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 .AVIATION... 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. 44 && .PREV DISCUSSION...235 PM MST Thu Dec 5 2019... .SYNOPSIS... 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. && .DISCUSSION... 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 night. 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. Guyer/15 && .FIRE WEATHER... 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 expected. Guyer && .ABQ WATCHES/WARNINGS/ADVISORIES... None. && $$
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
622 PM EST Thu Dec 5 2019 .AVIATION... 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 terminal site. DTW THRESHOLD PROBABILITIES... * Low for ceilings aob 5000ft tonight, moderate overnight. && .PREV DISCUSSION... Issued at 351 PM EST Thu Dec 5 2019 DISCUSSION... 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 snow. 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. MARINE... 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 the region. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...NONE. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....99 DISCUSSION...DRK MARINE.......JVC You can obtain your latest National Weather Service forecasts online at