Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 05/14/17
Area Forecast Discussion
National Weather Service Albany NY
1018 PM EDT Sat May 13 2017
.SYNOPSIS...
An area of low pressure located along the mid Atlantic coast
will strengthen and track northeast along the east coast to
eastern New England through Sunday. This coastal storm will
bring a widespread rainfall to the region over the weekend,
along with cool temperatures. Showery, cool and breezy
conditions will continue on Monday as low pressure only slowly
pulls away from the eastern New England coast.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
As of 1018 PM EDT...KENX radar imagery shows steady rainfall
over all of eastern New York and western New England. According
to surface observations, rainfall is falling not quite as hard
as radar would suggest, and this is probably due to some bright
banding within the radar data, as the higher echos on radar are
occurring where dual-pol variables suggest that melting layer is
located. Surface observations are showing rain rates of a
quarter to a third of an inch per hour over western New England.
Light to occasionally moderate rainfall is ongoing over the
area, as a wave of low pressure slowly lifts northeast off the
Jersey shore and starts heading northeast towards southern New
England. 3km HRRR suggest that the heaviest/steadiest rainfall
will be this evening, and radar will be slowly ending from
southwest to northeast through the overnight hours.
By daybreak Sunday the coverage of rain should decrease as far
east as perhaps to the Hudson Valley with the steadier rain
persisting in western New England. The rain and clouds should
prevent temperatures from falling much through the night but
with some ageostrophic flow from the east where there is some
drier low level air, some diabatic wet bulb temperature effects
could allow temperatures to fall into the mid 40s but lower 40s
northern areas.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
Upper energy in Canada will merge with the upper energy
currently over our region creating a larger scale upper cut off
low. There will be quite a cold pool aloft tracking through our
region Sunday with steep midlevel lapse rates. The upper
dynamics and moisture over our region will support increasing
coverage of showers and some isolated thunderstorms through the
day. There could be some wet snow around the higher peaks in the
mountains, and maybe some graupel or hail in some of the
showers and thunderstorms in lower elevations.
Any holes in the clouds Sunday morning should close as
widespread convective cloud cover forms with the surface heating
and the cold air aloft. Temperatures will reach the 50s to
around 60. Any showers and isolated thunderstorms should end
Sunday evening as the upper energy and cold pool aloft begins to
exit. Clouds will still linger through much of Sunday night but
some breaks in the clouds are possible toward daybreak in some
areas. Boundary cold air advection spreads into our area toward
daybreak and winds will rapidly increase as well.
Upper energy will continue to exit Monday and the last lingering
areas of the upper cold pool will also exit. Still, some shallow
instability will contribute to widespread cloud cover forming
through the daytime heating with some scattered showers. Best
coverage of showers will once again be in higher terrain. Cold
advection will spread over our region through the day and
boundary layer winds will be quite strong. It will be quite
windy Monday and some consideration for a wind advisory may be
needed as we get closer to Monday. Highs Monday in the 50s to
lower 60s.
Better subsidence and clearing over our region Tuesday as
high pressure builds in and boundary layer temperatures begin to
warm. Winds will be lighter, too. Highs Tuesday in the lower to
mid 70s but mid to upper 60s northern areas.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Much warmer air will be moving into the region for the long term
period, finally allowing for an extended return to above normal
temperatures.
With an upper level ridge in place, 850 hpa temps will rise to +15
to +17 C by Wednesday. The high heights should help prevent much
convection for forming on Wednesday, so it looks to be mainly dry
across the area for Wednesday with a mostly to partly sunny sky with
temps reaching into the 80s. Warm temps should continue into
Thursday, but an approaching upper level shortwave over the Great
Lakes could allow for some afternoon or evening showers and
thunderstorms in some areas, especially for northern and western
parts of the area.
As the upper level shortwave slides across the area, there could be
some additional scattered showers or thunderstorms on Friday. More
clouds and cooler temps aloft may allow for temps to be a little
cooler, but still above normal with highs into the 70s. Over the
weekend, heights look to quickly rise once again as the shortwave
departs off to the east, allowing for warm temperatures to move back
into the region by Saturday.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
Steady light rainfall is occurring over the area with
widespread MVFR conditions for both visibility and ceilings.
With the heaviest rainfall south/east of the area, would expect
the IFR conditions to stay away from the area as well, as
conditions should primarily remain MVFR tonight. Cannot totally
rule out a brief lowering to IFR from time to time, but flying
conditions should mainly be MVFR overnight, with visibility in
the 4-6 SM range and ceilings 1500-3500 ft. Steady rainfall
should end towards daybreak Sunday, but cannot rule out some
lingering showers at times into Sunday morning. Ceilings may be
close to the borderline for VFR and high end MVFR at that time
for all sites.
Another period of steadier rain showers looks to occur on Sunday
afternoon into Sunday evening, as the upper trough will be
overhead. Flying conditions looks to be MVFR during that time
as well for both visibility and ceilings.
Light and variable winds overnight with gradually become N to NW
by late in the day Sunday at 5-10 kts.
Outlook...
Sunday Night: Moderate Operational Impact. Windy With Gusts To 31.0 Chance of SHRA...TSRA.
Monday: Moderate Operational Impact. Windy With Gusts To 36.0 Slight Chance of SHRA.
Monday Night: Low Operational Impact. Breezy NO SIG WX.
Tuesday: No Operational Impact. NO SIG WX.
Tuesday Night: No Operational Impact. NO SIG WX.
Wednesday: Low Operational Impact. Slight Chance of SHRA...TSRA.
Wednesday Night: No Operational Impact. NO SIG WX.
Thursday: Moderate Operational Impact. Chance of SHRA...TSRA.
&&
.FIRE WEATHER...
An area of low pressure located along the mid Atlantic coast
will strengthen and track northeast along the east coast to
eastern New England through Sunday. This coastal storm will
bring a widespread rainfall to the region over the weekend,
along with cool temperatures. Showery, cool and breezy
conditions will continue on Monday as low pressure only slowly
pulls away from the eastern New England coast.
Relative humidity values recover to 85 to 100 percent tonight
with rain much of the night. RH values only drop to 55 to 75
percent on Sunday and recover to 80 to 100 percent Sunday night.
Rh values drop to 50 to 70 percent Monday afternoon. Variable winds
at 15 mph or less will shift to the northeast tonight at 5 to
10 mph and be from the northwest at 5 to 15 mph on Sunday. Winds
will become north to northwest at 15 to 30 mph Monday.
&&
.HYDROLOGY...
A developing coastal storm will bring a widespread rainfall to
our hydrologic service area through Sunday with generally three
quarters of an inch of additional rain. Some higher amounts up
to 1.5 inches area possible for areas well south and east of
Albany into parts of eastern Dutchess, Berkshire and Litchfield
counties.
This amount of rainfall is forecast to result in within bank
river rises around or short of action stage due to runoff, but
flooding is not expected due to active vegetation reducing some
runoff. The heaviest rain will likely fall well to the east
towards coastal New England.
Mainly lighter showers should linger into Monday, as the
coastal storm will be slow to exit the eastern New England
coast. Drier and warmer weather will finally build in towards
the middle of next week.
For details on specific area rivers and lakes, including
observed and forecast river stages and lake elevations, please
visit the Advanced Hydrologic Prediction Service /AHPS/ graphs
on our website.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...None.
NY...None.
MA...None.
VT...None.
&&
$$
SYNOPSIS...NAS
NEAR TERM...Frugis/NAS
SHORT TERM...NAS
LONG TERM...Frugis
AVIATION...Frugis
FIRE WEATHER...NAS
HYDROLOGY...NAS
Area Forecast Discussion
National Weather Service Bismarck ND
900 PM CDT Sat May 13 2017
.UPDATE...
Issued at 858 PM CDT Sat May 13 2017
Scattered showers and a few thunderstorms moving into southwest
North Dakota. So far do not anticipate severe weather but some
gusty winds in an inverted V T-RH profile possible. Made some
small changes to evening pops.
UPDATE Issued at 527 PM CDT Sat May 13 2017
Current radar and satellite loops show thunderstorms forming off
the western Black Hills of South Dakota and west into north
central Wyoming. Current thinking continues to be the updraft
helicity signal will support one or two strong updrafts late this
evening in southwest North Dakota. Current radar and satellite
support this trend. Current forecast looks good.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 207 PM CDT Sat May 13 2017
The main concern in the short term period will be the chance of
thunderstorms tonight. Short term and high resolution model
solutions continue to show convection developing across eastern
Montana, moving into western North Dakota later this evening. The
Storm Prediction Center issued a marginal risk across mainly the
southwest part of the state earlier, and HRRR runs continue to
bring across a few isolated spots of higher 2-5km updraft helicity
values during the late evening. Will continue with the current
configuration in the Hazardous Weather Outlook which mentions an
isolated severe storm in the southwest tonight.
The best rain chances should be in the west initially, with
thunderstorm chances spreading east overnight. A cold front moving
across the region will continue its push east with the main
chances of precipitation for Sunday shifting towards the Turtle
Mountains and James River Valley.
Fire weather will be something to monitor for Sunday, especially
in the west where drier air will move in first. Minimum relative
humidity values fall into the 20 to 25 percent range with westerly
winds of 15 to 25 mph. A couple potentially limiting factors
include the potential for rain tonight, and the current green up
of fuels.
.LONG TERM...(Sunday night through Saturday)
Issued at 207 PM CDT Sat May 13 2017
The long term period will feature a large trough across the
western United States through much of next week. This will eject
shortwaves into the central and northern Plains with periodic
chances for showers and a few thunderstorms. 12Z GEFS plumes show
a large spread in QPF over the next week across western and
central North Dakota with mean values in a broad 1 to 2 inch
range. Overall the model blend captures expected trends and did
not stray far from it`s output. It will also be cooler with highs
5 to 10 degrees below normal for Wednesday through Friday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 652 PM CDT Sat May 13 2017
At 6 pm CDT a low pressure and associated cold front near the
North Dakota and Montana borders will move east tonight. The cold
front will be the focus for widely scattered thunderstorms near
the KISN-KMOT-KDIK areas tonight and move east Sunday. VFR
conditions will predominate through the 00Z TAF period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...CK
LONG TERM...CK
AVIATION...WAA
Area Forecast Discussion
National Weather Service Caribou ME
1010 PM EDT Sat May 13 2017
.SYNOPSIS...
High pressure will move into eastern Canada overnight. Low
pressure rides north along the east coast and will spread a
soaking rain into the area Sunday morning and continue into
Monday.
&&
.NEAR TERM /THROUGH SUNDAY/...
1015 PM Update...
CLouds continue to fill in w/some holes showing up across the nw
and down to se sections of the CWA. Temps from the Bangor
region down to the coast were in the mid to upper 40s while n of
these areas, temps were in the low to mid 50s. The clouds will
help to limit temps from dropping off too far overnight.
Some fog developed right along the immediate coast and outer
islands. Added areas of fog to the forecast overnight. The
latest RAP and NAM12 soundings showed this potential w/the blyr
layer moistening up. Radar loop showed the leading edge of the
rain just beginning to show up along the ME/NH border. The
latest RAP doing well w/this setup. Daycrew`s assessment of
keeping the rain at bay til well after midnight for the ssw
areas looks good. No changes made to the pops w/this update.
Previous Discussion...
Clouds will continue to increase and thicken this evening in
advance of low pressure along the mid atlantic coast, while high
pressure across the Canadian Maritimes continues to slide east.
The low will track toward the northeast tonight. The air mass
is still relatively dry, so it will take a while for atmosphere
to moisten up, thus not expecting rain to spread downeast areas
until after midnight. Concern is we could start to see some
stratus and patchy drizzle developing later this evening along
the downeast coast in the light southeast flow around the
departing, high before the steadier rain moves in later tonight.
Otherwise, the rain will slowly spread northeast across central
areas by daybreak, but it will remain rain free overnight
across far northern areas and the St. John Valley. Expect lows
tonight to be generally in the low to mid 40s across the region.
Sunday is shaping up as wet day, especially across central and
down east areas, as low pressure tracks northeast toward the
gulf of Maine. The rain may be locally heavy at times across
downeast by afternoon, as abundant moisture gets transported
ahead of the approaching low. However, across far northern
Maine, especially the St. john Valley, the rain should hold off
until afternoon. Rainfall amounts through Sunday afternoon are
expected to range from around a tenth of an inch across far
northern areas, to as much as an inch and one half across the
downeast coast. East to northeast winds will keep high
temperatures on Sunday well below normal for this time of year,
with the warmest readings across far northern areas, where
highs will range from the low to mid 50s. However, highs across
downeast areas will generally be in the mid to upper 40s.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
Models cont to struggle with the Nrn cut-off of sig rnfl
associated with low pres movg off the mid Atlc states to S
of Nova Scotia...with every opnl 12z model run showing sig
less QPF across the far N and a sharp grad of increasing QPF
toward Downeast areas. Subsequently, we lowered fcst QPF across
Nrn areas Sun Ngt into Mon compared to the last fcst. We did
go literally with as low as this recent model run suggests attm
for the far N, which is little or none, just in the event this
is a spurious Srly bias model run, but it`s interesting to note
that this run looks similar to what was advertised by the 6-10
day CPC outlook when this event was cntrd in pd earlier this
week.
Rn will taper to sct showers from N to S durg the day Mon as the
upper low slowly move E to S of Nova Scotia and drier air llvl
air from the N moves into the region. Sct shwrs may attms still
may brush Ern and Nrn ptns of the region Mon ngt into Tue,
otherwise, cldnss will be to decrease spcly ovr Swrn ptns of the
Rgn. Temps will be coolest relative to avg for hi temps Mon with
recovering hi temps on Tue.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
Models now indicate a pd of low and mid lvl warm advcn beginning
late Tues ngt and contg right into Thu. A weak s/wv topping a
building 500mb ridge could result in sct shwrs across the N and
W Wed aftn into Wed ngt. Aftwrds, models now indicate a high chc
that all of our region will enter the warm sector on Thu as the
500mb ridge crosses the Rgn. We raised hi temps sig upwards...
but to be honest, if this scenario shown by the models were to
hold as we get closer to real tm, we can see 80 deg+ hi temps
Thu across all low trrn lctns N of the Downeast coast, with more
sunshine then what we are advertised. For now, we show mid 70s
N to lower 80s SW. We try to delay the Tmg of shwrs and
possible tstms for the region til later Thu aftn into Thu eve
from blended model guidance to better tm with the passage of a
cold front ovrngt Thu. For now, Fri and Sat will be cooler with
closer to seasonal norms for temps.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
NEAR TERM: Low pressure will track northeast from the mid atlantic
region tonight through Sunday. Widespread rain will develop
from southwest to northeast late tonight through Sunday, not
reaching far northern Maine til after 16z Sunday.
KFVE/KCAR/KPQI/KHUL...VFR tonight becoming MVFR after 16z Sunday
in developing rain and decreasing ceilings.
KBGR/KBHB...VFR this evening giving way to developing MVFR
ceilings by 06z, with possible IFR ceilings developing in lower
clouds vcnty BHB. Expect widespread IFR most of Sunday in rain
and low ceilings
SHORT TERM: IFR clg/vsby conditions in rn can be xpctd all TAF
sites Sun ngt into Mon morn, with conditions improving to MVFR
by Mon aftn and then VFR Mon ngt into Tue, with brief MVFR clgs
with shwrs msly Nrn TAF sites. VFR conditions will then
completely prevail Tue ngt thru Thu.
&&
.MARINE...
NEAR TERM: Winds/seas will remain below small craft levels
tonight before increasing to strong small craft levels by
Sunday afternoon. As low pressure intensifies and tracks toward
the gulf of Maine later Sunday, a few wind gusts up to 35 kts
will be possible.
SHORT TERM: SCA winds and seas will cont Sun ngt into Mon aftn,
then improve to below SCA conditions Mon ngt and cont so thru
mid week.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...None.
MARINE...Small Craft Advisory from 8 AM Sunday to 1 PM EDT Monday for
ANZ050>052.
&&
$$
Near Term...Hewitt
Area Forecast Discussion
National Weather Service State College PA
1137 PM EDT Sat May 13 2017
.SYNOPSIS...
Drier will overspread the region tonight. A pool of cold air
aloft will pass over late tonight and Sunday. An anomalous
upper ridge will migrate from the Mississippi Valley to the east
coast next week. Much warmer temperatures will prevail for the
later part of the week.
&&
.NEAR TERM /UNTIL 8 AM SUNDAY MORNING/...
All is well as the precip over the east has all but dried up and
the convection from the NW is just now entering wrn PA. Things
continue to break up as we lose heat, and 30-40 POPs at most
will do fine for coverage. With the late clearing and rain up
until that time, the light wind overnight could allow some fog
to form if the air does not dry out over the east.
Prev...
Trapped in between the departing low to the east and the ridge
to our west. The late day sunshine and residual moisture have
combined to pop isold shra over the mountains. These should not
last long past sunset as they are not supported by anything
serious aloft. A more serious area of forcing associated with
strong short wave trough crossing the lower lakes is making
taller convection. HRRR pushes most of this convection over wrn
PA and it takes a while to get into the Laurels/Alleghenies.
Will hold just sct POPs for the night in the west. But, the cold
pool and best forcing will be overhead by morning. While most of
the convection will be to our N/E, POPs of likely or better seem
on order for the nrn tier later tonight. Still a few strikes of
ltg as it crosses the lake, where water temps are cooler than
the ground. So, a bolt or two is not out of the question - but
more so to the north of central PA.
&&
.SHORT TERM /8 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
Upper low tracks over upstate NY on Sunday, while pool of cold
air aloft combined with diurnal heating results in isolated to
scattered mainly afternoon showers especially over the northern
tier counties. Expect some gusty winds to mix to the surface by
afternoon...as Bufkit soundings support frequent gusts in the
25-30kt range. Partly sunny skies and deeper mixing will result
in a milder Sunday, but max temps should still fall several
degrees short of climo.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
A deep upper level low will drop southeast on Sunday across the
northeast on Sunday. Gusty winds will likely prevail into
Monday, given the dynamics of the system.
Did extend the showers into Sunday evening, given the cold air
aloft, even with the low dewpoints. General thunder fcst further
north.
Did lower temperatures a tad Sunday Night and Monday Night, but
did up a degree higher or so for Monday.
Main change was to take out showers and storms for Tuesday and
Wednesday, given the EC is dry, and strong height rises occur,
as an anomalous upper ridge builds over the eastern states.
Above normal temperatures for several days.
Model consensus drops a dying cold front into the area on
Friday. Slightly cooler weather to follow.
There still could be a few showers or storms with the front
trying to work back northward next weekend. 00Z EC show a hint
of a QPF max across the southeast part of the CWA next Friday.
Not seeing that on the 12Z EC run, but did not want to go with
no weather at this point.
The main thing is to get a few warm and dry days, so folks can
get outside projects done, and area fields can dry out.
Much wetter than last year across the north and west.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
The low has moved to the northeast as dry northwesterly flow
has overtaken the region. For the most part skies have gone VFR.
The last vestiges of low level moisture has brought MVFR to
LNS and MDT with IFR to IPT. With low dewpoint depressions and
light winds overnight, expect IFR and lower to continue at IPT
until the winds can mix out tomorrow and the strong
northwesterly winds to dry the lower levels. As temperatures
drop tonight, MVFR to periods of IFR remain possible, especially
after 09Z as a short wave trough will move through. Cigs and
vsbys will improve between 13Z to 16Z. NW winds pick up to
breezy/windy levels as we slip back into a more winter- like
flow pattern with restrictions confined to the NW half of CWA.
Scattered rain showers develop over NE 1/3 of CWA in the coldest
air aloft.
.OUTLOOK...
Sun-Sun Night...Cig restrictions likely BFD/JST, and poss at
times into the Central Mtns. Becoming windy.
Mon...Breezy. No sig wx.
Tue-Thu...No sig wx expected.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Dangelo
NEAR TERM...Dangelo
SHORT TERM...DeVoir/Fitzgerald
LONG TERM...Martin
AVIATION...DeVoir/Ceru
Area Forecast Discussion
National Weather Service Grand Forks ND
941 PM CDT Sat May 13 2017
.UPDATE...
Issued at 939 PM CDT Sat May 13 2017
No changes to temperatures tonight as breezy winds will keep temps
warm tonight, generally in the mid 50s. Did update sky as NW zones
are seeing mid level cigs move across rgn...and populated with 12Z
Canadian which has a reasonable handle on sky for tonight while
hi-res models are too clear.
UPDATE Issued at 640 PM CDT Sat May 13 2017
Several changes to Tomorrow period made on early evening
forecast. Inherited temps did not reflect recent cool trend in
SuperBlend and have bumped up Sunday temps across entire domain.
Made adjustments to old sky grids with the latest RAP guidance and
populated winds with latest time lagged CONSSHORT as wind shift
tomorrow will impact aviation grids. No changes to POPs at this
time but they may be a bit too aggressive on timing into western
zones. Will see how 00Z runs look before adjusting.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 252 PM CDT Sat May 13 2017
Expect fair skies and seasonably mild and dry conditions through
the remainder of the afternoon and evening. Gusty southeast winds,
warm temperatures, and low humidity levels will keep the threat
for wildfires somewhat elevated until early evening.
Overnight... a low pressure system will deepen into the western
Dakotas late this evening and slowly edge eastward into the
central Dakotas by mid morning. Along and ahead of this system
expect to see increasing mid level cloudiness and scattered rain
showers developing... with an isolated thunderstorm or two
possible. Low temperatures should settle into the upper 40s near
the Canadian border and into the lower 50s nearer the South Dakota
border.
Scattered showers should spread into eastern ND on Sunday
forenoon and spread across the Red River Valley by midday. This
band of scattered showers and isolated thunderstorms should
continue to edge eastward across northwest MN through the
afternoon...with sunshine returning in the west. Rainfall
accumulations should be spotty with a few hundredths to a tenth
of an inch or so most likely... and mainly north of the I-94
corridor. Otherwise patchy and warm sunshine should be evident as
well... with high temperatures ranging from the upper 60s near the
Lake of the Woods to the lower 80s in the southern Red River
Valley.
.LONG TERM...(Sunday night through Saturday)
Issued at 252 PM CDT Sat May 13 2017
Sunday night through Saturday...
An active pattern is still on tap for the upcoming week with
multiple opportunities for precipitation. The main upper ridge that
dominated the central portion of the country throughout the weekend
will finally begin to slide off to the east by Sunday night.
Southwest flow aloft then sets up which will contribute to the
upcoming active pattern.
A weak wave following on the heels of the upper ridge will allow
some minor precipitation chances to linger Sunday night and into
early Monday. A small area of high pressure looks to quickly pass
through between stronger waves with the possibility of a brief break
in precipitation chances later on Monday.
The main precipitation producer for the week continues to be the
system(s) arriving late Monday and lingering into Wednesday. The
first of two surface low pressure systems set to impact the area
during this time frame quickly pulls out of the eastern Rockies and
deepens as it propagates off to the north and east. Respectable
instability parameters and shear profiles suggest a decent chance
for thunderstorms (especially across the south, at least with the
current surface low track) for Tuesday afternoon and evening. A
secondary low looks to develop on the heels of the first in the
Tuesday night and Wednesday time frame, bringing additional
precipitation chances. Models runs currently depict the track of the
second low to pass further south and east than the first which will
be a factor in who sees the best storm chances. Regardless, between
the two systems, a fairly widespread area of an inch or more of
rainfall is likely with higher amounts in any convection.
Thursday looks to be the driest day of the week as upper ridging
briefly builds back into the area. Yet another system is progged to
push through the region to end the work week and start the weekend.
Monday will bring one last day of above normal temperatures in the
70s or low 80s. Tuesday will bring slightly cooler temperatures
before more cooler air is ushered into the area by Wednesday with
highs struggling to reach out of the 50s or 60s for the remainder of
the week. However, lows should remain relatively mild with plenty of
clouds and moisture sticking around.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 640 PM CDT Sat May 13 2017
VFR. A cool front will bring a band of showers and possibly a TS
across region tomorrow, but not enough confidence on timing to
mention in sites east of DVL at this time. Expect associated cigs
to be in the low VFR range...with wind shift being primary
aviation issue.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
&&
$$
UPDATE...Speicher
SHORT TERM...Gust
LONG TERM...Lee
AVIATION...Speicher
Area Forecast Discussion
National Weather Service Green Bay WI
1037 PM CDT Sat May 13 2017
Updated aviation portion for 06Z TAF issuance
.SHORT TERM...Tonight and Sunday
Issued at 239 PM CDT Sat May 13 2017
A NW-SE orientated band of weak radar returns persist across the
forecast area late this afternoon. This benign activity is in
association with LFQ of upper jet and associated weak shortwave
impulse moving southeast across the area within a region of
rather steep low-level lapse rates. However, as indicated by the
12UTC GRB sounding this morning, atmosphere below 700 mb quite dry
thus any precipitation is struggling to reach the surface. HRRR
and NAM-Nest are in agreement that weak upper-level forcing and
associated weak surface low currently exiting eastern Wisconsin,
will continue to move southeast away from the forecast area, while
surface high pressure begins to build in from the north
overnight. Any light sprinkles should come to an end by sunset.
Associated mid-level cloud deck over the forecast area actually
extends northwest across the Minnesota Arrowhead back to Lake
Winnipeg. These clouds are associated with some weak mid-level
frontogenetic forcing and weak WAA along NW-SE orientated thermal
gradient. Short-range guidance suggests these clouds will be a bit
slower to depart but should gradually work their way east across
the forecast area as the mid-level ridging continues to push east
toward the area later tonight and Sunday. Did tweak min temps up a
notch overnight given some mid-clouds, but pretty much stayed
close to short-term model blend.
On Sunday, upper ridge axis will continue to move toward the
state with surface high pressure ridge axis drifting over Lake
Michigan by around 18 UTC Sunday. In response, boundary layer
southeasterly winds should become well established across most of
the forecast area. This should result in somewhat cooler
temperatures especially over eastern and eastcentral portions of
the forecast area. Meanwhile further upstream, southerly flow
will be on the increase upstream of an elongated area of low
pressure over the northern and central Plains. This will result in
a strengthening warm front extending from northern Illinois, far
southwest Wisconsin to southcentral Minnesota. A few of the high
resolution models are trying to even generate a few light showers
or sprinkles near the frontal boundary well to our south Sunday
afternoon. However, atmosphere is still initially dry so did not
buy that signal.
Overall, Sunday should be a fairly nice spring day with a notable
temperatures contrast from southwest to northeast across the
forecast area. Using blended model guidance gives highs ranging
from around 75 in the southwest to the upper 50s along the
lakeshore and bay where increasing gradient southeast winds will
keep temperatures quite a bit cooler.
.LONG TERM...Sunday Night Through Saturday
Issued at 239 PM CDT Sat May 13 2017
Pattern change starts Sunday night as an upper ridge and surface
high pressure region drifts east over the Great Lakes region. The
departing upper ridge and developing southwest flow in its wake will
bring a warmer and more active pattern to the region for the
start of the new work week.
Progs are already spilling some light precipitation into northwest
Wisconsin over the ridge late Sunday night with the warm air
return. Will continue the small chance of convection for north
central Wisconsin after midnight.
Upper ridge further weakens Monday across the northern Great
Lakes region with the passage of a short wave trough. A developing
frontal system Monday into Tuesday will slowly lift a surface
warm and 850 warm front northward across the state. The warm front
will be a primary location of convection Monday night and may
linger across the north Tuesday. Convection may be on the
increase again over the northwest half of the state as a surface
boundary approaches. Progs then suggest a more significant short
wave trough to track across the region Wednesday night as a cold
front slides through.
Quieter weather appears to be likely the rest of the week as a
cold front drops south of the area and an upper ridge builds into
the area. Another frontal system takes aim for the area toward
the weekend for more showers and storms.
&&
.AVIATION...for 06Z TAF Issuance
Issued at 1036 PM CDT Sat May 13 2017
Quiet weather with good flight conditions will continue. Middle
level clouds that were streaming across the area should gradually
shift off to the east. Winds will be relatively light tonight,
then pick a little from the east/southeast tomorrow.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....ESB
LONG TERM......TDH
AVIATION.......Skowronski
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
707 PM CDT Sat May 13 2017
.SHORT TERM...(This evening through Sunday)
Issued at 313 PM CDT Sat May 13 2017
The HRRR was the basis for the thunderstorm forecast tonight. A
blend of the GFS...NAM...GEM and SREF produced no rain chance so
that forecast strategy was discarded in favor of a more aggressive
soln. Steep mid level lapse rates are in place across the Panhandle
with accas showing on visible satellite. The HRRR suggests the
Cheyenne and Palmer divides and Pine Ridge will be the genesis for
isolated thunderstorm development late this afternoon and this
evening. The air across Ncntl Nebraska is forecast to remain quite
stable and capped at around 12C at h700mb tonight. This should
confine any storm development to Wrn Neb.
Any strong storms which develop could produce gusty winds with cloud
bases around 750mb. The RAP model suggests the best instability will
be across Swrn Neb with favorable shear. An isolated severe storm
with hail and wind could develop.
The blended guidance plus bias correction suggests highs in the 70s
to lower 80s Sunday. Deep vertical mixing is expected with north
winds. Any rain chance should be south of the front across ern Neb
and KS.
.LONG TERM...(Sunday night through Saturday)
Issued at 313 PM CDT Sat May 13 2017
The NAM and GFS generate a MCS Sunday night while the GEM and ECM
are dry. The post-frontal upslope theta-e advection is too much for
the american models and they generate convection. The model blend
suggests a 30-40 POP Sunday night. Storms should form in Ern WY late
in the afternoon and move into the Panhandle in the evening. The
storm mode would be sfc based in the early evening becoming elevated
after dark. The mixed layer and elevated instability is weak in the
GFS and modest in the NAM. Shear calculations are complicated by the
upslope easterlies beneath strengthening southwest winds aloft. SPC
suggested just a general thunderstorm outlook with a conditional
severe weather threat. The question is whether or not the upslope
winds in the models are too moist.
Just isolated thunderstorm chances are in place Monday night with
the NAM...ECM and GEM dry and the GFS developing storms across Scntl
Neb and SD.
A fairly significant thunderstorm chance develops late Tuesday and
Tuesday night. The better severe weather chances (high CAPE and
shear) are over ern Neb. The GEM...GFS and ECM are in reasonable
agreement except for slower evolution in the GEM and ECM which
continue the convection throughout the day Wednesday. The blended
soln or model consensus suggested a 30 to 40 POP Tuesday through
Wednesday.
Chance to likely POPs are in place Thursday for the big upper level
low forecast to affect Wrn and Ncntl Neb through Friday. The best
rain chance is late Thursday and severe weather is likely across KS.
Nebraska may be post-frontal and this would limit sfc based
instability and reduce the overall threat for organized severe
thunderstorm development.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 701 PM CDT Sat May 13 2017
Main aviation concerns will be isolated thunderstorms in the
northwest Nebraska Panhandle and strong southerly winds decreasing
tonight and low level wind shear developing.
Thunderstorms in the Panhandle will dissipate after sunset and
should only pose a marginal threat for strong gusty winds before
then.
Strong southerly winds will diminish through sunset but will not
completely decouple. Low level southerly jet developing around
850mb will create wind shear over western Nebraska tonight.
A cool front will push through from the northwest on Sunday with
winds swithching to the northwest at 15 to 25 mph with higher
gusts.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Power
Updated for 00Z Aviation Forecast Discussion below.
&&
.PREV DISCUSSION... /issued 227 PM CDT Sat May 13 2017/
DISCUSSION...Surface analysis places a ridge of high pressure
centered over Southwest Missouri this afternoon. This has resulted
in sunny skies across the Mid-South with clearing occurring
across extreme Northeast Mississippi and temperatures as of 2 PM
CDT in the 70s at most locations.
Surface and upper level ridging will continue to build across the
Mid-South tonight through Tuesday. This will bring rain free
weather along with pleasant temperatures with lows tonight in the
50s and highs on Sunday rising back into the lower 80s. A gradual
warming trend is expected into next week.
Latest long term model trends indicate the upper level ridge will
begin to move east for mid to late next week. This will allow for
the Lower Mississippi to be positioned on the western periphery
of the upper level ridge axis along with a return of isolated to
scattered showers and thunderstorms, especially along and west of
the Mississippi River into next weekend as a series of mid-level
shortwaves move across the region within southwest flow aloft.
CJC
&&
.AVIATION...
00Z TAFs
Relatively dry surface high pressure will settle over the Midsouth
overnight. 22Z HRRR suggest some patchy fog possible near JBR,
with the pressure ridge centered along and west of the MS River at
12Z. Otherwise, VFR will prevail areawide through the next 24
hours.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion...UPDATED
National Weather Service Miami FL
835 PM EDT Sat May 13 2017
.UPDATE...
Miami tied a record high today of 93 degrees, last reached on this
date in 1985. The line of showers and thunderstorms associated
with the weak cold front has mostly dissipated over most of
Central Florida this evening, except for some showers and a few
thunderstorms near Venice, FL.
The weak cold front will continue to move southward tonight and
should be around Lake Okeechobee region by early Sunday morning
before moving through South Florida on Sunday. The latest HRRR
and MET models are now showing not much activity over South
Florida tonight, except for some showers and a few thunderstorms
along the western areas late tonight as the front approaches
South Florida. The HRRR and MET models are also showing less
activity over South Florida on Sunday, as the deeper moisture is
now forecast to be over the Atlantic waters. Therefore, the pops
have been lowered for tonight and on Sunday over South Florida.
The thunder wording has been removed for the eastern areas for
tonight and lowered to a slight chance for the western areas for
late tonight. The threat of thunder has also been lowered to a
slight chance across South Florida on Sunday.
Rest of the forecast looks good at this time and no other changes
are planned.
.AVIATION...
The winds will be southwest tonight into Sunday over all of South
Florida taf sites. The speeds will be around 15 knots until 02Z
tonight before decreasing to around 5 mph for rest of tonight. The
speeds will then increase to around 10 mph on sunday at all of the
taf sites.
The weather should remain dry over the east coast taf sites
tonight with VCSH at KAPF taf site after 06Z tonight. On Sunday,
showers will be around but the coverage of thunderstorms will be
few and far between. Therefore, VCSH will be in the taf sites for
Sunday and will keep out thunderstorm conditions at this time. The
ceiling and vis should remain in VFR conditions through Sunday,
but could fall down into MVFR conditions with any passage of
shower or thunderstorm activity.
&&
UPDATE...54/BNB
AVIATION...54/BNB
.PREV DISCUSSION... /issued 345 PM EDT Sat May 13 2017/
DISCUSSION...
In the near term, moderate southwest winds this afternoon have
held the Atlantic sea breeze up near the I-95 corridor. Just
enough moisture is in place for isolated to scattered showers to
develop along the sea breeze particularly in the area of strongest
convergence over metro Palm Beach and Broward Counties. Any
showers should dissipate or move offshore around sunset.
Radar and satellite data at mid afternoon showed an area of rain
and thunderstorms near the Interstate 4 corridor in Central
Florida extending back into the central Gulf of Mexico. This
activity was out ahead of a front extending from central Georgia
into the central Gulf.
This evening and tonight, expect this activity to continue slowly
sinking southward toward the area, but should not enter the Lake
Okeechobee region until late tonight as the front finally
approaches. Along with numerous showers ahead of the front, a
plume of deep moisture entrained in the deep southwesterlies ahead
of the front, along with sufficient instability as indicated by
forecast soundings, should allow for isolated to scattered
embedded thunderstorms.
Sunday, the front begins to wash out as it moves through the
area. The remnant trough will continue to push slowly southward,
promoting numerous showers and embedded thunderstorms along and
ahead of it during the morning. Models are in good agreement the
trough should be approaching the southern tip of the Florida
peninsula by mid afternoon, limiting the best chances for rain to
that part of the region late in the day. Behind the trough,
however, sufficient moisture may remain for additional isolated
showers at peak afternoon heating Sunday.
Over the coming work week, a mostly quiet and dry weather pattern
will be in place as a deep ridge of high pressure settles over
the southeast states. Monday winds should be dominated by the Gulf
and Atlantic sea breezes, but as the high develops the region will
see gradually increasing and deepening easterly flow. Just enough
low level moisture will be in place for isolated to scattered
passing showers from time to time, but no strong forcing showing
up for organized rain or thunderstorm activity.
MARINE...
Moderate southwesterly winds this evening and overnight ahead of
an approaching front. The front will wash out into a trough as it
moves across the area late tonight and Sunday, bringing numerous
showers and a few thunderstorms. Winds will slacken Sunday but may
be locally gusty near any thunderstorms. Mostly light winds over
the area waters Monday, but a ridge of high pressure will build
north of the region through the week, with easterly winds
steadily increasing to moderate to fresh levels by the end of the
week.
AVIATION...
Expect all east coast sites except KTMB to go SSE or SE by 19Z at
10-13kts with seabreeze. KAPF and KTMB remain SSW 10-12kts. All
sites may see gusts to 20kts through sunset. Isold TSRA/SHRA with
late afternoon seabreeze collision along east coast, with best
chances near KPBI where have added VCSH 22Z-00Z. Winds diminish
and become SSW 5-8kts after 00Z. Front approaches late tonight,
with VCSH for KAPF after 14/09Z, and for KPBI-KFXE- KFLL after
14/15Z. TSRA threat too low to mention at time, but may need to be
added later as front approaches.
FIRE WEATHER...
Although relative humidity values are staying above 40 percent
this afternoon, gusty southwest winds are promoting very good to
excellent dispersion. Winds will slacken overnight and there will
be a good chance of showers developing as a weakening front moves
into the area. Embedded thunderstorms late tonight into Sunday
morning may bring a few lightning strikes and gusty/erratic winds.
As the front washes out south of the area Sunday afternoon,
slightly lower humidity and 20 ft westerly winds around 10 mph
will filter into the Lake Okeechobee region. If drier air moves in
faster than expected or a break in the clouds can boost
temperatures more than expected, critical conditions may develop
for a few hours Sunday afternoon particularly around Glades
County.
Over the work week, minimum relative humidity values over the
interior will be near 40 percent each afternoon. Wind speeds
generally under 10 mph early in the week will get a bit stronger
later in the week as a ridge of high pressure builds north of the
area. Depending on how much rainfall this area receives this
weekend and later coordination with forestry officials on the
status of fuels, borderline critical conditions may be a concern
any afternoon over interior sections.
&&
.PRELIMINARY POINT TEMPS/POPS...
West Palm Beach 72 90 70 90 / 20 50 20 20
Fort Lauderdale 75 88 74 90 / 10 50 10 20
Miami 74 90 73 91 / 10 50 20 30
Naples 74 87 71 87 / 40 40 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...None.
AM...None.
GM...None.
&&
UPDATE...54/BNB
DISCUSSION...22/KS
MARINE...22/KS
AVIATION...54/BNB
FIRE WEATHER...22/KS
Area Forecast Discussion
National Weather Service Pueblo CO
305 PM MDT Sat May 13 2017
.SHORT TERM...(This evening through Sunday)
Issued at 304 PM MDT Sat May 13 2017
Dry and breezy to windy conditions expected over the next couple
days as persistent upper trof remains in place along the west coast.
Weak shortwave lifting out across CO this afternoon is progged by
short range models to initiate thunderstorms along a dry line across
the southeast plains in both the hrrr and 4km NAM. Overall not much
CAPE to work with...and inverted V soundings suggest gusty winds up
to 45 mph and lightning will be the primary storm threats. Other
high based -SHRA/-TSRA will be possible over the mountains but these
should remain pretty isolated in coverage. All activity winds down
during the evening with a mild night in store as lee troffing keeps
min temps in the upper 40s lower 50s across the lower elevations
with a mix of 30s and 40s for the high country.
Sunday should be a few degrees warmer still with south to southwest
winds mixing down again during the afternoon. Appears to be even
less moisture to work with tomorrow. Will have to watch the far
east plains for potential thunderstorm development along an
advancing dry line...but for now it appears best chance will be over
the border in KS. Otherwise another day for highs in the 80s, even
pushing 90 across the far southeast plains. -KT
.LONG TERM...(Sunday night through Saturday)
Issued at 304 PM MDT Sat May 13 2017
Sunday night through Tuesday...Southwest flow will continue across
the region as the upper low pressure trough sits over the West
Coast...pushing limited moisture into the state. An upper shortwave
is forecast to cross the Great Basin Tue morning, and Colorado Tue
aftn and eve. Therefore, warm sw flow and limited moisture with
isolated dryline convection along the KS border will be the case for
Mon, then more cloud cover and increasing pcpn chances over the mts
as the shortwave crosses on Tue. Winds will become gusty at times
both Mon and Tue afternoons, but do not believe that fuels are at
the point to being receptive to carrying fire, so no fire wx
highlights at this time. Look for high temps in the 70s for the high
valleys and 80s to near 90F for the plains on Mon, then 60s for the
high valleys and 70s to mid 80s for the plains on Tue.
Wednesday through Saturday...A strong upper low pressure system
drops southeast across ID on Wed, then sits over UT and CO on Thu
and Fri before ejecting off to the northeast across NE on Sat.
Current model runs indicate that the majority of the dynamics and
activity associated with this system will remain north of the
forecast area, but it should still remain somewhat active with
scattered showers and thunderstorms over the higher terrain through
Fri, and isolated activity over the plains. As the system exits the
region on Sat, pcpn potential will drop off dramatically. As for
temps, expect max temps in the 60s for the high valleys and upper
60s to near 80F for the plains on Wed. As the low nears then passes
overhead, temps will be cooler and only climb into the 50s and 60s
for most areas, and into the lower 70s near the KS border, for Thu
through Sat. Moore
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 304 PM MDT Sat May 13 2017
Main concern for TAF sites over the next 24 hours will be timing of
gusty south to southwest winds. Winds will gust up to 25-30 kts at
all three terminals until 02-03z this evening before decoupling with
speeds under 8 kts. A weak front back doors into northern portions
of the southeast plains late tonight and could bring a brief window
of southeast winds under 10 kts to KCOS and KPUB Sunday morning. But
as the front lifts back to the north...gusty south to southwest
winds will mix back down into KCOS by 18z...and into KPUB by 20-21z.
KALS will see winds increase from the south around 18z on Sunday.
All three taf sites could see gusts in the 25-30 kt range Sunday
afternoon. Otherwise VFR conditions expected. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...MOORE
AVIATION...KT
Area Forecast Discussion For Western SD and Northeastern WY
National Weather Service Rapid City SD
525 PM MDT Sat May 13 2017
.DISCUSSION...(This Evening Through Saturday)
Issued at 213 PM MDT Sat May 13 2017
Latest water vapor imagery shows an upper ridge centered over
western South Dakota with an upper low moving onshore over the
Pacific Northwest. There is a long wave trough extending southward
from the Pacific northwest low down to the Baja Peninsula. At the
surface, there is an area of low pressure just north of the Black
Hills with a cold front extending through central Wyoming and a
warm front along the North/South Dakota border. 19Z radar imagery
is showing the surface low in southern Meade County, just north of
Ellsworth, with the cold front and wind shift just northwest of
Rapid City. It is also showing the convergence boundary along the
eastern foothills where convection is anticipated to develop this
afternoon.
For this afternoon and evening, low level instability combined with
convergence along and the cold front and eastern foothills will
allow some showers and storms to develop. Models indicate cap this
afternoon first erodes over northeastern Wyoming and in the
central/southern Black Hills with MLCAPE around 1000 J/KG. RAP model
shows some energy at 700mb in the downstream convergence zone of the
Black Hills, but water vapor imagery indicates the main bulk of the
energy will be associated with the shortwave currently over northern
Wyoming that moves through southeastern Montana and southwestern
North Dakota overnight. Isolated strong to severe storms will be
possible with activity moving off the Black Hills and Bighorn
Mountains spreading into northeastern Wyoming and northwestern South
Dakota this evening. Given deeply mixed, but drier boundary layer,
the main threat will be gusty winds and marginally severe hail. The
cold front should move through most of the forecast area overnight.
On Sunday, models indicate the front will extend through central
South Dakota during the morning before moving well east by Sunday
evening. Temperatures will remain above normal behind the front, but
will be about 10 cooler than Saturday. Will see gusty northwest
winds behind the front continuing into the early afternoon hours,
especially across the western South Dakota plains.
A weak shortwave moves through Sunday night, with 250 J/KG of MUCAPE
available. This should allow a few showers/isolated thunderstorms to
develop, especially over southwestern and south central South
Dakota.
Southwest flow aloft will bring an active and unsettled pattern for
the upcoming week. For Monday through Wednesday, several upper level
shortwaves will move through the flow combining with the weak
diurnal instability to bring daily chances of showers and
thunderstorms. For Thursday and Friday, models continue to be in
good agreement bringing the upper low from the Rockies into the
northern Plains. Current track of the low would indicate the
forecast area would see beneficial precipitation with this system.
Temperatures over the higher Black Hills and Bear Lodge Mountains
indicate the possibility of snow. Will continue to watch this
closely. Overall, temperatures will be chilly for May by the end of
the week.
&&
.AVIATION...(For the 00Z TAFS Through 00Z Sunday Evening)
Issued At 520 PM MDT Sat May 13 2017
Scattered showers and thunderstorms will continue through the
evening hours across northeast WY and the Black Hills area. IFR
conditions are possible in and near any heavier showers. A cold
front will move east across the rest of the area tonight and bring
areas of MVFR cigs overnight, especially across northeast WY, the
Black Hills, and far northwest SD. Gusty northwest winds of 20 to
30 knots can be expected for a few hours after the frontal passage
overnight. VFR conditions should return to most locations by
Sunday morning after 14Z.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...None.
WY...None.
&&
$$
DISCUSSION...MLS
AVIATION...15