A strong coastal storm developed over the eastern Gulf of Mexico, crossed the Florida peninsula, and pushed northward up the East Coast from December 17 through December 19, 2023. This system produced 2-4 of rainfall across the eastern half of Pennsylvania, which led to localized flooding.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS CTP wrote it up.
A strong coastal storm developed over the eastern Gulf of Mexico, crossed the Florida peninsula, and pushed northward up the East Coast from December 17 through December 19, 2023. This system produced 2-4 of rainfall across the eastern half of Pennsylvania, which led to localized flooding. As colder air rushed in behind the system, 6 to 8 inches of snow fell across portions of Pennsylvania's Laurel Highlands.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS State College, PA wrote its last area forecast discussion before the first event at Dec 18, 12:30 AM EST, 2 hours 52 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 1230 AM EST Mon Dec 18 2023 .SYNOPSIS... A strong coastal storm will move north along the Carolina coast overnight and bring a widespread soaking to heavy rainfall across all of Central and Eastern Pennsylvania into Monday morning. The soaking rain will be followed by strong blustery northwest winds and accumulating snowfall/heavy snow showers Monday into Tuesday. In the wake of the storm, expect much improved weather conditions by Wednesday with moderating temperatures into late week. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... Moderate to locally heavy rainfall rates have reached into the Lower Susq and parts of the SC Mountains this evening, with QPE exceeding 1.25" thus far in parts of these areas. Rainfall totals thus far through 1030 PM range from 1.25"+ at KMDT and 1.00+" at KTHV to .67"+ from the SC Mountains northward to the Ridge and Valley region. Regional radar mosaic indicates heaviest rain band setting back up from northern Adams County through Dauphin and Schuylkill County at this hour. Inst rafl rates do exceed 1.5 to 2" but with no training anywhere. FFMP indicates heaviest hourly rates of 0.8" to 1"+ within the aforementioned area. Overall model trend of the past 24 hours has continued into this evening with hi res runs of the HRRR and NAM12 simulating the heaviest rainfall of 2.5-3"+ farther east, now straddling the eastern borders of Schuylkill and Lancaster Counties. Correspondingly we've nudged our rainfall totals in that direction with generall half to three quarter inch reductions in storm totals into the central mountains, but still a very solid 2"+ across the eastern third of central PA. Best chances to see 3" or more remains eastern Lancaster and Schuylkill County at this time. Heaviest rainfall of the storm over the Lower Susq River Valley will be from now through 06-07z. Sfc low northeast of Charleston SC this evening will deepen by 7-8 mb by the time it reaches the Delmarva region during the predawn hours Monday, then reach NYC by midday Monday. Tonight's rainfall is only the first part of a multi- faceted storm system that will eventually bring a "triple threat" of heavy rain, wind, and snow to central PA over the next 24 to 48 hours. Flood Watch remains in effect for the eastern half of central PA, where 2" or more would at least cause minor flooding of poor drainage areas and significant rises on flashier creeks. Lower QPF may eventually keep they usual suspects (Swatara, Harper's Tavern, etc) just under flood stage (and also just below the 6 hourly Flash Flood Guidance values of 2 - 2.5 inches). We'll continue to watch upstream rainfall estimates and gage readings into the overnight. Locally higher amounts over 3" remain possible in the favored higher terrain of east-central PA where upslope lift will be enhanced/maximized with southeast exposure. However, with a band of deeper convection possible near the I-95 corridor some of the deeper moisture could be robbed from our eastern CWA. Period of heaviest rainfall wraps up by 12z Monday from south to north. As for gusty winds, although an anomalous low-level jet will overrun eastern PA later this afternoon and evening, model sounding profiles also show the existence of an inversion above the boundary layer, which should prevent the strongest winds from mixing to the surface, save for perhaps the highest elevations. Colder air wrapping into the backside of the storm behind a blustery NW flow could begin to change rain to snow over the Laurel ridges by the end of the period as we transition into the next phase of the storm. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... Good, in depth collaboration with surrounding WFOs to maintain Winter Storm Watch for Warren County for a combination of Synoptic and LES (and a Winter Weather Advisory for the Wrn Mtns), and a Winter Storm Warning remains in effect for Somerset County where the track of the deepening nrn stream trough and long fetch off the upstream Glakes and orographic lift will combine to bring a favorable setup for significant snow. Potential for heavy lake enhanced and upslope driven snow accums has increased since this morning (NBM 55-60% percent chance of >=6" along Laurel Mtn west of US219). The strong gusty NW wind could enhance winter/travel impacts with blowing snow and significantly reduced visibility. Model instability appears to be lacking for widespread squalls as the cold air arrives, with robust instability tracking well south of the Mason Dixon line, but some moderate snow bursts are possible by Monday evening as 5H trough axis slices across the region. Peak wind gusts (out of the NW) just below advisory category thresholds (35-45 mph) should develop from later Monday into early Tuesday as cold advection steepens lapse rates and improves downward momentum transfer. Best wind gusts should impact the area Monday evening as the upper trough axis passes the area and boundary layer mixing and channeled flow is maximized. This will continue to highlighted in our HWO and contained in the wording of the WSWs. The wind shift from southeast to northwest amidst saturated soils could support an elevated risk of localized power outages as trees sway and water logged limbs fall in the blustery conditions. Snow showers likely last through Tuesday morning before diminishing as high pressure over the Plains shifts to the east over WV Tuesday night. Temps on Monday likely exhibit a non- diurnal trend with Tuesday being the seasonably coldest day of the week with highs in the upper 20s to upper 30s. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... Continuation of enhanced NW'ly flow in the wake of the sfc low will promote lake-enhanced precipitation through Tuesday morning. Plowable snowfall Monday night into Tuesday over the NW and along the Laurel Highlands remains likely with the NW flow providing enhanced fetch off lake Erie and a continuous upslope flow along the Allegheny mountains. The limiting factor will be the deep layer flow becoming more anticyclonic as this will cut into the residence time for the increased moisture and limit overall snow amounts. If given trends are maintained we'd expect some additional winter headlines to be needed for the Monday night- Tuesday timeframe. High pressure will begin building to the south after Tuesday morning and encourage a similar trend to what we have seen the last couple weeks. A slight warming in temps towards the end of the week and dry conditions expected until the next low pressure system approaches from the west during the weekend. Deterministic guidance does suggest a return of precipitation towards the end of the extended period as a sfc low approaches from the west. Timing and coverage remains uncertain at this time, especially with the last couple runs not being consistent, so we have capped PoPs at Chc/SChc for Friday night with higher chances coming in closer to the Saturday morning timeframe. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... 06Z TAFS sent. Bands of moderate to at times heavy rain will be lifting northward across the area through about 09Z. Winds not real strong at this time and a lot of variation. Expect winds to shift to the northwest and pick up in speed in a few more hours. Earlier discussion below. LIFR to IFR conds across central PA will continue Sunday evening into Monday morning with high (70-80%) confidence as the surge of Atlantic moisture continues progressing northward. Conds will deteriorate further within the axis of heaviest rainfall, with LIFR thresholds on vsby and cigs likely based on RAP model soundings with saturated profiles at the lowest levels. At this time, have timed out this rainfall to impact MDT/LNS between 03-05Z and IPT/UNV between 04Z-06Z given the progressive movement of this feature. There is some possibility that restrictions come an hour sooner, but have kept closer to guidance which has been fairly consistent run-to-run wrt timing of impacts at these airfields. Further to the west, timing of heaviest rainfall becomes slightly less certain, but moderate (50-60%) confidence on impacts at JST/AOO/BFD in the 05-08Z timeframe with similar thinking on +1hr and restriction onset. IFR/LIFR conds at daybreak expected (90+% confidence) to continue into the day at BFD/JST with snow mixing in late in the TAF period (~17-18Z) and becoming the more dominant precipitation type in the 21-22Z timeframe. For all other terminals, some improvement is possible later on in the TAF period after an initial period of LIFR/IFR conds. Some relatively drier air has potential to curb off precipitation west of the Alleghenies, with MVFR cigs possible closer to the 16Z timeframe. There is moderate (40-50%) confidence on this gradual improvement and have kept some lower clouds in the fcst to outline slightly lower confidence on the lower cloud deck scattering out until there is more model consistency. NW'ly winds (at 300-330) will prevail Monday morning with sustained 15-20 kts (lower elevations) to 20-25 kts (higher elevations) and gusts pushing towards 35 kts at the highest elevations of southern PA and along the Allegheny Front. Winds will continue into the end of the TAF period and likely beyond with high (80-90%) confidence. Outlook... Tue...Snow persists at BFD/JST, w/ variable conds (VFR much of the time, occasional restrictions in flurries/SNSH) elsewhere. Wed and Thu...Predominantly VFR. Fri...Rain moves in from the west late, restrictions possible. && .CLIMATE... It has been 325 days since the last measurable snowfall (>=0.1") at Harrisburg. This currently ranks as the 3rd longest run on record. There is a low probability for measurable snow Monday night into Tuesday; otherwise the longest run looks very much in jeopardy based on the forecast into next weekend. 1. 330 days ending 12/13/2020 2. 328 days ending 01/21/2007 3. 325 days ending 12/16/2023 && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Storm Watch from this afternoon through Tuesday morning for PAZ004. Winter Weather Advisory from 1 PM this afternoon to 10 AM EST Tuesday for PAZ005-010-017-024. Flood Watch through this evening for PAZ028-037-041-042-046- 049>053-056>059-063>066. Winter Storm Warning from 1 PM this afternoon to 10 AM EST Tuesday for PAZ033. && SYNOPSIS...Lambert/DeVoir/Steinbugl NEAR TERM...Lambert/DeVoir/Steinbugl SHORT TERM...Lambert/DeVoir/Steinbugl LONG TERM...DeVoir/NPB/Bowen AVIATION...Martin/NPB CLIMATE...Dangelo/Steinbugl
Hazardous Weather Outlook National Weather Service State College PA 1047 PM EST Sun Dec 17 2023 PAZ004-190400- Warren- 1047 PM EST Sun Dec 17 2023 ...WINTER STORM WATCH IN EFFECT FROM MONDAY AFTERNOON THROUGH TUESDAY MORNING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. A period of moderate to heavy rain late tonight could cause some localized minor flooding especially in low lying and poor drainage areas. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Winter Storm Watch. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ005-010-017-024-190400- McKean-Elk-Clearfield-Cambria- 1047 PM EST Sun Dec 17 2023 ...WINTER WEATHER ADVISORY IN EFFECT FROM 1 PM MONDAY TO 10 AM EST TUESDAY... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. A period of moderate to heavy rain late tonight could cause some localized minor flooding especially in low lying and poor drainage areas. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Winter Weather Advisory. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ033-190400- Somerset- 1047 PM EST Sun Dec 17 2023 ...WINTER STORM WARNING IN EFFECT FROM 1 PM MONDAY TO 10 AM EST TUESDAY... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. A period of moderate to heavy rain late tonight could cause some localized minor flooding especially in low lying and poor drainage areas. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Winter Storm Warning. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ006-011-012-018-019-025>027-034>036-045-190400- Potter-Cameron-Northern Clinton-Northern Centre-Southern Centre- Blair-Huntingdon-Mifflin-Bedford-Fulton-Franklin-Southern Clinton- 1047 PM EST Sun Dec 17 2023 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. A period of heavy rain late tonight could cause some isolated minor flooding especially in low lying and poor drainage areas. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Windy conditions with peak gusts from the northwest at 40 to 45 mph could damage outdoor items and result in difficult driving for high- profile vehicles on Monday. Rain will change to snow Monday night with a light accumulation possible into Tuesday. Isolated heavy snow showers and squalls are also possible. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ028-037-041-042-046-049>053-056-057-059-063>066-190400- Juniata-Tioga-Northern Lycoming-Sullivan-Southern Lycoming-Union- Snyder-Montour-Northumberland-Columbia-Perry-Dauphin-Lebanon- Cumberland-Adams-York-Lancaster- 1047 PM EST Sun Dec 17 2023 ...FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flood Watch. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flood Watch. Rain will change to snow Monday night into Tuesday with a light accumulation possible. Windy conditions with peak gusts from the northwest at 40 to 45 mph could damage outdoor items and result in difficult driving for high- profile vehicles on Monday. A few power outages are possible with downed trees or limbs given preceding heavy rainfall and saturated soil. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ058-190400- Schuylkill- 1047 PM EST Sun Dec 17 2023 ...FLOOD WATCH REMAINS IN EFFECT THROUGH MONDAY EVENING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flood Watch. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Flood Watch. Rain will change to snow Monday night into Tuesday with a light accumulation possible. Windy conditions with peak gusts from the northwest at 40 to 45 mph could damage outdoor items and result in difficult driving for high- profile vehicles on Monday. A few power outages are possible with downed trees or limbs given preceding heavy rainfall and saturated soil. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather.
The national radar mosaic for the moment the first event began.
4 flood, 1 heavy snow. Local standard time, as filed.
Heavy rainfall and flooding led to several water rescues in Strasburg Township during the early morning hours of December 18, 2023. One location impacted was near the intersection of Lime Valley Road and Brenneman Road.
Heavy rain caused flooded roadways and pushed creeks out of their banks in Dushore.
Heavy rainfall (3 to 4 inches) produced flooded roadways in portions of Lebanon County. Specifically, Greble Road near the village of Greble was closed due to flooding.
Heavy rainfall led to flooding along Cabin Drive near Ephrata during the early morning hours of December 18, 2023. A direct fatality was reported when a 73-year old male drove into the flood waters and drowned during the pre-dawn hours.
A winter storm produced 6 to 8 inches of snow across the higher elevations of Somerset County from the afternoon of December 18 through the morning hours of December 19, 2023.
As the offices recorded each death: direct deaths were caused by the weather itself, indirect ones by something it set in motion.
| Event | Date | Age | Sex | Where | Kind |
|---|---|---|---|---|---|
| Flood, Lancaster | 2023-12-18 | 73 | Male | Vehicle/Towed Trailer | Direct |
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2023Every state in 2023This day in weather historyWarnings in Pennsylvania, December 2023
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1145396, 1145393, 1145394, 1144868, 1147794.