIS SYSTEM WILL CONTAIN GULF MOISTURE. THE NOSE OF THE 850
MB LOW LEVEL JET IS FORECASTED TO PUSH THROUGH THE REGION THU
EVENING. SO RAIN IS EXPECTED THU NIGHT...ESPECIALLY EARLY. POPS
WERE INCREASED. WHILE SOME OF THE RAIN COULD BE HEAVY....IT
APPEARS THAT SINCE THE LOW LEVEL JET STEADILY PUSHES THROUGH...THAT
THE DURATION OF ANY HEAVY RAIN WILL BE LIMITED. STILL WITH SNOW
MELT...ESPECIALLY NORTH OF GRAND RAPIDS...WE WILL NEED TO MONITOR
THE POTENTIAL FOR HYDRO IMPACTS. I DID TREND THE FORECAST MORE
TOWARDS RAIN FOR THU NIGHT. THE COLDER AIR ON THE HIGH RES EURO
ARRIVES AFTER 12Z FOR NORTHWEST COUNTIES. THE COLDER GFS SOUNDINGS
DO NOT SUPPORT SNOW GIVEN UNSATURATED DGZ ASSOCIATED WITH THE DRY
SLOT AFTER 06Z FRI.
WE WILL HAVE TO MONITOR THE NEXT WAVE OF LOW PRESSURE RIDING UP THE
OH VALLEY SAT. THIS WOULD BE A SNOW SYSTEM IF IT DID REACH SW LOWER
MI. LOOKS LIKE THE TRACK IS TOO FAR SOUTH AND EAST TO IMPACT THE
REGION.
IMPRESSIVE WARM AIR ADVECTION DEVELOPS SUNDAY NIGHT INTO MONDAY.
THIS SYSTEM WILL BE TAPPING GULF MOISTURE. OVERALL I BUMPED UP
TEMPS AND POPS OVER GUIDANCE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 118 PM EDT TUE MAR 25 2014
SCATTERED SNOW SHOWERS DOTTED THE LANDSCAPE EARLY THIS AFTERNOON.
BECAUSE OF THIS CONDITIONS WERE HIGHLY VARIABLE ACROSS THE REGION.
OUTSIDE OF THE SNOW SHOWERS VFR WEATHER CAN BE EXPECTED...BUT
WITHIN THE SNOW SHOWERS IFR OR EVEN BRIEFLY LIFR CAN BE EXPECTED.
THESE SHOWERS WERE LARGELY DIURNALLY DRIVEN AND WILL FALL APART
TOWARD EVENING...SO EXPECT MOST OF THE IFR WILL EXIT THE AREA
AROUND 01Z. HOWEVER MVFR CEILINGS SHOULD PERSIST OVERNIGHT...
IMPROVING TO VFR WED MORNING.
NW WINDS WILL REMAIN BRISK...GUSTING TO 20 TO 25 KNOTS...BUT THESE
WINDS WILL DROP OFF AROUND SUNSET AND REMAIN LIGHT INTO WED.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT MON MAR 24 2014
HAVE CANCELLED THE FLOOD WARNING FOR THE MAPLE RIVER AT MAPLE
RAPIDS. CURRENTLY 11 FLOOD ADVISORIES REMAIN. LIMITED SNOW MELT AND
LIMITED ADDITIONAL PRECIPITATION SHOULD ALLOW STEADY OR FALLING
LEVELS ACROSS THE AREA THROUGH WEDNESDAY.
CONFIDENCE IS GROWING THAT A SIGNIFICANT SHIFT TO MUCH WARMER AND
WETTER CONDITIONS WILL COMMENCE THURSDAY AND LAST WELL INTO NEXT
WEEK. SOME LONG RANGE COMPUTER MODELS PREDICT THAT LONG TERM
PRECIPITATION TOTALS OF A COUPLE INCHES OR MORE ARE POSSIBLE BY THE
END OF NEXT WORK WEEK. AT THE SAME TIME...HIGH TEMPERATURES NEXT
WORK WEEK COULD REMAIN WELL IN THE 50S.
FOR AREAS ALONG AND NORTH OF THE MUSKEGON RIVER BASIN...SNOW PACK IS
SIGNIFICANTLY GREATER WITH SNOW WATER EQUIVALENT OF 3 INCHES OR MORE
OVER A LARGE AREA. THIS COMBINED WITH THE EXPECTED CHANGE IN THE
WEATHER WOULD MEAN SIGNIFICANT RISES TO AREA RIVERS. THIS COULD BE
EXACERBATED FURTHER IF ICE JAMS DEVELOP. THE COOPERATIVE OBSERVER IN
SCOTTVILLE REPORTED THAT THE PERE MARQUETTE RIVER HAS ALREADY BEEN
OPEN SINCE LAST WEEK. HOWEVER...ICE WAS STILL PRESENT FARTHER
NORTH NEAR LUDINGTON AND IN PERE MARQUETTE LAKE. WE ARE WAITING TO
HEAR BACK FROM OTHER OBSERVERS ABOUT THE EXTENT OF ICE COVERAGE ON
THE MUSKEGON AND CHIPPEWA RIVERS.
FOR THE GRAND AND KALAMAZOO RIVER BASINS...THERE IS FAR LESS
SNOWPACK AND RIVERS ARE ESSENTIALLY ICE FREE. HOWEVER...IT IS
POSSIBLE THAT SIGNIFICANTLY MORE RAIN COULD FALL OVER THIS AREA WITH
THE PATTERN CHANGE...SO ALL RIVERS ACROSS SOUTHWEST LOWER MICHIGAN
WILL NEED TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...JK
HYDROLOGY...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1120 AM EDT TUE MAR 25 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 322 AM EDT TUE MAR 25 2014
A NARROW BAND OF SNOW SHOWERS WILL CONTINUE TO PUSH THROUGH THE AREA
THROUGH THE EARLY HOURS THIS MORNING. THIS BAND OF SNOW SHOWERS IS
AT THE LEADING EDGE OF A REINFORCING SHOT OF ARCTIC AIR COMING IN
FROM THE NORTHWEST. SNOW SHOWERS WILL REMAIN LIKELY INTO THIS
AFTERNOON BEFORE THEY START TO DIMINISH AND MIGRATE CLOSER TO LAKE
MICHIGAN TONIGHT.
ANOTHER COLD DAY IS EXPECTED ON WEDNESDAY BEFORE A TREND OF MILDER
WEATHER CAN BE EXPECTED INTO LATER THIS WEEK. ANOTHER BATCH OF SNOW
WILL MOVE IN WEDNESDAY NIGHT BEFORE CHANGING TO RAIN ON THURSDAY AS
THE WARMER AIR MOVES IN. THIS RAIN COMBINED WITH SNOWMELT IS
EXPECTED TO INCREASE RIVER LEVELS ACROSS THE AREA. ANOTHER BATCH OF
COOLER AIR WILL COME IN FOR THE FRI AND SAT BEFORE MUCH WARMER
TEMPERATURES WILL BE POSSIBLE.
&&
.UPDATE...
ISSUED AT 1120 AM EDT TUE MAR 25 2014
STEEP LOW LEVEL LAPSE RATES... ENHANCED BY SMALL CLEAR SLOT BEHIND
THE DEPARTING COLD FRONT AND INCOMING H8 AIR AROUND -17C... WILL AID
IN THE DEVELOPMENT OF SOME FAIRLY INTENSE SNOW SHOWERS TODAY.
LAPS AND RAP FCST SOUNDINGS SHOW RELATIVELY DEEP MIXED LAYER UP TO
9000 FT AND EVEN SFC BASED CAPES OF 100-200 J/KG. THERE IS ANOTHER
PV ANOMALY SWINGING THROUGH THIS AFTERNOON TO AID IN LIFT. RADAR
LATE THIS MORNING HAS A VERY SPRINGLIKE LOOK WITH SMALL BUT
INTENSE OPEN CELLULAR CONVECTION.
HAVE UPDATED THE FCST TO REMOVE THE LIGHT INTENSITY QUALIFIER FOR
THE NUMEROUS SNOW SHOWERS THIS AFTERNOON AND TO FRESHEN WORDING AS
THE EARLIER SYNOPTIC EVENT HAS ENDED. ANY ADDITIONAL ACCUMULATIONS
THIS AFTERNOON WILL BE RELATIVELY MINOR SINCE THE HEAVIER SNOW
RATES WILL BE QUITE BRIEF IN DURATION... WITH SOME MELTING LIKELY
IN BETWEEN SNOW SHOW SHOWERS IN PEEKS OF LATE MARCH SUN.
ISSUED A SPECIAL WEATHER STATEMENT EARLIER TALKING ABOUT THE
HAZARD/IMPACT RELATED TO DRIVING INTO THESE POTENTIALLY SUDDENLY
BLINDING SNOW SQUALLS.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
THE FIRST ORDER OF BUSINESS IN THE SHORT TERM PORTION OF THIS FCST
PACKAGE IS DEALING WITH THE ONGOING BAND OF SNOW MOVING THROUGH THIS
MORNING. WE WILL THEN HAVE TO IDENTIFY TRENDS WITH REGARDS TO LAKE
EFFECT THROUGH WED...BEFORE TURNING OUR ATTENTION TO THE NEXT SYSTEM
FOR WED NIGHT AND THU.
WE ARE SEEING THE NICE...YET SHORT BURST OF SNOW MOVING THROUGH THE
CWFA EARLY THIS MORNING ALMOST AS EXPECTED. THE ONE THING THAT IS A
LITTLE DIFFERENT THAN EXPECTED IS THE EAST/WEST BAND OF SNOW THAT IS
IN PLACE JUST NORTH OF THE CWFA ALONG M-55. THIS IS JUST A LITTLE
FURTHER NORTH THAN EXPECTED...WHICH SHOULD HELP CUT BACK ON SNOW
ACCUMS A LITTLE ACROSS THE NORTH.
OTHERWISE...THE BAND OF SNOW MOVING THROUGH SRN LOWER MICHIGAN IS
PROGRESSING TO THE EAST NICELY THIS MORNING. IT IS QUICK ENOUGH THAT
ACCUMULATIONS WILL BE LIMITED TO AN INCH OR SO...ALTHOUGH IT WILL
HAPPEN IN A SHORT PERIOD OF TIME. WE CONTINUE TO EXPECT THIS WILL
EXIT THE CWFA TO THE SE AROUND 12Z PER THE LATEST EXTRAPOLATION OF
THE BACK OF THE LINE. THE SHORT DURATION AND THE CORE OF THE SNOW
FALLING BEFORE THE MORNING COMMUTE CONTINUES TO JUSTIFY HOLDING OFF
ON AN ADVISORY AT THIS TIME.
WE EXPECT TO SEE A SHORT BREAK OF THE SNOW SHOWERS IN THE WAKE OF
THE LINE WITH THE COLD FRONT THIS MORNING. WE DO EXPECT SCATTERED TO
NUMEROUS SNOW SHOWERS TO DEVELOP BY MID-LATE MORNING WITH THE
ARRIVAL OF THE SUPPORTING UPPER TROUGH EXPECTED TO MOVE THROUGH
EARLY THIS AFTERNOON. THE TROUGH...COMBINED WITH DIURNAL
INSTABILITY...AND SOME CONTRIBUTION OF HEAT/MOISTURE FROM LAKE
MICHIGAN WILL JUSTIFY THE RELATIVELY HIGHER CHCS OF SNOW SHOWERS.
THE STRONG LATE MARCH SUN WILL LIMIT ANY ACCUMS...ALTHOUGH A QUICK
COVERING OF THE GROUND COULD OCCUR DUE TO THE CONVECTIVE NATURE OF
THE SNOW SHOWERS EXPECTED.
SNOW SHOWERS WILL START DIMINISHING DURING THE SECOND HALF OF THE
AFTERNOON AS THE UPPER TROUGH AXIS SHIFTS EAST OF THE AREA. WE
EXPECT THEM TO DIMINISH AT INLAND LOCATIONS...AND FOR THEM TO
MIGRATE CLOSER TO THE LAKE. THEY SHOULD GRADUALLY DIMINISH
ALTOGETHER BY WED MORNING AS HIGH PRESSURE MOVES DIRECTLY OVERHEAD.
WE DO EXPECT SKIES TO GO AT LEAST PARTLY CLOUDY IF NOT CLEAR
OVERNIGHT. THIS WILL ALLOW FOR A COLD NIGHT...ESPECIALLY INLAND.
THIS SHOULD CONTINUE INTO WED AS THE FLOW ALOFT BECOMES
ANTI-CYCLONIC.
WE WILL SEE PCPN CHCS INCREASE ONCE AGAIN DURING THE NIGHT TIME
HOURS ON WED NIGHT....ESPECIALLY ACROSS THE NW PORTION OF THE CWFA.
RETURN FLOW WILL SET UP ON THE BACKSIDE OF THE HIGH AT THE SFC...AND
GRADUALLY A DEEP SW FLOW ALOFT WILL SET UP OVER THE AREA BY THU
MORNING AS THE UPPER RIDGE AXIS SHIFTS EAST. SOME DECENT MOISTURE
TRANSPORT WILL TAKE PLACE...ALLOWING PCPN TO DEVELOP. THE PCPN WOULD
START OUT AS MAINLY SNOW. A WARM NOSE ALOFT TRIES TO PUSH IN
OVERNIGHT WHICH WOULD SUPPORT A LOW CHC OF SOME FREEZING RAIN. WE
WET BULB DOWN PRETTY WELL...AND P-TYPE BECOMES A MAINLY RAIN OR SNOW
SCENARIO BY THU MORNING WITH NEARLY AN ISOTHERMAL PROFILE DEVELOPING
BY 12Z THU. IT WILL CONTINUE TO WARM THU MORNING...AND ALL PCPN
SHOULD TURN TO RAIN BY 18Z THU. A BETTER THREAT OF PCPN/RAIN WILL
COME THU AFTERNOON /AND BEYOND/ AS THE NOSE OF THE LLJ/MOISTURE
TRANSPORT MOVES UP INTO THE AREA.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 322 AM EDT TUE MAR 25 2014
BETTER CONFIDENCE ON SOME RAIN FOR THURSDAY NIGHT. MODELS CONTINUE
TO SHOW LOW PRESSURE TRACKING THROUGH LOWER MICHIGAN THURSDAY
NIGHT. THIS SYSTEM WILL CONTAIN GULF MOISTURE. THE NOSE OF THE 850
MB LOW LEVEL JET IS FORECASTED TO PUSH THROUGH THE REGION THU
EVENING. SO RAIN IS EXPECTED THU NIGHT...ESPECIALLY EARLY. POPS
WERE INCREASED. WHILE SOME OF THE RAIN COULD BE HEAVY....IT
APPEARS THAT SINCE THE LOW LEVEL JET STEADILY PUSHES THROUGH...THAT
THE DURATION OF ANY HEAVY RAIN WILL BE LIMITED. STILL WITH SNOW
MELT...ESPECIALLY NORTH OF GRAND RAPIDS...WE WILL NEED TO MONITOR
THE POTENTIAL FOR HYDRO IMPACTS. I DID TREND THE FORECAST MORE
TOWARDS RAIN FOR THU NIGHT. THE COLDER AIR ON THE HIGH RES EURO
ARRIVES AFTER 12Z FOR NORTHWEST COUNTIES. THE COLDER GFS SOUNDINGS
DO NOT SUPPORT SNOW GIVEN UNSATURATED DGZ ASSOCIATED WITH THE DRY
SLOT AFTER 06Z FRI.
WE WILL HAVE TO MONITOR THE NEXT WAVE OF LOW PRESSURE RIDING UP THE
OH VALLEY SAT. THIS WOULD BE A SNOW SYSTEM IF IT DID REACH SW LOWER
MI. LOOKS LIKE THE TRACK IS TOO FAR SOUTH AND EAST TO IMPACT THE
REGION.
IMPRESSIVE WARM AIR ADVECTION DEVELOPS SUNDAY NIGHT INTO MONDAY.
THIS SYSTEM WILL BE TAPPING GULF MOISTURE. OVERALL I BUMPED UP
TEMPS AND POPS OVER GUIDANCE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 727 AM EDT TUE MAR 25 2014
SNOW SHOWERS MAY PERSIST INTO TONIGHT AS THE CLOUD DEPTH WILL
SUPPORT THIS...WHICH COULD LEAD TO BRIEF IMPACTS. SO WILL KEEP
THEM IN THE FORECAST. RECENT RADAR TRENDS DOES SHOW SOME
DEVELOPING SNOW SHOWERS NORTH OF GRAND RAPIDS. THESE COULD CLIP
KLAN WITH IFR CONDITIONS. ADDITIONAL SNOW SHOWERS DEVELOPING
AROUND KBIV COULD ARRIVE AT KAZO IN THE NEXT HR OR TWO. WIND WILL
LIKELY INCREASE THIS MORNING AND PERSIST THIS AFTERNOON...HOWEVER
MOST GUSTS SHOULD STAY UNDER 25 KNOTS.
&&
.HYDROLOGY...
ISSUED AT 330 PM EDT MON MAR 24 2014
HAVE CANCELLED THE FLOOD WARNING FOR THE MAPLE RIVER AT MAPLE
RAPIDS. CURRENTLY 11 FLOOD ADVISORIES REMAIN. LIMITED SNOWMELT AND
LIMITED ADDITIONAL PRECIPITATION SHOULD ALLOW STEADY OR FALLING
LEVELS ACROSS THE AREA THROUGH WEDNESDAY.
CONFIDENCE IS GROWING THAT A SIGNIFICANT SHIFT TO MUCH WARMER AND
WETTER CONDITIONS WILL COMMENCE THURSDAY AND LAST WELL INTO NEXT
WEEK. SOME LONG RANGE COMPUTER MODELS PREDICT THAT LONG TERM
PRECIPITATION TOTALS OF A COUPLE INCHES OR MORE ARE POSSIBLE BY THE
END OF NEXT WORK WEEK. AT THE SAME TIME...HIGH TEMPERATURES NEXT
WORK WEEK COULD REMAIN WELL IN THE 50S.
FOR AREAS ALONG AND NORTH OF THE MUSKEGON RIVER BASIN...SNOW PACK IS
SIGNIFICANTLY GREATER WITH SNOW WATER EQUIVALENT OF 3 INCHES OR MORE
OVER A LARGE AREA. THIS COMBINED WITH THE EXPECTED CHANGE IN THE
WEATHER WOULD MEAN SIGNIFICANT RISES TO AREA RIVERS. THIS COULD BE
EXACERBATED FURTHER IF ICE JAMS DEVELOP. THE COOPERATIVE OBSERVER IN
SCOTTVILLE REPORTED THAT THE PERE MARQUETTE RIVER HAS ALREADY BEEN
OPEN SINCE LAST WEEK. HOWEVER...ICE WAS STILL PRESENT FARTHER
NORTH NEAR LUDINGTON AND IN PERE MARQUETTE LAKE. WE ARE WAITING TO
HEAR BACK FROM OTHER OBSERVERS ABOUT THE EXTENT OF ICE COVERAGE ON
THE MUSKEGON AND CHIPPEWA RIVERS.
FOR THE GRAND AND KALAMAZOO RIVER BASINS...THERE IS FAR LESS
SNOWPACK AND RIVERS ARE ESSENTIALLY ICE FREE. HOWEVER...IT IS
POSSIBLE THAT SIGNIFICANTLY MORE RAIN COULD FALL OVER THIS AREA WITH
THE PATTERN CHANGE...SO ALL RIVERS ACROSS SOUTHWEST LOWER MICHIGAN
WILL NEED TO BE MONITORED CLOSELY OVER THE NEXT SEVERAL DAYS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...NONE.
&&
$$
UPDATE...MEADE
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MJS
AVIATION...MJS
HYDROLOGY...TJT
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
729 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 717 AM EDT TUE MAR 25 2014
SCT LAKE EFFECT -SHSN IN THE WAKE OF AN ARCTIC FRONT WILL CONTINUE TO
PRODUCE MVFR TO OCCASIONAL IFR CONDITIONS ACROSS THE TAF SITES THIS
MORNING. MVFR CIGS AND OCCASIONAL FLURRIES WILL PERSIST INTO THE
AFTERNOON HRS IN A NW FLOW...BUT THEN LOOK CONDITIONS TO IMPROVE TO
VFR TONIGHT AS WINDS BACK WSW. IMPROVEMENT WILL BE SLOWER AT KCMX
WITH UPSLOPE/ONSHORE WRLY FLOW INITIALLY EXPECTED THIS EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 522 AM EDT TUE MAR 25 2014
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S. WILL CONTINUE TO MINIMIZE THE USE OF THE NAM PAST 18Z THURSDAY
AS IT STILL IS AN OUTLIER WITH REGARDS TO THE STRENGTHENING OF THE N
EXTENT OF THE LOW AND IS QUICKEST TO SHIFT IT TO E QUEBEC THURSDAY
EVENING. WHILE THE 18Z GFS LINED UP BETTER WITH THE NEW 00Z RUN OF
THE ECMWF...THE 00Z GFS CONTINUED WITH THE QUICKER SOLUTION AGAIN.
THE CONSENSUS IS TO HAVE THE LOW SITUATED OVER THE CENTRAL PLAINS AT
06Z THURSDAY...WITH THE INVERTED TROUGH STRETCHING UP THROUGH N MN
AND W LAKE SUPERIOR. THE WEAKENING LOW WILL THEN MOVE ACROSS IA AND
S WI BY 00Z FRIDAY...BEFORE CROSSING LOWER MI OVERNIGHT. AS NOTED
ABOVE THE GFS HITS THE GAS ON THIS ONE...MOVING E OF LAKE HURON BY
12Z FRIDAY...WHILE THE ECMWF IS OVER S LOWER MI AND CENTRAL LAKE
HURON.
WHILE EXPECTED TO BE ALL SNOW THROUGH 12Z THURSDAY...THE POTENTIAL
EXISTS FOR SOME MIXING IN OF RAIN OR SLEET ALONG THE WI BORDER. THE
FOCUS FOR HEAVY WET SNOW WILL BE OVER THE TIP OF THE KEWEENAW
PENINSULA WEDNESDAY NIGHT.
TEMPS WERE RAISED SLIGHTLY FOR THURSDAY MORNING /STILL IN THE 20S/.
THEY SHOULD QUICKLY RISE ABOVE 32F AFTER 12Z...DIMINISHING THE NEED
FOR FREEZING RAIN IN THE FCST. AS A RESULT...IT LOOKS TO BE A MAINLY
RAIN OR SNOW EVENT. WILL KEEP THE MENTION OF MODERATE WET SNOW...AND
MIXED PRECIP IN THE HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM
AIR SURGES IN FROM THE S. RAIN MAY RUN ACROSS MUCH OF THE
CWA...EXCLUDING THE KEWEENAW PENINSULA WITH THE BEST CHANCE
STRETCHING FROM WATERSMEET TO ESC AND ISQ FROM 15-21Z THURSDAY. FOR
THURSDAY THROUGH THURSDAY NIGHT 3-6IN OF SNOW WILL BE POSSIBLE
ACROSS MUCH OF THE CWA...WITH MORE LIKE 2-3IN ACROSS MENOMINEE
COUNTY.
ANOTHER CONUNDRUM IS WHEN TO DIMINISH POPS. YES COLD AIR WILL BE
RUSHING IN BEHIND THE EXITING LOW THURSDAY NIGHT...BUT THE ECMWF
ONLY HAS TEMPS FALLING TO AROUND -9C BY 12Z FRIDAY ON FAVORABLE N
WINDS. WITH THE MAIN SHORTWAVE EXITING E UPPER MI AT THAT TIME AND
ZONAL FLOW ALOFT...THE COLDEST AIR WILL REMAIN ACROSS ONTARIO. DRY
HIGH PRESSURE OVER S CANADA AND THE N PLAINS WILL SLOWLY EDGE IN FOR
LATE FRIDAY AFTERNOON THROUGH THE DAY SATURDAY...WITH LITTLE TO NO
SNOW ANTICIPATED.
AN ELONGATED TROUGH EXTENDING FROM THE MAIN SFC-500MB LOW OVER
HUDSON BAY SUNDAY WILL SHIFT ACROSS UPPER MI...BRINGING THE NEXT
CHANCE RAIN AND SNOW TO THE CWA...BUT NOT BEFORE TEMPS BRIEFLY WARM
INTO THE 40S SUNDAY AFTERNOON.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
456 AM EDT TUE MAR 25 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 455 AM EDT TUE MAR 25 2014
LATEST 08Z WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL
RIDGE OVER WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE
ERN CONUS. A SHORTWAVE ROTATING INTO WRN LAKE SUPERIOR PUSHED AN
ARCTIC COLD FRONT THROUGH WRN UPR MI EARLY THIS MORNING. NW OF LAKE
SUPERIOR IN THE WAKE OF THE FRONT...TEMPS ARE GENERALLY AT OR BELOW
ZERO. THIS COLDER AIR MOVING ACROSS LAKE SUPERIOR HAS GENERATED SOME
SCT -SHSN DOWNWIND OF THE LAKE IN A NW FLOW.
TODAY...AS THE SFC HIGH PRESSURE RIDGE AND ASSOC SUBSIDENCE BUILD
INTO THE WRN LAKES LATE THIS MORNING INTO THE AFTERNOON...SOUNDINGS
DRY FM 850-700 MB AND WINDS BACK WRLY...EXPECT LAKE SHSN TO DIMINISH
WITH ACCUMULATIONS GENERALLY AN INCH OR LESS. WITH 925/850 MB TEMPS
ONLY TO AROUND -18/-23C...TEMPS MAY STRUGGLE TO REACH THE LOWER TO
MID TEENS ALONG LAKE SUPERIOR...MORE THAN 20 DEGREES BELOW SEASONAL
AVERAGES.
TONIGHT...A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES
REGION WILL LEAD TO ANOTHER VERY COLD NIGHT TONIGHT ACROSS THE AREA.
WITH WINDS BACKING WSW WOULD NOT THINK LINGERING LAKE CLOUDS SHOULD
NOT BE A FCST CONCERN. THUS...WOULD EXPECT CLEARING SKIES AND IDEAL
RADIATIONAL COOLING CONDITIONS UNDER LIGHT WINDS. SINCE PWAT VALUES
ARE EXPECTED AROUND 30 PERCENT OF NORMAL...CONTINUED TO FCST MIN
TEMPS BLO GUIDANCE...ESPECIALLY IN THE TRADITIONAL INTERIOR COLD
SPOTS. LOOK FOR LOWS BELOW ZERO OVER PRETTY MUCH ALL OF THE U.P. AND
IN THE TEENS BELOW ZERO OVER THE INTERIOR. BASED OFF THE TRENDS IN
THE LONGER RANGE MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD
NIGHT ACROSS THE REGION THIS SEASON.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAR 25 2014
PRELIMINARY THOUGHTS ON LONG TERM FCST.
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S.
WILL KEEP THE MENTION OF MODERATE WET SNOW...AND MIXED PRECIP IN THE
HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM AIR SURGES IN FROM
THE S.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 455 AM EDT TUE MAR 25 2014
EXPECT NW WINDS 20 TO 30 KTS TODAY IN THE WAKE OF AN ARCTIC COLD
FRONT...WITH THE HIGHEST GUSTS OVER THE EASTERN HALF OF LAKE
SUPERIOR. WINDS WILL QUICKLY DIMINISH TONIGHT AND WEDNESDAY AS
ANOTHER HIGH PRESSURE RIDGE MOVES OVER THE AREA. A LOW PRESSURE
SYSTEM DEVELOPING IN THE CENTRAL PLAINS ON WEDNESDAY NIGHT AND
THURSDAY WILL MOVE THROUGH THE GREAT LAKES REGION LATE THURSDAY
NIGHT AND FRIDAY. EXPECT NRLY WINDS 20 TO 30 KTS ON THE BACK SIDE OF
THE LOW THU NIGHT INTO FRI MORNING WITH THE STRONGEST WINDS OVER ERN
LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH FM THE WEST FRI AFTERNOON
INTO SAT AS HIGH PRESSURE BUILDS OVER THE AREA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KF
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
450 AM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 450 AM EDT TUE MAR 25 2014
PRELIMINARY THOUGHTS ON LONG TERM FCST.
S WINDS OF WEDNESDAY WILL HELP RAISE TEMPS ABOUT 10F HIGHER THAN
WHAT WILL BE EXPERIENCED TODAY ACROSS THE CWA...ESPECIALLY W AND N.
THIS WILL BE DESPITE SNOW NEARING FROM THE NW. KEPT A SLIGHT CHANCE
FAR W BY LATE AFTERNOON...ALTHOUGH THE TREND IS TO SLOW DOWN THE
POPS EVEN MORE.
ANOTHER DAY CLOSER TO OUR WEDNESDAY NIGHT THROUGH THURSDAY EVENING
EVENT. WHILE FCST SOLUTIONS HAVE COME A BIT MORE IN LINE...THEY
COULD BE BETTER. EXPECT SIGNIFICANT IMPROVEMENTS AT THE DISTURBANCE
MOVES FROM THE PACIFIC OVER THE BETTER SAMPLED/MODELED CONTINENTAL
U.S.
WILL KEEP THE MENTION OF MODERATE WET SNOW...AND MIXED PRECIP IN THE
HWO. CONTINUE TO EXPECT THE MOST SNOW N AS WARM AIR SURGES IN FROM
THE S.
INCREASED POPS FOR DAY 6/MONDAY AS THE NEXT SFC LOW TRACKS FROM THE
N AND CENTRAL PLAINS SUNDAY AFTERNOON TO THE UPPER GREAT LAKES BY
12Z MONDAY. COMPARING THE 00Z RUNS...THE GFS HAS THE 996MB LOW NEAR
IWD...WHILE THE ECMWF CENTERS THE LOW ACROSS IA. WITH EITHER
SOLUTION...THE BEST CHANCE OF PRECIP LOOKS TO BE W UPPER MI. HAVE
ADDED LIKELY POPS FOR THE KEWEENAW PENINSULA FOR THE DAY MONDAY. AS
FOR SPECIFICS...WE WILL NEED TO WAIT. THE N SOLUTION WOULD BRING
MAINLY RAIN TO THE CWA...WHILE THE ECMWF WOULD RESULT IN MOSTLY
SNOW. WILL KEEP A MIX IN FOR NOW WITH THE BEST CHANCE OF SNOW NW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
121 AM EDT TUE MAR 25 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 415 PM EDT MON MAR 24 2014
WV IMAGERY AND RUC ANALYSIS INDICATED A MID/UPPER LEVEL RIDGE OVER
WRN NOAM AND A TROUGH FROM HUDSON BAY THROUGH MUCH OF THE ERN CONUS.
AN UPSTREAM SHORTWAVE TROUGH AND ASSOCIATED ARCTIC COLD FRONT
EXTENDED FROM NEAR JAMES BAY TO FAR NW MN. TO THE NORTH OF THE FRONT
19Z TEMPS ONLY RANGED FROM 0F TO 5F. AT THE SFC...WRLY LOW LEVEL
FLOW PREVAILED AHEAD OF THE FRONT WITH ONLY SCT-BKN DIURNAL CU/SC
OVER UPPER MICHIGAN.
TONIGHT...AS THE SHORTWAVE TROUGH AND COLD FRONT MOVE ACROSS THE NRN
GREAT LAKES SOME WEAK Q-VECT CONV...SFC-700 MB MOISTENING AND LOW
LEVEL CONV SHOULD SUPPORT SCT LIGHT SNOW SHOWERS OR FLURRIES...PER
UPSTREAM OBS. THE GREATEST PCPN CHANCES AND POTENTIAL FOR SOME LIGHT
ACCUMULATIONS OF AN INCH OR LESS IS EXPECTED DOWNWIND FROM LAKE
SUPERIOR WHERE EVEN SMALL GAPS IN THE ICE COVER WILL ADD
HEAT/INSTABILITY. UPSLOPE FLOW INTO THE HIGHER TERRAIN WILL ALSO
PROVIDE ADDITIONAL SUPPORT FOR THE PCPN. LOOK FOR MIN TEMPS MAINLY IN
THE SINGLE DIGITS ABOVE ZERO BUT A FEW BLO ZERO READINGS ARE POSSIBLE
OVER THE EASTERN INTERIOR FCST AREA WHERE WINDS WILL BE LIGHTER AHEAD
OF THE FRONT IN THE EVENING.
TUESDAY...AS HIGH PRESSURE AND SUBSIDENCE BUILD INTO THE WRN
LAKES...THE 850-700 MB MOISTURE DEPARTS AND WINDS BACK TO
WRLY...EXPECT THE PCPN TO DIMINISH WITH ONLY A LIGHT DUSTING OF
ACCUMULATION AT MOST. WITH 925/850 MB TEMPS ONLY TO AROUND
-16/-22C...TEMPS WILL STRUGGLE THROUGH THE MID TEENS...MORE THAN 20
DEGREES BELOW SEASONAL AVERAGES.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 438 PM EDT MON MAR 24 2014
THE EXTENDED PORTION OF THE FORECAST IS TRENDING TOWARDS A MORE
ACTIVE AND SPRING LIKE PATTERN.
A HIGH PRESSURE RIDGE MOVING OVER THE UPPER GREAT LAKES REGION TO
START THE PERIOD WILL LEAD TO ANOTHER VERY COLD NIGHT ACROSS THE
UPPER GREAT LAKES REGION ON TUESDAY NIGHT. THERE ARE SOME CONCERNS
FOR CLOUDS LINGERING...BUT WITH THE VERY LIMITED OPEN WATER ON LAKE
SUPERIOR WOULD THINK THERE IS A LACK OF SUPPORT FOR LAKE ENHANCED
CLOUDS TO LINGER. THUS...WOULD EXPECT CLEARING SKIES AND A DECENT
OPPORTUNITY FOR RADIATIONAL COOLING WITH WINDS BECOMING LIGHT.
SINCE PWAT VALUES ARE AROUND 30 PERCENT OF NORMAL...OPTED TO TREND
TEMPS DOWN (BASED OFF THE LAST TWO NIGHTS OF LOWS)...ESPECIALLY IN
THE TRADITIONAL INTERIOR COLD SPOTS. THIS PRODUCES LOWS BELOW ZERO
OVER PRETTY MUCH ALL OF THE U.P. AND IN THE TEENS BELOW ZERO OVER
THE INTERIOR. BASED OFF THE TRENDS IN THE LONGER RANGE
MODELS...THIS WILL LIKELY BE THE LAST REALLY COLD NIGHT ACROSS THE
REGION.
THE SURFACE RIDGE WILL QUICKLY SHIFT EAST OF THE AREA ON WEDNESDAY
AND ALLOW SOUTHERLY FLOW TO DEVELOP AHEAD OF THE LOW TAKING SHAPE
IN THE CENTRAL PLAINS. THIS SOUTHERLY FLOW WILL ALLOW TEMPERATURES
TO QUICKLY WARM INTO THE 20S (AIDED BY MORNING SUNSHINE). BUT HIGH
CLOUDS WILL BE QUICKLY STREAMING OVER THE AREA THROUGH THE DAY
AHEAD OF THE NEXT SYSTEM. COULD EVEN SEE A ISOLATED SHOWER OR TWO
DEVELOPING UNDER THE MID LEVEL WAA LATE IN THE AFTERNOON.
THE FIRST WAVE FROM THE SYSTEM WILL AFFECT THE AREA ON WEDNESDAY
NIGHT...AS A SURFACE TROUGH EXTENDING NORTHEAST FROM THE DEVELOPING
SURFACE LOW MOVES EAST OVER THE CWA. BROAD MID LEVEL WARM AIR
ADVECTION AND ISENTROPIC ASCENT ON THE 280-295K SFCS SHOULD LEAD TO
A SWATH OF LIGHT SNOW. AS WITH THE NEXT SYSTEM...MODELS VARY
SIGNIFICANTLY WITH THE STRENGTH AND LOCATION OF THIS AREA OF
SNOW. THE 12Z ECMWF IS THE FARTHEST NORTH (OVER LAKE SUPERIOR) AND
WEAKEST...12Z CANADIAN FARTHEST SOUTH (ACROSS THE U.P.) AND
STRONGEST...WHILE THE GFS IS IN BETWEEN. FELT THAT THE GFS WAS A
GOOD COMPROMISE BETWEEN THE SOLUTIONS AND FOLLOWED THAT FOR TIMING
AND SNOWFALL AMOUNTS. THAT GIVES A GENERAL 1-3 INCHES OF SNOW FOR
THE CWA (GREATEST NORTH THIRD) THROUGH 12Z THURSDAY.
NEXT WAVE OF PRECIP WILL ARRIVE AS THE LOW PULLS OUT OF THE CENTRAL
PLAINS AND THROUGH THE GREAT LAKES REGION. STILL SOME DIFFERENCES IN
THE EXACT TRACK/TIMING BUT AT LEAST INITIALLY THE MODELS ARE
CONSISTENT IN A TROUGH EXTENDING NORTH-NORTHEAST OVER WESTERN LAKE
SUPERIOR. AS FOR THE LOW...THE 12Z GFS CONTINUES TO MOVE THE LOW
THROUGH MUCH FASTER THAN THE 12Z GEM AND 12Z ECMWF (270MI/520MI
NORTHEAST AT 12Z FRIDAY RESPECTIVELY). THE 12Z GEM WAS MUCH FARTHER
TO THE NORTHWEST AND BROUGHT IN MUCH MORE WARM AIR (0C 850MB LINE IN
FAR WESTERN UPPER MICHIGAN AT 00Z FRIDAY). 12Z ECMWF...EVEN WITH
IT/S FARTHER SOUTHWEST LOW TRACK (THROUGH CENTRAL LOWER MI ON
FRIDAY) HAS THE 0C 925MB TEMP AREA SLIDING THROUGH SOUTHERN
UPPER MICHIGAN DURING THE DAY THURSDAY. THE GFS ON THE OTHER
HAND...MOVES THE LOW THROUGH SO FAST THAT THE WARM AIR DOESN/T HAVE
TIME TO PULL INTO THE AREA AND KEEPS IT AS ALL SNOW.
ESSENTIALLY...THESE DIFFERENCES ARE DUE TO THE HANDLING OF THE
DISTURBANCE THAT IS WELL OFFSHORE IN THE PACIFIC AND WON/T COME ON
SHORE UNTIL TUESDAY NIGHT. IT WILL PROBABLY BE 24-36HRS BEFORE THE
MODELS CAN LOCK INTO A SOLUTION...BUT FEEL A SEVERAL MEMBER
COMPROMISE IS REASONABLE (GEM/ECMWF FOR TIMING AND GFS/ECMWF/UKMET
FOR TRACK AND ECMWF FOR THERMAL PROFILE). FELT WEIGHTING MORE
HEAVILY TOWARDS THE ECMWF WAS WARRANTED BASED OFF THE CONSISTENCY
IN THE LOW TRACK WITH THE 00Z ENSEMBLE MEMBERS.
UNFORTUNATELY...THESE DIFFERENCE IN THE LOW TRACK AFFECT BOTH THE
PRECIPITATION TYPE FOR A PORTION OF THE AREA AND ALSO WHERE THE
HEAVIEST PRECIPITATION WILL BE LOCATED WITH THE DEFORMATION BAND ON
THE BACKSIDE OF THE LOW. AS THE LOW IS TAKING SHAPE ON
THURSDAY...SHOULD SEE A TROUGH SETTING UP OVER WESTERN LAKE SUPERIOR
AND WOULD EXPECT THE HEAVIEST PRECIPITATION TO BE OVER THE WESTERN
THIRD OF THE CWA AND THE WESTERN LAKE AS IT WILL BE ENHANCED BY
MID-LEVEL FGEN. OVER THE REST OF THE AREA AND ESPECIALLY THE SOUTH
CENTRAL...WOULD EXPECT THE WAA PRECIPITATION TO SHIFT OUT AND
DIMINISH AND POTENTIALLY CUT OUT THE DEEPER MOISTURE ON THURSDAY.
THIS COULD LEAD TO MORE OF A FOG/DRIZZLE PERIOD...BUT WITH THE
UNCERTAINTY WITH THE LOW TRACK WILL JUST KEEP THINGS AS SNOW WITH
RAIN MIXED IN AT TIMES. THEN AS THE LOW MOVES UP AND THROUGH THE
AREA...THE HEAVIER BAND OF PRECIP WILL SHIFT EAST ACROSS THE CWA
THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. ALL IN ALL...THE
CONDITIONS WEDNESDAY NIGHT INTO FRIDAY MORNING WILL LIKELY LEAD TO A
PERIOD OF MESSY TRAVEL/COMMUTES AND WILL CONTINUE TO HIGHLIGHT IN
THE HWO.
BEHIND THE LOW...HIGH PRESSURE WILL SETTLE OVER THE AREA FOR FRIDAY
NIGHT AND INTO SATURDAY. 850MB TEMPS OF -12C ARE PRETTY MARGINAL
FOR ANY LAKE EFFECT IF POCKETS OF OPEN WATER DEVELOP ON LAKE
SUPERIOR...SO WILL GO WITH DRY CONDITIONS ON FRIDAY NIGHT. THE HIGH
WILL SHIFT EAST ON SATURDAY AND SOUTHERLY FLOW SHOULD LEAD TO HIGHS
IN THE 30S.
FOCUS THEN TURNS TO THE NEXT SERIES OF WAVES COMING FROM THE
WESTERN CONUS AND BRINGING ANOTHER UNSETTLED PERIOD TO THE AREA
THROUGH THE FIRST HALF OF NEXT WEEK. THE FIRST POTENTIAL WAVE LOOKS
TO RUN EAST ON THE U.S./CANADIAN BORDER ON SATURDAY NIGHT AND
SHOULD HAVE A LIMITED AFFECT ON THE LAND CWA. BEHIND THIS
WAVE...MUCH WARMER AIR WILL MOVE INTO THE AREA AND CURRENT
INDICATIONS ARE FOR TEMPERATURES TO BE AT OR EVEN SLIGHTLY ABOVE
NORMAL FOR SUNDAY. GFS CONTINUES TO SHOW ISSUES WITH SNOW COVER AND
SURFACE TEMPS...SO WILL LEVERAGE THE CANADIAN/ECMWF FOR HIGHS ON
SUNDAY. SHOULD SEE 40S OVER MUCH OF THE AREA (EXCEPT OVER THE EAST
WITH WINDS OFF LAKE MICHIGAN) AND THERE IS EVEN THE POTENTIAL FOR
SOME 50S ALONG THE WISCONSIN BORDER. THE NEXT SHORTWAVE AND COLD
FRONT WILL BE SHIFTING THROUGH THE AREA LATE SUNDAY AFTERNOON AND
SUNDAY NIGHT AND WITH THE EXPECTED THERMAL PROFILE...THAT
PRECIPITATION SHOULD MAINLY FALL AS RAIN. LIKE THE END OF THIS
WEEK...ANOTHER LOW TAKING SHAPE IN THE PLAINS STATES ON SUNDAY WILL
LIKELY MOVE THROUGH THE GREAT LAKES REGION ON MONDAY AND MONDAY
NIGHT...BRINGING ANOTHER WIDESPREAD PRECIPITATION EVENT TO THE AREA.
INITIAL THOUGH ON P-TYPE IS FOR A MIX INITIALLY AND TRANSITIONING TO
ALL SNOW THROUGH THE DAY/EVENING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 119 AM EDT TUE MAR 25 2014
WITH THE PASSAGE OF A DISTURBANCE OVERNIGHT...SCT -SHSN WILL LIKELY
DEVELOP AT THE TAF SITES. BY LATE TONIGHT INTO TUE MORNING...THE
COMBINATION OF LOW LEVEL CONV AND UPSLOPE FLOW WILL BE ENOUGH TO
SUPPORT HIGH MVFR CIGS OR LOW VFR CIGS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 415 PM EDT MON MAR 24 2014
A COLD FRONT WILL MOVE THROUGH THE NRN LAKES TONIGHT. BEHIND THE
FRONT...WINDS WILL SHIFT TO THE NORTHWEST AND INCREASE TO 15 TO 25
KT TONIGHT AND 20 TO 30 KTS ON TUESDAY...WITH THE HIGHEST GUSTS OVER
THE EASTERN HALF OF LAKE SUPERIOR. WINDS WILL QUICKLY DIMINISH
TUESDAY NIGHT AND WEDNESDAY AS ANOTHER HIGH PRESSURE RIDGE MOVES
OVER THE AREA. A LOW PRESSURE SYSTEM DEVELOPING IN THE CENTRAL
PLAINS ON WEDNESDAY NIGHT AND THURSDAY WILL MOVE THROUGH THE GREAT
LAKES REGION LATE THURSDAY NIGHT AND FRIDAY. WIND STRENGTH/DIRECTION
WILL DEPEND ON THE EXACT TRACK OF THE LOW...BUT AT THIS TIME NORTH
TO NORTHEAST WINDS OF 15 TO 25 KTS ARE EXPECTED.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
904 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 00z TAFs through 00z Thursday Evening)
Issued at 700 PM CDT Wed Mar 26 2014
Showers that worked their way into western Missouri during the
afternoon will be overspreading western sections of the CWA during
the evening hours. Expect leading edge to reach COU 01-02z, and
the Mississippi River in the 40-06z time frame. Upstream obs
associated with this band of showers would suggest VFR cigs
4-6kft, with vsbys primarily remaining aoa 6sm. Based on 12z and
18z guidance which depicts persist WAA/theta-e advection centered
along the Mississippi River overnight think that axis of precip
will shift east of COU during the predawn hours, but some shower
activity should linger in UIN and the STL metro into early
Thursday morning. Again, have kept cigs aoa 3kft over most of the
area given limited low level moisture return and very strong
mixing, but will be keeping an eye on upstream ceiling trends.
Once the early morning shower activity exits, it looks like most
TAF locations will have a fairly strong cap that will delay threat
of potentially strong convection until mid-late afternoon in COU
and UIN, and in STL metro until early Thursday evening...again,
with VFR cigs until the arrival of the convection.
Strong southerly gradient will continue over the area throughout
the period. Slight dip in surface wind speeds tonight may set up
the potential for low level wind shear after 06z at most
locations, although with no inversion forming some momentum
transfer to the surface should prevent the threat from becoming
extreme. Surface winds should begin to gust once again by mid
morning Thursday with the increase of diurnal heating and
resultant increase in mixing.
Specifics for KSTL: Looking for -SHRA to arrive around 05z, with
some shower activity continuing into the predawn hours due to
persistent WAA into the Mississippi Valley. Do expect cigs to
lower from the current mid cloud deck, but believe that they
should remain primarily VFR in the 3-5kft range during the
overnight hours and into early Wednesday. Showers should push east
of the TAF shortly after sunrise, with 3-5kft cigs continuing
throughout the morning and into the afternoon, as this moisture
will be trapped beneath fairly strong inversion. As mentioned in
the body of the primary discussion there will be some low level
wind shear threat during the predawn hours, but this will diminish
by mid morning Thursday as surface winds begin to gust to around
30 kts.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
702 PM CDT Wed Mar 26 2014
.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 00z TAFs through 00z Thursday Evening)
Issued at 700 PM CDT Wed Mar 26 2014
Showers that worked their way into western Missouri during the
afternoon will be overspreading western sections of the CWA during
the evening hours. Expect leading edge to reach COU 01-02z, and
the Mississippi River in the 40-06z time frame. Upstream obs
associated with this band of showers would suggest VFR cigs
4-6kft, with vsbys primarily remaining aoa 6sm. Based on 12z and
18z guidance which depicts persist WAA/theta-e advection centered
along the Mississippi River overnight think that axis of precip
will shift east of COU during the predawn hours, but some shower
activity should linger in UIN and the STL metro into early
Thursday morning. Again, have kept cigs aoa 3kft over most of the
area given limited low level moisture return and very strong
mixing, but will be keeping an eye on upstream ceiling trends.
Once the early morning shower activity exits, it looks like most
TAF locations will have a fairly strong cap that will delay threat
of potentially strong convection until mid-late afternoon in COU
and UIN, and in STL metro until early Thursday evening...again,
with VFR cigs until the arrival of the convection.
Strong southerly gradient will continue over the area throughout
the period. Slight dip in surface wind speeds tonight may set up
the potential for low level wind shear after 06z at most
locations, although with no inversion forming some momentum
transfer to the surface should prevent the threat from becoming
extreme. Surface winds should begin to gust once again by mid
morning Thursday with the increase of diurnal heating and
resultant increase in mixing.
Specifics for KSTL: Looking for -SHRA to arrive around 05z, with
some shower activity continuing into the predawn hours due to
persistent WAA into the Mississippi Valley. Do expect cigs to
lower from the current mid cloud deck, but believe that they
should remain primarily VFR in the 3-5kft range during the
overnight hours and into early Wednesday. Showers should push east
of the TAF shortly after sunrise, with 3-5kft cigs continuing
throughout the morning and into the afternoon, as this moisture
will be trapped beneath fairly strong inversion. As mentioned in
the body of the primary discussion there will be some low level
wind shear threat during the predawn hours, but this will diminish
by mid morning Thursday as surface winds begin to gust to around
30 kts.
Truett
&&
.FIRE WEATHER:
Issued at Wed 700 PM CDT Wed Mar 26 2014
Winds are slowly backing off and humidities are creeping upward,
so Red Flag Warning was allowed to expire at 7 pm.
Truett/Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1234 AM CDT TUE MAR 25 2014
.UPDATE...
ISSUED AT 1233 AM CDT TUE MAR 25 2014
TOUGH TO GET A GRIP ON HOURLY TEMP TRENDS GIVEN VARIABLE WINDS/
CLOUDS ACROSS THE FCST AREA.
A BATCH OF MULTI-LAYERED CLOUDS IS MOVING THRU ASSOCIATED WITH A
WEAK SHORTWAVE TROF. SATELLITE TRENDS SUPPORT THE HI-RES RAP AND
THE NSSL WRF SYNTHETIC IR IMAGERY. WE EXPECT SKIES TO BE MOSTLY
CLEAR BY DAYBREAK OVER S-CNTRL NEB. N-CNTRL KS COULD START THE DAY
WITH MOSTLY CLOUDY SKIES...BUT EXPECT RAPID CLEARING AFTER
SUNRISE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 1233 AM CDT TUE MAR 25 2014
ALOFT: THE LONGWAVE FLOW WILL DEAMPLIFY OVER THE NEXT 24 HRS AS
TROF OVER THE E PAC GETS FORCED ONSHORE. NW FLOW TODAY WILL BEGIN
THE TRANSITION TONIGHT AS THE WRN USA RIDGE ADVANCES OVER THE
PLAINS.
SURFACE: STRONG HIGH PRES WAS SLIPPING SE AND WAS OVER THE
DAKOTAS THIS MORNING. THIS HIGH WILL SHIFT E INTO THE MS VALLEY
TODAY...WITH S FLOW DEVELOPING LATE. THE PRES GRADIENT WILL
INCREASE TONIGHT AS LOW PRES FORMS OVER MT AND LEE-SIDE TROFFING
DEVELOPS.
MORE LATER...
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 310 PM CDT MON MAR 24 2014
THE WEDNESDAY/THURSDAY PERIODS ARE LOOKING MORE ACTIVE
WEATHERWISE...THEN TEMPERATURES TREND UP FOR THE WEEKEND.
HEIGHTS RISE TUESDAY NIGHT AS A LOW AMPLITUDE UPPER RIDGE AXIS
BUILDS OUT OF THE ROCKIES AND ONTO THE CENTRAL PLAINS. AT THE
SURFACE...LOW PRESSURE SYSTEMS DEEPEN ALONG THE HIGH PLAINS IN SW SD
AND NW KS DURING THE AFTN WED. SOUTHERLY LLVL FLOW INCREASES IN A
TIGHTENING PRESSURE GRADIENT AHEAD OF THE APPROACHING SFC
TROUGH/COLD FRONT. SOUTHERLY WINDS ARE PROGGED TO INCREASE TO
WINDY CONDITIONS DURING THE AFTN...ESPECIALLY ACROSS THE EASTERN
HALF OF OUR CWA WHILE TO THE WEST WIND SPEEDS WILL BEGIN TO
DIMINISH AS THE TROUGH AXIS MOVES IN. MODEL FORECAST SOUNDINGS
INDICATE MIXING FOR OUR EASTERN AREAS AROUND H825 WITH WINDS AT
THE TOP OF THE LAYER NEAR 40KTS. THE LATEST GUIDANCE SUGGEST
SOUTHERLY WINDS NEARING WIND ADVISORY CRITERIA AND WILL NEED TO
MONITOR FOR A POTENTIAL HEADLINE AS THINGS GET CLOSER. THE STEADY
SOUTHERLY WINDS WILL ALSO DRAW MOISTURE NORTHWARD AND SFC DPS ARE
PROGGED TO RISE TO THE UPPER 30S/LOW 40S WITH THE HIGHER DPS
PROGGED TO POOL N/S ALONG THE SFC TROUGH. THE NAM IS THE MOST
ROBUST WITH THE HIGHER DPS AND EVEN SUGGEST READING IN THE UPPER
40S/NEAR 50F NEAR THE WESTERN EDGE OF OUR CWA. WITH THE HIGHER DPS
PROGGED...INSTABILITY PARAMETERS INCREASE ALONG OUR WESTERN CWA
IN THE AFTN WITH MUCAPES PROGGED JUST OVER 1000 J/KG. THE PROGGED
INSTABILITY PER THE NAM MAY BE ON THE HIGH SIDE...BUT EVEN THE
SREF HAS LIKELY PROBS OF INSTABILITY GREATER THAN 500 J/KG. WITH
SUPPORT OF OTHER MODELS WILL GO AHEAD AND INSERT THE POTENTIAL FOR
THUNDER IN THE EVENING. TEMPERATURES WILL BE QUITE MILD WITH H85
TEMPS RANGING FROM 5 TO 15C E/W AND TEMPS SHOULD REACH THE UPPER
50S TO UPPER 60S FOR HIGHS...AND MAY APPROACH 70F IN THE WEST
WHICH ARE AROUND CONVECTIVE TEMPS. ALSO HAVE CONCERNS FOR FIRE
WEATHER CONDITIONS AND WILL NEED TO MONITOR HOW MUCH MOISTURE
ACTUALLY ADVECTS NORTH VS MIXES OUT WITH THE STEADY/GUSTY WINDS.
CURRENT RELATIVE HUMIDITY FORECAST KEEPS RH VALUES ABOVE CRITICAL
FIRE WEATHER CONDITIONS.
THERE ARE MODEL DIFFERENCES ON THE STRENGTH OF THE MID LEVEL
SHORTWAVE TROUGH...AND HOW PROGRESSIVE THE SYSTEM WILL BE AS IT
CROSSES THE CENTRAL PLAINS. THE 00Z ECMWF...12Z GEM...AND 12Z
UKMET ALL SUGGEST A DEEPER/SLOWER SYSTEM TO IMPACT THE CENTRAL
PLAINS AND GENERATE BANDED PCPN DUE TO FRONTOGENESIS AND
DEFORMATION AS THE H7 LOW CLOSES OFF. THESE MODELS ARE THE WORSE
CASE SCENARIO FOR OUR AREA AND DEVELOP A BAND OF SNOWFALL ACROSS
PORTIONS OF WESTERN/NORTHERN AND CENTRAL NEBRASKA...WHILE FARTHER
SOUTH INTO KANSAS THE MAJORITY OF THE AREA IS DRY SLOTTED
INITIALLY WITH CHCS FOR PCPN INCREASING AS COLD FRONT/MID LEVEL
TROUGH MOVE THROUGH. BOTH THE NAM...GFS AND 12Z ECMWF ARE
PROGRESSIVE WITH THE SYSTEM WITH JUST A QUICK SHOT OF PCPN WITH
THE COLD FRONT AND WEAKER TROUGH WITH SOME CHC FOR A TEMP RECOVERY
IN OUR WEST BEHIND THE SYSTEM. HARD TO TELL WHICH SOLUTION WILL
VERIFY IN THIS COMPLICATED TIME FRAME AND WPC DISCUSSION FAVORS
THE ECMWF/UKMET. SINCE THERE IS STILL A FAIR AMOUNT OF
UNCERTAINTY...FEEL COMFORTABLE WITH CHANCE POPS ATTM WHICH CAN BE
ADJUSTED UP/DOWN AS THINGS GET CLOSER. PCPN TYPE WILL BE
DEPENDENT UPON STRENGTH OF SYSTEM AND LLVL TEMP PROFILE BUT AT
LEAST SOME CHC OF SNOW LOOKS REASONABLE WITH SNOW ACCUMULATIONS
POSSIBLE. TEMP TREND LOOKS BE NON DIURNAL WITH CAA BEHIND THE
FRONT.
BEYOND THURSDAY...HEIGHTS RISE AGAIN AND A WARMER AIR SETTLES IN FOR
SEVERAL DAYS WITH TEMPS REACHING THE 60S/70S FOR THE WEEKEND BEFORE
ANOTHER COOL FRONT ARRIVES MONDAY.
&&
.AVIATION...(FOR THE 06Z TAF THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1233 AM CDT TUE MAR 25 2014
THRU 12Z: MULTI-LAYERED VFR CIGS WILL DEPART WITH CLEARING
EXPECTED BY 10Z. NW WINDS 8-12 KTS. CONFIDENCE: HIGH
TUE: ESSENTIALLY VFR SKC. WINDS WILL AVERAGE NW AROUND 10 KTS
UNTIL 18Z. THEN WINDS WILL GRADUALLY SHIFT TO WSW BY 23Z.
CONFIDENCE: HIGH
TUE EVE: VFC SKC. WINDS WILL CONTINUE SHIFTING THRU SW-S-SE AND
WILL INCREASE TO AROUND 15 KTS BY 05Z. THERE COULD BE SOME
OCCASIONAL GUSTINESS. LLWS WILL BECOME A PROBLEM AFTER 06Z.
CONFIDENCE: HIGH
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...HALBLAUB
SHORT TERM...HALBLAUB
LONG TERM...FAY
AVIATION...HALBLAUB
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
626 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 626 AM TUESDAY...A STEADY STRATIFORM RAINFALL EARLY THIS
MORNING IS GRADUALLY OVER-TAKING THE DRY LOW-LVL AND MID-LVL
AIR AS MORE SITES ARE REPORTING -RA AT 10Z/6AM. INITIALLY THE
COAST REMAINS FAVORED FOR PCPN...THEN A GOOD CHANCE AREA-WIDE
AS THE UPPER TROUGH PUSHES THROUGH IN THE AFTERNOON. NO MAJOR
CHANGES EXPECT FINE-TUNING THE DEWPOINT AND TEMPERATURE TRENDS AS
EVAPORATIVE COOLING TAKES PLACE THIS MORNING. THE PREVIOUS EARLY
MORNING DISCUSSION FOLLOWS.
A LOW PRESSURE CENTER ROUGHLY 300 MILES SOUTH OF CAPE FEAR EARLY
THIS MORNING WILL TRACK TO THE NE AND DEEPEN RAPIDLY TODAY...TO
APPROXIMATELY A 997 MB LOW 250 MILES EAST OF CAPE FEAR BY 21Z/5PM.
THE BOMBING SURFACE LOW ALTHOUGH WELL OFFSHORE...IN TANDEM WITH AN
APPROACHING TROUGH/COOL POOL ALOFT...WILL SET OFF PRECIPITATION
TODAY. INITIALLY STRATIFORM RAIN ACROSS OUR EASTERN HALF...WILL
TRANSITION TO MORE SHOWERY TYPE PRECIPITATION AREA-WIDE INTO
AFTERNOON AS THE UPPER TROUGH TRAVERSES THE REGION.
NORMALLY AN UPPER TROUGH IN SPRING RAISES A FLAG TO INTERROGATE
THE SEVERE WEATHER POTENTIAL. IN THIS CASE ALL OF THE FAVORABLE
INGREDIENTS REMAIN LINKED TO THE SURFACE FEATURE OFFSHORE. COOL
LOW-LEVELS OVER LAND AND LOW DEWPOINTS SHOULD PREVENT ROBUST
CONVECTION. HAIL SHOWERS THIS TIME OF YEAR BECOME MORE COMMON
BUT AM NOT SEEING THE VERTICAL VELOCITIES TODAY SUPPORTING THIS.
A FREEZE WATCH HOISTED FOR ALL ZONES FOR EARLY WEDNESDAY MORNING.
CONFIDENCE IS NOT HIGH THAT ALL ZONES WILL DROP BELOW 32 DEGREES
SINCE LOW-LEVEL WINDS WILL BE ELEVATED...AND RESIDUAL CLOUDS MAY
LINGER LATE IN THE NIGHT. IT APPEARS THE BEST CHANCE OF FREEZING
IS INLAND...WHILE CLOSER TO THE COAST...CONFIDENCE LEVEL FALLS.
THUS A WATCH IS IN EFFECT TO ALLOW THE 12Z MODEL DATA SUITE TO
HOPEFULLY PROVIDE ADDITIONAL RESOLUTION IN SEGMENTING A WARNING
VERSUS NO FREEZE WARNING. COUPLING IN WIND...THE APPARENT TEMPS
OR WIND-CHILLS...WILL FALL INTO THE LOW TO MID 20S PRIOR TO AND
THROUGH DAYBREAK ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...THE MAIN EMPHASIS OF THE SHORT TERM WILL BE
THURSDAY MORNING WHEN ARCTIC HIGH PRESSURE SETTLES DIRECTLY
OVERHEAD. THIS COURTESY OF A RELATIVELY DEEP ALBEIT PROGRESSIVE
EAST COAST TROUGH.
GUIDANCE HAS IF ANYTHING JOGGED DOWN A BIT AS HAS THE OFFICIAL
FORECAST. MUCH LIKE A COUPLE OF WEEKS AGO WHEN GUIDANCE WAS VERY
CONSISTENT FOR SEVERAL CYCLES/DAYS...THERE APPEARS TO BE NO
MITIGATING FACTORS FOR A SIGNIFICANT LATE SEASON FREEZE. RETURN FLOW
CONTINUES TO SET UP LATER LATER THURSDAY WITH WHAT SEEMS TO BE A
GOOD SEA FOG SIGNAL FROM THE GFS. ONE FINAL NOTE...WITH THE
AFOREMENTIONED CONFIDENCE SIGNALS FOR A FREEZE...WOULD NORMALLY
ISSUE A NPW BUT WILL HAVE TO LET A MORE MARGINAL EVENT TRANSPIRE FOR
WEDNESDAY A.M.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 AM TUESDAY...ZONAL FLOW ALOFT CONTINUES TO ADVERTISE ONE SYSTEM
MOVING ACROSS THE TENNESSEE VALLEY SATURDAY/EARLY SUNDAY. GUIDANCE
HAS COME INTO SLIGHTLY BETTER AGREEMENT THIS MORNING ON THIS
SCENARIO. CONTINUED TO ADVERTISE POPS FOR FRIDAY AS WELL WITH LOW
LEVEL CONVERGENCE AND PRE FRONTAL TROUGH. I DID ADD SLIGHT COVERAGE
OF THUNDER AS WELL. MORE CONFIDENCE IN DRY CONDITIONS SUNDAY AND
MONDAY. TEMPERATURE GUIDANCE HAS TRENDED DOWN A LITTLE WITH FOR
THESE DAYS AS HAS THE OFFICIAL FORECAST.
&&
.AVIATION /10Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 626 AM TUESDAY...GALE FLAGS RAISED FOR RAPIDLY INTENSIFYING
NW WINDS LATE THIS AFTERNOON THROUGH TONIGHT AS A POWERFUL AND
RAPIDLY DEEPENING SURFACE LOW PASSES WELL EAST OF THE COASTAL
WATERS. ITS INTERACTION WITH APPROACHING CANADIAN HIGH PRESSURE
WILL DRIVE 25-40 KT WINDS FROM THE NW TONIGHT...HIGHEST OFFSHORE.
HIGHEST SEAS AS WELL OFFSHORE IN THE NW WIND TRAJECTORY. THE OCEAN
WILL BECOME DANGEROUS LATER TODAY AS THE NW WIND RIPS ACROSS
STRONG SE WAVE ENERGY...MAKING FOR A PITCHY AND TUMULTUOUS SEA
BEHAVIOR. MARINERS ARE ADVISED TO REMAIN IN PORT TONIGHT. TSTMS
SHOULD REMAIN CONFINED TO THE GULF STREAM THROUGH EARLY WEDNESDAY.
SEA HEIGHTS PEAKING 4 TO 8 FT TONIGHT...BUT DROPPING TO 3 TO 6 FT
INTO FIRST LIGHT OF WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...MUCH LIKE THE PUBLIC PART OF THE FORECAST
GUIDANCE...WINDS AND SEAS REMAIN RELATIVELY UNCHANGED. STILL EXPECT
RUGGED CONDITIONS FOR MOST OF THE DAY WEDNESDAY AS SEAS WILL REMAIN
CHURNED UP AS WINDS DIMINISH.
INITIAL WIND SPEEDS WILL BE 20-25 KNOTS FROM THE NORTHWEST
DECREASING TO 10-15 BY MID EVENING. BY THURSDAY WINDS DROP EVEN
FURTHER AS SURFACE HIGH PRESSURE DRIFTS DIRECTLY OVERHEAD. EXPECT
SPEEDS OF TEN KNOTS OR LESS. LATER THURSDAY WINDS SLOWLY RECOVER TO
10-15 KNOTS THIS TIME FROM THE SOUTHEAST.
SEAS WILL CERTAINLY BE MORE ROBUST ACROSS THE OUTER PORTIONS OF THE
COASTAL ZONES WITH THE OFFSHORE FLOW. EXPECT 3-5 FEET WITH
POSSIBLE SIX FOOTERS FOR MOST OF THE DAY WITH HEIGHTS DROPPING
DRAMATICALLY THURSDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 345 AM TUESDAY...WINDS WILL INITIALLY BE FROM THE SOUTH AT
A FAIRLY DECENT CLIP...15-20 KNOTS AND THERE MAY BE SOME SEA FOG
TO CONTEND WITH AS WELL. WITH AN INITIAL SURFACE SYSTEM LOSING
SOME STRENGTH...WINDS ACTUALLY DECREASE SLIGHTLY FOR SATURDAY
WHILE SWITCHING TO THE NORTH VERY LATE. NOT A STRONG SURGE OF COLD
AIR WITH THIS ONE KEEPING SPEEDS RELATIVELY LIGHT. SEAS ARE 3-5
FEET EARLY WITH THE PERSISTENCE AND STRENGTH OF THE RETURN FLOW
DIMINISHING A BIT WITH WIND SPEEDS LATER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
SCZ017-023-024-032-033-039-053>056.
NC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
NCZ087-096-099-105>110.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC/MRR
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
344 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...A LOW PRESSURE CENTER ROUGHLY 300 MILES
SOUTH OF CAPE FEAR EARLY THIS MORNING WILL TRACK TO THE NE AND
DEEPEN RAPIDLY TODAY...TO APPROXIMATELY A 997 MB LOW 250 MILES
EAST OF CAPE FEAR BY 21Z/5PM. THE BOMBING SURFACE LOW ALTHOUGH
WELL OFFSHORE...IN TANDEM WITH AN APPROACHING TROUGH/COOL POOL
ALOFT...WILL SET OFF PRECIPITATION TODAY. INITIALLY STRATIFORM
RAIN ACROSS OUR EASTERN HALF...WILL TRANSITION TO MORE SHOWERY
TYPE PRECIPITATION AREA-WIDE INTO AFTERNOON AS THE UPPER TROUGH
TRAVERSES THE REGION.
NORMALLY AN UPPER TROUGH IN SPRING RAISES A FLAG TO INTERROGATE
THE SEVERE WEATHER POTENTIAL. IN THIS CASE ALL OF THE FAVORABLE
INGREDIENTS REMAIN LINKED TO THE SURFACE FEATURE OFFSHORE. COOL
LOW-LEVELS OVER LAND AND LOW DEWPOINTS SHOULD PREVENT ROBUST
CONVECTION. HAIL SHOWERS THIS TIME OF YEAR BECOME MORE COMMON
BUT AM NOT SEEING THE VERTICAL VELOCITIES TODAY SUPPORTING THIS.
A FREEZE WATCH HOISTED FOR ALL ZONES FOR EARLY WEDNESDAY MORNING.
CONFIDENCE IS NOT HIGH THAT ALL ZONES WILL DROP BELOW 32 DEGREES
SINCE LOW-LEVEL WINDS WILL BE ELEVATED...AND RESIDUAL CLOUDS MAY
LINGER LATE IN THE NIGHT. IT APPEARS THE BEST CHANCE OF FREEZING
IS INLAND...WHILE CLOSER TO THE COAST...CONFIDENCE LEVEL FALLS.
THUS A WATCH IS IN EFFECT TO ALLOW THE 12Z MODEL DATA SUITE TO
HOPEFULLY PROVIDE ADDITIONAL RESOLUTION IN SEGMENTING A WARNING
VERSUS NO FREEZE WARNING. COUPLING IN WIND...THE APPARENT TEMPS
OR WIND-CHILLS...WILL FALL INTO THE LOW TO MID 20S PRIOR TO AND
THROUGH DAYBREAK ON WEDNESDAY.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...THE MAIN EMPHASIS OF THE SHORT TERM WILL BE
THURSDAY MORNING WHEN ARCTIC HIGH PRESSURE SETTLES DIRECTLY
OVERHEAD. THIS COURTESY OF A RELATIVELY DEEP ALBEIT PROGRESSIVE
EAST COAST TROUGH.
GUIDANCE HAS IF ANYTHING JOGGED DOWN A BIT AS HAS THE OFFICIAL
FORECAST. MUCH LIKE A COUPLE OF WEEKS AGO WHEN GUIDANCE WAS VERY
CONSISTENT FOR SEVERAL CYCLES/DAYS...THERE APPEARS TO BE NO
MITIGATING FACTORS FOR A SIGNIFICANT LATE SEASON FREEZE. RETURN FLOW
CONTINUES TO SET UP LATER LATER THURSDAY WITH WHAT SEEMS TO BE A
GOOD SEA FOG SIGNAL FROM THE GFS. ONE FINAL NOTE...WITH THE
AFOREMENTIONED CONFIDENCE SIGNALS FOR A FREEZE...WOULD NORMALLY
ISSUE A NPW BUT WILL HAVE TO LET A MORE MARGINAL EVENT TRANSPIRE FOR
WEDNESDAY A.M.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 345 AM TUESDAY...ZONAL FLOW ALOFT CONTINUES TO ADVERTISE ONE SYSTEM
MOVING ACROSS THE TENNESSEE VALLEY SATURDAY/EARLY SUNDAY. GUIDANCE
HAS COME INTO SLIGHTLY BETTER AGREEMENT THIS MORNING ON THIS
SCENARIO. CONTINUED TO ADVERTISE POPS FOR FRIDAY AS WELL WITH LOW
LEVEL CONVERGENCE AND PRE FRONTAL TROUGH. I DID ADD SLIGHT COVERAGE
OF THUNDER AS WELL. MORE CONFIDENCE IN DRY CONDITIONS SUNDAY AND
MONDAY. TEMPERATURE GUIDANCE HAS TRENDED DOWN A LITTLE WITH FOR
THESE DAYS AS HAS THE OFFICIAL FORECAST.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 345 AM TUESDAY...GALE FLAGS RAISED FOR RAPIDLY INTENSIFYING
NW WINDS LATE THIS AFTERNOON THROUGH TONIGHT AS A POWERFUL AND
RAPIDLY DEEPENING SURFACE LOW PASSES WELL EAST OF THE COASTAL
WATERS. ITS INTERACTION WITH APPROACHING CANADIAN HIGH PRESSURE
WILL DRIVE 25-40 KT WINDS FROM THE NW TONIGHT...HIGHEST OFFSHORE.
HIGHEST SEAS AS WELL OFFSHORE IN THE NW WIND TRAJECTORY. THE OCEAN
WILL BECOME DANGEROUS LATER TODAY AS THE NW WIND RIPS ACROSS
STRONG SE WAVE ENERGY...MAKING FOR A PITCHY AND TUMULTUOUS SEA
BEHAVIOR. MARINERS ARE ADVISED TO REMAIN IN PORT TONIGHT. TSTMS
SHOULD REMAIN CONFINED TO THE GULF STREAM THROUGH EARLY WEDNESDAY.
SEA HEIGHTS PEAKING 4 TO 8 FT TONIGHT...BUT DROPPING TO 3 TO 6 FT
INTO FIRST LIGHT OF WEDNESDAY.
SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
AS OF 345 AM TUESDAY...MUCH LIKE THE PUBLIC PART OF THE FORECAST
GUIDANCE...WINDS AND SEAS REMAIN RELATIVELY UNCHANGED. STILL EXPECT
RUGGED CONDITIONS FOR MOST OF THE DAY WEDNESDAY AS SEAS WILL REMAIN
CHURNED UP AS WINDS DIMINISH.
INITIAL WIND SPEEDS WILL BE 20-25 KNOTS FROM THE NORTHWEST
DECREASING TO 10-15 BY MID EVENING. BY THURSDAY WINDS DROP EVEN
FURTHER AS SURFACE HIGH PRESSURE DRIFTS DIRECTLY OVERHEAD. EXPECT
SPEEDS OF TEN KNOTS OR LESS. LATER THURSDAY WINDS SLOWLY RECOVER TO
10-15 KNOTS THIS TIME FROM THE SOUTHEAST.
SEAS WILL CERTAINLY BE MORE ROBUST ACROSS THE OUTER PORTIONS OF THE
COASTAL ZONES WITH THE OFFSHORE FLOW. EXPECT 3-5 FEET WITH
POSSIBLE SIX FOOTERS FOR MOST OF THE DAY WITH HEIGHTS DROPPING
DRAMATICALLY THURSDAY.
LONG TERM /FRIDAY THROUGH SATURDAY/...
AS OF 345 AM TUESDAY...WINDS WILL INITIALLY BE FROM THE SOUTH AT
A FAIRLY DECENT CLIP...15-20 KNOTS AND THERE MAY BE SOME SEA FOG
TO CONTEND WITH AS WELL. WITH AN INITIAL SURFACE SYSTEM LOSING
SOME STRENGTH...WINDS ACTUALLY DECREASE SLIGHTLY FOR SATURDAY
WHILE SWITCHING TO THE NORTH VERY LATE. NOT A STRONG SURGE OF COLD
AIR WITH THIS ONE KEEPING SPEEDS RELATIVELY LIGHT. SEAS ARE 3-5
FEET EARLY WITH THE PERSISTENCE AND STRENGTH OF THE RETURN FLOW
DIMINISHING A BIT WITH WIND SPEEDS LATER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
SCZ017-023-024-032-033-039-053>056.
NC...FREEZE WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING FOR
NCZ087-096-099-105>110.
MARINE...GALE WARNING FROM 6 PM THIS EVENING TO 6 AM EDT WEDNESDAY FOR
AMZ250-252-254-256.
&&
$$
SYNOPSIS...MJC
NEAR TERM...MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS RALEIGH NC
252 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 250 AM TUESDAY...
WED AND WED NIGHT: IN THE WAKE OF THE BOMBING CYCLONE TRACKING UP
THE MIDDLE ATLANTIC AND NEW ENGLAND COASTS...A STILL STRONG MSL
PRESSURE GRADIENT - AND ASSOCIATED CONTINUED BLUSTERY NW WINDS -
WILL RELAX/ABATE THROUGHOUT THE AFTERNOON...AS THE CENTER OF
MODIFIED ARCTIC HIGH PRESSURE BUILDS ACROSS THE APPALACHIANS. ASIDE
FROM INCREASING HIGH CLOUDS WITH THE APPROACH OF A SOUTHERN STREAM
WAVE ALOFT BY THU MORNING...PARTICULARLY OVER THE SOUTHERN PIEDMONT
AND SANDHILLS...THE PRESENCE OF THE HIGH WILL YIELD MAINLY CLEAR AND
CHILLY CONDITIONS. TEMPERATURES WITHIN A FEW DEGREES EITHER SIDE OF
45 AND 25 DEGREES FOR HIGHS AND LOWS...RESPECTIVELY...WITH THE
LATTER SUPPORTED BY STRONG RADIATIONAL COOLING WITH THE CENTER OF
THE HIGH OVERHEAD. DESPITE THESE CHILLY CONDITIONS...THE COMBINATION
OF STRONG NW WINDS AND MINIMUM RELATIVE HUMIDITY VALUES AROUND 25
PERCENT OWING TO THE DRY ARCTIC AIR MASS - THOUGH WITH ONLY A BRIEF
OVERLAP OF THESE CONDITIONS DURING THE EARLY AFTERNOON HOURS (IE. RH
HIGHER WHEN WINDS ARE HIGHER EARLY IN THE DAY...THEN WINDS DIMINISH
AS RH DROPS LATE IN THE AFTERNOON)...MAY PRODUCE INCREASED FIRE
DANGER. WE WILL LIKELY COORDINATE WITH THE NCFS REGARDING THIS
POTENTIAL LATER TODAY. -MWS
THURSDAY: THURSDAY WILL START OUT WITH A STRONG 1035 MB SURFACE HIGH
PRESSURE CENTERED OVER COASTAL NC. WHILE THE DAY MIGHT START OUT
FAIRLY CLOUD FREE...EXPECT MID AND UPPER LEVEL CLOUDS TO QUICKLY
SHROUD MOST OF THE CWA BY LATE MORNING/EARLY AFTERNOON. DESPITE THE
CLOUD COVER...NO PRECIPITATION IS EXPECTED. WHILE GUIDANCE SUGGESTS
MAX TEMPERATURES IN THE UPPER 50S...THICKNESSES AND CLOUD COVER
SUGGEST COOLER TEMPS...FOR NOW WILL GO MID 50S NORTH TO UPPER 50S IN
THE SOUTH. -ELLIS
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 240 AM TUESDAY...
THURSDAY NIGHT THROUGH SATURDAY NIGHT: THE FIRST HALF OF THE LONG
TERM IS SETTING UP TO BE A FAIRLY WET PERIOD WITH THE FIRST ACT
BEGINNING WITH AN IN-SITU DAMMING EVENT AS THE 1035 MB SURFACE HIGH
MOVES OUT INTO THE WESTERN ATLANTIC. ISENTROPIC LIFT HIGHLIGHTED ON
THE 290 K SURFACE SUPPORTS AT LEAST SOME LOW LEVEL CLOUDS MOVING
INTO CENTRAL NC WITH PERHAPS EVEN SOME VERY LIGHT PRECIPITATION.
OVERNIGHT LOWS IN TEH LOW TO MID 40S.
ON FRIDAY SURFACE LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
WITH AN ATTENDANT COLD FRONT STRETCHING SOUTHWESTWARD. EARLY IN THE
DAY...MOISTURE TRANSPORT AND CONVERGENCE WILL INCREASE SIGNIFICANTLY
THROUGH THE DAY ON FRIDAY WITH PRECIPITABLE WATER VALUES RISING
ABOVE AN INCH BY FRIDAY AFTERNOON 1.25 INCHES BY EVENING. THE MAIN
PRE-FRONTAL PRECIPITATION WILL HOLD BACK ACROSS THE MOUNTAINS FRIDAY
MORNING AND ANY PRECIPITATION OCCURRING ACROSS CENTRAL NC WOULD BE
LIGHT AND ASSOCIATED MORE WITH MOISTURE CONVERGENCE IN THE SOUTHERLY
RETURN FLOW. THAT WILL CHANGE AFTER 18Z HOWEVER...WHEN PRECIP
OVERSPREADS MUCH OF THE CWA. MODEL FORECAST SOUNDINGS ARE VERY WET
THROUGH THE COLUMN WITH SOME BUT VERY WEAK INSTABILITY. WHILE BULK
SHEAR WILL BE AROUND 40 KTS...THE WEAK CAPE VALUES LOOK TO ONLY
SUPPORT SHOWERS BUT CAN NOT RULE OUT A FEW THUNDERSTORMS IN THE
EXTREME SOUTHEAST. THERE IS SOME UNCERTAINTY AS TO COVERAGE AND QPF
AMOUNTS AT THIS TIME BUT WILL KEEP A COUPLE TENTHS OF AN INCH
POSSIBLE BY THE END OF THE EVENING ON FRIDAY. TEMPERATURES IN THE
LOW 60S NW TO UPPER 60S SE. THE FRONT WILL HAVE TROUBLE GETTING
THROUGH THE AREA ON FRIDAY NIGHT AND AT THIS POINT LOOKS LIKE
CENTRAL NC WILL REMAIN IN THE WARM SECTOR AT LEAST INTO SATURDAY
MORNING. LOWS UPPER 40S TO MIDDLE 50S.
SATURDAY WILL CONTINUE TO BE WET AS THE FRONT LINGERS NORTHWEST OF
THE AREA. THIS WONT LAST FOREVER THOUGH AS THE UPPER TROUGH BEGINS
TO DIG INTO THE MISSISSIPPI VALLEY AND WILL EVENTUALLY GIVE THE
SUPPORT NEEDED TO PUSH THE FRONT THROUGH AND THE SYSTEM OUT TO SEA.
THE DETAILS OF HOW THIS WILL EVOLVE THOUGH REMAIN IN QUESTION BUT
ARE NOW COMING INTO BETTER AGREEMENT. BOTH MODELS NOW DEVELOP A
SOUTHERN STREAM WAVE WEST OF THE MOUNTAINS AND MOVE NORTH OF THE
AREA THROUGH THE MID ATLANTIC...PUSHED OUT TO SEA BY THE UPPER
TROUGH WHERE IT WILL LINK UP WITH A WEAKER WAVE OF LOW PRESSURE
COMING OUT OF THE GULF OF MEXICO AND UP THE EAST COAST. AN UPPER LOW
MOVES ACROSS NC BUT DOES NOT REALLY PHASE WITH THE LOW COMING UP THE
COAST. SATURDAY WILL BE WET AND OVERCAST WITH HIGHS IN THE MID TO
UPPER 60S. FORECAST SOUNDINGS SHOW MUCH BETTER INSTABILITY ON
SATURDAY THAN FOR FRIDAY WITH AS MUCH AS 800 J/KG IN THE SOUTHEAST
WITH 35-40 KTS OF BULK SHEAR MAKING THUNDERSTORMS A MUCH BETTER
POSSIBILITY FROM THE TRIANGLE SOUTH AND EASTWARD THAN ON FRIDAY
AFTERNOON. WILL INCLUDE THE CHANCE FOR THUNDER IN THE FORECAST FOR
SATURDAY EVENING WITH FURTHER DETAILS TO BE IRONED OUT IN THE COMING
DAYS. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH WINDS
SHIFTING FROM SOUTHWESTERLY TO NORTHERLY WITH PRECIPITATION ENDING
AROUND DAYBREAK SUNDAY MORNING. LOWS SATURDAY NIGHT LOW TO MID 40S.
SUNDAY THROUGH MONDAY: MUCH DRIER FOR SUNDAY AND MONDAY AS SURFACE
HIGH PRESSURE EXTENDS ACROSS THE EASTERN SEABOARD WITH RIDGING
ALOFT. MONDAY WILL START OUT COOL ON THE EASTERN SIDE OF THE SURFACE
HIGH WITH NORTHERLY WINDS BUT THESE WILL BECOME VARIABLE BY MONDAY
AFTERNOON WITH HIGH PRESSURE MOVING MORE DIRECTLY OVERHEAD AND THEN
EAST OF THE AREA. HIGHS MONDAY IN THE MIDDLE 60S. LOWS IN THE UPPER
30S TO LOW 40S. A WARMING TREND FOR MONDAY AS SOUTHERLY RETURN FLOW
TAKES OVER AND THICKNESSES INCREASE BACK INTO THE 1350S. THIS SHOULD
SUPPORT HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM/ELLIS
LONG TERM...ELLIS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
242 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 240 AM TUESDAY...
UPPER TROF SHIFTS EAST AND THE COASTAL STORM LIFTS NORTHEAST QUICKLY
ON WEDNESDAY...WITH CLEAR SKIES AND THE PRESSURE GRADIENT RELAXING
AS THE MORNING PROGRESSES. COLD AIR ADVECTION WILL BE WELL
UNDERWAY...COMPLIMENTS OF SURFACE HIGH PRESSURE BUILDING IN FROM THE
WEST...WITH NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS TO 25 MPH AROUND
DAYBREAK...WITH GUSTS DIMINISHING TO 15 MPH IN THE AFTERNOON. HIGHS
WILL BE IN THE MID 40S.
THE SURFACE HIGH WILL MOVE OVERHEAD WEDNESDAY NIGHT...PRODUCING
IDEAL RADIATIONAL CONDITIONS AND A COLDER OVERNIGHT PERIOD...
TEMPERATURE-WISE...WITH LOWS SOLIDLY IN THE MID 20S. OUTLYING AREAS
ARE APT TO SEE SOME LOW 20S READINGS AROUND SUNRISE. THESE LOW
TEMPERATURES WILL THREATEN CROPS THAT WERE PLANTED EARLY AS WELL AS
FRUIT TREES AND STRAWBERRIES THAT ARE IN BLOOM. ON THE POSITIVE
SIDE...THERE WILL BE NO APPRECIABLE WIND CHILL DUE TO THE CALM
WINDS. -MLM
THURSDAY: THURSDAY WILL START OUT WITH A STRONG 1035 MB SURFACE HIGH
PRESSURE CENTERED OVER COASTAL NC. WHILE THE DAY MIGHT START OUT
FAIRLY CLOUD FREE...EXPECT MID AND UPPER LEVEL CLOUDS TO QUICKLY
SHROUD MOST OF THE CWA BY LATE MORNING/EARLY AFTERNOON. DESPITE THE
CLOUD COVER...NO PRECIPITATION IS EXPECTED. WHILE GUIDANCE SUGGESTS
MAX TEMPERATURES IN THE UPPER 50S...THICKNESSES AND CLOUD COVER
SUGGEST COOLER TEMPS...FOR NOW WILL GO MID 50S NORTH TO UPPER 50S IN
THE SOUTH. -ELLIS
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 240 AM TUESDAY...
THURSDAY NIGHT THROUGH SATURDAY NIGHT: THE FIRST HALF OF THE LONG
TERM IS SETTING UP TO BE A FAIRLY WET PERIOD WITH THE FIRST ACT
BEGINNING WITH AN IN-SITU DAMMING EVENT AS THE 1035 MB SURFACE HIGH
MOVES OUT INTO THE WESTERN ATLANTIC. ISENTROPIC LIFT HIGHLIGHTED ON
THE 290 K SURFACE SUPPORTS AT LEAST SOME LOW LEVEL CLOUDS MOVING
INTO CENTRAL NC WITH PERHAPS EVEN SOME VERY LIGHT PRECIPITATION.
OVERNIGHT LOWS IN TEH LOW TO MID 40S.
ON FRIDAY SURFACE LOW PRESSURE WILL MOVE THROUGH THE GREAT LAKES
WITH AN ATTENDANT COLD FRONT STRETCHING SOUTHWESTWARD. EARLY IN THE
DAY...MOISTURE TRANSPORT AND CONVERGENCE WILL INCREASE SIGNIFICANTLY
THROUGH THE DAY ON FRIDAY WITH PRECIPITABLE WATER VALUES RISING
ABOVE AN INCH BY FRIDAY AFTERNOON 1.25 INCHES BY EVENING. THE MAIN
PRE-FRONTAL PRECIPITATION WILL HOLD BACK ACROSS THE MOUNTAINS FRIDAY
MORNING AND ANY PRECIPITATION OCCURRING ACROSS CENTRAL NC WOULD BE
LIGHT AND ASSOCIATED MORE WITH MOISTURE CONVERGENCE IN THE SOUTHERLY
RETURN FLOW. THAT WILL CHANGE AFTER 18Z HOWEVER...WHEN PRECIP
OVERSPREADS MUCH OF THE CWA. MODEL FORECAST SOUNDINGS ARE VERY WET
THROUGH THE COLUMN WITH SOME BUT VERY WEAK INSTABILITY. WHILE BULK
SHEAR WILL BE AROUND 40 KTS...THE WEAK CAPE VALUES LOOK TO ONLY
SUPPORT SHOWERS BUT CAN NOT RULE OUT A FEW THUNDERSTORMS IN THE
EXTREME SOUTHEAST. THERE IS SOME UNCERTAINTY AS TO COVERAGE AND QPF
AMOUNTS AT THIS TIME BUT WILL KEEP A COUPLE TENTHS OF AN INCH
POSSIBLE BY THE END OF THE EVENING ON FRIDAY. TEMPERATURES IN THE
LOW 60S NW TO UPPER 60S SE. THE FRONT WILL HAVE TROUBLE GETTING
THROUGH THE AREA ON FRIDAY NIGHT AND AT THIS POINT LOOKS LIKE
CENTRAL NC WILL REMAIN IN THE WARM SECTOR AT LEAST INTO SATURDAY
MORNING. LOWS UPPER 40S TO MIDDLE 50S.
SATURDAY WILL CONTINUE TO BE WET AS THE FRONT LINGERS NORTHWEST OF
THE AREA. THIS WONT LAST FOREVER THOUGH AS THE UPPER TROUGH BEGINS
TO DIG INTO THE MISSISSIPPI VALLEY AND WILL EVENTUALLY GIVE THE
SUPPORT NEEDED TO PUSH THE FRONT THROUGH AND THE SYSTEM OUT TO SEA.
THE DETAILS OF HOW THIS WILL EVOLVE THOUGH REMAIN IN QUESTION BUT
ARE NOW COMING INTO BETTER AGREEMENT. BOTH MODELS NOW DEVELOP A
SOUTHERN STREAM WAVE WEST OF THE MOUNTAINS AND MOVE NORTH OF THE
AREA THROUGH THE MID ATLANTIC...PUSHED OUT TO SEA BY THE UPPER
TROUGH WHERE IT WILL LINK UP WITH A WEAKER WAVE OF LOW PRESSURE
COMING OUT OF THE GULF OF MEXICO AND UP THE EAST COAST. AN UPPER LOW
MOVES ACROSS NC BUT DOES NOT REALLY PHASE WITH THE LOW COMING UP THE
COAST. SATURDAY WILL BE WET AND OVERCAST WITH HIGHS IN THE MID TO
UPPER 60S. FORECAST SOUNDINGS SHOW MUCH BETTER INSTABILITY ON
SATURDAY THAN FOR FRIDAY WITH AS MUCH AS 800 J/KG IN THE SOUTHEAST
WITH 35-40 KTS OF BULK SHEAR MAKING THUNDERSTORMS A MUCH BETTER
POSSIBILITY FROM THE TRIANGLE SOUTH AND EASTWARD THAN ON FRIDAY
AFTERNOON. WILL INCLUDE THE CHANCE FOR THUNDER IN THE FORECAST FOR
SATURDAY EVENING WITH FURTHER DETAILS TO BE IRONED OUT IN THE COMING
DAYS. THE FRONT WILL CROSS THE AREA SATURDAY NIGHT WITH WINDS
SHIFTING FROM SOUTHWESTERLY TO NORTHERLY WITH PRECIPITATION ENDING
AROUND DAYBREAK SUNDAY MORNING. LOWS SATURDAY NIGHT LOW TO MID 40S.
SUNDAY THROUGH MONDAY: MUCH DRIER FOR SUNDAY AND MONDAY AS SURFACE
HIGH PRESSURE EXTENDS ACROSS THE EASTERN SEABOARD WITH RIDGING
ALOFT. MONDAY WILL START OUT COOL ON THE EASTERN SIDE OF THE SURFACE
HIGH WITH NORTHERLY WINDS BUT THESE WILL BECOME VARIABLE BY MONDAY
AFTERNOON WITH HIGH PRESSURE MOVING MORE DIRECTLY OVERHEAD AND THEN
EAST OF THE AREA. HIGHS MONDAY IN THE MIDDLE 60S. LOWS IN THE UPPER
30S TO LOW 40S. A WARMING TREND FOR MONDAY AS SOUTHERLY RETURN FLOW
TAKES OVER AND THICKNESSES INCREASE BACK INTO THE 1350S. THIS SHOULD
SUPPORT HIGHS IN THE UPPER 60S TO NEAR 70 DEGREES.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM/ELLIS
LONG TERM...ELLIS
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
226 AM EDT TUE MAR 25 2014
.SYNOPSIS...A COMPLEX LOW PRESSURE SYSTEM WILL RAPIDLY INTENSIFY
WHILE TRACKING UP THE CAROLINA AND MIDDLE ATLANTIC COASTS THROUGH
TONIGHT. MODIFIED ARCTIC HIGH PRESSURE WILL FOLLOW BEHIND THE SYSTEM
FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TUESDAY NIGHT/...
AS OF 1010 PM MONDAY...
THROUGH MID-MORNING TUESDAY... REGIONAL SURFACE ANALYSIS THIS
EVENING SHOWS WEAK HIGH PRESSURE JUST EAST OF THE DELMARVA... AN
INVERTED TROUGH EXTENDING UP THE APPALACHIANS...AND A WEAK LOW
FORMING EAST OF DAYTONA. ALOFT... RAOBS SHOW WESTERLY FLOW OVER THE
SOUTHEAST US AND A SHORTWAVE TROUGH MOVING INTO THE MID MS RIVER
VALLEY REGION. THIS LEAD SHORTWAVE WILL HELP DRIVE THE DEVELOPING
SURFACE LOW NORTHEAST INTO THE ATLANTIC TONIGHT AND EARLY TUESDAY.
MEANWHILE...A 125KT UPPER JET DIVING THROUGH THE CENTRAL PLAINS WILL
BEGIN TO AMPLIFY THE UPPER LEVEL FLOW LATE TONIGHT...LEADING TO A
SECONDARY SURFACE LOW EAST OF CAPE HATTERAS BY TUESDAY EVENING.
UPSTREAM THIS EVENING...PRECIP ASSOCIATED WITH THE LEAD SHORTWAVE IS
DRYING UP...BY EXPECT PRECIP TO REDEVELOP FROM THE SOUTHERN
APPALACHIANS TO THE BLUE RIDGE BY AROUND 08Z AS THE UPPER TROUGH
AMPLIFIES AND DCVA/HEIGHT FALLS BEGIN TO INCREASE. TO THE
SOUTHEAST... PRECIP WILL ALSO BREAK OUT WITH SLOWLY STRENGTHENING
LOW LEVEL WARM ADVECTION AND CYCLOGENESIS OVER THE SOUTH CAROLINA
COASTAL AREA...THOUGH MOST OF THE CONVECTION ALLOWING MODELS NOW
KEEP PRECIP SOUTHEAST OF SAMPSON AND WAYNE COUNTIES THROUGH 12Z.
WITH THE AFOREMENTIONED AREAS OF FORCING NOT LINKING UP UNTIL
TUESDAY AFTERNOON AS THE SYSTEM BEGINS TO LIFT AWAY FROM THE AREA
AND DEEPEN...MODELS CONTINUE SHOW SHOW RELATIVELY LIGHT QPF AMOUNTS
AROUND ONE TENTH OF AN INCH IN THE NORTHWEST AND SOUTHEAST PORTIONS
OF THE CWA PRIOR TO 15Z.
REGARDING THE CHANCE OF SNOW IN THE NORTHWEST PIEDMONT...THE NAM AND
GFS FORECAST SOUNDINGS STILL SHOW SIGNIFICANTLY DIFFERENT BOUNDARY
LAYER MOISTURE...WITH THE NAM SATURATING MUCH MORE RAPIDLY THAN THE
GFS. THE LATEST RAP APPEARS TO BE SOMEWHERE IN BETWEEN. IN ANY
CASE...WETBULB PROFILES CONTINUE TO SUPPORT THE POTENTIAL FOR BURSTS
OF SNOW WITH HEAVIER PRECIP RATES...WITH THE BEST CHANCE BETWEEN 10Z
AND 14Z.. WITH NEAR SURFACE TEMPERATURES AT OR A LITTLE ABOVE
FREEZING...AND TOP SOIL TEMPS IN THE LOW-MID 40S...ANY SNOW THAT
OCCURS WILL LIKELY MELT ON IMPACT. THE EXCEPTION TO THIS WILL BE
"IF" A BURST OF MODERATE TO HEAVY SNOW WERE TO OCCUR...QUICKLY
COATING GRASSY AREAS AND THE TOPS OF CARS.
AS THE BULK OF THE PRECIP TRANSITIONS TOWARD EASTERN NC AND TEMPS
WARM A FEW DEGREES...ANY LINGERING PRECIP OVER THE NORTHWEST AND
NORTHERN PIEDMONT WILL BECOME ALL RAIN BY MIDDAY. -SMITH
TUESDAY AFTERNOON...THE NORTHERN STREAM S/W WILL TAKE ON A NEGATIVE
TILT AS IT CROSSES THE MID ATLANTIC STATES. THIS WILL LEAD TO SFC
CYCLOGENESIS OFF OF HATTERAS BY LATE TUESDAY WITH RAPID DEEPENING
TUESDAY NIGHT AS IT LIFTS TO THE N-NE. THIS MOVEMENT WILL TAKE THE
BULK OF THE PRECIP AWAY FROM CENTRAL NC BY EARLY TUESDAY
EVENING..WITH CLEARING SKIES DURING THE EVENING HOURS.
THE DEEPENING LOW COUPLED WITH ANOTHER CANADIAN HIGH OVER THE MID MS
VALLEY WILL CREATE BLUSTERY NW WINDS ACROSS CENTRAL NC LATE TUESDAY
THROUGH TUESDAY NIGHT. EXPECT WIND GUSTS 20-25 MPH WELL INTO THE
NIGHT. THIS WIND WILL ALSO USHER ANOTHER BATCH OF COOL DRIER AIR
INTO CENTRAL NC. THE WIND COUPLED WITH COLD AIR WILL RESULT IN WIND
CHILL VALUES IN THE UPPER TEENS TO AROUND 20 DEGREES LATE TUESDAY
NIGHT. MIN TEMPS MID 20S NW TO NEAR 30 SE. -WSS
&&
.SHORT TERM /WEDNESDAY AND WEDNESDAY NIGHT/...
AS OF 230 PM MONDAY...
UPPER TROF SHIFTS EAST AND THE COASTAL STORM LIFTS NORTHEAST QUICKLY
ON WEDNESDAY...WITH CLEAR SKIES AND THE PRESSURE GRADIENT RELAXING
AS THE MORNING PROGRESSES. COLD AIR ADVECTION WILL BE WELL
UNDERWAY...COMPLIMENTS OF SURFACE HIGH PRESSURE BUILDING IN FROM THE
WEST...WITH NORTHWEST WINDS 10 TO 15 MPH WITH GUSTS TO 25 MPH AROUND
DAYBREAK...WITH GUSTS DIMINISHING TO 15 MPH IN THE AFTERNOON. HIGHS
WILL BE IN THE MID 40S.
THE SURFACE HIGH WILL MOVE OVERHEAD WEDNESDAY NIGHT...PRODUCING
IDEAL RADIATIONAL CONDITIONS AND A COLDER OVERNIGHT PERIOD...
TEMPERATURE-WISE...WITH LOWS SOLIDLY IN THE MID 20S. OUTLYING AREAS
ARE APT TO SEE SOME LOW 20S READINGS AROUND SUNRISE. THESE LOW
TEMPERATURES WILL THREATEN CROPS THAT WERE PLANTED EARLY AS WELL AS
FRUIT TREES AND STRAWBERRIES THAT ARE IN BLOOM. ON THE POSITIVE
SIDE...THERE WILL BE NO APPRECIABLE WIND CHILL DUE TO THE CALM WINDS.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 230 PM MONDAY...
SOME WELCOME MODERATION IN TEMPERATURES IS ON TAP AS WE HEAD INTO
LATE WEEK AS THE SURFACE HIGH PRESSURE EDGES OFFSHORE AND A LOW
AMPLITUDE SHORT WAVE RIDGE TRANSLATES ACROSS THE AREA THURSDAY. THE
RESULTING SOUTHERLY RETURN FLOW AND SUNSHINE WILL ALLOW HIGHS TO
REACH THE MID TO UPPER 50S.
LOW LEVEL MOISTURE WILL BE RISING QUICKLY THURSDAY NIGHT AS DEW
POINTS CLIMB THROUGH THE 30S OVERNIGHT. THIS WILL RESULT IN
ISENTROPIC LIFT...WITH OVERCAST SKIES AND POSSIBLY SOME LIGHT RAIN
IN THE WEST BY FRIDAY MORNING. MINS WILL BE CORRESPONDINGLY MILDER
DUE TO THE SOUTHERLY FLOW AND DEVELOPING LOW CLOUDINESS...WITH MINS
FROM 40 TO 45.
UP TO THIS POINT THE MODELS HAVE BEEN IN RELATIVE AGREEMENT...
ESPECIALLY IN THE SENSIBLE WEATHER IMPACTS OVER CENTRAL NC THROUGH
FRIDAY...WITH BOTH ECM AND GFS DEPICTING A SURFACE LOW PRESSURE AREA
LIFTING INTO THE GREAT LAKES THURSDAY NIGHT WITH THE TRAILING COLD
FRONT EDGING EAST TOWARDS THE AREA FRIDAY. GFS IS HOLDING ONTO THE
IDEA OF DEVELOPING A TRAILING SOUTHERN STREAM SHORT WAVE INTO A
SECOND LOW PRESSURE AREA WHICH TRAILS THE INITIAL LOW
NORTHEAST...AND DELAYING THE FRONTAL PASSAGE UNTIL SATURDAY NIGHT.
MEANWHILE...THE ECM MAINTAINS A PROGRESSIVE SYSTEM WITH A CLEANER
SURFACE COLD FRONTAL PASSAGE FRIDAY NIGHT OR EARLY SATURDAY.
ONGOING FORECAST TRENDS ARE BASED ON THE FASTER ECM SOLUTION AND
WILL MAINTAIN THIS TREND PENDING A CLEARER SOLUTION HOPEFULLY TO
BECOME EVIDENT IN SUBSEQUENT RUNS. THUS WILL HAVE HIGH CHANCE POPS
FRIDAY NIGHT AND SATURDAY...WITH DRYING SATURDAY NIGHT. HIGHS FRIDAY
SHOULD BE AFFECTED BY THE IN-SITU EFFECTS OF THE ISENTROPICALLY
INDUCED LIGHT RAIN THURSDAY NIGHT...AND WILL UNDERCUT GUIDANCE BY
ABOUT 5 DEGREES IN THE CLIMATOLOGICALLY FAVORED AREA...GIVING US
NEAR 60 NORTHWEST TO 70 SOUTHEAST. MILD TEMPS IN THE WARM SECTOR
FRIDAY NIGHT...50 TO 55...AND SATURDAY SHOULD BE MILD AS WELL...MID
TO UPPER 60S...WITH POST FRONTAL COLD AIR ADVECTION DELAYED UNTIL
SATURDAY NIGHT...EVEN ON THE FASTER ECM...WITH MINS SUNDAY MORNING
WITHIN A COUPLE OF DEGREES EITHER SIDE OF 40. ZONAL FLOW = HIGH AND
DRY FOR DAYS 6 AND 7...WITH SUNDAYS HIGHS A BIT BELOW NORMAL...LOW
TO MID 60S...WARMING TO THE UPPER 60S MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 225 AM SATURDAY...
INITIALLY VFR CONDITIONS IN A DRY...EARLY SPRING ARCTIC AIR
MASS...WILL YIELD TO RAPIDLY DEVELOPING AND LOWERING MID LEVEL
CEILINGS AND VIRGA THIS MORNING...AS A POTENT UPPER LEVEL
DISTURBANCE PIVOTS ACROSS THE APPALACHIANS TOWARD CENTRAL NC. THIS
PRECIPITATION ALOFT WILL STEADILY SATURATE THE LOW LEVELS...SUCH
THAT CONDITIONS WILL BECOME AT LEAST MVFR ACROSS ALL OF CENTRAL
NC...AND LIKELY IFR AT TRIAD TERMINALS AND KRWI. THE PRECIPITATION
WILL FALL INITIALLY AS SNOW OR A SNOW/RAIN MIX AT TRIAD TERMINALS
BETWEEN 12-16Z...WITH RAIN ELSEWHERE. THE DEEP MOIST AXIS AND
ASSOCIATED MAIN BAND OF PRECIPITATION WILL THEN MOVE NORTHEAST OF
OUR AREA AND PROVIDE FOR A RETURN TO VFR CONDITIONS...WITH A
DEVELOPING GUSTY NORTHWESTERLY WIND AS THE BOUNDARY LAYER
DEEPENS...THIS AFTERNOON. A BAND OR TWO OF MOSTLY VFR RAIN SHOWERS
WILL THEN DEVELOP AND ACCOMPANY ANOTHER POTENT UPPER LEVEL
DISTURBANCE FORECAST TO PIVOT ACROSS NC BETWEEN 18-00Z. HAVE
ACCOUNTED FOR THIS POTENTIAL WITH A MENTION OF VICINITY SHOWERS IN
THE TAFS AT THIS TIME. TEMPO GROUPS MAY BE ADDED LATER FOR THIS
POTENTIAL AS TIMING AND LOCATION BECOME CLEARER. CLEARING AND
STRENGTHENING NW WINDS IN THE 12-18 KT RANGE WITH GUSTS TO 25-30
KTS...WILL DEVELOP THIS EVENING...AND CONTINUE OVERNIGHT.
OUTLOOK: THE BLUSTERY CONDITIONS WILL ABATE AROUND MIDDAY-EARLY
AFTERNOON WEDNESDAY. RETURN FLOW MOISTURE WILL RESULT IN MVFR-IFR
STRATUS...AND AREAS OF DRIZZLE OR LIGHT RAIN AT TRIAD TERMINALS...
LATE THU NIGHT-EARLY FRI. THIS LOW CLOUD COVER AND RAIN WILL THEN
SPREAD EAST ACROSS THE REMAINDER OF CENTRAL NC WITH THE APPROACH OF
A FRONTAL SYSTEM FROM THE WEST...WITH MVFR OR LOW VFR CEILINGS...ON
FRI. PERIODS OF SUB-VFR CONDITIONS MAY THEN CONTINUE THROUGH SAT
NIGHT...AS A SECONDARY WAVE OF LOW PRESSURE DEVELOPS ALONG THE SLOW-
MOVING FRONT.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...MWS
NEAR TERM...WSS/SMITH
SHORT TERM...MLM
LONG TERM...MLM
AVIATION...MWS
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
138 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A CHILLY RAIN WILL OVERSPREAD THE AREA TODAY AS DEEPENING LOW
PRESSURE OFFSHORE TRACKS NORTHEAST OFF OUR COAST. THE RAIN WILL
TAPER OFF LATE TONIGHT FOLLOWED BY WINDY AND COLDER CONDITIONS
AS THE LOW DEEPENS AND CANADIAN HIGH PRESSURE BUILDS FROM THE
WEST. NEAR TO BELOW FREEZING TEMPERATURES ARE EXPECTED EARLY ON
WEDNESDAY AND AGAIN THURSDAY. A WARMING TREND WILL PREVAIL LATE
IN THE WEEK INTO NEXT WEEKEND...WITH A WEAK COLD FRONT POSSIBLY
CROSSING THE AREA EARLY ON SUNDAY. FAIR AND DRY EARLY NEXT WEEK
AS HIGH PRESSURE MOVES OVER THE AREA.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 130 AM TUESDAY...LOW PRESSURE WILL CONSOLIDATE ALONG THE
FLORIDA PENINSULA TONIGHT...EMERGING OFF THE EAST COAST OF FL BY
SUNRISE. NO APPRECIABLE INTENSIFICATION IS EXPECTED UNTIL THE
UPPER TROUGH AND SIGNIFICANT SHORTWAVE ENERGY REACHES THE SURFACE
FEATURE LATE TUE AND TUE NIGHT AND BY THAT TIME...THE CENTER OF
THE LOW WILL BE JUST MOVING N OF OUR LATITUDE. THICKER CLOUD COVER
RESIDES TO OUR S THIS EVE WITH MAINLY THIN CIRRUS ACROSS THE
EASTERN CAROLINAS. THIS THICKER CLOUD COVER WILL BEGIN TO ADVANCE
NORTHWARD... ESPECIALLY AFTER MIDNIGHT. EARLY THIS EVE...THE
NEAREST WET WEATHER IN THE FORM OF SHOWERS AND THUNDERSTORMS WERE
DOWN ACROSS THE GULF OF MEXICO AND FLORIDA PENINSULA. HOWEVER...AS
THE LOW CENTER CONSOLIDATES E OF FL...WE DO EXPECT PRECIPITATION
TO BEGIN DEVELOPING OFF THE SOUTHEAST COAST WITH A NORTHWARD
SPREAD INTO AT LEAST PORTIONS OF THE EASTERN CAROLINAS TOWARD
MORNING. WILL INCLUDE THE HIGHEST POPS...UP TO
CATEGORICAL...ACROSS OUR SOUTHERN ZONES OVERNIGHT WITH MUCH LOWER
POPS AS YOU MOVE NORTH. HOWEVER...POPS EVEN ACROSS THE NORTHERN
PORTIONS OF THE FORECAST AREA WILL TREND MUCH HIGHER TUE MORNING.
THE CHARACTER OF THE PRECIPITATION WILL BEST BE DESCRIBED AS A
CHILLY RAIN.
LOWS WILL BE REACHED PRIOR TO THE ARRIVAL OF THE THICKEST CLOUD
COVER AND ONSET OF STRONGER ONSHORE PUSH. WE EXPECT MOST AREAS WILL
FLAT LINE AROUND THE MIDNIGHT HOUR AND THEN HOLD STEADY IF NOT RISE
A FEW DEGREES AS THE MOISTURE CONTENT OF THE AIR BEGINS TO
SIGNIFICANTLY INCREASE. WE WILL CONTINUE TO CAP LOWS IN THE MID AND
UPPER 30S AND WE ARE NOT EXPECTING A FREEZE TONIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...LIGHT RAIN LIKELY ONGOING AT THE START OF THE
PERIOD...THE MAIN QUESTION AS TO THE INLAND EXTENT. LOW PRESSURE
WELL OFF THE COAST TO BE MOVING TO THE NORTHEAST AND JUST ON THE
BEGINNING OF A DEEPENING TREND. EARLY IN THE DAY THE AREA WILL STILL
BE IN SOME WARM AIR ADVECTION FOR LOW LEVEL ASCENT BUT INLAND
LOCATIONS WILL NOT HAVE AS DEEP OF A MOISTURE PROFILE...YET MAY
EXPERIENCE STRONGER MID LEVEL SUPPORT AS INITIAL VORT MOVES BY.
SIMILARLY LATER IN THE DAY THE DEEPEST MOISTURE WILL REMAIN ALONG
COAST/OFFSHORE WHILE EVEN STRONGER HEIGHT FALLS AND PVA IMPINGE UPON
WESTERN ZONES. OVERALL RAINFALL AMOUNTS LOOK TO BE LOW...GENERALLY A
QUARTER OF AN INCH OR LESS...HIGHEST EAST. LATER IN THE EVENING ALL
SIGNS POINT TO RAPID DRYING...THE MAIN VORT CENTER OF THE MID LEVEL
HAS CROSSED...THE LOW ACCELERATES TO THE NE AND BEGINS TO BOMB...AND
LOW LEVEL THERMAL ADVECTION TURNS COLD. THE RAPIDLY DEEPENING AND
GROWING LOW WILL KEEP A MODERATE GRADIENT UP ALL NIGHT LOCALLY
ADDING A CHILL TO THE ALREADY UNSEASONABLY COLD TEMPERATURES. IT HAS
ALSO CAST JUST ENOUGH UNCERTAINTY AS TO WHICH LOCATIONS GET BELOW
FREEZING AND FOR HOW LONG. AFTER COLLAB WITH SURROUNDING WFO`S HAVE
OPTED TO HOLD OFF ON A FREEZE WATCH AT THIS TIME. WITH THE CENTER OF
THE HIGH DRAWING IN ON WEDNESDAY WE WILL SEE AN ABATING TREND IN THE
CHILLY WIND BUT A SHALLOW MIXED BOUNDARY LAYER WILL PREVENT MUCH OF
THE TEMPERATURE RECOVERY ABOVE FROM REACHING THE SURFACE...AND SAID
TEMP RECOVERY LOOKS A LITTLE TOO BRISK ANYWAY. LOOKS LIKE MOST
PLACES WILL STRUGGLE TO HIT A HIGH OF ABOUT 50...WITH A FEW DEGREES
ADDED TO FAR SRN ZONES. WITH SUCH A COLD AIRMASS IN PLACE AND LIGHT
OR EVEN CALM WINDS WEDNESDAY NIGHT HAS LONG BEEN THE ONE OUR
AGRICULTURAL INTERESTS CONTINUE TO DREAD. LOWS WILL READILY DIP
BLOW FREEZING FOR ALL BUT THE BEACHES...AND COOL FASTER THAN TUESDAY
NIGHT DUE TO THE LIGHT WINDS. NRN ZONES WHERE THE MOST ACTIVE
GROWING IS ALREADY OCCURRING SHOULD GET INTO THE MID 20S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...UNSETTLED WEATHER EXPECTED LATE IN THE PERIOD
AHEAD OF A LATE WEEK COLD FRONT AND POTENTIAL SOUTHERN STREAM
SHORTWAVE. PERIOD WILL BEGIN WITH MODIFYING HIGH PRESSURE SHIFTING
OFFSHORE AND DEVELOPING RETURN FLOW. TEMPS ONCE AGAIN RUN BELOW
CLIMO THU BUT MUCH WARMER THAN PREVIOUS DAYS. SIGNIFICANT DRY AIR
WILL EXIST AND PRECIP IS NOT EXPECTED THROUGH THU NIGHT. WARM
ADVECTION CONTINUES FRI PUSHING TEMPS NEAR TO ABOVE CLIMO AND
INCREASES MOISTURE. SEA BREEZE CONVECTION AND DIURNAL INSTABILITY
SHOWERS ARE EXPECTED AND HAVE HELD ONTO INHERITED LOW CHC POP. POP
REMAINS ELEVATED FRI NIGHT INTO SAT WITH COLD FRONT EXPECTED TO
CROSS THE AREA. SPEED OF THE FRONT WILL IN PART DEPEND ON A WEAKER
TRAILING SHORTWAVE MOVING INTO THE TN VALLEY EARLY SAT. MEDIUM RANGE
GUIDANCE AND THE ENSEMBLES ARE SPLIT ON THE TIMING/STRENGTH OF THE
WAVE WHICH COULD LEAD TO POP LINGERING WELL INTO SAT AFTERNOON
ACROSS EASTERN AREAS.
MUCH DRIER AIR MASS BUILDS IN FOR THE START OF NEXT WEEK WITH COLD
ADVECTION DELAYED UNTIL SUN. COLD ADVECTION WILL BE ON THE WEAK SIDE
WITH TEMPS ENDING UP BELOW CLIMO SUN AND MON. DEEP DRY AIR AND
NORTHERLY FLOW WILL HELP KEEP REGION DRY FOR THE START OF NEXT WEEK.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 06Z...MID LEVEL CIGS ARE SPREADING ACROSS THE CWA TONIGHT AS
SURFACE LOW PRESSURE ORGANIZES OFF THE FLORIDA COAST. EARLIER
FORECAST APPEARS ON TRACK AS THE LATEST HRRR RUNS INDICATE RAIN WILL
SPREAD UP THE COAST FROM SOUTH TO NORTH EARLY THIS MORNING. HAVE
NUDGED THE TIMING OF PCPN BACK A BIT WITH THIS TAF ISSUANCE...BUT
STILL EXPECT KMYR/KCRE TO SEE -RA BEFORE 12Z. WITH THE OFFSHORE
TRACK OF THE LOW...EXPECT PCPN AND MVFR CIGS TO BE FOCUSED ALONG THE
COAST. HAVE INCLUDED TEMPO MVFR FOR THE COASTAL TERMS IN THE LATE
MORNING/EARLY AFTERNOON AS RAIN WILL HELP TO LOWER CIGS. E-NE WINDS
5-10 KTS THIS MORNING WILL BECOME NORTHWEST AFTER 18Z AS THE LOW
PROGRESSES FURTHER UP THE COAST. COULD SEE NORTHWEST WIND GUSTS OF
15-20 KTS BY LATE AFTERNOON/EARLY EVENING ON THE BACKSIDE OF THE
LOW. CONDITIONS WILL IMPROVE TO VFR FROM SOUTHWEST TO NORTHEAST THIS
EVENING...BECOMING VFR AT ALL SITES SHORTLY AFTER 00Z WEDNESDAY.
EXTENDED OUTLOOK...VFR ON WEDNESDAY AND THURSDAY. CHANCE OF SHOWERS
WITH TEMPO MVFR CONDITIONS POSSIBLE ON FRIDAY AND SATURDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 900 PM MONDAY...AS LOW PRESSURE CONSOLIDATES TO THE SOUTH OF
THE AREA OVERNIGHT AND HIGH PRESSURE RETREATS NORTHWARD AND
OFFSHORE...WE WILL BEGIN TO SEE THE PRESSURE GRADIENT TIGHTEN AND
THIS TREND WILL INCREASE IN BOTH RATE AND MAGNITUDE TUE AND TUE
NIGHT AS LOW PRESSURE STRENGTHENS...MOST RAPIDLY AS IT PUSHES N OF
OUR LATITUDE TUE NIGHT. WINDS AND SEAS WILL BE ON THE UPTREND AFTER
MIDNIGHT WITH SMALL CRAFT ADVISORY CONDITIONS DEVELOPING DURING TUE.
THE WIND DIRECTION TONIGHT WILL BE NE TO ENE...UP TO 15 TO 20 KT.
SEAS WILL BE 3 TO 4 FT...INCREASING UP TO 5 FT ACROSS THE OUTER
WATERS TOWARD MORNING.
SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM MONDAY...WILL RAISE SMALL CRAFT FOR NORTHERN ZONES
STARTING 12Z TUESDAY. WINDS WILL STILL BE ON THE RISE BUT THERE WILL
BE JUST ENOUGH SWELL ENERGY TO PUSH SEAS TO 4 TO 6 FT BY THE START
OF THE PERIOD. FROM THERE WIND AND SEAS WILL ONLY INCREASE BUT WAVE
SHADOWING WILL PROBABLY PRECLUDE ADVISORY FOR BRUNSWICK WATERS.
ADVISORY CONDITIONS MAY MATERIALIZE FURTHER SOUTH IN THE FORM OF
WIND AND SEAS FOR GTWON AND JUST WINDS FOR BRUNSWICK DUE TO WAVE
SHADOWING. THIS WILL BE DELAYED UNTIL TUESDAY NIGHT OR EVEN
WEDNESDAY SO HAVE HELD OFF ON FLAGS THERE FOR NOW. THIS WILL BE IN
RESPONSE TO THE LOW PRESSURE THAT PASSES BY ON TUESDAY...WHICH THEN
INTENSIFIES RAPIDLY AND GROWS IN SIZE ON WEDNESDAY AS IT
ACCELERATES TO THE NORTHEAST.
LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 300 PM MONDAY...LIGHT NORTHEAST FLOW WILL GRADUALLY VEER TO
SOUTHEAST THU AS HIGH PRESSURE SHIFTS OFF THE COAST. GRADIENT STARTS
TO BECOME MORE DEFINED THU NIGHT AND FRI WITH WINDS BECOMING
SOUTHERLY AND INCREASING TO A SOLID 15 KT THU NIGHT AND 15 TO 20 KT
FRI. COLD FRONT CROSSES THE WATERS EARLY SAT BUT LAGGING COLD
ADVECTION WILL KEEP LOW LEVEL FLOW SOUTHERLY. WEAK GRADIENT BEHIND
THE FRONT INITIALLY RESULTS IN WINDS 10 KT OR LESS INTO SAT
AFTERNOON. ONSET OF COLD ADVECTION LATE IN THE PERIOD KICKS
NORTHERLY FLOW TO A SOLID 20 KT BY THE END OF THE PERIOD. SEAS 2 TO
3 FT THU BUILD TO 3 TO 5 FT BY MIDDAY FRI AND 4 TO 6 FT FRI
AFTERNOON. SEAS DROP TO 3 TO 4 FT SAT IN RESPONSE TO THE REDUCTION
IN WIND SPEEDS. INCREASING NORTHERLY FLOW SAT NIGHT WILL BUILD SEAS
TO 3 TO 5 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 AM THIS MORNING TO 8 AM EDT
WEDNESDAY FOR AMZ250-252.
&&
$$
NEAR TERM...MJC/RJD
SHORT TERM...MBB
LONG TERM...III
AVIATION...MJC/BJR
AREA FORECAST DISCUSSION
NWS BISMARCK ND
954 PM CDT WED MAR 26 2014
.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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 718 PM CDT WED MAR 26 2014
VFR CIGS ARE EXPECTED OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. MVFR CIGS COULD DEVELOP FROM NORTH TO
SOUTH TONIGHT. HOWEVER...DEEP LAYER HIGH PRESSURE SHOULD KEEP LOW
CLOUDS FEW-SCT. FOR NOW KEPT ALL TAFS VFR AND INDICATED THE
POSSIBILITY OF MVFR CIGS WITH A SCT025 CLOUD GROUP.
FURTHERMORE...WINDS WILL INCREASE TONIGHT THROUGH THURSDAY OVER
KBIS-KJMS AS LOW PRESSURE DEEPENS ACROSS THE CENTRAL PLAINS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...WAA
LONG TERM...JV
AVIATION...TM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
718 PM CDT WED MAR 26 2014
.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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 718 PM CDT WED MAR 26 2014
VFR CIGS ARE EXPECTED OVER WESTERN AND CENTRAL NORTH DAKOTA
THROUGH THE TAF PERIOD. MVFR CIGS COULD DEVELOP FROM NORTH TO
SOUTH TONIGHT. HOWEVER...DEEP LAYER HIGH PRESSURE SHOULD KEEP LOW
CLOUDS FEW-SCT. FOR NOW KEPT ALL TAFS VFR AND INDICATED THE
POSSIBILITY OF MVFR CIGS WITH A SCT025 CLOUD GROUP.
FURTHERMORE...WINDS WILL INCREASE TONIGHT THROUGH THURSDAY OVER
KBIS-KJMS AS LOW PRESSURE DEEPENS ACROSS THE CENTRAL PLAINS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TM
SHORT TERM...WAA
LONG TERM...JV
AVIATION...TM
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
125 PM EDT TUE MAR 25 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS EAST THROUGH THE OHIO VALLEY
TODAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD WEST OF THE AREA
TONIGHT AND CROSS THE OHIO VALLEY ON WEDNESDAY. THE NEXT COLD
FRONT TO CROSS THE REGION WILL SEE RAIN AND MILD TEMPERATURES
OVERSPREAD THE OHIO VALLEY BEFORE IT PASSES ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT CURRENTLY PUSHING INTO NORTHWEST INDIANA WILL WORK
EAST ACROSS OUR AREA THROUGH THIS AFTERNOON. WE ARE ALREADY SEEING
FAIRLY WIDESPREAD SNOW SHOWER ACTIVITY ASSOCIATED WITH THIS BACK
ACROSS INDIANA. AS DAYTIME HEATING DEVELOPS...LOW LEVEL LAPSE RATES
WILL CONTINUE TO INCREASE THROUGH LATE MORNING/EARLY AFTERNOON.
THE 06Z NAM AND LATEST RAP RUNS ARE ALSO INDICATING A NARROW AXIS
OF WEAK ELEVATED INSTABILITIES PROGRESSING EAST ACROSS OUR AREA
THROUGH THIS AFTERNOON. THUS...EXPECT CONVECTIVE SNOW SHOWER
ACTIVITY TO BECOME EVEN MORE WIDESPREAD THROUGH LATE MORNING AND
INTO THIS AFTERNOON. THINK ALL AREAS WILL AT LEAST SEE SOME PCPN SO
WILL GO AHEAD AND BUMP UP POPS TO CATEGORICAL. WOULD EXPECT THE
POSSIBILITY FOR VISIBILITIES TO BRIEFLY DROP DOWN BELOW A QUARTER
OF A MILE IN THE HEAVIER SNOW SHOWERS. SOME QUICK DUSTING TO HALF
INCH ACCUMULATIONS WILL BE POSSIBLE WITH THESE HEAVIER SNOW
SHOWERS...PRIMARILY ON GRASSY AREAS AND ELEVATED SURFACES. ROAD
TEMPERATURES ARE CURRENTLY A FEW DEGREES ABOVE FREEZING ACROSS THE
AREA...SO WOULD EXPECT THE PRIMARY TRAVEL CONCERN TO BE THE LOWER
VISIBILITIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DROPPED LOW TEMPERATURES TONIGHT BY A FEW DEGREES WITH THE HIGH
BUILDING IN RAPIDLY FROM THE WEST AND A STRONG COLD PUSH. AM NOT
EXPECTING A LOT OF FRESH SNOW COVER OTHERWISE I WOULD HAVE CUT
LOWS EVEN FURTHER. MID TO UPPER TEENS SHOULD BE A FAIRLY UNIFORM
MIN TEMPERATURE TONIGHT OVER MUCH OF THE REGION AS SKIES CLEAR.
NORTH FLOW ON WEDNESDAY WILL COMPETE WITH SOME INCREASING HIGH
CLOUDS IN THE LATTER PART OF THE DAY AS THE AXIS OF HIGH PRESSURE
CROSSES THE REGION. FLOW WILL TURN SOUTH WEDNESDAY NIGHT AND
TEMPERATURES WILL THEN SEE A MARKED INCREASE FOR THE NEXT SEVERAL
PERIODS. MOISTURE WILL ALSO BE ON THE INCREASE THROUGH THURSDAY
AHEAD OF THE NEXT FROPA ON FRIDAY.
AS THE MOISTURE PULLS INTO THE REGION THURSDAY...THE THREAT FOR
SOME SHOWERS WILL INCREASE LATE IN THE DAY AND PARTICULARLY
OVERNIGHT IN NORTHWESTERN CWA...SPREADING EAST AS THE FRONT
APPROACHES. HAVE RAMPED UP THE POPS OVERNIGHT AS A STRONG LLJET
OF 50-60KT STREAMS GULF MOISTURE INTO THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WILL RAMP UP POPS TO LKLY WITH EXPECTED FROPA FRIDAY AFTN. WILL
MENTION A CHANCE OF THUNDER WITH MARGINAL INSTBY INDICATED AHD OF
THIS FRONT.
IN RETURN SOUTHERLY FLOW TEMPERATURES TO BE CLOSE TO NORMAL
THURSDAY...WITH HIGHS RANGING FROM THE LOWER 50S NW TO THE UPPER 50S
SE. ON THE WARM SIDE OF THIS SYSTEM...HIGHS ON FRIDAY TO RANGE FROM
THE MID 50S NW TO THE LOWER 60S SE.
MODEL DIFFERENCES EXISTS REGARDING THE DEVELOPMENT OF A SRN SECONDARY
SFC WAVE. ECMWF/CMC ARE MORE PROGRESSIVE WITH GFS DEVELOPING THIS
WAVE. WILL TREND FCST TOWARD MORE PROGRESSIVE SOLN AND ONLY LINGER A
CHANCE OF SHOWERS INTO FRIDAY EVENING WITH THE UPPER TROF LAGGING
ACRS THE REGION.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION PROVIDING DRY WEATHER
CONDITIONS AND COOLER TEMPERATURES. SATURDAYS HIGH TEMPERATURES TO
RANGE FROM UPPER 40S NORTHWEST TO THE MID 50S SOUTHEAST.
THIS HIGH TO QUICKLY SLIDE OFF TO THE EAST WITH A RETURN FLOW
DEVELOPING. TEMPERATURES TO WARM UP ABOVE NORMAL...WITH HIGHS FROM
THE UPPER 50S NORTHEAST TO THE LOWER 60S SOUTHWEST.
A FEW WAA SHOWERS WILL BE POSSIBLE NEXT MONDAY ESPECIALLY ACRS THE
NORTHWEST. HAVE LIMITED MENTION TO SLIGHT CHANCE CATEGORY AT THIS
TIME. TEMPERATURES TO CONTINUE TO WARM UP WITH HIGHS ON MONDAY FROM
THE MID 60S NW TO AROUND 70 SE.
&&
.AVIATION /17Z TUESDAY THROUGH SATURDAY/...
A COLD FRONT IS PUSHING EAST ACROSS OUR AREA EARLY THIS
AFTERNOON. CONVECTIVE SNOW SHOWERS ALONG AND JUST BEHIND THIS
FRONT WILL WORK THEIR WAY EAST ACROSS THE TAF SITES THROUGH MID TO
LATE AFTERNOON. VISIBILITIES WITHIN THESE SNOW SHOWERS MAY BRIEFLY
DROP TO BELOW A QUARTER OF A MILE ALONG WITH SOME IFR CIGS. AS THE
FRONT PASSES...WINDS WILL BECOME NORTHWESTERLY WITH GUSTS IN THE
25 TO 30 KNOT RANGE POSSIBLE THROUGH LATE AFTERNOON. HIGH PRESSURE
AND A DRIER AIRMASS WILL BEGIN TO BUILD IN TONIGHT THROUGH
WEDNESDAY...RESULTING IN IMPROVING CONDITIONS THROUGH THE
REMAINDER OF THE TAF PERIOD.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY LATE THURSDAY
NIGHT INTO FRIDAY ALONG WITH A CHANCE OF THUNDERSTORMS.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...JGL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
922 AM EDT TUE MAR 25 2014
.SYNOPSIS...
A COLD FRONT WILL CROSS EAST THROUGH THE OHIO VALLEY
TODAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD WEST OF THE AREA
TONIGHT AND CROSS THE OHIO VALLEY ON WEDNESDAY. THE NEXT COLD
FRONT TO CROSS THE REGION WILL SEE RAIN AND MILD TEMPERATURES
OVERSPREAD THE OHIO VALLEY BEFORE IT PASSES ON FRIDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A COLD FRONT CURRENTLY PUSHING INTO NORTHWEST INDIANA WILL WORK
EAST ACROSS OUR AREA THROUGH THIS AFTERNOON. WE ARE ALREADY SEEING
FAIRLY WIDESPREAD SNOW SHOWER ACTIVITY ASSOCIATED WITH THIS BACK
ACROSS INDIANA. AS DAYTIME HEATING DEVELOPS...LOW LEVEL LAPSE RATES
WILL CONTINUE TO INCREASE THROUGH LATE MORNING/EARLY AFTERNOON.
THE 06Z NAM AND LATEST RAP RUNS ARE ALSO INDICATING A NARROW AXIS
OF WEAK ELEVATED INSTABILITIES PROGRESSING EAST ACROSS OUR AREA
THROUGH THIS AFTERNOON. THUS...EXPECT CONVECTIVE SNOW SHOWER
ACTIVITY TO BECOME EVEN MORE WIDESPREAD THROUGH LATE MORNING AND
INTO THIS AFTERNOON. THINK ALL AREAS WILL AT LEAST SEE SOME PCPN SO
WILL GO AHEAD AND BUMP UP POPS TO CATEGORICAL. WOULD EXPECT THE
POSSIBILITY FOR VISIBILITIES TO BRIEFLY DROP DOWN BELOW A QUARTER
OF A MILE IN THE HEAVIER SNOW SHOWERS. SOME QUICK DUSTING TO HALF
INCH ACCUMULATIONS WILL BE POSSIBLE WITH THESE HEAVIER SNOW
SHOWERS...PRIMARILY ON GRASSY AREAS AND ELEVATED SURFACES. ROAD
TEMPERATURES ARE CURRENTLY A FEW DEGREES ABOVE FREEZING ACROSS THE
AREA...SO WOULD EXPECT THE PRIMARY TRAVEL CONCERN TO BE THE LOWER
VISIBILITIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY NIGHT/...
DROPPED LOW TEMPERATURES TONIGHT BY A FEW DEGREES WITH THE HIGH
BUILDING IN RAPIDLY FROM THE WEST AND A STRONG COLD PUSH. AM NOT
EXPECTING A LOT OF FRESH SNOW COVER OTHERWISE I WOULD HAVE CUT
LOWS EVEN FURTHER. MID TO UPPER TEENS SHOULD BE A FAIRLY UNIFORM
MIN TEMPERATURE TONIGHT OVER MUCH OF THE REGION AS SKIES CLEAR.
NORTH FLOW ON WEDNESDAY WILL COMPETE WITH SOME INCREASING HIGH
CLOUDS IN THE LATTER PART OF THE DAY AS THE AXIS OF HIGH PRESSURE
CROSSES THE REGION. FLOW WILL TURN SOUTH WEDNESDAY NIGHT AND
TEMPERATURES WILL THEN SEE A MARKED INCREASE FOR THE NEXT SEVERAL
PERIODS. MOISTURE WILL ALSO BE ON THE INCREASE THROUGH THURSDAY
AHEAD OF THE NEXT FROPA ON FRIDAY.
AS THE MOISTURE PULLS INTO THE REGION THURSDAY...THE THREAT FOR
SOME SHOWERS WILL INCREASE LATE IN THE DAY AND PARTICULARLY
OVERNIGHT IN NORTHWESTERN CWA...SPREADING EAST AS THE FRONT
APPROACHES. HAVE RAMPED UP THE POPS OVERNIGHT AS A STRONG LLJET
OF 50-60KT STREAMS GULF MOISTURE INTO THE REGION.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
WILL RAMP UP POPS TO LKLY WITH EXPECTED FROPA FRIDAY AFTN. WILL
MENTION A CHANCE OF THUNDER WITH MARGINAL INSTBY INDICATED AHD OF
THIS FRONT.
IN RETURN SOUTHERLY FLOW TEMPERATURES TO BE CLOSE TO NORMAL
THURSDAY...WITH HIGHS RANGING FROM THE LOWER 50S NW TO THE UPPER 50S
SE. ON THE WARM SIDE OF THIS SYSTEM...HIGHS ON FRIDAY TO RANGE FROM
THE MID 50S NW TO THE LOWER 60S SE.
MODEL DIFFERENCES EXISTS REGARDING THE DEVELOPMENT OF A SRN SECONDARY
SFC WAVE. ECMWF/CMC ARE MORE PROGRESSIVE WITH GFS DEVELOPING THIS
WAVE. WILL TREND FCST TOWARD MORE PROGRESSIVE SOLN AND ONLY LINGER A
CHANCE OF SHOWERS INTO FRIDAY EVENING WITH THE UPPER TROF LAGGING
ACRS THE REGION.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION PROVIDING DRY WEATHER
CONDITIONS AND COOLER TEMPERATURES. SATURDAYS HIGH TEMPERATURES TO
RANGE FROM UPPER 40S NORTHWEST TO THE MID 50S SOUTHEAST.
THIS HIGH TO QUICKLY SLIDE OFF TO THE EAST WITH A RETURN FLOW
DEVELOPING. TEMPERATURES TO WARM UP ABOVE NORMAL...WITH HIGHS FROM
THE UPPER 50S NORTHEAST TO THE LOWER 60S SOUTHWEST.
A FEW WAA SHOWERS WILL BE POSSIBLE NEXT MONDAY ESPECIALLY ACRS THE
NORTHWEST. HAVE LIMITED MENTION TO SLIGHT CHANCE CATEGORY AT THIS
TIME. TEMPERATURES TO CONTINUE TO WARM UP WITH HIGHS ON MONDAY FROM
THE MID 60S NW TO AROUND 70 SE.
&&
.AVIATION /13Z TUESDAY THROUGH SATURDAY/...
A SHARPENING H5 TROF WILL SWING ACROSS THE GREAT LAKES AND OHIO
THIS MORNING. AT THE SAME TIME...A SFC CDFNT WILL PUSH ACROSS THE TAFS
USHERING ANOTHER SHOT OF CAA. LOW LEVEL FRONTAL CONVERGENCE AND
INCREASING INSTABILITY IN THE CAA WILL PRODUCE SHSN. CIGS AND
VSBYS WILL LIKELY DROP INTO AT LEAST MVFR WITHIN THE SHSN.
TIGHTENING PRESSURE GRADIENT TODAY WILL INCREASING WINDS WITH
GUSTS TO AS MUCH AS 30 KNOTS.
NW FLOW OFF THE LAKES WILL KEEP VFR CIGS AND POSSIBLY A FLURRY
ACROSS THE TAFS INTO THE EVENING HOURS. BUILDING HIGH PRESSURE
SHOULD BEGIN TO BREAK UP THE CIGS FROM SW TO NE AFT 06Z.
OUTLOOK...MVFR CEILINGS AND VISIBILITIES LIKELY LATE THURSDAY NIGHT
INTO FRIDAY.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
KY...NONE.
IN...NONE.
&&
$$
SYNOPSIS...FRANKS
NEAR TERM...JGL
SHORT TERM...FRANKS
LONG TERM...AR
AVIATION...SITES
AREA FORECAST DISCUSSION
NWS NORMAN OK
719 PM CDT WED MAR 26 2014
.AVIATION...
CLOUDS ARE ON THE DECREASE IN SOUTHWEST OKLAHOMA AND WESTERN
NORTH TEXAS EARLY THIS EVENING. A RECENT HRRR RUN...BRINGS
SOME CLEARING CLOSE TO I-35 BY 2-3Z. WILL KEEP CEILINGS (MAINLY
MVFR) THROUGH THE OVERNIGHT HOURS IN CENTRAL/NORTH CENTRAL
OK...WITH A RETURN OF CLOUDS OVERNIGHT IN WESTERN OKLAHOMA.
AS WINDS VEER EARLY THURSDAY...CLOUDS WILL ERODE MOST AREAS.
SOUTHERLY WINDS WILL SHIFT TO THE WEST AND NORTHWEST BY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 403 PM CDT WED MAR 26 2014/
DISCUSSION...
RAIN SHOWERS...ASSOCIATED WITH A MID LEVEL VORT MAX...CONTINUE TO
MOVE NORTHEAST THIS AFTERNOON INTO PORTIONS OF SE KS AND EASTERN
OK. THE MOST SIGNIFICANT PRECIP WILL COME TO AN END BY EARLY THIS
EVENING AS THE WAVE EXITS THE REGION...BUT AN OVERNIGHT LLJ AND
SUBTLE ISENTROPIC ASCENT WILL SUPPORT SOME DRIZZLE ACROSS PORTIONS
OF CENTRAL AND SOUTHERN OK AFTER MIDNIGHT/BEFORE SUNRISE UNTIL THE
LOW LEVEL FLOW BEGINS TO VEER. WILL ALSO KEEP THE WIND ADVISORY IN
EFFECT THROUGH 06Z TONIGHT CONSIDERING THE PREVIOUSLY MENTIONED
LLJ AND PRESSURE GRADIENT IN PLACE. A DRYLINE/SFC TROUGH WILL THEN
MOVE ACROSS THE I35 CORRIDOR TOMORROW AFTERNOON AS A SECOND
SHORTWAVE TROUGH...CURRENTLY NOTICEABLE IN WV OVER THE NORTHERN
AZ/SOUTHERN NV BORDER...TRAVERSES SOUTHERN KS. A FEW STORMS MAY
DEVELOP ACROSS PORTIONS OF EXTREME SE OK TOMORROW WHERE ENOUGH LOW
LEVEL MOISTURE/INSTABILITY CAN HANG ON JUST AHEAD OF THIS
BOUNDARY. MID LEVEL LAPSE RATES AROUND 7.5 C/KM AND SUFFICIENT
DEEP LAYER SHEAR COULD SUPPORT SOME BRIEF HAIL ACROSS THIS REGION
DURING THE AFTERNOON HOURS IF STORMS MANAGE TO DEVELOP...BUT MOST
OF THE SEVERE MOIST CONVECTION APPEARS IT WILL REMAIN EAST OF OUR
FA AT THE MOMENT.
A WEAK COLD FRONT WILL ACCOMPANY THIS SECOND WAVE TOMORROW
EVE...AND STALL SOMEWHERE NEAR THE RED RIVER BY FRI AM BEFORE
ANOTHER SURGE OF COLD AIR PUSHES SOUTH FRI EVE WITH YET ANOTHER
MID LEVEL SHORTWAVE TROUGH CROSSING THE SOUTHERN PLAINS. WILL KEEP
THE FORECAST DRY FOR NOW WITH THIS WAVE GIVEN EXPECTED MOISTURE
PROFILES...ALTHOUGH SOME MID TO UPPER LEVEL CLOUDS WILL ACCOMPANY
IT. TEMPS WILL DROP INTO THE LOW 60S AND 70S FROM NORTH TO SOUTH
RESPECTIVELY FRIDAY BEHIND THIS SECONDARY FRONT. A SFC RIDGE
OVERHEAD SAT...COMBINED WITH CLEAR SKIES AND DRY BOUNDARY LAYER
CONDITIONS...WILL RESULT IN UNSEASONABLY COLD MORNING LOWS SAT.
THE LOW LEVEL FLOW WILL THEN SLOWLY BECOME SOUTHERLY ACROSS MUCH
OF THE FA BY SAT AFTERNOON AS THIS HIGH MOVES EAST AND A LEE
TROUGH DEVELOPS. SOME LOW LEVEL MOISTURE RETURN IS EXPECTED
THROUGH THE WEEKEND BEFORE ANOTHER WEAK COLD FRONT MOVES THROUGH
MON NIGHT AS A VORT MAX CROSSES THE CENTRAL PLAINS AND ENTERS THE
MIDWEST. WILL KEEP LOW CHANCE POPS ACROSS THE EXTREME NORTH WITH
THIS WAVE. HIGHER POPS WILL THEN RETURN TO SOME OF THE (THE
EASTERN) FA BY MID NEXT WEEK AS LOW LEVEL MOISTURE SURGES
NORTHWARD AND ANOTHER COLD FRONT IMPACTS THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 76 43 64 / 30 10 0 10
HOBART OK 52 77 41 64 / 10 0 0 0
WICHITA FALLS TX 55 83 46 73 / 20 0 0 0
GAGE OK 50 72 34 63 / 0 0 0 0
PONCA CITY OK 51 73 37 61 / 20 10 0 10
DURANT OK 51 78 51 73 / 30 20 10 10
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WIND ADVISORY UNTIL 1 AM CDT THURSDAY FOR OKZ004>031-033>040-044-
045.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
EVENING FOR OKZ014-016-021-022-033>038-044.
TX...WIND ADVISORY UNTIL 1 AM CDT THURSDAY FOR TXZ083>090.
FIRE WEATHER WATCH FROM THURSDAY MORNING THROUGH THURSDAY
EVENING FOR TXZ083>090.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
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.
&&
$$
21
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
340 PM CDT TUE MAR 25 2014
.SHORT TERM (TONIGHT THROUGH WEDNESDAY NIGHT)...SURFACE HIGH
PRESSURE WILL BE EAST OF THE REGION...OVER THE OZARKS BY THIS
EVENING. LOW LEVEL EASTERLY FLOW WILL BECOME ESTABLISHED AS A
RESULT AND MOISTURE WILL BEGIN TO INCREASE WITH PW VALUES AROUND
1.4 INCHES BY 12Z WEDNESDAY. UPPER DISTURBANCE CURRENTLY OVER THE
CA/AZ BORDER WILL MOVE EASTWARD TONIGHT AND INTO TEXAS ON
WEDNESDAY. UPPER TROUGH COMBINED WITH JET OVER THE AREA WILL LEAD
TO INCREASED CHANCES OF SHOWERS AND THUNDERSTORMS BEGINNING
TONIGHT AND CONTINUING INTO WEDNESDAY. POPS WILL INCREASE FIRST
OVER THE RIO GRANDE PLAINS LATER THIS EVENING AND SPREAD EASTWARD
TONIGHT. THIS IS SUPPORTED BY THE LATEST RUNS OF THE HRRR AS
SHOWERS MOVE OUT OF MEXICO. GREATER CHANCES FOR RAIN WILL THEN
SHIFT TO THE EAST/NORTHEAST PARTS (60 TO 70 POPS) OF THE REGION ON
WEDNESDAY AS UPPER TROUGH SWINGS THROUGH. CLOUD COVER AND
INCREASED RAIN CHANCES WILL KEEP TEMPS MOSTLY IN THE 60S ON
WEDNESDAY...WITH A FEW 70S FROM THE RIO GRANDE PLAINS TO EXTREME
SOUTHERN COASTAL BEND. RAIN CHANCES WILL PERSIST INTO WEDNESDAY
NIGHT AS SUFFICIENT MOISTURE REMAINS OVER THE REGION. MUCH WARMER
OVERNIGHT LOWS IN THE 60S CAN BE EXPECTED DUE TO THE MOSTLY CLOUDY
TO OVERCAST SKIES.
&&
.MARINE...STRONG ONSHORE FLOW WILL DEVELOP TONIGHT OVER THE GULF
WATERS...WITH SEAS BEGINNING TO BUILD AS WELL. WINDS WILL INCREASE
BETWEEN 20 AND 25 KNOTS OVER THE NEARSHORE WATERS...AND AROUND 25
KNOTS OVER THE OFFSHORE WATERS ON WEDNESDAY. SEAS WILL RANGE FROM
7 TO 9 FEET OVER THE NEARSHORE WATERS WITH 8 TO 10 FEET OVER THE
OFFSHORE WATERS. SMALL CRAFT ADVISORY CONDITIONS WILL PERSIST INTO
THURSDAY AS WINDS AND SEAS WILL BE SLOW TO DIMINISH.
&&
.LONG TERM (THURSDAY THROUGH MONDAY)...MAIN ACTIVITY IN LONG TERM IS
IN THE FIRST PERIODS WITH LINGERING MOISTURE IN NORTHEAST ZONES ON
THURSDAY. UPPER LEVEL JET REMAINS OVER THE REGION...THOUGH GFS HAS
WEAKENED IT QUITE A BIT. NAM SHOWS BEST UPPER LEVEL DIVERGENCE...AND
ALSO SHOWS STRONGER SHORT WAVE PUSHING THROUGH THE REGION ON
THURSDAY. MAIN CONCERN FOR PRECIP IS TIMING OF ALL THE INGREDIENTS.
BEST CAPE IS LATE AFTERNOON...BUT INDICATIONS ARE THAT MOISTURE
SHOULD BE MOVING OUT QUICKLY IN THE LATE AFTERNOON. HAVE KEPT A MAX
40 POP IN FAR NORTHEAST ZONES. IF STORMS DO DEVELOP COULD SEE SOME
STRONG STORMS WITH SUFFICIENT UPPER LEVEL SUPPORT AND GOOD CAPE.
BEYOND THAT...FORECAST GETS PRETTY QUIET. HAVE DRY LINE MOVING INTO
AREA THURSDAY...AND AGAIN ON FRIDAY WITH TEMPERATURES WEST OF IT
INTO THE UPPER 80S AND LOWER 90S. EAST IS A BIT COOLER. GFS STARTING
TO INDICATE PRECIP POTENTIAL FOR FRIDAY AFTERNOON...BUT NOT SOLD ON
THE MOISTURE RETURN THAT QUICKLY. HAVE KEPT JUST A SILENT 10 POP FOR
NOW...BUT IF THIS REMAINS CONSISTENT...AND IS INDICATED IN OTHER
MODELS MAY NEED TO ADD SLIGHT CHANCE POPS DOWN THE ROAD. COLD FRONT
PUSHES THROUGH FRIDAY NIGHT TO EARLY SATURDAY MORNING...BUT LOOKS
QUITE WEAK. NOT EXPECTING ANY PRECIP ASSOCIATED WITH IT...AND
TEMPERATURES WONT COOL MUCH. GRADUAL INCREASE IN MOISTURE IS
EXPECTED BY EARLY NEXT WEEK...BUT NO MENTIONABLE POPS AT THIS TIME.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 58 69 67 81 67 / 20 60 30 20 10
VICTORIA 52 65 63 79 65 / 10 70 40 40 10
LAREDO 59 73 68 92 69 / 40 30 20 10 10
ALICE 56 70 65 87 66 / 30 50 30 20 10
ROCKPORT 60 69 67 70 68 / 20 60 30 20 10
COTULLA 56 69 64 87 64 / 30 40 20 10 10
KINGSVILLE 58 70 66 84 67 / 30 50 30 20 10
NAVY CORPUS 61 70 67 76 67 / 20 60 30 20 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 1 AM WEDNESDAY TO 7 AM CDT THURSDAY
FOR THE FOLLOWING ZONES: COASTAL WATERS FROM BAFFIN BAY TO
PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM PORT ARANSAS
TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 7 AM CDT THURSDAY
FOR THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT
ARANSAS FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO
MATAGORDA SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
TB/78...SHORT TERM
PZ/83...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS PORTLAND OR
255 PM PDT TUE MAR 25 2013
UPDATED TO INCLUDE WIND ADVISORY HAZARDS
.SYNOPSIS...A DEEP UPPER LEVEL LOW OFFSHORE WILL PUSH A SECONDARY
FRONT THROUGH TODAY. THIS WILL BRING A ROUND OF SHOWERS WITH EVEN
SOME ISOLATED THUNDERSTORMS. SNOW LEVELS LOWER TO THE CASCADE PASSES
AND BELOW TONIGHT. COOL UNSETTLED WEATHER WILL CONTINUE THROUGH
THURSDAY AS THE UPPER LOW LINGERS NEARBY. A MORE ORGANIZED PACIFIC
FRONTAL SYSTEM IS EXPECTED BY THURSDAY NIGHT OR FRIDAY...LIKELY
BRINGING PERIODS OF HEAVIER RAIN INTO THE WEEKEND.
&&
.SHORT TERM...TONIGHT THROUGH FRIDAY...
A FEW LIGHTNING STRIKES FROM CAPE BLANCO TO NORTH BEND...TRACKING
NICELY ALONG A DRY PUNCH IN WATER VAPOR SATELLITE IMAGERY HAVE SPREAD
INLAND WHERE THUNDER HAS BEEN REPORTED/OBSERVED VIA LIGHTNING
NETWORKS IN THE CENTRAL/SOUTH VALLEY AND INTO THE FOOTHILLS. THIS
AXIS LINES UP WITH ABOUT 100 J/KG MOST UNSTABLE CAPE FROM THE
RAP...AND THIS AREA CURRENTLY EXTENDS INLAND THROUGH WILLAMETTE
VALLEY. EXPECT ACTIVITY TO SHIFT NORTH WHERE SUNBREAKS ALLOWED FOR
ADDITIONAL HEATING AND THESE AREAS REMAIN NORTH OF THE OCCLUDED
FRONTAL BOUNDARY. EXPECT ACTIVITY TO EASE THIS EVENING BEHIND THE
FRONT. ALONG THE COLD/OCCLUDED FRONT TEMPS ARE DROPPING BACK INTO
THE 40S/LOW 50S WITH A WIND SHIFT TO WSW AND SOME STABILIZATION. IT
WILL REMAIN BREEZY IN THE VALLEY THIS AFTERNOON WITH GUSTS EVEN TO
40 MPH DUE TO GOOD LOW LEVEL MIXING AND A STRONG LOW LEVEL WIND
FIELD...WITH PEAK WIND GUSTS TO 45-50 MPH AT THE COAST. SOME OF
THESE WINDS WILL BE ENHANCED BY CONVECTIVE DOWNDRAFTS SUCH THAT
SMALL BRANCHES/LIMBS MAY COME DOWN. THE UPPER WAVE AND ASSOCIATED
SURFACE LOW OFF THE WA COAST WILL CONTINUE TO PASS OFF TO THE NORTH
AND WILL EASE THE WINDS THIS EVENING AND SHOWER ACTIVITY TONIGHT.
SNOW ACCUMULATIONS ARE NOT EXPECTED AT THE PASSES UNTIL THIS EVENING
OR TONIGHT ONCE THE AFOREMENTIONED OCCLUDED/COLD FRONT PUSHES
THROUGH...POSSIBLY BRINGING A FEW INCHES BY DAYBREAK WEDNESDAY WITH
THE SNOW LEVEL DROPPING TO OR BELOW THE PASSES. QPF IS NOT ALL THAT
IMPRESSIVE...AND OROGRAPHICS ARE WEAK...SO JUST EXPECT 2-4 INCHES OF
SNOW AT MOST TONIGHT...WITH THE HIGHER ACCUMULATIONS ABOVE THE
PASSES. THIS WILL BE THE TREND WITH EACH SUBSEQUENT SHOWERY SYSTEM IN
THE SHORT TERM...A FEW INCHES OF ACCUMULATION AT A TIME THROUGH
THURSDAY...WITH MAYBE 6-12 INCHES FOR THE HIGHER CASCADE ELEVATIONS
THROUGH THIS TIME.
EXPECT MAYBE BIT OF LULL IN PRECIPITATION LATER THIS EVENING INTO THE
EARLY MORNING HOURS...BUT LOOKING UPSTREAM THERE ARE QUITE A BIT OF
SHOWER ACTIVITY OUT OVER THE PACIFIC. ANOTHER SHORT WAVE TROUGH
ROUNDING THE BASE OF THE CLOSED OFFSHORE LOW APPROACHES LATE TONIGHT
INTO WEDNESDAY MORNING...FOLLOWED BY THE CORE OF THE PARENT UPPER LOW
ON WEDNESDAY EVENING INTO EARLY THURSDAY. THERE IS ANOTHER SURFACE
LOW THAT WILL BE WEAKENING AS IT APPROACHES THE COAST WHICH WILL
BRING SOME BREEZES BUT NOT AS WINDY AS TODAY.
WHILE THERE IS A PERIOD OF UPPER RIDGING BEHIND THE UPPER
LOW...ANOTHER UPPER LOW WILL QUICKLY TAKE THE PLACE OF THE PREVIOUS
ONE. MOIST SW LOW LEVEL WARM ADVECTION AHEAD OF THIS LOW KEEPS LIFT
OVER THE AREA AHEAD OF A WARM FRONTAL FEATURE THURSDAY NIGHT...THEN A
TRAILING COLD FRONTAL BOUNDARY FRIDAY. THIS SYSTEM LOOKS PRETTY
WET...AND WITH SOME AMPLIFICATION OF THE UPPER FLOW...THE BOUNDARY GETS
HUNG UP A BIT INTO FRIDAY NIGHT AS ADDITIONAL WAVES IN SOUTHWEST FLOW
TRACK TOWARD THE AREA. THIS SYSTEM HAD ITS ORIGINS IN THE FAR WEST
PACIFIC ABOUT A WEEK AGO PICKING UP SOME SUBTROPICAL MOISTURE IT
LOOKS LIKE IT IS CARRY THAT EAST IN AN ORGANIZING ATMOSPHERIC RIVER
OF MOISTURE AS ITS NOSE APPROACHES 160W...SOMETHING THAT WILL HAVE
TO WATCHED FOR LATER IN THE WEEK. SOME RIVERS ARE FORECAST TO GET TO
BANKFULL AT THIS TIME...ALOT CONTINGENT ON RAINS RECEIVED IN SHOWERS
BEFOREHAND. EVENTUALLY SOME OF THE ENERGY SPLITS OFF TO THE
SOUTH...SEEN ON BOTH THE GFS/ECMWF...TO ALLOW THE BAROCLINIC ZONE TO
DRIFT SOUTHWARD TO MITIGATE ANY ADDITIONAL CONCERNS. /KMD
.LONG TERM...FRIDAY NIGHT THROUGH TUESDAY...
EXPECT LITTLE CHANGE IN THE OVERALL WEATHER PATTERN OVER THE EXTENDED
FCST PERIOD. A SERIES OF UPPER LEVEL TROUGHS WILL KEEP COOL AND WET
WEATHER CONTINUING THROUGH THE WEEKEND AND THE FIRST HALF OF NEXT
WEEK. A SIGNIFICANT SYSTEM LOOKS LIKE IT WILL BRING MODERATE
PRECIPITATION TO THE REGION FRI NIGHT...BUT THE LATEST MODEL CYCLE
CONTINUES TO KEEP THE HEAVIEST QPF FOCUSED OVER N CALIFORNIA AND S
OREGON. AFTER THIS FRONT PUSHES THROUGH...DO NOT CURRENTLY SEE ANY
MAJOR SYSTEMS THROUGH EARLY NEXT WEEK. BUT THERE WILL PLENTY OF
CHANCES FOR LIGHT RAIN AND MOUNTAIN SNOW. EXPECT TEMPERATURES TO RUN
ABOUT 5 TO 7 DEGREES BELOW NORMAL OVER THE LONG TERM PERIOD. PYLE
&&
.AVIATION...FLIGHT CONDITIONS REMAIN GENERALLY VFR AS OF
21Z ACROSS THE REGION AS THE COLD FRONT CONTINUES TO PUSH INLAND.
EXPECT PRIMARILY VFR CONDITIONS THROUGH WED...THOUGH MVFR LIKELY
IN ANY HEAVIER SHOWERS TONIGHT. ALSO CANNOT RULE OUT SOME
THUNDERSTORMS THROUGH THIS EVENING...THOUGH SHOULD REMAIN
ISOLATED. S WINDS REMAIN GUSTY BOTH ACROSS THE COASTAL AREAS AND
INLAND...WITH GUSTS 30-40 KT THROUGHOUT THE AREA THIS AFTERNOON.
THESE WILL CONTINUE THROUGH THIS EVENING BEFORE EASING TONIGHT.
WINDS AND LOWER FLIGHT CONDITIONS LIKELY TO LAST A BIT LONGER AT
THE COAST...ESPECIALLY AROUND KONP. LINGERING SHOWERS WILL REMAIN
TONIGHT THROUGH WED.
KPDX AND APPROACHES...EXPECT GENERALLY VFR TO PREVAIL THIS
EVENING...THOUGH MVFR CONDITIONS LIKELY UNDER ANY HEAVIER RAIN
SHOWERS. SOME ISOLATED THUNDERSTORMS POSSIBLE THROUGH THE
EVENING...THOUGH NOT ENOUGH CONFIDENCE TO INCLUDE IN TAF. EXPECT
CONTINUED SHOWERS UNDER VFR THROUGH WED. CULLEN
&&
.MARINE...THE COLD FRONT CONTINUES TO PUSH ITS WAY INLAND WITH
GUSTY WINDS ACROSS THE WATERS. THE AIR MASS REMAINS UNSTABLE
BEHIND THE FRONT AND IT IS POSSIBLE TO SEE SOME THUNDERSTORMS
DEVELOP THROUGH THE EARLY EVENING HOURS OVER THE WATERS. S WINDS
HAVE GUSTED TO NEAR 40 KT AT BUOY 29 MUCH OF THE DAY...AND WINDS
CONTINUE TO GUST NEAR GALE STRENGTH ACROSS BUOY 50. WINDS WILL
REMAIN STRONG THROUGH THE EVENING...BEFORE TURNING SW AND
BEGINNING TO EASE SLIGHTLY. HOWEVER...EXPECT GUSTS TO DECREASE TO
20-25 KT BY EARLY WED MORNING. HOWEVER...A SERIES OF DISTURBANCES
WILL MOVE ACROSS THE WATERS TO BRING PERIODS OF SMALL CRAFT
ADVISORY WINDS THROUGH THE END OF THE WEEK.
SEAS ARE CURRENTLY 11 TO 13 FT ACROSS THE WATERS. GIVEN
OBSERVATIONS FURTHER OFFSHORE...STILL THINK A PEAK NEAR 14 FT
LATER TODAY IS REASONABLE TO EXPECT. SEAS WILL SLOWLY BUT SLIGHTLY
SUBSIDE BACK TO NEAR 10 FT BY TOMORROW AFTERNOON. A BRIEF DROP TO
9 FT IS POSSIBLE...BUT SEAS WILL REBUILD TO NEAR 11 FT BY WED
NIGHT AS THE NEXT SWELL ARRIVES. EXPECT SEAS TO REMAIN IN THE 9 TO
12 FT RANGE THROUGH THE END OF THE WEEK. CULLEN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WIND ADVISORY FOR THE CENTRAL AND NORTH WILLAMETTE VALLEY AND PORTLAND
METRO AREA UNTIL 7 PM PDT.
WA...WIND ADVISORY FOR CLARK COUNTY AND THE VANCOUVER METRO AREA UNTIL 7 PM
PDT.
PZ...GALE WARNING UNTIL 9 PM PDT THIS EVENING FOR COASTAL WATERS
FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 3 PM
PDT WEDNESDAY.
&&
$$
MORE WEATHER INFORMATION ONLINE AT...
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA..
Area Forecast Discussion
National Weather Service Spokane WA
240 PM PDT TUE MAR 25 2014
.SYNOPSIS...A showery and unsettled spring time weather pattern
will persist through Thursday. The unsettled weather will bring a
chance for thunderstorms beginning this afternoon and evening and
repeating on Wednesday and Thursday. Temperatures will remain
above normal today and cool to near normal or slightly below
through the rest of the week. Friday into the weekend a warm wet
weather system is expected to bring widespread rain and high
mountain snow to the region.
&&
.DISCUSSION...
Tonight and Wednesday: Low pressure in the Gulf of
Alaska will push through an occluded front late this afternoon
through this evening. The back edge of this front is currently
beginning to push into the Cascade Mtns at 2:00 PM this afternoon.
There has been very little in the way of shower development east
of the Cascade Mtns ahead of the front. Radar returns have been
weak and cloud ceilings have generally been above 6-9 kft agl.
With dew point temps still in the mid 20s across much of the
region, there is still some moistening up that needs to be done
before we see any appreciable precip reaching the surface. I
scaled back the chances for precip across much of the region.
Models are still showing some shallow instability across southeast
WA and into the Central Panhandle Mtns. This will be our best bet
for showers to develop later today into this evening with the
front. This instability looks to be too weak for thunderstorms and
have been removed from the forecast. The only area where we might
see some thunderstorms this afternoon and evening will be along
the Cascade crest as the upper level cold pool shifts over head
and produces some deeper instability; however, my confidence for
thunderstorms here is also low. The HRRR model seems to have a
good handle on this system and it does show some isolated to
scattered showers developing behind the front into this evening.
Showers are expected to mainly be limited to the mountains as we
go through the overnight hours.
The upper level cold pool will be better positioned over the
region on Wednesday. This will allow for some afternoon showers to
redevelop over much of the region. There will be a marginal chance
for thunderstorms over the Northeast Mtns, into the ID Panhandle
and in the Northeast Blue Mtns. Instability parameters are not
very exciting with surface based CAPE values of 150 J/KG off the
GFS and 50-100 J/KG or so off of the NAM. I went ahead and left a
slight chance for thunderstorms, but a lack of dynamics will make
it difficult to get much in the way of deep convection going. Temps
on Wednesday will be right around normal for late March with highs in
the 50s for most valley locations. /SVH
Wednesday night through Friday...A closed low in the Gulf of
Alaska will begin to move inland Wednesday night and open up into
a wave on Thursday as it passes through the region. This will be
followed by building high pressure over the region Thursday night
and Friday. As such we expect showery precipitation Thursday and
widespread stratiform precipitation Friday.
Wednesday night and Thursday..As mentioned above the closed low
will move through the region...weaken...and open into a wave on
Thursday. This will increase the forcing for Thursday afternoon.
The atmosphere will remain conditionally unstable. 5h
temperatures are only -26 to -28C...but lapse rates increase to
7.0C to 8.0C by the afternoon. Lastly surface based capes are on
the order of 100-200 J/kg. There will be plenty of low and mid-
level moisture to work with. All this means a good chance of
showers any where out side of the basin with a slight chance of
late day thunderstorms..mainly across the eastern third of my
forecast area. Snow levels between 3.5k-4k feet will mean mainly
rain and graupel showers at the lower elevations with snow and
graupel in the higher mountains. Southwest winds 10 to 15 mph will
be common..but will likely become quite gusty with showers.
Temperatures will remain on the cool side of normal.
Thursday night and Friday...High pressure will build into the
region...and the mid and upper level flow will turn to the
southwest. this will tap into copious sub-tropical moisture.
PWATs increase to over a half inch which is roughly 160% of
normal. The warm front will be significant enough to over come
and Cascade shadow effect...so everyone will measure. Snow levels
increase to over 4k feet across the north to above 5k feet across
the south...so precip as mainly rain and high mountain snow.
Strong warm air advection will get mitigated by cloud cover and
precipitation...so kept temperatures close to persistence. /Tobin
Friday night through Monday: Active weather will continue across
the Inland NW through the weekend. A moist warm front will push
through the region Friday night, followed by a vigorous cold front
on Saturday with cooling, winds and convection. Snow levels will
be high, from 5-6k ft Friday day, but then fall into the valleys
by Saturday night. Post frontal westerly winds will become gusty
Saturday afternoon especially across the Columbia Basin with gusts
up to 35 mph. The GFS shows the best Iinstability along and
behind the front especially across the northern tier zones;
corresponding the the highest qpf. The cold pool aloft will settle
over the region with 500mb temperatures to -30C. Cape values look
to range from 200-400 j/kg supporting the mention of
thunderstorms, especially across northeast Washington and north
Idaho. Late Saturday night into Sunday, low level instability
decreases quickly allowing clouds and showers to diminish under
the westerly flow aloft. The cold pocket aloft will linger over
north Idaho into Sunday afternoon with popcorn type showers and a
renewed threat of thunderstorms. By Sunday night into Monday, a
shortwave upper level ridge will build over the region with some
drying, warming aloft and stabilization. Temperatures will warm
slightly with light easterly winds. This ridge is in response of a
digging trough off the west coast and leading to a slower arrival
of the next round of precipitation. /rfox.
Monday Night through Tuesday Night: Throughout this time period
conditions still look to remain active as models are bringing in
another Pacific system. Monday Night will see the transition from
the early week ridge to the mentioned incoming system. Model
consistency for the system has not been great, but this would be
expected this far out. Timing for now looks to be in the late
Monday range to reach the Cascades and then early Tuesday for the
remainder of the region. Currently the GFS brings the system
further south leading to more of the associated precip staying
south of our area, but the Euro keep it further north leading to
increased precip. With it being almost a week out, we have plenty
of time to iron out the details. Concerning temperatures we look
to remain near normal for the first part of April. Winds look to
increase as the system passes, but as to what magnitude is yet to
be determined. /Fliehman
&&
.AVIATION...
18Z TAFS: An occluded front will pass from west to east across the
region this afternoon. Isolated to scattered showers can be
expected along the front this afternoon and is expected to clear
east of KCOE between 00-03Z. The front will also bring breezy
westerly to southwesterly winds with gusts up to 20-25 mph
possible late this afternoon into this evening. We will also see a
potential for some thunderstorms this afternoon in the Cascade
Mtns and also across southeast WA and into the central ID
Panhandle. Chances for thunderstorms is small and may impact the
KEAT, KPUW and KLWS TAF sites primarily for the late afternoon and
early evening hours. Isolated showers will continue into tonight
and models are hinting at the possibility of some low stratus
early Wednesday morning at KGEG, KSFF and KCOE; however, models
may be overdoing the boundary layer moisture a bit and will likely depend
on how much rainfall we receive today. /SVH
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 36 52 36 48 33 47 / 30 30 40 80 40 90
Coeur d`Alene 35 52 35 45 33 47 / 30 40 50 80 60 90
Pullman 37 52 38 47 34 49 / 60 20 70 70 40 80
Lewiston 41 58 40 52 36 55 / 70 20 70 70 40 70
Colville 34 57 33 51 34 51 / 30 30 20 70 30 90
Sandpoint 35 48 32 44 34 45 / 50 50 30 80 60 90
Kellogg 35 48 32 44 33 46 / 70 50 60 80 70 80
Moses Lake 38 59 37 57 38 55 / 20 10 20 20 20 80
Wenatchee 37 59 35 56 37 53 / 30 10 30 20 20 80
Omak 34 57 33 56 33 51 / 40 10 10 30 20 70
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
612 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 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 612 PM CDT WED MAR 26 2014
A SHORT WAVE TROUGH IS ADVANCING NORTHEAST OUT OF EASTERN KANSAS
LATE THIS AFTERNOON. THIS WAVE IS EXPECTED TO PASS JUST TO THE
SOUTH OF THE REGION BY LATE TONIGHT. THE WARM AIR ADVECTION AND
ISENTROPIC UP GLIDE ON THE 285K SURFACE COMBINED WITH THE LIFT
FROM THE WAVE IS EXPECTED TO BE ENOUGH TO ALLOW SATURATION TO
OCCUR AFTER 06Z. INITIALLY IT LOOKS LIKE THE PRECIPITATION WILL BE
LIGHT AND WITH TEMPERATURES ABOVE FREEZING...SHOULD SEE SOME
DRIZZLE DEVELOP ALONG WITH MVFR CEILINGS. AS THE NEXT SHORT WAVE
TROUGH COMES IN FROM THE WEST THURSDAY...THE FORCING WILL INCREASE
WITH THE PRECIPITATION BECOMING HEAVIER AND HAVE INDICATED A
SWITCH TO RAIN WITH THE CEILINGS CONTINUING TO COME DOWN WITH IFR
SHORTLY AFTER 12Z AT KRST AND AROUND 18Z FOR KLSE. SOME
DIFFERENCES BETWEEN THE MODELS FOR THURSDAY AFTERNOON WITH THE
POSITION OF THE SURFACE LOW AND WHETHER THE FRONTOGENESIS ON THE
NORTHWEST SIDE OF THE LOW WILL BRING THE HEAVIEST RAINFALL INTO
THE TAF SITES OR NOT. THE 26.18Z GFS AND 26.12Z ECMWF BRING THE
HEAVIER RAIN INTO KRST BUT NOT KLSE WHILE THE 26.18Z NAM DOES NOT
SHOW IT FOR EITHER SITE. HAVE OPTED TO TREND TOWARD THE GFS AND
ECMWF AND BROUGHT THE VISIBILITY DOWN TO IFR DURING THE AFTERNOON
FOR KRST. BEFORE THE PRECIPITATION AND LOW CLOUDS ARRIVE...LOOKS
LIKE THERE IS THE POTENTIAL FOR SOME LOW LEVEL WIND SHEAR AT BOTH
TAF SITES. BOTH THE NAM AND 26.21Z RAP INDICATE WINDS BETWEEN 1500
AND 2000 FEET SHOULD INCREASE TO AROUND 50 KNOTS THIS EVENING AND
THEN MAINTAIN THESE SPEEDS THROUGH THE NIGHT. SOME UNCERTAINTY ON
HOW FAST THIS WILL DEVELOP THOUGH. COMPARING THESE MODELS TO THE
VWP/S FROM SURROUNDING RADARS...SUGGESTS THE MODELS ARE AT LEAST
10 KNOTS TOO HIGH WITH THE WIND SPEEDS LATE THIS AFTERNOON...SO
HAVE PUSHED BACK THE BEGINNING TIME OF THE WIND SHEAR TO ABOUT
02Z.
&&
.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 LA CROSSE WI
1110 PM CDT MON MAR 24 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
LATEST WATER VAPOR SATELLITE IMAGERY INDICATING SEVERAL SHORTWAVE
TROUGHS EMBEDDED IN NORTHERLY FLOW ALOFT OVER THE NORTHERN PLAINS
AND CENTRAL CANADA. LATEST MOSAIC RADAR SHOWS NUMEROUS SNOW
SHOWERS ACROSS FORECAST AREA BACK INTO CENTRAL MINNESOTA. THIS IS
IN RESPONSE TO STEEP LAPSE RATE UP TO 750MB PER LATEST RAP BUFKIT
SOUNDINGS.
TONIGHT...ANOTHER IMPULSE EMBEDDED IN THE NORTHERLY FLOW ALOFT
WILL MOVE OVER THE FORECAST AREA AND GREAT LAKES REGION. THE
24.12Z GFS/NAM AND 24.18Z BUFKIT SOUNDINGS SUGGEST STEEP LAPSE
RATES UP TO 850MB...500-300MB POTENTIAL VORTICITY ADVECTION AND
FORCING ABOVE 700MB IN ASSOCIATION WITH THE IMPULSE. THIS WILL
CONTINUE THE ISOLATED TO SCATTERED SNOW SHOWERS OVER FORECAST
AREA TO AROUND 09Z TUESDAY. HAVE INTRODUCE THIS TREND INTO THE
FORECAST.
BEHIND SHORTWAVE TROUGH...COLDER AIR WILL FILTER INTO THE AREA
TUESDAY...WITH 925MB TEMPERATURES FALLING INTO THE MINUS TEENS
DEGREES CELSIUS BY 18Z TUESDAY. TEMPERATURES WILL BE WELL BELOW
NORMAL AND HIGH TEMPERATURES EXPECTED TO CLIMB INTO THE TEENS TO
MIDDLE 20S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 318 PM CDT MON MAR 24 2014
FOCUS TURNS TO WEDNESDAY INTO THURSDAY NIGHT...AS NEXT SYSTEM
AFFECTS THE UPPER MIDWEST AND GREAT LAKES REGION. THE 24.12Z NAM
AND GFS CONTINUE TO BE THE MOST PROGRESSIVE AND FARTHER NORTH
PLACEMENT WITH THIS SYSTEM COMPARED TO THE 24.12Z ECMWF AND GEM.
THE 24.12Z MODELS ARE IN AGREEMENT DECENT WARM AIR ADVECTS INTO
THE AREA OUT AHEAD OF THE SYSTEM AND WRAPS INTO THE SYSTEM. THIS
WOULD ALLOW FOR MUCH OF THE PRECIPITATION TO FALL AS RAIN ACROSS
THE FORECAST AREA WEDNESDAY NIGHT INTO THURSDAY. THIS IS EVIDENT
WITH THE 24.12Z GFS/NAM BUFKIT SOUNDINGS SHOWING TEMPERATURES
ABOVE ZERO UP TO 850MB ACROSS MUCH OF THE FORECAST AREA AFTER 06Z
THURSDAY INTO THURSDAY AFTERNOON. THE 24.12Z MODELS INDICATE
SURFACE FRONT PASSAGE LATE THURSDAY AFTERNOON INTO THURSDAY NIGHT
ACROSS FORECAST AREA. THE PRECIPITATION SHOULD TRANSITION TO ALL
SNOW FROM WEST TO EAST ACROSS FORECAST AREA THURSDAY EVENING INTO
THURSDAY NIGHT. HOWEVER...WITH INCONSISTENCIES OF TIMING AND
PLACEMENT OF SYSTEM BY ALL THE MODELS WEDNESDAY NIGHT INTO
THURSDAY NIGHT...CONFIDENCE IN FORECAST AT THIS TIME PERIOD IS
LOW.
FRIDAY INTO SUNDAY MAIN FORECAST CONCERNS ARE TEMPERATURES ACROSS
THE FORECAST AREA. THE 24.12Z GFS/ECMWF BOTH ARE IN AGREEMENT IN
BREAKING DOWN UPPER LEVEL TROUGH OVER THE GREAT LAKES REGION AND
BUILDING SHORTWAVE RIDGE OVER THE NORTHERN PLAINS AND UPPER
MIDWEST THIS WEEKEND. THE MODELS SUGGEST 925MB TEMPERATURES
WARMING TO AROUND PLUS 10 DEGREES CELSIUS BY 00Z SUNDAY OVER
FORECAST AREA. THIS SHOULD ALLOW TEMPERATURES TO BE NEAR OR ABOVE
NORMAL SUNDAY. THEN...THE 14.12Z GFS/ECMWF BEGIN TO DIVERGE EARLY
NEXT WEEK WITH SHORTWAVE TROUGH EMBEDDED IN WEST TO EAST ZONAL
FLOW ALOFT. THE 24.12Z ECMWF MUCH MORE PROGRESSIVE AND STRONGER
WITH SHORTWAVE TROUGH AND INDICATES PRECIPITATION TO OVERSPREAD
THE FORECAST AREA MONDAY. THE 24.12Z GFS IS SLIGHTLY SLOWER AND
WEAKER WITH SHORTWAVE TROUGH AND DELAYS ANY PRECIPITATION INTO THE
FORECAST AREA BY 18Z MONDAY. AT THIS TIME...WILL INTRODUCE PRECIPITATION
CHANCES ACROSS FORECAST AREA SUNDAY NIGHT AND MONDAY.
PRECIPITATION SHOULD REMAIN AS ALL RAIN AS TEMPERATURES REMAIN
WELL ABOVE ZERO DEGREES CELSIUS IN THE NEAR SURFACE BOUNDARY LAYER
TO 800MB PER BUFKIT SOUNDINGS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1110 PM CDT MON MAR 24 2014
NEXT SHORTWAVE TROUGH SINKING SOUTHWARD ACROSS MN AT LATE
EVENING...AND WAS TRIGGERING A FEW -SHSN PER LATEST 88-D RADAR
RETURNS. NO VSBY RESTRICTIONS INDICATED VIA SFC OBS AS OF YET...BUT
BELIEVE THEY WOULD BE CAPABLE OF MVFR VSBYS FOR A BRIEF PERIOD.
RAP13/NAM12 SUGGEST THESE SHOWERS WILL DIMINISH BEFORE REACHING
KRST/KLSE. GIVEN THEIR SCATTERED NATURE AND THE MODEL TRENDS...WILL
LEAVE THEM OUT OF FORECAST FOR NOW.
SATELLITE IMAGERY INDICATED SCT SKIES FOR THE MOST PART...WITH
POCKETS OF BKN. CIGS WERE GENERALLY VFR THOUGH. EXPECT SCT-BKN
CONDITIONS FOR TUE...WITH SC/CU DEVELOPMENT IN THE LATE MORNING. A
CHANCE FOR 2.5 KFT BKN CIGS...BUT CONFIDENCE NOT HIGH ENOUGH TO ADD
TO THE FORECAST AS THIS MOMENT. WINDS WILL STAY FROM THE
NORTHWEST...GENERALLY NEAR OR ABOVE 10 KTS FOR MUCH OF THE TAF
PERIOD.
&&
.HYDROLOGY...
ISSUED AT 318 PM CDT MON MAR 24 2014
COLDER AIR IS HELPING WITH SNOW MELT AND ASSOCIATED RUNOFF INTO
AREA RIVERS AND STREAMS. WARMER TEMPERATURES ARE EXPECTED
WEDNESDAY INTO THURSDAY...AND THE THREAT FOR PRECIPITATION. DURING
THIS TIME PERIOD WILL HAVE TO MONITOR THE RIVER LEVELS CLOSELY
FOR RISES AND POSSIBLE FLOODING IF ENOUGH RAIN FALLS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DTJ
LONG TERM....DTJ
AVIATION.....RIECK
HYDROLOGY....DTJ
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 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...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 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 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...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 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 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 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 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
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
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 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
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
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 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
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 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 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 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