Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/05/21
Area Forecast Discussion
National Weather Service Bismarck ND
934 PM CST Thu Mar 4 2021
.UPDATE...
Issued at 934 PM CST Thu Mar 4 2021
There are some hints of fog developing in northwest North Dakota,
and to the south and west of the Devils Lake Basin. Based on
previous nights` model vs. observation performance of low-level
moisture fields, we are very reluctant to increase messaging of
fog potential until we see something more prominent. The greatest
potential for impactful visibility reductions is across the 4
northwestern-most counties of North Dakota, where snow cover
still exists and dense fog is climatologically more common (at
Stanley and Tioga).
Model consensus for sky cover remains very poor. It is
under-performing on high clouds across southwest North Dakota and
over-performing on low clouds across northern North Dakota,
although there are signs of developing fog in some similar
locations. The first several hours were adjusted to more closely
follow observed trends.
UPDATE Issued at 622 PM CST Thu Mar 4 2021
Some minor adjustments were made to the coverage of patchy fog
tonight through tomorrow morning. The HRRR and RAP visibility
fields were relied upon, as they have been trending well with
observed surface dewpoints. However, it`s worth noting that all
guidance, especially non-HRRR/RAP solutions, has been far too
aggressive with both the coverage and duration of low stratus and
fog the past few nights. For this reason, we also trended sky
cover down with this update. Even though our forecast grids will
contain 30-70% sky cover for much of the area, think that most
locations will either be completely overcast or completely clear
at any given time.
&&
.SHORT TERM...(This evening through Friday)
Issued at 113 PM CST Thu Mar 4 2021
Low stratus and fog tonight and continued mild temperatures
tomorrow highlight the short term forecast.
Tonight, easterly surface flow will bring in a shallow layer of
moisture (enhanced by continued snow pack melting) across central
and eastern ND. Forecast sounds depict low stratus between
500-1000 feet AGL and some fog as a result. There is some
uncertainty as to the extent and duration of the stratus/fog. Some
short-term models want to take it as far west as Dickinson and
leave Jamestown clear, while the majority maintain a further east
solution.
How long clouds/fog persist will play a significant
role in temperatures tomorrow. We still maintained a warmer
forecast than what the NBM is providing due to its continued cold
bias, but we elected to go below the higher end thresholds we`ve
been trending with as of late. We still expect the southwest will
see temperatures in the 60s tomorrow, but further east where cloud
cover is more likely and more likely to linger longer,
temperatures could struggle to get out of the 40s to lower 50s.
.LONG TERM...(Friday night through Thursday)
Issued at 113 PM CST Thu Mar 4 2021
Mild and dry conditions continue through much of the long term
before a potentially more active pattern sets up next week.
Saturday will likely be the warmest day through the next week as
an upper-level ridge axis moves directly overhead. Therefore,
maintained higher than straight NBM temperatures which brings
widespread upper 60s into portions of the west and widespread
upper 50s to low 60s everywhere else, except for the Turtle
Mountains. This is slightly cooler than the previous forecast as
the cold front appears to be slightly delayed. This means
compressional warming will be maximized a bit further west and a
southeasterly (which doesn`t mix down as well as southwesterly)
wind will be favored all day. Winds will be quite breezy Saturday
afternoon with southeasterly winds around 25 mph gusting to 35
mph. This may lead to near critical fire conditions across the
southwest Saturday afternoon where temperatures will be in the
upper 60s, relative humidity around the low 20s and winds around
30 mph. Sunday will not be as warm, but highs should remain well
above normal with widespread readings in the upper 40s to upper
50s.
The flow becomes more zonal on Monday as a broad western trough
approaches Tuesday into Wednesday. This could be the start of a
more active period. The 12z suite of deterministic global models
have trended towards the flow staying split over the Dakotas
before phasing across the Great Lakes, keeping the strongest
cyclogenesis well to our east. Still, warm air advection
associated with the northern wave stream would still bring us a
brief period widespread precipitation in this scenario, but the
impacts would be fairly tempered. The 12z ensemble guidance has
shifted their favored storm track a bit north and lowered their
expectations of more meaningful precipitation. Overall,
expectations remain low in this system producing impacts or much
needed rain, but a great deal of uncertainty remains so there is
still the possibility however small it might be.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 622 PM CST Thu Mar 4 2021
Patchy fog with associated LIFR ceilings may develop across much
of western and central North Dakota tonight through Friday
morning. Confidence in impacts at any given terminal remains low,
so have opted to include VCFG and SCT003 mentions for this set of
TAFs. Otherwise, VFR conditions and light easterly winds are
expected through the forecast period.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...Hollan
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...Hollan
Area Forecast Discussion
National Weather Service Dodge City KS
549 PM CST Thu Mar 4 2021
...Updated aviation discussion...
.SHORT TERM...(This afternoon through Friday night)
Issued at 1200 PM CST Thu Mar 4 2021
Closed cyclone tracking across southern Colorado right on schedule
at midday, with the associated surface low organizing over SE
Colorado. Forcing for ascent and diffluence aloft continue to
increase at midday, and southeast winds will continue to increase
for the next several hours, gusting over 30 mph. Paltry moisture
advection continues, with dewpoints now into the upper 30s. There
is not much moisture to tap upstream in Oklahoma; only expecting
low to mid 40s into SW Kansas by late afternoon and evening.
Additional moistening is ongoing from aloft, with widespread virga
already present visually and on radar. 12z NAM is focusing its
instability axis (MU CAPE of 500-1000 J/kg) from roughly the Dodge
City vicinity to the Red Hills by early this evening. This is
actually a very favorable setup for severe convection, given the
diurnal timing, lift/forcing, and shear....minus the needed
moisture and instability. Some strong to marginally severe low
topped storms/supercells are plausible this afternoon and evening,
as mid level cold advection continues over minimal boundary layer
moisture. Marginal hail (quarters or less) and wind gusts (< 60
mph) are possible. Measurable rain will be scattered around with
this activity, but confidence on the widespread beneficial
rainfall remains focused overnight, in the deformation zone north
of the southeast-digging mid level cyclone as it tracks into
western Oklahoma by sunrise Friday. Storm total QPF grids still
show a widespread 0.25-0.50 inch rainfall, and HRRR guidance
suggests most of this will fall between midnight and sunrise
Friday. Temperatures will remain well above freezing through this
entire event, and all precipitation will fall as rain. Winds will
be quite elevated and gusty from the northeast during the rain,
gusting over 30 mph. Temperatures sunrise Friday in the upper 30s
and lower 40s.
Light rain will linger across especially the southern zones for
the first few hours of Friday morning, with some more measurable
QPF mainly south of US 50. Widespread stratus and low clouds will
prevail Friday morning, but rapidly dissipate through the
afternoon amid strong subsidence. Models do show minimal cold
advection behind the departing trough, with a net decrease of
about -3C at 850 mb versus Thursday, but with plenty of early
March afternoon sun, mid to upper 50s are still expected. NE winds
of 15-25 mph will gradually weaken through late afternoon.
.LONG TERM...(Saturday through Thursday)
Issued at 135 PM CST Thu Mar 4 2021
The forecast is completely dry, Saturday through at least Tuesday.
Broad high pressure ridging will provide for a fantastic early
spring weekend. Afternoon temperatures will be recovering through
the 60s Saturday and Sunday, but the typical Kansas south winds of
20-30 mph will be blowing both afternoons. Still a bargain for
early March.
More of the same Monday, windy and warm, as flow aloft begins to
trend SWly in response to an expansive long wave trough arriving
in western North America. Afternoon temperatures in the lower 70s.
We continue to monitor Tuesday for potentially extreme danger of
wildfire spread. Model consensus places primary lee cyclone
(<996 mb) in the vicinity of SW Nebraska 6 pm Tuesday, with a
strong dryline trailing southward through the high plains.
Pressure gradients will be tight, with the tightest gradients
likely east of the dryline in central Kansas (850 mb winds of
45-50 kts). Still, locations behind the dryline will likely be
windier drier and warmer than any guidance, and will likely have
fire weather headlines Tuesday. Afternoon temperatures from the
NBM were near 80 and were accepted.
Synoptic pattern appears decidedly springlike mid next week, with
a strong established dryline and convective potential given
strong SWly flow aloft. Expansive longwave trough across the
Rockies Wednesday will edge out onto the plains late Wednesday.
Details will waffle this far out, but the deterministic 12z ECMWF
currently suggests severe convection late Wednesday from the
southeast zones northeast through central/NE Kansas. This severe
potential will have to be watched closely, given a strong SWly jet
aloft and an open gulf, but climatology says most will be
southeast of SW Kansas. Cold frontal passage is expected Wednesday
night, followed by cooler/more stable air Thursday.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 549 PM CST Thu Mar 4 2021
An upper level low pressure system over southeast Colorado will move
into eastern Oklahoma by midday Friday. Initially, the area will see
VFR cigs and scattered showers with isolated thunderstorms this evening.
MVFR to IFR cigs will develop late this evening through the overnight
hours along with a switch to northeast winds. Areas of rain will increase
in coverage across central/west central Kansas late this evening and
spread southward through southwest Kansas late tonight into early Friday.
Conditions will be improving across the area from north to south late
Friday morning into Friday afternoon as the upper level system pulls
away from the region.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 41 61 32 65 / 90 40 0 0
GCK 40 59 30 64 / 90 30 0 0
EHA 39 57 31 64 / 40 60 0 0
LBL 38 57 31 63 / 50 60 0 0
HYS 40 60 30 67 / 90 20 0 0
P28 43 59 34 65 / 90 60 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...Turner
LONG TERM...Turner
AVIATION...Gerard
Area Forecast Discussion
National Weather Service Marquette MI
534 PM EST Thu Mar 4 2021
.SHORT TERM...(This evening through Friday)
Issued at 241 PM EST THU MAR 4 2021
Current RAP analysis and GOES WV imagery show an upper level low
over Quebec today and will likely hang around through Friday that
will continue to bring weak northerly flow over the Upper Peninsula,
resulting in some flurries or very light snow showers along the Lake
Superior shoreline. This has gradually diminish throughout the
afternoon with dry air aloft moving over the area. Soundings show an
inversion around 850-900mb that will help dry things out which has
occurred earlier than anticipated and will have winds back a bit
more to the northwest and this will bring slight chances of light
snow showers east of Munising late tonight or early Friday morning.
Temps at 850mb on Friday morning will be between -10C to -12C which
will support light snow showers over those areas through the morning
hours. Not expecting much in terms of accumulations with generally
around a half-inch or less. Elsewhere, it will continue to remain
dry with clouds over the north and east and partly to mostly sunny
skies across the south and west.
Temperature wise, it will be pretty similar to what we saw for highs
yesterday with mainly 20s across the north and east with 30s over
the south and west along the WI border where there will be more
sunshine. Seeing some breaks in clouds earlier than anticipated and
that has allowed temps to rise quickly over the west and as a
result, have raised highs for today. Lows tonight could get chilly
again over the interior west similar to last night where some spots
fell below zero with mainly clear skies at Wakefield and Watersmeet.
Would not be surprised if this were to occur again tonight. Highs
Friday will be a little warmer than today with widespread 30s and
maybe a few low 40s over the far south.
.LONG TERM...(Friday night through Thursday)
Issued at 515 PM EST THU MAR 4 2021
Overall, quiet weather will prevail across Upper MI thru early next
week. This quiet period will be the result of sharp ridging/strong
positive height anomalies developing from the High Plains to Hudson
Bay thru Sat. The ridge will then shift across the western Great
Lakes on Sun, followed by a weak shortwave trough passage on Mon and
then rebuilding of a ridge into the Great Lakes for Tue. Heading
into the middle of next week and on into the mid Mar period, there
are indications for an active pattern to develop, featuring at least
a couple of waves dropping into the western U.S. and then ejecting
ne across the Plains. The first wave will arrive midweek with
majority of the pcpn for Upper MI probably being rain. A second wave
may affect the Great Lakes region late in the week. Temps next week
will trend overall above normal in this pattern, but will be
dependent on the track of shortwaves/associated low pres systems
lifting across the central U.S. If passing to the w of Upper MI,
some warm days will be in the offing. With the first wave likely
passing w of Upper MI, it looks like some 50s will be observed Mon
and especially Tue, at least over western Upper MI. Wed could be
warm as well, depending on timing of cold fropa associated with the
first wave.
Beginning Fri night into Sat, it looks like another shortwave will
drop sse, passing across far eastern Lake Superior. Several of the
models indicate CAA may drop 850mb temps back toward -13C across
eastern Lake Superior which could result in around round of flurries
off the lake into the eastern fcst area late Fri night/Sat morning.
Under near calm wind and mostly clear skies over the w, temps Fri
night will fall back into the single digits above 0F in the
interior. Expect mainly teens elsewhere. Highs Sat should be similar
to Fri ranging from around 30F north central and east to near 40F
along the Wisconsin-Michigan stateline.
Sfc high pres ridge will finally shift e across the area Sat night.
Central and especially the eastern fcst area should be under the
ridge axis and near calm wind long enough for temps to fall back
into the single digits above 0F in the interior. A few spots could
slip blo 0F.
As shortwave trough moves out over the Canadian Prairies and
northern Plains on Sun, the mid-level ridge will shift across the
western Great Lakes. As the associated sfc high pres ridge pushes e
of the area, southerly winds be the rule. High temps should push
well into the 40s, maybe above 50F, over portions of western Upper
MI. Expect 30s for much of the east half.
The northern Plains shortwave trough will then move across the area
late Sun night/Mon morning. Given limited moisture and weak forcing
could maybe see some light shra across the north and east with this
feature. Will maintain slight chc pops from the Keweenaw into the
eastern fcst area. Broader mid-level ridging will then develop over
the eastern U.S. into Tue as mid-level troughing expands across the
western U.S. Lead shortwave with this western trough will begin to
eject out across the Plains, but should remain far enough to the w
for mostly dry weather to linger into Tue. Temps Mon and especially
Tue, when best WAA is occurring ahead of the incoming Plains system,
will likely rise into the 50s F over portions of western Upper MI.
However, Mon could be a surprise warm day with temps well into the
50s across portions of the w half of the fcst area as skies clear
after shortwave passage in the morning. Temps will be coolest closer
to Lake MI both days.
The shortwave ejecting out of the western CONUS trough will support
a low pres wave which model consensus indicates will likely pass
just w of the fcst area as it lifts ne on Wed. GFS is one of the few
models showing the low passing over the central U.P. Pcpn associated
with this system will spread into the fcst area in the Tue night/Wed
time frame. At this point, it appears this will be mainly a rain
event. Will turn cooler in the wake of the system on Thu with some
lingering -shsn in the morning.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 534 PM EST THU MAR 4 2021
VFR conditions will continue through the period at IWD and CMX. SAW
could see some MVFR conditions Fri morning...otherwise it will be
VFR there.
&&
.MARINE...(For the 4 PM Lake Superior forecast issuance)
Issued at 241 PM EST THU MAR 4 2021
Wind will generally remain 20 knots through early Friday as a
surface high pressure continues to dominate the Great Lakes region.
Winds will increase to around 20 knots over the east half of the
lake by Friday afternoon and evening with gusts to 30 knots and
can`t rule out a few gale force gusts as well. Winds will slowly
diminish through the day Saturday, falling below 20 knots by
Saturday afternoon. Winds will shift to more of a southerly flow by
Sunday as the ridge shifts east a little and could have another
quick shot of winds of 20 to 30 knots Sunday afternoon and evening
before falling under 20 knots Monday.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
Upper Michigan...
None.
Lake Superior...
None.
Lake Michigan...
None.
&&
$$
SHORT TERM...JH
LONG TERM...Voss
AVIATION...07
MARINE...JH
...Update to aviation forecast discussion...
.DISCUSSION...
Issued at 259 PM CST Thu Mar 4 2021
It has been another pleasant day weather-wise with temperatures
reaching the low 70s for a second day in a row. Light rain will be
possible for some tonight/early tomorrow. Otherwise, warmer than
average temperatures remain the rule this forecast package.
As of this afternoon, a mid-level closed low was spinning over
Colorado. Clouds associated with that system were evident on
visible satellite imagery over western KS, and radar was showing
some shower activity and even a few lightning strikes in that part
of the state. Closer to home, skies remained mainly sunny with a
warm and continued very dry air mass in place. Mixing of the PBL
has been allowing drier low level air to mix down to the surface,
effectively dropping dew points and relative humidity values again
this afternoon. As such, widespread very high fire danger will
remain in place until after sunset when RH values increase and
breezy southeast winds subside.
The storm system over CO will pivot southeastward into Oklahoma by
tomorrow morning. Light rain will continue to be possible through
that timeframe, primarily over central and southeast KS. The rain
may clip the extreme southern and southwestern CWA tonight, but
chances remain on the low side due to weak lift and lack of deep
layer moisture -- RAP and HRRR profiles both show a layer of dry air
from the surface up through about 700 mb. Cloud cover associated
with tonight`s system will clear through the day tomorrow. The
absence of any impactful systems this weekend will allow for
continued enjoyable conditions.
The pattern is expected to become increasingly active next week.
Long range models are in better agreement today with the timing and
placement of a cold front that could impact the forecast area
midweek. Theta-e advection ahead of the boundary would increase
instability and could result in thunderstorms developing along the
front late Wednesday or early Thursday. Trends will be monitored to
fine tune details of the as this timeframe approaches.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 530 PM CST Thu Mar 4 2021
Conditions are expected to remain VFR through the period. Winds
weaken this evening becoming east-northeasterly under 10 kts
through the day Friday. Clouds increase tonight as a system
tracks across western Kansas although associated precip and MVFR
cigs are expected to remain south of terminals.
&&
.FIRE WEATHER...
Issued at 259 PM CST Thu Mar 4 2021
Very high fire danger continues this afternoon.
As expected, afternoon RH values have fallen to around 20 percent
across much of the region and southeast winds have increased,
especially in central Kansas where gusts exceed 20 mph. Conditions
will not improve until just after sunset, at which time the RH
should start to increase and winds should subside slightly.
&&
.TOP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
DISCUSSION...Teefey
AVIATION...Flanagan
FIRE WEATHER...Teefey