Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/24/18

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1157 PM EDT Fri Mar 23 2018 .AVIATION... High pressure anchored over northern Ontario will sustain northeast flow across the area throughout the TAF period. This will generally maintain a dry low level environment, supporting predominant VFR conditions. Small window does exist Saturday morning for some degree of MVFR stratus development given the prevailing cold flow off Lake Huron. Greater inland penetration of this moisture will be limited given the existing deep dry layer, but some potential remains mainly at MBS late morning. Any emerging stratus should progressively scatter out under daytime mixing by afternoon. Northeast winds increasing to 10-15 kts during the daylight period. /DTW THRESHOLD PROBABILITIES... * None && .PREV DISCUSSION... Issued at 404 PM EDT Fri Mar 23 2018 DISCUSSION... Combination of high amplitude midlevel ridge from the central Plains northward through Canada and well defined upper level confluence will lead to surface high pressure over the the Great Lakes this weekend. Deep, persistent anticyclonic flow lower column cold air advection, promoting very stable conditions from approximately 2.5 to 20 kft agl over southeastern Michigan. Impressive stability and amount of dry air as RAP soundings suggesting that PWATs will be as low as 0.07 inch by Saturday evening. Omega blocking will take root throughout the weekend with geopotential heights ballooning to the northeast through Hudson Bay. This will actually cause some retrograding of the surface ridge back into the state to close out the weekend. Low impact weather for Saturday as tight area of deformation will remain south of Southeast Michigan. This will keep the low track and precipitation over southern Indiana. Good bet for high cloud veil to extend northward south of I 96 corridor, but uncertainty exists on opacity of the cloud. Solid northeast flow directly into the state will lead to little movement on temperatures. Highs will range in the lower 40s for much of the area, lower 30s in the Thumb. Surface and midlevel ridge axes will remain back in place over Michigan Sunday. Cold anomaly is shown to advect into eastern portions of the area while undergoing heavy modification. Despite what should be again full insolation, temperatures will likely be a few degrees colder particularly for the far eastern areas. Highs Sunday will be in the 30s to near 40 degrees. High pressure departing eastward on Monday will maintain one final day of dry conditions. Meanwhile, an upper level ridge axis crossing the region will bring increasing southerly flow through the day allowing highs to make a run for the low 50s. A string of disturbances ejecting out of a longwave trough over the Western US along with increasing moisture under deep southerly flow will bring the next chance of widespread rainfall to the region early Tuesday through early Wednesday. A frontal boundary crossing the region Wednesday will then end rainfall as a push of slightly drier air arrives late Wednesday. Mild conditions look to continue through midweek with highs in the low to mid 50s. Will then need to monitor the potential for another round of precipitation late next week as a southern stream wave ejects out of the Southwest US while a northern stream wave brings a push of colder air to the region. MARINE... Strong high pressure over James Bay tonight will maintain northeast winds of 15 to 25 knots over Lake Huron right through Saturday night, with winds just modestly decreasing on Sunday. Elevated waves in excess of 4 feet will persist over much of southern Lake Huron, and small craft advisories remain in effect. High pressure reaching the East Coast early next week will allow winds to shift to the southeast and increase, with gusts approaching gale force over the open waters of Lake huron as a frontal boundary moves through during the mid week period. && .DTX WATCHES/WARNINGS/ADVISORIES... MI...NONE. Lake Huron...Small Craft Advisory until noon EDT Sunday for LHZ421-441>443. Small Craft Advisory from 8 AM Saturday to noon EDT Sunday for LHZ422. Lake St Clair...NONE. Michigan waters of Lake Erie...NONE. && $$ AVIATION.....MR DISCUSSION...CB/JD MARINE.......CB You can obtain your latest National Weather Service forecasts online at
Area Forecast Discussion
National Weather Service Sioux Falls SD
654 PM CDT Fri Mar 23 2018 .UPDATE... Issued at 646 PM CDT Fri Mar 23 2018 Radar filling in dramatically at this time lending confidence to the winter headlined areas. Southwest MN still looks to run the biggest risk of accumulating snowfall as the precipitation works its way eastward during the mid and late evening hours. Will watch for the possibility of thunder snow in southwest MN and extreme northwest IA which could really enhance snow rates briefly. However, indications off of the latest RAP and NAM show elevated MU CAPE values greatly decreasing between 00Z and 02Z, and remain in our southern zones across the southern half of the rain shield. Soundings also indicate that there could be some sleet mixed in with the rainfall under the higher reflectivity returns this evening. Interesting how the 12Z simulated comp reflectivity off of the ARW and NMM are actually quite accurate right now. Both of their 00Z reflectivity prognosis have the heavier returns very close to the MO River valley, which is not too far south of where the current activity is. The HRRR and experimental HRRR have been struggling with this precip, although the latest HRRR has improved. && .SHORT TERM...(This evening through Saturday) Issued at 341 PM CDT Fri Mar 23 2018 Forecast broadly remains on track for the CWA. Open wave currently ejecting off the Rocky Mountains will translate eastward this afternoon along the nose of an upper jet, bringing broad lift to the region. This lift will interact with a frontogenetic layer around 850mb to lead to widespread precipitation by 00z. Main source of uncertainty with the precipitation remains type, as surface temperatures will be around 32 degrees as precipitation begins. Temperatures have remained cool into the early part of the afternoon so am not worried about rain failing to switch over to snow. Snow to liquid ratios remain low as -12C heights look to be around 15kft, which supports a wet snow solution. Main tweak to the forecast was delaying the onset of precipitation and lowering amounts slightly in deference to the relatively dry easterly flow that is ongoing today. Snow amounts will remain robust in southwest Minnesota as a quick changeover to snow is expected. The wild card is potential convection in southwest Minnesota. Progged soundings show elevated CAPE at or less than 50 J/kg that is spotty both spatially and temporally. While the trend has been away from getting convective snows, will stick with winter storm warning despite borderline snow amounts, just in case. Saturday will be cold as cloud cover lingers across the region. Expect the fresh snowfall over southwest Minnesota to reinforce their cold bias from the past several weeks. .LONG TERM...(Saturday night through Friday) Issued at 341 PM CDT Fri Mar 23 2018 While most of the focus of this forecast update was the impending snowfall tonight, there is one highlight in the extended period. Next chance for precip comes courtesy of advection driven lift and an inverted trough on Monday. Precipitation type looks to be an issue with this as well, with a warm nose aloft around 850mb and the layer isn`t always saturated above -10C. This will bring chances for freezing rain in addition to snow and rain. The CWA will be affected for the remainder of the extended periods by large scale troughing aloft, leading to temperatures at or below normal. Multiple southern stream impulses far to our south will cut off most of our access to moisture, leaving only scant chances for precipitation after Tuesday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 646 PM CDT Fri Mar 23 2018 Strong storm system lifting eastward will provide plenty of IFR to MVFR conditions tonight, lasting right into Saturday. Tonight, we are dealing with both lowered visibilities and ceilings in rain and snow. Even TSRA at KFSD and KSUX is a threat early this evening. Late tonight, some light freezing drizzle is a threat for KFSD lasting through early Saturday. On Saturday, MVFR ceilings will likely linger all day. The easterly fetch of winds will decrease tonight, but will remain quite strong Friday evening with frequent gusts of 25 to 35 knots. && .FSD WATCHES/WARNINGS/ADVISORIES... SD...Winter Weather Advisory until 10 AM CDT Saturday for SDZ040-056. MN...Winter Weather Advisory until 10 AM CDT Saturday for MNZ089-097- 098. Winter Storm Warning until 10 AM CDT Saturday for MNZ071-072-080- 081-090. IA...Winter Weather Advisory until 10 AM CDT Saturday for IAZ002-014. Winter Storm Warning until 10 AM CDT Saturday for IAZ003. NE...None. && $$ UPDATE...MJ SHORT TERM...Ferguson LONG TERM...Ferguson AVIATION...MJ
Area Forecast Discussion
National Weather Service Green Bay WI
1027 PM CDT Fri Mar 23 2018 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Saturday Issued at 248 PM CDT Fri Mar 23 2018 The latest RAP analysis and satellite/radar imagery show high pressure stretching from Hudson Bay, across the western Great Lakes, and to the Gulf Coast early this afternoon. Dry air emanating out of the high is supporting falling humidities into the 20 to 25 pct range over central and north-central WI. Meanwhile, warm advection is occurring over the central to the northern Plains, which is generating an arcing band of rain and snow from North Dakota to Missouri. As this storm system slides southwest of the region tonight, temperatures and humidities are the main forecast concerns. Tonight...Precipitation will continue to shift southeast across Minnesota, Iowa, and Illinois. Slight cold advection will be occurring further north across Wisconsin, with a tight pressure gradient generating breezy northeast to east winds. Will have some cirrus invade the region from the west on the edge of the storm system, but think far NE WI will remain mostly clear through much of the night. The combo of cirrus and breezy winds off the Lake should lead to a warmer night at most locations. Low temps ranging from the low to mid teens over Vilas county to the middle or upper 20s over the southern Valley and Lakeshore. Saturday...The Hudson Bay high will continue to be dominant across northern Wisconsin. A blanket of cirrus will persist over central and east-central WI, on the northern fringes of the slow moving storm system. Under filtered sunshine, gusty east winds will make temperatures in the middle 30s to near 40 feel colder. Humidities are forecast to not fall as far as they did today, and bottom out in the 27-37 pct range over central to far northeast WI. .LONG TERM...Saturday Night Through Friday Issued at 248 PM CDT Fri Mar 23 2018 Mean flow to remain amplified, but slowly progressive next week. The main features to consist of: an eastern Pacific upper ridge, an eastward moving longwave trough across the CONUS and an east- ward moving upper ridge from the eastern CONUS into the western Atlantic. The main system of interest remains from Monday afternoon through Tuesday night as a cold front slowly pushes through WI, accompanied by a couple waves of low pressure. There will be other small precipitation chances later next week as the longwave trough arrives. Temperatures are expected to go above normal early next week as the mean flow turns southwest. Temperatures should then drop closer to normal by late week as the flow turns northwest behind the trough. High pressure over Quebec will extend southwest through the Great Lakes into the Midwest Saturday night. Clear skies and diminishing winds should bring yet another cold night to the region with min temperatures around 10 above zero north-central WI, to the lower 20s across east-central WI. Quiet and seasonal conditions are expected through Sunday as the region to remain on the southwest flank of the high pressure. A slight wind shift from east- northeast to east-southeast will also help raise temperatures a bit. Under sunny skies, look for max temperatures to range from the upper 30s to around 40 degrees near Lake MI/Bay of Green Bay, mainly lower to middle 40s elsewhere although a couple sites west of the Fox Valley could reach the upper 40s. The high pressure is forecast to start losing its influence on our weather Sunday night as a southwest flow aloft takes over the central CONUS. Anticipate some increase in at least high clouds into central WI after midnight, while eastern WI remains mostly clear. The combination of these clouds and boundary layer winds at around 30 knots will prevent temperatures from falling as far as previous nights. Look for readings in the upper teens to lower 20s far north, middle to upper 20s south. Clouds will continue to thicken, overspread northeast WI on Monday as a new system organizes over the central Plains. This system is expected to tap gulf moisture and quickly transport this moisture into WI, especially by the afternoon hours. The onset of WAA, combined with pieces of shortwave energy moving through the southwest flow aloft, will bring a chance of light rain to parts of northeast WI primarily in the afternoon. Max temperatures to range from the lower to middle 40s north/near Lake MI, middle to upper 40s south. Precipitation will become more widespread Monday night as a cold front pushes across the Upper MS Valley toward far western WI by 12z Tuesday. Plenty of moisture to be in place over WI with PW values surpassing 1" over central/east-central WI. Not sure if we have enough instability to justify carrying a thunder threat, but will leave it in the forecast for now to avoid any yo-yo effect. Precipitation type is also an issue as temperatures cool overnight. Northern WI should see rain become mixed with snow after midnight with the far north changing to all snow toward daybreak. Any snow or mixed precipitation is expected to transition back to rain Tuesday morning as temperatures warm. The cold front is forecast to steadily move across the rest of WI on Tuesday, thus higher end pops will continue over most of the forecast area. As for thunder, there is better instability with a little CAPE/LI`s approaching zero over east-central WI. Max temperatures to range from the middle to upper 40s north/lakeside, lower to middle 50s east-central WI. Precipitation chances will continue into Tuesday evening over all of northeast WI, then focuses more over eastern WI Tuesday night. Precipitation type may be an issue once again depending on how quick the precipitation diminishes and how fast cooler air pushes into WI. Any lingering clouds in the east Wednesday morning should quickly exit as a weak area of high pressure moves into the western Great Lakes. Anticipate mostly sunny skies for most of the day with max temperatures in the middle to upper 40s north/near Lake MI, upper 40s to lower 50s south. Another cold front is progged to push into the region Wednesday night, however gulf moisture appears to be lacking due to a stalled frontal boundary over the Gulf Coast states. Cannot completely rule out a few rain and/or snow showers across northeast WI later Wednesday night into Thursday. Models are having timing issues with regards to a northern stream shortwave trough Thursday night (ECMWF) or Friday (GFS). There is a pretty good surge of CAA, along with mid-level forcing, but moisture is again lacking. For now, have followed the model consensus which brings a small chance of rain/snow showers to north-central WI on Thursday, followed by a low-end chance pop for the entire forecast area Thursday night. Max temperatures for late next week to be near seasonal normals for late March. && .AVIATION...for 06Z TAF Issuance Issued at 1026 PM CDT Fri Mar 23 2018 The main aviation concern will be northeast winds, which will be gusty at times, especially in east-central Wisconsin. Given the very dry air at low-levels, will continue to downplay the potential for any low clouds tomorrow morning. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......AK AVIATION.......Skowronski
National Weather Service Jackson KY
1121 PM EDT Fri Mar 23 2018 .UPDATE... Issued at 1115 PM EDT FRI MAR 23 2018 Not many adjustments have been made so far as recent guidance does not support much in the way of change to the wintry precipitation event upcoming other than the slow down the increase in pops prior to 9Z. Temperatures in the higher terrain at Pike Co. Mesonet and Harlan County Mesonet were running colder than the previous forecast as were some of the eastern valleys where mid level clouds have yet to thicken up. Hourly temperatures and dewpoints were updated over the next few hours accordingly. UPDATE Issued at 850 PM EDT FRI MAR 23 2018 Hourly grids have been adjusted based on recent observations and trends for tonight. Clouds are gradually thickening and lowering from southwest to northeast. With some lower clouds having moved into parts of south central and middle TN. Some light rain has been reported as close as KGLW. A few of the eastern valley locations have experienced few if any mid level clouds so far and have dropped off to around the 40 degree mark. Taking a look at the upcoming event, not much in the way of changes appear to be needed at this time. Looking at 18Z and recent convective allowing models and making some slight adjustments to hourly temperatures storm totals generally remained very similar. Using smaller one hour time steps for snow to liquid ratios and these hourly temperatures which are a tad cooler int he north leads to a little less snow for upper end amounts in northern Fleming, Rowan, and Elliott counties. For locations from Estill to Letcher, this results in about half of an inch more snow for Saturday morning. At this time, no changes are planned for headlines, but each hourly run of HRRR will be evaluated for any any need for changes. A refreshed WSW product and SPS will be issued over the next couple of hours. && .SHORT TERM...(This evening through Saturday night) Issued at 444 PM EDT FRI MAR 23 2018 Extremely complex forecast as low pressure moves out of the central plains and into the lower OH valley by Saturday evening. Precipitation type is an extreme challenge as model soundings in the north show some deep near freezing isothermal profiles, which may hold through much of the day on Saturday. If such soundings verify that could mean a very heavy wet clinging snow where even 3 or 4 inches may result in power outage problems. However, it also means that just a degree temperature difference can result in a very cold rain. With the trends of recent model runs, WPC guidance and collaboration with neighboring office have opted to go with a winter storm warning for our northern counties. Three to 5 inches of snow is forecast for the warning area, but a few isolated 6 or 7 inch amounts cannot be ruled out. South and east of the warning we continued the advisory, and also added a couple of counties to the advisory. There will be close to a 20 degree temperature spread from north to the southwest part of the area on Saturday. And further south some thunderstorms will be possible, mainly in the Cumberland basin. Latest indications are that rainfall will be spread out over a long enough time period that small stream flooding should not be an issue. WPC also has not placed any of the area in the excessive rainfall outlook. With that in mind have opted to not go with a flood watch, which we had been considering earlier today. However, a few points on the Cumberland river could reach flood stage sometime on Sunday. .LONG TERM...(Sunday through Friday) Issued at 111 PM EDT FRI MAR 23 2018 The long term portion of the forecast will feature a deepening upper level trough over the western U.S. early next week, with deep southwest flow becoming established across the OH and TN valleys. By the end of the week the trough will shift east, but with southwest flow across the eastern U.S. continuing. There is good model agreement with the overall upper air pattern though some differences are to be expected with individual short waves ejecting from the upper low that will be over the southwestern part of the United States through the first half of next week. With good model agreement with the overall pattern, the concern for the coming week will be the potential for heavy rain somewhere in the central to eastern U.S. with deep southwest flow becoming established. Current indications are that the heaviest rains will likely affect areas to our west early to mid week as a slow moving front moves into the MS Valley. The front will eventually move across our area during the second half of the week, but it is possible it will stall again at some point near us or just to our east. The greatest threat for heavy rains next week appears to be over western KY and TN. While this is outside our forecast area it is close enough that the coming week will need to be monitored closely. Considering the heaviest rain potential is still 5 days away or so, it is likely the forecast axis of heaviest rains will shift during the coming days. The southwest flow will also result in warming temperatures, with above normal temperatures expected from Tuesday through at least Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) ISSUED AT 835 PM EDT FRI MAR 23 2018 VFR conditions will prevail for the first 6 to 9 hours of the period, before deterioration to MVFR and then IFR for most locations after 14Z. The IFR should then persist through the end of the period as the lower levels saturate leading to low ceilings with falling precipitation. Low pressure will move from the central plains to the lower OH valley by Saturday evening. Clouds will thicken and lower tonight with low level clouds moving into the southwest part of the area during the next few hours and advancing northeast ahead of the approaching system. Precipitation should overspread the area between about 6Z and 13Z. Enough cold air will remain in place over the northern part of the forecast area that much of the precipitation will fall as snow or a rain and snow mix Saturday morning for JKL, SYM, and SJS. Further southwest just plain rain is expected. Some thunder will be possible generally after 17Z, mainly at SME and LOZ. && .JKL WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 2 AM EDT Sunday for KYZ044-050>052- 060-104-106. Winter Weather Advisory until 2 AM EDT Sunday for KYZ059-107>110- 119-120. && $$ UPDATE...JP SHORT TERM...SBH LONG TERM...SBH AVIATION...JP
Area Forecast Discussion...UPDATED
National Weather Service North Platte NE
630 PM CDT Fri Mar 23 2018 .SYNOPSIS... Issued at 339 PM CDT Fri Mar 23 2018 A high amplitude pattern continues across the CONUS today as a ridge of high pressure extended from west Texas north into western Saskatchewan. East of this feature, a trough of low pressure extended from eastern Canada south to the outer banks of North Carolina. West of the ridge, a closed low was present off the coast of British Columbia with a trough extending south into the eastern Pacific. Downstream of this feature, upper level disturbances were present from northern Arizona into eastern Montana. The leading edge of this energy had moved into western Colorado as of midday with lightning strikes south of Grand Junction CO to Cortez CO. At the surface, low pressure was present over east central Colorado with a warm front extending east along the border of Kansas and Nebraska. South of the front, temperatures had warmed into the 60s and 70s this afternoon, while north of the front, winds were easterly and temps were in the 50s to lower 60s. && .SHORT TERM...(This evening through Saturday) Issued at 339 PM CDT Fri Mar 23 2018 The primary forecast challenge through Saturday revolves around a lee side surface low crossing the central Plains in conjunction with a stout mid-level shortwave. Thunderstorms are possible this evening, and then a notable cooldown is in store for Saturday. This evening and tonight... The surface low pressure treks across Kansas, reaching TOP by 06z, while the shortwave brushes northern Neb. The triple point rides along the NE/KS border, which will be the focus for potential severe storms. SPC RAP mesoanalysis suggests the highest deep layer shear (up to 60kts) and modest instability (up to 1000j/kg MUCAPE, 8C/km lapse rates) in the area as of 20z. Primary threat will be hail given the elevated/cool sector nature of the storms, but wind gusts can`t be ruled out if some of the stronger flow aloft is transferred toward the surface. Showers or general thunder coverage will extend into the Sandhills, where moisture and speed convergence are helping precip develop early this afternoon. Higher res model suites (RAP, HRRR, HREF) in general agreement with the greatest coverage early evening, then dissipating or being relegated to north central Neb by 06z. All precip should be out of the area by morning when min temps are achieved (upper 20s to mid 30s), negating the snow threat. However, stratus will stick around northern Neb into the morning as strong CAA takes over and trapping moisture in the lower levels. H85 temps drop toward 0C by 12z in northerly flow. Saturday... Dropped high temps a few degrees, especially across north central Nebraska where northerly low level winds will be strongest, thick cloud cover remains, and CAA continues into the afternoon. Despite cool temps aloft, overall isentropic downglide and drier air in the mid levels will limit precip chances. Farther west toward the panhandle, return flow resumes in the afternoon and H85 temps push 10C under mostly clear skies. Forecast highs range from near 40F at ONL to near 60F at IML. .LONG TERM...(Saturday night through Friday) Issued at 339 PM CDT Fri Mar 23 2018 mid range...Saturday night through Monday...Low amplitude ridging aloft will shift east of the forecast area Saturday evening. H5 flow will transition to southwesterly, allowing a lee side surface trough of low pressure to deepen along the front ranges of Colorado and Wyoming. Southerly winds will increase overnight and surface low pressure will begin to develop over eastern Colorado Sunday morning. A warm front will extend east of the surface low, with an inverted trough of low pressure extending north of the low across the Nebraska Panhandle. East of the trough and north of the warm front, cool easterly winds are expected and temperatures will struggle to get out of the 40s Sunday. We may see some lower to middle 50s in the eastern Panhandle INVOF of the inverted trough. Precipitation chances will increase Sunday night as a lead disturbance lifts from northeastern Colorado into northwestern Nebraska. As for Ptype Sunday night, decided to keep most of the pcpn as all rain based on the latest GFS soln. Will need to continue to monitor this however as a downward shift of a few degrees, could result in accumulating snows in the northwestern cwa Sunday night. long term...Monday through Friday...Another shot of rain or snow will track across the region Monday night in response to a northern stream trough, which will track across the northern plains. Mainly dry conditions are expected through the end of the work week, however, temperatures will be below normal as a second cold front tracks into the northern plains Wednesday night into Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 629 PM CDT Fri Mar 23 2018 Periods of light rain, heavier showers and isolated thunderstorms are expected to exit wrn Nebraska around 05z this evening and ncntl Nebraska around 12z Saturday. MVFR/IFR cigs are expected to backfill ncntl Nebraska as the rain exits. MVFR cigs will likely last through the afternoon along and east of highway 183 with VFR west of highway 183. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Buttler SHORT TERM...Snively LONG TERM...Buttler AVIATION...CDC
Area Forecast Discussion
National Weather Service Marquette MI
619 PM EDT Fri Mar 23 2018 .SHORT TERM...(This evening through Saturday) Issued at 413 PM EDT FRI MAR 23 2018 Water vapor imagery and RAP analysis show a ridge extending from the Plains to central Canada and a trof over eastern N America. Result is another day of nw flow over the Upper Great Lakes. Under a dry air mass, it`s been another sunny day. However, there have been some clouds off Lake Superior into a small part of n central Upper MI as an area of shallow moisture and slightly colder air (a couple of C drop at the inversion base) moved across the lake. Temps currently range from the mid/upper 20s near Lake Superior to the mid/upper 30s toward the MI/WI state line. With loss of daytime heating, may see stratocu off the lake expand a bit this evening into n central/nw Upper MI and perhaps spread well inland under low-level ne to e winds. Could be bkn cloud cover locally for a time. Overnight, winds veer more easterly which would shift any lake stratocu to just mainly the Keweenaw. Otherwise, some high clouds will gradually spread e into mainly western and s central Upper MI. Cloud cover shouldn`t have a big impact on min temps. Favored the lwr end of guidance since that has worked well in recent days. Expect mins down into the single digits in the interior, ranging up into the teens along the Great Lakes. Another quiet day is on tap for Sat. There may be some morning stratocu over the Keweenaw and perhaps also in Menominee county under easterly flow. Otherwise, sun will be filtered by some high clouds, especially w and s. Max temps will be similar to today, ranging from around 30F near Lake Superior to near 40F toward the MI/WI state line. There will be a cool ene wind. .LONG TERM...(Saturday night through Friday) Issued at 425 PM EDT FRI MAR 23 2018 The benign weather pattern that has been prevailing starts breaking down toward the tail end of the weekend. Initially closed low over the western through central Plains early next week becomes an open wave as it approaches the U.P. Moisture out ahead of the approaching system will pool into the region, allowing for precip chances to be on the increase Monday into Tuesday. While snow looks probable at the onset in the western U.P, precip type will transition over to rain during the day Monday as temps rise well above the freezing mark. As the temps drop back off toward freezing Monday night into early Tuesday, a wintry mix looks more likely, with snow prevailing over Lake Superior. Precip chances should clear out of the area late Tuesday, although could remain a bit unsettled overall through the end of the week. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 619 PM EDT FRI MAR 23 2018 VFR conditions are expected at KIWD/KCMX/KSAW thru this fcst period. Some lake effect clouds are possible off Lake Superior at KSAW this evening and at KCMX tonight into Sat morning. However, there is uncertainty in coverage and location of cloud development, so only sct clouds with bases around 2000ft were mentioned. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 413 PM EDT FRI MAR 23 2018 Strong high pres over southern Hudson Bay will shift e, reaching Quebec Sat and Sun. As this occurs, expect generally ne to e winds of 15-25kt across Lake Superior tonight/Sat, except up to 30kt over the far western part of the lake. Winds will then veer more e to se on Sun with the stronger winds shifting to the eastern part of the lake. Ahead of an approaching low pres trof, winds may reach up to 30kt at times over eastern Lake Superior Mon/Tue. Winds will be lighter over the western part of the lake. Behind the trof, winds should be under 20kt on Wed. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...Rolfson LONG TERM...lg AVIATION...07 MARINE...Rolfson
Area Forecast Discussion
National Weather Service San Francisco Bay Area
855 PM PDT Fri Mar 23 2018 .SYNOPSIS...A cold front will spread rain from north to south across much of the region tonight and Saturday morning. Additional shower activity is forecast Saturday late afternoon and evening with isolated showers possibly lingering into Sunday. Dry weather is expected to return on Monday and continue through next week. A warming trend is forecast for the first half of the week. && .DISCUSSION...As of 8:55 PM PDT Friday...Satellite, radar, and observations indicate that the cold front approaching from the northwest is currently near Point Arena. Based on the latest HRRR model, expect the cold front to spread rain across the North Bay between about 10 pm and 2 am, then south across the rest of the SF Bay Area between 2 am and 5 am Saturday, and finally through the Monterey Bay Area between 5 am and 8 am. Several lightning strikes have been detected along the northern California coast north of Point Arena this evening, so a slight chance of thunderstorms have been added to the North Bay for later this evening. All of the models indicate little or no precipitation following the front on Saturday until the cold upper low approaches late in the day. Thus, most of Saturday may end up being dry under partly cloudy skies. The evening forecast update included a reduction in shower chances for most of Saturday. Shower chances will increase late Saturday afternoon and evening as the cold upper trough approaches the northern California coast. Based on the 00Z models, shower chances will spread into our forecast area from late Saturday afternoon into Saturday night. But rainfall then is not expected to be as widespread as with the cold front moving through tonight. There is also a slight chance of thunderstorms late Saturday afternoon and early evening, mainly across the North Bay where instability will be greatest. Isolated showers may linger into Sunday, mainly near the coast in the morning, and then along the eastern portion of our forecast area in the afternoon. But for the most part Sunday is expected to be a dry and cool day. This incoming system will not have a whole lot of moisture to work with and so rain totals from tonight through the weekend are forecast to generally be a half inch or less, with highest amounts in the North Bay. Some southern inland areas may see little, if any, rainfall. Snow levels will start off around 3500 feet tonight, but then drop as low as 2500 feet by Saturday and Saturday night. Since the bulk of the precipitation is expected to fall with the cold front tonight and prior to the arrival of the coldest air, only light snowfall accumulation is expected on the higher peaks. Models continue to indicate dry weather through next week, along with a warming trend, as a ridge of high pressure develops offshore and then slowly moves eastward. && .AVIATION...As of 04:39 PM PDT Friday...for 00Z TAFs. Currently VFR conditions at all sites with scattered clouds and occasional showers in the North Bay. A cold front is still expected to move through late tonight bringing another round of steady showers. As the front approaches expect cigs to begin to lower back to MVFR. Shower chances will end early tomorrow morning once the front has passed and VFR conditions should once again prevail. Westerly winds will remain breezy through the evening at around 15 kt before taking a more southerly turn and somewhat decreasing. Vicinity of KSFO...VFR anticipated through about 03z or so, with FEW/SCT clouds between 3,000 to 5,000 ft AGL. Cigs expected to lower to MVFR this evening, ahead of a cold front that is forecast to pass through the terminal around 08-11z tonight. Models still suggest a narrow band of rain as the cold front sweeps through. Left a few hours of light rain in the tafs. Breezy southwesterly winds expected to continue into tonight. SFO Bridge Approach...Similar to KSFO. Monterey Bay Terminals...VFR conditions through tonight. Cigs will lower after midnight tonight, ahead of an approaching cold front forecast to pass through early Saturday morning. Expect wet runways from light rain as the front passes. Breezy westerly winds will continue into the evening. && .MARINE...As of 8:16 PM PDT Friday...Lightning strikes have been observed off the Northern California coast near Fort Bragg. There`s a slight chances of thunderstorms across the northern waters over the next few hours. Light to moderate west to southwest winds will prevail as a cold front makes its way through the coastal waters late tonight. Light rain is possible along the front, and winds will turn northwesterly in its wake. A second cold front is expected Saturday evening into Sunday morning. Northwest swell will increase slightly overnight tonight. && .MTR WATCHES/WARNINGS/ADVISORIES... .Tngt...SCA...Pt Arena to Pt Reyes 0-10 nm SCA...Pt Arena to Pigeon Pt 10-60 nm SCA...SF Bay from 9 PM until 3 AM SCA...Pt Reyes to Pigeon Pt 0-10 nm from 9 PM until 3 AM && $$ PUBLIC FORECAST: Dykema AVIATION: AS MARINE: AS Visit us at Follow us on Facebook, Twitter, and YouTube at:
Area Forecast Discussion
National Weather Service Pueblo CO
619 PM MDT Fri Mar 23 2018 .UPDATE... Issued at 616 PM MDT Fri Mar 23 2018 Winter weather, high wind and fire weather highlights all allowed to expire for this evening. Conditions are no longer meeting criteria. Regardless, fire danger remains high. Caution should continue. && .SHORT TERM...(This evening through Saturday) Issued at 348 PM MDT Fri Mar 23 2018 ...High Fire Danger returns to the I-25 corridor Saturday though with slightly less wind... Wind speeds appear to have peaked earlier this afternoon, as weak line of convection under the upper trough moved off the mountains and helped push gusts over 50 kts along much of the I-25 corridor, with even a few 60 kt plus gusts near Colorado Springs and Walsenburg. Surface obs and latest HRRR suggest winds are finally beginning to lessen as of 21z, though will still keep the high wind highlight in place into early evening, as gusts are still near 50 kts in places, and some weak convection still lurks west of Trinidad, which may briefly enhance gusts along the srn I-25 corridor the next few hrs. Snow over the mountains was gradually ending this afternoon, but will keep winter wx advisory up until early evening to account for howling winds and blowing snow at/above pass level. Winds diminish overnight as upper system lifts east and cold front drops south through the plains, with speeds dropping below 15 kts most locations by early Saturday morning. On Saturday, S-SE return flow develops quickly over the plains, as surface pressure begins to fall once again in the lee of the eastern mountains. Certainly won`t be as windy as today, but with gusts in the 20-30 mph range and humidity around 15 percent, upgrade of fire wx watch to a Red Flag Warning looks warranted, mainly along and just east of the I-25 corridor. Max temps will cool a few degf from Friday`s rather toasty maxes, though most locations will end up above late March averages, and some low to mid 70s will be likely over the eastern plains. .LONG TERM...(Saturday night through next Friday) Issued at 348 PM MDT Fri Mar 23 2018 Relatively active conditions are expected to continue over the forecast district during the balance of the longer term with primary initial meteorological concerns being above seasonal temperatures, gusty winds and critical fire weather conditions at times into Monday, followed by cooled/unsettled conditions developing over the majority of the CWA from Monday evening into Thursday evening. Outside of Continental Divide locations(where light precipitation will be possible at times), project that the remainder of the forecast district should experience dry conditions from Saturday evening into Monday as dry, gusty and warm southwesterly upper flow interacts with varying degrees of eastern Colorado surface lee-side troughing. Fire weather highlights will most be likely needed again Sunday and Monday due to the projected conditions. Meteorological pattern then changes from later Monday(where even some thunder is anticipated) into at least Thursday evening as two upper systems interact with moist north-northeasterly surface surges during this time-frame. As of this discussion, it appears that the highest potential for more widespread precipitation(including the potential for some accumulating snow/blowing snow) over the forecast district during the longer term should be realized from Monday evening into Tuesday evening and then again on Thursday. As always, WFO Pueblo will monitor closely. Finally, warmest temperatures during the longer term are expected from Saturday evening into Monday, while coolest conditions should be realized from Tuesday into Thursday. && .AVIATION...(For the 00Z TAFS through 00Z Saturday evening) Issued at 348 PM MDT Fri Mar 23 2018 VFR conditions expected the next 24 hrs at all terminals, with any patchy blowing dust at KPUB and KALS subsiding this evening. Strong west winds, with gusts ranging from 35 to 45 kts, will continue at all terminal forecast sites until early evening, with much lighter winds overnight. On Saturday, winds will become gusty once again, with S-SE winds gusting to 25 kts at KPUB and KCOS, while S-SW gust to 20 kts at KALS. Over the mountains, -shsn should end this evening, with clearing skies and VFR conditions most locations by early Saturday morning. && .PUB WATCHES/WARNINGS/ADVISORIES... Red Flag Warning from noon to 7 PM MDT Saturday for COZ227>233. && $$ UPDATE...LW