Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/15/22
Area Forecast Discussion
National Weather Service Binghamton NY
930 PM EDT Thu Apr 14 2022
A cold front will push into New England this evening, taking
scattered showers and thunderstorms with it. High pressure will
build in overnight, with drier weather on Friday, but gusty
winds are also expected. Another cold front will bring
additional showers and cooler temperatures this weekend.
.NEAR TERM /THROUGH FRIDAY/...
915 PM Update...
This update involved quite a few minor adjustments for a little
bit of everything. There are some lingering showers moving
through the Poconos and Catskills, so a slight chance remains
for mainly those areas until the top of the hour. Otherwise,
skies continue to clear behind these lingering showers. Fog has
developed at Rome where it is one of just a few locations where
the obs indicated the dew point depression is in the single
digits. So patchy fog was added in Oneida County for the next
couple of hours. Then dew points up there should drop and
conditions will then be too dry for fog to remain.
As mentioned in the last update, the dew points were a struggle.
The NBM was lower than what was previously forecasted and model
guidance was indicating lower dew points overnight as well. For
this update, the NBM, Conshort, and HRRR was used for the
hourly dew points through the overnight hours. This blend better
matched recent observations. The forecasted hourly temperatures
were actually doing fairly well, so only minor adjustments were
600 PM Update...
The thunderstorms are out of our region and there is no longer a
severe threat. However, there are some scattered showers passing
through. Because of a trailing line of light showers/drizzle,
PoPs were expanded westward slightly. Though with how dry areas
have become after the frontal passage, anything from the
trailing line may struggle to reach the ground. Showers should
be completely out of the region within the next few hours.
Since we are not seeing any lightning with anything that is over
the region, chances for thunderstorms were removed.
Skies are clearing behind the showers. This will allow some to
have a view of the sunset this evening. The hourly sky forecast
was updated based on satellite and updated guidance. Blending in
some of the NAM Nest and NBM with the previous forecast does
speed up the clearing this evening. By midnight, the region is
expected to be under mostly clear skies. The hourly winds were
touched up over the next few hours. Conditions will remain gusty
until an inversion develops close to the surface, cutting off
any mixing from above. As mentioned, behind the clouds and rain
showers, conditions are becoming quite dry with dew points
quickly dropping. This may need to be the focus for the update.
338 PM Update...
Showers that developed ahead of the front appear to have limited
instability over most of the CWA, though there`s still a narrow
window where a stronger thunderstorm could affect Pike or
Sullivan County before 5 PM. Otherwise, expect the front will
pass though most areas with some brief gusts of 30 to 40 mph,
and scattered post-frontal showers will linger a couple hours
behind the frontal passage. Most areas west of I-81 will see
some sunshine before sunset.
High pressure will build across the Carolinas overnight, with a
sharp ridge axis extending north into the Mid-Atlantic states.
Meanwhile, a slow moving upper low will remain over northwestern
Ontario. We`ll see a return to west-southwest winds on Friday,
with temperatures recovering back into the lower to middle-60s,
warmest over the Finger Lakes region. Deep mixing will allow for
some gusty winds again, peaking around 35 to 40 mph in places
during the afternoon.
Another disturbance associated with the big upper low will move
into the Lower Great Lakes later Friday, with a few showers
possible in the afternoon north of the Thruway. A stalled out
cold front will slowly sag southward through Friday night, with
rain showers expanding south as the front drifts south. Precip
should stay north of the Twin Tiers through Midnight Friday
Night (Sat AM), but will work into PA before dawn.
145 PM Update...
Cold front currently extends from just east of Rome to near
Marathon and Towanda, and is quickly pushing to the east. Wind
gusts of 35 to 45 mph have been occurring with the frontal
passage. RAP analysis shows SBCAPE vales of around 500 J/Kg just
ahead of the front, but this is likely erroneous with the model
not accounting for the spotty showers and slightly cooler
temperatures that have cropped up out ahead of the front. As
time goes on, it`s looking more like the thunderstorm chances
will be limited to the far eastern 2-4 counties of the CWA,
with gusty showers elsewhere.
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
245 pm Update...
Another upper level trough moves through our area this period.
A slow moving northeast to southwest cold front moves southeast
Saturday with up to half an inch of rain. The front will be a
sharp boundary for 2 air masses. Highs Saturday from the upper
40s north to low 60s far south. Temperatures fall in the
afternoon. It is cold enough for precipitation to change to
snow Saturday night. By that time showers will be light with a
short wave and weak front moving through. Higher terrain could
get a dusting of snow. Some lake enhancement with 850 mb
temperatures dropping to -8C. Mixed showers continue into
Sunday before ending late in the day as the trough moves
through New England. Low temperatures in the upper 20s and
lower 30s. Sunday will be the coldest of the next week with
high temperatures in the 40s.
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
245 PM update...
Little change. A cool unsettled pattern with an upper level
trough on Tuesday and another on Thursday. Briefs breaks of dry
weather. Discussion below covers the complexities of next week`s
330 AM Update...
The long term is looking cooler than average and fairly active.
Weak ridging builds in Sunday night into Monday with a break in
precipitation as well as some moderating temperatures. Monday
night into Tuesday is looking a little more interesting.
Ensemble mean flow at 250 mb shows a trough over the Great Lakes
with a strong jet max advecting in. This supports the chance of
a stronger surface low during the Monday night into Tuesday
timeframe. WPC clusters show good agreement on low 500 mb
anomalies associated with a deeper trough over the Great Lakes
region. The location of the surface low is uncertain with two
low pressure systems forming, one inland and one a coastal low.
If the inland low becomes the dominant low then rain will be
likely area wide. The coastal solution could pull enough cold
air into the region as it deepens to give higher elevations a
shot at some accumulating snow. Even if this solution occurs,
there is differences in the timing of the snowfall. In order to
get accumulations of more than an inch or 2 the snow would need
to fall at night and at a fairly good pace to overcome the
melting from the warm soil temperatures. There is higher
confidence in mid week as the low moves into the Canadian
maritimes and deepens with NW flow. Another system could move
in mid to late next week though the complexity of the pattern
only a slight chance of precip was added Wednesday into
.AVIATION /01Z FRIDAY THROUGH TUESDAY/...
High pressure building in from the west along with a very dry
air mass will keep weather conditions quiet through the next 24
hours. Skies will be mostly clear tonight before high clouds
approach from the west late Friday morning and then thicken in
the afternoon as a weak front slowly slides in from the west.
Winds will remain light less than 7 kt tonight out of the
southwest and then increase after 13Z Friday with gusts 15 to 20
kt. Should see a period between 16-23Z where gusts 20 to 30 kt
are possible. Winds subside and shift to the northwest across
the northern terminals before 00Z Saturday.
Friday Night through Saturday Night...Showers possible with
Sunday...Mostly VFR, though some lake effect rain and snow
showers with associated restrictions possible over Central NY.
Monday Night through Tuesday...Showers possible with
associated restrictions return.
Despite scattered showers today, high pressure building in
overnight bring in much lower dewpoints to the area. Southwest
winds will redevelop tomorrow as the surface ridge axis shifts
east of the area, and with a fairly tight pressure gradient, a
few gusts could top 35 to 40 mph, especially in favored
downslope locations. Temperatures will warm back up to the 60s
in most areas, with middle-60s in downslope areas around the
Finger Lakes. With the drier airmass, very fine fuels will dry
out rather quickly despite the rain. Minimum RH values in the
afternoon range from 28 to 35 percent in the Mohawk Valley, and
around 25 percent across the Finger Lakes, Twin Tiers, and most
of northeast PA. This will result in enhanced fire weather
conditions. No red flag warnings are in effect at this time, but
will be reassessed based on fuel conditions.
Area Forecast Discussion
National Weather Service Peachtree City GA
807 PM EDT Thu Apr 14 2022
Chances for showers, and especially thunderstorms, is looking
increasingly unlikely in east-central Georgia, so PoPs have been
lowered and thunder has been pulled from the forecast entirely for
the remainder of the day. Otherwise, the short term forecast
remains mostly on track this evening.
Updated for the 00Z Aviation Discussion.
.PREV DISCUSSION... /Issued 347 PM EDT Thu Apr 14 2022/
SHORT TERM /Rest of today through Friday Night/...
Chances for any regeneration of convective triggering in the south
and east look to be lowering as persistent cloud coverage/solar
sheltering appears to have limited destabilization needed for any
storms. CAM solutions overall have little to no development as
well this afternoon into evening but will hold onto some pops as
we cannot rule out some isolated showers or thunderstorms though
general to weak intensity. SPC has also removed the Day 1 Marginal
out of the area and the RAP progged SBCAPE looks quite meager in
the next several hours.
Otherwise the focus shifts to how low some dewpts and resultant RH
values get Friday afternoon into evening and any fire danger
concerns. Went with a NBM/MAV/MET blend which looked like a decent
compromise to go a bit lower than just the NBM but not too low,
given how we should switch over to an east/SE fetch and the Nam
thermal profile looks dry near the top of the boundary layer but
not as dry as seen in previous dry dewpt "bust" days where we get
much lower than forecast. For now it looks borderline in parts of
the north so will let evening or overnight updates assess with
possible new or consistent guidance.
Friday night/Saturday morning looks to have an upper disturbance
and phased enhanced moisture field traversing the near zonal flow
aloft approaching from the TN Valley. This should bring the next
increased chance of precip. There is question as to how much or if
any CAPE is accompanying this feature but for now have slight
Temps tonight a bit below climo norms given post frontal regime
and lessening cloud cover/moisture. Generally looking at 40s in
the north and 50s south. We should warm up to above normal Friday
afternoon with many areas in the mid 70s to low 80s, then above
normal lows Friday night given aforementioned zonal flow and
increased moisture/precip chances.
LONG TERM /Saturday through Thursday/...
With mostly zonal flow in the mid-levels and the remnants of the
front starting a slow crawl northward, the passage of a few
shortwave disturbances aloft will lead to a summerlike pattern with
chances for rain daily through the weekend. Even with the passage of
several days on the long term desk and numerous model runs, there
remains a great deal of uncertainty in potential for lingering
weekend thunderstorms. Coverage of instability will depend greatly
on where the frontal boundary drifts to, and there is much
disagreement among global models. The Euro continues to take the
more bullish route, keeping an unstable airmass in place (500-1000
J/kg of SBCAPE) across much of the area south of I-20 through Sunday
and even into Monday, while the GFS keeps regions of instability
rather sparse north of the Georgia/Florida border after sundown and
lower in magnitude as a whole. It seems likely that portions of the
CWA will hear a rumble of thunder or have the potential for the
isolated strong storm form through the start of the week, so have
opted to carry a slight chance to chance of thunderstorms through
To start off the work week, a stout upper trough across the northern
Plains and associated broad frontal boundary dig to the south and
east. Models prog. a leading shortwave disturbance to drift across
the Florida panhandle around the same time the front enters the
southeastern CONUS, resulting in a broad shield of precipitation
ahead of the frontal convection. As has been the theme for the long
term, there is significant divergence in terms of atmospheric
moisture between global models. The secondary lobe of low pressure
the develops in the Euro solution suggests the potential for
isolated severe concerns and higher QPF, whereas the GFS solution
has patchier/lower coverage and lacks the reinforcing low at the
surface. Will need to keep an eye on this going forward, especially
after taking into consideration weekend precip totals for antecedent
conditions for flooding concerns. Have kept chance to low-end likely
PoPs for Monday to account for dissenting model opinions. Beyond
that, ridging begins to build in once again aloft and at the
surface to dry things back out through the end of the extended.
VFR conditions are expected through the period, as ceilings have
moved south and east away from all TAF sites. Lower ceilings and
precipitation chances are expected to return just beyond the TAF
period. Winds will start the evening at NW at 7-12 kts,
diminishing to 3-5 kts and shifting to NE by 09Z early Friday
morning. Winds will increase to 10-12 kts by mid-morning, with
gusts up to 22 kts during the afternoon hours. Meanwhile, winds
will shift to E by 13Z and SE by 17-18Z.
//ATL Confidence...00Z Update...
High confidence on all elements.
.PRELIMINARY POINT TEMPS/POPS...
Athens 48 76 54 74 / 0 0 30 50
Atlanta 49 76 58 74 / 0 0 40 50
Blairsville 41 70 49 69 / 0 0 60 40
Cartersville 43 77 56 74 / 0 0 50 40
Columbus 50 81 60 79 / 0 0 30 50
Gainesville 48 73 54 72 / 0 0 50 40
Macon 50 80 57 80 / 5 0 20 50
Rome 45 78 56 75 / 0 0 60 50
Peachtree City 47 78 57 76 / 0 0 40 50
Vidalia 57 79 59 82 / 20 5 10 50
Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
953 PM CDT Thu Apr 14 2022
Issued at 950 PM CDT Thu Apr 14 2022
After a VERY windy day, winds have eased considerably since sunset
with speeds across the area much nicer in the 10 to 15 mph range.
A narrow axis of mid-level clouds is beginning to shift east into
areas south of I-80. Thanks to very dry air at the surface this is
currently only in the form of virga. This will likely serve as
the focus for our precipitation potential early Friday morning
into the daytime hours.
Confidence in precipitation trends over the next 24 hours remains
on the lower side, however, with a fair amount of variability in
when we saturate enough for precipitation to reach the surface as
well as how quickly the precipitation eventually exits the area.
Did make some minor edits to the precip forecast for late tonight
through tomorrow morning to nudge up chances along and between
the I-80/88 corridors. Model soundings would support snow mixing
in within any band of rain where rates are high enough for
sufficient wet-bulb cooling for snowflakes to reach the ground. So
I wouldn`t be surprised of a narrow axis (favoring areas mainly
north of I-80 and west of the metro) that could see minor slushy
accumulations if we can get a persistent band of precipitation to
The RAP and HRRR have precipitation expand in coverage along and
southeast of I-55 Friday late afternoon into the evening. For now
have made no changes to that period given a fair amount of model
guidance still moving the precip out of the area more quickly.
Issued at 222 PM CDT Thu Apr 14 2022
Forecast concerns include high winds through sunset this evening
and then a chance for mixed rain/snow or a period of snow early
Wind gusts continue to slowly increase early this afternoon with
many locations gusting into the mid/upper 40kt range. So far UGN
has seen the highest gust, to 55kt. These high winds will continue
through sunset and then quickly diminish through the early/mid
evening hours. There will likely still be some gusts overnight but
its possible gusts will diminish for much of the area overnight.
Gusts will increase again on Friday, possibly back into the 30 mph
There remains quite a bit of uncertainty for precipitation chances
late tonight into Friday. The global guidance is more aggressive
with a band of light rain either mixed with light snow or possibly
turning to light snow across the center part of the cwa overnight.
The high res guidance does not develop much of anything, perhaps
some sprinkles/flurries. Its difficult to move away from chance
pops and made no significant changes to this time period, along
with no changes to light qpf. If this precip materializes, that
likely means that its intensity will be heavy enough to cool the
column sufficiently to produce a period of light snow. And if
that happened, some minor snow accumulation on grassy surfaces is
possible. But overall confidence is low. Midday then looks mainly
dry with additional light rain chances in the afternoon and mainly
along and south of I-80 as a cold front begins to move across the
Issued at 246 PM CDT Thu Apr 14 2022
Friday night through Thursday...
Relatively quieter weather Friday night into next week, with only a
couple of chances of precipitation as weak waves/fronts move through
our area. Temperatures will be below normal through the weekend and
into next week, with a warming trend expected around the middle of
In the wake of Friday`s cold front, colder air will filter in Friday
overnight, leading to lows in the mid to lower 30s, with locations
further away from Michigan falling to, or even below freezing
Saturday morning. High pressure will ridge in from the west, keeping
our winds out of the northwest and dropping the 925 mb temperatures
to near -5 degrees C. Even with mostly clear skies, high
temperatures will remain below the norm of around 60 F for mid
April, climbing only into the mid to upper 40s. Little will change
Saturday overnight, with continued mostly clear skies allowing our
lows to drop even colder, with most locations falling down to or
below freezing again Sunday morning, while highs will again be in
the mid to upper 40s Sunday. Our first wave/front is forecast to
arrive sometime Sunday afternoon to overnight, with cloud cover
increasing with this system. Models are not in agreement as to the
exact timing of this system, but a chance for some precipitation to
occur Sunday night exists. With temperatures still on the cold side,
some of this precipitation may fall in the form of rain/snow mix,
especially Monday morning during our coolest temperatures. Presently
no accumulation is expected as cloud cover should keep surface
temperatures above freezing Monday morning.
With this reinforcing shot of cold air, highs on Monday are expected
to remain below the seasonal normals, reaching into the upper 40s to
near 50. Winds will be gusty from the northwest Monday afternoon.
Temperatures will remain cool on Tuesday, with lows again near to
below freezing and highs around 50. The next weather system is
expected on Wednesday, with winds becoming southerly ahead of this
system, allowing temperatures to warm up a bit, with lows Wednesday
morning expected to stay above freezing, while highs will climb into
the mid to upper 50s. Similar to the Sunday system, models are not
in great agreement on timing and location of the front, but there
will be a chance for some precipitation Wednesday. And although we
warm up a bit, temperatures will still be cool enough to once again
possibly have some snow mixed in with the rain, but again no
accumulations are expected. The cooler air with the Wednesday system
does not stay in place for long, with temperatures expected to be
more seasonal on Thursday.
For the 00Z TAFs...
Forecast points of interest for ORD and MDW through Friday are:
* Gusty west-southwest winds easing fairly quickly between sunset
* Likelihood of light rain within the pre-dawn through morning
period during Friday, with the chance for some snow to mix in or
even briefly go to all snow between 11Z and 15Z
West-southwest winds have begun to abate and that rate of
diminishing should increase after sunset with the loss of mixing.
Prior to sundown at 0030Z, sporadic gusts to or exceeding 40 kts
will be seen across the area.
An upper level weather disturbance will scoot across the area
during the pre-dawn hours on Friday into the morning. While the
atmosphere is dry ahead of this, the forcing for ascent will
result in deepening saturation. Trends in guidance indicate that
this should be enough for periodic light precipitation within
that time. The envelope of model solutions tend to support the
Chicago area airports being in this light precipitation axis,
with Rockford potentially just beyond the northern periphery.
With this precipitation occurring at the coolest time of day and
the atmosphere fairly cool to begin with, some snow could mix in
as temperatures fall to their web bulb values. Cannot rule out
the precipitation just going to only snow for a 1-3 hour period,
and that would overlap the morning rush. At present though, this
is still more of an outlier solution. If that were to happen, it
would be unlikely snow would stick on most paved surfaces.
For the remainder of Friday after the light rain ends by 16Z-17Z,
southwest winds will be breezy but far less than today.
LM...Small Craft Advisory...nearshore waters until 5 PM Friday.
Visit us at weather.gov/chicago
Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Springfield MO
600 PM CDT Thu Apr 14 2022
1. Elevated fire conditions continue this afternoon with gusty
winds and a dry airmass.
2. Rain chances about every other day (Friday/Sunday/Tuesday
Night into Wednesday).
3. Below normal temperatures likely through early next week.
4. Warming trend by the middle of next week.
.SHORT TERM...(This evening through Friday Night)
Issued at 251 PM CDT Thu Apr 14 2022
Gusty southwest winds and relative humidity values in the 25-35%
range will allow for areas of locally elevated fire weather
conditions to continue this afternoon into early evening,
primarily in locations that have not seen much rainfall in the
last couple of weeks. As a ridge of surface high pressure slides
south and eastward of the Missouri Ozarks, winds will shift back
out of the south later this evening. Sounding profiles show mid-
level saturation and cloud cover increasing overnight keeping
overnight lows in the mid to upper 40s. A few locations in the
eastern Ozarks could drop into the low 40s tonight.
Afternoon temperatures Friday look to rise into the low 60s across
Central MO and the upper 60s to low 70s over southwestern MO and
the MO/AR border. A few shortwave impulses look to traverse
through the overall zonal flow aloft Friday. With moisture
increasing throughout the day Friday, there should be enough
synoptic-scale ascent for some scattered shower activity and
isolated thunderstorms through the day tomorrow. A boundary looks
to push into the southern portions of the CWA Friday evening into
Friday night. On the warm side of that boundary, an axis of
moderate instability looks to sprawl across eastern Oklahoma and
the Ozarks region. The greatest instability looks to reside along
and just south of the MO/AR border where the HRRR and RAP both
hint at an environment with 1000-1500 J/kg of MLCAPE. 12Z high-
resolution guidance continues to pick up on a few isolated
stronger storms, possibly severe due to sufficient deep layer
shear, around the MO/AR border late Friday evening into early
Friday night. Storms may take on a more elevated nature due to
some capping below 850mb. However, with steep 700-500mb lapse
rates and strong 0-6km shear, isolated large hail and damaging
wind gusts will be a possibility.
.LONG TERM...(Saturday through Thursday)
Issued at 251 PM CDT Thu Apr 14 2022
Northerly winds will be present Saturday as high pressure filters
in from the north behind that frontal boundary that pushes through
the area Friday night. A quick moving upper-level ridge will also
pass over the area Saturday with afternoon temperatures only
rising into the upper 50s and mid 60s with those breezy northerly
Another round of rain chances is expected on Sunday as models
agree upon a shortwave trough pushing into the region leading to a
cool and rainy Easter Sunday. The SGF CWA will most likely still
be north of that boundary, therefore very little instability will
allow for mostly rain showers on Sunday with some possible
embedded thunder. There is quite a bit of spread in the NBM
guidance for high temperatures on Sunday, likely to due with
uncertainties in the coverage of showers during the day. 25th
%tile lies near 50 degrees while the 75th %tile sits near 60
degrees in the Springfield area for Sunday afternoon. The middle
of the road 50th %tile brings the Springfield metro into the mid
50s on Sunday. As high pressure builds in and that system moves
out Sunday night, skies may clear some and frost potential may
arise Sunday night into Monday morning.
Monday and Tuesday both look cool and dry with afternoon
temperatures rising into the mid 50s and mid 60s both days. Frost
potential may return again Monday night into Tuesday morning. WPC
Cluster Analysis shows decent agreement between ensemble members
of another shortwave trough pushing into the area late Tuesday
night into Wednesday bringing widespread rain chances to
southeastern Kansas and the Missouri Ozarks during that time
A gradual warming trend under a broad ridging pattern looks more
likely the second half of next work week. The CPC highlights
this warming trend well with above average temperatures currently in
the 8-14 Day Outlook. GEFS and ECMWF ensembles anomalies also
support this warming trend the second half of next week.
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 557 PM CDT Thu Apr 14 2022
Low level wind shear is expected late tonight into Friday morning
as a low level jet develops over the area. Shear of 40 to 50 kts
will be possible. Gusty winds will develop on Friday by mid
morning. Eventually a front will begin to push south through the
area with scattered showers developing by late in the afternoon
and continuing into the evening. Expecting VFR conditions through
much of the period, with a chance of some MVFR within any showers
Area Forecast Discussion
National Weather Service Sacramento CA
325 PM PDT Thu Apr 14 2022
Cool weather continues with unsettled weather bringing periods of
rain and mountain snow into the weekend. Warmer with dry weather
expected Sunday. An unsettled weather pattern returns next week
with the potential for more rain and mountain snow.
We are going to remain in an active and unsettle weather pattern
the next few days with periods of rain and mountain snow. A short
wave trough pushing into far southern OR is showing up nicely on
water vapor. This trough is pushing a cold front into NorCal
stretching from the Lassen Park area southwest through the Ukiah
area. We are seeing light Valley showers ahead of this front with
widespread rain and snow over the higher elevations. PWATs ahead
of the front are 0.50 to 0.90" and we are seeing hourly rain rates
generally 0.10 to 0.35" over the higher elevations and less than
0.05" in the lower elevations. Expect these rain rates to continue
for the next few hours but things will start to let up quickly
after 8 pm this evening. Snow levels are generally around
5000-5500 feet and we should see them come up about 500 feet this
evening. Mountain snow will continue to bring mountains travel
issues into the evening.
The HREF and other CAM models such as the HRRR are building in
instability over the northern Sacramento Valley and Shasta
County. Currently Meso-analysis is starting to show 100 mb of
MUCAPE over this region and CAPE has been slow to build in due to
cloud cover and this should limit the thunderstorm threat but
there is about a 15% chance or so to see a few thunderstorms. CAPE
in the area looks to linger into the later evening but we should
see the thunderstorm threat end by midnight. Soundings do show
some low level veering but 0-1 km shear is pretty low and that
should limit any funnel potential with small hail and gusty winds
the main threat with any thunderstorms. PWATs even behind the
front are quiet high, ~0.50" but somewhat fast storm motion
should limit heavy rain but brief downpours can be expected.
Things will dry out overnight and we will see a mainly dry start
to Friday. The dry conditions will be short lived though as
another short wave trough digs over the Pacific and moves over
NorCal Friday night into Saturday. This will be a quick moving
system but is able to pick up decent amount of moisture again
with PWATs 0.50-0.90". With the further south track of this trough
we will see higher snow levels in the 5500-6000 foot range over
the Sierra and 4500-5500 feet over the Coastal Range and Shasta
County Mountains. With the trough axis moving just to our south
the highest QPF can be expected from about I-80 north. QPF totals
are looking to be 0.90-2.25" over the mountains with locally
higher amounts over the Lassen Park area. Valley totals 0.15-0.75"
and 0.75-1-75" in the foothills. Snow totals are looking to be
6-12" above 5500 feet with locally higher amounts over Lessen
We do see some CAPE build in Saturday afternoon mainly over the
northern Sierra Foothills and the Sierra north of I-80. Forcing
will be rather weak by the afternoon and the thunderstorm threat
is looking low but not zero. An isolated cell or two will be
possible. The environment on Saturday will be very similar to
today and similar threats can be expected with any thunderstorms
that end up developing.
Our active and unsettle weather will take a break on Easter
Sunday as weak ridging builds in and we will see temperatures
warm to near average.
.EXTENDED DISCUSSION (Monday THROUGH Thursday)...
Unsettle weather is going to return for the extended forecast as
we will see a few troughs push over the region. The first one will
dig out of the Gulf of Alaska later Monday into Tuesday. There is
some spread in the ensembles mainly with how deep the trough digs
but also some with timing. The northern mountains will see the
best chances for showers. Wednesday should start out dry but
another trough will bring rain and snow chances but uncertainty is
quite high with this trough in the ensembles. Highs will
generally be near seasonal averages.
Widespread MVFR with local IFR/LIFR conditions over Norcal thru
06z tonight as Pacific storm system moves inland. Chance of
thunderstorms over the northern Sacramento Valley continues
through 04z, along with gusty southerly winds to 30 kts through
00Z. Sierra terrain obscured AOA 4000 feet.
Winter Weather Advisory until 11 PM PDT this evening for West
Slope Northern Sierra Nevada-Western Plumas County/Lassen Park.