Know what to expect! = Climo. PSU … June 22 data RH RL

Penn State Weather Camps Basic Weather Forecasting Guidelines Sat I Sat I – Sat II – Sat III - NWS - NHC - Radar - RadarSat II Sat III NWSNHCRadar sfc. map 1 sfc. map 1 - sfc. map 2 – sfc map 3sfc. map 2sfc map 3

? ? ? X X X Vorticity maximums (vort max) -Shortwaves -Upper-level troughs -Jet stream disturbances H Height over State College?

582 X 570 HT MON = 585 dm HT WED = 572 dm Height Falls of ? Height over State College?

SURFACE PRESSURE ? ? ? ? ?

Warm Sector vs. Cool Sector

L L 576

DAY 1 OUTLOOK - MONDAY

A HIGH MOISTURE CONTENT AIR MASS /PRECIPITABLE WATER VALUES OF INCHES/ WILL REMAIN IN PLACE FROM THE EASTERN PARTS OF THE SOUTHERN PLAINS TO GULF COAST STATES AND TN VALLEY...AND EXPAND EAST/NORTHEAST INTO THE CENTRAL/SOUTHERN APPALACHIANS AHEAD OF THE NY/PA TO KY/TN COLD FRONT. DESPITE WEAK MIDLEVEL LAPSE RATES...THIS MOISTURE COMBINED WITH SURFACE HEATING/STEEPENING LOW-LEVEL LAPSE RATES SHOULD RESULT IN MODERATE DESTABILIZATION. FORCING FOR ASCENT ATTENDANT TO WEAK HEIGHT FALLS ON THE SOUTHERN PERIPHERY OF THE AMPLIFYING GREAT LAKES TROUGH...CONVERGENCE ALONG THE COLD FRONT...AND OROGRAPHIC ASCENT WILL LIKELY PROVE FAVORABLE FOR STORM DEVELOPMENT THROUGH THIS AFTERNOON. STORM ORGANIZATION WILL BE MINIMAL DUE TO WEAK BULK SHEAR...THOUGH STEEP LOW-LEVEL LAPSE RATES AND WATER LOADING OF DOWNDRAFTS SHOULD ENHANCE THE POTENTIAL FOR SOME STORMS TO PRODUCE LOCALLY STRONG WIND GUSTS. THIS MARGINALSEVERE-WEATHER RISK SHOULD BE DIURNAL AND DIMINISH THIS EVENING.

DAY 2 OUTLOOK - TUESDAY

...CNTRL NC/MID-ATLANTIC/NORTHEAST... AN UPPER-LEVEL TROUGH IS FORECAST TO MOVE ESEWD ACROSS THE LOWER GREAT LAKES AND UPPER OH VALLEY ON TUESDAY. AT THE SFC...A COLD FRONT IS FORECAST TO MOVE EWD ACROSS THE CNTRL APPALACHIAN MTNS WITH A NARROW CORRIDOR OF INSTABILITY DEVELOPING BY AFTERNOON AHEAD OF THE FRONT. AS SFC HEATING TAKES PLACE AND LOW-LEVEL CONVERGENCE INCREASES...THUNDERSTORMS SHOULD INITIATE ALONG AND JUST AHEAD OF THE FRONT DURING THE AFTERNOON FROM ERN NY SSWWD INTO THE MID-ATLANTIC AND CNTRL NC. FORECAST SOUNDINGS ALONG THIS CORRIDOR FOR 21Z/TUE SHOW SFC DEWPOINTS IN THE MID 60S F WITH STEEP LOW-LEVEL LAPSE RATES AND 25 TO 30 KT OF 0-6 KM SHEAR. THIS SHOULD BE ENOUGH FOR MARGINALLY SEVERE WIND GUSTS AND HAIL WITH THE STRONGER UPDRAFTS.

Basic Forecast Guidelines Climatology Forecast = averages for today Persistence Forecast = yesterday’s valuesyesterday’s values Modified Persistence = Persistence + Any changes

Penn State Weather Camps Basic Weather Forecasting Guidelines Sat I Sat I – Sat II – Sat III - NWS - NHC - Radar - RadarSat II Sat III NWSNHCRadar sfc. map 1 sfc. map 1 - sfc. map 2 – sfc map 3sfc. map 2sfc map 3

NHC TROPICAL DEPRESSION Winds of knots (38 mph or less) TROPICAL STORM Winds of knots (39 to 73 mph) HURRICANE Category 1: Winds of knots (74-95 mph) Very dangerous winds will produce some damage Category 2: Winds of knots ( mph) Extremely dangerous winds will cause extensive damage Category 3: Winds of knots ( mph) Devastating damage will occur Category 4: Winds of 114 to 135 knots ( mph) Catastrophic damage will occur Category 5: Winds above 135 knots (157 mph) Catastrophic damage will occur ATL HURRICANESWX UNDERGROUND ATL HURRICANESWX UNDERGROUND

Center of High and Low pressure Isobars

Penn State Weather Camps Basic Weather Forecasting Guidelines Sat I Sat I - NWS - NHC - Radar - RadarNWSNHCRadar sfc. map 1 sfc. map 1 - sfc. map 2 – sfc map 3sfc. map 2sfc map 3

Basic Forecast Guidelines What causes temperature to change? ◦Cloud cover: ◦Precipitation:  When it rains T’s ….. ◦Wind:  Direction - Speed

Basic Forecast Guidelines What causes rain? ◦Need clouds!  Will any ole cloud do? ◦Moisture  Bodies of water – Moisture content of air

Basic Forecast Guidelines Extrapolation= Look upstream to see what’s coming! ◦Sat IR - Sat II - Sat VIS - Radar - sfc. map 1 - sfc. map 2 – sfc map 3Sat IR Sat II Sat VIS Radarsfc. map 1 sfc. map 2sfc map 3

Basic Forecast Guidelines The “Models” ◦What are they? The “Models” ◦Lower Res. (GFS)Lower Res. (GFS) ◦Higher Res. (GFS)Higher Res. (GFS) ◦Higher Res. (NAM)Higher Res. (NAM) ◦Higher Res. (HRRR)Higher Res. (HRRR) ◦MOS - Statistical guidanceMOS - Statistical guidance

Your competition !!! ◦The National Weather ServiceThe National Weather Service ◦The Weather ChannelThe Weather Channel ◦AccuweatherAccuweather ◦The guy or gal to your left and right