Arts Fest and Thunderstorms

Arts Fest + Severe Thunderstorms Warning = ....

We'll find out soon...quite dark to the SW of Walker building with a line that is beginning to bow...tie down those tents with all your art stuff inside! Two tornadoes have also been reported in PA today (one near Williamsport and the other in northeastern Pennsylvania.)

June 10, 2009 Spotting

After not chasing on June 9, an impromptu spotting yesterday afternoon (this was a year to the date I found the spot). Convection was south of of SCE most of the day, but around 5 I noticed an interested cell pulsing just SW of SCE. So I headed out to my spot. Just some moderate rain...nothing much. Although, the most exciting thing was probably the formation of fog after this rain passed through to my north (air was cooled to dewpoint because of rain/evaporative cooling) A few pics...

Cyclist trying to beat the storm

What is that just below the horizon? Is it fog?

Yes, it is fog. Pretty sweet.

Severe T'Storm Watch east of SCE

A severe thunderstorm watch has been issued east of SCE, in the better CAPE environment. The cold front has passed here, it appears as dewpoint and temperature have fallen a few degrees

6/9 Discussion

A few storms have fired in SW PA south of Pittsburgh south and along the I76 corridor. SPC 15z mesoanalysis has a solid 2000J/kg of CAPE along and east of a N-S line intersecting State College. (SCE) A band of 2500J/kg are also located just east of here. Shear is fairly unidirectional, but 500mb shear is around 30kts.

More storms are forming south of of SCE, but they are fairly widely-scattered.

Storm Spotting 6/9

A mesoscale discussion was issued about 20 minutes ago that central Pennsylvania will be upgraded to a slight risk in about 20 minutes. While I don't want to chase anything after the mid-May utter failure, I may go out to my favorite spot to take some pictures and see what moves through. 12z WRF wasn't impressive, but I haven't looked at the PSU WRF, which is usually more exciting (although not necessarily more realistic)

Cold front is currently in NW PA. It feels quite warm even though it is just 78 at noon. The dewpoints are in the upper 60s, which is equivalent to where the VORTEX2 folks are at today (currently watching to the live stream). However, are shear is not favorable for tornadoes.

This is somewhat similar to yesterday as it was warm in the morning and then thunderstorms developing in the late afternoon. Saw a few good lightning strikes northwest of campus around 5PM.

Sunday's Cold Frontal Convection

Some pictures from yesterday afternoon's cold front convection as it pushed southward through Pennsylvania. Here's a radar loop for those meteorologically-inclined individuals...or anyone. :)

More of a post when I have time.

5/16: Afternoon Update 2

Had a gusty shower go through around 2:15 with peak winds of 35 mph on the Walker roof. This cell was weakening as it moved through via radar. Have had other activity around State College, but nothing that has come over the building again. Currently, looking NW from Walker, another little shower has formed just west of I99. This has been the trend all afternoon, with a shower or thunderstorm forming in this same location, then moving northeast and dissipating. To the west, a cluster of showers and perhaps a thunderstorms are moving toward SCE. That will likely get here before I get out the door.

Previous Post:
A tornado warning has been issued for Tioga County (north central PA) based on doppler radar until 2:15EDT.

Activity closer to State College has started to congeal into a line, but the State College Bubble Effect prevented anything from reaching town.

5/16 chase update

Severe thunderstorm watch was issued a short time ago for central New York and much of Pennsylvania, including State College (SCE). A mesoscale discussion was issued around noon. Storms currently forming just west of SCE along the ridges. This is similar to 4km PSU WRF if I recall from memory correctly.

I got to close out this newspaper edition and write a Boston forecast. I'll write more if time allows...looking good right now though...

5/16 Chase Update

As I was expecting, there are plenty of clouds over the Middle Atlantic States. We'll really need some break of sunshine in order to boost the CAPE values and have some decent storms by PA standards. 0z cloud product guidance has the WRF most aggressive with the clouds (which is typically when compared to the GFS, largely because of the grid spacing) with low clouds early today and then mid-clouds the remainder of the day. The GFS would offer more sunshine through mid-afternoon, but considering it doesn't have any clouds this morning (and we are currently cloudy), not sure how much to buy it.

6z WRF looks disorganized with the precipitation early in the day before it becomes more well-defined around the cold front this afternoon. The 0z Penn State 4km WRF simulated reflectivity shows some prefrontal convection forming along the ridges west of State College around 18z. Those cells move east of State College by 21z and the front becomes the focus for convection, with frontal convection reaching State College around 0z and departing the area likely by 3z. While I would like to throw all my chips into this model, I know that would just be the illusion of predictability (as Rich Grumm, NWS CTP says).

As I stated in last night's post, chasing will ultimately be determined by what the current observations are later this afternoon. SPC still has a good chunk of PA in the slight risk, with 5% tornado probability, 15% hail (south of State College) and 15% damaging winds.

Work, then chase?

Briefly, I have tentatively plans to chase tomorrow afternoon. Tentative enough that I got my gear out and charging. :)

While I'm not anticipating anything widespread, a slight risk is enough to get me moving out of town. However, I work until about 4:30, so that will keep me anchored until then. Ultimately, it will come down to what the current weather situation is when I leave the office. I think the front will be close to the State College area between 21-00z, which would give me plenty of time to get into position south of town in the valley. While dewpoints will be in the low 60s, if we can get some sunshine in the afternoon, that will help boost CAPE values to around 1000 J/kg. With the front swinging through, that will provide the lift so the storms can tap into the energy, but hopefully not too soon.

We'll see what happens soon.