Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/31/20
Area Forecast Discussion
National Weather Service Bismarck ND
937 PM CDT Mon Mar 30 2020
.UPDATE...
Issued at 934 PM CDT Mon Mar 30 2020
A few showers linger across central North Dakota this evening, but
they should end by midnight. We lowered min temps across the east
about 2 degrees where temperatures have fallen more rapidly this
evening, otherwise current forecast looks ok.
UPDATE Issued at 622 PM CDT Mon Mar 30 2020
Weak convective showers were spreading into south central North
Dakota early this evening. Latest RAP model produces some cape in
this area, and the latest rawinsonde from 00z launch sees
adiabatic lapse rates up through 640 mb. Although the dewpoints
are pretty paltry, in the lower to mid 30s, we expect a brief
showers or thunderstorm chance this evening south central. Gusty
southeast winds this evening central and east will diminish a bit
after sunset. Winds will again increase to 25 to 30 KTS Tuesday.
&&
.SHORT TERM...(Today through Tuesday Night)
Issued at 210 PM CDT Mon Mar 30 2020
Forecast highlights in the short term period will be chance of
showers this evening, then weather associated with a cold frontal
passage Tuesday/Tuesday night.
Currently, embedded mid level wave lifting northeast across the
Northern Plains today, resulting in some mid level clouds. Tight
pressure gradient in place with high pressure east and developing
low pressure to our west across MT has resulted in breezy
south/southeasterly winds. Combined with weak WAA these mixing
winds have resulted in another mild day with temperatures across
west/central ND well into the 50s along with some low 60s already
early this afternoon. Thus far the low RH values forecast across
southwestern ND have not materialized. Though high res models do
indicate winds down there shifting to more southwest after 21Z,
and should result in the lower dewpoints across southeast MT to
advect into my southwest. Thus only a small window of near
critical fire weather conditions expected late today with winds
sub-marginal.
Increasing diffluent flow aloft this evening will combine with
increasing low level moisture and some weak mid level energy to
result in a chance for showers central and east. While moisture
increases, it is still limited along with weak MUCAPE, so will
not add thunder to the forecast at this time. The evening shift
can monitor to see if this changes.
For Tuesday, upper low moving into the Pacific NW Mon/Mon night
develops farther east into the Northern Rockies Tuesday daytime,
and will result in a trough of low pressure developing into the
far western Dakotas by early Tue aft. Sfc trough continues east
into central ND late Tue afternoon, then into eastern ND Tue
night. Still expect increasing chances for showers along to ahead
of the trough, especially late Tue afternoon/Tue eve when an
upper level jet streak noses into the region providing strong
upper level forcing via left exit region jet dynamics, coupled
with low/mid level forcing with the FROPA. This forcing is also
combined with a few hundred joules of MUCAPE and mid level lapse
rates 7C to 8C/Km. SPC did add our area into the general t-storm
outlook and did opt to add a slight chance of thunder late Tue aft
through Tue evening along the trough. 0-6km bulk shear is weak,
less than 25KTs, so the severe threat will be low if anything.
CAA spills into the west Tuesday night along with brisk northwest
winds central and west. Again increased winds above guidance as
the blend remained too low.
.LONG TERM...(Wednesday through Monday)
Issued at 210 PM CDT Mon Mar 30 2020
12Z models have again kept with the trend of the large upper low
remaining quasi-stationary over southwestern Canada, with a strong
S/WV trough rotating around it and being steered by the upper
level jet through Idaho and Wyoming Wed night, and then into the
Dakotas Thursday. The GFS remains farther south, and the ECMWF
more north. Blended guidance is favoring a more northerly track
closer to the EC. This puts 1-3" of snow from Bowman northeast to
Devils Lake, and to around 7" across the far southern James
Valley where forecast QPF is now around an inch. GEF plumes also
still showing a large spread with QPF so uncertainty remains high.
Will continue to monitor this period closely. Much colder
temperatures arrive as well, with high temperatures dropping into
the 30s and low 40s Wednesday through Friday.
Temperatures moderate for the weekend into Monday, and we also
remain in an active flow pattern for continued precipitation
chances.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 622 PM CDT Mon Mar 30 2020
At 6 pm CDT, a warm front extended from low pressure in southeast
Saskatchewan into central North Dakota. A cold front trailed from
the low into southeast Alberta. Scattered evening showers and an
isolated thunderstorm are possible in the south central, impacting
KBIS through 04z. Otherwise mvfr conditions and rain showers will
enter the picture across northwest North Dakota on Tuesday
afternoon as a cold front moves into the region.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...NH
LONG TERM...NH
AVIATION...WAA
Area Forecast Discussion
National Weather Service State College PA
1124 PM EDT Mon Mar 30 2020
.SYNOPSIS...
An upper trough will bring cooler and damp conditions to the
region for much of the week. Scattered light showers are
expected into Wednesday morning. On Wednesday, we`ll finally
see drier air arrive from north to south to scour out out the
clouds as the day wears on. Thursday through Saturday will be
dry, but a chance of showers may return late in the weekend.
&&
.NEAR TERM /UNTIL 8 AM TUESDAY MORNING/...
Clouds continue to creep into the SE, now with mtn wave clouds
extending into York Co. Another interesting night with low crud
creeping in from the east. Light wind in general, but there is
an indication of low stratus moving in to PA/DE/wrn MD out of
the E/S. We may see this trend continue with low level RH plots
from RAP and new NAM sliding some high RH air in at 925mb before
sunrise. This is a little faster than anticipated. Clouds will
keep the temps from falling more than a couple of degrees for
the rest of the night, even though the wind should die down. Air
does get cold enough in the clouds across the far nrn tier to
turn/mix the rain to SN. But, we are still not expecting
anything more than a dusting/coating on the high ground of the
north, mainly because the ground temp is above freezing and the
air will barely get to freezing.
Prev...
Showers continue across the nrn half of the area. Just a couple
of hundredths in spots as they pass by quickly. Only a few
breaks in between them, though. Gusty wind will gradually
lighten through the night.
Prev...
Upper trof and secondary cold front crossing into northeast Pa
this afternoon had isold lightning accompanying low topped
convective showers earlier on. Garden variety instability
showers are scattered about the northwest half of central PA and
will last into the evening before decreasing. Cooler air
filters over the Commonwealth tonight, as the filling upper low
and inverted sfc trof settle over the state. This will keep a
good deal of clouds and still some isold to sct v light showers
in the forecast. Highest elevations could be wet snow but not
expecting any accums given marginal temps and very light
intensity. Lows will range from the lower 30s northwest to the
lower 40s southeast.
&&
.SHORT TERM /8 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
Clouds stay in place Tuesday as filling upper low remains in
place. Isold to sct showers are once again expected...and have a
chance of being mixed with snow across the northern tier in the
AM. Isold to sct SHRA move back in from the east. Highs range
from the mid 40s north to the lower 50s south.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
An upper low over the northeastern US midweek will gradually
pull out over the North Atlantic Thursday into Saturday. A
narrow upper ridge axis will approach from the Midwest, before
flattening out just west of the Commonwealth, allowing some
northern stream shortwave energy and an associated cold front
to approach late in the weekend.
As for sensible weather, Wednesday will feature slightly below
normal temperatures and a few showers underneath the upper low.
Thursday through Saturday looks dry, as a surface ridge axis
extends southward into the area from a large eastern Canadian
anticyclone. Temperatures through this period will gradually
moderate with time. Our next chance of showers should arrive by
Sunday, tied to the approach of a weak cold front.
Bottom line, no major storms or anomalous temperature regimes
are foreseen for central PA over the next week or so.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
Late evening update.
Minor adjustments based on radar and observation trends.
Earlier discussion below.
For the 00Z TAFS, looking at CIGS to lower overnight, as the
airmass cools. Some showers, especially across the north early
on.
For Tuesday, expect conditions to slowly improve. Went with
VCSH in the TAFS, as inverted trough could trigger a few
showers.
.Outlook...
Tuesday night Wednesday...Mainly dry. Perhaps a brief shower.
Thursday...Improving conditions in northwest flow.
Friday...Chance of a shower across the northwest, otherwise dry.
Sat...Dry conditions with VFR conditions expected.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SYNOPSIS...Dangelo/DeVoir
NEAR TERM...Dangelo
SHORT TERM...DeVoir
LONG TERM...Jurewicz/Evanego
AVIATION...Martin
AREA FORECAST DISCUSSION...UPDATED
National Weather Service Jackson KY
1100 PM EDT Mon Mar 30 2020
.UPDATE...
Issued at 1100 PM EDT MON MAR 30 2020
Just a quick update to touch up the sky cover into the overnight
hours. Have also added in the latest obs and trends for the T/Td
grids which incorporates a small to moderate ridge to valley
split that will diminish toward dawn. These updated grids have
been sent to the NDFD and web servers.
UPDATE Issued at 740 PM EDT MON MAR 30 2020
23z sfc analysis shows weak high pressure quickly moving through
the state. Already the high clouds from the next system have
spread over the southern half of eastern Kentucky. Ahead of these,
enough sunshine helped temperatures rise into the mid 60s most
places despite general Cold Air Advection on west to northwest
winds to 10 to 20 mph with higher gusts. Now those winds are
starting to settle and with temperatures falling humidities have
climbed allowing the Red Flag Warning to be expired at 7 pm.
Temperatures currently are running in the upper 50s to lower 60s
with dewpoints holding in the upper 20s to lower 30s most spots,
but near 40 in the far southwest. The current forecast grids have
the situation well in hand with the increasing clouds and rain
chances arriving in the southwest after dawn - in line with the
latest NAM12 and CAMs. Accordingly, have mainly just tweaked the
sky cover going forward and added in the latest obs and trends for
the T/Td grids. These updates have been sent to the NDFD and web
servers along with an update to the HWO and expiration of the Red
Flag Warning.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 358 PM EDT MON MAR 30 2020
Dry conditions and low RH have developed this afternoon across the
area leading to near red flag conditions in some areas. These
conditions will slowly improve into the early evening hours, as
winds continue to subside. RH recovery may be a bit slower,
especially on the ridgetops. However, a shortwave trough to our
southwest will push east across the region late tonight and
Tuesday with a surface low tracking across the deep south.
Overrunning precipitation on the northern peripherals of this
system will develop late tonight and especially on Tuesday and
spread northward into east Kentucky. Should be a fairly tight
gradient in where the better rainfall does occur and some areas in
the northern portion of the area could stay dry. Still a bit of
uncertainty in the middle portions of the CWA on how far north
precipitation makes it. However, the best chances will reside
across the southern half of the forecast area and even the HRRR
has backed off on its earlier more southern solution. Thus, models
are starting to converge toward a general consensus, so
confidence is increasing where that northern edge of precipitation
could end up.
Precipitation will continue through the day before winding down
during the evening hours. Temperatures will be quite cooler,
generally in the 50s with the clouds and precipitation. Clouds
will hang tough Tuesday night and may even get some patchy drizzle
or light rain developing. For now, going to maintain the trend
towards drying weather, but rain chances may need to be added.
.LONG TERM...(Wednesday through Monday)
Issued at 358 PM EDT MON MAR 30 2020
Eastern Kentucky will start off Wednesday under an upper level
trough and may keep our skies cloudy through much of the day as
the shortwave ridge axis stays to our west during the day. In
fact, its entirely possible many areas stay cloudy into or through
Wednesday night as the ridge axis makes very little if any
progress to the east based on the 12z model guidance. If clouds
persist, that would keep us a bit milder for Wednesday night then
our current forecast lows.
We should finally see any lingering effects of the trough on the
way out on Thursday as the ridge finally sets up overhead making
for a pleasant end to the week for Thursday and Friday. Return
flow should set in for Saturday with milder conditions spreading
north. A shortwave trough will then push east Saturday night into
and across the region. This feature will be flattening out as it
crosses the region, so we would expect a weakening trend with this
feature. However, could be enough residual moisture and lift to
provide some showers as the feature crosses the area early Sunday.
The picture becomes muddled from Sunday onward as the spread in
the models goes way up. Thus, confidence is low from Sunday into
Monday. There is a chance precipitation chances could linger
through Sunday and into Monday, but there is also evidence of a
another drier period. With this all said, will maintain some low
pops into early next week given the degree of uncertainty.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
ISSUED AT 755 PM EDT MON MAR 30 2020
Higher clouds continue to stream in from the west ahead of a
developing wave of low pressure that will be tracking through the
Deep South over the next 24 or so hours. This system will produce
some light to moderate rain overspreading a good part of Kentucky
Tuesday morning. Thus VFR conditions expected through the first
half of period, though rain will affect our southern most
terminals along with some MVFR CIGs and VSBYs by mid morning,
Tuesday. Westerly winds will continue to slacken and become light
this evening then continue light and variable through the rest of
period.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...KAS
LONG TERM...KAS
AVIATION...KAS/GREIF
Area Forecast Discussion
National Weather Service North Platte NE
750 PM CDT Mon Mar 30 2020
.SHORT TERM...(This evening through Tuesday night)
Issued at 305 PM CDT Mon Mar 30 2020
Showers and isolated thunderstorms this evening will exit ncntl
Nebraska by 12z. The SREF and HREF suggest the potential for areas
of fog developing 09z-12z Tuesday morning and the RAP model shows
dry air moving in aloft which would support the necessary
radiation condition for development. The fog forecast uses the
SREF for areas of fog across the Sandhills and parts of southwest
Nebraska. The fog is expected to lift by 15z. Clearing skies are
expected Tuesday morning across wrn and ncntl Nebraska.
The temperature forecast tonight through Tuesday night uses the
guidance blend plus bias correction. Highs Tuesday were marked down
a degree or two to accommodate the disruption in daytime heating
caused by morning fog and cloudiness. No adjustment was made to lows
tonight or Tuesday night.
.LONG TERM...(Wednesday through Monday)
Issued at 305 PM CDT Mon Mar 30 2020
Arctic high pressure across nrn Canada will build to near 1065 mb
and begin spilling into Nebraska Wednesday afternoon. The models
have slowed the progress of this cold front allowing for a second
warm day Wednesday across srn Nebraska. The models are in fairly
good agreement producing near or post frontal showers and
thunderstorms Wednesday evening. By Thursday evening, temperatures
will be cold enough for snow and by Friday morning, wind chills
readings in the teens and single digits are in place.
Other than northwest Nebraska, none of the models are suggesting
significant winter weather and this is consistent with WPC and the
previous forecast. The models are showing a deep upper low forming
across western Canada and this is the basis for mid level
frontogenesis and rain Wednesday night followed by snow Thursday
night.
Today`s model runs show the upper low retreating north this weekend
and a trof forming off the West coast. A short wave ridge will form
ahead of the trof and this should send a surge of mild air into
Nebraska Sunday and Monday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 724 PM CDT Mon Mar 30 2020
Scattered light showers will end this evening. Later tonight lower
ceilings should develop across portions of the Sandhills into
southwest Nebraska, with patchy fog possible. These ceilings
should quickly lift Tuesday morning as winds increase from the
southwest.
&&
.FIRE WEATHER...
Issued at 305 PM CDT Mon Mar 30 2020
Elevated fire weather concerns the Frenchman basin. Humidity across
the Frenchman basin falls to around 15 percent Tuesday afternoon.
Wetting rain today and high humidity Tuesday morning could
disrupt the curring process Tuesday. Plus, there is evidence of
green-up along the roadways which could prevent fires from
spreading across state and county roads. Wind speeds in this area
predicted at 10 to 15 mph during the afternoon.
&&
.HYDROLOGY...
Issued at 305 PM CDT Mon Mar 30 2020
The river level on the Elkhorn river near Atkinson crested
below flood stage last night and is falling. Rainfall this afternoon
and this evening could cause a minor rise Tuesday. This rise is not
expected to produce minor flooding.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
SHORT TERM...CDC
LONG TERM...CDC
AVIATION...Taylor
FIRE WEATHER...CDC
HYDROLOGY...CDC
Area Forecast Discussion
National Weather Service Memphis TN
925 PM CDT Mon Mar 30 2020
.UPDATE...Evening Update.
The eastward progression of an upper level trough across the
Southern Plains has resulted in rain showers this evening across
the Mid-South. Rain will continue tonight through much of Tuesday.
Any convection overnight will be isolated and mainly confined to
portions of northern Mississippi. Current temperature readings
are generally in the 50s. Temperatures are already beginning to
cool slightly in areas of rain. Overnight lows will be in the
upper 40s to low 50s.
17
&&
PREV DISCUSSION... /issued 314 PM CDT Mon Mar 30 2020/
DISCUSSION...Surface analysis this afternoon places a warm front
along the Northern Gulf of Mexico. GOES-16 satellite trends
indicate southwest flow aloft over the Southern Plains and into
the Lower Mississippi Valley with subtle shortwaves embedded
within the mid-level flow aloft. This has resulted in the
development of rain showers across the Mid-South especially along
the TN/MS border.
Short term models including Convective Allowing Model Solutions
(CAMs) indicate rain showers should continue tonight into Tuesday
morning in association with an area of low pressure moving across
Central Mississippi. Some elevated instability may be present
later tonight into Tuesday over North Mississippi to produce an
isolated thunderstorm. These rain showers will gradually come to
an end later Tuesday afternoon/evening as high pressure and
shortwave ridging builds back into the Lower Mississippi Valley.
Long term models indicate southwest flow aloft will move back into
the region for next weekend into early next week. This will bring
continued shower and thunderstorm chances each day.
CJC
&&
.AVIATION...
00Z TAFs
An open upper level trof will lift from the southern plains to the
Ozark Plateau through 12Z. High-based -SHRA will continue through
the evening, with intensity of precip insufficient to lower CIGs
below VFR threshold during the MEM arrival push. Of note: area of
precip between LIT and MEM at 00Z was bright-banding - enhanced
reflectivity from melting snow aloft, around FL070.
A complex set-up for tonight, with warm advection (lift) ramping
up and enhancing the rainfall from the high-based (above FL060)
clouds after 06Z. MVFR deck likely at MEM by this point,
persisting through the overnight. IFR tendency will be offset by
drier near surface northeasterly flow, and reduction in lift and
rainfall rates after 10Z or so. NAM Bufr and RAP soundings
indicate a deepening and well-mixed frontal layer overnight,
making ceilings a bit of a challenge.
Lift exits after 12Z, dry northerly flow continues and the mixed
layer/ceilings increase on Tuesday.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&
$$
Area Forecast Discussion
National Weather Service Mobile AL
951 PM CDT Mon Mar 30 2020
.NEAR TERM /Now Through Tuesday night/...A stout upper trough and
cold front will bring the chance of storms Tuesday with a few
strong to possibly severe storms. For exact details on the severe
potential see the severe section below.
Tonight the upper trough is located over the Oklahoma and Texas
Panhandles and will continue to progress eastward. In response to
the strengthening upper trough, an expansive precip shield has
developed over the Arklatex region already. At the surface, a
weak stalled boundary extending from east Texas across our area.
The combination of synoptic lift from the right entrance region of
the upper jet streak, latent heat release from the ongoing
convection and the surface boundary will lead to a surface low to
develop somewhere over Lousiana. The location of the low
formation will likely be driven by the location of the ongoing
precip and the boundary. This area of low pressure will quickly
move northeast across central Alabama during the mid-morning hours
as the upper trough becomes positively tilted across the Tennessee
valley. As the low tracks to our north, the weak boundary will
also quickly surge northward bringing better moisture across our
area as dewpoints climb into the mid to upper 60s. Showers and
storms will likely develop across southeastern Mississippi during
the early morning hours. By mid-morning (9-10 am) storms will be
approaching southwestern Alabama and will continue to race
eastward across the area. Storms should clear the area by late
afternoon to early evening as the cold front clears our area
paving the way for "cooler" and drier weather.
With the close proximity of the surface low and good diurnal
heating, winds will be gusty out of the south quickly becoming
southwest by the afternoon. Some gusts up to 30 mph will be
possible and a wind advisory has been issued for tomorrow.
Temperatures will quickly rise into the upper 70s to low 80s
before cooling off behind the front.Lows Tuesday night will be in
the low 50s to upper 40s. BB/03
Severe...There is the potential for strong to severe storms with
the cold front tomorrow and the SPC has highlighted most of the
area in a slight risk. The best chance for severe weather will be
along and east of I-65 during the mid-day to early-afternoon time
frame with damaging winds the primary threat, hail up to quarter
size and a tornado cannot be ruled out. There area a few caveats
with this system in that 1. the upper trough, surface low and
synoptic forcing will be quickly moving out of the area and during
the diurnal minimum. 2. Since this system is on the heels of the
last weak system, deep moisture will be limited. Both of these
will likely cut down on the available instability given that most
of the instability will be driven by diurnal heating. Now there
will be ample shear with effective bulk shear values of around 45
knots and models are hinting at around 500 to 800 J/KG of MLCape
in the morning increasing to about 1000 J/KG by the afternoon. It
is important to note that the HRRR has been slightly quicker with
each run but also trending slowly upward with cape. Nonetheless,
the environment would be supportive of organized convection with
potential bowing segments and maybe a supercell or two. High-res
soundings do depict a rather dry mid-level and modest mid-level
lapse rates leading to damaging winds as the primary threat.
Given the weak forcing, storms may tend to remain more discrete
leading to maybe some larger hail in the stronger storms. The
tornado threat appears minimal due to quickly veering surface
winds. Hodographs are long but lack overall low- level curvature,
except further north closer to the surface low and warm front
where surface winds will remain southerly for longer. A tornado
cannot be ruled out in this area but overall the threat appears
low. BB/03
&&
.PREV DISCUSSION... /issued 638 PM CDT Mon Mar 30 2020/
NEAR TERM UPDATE /Now Through Tuesday night/...A vigorous mid level
short wave trof moving east of the Rockies this afternoon will
continue to track eastward over the middle part of the country
with a closed upper low developing just west of the mid MS River
Valley by 12z Tue then weakening and lifting out further to the
east over Western North Carolina by late Tue afternoon. Near the
surface a weak frontal boundary that moved off the coast over the
marine area this morning has weakened and has begun to lift
northward as the main upper system continues to approach from the
west. The weak boundary is progged to move inland this evening and
overnight as a warm front with most of the forecast area in the
warm section around sunrise Tue morning. South of the main upper
low a broad surface low develops over east TX this evening and
tracks east quickly reaching the central part of MS before sunrise
Tue then over central AL around sunrise or shortly after, moving
east of the AL/GA state line by midday. Most of the guidance
continues to show a 40 to 50 h85 jet traversing across central and
northern sections of the forecast area during the morning hours
on Tues combined with 125 knot upper streak just to the west. 0-6
bulk shear values still show values between 50 to 70 knots during
this time frame combined with surface based instability or CAPE
values ranging from 300 to 1200 J/kg occurring mostly over the
middle and eastern half of the forecast area also during this time
frame. As a result we will see good coverage of the showers and
thunderstorms moving into all western sections of the forecast
area before daybreak on Tue becoming better organized as they move
further east across most locations in the forecast area after
sunrise with the best chance for strong to severe thunderstorm
development occurring generally east of a line stretching from
Lucedale MS to Thomasville in Al, including most locations of
Mobile and Baldwin counties in AL and all locations in the western
Fl Panhandle during the morning and early afternoon hours.
Damaging straight lines winds...hail along with a few tornadoes
will be the main concern mostly during the morning and early
afternoon hours. Gusty southwest winds at 15 to 25 knots with
gusts to 30 knots are also expected during the morning hours on
Tue shifting mostly to the west by early to mid afternoon. As a
result a Wind Advisory is in effect for lower parts of the
forecast area during most of the daylight hours on Tue. Conditions
improve quickly later in the day on Tue generally from west to
east as the main upper system to the north lift outs quickly.
Temperatures will continue to be above seasonal norms this afternoon
and most of tonight returning to more seasonal levels in the wake of
the cold front that moves across the area by late Tue afternoon and
early evening. 32/ee
AVIATION...
00Z issuance...Observations and guidance suggest that VFR
conditions will persist through the night tonight with light
southerly winds at the coast. Southerly winds will spread
northward tonight as a weak warm front surges northward. With the
warm front, there appears to be a brief period of possible MVFR
cigs that will spread inland than quickly mix out by mid-morning.
A surface low will pass to our north tomorrow bringing a cold front
through the area. Along and ahead of the front showers and
thunderstorms will likely develop around mid-morning over
southeastern Mississippi and spread eastward clearing the area by
late afternoon. A few storms maybe strong to severe especially
along and east of I-65. Winds will be gusty tomorrow with wind
gusts to 25 knots or higher possible out of the southwest. Behind
the front, winds will quickly turn out of the northwest and slowly
diminish.
PREV DISCUSSION... /issued 409 PM CDT Mon Mar 30 2020/
NEAR TERM UPDATE /Now Through Tuesday/...A vigorous mid level
short wave trof moving east of the Rockies this afternoon will
continue to track eastward over the middle part of the country
with a closed upper low developing just west of the mid MS River
Valley by 12z Tue then weakening and lifting out further to the
east over Western North Carolina by late Tue afternoon. Near the
surface a weak frontal boundary that moved off the coast over the
marine area this morning has weakened and has begun to lift
northward as the main upper system continues to approach from the
west. The weak boundary is progged to move inland this evening and
overnight as a warm front with most of the forecast area in the
warm section around sunrise Tue morning. South of the main upper
low a broad surface low develops over east TX this evening and
tracks east quickly reaching the central part of MS before sunrise
Tue then over central AL around sunrise or shortly after, moving
east of the AL/GA state line by midday. Most of the guidance
continues to show a 40 to 50 h85 jet traversing across central and
northern sections of the forecast area during the morning hours
on Tues combined with 125 knot upper streak just to the west. 0-6
bulk shear values still show values between 50 to 70 knots during
this time frame combined with surface based instability or CAPE
values ranging from 300 to 1200 J/kg occurring mostly over the
middle and eastern half of the forecast area also during this time
frame. As a result we will see good coverage of the showers and
thunderstorms moving into all western sections of the forecast
area before daybreak on Tue becoming better organized as they move
further east across most locations in the forecast area after
sunrise with the best chance for strong to severe thunderstorm
development occurring generally east of a line stretching from
Lucedale MS to Thomasville in Al, including most locations of
Mobile and Baldwin counties in AL and all locations in the western
Fl Panhandle during the morning and early afternoon hours.
Damaging straight lines winds...hail along with a few tornadoes
will be the main concern mostly during the morning and early
afternoon hours. Gusty southwest winds at 15 to 25 knots with
gusts to 30 knots are also expected during the morning hours on
Tue shifting mostly to the west by early to mid afternoon. As a
result a Wind Advisory is in effect for lower parts of the
forecast area during most of the daylight hours on Tue. Conditions
improve quickly later in the day on Tue generally from west to
east as the main upper system to the north lift outs quickly.
Temperatures will continue to be above seasonal norms this afternoon
and most of tonight returning to more seasonal levels in the wake of
the cold front that moves across the area by late Tue afternoon and
early evening. 32/ee
SHORT TERM /Tuesday night Through Thursday night/...A much drier
northwest flow pattern aloft will return to the north central
Gulf Coast region Tuesday night into Wednesday as the upper level
trough moves eastward across the Mid-Atlantic states/Eastern
Seaboard and the adjacent western Atlantic. Shortwave ridging
aloft then builds overhead Wednesday night into Thursday, before
flattening slightly with potential for another weak shortwave
impulse to move into southeastern MS by late Thursday night.
Mostly clear and dry conditions look set to prevail across our
forecast area Thursday. A slight chance of rain showers may return
to southeast MS by late Thursday night as the next weak shortwave
impulse approaches the region. Northerly winds will otherwise
remain elevated across the area Tuesday night into Wednesday
morning as surface high pressure builds across the Mississippi
Valley region. The surface ridge will continue to advance eastward
over the area Wednesday and Wednesday night, before shifting
along the Eastern Seaboard by Thursday night.
Cooler temperatures are anticipated on Tuesday and Wednesday
nights with lows in the mid to upper 40s over most interior
locations, and in the lower 50s along the immediate coast. Highs
on Wednesday will finally be back close to normal or perhaps a
degree or two below normal in the upper 60s to lower 70s.
Temperatures will be slightly warmer in the lower to mid 70s on
Thursday. /21
EXTENDED TERM /Friday Through Monday/...Zonal mid level flow
generally continues across the forecast area Friday and Saturday.
Deep layer moisture remains fairly limited on Friday, but there
could be enough weak ascent for isolated showers, mainly across
western portions of the CWA. A shortwave impulse in the zonal flow
pattern may support a better chance of rain showers across the
region by Saturday. Embedded impulses in the flow aloft may
continue to move across the region Sunday into Monday on the
northern periphery of a ridge building across the Gulf of Mexico.
We will maintain a chance of showers and a few thunderstorms late
this weekend into early next week. Temperatures will likely be
above normal through the extended period. /21
MARINE...A strong southwest to westerly wind flow with building
seas will develop late tonight and on Tue ahead of a strong cold
front approaching from the west. Winds and seas will be locally
higher in and near showers and thunderstorms on Tue with some storms
possibly strong to severe. A strong northwest to northerly flow will
develop early Tue night and continue through Wed morning in the wake
of the cold front. Winds and seas will diminish late Wed and
continue through the end of the week as high pressure builds across
the southeast states and eastern Gulf. Seas will build to 5 to 8
feet Tue and Tue night then gradually subside late Wed through the
remainder of the week. Small Craft Advisories are in effect for Tue
through Wed morning. 32/ee
&&
.MOB WATCHES/WARNINGS/ADVISORIES...
AL...Wind Advisory from 9 AM to 7 PM CDT Tuesday for ALZ059-060-
261>266.
FL...Wind Advisory from 9 AM to 7 PM CDT Tuesday for FLZ201>206.
MS...Wind Advisory from 9 AM to 7 PM CDT Tuesday for MSZ078-079.
GM...Small Craft Advisory from 7 AM Tuesday to 10 AM CDT Wednesday
for GMZ631-632-650-655-670-675.
Small Craft Advisory from 9 AM to 8 PM CDT Tuesday for GMZ630-
633>636.
&&
$$
This product is also available on the web at:
http://weather.gov/mob
Area Forecast Discussion
National Weather Service Pueblo CO
304 PM MDT Mon Mar 30 2020
.SHORT TERM...(This evening through Tuesday)
Issued at 301 PM MDT Mon Mar 30 2020
Upper trough will exit eastern CO this evening with showers and
thunderstorms coming to an end. Dew point recovery across the far
southeast plains along east side of surface low has been slow to
recover with values lagging in the upper 30s. SPC meso-analysis
showing around 500 J/kg as of 20z. Deep layer shear is running
under 30 kts across the southeast corner. While a strong storm or
two is still not out of the question, model soundings show
convection will be rather high based given poor moisture return.
Some sub severe hail and wind gusts will be the primary threats late
this afternoon through early evening as cooling air mass aloft will
support some sufficiently steep lapse rates for hail and downdraft
wind production. Latest HRRR pushes stronger activity east of the CO
border by 00z with some lingering showers and thunderstorms across
the plains ending during the early evening.
Tuesday will be dry and warmer. There could be an hour or two of
near critical fire weather conditions along the southern border
counties in Las Animas/Baca Tuesday afternoon. As it stands, winds
look a little too light, so fire weather highlights do not appear
necessary. Temperatures will return to above normal. -KT
.LONG TERM...(Tuesday night through Monday)
Issued at 301 PM MDT Mon Mar 30 2020
Dry westerly flow aloft will be found over southern CO Tue night
thru Wed morning. Moisture is forecast to increase along the
Continental Divide Wed afternoon with precip expected to develop.
The rest of the area is expected to still be dry Wed afternoon.
Increasing west to southwest surface winds are expected Wed
afternoon in many locations, with gusts of 20 to 30 mph. At the
same time, RH values over southern portions of the plains, and over
portions of the San Luis Valley, are expected to be below 15%. Will
issue a Fire Weather Watch for these locations for Wed afternoon and
early evening. Temps will be above average on Wed, with highs in the
upper 60s to mid 70s along the I-25 corridor, in the upper 70s to
around 80 across the far southeast plains, in the 60s in the high
valleys, and in the 50s to lower 60s in Teller County.
Isolated to scattered showers are expected to continue over the mtns
along the Continental Divide Wed night, with dry weather elsewhere.
Light westerly breezes in areas are expected to help keep overnight
lows somewhat mild, especially near the mtns. On Thu and upper
disturbance will be moving across the Rockies in a broad upper trof
stretching from the Pacific NW across MT, WY and nrn CO. Early Thu,
a front is expected to move south into the southeast plains and by
afternoon easterly upslope winds are expected over much of the
plains. The exception looks to be over Huerfano and Las Animas
Counties, where breezy southwest to west winds are expected. RH
values over the southern I-25 corridor may be around 15% Thu
afternoon and will have to watch this area for potential high fire
danger. The San Luis Valley will also likely have breezy westerly
winds Thu afternoon, but at this time it looks like RH values will
be above 15% and therefore conditions will not be critical. Behind
the front Thu afternoon, the forecast models develop precip over
Teller County and El Paso County, and the central mtns look like
they will see high chances for precip. Precip chances are expected
to continue in these areas through Thu night. The GFS also develops
some light precip along the southeast mtns and I-25 corridor Thu
night.
Fri will be colder and there could be some isolated to scattered
showers from about the I-25 corridor and westward through the day,
but nothing significant. Sat looks a little warmer again, with some
isolated chances for showers still being possible, mainly over the
mtns.
Sun and Mon a new upper level weather system is expected over the
western U.S. but there is some uncertainty as to exactly how it will
all pan out. However, it does look like southern CO will see
increasing south to southwest winds, and the potential for some
critical fire weather conditions over the southeast plains and San
Luis Valley. There is also a small chance for thunderstorms over the
far southeast border area on Sun.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 301 PM MDT Mon Mar 30 2020
VFR cigs at the terminals will clear this evening as the system
exits the state. VCTS/VCSH will be possible at both KCOS and KPUB
through 00Z before activity pulls eastward. Gusty north winds will
continue at all three terminals through 01-02z then winds will
become light and variable overnight. Tuesday will be dry with VFR
conditions and light diurnally driven winds with speeds under 15
kts.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Wednesday afternoon through Wednesday
evening for COZ224-229-230-233-237.
&&
$$
SHORT TERM...KT
LONG TERM...28
AVIATION...KT
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Tuesday)
Issued at 354 PM CDT Mon Mar 30 2020
Precipitation chances for tonight continue to trend down from prior
forecasts as the uncertainty mentioned - in the form of dry air -
will likely continue to plague the short-term models and forecasts
causing lower overall confidence in all forecast solutions across
the immediate area.
A fairly compact, slightly amplified shortwave continues to track
east out of the Four Corners region into the Southern Rockies at
this hour. The amplification of this wave has helped the mid level
subtropical moisture advect and lift north into the area causing a
veil of mid level stratus over the area. Meanwhile much of the
subtropical energy remains south of the area and the main Westerlies
remain north of the area with an upper low spinning along the west
coast of Canada.
With the mid to upper level shortwave passing just south of the area
tonight, the best focus for overall lift also passes mainly south of
the area. Prior concerns that have been communicated related to how
much low level and even mid level dry air works back into the
northern portions of this system have caused a lower than ideal
confidence forecast. Much of the short-term of the HRRR and now the
HREF solutions have only continue to back off on the amount of
precipitation expected across the area. Therefore, even though I
have lowered POPs, they may still be too high and need to be lowered
further into the overnight period. Regardless, overall amounts of
any precipitation are anticipated to be low and there may only be a
few rumbles of thunder that cause some north central and east
central areas to see a couple areas of relative higher amounts but
any total amounts look to be about a half an inch or less.
A slight northerly breeze with some clouds early could lead to high
temps a couple degrees cooler overall than today in the mid to upper
60s. But, some western areas may be overcome by the return of a
southerly breeze into the afternoon and push back to around 70 once
again. As a result of quasi-zonal flow over the Rockies, overnight
lows should remain higher as well into the middle 40s.
.LONG TERM...(Tuesday night through Monday)
Issued at 354 PM CDT Mon Mar 30 2020
Into Wednesday, quasi-zonal flow regime continues which will support
a more developed lee-trough that will deepen into Wednesday and
Thursday time frame. As a result, have increased southerly winds
but may be a bit low at this point. Still not expecting advisory
level winds at this point. However, that is one area of the long
range forecast that could change if the broad upper Pacific trough
amplifies even a bit more than currently anticipated as it
translates into the northern Rockies thereby deepening the overall
pressure field responses.
A dry forecast is maintained into Wednesday and part of Thursday. By
late day Thursday, and through Friday, there are enough
discrepancies that have kept in slight to chance POPs for Thursday
afternoon with developing isentropic ascent and increased moisture
flux into the area. Extra lift with better forcing aloft associated
with the frontal boundary into Thursday night and Friday morning
allow for likely and definite POPs with at least a moderate level of
confidence. All indications appear that the best shear remains
behind the boundary and instability overall may be limited. So have
kept mention of the probability of hazardous weather is low for this
mid to long range period. Overall timing of the precipitation at
this point is a little uncertain related to how fast it passes east
of the area with dry air pushing into the region as modified
Canadian high pressure expands south. This may keep overall high
temps into the upper 50s on Friday.
Temperatures steadily rise into the end of the weekend as southwest
flow aloft sets up. Right now, ill timed shortwaves through the
mean flow and the return north of higher theta-e air are cause for
uncertainty in overall precipition chances, so only maintained
chance POPs through any portion of the weekend.
&&
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 640 PM CDT Mon Mar 30 2020
Stratus with VFR ceilings will overspread the terminals this
evening. Scattered showers will also develop after 2Z, with KMHK
having the better chance for rainshowers through the night. KMHK
may briefly drop below MVFR ceiling criteria if the light rain
showers are more widespread. The showers should end by 12Z TUE and
skies will slowly clear through the late morning and afternoon
hours.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Drake
LONG TERM...Drake
AVIATION...Gargan