Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/05/20
Area Forecast Discussion
National Weather Service Bismarck ND
911 PM CDT Sat Apr 4 2020
.UPDATE...
Issued at 911 PM CDT Sat Apr 4 2020
Latest surface map shows a general shift in the wind from southeast
to northwest from near Crosby to Tioga through Dickinson and Bowman.
This marks the location of a weak cold front which will slowly
edge east tonight before stalling over the northern James River
Valley Sunday. Minot radar shows scattered snowshowers over western
Ward County, edging closer to the city of Minot. This area of
precipitation will continue to shift east and dwindle through the
rest of the evening. RAP13 low level/925mb winds/relative humidity
forecast indicate a long enough duration of northwesterly winds
over north central North Dakota tonight to advect stratus and fog
from Saskatchewan across the border. Thus have added areas of fog
north with stratus pushing across the border 06z-19z Sunday.
UPDATE Issued at 537 PM CDT Sat Apr 4 2020
Latest water vapor imagery shows a negatively tiled shortwave
trough stretching from south central Saskatchewan into
northwestern North Dakota. Large scale ascent focused primarily
north and into Canada. Weak cold frontal system in western North
Dakota will steadily move east overnight. Regional radar shows a
narrow line of developing showers along this front, and have
extended the previous PoPs farther south (per RAP and HRRR) and
mentioned isolated to scattered coverage. SPC mesoanalysis shows
surface based cape around 100 J/kg in the west with mid level
lapse rates of 8.5 C/Km. RAP BUFKIT sounding for Watford city
suggests that a low top thundershower is possible in the next hour
or two. Although a lightning strike or two is possible, will not
add this to the grids as coverage and duration will be very
limited.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 224 PM CDT Sat Apr 4 2020
For tonight, we expect low pressure and an associated warm frontal
boundary to move east from Montana through North Dakota. This will
be the focus for small chances of rain and snow showers across
south central North Dakota ahead of the warm front, and across
north central North Dakota, along the trough axis of the low.
Overall we expect light to trace amounts of precipitation tonight.
On Sunday, a redeveloping lee side low pressure in Montana will
quickly return a southerly flow of air into the region. Another
chance of rain is expected along and north of the frontal boundary
across south central North Dakota Sunday afternoon. Again, only
light precipitation is expected.
With some more clouds tonight than last night, lows will be in the
teens and lower 20s, with highs Sunday in the 40s to lower 50s.
.LONG TERM...(Sunday night through Saturday)
Issued at 224 PM CDT Sat Apr 4 2020
For the extended period we will see a warmup into the 40s and 50s
Monday and 50s to lower 60s Tuesday as an h500 flow ridges across
the central and northern plains east of a western h500 trough off
the west coast. The milder air and a very modest amount of CAPE
will support some widely scattered thunderstorms across the south
central and east Monday afternoon, Monday night into Tuesday
morning. With dewpoints only in the lower to middle 40s, weak,
possibly elevated storms can be expected.
The mildest day of the week should be Tuesday, with highs in the
50s to lower 60s. Cooler air will then be seen for Wednesday and
Thursday, moderating a bit for Friday and Saturday. Northwest
flow aloft should bring in some shortwave energy and low chances
for rain and snow Friday and Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 537 PM CDT Sat Apr 4 2020
A weak cold front will shift from the west into central North
Dakota tonight before stalling over the northern James River
Valley late tonight through Sunday. Isolated to scattered
rain/snow showers expected this evening from KXWA to KMOT. VFR
cigs are expected for all terminals with the exception of KMOT,
where MVFR cigs are anticipated through 08z followed by IFR cigs
08z-19z Sunday.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...WAA
AVIATION...KS
Area Forecast Discussion
National Weather Service Cheyenne WY
910 PM MDT Sat Apr 4 2020
.UPDATE...
Issued at 908 PM MDT Sat Apr 4 2020
Our inherited forecast for tonight looks to be in good shape, so
have made only some minor changes to the winds for the rest of the
night.
&&
.SHORT TERM...(This evening through Sunday)
Issued at 229 PM MDT Sat Apr 4 2020
Bumped up temperatures for this afternoon for an update,
particularly along the North Platte River Valley. Torrington,
Scottsbluff, and areas near Sidney had reach the forecast high, or
were very close to it by 19Z while working on the newest forecast
patch. Diurnal cumulus has begun to pop up across southeast WY
early this afternoon. An occasional wind gust due to virga may
occur across the forecast region because of the evaporating light
rain sprinkles/showers that may develop. HRRR and Nam Nest Hi-resolution
guidance hints at weak shower activity this afternoon through
approximately sunset. The remainder of the forecast region looks
on par with current afternoon max temps. Despite cloud cover
staying minimal overnight, lows shouldn`t dip too far below
freezing except for the higher terrain mountain zones. South to
southwest winds will continue overnight to assist with warmer air
getting infiltrated into the region.
.LONG TERM...(Sunday through Friday)
Issued at 255 AM MDT Sat Apr 4 2020
Quiet weather expected heading into early next week with the
warming trend continuing. High temperatures will reach the 60s for
much of the CWA Sunday through Tuesday with portions of the
Nebraska Panhandle reaching the 70s early next week. A weak
impulse passes through the area Sunday afternoon and evening which
could result in isolated rain showers along and east of the
Laramie Range. An isolated thunderstorm cannot be ruled out as
models, including NAMNEST, depict ~500 J/kg of MLCAPE in place
over the northern Nebraska Panhandle through 03z Monday.
Heading into Monday, additional impulses spinning off the upper
low digging down the Pacific Coast will bring chances of precipitation
to areas west of the CWA along with a 700 mb jet of 40-45 kts over
Carbon County. Areas near Arlington/Elk Mountain could see gusty
winds during the day. As these shortwaves begin to pass more over
the CWA early Tuesday, winds turn westerly and increase over the
Laramie Range where strong subsidence develops by 12z Tuesday.
Cloud cover over western portions of the CWA could enhance the lee
trough and therefore increase ARL-BRX MSLP gradients. High winds
are not expected at this time, however strong gusts to 45 MPH are
possible Tuesday morning and afternoon near Bordeaux. Additionally,
dry downslope winds could further lower relative humidities over
the adjacent plains where forecast parameters are already
approaching red flag criteria.
As of right now, the GFS and Euro still lack any agreement with
the eastward progression of the upper level low over the Western
US once interaction begins with the subtropical jet over Baja
California. The GFS is still being more progressive and also dives
a trough located over the Northern High Plains much farther south
than the Euro suppressing most of the system`s energy well south
and east of the CWA. The 00z Euro has made significant changes
with the low track compared to recent runs keeping the low well
south of the Four Corners area. Precipitation chances with this
system late next week are on the decline, but we could still be in
store for a brief period of below average temperatures.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 526 PM MDT Sat Apr 4 2020
VFR category expected through tonight into Sunday. Expect winds to
become a bit breezy by late morning Sunday, but otherwise no
concerns to aviation.
&&
.FIRE WEATHER...
Issued at 229 PM MDT Sat Apr 4 2020
Recent precipitation over the area over the last 48 hours will
allow relative humidity values to stay elevation near and above
20% Wind gusts are anticipated to stay below 25mph this afternoon
and overnight, with occasional higher gusts in the wind prone
areas along I-80.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...None.
NE...None.
&&
$$
UPDATE...RUBIN
SHORT TERM...BW
LONG TERM...MB
AVIATION...JG
FIRE WEATHER...BW
Area Forecast Discussion
National Weather Service Grand Forks ND
926 PM CDT Sat Apr 4 2020
.UPDATE...
Issued at 926 PM CDT Sat Apr 4 2020
Mid level cloud cover continues to push through the FA, with some
clear spots behind it over central and western North Dakota. The
regional radar loop shows a few echoes around Minot, but not sure
how much of this is reaching the ground either. No changes are
planned with this forecast update.
UPDATE Issued at 646 PM CDT Sat Apr 4 2020
Quite a bit of mid level cloud cover is shifting across the FA
right now. There are even some weak echoes on radar. This is
associated with a weak 850mb jet, broad warm advection, and even
some upper jet support. So mostly expecting some virga tonight,
doubt if anything will actually reach the ground. There may also
be some partly cloudy breaks by late evening and overnight.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 259 PM CDT Sat Apr 4 2020
Area of mid clouds likely associated with 850-700 mb warm
advection is moving slowly northeast. Echoes remain moving toward
Jamestown. Obs have not shown any precipitation reaching the
ground, but radar returns would indicate at least something would.
More likely brief light snow. Will continue a low mention of -sn
into areas around Valley City late aftn and then weaken it.
Otherwise next short wave moving ENE thru S Saskatchewan and this
will track mostly north of the border tonight. Will maintain a
very low pop for -sn along the border per prev fcst. HRRR
ensembles maintain a small chance. Otherwise southeast to turn a
bit more south-southeast tonight as warmer air does move in.
Therefore not a large temp drop tonight.
Sunday will see the mid clouds move east, and warm advection
continues. But in the thicker snowpack kept highs on the lower
side of guidance, in the low 40s. Low 50s more likely far east and
southeast. Next short wave will move across the area Sunday night.
There has been a consistent signal for 850-700 mb warm advection
with this second wave and an area of light rain. Focus is on the
central parts of the fcst area. Rain amounts do look
light...mostly under 0.10 inch on average. Temps do look to stay
warmer than 32F during the precipitation.
.LONG TERM...(Monday through Saturday)
Issued at 259 PM CDT Sat Apr 4 2020
Milder on Monday but still cool in the northern fcst area with
40s. 50s to around 60 far south closer to a surface to 850 mb warm
front that will develop near the South Dakota border. Low pressure
will develop along the front associated with a 500 mb short wave
Monday evening. 850 mb warm advection and a 30 kt 850 mb jet will
focus a warm 925-850 mb layer into far SE ND and WC MN by 06z Tue.
MUCAPES via 12z GFS soundings show 500-800 j/kg. It would appear
that showers and a few t-storms will develop Monday evening nearer
just north of the warm front near I-94 and then the 850 mb jet
will turn more southwest and the instability by later Monday night
focus more over our far eastern fcst area and eastward from
there. So potential remains for an area of showers, esp central
and south, with risk of a few t-storms. Outside chance of a few
stronger t-storm provided steep lapse rates above 850 mb. Good
news is this precipitation will be progressive and overall
increasing in area as it moves more east of the immediate Red
River thru MN. Average rainfall amounts of 0.15 to 0.35 seem
reasonable, but with pwats over 0.75 inch some isold heavier
totals likely...but thinking they will be localized. Still
something to monitor for any hydro impacts.
Colder air will move down mid to late week. 850 mb temps crash
back down to -10 to -13C Wed night thru Friday. Some light
precipitation possible in the colder air, mostly flurries or
sprinkles. Temps should be below normal the second half of the
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 646 PM CDT Sat Apr 4 2020
Not seeing any issues for the TAFs until very late in the period,
when ceilings begin to lower again. This will probably appear
more on the 06z set of TAFs.
&&
.HYDROLOGY...
Issued at 300 PM CDT Sat Apr 4 2020
The rivers were generally steady or slowly falling on both the North
Dakota and Minnesota tributaries. A secondary rise is expected next
week when the recent snowfall melts.
The forecast points on the main stem Red River were generally steady
or slowly falling from Halstad southward. The forecast points north
of Halstad continue to rise. A secondary rise is expected next week
for the southern forecast points when the recent snowfall melts.
Harwood and the West Fargo diversion could go to major flood stage
next week. A secondary peak may be possible beyond the 7 day period
for the northern forecast points.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...None.
MN...None.
River point flood warnings continue across portions of
the region. Refer to the latest flood warnings and statements for
detailed information on specific locations.
&&
$$
UPDATE...Godon
SHORT TERM...Riddle
LONG TERM...Riddle
AVIATION...Godon
HYDROLOGY...JK
Area Forecast Discussion
National Weather Service Lincoln IL
733 PM CDT Sat Apr 4 2020
.SYNOPSIS...
Issued at 645 PM CDT Sat Apr 4 2020
Partly to mostly cloudy skies will be observed across central and
southeast Illinois tonight. A few light showers will be possible
along and south of an Effingham to Paris line this evening,
followed by dry conditions for the remainder of the night. Low
temperatures will mainly be in middle to upper 30s...with a few
lower 40s south of I-70.
&&
.UPDATE...
Issued at 733 PM CDT Sat Apr 4 2020
00z/7pm IR satellite imagery continues to show a low overcast
along/east of a Bloomington to Taylorville line...with mostly
clear skies further west across the remainder of the KILX CWA.
N/NE boundary layer winds will keep the clouds essentially in
place over the next few hours before clearing taking place across
northeast Illinois works its way into the area from the northeast
later this evening. Based on satellite trends and latest HRRR
forecast, the low clouds will gradually clear from northeast to
southwest overnight: however, an area of mid/high clouds currently
over northern Missouri and southern Iowa will track eastward at
the same time. End result will be partly to mostly cloudy
conditions across the board overnight. Low temperatures will range
from the lower 30s northwest of the Illinois River where skies
will remain mostly clear this evening...to the lower 40s south of
I-70 where clouds will be slowest to depart.
&&
.SHORT TERM...(This evening through Sunday)
ISSUED AT 330 PM CDT Sat Apr 4 2020
A cold front had pushed se into nw Ohio and into central KY/TN.
1024 mb high pressure over MN was ridging southward into IA and
MO and helping clear the low clouds along and nw of the IL river
at mid afternoon. Cool temps ranged from the low to mid 40s over
the heart of central IL se of the IL river (39 at Pittsfield and
Mount Sterling), to 51 at Galesburg and 50 in Lacon where sunny
skies prevailed. NNW to NW winds 7-15 mph giving wind chills in
the low to mid 30s over heart of CWA.
A weak disturbance moving into the mid MS river valley is bringing
scattered light rain showers to southeast parts of IL/MO and into
central IN. These light showers should gradually diminish in
southeast IL during this evening. Though a few models show very
isolated light showers over southern 6 counties possible overnight
into Sunday, but have elected to keep CWA dry overnight and Sunday
as better forcing further south of area. Low stratus clouds
decrease further se over central IL during this evening, while
some mid level clouds around 10k ft track eastward over area later
this evening and overnight, and decrease from west during early to
mid Sunday morning. Lows tonight in the mid 30s over central IL
from I-72 north and lower 40s in southeast IL from I-70 south
where low clouds linger longer. Skies become mostly sunny over
northern CWA Sunday and become partly sunny in southeast IL by
Sunday afternoon. Highs Sunday in the upper 50s in central IL and
lower 60s in southeast IL.
.LONG TERM...(Sunday night through Saturday)
ISSUED AT 330 PM CDT Sat Apr 4 2020
Clouds to increase from the west/sw during Sunday night ahead of
an approaching warm front to our sw. Lows Sunday night in the
lower to mid 40s, and mildest in sw CWA. Upper level ridging into
IL by Monday morning while a warm front lifts up across central
IL. Most models showing some qpf over northern/nw half of CWA on
Monday where have a chance of showers and thunderstorms. Better
chance of showers and thunderstorms Monday night across CWA and
have convection becoming more isolated to scattered on Tuesday in
central and eastern IL. Milder highs in the upper 60s and lower
70s Monday. Lows Monday night in the mid to upper 50s. Warm highs
in the mid to upper 70s Tuesday. Increased instability and wind
shear on Tuesday could lead to some stronger thunderstorms. SPC
does not have any outlook areas yet for Tue but bears watching for
Tue afternoon/evening. A weak front passes thru area Tue night and
keeps chances of convection going. Another warm day Wed with
highs around 70 northern CWA and mid 70s in southeast IL.
A stronger cold front passes se thru central IL Wed night bringing
a chance of showers and isolated thunderstorms, with models
trending higher with pops and qpf over area then. Much cooler on
Thu in wake of cold frontal passage with highs in the lower 50s
central IL and mid 50s southeast IL. 12Z models agree with a
large/strong mid/upper level trof digging into the Midwest and
eastern States late next week, bringing below normal temps Thu
thru Sat. Have slight chance of light showers overnight Thu night
and Fri with this trof. Cool highs Fri in the upper 40s/lower 50s
and low to mid 50s next Sat. Lows in the low to mid 30s Thu and
Fri night in central IL and as growing season expands northward,
part of area may eventually need frost/freeze headlines later next
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 645 PM CDT Sat Apr 4 2020
MVFR ceilings persist along/east of a KBMI to KSPI line early this
evening. While N/NW boundary layer winds were gradually pushing
the low clouds away from the central Illinois terminals during the
afternoon, winds veering to N/NE are now causing the clearing
line to stall and even retrograde slightly to the west. With
plenty of clouds noted on upstream satellite imagery as far
northeast as KJOT, it appears MVFR will hold firm at
KBMI/KDEC/KCMI through the evening. HRRR depicts low clouds
spilling back southwestward into KSPI by around 04z, and this
seems reasonable based on satellite trends. Clearing has taken
place over Lake Michigan into the Chicago metro area and the HRRR
shows this drier air working into central Illinois from the
northeast later this evening into the overnight. Have therefore
removed MVFR ceilings at KBMI by 05z...then further southwest to
KSPI by 11z. Despite the loss of low clouds, a large area of mid-
level clouds at around 10,000ft will spill across central Illinois
from the west tonight into Sunday morning. Once these clouds
skirt off to the east, skies will become partly to mostly clear
across the board after after the 15-19z Sun time frame.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Barnes
SYNOPSIS...Barnes
SHORT TERM...07
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
National Weather Service Jackson KY
1155 PM EDT Sat Apr 4 2020
.UPDATE...
Issued at 1155 PM EDT SAT APR 4 2020
Issued an update to the forecast to input the latest observations
and trend them into the overnight hours. Adjusted a few temps for
the ridge to valley split. Most places will not get quite as cold
as the previous morning as cloud cover slowly working into the
area will hinder this. Only a few minor tweaks were made to slow
up pops as the dry air in place will keep precip from arriving a
bit later.
UPDATE Issued at 735 PM EDT SAT APR 4 2020
Updated the forecast to input the latest observations and trend
them into the overnight period. Some clouds rolling in later
tonight will hinder ridge to valley temperatures differences a bit
but we will still be looking at some significant splits.
&&
.SHORT TERM...(This evening through Sunday night)
Issued at 431 PM EDT SAT APR 4 2020
The 20z analysis shows a weakening ridge axis extending from the
Tennessee Valley northward over Southwestern Ontario province to
near James Bay. Meanwhile, a dampening 500mb trough is shifting
eastward toward the Mississippi Valley further suppressing the
upper-level ridge. As a result, flow will trend nearly quasi-zonal
tonight but gradual height rises return tomorrow as weak ridging
rebuilds northward from the Gulf of Mexico.
At the surface, the high pressure ridge that has been our friend
over the past couple of days, has nearly disappeared while a
weakening cold front is now draped across central KY. An inverted
surface trough is developing across the western CWA, intersecting
the front near the Ohio River. Models are in decent agreement that
the the front will become nearly stationary tonight while pieces
of weak vorticity ride through the flow aloft. The GFS and NAM
both depict a weak surface circulation forming along the front
late tonight before pushing through the CWA during the daylight
hours Sunday. The front and any weak surface circulation exit to
the east Sunday evening as weak surface high pressure edges south
from the Great Lakes Sunday night.
In terms of sensible weather, clouds will continue to increase
this evening, which should keep temperatures a good 4 to 8 degrees
warmer than last night, generally ranging from the mid 40s in
eastern valleys to low 50s over the west and thermal ridges. The
dew points will also higher tonight, which could allow for some
patchy fog formation near lakes and larger rivers. A few light
showers are possible after midnight, particularly west of I-75 and
north of I-64, closer to the meandering cold front.
The frontal boundary, and any weak surface low-type circulation
will push through tomorrow, keeping plenty of clouds around along
with the potential for a few showers. The GFS builds up
150-300 J/kg of MLCAPE while NAM and HRRR suggest at least twice
that amount. Given the weak ridge building to our west over the
Mississippi Valley, the lack of significant forcing and the
relative dry low-levels, most convection should not become strong
enough for thunder. Convective shower chances will be highest
over the northern and eastern counties closer to marginally better
forcing. Temps should also be 2 or 3 degrees cooler than today
due to the cloud cover and slightly cooler air mass. High
pressure edging in from the north should put an end to any
lingering shower activity Sunday night. However, lingering low-
level moisture will keep plenty of clouds around through the night
and some fog development is possible where showers occur.
.LONG TERM...(Monday through Saturday)
Issued at 258 PM EDT SAT APR 4 2020
The models remain in general agreement with an amplifying long
wave pattern to control across the CONUS next week. Split-flow
will be in place, with a deeper upper level low to move south,
riding the West Coast through early Wednesday, before turning
landward across the Baja of California region. The models differ
with the speed and influence of this southern stream system for
the latter half of the extended, as the ECMWF keeps the bulk of
the energy held back, while the GFS is much more progressive.
Meanwhile, zonal flow will initially reside across most locations
east of the Rockies through the middle of next week, before the
northern stream lends strong influence. A vigorous short wave
trough will dig across southern Canada and cutoff as it dips just
north of the Saint Lawrence River Valley. By early next weekend,
colder cyclonic flow will be in place across much of the eastern
CONUS. Did not deviate much from the blended guidance this go
around, as confidence is not any higher for the latter half of the
period.
A developing warm front to our west will lift north of the Ohio
River Monday into Monday night, with rain chances increasing
across the area, although given the generally more modest mid and
upper level support, PoPs have trended a bit lower through this
time frame. Rain chances ramp up Tuesday into Wednesday, as better
moisture advects into the area, along with the eventual approach
and passage of a surface cold front. Another cold front will pass
through on Thursday, bringing an uptick in rain chances. High
pressure will then gradually build in across the Ohio and
Tennessee valleys Friday into Saturday, with generally drier
weather expected. Temperatures will average well above normal
through the middle of next week, with highs mainly in the 70s and
lows in the 50s. Readings will then cool off to below normal by
Friday and Saturday, with highs retreating to the 50s, and lows in
the 30s and 40s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
ISSUED AT 740 PM EDT SAT APR 4 2020
Expect VFR conditions through the TAF period with the exception of
a few wisps of fog in SME. This may result in a brief period of
MVFR conditions. Expect mid to upper level cloud cover moving in
through the night. Winds will be light and variable through the
period. A weak disturbance moving through will allow for a few
showers to develop but they will mainly be isolated.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...GEERTSON
LONG TERM...GEOGERIAN
AVIATION...SHALLENBERGER
Area Forecast Discussion
National Weather Service Midland/Odessa TX
632 PM CDT Sat Apr 4 2020
.DISCUSSION...
See 00z aviation discussion below.
&&
.AVIATION...
Low ceilings are expected to remain over MAF and redevelop and
move over HOB and INK this evening/tonight. VFR conditions are
expected by 18z Sunday for all terminals. Winds will generally be
out of the east to south with winds increasing around 20z Sunday.
&&
.PREV DISCUSSION... /issued 245 PM CDT Sat Apr 4 2020/
DISCUSSION...
Area radars show convection that developed overnight and this
morning exiting the upper Colorado Rvr Valley on a shortwave moving
into central Texas, having dropped just under an inch of rainfall in
isolated parts of the Permian Basin. Going into tonight, the HRRR
brings another shortwave into the Big Bend area, bringing convection
across the river late this afternoon and into tonight. Sfc flow
will continue veering to the east this afternoon, and then to return
flow around 00Z Sun or so. Once this transpires, a warm front will
move north overnight, resulting in patchy fog developing across the
lowlands. Otherwise, this afternoon is a reminder that spring is
not solidly established across West Texas and Southeast New Mexico,
w/expected highs in the NE zones over 25F below normal.
Fortunately, w/the resumption of return flow overnight, temperatures
will make a modest rebound to just below normal Sun afternoon. The
warm front will continue pushing north during the day, w/isolated t-
storms possible along/east of this feature.
Meanwhile, a closed system off the OR/CA coast will continue digging
south, increasing SW flow aloft over the region. Leeside troughing
on the Front Range will induce westerly downslope winds Mon
afternoon, resulting in temperatures climbing to above-normal and
sharpening up a dryline, along and east of which will be a window
for convection into Monday night. Monday may be the best chance for
rain this forecast, before west winds scour moisture/rain chances
east Tue. Models bring a 70kt mid-level jet around the base of the
trough and bring it thru West Texas, developing deep-lyr shear of 65-
70kts over the Big Bend/lwr Trans Pecos Mon afternoon/evening. If
mid-lvl lapse rates steepen up a bit, Mon afternoon/evening may be a
candidate for severe wx, and will need to be monitored.
Temps soar Tue/Wed, w/Wed being our warmest day thru next
week. At around 12Z Wed, the west coast trough begins to move
onshore near the CA/Baja border, while another trough moves thru
Canada just north of the CONUS, and drops a strong cold front into
the region Thu. This is much stronger than 24 hrs ago, as reflected
in latest MOS numbers. Once again, long-range models differ in how
fast they bring the west coast trough inland, w/the GFS bringing it
to ern NM by 18Z Thu, while the Canadian/ECMWF lag in AZ. Height
falls ahead of this system will result in a chance of convection
over the east Wed evening, but instability quickly diminishes as the
front moves in, w/-SHRA transitioning to rain Thu night-Fri night.
Temps bottom out Fri afternoon, but attempt a recovery Sat,
w/isolated convection possible ern zones Sat afternoon.
&&
.PRELIMINARY POINT TEMPS/POPS...
Big Spring 46 75 58 80 / 10 10 20 20
Carlsbad 45 80 55 80 / 0 0 10 10
Dryden 53 74 60 83 / 10 20 20 30
Fort Stockton 51 79 59 81 / 10 10 10 20
Guadalupe Pass 46 70 52 69 / 0 0 10 10
Hobbs 43 76 54 78 / 0 0 10 10
Marfa 47 75 50 75 / 0 10 20 20
Midland Intl Airport 47 76 58 81 / 0 10 20 10
Odessa 47 77 58 81 / 0 10 20 10
Wink 47 80 57 81 / 0 0 10 10
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...None.
TX...None.
&&
$$
99/99/99
Area Forecast Discussion
National Weather Service Marquette MI
631 PM EDT Sat Apr 4 2020
.SHORT TERM...(This evening through Sunday)
Issued at 359 PM EDT SAT APR 4 2020
WV imagery and RAP analysis indicated mid/upper level troughing
from Northwest Territories and northern Alberta into northwest
Ontario. A shortwave trough and cold front that supported pcpn
over the east this morning has moved east of the area leaving
lingering clouds east of P53-ESC. Although high pressure building
into the area has brought clearing skies, sunshine in the cool
airmass has only boosted temps into the low and mid 30s north to
around 40 south.
Tonight, High pressure settling over the area with clear skies,
light winds and PWAT values to around 0.10 inch will result in very
favorable radiational cooling. Expect inland min temps near the low
end of guidance with readings from around 10 in the typical cold
spots to around 20 closer to the Great Lakes.
Sunday, weak WAA along with abundant sunshine will push temps inot
the upper 40s north and east to the mid 50s southwest given 850 mb
temps to -1C and mixing through 4k-6k ft. Dewpoints should also fall
off to around 10F with RH values to around 20 percent.
.LONG TERM...(Sunday night through Saturday)
Issued at 356 PM EDT SAT APR 4 2020
Models suggest a positive height anomaly and associated ridge across
the N Pacific this morning will slowly weaken and shift E into the
beginning of next week. As a trough forms across the West Coast in
response to this ridge, it digs south towards the desert SW and will
become a cutoff feature by Tuesday night as a split-flow pattern
develops across the CONUS. The northern stream will dominate the
Great Lakes region through the mid-week, but models suggest these
two features will congeal towards the end of week with widespread
troughing and negative height anomalies expected across much of the
CONUS by next weekend. This idea is depicted similarly in both the
deterministic and ensemble medium range models. Above normal
temperatures are expected through the middle of next week with
ridging building in on Monday into Wednesday morning, before models
show a shortwave passing through on Wednesday bringing widespread
precipitation chances and a cooldown into the weekend.
On Sunday night into Monday, high pressure will be in play across
the Great Lakes region with dry, but cloudy weather expected through
early Monday morning. Upstream, a shortwave embedded in the northern
split-flow stream passes through the Rockies and into the Dakotas by
Monday evening. At the same time, a ridge is building into the Upper
Midwest with associated WAA and isentropic ascent. Models suggest a
rather tight gradient in the isentropes, but vary slightly in
associated wind magnitudes at the respective levels. Given the
Pacific origin, PWAT values are not anything to write home about,
with models suggesting 0.5 to 0.75 inches across the UP. The best
forcing remains off into WI, but there still remains a chance of
rain across the UP Monday morning into Monday night. The best
chances, however, look to be west and along the WI state line with
the chance of some mixed precipitation right away in the morning and
again at night.
The next chance of precip comes Tuesday into Tuesday night as a
shortwave trough ejects along the northern portion of the flow. An
area of low pressure develops and lifts from the Dakotas over Upper
Michigan. Southerly flow ahead of this system will bring an increase
of theta-e advection as NAM and GFS suggest some CAPE moving into
the region. NAM keeps most of this CAPE to the south through WI, but
the GFS does bring a few 100 J/kg into the UP along the WI border,
so I have included some thunder chances into the forecast.
Otherwise, expect widespread rain showers across the CWA on Tuesday,
tapering off from west to east in the evening. With PWATs nearing
0.75 inches, models are suggesting the potential for up to a 0.5
inch of rain across the CWA. Models show some differences with the
GFS remaining fairly consistent with the majority of the precip just
to the north over Lake Superior and another batch off the south
downstate. The GEM has remained fairly consistent just to the south
of the GFS across the central UP, with similar amounts. Will need to
wait another 24 hours to get a better sense of where things really
line up so PoPs and QPF are fairly broad-brushed.
As the cutoff feature across the SW moves on shore and over the
desert SW, another trough approaches the UP Wednesday
afternoon/evening. There is not much return flow between the
systems, but models suggest some -SHRA out in front over the
associated cold front. Behind this wave, more NW flow increases and
850mb temperatures fall to near -12C. With sfc temps well above
freezing, there`s a chance to see some lake-effect rain showers on
Friday, but otherwise nothing major on the horizon and temperatures
fall mid 30s to 40 on Friday with 40s returning Saturday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 631 PM EDT SAT APR 4 2020
VFR conditions will continue thru the forecast period.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 359 PM EDT SAT APR 4 2020
Winds to 25 knots in the wake of a cold front will diminish from w
to e late this aftn into tonight as high pres approaches from the
west and settles over the area. Expect winds under 15kt across Lake
Superior by late tonight, continuing into Sun as high pres lingers.
Winds should remain light into Mon before easterly winds increase
Mon night into Tue as a low pres trough approaches. Gusts up to 20-
25kt will be possible.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JLB
LONG TERM...JAW
AVIATION...07
MARINE...JLB
Area Forecast Discussion
National Weather Service San Francisco Bay Area
855 PM PDT Sat Apr 4 2020
.SYNOPSIS...Light to locally moderate showers will continue
overnight as a cold front gradually moves south through the region.
Widespread rain is forecast for Sunday as a stronger system drops
down the coast. Locally heavy rain, possible thunderstorms, and
gusty winds can be expected with the Sunday system. Rain will
turn to showers Sunday night into Monday as an upper low moves
south offshore. Showers may linger across the Central Coast
into Tuesday, and possibly Wednesday, as the upper low slowly
exits the region. A warming and drying trend is forecast for the
second half of the week.
&&
.DISCUSSION...As of 8:55 PM PDT Saturday...A weak cold frontal
boundary has been gradually tracking from north to south through
our forecast area today, producing mostly light rain, with
moderate intensity rain showers at times. The frontal boundary was
slow to move through Marin County earlier today and consequently
rain totals were highest there (more than 2 inches on Mount
Tamalpais and 1.20 inches in Kentfield). Several other North Bay
locations picked up between a half inch and an inch of rain today.
South and east of the Golden Gate, rain totals were generally a
half inch or less, except more than an inch near Ben Lomond in the
Santa Cruz Mountains.
Radar shows that the frontal boundary is currently nearly
stationary across the central SF Bay Area, with the most
widespread shower activity over San Mateo, Contra Costa, and
Alameda Counties as well as northern Santa Cruz and northern
Santa Clara Counties. According to the 00Z NAM and latest HRRR,
the frontal boundary will gradually shift south to the Monterey
Bay Area by midnight and then remain there for the remainder of
the night. Meanwhile, satellite shows the stronger upstream system
quickly approaching from the northwest. This second system is
still on track to bring widspread rain to our entire forecast area
on Sunday. A period of heavy rain is likely on Sunday just ahead
of a strong cold front, which will pass through the North Bay
during the morning, through the remainder of the SF Bay Area early
to mid afternoon, and then through the Monterey Bay Area from
late afternoon into early evening. The Storm Prediction Center
places the best chance for thunderstorm development tomorrow
across the Central Valley, but he 00Z NAM forecasts sufficient
instability along the frontal boundary for isolated thunderstorm
development in our area. Therefore, slight thunderstorm chances
were added to Sunday`s forecast in a late afternoon forecast
update.
Additional rainfall through late Sunday is expected to range from
0.50-1.50" in most areas, with locally lower amounts in rain-
shadowed valleys such as the Santa Clara Valley. Up to 2-3
inches of additional rainfall is possible in the coastal ranges.
The latest HRRR focuses the heaviest rain in the Santa Lucia
Mountains above Big Sur, with accumulations of up to 7 inches by
Sunday evening. Most other models forecast less than half that in
the Santa Lucias.
Gusty southerly winds will develop ahead of the incoming front on
Sunday. Strongest winds are expected along the coast where local
gusts up to 40 mph are possible. The latest local WRF model
continues to focus the strongest winds on coastal Monterey County
from Pebble Beach south through Carmel and along the Big Sur
Coast. A Wind Advisory is in effect for coastal Monterey County
from 5 AM to 5 PM Sunday. The WRF model has recently trended
lighter on winds, but will maintain the Wind Advisory for now as
subsequent models may reverse course. Winds are forecast to
diminish quickly behind the cold front by late Sunday.
Rain will change to showers on Sunday night and showers will
continue through Monday as an upper low moves slowly south
offshore. Snow levels are forecast to quickly drop behind the cold
front on Sunday night, down to 3000 feet or even lower in the
North Bay by Monday morning. However, most precipitation will end
by the time the coldest airmass arrives and so snow accumulation
in the hills above 3000 feet should be light.
Both the NAM and GFS are moving the upper low off to our south
more quickly than previous model runs. If this faster movement
verifies, then showers will be confined to only the far southern
portion of our area on Tuesday, with dry weather returning to all
areas by Wednesday. The 12Z ECMWF forecasts a slower southward
movement and thus continued shower potential across our southern
areas through Wednesday. But the overall model trend is for a
quicker return to dry weather next week. The upshot is that the
northern portion of our area will likely start to dry out as
early as Tuesday, with all areas possibly returning to dry
weather by Wednesday, or Thursday at the latest. Dry weather is
then expected to prevail for the remainder of next week and into
next weekend as an upper ridge develops off the West Coast.
Temperatures are expected to be below normal for the first half of
the week, but then climb back to near seasonal averages during
the second half.
&&
.AVIATION...as of 5:20 PM PDT Saturday...The first of two systems
is moving through the Bay Area this afternoon. This will bring
light rain and mostly MVFR cigs through early evening. A short
break from the rain in the Bay Area tonight with cigs rising.
Southerly winds will start to increase rapidly after 09Z ahead of
the second system. Could see gusts as high as 35 kt by Sunday
morning as well as rain and reduced vsbys. Destabilizing
atmosphere will bring a possibility of thunderstorms after 18Z.
Vicinity of KSFO...MVFR cigs will prevail with bases around 1500
ft. Bases could rise to 2500 ft tonight in between systems.
Southerly winds to 15 kt increasing after 09Z with speeds as high
as 20-25 kt gusting to 30-35 kt after 13Z. Winds switch to southwest
and decrease after 19Z. Possibility of thunderstorms and lower
cigs heading into Sunday afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...A weak frontal system will bring a few
showers this evening with areas of MVFR cigs. The front will
stall out and intensify early Sunday morning as the second system
approaches. Rain should pick up after 12-15Z with MVFR cigs
prevailing. Southerly winds increasing to 20-25 kt after 15Z
especially in the Salinas Valley where gusts over 35 kt is
possible. Possibility of thunderstorms after 18Z.
&&
.MARINE...As of 8:30 PM PDT Saturday...A 998 mb low will move
into northern California Sunday morning. Southwesterly winds will
increase overnight ahead of the low. Winds will switch to westerly
Sunday afternoon and decrease Sunday night. There is a slight
chance of thunderstorms on Sunday. A prevailing moderate
northwesterly swell will persist through much of the forecast
period.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tngt...Wind Advisory...Monterey County Coast starting at 5 am
SCA...Pt Arena to Pigeon Pt 10-60 nm from 12 AM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 12 AM
SCA...Pt Arena to Pt Reyes 0-10 nm from 12 AM
SCA...Pt Reyes to Pigeon Pt 0-10 nm from 12 AM
&&
$$
PUBLIC FORECAST: Dykema
AVIATION: W Pi
MARINE: CW
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Area Forecast Discussion
National Weather Service Pocatello ID
213 PM MDT Sat Apr 4 2020
.SHORT TERM...Tonight through Monday night. Satellite imagery
shows low pressure system beginning to work into Oregon and
northern California this afternoon, spreading high clouds across
Idaho. Precipitation on target to spread across the region late
beginning this evening and overnight. Temperatures have warmed
enough to keep snow levels around/above 5000 ft tonight, meaning
rain is expected for lower elevations, especially through the
southern portions of the Snake Plain and southern highland
valleys. Moisture continues to stream into the region Sunday
through Monday. Instability increases slightly each day.
Thunderstorm activity looks to remain in the southeast corner
Sunday afternoon, but the threat widens to most of the region
Monday afternoon. Temperatures gradually increase through the
short term. DMH
.LONG TERM...TUESDAY THROUGH NEXT SATURDAY...
Aside from the chance of a few lingering rain showers Tues
afternoon/eve across the southern and eastern highlands, impactful
weather should come to a close as the main low pressure system
tracks south along the CA coast, and then inland across AZ/NM, too
far south to impact SE Idaho. The GFS/ECMWF/Canadian all continue to
trend toward a common solution of high pressure extending inland
across the northern Rockies Wed/Thurs/Fri, with sunshine and a
warming trend expected. In fact, temps may surge into the 60s by
Thurs/Fri from the Snake Plain south and west, with 50s elsewhere,
offering a nice taste of spring! The abnormally wet NBM solution
overnight has trended drier toward the deterministic model
consensus, so we made very few changes/edits. Overall forecast
confidence is moderate to high through Fri. Confidence breaks down a
bit by next Sat with the potential for a quick system to move
through over the weekend, but little model agreement exists in the
details with the GFS advertising a more pronounced trough/closed
low, the EC a moist NW flow, and the Canadian somewhere in between
the two with some timing differences as well. The warm temps could
help support a few thunderstorms with this feature. - KSmith
&&
.AVIATION...
Quiet aviation conditions continue this afternoon, with unlimited
cigs/vsbys and just some thin, high-level cirrus clouds streaming
through. We still expect cigs to thicken and lower this eve into
tonight as our next system approaches, but based on the latest
guidance we were less aggressive in this trend in the 18z TAF
package, with BKN cigs generally expected to hold off until after 03-
07z depending on the terminal. The same trend is noted for precip
chances...we do expect a period of rain/snow shower activity to
transverse the area overnight, but after reviewing the 12z HREF
guidance as well as the RAP and NAM time-heights, confidence in
showers directly impacting KPIH/KBYI/KIDA were too low to maintain
predominant wx attributes, and we backed off to VCSH as well as
refined expected timing. Could see some borderline MVFR cigs Sun
morning. For KSUN/KDIJ, maintained the idea of some more organized
snow with possible attendant vsby reductions, and refined timing
here as well. Some thunderstorms will be possible Sun afternoon,
perhaps affecting the Snake Plain terminals and smaller airports to
the south. We`ll evaluate need for VCTS in future TAFs. - KSmith
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
None.
&&
$$
...Update to aviation forecast discussion...
.SHORT TERM...(This evening through Sunday)
Issued at 335 PM CDT Sat Apr 4 2020
As of 20Z Saturday afternoon, broad southwesterly midlevel flow was
present across the central and southern Plains. A broad surface
ridge extended across the entire Plains. Low level stratus has
scattered from northwest to southeast across the forecast area with
only extreme east-central KS remaining cloudy. RAP and HRRR forecast
soundings suggest mixing heights should near 825-850mb by late
afternoon, yielding surface temperatures near 50. Transitioning into
tonight, the primary concern is how far the stratus will retreat
northward. As the aforementioned surface ridge slides eastward,
southeasterly flow will return to the area, allowing the stratus
deck across southeast KS/western MO to lift northward. Latest model
solutions are in modest agreement with the stratus reaching the
turnpike region after 06Z. This should allow for areas along and
southeast of the KS Turnpike to remain above freezing. As a result,
will not be issuing any frost/freeze products at this time.
Elsewhere, lows should hover near freezing, but based on partner
input, vegetation across this area is less susceptible to a
frost/freeze. The surface ridge will push east through the day
Sunday allowing WAA to return to the forecast with highs reaching
the low 60s.
.LONG TERM...(Sunday night through Saturday)
Issued at 335 PM CDT Sat Apr 4 2020
Transitioning into the extended period, a western trough will dig
into the southwest US Sunday night into Monday, yielding a deepening
lee trough across the High Plains. WAA will further increase Sunday
night as a 35-45 kt LLJ overspreads the region. There may be
sufficient moistening and isentropic ascent for a few showers early
Monday morning. The warming trend will continue into Monday with
afternoon highs reaching the 70s. By Tuesday the aforementioned lee
trough will traverse the area by late afternoon and evening. Model
solutions prog 850 temps to reach 20 C, which translates to
afternoon highs in the 80s. This looks to be a dry frontal passage
with limited available moisture.
A northern stream trough will shunt a secondary surface cold front
through the area Wednesday evening. This will cool temperatures into
the 40s by Wednesday night. Otherwise northwesterly midlevel flow
looks to dominate the remainder of the week with cooler temperatures
in-store. Afternoon highs are progged to remain in the 50s and 60s
with lows in the 30s.
&&
.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 639 PM CDT Sat Apr 4 2020
VFR to begin at KTOP/KMHK/KFOE with some decent uncertainty on
how observed MVFR stratus in southeast Kansas will impact
terminals overnight. Similar to yesterday, models are not handling
the current observational trends so have opted to side closest to
the RAP that lifts the VFR stratus northward between 00Z and 01Z
at KTOP/KFOE. There is indication that light winds will help
stratus lower to MVFR overnight thru at least 16Z before
dissipating.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Baerg
LONG TERM...Baerg
AVIATION...22