Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 02/04/23
Area Forecast Discussion
National Weather Service Boise ID
846 PM MST Fri Feb 3 2023
.DISCUSSION...As expected today`s Pacific trough weakened as it
reached our CWA, and the gusty winds this afternoon diminished
this evening, except in Jerome and Gooding where northeast winds
have continued 15 to 20 mph. Weak ridging will keep our area dry
and relatively mild Saturday before a stronger Pacific trough
comes in Sunday with a better chance of rain and snow. Models are
inconsistent about shadowing in the Treasure Valley by the Owyhee
Mountains but the consensus favors the wetter models and high
PoPs, as in our current forecast. Should be rain below 4000 feet
MSL in the southern valleys and snow above, and snow in northern
areas. No updates for now.
&&
.AVIATION...Mostly VFR, except for isolated snow showers mostly east
of KMYL briefly obscuring terrain in IFR conditions. Surface winds:
variable less than 10 kt, except E 10-15 kts at KJER through
04/05Z. Winds aloft at 10k feet MSL: W-SW 20-30 kt.
Sunday Outlook...A strong system will move through Sunday with snow
levels 3000-4000 feet MSL. Mountains will see widespread IFR in
snow creating terrain obscuration. Valleys will see MVFR with
rain/snow showers. Breezy SW to SE winds will develop Sunday and
become W to NW Sunday night.
&&
.PREV DISCUSSION...
SHORT TERM...Tonight through Sunday night...A system will weaken
considerably as it moves across the Pacific NW today. The system
will bring light snow showers to the mountains this afternoon and
evening, with generally less than an inch expected. The system
will also bring windy conditions, especially across southeast OR
and southern ID near the NV border and Magic Valley through
tonight. A weak ridge will transition over the area on Saturday
with dry conditions. Forecast temperatures may be too cool in the
Snake Basin, as the model guidance continues to initialize with
too much snow cover over much of the Plain. HRRR guidance has
temperatures reaching the upper 40s to low 50s tomorrow across the
Upper Treasure and Magic Valley. A stronger trough will move into
the area on Saturday night into Sunday morning, with moderate
snow accumulations possible over the mountains and light
accumulations over the valleys. Still some uncertainty in
evolution of the system on Saturday and Sunday and where the
center of the low pressure tracks. If the center of the low tracks
over the region, expect light snow accumulations to the lowest
valley floors, but right now, think it will mainly be rain below
4000 feet. Snow accumulations of 3 to 6 inches across the mountains
are possible with this system with local amounts up to 10 inches
across the higher peaks.
LONG TERM...Monday through Friday...Lingering showers will remain
in the region through Monday morning as an upper level trough exits
to the east. A building ridge will dominate the weather through
Tuesday night, bringing dry and near normal temperatures. Then,
model tracks exhibit moderate uncertainty with the track of a
midweek upper level trough. The ECMWF ensembles favor a wetter and
deeper trough moving through the region early Wednesday, with other
ensembles favoring a drier and more northerly track for the trough.
Model agreement remains on Central ID Mountain precipitation and a
slight decrease in Wednesday-Thursday temperatures. The current
forecast favors a weaker and drier trough moving through the region,
with light accumulations of a valley rain-snow mix and mountain
snow. The return of an upper level ridge over the West Coast will
increase temperatures for Friday, and keep the region dry and
mostly clear.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.
&&
$$
www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise
DISCUSSION...LC
AVIATION.....SP
PREV SHORT TERM...KA
PREV LONG TERM....SA
AREA FORECAST DISCUSSION
National Weather Service Hastings NE
546 PM CST Fri Feb 3 2023
...Aviation Update...
.DISCUSSION...(This evening through Friday)
Issued at 203 PM CST Fri Feb 3 2023
Key Messages:
*Warming trend through the weekend and into Monday
*Temps will remain above average (generally in the 40s) next week
*Next chance for precip is iffy at best and would be Tues night
through Thursday morning
Satellite showing that very similar to yesterday cloud cover
scattered out earlier than expected this morning and has left us
clear for most of the day. Though highs have still struggled to
reach the 20s most places, and were expected to reach the 30s today
but that may not happen. Ridging aloft is just to our west today
along with a sfc high off to our east.
The warming trend is expected to continue this weekend and into
Monday as well. Flow aloft becomes more zonal tomorrow as a dry
shortwave moves through and brings a front through that will have
some breezy winds. Overall Sunday looks to be the nicest day with
highs mainly in the 40s and lighter winds with brief ridging aloft.
Monday brings a more active pattern with a split wave moving
through. There is still quite a bit of model uncertainty with these
waves though, especially on timing but also on trof placement. That
being said, the going forecast currently brings PoPs up from the
south Tuesday night and lingers them through Thursday morning. These
are not very strong PoPs however and only top out at about 30%.
Temperatures will remain above average through next week with highs
generally in the 40s and lows generally in the 20s (with a few
30s).
&&
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Sunday)
Issued at 543 PM CST Fri Feb 3 2023
High confidence VFR conditions expected with southwesterly winds
shifting and becoming northwesterly late in the period.
Upper level cloud cover can be seen on satellite encroaching on
the local area from the west. Expect this high thin cirrus to
thicken through the period, but remain solidly near the 25KFT
level. Some hints in HRRR of fog formation overnight tonight, but
confidence in this is extremely low as surface flow should be out
of the southwest and cloud cover aloft should keep temperatures up
a few degrees and above dewpoints, preventing much - if any fog
formation. Winds remain gusty at KGRI this hour, but should drop
off shortly, with steady southwesterly winds overnight eventually
shifting during the daytime hours tomorrow becoming more westerly
and eventually northwesterly as a weak frontal boundary crosses
the local area.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
DISCUSSION...Shawkey
AVIATION...Rossi
Area Forecast Discussion
National Weather Service Phoenix AZ
425 PM MST Fri Feb 3 2023
.UPDATE...Updated 00Z Aviation Discussion.
&&
.SYNOPSIS...
High pressure building over the intermountain west will yield
above normal temperatures through the weekend. A weak system on
Monday will bring slightly below normal temperatures to start the
week along with some breezy conditions. After this storm moves through
the region, near normal temperatures will likely prevail through
the end of the week.
&&
.DISCUSSION...
Latest water vapor imagery and RAP streamline analysis indicate
that across the intermountain West a weak trough has supplanted
the ridge, which has migrated eastward into the southern Plains.
This is resulting in widespread high clouds across the Desert
Southwest, though conditions remain relatively warm and dry below
500 mb. Despite the clouds, forecast high of 74 degrees in Phoenix
still appears attainable.
Latest models continue to indicate another high amplitude short-
wave ridge will move through the western CONUS Saturday, resulting
in a continued warming trend. NBM high temperature for Phoenix
remains at 76 degrees, which would tie for the warmest so far this
year. Although this is only a handful of degrees above normal,
sensitive groups and those not acclimated to the lower-latitude
sunshine and warm conditions are urged to take precautions.
Somewhat cooler conditions are expected Sunday as a Pacific low
pressure system moves into the Great Basin. Biggest sensible
impact across the forecast area from this system will be an
increase in wind, particularly across southeastern California.
However, latest ECMWF EFIs only top out at 0.7, suggesting a
possible Wind Advisory for the wind prone areas of southwestern
Imperial County. The threat of windy conditions will spread
eastward Monday as the trough moves into the southern Rockies. In
addition to the wind, this system will bring cooler conditions and
a return to slightly below normal temperatures.
A general trend towards somewhat less uncertainty is noted in the
grand ensemble through much of next week. After the
aforementioned trough moves through early in the week, a series of
discrete and progressive waves is likely to develop. A ridge
Tuesday and Wednesday will translate into a slight warmup,
followed by another trough Thursday. However, latest ensembles and
operational models are in better agreement, indicating the trough
will slide by to our east again with little impact. Otherwise,
NBM PoPs remain near zero through the end of next week.
&&
.AVIATION...Updated at 2320Z.
South-Central Arizona including KPHX, KIWA, KSDL, KDVT:
Light winds, aob 8 kts, will prevail now through Saturday. Wind
directions will continue to favor an easterly component through
midday Saturday, with periods of call and some variability. A
westerly shift is then expected by mid to late afternoon Saturday.
BKN to OVC clouds aoa 15 kft will continue to pass over the area
at times through Saturday morning before clearing.
Southeast California/Southwest Arizona including KIPL and KBLH:
No aviation weather concerns are expected through the next 24
hours. Light winds, generally below 8 kts, will favor the W at
KIPL and N to WNW at KBLH. Extended periods of light variability
are also expected at both terminals. Otherwise, SCT-BKN clouds aoa
15 kft will continue through the rest of today and clear out
overnight.
&&
.FIRE WEATHER...
Drier and warmer weather will spread into the districts the rest of
the week and into the weekend, with temperatures reaching
slightly above normal levels. Afternoon minimum humidity levels
will range generally from 15-20% across most of the forecast area
through Saturday. Overnight recovery will be fair to good in a
30-60% range during this period. Slightly higher MinRH`s expected
late weekend and into early next week. Winds are expected to
remain light and diurnal, with the exception of Friday, where
elevated east to southeast winds are expected during the morning
and afternoon hours. A weather disturbance early next week will
bring somewhat cooler temperatures and locally stronger winds, but
little other negative influence to fire weather concerns.
Overall, conditions will be favorable for prescribed burning
through next week.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...None.
CA...None.
&&
$$
DISCUSSION...Hirsch
AVIATION...Benedict/Smith
FIRE WEATHER...Young
Forecast Discussion:
A very cold and very dry 1040 mb surface ridge is over the Upper
Mississippi River Valley at 20Z. Today`s 12Z observed soundings at
sites behind yesterday`s cold front, including here at TOP, showed
an extremely dry and shallow layer of air just above the surface
with dew points near -40C as that ridge moved into the area. Surface
dew points had dropped a few degrees below zero as boundary layer
mixing increased midday today. Winds have also increased in central
KS where the pressure gradient is stronger on the western flank of
the departing ridge. WAA is setting up as the ridge moves east,
which allowed for a quick warm up today. There will be a brief
period of high fire danger this afternoon due to low RH and
increasing winds.
WAA continues tomorrow. Cirrus clouds will stream over the area and
southwesterly winds will be breezy - sustained between 15 and 25
mph with gusts to 30 or 35 mph in eastern KS. High temperatures
will reach the 50s area-wide tomorrow afternoon. A slight wind
shift will occur with a passing weak surface trough Saturday
night, without much change to ambient conditions for Sunday. An
upper level ridge builds over the central US late this weekend and
southwesterly flow sets up aloft early next week. Temperatures
will approach 60 degrees on Monday before more notable changes
arrive to the forecast by the middle of the next.
A quick moving cold front will move through the area by early
Tuesday as an upper level trough advances across the Midwest. The
better POPs at that time will stay south and east of the CWA.
Models then diverge on outcomes for midweek and beyond with some
showing a cut-off low kicking out into the Plains from the
southwest. NBM has POPs increasing on Wednesday but will have to
monitor for better model agreement before confidence in chances
and timing can increase.
&&
.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 506 PM CST Fri Feb 3 2023
Dry low levels in the atmosphere is expected to keep VFR
conditions in place with only some increasing high clouds as
shortwave energy moves into the Rockies. An increasing low level
jet could pose a wind shear concern mainly for TOP in the river
valley. The HRRR and RAP are showing the surface remaining
decoupled with winds backed to the southeast in the river valley
as the low level jet strengthens. Winds look to remain more
unidirectional at MHK and turbulent mixing is expected to limit
wind shear concerns at FOE and MHK.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Teefey
AVIATION...Wolters