Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 04/16/19
Area Forecast Discussion
National Weather Service Hastings NE
637 PM CDT Mon Apr 15 2019
Issued at 442 PM CDT Mon Apr 15 2019
Added some sprinkles to portions of the area north of Interstate
80 for late this afternoon and evening. Radar composite already
showing some returns north of Ord, and the HRRR shows spotty
activity continuing through around 03Z.
.SHORT TERM...(This evening through Tuesday)
Issued at 329 PM CDT Mon Apr 15 2019
Cirrus continues to stream across the area this afternoon, but it is
thin enough that the sun has warmed temperatures above previous
forecast. A cold front is moving into the northern part of the
forecast area this afternoon.
The cold front that has moved into the northern part of the forecast
area is expected to move through the rest of the forecast area
tonight. Winds will turn to the north/northwest. There could be a
few showers to the north of the front, but at this time, nearly all
of the models keep it to the north of the forecast area. Have
maintained a dry forecast for now, but will have to watch to see
what develops. Despite the cold front and north winds, lows tonight
will be fairly mild.
The next concern comes with the temperatures for Tuesday. The front
moves to the south of the area by morning, but then it lifts back
north a little bit. Temperatures will be a challenge. The northwest
part of the forecast area may be too warm while the southeast too
cool. Not sure how much cool air will filter in behind the cold
front. Have lowered temperatures a little in the northwest. The next
problem is if the front lifts further to the north, the southeast
part of the forecast area could be warmer. Have not changed that,
but will definitely have to watch.
.LONG TERM...(Tuesday night through Monday)
Issued at 329 PM CDT Mon Apr 15 2019
There is an upper level wave that moves into the plains Tuesday
night through Wednesday night. As the upper wave moves in, the front
that lifts north Tuesday during the day will have showers and
thunderstorms develop mainly to the north of the front. With the
front in the southeast during the evening, the better chance will be
further south, but the showers and thunderstorms should lift to the
north as the front lifts north. The northern part of the forecast
area has the best chance during the overnight hours and into the
morning Wednesday. By Wednesday afternoon the precipitation should
start to move out of the area from west to east with only a little
precipitation ending in the southeast during the evening.
There should be a break late Wednesday night into Thursday with dry
conditions. By Thursday afternoon there is another upper level wave
that moves through. This one is not as interesting. Not every model
has precipitation or have it in the same area. Have some light
showers in the east during the afternoon, but not certain there will
be much or where for sure.
The period Thursday night through Saturday should be dry. There is
an upper level ridge building into the area and temperatures will be
warming up again. The next upper level wave will affect the area
from Saturday night through Monday. The best chance will be Sunday
night as the surface cold front moves through the area. Before and
after that, there will be some chances, but not as good of chances.
.AVIATION...(For the 00Z KGRI/KEAR TAFS through 00Z Tuesday)
Issued at 634 PM CDT Mon Apr 15 2019
Rain showers should remain north of KEAR and KGRI through tonight.
Mostly cloudy skies may break up a bit late tonight, but
additional midlevel (still VFR) clouds are expected to move in
Also of note will be the wind shift that is forecast to pass
through the terminals around 02Z this evening. Southerly winds
will become northeasterly, and will eventually become easterly on
Area Forecast Discussion
National Weather Service San Francisco Bay Area
837 PM PDT Mon Apr 15 2019
.SYNOPSIS...Light showers will taper off from north to south this
evening as a frontal system exits the region. Dry conditions are
expected to develop by Tuesday. A warming trend is forecast for
Wednesday and Thursday, with temperatures expected to climb well
above normal by Thursday. A cooling trend is forecast to begin on
Friday and continue into the weekend. Generally dry conditions are
expected over the weekend.
.DISCUSSION...As of 8:35 PM PDT Monday...Latest KMUX radar shows
that the most widespread shower activity is currently over
Monterey and San Benito Counties, with only widely scattered light
showers across the SF Bay Area and Santa Cruz County. This system
has generated only very light rainfall totals with amounts thus
far of less than a tenth of an inch in most locations. Latest HRRR
forecasts showers to taper off overnight as the frontal boundary
moves off to our south and east. Both the HRRR and 00Z NAM
forecast a few showers lingering through mid morning Tuesday
across the far southern portion of our area. But for the most
part, Tuesday is expected to be a dry day with seasonably cool
temperatures in the 60s. Brisk northwest winds are forecast to
develop near the coast during the afternoon and gusts up to 30 mph
are possible in the windiest coastal locations.
An upper ridge over the Eastern Pacific is forecast to build
eastward and over California on Wednesday and Thursday. This will
result in a robust warming trend. Most warming on Wednesday will
be confined to inland areas since light onshore flow will persist
and limit coastal warming. But by Thursday, light offshore flow is
expected to develop which will allow for warming in all areas.
Widespread highs in the 80s are forecast for inland areas on
Thursday, with 70s near the coast. A few coastal locations, such
as Santa Cruz, may reach 80 on Thursday. High temperatures on
Thursday are forecast to be as much as 25 degrees warmer than
The upper ridge will shift to our east and weaken by Friday and
onshore flow will return. These developments will result in as
much as 10 to 15 degrees of cooling in coastal areas on Friday,
while inland areas will experience more modest cooling. Cooling
will continue on into the upcoming weekend as an upper trough
develops over California. This trough may generate scattered
shower activity over northern and central California, but
primarily over the higher mountains such as the Sierra Nevada and
Trinity Alps. Thus, the weekend should be mostly dry and
seasonably cool for our forecast area. Warming is then
anticipated during the early part of next week as an upper ridge
develops over California.
.AVIATION...as of 5:09 PM PDT Monday...VFR-MVFR with isolated IFR
in lowering ceilings and rain; the 00z tafs carry previous thinking
with only a few adjustments to wind speeds. A cold front will sweep
through later this evening with a gradual decrease in showers by late
tonight. VFR forecast on Tuesday.
Vicinity of KSFO...VFR tempo MVFR in lowering ceilings and rain early
this evening, improving weather conditions tonight into Tuesday with
VFR. Statistical guidance has been correct thus far forecasting a W
wind direction occasionally SW, a rapidly approaching surface trough
from the eastern Pacific and exiting surface ridge over the Bay Area
this evening may still turn winds briefly to SE this evening. Otherwise
a west wind through the period becoming gusty early Tuesday afternoon.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR tempo MVFR in lowering ceilings and
rain early to mid evening, improving weather conditions tonight
into Tuesday with VFR.
.MARINE...As of 8:17 PM PDT Monday...A cold front will quickly
move over the coastal waters and bays this evening and overnight.
Winds will shift back out of the northwest tonight behind frontal
passage. Locally gusty winds are expected tomorrow afternoon and
evening, mainly along the coast and over the Monterey Bay.
Moderate northwest swell will continue through the forecast
PUBLIC FORECAST: Dykema
Visit us at www.weather.gov/sanfrancisco
Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Omaha/Valley NE
646 PM CDT Mon Apr 15 2019
.SHORT TERM...(Tonight through Wednesday Night)
Issued at 330 PM CDT Mon Apr 15 2019
We still have a few passing showers through tonight especially
in northeast Nebraska and more showers and thunderstorms Tuesday
night into Thursday. The main change is a southward shift in the
heavier precipitation and severe weather potential.
Temperatures were a little milder overnight in the 30s and 40s with
the stronger south winds. Normal low temperatures are typically
around 40 degrees for this time of year. The spotty light rain
around midnight resulted in a trace at Omaha, Tekamah, and Blair.
Today, temperatures were warming into the 60s and 70s. A few
patchy clouds and sprinkles near the Neb/SD border this afternoon
and showers have been increasing per satellite and radar returns
over central and western Nebraska. The experimental HRRR is a
little farther south with some of the showers compared to the
HRRR/RAP. Did mention some spotty showers tonight. Some elevated
CAPE and a there may be a few isolated rumbles of thunder as the
SREF is showing a 5% thunder in northeast Nebraska this evening. A
weak surface front will sag southward through tonight then still
over southeast Nebraska and southwest Iowa Tuesday. The showers
are the result of weak shortwave trough/channeled
vorticity/increasing warm air advection ahead of the primary
trough that is affecting California.
The mid-tropospheric trough over the West Coast will head toward
the Four Corners region Tuesday evening and toward northern Texas
Wednesday. The northern stream of the trough is leading the
southern trough, spreading the bulk of the rain over the Dakotas
into Minnesota with some showers and thunderstorms locally.
Wednesday night...showers and thunderstorm re-develop in response
to the stalled front in the area and the southern storm lifting
into Kansas and Missouri...as gusty northwest winds overspread the
area. Rain chances linger into Thursday on the cold side of the
storm system with gusty northwest winds continuing. This time of
year, the stronger winds mix down during the day and will have to
assess wind advisory potential.
Above normal temperatures for Tuesday and Wednesday with highs in
the 60s and 70s.
There is some severe weather potential with the front in the area, 1500
to 3000 J/kg MUCAPE, and 0-6km bulk shear of 35 to 45kts Wednesday
afternoon and evening. SPC has shifted the slight risk to the
south but still has southeast Nebraska and southwest Iowa in the
marginal risk for severe weather.
.LONG TERM...(Thursday through Monday)
Issued at 312 PM CDT Mon Apr 15 2019
Energy from the northern stream trough rotates through Thursday
and the mid- level trough shifts to the east Friday. Some
lingering showers Thursday with gusty winds Thursday through
Friday. Winds may approach wind advisory criteria/gust over 40
mph, so will continue to highlight in the hazardous weather
Mid level ridging builds in Friday and continues Saturday. The
next chance for rain is on Easter with another front moving across
the Central Plains.
Cooler Thursday with highs only in the 50s...back in the 60s for
Friday and 70s Saturday...with 60s and 70s for Easter Sunday.
.AVIATION...(For the 00Z TAFS through 00Z Tuesday evening)
Issued at 628 PM CDT Mon Apr 15 2019
Mainly VFR conditions are forecast through Tuesday afternoon as
mid level broken to overcast clouds persist. Scattered showers are
likely across northeast Nebraska, and may affect KOFK through 12Z,
but little if any aviation impacts are expected. A cold front
sliding through the region will turn winds to the north at KLNK
and KOMA by 06Z, with the front stalling over southeast Nebraska
Tuesday. Showers and thunderstorms could develop near the front
Tuesday evening and may affect KLNK and KOMA after this TAF
Area Forecast Discussion
National Weather Service San Diego CA
852 PM PDT Mon Apr 15 2019
A trough will drop south across SoCal on Tuesday, gathering up
Pacific moisture and creating scattered, light showers west of the
mountains. Along the coastal slopes, precipitation will be steadier
and heavier into the evening due to strong, upslope flow. Windy
conditions will prevail over the mountains and deserts through
Tuesday evening. Cooler Tuesday, then warmer through Thursday as a
ridge develops aloft with fair weather, but another weak trough will
deepen the marine layer and bring cooling again over the weekend.
.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
At 8 PM PDT...Satellite imagery showed widespread low clouds over the
coastal waters, extending inland, with higher clouds thinning from
the west. The sfc pressure gradients this evening have been
impressive. At 8 PM PDT...it was over 13 MBS onshore KSAN to SW NV
and 9 MBS KSAN to KTRM. Despite these large numbers, the winds have
mostly been below Advisory criteria. One reason may be due to the
weaker winds aloft at this time. The 00Z Miramar sounding had those
winds only about 15 KTS up through 15K FT. Peak wind gusts have been
in the 40-50 MPH range this evening in the wind-prone areas. The
sounding also showed a 3 degree C inversion based near 2K FT MSL and
PW of 0.58 inch.
The 00Z NAM run continues to show a sharp, digging trough on Tue,
which has been edging a bit more to the west, supporting better lift
and precip chances west of the mts. This trajectory may temper the
stronger winds forecast over the mts/deserts on Tue, but for now,
00Z MOS guidance is similar to previous, so no forecast changes will
be made this evening. Some increase in wind still expected to make
From previous discussion...
High clouds covered the region along with a few low clouds near the
beaches early this afternoon. Temperatures were mostly 5-10 deg F
lower than 24 hours ago. An upper low was near 45N/129 W with a cold
front extending south to a point about 200 miles west of Eureka.
That trough will shift southeast to California by Tuesday with the
trough axis moving through southern California Tuesday afternoon,
though a vorticity maximum will move down the back side late
afternoon/early evening. Moisture is decent with this system with
some saturation up to around 700 MB, and with west winds at 850 MB
between 20 and 35 knots, some orographics will occur along the west
mountain slopes. Precipitation amounts will likely be 1/4 to 1/2
inch, locally more, on the west mountain slopes, but most areas west
of the mountains will only have light amounts, 1/10 inday wch or
less. Precipitation could start as early as very late tonight as
very light showers/drizzle as an eddy will quickly deepen the marine
layer, but best chances of precip will be late morning through
afternoon Tuesday based on the HRRR and local WRF. Snow levels will
mostly be at/above 7000 feet, and snowfall likely will just be 1-2
inches at the highest San Bernardino/Riverside County peaks. The
biggest concern Tuesday and Tuesday night will be the wind, with
gusts over 55 MPH likely on the desert mountain slopes and desert
foothills, though some gusts could locally approach 55 MPH tonight.
Timing of the strongest winds vary a bit with the models, but 3 PM-
10 PM appears to be the most likely for strong winds there,
including in the lower parts of Coachella Valley. The wind advisory
has been temporally expanded to include tonight as well as later
Fair weather will return by Wednesday as the trough shifts east and
is replaced by a transitory ridge. Current guidance suggests that
the offshore flow in mainly the mountains will be rather weak
Wednesday morning. After a day with temperatures 5-15 deg F below
normal Tuesday (greatest in the inland valleys and mountains),
Wednesday should recover to near normal, and Thursday and probably
Friday should be several degrees above normal. The marine layer
stratus should be minimal Wednesday afternoon through Friday. A
possible weak closed upper low Friday could mess with the details
and, if anything, could bring a bit of offshore flow to warm up the
coastal areas. Another trough of low pressure will move through the
region this weekend with more cooling and possibly strong winds in
the mountains and deserts, though model variability, including with
GFS ensemble members, is rather high for timing and if we have a low
closing off over the region. There could be a few showers with the
trough as well based on the GFS solution of a deeper low, but ECMWF
keeps us dry. For now, will lean towards ECMWF solution, which many
of the GFS ensemble members lean towards as well. Regardless, lack
of deep moisture will preclude any significant rains.
160300Z...Coast/Valleys...BKN-OVC15-025 tops 040 moving into the
valleys tonight with spotty drizzle or light rain through 16Z
Tuesday, followed by scattered light showers from 16Z-23Z. Vis
briefly falling to 5 miles at times in -SHRA. SSW winds 5-10 kt
ahead of the cold front Tuesday morning shifting west 10-20 kt with
cold frontal passage after 19Z.
Mountains/Deserts...Stratus/fog moving inland over the foothills and
western mountains slopes after 09Z with fog reducing vis to 1-3
miles in the mountains through Tuesday afternoon. Showers will be
most widespread Tuesday afternoon and evening. West winds 15-25 kts
with gusts to 40 kts with STG UDDFTS and wind shear in the adjacent
deserts through Tuesday afternoon. Rotors most likely at KPSP
between 10-18Z Tuesday.
Gusty west-northwest winds Tuesday afternoon from 15-20 kt with a
few gusts near 25 kt through early evening, mainly over the Outer
Waters. Combined seas Tuesday afternoon and evening from 5-6 FT.
Winds and seas subsiding Tuesday night.
Spotty drizzle or light rain early Tuesday morning, followed by
scattered showers late morning into the afternoon with the passage
of a cold front.
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.
CA...Wind Advisory from 5 PM this afternoon to 2 AM PDT Wednesday for
Apple and Lucerne Valleys-Coachella Valley-Riverside County
Mountains-San Bernardino County Mountains-San Diego County
Deserts-San Diego County Mountains-San Gorgonio Pass Near