the misadventures of weather boy: Shuttle landing forecasts

Saturday, July 15, 2006

Shuttle landing forecasts

As I noted earlier, I would lend some interpretation to landing forecast when the SMG included Monday in its landing forecast. This morning, we get the first look at the landing forecast for Monday and Tuesday. NASA has budged its projected landing time in Florida slightly to 9:14am EDT (1314Z). Based on the inclinations of the earlier local forecasts, it is unlikely that the shuttle is touching down in Florida this mission either.

Among other concerns, the shuttle cannot land in a ceiling under 8000 feet, in precipitation, or windy conditions.

"Perma"link to this forecast. Use this link for the latest forecast.
First try:

SHUTTLE LANDING FACILITY...KENNEDY SPACE CENTER FL
 FIRST OPPORTUNITY
 KSC  FEW020 BKN100 BKN250           7              26003P05
      CHC SHRA WI 30

Meaning: < 25% coverage at 2000 feet, 75% coverage at 10000 and 25000 feet (ceiling=10000 feet, okay). Visibility 7 statute miles (good). Winds out of 260 degrees (from the west) at 3 knots (about 4MPH), peaking to 5 knots. The big issue is the last line–chance of showers within 30 nautical miles. The NWS forecast currently lists "scattered afternoon showers", and the chance part seems to indicate a POP of ≤ 20%.

 SECOND OPPORTUNITY
 KSC  SCT025 BKN100 BKN250           7              22005P07
      SHRA WI 30

Meaning: 3/8-4/8 coverage at 2500 feet; ceiling at 10000 feet (good). Visibility 7 miles; winds from southwest at 5-7 knots. Rain showers within 30 nautical miles.

 EDWARDS AIR FORCE BASE CA
 EDW  FEW150 SCT250                  7              20005P08
      WND 20010P15 AFT 17Z

Meaning: <25% coverage at 15000 feet; <50% coverage at 25000 feet (no ceiling). Visibility 7 miles; winds south-southwest at 5-8 knots; winds change to 10-15 knots after 17Z (1pm EDT, 10am PDT).

 NORTHRUP STRIP...WHITE SANDS SPACE HARBOR NM
 NOR  FEW060 SCT120 BKN250           7              16004P07

Meaning: <25% coverage at 6000 feet, <50% coverage 12000 feet, ceiling at 25000 feet. Visibility 7 miles; winds from south-southeast at 4-7 knots.
Edwards should be okay to land at Monday, but Florida is out of the question.

Tuesday: Florida: Ceiling 1000 feet, visibility good, winds from south at 3-5 knots. Change of rain showers within 30 nautical miles.
California: Ceiling 12000 feet, visibility good, winds from south at 5-8 knots.
New Mexico: Ceiling 25000 feet, visibility good, winds from southeast at 5-8 knots.
Looking further forward on the SMG Weather Forecast Sheet, on page 2 there is still a chance of showers within 30 nautical miles on Wednesday.

Given the nature of forecasts, I suspect that NASA will try for Florida on Monday, and should Florida not work out on Monday, it will probably be an Edwards Air Force Base landing on Tuesday.

The next forecast is issued later this evening around 23Z-00Z.

METAR KRDU 151751Z 31505KT 10SM FEW045 SCT090 BKN150 BKN250 32/22 A3001 RMK SLP157 1033 2025

Labels: meteorology, space