Forecast Discussions mentioning any of
"HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 12/06/19
Area Forecast Discussion...UPDATED
National Weather Service Albuquerque NM
505 PM MST Thu Dec 5 2019
00Z TAF CYCLE
Precipitation will gradually taper off, and wind speeds will
gradually weaken, across northeast NM through the evening. High
clouds will then arrive from the west tonight. There will probably
also be an area of low clouds that will produce MVFR and IFR
conditions across the northwest highlands from around Cuba and Chama
westward to almost Farmington. There may also be patchy low clouds in
the west central valleys, perhaps impacting Gallup toward morning.
The high clouds should limit radiational cooling some with a
resultant inhibition of some of the low cloud development. Low clouds
will burn off gradually Friday morning, and high clouds will
gradually clear from the northwest through the day.
.PREV DISCUSSION...235 PM MST Thu Dec 5 2019...
The storm system that brought mountain snow as well as windy
conditions to the eastern plains will exit later tonight. A dry
backdoor cold front will then move across the eastern plains
overnight, but an overall quiet night is expected. Temperatures will
be cool on Friday, especially in the east in the wake of the
backdoor cold front. The next storm system to impact the state will
arrive Sunday, bringing another round of rain and mountain snow to
western and northern New Mexico through Monday. Quiet conditions then
continue again through mid-week as temperatures warm to near normal.
SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)...
Water vapor imagery today shows the core of the upper level low
pressure system ejecting eastward across the Front Range of the
Rockies. A well-defined dry slot within the base of the upper low
along with deepening surface low pressure over northeastern NM has
allowed for widespread windy conditions across the plains. The
current Wind Advisory will continue as planned through 5 pm. Cold
advection with moist and unstable orographics over the northern
mts will allow snow to continue along west slopes for a couple more
hours. The latest HREF and RAP guidance shows snow tapering off
quickly by late day. The Winter Wx Advisory will be cancelled once
radar indicates precip exiting the area.
12Z/18Z near-term BUFKIT profiles indicate potential for patchy fog
overnight around northern and western valleys. Meanwhile, a back
door cold front will slide thru eastern NM in the wake of the
departing upper wave tonight. This front will trend temps several
degrees cooler for Friday across the plains. Winds will however be
lighter statewide on Friday as a weak shortwave ridge crests over
the state. A thick band of high clouds will move east over the state
Friday afternoon which will lead to filtered sunshine and make it
feel even cooler. High clouds will continue sliding overhead Friday
LONG TERM...(SATURDAY THROUGH THURSDAY)...
A weak surface low will develop over southeastern CO Saturday, and as
a result, winds will increase across eastern NM, particularly the
I-40 corridor from CQC to TCC. Did increase winds with this package,
but speeds remain below advisory thresholds. Otherwise, temperatures
across the east should warm about 10 to 15 degrees compared to
Friday due to downsloping winds. It should be a gorgeous Saturday
though with warmer temperatures and dry weather.
The next storm system that will impact portions of the state will
move into the Great Basin area on Sunday. Ahead of this upper-level
trough, subtropical moisture will stream into western NM. This will
help generate showers across the west early Sunday before the main
trough passes over northern NM on Monday. With 700mb temperatures
around -1 to -3C Sunday, snow levels will start high, keeping snow
primarily over the Chuska and northern mountains. As 700mb
temperatures fall to -4 to -6C early Monday behind a cold front,
some lower elevation areas could see light snow has snow levels fall
between 5500 and 6500 feet. Accumulating snow is expected to remain
in the high terrain though where the northern mountains could pick
up a few inches of snow. This system will move through too quickly
for anything significant, however.
That system exits Monday night, and then quiet weather conditions are
anticipated through Wednesday as a weak ridge builds over the area.
Another weak disturbance could then clip northern NM Thursday. This
system looks to be drier, but it could bring cooler temperatures and
breezy conditions toward the end of the week.
Strong west winds across parts of eastern NM and light snow over the
northern mountains will exit the area tonight. Poor ventilation with
lighter winds and cooler temperatures are on tap Friday. West winds
will increase again Saturday ahead of the next storm system. Another
round of valley rain and mountain snow will develop across northern
and western NM Sunday and Sunday night. Cooler and drier conditions
will arrive in the wake of this system with periodic breezy winds
over eastern NM through Tuesday. Ventilation will be poor to fair
most days except Sunday and Monday when temporary improvement is
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
622 PM EST Thu Dec 5 2019
Advancing low pressure system across the Midwest has allowed low-
level flow to back to the southwest this evening, which has
maintained dry low-levels through the column. As a result, VFR
conditions are expected to persist through the start of the TAF
period. A series of frontal boundaries will then move across the TAF
sites tonight and overnight caused by the passing low pressure
system, which will maintain the mid-level cloud deck and will result
in the quick veering of surface winds from southeast to northwest.
The area of interest for this TAF period will be the passage of the
cold front, set to sweep across the terminals from 06Z-14Z which will
result in the gradual lowering of cloud bases down to MVFR. A brief
gust around 20 knots will be possible along the leading edge of the
front, with better chances to see more persistent gusts around 20
knots during the daylight hours as post-frontal cold air increases
mixing depths aloft. A dry airmass to then quickly fill in behind the
cold front which will act to eventually scour out cloud cover later
in the day. Went with a more pessimistic, late clearing out time
compared to some models as northwesterly flow will likely tap into
Lake Michigan moisture which would allow residual moisture to hold
under an inversion. Last, removed mention of snow from MBS site as
latest guidance holds bulk of precipitation to the northeast of the
DTW THRESHOLD PROBABILITIES...
* Low for ceilings aob 5000ft tonight, moderate overnight.
Issued at 351 PM EST Thu Dec 5 2019
Clouds on the increase through the afternoon as mid level moisture
advects in ahead of a clipper that will sweep across Mid/Northern MI
tonight. A dry layer currently between 3-8kft will take a bit to
overcome as evident in upstream obs failing to report any precip
hitting the ground under the increasing coverage of radar returns.
The clipper will strengthen while passing over lower MI with the
leading arm of the warm front igniting some light snow showers
around 03Z after saturation has occurred. This initial activity will
fall over northern parts of the Saginaw Valley and Thumb with some
expansion southward as the low draws nearer. Highest confidence is
placed over the Thumb which has the highest amount of QPF, the
coldest air and best mid level forcing. Lower confidence for both
POPs and thus any accumulations (of rain or snow) farther south as
soundings show the dry air holding firm south of about I69.
Soundings have also been consistent in the picture they paint of the
thermal profile adding some question to ptype. A deep moist layer
from the sfc to 12kft is advertised by the NAM, GFS, RAP with only
the very top of this layer tapping into the air at or below -10C and
weak lapse rates throughout the column. As the night goes on the
depth of the moisture decreases while losing connection with this
snow growth zone making a rain/snow mix more likely. Locations
around I69 or south may get all rain but with surface temps very
near 32, don`t expect too much freezing to occur. Models have been
trending a bit higher with moisture content and strength of the fgen
band with the best forcing being located just to the north of SE MI.
Have made minor adjustments to push back timing slightly and
increase potential snow totals over Huron County to around an inch,
possibly up to 2 inches if the best forcing and moisture (closer to
0.2 inches) can shift south slightly. Otherwise most locations north
of I69 should see more like a half inch with some mix of rain and
Northwest flow sets up for Friday as the clipper pulls off to the
east and longwave ridging builds across the central conus. Area of
surface high pressure will encompass the Great Lakes leading to a
cold (highs in the mid 30s) but dry day. Subsidence and dry air
could bring about a good deal of sun through the afternoon. Cold
temperatures hold through Saturday but the surface ridge axis passes
during the day which flips the flow to warmer southwest flow. It
will take til Sunday for temps to respond as the thermal ridge folds
into the region, but highs will then jump to the mid/upper 40s for
both Sunday and Monday.
Next trough will start to push south into the northern Plains and
Midwest Sunday night. The initial low over northern Ontario will lay
out a front that will push south through the Great Lakes Sunday
night. Meanwhile a strong southern stream jet working through the
central Plains will result in the development of a low that will
then strengthen while lifting northeast along the front through
lower MI. Warmth of the resident airmass and track of the low
through Mid MI will result in a rain event across SE MI Monday and
Monday night, with a chance to switch to snow on the tail end behind
the cold front overnight. An arctic front will quickly follow on
Tuesday ushering in a cold airmass with 850mb temps around -20C. The
tight westerly gradient on the backside of the exiting low and surge
of cold air should be enough to excite lake effect snow off Lake MI
in which would last through the day Tuesday.
The arctic air and surface high pressure drifting across the Ohio
Valley mid week could lead to daytime highs Wednesday only in the
low 20s, dipping into the low teens Wednesday night. The coldest air
should then pull away by Thursday allowing temps to slowly
moderate through the end of the week.
Period of light southerly wind as a weak low transits the waters
tonight will be brief as it exits east to New England by Friday
morning. In its wake, strong northwest wind will develop and gust to
near-gales again on Friday afternoon. The prolonged northwest fetch
will likely warrant small craft advisories for elevated waves along
the exposed nearshore waters of the Thumb. Flow then veers to
southwesterly as warm air floods into the Great Lakes region late
Saturday into Monday, gust potential limited by the stable southerly
fetch. Conditions become more unsettled for the remainder of next
week as the pattern becomes more active and colder air filters into
Lake St Clair...NONE.
Michigan waters of Lake Erie...NONE.
You can obtain your latest National Weather Service forecasts online