Forecast Discussions mentioning any of "HRRR" "RAP" "RUC13" "RUC" "RR" received at GSD on 03/29/17

Area Forecast Discussion
National Weather Service Amarillo TX
631 PM CDT Tue Mar 28 2017 .AVIATION... 00Z TAF Cycle VLIFR to IFR or MVFR ceilings and visibilities can be expected at all three TAF sites through 00Z Thursday. Scattered to numerous showers and thunderstorms can be expected at all three TAF sites through 00Z Thursday. Northeast winds 10 to 20 knots will become north and increase to around 20 to 30 knots with gusts near 35 to 40 knots after 04Z to 06Z Wednesday. Schneider && .PREV DISCUSSION... /Issued 458 PM CDT Tue Mar 28 2017/ DISCUSSION... Current radar indicates showers and thunderstorms across the eastern TX/OK Panhandle, with strong to marginally severe thunderstorms possible. Collingsworth County may be an area with better potential for severe storms as there is the potential for warmer air to advect into the area. This would increase the threat for severe weather over the next couple of hours. Otherwise for short term updates see the Mesoscale Update. Storms will still be possible overnight, but for now expect that any storms that occur will not be severe as better dynamic forcing will be to the east. With the low overhead tonight and the deformation zone mainly across the OK and northern TX Panhandles, expected moderate to heavy rain to continue. Also tracking colder air across the northwestern TX/OK Panhandles. Latest model soundings are keeping things very close to the freezing line down to the surface. Air and ground temperatures will most likely bottom out near freezing or slightly below. But precipitation aloft has a good chance of falling as snow. The uncertainty lies with how much snow will accumulate and the time frame for this snowfall. There is difficulty in the forecast due to significant QPF expected and whether temperatures will linger near freezing long enough for appreciable accumulations. No Winter Weather Advisories will be issued with this package as confidence is just not high enough. Cooler and drier air will be in place on Wednesday, with highs in the upper 40s to lower 50s for the OK Panhandle, and in the 50s to lower 60s for the TX Panhandle. Temperatures will rebound on Thursday and Friday as southwest flow returns ahead of another weather system set to impact the area next weekend. Right now models are not in good enough agreement to put certainty into the risk for severe weather. However, the pattern favors the return of thunderstorms to the Panhandles starting as early as Friday night. Will iron out the details of the significance as the weekend approaches the near term. Weber MESOSCALE UPDATE... ..Severe weather somewhat possible this afternoon/evening... * Synoptic Overview: Another in a series of upper level low pressure systems is again knocking on our door. Substantial height falls have overspread the area and forcing for ascent has been and should continue to be plentiful. At the surface, very stable air has invaded the Panhandles with all convection to this point certainly of the elevated variety. * Mesoscale (Eastern Panhandles): Generally about 1000-1500 J/kg of MUCAPE have been realized through the day, helped along by fairly steep lapse rates aloft. Model indications though are that lapse rates may weaken in the ern TX Panhandle this afternoon, with no significant increase in MUCAPE expected. After having not seen much more than penny size hail this morning, it`s kind of tough to believe we`ll be able to see much more than quarters this afternoon in the line of convection that is moving east. * Mesoscale (Western Panhandles): Of a bit more interest is the area of clearing behind the main line of ongoing convection. The low level stable air mass is shallower in the far west than in the east, and sunshine could erode enough of it to allow for an increase in sfc-based convection late this afternoon (something being seen in NM already). Due to exceptional mid level cooling associated with the upr low, forecast soundings in Deaf Smith County from the HRRR and other CAMS show the possibility of around 1200 J/kg MLCAPE with T/Td of only 57/54. Any severe concern that develops out west will likely be confined to the western 2 tiers of counties from about 6-9 PM as the thermodynamic environment will not be supportive any further east. Threats from this convection will primarily be wind and hail, but again this is all quite conditional. Simpson AVIATION...18Z TAFs...Simply put, flying conditions will be quite difficult. LIFR to IFR conditions are forecast through the TAF period for all terminals, with periods of showers and thunderstorms likely through midday Wednesday. A cold front due to enter the region will switch winds at KDHT & KGUY to a northerly direction AFT 29/02Z. Wind speeds behind the front could produce winds around 20 to 30 kts with gusts up to 40 kts, with the strongest winds expected at KGUY. Bieda && .AMA Watches/Warnings/Advisories... TX...None. OK...None. && $$ 29/11
Area Forecast Discussion
National Weather Service Taunton MA
959 PM EDT Tue Mar 28 2017 .SYNOPSIS... Wet weather continues through tonight. Improving into Wednesday into Thursday as high pressure delivers cool and dry weather. Low pressure from the Ohio Valley Friday will redevelop south of New England Friday night into Saturday. This bring snow, mixed precipitation and rain Friday into early Saturday, followed by dry weather Sunday and Monday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 10 pm update... With low pres continuing to very slowly deepen, and now about 100nm E of the Delmarva, the deformation banding across much of S New England continued to contract. This will continue to have two impacts, in that it will allow the rain to end across W and NW portions of MA/CT over the next few hours, but increase rainfall rates across portsion of E MA and RI through early AM. Will taper POPs toward latest HRRR which continues to capture this progression well. Otherwise, bulk of the forecast remains on track with this update. Previous discussion... Widespread rain with a low risk of thunderstorms. If any, mainly isolated. Anomalous deep-layer moisture with precipitable waters in excess of an inch undergoing deep layer forcing ahead of a low emerging out of the Mid-Atlantic and sweeping E immediately S of New England. Watching closely attendant frontal boundaries including that of the kink across our region for focused areas of frontogenetical convergence and subsequent moderate to perhaps heavy rain, as well as any instability that creeps N as indicated by the latest SPC mesoanalysis into S New England. Latest HRRR / RAP model trends seem to be highlighting trends well enough. A blend is preferred. Continued thinking of a decent slug of rain. Amounts of 0.50 to 0.75 with the heavier amounts focused S/E. Some locations, especially along the S coast may see higher amounts where there is a greater risk for convection. Otherwise low clouds, dreary, light E flow. With the increasing moisture across the region, will see clouds lower resulting in patchy dense fog redeveloping across the region, especially over the high terrain. Visibility down to a quarter mile or less in spots. More than likely holding through midnight, a gradual W to E progression of fog erosion as winds turn NW ushering into the region cooler and drier air towards morning. Temperatures mainly holding in the 40s but dropping into the 30s via cold air advection, either via N/E winds with initial high pressure damming, or behind the departing low late with the aforementioned N/W cool, dry winds. Temperatures should remain above freezing across all of S New England, so no concerns at the moment for black ice developing on area roadways. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Wednesday and Wednesday night... Drying out and turning breezy. Departing low pressure deepens out across the Georges Bank as a 1030+ high pressure builds S out of Canada. Combination of the tight gradient and pressure rises, cold air advection proceeding with an increasing component of isallobaric flow, will see winds increase out of the NW with gusts up to 30 to 35 mph late in the day into evening, especially out across E/SE MA, given stronger winds aloft at times during efficient boundary layer mixing up to H85. Conditions clearing during the morning. A mix of sun and clouds thru the remainder of the day and clearing overnight. Given the late- March sunshine with a warm airmass aloft lingering, albeit cold air advection will be ongoing, temperatures warm up around the upper 40s to low 50s around midday. Dropping down into the 20s overnight. Dry air and breezy winds through the day, roads should dry out. && .LONG TERM /THURSDAY THROUGH TUESDAY/... */ Highlights... * Dry and seasonable Thursday * Snow and rain developing Fri and continuing into early Sat * Plowable snow likely over higher elevations * Dry and seasonable Sunday and Monday */ Discussion... Thursday... High pressure builds across New Eng which will bring sunshine and seasonable temps. It may be a bit breezy in the morning across eastern New Eng given the pressure gradient in place, but trend will be for diminishing wind during the day. 850 mb temps around -5C in the afternoon supports highs mid 40s to around 50 degrees. Thursday night through Saturday... Complex forecast evolving as potent southern stream trof approaches Fri into Sat and interacts with northern stream energy. Result will be a primary low lifting through the Ohio valley and eastern Lakes Fri with deepening secondary low expected south of New England Friday night into Sat. As is typical at this time range there are model differences in track and intensity of the low pres which will affect QPF, thermal profile and potential snow accum. There will be two periods of precip, the first assocd with the warm advection ahead of the primary low during Fri, with a second pulse Fri night into early Sat and this may be heavy at times depending on the track and intensity of low pres to the south. Expect precip to overspread SNE from west to east after midnight Thu night to daybreak Friday. With strong high pres to NE the column will be sufficiently cold for most areas to begin as snow. However, due to marginal boundary layer temps snow may mix or even change to rain at times when precip intensity is light, especially near the coastal plain. During heavier periods, the precip will likely be snow given cold temps aloft. Minor accum are possible all the way to the coastal plain but any accum during the day will be confined to colder surfaces with most roads remaining wet. Exception is across higher elevations in interior MA and northern CT where colder temps may result in some accum on roadways. The second period of precip will be Fri night into early Sat assocd with comma head from intensifying low pres to the south. There are differences in the track which will impact intensity of precip but a period of heavy precip is possible. The uncertainty is temps will be warming aloft from SW to NE so ptype is very much uncertain, especially north of the Pike. Expect mainly rain possibly mixed with sleet at times south of the Pike. To the north, expect snow changing to sleet, freezing rain and rain but this is uncertain and subtle changes in the thermal profile and timing would yield different outcomes. Several inches snow accum possible north of the Pike with best chance of warning level snow over the east slopes of the Berkshires and northern Worcester Hills. There is also a risk of some ice accretion over the higher elevations as precip transitions to rain with temps hovering around freezing. Precip should taper off Sat morning with improving conditions in the afternoon. Sunday... Showers may linger late Saturday evening into Sunday morning as the low pressure system moves offshore. With the low offshore and a high pressure area building into the region, skies will clear throughout the day. Winds will continue to diminish along the coast, with winds gusting to 20 mph throughout the day. As the high pressure moves in, northerly winds will become westerly. Temperatures will be seasonable Sunday with high temperatures in the upper 40s to low 50s across the region. Monday and Tuesday... Both days will be seasonable with temperatures ranging in the upper 40s to mid 50s. Monday will be dry as the high pressure remains overhead. Skies will be mostly sunny throughout the day with near calm winds. A low pressure approaches from the southwest Tuesday, bringing widespread precipitation to the area. Precip will move into the area after midnight, moving from west to east across Southern New England. Rain accumulations around a quarter inch are expected, with locally high amounts of a half inch. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/... 00z update... Tonight..High confidence. Hold with IFR/LIFR cigs with vsbys lowering MVFR-IFR in areas of fog developing. Low risk TSRA, mainly over the islands. N/E flow. Improving to VFR CT valley toward morning however rest of SNE likely to remain beneath IFR-LIFR. Wednesday into Wednesday night...High confidence. Improving conditions through morning with VFR everywhere by 18Z, lingering longest over the Cape and Islands. NNW winds. Gusts to 20-25 kt at times. KBOS TAF...Will hold with IFR through 12z Wednesday. Cigs 800 feet or less. -RA/RA moving through 20z-6z. Some variability in visibility during this time frame, though a lowering trends prior to N/E winds shifting out of the W. KBDL TAF...Will hold with IFR through roughly 9z Wednesday with cigs 800 feet or less. -RA moving in presently becoming RA late afternoon into evening, improving shortly before midnight. VSBYs variable though a downward trend overnight with N/E flow before winds become W. Outlook /Thursday through Sunday/... Thursday...High confidence. VFR. Winds diminishing. Friday-Saturday...Moderate confidence. Conditions lowering to IFR with areas of LIFR with snow and mixed rain/snow transitioning to rain south of the Pike Fri evening. Snow changing to rain and freezing rain north of the Pike Fri evening. Precip ends Sat morning with improving conditions in the afternoon. Sunday... MVFR conditions becoming VFR in E Massachusetts as showers linger in association with a low pressure area moving offshore. VFR conditions for the remainder of the area. && .MARINE... Forecaster Confidence Levels... Low - less than 30 percent. Moderate - 30 to 60 percent. High - greater than 60 percent. Short Term /through Wednesday Night/... Through Wednesday night... Rain and some visibility restrictions will impact the waters overnight as an area of low pressure passes over the S waters. Exiting E out over the Georges Bank as high pressure builds S out of Canada, NW flow increases with the potential for gusts up around 30 kts developing Wednesday evening and continuing over- night with a low risk of gales. Seas build towards 6 to 8 feet on the outer waters. Small craft advisories issued accordingly with the increasing N winds beginning Wednesday into Wednesday night. Outlook /Thursday through Sunday/... Thursday...High confidence. SCA northerly gusts 25-30 kt in the morning eastern waters diminishing in the afternoon. Friday into Saturday...Moderate confidence. Easterly winds below SCA Fri. Increasing SE winds Fri night with SCA gusts likely then shifting to NE Saturday. Vsbys reduced in rain and fog mixed with snow Friday. Sunday...Moderate confidence Low pressure area moving off the coast of New England will result in diminishing winds along the SE waters. Small Craft Advisory may be needed. && .BOX WATCHES/WARNINGS/ADVISORIES... CT...None. MA...None. RI...None. MARINE...Small Craft Advisory from 11 AM Wednesday to 8 AM EDT Thursday for ANZ231>234-251. Small Craft Advisory from 5 PM Wednesday to 8 AM EDT Thursday for ANZ230. Small Craft Advisory from 8 PM Wednesday to 8 AM EDT Thursday for ANZ235>237. Small Craft Advisory from 5 AM Wednesday to 8 AM EDT Thursday for ANZ250-254>256. && $$ SYNOPSIS...KJC/Sipprell/Correia NEAR TERM...Doody/Sipprell SHORT TERM...Sipprell LONG TERM...KJC/Correia AVIATION...KJC/Sipprell/Correia MARINE...KJC/Sipprell/Correia
Area Forecast Discussion
National Weather Service State College PA
1003 PM EDT Tue Mar 28 2017 .SYNOPSIS... An area of low pressure will move off the Mid Atlantic coast overnight. High pressure will build down out of southern Canada and bring cooler and drier weather for Wednesday and Thursday. A new storm system will approach for the end of this week with the potential for more inclement weather. && .NEAR TERM /UNTIL 8 AM WEDNESDAY MORNING/... The last of the showers are slowly drifting down over the SERN 1/3 of the CWA. HRRR shows this activity fading on schedule with drier air expected to begin filtering in for the remainder of the overnight. Lows will drop to around freezing over the north, and range to the mid 40s near the MD border. This will still average some 5-10 deg warmer than normal. && .SHORT TERM /8 AM WEDNESDAY MORNING THROUGH 6 PM WEDNESDAY/... High pressure will bring a mix of sun and clouds for Wednesday over northern areas, and a bright sunny day over southern areas. Highs in the 40s and 50s will be near to slightly above normal. It will be breezy out of the north between 10 and 20 mph. && .LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... A nearly north-south ridge of high pressure with dry air, and normal to slightly below normal 850 hPa and 925 hPa temperatures will be overhead Wednesday night, creating nearly optimal conditions to radiate strongly/cool off into the 20s to low 30s. The one factor to watch closely that could impact min temps will be the timing of thickening mid/high clouds that will be spilling over the top of the upper ridge just to our west. For Thursday...should the timing of thickening clouds occur during the morning (prior to the late March sun having much of a chance to warm the sfc) then the much cooler NAM temps (ranging from the 40s to around 50F in the south) may be in store for us, accompanied by a light southeasterly flow. 12Z GFS/EC and their respective ensembles are in good agreement with the onset timing of warm frontal rain that streaks quickly east from the Ohio Valley Thursday afternoon and evening. Evaporational/dynamic cooling of the airmass helps 925-850 mb temps dip to around or slightly below 0C across our NE counties Thursday night and Friday as the steadier light-mdtly heavy, Warm Advection rain begins there. Included mention of a rain/sleet and snow mix to the North and East of a KIPT and KSEG line (mainly across elevations AOA 1800 ft msl, where even a light coating of snow/sleet is possible by daybreak Friday). There`s a low prob for a light coating of snow on the high terrain across Sullivan County. Model consensus is also for a quasi Miller-B type of low track heading just north of the Ohio River during the day Friday, then a pressure jump and slight intensification of the sfc low (to 996 mb) off the southern NJ and New England Coast Saturday. Under normally colder winter-time circumstances, this low track would be pretty favorable for a significant snowfall across much of central and northern PA. However, a quite warm boundary layer (and 850 mb temps) to begin with, coupled with the lack of a stronger anchoring high over southeast Canada and New England will mean a widespread/soaking rain evening with 24-36 hour rainfall at the majority of places here in Central PA coming in between 0.75-1.00 inch. This rainfall will add a healthy spike to the flow and levels on smaller streams and creeks across the region with broader mdt rises on rivers, but no significant threat for flooding as headwater flash flood guidance is averaging 2-2.5 inches for a 12 and 24 hour period respectively. Periods of light rain, drizzle, and ridge shrouding dense fog will persist Friday night into Saturday as slightly colder air wraps around behind the storm. Some breaks in the cloud cover should occur Saturday afternoon, esp across the Lower Susq Valley where drying downslope flow will be enhanced. Forecast temps Friday may be a bit warm considering the aforementioned storm track just to our south, and amount of rain expected. Max temps Saturday will near to a few deg F above normal in many locations. High pressure building over the region (coupled with the offsetting effect of abundant sunshine and GEFS mean 850 mb temps cooling by 3-4 deg C imply max temps close to what we`ll see Saturday, which is upper 40s to lower 50s across the nrn mtns...and mid to upper 50s elsewhere. Dry and slightly milder conditions are in the forecast for Monday as the ridge of high pressure slides just to our east and ens mean 850 mb temps rebound by a few to svrl deg C (atop a light serly sfc flow). The next, rather potent and moisture laden southern stream wave heads our way for Mon night and Tuesday, bringing a likelihood of a widespread rain. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... The last of the showers are slowly drifting down over the SERN 1/3 of the CWA. HRRR shows this activity being gone by 03Z/11PM with drier air expected to begin filtering in for the remainder of the overnight. But considerable areas of MVFR and IFR will persist over western and northern mountains into the overnight (esp at BFD/JST), while central mountains gradually improves from MVFR to VFR overnight, and downslope flow brings the SE to VFR late this evening. Any lingering restrictions over the N/W will improve by mid/late morning, with widespread fair weather and VFR conditions tomorrow as high pressure builds in. NW winds will pick up to 10-20 mph during the day however. Outlook... Wed...early A.M. restrictions; becoming VFR. Thu...VFR/No sig wx. Thu Night-Fri...Sub-VFR restrictions/rain likely. Sat...Gradually improving conditions. Sun...VFR/No sig wx. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...La Corte NEAR TERM...Grumm/La Corte SHORT TERM...Grumm LONG TERM...Lambert/Gartner AVIATION...Grumm/RXR
Area Forecast Discussion
National Weather Service Green Bay WI
1040 PM CDT Tue Mar 28 2017 Updated aviation portion for 06Z TAF issuance .SHORT TERM...Tonight and Wednesday Issued at 255 PM CDT Tue Mar 28 2017 The latest RAP analysis and satellite/radar imagery show high pressure stretching from central Canada to the western Great Lakes early this afternoon. Skies are mostly clear across the region, except near the Lake and Bay where low stratus has remained solid so far today. But over the past hour, the stratus has been starting to break up over the Door Peninsula. This trend should continue for the rest of the afternoon with further day time heating. Looking to the west, clouds are spreading northeast over the northern Plains and into the northern Mississippi Valley. Forecast concerns include cloud trends, and potential for fog tonight. Tonight...Canadian high pressure will continue to build southward into the region. Despite the loss of heating, think the low stratus deck will continue to erode over Lake Michigan, but not quickly enough to prevent a mostly cloudy start to the evening along the lakeshore. Some concern that this cloud mass could surge southwest and lower late tonight into the Fox Valley and Lakeshore, but confidence is low for that occurring, so will show clearing skies overnight. Otherwise, will see mid and high clouds invade the region from the west late. With clear skies and light winds, some ground fog could also reform over north-central WI and eastern WI late. Lows ranging from the mid 20s in the north to the low 30s near the Lake. Wednesday...Clouds will continue to thicken and lower through the day as low pressure moves across the central Plains. Light precip will try to move to central WI by late in the afternoon, but think the east winds out of the Canadian high will hold it off. Temps will continue to be cooler over eastern WI due to the clouds/east wind combo. Highs ranging from near 40 near the Lake to the upper 40s over central WI. .LONG TERM...Wednesday Night Through Tuesday Issued at 255 PM CDT Tue Mar 28 2017 Main concern for this period will be the system moving across the region Wednesday night and Thursday, and then another system early next week. The system for Wednesday night and Thursday is a little more potent on the ECMWF compared to yesterday. This could lead to a few inches of snow late Wednesday night into Thursday morning across the southern two-thirds of the forecast area. Highest snow and precipitation totals will be south of a Marinette to Wausau line. Per coordination with NWS Milwaukee, bumped up snow totals across our southern tier of counties. If latest ECMWF is correct, snow totals may need to be bumped up a little more over the next day. The snow could make for some hazardous travel for the Thursday morning commute to work or school. Any lingering rain should exit east-central and northeast Wisconsin Thursday evening. High pressure will dominate the weather pattern on Friday and Friday night. A weak cold front could bring a chance of rain/snow showers Saturday afternoon and Saturday night across the north. System passing to the south could bring a chance of precipitation Sunday night into Monday, but the next round of significant precipitation will be Monday night into Tuesday. Temperatures will be close to normal through Friday, with slightly above normal temperatures for the weekend. && .AVIATION...for 06Z TAF Issuance Issued at 1040 PM CDT Tue Mar 28 2017 Low clouds and fog over Lake Michigan should move west over the land area and bay tonight. These clouds should make it to MTW, OCQ, SUE, MNM and GRB by late tonight. Might also get to ATW and OSH. Think the areas to the west will just have increasing high clouds with maybe local ground fog. Whatever low clouds and fog there are later tonight should dissipate from west to east by midday Wednesday. A winter storm moving across the Midwest could bring a mixture of snow and rain roughly south of a AUW to GRB line late Wednesday night through Thursday night. && .GRB WATCHES/WARNINGS/ADVISORIES... NONE. && $$ SHORT TERM.....MPC LONG TERM......Eckberg AVIATION.......RDM
Area Forecast Discussion...UPDATED
National Weather Service Gray ME
914 PM EDT Tue Mar 28 2017 .SYNOPSIS... Low pressure will pass to our south tonight. Behind this system, a northwesterly flow will introduce cooler and drier air into the region for the second half of the work week. High pressure will build into the region for Thursday. Low pressure will approach the region for late Friday into Saturday with snow and mixed precipitation likely for the region. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... 01Z Update... Latest mesoscale guidance continues to show showers hugging the coast with less orographic activity and little precipitation inland except over southern NH. Will keep this trend going in the forecast with PoPs closely resembling HRRR and RAP qualitatively/in shape if not quantitatively. Have tapered PoPs as one moves inland. Dense fog was added everywhere and this is more of an issue currently north of the precipitation shield as can be expected with mixing. Expect areas of dense fog to bloom across the south as well once rain clears out. An advisory may be needed but have not decided on one quite yet. Otherwise rain showers will diminish to drizzle overnight with very low ceilings. 21Z Update... Have adjusted PoPs and QPF and corresponding snow amounts based on the latest few runs of the HRRR which has a good handle on the convection. One area of lift associated with a short wave and a warm front was producing showers over southern sections of NH and Maine. Elsewhere upslope snow showers were affecting the mountains and foothills. Precipitation chances were adjusted so categorical PoPs were not broad-brushed and instead focused on these two areas. A few other minor changes were made but nothing to change the forecast wholesale. Previous discussion... A weak shortwave impulse on GOES water vapor imagery was crossing the mid Atlantic region with a 1009 millibar surface reflection over the DELMARVA region and a weak surface boundary extending northward into western New England. Widespread low clouds remained across the region at moment. NWS Doppler radar mosaic showed an expanding area of precipitation across the mid Atlantic to southwestern New England that will cross southern New Hampshire and adjacent southwest coastal Maine during the late afternoon and early evening hours. Elsewhere...only scattered precipitation is likely as a cold front over Quebec drops southward across the region overnight. The activity should taper quickly after midnight as the surface low and shortwave impulse race offshore. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... On Wednesday...a freshening northerly breeze in the wake of the departing coastal low with a few clouds and upslope snow or rain showers across the higher terrain. Highs will range from near 40 in the mountains to near 50 over southeast New Hampshire. Some lingering upslope clouds and snow showers Wednesday night in the mountains...otherwise mostly clear elsewhere with a diminishing northerly breeze and the surface high begins building into eastern New England. Lows will range from the mid 20s to around 30. && .LONG TERM /THURSDAY THROUGH TUESDAY/... Confidence is gradually increasing for a fairly significant late season snow and/or mixed precipitation event starting Friday and lasting into Saturday. 12z deterministic guidance is in general agreement today on track of short wave troughs and attendant SFC low pressure along with subsequent heavy snowfall for at least the southern half of the CWA. The ECMWF ensemble probabilities for 6 or more inches of snow have steadily increased over the last 24 hours, now offering a 50-70 percent chance of 6"+ to a fairly good chunk of the CWA. However, with that said, we are still at least 3 days out and even tight ensemble consensus can still go awry at this time range. There are also questions about boundary layer temperatures and perhaps even some warm mid level temps creeping into southernmost zones. The track of the overall system could still push further south also. These issues can certainly be the cause of a lighter snowfall. So being a bit conservative in the forecast temperature/qpf/snow grids is prudent at this time. However, we did lower SFC temps Friday afternoon and night as most raw model guidance slams SFC temps down to 31-33 degrees as strong UVVs move into the area and allow for cooling via lift, evaporation, and melting. At this time I would expect at least interior southern zones to pick up a plowable snowfall starting Friday afternoon or evening and ending Saturday. However, there is low confidence at this time for a lot more over a wide area, although possible. Bears watch for sure. A heavier snowfall this time of year would probably cause power outage issues. && .AVIATION /01Z WEDNESDAY THROUGH SUNDAY/... Short Term...IFR to LIFR conditions persist for all TAF sites through the overnight hours in low stratus and areas of dense well as -SHRA and -DZ along the coast as well as HIE, CON, and MHT. Look for improvement to VFR during Wednesday morning for most terminals although moisture trapped under an inversion may make improvement slow going for mountain terminals. NW winds will eventually gust to btw 20 and 25 kt in the afternoon. Sct MVFR conditions will be psb in mtns once again in -SHRA/-SHSN. Long Term...IFR conditions possible in snow and mixed precipitation starting Friday and lasting into Saturday. Conditions likely improve Saturday night and Sunday. && .MARINE... Short Term...Winds and seas will remain below small craft through Wednesday afternoon. Conditions will reach Small Craft Advisory threshold by Wednesday evening outside the bays in strengthening northerly flow. Long Term...SCA conditions will subside Thursday. They will once again be possible over the weekend as low pressure passes to the south of the waters. && .TIDES/COASTAL FLOODING... We`re entering the period of high astronomical tides. The Wednesday and thursday night high 105 AM Thursday and 152 AM Friday respectfully are 11.1 ft MLLW (referenced to Portland Harbor with a 12.0 ft MLLW flood stage). Fortunately the flow will be offshore so no problems are anticipated with these particular tides. However, the Friday night high tide at 243 AM is an 11.0 ft MLLW. With potential for a strengthening onshore flow prior to this particular high tide cycle...we will need to monitor this time period for possible coastal flooding and beach erosion. && .GYX WATCHES/WARNINGS/ADVISORIES... ME...None. NH...None. MARINE...None. && $$ NEAR TERM...Hanes SHORT TERM...Schwibs LONG TERM...Ekster
Area Forecast Discussion
National Weather Service Wilmington NC
1045 PM EDT Tue Mar 28 2017 .SYNOPSIS... a cold front which will drop south across the area by late tonight or early Wed. Relatively cooler and drier high pressure will build in from the north Wed into Thu night. Showers and thunderstorms are expected on Fri as warmer and more humid air returns ahead of an approaching cold front. The cold front will sweep eastward across the area and offshore late Fri night. Some of the thunderstorms may become strong to severe Fri. The weekend should be dry and warm on Sat with temps dropping back to near normal on Sun as high pressure builds in from the Great Lakes. && .NEAR TERM /THROUGH WEDNESDAY/... As of 945 PM Tuesday...Sfc cold front will sink slowly across the area overnight. The convergence along this front is evident with Cu and SC strewn along it from west to east. A few of these Cu are building just enough to produce isolated showers. However, aloft, NVA ie. Subsidence, is now affecting the FA with the mid-level s/w trof having pushed off the DELMARVA Coast this evening. As a result, do not expect much vertical development with these showers. May continue the slight chance POP well into this evening as this boundary drops southward. Not much tweaking to tonights lows from the previous fcst update. However, am concerned for the possibility of fog eventhough models are not highlighting its potential. Will update to include patchy for now and could get worse with time depending how much drier air, ie. lower dewpoints, are able to advect into the FA overnight. Seen it many times after FROPA in the evening and winds go NW to N less than 5 kt. And with ground moisture avbl from rainfall having occurred earlier today and also late this aftn and evening. Previous..................................................... As of 3 PM Tuesday...A second shortwave is crossing the Carolinas this afternoon and with the early shortwave there has been a delay in additional convection developing. The GOES-16 1-minute imagery is showing cumulus developing west of Florence to Pembroke and isolated cumulus developing to the west. The 16 UTC HRRR is only showing isolated convection through sunset. So will keep a 20 to 30% chance of convection with the higher chances for the northern coastal areas. The frontal boundary will shift across the area after midnight and sweep to the south with high pressure building in the area into Wednesday. Lows tonight are expected to fall into the upper 50s and highs on Wednesday to around 80 except cooler at the beaches with a northeast flow. && .SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 3 PM Tuesday...Mid level ridge axis over the southeast will be deamplifying and shifting east Wed night as surface high over southern Canada builds down the east coast. Cooler air associated with the Canadian high spreads over the region Wed night with lows dropping close to climo. Northeast winds will be in the 5 to 8 mph range which should prevent any radiational cooling. Low will be in the low to mid 50s across much of the area. Surface high shifts off the coast later Thu with weak return flow developing Thu night. Ridging aloft Wed night and Thu will keep the region dry through at least Thu evening. Forecast soundings show impressive subsidence from 850mb through 700mb into Thu night before approaching high amplitude southern stream system shunts the 5h ridge axis farther off the coast. Developing deep southwest flow Thu night increases moisture in the region, precipitable water values increase from around 0.80" Thu evening to 1.40" by the end of the period. Arrival of this deeper moisture along with an increase in mid level lapse rates should open the door for some convection late in the period. The unfavorable timing and lack of strong low level jetting does suggest coverage will be rather limited and do not plan on much in the way of changes to inherited Thu night precip chances. Temperatures Thu will be near to slightly below climo, upper 60s to lower 70s, with temps Thu night running above to well above climo and likely following an atypical curve with slight warming after midnight. && .LONG TERM /FRIDAY THROUGH TUESDAY/... As of 300 AM Tuesday...Next in series of potent southern stream systems will impact the eastern Carolinas Fri and Fri night with a categorical risk for showers and thunderstorms developing. The combination of significant upper level support and strong and deep moisture return and lift provides at least the opportunity for a more widespread and significant rainfall event. There will be some risk for strong to severe thunderstorms during this time. 0-6 km effective bulk shear parameters are not particularly impressive. However, instability does grow with mixed layer CAPE values on the order of 500 to 1000 J/kg as the warm front should move to our N. Mid-level lapse rates are forecast to be rather modest. The potential is there for an active day/night leading into the weekend, although magnitude is certainly still a question mark. In the wake of this system, dry weather and near to above normal temps are expected for the weekend as mid-level ridging builds across the area and surface high pressure builds from the NW and N. Attention then will turn westward as next southern stream system along the Gulf Coast Sun night lifts to the NE and drags a warm front to the N. This will again bring deep moisture into the Carolinas, and with that, showers and thunderstorms early next week. Given timing differences between long range models and a general slower trend as compared to 24 hours ago, will cap POPs in the chance category until we can gain better resolution as to when the highest risk for showers and thunderstorms will occur. && .AVIATION /03Z WEDNESDAY THROUGH SUNDAY/... As of 0230Z...Updated the pre-dawn Wed hours for all 5 terminals to include 3sm to 4sm in BR. Upstream, a few sites across Eastern NC have seen their vsby drop due to fog. In fact, the 2 sites exhibiting fog, KISO and KGWW, have dropped to 1/2 mile in FG. Will refrain from including FG at this update but will monitor. Previous................................................. As of 00Z...Sfc convergent boundary lies along an east to west line extending from Surf City across Whiteville to Hartsville. This feature is a product of storm outflows and the sfc cold front sinking southward. Isolated low topped showers and possibly a thunderstorm will likely continue to develop along this boundary as it sinks southward for the next few hours. With subsidence aloft, do not expect much vertical development. Will only carry VCSH for the associated terminals near this boundary. The remainder of the night will see improving ceilings and winds that slowly veer from SW-W to NW-N overnight...and to the NE during Wed. Wind speeds mainly 5 to 10 kt early this evening, dropping to 2 to 4 kt overnight after the CFP. None of the near term guidance is illustrating fog development for the pre-dawn Wed hrs. May place patchy MVFR fog at press time or amend later on this evening if 00Z Model guidance shows it. No ceilings or pcpn for daylight Wed. Only concern will be the slow veering wind direction trend from NNW-NNE at sunrise to ENE to E at sunset. Wind speeds thruout the day at 5 to 10 kt. The coastal terminals may see an aftn/early evening seabreeze develop with winds from the SE around 10 kt. Extended outlook...VFR conditions Thu. MVFR/IFR conditions likely in showers and strong to severe thunderstorms Fri/Fri night. VFR conditions Sat thru Sun. && .MARINE... NEAR TERM /THROUGH WEDNESDAY/... As of 945 PM Tuesday...Update concerned with pcpn eventually ending late this evening. And, re-adjusting the winds based on the slowly southward dropping sfc boundary that will result in winds becoming NW to N after its passage during this evening thru the pre-dawn Wed hours. The sfc pg is rather loose on either side of the sfc cold front, resulting with only 10 to 15 kt wind speeds being fcst. Significant seas will run 2 to 4 ft with 5 footers across the outer waters off Cape Romain and Cape Fear. The healthy SE ground swell at 10 to 11 second periods has peaked during today and should now exhibit a slow decaying trend. Will see wind driven waves become more dominant in the seas spectrum later Wed as NE winds increase due to sfc ridging down the east coast from Canada becoming more prominent. Previous.................................................... As of 3 PM Tuesday...SW winds around 15 knots with higher gust are seen at coastal CMAN stations...not receiving any offshore buoy data at this minute so have lower confidence of the current wind speeds at 10 to 20 miles off the coast. With cold front approaching expect to see winds increase to 15 to 20 knots with higher gust. Seas are expected to peak at 3 to 5 feet. Will continue to see longer period swells through this evening. With the cold frontal passage expected between 2 AM and 6 AM Wednesday, seas will slowly fall to the 3 to 4 feet range by the end of Wednesday. SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/... As of 3 PM Tuesday...Northeast flow will continue Wed night and Thu as high pressure over southern Canada builds south. Gradient becomes pinched late Wed night as cold surge moves across the waters and northeast flow may briefly hit 20 kt. Northeast flow remains 15 to 20 kt Thu before starting to decrease and veer to east Thu evening and then southeast Thu night as the surface ridge axis moves offshore. Seas will range from 3 to 5 ft through Thu night with shorter wave periods expected given the strength of the northeast flow. Exercise caution headlines may be needed during the period, depending on the strength of the northeast surge late Wed night. LONG TERM /FRIDAY THROUGH SUNDAY/... As of 300 AM Tuesday...A Small Craft Advisory is likely for all waters Fri and Fri night with conditions possibly lingering into Sat. Slow moving area of low pressure will be moving across the Ohio Valley Fri. Its accompanying warm front will move across the waters Fri. As low pressure moves offshore of the Mid-Atlantic states late Fri night and Sat morning, it will strengthen and drag a cold front across the waters. High pressure will slowly build across the area from the N and NW Sat night and Sun. SE winds Fri morning will become S and then SW Fri night. The wind direction will become westerly early Sat morning and then NW by Sat afternoon. N winds Sat night will become NE overnight Sat with NE winds persisting into Sun before veering to easterly during the afternoon. The strongest winds are expected Fri and Fri night, up to 20 to 25 kt. Seas late Fri and Fri night will build to 4 to 7 ft and around 8 ft at frying Pan Shoals. Seas during Sat will only slowly subside as backswell from departing storm system impacts the waters. Seas should drop below advisory levels by late Sat and to 2 to 4 ft on Sun. && .ILM WATCHES/WARNINGS/ADVISORIES... SC...None. NC...None. MARINE...None. && $$ SYNOPSIS...DCH NEAR TERM...DCH/DRH SHORT TERM...III LONG TERM...RJD AVIATION...DCH
Area Forecast Discussion
National Weather Service North Platte NE
644 PM CDT Tue Mar 28 2017 .SHORT TERM...(This evening through Wednesday) Issued at 336 PM CDT Tue Mar 28 2017 Dry air is getting entrained into the rain system moving across Nebraska. The easterly cold conveyor has not moisten up and there is evidence from radar the moisture divergence is occurring across Swrn Neb. The rain area across Wrn KS should continue moving north this evening and get shunted east. The forecast continues to follow a blended approach which resembles the RAP model. The better rain should shift south across Swrn Neb this evening and then into Scntl Neb early Wednesday. Moisture advection weakens across Nrn Neb this evening and rain chances across northwest Neb end Wednesday morning. A developing area of rain across ern Neb Wednesday may wrap west into Ncntl Neb. If this does not happen then Wrn and Ncntl Nebraska could dry out Wednesday afternoon. The forecast for dew points uses the RAP and GFS which were more moist. Temperatures are blended deterministic data plus bias correction. There appears to be a cold bias in the guidance and the warmer temperatures tonight would likely preclude any kind of mix of rain and snow across Wrn Neb tonight. In fact, the NAM and GFS dominant model precip is all rain. The NAM 4km Nest suggests a mix and a mix is in place across the Wrn Sandhills...generally near or above 4000 feet where temperatures might fall into the mid 30s. .LONG TERM...(Wednesday night through Tuesday) Issued at 336 PM CDT Tue Mar 28 2017 Lingering light rain is possible across the far southeast part of the forecast area, from O`Neill to Broken Bow to Curtis Wednesday evening. After midnight the system will have shifted east of the area. Have backed off on pops a little Wednesday evening, as convection to the southeast of the area appears will adjust the over kinematics/location of the system, keeping the main deformation band of precipitation mainly south and east of the area. Thursday will be a dry day with upper level ridging briefly taking control ahead of the next system. GFS ensemble mean closes of this next system across southern Colorado Friday, then slowly tracks east across Kansas Saturday. This track would provide another shot of potentially beneficial rainfall for at least the southern half of Nebraska. System moves slowly northeast in a weakening state Sunday. Scattered showers will remain in the forecast Sunday as the system opens up and slowly tracks northeast across the area. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 640 PM CDT Tue Mar 28 2017 Generally IFR to MVFR conditions due to ceilings and rain can be expected through early Wednesday morning. Conditions will improve somewhat during the day Wednesday, with MVFR across southwest through central Nebraska, and some VFR for areas across north central Nebraska into the Panhandle. Light rain will remain possible through Wednesday, especially across southwest through central Nebraska. && .LBF WATCHES/WARNINGS/ADVISORIES... None. && $$ SHORT TERM...CDC LONG TERM...Taylor AVIATION...Taylor
Area Forecast Discussion...Updated Aviation
National Weather Service Saint Louis MO
1043 PM CDT Tue Mar 28 2017 .UPDATE... Issued at 913 PM CDT Tue Mar 28 2017 Latest NAM and HRRR model guidance is a little slower bringing showers into our forecast area late tonight/early Wednesday morning. It appears that showers will move into central MO around 12Z Wednesday morning, then move into northeast MO and west central IL later in the morning, mainly north and west of STL as a southerly low level jet brings increasing temperature and moisture advection into this area. Lows tonight will be slightly above normal for late March with a low level cloud cover along with gradually increasing east-northeasterly surface winds as the surface pressure gradient tightens. GKS && .SHORT TERM... (Through Late Wednesday Afternoon) Issued at 327 PM CDT Tue Mar 28 2017 Clouds have stayed locked in over the area as the clearing over east central Illinois that was working into the eastern CWA filled back in with stratocumulus this afternoon. Forecast soundings do show that the low levels will stay saturated through the night, with an increase in mid-high clouds as upper low currently over New Mexico moves northeast into the Plains. Showers and isolated thunderstorms will move into the area late tonight per the GFS and NAM as the upper ridge moves east and a band of strong moisture convergence sets up on the nose of a 40kt low level jet. This low level forcing combined with increased mid-upper ascent from approaching low will be enough to set up one round of showers and scattered thunderstorms late tonight and tomorrow morning. Then there may be a break during the late morning and early afternoon before both models show another round of showers and thunderstorms moving into central Missouri by late afternoon. Went closer to the GFS MOS temperatures over the next 24 hours. Britt .LONG TERM... (Wednesday Night through Next Tuesday) Issued at 327 PM CDT Tue Mar 28 2017 Primary concern heading into Wednesday night is the potential for severe weather. Guidance is in good agreement that there will be thunderstorms over western Missouri at 00Z moving toward our area. Forecast instability falls of pretty quickly in the evening with MUCAPE values not exceeding 500 J/Kg on the GFS until after 09Z. NAM has more energy in the evening pushing 1000 J/Kg, but it tends to be a bit too high, and even with that high bias MUCAPE values fall off overnight. Regardless...with 50-60kts of deep layer shear, can`t say there won`t be severe storms; but the threat should stay over our eastern Ozark counties where instability will be greatest. Should be a better chance for severe storms on Thursday ahead of the low. SBCAPE increases to around 2000 J/Kg during the afternoon. Deep layer shear isn`t as impressive initially at 18Z but increases to 40+ kts along and southeast of I-44 and south of I-70. 0-1KM helicity is less than 100 m2/s2 for the afternoon hours on Thursday so think the primary threats will be hail and damaging wind rather than tornadoes. Thunderstorm threat will be coming to an end Thursday night although rain will likely continue on the west side of the low as it passes for a good portion of the night. Cooler and drier air will move into the area on Friday and Saturday. Overnight lows will dip into the upper 30s and 40s with daytime highs mainly in the upper 50s to mid 60s. There is a chance there could be some rain on Sunday ahead of the next system as the upper level shortwave digs into the southern Plains. However the GFS and ECMWF disagree on how much QPF to print out so have reduced PoPs for Sunday until we see a little better agreement. The system lifts out of the Southern Plains into the Mississippi Valley on Monday so rain chances for early in the week look good. The GFS and ECMWF can`t agree on a track for the surface system just yet with the GFS being further north and therefore warmer than the EC. Think the current hedge between the two with highs mainly in the 60s and lows in the mid 40s to low 50s looks good. Carney && .AVIATION... (For the 06z TAFs through 06z Wednesday Night) Issued at 1027 PM CDT Tue Mar 28 2017 Cloud ceiling around 3000 feet should gradually lower late tonight and early Wednesday morning, eventually down to IFR by late Wednesday morning. It appears that showers will move into the COU area around 12Z Wednesday, and into UIN and possibly also the St Louis metro area as well later in the morning as a southerly low level jet brings increasing low level moisture into the area ahead of an approaching low pressure system over the southern Plains. East-northeast surface winds will strengthen late tonight and Wednesday morning as the surface pressure gradient tightens. There will likely be a break in the convection Wednesday afternoon, then another round of showers and storms will move through the taf sites Wednesday night as a warm front approaches from the south. SPECIFICS FOR KSTL: Cloud ceiling around 3000 feet should gradually lower late tonight and early Wednesday morning, eventually down to IFR by late Wednesday morning. It appears that scattered showers will move into the St Louis metro area in the morning as a southerly low level jet brings increasing low level moisture into the area ahead of an approaching low pressure system over the southern Plains. Northeast surface winds will strengthen late tonight and Wednesday as the surface pressure gradient tightens. There will likely be a break in the convection Wednesday afternoon, then another round of showers and storms will move into the STL area by late Wednesday night as a warm front approaches from the south. GKS && .PRELIMINARY POINT TEMPS/POPS... Saint Louis 47 63 56 71 / 5 60 90 80 Quincy 42 55 50 61 / 5 70 90 80 Columbia 47 60 54 67 / 40 70 90 70 Jefferson City 49 62 55 68 / 30 60 90 70 Salem 48 64 56 72 / 0 30 70 90 Farmington 50 64 58 71 / 5 50 90 80 && .LSX WATCHES/WARNINGS/ADVISORIES... MO...None. IL...None. && $$ WFO LSX
Area Forecast Discussion
National Weather Service Melbourne FL
827 PM EDT Tue Mar 28 2017 .DISCUSSION...High pressure ridge across the area will slide slowly southward into tonight. The proximity of the ridge will again make for lighter winds across the area overnight. Radar and observations show sea breeze collision about to occur from NW Osceola County northward through western Orange and eastern Lake counties. Local WRF and HRRR indicate a few brief pop-up showers from this collision, but overall rain chances look too low to mention in the forecast. If a shower or two does develop it should be very brief this evening. Lows tonight will range from the upper 50s to low 60s. Lighter winds and clear/mostly clear skies will again produce the potential for patchy shallow fog overnight. Main concern will be if any smoke from lingering brush fires mixes with fog and leads to locally reduced visibilities again on some highways late tonight into early morning Wednesday. && .AVIATION...Mainly VFR. Patchy fog producing mostly MVFR visibilities will be possible again late tonight through daybreak Wednesday. However, looks fairly limited so for now will not include in the TAFs. Locally reduced visibilities will again be possible near any wildfires. && .MARINE... Tonight-Wed...(Previous Discussion) Continued good boating conditions with light southwest-west winds due to weak high pressure ridge settling to south Florida. Lingering east swells could produce rough conditions near inlets during the outgoing tide. && .MLB WATCHES/WARNINGS/ADVISORIES... FL...None. AM...None. && $$ Weitlich/Cristaldi
Area Forecast Discussion
National Weather Service Marquette MI
751 PM EDT Tue Mar 28 2017 .SHORT TERM...(This evening through Wednesday) Issued at 304 PM EDT TUE MAR 28 2017 12Z raobs/latest wv imagery and RAP analysis show a shrtwv rdg in the nrn branch flow over scentral Canada that is supporting a sfc hi pres over nrn Manitoba expanding into Ontario. There is a weak shrtwv crossing the Upr Lks, but dryness of the mid lvls shown on local 12Z raobs is allowing for only some patchy mid/hi clds over mainly the nrn cwa. Area of fog and lo cld that was over the ern cwa this mrng with llvl mstr trapped under lo subsidence invrn base as depicted on the 12Z APX raob has dsptd as the incrsgly acyc llvl nne flow associated with the expanding sfc hi pres rdg is advecting some drier air into the area in the presence of daytime heating, which has aided in mixing out this mstr. The lo cld has been most persistent near Lk MI and over far ern Lk Sup, where the cooling influence of the waters have slowed daytime heating/mixing out of the lo cld. Away fm this area, temps have climbed into the 50s away fm the cooling influence of Lk Sup. There is quite a bit of lo cld farther n over Ontario under area of colder near sfc temps. Main fcst concerns in the short term are lo cld trends/temps. Large scale subsidence under shrtwv rdging/expanding Hudson Bay hi pres wl tend to suppress the mid/hi cld and bring dry wx. Tngt...The Hudson Bay hi pres center is fcst to build slowly to the se and be centered over far nw Ontario just to the w of James Bay by 12Z Wed. Upr MI wl be under the influence of the acyc, slowly veering llvl flow toward the ene. Even though the diffluent/acyc nature of this wind would tend to break up lo clds, concern is lo clds lingering over ern Lk Sup and spreading s thru Ontario wl redevelop over mainly the ncentral cwa as the expected ene winds upslope into that area in the presence of nocturnal cooling. Expect the lowest min temps over the interior w, where the llvl flow wl downslope and allow for moclr skies. Not out of the question temps in this area could fall as lo as the upper teens. Wed...Upr MI wl remain under the influence of Hudson Bay hi pres moving slowly to the e to over James Bay by 00Z Thu and slowly veering llvl flow to the e. Expect any lo clds in the mrng over mainly the ncentral to mix out with daytime heating. Since h85 temps wl be 2-3C cooler than tday and hi clds wl be on the incrs, expect Wed max temps to be lower than today, reaching to near 50 over the interior w with some downsloping away fm lk moderation. .LONG TERM...(Wednesday night through Tuesday) Issued at 318 PM EDT TUE MAR 28 2017 The extended looks to be fairly quiet overall with the main focus on low pressure sliding to the south of the U.P. Thursday into Thursday night and another low pressure trough sliding across the area Saturday into Saturday night. A more widespread precipitation event is possible for early next week, Monday night into Tuesday. Otherwise, expect above normal temperatures through the extended with highs in the 40s to around 50 and overnight lows in the mid to upper 20s. Thursday and Thursday night: An area of low pressure sliding across the mid Mississippi Valley is progged to lift slowly through the Ohio River Valley through this time period. At the same time, a Hudson Bay high pressure system will remain near stationary or slide very slowly off to the east. The northern fringes of the moisture associated with the low will try to work into the U.P.; however, the northward extent is expected to be limited as the flow around the high pressure system will be very dry. The easterly winds will steadily pump dry air in to offset the approaching moisture. This continues the trend seen over the past couple days. At this point, will continue pushing the pops down across the south central U.P. and east along Lake Michigan. If precipitation does occur, it will mostly likely be in the form of light snow or rain/snow mix. Most of the sounding looks to be below freezing with some ice crystals in the layer; however, the lower levels are fairly dry for Thursday afternoon into Thursday evening. Wet bulb temperatures in the dry layer would suggest cooling to or just below freezing through that time period, keeping the precip in the form of mainly light snow. The rest of the area is only expected to see an increase in cloud cover through this time period. Friday through Saturday night: Drier air and a weak ridge will slide through the area Friday into Friday night allowing for mostly clear skies across the U.P. The next chance of precipitation will be Saturday through Saturday night as a quick moving surface trough and upper-level trough slide through the area. At this point, not expecting an all day, widepsread rainfall, but at least expecting a quick moving shot at light rain. It may actually cool off enough at Saturday night for some snow to mix in, but not expecting much for accumulation. Monday night into Tuesday: A broad area of low pressure is progged to slide into the Upper Great Lakes region, bringing widespread precipitation. There has been some variance in the models for that time period, as expected with it being toward the end of the forecast period, but the latest trends have the area under an unsettled weather pattern for that time period. The Canadian is pulling back a bit; however, with little to no precipitation making into the U.P. At this point, will stick with a blend of the models, painting precipitation across the area. 850mb temperatures, as well as much of the soundings, are progged to be a few degrees above zero, which would keep the precipitation mainly in the form of rain across the area. Stay tuned as there is still plenty of variability in the models. && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 746 PM EDT TUE MAR 28 2017 Expect VFR conditions and light winds to prevail at IWD and CMX through the forecast period. However, shallow low level moisture over Lake Superior could lead to stratus/IFR conditions tonight at KSAW under light upslope ne winds. Although confidence is still limited, opted to mention a period of bkn IFR cigs and some MVFR fog late tonight into early Wednesday. Any fog and low clds will burn off by late morning. && .MARINE...(For the 4 PM Lake Superior forecast issuance) Issued at 304 PM EDT TUE MAR 28 2017 With no significant weather systems affecting the Upper Great Lakes for the rest of this week, winds will mostly be under 20kt this forecast period. The stronger winds (gusting to around 20kt) will occur tonight thru Wed night under slightly tighter pres gradient btwn Hudson Bay hi pres and lo pres tracking from the southern Plains toward the Ohio River Valley. && .MQT WATCHES/WARNINGS/ADVISORIES... Upper Michigan... None. Lake Superior... None. Lake Michigan... None. && $$ SHORT TERM...KC LONG TERM...KEC AVIATION...JLB MARINE...KC
Area Forecast Discussion
National Weather Service Pueblo CO
926 PM MDT Tue Mar 28 2017 .UPDATE... Issued at 853 PM MDT Tue Mar 28 2017 Latest HRRR and 00z NAM suggest snow/highlights generally on track, especially for the southern mountains where snow levels were falling and heavy precip will continue. Warning for Teller/nrn El Paso counties looks a little less promising, with only light precip so far this evening and models suggesting rather intermittent precip the remainder of the night. Still think there is the possibility for some low end warning accums by mid- morning Wed, with both NAM and HRRR showing a small area of heavier snow (storm total of around 8") over nrn El Paso county through mid-morning Wed, along with some 30-40 mph winds. Will keep warnings in place, though will continue to nudge amounts downward toward the low end of warning range, especially for Teller County. && .SHORT TERM...(This evening through Wednesday) Issued at 250 PM MDT Tue Mar 28 2017 Models in fairly good consensus with the upper low taking the more southern track across central NM. This is still a favorable track for southeast CO...and it still appears best forcing and isentropic upglide will affect southern portions of the southeast mountains tonight. Have shaded down snow amounts for Teller county and Pikes Peak a bit...though it still looks like a good 8 to 14 inches of snow will be possible with the heaviest falling across the northeast facing slopes. Higher elevations of Pikes Peak should fair a little better. The big winners with this event still appears to be the Sangre De Cristo and Wet mountains where a combination of dynamics and northeast upslope flow should push snowfall totals into the 1-2 foot range though local areas could see up to 3 feet from this storm. The Palmer Divide and Raton Ridge should also see some appreciable amounts of snow with amounts in the 5 to 12 inch range. Have added Eastern Las Animas county into a winter weather advisory for late tonight through Wednesday morning as latest models show a rain snow switch with a window for heavy snowfall late tonight through Wednesday morning. As for snow levels...model soundings still suggest rather high snow levels this afternoon and evening...around 8500-9000 feet...and given the convective nature to the event through this evening...with CAPE up to 400 j/kg...will still need to monitor the lower elevations of the newer burn scars until snow levels drop through this evening. By 06z...snow levels should be dropping to around 6000 feet...and by 12z...could see snow levels drop briefly to around 5500-5000 feet by morning. Still looks like an all rain event for the greater Pueblo area...though some flakes mixing in during the morning will still be a possibility. After 07z-08z...high res models show northerly flow off the Palmer Divide winning out over the dynamics aloft...with precipitation waning off during the early morning hours north of highway 50. Precipitation will hang on longer down along the Raton and eastern plains as the upper low pulls eastward through the TX Panhandle into NW OK and southern KS. Snow levels will rise again so eastern Las Animas county will probably shift back over to advisory will come down by noon. Overall QPF totals should range between .75 to 1.5 inches across the southeast mountains and plains...with some areas picking up 2.0 inches or a little more. A good precipitation event to help mitigate the recent drought conditions. -KT .LONG TERM...(Wednesday night through Tuesday) Issued at 250 PM MDT Tue Mar 28 2017 Active weather pattern continues through the extended as the next closed low drops through NV/UT Thursday night and tracks more slowly eastward across NM and southern CO through the weekend. Still some differences with the storm track with this one...but looks like another potential heavy precipitation producer for southern CO...with the current track suggesting the higher amounts may be shifted a bit northward from the current storm. Once again...heavy mountain snows and lower elevation rain will accompany this storm. GFS suggests heaviest snow for the southeast mountains in the Saturday-Saturday night period. Have shaded pops upwards into the likely category for these periods. This storm lingers a little longer than the past couple...then another system takes a more northern track across CO in the Monday night early Tuesday period. Overall the active pattern continues. -KT && .AVIATION...(For the 00Z TAFS through 00Z Wednesday evening) Issued at 516 PM MDT Tue Mar 28 2017 Overview... There is a low pressure system currently located over north central New Mexico propagating easterly as time progresses. The major weather concern is precipitation, which will affect ALS, COS, and PUB. ALS... Generally there will be northerly/northeasterly flow throughout most of the forecast period. Precipitation will start out as rain, transitioning to snow during the late evening/ overnight hours. Conditions will deteriorate to MVFR conditions overnight. Flight categories improve to VFR in the late morning hours. COS... Rain will transition to snow during the late evening/overnight hours. During the precipitation event, MVFR conditions will be experienced, improving to VFR in the late morning hours. The northerly winds become gusty during the late evening and will continue to be gusty throughout the forecast period. PUB... Rain will be observed during the evening and the overnight hours. Flight conditions will degrade to MVFR conditions until the late morning hours when the flight category becomes VFR. The northerly winds remain constant throughout, becoming gusty later this evening and remain gusty for the rest of the forecast period. Skelly && .PUB WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until noon MDT Wednesday for COZ058>061- 063-065>068. Winter Storm Warning until noon MDT Wednesday for COZ072-073-076- 078>082-084. Winter Storm Warning until 6 PM MDT Wednesday for COZ074-075. Winter Storm Warning from midnight tonight to 6 PM MDT Wednesday for COZ087-088. Winter Weather Advisory from midnight tonight to noon MDT Wednesday for COZ094. && $$ UPDATE...PETERSEN SHORT TERM...KT LONG TERM...KT AVIATION...SKELLY
Area Forecast Discussion
National Weather Service Raleigh NC
915 PM EDT Tue Mar 28 2017 .SYNOPSIS... Surface cold front will cross the area this evening. Weak high pressure will follow the front for tonight and Wednesday. Another storm system approach our area Thursday night and Friday, bringing another round of stormy weather. && .NEAR TERM /THROUGH TONIGHT/... As of 915 PM Tuesday... Last bit of convection has exited the SE zones over the past hour, in concert with the exiting upper level trough and attendant deeper moisture moving off the Mid-Atlantic coast. At the surface, lead sfc front/trough has pushed east into the area, most distinguishable by the drier/lower sfc dewpoints that have advected into the NC Piedmont and Sandhills. However, it will be with a secondary NELY surge behind a back-door cold front late tonight between 06 to 12z that will bring the noticeably cooler air into the area. NAM fcst soundings and HRRR depict a layer of low-level moisture stratus advect into the area within the low-level NELY flow. Will increase cloud cover the north and northeast. Lows tonight in the lower to mid 50s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... As of 335 PM Tuesday... Wed-Wed Night: With shortwave ridging aloft, expect mostly sunny to partly cloudy skies and above normal temps in the mid/upper 70s Wed afternoon. Subsidence in the wake of an upper level low moving offshore New England Wed evening will result in pressure rises along the eastern seaboard as an inverted sfc ridge extends southward through the Mid-Atlantic into the Carolinas, the leading edge of which will be marked by a backdoor cold frontal passage /wind shift to the NE at ~15 mph/. Lows Wed night will be determined by the precise timing of fropa. Based on the latest guidance, expect temps ranging from the mid 40s NE Coastal Plain to lower 50s in the SW Piedmont. Thu: In the wake of the backdoor cold front, NE low-level flow will veer to the E/ESE during the day, allowing temperatures to recover into the mid/upper 60s to lower 70s across the Sandhills and SE Coastal Plain Thu afternoon. A cold air damming wedge is expected to develop across portions of the Foothills and N/NW Piedmont as warm advection (via SW H85 flow) strengthens atop the shallow cooler airmass in place near the surface. As a result, broken/overcast cloud cover should largely offset diurnal heating across portions of the N/NW Piedmont where highs may struggle to exceed the mid 50s, esp in Forsyth county. -Vincent && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY NIGHT/... As of 335 PM Tuesday... Thu night: Expect an increasing potential for elevated showers across the western half of the state (west of Highway 1, primarily the NW Piedmont) between midnight and sunrise Fri as an upper level low progresses across the central MS river valley into the western TN valley and low-level warm advection strengthens downstream over the Carolinas. Expect lows Fri morning ranging from the mid/upper 40s (N/NE) to lower 50s, warmest Sandhills and SW Piedmont. Fri-Fri Night: Uncertainty in the evolution of the approaching upper level low and attendant sfc cyclone has decreased over the past 24 hours now that the ECMWF is in much closer agreement to the GFS, however, confidence in temperatures, precip amounts and convective intensity remains relatively low due to the expected presence of a CAD wedge and potential for upstream convection /latent heat release/ to alter low-level height/wind fields over the Southeast/Carolinas. Although precip amounts remain uncertain, precipitation chances Friday/Friday night remain solid. As such, have increased pops to categorical (~80%). A potential for organized severe thunderstorms will exist Friday afternoon and evening given the synoptic pattern progged by the GFS/ECMWF, however, the overall extent/character of the threat remains difficult to ascertain at this range, as do forecast temperatures for Fri/Fri night. With the most recent guidance in mind, will indicate highs ranging from the lower 60s in the Triad to the lower/mid 70s in the Sandhills/SE Coastal Plain. A clearing trend from SW-NE is expected in the wake of a cold frontal passage after midnight. Lows Sat morning will depend primarily upon fropa timing, ranging from the lower 50s N/NW to mid 50s S/SE. Sat-Sun night: A potential for isold showers may surface Saturday afternoon east of Hwy 1 if DPVA attendant shortwave energy digging SE along the western periphery of the departing upper level low occurs in vicinity of peak heating. Otherwise, expect dry conditions and a warming trend over the weekend as a shortwave ridge builds east across the Mid-Atlantic and Carolinas. Expect highs in the lower/mid 70s Sat and mid 70s Sunday as a shortwave ridge aloft tracks across the region from the west. Mon-Tue Night: Expect increasing cloud cover during the day Monday and a chance for convection by Tue as the next upper level low /attendant sfc cyclone/ approach from the west. -Vincent && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... As of 815 PM Tuesday... 24 Hour TAF Period: The initial surface cold front has pushed to the south of central NC this evening, along with any convection and sub- VFR conditions. VFR conditions are expected to continue this evening into early Wednesday morning as surface high pressure builds/extends into the area. However, a reinforcing back-door cold front is expected sink southward into central NC close to daybreak Wednesday. This will usher in the potential for some IFR/MVFR cigs from around daybreak through around noon (before lifting and/or scattering). KRWI stands the best chance of seeing any sub-VFR cigs as moisture in northeasterly low level flow is expected to surge into the northeast/eastern portions of central NC early Wednesday morning. Otherwise, generally light northwesterly winds tonight will become north to northeasterly on Wednesday generally in the 7 to 12 mph range, with possibly a few gusts into the mid teens. Outlook: With surface high pressure building/extending into the area Wednesday night into Thursday in advance of yet another approaching area of low pressure, we may see the development of some sub-VFR cigs early Thursday morning, possibly continuing into Thursday as a CAD wedge develops. A low pressure system will cross the area on Friday through Friday night with the potential for showers and thunderstorms. High pressure with VFR conditions should generally return for the weekend. && .RAH WATCHES/WARNINGS/ADVISORIES... None. && $$ SYNOPSIS...Badgett NEAR TERM...CBL SHORT TERM...Vincent LONG TERM...Vincent AVIATION...BSD/Badgett
Area Forecast Discussion
National Weather Service Blacksburg VA
954 PM EDT Tue Mar 28 2017 .SYNOPSIS... A cold front will slide east across the region early this evening before exiting offshore overnight. High pressure then works in from the north later tonight into Thursday behind the front. Another storm system moves in from the southwest with showers and storms by the end of the week. && .NEAR TERM /THROUGH WEDNESDAY/... As of 945 PM EDT Tuesday... Analysis of the latest HRRR and RAP13 guidance, and trends on regional radars, prompted an extension of isolated showers across parts of western Greenbrier County and Summers County West Virginia by a couple of hours overnight. Still expect a quick conclusion of the precipitation after midnight or 100 AM EDT. Adjusted cloud cover accordingly to account for this increased duration of isolated showers. Also, adjusted hourly temperatures and dew points through the next few hours to account for the latest observations, and expected trends into the early morning hours of Wednesday. No changes were made to the expected low temperatures of the night. No other notable changes were made at this time. As of 755 PM EDT Tuesday... Cold front was just east of the Blue Ridge this evening. Radar showed spotty light showers over the mountains. Have trimmed back probability of precipitation to account for current radar trends. Brief period of upslope clouds/spotty showers mainly northwest sections through early tonight. Upper heights begin to build in the wake of the front overnight with surface high pressure slowly starting to nose in from the north by morning. Thus expecting some clearing espcly Blue Ridge east overnight with more filling in of low clouds mountains later tonight. Expect this along with only weak cool advection to keep lows mostly in the 45-50 range west to low/mid 50s east with some patchy dense fog around espcly valleys and out east where heavier rain has occurred. High to the north will slowly evolve into more of a wedge formation east of the mountains later Wednesday as it builds well to the north. Expect weak sinking motion along with dry air aloft and weak northwest flow to initially allow more sun to develop during the morning before trajectories become a bit more northeast during the afternoon. This may set up a weak convergence zone just east of the mountains where clouds may fill in with heating during the afternoon so boosting clouds a bit. Cant totally rule out a sprinkle or light shower as well but too iffy to include much mention at this point. Otherwise temps dependent upon the amount of insolation before clouds reform so stayed on the low end of Mos which gives 60s mountains to lower 70s southeast. && .SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY NIGHT/... As of 300 PM EDT Tuesday... Surface high pressure over southeastern Canada will wedge south down the east coast Wednesday night. This wedge is relatively shallow, roughly 2kft feet thick, and will remain mainly along and east of the Blue Ridge into Friday morning. This wedge may bleed just west of the Blue Ridge, into the New River Valley and Alleghany Highlands Wednesday night but will likely erode during the day Thursday. Stratus clouds will accompany this wedge and as the flow becomes southeasterly Thursday morning, light rain/drizzle/fog is possible across eastern slopes of the North Carolina High Country and Grayson Highlands. Southeasterly flow is expected along the south-central Virginia Blue Ridge going into the afternoon and evening to spread light precipitation northward. A once strong low pressure system coming out of the Rockies early this week will track slowly eastward over the Midwest. A weak short wave ejected out ahead of this low will increase rainfall rates across the mountains Thursday evening. This wave will likely erode any wedge environment over the mountains. Rain moving east of the Blue Ridge and over the foothills Thursday night may enhance the wedge some. However, rain will be relative warm to keep enhancements minor. The upper level low will open as it tracks over the Ohio-Tenn Valleys Thursday night. A stronger ejected short wave is expected to track from the southern Appalachians and along the Blue Ridge Friday morning. This wave also appears to track along the western wedge boundary. High rainfall rates and mixing will erode what is left of the wedge through the day Friday. The upper level trough swings over the region Friday afternoon and evening pushing heaviest precipitation east. Some scattered mountain showers are expected with the passing of the trough/cool pool with all rain ending by midnight. Overnight lows Wednesday night will fall into the mid to upper 40s. With a wedge in play and light rain forecasted, temperatures Thursday will only warm into the lower 50s. Areas outside of the wedge, such as Bluefield and Richlands, could see temperatures in the lower to mid 60s. Winds remain southeasterly and the atmosphere saturated. Temperatures may fall some during the evening then rise through the early morning hours as the wedge erodes. With the removal of the wedge Friday and despite copious amounts of rain falling, temperatures should manage to recover into the low to mid 60s by the end of the day. && .LONG TERM /SATURDAY THROUGH TUESDAY/... As of 300 PM EDT Tuesday... Surface high pressure builds over the region Saturday, however drier air does not enter the area until Saturday night. Lingering theta-E ridge will likely result in a good amount of fair weather cumulus clouds over the area, becoming clear in the evening. Conditions remain dry into Monday morning, then we wait on the next system tracking across Texas to the Tennessee Valley Tuesday. Precipitation pattern may be similar to Thursday-Friday`s event with light rain over a weak wedge followed by short waves from an upper level low/trough to our west. Temperatures Saturday will be near normal with above normal temperatures Sunday. Temperatures cool down Monday with rain falling into a wedge. Tuesday will be wet with slightly above normal temperatures as wedge erodes. && .AVIATION /02Z WEDNESDAY THROUGH SUNDAY/... As of 755 PM EDT Tuesday... Upper low had moved off the southeast Virginia coast with the surface cold front just east of the Appalachians at 23Z/7PM. Models showed mid and upper levels drying out overnight with low level moisture in the mountains. With northwest upslope winds overnight, expecting MVFR stratus at KBLF and KLWB, lowering to IFR overnight. Models bring MVFR clouds into KDAN and KLYH after 06Z/2AM on the west side of the retreating low. In between these low clouds and the upslope cloud cover, anticipate enough clearing for fog formation, especially in the valleys. Confidence is low as to the areal extent of the fog and how low the visibility will get. KBCB has the potential for LIFR fog by Wednesday morning. High pressure slowly builds in from the north on Wednesday with a low level wedge of cooler air developing east of the mountains. Should see some drying under the increasing subsidence but also some uncertainty with the degree of residual cloud cover given heating and flow turning light north . This suggests that KBLF and KLWB will remain MVFR for much of the day. Low clouds in the piedmont, on the west side of the low will lift to VFR and eventually erode during the afternoon. Extended Aviation Discussion... High pressure moves offshore Wednesday night into Thursday with the Mid Atlantic region remaining in the wedge. The next storm system moves in the Mississippi Valley Thursday night into Friday. A threat for IFR and possibly MVFR ceilings and visibilities appears likely Wed night into Thursday with widespread stratus, light rain and drizzle. precip. The highest probability of rain will be on Friday along with sub-VFR cigs/vsbys with the showers. Once the low passes, northwest flow sub-VFR ceilings will remain into Saturday across the mountains with gusty northwest winds possible. && .RNK WATCHES/WARNINGS/ADVISORIES... VA...None. NC...None. WV...None. && $$ SYNOPSIS...JH NEAR TERM...AMS/DS/JH SHORT TERM...RCS LONG TERM...RCS AVIATION...AMS/JH